- Copy stable/9 to releng/9.2 as part of the 9.2-RELEASE cycle.

[FreeBSD/releng/9.2.git] / contrib / bind9 / lib / dns / zone.c

/*
 * Copyright (C) 2004-2012  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1999-2003  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id$ */

/*! \file */

#include <config.h>
#include <errno.h>

#include <isc/file.h>
#include <isc/mutex.h>
#include <isc/print.h>
#include <isc/random.h>
#include <isc/ratelimiter.h>
#include <isc/refcount.h>
#include <isc/rwlock.h>
#include <isc/serial.h>
#include <isc/strerror.h>
#include <isc/stats.h>
#include <isc/stdtime.h>
#include <isc/string.h>
#include <isc/taskpool.h>
#include <isc/timer.h>
#include <isc/util.h>

#include <dns/acache.h>
#include <dns/acl.h>
#include <dns/adb.h>
#include <dns/callbacks.h>
#include <dns/db.h>
#include <dns/dbiterator.h>
#include <dns/dnssec.h>
#include <dns/events.h>
#include <dns/journal.h>
#include <dns/keydata.h>
#include <dns/keytable.h>
#include <dns/keyvalues.h>
#include <dns/log.h>
#include <dns/master.h>
#include <dns/masterdump.h>
#include <dns/message.h>
#include <dns/name.h>
#include <dns/nsec.h>
#include <dns/nsec3.h>
#include <dns/peer.h>
#include <dns/private.h>
#include <dns/rbt.h>
#include <dns/rcode.h>
#include <dns/rdataclass.h>
#include <dns/rdatalist.h>
#include <dns/rdataset.h>
#include <dns/rdatasetiter.h>
#include <dns/rdatastruct.h>
#include <dns/rdatatype.h>
#include <dns/request.h>
#include <dns/resolver.h>
#include <dns/result.h>
#include <dns/rriterator.h>
#include <dns/soa.h>
#include <dns/ssu.h>
#include <dns/stats.h>
#include <dns/time.h>
#include <dns/tsig.h>
#include <dns/xfrin.h>
#include <dns/zone.h>

#include <dst/dst.h>

#define ZONE_MAGIC                      ISC_MAGIC('Z', 'O', 'N', 'E')
#define DNS_ZONE_VALID(zone)            ISC_MAGIC_VALID(zone, ZONE_MAGIC)

#define NOTIFY_MAGIC                    ISC_MAGIC('N', 't', 'f', 'y')
#define DNS_NOTIFY_VALID(notify)        ISC_MAGIC_VALID(notify, NOTIFY_MAGIC)

#define STUB_MAGIC                      ISC_MAGIC('S', 't', 'u', 'b')
#define DNS_STUB_VALID(stub)            ISC_MAGIC_VALID(stub, STUB_MAGIC)

#define ZONEMGR_MAGIC                   ISC_MAGIC('Z', 'm', 'g', 'r')
#define DNS_ZONEMGR_VALID(stub)         ISC_MAGIC_VALID(stub, ZONEMGR_MAGIC)

#define LOAD_MAGIC                      ISC_MAGIC('L', 'o', 'a', 'd')
#define DNS_LOAD_VALID(load)            ISC_MAGIC_VALID(load, LOAD_MAGIC)

#define FORWARD_MAGIC                   ISC_MAGIC('F', 'o', 'r', 'w')
#define DNS_FORWARD_VALID(load)         ISC_MAGIC_VALID(load, FORWARD_MAGIC)

#define IO_MAGIC                        ISC_MAGIC('Z', 'm', 'I', 'O')
#define DNS_IO_VALID(load)              ISC_MAGIC_VALID(load, IO_MAGIC)

/*%
 * Ensure 'a' is at least 'min' but not more than 'max'.
 */
#define RANGE(a, min, max) \
                (((a) < (min)) ? (min) : ((a) < (max) ? (a) : (max)))

#define NSEC3REMOVE(x) (((x) & DNS_NSEC3FLAG_REMOVE) != 0)

/*%
 * Key flags
 */
#define REVOKE(x) ((dst_key_flags(x) & DNS_KEYFLAG_REVOKE) != 0)
#define KSK(x) ((dst_key_flags(x) & DNS_KEYFLAG_KSK) != 0)
#define ALG(x) dst_key_alg(x)

/*
 * Default values.
 */
#define DNS_DEFAULT_IDLEIN 3600         /*%< 1 hour */
#define DNS_DEFAULT_IDLEOUT 3600        /*%< 1 hour */
#define MAX_XFER_TIME (2*3600)          /*%< Documented default is 2 hours */
#define RESIGN_DELAY 3600               /*%< 1 hour */

#ifndef DNS_MAX_EXPIRE
#define DNS_MAX_EXPIRE  14515200        /*%< 24 weeks */
#endif

#ifndef DNS_DUMP_DELAY
#define DNS_DUMP_DELAY 900              /*%< 15 minutes */
#endif

typedef struct dns_notify dns_notify_t;
typedef struct dns_stub dns_stub_t;
typedef struct dns_load dns_load_t;
typedef struct dns_forward dns_forward_t;
typedef ISC_LIST(dns_forward_t) dns_forwardlist_t;
typedef struct dns_io dns_io_t;
typedef ISC_LIST(dns_io_t) dns_iolist_t;
typedef struct dns_signing dns_signing_t;
typedef ISC_LIST(dns_signing_t) dns_signinglist_t;
typedef struct dns_nsec3chain dns_nsec3chain_t;
typedef ISC_LIST(dns_nsec3chain_t) dns_nsec3chainlist_t;
typedef struct dns_keyfetch dns_keyfetch_t;

#define DNS_ZONE_CHECKLOCK
#ifdef DNS_ZONE_CHECKLOCK
#define LOCK_ZONE(z) \
         do { LOCK(&(z)->lock); \
              INSIST((z)->locked == ISC_FALSE); \
             (z)->locked = ISC_TRUE; \
                } while (0)
#define UNLOCK_ZONE(z) \
        do { (z)->locked = ISC_FALSE; UNLOCK(&(z)->lock); } while (0)
#define LOCKED_ZONE(z) ((z)->locked)
#else
#define LOCK_ZONE(z) LOCK(&(z)->lock)
#define UNLOCK_ZONE(z) UNLOCK(&(z)->lock)
#define LOCKED_ZONE(z) ISC_TRUE
#endif

#ifdef ISC_RWLOCK_USEATOMIC
#define ZONEDB_INITLOCK(l)      isc_rwlock_init((l), 0, 0)
#define ZONEDB_DESTROYLOCK(l)   isc_rwlock_destroy(l)
#define ZONEDB_LOCK(l, t)       RWLOCK((l), (t))
#define ZONEDB_UNLOCK(l, t)     RWUNLOCK((l), (t))
#else
#define ZONEDB_INITLOCK(l)      isc_mutex_init(l)
#define ZONEDB_DESTROYLOCK(l)   DESTROYLOCK(l)
#define ZONEDB_LOCK(l, t)       LOCK(l)
#define ZONEDB_UNLOCK(l, t)     UNLOCK(l)
#endif

struct dns_zone {
        /* Unlocked */
        unsigned int            magic;
        isc_mutex_t             lock;
#ifdef DNS_ZONE_CHECKLOCK
        isc_boolean_t           locked;
#endif
        isc_mem_t               *mctx;
        isc_refcount_t          erefs;

#ifdef ISC_RWLOCK_USEATOMIC
        isc_rwlock_t            dblock;
#else
        isc_mutex_t             dblock;
#endif
        dns_db_t                *db;            /* Locked by dblock */

        /* Locked */
        dns_zonemgr_t           *zmgr;
        ISC_LINK(dns_zone_t)    link;           /* Used by zmgr. */
        isc_timer_t             *timer;
        unsigned int            irefs;
        dns_name_t              origin;
        char                    *masterfile;
        dns_masterformat_t      masterformat;
        char                    *journal;
        isc_int32_t             journalsize;
        dns_rdataclass_t        rdclass;
        dns_zonetype_t          type;
        unsigned int            flags;
        unsigned int            options;
        unsigned int            db_argc;
        char                    **db_argv;
        isc_time_t              expiretime;
        isc_time_t              refreshtime;
        isc_time_t              dumptime;
        isc_time_t              loadtime;
        isc_time_t              notifytime;
        isc_time_t              resigntime;
        isc_time_t              keywarntime;
        isc_time_t              signingtime;
        isc_time_t              nsec3chaintime;
        isc_time_t              refreshkeytime;
        isc_uint32_t            refreshkeycount;
        isc_uint32_t            refresh;
        isc_uint32_t            retry;
        isc_uint32_t            expire;
        isc_uint32_t            minimum;
        isc_stdtime_t           key_expiry;
        isc_stdtime_t           log_key_expired_timer;
        char                    *keydirectory;

        isc_uint32_t            maxrefresh;
        isc_uint32_t            minrefresh;
        isc_uint32_t            maxretry;
        isc_uint32_t            minretry;

        isc_sockaddr_t          *masters;
        dns_name_t              **masterkeynames;
        isc_boolean_t           *mastersok;
        unsigned int            masterscnt;
        unsigned int            curmaster;
        isc_sockaddr_t          masteraddr;
        dns_notifytype_t        notifytype;
        isc_sockaddr_t          *notify;
        unsigned int            notifycnt;
        isc_sockaddr_t          notifyfrom;
        isc_task_t              *task;
        isc_sockaddr_t          notifysrc4;
        isc_sockaddr_t          notifysrc6;
        isc_sockaddr_t          xfrsource4;
        isc_sockaddr_t          xfrsource6;
        isc_sockaddr_t          altxfrsource4;
        isc_sockaddr_t          altxfrsource6;
        isc_sockaddr_t          sourceaddr;
        dns_xfrin_ctx_t         *xfr;           /* task locked */
        dns_tsigkey_t           *tsigkey;       /* key used for xfr */
        /* Access Control Lists */
        dns_acl_t               *update_acl;
        dns_acl_t               *forward_acl;
        dns_acl_t               *notify_acl;
        dns_acl_t               *query_acl;
        dns_acl_t               *queryon_acl;
        dns_acl_t               *xfr_acl;
        isc_boolean_t           update_disabled;
        isc_boolean_t           zero_no_soa_ttl;
        dns_severity_t          check_names;
        ISC_LIST(dns_notify_t)  notifies;
        dns_request_t           *request;
        dns_loadctx_t           *lctx;
        dns_io_t                *readio;
        dns_dumpctx_t           *dctx;
        dns_io_t                *writeio;
        isc_uint32_t            maxxfrin;
        isc_uint32_t            maxxfrout;
        isc_uint32_t            idlein;
        isc_uint32_t            idleout;
        isc_event_t             ctlevent;
        dns_ssutable_t          *ssutable;
        isc_uint32_t            sigvalidityinterval;
        isc_uint32_t            sigresigninginterval;
        dns_view_t              *view;
        dns_acache_t            *acache;
        dns_checkmxfunc_t       checkmx;
        dns_checksrvfunc_t      checksrv;
        dns_checknsfunc_t       checkns;
        /*%
         * Zones in certain states such as "waiting for zone transfer"
         * or "zone transfer in progress" are kept on per-state linked lists
         * in the zone manager using the 'statelink' field.  The 'statelist'
         * field points at the list the zone is currently on.  It the zone
         * is not on any such list, statelist is NULL.
         */
        ISC_LINK(dns_zone_t)    statelink;
        dns_zonelist_t          *statelist;
        /*%
         * Statistics counters about zone management.
         */
        isc_stats_t             *stats;
        /*%
         * Optional per-zone statistics counters.  Counted outside of this
         * module.
         */
        isc_boolean_t           requeststats_on;
        isc_stats_t             *requeststats;
        isc_uint32_t            notifydelay;
        dns_isselffunc_t        isself;
        void                    *isselfarg;

        char *                  strnamerd;
        char *                  strname;
        char *                  strrdclass;
        char *                  strviewname;

        /*%
         * Serial number for deferred journal compaction.
         */
        isc_uint32_t            compact_serial;
        /*%
         * Keys that are signing the zone for the first time.
         */
        dns_signinglist_t       signing;
        dns_nsec3chainlist_t    nsec3chain;
        /*%
         * Signing / re-signing quantum stopping parameters.
         */
        isc_uint32_t            signatures;
        isc_uint32_t            nodes;
        dns_rdatatype_t         privatetype;

        /*%
         * Autosigning/key-maintenance options
         */
        isc_uint32_t            keyopts;

        /*%
         * True if added by "rndc addzone"
         */
        isc_boolean_t           added;

        /*%
         * whether a rpz radix was needed when last loaded
         */
        isc_boolean_t           rpz_zone;

        /*%
         * Outstanding forwarded UPDATE requests.
         */
        dns_forwardlist_t       forwards;
};

#define DNS_ZONE_FLAG(z,f) (ISC_TF(((z)->flags & (f)) != 0))
#define DNS_ZONE_SETFLAG(z,f) do { \
                INSIST(LOCKED_ZONE(z)); \
                (z)->flags |= (f); \
                } while (0)
#define DNS_ZONE_CLRFLAG(z,f) do { \
                INSIST(LOCKED_ZONE(z)); \
                (z)->flags &= ~(f); \
                } while (0)
        /* XXX MPA these may need to go back into zone.h */
#define DNS_ZONEFLG_REFRESH     0x00000001U     /*%< refresh check in progress */
#define DNS_ZONEFLG_NEEDDUMP    0x00000002U     /*%< zone need consolidation */
#define DNS_ZONEFLG_USEVC       0x00000004U     /*%< use tcp for refresh query */
#define DNS_ZONEFLG_DUMPING     0x00000008U     /*%< a dump is in progress */
#define DNS_ZONEFLG_HASINCLUDE  0x00000010U     /*%< $INCLUDE in zone file */
#define DNS_ZONEFLG_LOADED      0x00000020U     /*%< database has loaded */
#define DNS_ZONEFLG_EXITING     0x00000040U     /*%< zone is being destroyed */
#define DNS_ZONEFLG_EXPIRED     0x00000080U     /*%< zone has expired */
#define DNS_ZONEFLG_NEEDREFRESH 0x00000100U     /*%< refresh check needed */
#define DNS_ZONEFLG_UPTODATE    0x00000200U     /*%< zone contents are
                                                 * uptodate */
#define DNS_ZONEFLG_NEEDNOTIFY  0x00000400U     /*%< need to send out notify
                                                 * messages */
#define DNS_ZONEFLG_DIFFONRELOAD 0x00000800U    /*%< generate a journal diff on
                                                 * reload */
#define DNS_ZONEFLG_NOMASTERS   0x00001000U     /*%< an attempt to refresh a
                                                 * zone with no masters
                                                 * occurred */
#define DNS_ZONEFLG_LOADING     0x00002000U     /*%< load from disk in progress*/
#define DNS_ZONEFLG_HAVETIMERS  0x00004000U     /*%< timer values have been set
                                                 * from SOA (if not set, we
                                                 * are still using
                                                 * default timer values) */
#define DNS_ZONEFLG_FORCEXFER   0x00008000U     /*%< Force a zone xfer */
#define DNS_ZONEFLG_NOREFRESH   0x00010000U
#define DNS_ZONEFLG_DIALNOTIFY  0x00020000U
#define DNS_ZONEFLG_DIALREFRESH 0x00040000U
#define DNS_ZONEFLG_SHUTDOWN    0x00080000U
#define DNS_ZONEFLAG_NOIXFR     0x00100000U     /*%< IXFR failed, force AXFR */
#define DNS_ZONEFLG_FLUSH       0x00200000U
#define DNS_ZONEFLG_NOEDNS      0x00400000U
#define DNS_ZONEFLG_USEALTXFRSRC 0x00800000U
#define DNS_ZONEFLG_SOABEFOREAXFR 0x01000000U
#define DNS_ZONEFLG_NEEDCOMPACT 0x02000000U
#define DNS_ZONEFLG_REFRESHING  0x04000000U     /*%< Refreshing keydata */
#define DNS_ZONEFLG_THAW        0x08000000U
/* #define DNS_ZONEFLG_XXXXX    0x10000000U   XXXMPA unused. */
#define DNS_ZONEFLG_NODELAY     0x20000000U

#define DNS_ZONE_OPTION(z,o) (((z)->options & (o)) != 0)
#define DNS_ZONEKEY_OPTION(z,o) (((z)->keyopts & (o)) != 0)

/* Flags for zone_load() */
#define DNS_ZONELOADFLAG_NOSTAT 0x00000001U     /* Do not stat() master files */
#define DNS_ZONELOADFLAG_THAW   0x00000002U     /* Thaw the zone on successful
                                                   load. */

#define UNREACH_CHACHE_SIZE     10U
#define UNREACH_HOLD_TIME       600     /* 10 minutes */

#define CHECK(op) \
        do { result = (op); \
                if (result != ISC_R_SUCCESS) goto failure; \
        } while (0)

struct dns_unreachable {
        isc_sockaddr_t  remote;
        isc_sockaddr_t  local;
        isc_uint32_t    expire;
        isc_uint32_t    last;
};

struct dns_zonemgr {
        unsigned int            magic;
        isc_mem_t *             mctx;
        int                     refs;           /* Locked by rwlock */
        isc_taskmgr_t *         taskmgr;
        isc_timermgr_t *        timermgr;
        isc_socketmgr_t *       socketmgr;
        isc_taskpool_t *        zonetasks;
        isc_task_t *            task;
        isc_ratelimiter_t *     rl;
        isc_rwlock_t            rwlock;
        isc_mutex_t             iolock;
        isc_rwlock_t            urlock;

        /* Locked by rwlock. */
        dns_zonelist_t          zones;
        dns_zonelist_t          waiting_for_xfrin;
        dns_zonelist_t          xfrin_in_progress;

        /* Configuration data. */
        isc_uint32_t            transfersin;
        isc_uint32_t            transfersperns;
        unsigned int            serialqueryrate;

        /* Locked by iolock */
        isc_uint32_t            iolimit;
        isc_uint32_t            ioactive;
        dns_iolist_t            high;
        dns_iolist_t            low;

        /* Locked by urlock. */
        /* LRU cache */
        struct dns_unreachable  unreachable[UNREACH_CHACHE_SIZE];
};

/*%
 * Hold notify state.
 */
struct dns_notify {
        unsigned int            magic;
        unsigned int            flags;
        isc_mem_t               *mctx;
        dns_zone_t              *zone;
        dns_adbfind_t           *find;
        dns_request_t           *request;
        dns_name_t              ns;
        isc_sockaddr_t          dst;
        ISC_LINK(dns_notify_t)  link;
};

#define DNS_NOTIFY_NOSOA        0x0001U

/*%
 *      dns_stub holds state while performing a 'stub' transfer.
 *      'db' is the zone's 'db' or a new one if this is the initial
 *      transfer.
 */

struct dns_stub {
        unsigned int            magic;
        isc_mem_t               *mctx;
        dns_zone_t              *zone;
        dns_db_t                *db;
        dns_dbversion_t         *version;
};

/*%
 *      Hold load state.
 */
struct dns_load {
        unsigned int            magic;
        isc_mem_t               *mctx;
        dns_zone_t              *zone;
        dns_db_t                *db;
        isc_time_t              loadtime;
        dns_rdatacallbacks_t    callbacks;
};

/*%
 *      Hold forward state.
 */
struct dns_forward {
        unsigned int            magic;
        isc_mem_t               *mctx;
        dns_zone_t              *zone;
        isc_buffer_t            *msgbuf;
        dns_request_t           *request;
        isc_uint32_t            which;
        isc_sockaddr_t          addr;
        dns_updatecallback_t    callback;
        void                    *callback_arg;
        ISC_LINK(dns_forward_t) link;
};

/*%
 *      Hold IO request state.
 */
struct dns_io {
        unsigned int    magic;
        dns_zonemgr_t   *zmgr;
        isc_boolean_t   high;
        isc_task_t      *task;
        ISC_LINK(dns_io_t) link;
        isc_event_t     *event;
};

/*%
 *      Hold state for when we are signing a zone with a new
 *      DNSKEY as result of an update.
 */
struct dns_signing {
        unsigned int            magic;
        dns_db_t                *db;
        dns_dbiterator_t        *dbiterator;
        dns_secalg_t            algorithm;
        isc_uint16_t            keyid;
        isc_boolean_t           delete;
        isc_boolean_t           done;
        ISC_LINK(dns_signing_t) link;
};

struct dns_nsec3chain {
        unsigned int                    magic;
        dns_db_t                        *db;
        dns_dbiterator_t                *dbiterator;
        dns_rdata_nsec3param_t          nsec3param;
        unsigned char                   salt[255];
        isc_boolean_t                   done;
        isc_boolean_t                   seen_nsec;
        isc_boolean_t                   delete_nsec;
        isc_boolean_t                   save_delete_nsec;
        ISC_LINK(dns_nsec3chain_t)      link;
};
/*%<
 * 'dbiterator' contains a iterator for the database.  If we are creating
 * a NSEC3 chain only the non-NSEC3 nodes will be iterated.  If we are
 * removing a NSEC3 chain then both NSEC3 and non-NSEC3 nodes will be
 * iterated.
 *
 * 'nsec3param' contains the parameters of the NSEC3 chain being created
 * or removed.
 *
 * 'salt' is buffer space and is referenced via 'nsec3param.salt'.
 *
 * 'seen_nsec' will be set to true if, while iterating the zone to create a
 * NSEC3 chain, a NSEC record is seen.
 *
 * 'delete_nsec' will be set to true if, at the completion of the creation
 * of a NSEC3 chain, 'seen_nsec' is true.  If 'delete_nsec' is true then we
 * are in the process of deleting the NSEC chain.
 *
 * 'save_delete_nsec' is used to store the initial state of 'delete_nsec'
 * so it can be recovered in the event of a error.
 */

struct dns_keyfetch {
        dns_fixedname_t name;
        dns_rdataset_t keydataset;
        dns_rdataset_t dnskeyset;
        dns_rdataset_t dnskeysigset;
        dns_zone_t *zone;
        dns_db_t *db;
        dns_fetch_t *fetch;
};

#define HOUR 3600
#define DAY (24*HOUR)
#define MONTH (30*DAY)

#define SEND_BUFFER_SIZE 2048

static void zone_settimer(dns_zone_t *, isc_time_t *);
static void cancel_refresh(dns_zone_t *);
static void zone_debuglog(dns_zone_t *zone, const char *, int debuglevel,
                          const char *msg, ...) ISC_FORMAT_PRINTF(4, 5);
static void notify_log(dns_zone_t *zone, int level, const char *fmt, ...)
     ISC_FORMAT_PRINTF(3, 4);
static void queue_xfrin(dns_zone_t *zone);
static isc_result_t update_one_rr(dns_db_t *db, dns_dbversion_t *ver,
                                  dns_diff_t *diff, dns_diffop_t op,
                                  dns_name_t *name, dns_ttl_t ttl,
                                  dns_rdata_t *rdata);
static void zone_unload(dns_zone_t *zone);
static void zone_expire(dns_zone_t *zone);
static void zone_iattach(dns_zone_t *source, dns_zone_t **target);
static void zone_idetach(dns_zone_t **zonep);
static isc_result_t zone_replacedb(dns_zone_t *zone, dns_db_t *db,
                                   isc_boolean_t dump);
static inline void zone_attachdb(dns_zone_t *zone, dns_db_t *db);
static inline void zone_detachdb(dns_zone_t *zone);
static isc_result_t default_journal(dns_zone_t *zone);
static void zone_xfrdone(dns_zone_t *zone, isc_result_t result);
static isc_result_t zone_postload(dns_zone_t *zone, dns_db_t *db,
                                  isc_time_t loadtime, isc_result_t result);
static void zone_needdump(dns_zone_t *zone, unsigned int delay);
static void zone_shutdown(isc_task_t *, isc_event_t *);
static void zone_loaddone(void *arg, isc_result_t result);
static isc_result_t zone_startload(dns_db_t *db, dns_zone_t *zone,
                                   isc_time_t loadtime);
static void zone_namerd_tostr(dns_zone_t *zone, char *buf, size_t length);
static void zone_name_tostr(dns_zone_t *zone, char *buf, size_t length);
static void zone_rdclass_tostr(dns_zone_t *zone, char *buf, size_t length);
static void zone_viewname_tostr(dns_zone_t *zone, char *buf, size_t length);

#if 0
/* ondestroy example */
static void dns_zonemgr_dbdestroyed(isc_task_t *task, isc_event_t *event);
#endif

static void refresh_callback(isc_task_t *, isc_event_t *);
static void stub_callback(isc_task_t *, isc_event_t *);
static void queue_soa_query(dns_zone_t *zone);
static void soa_query(isc_task_t *, isc_event_t *);
static void ns_query(dns_zone_t *zone, dns_rdataset_t *soardataset,
                     dns_stub_t *stub);
static int message_count(dns_message_t *msg, dns_section_t section,
                         dns_rdatatype_t type);
static void notify_cancel(dns_zone_t *zone);
static void notify_find_address(dns_notify_t *notify);
static void notify_send(dns_notify_t *notify);
static isc_result_t notify_createmessage(dns_zone_t *zone,
                                         unsigned int flags,
                                         dns_message_t **messagep);
static void notify_done(isc_task_t *task, isc_event_t *event);
static void notify_send_toaddr(isc_task_t *task, isc_event_t *event);
static isc_result_t zone_dump(dns_zone_t *, isc_boolean_t);
static void got_transfer_quota(isc_task_t *task, isc_event_t *event);
static isc_result_t zmgr_start_xfrin_ifquota(dns_zonemgr_t *zmgr,
                                             dns_zone_t *zone);
static void zmgr_resume_xfrs(dns_zonemgr_t *zmgr, isc_boolean_t multi);
static void zonemgr_free(dns_zonemgr_t *zmgr);
static isc_result_t zonemgr_getio(dns_zonemgr_t *zmgr, isc_boolean_t high,
                                  isc_task_t *task, isc_taskaction_t action,
                                  void *arg, dns_io_t **iop);
static void zonemgr_putio(dns_io_t **iop);
static void zonemgr_cancelio(dns_io_t *io);

static isc_result_t
zone_get_from_db(dns_zone_t *zone, dns_db_t *db, unsigned int *nscount,
                 unsigned int *soacount, isc_uint32_t *serial,
                 isc_uint32_t *refresh, isc_uint32_t *retry,
                 isc_uint32_t *expire, isc_uint32_t *minimum,
                 unsigned int *errors);

static void zone_freedbargs(dns_zone_t *zone);
static void forward_callback(isc_task_t *task, isc_event_t *event);
static void zone_saveunique(dns_zone_t *zone, const char *path,
                            const char *templat);
static void zone_maintenance(dns_zone_t *zone);
static void zone_notify(dns_zone_t *zone, isc_time_t *now);
static void dump_done(void *arg, isc_result_t result);
static isc_result_t zone_signwithkey(dns_zone_t *zone, dns_secalg_t algorithm,
                                     isc_uint16_t keyid, isc_boolean_t delete);
static isc_result_t delete_nsec(dns_db_t *db, dns_dbversion_t *ver,
                                dns_dbnode_t *node, dns_name_t *name,
                                dns_diff_t *diff);
static void zone_rekey(dns_zone_t *zone);
static isc_boolean_t delsig_ok(dns_rdata_rrsig_t *rrsig_ptr,
                               dst_key_t **keys, unsigned int nkeys);

#define ENTER zone_debuglog(zone, me, 1, "enter")

static const unsigned int dbargc_default = 1;
static const char *dbargv_default[] = { "rbt" };

#define DNS_ZONE_JITTER_ADD(a, b, c) \
        do { \
                isc_interval_t _i; \
                isc_uint32_t _j; \
                _j = isc_random_jitter((b), (b)/4); \
                isc_interval_set(&_i, _j, 0); \
                if (isc_time_add((a), &_i, (c)) != ISC_R_SUCCESS) { \
                        dns_zone_log(zone, ISC_LOG_WARNING, \
                                     "epoch approaching: upgrade required: " \
                                     "now + %s failed", #b); \
                        isc_interval_set(&_i, _j/2, 0); \
                        (void)isc_time_add((a), &_i, (c)); \
                } \
        } while (0)

#define DNS_ZONE_TIME_ADD(a, b, c) \
        do { \
                isc_interval_t _i; \
                isc_interval_set(&_i, (b), 0); \
                if (isc_time_add((a), &_i, (c)) != ISC_R_SUCCESS) { \
                        dns_zone_log(zone, ISC_LOG_WARNING, \
                                     "epoch approaching: upgrade required: " \
                                     "now + %s failed", #b); \
                        isc_interval_set(&_i, (b)/2, 0); \
                        (void)isc_time_add((a), &_i, (c)); \
                } \
        } while (0)

/*%
 * Increment resolver-related statistics counters.  Zone must be locked.
 */
static inline void
inc_stats(dns_zone_t *zone, isc_statscounter_t counter) {
        if (zone->stats != NULL)
                isc_stats_increment(zone->stats, counter);
}

/***
 ***    Public functions.
 ***/

isc_result_t
dns_zone_create(dns_zone_t **zonep, isc_mem_t *mctx) {
        isc_result_t result;
        dns_zone_t *zone;
        isc_time_t now;

        REQUIRE(zonep != NULL && *zonep == NULL);
        REQUIRE(mctx != NULL);

        TIME_NOW(&now);
        zone = isc_mem_get(mctx, sizeof(*zone));
        if (zone == NULL)
                return (ISC_R_NOMEMORY);

        zone->mctx = NULL;
        isc_mem_attach(mctx, &zone->mctx);

        result = isc_mutex_init(&zone->lock);
        if (result != ISC_R_SUCCESS)
                goto free_zone;

        result = ZONEDB_INITLOCK(&zone->dblock);
        if (result != ISC_R_SUCCESS)
                goto free_mutex;

        /* XXX MPA check that all elements are initialised */
#ifdef DNS_ZONE_CHECKLOCK
        zone->locked = ISC_FALSE;
#endif
        zone->db = NULL;
        zone->zmgr = NULL;
        ISC_LINK_INIT(zone, link);
        result = isc_refcount_init(&zone->erefs, 1);    /* Implicit attach. */
        if (result != ISC_R_SUCCESS)
                goto free_dblock;
        zone->irefs = 0;
        dns_name_init(&zone->origin, NULL);
        zone->strnamerd = NULL;
        zone->strname = NULL;
        zone->strrdclass = NULL;
        zone->strviewname = NULL;
        zone->masterfile = NULL;
        zone->masterformat = dns_masterformat_none;
        zone->keydirectory = NULL;
        zone->journalsize = -1;
        zone->journal = NULL;
        zone->rdclass = dns_rdataclass_none;
        zone->type = dns_zone_none;
        zone->flags = 0;
        zone->options = 0;
        zone->keyopts = 0;
        zone->db_argc = 0;
        zone->db_argv = NULL;
        isc_time_settoepoch(&zone->expiretime);
        isc_time_settoepoch(&zone->refreshtime);
        isc_time_settoepoch(&zone->dumptime);
        isc_time_settoepoch(&zone->loadtime);
        zone->notifytime = now;
        isc_time_settoepoch(&zone->resigntime);
        isc_time_settoepoch(&zone->keywarntime);
        isc_time_settoepoch(&zone->signingtime);
        isc_time_settoepoch(&zone->nsec3chaintime);
        isc_time_settoepoch(&zone->refreshkeytime);
        zone->refreshkeycount = 0;
        zone->refresh = DNS_ZONE_DEFAULTREFRESH;
        zone->retry = DNS_ZONE_DEFAULTRETRY;
        zone->expire = 0;
        zone->minimum = 0;
        zone->maxrefresh = DNS_ZONE_MAXREFRESH;
        zone->minrefresh = DNS_ZONE_MINREFRESH;
        zone->maxretry = DNS_ZONE_MAXRETRY;
        zone->minretry = DNS_ZONE_MINRETRY;
        zone->masters = NULL;
        zone->masterkeynames = NULL;
        zone->mastersok = NULL;
        zone->masterscnt = 0;
        zone->curmaster = 0;
        zone->notify = NULL;
        zone->notifytype = dns_notifytype_yes;
        zone->notifycnt = 0;
        zone->task = NULL;
        zone->update_acl = NULL;
        zone->forward_acl = NULL;
        zone->notify_acl = NULL;
        zone->query_acl = NULL;
        zone->queryon_acl = NULL;
        zone->xfr_acl = NULL;
        zone->update_disabled = ISC_FALSE;
        zone->zero_no_soa_ttl = ISC_TRUE;
        zone->check_names = dns_severity_ignore;
        zone->request = NULL;
        zone->lctx = NULL;
        zone->readio = NULL;
        zone->dctx = NULL;
        zone->writeio = NULL;
        zone->timer = NULL;
        zone->idlein = DNS_DEFAULT_IDLEIN;
        zone->idleout = DNS_DEFAULT_IDLEOUT;
        zone->log_key_expired_timer = 0;
        ISC_LIST_INIT(zone->notifies);
        isc_sockaddr_any(&zone->notifysrc4);
        isc_sockaddr_any6(&zone->notifysrc6);
        isc_sockaddr_any(&zone->xfrsource4);
        isc_sockaddr_any6(&zone->xfrsource6);
        isc_sockaddr_any(&zone->altxfrsource4);
        isc_sockaddr_any6(&zone->altxfrsource6);
        zone->xfr = NULL;
        zone->tsigkey = NULL;
        zone->maxxfrin = MAX_XFER_TIME;
        zone->maxxfrout = MAX_XFER_TIME;
        zone->ssutable = NULL;
        zone->sigvalidityinterval = 30 * 24 * 3600;
        zone->sigresigninginterval = 7 * 24 * 3600;
        zone->view = NULL;
        zone->acache = NULL;
        zone->checkmx = NULL;
        zone->checksrv = NULL;
        zone->checkns = NULL;
        ISC_LINK_INIT(zone, statelink);
        zone->statelist = NULL;
        zone->stats = NULL;
        zone->requeststats_on = ISC_FALSE;
        zone->requeststats = NULL;
        zone->notifydelay = 5;
        zone->isself = NULL;
        zone->isselfarg = NULL;
        ISC_LIST_INIT(zone->signing);
        ISC_LIST_INIT(zone->nsec3chain);
        zone->signatures = 10;
        zone->nodes = 100;
        zone->privatetype = (dns_rdatatype_t)0xffffU;
        zone->added = ISC_FALSE;
        zone->rpz_zone = ISC_FALSE;
        ISC_LIST_INIT(zone->forwards);

        zone->magic = ZONE_MAGIC;

        /* Must be after magic is set. */
        result = dns_zone_setdbtype(zone, dbargc_default, dbargv_default);
        if (result != ISC_R_SUCCESS)
                goto free_erefs;

        ISC_EVENT_INIT(&zone->ctlevent, sizeof(zone->ctlevent), 0, NULL,
                       DNS_EVENT_ZONECONTROL, zone_shutdown, zone, zone,
                       NULL, NULL);
        *zonep = zone;
        return (ISC_R_SUCCESS);

 free_erefs:
        isc_refcount_decrement(&zone->erefs, NULL);
        isc_refcount_destroy(&zone->erefs);

 free_dblock:
        ZONEDB_DESTROYLOCK(&zone->dblock);

 free_mutex:
        DESTROYLOCK(&zone->lock);

 free_zone:
        isc_mem_putanddetach(&zone->mctx, zone, sizeof(*zone));
        return (result);
}

/*
 * Free a zone.  Because we require that there be no more
 * outstanding events or references, no locking is necessary.
 */
static void
zone_free(dns_zone_t *zone) {
        isc_mem_t *mctx = NULL;
        dns_signing_t *signing;
        dns_nsec3chain_t *nsec3chain;

        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(isc_refcount_current(&zone->erefs) == 0);
        REQUIRE(zone->irefs == 0);
        REQUIRE(!LOCKED_ZONE(zone));
        REQUIRE(zone->timer == NULL);

        /*
         * Managed objects.  Order is important.
         */
        if (zone->request != NULL)
                dns_request_destroy(&zone->request); /* XXXMPA */
        INSIST(zone->readio == NULL);
        INSIST(zone->statelist == NULL);
        INSIST(zone->writeio == NULL);

        if (zone->task != NULL)
                isc_task_detach(&zone->task);
        if (zone->zmgr != NULL)
                dns_zonemgr_releasezone(zone->zmgr, zone);

        /* Unmanaged objects */
        for (signing = ISC_LIST_HEAD(zone->signing);
             signing != NULL;
             signing = ISC_LIST_HEAD(zone->signing)) {
                ISC_LIST_UNLINK(zone->signing, signing, link);
                dns_db_detach(&signing->db);
                dns_dbiterator_destroy(&signing->dbiterator);
                isc_mem_put(zone->mctx, signing, sizeof *signing);
        }
        for (nsec3chain = ISC_LIST_HEAD(zone->nsec3chain);
             nsec3chain != NULL;
             nsec3chain = ISC_LIST_HEAD(zone->nsec3chain)) {
                ISC_LIST_UNLINK(zone->nsec3chain, nsec3chain, link);
                dns_db_detach(&nsec3chain->db);
                dns_dbiterator_destroy(&nsec3chain->dbiterator);
                isc_mem_put(zone->mctx, nsec3chain, sizeof *nsec3chain);
        }
        if (zone->masterfile != NULL)
                isc_mem_free(zone->mctx, zone->masterfile);
        zone->masterfile = NULL;
        if (zone->keydirectory != NULL)
                isc_mem_free(zone->mctx, zone->keydirectory);
        zone->keydirectory = NULL;
        zone->journalsize = -1;
        if (zone->journal != NULL)
                isc_mem_free(zone->mctx, zone->journal);
        zone->journal = NULL;
        if (zone->stats != NULL)
                isc_stats_detach(&zone->stats);
        if (zone->requeststats != NULL)
                isc_stats_detach(&zone->requeststats);
        if (zone->db != NULL)
                zone_detachdb(zone);
        if (zone->acache != NULL)
                dns_acache_detach(&zone->acache);
        zone_freedbargs(zone);
        RUNTIME_CHECK(dns_zone_setmasterswithkeys(zone, NULL, NULL, 0)
                      == ISC_R_SUCCESS);
        RUNTIME_CHECK(dns_zone_setalsonotify(zone, NULL, 0)
                      == ISC_R_SUCCESS);
        zone->check_names = dns_severity_ignore;
        if (zone->update_acl != NULL)
                dns_acl_detach(&zone->update_acl);
        if (zone->forward_acl != NULL)
                dns_acl_detach(&zone->forward_acl);
        if (zone->notify_acl != NULL)
                dns_acl_detach(&zone->notify_acl);
        if (zone->query_acl != NULL)
                dns_acl_detach(&zone->query_acl);
        if (zone->queryon_acl != NULL)
                dns_acl_detach(&zone->queryon_acl);
        if (zone->xfr_acl != NULL)
                dns_acl_detach(&zone->xfr_acl);
        if (dns_name_dynamic(&zone->origin))
                dns_name_free(&zone->origin, zone->mctx);
        if (zone->strnamerd != NULL)
                isc_mem_free(zone->mctx, zone->strnamerd);
        if (zone->strname != NULL)
                isc_mem_free(zone->mctx, zone->strname);
        if (zone->strrdclass != NULL)
                isc_mem_free(zone->mctx, zone->strrdclass);
        if (zone->strviewname != NULL)
                isc_mem_free(zone->mctx, zone->strviewname);
        if (zone->ssutable != NULL)
                dns_ssutable_detach(&zone->ssutable);

        /* last stuff */
        ZONEDB_DESTROYLOCK(&zone->dblock);
        DESTROYLOCK(&zone->lock);
        isc_refcount_destroy(&zone->erefs);
        zone->magic = 0;
        mctx = zone->mctx;
        isc_mem_put(mctx, zone, sizeof(*zone));
        isc_mem_detach(&mctx);
}

/*
 *      Single shot.
 */
void
dns_zone_setclass(dns_zone_t *zone, dns_rdataclass_t rdclass) {
        char namebuf[1024];

        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(rdclass != dns_rdataclass_none);

        /*
         * Test and set.
         */
        LOCK_ZONE(zone);
        REQUIRE(zone->rdclass == dns_rdataclass_none ||
                zone->rdclass == rdclass);
        zone->rdclass = rdclass;

        if (zone->strnamerd != NULL)
                isc_mem_free(zone->mctx, zone->strnamerd);
        if (zone->strrdclass != NULL)
                isc_mem_free(zone->mctx, zone->strrdclass);

        zone_namerd_tostr(zone, namebuf, sizeof namebuf);
        zone->strnamerd = isc_mem_strdup(zone->mctx, namebuf);
        zone_rdclass_tostr(zone, namebuf, sizeof namebuf);
        zone->strrdclass = isc_mem_strdup(zone->mctx, namebuf);

        UNLOCK_ZONE(zone);
}

dns_rdataclass_t
dns_zone_getclass(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->rdclass);
}

void
dns_zone_setnotifytype(dns_zone_t *zone, dns_notifytype_t notifytype) {
        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        zone->notifytype = notifytype;
        UNLOCK_ZONE(zone);
}

isc_result_t
dns_zone_getserial2(dns_zone_t *zone, isc_uint32_t *serialp) {
        isc_result_t result;

        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(serialp != NULL);

        LOCK_ZONE(zone);
        ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
        if (zone->db != NULL) {
                result = zone_get_from_db(zone, zone->db, NULL, NULL, serialp,
                                          NULL, NULL, NULL, NULL, NULL);
        } else
                result = DNS_R_NOTLOADED;
        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
        UNLOCK_ZONE(zone);

        return (result);
}

isc_uint32_t
dns_zone_getserial(dns_zone_t *zone) {
        isc_result_t result;
        isc_uint32_t serial;

        result = dns_zone_getserial2(zone, &serial);
        if (result != ISC_R_SUCCESS)
                serial = 0; /* XXX: not really correct, but no other choice */

        return (serial);
}

/*
 *      Single shot.
 */
void
dns_zone_settype(dns_zone_t *zone, dns_zonetype_t type) {

        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(type != dns_zone_none);

        /*
         * Test and set.
         */
        LOCK_ZONE(zone);
        REQUIRE(zone->type == dns_zone_none || zone->type == type);
        zone->type = type;
        UNLOCK_ZONE(zone);
}

static void
zone_freedbargs(dns_zone_t *zone) {
        unsigned int i;

        /* Free the old database argument list. */
        if (zone->db_argv != NULL) {
                for (i = 0; i < zone->db_argc; i++)
                        isc_mem_free(zone->mctx, zone->db_argv[i]);
                isc_mem_put(zone->mctx, zone->db_argv,
                            zone->db_argc * sizeof(*zone->db_argv));
        }
        zone->db_argc = 0;
        zone->db_argv = NULL;
}

isc_result_t
dns_zone_getdbtype(dns_zone_t *zone, char ***argv, isc_mem_t *mctx) {
        size_t size = 0;
        unsigned int i;
        isc_result_t result = ISC_R_SUCCESS;
        void *mem;
        char **tmp, *tmp2;

        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(argv != NULL && *argv == NULL);

        LOCK_ZONE(zone);
        size = (zone->db_argc + 1) * sizeof(char *);
        for (i = 0; i < zone->db_argc; i++)
                size += strlen(zone->db_argv[i]) + 1;
        mem = isc_mem_allocate(mctx, size);
        if (mem != NULL) {
                tmp = mem;
                tmp2 = mem;
                tmp2 += (zone->db_argc + 1) * sizeof(char *);
                for (i = 0; i < zone->db_argc; i++) {
                        *tmp++ = tmp2;
                        strcpy(tmp2, zone->db_argv[i]);
                        tmp2 += strlen(tmp2) + 1;
                }
                *tmp = NULL;
        } else
                result = ISC_R_NOMEMORY;
        UNLOCK_ZONE(zone);
        *argv = mem;
        return (result);
}

isc_result_t
dns_zone_setdbtype(dns_zone_t *zone,
                   unsigned int dbargc, const char * const *dbargv) {
        isc_result_t result = ISC_R_SUCCESS;
        char **new = NULL;
        unsigned int i;

        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(dbargc >= 1);
        REQUIRE(dbargv != NULL);

        LOCK_ZONE(zone);

        /* Set up a new database argument list. */
        new = isc_mem_get(zone->mctx, dbargc * sizeof(*new));
        if (new == NULL)
                goto nomem;
        for (i = 0; i < dbargc; i++)
                new[i] = NULL;
        for (i = 0; i < dbargc; i++) {
                new[i] = isc_mem_strdup(zone->mctx, dbargv[i]);
                if (new[i] == NULL)
                        goto nomem;
        }

        /* Free the old list. */
        zone_freedbargs(zone);

        zone->db_argc = dbargc;
        zone->db_argv = new;
        result = ISC_R_SUCCESS;
        goto unlock;

 nomem:
        if (new != NULL) {
                for (i = 0; i < dbargc; i++)
                        if (new[i] != NULL)
                                isc_mem_free(zone->mctx, new[i]);
                isc_mem_put(zone->mctx, new, dbargc * sizeof(*new));
        }
        result = ISC_R_NOMEMORY;

 unlock:
        UNLOCK_ZONE(zone);
        return (result);
}

void
dns_zone_setview(dns_zone_t *zone, dns_view_t *view) {
        char namebuf[1024];
        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        if (zone->view != NULL)
                dns_view_weakdetach(&zone->view);
        dns_view_weakattach(view, &zone->view);

        if (zone->strviewname != NULL)
                isc_mem_free(zone->mctx, zone->strviewname);
        if (zone->strnamerd != NULL)
                isc_mem_free(zone->mctx, zone->strnamerd);

        zone_namerd_tostr(zone, namebuf, sizeof namebuf);
        zone->strnamerd = isc_mem_strdup(zone->mctx, namebuf);
        zone_viewname_tostr(zone, namebuf, sizeof namebuf);
        zone->strviewname = isc_mem_strdup(zone->mctx, namebuf);

        UNLOCK_ZONE(zone);
}


dns_view_t *
dns_zone_getview(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->view);
}


isc_result_t
dns_zone_setorigin(dns_zone_t *zone, const dns_name_t *origin) {
        isc_result_t result;
        char namebuf[1024];

        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(origin != NULL);

        LOCK_ZONE(zone);
        if (dns_name_dynamic(&zone->origin)) {
                dns_name_free(&zone->origin, zone->mctx);
                dns_name_init(&zone->origin, NULL);
        }
        result = dns_name_dup(origin, zone->mctx, &zone->origin);

        if (zone->strnamerd != NULL)
                isc_mem_free(zone->mctx, zone->strnamerd);
        if (zone->strname != NULL)
                isc_mem_free(zone->mctx, zone->strname);

        zone_namerd_tostr(zone, namebuf, sizeof namebuf);
        zone->strnamerd = isc_mem_strdup(zone->mctx, namebuf);
        zone_name_tostr(zone, namebuf, sizeof namebuf);
        zone->strname = isc_mem_strdup(zone->mctx, namebuf);

        UNLOCK_ZONE(zone);
        return (result);
}

void
dns_zone_setacache(dns_zone_t *zone, dns_acache_t *acache) {
        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(acache != NULL);

        LOCK_ZONE(zone);
        if (zone->acache != NULL)
                dns_acache_detach(&zone->acache);
        dns_acache_attach(acache, &zone->acache);
        ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
        if (zone->db != NULL) {
                isc_result_t result;

                /*
                 * If the zone reuses an existing DB, the DB needs to be
                 * set in the acache explicitly.  We can safely ignore the
                 * case where the DB is already set.  If other error happens,
                 * the acache will not work effectively.
                 */
                result = dns_acache_setdb(acache, zone->db);
                if (result != ISC_R_SUCCESS && result != ISC_R_EXISTS) {
                        UNEXPECTED_ERROR(__FILE__, __LINE__,
                                         "dns_acache_setdb() failed: %s",
                                         isc_result_totext(result));
                }
        }
        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
        UNLOCK_ZONE(zone);
}

static isc_result_t
dns_zone_setstring(dns_zone_t *zone, char **field, const char *value) {
        char *copy;

        if (value != NULL) {
                copy = isc_mem_strdup(zone->mctx, value);
                if (copy == NULL)
                        return (ISC_R_NOMEMORY);
        } else {
                copy = NULL;
        }

        if (*field != NULL)
                isc_mem_free(zone->mctx, *field);

        *field = copy;
        return (ISC_R_SUCCESS);
}

isc_result_t
dns_zone_setfile(dns_zone_t *zone, const char *file) {
        return (dns_zone_setfile2(zone, file, dns_masterformat_text));
}

isc_result_t
dns_zone_setfile2(dns_zone_t *zone, const char *file,
                  dns_masterformat_t format) {
        isc_result_t result = ISC_R_SUCCESS;

        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        result = dns_zone_setstring(zone, &zone->masterfile, file);
        if (result == ISC_R_SUCCESS) {
                zone->masterformat = format;
                result = default_journal(zone);
        }
        UNLOCK_ZONE(zone);

        return (result);
}

const char *
dns_zone_getfile(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->masterfile);
}

static isc_result_t
default_journal(dns_zone_t *zone) {
        isc_result_t result;
        char *journal;

        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(LOCKED_ZONE(zone));

        if (zone->masterfile != NULL) {
                /* Calculate string length including '\0'. */
                int len = strlen(zone->masterfile) + sizeof(".jnl");
                journal = isc_mem_allocate(zone->mctx, len);
                if (journal == NULL)
                        return (ISC_R_NOMEMORY);
                strcpy(journal, zone->masterfile);
                strcat(journal, ".jnl");
        } else {
                journal = NULL;
        }
        result = dns_zone_setstring(zone, &zone->journal, journal);
        if (journal != NULL)
                isc_mem_free(zone->mctx, journal);
        return (result);
}

isc_result_t
dns_zone_setjournal(dns_zone_t *zone, const char *journal) {
        isc_result_t result = ISC_R_SUCCESS;

        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        result = dns_zone_setstring(zone, &zone->journal, journal);
        UNLOCK_ZONE(zone);

        return (result);
}

char *
dns_zone_getjournal(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->journal);
}

/*
 * Return true iff the zone is "dynamic", in the sense that the zone's
 * master file (if any) is written by the server, rather than being
 * updated manually and read by the server.
 *
 * This is true for slave zones, stub zones, key zones, and zones that
 * allow dynamic updates either by having an update policy ("ssutable")
 * or an "allow-update" ACL with a value other than exactly "{ none; }".
 */
static isc_boolean_t
zone_isdynamic(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        return (ISC_TF(zone->type == dns_zone_slave ||
                       zone->type == dns_zone_stub ||
                       zone->type == dns_zone_key ||
                       (!zone->update_disabled && zone->ssutable != NULL) ||
                       (!zone->update_disabled && zone->update_acl != NULL &&
                        !dns_acl_isnone(zone->update_acl))));
}


static isc_result_t
zone_load(dns_zone_t *zone, unsigned int flags) {
        isc_result_t result;
        isc_time_t now;
        isc_time_t loadtime, filetime;
        dns_db_t *db = NULL;
        isc_boolean_t rbt;

        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        TIME_NOW(&now);

        INSIST(zone->type != dns_zone_none);

        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADING)) {
                if ((flags & DNS_ZONELOADFLAG_THAW) != 0)
                        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_THAW);
                result = DNS_R_CONTINUE;
                goto cleanup;
        }


        INSIST(zone->db_argc >= 1);

        rbt = strcmp(zone->db_argv[0], "rbt") == 0 ||
              strcmp(zone->db_argv[0], "rbt64") == 0;

        if (zone->db != NULL && zone->masterfile == NULL && rbt) {
                /*
                 * The zone has no master file configured.
                 */
                result = ISC_R_SUCCESS;
                goto cleanup;
        }

        if (zone->db != NULL && zone_isdynamic(zone)) {
                /*
                 * This is a slave, stub, or dynamically updated
                 * zone being reloaded.  Do nothing - the database
                 * we already have is guaranteed to be up-to-date.
                 */
                if (zone->type == dns_zone_master)
                        result = DNS_R_DYNAMIC;
                else
                        result = ISC_R_SUCCESS;
                goto cleanup;
        }

        /*
         * Store the current time before the zone is loaded, so that if the
         * file changes between the time of the load and the time that
         * zone->loadtime is set, then the file will still be reloaded
         * the next time dns_zone_load is called.
         */
        TIME_NOW(&loadtime);

        /*
         * Don't do the load if the file that stores the zone is older
         * than the last time the zone was loaded.  If the zone has not
         * been loaded yet, zone->loadtime will be the epoch.
         */
        if (zone->masterfile != NULL) {
                /*
                 * The file is already loaded.  If we are just doing a
                 * "rndc reconfig", we are done.
                 */
                if (!isc_time_isepoch(&zone->loadtime) &&
                    (flags & DNS_ZONELOADFLAG_NOSTAT) != 0 &&
                    zone->rpz_zone == dns_rpz_needed()) {
                        result = ISC_R_SUCCESS;
                        goto cleanup;
                }

                result = isc_file_getmodtime(zone->masterfile, &filetime);
                if (result == ISC_R_SUCCESS) {
                        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED) &&
                            !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_HASINCLUDE) &&
                            isc_time_compare(&filetime, &zone->loadtime) <= 0 &&
                            zone->rpz_zone == dns_rpz_needed()) {
                                dns_zone_log(zone, ISC_LOG_DEBUG(1),
                                             "skipping load: master file "
                                             "older than last load");
                                result = DNS_R_UPTODATE;
                                goto cleanup;
                        }
                        loadtime = filetime;
                        zone->rpz_zone = dns_rpz_needed();
                }
        }

        /*
         * Built in zones (with the exception of empty zones) don't need
         * to be reloaded.
         */
        if (zone->type == dns_zone_master &&
            strcmp(zone->db_argv[0], "_builtin") == 0 &&
            (zone->db_argc < 2 || strcmp(zone->db_argv[1], "empty") != 0) &&
            DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED)) {
                result = ISC_R_SUCCESS;
                goto cleanup;
        }

        if ((zone->type == dns_zone_slave || zone->type == dns_zone_stub) &&
            rbt) {
                if (zone->masterfile == NULL ||
                    !isc_file_exists(zone->masterfile)) {
                        if (zone->masterfile != NULL) {
                                dns_zone_log(zone, ISC_LOG_DEBUG(1),
                                             "no master file");
                        }
                        zone->refreshtime = now;
                        if (zone->task != NULL)
                                zone_settimer(zone, &now);
                        result = ISC_R_SUCCESS;
                        goto cleanup;
                }
        }

        dns_zone_log(zone, ISC_LOG_DEBUG(1), "starting load");

        result = dns_db_create(zone->mctx, zone->db_argv[0],
                               &zone->origin, (zone->type == dns_zone_stub) ?
                               dns_dbtype_stub : dns_dbtype_zone,
                               zone->rdclass,
                               zone->db_argc - 1, zone->db_argv + 1,
                               &db);

        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "loading zone: creating database: %s",
                             isc_result_totext(result));
                goto cleanup;
        }
        dns_db_settask(db, zone->task);

        if (! dns_db_ispersistent(db)) {
                if (zone->masterfile != NULL) {
                        result = zone_startload(db, zone, loadtime);
                } else {
                        result = DNS_R_NOMASTERFILE;
                        if (zone->type == dns_zone_master) {
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "loading zone: "
                                             "no master file configured");
                                goto cleanup;
                        }
                        dns_zone_log(zone, ISC_LOG_INFO, "loading zone: "
                                     "no master file configured: continuing");
                }
        }

        if (result == DNS_R_CONTINUE) {
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_LOADING);
                if ((flags & DNS_ZONELOADFLAG_THAW) != 0)
                        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_THAW);
                goto cleanup;
        }

        result = zone_postload(zone, db, loadtime, result);

 cleanup:
        UNLOCK_ZONE(zone);
        if (db != NULL)
                dns_db_detach(&db);
        return (result);
}

isc_result_t
dns_zone_load(dns_zone_t *zone) {
        return (zone_load(zone, 0));
}

isc_result_t
dns_zone_loadnew(dns_zone_t *zone) {
        return (zone_load(zone, DNS_ZONELOADFLAG_NOSTAT));
}

isc_result_t
dns_zone_loadandthaw(dns_zone_t *zone) {
        isc_result_t result;

        result = zone_load(zone, DNS_ZONELOADFLAG_THAW);
        switch (result) {
        case DNS_R_CONTINUE:
                /* Deferred thaw. */
                break;
        case ISC_R_SUCCESS:
        case DNS_R_UPTODATE:
        case DNS_R_SEENINCLUDE:
                zone->update_disabled = ISC_FALSE;
                break;
        case DNS_R_NOMASTERFILE:
                zone->update_disabled = ISC_FALSE;
                break;
        default:
                /* Error, remain in disabled state. */
                break;
        }
        return (result);
}

static unsigned int
get_master_options(dns_zone_t *zone) {
        unsigned int options;

        options = DNS_MASTER_ZONE;
        if (zone->type == dns_zone_slave)
                options |= DNS_MASTER_SLAVE;
        if (zone->type == dns_zone_key)
                options |= DNS_MASTER_KEY;
        if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKNS))
                options |= DNS_MASTER_CHECKNS;
        if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_FATALNS))
                options |= DNS_MASTER_FATALNS;
        if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKNAMES))
                options |= DNS_MASTER_CHECKNAMES;
        if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKNAMESFAIL))
                options |= DNS_MASTER_CHECKNAMESFAIL;
        if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKMX))
                options |= DNS_MASTER_CHECKMX;
        if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKMXFAIL))
                options |= DNS_MASTER_CHECKMXFAIL;
        if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKWILDCARD))
                options |= DNS_MASTER_CHECKWILDCARD;
        if (zone->type == dns_zone_master &&
            ((zone->update_acl != NULL && !dns_acl_isnone(zone->update_acl)) ||
              zone->ssutable != NULL))
                options |= DNS_MASTER_RESIGN;
        return (options);
}

static void
zone_gotreadhandle(isc_task_t *task, isc_event_t *event) {
        dns_load_t *load = event->ev_arg;
        isc_result_t result = ISC_R_SUCCESS;
        unsigned int options;

        REQUIRE(DNS_LOAD_VALID(load));

        if ((event->ev_attributes & ISC_EVENTATTR_CANCELED) != 0)
                result = ISC_R_CANCELED;
        isc_event_free(&event);
        if (result == ISC_R_CANCELED)
                goto fail;

        options = get_master_options(load->zone);

        result = dns_master_loadfileinc3(load->zone->masterfile,
                                         dns_db_origin(load->db),
                                         dns_db_origin(load->db),
                                         load->zone->rdclass,
                                         options,
                                         load->zone->sigresigninginterval,
                                         &load->callbacks, task,
                                         zone_loaddone, load,
                                         &load->zone->lctx, load->zone->mctx,
                                         load->zone->masterformat);
        if (result != ISC_R_SUCCESS && result != DNS_R_CONTINUE &&
            result != DNS_R_SEENINCLUDE)
                goto fail;
        return;

 fail:
        zone_loaddone(load, result);
}

static void
zone_gotwritehandle(isc_task_t *task, isc_event_t *event) {
        const char me[] = "zone_gotwritehandle";
        dns_zone_t *zone = event->ev_arg;
        isc_result_t result = ISC_R_SUCCESS;
        dns_dbversion_t *version = NULL;

        REQUIRE(DNS_ZONE_VALID(zone));
        INSIST(task == zone->task);
        ENTER;

        if ((event->ev_attributes & ISC_EVENTATTR_CANCELED) != 0)
                result = ISC_R_CANCELED;
        isc_event_free(&event);
        if (result == ISC_R_CANCELED)
                goto fail;

        LOCK_ZONE(zone);
        ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
        if (zone->db != NULL) {
                dns_db_currentversion(zone->db, &version);
                result = dns_master_dumpinc2(zone->mctx, zone->db, version,
                                             &dns_master_style_default,
                                             zone->masterfile, zone->task,
                                             dump_done, zone, &zone->dctx,
                                             zone->masterformat);
                dns_db_closeversion(zone->db, &version, ISC_FALSE);
        } else
                result = ISC_R_CANCELED;
        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
        UNLOCK_ZONE(zone);
        if (result != DNS_R_CONTINUE)
                goto fail;
        return;

 fail:
        dump_done(zone, result);
}

static isc_result_t
zone_startload(dns_db_t *db, dns_zone_t *zone, isc_time_t loadtime) {
        dns_load_t *load;
        isc_result_t result;
        isc_result_t tresult;
        unsigned int options;

        options = get_master_options(zone);

        if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_MANYERRORS))
                options |= DNS_MASTER_MANYERRORS;

        if (zone->zmgr != NULL && zone->db != NULL && zone->task != NULL) {
                load = isc_mem_get(zone->mctx, sizeof(*load));
                if (load == NULL)
                        return (ISC_R_NOMEMORY);

                load->mctx = NULL;
                load->zone = NULL;
                load->db = NULL;
                load->loadtime = loadtime;
                load->magic = LOAD_MAGIC;

                isc_mem_attach(zone->mctx, &load->mctx);
                zone_iattach(zone, &load->zone);
                dns_db_attach(db, &load->db);
                dns_rdatacallbacks_init(&load->callbacks);
                result = dns_db_beginload(db, &load->callbacks.add,
                                          &load->callbacks.add_private);
                if (result != ISC_R_SUCCESS)
                        goto cleanup;
                result = zonemgr_getio(zone->zmgr, ISC_TRUE, zone->task,
                                       zone_gotreadhandle, load,
                                       &zone->readio);
                if (result != ISC_R_SUCCESS) {
                        /*
                         * We can't report multiple errors so ignore
                         * the result of dns_db_endload().
                         */
                        (void)dns_db_endload(load->db,
                                             &load->callbacks.add_private);
                        goto cleanup;
                } else
                        result = DNS_R_CONTINUE;
        } else {
                dns_rdatacallbacks_t callbacks;

                dns_rdatacallbacks_init(&callbacks);
                result = dns_db_beginload(db, &callbacks.add,
                                          &callbacks.add_private);
                if (result != ISC_R_SUCCESS)
                        return (result);
                result = dns_master_loadfile3(zone->masterfile, &zone->origin,
                                              &zone->origin, zone->rdclass,
                                              options, zone->sigresigninginterval,
                                              &callbacks, zone->mctx,
                                              zone->masterformat);
                tresult = dns_db_endload(db, &callbacks.add_private);
                if (result == ISC_R_SUCCESS)
                        result = tresult;
        }

        return (result);

 cleanup:
        load->magic = 0;
        dns_db_detach(&load->db);
        zone_idetach(&load->zone);
        isc_mem_detach(&load->mctx);
        isc_mem_put(zone->mctx, load, sizeof(*load));
        return (result);
}

static isc_boolean_t
zone_check_mx(dns_zone_t *zone, dns_db_t *db, dns_name_t *name,
              dns_name_t *owner)
{
        isc_result_t result;
        char ownerbuf[DNS_NAME_FORMATSIZE];
        char namebuf[DNS_NAME_FORMATSIZE];
        char altbuf[DNS_NAME_FORMATSIZE];
        dns_fixedname_t fixed;
        dns_name_t *foundname;
        int level;

        /*
         * "." means the services does not exist.
         */
        if (dns_name_equal(name, dns_rootname))
                return (ISC_TRUE);

        /*
         * Outside of zone.
         */
        if (!dns_name_issubdomain(name, &zone->origin)) {
                if (zone->checkmx != NULL)
                        return ((zone->checkmx)(zone, name, owner));
                return (ISC_TRUE);
        }

        if (zone->type == dns_zone_master)
                level = ISC_LOG_ERROR;
        else
                level = ISC_LOG_WARNING;

        dns_fixedname_init(&fixed);
        foundname = dns_fixedname_name(&fixed);

        result = dns_db_find(db, name, NULL, dns_rdatatype_a,
                             0, 0, NULL, foundname, NULL, NULL);
        if (result == ISC_R_SUCCESS)
                return (ISC_TRUE);

        if (result == DNS_R_NXRRSET) {
                result = dns_db_find(db, name, NULL, dns_rdatatype_aaaa,
                                     0, 0, NULL, foundname, NULL, NULL);
                if (result == ISC_R_SUCCESS)
                        return (ISC_TRUE);
        }

        dns_name_format(owner, ownerbuf, sizeof ownerbuf);
        dns_name_format(name, namebuf, sizeof namebuf);
        if (result == DNS_R_NXRRSET || result == DNS_R_NXDOMAIN ||
            result == DNS_R_EMPTYNAME) {
                if (!DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKMXFAIL))
                        level = ISC_LOG_WARNING;
                dns_zone_log(zone, level,
                             "%s/MX '%s' has no address records (A or AAAA)",
                             ownerbuf, namebuf);
                return ((level == ISC_LOG_WARNING) ? ISC_TRUE : ISC_FALSE);
        }

        if (result == DNS_R_CNAME) {
                if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_WARNMXCNAME) ||
                    DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IGNOREMXCNAME))
                        level = ISC_LOG_WARNING;
                if (!DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IGNOREMXCNAME))
                        dns_zone_log(zone, level,
                                     "%s/MX '%s' is a CNAME (illegal)",
                                     ownerbuf, namebuf);
                return ((level == ISC_LOG_WARNING) ? ISC_TRUE : ISC_FALSE);
        }

        if (result == DNS_R_DNAME) {
                if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_WARNMXCNAME) ||
                    DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IGNOREMXCNAME))
                        level = ISC_LOG_WARNING;
                if (!DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IGNOREMXCNAME)) {
                        dns_name_format(foundname, altbuf, sizeof altbuf);
                        dns_zone_log(zone, level, "%s/MX '%s' is below a DNAME"
                                     " '%s' (illegal)", ownerbuf, namebuf,
                                     altbuf);
                }
                return ((level == ISC_LOG_WARNING) ? ISC_TRUE : ISC_FALSE);
        }

        if (zone->checkmx != NULL && result == DNS_R_DELEGATION)
                return ((zone->checkmx)(zone, name, owner));

        return (ISC_TRUE);
}

static isc_boolean_t
zone_check_srv(dns_zone_t *zone, dns_db_t *db, dns_name_t *name,
               dns_name_t *owner)
{
        isc_result_t result;
        char ownerbuf[DNS_NAME_FORMATSIZE];
        char namebuf[DNS_NAME_FORMATSIZE];
        char altbuf[DNS_NAME_FORMATSIZE];
        dns_fixedname_t fixed;
        dns_name_t *foundname;
        int level;

        /*
         * "." means the services does not exist.
         */
        if (dns_name_equal(name, dns_rootname))
                return (ISC_TRUE);

        /*
         * Outside of zone.
         */
        if (!dns_name_issubdomain(name, &zone->origin)) {
                if (zone->checksrv != NULL)
                        return ((zone->checksrv)(zone, name, owner));
                return (ISC_TRUE);
        }

        if (zone->type == dns_zone_master)
                level = ISC_LOG_ERROR;
        else
                level = ISC_LOG_WARNING;

        dns_fixedname_init(&fixed);
        foundname = dns_fixedname_name(&fixed);

        result = dns_db_find(db, name, NULL, dns_rdatatype_a,
                             0, 0, NULL, foundname, NULL, NULL);
        if (result == ISC_R_SUCCESS)
                return (ISC_TRUE);

        if (result == DNS_R_NXRRSET) {
                result = dns_db_find(db, name, NULL, dns_rdatatype_aaaa,
                                     0, 0, NULL, foundname, NULL, NULL);
                if (result == ISC_R_SUCCESS)
                        return (ISC_TRUE);
        }

        dns_name_format(owner, ownerbuf, sizeof ownerbuf);
        dns_name_format(name, namebuf, sizeof namebuf);
        if (result == DNS_R_NXRRSET || result == DNS_R_NXDOMAIN ||
            result == DNS_R_EMPTYNAME) {
                dns_zone_log(zone, level,
                             "%s/SRV '%s' has no address records (A or AAAA)",
                             ownerbuf, namebuf);
                /* XXX950 make fatal for 9.5.0. */
                return (ISC_TRUE);
        }

        if (result == DNS_R_CNAME) {
                if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_WARNSRVCNAME) ||
                    DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IGNORESRVCNAME))
                        level = ISC_LOG_WARNING;
                if (!DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IGNORESRVCNAME))
                        dns_zone_log(zone, level,
                                     "%s/SRV '%s' is a CNAME (illegal)",
                                     ownerbuf, namebuf);
                return ((level == ISC_LOG_WARNING) ? ISC_TRUE : ISC_FALSE);
        }

        if (result == DNS_R_DNAME) {
                if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_WARNSRVCNAME) ||
                    DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IGNORESRVCNAME))
                        level = ISC_LOG_WARNING;
                if (!DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IGNORESRVCNAME)) {
                        dns_name_format(foundname, altbuf, sizeof altbuf);
                        dns_zone_log(zone, level, "%s/SRV '%s' is below a "
                                     "DNAME '%s' (illegal)", ownerbuf, namebuf,
                                     altbuf);
                }
                return ((level == ISC_LOG_WARNING) ? ISC_TRUE : ISC_FALSE);
        }

        if (zone->checksrv != NULL && result == DNS_R_DELEGATION)
                return ((zone->checksrv)(zone, name, owner));

        return (ISC_TRUE);
}

static isc_boolean_t
zone_check_glue(dns_zone_t *zone, dns_db_t *db, dns_name_t *name,
                dns_name_t *owner)
{
        isc_boolean_t answer = ISC_TRUE;
        isc_result_t result, tresult;
        char ownerbuf[DNS_NAME_FORMATSIZE];
        char namebuf[DNS_NAME_FORMATSIZE];
        char altbuf[DNS_NAME_FORMATSIZE];
        dns_fixedname_t fixed;
        dns_name_t *foundname;
        dns_rdataset_t a;
        dns_rdataset_t aaaa;
        int level;

        /*
         * Outside of zone.
         */
        if (!dns_name_issubdomain(name, &zone->origin)) {
                if (zone->checkns != NULL)
                        return ((zone->checkns)(zone, name, owner, NULL, NULL));
                return (ISC_TRUE);
        }

        if (zone->type == dns_zone_master)
                level = ISC_LOG_ERROR;
        else
                level = ISC_LOG_WARNING;

        dns_fixedname_init(&fixed);
        foundname = dns_fixedname_name(&fixed);
        dns_rdataset_init(&a);
        dns_rdataset_init(&aaaa);

        result = dns_db_find(db, name, NULL, dns_rdatatype_a,
                             DNS_DBFIND_GLUEOK, 0, NULL,
                             foundname, &a, NULL);

        if (result == ISC_R_SUCCESS) {
                dns_rdataset_disassociate(&a);
                return (ISC_TRUE);
        } else if (result == DNS_R_DELEGATION)
                dns_rdataset_disassociate(&a);

        if (result == DNS_R_NXRRSET || result == DNS_R_DELEGATION ||
            result == DNS_R_GLUE) {
                tresult = dns_db_find(db, name, NULL, dns_rdatatype_aaaa,
                                     DNS_DBFIND_GLUEOK, 0, NULL,
                                     foundname, &aaaa, NULL);
                if (tresult == ISC_R_SUCCESS) {
                        dns_rdataset_disassociate(&aaaa);
                        return (ISC_TRUE);
                }
                if (tresult == DNS_R_DELEGATION)
                        dns_rdataset_disassociate(&aaaa);
                if (result == DNS_R_GLUE || tresult == DNS_R_GLUE) {
                        /*
                         * Check glue against child zone.
                         */
                        if (zone->checkns != NULL)
                                answer = (zone->checkns)(zone, name, owner,
                                                         &a, &aaaa);
                        if (dns_rdataset_isassociated(&a))
                                dns_rdataset_disassociate(&a);
                        if (dns_rdataset_isassociated(&aaaa))
                                dns_rdataset_disassociate(&aaaa);
                        return (answer);
                }
        }

        dns_name_format(owner, ownerbuf, sizeof ownerbuf);
        dns_name_format(name, namebuf, sizeof namebuf);
        if (result == DNS_R_NXRRSET || result == DNS_R_NXDOMAIN ||
            result == DNS_R_EMPTYNAME || result == DNS_R_DELEGATION) {
                const char *what;
                isc_boolean_t required = ISC_FALSE;
                if (dns_name_issubdomain(name, owner)) {
                        what = "REQUIRED GLUE ";
                        required = ISC_TRUE;
                 } else if (result == DNS_R_DELEGATION)
                        what = "SIBLING GLUE ";
                else
                        what = "";

                if (result != DNS_R_DELEGATION || required ||
                    DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKSIBLING)) {
                        dns_zone_log(zone, level, "%s/NS '%s' has no %s"
                                     "address records (A or AAAA)",
                                     ownerbuf, namebuf, what);
                        /*
                         * Log missing address record.
                         */
                        if (result == DNS_R_DELEGATION && zone->checkns != NULL)
                                (void)(zone->checkns)(zone, name, owner,
                                                      &a, &aaaa);
                        /* XXX950 make fatal for 9.5.0. */
                        /* answer = ISC_FALSE; */
                }
        } else if (result == DNS_R_CNAME) {
                dns_zone_log(zone, level, "%s/NS '%s' is a CNAME (illegal)",
                             ownerbuf, namebuf);
                /* XXX950 make fatal for 9.5.0. */
                /* answer = ISC_FALSE; */
        } else if (result == DNS_R_DNAME) {
                dns_name_format(foundname, altbuf, sizeof altbuf);
                dns_zone_log(zone, level,
                             "%s/NS '%s' is below a DNAME '%s' (illegal)",
                             ownerbuf, namebuf, altbuf);
                /* XXX950 make fatal for 9.5.0. */
                /* answer = ISC_FALSE; */
        }

        if (dns_rdataset_isassociated(&a))
                dns_rdataset_disassociate(&a);
        if (dns_rdataset_isassociated(&aaaa))
                dns_rdataset_disassociate(&aaaa);
        return (answer);
}

static isc_boolean_t
zone_rrset_check_dup(dns_zone_t *zone, dns_name_t *owner,
                     dns_rdataset_t *rdataset)
{
        dns_rdataset_t tmprdataset;
        isc_result_t result;
        isc_boolean_t answer = ISC_TRUE;
        isc_boolean_t format = ISC_TRUE;
        int level = ISC_LOG_WARNING;
        char ownerbuf[DNS_NAME_FORMATSIZE];
        char typebuf[DNS_RDATATYPE_FORMATSIZE];
        unsigned int count1 = 0;

        if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKDUPRRFAIL))
                level = ISC_LOG_ERROR;

        dns_rdataset_init(&tmprdataset);
        for (result = dns_rdataset_first(rdataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(rdataset)) {
                dns_rdata_t rdata1 = DNS_RDATA_INIT;
                unsigned int count2 = 0;

                count1++;
                dns_rdataset_current(rdataset, &rdata1);
                dns_rdataset_clone(rdataset, &tmprdataset);
                for (result = dns_rdataset_first(&tmprdataset);
                     result == ISC_R_SUCCESS;
                     result = dns_rdataset_next(&tmprdataset)) {
                        dns_rdata_t rdata2 = DNS_RDATA_INIT;
                        count2++;
                        if (count1 >= count2)
                                continue;
                        dns_rdataset_current(&tmprdataset, &rdata2);
                        if (dns_rdata_casecompare(&rdata1, &rdata2) == 0) {
                                if (format) {
                                        dns_name_format(owner, ownerbuf,
                                                        sizeof ownerbuf);
                                        dns_rdatatype_format(rdata1.type,
                                                             typebuf,
                                                             sizeof(typebuf));
                                        format = ISC_FALSE;
                                }
                                dns_zone_log(zone, level, "%s/%s has "
                                             "semantically identical records",
                                             ownerbuf, typebuf);
                                if (level == ISC_LOG_ERROR)
                                        answer = ISC_FALSE;
                                break;
                        }
                }
                dns_rdataset_disassociate(&tmprdataset);
                if (!format)
                        break;
        }
        return (answer);
}

static isc_boolean_t
zone_check_dup(dns_zone_t *zone, dns_db_t *db) {
        dns_dbiterator_t *dbiterator = NULL;
        dns_dbnode_t *node = NULL;
        dns_fixedname_t fixed;
        dns_name_t *name;
        dns_rdataset_t rdataset;
        dns_rdatasetiter_t *rdsit = NULL;
        isc_boolean_t ok = ISC_TRUE;
        isc_result_t result;

        dns_fixedname_init(&fixed);
        name = dns_fixedname_name(&fixed);
        dns_rdataset_init(&rdataset);

        result = dns_db_createiterator(db, 0, &dbiterator);
        if (result != ISC_R_SUCCESS)
                return (ISC_TRUE);

        for (result = dns_dbiterator_first(dbiterator);
             result == ISC_R_SUCCESS;
             result = dns_dbiterator_next(dbiterator)) {
                result = dns_dbiterator_current(dbiterator, &node, name);
                if (result != ISC_R_SUCCESS)
                        continue;

                result = dns_db_allrdatasets(db, node, NULL, 0, &rdsit);
                if (result != ISC_R_SUCCESS)
                        continue;

                for (result = dns_rdatasetiter_first(rdsit);
                     result == ISC_R_SUCCESS;
                     result = dns_rdatasetiter_next(rdsit)) {
                        dns_rdatasetiter_current(rdsit, &rdataset);
                        if (!zone_rrset_check_dup(zone, name, &rdataset))
                                ok = ISC_FALSE;
                        dns_rdataset_disassociate(&rdataset);
                }
                dns_rdatasetiter_destroy(&rdsit);
                dns_db_detachnode(db, &node);
        }

        if (node != NULL)
                dns_db_detachnode(db, &node);
        dns_dbiterator_destroy(&dbiterator);

        return (ok);
}

static isc_boolean_t
integrity_checks(dns_zone_t *zone, dns_db_t *db) {
        dns_dbiterator_t *dbiterator = NULL;
        dns_dbnode_t *node = NULL;
        dns_rdataset_t rdataset;
        dns_fixedname_t fixed;
        dns_fixedname_t fixedbottom;
        dns_rdata_mx_t mx;
        dns_rdata_ns_t ns;
        dns_rdata_in_srv_t srv;
        dns_rdata_t rdata;
        dns_name_t *name;
        dns_name_t *bottom;
        isc_result_t result;
        isc_boolean_t ok = ISC_TRUE;

        dns_fixedname_init(&fixed);
        name = dns_fixedname_name(&fixed);
        dns_fixedname_init(&fixedbottom);
        bottom = dns_fixedname_name(&fixedbottom);
        dns_rdataset_init(&rdataset);
        dns_rdata_init(&rdata);

        result = dns_db_createiterator(db, 0, &dbiterator);
        if (result != ISC_R_SUCCESS)
                return (ISC_TRUE);

        result = dns_dbiterator_first(dbiterator);
        while (result == ISC_R_SUCCESS) {
                result = dns_dbiterator_current(dbiterator, &node, name);
                if (result != ISC_R_SUCCESS)
                        goto cleanup;

                /*
                 * Is this name visible in the zone?
                 */
                if (!dns_name_issubdomain(name, &zone->origin) ||
                    (dns_name_countlabels(bottom) > 0 &&
                     dns_name_issubdomain(name, bottom)))
                        goto next;

                /*
                 * Don't check the NS records at the origin.
                 */
                if (dns_name_equal(name, &zone->origin))
                        goto checkmx;

                result = dns_db_findrdataset(db, node, NULL, dns_rdatatype_ns,
                                             0, 0, &rdataset, NULL);
                if (result != ISC_R_SUCCESS)
                        goto checkmx;
                /*
                 * Remember bottom of zone.
                 */
                dns_name_copy(name, bottom, NULL);

                result = dns_rdataset_first(&rdataset);
                while (result == ISC_R_SUCCESS) {
                        dns_rdataset_current(&rdataset, &rdata);
                        result = dns_rdata_tostruct(&rdata, &ns, NULL);
                        RUNTIME_CHECK(result == ISC_R_SUCCESS);
                        if (!zone_check_glue(zone, db, &ns.name, name))
                                ok = ISC_FALSE;
                        dns_rdata_reset(&rdata);
                        result = dns_rdataset_next(&rdataset);
                }
                dns_rdataset_disassociate(&rdataset);
                goto next;

 checkmx:
                result = dns_db_findrdataset(db, node, NULL, dns_rdatatype_mx,
                                             0, 0, &rdataset, NULL);
                if (result != ISC_R_SUCCESS)
                        goto checksrv;
                result = dns_rdataset_first(&rdataset);
                while (result == ISC_R_SUCCESS) {
                        dns_rdataset_current(&rdataset, &rdata);
                        result = dns_rdata_tostruct(&rdata, &mx, NULL);
                        RUNTIME_CHECK(result == ISC_R_SUCCESS);
                        if (!zone_check_mx(zone, db, &mx.mx, name))
                                ok = ISC_FALSE;
                        dns_rdata_reset(&rdata);
                        result = dns_rdataset_next(&rdataset);
                }
                dns_rdataset_disassociate(&rdataset);

 checksrv:
                if (zone->rdclass != dns_rdataclass_in)
                        goto next;
                result = dns_db_findrdataset(db, node, NULL, dns_rdatatype_srv,
                                             0, 0, &rdataset, NULL);
                if (result != ISC_R_SUCCESS)
                        goto next;
                result = dns_rdataset_first(&rdataset);
                while (result == ISC_R_SUCCESS) {
                        dns_rdataset_current(&rdataset, &rdata);
                        result = dns_rdata_tostruct(&rdata, &srv, NULL);
                        RUNTIME_CHECK(result == ISC_R_SUCCESS);
                        if (!zone_check_srv(zone, db, &srv.target, name))
                                ok = ISC_FALSE;
                        dns_rdata_reset(&rdata);
                        result = dns_rdataset_next(&rdataset);
                }
                dns_rdataset_disassociate(&rdataset);

 next:
                dns_db_detachnode(db, &node);
                result = dns_dbiterator_next(dbiterator);
        }

 cleanup:
        if (node != NULL)
                dns_db_detachnode(db, &node);
        dns_dbiterator_destroy(&dbiterator);

        return (ok);
}

/*
 * OpenSSL verification of RSA keys with exponent 3 is known to be
 * broken prior OpenSSL 0.9.8c/0.9.7k.  Look for such keys and warn
 * if they are in use.
 */
static void
zone_check_dnskeys(dns_zone_t *zone, dns_db_t *db) {
        dns_dbnode_t *node = NULL;
        dns_dbversion_t *version = NULL;
        dns_rdata_dnskey_t dnskey;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_rdataset_t rdataset;
        isc_result_t result;
        isc_boolean_t logit, foundrsa = ISC_FALSE, foundmd5 = ISC_FALSE;
        const char *algorithm;

        result = dns_db_findnode(db, &zone->origin, ISC_FALSE, &node);
        if (result != ISC_R_SUCCESS)
                goto cleanup;

        dns_db_currentversion(db, &version);
        dns_rdataset_init(&rdataset);
        result = dns_db_findrdataset(db, node, version, dns_rdatatype_dnskey,
                                     dns_rdatatype_none, 0, &rdataset, NULL);
        if (result != ISC_R_SUCCESS)
                goto cleanup;

        for (result = dns_rdataset_first(&rdataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(&rdataset))
        {
                dns_rdataset_current(&rdataset, &rdata);
                result = dns_rdata_tostruct(&rdata, &dnskey, NULL);
                INSIST(result == ISC_R_SUCCESS);

                if ((dnskey.algorithm == DST_ALG_RSASHA1 ||
                     dnskey.algorithm == DST_ALG_RSAMD5) &&
                     dnskey.datalen > 1 && dnskey.data[0] == 1 &&
                     dnskey.data[1] == 3)
                {
                        if (dnskey.algorithm == DST_ALG_RSASHA1) {
                                logit = !foundrsa;
                                foundrsa = ISC_TRUE;
                                algorithm = "RSASHA1";
                        } else {
                                logit = !foundmd5;
                                foundmd5 = ISC_TRUE;
                                algorithm = "RSAMD5";
                        }
                        if (logit)
                                dns_zone_log(zone, ISC_LOG_WARNING,
                                             "weak %s (%u) key found "
                                             "(exponent=3)", algorithm,
                                             dnskey.algorithm);
                        if (foundrsa && foundmd5)
                                break;
                }
                dns_rdata_reset(&rdata);
        }
        dns_rdataset_disassociate(&rdataset);

 cleanup:
        if (node != NULL)
                dns_db_detachnode(db, &node);
        if (version != NULL)
                dns_db_closeversion(db, &version, ISC_FALSE);
}

static void
resume_signingwithkey(dns_zone_t *zone) {
        dns_dbnode_t *node = NULL;
        dns_dbversion_t *version = NULL;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_rdataset_t rdataset;
        isc_result_t result;

        result = dns_db_findnode(zone->db, &zone->origin, ISC_FALSE, &node);
        if (result != ISC_R_SUCCESS)
                goto cleanup;

        dns_db_currentversion(zone->db, &version);
        dns_rdataset_init(&rdataset);
        result = dns_db_findrdataset(zone->db, node, version,
                                     zone->privatetype,
                                     dns_rdatatype_none, 0,
                                     &rdataset, NULL);
        if (result != ISC_R_SUCCESS) {
                INSIST(!dns_rdataset_isassociated(&rdataset));
                goto cleanup;
        }

        for (result = dns_rdataset_first(&rdataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(&rdataset))
        {
                dns_rdataset_current(&rdataset, &rdata);
                if (rdata.length != 5 ||
                    rdata.data[0] == 0 || rdata.data[4] != 0) {
                        dns_rdata_reset(&rdata);
                        continue;
                }

                result = zone_signwithkey(zone, rdata.data[0],
                                          (rdata.data[1] << 8) | rdata.data[2],
                                          ISC_TF(rdata.data[3]));
                if (result != ISC_R_SUCCESS) {
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "zone_signwithkey failed: %s",
                                     dns_result_totext(result));
                }
                dns_rdata_reset(&rdata);
        }
        dns_rdataset_disassociate(&rdataset);

 cleanup:
        if (node != NULL)
                dns_db_detachnode(zone->db, &node);
        if (version != NULL)
                dns_db_closeversion(zone->db, &version, ISC_FALSE);
}

static isc_result_t
zone_addnsec3chain(dns_zone_t *zone, dns_rdata_nsec3param_t *nsec3param) {
        dns_nsec3chain_t *nsec3chain, *current;
        isc_result_t result;
        isc_time_t now;
        unsigned int options = 0;
        char saltbuf[255*2+1];
        char flags[sizeof("REMOVE|CREATE|NONSEC|OPTOUT")];
        int i;

        nsec3chain = isc_mem_get(zone->mctx, sizeof *nsec3chain);
        if (nsec3chain == NULL)
                return (ISC_R_NOMEMORY);

        nsec3chain->magic = 0;
        nsec3chain->done = ISC_FALSE;
        nsec3chain->db = NULL;
        nsec3chain->dbiterator = NULL;
        nsec3chain->nsec3param.common.rdclass = nsec3param->common.rdclass;
        nsec3chain->nsec3param.common.rdtype = nsec3param->common.rdtype;
        nsec3chain->nsec3param.hash = nsec3param->hash;
        nsec3chain->nsec3param.iterations = nsec3param->iterations;
        nsec3chain->nsec3param.flags = nsec3param->flags;
        nsec3chain->nsec3param.salt_length = nsec3param->salt_length;
        memcpy(nsec3chain->salt, nsec3param->salt, nsec3param->salt_length);
        nsec3chain->nsec3param.salt = nsec3chain->salt;
        nsec3chain->seen_nsec = ISC_FALSE;
        nsec3chain->delete_nsec = ISC_FALSE;
        nsec3chain->save_delete_nsec = ISC_FALSE;

        if (nsec3param->flags == 0)
                strlcpy(flags, "NONE", sizeof(flags));
        else {
                flags[0] = '\0';
                if (nsec3param->flags & DNS_NSEC3FLAG_REMOVE)
                        strlcat(flags, "REMOVE", sizeof(flags));
                if (nsec3param->flags & DNS_NSEC3FLAG_CREATE) {
                        if (flags[0] == '\0')
                                strlcpy(flags, "CREATE", sizeof(flags));
                        else
                                strlcat(flags, "|CREATE", sizeof(flags));
                }
                if (nsec3param->flags & DNS_NSEC3FLAG_NONSEC) {
                        if (flags[0] == '\0')
                                strlcpy(flags, "NONSEC", sizeof(flags));
                        else
                                strlcat(flags, "|NONSEC", sizeof(flags));
                }
                if (nsec3param->flags & DNS_NSEC3FLAG_OPTOUT) {
                        if (flags[0] == '\0')
                                strlcpy(flags, "OPTOUT", sizeof(flags));
                        else
                                strlcat(flags, "|OPTOUT", sizeof(flags));
                }
        }
        if (nsec3param->salt_length == 0)
                strlcpy(saltbuf, "-", sizeof(saltbuf));
        else
                for (i = 0; i < nsec3param->salt_length; i++)
                        sprintf(&saltbuf[i*2], "%02X", nsec3chain->salt[i]);
        dns_zone_log(zone, ISC_LOG_INFO,
                     "zone_addnsec3chain(%u,%s,%u,%s)",
                      nsec3param->hash, flags, nsec3param->iterations,
                      saltbuf);
        for (current = ISC_LIST_HEAD(zone->nsec3chain);
             current != NULL;
             current = ISC_LIST_NEXT(current, link)) {
                if (current->db == zone->db &&
                    current->nsec3param.hash == nsec3param->hash &&
                    current->nsec3param.iterations == nsec3param->iterations &&
                    current->nsec3param.salt_length == nsec3param->salt_length
                    && !memcmp(current->nsec3param.salt, nsec3param->salt,
                               nsec3param->salt_length))
                        current->done = ISC_TRUE;
        }

        if (zone->db != NULL) {
                dns_db_attach(zone->db, &nsec3chain->db);
                if ((nsec3chain->nsec3param.flags & DNS_NSEC3FLAG_CREATE) != 0)
                        options = DNS_DB_NONSEC3;
                result = dns_db_createiterator(nsec3chain->db, options,
                                               &nsec3chain->dbiterator);
                if (result == ISC_R_SUCCESS)
                        dns_dbiterator_first(nsec3chain->dbiterator);
                if (result == ISC_R_SUCCESS) {
                        dns_dbiterator_pause(nsec3chain->dbiterator);
                        ISC_LIST_INITANDAPPEND(zone->nsec3chain,
                                               nsec3chain, link);
                        nsec3chain = NULL;
                        if (isc_time_isepoch(&zone->nsec3chaintime)) {
                                TIME_NOW(&now);
                                zone->nsec3chaintime = now;
                                if (zone->task != NULL)
                                        zone_settimer(zone, &now);
                        }
                }
        } else
                result = ISC_R_NOTFOUND;

        if (nsec3chain != NULL) {
                if (nsec3chain->db != NULL)
                        dns_db_detach(&nsec3chain->db);
                if (nsec3chain->dbiterator != NULL)
                        dns_dbiterator_destroy(&nsec3chain->dbiterator);
                isc_mem_put(zone->mctx, nsec3chain, sizeof *nsec3chain);
        }
        return (result);
}

static void
resume_addnsec3chain(dns_zone_t *zone) {
        dns_dbnode_t *node = NULL;
        dns_dbversion_t *version = NULL;
        dns_rdataset_t rdataset;
        isc_result_t result;
        dns_rdata_nsec3param_t nsec3param;

        if (zone->privatetype == 0)
                return;

        result = dns_db_findnode(zone->db, &zone->origin, ISC_FALSE, &node);
        if (result != ISC_R_SUCCESS)
                goto cleanup;

        dns_db_currentversion(zone->db, &version);
        dns_rdataset_init(&rdataset);
        result = dns_db_findrdataset(zone->db, node, version,
                                     zone->privatetype, dns_rdatatype_none,
                                     0, &rdataset, NULL);
        if (result != ISC_R_SUCCESS) {
                INSIST(!dns_rdataset_isassociated(&rdataset));
                goto cleanup;
        }

        for (result = dns_rdataset_first(&rdataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(&rdataset))
        {
                unsigned char buf[DNS_NSEC3PARAM_BUFFERSIZE];
                dns_rdata_t rdata = DNS_RDATA_INIT;
                dns_rdata_t private = DNS_RDATA_INIT;

                dns_rdataset_current(&rdataset, &private);
                if (!dns_nsec3param_fromprivate(&private, &rdata, buf,
                                                sizeof(buf)))
                        continue;
                result = dns_rdata_tostruct(&rdata, &nsec3param, NULL);
                RUNTIME_CHECK(result == ISC_R_SUCCESS);
                if ((nsec3param.flags & DNS_NSEC3FLAG_CREATE) != 0 ||
                    (nsec3param.flags & DNS_NSEC3FLAG_REMOVE) != 0) {
                        result = zone_addnsec3chain(zone, &nsec3param);
                        if (result != ISC_R_SUCCESS) {
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "zone_addnsec3chain failed: %s",
                                             dns_result_totext(result));
                        }
                }
        }
        dns_rdataset_disassociate(&rdataset);
 cleanup:
        if (node != NULL)
                dns_db_detachnode(zone->db, &node);
        if (version != NULL)
                dns_db_closeversion(zone->db, &version, ISC_FALSE);
}

static void
set_resigntime(dns_zone_t *zone) {
        dns_rdataset_t rdataset;
        dns_fixedname_t fixed;
        unsigned int resign;
        isc_result_t result;
        isc_uint32_t nanosecs;

        dns_rdataset_init(&rdataset);
        dns_fixedname_init(&fixed);
        result = dns_db_getsigningtime(zone->db, &rdataset,
                                       dns_fixedname_name(&fixed));
        if (result != ISC_R_SUCCESS) {
                isc_time_settoepoch(&zone->resigntime);
                return;
        }
        resign = rdataset.resign;
        dns_rdataset_disassociate(&rdataset);
        isc_random_get(&nanosecs);
        nanosecs %= 1000000000;
        isc_time_set(&zone->resigntime, resign, nanosecs);
}

static isc_result_t
check_nsec3param(dns_zone_t *zone, dns_db_t *db) {
        dns_dbnode_t *node = NULL;
        dns_rdataset_t rdataset;
        dns_dbversion_t *version = NULL;
        dns_rdata_nsec3param_t nsec3param;
        isc_boolean_t ok = ISC_FALSE;
        isc_result_t result;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        isc_boolean_t dynamic = (zone->type == dns_zone_master) ?
                                zone_isdynamic(zone) : ISC_FALSE;

        dns_rdataset_init(&rdataset);
        result = dns_db_findnode(db, &zone->origin, ISC_FALSE, &node);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "nsec3param lookup failure: %s",
                             dns_result_totext(result));
                return (result);
        }
        dns_db_currentversion(db, &version);

        result = dns_db_findrdataset(db, node, version,
                                     dns_rdatatype_nsec3param,
                                     dns_rdatatype_none, 0, &rdataset, NULL);
        if (result == ISC_R_NOTFOUND) {
                INSIST(!dns_rdataset_isassociated(&rdataset));
                result = ISC_R_SUCCESS;
                goto cleanup;
        }
        if (result != ISC_R_SUCCESS) {
                INSIST(!dns_rdataset_isassociated(&rdataset));
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "nsec3param lookup failure: %s",
                             dns_result_totext(result));
                goto cleanup;
        }

        /*
         * For dynamic zones we must support every algorithm so we can
         * regenerate all the NSEC3 chains.
         * For non-dynamic zones we only need to find a supported algorithm.
         */
        for (result = dns_rdataset_first(&rdataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(&rdataset))
        {
                dns_rdataset_current(&rdataset, &rdata);
                result = dns_rdata_tostruct(&rdata, &nsec3param, NULL);
                dns_rdata_reset(&rdata);
                INSIST(result == ISC_R_SUCCESS);
                if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_NSEC3TESTZONE) &&
                    nsec3param.hash == DNS_NSEC3_UNKNOWNALG && !dynamic)
                {
                        dns_zone_log(zone, ISC_LOG_WARNING,
                             "nsec3 test \"unknown\" hash algorithm found: %u",
                                     nsec3param.hash);
                        ok = ISC_TRUE;
                } else if (!dns_nsec3_supportedhash(nsec3param.hash)) {
                        if (dynamic) {
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "unsupported nsec3 hash algorithm"
                                             " in dynamic zone: %u",
                                             nsec3param.hash);
                                result = DNS_R_BADZONE;
                                /* Stop second error message. */
                                ok = ISC_TRUE;
                                break;
                        } else
                                dns_zone_log(zone, ISC_LOG_WARNING,
                                     "unsupported nsec3 hash algorithm: %u",
                                             nsec3param.hash);
                } else
                        ok = ISC_TRUE;
        }
        if (result == ISC_R_NOMORE)
                result = ISC_R_SUCCESS;

        if (!ok) {
                result = DNS_R_BADZONE;
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "no supported nsec3 hash algorithm");
        }

 cleanup:
        if (dns_rdataset_isassociated(&rdataset))
                dns_rdataset_disassociate(&rdataset);
        dns_db_closeversion(db, &version, ISC_FALSE);
        dns_db_detachnode(db, &node);
        return (result);
}

/*
 * Set the timer for refreshing the key zone to the soonest future time
 * of the set (current timer, keydata->refresh, keydata->addhd,
 * keydata->removehd).
 */
static void
set_refreshkeytimer(dns_zone_t *zone, dns_rdata_keydata_t *key,
                    isc_stdtime_t now)
{
        const char me[] = "set_refreshkeytimer";
        isc_stdtime_t then;
        isc_time_t timenow, timethen;
        char timebuf[80];

        ENTER;
        then = key->refresh;
        if (key->addhd > now && key->addhd < then)
                then = key->addhd;
        if (key->removehd > now && key->removehd < then)
                then = key->removehd;

        TIME_NOW(&timenow);
        if (then > now)
                DNS_ZONE_TIME_ADD(&timenow, then - now, &timethen);
        else
                timethen = timenow;
        if (isc_time_compare(&zone->refreshkeytime, &timenow) < 0 ||
            isc_time_compare(&timethen, &zone->refreshkeytime) < 0)
                zone->refreshkeytime = timethen;

        isc_time_formattimestamp(&zone->refreshkeytime, timebuf, 80);
        dns_zone_log(zone, ISC_LOG_DEBUG(1), "next key refresh: %s", timebuf);
        zone_settimer(zone, &timenow);
}

/*
 * Convert key(s) linked from 'keynode' to KEYDATA and add to the key zone.
 * If the key zone is changed, set '*changed' to ISC_TRUE.
 */
static isc_result_t
create_keydata(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *ver,
               dns_diff_t *diff, dns_keytable_t *keytable,
               dns_keynode_t **keynodep, isc_boolean_t *changed)
{
        const char me[] = "create_keydata";
        isc_result_t result = ISC_R_SUCCESS;
        isc_buffer_t keyb, dstb;
        unsigned char key_buf[4096], dst_buf[DST_KEY_MAXSIZE];
        dns_rdata_keydata_t keydata;
        dns_rdata_dnskey_t dnskey;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_keynode_t *keynode;
        isc_stdtime_t now;
        isc_region_t r;
        dst_key_t *key;

        REQUIRE(keynodep != NULL);
        keynode = *keynodep;

        ENTER;
        isc_stdtime_get(&now);

        /* Loop in case there's more than one key. */
        while (result == ISC_R_SUCCESS) {
                dns_keynode_t *nextnode = NULL;

                key = dns_keynode_key(keynode);
                if (key == NULL)
                        goto skip;

                isc_buffer_init(&dstb, dst_buf, sizeof(dst_buf));
                CHECK(dst_key_todns(key, &dstb));

                /* Convert DST key to DNSKEY. */
                dns_rdata_reset(&rdata);
                isc_buffer_usedregion(&dstb, &r);
                dns_rdata_fromregion(&rdata, dst_key_class(key),
                                     dns_rdatatype_dnskey, &r);

                /* DSTKEY to KEYDATA. */
                CHECK(dns_rdata_tostruct(&rdata, &dnskey, NULL));
                CHECK(dns_keydata_fromdnskey(&keydata, &dnskey, now, 0, 0,
                                             NULL));

                /* KEYDATA to rdata. */
                dns_rdata_reset(&rdata);
                isc_buffer_init(&keyb, key_buf, sizeof(key_buf));
                CHECK(dns_rdata_fromstruct(&rdata,
                                           zone->rdclass, dns_rdatatype_keydata,
                                           &keydata, &keyb));

                /* Add rdata to zone. */
                CHECK(update_one_rr(db, ver, diff, DNS_DIFFOP_ADD,
                                    dst_key_name(key), 0, &rdata));
                *changed = ISC_TRUE;

 skip:
                result = dns_keytable_nextkeynode(keytable, keynode, &nextnode);
                if (result != ISC_R_NOTFOUND) {
                        dns_keytable_detachkeynode(keytable, &keynode);
                        keynode = nextnode;
                }
        }

        /* Refresh new keys from the zone apex as soon as possible. */
        if (*changed)
                set_refreshkeytimer(zone, &keydata, now);

        if (keynode != NULL)
                dns_keytable_detachkeynode(keytable, &keynode);
        *keynodep = NULL;

        return (ISC_R_SUCCESS);

  failure:
        return (result);
}

/*
 * Remove from the key zone all the KEYDATA records found in rdataset.
 */
static isc_result_t
delete_keydata(dns_db_t *db, dns_dbversion_t *ver, dns_diff_t *diff,
               dns_name_t *name, dns_rdataset_t *rdataset)
{
        dns_rdata_t rdata = DNS_RDATA_INIT;
        isc_result_t result, uresult;

        for (result = dns_rdataset_first(rdataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(rdataset)) {
                dns_rdata_reset(&rdata);
                dns_rdataset_current(rdataset, &rdata);
                uresult = update_one_rr(db, ver, diff, DNS_DIFFOP_DEL,
                                        name, 0, &rdata);
                if (uresult != ISC_R_SUCCESS)
                        return (uresult);
        }
        if (result == ISC_R_NOMORE)
                result = ISC_R_SUCCESS;
        return (result);
}

/*
 * Compute the DNSSEC key ID for a DNSKEY record.
 */
static isc_result_t
compute_tag(dns_name_t *name, dns_rdata_dnskey_t *dnskey, isc_mem_t *mctx,
            dns_keytag_t *tag)
{
        isc_result_t result;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        unsigned char data[4096];
        isc_buffer_t buffer;
        dst_key_t *dstkey = NULL;

        isc_buffer_init(&buffer, data, sizeof(data));
        dns_rdata_fromstruct(&rdata, dnskey->common.rdclass,
                             dns_rdatatype_dnskey, dnskey, &buffer);

        result = dns_dnssec_keyfromrdata(name, &rdata, mctx, &dstkey);
        if (result == ISC_R_SUCCESS)
                *tag = dst_key_id(dstkey);
        dst_key_free(&dstkey);

        return (result);
}

/*
 * Add key to the security roots.
 */
static void
trust_key(dns_zone_t *zone, dns_name_t *keyname,
          dns_rdata_dnskey_t *dnskey, isc_mem_t *mctx) {
        isc_result_t result;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        unsigned char data[4096];
        isc_buffer_t buffer;
        dns_keytable_t *sr = NULL;
        dst_key_t *dstkey = NULL;

        /* Convert dnskey to DST key. */
        isc_buffer_init(&buffer, data, sizeof(data));
        dns_rdata_fromstruct(&rdata, dnskey->common.rdclass,
                             dns_rdatatype_dnskey, dnskey, &buffer);

        result = dns_view_getsecroots(zone->view, &sr);
        if (result != ISC_R_SUCCESS)
                goto failure;

        CHECK(dns_dnssec_keyfromrdata(keyname, &rdata, mctx, &dstkey));
        CHECK(dns_keytable_add(sr, ISC_TRUE, &dstkey));
        dns_keytable_detach(&sr);

  failure:
        if (dstkey != NULL)
                dst_key_free(&dstkey);
        if (sr != NULL)
                dns_keytable_detach(&sr);
        return;
}

/*
 * Add a null key to the security roots for so that all queries
 * to the zone will fail.
 */
static void
fail_secure(dns_zone_t *zone, dns_name_t *keyname) {
        isc_result_t result;
        dns_keytable_t *sr = NULL;

        result = dns_view_getsecroots(zone->view, &sr);
        if (result == ISC_R_SUCCESS) {
                dns_keytable_marksecure(sr, keyname);
                dns_keytable_detach(&sr);
        }
}

/*
 * Scan a set of KEYDATA records from the key zone.  The ones that are
 * valid (i.e., the add holddown timer has expired) become trusted keys.
 */
static void
load_secroots(dns_zone_t *zone, dns_name_t *name, dns_rdataset_t *rdataset) {
        isc_result_t result;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_rdata_keydata_t keydata;
        dns_rdata_dnskey_t dnskey;
        isc_mem_t *mctx = zone->mctx;
        int trusted = 0, revoked = 0, pending = 0;
        isc_stdtime_t now;
        dns_keytable_t *sr = NULL;

        isc_stdtime_get(&now);

        result = dns_view_getsecroots(zone->view, &sr);
        if (result == ISC_R_SUCCESS) {
                dns_keytable_delete(sr, name);
                dns_keytable_detach(&sr);
        }

        /* Now insert all the accepted trust anchors from this keydata set. */
        for (result = dns_rdataset_first(rdataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(rdataset)) {
                dns_rdata_reset(&rdata);
                dns_rdataset_current(rdataset, &rdata);

                /* Convert rdata to keydata. */
                dns_rdata_tostruct(&rdata, &keydata, NULL);

                /* Set the key refresh timer. */
                set_refreshkeytimer(zone, &keydata, now);

                /* If the removal timer is nonzero, this key was revoked. */
                if (keydata.removehd != 0) {
                        revoked++;
                        continue;
                }

                /*
                 * If the add timer is still pending, this key is not
                 * trusted yet.
                 */
                if (now < keydata.addhd) {
                        pending++;
                        continue;
                }

                /* Convert keydata to dnskey. */
                dns_keydata_todnskey(&keydata, &dnskey, NULL);

                /* Add to keytables. */
                trusted++;
                trust_key(zone, name, &dnskey, mctx);
        }

        if (trusted == 0 && pending != 0) {
                char namebuf[DNS_NAME_FORMATSIZE];
                dns_name_format(name, namebuf, sizeof namebuf);
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "No valid trust anchors for '%s'!", namebuf);
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "%d key(s) revoked, %d still pending",
                             revoked, pending);
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "All queries to '%s' will fail", namebuf);
                fail_secure(zone, name);
        }
}

static isc_result_t
do_one_tuple(dns_difftuple_t **tuple, dns_db_t *db, dns_dbversion_t *ver,
             dns_diff_t *diff)
{
        dns_diff_t temp_diff;
        isc_result_t result;

        /*
         * Create a singleton diff.
         */
        dns_diff_init(diff->mctx, &temp_diff);
        temp_diff.resign = diff->resign;
        ISC_LIST_APPEND(temp_diff.tuples, *tuple, link);

        /*
         * Apply it to the database.
         */
        result = dns_diff_apply(&temp_diff, db, ver);
        ISC_LIST_UNLINK(temp_diff.tuples, *tuple, link);
        if (result != ISC_R_SUCCESS) {
                dns_difftuple_free(tuple);
                return (result);
        }

        /*
         * Merge it into the current pending journal entry.
         */
        dns_diff_appendminimal(diff, tuple);

        /*
         * Do not clear temp_diff.
         */
        return (ISC_R_SUCCESS);
}

static isc_result_t
update_one_rr(dns_db_t *db, dns_dbversion_t *ver, dns_diff_t *diff,
              dns_diffop_t op, dns_name_t *name, dns_ttl_t ttl,
              dns_rdata_t *rdata)
{
        dns_difftuple_t *tuple = NULL;
        isc_result_t result;
        result = dns_difftuple_create(diff->mctx, op,
                                      name, ttl, rdata, &tuple);
        if (result != ISC_R_SUCCESS)
                return (result);
        return (do_one_tuple(&tuple, db, ver, diff));
}

static isc_result_t
increment_soa_serial(dns_db_t *db, dns_dbversion_t *ver,
                     dns_diff_t *diff, isc_mem_t *mctx) {
        dns_difftuple_t *deltuple = NULL;
        dns_difftuple_t *addtuple = NULL;
        isc_uint32_t serial;
        isc_result_t result;

        CHECK(dns_db_createsoatuple(db, ver, mctx, DNS_DIFFOP_DEL, &deltuple));
        CHECK(dns_difftuple_copy(deltuple, &addtuple));
        addtuple->op = DNS_DIFFOP_ADD;

        serial = dns_soa_getserial(&addtuple->rdata);

        /* RFC1982 */
        serial = (serial + 1) & 0xFFFFFFFF;
        if (serial == 0)
                serial = 1;

        dns_soa_setserial(serial, &addtuple->rdata);
        CHECK(do_one_tuple(&deltuple, db, ver, diff));
        CHECK(do_one_tuple(&addtuple, db, ver, diff));
        result = ISC_R_SUCCESS;

        failure:
        if (addtuple != NULL)
                dns_difftuple_free(&addtuple);
        if (deltuple != NULL)
                dns_difftuple_free(&deltuple);
        return (result);
}

/*
 * Write all transactions in 'diff' to the zone journal file.
 */
static isc_result_t
zone_journal(dns_zone_t *zone, dns_diff_t *diff, const char *caller) {
        const char me[] = "zone_journal";
        const char *journalfile;
        isc_result_t result = ISC_R_SUCCESS;
        dns_journal_t *journal = NULL;

        ENTER;
        journalfile = dns_zone_getjournal(zone);
        if (journalfile != NULL) {
                result = dns_journal_open(zone->mctx, journalfile,
                                          ISC_TRUE, &journal);
                if (result != ISC_R_SUCCESS) {
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "%s:dns_journal_open -> %s",
                                     caller, dns_result_totext(result));
                        return (result);
                }

                result = dns_journal_write_transaction(journal, diff);
                dns_journal_destroy(&journal);
                if (result != ISC_R_SUCCESS) {
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "%s:dns_journal_write_transaction -> %s",
                                     caller, dns_result_totext(result));
                        return (result);
                }
        }
        return (result);
}

/*
 * Create an SOA record for a newly-created zone
 */
static isc_result_t
add_soa(dns_zone_t *zone, dns_db_t *db) {
        isc_result_t result;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        unsigned char buf[DNS_SOA_BUFFERSIZE];
        dns_dbversion_t *ver = NULL;
        dns_diff_t diff;

        dns_zone_log(zone, ISC_LOG_DEBUG(1), "creating SOA");

        dns_diff_init(zone->mctx, &diff);
        result = dns_db_newversion(db, &ver);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "add_soa:dns_db_newversion -> %s",
                             dns_result_totext(result));
                goto failure;
        }

        /* Build SOA record */
        result = dns_soa_buildrdata(&zone->origin, dns_rootname, zone->rdclass,
                                    0, 0, 0, 0, 0, buf, &rdata);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "add_soa:dns_soa_buildrdata -> %s",
                             dns_result_totext(result));
                goto failure;
        }

        result = update_one_rr(db, ver, &diff, DNS_DIFFOP_ADD,
                               &zone->origin, 0, &rdata);

failure:
        dns_diff_clear(&diff);
        if (ver != NULL)
                dns_db_closeversion(db, &ver, ISC_TF(result == ISC_R_SUCCESS));

        return (result);
}

/*
 * Synchronize the set of initializing keys found in managed-keys {}
 * statements with the set of trust anchors found in the managed-keys.bind
 * zone.  If a domain is no longer named in managed-keys, delete all keys
 * from that domain from the key zone.  If a domain is mentioned in in
 * managed-keys but there are no references to it in the key zone, load
 * the key zone with the initializing key(s) for that domain.
 */
static isc_result_t
sync_keyzone(dns_zone_t *zone, dns_db_t *db) {
        isc_result_t result = ISC_R_SUCCESS;
        isc_boolean_t changed = ISC_FALSE;
        isc_boolean_t commit = ISC_FALSE;
        dns_rbtnodechain_t chain;
        dns_fixedname_t fn;
        dns_name_t foundname, *origin;
        dns_keynode_t *keynode = NULL;
        dns_view_t *view = zone->view;
        dns_keytable_t *sr = NULL;
        dns_dbversion_t *ver = NULL;
        dns_diff_t diff;
        dns_rriterator_t rrit;

        dns_zone_log(zone, ISC_LOG_DEBUG(1), "synchronizing trusted keys");

        dns_name_init(&foundname, NULL);
        dns_fixedname_init(&fn);
        origin = dns_fixedname_name(&fn);

        dns_diff_init(zone->mctx, &diff);

        CHECK(dns_view_getsecroots(view, &sr));

        result = dns_db_newversion(db, &ver);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "sync_keyzone:dns_db_newversion -> %s",
                             dns_result_totext(result));
                goto failure;
        }

        /*
         * Walk the zone DB.  If we find any keys whose names are no longer
         * in managed-keys (or *are* in trusted-keys, meaning they are
         * permanent and not RFC5011-maintained), delete them from the
         * zone.  Otherwise call load_secroots(), which loads keys into
         * secroots as appropriate.
         */
        dns_rriterator_init(&rrit, db, ver, 0);
        for (result = dns_rriterator_first(&rrit);
             result == ISC_R_SUCCESS;
             result = dns_rriterator_nextrrset(&rrit)) {
                dns_rdataset_t *rdataset = NULL;
                dns_name_t *rrname = NULL;
                isc_uint32_t ttl;

                dns_rriterator_current(&rrit, &rrname, &ttl,
                                       &rdataset, NULL);
                if (!dns_rdataset_isassociated(rdataset)) {
                        dns_rriterator_destroy(&rrit);
                        goto failure;
                }

                if (rdataset->type != dns_rdatatype_keydata)
                        continue;

                result = dns_keytable_find(sr, rrname, &keynode);
                if ((result != ISC_R_SUCCESS &&
                     result != DNS_R_PARTIALMATCH) ||
                    dns_keynode_managed(keynode) == ISC_FALSE) {
                        CHECK(delete_keydata(db, ver, &diff,
                                             rrname, rdataset));
                        changed = ISC_TRUE;
                } else {
                        load_secroots(zone, rrname, rdataset);
                }

                if (keynode != NULL)
                        dns_keytable_detachkeynode(sr, &keynode);
        }
        dns_rriterator_destroy(&rrit);

        /*
         * Now walk secroots to find any managed keys that aren't
         * in the zone.  If we find any, we add them to the zone.
         */
        RWLOCK(&sr->rwlock, isc_rwlocktype_write);
        dns_rbtnodechain_init(&chain, zone->mctx);
        result = dns_rbtnodechain_first(&chain, sr->table, &foundname, origin);
        if (result == ISC_R_NOTFOUND)
                result = ISC_R_NOMORE;
        while (result == DNS_R_NEWORIGIN || result == ISC_R_SUCCESS) {
                dns_rbtnode_t *rbtnode = NULL;

                dns_rbtnodechain_current(&chain, &foundname, origin, &rbtnode);
                if (rbtnode->data == NULL)
                        goto skip;

                dns_keytable_attachkeynode(sr, rbtnode->data, &keynode);
                if (dns_keynode_managed(keynode)) {
                        dns_fixedname_t fname;
                        dns_name_t *keyname;
                        dst_key_t *key;

                        key = dns_keynode_key(keynode);
                        dns_fixedname_init(&fname);

                        if (key == NULL)   /* fail_secure() was called. */
                                goto skip;

                        keyname = dst_key_name(key);
                        result = dns_db_find(db, keyname, ver,
                                             dns_rdatatype_keydata,
                                             DNS_DBFIND_NOWILD, 0, NULL,
                                             dns_fixedname_name(&fname),
                                             NULL, NULL);
                        if (result != ISC_R_SUCCESS)
                                result = create_keydata(zone, db, ver, &diff,
                                                        sr, &keynode, &changed);
                        if (result != ISC_R_SUCCESS)
                                break;
                }
  skip:
                result = dns_rbtnodechain_next(&chain, &foundname, origin);
                if (keynode != NULL)
                        dns_keytable_detachkeynode(sr, &keynode);
        }
        RWUNLOCK(&sr->rwlock, isc_rwlocktype_write);

        if (result == ISC_R_NOMORE)
                result = ISC_R_SUCCESS;

        if (changed) {
                /* Write changes to journal file. */
                CHECK(increment_soa_serial(db, ver, &diff, zone->mctx));
                CHECK(zone_journal(zone, &diff, "sync_keyzone"));

                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_LOADED);
                zone_needdump(zone, 30);
                commit = ISC_TRUE;
        }

 failure:
        if (keynode != NULL)
                dns_keytable_detachkeynode(sr, &keynode);
        if (sr != NULL)
                dns_keytable_detach(&sr);
        if (ver != NULL)
                dns_db_closeversion(db, &ver, commit);
        dns_diff_clear(&diff);

        return (result);
}

static isc_result_t
zone_postload(dns_zone_t *zone, dns_db_t *db, isc_time_t loadtime,
              isc_result_t result)
{
        unsigned int soacount = 0;
        unsigned int nscount = 0;
        unsigned int errors = 0;
        isc_uint32_t serial, oldserial, refresh, retry, expire, minimum;
        isc_time_t now;
        isc_boolean_t needdump = ISC_FALSE;
        isc_boolean_t hasinclude = DNS_ZONE_FLAG(zone, DNS_ZONEFLG_HASINCLUDE);
        isc_boolean_t nomaster = ISC_FALSE;
        unsigned int options;

        TIME_NOW(&now);

        /*
         * Initiate zone transfer?  We may need a error code that
         * indicates that the "permanent" form does not exist.
         * XXX better error feedback to log.
         */
        if (result != ISC_R_SUCCESS && result != DNS_R_SEENINCLUDE) {
                if (zone->type == dns_zone_slave ||
                    zone->type == dns_zone_stub) {
                        if (result == ISC_R_FILENOTFOUND)
                                dns_zone_log(zone, ISC_LOG_DEBUG(1),
                                             "no master file");
                        else if (result != DNS_R_NOMASTERFILE)
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "loading from master file %s "
                                             "failed: %s",
                                             zone->masterfile,
                                             dns_result_totext(result));
                } else {
                        int level = ISC_LOG_ERROR;
                        if (zone->type == dns_zone_key &&
                            result == ISC_R_FILENOTFOUND)
                                level = ISC_LOG_DEBUG(1);
                        dns_zone_log(zone, level,
                                     "loading from master file %s failed: %s",
                                     zone->masterfile,
                                     dns_result_totext(result));
                        nomaster = ISC_TRUE;
                }

                if (zone->type != dns_zone_key)
                        goto cleanup;
        }

        dns_zone_log(zone, ISC_LOG_DEBUG(2),
                     "number of nodes in database: %u",
                     dns_db_nodecount(db));

        if (result == DNS_R_SEENINCLUDE)
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_HASINCLUDE);
        else
                DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_HASINCLUDE);

        /*
         * If there's no master file for a key zone, then the zone is new:
         * create an SOA record.  (We do this now, instead of later, so that
         * if there happens to be a journal file, we can roll forward from
         * a sane starting point.)
         */
        if (nomaster && zone->type == dns_zone_key) {
                result = add_soa(zone, db);
                if (result != ISC_R_SUCCESS)
                        goto cleanup;
        }

        /*
         * Apply update log, if any, on initial load.
         */
        if (zone->journal != NULL &&
            ! DNS_ZONE_OPTION(zone, DNS_ZONEOPT_NOMERGE) &&
            ! DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED))
        {
                if (zone->type == dns_zone_master &&
                    (zone->update_acl != NULL || zone->ssutable != NULL))
                        options = DNS_JOURNALOPT_RESIGN;
                else
                        options = 0;
                result = dns_journal_rollforward2(zone->mctx, db, options,
                                                  zone->sigresigninginterval,
                                                  zone->journal);
                if (result != ISC_R_SUCCESS && result != ISC_R_NOTFOUND &&
                    result != DNS_R_UPTODATE && result != DNS_R_NOJOURNAL &&
                    result != ISC_R_RANGE) {
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "journal rollforward failed: %s",
                                     dns_result_totext(result));
                        goto cleanup;
                }
                if (result == ISC_R_NOTFOUND || result == ISC_R_RANGE) {
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "journal rollforward failed: "
                                     "journal out of sync with zone");
                        goto cleanup;
                }
                dns_zone_log(zone, ISC_LOG_DEBUG(1),
                             "journal rollforward completed "
                             "successfully: %s",
                             dns_result_totext(result));
                if (result == ISC_R_SUCCESS)
                        needdump = ISC_TRUE;
        }

        dns_zone_log(zone, ISC_LOG_DEBUG(1), "loaded; checking validity");
        /*
         * Obtain ns, soa and cname counts for top of zone.
         */
        INSIST(db != NULL);
        result = zone_get_from_db(zone, db, &nscount, &soacount, &serial,
                                  &refresh, &retry, &expire, &minimum,
                                  &errors);
        if (result != ISC_R_SUCCESS && zone->type != dns_zone_key) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "could not find NS and/or SOA records");
        }

        /*
         * Master / Slave / Stub zones require both NS and SOA records at
         * the top of the zone.
         */

        switch (zone->type) {
        case dns_zone_dlz:
        case dns_zone_master:
        case dns_zone_slave:
        case dns_zone_stub:
                if (soacount != 1) {
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "has %d SOA records", soacount);
                        result = DNS_R_BADZONE;
                }
                if (nscount == 0) {
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "has no NS records");
                        result = DNS_R_BADZONE;
                }
                if (result != ISC_R_SUCCESS)
                        goto cleanup;
                if (zone->type == dns_zone_master && errors != 0) {
                        result = DNS_R_BADZONE;
                        goto cleanup;
                }
                if (zone->type != dns_zone_stub) {
                        result = check_nsec3param(zone, db);
                        if (result != ISC_R_SUCCESS)
                                goto cleanup;
                }
                if (zone->type == dns_zone_master &&
                    DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKINTEGRITY) &&
                    !integrity_checks(zone, db)) {
                        result = DNS_R_BADZONE;
                        goto cleanup;
                }

                if (zone->type == dns_zone_master &&
                    DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKDUPRR) &&
                    !zone_check_dup(zone, db)) {
                        result = DNS_R_BADZONE;
                        goto cleanup;
                }

                if (zone->db != NULL) {
                        /*
                         * This is checked in zone_replacedb() for slave zones
                         * as they don't reload from disk.
                         */
                        result = zone_get_from_db(zone, zone->db, NULL, NULL,
                                                  &oldserial, NULL, NULL, NULL,
                                                  NULL, NULL);
                        RUNTIME_CHECK(result == ISC_R_SUCCESS);
                        if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IXFRFROMDIFFS) &&
                            !isc_serial_gt(serial, oldserial)) {
                                isc_uint32_t serialmin, serialmax;

                                INSIST(zone->type == dns_zone_master);

                                serialmin = (oldserial + 1) & 0xffffffffU;
                                serialmax = (oldserial + 0x7fffffffU) &
                                             0xffffffffU;
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "ixfr-from-differences: "
                                             "new serial (%u) out of range "
                                             "[%u - %u]", serial, serialmin,
                                             serialmax);
                                result = DNS_R_BADZONE;
                                goto cleanup;
                        } else if (!isc_serial_ge(serial, oldserial))
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "zone serial (%u/%u) has gone "
                                             "backwards", serial, oldserial);
                        else if (serial == oldserial && !hasinclude &&
                                 strcmp(zone->db_argv[0], "_builtin") != 0)
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "zone serial (%u) unchanged. "
                                             "zone may fail to transfer "
                                             "to slaves.", serial);
                }

                if (zone->type == dns_zone_master &&
                    (zone->update_acl != NULL || zone->ssutable != NULL) &&
                    zone->sigresigninginterval < (3 * refresh) &&
                    dns_db_issecure(db))
                {
                        dns_zone_log(zone, ISC_LOG_WARNING,
                                     "sig-re-signing-interval less than "
                                     "3 * refresh.");
                }

                zone->refresh = RANGE(refresh,
                                      zone->minrefresh, zone->maxrefresh);
                zone->retry = RANGE(retry,
                                    zone->minretry, zone->maxretry);
                zone->expire = RANGE(expire, zone->refresh + zone->retry,
                                     DNS_MAX_EXPIRE);
                zone->minimum = minimum;
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_HAVETIMERS);

                if (zone->type == dns_zone_slave ||
                    zone->type == dns_zone_stub) {
                        isc_time_t t;
                        isc_uint32_t delay;

                        result = isc_file_getmodtime(zone->journal, &t);
                        if (result != ISC_R_SUCCESS)
                                result = isc_file_getmodtime(zone->masterfile,
                                                             &t);
                        if (result == ISC_R_SUCCESS)
                                DNS_ZONE_TIME_ADD(&t, zone->expire,
                                                  &zone->expiretime);
                        else
                                DNS_ZONE_TIME_ADD(&now, zone->retry,
                                                  &zone->expiretime);

                        delay = isc_random_jitter(zone->retry,
                                                  (zone->retry * 3) / 4);
                        DNS_ZONE_TIME_ADD(&now, delay, &zone->refreshtime);
                        if (isc_time_compare(&zone->refreshtime,
                                             &zone->expiretime) >= 0)
                                zone->refreshtime = now;
                }
                break;

        case dns_zone_key:
                result = sync_keyzone(zone, db);
                if (result != ISC_R_SUCCESS)
                        goto cleanup;
                break;

        default:
                UNEXPECTED_ERROR(__FILE__, __LINE__,
                                 "unexpected zone type %d", zone->type);
                result = ISC_R_UNEXPECTED;
                goto cleanup;
        }

        /*
         * Check for weak DNSKEY's.
         */
        if (zone->type == dns_zone_master)
                zone_check_dnskeys(zone, db);

        /*
         * Schedule DNSSEC key refresh.
         */
        if (zone->type == dns_zone_master &&
            DNS_ZONEKEY_OPTION(zone, DNS_ZONEKEY_MAINTAIN))
                zone->refreshkeytime = now;

#if 0
        /* destroy notification example. */
        {
                isc_event_t *e = isc_event_allocate(zone->mctx, NULL,
                                                    DNS_EVENT_DBDESTROYED,
                                                    dns_zonemgr_dbdestroyed,
                                                    zone,
                                                    sizeof(isc_event_t));
                dns_db_ondestroy(db, zone->task, &e);
        }
#endif

        ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_write);
        if (zone->db != NULL) {
                result = zone_replacedb(zone, db, ISC_FALSE);
                ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_write);
                if (result != ISC_R_SUCCESS)
                        goto cleanup;
        } else {
                zone_attachdb(zone, db);
                ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_write);
                DNS_ZONE_SETFLAG(zone,
                                 DNS_ZONEFLG_LOADED|DNS_ZONEFLG_NEEDNOTIFY);
        }

        result = ISC_R_SUCCESS;

        if (needdump) {
                if (zone->type == dns_zone_key)
                        zone_needdump(zone, 30);
                else
                        zone_needdump(zone, DNS_DUMP_DELAY);
        }

        if (zone->task != NULL) {
                if (zone->type == dns_zone_master) {
                        set_resigntime(zone);
                        resume_signingwithkey(zone);
                        resume_addnsec3chain(zone);
                }

                if (zone->type == dns_zone_master &&
                    zone_isdynamic(zone) &&
                    dns_db_issecure(db)) {
                        dns_name_t *name;
                        dns_fixedname_t fixed;
                        dns_rdataset_t next;

                        dns_rdataset_init(&next);
                        dns_fixedname_init(&fixed);
                        name = dns_fixedname_name(&fixed);

                        result = dns_db_getsigningtime(db, &next, name);
                        if (result == ISC_R_SUCCESS) {
                                isc_stdtime_t timenow;
                                char namebuf[DNS_NAME_FORMATSIZE];
                                char typebuf[DNS_RDATATYPE_FORMATSIZE];

                                isc_stdtime_get(&timenow);
                                dns_name_format(name, namebuf, sizeof(namebuf));
                                dns_rdatatype_format(next.covers,
                                                     typebuf, sizeof(typebuf));
                                dns_zone_log(zone, ISC_LOG_DEBUG(3),
                                             "next resign: %s/%s in %d seconds",
                                             namebuf, typebuf,
                                             next.resign - timenow);
                                dns_rdataset_disassociate(&next);
                        } else
                                dns_zone_log(zone, ISC_LOG_WARNING,
                                             "signed dynamic zone has no "
                                             "resign event scheduled");
                }

                zone_settimer(zone, &now);
        }

        if (! dns_db_ispersistent(db))
                dns_zone_log(zone, ISC_LOG_INFO, "loaded serial %u%s", serial,
                             dns_db_issecure(db) ? " (DNSSEC signed)" : "");

        zone->loadtime = loadtime;
        return (result);

 cleanup:
        if (zone->type == dns_zone_slave ||
            zone->type == dns_zone_stub ||
            zone->type == dns_zone_key) {
                if (zone->journal != NULL)
                        zone_saveunique(zone, zone->journal, "jn-XXXXXXXX");
                if (zone->masterfile != NULL)
                        zone_saveunique(zone, zone->masterfile, "db-XXXXXXXX");

                /* Mark the zone for immediate refresh. */
                zone->refreshtime = now;
                if (zone->task != NULL)
                        zone_settimer(zone, &now);
                result = ISC_R_SUCCESS;
        } else if (zone->type == dns_zone_master)
                dns_zone_log(zone, ISC_LOG_ERROR, "not loaded due to errors.");
        return (result);
}

static isc_boolean_t
exit_check(dns_zone_t *zone) {

        REQUIRE(LOCKED_ZONE(zone));

        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_SHUTDOWN) &&
            zone->irefs == 0)
        {
                /*
                 * DNS_ZONEFLG_SHUTDOWN can only be set if erefs == 0.
                 */
                INSIST(isc_refcount_current(&zone->erefs) == 0);
                return (ISC_TRUE);
        }
        return (ISC_FALSE);
}

static isc_boolean_t
zone_check_ns(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *version,
              dns_name_t *name, isc_boolean_t logit)
{
        isc_result_t result;
        char namebuf[DNS_NAME_FORMATSIZE];
        char altbuf[DNS_NAME_FORMATSIZE];
        dns_fixedname_t fixed;
        dns_name_t *foundname;
        int level;

        if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_NOCHECKNS))
                return (ISC_TRUE);

        if (zone->type == dns_zone_master)
                level = ISC_LOG_ERROR;
        else
                level = ISC_LOG_WARNING;

        dns_fixedname_init(&fixed);
        foundname = dns_fixedname_name(&fixed);

        result = dns_db_find(db, name, version, dns_rdatatype_a,
                             0, 0, NULL, foundname, NULL, NULL);
        if (result == ISC_R_SUCCESS)
                return (ISC_TRUE);

        if (result == DNS_R_NXRRSET) {
                result = dns_db_find(db, name, version, dns_rdatatype_aaaa,
                                     0, 0, NULL, foundname, NULL, NULL);
                if (result == ISC_R_SUCCESS)
                        return (ISC_TRUE);
        }

        if (result == DNS_R_NXRRSET || result == DNS_R_NXDOMAIN ||
            result == DNS_R_EMPTYNAME) {
                if (logit) {
                        dns_name_format(name, namebuf, sizeof namebuf);
                        dns_zone_log(zone, level, "NS '%s' has no address "
                                     "records (A or AAAA)", namebuf);
                }
                return (ISC_FALSE);
        }

        if (result == DNS_R_CNAME) {
                if (logit) {
                        dns_name_format(name, namebuf, sizeof namebuf);
                        dns_zone_log(zone, level, "NS '%s' is a CNAME "
                                     "(illegal)", namebuf);
                }
                return (ISC_FALSE);
        }

        if (result == DNS_R_DNAME) {
                if (logit) {
                        dns_name_format(name, namebuf, sizeof namebuf);
                        dns_name_format(foundname, altbuf, sizeof altbuf);
                        dns_zone_log(zone, level, "NS '%s' is below a DNAME "
                                     "'%s' (illegal)", namebuf, altbuf);
                }
                return (ISC_FALSE);
        }

        return (ISC_TRUE);
}

static isc_result_t
zone_count_ns_rr(dns_zone_t *zone, dns_db_t *db, dns_dbnode_t *node,
                 dns_dbversion_t *version, unsigned int *nscount,
                 unsigned int *errors, isc_boolean_t logit)
{
        isc_result_t result;
        unsigned int count = 0;
        unsigned int ecount = 0;
        dns_rdataset_t rdataset;
        dns_rdata_t rdata;
        dns_rdata_ns_t ns;

        dns_rdataset_init(&rdataset);
        result = dns_db_findrdataset(db, node, version, dns_rdatatype_ns,
                                     dns_rdatatype_none, 0, &rdataset, NULL);
        if (result == ISC_R_NOTFOUND) {
                INSIST(!dns_rdataset_isassociated(&rdataset));
                goto success;
        }
        if (result != ISC_R_SUCCESS) {
                INSIST(!dns_rdataset_isassociated(&rdataset));
                goto invalidate_rdataset;
        }

        result = dns_rdataset_first(&rdataset);
        while (result == ISC_R_SUCCESS) {
                if (errors != NULL && zone->rdclass == dns_rdataclass_in &&
                    (zone->type == dns_zone_master ||
                     zone->type == dns_zone_slave)) {
                        dns_rdata_init(&rdata);
                        dns_rdataset_current(&rdataset, &rdata);
                        result = dns_rdata_tostruct(&rdata, &ns, NULL);
                        RUNTIME_CHECK(result == ISC_R_SUCCESS);
                        if (dns_name_issubdomain(&ns.name, &zone->origin) &&
                            !zone_check_ns(zone, db, version, &ns.name, logit))
                                ecount++;
                }
                count++;
                result = dns_rdataset_next(&rdataset);
        }
        dns_rdataset_disassociate(&rdataset);

 success:
        if (nscount != NULL)
                *nscount = count;
        if (errors != NULL)
                *errors = ecount;

        result = ISC_R_SUCCESS;

 invalidate_rdataset:
        dns_rdataset_invalidate(&rdataset);

        return (result);
}

static isc_result_t
zone_load_soa_rr(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
                 unsigned int *soacount,
                 isc_uint32_t *serial, isc_uint32_t *refresh,
                 isc_uint32_t *retry, isc_uint32_t *expire,
                 isc_uint32_t *minimum)
{
        isc_result_t result;
        unsigned int count;
        dns_rdataset_t rdataset;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_rdata_soa_t soa;

        dns_rdataset_init(&rdataset);
        result = dns_db_findrdataset(db, node, version, dns_rdatatype_soa,
                                     dns_rdatatype_none, 0, &rdataset, NULL);
        if (result == ISC_R_NOTFOUND) {
                INSIST(!dns_rdataset_isassociated(&rdataset));
                if (soacount != NULL)
                        *soacount = 0;
                if (serial != NULL)
                        *serial = 0;
                if (refresh != NULL)
                        *refresh = 0;
                if (retry != NULL)
                        *retry = 0;
                if (expire != NULL)
                        *expire = 0;
                if (minimum != NULL)
                        *minimum = 0;
                result = ISC_R_SUCCESS;
                goto invalidate_rdataset;
        }
        if (result != ISC_R_SUCCESS) {
                INSIST(!dns_rdataset_isassociated(&rdataset));
                goto invalidate_rdataset;
        }

        count = 0;
        result = dns_rdataset_first(&rdataset);
        while (result == ISC_R_SUCCESS) {
                dns_rdata_init(&rdata);
                dns_rdataset_current(&rdataset, &rdata);
                count++;
                if (count == 1) {
                        result = dns_rdata_tostruct(&rdata, &soa, NULL);
                        RUNTIME_CHECK(result == ISC_R_SUCCESS);
                }

                result = dns_rdataset_next(&rdataset);
                dns_rdata_reset(&rdata);
        }
        dns_rdataset_disassociate(&rdataset);

        if (soacount != NULL)
                *soacount = count;

        if (count > 0) {
                if (serial != NULL)
                        *serial = soa.serial;
                if (refresh != NULL)
                        *refresh = soa.refresh;
                if (retry != NULL)
                        *retry = soa.retry;
                if (expire != NULL)
                        *expire = soa.expire;
                if (minimum != NULL)
                        *minimum = soa.minimum;
        }

        result = ISC_R_SUCCESS;

 invalidate_rdataset:
        dns_rdataset_invalidate(&rdataset);

        return (result);
}

/*
 * zone must be locked.
 */
static isc_result_t
zone_get_from_db(dns_zone_t *zone, dns_db_t *db, unsigned int *nscount,
                 unsigned int *soacount, isc_uint32_t *serial,
                 isc_uint32_t *refresh, isc_uint32_t *retry,
                 isc_uint32_t *expire, isc_uint32_t *minimum,
                 unsigned int *errors)
{
        isc_result_t result;
        isc_result_t answer = ISC_R_SUCCESS;
        dns_dbversion_t *version = NULL;
        dns_dbnode_t *node;

        REQUIRE(db != NULL);
        REQUIRE(zone != NULL);

        dns_db_currentversion(db, &version);

        node = NULL;
        result = dns_db_findnode(db, &zone->origin, ISC_FALSE, &node);
        if (result != ISC_R_SUCCESS) {
                answer = result;
                goto closeversion;
        }

        if (nscount != NULL || errors != NULL) {
                result = zone_count_ns_rr(zone, db, node, version,
                                          nscount, errors, ISC_TRUE);
                if (result != ISC_R_SUCCESS)
                        answer = result;
        }

        if (soacount != NULL || serial != NULL || refresh != NULL
            || retry != NULL || expire != NULL || minimum != NULL) {
                result = zone_load_soa_rr(db, node, version, soacount,
                                          serial, refresh, retry, expire,
                                          minimum);
                if (result != ISC_R_SUCCESS)
                        answer = result;
        }

        dns_db_detachnode(db, &node);
 closeversion:
        dns_db_closeversion(db, &version, ISC_FALSE);

        return (answer);
}

void
dns_zone_attach(dns_zone_t *source, dns_zone_t **target) {
        REQUIRE(DNS_ZONE_VALID(source));
        REQUIRE(target != NULL && *target == NULL);
        isc_refcount_increment(&source->erefs, NULL);
        *target = source;
}

void
dns_zone_detach(dns_zone_t **zonep) {
        dns_zone_t *zone;
        unsigned int refs;
        isc_boolean_t free_now = ISC_FALSE;

        REQUIRE(zonep != NULL && DNS_ZONE_VALID(*zonep));

        zone = *zonep;

        isc_refcount_decrement(&zone->erefs, &refs);

        if (refs == 0) {
                LOCK_ZONE(zone);
                /*
                 * We just detached the last external reference.
                 */
                if (zone->task != NULL) {
                        /*
                         * This zone is being managed.  Post
                         * its control event and let it clean
                         * up synchronously in the context of
                         * its task.
                         */
                        isc_event_t *ev = &zone->ctlevent;
                        isc_task_send(zone->task, &ev);
                } else {
                        /*
                         * This zone is not being managed; it has
                         * no task and can have no outstanding
                         * events.  Free it immediately.
                         */
                        /*
                         * Unmanaged zones should not have non-null views;
                         * we have no way of detaching from the view here
                         * without causing deadlock because this code is called
                         * with the view already locked.
                         */
                        INSIST(zone->view == NULL);
                        free_now = ISC_TRUE;
                }
                UNLOCK_ZONE(zone);
        }
        *zonep = NULL;
        if (free_now)
                zone_free(zone);
}

void
dns_zone_iattach(dns_zone_t *source, dns_zone_t **target) {
        REQUIRE(DNS_ZONE_VALID(source));
        REQUIRE(target != NULL && *target == NULL);
        LOCK_ZONE(source);
        zone_iattach(source, target);
        UNLOCK_ZONE(source);
}

isc_result_t
dns_zone_synckeyzone(dns_zone_t *zone) {
        isc_result_t result;
        dns_db_t *db = NULL;

        if (zone->type != dns_zone_key)
                return (DNS_R_BADZONE);

        CHECK(dns_zone_getdb(zone, &db));

        LOCK_ZONE(zone);
        result = sync_keyzone(zone, db);
        UNLOCK_ZONE(zone);

 failure:
        if (db != NULL)
                dns_db_detach(&db);
        return (result);
}

static void
zone_iattach(dns_zone_t *source, dns_zone_t **target) {

        /*
         * 'source' locked by caller.
         */
        REQUIRE(LOCKED_ZONE(source));
        REQUIRE(DNS_ZONE_VALID(source));
        REQUIRE(target != NULL && *target == NULL);
        INSIST(source->irefs + isc_refcount_current(&source->erefs) > 0);
        source->irefs++;
        INSIST(source->irefs != 0);
        *target = source;
}

static void
zone_idetach(dns_zone_t **zonep) {
        dns_zone_t *zone;

        /*
         * 'zone' locked by caller.
         */
        REQUIRE(zonep != NULL && DNS_ZONE_VALID(*zonep));
        zone = *zonep;
        REQUIRE(LOCKED_ZONE(*zonep));
        *zonep = NULL;

        INSIST(zone->irefs > 0);
        zone->irefs--;
        INSIST(zone->irefs + isc_refcount_current(&zone->erefs) > 0);
}

void
dns_zone_idetach(dns_zone_t **zonep) {
        dns_zone_t *zone;
        isc_boolean_t free_needed;

        REQUIRE(zonep != NULL && DNS_ZONE_VALID(*zonep));
        zone = *zonep;
        *zonep = NULL;

        LOCK_ZONE(zone);
        INSIST(zone->irefs > 0);
        zone->irefs--;
        free_needed = exit_check(zone);
        UNLOCK_ZONE(zone);
        if (free_needed)
                zone_free(zone);
}

isc_mem_t *
dns_zone_getmctx(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->mctx);
}

dns_zonemgr_t *
dns_zone_getmgr(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->zmgr);
}

void
dns_zone_setflag(dns_zone_t *zone, unsigned int flags, isc_boolean_t value) {
        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        if (value)
                DNS_ZONE_SETFLAG(zone, flags);
        else
                DNS_ZONE_CLRFLAG(zone, flags);
        UNLOCK_ZONE(zone);
}

void
dns_zone_setoption(dns_zone_t *zone, unsigned int option, isc_boolean_t value)
{
        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        if (value)
                zone->options |= option;
        else
                zone->options &= ~option;
        UNLOCK_ZONE(zone);
}

unsigned int
dns_zone_getoptions(dns_zone_t *zone) {

        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->options);
}

void
dns_zone_setkeyopt(dns_zone_t *zone, unsigned int keyopt, isc_boolean_t value)
{
        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        if (value)
                zone->keyopts |= keyopt;
        else
                zone->keyopts &= ~keyopt;
        UNLOCK_ZONE(zone);
}

unsigned int
dns_zone_getkeyopts(dns_zone_t *zone) {

        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->keyopts);
}

isc_result_t
dns_zone_setxfrsource4(dns_zone_t *zone, const isc_sockaddr_t *xfrsource) {
        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        zone->xfrsource4 = *xfrsource;
        UNLOCK_ZONE(zone);

        return (ISC_R_SUCCESS);
}

isc_sockaddr_t *
dns_zone_getxfrsource4(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));
        return (&zone->xfrsource4);
}

isc_result_t
dns_zone_setxfrsource6(dns_zone_t *zone, const isc_sockaddr_t *xfrsource) {
        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        zone->xfrsource6 = *xfrsource;
        UNLOCK_ZONE(zone);

        return (ISC_R_SUCCESS);
}

isc_sockaddr_t *
dns_zone_getxfrsource6(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));
        return (&zone->xfrsource6);
}

isc_result_t
dns_zone_setaltxfrsource4(dns_zone_t *zone,
                          const isc_sockaddr_t *altxfrsource)
{
        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        zone->altxfrsource4 = *altxfrsource;
        UNLOCK_ZONE(zone);

        return (ISC_R_SUCCESS);
}

isc_sockaddr_t *
dns_zone_getaltxfrsource4(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));
        return (&zone->altxfrsource4);
}

isc_result_t
dns_zone_setaltxfrsource6(dns_zone_t *zone,
                          const isc_sockaddr_t *altxfrsource)
{
        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        zone->altxfrsource6 = *altxfrsource;
        UNLOCK_ZONE(zone);

        return (ISC_R_SUCCESS);
}

isc_sockaddr_t *
dns_zone_getaltxfrsource6(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));
        return (&zone->altxfrsource6);
}

isc_result_t
dns_zone_setnotifysrc4(dns_zone_t *zone, const isc_sockaddr_t *notifysrc) {
        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        zone->notifysrc4 = *notifysrc;
        UNLOCK_ZONE(zone);

        return (ISC_R_SUCCESS);
}

isc_sockaddr_t *
dns_zone_getnotifysrc4(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));
        return (&zone->notifysrc4);
}

isc_result_t
dns_zone_setnotifysrc6(dns_zone_t *zone, const isc_sockaddr_t *notifysrc) {
        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        zone->notifysrc6 = *notifysrc;
        UNLOCK_ZONE(zone);

        return (ISC_R_SUCCESS);
}

isc_sockaddr_t *
dns_zone_getnotifysrc6(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));
        return (&zone->notifysrc6);
}

isc_result_t
dns_zone_setalsonotify(dns_zone_t *zone, const isc_sockaddr_t *notify,
                       isc_uint32_t count)
{
        isc_sockaddr_t *new;

        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(count == 0 || notify != NULL);

        LOCK_ZONE(zone);
        if (zone->notify != NULL) {
                isc_mem_put(zone->mctx, zone->notify,
                            zone->notifycnt * sizeof(*new));
                zone->notify = NULL;
                zone->notifycnt = 0;
        }
        if (count != 0) {
                new = isc_mem_get(zone->mctx, count * sizeof(*new));
                if (new == NULL) {
                        UNLOCK_ZONE(zone);
                        return (ISC_R_NOMEMORY);
                }
                memcpy(new, notify, count * sizeof(*new));
                zone->notify = new;
                zone->notifycnt = count;
        }
        UNLOCK_ZONE(zone);
        return (ISC_R_SUCCESS);
}

isc_result_t
dns_zone_setmasters(dns_zone_t *zone, const isc_sockaddr_t *masters,
                    isc_uint32_t count)
{
        isc_result_t result;

        result = dns_zone_setmasterswithkeys(zone, masters, NULL, count);
        return (result);
}

static isc_boolean_t
same_masters(const isc_sockaddr_t *old, const isc_sockaddr_t *new,
             isc_uint32_t count)
{
        unsigned int i;

        for (i = 0; i < count; i++)
                if (!isc_sockaddr_equal(&old[i], &new[i]))
                        return (ISC_FALSE);
        return (ISC_TRUE);
}

static isc_boolean_t
same_keynames(dns_name_t **old, dns_name_t **new, isc_uint32_t count) {
        unsigned int i;

        if (old == NULL && new == NULL)
                return (ISC_TRUE);
        if (old == NULL || new == NULL)
                return (ISC_FALSE);

        for (i = 0; i < count; i++) {
                if (old[i] == NULL && new[i] == NULL)
                        continue;
                if (old[i] == NULL || new[i] == NULL ||
                     !dns_name_equal(old[i], new[i]))
                        return (ISC_FALSE);
        }
        return (ISC_TRUE);
}

isc_result_t
dns_zone_setmasterswithkeys(dns_zone_t *zone,
                            const isc_sockaddr_t *masters,
                            dns_name_t **keynames,
                            isc_uint32_t count)
{
        isc_sockaddr_t *new;
        isc_result_t result = ISC_R_SUCCESS;
        dns_name_t **newname;
        isc_boolean_t *newok;
        unsigned int i;

        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(count == 0 || masters != NULL);
        if (keynames != NULL) {
                REQUIRE(count != 0);
        }

        LOCK_ZONE(zone);
        /*
         * The refresh code assumes that 'masters' wouldn't change under it.
         * If it will change then kill off any current refresh in progress
         * and update the masters info.  If it won't change then we can just
         * unlock and exit.
         */
        if (count != zone->masterscnt ||
            !same_masters(zone->masters, masters, count) ||
            !same_keynames(zone->masterkeynames, keynames, count)) {
                if (zone->request != NULL)
                        dns_request_cancel(zone->request);
        } else
                goto unlock;
        if (zone->masters != NULL) {
                isc_mem_put(zone->mctx, zone->masters,
                            zone->masterscnt * sizeof(*new));
                zone->masters = NULL;
        }
        if (zone->masterkeynames != NULL) {
                for (i = 0; i < zone->masterscnt; i++) {
                        if (zone->masterkeynames[i] != NULL) {
                                dns_name_free(zone->masterkeynames[i],
                                              zone->mctx);
                                isc_mem_put(zone->mctx,
                                            zone->masterkeynames[i],
                                            sizeof(dns_name_t));
                                zone->masterkeynames[i] = NULL;
                        }
                }
                isc_mem_put(zone->mctx, zone->masterkeynames,
                            zone->masterscnt * sizeof(dns_name_t *));
                zone->masterkeynames = NULL;
        }
        if (zone->mastersok != NULL) {
                isc_mem_put(zone->mctx, zone->mastersok,
                            zone->masterscnt * sizeof(isc_boolean_t));
                zone->mastersok = NULL;
        }
        zone->masterscnt = 0;
        /*
         * If count == 0, don't allocate any space for masters, mastersok or
         * keynames so internally, those pointers are NULL if count == 0
         */
        if (count == 0)
                goto unlock;

        /*
         * masters must contain count elements!
         */
        new = isc_mem_get(zone->mctx, count * sizeof(*new));
        if (new == NULL) {
                result = ISC_R_NOMEMORY;
                goto unlock;
        }
        memcpy(new, masters, count * sizeof(*new));

        /*
         * Similarly for mastersok.
         */
        newok = isc_mem_get(zone->mctx, count * sizeof(*newok));
        if (newok == NULL) {
                result = ISC_R_NOMEMORY;
                isc_mem_put(zone->mctx, new, count * sizeof(*new));
                goto unlock;
        };
        for (i = 0; i < count; i++)
                newok[i] = ISC_FALSE;

        /*
         * if keynames is non-NULL, it must contain count elements!
         */
        newname = NULL;
        if (keynames != NULL) {
                newname = isc_mem_get(zone->mctx, count * sizeof(*newname));
                if (newname == NULL) {
                        result = ISC_R_NOMEMORY;
                        isc_mem_put(zone->mctx, new, count * sizeof(*new));
                        isc_mem_put(zone->mctx, newok, count * sizeof(*newok));
                        goto unlock;
                }
                for (i = 0; i < count; i++)
                        newname[i] = NULL;
                for (i = 0; i < count; i++) {
                        if (keynames[i] != NULL) {
                                newname[i] = isc_mem_get(zone->mctx,
                                                         sizeof(dns_name_t));
                                if (newname[i] == NULL)
                                        goto allocfail;
                                dns_name_init(newname[i], NULL);
                                result = dns_name_dup(keynames[i], zone->mctx,
                                                      newname[i]);
                                if (result != ISC_R_SUCCESS) {
                                allocfail:
                                        for (i = 0; i < count; i++)
                                                if (newname[i] != NULL)
                                                        dns_name_free(
                                                               newname[i],
                                                               zone->mctx);
                                        isc_mem_put(zone->mctx, new,
                                                    count * sizeof(*new));
                                        isc_mem_put(zone->mctx, newok,
                                                    count * sizeof(*newok));
                                        isc_mem_put(zone->mctx, newname,
                                                    count * sizeof(*newname));
                                        goto unlock;
                                }
                        }
                }
        }

        /*
         * Everything is ok so attach to the zone.
         */
        zone->curmaster = 0;
        zone->masters = new;
        zone->mastersok = newok;
        zone->masterkeynames = newname;
        zone->masterscnt = count;
        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NOMASTERS);

 unlock:
        UNLOCK_ZONE(zone);
        return (result);
}

isc_result_t
dns_zone_getdb(dns_zone_t *zone, dns_db_t **dpb) {
        isc_result_t result = ISC_R_SUCCESS;

        REQUIRE(DNS_ZONE_VALID(zone));

        ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
        if (zone->db == NULL)
                result = DNS_R_NOTLOADED;
        else
                dns_db_attach(zone->db, dpb);
        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);

        return (result);
}

void
dns_zone_setdb(dns_zone_t *zone, dns_db_t *db) {
        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(zone->type == dns_zone_staticstub);

        ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_write);
        REQUIRE(zone->db == NULL);
        dns_db_attach(db, &zone->db);
        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_write);
}

/*
 * Co-ordinates the starting of routine jobs.
 */

void
dns_zone_maintenance(dns_zone_t *zone) {
        const char me[] = "dns_zone_maintenance";
        isc_time_t now;

        REQUIRE(DNS_ZONE_VALID(zone));
        ENTER;

        LOCK_ZONE(zone);
        TIME_NOW(&now);
        zone_settimer(zone, &now);
        UNLOCK_ZONE(zone);
}

static inline isc_boolean_t
was_dumping(dns_zone_t *zone) {
        isc_boolean_t dumping;

        REQUIRE(LOCKED_ZONE(zone));

        dumping = DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DUMPING);
        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_DUMPING);
        if (!dumping) {
                DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NEEDDUMP);
                isc_time_settoepoch(&zone->dumptime);
        }
        return (dumping);
}

static isc_result_t
find_zone_keys(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *ver,
               isc_mem_t *mctx, unsigned int maxkeys,
               dst_key_t **keys, unsigned int *nkeys)
{
        isc_result_t result;
        dns_dbnode_t *node = NULL;
        const char *directory = dns_zone_getkeydirectory(zone);

        CHECK(dns_db_findnode(db, dns_db_origin(db), ISC_FALSE, &node));
        result = dns_dnssec_findzonekeys2(db, ver, node, dns_db_origin(db),
                                          directory, mctx, maxkeys, keys,
                                          nkeys);
        if (result == ISC_R_NOTFOUND)
                result = ISC_R_SUCCESS;
 failure:
        if (node != NULL)
                dns_db_detachnode(db, &node);
        return (result);
}

static isc_result_t
offline(dns_db_t *db, dns_dbversion_t *ver, dns_diff_t *diff, dns_name_t *name,
        dns_ttl_t ttl, dns_rdata_t *rdata)
{
        isc_result_t result;

        if ((rdata->flags & DNS_RDATA_OFFLINE) != 0)
                return (ISC_R_SUCCESS);
        result = update_one_rr(db, ver, diff, DNS_DIFFOP_DELRESIGN,
                               name, ttl, rdata);
        if (result != ISC_R_SUCCESS)
                return (result);
        rdata->flags |= DNS_RDATA_OFFLINE;
        result = update_one_rr(db, ver, diff, DNS_DIFFOP_ADDRESIGN,
                               name, ttl, rdata);
        return (result);
}

static void
set_key_expiry_warning(dns_zone_t *zone, isc_stdtime_t when, isc_stdtime_t now)
{
        unsigned int delta;
        char timebuf[80];

        zone->key_expiry = when;
        if (when <= now) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "DNSKEY RRSIG(s) have expired");
                isc_time_settoepoch(&zone->keywarntime);
        } else if (when < now + 7 * 24 * 3600) {
                isc_time_t t;
                isc_time_set(&t, when, 0);
                isc_time_formattimestamp(&t, timebuf, 80);
                dns_zone_log(zone, ISC_LOG_WARNING,
                             "DNSKEY RRSIG(s) will expire within 7 days: %s",
                             timebuf);
                delta = when - now;
                delta--;                /* loop prevention */
                delta /= 24 * 3600;     /* to whole days */
                delta *= 24 * 3600;     /* to seconds */
                isc_time_set(&zone->keywarntime, when - delta, 0);
        }  else {
                isc_time_set(&zone->keywarntime, when - 7 * 24 * 3600, 0);
                isc_time_formattimestamp(&zone->refreshkeytime, timebuf, 80);
                dns_zone_log(zone, ISC_LOG_NOTICE,
                             "setting keywarntime to %s", timebuf);
        }
}

/*
 * Helper function to del_sigs(). We don't want to delete RRSIGs that
 * have no new key.
 */
static isc_boolean_t
delsig_ok(dns_rdata_rrsig_t *rrsig_ptr, dst_key_t **keys, unsigned int nkeys) {
        unsigned int i = 0;

        /*
         * It's okay to delete a signature if there is an active ZSK
         * with the same algorithm
         */
        for (i = 0; i < nkeys; i++) {
                if (rrsig_ptr->algorithm == dst_key_alg(keys[i]) &&
                    (dst_key_isprivate(keys[i])) && !KSK(keys[i]))
                        return (ISC_TRUE);
        }

        /*
         * Failing that, it is *not* okay to delete a signature
         * if the associated public key is still in the DNSKEY RRset
         */
        for (i = 0; i < nkeys; i++) {
                if ((rrsig_ptr->algorithm == dst_key_alg(keys[i])) &&
                    (rrsig_ptr->keyid == dst_key_id(keys[i])))
                        return (ISC_FALSE);
        }

        /*
         * But if the key is gone, then go ahead.
         */
        return (ISC_TRUE);
}

/*
 * Delete expired RRsigs and any RRsigs we are about to re-sign.
 * See also update.c:del_keysigs().
 */
static isc_result_t
del_sigs(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
         dns_rdatatype_t type, dns_diff_t *diff, dst_key_t **keys,
         unsigned int nkeys, isc_stdtime_t now, isc_boolean_t incremental)
{
        isc_result_t result;
        dns_dbnode_t *node = NULL;
        dns_rdataset_t rdataset;
        unsigned int i;
        dns_rdata_rrsig_t rrsig;
        isc_boolean_t found, changed;
        isc_int64_t warn = 0, maybe = 0;

        dns_rdataset_init(&rdataset);

        if (type == dns_rdatatype_nsec3)
                result = dns_db_findnsec3node(db, name, ISC_FALSE, &node);
        else
                result = dns_db_findnode(db, name, ISC_FALSE, &node);
        if (result == ISC_R_NOTFOUND)
                return (ISC_R_SUCCESS);
        if (result != ISC_R_SUCCESS)
                goto failure;
        result = dns_db_findrdataset(db, node, ver, dns_rdatatype_rrsig, type,
                                     (isc_stdtime_t) 0, &rdataset, NULL);
        dns_db_detachnode(db, &node);

        if (result == ISC_R_NOTFOUND) {
                INSIST(!dns_rdataset_isassociated(&rdataset));
                return (ISC_R_SUCCESS);
        }
        if (result != ISC_R_SUCCESS) {
                INSIST(!dns_rdataset_isassociated(&rdataset));
                goto failure;
        }

        changed = ISC_FALSE;
        for (result = dns_rdataset_first(&rdataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(&rdataset)) {
                dns_rdata_t rdata = DNS_RDATA_INIT;

                dns_rdataset_current(&rdataset, &rdata);
                result = dns_rdata_tostruct(&rdata, &rrsig, NULL);
                RUNTIME_CHECK(result == ISC_R_SUCCESS);

                if (type != dns_rdatatype_dnskey) {
                        if (delsig_ok(&rrsig, keys, nkeys)) {
                                result = update_one_rr(db, ver, diff,
                                               DNS_DIFFOP_DELRESIGN, name,
                                               rdataset.ttl, &rdata);
                                if (incremental)
                                        changed = ISC_TRUE;
                                if (result != ISC_R_SUCCESS)
                                        break;
                        } else {
                                /*
                                 * At this point, we've got an RRSIG,
                                 * which is signed by an inactive key.
                                 * An administrator needs to provide a new
                                 * key/alg, but until that time, we want to
                                 * keep the old RRSIG.  Marking the key as
                                 * offline will prevent us spinning waiting
                                 * for the private part.
                                 */
                                if (incremental) {
                                        result = offline(db, ver, diff, name,
                                                         rdataset.ttl, &rdata);
                                        changed = ISC_TRUE;
                                        if (result != ISC_R_SUCCESS)
                                                break;
                                }

                                /*
                                 * Log the key id and algorithm of
                                 * the inactive key with no replacement
                                 */
                                if (zone->log_key_expired_timer <= now) {
                                        char origin[DNS_NAME_FORMATSIZE];
                                        char algbuf[DNS_NAME_FORMATSIZE];
                                        dns_name_format(&zone->origin, origin,
                                                        sizeof(origin));
                                        dns_secalg_format(rrsig.algorithm,
                                                          algbuf,
                                                          sizeof(algbuf));
                                        dns_zone_log(zone, ISC_LOG_WARNING,
                                                     "Key %s/%s/%d "
                                                     "missing or inactive "
                                                     "and has no replacement: "
                                                     "retaining signatures.",
                                                     origin, algbuf,
                                                     rrsig.keyid);
                                        zone->log_key_expired_timer = now +
                                                                        3600;
                                }
                        }
                        continue;
                }

                /*
                 * RRSIG(DNSKEY) requires special processing.
                 */
                found = ISC_FALSE;
                for (i = 0; i < nkeys; i++) {
                        if (rrsig.algorithm == dst_key_alg(keys[i]) &&
                            rrsig.keyid == dst_key_id(keys[i])) {
                                found = ISC_TRUE;
                                /*
                                 * Mark offline RRSIG(DNSKEY).
                                 * We want the earliest offline expire time
                                 * iff there is a new offline signature.
                                 */
                                if (!dst_key_isprivate(keys[i])) {
                                        isc_int64_t timeexpire =
                                           dns_time64_from32(rrsig.timeexpire);
                                        if (warn != 0 && warn > timeexpire)
                                                warn = timeexpire;
                                        if (rdata.flags & DNS_RDATA_OFFLINE) {
                                                if (maybe == 0 ||
                                                    maybe > timeexpire)
                                                        maybe = timeexpire;
                                                break;
                                        }
                                        if (warn == 0)
                                                warn = maybe;
                                        if (warn == 0 || warn > timeexpire)
                                                warn = timeexpire;
                                        result = offline(db, ver, diff, name,
                                                         rdataset.ttl, &rdata);
                                        break;
                                }
                                result = update_one_rr(db, ver, diff,
                                                       DNS_DIFFOP_DELRESIGN,
                                                       name, rdataset.ttl,
                                                       &rdata);
                                break;
                        }
                }

                /*
                 * If there is not a matching DNSKEY then
                 * delete the RRSIG.
                 */
                if (!found)
                        result = update_one_rr(db, ver, diff,
                                               DNS_DIFFOP_DELRESIGN, name,
                                               rdataset.ttl, &rdata);
                if (result != ISC_R_SUCCESS)
                        break;
        }

        if (changed && (rdataset.attributes & DNS_RDATASETATTR_RESIGN) != 0)
                dns_db_resigned(db, &rdataset, ver);

        dns_rdataset_disassociate(&rdataset);
        if (result == ISC_R_NOMORE)
                result = ISC_R_SUCCESS;
        if (warn > 0) {
#if defined(STDTIME_ON_32BITS)
                isc_stdtime_t stdwarn = (isc_stdtime_t)warn;
                if (warn == stdwarn)
#endif
                        set_key_expiry_warning(zone, (isc_stdtime_t)warn, now);
#if defined(STDTIME_ON_32BITS)
                else
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "key expiry warning time out of range");
#endif
        }
 failure:
        if (node != NULL)
                dns_db_detachnode(db, &node);
        return (result);
}

static isc_result_t
add_sigs(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
         dns_rdatatype_t type, dns_diff_t *diff, dst_key_t **keys,
         unsigned int nkeys, isc_mem_t *mctx, isc_stdtime_t inception,
         isc_stdtime_t expire, isc_boolean_t check_ksk,
         isc_boolean_t keyset_kskonly)
{
        isc_result_t result;
        dns_dbnode_t *node = NULL;
        dns_rdataset_t rdataset;
        dns_rdata_t sig_rdata = DNS_RDATA_INIT;
        unsigned char data[1024]; /* XXX */
        isc_buffer_t buffer;
        unsigned int i, j;

        dns_rdataset_init(&rdataset);
        isc_buffer_init(&buffer, data, sizeof(data));

        if (type == dns_rdatatype_nsec3)
                result = dns_db_findnsec3node(db, name, ISC_FALSE, &node);
        else
                result = dns_db_findnode(db, name, ISC_FALSE, &node);
        if (result == ISC_R_NOTFOUND)
                return (ISC_R_SUCCESS);
        if (result != ISC_R_SUCCESS)
                goto failure;
        result = dns_db_findrdataset(db, node, ver, type, 0,
                                     (isc_stdtime_t) 0, &rdataset, NULL);
        dns_db_detachnode(db, &node);
        if (result == ISC_R_NOTFOUND) {
                INSIST(!dns_rdataset_isassociated(&rdataset));
                return (ISC_R_SUCCESS);
        }
        if (result != ISC_R_SUCCESS) {
                INSIST(!dns_rdataset_isassociated(&rdataset));
                goto failure;
        }

        for (i = 0; i < nkeys; i++) {
                isc_boolean_t both = ISC_FALSE;

                if (!dst_key_isprivate(keys[i]))
                        continue;

                if (check_ksk && !REVOKE(keys[i])) {
                        isc_boolean_t have_ksk, have_nonksk;
                        if (KSK(keys[i])) {
                                have_ksk = ISC_TRUE;
                                have_nonksk = ISC_FALSE;
                        } else {
                                have_ksk = ISC_FALSE;
                                have_nonksk = ISC_TRUE;
                        }
                        for (j = 0; j < nkeys; j++) {
                                if (j == i || ALG(keys[i]) != ALG(keys[j]))
                                        continue;
                                if (REVOKE(keys[j]))
                                        continue;
                                if (KSK(keys[j]))
                                        have_ksk = ISC_TRUE;
                                else
                                        have_nonksk = ISC_TRUE;
                                both = have_ksk && have_nonksk;
                                if (both)
                                        break;
                        }
                }
                if (both) {
                        if (type == dns_rdatatype_dnskey) {
                                if (!KSK(keys[i]) && keyset_kskonly)
                                        continue;
                        } else if (KSK(keys[i]))
                                continue;
                } else if (REVOKE(keys[i]) && type != dns_rdatatype_dnskey)
                                continue;

                /* Calculate the signature, creating a RRSIG RDATA. */
                isc_buffer_clear(&buffer);
                CHECK(dns_dnssec_sign(name, &rdataset, keys[i],
                                      &inception, &expire,
                                      mctx, &buffer, &sig_rdata));
                /* Update the database and journal with the RRSIG. */
                /* XXX inefficient - will cause dataset merging */
                CHECK(update_one_rr(db, ver, diff, DNS_DIFFOP_ADDRESIGN,
                                    name, rdataset.ttl, &sig_rdata));
                dns_rdata_reset(&sig_rdata);
                isc_buffer_init(&buffer, data, sizeof(data));
        }

 failure:
        if (dns_rdataset_isassociated(&rdataset))
                dns_rdataset_disassociate(&rdataset);
        if (node != NULL)
                dns_db_detachnode(db, &node);
        return (result);
}

static void
zone_resigninc(dns_zone_t *zone) {
        dns_db_t *db = NULL;
        dns_dbversion_t *version = NULL;
        dns_diff_t sig_diff;
        dns_fixedname_t fixed;
        dns_name_t *name;
        dns_rdataset_t rdataset;
        dns_rdatatype_t covers;
        dst_key_t *zone_keys[DNS_MAXZONEKEYS];
        isc_boolean_t check_ksk, keyset_kskonly = ISC_FALSE;
        isc_result_t result;
        isc_stdtime_t now, inception, soaexpire, expire, stop;
        isc_uint32_t jitter;
        unsigned int i;
        unsigned int nkeys = 0;
        unsigned int resign;

        dns_rdataset_init(&rdataset);
        dns_fixedname_init(&fixed);
        dns_diff_init(zone->mctx, &sig_diff);
        sig_diff.resign = zone->sigresigninginterval;

        /*
         * Updates are disabled.  Pause for 5 minutes.
         */
        if (zone->update_disabled) {
                result = ISC_R_FAILURE;
                goto failure;
        }

        ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
        dns_db_attach(zone->db, &db);
        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);

        result = dns_db_newversion(db, &version);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "zone_resigninc:dns_db_newversion -> %s",
                             dns_result_totext(result));
                goto failure;
        }

        result = find_zone_keys(zone, db, version, zone->mctx, DNS_MAXZONEKEYS,
                                zone_keys, &nkeys);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "zone_resigninc:find_zone_keys -> %s",
                             dns_result_totext(result));
                goto failure;
        }

        isc_stdtime_get(&now);
        inception = now - 3600; /* Allow for clock skew. */
        soaexpire = now + dns_zone_getsigvalidityinterval(zone);
        /*
         * Spread out signatures over time if they happen to be
         * clumped.  We don't do this for each add_sigs() call as
         * we still want some clustering to occur.
         */
        isc_random_get(&jitter);
        expire = soaexpire - jitter % 3600;
        stop = now + 5;

        check_ksk = DNS_ZONE_OPTION(zone, DNS_ZONEOPT_UPDATECHECKKSK);
        keyset_kskonly = DNS_ZONE_OPTION(zone, DNS_ZONEOPT_DNSKEYKSKONLY);

        name = dns_fixedname_name(&fixed);
        result = dns_db_getsigningtime(db, &rdataset, name);
        if (result != ISC_R_SUCCESS && result != ISC_R_NOTFOUND) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "zone_resigninc:dns_db_getsigningtime -> %s",
                             dns_result_totext(result));
        }

        i = 0;
        while (result == ISC_R_SUCCESS) {
                resign = rdataset.resign;
                covers = rdataset.covers;
                dns_rdataset_disassociate(&rdataset);

                /*
                 * Stop if we hit the SOA as that means we have walked the
                 * entire zone.  The SOA record should always be the most
                 * recent signature.
                 */
                /* XXXMPA increase number of RRsets signed pre call */
                if (covers == dns_rdatatype_soa || i++ > zone->signatures ||
                    resign > stop)
                        break;

                result = del_sigs(zone, db, version, name, covers, &sig_diff,
                                  zone_keys, nkeys, now, ISC_TRUE);
                if (result != ISC_R_SUCCESS) {
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "zone_resigninc:del_sigs -> %s",
                                     dns_result_totext(result));
                        break;
                }

                result = add_sigs(db, version, name, covers, &sig_diff,
                                  zone_keys, nkeys, zone->mctx, inception,
                                  expire, check_ksk, keyset_kskonly);
                if (result != ISC_R_SUCCESS) {
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "zone_resigninc:add_sigs -> %s",
                                     dns_result_totext(result));
                        break;
                }
                result  = dns_db_getsigningtime(db, &rdataset,
                                                dns_fixedname_name(&fixed));
                if (nkeys == 0 && result == ISC_R_NOTFOUND) {
                        result = ISC_R_SUCCESS;
                        break;
                }
                if (result != ISC_R_SUCCESS)
                        dns_zone_log(zone, ISC_LOG_ERROR,
                             "zone_resigninc:dns_db_getsigningtime -> %s",
                                     dns_result_totext(result));
        }

        if (result != ISC_R_NOMORE && result != ISC_R_SUCCESS)
                goto failure;

        result = del_sigs(zone, db, version, &zone->origin, dns_rdatatype_soa,
                          &sig_diff, zone_keys, nkeys, now, ISC_TRUE);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "zone_resigninc:del_sigs -> %s",
                             dns_result_totext(result));
                goto failure;
        }

        /*
         * Did we change anything in the zone?
         */
        if (ISC_LIST_EMPTY(sig_diff.tuples))
                goto failure;

        /* Increment SOA serial if we have made changes */
        result = increment_soa_serial(db, version, &sig_diff, zone->mctx);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "zone_resigninc:increment_soa_serial -> %s",
                             dns_result_totext(result));
                goto failure;
        }

        /*
         * Generate maximum life time signatures so that the above loop
         * termination is sensible.
         */
        result = add_sigs(db, version, &zone->origin, dns_rdatatype_soa,
                          &sig_diff, zone_keys, nkeys, zone->mctx, inception,
                          soaexpire, check_ksk, keyset_kskonly);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "zone_resigninc:add_sigs -> %s",
                             dns_result_totext(result));
                goto failure;
        }

        /* Write changes to journal file. */
        CHECK(zone_journal(zone, &sig_diff, "zone_resigninc"));

        /* Everything has succeeded. Commit the changes. */
        dns_db_closeversion(db, &version, ISC_TRUE);

 failure:
        dns_diff_clear(&sig_diff);
        for (i = 0; i < nkeys; i++)
                dst_key_free(&zone_keys[i]);
        if (version != NULL) {
                dns_db_closeversion(zone->db, &version, ISC_FALSE);
                dns_db_detach(&db);
        } else if (db != NULL)
                dns_db_detach(&db);
        if (result == ISC_R_SUCCESS) {
                set_resigntime(zone);
                LOCK_ZONE(zone);
                zone_needdump(zone, DNS_DUMP_DELAY);
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDNOTIFY);
                UNLOCK_ZONE(zone);
        } else {
                /*
                 * Something failed.  Retry in 5 minutes.
                 */
                isc_interval_t ival;
                isc_interval_set(&ival, 300, 0);
                isc_time_nowplusinterval(&zone->resigntime, &ival);
        }
}

static isc_result_t
next_active(dns_db_t *db, dns_dbversion_t *version, dns_name_t *oldname,
            dns_name_t *newname, isc_boolean_t bottom)
{
        isc_result_t result;
        dns_dbiterator_t *dbit = NULL;
        dns_rdatasetiter_t *rdsit = NULL;
        dns_dbnode_t *node = NULL;

        CHECK(dns_db_createiterator(db, DNS_DB_NONSEC3, &dbit));
        CHECK(dns_dbiterator_seek(dbit, oldname));
        do {
                result = dns_dbiterator_next(dbit);
                if (result == ISC_R_NOMORE)
                        CHECK(dns_dbiterator_first(dbit));
                CHECK(dns_dbiterator_current(dbit, &node, newname));
                if (bottom && dns_name_issubdomain(newname, oldname) &&
                    !dns_name_equal(newname, oldname)) {
                        dns_db_detachnode(db, &node);
                        continue;
                }
                /*
                 * Is this node empty?
                 */
                CHECK(dns_db_allrdatasets(db, node, version, 0, &rdsit));
                result = dns_rdatasetiter_first(rdsit);
                dns_db_detachnode(db, &node);
                dns_rdatasetiter_destroy(&rdsit);
                if (result != ISC_R_NOMORE)
                        break;
        } while (1);
 failure:
        if (node != NULL)
                dns_db_detachnode(db, &node);
        if (dbit != NULL)
                dns_dbiterator_destroy(&dbit);
        return (result);
}

static isc_boolean_t
signed_with_key(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
                dns_rdatatype_t type, dst_key_t *key)
{
        isc_result_t result;
        dns_rdataset_t rdataset;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_rdata_rrsig_t rrsig;

        dns_rdataset_init(&rdataset);
        result = dns_db_findrdataset(db, node, version, dns_rdatatype_rrsig,
                                     type, 0, &rdataset, NULL);
        if (result != ISC_R_SUCCESS) {
                INSIST(!dns_rdataset_isassociated(&rdataset));
                return (ISC_FALSE);
        }
        for (result = dns_rdataset_first(&rdataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(&rdataset)) {
                dns_rdataset_current(&rdataset, &rdata);
                result = dns_rdata_tostruct(&rdata, &rrsig, NULL);
                INSIST(result == ISC_R_SUCCESS);
                if (rrsig.algorithm == dst_key_alg(key) &&
                    rrsig.keyid == dst_key_id(key)) {
                        dns_rdataset_disassociate(&rdataset);
                        return (ISC_TRUE);
                }
                dns_rdata_reset(&rdata);
        }
        dns_rdataset_disassociate(&rdataset);
        return (ISC_FALSE);
}

static isc_result_t
add_nsec(dns_db_t *db, dns_dbversion_t *version, dns_name_t *name,
         dns_dbnode_t *node, dns_ttl_t ttl, isc_boolean_t bottom,
         dns_diff_t *diff)
{
        dns_fixedname_t fixed;
        dns_name_t *next;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        isc_result_t result;
        unsigned char nsecbuffer[DNS_NSEC_BUFFERSIZE];

        dns_fixedname_init(&fixed);
        next = dns_fixedname_name(&fixed);

        CHECK(next_active(db, version, name, next, bottom));
        CHECK(dns_nsec_buildrdata(db, version, node, next, nsecbuffer,
                                  &rdata));
        CHECK(update_one_rr(db, version, diff, DNS_DIFFOP_ADD, name, ttl,
                            &rdata));
 failure:
        return (result);
}

static isc_result_t
sign_a_node(dns_db_t *db, dns_name_t *name, dns_dbnode_t *node,
            dns_dbversion_t *version, isc_boolean_t build_nsec3,
            isc_boolean_t build_nsec, dst_key_t *key,
            isc_stdtime_t inception, isc_stdtime_t expire,
            unsigned int minimum, isc_boolean_t is_ksk,
            isc_boolean_t keyset_kskonly, isc_boolean_t *delegation,
            dns_diff_t *diff, isc_int32_t *signatures, isc_mem_t *mctx)
{
        isc_result_t result;
        dns_rdatasetiter_t *iterator = NULL;
        dns_rdataset_t rdataset;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        isc_buffer_t buffer;
        unsigned char data[1024];
        isc_boolean_t seen_soa, seen_ns, seen_rr, seen_dname, seen_nsec,
                      seen_nsec3, seen_ds;
        isc_boolean_t bottom;

        result = dns_db_allrdatasets(db, node, version, 0, &iterator);
        if (result != ISC_R_SUCCESS) {
                if (result == ISC_R_NOTFOUND)
                        result = ISC_R_SUCCESS;
                return (result);
        }

        dns_rdataset_init(&rdataset);
        isc_buffer_init(&buffer, data, sizeof(data));
        seen_rr = seen_soa = seen_ns = seen_dname = seen_nsec =
        seen_nsec3 = seen_ds = ISC_FALSE;
        for (result = dns_rdatasetiter_first(iterator);
             result == ISC_R_SUCCESS;
             result = dns_rdatasetiter_next(iterator)) {
                dns_rdatasetiter_current(iterator, &rdataset);
                if (rdataset.type == dns_rdatatype_soa)
                        seen_soa = ISC_TRUE;
                else if (rdataset.type == dns_rdatatype_ns)
                        seen_ns = ISC_TRUE;
                else if (rdataset.type == dns_rdatatype_ds)
                        seen_ds = ISC_TRUE;
                else if (rdataset.type == dns_rdatatype_dname)
                        seen_dname = ISC_TRUE;
                else if (rdataset.type == dns_rdatatype_nsec)
                        seen_nsec = ISC_TRUE;
                else if (rdataset.type == dns_rdatatype_nsec3)
                        seen_nsec3 = ISC_TRUE;
                if (rdataset.type != dns_rdatatype_rrsig)
                        seen_rr = ISC_TRUE;
                dns_rdataset_disassociate(&rdataset);
        }
        if (result != ISC_R_NOMORE)
                goto failure;
        if (seen_ns && !seen_soa)
                *delegation = ISC_TRUE;
        /*
         * Going from insecure to NSEC3.
         * Don't generate NSEC3 records for NSEC3 records.
         */
        if (build_nsec3 && !seen_nsec3 && seen_rr) {
                isc_boolean_t unsecure = !seen_ds && seen_ns && !seen_soa;
                CHECK(dns_nsec3_addnsec3s(db, version, name, minimum,
                                          unsecure, diff));
                (*signatures)--;
        }
        /*
         * Going from insecure to NSEC.
         * Don't generate NSEC records for NSEC3 records.
         */
        if (build_nsec && !seen_nsec3 && !seen_nsec && seen_rr) {
                /* Build and add NSEC. */
                bottom = (seen_ns && !seen_soa) || seen_dname;
                /*
                 * Build a NSEC record except at the origin.
                 */
                if (!dns_name_equal(name, dns_db_origin(db))) {
                        CHECK(add_nsec(db, version, name, node, minimum,
                                       bottom, diff));
                        /* Count a NSEC generation as a signature generation. */
                        (*signatures)--;
                }
        }
        result = dns_rdatasetiter_first(iterator);
        while (result == ISC_R_SUCCESS) {
                dns_rdatasetiter_current(iterator, &rdataset);
                if (rdataset.type == dns_rdatatype_soa ||
                    rdataset.type == dns_rdatatype_rrsig)
                        goto next_rdataset;
                if (rdataset.type == dns_rdatatype_dnskey) {
                        if (!is_ksk && keyset_kskonly)
                                goto next_rdataset;
                } else if (is_ksk)
                        goto next_rdataset;
                if (*delegation &&
                    rdataset.type != dns_rdatatype_ds &&
                    rdataset.type != dns_rdatatype_nsec)
                        goto next_rdataset;
                if (signed_with_key(db, node, version, rdataset.type, key))
                        goto next_rdataset;
                /* Calculate the signature, creating a RRSIG RDATA. */
                isc_buffer_clear(&buffer);
                CHECK(dns_dnssec_sign(name, &rdataset, key, &inception,
                                      &expire, mctx, &buffer, &rdata));
                /* Update the database and journal with the RRSIG. */
                /* XXX inefficient - will cause dataset merging */
                CHECK(update_one_rr(db, version, diff, DNS_DIFFOP_ADDRESIGN,
                                    name, rdataset.ttl, &rdata));
                dns_rdata_reset(&rdata);
                (*signatures)--;
 next_rdataset:
                dns_rdataset_disassociate(&rdataset);
                result = dns_rdatasetiter_next(iterator);
        }
        if (result == ISC_R_NOMORE)
                result = ISC_R_SUCCESS;
        if (seen_dname)
                *delegation = ISC_TRUE;
 failure:
        if (dns_rdataset_isassociated(&rdataset))
                dns_rdataset_disassociate(&rdataset);
        if (iterator != NULL)
                dns_rdatasetiter_destroy(&iterator);
        return (result);
}

/*
 * If 'update_only' is set then don't create a NSEC RRset if it doesn't exist.
 */
static isc_result_t
updatesecure(dns_db_t *db, dns_dbversion_t *version, dns_name_t *name,
             dns_ttl_t minimum, isc_boolean_t update_only, dns_diff_t *diff)
{
        isc_result_t result;
        dns_rdataset_t rdataset;
        dns_dbnode_t *node = NULL;

        CHECK(dns_db_getoriginnode(db, &node));
        if (update_only) {
                dns_rdataset_init(&rdataset);
                result = dns_db_findrdataset(db, node, version,
                                             dns_rdatatype_nsec,
                                             dns_rdatatype_none,
                                             0, &rdataset, NULL);
                if (dns_rdataset_isassociated(&rdataset))
                        dns_rdataset_disassociate(&rdataset);
                if (result == ISC_R_NOTFOUND)
                        goto success;
                if (result != ISC_R_SUCCESS)
                        goto failure;
        }
        CHECK(delete_nsec(db, version, node, name, diff));
        CHECK(add_nsec(db, version, name, node, minimum, ISC_FALSE, diff));
 success:
        result = ISC_R_SUCCESS;
 failure:
        if (node != NULL)
                dns_db_detachnode(db, &node);
        return (result);
}

static isc_result_t
updatesignwithkey(dns_zone_t *zone, dns_signing_t *signing,
                  dns_dbversion_t *version, isc_boolean_t build_nsec3,
                  dns_ttl_t minimum, dns_diff_t *diff)
{
        isc_result_t result;
        dns_dbnode_t *node = NULL;
        dns_rdataset_t rdataset;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        unsigned char data[5];
        isc_boolean_t seen_done = ISC_FALSE;
        isc_boolean_t have_rr = ISC_FALSE;

        dns_rdataset_init(&rdataset);
        result = dns_db_getoriginnode(signing->db, &node);
        if (result != ISC_R_SUCCESS)
                goto failure;

        result = dns_db_findrdataset(signing->db, node, version,
                                     zone->privatetype, dns_rdatatype_none,
                                     0, &rdataset, NULL);
        if (result == ISC_R_NOTFOUND) {
                INSIST(!dns_rdataset_isassociated(&rdataset));
                result = ISC_R_SUCCESS;
                goto failure;
        }
        if (result != ISC_R_SUCCESS) {
                INSIST(!dns_rdataset_isassociated(&rdataset));
                goto failure;
        }
        for (result = dns_rdataset_first(&rdataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(&rdataset)) {
                dns_rdataset_current(&rdataset, &rdata);
                /*
                 * If we don't match the algorithm or keyid skip the record.
                 */
                if (rdata.length != 5 ||
                    rdata.data[0] != signing->algorithm ||
                    rdata.data[1] != ((signing->keyid >> 8) & 0xff) ||
                    rdata.data[2] != (signing->keyid & 0xff)) {
                        have_rr = ISC_TRUE;
                        dns_rdata_reset(&rdata);
                        continue;
                }
                /*
                 * We have a match.  If we were signing (!signing->delete)
                 * and we already have a record indicating that we have
                 * finished signing (rdata.data[4] != 0) then keep it.
                 * Otherwise it needs to be deleted as we have removed all
                 * the signatures (signing->delete), so any record indicating
                 * completion is now out of date, or we have finished signing
                 * with the new record so we no longer need to remember that
                 * we need to sign the zone with the matching key across a
                 * nameserver re-start.
                 */
                if (!signing->delete && rdata.data[4] != 0) {
                        seen_done = ISC_TRUE;
                        have_rr = ISC_TRUE;
                } else
                        CHECK(update_one_rr(signing->db, version, diff,
                                            DNS_DIFFOP_DEL, &zone->origin,
                                            rdataset.ttl, &rdata));
                dns_rdata_reset(&rdata);
        }
        if (result == ISC_R_NOMORE)
                result = ISC_R_SUCCESS;
        if (!signing->delete && !seen_done) {
                /*
                 * If we were signing then we need to indicate that we have
                 * finished signing the zone with this key.  If it is already
                 * there we don't need to add it a second time.
                 */
                data[0] = signing->algorithm;
                data[1] = (signing->keyid >> 8) & 0xff;
                data[2] = signing->keyid & 0xff;
                data[3] = 0;
                data[4] = 1;
                rdata.length = sizeof(data);
                rdata.data = data;
                rdata.type = zone->privatetype;
                rdata.rdclass = dns_db_class(signing->db);
                CHECK(update_one_rr(signing->db, version, diff, DNS_DIFFOP_ADD,
                                    &zone->origin, rdataset.ttl, &rdata));
        } else if (!have_rr) {
                dns_name_t *origin = dns_db_origin(signing->db);
                /*
                 * Rebuild the NSEC/NSEC3 record for the origin as we no
                 * longer have any private records.
                 */
                if (build_nsec3)
                        CHECK(dns_nsec3_addnsec3s(signing->db, version, origin,
                                                  minimum, ISC_FALSE, diff));
                CHECK(updatesecure(signing->db, version, origin, minimum,
                                   ISC_TRUE, diff));
        }

 failure:
        if (dns_rdataset_isassociated(&rdataset))
                dns_rdataset_disassociate(&rdataset);
        if (node != NULL)
                dns_db_detachnode(signing->db, &node);
        return (result);
}

/*
 * If 'active' is set then we are not done with the chain yet so only
 * delete the nsec3param record which indicates a full chain exists
 * (flags == 0).
 */
static isc_result_t
fixup_nsec3param(dns_db_t *db, dns_dbversion_t *ver, dns_nsec3chain_t *chain,
                 isc_boolean_t active, dns_rdatatype_t privatetype,
                 dns_diff_t *diff)
{
        dns_dbnode_t *node = NULL;
        dns_name_t *name = dns_db_origin(db);
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_rdataset_t rdataset;
        dns_rdata_nsec3param_t nsec3param;
        isc_result_t result;
        isc_buffer_t buffer;
        unsigned char parambuf[DNS_NSEC3PARAM_BUFFERSIZE];
        dns_ttl_t ttl = 0;

        dns_rdataset_init(&rdataset);

        result = dns_db_getoriginnode(db, &node);
        RUNTIME_CHECK(result == ISC_R_SUCCESS);
        result = dns_db_findrdataset(db, node, ver, dns_rdatatype_nsec3param,
                                     0, 0, &rdataset, NULL);
        if (result == ISC_R_NOTFOUND)
                goto try_private;
        if (result != ISC_R_SUCCESS)
                goto failure;

        /*
         * Preserve the existing ttl.
         */
        ttl = rdataset.ttl;

        /*
         * Delete all NSEC3PARAM records which match that in nsec3chain.
         */
        for (result = dns_rdataset_first(&rdataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(&rdataset)) {

                dns_rdataset_current(&rdataset, &rdata);
                CHECK(dns_rdata_tostruct(&rdata, &nsec3param, NULL));

                if (nsec3param.hash != chain->nsec3param.hash ||
                    (active && nsec3param.flags != 0) ||
                    nsec3param.iterations != chain->nsec3param.iterations ||
                    nsec3param.salt_length != chain->nsec3param.salt_length ||
                    memcmp(nsec3param.salt, chain->nsec3param.salt,
                           nsec3param.salt_length)) {
                        dns_rdata_reset(&rdata);
                        continue;
                }

                CHECK(update_one_rr(db, ver, diff, DNS_DIFFOP_DEL,
                                    name, rdataset.ttl, &rdata));
                dns_rdata_reset(&rdata);
        }
        if (result != ISC_R_NOMORE)
                goto failure;

        dns_rdataset_disassociate(&rdataset);

 try_private:

        if (active)
                goto add;
        /*
         * Delete all private records which match that in nsec3chain.
         */
        result = dns_db_findrdataset(db, node, ver, privatetype,
                                     0, 0, &rdataset, NULL);
        if (result == ISC_R_NOTFOUND)
                goto add;
        if (result != ISC_R_SUCCESS)
                goto failure;

        for (result = dns_rdataset_first(&rdataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(&rdataset)) {
                dns_rdata_t private = DNS_RDATA_INIT;
                unsigned char buf[DNS_NSEC3PARAM_BUFFERSIZE];

                dns_rdataset_current(&rdataset, &private);
                if (!dns_nsec3param_fromprivate(&private, &rdata,
                                                buf, sizeof(buf)))
                        continue;
                CHECK(dns_rdata_tostruct(&rdata, &nsec3param, NULL));

                if (nsec3param.hash != chain->nsec3param.hash ||
                    nsec3param.iterations != chain->nsec3param.iterations ||
                    nsec3param.salt_length != chain->nsec3param.salt_length ||
                    memcmp(nsec3param.salt, chain->nsec3param.salt,
                           nsec3param.salt_length)) {
                        dns_rdata_reset(&rdata);
                        continue;
                }

                CHECK(update_one_rr(db, ver, diff, DNS_DIFFOP_DEL,
                                    name, rdataset.ttl, &private));
                dns_rdata_reset(&rdata);
        }
        if (result != ISC_R_NOMORE)
                goto failure;

  add:
        if ((chain->nsec3param.flags & DNS_NSEC3FLAG_REMOVE) != 0) {
                result = ISC_R_SUCCESS;
                goto failure;
        }

        /*
         * Add a NSEC3PARAM record which matches that in nsec3chain but
         * with all flags bits cleared.
         *
         * Note: we do not clear chain->nsec3param.flags as this change
         * may be reversed.
         */
        isc_buffer_init(&buffer, &parambuf, sizeof(parambuf));
        CHECK(dns_rdata_fromstruct(&rdata, dns_db_class(db),
                                   dns_rdatatype_nsec3param,
                                   &chain->nsec3param, &buffer));
        rdata.data[1] = 0;      /* Clear flag bits. */
        CHECK(update_one_rr(db, ver, diff, DNS_DIFFOP_ADD, name, ttl, &rdata));

  failure:
        dns_db_detachnode(db, &node);
        if (dns_rdataset_isassociated(&rdataset))
                dns_rdataset_disassociate(&rdataset);
        return (result);
}

static isc_result_t
delete_nsec(dns_db_t *db, dns_dbversion_t *ver, dns_dbnode_t *node,
            dns_name_t *name, dns_diff_t *diff)
{
        dns_rdataset_t rdataset;
        isc_result_t result;

        dns_rdataset_init(&rdataset);

        result = dns_db_findrdataset(db, node, ver, dns_rdatatype_nsec,
                                     0, 0, &rdataset, NULL);
        if (result == ISC_R_NOTFOUND)
                return (ISC_R_SUCCESS);
        if (result != ISC_R_SUCCESS)
                return (result);
        for (result = dns_rdataset_first(&rdataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(&rdataset)) {
                dns_rdata_t rdata = DNS_RDATA_INIT;

                dns_rdataset_current(&rdataset, &rdata);
                CHECK(update_one_rr(db, ver, diff, DNS_DIFFOP_DEL, name,
                                    rdataset.ttl, &rdata));
        }
        if (result == ISC_R_NOMORE)
                result = ISC_R_SUCCESS;
 failure:
        dns_rdataset_disassociate(&rdataset);
        return (result);
}

static isc_result_t
deletematchingnsec3(dns_db_t *db, dns_dbversion_t *ver, dns_dbnode_t *node,
                    dns_name_t *name, const dns_rdata_nsec3param_t *param,
                    dns_diff_t *diff)
{
        dns_rdataset_t rdataset;
        dns_rdata_nsec3_t nsec3;
        isc_result_t result;

        dns_rdataset_init(&rdataset);
        result = dns_db_findrdataset(db, node, ver, dns_rdatatype_nsec3,
                                     0, 0, &rdataset, NULL);
        if (result == ISC_R_NOTFOUND)
                return (ISC_R_SUCCESS);
        if (result != ISC_R_SUCCESS)
                return (result);

        for (result = dns_rdataset_first(&rdataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(&rdataset)) {
                dns_rdata_t rdata = DNS_RDATA_INIT;

                dns_rdataset_current(&rdataset, &rdata);
                CHECK(dns_rdata_tostruct(&rdata, &nsec3, NULL));
                if (nsec3.hash != param->hash ||
                    nsec3.iterations != param->iterations ||
                    nsec3.salt_length != param->salt_length ||
                    memcmp(nsec3.salt, param->salt, nsec3.salt_length))
                        continue;
                CHECK(update_one_rr(db, ver, diff, DNS_DIFFOP_DEL, name,
                                    rdataset.ttl, &rdata));
        }
        if (result == ISC_R_NOMORE)
                result = ISC_R_SUCCESS;
 failure:
        dns_rdataset_disassociate(&rdataset);
        return (result);
}

static isc_result_t
need_nsec_chain(dns_db_t *db, dns_dbversion_t *ver,
                const dns_rdata_nsec3param_t *param,
                isc_boolean_t *answer)
{
        dns_dbnode_t *node = NULL;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_rdata_nsec3param_t myparam;
        dns_rdataset_t rdataset;
        isc_result_t result;

        *answer = ISC_FALSE;

        result = dns_db_getoriginnode(db, &node);
        RUNTIME_CHECK(result == ISC_R_SUCCESS);

        dns_rdataset_init(&rdataset);

        result = dns_db_findrdataset(db, node, ver, dns_rdatatype_nsec,
                                     0, 0, &rdataset, NULL);
        if (result == ISC_R_SUCCESS) {
                dns_rdataset_disassociate(&rdataset);
                dns_db_detachnode(db, &node);
                return (result);
        }
        if (result != ISC_R_NOTFOUND) {
                dns_db_detachnode(db, &node);
                return (result);
        }

        result = dns_db_findrdataset(db, node, ver, dns_rdatatype_nsec3param,
                                     0, 0, &rdataset, NULL);
        if (result == ISC_R_NOTFOUND) {
                *answer = ISC_TRUE;
                dns_db_detachnode(db, &node);
                return (ISC_R_SUCCESS);
        }
        if (result != ISC_R_SUCCESS) {
                dns_db_detachnode(db, &node);
                return (result);
        }

        for (result = dns_rdataset_first(&rdataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(&rdataset)) {
                dns_rdataset_current(&rdataset, &rdata);
                CHECK(dns_rdata_tostruct(&rdata, &myparam, NULL));
                dns_rdata_reset(&rdata);
                /*
                 * Ignore any NSEC3PARAM removals.
                 */
                if (NSEC3REMOVE(myparam.flags))
                        continue;
                /*
                 * Ignore the chain that we are in the process of deleting.
                 */
                if (myparam.hash == param->hash &&
                    myparam.iterations == param->iterations &&
                    myparam.salt_length == param->salt_length &&
                    !memcmp(myparam.salt, param->salt, myparam.salt_length))
                        continue;
                /*
                 * Found an active NSEC3 chain.
                 */
                break;
        }
        if (result == ISC_R_NOMORE) {
                *answer = ISC_TRUE;
                result = ISC_R_SUCCESS;
        }

 failure:
        if (dns_rdataset_isassociated(&rdataset))
                dns_rdataset_disassociate(&rdataset);
        dns_db_detachnode(db, &node);
        return (result);
}

static isc_result_t
update_sigs(dns_diff_t *diff, dns_db_t *db, dns_dbversion_t *version,
            dst_key_t *zone_keys[], unsigned int nkeys, dns_zone_t *zone,
            isc_stdtime_t inception, isc_stdtime_t expire, isc_stdtime_t now,
            isc_boolean_t check_ksk, isc_boolean_t keyset_kskonly,
            dns_diff_t *sig_diff)
{
        dns_difftuple_t *tuple;
        isc_result_t result;

        for (tuple = ISC_LIST_HEAD(diff->tuples);
             tuple != NULL;
             tuple = ISC_LIST_HEAD(diff->tuples)) {
                result = del_sigs(zone, db, version, &tuple->name,
                                  tuple->rdata.type, sig_diff,
                                  zone_keys, nkeys, now, ISC_FALSE);
                if (result != ISC_R_SUCCESS) {
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "update_sigs:del_sigs -> %s",
                                     dns_result_totext(result));
                        return (result);
                }
                result = add_sigs(db, version, &tuple->name,
                                  tuple->rdata.type, sig_diff,
                                  zone_keys, nkeys, zone->mctx, inception,
                                  expire, check_ksk, keyset_kskonly);
                if (result != ISC_R_SUCCESS) {
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "update_sigs:add_sigs -> %s",
                                     dns_result_totext(result));
                        return (result);
                }

                do {
                        dns_difftuple_t *next = ISC_LIST_NEXT(tuple, link);
                        while (next != NULL &&
                               (tuple->rdata.type != next->rdata.type ||
                                !dns_name_equal(&tuple->name, &next->name)))
                                next = ISC_LIST_NEXT(next, link);
                        ISC_LIST_UNLINK(diff->tuples, tuple, link);
                        dns_diff_appendminimal(sig_diff, &tuple);
                        INSIST(tuple == NULL);
                        tuple = next;
                } while (tuple != NULL);
        }
        return (ISC_R_SUCCESS);
}

/*
 * Incrementally build and sign a new NSEC3 chain using the parameters
 * requested.
 */
static void
zone_nsec3chain(dns_zone_t *zone) {
        dns_db_t *db = NULL;
        dns_dbnode_t *node = NULL;
        dns_dbversion_t *version = NULL;
        dns_diff_t sig_diff;
        dns_diff_t nsec_diff;
        dns_diff_t nsec3_diff;
        dns_diff_t param_diff;
        dns_fixedname_t fixed;
        dns_fixedname_t nextfixed;
        dns_name_t *name, *nextname;
        dns_rdataset_t rdataset;
        dns_nsec3chain_t *nsec3chain = NULL, *nextnsec3chain;
        dns_nsec3chainlist_t cleanup;
        dst_key_t *zone_keys[DNS_MAXZONEKEYS];
        isc_int32_t signatures;
        isc_boolean_t check_ksk, keyset_kskonly;
        isc_boolean_t delegation;
        isc_boolean_t first;
        isc_result_t result;
        isc_stdtime_t now, inception, soaexpire, expire;
        isc_uint32_t jitter;
        unsigned int i;
        unsigned int nkeys = 0;
        isc_uint32_t nodes;
        isc_boolean_t unsecure = ISC_FALSE;
        isc_boolean_t seen_soa, seen_ns, seen_dname, seen_ds;
        isc_boolean_t seen_nsec, seen_nsec3, seen_rr;
        dns_rdatasetiter_t *iterator = NULL;
        isc_boolean_t buildnsecchain;
        isc_boolean_t updatensec = ISC_FALSE;
        dns_rdatatype_t privatetype = zone->privatetype;

        dns_rdataset_init(&rdataset);
        dns_fixedname_init(&fixed);
        name = dns_fixedname_name(&fixed);
        dns_fixedname_init(&nextfixed);
        nextname = dns_fixedname_name(&nextfixed);
        dns_diff_init(zone->mctx, &param_diff);
        dns_diff_init(zone->mctx, &nsec3_diff);
        dns_diff_init(zone->mctx, &nsec_diff);
        dns_diff_init(zone->mctx, &sig_diff);
        sig_diff.resign = zone->sigresigninginterval;
        ISC_LIST_INIT(cleanup);

        /*
         * Updates are disabled.  Pause for 5 minutes.
         */
        if (zone->update_disabled) {
                result = ISC_R_FAILURE;
                goto failure;
        }

        ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
        dns_db_attach(zone->db, &db);
        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);

        result = dns_db_newversion(db, &version);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "zone_nsec3chain:dns_db_newversion -> %s",
                             dns_result_totext(result));
                goto failure;
        }

        result = find_zone_keys(zone, db, version, zone->mctx,
                                DNS_MAXZONEKEYS, zone_keys, &nkeys);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "zone_nsec3chain:find_zone_keys -> %s",
                             dns_result_totext(result));
                goto failure;
        }

        isc_stdtime_get(&now);
        inception = now - 3600; /* Allow for clock skew. */
        soaexpire = now + dns_zone_getsigvalidityinterval(zone);

        /*
         * Spread out signatures over time if they happen to be
         * clumped.  We don't do this for each add_sigs() call as
         * we still want some clustering to occur.
         */
        isc_random_get(&jitter);
        expire = soaexpire - jitter % 3600;

        check_ksk = DNS_ZONE_OPTION(zone, DNS_ZONEOPT_UPDATECHECKKSK);
        keyset_kskonly = DNS_ZONE_OPTION(zone, DNS_ZONEOPT_DNSKEYKSKONLY);

        /*
         * We keep pulling nodes off each iterator in turn until
         * we have no more nodes to pull off or we reach the limits
         * for this quantum.
         */
        nodes = zone->nodes;
        signatures = zone->signatures;
        LOCK_ZONE(zone);
        nsec3chain = ISC_LIST_HEAD(zone->nsec3chain);
        UNLOCK_ZONE(zone);
        first = ISC_TRUE;

        if (nsec3chain != NULL)
                nsec3chain->save_delete_nsec = nsec3chain->delete_nsec;
        /*
         * Generate new NSEC3 chains first.
         */
        while (nsec3chain != NULL && nodes-- > 0 && signatures > 0) {
                LOCK_ZONE(zone);
                nextnsec3chain = ISC_LIST_NEXT(nsec3chain, link);

                ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
                if (nsec3chain->done || nsec3chain->db != zone->db) {
                        ISC_LIST_UNLINK(zone->nsec3chain, nsec3chain, link);
                        ISC_LIST_APPEND(cleanup, nsec3chain, link);
                }
                ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
                UNLOCK_ZONE(zone);
                if (ISC_LIST_TAIL(cleanup) == nsec3chain)
                        goto next_addchain;

                /*
                 * Possible future db.
                 */
                if (nsec3chain->db != db) {
                        goto next_addchain;
                }

                if (NSEC3REMOVE(nsec3chain->nsec3param.flags))
                        goto next_addchain;

                dns_dbiterator_current(nsec3chain->dbiterator, &node, name);

                if (nsec3chain->delete_nsec) {
                        delegation = ISC_FALSE;
                        dns_dbiterator_pause(nsec3chain->dbiterator);
                        CHECK(delete_nsec(db, version, node, name, &nsec_diff));
                        goto next_addnode;
                }
                /*
                 * On the first pass we need to check if the current node
                 * has not been obscured.
                 */
                delegation = ISC_FALSE;
                unsecure = ISC_FALSE;
                if (first) {
                        dns_fixedname_t ffound;
                        dns_name_t *found;
                        dns_fixedname_init(&ffound);
                        found = dns_fixedname_name(&ffound);
                        result = dns_db_find(db, name, version,
                                             dns_rdatatype_soa,
                                             DNS_DBFIND_NOWILD, 0, NULL, found,
                                             NULL, NULL);
                        if ((result == DNS_R_DELEGATION ||
                            result == DNS_R_DNAME) &&
                            !dns_name_equal(name, found)) {
                                /*
                                 * Remember the obscuring name so that
                                 * we skip all obscured names.
                                 */
                                dns_name_copy(found, name, NULL);
                                delegation = ISC_TRUE;
                                goto next_addnode;
                        }
                }

                /*
                 * Check to see if this is a bottom of zone node.
                 */
                result = dns_db_allrdatasets(db, node, version, 0, &iterator);
                if (result == ISC_R_NOTFOUND)   /* Empty node? */
                        goto next_addnode;
                if (result != ISC_R_SUCCESS)
                        goto failure;

                seen_soa = seen_ns = seen_dname = seen_ds = seen_nsec =
                        ISC_FALSE;
                for (result = dns_rdatasetiter_first(iterator);
                     result == ISC_R_SUCCESS;
                     result = dns_rdatasetiter_next(iterator)) {
                        dns_rdatasetiter_current(iterator, &rdataset);
                        INSIST(rdataset.type != dns_rdatatype_nsec3);
                        if (rdataset.type == dns_rdatatype_soa)
                                seen_soa = ISC_TRUE;
                        else if (rdataset.type == dns_rdatatype_ns)
                                seen_ns = ISC_TRUE;
                        else if (rdataset.type == dns_rdatatype_dname)
                                seen_dname = ISC_TRUE;
                        else if (rdataset.type == dns_rdatatype_ds)
                                seen_ds = ISC_TRUE;
                        else if (rdataset.type == dns_rdatatype_nsec)
                                seen_nsec = ISC_TRUE;
                        dns_rdataset_disassociate(&rdataset);
                }
                dns_rdatasetiter_destroy(&iterator);
                /*
                 * Is there a NSEC chain than needs to be cleaned up?
                 */
                if (seen_nsec)
                        nsec3chain->seen_nsec = ISC_TRUE;
                if (seen_ns && !seen_soa && !seen_ds)
                        unsecure = ISC_TRUE;
                if ((seen_ns && !seen_soa) || seen_dname)
                        delegation = ISC_TRUE;

                /*
                 * Process one node.
                 */
                dns_dbiterator_pause(nsec3chain->dbiterator);
                result = dns_nsec3_addnsec3(db, version, name,
                                            &nsec3chain->nsec3param,
                                            zone->minimum, unsecure,
                                            &nsec3_diff);
                if (result != ISC_R_SUCCESS) {
                        dns_zone_log(zone, ISC_LOG_ERROR, "zone_nsec3chain:"
                                     "dns_nsec3_addnsec3 -> %s",
                                     dns_result_totext(result));
                        goto failure;
                }

                /*
                 * Treat each call to dns_nsec3_addnsec3() as if it's cost is
                 * two signatures.  Additionally there will, in general, be
                 * two signature generated below.
                 *
                 * If we are only changing the optout flag the cost is half
                 * that of the cost of generating a completely new chain.
                 */
                signatures -= 4;

                /*
                 * Go onto next node.
                 */
 next_addnode:
                first = ISC_FALSE;
                dns_db_detachnode(db, &node);
                do {
                        result = dns_dbiterator_next(nsec3chain->dbiterator);

                        if (result == ISC_R_NOMORE && nsec3chain->delete_nsec) {
                                CHECK(fixup_nsec3param(db, version, nsec3chain,
                                                       ISC_FALSE, privatetype,
                                                       &param_diff));
                                LOCK_ZONE(zone);
                                ISC_LIST_UNLINK(zone->nsec3chain, nsec3chain,
                                                link);
                                UNLOCK_ZONE(zone);
                                ISC_LIST_APPEND(cleanup, nsec3chain, link);
                                goto next_addchain;
                        }
                        if (result == ISC_R_NOMORE) {
                                dns_dbiterator_pause(nsec3chain->dbiterator);
                                if (nsec3chain->seen_nsec) {
                                        CHECK(fixup_nsec3param(db, version,
                                                               nsec3chain,
                                                               ISC_TRUE,
                                                               privatetype,
                                                               &param_diff));
                                        nsec3chain->delete_nsec = ISC_TRUE;
                                        goto same_addchain;
                                }
                                CHECK(fixup_nsec3param(db, version, nsec3chain,
                                                       ISC_FALSE, privatetype,
                                                       &param_diff));
                                LOCK_ZONE(zone);
                                ISC_LIST_UNLINK(zone->nsec3chain, nsec3chain,
                                                link);
                                UNLOCK_ZONE(zone);
                                ISC_LIST_APPEND(cleanup, nsec3chain, link);
                                goto next_addchain;
                        } else if (result != ISC_R_SUCCESS) {
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "zone_nsec3chain:"
                                             "dns_dbiterator_next -> %s",
                                             dns_result_totext(result));
                                goto failure;
                        } else if (delegation) {
                                dns_dbiterator_current(nsec3chain->dbiterator,
                                                       &node, nextname);
                                dns_db_detachnode(db, &node);
                                if (!dns_name_issubdomain(nextname, name))
                                        break;
                        } else
                                break;
                } while (1);
                continue;

 same_addchain:
                CHECK(dns_dbiterator_first(nsec3chain->dbiterator));
                first = ISC_TRUE;
                continue;

 next_addchain:
                dns_dbiterator_pause(nsec3chain->dbiterator);
                nsec3chain = nextnsec3chain;
                first = ISC_TRUE;
                if (nsec3chain != NULL)
                        nsec3chain->save_delete_nsec = nsec3chain->delete_nsec;
        }

        /*
         * Process removals.
         */
        LOCK_ZONE(zone);
        nsec3chain = ISC_LIST_HEAD(zone->nsec3chain);
        UNLOCK_ZONE(zone);
        first = ISC_TRUE;
        buildnsecchain = ISC_FALSE;
        while (nsec3chain != NULL && nodes-- > 0 && signatures > 0) {
                LOCK_ZONE(zone);
                nextnsec3chain = ISC_LIST_NEXT(nsec3chain, link);
                UNLOCK_ZONE(zone);

                if (nsec3chain->db != db)
                        goto next_removechain;

                if (!NSEC3REMOVE(nsec3chain->nsec3param.flags))
                        goto next_removechain;

                /*
                 * Work out if we need to build a NSEC chain as a consequence
                 * of removing this NSEC3 chain.
                 */
                if (first && !updatensec &&
                    (nsec3chain->nsec3param.flags & DNS_NSEC3FLAG_NONSEC) == 0) {
                        result = need_nsec_chain(db, version,
                                                 &nsec3chain->nsec3param,
                                                 &buildnsecchain);
                        if (result != ISC_R_SUCCESS) {
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "zone_nsec3chain:"
                                             "need_nsec_chain -> %s",
                                             dns_result_totext(result));
                                goto failure;
                        }
                }

                if (first)
                        dns_zone_log(zone, ISC_LOG_DEBUG(3), "zone_nsec3chain:"
                                     "buildnsecchain = %u\n", buildnsecchain);

                dns_dbiterator_current(nsec3chain->dbiterator, &node, name);
                delegation = ISC_FALSE;

                if (!buildnsecchain) {
                        /*
                         * Delete the NSECPARAM record that matches this chain.
                         */
                        if (first) {
                                result = fixup_nsec3param(db, version,
                                                          nsec3chain,
                                                          ISC_TRUE, privatetype,
                                                          &param_diff);
                                if (result != ISC_R_SUCCESS) {
                                        dns_zone_log(zone, ISC_LOG_ERROR,
                                                     "zone_nsec3chain:"
                                                     "fixup_nsec3param -> %s",
                                                     dns_result_totext(result));
                                        goto failure;
                                }
                        }

                        /*
                         *  Delete the NSEC3 records.
                         */
                        result = deletematchingnsec3(db, version, node, name,
                                                     &nsec3chain->nsec3param,
                                                     &nsec3_diff);
                        if (result != ISC_R_SUCCESS) {
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "zone_nsec3chain:"
                                             "deletematchingnsec3 -> %s",
                                             dns_result_totext(result));
                                goto failure;
                        }
                        goto next_removenode;
                }

                if (first) {
                        dns_fixedname_t ffound;
                        dns_name_t *found;
                        dns_fixedname_init(&ffound);
                        found = dns_fixedname_name(&ffound);
                        result = dns_db_find(db, name, version,
                                             dns_rdatatype_soa,
                                             DNS_DBFIND_NOWILD, 0, NULL, found,
                                             NULL, NULL);
                        if ((result == DNS_R_DELEGATION ||
                             result == DNS_R_DNAME) &&
                            !dns_name_equal(name, found)) {
                                /*
                                 * Remember the obscuring name so that
                                 * we skip all obscured names.
                                 */
                                dns_name_copy(found, name, NULL);
                                delegation = ISC_TRUE;
                                goto next_removenode;
                        }
                }

                /*
                 * Check to see if this is a bottom of zone node.
                 */
                result = dns_db_allrdatasets(db, node, version, 0, &iterator);
                if (result == ISC_R_NOTFOUND)   /* Empty node? */
                        goto next_removenode;
                if (result != ISC_R_SUCCESS)
                        goto failure;

                seen_soa = seen_ns = seen_dname = seen_nsec3 = seen_nsec =
                        seen_rr = ISC_FALSE;
                for (result = dns_rdatasetiter_first(iterator);
                     result == ISC_R_SUCCESS;
                     result = dns_rdatasetiter_next(iterator)) {
                        dns_rdatasetiter_current(iterator, &rdataset);
                        if (rdataset.type == dns_rdatatype_soa)
                                seen_soa = ISC_TRUE;
                        else if (rdataset.type == dns_rdatatype_ns)
                                seen_ns = ISC_TRUE;
                        else if (rdataset.type == dns_rdatatype_dname)
                                seen_dname = ISC_TRUE;
                        else if (rdataset.type == dns_rdatatype_nsec)
                                seen_nsec = ISC_TRUE;
                        else if (rdataset.type == dns_rdatatype_nsec3)
                                seen_nsec3 = ISC_TRUE;
                        if (rdataset.type != dns_rdatatype_rrsig)
                                seen_rr = ISC_TRUE;
                        dns_rdataset_disassociate(&rdataset);
                }
                dns_rdatasetiter_destroy(&iterator);

                if (!seen_rr || seen_nsec3 || seen_nsec)
                        goto next_removenode;
                if ((seen_ns && !seen_soa) || seen_dname)
                        delegation = ISC_TRUE;

                /*
                 * Add a NSEC record except at the origin.
                 */
                if (!dns_name_equal(name, dns_db_origin(db))) {
                        dns_dbiterator_pause(nsec3chain->dbiterator);
                        CHECK(add_nsec(db, version, name, node, zone->minimum,
                                       delegation, &nsec_diff));
                }

 next_removenode:
                first = ISC_FALSE;
                dns_db_detachnode(db, &node);
                do {
                        result = dns_dbiterator_next(nsec3chain->dbiterator);
                        if (result == ISC_R_NOMORE && buildnsecchain) {
                                /*
                                 * The NSEC chain should now be built.
                                 * We can now remove the NSEC3 chain.
                                 */
                                updatensec = ISC_TRUE;
                                goto same_removechain;
                        }
                        if (result == ISC_R_NOMORE) {
                                LOCK_ZONE(zone);
                                ISC_LIST_UNLINK(zone->nsec3chain, nsec3chain,
                                                link);
                                UNLOCK_ZONE(zone);
                                ISC_LIST_APPEND(cleanup, nsec3chain, link);
                                dns_dbiterator_pause(nsec3chain->dbiterator);
                                result = fixup_nsec3param(db, version,
                                                          nsec3chain, ISC_FALSE,
                                                          privatetype,
                                                          &param_diff);
                                if (result != ISC_R_SUCCESS) {
                                        dns_zone_log(zone, ISC_LOG_ERROR,
                                                     "zone_nsec3chain:"
                                                     "fixup_nsec3param -> %s",
                                                     dns_result_totext(result));
                                        goto failure;
                                }
                                goto next_removechain;
                        } else if (result != ISC_R_SUCCESS) {
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "zone_nsec3chain:"
                                             "dns_dbiterator_next -> %s",
                                             dns_result_totext(result));
                                goto failure;
                        } else if (delegation) {
                                dns_dbiterator_current(nsec3chain->dbiterator,
                                                       &node, nextname);
                                dns_db_detachnode(db, &node);
                                if (!dns_name_issubdomain(nextname, name))
                                        break;
                        } else
                                break;
                } while (1);
                continue;

 same_removechain:
                CHECK(dns_dbiterator_first(nsec3chain->dbiterator));
                buildnsecchain = ISC_FALSE;
                first = ISC_TRUE;
                continue;

 next_removechain:
                dns_dbiterator_pause(nsec3chain->dbiterator);
                nsec3chain = nextnsec3chain;
                first = ISC_TRUE;
        }

        /*
         * We may need to update the NSEC/NSEC3 records for the zone apex.
         */
        if (!ISC_LIST_EMPTY(param_diff.tuples)) {
                isc_boolean_t rebuild_nsec = ISC_FALSE,
                              rebuild_nsec3 = ISC_FALSE;
                result = dns_db_getoriginnode(db, &node);
                RUNTIME_CHECK(result == ISC_R_SUCCESS);
                result = dns_db_allrdatasets(db, node, version, 0, &iterator);
                if (result != ISC_R_SUCCESS) {
                        dns_zone_log(zone, ISC_LOG_ERROR, "zone_nsec3chain:"
                                     "dns_db_allrdatasets -> %s",
                                     dns_result_totext(result));
                        goto failure;
                }
                for (result = dns_rdatasetiter_first(iterator);
                     result == ISC_R_SUCCESS;
                     result = dns_rdatasetiter_next(iterator)) {
                        dns_rdatasetiter_current(iterator, &rdataset);
                        if (rdataset.type == dns_rdatatype_nsec)
                                rebuild_nsec = ISC_TRUE;
                        if (rdataset.type == dns_rdatatype_nsec3param)
                                rebuild_nsec3 = ISC_TRUE;
                        dns_rdataset_disassociate(&rdataset);
                }
                dns_rdatasetiter_destroy(&iterator);
                dns_db_detachnode(db, &node);

                if (rebuild_nsec) {
                        if (nsec3chain != NULL)
                                dns_dbiterator_pause(nsec3chain->dbiterator);
                        result = updatesecure(db, version, &zone->origin,
                                              zone->minimum, ISC_TRUE,
                                              &nsec_diff);
                        if (result != ISC_R_SUCCESS) {
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "zone_nsec3chain:"
                                             "updatesecure -> %s",
                                             dns_result_totext(result));
                                goto failure;
                        }
                }
                if (rebuild_nsec3) {
                        result = dns_nsec3_addnsec3s(db, version,
                                                     dns_db_origin(db),
                                                     zone->minimum, ISC_FALSE,
                                                     &nsec3_diff);
                        if (result != ISC_R_SUCCESS) {
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "zone_nsec3chain:"
                                             "dns_nsec3_addnsec3s -> %s",
                                             dns_result_totext(result));
                                goto failure;
                        }
                }
        }

        /*
         * Add / update signatures for the NSEC3 records.
         */
        result = update_sigs(&nsec3_diff, db, version, zone_keys,
                             nkeys, zone, inception, expire, now,
                             check_ksk, keyset_kskonly, &sig_diff);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR, "zone_nsec3chain:"
                             "update_sigs -> %s", dns_result_totext(result));
                goto failure;
        }

        /*
         * We have changed the NSEC3PARAM or private RRsets
         * above so we need to update the signatures.
         */
        result = update_sigs(&param_diff, db, version, zone_keys,
                             nkeys, zone, inception, expire, now,
                             check_ksk, keyset_kskonly, &sig_diff);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR, "zone_nsec3chain:"
                             "update_sigs -> %s", dns_result_totext(result));
                goto failure;
        }

        if (updatensec) {
                if (nsec3chain != NULL)
                        dns_dbiterator_pause(nsec3chain->dbiterator);
                result = updatesecure(db, version, &zone->origin,
                                      zone->minimum, ISC_FALSE, &nsec_diff);
                if (result != ISC_R_SUCCESS) {
                        dns_zone_log(zone, ISC_LOG_ERROR, "zone_nsec3chain:"
                                     "updatesecure -> %s",
                                     dns_result_totext(result));
                        goto failure;
                }
        }

        result = update_sigs(&nsec_diff, db, version, zone_keys,
                             nkeys, zone, inception, expire, now,
                             check_ksk, keyset_kskonly, &sig_diff);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR, "zone_nsec3chain:"
                             "update_sigs -> %s", dns_result_totext(result));
                goto failure;
        }

        /*
         * If we made no effective changes to the zone then we can just
         * cleanup otherwise we need to increment the serial.
         */
        if (ISC_LIST_HEAD(sig_diff.tuples) == NULL)
                goto done;

        result = del_sigs(zone, db, version, &zone->origin, dns_rdatatype_soa,
                          &sig_diff, zone_keys, nkeys, now, ISC_FALSE);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR, "zone_nsec3chain:"
                             "del_sigs -> %s", dns_result_totext(result));
                goto failure;
        }

        result = increment_soa_serial(db, version, &sig_diff, zone->mctx);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR, "zone_nsec3chain:"
                             "increment_soa_serial -> %s",
                             dns_result_totext(result));
                goto failure;
        }

        result = add_sigs(db, version, &zone->origin, dns_rdatatype_soa,
                          &sig_diff, zone_keys, nkeys, zone->mctx, inception,
                          soaexpire, check_ksk, keyset_kskonly);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR, "zone_nsec3chain:"
                             "add_sigs -> %s", dns_result_totext(result));
                goto failure;
        }

        /* Write changes to journal file. */
        CHECK(zone_journal(zone, &sig_diff, "zone_nsec3chain"));

        LOCK_ZONE(zone);
        zone_needdump(zone, DNS_DUMP_DELAY);
        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDNOTIFY);
        UNLOCK_ZONE(zone);

 done:
        /*
         * Pause all iterators so that dns_db_closeversion() can succeed.
         */
        LOCK_ZONE(zone);
        for (nsec3chain = ISC_LIST_HEAD(zone->nsec3chain);
             nsec3chain != NULL;
             nsec3chain = ISC_LIST_NEXT(nsec3chain, link))
                dns_dbiterator_pause(nsec3chain->dbiterator);
        UNLOCK_ZONE(zone);

        /*
         * Everything has succeeded. Commit the changes.
         */
        dns_db_closeversion(db, &version, ISC_TRUE);

        /*
         * Everything succeeded so we can clean these up now.
         */
        nsec3chain = ISC_LIST_HEAD(cleanup);
        while (nsec3chain != NULL) {
                ISC_LIST_UNLINK(cleanup, nsec3chain, link);
                dns_db_detach(&nsec3chain->db);
                dns_dbiterator_destroy(&nsec3chain->dbiterator);
                isc_mem_put(zone->mctx, nsec3chain, sizeof *nsec3chain);
                nsec3chain = ISC_LIST_HEAD(cleanup);
        }

        set_resigntime(zone);

 failure:
        if (result != ISC_R_SUCCESS)
                dns_zone_log(zone, ISC_LOG_ERROR, "zone_nsec3chain: %s",
                             dns_result_totext(result));
        /*
         * On error roll back the current nsec3chain.
         */
        if (result != ISC_R_SUCCESS && nsec3chain != NULL) {
                if (nsec3chain->done) {
                        dns_db_detach(&nsec3chain->db);
                        dns_dbiterator_destroy(&nsec3chain->dbiterator);
                        isc_mem_put(zone->mctx, nsec3chain, sizeof *nsec3chain);
                } else {
                        result = dns_dbiterator_first(nsec3chain->dbiterator);
                        RUNTIME_CHECK(result == ISC_R_SUCCESS);
                        dns_dbiterator_pause(nsec3chain->dbiterator);
                        nsec3chain->delete_nsec = nsec3chain->save_delete_nsec;
                }
        }

        /*
         * Rollback the cleanup list.
         */
        nsec3chain = ISC_LIST_TAIL(cleanup);
        while (nsec3chain != NULL) {
                ISC_LIST_UNLINK(cleanup, nsec3chain, link);
                if (nsec3chain->done) {
                        dns_db_detach(&nsec3chain->db);
                        dns_dbiterator_destroy(&nsec3chain->dbiterator);
                        isc_mem_put(zone->mctx, nsec3chain, sizeof *nsec3chain);
                } else {
                        LOCK_ZONE(zone);
                        ISC_LIST_PREPEND(zone->nsec3chain, nsec3chain, link);
                        UNLOCK_ZONE(zone);
                        result = dns_dbiterator_first(nsec3chain->dbiterator);
                        RUNTIME_CHECK(result == ISC_R_SUCCESS);
                        dns_dbiterator_pause(nsec3chain->dbiterator);
                        nsec3chain->delete_nsec = nsec3chain->save_delete_nsec;
                }
                nsec3chain = ISC_LIST_TAIL(cleanup);
        }

        LOCK_ZONE(zone);
        for (nsec3chain = ISC_LIST_HEAD(zone->nsec3chain);
             nsec3chain != NULL;
             nsec3chain = ISC_LIST_NEXT(nsec3chain, link))
                dns_dbiterator_pause(nsec3chain->dbiterator);
        UNLOCK_ZONE(zone);

        dns_diff_clear(&param_diff);
        dns_diff_clear(&nsec3_diff);
        dns_diff_clear(&nsec_diff);
        dns_diff_clear(&sig_diff);

        if (iterator != NULL)
                dns_rdatasetiter_destroy(&iterator);

        for (i = 0; i < nkeys; i++)
                dst_key_free(&zone_keys[i]);

        if (node != NULL)
                dns_db_detachnode(db, &node);
        if (version != NULL) {
                dns_db_closeversion(db, &version, ISC_FALSE);
                dns_db_detach(&db);
        } else if (db != NULL)
                dns_db_detach(&db);

        LOCK_ZONE(zone);
        if (ISC_LIST_HEAD(zone->nsec3chain) != NULL) {
                isc_interval_t i;
                if (zone->update_disabled || result != ISC_R_SUCCESS)
                        isc_interval_set(&i, 60, 0);            /* 1 minute */
                else
                        isc_interval_set(&i, 0, 10000000);      /* 10 ms */
                isc_time_nowplusinterval(&zone->nsec3chaintime, &i);
        } else
                isc_time_settoepoch(&zone->nsec3chaintime);
        UNLOCK_ZONE(zone);
}

static isc_result_t
del_sig(dns_db_t *db, dns_dbversion_t *version, dns_name_t *name,
        dns_dbnode_t *node, unsigned int nkeys, dns_secalg_t algorithm,
        isc_uint16_t keyid, dns_diff_t *diff)
{
        dns_rdata_rrsig_t rrsig;
        dns_rdataset_t rdataset;
        dns_rdatasetiter_t *iterator = NULL;
        isc_result_t result;

        result = dns_db_allrdatasets(db, node, version, 0, &iterator);
        if (result != ISC_R_SUCCESS) {
                if (result == ISC_R_NOTFOUND)
                        result = ISC_R_SUCCESS;
                return (result);
        }

        dns_rdataset_init(&rdataset);
        for (result = dns_rdatasetiter_first(iterator);
             result == ISC_R_SUCCESS;
             result = dns_rdatasetiter_next(iterator)) {
                dns_rdatasetiter_current(iterator, &rdataset);
                if (nkeys == 0 && rdataset.type == dns_rdatatype_nsec) {
                        for (result = dns_rdataset_first(&rdataset);
                             result == ISC_R_SUCCESS;
                             result = dns_rdataset_next(&rdataset)) {
                                dns_rdata_t rdata = DNS_RDATA_INIT;
                                dns_rdataset_current(&rdataset, &rdata);
                                CHECK(update_one_rr(db, version, diff,
                                                    DNS_DIFFOP_DEL, name,
                                                    rdataset.ttl, &rdata));
                        }
                        if (result != ISC_R_NOMORE)
                                goto failure;
                        dns_rdataset_disassociate(&rdataset);
                        continue;
                }
                if (rdataset.type != dns_rdatatype_rrsig) {
                        dns_rdataset_disassociate(&rdataset);
                        continue;
                }
                for (result = dns_rdataset_first(&rdataset);
                     result == ISC_R_SUCCESS;
                     result = dns_rdataset_next(&rdataset)) {
                        dns_rdata_t rdata = DNS_RDATA_INIT;
                        dns_rdataset_current(&rdataset, &rdata);
                        CHECK(dns_rdata_tostruct(&rdata, &rrsig, NULL));
                        if (rrsig.algorithm != algorithm ||
                            rrsig.keyid != keyid)
                                continue;
                        CHECK(update_one_rr(db, version, diff,
                                            DNS_DIFFOP_DELRESIGN, name,
                                            rdataset.ttl, &rdata));
                }
                dns_rdataset_disassociate(&rdataset);
                if (result != ISC_R_NOMORE)
                        break;
        }
        if (result == ISC_R_NOMORE)
                result = ISC_R_SUCCESS;
 failure:
        if (dns_rdataset_isassociated(&rdataset))
                dns_rdataset_disassociate(&rdataset);
        dns_rdatasetiter_destroy(&iterator);
        return (result);
}

/*
 * Incrementally sign the zone using the keys requested.
 * Builds the NSEC chain if required.
 */
static void
zone_sign(dns_zone_t *zone) {
        dns_db_t *db = NULL;
        dns_dbnode_t *node = NULL;
        dns_dbversion_t *version = NULL;
        dns_diff_t sig_diff;
        dns_diff_t post_diff;
        dns_fixedname_t fixed;
        dns_fixedname_t nextfixed;
        dns_name_t *name, *nextname;
        dns_rdataset_t rdataset;
        dns_signing_t *signing, *nextsigning;
        dns_signinglist_t cleanup;
        dst_key_t *zone_keys[DNS_MAXZONEKEYS];
        isc_int32_t signatures;
        isc_boolean_t check_ksk, keyset_kskonly, is_ksk;
        isc_boolean_t commit = ISC_FALSE;
        isc_boolean_t delegation;
        isc_boolean_t build_nsec = ISC_FALSE;
        isc_boolean_t build_nsec3 = ISC_FALSE;
        isc_boolean_t first;
        isc_result_t result;
        isc_stdtime_t now, inception, soaexpire, expire;
        isc_uint32_t jitter;
        unsigned int i, j;
        unsigned int nkeys = 0;
        isc_uint32_t nodes;

        dns_rdataset_init(&rdataset);
        dns_fixedname_init(&fixed);
        name = dns_fixedname_name(&fixed);
        dns_fixedname_init(&nextfixed);
        nextname = dns_fixedname_name(&nextfixed);
        dns_diff_init(zone->mctx, &sig_diff);
        sig_diff.resign = zone->sigresigninginterval;
        dns_diff_init(zone->mctx, &post_diff);
        ISC_LIST_INIT(cleanup);

        /*
         * Updates are disabled.  Pause for 5 minutes.
         */
        if (zone->update_disabled) {
                result = ISC_R_FAILURE;
                goto failure;
        }

        ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
        dns_db_attach(zone->db, &db);
        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);

        result = dns_db_newversion(db, &version);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "zone_sign:dns_db_newversion -> %s",
                             dns_result_totext(result));
                goto failure;
        }

        result = find_zone_keys(zone, db, version, zone->mctx,
                                DNS_MAXZONEKEYS, zone_keys, &nkeys);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "zone_sign:find_zone_keys -> %s",
                             dns_result_totext(result));
                goto failure;
        }

        isc_stdtime_get(&now);
        inception = now - 3600; /* Allow for clock skew. */
        soaexpire = now + dns_zone_getsigvalidityinterval(zone);

        /*
         * Spread out signatures over time if they happen to be
         * clumped.  We don't do this for each add_sigs() call as
         * we still want some clustering to occur.
         */
        isc_random_get(&jitter);
        expire = soaexpire - jitter % 3600;

        /*
         * We keep pulling nodes off each iterator in turn until
         * we have no more nodes to pull off or we reach the limits
         * for this quantum.
         */
        nodes = zone->nodes;
        signatures = zone->signatures;
        signing = ISC_LIST_HEAD(zone->signing);
        first = ISC_TRUE;

        check_ksk = DNS_ZONE_OPTION(zone, DNS_ZONEOPT_UPDATECHECKKSK);
        keyset_kskonly = DNS_ZONE_OPTION(zone, DNS_ZONEOPT_DNSKEYKSKONLY);

        /* Determine which type of chain to build */
        CHECK(dns_private_chains(db, version, zone->privatetype,
                                 &build_nsec, &build_nsec3));

        /* If neither chain is found, default to NSEC */
        if (!build_nsec && !build_nsec3)
                build_nsec = ISC_TRUE;

        while (signing != NULL && nodes-- > 0 && signatures > 0) {
                nextsigning = ISC_LIST_NEXT(signing, link);

                ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
                if (signing->done || signing->db != zone->db) {
                        /*
                         * The zone has been reloaded.  We will have
                         * created new signings as part of the reload
                         * process so we can destroy this one.
                         */
                        ISC_LIST_UNLINK(zone->signing, signing, link);
                        ISC_LIST_APPEND(cleanup, signing, link);
                        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
                        goto next_signing;
                }
                ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);

                if (signing->db != db)
                        goto next_signing;

                delegation = ISC_FALSE;

                if (first && signing->delete) {
                        /*
                         * Remove the key we are deleting from consideration.
                         */
                        for (i = 0, j = 0; i < nkeys; i++) {
                                /*
                                 * Find the key we want to remove.
                                 */
                                if (ALG(zone_keys[i]) == signing->algorithm &&
                                    dst_key_id(zone_keys[i]) == signing->keyid)
                                {
                                        if (KSK(zone_keys[i]))
                                                dst_key_free(&zone_keys[i]);
                                        continue;
                                }
                                zone_keys[j] = zone_keys[i];
                                j++;
                        }
                        nkeys = j;
                }

                dns_dbiterator_current(signing->dbiterator, &node, name);

                if (signing->delete) {
                        dns_dbiterator_pause(signing->dbiterator);
                        CHECK(del_sig(db, version, name, node, nkeys,
                                      signing->algorithm, signing->keyid,
                                      &sig_diff));
                }

                /*
                 * On the first pass we need to check if the current node
                 * has not been obscured.
                 */
                if (first) {
                        dns_fixedname_t ffound;
                        dns_name_t *found;
                        dns_fixedname_init(&ffound);
                        found = dns_fixedname_name(&ffound);
                        result = dns_db_find(db, name, version,
                                             dns_rdatatype_soa,
                                             DNS_DBFIND_NOWILD, 0, NULL, found,
                                             NULL, NULL);
                        if ((result == DNS_R_DELEGATION ||
                            result == DNS_R_DNAME) &&
                            !dns_name_equal(name, found)) {
                                /*
                                 * Remember the obscuring name so that
                                 * we skip all obscured names.
                                 */
                                dns_name_copy(found, name, NULL);
                                delegation = ISC_TRUE;
                                goto next_node;
                        }
                }

                /*
                 * Process one node.
                 */
                dns_dbiterator_pause(signing->dbiterator);
                for (i = 0; i < nkeys; i++) {
                        isc_boolean_t both = ISC_FALSE;

                        /*
                         * Find the keys we want to sign with.
                         */
                        if (!dst_key_isprivate(zone_keys[i]))
                                continue;

                        /*
                         * When adding look for the specific key.
                         */
                        if (!signing->delete &&
                            (dst_key_alg(zone_keys[i]) != signing->algorithm ||
                             dst_key_id(zone_keys[i]) != signing->keyid))
                                continue;

                        /*
                         * When deleting make sure we are properly signed
                         * with the algorithm that was being removed.
                         */
                        if (signing->delete &&
                            ALG(zone_keys[i]) != signing->algorithm)
                                continue;

                        /*
                         * Do we do KSK processing?
                         */
                        if (check_ksk && !REVOKE(zone_keys[i])) {
                                isc_boolean_t have_ksk, have_nonksk;
                                if (KSK(zone_keys[i])) {
                                        have_ksk = ISC_TRUE;
                                        have_nonksk = ISC_FALSE;
                                } else {
                                        have_ksk = ISC_FALSE;
                                        have_nonksk = ISC_TRUE;
                                }
                                for (j = 0; j < nkeys; j++) {
                                        if (j == i ||
                                            ALG(zone_keys[i]) !=
                                            ALG(zone_keys[j]))
                                                continue;
                                        if (REVOKE(zone_keys[j]))
                                                continue;
                                        if (KSK(zone_keys[j]))
                                                have_ksk = ISC_TRUE;
                                        else
                                                have_nonksk = ISC_TRUE;
                                        both = have_ksk && have_nonksk;
                                        if (both)
                                                break;
                                }
                        }
                        if (both || REVOKE(zone_keys[i]))
                                is_ksk = KSK(zone_keys[i]);
                        else
                                is_ksk = ISC_FALSE;

                        CHECK(sign_a_node(db, name, node, version, build_nsec3,
                                          build_nsec, zone_keys[i], inception,
                                          expire, zone->minimum, is_ksk,
                                          ISC_TF(both && keyset_kskonly),
                                          &delegation, &sig_diff,
                                          &signatures, zone->mctx));
                        /*
                         * If we are adding we are done.  Look for other keys
                         * of the same algorithm if deleting.
                         */
                        if (!signing->delete)
                                break;
                }

                /*
                 * Go onto next node.
                 */
 next_node:
                first = ISC_FALSE;
                dns_db_detachnode(db, &node);
                do {
                        result = dns_dbiterator_next(signing->dbiterator);
                        if (result == ISC_R_NOMORE) {
                                ISC_LIST_UNLINK(zone->signing, signing, link);
                                ISC_LIST_APPEND(cleanup, signing, link);
                                dns_dbiterator_pause(signing->dbiterator);
                                if (nkeys != 0 && build_nsec) {
                                        /*
                                         * We have finished regenerating the
                                         * zone with a zone signing key.
                                         * The NSEC chain is now complete and
                                         * there is a full set of signatures
                                         * for the zone.  We can now clear the
                                         * OPT bit from the NSEC record.
                                         */
                                        result = updatesecure(db, version,
                                                              &zone->origin,
                                                              zone->minimum,
                                                              ISC_FALSE,
                                                              &post_diff);
                                        if (result != ISC_R_SUCCESS) {
                                                dns_zone_log(zone,
                                                             ISC_LOG_ERROR,
                                                    "updatesecure -> %s",
                                                    dns_result_totext(result));
                                                goto failure;
                                        }
                                }
                                result = updatesignwithkey(zone, signing,
                                                           version,
                                                           build_nsec3,
                                                           zone->minimum,
                                                           &post_diff);
                                if (result != ISC_R_SUCCESS) {
                                        dns_zone_log(zone, ISC_LOG_ERROR,
                                                     "updatesignwithkey -> %s",
                                                     dns_result_totext(result));
                                        goto failure;
                                }
                                build_nsec = ISC_FALSE;
                                goto next_signing;
                        } else if (result != ISC_R_SUCCESS) {
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                        "zone_sign:dns_dbiterator_next -> %s",
                                             dns_result_totext(result));
                                goto failure;
                        } else if (delegation) {
                                dns_dbiterator_current(signing->dbiterator,
                                                       &node, nextname);
                                dns_db_detachnode(db, &node);
                                if (!dns_name_issubdomain(nextname, name))
                                        break;
                        } else
                                break;
                } while (1);
                continue;

 next_signing:
                dns_dbiterator_pause(signing->dbiterator);
                signing = nextsigning;
                first = ISC_TRUE;
        }

        if (ISC_LIST_HEAD(post_diff.tuples) != NULL) {
                result = update_sigs(&post_diff, db, version, zone_keys,
                                     nkeys, zone, inception, expire, now,
                                     check_ksk, keyset_kskonly, &sig_diff);
                if (result != ISC_R_SUCCESS) {
                        dns_zone_log(zone, ISC_LOG_ERROR, "zone_sign:"
                                     "update_sigs -> %s",
                                     dns_result_totext(result));
                        goto failure;
                }
        }

        /*
         * Have we changed anything?
         */
        if (ISC_LIST_HEAD(sig_diff.tuples) == NULL) {
                result = ISC_R_SUCCESS;
                goto pauseall;
        }

        commit = ISC_TRUE;

        result = del_sigs(zone, db, version, &zone->origin, dns_rdatatype_soa,
                          &sig_diff, zone_keys, nkeys, now, ISC_FALSE);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "zone_sign:del_sigs -> %s",
                             dns_result_totext(result));
                goto failure;
        }

        result = increment_soa_serial(db, version, &sig_diff, zone->mctx);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "zone_sign:increment_soa_serial -> %s",
                             dns_result_totext(result));
                goto failure;
        }

        /*
         * Generate maximum life time signatures so that the above loop
         * termination is sensible.
         */
        result = add_sigs(db, version, &zone->origin, dns_rdatatype_soa,
                          &sig_diff, zone_keys, nkeys, zone->mctx, inception,
                          soaexpire, check_ksk, keyset_kskonly);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "zone_sign:add_sigs -> %s",
                             dns_result_totext(result));
                goto failure;
        }

        /*
         * Write changes to journal file.
         */
        CHECK(zone_journal(zone, &sig_diff, "zone_sign"));

 pauseall:
        /*
         * Pause all iterators so that dns_db_closeversion() can succeed.
         */
        for (signing = ISC_LIST_HEAD(zone->signing);
             signing != NULL;
             signing = ISC_LIST_NEXT(signing, link))
                dns_dbiterator_pause(signing->dbiterator);

        for (signing = ISC_LIST_HEAD(cleanup);
             signing != NULL;
             signing = ISC_LIST_NEXT(signing, link))
                dns_dbiterator_pause(signing->dbiterator);

        /*
         * Everything has succeeded. Commit the changes.
         */
        dns_db_closeversion(db, &version, commit);

        /*
         * Everything succeeded so we can clean these up now.
         */
        signing = ISC_LIST_HEAD(cleanup);
        while (signing != NULL) {
                ISC_LIST_UNLINK(cleanup, signing, link);
                dns_db_detach(&signing->db);
                dns_dbiterator_destroy(&signing->dbiterator);
                isc_mem_put(zone->mctx, signing, sizeof *signing);
                signing = ISC_LIST_HEAD(cleanup);
        }

        set_resigntime(zone);

        if (commit) {
                LOCK_ZONE(zone);
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDNOTIFY);
                zone_needdump(zone, DNS_DUMP_DELAY);
                UNLOCK_ZONE(zone);
        }

 failure:
        /*
         * Rollback the cleanup list.
         */
        signing = ISC_LIST_HEAD(cleanup);
        while (signing != NULL) {
                ISC_LIST_UNLINK(cleanup, signing, link);
                ISC_LIST_PREPEND(zone->signing, signing, link);
                dns_dbiterator_first(signing->dbiterator);
                dns_dbiterator_pause(signing->dbiterator);
                signing = ISC_LIST_HEAD(cleanup);
        }

        for (signing = ISC_LIST_HEAD(zone->signing);
             signing != NULL;
             signing = ISC_LIST_NEXT(signing, link))
                dns_dbiterator_pause(signing->dbiterator);

        dns_diff_clear(&sig_diff);

        for (i = 0; i < nkeys; i++)
                dst_key_free(&zone_keys[i]);

        if (node != NULL)
                dns_db_detachnode(db, &node);

        if (version != NULL) {
                dns_db_closeversion(db, &version, ISC_FALSE);
                dns_db_detach(&db);
        } else if (db != NULL)
                dns_db_detach(&db);

        if (ISC_LIST_HEAD(zone->signing) != NULL) {
                isc_interval_t i;
                if (zone->update_disabled || result != ISC_R_SUCCESS)
                        isc_interval_set(&i, 60, 0);            /* 1 minute */
                else
                        isc_interval_set(&i, 0, 10000000);      /* 10 ms */
                isc_time_nowplusinterval(&zone->signingtime, &i);
        } else
                isc_time_settoepoch(&zone->signingtime);
}

static void
normalize_key(dns_rdata_t *rr, dns_rdata_t *target,
              unsigned char *data, int size) {
        dns_rdata_dnskey_t dnskey;
        dns_rdata_keydata_t keydata;
        isc_buffer_t buf;

        dns_rdata_reset(target);
        isc_buffer_init(&buf, data, size);

        switch (rr->type) {
            case dns_rdatatype_dnskey:
                dns_rdata_tostruct(rr, &dnskey, NULL);
                dnskey.flags &= ~DNS_KEYFLAG_REVOKE;
                dns_rdata_fromstruct(target, rr->rdclass, dns_rdatatype_dnskey,
                                     &dnskey, &buf);
                break;
            case dns_rdatatype_keydata:
                dns_rdata_tostruct(rr, &keydata, NULL);
                dns_keydata_todnskey(&keydata, &dnskey, NULL);
                dns_rdata_fromstruct(target, rr->rdclass, dns_rdatatype_dnskey,
                                     &dnskey, &buf);
                break;
            default:
                INSIST(0);
        }
}

/*
 * 'rdset' contains either a DNSKEY rdataset from the zone apex, or
 * a KEYDATA rdataset from the key zone.
 *
 * 'rr' contains either a DNSKEY record, or a KEYDATA record
 *
 * After normalizing keys to the same format (DNSKEY, with revoke bit
 * cleared), return ISC_TRUE if a key that matches 'rr' is found in
 * 'rdset', or ISC_FALSE if not.
 */

static isc_boolean_t
matchkey(dns_rdataset_t *rdset, dns_rdata_t *rr) {
        unsigned char data1[4096], data2[4096];
        dns_rdata_t rdata, rdata1, rdata2;
        isc_result_t result;

        dns_rdata_init(&rdata);
        dns_rdata_init(&rdata1);
        dns_rdata_init(&rdata2);

        normalize_key(rr, &rdata1, data1, sizeof(data1));

        for (result = dns_rdataset_first(rdset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(rdset)) {
                dns_rdata_reset(&rdata);
                dns_rdataset_current(rdset, &rdata);
                normalize_key(&rdata, &rdata2, data2, sizeof(data2));
                if (dns_rdata_compare(&rdata1, &rdata2) == 0)
                        return (ISC_TRUE);
        }

        return (ISC_FALSE);
}

/*
 * Calculate the refresh interval for a keydata zone, per
 * RFC5011: MAX(1 hr,
 *              MIN(15 days,
 *                  1/2 * OrigTTL,
 *                  1/2 * RRSigExpirationInterval))
 * or for retries: MAX(1 hr,
 *                     MIN(1 day,
 *                         1/10 * OrigTTL,
 *                         1/10 * RRSigExpirationInterval))
 */
static inline isc_stdtime_t
refresh_time(dns_keyfetch_t *kfetch, isc_boolean_t retry) {
        isc_result_t result;
        isc_uint32_t t;
        dns_rdataset_t *rdset;
        dns_rdata_t sigrr = DNS_RDATA_INIT;
        dns_rdata_sig_t sig;
        isc_stdtime_t now;

        isc_stdtime_get(&now);

        if (dns_rdataset_isassociated(&kfetch->dnskeysigset))
                rdset = &kfetch->dnskeysigset;
        else
                return (now + HOUR);

        result = dns_rdataset_first(rdset);
        if (result != ISC_R_SUCCESS)
                return (now + HOUR);

        dns_rdataset_current(rdset, &sigrr);
        result = dns_rdata_tostruct(&sigrr, &sig, NULL);
        RUNTIME_CHECK(result == ISC_R_SUCCESS);

        if (!retry) {
                t = sig.originalttl / 2;

                if (isc_serial_gt(sig.timeexpire, now)) {
                        isc_uint32_t exp = (sig.timeexpire - now) / 2;
                        if (t > exp)
                                t = exp;
                }

                if (t > (15*DAY))
                        t = (15*DAY);

                if (t < HOUR)
                        t = HOUR;
        } else {
                t = sig.originalttl / 10;

                if (isc_serial_gt(sig.timeexpire, now)) {
                        isc_uint32_t exp = (sig.timeexpire - now) / 10;
                        if (t > exp)
                                t = exp;
                }

                if (t > DAY)
                        t = DAY;

                if (t < HOUR)
                        t = HOUR;
        }

        return (now + t);
}

/*
 * This routine is called when no changes are needed in a KEYDATA
 * record except to simply update the refresh timer.  Caller should
 * hold zone lock.
 */
static isc_result_t
minimal_update(dns_keyfetch_t *kfetch, dns_dbversion_t *ver, dns_diff_t *diff)
{
        isc_result_t result;
        isc_buffer_t keyb;
        unsigned char key_buf[4096];
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_rdata_keydata_t keydata;
        dns_name_t *name;
        dns_zone_t *zone = kfetch->zone;
        isc_stdtime_t now;

        name = dns_fixedname_name(&kfetch->name);
        isc_stdtime_get(&now);

        for (result = dns_rdataset_first(&kfetch->keydataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(&kfetch->keydataset)) {
                dns_rdata_reset(&rdata);
                dns_rdataset_current(&kfetch->keydataset, &rdata);

                /* Delete old version */
                CHECK(update_one_rr(kfetch->db, ver, diff, DNS_DIFFOP_DEL,
                                    name, 0, &rdata));

                /* Update refresh timer */
                CHECK(dns_rdata_tostruct(&rdata, &keydata, NULL));
                keydata.refresh = refresh_time(kfetch, ISC_TRUE);
                set_refreshkeytimer(zone, &keydata, now);

                dns_rdata_reset(&rdata);
                isc_buffer_init(&keyb, key_buf, sizeof(key_buf));
                CHECK(dns_rdata_fromstruct(&rdata,
                                           zone->rdclass, dns_rdatatype_keydata,
                                           &keydata, &keyb));

                /* Insert updated version */
                CHECK(update_one_rr(kfetch->db, ver, diff, DNS_DIFFOP_ADD,
                                    name, 0, &rdata));
        }
        result = ISC_R_SUCCESS;
  failure:
        return (result);
}

/*
 * Verify that DNSKEY set is signed by the key specified in 'keydata'.
 */
static isc_boolean_t
revocable(dns_keyfetch_t *kfetch, dns_rdata_keydata_t *keydata) {
        isc_result_t result;
        dns_name_t *keyname;
        isc_mem_t *mctx;
        dns_rdata_t sigrr = DNS_RDATA_INIT;
        dns_rdata_t rr = DNS_RDATA_INIT;
        dns_rdata_rrsig_t sig;
        dns_rdata_dnskey_t dnskey;
        dst_key_t *dstkey = NULL;
        unsigned char key_buf[4096];
        isc_buffer_t keyb;
        isc_boolean_t answer = ISC_FALSE;

        REQUIRE(kfetch != NULL && keydata != NULL);
        REQUIRE(dns_rdataset_isassociated(&kfetch->dnskeysigset));

        keyname = dns_fixedname_name(&kfetch->name);
        mctx = kfetch->zone->view->mctx;

        /* Generate a key from keydata */
        isc_buffer_init(&keyb, key_buf, sizeof(key_buf));
        dns_keydata_todnskey(keydata, &dnskey, NULL);
        dns_rdata_fromstruct(&rr, keydata->common.rdclass, dns_rdatatype_dnskey,
                                     &dnskey, &keyb);
        result = dns_dnssec_keyfromrdata(keyname, &rr, mctx, &dstkey);
        if (result != ISC_R_SUCCESS)
                return (ISC_FALSE);

        /* See if that key generated any of the signatures */
        for (result = dns_rdataset_first(&kfetch->dnskeysigset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(&kfetch->dnskeysigset)) {
                dns_fixedname_t fixed;
                dns_fixedname_init(&fixed);

                dns_rdata_reset(&sigrr);
                dns_rdataset_current(&kfetch->dnskeysigset, &sigrr);
                result = dns_rdata_tostruct(&sigrr, &sig, NULL);
                RUNTIME_CHECK(result == ISC_R_SUCCESS);

                if (dst_key_alg(dstkey) == sig.algorithm &&
                    (dst_key_id(dstkey) == sig.keyid ||
                     dst_key_rid(dstkey) == sig.keyid)) {
                        result = dns_dnssec_verify2(keyname,
                                            &kfetch->dnskeyset,
                                            dstkey, ISC_FALSE, mctx, &sigrr,
                                            dns_fixedname_name(&fixed));

                        dns_zone_log(kfetch->zone, ISC_LOG_DEBUG(3),
                                     "Confirm revoked DNSKEY is self-signed: "
                                     "%s", dns_result_totext(result));

                        if (result == ISC_R_SUCCESS) {
                                answer = ISC_TRUE;
                                break;
                        }
                }
        }

        dst_key_free(&dstkey);
        return (answer);
}

/*
 * A DNSKEY set has been fetched from the zone apex of a zone whose trust
 * anchors are being managed; scan the keyset, and update the key zone and the
 * local trust anchors according to RFC5011.
 */
static void
keyfetch_done(isc_task_t *task, isc_event_t *event) {
        isc_result_t result, eresult;
        dns_fetchevent_t *devent;
        dns_keyfetch_t *kfetch;
        dns_zone_t *zone;
        isc_mem_t *mctx = NULL;
        dns_keytable_t *secroots = NULL;
        dns_dbversion_t *ver = NULL;
        dns_diff_t diff;
        isc_boolean_t alldone = ISC_FALSE;
        isc_boolean_t commit = ISC_FALSE;
        dns_name_t *keyname;
        dns_rdata_t sigrr = DNS_RDATA_INIT;
        dns_rdata_t dnskeyrr = DNS_RDATA_INIT;
        dns_rdata_t keydatarr = DNS_RDATA_INIT;
        dns_rdata_rrsig_t sig;
        dns_rdata_dnskey_t dnskey;
        dns_rdata_keydata_t keydata;
        isc_boolean_t initializing;
        char namebuf[DNS_NAME_FORMATSIZE];
        unsigned char key_buf[4096];
        isc_buffer_t keyb;
        dst_key_t *dstkey;
        isc_stdtime_t now;
        int pending = 0;
        isc_boolean_t secure;
        isc_boolean_t free_needed;

        UNUSED(task);
        INSIST(event != NULL && event->ev_type == DNS_EVENT_FETCHDONE);
        INSIST(event->ev_arg != NULL);

        kfetch = event->ev_arg;
        zone = kfetch->zone;
        isc_mem_attach(zone->mctx, &mctx);
        keyname = dns_fixedname_name(&kfetch->name);

        devent = (dns_fetchevent_t *) event;
        eresult = devent->result;

        /* Free resources which are not of interest */
        if (devent->node != NULL)
                dns_db_detachnode(devent->db, &devent->node);
        if (devent->db != NULL)
                dns_db_detach(&devent->db);
        isc_event_free(&event);
        dns_resolver_destroyfetch(&kfetch->fetch);

        LOCK_ZONE(zone);
        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING) || zone->view == NULL)
                goto cleanup;

        isc_stdtime_get(&now);
        dns_name_format(keyname, namebuf, sizeof(namebuf));

        result = dns_view_getsecroots(zone->view, &secroots);
        INSIST(result == ISC_R_SUCCESS);

        dns_diff_init(mctx, &diff);
        diff.resign = zone->sigresigninginterval;

        CHECK(dns_db_newversion(kfetch->db, &ver));

        zone->refreshkeycount--;
        alldone = ISC_TF(zone->refreshkeycount == 0);

        if (alldone)
                DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_REFRESHING);

        /* Fetch failed */
        if (eresult != ISC_R_SUCCESS ||
            !dns_rdataset_isassociated(&kfetch->dnskeyset)) {
                dns_zone_log(zone, ISC_LOG_WARNING,
                             "Unable to fetch DNSKEY set "
                             "'%s': %s", namebuf, dns_result_totext(eresult));
                CHECK(minimal_update(kfetch, ver, &diff));
                goto done;
        }

        /* No RRSIGs found */
        if (!dns_rdataset_isassociated(&kfetch->dnskeysigset)) {
                dns_zone_log(zone, ISC_LOG_WARNING,
                             "No DNSKEY RRSIGs found for "
                             "'%s': %s", namebuf, dns_result_totext(eresult));
                CHECK(minimal_update(kfetch, ver, &diff));
                goto done;
        }

        /*
         * Validate the dnskeyset against the current trusted keys.
         */
        for (result = dns_rdataset_first(&kfetch->dnskeysigset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(&kfetch->dnskeysigset)) {
                dns_keynode_t *keynode = NULL;

                dns_rdata_reset(&sigrr);
                dns_rdataset_current(&kfetch->dnskeysigset, &sigrr);
                result = dns_rdata_tostruct(&sigrr, &sig, NULL);
                RUNTIME_CHECK(result == ISC_R_SUCCESS);

                result = dns_keytable_find(secroots, keyname, &keynode);
                while (result == ISC_R_SUCCESS) {
                        dns_keynode_t *nextnode = NULL;
                        dns_fixedname_t fixed;
                        dns_fixedname_init(&fixed);

                        dstkey = dns_keynode_key(keynode);
                        if (dstkey == NULL) /* fail_secure() was called */
                                break;

                        if (dst_key_alg(dstkey) == sig.algorithm &&
                            dst_key_id(dstkey) == sig.keyid) {
                                result = dns_dnssec_verify2(keyname,
                                                    &kfetch->dnskeyset,
                                                    dstkey, ISC_FALSE,
                                                    zone->view->mctx, &sigrr,
                                                    dns_fixedname_name(&fixed));

                                dns_zone_log(zone, ISC_LOG_DEBUG(3),
                                             "Verifying DNSKEY set for zone "
                                             "'%s': %s", namebuf,
                                             dns_result_totext(result));

                                if (result == ISC_R_SUCCESS) {
                                        kfetch->dnskeyset.trust =
                                                dns_trust_secure;
                                        kfetch->dnskeysigset.trust =
                                                dns_trust_secure;
                                        dns_keytable_detachkeynode(secroots,
                                                                   &keynode);
                                        break;
                                }
                        }

                        result = dns_keytable_nextkeynode(secroots,
                                                          keynode, &nextnode);
                        dns_keytable_detachkeynode(secroots, &keynode);
                        keynode = nextnode;
                }

                if (kfetch->dnskeyset.trust == dns_trust_secure)
                        break;
        }

        /*
         * If we were not able to verify the answer using the current
         * trusted keys then all we can do is look at any revoked keys.
         */
        secure = ISC_TF(kfetch->dnskeyset.trust == dns_trust_secure);

        /*
         * First scan keydataset to find keys that are not in dnskeyset
         *   - Missing keys which are not scheduled for removal,
         *     log a warning
         *   - Missing keys which are scheduled for removal and
         *     the remove hold-down timer has completed should
         *     be removed from the key zone
         *   - Missing keys whose acceptance timers have not yet
         *     completed, log a warning and reset the acceptance
         *     timer to 30 days in the future
         *   - All keys not being removed have their refresh timers
         *     updated
         */
        initializing = ISC_TRUE;
        for (result = dns_rdataset_first(&kfetch->keydataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(&kfetch->keydataset)) {
                dns_rdata_reset(&keydatarr);
                dns_rdataset_current(&kfetch->keydataset, &keydatarr);
                dns_rdata_tostruct(&keydatarr, &keydata, NULL);

                /*
                 * If any keydata record has a nonzero add holddown, then
                 * there was a pre-existing trust anchor for this domain;
                 * that means we are *not* initializing it and shouldn't
                 * automatically trust all the keys we find at the zone apex.
                 */
                initializing = initializing && ISC_TF(keydata.addhd == 0);

                if (! matchkey(&kfetch->dnskeyset, &keydatarr)) {
                        isc_boolean_t deletekey = ISC_FALSE;

                        if (!secure) {
                                if (now > keydata.removehd)
                                        deletekey = ISC_TRUE;
                        } else if (now < keydata.addhd) {
                                dns_zone_log(zone, ISC_LOG_WARNING,
                                             "Pending key unexpectedly missing "
                                             "from %s; restarting acceptance "
                                             "timer", namebuf);
                                keydata.addhd = now + MONTH;
                                keydata.refresh = refresh_time(kfetch,
                                                               ISC_FALSE);
                        } else if (keydata.addhd == 0) {
                                keydata.addhd = now;
                        } else if (keydata.removehd == 0) {
                                dns_zone_log(zone, ISC_LOG_WARNING,
                                             "Active key unexpectedly missing "
                                             "from %s", namebuf);
                                keydata.refresh = now + HOUR;
                        } else if (now > keydata.removehd) {
                                deletekey = ISC_TRUE;
                        } else {
                                keydata.refresh = refresh_time(kfetch,
                                                               ISC_FALSE);
                        }

                        if  (secure || deletekey) {
                                /* Delete old version */
                                CHECK(update_one_rr(kfetch->db, ver, &diff,
                                                    DNS_DIFFOP_DEL, keyname, 0,
                                                    &keydatarr));
                        }

                        if (!secure || deletekey)
                                continue;

                        dns_rdata_reset(&keydatarr);
                        isc_buffer_init(&keyb, key_buf, sizeof(key_buf));
                        dns_rdata_fromstruct(&keydatarr, zone->rdclass,
                                             dns_rdatatype_keydata,
                                             &keydata, &keyb);

                        /* Insert updated version */
                        CHECK(update_one_rr(kfetch->db, ver, &diff,
                                            DNS_DIFFOP_ADD, keyname, 0,
                                            &keydatarr));

                        set_refreshkeytimer(zone, &keydata, now);
                }
        }

        /*
         * Next scan dnskeyset:
         *   - If new keys are found (i.e., lacking a match in keydataset)
         *     add them to the key zone and set the acceptance timer
         *     to 30 days in the future (or to immediately if we've
         *     determined that we're initializing the zone for the
         *     first time)
         *   - Previously-known keys that have been revoked
         *     must be scheduled for removal from the key zone (or,
         *     if they hadn't been accepted as trust anchors yet
         *     anyway, removed at once)
         *   - Previously-known unrevoked keys whose acceptance timers
         *     have completed are promoted to trust anchors
         *   - All keys not being removed have their refresh
         *     timers updated
         */
        for (result = dns_rdataset_first(&kfetch->dnskeyset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(&kfetch->dnskeyset)) {
                isc_boolean_t revoked = ISC_FALSE;
                isc_boolean_t newkey = ISC_FALSE;
                isc_boolean_t updatekey = ISC_FALSE;
                isc_boolean_t deletekey = ISC_FALSE;
                isc_boolean_t trustkey = ISC_FALSE;

                dns_rdata_reset(&dnskeyrr);
                dns_rdataset_current(&kfetch->dnskeyset, &dnskeyrr);
                dns_rdata_tostruct(&dnskeyrr, &dnskey, NULL);

                /* Skip ZSK's */
                if (!ISC_TF(dnskey.flags & DNS_KEYFLAG_KSK))
                        continue;

                revoked = ISC_TF(dnskey.flags & DNS_KEYFLAG_REVOKE);

                if (matchkey(&kfetch->keydataset, &dnskeyrr)) {
                        dns_rdata_reset(&keydatarr);
                        dns_rdataset_current(&kfetch->keydataset, &keydatarr);
                        dns_rdata_tostruct(&keydatarr, &keydata, NULL);

                        if (revoked && revocable(kfetch, &keydata)) {
                                if (keydata.addhd > now) {
                                        /*
                                         * Key wasn't trusted yet, and now
                                         * it's been revoked?  Just remove it
                                         */
                                        deletekey = ISC_TRUE;
                                } else if (keydata.removehd == 0) {
                                        /* Remove from secroots */
                                        dns_view_untrust(zone->view, keyname,
                                                         &dnskey, mctx);

                                        /* If initializing, delete now */
                                        if (keydata.addhd == 0)
                                                deletekey = ISC_TRUE;
                                        else
                                                keydata.removehd = now + MONTH;
                                } else if (keydata.removehd < now) {
                                        /* Scheduled for removal */
                                        deletekey = ISC_TRUE;
                                }
                        } else if (revoked) {
                                if (secure && keydata.removehd == 0) {
                                        dns_zone_log(zone, ISC_LOG_WARNING,
                                                     "Active key for zone "
                                                     "'%s' is revoked but "
                                                     "did not self-sign; "
                                                         "ignoring.", namebuf);
                                                continue;
                                }
                        } else if (secure) {
                                if (keydata.removehd != 0) {
                                        /*
                                         * Key isn't revoked--but it
                                         * seems it used to be.
                                         * Remove it now and add it
                                         * back as if it were a fresh key.
                                         */
                                        deletekey = ISC_TRUE;
                                        newkey = ISC_TRUE;
                                } else if (keydata.addhd > now)
                                        pending++;
                                else if (keydata.addhd == 0)
                                        keydata.addhd = now;

                                if (keydata.addhd <= now)
                                        trustkey = ISC_TRUE;
                        }

                        if (!deletekey && !newkey)
                                updatekey = ISC_TRUE;
                } else if (secure) {
                        /*
                         * Key wasn't in the key zone but it's
                         * revoked now anyway, so just skip it
                         */
                        if (revoked)
                                continue;

                        /* Key wasn't in the key zone: add it */
                        newkey = ISC_TRUE;

                        if (initializing) {
                                dns_keytag_t tag = 0;
                                CHECK(compute_tag(keyname, &dnskey,
                                                  mctx, &tag));
                                dns_zone_log(zone, ISC_LOG_WARNING,
                                             "Initializing automatic trust "
                                             "anchor management for zone '%s'; "
                                             "DNSKEY ID %d is now trusted, "
                                             "waiving the normal 30-day "
                                             "waiting period.",
                                             namebuf, tag);
                                trustkey = ISC_TRUE;
                        }
                }

                /* Delete old version */
                if (deletekey || !newkey)
                        CHECK(update_one_rr(kfetch->db, ver, &diff,
                                            DNS_DIFFOP_DEL, keyname, 0,
                                            &keydatarr));

                if (updatekey) {
                        /* Set refresh timer */
                        keydata.refresh = refresh_time(kfetch, ISC_FALSE);
                        dns_rdata_reset(&keydatarr);
                        isc_buffer_init(&keyb, key_buf, sizeof(key_buf));
                        dns_rdata_fromstruct(&keydatarr, zone->rdclass,
                                             dns_rdatatype_keydata,
                                             &keydata, &keyb);

                        /* Insert updated version */
                        CHECK(update_one_rr(kfetch->db, ver, &diff,
                                            DNS_DIFFOP_ADD, keyname, 0,
                                            &keydatarr));
                } else if (newkey) {
                        /* Convert DNSKEY to KEYDATA */
                        dns_rdata_tostruct(&dnskeyrr, &dnskey, NULL);
                        dns_keydata_fromdnskey(&keydata, &dnskey, 0, 0, 0,
                                               NULL);
                        keydata.addhd = initializing ? now : now + MONTH;
                        keydata.refresh = refresh_time(kfetch, ISC_FALSE);
                        dns_rdata_reset(&keydatarr);
                        isc_buffer_init(&keyb, key_buf, sizeof(key_buf));
                        dns_rdata_fromstruct(&keydatarr, zone->rdclass,
                                             dns_rdatatype_keydata,
                                             &keydata, &keyb);

                        /* Insert into key zone */
                        CHECK(update_one_rr(kfetch->db, ver, &diff,
                                            DNS_DIFFOP_ADD, keyname, 0,
                                            &keydatarr));
                }

                if (trustkey) {
                        /* Trust this key. */
                        dns_rdata_tostruct(&dnskeyrr, &dnskey, NULL);
                        trust_key(zone, keyname, &dnskey, mctx);
                }

                if (!deletekey)
                        set_refreshkeytimer(zone, &keydata, now);
        }

        /*
         * RFC5011 says, "A trust point that has all of its trust anchors
         * revoked is considered deleted and is treated as if the trust
         * point was never configured."  But if someone revoked their
         * active key before the standby was trusted, that would mean the
         * zone would suddenly be nonsecured.  We avoid this by checking to
         * see if there's pending keydata.  If so, we put a null key in
         * the security roots; then all queries to the zone will fail.
         */
        if (pending != 0)
                fail_secure(zone, keyname);

 done:

        if (!ISC_LIST_EMPTY(diff.tuples)) {
                /* Write changes to journal file. */
                CHECK(increment_soa_serial(kfetch->db, ver, &diff, mctx));
                CHECK(zone_journal(zone, &diff, "keyfetch_done"));
                commit = ISC_TRUE;

                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_LOADED);
                zone_needdump(zone, 30);
        }

  failure:

        dns_diff_clear(&diff);
        if (ver != NULL)
                dns_db_closeversion(kfetch->db, &ver, commit);

 cleanup:
        dns_db_detach(&kfetch->db);

        INSIST(zone->irefs > 0);
        zone->irefs--;
        kfetch->zone = NULL;

        if (dns_rdataset_isassociated(&kfetch->keydataset))
                dns_rdataset_disassociate(&kfetch->keydataset);
        if (dns_rdataset_isassociated(&kfetch->dnskeyset))
                dns_rdataset_disassociate(&kfetch->dnskeyset);
        if (dns_rdataset_isassociated(&kfetch->dnskeysigset))
                dns_rdataset_disassociate(&kfetch->dnskeysigset);

        dns_name_free(keyname, mctx);
        isc_mem_put(mctx, kfetch, sizeof(dns_keyfetch_t));
        isc_mem_detach(&mctx);

        if (secroots != NULL)
                dns_keytable_detach(&secroots);

        free_needed = exit_check(zone);
        UNLOCK_ZONE(zone);
        if (free_needed)
                zone_free(zone);
}

/*
 * Refresh the data in the key zone.  Initiate a fetch to get new DNSKEY
 * records from the zone apex.
 */
static void
zone_refreshkeys(dns_zone_t *zone) {
        const char me[] = "zone_refreshkeys";
        isc_result_t result;
        dns_rriterator_t rrit;
        dns_db_t *db = NULL;
        dns_dbversion_t *ver = NULL;
        dns_diff_t diff;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_rdata_keydata_t kd;
        isc_stdtime_t now;
        isc_boolean_t commit = ISC_FALSE;
        isc_boolean_t fetching = ISC_FALSE, fetch_err = ISC_FALSE;

        ENTER;
        REQUIRE(zone->db != NULL);

        isc_stdtime_get(&now);

        LOCK_ZONE(zone);
        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING)) {
                isc_time_settoepoch(&zone->refreshkeytime);
                UNLOCK_ZONE(zone);
                return;
        }

        ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
        dns_db_attach(zone->db, &db);
        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);

        dns_diff_init(zone->mctx, &diff);

        CHECK(dns_db_newversion(db, &ver));

        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_REFRESHING);

        dns_rriterator_init(&rrit, db, ver, 0);
        for (result = dns_rriterator_first(&rrit);
             result == ISC_R_SUCCESS;
             result = dns_rriterator_nextrrset(&rrit)) {
                isc_stdtime_t timer = 0xffffffff;
                dns_name_t *name = NULL, *kname = NULL;
                dns_rdataset_t *kdset = NULL;
                dns_keyfetch_t *kfetch;
                isc_uint32_t ttl;

                dns_rriterator_current(&rrit, &name, &ttl, &kdset, NULL);
                if (kdset == NULL || kdset->type != dns_rdatatype_keydata ||
                    !dns_rdataset_isassociated(kdset))
                        continue;

                /*
                 * Scan the stored keys looking for ones that need
                 * removal or refreshing
                 */
                for (result = dns_rdataset_first(kdset);
                     result == ISC_R_SUCCESS;
                     result = dns_rdataset_next(kdset)) {
                        dns_rdata_reset(&rdata);
                        dns_rdataset_current(kdset, &rdata);
                        result = dns_rdata_tostruct(&rdata, &kd, NULL);
                        RUNTIME_CHECK(result == ISC_R_SUCCESS);

                        /* Removal timer expired? */
                        if (kd.removehd != 0 && kd.removehd < now) {
                                CHECK(update_one_rr(db, ver, &diff,
                                                    DNS_DIFFOP_DEL, name, ttl,
                                                    &rdata));
                                continue;
                        }

                        /* Acceptance timer expired? */
                        if (kd.addhd != 0 && kd.addhd < now)
                                timer = kd.addhd;

                        /* Or do we just need to refresh the keyset? */
                        if (timer > kd.refresh)
                                timer = kd.refresh;
                }

                if (timer > now)
                        continue;

                kfetch = isc_mem_get(zone->mctx, sizeof(dns_keyfetch_t));
                if (kfetch == NULL) {
                        fetch_err = ISC_TRUE;
                        goto failure;
                }

                zone->refreshkeycount++;
                kfetch->zone = zone;
                zone->irefs++;
                INSIST(zone->irefs != 0);
                dns_fixedname_init(&kfetch->name);
                kname = dns_fixedname_name(&kfetch->name);
                dns_name_dup(name, zone->mctx, kname);
                dns_rdataset_init(&kfetch->dnskeyset);
                dns_rdataset_init(&kfetch->dnskeysigset);
                dns_rdataset_init(&kfetch->keydataset);
                dns_rdataset_clone(kdset, &kfetch->keydataset);
                kfetch->db = NULL;
                dns_db_attach(db, &kfetch->db);
                kfetch->fetch = NULL;

                result = dns_resolver_createfetch(zone->view->resolver,
                                                  kname, dns_rdatatype_dnskey,
                                                  NULL, NULL, NULL,
                                                  DNS_FETCHOPT_NOVALIDATE,
                                                  zone->task,
                                                  keyfetch_done, kfetch,
                                                  &kfetch->dnskeyset,
                                                  &kfetch->dnskeysigset,
                                                  &kfetch->fetch);
                if (result == ISC_R_SUCCESS)
                        fetching = ISC_TRUE;
                else {
                        zone->refreshkeycount--;
                        zone->irefs--;
                        dns_db_detach(&kfetch->db);
                        dns_rdataset_disassociate(&kfetch->keydataset);
                        dns_name_free(kname, zone->mctx);
                        isc_mem_put(zone->mctx, kfetch, sizeof(dns_keyfetch_t));
                        dns_zone_log(zone, ISC_LOG_WARNING,
                                     "Failed to create fetch for "
                                     "DNSKEY update");
                        fetch_err = ISC_TRUE;
                }
        }
        if (!ISC_LIST_EMPTY(diff.tuples)) {
                CHECK(increment_soa_serial(db, ver, &diff, zone->mctx));
                CHECK(zone_journal(zone, &diff, "zone_refreshkeys"));
                commit = ISC_TRUE;
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_LOADED);
                zone_needdump(zone, 30);
        }

  failure:
        if (fetch_err) {
                /*
                 * Error during a key fetch; retry in an hour.
                 */
                isc_time_t timenow, timethen;
                char timebuf[80];

                TIME_NOW(&timenow);
                DNS_ZONE_TIME_ADD(&timenow, HOUR, &timethen);
                zone->refreshkeytime = timethen;
                zone_settimer(zone, &timenow);

                isc_time_formattimestamp(&zone->refreshkeytime, timebuf, 80);
                dns_zone_log(zone, ISC_LOG_DEBUG(1), "retry key refresh: %s",
                             timebuf);

                if (!fetching)
                        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_REFRESHING);
        }

        UNLOCK_ZONE(zone);

        dns_diff_clear(&diff);
        if (ver != NULL) {
                dns_rriterator_destroy(&rrit);
                dns_db_closeversion(db, &ver, commit);
        }
        dns_db_detach(&db);
}

static void
zone_maintenance(dns_zone_t *zone) {
        const char me[] = "zone_maintenance";
        isc_time_t now;
        isc_result_t result;
        isc_boolean_t dumping;

        REQUIRE(DNS_ZONE_VALID(zone));
        ENTER;

        /*
         * Configuring the view of this zone may have
         * failed, for example because the config file
         * had a syntax error.  In that case, the view
         * db or resolver will be NULL, and we had better not try
         * to do maintenance on it.
         */
        if (zone->view == NULL || zone->view->adb == NULL)
                return;

        TIME_NOW(&now);

        /*
         * Expire check.
         */
        switch (zone->type) {
        case dns_zone_slave:
        case dns_zone_stub:
                LOCK_ZONE(zone);
                if (isc_time_compare(&now, &zone->expiretime) >= 0 &&
                    DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED)) {
                        zone_expire(zone);
                        zone->refreshtime = now;
                }
                UNLOCK_ZONE(zone);
                break;
        default:
                break;
        }

        /*
         * Up to date check.
         */
        switch (zone->type) {
        case dns_zone_slave:
        case dns_zone_stub:
                if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DIALREFRESH) &&
                    isc_time_compare(&now, &zone->refreshtime) >= 0)
                        dns_zone_refresh(zone);
                break;
        default:
                break;
        }

        /*
         * Do we need to consolidate the backing store?
         */
        switch (zone->type) {
        case dns_zone_master:
        case dns_zone_slave:
        case dns_zone_key:
        case dns_zone_stub:
                LOCK_ZONE(zone);
                if (zone->masterfile != NULL &&
                    isc_time_compare(&now, &zone->dumptime) >= 0 &&
                    DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED) &&
                    DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDDUMP)) {
                        dumping = was_dumping(zone);
                } else
                        dumping = ISC_TRUE;
                UNLOCK_ZONE(zone);
                if (!dumping) {
                        result = zone_dump(zone, ISC_TRUE); /* task locked */
                        if (result != ISC_R_SUCCESS)
                                dns_zone_log(zone, ISC_LOG_WARNING,
                                             "dump failed: %s",
                                             dns_result_totext(result));
                }
                break;
        default:
                break;
        }

        /*
         * Do we need to refresh keys?
         */
        switch (zone->type) {
        case dns_zone_key:
                if (isc_time_compare(&now, &zone->refreshkeytime) >= 0 &&
                    DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED) &&
                    !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_REFRESHING))
                        zone_refreshkeys(zone);
                break;
        case dns_zone_master:
                if (!isc_time_isepoch(&zone->refreshkeytime) &&
                    isc_time_compare(&now, &zone->refreshkeytime) >= 0)
                        zone_rekey(zone);
        default:
                break;
        }

        switch (zone->type) {
        case dns_zone_master:
        case dns_zone_slave:
                /*
                 * Do we need to send out notify messages?
                 */
                if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDNOTIFY) &&
                    isc_time_compare(&now, &zone->notifytime) >= 0)
                        zone_notify(zone, &now);
                /*
                 * Do we need to sign/resign some RRsets?
                 */
                if (!isc_time_isepoch(&zone->signingtime) &&
                    isc_time_compare(&now, &zone->signingtime) >= 0)
                        zone_sign(zone);
                else if (!isc_time_isepoch(&zone->resigntime) &&
                    isc_time_compare(&now, &zone->resigntime) >= 0)
                        zone_resigninc(zone);
                else if (!isc_time_isepoch(&zone->nsec3chaintime) &&
                        isc_time_compare(&now, &zone->nsec3chaintime) >= 0)
                        zone_nsec3chain(zone);
                /*
                 * Do we need to issue a key expiry warning.
                 */
                if (!isc_time_isepoch(&zone->keywarntime) &&
                    isc_time_compare(&now, &zone->keywarntime) >= 0)
                        set_key_expiry_warning(zone, zone->key_expiry,
                                               isc_time_seconds(&now));
                break;
        default:
                break;
        }
        zone_settimer(zone, &now);
}

void
dns_zone_markdirty(dns_zone_t *zone) {

        LOCK_ZONE(zone);
        if (zone->type == dns_zone_master)
                set_resigntime(zone);   /* XXXMPA make separate call back */
        zone_needdump(zone, DNS_DUMP_DELAY);
        UNLOCK_ZONE(zone);
}

void
dns_zone_expire(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        zone_expire(zone);
        UNLOCK_ZONE(zone);
}

static void
zone_expire(dns_zone_t *zone) {
        /*
         * 'zone' locked by caller.
         */

        REQUIRE(LOCKED_ZONE(zone));

        dns_zone_log(zone, ISC_LOG_WARNING, "expired");

        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_EXPIRED);
        zone->refresh = DNS_ZONE_DEFAULTREFRESH;
        zone->retry = DNS_ZONE_DEFAULTRETRY;
        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_HAVETIMERS);
        zone_unload(zone);
}

void
dns_zone_refresh(dns_zone_t *zone) {
        isc_interval_t i;
        isc_uint32_t oldflags;
        unsigned int j;
        isc_result_t result;

        REQUIRE(DNS_ZONE_VALID(zone));

        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING))
                return;

        /*
         * Set DNS_ZONEFLG_REFRESH so that there is only one refresh operation
         * in progress at a time.
         */

        LOCK_ZONE(zone);
        oldflags = zone->flags;
        if (zone->masterscnt == 0) {
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOMASTERS);
                if ((oldflags & DNS_ZONEFLG_NOMASTERS) == 0)
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "cannot refresh: no masters");
                goto unlock;
        }
        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_REFRESH);
        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NOEDNS);
        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_USEALTXFRSRC);
        if ((oldflags & (DNS_ZONEFLG_REFRESH|DNS_ZONEFLG_LOADING)) != 0)
                goto unlock;

        /*
         * Set the next refresh time as if refresh check has failed.
         * Setting this to the retry time will do that.  XXXMLG
         * If we are successful it will be reset using zone->refresh.
         */
        isc_interval_set(&i, isc_random_jitter(zone->retry, zone->retry / 4),
                         0);
        result = isc_time_nowplusinterval(&zone->refreshtime, &i);
        if (result != ISC_R_SUCCESS)
                dns_zone_log(zone, ISC_LOG_WARNING,
                             "isc_time_nowplusinterval() failed: %s",
                             dns_result_totext(result));

        /*
         * When lacking user-specified timer values from the SOA,
         * do exponential backoff of the retry time up to a
         * maximum of six hours.
         */
        if (! DNS_ZONE_FLAG(zone, DNS_ZONEFLG_HAVETIMERS))
                zone->retry = ISC_MIN(zone->retry * 2, 6 * 3600);

        zone->curmaster = 0;
        for (j = 0; j < zone->masterscnt; j++)
                zone->mastersok[j] = ISC_FALSE;
        /* initiate soa query */
        queue_soa_query(zone);
 unlock:
        UNLOCK_ZONE(zone);
}

isc_result_t
dns_zone_flush(dns_zone_t *zone) {
        isc_result_t result = ISC_R_SUCCESS;
        isc_boolean_t dumping;

        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_FLUSH);
        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDDUMP) &&
            zone->masterfile != NULL) {
                result = ISC_R_ALREADYRUNNING;
                dumping = was_dumping(zone);
        } else
                dumping = ISC_TRUE;
        UNLOCK_ZONE(zone);
        if (!dumping)
                result = zone_dump(zone, ISC_FALSE);    /* Unknown task. */
        return (result);
}

isc_result_t
dns_zone_dump(dns_zone_t *zone) {
        isc_result_t result = ISC_R_ALREADYRUNNING;
        isc_boolean_t dumping;

        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        dumping = was_dumping(zone);
        UNLOCK_ZONE(zone);
        if (!dumping)
                result = zone_dump(zone, ISC_FALSE);    /* Unknown task. */
        return (result);
}

static void
zone_needdump(dns_zone_t *zone, unsigned int delay) {
        isc_time_t dumptime;
        isc_time_t now;

        /*
         * 'zone' locked by caller
         */

        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(LOCKED_ZONE(zone));

        /*
         * Do we have a place to dump to and are we loaded?
         */
        if (zone->masterfile == NULL ||
            DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED) == 0)
                return;

        TIME_NOW(&now);
        /* add some noise */
        DNS_ZONE_JITTER_ADD(&now, delay, &dumptime);

        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDDUMP);
        if (isc_time_isepoch(&zone->dumptime) ||
            isc_time_compare(&zone->dumptime, &dumptime) > 0)
                zone->dumptime = dumptime;
        if (zone->task != NULL)
                zone_settimer(zone, &now);
}

static void
dump_done(void *arg, isc_result_t result) {
        const char me[] = "dump_done";
        dns_zone_t *zone = arg;
        dns_db_t *db;
        dns_dbversion_t *version;
        isc_boolean_t again = ISC_FALSE;
        isc_boolean_t compact = ISC_FALSE;
        isc_uint32_t serial;
        isc_result_t tresult;

        REQUIRE(DNS_ZONE_VALID(zone));

        ENTER;

        if (result == ISC_R_SUCCESS && zone->journal != NULL &&
            zone->journalsize != -1) {

                /*
                 * We don't own these, zone->dctx must stay valid.
                 */
                db = dns_dumpctx_db(zone->dctx);
                version = dns_dumpctx_version(zone->dctx);

                tresult = dns_db_getsoaserial(db, version, &serial);
                /*
                 * Note: we are task locked here so we can test
                 * zone->xfr safely.
                 */
                if (tresult == ISC_R_SUCCESS && zone->xfr == NULL) {
                        tresult = dns_journal_compact(zone->mctx,
                                                      zone->journal,
                                                      serial,
                                                      zone->journalsize);
                        switch (tresult) {
                        case ISC_R_SUCCESS:
                        case ISC_R_NOSPACE:
                        case ISC_R_NOTFOUND:
                                dns_zone_log(zone, ISC_LOG_DEBUG(3),
                                             "dns_journal_compact: %s",
                                             dns_result_totext(tresult));
                                break;
                        default:
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "dns_journal_compact failed: %s",
                                             dns_result_totext(tresult));
                                break;
                        }
                } else if (tresult == ISC_R_SUCCESS) {
                        compact = ISC_TRUE;
                        zone->compact_serial = serial;
                }
        }

        LOCK_ZONE(zone);
        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_DUMPING);
        if (compact)
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDCOMPACT);
        if (result != ISC_R_SUCCESS && result != ISC_R_CANCELED) {
                /*
                 * Try again in a short while.
                 */
                zone_needdump(zone, DNS_DUMP_DELAY);
        } else if (result == ISC_R_SUCCESS &&
                   DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FLUSH) &&
                   DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDDUMP) &&
                   DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED)) {
                DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NEEDDUMP);
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_DUMPING);
                isc_time_settoepoch(&zone->dumptime);
                again = ISC_TRUE;
        } else if (result == ISC_R_SUCCESS)
                DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_FLUSH);

        if (zone->dctx != NULL)
                dns_dumpctx_detach(&zone->dctx);
        zonemgr_putio(&zone->writeio);
        UNLOCK_ZONE(zone);
        if (again)
                (void)zone_dump(zone, ISC_FALSE);
        dns_zone_idetach(&zone);
}

static isc_result_t
zone_dump(dns_zone_t *zone, isc_boolean_t compact) {
        const char me[] = "zone_dump";
        isc_result_t result;
        dns_dbversion_t *version = NULL;
        isc_boolean_t again;
        dns_db_t *db = NULL;
        char *masterfile = NULL;
        dns_masterformat_t masterformat = dns_masterformat_none;

/*
 * 'compact' MUST only be set if we are task locked.
 */

        REQUIRE(DNS_ZONE_VALID(zone));
        ENTER;

 redo:
        ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
        if (zone->db != NULL)
                dns_db_attach(zone->db, &db);
        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
        LOCK_ZONE(zone);
        if (zone->masterfile != NULL) {
                masterfile = isc_mem_strdup(zone->mctx, zone->masterfile);
                masterformat = zone->masterformat;
        }
        UNLOCK_ZONE(zone);
        if (db == NULL) {
                result = DNS_R_NOTLOADED;
                goto fail;
        }
        if (masterfile == NULL) {
                result = DNS_R_NOMASTERFILE;
                goto fail;
        }

        if (compact && zone->type != dns_zone_stub) {
                dns_zone_t *dummy = NULL;
                LOCK_ZONE(zone);
                zone_iattach(zone, &dummy);
                result = zonemgr_getio(zone->zmgr, ISC_FALSE, zone->task,
                                       zone_gotwritehandle, zone,
                                       &zone->writeio);
                if (result != ISC_R_SUCCESS)
                        zone_idetach(&dummy);
                else
                        result = DNS_R_CONTINUE;
                UNLOCK_ZONE(zone);
        } else {
                dns_db_currentversion(db, &version);
                result = dns_master_dump2(zone->mctx, db, version,
                                          &dns_master_style_default,
                                          masterfile, masterformat);
                dns_db_closeversion(db, &version, ISC_FALSE);
        }
 fail:
        if (db != NULL)
                dns_db_detach(&db);
        if (masterfile != NULL)
                isc_mem_free(zone->mctx, masterfile);
        masterfile = NULL;

        if (result == DNS_R_CONTINUE)
                return (ISC_R_SUCCESS); /* XXXMPA */

        again = ISC_FALSE;
        LOCK_ZONE(zone);
        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_DUMPING);
        if (result != ISC_R_SUCCESS) {
                /*
                 * Try again in a short while.
                 */
                zone_needdump(zone, DNS_DUMP_DELAY);
        } else if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FLUSH) &&
                   DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDDUMP) &&
                   DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED)) {
                DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NEEDDUMP);
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_DUMPING);
                isc_time_settoepoch(&zone->dumptime);
                again = ISC_TRUE;
        } else
                DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_FLUSH);
        UNLOCK_ZONE(zone);
        if (again)
                goto redo;

        return (result);
}

static isc_result_t
dumptostream(dns_zone_t *zone, FILE *fd, const dns_master_style_t *style,
             dns_masterformat_t format)
{
        isc_result_t result;
        dns_dbversion_t *version = NULL;
        dns_db_t *db = NULL;

        REQUIRE(DNS_ZONE_VALID(zone));

        ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
        if (zone->db != NULL)
                dns_db_attach(zone->db, &db);
        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
        if (db == NULL)
                return (DNS_R_NOTLOADED);

        dns_db_currentversion(db, &version);
        result = dns_master_dumptostream2(zone->mctx, db, version, style,
                                          format, fd);
        dns_db_closeversion(db, &version, ISC_FALSE);
        dns_db_detach(&db);
        return (result);
}

isc_result_t
dns_zone_dumptostream2(dns_zone_t *zone, FILE *fd, dns_masterformat_t format,
                       const dns_master_style_t *style) {
        return dumptostream(zone, fd, style, format);
}

isc_result_t
dns_zone_dumptostream(dns_zone_t *zone, FILE *fd) {
        return dumptostream(zone, fd, &dns_master_style_default,
                            dns_masterformat_text);
}

isc_result_t
dns_zone_fulldumptostream(dns_zone_t *zone, FILE *fd) {
        return dumptostream(zone, fd, &dns_master_style_full,
                            dns_masterformat_text);
}

void
dns_zone_unload(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        zone_unload(zone);
        UNLOCK_ZONE(zone);
}

static void
notify_cancel(dns_zone_t *zone) {
        dns_notify_t *notify;

        /*
         * 'zone' locked by caller.
         */

        REQUIRE(LOCKED_ZONE(zone));

        for (notify = ISC_LIST_HEAD(zone->notifies);
             notify != NULL;
             notify = ISC_LIST_NEXT(notify, link)) {
                if (notify->find != NULL)
                        dns_adb_cancelfind(notify->find);
                if (notify->request != NULL)
                        dns_request_cancel(notify->request);
        }
}

static void
forward_cancel(dns_zone_t *zone) {
        dns_forward_t *forward;

        /*
         * 'zone' locked by caller.
         */

        REQUIRE(LOCKED_ZONE(zone));

        for (forward = ISC_LIST_HEAD(zone->forwards);
             forward != NULL;
             forward = ISC_LIST_NEXT(forward, link)) {
                if (forward->request != NULL)
                        dns_request_cancel(forward->request);
        }
}

static void
zone_unload(dns_zone_t *zone) {

        /*
         * 'zone' locked by caller.
         */

        REQUIRE(LOCKED_ZONE(zone));

        if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FLUSH) ||
            !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DUMPING)) {
                if (zone->writeio != NULL)
                        zonemgr_cancelio(zone->writeio);

                if (zone->dctx != NULL)
                        dns_dumpctx_cancel(zone->dctx);
        }
        ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_write);
        zone_detachdb(zone);
        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_write);
        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_LOADED);
        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NEEDDUMP);
}

void
dns_zone_setminrefreshtime(dns_zone_t *zone, isc_uint32_t val) {
        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(val > 0);

        zone->minrefresh = val;
}

void
dns_zone_setmaxrefreshtime(dns_zone_t *zone, isc_uint32_t val) {
        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(val > 0);

        zone->maxrefresh = val;
}

void
dns_zone_setminretrytime(dns_zone_t *zone, isc_uint32_t val) {
        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(val > 0);

        zone->minretry = val;
}

void
dns_zone_setmaxretrytime(dns_zone_t *zone, isc_uint32_t val) {
        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(val > 0);

        zone->maxretry = val;
}

static isc_boolean_t
notify_isqueued(dns_zone_t *zone, dns_name_t *name, isc_sockaddr_t *addr) {
        dns_notify_t *notify;

        for (notify = ISC_LIST_HEAD(zone->notifies);
             notify != NULL;
             notify = ISC_LIST_NEXT(notify, link)) {
                if (notify->request != NULL)
                        continue;
                if (name != NULL && dns_name_dynamic(&notify->ns) &&
                    dns_name_equal(name, &notify->ns))
                        return (ISC_TRUE);
                if (addr != NULL && isc_sockaddr_equal(addr, &notify->dst))
                        return (ISC_TRUE);
        }
        return (ISC_FALSE);
}

static isc_boolean_t
notify_isself(dns_zone_t *zone, isc_sockaddr_t *dst) {
        dns_tsigkey_t *key = NULL;
        isc_sockaddr_t src;
        isc_sockaddr_t any;
        isc_boolean_t isself;
        isc_netaddr_t dstaddr;
        isc_result_t result;

        if (zone->view == NULL || zone->isself == NULL)
                return (ISC_FALSE);

        switch (isc_sockaddr_pf(dst)) {
        case PF_INET:
                src = zone->notifysrc4;
                isc_sockaddr_any(&any);
                break;
        case PF_INET6:
                src = zone->notifysrc6;
                isc_sockaddr_any6(&any);
                break;
        default:
                return (ISC_FALSE);
        }

        /*
         * When sending from any the kernel will assign a source address
         * that matches the destination address.
         */
        if (isc_sockaddr_eqaddr(&any, &src))
                src = *dst;

        isc_netaddr_fromsockaddr(&dstaddr, dst);
        result = dns_view_getpeertsig(zone->view, &dstaddr, &key);
        if (result != ISC_R_SUCCESS && result != ISC_R_NOTFOUND)
                return (ISC_FALSE);
        isself = (zone->isself)(zone->view, key, &src, dst, zone->rdclass,
                                zone->isselfarg);
        if (key != NULL)
                dns_tsigkey_detach(&key);
        return (isself);
}

static void
notify_destroy(dns_notify_t *notify, isc_boolean_t locked) {
        isc_mem_t *mctx;

        /*
         * Caller holds zone lock.
         */
        REQUIRE(DNS_NOTIFY_VALID(notify));

        if (notify->zone != NULL) {
                if (!locked)
                        LOCK_ZONE(notify->zone);
                REQUIRE(LOCKED_ZONE(notify->zone));
                if (ISC_LINK_LINKED(notify, link))
                        ISC_LIST_UNLINK(notify->zone->notifies, notify, link);
                if (!locked)
                        UNLOCK_ZONE(notify->zone);
                if (locked)
                        zone_idetach(&notify->zone);
                else
                        dns_zone_idetach(&notify->zone);
        }
        if (notify->find != NULL)
                dns_adb_destroyfind(&notify->find);
        if (notify->request != NULL)
                dns_request_destroy(&notify->request);
        if (dns_name_dynamic(&notify->ns))
                dns_name_free(&notify->ns, notify->mctx);
        mctx = notify->mctx;
        isc_mem_put(notify->mctx, notify, sizeof(*notify));
        isc_mem_detach(&mctx);
}

static isc_result_t
notify_create(isc_mem_t *mctx, unsigned int flags, dns_notify_t **notifyp) {
        dns_notify_t *notify;

        REQUIRE(notifyp != NULL && *notifyp == NULL);

        notify = isc_mem_get(mctx, sizeof(*notify));
        if (notify == NULL)
                return (ISC_R_NOMEMORY);

        notify->mctx = NULL;
        isc_mem_attach(mctx, &notify->mctx);
        notify->flags = flags;
        notify->zone = NULL;
        notify->find = NULL;
        notify->request = NULL;
        isc_sockaddr_any(&notify->dst);
        dns_name_init(&notify->ns, NULL);
        ISC_LINK_INIT(notify, link);
        notify->magic = NOTIFY_MAGIC;
        *notifyp = notify;
        return (ISC_R_SUCCESS);
}

/*
 * XXXAG should check for DNS_ZONEFLG_EXITING
 */
static void
process_adb_event(isc_task_t *task, isc_event_t *ev) {
        dns_notify_t *notify;
        isc_eventtype_t result;

        UNUSED(task);

        notify = ev->ev_arg;
        REQUIRE(DNS_NOTIFY_VALID(notify));
        INSIST(task == notify->zone->task);
        result = ev->ev_type;
        isc_event_free(&ev);
        if (result == DNS_EVENT_ADBMOREADDRESSES) {
                dns_adb_destroyfind(&notify->find);
                notify_find_address(notify);
                return;
        }
        if (result == DNS_EVENT_ADBNOMOREADDRESSES) {
                LOCK_ZONE(notify->zone);
                notify_send(notify);
                UNLOCK_ZONE(notify->zone);
        }
        notify_destroy(notify, ISC_FALSE);
}

static void
notify_find_address(dns_notify_t *notify) {
        isc_result_t result;
        unsigned int options;

        REQUIRE(DNS_NOTIFY_VALID(notify));
        options = DNS_ADBFIND_WANTEVENT | DNS_ADBFIND_INET |
                  DNS_ADBFIND_INET6 | DNS_ADBFIND_RETURNLAME;

        if (notify->zone->view->adb == NULL)
                goto destroy;

        result = dns_adb_createfind(notify->zone->view->adb,
                                    notify->zone->task,
                                    process_adb_event, notify,
                                    &notify->ns, dns_rootname, 0,
                                    options, 0, NULL,
                                    notify->zone->view->dstport,
                                    &notify->find);

        /* Something failed? */
        if (result != ISC_R_SUCCESS)
                goto destroy;

        /* More addresses pending? */
        if ((notify->find->options & DNS_ADBFIND_WANTEVENT) != 0)
                return;

        /* We have as many addresses as we can get. */
        LOCK_ZONE(notify->zone);
        notify_send(notify);
        UNLOCK_ZONE(notify->zone);

 destroy:
        notify_destroy(notify, ISC_FALSE);
}


static isc_result_t
notify_send_queue(dns_notify_t *notify) {
        isc_event_t *e;
        isc_result_t result;

        e = isc_event_allocate(notify->mctx, NULL,
                               DNS_EVENT_NOTIFYSENDTOADDR,
                               notify_send_toaddr,
                               notify, sizeof(isc_event_t));
        if (e == NULL)
                return (ISC_R_NOMEMORY);
        e->ev_arg = notify;
        e->ev_sender = NULL;
        result = isc_ratelimiter_enqueue(notify->zone->zmgr->rl,
                                         notify->zone->task, &e);
        if (result != ISC_R_SUCCESS)
                isc_event_free(&e);
        return (result);
}

static void
notify_send_toaddr(isc_task_t *task, isc_event_t *event) {
        dns_notify_t *notify;
        isc_result_t result;
        dns_message_t *message = NULL;
        isc_netaddr_t dstip;
        dns_tsigkey_t *key = NULL;
        char addrbuf[ISC_SOCKADDR_FORMATSIZE];
        isc_sockaddr_t src;
        int timeout;
        isc_boolean_t have_notifysource = ISC_FALSE;

        notify = event->ev_arg;
        REQUIRE(DNS_NOTIFY_VALID(notify));

        UNUSED(task);

        LOCK_ZONE(notify->zone);

        if (DNS_ZONE_FLAG(notify->zone, DNS_ZONEFLG_LOADED) == 0) {
                result = ISC_R_CANCELED;
                goto cleanup;
        }

        if ((event->ev_attributes & ISC_EVENTATTR_CANCELED) != 0 ||
            DNS_ZONE_FLAG(notify->zone, DNS_ZONEFLG_EXITING) ||
            notify->zone->view->requestmgr == NULL ||
            notify->zone->db == NULL) {
                result = ISC_R_CANCELED;
                goto cleanup;
        }

        /*
         * The raw IPv4 address should also exist.  Don't send to the
         * mapped form.
         */
        if (isc_sockaddr_pf(&notify->dst) == PF_INET6 &&
            IN6_IS_ADDR_V4MAPPED(&notify->dst.type.sin6.sin6_addr)) {
                isc_sockaddr_format(&notify->dst, addrbuf, sizeof(addrbuf));
                notify_log(notify->zone, ISC_LOG_DEBUG(3),
                           "notify: ignoring IPv6 mapped IPV4 address: %s",
                           addrbuf);
                result = ISC_R_CANCELED;
                goto cleanup;
        }

        result = notify_createmessage(notify->zone, notify->flags, &message);
        if (result != ISC_R_SUCCESS)
                goto cleanup;

        isc_netaddr_fromsockaddr(&dstip, &notify->dst);
        isc_sockaddr_format(&notify->dst, addrbuf, sizeof(addrbuf));
        result = dns_view_getpeertsig(notify->zone->view, &dstip, &key);
        if (result != ISC_R_SUCCESS && result != ISC_R_NOTFOUND) {
                notify_log(notify->zone, ISC_LOG_ERROR, "NOTIFY to %s not "
                           "sent. Peer TSIG key lookup failure.", addrbuf);
                goto cleanup_message;
        }

        notify_log(notify->zone, ISC_LOG_DEBUG(3), "sending notify to %s",
                   addrbuf);
        if (notify->zone->view->peers != NULL) {
                dns_peer_t *peer = NULL;
                result = dns_peerlist_peerbyaddr(notify->zone->view->peers,
                                                 &dstip, &peer);
                if (result == ISC_R_SUCCESS) {
                        result = dns_peer_getnotifysource(peer, &src);
                        if (result == ISC_R_SUCCESS)
                                have_notifysource = ISC_TRUE;
                }
        }
        switch (isc_sockaddr_pf(&notify->dst)) {
        case PF_INET:
                if (!have_notifysource)
                        src = notify->zone->notifysrc4;
                break;
        case PF_INET6:
                if (!have_notifysource)
                        src = notify->zone->notifysrc6;
                break;
        default:
                result = ISC_R_NOTIMPLEMENTED;
                goto cleanup_key;
        }
        timeout = 15;
        if (DNS_ZONE_FLAG(notify->zone, DNS_ZONEFLG_DIALNOTIFY))
                timeout = 30;
        result = dns_request_createvia2(notify->zone->view->requestmgr,
                                        message, &src, &notify->dst, 0, key,
                                        timeout * 3, timeout,
                                        notify->zone->task, notify_done,
                                        notify, &notify->request);
        if (result == ISC_R_SUCCESS) {
                if (isc_sockaddr_pf(&notify->dst) == AF_INET) {
                        inc_stats(notify->zone,
                                  dns_zonestatscounter_notifyoutv4);
                } else {
                        inc_stats(notify->zone,
                                  dns_zonestatscounter_notifyoutv6);
                }
        }

 cleanup_key:
        if (key != NULL)
                dns_tsigkey_detach(&key);
 cleanup_message:
        dns_message_destroy(&message);
 cleanup:
        UNLOCK_ZONE(notify->zone);
        if (result != ISC_R_SUCCESS)
                notify_destroy(notify, ISC_FALSE);
        isc_event_free(&event);
}

static void
notify_send(dns_notify_t *notify) {
        dns_adbaddrinfo_t *ai;
        isc_sockaddr_t dst;
        isc_result_t result;
        dns_notify_t *new = NULL;

        /*
         * Zone lock held by caller.
         */
        REQUIRE(DNS_NOTIFY_VALID(notify));
        REQUIRE(LOCKED_ZONE(notify->zone));

        for (ai = ISC_LIST_HEAD(notify->find->list);
             ai != NULL;
             ai = ISC_LIST_NEXT(ai, publink)) {
                dst = ai->sockaddr;
                if (notify_isqueued(notify->zone, NULL, &dst))
                        continue;
                if (notify_isself(notify->zone, &dst))
                        continue;
                new = NULL;
                result = notify_create(notify->mctx,
                                       (notify->flags & DNS_NOTIFY_NOSOA),
                                       &new);
                if (result != ISC_R_SUCCESS)
                        goto cleanup;
                zone_iattach(notify->zone, &new->zone);
                ISC_LIST_APPEND(new->zone->notifies, new, link);
                new->dst = dst;
                result = notify_send_queue(new);
                if (result != ISC_R_SUCCESS)
                        goto cleanup;
                new = NULL;
        }

 cleanup:
        if (new != NULL)
                notify_destroy(new, ISC_TRUE);
}

void
dns_zone_notify(dns_zone_t *zone) {
        isc_time_t now;

        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDNOTIFY);

        TIME_NOW(&now);
        zone_settimer(zone, &now);
        UNLOCK_ZONE(zone);
}

static void
zone_notify(dns_zone_t *zone, isc_time_t *now) {
        dns_dbnode_t *node = NULL;
        dns_db_t *zonedb = NULL;
        dns_dbversion_t *version = NULL;
        dns_name_t *origin = NULL;
        dns_name_t master;
        dns_rdata_ns_t ns;
        dns_rdata_soa_t soa;
        isc_uint32_t serial;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_rdataset_t nsrdset;
        dns_rdataset_t soardset;
        isc_result_t result;
        dns_notify_t *notify = NULL;
        unsigned int i;
        isc_sockaddr_t dst;
        isc_boolean_t isqueued;
        dns_notifytype_t notifytype;
        unsigned int flags = 0;
        isc_boolean_t loggednotify = ISC_FALSE;

        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NEEDNOTIFY);
        notifytype = zone->notifytype;
        DNS_ZONE_TIME_ADD(now, zone->notifydelay, &zone->notifytime);
        UNLOCK_ZONE(zone);

        if (! DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED))
                return;

        if (notifytype == dns_notifytype_no)
                return;

        if (notifytype == dns_notifytype_masteronly &&
            zone->type != dns_zone_master)
                return;

        origin = &zone->origin;

        /*
         * If the zone is dialup we are done as we don't want to send
         * the current soa so as to force a refresh query.
         */
        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DIALNOTIFY))
                flags |= DNS_NOTIFY_NOSOA;

        /*
         * Get SOA RRset.
         */
        ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
        if (zone->db != NULL)
                dns_db_attach(zone->db, &zonedb);
        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
        if (zonedb == NULL)
                return;
        dns_db_currentversion(zonedb, &version);
        result = dns_db_findnode(zonedb, origin, ISC_FALSE, &node);
        if (result != ISC_R_SUCCESS)
                goto cleanup1;

        dns_rdataset_init(&soardset);
        result = dns_db_findrdataset(zonedb, node, version, dns_rdatatype_soa,
                                     dns_rdatatype_none, 0, &soardset, NULL);
        if (result != ISC_R_SUCCESS)
                goto cleanup2;

        /*
         * Find serial and master server's name.
         */
        dns_name_init(&master, NULL);
        result = dns_rdataset_first(&soardset);
        if (result != ISC_R_SUCCESS)
                goto cleanup3;
        dns_rdataset_current(&soardset, &rdata);
        result = dns_rdata_tostruct(&rdata, &soa, NULL);
        RUNTIME_CHECK(result == ISC_R_SUCCESS);
        dns_rdata_reset(&rdata);
        result = dns_name_dup(&soa.origin, zone->mctx, &master);
        serial = soa.serial;
        dns_rdataset_disassociate(&soardset);
        if (result != ISC_R_SUCCESS)
                goto cleanup3;

        /*
         * Enqueue notify requests for 'also-notify' servers.
         */
        LOCK_ZONE(zone);
        for (i = 0; i < zone->notifycnt; i++) {
                dst = zone->notify[i];
                if (notify_isqueued(zone, NULL, &dst))
                        continue;
                result = notify_create(zone->mctx, flags, &notify);
                if (result != ISC_R_SUCCESS)
                        continue;
                zone_iattach(zone, &notify->zone);
                notify->dst = dst;
                ISC_LIST_APPEND(zone->notifies, notify, link);
                result = notify_send_queue(notify);
                if (result != ISC_R_SUCCESS)
                        notify_destroy(notify, ISC_TRUE);
                if (!loggednotify) {
                        notify_log(zone, ISC_LOG_INFO,
                                   "sending notifies (serial %u)",
                                   serial);
                        loggednotify = ISC_TRUE;
                }
                notify = NULL;
        }
        UNLOCK_ZONE(zone);

        if (notifytype == dns_notifytype_explicit)
                goto cleanup3;

        /*
         * Process NS RRset to generate notifies.
         */

        dns_rdataset_init(&nsrdset);
        result = dns_db_findrdataset(zonedb, node, version, dns_rdatatype_ns,
                                     dns_rdatatype_none, 0, &nsrdset, NULL);
        if (result != ISC_R_SUCCESS)
                goto cleanup3;

        result = dns_rdataset_first(&nsrdset);
        while (result == ISC_R_SUCCESS) {
                dns_rdataset_current(&nsrdset, &rdata);
                result = dns_rdata_tostruct(&rdata, &ns, NULL);
                RUNTIME_CHECK(result == ISC_R_SUCCESS);
                dns_rdata_reset(&rdata);
                /*
                 * Don't notify the master server unless explicitly
                 * configured to do so.
                 */
                if (!DNS_ZONE_OPTION(zone, DNS_ZONEOPT_NOTIFYTOSOA) &&
                    dns_name_compare(&master, &ns.name) == 0) {
                        result = dns_rdataset_next(&nsrdset);
                        continue;
                }

                if (!loggednotify) {
                        notify_log(zone, ISC_LOG_INFO,
                                   "sending notifies (serial %u)",
                                   serial);
                        loggednotify = ISC_TRUE;
                }

                LOCK_ZONE(zone);
                isqueued = notify_isqueued(zone, &ns.name, NULL);
                UNLOCK_ZONE(zone);
                if (isqueued) {
                        result = dns_rdataset_next(&nsrdset);
                        continue;
                }
                result = notify_create(zone->mctx, flags, &notify);
                if (result != ISC_R_SUCCESS)
                        continue;
                dns_zone_iattach(zone, &notify->zone);
                result = dns_name_dup(&ns.name, zone->mctx, &notify->ns);
                if (result != ISC_R_SUCCESS) {
                        LOCK_ZONE(zone);
                        notify_destroy(notify, ISC_TRUE);
                        UNLOCK_ZONE(zone);
                        continue;
                }
                LOCK_ZONE(zone);
                ISC_LIST_APPEND(zone->notifies, notify, link);
                UNLOCK_ZONE(zone);
                notify_find_address(notify);
                notify = NULL;
                result = dns_rdataset_next(&nsrdset);
        }
        dns_rdataset_disassociate(&nsrdset);

 cleanup3:
        if (dns_name_dynamic(&master))
                dns_name_free(&master, zone->mctx);
 cleanup2:
        dns_db_detachnode(zonedb, &node);
 cleanup1:
        dns_db_closeversion(zonedb, &version, ISC_FALSE);
        dns_db_detach(&zonedb);
}

/***
 *** Private
 ***/

static inline isc_result_t
save_nsrrset(dns_message_t *message, dns_name_t *name,
             dns_db_t *db, dns_dbversion_t *version)
{
        dns_rdataset_t *nsrdataset = NULL;
        dns_rdataset_t *rdataset = NULL;
        dns_dbnode_t *node = NULL;
        dns_rdata_ns_t ns;
        isc_result_t result;
        dns_rdata_t rdata = DNS_RDATA_INIT;

        /*
         * Extract NS RRset from message.
         */
        result = dns_message_findname(message, DNS_SECTION_ANSWER, name,
                                      dns_rdatatype_ns, dns_rdatatype_none,
                                      NULL, &nsrdataset);
        if (result != ISC_R_SUCCESS)
                goto fail;

        /*
         * Add NS rdataset.
         */
        result = dns_db_findnode(db, name, ISC_TRUE, &node);
        if (result != ISC_R_SUCCESS)
                goto fail;
        result = dns_db_addrdataset(db, node, version, 0,
                                    nsrdataset, 0, NULL);
        dns_db_detachnode(db, &node);
        if (result != ISC_R_SUCCESS)
                goto fail;
        /*
         * Add glue rdatasets.
         */
        for (result = dns_rdataset_first(nsrdataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(nsrdataset)) {
                dns_rdataset_current(nsrdataset, &rdata);
                result = dns_rdata_tostruct(&rdata, &ns, NULL);
                RUNTIME_CHECK(result == ISC_R_SUCCESS);
                dns_rdata_reset(&rdata);
                if (!dns_name_issubdomain(&ns.name, name))
                        continue;
                rdataset = NULL;
                result = dns_message_findname(message, DNS_SECTION_ADDITIONAL,
                                              &ns.name, dns_rdatatype_aaaa,
                                              dns_rdatatype_none, NULL,
                                              &rdataset);
                if (result == ISC_R_SUCCESS) {
                        result = dns_db_findnode(db, &ns.name,
                                                 ISC_TRUE, &node);
                        if (result != ISC_R_SUCCESS)
                                goto fail;
                        result = dns_db_addrdataset(db, node, version, 0,
                                                    rdataset, 0, NULL);
                        dns_db_detachnode(db, &node);
                        if (result != ISC_R_SUCCESS)
                                goto fail;
                }
                rdataset = NULL;
                result = dns_message_findname(message, DNS_SECTION_ADDITIONAL,
                                              &ns.name, dns_rdatatype_a,
                                              dns_rdatatype_none, NULL,
                                              &rdataset);
                if (result == ISC_R_SUCCESS) {
                        result = dns_db_findnode(db, &ns.name,
                                                 ISC_TRUE, &node);
                        if (result != ISC_R_SUCCESS)
                                goto fail;
                        result = dns_db_addrdataset(db, node, version, 0,
                                                    rdataset, 0, NULL);
                        dns_db_detachnode(db, &node);
                        if (result != ISC_R_SUCCESS)
                                goto fail;
                }
        }
        if (result != ISC_R_NOMORE)
                goto fail;

        return (ISC_R_SUCCESS);

fail:
        return (result);
}

static void
stub_callback(isc_task_t *task, isc_event_t *event) {
        const char me[] = "stub_callback";
        dns_requestevent_t *revent = (dns_requestevent_t *)event;
        dns_stub_t *stub = NULL;
        dns_message_t *msg = NULL;
        dns_zone_t *zone = NULL;
        char master[ISC_SOCKADDR_FORMATSIZE];
        char source[ISC_SOCKADDR_FORMATSIZE];
        isc_uint32_t nscnt, cnamecnt, refresh, retry, expire;
        isc_result_t result;
        isc_time_t now;
        isc_boolean_t exiting = ISC_FALSE;
        isc_interval_t i;
        unsigned int j;

        stub = revent->ev_arg;
        INSIST(DNS_STUB_VALID(stub));

        UNUSED(task);

        zone = stub->zone;

        ENTER;

        TIME_NOW(&now);

        LOCK_ZONE(zone);

        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING)) {
                zone_debuglog(zone, me, 1, "exiting");
                exiting = ISC_TRUE;
                goto next_master;
        }

        isc_sockaddr_format(&zone->masteraddr, master, sizeof(master));
        isc_sockaddr_format(&zone->sourceaddr, source, sizeof(source));

        if (revent->result != ISC_R_SUCCESS) {
                if (revent->result == ISC_R_TIMEDOUT &&
                    !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOEDNS)) {
                        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOEDNS);
                        dns_zone_log(zone, ISC_LOG_DEBUG(1),
                                     "refreshing stub: timeout retrying "
                                     " without EDNS master %s (source %s)",
                                     master, source);
                        goto same_master;
                }
                dns_zonemgr_unreachableadd(zone->zmgr, &zone->masteraddr,
                                           &zone->sourceaddr, &now);
                dns_zone_log(zone, ISC_LOG_INFO,
                             "could not refresh stub from master %s"
                             " (source %s): %s", master, source,
                             dns_result_totext(revent->result));
                goto next_master;
        }

        result = dns_message_create(zone->mctx, DNS_MESSAGE_INTENTPARSE, &msg);
        if (result != ISC_R_SUCCESS)
                goto next_master;

        result = dns_request_getresponse(revent->request, msg, 0);
        if (result != ISC_R_SUCCESS)
                goto next_master;

        /*
         * Unexpected rcode.
         */
        if (msg->rcode != dns_rcode_noerror) {
                char rcode[128];
                isc_buffer_t rb;

                isc_buffer_init(&rb, rcode, sizeof(rcode));
                (void)dns_rcode_totext(msg->rcode, &rb);

                if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOEDNS) &&
                    (msg->rcode == dns_rcode_servfail ||
                     msg->rcode == dns_rcode_notimp ||
                     msg->rcode == dns_rcode_formerr)) {
                        dns_zone_log(zone, ISC_LOG_DEBUG(1),
                                     "refreshing stub: rcode (%.*s) retrying "
                                     "without EDNS master %s (source %s)",
                                     (int)rb.used, rcode, master, source);
                        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOEDNS);
                        goto same_master;
                }

                dns_zone_log(zone, ISC_LOG_INFO,
                             "refreshing stub: "
                             "unexpected rcode (%.*s) from %s (source %s)",
                             (int)rb.used, rcode, master, source);
                goto next_master;
        }

        /*
         * We need complete messages.
         */
        if ((msg->flags & DNS_MESSAGEFLAG_TC) != 0) {
                if (dns_request_usedtcp(revent->request)) {
                        dns_zone_log(zone, ISC_LOG_INFO,
                                     "refreshing stub: truncated TCP "
                                     "response from master %s (source %s)",
                                     master, source);
                        goto next_master;
                }
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_USEVC);
                goto same_master;
        }

        /*
         * If non-auth log and next master.
         */
        if ((msg->flags & DNS_MESSAGEFLAG_AA) == 0) {
                dns_zone_log(zone, ISC_LOG_INFO, "refreshing stub: "
                             "non-authoritative answer from "
                             "master %s (source %s)", master, source);
                goto next_master;
        }

        /*
         * Sanity checks.
         */
        cnamecnt = message_count(msg, DNS_SECTION_ANSWER, dns_rdatatype_cname);
        nscnt = message_count(msg, DNS_SECTION_ANSWER, dns_rdatatype_ns);

        if (cnamecnt != 0) {
                dns_zone_log(zone, ISC_LOG_INFO,
                             "refreshing stub: unexpected CNAME response "
                             "from master %s (source %s)", master, source);
                goto next_master;
        }

        if (nscnt == 0) {
                dns_zone_log(zone, ISC_LOG_INFO,
                             "refreshing stub: no NS records in response "
                             "from master %s (source %s)", master, source);
                goto next_master;
        }

        /*
         * Save answer.
         */
        result = save_nsrrset(msg, &zone->origin, stub->db, stub->version);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_INFO,
                             "refreshing stub: unable to save NS records "
                             "from master %s (source %s)", master, source);
                goto next_master;
        }

        /*
         * Tidy up.
         */
        dns_db_closeversion(stub->db, &stub->version, ISC_TRUE);
        ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_write);
        if (zone->db == NULL)
                zone_attachdb(zone, stub->db);
        result = zone_get_from_db(zone, zone->db, NULL, NULL, NULL, &refresh,
                                  &retry, &expire, NULL, NULL);
        if (result == ISC_R_SUCCESS) {
                zone->refresh = RANGE(refresh, zone->minrefresh,
                                      zone->maxrefresh);
                zone->retry = RANGE(retry, zone->minretry, zone->maxretry);
                zone->expire = RANGE(expire, zone->refresh + zone->retry,
                                     DNS_MAX_EXPIRE);
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_HAVETIMERS);
        }
        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_write);
        dns_db_detach(&stub->db);

        dns_message_destroy(&msg);
        isc_event_free(&event);
        dns_request_destroy(&zone->request);

        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_REFRESH);
        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_LOADED);
        DNS_ZONE_JITTER_ADD(&now, zone->refresh, &zone->refreshtime);
        isc_interval_set(&i, zone->expire, 0);
        DNS_ZONE_TIME_ADD(&now, zone->expire, &zone->expiretime);

        if (zone->masterfile != NULL)
                zone_needdump(zone, 0);

        zone_settimer(zone, &now);
        goto free_stub;

 next_master:
        if (stub->version != NULL)
                dns_db_closeversion(stub->db, &stub->version, ISC_FALSE);
        if (stub->db != NULL)
                dns_db_detach(&stub->db);
        if (msg != NULL)
                dns_message_destroy(&msg);
        isc_event_free(&event);
        dns_request_destroy(&zone->request);
        /*
         * Skip to next failed / untried master.
         */
        do {
                zone->curmaster++;
        } while (zone->curmaster < zone->masterscnt &&
                 zone->mastersok[zone->curmaster]);
        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NOEDNS);
        if (exiting || zone->curmaster >= zone->masterscnt) {
                isc_boolean_t done = ISC_TRUE;
                if (!exiting &&
                    DNS_ZONE_OPTION(zone, DNS_ZONEOPT_USEALTXFRSRC) &&
                    !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_USEALTXFRSRC)) {
                        /*
                         * Did we get a good answer from all the masters?
                         */
                        for (j = 0; j < zone->masterscnt; j++)
                                if (zone->mastersok[j] == ISC_FALSE) {
                                        done = ISC_FALSE;
                                        break;
                                }
                } else
                        done = ISC_TRUE;
                if (!done) {
                        zone->curmaster = 0;
                        /*
                         * Find the next failed master.
                         */
                        while (zone->curmaster < zone->masterscnt &&
                               zone->mastersok[zone->curmaster])
                                zone->curmaster++;
                        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_USEALTXFRSRC);
                } else {
                        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_REFRESH);

                        zone_settimer(zone, &now);
                        goto free_stub;
                }
        }
        queue_soa_query(zone);
        goto free_stub;

 same_master:
        if (msg != NULL)
                dns_message_destroy(&msg);
        isc_event_free(&event);
        dns_request_destroy(&zone->request);
        ns_query(zone, NULL, stub);
        UNLOCK_ZONE(zone);
        goto done;

 free_stub:
        UNLOCK_ZONE(zone);
        stub->magic = 0;
        dns_zone_idetach(&stub->zone);
        INSIST(stub->db == NULL);
        INSIST(stub->version == NULL);
        isc_mem_put(stub->mctx, stub, sizeof(*stub));

 done:
        INSIST(event == NULL);
        return;
}

/*
 * An SOA query has finished (successfully or not).
 */
static void
refresh_callback(isc_task_t *task, isc_event_t *event) {
        const char me[] = "refresh_callback";
        dns_requestevent_t *revent = (dns_requestevent_t *)event;
        dns_zone_t *zone;
        dns_message_t *msg = NULL;
        isc_uint32_t soacnt, cnamecnt, soacount, nscount;
        isc_time_t now;
        char master[ISC_SOCKADDR_FORMATSIZE];
        char source[ISC_SOCKADDR_FORMATSIZE];
        dns_rdataset_t *rdataset = NULL;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_rdata_soa_t soa;
        isc_result_t result;
        isc_uint32_t serial, oldserial = 0;
        unsigned int j;
        isc_boolean_t do_queue_xfrin = ISC_FALSE;

        zone = revent->ev_arg;
        INSIST(DNS_ZONE_VALID(zone));

        UNUSED(task);

        ENTER;

        TIME_NOW(&now);

        LOCK_ZONE(zone);

        /*
         * if timeout log and next master;
         */

        isc_sockaddr_format(&zone->masteraddr, master, sizeof(master));
        isc_sockaddr_format(&zone->sourceaddr, source, sizeof(source));

        if (revent->result != ISC_R_SUCCESS) {
                if (revent->result == ISC_R_TIMEDOUT &&
                    !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOEDNS)) {
                        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOEDNS);
                        dns_zone_log(zone, ISC_LOG_DEBUG(1),
                                     "refresh: timeout retrying without EDNS "
                                     "master %s (source %s)", master, source);
                        goto same_master;
                }
                if (revent->result == ISC_R_TIMEDOUT &&
                    !dns_request_usedtcp(revent->request)) {
                        dns_zone_log(zone, ISC_LOG_INFO,
                                     "refresh: retry limit for "
                                     "master %s exceeded (source %s)",
                                     master, source);
                        /* Try with slave with TCP. */
                        if (zone->type == dns_zone_slave &&
                            DNS_ZONE_OPTION(zone, DNS_ZONEOPT_TRYTCPREFRESH)) {
                                if (!dns_zonemgr_unreachable(zone->zmgr,
                                                             &zone->masteraddr,
                                                             &zone->sourceaddr,
                                                             &now))
                                {
                                        DNS_ZONE_SETFLAG(zone,
                                                     DNS_ZONEFLG_SOABEFOREAXFR);
                                        goto tcp_transfer;
                                }
                                dns_zone_log(zone, ISC_LOG_DEBUG(1),
                                             "refresh: skipped tcp fallback "
                                             "as master %s (source %s) is "
                                             "unreachable (cached)",
                                              master, source);
                        }
                } else
                        dns_zone_log(zone, ISC_LOG_INFO,
                                     "refresh: failure trying master "
                                     "%s (source %s): %s", master, source,
                                     dns_result_totext(revent->result));
                goto next_master;
        }

        result = dns_message_create(zone->mctx, DNS_MESSAGE_INTENTPARSE, &msg);
        if (result != ISC_R_SUCCESS)
                goto next_master;
        result = dns_request_getresponse(revent->request, msg, 0);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_INFO,
                             "refresh: failure trying master "
                             "%s (source %s): %s", master, source,
                             dns_result_totext(result));
                goto next_master;
        }

        /*
         * Unexpected rcode.
         */
        if (msg->rcode != dns_rcode_noerror) {
                char rcode[128];
                isc_buffer_t rb;

                isc_buffer_init(&rb, rcode, sizeof(rcode));
                (void)dns_rcode_totext(msg->rcode, &rb);

                if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOEDNS) &&
                    (msg->rcode == dns_rcode_servfail ||
                     msg->rcode == dns_rcode_notimp ||
                     msg->rcode == dns_rcode_formerr)) {
                        dns_zone_log(zone, ISC_LOG_DEBUG(1),
                                     "refresh: rcode (%.*s) retrying without "
                                     "EDNS master %s (source %s)",
                                     (int)rb.used, rcode, master, source);
                        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOEDNS);
                        goto same_master;
                }
                dns_zone_log(zone, ISC_LOG_INFO,
                             "refresh: unexpected rcode (%.*s) from "
                             "master %s (source %s)", (int)rb.used, rcode,
                             master, source);
                /*
                 * Perhaps AXFR/IXFR is allowed even if SOA queries aren't.
                 */
                if (msg->rcode == dns_rcode_refused &&
                    zone->type == dns_zone_slave)
                        goto tcp_transfer;
                goto next_master;
        }

        /*
         * If truncated punt to zone transfer which will query again.
         */
        if ((msg->flags & DNS_MESSAGEFLAG_TC) != 0) {
                if (zone->type == dns_zone_slave) {
                        dns_zone_log(zone, ISC_LOG_INFO,
                                     "refresh: truncated UDP answer, "
                                     "initiating TCP zone xfer "
                                     "for master %s (source %s)",
                                     master, source);
                        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_SOABEFOREAXFR);
                        goto tcp_transfer;
                } else {
                        INSIST(zone->type == dns_zone_stub);
                        if (dns_request_usedtcp(revent->request)) {
                                dns_zone_log(zone, ISC_LOG_INFO,
                                             "refresh: truncated TCP response "
                                             "from master %s (source %s)",
                                             master, source);
                                goto next_master;
                        }
                        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_USEVC);
                        goto same_master;
                }
        }

        /*
         * if non-auth log and next master;
         */
        if ((msg->flags & DNS_MESSAGEFLAG_AA) == 0) {
                dns_zone_log(zone, ISC_LOG_INFO,
                             "refresh: non-authoritative answer from "
                             "master %s (source %s)", master, source);
                goto next_master;
        }

        cnamecnt = message_count(msg, DNS_SECTION_ANSWER, dns_rdatatype_cname);
        soacnt = message_count(msg, DNS_SECTION_ANSWER, dns_rdatatype_soa);
        nscount = message_count(msg, DNS_SECTION_AUTHORITY, dns_rdatatype_ns);
        soacount = message_count(msg, DNS_SECTION_AUTHORITY,
                                 dns_rdatatype_soa);

        /*
         * There should not be a CNAME record at top of zone.
         */
        if (cnamecnt != 0) {
                dns_zone_log(zone, ISC_LOG_INFO,
                             "refresh: CNAME at top of zone "
                             "in master %s (source %s)", master, source);
                goto next_master;
        }

        /*
         * if referral log and next master;
         */
        if (soacnt == 0 && soacount == 0 && nscount != 0) {
                dns_zone_log(zone, ISC_LOG_INFO,
                             "refresh: referral response "
                             "from master %s (source %s)", master, source);
                goto next_master;
        }

        /*
         * if nodata log and next master;
         */
        if (soacnt == 0 && (nscount == 0 || soacount != 0)) {
                dns_zone_log(zone, ISC_LOG_INFO,
                             "refresh: NODATA response "
                             "from master %s (source %s)", master, source);
                goto next_master;
        }

        /*
         * Only one soa at top of zone.
         */
        if (soacnt != 1) {
                dns_zone_log(zone, ISC_LOG_INFO,
                             "refresh: answer SOA count (%d) != 1 "
                             "from master %s (source %s)",
                             soacnt, master, source);
                goto next_master;
        }

        /*
         * Extract serial
         */
        rdataset = NULL;
        result = dns_message_findname(msg, DNS_SECTION_ANSWER, &zone->origin,
                                      dns_rdatatype_soa, dns_rdatatype_none,
                                      NULL, &rdataset);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_INFO,
                             "refresh: unable to get SOA record "
                             "from master %s (source %s)", master, source);
                goto next_master;
        }

        result = dns_rdataset_first(rdataset);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_INFO,
                             "refresh: dns_rdataset_first() failed");
                goto next_master;
        }

        dns_rdataset_current(rdataset, &rdata);
        result = dns_rdata_tostruct(&rdata, &soa, NULL);
        RUNTIME_CHECK(result == ISC_R_SUCCESS);

        serial = soa.serial;
        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED)) {
                result = zone_get_from_db(zone, zone->db, NULL, NULL,
                                          &oldserial, NULL, NULL, NULL, NULL,
                                          NULL);
                RUNTIME_CHECK(result == ISC_R_SUCCESS);
                zone_debuglog(zone, me, 1, "serial: new %u, old %u",
                              serial, oldserial);
        } else
                zone_debuglog(zone, me, 1, "serial: new %u, old not loaded",
                              serial);

        if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED) ||
            DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FORCEXFER) ||
            isc_serial_gt(serial, oldserial)) {
                if (dns_zonemgr_unreachable(zone->zmgr, &zone->masteraddr,
                                            &zone->sourceaddr, &now))
                {
                        dns_zone_log(zone, ISC_LOG_INFO,
                                     "refresh: skipping %s as master %s "
                                     "(source %s) is unreachable (cached)",
                                     zone->type == dns_zone_slave ?
                                     "zone transfer" : "NS query",
                                     master, source);
                        goto next_master;
                }
 tcp_transfer:
                isc_event_free(&event);
                dns_request_destroy(&zone->request);
                if (zone->type == dns_zone_slave) {
                        do_queue_xfrin = ISC_TRUE;
                } else {
                        INSIST(zone->type == dns_zone_stub);
                        ns_query(zone, rdataset, NULL);
                }
                if (msg != NULL)
                        dns_message_destroy(&msg);
        } else if (isc_serial_eq(soa.serial, oldserial)) {
                if (zone->masterfile != NULL) {
                        result = ISC_R_FAILURE;
                        if (zone->journal != NULL)
                                result = isc_file_settime(zone->journal, &now);
                        if (result == ISC_R_SUCCESS &&
                            !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDDUMP) &&
                            !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DUMPING)) {
                                result = isc_file_settime(zone->masterfile,
                                                          &now);
                        } else if (result != ISC_R_SUCCESS)
                                result = isc_file_settime(zone->masterfile,
                                                          &now);
                        /* Someone removed the file from underneath us! */
                        if (result == ISC_R_FILENOTFOUND) {
                                zone_needdump(zone, DNS_DUMP_DELAY);
                        } else if (result != ISC_R_SUCCESS)
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "refresh: could not set file "
                                             "modification time of '%s': %s",
                                             zone->masterfile,
                                             dns_result_totext(result));
                }
                DNS_ZONE_JITTER_ADD(&now, zone->refresh, &zone->refreshtime);
                DNS_ZONE_TIME_ADD(&now, zone->expire, &zone->expiretime);
                zone->mastersok[zone->curmaster] = ISC_TRUE;
                goto next_master;
        } else {
                if (!DNS_ZONE_OPTION(zone, DNS_ZONEOPT_MULTIMASTER))
                        dns_zone_log(zone, ISC_LOG_INFO, "serial number (%u) "
                                     "received from master %s < ours (%u)",
                                     soa.serial, master, oldserial);
                else
                        zone_debuglog(zone, me, 1, "ahead");
                zone->mastersok[zone->curmaster] = ISC_TRUE;
                goto next_master;
        }
        if (msg != NULL)
                dns_message_destroy(&msg);
        goto detach;

 next_master:
        if (msg != NULL)
                dns_message_destroy(&msg);
        isc_event_free(&event);
        dns_request_destroy(&zone->request);
        /*
         * Skip to next failed / untried master.
         */
        do {
                zone->curmaster++;
        } while (zone->curmaster < zone->masterscnt &&
                 zone->mastersok[zone->curmaster]);
        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NOEDNS);
        if (zone->curmaster >= zone->masterscnt) {
                isc_boolean_t done = ISC_TRUE;
                if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_USEALTXFRSRC) &&
                    !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_USEALTXFRSRC)) {
                        /*
                         * Did we get a good answer from all the masters?
                         */
                        for (j = 0; j < zone->masterscnt; j++)
                                if (zone->mastersok[j] == ISC_FALSE) {
                                        done = ISC_FALSE;
                                        break;
                                }
                } else
                        done = ISC_TRUE;
                if (!done) {
                        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_USEALTXFRSRC);
                        zone->curmaster = 0;
                        /*
                         * Find the next failed master.
                         */
                        while (zone->curmaster < zone->masterscnt &&
                               zone->mastersok[zone->curmaster])
                                zone->curmaster++;
                        goto requeue;
                }
                DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_REFRESH);
                if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDREFRESH)) {
                        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NEEDREFRESH);
                        zone->refreshtime = now;
                }
                DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_USEALTXFRSRC);
                zone_settimer(zone, &now);
                goto detach;
        }

 requeue:
        queue_soa_query(zone);
        goto detach;

 same_master:
        if (msg != NULL)
                dns_message_destroy(&msg);
        isc_event_free(&event);
        dns_request_destroy(&zone->request);
        queue_soa_query(zone);

 detach:
        UNLOCK_ZONE(zone);
        if (do_queue_xfrin)
                queue_xfrin(zone);
        dns_zone_idetach(&zone);
        return;
}

static void
queue_soa_query(dns_zone_t *zone) {
        const char me[] = "queue_soa_query";
        isc_event_t *e;
        dns_zone_t *dummy = NULL;
        isc_result_t result;

        ENTER;
        /*
         * Locked by caller
         */
        REQUIRE(LOCKED_ZONE(zone));

        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING)) {
                cancel_refresh(zone);
                return;
        }

        e = isc_event_allocate(zone->mctx, NULL, DNS_EVENT_ZONE,
                               soa_query, zone, sizeof(isc_event_t));
        if (e == NULL) {
                cancel_refresh(zone);
                return;
        }

        /*
         * Attach so that we won't clean up
         * until the event is delivered.
         */
        zone_iattach(zone, &dummy);

        e->ev_arg = zone;
        e->ev_sender = NULL;
        result = isc_ratelimiter_enqueue(zone->zmgr->rl, zone->task, &e);
        if (result != ISC_R_SUCCESS) {
                zone_idetach(&dummy);
                isc_event_free(&e);
                cancel_refresh(zone);
        }
}

static inline isc_result_t
create_query(dns_zone_t *zone, dns_rdatatype_t rdtype,
             dns_message_t **messagep)
{
        dns_message_t *message = NULL;
        dns_name_t *qname = NULL;
        dns_rdataset_t *qrdataset = NULL;
        isc_result_t result;

        result = dns_message_create(zone->mctx, DNS_MESSAGE_INTENTRENDER,
                                    &message);
        if (result != ISC_R_SUCCESS)
                goto cleanup;

        message->opcode = dns_opcode_query;
        message->rdclass = zone->rdclass;

        result = dns_message_gettempname(message, &qname);
        if (result != ISC_R_SUCCESS)
                goto cleanup;

        result = dns_message_gettemprdataset(message, &qrdataset);
        if (result != ISC_R_SUCCESS)
                goto cleanup;

        /*
         * Make question.
         */
        dns_name_init(qname, NULL);
        dns_name_clone(&zone->origin, qname);
        dns_rdataset_init(qrdataset);
        dns_rdataset_makequestion(qrdataset, zone->rdclass, rdtype);
        ISC_LIST_APPEND(qname->list, qrdataset, link);
        dns_message_addname(message, qname, DNS_SECTION_QUESTION);

        *messagep = message;
        return (ISC_R_SUCCESS);

 cleanup:
        if (qname != NULL)
                dns_message_puttempname(message, &qname);
        if (qrdataset != NULL)
                dns_message_puttemprdataset(message, &qrdataset);
        if (message != NULL)
                dns_message_destroy(&message);
        return (result);
}

static isc_result_t
add_opt(dns_message_t *message, isc_uint16_t udpsize, isc_boolean_t reqnsid) {
        dns_rdataset_t *rdataset = NULL;
        dns_rdatalist_t *rdatalist = NULL;
        dns_rdata_t *rdata = NULL;
        isc_result_t result;

        result = dns_message_gettemprdatalist(message, &rdatalist);
        if (result != ISC_R_SUCCESS)
                goto cleanup;
        result = dns_message_gettemprdata(message, &rdata);
        if (result != ISC_R_SUCCESS)
                goto cleanup;
        result = dns_message_gettemprdataset(message, &rdataset);
        if (result != ISC_R_SUCCESS)
                goto cleanup;
        dns_rdataset_init(rdataset);

        rdatalist->type = dns_rdatatype_opt;
        rdatalist->covers = 0;

        /*
         * Set Maximum UDP buffer size.
         */
        rdatalist->rdclass = udpsize;

        /*
         * Set EXTENDED-RCODE, VERSION, DO and Z to 0.
         */
        rdatalist->ttl = 0;

        /* Set EDNS options if applicable */
        if (reqnsid) {
                unsigned char data[4];
                isc_buffer_t buf;

                isc_buffer_init(&buf, data, sizeof(data));
                isc_buffer_putuint16(&buf, DNS_OPT_NSID);
                isc_buffer_putuint16(&buf, 0);
                rdata->data = data;
                rdata->length = sizeof(data);
        } else {
                rdata->data = NULL;
                rdata->length = 0;
        }

        rdata->rdclass = rdatalist->rdclass;
        rdata->type = rdatalist->type;
        rdata->flags = 0;

        ISC_LIST_INIT(rdatalist->rdata);
        ISC_LIST_APPEND(rdatalist->rdata, rdata, link);
        RUNTIME_CHECK(dns_rdatalist_tordataset(rdatalist, rdataset)
                      == ISC_R_SUCCESS);

        return (dns_message_setopt(message, rdataset));

 cleanup:
        if (rdatalist != NULL)
                dns_message_puttemprdatalist(message, &rdatalist);
        if (rdataset != NULL)
                dns_message_puttemprdataset(message, &rdataset);
        if (rdata != NULL)
                dns_message_puttemprdata(message, &rdata);

        return (result);
}

static void
soa_query(isc_task_t *task, isc_event_t *event) {
        const char me[] = "soa_query";
        isc_result_t result = ISC_R_FAILURE;
        dns_message_t *message = NULL;
        dns_zone_t *zone = event->ev_arg;
        dns_zone_t *dummy = NULL;
        isc_netaddr_t masterip;
        dns_tsigkey_t *key = NULL;
        isc_uint32_t options;
        isc_boolean_t cancel = ISC_TRUE;
        int timeout;
        isc_boolean_t have_xfrsource, reqnsid;
        isc_uint16_t udpsize = SEND_BUFFER_SIZE;

        REQUIRE(DNS_ZONE_VALID(zone));

        UNUSED(task);

        ENTER;

        LOCK_ZONE(zone);
        if (((event->ev_attributes & ISC_EVENTATTR_CANCELED) != 0) ||
            DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING) ||
            zone->view->requestmgr == NULL) {
                if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING))
                        cancel = ISC_FALSE;
                goto cleanup;
        }

        /*
         * XXX Optimisation: Create message when zone is setup and reuse.
         */
        result = create_query(zone, dns_rdatatype_soa, &message);
        if (result != ISC_R_SUCCESS)
                goto cleanup;

 again:
        INSIST(zone->masterscnt > 0);
        INSIST(zone->curmaster < zone->masterscnt);

        zone->masteraddr = zone->masters[zone->curmaster];

        isc_netaddr_fromsockaddr(&masterip, &zone->masteraddr);
        /*
         * First, look for a tsig key in the master statement, then
         * try for a server key.
         */
        if ((zone->masterkeynames != NULL) &&
            (zone->masterkeynames[zone->curmaster] != NULL)) {
                dns_view_t *view = dns_zone_getview(zone);
                dns_name_t *keyname = zone->masterkeynames[zone->curmaster];
                result = dns_view_gettsig(view, keyname, &key);
                if (result != ISC_R_SUCCESS) {
                        char namebuf[DNS_NAME_FORMATSIZE];
                        dns_name_format(keyname, namebuf, sizeof(namebuf));
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "unable to find key: %s", namebuf);
                        goto skip_master;
                }
        }
        if (key == NULL) {
                result = dns_view_getpeertsig(zone->view, &masterip, &key);
                if (result != ISC_R_SUCCESS && result != ISC_R_NOTFOUND) {
                        char addrbuf[ISC_NETADDR_FORMATSIZE];
                        isc_netaddr_format(&masterip, addrbuf, sizeof(addrbuf));
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "unable to find TSIG key for %s", addrbuf);
                        goto skip_master;
                }
        }

        have_xfrsource = ISC_FALSE;
        reqnsid = zone->view->requestnsid;
        if (zone->view->peers != NULL) {
                dns_peer_t *peer = NULL;
                isc_boolean_t edns;
                result = dns_peerlist_peerbyaddr(zone->view->peers,
                                                 &masterip, &peer);
                if (result == ISC_R_SUCCESS) {
                        result = dns_peer_getsupportedns(peer, &edns);
                        if (result == ISC_R_SUCCESS && !edns)
                                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOEDNS);
                        result = dns_peer_gettransfersource(peer,
                                                            &zone->sourceaddr);
                        if (result == ISC_R_SUCCESS)
                                have_xfrsource = ISC_TRUE;
                        if (zone->view->resolver != NULL)
                                udpsize =
                                  dns_resolver_getudpsize(zone->view->resolver);
                        (void)dns_peer_getudpsize(peer, &udpsize);
                        (void)dns_peer_getrequestnsid(peer, &reqnsid);
                }
        }

        switch (isc_sockaddr_pf(&zone->masteraddr)) {
        case PF_INET:
                if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_USEALTXFRSRC)) {
                        if (isc_sockaddr_equal(&zone->altxfrsource4,
                                               &zone->xfrsource4))
                                goto skip_master;
                        zone->sourceaddr = zone->altxfrsource4;
                } else if (!have_xfrsource)
                        zone->sourceaddr = zone->xfrsource4;
                break;
        case PF_INET6:
                if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_USEALTXFRSRC)) {
                        if (isc_sockaddr_equal(&zone->altxfrsource6,
                                               &zone->xfrsource6))
                                goto skip_master;
                        zone->sourceaddr = zone->altxfrsource6;
                } else if (!have_xfrsource)
                        zone->sourceaddr = zone->xfrsource6;
                break;
        default:
                result = ISC_R_NOTIMPLEMENTED;
                goto cleanup;
        }

        options = DNS_ZONE_FLAG(zone, DNS_ZONEFLG_USEVC) ?
                  DNS_REQUESTOPT_TCP : 0;

        if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOEDNS)) {
                result = add_opt(message, udpsize, reqnsid);
                if (result != ISC_R_SUCCESS)
                        zone_debuglog(zone, me, 1,
                                      "unable to add opt record: %s",
                                      dns_result_totext(result));
        }

        zone_iattach(zone, &dummy);
        timeout = 15;
        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DIALREFRESH))
                timeout = 30;
        result = dns_request_createvia2(zone->view->requestmgr, message,
                                        &zone->sourceaddr, &zone->masteraddr,
                                        options, key, timeout * 3, timeout,
                                        zone->task, refresh_callback, zone,
                                        &zone->request);
        if (result != ISC_R_SUCCESS) {
                zone_idetach(&dummy);
                zone_debuglog(zone, me, 1,
                              "dns_request_createvia2() failed: %s",
                              dns_result_totext(result));
                goto cleanup;
        } else {
                if (isc_sockaddr_pf(&zone->masteraddr) == PF_INET)
                        inc_stats(zone, dns_zonestatscounter_soaoutv4);
                else
                        inc_stats(zone, dns_zonestatscounter_soaoutv6);
        }
        cancel = ISC_FALSE;

 cleanup:
        if (key != NULL)
                dns_tsigkey_detach(&key);
        if (result != ISC_R_SUCCESS)
                DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_REFRESH);
        if (message != NULL)
                dns_message_destroy(&message);
        if (cancel)
                cancel_refresh(zone);
        isc_event_free(&event);
        UNLOCK_ZONE(zone);
        dns_zone_idetach(&zone);
        return;

 skip_master:
        if (key != NULL)
                dns_tsigkey_detach(&key);
        /*
         * Skip to next failed / untried master.
         */
        do {
                zone->curmaster++;
        } while (zone->curmaster < zone->masterscnt &&
                 zone->mastersok[zone->curmaster]);
        if (zone->curmaster < zone->masterscnt)
                goto again;
        zone->curmaster = 0;
        goto cleanup;
}

static void
ns_query(dns_zone_t *zone, dns_rdataset_t *soardataset, dns_stub_t *stub) {
        const char me[] = "ns_query";
        isc_result_t result;
        dns_message_t *message = NULL;
        isc_netaddr_t masterip;
        dns_tsigkey_t *key = NULL;
        dns_dbnode_t *node = NULL;
        int timeout;
        isc_boolean_t have_xfrsource = ISC_FALSE, reqnsid;
        isc_uint16_t udpsize = SEND_BUFFER_SIZE;

        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(LOCKED_ZONE(zone));
        REQUIRE((soardataset != NULL && stub == NULL) ||
                (soardataset == NULL && stub != NULL));
        REQUIRE(stub == NULL || DNS_STUB_VALID(stub));

        ENTER;

        if (stub == NULL) {
                stub = isc_mem_get(zone->mctx, sizeof(*stub));
                if (stub == NULL)
                        goto cleanup;
                stub->magic = STUB_MAGIC;
                stub->mctx = zone->mctx;
                stub->zone = NULL;
                stub->db = NULL;
                stub->version = NULL;

                /*
                 * Attach so that the zone won't disappear from under us.
                 */
                zone_iattach(zone, &stub->zone);

                /*
                 * If a db exists we will update it, otherwise we create a
                 * new one and attach it to the zone once we have the NS
                 * RRset and glue.
                 */
                ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
                if (zone->db != NULL) {
                        dns_db_attach(zone->db, &stub->db);
                        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
                } else {
                        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);

                        INSIST(zone->db_argc >= 1);
                        result = dns_db_create(zone->mctx, zone->db_argv[0],
                                               &zone->origin, dns_dbtype_stub,
                                               zone->rdclass,
                                               zone->db_argc - 1,
                                               zone->db_argv + 1,
                                               &stub->db);
                        if (result != ISC_R_SUCCESS) {
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "refreshing stub: "
                                             "could not create "
                                             "database: %s",
                                             dns_result_totext(result));
                                goto cleanup;
                        }
                        dns_db_settask(stub->db, zone->task);
                }

                result = dns_db_newversion(stub->db, &stub->version);
                if (result != ISC_R_SUCCESS) {
                        dns_zone_log(zone, ISC_LOG_INFO, "refreshing stub: "
                                     "dns_db_newversion() failed: %s",
                                     dns_result_totext(result));
                        goto cleanup;
                }

                /*
                 * Update SOA record.
                 */
                result = dns_db_findnode(stub->db, &zone->origin, ISC_TRUE,
                                         &node);
                if (result != ISC_R_SUCCESS) {
                        dns_zone_log(zone, ISC_LOG_INFO, "refreshing stub: "
                                     "dns_db_findnode() failed: %s",
                                     dns_result_totext(result));
                        goto cleanup;
                }

                result = dns_db_addrdataset(stub->db, node, stub->version, 0,
                                            soardataset, 0, NULL);
                dns_db_detachnode(stub->db, &node);
                if (result != ISC_R_SUCCESS) {
                        dns_zone_log(zone, ISC_LOG_INFO,
                                     "refreshing stub: "
                                     "dns_db_addrdataset() failed: %s",
                                     dns_result_totext(result));
                        goto cleanup;
                }
        }

        /*
         * XXX Optimisation: Create message when zone is setup and reuse.
         */
        result = create_query(zone, dns_rdatatype_ns, &message);
        INSIST(result == ISC_R_SUCCESS);

        INSIST(zone->masterscnt > 0);
        INSIST(zone->curmaster < zone->masterscnt);
        zone->masteraddr = zone->masters[zone->curmaster];

        isc_netaddr_fromsockaddr(&masterip, &zone->masteraddr);
        /*
         * First, look for a tsig key in the master statement, then
         * try for a server key.
         */
        if ((zone->masterkeynames != NULL) &&
            (zone->masterkeynames[zone->curmaster] != NULL)) {
                dns_view_t *view = dns_zone_getview(zone);
                dns_name_t *keyname = zone->masterkeynames[zone->curmaster];
                result = dns_view_gettsig(view, keyname, &key);
                if (result != ISC_R_SUCCESS) {
                        char namebuf[DNS_NAME_FORMATSIZE];
                        dns_name_format(keyname, namebuf, sizeof(namebuf));
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "unable to find key: %s", namebuf);
                }
        }
        if (key == NULL)
                (void)dns_view_getpeertsig(zone->view, &masterip, &key);

        reqnsid = zone->view->requestnsid;
        if (zone->view->peers != NULL) {
                dns_peer_t *peer = NULL;
                isc_boolean_t edns;
                result = dns_peerlist_peerbyaddr(zone->view->peers,
                                                 &masterip, &peer);
                if (result == ISC_R_SUCCESS) {
                        result = dns_peer_getsupportedns(peer, &edns);
                        if (result == ISC_R_SUCCESS && !edns)
                                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOEDNS);
                        result = dns_peer_gettransfersource(peer,
                                                            &zone->sourceaddr);
                        if (result == ISC_R_SUCCESS)
                                have_xfrsource = ISC_TRUE;
                        if (zone->view->resolver != NULL)
                                udpsize =
                                  dns_resolver_getudpsize(zone->view->resolver);
                        (void)dns_peer_getudpsize(peer, &udpsize);
                        (void)dns_peer_getrequestnsid(peer, &reqnsid);
                }

        }
        if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOEDNS)) {
                result = add_opt(message, udpsize, reqnsid);
                if (result != ISC_R_SUCCESS)
                        zone_debuglog(zone, me, 1,
                                      "unable to add opt record: %s",
                                      dns_result_totext(result));
        }

        /*
         * Always use TCP so that we shouldn't truncate in additional section.
         */
        switch (isc_sockaddr_pf(&zone->masteraddr)) {
        case PF_INET:
                if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_USEALTXFRSRC))
                        zone->sourceaddr = zone->altxfrsource4;
                else if (!have_xfrsource)
                        zone->sourceaddr = zone->xfrsource4;
                break;
        case PF_INET6:
                if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_USEALTXFRSRC))
                        zone->sourceaddr = zone->altxfrsource6;
                else if (!have_xfrsource)
                        zone->sourceaddr = zone->xfrsource6;
                break;
        default:
                result = ISC_R_NOTIMPLEMENTED;
                POST(result);
                goto cleanup;
        }
        timeout = 15;
        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DIALREFRESH))
                timeout = 30;
        result = dns_request_createvia2(zone->view->requestmgr, message,
                                        &zone->sourceaddr, &zone->masteraddr,
                                        DNS_REQUESTOPT_TCP, key, timeout * 3,
                                        timeout, zone->task, stub_callback,
                                        stub, &zone->request);
        if (result != ISC_R_SUCCESS) {
                zone_debuglog(zone, me, 1,
                              "dns_request_createvia() failed: %s",
                              dns_result_totext(result));
                goto cleanup;
        }
        dns_message_destroy(&message);
        goto unlock;

 cleanup:
        cancel_refresh(zone);
        if (stub != NULL) {
                stub->magic = 0;
                if (stub->version != NULL)
                        dns_db_closeversion(stub->db, &stub->version,
                                            ISC_FALSE);
                if (stub->db != NULL)
                        dns_db_detach(&stub->db);
                if (stub->zone != NULL)
                        zone_idetach(&stub->zone);
                isc_mem_put(stub->mctx, stub, sizeof(*stub));
        }
        if (message != NULL)
                dns_message_destroy(&message);
 unlock:
        if (key != NULL)
                dns_tsigkey_detach(&key);
        return;
}

/*
 * Handle the control event.  Note that although this event causes the zone
 * to shut down, it is not a shutdown event in the sense of the task library.
 */
static void
zone_shutdown(isc_task_t *task, isc_event_t *event) {
        dns_zone_t *zone = (dns_zone_t *) event->ev_arg;
        isc_boolean_t free_needed, linked = ISC_FALSE;

        UNUSED(task);
        REQUIRE(DNS_ZONE_VALID(zone));
        INSIST(event->ev_type == DNS_EVENT_ZONECONTROL);
        INSIST(isc_refcount_current(&zone->erefs) == 0);

        zone_debuglog(zone, "zone_shutdown", 3, "shutting down");

        /*
         * Stop things being restarted after we cancel them below.
         */
        LOCK_ZONE(zone);
        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_EXITING);
        UNLOCK_ZONE(zone);

        /*
         * If we were waiting for xfrin quota, step out of
         * the queue.
         * If there's no zone manager, we can't be waiting for the
         * xfrin quota
         */
        if (zone->zmgr != NULL) {
                RWLOCK(&zone->zmgr->rwlock, isc_rwlocktype_write);
                if (zone->statelist == &zone->zmgr->waiting_for_xfrin) {
                        ISC_LIST_UNLINK(zone->zmgr->waiting_for_xfrin, zone,
                                        statelink);
                        linked = ISC_TRUE;
                        zone->statelist = NULL;
                }
                RWUNLOCK(&zone->zmgr->rwlock, isc_rwlocktype_write);
        }

        /*
         * In task context, no locking required.  See zone_xfrdone().
         */
        if (zone->xfr != NULL)
                dns_xfrin_shutdown(zone->xfr);

        LOCK_ZONE(zone);
        if (linked) {
                INSIST(zone->irefs > 0);
                zone->irefs--;
        }
        if (zone->request != NULL) {
                dns_request_cancel(zone->request);
        }

        if (zone->readio != NULL)
                zonemgr_cancelio(zone->readio);

        if (zone->lctx != NULL)
                dns_loadctx_cancel(zone->lctx);

        if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FLUSH) ||
            !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DUMPING)) {
                if (zone->writeio != NULL)
                        zonemgr_cancelio(zone->writeio);

                if (zone->dctx != NULL)
                        dns_dumpctx_cancel(zone->dctx);
        }

        notify_cancel(zone);

        forward_cancel(zone);

        if (zone->timer != NULL) {
                isc_timer_detach(&zone->timer);
                INSIST(zone->irefs > 0);
                zone->irefs--;
        }

        if (zone->view != NULL)
                dns_view_weakdetach(&zone->view);

        /*
         * We have now canceled everything set the flag to allow exit_check()
         * to succeed.  We must not unlock between setting this flag and
         * calling exit_check().
         */
        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_SHUTDOWN);
        free_needed = exit_check(zone);
        UNLOCK_ZONE(zone);
        if (free_needed)
                zone_free(zone);
}

static void
zone_timer(isc_task_t *task, isc_event_t *event) {
        const char me[] = "zone_timer";
        dns_zone_t *zone = (dns_zone_t *)event->ev_arg;

        UNUSED(task);
        REQUIRE(DNS_ZONE_VALID(zone));

        ENTER;

        zone_maintenance(zone);

        isc_event_free(&event);
}

static void
zone_settimer(dns_zone_t *zone, isc_time_t *now) {
        const char me[] = "zone_settimer";
        isc_time_t next;
        isc_result_t result;

        ENTER;
        REQUIRE(DNS_ZONE_VALID(zone));
        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING))
                return;

        isc_time_settoepoch(&next);

        switch (zone->type) {
        case dns_zone_master:
                if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDNOTIFY))
                        next = zone->notifytime;
                if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDDUMP) &&
                    !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DUMPING)) {
                        INSIST(!isc_time_isepoch(&zone->dumptime));
                        if (isc_time_isepoch(&next) ||
                            isc_time_compare(&zone->dumptime, &next) < 0)
                                next = zone->dumptime;
                }
                if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_REFRESHING) &&
                    !isc_time_isepoch(&zone->refreshkeytime)) {
                        if (isc_time_isepoch(&next) ||
                            isc_time_compare(&zone->refreshkeytime, &next) < 0)
                                next = zone->refreshkeytime;
                }
                if (!isc_time_isepoch(&zone->resigntime)) {
                        if (isc_time_isepoch(&next) ||
                            isc_time_compare(&zone->resigntime, &next) < 0)
                                next = zone->resigntime;
                }
                if (!isc_time_isepoch(&zone->keywarntime)) {
                        if (isc_time_isepoch(&next) ||
                            isc_time_compare(&zone->keywarntime, &next) < 0)
                                next = zone->keywarntime;
                }
                if (!isc_time_isepoch(&zone->signingtime)) {
                        if (isc_time_isepoch(&next) ||
                            isc_time_compare(&zone->signingtime, &next) < 0)
                                next = zone->signingtime;
                }
                if (!isc_time_isepoch(&zone->nsec3chaintime)) {
                        if (isc_time_isepoch(&next) ||
                            isc_time_compare(&zone->nsec3chaintime, &next) < 0)
                                next = zone->nsec3chaintime;
                }
                break;

        case dns_zone_slave:
                if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDNOTIFY))
                        next = zone->notifytime;
                /*FALLTHROUGH*/

        case dns_zone_stub:
                if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_REFRESH) &&
                    !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOMASTERS) &&
                    !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOREFRESH) &&
                    !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADING)) {
                        INSIST(!isc_time_isepoch(&zone->refreshtime));
                        if (isc_time_isepoch(&next) ||
                            isc_time_compare(&zone->refreshtime, &next) < 0)
                                next = zone->refreshtime;
                }
                if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED)) {
                        INSIST(!isc_time_isepoch(&zone->expiretime));
                        if (isc_time_isepoch(&next) ||
                            isc_time_compare(&zone->expiretime, &next) < 0)
                                next = zone->expiretime;
                }
                if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDDUMP) &&
                    !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DUMPING)) {
                        INSIST(!isc_time_isepoch(&zone->dumptime));
                        if (isc_time_isepoch(&next) ||
                            isc_time_compare(&zone->dumptime, &next) < 0)
                                next = zone->dumptime;
                }
                break;

        case dns_zone_key:
                if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDDUMP) &&
                    !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DUMPING)) {
                        INSIST(!isc_time_isepoch(&zone->dumptime));
                        if (isc_time_isepoch(&next) ||
                            isc_time_compare(&zone->dumptime, &next) < 0)
                                next = zone->dumptime;
                }
                if (!DNS_ZONE_FLAG(zone, DNS_ZONEFLG_REFRESHING)) {
                        if (isc_time_isepoch(&next) ||
                            (!isc_time_isepoch(&zone->refreshkeytime) &&
                            isc_time_compare(&zone->refreshkeytime, &next) < 0))
                                next = zone->refreshkeytime;
                }
                break;

        default:
                break;
        }

        if (isc_time_isepoch(&next)) {
                zone_debuglog(zone, me, 10, "settimer inactive");
                result = isc_timer_reset(zone->timer, isc_timertype_inactive,
                                          NULL, NULL, ISC_TRUE);
                if (result != ISC_R_SUCCESS)
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "could not deactivate zone timer: %s",
                                     isc_result_totext(result));
        } else {
                if (isc_time_compare(&next, now) <= 0)
                        next = *now;
                result = isc_timer_reset(zone->timer, isc_timertype_once,
                                         &next, NULL, ISC_TRUE);
                if (result != ISC_R_SUCCESS)
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "could not reset zone timer: %s",
                                     isc_result_totext(result));
        }
}

static void
cancel_refresh(dns_zone_t *zone) {
        const char me[] = "cancel_refresh";
        isc_time_t now;

        /*
         * 'zone' locked by caller.
         */

        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(LOCKED_ZONE(zone));

        ENTER;

        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_REFRESH);
        TIME_NOW(&now);
        zone_settimer(zone, &now);
}

static isc_result_t
notify_createmessage(dns_zone_t *zone, unsigned int flags,
                     dns_message_t **messagep)
{
        dns_db_t *zonedb = NULL;
        dns_dbnode_t *node = NULL;
        dns_dbversion_t *version = NULL;
        dns_message_t *message = NULL;
        dns_rdataset_t rdataset;
        dns_rdata_t rdata = DNS_RDATA_INIT;

        dns_name_t *tempname = NULL;
        dns_rdata_t *temprdata = NULL;
        dns_rdatalist_t *temprdatalist = NULL;
        dns_rdataset_t *temprdataset = NULL;

        isc_result_t result;
        isc_region_t r;
        isc_buffer_t *b = NULL;

        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(messagep != NULL && *messagep == NULL);

        result = dns_message_create(zone->mctx, DNS_MESSAGE_INTENTRENDER,
                                    &message);
        if (result != ISC_R_SUCCESS)
                return (result);

        message->opcode = dns_opcode_notify;
        message->flags |= DNS_MESSAGEFLAG_AA;
        message->rdclass = zone->rdclass;

        result = dns_message_gettempname(message, &tempname);
        if (result != ISC_R_SUCCESS)
                goto cleanup;

        result = dns_message_gettemprdataset(message, &temprdataset);
        if (result != ISC_R_SUCCESS)
                goto cleanup;

        /*
         * Make question.
         */
        dns_name_init(tempname, NULL);
        dns_name_clone(&zone->origin, tempname);
        dns_rdataset_init(temprdataset);
        dns_rdataset_makequestion(temprdataset, zone->rdclass,
                                  dns_rdatatype_soa);
        ISC_LIST_APPEND(tempname->list, temprdataset, link);
        dns_message_addname(message, tempname, DNS_SECTION_QUESTION);
        tempname = NULL;
        temprdataset = NULL;

        if ((flags & DNS_NOTIFY_NOSOA) != 0)
                goto done;

        result = dns_message_gettempname(message, &tempname);
        if (result != ISC_R_SUCCESS)
                goto soa_cleanup;
        result = dns_message_gettemprdata(message, &temprdata);
        if (result != ISC_R_SUCCESS)
                goto soa_cleanup;
        result = dns_message_gettemprdataset(message, &temprdataset);
        if (result != ISC_R_SUCCESS)
                goto soa_cleanup;
        result = dns_message_gettemprdatalist(message, &temprdatalist);
        if (result != ISC_R_SUCCESS)
                goto soa_cleanup;

        ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
        INSIST(zone->db != NULL); /* XXXJT: is this assumption correct? */
        dns_db_attach(zone->db, &zonedb);
        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);

        dns_name_init(tempname, NULL);
        dns_name_clone(&zone->origin, tempname);
        dns_db_currentversion(zonedb, &version);
        result = dns_db_findnode(zonedb, tempname, ISC_FALSE, &node);
        if (result != ISC_R_SUCCESS)
                goto soa_cleanup;

        dns_rdataset_init(&rdataset);
        result = dns_db_findrdataset(zonedb, node, version,
                                     dns_rdatatype_soa,
                                     dns_rdatatype_none, 0, &rdataset,
                                     NULL);
        if (result != ISC_R_SUCCESS)
                goto soa_cleanup;
        result = dns_rdataset_first(&rdataset);
        if (result != ISC_R_SUCCESS)
                goto soa_cleanup;
        dns_rdataset_current(&rdataset, &rdata);
        dns_rdata_toregion(&rdata, &r);
        result = isc_buffer_allocate(zone->mctx, &b, r.length);
        if (result != ISC_R_SUCCESS)
                goto soa_cleanup;
        isc_buffer_putmem(b, r.base, r.length);
        isc_buffer_usedregion(b, &r);
        dns_rdata_init(temprdata);
        dns_rdata_fromregion(temprdata, rdata.rdclass, rdata.type, &r);
        dns_message_takebuffer(message, &b);
        result = dns_rdataset_next(&rdataset);
        dns_rdataset_disassociate(&rdataset);
        if (result != ISC_R_NOMORE)
                goto soa_cleanup;
        temprdatalist->rdclass = rdata.rdclass;
        temprdatalist->type = rdata.type;
        temprdatalist->covers = 0;
        temprdatalist->ttl = rdataset.ttl;
        ISC_LIST_INIT(temprdatalist->rdata);
        ISC_LIST_APPEND(temprdatalist->rdata, temprdata, link);

        dns_rdataset_init(temprdataset);
        result = dns_rdatalist_tordataset(temprdatalist, temprdataset);
        if (result != ISC_R_SUCCESS)
                goto soa_cleanup;

        ISC_LIST_APPEND(tempname->list, temprdataset, link);
        dns_message_addname(message, tempname, DNS_SECTION_ANSWER);
        temprdatalist = NULL;
        temprdataset = NULL;
        temprdata = NULL;
        tempname = NULL;

 soa_cleanup:
        if (node != NULL)
                dns_db_detachnode(zonedb, &node);
        if (version != NULL)
                dns_db_closeversion(zonedb, &version, ISC_FALSE);
        if (zonedb != NULL)
                dns_db_detach(&zonedb);
        if (tempname != NULL)
                dns_message_puttempname(message, &tempname);
        if (temprdata != NULL)
                dns_message_puttemprdata(message, &temprdata);
        if (temprdataset != NULL)
                dns_message_puttemprdataset(message, &temprdataset);
        if (temprdatalist != NULL)
                dns_message_puttemprdatalist(message, &temprdatalist);

 done:
        *messagep = message;
        return (ISC_R_SUCCESS);

 cleanup:
        if (tempname != NULL)
                dns_message_puttempname(message, &tempname);
        if (temprdataset != NULL)
                dns_message_puttemprdataset(message, &temprdataset);
        dns_message_destroy(&message);
        return (result);
}

isc_result_t
dns_zone_notifyreceive(dns_zone_t *zone, isc_sockaddr_t *from,
                       dns_message_t *msg)
{
        unsigned int i;
        dns_rdata_soa_t soa;
        dns_rdataset_t *rdataset = NULL;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        isc_result_t result;
        char fromtext[ISC_SOCKADDR_FORMATSIZE];
        int match = 0;
        isc_netaddr_t netaddr;
        isc_sockaddr_t local, remote;

        REQUIRE(DNS_ZONE_VALID(zone));

        /*
         * If type != T_SOA return DNS_R_NOTIMP.  We don't yet support
         * ROLLOVER.
         *
         * SOA: RFC1996
         * Check that 'from' is a valid notify source, (zone->masters).
         *      Return DNS_R_REFUSED if not.
         *
         * If the notify message contains a serial number check it
         * against the zones serial and return if <= current serial
         *
         * If a refresh check is progress, if so just record the
         * fact we received a NOTIFY and from where and return.
         * We will perform a new refresh check when the current one
         * completes. Return ISC_R_SUCCESS.
         *
         * Otherwise initiate a refresh check using 'from' as the
         * first address to check.  Return ISC_R_SUCCESS.
         */

        isc_sockaddr_format(from, fromtext, sizeof(fromtext));

        /*
         *  We only handle NOTIFY (SOA) at the present.
         */
        LOCK_ZONE(zone);
        if (isc_sockaddr_pf(from) == PF_INET)
                inc_stats(zone, dns_zonestatscounter_notifyinv4);
        else
                inc_stats(zone, dns_zonestatscounter_notifyinv6);
        if (msg->counts[DNS_SECTION_QUESTION] == 0 ||
            dns_message_findname(msg, DNS_SECTION_QUESTION, &zone->origin,
                                 dns_rdatatype_soa, dns_rdatatype_none,
                                 NULL, NULL) != ISC_R_SUCCESS) {
                UNLOCK_ZONE(zone);
                if (msg->counts[DNS_SECTION_QUESTION] == 0) {
                        dns_zone_log(zone, ISC_LOG_NOTICE,
                                     "NOTIFY with no "
                                     "question section from: %s", fromtext);
                        return (DNS_R_FORMERR);
                }
                dns_zone_log(zone, ISC_LOG_NOTICE,
                             "NOTIFY zone does not match");
                return (DNS_R_NOTIMP);
        }

        /*
         * If we are a master zone just succeed.
         */
        if (zone->type == dns_zone_master) {
                UNLOCK_ZONE(zone);
                return (ISC_R_SUCCESS);
        }

        isc_netaddr_fromsockaddr(&netaddr, from);
        for (i = 0; i < zone->masterscnt; i++) {
                if (isc_sockaddr_eqaddr(from, &zone->masters[i]))
                        break;
                if (zone->view->aclenv.match_mapped &&
                    IN6_IS_ADDR_V4MAPPED(&from->type.sin6.sin6_addr) &&
                    isc_sockaddr_pf(&zone->masters[i]) == AF_INET) {
                        isc_netaddr_t na1, na2;
                        isc_netaddr_fromv4mapped(&na1, &netaddr);
                        isc_netaddr_fromsockaddr(&na2, &zone->masters[i]);
                        if (isc_netaddr_equal(&na1, &na2))
                                break;
                }
        }

        /*
         * Accept notify requests from non masters if they are on
         * 'zone->notify_acl'.
         */
        if (i >= zone->masterscnt && zone->notify_acl != NULL &&
            dns_acl_match(&netaddr, NULL, zone->notify_acl,
                          &zone->view->aclenv,
                          &match, NULL) == ISC_R_SUCCESS &&
            match > 0)
        {
                /* Accept notify. */
        } else if (i >= zone->masterscnt) {
                UNLOCK_ZONE(zone);
                dns_zone_log(zone, ISC_LOG_INFO,
                             "refused notify from non-master: %s", fromtext);
                inc_stats(zone, dns_zonestatscounter_notifyrej);
                return (DNS_R_REFUSED);
        }

        /*
         * If the zone is loaded and there are answers check the serial
         * to see if we need to do a refresh.  Do not worry about this
         * check if we are a dialup zone as we use the notify request
         * to trigger a refresh check.
         */
        if (msg->counts[DNS_SECTION_ANSWER] > 0 &&
            DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED) &&
            !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NOREFRESH)) {
                result = dns_message_findname(msg, DNS_SECTION_ANSWER,
                                              &zone->origin,
                                              dns_rdatatype_soa,
                                              dns_rdatatype_none, NULL,
                                              &rdataset);
                if (result == ISC_R_SUCCESS)
                        result = dns_rdataset_first(rdataset);
                if (result == ISC_R_SUCCESS) {
                        isc_uint32_t serial = 0, oldserial;

                        dns_rdataset_current(rdataset, &rdata);
                        result = dns_rdata_tostruct(&rdata, &soa, NULL);
                        RUNTIME_CHECK(result == ISC_R_SUCCESS);
                        serial = soa.serial;
                        /*
                         * The following should safely be performed without DB
                         * lock and succeed in this context.
                         */
                        result = zone_get_from_db(zone, zone->db, NULL, NULL,
                                                  &oldserial, NULL, NULL, NULL,
                                                  NULL, NULL);
                        RUNTIME_CHECK(result == ISC_R_SUCCESS);
                        if (isc_serial_le(serial, oldserial)) {
                                dns_zone_log(zone,
                                             ISC_LOG_INFO,
                                             "notify from %s: "
                                             "zone is up to date",
                                             fromtext);
                                UNLOCK_ZONE(zone);
                                return (ISC_R_SUCCESS);
                        }
                }
        }

        /*
         * If we got this far and there was a refresh in progress just
         * let it complete.  Record where we got the notify from so we
         * can perform a refresh check when the current one completes
         */
        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_REFRESH)) {
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDREFRESH);
                zone->notifyfrom = *from;
                UNLOCK_ZONE(zone);
                dns_zone_log(zone, ISC_LOG_INFO,
                             "notify from %s: refresh in progress, "
                             "refresh check queued",
                             fromtext);
                return (ISC_R_SUCCESS);
        }
        zone->notifyfrom = *from;
        local = zone->masteraddr;
        remote = zone->sourceaddr;
        UNLOCK_ZONE(zone);
        dns_zonemgr_unreachabledel(zone->zmgr, &local, &remote);
        dns_zone_refresh(zone);
        return (ISC_R_SUCCESS);
}

void
dns_zone_setnotifyacl(dns_zone_t *zone, dns_acl_t *acl) {

        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        if (zone->notify_acl != NULL)
                dns_acl_detach(&zone->notify_acl);
        dns_acl_attach(acl, &zone->notify_acl);
        UNLOCK_ZONE(zone);
}

void
dns_zone_setqueryacl(dns_zone_t *zone, dns_acl_t *acl) {

        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        if (zone->query_acl != NULL)
                dns_acl_detach(&zone->query_acl);
        dns_acl_attach(acl, &zone->query_acl);
        UNLOCK_ZONE(zone);
}

void
dns_zone_setqueryonacl(dns_zone_t *zone, dns_acl_t *acl) {

        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        if (zone->queryon_acl != NULL)
                dns_acl_detach(&zone->queryon_acl);
        dns_acl_attach(acl, &zone->queryon_acl);
        UNLOCK_ZONE(zone);
}

void
dns_zone_setupdateacl(dns_zone_t *zone, dns_acl_t *acl) {

        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        if (zone->update_acl != NULL)
                dns_acl_detach(&zone->update_acl);
        dns_acl_attach(acl, &zone->update_acl);
        UNLOCK_ZONE(zone);
}

void
dns_zone_setforwardacl(dns_zone_t *zone, dns_acl_t *acl) {

        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        if (zone->forward_acl != NULL)
                dns_acl_detach(&zone->forward_acl);
        dns_acl_attach(acl, &zone->forward_acl);
        UNLOCK_ZONE(zone);
}

void
dns_zone_setxfracl(dns_zone_t *zone, dns_acl_t *acl) {

        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        if (zone->xfr_acl != NULL)
                dns_acl_detach(&zone->xfr_acl);
        dns_acl_attach(acl, &zone->xfr_acl);
        UNLOCK_ZONE(zone);
}

dns_acl_t *
dns_zone_getnotifyacl(dns_zone_t *zone) {

        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->notify_acl);
}

dns_acl_t *
dns_zone_getqueryacl(dns_zone_t *zone) {

        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->query_acl);
}

dns_acl_t *
dns_zone_getqueryonacl(dns_zone_t *zone) {

        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->queryon_acl);
}

dns_acl_t *
dns_zone_getupdateacl(dns_zone_t *zone) {

        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->update_acl);
}

dns_acl_t *
dns_zone_getforwardacl(dns_zone_t *zone) {

        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->forward_acl);
}

dns_acl_t *
dns_zone_getxfracl(dns_zone_t *zone) {

        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->xfr_acl);
}

void
dns_zone_clearupdateacl(dns_zone_t *zone) {

        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        if (zone->update_acl != NULL)
                dns_acl_detach(&zone->update_acl);
        UNLOCK_ZONE(zone);
}

void
dns_zone_clearforwardacl(dns_zone_t *zone) {

        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        if (zone->forward_acl != NULL)
                dns_acl_detach(&zone->forward_acl);
        UNLOCK_ZONE(zone);
}

void
dns_zone_clearnotifyacl(dns_zone_t *zone) {

        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        if (zone->notify_acl != NULL)
                dns_acl_detach(&zone->notify_acl);
        UNLOCK_ZONE(zone);
}

void
dns_zone_clearqueryacl(dns_zone_t *zone) {

        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        if (zone->query_acl != NULL)
                dns_acl_detach(&zone->query_acl);
        UNLOCK_ZONE(zone);
}

void
dns_zone_clearqueryonacl(dns_zone_t *zone) {

        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        if (zone->queryon_acl != NULL)
                dns_acl_detach(&zone->queryon_acl);
        UNLOCK_ZONE(zone);
}

void
dns_zone_clearxfracl(dns_zone_t *zone) {

        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        if (zone->xfr_acl != NULL)
                dns_acl_detach(&zone->xfr_acl);
        UNLOCK_ZONE(zone);
}

isc_boolean_t
dns_zone_getupdatedisabled(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));
        return (zone->update_disabled);

}

void
dns_zone_setupdatedisabled(dns_zone_t *zone, isc_boolean_t state) {
        REQUIRE(DNS_ZONE_VALID(zone));
        zone->update_disabled = state;
}

isc_boolean_t
dns_zone_getzeronosoattl(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));
        return (zone->zero_no_soa_ttl);

}

void
dns_zone_setzeronosoattl(dns_zone_t *zone, isc_boolean_t state) {
        REQUIRE(DNS_ZONE_VALID(zone));
        zone->zero_no_soa_ttl = state;
}

void
dns_zone_setchecknames(dns_zone_t *zone, dns_severity_t severity) {

        REQUIRE(DNS_ZONE_VALID(zone));

        zone->check_names = severity;
}

dns_severity_t
dns_zone_getchecknames(dns_zone_t *zone) {

        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->check_names);
}

void
dns_zone_setjournalsize(dns_zone_t *zone, isc_int32_t size) {

        REQUIRE(DNS_ZONE_VALID(zone));

        zone->journalsize = size;
}

isc_int32_t
dns_zone_getjournalsize(dns_zone_t *zone) {

        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->journalsize);
}

static void
zone_namerd_tostr(dns_zone_t *zone, char *buf, size_t length) {
        isc_result_t result = ISC_R_FAILURE;
        isc_buffer_t buffer;

        REQUIRE(buf != NULL);
        REQUIRE(length > 1U);

        /*
         * Leave space for terminating '\0'.
         */
        isc_buffer_init(&buffer, buf, length - 1);
        if (dns_name_dynamic(&zone->origin))
                result = dns_name_totext(&zone->origin, ISC_TRUE, &buffer);
        if (result != ISC_R_SUCCESS &&
            isc_buffer_availablelength(&buffer) >= (sizeof("<UNKNOWN>") - 1))
                isc_buffer_putstr(&buffer, "<UNKNOWN>");

        if (isc_buffer_availablelength(&buffer) > 0)
                isc_buffer_putstr(&buffer, "/");
        (void)dns_rdataclass_totext(zone->rdclass, &buffer);

        if (zone->view != NULL && strcmp(zone->view->name, "_bind") != 0 &&
            strcmp(zone->view->name, "_default") != 0 &&
            strlen(zone->view->name) < isc_buffer_availablelength(&buffer)) {
                isc_buffer_putstr(&buffer, "/");
                isc_buffer_putstr(&buffer, zone->view->name);
        }

        buf[isc_buffer_usedlength(&buffer)] = '\0';
}

static void
zone_name_tostr(dns_zone_t *zone, char *buf, size_t length) {
        isc_result_t result = ISC_R_FAILURE;
        isc_buffer_t buffer;

        REQUIRE(buf != NULL);
        REQUIRE(length > 1U);

        /*
         * Leave space for terminating '\0'.
         */
        isc_buffer_init(&buffer, buf, length - 1);
        if (dns_name_dynamic(&zone->origin))
                result = dns_name_totext(&zone->origin, ISC_TRUE, &buffer);
        if (result != ISC_R_SUCCESS &&
            isc_buffer_availablelength(&buffer) >= (sizeof("<UNKNOWN>") - 1))
                isc_buffer_putstr(&buffer, "<UNKNOWN>");

        buf[isc_buffer_usedlength(&buffer)] = '\0';
}

static void
zone_rdclass_tostr(dns_zone_t *zone, char *buf, size_t length) {
        isc_buffer_t buffer;

        REQUIRE(buf != NULL);
        REQUIRE(length > 1U);

        /*
         * Leave space for terminating '\0'.
         */
        isc_buffer_init(&buffer, buf, length - 1);
        (void)dns_rdataclass_totext(zone->rdclass, &buffer);

        buf[isc_buffer_usedlength(&buffer)] = '\0';
}

static void
zone_viewname_tostr(dns_zone_t *zone, char *buf, size_t length) {
        isc_buffer_t buffer;

        REQUIRE(buf != NULL);
        REQUIRE(length > 1U);


        /*
         * Leave space for terminating '\0'.
         */
        isc_buffer_init(&buffer, buf, length - 1);

        if (zone->view == NULL) {
                isc_buffer_putstr(&buffer, "_none");
        } else if (strlen(zone->view->name)
                   < isc_buffer_availablelength(&buffer)) {
                isc_buffer_putstr(&buffer, zone->view->name);
        } else {
                isc_buffer_putstr(&buffer, "_toolong");
        }

        buf[isc_buffer_usedlength(&buffer)] = '\0';
}

void
dns_zone_name(dns_zone_t *zone, char *buf, size_t length) {
        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(buf != NULL);
        zone_namerd_tostr(zone, buf, length);
}

static void
notify_log(dns_zone_t *zone, int level, const char *fmt, ...) {
        va_list ap;
        char message[4096];

        if (isc_log_wouldlog(dns_lctx, level) == ISC_FALSE)
                return;

        va_start(ap, fmt);
        vsnprintf(message, sizeof(message), fmt, ap);
        va_end(ap);
        isc_log_write(dns_lctx, DNS_LOGCATEGORY_NOTIFY, DNS_LOGMODULE_ZONE,
                      level, "zone %s: %s", zone->strnamerd, message);
}

void
dns_zone_logc(dns_zone_t *zone, isc_logcategory_t *category,
              int level, const char *fmt, ...) {
        va_list ap;
        char message[4096];

        if (isc_log_wouldlog(dns_lctx, level) == ISC_FALSE)
                return;

        va_start(ap, fmt);
        vsnprintf(message, sizeof(message), fmt, ap);
        va_end(ap);
        isc_log_write(dns_lctx, category, DNS_LOGMODULE_ZONE,
                      level, "%s %s: %s", (zone->type == dns_zone_key) ?
                      "managed-keys-zone" : "zone", zone->strnamerd, message);
}

void
dns_zone_log(dns_zone_t *zone, int level, const char *fmt, ...) {
        va_list ap;
        char message[4096];

        if (isc_log_wouldlog(dns_lctx, level) == ISC_FALSE)
                return;

        va_start(ap, fmt);
        vsnprintf(message, sizeof(message), fmt, ap);
        va_end(ap);
        isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL, DNS_LOGMODULE_ZONE,
                      level, "%s %s: %s", (zone->type == dns_zone_key) ?
                      "managed-keys-zone" : "zone", zone->strnamerd, message);
}

static void
zone_debuglog(dns_zone_t *zone, const char *me, int debuglevel,
              const char *fmt, ...)
{
        va_list ap;
        char message[4096];
        int level = ISC_LOG_DEBUG(debuglevel);

        if (isc_log_wouldlog(dns_lctx, level) == ISC_FALSE)
                return;

        va_start(ap, fmt);
        vsnprintf(message, sizeof(message), fmt, ap);
        va_end(ap);
        isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL, DNS_LOGMODULE_ZONE,
                      level, "%s: %s %s: %s", me, zone->type != dns_zone_key ?
                      "zone" : "managed-keys-zone", zone->strnamerd, message);
}

static int
message_count(dns_message_t *msg, dns_section_t section, dns_rdatatype_t type)
{
        isc_result_t result;
        dns_name_t *name;
        dns_rdataset_t *curr;
        int count = 0;

        result = dns_message_firstname(msg, section);
        while (result == ISC_R_SUCCESS) {
                name = NULL;
                dns_message_currentname(msg, section, &name);

                for (curr = ISC_LIST_TAIL(name->list); curr != NULL;
                     curr = ISC_LIST_PREV(curr, link)) {
                        if (curr->type == type)
                                count++;
                }
                result = dns_message_nextname(msg, section);
        }

        return (count);
}

void
dns_zone_setmaxxfrin(dns_zone_t *zone, isc_uint32_t maxxfrin) {
        REQUIRE(DNS_ZONE_VALID(zone));

        zone->maxxfrin = maxxfrin;
}

isc_uint32_t
dns_zone_getmaxxfrin(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->maxxfrin);
}

void
dns_zone_setmaxxfrout(dns_zone_t *zone, isc_uint32_t maxxfrout) {
        REQUIRE(DNS_ZONE_VALID(zone));
        zone->maxxfrout = maxxfrout;
}

isc_uint32_t
dns_zone_getmaxxfrout(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->maxxfrout);
}

dns_zonetype_t
dns_zone_gettype(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->type);
}

dns_name_t *
dns_zone_getorigin(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        return (&zone->origin);
}

void
dns_zone_settask(dns_zone_t *zone, isc_task_t *task) {
        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        if (zone->task != NULL)
                isc_task_detach(&zone->task);
        isc_task_attach(task, &zone->task);
        ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
        if (zone->db != NULL)
                dns_db_settask(zone->db, zone->task);
        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
        UNLOCK_ZONE(zone);
}

void
dns_zone_gettask(dns_zone_t *zone, isc_task_t **target) {
        REQUIRE(DNS_ZONE_VALID(zone));
        isc_task_attach(zone->task, target);
}

void
dns_zone_setidlein(dns_zone_t *zone, isc_uint32_t idlein) {
        REQUIRE(DNS_ZONE_VALID(zone));

        if (idlein == 0)
                idlein = DNS_DEFAULT_IDLEIN;
        zone->idlein = idlein;
}

isc_uint32_t
dns_zone_getidlein(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->idlein);
}

void
dns_zone_setidleout(dns_zone_t *zone, isc_uint32_t idleout) {
        REQUIRE(DNS_ZONE_VALID(zone));

        zone->idleout = idleout;
}

isc_uint32_t
dns_zone_getidleout(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->idleout);
}

static void
notify_done(isc_task_t *task, isc_event_t *event) {
        dns_requestevent_t *revent = (dns_requestevent_t *)event;
        dns_notify_t *notify;
        isc_result_t result;
        dns_message_t *message = NULL;
        isc_buffer_t buf;
        char rcode[128];
        char addrbuf[ISC_SOCKADDR_FORMATSIZE];

        UNUSED(task);

        notify = event->ev_arg;
        REQUIRE(DNS_NOTIFY_VALID(notify));
        INSIST(task == notify->zone->task);

        isc_buffer_init(&buf, rcode, sizeof(rcode));
        isc_sockaddr_format(&notify->dst, addrbuf, sizeof(addrbuf));

        result = revent->result;
        if (result == ISC_R_SUCCESS)
                result = dns_message_create(notify->zone->mctx,
                                            DNS_MESSAGE_INTENTPARSE, &message);
        if (result == ISC_R_SUCCESS)
                result = dns_request_getresponse(revent->request, message,
                                        DNS_MESSAGEPARSE_PRESERVEORDER);
        if (result == ISC_R_SUCCESS)
                result = dns_rcode_totext(message->rcode, &buf);
        if (result == ISC_R_SUCCESS)
                notify_log(notify->zone, ISC_LOG_DEBUG(3),
                           "notify response from %s: %.*s",
                           addrbuf, (int)buf.used, rcode);
        else
                notify_log(notify->zone, ISC_LOG_DEBUG(2),
                           "notify to %s failed: %s", addrbuf,
                           dns_result_totext(result));

        /*
         * Old bind's return formerr if they see a soa record.  Retry w/o
         * the soa if we see a formerr and had sent a SOA.
         */
        isc_event_free(&event);
        if (message != NULL && message->rcode == dns_rcode_formerr &&
            (notify->flags & DNS_NOTIFY_NOSOA) == 0) {
                notify->flags |= DNS_NOTIFY_NOSOA;
                dns_request_destroy(&notify->request);
                result = notify_send_queue(notify);
                if (result != ISC_R_SUCCESS)
                        notify_destroy(notify, ISC_FALSE);
        } else {
                if (result == ISC_R_TIMEDOUT)
                        notify_log(notify->zone, ISC_LOG_DEBUG(1),
                                   "notify to %s: retries exceeded", addrbuf);
                notify_destroy(notify, ISC_FALSE);
        }
        if (message != NULL)
                dns_message_destroy(&message);
}

isc_result_t
dns_zone_replacedb(dns_zone_t *zone, dns_db_t *db, isc_boolean_t dump) {
        isc_result_t result;

        REQUIRE(DNS_ZONE_VALID(zone));
        LOCK_ZONE(zone);
        ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_write);
        result = zone_replacedb(zone, db, dump);
        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_write);
        UNLOCK_ZONE(zone);
        return (result);
}

static isc_result_t
zone_replacedb(dns_zone_t *zone, dns_db_t *db, isc_boolean_t dump) {
        dns_dbversion_t *ver;
        isc_result_t result;
        unsigned int soacount = 0;
        unsigned int nscount = 0;

        /*
         * 'zone' and 'zonedb' locked by caller.
         */
        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(LOCKED_ZONE(zone));

        result = zone_get_from_db(zone, db, &nscount, &soacount,
                                  NULL, NULL, NULL, NULL, NULL, NULL);
        if (result == ISC_R_SUCCESS) {
                if (soacount != 1) {
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "has %d SOA records", soacount);
                        result = DNS_R_BADZONE;
                }
                if (nscount == 0 && zone->type != dns_zone_key) {
                        dns_zone_log(zone, ISC_LOG_ERROR, "has no NS records");
                        result = DNS_R_BADZONE;
                }
                if (result != ISC_R_SUCCESS)
                        return (result);
        } else {
                dns_zone_log(zone, ISC_LOG_ERROR,
                            "retrieving SOA and NS records failed: %s",
                            dns_result_totext(result));
                return (result);
        }

        result = check_nsec3param(zone, db);
        if (result != ISC_R_SUCCESS)
                return (result);

        ver = NULL;
        dns_db_currentversion(db, &ver);

        /*
         * The initial version of a slave zone is always dumped;
         * subsequent versions may be journaled instead if this
         * is enabled in the configuration.
         */
        if (zone->db != NULL && zone->journal != NULL &&
            DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IXFRFROMDIFFS) &&
            !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FORCEXFER)) {
                isc_uint32_t serial, oldserial;

                dns_zone_log(zone, ISC_LOG_DEBUG(3), "generating diffs");

                result = dns_db_getsoaserial(db, ver, &serial);
                if (result != ISC_R_SUCCESS) {
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "ixfr-from-differences: unable to get "
                                     "new serial");
                        goto fail;
                }

                /*
                 * This is checked in zone_postload() for master zones.
                 */
                result = zone_get_from_db(zone, zone->db, NULL, NULL,
                                          &oldserial, NULL, NULL, NULL, NULL,
                                          NULL);
                RUNTIME_CHECK(result == ISC_R_SUCCESS);
                if (zone->type == dns_zone_slave &&
                    !isc_serial_gt(serial, oldserial)) {
                        isc_uint32_t serialmin, serialmax;
                        serialmin = (oldserial + 1) & 0xffffffffU;
                        serialmax = (oldserial + 0x7fffffffU) & 0xffffffffU;
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "ixfr-from-differences: failed: "
                                     "new serial (%u) out of range [%u - %u]",
                                     serial, serialmin, serialmax);
                        result = ISC_R_RANGE;
                        goto fail;
                }

                result = dns_db_diff(zone->mctx, db, ver, zone->db, NULL,
                                     zone->journal);
                if (result != ISC_R_SUCCESS)
                        goto fail;
                if (dump)
                        zone_needdump(zone, DNS_DUMP_DELAY);
                else if (zone->journalsize != -1) {
                        result = dns_journal_compact(zone->mctx, zone->journal,
                                                     serial, zone->journalsize);
                        switch (result) {
                        case ISC_R_SUCCESS:
                        case ISC_R_NOSPACE:
                        case ISC_R_NOTFOUND:
                                dns_zone_log(zone, ISC_LOG_DEBUG(3),
                                             "dns_journal_compact: %s",
                                             dns_result_totext(result));
                                break;
                        default:
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "dns_journal_compact failed: %s",
                                             dns_result_totext(result));
                                break;
                        }
                }
        } else {
                if (dump && zone->masterfile != NULL) {
                        /*
                         * If DNS_ZONEFLG_FORCEXFER was set we don't want
                         * to keep the old masterfile.
                         */
                        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FORCEXFER) &&
                            remove(zone->masterfile) < 0 && errno != ENOENT) {
                                char strbuf[ISC_STRERRORSIZE];
                                isc__strerror(errno, strbuf, sizeof(strbuf));
                                isc_log_write(dns_lctx,
                                              DNS_LOGCATEGORY_GENERAL,
                                              DNS_LOGMODULE_ZONE,
                                              ISC_LOG_WARNING,
                                              "unable to remove masterfile "
                                              "'%s': '%s'",
                                              zone->masterfile, strbuf);
                        }
                        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_LOADED) == 0)
                                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NODELAY);
                        else
                                zone_needdump(zone, 0);
                }
                if (dump && zone->journal != NULL) {
                        /*
                         * The in-memory database just changed, and
                         * because 'dump' is set, it didn't change by
                         * being loaded from disk.  Also, we have not
                         * journaled diffs for this change.
                         * Therefore, the on-disk journal is missing
                         * the deltas for this change.  Since it can
                         * no longer be used to bring the zone
                         * up-to-date, it is useless and should be
                         * removed.
                         */
                        isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
                                      DNS_LOGMODULE_ZONE, ISC_LOG_DEBUG(3),
                                      "removing journal file");
                        if (remove(zone->journal) < 0 && errno != ENOENT) {
                                char strbuf[ISC_STRERRORSIZE];
                                isc__strerror(errno, strbuf, sizeof(strbuf));
                                isc_log_write(dns_lctx,
                                              DNS_LOGCATEGORY_GENERAL,
                                              DNS_LOGMODULE_ZONE,
                                              ISC_LOG_WARNING,
                                              "unable to remove journal "
                                              "'%s': '%s'",
                                              zone->journal, strbuf);
                        }
                }
        }

        dns_db_closeversion(db, &ver, ISC_FALSE);

        isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
                      DNS_LOGMODULE_ZONE, ISC_LOG_DEBUG(3),
                      "replacing zone database");

        if (zone->db != NULL)
                zone_detachdb(zone);
        zone_attachdb(zone, db);
        dns_db_settask(zone->db, zone->task);
        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_LOADED|DNS_ZONEFLG_NEEDNOTIFY);
        return (ISC_R_SUCCESS);

 fail:
        dns_db_closeversion(db, &ver, ISC_FALSE);
        return (result);
}

/* The caller must hold the dblock as a writer. */
static inline void
zone_attachdb(dns_zone_t *zone, dns_db_t *db) {
        REQUIRE(zone->db == NULL && db != NULL);

        dns_db_attach(db, &zone->db);
        if (zone->acache != NULL) {
                isc_result_t result;
                result = dns_acache_setdb(zone->acache, db);
                if (result != ISC_R_SUCCESS && result != ISC_R_EXISTS) {
                        UNEXPECTED_ERROR(__FILE__, __LINE__,
                                         "dns_acache_setdb() failed: %s",
                                         isc_result_totext(result));
                }
        }
}

/* The caller must hold the dblock as a writer. */
static inline void
zone_detachdb(dns_zone_t *zone) {
        REQUIRE(zone->db != NULL);

        if (zone->acache != NULL)
                (void)dns_acache_putdb(zone->acache, zone->db);
        dns_db_detach(&zone->db);
}

static void
zone_xfrdone(dns_zone_t *zone, isc_result_t result) {
        isc_time_t now;
        isc_boolean_t again = ISC_FALSE;
        unsigned int soacount;
        unsigned int nscount;
        isc_uint32_t serial, refresh, retry, expire, minimum;
        isc_result_t xfrresult = result;
        isc_boolean_t free_needed;

        REQUIRE(DNS_ZONE_VALID(zone));

        dns_zone_log(zone, ISC_LOG_DEBUG(1),
                     "zone transfer finished: %s", dns_result_totext(result));

        LOCK_ZONE(zone);
        INSIST((zone->flags & DNS_ZONEFLG_REFRESH) != 0);
        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_REFRESH);
        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_SOABEFOREAXFR);

        TIME_NOW(&now);
        switch (result) {
        case ISC_R_SUCCESS:
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDNOTIFY);
                /*FALLTHROUGH*/
        case DNS_R_UPTODATE:
                DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_FORCEXFER);
                /*
                 * Has the zone expired underneath us?
                 */
                ZONEDB_LOCK(&zone->dblock, isc_rwlocktype_read);
                if (zone->db == NULL) {
                        ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
                        goto same_master;
                }

                /*
                 * Update the zone structure's data from the actual
                 * SOA received.
                 */
                nscount = 0;
                soacount = 0;
                INSIST(zone->db != NULL);
                result = zone_get_from_db(zone, zone->db, &nscount,
                                          &soacount, &serial, &refresh,
                                          &retry, &expire, &minimum, NULL);
                ZONEDB_UNLOCK(&zone->dblock, isc_rwlocktype_read);
                if (result == ISC_R_SUCCESS) {
                        if (soacount != 1)
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "transferred zone "
                                             "has %d SOA record%s", soacount,
                                             (soacount != 0) ? "s" : "");
                        if (nscount == 0) {
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "transferred zone "
                                             "has no NS records");
                                if (DNS_ZONE_FLAG(zone,
                                                  DNS_ZONEFLG_HAVETIMERS)) {
                                        zone->refresh = DNS_ZONE_DEFAULTREFRESH;
                                        zone->retry = DNS_ZONE_DEFAULTRETRY;
                                }
                                DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_HAVETIMERS);
                                zone_unload(zone);
                                goto next_master;
                        }
                        zone->refresh = RANGE(refresh, zone->minrefresh,
                                              zone->maxrefresh);
                        zone->retry = RANGE(retry, zone->minretry,
                                            zone->maxretry);
                        zone->expire = RANGE(expire,
                                             zone->refresh + zone->retry,
                                             DNS_MAX_EXPIRE);
                        zone->minimum = minimum;
                        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_HAVETIMERS);
                }

                /*
                 * Set our next update/expire times.
                 */
                if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDREFRESH)) {
                        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NEEDREFRESH);
                        zone->refreshtime = now;
                        DNS_ZONE_TIME_ADD(&now, zone->expire,
                                          &zone->expiretime);
                } else {
                        DNS_ZONE_JITTER_ADD(&now, zone->refresh,
                                            &zone->refreshtime);
                        DNS_ZONE_TIME_ADD(&now, zone->expire,
                                          &zone->expiretime);
                }
                if (result == ISC_R_SUCCESS && xfrresult == ISC_R_SUCCESS) {
                        char buf[DNS_NAME_FORMATSIZE + sizeof(": TSIG ''")];
                        if (zone->tsigkey != NULL) {
                                char namebuf[DNS_NAME_FORMATSIZE];
                                dns_name_format(&zone->tsigkey->name, namebuf,
                                                sizeof(namebuf));
                                snprintf(buf, sizeof(buf), ": TSIG '%s'",
                                         namebuf);
                        } else
                                buf[0] = '\0';
                        dns_zone_log(zone, ISC_LOG_INFO,
                                     "transferred serial %u%s",
                                     serial, buf);
                }

                /*
                 * This is not necessary if we just performed a AXFR
                 * however it is necessary for an IXFR / UPTODATE and
                 * won't hurt with an AXFR.
                 */
                if (zone->masterfile != NULL || zone->journal != NULL) {
                        result = ISC_R_FAILURE;
                        if (zone->journal != NULL)
                                result = isc_file_settime(zone->journal, &now);
                        if (result != ISC_R_SUCCESS &&
                            zone->masterfile != NULL)
                                result = isc_file_settime(zone->masterfile,
                                                          &now);
                        /* Someone removed the file from underneath us! */
                        if (result == ISC_R_FILENOTFOUND &&
                            zone->masterfile != NULL) {
                                unsigned int delay = DNS_DUMP_DELAY;
                                if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NODELAY))
                                        delay = 0;
                                zone_needdump(zone, delay);
                        } else if (result != ISC_R_SUCCESS)
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "transfer: could not set file "
                                             "modification time of '%s': %s",
                                             zone->masterfile,
                                             dns_result_totext(result));
                }
                DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NODELAY);
                inc_stats(zone, dns_zonestatscounter_xfrsuccess);
                break;

        case DNS_R_BADIXFR:
                /* Force retry with AXFR. */
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLAG_NOIXFR);
                goto same_master;

        default:
        next_master:
                /*
                 * Skip to next failed / untried master.
                 */
                do {
                        zone->curmaster++;
                } while (zone->curmaster < zone->masterscnt &&
                         zone->mastersok[zone->curmaster]);
                /* FALLTHROUGH */
        same_master:
                if (zone->curmaster >= zone->masterscnt) {
                        zone->curmaster = 0;
                        if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_USEALTXFRSRC) &&
                            !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_USEALTXFRSRC)) {
                                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_REFRESH);
                                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_USEALTXFRSRC);
                                while (zone->curmaster < zone->masterscnt &&
                                       zone->mastersok[zone->curmaster])
                                        zone->curmaster++;
                                again = ISC_TRUE;
                        } else
                                DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_USEALTXFRSRC);
                } else {
                        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_REFRESH);
                        again = ISC_TRUE;
                }
                inc_stats(zone, dns_zonestatscounter_xfrfail);
                break;
        }
        zone_settimer(zone, &now);

        /*
         * If creating the transfer object failed, zone->xfr is NULL.
         * Otherwise, we are called as the done callback of a zone
         * transfer object that just entered its shutting-down
         * state.  Since we are no longer responsible for shutting
         * it down, we can detach our reference.
         */
        if (zone->xfr != NULL)
                dns_xfrin_detach(&zone->xfr);

        if (zone->tsigkey != NULL)
                dns_tsigkey_detach(&zone->tsigkey);

        /*
         * Handle any deferred journal compaction.
         */
        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_NEEDCOMPACT)) {
                result = dns_journal_compact(zone->mctx, zone->journal,
                                             zone->compact_serial,
                                             zone->journalsize);
                switch (result) {
                case ISC_R_SUCCESS:
                case ISC_R_NOSPACE:
                case ISC_R_NOTFOUND:
                        dns_zone_log(zone, ISC_LOG_DEBUG(3),
                                     "dns_journal_compact: %s",
                                     dns_result_totext(result));
                        break;
                default:
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "dns_journal_compact failed: %s",
                                     dns_result_totext(result));
                        break;
                }
                DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_NEEDCOMPACT);
        }

        /*
         * This transfer finishing freed up a transfer quota slot.
         * Let any other zones waiting for quota have it.
         */
        UNLOCK_ZONE(zone);
        RWLOCK(&zone->zmgr->rwlock, isc_rwlocktype_write);
        ISC_LIST_UNLINK(zone->zmgr->xfrin_in_progress, zone, statelink);
        zone->statelist = NULL;
        zmgr_resume_xfrs(zone->zmgr, ISC_FALSE);
        RWUNLOCK(&zone->zmgr->rwlock, isc_rwlocktype_write);
        LOCK_ZONE(zone);

        /*
         * Retry with a different server if necessary.
         */
        if (again && !DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING))
                queue_soa_query(zone);

        INSIST(zone->irefs > 0);
        zone->irefs--;
        free_needed = exit_check(zone);
        UNLOCK_ZONE(zone);
        if (free_needed)
                zone_free(zone);
}

static void
zone_loaddone(void *arg, isc_result_t result) {
        static char me[] = "zone_loaddone";
        dns_load_t *load = arg;
        dns_zone_t *zone;
        isc_result_t tresult;

        REQUIRE(DNS_LOAD_VALID(load));
        zone = load->zone;

        ENTER;

        tresult = dns_db_endload(load->db, &load->callbacks.add_private);
        if (tresult != ISC_R_SUCCESS &&
            (result == ISC_R_SUCCESS || result == DNS_R_SEENINCLUDE))
                result = tresult;

        LOCK_ZONE(load->zone);
        (void)zone_postload(load->zone, load->db, load->loadtime, result);
        zonemgr_putio(&load->zone->readio);
        DNS_ZONE_CLRFLAG(load->zone, DNS_ZONEFLG_LOADING);
        /*
         * Leave the zone frozen if the reload fails.
         */
        if ((result == ISC_R_SUCCESS || result == DNS_R_SEENINCLUDE) &&
             DNS_ZONE_FLAG(load->zone, DNS_ZONEFLG_THAW))
                zone->update_disabled = ISC_FALSE;
        DNS_ZONE_CLRFLAG(load->zone, DNS_ZONEFLG_THAW);
        UNLOCK_ZONE(load->zone);

        load->magic = 0;
        dns_db_detach(&load->db);
        if (load->zone->lctx != NULL)
                dns_loadctx_detach(&load->zone->lctx);
        dns_zone_idetach(&load->zone);
        isc_mem_putanddetach(&load->mctx, load, sizeof(*load));
}

void
dns_zone_getssutable(dns_zone_t *zone, dns_ssutable_t **table) {
        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(table != NULL);
        REQUIRE(*table == NULL);

        LOCK_ZONE(zone);
        if (zone->ssutable != NULL)
                dns_ssutable_attach(zone->ssutable, table);
        UNLOCK_ZONE(zone);
}

void
dns_zone_setssutable(dns_zone_t *zone, dns_ssutable_t *table) {
        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        if (zone->ssutable != NULL)
                dns_ssutable_detach(&zone->ssutable);
        if (table != NULL)
                dns_ssutable_attach(table, &zone->ssutable);
        UNLOCK_ZONE(zone);
}

void
dns_zone_setsigvalidityinterval(dns_zone_t *zone, isc_uint32_t interval) {
        REQUIRE(DNS_ZONE_VALID(zone));

        zone->sigvalidityinterval = interval;
}

isc_uint32_t
dns_zone_getsigvalidityinterval(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->sigvalidityinterval);
}

void
dns_zone_setsigresigninginterval(dns_zone_t *zone, isc_uint32_t interval) {
        REQUIRE(DNS_ZONE_VALID(zone));

        zone->sigresigninginterval = interval;
}

isc_uint32_t
dns_zone_getsigresigninginterval(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->sigresigninginterval);
}

static void
queue_xfrin(dns_zone_t *zone) {
        const char me[] = "queue_xfrin";
        isc_result_t result;
        dns_zonemgr_t *zmgr = zone->zmgr;

        ENTER;

        INSIST(zone->statelist == NULL);

        RWLOCK(&zmgr->rwlock, isc_rwlocktype_write);
        ISC_LIST_APPEND(zmgr->waiting_for_xfrin, zone, statelink);
        LOCK_ZONE(zone);
        zone->irefs++;
        UNLOCK_ZONE(zone);
        zone->statelist = &zmgr->waiting_for_xfrin;
        result = zmgr_start_xfrin_ifquota(zmgr, zone);
        RWUNLOCK(&zmgr->rwlock, isc_rwlocktype_write);

        if (result == ISC_R_QUOTA) {
                dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_INFO,
                              "zone transfer deferred due to quota");
        } else if (result != ISC_R_SUCCESS) {
                dns_zone_logc(zone, DNS_LOGCATEGORY_XFER_IN, ISC_LOG_ERROR,
                              "starting zone transfer: %s",
                              isc_result_totext(result));
        }
}

/*
 * This event callback is called when a zone has received
 * any necessary zone transfer quota.  This is the time
 * to go ahead and start the transfer.
 */
static void
got_transfer_quota(isc_task_t *task, isc_event_t *event) {
        isc_result_t result;
        dns_peer_t *peer = NULL;
        char master[ISC_SOCKADDR_FORMATSIZE];
        char source[ISC_SOCKADDR_FORMATSIZE];
        dns_rdatatype_t xfrtype;
        dns_zone_t *zone = event->ev_arg;
        isc_netaddr_t masterip;
        isc_sockaddr_t sourceaddr;
        isc_sockaddr_t masteraddr;
        isc_time_t now;
        const char *soa_before = "";

        UNUSED(task);

        INSIST(task == zone->task);

        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING)) {
                result = ISC_R_CANCELED;
                goto cleanup;
        }

        TIME_NOW(&now);

        isc_sockaddr_format(&zone->masteraddr, master, sizeof(master));
        if (dns_zonemgr_unreachable(zone->zmgr, &zone->masteraddr,
                                    &zone->sourceaddr, &now))
        {
                isc_sockaddr_format(&zone->sourceaddr, source, sizeof(source));
                dns_zone_log(zone, ISC_LOG_INFO,
                             "got_transfer_quota: skipping zone transfer as "
                             "master %s (source %s) is unreachable (cached)",
                             master, source);
                result = ISC_R_CANCELED;
                goto cleanup;
        }

        isc_netaddr_fromsockaddr(&masterip, &zone->masteraddr);
        (void)dns_peerlist_peerbyaddr(zone->view->peers, &masterip, &peer);

        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_SOABEFOREAXFR))
                soa_before = "SOA before ";
        /*
         * Decide whether we should request IXFR or AXFR.
         */
        if (zone->db == NULL) {
                dns_zone_log(zone, ISC_LOG_DEBUG(1),
                             "no database exists yet, requesting AXFR of "
                             "initial version from %s", master);
                xfrtype = dns_rdatatype_axfr;
        } else if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_IXFRFROMDIFFS)) {
                dns_zone_log(zone, ISC_LOG_DEBUG(1), "ixfr-from-differences "
                             "set, requesting %sAXFR from %s", soa_before,
                             master);
                if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_SOABEFOREAXFR))
                        xfrtype = dns_rdatatype_soa;
                else
                        xfrtype = dns_rdatatype_axfr;
        } else if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FORCEXFER)) {
                dns_zone_log(zone, ISC_LOG_DEBUG(1),
                             "forced reload, requesting AXFR of "
                             "initial version from %s", master);
                xfrtype = dns_rdatatype_axfr;
        } else if (DNS_ZONE_FLAG(zone, DNS_ZONEFLAG_NOIXFR)) {
                dns_zone_log(zone, ISC_LOG_DEBUG(1),
                             "retrying with AXFR from %s due to "
                             "previous IXFR failure", master);
                xfrtype = dns_rdatatype_axfr;
                LOCK_ZONE(zone);
                DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLAG_NOIXFR);
                UNLOCK_ZONE(zone);
        } else {
                isc_boolean_t use_ixfr = ISC_TRUE;
                if (peer != NULL &&
                    dns_peer_getrequestixfr(peer, &use_ixfr) ==
                    ISC_R_SUCCESS) {
                        ; /* Using peer setting */
                } else {
                        use_ixfr = zone->view->requestixfr;
                }
                if (use_ixfr == ISC_FALSE) {
                        dns_zone_log(zone, ISC_LOG_DEBUG(1),
                                     "IXFR disabled, requesting %sAXFR from %s",
                                     soa_before, master);
                        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_SOABEFOREAXFR))
                                xfrtype = dns_rdatatype_soa;
                        else
                                xfrtype = dns_rdatatype_axfr;
                } else {
                        dns_zone_log(zone, ISC_LOG_DEBUG(1),
                                     "requesting IXFR from %s", master);
                        xfrtype = dns_rdatatype_ixfr;
                }
        }

        /*
         * Determine if we should attempt to sign the request with TSIG.
         */
        result = ISC_R_NOTFOUND;
        /*
         * First, look for a tsig key in the master statement, then
         * try for a server key.
         */
        if ((zone->masterkeynames != NULL) &&
            (zone->masterkeynames[zone->curmaster] != NULL)) {
                dns_view_t *view = dns_zone_getview(zone);
                dns_name_t *keyname = zone->masterkeynames[zone->curmaster];
                result = dns_view_gettsig(view, keyname, &zone->tsigkey);
        }
        if (zone->tsigkey == NULL)
                result = dns_view_getpeertsig(zone->view, &masterip,
                                              &zone->tsigkey);

        if (result != ISC_R_SUCCESS && result != ISC_R_NOTFOUND) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "could not get TSIG key for zone transfer: %s",
                             isc_result_totext(result));
        }

        LOCK_ZONE(zone);
        masteraddr = zone->masteraddr;
        sourceaddr = zone->sourceaddr;
        UNLOCK_ZONE(zone);
        INSIST(isc_sockaddr_pf(&masteraddr) == isc_sockaddr_pf(&sourceaddr));
        result = dns_xfrin_create2(zone, xfrtype, &masteraddr, &sourceaddr,
                                   zone->tsigkey, zone->mctx,
                                   zone->zmgr->timermgr, zone->zmgr->socketmgr,
                                   zone->task, zone_xfrdone, &zone->xfr);
        if (result == ISC_R_SUCCESS) {
                LOCK_ZONE(zone);
                if (xfrtype == dns_rdatatype_axfr) {
                        if (isc_sockaddr_pf(&masteraddr) == PF_INET)
                                inc_stats(zone, dns_zonestatscounter_axfrreqv4);
                        else
                                inc_stats(zone, dns_zonestatscounter_axfrreqv6);
                } else if (xfrtype == dns_rdatatype_ixfr) {
                        if (isc_sockaddr_pf(&masteraddr) == PF_INET)
                                inc_stats(zone, dns_zonestatscounter_ixfrreqv4);
                        else
                                inc_stats(zone, dns_zonestatscounter_ixfrreqv6);
                }
                UNLOCK_ZONE(zone);
        }
 cleanup:
        /*
         * Any failure in this function is handled like a failed
         * zone transfer.  This ensures that we get removed from
         * zmgr->xfrin_in_progress.
         */
        if (result != ISC_R_SUCCESS)
                zone_xfrdone(zone, result);

        isc_event_free(&event);
}

/*
 * Update forwarding support.
 */

static void
forward_destroy(dns_forward_t *forward) {

        forward->magic = 0;
        if (forward->request != NULL)
                dns_request_destroy(&forward->request);
        if (forward->msgbuf != NULL)
                isc_buffer_free(&forward->msgbuf);
        if (forward->zone != NULL) {
                LOCK(&forward->zone->lock);
                if (ISC_LINK_LINKED(forward, link))
                        ISC_LIST_UNLINK(forward->zone->forwards, forward, link);
                UNLOCK(&forward->zone->lock);
                dns_zone_idetach(&forward->zone);
        }
        isc_mem_putanddetach(&forward->mctx, forward, sizeof(*forward));
}

static isc_result_t
sendtomaster(dns_forward_t *forward) {
        isc_result_t result;
        isc_sockaddr_t src;

        LOCK_ZONE(forward->zone);

        if (DNS_ZONE_FLAG(forward->zone, DNS_ZONEFLG_EXITING)) {
                UNLOCK_ZONE(forward->zone);
                return (ISC_R_CANCELED);
        }

        if (forward->which >= forward->zone->masterscnt) {
                UNLOCK_ZONE(forward->zone);
                return (ISC_R_NOMORE);
        }

        forward->addr = forward->zone->masters[forward->which];
        /*
         * Always use TCP regardless of whether the original update
         * used TCP.
         * XXX The timeout may but a bit small if we are far down a
         * transfer graph and the master has to try several masters.
         */
        switch (isc_sockaddr_pf(&forward->addr)) {
        case PF_INET:
                src = forward->zone->xfrsource4;
                break;
        case PF_INET6:
                src = forward->zone->xfrsource6;
                break;
        default:
                result = ISC_R_NOTIMPLEMENTED;
                goto unlock;
        }
        result = dns_request_createraw(forward->zone->view->requestmgr,
                                       forward->msgbuf,
                                       &src, &forward->addr,
                                       DNS_REQUESTOPT_TCP, 15 /* XXX */,
                                       forward->zone->task,
                                       forward_callback, forward,
                                       &forward->request);
        if (result == ISC_R_SUCCESS) {
                if (!ISC_LINK_LINKED(forward, link))
                        ISC_LIST_APPEND(forward->zone->forwards, forward, link);
        }

 unlock:
        UNLOCK_ZONE(forward->zone);
        return (result);
}

static void
forward_callback(isc_task_t *task, isc_event_t *event) {
        const char me[] = "forward_callback";
        dns_requestevent_t *revent = (dns_requestevent_t *)event;
        dns_message_t *msg = NULL;
        char master[ISC_SOCKADDR_FORMATSIZE];
        isc_result_t result;
        dns_forward_t *forward;
        dns_zone_t *zone;

        UNUSED(task);

        forward = revent->ev_arg;
        INSIST(DNS_FORWARD_VALID(forward));
        zone = forward->zone;
        INSIST(DNS_ZONE_VALID(zone));

        ENTER;

        isc_sockaddr_format(&forward->addr, master, sizeof(master));

        if (revent->result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_INFO,
                             "could not forward dynamic update to %s: %s",
                             master, dns_result_totext(revent->result));
                goto next_master;
        }

        result = dns_message_create(zone->mctx, DNS_MESSAGE_INTENTPARSE, &msg);
        if (result != ISC_R_SUCCESS)
                goto next_master;

        result = dns_request_getresponse(revent->request, msg,
                                         DNS_MESSAGEPARSE_PRESERVEORDER |
                                         DNS_MESSAGEPARSE_CLONEBUFFER);
        if (result != ISC_R_SUCCESS)
                goto next_master;

        switch (msg->rcode) {
        /*
         * Pass these rcodes back to client.
         */
        case dns_rcode_noerror:
        case dns_rcode_yxdomain:
        case dns_rcode_yxrrset:
        case dns_rcode_nxrrset:
        case dns_rcode_refused:
        case dns_rcode_nxdomain:
                break;

        /* These should not occur if the masters/zone are valid. */
        case dns_rcode_notzone:
        case dns_rcode_notauth: {
                char rcode[128];
                isc_buffer_t rb;

                isc_buffer_init(&rb, rcode, sizeof(rcode));
                (void)dns_rcode_totext(msg->rcode, &rb);
                dns_zone_log(zone, ISC_LOG_WARNING,
                             "forwarding dynamic update: "
                             "unexpected response: master %s returned: %.*s",
                             master, (int)rb.used, rcode);
                goto next_master;
        }

        /* Try another server for these rcodes. */
        case dns_rcode_formerr:
        case dns_rcode_servfail:
        case dns_rcode_notimp:
        case dns_rcode_badvers:
        default:
                goto next_master;
        }

        /* call callback */
        (forward->callback)(forward->callback_arg, ISC_R_SUCCESS, msg);
        msg = NULL;
        dns_request_destroy(&forward->request);
        forward_destroy(forward);
        isc_event_free(&event);
        return;

 next_master:
        if (msg != NULL)
                dns_message_destroy(&msg);
        isc_event_free(&event);
        forward->which++;
        dns_request_destroy(&forward->request);
        result = sendtomaster(forward);
        if (result != ISC_R_SUCCESS) {
                /* call callback */
                dns_zone_log(zone, ISC_LOG_DEBUG(3),
                             "exhausted dynamic update forwarder list");
                (forward->callback)(forward->callback_arg, result, NULL);
                forward_destroy(forward);
        }
}

isc_result_t
dns_zone_forwardupdate(dns_zone_t *zone, dns_message_t *msg,
                       dns_updatecallback_t callback, void *callback_arg)
{
        dns_forward_t *forward;
        isc_result_t result;
        isc_region_t *mr;

        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(msg != NULL);
        REQUIRE(callback != NULL);

        forward = isc_mem_get(zone->mctx, sizeof(*forward));
        if (forward == NULL)
                return (ISC_R_NOMEMORY);

        forward->request = NULL;
        forward->zone = NULL;
        forward->msgbuf = NULL;
        forward->which = 0;
        forward->mctx = 0;
        forward->callback = callback;
        forward->callback_arg = callback_arg;
        ISC_LINK_INIT(forward, link);
        forward->magic = FORWARD_MAGIC;

        mr = dns_message_getrawmessage(msg);
        if (mr == NULL) {
                result = ISC_R_UNEXPECTEDEND;
                goto cleanup;
        }

        result = isc_buffer_allocate(zone->mctx, &forward->msgbuf, mr->length);
        if (result != ISC_R_SUCCESS)
                goto cleanup;
        result = isc_buffer_copyregion(forward->msgbuf, mr);
        if (result != ISC_R_SUCCESS)
                goto cleanup;

        isc_mem_attach(zone->mctx, &forward->mctx);
        dns_zone_iattach(zone, &forward->zone);
        result = sendtomaster(forward);

 cleanup:
        if (result != ISC_R_SUCCESS) {
                forward_destroy(forward);
        }
        return (result);
}

isc_result_t
dns_zone_next(dns_zone_t *zone, dns_zone_t **next) {
        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(next != NULL && *next == NULL);

        *next = ISC_LIST_NEXT(zone, link);
        if (*next == NULL)
                return (ISC_R_NOMORE);
        else
                return (ISC_R_SUCCESS);
}

isc_result_t
dns_zone_first(dns_zonemgr_t *zmgr, dns_zone_t **first) {
        REQUIRE(DNS_ZONEMGR_VALID(zmgr));
        REQUIRE(first != NULL && *first == NULL);

        *first = ISC_LIST_HEAD(zmgr->zones);
        if (*first == NULL)
                return (ISC_R_NOMORE);
        else
                return (ISC_R_SUCCESS);
}

/***
 ***    Zone manager.
 ***/

isc_result_t
dns_zonemgr_create(isc_mem_t *mctx, isc_taskmgr_t *taskmgr,
                   isc_timermgr_t *timermgr, isc_socketmgr_t *socketmgr,
                   dns_zonemgr_t **zmgrp)
{
        dns_zonemgr_t *zmgr;
        isc_result_t result;
        isc_interval_t interval;

        zmgr = isc_mem_get(mctx, sizeof(*zmgr));
        if (zmgr == NULL)
                return (ISC_R_NOMEMORY);
        zmgr->mctx = NULL;
        zmgr->refs = 1;
        isc_mem_attach(mctx, &zmgr->mctx);
        zmgr->taskmgr = taskmgr;
        zmgr->timermgr = timermgr;
        zmgr->socketmgr = socketmgr;
        zmgr->zonetasks = NULL;
        zmgr->task = NULL;
        zmgr->rl = NULL;
        ISC_LIST_INIT(zmgr->zones);
        ISC_LIST_INIT(zmgr->waiting_for_xfrin);
        ISC_LIST_INIT(zmgr->xfrin_in_progress);
        memset(zmgr->unreachable, 0, sizeof(zmgr->unreachable));
        result = isc_rwlock_init(&zmgr->rwlock, 0, 0);
        if (result != ISC_R_SUCCESS)
                goto free_mem;

        zmgr->transfersin = 10;
        zmgr->transfersperns = 2;

        /* Unreachable lock. */
        result = isc_rwlock_init(&zmgr->urlock, 0, 0);
        if (result != ISC_R_SUCCESS)
                goto free_rwlock;

        /* Create a single task for queueing of SOA queries. */
        result = isc_task_create(taskmgr, 1, &zmgr->task);
        if (result != ISC_R_SUCCESS)
                goto free_urlock;

        isc_task_setname(zmgr->task, "zmgr", zmgr);
        result = isc_ratelimiter_create(mctx, timermgr, zmgr->task,
                                        &zmgr->rl);
        if (result != ISC_R_SUCCESS)
                goto free_task;

        /* default to 20 refresh queries / notifies per second. */
        isc_interval_set(&interval, 0, 1000000000/2);
        result = isc_ratelimiter_setinterval(zmgr->rl, &interval);
        RUNTIME_CHECK(result == ISC_R_SUCCESS);
        isc_ratelimiter_setpertic(zmgr->rl, 10);

        zmgr->iolimit = 1;
        zmgr->ioactive = 0;
        ISC_LIST_INIT(zmgr->high);
        ISC_LIST_INIT(zmgr->low);

        result = isc_mutex_init(&zmgr->iolock);
        if (result != ISC_R_SUCCESS)
                goto free_rl;

        zmgr->magic = ZONEMGR_MAGIC;

        *zmgrp = zmgr;
        return (ISC_R_SUCCESS);

#if 0
 free_iolock:
        DESTROYLOCK(&zmgr->iolock);
#endif
 free_rl:
        isc_ratelimiter_detach(&zmgr->rl);
 free_task:
        isc_task_detach(&zmgr->task);
 free_urlock:
        isc_rwlock_destroy(&zmgr->urlock);
 free_rwlock:
        isc_rwlock_destroy(&zmgr->rwlock);
 free_mem:
        isc_mem_put(zmgr->mctx, zmgr, sizeof(*zmgr));
        isc_mem_detach(&mctx);
        return (result);
}

isc_result_t
dns_zonemgr_managezone(dns_zonemgr_t *zmgr, dns_zone_t *zone) {
        isc_result_t result;

        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(DNS_ZONEMGR_VALID(zmgr));

        if (zmgr->zonetasks == NULL)
                return (ISC_R_FAILURE);

        RWLOCK(&zmgr->rwlock, isc_rwlocktype_write);
        LOCK_ZONE(zone);
        REQUIRE(zone->task == NULL);
        REQUIRE(zone->timer == NULL);
        REQUIRE(zone->zmgr == NULL);

        isc_taskpool_gettask(zmgr->zonetasks, &zone->task);

        /*
         * Set the task name.  The tag will arbitrarily point to one
         * of the zones sharing the task (in practice, the one
         * to be managed last).
         */
        isc_task_setname(zone->task, "zone", zone);

        result = isc_timer_create(zmgr->timermgr, isc_timertype_inactive,
                                  NULL, NULL,
                                  zone->task, zone_timer, zone,
                                  &zone->timer);

        if (result != ISC_R_SUCCESS)
                goto cleanup_task;

        /*
         * The timer "holds" a iref.
         */
        zone->irefs++;
        INSIST(zone->irefs != 0);

        ISC_LIST_APPEND(zmgr->zones, zone, link);
        zone->zmgr = zmgr;
        zmgr->refs++;

        goto unlock;

 cleanup_task:
        isc_task_detach(&zone->task);

 unlock:
        UNLOCK_ZONE(zone);
        RWUNLOCK(&zmgr->rwlock, isc_rwlocktype_write);
        return (result);
}

void
dns_zonemgr_releasezone(dns_zonemgr_t *zmgr, dns_zone_t *zone) {
        isc_boolean_t free_now = ISC_FALSE;

        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(DNS_ZONEMGR_VALID(zmgr));
        REQUIRE(zone->zmgr == zmgr);

        RWLOCK(&zmgr->rwlock, isc_rwlocktype_write);
        LOCK_ZONE(zone);

        ISC_LIST_UNLINK(zmgr->zones, zone, link);
        zone->zmgr = NULL;
        zmgr->refs--;
        if (zmgr->refs == 0)
                free_now = ISC_TRUE;

        UNLOCK_ZONE(zone);
        RWUNLOCK(&zmgr->rwlock, isc_rwlocktype_write);

        if (free_now)
                zonemgr_free(zmgr);
        ENSURE(zone->zmgr == NULL);
}

void
dns_zonemgr_attach(dns_zonemgr_t *source, dns_zonemgr_t **target) {
        REQUIRE(DNS_ZONEMGR_VALID(source));
        REQUIRE(target != NULL && *target == NULL);

        RWLOCK(&source->rwlock, isc_rwlocktype_write);
        REQUIRE(source->refs > 0);
        source->refs++;
        INSIST(source->refs > 0);
        RWUNLOCK(&source->rwlock, isc_rwlocktype_write);
        *target = source;
}

void
dns_zonemgr_detach(dns_zonemgr_t **zmgrp) {
        dns_zonemgr_t *zmgr;
        isc_boolean_t free_now = ISC_FALSE;

        REQUIRE(zmgrp != NULL);
        zmgr = *zmgrp;
        REQUIRE(DNS_ZONEMGR_VALID(zmgr));

        RWLOCK(&zmgr->rwlock, isc_rwlocktype_write);
        zmgr->refs--;
        if (zmgr->refs == 0)
                free_now = ISC_TRUE;
        RWUNLOCK(&zmgr->rwlock, isc_rwlocktype_write);

        if (free_now)
                zonemgr_free(zmgr);
        *zmgrp = NULL;
}

isc_result_t
dns_zonemgr_forcemaint(dns_zonemgr_t *zmgr) {
        dns_zone_t *p;

        REQUIRE(DNS_ZONEMGR_VALID(zmgr));

        RWLOCK(&zmgr->rwlock, isc_rwlocktype_read);
        for (p = ISC_LIST_HEAD(zmgr->zones);
             p != NULL;
             p = ISC_LIST_NEXT(p, link))
        {
                dns_zone_maintenance(p);
        }
        RWUNLOCK(&zmgr->rwlock, isc_rwlocktype_read);

        /*
         * Recent configuration changes may have increased the
         * amount of available transfers quota.  Make sure any
         * transfers currently blocked on quota get started if
         * possible.
         */
        RWLOCK(&zmgr->rwlock, isc_rwlocktype_write);
        zmgr_resume_xfrs(zmgr, ISC_TRUE);
        RWUNLOCK(&zmgr->rwlock, isc_rwlocktype_write);
        return (ISC_R_SUCCESS);
}

void
dns_zonemgr_resumexfrs(dns_zonemgr_t *zmgr) {

        REQUIRE(DNS_ZONEMGR_VALID(zmgr));

        RWLOCK(&zmgr->rwlock, isc_rwlocktype_write);
        zmgr_resume_xfrs(zmgr, ISC_TRUE);
        RWUNLOCK(&zmgr->rwlock, isc_rwlocktype_write);
}

void
dns_zonemgr_shutdown(dns_zonemgr_t *zmgr) {
        dns_zone_t *zone;

        REQUIRE(DNS_ZONEMGR_VALID(zmgr));

        isc_ratelimiter_shutdown(zmgr->rl);

        if (zmgr->task != NULL)
                isc_task_destroy(&zmgr->task);
        if (zmgr->zonetasks != NULL)
                isc_taskpool_destroy(&zmgr->zonetasks);

        RWLOCK(&zmgr->rwlock, isc_rwlocktype_read);
        for (zone = ISC_LIST_HEAD(zmgr->zones);
             zone != NULL;
             zone = ISC_LIST_NEXT(zone, link))
        {
                LOCK_ZONE(zone);
                forward_cancel(zone);
                UNLOCK_ZONE(zone);
        }
        RWUNLOCK(&zmgr->rwlock, isc_rwlocktype_read);
}

isc_result_t
dns_zonemgr_setsize(dns_zonemgr_t *zmgr, int num_zones) {
        isc_result_t result;
        int ntasks = num_zones / 100;
        isc_taskpool_t *pool = NULL;

        REQUIRE(DNS_ZONEMGR_VALID(zmgr));

        /*
         * For anything fewer than 1000 zones we use 10 tasks in
         * the task pool.  More than that, and we'll scale at one
         * task per 100 zones.
         */
        if (ntasks < 10)
                ntasks = 10;

        /* Create or resize the zone task pool. */
        if (zmgr->zonetasks == NULL)
                result = isc_taskpool_create(zmgr->taskmgr, zmgr->mctx,
                                             ntasks, 2, &pool);
        else
                result = isc_taskpool_expand(&zmgr->zonetasks, ntasks, &pool);

        if (result == ISC_R_SUCCESS)
                zmgr->zonetasks = pool;

        return (result);
}

static void
zonemgr_free(dns_zonemgr_t *zmgr) {
        isc_mem_t *mctx;

        INSIST(zmgr->refs == 0);
        INSIST(ISC_LIST_EMPTY(zmgr->zones));

        zmgr->magic = 0;

        DESTROYLOCK(&zmgr->iolock);
        isc_ratelimiter_detach(&zmgr->rl);

        isc_rwlock_destroy(&zmgr->urlock);
        isc_rwlock_destroy(&zmgr->rwlock);
        mctx = zmgr->mctx;
        isc_mem_put(zmgr->mctx, zmgr, sizeof(*zmgr));
        isc_mem_detach(&mctx);
}

void
dns_zonemgr_settransfersin(dns_zonemgr_t *zmgr, isc_uint32_t value) {
        REQUIRE(DNS_ZONEMGR_VALID(zmgr));

        zmgr->transfersin = value;
}

isc_uint32_t
dns_zonemgr_getttransfersin(dns_zonemgr_t *zmgr) {
        REQUIRE(DNS_ZONEMGR_VALID(zmgr));

        return (zmgr->transfersin);
}

void
dns_zonemgr_settransfersperns(dns_zonemgr_t *zmgr, isc_uint32_t value) {
        REQUIRE(DNS_ZONEMGR_VALID(zmgr));

        zmgr->transfersperns = value;
}

isc_uint32_t
dns_zonemgr_getttransfersperns(dns_zonemgr_t *zmgr) {
        REQUIRE(DNS_ZONEMGR_VALID(zmgr));

        return (zmgr->transfersperns);
}

/*
 * Try to start a new incoming zone transfer to fill a quota
 * slot that was just vacated.
 *
 * Requires:
 *      The zone manager is locked by the caller.
 */
static void
zmgr_resume_xfrs(dns_zonemgr_t *zmgr, isc_boolean_t multi) {
        dns_zone_t *zone;
        dns_zone_t *next;

        for (zone = ISC_LIST_HEAD(zmgr->waiting_for_xfrin);
             zone != NULL;
             zone = next)
        {
                isc_result_t result;
                next = ISC_LIST_NEXT(zone, statelink);
                result = zmgr_start_xfrin_ifquota(zmgr, zone);
                if (result == ISC_R_SUCCESS) {
                        if (multi)
                                continue;
                        /*
                         * We successfully filled the slot.  We're done.
                         */
                        break;
                } else if (result == ISC_R_QUOTA) {
                        /*
                         * Not enough quota.  This is probably the per-server
                         * quota, because we usually get called when a unit of
                         * global quota has just been freed.  Try the next
                         * zone, it may succeed if it uses another master.
                         */
                        continue;
                } else {
                        dns_zone_log(zone, ISC_LOG_DEBUG(1),
                                     "starting zone transfer: %s",
                                     isc_result_totext(result));
                        break;
                }
        }
}

/*
 * Try to start an incoming zone transfer for 'zone', quota permitting.
 *
 * Requires:
 *      The zone manager is locked by the caller.
 *
 * Returns:
 *      ISC_R_SUCCESS   There was enough quota and we attempted to
 *                      start a transfer.  zone_xfrdone() has been or will
 *                      be called.
 *      ISC_R_QUOTA     Not enough quota.
 *      Others          Failure.
 */
static isc_result_t
zmgr_start_xfrin_ifquota(dns_zonemgr_t *zmgr, dns_zone_t *zone) {
        dns_peer_t *peer = NULL;
        isc_netaddr_t masterip;
        isc_uint32_t nxfrsin, nxfrsperns;
        dns_zone_t *x;
        isc_uint32_t maxtransfersin, maxtransfersperns;
        isc_event_t *e;

        /*
         * If we are exiting just pretend we got quota so the zone will
         * be cleaned up in the zone's task context.
         */
        LOCK_ZONE(zone);
        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_EXITING)) {
                UNLOCK_ZONE(zone);
                goto gotquota;
        }

        /*
         * Find any configured information about the server we'd
         * like to transfer this zone from.
         */
        isc_netaddr_fromsockaddr(&masterip, &zone->masteraddr);
        (void)dns_peerlist_peerbyaddr(zone->view->peers, &masterip, &peer);
        UNLOCK_ZONE(zone);

        /*
         * Determine the total maximum number of simultaneous
         * transfers allowed, and the maximum for this specific
         * master.
         */
        maxtransfersin = zmgr->transfersin;
        maxtransfersperns = zmgr->transfersperns;
        if (peer != NULL)
                (void)dns_peer_gettransfers(peer, &maxtransfersperns);

        /*
         * Count the total number of transfers that are in progress,
         * and the number of transfers in progress from this master.
         * We linearly scan a list of all transfers; if this turns
         * out to be too slow, we could hash on the master address.
         */
        nxfrsin = nxfrsperns = 0;
        for (x = ISC_LIST_HEAD(zmgr->xfrin_in_progress);
             x != NULL;
             x = ISC_LIST_NEXT(x, statelink))
        {
                isc_netaddr_t xip;

                LOCK_ZONE(x);
                isc_netaddr_fromsockaddr(&xip, &x->masteraddr);
                UNLOCK_ZONE(x);

                nxfrsin++;
                if (isc_netaddr_equal(&xip, &masterip))
                        nxfrsperns++;
        }

        /* Enforce quota. */
        if (nxfrsin >= maxtransfersin)
                return (ISC_R_QUOTA);

        if (nxfrsperns >= maxtransfersperns)
                return (ISC_R_QUOTA);

 gotquota:
        /*
         * We have sufficient quota.  Move the zone to the "xfrin_in_progress"
         * list and send it an event to let it start the actual transfer in the
         * context of its own task.
         */
        e = isc_event_allocate(zmgr->mctx, zmgr, DNS_EVENT_ZONESTARTXFRIN,
                               got_transfer_quota, zone, sizeof(isc_event_t));
        if (e == NULL)
                return (ISC_R_NOMEMORY);

        LOCK_ZONE(zone);
        INSIST(zone->statelist == &zmgr->waiting_for_xfrin);
        ISC_LIST_UNLINK(zmgr->waiting_for_xfrin, zone, statelink);
        ISC_LIST_APPEND(zmgr->xfrin_in_progress, zone, statelink);
        zone->statelist = &zmgr->xfrin_in_progress;
        isc_task_send(zone->task, &e);
        dns_zone_log(zone, ISC_LOG_INFO, "Transfer started.");
        UNLOCK_ZONE(zone);

        return (ISC_R_SUCCESS);
}

void
dns_zonemgr_setiolimit(dns_zonemgr_t *zmgr, isc_uint32_t iolimit) {

        REQUIRE(DNS_ZONEMGR_VALID(zmgr));
        REQUIRE(iolimit > 0);

        zmgr->iolimit = iolimit;
}

isc_uint32_t
dns_zonemgr_getiolimit(dns_zonemgr_t *zmgr) {

        REQUIRE(DNS_ZONEMGR_VALID(zmgr));

        return (zmgr->iolimit);
}

/*
 * Get permission to request a file handle from the OS.
 * An event will be sent to action when one is available.
 * There are two queues available (high and low), the high
 * queue will be serviced before the low one.
 *
 * zonemgr_putio() must be called after the event is delivered to
 * 'action'.
 */

static isc_result_t
zonemgr_getio(dns_zonemgr_t *zmgr, isc_boolean_t high,
              isc_task_t *task, isc_taskaction_t action, void *arg,
              dns_io_t **iop)
{
        dns_io_t *io;
        isc_boolean_t queue;

        REQUIRE(DNS_ZONEMGR_VALID(zmgr));
        REQUIRE(iop != NULL && *iop == NULL);

        io = isc_mem_get(zmgr->mctx, sizeof(*io));
        if (io == NULL)
                return (ISC_R_NOMEMORY);
        io->event = isc_event_allocate(zmgr->mctx, task, DNS_EVENT_IOREADY,
                                       action, arg, sizeof(*io->event));
        if (io->event == NULL) {
                isc_mem_put(zmgr->mctx, io, sizeof(*io));
                return (ISC_R_NOMEMORY);
        }
        io->zmgr = zmgr;
        io->high = high;
        io->task = NULL;
        isc_task_attach(task, &io->task);
        ISC_LINK_INIT(io, link);
        io->magic = IO_MAGIC;

        LOCK(&zmgr->iolock);
        zmgr->ioactive++;
        queue = ISC_TF(zmgr->ioactive > zmgr->iolimit);
        if (queue) {
                if (io->high)
                        ISC_LIST_APPEND(zmgr->high, io, link);
                else
                        ISC_LIST_APPEND(zmgr->low, io, link);
        }
        UNLOCK(&zmgr->iolock);
        *iop = io;

        if (!queue) {
                isc_task_send(io->task, &io->event);
        }
        return (ISC_R_SUCCESS);
}

static void
zonemgr_putio(dns_io_t **iop) {
        dns_io_t *io;
        dns_io_t *next;
        dns_zonemgr_t *zmgr;

        REQUIRE(iop != NULL);
        io = *iop;
        REQUIRE(DNS_IO_VALID(io));

        *iop = NULL;

        INSIST(!ISC_LINK_LINKED(io, link));
        INSIST(io->event == NULL);

        zmgr = io->zmgr;
        isc_task_detach(&io->task);
        io->magic = 0;
        isc_mem_put(zmgr->mctx, io, sizeof(*io));

        LOCK(&zmgr->iolock);
        INSIST(zmgr->ioactive > 0);
        zmgr->ioactive--;
        next = HEAD(zmgr->high);
        if (next == NULL)
                next = HEAD(zmgr->low);
        if (next != NULL) {
                if (next->high)
                        ISC_LIST_UNLINK(zmgr->high, next, link);
                else
                        ISC_LIST_UNLINK(zmgr->low, next, link);
                INSIST(next->event != NULL);
        }
        UNLOCK(&zmgr->iolock);
        if (next != NULL)
                isc_task_send(next->task, &next->event);
}

static void
zonemgr_cancelio(dns_io_t *io) {
        isc_boolean_t send_event = ISC_FALSE;

        REQUIRE(DNS_IO_VALID(io));

        /*
         * If we are queued to be run then dequeue.
         */
        LOCK(&io->zmgr->iolock);
        if (ISC_LINK_LINKED(io, link)) {
                if (io->high)
                        ISC_LIST_UNLINK(io->zmgr->high, io, link);
                else
                        ISC_LIST_UNLINK(io->zmgr->low, io, link);

                send_event = ISC_TRUE;
                INSIST(io->event != NULL);
        }
        UNLOCK(&io->zmgr->iolock);
        if (send_event) {
                io->event->ev_attributes |= ISC_EVENTATTR_CANCELED;
                isc_task_send(io->task, &io->event);
        }
}

static void
zone_saveunique(dns_zone_t *zone, const char *path, const char *templat) {
        char *buf;
        int buflen;
        isc_result_t result;

        buflen = strlen(path) + strlen(templat) + 2;

        buf = isc_mem_get(zone->mctx, buflen);
        if (buf == NULL)
                return;

        result = isc_file_template(path, templat, buf, buflen);
        if (result != ISC_R_SUCCESS)
                goto cleanup;

        result = isc_file_renameunique(path, buf);
        if (result != ISC_R_SUCCESS)
                goto cleanup;

        dns_zone_log(zone, ISC_LOG_WARNING, "unable to load from '%s'; "
                     "renaming file to '%s' for failure analysis and "
                     "retransferring.", path, buf);

 cleanup:
        isc_mem_put(zone->mctx, buf, buflen);
}

#if 0
/* Hook for ondestroy notification from a database. */

static void
dns_zonemgr_dbdestroyed(isc_task_t *task, isc_event_t *event) {
        dns_db_t *db = event->sender;
        UNUSED(task);

        isc_event_free(&event);

        isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
                      DNS_LOGMODULE_ZONE, ISC_LOG_DEBUG(3),
                      "database (%p) destroyed", (void*) db);
}
#endif

void
dns_zonemgr_setserialqueryrate(dns_zonemgr_t *zmgr, unsigned int value) {
        isc_interval_t interval;
        isc_uint32_t s, ns;
        isc_uint32_t pertic;
        isc_result_t result;

        REQUIRE(DNS_ZONEMGR_VALID(zmgr));

        if (value == 0)
                value = 1;

        if (value == 1) {
                s = 1;
                ns = 0;
                pertic = 1;
        } else if (value <= 10) {
                s = 0;
                ns = 1000000000 / value;
                pertic = 1;
        } else {
                s = 0;
                ns = (1000000000 / value) * 10;
                pertic = 10;
        }

        isc_interval_set(&interval, s, ns);
        result = isc_ratelimiter_setinterval(zmgr->rl, &interval);
        RUNTIME_CHECK(result == ISC_R_SUCCESS);
        isc_ratelimiter_setpertic(zmgr->rl, pertic);

        zmgr->serialqueryrate = value;
}

unsigned int
dns_zonemgr_getserialqueryrate(dns_zonemgr_t *zmgr) {
        REQUIRE(DNS_ZONEMGR_VALID(zmgr));

        return (zmgr->serialqueryrate);
}

isc_boolean_t
dns_zonemgr_unreachable(dns_zonemgr_t *zmgr, isc_sockaddr_t *remote,
                        isc_sockaddr_t *local, isc_time_t *now)
{
        unsigned int i;
        isc_rwlocktype_t locktype;
        isc_result_t result;
        isc_uint32_t seconds = isc_time_seconds(now);

        REQUIRE(DNS_ZONEMGR_VALID(zmgr));

        locktype = isc_rwlocktype_read;
        RWLOCK(&zmgr->urlock, locktype);
        for (i = 0; i < UNREACH_CHACHE_SIZE; i++) {
                if (zmgr->unreachable[i].expire >= seconds &&
                    isc_sockaddr_equal(&zmgr->unreachable[i].remote, remote) &&
                    isc_sockaddr_equal(&zmgr->unreachable[i].local, local)) {
                        result = isc_rwlock_tryupgrade(&zmgr->urlock);
                        if (result == ISC_R_SUCCESS) {
                                locktype = isc_rwlocktype_write;
                                zmgr->unreachable[i].last = seconds;
                        }
                        break;
                }
        }
        RWUNLOCK(&zmgr->urlock, locktype);
        return (ISC_TF(i < UNREACH_CHACHE_SIZE));
}

void
dns_zonemgr_unreachabledel(dns_zonemgr_t *zmgr, isc_sockaddr_t *remote,
                           isc_sockaddr_t *local)
{
        unsigned int i;
        isc_rwlocktype_t locktype;
        isc_result_t result;

        char master[ISC_SOCKADDR_FORMATSIZE];
        char source[ISC_SOCKADDR_FORMATSIZE];

        isc_sockaddr_format(remote, master, sizeof(master));
        isc_sockaddr_format(local, source, sizeof(source));

        REQUIRE(DNS_ZONEMGR_VALID(zmgr));

        locktype = isc_rwlocktype_read;
        RWLOCK(&zmgr->urlock, locktype);
        for (i = 0; i < UNREACH_CHACHE_SIZE; i++) {
                if (isc_sockaddr_equal(&zmgr->unreachable[i].remote, remote) &&
                    isc_sockaddr_equal(&zmgr->unreachable[i].local, local)) {
                        result = isc_rwlock_tryupgrade(&zmgr->urlock);
                        if (result == ISC_R_SUCCESS) {
                                locktype = isc_rwlocktype_write;
                                zmgr->unreachable[i].expire = 0;
                                isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
                                              DNS_LOGMODULE_ZONE, ISC_LOG_INFO,
                                              "master %s (source %s) deleted "
                                              "from unreachable cache",
                                              master, source);
                        }
                        break;
                }
        }
        RWUNLOCK(&zmgr->urlock, locktype);
}

void
dns_zonemgr_unreachableadd(dns_zonemgr_t *zmgr, isc_sockaddr_t *remote,
                           isc_sockaddr_t *local, isc_time_t *now)
{
        isc_uint32_t seconds = isc_time_seconds(now);
        isc_uint32_t last = seconds;
        unsigned int i, slot = UNREACH_CHACHE_SIZE, oldest = 0;

        REQUIRE(DNS_ZONEMGR_VALID(zmgr));

        RWLOCK(&zmgr->urlock, isc_rwlocktype_write);
        for (i = 0; i < UNREACH_CHACHE_SIZE; i++) {
                /* Existing entry? */
                if (isc_sockaddr_equal(&zmgr->unreachable[i].remote, remote) &&
                    isc_sockaddr_equal(&zmgr->unreachable[i].local, local))
                        break;
                /* Empty slot? */
                if (zmgr->unreachable[i].expire < seconds)
                        slot = i;
                /* Least recently used slot? */
                if (zmgr->unreachable[i].last < last) {
                        last = zmgr->unreachable[i].last;
                        oldest = i;
                }
        }
        if (i < UNREACH_CHACHE_SIZE) {
                /*
                 * Found a existing entry.  Update the expire timer and
                 * last usage timestamps.
                 */
                zmgr->unreachable[i].expire = seconds + UNREACH_HOLD_TIME;
                zmgr->unreachable[i].last = seconds;
        } else if (slot != UNREACH_CHACHE_SIZE) {
                /*
                 * Found a empty slot. Add a new entry to the cache.
                 */
                zmgr->unreachable[slot].expire = seconds + UNREACH_HOLD_TIME;
                zmgr->unreachable[slot].last = seconds;
                zmgr->unreachable[slot].remote = *remote;
                zmgr->unreachable[slot].local = *local;
        } else {
                /*
                 * Replace the least recently used entry in the cache.
                 */
                zmgr->unreachable[oldest].expire = seconds + UNREACH_HOLD_TIME;
                zmgr->unreachable[oldest].last = seconds;
                zmgr->unreachable[oldest].remote = *remote;
                zmgr->unreachable[oldest].local = *local;
        }
        RWUNLOCK(&zmgr->urlock, isc_rwlocktype_write);
}

void
dns_zone_forcereload(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        if (zone->type == dns_zone_master)
                return;

        LOCK_ZONE(zone);
        DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_FORCEXFER);
        UNLOCK_ZONE(zone);
        dns_zone_refresh(zone);
}

isc_boolean_t
dns_zone_isforced(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        return (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_FORCEXFER));
}

isc_result_t
dns_zone_setstatistics(dns_zone_t *zone, isc_boolean_t on) {
        /*
         * This function is obsoleted.
         */
        UNUSED(zone);
        UNUSED(on);
        return (ISC_R_NOTIMPLEMENTED);
}

isc_uint64_t *
dns_zone_getstatscounters(dns_zone_t *zone) {
        /*
         * This function is obsoleted.
         */
        UNUSED(zone);
        return (NULL);
}

void
dns_zone_setstats(dns_zone_t *zone, isc_stats_t *stats) {
        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(zone->stats == NULL);

        LOCK_ZONE(zone);
        zone->stats = NULL;
        isc_stats_attach(stats, &zone->stats);
        UNLOCK_ZONE(zone);
}

void
dns_zone_setrequeststats(dns_zone_t *zone, isc_stats_t *stats) {
        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        if (zone->requeststats_on && stats == NULL)
                zone->requeststats_on = ISC_FALSE;
        else if (!zone->requeststats_on && stats != NULL) {
                if (zone->requeststats == NULL) {
                        isc_stats_attach(stats, &zone->requeststats);
                        zone->requeststats_on = ISC_TRUE;
                }
        }
        UNLOCK_ZONE(zone);

        return;
}

isc_stats_t *
dns_zone_getrequeststats(dns_zone_t *zone) {
        /*
         * We don't lock zone for efficiency reason.  This is not catastrophic
         * because requeststats must always be valid when requeststats_on is
         * true.
         * Some counters may be incremented while requeststats_on is becoming
         * false, or some cannot be incremented just after the statistics are
         * installed, but it shouldn't matter much in practice.
         */
        if (zone->requeststats_on)
                return (zone->requeststats);
        else
                return (NULL);
}

void
dns_zone_dialup(dns_zone_t *zone) {

        REQUIRE(DNS_ZONE_VALID(zone));

        zone_debuglog(zone, "dns_zone_dialup", 3,
                      "notify = %d, refresh = %d",
                      DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DIALNOTIFY),
                      DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DIALREFRESH));

        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DIALNOTIFY))
                dns_zone_notify(zone);
        if (zone->type != dns_zone_master &&
            DNS_ZONE_FLAG(zone, DNS_ZONEFLG_DIALREFRESH))
                dns_zone_refresh(zone);
}

void
dns_zone_setdialup(dns_zone_t *zone, dns_dialuptype_t dialup) {
        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        DNS_ZONE_CLRFLAG(zone, DNS_ZONEFLG_DIALNOTIFY |
                         DNS_ZONEFLG_DIALREFRESH |
                         DNS_ZONEFLG_NOREFRESH);
        switch (dialup) {
        case dns_dialuptype_no:
                break;
        case dns_dialuptype_yes:
                DNS_ZONE_SETFLAG(zone,  (DNS_ZONEFLG_DIALNOTIFY |
                                 DNS_ZONEFLG_DIALREFRESH |
                                 DNS_ZONEFLG_NOREFRESH));
                break;
        case dns_dialuptype_notify:
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_DIALNOTIFY);
                break;
        case dns_dialuptype_notifypassive:
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_DIALNOTIFY);
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOREFRESH);
                break;
        case dns_dialuptype_refresh:
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_DIALREFRESH);
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOREFRESH);
                break;
        case dns_dialuptype_passive:
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NOREFRESH);
                break;
        default:
                INSIST(0);
        }
        UNLOCK_ZONE(zone);
}

isc_result_t
dns_zone_setkeydirectory(dns_zone_t *zone, const char *directory) {
        isc_result_t result = ISC_R_SUCCESS;

        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        result = dns_zone_setstring(zone, &zone->keydirectory, directory);
        UNLOCK_ZONE(zone);

        return (result);
}

const char *
dns_zone_getkeydirectory(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->keydirectory);
}

unsigned int
dns_zonemgr_getcount(dns_zonemgr_t *zmgr, int state) {
        dns_zone_t *zone;
        unsigned int count = 0;

        REQUIRE(DNS_ZONEMGR_VALID(zmgr));

        RWLOCK(&zmgr->rwlock, isc_rwlocktype_read);
        switch (state) {
        case DNS_ZONESTATE_XFERRUNNING:
                for (zone = ISC_LIST_HEAD(zmgr->xfrin_in_progress);
                     zone != NULL;
                     zone = ISC_LIST_NEXT(zone, statelink))
                        count++;
                break;
        case DNS_ZONESTATE_XFERDEFERRED:
                for (zone = ISC_LIST_HEAD(zmgr->waiting_for_xfrin);
                     zone != NULL;
                     zone = ISC_LIST_NEXT(zone, statelink))
                        count++;
                break;
        case DNS_ZONESTATE_SOAQUERY:
                for (zone = ISC_LIST_HEAD(zmgr->zones);
                     zone != NULL;
                     zone = ISC_LIST_NEXT(zone, link))
                        if (DNS_ZONE_FLAG(zone, DNS_ZONEFLG_REFRESH))
                                count++;
                break;
        case DNS_ZONESTATE_ANY:
                for (zone = ISC_LIST_HEAD(zmgr->zones);
                     zone != NULL;
                     zone = ISC_LIST_NEXT(zone, link)) {
                        dns_view_t *view = zone->view;
                        if (view != NULL && strcmp(view->name, "_bind") == 0)
                                continue;
                        count++;
                }
                break;
        default:
                INSIST(0);
        }

        RWUNLOCK(&zmgr->rwlock, isc_rwlocktype_read);

        return (count);
}

isc_result_t
dns_zone_checknames(dns_zone_t *zone, dns_name_t *name, dns_rdata_t *rdata) {
        isc_boolean_t ok = ISC_TRUE;
        isc_boolean_t fail = ISC_FALSE;
        char namebuf[DNS_NAME_FORMATSIZE];
        char namebuf2[DNS_NAME_FORMATSIZE];
        char typebuf[DNS_RDATATYPE_FORMATSIZE];
        int level = ISC_LOG_WARNING;
        dns_name_t bad;

        REQUIRE(DNS_ZONE_VALID(zone));

        if (!DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKNAMES))
                return (ISC_R_SUCCESS);

        if (DNS_ZONE_OPTION(zone, DNS_ZONEOPT_CHECKNAMESFAIL)) {
                level = ISC_LOG_ERROR;
                fail = ISC_TRUE;
        }

        ok = dns_rdata_checkowner(name, rdata->rdclass, rdata->type, ISC_TRUE);
        if (!ok) {
                dns_name_format(name, namebuf, sizeof(namebuf));
                dns_rdatatype_format(rdata->type, typebuf, sizeof(typebuf));
                dns_zone_log(zone, level, "%s/%s: %s", namebuf, typebuf,
                             dns_result_totext(DNS_R_BADOWNERNAME));
                if (fail)
                        return (DNS_R_BADOWNERNAME);
        }

        dns_name_init(&bad, NULL);
        ok = dns_rdata_checknames(rdata, name, &bad);
        if (!ok) {
                dns_name_format(name, namebuf, sizeof(namebuf));
                dns_name_format(&bad, namebuf2, sizeof(namebuf2));
                dns_rdatatype_format(rdata->type, typebuf, sizeof(typebuf));
                dns_zone_log(zone, level, "%s/%s: %s: %s ", namebuf, typebuf,
                             namebuf2, dns_result_totext(DNS_R_BADNAME));
                if (fail)
                        return (DNS_R_BADNAME);
        }

        return (ISC_R_SUCCESS);
}

void
dns_zone_setcheckmx(dns_zone_t *zone, dns_checkmxfunc_t checkmx) {
        REQUIRE(DNS_ZONE_VALID(zone));
        zone->checkmx = checkmx;
}

void
dns_zone_setchecksrv(dns_zone_t *zone, dns_checksrvfunc_t checksrv) {
        REQUIRE(DNS_ZONE_VALID(zone));
        zone->checksrv = checksrv;
}

void
dns_zone_setcheckns(dns_zone_t *zone, dns_checknsfunc_t checkns) {
        REQUIRE(DNS_ZONE_VALID(zone));
        zone->checkns = checkns;
}

void
dns_zone_setisself(dns_zone_t *zone, dns_isselffunc_t isself, void *arg) {
        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        zone->isself = isself;
        zone->isselfarg = arg;
        UNLOCK_ZONE(zone);
}

void
dns_zone_setnotifydelay(dns_zone_t *zone, isc_uint32_t delay) {
        REQUIRE(DNS_ZONE_VALID(zone));

        LOCK_ZONE(zone);
        zone->notifydelay = delay;
        UNLOCK_ZONE(zone);
}

isc_uint32_t
dns_zone_getnotifydelay(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));

        return (zone->notifydelay);
}

isc_result_t
dns_zone_signwithkey(dns_zone_t *zone, dns_secalg_t algorithm,
                     isc_uint16_t keyid, isc_boolean_t delete)
{
        isc_result_t result;
        REQUIRE(DNS_ZONE_VALID(zone));

        dns_zone_log(zone, ISC_LOG_NOTICE,
                     "dns_zone_signwithkey(algorithm=%u, keyid=%u)",
                     algorithm, keyid);
        LOCK_ZONE(zone);
        result = zone_signwithkey(zone, algorithm, keyid, delete);
        UNLOCK_ZONE(zone);

        return (result);
}

static const char *hex = "0123456789ABCDEF";

isc_result_t
dns_zone_addnsec3chain(dns_zone_t *zone, dns_rdata_nsec3param_t *nsec3param) {
        isc_result_t result;
        char salt[255*2+1];
        unsigned int i, j;

        REQUIRE(DNS_ZONE_VALID(zone));

        if (nsec3param->salt_length != 0) {
                INSIST((nsec3param->salt_length * 2U) < sizeof(salt));
                for (i = 0, j = 0; i < nsec3param->salt_length; i++) {
                        salt[j++] = hex[(nsec3param->salt[i] >> 4) & 0xf];
                        salt[j++] = hex[nsec3param->salt[i] & 0xf];
                }
                salt[j] = '\0';
        } else
                strcpy(salt, "-");
        dns_zone_log(zone, ISC_LOG_NOTICE,
                     "dns_zone_addnsec3chain(hash=%u, iterations=%u, salt=%s)",
                     nsec3param->hash, nsec3param->iterations,
                     salt);
        LOCK_ZONE(zone);
        result = zone_addnsec3chain(zone, nsec3param);
        UNLOCK_ZONE(zone);

        return (result);
}

void
dns_zone_setnodes(dns_zone_t *zone, isc_uint32_t nodes) {
        REQUIRE(DNS_ZONE_VALID(zone));

        if (nodes == 0)
                nodes = 1;
        zone->nodes = nodes;
}

void
dns_zone_setsignatures(dns_zone_t *zone, isc_uint32_t signatures) {
        REQUIRE(DNS_ZONE_VALID(zone));

        /*
         * We treat signatures as a signed value so explicitly
         * limit its range here.
         */
        if (signatures > ISC_INT32_MAX)
                signatures = ISC_INT32_MAX;
        else if (signatures == 0)
                signatures = 1;
        zone->signatures = signatures;
}

void
dns_zone_setprivatetype(dns_zone_t *zone, dns_rdatatype_t type) {
        REQUIRE(DNS_ZONE_VALID(zone));
        zone->privatetype = type;
}

dns_rdatatype_t
dns_zone_getprivatetype(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));
        return (zone->privatetype);
}

static isc_result_t
zone_signwithkey(dns_zone_t *zone, dns_secalg_t algorithm, isc_uint16_t keyid,
                 isc_boolean_t delete)
{
        dns_signing_t *signing;
        dns_signing_t *current;
        isc_result_t result = ISC_R_SUCCESS;
        isc_time_t now;

        signing = isc_mem_get(zone->mctx, sizeof *signing);
        if (signing == NULL)
                return (ISC_R_NOMEMORY);

        signing->magic = 0;
        signing->db  = NULL;
        signing->dbiterator = NULL;
        signing->algorithm = algorithm;
        signing->keyid = keyid;
        signing->delete = delete;
        signing->done = ISC_FALSE;

        TIME_NOW(&now);

        for (current = ISC_LIST_HEAD(zone->signing);
             current != NULL;
             current = ISC_LIST_NEXT(current, link)) {
                if (current->db == zone->db &&
                    current->algorithm == signing->algorithm &&
                    current->keyid == signing->keyid) {
                        if (current->delete != signing->delete)
                                current->done = ISC_TRUE;
                        else
                                goto cleanup;
                }
        }

        if (zone->db != NULL) {
                dns_db_attach(zone->db, &signing->db);
                result = dns_db_createiterator(signing->db, 0,
                                               &signing->dbiterator);

                if (result == ISC_R_SUCCESS)
                        result = dns_dbiterator_first(signing->dbiterator);
                if (result == ISC_R_SUCCESS) {
                        dns_dbiterator_pause(signing->dbiterator);
                        ISC_LIST_INITANDAPPEND(zone->signing, signing, link);
                        signing = NULL;
                        if (isc_time_isepoch(&zone->signingtime)) {
                                zone->signingtime = now;
                                if (zone->task != NULL)
                                        zone_settimer(zone, &now);
                        }
                }
        } else
                result = ISC_R_NOTFOUND;

 cleanup:
        if (signing != NULL) {
                if (signing->db != NULL)
                        dns_db_detach(&signing->db);
                if (signing->dbiterator != NULL)
                        dns_dbiterator_destroy(&signing->dbiterator);
                isc_mem_put(zone->mctx, signing, sizeof *signing);
        }
        return (result);
}

static void
logmsg(const char *format, ...) {
        va_list args;
        va_start(args, format);
        isc_log_vwrite(dns_lctx, DNS_LOGCATEGORY_GENERAL, DNS_LOGMODULE_ZONE,
                       ISC_LOG_DEBUG(1), format, args);
        va_end(args);
}

static void
clear_keylist(dns_dnsseckeylist_t *list, isc_mem_t *mctx) {
        dns_dnsseckey_t *key;
        while (!ISC_LIST_EMPTY(*list)) {
                key = ISC_LIST_HEAD(*list);
                ISC_LIST_UNLINK(*list, key, link);
                dns_dnsseckey_destroy(mctx, &key);
        }
}

/* Called once; *timep should be set to the current time. */
static isc_result_t
next_keyevent(dst_key_t *key, isc_stdtime_t *timep) {
        isc_result_t result;
        isc_stdtime_t now, then = 0, event;
        int i;

        now = *timep;

        for (i = 0; i <= DST_MAX_TIMES; i++) {
                result = dst_key_gettime(key, i, &event);
                if (result == ISC_R_SUCCESS && event > now &&
                    (then == 0 || event < then))
                        then = event;
        }

        if (then != 0) {
                *timep = then;
                return (ISC_R_SUCCESS);
        }

        return (ISC_R_NOTFOUND);
}

static isc_result_t
rr_exists(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
          const dns_rdata_t *rdata, isc_boolean_t *flag)
{
        dns_rdataset_t rdataset;
        dns_dbnode_t *node = NULL;
        isc_result_t result;

        dns_rdataset_init(&rdataset);
        if (rdata->type == dns_rdatatype_nsec3)
                CHECK(dns_db_findnsec3node(db, name, ISC_FALSE, &node));
        else
                CHECK(dns_db_findnode(db, name, ISC_FALSE, &node));
        result = dns_db_findrdataset(db, node, ver, rdata->type, 0,
                                     (isc_stdtime_t) 0, &rdataset, NULL);
        if (result == ISC_R_NOTFOUND) {
                *flag = ISC_FALSE;
                result = ISC_R_SUCCESS;
                goto failure;
        }

        for (result = dns_rdataset_first(&rdataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(&rdataset)) {
                dns_rdata_t myrdata = DNS_RDATA_INIT;
                dns_rdataset_current(&rdataset, &myrdata);
                if (!dns_rdata_compare(&myrdata, rdata))
                        break;
        }
        dns_rdataset_disassociate(&rdataset);
        if (result == ISC_R_SUCCESS) {
                *flag = ISC_TRUE;
        } else if (result == ISC_R_NOMORE) {
                *flag = ISC_FALSE;
                result = ISC_R_SUCCESS;
        }

 failure:
        if (node != NULL)
                dns_db_detachnode(db, &node);
        return (result);
}

/*
 * Add records to signal the state of signing or of key removal.
 */
static isc_result_t
add_signing_records(dns_db_t *db, dns_rdatatype_t privatetype,
                    dns_dbversion_t *ver, dns_diff_t *diff,
                    isc_boolean_t sign_all)
{
        dns_difftuple_t *tuple, *newtuple = NULL;
        dns_rdata_dnskey_t dnskey;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        isc_boolean_t flag;
        isc_region_t r;
        isc_result_t result = ISC_R_SUCCESS;
        isc_uint16_t keyid;
        unsigned char buf[5];
        dns_name_t *name = dns_db_origin(db);

        for (tuple = ISC_LIST_HEAD(diff->tuples);
             tuple != NULL;
             tuple = ISC_LIST_NEXT(tuple, link)) {
                if (tuple->rdata.type != dns_rdatatype_dnskey)
                        continue;

                result = dns_rdata_tostruct(&tuple->rdata, &dnskey, NULL);
                RUNTIME_CHECK(result == ISC_R_SUCCESS);
                if ((dnskey.flags &
                     (DNS_KEYFLAG_OWNERMASK|DNS_KEYTYPE_NOAUTH))
                         != DNS_KEYOWNER_ZONE)
                        continue;

                dns_rdata_toregion(&tuple->rdata, &r);

                keyid = dst_region_computeid(&r, dnskey.algorithm);

                buf[0] = dnskey.algorithm;
                buf[1] = (keyid & 0xff00) >> 8;
                buf[2] = (keyid & 0xff);
                buf[3] = (tuple->op == DNS_DIFFOP_ADD) ? 0 : 1;
                buf[4] = 0;
                rdata.data = buf;
                rdata.length = sizeof(buf);
                rdata.type = privatetype;
                rdata.rdclass = tuple->rdata.rdclass;

                if (sign_all || tuple->op == DNS_DIFFOP_DEL) {
                        CHECK(rr_exists(db, ver, name, &rdata, &flag));
                        if (flag)
                                continue;
                        CHECK(dns_difftuple_create(diff->mctx, DNS_DIFFOP_ADD,
                                                   name, 0, &rdata, &newtuple));
                        CHECK(do_one_tuple(&newtuple, db, ver, diff));
                        INSIST(newtuple == NULL);
                }

                /*
                 * Remove any record which says this operation has already
                 * completed.
                 */
                buf[4] = 1;
                CHECK(rr_exists(db, ver, name, &rdata, &flag));
                if (flag) {
                        CHECK(dns_difftuple_create(diff->mctx, DNS_DIFFOP_DEL,
                                                   name, 0, &rdata, &newtuple));
                        CHECK(do_one_tuple(&newtuple, db, ver, diff));
                        INSIST(newtuple == NULL);
                }
        }
 failure:
        return (result);
}

static isc_result_t
sign_apex(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *ver,
          dns_diff_t *diff, dns_diff_t *sig_diff)
{
        isc_result_t result;
        isc_stdtime_t now, inception, soaexpire;
        isc_boolean_t check_ksk, keyset_kskonly;
        dst_key_t *zone_keys[DNS_MAXZONEKEYS];
        unsigned int nkeys = 0, i;
        dns_difftuple_t *tuple;

        result = find_zone_keys(zone, db, ver, zone->mctx, DNS_MAXZONEKEYS,
                                zone_keys, &nkeys);
        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "sign_apex:find_zone_keys -> %s",
                             dns_result_totext(result));
                return (result);
        }

        isc_stdtime_get(&now);
        inception = now - 3600; /* Allow for clock skew. */
        soaexpire = now + dns_zone_getsigvalidityinterval(zone);

        check_ksk = DNS_ZONE_OPTION(zone, DNS_ZONEOPT_UPDATECHECKKSK);
        keyset_kskonly = DNS_ZONE_OPTION(zone, DNS_ZONEOPT_DNSKEYKSKONLY);

        /*
         * See if update_sigs will update DNSKEY signature and if not
         * cause them to sign so that so that newly activated keys
         * are used.
         */
        for (tuple = ISC_LIST_HEAD(diff->tuples);
             tuple != NULL;
             tuple = ISC_LIST_NEXT(tuple, link)) {
                if (tuple->rdata.type == dns_rdatatype_dnskey &&
                    dns_name_equal(&tuple->name, &zone->origin))
                        break;
        }

        if (tuple == NULL) {
                result = del_sigs(zone, db, ver, &zone->origin,
                                  dns_rdatatype_dnskey, sig_diff,
                                  zone_keys, nkeys, now, ISC_FALSE);
                if (result != ISC_R_SUCCESS) {
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "sign_apex:del_sigs -> %s",
                                     dns_result_totext(result));
                        goto failure;
                }
                result = add_sigs(db, ver, &zone->origin, dns_rdatatype_dnskey,
                                  sig_diff, zone_keys, nkeys, zone->mctx,
                                  inception, soaexpire, check_ksk,
                                  keyset_kskonly);
                if (result != ISC_R_SUCCESS) {
                        dns_zone_log(zone, ISC_LOG_ERROR,
                                     "sign_apex:add_sigs -> %s",
                                     dns_result_totext(result));
                        goto failure;
                }
        }

        result = update_sigs(diff, db, ver, zone_keys, nkeys, zone,
                             inception, soaexpire, now, check_ksk,
                             keyset_kskonly, sig_diff);

        if (result != ISC_R_SUCCESS) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                             "sign_apex:update_sigs -> %s",
                             dns_result_totext(result));
                goto failure;
        }

 failure:
        for (i = 0; i < nkeys; i++)
                dst_key_free(&zone_keys[i]);
        return (result);
}

/*
 * Prevent the zone entering a inconsistent state where
 * NSEC only DNSKEYs are present with NSEC3 chains.
 * See update.c:check_dnssec()
 */
static isc_boolean_t
dnskey_sane(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *ver,
            dns_diff_t *diff)
{
        isc_result_t result;
        dns_difftuple_t *tuple;
        isc_boolean_t nseconly = ISC_FALSE, nsec3 = ISC_FALSE;
        dns_rdatatype_t privatetype = dns_zone_getprivatetype(zone);

        /* Scan the tuples for an NSEC-only DNSKEY */
        for (tuple = ISC_LIST_HEAD(diff->tuples);
             tuple != NULL;
             tuple = ISC_LIST_NEXT(tuple, link)) {
                isc_uint8_t alg;
                if (tuple->rdata.type != dns_rdatatype_dnskey ||
                    tuple->op != DNS_DIFFOP_ADD)
                        continue;

                alg = tuple->rdata.data[3];
                if (alg == DST_ALG_RSAMD5 || alg == DST_ALG_RSASHA1 ||
                    alg == DST_ALG_DSA || alg == DST_ALG_ECC) {
                        nseconly = ISC_TRUE;
                        break;
                }
        }

        /* Check existing DB for NSEC-only DNSKEY */
        if (!nseconly)
                CHECK(dns_nsec_nseconly(db, ver, &nseconly));

        /* Check existing DB for NSEC3 */
        if (!nsec3)
                CHECK(dns_nsec3_activex(db, ver, ISC_FALSE,
                                        privatetype, &nsec3));

        /* Refuse to allow NSEC3 with NSEC-only keys */
        if (nseconly && nsec3) {
                dns_zone_log(zone, ISC_LOG_ERROR,
                           "NSEC only DNSKEYs and NSEC3 chains not allowed");
                goto failure;
        }

        return (ISC_TRUE);

 failure:
        return (ISC_FALSE);
}

static isc_result_t
clean_nsec3param(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *ver,
                 dns_diff_t *diff)
{
        isc_result_t result;
        dns_dbnode_t *node = NULL;
        dns_rdataset_t rdataset;

        dns_rdataset_init(&rdataset);
        CHECK(dns_db_getoriginnode(db, &node));

        result = dns_db_findrdataset(db, node, ver, dns_rdatatype_dnskey,
                                     dns_rdatatype_none, 0, &rdataset, NULL);
        if (dns_rdataset_isassociated(&rdataset))
                dns_rdataset_disassociate(&rdataset);
        if (result != ISC_R_NOTFOUND)
                goto failure;

        result = dns_nsec3param_deletechains(db, ver, zone, diff);

 failure:
        if (node != NULL)
                dns_db_detachnode(db, &node);
        return (result);
}

/*
 * Given an RRSIG rdataset and an algorithm, determine whether there
 * are any signatures using that algorithm.
 */
static isc_boolean_t
signed_with_alg(dns_rdataset_t *rdataset, dns_secalg_t alg) {
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_rdata_rrsig_t rrsig;
        isc_result_t result;

        REQUIRE(rdataset == NULL || rdataset->type == dns_rdatatype_rrsig);
        if (rdataset == NULL || !dns_rdataset_isassociated(rdataset)) {
                return (ISC_FALSE);
        }

        for (result = dns_rdataset_first(rdataset);
             result == ISC_R_SUCCESS;
             result = dns_rdataset_next(rdataset))
        {
                dns_rdataset_current(rdataset, &rdata);
                result = dns_rdata_tostruct(&rdata, &rrsig, NULL);
                RUNTIME_CHECK(result == ISC_R_SUCCESS);
                dns_rdata_reset(&rdata);
                if (rrsig.algorithm == alg)
                        return (ISC_TRUE);
        }

        return (ISC_FALSE);
}

static isc_result_t
add_chains(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *ver,
           dns_diff_t *diff)
{
        dns_name_t *origin;
        isc_boolean_t build_nsec3;
        isc_result_t result;

        origin = dns_db_origin(db);
        CHECK(dns_private_chains(db, ver, zone->privatetype, NULL,
                                 &build_nsec3));
        if (build_nsec3)
                CHECK(dns_nsec3_addnsec3sx(db, ver, origin, zone->minimum,
                                           ISC_FALSE, zone->privatetype, diff));
        CHECK(updatesecure(db, ver, origin, zone->minimum, ISC_TRUE, diff));

 failure:
        return (result);
}

static void
zone_rekey(dns_zone_t *zone) {
        isc_result_t result;
        dns_db_t *db = NULL;
        dns_dbnode_t *node = NULL;
        dns_dbversion_t *ver = NULL;
        dns_rdataset_t soaset, soasigs, keyset, keysigs;
        dns_dnsseckeylist_t dnskeys, keys, rmkeys;
        dns_dnsseckey_t *key;
        dns_diff_t diff, sig_diff;
        isc_boolean_t commit = ISC_FALSE, newactive = ISC_FALSE;
        isc_boolean_t newalg = ISC_FALSE;
        isc_boolean_t fullsign;
        dns_ttl_t ttl = 3600;
        const char *dir;
        isc_mem_t *mctx;
        isc_stdtime_t now;
        isc_time_t timenow;
        isc_interval_t ival;
        char timebuf[80];

        REQUIRE(DNS_ZONE_VALID(zone));

        ISC_LIST_INIT(dnskeys);
        ISC_LIST_INIT(keys);
        ISC_LIST_INIT(rmkeys);
        dns_rdataset_init(&soaset);
        dns_rdataset_init(&soasigs);
        dns_rdataset_init(&keyset);
        dns_rdataset_init(&keysigs);
        dir = dns_zone_getkeydirectory(zone);
        mctx = zone->mctx;
        dns_diff_init(mctx, &diff);
        dns_diff_init(mctx, &sig_diff);
        sig_diff.resign = zone->sigresigninginterval;

        CHECK(dns_zone_getdb(zone, &db));
        CHECK(dns_db_newversion(db, &ver));
        CHECK(dns_db_getoriginnode(db, &node));

        TIME_NOW(&timenow);
        now = isc_time_seconds(&timenow);

        dns_zone_log(zone, ISC_LOG_INFO, "reconfiguring zone keys");

        /* Get the SOA record's TTL */
        CHECK(dns_db_findrdataset(db, node, ver, dns_rdatatype_soa,
                                  dns_rdatatype_none, 0, &soaset, &soasigs));
        ttl = soaset.ttl;
        dns_rdataset_disassociate(&soaset);

        /* Get the DNSKEY rdataset */
        result = dns_db_findrdataset(db, node, ver, dns_rdatatype_dnskey,
                                     dns_rdatatype_none, 0, &keyset, &keysigs);
        if (result == ISC_R_SUCCESS) {
                ttl = keyset.ttl;
                result = dns_dnssec_keylistfromrdataset(&zone->origin, dir,
                                                        mctx, &keyset,
                                                        &keysigs, &soasigs,
                                                        ISC_FALSE, ISC_FALSE,
                                                        &dnskeys);
                /* Can't get keys for some reason; try again later. */
                if (result != ISC_R_SUCCESS)
                        goto trylater;
        } else if (result != ISC_R_NOTFOUND)
                goto failure;

        /*
         * True when called from "rndc sign".  Indicates the zone should be
         * fully signed now.
         */
        fullsign = ISC_TF(DNS_ZONEKEY_OPTION(zone, DNS_ZONEKEY_FULLSIGN) != 0);

        result = dns_dnssec_findmatchingkeys(&zone->origin, dir, mctx, &keys);
        if (result == ISC_R_SUCCESS) {
                isc_boolean_t check_ksk;
                check_ksk = DNS_ZONE_OPTION(zone, DNS_ZONEOPT_UPDATECHECKKSK);

                result = dns_dnssec_updatekeys(&dnskeys, &keys, &rmkeys,
                                               &zone->origin, ttl, &diff,
                                               ISC_TF(!check_ksk),
                                               mctx, logmsg);

                /* Keys couldn't be updated for some reason;
                 * try again later. */
                if (result != ISC_R_SUCCESS) {
                        dns_zone_log(zone, ISC_LOG_ERROR, "zone_rekey:"
                                     "couldn't update zone keys: %s",
                                     isc_result_totext(result));
                        goto trylater;
                }

                /*
                 * See if any pre-existing keys have newly become active;
                 * also, see if any new key is for a new algorithm, as in that
                 * event, we need to sign the zone fully.  (If there's a new
                 * key, but it's for an already-existing algorithm, then
                 * the zone signing can be handled incrementally.)
                 */
                for (key = ISC_LIST_HEAD(dnskeys);
                     key != NULL;
                     key = ISC_LIST_NEXT(key, link)) {
                        if (!key->first_sign)
                                continue;

                        newactive = ISC_TRUE;

                        if (!dns_rdataset_isassociated(&keysigs)) {
                                newalg = ISC_TRUE;
                                break;
                        }

                        if (signed_with_alg(&keysigs, dst_key_alg(key->key))) {
                                /*
                                 * This isn't a new algorithm; clear
                                 * first_sign so we won't sign the
                                 * whole zone with this key later
                                 */
                                key->first_sign = ISC_FALSE;
                        } else {
                                newalg = ISC_TRUE;
                                break;
                        }
                }

                if ((newactive || fullsign || !ISC_LIST_EMPTY(diff.tuples)) &&
                    dnskey_sane(zone, db, ver, &diff)) {
                        CHECK(dns_diff_apply(&diff, db, ver));
                        CHECK(clean_nsec3param(zone, db, ver, &diff));
                        CHECK(add_signing_records(db, zone->privatetype,
                                                  ver, &diff,
                                                  ISC_TF(newalg || fullsign)));
                        CHECK(increment_soa_serial(db, ver, &diff, mctx));
                        CHECK(add_chains(zone, db, ver, &diff));
                        CHECK(sign_apex(zone, db, ver, &diff, &sig_diff));
                        CHECK(zone_journal(zone, &sig_diff, "zone_rekey"));
                        commit = ISC_TRUE;
                }
        }

        dns_db_closeversion(db, &ver, commit);

        if (commit) {
                dns_difftuple_t *tuple;

                LOCK_ZONE(zone);
                DNS_ZONE_SETFLAG(zone, DNS_ZONEFLG_NEEDNOTIFY);

                zone_needdump(zone, DNS_DUMP_DELAY);

                zone_settimer(zone, &timenow);

                /* Remove any signatures from removed keys.  */
                if (!ISC_LIST_EMPTY(rmkeys)) {
                        for (key = ISC_LIST_HEAD(rmkeys);
                             key != NULL;
                             key = ISC_LIST_NEXT(key, link)) {
                                result = zone_signwithkey(zone,
                                                          dst_key_alg(key->key),
                                                          dst_key_id(key->key),
                                                          ISC_TRUE);
                                if (result != ISC_R_SUCCESS) {
                                        dns_zone_log(zone, ISC_LOG_ERROR,
                                             "zone_signwithkey failed: %s",
                                             dns_result_totext(result));
                                }
                        }
                }

                if (fullsign) {
                        /*
                         * "rndc sign" was called, so we now sign the zone
                         * with all active keys, whether they're new or not.
                         */
                        for (key = ISC_LIST_HEAD(dnskeys);
                             key != NULL;
                             key = ISC_LIST_NEXT(key, link)) {
                                if (!key->force_sign && !key->hint_sign)
                                        continue;

                                result = zone_signwithkey(zone,
                                                          dst_key_alg(key->key),
                                                          dst_key_id(key->key),
                                                          ISC_FALSE);
                                if (result != ISC_R_SUCCESS) {
                                        dns_zone_log(zone, ISC_LOG_ERROR,
                                             "zone_signwithkey failed: %s",
                                             dns_result_totext(result));
                                }
                        }
                } else if (newalg) {
                        /*
                         * We haven't been told to sign fully, but a new
                         * algorithm was added to the DNSKEY.  We sign
                         * the full zone, but only with newly active
                         * keys.
                         */
                        for (key = ISC_LIST_HEAD(dnskeys);
                             key != NULL;
                             key = ISC_LIST_NEXT(key, link)) {
                                if (!key->first_sign)
                                        continue;

                                result = zone_signwithkey(zone,
                                                          dst_key_alg(key->key),
                                                          dst_key_id(key->key),
                                                          ISC_FALSE);
                                if (result != ISC_R_SUCCESS) {
                                        dns_zone_log(zone, ISC_LOG_ERROR,
                                             "zone_signwithkey failed: %s",
                                             dns_result_totext(result));
                                }
                        }
                }

                /*
                 * Clear fullsign flag, if it was set, so we don't do
                 * another full signing next time
                 */
                zone->keyopts &= ~DNS_ZONEKEY_FULLSIGN;

                /*
                 * Cause the zone to add/delete NSEC3 chains for the
                 * deferred NSEC3PARAM changes.
                 */
                for (tuple = ISC_LIST_HEAD(sig_diff.tuples);
                     tuple != NULL;
                     tuple = ISC_LIST_NEXT(tuple, link)) {
                        unsigned char buf[DNS_NSEC3PARAM_BUFFERSIZE];
                        dns_rdata_t rdata = DNS_RDATA_INIT;
                        dns_rdata_nsec3param_t nsec3param;

                        if (tuple->rdata.type != zone->privatetype ||
                            tuple->op != DNS_DIFFOP_ADD)
                                continue;

                        if (!dns_nsec3param_fromprivate(&tuple->rdata, &rdata,
                                                        buf, sizeof(buf)))
                                continue;
                        result = dns_rdata_tostruct(&rdata, &nsec3param, NULL);
                        RUNTIME_CHECK(result == ISC_R_SUCCESS);
                        if (nsec3param.flags == 0)
                                continue;

                        result = zone_addnsec3chain(zone, &nsec3param);
                        if (result != ISC_R_SUCCESS) {
                                dns_zone_log(zone, ISC_LOG_ERROR,
                                             "zone_addnsec3chain failed: %s",
                                             dns_result_totext(result));
                        }
                }

                /*
                 * Schedule the next resigning event
                 */
                set_resigntime(zone);
                UNLOCK_ZONE(zone);
        }

        isc_time_settoepoch(&zone->refreshkeytime);

        /*
         * If we're doing key maintenance, set the key refresh timer to
         * the next scheduled key event or to one hour in the future,
         * whichever is sooner.
         */
        if (DNS_ZONEKEY_OPTION(zone, DNS_ZONEKEY_MAINTAIN)) {
                isc_time_t timethen;
                isc_stdtime_t then;

                LOCK_ZONE(zone);
                DNS_ZONE_TIME_ADD(&timenow, HOUR, &timethen);
                zone->refreshkeytime = timethen;
                UNLOCK_ZONE(zone);

                for (key = ISC_LIST_HEAD(dnskeys);
                     key != NULL;
                     key = ISC_LIST_NEXT(key, link)) {
                        then = now;
                        result = next_keyevent(key->key, &then);
                        if (result != ISC_R_SUCCESS)
                                continue;

                        DNS_ZONE_TIME_ADD(&timenow, then - now, &timethen);
                        LOCK_ZONE(zone);
                        if (isc_time_compare(&timethen,
                                             &zone->refreshkeytime) < 0) {
                                zone->refreshkeytime = timethen;
                        }
                        UNLOCK_ZONE(zone);
                }

                zone_settimer(zone, &timenow);

                isc_time_formattimestamp(&zone->refreshkeytime, timebuf, 80);
                dns_zone_log(zone, ISC_LOG_INFO, "next key event: %s", timebuf);
        }

 failure:
        dns_diff_clear(&diff);
        dns_diff_clear(&sig_diff);

        clear_keylist(&dnskeys, mctx);
        clear_keylist(&keys, mctx);
        clear_keylist(&rmkeys, mctx);

        if (ver != NULL)
                dns_db_closeversion(db, &ver, ISC_FALSE);
        if (dns_rdataset_isassociated(&keyset))
                dns_rdataset_disassociate(&keyset);
        if (dns_rdataset_isassociated(&keysigs))
                dns_rdataset_disassociate(&keysigs);
        if (dns_rdataset_isassociated(&soasigs))
                dns_rdataset_disassociate(&soasigs);
        if (node != NULL)
                dns_db_detachnode(db, &node);
        if (db != NULL)
                dns_db_detach(&db);
        return;

 trylater:
        isc_interval_set(&ival, HOUR, 0);
        isc_time_nowplusinterval(&zone->refreshkeytime, &ival);
        goto failure;
}

void
dns_zone_rekey(dns_zone_t *zone, isc_boolean_t fullsign) {
        isc_time_t now;

        if (zone->type == dns_zone_master && zone->task != NULL) {
                LOCK_ZONE(zone);

                if (fullsign)
                        zone->keyopts |= DNS_ZONEKEY_FULLSIGN;

                TIME_NOW(&now);
                zone->refreshkeytime = now;
                zone_settimer(zone, &now);

                UNLOCK_ZONE(zone);
        }
}

isc_result_t
dns_zone_nscheck(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *version,
                 unsigned int *errors)
{
        isc_result_t result;
        dns_dbnode_t *node = NULL;

        REQUIRE(DNS_ZONE_VALID(zone));
        REQUIRE(errors != NULL);

        result = dns_db_getoriginnode(db, &node);
        if (result != ISC_R_SUCCESS)
                return (result);
        result = zone_count_ns_rr(zone, db, node, version, NULL, errors,
                                  ISC_FALSE);
        dns_db_detachnode(db, &node);
        return (result);
}

void
dns_zone_setadded(dns_zone_t *zone, isc_boolean_t added) {
        REQUIRE(DNS_ZONE_VALID(zone));
        LOCK_ZONE(zone);
        zone->added = added;
        UNLOCK_ZONE(zone);
}

isc_boolean_t
dns_zone_getadded(dns_zone_t *zone) {
        REQUIRE(DNS_ZONE_VALID(zone));
        return (zone->added);
}

isc_result_t
dns_zone_dlzpostload(dns_zone_t *zone, dns_db_t *db)
{
        isc_time_t loadtime;
        isc_result_t result;
        TIME_NOW(&loadtime);

        LOCK_ZONE(zone);
        result = zone_postload(zone, db, loadtime, ISC_R_SUCCESS);
        UNLOCK_ZONE(zone);
        return result;
}