1/*- 2 * Copyright (c) 2017-2018 Yandex LLC 3 * Copyright (c) 2017-2018 Andrey V. Elsukov <ae@FreeBSD.org> 4 * Copyright (c) 2002 Luigi Rizzo, Universita` di Pisa 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28#include <sys/cdefs.h> 29__FBSDID("$FreeBSD: stable/11/sys/netpfil/ipfw/ip_fw_dynamic.c 346205 2019-04-14 12:05:08Z ae $"); 30 31#include "opt_inet.h" 32#include "opt_inet6.h" 33#include "opt_ipfw.h" 34#ifndef INET 35#error IPFIREWALL requires INET. 36#endif /* INET */ 37 38#include <sys/param.h> 39#include <sys/systm.h> 40#include <sys/hash.h> 41#include <sys/mbuf.h> 42#include <sys/kernel.h> 43#include <sys/lock.h> 44#include <sys/pcpu.h> 45#include <sys/queue.h> 46#include <sys/rmlock.h> 47#include <sys/smp.h> 48#include <sys/socket.h> 49#include <sys/sysctl.h> 50#include <sys/syslog.h> 51#include <net/ethernet.h> 52#include <net/if.h> 53#include <net/if_var.h> 54#include <net/pfil.h> 55#include <net/vnet.h> 56 57#include <netinet/in.h> 58#include <netinet/ip.h> 59#include <netinet/ip_var.h> 60#include <netinet/ip_fw.h> 61#include <netinet/tcp_var.h> 62#include <netinet/udp.h> 63 64#include <netinet/ip6.h> /* IN6_ARE_ADDR_EQUAL */ 65#ifdef INET6 66#include <netinet6/in6_var.h> 67#include <netinet6/ip6_var.h> 68#include <netinet6/scope6_var.h> 69#endif 70 71#include <netpfil/ipfw/ip_fw_private.h> 72 73#include <machine/in_cksum.h> /* XXX for in_cksum */ 74 75#ifdef MAC 76#include <security/mac/mac_framework.h> 77#endif 78#include <ck_queue.h> 79 80/* 81 * Description of dynamic states. 82 * 83 * Dynamic states are stored in lists accessed through a hash tables 84 * whose size is curr_dyn_buckets. This value can be modified through 85 * the sysctl variable dyn_buckets. 86 * 87 * Currently there are four tables: dyn_ipv4, dyn_ipv6, dyn_ipv4_parent, 88 * and dyn_ipv6_parent. 89 * 90 * When a packet is received, its address fields hashed, then matched 91 * against the entries in the corresponding list by addr_type. 92 * Dynamic states can be used for different purposes: 93 * + stateful rules; 94 * + enforcing limits on the number of sessions; 95 * + in-kernel NAT (not implemented yet) 96 * 97 * The lifetime of dynamic states is regulated by dyn_*_lifetime, 98 * measured in seconds and depending on the flags. 99 * 100 * The total number of dynamic states is equal to UMA zone items count. 101 * The max number of dynamic states is dyn_max. When we reach 102 * the maximum number of rules we do not create anymore. This is 103 * done to avoid consuming too much memory, but also too much 104 * time when searching on each packet (ideally, we should try instead 105 * to put a limit on the length of the list on each bucket...). 106 * 107 * Each state holds a pointer to the parent ipfw rule so we know what 108 * action to perform. Dynamic rules are removed when the parent rule is 109 * deleted. 110 * 111 * There are some limitations with dynamic rules -- we do not 112 * obey the 'randomized match', and we do not do multiple 113 * passes through the firewall. XXX check the latter!!! 114 */ 115 116/* By default use jenkins hash function */ 117#define IPFIREWALL_JENKINSHASH 118 119#define DYN_COUNTER_INC(d, dir, pktlen) do { \ 120 (d)->pcnt_ ## dir++; \ 121 (d)->bcnt_ ## dir += pktlen; \ 122 } while (0) 123 124#define DYN_REFERENCED 0x01 125/* 126 * DYN_REFERENCED flag is used to show that state keeps reference to named 127 * object, and this reference should be released when state becomes expired. 128 */ 129 130struct dyn_data { 131 void *parent; /* pointer to parent rule */ 132 uint32_t chain_id; /* cached ruleset id */ 133 uint32_t f_pos; /* cached rule index */ 134 135 uint32_t hashval; /* hash value used for hash resize */ 136 uint16_t fibnum; /* fib used to send keepalives */ 137 uint8_t _pad[3]; 138 uint8_t flags; /* internal flags */ 139 uint16_t rulenum; /* parent rule number */ 140 uint32_t ruleid; /* parent rule id */ 141 142 uint32_t state; /* TCP session state and flags */ 143 uint32_t ack_fwd; /* most recent ACKs in forward */ 144 uint32_t ack_rev; /* and reverse direction (used */ 145 /* to generate keepalives) */ 146 uint32_t sync; /* synchronization time */ 147 uint32_t expire; /* expire time */ 148 149 uint64_t pcnt_fwd; /* bytes counter in forward */ 150 uint64_t bcnt_fwd; /* packets counter in forward */ 151 uint64_t pcnt_rev; /* bytes counter in reverse */ 152 uint64_t bcnt_rev; /* packets counter in reverse */ 153}; 154 155#define DPARENT_COUNT_DEC(p) do { \ 156 MPASS(p->count > 0); \ 157 ck_pr_dec_32(&(p)->count); \ 158} while (0) 159#define DPARENT_COUNT_INC(p) ck_pr_inc_32(&(p)->count) 160#define DPARENT_COUNT(p) ck_pr_load_32(&(p)->count) 161struct dyn_parent { 162 void *parent; /* pointer to parent rule */ 163 uint32_t count; /* number of linked states */ 164 uint8_t _pad[2]; 165 uint16_t rulenum; /* parent rule number */ 166 uint32_t ruleid; /* parent rule id */ 167 uint32_t hashval; /* hash value used for hash resize */ 168 uint32_t expire; /* expire time */ 169}; 170 171struct dyn_ipv4_state { 172 uint8_t type; /* State type */ 173 uint8_t proto; /* UL Protocol */ 174 uint16_t kidx; /* named object index */ 175 uint16_t sport, dport; /* ULP source and destination ports */ 176 in_addr_t src, dst; /* IPv4 source and destination */ 177 178 union { 179 struct dyn_data *data; 180 struct dyn_parent *limit; 181 }; 182 CK_SLIST_ENTRY(dyn_ipv4_state) entry; 183 SLIST_ENTRY(dyn_ipv4_state) expired; 184}; 185CK_SLIST_HEAD(dyn_ipv4ck_slist, dyn_ipv4_state); 186static VNET_DEFINE(struct dyn_ipv4ck_slist *, dyn_ipv4); 187static VNET_DEFINE(struct dyn_ipv4ck_slist *, dyn_ipv4_parent); 188 189SLIST_HEAD(dyn_ipv4_slist, dyn_ipv4_state); 190static VNET_DEFINE(struct dyn_ipv4_slist, dyn_expired_ipv4); 191#define V_dyn_ipv4 VNET(dyn_ipv4) 192#define V_dyn_ipv4_parent VNET(dyn_ipv4_parent) 193#define V_dyn_expired_ipv4 VNET(dyn_expired_ipv4) 194 195#ifdef INET6 196struct dyn_ipv6_state { 197 uint8_t type; /* State type */ 198 uint8_t proto; /* UL Protocol */ 199 uint16_t kidx; /* named object index */ 200 uint16_t sport, dport; /* ULP source and destination ports */ 201 struct in6_addr src, dst; /* IPv6 source and destination */ 202 uint32_t zoneid; /* IPv6 scope zone id */ 203 union { 204 struct dyn_data *data; 205 struct dyn_parent *limit; 206 }; 207 CK_SLIST_ENTRY(dyn_ipv6_state) entry; 208 SLIST_ENTRY(dyn_ipv6_state) expired; 209}; 210CK_SLIST_HEAD(dyn_ipv6ck_slist, dyn_ipv6_state); 211static VNET_DEFINE(struct dyn_ipv6ck_slist *, dyn_ipv6); 212static VNET_DEFINE(struct dyn_ipv6ck_slist *, dyn_ipv6_parent); 213 214SLIST_HEAD(dyn_ipv6_slist, dyn_ipv6_state); 215static VNET_DEFINE(struct dyn_ipv6_slist, dyn_expired_ipv6); 216#define V_dyn_ipv6 VNET(dyn_ipv6) 217#define V_dyn_ipv6_parent VNET(dyn_ipv6_parent) 218#define V_dyn_expired_ipv6 VNET(dyn_expired_ipv6) 219#endif /* INET6 */ 220 221/* 222 * Per-CPU pointer indicates that specified state is currently in use 223 * and must not be reclaimed by expiration callout. 224 */ 225static void **dyn_hp_cache; 226static DPCPU_DEFINE(void *, dyn_hp); 227#define DYNSTATE_GET(cpu) ck_pr_load_ptr(DPCPU_ID_PTR((cpu), dyn_hp)) 228#define DYNSTATE_PROTECT(v) ck_pr_store_ptr(DPCPU_PTR(dyn_hp), (v)) 229#define DYNSTATE_RELEASE() DYNSTATE_PROTECT(NULL) 230#define DYNSTATE_CRITICAL_ENTER() critical_enter() 231#define DYNSTATE_CRITICAL_EXIT() do { \ 232 DYNSTATE_RELEASE(); \ 233 critical_exit(); \ 234} while (0); 235 236/* 237 * We keep two version numbers, one is updated when new entry added to 238 * the list. Second is updated when an entry deleted from the list. 239 * Versions are updated under bucket lock. 240 * 241 * Bucket "add" version number is used to know, that in the time between 242 * state lookup (i.e. ipfw_dyn_lookup_state()) and the followed state 243 * creation (i.e. ipfw_dyn_install_state()) another concurrent thread did 244 * not install some state in this bucket. Using this info we can avoid 245 * additional state lookup, because we are sure that we will not install 246 * the state twice. 247 * 248 * Also doing the tracking of bucket "del" version during lookup we can 249 * be sure, that state entry was not unlinked and freed in time between 250 * we read the state pointer and protect it with hazard pointer. 251 * 252 * An entry unlinked from CK list keeps unchanged until it is freed. 253 * Unlinked entries are linked into expired lists using "expired" field. 254 */ 255 256/* 257 * dyn_expire_lock is used to protect access to dyn_expired_xxx lists. 258 * dyn_bucket_lock is used to get write access to lists in specific bucket. 259 * Currently one dyn_bucket_lock is used for all ipv4, ipv4_parent, ipv6, 260 * and ipv6_parent lists. 261 */ 262static VNET_DEFINE(struct mtx, dyn_expire_lock); 263static VNET_DEFINE(struct mtx *, dyn_bucket_lock); 264#define V_dyn_expire_lock VNET(dyn_expire_lock) 265#define V_dyn_bucket_lock VNET(dyn_bucket_lock) 266 267/* 268 * Bucket's add/delete generation versions. 269 */ 270static VNET_DEFINE(uint32_t *, dyn_ipv4_add); 271static VNET_DEFINE(uint32_t *, dyn_ipv4_del); 272static VNET_DEFINE(uint32_t *, dyn_ipv4_parent_add); 273static VNET_DEFINE(uint32_t *, dyn_ipv4_parent_del); 274#define V_dyn_ipv4_add VNET(dyn_ipv4_add) 275#define V_dyn_ipv4_del VNET(dyn_ipv4_del) 276#define V_dyn_ipv4_parent_add VNET(dyn_ipv4_parent_add) 277#define V_dyn_ipv4_parent_del VNET(dyn_ipv4_parent_del) 278 279#ifdef INET6 280static VNET_DEFINE(uint32_t *, dyn_ipv6_add); 281static VNET_DEFINE(uint32_t *, dyn_ipv6_del); 282static VNET_DEFINE(uint32_t *, dyn_ipv6_parent_add); 283static VNET_DEFINE(uint32_t *, dyn_ipv6_parent_del); 284#define V_dyn_ipv6_add VNET(dyn_ipv6_add) 285#define V_dyn_ipv6_del VNET(dyn_ipv6_del) 286#define V_dyn_ipv6_parent_add VNET(dyn_ipv6_parent_add) 287#define V_dyn_ipv6_parent_del VNET(dyn_ipv6_parent_del) 288#endif /* INET6 */ 289 290#define DYN_BUCKET(h, b) ((h) & (b - 1)) 291#define DYN_BUCKET_VERSION(b, v) ck_pr_load_32(&V_dyn_ ## v[(b)]) 292#define DYN_BUCKET_VERSION_BUMP(b, v) ck_pr_inc_32(&V_dyn_ ## v[(b)]) 293 294#define DYN_BUCKET_LOCK_INIT(lock, b) \ 295 mtx_init(&lock[(b)], "IPFW dynamic bucket", NULL, MTX_DEF) 296#define DYN_BUCKET_LOCK_DESTROY(lock, b) mtx_destroy(&lock[(b)]) 297#define DYN_BUCKET_LOCK(b) mtx_lock(&V_dyn_bucket_lock[(b)]) 298#define DYN_BUCKET_UNLOCK(b) mtx_unlock(&V_dyn_bucket_lock[(b)]) 299#define DYN_BUCKET_ASSERT(b) mtx_assert(&V_dyn_bucket_lock[(b)], MA_OWNED) 300 301#define DYN_EXPIRED_LOCK_INIT() \ 302 mtx_init(&V_dyn_expire_lock, "IPFW expired states list", NULL, MTX_DEF) 303#define DYN_EXPIRED_LOCK_DESTROY() mtx_destroy(&V_dyn_expire_lock) 304#define DYN_EXPIRED_LOCK() mtx_lock(&V_dyn_expire_lock) 305#define DYN_EXPIRED_UNLOCK() mtx_unlock(&V_dyn_expire_lock) 306 307static VNET_DEFINE(uint32_t, dyn_buckets_max); 308static VNET_DEFINE(uint32_t, curr_dyn_buckets); 309static VNET_DEFINE(struct callout, dyn_timeout); 310#define V_dyn_buckets_max VNET(dyn_buckets_max) 311#define V_curr_dyn_buckets VNET(curr_dyn_buckets) 312#define V_dyn_timeout VNET(dyn_timeout) 313 314/* Maximum length of states chain in a bucket */ 315static VNET_DEFINE(uint32_t, curr_max_length); 316#define V_curr_max_length VNET(curr_max_length) 317 318static VNET_DEFINE(uint32_t, dyn_keep_states); 319#define V_dyn_keep_states VNET(dyn_keep_states) 320 321static VNET_DEFINE(uma_zone_t, dyn_data_zone); 322static VNET_DEFINE(uma_zone_t, dyn_parent_zone); 323static VNET_DEFINE(uma_zone_t, dyn_ipv4_zone); 324#ifdef INET6 325static VNET_DEFINE(uma_zone_t, dyn_ipv6_zone); 326#define V_dyn_ipv6_zone VNET(dyn_ipv6_zone) 327#endif /* INET6 */ 328#define V_dyn_data_zone VNET(dyn_data_zone) 329#define V_dyn_parent_zone VNET(dyn_parent_zone) 330#define V_dyn_ipv4_zone VNET(dyn_ipv4_zone) 331 332/* 333 * Timeouts for various events in handing dynamic rules. 334 */ 335static VNET_DEFINE(uint32_t, dyn_ack_lifetime); 336static VNET_DEFINE(uint32_t, dyn_syn_lifetime); 337static VNET_DEFINE(uint32_t, dyn_fin_lifetime); 338static VNET_DEFINE(uint32_t, dyn_rst_lifetime); 339static VNET_DEFINE(uint32_t, dyn_udp_lifetime); 340static VNET_DEFINE(uint32_t, dyn_short_lifetime); 341 342#define V_dyn_ack_lifetime VNET(dyn_ack_lifetime) 343#define V_dyn_syn_lifetime VNET(dyn_syn_lifetime) 344#define V_dyn_fin_lifetime VNET(dyn_fin_lifetime) 345#define V_dyn_rst_lifetime VNET(dyn_rst_lifetime) 346#define V_dyn_udp_lifetime VNET(dyn_udp_lifetime) 347#define V_dyn_short_lifetime VNET(dyn_short_lifetime) 348 349/* 350 * Keepalives are sent if dyn_keepalive is set. They are sent every 351 * dyn_keepalive_period seconds, in the last dyn_keepalive_interval 352 * seconds of lifetime of a rule. 353 * dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower 354 * than dyn_keepalive_period. 355 */ 356static VNET_DEFINE(uint32_t, dyn_keepalive_interval); 357static VNET_DEFINE(uint32_t, dyn_keepalive_period); 358static VNET_DEFINE(uint32_t, dyn_keepalive); 359static VNET_DEFINE(time_t, dyn_keepalive_last); 360 361#define V_dyn_keepalive_interval VNET(dyn_keepalive_interval) 362#define V_dyn_keepalive_period VNET(dyn_keepalive_period) 363#define V_dyn_keepalive VNET(dyn_keepalive) 364#define V_dyn_keepalive_last VNET(dyn_keepalive_last) 365 366static VNET_DEFINE(uint32_t, dyn_max); /* max # of dynamic states */ 367static VNET_DEFINE(uint32_t, dyn_count); /* number of states */ 368static VNET_DEFINE(uint32_t, dyn_parent_max); /* max # of parent states */ 369static VNET_DEFINE(uint32_t, dyn_parent_count); /* number of parent states */ 370 371#define V_dyn_max VNET(dyn_max) 372#define V_dyn_count VNET(dyn_count) 373#define V_dyn_parent_max VNET(dyn_parent_max) 374#define V_dyn_parent_count VNET(dyn_parent_count) 375 376#define DYN_COUNT_DEC(name) do { \ 377 MPASS((V_ ## name) > 0); \ 378 ck_pr_dec_32(&(V_ ## name)); \ 379} while (0) 380#define DYN_COUNT_INC(name) ck_pr_inc_32(&(V_ ## name)) 381#define DYN_COUNT(name) ck_pr_load_32(&(V_ ## name)) 382 383static time_t last_log; /* Log ratelimiting */ 384 385/* 386 * Get/set maximum number of dynamic states in given VNET instance. 387 */ 388static int 389sysctl_dyn_max(SYSCTL_HANDLER_ARGS) 390{ 391 uint32_t nstates; 392 int error; 393 394 nstates = V_dyn_max; 395 error = sysctl_handle_32(oidp, &nstates, 0, req); 396 /* Read operation or some error */ 397 if ((error != 0) || (req->newptr == NULL)) 398 return (error); 399 400 V_dyn_max = nstates; 401 uma_zone_set_max(V_dyn_data_zone, V_dyn_max); 402 return (0); 403} 404 405static int 406sysctl_dyn_parent_max(SYSCTL_HANDLER_ARGS) 407{ 408 uint32_t nstates; 409 int error; 410 411 nstates = V_dyn_parent_max; 412 error = sysctl_handle_32(oidp, &nstates, 0, req); 413 /* Read operation or some error */ 414 if ((error != 0) || (req->newptr == NULL)) 415 return (error); 416 417 V_dyn_parent_max = nstates; 418 uma_zone_set_max(V_dyn_parent_zone, V_dyn_parent_max); 419 return (0); 420} 421 422static int 423sysctl_dyn_buckets(SYSCTL_HANDLER_ARGS) 424{ 425 uint32_t nbuckets; 426 int error; 427 428 nbuckets = V_dyn_buckets_max; 429 error = sysctl_handle_32(oidp, &nbuckets, 0, req); 430 /* Read operation or some error */ 431 if ((error != 0) || (req->newptr == NULL)) 432 return (error); 433 434 if (nbuckets > 256) 435 V_dyn_buckets_max = 1 << fls(nbuckets - 1); 436 else 437 return (EINVAL); 438 return (0); 439} 440 441SYSCTL_DECL(_net_inet_ip_fw); 442 443SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_count, 444 CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(dyn_count), 0, 445 "Current number of dynamic states."); 446SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_parent_count, 447 CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(dyn_parent_count), 0, 448 "Current number of parent states. "); 449SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets, 450 CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(curr_dyn_buckets), 0, 451 "Current number of buckets for states hash table."); 452SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, curr_max_length, 453 CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(curr_max_length), 0, 454 "Current maximum length of states chains in hash buckets."); 455SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_buckets, 456 CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_RW, 0, 0, sysctl_dyn_buckets, 457 "IU", "Max number of buckets for dynamic states hash table."); 458SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_max, 459 CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_RW, 0, 0, sysctl_dyn_max, 460 "IU", "Max number of dynamic states."); 461SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_parent_max, 462 CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_RW, 0, 0, sysctl_dyn_parent_max, 463 "IU", "Max number of parent dynamic states."); 464SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime, 465 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_ack_lifetime), 0, 466 "Lifetime of dynamic states for TCP ACK."); 467SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime, 468 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_syn_lifetime), 0, 469 "Lifetime of dynamic states for TCP SYN."); 470SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime, 471 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_fin_lifetime), 0, 472 "Lifetime of dynamic states for TCP FIN."); 473SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime, 474 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_rst_lifetime), 0, 475 "Lifetime of dynamic states for TCP RST."); 476SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime, 477 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_udp_lifetime), 0, 478 "Lifetime of dynamic states for UDP."); 479SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime, 480 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_short_lifetime), 0, 481 "Lifetime of dynamic states for other situations."); 482SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_keepalive, 483 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_keepalive), 0, 484 "Enable keepalives for dynamic states."); 485SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_keep_states, 486 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_keep_states), 0, 487 "Do not flush dynamic states on rule deletion"); 488 489 490#ifdef IPFIREWALL_DYNDEBUG 491#define DYN_DEBUG(fmt, ...) do { \ 492 printf("%s: " fmt "\n", __func__, __VA_ARGS__); \ 493} while (0) 494#else 495#define DYN_DEBUG(fmt, ...) 496#endif /* !IPFIREWALL_DYNDEBUG */ 497 498#ifdef INET6 499/* Functions to work with IPv6 states */ 500static struct dyn_ipv6_state *dyn_lookup_ipv6_state( 501 const struct ipfw_flow_id *, uint32_t, const void *, 502 struct ipfw_dyn_info *, int); 503static int dyn_lookup_ipv6_state_locked(const struct ipfw_flow_id *, 504 uint32_t, const void *, int, uint32_t, uint16_t); 505static struct dyn_ipv6_state *dyn_alloc_ipv6_state( 506 const struct ipfw_flow_id *, uint32_t, uint16_t, uint8_t); 507static int dyn_add_ipv6_state(void *, uint32_t, uint16_t, 508 const struct ipfw_flow_id *, uint32_t, const void *, int, uint32_t, 509 struct ipfw_dyn_info *, uint16_t, uint16_t, uint8_t); 510static void dyn_export_ipv6_state(const struct dyn_ipv6_state *, 511 ipfw_dyn_rule *); 512 513static uint32_t dyn_getscopeid(const struct ip_fw_args *); 514static void dyn_make_keepalive_ipv6(struct mbuf *, const struct in6_addr *, 515 const struct in6_addr *, uint32_t, uint32_t, uint32_t, uint16_t, 516 uint16_t); 517static void dyn_enqueue_keepalive_ipv6(struct mbufq *, 518 const struct dyn_ipv6_state *); 519static void dyn_send_keepalive_ipv6(struct ip_fw_chain *); 520 521static struct dyn_ipv6_state *dyn_lookup_ipv6_parent( 522 const struct ipfw_flow_id *, uint32_t, const void *, uint32_t, uint16_t, 523 uint32_t); 524static struct dyn_ipv6_state *dyn_lookup_ipv6_parent_locked( 525 const struct ipfw_flow_id *, uint32_t, const void *, uint32_t, uint16_t, 526 uint32_t); 527static struct dyn_ipv6_state *dyn_add_ipv6_parent(void *, uint32_t, uint16_t, 528 const struct ipfw_flow_id *, uint32_t, uint32_t, uint32_t, uint16_t); 529#endif /* INET6 */ 530 531/* Functions to work with limit states */ 532static void *dyn_get_parent_state(const struct ipfw_flow_id *, uint32_t, 533 struct ip_fw *, uint32_t, uint32_t, uint16_t); 534static struct dyn_ipv4_state *dyn_lookup_ipv4_parent( 535 const struct ipfw_flow_id *, const void *, uint32_t, uint16_t, uint32_t); 536static struct dyn_ipv4_state *dyn_lookup_ipv4_parent_locked( 537 const struct ipfw_flow_id *, const void *, uint32_t, uint16_t, uint32_t); 538static struct dyn_parent *dyn_alloc_parent(void *, uint32_t, uint16_t, 539 uint32_t); 540static struct dyn_ipv4_state *dyn_add_ipv4_parent(void *, uint32_t, uint16_t, 541 const struct ipfw_flow_id *, uint32_t, uint32_t, uint16_t); 542 543static void dyn_tick(void *); 544static void dyn_expire_states(struct ip_fw_chain *, ipfw_range_tlv *); 545static void dyn_free_states(struct ip_fw_chain *); 546static void dyn_export_parent(const struct dyn_parent *, uint16_t, uint8_t, 547 ipfw_dyn_rule *); 548static void dyn_export_data(const struct dyn_data *, uint16_t, uint8_t, 549 uint8_t, ipfw_dyn_rule *); 550static uint32_t dyn_update_tcp_state(struct dyn_data *, 551 const struct ipfw_flow_id *, const struct tcphdr *, int); 552static void dyn_update_proto_state(struct dyn_data *, 553 const struct ipfw_flow_id *, const void *, int, int); 554 555/* Functions to work with IPv4 states */ 556struct dyn_ipv4_state *dyn_lookup_ipv4_state(const struct ipfw_flow_id *, 557 const void *, struct ipfw_dyn_info *, int); 558static int dyn_lookup_ipv4_state_locked(const struct ipfw_flow_id *, 559 const void *, int, uint32_t, uint16_t); 560static struct dyn_ipv4_state *dyn_alloc_ipv4_state( 561 const struct ipfw_flow_id *, uint16_t, uint8_t); 562static int dyn_add_ipv4_state(void *, uint32_t, uint16_t, 563 const struct ipfw_flow_id *, const void *, int, uint32_t, 564 struct ipfw_dyn_info *, uint16_t, uint16_t, uint8_t); 565static void dyn_export_ipv4_state(const struct dyn_ipv4_state *, 566 ipfw_dyn_rule *); 567 568/* 569 * Named states support. 570 */ 571static char *default_state_name = "default"; 572struct dyn_state_obj { 573 struct named_object no; 574 char name[64]; 575}; 576 577#define DYN_STATE_OBJ(ch, cmd) \ 578 ((struct dyn_state_obj *)SRV_OBJECT(ch, (cmd)->arg1)) 579/* 580 * Classifier callback. 581 * Return 0 if opcode contains object that should be referenced 582 * or rewritten. 583 */ 584static int 585dyn_classify(ipfw_insn *cmd, uint16_t *puidx, uint8_t *ptype) 586{ 587 588 DYN_DEBUG("opcode %d, arg1 %d", cmd->opcode, cmd->arg1); 589 /* Don't rewrite "check-state any" */ 590 if (cmd->arg1 == 0 && 591 cmd->opcode == O_CHECK_STATE) 592 return (1); 593 594 *puidx = cmd->arg1; 595 *ptype = 0; 596 return (0); 597} 598 599static void 600dyn_update(ipfw_insn *cmd, uint16_t idx) 601{ 602 603 cmd->arg1 = idx; 604 DYN_DEBUG("opcode %d, arg1 %d", cmd->opcode, cmd->arg1); 605} 606 607static int 608dyn_findbyname(struct ip_fw_chain *ch, struct tid_info *ti, 609 struct named_object **pno) 610{ 611 ipfw_obj_ntlv *ntlv; 612 const char *name; 613 614 DYN_DEBUG("uidx %d", ti->uidx); 615 if (ti->uidx != 0) { 616 if (ti->tlvs == NULL) 617 return (EINVAL); 618 /* Search ntlv in the buffer provided by user */ 619 ntlv = ipfw_find_name_tlv_type(ti->tlvs, ti->tlen, ti->uidx, 620 IPFW_TLV_STATE_NAME); 621 if (ntlv == NULL) 622 return (EINVAL); 623 name = ntlv->name; 624 } else 625 name = default_state_name; 626 /* 627 * Search named object with corresponding name. 628 * Since states objects are global - ignore the set value 629 * and use zero instead. 630 */ 631 *pno = ipfw_objhash_lookup_name_type(CHAIN_TO_SRV(ch), 0, 632 IPFW_TLV_STATE_NAME, name); 633 /* 634 * We always return success here. 635 * The caller will check *pno and mark object as unresolved, 636 * then it will automatically create "default" object. 637 */ 638 return (0); 639} 640 641static struct named_object * 642dyn_findbykidx(struct ip_fw_chain *ch, uint16_t idx) 643{ 644 645 DYN_DEBUG("kidx %d", idx); 646 return (ipfw_objhash_lookup_kidx(CHAIN_TO_SRV(ch), idx)); 647} 648 649static int 650dyn_create(struct ip_fw_chain *ch, struct tid_info *ti, 651 uint16_t *pkidx) 652{ 653 struct namedobj_instance *ni; 654 struct dyn_state_obj *obj; 655 struct named_object *no; 656 ipfw_obj_ntlv *ntlv; 657 char *name; 658 659 DYN_DEBUG("uidx %d", ti->uidx); 660 if (ti->uidx != 0) { 661 if (ti->tlvs == NULL) 662 return (EINVAL); 663 ntlv = ipfw_find_name_tlv_type(ti->tlvs, ti->tlen, ti->uidx, 664 IPFW_TLV_STATE_NAME); 665 if (ntlv == NULL) 666 return (EINVAL); 667 name = ntlv->name; 668 } else 669 name = default_state_name; 670 671 ni = CHAIN_TO_SRV(ch); 672 obj = malloc(sizeof(*obj), M_IPFW, M_WAITOK | M_ZERO); 673 obj->no.name = obj->name; 674 obj->no.etlv = IPFW_TLV_STATE_NAME; 675 strlcpy(obj->name, name, sizeof(obj->name)); 676 677 IPFW_UH_WLOCK(ch); 678 no = ipfw_objhash_lookup_name_type(ni, 0, 679 IPFW_TLV_STATE_NAME, name); 680 if (no != NULL) { 681 /* 682 * Object is already created. 683 * Just return its kidx and bump refcount. 684 */ 685 *pkidx = no->kidx; 686 no->refcnt++; 687 IPFW_UH_WUNLOCK(ch); 688 free(obj, M_IPFW); 689 DYN_DEBUG("\tfound kidx %d", *pkidx); 690 return (0); 691 } 692 if (ipfw_objhash_alloc_idx(ni, &obj->no.kidx) != 0) { 693 DYN_DEBUG("\talloc_idx failed for %s", name); 694 IPFW_UH_WUNLOCK(ch); 695 free(obj, M_IPFW); 696 return (ENOSPC); 697 } 698 ipfw_objhash_add(ni, &obj->no); 699 SRV_OBJECT(ch, obj->no.kidx) = obj; 700 obj->no.refcnt++; 701 *pkidx = obj->no.kidx; 702 IPFW_UH_WUNLOCK(ch); 703 DYN_DEBUG("\tcreated kidx %d", *pkidx); 704 return (0); 705} 706 707static void 708dyn_destroy(struct ip_fw_chain *ch, struct named_object *no) 709{ 710 struct dyn_state_obj *obj; 711 712 IPFW_UH_WLOCK_ASSERT(ch); 713 714 KASSERT(no->etlv == IPFW_TLV_STATE_NAME, 715 ("%s: wrong object type %u", __func__, no->etlv)); 716 KASSERT(no->refcnt == 1, 717 ("Destroying object '%s' (type %u, idx %u) with refcnt %u", 718 no->name, no->etlv, no->kidx, no->refcnt)); 719 DYN_DEBUG("kidx %d", no->kidx); 720 obj = SRV_OBJECT(ch, no->kidx); 721 SRV_OBJECT(ch, no->kidx) = NULL; 722 ipfw_objhash_del(CHAIN_TO_SRV(ch), no); 723 ipfw_objhash_free_idx(CHAIN_TO_SRV(ch), no->kidx); 724 725 free(obj, M_IPFW); 726} 727 728static struct opcode_obj_rewrite dyn_opcodes[] = { 729 { 730 O_KEEP_STATE, IPFW_TLV_STATE_NAME, 731 dyn_classify, dyn_update, 732 dyn_findbyname, dyn_findbykidx, 733 dyn_create, dyn_destroy 734 }, 735 { 736 O_CHECK_STATE, IPFW_TLV_STATE_NAME, 737 dyn_classify, dyn_update, 738 dyn_findbyname, dyn_findbykidx, 739 dyn_create, dyn_destroy 740 }, 741 { 742 O_PROBE_STATE, IPFW_TLV_STATE_NAME, 743 dyn_classify, dyn_update, 744 dyn_findbyname, dyn_findbykidx, 745 dyn_create, dyn_destroy 746 }, 747 { 748 O_LIMIT, IPFW_TLV_STATE_NAME, 749 dyn_classify, dyn_update, 750 dyn_findbyname, dyn_findbykidx, 751 dyn_create, dyn_destroy 752 }, 753}; 754 755/* 756 * IMPORTANT: the hash function for dynamic rules must be commutative 757 * in source and destination (ip,port), because rules are bidirectional 758 * and we want to find both in the same bucket. 759 */ 760#ifndef IPFIREWALL_JENKINSHASH 761static __inline uint32_t 762hash_packet(const struct ipfw_flow_id *id) 763{ 764 uint32_t i; 765 766#ifdef INET6 767 if (IS_IP6_FLOW_ID(id)) 768 i = ntohl((id->dst_ip6.__u6_addr.__u6_addr32[2]) ^ 769 (id->dst_ip6.__u6_addr.__u6_addr32[3]) ^ 770 (id->src_ip6.__u6_addr.__u6_addr32[2]) ^ 771 (id->src_ip6.__u6_addr.__u6_addr32[3])); 772 else 773#endif /* INET6 */ 774 i = (id->dst_ip) ^ (id->src_ip); 775 i ^= (id->dst_port) ^ (id->src_port); 776 return (i); 777} 778 779static __inline uint32_t 780hash_parent(const struct ipfw_flow_id *id, const void *rule) 781{ 782 783 return (hash_packet(id) ^ ((uintptr_t)rule)); 784} 785 786#else /* IPFIREWALL_JENKINSHASH */ 787 788static VNET_DEFINE(uint32_t, dyn_hashseed); 789#define V_dyn_hashseed VNET(dyn_hashseed) 790 791static __inline int 792addrcmp4(const struct ipfw_flow_id *id) 793{ 794 795 if (id->src_ip < id->dst_ip) 796 return (0); 797 if (id->src_ip > id->dst_ip) 798 return (1); 799 if (id->src_port <= id->dst_port) 800 return (0); 801 return (1); 802} 803 804#ifdef INET6 805static __inline int 806addrcmp6(const struct ipfw_flow_id *id) 807{ 808 int ret; 809 810 ret = memcmp(&id->src_ip6, &id->dst_ip6, sizeof(struct in6_addr)); 811 if (ret < 0) 812 return (0); 813 if (ret > 0) 814 return (1); 815 if (id->src_port <= id->dst_port) 816 return (0); 817 return (1); 818} 819 820static __inline uint32_t 821hash_packet6(const struct ipfw_flow_id *id) 822{ 823 struct tuple6 { 824 struct in6_addr addr[2]; 825 uint16_t port[2]; 826 } t6; 827 828 if (addrcmp6(id) == 0) { 829 t6.addr[0] = id->src_ip6; 830 t6.addr[1] = id->dst_ip6; 831 t6.port[0] = id->src_port; 832 t6.port[1] = id->dst_port; 833 } else { 834 t6.addr[0] = id->dst_ip6; 835 t6.addr[1] = id->src_ip6; 836 t6.port[0] = id->dst_port; 837 t6.port[1] = id->src_port; 838 } 839 return (jenkins_hash32((const uint32_t *)&t6, 840 sizeof(t6) / sizeof(uint32_t), V_dyn_hashseed)); 841} 842#endif 843 844static __inline uint32_t 845hash_packet(const struct ipfw_flow_id *id) 846{ 847 struct tuple4 { 848 in_addr_t addr[2]; 849 uint16_t port[2]; 850 } t4; 851 852 if (IS_IP4_FLOW_ID(id)) { 853 /* All fields are in host byte order */ 854 if (addrcmp4(id) == 0) { 855 t4.addr[0] = id->src_ip; 856 t4.addr[1] = id->dst_ip; 857 t4.port[0] = id->src_port; 858 t4.port[1] = id->dst_port; 859 } else { 860 t4.addr[0] = id->dst_ip; 861 t4.addr[1] = id->src_ip; 862 t4.port[0] = id->dst_port; 863 t4.port[1] = id->src_port; 864 } 865 return (jenkins_hash32((const uint32_t *)&t4, 866 sizeof(t4) / sizeof(uint32_t), V_dyn_hashseed)); 867 } else 868#ifdef INET6 869 if (IS_IP6_FLOW_ID(id)) 870 return (hash_packet6(id)); 871#endif 872 return (0); 873} 874 875static __inline uint32_t 876hash_parent(const struct ipfw_flow_id *id, const void *rule) 877{ 878 879 return (jenkins_hash32((const uint32_t *)&rule, 880 sizeof(rule) / sizeof(uint32_t), hash_packet(id))); 881} 882#endif /* IPFIREWALL_JENKINSHASH */ 883 884/* 885 * Print customizable flow id description via log(9) facility. 886 */ 887static void 888print_dyn_rule_flags(const struct ipfw_flow_id *id, int dyn_type, 889 int log_flags, char *prefix, char *postfix) 890{ 891 struct in_addr da; 892#ifdef INET6 893 char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN]; 894#else 895 char src[INET_ADDRSTRLEN], dst[INET_ADDRSTRLEN]; 896#endif 897 898#ifdef INET6 899 if (IS_IP6_FLOW_ID(id)) { 900 ip6_sprintf(src, &id->src_ip6); 901 ip6_sprintf(dst, &id->dst_ip6); 902 } else 903#endif 904 { 905 da.s_addr = htonl(id->src_ip); 906 inet_ntop(AF_INET, &da, src, sizeof(src)); 907 da.s_addr = htonl(id->dst_ip); 908 inet_ntop(AF_INET, &da, dst, sizeof(dst)); 909 } 910 log(log_flags, "ipfw: %s type %d %s %d -> %s %d, %d %s\n", 911 prefix, dyn_type, src, id->src_port, dst, 912 id->dst_port, V_dyn_count, postfix); 913} 914 915#define print_dyn_rule(id, dtype, prefix, postfix) \ 916 print_dyn_rule_flags(id, dtype, LOG_DEBUG, prefix, postfix) 917 918#define TIME_LEQ(a,b) ((int)((a)-(b)) <= 0) 919#define TIME_LE(a,b) ((int)((a)-(b)) < 0) 920#define _SEQ_GE(a,b) ((int)((a)-(b)) >= 0) 921#define BOTH_SYN (TH_SYN | (TH_SYN << 8)) 922#define BOTH_FIN (TH_FIN | (TH_FIN << 8)) 923#define TCP_FLAGS (TH_FLAGS | (TH_FLAGS << 8)) 924#define ACK_FWD 0x00010000 /* fwd ack seen */ 925#define ACK_REV 0x00020000 /* rev ack seen */ 926#define ACK_BOTH (ACK_FWD | ACK_REV) 927 928static uint32_t 929dyn_update_tcp_state(struct dyn_data *data, const struct ipfw_flow_id *pkt, 930 const struct tcphdr *tcp, int dir) 931{ 932 uint32_t ack, expire; 933 uint32_t state, old; 934 uint8_t th_flags; 935 936 expire = data->expire; 937 old = state = data->state; 938 th_flags = pkt->_flags & (TH_FIN | TH_SYN | TH_RST); 939 state |= (dir == MATCH_FORWARD) ? th_flags: (th_flags << 8); 940 switch (state & TCP_FLAGS) { 941 case TH_SYN: /* opening */ 942 expire = time_uptime + V_dyn_syn_lifetime; 943 break; 944 945 case BOTH_SYN: /* move to established */ 946 case BOTH_SYN | TH_FIN: /* one side tries to close */ 947 case BOTH_SYN | (TH_FIN << 8): 948 if (tcp == NULL) 949 break; 950 ack = ntohl(tcp->th_ack); 951 if (dir == MATCH_FORWARD) { 952 if (data->ack_fwd == 0 || 953 _SEQ_GE(ack, data->ack_fwd)) { 954 state |= ACK_FWD; 955 if (data->ack_fwd != ack) 956 ck_pr_store_32(&data->ack_fwd, ack); 957 } 958 } else { 959 if (data->ack_rev == 0 || 960 _SEQ_GE(ack, data->ack_rev)) { 961 state |= ACK_REV; 962 if (data->ack_rev != ack) 963 ck_pr_store_32(&data->ack_rev, ack); 964 } 965 } 966 if ((state & ACK_BOTH) == ACK_BOTH) { 967 /* 968 * Set expire time to V_dyn_ack_lifetime only if 969 * we got ACKs for both directions. 970 * We use XOR here to avoid possible state 971 * overwriting in concurrent thread. 972 */ 973 expire = time_uptime + V_dyn_ack_lifetime; 974 ck_pr_xor_32(&data->state, ACK_BOTH); 975 } else if ((data->state & ACK_BOTH) != (state & ACK_BOTH)) 976 ck_pr_or_32(&data->state, state & ACK_BOTH); 977 break; 978 979 case BOTH_SYN | BOTH_FIN: /* both sides closed */ 980 if (V_dyn_fin_lifetime >= V_dyn_keepalive_period) 981 V_dyn_fin_lifetime = V_dyn_keepalive_period - 1; 982 expire = time_uptime + V_dyn_fin_lifetime; 983 break; 984 985 default: 986 if (V_dyn_keepalive != 0 && 987 V_dyn_rst_lifetime >= V_dyn_keepalive_period) 988 V_dyn_rst_lifetime = V_dyn_keepalive_period - 1; 989 expire = time_uptime + V_dyn_rst_lifetime; 990 } 991 /* Save TCP state if it was changed */ 992 if ((state & TCP_FLAGS) != (old & TCP_FLAGS)) 993 ck_pr_or_32(&data->state, state & TCP_FLAGS); 994 return (expire); 995} 996 997/* 998 * Update ULP specific state. 999 * For TCP we keep sequence numbers and flags. For other protocols 1000 * currently we update only expire time. Packets and bytes counters 1001 * are also updated here. 1002 */ 1003static void 1004dyn_update_proto_state(struct dyn_data *data, const struct ipfw_flow_id *pkt, 1005 const void *ulp, int pktlen, int dir) 1006{ 1007 uint32_t expire; 1008 1009 /* NOTE: we are in critical section here. */ 1010 switch (pkt->proto) { 1011 case IPPROTO_UDP: 1012 case IPPROTO_UDPLITE: 1013 expire = time_uptime + V_dyn_udp_lifetime; 1014 break; 1015 case IPPROTO_TCP: 1016 expire = dyn_update_tcp_state(data, pkt, ulp, dir); 1017 break; 1018 default: 1019 expire = time_uptime + V_dyn_short_lifetime; 1020 } 1021 /* 1022 * Expiration timer has the per-second granularity, no need to update 1023 * it every time when state is matched. 1024 */ 1025 if (data->expire != expire) 1026 ck_pr_store_32(&data->expire, expire); 1027 1028 if (dir == MATCH_FORWARD) 1029 DYN_COUNTER_INC(data, fwd, pktlen); 1030 else 1031 DYN_COUNTER_INC(data, rev, pktlen); 1032} 1033 1034/* 1035 * Lookup IPv4 state. 1036 * Must be called in critical section. 1037 */ 1038struct dyn_ipv4_state * 1039dyn_lookup_ipv4_state(const struct ipfw_flow_id *pkt, const void *ulp, 1040 struct ipfw_dyn_info *info, int pktlen) 1041{ 1042 struct dyn_ipv4_state *s; 1043 uint32_t version, bucket; 1044 1045 bucket = DYN_BUCKET(info->hashval, V_curr_dyn_buckets); 1046 info->version = DYN_BUCKET_VERSION(bucket, ipv4_add); 1047restart: 1048 version = DYN_BUCKET_VERSION(bucket, ipv4_del); 1049 CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) { 1050 DYNSTATE_PROTECT(s); 1051 if (version != DYN_BUCKET_VERSION(bucket, ipv4_del)) 1052 goto restart; 1053 if (s->proto != pkt->proto) 1054 continue; 1055 if (info->kidx != 0 && s->kidx != info->kidx) 1056 continue; 1057 if (s->sport == pkt->src_port && s->dport == pkt->dst_port && 1058 s->src == pkt->src_ip && s->dst == pkt->dst_ip) { 1059 info->direction = MATCH_FORWARD; 1060 break; 1061 } 1062 if (s->sport == pkt->dst_port && s->dport == pkt->src_port && 1063 s->src == pkt->dst_ip && s->dst == pkt->src_ip) { 1064 info->direction = MATCH_REVERSE; 1065 break; 1066 } 1067 } 1068 1069 if (s != NULL) 1070 dyn_update_proto_state(s->data, pkt, ulp, pktlen, 1071 info->direction); 1072 return (s); 1073} 1074 1075/* 1076 * Lookup IPv4 state. 1077 * Simplifed version is used to check that matching state doesn't exist. 1078 */ 1079static int 1080dyn_lookup_ipv4_state_locked(const struct ipfw_flow_id *pkt, 1081 const void *ulp, int pktlen, uint32_t bucket, uint16_t kidx) 1082{ 1083 struct dyn_ipv4_state *s; 1084 int dir; 1085 1086 dir = MATCH_NONE; 1087 DYN_BUCKET_ASSERT(bucket); 1088 CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) { 1089 if (s->proto != pkt->proto || 1090 s->kidx != kidx) 1091 continue; 1092 if (s->sport == pkt->src_port && 1093 s->dport == pkt->dst_port && 1094 s->src == pkt->src_ip && s->dst == pkt->dst_ip) { 1095 dir = MATCH_FORWARD; 1096 break; 1097 } 1098 if (s->sport == pkt->dst_port && s->dport == pkt->src_port && 1099 s->src == pkt->dst_ip && s->dst == pkt->src_ip) { 1100 dir = MATCH_REVERSE; 1101 break; 1102 } 1103 } 1104 if (s != NULL) 1105 dyn_update_proto_state(s->data, pkt, ulp, pktlen, dir); 1106 return (s != NULL); 1107} 1108 1109struct dyn_ipv4_state * 1110dyn_lookup_ipv4_parent(const struct ipfw_flow_id *pkt, const void *rule, 1111 uint32_t ruleid, uint16_t rulenum, uint32_t hashval) 1112{ 1113 struct dyn_ipv4_state *s; 1114 uint32_t version, bucket; 1115 1116 bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets); 1117restart: 1118 version = DYN_BUCKET_VERSION(bucket, ipv4_parent_del); 1119 CK_SLIST_FOREACH(s, &V_dyn_ipv4_parent[bucket], entry) { 1120 DYNSTATE_PROTECT(s); 1121 if (version != DYN_BUCKET_VERSION(bucket, ipv4_parent_del)) 1122 goto restart; 1123 /* 1124 * NOTE: we do not need to check kidx, because parent rule 1125 * can not create states with different kidx. 1126 * And parent rule always created for forward direction. 1127 */ 1128 if (s->limit->parent == rule && 1129 s->limit->ruleid == ruleid && 1130 s->limit->rulenum == rulenum && 1131 s->proto == pkt->proto && 1132 s->sport == pkt->src_port && 1133 s->dport == pkt->dst_port && 1134 s->src == pkt->src_ip && s->dst == pkt->dst_ip) { 1135 if (s->limit->expire != time_uptime + 1136 V_dyn_short_lifetime) 1137 ck_pr_store_32(&s->limit->expire, 1138 time_uptime + V_dyn_short_lifetime); 1139 break; 1140 } 1141 } 1142 return (s); 1143} 1144 1145static struct dyn_ipv4_state * 1146dyn_lookup_ipv4_parent_locked(const struct ipfw_flow_id *pkt, 1147 const void *rule, uint32_t ruleid, uint16_t rulenum, uint32_t bucket) 1148{ 1149 struct dyn_ipv4_state *s; 1150 1151 DYN_BUCKET_ASSERT(bucket); 1152 CK_SLIST_FOREACH(s, &V_dyn_ipv4_parent[bucket], entry) { 1153 if (s->limit->parent == rule && 1154 s->limit->ruleid == ruleid && 1155 s->limit->rulenum == rulenum && 1156 s->proto == pkt->proto && 1157 s->sport == pkt->src_port && 1158 s->dport == pkt->dst_port && 1159 s->src == pkt->src_ip && s->dst == pkt->dst_ip) 1160 break; 1161 } 1162 return (s); 1163} 1164 1165 1166#ifdef INET6 1167static uint32_t 1168dyn_getscopeid(const struct ip_fw_args *args) 1169{ 1170 1171 /* 1172 * If source or destination address is an scopeid address, we need 1173 * determine the scope zone id to resolve address scope ambiguity. 1174 */ 1175 if (IN6_IS_ADDR_LINKLOCAL(&args->f_id.src_ip6) || 1176 IN6_IS_ADDR_LINKLOCAL(&args->f_id.dst_ip6)) { 1177 MPASS(args->oif != NULL || 1178 args->m->m_pkthdr.rcvif != NULL); 1179 return (in6_getscopezone(args->oif != NULL ? args->oif: 1180 args->m->m_pkthdr.rcvif, IPV6_ADDR_SCOPE_LINKLOCAL)); 1181 } 1182 return (0); 1183} 1184 1185/* 1186 * Lookup IPv6 state. 1187 * Must be called in critical section. 1188 */ 1189static struct dyn_ipv6_state * 1190dyn_lookup_ipv6_state(const struct ipfw_flow_id *pkt, uint32_t zoneid, 1191 const void *ulp, struct ipfw_dyn_info *info, int pktlen) 1192{ 1193 struct dyn_ipv6_state *s; 1194 uint32_t version, bucket; 1195 1196 bucket = DYN_BUCKET(info->hashval, V_curr_dyn_buckets); 1197 info->version = DYN_BUCKET_VERSION(bucket, ipv6_add); 1198restart: 1199 version = DYN_BUCKET_VERSION(bucket, ipv6_del); 1200 CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) { 1201 DYNSTATE_PROTECT(s); 1202 if (version != DYN_BUCKET_VERSION(bucket, ipv6_del)) 1203 goto restart; 1204 if (s->proto != pkt->proto || s->zoneid != zoneid) 1205 continue; 1206 if (info->kidx != 0 && s->kidx != info->kidx) 1207 continue; 1208 if (s->sport == pkt->src_port && s->dport == pkt->dst_port && 1209 IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) && 1210 IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) { 1211 info->direction = MATCH_FORWARD; 1212 break; 1213 } 1214 if (s->sport == pkt->dst_port && s->dport == pkt->src_port && 1215 IN6_ARE_ADDR_EQUAL(&s->src, &pkt->dst_ip6) && 1216 IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->src_ip6)) { 1217 info->direction = MATCH_REVERSE; 1218 break; 1219 } 1220 } 1221 if (s != NULL) 1222 dyn_update_proto_state(s->data, pkt, ulp, pktlen, 1223 info->direction); 1224 return (s); 1225} 1226 1227/* 1228 * Lookup IPv6 state. 1229 * Simplifed version is used to check that matching state doesn't exist. 1230 */ 1231static int 1232dyn_lookup_ipv6_state_locked(const struct ipfw_flow_id *pkt, uint32_t zoneid, 1233 const void *ulp, int pktlen, uint32_t bucket, uint16_t kidx) 1234{ 1235 struct dyn_ipv6_state *s; 1236 int dir; 1237 1238 dir = MATCH_NONE; 1239 DYN_BUCKET_ASSERT(bucket); 1240 CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) { 1241 if (s->proto != pkt->proto || s->kidx != kidx || 1242 s->zoneid != zoneid) 1243 continue; 1244 if (s->sport == pkt->src_port && s->dport == pkt->dst_port && 1245 IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) && 1246 IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) { 1247 dir = MATCH_FORWARD; 1248 break; 1249 } 1250 if (s->sport == pkt->dst_port && s->dport == pkt->src_port && 1251 IN6_ARE_ADDR_EQUAL(&s->src, &pkt->dst_ip6) && 1252 IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->src_ip6)) { 1253 dir = MATCH_REVERSE; 1254 break; 1255 } 1256 } 1257 if (s != NULL) 1258 dyn_update_proto_state(s->data, pkt, ulp, pktlen, dir); 1259 return (s != NULL); 1260} 1261 1262static struct dyn_ipv6_state * 1263dyn_lookup_ipv6_parent(const struct ipfw_flow_id *pkt, uint32_t zoneid, 1264 const void *rule, uint32_t ruleid, uint16_t rulenum, uint32_t hashval) 1265{ 1266 struct dyn_ipv6_state *s; 1267 uint32_t version, bucket; 1268 1269 bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets); 1270restart: 1271 version = DYN_BUCKET_VERSION(bucket, ipv6_parent_del); 1272 CK_SLIST_FOREACH(s, &V_dyn_ipv6_parent[bucket], entry) { 1273 DYNSTATE_PROTECT(s); 1274 if (version != DYN_BUCKET_VERSION(bucket, ipv6_parent_del)) 1275 goto restart; 1276 /* 1277 * NOTE: we do not need to check kidx, because parent rule 1278 * can not create states with different kidx. 1279 * Also parent rule always created for forward direction. 1280 */ 1281 if (s->limit->parent == rule && 1282 s->limit->ruleid == ruleid && 1283 s->limit->rulenum == rulenum && 1284 s->proto == pkt->proto && 1285 s->sport == pkt->src_port && 1286 s->dport == pkt->dst_port && s->zoneid == zoneid && 1287 IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) && 1288 IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) { 1289 if (s->limit->expire != time_uptime + 1290 V_dyn_short_lifetime) 1291 ck_pr_store_32(&s->limit->expire, 1292 time_uptime + V_dyn_short_lifetime); 1293 break; 1294 } 1295 } 1296 return (s); 1297} 1298 1299static struct dyn_ipv6_state * 1300dyn_lookup_ipv6_parent_locked(const struct ipfw_flow_id *pkt, uint32_t zoneid, 1301 const void *rule, uint32_t ruleid, uint16_t rulenum, uint32_t bucket) 1302{ 1303 struct dyn_ipv6_state *s; 1304 1305 DYN_BUCKET_ASSERT(bucket); 1306 CK_SLIST_FOREACH(s, &V_dyn_ipv6_parent[bucket], entry) { 1307 if (s->limit->parent == rule && 1308 s->limit->ruleid == ruleid && 1309 s->limit->rulenum == rulenum && 1310 s->proto == pkt->proto && 1311 s->sport == pkt->src_port && 1312 s->dport == pkt->dst_port && s->zoneid == zoneid && 1313 IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) && 1314 IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) 1315 break; 1316 } 1317 return (s); 1318} 1319 1320#endif /* INET6 */ 1321 1322/* 1323 * Lookup dynamic state. 1324 * pkt - filled by ipfw_chk() ipfw_flow_id; 1325 * ulp - determined by ipfw_chk() upper level protocol header; 1326 * dyn_info - info about matched state to return back; 1327 * Returns pointer to state's parent rule and dyn_info. If there is 1328 * no state, NULL is returned. 1329 * On match ipfw_dyn_lookup() updates state's counters. 1330 */ 1331struct ip_fw * 1332ipfw_dyn_lookup_state(const struct ip_fw_args *args, const void *ulp, 1333 int pktlen, const ipfw_insn *cmd, struct ipfw_dyn_info *info) 1334{ 1335 struct dyn_data *data; 1336 struct ip_fw *rule; 1337 1338 IPFW_RLOCK_ASSERT(&V_layer3_chain); 1339 1340 data = NULL; 1341 rule = NULL; 1342 info->kidx = cmd->arg1; 1343 info->direction = MATCH_NONE; 1344 info->hashval = hash_packet(&args->f_id); 1345 1346 DYNSTATE_CRITICAL_ENTER(); 1347 if (IS_IP4_FLOW_ID(&args->f_id)) { 1348 struct dyn_ipv4_state *s; 1349 1350 s = dyn_lookup_ipv4_state(&args->f_id, ulp, info, pktlen); 1351 if (s != NULL) { 1352 /* 1353 * Dynamic states are created using the same 5-tuple, 1354 * so it is assumed, that parent rule for O_LIMIT 1355 * state has the same address family. 1356 */ 1357 data = s->data; 1358 if (s->type == O_LIMIT) { 1359 s = data->parent; 1360 rule = s->limit->parent; 1361 } else 1362 rule = data->parent; 1363 } 1364 } 1365#ifdef INET6 1366 else if (IS_IP6_FLOW_ID(&args->f_id)) { 1367 struct dyn_ipv6_state *s; 1368 1369 s = dyn_lookup_ipv6_state(&args->f_id, dyn_getscopeid(args), 1370 ulp, info, pktlen); 1371 if (s != NULL) { 1372 data = s->data; 1373 if (s->type == O_LIMIT) { 1374 s = data->parent; 1375 rule = s->limit->parent; 1376 } else 1377 rule = data->parent; 1378 } 1379 } 1380#endif 1381 if (data != NULL) { 1382 /* 1383 * If cached chain id is the same, we can avoid rule index 1384 * lookup. Otherwise do lookup and update chain_id and f_pos. 1385 * It is safe even if there is concurrent thread that want 1386 * update the same state, because chain->id can be changed 1387 * only under IPFW_WLOCK(). 1388 */ 1389 if (data->chain_id != V_layer3_chain.id) { 1390 data->f_pos = ipfw_find_rule(&V_layer3_chain, 1391 data->rulenum, data->ruleid); 1392 /* 1393 * Check that found state has not orphaned. 1394 * When chain->id being changed the parent 1395 * rule can be deleted. If found rule doesn't 1396 * match the parent pointer, consider this 1397 * result as MATCH_NONE and return NULL. 1398 * 1399 * This will lead to creation of new similar state 1400 * that will be added into head of this bucket. 1401 * And the state that we currently have matched 1402 * should be deleted by dyn_expire_states(). 1403 * 1404 * In case when dyn_keep_states is enabled, return 1405 * pointer to deleted rule and f_pos value 1406 * corresponding to penultimate rule. 1407 * When we have enabled V_dyn_keep_states, states 1408 * that become orphaned will get the DYN_REFERENCED 1409 * flag and rule will keep around. So we can return 1410 * it. But since it is not in the rules map, we need 1411 * return such f_pos value, so after the state 1412 * handling if the search will continue, the next rule 1413 * will be the last one - the default rule. 1414 */ 1415 if (V_layer3_chain.map[data->f_pos] == rule) { 1416 data->chain_id = V_layer3_chain.id; 1417 info->f_pos = data->f_pos; 1418 } else if (V_dyn_keep_states != 0) { 1419 /* 1420 * The original rule pointer is still usable. 1421 * So, we return it, but f_pos need to be 1422 * changed to point to the penultimate rule. 1423 */ 1424 MPASS(V_layer3_chain.n_rules > 1); 1425 data->chain_id = V_layer3_chain.id; 1426 data->f_pos = V_layer3_chain.n_rules - 2; 1427 info->f_pos = data->f_pos; 1428 } else { 1429 rule = NULL; 1430 info->direction = MATCH_NONE; 1431 DYN_DEBUG("rule %p [%u, %u] is considered " 1432 "invalid in data %p", rule, data->ruleid, 1433 data->rulenum, data); 1434 /* info->f_pos doesn't matter here. */ 1435 } 1436 } else 1437 info->f_pos = data->f_pos; 1438 } 1439 DYNSTATE_CRITICAL_EXIT(); 1440#if 0 1441 /* 1442 * Return MATCH_NONE if parent rule is in disabled set. 1443 * This will lead to creation of new similar state that 1444 * will be added into head of this bucket. 1445 * 1446 * XXXAE: we need to be able update state's set when parent 1447 * rule set is changed. 1448 */ 1449 if (rule != NULL && (V_set_disable & (1 << rule->set))) { 1450 rule = NULL; 1451 info->direction = MATCH_NONE; 1452 } 1453#endif 1454 return (rule); 1455} 1456 1457static struct dyn_parent * 1458dyn_alloc_parent(void *parent, uint32_t ruleid, uint16_t rulenum, 1459 uint32_t hashval) 1460{ 1461 struct dyn_parent *limit; 1462 1463 limit = uma_zalloc(V_dyn_parent_zone, M_NOWAIT | M_ZERO); 1464 if (limit == NULL) { 1465 if (last_log != time_uptime) { 1466 last_log = time_uptime; 1467 log(LOG_DEBUG, 1468 "ipfw: Cannot allocate parent dynamic state, " 1469 "consider increasing " 1470 "net.inet.ip.fw.dyn_parent_max\n"); 1471 } 1472 return (NULL); 1473 } 1474 1475 limit->parent = parent; 1476 limit->ruleid = ruleid; 1477 limit->rulenum = rulenum; 1478 limit->hashval = hashval; 1479 limit->expire = time_uptime + V_dyn_short_lifetime; 1480 return (limit); 1481} 1482 1483static struct dyn_data * 1484dyn_alloc_dyndata(void *parent, uint32_t ruleid, uint16_t rulenum, 1485 const struct ipfw_flow_id *pkt, const void *ulp, int pktlen, 1486 uint32_t hashval, uint16_t fibnum) 1487{ 1488 struct dyn_data *data; 1489 1490 data = uma_zalloc(V_dyn_data_zone, M_NOWAIT | M_ZERO); 1491 if (data == NULL) { 1492 if (last_log != time_uptime) { 1493 last_log = time_uptime; 1494 log(LOG_DEBUG, 1495 "ipfw: Cannot allocate dynamic state, " 1496 "consider increasing net.inet.ip.fw.dyn_max\n"); 1497 } 1498 return (NULL); 1499 } 1500 1501 data->parent = parent; 1502 data->ruleid = ruleid; 1503 data->rulenum = rulenum; 1504 data->fibnum = fibnum; 1505 data->hashval = hashval; 1506 data->expire = time_uptime + V_dyn_syn_lifetime; 1507 dyn_update_proto_state(data, pkt, ulp, pktlen, MATCH_FORWARD); 1508 return (data); 1509} 1510 1511static struct dyn_ipv4_state * 1512dyn_alloc_ipv4_state(const struct ipfw_flow_id *pkt, uint16_t kidx, 1513 uint8_t type) 1514{ 1515 struct dyn_ipv4_state *s; 1516 1517 s = uma_zalloc(V_dyn_ipv4_zone, M_NOWAIT | M_ZERO); 1518 if (s == NULL) 1519 return (NULL); 1520 1521 s->type = type; 1522 s->kidx = kidx; 1523 s->proto = pkt->proto; 1524 s->sport = pkt->src_port; 1525 s->dport = pkt->dst_port; 1526 s->src = pkt->src_ip; 1527 s->dst = pkt->dst_ip; 1528 return (s); 1529} 1530 1531/* 1532 * Add IPv4 parent state. 1533 * Returns pointer to parent state. When it is not NULL we are in 1534 * critical section and pointer protected by hazard pointer. 1535 * When some error occurs, it returns NULL and exit from critical section 1536 * is not needed. 1537 */ 1538static struct dyn_ipv4_state * 1539dyn_add_ipv4_parent(void *rule, uint32_t ruleid, uint16_t rulenum, 1540 const struct ipfw_flow_id *pkt, uint32_t hashval, uint32_t version, 1541 uint16_t kidx) 1542{ 1543 struct dyn_ipv4_state *s; 1544 struct dyn_parent *limit; 1545 uint32_t bucket; 1546 1547 bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets); 1548 DYN_BUCKET_LOCK(bucket); 1549 if (version != DYN_BUCKET_VERSION(bucket, ipv4_parent_add)) { 1550 /* 1551 * Bucket version has been changed since last lookup, 1552 * do lookup again to be sure that state does not exist. 1553 */ 1554 s = dyn_lookup_ipv4_parent_locked(pkt, rule, ruleid, 1555 rulenum, bucket); 1556 if (s != NULL) { 1557 /* 1558 * Simultaneous thread has already created this 1559 * state. Just return it. 1560 */ 1561 DYNSTATE_CRITICAL_ENTER(); 1562 DYNSTATE_PROTECT(s); 1563 DYN_BUCKET_UNLOCK(bucket); 1564 return (s); 1565 } 1566 } 1567 1568 limit = dyn_alloc_parent(rule, ruleid, rulenum, hashval); 1569 if (limit == NULL) { 1570 DYN_BUCKET_UNLOCK(bucket); 1571 return (NULL); 1572 } 1573 1574 s = dyn_alloc_ipv4_state(pkt, kidx, O_LIMIT_PARENT); 1575 if (s == NULL) { 1576 DYN_BUCKET_UNLOCK(bucket); 1577 uma_zfree(V_dyn_parent_zone, limit); 1578 return (NULL); 1579 } 1580 1581 s->limit = limit; 1582 CK_SLIST_INSERT_HEAD(&V_dyn_ipv4_parent[bucket], s, entry); 1583 DYN_COUNT_INC(dyn_parent_count); 1584 DYN_BUCKET_VERSION_BUMP(bucket, ipv4_parent_add); 1585 DYNSTATE_CRITICAL_ENTER(); 1586 DYNSTATE_PROTECT(s); 1587 DYN_BUCKET_UNLOCK(bucket); 1588 return (s); 1589} 1590 1591static int 1592dyn_add_ipv4_state(void *parent, uint32_t ruleid, uint16_t rulenum, 1593 const struct ipfw_flow_id *pkt, const void *ulp, int pktlen, 1594 uint32_t hashval, struct ipfw_dyn_info *info, uint16_t fibnum, 1595 uint16_t kidx, uint8_t type) 1596{ 1597 struct dyn_ipv4_state *s; 1598 void *data; 1599 uint32_t bucket; 1600 1601 bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets); 1602 DYN_BUCKET_LOCK(bucket); 1603 if (info->direction == MATCH_UNKNOWN || 1604 info->kidx != kidx || 1605 info->hashval != hashval || 1606 info->version != DYN_BUCKET_VERSION(bucket, ipv4_add)) { 1607 /* 1608 * Bucket version has been changed since last lookup, 1609 * do lookup again to be sure that state does not exist. 1610 */ 1611 if (dyn_lookup_ipv4_state_locked(pkt, ulp, pktlen, 1612 bucket, kidx) != 0) { 1613 DYN_BUCKET_UNLOCK(bucket); 1614 return (EEXIST); 1615 } 1616 } 1617 1618 data = dyn_alloc_dyndata(parent, ruleid, rulenum, pkt, ulp, 1619 pktlen, hashval, fibnum); 1620 if (data == NULL) { 1621 DYN_BUCKET_UNLOCK(bucket); 1622 return (ENOMEM); 1623 } 1624 1625 s = dyn_alloc_ipv4_state(pkt, kidx, type); 1626 if (s == NULL) { 1627 DYN_BUCKET_UNLOCK(bucket); 1628 uma_zfree(V_dyn_data_zone, data); 1629 return (ENOMEM); 1630 } 1631 1632 s->data = data; 1633 CK_SLIST_INSERT_HEAD(&V_dyn_ipv4[bucket], s, entry); 1634 DYN_COUNT_INC(dyn_count); 1635 DYN_BUCKET_VERSION_BUMP(bucket, ipv4_add); 1636 DYN_BUCKET_UNLOCK(bucket); 1637 return (0); 1638} 1639 1640#ifdef INET6 1641static struct dyn_ipv6_state * 1642dyn_alloc_ipv6_state(const struct ipfw_flow_id *pkt, uint32_t zoneid, 1643 uint16_t kidx, uint8_t type) 1644{ 1645 struct dyn_ipv6_state *s; 1646 1647 s = uma_zalloc(V_dyn_ipv6_zone, M_NOWAIT | M_ZERO); 1648 if (s == NULL) 1649 return (NULL); 1650 1651 s->type = type; 1652 s->kidx = kidx; 1653 s->zoneid = zoneid; 1654 s->proto = pkt->proto; 1655 s->sport = pkt->src_port; 1656 s->dport = pkt->dst_port; 1657 s->src = pkt->src_ip6; 1658 s->dst = pkt->dst_ip6; 1659 return (s); 1660} 1661 1662/* 1663 * Add IPv6 parent state. 1664 * Returns pointer to parent state. When it is not NULL we are in 1665 * critical section and pointer protected by hazard pointer. 1666 * When some error occurs, it return NULL and exit from critical section 1667 * is not needed. 1668 */ 1669static struct dyn_ipv6_state * 1670dyn_add_ipv6_parent(void *rule, uint32_t ruleid, uint16_t rulenum, 1671 const struct ipfw_flow_id *pkt, uint32_t zoneid, uint32_t hashval, 1672 uint32_t version, uint16_t kidx) 1673{ 1674 struct dyn_ipv6_state *s; 1675 struct dyn_parent *limit; 1676 uint32_t bucket; 1677 1678 bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets); 1679 DYN_BUCKET_LOCK(bucket); 1680 if (version != DYN_BUCKET_VERSION(bucket, ipv6_parent_add)) { 1681 /* 1682 * Bucket version has been changed since last lookup, 1683 * do lookup again to be sure that state does not exist. 1684 */ 1685 s = dyn_lookup_ipv6_parent_locked(pkt, zoneid, rule, ruleid, 1686 rulenum, bucket); 1687 if (s != NULL) { 1688 /* 1689 * Simultaneous thread has already created this 1690 * state. Just return it. 1691 */ 1692 DYNSTATE_CRITICAL_ENTER(); 1693 DYNSTATE_PROTECT(s); 1694 DYN_BUCKET_UNLOCK(bucket); 1695 return (s); 1696 } 1697 } 1698 1699 limit = dyn_alloc_parent(rule, ruleid, rulenum, hashval); 1700 if (limit == NULL) { 1701 DYN_BUCKET_UNLOCK(bucket); 1702 return (NULL); 1703 } 1704 1705 s = dyn_alloc_ipv6_state(pkt, zoneid, kidx, O_LIMIT_PARENT); 1706 if (s == NULL) { 1707 DYN_BUCKET_UNLOCK(bucket); 1708 uma_zfree(V_dyn_parent_zone, limit); 1709 return (NULL); 1710 } 1711 1712 s->limit = limit; 1713 CK_SLIST_INSERT_HEAD(&V_dyn_ipv6_parent[bucket], s, entry); 1714 DYN_COUNT_INC(dyn_parent_count); 1715 DYN_BUCKET_VERSION_BUMP(bucket, ipv6_parent_add); 1716 DYNSTATE_CRITICAL_ENTER(); 1717 DYNSTATE_PROTECT(s); 1718 DYN_BUCKET_UNLOCK(bucket); 1719 return (s); 1720} 1721 1722static int 1723dyn_add_ipv6_state(void *parent, uint32_t ruleid, uint16_t rulenum, 1724 const struct ipfw_flow_id *pkt, uint32_t zoneid, const void *ulp, 1725 int pktlen, uint32_t hashval, struct ipfw_dyn_info *info, 1726 uint16_t fibnum, uint16_t kidx, uint8_t type) 1727{ 1728 struct dyn_ipv6_state *s; 1729 struct dyn_data *data; 1730 uint32_t bucket; 1731 1732 bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets); 1733 DYN_BUCKET_LOCK(bucket); 1734 if (info->direction == MATCH_UNKNOWN || 1735 info->kidx != kidx || 1736 info->hashval != hashval || 1737 info->version != DYN_BUCKET_VERSION(bucket, ipv6_add)) { 1738 /* 1739 * Bucket version has been changed since last lookup, 1740 * do lookup again to be sure that state does not exist. 1741 */ 1742 if (dyn_lookup_ipv6_state_locked(pkt, zoneid, ulp, pktlen, 1743 bucket, kidx) != 0) { 1744 DYN_BUCKET_UNLOCK(bucket); 1745 return (EEXIST); 1746 } 1747 } 1748 1749 data = dyn_alloc_dyndata(parent, ruleid, rulenum, pkt, ulp, 1750 pktlen, hashval, fibnum); 1751 if (data == NULL) { 1752 DYN_BUCKET_UNLOCK(bucket); 1753 return (ENOMEM); 1754 } 1755 1756 s = dyn_alloc_ipv6_state(pkt, zoneid, kidx, type); 1757 if (s == NULL) { 1758 DYN_BUCKET_UNLOCK(bucket); 1759 uma_zfree(V_dyn_data_zone, data); 1760 return (ENOMEM); 1761 } 1762 1763 s->data = data; 1764 CK_SLIST_INSERT_HEAD(&V_dyn_ipv6[bucket], s, entry); 1765 DYN_COUNT_INC(dyn_count); 1766 DYN_BUCKET_VERSION_BUMP(bucket, ipv6_add); 1767 DYN_BUCKET_UNLOCK(bucket); 1768 return (0); 1769} 1770#endif /* INET6 */ 1771 1772static void * 1773dyn_get_parent_state(const struct ipfw_flow_id *pkt, uint32_t zoneid, 1774 struct ip_fw *rule, uint32_t hashval, uint32_t limit, uint16_t kidx) 1775{ 1776 char sbuf[24]; 1777 struct dyn_parent *p; 1778 void *ret; 1779 uint32_t bucket, version; 1780 1781 p = NULL; 1782 ret = NULL; 1783 bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets); 1784 DYNSTATE_CRITICAL_ENTER(); 1785 if (IS_IP4_FLOW_ID(pkt)) { 1786 struct dyn_ipv4_state *s; 1787 1788 version = DYN_BUCKET_VERSION(bucket, ipv4_parent_add); 1789 s = dyn_lookup_ipv4_parent(pkt, rule, rule->id, 1790 rule->rulenum, bucket); 1791 if (s == NULL) { 1792 /* 1793 * Exit from critical section because dyn_add_parent() 1794 * will acquire bucket lock. 1795 */ 1796 DYNSTATE_CRITICAL_EXIT(); 1797 1798 s = dyn_add_ipv4_parent(rule, rule->id, 1799 rule->rulenum, pkt, hashval, version, kidx); 1800 if (s == NULL) 1801 return (NULL); 1802 /* Now we are in critical section again. */ 1803 } 1804 ret = s; 1805 p = s->limit; 1806 } 1807#ifdef INET6 1808 else if (IS_IP6_FLOW_ID(pkt)) { 1809 struct dyn_ipv6_state *s; 1810 1811 version = DYN_BUCKET_VERSION(bucket, ipv6_parent_add); 1812 s = dyn_lookup_ipv6_parent(pkt, zoneid, rule, rule->id, 1813 rule->rulenum, bucket); 1814 if (s == NULL) { 1815 /* 1816 * Exit from critical section because dyn_add_parent() 1817 * can acquire bucket mutex. 1818 */ 1819 DYNSTATE_CRITICAL_EXIT(); 1820 1821 s = dyn_add_ipv6_parent(rule, rule->id, 1822 rule->rulenum, pkt, zoneid, hashval, version, 1823 kidx); 1824 if (s == NULL) 1825 return (NULL); 1826 /* Now we are in critical section again. */ 1827 } 1828 ret = s; 1829 p = s->limit; 1830 } 1831#endif 1832 else { 1833 DYNSTATE_CRITICAL_EXIT(); 1834 return (NULL); 1835 } 1836 1837 /* Check the limit */ 1838 if (DPARENT_COUNT(p) >= limit) { 1839 DYNSTATE_CRITICAL_EXIT(); 1840 if (V_fw_verbose && last_log != time_uptime) { 1841 last_log = time_uptime; 1842 snprintf(sbuf, sizeof(sbuf), "%u drop session", 1843 rule->rulenum); 1844 print_dyn_rule_flags(pkt, O_LIMIT, 1845 LOG_SECURITY | LOG_DEBUG, sbuf, 1846 "too many entries"); 1847 } 1848 return (NULL); 1849 } 1850 1851 /* Take new session into account. */ 1852 DPARENT_COUNT_INC(p); 1853 /* 1854 * We must exit from critical section because the following code 1855 * can acquire bucket mutex. 1856 * We rely on the the 'count' field. The state will not expire 1857 * until it has some child states, i.e. 'count' field is not zero. 1858 * Return state pointer, it will be used by child states as parent. 1859 */ 1860 DYNSTATE_CRITICAL_EXIT(); 1861 return (ret); 1862} 1863 1864static int 1865dyn_install_state(const struct ipfw_flow_id *pkt, uint32_t zoneid, 1866 uint16_t fibnum, const void *ulp, int pktlen, struct ip_fw *rule, 1867 struct ipfw_dyn_info *info, uint32_t limit, uint16_t limit_mask, 1868 uint16_t kidx, uint8_t type) 1869{ 1870 struct ipfw_flow_id id; 1871 uint32_t hashval, parent_hashval, ruleid, rulenum; 1872 int ret; 1873 1874 MPASS(type == O_LIMIT || type == O_KEEP_STATE); 1875 1876 ruleid = rule->id; 1877 rulenum = rule->rulenum; 1878 if (type == O_LIMIT) { 1879 /* Create masked flow id and calculate bucket */ 1880 id.addr_type = pkt->addr_type; 1881 id.proto = pkt->proto; 1882 id.fib = fibnum; /* unused */ 1883 id.src_port = (limit_mask & DYN_SRC_PORT) ? 1884 pkt->src_port: 0; 1885 id.dst_port = (limit_mask & DYN_DST_PORT) ? 1886 pkt->dst_port: 0; 1887 if (IS_IP4_FLOW_ID(pkt)) { 1888 id.src_ip = (limit_mask & DYN_SRC_ADDR) ? 1889 pkt->src_ip: 0; 1890 id.dst_ip = (limit_mask & DYN_DST_ADDR) ? 1891 pkt->dst_ip: 0; 1892 } 1893#ifdef INET6 1894 else if (IS_IP6_FLOW_ID(pkt)) { 1895 if (limit_mask & DYN_SRC_ADDR) 1896 id.src_ip6 = pkt->src_ip6; 1897 else 1898 memset(&id.src_ip6, 0, sizeof(id.src_ip6)); 1899 if (limit_mask & DYN_DST_ADDR) 1900 id.dst_ip6 = pkt->dst_ip6; 1901 else 1902 memset(&id.dst_ip6, 0, sizeof(id.dst_ip6)); 1903 } 1904#endif 1905 else 1906 return (EAFNOSUPPORT); 1907 1908 parent_hashval = hash_parent(&id, rule); 1909 rule = dyn_get_parent_state(&id, zoneid, rule, parent_hashval, 1910 limit, kidx); 1911 if (rule == NULL) { 1912#if 0 1913 if (V_fw_verbose && last_log != time_uptime) { 1914 last_log = time_uptime; 1915 snprintf(sbuf, sizeof(sbuf), 1916 "%u drop session", rule->rulenum); 1917 print_dyn_rule_flags(pkt, O_LIMIT, 1918 LOG_SECURITY | LOG_DEBUG, sbuf, 1919 "too many entries"); 1920 } 1921#endif 1922 return (EACCES); 1923 } 1924 /* 1925 * Limit is not reached, create new state. 1926 * Now rule points to parent state. 1927 */ 1928 } 1929 1930 hashval = hash_packet(pkt); 1931 if (IS_IP4_FLOW_ID(pkt)) 1932 ret = dyn_add_ipv4_state(rule, ruleid, rulenum, pkt, 1933 ulp, pktlen, hashval, info, fibnum, kidx, type); 1934#ifdef INET6 1935 else if (IS_IP6_FLOW_ID(pkt)) 1936 ret = dyn_add_ipv6_state(rule, ruleid, rulenum, pkt, 1937 zoneid, ulp, pktlen, hashval, info, fibnum, kidx, type); 1938#endif /* INET6 */ 1939 else 1940 ret = EAFNOSUPPORT; 1941 1942 if (type == O_LIMIT) { 1943 if (ret != 0) { 1944 /* 1945 * We failed to create child state for O_LIMIT 1946 * opcode. Since we already counted it in the parent, 1947 * we must revert counter back. The 'rule' points to 1948 * parent state, use it to get dyn_parent. 1949 * 1950 * XXXAE: it should be safe to use 'rule' pointer 1951 * without extra lookup, parent state is referenced 1952 * and should not be freed. 1953 */ 1954 if (IS_IP4_FLOW_ID(&id)) 1955 DPARENT_COUNT_DEC( 1956 ((struct dyn_ipv4_state *)rule)->limit); 1957#ifdef INET6 1958 else if (IS_IP6_FLOW_ID(&id)) 1959 DPARENT_COUNT_DEC( 1960 ((struct dyn_ipv6_state *)rule)->limit); 1961#endif 1962 } 1963 } 1964 /* 1965 * EEXIST means that simultaneous thread has created this 1966 * state. Consider this as success. 1967 * 1968 * XXXAE: should we invalidate 'info' content here? 1969 */ 1970 if (ret == EEXIST) 1971 return (0); 1972 return (ret); 1973} 1974 1975/* 1976 * Install dynamic state. 1977 * chain - ipfw's instance; 1978 * rule - the parent rule that installs the state; 1979 * cmd - opcode that installs the state; 1980 * args - ipfw arguments; 1981 * ulp - upper level protocol header; 1982 * pktlen - packet length; 1983 * info - dynamic state lookup info; 1984 * tablearg - tablearg id. 1985 * 1986 * Returns non-zero value (failure) if state is not installed because 1987 * of errors or because session limitations are enforced. 1988 */ 1989int 1990ipfw_dyn_install_state(struct ip_fw_chain *chain, struct ip_fw *rule, 1991 const ipfw_insn_limit *cmd, const struct ip_fw_args *args, 1992 const void *ulp, int pktlen, struct ipfw_dyn_info *info, 1993 uint32_t tablearg) 1994{ 1995 uint32_t limit; 1996 uint16_t limit_mask; 1997 1998 if (cmd->o.opcode == O_LIMIT) { 1999 limit = IP_FW_ARG_TABLEARG(chain, cmd->conn_limit, limit); 2000 limit_mask = cmd->limit_mask; 2001 } else { 2002 limit = 0; 2003 limit_mask = 0; 2004 } 2005 return (dyn_install_state(&args->f_id, 2006#ifdef INET6 2007 IS_IP6_FLOW_ID(&args->f_id) ? dyn_getscopeid(args): 2008#endif 2009 0, M_GETFIB(args->m), ulp, pktlen, rule, info, limit, 2010 limit_mask, cmd->o.arg1, cmd->o.opcode)); 2011} 2012 2013/* 2014 * Free safe to remove state entries from expired lists. 2015 */ 2016static void 2017dyn_free_states(struct ip_fw_chain *chain) 2018{ 2019 struct dyn_ipv4_state *s4, *s4n; 2020#ifdef INET6 2021 struct dyn_ipv6_state *s6, *s6n; 2022#endif 2023 int cached_count, i; 2024 2025 /* 2026 * We keep pointers to objects that are in use on each CPU 2027 * in the per-cpu dyn_hp pointer. When object is going to be 2028 * removed, first of it is unlinked from the corresponding 2029 * list. This leads to changing of dyn_bucket_xxx_delver version. 2030 * Unlinked objects is placed into corresponding dyn_expired_xxx 2031 * list. Reader that is going to dereference object pointer checks 2032 * dyn_bucket_xxx_delver version before and after storing pointer 2033 * into dyn_hp. If version is the same, the object is protected 2034 * from freeing and it is safe to dereference. Othervise reader 2035 * tries to iterate list again from the beginning, but this object 2036 * now unlinked and thus will not be accessible. 2037 * 2038 * Copy dyn_hp pointers for each CPU into dyn_hp_cache array. 2039 * It does not matter that some pointer can be changed in 2040 * time while we are copying. We need to check, that objects 2041 * removed in the previous pass are not in use. And if dyn_hp 2042 * pointer does not contain it in the time when we are copying, 2043 * it will not appear there, because it is already unlinked. 2044 * And for new pointers we will not free objects that will be 2045 * unlinked in this pass. 2046 */ 2047 cached_count = 0; 2048 CPU_FOREACH(i) { 2049 dyn_hp_cache[cached_count] = DYNSTATE_GET(i); 2050 if (dyn_hp_cache[cached_count] != NULL) 2051 cached_count++; 2052 } 2053 2054 /* 2055 * Free expired states that are safe to free. 2056 * Check each entry from previous pass in the dyn_expired_xxx 2057 * list, if pointer to the object is in the dyn_hp_cache array, 2058 * keep it until next pass. Otherwise it is safe to free the 2059 * object. 2060 * 2061 * XXXAE: optimize this to use SLIST_REMOVE_AFTER. 2062 */ 2063#define DYN_FREE_STATES(s, next, name) do { \ 2064 s = SLIST_FIRST(&V_dyn_expired_ ## name); \ 2065 while (s != NULL) { \ 2066 next = SLIST_NEXT(s, expired); \ 2067 for (i = 0; i < cached_count; i++) \ 2068 if (dyn_hp_cache[i] == s) \ 2069 break; \ 2070 if (i == cached_count) { \ 2071 if (s->type == O_LIMIT_PARENT && \ 2072 s->limit->count != 0) { \ 2073 s = next; \ 2074 continue; \ 2075 } \ 2076 SLIST_REMOVE(&V_dyn_expired_ ## name, \ 2077 s, dyn_ ## name ## _state, expired); \ 2078 if (s->type == O_LIMIT_PARENT) \ 2079 uma_zfree(V_dyn_parent_zone, s->limit); \ 2080 else \ 2081 uma_zfree(V_dyn_data_zone, s->data); \ 2082 uma_zfree(V_dyn_ ## name ## _zone, s); \ 2083 } \ 2084 s = next; \ 2085 } \ 2086} while (0) 2087 2088 /* 2089 * Protect access to expired lists with DYN_EXPIRED_LOCK. 2090 * Userland can invoke ipfw_expire_dyn_states() to delete 2091 * specific states, this will lead to modification of expired 2092 * lists. 2093 * 2094 * XXXAE: do we need DYN_EXPIRED_LOCK? We can just use 2095 * IPFW_UH_WLOCK to protect access to these lists. 2096 */ 2097 DYN_EXPIRED_LOCK(); 2098 DYN_FREE_STATES(s4, s4n, ipv4); 2099#ifdef INET6 2100 DYN_FREE_STATES(s6, s6n, ipv6); 2101#endif 2102 DYN_EXPIRED_UNLOCK(); 2103#undef DYN_FREE_STATES 2104} 2105 2106/* 2107 * Returns: 2108 * 0 when state is not matched by specified range; 2109 * 1 when state is matched by specified range; 2110 * 2 when state is matched by specified range and requested deletion of 2111 * dynamic states. 2112 */ 2113static int 2114dyn_match_range(uint16_t rulenum, uint8_t set, const ipfw_range_tlv *rt) 2115{ 2116 2117 MPASS(rt != NULL); 2118 /* flush all states */ 2119 if (rt->flags & IPFW_RCFLAG_ALL) { 2120 if (rt->flags & IPFW_RCFLAG_DYNAMIC) 2121 return (2); /* forced */ 2122 return (1); 2123 } 2124 if ((rt->flags & IPFW_RCFLAG_SET) != 0 && set != rt->set) 2125 return (0); 2126 if ((rt->flags & IPFW_RCFLAG_RANGE) != 0 && 2127 (rulenum < rt->start_rule || rulenum > rt->end_rule)) 2128 return (0); 2129 if (rt->flags & IPFW_RCFLAG_DYNAMIC) 2130 return (2); 2131 return (1); 2132} 2133 2134static void 2135dyn_acquire_rule(struct ip_fw_chain *ch, struct dyn_data *data, 2136 struct ip_fw *rule, uint16_t kidx) 2137{ 2138 struct dyn_state_obj *obj; 2139 2140 /* 2141 * Do not acquire reference twice. 2142 * This can happen when rule deletion executed for 2143 * the same range, but different ruleset id. 2144 */ 2145 if (data->flags & DYN_REFERENCED) 2146 return; 2147 2148 IPFW_UH_WLOCK_ASSERT(ch); 2149 MPASS(kidx != 0); 2150 2151 data->flags |= DYN_REFERENCED; 2152 /* Reference the named object */ 2153 obj = SRV_OBJECT(ch, kidx); 2154 obj->no.refcnt++; 2155 MPASS(obj->no.etlv == IPFW_TLV_STATE_NAME); 2156 2157 /* Reference the parent rule */ 2158 rule->refcnt++; 2159} 2160 2161static void 2162dyn_release_rule(struct ip_fw_chain *ch, struct dyn_data *data, 2163 struct ip_fw *rule, uint16_t kidx) 2164{ 2165 struct dyn_state_obj *obj; 2166 2167 IPFW_UH_WLOCK_ASSERT(ch); 2168 MPASS(kidx != 0); 2169 2170 obj = SRV_OBJECT(ch, kidx); 2171 if (obj->no.refcnt == 1) 2172 dyn_destroy(ch, &obj->no); 2173 else 2174 obj->no.refcnt--; 2175 2176 if (--rule->refcnt == 1) 2177 ipfw_free_rule(rule); 2178} 2179 2180/* 2181 * We do not keep O_LIMIT_PARENT states when V_dyn_keep_states is enabled. 2182 * O_LIMIT state is created when new connection is going to be established 2183 * and there is no matching state. So, since the old parent rule was deleted 2184 * we can't create new states with old parent, and thus we can not account 2185 * new connections with already established connections, and can not do 2186 * proper limiting. 2187 */ 2188static int 2189dyn_match_ipv4_state(struct ip_fw_chain *ch, struct dyn_ipv4_state *s, 2190 const ipfw_range_tlv *rt) 2191{ 2192 struct ip_fw *rule; 2193 int ret; 2194 2195 if (s->type == O_LIMIT_PARENT) { 2196 rule = s->limit->parent; 2197 return (dyn_match_range(s->limit->rulenum, rule->set, rt)); 2198 } 2199 2200 rule = s->data->parent; 2201 if (s->type == O_LIMIT) 2202 rule = ((struct dyn_ipv4_state *)rule)->limit->parent; 2203 2204 ret = dyn_match_range(s->data->rulenum, rule->set, rt); 2205 if (ret == 0 || V_dyn_keep_states == 0 || ret > 1) 2206 return (ret); 2207 2208 dyn_acquire_rule(ch, s->data, rule, s->kidx); 2209 return (0); 2210} 2211 2212#ifdef INET6 2213static int 2214dyn_match_ipv6_state(struct ip_fw_chain *ch, struct dyn_ipv6_state *s, 2215 const ipfw_range_tlv *rt) 2216{ 2217 struct ip_fw *rule; 2218 int ret; 2219 2220 if (s->type == O_LIMIT_PARENT) { 2221 rule = s->limit->parent; 2222 return (dyn_match_range(s->limit->rulenum, rule->set, rt)); 2223 } 2224 2225 rule = s->data->parent; 2226 if (s->type == O_LIMIT) 2227 rule = ((struct dyn_ipv6_state *)rule)->limit->parent; 2228 2229 ret = dyn_match_range(s->data->rulenum, rule->set, rt); 2230 if (ret == 0 || V_dyn_keep_states == 0 || ret > 1) 2231 return (ret); 2232 2233 dyn_acquire_rule(ch, s->data, rule, s->kidx); 2234 return (0); 2235} 2236#endif 2237 2238/* 2239 * Unlink expired entries from states lists. 2240 * @rt can be used to specify the range of states for deletion. 2241 */ 2242static void 2243dyn_expire_states(struct ip_fw_chain *ch, ipfw_range_tlv *rt) 2244{ 2245 struct dyn_ipv4_slist expired_ipv4; 2246#ifdef INET6 2247 struct dyn_ipv6_slist expired_ipv6; 2248 struct dyn_ipv6_state *s6, *s6n, *s6p; 2249#endif 2250 struct dyn_ipv4_state *s4, *s4n, *s4p; 2251 void *rule; 2252 int bucket, removed, length, max_length; 2253 2254 IPFW_UH_WLOCK_ASSERT(ch); 2255 2256 /* 2257 * Unlink expired states from each bucket. 2258 * With acquired bucket lock iterate entries of each lists: 2259 * ipv4, ipv4_parent, ipv6, and ipv6_parent. Check expired time 2260 * and unlink entry from the list, link entry into temporary 2261 * expired_xxx lists then bump "del" bucket version. 2262 * 2263 * When an entry is removed, corresponding states counter is 2264 * decremented. If entry has O_LIMIT type, parent's reference 2265 * counter is decremented. 2266 * 2267 * NOTE: this function can be called from userspace context 2268 * when user deletes rules. In this case all matched states 2269 * will be forcedly unlinked. O_LIMIT_PARENT states will be kept 2270 * in the expired lists until reference counter become zero. 2271 */ 2272#define DYN_UNLINK_STATES(s, prev, next, exp, af, name, extra) do { \ 2273 length = 0; \ 2274 removed = 0; \ 2275 prev = NULL; \ 2276 s = CK_SLIST_FIRST(&V_dyn_ ## name [bucket]); \ 2277 while (s != NULL) { \ 2278 next = CK_SLIST_NEXT(s, entry); \ 2279 if ((TIME_LEQ((s)->exp, time_uptime) && extra) || \ 2280 (rt != NULL && \ 2281 dyn_match_ ## af ## _state(ch, s, rt))) { \ 2282 if (prev != NULL) \ 2283 CK_SLIST_REMOVE_AFTER(prev, entry); \ 2284 else \ 2285 CK_SLIST_REMOVE_HEAD( \ 2286 &V_dyn_ ## name [bucket], entry); \ 2287 removed++; \ 2288 SLIST_INSERT_HEAD(&expired_ ## af, s, expired); \ 2289 if (s->type == O_LIMIT_PARENT) \ 2290 DYN_COUNT_DEC(dyn_parent_count); \ 2291 else { \ 2292 DYN_COUNT_DEC(dyn_count); \ 2293 if (s->data->flags & DYN_REFERENCED) { \ 2294 rule = s->data->parent; \ 2295 if (s->type == O_LIMIT) \ 2296 rule = ((__typeof(s)) \ 2297 rule)->limit->parent;\ 2298 dyn_release_rule(ch, s->data, \ 2299 rule, s->kidx); \ 2300 } \ 2301 if (s->type == O_LIMIT) { \ 2302 s = s->data->parent; \ 2303 DPARENT_COUNT_DEC(s->limit); \ 2304 } \ 2305 } \ 2306 } else { \ 2307 prev = s; \ 2308 length++; \ 2309 } \ 2310 s = next; \ 2311 } \ 2312 if (removed != 0) \ 2313 DYN_BUCKET_VERSION_BUMP(bucket, name ## _del); \ 2314 if (length > max_length) \ 2315 max_length = length; \ 2316} while (0) 2317 2318 SLIST_INIT(&expired_ipv4); 2319#ifdef INET6 2320 SLIST_INIT(&expired_ipv6); 2321#endif 2322 max_length = 0; 2323 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { 2324 DYN_BUCKET_LOCK(bucket); 2325 DYN_UNLINK_STATES(s4, s4p, s4n, data->expire, ipv4, ipv4, 1); 2326 DYN_UNLINK_STATES(s4, s4p, s4n, limit->expire, ipv4, 2327 ipv4_parent, (s4->limit->count == 0)); 2328#ifdef INET6 2329 DYN_UNLINK_STATES(s6, s6p, s6n, data->expire, ipv6, ipv6, 1); 2330 DYN_UNLINK_STATES(s6, s6p, s6n, limit->expire, ipv6, 2331 ipv6_parent, (s6->limit->count == 0)); 2332#endif 2333 DYN_BUCKET_UNLOCK(bucket); 2334 } 2335 /* Update curr_max_length for statistics. */ 2336 V_curr_max_length = max_length; 2337 /* 2338 * Concatenate temporary lists with global expired lists. 2339 */ 2340 DYN_EXPIRED_LOCK(); 2341 SLIST_CONCAT(&V_dyn_expired_ipv4, &expired_ipv4, 2342 dyn_ipv4_state, expired); 2343#ifdef INET6 2344 SLIST_CONCAT(&V_dyn_expired_ipv6, &expired_ipv6, 2345 dyn_ipv6_state, expired); 2346#endif 2347 DYN_EXPIRED_UNLOCK(); 2348#undef DYN_UNLINK_STATES 2349#undef DYN_UNREF_STATES 2350} 2351 2352static struct mbuf * 2353dyn_mgethdr(int len, uint16_t fibnum) 2354{ 2355 struct mbuf *m; 2356 2357 m = m_gethdr(M_NOWAIT, MT_DATA); 2358 if (m == NULL) 2359 return (NULL); 2360#ifdef MAC 2361 mac_netinet_firewall_send(m); 2362#endif 2363 M_SETFIB(m, fibnum); 2364 m->m_data += max_linkhdr; 2365 m->m_flags |= M_SKIP_FIREWALL; 2366 m->m_len = m->m_pkthdr.len = len; 2367 bzero(m->m_data, len); 2368 return (m); 2369} 2370 2371static void 2372dyn_make_keepalive_ipv4(struct mbuf *m, in_addr_t src, in_addr_t dst, 2373 uint32_t seq, uint32_t ack, uint16_t sport, uint16_t dport) 2374{ 2375 struct tcphdr *tcp; 2376 struct ip *ip; 2377 2378 ip = mtod(m, struct ip *); 2379 ip->ip_v = 4; 2380 ip->ip_hl = sizeof(*ip) >> 2; 2381 ip->ip_tos = IPTOS_LOWDELAY; 2382 ip->ip_len = htons(m->m_len); 2383 ip->ip_off |= htons(IP_DF); 2384 ip->ip_ttl = V_ip_defttl; 2385 ip->ip_p = IPPROTO_TCP; 2386 ip->ip_src.s_addr = htonl(src); 2387 ip->ip_dst.s_addr = htonl(dst); 2388 2389 tcp = mtodo(m, sizeof(struct ip)); 2390 tcp->th_sport = htons(sport); 2391 tcp->th_dport = htons(dport); 2392 tcp->th_off = sizeof(struct tcphdr) >> 2; 2393 tcp->th_seq = htonl(seq); 2394 tcp->th_ack = htonl(ack); 2395 tcp->th_flags = TH_ACK; 2396 tcp->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2397 htons(sizeof(struct tcphdr) + IPPROTO_TCP)); 2398 2399 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2400 m->m_pkthdr.csum_flags = CSUM_TCP; 2401} 2402 2403static void 2404dyn_enqueue_keepalive_ipv4(struct mbufq *q, const struct dyn_ipv4_state *s) 2405{ 2406 struct mbuf *m; 2407 2408 if ((s->data->state & ACK_FWD) == 0 && s->data->ack_fwd > 0) { 2409 m = dyn_mgethdr(sizeof(struct ip) + sizeof(struct tcphdr), 2410 s->data->fibnum); 2411 if (m != NULL) { 2412 dyn_make_keepalive_ipv4(m, s->dst, s->src, 2413 s->data->ack_fwd - 1, s->data->ack_rev, 2414 s->dport, s->sport); 2415 if (mbufq_enqueue(q, m)) { 2416 m_freem(m); 2417 log(LOG_DEBUG, "ipfw: limit for IPv4 " 2418 "keepalive queue is reached.\n"); 2419 return; 2420 } 2421 } 2422 } 2423 2424 if ((s->data->state & ACK_REV) == 0 && s->data->ack_rev > 0) { 2425 m = dyn_mgethdr(sizeof(struct ip) + sizeof(struct tcphdr), 2426 s->data->fibnum); 2427 if (m != NULL) { 2428 dyn_make_keepalive_ipv4(m, s->src, s->dst, 2429 s->data->ack_rev - 1, s->data->ack_fwd, 2430 s->sport, s->dport); 2431 if (mbufq_enqueue(q, m)) { 2432 m_freem(m); 2433 log(LOG_DEBUG, "ipfw: limit for IPv4 " 2434 "keepalive queue is reached.\n"); 2435 return; 2436 } 2437 } 2438 } 2439} 2440 2441/* 2442 * Prepare and send keep-alive packets. 2443 */ 2444static void 2445dyn_send_keepalive_ipv4(struct ip_fw_chain *chain) 2446{ 2447 struct mbufq q; 2448 struct mbuf *m; 2449 struct dyn_ipv4_state *s; 2450 uint32_t bucket; 2451 2452 mbufq_init(&q, INT_MAX); 2453 IPFW_UH_RLOCK(chain); 2454 /* 2455 * It is safe to not use hazard pointer and just do lockless 2456 * access to the lists, because states entries can not be deleted 2457 * while we hold IPFW_UH_RLOCK. 2458 */ 2459 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { 2460 CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) { 2461 /* 2462 * Only established TCP connections that will 2463 * become expired withing dyn_keepalive_interval. 2464 */ 2465 if (s->proto != IPPROTO_TCP || 2466 (s->data->state & BOTH_SYN) != BOTH_SYN || 2467 TIME_LEQ(time_uptime + V_dyn_keepalive_interval, 2468 s->data->expire)) 2469 continue; 2470 dyn_enqueue_keepalive_ipv4(&q, s); 2471 } 2472 } 2473 IPFW_UH_RUNLOCK(chain); 2474 while ((m = mbufq_dequeue(&q)) != NULL) 2475 ip_output(m, NULL, NULL, 0, NULL, NULL); 2476} 2477 2478#ifdef INET6 2479static void 2480dyn_make_keepalive_ipv6(struct mbuf *m, const struct in6_addr *src, 2481 const struct in6_addr *dst, uint32_t zoneid, uint32_t seq, uint32_t ack, 2482 uint16_t sport, uint16_t dport) 2483{ 2484 struct tcphdr *tcp; 2485 struct ip6_hdr *ip6; 2486 2487 ip6 = mtod(m, struct ip6_hdr *); 2488 ip6->ip6_vfc |= IPV6_VERSION; 2489 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 2490 ip6->ip6_nxt = IPPROTO_TCP; 2491 ip6->ip6_hlim = IPV6_DEFHLIM; 2492 ip6->ip6_src = *src; 2493 if (IN6_IS_ADDR_LINKLOCAL(src)) 2494 ip6->ip6_src.s6_addr16[1] = htons(zoneid & 0xffff); 2495 ip6->ip6_dst = *dst; 2496 if (IN6_IS_ADDR_LINKLOCAL(dst)) 2497 ip6->ip6_dst.s6_addr16[1] = htons(zoneid & 0xffff); 2498 2499 tcp = mtodo(m, sizeof(struct ip6_hdr)); 2500 tcp->th_sport = htons(sport); 2501 tcp->th_dport = htons(dport); 2502 tcp->th_off = sizeof(struct tcphdr) >> 2; 2503 tcp->th_seq = htonl(seq); 2504 tcp->th_ack = htonl(ack); 2505 tcp->th_flags = TH_ACK; 2506 tcp->th_sum = in6_cksum_pseudo(ip6, sizeof(struct tcphdr), 2507 IPPROTO_TCP, 0); 2508 2509 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2510 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 2511} 2512 2513static void 2514dyn_enqueue_keepalive_ipv6(struct mbufq *q, const struct dyn_ipv6_state *s) 2515{ 2516 struct mbuf *m; 2517 2518 if ((s->data->state & ACK_FWD) == 0 && s->data->ack_fwd > 0) { 2519 m = dyn_mgethdr(sizeof(struct ip6_hdr) + 2520 sizeof(struct tcphdr), s->data->fibnum); 2521 if (m != NULL) { 2522 dyn_make_keepalive_ipv6(m, &s->dst, &s->src, 2523 s->zoneid, s->data->ack_fwd - 1, s->data->ack_rev, 2524 s->dport, s->sport); 2525 if (mbufq_enqueue(q, m)) { 2526 m_freem(m); 2527 log(LOG_DEBUG, "ipfw: limit for IPv6 " 2528 "keepalive queue is reached.\n"); 2529 return; 2530 } 2531 } 2532 } 2533 2534 if ((s->data->state & ACK_REV) == 0 && s->data->ack_rev > 0) { 2535 m = dyn_mgethdr(sizeof(struct ip6_hdr) + 2536 sizeof(struct tcphdr), s->data->fibnum); 2537 if (m != NULL) { 2538 dyn_make_keepalive_ipv6(m, &s->src, &s->dst, 2539 s->zoneid, s->data->ack_rev - 1, s->data->ack_fwd, 2540 s->sport, s->dport); 2541 if (mbufq_enqueue(q, m)) { 2542 m_freem(m); 2543 log(LOG_DEBUG, "ipfw: limit for IPv6 " 2544 "keepalive queue is reached.\n"); 2545 return; 2546 } 2547 } 2548 } 2549} 2550 2551static void 2552dyn_send_keepalive_ipv6(struct ip_fw_chain *chain) 2553{ 2554 struct mbufq q; 2555 struct mbuf *m; 2556 struct dyn_ipv6_state *s; 2557 uint32_t bucket; 2558 2559 mbufq_init(&q, INT_MAX); 2560 IPFW_UH_RLOCK(chain); 2561 /* 2562 * It is safe to not use hazard pointer and just do lockless 2563 * access to the lists, because states entries can not be deleted 2564 * while we hold IPFW_UH_RLOCK. 2565 */ 2566 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { 2567 CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) { 2568 /* 2569 * Only established TCP connections that will 2570 * become expired withing dyn_keepalive_interval. 2571 */ 2572 if (s->proto != IPPROTO_TCP || 2573 (s->data->state & BOTH_SYN) != BOTH_SYN || 2574 TIME_LEQ(time_uptime + V_dyn_keepalive_interval, 2575 s->data->expire)) 2576 continue; 2577 dyn_enqueue_keepalive_ipv6(&q, s); 2578 } 2579 } 2580 IPFW_UH_RUNLOCK(chain); 2581 while ((m = mbufq_dequeue(&q)) != NULL) 2582 ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); 2583} 2584#endif /* INET6 */ 2585 2586static void 2587dyn_grow_hashtable(struct ip_fw_chain *chain, uint32_t new) 2588{ 2589#ifdef INET6 2590 struct dyn_ipv6ck_slist *ipv6, *ipv6_parent; 2591 uint32_t *ipv6_add, *ipv6_del, *ipv6_parent_add, *ipv6_parent_del; 2592 struct dyn_ipv6_state *s6; 2593#endif 2594 struct dyn_ipv4ck_slist *ipv4, *ipv4_parent; 2595 uint32_t *ipv4_add, *ipv4_del, *ipv4_parent_add, *ipv4_parent_del; 2596 struct dyn_ipv4_state *s4; 2597 struct mtx *bucket_lock; 2598 void *tmp; 2599 uint32_t bucket; 2600 2601 MPASS(powerof2(new)); 2602 DYN_DEBUG("grow hash size %u -> %u", V_curr_dyn_buckets, new); 2603 /* 2604 * Allocate and initialize new lists. 2605 * XXXAE: on memory pressure this can disable callout timer. 2606 */ 2607 bucket_lock = malloc(new * sizeof(struct mtx), M_IPFW, 2608 M_WAITOK | M_ZERO); 2609 ipv4 = malloc(new * sizeof(struct dyn_ipv4ck_slist), M_IPFW, 2610 M_WAITOK | M_ZERO); 2611 ipv4_parent = malloc(new * sizeof(struct dyn_ipv4ck_slist), M_IPFW, 2612 M_WAITOK | M_ZERO); 2613 ipv4_add = malloc(new * sizeof(uint32_t), M_IPFW, M_WAITOK | M_ZERO); 2614 ipv4_del = malloc(new * sizeof(uint32_t), M_IPFW, M_WAITOK | M_ZERO); 2615 ipv4_parent_add = malloc(new * sizeof(uint32_t), M_IPFW, 2616 M_WAITOK | M_ZERO); 2617 ipv4_parent_del = malloc(new * sizeof(uint32_t), M_IPFW, 2618 M_WAITOK | M_ZERO); 2619#ifdef INET6 2620 ipv6 = malloc(new * sizeof(struct dyn_ipv6ck_slist), M_IPFW, 2621 M_WAITOK | M_ZERO); 2622 ipv6_parent = malloc(new * sizeof(struct dyn_ipv6ck_slist), M_IPFW, 2623 M_WAITOK | M_ZERO); 2624 ipv6_add = malloc(new * sizeof(uint32_t), M_IPFW, M_WAITOK | M_ZERO); 2625 ipv6_del = malloc(new * sizeof(uint32_t), M_IPFW, M_WAITOK | M_ZERO); 2626 ipv6_parent_add = malloc(new * sizeof(uint32_t), M_IPFW, 2627 M_WAITOK | M_ZERO); 2628 ipv6_parent_del = malloc(new * sizeof(uint32_t), M_IPFW, 2629 M_WAITOK | M_ZERO); 2630#endif 2631 for (bucket = 0; bucket < new; bucket++) { 2632 DYN_BUCKET_LOCK_INIT(bucket_lock, bucket); 2633 CK_SLIST_INIT(&ipv4[bucket]); 2634 CK_SLIST_INIT(&ipv4_parent[bucket]); 2635#ifdef INET6 2636 CK_SLIST_INIT(&ipv6[bucket]); 2637 CK_SLIST_INIT(&ipv6_parent[bucket]); 2638#endif 2639 } 2640 2641#define DYN_RELINK_STATES(s, hval, i, head, ohead) do { \ 2642 while ((s = CK_SLIST_FIRST(&V_dyn_ ## ohead[i])) != NULL) { \ 2643 CK_SLIST_REMOVE_HEAD(&V_dyn_ ## ohead[i], entry); \ 2644 CK_SLIST_INSERT_HEAD(&head[DYN_BUCKET(s->hval, new)], \ 2645 s, entry); \ 2646 } \ 2647} while (0) 2648 /* 2649 * Prevent rules changing from userland. 2650 */ 2651 IPFW_UH_WLOCK(chain); 2652 /* 2653 * Hold traffic processing until we finish resize to 2654 * prevent access to states lists. 2655 */ 2656 IPFW_WLOCK(chain); 2657 /* Re-link all dynamic states */ 2658 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { 2659 DYN_RELINK_STATES(s4, data->hashval, bucket, ipv4, ipv4); 2660 DYN_RELINK_STATES(s4, limit->hashval, bucket, ipv4_parent, 2661 ipv4_parent); 2662#ifdef INET6 2663 DYN_RELINK_STATES(s6, data->hashval, bucket, ipv6, ipv6); 2664 DYN_RELINK_STATES(s6, limit->hashval, bucket, ipv6_parent, 2665 ipv6_parent); 2666#endif 2667 } 2668 2669#define DYN_SWAP_PTR(old, new, tmp) do { \ 2670 tmp = old; \ 2671 old = new; \ 2672 new = tmp; \ 2673} while (0) 2674 /* Swap pointers */ 2675 DYN_SWAP_PTR(V_dyn_bucket_lock, bucket_lock, tmp); 2676 DYN_SWAP_PTR(V_dyn_ipv4, ipv4, tmp); 2677 DYN_SWAP_PTR(V_dyn_ipv4_parent, ipv4_parent, tmp); 2678 DYN_SWAP_PTR(V_dyn_ipv4_add, ipv4_add, tmp); 2679 DYN_SWAP_PTR(V_dyn_ipv4_parent_add, ipv4_parent_add, tmp); 2680 DYN_SWAP_PTR(V_dyn_ipv4_del, ipv4_del, tmp); 2681 DYN_SWAP_PTR(V_dyn_ipv4_parent_del, ipv4_parent_del, tmp); 2682 2683#ifdef INET6 2684 DYN_SWAP_PTR(V_dyn_ipv6, ipv6, tmp); 2685 DYN_SWAP_PTR(V_dyn_ipv6_parent, ipv6_parent, tmp); 2686 DYN_SWAP_PTR(V_dyn_ipv6_add, ipv6_add, tmp); 2687 DYN_SWAP_PTR(V_dyn_ipv6_parent_add, ipv6_parent_add, tmp); 2688 DYN_SWAP_PTR(V_dyn_ipv6_del, ipv6_del, tmp); 2689 DYN_SWAP_PTR(V_dyn_ipv6_parent_del, ipv6_parent_del, tmp); 2690#endif 2691 bucket = V_curr_dyn_buckets; 2692 V_curr_dyn_buckets = new; 2693 2694 IPFW_WUNLOCK(chain); 2695 IPFW_UH_WUNLOCK(chain); 2696 2697 /* Release old resources */ 2698 while (bucket-- != 0) 2699 DYN_BUCKET_LOCK_DESTROY(bucket_lock, bucket); 2700 free(bucket_lock, M_IPFW); 2701 free(ipv4, M_IPFW); 2702 free(ipv4_parent, M_IPFW); 2703 free(ipv4_add, M_IPFW); 2704 free(ipv4_parent_add, M_IPFW); 2705 free(ipv4_del, M_IPFW); 2706 free(ipv4_parent_del, M_IPFW); 2707#ifdef INET6 2708 free(ipv6, M_IPFW); 2709 free(ipv6_parent, M_IPFW); 2710 free(ipv6_add, M_IPFW); 2711 free(ipv6_parent_add, M_IPFW); 2712 free(ipv6_del, M_IPFW); 2713 free(ipv6_parent_del, M_IPFW); 2714#endif 2715} 2716 2717/* 2718 * This function is used to perform various maintenance 2719 * on dynamic hash lists. Currently it is called every second. 2720 */ 2721static void 2722dyn_tick(void *vnetx) 2723{ 2724 uint32_t buckets; 2725 2726 CURVNET_SET((struct vnet *)vnetx); 2727 /* 2728 * First free states unlinked in previous passes. 2729 */ 2730 dyn_free_states(&V_layer3_chain); 2731 /* 2732 * Now unlink others expired states. 2733 * We use IPFW_UH_WLOCK to avoid concurrent call of 2734 * dyn_expire_states(). It is the only function that does 2735 * deletion of state entries from states lists. 2736 */ 2737 IPFW_UH_WLOCK(&V_layer3_chain); 2738 dyn_expire_states(&V_layer3_chain, NULL); 2739 IPFW_UH_WUNLOCK(&V_layer3_chain); 2740 /* 2741 * Send keepalives if they are enabled and the time has come. 2742 */ 2743 if (V_dyn_keepalive != 0 && 2744 V_dyn_keepalive_last + V_dyn_keepalive_period <= time_uptime) { 2745 V_dyn_keepalive_last = time_uptime; 2746 dyn_send_keepalive_ipv4(&V_layer3_chain); 2747#ifdef INET6 2748 dyn_send_keepalive_ipv6(&V_layer3_chain); 2749#endif 2750 } 2751 /* 2752 * Check if we need to resize the hash: 2753 * if current number of states exceeds number of buckets in hash, 2754 * and dyn_buckets_max permits to grow the number of buckets, then 2755 * do it. Grow hash size to the minimum power of 2 which is bigger 2756 * than current states count. 2757 */ 2758 if (V_curr_dyn_buckets < V_dyn_buckets_max && 2759 (V_curr_dyn_buckets < V_dyn_count / 2 || ( 2760 V_curr_dyn_buckets < V_dyn_count && V_curr_max_length > 8))) { 2761 buckets = 1 << fls(V_dyn_count); 2762 if (buckets > V_dyn_buckets_max) 2763 buckets = V_dyn_buckets_max; 2764 dyn_grow_hashtable(&V_layer3_chain, buckets); 2765 } 2766 2767 callout_reset_on(&V_dyn_timeout, hz, dyn_tick, vnetx, 0); 2768 CURVNET_RESTORE(); 2769} 2770 2771void 2772ipfw_expire_dyn_states(struct ip_fw_chain *chain, ipfw_range_tlv *rt) 2773{ 2774 /* 2775 * Do not perform any checks if we currently have no dynamic states 2776 */ 2777 if (V_dyn_count == 0) 2778 return; 2779 2780 IPFW_UH_WLOCK_ASSERT(chain); 2781 dyn_expire_states(chain, rt); 2782} 2783 2784/* 2785 * Pass through all states and reset eaction for orphaned rules. 2786 */ 2787void 2788ipfw_dyn_reset_eaction(struct ip_fw_chain *ch, uint16_t eaction_id, 2789 uint16_t default_id, uint16_t instance_id) 2790{ 2791#ifdef INET6 2792 struct dyn_ipv6_state *s6; 2793#endif 2794 struct dyn_ipv4_state *s4; 2795 struct ip_fw *rule; 2796 uint32_t bucket; 2797 2798#define DYN_RESET_EACTION(s, h, b) \ 2799 CK_SLIST_FOREACH(s, &V_dyn_ ## h[b], entry) { \ 2800 if ((s->data->flags & DYN_REFERENCED) == 0) \ 2801 continue; \ 2802 rule = s->data->parent; \ 2803 if (s->type == O_LIMIT) \ 2804 rule = ((__typeof(s))rule)->limit->parent; \ 2805 ipfw_reset_eaction(ch, rule, eaction_id, \ 2806 default_id, instance_id); \ 2807 } 2808 2809 IPFW_UH_WLOCK_ASSERT(ch); 2810 if (V_dyn_count == 0) 2811 return; 2812 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { 2813 DYN_RESET_EACTION(s4, ipv4, bucket); 2814#ifdef INET6 2815 DYN_RESET_EACTION(s6, ipv6, bucket); 2816#endif 2817 } 2818} 2819 2820/* 2821 * Returns size of dynamic states in legacy format 2822 */ 2823int 2824ipfw_dyn_len(void) 2825{ 2826 2827 return ((V_dyn_count + V_dyn_parent_count) * sizeof(ipfw_dyn_rule)); 2828} 2829 2830/* 2831 * Returns number of dynamic states. 2832 * Marks every named object index used by dynamic states with bit in @bmask. 2833 * Returns number of named objects accounted in bmask via @nocnt. 2834 * Used by dump format v1 (current). 2835 */ 2836uint32_t 2837ipfw_dyn_get_count(uint32_t *bmask, int *nocnt) 2838{ 2839#ifdef INET6 2840 struct dyn_ipv6_state *s6; 2841#endif 2842 struct dyn_ipv4_state *s4; 2843 uint32_t bucket; 2844 2845#define DYN_COUNT_OBJECTS(s, h, b) \ 2846 CK_SLIST_FOREACH(s, &V_dyn_ ## h[b], entry) { \ 2847 MPASS(s->kidx != 0); \ 2848 if (ipfw_mark_object_kidx(bmask, IPFW_TLV_STATE_NAME, \ 2849 s->kidx) != 0) \ 2850 (*nocnt)++; \ 2851 } 2852 2853 IPFW_UH_RLOCK_ASSERT(&V_layer3_chain); 2854 2855 /* No need to pass through all the buckets. */ 2856 *nocnt = 0; 2857 if (V_dyn_count + V_dyn_parent_count == 0) 2858 return (0); 2859 2860 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { 2861 DYN_COUNT_OBJECTS(s4, ipv4, bucket); 2862#ifdef INET6 2863 DYN_COUNT_OBJECTS(s6, ipv6, bucket); 2864#endif 2865 } 2866 2867 return (V_dyn_count + V_dyn_parent_count); 2868} 2869 2870/* 2871 * Check if rule contains at least one dynamic opcode. 2872 * 2873 * Returns 1 if such opcode is found, 0 otherwise. 2874 */ 2875int 2876ipfw_is_dyn_rule(struct ip_fw *rule) 2877{ 2878 int cmdlen, l; 2879 ipfw_insn *cmd; 2880 2881 l = rule->cmd_len; 2882 cmd = rule->cmd; 2883 cmdlen = 0; 2884 for ( ; l > 0 ; l -= cmdlen, cmd += cmdlen) { 2885 cmdlen = F_LEN(cmd); 2886 2887 switch (cmd->opcode) { 2888 case O_LIMIT: 2889 case O_KEEP_STATE: 2890 case O_PROBE_STATE: 2891 case O_CHECK_STATE: 2892 return (1); 2893 } 2894 } 2895 2896 return (0); 2897} 2898 2899static void 2900dyn_export_parent(const struct dyn_parent *p, uint16_t kidx, uint8_t set, 2901 ipfw_dyn_rule *dst) 2902{ 2903 2904 dst->dyn_type = O_LIMIT_PARENT; 2905 dst->kidx = kidx; 2906 dst->count = (uint16_t)DPARENT_COUNT(p); 2907 dst->expire = TIME_LEQ(p->expire, time_uptime) ? 0: 2908 p->expire - time_uptime; 2909 2910 /* 'rule' is used to pass up the rule number and set */ 2911 memcpy(&dst->rule, &p->rulenum, sizeof(p->rulenum)); 2912 2913 /* store set number into high word of dst->rule pointer. */ 2914 memcpy((char *)&dst->rule + sizeof(p->rulenum), &set, sizeof(set)); 2915 2916 /* unused fields */ 2917 dst->pcnt = 0; 2918 dst->bcnt = 0; 2919 dst->parent = NULL; 2920 dst->state = 0; 2921 dst->ack_fwd = 0; 2922 dst->ack_rev = 0; 2923 dst->bucket = p->hashval; 2924 /* 2925 * The legacy userland code will interpret a NULL here as a marker 2926 * for the last dynamic rule. 2927 */ 2928 dst->next = (ipfw_dyn_rule *)1; 2929} 2930 2931static void 2932dyn_export_data(const struct dyn_data *data, uint16_t kidx, uint8_t type, 2933 uint8_t set, ipfw_dyn_rule *dst) 2934{ 2935 2936 dst->dyn_type = type; 2937 dst->kidx = kidx; 2938 dst->pcnt = data->pcnt_fwd + data->pcnt_rev; 2939 dst->bcnt = data->bcnt_fwd + data->bcnt_rev; 2940 dst->expire = TIME_LEQ(data->expire, time_uptime) ? 0: 2941 data->expire - time_uptime; 2942 2943 /* 'rule' is used to pass up the rule number and set */ 2944 memcpy(&dst->rule, &data->rulenum, sizeof(data->rulenum)); 2945 2946 /* store set number into high word of dst->rule pointer. */ 2947 memcpy((char *)&dst->rule + sizeof(data->rulenum), &set, sizeof(set)); 2948 2949 dst->state = data->state; 2950 if (data->flags & DYN_REFERENCED) 2951 dst->state |= IPFW_DYN_ORPHANED; 2952 2953 /* unused fields */ 2954 dst->parent = NULL; 2955 dst->ack_fwd = data->ack_fwd; 2956 dst->ack_rev = data->ack_rev; 2957 dst->count = 0; 2958 dst->bucket = data->hashval; 2959 /* 2960 * The legacy userland code will interpret a NULL here as a marker 2961 * for the last dynamic rule. 2962 */ 2963 dst->next = (ipfw_dyn_rule *)1; 2964} 2965 2966static void 2967dyn_export_ipv4_state(const struct dyn_ipv4_state *s, ipfw_dyn_rule *dst) 2968{ 2969 struct ip_fw *rule; 2970 2971 switch (s->type) { 2972 case O_LIMIT_PARENT: 2973 rule = s->limit->parent; 2974 dyn_export_parent(s->limit, s->kidx, rule->set, dst); 2975 break; 2976 default: 2977 rule = s->data->parent; 2978 if (s->type == O_LIMIT) 2979 rule = ((struct dyn_ipv4_state *)rule)->limit->parent; 2980 dyn_export_data(s->data, s->kidx, s->type, rule->set, dst); 2981 } 2982 2983 dst->id.dst_ip = s->dst; 2984 dst->id.src_ip = s->src; 2985 dst->id.dst_port = s->dport; 2986 dst->id.src_port = s->sport; 2987 dst->id.fib = s->data->fibnum; 2988 dst->id.proto = s->proto; 2989 dst->id._flags = 0; 2990 dst->id.addr_type = 4; 2991 2992 memset(&dst->id.dst_ip6, 0, sizeof(dst->id.dst_ip6)); 2993 memset(&dst->id.src_ip6, 0, sizeof(dst->id.src_ip6)); 2994 dst->id.flow_id6 = dst->id.extra = 0; 2995} 2996 2997#ifdef INET6 2998static void 2999dyn_export_ipv6_state(const struct dyn_ipv6_state *s, ipfw_dyn_rule *dst) 3000{ 3001 struct ip_fw *rule; 3002 3003 switch (s->type) { 3004 case O_LIMIT_PARENT: 3005 rule = s->limit->parent; 3006 dyn_export_parent(s->limit, s->kidx, rule->set, dst); 3007 break; 3008 default: 3009 rule = s->data->parent; 3010 if (s->type == O_LIMIT) 3011 rule = ((struct dyn_ipv6_state *)rule)->limit->parent; 3012 dyn_export_data(s->data, s->kidx, s->type, rule->set, dst); 3013 } 3014 3015 dst->id.src_ip6 = s->src; 3016 dst->id.dst_ip6 = s->dst; 3017 dst->id.dst_port = s->dport; 3018 dst->id.src_port = s->sport; 3019 dst->id.fib = s->data->fibnum; 3020 dst->id.proto = s->proto; 3021 dst->id._flags = 0; 3022 dst->id.addr_type = 6; 3023 3024 dst->id.dst_ip = dst->id.src_ip = 0; 3025 dst->id.flow_id6 = dst->id.extra = 0; 3026} 3027#endif /* INET6 */ 3028 3029/* 3030 * Fills the buffer given by @sd with dynamic states. 3031 * Used by dump format v1 (current). 3032 * 3033 * Returns 0 on success. 3034 */ 3035int 3036ipfw_dump_states(struct ip_fw_chain *chain, struct sockopt_data *sd) 3037{ 3038#ifdef INET6 3039 struct dyn_ipv6_state *s6; 3040#endif 3041 struct dyn_ipv4_state *s4; 3042 ipfw_obj_dyntlv *dst, *last; 3043 ipfw_obj_ctlv *ctlv; 3044 uint32_t bucket; 3045 3046 if (V_dyn_count == 0) 3047 return (0); 3048 3049 /* 3050 * IPFW_UH_RLOCK garantees that another userland request 3051 * and callout thread will not delete entries from states 3052 * lists. 3053 */ 3054 IPFW_UH_RLOCK_ASSERT(chain); 3055 3056 ctlv = (ipfw_obj_ctlv *)ipfw_get_sopt_space(sd, sizeof(*ctlv)); 3057 if (ctlv == NULL) 3058 return (ENOMEM); 3059 ctlv->head.type = IPFW_TLV_DYNSTATE_LIST; 3060 ctlv->objsize = sizeof(ipfw_obj_dyntlv); 3061 last = NULL; 3062 3063#define DYN_EXPORT_STATES(s, af, h, b) \ 3064 CK_SLIST_FOREACH(s, &V_dyn_ ## h[b], entry) { \ 3065 dst = (ipfw_obj_dyntlv *)ipfw_get_sopt_space(sd, \ 3066 sizeof(ipfw_obj_dyntlv)); \ 3067 if (dst == NULL) \ 3068 return (ENOMEM); \ 3069 dyn_export_ ## af ## _state(s, &dst->state); \ 3070 dst->head.length = sizeof(ipfw_obj_dyntlv); \ 3071 dst->head.type = IPFW_TLV_DYN_ENT; \ 3072 last = dst; \ 3073 } 3074 3075 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { 3076 DYN_EXPORT_STATES(s4, ipv4, ipv4_parent, bucket); 3077 DYN_EXPORT_STATES(s4, ipv4, ipv4, bucket); 3078#ifdef INET6 3079 DYN_EXPORT_STATES(s6, ipv6, ipv6_parent, bucket); 3080 DYN_EXPORT_STATES(s6, ipv6, ipv6, bucket); 3081#endif /* INET6 */ 3082 } 3083 3084 /* mark last dynamic rule */ 3085 if (last != NULL) 3086 last->head.flags = IPFW_DF_LAST; /* XXX: unused */ 3087 return (0); 3088#undef DYN_EXPORT_STATES 3089} 3090 3091/* 3092 * Fill given buffer with dynamic states (legacy format). 3093 * IPFW_UH_RLOCK has to be held while calling. 3094 */ 3095void 3096ipfw_get_dynamic(struct ip_fw_chain *chain, char **pbp, const char *ep) 3097{ 3098#ifdef INET6 3099 struct dyn_ipv6_state *s6; 3100#endif 3101 struct dyn_ipv4_state *s4; 3102 ipfw_dyn_rule *p, *last = NULL; 3103 char *bp; 3104 uint32_t bucket; 3105 3106 if (V_dyn_count == 0) 3107 return; 3108 bp = *pbp; 3109 3110 IPFW_UH_RLOCK_ASSERT(chain); 3111 3112#define DYN_EXPORT_STATES(s, af, head, b) \ 3113 CK_SLIST_FOREACH(s, &V_dyn_ ## head[b], entry) { \ 3114 if (bp + sizeof(*p) > ep) \ 3115 break; \ 3116 p = (ipfw_dyn_rule *)bp; \ 3117 dyn_export_ ## af ## _state(s, p); \ 3118 last = p; \ 3119 bp += sizeof(*p); \ 3120 } 3121 3122 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { 3123 DYN_EXPORT_STATES(s4, ipv4, ipv4_parent, bucket); 3124 DYN_EXPORT_STATES(s4, ipv4, ipv4, bucket); 3125#ifdef INET6 3126 DYN_EXPORT_STATES(s6, ipv6, ipv6_parent, bucket); 3127 DYN_EXPORT_STATES(s6, ipv6, ipv6, bucket); 3128#endif /* INET6 */ 3129 } 3130 3131 if (last != NULL) /* mark last dynamic rule */ 3132 last->next = NULL; 3133 *pbp = bp; 3134#undef DYN_EXPORT_STATES 3135} 3136 3137void 3138ipfw_dyn_init(struct ip_fw_chain *chain) 3139{ 3140 3141#ifdef IPFIREWALL_JENKINSHASH 3142 V_dyn_hashseed = arc4random(); 3143#endif 3144 V_dyn_max = 16384; /* max # of states */ 3145 V_dyn_parent_max = 4096; /* max # of parent states */ 3146 V_dyn_buckets_max = 8192; /* must be power of 2 */ 3147 3148 V_dyn_ack_lifetime = 300; 3149 V_dyn_syn_lifetime = 20; 3150 V_dyn_fin_lifetime = 1; 3151 V_dyn_rst_lifetime = 1; 3152 V_dyn_udp_lifetime = 10; 3153 V_dyn_short_lifetime = 5; 3154 3155 V_dyn_keepalive_interval = 20; 3156 V_dyn_keepalive_period = 5; 3157 V_dyn_keepalive = 1; /* send keepalives */ 3158 V_dyn_keepalive_last = time_uptime; 3159 3160 V_dyn_data_zone = uma_zcreate("IPFW dynamic states data", 3161 sizeof(struct dyn_data), NULL, NULL, NULL, NULL, 3162 UMA_ALIGN_PTR, 0); 3163 uma_zone_set_max(V_dyn_data_zone, V_dyn_max); 3164 3165 V_dyn_parent_zone = uma_zcreate("IPFW parent dynamic states", 3166 sizeof(struct dyn_parent), NULL, NULL, NULL, NULL, 3167 UMA_ALIGN_PTR, 0); 3168 uma_zone_set_max(V_dyn_parent_zone, V_dyn_parent_max); 3169 3170 SLIST_INIT(&V_dyn_expired_ipv4); 3171 V_dyn_ipv4 = NULL; 3172 V_dyn_ipv4_parent = NULL; 3173 V_dyn_ipv4_zone = uma_zcreate("IPFW IPv4 dynamic states", 3174 sizeof(struct dyn_ipv4_state), NULL, NULL, NULL, NULL, 3175 UMA_ALIGN_PTR, 0); 3176 3177#ifdef INET6 3178 SLIST_INIT(&V_dyn_expired_ipv6); 3179 V_dyn_ipv6 = NULL; 3180 V_dyn_ipv6_parent = NULL; 3181 V_dyn_ipv6_zone = uma_zcreate("IPFW IPv6 dynamic states", 3182 sizeof(struct dyn_ipv6_state), NULL, NULL, NULL, NULL, 3183 UMA_ALIGN_PTR, 0); 3184#endif 3185 3186 /* Initialize buckets. */ 3187 V_curr_dyn_buckets = 0; 3188 V_dyn_bucket_lock = NULL; 3189 dyn_grow_hashtable(chain, 256); 3190 3191 if (IS_DEFAULT_VNET(curvnet)) 3192 dyn_hp_cache = malloc(mp_ncpus * sizeof(void *), M_IPFW, 3193 M_WAITOK | M_ZERO); 3194 3195 DYN_EXPIRED_LOCK_INIT(); 3196 callout_init(&V_dyn_timeout, 1); 3197 callout_reset(&V_dyn_timeout, hz, dyn_tick, curvnet); 3198 IPFW_ADD_OBJ_REWRITER(IS_DEFAULT_VNET(curvnet), dyn_opcodes); 3199} 3200 3201void 3202ipfw_dyn_uninit(int pass) 3203{ 3204#ifdef INET6 3205 struct dyn_ipv6_state *s6; 3206#endif 3207 struct dyn_ipv4_state *s4; 3208 int bucket; 3209 3210 if (pass == 0) { 3211 callout_drain(&V_dyn_timeout); 3212 return; 3213 } 3214 IPFW_DEL_OBJ_REWRITER(IS_DEFAULT_VNET(curvnet), dyn_opcodes); 3215 DYN_EXPIRED_LOCK_DESTROY(); 3216 3217#define DYN_FREE_STATES_FORCED(CK, s, af, name, en) do { \ 3218 while ((s = CK ## SLIST_FIRST(&V_dyn_ ## name)) != NULL) { \ 3219 CK ## SLIST_REMOVE_HEAD(&V_dyn_ ## name, en); \ 3220 if (s->type == O_LIMIT_PARENT) \ 3221 uma_zfree(V_dyn_parent_zone, s->limit); \ 3222 else \ 3223 uma_zfree(V_dyn_data_zone, s->data); \ 3224 uma_zfree(V_dyn_ ## af ## _zone, s); \ 3225 } \ 3226} while (0) 3227 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { 3228 DYN_BUCKET_LOCK_DESTROY(V_dyn_bucket_lock, bucket); 3229 3230 DYN_FREE_STATES_FORCED(CK_, s4, ipv4, ipv4[bucket], entry); 3231 DYN_FREE_STATES_FORCED(CK_, s4, ipv4, ipv4_parent[bucket], 3232 entry); 3233#ifdef INET6 3234 DYN_FREE_STATES_FORCED(CK_, s6, ipv6, ipv6[bucket], entry); 3235 DYN_FREE_STATES_FORCED(CK_, s6, ipv6, ipv6_parent[bucket], 3236 entry); 3237#endif /* INET6 */ 3238 } 3239 DYN_FREE_STATES_FORCED(, s4, ipv4, expired_ipv4, expired); 3240#ifdef INET6 3241 DYN_FREE_STATES_FORCED(, s6, ipv6, expired_ipv6, expired); 3242#endif 3243#undef DYN_FREE_STATES_FORCED 3244 3245 uma_zdestroy(V_dyn_ipv4_zone); 3246 uma_zdestroy(V_dyn_data_zone); 3247 uma_zdestroy(V_dyn_parent_zone); 3248#ifdef INET6 3249 uma_zdestroy(V_dyn_ipv6_zone); 3250 free(V_dyn_ipv6, M_IPFW); 3251 free(V_dyn_ipv6_parent, M_IPFW); 3252 free(V_dyn_ipv6_add, M_IPFW); 3253 free(V_dyn_ipv6_parent_add, M_IPFW); 3254 free(V_dyn_ipv6_del, M_IPFW); 3255 free(V_dyn_ipv6_parent_del, M_IPFW); 3256#endif 3257 free(V_dyn_bucket_lock, M_IPFW); 3258 free(V_dyn_ipv4, M_IPFW); 3259 free(V_dyn_ipv4_parent, M_IPFW); 3260 free(V_dyn_ipv4_add, M_IPFW); 3261 free(V_dyn_ipv4_parent_add, M_IPFW); 3262 free(V_dyn_ipv4_del, M_IPFW); 3263 free(V_dyn_ipv4_parent_del, M_IPFW); 3264 if (IS_DEFAULT_VNET(curvnet)) 3265 free(dyn_hp_cache, M_IPFW); 3266} 3267 3268 3269