sys/netpfil/ipfw/ip_fw_dynamic.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2017-2018 Yandex LLC
   5  * Copyright (c) 2017-2018 Andrey V. Elsukov <ae@FreeBSD.org>
   6  * Copyright (c) 2002 Luigi Rizzo, Universita` di Pisa
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #include <sys/cdefs.h>
  31 __FBSDID("$FreeBSD$");
  32
  33 #include "opt_inet.h"
  34 #include "opt_inet6.h"
  35 #include "opt_ipfw.h"
  36 #ifndef INET
  37 #error IPFIREWALL requires INET.
  38 #endif /* INET */
  39
  40 #include <sys/param.h>
  41 #include <sys/systm.h>
  42 #include <sys/hash.h>
  43 #include <sys/mbuf.h>
  44 #include <sys/kernel.h>
  45 #include <sys/lock.h>
  46 #include <sys/pcpu.h>
  47 #include <sys/queue.h>
  48 #include <sys/rmlock.h>
  49 #include <sys/smp.h>
  50 #include <sys/socket.h>
  51 #include <sys/sysctl.h>
  52 #include <sys/syslog.h>
  53 #include <net/ethernet.h>
  54 #include <net/if.h>
  55 #include <net/if_var.h>
  56 #include <net/pfil.h>
  57 #include <net/vnet.h>
  58
  59 #include <netinet/in.h>
  60 #include <netinet/ip.h>
  61 #include <netinet/ip_var.h>
  62 #include <netinet/ip_fw.h>
  63 #include <netinet/tcp_var.h>
  64 #include <netinet/udp.h>
  65
  66 #include <netinet/ip6.h>        /* IN6_ARE_ADDR_EQUAL */
  67 #ifdef INET6
  68 #include <netinet6/in6_var.h>
  69 #include <netinet6/ip6_var.h>
  70 #include <netinet6/scope6_var.h>
  71 #endif
  72
  73 #include <netpfil/ipfw/ip_fw_private.h>
  74
  75 #include <machine/in_cksum.h>   /* XXX for in_cksum */
  76
  77 #ifdef MAC
  78 #include <security/mac/mac_framework.h>
  79 #endif
  80
  81 /*
  82  * Description of dynamic states.
  83  *
  84  * Dynamic states are stored in lists accessed through a hash tables
  85  * whose size is curr_dyn_buckets. This value can be modified through
  86  * the sysctl variable dyn_buckets.
  87  *
  88  * Currently there are four tables: dyn_ipv4, dyn_ipv6, dyn_ipv4_parent,
  89  * and dyn_ipv6_parent.
  90  *
  91  * When a packet is received, its address fields hashed, then matched
  92  * against the entries in the corresponding list by addr_type.
  93  * Dynamic states can be used for different purposes:
  94  *  + stateful rules;
  95  *  + enforcing limits on the number of sessions;
  96  *  + in-kernel NAT (not implemented yet)
  97  *
  98  * The lifetime of dynamic states is regulated by dyn_*_lifetime,
  99  * measured in seconds and depending on the flags.
 100  *
 101  * The total number of dynamic states is equal to UMA zone items count.
 102  * The max number of dynamic states is dyn_max. When we reach
 103  * the maximum number of rules we do not create anymore. This is
 104  * done to avoid consuming too much memory, but also too much
 105  * time when searching on each packet (ideally, we should try instead
 106  * to put a limit on the length of the list on each bucket...).
 107  *
 108  * Each state holds a pointer to the parent ipfw rule so we know what
 109  * action to perform. Dynamic rules are removed when the parent rule is
 110  * deleted.
 111  *
 112  * There are some limitations with dynamic rules -- we do not
 113  * obey the 'randomized match', and we do not do multiple
 114  * passes through the firewall. XXX check the latter!!!
 115  */
 116
 117 /* By default use jenkins hash function */
 118 #define IPFIREWALL_JENKINSHASH
 119
 120 #define DYN_COUNTER_INC(d, dir, pktlen) do {    \
 121         (d)->pcnt_ ## dir++;                    \
 122         (d)->bcnt_ ## dir += pktlen;            \
 123         } while (0)
 124
 125 struct dyn_data {
 126         void            *parent;        /* pointer to parent rule */
 127         uint32_t        chain_id;       /* cached ruleset id */
 128         uint32_t        f_pos;          /* cached rule index */
 129
 130         uint32_t        hashval;        /* hash value used for hash resize */
 131         uint16_t        fibnum;         /* fib used to send keepalives */
 132         uint8_t         _pad[3];
 133         uint8_t         set;            /* parent rule set number */
 134         uint16_t        rulenum;        /* parent rule number */
 135         uint32_t        ruleid;         /* parent rule id */
 136
 137         uint32_t        state;          /* TCP session state and flags */
 138         uint32_t        ack_fwd;        /* most recent ACKs in forward */
 139         uint32_t        ack_rev;        /* and reverse direction (used */
 140                                         /* to generate keepalives) */
 141         uint32_t        sync;           /* synchronization time */
 142         uint32_t        expire;         /* expire time */
 143
 144         uint64_t        pcnt_fwd;       /* bytes counter in forward */
 145         uint64_t        bcnt_fwd;       /* packets counter in forward */
 146         uint64_t        pcnt_rev;       /* bytes counter in reverse */
 147         uint64_t        bcnt_rev;       /* packets counter in reverse */
 148 };
 149
 150 #define DPARENT_COUNT_DEC(p)    do {                    \
 151         MPASS(p->count > 0);                            \
 152         ck_pr_dec_32(&(p)->count);                      \
 153 } while (0)
 154 #define DPARENT_COUNT_INC(p)    ck_pr_inc_32(&(p)->count)
 155 #define DPARENT_COUNT(p)        ck_pr_load_32(&(p)->count)
 156 struct dyn_parent {
 157         void            *parent;        /* pointer to parent rule */
 158         uint32_t        count;          /* number of linked states */
 159         uint8_t         _pad;
 160         uint8_t         set;            /* parent rule set number */
 161         uint16_t        rulenum;        /* parent rule number */
 162         uint32_t        ruleid;         /* parent rule id */
 163         uint32_t        hashval;        /* hash value used for hash resize */
 164         uint32_t        expire;         /* expire time */
 165 };
 166
 167 struct dyn_ipv4_state {
 168         uint8_t         type;           /* State type */
 169         uint8_t         proto;          /* UL Protocol */
 170         uint16_t        kidx;           /* named object index */
 171         uint16_t        sport, dport;   /* ULP source and destination ports */
 172         in_addr_t       src, dst;       /* IPv4 source and destination */
 173
 174         union {
 175                 struct dyn_data *data;
 176                 struct dyn_parent *limit;
 177         };
 178         CK_SLIST_ENTRY(dyn_ipv4_state)  entry;
 179         SLIST_ENTRY(dyn_ipv4_state)     expired;
 180 };
 181 CK_SLIST_HEAD(dyn_ipv4ck_slist, dyn_ipv4_state);
 182 VNET_DEFINE_STATIC(struct dyn_ipv4ck_slist *, dyn_ipv4);
 183 VNET_DEFINE_STATIC(struct dyn_ipv4ck_slist *, dyn_ipv4_parent);
 184
 185 SLIST_HEAD(dyn_ipv4_slist, dyn_ipv4_state);
 186 VNET_DEFINE_STATIC(struct dyn_ipv4_slist, dyn_expired_ipv4);
 187 #define V_dyn_ipv4                      VNET(dyn_ipv4)
 188 #define V_dyn_ipv4_parent               VNET(dyn_ipv4_parent)
 189 #define V_dyn_expired_ipv4              VNET(dyn_expired_ipv4)
 190
 191 #ifdef INET6
 192 struct dyn_ipv6_state {
 193         uint8_t         type;           /* State type */
 194         uint8_t         proto;          /* UL Protocol */
 195         uint16_t        kidx;           /* named object index */
 196         uint16_t        sport, dport;   /* ULP source and destination ports */
 197         struct in6_addr src, dst;       /* IPv6 source and destination */
 198         uint32_t        zoneid;         /* IPv6 scope zone id */
 199         union {
 200                 struct dyn_data *data;
 201                 struct dyn_parent *limit;
 202         };
 203         CK_SLIST_ENTRY(dyn_ipv6_state)  entry;
 204         SLIST_ENTRY(dyn_ipv6_state)     expired;
 205 };
 206 CK_SLIST_HEAD(dyn_ipv6ck_slist, dyn_ipv6_state);
 207 VNET_DEFINE_STATIC(struct dyn_ipv6ck_slist *, dyn_ipv6);
 208 VNET_DEFINE_STATIC(struct dyn_ipv6ck_slist *, dyn_ipv6_parent);
 209
 210 SLIST_HEAD(dyn_ipv6_slist, dyn_ipv6_state);
 211 VNET_DEFINE_STATIC(struct dyn_ipv6_slist, dyn_expired_ipv6);
 212 #define V_dyn_ipv6                      VNET(dyn_ipv6)
 213 #define V_dyn_ipv6_parent               VNET(dyn_ipv6_parent)
 214 #define V_dyn_expired_ipv6              VNET(dyn_expired_ipv6)
 215 #endif /* INET6 */
 216
 217 /*
 218  * Per-CPU pointer indicates that specified state is currently in use
 219  * and must not be reclaimed by expiration callout.
 220  */
 221 static void **dyn_hp_cache;
 222 DPCPU_DEFINE_STATIC(void *, dyn_hp);
 223 #define DYNSTATE_GET(cpu)       ck_pr_load_ptr(DPCPU_ID_PTR((cpu), dyn_hp))
 224 #define DYNSTATE_PROTECT(v)     ck_pr_store_ptr(DPCPU_PTR(dyn_hp), (v))
 225 #define DYNSTATE_RELEASE()      DYNSTATE_PROTECT(NULL)
 226 #define DYNSTATE_CRITICAL_ENTER()       critical_enter()
 227 #define DYNSTATE_CRITICAL_EXIT()        do {    \
 228         DYNSTATE_RELEASE();                     \
 229         critical_exit();                        \
 230 } while (0);
 231
 232 /*
 233  * We keep two version numbers, one is updated when new entry added to
 234  * the list. Second is updated when an entry deleted from the list.
 235  * Versions are updated under bucket lock.
 236  *
 237  * Bucket "add" version number is used to know, that in the time between
 238  * state lookup (i.e. ipfw_dyn_lookup_state()) and the followed state
 239  * creation (i.e. ipfw_dyn_install_state()) another concurrent thread did
 240  * not install some state in this bucket. Using this info we can avoid
 241  * additional state lookup, because we are sure that we will not install
 242  * the state twice.
 243  *
 244  * Also doing the tracking of bucket "del" version during lookup we can
 245  * be sure, that state entry was not unlinked and freed in time between
 246  * we read the state pointer and protect it with hazard pointer.
 247  *
 248  * An entry unlinked from CK list keeps unchanged until it is freed.
 249  * Unlinked entries are linked into expired lists using "expired" field.
 250  */
 251
 252 /*
 253  * dyn_expire_lock is used to protect access to dyn_expired_xxx lists.
 254  * dyn_bucket_lock is used to get write access to lists in specific bucket.
 255  * Currently one dyn_bucket_lock is used for all ipv4, ipv4_parent, ipv6,
 256  * and ipv6_parent lists.
 257  */
 258 VNET_DEFINE_STATIC(struct mtx, dyn_expire_lock);
 259 VNET_DEFINE_STATIC(struct mtx *, dyn_bucket_lock);
 260 #define V_dyn_expire_lock               VNET(dyn_expire_lock)
 261 #define V_dyn_bucket_lock               VNET(dyn_bucket_lock)
 262
 263 /*
 264  * Bucket's add/delete generation versions.
 265  */
 266 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_add);
 267 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_del);
 268 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_parent_add);
 269 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_parent_del);
 270 #define V_dyn_ipv4_add                  VNET(dyn_ipv4_add)
 271 #define V_dyn_ipv4_del                  VNET(dyn_ipv4_del)
 272 #define V_dyn_ipv4_parent_add           VNET(dyn_ipv4_parent_add)
 273 #define V_dyn_ipv4_parent_del           VNET(dyn_ipv4_parent_del)
 274
 275 #ifdef INET6
 276 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_add);
 277 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_del);
 278 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_parent_add);
 279 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_parent_del);
 280 #define V_dyn_ipv6_add                  VNET(dyn_ipv6_add)
 281 #define V_dyn_ipv6_del                  VNET(dyn_ipv6_del)
 282 #define V_dyn_ipv6_parent_add           VNET(dyn_ipv6_parent_add)
 283 #define V_dyn_ipv6_parent_del           VNET(dyn_ipv6_parent_del)
 284 #endif /* INET6 */
 285
 286 #define DYN_BUCKET(h, b)                ((h) & (b - 1))
 287 #define DYN_BUCKET_VERSION(b, v)        ck_pr_load_32(&V_dyn_ ## v[(b)])
 288 #define DYN_BUCKET_VERSION_BUMP(b, v)   ck_pr_inc_32(&V_dyn_ ## v[(b)])
 289
 290 #define DYN_BUCKET_LOCK_INIT(lock, b)           \
 291     mtx_init(&lock[(b)], "IPFW dynamic bucket", NULL, MTX_DEF)
 292 #define DYN_BUCKET_LOCK_DESTROY(lock, b)        mtx_destroy(&lock[(b)])
 293 #define DYN_BUCKET_LOCK(b)      mtx_lock(&V_dyn_bucket_lock[(b)])
 294 #define DYN_BUCKET_UNLOCK(b)    mtx_unlock(&V_dyn_bucket_lock[(b)])
 295 #define DYN_BUCKET_ASSERT(b)    mtx_assert(&V_dyn_bucket_lock[(b)], MA_OWNED)
 296
 297 #define DYN_EXPIRED_LOCK_INIT()         \
 298     mtx_init(&V_dyn_expire_lock, "IPFW expired states list", NULL, MTX_DEF)
 299 #define DYN_EXPIRED_LOCK_DESTROY()      mtx_destroy(&V_dyn_expire_lock)
 300 #define DYN_EXPIRED_LOCK()              mtx_lock(&V_dyn_expire_lock)
 301 #define DYN_EXPIRED_UNLOCK()            mtx_unlock(&V_dyn_expire_lock)
 302
 303 VNET_DEFINE_STATIC(uint32_t, dyn_buckets_max);
 304 VNET_DEFINE_STATIC(uint32_t, curr_dyn_buckets);
 305 VNET_DEFINE_STATIC(struct callout, dyn_timeout);
 306 #define V_dyn_buckets_max               VNET(dyn_buckets_max)
 307 #define V_curr_dyn_buckets              VNET(curr_dyn_buckets)
 308 #define V_dyn_timeout                   VNET(dyn_timeout)
 309
 310 /* Maximum length of states chain in a bucket */
 311 VNET_DEFINE_STATIC(uint32_t, curr_max_length);
 312 #define V_curr_max_length               VNET(curr_max_length)
 313
 314 VNET_DEFINE_STATIC(uint32_t, dyn_keep_states);
 315 #define V_dyn_keep_states               VNET(dyn_keep_states)
 316
 317 VNET_DEFINE_STATIC(uma_zone_t, dyn_data_zone);
 318 VNET_DEFINE_STATIC(uma_zone_t, dyn_parent_zone);
 319 VNET_DEFINE_STATIC(uma_zone_t, dyn_ipv4_zone);
 320 #ifdef INET6
 321 VNET_DEFINE_STATIC(uma_zone_t, dyn_ipv6_zone);
 322 #define V_dyn_ipv6_zone                 VNET(dyn_ipv6_zone)
 323 #endif /* INET6 */
 324 #define V_dyn_data_zone                 VNET(dyn_data_zone)
 325 #define V_dyn_parent_zone               VNET(dyn_parent_zone)
 326 #define V_dyn_ipv4_zone                 VNET(dyn_ipv4_zone)
 327
 328 /*
 329  * Timeouts for various events in handing dynamic rules.
 330  */
 331 VNET_DEFINE_STATIC(uint32_t, dyn_ack_lifetime);
 332 VNET_DEFINE_STATIC(uint32_t, dyn_syn_lifetime);
 333 VNET_DEFINE_STATIC(uint32_t, dyn_fin_lifetime);
 334 VNET_DEFINE_STATIC(uint32_t, dyn_rst_lifetime);
 335 VNET_DEFINE_STATIC(uint32_t, dyn_udp_lifetime);
 336 VNET_DEFINE_STATIC(uint32_t, dyn_short_lifetime);
 337
 338 #define V_dyn_ack_lifetime              VNET(dyn_ack_lifetime)
 339 #define V_dyn_syn_lifetime              VNET(dyn_syn_lifetime)
 340 #define V_dyn_fin_lifetime              VNET(dyn_fin_lifetime)
 341 #define V_dyn_rst_lifetime              VNET(dyn_rst_lifetime)
 342 #define V_dyn_udp_lifetime              VNET(dyn_udp_lifetime)
 343 #define V_dyn_short_lifetime            VNET(dyn_short_lifetime)
 344
 345 /*
 346  * Keepalives are sent if dyn_keepalive is set. They are sent every
 347  * dyn_keepalive_period seconds, in the last dyn_keepalive_interval
 348  * seconds of lifetime of a rule.
 349  * dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower
 350  * than dyn_keepalive_period.
 351  */
 352 #define DYN_KEEPALIVE_MAXQ              512
 353 VNET_DEFINE_STATIC(uint32_t, dyn_keepalive_interval);
 354 VNET_DEFINE_STATIC(uint32_t, dyn_keepalive_period);
 355 VNET_DEFINE_STATIC(uint32_t, dyn_keepalive);
 356 VNET_DEFINE_STATIC(time_t, dyn_keepalive_last);
 357
 358 #define V_dyn_keepalive_interval        VNET(dyn_keepalive_interval)
 359 #define V_dyn_keepalive_period          VNET(dyn_keepalive_period)
 360 #define V_dyn_keepalive                 VNET(dyn_keepalive)
 361 #define V_dyn_keepalive_last            VNET(dyn_keepalive_last)
 362
 363 VNET_DEFINE_STATIC(uint32_t, dyn_max);          /* max # of dynamic states */
 364 VNET_DEFINE_STATIC(uint32_t, dyn_count);        /* number of states */
 365 VNET_DEFINE_STATIC(uint32_t, dyn_parent_max);   /* max # of parent states */
 366 VNET_DEFINE_STATIC(uint32_t, dyn_parent_count); /* number of parent states */
 367
 368 #define V_dyn_max                       VNET(dyn_max)
 369 #define V_dyn_count                     VNET(dyn_count)
 370 #define V_dyn_parent_max                VNET(dyn_parent_max)
 371 #define V_dyn_parent_count              VNET(dyn_parent_count)
 372
 373 #define DYN_COUNT_DEC(name)     do {                    \
 374         MPASS((V_ ## name) > 0);                        \
 375         ck_pr_dec_32(&(V_ ## name));                    \
 376 } while (0)
 377 #define DYN_COUNT_INC(name)     ck_pr_inc_32(&(V_ ## name))
 378 #define DYN_COUNT(name)         ck_pr_load_32(&(V_ ## name))
 379
 380 static time_t last_log; /* Log ratelimiting */
 381
 382 /*
 383  * Get/set maximum number of dynamic states in given VNET instance.
 384  */
 385 static int
 386 sysctl_dyn_max(SYSCTL_HANDLER_ARGS)
 387 {
 388         uint32_t nstates;
 389         int error;
 390
 391         nstates = V_dyn_max;
 392         error = sysctl_handle_32(oidp, &nstates, 0, req);
 393         /* Read operation or some error */
 394         if ((error != 0) || (req->newptr == NULL))
 395                 return (error);
 396
 397         V_dyn_max = nstates;
 398         uma_zone_set_max(V_dyn_data_zone, V_dyn_max);
 399         return (0);
 400 }
 401
 402 static int
 403 sysctl_dyn_parent_max(SYSCTL_HANDLER_ARGS)
 404 {
 405         uint32_t nstates;
 406         int error;
 407
 408         nstates = V_dyn_parent_max;
 409         error = sysctl_handle_32(oidp, &nstates, 0, req);
 410         /* Read operation or some error */
 411         if ((error != 0) || (req->newptr == NULL))
 412                 return (error);
 413
 414         V_dyn_parent_max = nstates;
 415         uma_zone_set_max(V_dyn_parent_zone, V_dyn_parent_max);
 416         return (0);
 417 }
 418
 419 static int
 420 sysctl_dyn_buckets(SYSCTL_HANDLER_ARGS)
 421 {
 422         uint32_t nbuckets;
 423         int error;
 424
 425         nbuckets = V_dyn_buckets_max;
 426         error = sysctl_handle_32(oidp, &nbuckets, 0, req);
 427         /* Read operation or some error */
 428         if ((error != 0) || (req->newptr == NULL))
 429                 return (error);
 430
 431         if (nbuckets > 256)
 432                 V_dyn_buckets_max = 1 << fls(nbuckets - 1);
 433         else
 434                 return (EINVAL);
 435         return (0);
 436 }
 437
 438 SYSCTL_DECL(_net_inet_ip_fw);
 439
 440 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_count,
 441     CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(dyn_count), 0,
 442     "Current number of dynamic states.");
 443 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_parent_count,
 444     CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(dyn_parent_count), 0,
 445     "Current number of parent states. ");
 446 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets,
 447     CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(curr_dyn_buckets), 0,
 448     "Current number of buckets for states hash table.");
 449 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, curr_max_length,
 450     CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(curr_max_length), 0,
 451     "Current maximum length of states chains in hash buckets.");
 452 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_buckets,
 453     CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_RW, 0, 0, sysctl_dyn_buckets,
 454     "IU", "Max number of buckets for dynamic states hash table.");
 455 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_max,
 456     CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_RW, 0, 0, sysctl_dyn_max,
 457     "IU", "Max number of dynamic states.");
 458 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_parent_max,
 459     CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_RW, 0, 0, sysctl_dyn_parent_max,
 460     "IU", "Max number of parent dynamic states.");
 461 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime,
 462     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_ack_lifetime), 0,
 463     "Lifetime of dynamic states for TCP ACK.");
 464 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime,
 465     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_syn_lifetime), 0,
 466     "Lifetime of dynamic states for TCP SYN.");
 467 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime,
 468     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_fin_lifetime), 0,
 469     "Lifetime of dynamic states for TCP FIN.");
 470 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime,
 471     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_rst_lifetime), 0,
 472     "Lifetime of dynamic states for TCP RST.");
 473 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime,
 474     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_udp_lifetime), 0,
 475     "Lifetime of dynamic states for UDP.");
 476 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime,
 477     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_short_lifetime), 0,
 478     "Lifetime of dynamic states for other situations.");
 479 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_keepalive,
 480     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_keepalive), 0,
 481     "Enable keepalives for dynamic states.");
 482 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_keep_states,
 483     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_keep_states), 0,
 484     "Do not flush dynamic states on rule deletion");
 485
 486
 487 #ifdef IPFIREWALL_DYNDEBUG
 488 #define DYN_DEBUG(fmt, ...)     do {                    \
 489         printf("%s: " fmt "\n", __func__, __VA_ARGS__); \
 490 } while (0)
 491 #else
 492 #define DYN_DEBUG(fmt, ...)
 493 #endif /* !IPFIREWALL_DYNDEBUG */
 494
 495 #ifdef INET6
 496 /* Functions to work with IPv6 states */
 497 static struct dyn_ipv6_state *dyn_lookup_ipv6_state(
 498     const struct ipfw_flow_id *, uint32_t, const void *,
 499     struct ipfw_dyn_info *, int);
 500 static int dyn_lookup_ipv6_state_locked(const struct ipfw_flow_id *,
 501     uint32_t, const void *, int, uint32_t, uint16_t);
 502 static struct dyn_ipv6_state *dyn_alloc_ipv6_state(
 503     const struct ipfw_flow_id *, uint32_t, uint16_t, uint8_t);
 504 static int dyn_add_ipv6_state(void *, uint32_t, uint16_t, uint8_t,
 505     const struct ipfw_flow_id *, uint32_t, const void *, int, uint32_t,
 506     struct ipfw_dyn_info *, uint16_t, uint16_t, uint8_t);
 507 static void dyn_export_ipv6_state(const struct dyn_ipv6_state *,
 508     ipfw_dyn_rule *);
 509
 510 static uint32_t dyn_getscopeid(const struct ip_fw_args *);
 511 static void dyn_make_keepalive_ipv6(struct mbuf *, const struct in6_addr *,
 512     const struct in6_addr *, uint32_t, uint32_t, uint32_t, uint16_t,
 513     uint16_t);
 514 static void dyn_enqueue_keepalive_ipv6(struct mbufq *,
 515     const struct dyn_ipv6_state *);
 516 static void dyn_send_keepalive_ipv6(struct ip_fw_chain *);
 517
 518 static struct dyn_ipv6_state *dyn_lookup_ipv6_parent(
 519     const struct ipfw_flow_id *, uint32_t, const void *, uint32_t, uint16_t,
 520     uint32_t);
 521 static struct dyn_ipv6_state *dyn_lookup_ipv6_parent_locked(
 522     const struct ipfw_flow_id *, uint32_t, const void *, uint32_t, uint16_t,
 523     uint32_t);
 524 static struct dyn_ipv6_state *dyn_add_ipv6_parent(void *, uint32_t, uint16_t,
 525     uint8_t, const struct ipfw_flow_id *, uint32_t, uint32_t, uint32_t,
 526     uint16_t);
 527 #endif /* INET6 */
 528
 529 /* Functions to work with limit states */
 530 static void *dyn_get_parent_state(const struct ipfw_flow_id *, uint32_t,
 531     struct ip_fw *, uint32_t, uint32_t, uint16_t);
 532 static struct dyn_ipv4_state *dyn_lookup_ipv4_parent(
 533     const struct ipfw_flow_id *, const void *, uint32_t, uint16_t, uint32_t);
 534 static struct dyn_ipv4_state *dyn_lookup_ipv4_parent_locked(
 535     const struct ipfw_flow_id *, const void *, uint32_t, uint16_t, uint32_t);
 536 static struct dyn_parent *dyn_alloc_parent(void *, uint32_t, uint16_t,
 537     uint8_t, uint32_t);
 538 static struct dyn_ipv4_state *dyn_add_ipv4_parent(void *, uint32_t, uint16_t,
 539     uint8_t, const struct ipfw_flow_id *, uint32_t, uint32_t, uint16_t);
 540
 541 static void dyn_tick(void *);
 542 static void dyn_expire_states(struct ip_fw_chain *, ipfw_range_tlv *);
 543 static void dyn_free_states(struct ip_fw_chain *);
 544 static void dyn_export_parent(const struct dyn_parent *, uint16_t,
 545     ipfw_dyn_rule *);
 546 static void dyn_export_data(const struct dyn_data *, uint16_t, uint8_t,
 547     ipfw_dyn_rule *);
 548 static uint32_t dyn_update_tcp_state(struct dyn_data *,
 549     const struct ipfw_flow_id *, const struct tcphdr *, int);
 550 static void dyn_update_proto_state(struct dyn_data *,
 551     const struct ipfw_flow_id *, const void *, int, int);
 552
 553 /* Functions to work with IPv4 states */
 554 struct dyn_ipv4_state *dyn_lookup_ipv4_state(const struct ipfw_flow_id *,
 555     const void *, struct ipfw_dyn_info *, int);
 556 static int dyn_lookup_ipv4_state_locked(const struct ipfw_flow_id *,
 557     const void *, int, uint32_t, uint16_t);
 558 static struct dyn_ipv4_state *dyn_alloc_ipv4_state(
 559     const struct ipfw_flow_id *, uint16_t, uint8_t);
 560 static int dyn_add_ipv4_state(void *, uint32_t, uint16_t, uint8_t,
 561     const struct ipfw_flow_id *, const void *, int, uint32_t,
 562     struct ipfw_dyn_info *, uint16_t, uint16_t, uint8_t);
 563 static void dyn_export_ipv4_state(const struct dyn_ipv4_state *,
 564     ipfw_dyn_rule *);
 565
 566 /*
 567  * Named states support.
 568  */
 569 static char *default_state_name = "default";
 570 struct dyn_state_obj {
 571         struct named_object     no;
 572         char                    name[64];
 573 };
 574
 575 #define DYN_STATE_OBJ(ch, cmd)  \
 576     ((struct dyn_state_obj *)SRV_OBJECT(ch, (cmd)->arg1))
 577 /*
 578  * Classifier callback.
 579  * Return 0 if opcode contains object that should be referenced
 580  * or rewritten.
 581  */
 582 static int
 583 dyn_classify(ipfw_insn *cmd, uint16_t *puidx, uint8_t *ptype)
 584 {
 585
 586         DYN_DEBUG("opcode %d, arg1 %d", cmd->opcode, cmd->arg1);
 587         /* Don't rewrite "check-state any" */
 588         if (cmd->arg1 == 0 &&
 589             cmd->opcode == O_CHECK_STATE)
 590                 return (1);
 591
 592         *puidx = cmd->arg1;
 593         *ptype = 0;
 594         return (0);
 595 }
 596
 597 static void
 598 dyn_update(ipfw_insn *cmd, uint16_t idx)
 599 {
 600
 601         cmd->arg1 = idx;
 602         DYN_DEBUG("opcode %d, arg1 %d", cmd->opcode, cmd->arg1);
 603 }
 604
 605 static int
 606 dyn_findbyname(struct ip_fw_chain *ch, struct tid_info *ti,
 607     struct named_object **pno)
 608 {
 609         ipfw_obj_ntlv *ntlv;
 610         const char *name;
 611
 612         DYN_DEBUG("uidx %d", ti->uidx);
 613         if (ti->uidx != 0) {
 614                 if (ti->tlvs == NULL)
 615                         return (EINVAL);
 616                 /* Search ntlv in the buffer provided by user */
 617                 ntlv = ipfw_find_name_tlv_type(ti->tlvs, ti->tlen, ti->uidx,
 618                     IPFW_TLV_STATE_NAME);
 619                 if (ntlv == NULL)
 620                         return (EINVAL);
 621                 name = ntlv->name;
 622         } else
 623                 name = default_state_name;
 624         /*
 625          * Search named object with corresponding name.
 626          * Since states objects are global - ignore the set value
 627          * and use zero instead.
 628          */
 629         *pno = ipfw_objhash_lookup_name_type(CHAIN_TO_SRV(ch), 0,
 630             IPFW_TLV_STATE_NAME, name);
 631         /*
 632          * We always return success here.
 633          * The caller will check *pno and mark object as unresolved,
 634          * then it will automatically create "default" object.
 635          */
 636         return (0);
 637 }
 638
 639 static struct named_object *
 640 dyn_findbykidx(struct ip_fw_chain *ch, uint16_t idx)
 641 {
 642
 643         DYN_DEBUG("kidx %d", idx);
 644         return (ipfw_objhash_lookup_kidx(CHAIN_TO_SRV(ch), idx));
 645 }
 646
 647 static int
 648 dyn_create(struct ip_fw_chain *ch, struct tid_info *ti,
 649     uint16_t *pkidx)
 650 {
 651         struct namedobj_instance *ni;
 652         struct dyn_state_obj *obj;
 653         struct named_object *no;
 654         ipfw_obj_ntlv *ntlv;
 655         char *name;
 656
 657         DYN_DEBUG("uidx %d", ti->uidx);
 658         if (ti->uidx != 0) {
 659                 if (ti->tlvs == NULL)
 660                         return (EINVAL);
 661                 ntlv = ipfw_find_name_tlv_type(ti->tlvs, ti->tlen, ti->uidx,
 662                     IPFW_TLV_STATE_NAME);
 663                 if (ntlv == NULL)
 664                         return (EINVAL);
 665                 name = ntlv->name;
 666         } else
 667                 name = default_state_name;
 668
 669         ni = CHAIN_TO_SRV(ch);
 670         obj = malloc(sizeof(*obj), M_IPFW, M_WAITOK | M_ZERO);
 671         obj->no.name = obj->name;
 672         obj->no.etlv = IPFW_TLV_STATE_NAME;
 673         strlcpy(obj->name, name, sizeof(obj->name));
 674
 675         IPFW_UH_WLOCK(ch);
 676         no = ipfw_objhash_lookup_name_type(ni, 0,
 677             IPFW_TLV_STATE_NAME, name);
 678         if (no != NULL) {
 679                 /*
 680                  * Object is already created.
 681                  * Just return its kidx and bump refcount.
 682                  */
 683                 *pkidx = no->kidx;
 684                 no->refcnt++;
 685                 IPFW_UH_WUNLOCK(ch);
 686                 free(obj, M_IPFW);
 687                 DYN_DEBUG("\tfound kidx %d", *pkidx);
 688                 return (0);
 689         }
 690         if (ipfw_objhash_alloc_idx(ni, &obj->no.kidx) != 0) {
 691                 DYN_DEBUG("\talloc_idx failed for %s", name);
 692                 IPFW_UH_WUNLOCK(ch);
 693                 free(obj, M_IPFW);
 694                 return (ENOSPC);
 695         }
 696         ipfw_objhash_add(ni, &obj->no);
 697         SRV_OBJECT(ch, obj->no.kidx) = obj;
 698         obj->no.refcnt++;
 699         *pkidx = obj->no.kidx;
 700         IPFW_UH_WUNLOCK(ch);
 701         DYN_DEBUG("\tcreated kidx %d", *pkidx);
 702         return (0);
 703 }
 704
 705 static void
 706 dyn_destroy(struct ip_fw_chain *ch, struct named_object *no)
 707 {
 708         struct dyn_state_obj *obj;
 709
 710         IPFW_UH_WLOCK_ASSERT(ch);
 711
 712         KASSERT(no->refcnt == 1,
 713             ("Destroying object '%s' (type %u, idx %u) with refcnt %u",
 714             no->name, no->etlv, no->kidx, no->refcnt));
 715         DYN_DEBUG("kidx %d", no->kidx);
 716         obj = SRV_OBJECT(ch, no->kidx);
 717         SRV_OBJECT(ch, no->kidx) = NULL;
 718         ipfw_objhash_del(CHAIN_TO_SRV(ch), no);
 719         ipfw_objhash_free_idx(CHAIN_TO_SRV(ch), no->kidx);
 720
 721         free(obj, M_IPFW);
 722 }
 723
 724 static struct opcode_obj_rewrite dyn_opcodes[] = {
 725         {
 726                 O_KEEP_STATE, IPFW_TLV_STATE_NAME,
 727                 dyn_classify, dyn_update,
 728                 dyn_findbyname, dyn_findbykidx,
 729                 dyn_create, dyn_destroy
 730         },
 731         {
 732                 O_CHECK_STATE, IPFW_TLV_STATE_NAME,
 733                 dyn_classify, dyn_update,
 734                 dyn_findbyname, dyn_findbykidx,
 735                 dyn_create, dyn_destroy
 736         },
 737         {
 738                 O_PROBE_STATE, IPFW_TLV_STATE_NAME,
 739                 dyn_classify, dyn_update,
 740                 dyn_findbyname, dyn_findbykidx,
 741                 dyn_create, dyn_destroy
 742         },
 743         {
 744                 O_LIMIT, IPFW_TLV_STATE_NAME,
 745                 dyn_classify, dyn_update,
 746                 dyn_findbyname, dyn_findbykidx,
 747                 dyn_create, dyn_destroy
 748         },
 749 };
 750
 751 /*
 752  * IMPORTANT: the hash function for dynamic rules must be commutative
 753  * in source and destination (ip,port), because rules are bidirectional
 754  * and we want to find both in the same bucket.
 755  */
 756 #ifndef IPFIREWALL_JENKINSHASH
 757 static __inline uint32_t
 758 hash_packet(const struct ipfw_flow_id *id)
 759 {
 760         uint32_t i;
 761
 762 #ifdef INET6
 763         if (IS_IP6_FLOW_ID(id))
 764                 i = ntohl((id->dst_ip6.__u6_addr.__u6_addr32[2]) ^
 765                     (id->dst_ip6.__u6_addr.__u6_addr32[3]) ^
 766                     (id->src_ip6.__u6_addr.__u6_addr32[2]) ^
 767                     (id->src_ip6.__u6_addr.__u6_addr32[3]));
 768         else
 769 #endif /* INET6 */
 770         i = (id->dst_ip) ^ (id->src_ip);
 771         i ^= (id->dst_port) ^ (id->src_port);
 772         return (i);
 773 }
 774
 775 static __inline uint32_t
 776 hash_parent(const struct ipfw_flow_id *id, const void *rule)
 777 {
 778
 779         return (hash_packet(id) ^ ((uintptr_t)rule));
 780 }
 781
 782 #else /* IPFIREWALL_JENKINSHASH */
 783
 784 VNET_DEFINE_STATIC(uint32_t, dyn_hashseed);
 785 #define V_dyn_hashseed          VNET(dyn_hashseed)
 786
 787 static __inline int
 788 addrcmp4(const struct ipfw_flow_id *id)
 789 {
 790
 791         if (id->src_ip < id->dst_ip)
 792                 return (0);
 793         if (id->src_ip > id->dst_ip)
 794                 return (1);
 795         if (id->src_port <= id->dst_port)
 796                 return (0);
 797         return (1);
 798 }
 799
 800 #ifdef INET6
 801 static __inline int
 802 addrcmp6(const struct ipfw_flow_id *id)
 803 {
 804         int ret;
 805
 806         ret = memcmp(&id->src_ip6, &id->dst_ip6, sizeof(struct in6_addr));
 807         if (ret < 0)
 808                 return (0);
 809         if (ret > 0)
 810                 return (1);
 811         if (id->src_port <= id->dst_port)
 812                 return (0);
 813         return (1);
 814 }
 815
 816 static __inline uint32_t
 817 hash_packet6(const struct ipfw_flow_id *id)
 818 {
 819         struct tuple6 {
 820                 struct in6_addr addr[2];
 821                 uint16_t        port[2];
 822         } t6;
 823
 824         if (addrcmp6(id) == 0) {
 825                 t6.addr[0] = id->src_ip6;
 826                 t6.addr[1] = id->dst_ip6;
 827                 t6.port[0] = id->src_port;
 828                 t6.port[1] = id->dst_port;
 829         } else {
 830                 t6.addr[0] = id->dst_ip6;
 831                 t6.addr[1] = id->src_ip6;
 832                 t6.port[0] = id->dst_port;
 833                 t6.port[1] = id->src_port;
 834         }
 835         return (jenkins_hash32((const uint32_t *)&t6,
 836             sizeof(t6) / sizeof(uint32_t), V_dyn_hashseed));
 837 }
 838 #endif
 839
 840 static __inline uint32_t
 841 hash_packet(const struct ipfw_flow_id *id)
 842 {
 843         struct tuple4 {
 844                 in_addr_t       addr[2];
 845                 uint16_t        port[2];
 846         } t4;
 847
 848         if (IS_IP4_FLOW_ID(id)) {
 849                 /* All fields are in host byte order */
 850                 if (addrcmp4(id) == 0) {
 851                         t4.addr[0] = id->src_ip;
 852                         t4.addr[1] = id->dst_ip;
 853                         t4.port[0] = id->src_port;
 854                         t4.port[1] = id->dst_port;
 855                 } else {
 856                         t4.addr[0] = id->dst_ip;
 857                         t4.addr[1] = id->src_ip;
 858                         t4.port[0] = id->dst_port;
 859                         t4.port[1] = id->src_port;
 860                 }
 861                 return (jenkins_hash32((const uint32_t *)&t4,
 862                     sizeof(t4) / sizeof(uint32_t), V_dyn_hashseed));
 863         } else
 864 #ifdef INET6
 865         if (IS_IP6_FLOW_ID(id))
 866                 return (hash_packet6(id));
 867 #endif
 868         return (0);
 869 }
 870
 871 static __inline uint32_t
 872 hash_parent(const struct ipfw_flow_id *id, const void *rule)
 873 {
 874
 875         return (jenkins_hash32((const uint32_t *)&rule,
 876             sizeof(rule) / sizeof(uint32_t), hash_packet(id)));
 877 }
 878 #endif /* IPFIREWALL_JENKINSHASH */
 879
 880 /*
 881  * Print customizable flow id description via log(9) facility.
 882  */
 883 static void
 884 print_dyn_rule_flags(const struct ipfw_flow_id *id, int dyn_type,
 885     int log_flags, char *prefix, char *postfix)
 886 {
 887         struct in_addr da;
 888 #ifdef INET6
 889         char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN];
 890 #else
 891         char src[INET_ADDRSTRLEN], dst[INET_ADDRSTRLEN];
 892 #endif
 893
 894 #ifdef INET6
 895         if (IS_IP6_FLOW_ID(id)) {
 896                 ip6_sprintf(src, &id->src_ip6);
 897                 ip6_sprintf(dst, &id->dst_ip6);
 898         } else
 899 #endif
 900         {
 901                 da.s_addr = htonl(id->src_ip);
 902                 inet_ntop(AF_INET, &da, src, sizeof(src));
 903                 da.s_addr = htonl(id->dst_ip);
 904                 inet_ntop(AF_INET, &da, dst, sizeof(dst));
 905         }
 906         log(log_flags, "ipfw: %s type %d %s %d -> %s %d, %d %s\n",
 907             prefix, dyn_type, src, id->src_port, dst,
 908             id->dst_port, V_dyn_count, postfix);
 909 }
 910
 911 #define print_dyn_rule(id, dtype, prefix, postfix)      \
 912         print_dyn_rule_flags(id, dtype, LOG_DEBUG, prefix, postfix)
 913
 914 #define TIME_LEQ(a,b)   ((int)((a)-(b)) <= 0)
 915 #define TIME_LE(a,b)    ((int)((a)-(b)) < 0)
 916 #define _SEQ_GE(a,b)    ((int)((a)-(b)) >= 0)
 917 #define BOTH_SYN        (TH_SYN | (TH_SYN << 8))
 918 #define BOTH_FIN        (TH_FIN | (TH_FIN << 8))
 919 #define TCP_FLAGS       (TH_FLAGS | (TH_FLAGS << 8))
 920 #define ACK_FWD         0x00010000      /* fwd ack seen */
 921 #define ACK_REV         0x00020000      /* rev ack seen */
 922 #define ACK_BOTH        (ACK_FWD | ACK_REV)
 923
 924 static uint32_t
 925 dyn_update_tcp_state(struct dyn_data *data, const struct ipfw_flow_id *pkt,
 926     const struct tcphdr *tcp, int dir)
 927 {
 928         uint32_t ack, expire;
 929         uint32_t state, old;
 930         uint8_t th_flags;
 931
 932         expire = data->expire;
 933         old = state = data->state;
 934         th_flags = pkt->_flags & (TH_FIN | TH_SYN | TH_RST);
 935         state |= (dir == MATCH_FORWARD) ? th_flags: (th_flags << 8);
 936         switch (state & TCP_FLAGS) {
 937         case TH_SYN:                    /* opening */
 938                 expire = time_uptime + V_dyn_syn_lifetime;
 939                 break;
 940
 941         case BOTH_SYN:                  /* move to established */
 942         case BOTH_SYN | TH_FIN:         /* one side tries to close */
 943         case BOTH_SYN | (TH_FIN << 8):
 944                 if (tcp == NULL)
 945                         break;
 946                 ack = ntohl(tcp->th_ack);
 947                 if (dir == MATCH_FORWARD) {
 948                         if (data->ack_fwd == 0 ||
 949                             _SEQ_GE(ack, data->ack_fwd)) {
 950                                 state |= ACK_FWD;
 951                                 if (data->ack_fwd != ack)
 952                                         ck_pr_store_32(&data->ack_fwd, ack);
 953                         }
 954                 } else {
 955                         if (data->ack_rev == 0 ||
 956                             _SEQ_GE(ack, data->ack_rev)) {
 957                                 state |= ACK_REV;
 958                                 if (data->ack_rev != ack)
 959                                         ck_pr_store_32(&data->ack_rev, ack);
 960                         }
 961                 }
 962                 if ((state & ACK_BOTH) == ACK_BOTH) {
 963                         /*
 964                          * Set expire time to V_dyn_ack_lifetime only if
 965                          * we got ACKs for both directions.
 966                          * We use XOR here to avoid possible state
 967                          * overwriting in concurrent thread.
 968                          */
 969                         expire = time_uptime + V_dyn_ack_lifetime;
 970                         ck_pr_xor_32(&data->state, ACK_BOTH);
 971                 } else if ((data->state & ACK_BOTH) != (state & ACK_BOTH))
 972                         ck_pr_or_32(&data->state, state & ACK_BOTH);
 973                 break;
 974
 975         case BOTH_SYN | BOTH_FIN:       /* both sides closed */
 976                 if (V_dyn_fin_lifetime >= V_dyn_keepalive_period)
 977                         V_dyn_fin_lifetime = V_dyn_keepalive_period - 1;
 978                 expire = time_uptime + V_dyn_fin_lifetime;
 979                 break;
 980
 981         default:
 982                 if (V_dyn_rst_lifetime >= V_dyn_keepalive_period)
 983                         V_dyn_rst_lifetime = V_dyn_keepalive_period - 1;
 984                 expire = time_uptime + V_dyn_rst_lifetime;
 985         }
 986         /* Save TCP state if it was changed */
 987         if ((state & TCP_FLAGS) != (old & TCP_FLAGS))
 988                 ck_pr_or_32(&data->state, state & TCP_FLAGS);
 989         return (expire);
 990 }
 991
 992 /*
 993  * Update ULP specific state.
 994  * For TCP we keep sequence numbers and flags. For other protocols
 995  * currently we update only expire time. Packets and bytes counters
 996  * are also updated here.
 997  */
 998 static void
 999 dyn_update_proto_state(struct dyn_data *data, const struct ipfw_flow_id *pkt,
1000     const void *ulp, int pktlen, int dir)
1001 {
1002         uint32_t expire;
1003
1004         /* NOTE: we are in critical section here. */
1005         switch (pkt->proto) {
1006         case IPPROTO_UDP:
1007         case IPPROTO_UDPLITE:
1008                 expire = time_uptime + V_dyn_udp_lifetime;
1009                 break;
1010         case IPPROTO_TCP:
1011                 expire = dyn_update_tcp_state(data, pkt, ulp, dir);
1012                 break;
1013         default:
1014                 expire = time_uptime + V_dyn_short_lifetime;
1015         }
1016         /*
1017          * Expiration timer has the per-second granularity, no need to update
1018          * it every time when state is matched.
1019          */
1020         if (data->expire != expire)
1021                 ck_pr_store_32(&data->expire, expire);
1022
1023         if (dir == MATCH_FORWARD)
1024                 DYN_COUNTER_INC(data, fwd, pktlen);
1025         else
1026                 DYN_COUNTER_INC(data, rev, pktlen);
1027 }
1028
1029 /*
1030  * Lookup IPv4 state.
1031  * Must be called in critical section.
1032  */
1033 struct dyn_ipv4_state *
1034 dyn_lookup_ipv4_state(const struct ipfw_flow_id *pkt, const void *ulp,
1035     struct ipfw_dyn_info *info, int pktlen)
1036 {
1037         struct dyn_ipv4_state *s;
1038         uint32_t version, bucket;
1039
1040         bucket = DYN_BUCKET(info->hashval, V_curr_dyn_buckets);
1041         info->version = DYN_BUCKET_VERSION(bucket, ipv4_add);
1042 restart:
1043         version = DYN_BUCKET_VERSION(bucket, ipv4_del);
1044         CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) {
1045                 DYNSTATE_PROTECT(s);
1046                 if (version != DYN_BUCKET_VERSION(bucket, ipv4_del))
1047                         goto restart;
1048                 if (s->proto != pkt->proto)
1049                         continue;
1050                 if (info->kidx != 0 && s->kidx != info->kidx)
1051                         continue;
1052                 if (s->sport == pkt->src_port && s->dport == pkt->dst_port &&
1053                     s->src == pkt->src_ip && s->dst == pkt->dst_ip) {
1054                         info->direction = MATCH_FORWARD;
1055                         break;
1056                 }
1057                 if (s->sport == pkt->dst_port && s->dport == pkt->src_port &&
1058                     s->src == pkt->dst_ip && s->dst == pkt->src_ip) {
1059                         info->direction = MATCH_REVERSE;
1060                         break;
1061                 }
1062         }
1063
1064         if (s != NULL)
1065                 dyn_update_proto_state(s->data, pkt, ulp, pktlen,
1066                     info->direction);
1067         return (s);
1068 }
1069
1070 /*
1071  * Lookup IPv4 state.
1072  * Simplifed version is used to check that matching state doesn't exist.
1073  */
1074 static int
1075 dyn_lookup_ipv4_state_locked(const struct ipfw_flow_id *pkt,
1076     const void *ulp, int pktlen, uint32_t bucket, uint16_t kidx)
1077 {
1078         struct dyn_ipv4_state *s;
1079         int dir;
1080
1081         dir = MATCH_NONE;
1082         DYN_BUCKET_ASSERT(bucket);
1083         CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) {
1084                 if (s->proto != pkt->proto ||
1085                     s->kidx != kidx)
1086                         continue;
1087                 if (s->sport == pkt->src_port &&
1088                     s->dport == pkt->dst_port &&
1089                     s->src == pkt->src_ip && s->dst == pkt->dst_ip) {
1090                         dir = MATCH_FORWARD;
1091                         break;
1092                 }
1093                 if (s->sport == pkt->dst_port && s->dport == pkt->src_port &&
1094                     s->src == pkt->dst_ip && s->dst == pkt->src_ip) {
1095                         dir = MATCH_REVERSE;
1096                         break;
1097                 }
1098         }
1099         if (s != NULL)
1100                 dyn_update_proto_state(s->data, pkt, ulp, pktlen, dir);
1101         return (s != NULL);
1102 }
1103
1104 struct dyn_ipv4_state *
1105 dyn_lookup_ipv4_parent(const struct ipfw_flow_id *pkt, const void *rule,
1106     uint32_t ruleid, uint16_t rulenum, uint32_t hashval)
1107 {
1108         struct dyn_ipv4_state *s;
1109         uint32_t version, bucket;
1110
1111         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1112 restart:
1113         version = DYN_BUCKET_VERSION(bucket, ipv4_parent_del);
1114         CK_SLIST_FOREACH(s, &V_dyn_ipv4_parent[bucket], entry) {
1115                 DYNSTATE_PROTECT(s);
1116                 if (version != DYN_BUCKET_VERSION(bucket, ipv4_parent_del))
1117                         goto restart;
1118                 /*
1119                  * NOTE: we do not need to check kidx, because parent rule
1120                  * can not create states with different kidx.
1121                  * And parent rule always created for forward direction.
1122                  */
1123                 if (s->limit->parent == rule &&
1124                     s->limit->ruleid == ruleid &&
1125                     s->limit->rulenum == rulenum &&
1126                     s->proto == pkt->proto &&
1127                     s->sport == pkt->src_port &&
1128                     s->dport == pkt->dst_port &&
1129                     s->src == pkt->src_ip && s->dst == pkt->dst_ip) {
1130                         if (s->limit->expire != time_uptime +
1131                             V_dyn_short_lifetime)
1132                                 ck_pr_store_32(&s->limit->expire,
1133                                     time_uptime + V_dyn_short_lifetime);
1134                         break;
1135                 }
1136         }
1137         return (s);
1138 }
1139
1140 static struct dyn_ipv4_state *
1141 dyn_lookup_ipv4_parent_locked(const struct ipfw_flow_id *pkt,
1142     const void *rule, uint32_t ruleid, uint16_t rulenum, uint32_t bucket)
1143 {
1144         struct dyn_ipv4_state *s;
1145
1146         DYN_BUCKET_ASSERT(bucket);
1147         CK_SLIST_FOREACH(s, &V_dyn_ipv4_parent[bucket], entry) {
1148                 if (s->limit->parent == rule &&
1149                     s->limit->ruleid == ruleid &&
1150                     s->limit->rulenum == rulenum &&
1151                     s->proto == pkt->proto &&
1152                     s->sport == pkt->src_port &&
1153                     s->dport == pkt->dst_port &&
1154                     s->src == pkt->src_ip && s->dst == pkt->dst_ip)
1155                         break;
1156         }
1157         return (s);
1158 }
1159
1160
1161 #ifdef INET6
1162 static uint32_t
1163 dyn_getscopeid(const struct ip_fw_args *args)
1164 {
1165
1166         /*
1167          * If source or destination address is an scopeid address, we need
1168          * determine the scope zone id to resolve address scope ambiguity.
1169          */
1170         if (IN6_IS_ADDR_LINKLOCAL(&args->f_id.src_ip6) ||
1171             IN6_IS_ADDR_LINKLOCAL(&args->f_id.dst_ip6)) {
1172                 MPASS(args->oif != NULL ||
1173                     args->m->m_pkthdr.rcvif != NULL);
1174                 return (in6_getscopezone(args->oif != NULL ? args->oif:
1175                     args->m->m_pkthdr.rcvif, IPV6_ADDR_SCOPE_LINKLOCAL));
1176         }
1177         return (0);
1178 }
1179
1180 /*
1181  * Lookup IPv6 state.
1182  * Must be called in critical section.
1183  */
1184 static struct dyn_ipv6_state *
1185 dyn_lookup_ipv6_state(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1186     const void *ulp, struct ipfw_dyn_info *info, int pktlen)
1187 {
1188         struct dyn_ipv6_state *s;
1189         uint32_t version, bucket;
1190
1191         bucket = DYN_BUCKET(info->hashval, V_curr_dyn_buckets);
1192         info->version = DYN_BUCKET_VERSION(bucket, ipv6_add);
1193 restart:
1194         version = DYN_BUCKET_VERSION(bucket, ipv6_del);
1195         CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) {
1196                 DYNSTATE_PROTECT(s);
1197                 if (version != DYN_BUCKET_VERSION(bucket, ipv6_del))
1198                         goto restart;
1199                 if (s->proto != pkt->proto || s->zoneid != zoneid)
1200                         continue;
1201                 if (info->kidx != 0 && s->kidx != info->kidx)
1202                         continue;
1203                 if (s->sport == pkt->src_port && s->dport == pkt->dst_port &&
1204                     IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) &&
1205                     IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) {
1206                         info->direction = MATCH_FORWARD;
1207                         break;
1208                 }
1209                 if (s->sport == pkt->dst_port && s->dport == pkt->src_port &&
1210                     IN6_ARE_ADDR_EQUAL(&s->src, &pkt->dst_ip6) &&
1211                     IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->src_ip6)) {
1212                         info->direction = MATCH_REVERSE;
1213                         break;
1214                 }
1215         }
1216         if (s != NULL)
1217                 dyn_update_proto_state(s->data, pkt, ulp, pktlen,
1218                     info->direction);
1219         return (s);
1220 }
1221
1222 /*
1223  * Lookup IPv6 state.
1224  * Simplifed version is used to check that matching state doesn't exist.
1225  */
1226 static int
1227 dyn_lookup_ipv6_state_locked(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1228     const void *ulp, int pktlen, uint32_t bucket, uint16_t kidx)
1229 {
1230         struct dyn_ipv6_state *s;
1231         int dir;
1232
1233         dir = MATCH_NONE;
1234         DYN_BUCKET_ASSERT(bucket);
1235         CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) {
1236                 if (s->proto != pkt->proto || s->kidx != kidx ||
1237                     s->zoneid != zoneid)
1238                         continue;
1239                 if (s->sport == pkt->src_port && s->dport == pkt->dst_port &&
1240                     IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) &&
1241                     IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) {
1242                         dir = MATCH_FORWARD;
1243                         break;
1244                 }
1245                 if (s->sport == pkt->dst_port && s->dport == pkt->src_port &&
1246                     IN6_ARE_ADDR_EQUAL(&s->src, &pkt->dst_ip6) &&
1247                     IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->src_ip6)) {
1248                         dir = MATCH_REVERSE;
1249                         break;
1250                 }
1251         }
1252         if (s != NULL)
1253                 dyn_update_proto_state(s->data, pkt, ulp, pktlen, dir);
1254         return (s != NULL);
1255 }
1256
1257 static struct dyn_ipv6_state *
1258 dyn_lookup_ipv6_parent(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1259     const void *rule, uint32_t ruleid, uint16_t rulenum, uint32_t hashval)
1260 {
1261         struct dyn_ipv6_state *s;
1262         uint32_t version, bucket;
1263
1264         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1265 restart:
1266         version = DYN_BUCKET_VERSION(bucket, ipv6_parent_del);
1267         CK_SLIST_FOREACH(s, &V_dyn_ipv6_parent[bucket], entry) {
1268                 DYNSTATE_PROTECT(s);
1269                 if (version != DYN_BUCKET_VERSION(bucket, ipv6_parent_del))
1270                         goto restart;
1271                 /*
1272                  * NOTE: we do not need to check kidx, because parent rule
1273                  * can not create states with different kidx.
1274                  * Also parent rule always created for forward direction.
1275                  */
1276                 if (s->limit->parent == rule &&
1277                     s->limit->ruleid == ruleid &&
1278                     s->limit->rulenum == rulenum &&
1279                     s->proto == pkt->proto &&
1280                     s->sport == pkt->src_port &&
1281                     s->dport == pkt->dst_port && s->zoneid == zoneid &&
1282                     IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) &&
1283                     IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) {
1284                         if (s->limit->expire != time_uptime +
1285                             V_dyn_short_lifetime)
1286                                 ck_pr_store_32(&s->limit->expire,
1287                                     time_uptime + V_dyn_short_lifetime);
1288                         break;
1289                 }
1290         }
1291         return (s);
1292 }
1293
1294 static struct dyn_ipv6_state *
1295 dyn_lookup_ipv6_parent_locked(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1296     const void *rule, uint32_t ruleid, uint16_t rulenum, uint32_t bucket)
1297 {
1298         struct dyn_ipv6_state *s;
1299
1300         DYN_BUCKET_ASSERT(bucket);
1301         CK_SLIST_FOREACH(s, &V_dyn_ipv6_parent[bucket], entry) {
1302                 if (s->limit->parent == rule &&
1303                     s->limit->ruleid == ruleid &&
1304                     s->limit->rulenum == rulenum &&
1305                     s->proto == pkt->proto &&
1306                     s->sport == pkt->src_port &&
1307                     s->dport == pkt->dst_port && s->zoneid == zoneid &&
1308                     IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) &&
1309                     IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6))
1310                         break;
1311         }
1312         return (s);
1313 }
1314
1315 #endif /* INET6 */
1316
1317 /*
1318  * Lookup dynamic state.
1319  *  pkt - filled by ipfw_chk() ipfw_flow_id;
1320  *  ulp - determined by ipfw_chk() upper level protocol header;
1321  *  dyn_info - info about matched state to return back;
1322  * Returns pointer to state's parent rule and dyn_info. If there is
1323  * no state, NULL is returned.
1324  * On match ipfw_dyn_lookup() updates state's counters.
1325  */
1326 struct ip_fw *
1327 ipfw_dyn_lookup_state(const struct ip_fw_args *args, const void *ulp,
1328     int pktlen, const ipfw_insn *cmd, struct ipfw_dyn_info *info)
1329 {
1330         struct dyn_data *data;
1331         struct ip_fw *rule;
1332
1333         IPFW_RLOCK_ASSERT(&V_layer3_chain);
1334
1335         data = NULL;
1336         rule = NULL;
1337         info->kidx = cmd->arg1;
1338         info->direction = MATCH_NONE;
1339         info->hashval = hash_packet(&args->f_id);
1340
1341         DYNSTATE_CRITICAL_ENTER();
1342         if (IS_IP4_FLOW_ID(&args->f_id)) {
1343                 struct dyn_ipv4_state *s;
1344
1345                 s = dyn_lookup_ipv4_state(&args->f_id, ulp, info, pktlen);
1346                 if (s != NULL) {
1347                         /*
1348                          * Dynamic states are created using the same 5-tuple,
1349                          * so it is assumed, that parent rule for O_LIMIT
1350                          * state has the same address family.
1351                          */
1352                         data = s->data;
1353                         if (s->type == O_LIMIT) {
1354                                 s = data->parent;
1355                                 rule = s->limit->parent;
1356                         } else
1357                                 rule = data->parent;
1358                 }
1359         }
1360 #ifdef INET6
1361         else if (IS_IP6_FLOW_ID(&args->f_id)) {
1362                 struct dyn_ipv6_state *s;
1363
1364                 s = dyn_lookup_ipv6_state(&args->f_id, dyn_getscopeid(args),
1365                     ulp, info, pktlen);
1366                 if (s != NULL) {
1367                         data = s->data;
1368                         if (s->type == O_LIMIT) {
1369                                 s = data->parent;
1370                                 rule = s->limit->parent;
1371                         } else
1372                                 rule = data->parent;
1373                 }
1374         }
1375 #endif
1376         if (data != NULL) {
1377                 /*
1378                  * If cached chain id is the same, we can avoid rule index
1379                  * lookup. Otherwise do lookup and update chain_id and f_pos.
1380                  * It is safe even if there is concurrent thread that want
1381                  * update the same state, because chain->id can be changed
1382                  * only under IPFW_WLOCK().
1383                  */
1384                 if (data->chain_id != V_layer3_chain.id) {
1385                         data->f_pos = ipfw_find_rule(&V_layer3_chain,
1386                             data->rulenum, data->ruleid);
1387                         /*
1388                          * Check that found state has not orphaned.
1389                          * When chain->id being changed the parent
1390                          * rule can be deleted. If found rule doesn't
1391                          * match the parent pointer, consider this
1392                          * result as MATCH_NONE and return NULL.
1393                          *
1394                          * This will lead to creation of new similar state
1395                          * that will be added into head of this bucket.
1396                          * And the state that we currently have matched
1397                          * should be deleted by dyn_expire_states().
1398                          *
1399                          * In case when dyn_keep_states is enabled, return
1400                          * pointer to default rule and corresponding f_pos
1401                          * value.
1402                          * XXX: In this case we lose the cache efficiency,
1403                          *      since f_pos is not cached, because it seems
1404                          *      there is no easy way to atomically switch
1405                          *      all fields related to parent rule of given
1406                          *      state.
1407                          */
1408                         if (V_layer3_chain.map[data->f_pos] == rule) {
1409                                 data->chain_id = V_layer3_chain.id;
1410                                 info->f_pos = data->f_pos;
1411                         } else if (V_dyn_keep_states != 0) {
1412                                 rule = V_layer3_chain.default_rule;
1413                                 info->f_pos = V_layer3_chain.n_rules - 1;
1414                         } else {
1415                                 rule = NULL;
1416                                 info->direction = MATCH_NONE;
1417                                 DYN_DEBUG("rule %p  [%u, %u] is considered "
1418                                     "invalid in data %p", rule, data->ruleid,
1419                                     data->rulenum, data);
1420                                 /* info->f_pos doesn't matter here. */
1421                         }
1422                 } else
1423                         info->f_pos = data->f_pos;
1424         }
1425         DYNSTATE_CRITICAL_EXIT();
1426 #if 0
1427         /*
1428          * Return MATCH_NONE if parent rule is in disabled set.
1429          * This will lead to creation of new similar state that
1430          * will be added into head of this bucket.
1431          *
1432          * XXXAE: we need to be able update state's set when parent
1433          *        rule set is changed.
1434          */
1435         if (rule != NULL && (V_set_disable & (1 << rule->set))) {
1436                 rule = NULL;
1437                 info->direction = MATCH_NONE;
1438         }
1439 #endif
1440         return (rule);
1441 }
1442
1443 static struct dyn_parent *
1444 dyn_alloc_parent(void *parent, uint32_t ruleid, uint16_t rulenum,
1445     uint8_t set, uint32_t hashval)
1446 {
1447         struct dyn_parent *limit;
1448
1449         limit = uma_zalloc(V_dyn_parent_zone, M_NOWAIT | M_ZERO);
1450         if (limit == NULL) {
1451                 if (last_log != time_uptime) {
1452                         last_log = time_uptime;
1453                         log(LOG_DEBUG,
1454                             "ipfw: Cannot allocate parent dynamic state, "
1455                             "consider increasing "
1456                             "net.inet.ip.fw.dyn_parent_max\n");
1457                 }
1458                 return (NULL);
1459         }
1460
1461         limit->parent = parent;
1462         limit->ruleid = ruleid;
1463         limit->rulenum = rulenum;
1464         limit->set = set;
1465         limit->hashval = hashval;
1466         limit->expire = time_uptime + V_dyn_short_lifetime;
1467         return (limit);
1468 }
1469
1470 static struct dyn_data *
1471 dyn_alloc_dyndata(void *parent, uint32_t ruleid, uint16_t rulenum,
1472     uint8_t set, const struct ipfw_flow_id *pkt, const void *ulp, int pktlen,
1473     uint32_t hashval, uint16_t fibnum)
1474 {
1475         struct dyn_data *data;
1476
1477         data = uma_zalloc(V_dyn_data_zone, M_NOWAIT | M_ZERO);
1478         if (data == NULL) {
1479                 if (last_log != time_uptime) {
1480                         last_log = time_uptime;
1481                         log(LOG_DEBUG,
1482                             "ipfw: Cannot allocate dynamic state, "
1483                             "consider increasing net.inet.ip.fw.dyn_max\n");
1484                 }
1485                 return (NULL);
1486         }
1487
1488         data->parent = parent;
1489         data->ruleid = ruleid;
1490         data->rulenum = rulenum;
1491         data->set = set;
1492         data->fibnum = fibnum;
1493         data->hashval = hashval;
1494         data->expire = time_uptime + V_dyn_syn_lifetime;
1495         dyn_update_proto_state(data, pkt, ulp, pktlen, MATCH_FORWARD);
1496         return (data);
1497 }
1498
1499 static struct dyn_ipv4_state *
1500 dyn_alloc_ipv4_state(const struct ipfw_flow_id *pkt, uint16_t kidx,
1501     uint8_t type)
1502 {
1503         struct dyn_ipv4_state *s;
1504
1505         s = uma_zalloc(V_dyn_ipv4_zone, M_NOWAIT | M_ZERO);
1506         if (s == NULL)
1507                 return (NULL);
1508
1509         s->type = type;
1510         s->kidx = kidx;
1511         s->proto = pkt->proto;
1512         s->sport = pkt->src_port;
1513         s->dport = pkt->dst_port;
1514         s->src = pkt->src_ip;
1515         s->dst = pkt->dst_ip;
1516         return (s);
1517 }
1518
1519 /*
1520  * Add IPv4 parent state.
1521  * Returns pointer to parent state. When it is not NULL we are in
1522  * critical section and pointer protected by hazard pointer.
1523  * When some error occurs, it returns NULL and exit from critical section
1524  * is not needed.
1525  */
1526 static struct dyn_ipv4_state *
1527 dyn_add_ipv4_parent(void *rule, uint32_t ruleid, uint16_t rulenum,
1528     uint8_t set, const struct ipfw_flow_id *pkt, uint32_t hashval,
1529     uint32_t version, uint16_t kidx)
1530 {
1531         struct dyn_ipv4_state *s;
1532         struct dyn_parent *limit;
1533         uint32_t bucket;
1534
1535         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1536         DYN_BUCKET_LOCK(bucket);
1537         if (version != DYN_BUCKET_VERSION(bucket, ipv4_parent_add)) {
1538                 /*
1539                  * Bucket version has been changed since last lookup,
1540                  * do lookup again to be sure that state does not exist.
1541                  */
1542                 s = dyn_lookup_ipv4_parent_locked(pkt, rule, ruleid,
1543                     rulenum, bucket);
1544                 if (s != NULL) {
1545                         /*
1546                          * Simultaneous thread has already created this
1547                          * state. Just return it.
1548                          */
1549                         DYNSTATE_CRITICAL_ENTER();
1550                         DYNSTATE_PROTECT(s);
1551                         DYN_BUCKET_UNLOCK(bucket);
1552                         return (s);
1553                 }
1554         }
1555
1556         limit = dyn_alloc_parent(rule, ruleid, rulenum, set, hashval);
1557         if (limit == NULL) {
1558                 DYN_BUCKET_UNLOCK(bucket);
1559                 return (NULL);
1560         }
1561
1562         s = dyn_alloc_ipv4_state(pkt, kidx, O_LIMIT_PARENT);
1563         if (s == NULL) {
1564                 DYN_BUCKET_UNLOCK(bucket);
1565                 uma_zfree(V_dyn_parent_zone, limit);
1566                 return (NULL);
1567         }
1568
1569         s->limit = limit;
1570         CK_SLIST_INSERT_HEAD(&V_dyn_ipv4_parent[bucket], s, entry);
1571         DYN_COUNT_INC(dyn_parent_count);
1572         DYN_BUCKET_VERSION_BUMP(bucket, ipv4_parent_add);
1573         DYNSTATE_CRITICAL_ENTER();
1574         DYNSTATE_PROTECT(s);
1575         DYN_BUCKET_UNLOCK(bucket);
1576         return (s);
1577 }
1578
1579 static int
1580 dyn_add_ipv4_state(void *parent, uint32_t ruleid, uint16_t rulenum,
1581     uint8_t set, const struct ipfw_flow_id *pkt, const void *ulp, int pktlen,
1582     uint32_t hashval, struct ipfw_dyn_info *info, uint16_t fibnum,
1583     uint16_t kidx, uint8_t type)
1584 {
1585         struct dyn_ipv4_state *s;
1586         void *data;
1587         uint32_t bucket;
1588
1589         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1590         DYN_BUCKET_LOCK(bucket);
1591         if (info->direction == MATCH_UNKNOWN ||
1592             info->kidx != kidx ||
1593             info->hashval != hashval ||
1594             info->version != DYN_BUCKET_VERSION(bucket, ipv4_add)) {
1595                 /*
1596                  * Bucket version has been changed since last lookup,
1597                  * do lookup again to be sure that state does not exist.
1598                  */
1599                 if (dyn_lookup_ipv4_state_locked(pkt, ulp, pktlen,
1600                     bucket, kidx) != 0) {
1601                         DYN_BUCKET_UNLOCK(bucket);
1602                         return (EEXIST);
1603                 }
1604         }
1605
1606         data = dyn_alloc_dyndata(parent, ruleid, rulenum, set, pkt, ulp,
1607             pktlen, hashval, fibnum);
1608         if (data == NULL) {
1609                 DYN_BUCKET_UNLOCK(bucket);
1610                 return (ENOMEM);
1611         }
1612
1613         s = dyn_alloc_ipv4_state(pkt, kidx, type);
1614         if (s == NULL) {
1615                 DYN_BUCKET_UNLOCK(bucket);
1616                 uma_zfree(V_dyn_data_zone, data);
1617                 return (ENOMEM);
1618         }
1619
1620         s->data = data;
1621         CK_SLIST_INSERT_HEAD(&V_dyn_ipv4[bucket], s, entry);
1622         DYN_COUNT_INC(dyn_count);
1623         DYN_BUCKET_VERSION_BUMP(bucket, ipv4_add);
1624         DYN_BUCKET_UNLOCK(bucket);
1625         return (0);
1626 }
1627
1628 #ifdef INET6
1629 static struct dyn_ipv6_state *
1630 dyn_alloc_ipv6_state(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1631     uint16_t kidx, uint8_t type)
1632 {
1633         struct dyn_ipv6_state *s;
1634
1635         s = uma_zalloc(V_dyn_ipv6_zone, M_NOWAIT | M_ZERO);
1636         if (s == NULL)
1637                 return (NULL);
1638
1639         s->type = type;
1640         s->kidx = kidx;
1641         s->zoneid = zoneid;
1642         s->proto = pkt->proto;
1643         s->sport = pkt->src_port;
1644         s->dport = pkt->dst_port;
1645         s->src = pkt->src_ip6;
1646         s->dst = pkt->dst_ip6;
1647         return (s);
1648 }
1649
1650 /*
1651  * Add IPv6 parent state.
1652  * Returns pointer to parent state. When it is not NULL we are in
1653  * critical section and pointer protected by hazard pointer.
1654  * When some error occurs, it return NULL and exit from critical section
1655  * is not needed.
1656  */
1657 static struct dyn_ipv6_state *
1658 dyn_add_ipv6_parent(void *rule, uint32_t ruleid, uint16_t rulenum,
1659     uint8_t set, const struct ipfw_flow_id *pkt, uint32_t zoneid,
1660     uint32_t hashval, uint32_t version, uint16_t kidx)
1661 {
1662         struct dyn_ipv6_state *s;
1663         struct dyn_parent *limit;
1664         uint32_t bucket;
1665
1666         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1667         DYN_BUCKET_LOCK(bucket);
1668         if (version != DYN_BUCKET_VERSION(bucket, ipv6_parent_add)) {
1669                 /*
1670                  * Bucket version has been changed since last lookup,
1671                  * do lookup again to be sure that state does not exist.
1672                  */
1673                 s = dyn_lookup_ipv6_parent_locked(pkt, zoneid, rule, ruleid,
1674                     rulenum, bucket);
1675                 if (s != NULL) {
1676                         /*
1677                          * Simultaneous thread has already created this
1678                          * state. Just return it.
1679                          */
1680                         DYNSTATE_CRITICAL_ENTER();
1681                         DYNSTATE_PROTECT(s);
1682                         DYN_BUCKET_UNLOCK(bucket);
1683                         return (s);
1684                 }
1685         }
1686
1687         limit = dyn_alloc_parent(rule, ruleid, rulenum, set, hashval);
1688         if (limit == NULL) {
1689                 DYN_BUCKET_UNLOCK(bucket);
1690                 return (NULL);
1691         }
1692
1693         s = dyn_alloc_ipv6_state(pkt, zoneid, kidx, O_LIMIT_PARENT);
1694         if (s == NULL) {
1695                 DYN_BUCKET_UNLOCK(bucket);
1696                 uma_zfree(V_dyn_parent_zone, limit);
1697                 return (NULL);
1698         }
1699
1700         s->limit = limit;
1701         CK_SLIST_INSERT_HEAD(&V_dyn_ipv6_parent[bucket], s, entry);
1702         DYN_COUNT_INC(dyn_parent_count);
1703         DYN_BUCKET_VERSION_BUMP(bucket, ipv6_parent_add);
1704         DYNSTATE_CRITICAL_ENTER();
1705         DYNSTATE_PROTECT(s);
1706         DYN_BUCKET_UNLOCK(bucket);
1707         return (s);
1708 }
1709
1710 static int
1711 dyn_add_ipv6_state(void *parent, uint32_t ruleid, uint16_t rulenum,
1712     uint8_t set, const struct ipfw_flow_id *pkt, uint32_t zoneid,
1713     const void *ulp, int pktlen, uint32_t hashval, struct ipfw_dyn_info *info,
1714     uint16_t fibnum, uint16_t kidx, uint8_t type)
1715 {
1716         struct dyn_ipv6_state *s;
1717         struct dyn_data *data;
1718         uint32_t bucket;
1719
1720         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1721         DYN_BUCKET_LOCK(bucket);
1722         if (info->direction == MATCH_UNKNOWN ||
1723             info->kidx != kidx ||
1724             info->hashval != hashval ||
1725             info->version != DYN_BUCKET_VERSION(bucket, ipv6_add)) {
1726                 /*
1727                  * Bucket version has been changed since last lookup,
1728                  * do lookup again to be sure that state does not exist.
1729                  */
1730                 if (dyn_lookup_ipv6_state_locked(pkt, zoneid, ulp, pktlen,
1731                     bucket, kidx) != 0) {
1732                         DYN_BUCKET_UNLOCK(bucket);
1733                         return (EEXIST);
1734                 }
1735         }
1736
1737         data = dyn_alloc_dyndata(parent, ruleid, rulenum, set, pkt, ulp,
1738             pktlen, hashval, fibnum);
1739         if (data == NULL) {
1740                 DYN_BUCKET_UNLOCK(bucket);
1741                 return (ENOMEM);
1742         }
1743
1744         s = dyn_alloc_ipv6_state(pkt, zoneid, kidx, type);
1745         if (s == NULL) {
1746                 DYN_BUCKET_UNLOCK(bucket);
1747                 uma_zfree(V_dyn_data_zone, data);
1748                 return (ENOMEM);
1749         }
1750
1751         s->data = data;
1752         CK_SLIST_INSERT_HEAD(&V_dyn_ipv6[bucket], s, entry);
1753         DYN_COUNT_INC(dyn_count);
1754         DYN_BUCKET_VERSION_BUMP(bucket, ipv6_add);
1755         DYN_BUCKET_UNLOCK(bucket);
1756         return (0);
1757 }
1758 #endif /* INET6 */
1759
1760 static void *
1761 dyn_get_parent_state(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1762     struct ip_fw *rule, uint32_t hashval, uint32_t limit, uint16_t kidx)
1763 {
1764         char sbuf[24];
1765         struct dyn_parent *p;
1766         void *ret;
1767         uint32_t bucket, version;
1768
1769         p = NULL;
1770         ret = NULL;
1771         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1772         DYNSTATE_CRITICAL_ENTER();
1773         if (IS_IP4_FLOW_ID(pkt)) {
1774                 struct dyn_ipv4_state *s;
1775
1776                 version = DYN_BUCKET_VERSION(bucket, ipv4_parent_add);
1777                 s = dyn_lookup_ipv4_parent(pkt, rule, rule->id,
1778                     rule->rulenum, bucket);
1779                 if (s == NULL) {
1780                         /*
1781                          * Exit from critical section because dyn_add_parent()
1782                          * will acquire bucket lock.
1783                          */
1784                         DYNSTATE_CRITICAL_EXIT();
1785
1786                         s = dyn_add_ipv4_parent(rule, rule->id,
1787                             rule->rulenum, rule->set, pkt, hashval,
1788                             version, kidx);
1789                         if (s == NULL)
1790                                 return (NULL);
1791                         /* Now we are in critical section again. */
1792                 }
1793                 ret = s;
1794                 p = s->limit;
1795         }
1796 #ifdef INET6
1797         else if (IS_IP6_FLOW_ID(pkt)) {
1798                 struct dyn_ipv6_state *s;
1799
1800                 version = DYN_BUCKET_VERSION(bucket, ipv6_parent_add);
1801                 s = dyn_lookup_ipv6_parent(pkt, zoneid, rule, rule->id,
1802                     rule->rulenum, bucket);
1803                 if (s == NULL) {
1804                         /*
1805                          * Exit from critical section because dyn_add_parent()
1806                          * can acquire bucket mutex.
1807                          */
1808                         DYNSTATE_CRITICAL_EXIT();
1809
1810                         s = dyn_add_ipv6_parent(rule, rule->id,
1811                             rule->rulenum, rule->set, pkt, zoneid, hashval,
1812                             version, kidx);
1813                         if (s == NULL)
1814                                 return (NULL);
1815                         /* Now we are in critical section again. */
1816                 }
1817                 ret = s;
1818                 p = s->limit;
1819         }
1820 #endif
1821         else {
1822                 DYNSTATE_CRITICAL_EXIT();
1823                 return (NULL);
1824         }
1825
1826         /* Check the limit */
1827         if (DPARENT_COUNT(p) >= limit) {
1828                 DYNSTATE_CRITICAL_EXIT();
1829                 if (V_fw_verbose && last_log != time_uptime) {
1830                         last_log = time_uptime;
1831                         snprintf(sbuf, sizeof(sbuf), "%u drop session",
1832                             rule->rulenum);
1833                         print_dyn_rule_flags(pkt, O_LIMIT,
1834                             LOG_SECURITY | LOG_DEBUG, sbuf,
1835                             "too many entries");
1836                 }
1837                 return (NULL);
1838         }
1839
1840         /* Take new session into account. */
1841         DPARENT_COUNT_INC(p);
1842         /*
1843          * We must exit from critical section because the following code
1844          * can acquire bucket mutex.
1845          * We rely on the the 'count' field. The state will not expire
1846          * until it has some child states, i.e. 'count' field is not zero.
1847          * Return state pointer, it will be used by child states as parent.
1848          */
1849         DYNSTATE_CRITICAL_EXIT();
1850         return (ret);
1851 }
1852
1853 static int
1854 dyn_install_state(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1855     uint16_t fibnum, const void *ulp, int pktlen, void *rule,
1856     uint32_t ruleid, uint16_t rulenum, uint8_t set,
1857     struct ipfw_dyn_info *info, uint32_t limit, uint16_t limit_mask,
1858     uint16_t kidx, uint8_t type)
1859 {
1860         struct ipfw_flow_id id;
1861         uint32_t hashval, parent_hashval;
1862         int ret;
1863
1864         MPASS(type == O_LIMIT || type == O_KEEP_STATE);
1865
1866         if (type == O_LIMIT) {
1867                 /* Create masked flow id and calculate bucket */
1868                 id.addr_type = pkt->addr_type;
1869                 id.proto = pkt->proto;
1870                 id.fib = fibnum; /* unused */
1871                 id.src_port = (limit_mask & DYN_SRC_PORT) ?
1872                     pkt->src_port: 0;
1873                 id.dst_port = (limit_mask & DYN_DST_PORT) ?
1874                     pkt->dst_port: 0;
1875                 if (IS_IP4_FLOW_ID(pkt)) {
1876                         id.src_ip = (limit_mask & DYN_SRC_ADDR) ?
1877                             pkt->src_ip: 0;
1878                         id.dst_ip = (limit_mask & DYN_DST_ADDR) ?
1879                             pkt->dst_ip: 0;
1880                 }
1881 #ifdef INET6
1882                 else if (IS_IP6_FLOW_ID(pkt)) {
1883                         if (limit_mask & DYN_SRC_ADDR)
1884                                 id.src_ip6 = pkt->src_ip6;
1885                         else
1886                                 memset(&id.src_ip6, 0, sizeof(id.src_ip6));
1887                         if (limit_mask & DYN_DST_ADDR)
1888                                 id.dst_ip6 = pkt->dst_ip6;
1889                         else
1890                                 memset(&id.dst_ip6, 0, sizeof(id.dst_ip6));
1891                 }
1892 #endif
1893                 else
1894                         return (EAFNOSUPPORT);
1895
1896                 parent_hashval = hash_parent(&id, rule);
1897                 rule = dyn_get_parent_state(&id, zoneid, rule, parent_hashval,
1898                     limit, kidx);
1899                 if (rule == NULL) {
1900 #if 0
1901                         if (V_fw_verbose && last_log != time_uptime) {
1902                                 last_log = time_uptime;
1903                                 snprintf(sbuf, sizeof(sbuf),
1904                                     "%u drop session", rule->rulenum);
1905                         print_dyn_rule_flags(pkt, O_LIMIT,
1906                             LOG_SECURITY | LOG_DEBUG, sbuf,
1907                             "too many entries");
1908                         }
1909 #endif
1910                         return (EACCES);
1911                 }
1912                 /*
1913                  * Limit is not reached, create new state.
1914                  * Now rule points to parent state.
1915                  */
1916         }
1917
1918         hashval = hash_packet(pkt);
1919         if (IS_IP4_FLOW_ID(pkt))
1920                 ret = dyn_add_ipv4_state(rule, ruleid, rulenum, set, pkt,
1921                     ulp, pktlen, hashval, info, fibnum, kidx, type);
1922 #ifdef INET6
1923         else if (IS_IP6_FLOW_ID(pkt))
1924                 ret = dyn_add_ipv6_state(rule, ruleid, rulenum, set, pkt,
1925                     zoneid, ulp, pktlen, hashval, info, fibnum, kidx, type);
1926 #endif /* INET6 */
1927         else
1928                 ret = EAFNOSUPPORT;
1929
1930         if (type == O_LIMIT) {
1931                 if (ret != 0) {
1932                         /*
1933                          * We failed to create child state for O_LIMIT
1934                          * opcode. Since we already counted it in the parent,
1935                          * we must revert counter back. The 'rule' points to
1936                          * parent state, use it to get dyn_parent.
1937                          *
1938                          * XXXAE: it should be safe to use 'rule' pointer
1939                          * without extra lookup, parent state is referenced
1940                          * and should not be freed.
1941                          */
1942                         if (IS_IP4_FLOW_ID(&id))
1943                                 DPARENT_COUNT_DEC(
1944                                     ((struct dyn_ipv4_state *)rule)->limit);
1945 #ifdef INET6
1946                         else if (IS_IP6_FLOW_ID(&id))
1947                                 DPARENT_COUNT_DEC(
1948                                     ((struct dyn_ipv6_state *)rule)->limit);
1949 #endif
1950                 }
1951         }
1952         /*
1953          * EEXIST means that simultaneous thread has created this
1954          * state. Consider this as success.
1955          *
1956          * XXXAE: should we invalidate 'info' content here?
1957          */
1958         if (ret == EEXIST)
1959                 return (0);
1960         return (ret);
1961 }
1962
1963 /*
1964  * Install dynamic state.
1965  *  chain - ipfw's instance;
1966  *  rule - the parent rule that installs the state;
1967  *  cmd - opcode that installs the state;
1968  *  args - ipfw arguments;
1969  *  ulp - upper level protocol header;
1970  *  pktlen - packet length;
1971  *  info - dynamic state lookup info;
1972  *  tablearg - tablearg id.
1973  *
1974  * Returns non-zero value (failure) if state is not installed because
1975  * of errors or because session limitations are enforced.
1976  */
1977 int
1978 ipfw_dyn_install_state(struct ip_fw_chain *chain, struct ip_fw *rule,
1979     const ipfw_insn_limit *cmd, const struct ip_fw_args *args,
1980     const void *ulp, int pktlen, struct ipfw_dyn_info *info,
1981     uint32_t tablearg)
1982 {
1983         uint32_t limit;
1984         uint16_t limit_mask;
1985
1986         if (cmd->o.opcode == O_LIMIT) {
1987                 limit = IP_FW_ARG_TABLEARG(chain, cmd->conn_limit, limit);
1988                 limit_mask = cmd->limit_mask;
1989         } else {
1990                 limit = 0;
1991                 limit_mask = 0;
1992         }
1993         return (dyn_install_state(&args->f_id,
1994 #ifdef INET6
1995             IS_IP6_FLOW_ID(&args->f_id) ? dyn_getscopeid(args):
1996 #endif
1997             0, M_GETFIB(args->m), ulp, pktlen, rule, rule->id, rule->rulenum,
1998             rule->set, info, limit, limit_mask, cmd->o.arg1, cmd->o.opcode));
1999 }
2000
2001 /*
2002  * Free safe to remove state entries from expired lists.
2003  */
2004 static void
2005 dyn_free_states(struct ip_fw_chain *chain)
2006 {
2007         struct dyn_ipv4_state *s4, *s4n;
2008 #ifdef INET6
2009         struct dyn_ipv6_state *s6, *s6n;
2010 #endif
2011         int cached_count, i;
2012
2013         /*
2014          * We keep pointers to objects that are in use on each CPU
2015          * in the per-cpu dyn_hp pointer. When object is going to be
2016          * removed, first of it is unlinked from the corresponding
2017          * list. This leads to changing of dyn_bucket_xxx_delver version.
2018          * Unlinked objects is placed into corresponding dyn_expired_xxx
2019          * list. Reader that is going to dereference object pointer checks
2020          * dyn_bucket_xxx_delver version before and after storing pointer
2021          * into dyn_hp. If version is the same, the object is protected
2022          * from freeing and it is safe to dereference. Othervise reader
2023          * tries to iterate list again from the beginning, but this object
2024          * now unlinked and thus will not be accessible.
2025          *
2026          * Copy dyn_hp pointers for each CPU into dyn_hp_cache array.
2027          * It does not matter that some pointer can be changed in
2028          * time while we are copying. We need to check, that objects
2029          * removed in the previous pass are not in use. And if dyn_hp
2030          * pointer does not contain it in the time when we are copying,
2031          * it will not appear there, because it is already unlinked.
2032          * And for new pointers we will not free objects that will be
2033          * unlinked in this pass.
2034          */
2035         cached_count = 0;
2036         CPU_FOREACH(i) {
2037                 dyn_hp_cache[cached_count] = DYNSTATE_GET(i);
2038                 if (dyn_hp_cache[cached_count] != NULL)
2039                         cached_count++;
2040         }
2041
2042         /*
2043          * Free expired states that are safe to free.
2044          * Check each entry from previous pass in the dyn_expired_xxx
2045          * list, if pointer to the object is in the dyn_hp_cache array,
2046          * keep it until next pass. Otherwise it is safe to free the
2047          * object.
2048          *
2049          * XXXAE: optimize this to use SLIST_REMOVE_AFTER.
2050          */
2051 #define DYN_FREE_STATES(s, next, name)          do {                    \
2052         s = SLIST_FIRST(&V_dyn_expired_ ## name);                       \
2053         while (s != NULL) {                                             \
2054                 next = SLIST_NEXT(s, expired);                          \
2055                 for (i = 0; i < cached_count; i++)                      \
2056                         if (dyn_hp_cache[i] == s)                       \
2057                                 break;                                  \
2058                 if (i == cached_count) {                                \
2059                         if (s->type == O_LIMIT_PARENT &&                \
2060                             s->limit->count != 0) {                     \
2061                                 s = next;                               \
2062                                 continue;                               \
2063                         }                                               \
2064                         SLIST_REMOVE(&V_dyn_expired_ ## name,           \
2065                             s, dyn_ ## name ## _state, expired);        \
2066                         if (s->type == O_LIMIT_PARENT)                  \
2067                                 uma_zfree(V_dyn_parent_zone, s->limit); \
2068                         else                                            \
2069                                 uma_zfree(V_dyn_data_zone, s->data);    \
2070                         uma_zfree(V_dyn_ ## name ## _zone, s);          \
2071                 }                                                       \
2072                 s = next;                                               \
2073         }                                                               \
2074 } while (0)
2075
2076         /*
2077          * Protect access to expired lists with DYN_EXPIRED_LOCK.
2078          * Userland can invoke ipfw_expire_dyn_states() to delete
2079          * specific states, this will lead to modification of expired
2080          * lists.
2081          *
2082          * XXXAE: do we need DYN_EXPIRED_LOCK? We can just use
2083          *        IPFW_UH_WLOCK to protect access to these lists.
2084          */
2085         DYN_EXPIRED_LOCK();
2086         DYN_FREE_STATES(s4, s4n, ipv4);
2087 #ifdef INET6
2088         DYN_FREE_STATES(s6, s6n, ipv6);
2089 #endif
2090         DYN_EXPIRED_UNLOCK();
2091 #undef DYN_FREE_STATES
2092 }
2093
2094 /*
2095  * Returns 1 when state is matched by specified range, otherwise returns 0.
2096  */
2097 static int
2098 dyn_match_range(uint16_t rulenum, uint8_t set, const ipfw_range_tlv *rt)
2099 {
2100
2101         MPASS(rt != NULL);
2102         /* flush all states */
2103         if (rt->flags & IPFW_RCFLAG_ALL)
2104                 return (1);
2105         if ((rt->flags & IPFW_RCFLAG_SET) != 0 && set != rt->set)
2106                 return (0);
2107         if ((rt->flags & IPFW_RCFLAG_RANGE) != 0 &&
2108             (rulenum < rt->start_rule || rulenum > rt->end_rule))
2109                 return (0);
2110         return (1);
2111 }
2112
2113 static int
2114 dyn_match_ipv4_state(struct dyn_ipv4_state *s, const ipfw_range_tlv *rt)
2115 {
2116
2117         if (s->type == O_LIMIT_PARENT)
2118                 return (dyn_match_range(s->limit->rulenum,
2119                     s->limit->set, rt));
2120
2121         if (s->type == O_LIMIT)
2122                 return (dyn_match_range(s->data->rulenum, s->data->set, rt));
2123
2124         if (V_dyn_keep_states == 0 &&
2125             dyn_match_range(s->data->rulenum, s->data->set, rt))
2126                 return (1);
2127
2128         return (0);
2129 }
2130
2131 #ifdef INET6
2132 static int
2133 dyn_match_ipv6_state(struct dyn_ipv6_state *s, const ipfw_range_tlv *rt)
2134 {
2135
2136         if (s->type == O_LIMIT_PARENT)
2137                 return (dyn_match_range(s->limit->rulenum,
2138                     s->limit->set, rt));
2139
2140         if (s->type == O_LIMIT)
2141                 return (dyn_match_range(s->data->rulenum, s->data->set, rt));
2142
2143         if (V_dyn_keep_states == 0 &&
2144             dyn_match_range(s->data->rulenum, s->data->set, rt))
2145                 return (1);
2146
2147         return (0);
2148 }
2149 #endif
2150
2151 /*
2152  * Unlink expired entries from states lists.
2153  * @rt can be used to specify the range of states for deletion.
2154  */
2155 static void
2156 dyn_expire_states(struct ip_fw_chain *chain, ipfw_range_tlv *rt)
2157 {
2158         struct dyn_ipv4_slist expired_ipv4;
2159 #ifdef INET6
2160         struct dyn_ipv6_slist expired_ipv6;
2161         struct dyn_ipv6_state *s6, *s6n, *s6p;
2162 #endif
2163         struct dyn_ipv4_state *s4, *s4n, *s4p;
2164         int bucket, removed, length, max_length;
2165
2166         /*
2167          * Unlink expired states from each bucket.
2168          * With acquired bucket lock iterate entries of each lists:
2169          * ipv4, ipv4_parent, ipv6, and ipv6_parent. Check expired time
2170          * and unlink entry from the list, link entry into temporary
2171          * expired_xxx lists then bump "del" bucket version.
2172          *
2173          * When an entry is removed, corresponding states counter is
2174          * decremented. If entry has O_LIMIT type, parent's reference
2175          * counter is decremented.
2176          *
2177          * NOTE: this function can be called from userspace context
2178          * when user deletes rules. In this case all matched states
2179          * will be forcedly unlinked. O_LIMIT_PARENT states will be kept
2180          * in the expired lists until reference counter become zero.
2181          */
2182 #define DYN_UNLINK_STATES(s, prev, next, exp, af, name, extra)  do {    \
2183         length = 0;                                                     \
2184         removed = 0;                                                    \
2185         prev = NULL;                                                    \
2186         s = CK_SLIST_FIRST(&V_dyn_ ## name [bucket]);                   \
2187         while (s != NULL) {                                             \
2188                 next = CK_SLIST_NEXT(s, entry);                         \
2189                 if ((TIME_LEQ((s)->exp, time_uptime) && extra) ||       \
2190                     (rt != NULL && dyn_match_ ## af ## _state(s, rt))) {\
2191                         if (prev != NULL)                               \
2192                                 CK_SLIST_REMOVE_AFTER(prev, entry);     \
2193                         else                                            \
2194                                 CK_SLIST_REMOVE_HEAD(                   \
2195                                     &V_dyn_ ## name [bucket], entry);   \
2196                         removed++;                                      \
2197                         SLIST_INSERT_HEAD(&expired_ ## af, s, expired); \
2198                         if (s->type == O_LIMIT_PARENT)                  \
2199                                 DYN_COUNT_DEC(dyn_parent_count);        \
2200                         else {                                          \
2201                                 DYN_COUNT_DEC(dyn_count);               \
2202                                 if (s->type == O_LIMIT) {               \
2203                                         s = s->data->parent;            \
2204                                         DPARENT_COUNT_DEC(s->limit);    \
2205                                 }                                       \
2206                         }                                               \
2207                 } else {                                                \
2208                         prev = s;                                       \
2209                         length++;                                       \
2210                 }                                                       \
2211                 s = next;                                               \
2212         }                                                               \
2213         if (removed != 0)                                               \
2214                 DYN_BUCKET_VERSION_BUMP(bucket, name ## _del);          \
2215         if (length > max_length)                                \
2216                 max_length = length;                            \
2217 } while (0)
2218
2219         SLIST_INIT(&expired_ipv4);
2220 #ifdef INET6
2221         SLIST_INIT(&expired_ipv6);
2222 #endif
2223         max_length = 0;
2224         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
2225                 DYN_BUCKET_LOCK(bucket);
2226                 DYN_UNLINK_STATES(s4, s4p, s4n, data->expire, ipv4, ipv4, 1);
2227                 DYN_UNLINK_STATES(s4, s4p, s4n, limit->expire, ipv4,
2228                     ipv4_parent, (s4->limit->count == 0));
2229 #ifdef INET6
2230                 DYN_UNLINK_STATES(s6, s6p, s6n, data->expire, ipv6, ipv6, 1);
2231                 DYN_UNLINK_STATES(s6, s6p, s6n, limit->expire, ipv6,
2232                     ipv6_parent, (s6->limit->count == 0));
2233 #endif
2234                 DYN_BUCKET_UNLOCK(bucket);
2235         }
2236         /* Update curr_max_length for statistics. */
2237         V_curr_max_length = max_length;
2238         /*
2239          * Concatenate temporary lists with global expired lists.
2240          */
2241         DYN_EXPIRED_LOCK();
2242         SLIST_CONCAT(&V_dyn_expired_ipv4, &expired_ipv4,
2243             dyn_ipv4_state, expired);
2244 #ifdef INET6
2245         SLIST_CONCAT(&V_dyn_expired_ipv6, &expired_ipv6,
2246             dyn_ipv6_state, expired);
2247 #endif
2248         DYN_EXPIRED_UNLOCK();
2249 #undef DYN_UNLINK_STATES
2250 #undef DYN_UNREF_STATES
2251 }
2252
2253 static struct mbuf *
2254 dyn_mgethdr(int len, uint16_t fibnum)
2255 {
2256         struct mbuf *m;
2257
2258         m = m_gethdr(M_NOWAIT, MT_DATA);
2259         if (m == NULL)
2260                 return (NULL);
2261 #ifdef MAC
2262         mac_netinet_firewall_send(m);
2263 #endif
2264         M_SETFIB(m, fibnum);
2265         m->m_data += max_linkhdr;
2266         m->m_flags |= M_SKIP_FIREWALL;
2267         m->m_len = m->m_pkthdr.len = len;
2268         bzero(m->m_data, len);
2269         return (m);
2270 }
2271
2272 static void
2273 dyn_make_keepalive_ipv4(struct mbuf *m, in_addr_t src, in_addr_t dst,
2274     uint32_t seq, uint32_t ack, uint16_t sport, uint16_t dport)
2275 {
2276         struct tcphdr *tcp;
2277         struct ip *ip;
2278
2279         ip = mtod(m, struct ip *);
2280         ip->ip_v = 4;
2281         ip->ip_hl = sizeof(*ip) >> 2;
2282         ip->ip_tos = IPTOS_LOWDELAY;
2283         ip->ip_len = htons(m->m_len);
2284         ip->ip_off |= htons(IP_DF);
2285         ip->ip_ttl = V_ip_defttl;
2286         ip->ip_p = IPPROTO_TCP;
2287         ip->ip_src.s_addr = htonl(src);
2288         ip->ip_dst.s_addr = htonl(dst);
2289
2290         tcp = mtodo(m, sizeof(struct ip));
2291         tcp->th_sport = htons(sport);
2292         tcp->th_dport = htons(dport);
2293         tcp->th_off = sizeof(struct tcphdr) >> 2;
2294         tcp->th_seq = htonl(seq);
2295         tcp->th_ack = htonl(ack);
2296         tcp->th_flags = TH_ACK;
2297         tcp->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
2298             htons(sizeof(struct tcphdr) + IPPROTO_TCP));
2299
2300         m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
2301         m->m_pkthdr.csum_flags = CSUM_TCP;
2302 }
2303
2304 static void
2305 dyn_enqueue_keepalive_ipv4(struct mbufq *q, const struct dyn_ipv4_state *s)
2306 {
2307         struct mbuf *m;
2308
2309         if ((s->data->state & ACK_FWD) == 0 && s->data->ack_fwd > 0) {
2310                 m = dyn_mgethdr(sizeof(struct ip) + sizeof(struct tcphdr),
2311                     s->data->fibnum);
2312                 if (m != NULL) {
2313                         dyn_make_keepalive_ipv4(m, s->dst, s->src,
2314                             s->data->ack_fwd - 1, s->data->ack_rev,
2315                             s->dport, s->sport);
2316                         if (mbufq_enqueue(q, m)) {
2317                                 m_freem(m);
2318                                 log(LOG_DEBUG, "ipfw: limit for IPv4 "
2319                                     "keepalive queue is reached.\n");
2320                                 return;
2321                         }
2322                 }
2323         }
2324
2325         if ((s->data->state & ACK_REV) == 0 && s->data->ack_rev > 0) {
2326                 m = dyn_mgethdr(sizeof(struct ip) + sizeof(struct tcphdr),
2327                     s->data->fibnum);
2328                 if (m != NULL) {
2329                         dyn_make_keepalive_ipv4(m, s->src, s->dst,
2330                             s->data->ack_rev - 1, s->data->ack_fwd,
2331                             s->sport, s->dport);
2332                         if (mbufq_enqueue(q, m)) {
2333                                 m_freem(m);
2334                                 log(LOG_DEBUG, "ipfw: limit for IPv4 "
2335                                     "keepalive queue is reached.\n");
2336                                 return;
2337                         }
2338                 }
2339         }
2340 }
2341
2342 /*
2343  * Prepare and send keep-alive packets.
2344  */
2345 static void
2346 dyn_send_keepalive_ipv4(struct ip_fw_chain *chain)
2347 {
2348         struct mbufq q;
2349         struct mbuf *m;
2350         struct dyn_ipv4_state *s;
2351         uint32_t bucket;
2352
2353         mbufq_init(&q, DYN_KEEPALIVE_MAXQ);
2354         IPFW_UH_RLOCK(chain);
2355         /*
2356          * It is safe to not use hazard pointer and just do lockless
2357          * access to the lists, because states entries can not be deleted
2358          * while we hold IPFW_UH_RLOCK.
2359          */
2360         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
2361                 CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) {
2362                         /*
2363                          * Only established TCP connections that will
2364                          * become expired withing dyn_keepalive_interval.
2365                          */
2366                         if (s->proto != IPPROTO_TCP ||
2367                             (s->data->state & BOTH_SYN) != BOTH_SYN ||
2368                             TIME_LEQ(time_uptime + V_dyn_keepalive_interval,
2369                                 s->data->expire))
2370                                 continue;
2371                         dyn_enqueue_keepalive_ipv4(&q, s);
2372                 }
2373         }
2374         IPFW_UH_RUNLOCK(chain);
2375         while ((m = mbufq_dequeue(&q)) != NULL)
2376                 ip_output(m, NULL, NULL, 0, NULL, NULL);
2377 }
2378
2379 #ifdef INET6
2380 static void
2381 dyn_make_keepalive_ipv6(struct mbuf *m, const struct in6_addr *src,
2382     const struct in6_addr *dst, uint32_t zoneid, uint32_t seq, uint32_t ack,
2383     uint16_t sport, uint16_t dport)
2384 {
2385         struct tcphdr *tcp;
2386         struct ip6_hdr *ip6;
2387
2388         ip6 = mtod(m, struct ip6_hdr *);
2389         ip6->ip6_vfc |= IPV6_VERSION;
2390         ip6->ip6_plen = htons(sizeof(struct tcphdr));
2391         ip6->ip6_nxt = IPPROTO_TCP;
2392         ip6->ip6_hlim = IPV6_DEFHLIM;
2393         ip6->ip6_src = *src;
2394         if (IN6_IS_ADDR_LINKLOCAL(src))
2395                 ip6->ip6_src.s6_addr16[1] = htons(zoneid & 0xffff);
2396         ip6->ip6_dst = *dst;
2397         if (IN6_IS_ADDR_LINKLOCAL(dst))
2398                 ip6->ip6_dst.s6_addr16[1] = htons(zoneid & 0xffff);
2399
2400         tcp = mtodo(m, sizeof(struct ip6_hdr));
2401         tcp->th_sport = htons(sport);
2402         tcp->th_dport = htons(dport);
2403         tcp->th_off = sizeof(struct tcphdr) >> 2;
2404         tcp->th_seq = htonl(seq);
2405         tcp->th_ack = htonl(ack);
2406         tcp->th_flags = TH_ACK;
2407         tcp->th_sum = in6_cksum_pseudo(ip6, sizeof(struct tcphdr),
2408             IPPROTO_TCP, 0);
2409
2410         m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
2411         m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
2412 }
2413
2414 static void
2415 dyn_enqueue_keepalive_ipv6(struct mbufq *q, const struct dyn_ipv6_state *s)
2416 {
2417         struct mbuf *m;
2418
2419         if ((s->data->state & ACK_FWD) == 0 && s->data->ack_fwd > 0) {
2420                 m = dyn_mgethdr(sizeof(struct ip6_hdr) +
2421                     sizeof(struct tcphdr), s->data->fibnum);
2422                 if (m != NULL) {
2423                         dyn_make_keepalive_ipv6(m, &s->dst, &s->src,
2424                             s->zoneid, s->data->ack_fwd - 1, s->data->ack_rev,
2425                             s->dport, s->sport);
2426                         if (mbufq_enqueue(q, m)) {
2427                                 m_freem(m);
2428                                 log(LOG_DEBUG, "ipfw: limit for IPv6 "
2429                                     "keepalive queue is reached.\n");
2430                                 return;
2431                         }
2432                 }
2433         }
2434
2435         if ((s->data->state & ACK_REV) == 0 && s->data->ack_rev > 0) {
2436                 m = dyn_mgethdr(sizeof(struct ip6_hdr) +
2437                     sizeof(struct tcphdr), s->data->fibnum);
2438                 if (m != NULL) {
2439                         dyn_make_keepalive_ipv6(m, &s->src, &s->dst,
2440                             s->zoneid, s->data->ack_rev - 1, s->data->ack_fwd,
2441                             s->sport, s->dport);
2442                         if (mbufq_enqueue(q, m)) {
2443                                 m_freem(m);
2444                                 log(LOG_DEBUG, "ipfw: limit for IPv6 "
2445                                     "keepalive queue is reached.\n");
2446                                 return;
2447                         }
2448                 }
2449         }
2450 }
2451
2452 static void
2453 dyn_send_keepalive_ipv6(struct ip_fw_chain *chain)
2454 {
2455         struct mbufq q;
2456         struct mbuf *m;
2457         struct dyn_ipv6_state *s;
2458         uint32_t bucket;
2459
2460         mbufq_init(&q, DYN_KEEPALIVE_MAXQ);
2461         IPFW_UH_RLOCK(chain);
2462         /*
2463          * It is safe to not use hazard pointer and just do lockless
2464          * access to the lists, because states entries can not be deleted
2465          * while we hold IPFW_UH_RLOCK.
2466          */
2467         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
2468                 CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) {
2469                         /*
2470                          * Only established TCP connections that will
2471                          * become expired withing dyn_keepalive_interval.
2472                          */
2473                         if (s->proto != IPPROTO_TCP ||
2474                             (s->data->state & BOTH_SYN) != BOTH_SYN ||
2475                             TIME_LEQ(time_uptime + V_dyn_keepalive_interval,
2476                                 s->data->expire))
2477                                 continue;
2478                         dyn_enqueue_keepalive_ipv6(&q, s);
2479                 }
2480         }
2481         IPFW_UH_RUNLOCK(chain);
2482         while ((m = mbufq_dequeue(&q)) != NULL)
2483                 ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
2484 }
2485 #endif /* INET6 */
2486
2487 static void
2488 dyn_grow_hashtable(struct ip_fw_chain *chain, uint32_t new)
2489 {
2490 #ifdef INET6
2491         struct dyn_ipv6ck_slist *ipv6, *ipv6_parent;
2492         uint32_t *ipv6_add, *ipv6_del, *ipv6_parent_add, *ipv6_parent_del;
2493         struct dyn_ipv6_state *s6;
2494 #endif
2495         struct dyn_ipv4ck_slist *ipv4, *ipv4_parent;
2496         uint32_t *ipv4_add, *ipv4_del, *ipv4_parent_add, *ipv4_parent_del;
2497         struct dyn_ipv4_state *s4;
2498         struct mtx *bucket_lock;
2499         void *tmp;
2500         uint32_t bucket;
2501
2502         MPASS(powerof2(new));
2503         DYN_DEBUG("grow hash size %u -> %u", V_curr_dyn_buckets, new);
2504         /*
2505          * Allocate and initialize new lists.
2506          * XXXAE: on memory pressure this can disable callout timer.
2507          */
2508         bucket_lock = malloc(new * sizeof(struct mtx), M_IPFW,
2509             M_WAITOK | M_ZERO);
2510         ipv4 = malloc(new * sizeof(struct dyn_ipv4ck_slist), M_IPFW,
2511             M_WAITOK | M_ZERO);
2512         ipv4_parent = malloc(new * sizeof(struct dyn_ipv4ck_slist), M_IPFW,
2513             M_WAITOK | M_ZERO);
2514         ipv4_add = malloc(new * sizeof(uint32_t), M_IPFW, M_WAITOK | M_ZERO);
2515         ipv4_del = malloc(new * sizeof(uint32_t), M_IPFW, M_WAITOK | M_ZERO);
2516         ipv4_parent_add = malloc(new * sizeof(uint32_t), M_IPFW,
2517             M_WAITOK | M_ZERO);
2518         ipv4_parent_del = malloc(new * sizeof(uint32_t), M_IPFW,
2519             M_WAITOK | M_ZERO);
2520 #ifdef INET6
2521         ipv6 = malloc(new * sizeof(struct dyn_ipv6ck_slist), M_IPFW,
2522             M_WAITOK | M_ZERO);
2523         ipv6_parent = malloc(new * sizeof(struct dyn_ipv6ck_slist), M_IPFW,
2524             M_WAITOK | M_ZERO);
2525         ipv6_add = malloc(new * sizeof(uint32_t), M_IPFW, M_WAITOK | M_ZERO);
2526         ipv6_del = malloc(new * sizeof(uint32_t), M_IPFW, M_WAITOK | M_ZERO);
2527         ipv6_parent_add = malloc(new * sizeof(uint32_t), M_IPFW,
2528             M_WAITOK | M_ZERO);
2529         ipv6_parent_del = malloc(new * sizeof(uint32_t), M_IPFW,
2530             M_WAITOK | M_ZERO);
2531 #endif
2532         for (bucket = 0; bucket < new; bucket++) {
2533                 DYN_BUCKET_LOCK_INIT(bucket_lock, bucket);
2534                 CK_SLIST_INIT(&ipv4[bucket]);
2535                 CK_SLIST_INIT(&ipv4_parent[bucket]);
2536 #ifdef INET6
2537                 CK_SLIST_INIT(&ipv6[bucket]);
2538                 CK_SLIST_INIT(&ipv6_parent[bucket]);
2539 #endif
2540         }
2541
2542 #define DYN_RELINK_STATES(s, hval, i, head, ohead)      do {            \
2543         while ((s = CK_SLIST_FIRST(&V_dyn_ ## ohead[i])) != NULL) {     \
2544                 CK_SLIST_REMOVE_HEAD(&V_dyn_ ## ohead[i], entry);       \
2545                 CK_SLIST_INSERT_HEAD(&head[DYN_BUCKET(s->hval, new)],   \
2546                     s, entry);                                          \
2547         }                                                               \
2548 } while (0)
2549         /*
2550          * Prevent rules changing from userland.
2551          */
2552         IPFW_UH_WLOCK(chain);
2553         /*
2554          * Hold traffic processing until we finish resize to
2555          * prevent access to states lists.
2556          */
2557         IPFW_WLOCK(chain);
2558         /* Re-link all dynamic states */
2559         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
2560                 DYN_RELINK_STATES(s4, data->hashval, bucket, ipv4, ipv4);
2561                 DYN_RELINK_STATES(s4, limit->hashval, bucket, ipv4_parent,
2562                     ipv4_parent);
2563 #ifdef INET6
2564                 DYN_RELINK_STATES(s6, data->hashval, bucket, ipv6, ipv6);
2565                 DYN_RELINK_STATES(s6, limit->hashval, bucket, ipv6_parent,
2566                     ipv6_parent);
2567 #endif
2568         }
2569
2570 #define DYN_SWAP_PTR(old, new, tmp)     do {            \
2571         tmp = old;                                      \
2572         old = new;                                      \
2573         new = tmp;                                      \
2574 } while (0)
2575         /* Swap pointers */
2576         DYN_SWAP_PTR(V_dyn_bucket_lock, bucket_lock, tmp);
2577         DYN_SWAP_PTR(V_dyn_ipv4, ipv4, tmp);
2578         DYN_SWAP_PTR(V_dyn_ipv4_parent, ipv4_parent, tmp);
2579         DYN_SWAP_PTR(V_dyn_ipv4_add, ipv4_add, tmp);
2580         DYN_SWAP_PTR(V_dyn_ipv4_parent_add, ipv4_parent_add, tmp);
2581         DYN_SWAP_PTR(V_dyn_ipv4_del, ipv4_del, tmp);
2582         DYN_SWAP_PTR(V_dyn_ipv4_parent_del, ipv4_parent_del, tmp);
2583
2584 #ifdef INET6
2585         DYN_SWAP_PTR(V_dyn_ipv6, ipv6, tmp);
2586         DYN_SWAP_PTR(V_dyn_ipv6_parent, ipv6_parent, tmp);
2587         DYN_SWAP_PTR(V_dyn_ipv6_add, ipv6_add, tmp);
2588         DYN_SWAP_PTR(V_dyn_ipv6_parent_add, ipv6_parent_add, tmp);
2589         DYN_SWAP_PTR(V_dyn_ipv6_del, ipv6_del, tmp);
2590         DYN_SWAP_PTR(V_dyn_ipv6_parent_del, ipv6_parent_del, tmp);
2591 #endif
2592         bucket = V_curr_dyn_buckets;
2593         V_curr_dyn_buckets = new;
2594
2595         IPFW_WUNLOCK(chain);
2596         IPFW_UH_WUNLOCK(chain);
2597
2598         /* Release old resources */
2599         while (bucket-- != 0)
2600                 DYN_BUCKET_LOCK_DESTROY(bucket_lock, bucket);
2601         free(bucket_lock, M_IPFW);
2602         free(ipv4, M_IPFW);
2603         free(ipv4_parent, M_IPFW);
2604         free(ipv4_add, M_IPFW);
2605         free(ipv4_parent_add, M_IPFW);
2606         free(ipv4_del, M_IPFW);
2607         free(ipv4_parent_del, M_IPFW);
2608 #ifdef INET6
2609         free(ipv6, M_IPFW);
2610         free(ipv6_parent, M_IPFW);
2611         free(ipv6_add, M_IPFW);
2612         free(ipv6_parent_add, M_IPFW);
2613         free(ipv6_del, M_IPFW);
2614         free(ipv6_parent_del, M_IPFW);
2615 #endif
2616 }
2617
2618 /*
2619  * This function is used to perform various maintenance
2620  * on dynamic hash lists. Currently it is called every second.
2621  */
2622 static void
2623 dyn_tick(void *vnetx)
2624 {
2625         uint32_t buckets;
2626
2627         CURVNET_SET((struct vnet *)vnetx);
2628         /*
2629          * First free states unlinked in previous passes.
2630          */
2631         dyn_free_states(&V_layer3_chain);
2632         /*
2633          * Now unlink others expired states.
2634          * We use IPFW_UH_WLOCK to avoid concurrent call of
2635          * dyn_expire_states(). It is the only function that does
2636          * deletion of state entries from states lists.
2637          */
2638         IPFW_UH_WLOCK(&V_layer3_chain);
2639         dyn_expire_states(&V_layer3_chain, NULL);
2640         IPFW_UH_WUNLOCK(&V_layer3_chain);
2641         /*
2642          * Send keepalives if they are enabled and the time has come.
2643          */
2644         if (V_dyn_keepalive != 0 &&
2645             V_dyn_keepalive_last + V_dyn_keepalive_period <= time_uptime) {
2646                 V_dyn_keepalive_last = time_uptime;
2647                 dyn_send_keepalive_ipv4(&V_layer3_chain);
2648 #ifdef INET6
2649                 dyn_send_keepalive_ipv6(&V_layer3_chain);
2650 #endif
2651         }
2652         /*
2653          * Check if we need to resize the hash:
2654          * if current number of states exceeds number of buckets in hash,
2655          * and dyn_buckets_max permits to grow the number of buckets, then
2656          * do it. Grow hash size to the minimum power of 2 which is bigger
2657          * than current states count.
2658          */
2659         if (V_curr_dyn_buckets < V_dyn_buckets_max &&
2660             (V_curr_dyn_buckets < V_dyn_count / 2 || (
2661             V_curr_dyn_buckets < V_dyn_count && V_curr_max_length > 8))) {
2662                 buckets = 1 << fls(V_dyn_count);
2663                 if (buckets > V_dyn_buckets_max)
2664                         buckets = V_dyn_buckets_max;
2665                 dyn_grow_hashtable(&V_layer3_chain, buckets);
2666         }
2667
2668         callout_reset_on(&V_dyn_timeout, hz, dyn_tick, vnetx, 0);
2669         CURVNET_RESTORE();
2670 }
2671
2672 void
2673 ipfw_expire_dyn_states(struct ip_fw_chain *chain, ipfw_range_tlv *rt)
2674 {
2675         /*
2676          * Do not perform any checks if we currently have no dynamic states
2677          */
2678         if (V_dyn_count == 0)
2679                 return;
2680
2681         IPFW_UH_WLOCK_ASSERT(chain);
2682         dyn_expire_states(chain, rt);
2683 }
2684
2685 /*
2686  * Returns size of dynamic states in legacy format
2687  */
2688 int
2689 ipfw_dyn_len(void)
2690 {
2691
2692         return ((V_dyn_count + V_dyn_parent_count) * sizeof(ipfw_dyn_rule));
2693 }
2694
2695 /*
2696  * Returns number of dynamic states.
2697  * Used by dump format v1 (current).
2698  */
2699 uint32_t
2700 ipfw_dyn_get_count(void)
2701 {
2702
2703         return (V_dyn_count + V_dyn_parent_count);
2704 }
2705
2706 /*
2707  * Check if rule contains at least one dynamic opcode.
2708  *
2709  * Returns 1 if such opcode is found, 0 otherwise.
2710  */
2711 int
2712 ipfw_is_dyn_rule(struct ip_fw *rule)
2713 {
2714         int cmdlen, l;
2715         ipfw_insn *cmd;
2716
2717         l = rule->cmd_len;
2718         cmd = rule->cmd;
2719         cmdlen = 0;
2720         for ( ; l > 0 ; l -= cmdlen, cmd += cmdlen) {
2721                 cmdlen = F_LEN(cmd);
2722
2723                 switch (cmd->opcode) {
2724                 case O_LIMIT:
2725                 case O_KEEP_STATE:
2726                 case O_PROBE_STATE:
2727                 case O_CHECK_STATE:
2728                         return (1);
2729                 }
2730         }
2731
2732         return (0);
2733 }
2734
2735 static void
2736 dyn_export_parent(const struct dyn_parent *p, uint16_t kidx,
2737     ipfw_dyn_rule *dst)
2738 {
2739
2740         dst->dyn_type = O_LIMIT_PARENT;
2741         dst->kidx = kidx;
2742         dst->count = (uint16_t)DPARENT_COUNT(p);
2743         dst->expire = TIME_LEQ(p->expire, time_uptime) ?  0:
2744             p->expire - time_uptime;
2745
2746         /* 'rule' is used to pass up the rule number and set */
2747         memcpy(&dst->rule, &p->rulenum, sizeof(p->rulenum));
2748         /* store set number into high word of dst->rule pointer. */
2749         memcpy((char *)&dst->rule + sizeof(p->rulenum), &p->set,
2750             sizeof(p->set));
2751
2752         /* unused fields */
2753         dst->pcnt = 0;
2754         dst->bcnt = 0;
2755         dst->parent = NULL;
2756         dst->state = 0;
2757         dst->ack_fwd = 0;
2758         dst->ack_rev = 0;
2759         dst->bucket = p->hashval;
2760         /*
2761          * The legacy userland code will interpret a NULL here as a marker
2762          * for the last dynamic rule.
2763          */
2764         dst->next = (ipfw_dyn_rule *)1;
2765 }
2766
2767 static void
2768 dyn_export_data(const struct dyn_data *data, uint16_t kidx, uint8_t type,
2769     ipfw_dyn_rule *dst)
2770 {
2771
2772         dst->dyn_type = type;
2773         dst->kidx = kidx;
2774         dst->pcnt = data->pcnt_fwd + data->pcnt_rev;
2775         dst->bcnt = data->bcnt_fwd + data->bcnt_rev;
2776         dst->expire = TIME_LEQ(data->expire, time_uptime) ?  0:
2777             data->expire - time_uptime;
2778
2779         /* 'rule' is used to pass up the rule number and set */
2780         memcpy(&dst->rule, &data->rulenum, sizeof(data->rulenum));
2781         /* store set number into high word of dst->rule pointer. */
2782         memcpy((char *)&dst->rule + sizeof(data->rulenum), &data->set,
2783             sizeof(data->set));
2784
2785         /* unused fields */
2786         dst->parent = NULL;
2787         dst->state = data->state;
2788         dst->ack_fwd = data->ack_fwd;
2789         dst->ack_rev = data->ack_rev;
2790         dst->count = 0;
2791         dst->bucket = data->hashval;
2792         /*
2793          * The legacy userland code will interpret a NULL here as a marker
2794          * for the last dynamic rule.
2795          */
2796         dst->next = (ipfw_dyn_rule *)1;
2797 }
2798
2799 static void
2800 dyn_export_ipv4_state(const struct dyn_ipv4_state *s, ipfw_dyn_rule *dst)
2801 {
2802
2803         switch (s->type) {
2804         case O_LIMIT_PARENT:
2805                 dyn_export_parent(s->limit, s->kidx, dst);
2806                 break;
2807         default:
2808                 dyn_export_data(s->data, s->kidx, s->type, dst);
2809         }
2810
2811         dst->id.dst_ip = s->dst;
2812         dst->id.src_ip = s->src;
2813         dst->id.dst_port = s->dport;
2814         dst->id.src_port = s->sport;
2815         dst->id.fib = s->data->fibnum;
2816         dst->id.proto = s->proto;
2817         dst->id._flags = 0;
2818         dst->id.addr_type = 4;
2819
2820         memset(&dst->id.dst_ip6, 0, sizeof(dst->id.dst_ip6));
2821         memset(&dst->id.src_ip6, 0, sizeof(dst->id.src_ip6));
2822         dst->id.flow_id6 = dst->id.extra = 0;
2823 }
2824
2825 #ifdef INET6
2826 static void
2827 dyn_export_ipv6_state(const struct dyn_ipv6_state *s, ipfw_dyn_rule *dst)
2828 {
2829
2830         switch (s->type) {
2831         case O_LIMIT_PARENT:
2832                 dyn_export_parent(s->limit, s->kidx, dst);
2833                 break;
2834         default:
2835                 dyn_export_data(s->data, s->kidx, s->type, dst);
2836         }
2837
2838         dst->id.src_ip6 = s->src;
2839         dst->id.dst_ip6 = s->dst;
2840         dst->id.dst_port = s->dport;
2841         dst->id.src_port = s->sport;
2842         dst->id.fib = s->data->fibnum;
2843         dst->id.proto = s->proto;
2844         dst->id._flags = 0;
2845         dst->id.addr_type = 6;
2846
2847         dst->id.dst_ip = dst->id.src_ip = 0;
2848         dst->id.flow_id6 = dst->id.extra = 0;
2849 }
2850 #endif /* INET6 */
2851
2852 /*
2853  * Fills the buffer given by @sd with dynamic states.
2854  * Used by dump format v1 (current).
2855  *
2856  * Returns 0 on success.
2857  */
2858 int
2859 ipfw_dump_states(struct ip_fw_chain *chain, struct sockopt_data *sd)
2860 {
2861 #ifdef INET6
2862         struct dyn_ipv6_state *s6;
2863 #endif
2864         struct dyn_ipv4_state *s4;
2865         ipfw_obj_dyntlv *dst, *last;
2866         ipfw_obj_ctlv *ctlv;
2867         uint32_t bucket;
2868
2869         if (V_dyn_count == 0)
2870                 return (0);
2871
2872         /*
2873          * IPFW_UH_RLOCK garantees that another userland request
2874          * and callout thread will not delete entries from states
2875          * lists.
2876          */
2877         IPFW_UH_RLOCK_ASSERT(chain);
2878
2879         ctlv = (ipfw_obj_ctlv *)ipfw_get_sopt_space(sd, sizeof(*ctlv));
2880         if (ctlv == NULL)
2881                 return (ENOMEM);
2882         ctlv->head.type = IPFW_TLV_DYNSTATE_LIST;
2883         ctlv->objsize = sizeof(ipfw_obj_dyntlv);
2884         last = NULL;
2885
2886 #define DYN_EXPORT_STATES(s, af, h, b)                          \
2887         CK_SLIST_FOREACH(s, &V_dyn_ ## h[b], entry) {                   \
2888                 dst = (ipfw_obj_dyntlv *)ipfw_get_sopt_space(sd,        \
2889                     sizeof(ipfw_obj_dyntlv));                           \
2890                 if (dst == NULL)                                        \
2891                         return (ENOMEM);                                \
2892                 dyn_export_ ## af ## _state(s, &dst->state);            \
2893                 dst->head.length = sizeof(ipfw_obj_dyntlv);             \
2894                 dst->head.type = IPFW_TLV_DYN_ENT;                      \
2895                 last = dst;                                             \
2896         }
2897
2898         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
2899                 DYN_EXPORT_STATES(s4, ipv4, ipv4_parent, bucket);
2900                 DYN_EXPORT_STATES(s4, ipv4, ipv4, bucket);
2901 #ifdef INET6
2902                 DYN_EXPORT_STATES(s6, ipv6, ipv6_parent, bucket);
2903                 DYN_EXPORT_STATES(s6, ipv6, ipv6, bucket);
2904 #endif /* INET6 */
2905         }
2906
2907         /* mark last dynamic rule */
2908         if (last != NULL)
2909                 last->head.flags = IPFW_DF_LAST; /* XXX: unused */
2910         return (0);
2911 #undef DYN_EXPORT_STATES
2912 }
2913
2914 /*
2915  * Fill given buffer with dynamic states (legacy format).
2916  * IPFW_UH_RLOCK has to be held while calling.
2917  */
2918 void
2919 ipfw_get_dynamic(struct ip_fw_chain *chain, char **pbp, const char *ep)
2920 {
2921 #ifdef INET6
2922         struct dyn_ipv6_state *s6;
2923 #endif
2924         struct dyn_ipv4_state *s4;
2925         ipfw_dyn_rule *p, *last = NULL;
2926         char *bp;
2927         uint32_t bucket;
2928
2929         if (V_dyn_count == 0)
2930                 return;
2931         bp = *pbp;
2932
2933         IPFW_UH_RLOCK_ASSERT(chain);
2934
2935 #define DYN_EXPORT_STATES(s, af, head, b)                               \
2936         CK_SLIST_FOREACH(s, &V_dyn_ ## head[b], entry) {                \
2937                 if (bp + sizeof(*p) > ep)                               \
2938                         break;                                          \
2939                 p = (ipfw_dyn_rule *)bp;                                \
2940                 dyn_export_ ## af ## _state(s, p);                      \
2941                 last = p;                                               \
2942                 bp += sizeof(*p);                                       \
2943         }
2944
2945         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
2946                 DYN_EXPORT_STATES(s4, ipv4, ipv4_parent, bucket);
2947                 DYN_EXPORT_STATES(s4, ipv4, ipv4, bucket);
2948 #ifdef INET6
2949                 DYN_EXPORT_STATES(s6, ipv6, ipv6_parent, bucket);
2950                 DYN_EXPORT_STATES(s6, ipv6, ipv6, bucket);
2951 #endif /* INET6 */
2952         }
2953
2954         if (last != NULL) /* mark last dynamic rule */
2955                 last->next = NULL;
2956         *pbp = bp;
2957 #undef DYN_EXPORT_STATES
2958 }
2959
2960 void
2961 ipfw_dyn_init(struct ip_fw_chain *chain)
2962 {
2963
2964 #ifdef IPFIREWALL_JENKINSHASH
2965         V_dyn_hashseed = arc4random();
2966 #endif
2967         V_dyn_max = 16384;              /* max # of states */
2968         V_dyn_parent_max = 4096;        /* max # of parent states */
2969         V_dyn_buckets_max = 8192;       /* must be power of 2 */
2970
2971         V_dyn_ack_lifetime = 300;
2972         V_dyn_syn_lifetime = 20;
2973         V_dyn_fin_lifetime = 1;
2974         V_dyn_rst_lifetime = 1;
2975         V_dyn_udp_lifetime = 10;
2976         V_dyn_short_lifetime = 5;
2977
2978         V_dyn_keepalive_interval = 20;
2979         V_dyn_keepalive_period = 5;
2980         V_dyn_keepalive = 1;            /* send keepalives */
2981         V_dyn_keepalive_last = time_uptime;
2982
2983         V_dyn_data_zone = uma_zcreate("IPFW dynamic states data",
2984             sizeof(struct dyn_data), NULL, NULL, NULL, NULL,
2985             UMA_ALIGN_PTR, 0);
2986         uma_zone_set_max(V_dyn_data_zone, V_dyn_max);
2987
2988         V_dyn_parent_zone = uma_zcreate("IPFW parent dynamic states",
2989             sizeof(struct dyn_parent), NULL, NULL, NULL, NULL,
2990             UMA_ALIGN_PTR, 0);
2991         uma_zone_set_max(V_dyn_parent_zone, V_dyn_parent_max);
2992
2993         SLIST_INIT(&V_dyn_expired_ipv4);
2994         V_dyn_ipv4 = NULL;
2995         V_dyn_ipv4_parent = NULL;
2996         V_dyn_ipv4_zone = uma_zcreate("IPFW IPv4 dynamic states",
2997             sizeof(struct dyn_ipv4_state), NULL, NULL, NULL, NULL,
2998             UMA_ALIGN_PTR, 0);
2999
3000 #ifdef INET6
3001         SLIST_INIT(&V_dyn_expired_ipv6);
3002         V_dyn_ipv6 = NULL;
3003         V_dyn_ipv6_parent = NULL;
3004         V_dyn_ipv6_zone = uma_zcreate("IPFW IPv6 dynamic states",
3005             sizeof(struct dyn_ipv6_state), NULL, NULL, NULL, NULL,
3006             UMA_ALIGN_PTR, 0);
3007 #endif
3008
3009         /* Initialize buckets. */
3010         V_curr_dyn_buckets = 0;
3011         V_dyn_bucket_lock = NULL;
3012         dyn_grow_hashtable(chain, 256);
3013
3014         if (IS_DEFAULT_VNET(curvnet))
3015                 dyn_hp_cache = malloc(mp_ncpus * sizeof(void *), M_IPFW,
3016                     M_WAITOK | M_ZERO);
3017
3018         DYN_EXPIRED_LOCK_INIT();
3019         callout_init(&V_dyn_timeout, 1);
3020         callout_reset(&V_dyn_timeout, hz, dyn_tick, curvnet);
3021         IPFW_ADD_OBJ_REWRITER(IS_DEFAULT_VNET(curvnet), dyn_opcodes);
3022 }
3023
3024 void
3025 ipfw_dyn_uninit(int pass)
3026 {
3027 #ifdef INET6
3028         struct dyn_ipv6_state *s6;
3029 #endif
3030         struct dyn_ipv4_state *s4;
3031         int bucket;
3032
3033         if (pass == 0) {
3034                 callout_drain(&V_dyn_timeout);
3035                 return;
3036         }
3037         IPFW_DEL_OBJ_REWRITER(IS_DEFAULT_VNET(curvnet), dyn_opcodes);
3038         DYN_EXPIRED_LOCK_DESTROY();
3039
3040 #define DYN_FREE_STATES_FORCED(CK, s, af, name, en)     do {            \
3041         while ((s = CK ## SLIST_FIRST(&V_dyn_ ## name)) != NULL) {      \
3042                 CK ## SLIST_REMOVE_HEAD(&V_dyn_ ## name, en);   \
3043                 if (s->type == O_LIMIT_PARENT)                          \
3044                         uma_zfree(V_dyn_parent_zone, s->limit);         \
3045                 else                                                    \
3046                         uma_zfree(V_dyn_data_zone, s->data);            \
3047                 uma_zfree(V_dyn_ ## af ## _zone, s);                    \
3048         }                                                               \
3049 } while (0)
3050         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
3051                 DYN_BUCKET_LOCK_DESTROY(V_dyn_bucket_lock, bucket);
3052
3053                 DYN_FREE_STATES_FORCED(CK_, s4, ipv4, ipv4[bucket], entry);
3054                 DYN_FREE_STATES_FORCED(CK_, s4, ipv4, ipv4_parent[bucket],
3055                     entry);
3056 #ifdef INET6
3057                 DYN_FREE_STATES_FORCED(CK_, s6, ipv6, ipv6[bucket], entry);
3058                 DYN_FREE_STATES_FORCED(CK_, s6, ipv6, ipv6_parent[bucket],
3059                     entry);
3060 #endif /* INET6 */
3061         }
3062         DYN_FREE_STATES_FORCED(, s4, ipv4, expired_ipv4, expired);
3063 #ifdef INET6
3064         DYN_FREE_STATES_FORCED(, s6, ipv6, expired_ipv6, expired);
3065 #endif
3066 #undef DYN_FREE_STATES_FORCED
3067
3068         uma_zdestroy(V_dyn_ipv4_zone);
3069         uma_zdestroy(V_dyn_data_zone);
3070         uma_zdestroy(V_dyn_parent_zone);
3071 #ifdef INET6
3072         uma_zdestroy(V_dyn_ipv6_zone);
3073         free(V_dyn_ipv6, M_IPFW);
3074         free(V_dyn_ipv6_parent, M_IPFW);
3075         free(V_dyn_ipv6_add, M_IPFW);
3076         free(V_dyn_ipv6_parent_add, M_IPFW);
3077         free(V_dyn_ipv6_del, M_IPFW);
3078         free(V_dyn_ipv6_parent_del, M_IPFW);
3079 #endif
3080         free(V_dyn_bucket_lock, M_IPFW);
3081         free(V_dyn_ipv4, M_IPFW);
3082         free(V_dyn_ipv4_parent, M_IPFW);
3083         free(V_dyn_ipv4_add, M_IPFW);
3084         free(V_dyn_ipv4_parent_add, M_IPFW);
3085         free(V_dyn_ipv4_del, M_IPFW);
3086         free(V_dyn_ipv4_parent_del, M_IPFW);
3087         if (IS_DEFAULT_VNET(curvnet))
3088                 free(dyn_hp_cache, M_IPFW);
3089 }
3090
3091