contrib/bind9/lib/dns/adb.c

   1 /*
   2  * Copyright (C) 2004-2008  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 1999-2003  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and/or distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  15  * PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 /* $Id: adb.c,v 1.215.18.24 2008/10/17 03:35:14 marka Exp $ */
  19
  20 /*! \file
  21  *
  22  * \note
  23  * In finds, if task == NULL, no events will be generated, and no events
  24  * have been sent.  If task != NULL but taskaction == NULL, an event has been
  25  * posted but not yet freed.  If neither are NULL, no event was posted.
  26  *
  27  */
  28
  29 /*%
  30  * After we have cleaned all buckets, dump the database contents.
  31  */
  32 #if 0
  33 #define DUMP_ADB_AFTER_CLEANING
  34 #endif
  35
  36 #include <config.h>
  37
  38 #include <limits.h>
  39
  40 #include <isc/mutexblock.h>
  41 #include <isc/netaddr.h>
  42 #include <isc/random.h>
  43 #include <isc/string.h>         /* Required for HP/UX (and others?) */
  44 #include <isc/task.h>
  45 #include <isc/timer.h>
  46 #include <isc/util.h>
  47
  48 #include <dns/adb.h>
  49 #include <dns/db.h>
  50 #include <dns/events.h>
  51 #include <dns/log.h>
  52 #include <dns/rdata.h>
  53 #include <dns/rdataset.h>
  54 #include <dns/rdatastruct.h>
  55 #include <dns/rdatatype.h>
  56 #include <dns/resolver.h>
  57 #include <dns/result.h>
  58
  59 #define DNS_ADB_MAGIC             ISC_MAGIC('D', 'a', 'd', 'b')
  60 #define DNS_ADB_VALID(x)          ISC_MAGIC_VALID(x, DNS_ADB_MAGIC)
  61 #define DNS_ADBNAME_MAGIC         ISC_MAGIC('a', 'd', 'b', 'N')
  62 #define DNS_ADBNAME_VALID(x)      ISC_MAGIC_VALID(x, DNS_ADBNAME_MAGIC)
  63 #define DNS_ADBNAMEHOOK_MAGIC     ISC_MAGIC('a', 'd', 'N', 'H')
  64 #define DNS_ADBNAMEHOOK_VALID(x)  ISC_MAGIC_VALID(x, DNS_ADBNAMEHOOK_MAGIC)
  65 #define DNS_ADBLAMEINFO_MAGIC     ISC_MAGIC('a', 'd', 'b', 'Z')
  66 #define DNS_ADBLAMEINFO_VALID(x)  ISC_MAGIC_VALID(x, DNS_ADBLAMEINFO_MAGIC)
  67 #define DNS_ADBENTRY_MAGIC        ISC_MAGIC('a', 'd', 'b', 'E')
  68 #define DNS_ADBENTRY_VALID(x)     ISC_MAGIC_VALID(x, DNS_ADBENTRY_MAGIC)
  69 #define DNS_ADBFETCH_MAGIC        ISC_MAGIC('a', 'd', 'F', '4')
  70 #define DNS_ADBFETCH_VALID(x)     ISC_MAGIC_VALID(x, DNS_ADBFETCH_MAGIC)
  71 #define DNS_ADBFETCH6_MAGIC       ISC_MAGIC('a', 'd', 'F', '6')
  72 #define DNS_ADBFETCH6_VALID(x)    ISC_MAGIC_VALID(x, DNS_ADBFETCH6_MAGIC)
  73
  74 /*!
  75  * The number of buckets needs to be a prime (for good hashing).
  76  *
  77  * XXXRTH  How many buckets do we need?
  78  */
  79 #define NBUCKETS               1009     /*%< how many buckets for names/addrs */
  80
  81 /*!
  82  * For type 3 negative cache entries, we will remember that the address is
  83  * broken for this long.  XXXMLG This is also used for actual addresses, too.
  84  * The intent is to keep us from constantly asking about A/AAAA records
  85  * if the zone has extremely low TTLs.
  86  */
  87 #define ADB_CACHE_MINIMUM       10      /*%< seconds */
  88 #define ADB_CACHE_MAXIMUM       86400   /*%< seconds (86400 = 24 hours) */
  89 #define ADB_ENTRY_WINDOW        1800    /*%< seconds */
  90
  91 /*%
  92  * Wake up every CLEAN_SECONDS and clean CLEAN_BUCKETS buckets, so that all
  93  * buckets are cleaned in CLEAN_PERIOD seconds.
  94  */
  95 #define CLEAN_PERIOD            3600
  96 /*% See #CLEAN_PERIOD */
  97 #define CLEAN_SECONDS           30
  98 /*% See #CLEAN_PERIOD */
  99 #define CLEAN_BUCKETS           ((NBUCKETS * CLEAN_SECONDS) / CLEAN_PERIOD)
 100
 101 #define FREE_ITEMS              64      /*%< free count for memory pools */
 102 #define FILL_COUNT              16      /*%< fill count for memory pools */
 103
 104 #define DNS_ADB_INVALIDBUCKET (-1)      /*%< invalid bucket address */
 105
 106 #define DNS_ADB_MINADBSIZE      (1024*1024)     /*%< 1 Megabyte */
 107
 108 typedef ISC_LIST(dns_adbname_t) dns_adbnamelist_t;
 109 typedef struct dns_adbnamehook dns_adbnamehook_t;
 110 typedef ISC_LIST(dns_adbnamehook_t) dns_adbnamehooklist_t;
 111 typedef struct dns_adblameinfo dns_adblameinfo_t;
 112 typedef ISC_LIST(dns_adbentry_t) dns_adbentrylist_t;
 113 typedef struct dns_adbfetch dns_adbfetch_t;
 114 typedef struct dns_adbfetch6 dns_adbfetch6_t;
 115
 116 /*% dns adb structure */
 117 struct dns_adb {
 118         unsigned int                    magic;
 119
 120         isc_mutex_t                     lock;
 121         isc_mutex_t                     reflock; /*%< Covers irefcnt, erefcnt */
 122         isc_mutex_t                     overmemlock; /*%< Covers overmem */
 123         isc_mem_t                      *mctx;
 124         dns_view_t                     *view;
 125         isc_timermgr_t                 *timermgr;
 126         isc_timer_t                    *timer;
 127         isc_taskmgr_t                  *taskmgr;
 128         isc_task_t                     *task;
 129         isc_boolean_t                   overmem;
 130
 131         isc_interval_t                  tick_interval;
 132         int                             next_cleanbucket;
 133
 134         unsigned int                    irefcnt;
 135         unsigned int                    erefcnt;
 136
 137         isc_mutex_t                     mplock;
 138         isc_mempool_t                  *nmp;    /*%< dns_adbname_t */
 139         isc_mempool_t                  *nhmp;   /*%< dns_adbnamehook_t */
 140         isc_mempool_t                  *limp;   /*%< dns_adblameinfo_t */
 141         isc_mempool_t                  *emp;    /*%< dns_adbentry_t */
 142         isc_mempool_t                  *ahmp;   /*%< dns_adbfind_t */
 143         isc_mempool_t                  *aimp;   /*%< dns_adbaddrinfo_t */
 144         isc_mempool_t                  *afmp;   /*%< dns_adbfetch_t */
 145
 146         /*!
 147          * Bucketized locks and lists for names.
 148          *
 149          * XXXRTH  Have a per-bucket structure that contains all of these?
 150          */
 151         dns_adbnamelist_t               names[NBUCKETS];
 152         /*% See dns_adbnamelist_t */
 153         isc_mutex_t                     namelocks[NBUCKETS];
 154         /*% See dns_adbnamelist_t */
 155         isc_boolean_t                   name_sd[NBUCKETS];
 156         /*% See dns_adbnamelist_t */
 157         unsigned int                    name_refcnt[NBUCKETS];
 158
 159         /*!
 160          * Bucketized locks for entries.
 161          *
 162          * XXXRTH  Have a per-bucket structure that contains all of these?
 163          */
 164         dns_adbentrylist_t              entries[NBUCKETS];
 165         isc_mutex_t                     entrylocks[NBUCKETS];
 166         isc_boolean_t                   entry_sd[NBUCKETS]; /*%< shutting down */
 167         unsigned int                    entry_refcnt[NBUCKETS];
 168
 169         isc_event_t                     cevent;
 170         isc_boolean_t                   cevent_sent;
 171         isc_boolean_t                   shutting_down;
 172         isc_eventlist_t                 whenshutdown;
 173 };
 174
 175 /*
 176  * XXXMLG  Document these structures.
 177  */
 178
 179 /*% dns_adbname structure */
 180 struct dns_adbname {
 181         unsigned int                    magic;
 182         dns_name_t                      name;
 183         dns_adb_t                      *adb;
 184         unsigned int                    partial_result;
 185         unsigned int                    flags;
 186         int                             lock_bucket;
 187         dns_name_t                      target;
 188         isc_stdtime_t                   expire_target;
 189         isc_stdtime_t                   expire_v4;
 190         isc_stdtime_t                   expire_v6;
 191         unsigned int                    chains;
 192         dns_adbnamehooklist_t           v4;
 193         dns_adbnamehooklist_t           v6;
 194         dns_adbfetch_t                 *fetch_a;
 195         dns_adbfetch_t                 *fetch_aaaa;
 196         unsigned int                    fetch_err;
 197         unsigned int                    fetch6_err;
 198         dns_adbfindlist_t               finds;
 199         ISC_LINK(dns_adbname_t)         plink;
 200 };
 201
 202 /*% The adbfetch structure */
 203 struct dns_adbfetch {
 204         unsigned int                    magic;
 205         dns_adbnamehook_t              *namehook;
 206         dns_adbentry_t                 *entry;
 207         dns_fetch_t                    *fetch;
 208         dns_rdataset_t                  rdataset;
 209 };
 210
 211 /*%
 212  * This is a small widget that dangles off a dns_adbname_t.  It contains a
 213  * pointer to the address information about this host, and a link to the next
 214  * namehook that will contain the next address this host has.
 215  */
 216 struct dns_adbnamehook {
 217         unsigned int                    magic;
 218         dns_adbentry_t                 *entry;
 219         ISC_LINK(dns_adbnamehook_t)     plink;
 220 };
 221
 222 /*%
 223  * This is a small widget that holds qname-specific information about an
 224  * address.  Currently limited to lameness, but could just as easily be
 225  * extended to other types of information about zones.
 226  */
 227 struct dns_adblameinfo {
 228         unsigned int                    magic;
 229
 230         dns_name_t                      qname;
 231         dns_rdatatype_t                 qtype;
 232         isc_stdtime_t                   lame_timer;
 233
 234         ISC_LINK(dns_adblameinfo_t)     plink;
 235 };
 236
 237 /*%
 238  * An address entry.  It holds quite a bit of information about addresses,
 239  * including edns state (in "flags"), rtt, and of course the address of
 240  * the host.
 241  */
 242 struct dns_adbentry {
 243         unsigned int                    magic;
 244
 245         int                             lock_bucket;
 246         unsigned int                    refcnt;
 247
 248         unsigned int                    flags;
 249         unsigned int                    srtt;
 250         isc_sockaddr_t                  sockaddr;
 251
 252         isc_stdtime_t                   expires;
 253         /*%<
 254          * A nonzero 'expires' field indicates that the entry should
 255          * persist until that time.  This allows entries found
 256          * using dns_adb_findaddrinfo() to persist for a limited time
 257          * even though they are not necessarily associated with a
 258          * name.
 259          */
 260
 261         ISC_LIST(dns_adblameinfo_t)     lameinfo;
 262         ISC_LINK(dns_adbentry_t)        plink;
 263 };
 264
 265 /*
 266  * Internal functions (and prototypes).
 267  */
 268 static inline dns_adbname_t *new_adbname(dns_adb_t *, dns_name_t *);
 269 static inline void free_adbname(dns_adb_t *, dns_adbname_t **);
 270 static inline dns_adbnamehook_t *new_adbnamehook(dns_adb_t *,
 271                                                  dns_adbentry_t *);
 272 static inline void free_adbnamehook(dns_adb_t *, dns_adbnamehook_t **);
 273 static inline dns_adblameinfo_t *new_adblameinfo(dns_adb_t *, dns_name_t *,
 274                                                  dns_rdatatype_t);
 275 static inline void free_adblameinfo(dns_adb_t *, dns_adblameinfo_t **);
 276 static inline dns_adbentry_t *new_adbentry(dns_adb_t *);
 277 static inline void free_adbentry(dns_adb_t *, dns_adbentry_t **);
 278 static inline dns_adbfind_t *new_adbfind(dns_adb_t *);
 279 static inline isc_boolean_t free_adbfind(dns_adb_t *, dns_adbfind_t **);
 280 static inline dns_adbaddrinfo_t *new_adbaddrinfo(dns_adb_t *, dns_adbentry_t *,
 281                                                  in_port_t);
 282 static inline dns_adbfetch_t *new_adbfetch(dns_adb_t *);
 283 static inline void free_adbfetch(dns_adb_t *, dns_adbfetch_t **);
 284 static inline dns_adbname_t *find_name_and_lock(dns_adb_t *, dns_name_t *,
 285                                                 unsigned int, int *);
 286 static inline dns_adbentry_t *find_entry_and_lock(dns_adb_t *,
 287                                                   isc_sockaddr_t *, int *);
 288 static void dump_adb(dns_adb_t *, FILE *, isc_boolean_t debug, isc_stdtime_t);
 289 static void print_dns_name(FILE *, dns_name_t *);
 290 static void print_namehook_list(FILE *, const char *legend,
 291                                 dns_adbnamehooklist_t *list,
 292                                 isc_boolean_t debug,
 293                                 isc_stdtime_t now);
 294 static void print_find_list(FILE *, dns_adbname_t *);
 295 static void print_fetch_list(FILE *, dns_adbname_t *);
 296 static inline isc_boolean_t dec_adb_irefcnt(dns_adb_t *);
 297 static inline void inc_adb_irefcnt(dns_adb_t *);
 298 static inline void inc_adb_erefcnt(dns_adb_t *);
 299 static inline void inc_entry_refcnt(dns_adb_t *, dns_adbentry_t *,
 300                                     isc_boolean_t);
 301 static inline isc_boolean_t dec_entry_refcnt(dns_adb_t *, dns_adbentry_t *,
 302                                              isc_boolean_t);
 303 static inline void violate_locking_hierarchy(isc_mutex_t *, isc_mutex_t *);
 304 static isc_boolean_t clean_namehooks(dns_adb_t *, dns_adbnamehooklist_t *);
 305 static void clean_target(dns_adb_t *, dns_name_t *);
 306 static void clean_finds_at_name(dns_adbname_t *, isc_eventtype_t,
 307                                 unsigned int);
 308 static isc_boolean_t check_expire_namehooks(dns_adbname_t *, isc_stdtime_t,
 309                                             isc_boolean_t);
 310 static void cancel_fetches_at_name(dns_adbname_t *);
 311 static isc_result_t dbfind_name(dns_adbname_t *, isc_stdtime_t,
 312                                 dns_rdatatype_t);
 313 static isc_result_t fetch_name(dns_adbname_t *, isc_boolean_t,
 314                                dns_rdatatype_t);
 315 static inline void check_exit(dns_adb_t *);
 316 static void timer_cleanup(isc_task_t *, isc_event_t *);
 317 static void destroy(dns_adb_t *);
 318 static isc_boolean_t shutdown_names(dns_adb_t *);
 319 static isc_boolean_t shutdown_entries(dns_adb_t *);
 320 static inline void link_name(dns_adb_t *, int, dns_adbname_t *);
 321 static inline isc_boolean_t unlink_name(dns_adb_t *, dns_adbname_t *);
 322 static inline void link_entry(dns_adb_t *, int, dns_adbentry_t *);
 323 static inline isc_boolean_t unlink_entry(dns_adb_t *, dns_adbentry_t *);
 324 static isc_boolean_t kill_name(dns_adbname_t **, isc_eventtype_t);
 325 static void water(void *, int);
 326 static void dump_entry(FILE *, dns_adbentry_t *, isc_boolean_t, isc_stdtime_t);
 327
 328 /*
 329  * MUST NOT overlap DNS_ADBFIND_* flags!
 330  */
 331 #define FIND_EVENT_SENT         0x40000000
 332 #define FIND_EVENT_FREED        0x80000000
 333 #define FIND_EVENTSENT(h)       (((h)->flags & FIND_EVENT_SENT) != 0)
 334 #define FIND_EVENTFREED(h)      (((h)->flags & FIND_EVENT_FREED) != 0)
 335
 336 #define NAME_NEEDS_POKE         0x80000000
 337 #define NAME_IS_DEAD            0x40000000
 338 #define NAME_HINT_OK            DNS_ADBFIND_HINTOK
 339 #define NAME_GLUE_OK            DNS_ADBFIND_GLUEOK
 340 #define NAME_STARTATZONE        DNS_ADBFIND_STARTATZONE
 341 #define NAME_DEAD(n)            (((n)->flags & NAME_IS_DEAD) != 0)
 342 #define NAME_NEEDSPOKE(n)       (((n)->flags & NAME_NEEDS_POKE) != 0)
 343 #define NAME_GLUEOK(n)          (((n)->flags & NAME_GLUE_OK) != 0)
 344 #define NAME_HINTOK(n)          (((n)->flags & NAME_HINT_OK) != 0)
 345
 346 /*
 347  * To the name, address classes are all that really exist.  If it has a
 348  * V6 address it doesn't care if it came from a AAAA query.
 349  */
 350 #define NAME_HAS_V4(n)          (!ISC_LIST_EMPTY((n)->v4))
 351 #define NAME_HAS_V6(n)          (!ISC_LIST_EMPTY((n)->v6))
 352 #define NAME_HAS_ADDRS(n)       (NAME_HAS_V4(n) || NAME_HAS_V6(n))
 353
 354 /*
 355  * Fetches are broken out into A and AAAA types.  In some cases,
 356  * however, it makes more sense to test for a particular class of fetches,
 357  * like V4 or V6 above.
 358  * Note: since we have removed the support of A6 in adb, FETCH_A and FETCH_AAAA
 359  * are now equal to FETCH_V4 and FETCH_V6, respectively.
 360  */
 361 #define NAME_FETCH_A(n)         ((n)->fetch_a != NULL)
 362 #define NAME_FETCH_AAAA(n)      ((n)->fetch_aaaa != NULL)
 363 #define NAME_FETCH_V4(n)        (NAME_FETCH_A(n))
 364 #define NAME_FETCH_V6(n)        (NAME_FETCH_AAAA(n))
 365 #define NAME_FETCH(n)           (NAME_FETCH_V4(n) || NAME_FETCH_V6(n))
 366
 367 /*
 368  * Find options and tests to see if there are addresses on the list.
 369  */
 370 #define FIND_WANTEVENT(fn)      (((fn)->options & DNS_ADBFIND_WANTEVENT) != 0)
 371 #define FIND_WANTEMPTYEVENT(fn) (((fn)->options & DNS_ADBFIND_EMPTYEVENT) != 0)
 372 #define FIND_AVOIDFETCHES(fn)   (((fn)->options & DNS_ADBFIND_AVOIDFETCHES) \
 373                                  != 0)
 374 #define FIND_STARTATZONE(fn)    (((fn)->options & DNS_ADBFIND_STARTATZONE) \
 375                                  != 0)
 376 #define FIND_HINTOK(fn)         (((fn)->options & DNS_ADBFIND_HINTOK) != 0)
 377 #define FIND_GLUEOK(fn)         (((fn)->options & DNS_ADBFIND_GLUEOK) != 0)
 378 #define FIND_HAS_ADDRS(fn)      (!ISC_LIST_EMPTY((fn)->list))
 379 #define FIND_RETURNLAME(fn)     (((fn)->options & DNS_ADBFIND_RETURNLAME) != 0)
 380
 381 /*
 382  * These are currently used on simple unsigned ints, so they are
 383  * not really associated with any particular type.
 384  */
 385 #define WANT_INET(x)            (((x) & DNS_ADBFIND_INET) != 0)
 386 #define WANT_INET6(x)           (((x) & DNS_ADBFIND_INET6) != 0)
 387
 388 #define EXPIRE_OK(exp, now)     ((exp == INT_MAX) || (exp < now))
 389
 390 /*
 391  * Find out if the flags on a name (nf) indicate if it is a hint or
 392  * glue, and compare this to the appropriate bits set in o, to see if
 393  * this is ok.
 394  */
 395 #define GLUE_OK(nf, o) (!NAME_GLUEOK(nf) || (((o) & DNS_ADBFIND_GLUEOK) != 0))
 396 #define HINT_OK(nf, o) (!NAME_HINTOK(nf) || (((o) & DNS_ADBFIND_HINTOK) != 0))
 397 #define GLUEHINT_OK(nf, o) (GLUE_OK(nf, o) || HINT_OK(nf, o))
 398 #define STARTATZONE_MATCHES(nf, o) (((nf)->flags & NAME_STARTATZONE) == \
 399                                     ((o) & DNS_ADBFIND_STARTATZONE))
 400
 401 #define ENTER_LEVEL             ISC_LOG_DEBUG(50)
 402 #define EXIT_LEVEL              ENTER_LEVEL
 403 #define CLEAN_LEVEL             ISC_LOG_DEBUG(100)
 404 #define DEF_LEVEL               ISC_LOG_DEBUG(5)
 405 #define NCACHE_LEVEL            ISC_LOG_DEBUG(20)
 406
 407 #define NCACHE_RESULT(r)        ((r) == DNS_R_NCACHENXDOMAIN || \
 408                                  (r) == DNS_R_NCACHENXRRSET)
 409 #define AUTH_NX(r)              ((r) == DNS_R_NXDOMAIN || \
 410                                  (r) == DNS_R_NXRRSET)
 411 #define NXDOMAIN_RESULT(r)      ((r) == DNS_R_NXDOMAIN || \
 412                                  (r) == DNS_R_NCACHENXDOMAIN)
 413 #define NXRRSET_RESULT(r)       ((r) == DNS_R_NCACHENXRRSET || \
 414                                  (r) == DNS_R_NXRRSET || \
 415                                  (r) == DNS_R_HINTNXRRSET)
 416
 417 /*
 418  * Error state rankings.
 419  */
 420
 421 #define FIND_ERR_SUCCESS                0  /* highest rank */
 422 #define FIND_ERR_CANCELED               1
 423 #define FIND_ERR_FAILURE                2
 424 #define FIND_ERR_NXDOMAIN               3
 425 #define FIND_ERR_NXRRSET                4
 426 #define FIND_ERR_UNEXPECTED             5
 427 #define FIND_ERR_NOTFOUND               6
 428 #define FIND_ERR_MAX                    7
 429
 430 static const char *errnames[] = {
 431         "success",
 432         "canceled",
 433         "failure",
 434         "nxdomain",
 435         "nxrrset",
 436         "unexpected",
 437         "not_found"
 438 };
 439
 440 #define NEWERR(old, new)        (ISC_MIN((old), (new)))
 441
 442 static isc_result_t find_err_map[FIND_ERR_MAX] = {
 443         ISC_R_SUCCESS,
 444         ISC_R_CANCELED,
 445         ISC_R_FAILURE,
 446         DNS_R_NXDOMAIN,
 447         DNS_R_NXRRSET,
 448         ISC_R_UNEXPECTED,
 449         ISC_R_NOTFOUND          /* not YET found */
 450 };
 451
 452 static void
 453 DP(int level, const char *format, ...) ISC_FORMAT_PRINTF(2, 3);
 454
 455 static void
 456 DP(int level, const char *format, ...) {
 457         va_list args;
 458
 459         va_start(args, format);
 460         isc_log_vwrite(dns_lctx,
 461                        DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_ADB,
 462                        level, format, args);
 463         va_end(args);
 464 }
 465
 466 static inline dns_ttl_t
 467 ttlclamp(dns_ttl_t ttl) {
 468         if (ttl < ADB_CACHE_MINIMUM)
 469                 ttl = ADB_CACHE_MINIMUM;
 470         if (ttl > ADB_CACHE_MAXIMUM)
 471                 ttl = ADB_CACHE_MAXIMUM;
 472
 473         return (ttl);
 474 }
 475
 476 /*
 477  * Requires the adbname bucket be locked and that no entry buckets be locked.
 478  *
 479  * This code handles A and AAAA rdatasets only.
 480  */
 481 static isc_result_t
 482 import_rdataset(dns_adbname_t *adbname, dns_rdataset_t *rdataset,
 483                 isc_stdtime_t now)
 484 {
 485         isc_result_t result;
 486         dns_adb_t *adb;
 487         dns_adbnamehook_t *nh;
 488         dns_adbnamehook_t *anh;
 489         dns_rdata_t rdata = DNS_RDATA_INIT;
 490         struct in_addr ina;
 491         struct in6_addr in6a;
 492         isc_sockaddr_t sockaddr;
 493         dns_adbentry_t *foundentry;  /* NO CLEAN UP! */
 494         int addr_bucket;
 495         isc_boolean_t new_addresses_added;
 496         dns_rdatatype_t rdtype;
 497         unsigned int findoptions;
 498         dns_adbnamehooklist_t *hookhead;
 499
 500         INSIST(DNS_ADBNAME_VALID(adbname));
 501         adb = adbname->adb;
 502         INSIST(DNS_ADB_VALID(adb));
 503
 504         rdtype = rdataset->type;
 505         INSIST((rdtype == dns_rdatatype_a) || (rdtype == dns_rdatatype_aaaa));
 506         if (rdtype == dns_rdatatype_a)
 507                 findoptions = DNS_ADBFIND_INET;
 508         else
 509                 findoptions = DNS_ADBFIND_INET6;
 510
 511         addr_bucket = DNS_ADB_INVALIDBUCKET;
 512         new_addresses_added = ISC_FALSE;
 513
 514         nh = NULL;
 515         result = dns_rdataset_first(rdataset);
 516         while (result == ISC_R_SUCCESS) {
 517                 dns_rdata_reset(&rdata);
 518                 dns_rdataset_current(rdataset, &rdata);
 519                 if (rdtype == dns_rdatatype_a) {
 520                         INSIST(rdata.length == 4);
 521                         memcpy(&ina.s_addr, rdata.data, 4);
 522                         isc_sockaddr_fromin(&sockaddr, &ina, 0);
 523                         hookhead = &adbname->v4;
 524                 } else {
 525                         INSIST(rdata.length == 16);
 526                         memcpy(in6a.s6_addr, rdata.data, 16);
 527                         isc_sockaddr_fromin6(&sockaddr, &in6a, 0);
 528                         hookhead = &adbname->v6;
 529                 }
 530
 531                 INSIST(nh == NULL);
 532                 nh = new_adbnamehook(adb, NULL);
 533                 if (nh == NULL) {
 534                         adbname->partial_result |= findoptions;
 535                         result = ISC_R_NOMEMORY;
 536                         goto fail;
 537                 }
 538
 539                 foundentry = find_entry_and_lock(adb, &sockaddr, &addr_bucket);
 540                 if (foundentry == NULL) {
 541                         dns_adbentry_t *entry;
 542
 543                         entry = new_adbentry(adb);
 544                         if (entry == NULL) {
 545                                 adbname->partial_result |= findoptions;
 546                                 result = ISC_R_NOMEMORY;
 547                                 goto fail;
 548                         }
 549
 550                         entry->sockaddr = sockaddr;
 551                         entry->refcnt = 1;
 552
 553                         nh->entry = entry;
 554
 555                         link_entry(adb, addr_bucket, entry);
 556                 } else {
 557                         for (anh = ISC_LIST_HEAD(*hookhead);
 558                              anh != NULL;
 559                              anh = ISC_LIST_NEXT(anh, plink))
 560                                 if (anh->entry == foundentry)
 561                                         break;
 562                         if (anh == NULL) {
 563                                 foundentry->refcnt++;
 564                                 nh->entry = foundentry;
 565                         } else
 566                                 free_adbnamehook(adb, &nh);
 567                 }
 568
 569                 new_addresses_added = ISC_TRUE;
 570                 if (nh != NULL)
 571                         ISC_LIST_APPEND(*hookhead, nh, plink);
 572                 nh = NULL;
 573                 result = dns_rdataset_next(rdataset);
 574         }
 575
 576  fail:
 577         if (nh != NULL)
 578                 free_adbnamehook(adb, &nh);
 579
 580         if (addr_bucket != DNS_ADB_INVALIDBUCKET)
 581                 UNLOCK(&adb->entrylocks[addr_bucket]);
 582
 583         if (rdataset->trust == dns_trust_glue ||
 584             rdataset->trust == dns_trust_additional)
 585                 rdataset->ttl = ADB_CACHE_MINIMUM;
 586         else
 587                 rdataset->ttl = ttlclamp(rdataset->ttl);
 588
 589         if (rdtype == dns_rdatatype_a) {
 590                 DP(NCACHE_LEVEL, "expire_v4 set to MIN(%u,%u) import_rdataset",
 591                    adbname->expire_v4, now + rdataset->ttl);
 592                 adbname->expire_v4 = ISC_MIN(adbname->expire_v4,
 593                                              now + rdataset->ttl);
 594         } else {
 595                 DP(NCACHE_LEVEL, "expire_v6 set to MIN(%u,%u) import_rdataset",
 596                    adbname->expire_v6, now + rdataset->ttl);
 597                 adbname->expire_v6 = ISC_MIN(adbname->expire_v6,
 598                                              now + rdataset->ttl);
 599         }
 600
 601         if (new_addresses_added) {
 602                 /*
 603                  * Lie a little here.  This is more or less so code that cares
 604                  * can find out if any new information was added or not.
 605                  */
 606                 return (ISC_R_SUCCESS);
 607         }
 608
 609         return (result);
 610 }
 611
 612 /*
 613  * Requires the name's bucket be locked.
 614  */
 615 static isc_boolean_t
 616 kill_name(dns_adbname_t **n, isc_eventtype_t ev) {
 617         dns_adbname_t *name;
 618         isc_boolean_t result = ISC_FALSE;
 619         isc_boolean_t result4, result6;
 620         dns_adb_t *adb;
 621
 622         INSIST(n != NULL);
 623         name = *n;
 624         *n = NULL;
 625         INSIST(DNS_ADBNAME_VALID(name));
 626         adb = name->adb;
 627         INSIST(DNS_ADB_VALID(adb));
 628
 629         DP(DEF_LEVEL, "killing name %p", name);
 630
 631         /*
 632          * If we're dead already, just check to see if we should go
 633          * away now or not.
 634          */
 635         if (NAME_DEAD(name) && !NAME_FETCH(name)) {
 636                 result = unlink_name(adb, name);
 637                 free_adbname(adb, &name);
 638                 if (result)
 639                         result = dec_adb_irefcnt(adb);
 640                 return (result);
 641         }
 642
 643         /*
 644          * Clean up the name's various lists.  These two are destructive
 645          * in that they will always empty the list.
 646          */
 647         clean_finds_at_name(name, ev, DNS_ADBFIND_ADDRESSMASK);
 648         result4 = clean_namehooks(adb, &name->v4);
 649         result6 = clean_namehooks(adb, &name->v6);
 650         clean_target(adb, &name->target);
 651         result = ISC_TF(result4 || result6);
 652
 653         /*
 654          * If fetches are running, cancel them.  If none are running, we can
 655          * just kill the name here.
 656          */
 657         if (!NAME_FETCH(name)) {
 658                 INSIST(result == ISC_FALSE);
 659                 result = unlink_name(adb, name);
 660                 free_adbname(adb, &name);
 661                 if (result)
 662                         result = dec_adb_irefcnt(adb);
 663         } else {
 664                 name->flags |= NAME_IS_DEAD;
 665                 cancel_fetches_at_name(name);
 666         }
 667         return (result);
 668 }
 669
 670 /*
 671  * Requires the name's bucket be locked and no entry buckets be locked.
 672  */
 673 static isc_boolean_t
 674 check_expire_namehooks(dns_adbname_t *name, isc_stdtime_t now,
 675                        isc_boolean_t overmem)
 676 {
 677         dns_adb_t *adb;
 678         isc_boolean_t expire;
 679         isc_boolean_t result4 = ISC_FALSE;
 680         isc_boolean_t result6 = ISC_FALSE;
 681
 682         INSIST(DNS_ADBNAME_VALID(name));
 683         adb = name->adb;
 684         INSIST(DNS_ADB_VALID(adb));
 685
 686         if (overmem) {
 687                 isc_uint32_t val;
 688
 689                 isc_random_get(&val);
 690
 691                 expire = ISC_TF((val % 4) == 0);
 692         } else
 693                 expire = ISC_FALSE;
 694
 695         /*
 696          * Check to see if we need to remove the v4 addresses
 697          */
 698         if (!NAME_FETCH_V4(name) &&
 699             (expire || EXPIRE_OK(name->expire_v4, now))) {
 700                 if (NAME_HAS_V4(name)) {
 701                         DP(DEF_LEVEL, "expiring v4 for name %p", name);
 702                         result4 = clean_namehooks(adb, &name->v4);
 703                         name->partial_result &= ~DNS_ADBFIND_INET;
 704                 }
 705                 name->expire_v4 = INT_MAX;
 706                 name->fetch_err = FIND_ERR_UNEXPECTED;
 707         }
 708
 709         /*
 710          * Check to see if we need to remove the v6 addresses
 711          */
 712         if (!NAME_FETCH_V6(name) &&
 713             (expire || EXPIRE_OK(name->expire_v6, now))) {
 714                 if (NAME_HAS_V6(name)) {
 715                         DP(DEF_LEVEL, "expiring v6 for name %p", name);
 716                         result6 = clean_namehooks(adb, &name->v6);
 717                         name->partial_result &= ~DNS_ADBFIND_INET6;
 718                 }
 719                 name->expire_v6 = INT_MAX;
 720                 name->fetch6_err = FIND_ERR_UNEXPECTED;
 721         }
 722
 723         /*
 724          * Check to see if we need to remove the alias target.
 725          */
 726         if (expire || EXPIRE_OK(name->expire_target, now)) {
 727                 clean_target(adb, &name->target);
 728                 name->expire_target = INT_MAX;
 729         }
 730         return (ISC_TF(result4 || result6));
 731 }
 732
 733 /*
 734  * Requires the name's bucket be locked.
 735  */
 736 static inline void
 737 link_name(dns_adb_t *adb, int bucket, dns_adbname_t *name) {
 738         INSIST(name->lock_bucket == DNS_ADB_INVALIDBUCKET);
 739
 740         ISC_LIST_PREPEND(adb->names[bucket], name, plink);
 741         name->lock_bucket = bucket;
 742         adb->name_refcnt[bucket]++;
 743 }
 744
 745 /*
 746  * Requires the name's bucket be locked.
 747  */
 748 static inline isc_boolean_t
 749 unlink_name(dns_adb_t *adb, dns_adbname_t *name) {
 750         int bucket;
 751         isc_boolean_t result = ISC_FALSE;
 752
 753         bucket = name->lock_bucket;
 754         INSIST(bucket != DNS_ADB_INVALIDBUCKET);
 755
 756         ISC_LIST_UNLINK(adb->names[bucket], name, plink);
 757         name->lock_bucket = DNS_ADB_INVALIDBUCKET;
 758         INSIST(adb->name_refcnt[bucket] > 0);
 759         adb->name_refcnt[bucket]--;
 760         if (adb->name_sd[bucket] && adb->name_refcnt[bucket] == 0)
 761                 result = ISC_TRUE;
 762         return (result);
 763 }
 764
 765 /*
 766  * Requires the entry's bucket be locked.
 767  */
 768 static inline void
 769 link_entry(dns_adb_t *adb, int bucket, dns_adbentry_t *entry) {
 770         ISC_LIST_PREPEND(adb->entries[bucket], entry, plink);
 771         entry->lock_bucket = bucket;
 772         adb->entry_refcnt[bucket]++;
 773 }
 774
 775 /*
 776  * Requires the entry's bucket be locked.
 777  */
 778 static inline isc_boolean_t
 779 unlink_entry(dns_adb_t *adb, dns_adbentry_t *entry) {
 780         int bucket;
 781         isc_boolean_t result = ISC_FALSE;
 782
 783         bucket = entry->lock_bucket;
 784         INSIST(bucket != DNS_ADB_INVALIDBUCKET);
 785
 786         ISC_LIST_UNLINK(adb->entries[bucket], entry, plink);
 787         entry->lock_bucket = DNS_ADB_INVALIDBUCKET;
 788         INSIST(adb->entry_refcnt[bucket] > 0);
 789         adb->entry_refcnt[bucket]--;
 790         if (adb->entry_sd[bucket] && adb->entry_refcnt[bucket] == 0)
 791                 result = ISC_TRUE;
 792         return (result);
 793 }
 794
 795 static inline void
 796 violate_locking_hierarchy(isc_mutex_t *have, isc_mutex_t *want) {
 797         if (isc_mutex_trylock(want) != ISC_R_SUCCESS) {
 798                 UNLOCK(have);
 799                 LOCK(want);
 800                 LOCK(have);
 801         }
 802 }
 803
 804 /*
 805  * The ADB _MUST_ be locked before calling.  Also, exit conditions must be
 806  * checked after calling this function.
 807  */
 808 static isc_boolean_t
 809 shutdown_names(dns_adb_t *adb) {
 810         int bucket;
 811         isc_boolean_t result = ISC_FALSE;
 812         dns_adbname_t *name;
 813         dns_adbname_t *next_name;
 814
 815         for (bucket = 0; bucket < NBUCKETS; bucket++) {
 816                 LOCK(&adb->namelocks[bucket]);
 817                 adb->name_sd[bucket] = ISC_TRUE;
 818
 819                 name = ISC_LIST_HEAD(adb->names[bucket]);
 820                 if (name == NULL) {
 821                         /*
 822                          * This bucket has no names.  We must decrement the
 823                          * irefcnt ourselves, since it will not be
 824                          * automatically triggered by a name being unlinked.
 825                          */
 826                         INSIST(result == ISC_FALSE);
 827                         result = dec_adb_irefcnt(adb);
 828                 } else {
 829                         /*
 830                          * Run through the list.  For each name, clean up finds
 831                          * found there, and cancel any fetches running.  When
 832                          * all the fetches are canceled, the name will destroy
 833                          * itself.
 834                          */
 835                         while (name != NULL) {
 836                                 next_name = ISC_LIST_NEXT(name, plink);
 837                                 INSIST(result == ISC_FALSE);
 838                                 result = kill_name(&name,
 839                                                    DNS_EVENT_ADBSHUTDOWN);
 840                                 name = next_name;
 841                         }
 842                 }
 843
 844                 UNLOCK(&adb->namelocks[bucket]);
 845         }
 846         return (result);
 847 }
 848
 849 /*
 850  * The ADB _MUST_ be locked before calling.  Also, exit conditions must be
 851  * checked after calling this function.
 852  */
 853 static isc_boolean_t
 854 shutdown_entries(dns_adb_t *adb) {
 855         int bucket;
 856         isc_boolean_t result = ISC_FALSE;
 857         dns_adbentry_t *entry;
 858         dns_adbentry_t *next_entry;
 859
 860         for (bucket = 0; bucket < NBUCKETS; bucket++) {
 861                 LOCK(&adb->entrylocks[bucket]);
 862                 adb->entry_sd[bucket] = ISC_TRUE;
 863
 864                 entry = ISC_LIST_HEAD(adb->entries[bucket]);
 865                 if (entry == NULL) {
 866                         /*
 867                          * This bucket has no entries.  We must decrement the
 868                          * irefcnt ourselves, since it will not be
 869                          * automatically triggered by an entry being unlinked.
 870                          */
 871                         result = dec_adb_irefcnt(adb);
 872                 } else {
 873                         /*
 874                          * Run through the list.  Cleanup any entries not
 875                          * associated with names, and which are not in use.
 876                          */
 877                         while (entry != NULL) {
 878                                 next_entry = ISC_LIST_NEXT(entry, plink);
 879                                 if (entry->refcnt == 0 &&
 880                                     entry->expires != 0) {
 881                                         result = unlink_entry(adb, entry);
 882                                         free_adbentry(adb, &entry);
 883                                         if (result)
 884                                                 result = dec_adb_irefcnt(adb);
 885                                 }
 886                                 entry = next_entry;
 887                         }
 888                 }
 889
 890                 UNLOCK(&adb->entrylocks[bucket]);
 891         }
 892         return (result);
 893 }
 894
 895 /*
 896  * Name bucket must be locked
 897  */
 898 static void
 899 cancel_fetches_at_name(dns_adbname_t *name) {
 900         if (NAME_FETCH_A(name))
 901             dns_resolver_cancelfetch(name->fetch_a->fetch);
 902
 903         if (NAME_FETCH_AAAA(name))
 904             dns_resolver_cancelfetch(name->fetch_aaaa->fetch);
 905 }
 906
 907 /*
 908  * Assumes the name bucket is locked.
 909  */
 910 static isc_boolean_t
 911 clean_namehooks(dns_adb_t *adb, dns_adbnamehooklist_t *namehooks) {
 912         dns_adbentry_t *entry;
 913         dns_adbnamehook_t *namehook;
 914         int addr_bucket;
 915         isc_boolean_t result = ISC_FALSE;
 916
 917         addr_bucket = DNS_ADB_INVALIDBUCKET;
 918         namehook = ISC_LIST_HEAD(*namehooks);
 919         while (namehook != NULL) {
 920                 INSIST(DNS_ADBNAMEHOOK_VALID(namehook));
 921
 922                 /*
 923                  * Clean up the entry if needed.
 924                  */
 925                 entry = namehook->entry;
 926                 if (entry != NULL) {
 927                         INSIST(DNS_ADBENTRY_VALID(entry));
 928
 929                         if (addr_bucket != entry->lock_bucket) {
 930                                 if (addr_bucket != DNS_ADB_INVALIDBUCKET)
 931                                         UNLOCK(&adb->entrylocks[addr_bucket]);
 932                                 addr_bucket = entry->lock_bucket;
 933                                 LOCK(&adb->entrylocks[addr_bucket]);
 934                         }
 935
 936                         result = dec_entry_refcnt(adb, entry, ISC_FALSE);
 937                 }
 938
 939                 /*
 940                  * Free the namehook
 941                  */
 942                 namehook->entry = NULL;
 943                 ISC_LIST_UNLINK(*namehooks, namehook, plink);
 944                 free_adbnamehook(adb, &namehook);
 945
 946                 namehook = ISC_LIST_HEAD(*namehooks);
 947         }
 948
 949         if (addr_bucket != DNS_ADB_INVALIDBUCKET)
 950                 UNLOCK(&adb->entrylocks[addr_bucket]);
 951         return (result);
 952 }
 953
 954 static void
 955 clean_target(dns_adb_t *adb, dns_name_t *target) {
 956         if (dns_name_countlabels(target) > 0) {
 957                 dns_name_free(target, adb->mctx);
 958                 dns_name_init(target, NULL);
 959         }
 960 }
 961
 962 static isc_result_t
 963 set_target(dns_adb_t *adb, dns_name_t *name, dns_name_t *fname,
 964            dns_rdataset_t *rdataset, dns_name_t *target)
 965 {
 966         isc_result_t result;
 967         dns_namereln_t namereln;
 968         unsigned int nlabels;
 969         int order;
 970         dns_rdata_t rdata = DNS_RDATA_INIT;
 971         dns_fixedname_t fixed1, fixed2;
 972         dns_name_t *prefix, *new_target;
 973
 974         REQUIRE(dns_name_countlabels(target) == 0);
 975
 976         if (rdataset->type == dns_rdatatype_cname) {
 977                 dns_rdata_cname_t cname;
 978
 979                 /*
 980                  * Copy the CNAME's target into the target name.
 981                  */
 982                 result = dns_rdataset_first(rdataset);
 983                 if (result != ISC_R_SUCCESS)
 984                         return (result);
 985                 dns_rdataset_current(rdataset, &rdata);
 986                 result = dns_rdata_tostruct(&rdata, &cname, NULL);
 987                 if (result != ISC_R_SUCCESS)
 988                         return (result);
 989                 result = dns_name_dup(&cname.cname, adb->mctx, target);
 990                 dns_rdata_freestruct(&cname);
 991                 if (result != ISC_R_SUCCESS)
 992                         return (result);
 993         } else {
 994                 dns_rdata_dname_t dname;
 995
 996                 INSIST(rdataset->type == dns_rdatatype_dname);
 997                 namereln = dns_name_fullcompare(name, fname, &order, &nlabels);
 998                 INSIST(namereln == dns_namereln_subdomain);
 999                 /*
1000                  * Get the target name of the DNAME.
1001                  */
1002                 result = dns_rdataset_first(rdataset);
1003                 if (result != ISC_R_SUCCESS)
1004                         return (result);
1005                 dns_rdataset_current(rdataset, &rdata);
1006                 result = dns_rdata_tostruct(&rdata, &dname, NULL);
1007                 if (result != ISC_R_SUCCESS)
1008                         return (result);
1009                 /*
1010                  * Construct the new target name.
1011                  */
1012                 dns_fixedname_init(&fixed1);
1013                 prefix = dns_fixedname_name(&fixed1);
1014                 dns_fixedname_init(&fixed2);
1015                 new_target = dns_fixedname_name(&fixed2);
1016                 dns_name_split(name, nlabels, prefix, NULL);
1017                 result = dns_name_concatenate(prefix, &dname.dname, new_target,
1018                                               NULL);
1019                 dns_rdata_freestruct(&dname);
1020                 if (result != ISC_R_SUCCESS)
1021                         return (result);
1022                 result = dns_name_dup(new_target, adb->mctx, target);
1023                 if (result != ISC_R_SUCCESS)
1024                         return (result);
1025         }
1026
1027         return (ISC_R_SUCCESS);
1028 }
1029
1030 /*
1031  * Assumes nothing is locked, since this is called by the client.
1032  */
1033 static void
1034 event_free(isc_event_t *event) {
1035         dns_adbfind_t *find;
1036
1037         INSIST(event != NULL);
1038         find = event->ev_destroy_arg;
1039         INSIST(DNS_ADBFIND_VALID(find));
1040
1041         LOCK(&find->lock);
1042         find->flags |= FIND_EVENT_FREED;
1043         event->ev_destroy_arg = NULL;
1044         UNLOCK(&find->lock);
1045 }
1046
1047 /*
1048  * Assumes the name bucket is locked.
1049  */
1050 static void
1051 clean_finds_at_name(dns_adbname_t *name, isc_eventtype_t evtype,
1052                     unsigned int addrs)
1053 {
1054         isc_event_t *ev;
1055         isc_task_t *task;
1056         dns_adbfind_t *find;
1057         dns_adbfind_t *next_find;
1058         isc_boolean_t process;
1059         unsigned int wanted, notify;
1060
1061         DP(ENTER_LEVEL,
1062            "ENTER clean_finds_at_name, name %p, evtype %08x, addrs %08x",
1063            name, evtype, addrs);
1064
1065         find = ISC_LIST_HEAD(name->finds);
1066         while (find != NULL) {
1067                 LOCK(&find->lock);
1068                 next_find = ISC_LIST_NEXT(find, plink);
1069
1070                 process = ISC_FALSE;
1071                 wanted = find->flags & DNS_ADBFIND_ADDRESSMASK;
1072                 notify = wanted & addrs;
1073
1074                 switch (evtype) {
1075                 case DNS_EVENT_ADBMOREADDRESSES:
1076                         DP(ISC_LOG_DEBUG(3), "DNS_EVENT_ADBMOREADDRESSES");
1077                         if ((notify) != 0) {
1078                                 find->flags &= ~addrs;
1079                                 process = ISC_TRUE;
1080                         }
1081                         break;
1082                 case DNS_EVENT_ADBNOMOREADDRESSES:
1083                         DP(ISC_LOG_DEBUG(3), "DNS_EVENT_ADBNOMOREADDRESSES");
1084                         find->flags &= ~addrs;
1085                         wanted = find->flags & DNS_ADBFIND_ADDRESSMASK;
1086                         if (wanted == 0)
1087                                 process = ISC_TRUE;
1088                         break;
1089                 default:
1090                         find->flags &= ~addrs;
1091                         process = ISC_TRUE;
1092                 }
1093
1094                 if (process) {
1095                         DP(DEF_LEVEL, "cfan: processing find %p", find);
1096                         /*
1097                          * Unlink the find from the name, letting the caller
1098                          * call dns_adb_destroyfind() on it to clean it up
1099                          * later.
1100                          */
1101                         ISC_LIST_UNLINK(name->finds, find, plink);
1102                         find->adbname = NULL;
1103                         find->name_bucket = DNS_ADB_INVALIDBUCKET;
1104
1105                         INSIST(!FIND_EVENTSENT(find));
1106
1107                         ev = &find->event;
1108                         task = ev->ev_sender;
1109                         ev->ev_sender = find;
1110                         find->result_v4 = find_err_map[name->fetch_err];
1111                         find->result_v6 = find_err_map[name->fetch6_err];
1112                         ev->ev_type = evtype;
1113                         ev->ev_destroy = event_free;
1114                         ev->ev_destroy_arg = find;
1115
1116                         DP(DEF_LEVEL,
1117                            "sending event %p to task %p for find %p",
1118                            ev, task, find);
1119
1120                         isc_task_sendanddetach(&task, (isc_event_t **)&ev);
1121                 } else {
1122                         DP(DEF_LEVEL, "cfan: skipping find %p", find);
1123                 }
1124
1125                 UNLOCK(&find->lock);
1126                 find = next_find;
1127         }
1128
1129         DP(ENTER_LEVEL, "EXIT clean_finds_at_name, name %p", name);
1130 }
1131
1132 static inline void
1133 check_exit(dns_adb_t *adb) {
1134         isc_event_t *event;
1135         /*
1136          * The caller must be holding the adb lock.
1137          */
1138         if (adb->shutting_down) {
1139                 /*
1140                  * If there aren't any external references either, we're
1141                  * done.  Send the control event to initiate shutdown.
1142                  */
1143                 INSIST(!adb->cevent_sent);      /* Sanity check. */
1144                 event = &adb->cevent;
1145                 isc_task_send(adb->task, &event);
1146                 adb->cevent_sent = ISC_TRUE;
1147         }
1148 }
1149
1150 static inline isc_boolean_t
1151 dec_adb_irefcnt(dns_adb_t *adb) {
1152         isc_event_t *event;
1153         isc_task_t *etask;
1154         isc_boolean_t result = ISC_FALSE;
1155
1156         LOCK(&adb->reflock);
1157
1158         INSIST(adb->irefcnt > 0);
1159         adb->irefcnt--;
1160
1161         if (adb->irefcnt == 0) {
1162                 event = ISC_LIST_HEAD(adb->whenshutdown);
1163                 while (event != NULL) {
1164                         ISC_LIST_UNLINK(adb->whenshutdown, event, ev_link);
1165                         etask = event->ev_sender;
1166                         event->ev_sender = adb;
1167                         isc_task_sendanddetach(&etask, &event);
1168                         event = ISC_LIST_HEAD(adb->whenshutdown);
1169                 }
1170         }
1171
1172         if (adb->irefcnt == 0 && adb->erefcnt == 0)
1173                 result = ISC_TRUE;
1174         UNLOCK(&adb->reflock);
1175         return (result);
1176 }
1177
1178 static inline void
1179 inc_adb_irefcnt(dns_adb_t *adb) {
1180         LOCK(&adb->reflock);
1181         adb->irefcnt++;
1182         UNLOCK(&adb->reflock);
1183 }
1184
1185 static inline void
1186 inc_adb_erefcnt(dns_adb_t *adb) {
1187         LOCK(&adb->reflock);
1188         adb->erefcnt++;
1189         UNLOCK(&adb->reflock);
1190 }
1191
1192 static inline void
1193 inc_entry_refcnt(dns_adb_t *adb, dns_adbentry_t *entry, isc_boolean_t lock) {
1194         int bucket;
1195
1196         bucket = entry->lock_bucket;
1197
1198         if (lock)
1199                 LOCK(&adb->entrylocks[bucket]);
1200
1201         entry->refcnt++;
1202
1203         if (lock)
1204                 UNLOCK(&adb->entrylocks[bucket]);
1205 }
1206
1207 static inline isc_boolean_t
1208 dec_entry_refcnt(dns_adb_t *adb, dns_adbentry_t *entry, isc_boolean_t lock) {
1209         int bucket;
1210         isc_boolean_t destroy_entry;
1211         isc_boolean_t result = ISC_FALSE;
1212
1213         bucket = entry->lock_bucket;
1214
1215         if (lock)
1216                 LOCK(&adb->entrylocks[bucket]);
1217
1218         INSIST(entry->refcnt > 0);
1219         entry->refcnt--;
1220
1221         destroy_entry = ISC_FALSE;
1222         if (entry->refcnt == 0 &&
1223             (adb->entry_sd[bucket] || entry->expires == 0)) {
1224                 destroy_entry = ISC_TRUE;
1225                 result = unlink_entry(adb, entry);
1226         }
1227
1228         if (lock)
1229                 UNLOCK(&adb->entrylocks[bucket]);
1230
1231         if (!destroy_entry)
1232                 return (result);
1233
1234         entry->lock_bucket = DNS_ADB_INVALIDBUCKET;
1235
1236         free_adbentry(adb, &entry);
1237         if (result)
1238                 result =dec_adb_irefcnt(adb);
1239
1240         return (result);
1241 }
1242
1243 static inline dns_adbname_t *
1244 new_adbname(dns_adb_t *adb, dns_name_t *dnsname) {
1245         dns_adbname_t *name;
1246
1247         name = isc_mempool_get(adb->nmp);
1248         if (name == NULL)
1249                 return (NULL);
1250
1251         dns_name_init(&name->name, NULL);
1252         if (dns_name_dup(dnsname, adb->mctx, &name->name) != ISC_R_SUCCESS) {
1253                 isc_mempool_put(adb->nmp, name);
1254                 return (NULL);
1255         }
1256         dns_name_init(&name->target, NULL);
1257         name->magic = DNS_ADBNAME_MAGIC;
1258         name->adb = adb;
1259         name->partial_result = 0;
1260         name->flags = 0;
1261         name->expire_v4 = INT_MAX;
1262         name->expire_v6 = INT_MAX;
1263         name->expire_target = INT_MAX;
1264         name->chains = 0;
1265         name->lock_bucket = DNS_ADB_INVALIDBUCKET;
1266         ISC_LIST_INIT(name->v4);
1267         ISC_LIST_INIT(name->v6);
1268         name->fetch_a = NULL;
1269         name->fetch_aaaa = NULL;
1270         name->fetch_err = FIND_ERR_UNEXPECTED;
1271         name->fetch6_err = FIND_ERR_UNEXPECTED;
1272         ISC_LIST_INIT(name->finds);
1273         ISC_LINK_INIT(name, plink);
1274
1275         return (name);
1276 }
1277
1278 static inline void
1279 free_adbname(dns_adb_t *adb, dns_adbname_t **name) {
1280         dns_adbname_t *n;
1281
1282         INSIST(name != NULL && DNS_ADBNAME_VALID(*name));
1283         n = *name;
1284         *name = NULL;
1285
1286         INSIST(!NAME_HAS_V4(n));
1287         INSIST(!NAME_HAS_V6(n));
1288         INSIST(!NAME_FETCH(n));
1289         INSIST(ISC_LIST_EMPTY(n->finds));
1290         INSIST(!ISC_LINK_LINKED(n, plink));
1291         INSIST(n->lock_bucket == DNS_ADB_INVALIDBUCKET);
1292         INSIST(n->adb == adb);
1293
1294         n->magic = 0;
1295         dns_name_free(&n->name, adb->mctx);
1296
1297         isc_mempool_put(adb->nmp, n);
1298 }
1299
1300 static inline dns_adbnamehook_t *
1301 new_adbnamehook(dns_adb_t *adb, dns_adbentry_t *entry) {
1302         dns_adbnamehook_t *nh;
1303
1304         nh = isc_mempool_get(adb->nhmp);
1305         if (nh == NULL)
1306                 return (NULL);
1307
1308         nh->magic = DNS_ADBNAMEHOOK_MAGIC;
1309         nh->entry = entry;
1310         ISC_LINK_INIT(nh, plink);
1311
1312         return (nh);
1313 }
1314
1315 static inline void
1316 free_adbnamehook(dns_adb_t *adb, dns_adbnamehook_t **namehook) {
1317         dns_adbnamehook_t *nh;
1318
1319         INSIST(namehook != NULL && DNS_ADBNAMEHOOK_VALID(*namehook));
1320         nh = *namehook;
1321         *namehook = NULL;
1322
1323         INSIST(nh->entry == NULL);
1324         INSIST(!ISC_LINK_LINKED(nh, plink));
1325
1326         nh->magic = 0;
1327         isc_mempool_put(adb->nhmp, nh);
1328 }
1329
1330 static inline dns_adblameinfo_t *
1331 new_adblameinfo(dns_adb_t *adb, dns_name_t *qname, dns_rdatatype_t qtype) {
1332         dns_adblameinfo_t *li;
1333
1334         li = isc_mempool_get(adb->limp);
1335         if (li == NULL)
1336                 return (NULL);
1337
1338         dns_name_init(&li->qname, NULL);
1339         if (dns_name_dup(qname, adb->mctx, &li->qname) != ISC_R_SUCCESS) {
1340                 isc_mempool_put(adb->limp, li);
1341                 return (NULL);
1342         }
1343         li->magic = DNS_ADBLAMEINFO_MAGIC;
1344         li->lame_timer = 0;
1345         li->qtype = qtype;
1346         ISC_LINK_INIT(li, plink);
1347
1348         return (li);
1349 }
1350
1351 static inline void
1352 free_adblameinfo(dns_adb_t *adb, dns_adblameinfo_t **lameinfo) {
1353         dns_adblameinfo_t *li;
1354
1355         INSIST(lameinfo != NULL && DNS_ADBLAMEINFO_VALID(*lameinfo));
1356         li = *lameinfo;
1357         *lameinfo = NULL;
1358
1359         INSIST(!ISC_LINK_LINKED(li, plink));
1360
1361         dns_name_free(&li->qname, adb->mctx);
1362
1363         li->magic = 0;
1364
1365         isc_mempool_put(adb->limp, li);
1366 }
1367
1368 static inline dns_adbentry_t *
1369 new_adbentry(dns_adb_t *adb) {
1370         dns_adbentry_t *e;
1371         isc_uint32_t r;
1372
1373         e = isc_mempool_get(adb->emp);
1374         if (e == NULL)
1375                 return (NULL);
1376
1377         e->magic = DNS_ADBENTRY_MAGIC;
1378         e->lock_bucket = DNS_ADB_INVALIDBUCKET;
1379         e->refcnt = 0;
1380         e->flags = 0;
1381         isc_random_get(&r);
1382         e->srtt = (r & 0x1f) + 1;
1383         e->expires = 0;
1384         ISC_LIST_INIT(e->lameinfo);
1385         ISC_LINK_INIT(e, plink);
1386
1387         return (e);
1388 }
1389
1390 static inline void
1391 free_adbentry(dns_adb_t *adb, dns_adbentry_t **entry) {
1392         dns_adbentry_t *e;
1393         dns_adblameinfo_t *li;
1394
1395         INSIST(entry != NULL && DNS_ADBENTRY_VALID(*entry));
1396         e = *entry;
1397         *entry = NULL;
1398
1399         INSIST(e->lock_bucket == DNS_ADB_INVALIDBUCKET);
1400         INSIST(e->refcnt == 0);
1401         INSIST(!ISC_LINK_LINKED(e, plink));
1402
1403         e->magic = 0;
1404
1405         li = ISC_LIST_HEAD(e->lameinfo);
1406         while (li != NULL) {
1407                 ISC_LIST_UNLINK(e->lameinfo, li, plink);
1408                 free_adblameinfo(adb, &li);
1409                 li = ISC_LIST_HEAD(e->lameinfo);
1410         }
1411
1412         isc_mempool_put(adb->emp, e);
1413 }
1414
1415 static inline dns_adbfind_t *
1416 new_adbfind(dns_adb_t *adb) {
1417         dns_adbfind_t *h;
1418         isc_result_t result;
1419
1420         h = isc_mempool_get(adb->ahmp);
1421         if (h == NULL)
1422                 return (NULL);
1423
1424         /*
1425          * Public members.
1426          */
1427         h->magic = 0;
1428         h->adb = adb;
1429         h->partial_result = 0;
1430         h->options = 0;
1431         h->flags = 0;
1432         h->result_v4 = ISC_R_UNEXPECTED;
1433         h->result_v6 = ISC_R_UNEXPECTED;
1434         ISC_LINK_INIT(h, publink);
1435         ISC_LINK_INIT(h, plink);
1436         ISC_LIST_INIT(h->list);
1437         h->adbname = NULL;
1438         h->name_bucket = DNS_ADB_INVALIDBUCKET;
1439
1440         /*
1441          * private members
1442          */
1443         result = isc_mutex_init(&h->lock);
1444         if (result != ISC_R_SUCCESS) {
1445                 isc_mempool_put(adb->ahmp, h);
1446                 return (NULL);
1447         }
1448
1449         ISC_EVENT_INIT(&h->event, sizeof(isc_event_t), 0, 0, 0, NULL, NULL,
1450                        NULL, NULL, h);
1451
1452         inc_adb_irefcnt(adb);
1453         h->magic = DNS_ADBFIND_MAGIC;
1454         return (h);
1455 }
1456
1457 static inline dns_adbfetch_t *
1458 new_adbfetch(dns_adb_t *adb) {
1459         dns_adbfetch_t *f;
1460
1461         f = isc_mempool_get(adb->afmp);
1462         if (f == NULL)
1463                 return (NULL);
1464
1465         f->magic = 0;
1466         f->namehook = NULL;
1467         f->entry = NULL;
1468         f->fetch = NULL;
1469
1470         f->namehook = new_adbnamehook(adb, NULL);
1471         if (f->namehook == NULL)
1472                 goto err;
1473
1474         f->entry = new_adbentry(adb);
1475         if (f->entry == NULL)
1476                 goto err;
1477
1478         dns_rdataset_init(&f->rdataset);
1479
1480         f->magic = DNS_ADBFETCH_MAGIC;
1481
1482         return (f);
1483
1484  err:
1485         if (f->namehook != NULL)
1486                 free_adbnamehook(adb, &f->namehook);
1487         if (f->entry != NULL)
1488                 free_adbentry(adb, &f->entry);
1489         isc_mempool_put(adb->afmp, f);
1490         return (NULL);
1491 }
1492
1493 static inline void
1494 free_adbfetch(dns_adb_t *adb, dns_adbfetch_t **fetch) {
1495         dns_adbfetch_t *f;
1496
1497         INSIST(fetch != NULL && DNS_ADBFETCH_VALID(*fetch));
1498         f = *fetch;
1499         *fetch = NULL;
1500
1501         f->magic = 0;
1502
1503         if (f->namehook != NULL)
1504                 free_adbnamehook(adb, &f->namehook);
1505         if (f->entry != NULL)
1506                 free_adbentry(adb, &f->entry);
1507
1508         if (dns_rdataset_isassociated(&f->rdataset))
1509                 dns_rdataset_disassociate(&f->rdataset);
1510
1511         isc_mempool_put(adb->afmp, f);
1512 }
1513
1514 static inline isc_boolean_t
1515 free_adbfind(dns_adb_t *adb, dns_adbfind_t **findp) {
1516         dns_adbfind_t *find;
1517
1518         INSIST(findp != NULL && DNS_ADBFIND_VALID(*findp));
1519         find = *findp;
1520         *findp = NULL;
1521
1522         INSIST(!FIND_HAS_ADDRS(find));
1523         INSIST(!ISC_LINK_LINKED(find, publink));
1524         INSIST(!ISC_LINK_LINKED(find, plink));
1525         INSIST(find->name_bucket == DNS_ADB_INVALIDBUCKET);
1526         INSIST(find->adbname == NULL);
1527
1528         find->magic = 0;
1529
1530         DESTROYLOCK(&find->lock);
1531         isc_mempool_put(adb->ahmp, find);
1532         return (dec_adb_irefcnt(adb));
1533 }
1534
1535 /*
1536  * Copy bits from the entry into the newly allocated addrinfo.  The entry
1537  * must be locked, and the reference count must be bumped up by one
1538  * if this function returns a valid pointer.
1539  */
1540 static inline dns_adbaddrinfo_t *
1541 new_adbaddrinfo(dns_adb_t *adb, dns_adbentry_t *entry, in_port_t port) {
1542         dns_adbaddrinfo_t *ai;
1543
1544         ai = isc_mempool_get(adb->aimp);
1545         if (ai == NULL)
1546                 return (NULL);
1547
1548         ai->magic = DNS_ADBADDRINFO_MAGIC;
1549         ai->sockaddr = entry->sockaddr;
1550         isc_sockaddr_setport(&ai->sockaddr, port);
1551         ai->srtt = entry->srtt;
1552         ai->flags = entry->flags;
1553         ai->entry = entry;
1554         ISC_LINK_INIT(ai, publink);
1555
1556         return (ai);
1557 }
1558
1559 static inline void
1560 free_adbaddrinfo(dns_adb_t *adb, dns_adbaddrinfo_t **ainfo) {
1561         dns_adbaddrinfo_t *ai;
1562
1563         INSIST(ainfo != NULL && DNS_ADBADDRINFO_VALID(*ainfo));
1564         ai = *ainfo;
1565         *ainfo = NULL;
1566
1567         INSIST(ai->entry == NULL);
1568         INSIST(!ISC_LINK_LINKED(ai, publink));
1569
1570         ai->magic = 0;
1571
1572         isc_mempool_put(adb->aimp, ai);
1573 }
1574
1575 /*
1576  * Search for the name.  NOTE:  The bucket is kept locked on both
1577  * success and failure, so it must always be unlocked by the caller!
1578  *
1579  * On the first call to this function, *bucketp must be set to
1580  * DNS_ADB_INVALIDBUCKET.
1581  */
1582 static inline dns_adbname_t *
1583 find_name_and_lock(dns_adb_t *adb, dns_name_t *name,
1584                    unsigned int options, int *bucketp)
1585 {
1586         dns_adbname_t *adbname;
1587         int bucket;
1588
1589         bucket = dns_name_fullhash(name, ISC_FALSE) % NBUCKETS;
1590
1591         if (*bucketp == DNS_ADB_INVALIDBUCKET) {
1592                 LOCK(&adb->namelocks[bucket]);
1593                 *bucketp = bucket;
1594         } else if (*bucketp != bucket) {
1595                 UNLOCK(&adb->namelocks[*bucketp]);
1596                 LOCK(&adb->namelocks[bucket]);
1597                 *bucketp = bucket;
1598         }
1599
1600         adbname = ISC_LIST_HEAD(adb->names[bucket]);
1601         while (adbname != NULL) {
1602                 if (!NAME_DEAD(adbname)) {
1603                         if (dns_name_equal(name, &adbname->name)
1604                             && GLUEHINT_OK(adbname, options)
1605                             && STARTATZONE_MATCHES(adbname, options))
1606                                 return (adbname);
1607                 }
1608                 adbname = ISC_LIST_NEXT(adbname, plink);
1609         }
1610
1611         return (NULL);
1612 }
1613
1614 /*
1615  * Search for the address.  NOTE:  The bucket is kept locked on both
1616  * success and failure, so it must always be unlocked by the caller.
1617  *
1618  * On the first call to this function, *bucketp must be set to
1619  * DNS_ADB_INVALIDBUCKET.  This will cause a lock to occur.  On
1620  * later calls (within the same "lock path") it can be left alone, so
1621  * if this function is called multiple times locking is only done if
1622  * the bucket changes.
1623  */
1624 static inline dns_adbentry_t *
1625 find_entry_and_lock(dns_adb_t *adb, isc_sockaddr_t *addr, int *bucketp) {
1626         dns_adbentry_t *entry;
1627         int bucket;
1628
1629         bucket = isc_sockaddr_hash(addr, ISC_TRUE) % NBUCKETS;
1630
1631         if (*bucketp == DNS_ADB_INVALIDBUCKET) {
1632                 LOCK(&adb->entrylocks[bucket]);
1633                 *bucketp = bucket;
1634         } else if (*bucketp != bucket) {
1635                 UNLOCK(&adb->entrylocks[*bucketp]);
1636                 LOCK(&adb->entrylocks[bucket]);
1637                 *bucketp = bucket;
1638         }
1639
1640         entry = ISC_LIST_HEAD(adb->entries[bucket]);
1641         while (entry != NULL) {
1642                 if (isc_sockaddr_equal(addr, &entry->sockaddr))
1643                         return (entry);
1644                 entry = ISC_LIST_NEXT(entry, plink);
1645         }
1646
1647         return (NULL);
1648 }
1649
1650 /*
1651  * Entry bucket MUST be locked!
1652  */
1653 static isc_boolean_t
1654 entry_is_lame(dns_adb_t *adb, dns_adbentry_t *entry, dns_name_t *qname,
1655               dns_rdatatype_t qtype, isc_stdtime_t now)
1656 {
1657         dns_adblameinfo_t *li, *next_li;
1658         isc_boolean_t is_bad;
1659
1660         is_bad = ISC_FALSE;
1661
1662         li = ISC_LIST_HEAD(entry->lameinfo);
1663         if (li == NULL)
1664                 return (ISC_FALSE);
1665         while (li != NULL) {
1666                 next_li = ISC_LIST_NEXT(li, plink);
1667
1668                 /*
1669                  * Has the entry expired?
1670                  */
1671                 if (li->lame_timer < now) {
1672                         ISC_LIST_UNLINK(entry->lameinfo, li, plink);
1673                         free_adblameinfo(adb, &li);
1674                 }
1675
1676                 /*
1677                  * Order tests from least to most expensive.
1678                  *
1679                  * We do not break out of the main loop here as
1680                  * we use the loop for house keeping.
1681                  */
1682                 if (li != NULL && !is_bad && li->qtype == qtype &&
1683                     dns_name_equal(qname, &li->qname))
1684                         is_bad = ISC_TRUE;
1685
1686                 li = next_li;
1687         }
1688
1689         return (is_bad);
1690 }
1691
1692 static void
1693 copy_namehook_lists(dns_adb_t *adb, dns_adbfind_t *find, dns_name_t *qname,
1694                     dns_rdatatype_t qtype, dns_adbname_t *name,
1695                     isc_stdtime_t now)
1696 {
1697         dns_adbnamehook_t *namehook;
1698         dns_adbaddrinfo_t *addrinfo;
1699         dns_adbentry_t *entry;
1700         int bucket;
1701
1702         bucket = DNS_ADB_INVALIDBUCKET;
1703
1704         if (find->options & DNS_ADBFIND_INET) {
1705                 namehook = ISC_LIST_HEAD(name->v4);
1706                 while (namehook != NULL) {
1707                         entry = namehook->entry;
1708                         bucket = entry->lock_bucket;
1709                         LOCK(&adb->entrylocks[bucket]);
1710
1711                         if (!FIND_RETURNLAME(find)
1712                             && entry_is_lame(adb, entry, qname, qtype, now)) {
1713                                 find->options |= DNS_ADBFIND_LAMEPRUNED;
1714                                 goto nextv4;
1715                         }
1716                         addrinfo = new_adbaddrinfo(adb, entry, find->port);
1717                         if (addrinfo == NULL) {
1718                                 find->partial_result |= DNS_ADBFIND_INET;
1719                                 goto out;
1720                         }
1721                         /*
1722                          * Found a valid entry.  Add it to the find's list.
1723                          */
1724                         inc_entry_refcnt(adb, entry, ISC_FALSE);
1725                         ISC_LIST_APPEND(find->list, addrinfo, publink);
1726                         addrinfo = NULL;
1727                 nextv4:
1728                         UNLOCK(&adb->entrylocks[bucket]);
1729                         bucket = DNS_ADB_INVALIDBUCKET;
1730                         namehook = ISC_LIST_NEXT(namehook, plink);
1731                 }
1732         }
1733
1734         if (find->options & DNS_ADBFIND_INET6) {
1735                 namehook = ISC_LIST_HEAD(name->v6);
1736                 while (namehook != NULL) {
1737                         entry = namehook->entry;
1738                         bucket = entry->lock_bucket;
1739                         LOCK(&adb->entrylocks[bucket]);
1740
1741                         if (!FIND_RETURNLAME(find)
1742                             && entry_is_lame(adb, entry, qname, qtype, now)) {
1743                                 find->options |= DNS_ADBFIND_LAMEPRUNED;
1744                                 goto nextv6;
1745                         }
1746                         addrinfo = new_adbaddrinfo(adb, entry, find->port);
1747                         if (addrinfo == NULL) {
1748                                 find->partial_result |= DNS_ADBFIND_INET6;
1749                                 goto out;
1750                         }
1751                         /*
1752                          * Found a valid entry.  Add it to the find's list.
1753                          */
1754                         inc_entry_refcnt(adb, entry, ISC_FALSE);
1755                         ISC_LIST_APPEND(find->list, addrinfo, publink);
1756                         addrinfo = NULL;
1757                 nextv6:
1758                         UNLOCK(&adb->entrylocks[bucket]);
1759                         bucket = DNS_ADB_INVALIDBUCKET;
1760                         namehook = ISC_LIST_NEXT(namehook, plink);
1761                 }
1762         }
1763
1764  out:
1765         if (bucket != DNS_ADB_INVALIDBUCKET)
1766                 UNLOCK(&adb->entrylocks[bucket]);
1767 }
1768
1769 static void
1770 shutdown_task(isc_task_t *task, isc_event_t *ev) {
1771         dns_adb_t *adb;
1772
1773         UNUSED(task);
1774
1775         adb = ev->ev_arg;
1776         INSIST(DNS_ADB_VALID(adb));
1777
1778         /*
1779          * Wait for lock around check_exit() call to be released.
1780          */
1781         LOCK(&adb->lock);
1782         /*
1783          * Kill the timer, and then the ADB itself.  Note that this implies
1784          * that this task was the one scheduled to get timer events.  If
1785          * this is not true (and it is unfortunate there is no way to INSIST()
1786          * this) badness will occur.
1787          */
1788         isc_timer_detach(&adb->timer);
1789         UNLOCK(&adb->lock);
1790         isc_event_free(&ev);
1791         destroy(adb);
1792 }
1793
1794 /*
1795  * Name bucket must be locked; adb may be locked; no other locks held.
1796  */
1797 static isc_boolean_t
1798 check_expire_name(dns_adbname_t **namep, isc_stdtime_t now) {
1799         dns_adbname_t *name;
1800         isc_boolean_t result = ISC_FALSE;
1801
1802         INSIST(namep != NULL && DNS_ADBNAME_VALID(*namep));
1803         name = *namep;
1804
1805         if (NAME_HAS_V4(name) || NAME_HAS_V6(name))
1806                 return (result);
1807         if (NAME_FETCH(name))
1808                 return (result);
1809         if (!EXPIRE_OK(name->expire_v4, now))
1810                 return (result);
1811         if (!EXPIRE_OK(name->expire_v6, now))
1812                 return (result);
1813         if (!EXPIRE_OK(name->expire_target, now))
1814                 return (result);
1815
1816         /*
1817          * The name is empty.  Delete it.
1818          */
1819         result = kill_name(&name, DNS_EVENT_ADBEXPIRED);
1820         *namep = NULL;
1821
1822         /*
1823          * Our caller, or one of its callers, will be calling check_exit() at
1824          * some point, so we don't need to do it here.
1825          */
1826         return (result);
1827 }
1828
1829 /*
1830  * Entry bucket must be locked; adb may be locked; no other locks held.
1831  */
1832 static isc_boolean_t
1833 check_expire_entry(dns_adb_t *adb, dns_adbentry_t **entryp, isc_stdtime_t now)
1834 {
1835         dns_adbentry_t *entry;
1836         isc_boolean_t expire;
1837         isc_boolean_t result = ISC_FALSE;
1838
1839         INSIST(entryp != NULL && DNS_ADBENTRY_VALID(*entryp));
1840         entry = *entryp;
1841
1842         if (entry->refcnt != 0)
1843                 return (result);
1844
1845         if (adb->overmem) {
1846                 isc_uint32_t val;
1847
1848                 isc_random_get(&val);
1849
1850                 expire = ISC_TF((val % 4) == 0);
1851         } else
1852                 expire = ISC_FALSE;
1853
1854         if (entry->expires == 0 || (! expire && entry->expires > now))
1855                 return (result);
1856
1857         /*
1858          * The entry is not in use.  Delete it.
1859          */
1860         DP(DEF_LEVEL, "killing entry %p", entry);
1861         INSIST(ISC_LINK_LINKED(entry, plink));
1862         result = unlink_entry(adb, entry);
1863         free_adbentry(adb, &entry);
1864         if (result)
1865                 dec_adb_irefcnt(adb);
1866         *entryp = NULL;
1867         return (result);
1868 }
1869
1870 /*
1871  * ADB must be locked, and no other locks held.
1872  */
1873 static isc_boolean_t
1874 cleanup_names(dns_adb_t *adb, int bucket, isc_stdtime_t now) {
1875         dns_adbname_t *name;
1876         dns_adbname_t *next_name;
1877         isc_boolean_t result = ISC_FALSE;
1878
1879         DP(CLEAN_LEVEL, "cleaning name bucket %d", bucket);
1880
1881         LOCK(&adb->namelocks[bucket]);
1882         if (adb->name_sd[bucket]) {
1883                 UNLOCK(&adb->namelocks[bucket]);
1884                 return (result);
1885         }
1886
1887         name = ISC_LIST_HEAD(adb->names[bucket]);
1888         while (name != NULL) {
1889                 next_name = ISC_LIST_NEXT(name, plink);
1890                 INSIST(result == ISC_FALSE);
1891                 result = check_expire_namehooks(name, now, adb->overmem);
1892                 if (!result)
1893                         result = check_expire_name(&name, now);
1894                 name = next_name;
1895         }
1896         UNLOCK(&adb->namelocks[bucket]);
1897         return (result);
1898 }
1899
1900 /*
1901  * ADB must be locked, and no other locks held.
1902  */
1903 static isc_boolean_t
1904 cleanup_entries(dns_adb_t *adb, int bucket, isc_stdtime_t now) {
1905         dns_adbentry_t *entry, *next_entry;
1906         isc_boolean_t result = ISC_FALSE;
1907
1908         DP(CLEAN_LEVEL, "cleaning entry bucket %d", bucket);
1909
1910         LOCK(&adb->entrylocks[bucket]);
1911         entry = ISC_LIST_HEAD(adb->entries[bucket]);
1912         while (entry != NULL) {
1913                 next_entry = ISC_LIST_NEXT(entry, plink);
1914                 INSIST(result == ISC_FALSE);
1915                 result = check_expire_entry(adb, &entry, now);
1916                 entry = next_entry;
1917         }
1918         UNLOCK(&adb->entrylocks[bucket]);
1919         return (result);
1920 }
1921
1922 static void
1923 timer_cleanup(isc_task_t *task, isc_event_t *ev) {
1924         dns_adb_t *adb;
1925         isc_stdtime_t now;
1926         unsigned int i;
1927         isc_interval_t interval;
1928
1929         UNUSED(task);
1930
1931         adb = ev->ev_arg;
1932         INSIST(DNS_ADB_VALID(adb));
1933
1934         LOCK(&adb->lock);
1935
1936         isc_stdtime_get(&now);
1937
1938         for (i = 0; i < CLEAN_BUCKETS; i++) {
1939                 /*
1940                  * Call our cleanup routines.
1941                  */
1942                 RUNTIME_CHECK(cleanup_names(adb, adb->next_cleanbucket, now) ==
1943                               ISC_FALSE);
1944                 RUNTIME_CHECK(cleanup_entries(adb, adb->next_cleanbucket, now)
1945                               == ISC_FALSE);
1946
1947                 /*
1948                  * Set the next bucket to be cleaned.
1949                  */
1950                 adb->next_cleanbucket++;
1951                 if (adb->next_cleanbucket >= NBUCKETS) {
1952                         adb->next_cleanbucket = 0;
1953 #ifdef DUMP_ADB_AFTER_CLEANING
1954                         dump_adb(adb, stdout, ISC_TRUE, now);
1955 #endif
1956                 }
1957         }
1958
1959         /*
1960          * Reset the timer.
1961          * XXXDCL isc_timer_reset might return ISC_R_UNEXPECTED or
1962          * ISC_R_NOMEMORY, but it isn't clear what could be done here
1963          * if either one of those things happened.
1964          */
1965         interval = adb->tick_interval;
1966         if (adb->overmem)
1967                 isc_interval_set(&interval, 0, 1);
1968         (void)isc_timer_reset(adb->timer, isc_timertype_once, NULL,
1969                               &interval, ISC_FALSE);
1970
1971         UNLOCK(&adb->lock);
1972
1973         isc_event_free(&ev);
1974 }
1975
1976 static void
1977 destroy(dns_adb_t *adb) {
1978         adb->magic = 0;
1979
1980         /*
1981          * The timer is already dead, from the task's shutdown callback.
1982          */
1983         isc_task_detach(&adb->task);
1984
1985         isc_mempool_destroy(&adb->nmp);
1986         isc_mempool_destroy(&adb->nhmp);
1987         isc_mempool_destroy(&adb->limp);
1988         isc_mempool_destroy(&adb->emp);
1989         isc_mempool_destroy(&adb->ahmp);
1990         isc_mempool_destroy(&adb->aimp);
1991         isc_mempool_destroy(&adb->afmp);
1992
1993         DESTROYMUTEXBLOCK(adb->entrylocks, NBUCKETS);
1994         DESTROYMUTEXBLOCK(adb->namelocks, NBUCKETS);
1995
1996         DESTROYLOCK(&adb->reflock);
1997         DESTROYLOCK(&adb->lock);
1998         DESTROYLOCK(&adb->mplock);
1999         DESTROYLOCK(&adb->overmemlock);
2000
2001         isc_mem_putanddetach(&adb->mctx, adb, sizeof(dns_adb_t));
2002 }
2003
2004
2005 /*
2006  * Public functions.
2007  */
2008
2009 isc_result_t
2010 dns_adb_create(isc_mem_t *mem, dns_view_t *view, isc_timermgr_t *timermgr,
2011                isc_taskmgr_t *taskmgr, dns_adb_t **newadb)
2012 {
2013         dns_adb_t *adb;
2014         isc_result_t result;
2015         int i;
2016
2017         REQUIRE(mem != NULL);
2018         REQUIRE(view != NULL);
2019         REQUIRE(timermgr != NULL);
2020         REQUIRE(taskmgr != NULL);
2021         REQUIRE(newadb != NULL && *newadb == NULL);
2022
2023         adb = isc_mem_get(mem, sizeof(dns_adb_t));
2024         if (adb == NULL)
2025                 return (ISC_R_NOMEMORY);
2026
2027         /*
2028          * Initialize things here that cannot fail, and especially things
2029          * that must be NULL for the error return to work properly.
2030          */
2031         adb->magic = 0;
2032         adb->erefcnt = 1;
2033         adb->irefcnt = 0;
2034         adb->nmp = NULL;
2035         adb->nhmp = NULL;
2036         adb->limp = NULL;
2037         adb->emp = NULL;
2038         adb->ahmp = NULL;
2039         adb->aimp = NULL;
2040         adb->afmp = NULL;
2041         adb->task = NULL;
2042         adb->timer = NULL;
2043         adb->mctx = NULL;
2044         adb->view = view;
2045         adb->timermgr = timermgr;
2046         adb->taskmgr = taskmgr;
2047         adb->next_cleanbucket = 0;
2048         ISC_EVENT_INIT(&adb->cevent, sizeof(adb->cevent), 0, NULL,
2049                        DNS_EVENT_ADBCONTROL, shutdown_task, adb,
2050                        adb, NULL, NULL);
2051         adb->cevent_sent = ISC_FALSE;
2052         adb->shutting_down = ISC_FALSE;
2053         adb->overmem = ISC_FALSE;
2054         ISC_LIST_INIT(adb->whenshutdown);
2055
2056         isc_mem_attach(mem, &adb->mctx);
2057
2058         result = isc_mutex_init(&adb->lock);
2059         if (result != ISC_R_SUCCESS)
2060                 goto fail0b;
2061
2062         result = isc_mutex_init(&adb->mplock);
2063         if (result != ISC_R_SUCCESS)
2064                 goto fail0c;
2065
2066         result = isc_mutex_init(&adb->reflock);
2067         if (result != ISC_R_SUCCESS)
2068                 goto fail0d;
2069
2070         result = isc_mutex_init(&adb->overmemlock);
2071         if (result != ISC_R_SUCCESS)
2072                 goto fail0e;
2073
2074         /*
2075          * Initialize the bucket locks for names and elements.
2076          * May as well initialize the list heads, too.
2077          */
2078         result = isc_mutexblock_init(adb->namelocks, NBUCKETS);
2079         if (result != ISC_R_SUCCESS)
2080                 goto fail1;
2081         for (i = 0; i < NBUCKETS; i++) {
2082                 ISC_LIST_INIT(adb->names[i]);
2083                 adb->name_sd[i] = ISC_FALSE;
2084                 adb->name_refcnt[i] = 0;
2085                 adb->irefcnt++;
2086         }
2087         for (i = 0; i < NBUCKETS; i++) {
2088                 ISC_LIST_INIT(adb->entries[i]);
2089                 adb->entry_sd[i] = ISC_FALSE;
2090                 adb->entry_refcnt[i] = 0;
2091                 adb->irefcnt++;
2092         }
2093         result = isc_mutexblock_init(adb->entrylocks, NBUCKETS);
2094         if (result != ISC_R_SUCCESS)
2095                 goto fail2;
2096
2097         /*
2098          * Memory pools
2099          */
2100 #define MPINIT(t, p, n) do { \
2101         result = isc_mempool_create(mem, sizeof(t), &(p)); \
2102         if (result != ISC_R_SUCCESS) \
2103                 goto fail3; \
2104         isc_mempool_setfreemax((p), FREE_ITEMS); \
2105         isc_mempool_setfillcount((p), FILL_COUNT); \
2106         isc_mempool_setname((p), n); \
2107         isc_mempool_associatelock((p), &adb->mplock); \
2108 } while (0)
2109
2110         MPINIT(dns_adbname_t, adb->nmp, "adbname");
2111         MPINIT(dns_adbnamehook_t, adb->nhmp, "adbnamehook");
2112         MPINIT(dns_adblameinfo_t, adb->limp, "adblameinfo");
2113         MPINIT(dns_adbentry_t, adb->emp, "adbentry");
2114         MPINIT(dns_adbfind_t, adb->ahmp, "adbfind");
2115         MPINIT(dns_adbaddrinfo_t, adb->aimp, "adbaddrinfo");
2116         MPINIT(dns_adbfetch_t, adb->afmp, "adbfetch");
2117
2118 #undef MPINIT
2119
2120         /*
2121          * Allocate a timer and a task for our periodic cleanup.
2122          */
2123         result = isc_task_create(adb->taskmgr, 0, &adb->task);
2124         if (result != ISC_R_SUCCESS)
2125                 goto fail3;
2126         isc_task_setname(adb->task, "ADB", adb);
2127         /*
2128          * XXXMLG When this is changed to be a config file option,
2129          */
2130         isc_interval_set(&adb->tick_interval, CLEAN_SECONDS, 0);
2131         result = isc_timer_create(adb->timermgr, isc_timertype_once,
2132                                   NULL, &adb->tick_interval, adb->task,
2133                                   timer_cleanup, adb, &adb->timer);
2134         if (result != ISC_R_SUCCESS)
2135                 goto fail3;
2136
2137         DP(ISC_LOG_DEBUG(5), "cleaning interval for adb: "
2138            "%u buckets every %u seconds, %u buckets in system, %u cl.interval",
2139            CLEAN_BUCKETS, CLEAN_SECONDS, NBUCKETS, CLEAN_PERIOD);
2140
2141         /*
2142          * Normal return.
2143          */
2144         adb->magic = DNS_ADB_MAGIC;
2145         *newadb = adb;
2146         return (ISC_R_SUCCESS);
2147
2148  fail3:
2149         if (adb->task != NULL)
2150                 isc_task_detach(&adb->task);
2151         if (adb->timer != NULL)
2152                 isc_timer_detach(&adb->timer);
2153
2154         /* clean up entrylocks */
2155         DESTROYMUTEXBLOCK(adb->entrylocks, NBUCKETS);
2156
2157  fail2: /* clean up namelocks */
2158         DESTROYMUTEXBLOCK(adb->namelocks, NBUCKETS);
2159
2160  fail1: /* clean up only allocated memory */
2161         if (adb->nmp != NULL)
2162                 isc_mempool_destroy(&adb->nmp);
2163         if (adb->nhmp != NULL)
2164                 isc_mempool_destroy(&adb->nhmp);
2165         if (adb->limp != NULL)
2166                 isc_mempool_destroy(&adb->limp);
2167         if (adb->emp != NULL)
2168                 isc_mempool_destroy(&adb->emp);
2169         if (adb->ahmp != NULL)
2170                 isc_mempool_destroy(&adb->ahmp);
2171         if (adb->aimp != NULL)
2172                 isc_mempool_destroy(&adb->aimp);
2173         if (adb->afmp != NULL)
2174                 isc_mempool_destroy(&adb->afmp);
2175
2176         DESTROYLOCK(&adb->overmemlock);
2177  fail0e:
2178         DESTROYLOCK(&adb->reflock);
2179  fail0d:
2180         DESTROYLOCK(&adb->mplock);
2181  fail0c:
2182         DESTROYLOCK(&adb->lock);
2183  fail0b:
2184         isc_mem_putanddetach(&adb->mctx, adb, sizeof(dns_adb_t));
2185
2186         return (result);
2187 }
2188
2189 void
2190 dns_adb_attach(dns_adb_t *adb, dns_adb_t **adbx) {
2191
2192         REQUIRE(DNS_ADB_VALID(adb));
2193         REQUIRE(adbx != NULL && *adbx == NULL);
2194
2195         inc_adb_erefcnt(adb);
2196         *adbx = adb;
2197 }
2198
2199 void
2200 dns_adb_detach(dns_adb_t **adbx) {
2201         dns_adb_t *adb;
2202         isc_boolean_t need_exit_check;
2203
2204         REQUIRE(adbx != NULL && DNS_ADB_VALID(*adbx));
2205
2206         adb = *adbx;
2207         *adbx = NULL;
2208
2209         INSIST(adb->erefcnt > 0);
2210
2211         LOCK(&adb->reflock);
2212         adb->erefcnt--;
2213         need_exit_check = ISC_TF(adb->erefcnt == 0 && adb->irefcnt == 0);
2214         UNLOCK(&adb->reflock);
2215
2216         if (need_exit_check) {
2217                 LOCK(&adb->lock);
2218                 INSIST(adb->shutting_down);
2219                 check_exit(adb);
2220                 UNLOCK(&adb->lock);
2221         }
2222 }
2223
2224 void
2225 dns_adb_whenshutdown(dns_adb_t *adb, isc_task_t *task, isc_event_t **eventp) {
2226         isc_task_t *clone;
2227         isc_event_t *event;
2228         isc_boolean_t zeroirefcnt = ISC_FALSE;
2229
2230         /*
2231          * Send '*eventp' to 'task' when 'adb' has shutdown.
2232          */
2233
2234         REQUIRE(DNS_ADB_VALID(adb));
2235         REQUIRE(eventp != NULL);
2236
2237         event = *eventp;
2238         *eventp = NULL;
2239
2240         LOCK(&adb->lock);
2241
2242         LOCK(&adb->reflock);
2243         zeroirefcnt = ISC_TF(adb->irefcnt == 0);
2244
2245         if (adb->shutting_down && zeroirefcnt &&
2246             isc_mempool_getallocated(adb->ahmp) == 0) {
2247                 /*
2248                  * We're already shutdown.  Send the event.
2249                  */
2250                 event->ev_sender = adb;
2251                 isc_task_send(task, &event);
2252         } else {
2253                 clone = NULL;
2254                 isc_task_attach(task, &clone);
2255                 event->ev_sender = clone;
2256                 ISC_LIST_APPEND(adb->whenshutdown, event, ev_link);
2257         }
2258
2259         UNLOCK(&adb->reflock);
2260         UNLOCK(&adb->lock);
2261 }
2262
2263 void
2264 dns_adb_shutdown(dns_adb_t *adb) {
2265         isc_boolean_t need_check_exit;
2266
2267         /*
2268          * Shutdown 'adb'.
2269          */
2270
2271         LOCK(&adb->lock);
2272
2273         if (!adb->shutting_down) {
2274                 adb->shutting_down = ISC_TRUE;
2275                 isc_mem_setwater(adb->mctx, water, adb, 0, 0);
2276                 need_check_exit = shutdown_names(adb);
2277                 if (!need_check_exit)
2278                         need_check_exit = shutdown_entries(adb);
2279                 if (need_check_exit)
2280                         check_exit(adb);
2281         }
2282
2283         UNLOCK(&adb->lock);
2284 }
2285
2286 isc_result_t
2287 dns_adb_createfind(dns_adb_t *adb, isc_task_t *task, isc_taskaction_t action,
2288                    void *arg, dns_name_t *name, dns_name_t *qname,
2289                    dns_rdatatype_t qtype, unsigned int options,
2290                    isc_stdtime_t now, dns_name_t *target,
2291                    in_port_t port, dns_adbfind_t **findp)
2292 {
2293         dns_adbfind_t *find;
2294         dns_adbname_t *adbname;
2295         int bucket;
2296         isc_boolean_t want_event, start_at_zone, alias, have_address;
2297         isc_result_t result;
2298         unsigned int wanted_addresses;
2299         unsigned int wanted_fetches;
2300         unsigned int query_pending;
2301
2302         REQUIRE(DNS_ADB_VALID(adb));
2303         if (task != NULL) {
2304                 REQUIRE(action != NULL);
2305         }
2306         REQUIRE(name != NULL);
2307         REQUIRE(qname != NULL);
2308         REQUIRE(findp != NULL && *findp == NULL);
2309         REQUIRE(target == NULL || dns_name_hasbuffer(target));
2310
2311         REQUIRE((options & DNS_ADBFIND_ADDRESSMASK) != 0);
2312
2313         result = ISC_R_UNEXPECTED;
2314         wanted_addresses = (options & DNS_ADBFIND_ADDRESSMASK);
2315         wanted_fetches = 0;
2316         query_pending = 0;
2317         want_event = ISC_FALSE;
2318         start_at_zone = ISC_FALSE;
2319         alias = ISC_FALSE;
2320
2321         if (now == 0)
2322                 isc_stdtime_get(&now);
2323
2324         /*
2325          * XXXMLG  Move this comment somewhere else!
2326          *
2327          * Look up the name in our internal database.
2328          *
2329          * Possibilities:  Note that these are not always exclusive.
2330          *
2331          *      No name found.  In this case, allocate a new name header and
2332          *      an initial namehook or two.  If any of these allocations
2333          *      fail, clean up and return ISC_R_NOMEMORY.
2334          *
2335          *      Name found, valid addresses present.  Allocate one addrinfo
2336          *      structure for each found and append it to the linked list
2337          *      of addresses for this header.
2338          *
2339          *      Name found, queries pending.  In this case, if a task was
2340          *      passed in, allocate a job id, attach it to the name's job
2341          *      list and remember to tell the caller that there will be
2342          *      more info coming later.
2343          */
2344
2345         find = new_adbfind(adb);
2346         if (find == NULL)
2347                 return (ISC_R_NOMEMORY);
2348
2349         find->port = port;
2350
2351         /*
2352          * Remember what types of addresses we are interested in.
2353          */
2354         find->options = options;
2355         find->flags |= wanted_addresses;
2356         if (FIND_WANTEVENT(find)) {
2357                 REQUIRE(task != NULL);
2358         }
2359
2360         /*
2361          * Try to see if we know anything about this name at all.
2362          */
2363         bucket = DNS_ADB_INVALIDBUCKET;
2364         adbname = find_name_and_lock(adb, name, find->options, &bucket);
2365         if (adb->name_sd[bucket]) {
2366                 DP(DEF_LEVEL,
2367                    "dns_adb_createfind: returning ISC_R_SHUTTINGDOWN");
2368                 RUNTIME_CHECK(free_adbfind(adb, &find) == ISC_FALSE);
2369                 result = ISC_R_SHUTTINGDOWN;
2370                 goto out;
2371         }
2372
2373         /*
2374          * Nothing found.  Allocate a new adbname structure for this name.
2375          */
2376         if (adbname == NULL) {
2377                 adbname = new_adbname(adb, name);
2378                 if (adbname == NULL) {
2379                         RUNTIME_CHECK(free_adbfind(adb, &find) == ISC_FALSE);
2380                         result = ISC_R_NOMEMORY;
2381                         goto out;
2382                 }
2383                 link_name(adb, bucket, adbname);
2384                 if (FIND_HINTOK(find))
2385                         adbname->flags |= NAME_HINT_OK;
2386                 if (FIND_GLUEOK(find))
2387                         adbname->flags |= NAME_GLUE_OK;
2388                 if (FIND_STARTATZONE(find))
2389                         adbname->flags |= NAME_STARTATZONE;
2390         }
2391
2392         /*
2393          * Expire old entries, etc.
2394          */
2395         RUNTIME_CHECK(check_expire_namehooks(adbname, now, adb->overmem) ==
2396                       ISC_FALSE);
2397
2398         /*
2399          * Do we know that the name is an alias?
2400          */
2401         if (!EXPIRE_OK(adbname->expire_target, now)) {
2402                 /*
2403                  * Yes, it is.
2404                  */
2405                 DP(DEF_LEVEL,
2406                    "dns_adb_createfind: name %p is an alias (cached)",
2407                    adbname);
2408                 alias = ISC_TRUE;
2409                 goto post_copy;
2410         }
2411
2412         /*
2413          * Try to populate the name from the database and/or
2414          * start fetches.  First try looking for an A record
2415          * in the database.
2416          */
2417         if (!NAME_HAS_V4(adbname) && EXPIRE_OK(adbname->expire_v4, now)
2418             && WANT_INET(wanted_addresses)) {
2419                 result = dbfind_name(adbname, now, dns_rdatatype_a);
2420                 if (result == ISC_R_SUCCESS) {
2421                         DP(DEF_LEVEL,
2422                            "dns_adb_createfind: found A for name %p in db",
2423                            adbname);
2424                         goto v6;
2425                 }
2426
2427                 /*
2428                  * Did we get a CNAME or DNAME?
2429                  */
2430                 if (result == DNS_R_ALIAS) {
2431                         DP(DEF_LEVEL,
2432                            "dns_adb_createfind: name %p is an alias",
2433                            adbname);
2434                         alias = ISC_TRUE;
2435                         goto post_copy;
2436                 }
2437
2438                 /*
2439                  * If the name doesn't exist at all, don't bother with
2440                  * v6 queries; they won't work.
2441                  *
2442                  * If the name does exist but we didn't get our data, go
2443                  * ahead and try AAAA.
2444                  *
2445                  * If the result is neither of these, try a fetch for A.
2446                  */
2447                 if (NXDOMAIN_RESULT(result))
2448                         goto fetch;
2449                 else if (NXRRSET_RESULT(result))
2450                         goto v6;
2451
2452                 if (!NAME_FETCH_V4(adbname))
2453                         wanted_fetches |= DNS_ADBFIND_INET;
2454         }
2455
2456  v6:
2457         if (!NAME_HAS_V6(adbname) && EXPIRE_OK(adbname->expire_v6, now)
2458             && WANT_INET6(wanted_addresses)) {
2459                 result = dbfind_name(adbname, now, dns_rdatatype_aaaa);
2460                 if (result == ISC_R_SUCCESS) {
2461                         DP(DEF_LEVEL,
2462                            "dns_adb_createfind: found AAAA for name %p",
2463                            adbname);
2464                         goto fetch;
2465                 }
2466
2467                 /*
2468                  * Did we get a CNAME or DNAME?
2469                  */
2470                 if (result == DNS_R_ALIAS) {
2471                         DP(DEF_LEVEL,
2472                            "dns_adb_createfind: name %p is an alias",
2473                            adbname);
2474                         alias = ISC_TRUE;
2475                         goto post_copy;
2476                 }
2477
2478                 /*
2479                  * Listen to negative cache hints, and don't start
2480                  * another query.
2481                  */
2482                 if (NCACHE_RESULT(result) || AUTH_NX(result))
2483                         goto fetch;
2484
2485                 if (!NAME_FETCH_V6(adbname))
2486                         wanted_fetches |= DNS_ADBFIND_INET6;
2487         }
2488
2489  fetch:
2490         if ((WANT_INET(wanted_addresses) && NAME_HAS_V4(adbname)) ||
2491             (WANT_INET6(wanted_addresses) && NAME_HAS_V6(adbname)))
2492                 have_address = ISC_TRUE;
2493         else
2494                 have_address = ISC_FALSE;
2495         if (wanted_fetches != 0 &&
2496             ! (FIND_AVOIDFETCHES(find) && have_address)) {
2497                 /*
2498                  * We're missing at least one address family.  Either the
2499                  * caller hasn't instructed us to avoid fetches, or we don't
2500                  * know anything about any of the address families that would
2501                  * be acceptable so we have to launch fetches.
2502                  */
2503
2504                 if (FIND_STARTATZONE(find))
2505                         start_at_zone = ISC_TRUE;
2506
2507                 /*
2508                  * Start V4.
2509                  */
2510                 if (WANT_INET(wanted_fetches) &&
2511                     fetch_name(adbname, start_at_zone,
2512                                dns_rdatatype_a) == ISC_R_SUCCESS) {
2513                         DP(DEF_LEVEL,
2514                            "dns_adb_createfind: started A fetch for name %p",
2515                            adbname);
2516                 }
2517
2518                 /*
2519                  * Start V6.
2520                  */
2521                 if (WANT_INET6(wanted_fetches) &&
2522                     fetch_name(adbname, start_at_zone,
2523                                dns_rdatatype_aaaa) == ISC_R_SUCCESS) {
2524                         DP(DEF_LEVEL,
2525                            "dns_adb_createfind: "
2526                            "started AAAA fetch for name %p",
2527                            adbname);
2528                 }
2529         }
2530
2531         /*
2532          * Run through the name and copy out the bits we are
2533          * interested in.
2534          */
2535         copy_namehook_lists(adb, find, qname, qtype, adbname, now);
2536
2537  post_copy:
2538         if (NAME_FETCH_V4(adbname))
2539                 query_pending |= DNS_ADBFIND_INET;
2540         if (NAME_FETCH_V6(adbname))
2541                 query_pending |= DNS_ADBFIND_INET6;
2542
2543         /*
2544          * Attach to the name's query list if there are queries
2545          * already running, and we have been asked to.
2546          */
2547         want_event = ISC_TRUE;
2548         if (!FIND_WANTEVENT(find))
2549                 want_event = ISC_FALSE;
2550         if (FIND_WANTEMPTYEVENT(find) && FIND_HAS_ADDRS(find))
2551                 want_event = ISC_FALSE;
2552         if ((wanted_addresses & query_pending) == 0)
2553                 want_event = ISC_FALSE;
2554         if (alias)
2555                 want_event = ISC_FALSE;
2556         if (want_event) {
2557                 find->adbname = adbname;
2558                 find->name_bucket = bucket;
2559                 ISC_LIST_APPEND(adbname->finds, find, plink);
2560                 find->query_pending = (query_pending & wanted_addresses);
2561                 find->flags &= ~DNS_ADBFIND_ADDRESSMASK;
2562                 find->flags |= (find->query_pending & DNS_ADBFIND_ADDRESSMASK);
2563                 DP(DEF_LEVEL, "createfind: attaching find %p to adbname %p",
2564                    find, adbname);
2565         } else {
2566                 /*
2567                  * Remove the flag so the caller knows there will never
2568                  * be an event, and set internal flags to fake that
2569                  * the event was sent and freed, so dns_adb_destroyfind() will
2570                  * do the right thing.
2571                  */
2572                 find->query_pending = (query_pending & wanted_addresses);
2573                 find->options &= ~DNS_ADBFIND_WANTEVENT;
2574                 find->flags |= (FIND_EVENT_SENT | FIND_EVENT_FREED);
2575                 find->flags &= ~DNS_ADBFIND_ADDRESSMASK;
2576         }
2577
2578         find->partial_result |= (adbname->partial_result & wanted_addresses);
2579         if (alias) {
2580                 if (target != NULL) {
2581                         result = dns_name_copy(&adbname->target, target, NULL);
2582                         if (result != ISC_R_SUCCESS)
2583                                 goto out;
2584                 }
2585                 result = DNS_R_ALIAS;
2586         } else
2587                 result = ISC_R_SUCCESS;
2588
2589         /*
2590          * Copy out error flags from the name structure into the find.
2591          */
2592         find->result_v4 = find_err_map[adbname->fetch_err];
2593         find->result_v6 = find_err_map[adbname->fetch6_err];
2594
2595  out:
2596         if (find != NULL) {
2597                 *findp = find;
2598
2599                 if (want_event) {
2600                         isc_task_t *taskp;
2601
2602                         INSIST((find->flags & DNS_ADBFIND_ADDRESSMASK) != 0);
2603                         taskp = NULL;
2604                         isc_task_attach(task, &taskp);
2605                         find->event.ev_sender = taskp;
2606                         find->event.ev_action = action;
2607                         find->event.ev_arg = arg;
2608                 }
2609         }
2610
2611         UNLOCK(&adb->namelocks[bucket]);
2612
2613         return (result);
2614 }
2615
2616 void
2617 dns_adb_destroyfind(dns_adbfind_t **findp) {
2618         dns_adbfind_t *find;
2619         dns_adbentry_t *entry;
2620         dns_adbaddrinfo_t *ai;
2621         int bucket;
2622         dns_adb_t *adb;
2623
2624         REQUIRE(findp != NULL && DNS_ADBFIND_VALID(*findp));
2625         find = *findp;
2626         *findp = NULL;
2627
2628         LOCK(&find->lock);
2629
2630         DP(DEF_LEVEL, "dns_adb_destroyfind on find %p", find);
2631
2632         adb = find->adb;
2633         REQUIRE(DNS_ADB_VALID(adb));
2634
2635         REQUIRE(FIND_EVENTFREED(find));
2636
2637         bucket = find->name_bucket;
2638         INSIST(bucket == DNS_ADB_INVALIDBUCKET);
2639
2640         UNLOCK(&find->lock);
2641
2642         /*
2643          * The find doesn't exist on any list, and nothing is locked.
2644          * Return the find to the memory pool, and decrement the adb's
2645          * reference count.
2646          */
2647         ai = ISC_LIST_HEAD(find->list);
2648         while (ai != NULL) {
2649                 ISC_LIST_UNLINK(find->list, ai, publink);
2650                 entry = ai->entry;
2651                 ai->entry = NULL;
2652                 INSIST(DNS_ADBENTRY_VALID(entry));
2653                 RUNTIME_CHECK(dec_entry_refcnt(adb, entry, ISC_TRUE) ==
2654                               ISC_FALSE);
2655                 free_adbaddrinfo(adb, &ai);
2656                 ai = ISC_LIST_HEAD(find->list);
2657         }
2658
2659         /*
2660          * WARNING:  The find is freed with the adb locked.  This is done
2661          * to avoid a race condition where we free the find, some other
2662          * thread tests to see if it should be destroyed, detects it should
2663          * be, destroys it, and then we try to lock it for our check, but the
2664          * lock is destroyed.
2665          */
2666         LOCK(&adb->lock);
2667         if (free_adbfind(adb, &find))
2668                 check_exit(adb);
2669         UNLOCK(&adb->lock);
2670 }
2671
2672 void
2673 dns_adb_cancelfind(dns_adbfind_t *find) {
2674         isc_event_t *ev;
2675         isc_task_t *task;
2676         dns_adb_t *adb;
2677         int bucket;
2678         int unlock_bucket;
2679
2680         LOCK(&find->lock);
2681
2682         DP(DEF_LEVEL, "dns_adb_cancelfind on find %p", find);
2683
2684         adb = find->adb;
2685         REQUIRE(DNS_ADB_VALID(adb));
2686
2687         REQUIRE(!FIND_EVENTFREED(find));
2688         REQUIRE(FIND_WANTEVENT(find));
2689
2690         bucket = find->name_bucket;
2691         if (bucket == DNS_ADB_INVALIDBUCKET)
2692                 goto cleanup;
2693
2694         /*
2695          * We need to get the adbname's lock to unlink the find.
2696          */
2697         unlock_bucket = bucket;
2698         violate_locking_hierarchy(&find->lock, &adb->namelocks[unlock_bucket]);
2699         bucket = find->name_bucket;
2700         if (bucket != DNS_ADB_INVALIDBUCKET) {
2701                 ISC_LIST_UNLINK(find->adbname->finds, find, plink);
2702                 find->adbname = NULL;
2703                 find->name_bucket = DNS_ADB_INVALIDBUCKET;
2704         }
2705         UNLOCK(&adb->namelocks[unlock_bucket]);
2706         bucket = DNS_ADB_INVALIDBUCKET;
2707
2708  cleanup:
2709
2710         if (!FIND_EVENTSENT(find)) {
2711                 ev = &find->event;
2712                 task = ev->ev_sender;
2713                 ev->ev_sender = find;
2714                 ev->ev_type = DNS_EVENT_ADBCANCELED;
2715                 ev->ev_destroy = event_free;
2716                 ev->ev_destroy_arg = find;
2717                 find->result_v4 = ISC_R_CANCELED;
2718                 find->result_v6 = ISC_R_CANCELED;
2719
2720                 DP(DEF_LEVEL, "sending event %p to task %p for find %p",
2721                    ev, task, find);
2722
2723                 isc_task_sendanddetach(&task, (isc_event_t **)&ev);
2724         }
2725
2726         UNLOCK(&find->lock);
2727 }
2728
2729 void
2730 dns_adb_dump(dns_adb_t *adb, FILE *f) {
2731         int i;
2732         isc_stdtime_t now;
2733
2734         REQUIRE(DNS_ADB_VALID(adb));
2735         REQUIRE(f != NULL);
2736
2737         /*
2738          * Lock the adb itself, lock all the name buckets, then lock all
2739          * the entry buckets.  This should put the adb into a state where
2740          * nothing can change, so we can iterate through everything and
2741          * print at our leisure.
2742          */
2743
2744         LOCK(&adb->lock);
2745         isc_stdtime_get(&now);
2746
2747         for (i = 0; i < NBUCKETS; i++)
2748                 RUNTIME_CHECK(cleanup_names(adb, i, now) == ISC_FALSE);
2749         for (i = 0; i < NBUCKETS; i++)
2750                 RUNTIME_CHECK(cleanup_entries(adb, i, now) == ISC_FALSE);
2751
2752         dump_adb(adb, f, ISC_FALSE, now);
2753         UNLOCK(&adb->lock);
2754 }
2755
2756 static void
2757 dump_ttl(FILE *f, const char *legend, isc_stdtime_t value, isc_stdtime_t now) {
2758         if (value == INT_MAX)
2759                 return;
2760         fprintf(f, " [%s TTL %d]", legend, value - now);
2761 }
2762
2763 static void
2764 dump_adb(dns_adb_t *adb, FILE *f, isc_boolean_t debug, isc_stdtime_t now) {
2765         int i;
2766         dns_adbname_t *name;
2767         dns_adbentry_t *entry;
2768
2769         fprintf(f, ";\n; Address database dump\n;\n");
2770         if (debug)
2771                 fprintf(f, "; addr %p, erefcnt %u, irefcnt %u, finds out %u\n",
2772                         adb, adb->erefcnt, adb->irefcnt,
2773                         isc_mempool_getallocated(adb->nhmp));
2774
2775         for (i = 0; i < NBUCKETS; i++)
2776                 LOCK(&adb->namelocks[i]);
2777         for (i = 0; i < NBUCKETS; i++)
2778                 LOCK(&adb->entrylocks[i]);
2779
2780         /*
2781          * Dump the names
2782          */
2783         for (i = 0; i < NBUCKETS; i++) {
2784                 name = ISC_LIST_HEAD(adb->names[i]);
2785                 if (name == NULL)
2786                         continue;
2787                 if (debug)
2788                         fprintf(f, "; bucket %d\n", i);
2789                 for (;
2790                      name != NULL;
2791                      name = ISC_LIST_NEXT(name, plink))
2792                 {
2793                         if (debug)
2794                                 fprintf(f, "; name %p (flags %08x)\n",
2795                                         name, name->flags);
2796
2797                         fprintf(f, "; ");
2798                         print_dns_name(f, &name->name);
2799                         if (dns_name_countlabels(&name->target) > 0) {
2800                                 fprintf(f, " alias ");
2801                                 print_dns_name(f, &name->target);
2802                         }
2803
2804                         dump_ttl(f, "v4", name->expire_v4, now);
2805                         dump_ttl(f, "v6", name->expire_v6, now);
2806                         dump_ttl(f, "target", name->expire_target, now);
2807
2808                         fprintf(f, " [v4 %s] [v6 %s]",
2809                                 errnames[name->fetch_err],
2810                                 errnames[name->fetch6_err]);
2811
2812                         fprintf(f, "\n");
2813
2814                         print_namehook_list(f, "v4", &name->v4, debug, now);
2815                         print_namehook_list(f, "v6", &name->v6, debug, now);
2816
2817                         if (debug)
2818                                 print_fetch_list(f, name);
2819                         if (debug)
2820                                 print_find_list(f, name);
2821
2822                 }
2823         }
2824
2825         fprintf(f, ";\n; Unassociated entries\n;\n");
2826
2827         for (i = 0; i < NBUCKETS; i++) {
2828                 entry = ISC_LIST_HEAD(adb->entries[i]);
2829                 while (entry != NULL) {
2830                         if (entry->refcnt == 0)
2831                                 dump_entry(f, entry, debug, now);
2832                         entry = ISC_LIST_NEXT(entry, plink);
2833                 }
2834         }
2835
2836         /*
2837          * Unlock everything
2838          */
2839         for (i = 0; i < NBUCKETS; i++)
2840                 UNLOCK(&adb->entrylocks[i]);
2841         for (i = 0; i < NBUCKETS; i++)
2842                 UNLOCK(&adb->namelocks[i]);
2843 }
2844
2845 static void
2846 dump_entry(FILE *f, dns_adbentry_t *entry, isc_boolean_t debug,
2847            isc_stdtime_t now)
2848 {
2849         char addrbuf[ISC_NETADDR_FORMATSIZE];
2850         char typebuf[DNS_RDATATYPE_FORMATSIZE];
2851         isc_netaddr_t netaddr;
2852         dns_adblameinfo_t *li;
2853
2854         isc_netaddr_fromsockaddr(&netaddr, &entry->sockaddr);
2855         isc_netaddr_format(&netaddr, addrbuf, sizeof(addrbuf));
2856
2857         if (debug)
2858                 fprintf(f, ";\t%p: refcnt %u\n", entry, entry->refcnt);
2859
2860         fprintf(f, ";\t%s [srtt %u] [flags %08x]",
2861                 addrbuf, entry->srtt, entry->flags);
2862         if (entry->expires != 0)
2863                 fprintf(f, " [ttl %d]", entry->expires - now);
2864         fprintf(f, "\n");
2865         for (li = ISC_LIST_HEAD(entry->lameinfo);
2866              li != NULL;
2867              li = ISC_LIST_NEXT(li, plink)) {
2868                 fprintf(f, ";\t\t");
2869                 print_dns_name(f, &li->qname);
2870                 dns_rdatatype_format(li->qtype, typebuf, sizeof(typebuf));
2871                 fprintf(f, " %s [lame TTL %d]\n", typebuf,
2872                         li->lame_timer - now);
2873         }
2874 }
2875
2876 void
2877 dns_adb_dumpfind(dns_adbfind_t *find, FILE *f) {
2878         char tmp[512];
2879         const char *tmpp;
2880         dns_adbaddrinfo_t *ai;
2881         isc_sockaddr_t *sa;
2882
2883         /*
2884          * Not used currently, in the API Just In Case we
2885          * want to dump out the name and/or entries too.
2886          */
2887
2888         LOCK(&find->lock);
2889
2890         fprintf(f, ";Find %p\n", find);
2891         fprintf(f, ";\tqpending %08x partial %08x options %08x flags %08x\n",
2892                 find->query_pending, find->partial_result,
2893                 find->options, find->flags);
2894         fprintf(f, ";\tname_bucket %d, name %p, event sender %p\n",
2895                 find->name_bucket, find->adbname, find->event.ev_sender);
2896
2897         ai = ISC_LIST_HEAD(find->list);
2898         if (ai != NULL)
2899                 fprintf(f, "\tAddresses:\n");
2900         while (ai != NULL) {
2901                 sa = &ai->sockaddr;
2902                 switch (sa->type.sa.sa_family) {
2903                 case AF_INET:
2904                         tmpp = inet_ntop(AF_INET, &sa->type.sin.sin_addr,
2905                                          tmp, sizeof(tmp));
2906                         break;
2907                 case AF_INET6:
2908                         tmpp = inet_ntop(AF_INET6, &sa->type.sin6.sin6_addr,
2909                                          tmp, sizeof(tmp));
2910                         break;
2911                 default:
2912                         tmpp = "UnkFamily";
2913                 }
2914
2915                 if (tmpp == NULL)
2916                         tmpp = "BadAddress";
2917
2918                 fprintf(f, "\t\tentry %p, flags %08x"
2919                         " srtt %u addr %s\n",
2920                         ai->entry, ai->flags, ai->srtt, tmpp);
2921
2922                 ai = ISC_LIST_NEXT(ai, publink);
2923         }
2924
2925         UNLOCK(&find->lock);
2926 }
2927
2928 static void
2929 print_dns_name(FILE *f, dns_name_t *name) {
2930         char buf[DNS_NAME_FORMATSIZE];
2931
2932         INSIST(f != NULL);
2933
2934         dns_name_format(name, buf, sizeof(buf));
2935         fprintf(f, "%s", buf);
2936 }
2937
2938 static void
2939 print_namehook_list(FILE *f, const char *legend, dns_adbnamehooklist_t *list,
2940                     isc_boolean_t debug, isc_stdtime_t now)
2941 {
2942         dns_adbnamehook_t *nh;
2943
2944         for (nh = ISC_LIST_HEAD(*list);
2945              nh != NULL;
2946              nh = ISC_LIST_NEXT(nh, plink))
2947         {
2948                 if (debug)
2949                         fprintf(f, ";\tHook(%s) %p\n", legend, nh);
2950                 dump_entry(f, nh->entry, debug, now);
2951         }
2952 }
2953
2954 static inline void
2955 print_fetch(FILE *f, dns_adbfetch_t *ft, const char *type) {
2956         fprintf(f, "\t\tFetch(%s): %p -> { nh %p, entry %p, fetch %p }\n",
2957                 type, ft, ft->namehook, ft->entry, ft->fetch);
2958 }
2959
2960 static void
2961 print_fetch_list(FILE *f, dns_adbname_t *n) {
2962         if (NAME_FETCH_A(n))
2963                 print_fetch(f, n->fetch_a, "A");
2964         if (NAME_FETCH_AAAA(n))
2965                 print_fetch(f, n->fetch_aaaa, "AAAA");
2966 }
2967
2968 static void
2969 print_find_list(FILE *f, dns_adbname_t *name) {
2970         dns_adbfind_t *find;
2971
2972         find = ISC_LIST_HEAD(name->finds);
2973         while (find != NULL) {
2974                 dns_adb_dumpfind(find, f);
2975                 find = ISC_LIST_NEXT(find, plink);
2976         }
2977 }
2978
2979 static isc_result_t
2980 dbfind_name(dns_adbname_t *adbname, isc_stdtime_t now, dns_rdatatype_t rdtype)
2981 {
2982         isc_result_t result;
2983         dns_rdataset_t rdataset;
2984         dns_adb_t *adb;
2985         dns_fixedname_t foundname;
2986         dns_name_t *fname;
2987
2988         INSIST(DNS_ADBNAME_VALID(adbname));
2989         adb = adbname->adb;
2990         INSIST(DNS_ADB_VALID(adb));
2991         INSIST(rdtype == dns_rdatatype_a || rdtype == dns_rdatatype_aaaa);
2992
2993         dns_fixedname_init(&foundname);
2994         fname = dns_fixedname_name(&foundname);
2995         dns_rdataset_init(&rdataset);
2996
2997         if (rdtype == dns_rdatatype_a)
2998                 adbname->fetch_err = FIND_ERR_UNEXPECTED;
2999         else
3000                 adbname->fetch6_err = FIND_ERR_UNEXPECTED;
3001
3002         result = dns_view_find(adb->view, &adbname->name, rdtype, now,
3003                                NAME_GLUEOK(adbname) ? DNS_DBFIND_GLUEOK : 0,
3004                                ISC_TF(NAME_HINTOK(adbname)),
3005                                NULL, NULL, fname, &rdataset, NULL);
3006
3007         /* XXXVIX this switch statement is too sparse to gen a jump table. */
3008         switch (result) {
3009         case DNS_R_GLUE:
3010         case DNS_R_HINT:
3011         case ISC_R_SUCCESS:
3012                 /*
3013                  * Found in the database.  Even if we can't copy out
3014                  * any information, return success, or else a fetch
3015                  * will be made, which will only make things worse.
3016                  */
3017                 if (rdtype == dns_rdatatype_a)
3018                         adbname->fetch_err = FIND_ERR_SUCCESS;
3019                 else
3020                         adbname->fetch6_err = FIND_ERR_SUCCESS;
3021                 result = import_rdataset(adbname, &rdataset, now);
3022                 break;
3023         case DNS_R_NXDOMAIN:
3024         case DNS_R_NXRRSET:
3025                 /*
3026                  * We're authoritative and the data doesn't exist.
3027                  * Make up a negative cache entry so we don't ask again
3028                  * for a while.
3029                  *
3030                  * XXXRTH  What time should we use?  I'm putting in 30 seconds
3031                  * for now.
3032                  */
3033                 if (rdtype == dns_rdatatype_a) {
3034                         adbname->expire_v4 = now + 30;
3035                         DP(NCACHE_LEVEL,
3036                            "adb name %p: Caching auth negative entry for A",
3037                            adbname);
3038                         if (result == DNS_R_NXDOMAIN)
3039                                 adbname->fetch_err = FIND_ERR_NXDOMAIN;
3040                         else
3041                                 adbname->fetch_err = FIND_ERR_NXRRSET;
3042                 } else {
3043                         DP(NCACHE_LEVEL,
3044                            "adb name %p: Caching auth negative entry for AAAA",
3045                            adbname);
3046                         adbname->expire_v6 = now + 30;
3047                         if (result == DNS_R_NXDOMAIN)
3048                                 adbname->fetch6_err = FIND_ERR_NXDOMAIN;
3049                         else
3050                                 adbname->fetch6_err = FIND_ERR_NXRRSET;
3051                 }
3052                 break;
3053         case DNS_R_NCACHENXDOMAIN:
3054         case DNS_R_NCACHENXRRSET:
3055                 /*
3056                  * We found a negative cache entry.  Pull the TTL from it
3057                  * so we won't ask again for a while.
3058                  */
3059                 rdataset.ttl = ttlclamp(rdataset.ttl);
3060                 if (rdtype == dns_rdatatype_a) {
3061                         adbname->expire_v4 = rdataset.ttl + now;
3062                         if (result == DNS_R_NCACHENXDOMAIN)
3063                                 adbname->fetch_err = FIND_ERR_NXDOMAIN;
3064                         else
3065                                 adbname->fetch_err = FIND_ERR_NXRRSET;
3066                         DP(NCACHE_LEVEL,
3067                           "adb name %p: Caching negative entry for A (ttl %u)",
3068                            adbname, rdataset.ttl);
3069                 } else {
3070                         DP(NCACHE_LEVEL,
3071                        "adb name %p: Caching negative entry for AAAA (ttl %u)",
3072                            adbname, rdataset.ttl);
3073                         adbname->expire_v6 = rdataset.ttl + now;
3074                         if (result == DNS_R_NCACHENXDOMAIN)
3075                                 adbname->fetch6_err = FIND_ERR_NXDOMAIN;
3076                         else
3077                                 adbname->fetch6_err = FIND_ERR_NXRRSET;
3078                 }
3079                 break;
3080         case DNS_R_CNAME:
3081         case DNS_R_DNAME:
3082                 /*
3083                  * Clear the hint and glue flags, so this will match
3084                  * more often.
3085                  */
3086                 adbname->flags &= ~(DNS_ADBFIND_GLUEOK | DNS_ADBFIND_HINTOK);
3087
3088                 rdataset.ttl = ttlclamp(rdataset.ttl);
3089                 clean_target(adb, &adbname->target);
3090                 adbname->expire_target = INT_MAX;
3091                 result = set_target(adb, &adbname->name, fname, &rdataset,
3092                                     &adbname->target);
3093                 if (result == ISC_R_SUCCESS) {
3094                         result = DNS_R_ALIAS;
3095                         DP(NCACHE_LEVEL,
3096                            "adb name %p: caching alias target",
3097                            adbname);
3098                         adbname->expire_target = rdataset.ttl + now;
3099                 }
3100                 if (rdtype == dns_rdatatype_a)
3101                         adbname->fetch_err = FIND_ERR_SUCCESS;
3102                 else
3103                         adbname->fetch6_err = FIND_ERR_SUCCESS;
3104                 break;
3105         }
3106
3107         if (dns_rdataset_isassociated(&rdataset))
3108                 dns_rdataset_disassociate(&rdataset);
3109
3110         return (result);
3111 }
3112
3113 static void
3114 fetch_callback(isc_task_t *task, isc_event_t *ev) {
3115         dns_fetchevent_t *dev;
3116         dns_adbname_t *name;
3117         dns_adb_t *adb;
3118         dns_adbfetch_t *fetch;
3119         int bucket;
3120         isc_eventtype_t ev_status;
3121         isc_stdtime_t now;
3122         isc_result_t result;
3123         unsigned int address_type;
3124         isc_boolean_t want_check_exit = ISC_FALSE;
3125
3126         UNUSED(task);
3127
3128         INSIST(ev->ev_type == DNS_EVENT_FETCHDONE);
3129         dev = (dns_fetchevent_t *)ev;
3130         name = ev->ev_arg;
3131         INSIST(DNS_ADBNAME_VALID(name));
3132         adb = name->adb;
3133         INSIST(DNS_ADB_VALID(adb));
3134
3135         bucket = name->lock_bucket;
3136         LOCK(&adb->namelocks[bucket]);
3137
3138         INSIST(NAME_FETCH_A(name) || NAME_FETCH_AAAA(name));
3139         address_type = 0;
3140         if (NAME_FETCH_A(name) && (name->fetch_a->fetch == dev->fetch)) {
3141                 address_type = DNS_ADBFIND_INET;
3142                 fetch = name->fetch_a;
3143                 name->fetch_a = NULL;
3144         } else if (NAME_FETCH_AAAA(name)
3145                    && (name->fetch_aaaa->fetch == dev->fetch)) {
3146                 address_type = DNS_ADBFIND_INET6;
3147                 fetch = name->fetch_aaaa;
3148                 name->fetch_aaaa = NULL;
3149         } else
3150                 fetch = NULL;
3151
3152         INSIST(address_type != 0 && fetch != NULL);
3153
3154         dns_resolver_destroyfetch(&fetch->fetch);
3155         dev->fetch = NULL;
3156
3157         ev_status = DNS_EVENT_ADBNOMOREADDRESSES;
3158
3159         /*
3160          * Cleanup things we don't care about.
3161          */
3162         if (dev->node != NULL)
3163                 dns_db_detachnode(dev->db, &dev->node);
3164         if (dev->db != NULL)
3165                 dns_db_detach(&dev->db);
3166
3167         /*
3168          * If this name is marked as dead, clean up, throwing away
3169          * potentially good data.
3170          */
3171         if (NAME_DEAD(name)) {
3172                 free_adbfetch(adb, &fetch);
3173                 isc_event_free(&ev);
3174
3175                 want_check_exit = kill_name(&name, DNS_EVENT_ADBCANCELED);
3176
3177                 UNLOCK(&adb->namelocks[bucket]);
3178
3179                 if (want_check_exit) {
3180                         LOCK(&adb->lock);
3181                         check_exit(adb);
3182                         UNLOCK(&adb->lock);
3183                 }
3184
3185                 return;
3186         }
3187
3188         isc_stdtime_get(&now);
3189
3190         /*
3191          * If we got a negative cache response, remember it.
3192          */
3193         if (NCACHE_RESULT(dev->result)) {
3194                 dev->rdataset->ttl = ttlclamp(dev->rdataset->ttl);
3195                 if (address_type == DNS_ADBFIND_INET) {
3196                         DP(NCACHE_LEVEL, "adb fetch name %p: "
3197                            "caching negative entry for A (ttl %u)",
3198                            name, dev->rdataset->ttl);
3199                         name->expire_v4 = ISC_MIN(name->expire_v4,
3200                                                   dev->rdataset->ttl + now);
3201                         if (dev->result == DNS_R_NCACHENXDOMAIN)
3202                                 name->fetch_err = FIND_ERR_NXDOMAIN;
3203                         else
3204                                 name->fetch_err = FIND_ERR_NXRRSET;
3205                 } else {
3206                         DP(NCACHE_LEVEL, "adb fetch name %p: "
3207                            "caching negative entry for AAAA (ttl %u)",
3208                            name, dev->rdataset->ttl);
3209                         name->expire_v6 = ISC_MIN(name->expire_v6,
3210                                                   dev->rdataset->ttl + now);
3211                         if (dev->result == DNS_R_NCACHENXDOMAIN)
3212                                 name->fetch6_err = FIND_ERR_NXDOMAIN;
3213                         else
3214                                 name->fetch6_err = FIND_ERR_NXRRSET;
3215                 }
3216                 goto out;
3217         }
3218
3219         /*
3220          * Handle CNAME/DNAME.
3221          */
3222         if (dev->result == DNS_R_CNAME || dev->result == DNS_R_DNAME) {
3223                 dev->rdataset->ttl = ttlclamp(dev->rdataset->ttl);
3224                 clean_target(adb, &name->target);
3225                 name->expire_target = INT_MAX;
3226                 result = set_target(adb, &name->name,
3227                                     dns_fixedname_name(&dev->foundname),
3228                                     dev->rdataset,
3229                                     &name->target);
3230                 if (result == ISC_R_SUCCESS) {
3231                         DP(NCACHE_LEVEL,
3232                            "adb fetch name %p: caching alias target",
3233                            name);
3234                         name->expire_target = dev->rdataset->ttl + now;
3235                 }
3236                 goto check_result;
3237         }
3238
3239         /*
3240          * Did we get back junk?  If so, and there are no more fetches
3241          * sitting out there, tell all the finds about it.
3242          */
3243         if (dev->result != ISC_R_SUCCESS) {
3244                 char buf[DNS_NAME_FORMATSIZE];
3245
3246                 dns_name_format(&name->name, buf, sizeof(buf));
3247                 DP(DEF_LEVEL, "adb: fetch of '%s' %s failed: %s",
3248                    buf, address_type == DNS_ADBFIND_INET ? "A" : "AAAA",
3249                    dns_result_totext(dev->result));
3250                 /* XXXMLG Don't pound on bad servers. */
3251                 if (address_type == DNS_ADBFIND_INET) {
3252                         name->expire_v4 = ISC_MIN(name->expire_v4, now + 300);
3253                         name->fetch_err = FIND_ERR_FAILURE;
3254                 } else {
3255                         name->expire_v6 = ISC_MIN(name->expire_v6, now + 300);
3256                         name->fetch6_err = FIND_ERR_FAILURE;
3257                 }
3258                 goto out;
3259         }
3260
3261         /*
3262          * We got something potentially useful.
3263          */
3264         result = import_rdataset(name, &fetch->rdataset, now);
3265
3266  check_result:
3267         if (result == ISC_R_SUCCESS) {
3268                 ev_status = DNS_EVENT_ADBMOREADDRESSES;
3269                 if (address_type == DNS_ADBFIND_INET)
3270                         name->fetch_err = FIND_ERR_SUCCESS;
3271                 else
3272                         name->fetch6_err = FIND_ERR_SUCCESS;
3273         }
3274
3275  out:
3276         free_adbfetch(adb, &fetch);
3277         isc_event_free(&ev);
3278
3279         clean_finds_at_name(name, ev_status, address_type);
3280
3281         UNLOCK(&adb->namelocks[bucket]);
3282 }
3283
3284 static isc_result_t
3285 fetch_name(dns_adbname_t *adbname,
3286            isc_boolean_t start_at_zone,
3287            dns_rdatatype_t type)
3288 {
3289         isc_result_t result;
3290         dns_adbfetch_t *fetch = NULL;
3291         dns_adb_t *adb;
3292         dns_fixedname_t fixed;
3293         dns_name_t *name;
3294         dns_rdataset_t rdataset;
3295         dns_rdataset_t *nameservers;
3296         unsigned int options;
3297
3298         INSIST(DNS_ADBNAME_VALID(adbname));
3299         adb = adbname->adb;
3300         INSIST(DNS_ADB_VALID(adb));
3301
3302         INSIST((type == dns_rdatatype_a && !NAME_FETCH_V4(adbname)) ||
3303                (type == dns_rdatatype_aaaa && !NAME_FETCH_V6(adbname)));
3304
3305         adbname->fetch_err = FIND_ERR_NOTFOUND;
3306
3307         name = NULL;
3308         nameservers = NULL;
3309         dns_rdataset_init(&rdataset);
3310
3311         options = DNS_FETCHOPT_NOVALIDATE;
3312         if (start_at_zone) {
3313                 DP(ENTER_LEVEL,
3314                    "fetch_name: starting at zone for name %p",
3315                    adbname);
3316                 dns_fixedname_init(&fixed);
3317                 name = dns_fixedname_name(&fixed);
3318                 result = dns_view_findzonecut2(adb->view, &adbname->name, name,
3319                                                0, 0, ISC_TRUE, ISC_FALSE,
3320                                                &rdataset, NULL);
3321                 if (result != ISC_R_SUCCESS && result != DNS_R_HINT)
3322                         goto cleanup;
3323                 nameservers = &rdataset;
3324                 options |= DNS_FETCHOPT_UNSHARED;
3325         }
3326
3327         fetch = new_adbfetch(adb);
3328         if (fetch == NULL) {
3329                 result = ISC_R_NOMEMORY;
3330                 goto cleanup;
3331         }
3332
3333         result = dns_resolver_createfetch(adb->view->resolver, &adbname->name,
3334                                           type, name, nameservers, NULL,
3335                                           options, adb->task, fetch_callback,
3336                                           adbname, &fetch->rdataset, NULL,
3337                                           &fetch->fetch);
3338         if (result != ISC_R_SUCCESS)
3339                 goto cleanup;
3340
3341         if (type == dns_rdatatype_a)
3342                 adbname->fetch_a = fetch;
3343         else
3344                 adbname->fetch_aaaa = fetch;
3345         fetch = NULL;  /* Keep us from cleaning this up below. */
3346
3347  cleanup:
3348         if (fetch != NULL)
3349                 free_adbfetch(adb, &fetch);
3350         if (dns_rdataset_isassociated(&rdataset))
3351                 dns_rdataset_disassociate(&rdataset);
3352
3353         return (result);
3354 }
3355
3356 /*
3357  * XXXMLG Needs to take a find argument and an address info, no zone or adb,
3358  * since these can be extracted from the find itself.
3359  */
3360 isc_result_t
3361 dns_adb_marklame(dns_adb_t *adb, dns_adbaddrinfo_t *addr, dns_name_t *qname,
3362                  dns_rdatatype_t qtype, isc_stdtime_t expire_time)
3363 {
3364         dns_adblameinfo_t *li;
3365         int bucket;
3366         isc_result_t result = ISC_R_SUCCESS;
3367
3368         REQUIRE(DNS_ADB_VALID(adb));
3369         REQUIRE(DNS_ADBADDRINFO_VALID(addr));
3370         REQUIRE(qname != NULL);
3371
3372         bucket = addr->entry->lock_bucket;
3373         LOCK(&adb->entrylocks[bucket]);
3374         li = ISC_LIST_HEAD(addr->entry->lameinfo);
3375         while (li != NULL &&
3376                (li->qtype != qtype || !dns_name_equal(qname, &li->qname)))
3377                 li = ISC_LIST_NEXT(li, plink);
3378         if (li != NULL) {
3379                 if (expire_time > li->lame_timer)
3380                         li->lame_timer = expire_time;
3381                 goto unlock;
3382         }
3383         li = new_adblameinfo(adb, qname, qtype);
3384         if (li == NULL) {
3385                 result = ISC_R_NOMEMORY;
3386                 goto unlock;
3387         }
3388
3389         li->lame_timer = expire_time;
3390
3391         ISC_LIST_PREPEND(addr->entry->lameinfo, li, plink);
3392  unlock:
3393         UNLOCK(&adb->entrylocks[bucket]);
3394
3395         return (result);
3396 }
3397
3398 void
3399 dns_adb_adjustsrtt(dns_adb_t *adb, dns_adbaddrinfo_t *addr,
3400                    unsigned int rtt, unsigned int factor)
3401 {
3402         int bucket;
3403         unsigned int new_srtt;
3404         isc_stdtime_t now;
3405
3406         REQUIRE(DNS_ADB_VALID(adb));
3407         REQUIRE(DNS_ADBADDRINFO_VALID(addr));
3408         REQUIRE(factor <= 10);
3409
3410         bucket = addr->entry->lock_bucket;
3411         LOCK(&adb->entrylocks[bucket]);
3412
3413         if (factor == DNS_ADB_RTTADJAGE)
3414                 new_srtt = addr->entry->srtt * 98 / 100;
3415         else
3416                 new_srtt = (addr->entry->srtt / 10 * factor)
3417                         + (rtt / 10 * (10 - factor));
3418
3419         addr->entry->srtt = new_srtt;
3420         addr->srtt = new_srtt;
3421
3422         isc_stdtime_get(&now);
3423         addr->entry->expires = now + ADB_ENTRY_WINDOW;
3424
3425         UNLOCK(&adb->entrylocks[bucket]);
3426 }
3427
3428 void
3429 dns_adb_changeflags(dns_adb_t *adb, dns_adbaddrinfo_t *addr,
3430                     unsigned int bits, unsigned int mask)
3431 {
3432         int bucket;
3433
3434         REQUIRE(DNS_ADB_VALID(adb));
3435         REQUIRE(DNS_ADBADDRINFO_VALID(addr));
3436
3437         bucket = addr->entry->lock_bucket;
3438         LOCK(&adb->entrylocks[bucket]);
3439
3440         addr->entry->flags = (addr->entry->flags & ~mask) | (bits & mask);
3441         /*
3442          * Note that we do not update the other bits in addr->flags with
3443          * the most recent values from addr->entry->flags.
3444          */
3445         addr->flags = (addr->flags & ~mask) | (bits & mask);
3446
3447         UNLOCK(&adb->entrylocks[bucket]);
3448 }
3449
3450 isc_result_t
3451 dns_adb_findaddrinfo(dns_adb_t *adb, isc_sockaddr_t *sa,
3452                      dns_adbaddrinfo_t **addrp, isc_stdtime_t now)
3453 {
3454         int bucket;
3455         dns_adbentry_t *entry;
3456         dns_adbaddrinfo_t *addr;
3457         isc_result_t result;
3458         in_port_t port;
3459
3460         REQUIRE(DNS_ADB_VALID(adb));
3461         REQUIRE(addrp != NULL && *addrp == NULL);
3462
3463         UNUSED(now);
3464
3465         result = ISC_R_SUCCESS;
3466         bucket = DNS_ADB_INVALIDBUCKET;
3467         entry = find_entry_and_lock(adb, sa, &bucket);
3468         if (adb->entry_sd[bucket]) {
3469                 result = ISC_R_SHUTTINGDOWN;
3470                 goto unlock;
3471         }
3472         if (entry == NULL) {
3473                 /*
3474                  * We don't know anything about this address.
3475                  */
3476                 entry = new_adbentry(adb);
3477                 if (entry == NULL) {
3478                         result = ISC_R_NOMEMORY;
3479                         goto unlock;
3480                 }
3481                 entry->sockaddr = *sa;
3482                 link_entry(adb, bucket, entry);
3483                 DP(ENTER_LEVEL, "findaddrinfo: new entry %p", entry);
3484         } else
3485                 DP(ENTER_LEVEL, "findaddrinfo: found entry %p", entry);
3486
3487         port = isc_sockaddr_getport(sa);
3488         addr = new_adbaddrinfo(adb, entry, port);
3489         if (addr == NULL) {
3490                 result = ISC_R_NOMEMORY;
3491         } else {
3492                 inc_entry_refcnt(adb, entry, ISC_FALSE);
3493                 *addrp = addr;
3494         }
3495
3496  unlock:
3497         UNLOCK(&adb->entrylocks[bucket]);
3498
3499         return (result);
3500 }
3501
3502 void
3503 dns_adb_freeaddrinfo(dns_adb_t *adb, dns_adbaddrinfo_t **addrp) {
3504         dns_adbaddrinfo_t *addr;
3505         dns_adbentry_t *entry;
3506         int bucket;
3507         isc_stdtime_t now;
3508         isc_boolean_t want_check_exit = ISC_FALSE;
3509
3510         REQUIRE(DNS_ADB_VALID(adb));
3511         REQUIRE(addrp != NULL);
3512         addr = *addrp;
3513         REQUIRE(DNS_ADBADDRINFO_VALID(addr));
3514         entry = addr->entry;
3515         REQUIRE(DNS_ADBENTRY_VALID(entry));
3516
3517         isc_stdtime_get(&now);
3518
3519         *addrp = NULL;
3520
3521         bucket = addr->entry->lock_bucket;
3522         LOCK(&adb->entrylocks[bucket]);
3523
3524         entry->expires = now + ADB_ENTRY_WINDOW;
3525
3526         want_check_exit = dec_entry_refcnt(adb, entry, ISC_FALSE);
3527
3528         UNLOCK(&adb->entrylocks[bucket]);
3529
3530         addr->entry = NULL;
3531         free_adbaddrinfo(adb, &addr);
3532
3533         if (want_check_exit) {
3534                 LOCK(&adb->lock);
3535                 check_exit(adb);
3536                 UNLOCK(&adb->lock);
3537         }
3538 }
3539
3540 void
3541 dns_adb_flush(dns_adb_t *adb) {
3542         unsigned int i;
3543
3544         INSIST(DNS_ADB_VALID(adb));
3545
3546         LOCK(&adb->lock);
3547
3548         /*
3549          * Call our cleanup routines.
3550          */
3551         for (i = 0; i < NBUCKETS; i++)
3552                 RUNTIME_CHECK(cleanup_names(adb, i, INT_MAX) == ISC_FALSE);
3553         for (i = 0; i < NBUCKETS; i++)
3554                 RUNTIME_CHECK(cleanup_entries(adb, i, INT_MAX) == ISC_FALSE);
3555
3556 #ifdef DUMP_ADB_AFTER_CLEANING
3557         dump_adb(adb, stdout, ISC_TRUE, INT_MAX);
3558 #endif
3559
3560         UNLOCK(&adb->lock);
3561 }
3562
3563 void
3564 dns_adb_flushname(dns_adb_t *adb, dns_name_t *name) {
3565         dns_adbname_t *adbname;
3566         dns_adbname_t *nextname;
3567         int bucket;
3568
3569         INSIST(DNS_ADB_VALID(adb));
3570
3571         LOCK(&adb->lock);
3572         bucket = dns_name_hash(name, ISC_FALSE) % NBUCKETS;
3573         LOCK(&adb->namelocks[bucket]);
3574         adbname = ISC_LIST_HEAD(adb->names[bucket]);
3575         while (adbname != NULL) {
3576                 nextname = ISC_LIST_NEXT(adbname, plink);
3577                 if (!NAME_DEAD(adbname) &&
3578                     dns_name_equal(name, &adbname->name)) {
3579                         RUNTIME_CHECK(kill_name(&adbname,
3580                                                 DNS_EVENT_ADBCANCELED) ==
3581                                       ISC_FALSE);
3582                 }
3583                 adbname = nextname;
3584         }
3585         UNLOCK(&adb->namelocks[bucket]);
3586         UNLOCK(&adb->lock);
3587 }
3588
3589 static void
3590 water(void *arg, int mark) {
3591         dns_adb_t *adb = arg;
3592         isc_boolean_t overmem = ISC_TF(mark == ISC_MEM_HIWATER);
3593         isc_interval_t interval;
3594
3595         REQUIRE(DNS_ADB_VALID(adb));
3596
3597         DP(ISC_LOG_DEBUG(1),
3598            "adb reached %s water mark", overmem ? "high" : "low");
3599
3600         /*
3601          * We can't use adb->lock as there is potential for water
3602          * to be called when adb->lock is held.
3603          */
3604         LOCK(&adb->overmemlock);
3605         if (adb->overmem != overmem) {
3606                 adb->overmem = overmem;
3607                 if (overmem) {
3608                         isc_interval_set(&interval, 0, 1);
3609                         (void)isc_timer_reset(adb->timer, isc_timertype_once,
3610                                               NULL, &interval, ISC_TRUE);
3611                 }
3612                 isc_mem_waterack(adb->mctx, mark);
3613         }
3614         UNLOCK(&adb->overmemlock);
3615 }
3616
3617 void
3618 dns_adb_setadbsize(dns_adb_t *adb, isc_uint32_t size) {
3619         isc_uint32_t hiwater;
3620         isc_uint32_t lowater;
3621
3622         INSIST(DNS_ADB_VALID(adb));
3623
3624         if (size != 0 && size < DNS_ADB_MINADBSIZE)
3625                 size = DNS_ADB_MINADBSIZE;
3626
3627         hiwater = size - (size >> 3);   /* Approximately 7/8ths. */
3628         lowater = size - (size >> 2);   /* Approximately 3/4ths. */
3629
3630         if (size == 0 || hiwater == 0 || lowater == 0)
3631                 isc_mem_setwater(adb->mctx, water, adb, 0, 0);
3632         else
3633                 isc_mem_setwater(adb->mctx, water, adb, hiwater, lowater);
3634 }