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_keepalive != 0 &&
 983                     V_dyn_rst_lifetime >= V_dyn_keepalive_period)
 984                         V_dyn_rst_lifetime = V_dyn_keepalive_period - 1;
 985                 expire = time_uptime + V_dyn_rst_lifetime;
 986         }
 987         /* Save TCP state if it was changed */
 988         if ((state & TCP_FLAGS) != (old & TCP_FLAGS))
 989                 ck_pr_or_32(&data->state, state & TCP_FLAGS);
 990         return (expire);
 991 }
 992
 993 /*
 994  * Update ULP specific state.
 995  * For TCP we keep sequence numbers and flags. For other protocols
 996  * currently we update only expire time. Packets and bytes counters
 997  * are also updated here.
 998  */
 999 static void
1000 dyn_update_proto_state(struct dyn_data *data, const struct ipfw_flow_id *pkt,
1001     const void *ulp, int pktlen, int dir)
1002 {
1003         uint32_t expire;
1004
1005         /* NOTE: we are in critical section here. */
1006         switch (pkt->proto) {
1007         case IPPROTO_UDP:
1008         case IPPROTO_UDPLITE:
1009                 expire = time_uptime + V_dyn_udp_lifetime;
1010                 break;
1011         case IPPROTO_TCP:
1012                 expire = dyn_update_tcp_state(data, pkt, ulp, dir);
1013                 break;
1014         default:
1015                 expire = time_uptime + V_dyn_short_lifetime;
1016         }
1017         /*
1018          * Expiration timer has the per-second granularity, no need to update
1019          * it every time when state is matched.
1020          */
1021         if (data->expire != expire)
1022                 ck_pr_store_32(&data->expire, expire);
1023
1024         if (dir == MATCH_FORWARD)
1025                 DYN_COUNTER_INC(data, fwd, pktlen);
1026         else
1027                 DYN_COUNTER_INC(data, rev, pktlen);
1028 }
1029
1030 /*
1031  * Lookup IPv4 state.
1032  * Must be called in critical section.
1033  */
1034 struct dyn_ipv4_state *
1035 dyn_lookup_ipv4_state(const struct ipfw_flow_id *pkt, const void *ulp,
1036     struct ipfw_dyn_info *info, int pktlen)
1037 {
1038         struct dyn_ipv4_state *s;
1039         uint32_t version, bucket;
1040
1041         bucket = DYN_BUCKET(info->hashval, V_curr_dyn_buckets);
1042         info->version = DYN_BUCKET_VERSION(bucket, ipv4_add);
1043 restart:
1044         version = DYN_BUCKET_VERSION(bucket, ipv4_del);
1045         CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) {
1046                 DYNSTATE_PROTECT(s);
1047                 if (version != DYN_BUCKET_VERSION(bucket, ipv4_del))
1048                         goto restart;
1049                 if (s->proto != pkt->proto)
1050                         continue;
1051                 if (info->kidx != 0 && s->kidx != info->kidx)
1052                         continue;
1053                 if (s->sport == pkt->src_port && s->dport == pkt->dst_port &&
1054                     s->src == pkt->src_ip && s->dst == pkt->dst_ip) {
1055                         info->direction = MATCH_FORWARD;
1056                         break;
1057                 }
1058                 if (s->sport == pkt->dst_port && s->dport == pkt->src_port &&
1059                     s->src == pkt->dst_ip && s->dst == pkt->src_ip) {
1060                         info->direction = MATCH_REVERSE;
1061                         break;
1062                 }
1063         }
1064
1065         if (s != NULL)
1066                 dyn_update_proto_state(s->data, pkt, ulp, pktlen,
1067                     info->direction);
1068         return (s);
1069 }
1070
1071 /*
1072  * Lookup IPv4 state.
1073  * Simplifed version is used to check that matching state doesn't exist.
1074  */
1075 static int
1076 dyn_lookup_ipv4_state_locked(const struct ipfw_flow_id *pkt,
1077     const void *ulp, int pktlen, uint32_t bucket, uint16_t kidx)
1078 {
1079         struct dyn_ipv4_state *s;
1080         int dir;
1081
1082         dir = MATCH_NONE;
1083         DYN_BUCKET_ASSERT(bucket);
1084         CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) {
1085                 if (s->proto != pkt->proto ||
1086                     s->kidx != kidx)
1087                         continue;
1088                 if (s->sport == pkt->src_port &&
1089                     s->dport == pkt->dst_port &&
1090                     s->src == pkt->src_ip && s->dst == pkt->dst_ip) {
1091                         dir = MATCH_FORWARD;
1092                         break;
1093                 }
1094                 if (s->sport == pkt->dst_port && s->dport == pkt->src_port &&
1095                     s->src == pkt->dst_ip && s->dst == pkt->src_ip) {
1096                         dir = MATCH_REVERSE;
1097                         break;
1098                 }
1099         }
1100         if (s != NULL)
1101                 dyn_update_proto_state(s->data, pkt, ulp, pktlen, dir);
1102         return (s != NULL);
1103 }
1104
1105 struct dyn_ipv4_state *
1106 dyn_lookup_ipv4_parent(const struct ipfw_flow_id *pkt, const void *rule,
1107     uint32_t ruleid, uint16_t rulenum, uint32_t hashval)
1108 {
1109         struct dyn_ipv4_state *s;
1110         uint32_t version, bucket;
1111
1112         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1113 restart:
1114         version = DYN_BUCKET_VERSION(bucket, ipv4_parent_del);
1115         CK_SLIST_FOREACH(s, &V_dyn_ipv4_parent[bucket], entry) {
1116                 DYNSTATE_PROTECT(s);
1117                 if (version != DYN_BUCKET_VERSION(bucket, ipv4_parent_del))
1118                         goto restart;
1119                 /*
1120                  * NOTE: we do not need to check kidx, because parent rule
1121                  * can not create states with different kidx.
1122                  * And parent rule always created for forward direction.
1123                  */
1124                 if (s->limit->parent == rule &&
1125                     s->limit->ruleid == ruleid &&
1126                     s->limit->rulenum == rulenum &&
1127                     s->proto == pkt->proto &&
1128                     s->sport == pkt->src_port &&
1129                     s->dport == pkt->dst_port &&
1130                     s->src == pkt->src_ip && s->dst == pkt->dst_ip) {
1131                         if (s->limit->expire != time_uptime +
1132                             V_dyn_short_lifetime)
1133                                 ck_pr_store_32(&s->limit->expire,
1134                                     time_uptime + V_dyn_short_lifetime);
1135                         break;
1136                 }
1137         }
1138         return (s);
1139 }
1140
1141 static struct dyn_ipv4_state *
1142 dyn_lookup_ipv4_parent_locked(const struct ipfw_flow_id *pkt,
1143     const void *rule, uint32_t ruleid, uint16_t rulenum, uint32_t bucket)
1144 {
1145         struct dyn_ipv4_state *s;
1146
1147         DYN_BUCKET_ASSERT(bucket);
1148         CK_SLIST_FOREACH(s, &V_dyn_ipv4_parent[bucket], entry) {
1149                 if (s->limit->parent == rule &&
1150                     s->limit->ruleid == ruleid &&
1151                     s->limit->rulenum == rulenum &&
1152                     s->proto == pkt->proto &&
1153                     s->sport == pkt->src_port &&
1154                     s->dport == pkt->dst_port &&
1155                     s->src == pkt->src_ip && s->dst == pkt->dst_ip)
1156                         break;
1157         }
1158         return (s);
1159 }
1160
1161
1162 #ifdef INET6
1163 static uint32_t
1164 dyn_getscopeid(const struct ip_fw_args *args)
1165 {
1166
1167         /*
1168          * If source or destination address is an scopeid address, we need
1169          * determine the scope zone id to resolve address scope ambiguity.
1170          */
1171         if (IN6_IS_ADDR_LINKLOCAL(&args->f_id.src_ip6) ||
1172             IN6_IS_ADDR_LINKLOCAL(&args->f_id.dst_ip6)) {
1173                 MPASS(args->oif != NULL ||
1174                     args->m->m_pkthdr.rcvif != NULL);
1175                 return (in6_getscopezone(args->oif != NULL ? args->oif:
1176                     args->m->m_pkthdr.rcvif, IPV6_ADDR_SCOPE_LINKLOCAL));
1177         }
1178         return (0);
1179 }
1180
1181 /*
1182  * Lookup IPv6 state.
1183  * Must be called in critical section.
1184  */
1185 static struct dyn_ipv6_state *
1186 dyn_lookup_ipv6_state(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1187     const void *ulp, struct ipfw_dyn_info *info, int pktlen)
1188 {
1189         struct dyn_ipv6_state *s;
1190         uint32_t version, bucket;
1191
1192         bucket = DYN_BUCKET(info->hashval, V_curr_dyn_buckets);
1193         info->version = DYN_BUCKET_VERSION(bucket, ipv6_add);
1194 restart:
1195         version = DYN_BUCKET_VERSION(bucket, ipv6_del);
1196         CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) {
1197                 DYNSTATE_PROTECT(s);
1198                 if (version != DYN_BUCKET_VERSION(bucket, ipv6_del))
1199                         goto restart;
1200                 if (s->proto != pkt->proto || s->zoneid != zoneid)
1201                         continue;
1202                 if (info->kidx != 0 && s->kidx != info->kidx)
1203                         continue;
1204                 if (s->sport == pkt->src_port && s->dport == pkt->dst_port &&
1205                     IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) &&
1206                     IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) {
1207                         info->direction = MATCH_FORWARD;
1208                         break;
1209                 }
1210                 if (s->sport == pkt->dst_port && s->dport == pkt->src_port &&
1211                     IN6_ARE_ADDR_EQUAL(&s->src, &pkt->dst_ip6) &&
1212                     IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->src_ip6)) {
1213                         info->direction = MATCH_REVERSE;
1214                         break;
1215                 }
1216         }
1217         if (s != NULL)
1218                 dyn_update_proto_state(s->data, pkt, ulp, pktlen,
1219                     info->direction);
1220         return (s);
1221 }
1222
1223 /*
1224  * Lookup IPv6 state.
1225  * Simplifed version is used to check that matching state doesn't exist.
1226  */
1227 static int
1228 dyn_lookup_ipv6_state_locked(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1229     const void *ulp, int pktlen, uint32_t bucket, uint16_t kidx)
1230 {
1231         struct dyn_ipv6_state *s;
1232         int dir;
1233
1234         dir = MATCH_NONE;
1235         DYN_BUCKET_ASSERT(bucket);
1236         CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) {
1237                 if (s->proto != pkt->proto || s->kidx != kidx ||
1238                     s->zoneid != zoneid)
1239                         continue;
1240                 if (s->sport == pkt->src_port && s->dport == pkt->dst_port &&
1241                     IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) &&
1242                     IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) {
1243                         dir = MATCH_FORWARD;
1244                         break;
1245                 }
1246                 if (s->sport == pkt->dst_port && s->dport == pkt->src_port &&
1247                     IN6_ARE_ADDR_EQUAL(&s->src, &pkt->dst_ip6) &&
1248                     IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->src_ip6)) {
1249                         dir = MATCH_REVERSE;
1250                         break;
1251                 }
1252         }
1253         if (s != NULL)
1254                 dyn_update_proto_state(s->data, pkt, ulp, pktlen, dir);
1255         return (s != NULL);
1256 }
1257
1258 static struct dyn_ipv6_state *
1259 dyn_lookup_ipv6_parent(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1260     const void *rule, uint32_t ruleid, uint16_t rulenum, uint32_t hashval)
1261 {
1262         struct dyn_ipv6_state *s;
1263         uint32_t version, bucket;
1264
1265         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1266 restart:
1267         version = DYN_BUCKET_VERSION(bucket, ipv6_parent_del);
1268         CK_SLIST_FOREACH(s, &V_dyn_ipv6_parent[bucket], entry) {
1269                 DYNSTATE_PROTECT(s);
1270                 if (version != DYN_BUCKET_VERSION(bucket, ipv6_parent_del))
1271                         goto restart;
1272                 /*
1273                  * NOTE: we do not need to check kidx, because parent rule
1274                  * can not create states with different kidx.
1275                  * Also parent rule always created for forward direction.
1276                  */
1277                 if (s->limit->parent == rule &&
1278                     s->limit->ruleid == ruleid &&
1279                     s->limit->rulenum == rulenum &&
1280                     s->proto == pkt->proto &&
1281                     s->sport == pkt->src_port &&
1282                     s->dport == pkt->dst_port && s->zoneid == zoneid &&
1283                     IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) &&
1284                     IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) {
1285                         if (s->limit->expire != time_uptime +
1286                             V_dyn_short_lifetime)
1287                                 ck_pr_store_32(&s->limit->expire,
1288                                     time_uptime + V_dyn_short_lifetime);
1289                         break;
1290                 }
1291         }
1292         return (s);
1293 }
1294
1295 static struct dyn_ipv6_state *
1296 dyn_lookup_ipv6_parent_locked(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1297     const void *rule, uint32_t ruleid, uint16_t rulenum, uint32_t bucket)
1298 {
1299         struct dyn_ipv6_state *s;
1300
1301         DYN_BUCKET_ASSERT(bucket);
1302         CK_SLIST_FOREACH(s, &V_dyn_ipv6_parent[bucket], entry) {
1303                 if (s->limit->parent == rule &&
1304                     s->limit->ruleid == ruleid &&
1305                     s->limit->rulenum == rulenum &&
1306                     s->proto == pkt->proto &&
1307                     s->sport == pkt->src_port &&
1308                     s->dport == pkt->dst_port && s->zoneid == zoneid &&
1309                     IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) &&
1310                     IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6))
1311                         break;
1312         }
1313         return (s);
1314 }
1315
1316 #endif /* INET6 */
1317
1318 /*
1319  * Lookup dynamic state.
1320  *  pkt - filled by ipfw_chk() ipfw_flow_id;
1321  *  ulp - determined by ipfw_chk() upper level protocol header;
1322  *  dyn_info - info about matched state to return back;
1323  * Returns pointer to state's parent rule and dyn_info. If there is
1324  * no state, NULL is returned.
1325  * On match ipfw_dyn_lookup() updates state's counters.
1326  */
1327 struct ip_fw *
1328 ipfw_dyn_lookup_state(const struct ip_fw_args *args, const void *ulp,
1329     int pktlen, const ipfw_insn *cmd, struct ipfw_dyn_info *info)
1330 {
1331         struct dyn_data *data;
1332         struct ip_fw *rule;
1333
1334         IPFW_RLOCK_ASSERT(&V_layer3_chain);
1335
1336         data = NULL;
1337         rule = NULL;
1338         info->kidx = cmd->arg1;
1339         info->direction = MATCH_NONE;
1340         info->hashval = hash_packet(&args->f_id);
1341
1342         DYNSTATE_CRITICAL_ENTER();
1343         if (IS_IP4_FLOW_ID(&args->f_id)) {
1344                 struct dyn_ipv4_state *s;
1345
1346                 s = dyn_lookup_ipv4_state(&args->f_id, ulp, info, pktlen);
1347                 if (s != NULL) {
1348                         /*
1349                          * Dynamic states are created using the same 5-tuple,
1350                          * so it is assumed, that parent rule for O_LIMIT
1351                          * state has the same address family.
1352                          */
1353                         data = s->data;
1354                         if (s->type == O_LIMIT) {
1355                                 s = data->parent;
1356                                 rule = s->limit->parent;
1357                         } else
1358                                 rule = data->parent;
1359                 }
1360         }
1361 #ifdef INET6
1362         else if (IS_IP6_FLOW_ID(&args->f_id)) {
1363                 struct dyn_ipv6_state *s;
1364
1365                 s = dyn_lookup_ipv6_state(&args->f_id, dyn_getscopeid(args),
1366                     ulp, info, pktlen);
1367                 if (s != NULL) {
1368                         data = s->data;
1369                         if (s->type == O_LIMIT) {
1370                                 s = data->parent;
1371                                 rule = s->limit->parent;
1372                         } else
1373                                 rule = data->parent;
1374                 }
1375         }
1376 #endif
1377         if (data != NULL) {
1378                 /*
1379                  * If cached chain id is the same, we can avoid rule index
1380                  * lookup. Otherwise do lookup and update chain_id and f_pos.
1381                  * It is safe even if there is concurrent thread that want
1382                  * update the same state, because chain->id can be changed
1383                  * only under IPFW_WLOCK().
1384                  */
1385                 if (data->chain_id != V_layer3_chain.id) {
1386                         data->f_pos = ipfw_find_rule(&V_layer3_chain,
1387                             data->rulenum, data->ruleid);
1388                         /*
1389                          * Check that found state has not orphaned.
1390                          * When chain->id being changed the parent
1391                          * rule can be deleted. If found rule doesn't
1392                          * match the parent pointer, consider this
1393                          * result as MATCH_NONE and return NULL.
1394                          *
1395                          * This will lead to creation of new similar state
1396                          * that will be added into head of this bucket.
1397                          * And the state that we currently have matched
1398                          * should be deleted by dyn_expire_states().
1399                          *
1400                          * In case when dyn_keep_states is enabled, return
1401                          * pointer to default rule and corresponding f_pos
1402                          * value.
1403                          * XXX: In this case we lose the cache efficiency,
1404                          *      since f_pos is not cached, because it seems
1405                          *      there is no easy way to atomically switch
1406                          *      all fields related to parent rule of given
1407                          *      state.
1408                          */
1409                         if (V_layer3_chain.map[data->f_pos] == rule) {
1410                                 data->chain_id = V_layer3_chain.id;
1411                                 info->f_pos = data->f_pos;
1412                         } else if (V_dyn_keep_states != 0) {
1413                                 rule = V_layer3_chain.default_rule;
1414                                 info->f_pos = V_layer3_chain.n_rules - 1;
1415                         } else {
1416                                 rule = NULL;
1417                                 info->direction = MATCH_NONE;
1418                                 DYN_DEBUG("rule %p  [%u, %u] is considered "
1419                                     "invalid in data %p", rule, data->ruleid,
1420                                     data->rulenum, data);
1421                                 /* info->f_pos doesn't matter here. */
1422                         }
1423                 } else
1424                         info->f_pos = data->f_pos;
1425         }
1426         DYNSTATE_CRITICAL_EXIT();
1427 #if 0
1428         /*
1429          * Return MATCH_NONE if parent rule is in disabled set.
1430          * This will lead to creation of new similar state that
1431          * will be added into head of this bucket.
1432          *
1433          * XXXAE: we need to be able update state's set when parent
1434          *        rule set is changed.
1435          */
1436         if (rule != NULL && (V_set_disable & (1 << rule->set))) {
1437                 rule = NULL;
1438                 info->direction = MATCH_NONE;
1439         }
1440 #endif
1441         return (rule);
1442 }
1443
1444 static struct dyn_parent *
1445 dyn_alloc_parent(void *parent, uint32_t ruleid, uint16_t rulenum,
1446     uint8_t set, uint32_t hashval)
1447 {
1448         struct dyn_parent *limit;
1449
1450         limit = uma_zalloc(V_dyn_parent_zone, M_NOWAIT | M_ZERO);
1451         if (limit == NULL) {
1452                 if (last_log != time_uptime) {
1453                         last_log = time_uptime;
1454                         log(LOG_DEBUG,
1455                             "ipfw: Cannot allocate parent dynamic state, "
1456                             "consider increasing "
1457                             "net.inet.ip.fw.dyn_parent_max\n");
1458                 }
1459                 return (NULL);
1460         }
1461
1462         limit->parent = parent;
1463         limit->ruleid = ruleid;
1464         limit->rulenum = rulenum;
1465         limit->set = set;
1466         limit->hashval = hashval;
1467         limit->expire = time_uptime + V_dyn_short_lifetime;
1468         return (limit);
1469 }
1470
1471 static struct dyn_data *
1472 dyn_alloc_dyndata(void *parent, uint32_t ruleid, uint16_t rulenum,
1473     uint8_t set, const struct ipfw_flow_id *pkt, const void *ulp, int pktlen,
1474     uint32_t hashval, uint16_t fibnum)
1475 {
1476         struct dyn_data *data;
1477
1478         data = uma_zalloc(V_dyn_data_zone, M_NOWAIT | M_ZERO);
1479         if (data == NULL) {
1480                 if (last_log != time_uptime) {
1481                         last_log = time_uptime;
1482                         log(LOG_DEBUG,
1483                             "ipfw: Cannot allocate dynamic state, "
1484                             "consider increasing net.inet.ip.fw.dyn_max\n");
1485                 }
1486                 return (NULL);
1487         }
1488
1489         data->parent = parent;
1490         data->ruleid = ruleid;
1491         data->rulenum = rulenum;
1492         data->set = set;
1493         data->fibnum = fibnum;
1494         data->hashval = hashval;
1495         data->expire = time_uptime + V_dyn_syn_lifetime;
1496         dyn_update_proto_state(data, pkt, ulp, pktlen, MATCH_FORWARD);
1497         return (data);
1498 }
1499
1500 static struct dyn_ipv4_state *
1501 dyn_alloc_ipv4_state(const struct ipfw_flow_id *pkt, uint16_t kidx,
1502     uint8_t type)
1503 {
1504         struct dyn_ipv4_state *s;
1505
1506         s = uma_zalloc(V_dyn_ipv4_zone, M_NOWAIT | M_ZERO);
1507         if (s == NULL)
1508                 return (NULL);
1509
1510         s->type = type;
1511         s->kidx = kidx;
1512         s->proto = pkt->proto;
1513         s->sport = pkt->src_port;
1514         s->dport = pkt->dst_port;
1515         s->src = pkt->src_ip;
1516         s->dst = pkt->dst_ip;
1517         return (s);
1518 }
1519
1520 /*
1521  * Add IPv4 parent state.
1522  * Returns pointer to parent state. When it is not NULL we are in
1523  * critical section and pointer protected by hazard pointer.
1524  * When some error occurs, it returns NULL and exit from critical section
1525  * is not needed.
1526  */
1527 static struct dyn_ipv4_state *
1528 dyn_add_ipv4_parent(void *rule, uint32_t ruleid, uint16_t rulenum,
1529     uint8_t set, const struct ipfw_flow_id *pkt, uint32_t hashval,
1530     uint32_t version, uint16_t kidx)
1531 {
1532         struct dyn_ipv4_state *s;
1533         struct dyn_parent *limit;
1534         uint32_t bucket;
1535
1536         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1537         DYN_BUCKET_LOCK(bucket);
1538         if (version != DYN_BUCKET_VERSION(bucket, ipv4_parent_add)) {
1539                 /*
1540                  * Bucket version has been changed since last lookup,
1541                  * do lookup again to be sure that state does not exist.
1542                  */
1543                 s = dyn_lookup_ipv4_parent_locked(pkt, rule, ruleid,
1544                     rulenum, bucket);
1545                 if (s != NULL) {
1546                         /*
1547                          * Simultaneous thread has already created this
1548                          * state. Just return it.
1549                          */
1550                         DYNSTATE_CRITICAL_ENTER();
1551                         DYNSTATE_PROTECT(s);
1552                         DYN_BUCKET_UNLOCK(bucket);
1553                         return (s);
1554                 }
1555         }
1556
1557         limit = dyn_alloc_parent(rule, ruleid, rulenum, set, hashval);
1558         if (limit == NULL) {
1559                 DYN_BUCKET_UNLOCK(bucket);
1560                 return (NULL);
1561         }
1562
1563         s = dyn_alloc_ipv4_state(pkt, kidx, O_LIMIT_PARENT);
1564         if (s == NULL) {
1565                 DYN_BUCKET_UNLOCK(bucket);
1566                 uma_zfree(V_dyn_parent_zone, limit);
1567                 return (NULL);
1568         }
1569
1570         s->limit = limit;
1571         CK_SLIST_INSERT_HEAD(&V_dyn_ipv4_parent[bucket], s, entry);
1572         DYN_COUNT_INC(dyn_parent_count);
1573         DYN_BUCKET_VERSION_BUMP(bucket, ipv4_parent_add);
1574         DYNSTATE_CRITICAL_ENTER();
1575         DYNSTATE_PROTECT(s);
1576         DYN_BUCKET_UNLOCK(bucket);
1577         return (s);
1578 }
1579
1580 static int
1581 dyn_add_ipv4_state(void *parent, uint32_t ruleid, uint16_t rulenum,
1582     uint8_t set, const struct ipfw_flow_id *pkt, const void *ulp, int pktlen,
1583     uint32_t hashval, struct ipfw_dyn_info *info, uint16_t fibnum,
1584     uint16_t kidx, uint8_t type)
1585 {
1586         struct dyn_ipv4_state *s;
1587         void *data;
1588         uint32_t bucket;
1589
1590         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1591         DYN_BUCKET_LOCK(bucket);
1592         if (info->direction == MATCH_UNKNOWN ||
1593             info->kidx != kidx ||
1594             info->hashval != hashval ||
1595             info->version != DYN_BUCKET_VERSION(bucket, ipv4_add)) {
1596                 /*
1597                  * Bucket version has been changed since last lookup,
1598                  * do lookup again to be sure that state does not exist.
1599                  */
1600                 if (dyn_lookup_ipv4_state_locked(pkt, ulp, pktlen,
1601                     bucket, kidx) != 0) {
1602                         DYN_BUCKET_UNLOCK(bucket);
1603                         return (EEXIST);
1604                 }
1605         }
1606
1607         data = dyn_alloc_dyndata(parent, ruleid, rulenum, set, pkt, ulp,
1608             pktlen, hashval, fibnum);
1609         if (data == NULL) {
1610                 DYN_BUCKET_UNLOCK(bucket);
1611                 return (ENOMEM);
1612         }
1613
1614         s = dyn_alloc_ipv4_state(pkt, kidx, type);
1615         if (s == NULL) {
1616                 DYN_BUCKET_UNLOCK(bucket);
1617                 uma_zfree(V_dyn_data_zone, data);
1618                 return (ENOMEM);
1619         }
1620
1621         s->data = data;
1622         CK_SLIST_INSERT_HEAD(&V_dyn_ipv4[bucket], s, entry);
1623         DYN_COUNT_INC(dyn_count);
1624         DYN_BUCKET_VERSION_BUMP(bucket, ipv4_add);
1625         DYN_BUCKET_UNLOCK(bucket);
1626         return (0);
1627 }
1628
1629 #ifdef INET6
1630 static struct dyn_ipv6_state *
1631 dyn_alloc_ipv6_state(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1632     uint16_t kidx, uint8_t type)
1633 {
1634         struct dyn_ipv6_state *s;
1635
1636         s = uma_zalloc(V_dyn_ipv6_zone, M_NOWAIT | M_ZERO);
1637         if (s == NULL)
1638                 return (NULL);
1639
1640         s->type = type;
1641         s->kidx = kidx;
1642         s->zoneid = zoneid;
1643         s->proto = pkt->proto;
1644         s->sport = pkt->src_port;
1645         s->dport = pkt->dst_port;
1646         s->src = pkt->src_ip6;
1647         s->dst = pkt->dst_ip6;
1648         return (s);
1649 }
1650
1651 /*
1652  * Add IPv6 parent state.
1653  * Returns pointer to parent state. When it is not NULL we are in
1654  * critical section and pointer protected by hazard pointer.
1655  * When some error occurs, it return NULL and exit from critical section
1656  * is not needed.
1657  */
1658 static struct dyn_ipv6_state *
1659 dyn_add_ipv6_parent(void *rule, uint32_t ruleid, uint16_t rulenum,
1660     uint8_t set, const struct ipfw_flow_id *pkt, uint32_t zoneid,
1661     uint32_t hashval, uint32_t version, uint16_t kidx)
1662 {
1663         struct dyn_ipv6_state *s;
1664         struct dyn_parent *limit;
1665         uint32_t bucket;
1666
1667         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1668         DYN_BUCKET_LOCK(bucket);
1669         if (version != DYN_BUCKET_VERSION(bucket, ipv6_parent_add)) {
1670                 /*
1671                  * Bucket version has been changed since last lookup,
1672                  * do lookup again to be sure that state does not exist.
1673                  */
1674                 s = dyn_lookup_ipv6_parent_locked(pkt, zoneid, rule, ruleid,
1675                     rulenum, bucket);
1676                 if (s != NULL) {
1677                         /*
1678                          * Simultaneous thread has already created this
1679                          * state. Just return it.
1680                          */
1681                         DYNSTATE_CRITICAL_ENTER();
1682                         DYNSTATE_PROTECT(s);
1683                         DYN_BUCKET_UNLOCK(bucket);
1684                         return (s);
1685                 }
1686         }
1687
1688         limit = dyn_alloc_parent(rule, ruleid, rulenum, set, hashval);
1689         if (limit == NULL) {
1690                 DYN_BUCKET_UNLOCK(bucket);
1691                 return (NULL);
1692         }
1693
1694         s = dyn_alloc_ipv6_state(pkt, zoneid, kidx, O_LIMIT_PARENT);
1695         if (s == NULL) {
1696                 DYN_BUCKET_UNLOCK(bucket);
1697                 uma_zfree(V_dyn_parent_zone, limit);
1698                 return (NULL);
1699         }
1700
1701         s->limit = limit;
1702         CK_SLIST_INSERT_HEAD(&V_dyn_ipv6_parent[bucket], s, entry);
1703         DYN_COUNT_INC(dyn_parent_count);
1704         DYN_BUCKET_VERSION_BUMP(bucket, ipv6_parent_add);
1705         DYNSTATE_CRITICAL_ENTER();
1706         DYNSTATE_PROTECT(s);
1707         DYN_BUCKET_UNLOCK(bucket);
1708         return (s);
1709 }
1710
1711 static int
1712 dyn_add_ipv6_state(void *parent, uint32_t ruleid, uint16_t rulenum,
1713     uint8_t set, const struct ipfw_flow_id *pkt, uint32_t zoneid,
1714     const void *ulp, int pktlen, uint32_t hashval, struct ipfw_dyn_info *info,
1715     uint16_t fibnum, uint16_t kidx, uint8_t type)
1716 {
1717         struct dyn_ipv6_state *s;
1718         struct dyn_data *data;
1719         uint32_t bucket;
1720
1721         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1722         DYN_BUCKET_LOCK(bucket);
1723         if (info->direction == MATCH_UNKNOWN ||
1724             info->kidx != kidx ||
1725             info->hashval != hashval ||
1726             info->version != DYN_BUCKET_VERSION(bucket, ipv6_add)) {
1727                 /*
1728                  * Bucket version has been changed since last lookup,
1729                  * do lookup again to be sure that state does not exist.
1730                  */
1731                 if (dyn_lookup_ipv6_state_locked(pkt, zoneid, ulp, pktlen,
1732                     bucket, kidx) != 0) {
1733                         DYN_BUCKET_UNLOCK(bucket);
1734                         return (EEXIST);
1735                 }
1736         }
1737
1738         data = dyn_alloc_dyndata(parent, ruleid, rulenum, set, pkt, ulp,
1739             pktlen, hashval, fibnum);
1740         if (data == NULL) {
1741                 DYN_BUCKET_UNLOCK(bucket);
1742                 return (ENOMEM);
1743         }
1744
1745         s = dyn_alloc_ipv6_state(pkt, zoneid, kidx, type);
1746         if (s == NULL) {
1747                 DYN_BUCKET_UNLOCK(bucket);
1748                 uma_zfree(V_dyn_data_zone, data);
1749                 return (ENOMEM);
1750         }
1751
1752         s->data = data;
1753         CK_SLIST_INSERT_HEAD(&V_dyn_ipv6[bucket], s, entry);
1754         DYN_COUNT_INC(dyn_count);
1755         DYN_BUCKET_VERSION_BUMP(bucket, ipv6_add);
1756         DYN_BUCKET_UNLOCK(bucket);
1757         return (0);
1758 }
1759 #endif /* INET6 */
1760
1761 static void *
1762 dyn_get_parent_state(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1763     struct ip_fw *rule, uint32_t hashval, uint32_t limit, uint16_t kidx)
1764 {
1765         char sbuf[24];
1766         struct dyn_parent *p;
1767         void *ret;
1768         uint32_t bucket, version;
1769
1770         p = NULL;
1771         ret = NULL;
1772         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
1773         DYNSTATE_CRITICAL_ENTER();
1774         if (IS_IP4_FLOW_ID(pkt)) {
1775                 struct dyn_ipv4_state *s;
1776
1777                 version = DYN_BUCKET_VERSION(bucket, ipv4_parent_add);
1778                 s = dyn_lookup_ipv4_parent(pkt, rule, rule->id,
1779                     rule->rulenum, bucket);
1780                 if (s == NULL) {
1781                         /*
1782                          * Exit from critical section because dyn_add_parent()
1783                          * will acquire bucket lock.
1784                          */
1785                         DYNSTATE_CRITICAL_EXIT();
1786
1787                         s = dyn_add_ipv4_parent(rule, rule->id,
1788                             rule->rulenum, rule->set, pkt, hashval,
1789                             version, kidx);
1790                         if (s == NULL)
1791                                 return (NULL);
1792                         /* Now we are in critical section again. */
1793                 }
1794                 ret = s;
1795                 p = s->limit;
1796         }
1797 #ifdef INET6
1798         else if (IS_IP6_FLOW_ID(pkt)) {
1799                 struct dyn_ipv6_state *s;
1800
1801                 version = DYN_BUCKET_VERSION(bucket, ipv6_parent_add);
1802                 s = dyn_lookup_ipv6_parent(pkt, zoneid, rule, rule->id,
1803                     rule->rulenum, bucket);
1804                 if (s == NULL) {
1805                         /*
1806                          * Exit from critical section because dyn_add_parent()
1807                          * can acquire bucket mutex.
1808                          */
1809                         DYNSTATE_CRITICAL_EXIT();
1810
1811                         s = dyn_add_ipv6_parent(rule, rule->id,
1812                             rule->rulenum, rule->set, pkt, zoneid, hashval,
1813                             version, kidx);
1814                         if (s == NULL)
1815                                 return (NULL);
1816                         /* Now we are in critical section again. */
1817                 }
1818                 ret = s;
1819                 p = s->limit;
1820         }
1821 #endif
1822         else {
1823                 DYNSTATE_CRITICAL_EXIT();
1824                 return (NULL);
1825         }
1826
1827         /* Check the limit */
1828         if (DPARENT_COUNT(p) >= limit) {
1829                 DYNSTATE_CRITICAL_EXIT();
1830                 if (V_fw_verbose && last_log != time_uptime) {
1831                         last_log = time_uptime;
1832                         snprintf(sbuf, sizeof(sbuf), "%u drop session",
1833                             rule->rulenum);
1834                         print_dyn_rule_flags(pkt, O_LIMIT,
1835                             LOG_SECURITY | LOG_DEBUG, sbuf,
1836                             "too many entries");
1837                 }
1838                 return (NULL);
1839         }
1840
1841         /* Take new session into account. */
1842         DPARENT_COUNT_INC(p);
1843         /*
1844          * We must exit from critical section because the following code
1845          * can acquire bucket mutex.
1846          * We rely on the the 'count' field. The state will not expire
1847          * until it has some child states, i.e. 'count' field is not zero.
1848          * Return state pointer, it will be used by child states as parent.
1849          */
1850         DYNSTATE_CRITICAL_EXIT();
1851         return (ret);
1852 }
1853
1854 static int
1855 dyn_install_state(const struct ipfw_flow_id *pkt, uint32_t zoneid,
1856     uint16_t fibnum, const void *ulp, int pktlen, void *rule,
1857     uint32_t ruleid, uint16_t rulenum, uint8_t set,
1858     struct ipfw_dyn_info *info, uint32_t limit, uint16_t limit_mask,
1859     uint16_t kidx, uint8_t type)
1860 {
1861         struct ipfw_flow_id id;
1862         uint32_t hashval, parent_hashval;
1863         int ret;
1864
1865         MPASS(type == O_LIMIT || type == O_KEEP_STATE);
1866
1867         if (type == O_LIMIT) {
1868                 /* Create masked flow id and calculate bucket */
1869                 id.addr_type = pkt->addr_type;
1870                 id.proto = pkt->proto;
1871                 id.fib = fibnum; /* unused */
1872                 id.src_port = (limit_mask & DYN_SRC_PORT) ?
1873                     pkt->src_port: 0;
1874                 id.dst_port = (limit_mask & DYN_DST_PORT) ?
1875                     pkt->dst_port: 0;
1876                 if (IS_IP4_FLOW_ID(pkt)) {
1877                         id.src_ip = (limit_mask & DYN_SRC_ADDR) ?
1878                             pkt->src_ip: 0;
1879                         id.dst_ip = (limit_mask & DYN_DST_ADDR) ?
1880                             pkt->dst_ip: 0;
1881                 }
1882 #ifdef INET6
1883                 else if (IS_IP6_FLOW_ID(pkt)) {
1884                         if (limit_mask & DYN_SRC_ADDR)
1885                                 id.src_ip6 = pkt->src_ip6;
1886                         else
1887                                 memset(&id.src_ip6, 0, sizeof(id.src_ip6));
1888                         if (limit_mask & DYN_DST_ADDR)
1889                                 id.dst_ip6 = pkt->dst_ip6;
1890                         else
1891                                 memset(&id.dst_ip6, 0, sizeof(id.dst_ip6));
1892                 }
1893 #endif
1894                 else
1895                         return (EAFNOSUPPORT);
1896
1897                 parent_hashval = hash_parent(&id, rule);
1898                 rule = dyn_get_parent_state(&id, zoneid, rule, parent_hashval,
1899                     limit, kidx);
1900                 if (rule == NULL) {
1901 #if 0
1902                         if (V_fw_verbose && last_log != time_uptime) {
1903                                 last_log = time_uptime;
1904                                 snprintf(sbuf, sizeof(sbuf),
1905                                     "%u drop session", rule->rulenum);
1906                         print_dyn_rule_flags(pkt, O_LIMIT,
1907                             LOG_SECURITY | LOG_DEBUG, sbuf,
1908                             "too many entries");
1909                         }
1910 #endif
1911                         return (EACCES);
1912                 }
1913                 /*
1914                  * Limit is not reached, create new state.
1915                  * Now rule points to parent state.
1916                  */
1917         }
1918
1919         hashval = hash_packet(pkt);
1920         if (IS_IP4_FLOW_ID(pkt))
1921                 ret = dyn_add_ipv4_state(rule, ruleid, rulenum, set, pkt,
1922                     ulp, pktlen, hashval, info, fibnum, kidx, type);
1923 #ifdef INET6
1924         else if (IS_IP6_FLOW_ID(pkt))
1925                 ret = dyn_add_ipv6_state(rule, ruleid, rulenum, set, pkt,
1926                     zoneid, ulp, pktlen, hashval, info, fibnum, kidx, type);
1927 #endif /* INET6 */
1928         else
1929                 ret = EAFNOSUPPORT;
1930
1931         if (type == O_LIMIT) {
1932                 if (ret != 0) {
1933                         /*
1934                          * We failed to create child state for O_LIMIT
1935                          * opcode. Since we already counted it in the parent,
1936                          * we must revert counter back. The 'rule' points to
1937                          * parent state, use it to get dyn_parent.
1938                          *
1939                          * XXXAE: it should be safe to use 'rule' pointer
1940                          * without extra lookup, parent state is referenced
1941                          * and should not be freed.
1942                          */
1943                         if (IS_IP4_FLOW_ID(&id))
1944                                 DPARENT_COUNT_DEC(
1945                                     ((struct dyn_ipv4_state *)rule)->limit);
1946 #ifdef INET6
1947                         else if (IS_IP6_FLOW_ID(&id))
1948                                 DPARENT_COUNT_DEC(
1949                                     ((struct dyn_ipv6_state *)rule)->limit);
1950 #endif
1951                 }
1952         }
1953         /*
1954          * EEXIST means that simultaneous thread has created this
1955          * state. Consider this as success.
1956          *
1957          * XXXAE: should we invalidate 'info' content here?
1958          */
1959         if (ret == EEXIST)
1960                 return (0);
1961         return (ret);
1962 }
1963
1964 /*
1965  * Install dynamic state.
1966  *  chain - ipfw's instance;
1967  *  rule - the parent rule that installs the state;
1968  *  cmd - opcode that installs the state;
1969  *  args - ipfw arguments;
1970  *  ulp - upper level protocol header;
1971  *  pktlen - packet length;
1972  *  info - dynamic state lookup info;
1973  *  tablearg - tablearg id.
1974  *
1975  * Returns non-zero value (failure) if state is not installed because
1976  * of errors or because session limitations are enforced.
1977  */
1978 int
1979 ipfw_dyn_install_state(struct ip_fw_chain *chain, struct ip_fw *rule,
1980     const ipfw_insn_limit *cmd, const struct ip_fw_args *args,
1981     const void *ulp, int pktlen, struct ipfw_dyn_info *info,
1982     uint32_t tablearg)
1983 {
1984         uint32_t limit;
1985         uint16_t limit_mask;
1986
1987         if (cmd->o.opcode == O_LIMIT) {
1988                 limit = IP_FW_ARG_TABLEARG(chain, cmd->conn_limit, limit);
1989                 limit_mask = cmd->limit_mask;
1990         } else {
1991                 limit = 0;
1992                 limit_mask = 0;
1993         }
1994         return (dyn_install_state(&args->f_id,
1995 #ifdef INET6
1996             IS_IP6_FLOW_ID(&args->f_id) ? dyn_getscopeid(args):
1997 #endif
1998             0, M_GETFIB(args->m), ulp, pktlen, rule, rule->id, rule->rulenum,
1999             rule->set, info, limit, limit_mask, cmd->o.arg1, cmd->o.opcode));
2000 }
2001
2002 /*
2003  * Free safe to remove state entries from expired lists.
2004  */
2005 static void
2006 dyn_free_states(struct ip_fw_chain *chain)
2007 {
2008         struct dyn_ipv4_state *s4, *s4n;
2009 #ifdef INET6
2010         struct dyn_ipv6_state *s6, *s6n;
2011 #endif
2012         int cached_count, i;
2013
2014         /*
2015          * We keep pointers to objects that are in use on each CPU
2016          * in the per-cpu dyn_hp pointer. When object is going to be
2017          * removed, first of it is unlinked from the corresponding
2018          * list. This leads to changing of dyn_bucket_xxx_delver version.
2019          * Unlinked objects is placed into corresponding dyn_expired_xxx
2020          * list. Reader that is going to dereference object pointer checks
2021          * dyn_bucket_xxx_delver version before and after storing pointer
2022          * into dyn_hp. If version is the same, the object is protected
2023          * from freeing and it is safe to dereference. Othervise reader
2024          * tries to iterate list again from the beginning, but this object
2025          * now unlinked and thus will not be accessible.
2026          *
2027          * Copy dyn_hp pointers for each CPU into dyn_hp_cache array.
2028          * It does not matter that some pointer can be changed in
2029          * time while we are copying. We need to check, that objects
2030          * removed in the previous pass are not in use. And if dyn_hp
2031          * pointer does not contain it in the time when we are copying,
2032          * it will not appear there, because it is already unlinked.
2033          * And for new pointers we will not free objects that will be
2034          * unlinked in this pass.
2035          */
2036         cached_count = 0;
2037         CPU_FOREACH(i) {
2038                 dyn_hp_cache[cached_count] = DYNSTATE_GET(i);
2039                 if (dyn_hp_cache[cached_count] != NULL)
2040                         cached_count++;
2041         }
2042
2043         /*
2044          * Free expired states that are safe to free.
2045          * Check each entry from previous pass in the dyn_expired_xxx
2046          * list, if pointer to the object is in the dyn_hp_cache array,
2047          * keep it until next pass. Otherwise it is safe to free the
2048          * object.
2049          *
2050          * XXXAE: optimize this to use SLIST_REMOVE_AFTER.
2051          */
2052 #define DYN_FREE_STATES(s, next, name)          do {                    \
2053         s = SLIST_FIRST(&V_dyn_expired_ ## name);                       \
2054         while (s != NULL) {                                             \
2055                 next = SLIST_NEXT(s, expired);                          \
2056                 for (i = 0; i < cached_count; i++)                      \
2057                         if (dyn_hp_cache[i] == s)                       \
2058                                 break;                                  \
2059                 if (i == cached_count) {                                \
2060                         if (s->type == O_LIMIT_PARENT &&                \
2061                             s->limit->count != 0) {                     \
2062                                 s = next;                               \
2063                                 continue;                               \
2064                         }                                               \
2065                         SLIST_REMOVE(&V_dyn_expired_ ## name,           \
2066                             s, dyn_ ## name ## _state, expired);        \
2067                         if (s->type == O_LIMIT_PARENT)                  \
2068                                 uma_zfree(V_dyn_parent_zone, s->limit); \
2069                         else                                            \
2070                                 uma_zfree(V_dyn_data_zone, s->data);    \
2071                         uma_zfree(V_dyn_ ## name ## _zone, s);          \
2072                 }                                                       \
2073                 s = next;                                               \
2074         }                                                               \
2075 } while (0)
2076
2077         /*
2078          * Protect access to expired lists with DYN_EXPIRED_LOCK.
2079          * Userland can invoke ipfw_expire_dyn_states() to delete
2080          * specific states, this will lead to modification of expired
2081          * lists.
2082          *
2083          * XXXAE: do we need DYN_EXPIRED_LOCK? We can just use
2084          *        IPFW_UH_WLOCK to protect access to these lists.
2085          */
2086         DYN_EXPIRED_LOCK();
2087         DYN_FREE_STATES(s4, s4n, ipv4);
2088 #ifdef INET6
2089         DYN_FREE_STATES(s6, s6n, ipv6);
2090 #endif
2091         DYN_EXPIRED_UNLOCK();
2092 #undef DYN_FREE_STATES
2093 }
2094
2095 /*
2096  * Returns 1 when state is matched by specified range, otherwise returns 0.
2097  */
2098 static int
2099 dyn_match_range(uint16_t rulenum, uint8_t set, const ipfw_range_tlv *rt)
2100 {
2101
2102         MPASS(rt != NULL);
2103         /* flush all states */
2104         if (rt->flags & IPFW_RCFLAG_ALL)
2105                 return (1);
2106         if ((rt->flags & IPFW_RCFLAG_SET) != 0 && set != rt->set)
2107                 return (0);
2108         if ((rt->flags & IPFW_RCFLAG_RANGE) != 0 &&
2109             (rulenum < rt->start_rule || rulenum > rt->end_rule))
2110                 return (0);
2111         return (1);
2112 }
2113
2114 static int
2115 dyn_match_ipv4_state(struct dyn_ipv4_state *s, const ipfw_range_tlv *rt)
2116 {
2117
2118         if (s->type == O_LIMIT_PARENT)
2119                 return (dyn_match_range(s->limit->rulenum,
2120                     s->limit->set, rt));
2121
2122         if (s->type == O_LIMIT)
2123                 return (dyn_match_range(s->data->rulenum, s->data->set, rt));
2124
2125         if (V_dyn_keep_states == 0 &&
2126             dyn_match_range(s->data->rulenum, s->data->set, rt))
2127                 return (1);
2128
2129         return (0);
2130 }
2131
2132 #ifdef INET6
2133 static int
2134 dyn_match_ipv6_state(struct dyn_ipv6_state *s, const ipfw_range_tlv *rt)
2135 {
2136
2137         if (s->type == O_LIMIT_PARENT)
2138                 return (dyn_match_range(s->limit->rulenum,
2139                     s->limit->set, rt));
2140
2141         if (s->type == O_LIMIT)
2142                 return (dyn_match_range(s->data->rulenum, s->data->set, rt));
2143
2144         if (V_dyn_keep_states == 0 &&
2145             dyn_match_range(s->data->rulenum, s->data->set, rt))
2146                 return (1);
2147
2148         return (0);
2149 }
2150 #endif
2151
2152 /*
2153  * Unlink expired entries from states lists.
2154  * @rt can be used to specify the range of states for deletion.
2155  */
2156 static void
2157 dyn_expire_states(struct ip_fw_chain *chain, ipfw_range_tlv *rt)
2158 {
2159         struct dyn_ipv4_slist expired_ipv4;
2160 #ifdef INET6
2161         struct dyn_ipv6_slist expired_ipv6;
2162         struct dyn_ipv6_state *s6, *s6n, *s6p;
2163 #endif
2164         struct dyn_ipv4_state *s4, *s4n, *s4p;
2165         int bucket, removed, length, max_length;
2166
2167         /*
2168          * Unlink expired states from each bucket.
2169          * With acquired bucket lock iterate entries of each lists:
2170          * ipv4, ipv4_parent, ipv6, and ipv6_parent. Check expired time
2171          * and unlink entry from the list, link entry into temporary
2172          * expired_xxx lists then bump "del" bucket version.
2173          *
2174          * When an entry is removed, corresponding states counter is
2175          * decremented. If entry has O_LIMIT type, parent's reference
2176          * counter is decremented.
2177          *
2178          * NOTE: this function can be called from userspace context
2179          * when user deletes rules. In this case all matched states
2180          * will be forcedly unlinked. O_LIMIT_PARENT states will be kept
2181          * in the expired lists until reference counter become zero.
2182          */
2183 #define DYN_UNLINK_STATES(s, prev, next, exp, af, name, extra)  do {    \
2184         length = 0;                                                     \
2185         removed = 0;                                                    \
2186         prev = NULL;                                                    \
2187         s = CK_SLIST_FIRST(&V_dyn_ ## name [bucket]);                   \
2188         while (s != NULL) {                                             \
2189                 next = CK_SLIST_NEXT(s, entry);                         \
2190                 if ((TIME_LEQ((s)->exp, time_uptime) && extra) ||       \
2191                     (rt != NULL && dyn_match_ ## af ## _state(s, rt))) {\
2192                         if (prev != NULL)                               \
2193                                 CK_SLIST_REMOVE_AFTER(prev, entry);     \
2194                         else                                            \
2195                                 CK_SLIST_REMOVE_HEAD(                   \
2196                                     &V_dyn_ ## name [bucket], entry);   \
2197                         removed++;                                      \
2198                         SLIST_INSERT_HEAD(&expired_ ## af, s, expired); \
2199                         if (s->type == O_LIMIT_PARENT)                  \
2200                                 DYN_COUNT_DEC(dyn_parent_count);        \
2201                         else {                                          \
2202                                 DYN_COUNT_DEC(dyn_count);               \
2203                                 if (s->type == O_LIMIT) {               \
2204                                         s = s->data->parent;            \
2205                                         DPARENT_COUNT_DEC(s->limit);    \
2206                                 }                                       \
2207                         }                                               \
2208                 } else {                                                \
2209                         prev = s;                                       \
2210                         length++;                                       \
2211                 }                                                       \
2212                 s = next;                                               \
2213         }                                                               \
2214         if (removed != 0)                                               \
2215                 DYN_BUCKET_VERSION_BUMP(bucket, name ## _del);          \
2216         if (length > max_length)                                \
2217                 max_length = length;                            \
2218 } while (0)
2219
2220         SLIST_INIT(&expired_ipv4);
2221 #ifdef INET6
2222         SLIST_INIT(&expired_ipv6);
2223 #endif
2224         max_length = 0;
2225         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
2226                 DYN_BUCKET_LOCK(bucket);
2227                 DYN_UNLINK_STATES(s4, s4p, s4n, data->expire, ipv4, ipv4, 1);
2228                 DYN_UNLINK_STATES(s4, s4p, s4n, limit->expire, ipv4,
2229                     ipv4_parent, (s4->limit->count == 0));
2230 #ifdef INET6
2231                 DYN_UNLINK_STATES(s6, s6p, s6n, data->expire, ipv6, ipv6, 1);
2232                 DYN_UNLINK_STATES(s6, s6p, s6n, limit->expire, ipv6,
2233                     ipv6_parent, (s6->limit->count == 0));
2234 #endif
2235                 DYN_BUCKET_UNLOCK(bucket);
2236         }
2237         /* Update curr_max_length for statistics. */
2238         V_curr_max_length = max_length;
2239         /*
2240          * Concatenate temporary lists with global expired lists.
2241          */
2242         DYN_EXPIRED_LOCK();
2243         SLIST_CONCAT(&V_dyn_expired_ipv4, &expired_ipv4,
2244             dyn_ipv4_state, expired);
2245 #ifdef INET6
2246         SLIST_CONCAT(&V_dyn_expired_ipv6, &expired_ipv6,
2247             dyn_ipv6_state, expired);
2248 #endif
2249         DYN_EXPIRED_UNLOCK();
2250 #undef DYN_UNLINK_STATES
2251 #undef DYN_UNREF_STATES
2252 }
2253
2254 static struct mbuf *
2255 dyn_mgethdr(int len, uint16_t fibnum)
2256 {
2257         struct mbuf *m;
2258
2259         m = m_gethdr(M_NOWAIT, MT_DATA);
2260         if (m == NULL)
2261                 return (NULL);
2262 #ifdef MAC
2263         mac_netinet_firewall_send(m);
2264 #endif
2265         M_SETFIB(m, fibnum);
2266         m->m_data += max_linkhdr;
2267         m->m_flags |= M_SKIP_FIREWALL;
2268         m->m_len = m->m_pkthdr.len = len;
2269         bzero(m->m_data, len);
2270         return (m);
2271 }
2272
2273 static void
2274 dyn_make_keepalive_ipv4(struct mbuf *m, in_addr_t src, in_addr_t dst,
2275     uint32_t seq, uint32_t ack, uint16_t sport, uint16_t dport)
2276 {
2277         struct tcphdr *tcp;
2278         struct ip *ip;
2279
2280         ip = mtod(m, struct ip *);
2281         ip->ip_v = 4;
2282         ip->ip_hl = sizeof(*ip) >> 2;
2283         ip->ip_tos = IPTOS_LOWDELAY;
2284         ip->ip_len = htons(m->m_len);
2285         ip->ip_off |= htons(IP_DF);
2286         ip->ip_ttl = V_ip_defttl;
2287         ip->ip_p = IPPROTO_TCP;
2288         ip->ip_src.s_addr = htonl(src);
2289         ip->ip_dst.s_addr = htonl(dst);
2290
2291         tcp = mtodo(m, sizeof(struct ip));
2292         tcp->th_sport = htons(sport);
2293         tcp->th_dport = htons(dport);
2294         tcp->th_off = sizeof(struct tcphdr) >> 2;
2295         tcp->th_seq = htonl(seq);
2296         tcp->th_ack = htonl(ack);
2297         tcp->th_flags = TH_ACK;
2298         tcp->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
2299             htons(sizeof(struct tcphdr) + IPPROTO_TCP));
2300
2301         m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
2302         m->m_pkthdr.csum_flags = CSUM_TCP;
2303 }
2304
2305 static void
2306 dyn_enqueue_keepalive_ipv4(struct mbufq *q, const struct dyn_ipv4_state *s)
2307 {
2308         struct mbuf *m;
2309
2310         if ((s->data->state & ACK_FWD) == 0 && s->data->ack_fwd > 0) {
2311                 m = dyn_mgethdr(sizeof(struct ip) + sizeof(struct tcphdr),
2312                     s->data->fibnum);
2313                 if (m != NULL) {
2314                         dyn_make_keepalive_ipv4(m, s->dst, s->src,
2315                             s->data->ack_fwd - 1, s->data->ack_rev,
2316                             s->dport, s->sport);
2317                         if (mbufq_enqueue(q, m)) {
2318                                 m_freem(m);
2319                                 log(LOG_DEBUG, "ipfw: limit for IPv4 "
2320                                     "keepalive queue is reached.\n");
2321                                 return;
2322                         }
2323                 }
2324         }
2325
2326         if ((s->data->state & ACK_REV) == 0 && s->data->ack_rev > 0) {
2327                 m = dyn_mgethdr(sizeof(struct ip) + sizeof(struct tcphdr),
2328                     s->data->fibnum);
2329                 if (m != NULL) {
2330                         dyn_make_keepalive_ipv4(m, s->src, s->dst,
2331                             s->data->ack_rev - 1, s->data->ack_fwd,
2332                             s->sport, s->dport);
2333                         if (mbufq_enqueue(q, m)) {
2334                                 m_freem(m);
2335                                 log(LOG_DEBUG, "ipfw: limit for IPv4 "
2336                                     "keepalive queue is reached.\n");
2337                                 return;
2338                         }
2339                 }
2340         }
2341 }
2342
2343 /*
2344  * Prepare and send keep-alive packets.
2345  */
2346 static void
2347 dyn_send_keepalive_ipv4(struct ip_fw_chain *chain)
2348 {
2349         struct mbufq q;
2350         struct mbuf *m;
2351         struct dyn_ipv4_state *s;
2352         uint32_t bucket;
2353
2354         mbufq_init(&q, DYN_KEEPALIVE_MAXQ);
2355         IPFW_UH_RLOCK(chain);
2356         /*
2357          * It is safe to not use hazard pointer and just do lockless
2358          * access to the lists, because states entries can not be deleted
2359          * while we hold IPFW_UH_RLOCK.
2360          */
2361         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
2362                 CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) {
2363                         /*
2364                          * Only established TCP connections that will
2365                          * become expired withing dyn_keepalive_interval.
2366                          */
2367                         if (s->proto != IPPROTO_TCP ||
2368                             (s->data->state & BOTH_SYN) != BOTH_SYN ||
2369                             TIME_LEQ(time_uptime + V_dyn_keepalive_interval,
2370                                 s->data->expire))
2371                                 continue;
2372                         dyn_enqueue_keepalive_ipv4(&q, s);
2373                 }
2374         }
2375         IPFW_UH_RUNLOCK(chain);
2376         while ((m = mbufq_dequeue(&q)) != NULL)
2377                 ip_output(m, NULL, NULL, 0, NULL, NULL);
2378 }
2379
2380 #ifdef INET6
2381 static void
2382 dyn_make_keepalive_ipv6(struct mbuf *m, const struct in6_addr *src,
2383     const struct in6_addr *dst, uint32_t zoneid, uint32_t seq, uint32_t ack,
2384     uint16_t sport, uint16_t dport)
2385 {
2386         struct tcphdr *tcp;
2387         struct ip6_hdr *ip6;
2388
2389         ip6 = mtod(m, struct ip6_hdr *);
2390         ip6->ip6_vfc |= IPV6_VERSION;
2391         ip6->ip6_plen = htons(sizeof(struct tcphdr));
2392         ip6->ip6_nxt = IPPROTO_TCP;
2393         ip6->ip6_hlim = IPV6_DEFHLIM;
2394         ip6->ip6_src = *src;
2395         if (IN6_IS_ADDR_LINKLOCAL(src))
2396                 ip6->ip6_src.s6_addr16[1] = htons(zoneid & 0xffff);
2397         ip6->ip6_dst = *dst;
2398         if (IN6_IS_ADDR_LINKLOCAL(dst))
2399                 ip6->ip6_dst.s6_addr16[1] = htons(zoneid & 0xffff);
2400
2401         tcp = mtodo(m, sizeof(struct ip6_hdr));
2402         tcp->th_sport = htons(sport);
2403         tcp->th_dport = htons(dport);
2404         tcp->th_off = sizeof(struct tcphdr) >> 2;
2405         tcp->th_seq = htonl(seq);
2406         tcp->th_ack = htonl(ack);
2407         tcp->th_flags = TH_ACK;
2408         tcp->th_sum = in6_cksum_pseudo(ip6, sizeof(struct tcphdr),
2409             IPPROTO_TCP, 0);
2410
2411         m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
2412         m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
2413 }
2414
2415 static void
2416 dyn_enqueue_keepalive_ipv6(struct mbufq *q, const struct dyn_ipv6_state *s)
2417 {
2418         struct mbuf *m;
2419
2420         if ((s->data->state & ACK_FWD) == 0 && s->data->ack_fwd > 0) {
2421                 m = dyn_mgethdr(sizeof(struct ip6_hdr) +
2422                     sizeof(struct tcphdr), s->data->fibnum);
2423                 if (m != NULL) {
2424                         dyn_make_keepalive_ipv6(m, &s->dst, &s->src,
2425                             s->zoneid, s->data->ack_fwd - 1, s->data->ack_rev,
2426                             s->dport, s->sport);
2427                         if (mbufq_enqueue(q, m)) {
2428                                 m_freem(m);
2429                                 log(LOG_DEBUG, "ipfw: limit for IPv6 "
2430                                     "keepalive queue is reached.\n");
2431                                 return;
2432                         }
2433                 }
2434         }
2435
2436         if ((s->data->state & ACK_REV) == 0 && s->data->ack_rev > 0) {
2437                 m = dyn_mgethdr(sizeof(struct ip6_hdr) +
2438                     sizeof(struct tcphdr), s->data->fibnum);
2439                 if (m != NULL) {
2440                         dyn_make_keepalive_ipv6(m, &s->src, &s->dst,
2441                             s->zoneid, s->data->ack_rev - 1, s->data->ack_fwd,
2442                             s->sport, s->dport);
2443                         if (mbufq_enqueue(q, m)) {
2444                                 m_freem(m);
2445                                 log(LOG_DEBUG, "ipfw: limit for IPv6 "
2446                                     "keepalive queue is reached.\n");
2447                                 return;
2448                         }
2449                 }
2450         }
2451 }
2452
2453 static void
2454 dyn_send_keepalive_ipv6(struct ip_fw_chain *chain)
2455 {
2456         struct mbufq q;
2457         struct mbuf *m;
2458         struct dyn_ipv6_state *s;
2459         uint32_t bucket;
2460
2461         mbufq_init(&q, DYN_KEEPALIVE_MAXQ);
2462         IPFW_UH_RLOCK(chain);
2463         /*
2464          * It is safe to not use hazard pointer and just do lockless
2465          * access to the lists, because states entries can not be deleted
2466          * while we hold IPFW_UH_RLOCK.
2467          */
2468         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
2469                 CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) {
2470                         /*
2471                          * Only established TCP connections that will
2472                          * become expired withing dyn_keepalive_interval.
2473                          */
2474                         if (s->proto != IPPROTO_TCP ||
2475                             (s->data->state & BOTH_SYN) != BOTH_SYN ||
2476                             TIME_LEQ(time_uptime + V_dyn_keepalive_interval,
2477                                 s->data->expire))
2478                                 continue;
2479                         dyn_enqueue_keepalive_ipv6(&q, s);
2480                 }
2481         }
2482         IPFW_UH_RUNLOCK(chain);
2483         while ((m = mbufq_dequeue(&q)) != NULL)
2484                 ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
2485 }
2486 #endif /* INET6 */
2487
2488 static void
2489 dyn_grow_hashtable(struct ip_fw_chain *chain, uint32_t new)
2490 {
2491 #ifdef INET6
2492         struct dyn_ipv6ck_slist *ipv6, *ipv6_parent;
2493         uint32_t *ipv6_add, *ipv6_del, *ipv6_parent_add, *ipv6_parent_del;
2494         struct dyn_ipv6_state *s6;
2495 #endif
2496         struct dyn_ipv4ck_slist *ipv4, *ipv4_parent;
2497         uint32_t *ipv4_add, *ipv4_del, *ipv4_parent_add, *ipv4_parent_del;
2498         struct dyn_ipv4_state *s4;
2499         struct mtx *bucket_lock;
2500         void *tmp;
2501         uint32_t bucket;
2502
2503         MPASS(powerof2(new));
2504         DYN_DEBUG("grow hash size %u -> %u", V_curr_dyn_buckets, new);
2505         /*
2506          * Allocate and initialize new lists.
2507          * XXXAE: on memory pressure this can disable callout timer.
2508          */
2509         bucket_lock = malloc(new * sizeof(struct mtx), M_IPFW,
2510             M_WAITOK | M_ZERO);
2511         ipv4 = malloc(new * sizeof(struct dyn_ipv4ck_slist), M_IPFW,
2512             M_WAITOK | M_ZERO);
2513         ipv4_parent = malloc(new * sizeof(struct dyn_ipv4ck_slist), M_IPFW,
2514             M_WAITOK | M_ZERO);
2515         ipv4_add = malloc(new * sizeof(uint32_t), M_IPFW, M_WAITOK | M_ZERO);
2516         ipv4_del = malloc(new * sizeof(uint32_t), M_IPFW, M_WAITOK | M_ZERO);
2517         ipv4_parent_add = malloc(new * sizeof(uint32_t), M_IPFW,
2518             M_WAITOK | M_ZERO);
2519         ipv4_parent_del = malloc(new * sizeof(uint32_t), M_IPFW,
2520             M_WAITOK | M_ZERO);
2521 #ifdef INET6
2522         ipv6 = malloc(new * sizeof(struct dyn_ipv6ck_slist), M_IPFW,
2523             M_WAITOK | M_ZERO);
2524         ipv6_parent = malloc(new * sizeof(struct dyn_ipv6ck_slist), M_IPFW,
2525             M_WAITOK | M_ZERO);
2526         ipv6_add = malloc(new * sizeof(uint32_t), M_IPFW, M_WAITOK | M_ZERO);
2527         ipv6_del = malloc(new * sizeof(uint32_t), M_IPFW, M_WAITOK | M_ZERO);
2528         ipv6_parent_add = malloc(new * sizeof(uint32_t), M_IPFW,
2529             M_WAITOK | M_ZERO);
2530         ipv6_parent_del = malloc(new * sizeof(uint32_t), M_IPFW,
2531             M_WAITOK | M_ZERO);
2532 #endif
2533         for (bucket = 0; bucket < new; bucket++) {
2534                 DYN_BUCKET_LOCK_INIT(bucket_lock, bucket);
2535                 CK_SLIST_INIT(&ipv4[bucket]);
2536                 CK_SLIST_INIT(&ipv4_parent[bucket]);
2537 #ifdef INET6
2538                 CK_SLIST_INIT(&ipv6[bucket]);
2539                 CK_SLIST_INIT(&ipv6_parent[bucket]);
2540 #endif
2541         }
2542
2543 #define DYN_RELINK_STATES(s, hval, i, head, ohead)      do {            \
2544         while ((s = CK_SLIST_FIRST(&V_dyn_ ## ohead[i])) != NULL) {     \
2545                 CK_SLIST_REMOVE_HEAD(&V_dyn_ ## ohead[i], entry);       \
2546                 CK_SLIST_INSERT_HEAD(&head[DYN_BUCKET(s->hval, new)],   \
2547                     s, entry);                                          \
2548         }                                                               \
2549 } while (0)
2550         /*
2551          * Prevent rules changing from userland.
2552          */
2553         IPFW_UH_WLOCK(chain);
2554         /*
2555          * Hold traffic processing until we finish resize to
2556          * prevent access to states lists.
2557          */
2558         IPFW_WLOCK(chain);
2559         /* Re-link all dynamic states */
2560         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
2561                 DYN_RELINK_STATES(s4, data->hashval, bucket, ipv4, ipv4);
2562                 DYN_RELINK_STATES(s4, limit->hashval, bucket, ipv4_parent,
2563                     ipv4_parent);
2564 #ifdef INET6
2565                 DYN_RELINK_STATES(s6, data->hashval, bucket, ipv6, ipv6);
2566                 DYN_RELINK_STATES(s6, limit->hashval, bucket, ipv6_parent,
2567                     ipv6_parent);
2568 #endif
2569         }
2570
2571 #define DYN_SWAP_PTR(old, new, tmp)     do {            \
2572         tmp = old;                                      \
2573         old = new;                                      \
2574         new = tmp;                                      \
2575 } while (0)
2576         /* Swap pointers */
2577         DYN_SWAP_PTR(V_dyn_bucket_lock, bucket_lock, tmp);
2578         DYN_SWAP_PTR(V_dyn_ipv4, ipv4, tmp);
2579         DYN_SWAP_PTR(V_dyn_ipv4_parent, ipv4_parent, tmp);
2580         DYN_SWAP_PTR(V_dyn_ipv4_add, ipv4_add, tmp);
2581         DYN_SWAP_PTR(V_dyn_ipv4_parent_add, ipv4_parent_add, tmp);
2582         DYN_SWAP_PTR(V_dyn_ipv4_del, ipv4_del, tmp);
2583         DYN_SWAP_PTR(V_dyn_ipv4_parent_del, ipv4_parent_del, tmp);
2584
2585 #ifdef INET6
2586         DYN_SWAP_PTR(V_dyn_ipv6, ipv6, tmp);
2587         DYN_SWAP_PTR(V_dyn_ipv6_parent, ipv6_parent, tmp);
2588         DYN_SWAP_PTR(V_dyn_ipv6_add, ipv6_add, tmp);
2589         DYN_SWAP_PTR(V_dyn_ipv6_parent_add, ipv6_parent_add, tmp);
2590         DYN_SWAP_PTR(V_dyn_ipv6_del, ipv6_del, tmp);
2591         DYN_SWAP_PTR(V_dyn_ipv6_parent_del, ipv6_parent_del, tmp);
2592 #endif
2593         bucket = V_curr_dyn_buckets;
2594         V_curr_dyn_buckets = new;
2595
2596         IPFW_WUNLOCK(chain);
2597         IPFW_UH_WUNLOCK(chain);
2598
2599         /* Release old resources */
2600         while (bucket-- != 0)
2601                 DYN_BUCKET_LOCK_DESTROY(bucket_lock, bucket);
2602         free(bucket_lock, M_IPFW);
2603         free(ipv4, M_IPFW);
2604         free(ipv4_parent, M_IPFW);
2605         free(ipv4_add, M_IPFW);
2606         free(ipv4_parent_add, M_IPFW);
2607         free(ipv4_del, M_IPFW);
2608         free(ipv4_parent_del, M_IPFW);
2609 #ifdef INET6
2610         free(ipv6, M_IPFW);
2611         free(ipv6_parent, M_IPFW);
2612         free(ipv6_add, M_IPFW);
2613         free(ipv6_parent_add, M_IPFW);
2614         free(ipv6_del, M_IPFW);
2615         free(ipv6_parent_del, M_IPFW);
2616 #endif
2617 }
2618
2619 /*
2620  * This function is used to perform various maintenance
2621  * on dynamic hash lists. Currently it is called every second.
2622  */
2623 static void
2624 dyn_tick(void *vnetx)
2625 {
2626         uint32_t buckets;
2627
2628         CURVNET_SET((struct vnet *)vnetx);
2629         /*
2630          * First free states unlinked in previous passes.
2631          */
2632         dyn_free_states(&V_layer3_chain);
2633         /*
2634          * Now unlink others expired states.
2635          * We use IPFW_UH_WLOCK to avoid concurrent call of
2636          * dyn_expire_states(). It is the only function that does
2637          * deletion of state entries from states lists.
2638          */
2639         IPFW_UH_WLOCK(&V_layer3_chain);
2640         dyn_expire_states(&V_layer3_chain, NULL);
2641         IPFW_UH_WUNLOCK(&V_layer3_chain);
2642         /*
2643          * Send keepalives if they are enabled and the time has come.
2644          */
2645         if (V_dyn_keepalive != 0 &&
2646             V_dyn_keepalive_last + V_dyn_keepalive_period <= time_uptime) {
2647                 V_dyn_keepalive_last = time_uptime;
2648                 dyn_send_keepalive_ipv4(&V_layer3_chain);
2649 #ifdef INET6
2650                 dyn_send_keepalive_ipv6(&V_layer3_chain);
2651 #endif
2652         }
2653         /*
2654          * Check if we need to resize the hash:
2655          * if current number of states exceeds number of buckets in hash,
2656          * and dyn_buckets_max permits to grow the number of buckets, then
2657          * do it. Grow hash size to the minimum power of 2 which is bigger
2658          * than current states count.
2659          */
2660         if (V_curr_dyn_buckets < V_dyn_buckets_max &&
2661             (V_curr_dyn_buckets < V_dyn_count / 2 || (
2662             V_curr_dyn_buckets < V_dyn_count && V_curr_max_length > 8))) {
2663                 buckets = 1 << fls(V_dyn_count);
2664                 if (buckets > V_dyn_buckets_max)
2665                         buckets = V_dyn_buckets_max;
2666                 dyn_grow_hashtable(&V_layer3_chain, buckets);
2667         }
2668
2669         callout_reset_on(&V_dyn_timeout, hz, dyn_tick, vnetx, 0);
2670         CURVNET_RESTORE();
2671 }
2672
2673 void
2674 ipfw_expire_dyn_states(struct ip_fw_chain *chain, ipfw_range_tlv *rt)
2675 {
2676         /*
2677          * Do not perform any checks if we currently have no dynamic states
2678          */
2679         if (V_dyn_count == 0)
2680                 return;
2681
2682         IPFW_UH_WLOCK_ASSERT(chain);
2683         dyn_expire_states(chain, rt);
2684 }
2685
2686 /*
2687  * Returns size of dynamic states in legacy format
2688  */
2689 int
2690 ipfw_dyn_len(void)
2691 {
2692
2693         return ((V_dyn_count + V_dyn_parent_count) * sizeof(ipfw_dyn_rule));
2694 }
2695
2696 /*
2697  * Returns number of dynamic states.
2698  * Used by dump format v1 (current).
2699  */
2700 uint32_t
2701 ipfw_dyn_get_count(void)
2702 {
2703
2704         return (V_dyn_count + V_dyn_parent_count);
2705 }
2706
2707 /*
2708  * Check if rule contains at least one dynamic opcode.
2709  *
2710  * Returns 1 if such opcode is found, 0 otherwise.
2711  */
2712 int
2713 ipfw_is_dyn_rule(struct ip_fw *rule)
2714 {
2715         int cmdlen, l;
2716         ipfw_insn *cmd;
2717
2718         l = rule->cmd_len;
2719         cmd = rule->cmd;
2720         cmdlen = 0;
2721         for ( ; l > 0 ; l -= cmdlen, cmd += cmdlen) {
2722                 cmdlen = F_LEN(cmd);
2723
2724                 switch (cmd->opcode) {
2725                 case O_LIMIT:
2726                 case O_KEEP_STATE:
2727                 case O_PROBE_STATE:
2728                 case O_CHECK_STATE:
2729                         return (1);
2730                 }
2731         }
2732
2733         return (0);
2734 }
2735
2736 static void
2737 dyn_export_parent(const struct dyn_parent *p, uint16_t kidx,
2738     ipfw_dyn_rule *dst)
2739 {
2740
2741         dst->dyn_type = O_LIMIT_PARENT;
2742         dst->kidx = kidx;
2743         dst->count = (uint16_t)DPARENT_COUNT(p);
2744         dst->expire = TIME_LEQ(p->expire, time_uptime) ?  0:
2745             p->expire - time_uptime;
2746
2747         /* 'rule' is used to pass up the rule number and set */
2748         memcpy(&dst->rule, &p->rulenum, sizeof(p->rulenum));
2749         /* store set number into high word of dst->rule pointer. */
2750         memcpy((char *)&dst->rule + sizeof(p->rulenum), &p->set,
2751             sizeof(p->set));
2752
2753         /* unused fields */
2754         dst->pcnt = 0;
2755         dst->bcnt = 0;
2756         dst->parent = NULL;
2757         dst->state = 0;
2758         dst->ack_fwd = 0;
2759         dst->ack_rev = 0;
2760         dst->bucket = p->hashval;
2761         /*
2762          * The legacy userland code will interpret a NULL here as a marker
2763          * for the last dynamic rule.
2764          */
2765         dst->next = (ipfw_dyn_rule *)1;
2766 }
2767
2768 static void
2769 dyn_export_data(const struct dyn_data *data, uint16_t kidx, uint8_t type,
2770     ipfw_dyn_rule *dst)
2771 {
2772
2773         dst->dyn_type = type;
2774         dst->kidx = kidx;
2775         dst->pcnt = data->pcnt_fwd + data->pcnt_rev;
2776         dst->bcnt = data->bcnt_fwd + data->bcnt_rev;
2777         dst->expire = TIME_LEQ(data->expire, time_uptime) ?  0:
2778             data->expire - time_uptime;
2779
2780         /* 'rule' is used to pass up the rule number and set */
2781         memcpy(&dst->rule, &data->rulenum, sizeof(data->rulenum));
2782         /* store set number into high word of dst->rule pointer. */
2783         memcpy((char *)&dst->rule + sizeof(data->rulenum), &data->set,
2784             sizeof(data->set));
2785
2786         /* unused fields */
2787         dst->parent = NULL;
2788         dst->state = data->state;
2789         dst->ack_fwd = data->ack_fwd;
2790         dst->ack_rev = data->ack_rev;
2791         dst->count = 0;
2792         dst->bucket = data->hashval;
2793         /*
2794          * The legacy userland code will interpret a NULL here as a marker
2795          * for the last dynamic rule.
2796          */
2797         dst->next = (ipfw_dyn_rule *)1;
2798 }
2799
2800 static void
2801 dyn_export_ipv4_state(const struct dyn_ipv4_state *s, ipfw_dyn_rule *dst)
2802 {
2803
2804         switch (s->type) {
2805         case O_LIMIT_PARENT:
2806                 dyn_export_parent(s->limit, s->kidx, dst);
2807                 break;
2808         default:
2809                 dyn_export_data(s->data, s->kidx, s->type, dst);
2810         }
2811
2812         dst->id.dst_ip = s->dst;
2813         dst->id.src_ip = s->src;
2814         dst->id.dst_port = s->dport;
2815         dst->id.src_port = s->sport;
2816         dst->id.fib = s->data->fibnum;
2817         dst->id.proto = s->proto;
2818         dst->id._flags = 0;
2819         dst->id.addr_type = 4;
2820
2821         memset(&dst->id.dst_ip6, 0, sizeof(dst->id.dst_ip6));
2822         memset(&dst->id.src_ip6, 0, sizeof(dst->id.src_ip6));
2823         dst->id.flow_id6 = dst->id.extra = 0;
2824 }
2825
2826 #ifdef INET6
2827 static void
2828 dyn_export_ipv6_state(const struct dyn_ipv6_state *s, ipfw_dyn_rule *dst)
2829 {
2830
2831         switch (s->type) {
2832         case O_LIMIT_PARENT:
2833                 dyn_export_parent(s->limit, s->kidx, dst);
2834                 break;
2835         default:
2836                 dyn_export_data(s->data, s->kidx, s->type, dst);
2837         }
2838
2839         dst->id.src_ip6 = s->src;
2840         dst->id.dst_ip6 = s->dst;
2841         dst->id.dst_port = s->dport;
2842         dst->id.src_port = s->sport;
2843         dst->id.fib = s->data->fibnum;
2844         dst->id.proto = s->proto;
2845         dst->id._flags = 0;
2846         dst->id.addr_type = 6;
2847
2848         dst->id.dst_ip = dst->id.src_ip = 0;
2849         dst->id.flow_id6 = dst->id.extra = 0;
2850 }
2851 #endif /* INET6 */
2852
2853 /*
2854  * Fills the buffer given by @sd with dynamic states.
2855  * Used by dump format v1 (current).
2856  *
2857  * Returns 0 on success.
2858  */
2859 int
2860 ipfw_dump_states(struct ip_fw_chain *chain, struct sockopt_data *sd)
2861 {
2862 #ifdef INET6
2863         struct dyn_ipv6_state *s6;
2864 #endif
2865         struct dyn_ipv4_state *s4;
2866         ipfw_obj_dyntlv *dst, *last;
2867         ipfw_obj_ctlv *ctlv;
2868         uint32_t bucket;
2869
2870         if (V_dyn_count == 0)
2871                 return (0);
2872
2873         /*
2874          * IPFW_UH_RLOCK garantees that another userland request
2875          * and callout thread will not delete entries from states
2876          * lists.
2877          */
2878         IPFW_UH_RLOCK_ASSERT(chain);
2879
2880         ctlv = (ipfw_obj_ctlv *)ipfw_get_sopt_space(sd, sizeof(*ctlv));
2881         if (ctlv == NULL)
2882                 return (ENOMEM);
2883         ctlv->head.type = IPFW_TLV_DYNSTATE_LIST;
2884         ctlv->objsize = sizeof(ipfw_obj_dyntlv);
2885         last = NULL;
2886
2887 #define DYN_EXPORT_STATES(s, af, h, b)                          \
2888         CK_SLIST_FOREACH(s, &V_dyn_ ## h[b], entry) {                   \
2889                 dst = (ipfw_obj_dyntlv *)ipfw_get_sopt_space(sd,        \
2890                     sizeof(ipfw_obj_dyntlv));                           \
2891                 if (dst == NULL)                                        \
2892                         return (ENOMEM);                                \
2893                 dyn_export_ ## af ## _state(s, &dst->state);            \
2894                 dst->head.length = sizeof(ipfw_obj_dyntlv);             \
2895                 dst->head.type = IPFW_TLV_DYN_ENT;                      \
2896                 last = dst;                                             \
2897         }
2898
2899         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
2900                 DYN_EXPORT_STATES(s4, ipv4, ipv4_parent, bucket);
2901                 DYN_EXPORT_STATES(s4, ipv4, ipv4, bucket);
2902 #ifdef INET6
2903                 DYN_EXPORT_STATES(s6, ipv6, ipv6_parent, bucket);
2904                 DYN_EXPORT_STATES(s6, ipv6, ipv6, bucket);
2905 #endif /* INET6 */
2906         }
2907
2908         /* mark last dynamic rule */
2909         if (last != NULL)
2910                 last->head.flags = IPFW_DF_LAST; /* XXX: unused */
2911         return (0);
2912 #undef DYN_EXPORT_STATES
2913 }
2914
2915 /*
2916  * Fill given buffer with dynamic states (legacy format).
2917  * IPFW_UH_RLOCK has to be held while calling.
2918  */
2919 void
2920 ipfw_get_dynamic(struct ip_fw_chain *chain, char **pbp, const char *ep)
2921 {
2922 #ifdef INET6
2923         struct dyn_ipv6_state *s6;
2924 #endif
2925         struct dyn_ipv4_state *s4;
2926         ipfw_dyn_rule *p, *last = NULL;
2927         char *bp;
2928         uint32_t bucket;
2929
2930         if (V_dyn_count == 0)
2931                 return;
2932         bp = *pbp;
2933
2934         IPFW_UH_RLOCK_ASSERT(chain);
2935
2936 #define DYN_EXPORT_STATES(s, af, head, b)                               \
2937         CK_SLIST_FOREACH(s, &V_dyn_ ## head[b], entry) {                \
2938                 if (bp + sizeof(*p) > ep)                               \
2939                         break;                                          \
2940                 p = (ipfw_dyn_rule *)bp;                                \
2941                 dyn_export_ ## af ## _state(s, p);                      \
2942                 last = p;                                               \
2943                 bp += sizeof(*p);                                       \
2944         }
2945
2946         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
2947                 DYN_EXPORT_STATES(s4, ipv4, ipv4_parent, bucket);
2948                 DYN_EXPORT_STATES(s4, ipv4, ipv4, bucket);
2949 #ifdef INET6
2950                 DYN_EXPORT_STATES(s6, ipv6, ipv6_parent, bucket);
2951                 DYN_EXPORT_STATES(s6, ipv6, ipv6, bucket);
2952 #endif /* INET6 */
2953         }
2954
2955         if (last != NULL) /* mark last dynamic rule */
2956                 last->next = NULL;
2957         *pbp = bp;
2958 #undef DYN_EXPORT_STATES
2959 }
2960
2961 void
2962 ipfw_dyn_init(struct ip_fw_chain *chain)
2963 {
2964
2965 #ifdef IPFIREWALL_JENKINSHASH
2966         V_dyn_hashseed = arc4random();
2967 #endif
2968         V_dyn_max = 16384;              /* max # of states */
2969         V_dyn_parent_max = 4096;        /* max # of parent states */
2970         V_dyn_buckets_max = 8192;       /* must be power of 2 */
2971
2972         V_dyn_ack_lifetime = 300;
2973         V_dyn_syn_lifetime = 20;
2974         V_dyn_fin_lifetime = 1;
2975         V_dyn_rst_lifetime = 1;
2976         V_dyn_udp_lifetime = 10;
2977         V_dyn_short_lifetime = 5;
2978
2979         V_dyn_keepalive_interval = 20;
2980         V_dyn_keepalive_period = 5;
2981         V_dyn_keepalive = 1;            /* send keepalives */
2982         V_dyn_keepalive_last = time_uptime;
2983
2984         V_dyn_data_zone = uma_zcreate("IPFW dynamic states data",
2985             sizeof(struct dyn_data), NULL, NULL, NULL, NULL,
2986             UMA_ALIGN_PTR, 0);
2987         uma_zone_set_max(V_dyn_data_zone, V_dyn_max);
2988
2989         V_dyn_parent_zone = uma_zcreate("IPFW parent dynamic states",
2990             sizeof(struct dyn_parent), NULL, NULL, NULL, NULL,
2991             UMA_ALIGN_PTR, 0);
2992         uma_zone_set_max(V_dyn_parent_zone, V_dyn_parent_max);
2993
2994         SLIST_INIT(&V_dyn_expired_ipv4);
2995         V_dyn_ipv4 = NULL;
2996         V_dyn_ipv4_parent = NULL;
2997         V_dyn_ipv4_zone = uma_zcreate("IPFW IPv4 dynamic states",
2998             sizeof(struct dyn_ipv4_state), NULL, NULL, NULL, NULL,
2999             UMA_ALIGN_PTR, 0);
3000
3001 #ifdef INET6
3002         SLIST_INIT(&V_dyn_expired_ipv6);
3003         V_dyn_ipv6 = NULL;
3004         V_dyn_ipv6_parent = NULL;
3005         V_dyn_ipv6_zone = uma_zcreate("IPFW IPv6 dynamic states",
3006             sizeof(struct dyn_ipv6_state), NULL, NULL, NULL, NULL,
3007             UMA_ALIGN_PTR, 0);
3008 #endif
3009
3010         /* Initialize buckets. */
3011         V_curr_dyn_buckets = 0;
3012         V_dyn_bucket_lock = NULL;
3013         dyn_grow_hashtable(chain, 256);
3014
3015         if (IS_DEFAULT_VNET(curvnet))
3016                 dyn_hp_cache = malloc(mp_ncpus * sizeof(void *), M_IPFW,
3017                     M_WAITOK | M_ZERO);
3018
3019         DYN_EXPIRED_LOCK_INIT();
3020         callout_init(&V_dyn_timeout, 1);
3021         callout_reset(&V_dyn_timeout, hz, dyn_tick, curvnet);
3022         IPFW_ADD_OBJ_REWRITER(IS_DEFAULT_VNET(curvnet), dyn_opcodes);
3023 }
3024
3025 void
3026 ipfw_dyn_uninit(int pass)
3027 {
3028 #ifdef INET6
3029         struct dyn_ipv6_state *s6;
3030 #endif
3031         struct dyn_ipv4_state *s4;
3032         int bucket;
3033
3034         if (pass == 0) {
3035                 callout_drain(&V_dyn_timeout);
3036                 return;
3037         }
3038         IPFW_DEL_OBJ_REWRITER(IS_DEFAULT_VNET(curvnet), dyn_opcodes);
3039         DYN_EXPIRED_LOCK_DESTROY();
3040
3041 #define DYN_FREE_STATES_FORCED(CK, s, af, name, en)     do {            \
3042         while ((s = CK ## SLIST_FIRST(&V_dyn_ ## name)) != NULL) {      \
3043                 CK ## SLIST_REMOVE_HEAD(&V_dyn_ ## name, en);   \
3044                 if (s->type == O_LIMIT_PARENT)                          \
3045                         uma_zfree(V_dyn_parent_zone, s->limit);         \
3046                 else                                                    \
3047                         uma_zfree(V_dyn_data_zone, s->data);            \
3048                 uma_zfree(V_dyn_ ## af ## _zone, s);                    \
3049         }                                                               \
3050 } while (0)
3051         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
3052                 DYN_BUCKET_LOCK_DESTROY(V_dyn_bucket_lock, bucket);
3053
3054                 DYN_FREE_STATES_FORCED(CK_, s4, ipv4, ipv4[bucket], entry);
3055                 DYN_FREE_STATES_FORCED(CK_, s4, ipv4, ipv4_parent[bucket],
3056                     entry);
3057 #ifdef INET6
3058                 DYN_FREE_STATES_FORCED(CK_, s6, ipv6, ipv6[bucket], entry);
3059                 DYN_FREE_STATES_FORCED(CK_, s6, ipv6, ipv6_parent[bucket],
3060                     entry);
3061 #endif /* INET6 */
3062         }
3063         DYN_FREE_STATES_FORCED(, s4, ipv4, expired_ipv4, expired);
3064 #ifdef INET6
3065         DYN_FREE_STATES_FORCED(, s6, ipv6, expired_ipv6, expired);
3066 #endif
3067 #undef DYN_FREE_STATES_FORCED
3068
3069         uma_zdestroy(V_dyn_ipv4_zone);
3070         uma_zdestroy(V_dyn_data_zone);
3071         uma_zdestroy(V_dyn_parent_zone);
3072 #ifdef INET6
3073         uma_zdestroy(V_dyn_ipv6_zone);
3074         free(V_dyn_ipv6, M_IPFW);
3075         free(V_dyn_ipv6_parent, M_IPFW);
3076         free(V_dyn_ipv6_add, M_IPFW);
3077         free(V_dyn_ipv6_parent_add, M_IPFW);
3078         free(V_dyn_ipv6_del, M_IPFW);
3079         free(V_dyn_ipv6_parent_del, M_IPFW);
3080 #endif
3081         free(V_dyn_bucket_lock, M_IPFW);
3082         free(V_dyn_ipv4, M_IPFW);
3083         free(V_dyn_ipv4_parent, M_IPFW);
3084         free(V_dyn_ipv4_add, M_IPFW);
3085         free(V_dyn_ipv4_parent_add, M_IPFW);
3086         free(V_dyn_ipv4_del, M_IPFW);
3087         free(V_dyn_ipv4_parent_del, M_IPFW);
3088         if (IS_DEFAULT_VNET(curvnet))
3089                 free(dyn_hp_cache, M_IPFW);
3090 }
3091
3092