1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2017-2018 Yandex LLC 5 * Copyright (c) 2017-2018 Andrey V. Elsukov <ae@FreeBSD.org> 6 * Copyright (c) 2002 Luigi Rizzo, Universita` di Pisa 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include "opt_inet.h" 34 #include "opt_inet6.h" 35 #include "opt_ipfw.h" 36 #ifndef INET 37 #error IPFIREWALL requires INET. 38 #endif /* INET */ 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/hash.h> 43 #include <sys/mbuf.h> 44 #include <sys/kernel.h> 45 #include <sys/lock.h> 46 #include <sys/pcpu.h> 47 #include <sys/queue.h> 48 #include <sys/rmlock.h> 49 #include <sys/smp.h> 50 #include <sys/socket.h> 51 #include <sys/sysctl.h> 52 #include <sys/syslog.h> 53 #include <net/ethernet.h> 54 #include <net/if.h> 55 #include <net/if_var.h> 56 #include <net/vnet.h> 57 58 #include <netinet/in.h> 59 #include <netinet/ip.h> 60 #include <netinet/ip_var.h> 61 #include <netinet/ip_fw.h> 62 #include <netinet/tcp_var.h> 63 #include <netinet/udp.h> 64 65 #include <netinet/ip6.h> /* IN6_ARE_ADDR_EQUAL */ 66 #ifdef INET6 67 #include <netinet6/in6_var.h> 68 #include <netinet6/ip6_var.h> 69 #include <netinet6/scope6_var.h> 70 #endif 71 72 #include <netpfil/ipfw/ip_fw_private.h> 73 74 #include <machine/in_cksum.h> /* XXX for in_cksum */ 75 76 #ifdef MAC 77 #include <security/mac/mac_framework.h> 78 #endif 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 */ 129 130 struct 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) 161 struct 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 }; 170 171 struct 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 }; 185 CK_SLIST_HEAD(dyn_ipv4ck_slist, dyn_ipv4_state); 186 VNET_DEFINE_STATIC(struct dyn_ipv4ck_slist *, dyn_ipv4); 187 VNET_DEFINE_STATIC(struct dyn_ipv4ck_slist *, dyn_ipv4_parent); 188 189 SLIST_HEAD(dyn_ipv4_slist, dyn_ipv4_state); 190 VNET_DEFINE_STATIC(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 196 struct 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 }; 210 CK_SLIST_HEAD(dyn_ipv6ck_slist, dyn_ipv6_state); 211 VNET_DEFINE_STATIC(struct dyn_ipv6ck_slist *, dyn_ipv6); 212 VNET_DEFINE_STATIC(struct dyn_ipv6ck_slist *, dyn_ipv6_parent); 213 214 SLIST_HEAD(dyn_ipv6_slist, dyn_ipv6_state); 215 VNET_DEFINE_STATIC(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 */ 225 static void **dyn_hp_cache; 226 DPCPU_DEFINE_STATIC(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 */ 262 VNET_DEFINE_STATIC(struct mtx, dyn_expire_lock); 263 VNET_DEFINE_STATIC(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 */ 270 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_add); 271 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_del); 272 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_parent_add); 273 VNET_DEFINE_STATIC(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 280 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_add); 281 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_del); 282 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_parent_add); 283 VNET_DEFINE_STATIC(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) 306 307 VNET_DEFINE_STATIC(uint32_t, dyn_buckets_max); 308 VNET_DEFINE_STATIC(uint32_t, curr_dyn_buckets); 309 VNET_DEFINE_STATIC(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 */ 315 VNET_DEFINE_STATIC(uint32_t, curr_max_length); 316 #define V_curr_max_length VNET(curr_max_length) 317 318 VNET_DEFINE_STATIC(uint32_t, dyn_keep_states); 319 #define V_dyn_keep_states VNET(dyn_keep_states) 320 321 VNET_DEFINE_STATIC(uma_zone_t, dyn_data_zone); 322 VNET_DEFINE_STATIC(uma_zone_t, dyn_parent_zone); 323 VNET_DEFINE_STATIC(uma_zone_t, dyn_ipv4_zone); 324 #ifdef INET6 325 VNET_DEFINE_STATIC(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 */ 335 VNET_DEFINE_STATIC(uint32_t, dyn_ack_lifetime); 336 VNET_DEFINE_STATIC(uint32_t, dyn_syn_lifetime); 337 VNET_DEFINE_STATIC(uint32_t, dyn_fin_lifetime); 338 VNET_DEFINE_STATIC(uint32_t, dyn_rst_lifetime); 339 VNET_DEFINE_STATIC(uint32_t, dyn_udp_lifetime); 340 VNET_DEFINE_STATIC(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 */ 356 VNET_DEFINE_STATIC(uint32_t, dyn_keepalive_interval); 357 VNET_DEFINE_STATIC(uint32_t, dyn_keepalive_period); 358 VNET_DEFINE_STATIC(uint32_t, dyn_keepalive); 359 VNET_DEFINE_STATIC(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) 365 366 VNET_DEFINE_STATIC(uint32_t, dyn_max); /* max # of dynamic states */ 367 VNET_DEFINE_STATIC(uint32_t, dyn_count); /* number of states */ 368 VNET_DEFINE_STATIC(uint32_t, dyn_parent_max); /* max # of parent states */ 369 VNET_DEFINE_STATIC(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)) 382 383 static time_t last_log; /* Log ratelimiting */ 384 385 /* 386 * Get/set maximum number of dynamic states in given VNET instance. 387 */ 388 static int 389 sysctl_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 } 404 405 static int 406 sysctl_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 } 421 422 static int 423 sysctl_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 } 440 441 SYSCTL_DECL(_net_inet_ip_fw); 442 443 SYSCTL_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."); 446 SYSCTL_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. "); 449 SYSCTL_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."); 452 SYSCTL_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."); 455 SYSCTL_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."); 458 SYSCTL_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."); 461 SYSCTL_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."); 464 SYSCTL_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."); 467 SYSCTL_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."); 470 SYSCTL_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."); 473 SYSCTL_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."); 476 SYSCTL_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."); 479 SYSCTL_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."); 482 SYSCTL_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."); 485 SYSCTL_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 */ 500 static struct dyn_ipv6_state *dyn_lookup_ipv6_state( 501 const struct ipfw_flow_id *, uint32_t, const void *, 502 struct ipfw_dyn_info *, int); 503 static int dyn_lookup_ipv6_state_locked(const struct ipfw_flow_id *, 504 uint32_t, const void *, int, uint32_t, uint16_t); 505 static struct dyn_ipv6_state *dyn_alloc_ipv6_state( 506 const struct ipfw_flow_id *, uint32_t, uint16_t, uint8_t); 507 static 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); 510 static void dyn_export_ipv6_state(const struct dyn_ipv6_state *, 511 ipfw_dyn_rule *); 512 513 static uint32_t dyn_getscopeid(const struct ip_fw_args *); 514 static 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); 517 static void dyn_enqueue_keepalive_ipv6(struct mbufq *, 518 const struct dyn_ipv6_state *); 519 static void dyn_send_keepalive_ipv6(struct ip_fw_chain *); 520 521 static 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); 524 static 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); 527 static 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 */ 532 static void *dyn_get_parent_state(const struct ipfw_flow_id *, uint32_t, 533 struct ip_fw *, uint32_t, uint32_t, uint16_t); 534 static struct dyn_ipv4_state *dyn_lookup_ipv4_parent( 535 const struct ipfw_flow_id *, const void *, uint32_t, uint16_t, uint32_t); 536 static struct dyn_ipv4_state *dyn_lookup_ipv4_parent_locked( 537 const struct ipfw_flow_id *, const void *, uint32_t, uint16_t, uint32_t); 538 static struct dyn_parent *dyn_alloc_parent(void *, uint32_t, uint16_t, 539 uint32_t); 540 static 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); 542 543 static void dyn_tick(void *); 544 static void dyn_expire_states(struct ip_fw_chain *, ipfw_range_tlv *); 545 static void dyn_free_states(struct ip_fw_chain *); 546 static void dyn_export_parent(const struct dyn_parent *, uint16_t, uint8_t, 547 ipfw_dyn_rule *); 548 static void dyn_export_data(const struct dyn_data *, uint16_t, uint8_t, 549 uint8_t, ipfw_dyn_rule *); 550 static uint32_t dyn_update_tcp_state(struct dyn_data *, 551 const struct ipfw_flow_id *, const struct tcphdr *, int); 552 static 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 */ 556 struct dyn_ipv4_state *dyn_lookup_ipv4_state(const struct ipfw_flow_id *, 557 const void *, struct ipfw_dyn_info *, int); 558 static int dyn_lookup_ipv4_state_locked(const struct ipfw_flow_id *, 559 const void *, int, uint32_t, uint16_t); 560 static struct dyn_ipv4_state *dyn_alloc_ipv4_state( 561 const struct ipfw_flow_id *, uint16_t, uint8_t); 562 static 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); 565 static void dyn_export_ipv4_state(const struct dyn_ipv4_state *, 566 ipfw_dyn_rule *); 567 568 /* 569 * Named states support. 570 */ 571 static char *default_state_name = "default"; 572 struct 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 */ 584 static int 585 dyn_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 } 598 599 static void 600 dyn_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 } 606 607 static int 608 dyn_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 } 640 641 static struct named_object * 642 dyn_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 } 648 649 static int 650 dyn_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 } 706 707 static void 708 dyn_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 } 727 728 static 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 761 static __inline uint32_t 762 hash_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 } 778 779 static __inline uint32_t 780 hash_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 */ 787 788 VNET_DEFINE_STATIC(uint32_t, dyn_hashseed); 789 #define V_dyn_hashseed VNET(dyn_hashseed) 790 791 static __inline int 792 addrcmp4(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 805 static __inline int 806 addrcmp6(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 } 819 820 static __inline uint32_t 821 hash_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 843 844 static __inline uint32_t 845 hash_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 } 874 875 static __inline uint32_t 876 hash_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 */ 887 static void 888 print_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) 927 928 static uint32_t 929 dyn_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 */ 1003 static void 1004 dyn_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 */ 1038 struct dyn_ipv4_state * 1039 dyn_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); 1047 restart: 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 */ 1079 static int 1080 dyn_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 1109 struct dyn_ipv4_state * 1110 dyn_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); 1117 restart: 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 1145 static struct dyn_ipv4_state * 1146 dyn_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 1167 static uint32_t 1168 dyn_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 */ 1189 static struct dyn_ipv6_state * 1190 dyn_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); 1198 restart: 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 */ 1231 static int 1232 dyn_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 1262 static struct dyn_ipv6_state * 1263 dyn_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); 1270 restart: 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 1299 static struct dyn_ipv6_state * 1300 dyn_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 */ 1331 struct ip_fw * 1332 ipfw_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 1457 static struct dyn_parent * 1458 dyn_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 1483 static struct dyn_data * 1484 dyn_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 1511 static struct dyn_ipv4_state * 1512 dyn_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 */ 1538 static struct dyn_ipv4_state * 1539 dyn_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 1591 static int 1592 dyn_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 1641 static struct dyn_ipv6_state * 1642 dyn_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 */ 1669 static struct dyn_ipv6_state * 1670 dyn_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 1722 static int 1723 dyn_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 1772 static void * 1773 dyn_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 1864 static int 1865 dyn_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; 1872 int ret; 1873 1874 MPASS(type == O_LIMIT || type == O_KEEP_STATE); 1875 1876 if (type == O_LIMIT) { 1877 /* Create masked flow id and calculate bucket */ 1878 id.addr_type = pkt->addr_type; 1879 id.proto = pkt->proto; 1880 id.fib = fibnum; /* unused */ 1881 id.src_port = (limit_mask & DYN_SRC_PORT) ? 1882 pkt->src_port: 0; 1883 id.dst_port = (limit_mask & DYN_DST_PORT) ? 1884 pkt->dst_port: 0; 1885 if (IS_IP4_FLOW_ID(pkt)) { 1886 id.src_ip = (limit_mask & DYN_SRC_ADDR) ? 1887 pkt->src_ip: 0; 1888 id.dst_ip = (limit_mask & DYN_DST_ADDR) ? 1889 pkt->dst_ip: 0; 1890 } 1891 #ifdef INET6 1892 else if (IS_IP6_FLOW_ID(pkt)) { 1893 if (limit_mask & DYN_SRC_ADDR) 1894 id.src_ip6 = pkt->src_ip6; 1895 else 1896 memset(&id.src_ip6, 0, sizeof(id.src_ip6)); 1897 if (limit_mask & DYN_DST_ADDR) 1898 id.dst_ip6 = pkt->dst_ip6; 1899 else 1900 memset(&id.dst_ip6, 0, sizeof(id.dst_ip6)); 1901 } 1902 #endif 1903 else 1904 return (EAFNOSUPPORT); 1905 1906 parent_hashval = hash_parent(&id, rule); 1907 rule = dyn_get_parent_state(&id, zoneid, rule, parent_hashval, 1908 limit, kidx); 1909 if (rule == NULL) { 1910 #if 0 1911 if (V_fw_verbose && last_log != time_uptime) { 1912 last_log = time_uptime; 1913 snprintf(sbuf, sizeof(sbuf), 1914 "%u drop session", rule->rulenum); 1915 print_dyn_rule_flags(pkt, O_LIMIT, 1916 LOG_SECURITY | LOG_DEBUG, sbuf, 1917 "too many entries"); 1918 } 1919 #endif 1920 return (EACCES); 1921 } 1922 /* 1923 * Limit is not reached, create new state. 1924 * Now rule points to parent state. 1925 */ 1926 } 1927 1928 hashval = hash_packet(pkt); 1929 if (IS_IP4_FLOW_ID(pkt)) 1930 ret = dyn_add_ipv4_state(rule, rule->id, rule->rulenum, pkt, 1931 ulp, pktlen, hashval, info, fibnum, kidx, type); 1932 #ifdef INET6 1933 else if (IS_IP6_FLOW_ID(pkt)) 1934 ret = dyn_add_ipv6_state(rule, rule->id, rule->rulenum, pkt, 1935 zoneid, ulp, pktlen, hashval, info, fibnum, kidx, type); 1936 #endif /* INET6 */ 1937 else 1938 ret = EAFNOSUPPORT; 1939 1940 if (type == O_LIMIT) { 1941 if (ret != 0) { 1942 /* 1943 * We failed to create child state for O_LIMIT 1944 * opcode. Since we already counted it in the parent, 1945 * we must revert counter back. The 'rule' points to 1946 * parent state, use it to get dyn_parent. 1947 * 1948 * XXXAE: it should be safe to use 'rule' pointer 1949 * without extra lookup, parent state is referenced 1950 * and should not be freed. 1951 */ 1952 if (IS_IP4_FLOW_ID(&id)) 1953 DPARENT_COUNT_DEC( 1954 ((struct dyn_ipv4_state *)rule)->limit); 1955 #ifdef INET6 1956 else if (IS_IP6_FLOW_ID(&id)) 1957 DPARENT_COUNT_DEC( 1958 ((struct dyn_ipv6_state *)rule)->limit); 1959 #endif 1960 } 1961 } 1962 /* 1963 * EEXIST means that simultaneous thread has created this 1964 * state. Consider this as success. 1965 * 1966 * XXXAE: should we invalidate 'info' content here? 1967 */ 1968 if (ret == EEXIST) 1969 return (0); 1970 return (ret); 1971 } 1972 1973 /* 1974 * Install dynamic state. 1975 * chain - ipfw's instance; 1976 * rule - the parent rule that installs the state; 1977 * cmd - opcode that installs the state; 1978 * args - ipfw arguments; 1979 * ulp - upper level protocol header; 1980 * pktlen - packet length; 1981 * info - dynamic state lookup info; 1982 * tablearg - tablearg id. 1983 * 1984 * Returns non-zero value (failure) if state is not installed because 1985 * of errors or because session limitations are enforced. 1986 */ 1987 int 1988 ipfw_dyn_install_state(struct ip_fw_chain *chain, struct ip_fw *rule, 1989 const ipfw_insn_limit *cmd, const struct ip_fw_args *args, 1990 const void *ulp, int pktlen, struct ipfw_dyn_info *info, 1991 uint32_t tablearg) 1992 { 1993 uint32_t limit; 1994 uint16_t limit_mask; 1995 1996 if (cmd->o.opcode == O_LIMIT) { 1997 limit = IP_FW_ARG_TABLEARG(chain, cmd->conn_limit, limit); 1998 limit_mask = cmd->limit_mask; 1999 } else { 2000 limit = 0; 2001 limit_mask = 0; 2002 } 2003 return (dyn_install_state(&args->f_id, 2004 #ifdef INET6 2005 IS_IP6_FLOW_ID(&args->f_id) ? dyn_getscopeid(args): 2006 #endif 2007 0, M_GETFIB(args->m), ulp, pktlen, rule, info, limit, 2008 limit_mask, cmd->o.arg1, cmd->o.opcode)); 2009 } 2010 2011 /* 2012 * Free safe to remove state entries from expired lists. 2013 */ 2014 static void 2015 dyn_free_states(struct ip_fw_chain *chain) 2016 { 2017 struct dyn_ipv4_state *s4, *s4n; 2018 #ifdef INET6 2019 struct dyn_ipv6_state *s6, *s6n; 2020 #endif 2021 int cached_count, i; 2022 2023 /* 2024 * We keep pointers to objects that are in use on each CPU 2025 * in the per-cpu dyn_hp pointer. When object is going to be 2026 * removed, first of it is unlinked from the corresponding 2027 * list. This leads to changing of dyn_bucket_xxx_delver version. 2028 * Unlinked objects is placed into corresponding dyn_expired_xxx 2029 * list. Reader that is going to dereference object pointer checks 2030 * dyn_bucket_xxx_delver version before and after storing pointer 2031 * into dyn_hp. If version is the same, the object is protected 2032 * from freeing and it is safe to dereference. Othervise reader 2033 * tries to iterate list again from the beginning, but this object 2034 * now unlinked and thus will not be accessible. 2035 * 2036 * Copy dyn_hp pointers for each CPU into dyn_hp_cache array. 2037 * It does not matter that some pointer can be changed in 2038 * time while we are copying. We need to check, that objects 2039 * removed in the previous pass are not in use. And if dyn_hp 2040 * pointer does not contain it in the time when we are copying, 2041 * it will not appear there, because it is already unlinked. 2042 * And for new pointers we will not free objects that will be 2043 * unlinked in this pass. 2044 */ 2045 cached_count = 0; 2046 CPU_FOREACH(i) { 2047 dyn_hp_cache[cached_count] = DYNSTATE_GET(i); 2048 if (dyn_hp_cache[cached_count] != NULL) 2049 cached_count++; 2050 } 2051 2052 /* 2053 * Free expired states that are safe to free. 2054 * Check each entry from previous pass in the dyn_expired_xxx 2055 * list, if pointer to the object is in the dyn_hp_cache array, 2056 * keep it until next pass. Otherwise it is safe to free the 2057 * object. 2058 * 2059 * XXXAE: optimize this to use SLIST_REMOVE_AFTER. 2060 */ 2061 #define DYN_FREE_STATES(s, next, name) do { \ 2062 s = SLIST_FIRST(&V_dyn_expired_ ## name); \ 2063 while (s != NULL) { \ 2064 next = SLIST_NEXT(s, expired); \ 2065 for (i = 0; i < cached_count; i++) \ 2066 if (dyn_hp_cache[i] == s) \ 2067 break; \ 2068 if (i == cached_count) { \ 2069 if (s->type == O_LIMIT_PARENT && \ 2070 s->limit->count != 0) { \ 2071 s = next; \ 2072 continue; \ 2073 } \ 2074 SLIST_REMOVE(&V_dyn_expired_ ## name, \ 2075 s, dyn_ ## name ## _state, expired); \ 2076 if (s->type == O_LIMIT_PARENT) \ 2077 uma_zfree(V_dyn_parent_zone, s->limit); \ 2078 else \ 2079 uma_zfree(V_dyn_data_zone, s->data); \ 2080 uma_zfree(V_dyn_ ## name ## _zone, s); \ 2081 } \ 2082 s = next; \ 2083 } \ 2084 } while (0) 2085 2086 /* 2087 * Protect access to expired lists with DYN_EXPIRED_LOCK. 2088 * Userland can invoke ipfw_expire_dyn_states() to delete 2089 * specific states, this will lead to modification of expired 2090 * lists. 2091 * 2092 * XXXAE: do we need DYN_EXPIRED_LOCK? We can just use 2093 * IPFW_UH_WLOCK to protect access to these lists. 2094 */ 2095 DYN_EXPIRED_LOCK(); 2096 DYN_FREE_STATES(s4, s4n, ipv4); 2097 #ifdef INET6 2098 DYN_FREE_STATES(s6, s6n, ipv6); 2099 #endif 2100 DYN_EXPIRED_UNLOCK(); 2101 #undef DYN_FREE_STATES 2102 } 2103 2104 /* 2105 * Returns: 2106 * 0 when state is not matched by specified range; 2107 * 1 when state is matched by specified range; 2108 * 2 when state is matched by specified range and requested deletion of 2109 * dynamic states. 2110 */ 2111 static int 2112 dyn_match_range(uint16_t rulenum, uint8_t set, const ipfw_range_tlv *rt) 2113 { 2114 2115 MPASS(rt != NULL); 2116 /* flush all states */ 2117 if (rt->flags & IPFW_RCFLAG_ALL) { 2118 if (rt->flags & IPFW_RCFLAG_DYNAMIC) 2119 return (2); /* forced */ 2120 return (1); 2121 } 2122 if ((rt->flags & IPFW_RCFLAG_SET) != 0 && set != rt->set) 2123 return (0); 2124 if ((rt->flags & IPFW_RCFLAG_RANGE) != 0 && 2125 (rulenum < rt->start_rule || rulenum > rt->end_rule)) 2126 return (0); 2127 if (rt->flags & IPFW_RCFLAG_DYNAMIC) 2128 return (2); 2129 return (1); 2130 } 2131 2132 static void 2133 dyn_acquire_rule(struct ip_fw_chain *ch, struct dyn_data *data, 2134 struct ip_fw *rule, uint16_t kidx) 2135 { 2136 struct dyn_state_obj *obj; 2137 2138 /* 2139 * Do not acquire reference twice. 2140 * This can happen when rule deletion executed for 2141 * the same range, but different ruleset id. 2142 */ 2143 if (data->flags & DYN_REFERENCED) 2144 return; 2145 2146 IPFW_UH_WLOCK_ASSERT(ch); 2147 MPASS(kidx != 0); 2148 2149 data->flags |= DYN_REFERENCED; 2150 /* Reference the named object */ 2151 obj = SRV_OBJECT(ch, kidx); 2152 obj->no.refcnt++; 2153 MPASS(obj->no.etlv == IPFW_TLV_STATE_NAME); 2154 2155 /* Reference the parent rule */ 2156 rule->refcnt++; 2157 } 2158 2159 static void 2160 dyn_release_rule(struct ip_fw_chain *ch, struct dyn_data *data, 2161 struct ip_fw *rule, uint16_t kidx) 2162 { 2163 struct dyn_state_obj *obj; 2164 2165 IPFW_UH_WLOCK_ASSERT(ch); 2166 MPASS(kidx != 0); 2167 2168 obj = SRV_OBJECT(ch, kidx); 2169 if (obj->no.refcnt == 1) 2170 dyn_destroy(ch, &obj->no); 2171 else 2172 obj->no.refcnt--; 2173 2174 if (--rule->refcnt == 1) 2175 ipfw_free_rule(rule); 2176 } 2177 2178 /* 2179 * We do not keep O_LIMIT_PARENT states when V_dyn_keep_states is enabled. 2180 * O_LIMIT state is created when new connection is going to be established 2181 * and there is no matching state. So, since the old parent rule was deleted 2182 * we can't create new states with old parent, and thus we can not account 2183 * new connections with already established connections, and can not do 2184 * proper limiting. 2185 */ 2186 static int 2187 dyn_match_ipv4_state(struct ip_fw_chain *ch, struct dyn_ipv4_state *s, 2188 const ipfw_range_tlv *rt) 2189 { 2190 struct ip_fw *rule; 2191 int ret; 2192 2193 if (s->type == O_LIMIT_PARENT) { 2194 rule = s->limit->parent; 2195 return (dyn_match_range(s->limit->rulenum, rule->set, rt)); 2196 } 2197 2198 rule = s->data->parent; 2199 if (s->type == O_LIMIT) 2200 rule = ((struct dyn_ipv4_state *)rule)->limit->parent; 2201 2202 ret = dyn_match_range(s->data->rulenum, rule->set, rt); 2203 if (ret == 0 || V_dyn_keep_states == 0 || ret > 1) 2204 return (ret); 2205 2206 dyn_acquire_rule(ch, s->data, rule, s->kidx); 2207 return (0); 2208 } 2209 2210 #ifdef INET6 2211 static int 2212 dyn_match_ipv6_state(struct ip_fw_chain *ch, struct dyn_ipv6_state *s, 2213 const ipfw_range_tlv *rt) 2214 { 2215 struct ip_fw *rule; 2216 int ret; 2217 2218 if (s->type == O_LIMIT_PARENT) { 2219 rule = s->limit->parent; 2220 return (dyn_match_range(s->limit->rulenum, rule->set, rt)); 2221 } 2222 2223 rule = s->data->parent; 2224 if (s->type == O_LIMIT) 2225 rule = ((struct dyn_ipv6_state *)rule)->limit->parent; 2226 2227 ret = dyn_match_range(s->data->rulenum, rule->set, rt); 2228 if (ret == 0 || V_dyn_keep_states == 0 || ret > 1) 2229 return (ret); 2230 2231 dyn_acquire_rule(ch, s->data, rule, s->kidx); 2232 return (0); 2233 } 2234 #endif 2235 2236 /* 2237 * Unlink expired entries from states lists. 2238 * @rt can be used to specify the range of states for deletion. 2239 */ 2240 static void 2241 dyn_expire_states(struct ip_fw_chain *ch, ipfw_range_tlv *rt) 2242 { 2243 struct dyn_ipv4_slist expired_ipv4; 2244 #ifdef INET6 2245 struct dyn_ipv6_slist expired_ipv6; 2246 struct dyn_ipv6_state *s6, *s6n, *s6p; 2247 #endif 2248 struct dyn_ipv4_state *s4, *s4n, *s4p; 2249 void *rule; 2250 int bucket, removed, length, max_length; 2251 2252 IPFW_UH_WLOCK_ASSERT(ch); 2253 2254 /* 2255 * Unlink expired states from each bucket. 2256 * With acquired bucket lock iterate entries of each lists: 2257 * ipv4, ipv4_parent, ipv6, and ipv6_parent. Check expired time 2258 * and unlink entry from the list, link entry into temporary 2259 * expired_xxx lists then bump "del" bucket version. 2260 * 2261 * When an entry is removed, corresponding states counter is 2262 * decremented. If entry has O_LIMIT type, parent's reference 2263 * counter is decremented. 2264 * 2265 * NOTE: this function can be called from userspace context 2266 * when user deletes rules. In this case all matched states 2267 * will be forcedly unlinked. O_LIMIT_PARENT states will be kept 2268 * in the expired lists until reference counter become zero. 2269 */ 2270 #define DYN_UNLINK_STATES(s, prev, next, exp, af, name, extra) do { \ 2271 length = 0; \ 2272 removed = 0; \ 2273 prev = NULL; \ 2274 s = CK_SLIST_FIRST(&V_dyn_ ## name [bucket]); \ 2275 while (s != NULL) { \ 2276 next = CK_SLIST_NEXT(s, entry); \ 2277 if ((TIME_LEQ((s)->exp, time_uptime) && extra) || \ 2278 (rt != NULL && \ 2279 dyn_match_ ## af ## _state(ch, s, rt))) { \ 2280 if (prev != NULL) \ 2281 CK_SLIST_REMOVE_AFTER(prev, entry); \ 2282 else \ 2283 CK_SLIST_REMOVE_HEAD( \ 2284 &V_dyn_ ## name [bucket], entry); \ 2285 removed++; \ 2286 SLIST_INSERT_HEAD(&expired_ ## af, s, expired); \ 2287 if (s->type == O_LIMIT_PARENT) \ 2288 DYN_COUNT_DEC(dyn_parent_count); \ 2289 else { \ 2290 DYN_COUNT_DEC(dyn_count); \ 2291 if (s->data->flags & DYN_REFERENCED) { \ 2292 rule = s->data->parent; \ 2293 if (s->type == O_LIMIT) \ 2294 rule = ((__typeof(s)) \ 2295 rule)->limit->parent;\ 2296 dyn_release_rule(ch, s->data, \ 2297 rule, s->kidx); \ 2298 } \ 2299 if (s->type == O_LIMIT) { \ 2300 s = s->data->parent; \ 2301 DPARENT_COUNT_DEC(s->limit); \ 2302 } \ 2303 } \ 2304 } else { \ 2305 prev = s; \ 2306 length++; \ 2307 } \ 2308 s = next; \ 2309 } \ 2310 if (removed != 0) \ 2311 DYN_BUCKET_VERSION_BUMP(bucket, name ## _del); \ 2312 if (length > max_length) \ 2313 max_length = length; \ 2314 } while (0) 2315 2316 SLIST_INIT(&expired_ipv4); 2317 #ifdef INET6 2318 SLIST_INIT(&expired_ipv6); 2319 #endif 2320 max_length = 0; 2321 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { 2322 DYN_BUCKET_LOCK(bucket); 2323 DYN_UNLINK_STATES(s4, s4p, s4n, data->expire, ipv4, ipv4, 1); 2324 DYN_UNLINK_STATES(s4, s4p, s4n, limit->expire, ipv4, 2325 ipv4_parent, (s4->limit->count == 0)); 2326 #ifdef INET6 2327 DYN_UNLINK_STATES(s6, s6p, s6n, data->expire, ipv6, ipv6, 1); 2328 DYN_UNLINK_STATES(s6, s6p, s6n, limit->expire, ipv6, 2329 ipv6_parent, (s6->limit->count == 0)); 2330 #endif 2331 DYN_BUCKET_UNLOCK(bucket); 2332 } 2333 /* Update curr_max_length for statistics. */ 2334 V_curr_max_length = max_length; 2335 /* 2336 * Concatenate temporary lists with global expired lists. 2337 */ 2338 DYN_EXPIRED_LOCK(); 2339 SLIST_CONCAT(&V_dyn_expired_ipv4, &expired_ipv4, 2340 dyn_ipv4_state, expired); 2341 #ifdef INET6 2342 SLIST_CONCAT(&V_dyn_expired_ipv6, &expired_ipv6, 2343 dyn_ipv6_state, expired); 2344 #endif 2345 DYN_EXPIRED_UNLOCK(); 2346 #undef DYN_UNLINK_STATES 2347 #undef DYN_UNREF_STATES 2348 } 2349 2350 static struct mbuf * 2351 dyn_mgethdr(int len, uint16_t fibnum) 2352 { 2353 struct mbuf *m; 2354 2355 m = m_gethdr(M_NOWAIT, MT_DATA); 2356 if (m == NULL) 2357 return (NULL); 2358 #ifdef MAC 2359 mac_netinet_firewall_send(m); 2360 #endif 2361 M_SETFIB(m, fibnum); 2362 m->m_data += max_linkhdr; 2363 m->m_flags |= M_SKIP_FIREWALL; 2364 m->m_len = m->m_pkthdr.len = len; 2365 bzero(m->m_data, len); 2366 return (m); 2367 } 2368 2369 static void 2370 dyn_make_keepalive_ipv4(struct mbuf *m, in_addr_t src, in_addr_t dst, 2371 uint32_t seq, uint32_t ack, uint16_t sport, uint16_t dport) 2372 { 2373 struct tcphdr *tcp; 2374 struct ip *ip; 2375 2376 ip = mtod(m, struct ip *); 2377 ip->ip_v = 4; 2378 ip->ip_hl = sizeof(*ip) >> 2; 2379 ip->ip_tos = IPTOS_LOWDELAY; 2380 ip->ip_len = htons(m->m_len); 2381 ip->ip_off |= htons(IP_DF); 2382 ip->ip_ttl = V_ip_defttl; 2383 ip->ip_p = IPPROTO_TCP; 2384 ip->ip_src.s_addr = htonl(src); 2385 ip->ip_dst.s_addr = htonl(dst); 2386 2387 tcp = mtodo(m, sizeof(struct ip)); 2388 tcp->th_sport = htons(sport); 2389 tcp->th_dport = htons(dport); 2390 tcp->th_off = sizeof(struct tcphdr) >> 2; 2391 tcp->th_seq = htonl(seq); 2392 tcp->th_ack = htonl(ack); 2393 tcp->th_flags = TH_ACK; 2394 tcp->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 2395 htons(sizeof(struct tcphdr) + IPPROTO_TCP)); 2396 2397 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2398 m->m_pkthdr.csum_flags = CSUM_TCP; 2399 } 2400 2401 static void 2402 dyn_enqueue_keepalive_ipv4(struct mbufq *q, const struct dyn_ipv4_state *s) 2403 { 2404 struct mbuf *m; 2405 2406 if ((s->data->state & ACK_FWD) == 0 && s->data->ack_fwd > 0) { 2407 m = dyn_mgethdr(sizeof(struct ip) + sizeof(struct tcphdr), 2408 s->data->fibnum); 2409 if (m != NULL) { 2410 dyn_make_keepalive_ipv4(m, s->dst, s->src, 2411 s->data->ack_fwd - 1, s->data->ack_rev, 2412 s->dport, s->sport); 2413 if (mbufq_enqueue(q, m)) { 2414 m_freem(m); 2415 log(LOG_DEBUG, "ipfw: limit for IPv4 " 2416 "keepalive queue is reached.\n"); 2417 return; 2418 } 2419 } 2420 } 2421 2422 if ((s->data->state & ACK_REV) == 0 && s->data->ack_rev > 0) { 2423 m = dyn_mgethdr(sizeof(struct ip) + sizeof(struct tcphdr), 2424 s->data->fibnum); 2425 if (m != NULL) { 2426 dyn_make_keepalive_ipv4(m, s->src, s->dst, 2427 s->data->ack_rev - 1, s->data->ack_fwd, 2428 s->sport, s->dport); 2429 if (mbufq_enqueue(q, m)) { 2430 m_freem(m); 2431 log(LOG_DEBUG, "ipfw: limit for IPv4 " 2432 "keepalive queue is reached.\n"); 2433 return; 2434 } 2435 } 2436 } 2437 } 2438 2439 /* 2440 * Prepare and send keep-alive packets. 2441 */ 2442 static void 2443 dyn_send_keepalive_ipv4(struct ip_fw_chain *chain) 2444 { 2445 struct mbufq q; 2446 struct mbuf *m; 2447 struct dyn_ipv4_state *s; 2448 uint32_t bucket; 2449 2450 mbufq_init(&q, INT_MAX); 2451 IPFW_UH_RLOCK(chain); 2452 /* 2453 * It is safe to not use hazard pointer and just do lockless 2454 * access to the lists, because states entries can not be deleted 2455 * while we hold IPFW_UH_RLOCK. 2456 */ 2457 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { 2458 CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) { 2459 /* 2460 * Only established TCP connections that will 2461 * become expired withing dyn_keepalive_interval. 2462 */ 2463 if (s->proto != IPPROTO_TCP || 2464 (s->data->state & BOTH_SYN) != BOTH_SYN || 2465 TIME_LEQ(time_uptime + V_dyn_keepalive_interval, 2466 s->data->expire)) 2467 continue; 2468 dyn_enqueue_keepalive_ipv4(&q, s); 2469 } 2470 } 2471 IPFW_UH_RUNLOCK(chain); 2472 while ((m = mbufq_dequeue(&q)) != NULL) 2473 ip_output(m, NULL, NULL, 0, NULL, NULL); 2474 } 2475 2476 #ifdef INET6 2477 static void 2478 dyn_make_keepalive_ipv6(struct mbuf *m, const struct in6_addr *src, 2479 const struct in6_addr *dst, uint32_t zoneid, uint32_t seq, uint32_t ack, 2480 uint16_t sport, uint16_t dport) 2481 { 2482 struct tcphdr *tcp; 2483 struct ip6_hdr *ip6; 2484 2485 ip6 = mtod(m, struct ip6_hdr *); 2486 ip6->ip6_vfc |= IPV6_VERSION; 2487 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 2488 ip6->ip6_nxt = IPPROTO_TCP; 2489 ip6->ip6_hlim = IPV6_DEFHLIM; 2490 ip6->ip6_src = *src; 2491 if (IN6_IS_ADDR_LINKLOCAL(src)) 2492 ip6->ip6_src.s6_addr16[1] = htons(zoneid & 0xffff); 2493 ip6->ip6_dst = *dst; 2494 if (IN6_IS_ADDR_LINKLOCAL(dst)) 2495 ip6->ip6_dst.s6_addr16[1] = htons(zoneid & 0xffff); 2496 2497 tcp = mtodo(m, sizeof(struct ip6_hdr)); 2498 tcp->th_sport = htons(sport); 2499 tcp->th_dport = htons(dport); 2500 tcp->th_off = sizeof(struct tcphdr) >> 2; 2501 tcp->th_seq = htonl(seq); 2502 tcp->th_ack = htonl(ack); 2503 tcp->th_flags = TH_ACK; 2504 tcp->th_sum = in6_cksum_pseudo(ip6, sizeof(struct tcphdr), 2505 IPPROTO_TCP, 0); 2506 2507 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 2508 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; 2509 } 2510 2511 static void 2512 dyn_enqueue_keepalive_ipv6(struct mbufq *q, const struct dyn_ipv6_state *s) 2513 { 2514 struct mbuf *m; 2515 2516 if ((s->data->state & ACK_FWD) == 0 && s->data->ack_fwd > 0) { 2517 m = dyn_mgethdr(sizeof(struct ip6_hdr) + 2518 sizeof(struct tcphdr), s->data->fibnum); 2519 if (m != NULL) { 2520 dyn_make_keepalive_ipv6(m, &s->dst, &s->src, 2521 s->zoneid, s->data->ack_fwd - 1, s->data->ack_rev, 2522 s->dport, s->sport); 2523 if (mbufq_enqueue(q, m)) { 2524 m_freem(m); 2525 log(LOG_DEBUG, "ipfw: limit for IPv6 " 2526 "keepalive queue is reached.\n"); 2527 return; 2528 } 2529 } 2530 } 2531 2532 if ((s->data->state & ACK_REV) == 0 && s->data->ack_rev > 0) { 2533 m = dyn_mgethdr(sizeof(struct ip6_hdr) + 2534 sizeof(struct tcphdr), s->data->fibnum); 2535 if (m != NULL) { 2536 dyn_make_keepalive_ipv6(m, &s->src, &s->dst, 2537 s->zoneid, s->data->ack_rev - 1, s->data->ack_fwd, 2538 s->sport, s->dport); 2539 if (mbufq_enqueue(q, m)) { 2540 m_freem(m); 2541 log(LOG_DEBUG, "ipfw: limit for IPv6 " 2542 "keepalive queue is reached.\n"); 2543 return; 2544 } 2545 } 2546 } 2547 } 2548 2549 static void 2550 dyn_send_keepalive_ipv6(struct ip_fw_chain *chain) 2551 { 2552 struct mbufq q; 2553 struct mbuf *m; 2554 struct dyn_ipv6_state *s; 2555 uint32_t bucket; 2556 2557 mbufq_init(&q, INT_MAX); 2558 IPFW_UH_RLOCK(chain); 2559 /* 2560 * It is safe to not use hazard pointer and just do lockless 2561 * access to the lists, because states entries can not be deleted 2562 * while we hold IPFW_UH_RLOCK. 2563 */ 2564 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { 2565 CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) { 2566 /* 2567 * Only established TCP connections that will 2568 * become expired withing dyn_keepalive_interval. 2569 */ 2570 if (s->proto != IPPROTO_TCP || 2571 (s->data->state & BOTH_SYN) != BOTH_SYN || 2572 TIME_LEQ(time_uptime + V_dyn_keepalive_interval, 2573 s->data->expire)) 2574 continue; 2575 dyn_enqueue_keepalive_ipv6(&q, s); 2576 } 2577 } 2578 IPFW_UH_RUNLOCK(chain); 2579 while ((m = mbufq_dequeue(&q)) != NULL) 2580 ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); 2581 } 2582 #endif /* INET6 */ 2583 2584 static void 2585 dyn_grow_hashtable(struct ip_fw_chain *chain, uint32_t new) 2586 { 2587 #ifdef INET6 2588 struct dyn_ipv6ck_slist *ipv6, *ipv6_parent; 2589 uint32_t *ipv6_add, *ipv6_del, *ipv6_parent_add, *ipv6_parent_del; 2590 struct dyn_ipv6_state *s6; 2591 #endif 2592 struct dyn_ipv4ck_slist *ipv4, *ipv4_parent; 2593 uint32_t *ipv4_add, *ipv4_del, *ipv4_parent_add, *ipv4_parent_del; 2594 struct dyn_ipv4_state *s4; 2595 struct mtx *bucket_lock; 2596 void *tmp; 2597 uint32_t bucket; 2598 2599 MPASS(powerof2(new)); 2600 DYN_DEBUG("grow hash size %u -> %u", V_curr_dyn_buckets, new); 2601 /* 2602 * Allocate and initialize new lists. 2603 * XXXAE: on memory pressure this can disable callout timer. 2604 */ 2605 bucket_lock = malloc(new * sizeof(struct mtx), M_IPFW, 2606 M_WAITOK | M_ZERO); 2607 ipv4 = malloc(new * sizeof(struct dyn_ipv4ck_slist), M_IPFW, 2608 M_WAITOK | M_ZERO); 2609 ipv4_parent = malloc(new * sizeof(struct dyn_ipv4ck_slist), M_IPFW, 2610 M_WAITOK | M_ZERO); 2611 ipv4_add = malloc(new * sizeof(uint32_t), M_IPFW, M_WAITOK | M_ZERO); 2612 ipv4_del = malloc(new * sizeof(uint32_t), M_IPFW, M_WAITOK | M_ZERO); 2613 ipv4_parent_add = malloc(new * sizeof(uint32_t), M_IPFW, 2614 M_WAITOK | M_ZERO); 2615 ipv4_parent_del = malloc(new * sizeof(uint32_t), M_IPFW, 2616 M_WAITOK | M_ZERO); 2617 #ifdef INET6 2618 ipv6 = malloc(new * sizeof(struct dyn_ipv6ck_slist), M_IPFW, 2619 M_WAITOK | M_ZERO); 2620 ipv6_parent = malloc(new * sizeof(struct dyn_ipv6ck_slist), M_IPFW, 2621 M_WAITOK | M_ZERO); 2622 ipv6_add = malloc(new * sizeof(uint32_t), M_IPFW, M_WAITOK | M_ZERO); 2623 ipv6_del = malloc(new * sizeof(uint32_t), M_IPFW, M_WAITOK | M_ZERO); 2624 ipv6_parent_add = malloc(new * sizeof(uint32_t), M_IPFW, 2625 M_WAITOK | M_ZERO); 2626 ipv6_parent_del = malloc(new * sizeof(uint32_t), M_IPFW, 2627 M_WAITOK | M_ZERO); 2628 #endif 2629 for (bucket = 0; bucket < new; bucket++) { 2630 DYN_BUCKET_LOCK_INIT(bucket_lock, bucket); 2631 CK_SLIST_INIT(&ipv4[bucket]); 2632 CK_SLIST_INIT(&ipv4_parent[bucket]); 2633 #ifdef INET6 2634 CK_SLIST_INIT(&ipv6[bucket]); 2635 CK_SLIST_INIT(&ipv6_parent[bucket]); 2636 #endif 2637 } 2638 2639 #define DYN_RELINK_STATES(s, hval, i, head, ohead) do { \ 2640 while ((s = CK_SLIST_FIRST(&V_dyn_ ## ohead[i])) != NULL) { \ 2641 CK_SLIST_REMOVE_HEAD(&V_dyn_ ## ohead[i], entry); \ 2642 CK_SLIST_INSERT_HEAD(&head[DYN_BUCKET(s->hval, new)], \ 2643 s, entry); \ 2644 } \ 2645 } while (0) 2646 /* 2647 * Prevent rules changing from userland. 2648 */ 2649 IPFW_UH_WLOCK(chain); 2650 /* 2651 * Hold traffic processing until we finish resize to 2652 * prevent access to states lists. 2653 */ 2654 IPFW_WLOCK(chain); 2655 /* Re-link all dynamic states */ 2656 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { 2657 DYN_RELINK_STATES(s4, data->hashval, bucket, ipv4, ipv4); 2658 DYN_RELINK_STATES(s4, limit->hashval, bucket, ipv4_parent, 2659 ipv4_parent); 2660 #ifdef INET6 2661 DYN_RELINK_STATES(s6, data->hashval, bucket, ipv6, ipv6); 2662 DYN_RELINK_STATES(s6, limit->hashval, bucket, ipv6_parent, 2663 ipv6_parent); 2664 #endif 2665 } 2666 2667 #define DYN_SWAP_PTR(old, new, tmp) do { \ 2668 tmp = old; \ 2669 old = new; \ 2670 new = tmp; \ 2671 } while (0) 2672 /* Swap pointers */ 2673 DYN_SWAP_PTR(V_dyn_bucket_lock, bucket_lock, tmp); 2674 DYN_SWAP_PTR(V_dyn_ipv4, ipv4, tmp); 2675 DYN_SWAP_PTR(V_dyn_ipv4_parent, ipv4_parent, tmp); 2676 DYN_SWAP_PTR(V_dyn_ipv4_add, ipv4_add, tmp); 2677 DYN_SWAP_PTR(V_dyn_ipv4_parent_add, ipv4_parent_add, tmp); 2678 DYN_SWAP_PTR(V_dyn_ipv4_del, ipv4_del, tmp); 2679 DYN_SWAP_PTR(V_dyn_ipv4_parent_del, ipv4_parent_del, tmp); 2680 2681 #ifdef INET6 2682 DYN_SWAP_PTR(V_dyn_ipv6, ipv6, tmp); 2683 DYN_SWAP_PTR(V_dyn_ipv6_parent, ipv6_parent, tmp); 2684 DYN_SWAP_PTR(V_dyn_ipv6_add, ipv6_add, tmp); 2685 DYN_SWAP_PTR(V_dyn_ipv6_parent_add, ipv6_parent_add, tmp); 2686 DYN_SWAP_PTR(V_dyn_ipv6_del, ipv6_del, tmp); 2687 DYN_SWAP_PTR(V_dyn_ipv6_parent_del, ipv6_parent_del, tmp); 2688 #endif 2689 bucket = V_curr_dyn_buckets; 2690 V_curr_dyn_buckets = new; 2691 2692 IPFW_WUNLOCK(chain); 2693 IPFW_UH_WUNLOCK(chain); 2694 2695 /* Release old resources */ 2696 while (bucket-- != 0) 2697 DYN_BUCKET_LOCK_DESTROY(bucket_lock, bucket); 2698 free(bucket_lock, M_IPFW); 2699 free(ipv4, M_IPFW); 2700 free(ipv4_parent, M_IPFW); 2701 free(ipv4_add, M_IPFW); 2702 free(ipv4_parent_add, M_IPFW); 2703 free(ipv4_del, M_IPFW); 2704 free(ipv4_parent_del, M_IPFW); 2705 #ifdef INET6 2706 free(ipv6, M_IPFW); 2707 free(ipv6_parent, M_IPFW); 2708 free(ipv6_add, M_IPFW); 2709 free(ipv6_parent_add, M_IPFW); 2710 free(ipv6_del, M_IPFW); 2711 free(ipv6_parent_del, M_IPFW); 2712 #endif 2713 } 2714 2715 /* 2716 * This function is used to perform various maintenance 2717 * on dynamic hash lists. Currently it is called every second. 2718 */ 2719 static void 2720 dyn_tick(void *vnetx) 2721 { 2722 uint32_t buckets; 2723 2724 CURVNET_SET((struct vnet *)vnetx); 2725 /* 2726 * First free states unlinked in previous passes. 2727 */ 2728 dyn_free_states(&V_layer3_chain); 2729 /* 2730 * Now unlink others expired states. 2731 * We use IPFW_UH_WLOCK to avoid concurrent call of 2732 * dyn_expire_states(). It is the only function that does 2733 * deletion of state entries from states lists. 2734 */ 2735 IPFW_UH_WLOCK(&V_layer3_chain); 2736 dyn_expire_states(&V_layer3_chain, NULL); 2737 IPFW_UH_WUNLOCK(&V_layer3_chain); 2738 /* 2739 * Send keepalives if they are enabled and the time has come. 2740 */ 2741 if (V_dyn_keepalive != 0 && 2742 V_dyn_keepalive_last + V_dyn_keepalive_period <= time_uptime) { 2743 V_dyn_keepalive_last = time_uptime; 2744 dyn_send_keepalive_ipv4(&V_layer3_chain); 2745 #ifdef INET6 2746 dyn_send_keepalive_ipv6(&V_layer3_chain); 2747 #endif 2748 } 2749 /* 2750 * Check if we need to resize the hash: 2751 * if current number of states exceeds number of buckets in hash, 2752 * and dyn_buckets_max permits to grow the number of buckets, then 2753 * do it. Grow hash size to the minimum power of 2 which is bigger 2754 * than current states count. 2755 */ 2756 if (V_curr_dyn_buckets < V_dyn_buckets_max && 2757 (V_curr_dyn_buckets < V_dyn_count / 2 || ( 2758 V_curr_dyn_buckets < V_dyn_count && V_curr_max_length > 8))) { 2759 buckets = 1 << fls(V_dyn_count); 2760 if (buckets > V_dyn_buckets_max) 2761 buckets = V_dyn_buckets_max; 2762 dyn_grow_hashtable(&V_layer3_chain, buckets); 2763 } 2764 2765 callout_reset_on(&V_dyn_timeout, hz, dyn_tick, vnetx, 0); 2766 CURVNET_RESTORE(); 2767 } 2768 2769 void 2770 ipfw_expire_dyn_states(struct ip_fw_chain *chain, ipfw_range_tlv *rt) 2771 { 2772 /* 2773 * Do not perform any checks if we currently have no dynamic states 2774 */ 2775 if (V_dyn_count == 0) 2776 return; 2777 2778 IPFW_UH_WLOCK_ASSERT(chain); 2779 dyn_expire_states(chain, rt); 2780 } 2781 2782 /* 2783 * Pass through all states and reset eaction for orphaned rules. 2784 */ 2785 void 2786 ipfw_dyn_reset_eaction(struct ip_fw_chain *ch, uint16_t eaction_id, 2787 uint16_t default_id, uint16_t instance_id) 2788 { 2789 #ifdef INET6 2790 struct dyn_ipv6_state *s6; 2791 #endif 2792 struct dyn_ipv4_state *s4; 2793 struct ip_fw *rule; 2794 uint32_t bucket; 2795 2796 #define DYN_RESET_EACTION(s, h, b) \ 2797 CK_SLIST_FOREACH(s, &V_dyn_ ## h[b], entry) { \ 2798 if ((s->data->flags & DYN_REFERENCED) == 0) \ 2799 continue; \ 2800 rule = s->data->parent; \ 2801 if (s->type == O_LIMIT) \ 2802 rule = ((__typeof(s))rule)->limit->parent; \ 2803 ipfw_reset_eaction(ch, rule, eaction_id, \ 2804 default_id, instance_id); \ 2805 } 2806 2807 IPFW_UH_WLOCK_ASSERT(ch); 2808 if (V_dyn_count == 0) 2809 return; 2810 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { 2811 DYN_RESET_EACTION(s4, ipv4, bucket); 2812 #ifdef INET6 2813 DYN_RESET_EACTION(s6, ipv6, bucket); 2814 #endif 2815 } 2816 } 2817 2818 /* 2819 * Returns size of dynamic states in legacy format 2820 */ 2821 int 2822 ipfw_dyn_len(void) 2823 { 2824 2825 return ((V_dyn_count + V_dyn_parent_count) * sizeof(ipfw_dyn_rule)); 2826 } 2827 2828 /* 2829 * Returns number of dynamic states. 2830 * Marks every named object index used by dynamic states with bit in @bmask. 2831 * Returns number of named objects accounted in bmask via @nocnt. 2832 * Used by dump format v1 (current). 2833 */ 2834 uint32_t 2835 ipfw_dyn_get_count(uint32_t *bmask, int *nocnt) 2836 { 2837 #ifdef INET6 2838 struct dyn_ipv6_state *s6; 2839 #endif 2840 struct dyn_ipv4_state *s4; 2841 uint32_t bucket; 2842 2843 #define DYN_COUNT_OBJECTS(s, h, b) \ 2844 CK_SLIST_FOREACH(s, &V_dyn_ ## h[b], entry) { \ 2845 MPASS(s->kidx != 0); \ 2846 if (ipfw_mark_object_kidx(bmask, IPFW_TLV_STATE_NAME, \ 2847 s->kidx) != 0) \ 2848 (*nocnt)++; \ 2849 } 2850 2851 IPFW_UH_RLOCK_ASSERT(&V_layer3_chain); 2852 2853 /* No need to pass through all the buckets. */ 2854 *nocnt = 0; 2855 if (V_dyn_count + V_dyn_parent_count == 0) 2856 return (0); 2857 2858 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { 2859 DYN_COUNT_OBJECTS(s4, ipv4, bucket); 2860 #ifdef INET6 2861 DYN_COUNT_OBJECTS(s6, ipv6, bucket); 2862 #endif 2863 } 2864 2865 return (V_dyn_count + V_dyn_parent_count); 2866 } 2867 2868 /* 2869 * Check if rule contains at least one dynamic opcode. 2870 * 2871 * Returns 1 if such opcode is found, 0 otherwise. 2872 */ 2873 int 2874 ipfw_is_dyn_rule(struct ip_fw *rule) 2875 { 2876 int cmdlen, l; 2877 ipfw_insn *cmd; 2878 2879 l = rule->cmd_len; 2880 cmd = rule->cmd; 2881 cmdlen = 0; 2882 for ( ; l > 0 ; l -= cmdlen, cmd += cmdlen) { 2883 cmdlen = F_LEN(cmd); 2884 2885 switch (cmd->opcode) { 2886 case O_LIMIT: 2887 case O_KEEP_STATE: 2888 case O_PROBE_STATE: 2889 case O_CHECK_STATE: 2890 return (1); 2891 } 2892 } 2893 2894 return (0); 2895 } 2896 2897 static void 2898 dyn_export_parent(const struct dyn_parent *p, uint16_t kidx, uint8_t set, 2899 ipfw_dyn_rule *dst) 2900 { 2901 2902 dst->dyn_type = O_LIMIT_PARENT; 2903 dst->kidx = kidx; 2904 dst->count = (uint16_t)DPARENT_COUNT(p); 2905 dst->expire = TIME_LEQ(p->expire, time_uptime) ? 0: 2906 p->expire - time_uptime; 2907 2908 /* 'rule' is used to pass up the rule number and set */ 2909 memcpy(&dst->rule, &p->rulenum, sizeof(p->rulenum)); 2910 2911 /* store set number into high word of dst->rule pointer. */ 2912 memcpy((char *)&dst->rule + sizeof(p->rulenum), &set, sizeof(set)); 2913 2914 /* unused fields */ 2915 dst->pcnt = 0; 2916 dst->bcnt = 0; 2917 dst->parent = NULL; 2918 dst->state = 0; 2919 dst->ack_fwd = 0; 2920 dst->ack_rev = 0; 2921 dst->bucket = p->hashval; 2922 /* 2923 * The legacy userland code will interpret a NULL here as a marker 2924 * for the last dynamic rule. 2925 */ 2926 dst->next = (ipfw_dyn_rule *)1; 2927 } 2928 2929 static void 2930 dyn_export_data(const struct dyn_data *data, uint16_t kidx, uint8_t type, 2931 uint8_t set, ipfw_dyn_rule *dst) 2932 { 2933 2934 dst->dyn_type = type; 2935 dst->kidx = kidx; 2936 dst->pcnt = data->pcnt_fwd + data->pcnt_rev; 2937 dst->bcnt = data->bcnt_fwd + data->bcnt_rev; 2938 dst->expire = TIME_LEQ(data->expire, time_uptime) ? 0: 2939 data->expire - time_uptime; 2940 2941 /* 'rule' is used to pass up the rule number and set */ 2942 memcpy(&dst->rule, &data->rulenum, sizeof(data->rulenum)); 2943 2944 /* store set number into high word of dst->rule pointer. */ 2945 memcpy((char *)&dst->rule + sizeof(data->rulenum), &set, sizeof(set)); 2946 2947 dst->state = data->state; 2948 if (data->flags & DYN_REFERENCED) 2949 dst->state |= IPFW_DYN_ORPHANED; 2950 2951 /* unused fields */ 2952 dst->parent = NULL; 2953 dst->ack_fwd = data->ack_fwd; 2954 dst->ack_rev = data->ack_rev; 2955 dst->count = 0; 2956 dst->bucket = data->hashval; 2957 /* 2958 * The legacy userland code will interpret a NULL here as a marker 2959 * for the last dynamic rule. 2960 */ 2961 dst->next = (ipfw_dyn_rule *)1; 2962 } 2963 2964 static void 2965 dyn_export_ipv4_state(const struct dyn_ipv4_state *s, ipfw_dyn_rule *dst) 2966 { 2967 struct ip_fw *rule; 2968 2969 switch (s->type) { 2970 case O_LIMIT_PARENT: 2971 rule = s->limit->parent; 2972 dyn_export_parent(s->limit, s->kidx, rule->set, dst); 2973 break; 2974 default: 2975 rule = s->data->parent; 2976 if (s->type == O_LIMIT) 2977 rule = ((struct dyn_ipv4_state *)rule)->limit->parent; 2978 dyn_export_data(s->data, s->kidx, s->type, rule->set, dst); 2979 } 2980 2981 dst->id.dst_ip = s->dst; 2982 dst->id.src_ip = s->src; 2983 dst->id.dst_port = s->dport; 2984 dst->id.src_port = s->sport; 2985 dst->id.fib = s->data->fibnum; 2986 dst->id.proto = s->proto; 2987 dst->id._flags = 0; 2988 dst->id.addr_type = 4; 2989 2990 memset(&dst->id.dst_ip6, 0, sizeof(dst->id.dst_ip6)); 2991 memset(&dst->id.src_ip6, 0, sizeof(dst->id.src_ip6)); 2992 dst->id.flow_id6 = dst->id.extra = 0; 2993 } 2994 2995 #ifdef INET6 2996 static void 2997 dyn_export_ipv6_state(const struct dyn_ipv6_state *s, ipfw_dyn_rule *dst) 2998 { 2999 struct ip_fw *rule; 3000 3001 switch (s->type) { 3002 case O_LIMIT_PARENT: 3003 rule = s->limit->parent; 3004 dyn_export_parent(s->limit, s->kidx, rule->set, dst); 3005 break; 3006 default: 3007 rule = s->data->parent; 3008 if (s->type == O_LIMIT) 3009 rule = ((struct dyn_ipv6_state *)rule)->limit->parent; 3010 dyn_export_data(s->data, s->kidx, s->type, rule->set, dst); 3011 } 3012 3013 dst->id.src_ip6 = s->src; 3014 dst->id.dst_ip6 = s->dst; 3015 dst->id.dst_port = s->dport; 3016 dst->id.src_port = s->sport; 3017 dst->id.fib = s->data->fibnum; 3018 dst->id.proto = s->proto; 3019 dst->id._flags = 0; 3020 dst->id.addr_type = 6; 3021 3022 dst->id.dst_ip = dst->id.src_ip = 0; 3023 dst->id.flow_id6 = dst->id.extra = 0; 3024 } 3025 #endif /* INET6 */ 3026 3027 /* 3028 * Fills the buffer given by @sd with dynamic states. 3029 * Used by dump format v1 (current). 3030 * 3031 * Returns 0 on success. 3032 */ 3033 int 3034 ipfw_dump_states(struct ip_fw_chain *chain, struct sockopt_data *sd) 3035 { 3036 #ifdef INET6 3037 struct dyn_ipv6_state *s6; 3038 #endif 3039 struct dyn_ipv4_state *s4; 3040 ipfw_obj_dyntlv *dst, *last; 3041 ipfw_obj_ctlv *ctlv; 3042 uint32_t bucket; 3043 3044 if (V_dyn_count == 0) 3045 return (0); 3046 3047 /* 3048 * IPFW_UH_RLOCK garantees that another userland request 3049 * and callout thread will not delete entries from states 3050 * lists. 3051 */ 3052 IPFW_UH_RLOCK_ASSERT(chain); 3053 3054 ctlv = (ipfw_obj_ctlv *)ipfw_get_sopt_space(sd, sizeof(*ctlv)); 3055 if (ctlv == NULL) 3056 return (ENOMEM); 3057 ctlv->head.type = IPFW_TLV_DYNSTATE_LIST; 3058 ctlv->objsize = sizeof(ipfw_obj_dyntlv); 3059 last = NULL; 3060 3061 #define DYN_EXPORT_STATES(s, af, h, b) \ 3062 CK_SLIST_FOREACH(s, &V_dyn_ ## h[b], entry) { \ 3063 dst = (ipfw_obj_dyntlv *)ipfw_get_sopt_space(sd, \ 3064 sizeof(ipfw_obj_dyntlv)); \ 3065 if (dst == NULL) \ 3066 return (ENOMEM); \ 3067 dyn_export_ ## af ## _state(s, &dst->state); \ 3068 dst->head.length = sizeof(ipfw_obj_dyntlv); \ 3069 dst->head.type = IPFW_TLV_DYN_ENT; \ 3070 last = dst; \ 3071 } 3072 3073 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { 3074 DYN_EXPORT_STATES(s4, ipv4, ipv4_parent, bucket); 3075 DYN_EXPORT_STATES(s4, ipv4, ipv4, bucket); 3076 #ifdef INET6 3077 DYN_EXPORT_STATES(s6, ipv6, ipv6_parent, bucket); 3078 DYN_EXPORT_STATES(s6, ipv6, ipv6, bucket); 3079 #endif /* INET6 */ 3080 } 3081 3082 /* mark last dynamic rule */ 3083 if (last != NULL) 3084 last->head.flags = IPFW_DF_LAST; /* XXX: unused */ 3085 return (0); 3086 #undef DYN_EXPORT_STATES 3087 } 3088 3089 /* 3090 * Fill given buffer with dynamic states (legacy format). 3091 * IPFW_UH_RLOCK has to be held while calling. 3092 */ 3093 void 3094 ipfw_get_dynamic(struct ip_fw_chain *chain, char **pbp, const char *ep) 3095 { 3096 #ifdef INET6 3097 struct dyn_ipv6_state *s6; 3098 #endif 3099 struct dyn_ipv4_state *s4; 3100 ipfw_dyn_rule *p, *last = NULL; 3101 char *bp; 3102 uint32_t bucket; 3103 3104 if (V_dyn_count == 0) 3105 return; 3106 bp = *pbp; 3107 3108 IPFW_UH_RLOCK_ASSERT(chain); 3109 3110 #define DYN_EXPORT_STATES(s, af, head, b) \ 3111 CK_SLIST_FOREACH(s, &V_dyn_ ## head[b], entry) { \ 3112 if (bp + sizeof(*p) > ep) \ 3113 break; \ 3114 p = (ipfw_dyn_rule *)bp; \ 3115 dyn_export_ ## af ## _state(s, p); \ 3116 last = p; \ 3117 bp += sizeof(*p); \ 3118 } 3119 3120 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { 3121 DYN_EXPORT_STATES(s4, ipv4, ipv4_parent, bucket); 3122 DYN_EXPORT_STATES(s4, ipv4, ipv4, bucket); 3123 #ifdef INET6 3124 DYN_EXPORT_STATES(s6, ipv6, ipv6_parent, bucket); 3125 DYN_EXPORT_STATES(s6, ipv6, ipv6, bucket); 3126 #endif /* INET6 */ 3127 } 3128 3129 if (last != NULL) /* mark last dynamic rule */ 3130 last->next = NULL; 3131 *pbp = bp; 3132 #undef DYN_EXPORT_STATES 3133 } 3134 3135 void 3136 ipfw_dyn_init(struct ip_fw_chain *chain) 3137 { 3138 3139 #ifdef IPFIREWALL_JENKINSHASH 3140 V_dyn_hashseed = arc4random(); 3141 #endif 3142 V_dyn_max = 16384; /* max # of states */ 3143 V_dyn_parent_max = 4096; /* max # of parent states */ 3144 V_dyn_buckets_max = 8192; /* must be power of 2 */ 3145 3146 V_dyn_ack_lifetime = 300; 3147 V_dyn_syn_lifetime = 20; 3148 V_dyn_fin_lifetime = 1; 3149 V_dyn_rst_lifetime = 1; 3150 V_dyn_udp_lifetime = 10; 3151 V_dyn_short_lifetime = 5; 3152 3153 V_dyn_keepalive_interval = 20; 3154 V_dyn_keepalive_period = 5; 3155 V_dyn_keepalive = 1; /* send keepalives */ 3156 V_dyn_keepalive_last = time_uptime; 3157 3158 V_dyn_data_zone = uma_zcreate("IPFW dynamic states data", 3159 sizeof(struct dyn_data), NULL, NULL, NULL, NULL, 3160 UMA_ALIGN_PTR, 0); 3161 uma_zone_set_max(V_dyn_data_zone, V_dyn_max); 3162 3163 V_dyn_parent_zone = uma_zcreate("IPFW parent dynamic states", 3164 sizeof(struct dyn_parent), NULL, NULL, NULL, NULL, 3165 UMA_ALIGN_PTR, 0); 3166 uma_zone_set_max(V_dyn_parent_zone, V_dyn_parent_max); 3167 3168 SLIST_INIT(&V_dyn_expired_ipv4); 3169 V_dyn_ipv4 = NULL; 3170 V_dyn_ipv4_parent = NULL; 3171 V_dyn_ipv4_zone = uma_zcreate("IPFW IPv4 dynamic states", 3172 sizeof(struct dyn_ipv4_state), NULL, NULL, NULL, NULL, 3173 UMA_ALIGN_PTR, 0); 3174 3175 #ifdef INET6 3176 SLIST_INIT(&V_dyn_expired_ipv6); 3177 V_dyn_ipv6 = NULL; 3178 V_dyn_ipv6_parent = NULL; 3179 V_dyn_ipv6_zone = uma_zcreate("IPFW IPv6 dynamic states", 3180 sizeof(struct dyn_ipv6_state), NULL, NULL, NULL, NULL, 3181 UMA_ALIGN_PTR, 0); 3182 #endif 3183 3184 /* Initialize buckets. */ 3185 V_curr_dyn_buckets = 0; 3186 V_dyn_bucket_lock = NULL; 3187 dyn_grow_hashtable(chain, 256); 3188 3189 if (IS_DEFAULT_VNET(curvnet)) 3190 dyn_hp_cache = malloc(mp_ncpus * sizeof(void *), M_IPFW, 3191 M_WAITOK | M_ZERO); 3192 3193 DYN_EXPIRED_LOCK_INIT(); 3194 callout_init(&V_dyn_timeout, 1); 3195 callout_reset(&V_dyn_timeout, hz, dyn_tick, curvnet); 3196 IPFW_ADD_OBJ_REWRITER(IS_DEFAULT_VNET(curvnet), dyn_opcodes); 3197 } 3198 3199 void 3200 ipfw_dyn_uninit(int pass) 3201 { 3202 #ifdef INET6 3203 struct dyn_ipv6_state *s6; 3204 #endif 3205 struct dyn_ipv4_state *s4; 3206 int bucket; 3207 3208 if (pass == 0) { 3209 callout_drain(&V_dyn_timeout); 3210 return; 3211 } 3212 IPFW_DEL_OBJ_REWRITER(IS_DEFAULT_VNET(curvnet), dyn_opcodes); 3213 DYN_EXPIRED_LOCK_DESTROY(); 3214 3215 #define DYN_FREE_STATES_FORCED(CK, s, af, name, en) do { \ 3216 while ((s = CK ## SLIST_FIRST(&V_dyn_ ## name)) != NULL) { \ 3217 CK ## SLIST_REMOVE_HEAD(&V_dyn_ ## name, en); \ 3218 if (s->type == O_LIMIT_PARENT) \ 3219 uma_zfree(V_dyn_parent_zone, s->limit); \ 3220 else \ 3221 uma_zfree(V_dyn_data_zone, s->data); \ 3222 uma_zfree(V_dyn_ ## af ## _zone, s); \ 3223 } \ 3224 } while (0) 3225 for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { 3226 DYN_BUCKET_LOCK_DESTROY(V_dyn_bucket_lock, bucket); 3227 3228 DYN_FREE_STATES_FORCED(CK_, s4, ipv4, ipv4[bucket], entry); 3229 DYN_FREE_STATES_FORCED(CK_, s4, ipv4, ipv4_parent[bucket], 3230 entry); 3231 #ifdef INET6 3232 DYN_FREE_STATES_FORCED(CK_, s6, ipv6, ipv6[bucket], entry); 3233 DYN_FREE_STATES_FORCED(CK_, s6, ipv6, ipv6_parent[bucket], 3234 entry); 3235 #endif /* INET6 */ 3236 } 3237 DYN_FREE_STATES_FORCED(, s4, ipv4, expired_ipv4, expired); 3238 #ifdef INET6 3239 DYN_FREE_STATES_FORCED(, s6, ipv6, expired_ipv6, expired); 3240 #endif 3241 #undef DYN_FREE_STATES_FORCED 3242 3243 uma_zdestroy(V_dyn_ipv4_zone); 3244 uma_zdestroy(V_dyn_data_zone); 3245 uma_zdestroy(V_dyn_parent_zone); 3246 #ifdef INET6 3247 uma_zdestroy(V_dyn_ipv6_zone); 3248 free(V_dyn_ipv6, M_IPFW); 3249 free(V_dyn_ipv6_parent, M_IPFW); 3250 free(V_dyn_ipv6_add, M_IPFW); 3251 free(V_dyn_ipv6_parent_add, M_IPFW); 3252 free(V_dyn_ipv6_del, M_IPFW); 3253 free(V_dyn_ipv6_parent_del, M_IPFW); 3254 #endif 3255 free(V_dyn_bucket_lock, M_IPFW); 3256 free(V_dyn_ipv4, M_IPFW); 3257 free(V_dyn_ipv4_parent, M_IPFW); 3258 free(V_dyn_ipv4_add, M_IPFW); 3259 free(V_dyn_ipv4_parent_add, M_IPFW); 3260 free(V_dyn_ipv4_del, M_IPFW); 3261 free(V_dyn_ipv4_parent_del, M_IPFW); 3262 if (IS_DEFAULT_VNET(curvnet)) 3263 free(dyn_hp_cache, M_IPFW); 3264 } 3265 3266 3267