1 /* $OpenBSD: pf.c,v 1.1116 2021/04/27 09:38:29 sashan Exp $ */ 2 3 /* 4 * Copyright (c) 2001 Daniel Hartmeier 5 * Copyright (c) 2002 - 2013 Henning Brauer <henning@openbsd.org> 6 * All rights reserved. 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 * 12 * - Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * - Redistributions in binary form must reproduce the above 15 * copyright notice, this list of conditions and the following 16 * disclaimer in the documentation and/or other materials provided 17 * with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 22 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 23 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 25 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 26 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 27 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 29 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 * 32 * Effort sponsored in part by the Defense Advanced Research Projects 33 * Agency (DARPA) and Air Force Research Laboratory, Air Force 34 * Materiel Command, USAF, under agreement number F30602-01-2-0537. 35 * 36 */ 37 38 #include "bpfilter.h" 39 #include "carp.h" 40 #include "pflog.h" 41 #include "pfsync.h" 42 #include "pflow.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/mbuf.h> 47 #include <sys/filio.h> 48 #include <sys/socket.h> 49 #include <sys/socketvar.h> 50 #include <sys/kernel.h> 51 #include <sys/time.h> 52 #include <sys/pool.h> 53 #include <sys/proc.h> 54 #include <sys/rwlock.h> 55 #include <sys/syslog.h> 56 57 #include <crypto/sha2.h> 58 59 #include <net/if.h> 60 #include <net/if_var.h> 61 #include <net/if_types.h> 62 #include <net/route.h> 63 64 #include <netinet/in.h> 65 #include <netinet/in_var.h> 66 #include <netinet/ip.h> 67 #include <netinet/in_pcb.h> 68 #include <netinet/ip_var.h> 69 #include <netinet/ip_icmp.h> 70 #include <netinet/icmp_var.h> 71 #include <netinet/tcp.h> 72 #include <netinet/tcp_seq.h> 73 #include <netinet/tcp_timer.h> 74 #include <netinet/tcp_var.h> 75 #include <netinet/tcp_fsm.h> 76 #include <netinet/udp.h> 77 #include <netinet/udp_var.h> 78 #include <netinet/ip_divert.h> 79 80 #ifdef INET6 81 #include <netinet6/in6_var.h> 82 #include <netinet/ip6.h> 83 #include <netinet6/ip6_var.h> 84 #include <netinet/icmp6.h> 85 #include <netinet6/nd6.h> 86 #include <netinet6/ip6_divert.h> 87 #endif /* INET6 */ 88 89 #include <net/pfvar.h> 90 #include <net/pfvar_priv.h> 91 92 #if NPFLOG > 0 93 #include <net/if_pflog.h> 94 #endif /* NPFLOG > 0 */ 95 96 #if NPFLOW > 0 97 #include <net/if_pflow.h> 98 #endif /* NPFLOW > 0 */ 99 100 #if NPFSYNC > 0 101 #include <net/if_pfsync.h> 102 #endif /* NPFSYNC > 0 */ 103 104 #ifdef DDB 105 #include <machine/db_machdep.h> 106 #include <ddb/db_interface.h> 107 #endif 108 109 /* 110 * Global variables 111 */ 112 struct pf_state_tree pf_statetbl; 113 struct pf_queuehead pf_queues[2]; 114 struct pf_queuehead *pf_queues_active; 115 struct pf_queuehead *pf_queues_inactive; 116 117 struct pf_status pf_status; 118 119 int pf_hdr_limit = 20; /* arbitrary limit, tune in ddb */ 120 121 SHA2_CTX pf_tcp_secret_ctx; 122 u_char pf_tcp_secret[16]; 123 int pf_tcp_secret_init; 124 int pf_tcp_iss_off; 125 126 int pf_npurge; 127 struct task pf_purge_task = TASK_INITIALIZER(pf_purge, &pf_npurge); 128 struct timeout pf_purge_to = TIMEOUT_INITIALIZER(pf_purge_timeout, NULL); 129 130 enum pf_test_status { 131 PF_TEST_FAIL = -1, 132 PF_TEST_OK, 133 PF_TEST_QUICK 134 }; 135 136 struct pf_test_ctx { 137 enum pf_test_status test_status; 138 struct pf_pdesc *pd; 139 struct pf_rule_actions act; 140 u_int8_t icmpcode; 141 u_int8_t icmptype; 142 int icmp_dir; 143 int state_icmp; 144 int tag; 145 u_short reason; 146 struct pf_rule_item *ri; 147 struct pf_src_node *sns[PF_SN_MAX]; 148 struct pf_rule_slist rules; 149 struct pf_rule *nr; 150 struct pf_rule **rm; 151 struct pf_rule *a; 152 struct pf_rule **am; 153 struct pf_ruleset **rsm; 154 struct pf_ruleset *arsm; 155 struct pf_ruleset *aruleset; 156 struct tcphdr *th; 157 int depth; 158 }; 159 160 #define PF_ANCHOR_STACK_MAX 64 161 162 struct pool pf_src_tree_pl, pf_rule_pl, pf_queue_pl; 163 struct pool pf_state_pl, pf_state_key_pl, pf_state_item_pl; 164 struct pool pf_rule_item_pl, pf_sn_item_pl, pf_pktdelay_pl; 165 166 void pf_add_threshold(struct pf_threshold *); 167 int pf_check_threshold(struct pf_threshold *); 168 int pf_check_tcp_cksum(struct mbuf *, int, int, 169 sa_family_t); 170 static __inline void pf_cksum_fixup(u_int16_t *, u_int16_t, u_int16_t, 171 u_int8_t); 172 void pf_cksum_fixup_a(u_int16_t *, const struct pf_addr *, 173 const struct pf_addr *, sa_family_t, u_int8_t); 174 int pf_modulate_sack(struct pf_pdesc *, 175 struct pf_state_peer *); 176 int pf_icmp_mapping(struct pf_pdesc *, u_int8_t, int *, 177 u_int16_t *, u_int16_t *); 178 int pf_change_icmp_af(struct mbuf *, int, 179 struct pf_pdesc *, struct pf_pdesc *, 180 struct pf_addr *, struct pf_addr *, sa_family_t, 181 sa_family_t); 182 int pf_translate_a(struct pf_pdesc *, struct pf_addr *, 183 struct pf_addr *); 184 void pf_translate_icmp(struct pf_pdesc *, struct pf_addr *, 185 u_int16_t *, struct pf_addr *, struct pf_addr *, 186 u_int16_t); 187 int pf_translate_icmp_af(struct pf_pdesc*, int, void *); 188 void pf_send_icmp(struct mbuf *, u_int8_t, u_int8_t, int, 189 sa_family_t, struct pf_rule *, u_int); 190 void pf_detach_state(struct pf_state *); 191 void pf_state_key_detach(struct pf_state *, int); 192 u_int32_t pf_tcp_iss(struct pf_pdesc *); 193 void pf_rule_to_actions(struct pf_rule *, 194 struct pf_rule_actions *); 195 int pf_test_rule(struct pf_pdesc *, struct pf_rule **, 196 struct pf_state **, struct pf_rule **, 197 struct pf_ruleset **, u_short *); 198 static __inline int pf_create_state(struct pf_pdesc *, struct pf_rule *, 199 struct pf_rule *, struct pf_rule *, 200 struct pf_state_key **, struct pf_state_key **, 201 int *, struct pf_state **, int, 202 struct pf_rule_slist *, struct pf_rule_actions *, 203 struct pf_src_node *[]); 204 static __inline int pf_state_key_addr_setup(struct pf_pdesc *, void *, 205 int, struct pf_addr *, int, struct pf_addr *, 206 int, int); 207 int pf_state_key_setup(struct pf_pdesc *, struct 208 pf_state_key **, struct pf_state_key **, int); 209 int pf_tcp_track_full(struct pf_pdesc *, 210 struct pf_state **, u_short *, int *, int); 211 int pf_tcp_track_sloppy(struct pf_pdesc *, 212 struct pf_state **, u_short *); 213 static __inline int pf_synproxy(struct pf_pdesc *, struct pf_state **, 214 u_short *); 215 int pf_test_state(struct pf_pdesc *, struct pf_state **, 216 u_short *, int); 217 int pf_icmp_state_lookup(struct pf_pdesc *, 218 struct pf_state_key_cmp *, struct pf_state **, 219 u_int16_t, u_int16_t, int, int *, int, int); 220 int pf_test_state_icmp(struct pf_pdesc *, 221 struct pf_state **, u_short *); 222 u_int16_t pf_calc_mss(struct pf_addr *, sa_family_t, int, 223 u_int16_t); 224 static __inline int pf_set_rt_ifp(struct pf_state *, struct pf_addr *, 225 sa_family_t, struct pf_src_node **); 226 struct pf_divert *pf_get_divert(struct mbuf *); 227 int pf_walk_header(struct pf_pdesc *, struct ip *, 228 u_short *); 229 int pf_walk_option6(struct pf_pdesc *, struct ip6_hdr *, 230 int, int, u_short *); 231 int pf_walk_header6(struct pf_pdesc *, struct ip6_hdr *, 232 u_short *); 233 void pf_print_state_parts(struct pf_state *, 234 struct pf_state_key *, struct pf_state_key *); 235 int pf_addr_wrap_neq(struct pf_addr_wrap *, 236 struct pf_addr_wrap *); 237 int pf_compare_state_keys(struct pf_state_key *, 238 struct pf_state_key *, struct pfi_kif *, u_int); 239 int pf_find_state(struct pf_pdesc *, 240 struct pf_state_key_cmp *, struct pf_state **); 241 int pf_src_connlimit(struct pf_state **); 242 int pf_match_rcvif(struct mbuf *, struct pf_rule *); 243 int pf_step_into_anchor(struct pf_test_ctx *, 244 struct pf_rule *); 245 int pf_match_rule(struct pf_test_ctx *, 246 struct pf_ruleset *); 247 void pf_counters_inc(int, struct pf_pdesc *, 248 struct pf_state *, struct pf_rule *, 249 struct pf_rule *); 250 251 int pf_state_key_isvalid(struct pf_state_key *); 252 struct pf_state_key *pf_state_key_ref(struct pf_state_key *); 253 void pf_state_key_unref(struct pf_state_key *); 254 void pf_state_key_link_reverse(struct pf_state_key *, 255 struct pf_state_key *); 256 void pf_state_key_unlink_reverse(struct pf_state_key *); 257 void pf_state_key_link_inpcb(struct pf_state_key *, 258 struct inpcb *); 259 void pf_state_key_unlink_inpcb(struct pf_state_key *); 260 void pf_inpcb_unlink_state_key(struct inpcb *); 261 void pf_pktenqueue_delayed(void *); 262 263 #if NPFLOG > 0 264 void pf_log_matches(struct pf_pdesc *, struct pf_rule *, 265 struct pf_rule *, struct pf_ruleset *, 266 struct pf_rule_slist *); 267 #endif /* NPFLOG > 0 */ 268 269 extern struct pool pfr_ktable_pl; 270 extern struct pool pfr_kentry_pl; 271 272 struct pf_pool_limit pf_pool_limits[PF_LIMIT_MAX] = { 273 { &pf_state_pl, PFSTATE_HIWAT, PFSTATE_HIWAT }, 274 { &pf_src_tree_pl, PFSNODE_HIWAT, PFSNODE_HIWAT }, 275 { &pf_frent_pl, PFFRAG_FRENT_HIWAT, PFFRAG_FRENT_HIWAT }, 276 { &pfr_ktable_pl, PFR_KTABLE_HIWAT, PFR_KTABLE_HIWAT }, 277 { &pfr_kentry_pl, PFR_KENTRY_HIWAT, PFR_KENTRY_HIWAT }, 278 { &pf_pktdelay_pl, PF_PKTDELAY_MAXPKTS, PF_PKTDELAY_MAXPKTS } 279 }; 280 281 #define BOUND_IFACE(r, k) \ 282 ((r)->rule_flag & PFRULE_IFBOUND) ? (k) : pfi_all 283 284 #define STATE_INC_COUNTERS(s) \ 285 do { \ 286 struct pf_rule_item *mrm; \ 287 s->rule.ptr->states_cur++; \ 288 s->rule.ptr->states_tot++; \ 289 if (s->anchor.ptr != NULL) { \ 290 s->anchor.ptr->states_cur++; \ 291 s->anchor.ptr->states_tot++; \ 292 } \ 293 SLIST_FOREACH(mrm, &s->match_rules, entry) \ 294 mrm->r->states_cur++; \ 295 } while (0) 296 297 static __inline int pf_src_compare(struct pf_src_node *, struct pf_src_node *); 298 static __inline int pf_state_compare_key(struct pf_state_key *, 299 struct pf_state_key *); 300 static __inline int pf_state_compare_id(struct pf_state *, 301 struct pf_state *); 302 #ifdef INET6 303 static __inline void pf_cksum_uncover(u_int16_t *, u_int16_t, u_int8_t); 304 static __inline void pf_cksum_cover(u_int16_t *, u_int16_t, u_int8_t); 305 #endif /* INET6 */ 306 static __inline void pf_set_protostate(struct pf_state *, int, u_int8_t); 307 308 struct pf_src_tree tree_src_tracking; 309 310 struct pf_state_tree_id tree_id; 311 struct pf_state_queue state_list; 312 313 RB_GENERATE(pf_src_tree, pf_src_node, entry, pf_src_compare); 314 RB_GENERATE(pf_state_tree, pf_state_key, entry, pf_state_compare_key); 315 RB_GENERATE(pf_state_tree_id, pf_state, 316 entry_id, pf_state_compare_id); 317 318 SLIST_HEAD(pf_rule_gcl, pf_rule) pf_rule_gcl = 319 SLIST_HEAD_INITIALIZER(pf_rule_gcl); 320 321 __inline int 322 pf_addr_compare(struct pf_addr *a, struct pf_addr *b, sa_family_t af) 323 { 324 switch (af) { 325 case AF_INET: 326 if (a->addr32[0] > b->addr32[0]) 327 return (1); 328 if (a->addr32[0] < b->addr32[0]) 329 return (-1); 330 break; 331 #ifdef INET6 332 case AF_INET6: 333 if (a->addr32[3] > b->addr32[3]) 334 return (1); 335 if (a->addr32[3] < b->addr32[3]) 336 return (-1); 337 if (a->addr32[2] > b->addr32[2]) 338 return (1); 339 if (a->addr32[2] < b->addr32[2]) 340 return (-1); 341 if (a->addr32[1] > b->addr32[1]) 342 return (1); 343 if (a->addr32[1] < b->addr32[1]) 344 return (-1); 345 if (a->addr32[0] > b->addr32[0]) 346 return (1); 347 if (a->addr32[0] < b->addr32[0]) 348 return (-1); 349 break; 350 #endif /* INET6 */ 351 } 352 return (0); 353 } 354 355 static __inline int 356 pf_src_compare(struct pf_src_node *a, struct pf_src_node *b) 357 { 358 int diff; 359 360 if (a->rule.ptr > b->rule.ptr) 361 return (1); 362 if (a->rule.ptr < b->rule.ptr) 363 return (-1); 364 if ((diff = a->type - b->type) != 0) 365 return (diff); 366 if ((diff = a->af - b->af) != 0) 367 return (diff); 368 if ((diff = pf_addr_compare(&a->addr, &b->addr, a->af)) != 0) 369 return (diff); 370 return (0); 371 } 372 373 static __inline void 374 pf_set_protostate(struct pf_state *s, int which, u_int8_t newstate) 375 { 376 if (which == PF_PEER_DST || which == PF_PEER_BOTH) 377 s->dst.state = newstate; 378 if (which == PF_PEER_DST) 379 return; 380 381 if (s->src.state == newstate) 382 return; 383 if (s->creatorid == pf_status.hostid && s->key[PF_SK_STACK] != NULL && 384 s->key[PF_SK_STACK]->proto == IPPROTO_TCP && 385 !(TCPS_HAVEESTABLISHED(s->src.state) || 386 s->src.state == TCPS_CLOSED) && 387 (TCPS_HAVEESTABLISHED(newstate) || newstate == TCPS_CLOSED)) 388 pf_status.states_halfopen--; 389 390 s->src.state = newstate; 391 } 392 393 void 394 pf_addrcpy(struct pf_addr *dst, struct pf_addr *src, sa_family_t af) 395 { 396 switch (af) { 397 case AF_INET: 398 dst->addr32[0] = src->addr32[0]; 399 break; 400 #ifdef INET6 401 case AF_INET6: 402 dst->addr32[0] = src->addr32[0]; 403 dst->addr32[1] = src->addr32[1]; 404 dst->addr32[2] = src->addr32[2]; 405 dst->addr32[3] = src->addr32[3]; 406 break; 407 #endif /* INET6 */ 408 default: 409 unhandled_af(af); 410 } 411 } 412 413 void 414 pf_init_threshold(struct pf_threshold *threshold, 415 u_int32_t limit, u_int32_t seconds) 416 { 417 threshold->limit = limit * PF_THRESHOLD_MULT; 418 threshold->seconds = seconds; 419 threshold->count = 0; 420 threshold->last = getuptime(); 421 } 422 423 void 424 pf_add_threshold(struct pf_threshold *threshold) 425 { 426 u_int32_t t = getuptime(), diff = t - threshold->last; 427 428 if (diff >= threshold->seconds) 429 threshold->count = 0; 430 else 431 threshold->count -= threshold->count * diff / 432 threshold->seconds; 433 threshold->count += PF_THRESHOLD_MULT; 434 threshold->last = t; 435 } 436 437 int 438 pf_check_threshold(struct pf_threshold *threshold) 439 { 440 return (threshold->count > threshold->limit); 441 } 442 443 int 444 pf_src_connlimit(struct pf_state **state) 445 { 446 int bad = 0; 447 struct pf_src_node *sn; 448 449 if ((sn = pf_get_src_node((*state), PF_SN_NONE)) == NULL) 450 return (0); 451 452 sn->conn++; 453 (*state)->src.tcp_est = 1; 454 pf_add_threshold(&sn->conn_rate); 455 456 if ((*state)->rule.ptr->max_src_conn && 457 (*state)->rule.ptr->max_src_conn < sn->conn) { 458 pf_status.lcounters[LCNT_SRCCONN]++; 459 bad++; 460 } 461 462 if ((*state)->rule.ptr->max_src_conn_rate.limit && 463 pf_check_threshold(&sn->conn_rate)) { 464 pf_status.lcounters[LCNT_SRCCONNRATE]++; 465 bad++; 466 } 467 468 if (!bad) 469 return (0); 470 471 if ((*state)->rule.ptr->overload_tbl) { 472 struct pfr_addr p; 473 u_int32_t killed = 0; 474 475 pf_status.lcounters[LCNT_OVERLOAD_TABLE]++; 476 if (pf_status.debug >= LOG_NOTICE) { 477 log(LOG_NOTICE, 478 "pf: pf_src_connlimit: blocking address "); 479 pf_print_host(&sn->addr, 0, 480 (*state)->key[PF_SK_WIRE]->af); 481 } 482 483 memset(&p, 0, sizeof(p)); 484 p.pfra_af = (*state)->key[PF_SK_WIRE]->af; 485 switch ((*state)->key[PF_SK_WIRE]->af) { 486 case AF_INET: 487 p.pfra_net = 32; 488 p.pfra_ip4addr = sn->addr.v4; 489 break; 490 #ifdef INET6 491 case AF_INET6: 492 p.pfra_net = 128; 493 p.pfra_ip6addr = sn->addr.v6; 494 break; 495 #endif /* INET6 */ 496 } 497 498 pfr_insert_kentry((*state)->rule.ptr->overload_tbl, 499 &p, gettime()); 500 501 /* kill existing states if that's required. */ 502 if ((*state)->rule.ptr->flush) { 503 struct pf_state_key *sk; 504 struct pf_state *st; 505 506 pf_status.lcounters[LCNT_OVERLOAD_FLUSH]++; 507 RB_FOREACH(st, pf_state_tree_id, &tree_id) { 508 sk = st->key[PF_SK_WIRE]; 509 /* 510 * Kill states from this source. (Only those 511 * from the same rule if PF_FLUSH_GLOBAL is not 512 * set) 513 */ 514 if (sk->af == 515 (*state)->key[PF_SK_WIRE]->af && 516 (((*state)->direction == PF_OUT && 517 PF_AEQ(&sn->addr, &sk->addr[1], sk->af)) || 518 ((*state)->direction == PF_IN && 519 PF_AEQ(&sn->addr, &sk->addr[0], sk->af))) && 520 ((*state)->rule.ptr->flush & 521 PF_FLUSH_GLOBAL || 522 (*state)->rule.ptr == st->rule.ptr)) { 523 st->timeout = PFTM_PURGE; 524 pf_set_protostate(st, PF_PEER_BOTH, 525 TCPS_CLOSED); 526 killed++; 527 } 528 } 529 if (pf_status.debug >= LOG_NOTICE) 530 addlog(", %u states killed", killed); 531 } 532 if (pf_status.debug >= LOG_NOTICE) 533 addlog("\n"); 534 } 535 536 /* kill this state */ 537 (*state)->timeout = PFTM_PURGE; 538 pf_set_protostate(*state, PF_PEER_BOTH, TCPS_CLOSED); 539 return (1); 540 } 541 542 int 543 pf_insert_src_node(struct pf_src_node **sn, struct pf_rule *rule, 544 enum pf_sn_types type, sa_family_t af, struct pf_addr *src, 545 struct pf_addr *raddr, struct pfi_kif *kif) 546 { 547 struct pf_src_node k; 548 549 if (*sn == NULL) { 550 k.af = af; 551 k.type = type; 552 pf_addrcpy(&k.addr, src, af); 553 k.rule.ptr = rule; 554 pf_status.scounters[SCNT_SRC_NODE_SEARCH]++; 555 *sn = RB_FIND(pf_src_tree, &tree_src_tracking, &k); 556 } 557 if (*sn == NULL) { 558 if (!rule->max_src_nodes || 559 rule->src_nodes < rule->max_src_nodes) 560 (*sn) = pool_get(&pf_src_tree_pl, PR_NOWAIT | PR_ZERO); 561 else 562 pf_status.lcounters[LCNT_SRCNODES]++; 563 if ((*sn) == NULL) 564 return (-1); 565 566 pf_init_threshold(&(*sn)->conn_rate, 567 rule->max_src_conn_rate.limit, 568 rule->max_src_conn_rate.seconds); 569 570 (*sn)->type = type; 571 (*sn)->af = af; 572 (*sn)->rule.ptr = rule; 573 pf_addrcpy(&(*sn)->addr, src, af); 574 if (raddr) 575 pf_addrcpy(&(*sn)->raddr, raddr, af); 576 if (RB_INSERT(pf_src_tree, 577 &tree_src_tracking, *sn) != NULL) { 578 if (pf_status.debug >= LOG_NOTICE) { 579 log(LOG_NOTICE, 580 "pf: src_tree insert failed: "); 581 pf_print_host(&(*sn)->addr, 0, af); 582 addlog("\n"); 583 } 584 pool_put(&pf_src_tree_pl, *sn); 585 return (-1); 586 } 587 (*sn)->creation = getuptime(); 588 (*sn)->rule.ptr->src_nodes++; 589 if (kif != NULL) { 590 (*sn)->kif = kif; 591 pfi_kif_ref(kif, PFI_KIF_REF_SRCNODE); 592 } 593 pf_status.scounters[SCNT_SRC_NODE_INSERT]++; 594 pf_status.src_nodes++; 595 } else { 596 if (rule->max_src_states && 597 (*sn)->states >= rule->max_src_states) { 598 pf_status.lcounters[LCNT_SRCSTATES]++; 599 return (-1); 600 } 601 } 602 return (0); 603 } 604 605 void 606 pf_remove_src_node(struct pf_src_node *sn) 607 { 608 if (sn->states > 0 || sn->expire > getuptime()) 609 return; 610 611 sn->rule.ptr->src_nodes--; 612 if (sn->rule.ptr->states_cur == 0 && 613 sn->rule.ptr->src_nodes == 0) 614 pf_rm_rule(NULL, sn->rule.ptr); 615 RB_REMOVE(pf_src_tree, &tree_src_tracking, sn); 616 pf_status.scounters[SCNT_SRC_NODE_REMOVALS]++; 617 pf_status.src_nodes--; 618 pfi_kif_unref(sn->kif, PFI_KIF_REF_SRCNODE); 619 pool_put(&pf_src_tree_pl, sn); 620 } 621 622 struct pf_src_node * 623 pf_get_src_node(struct pf_state *s, enum pf_sn_types type) 624 { 625 struct pf_sn_item *sni; 626 627 SLIST_FOREACH(sni, &s->src_nodes, next) 628 if (sni->sn->type == type) 629 return (sni->sn); 630 return (NULL); 631 } 632 633 void 634 pf_state_rm_src_node(struct pf_state *s, struct pf_src_node *sn) 635 { 636 struct pf_sn_item *sni, *snin, *snip = NULL; 637 638 for (sni = SLIST_FIRST(&s->src_nodes); sni; sni = snin) { 639 snin = SLIST_NEXT(sni, next); 640 if (sni->sn == sn) { 641 if (snip) 642 SLIST_REMOVE_AFTER(snip, next); 643 else 644 SLIST_REMOVE_HEAD(&s->src_nodes, next); 645 pool_put(&pf_sn_item_pl, sni); 646 sni = NULL; 647 sn->states--; 648 } 649 if (sni != NULL) 650 snip = sni; 651 } 652 } 653 654 /* state table stuff */ 655 656 static __inline int 657 pf_state_compare_key(struct pf_state_key *a, struct pf_state_key *b) 658 { 659 int diff; 660 661 if ((diff = a->proto - b->proto) != 0) 662 return (diff); 663 if ((diff = a->af - b->af) != 0) 664 return (diff); 665 if ((diff = pf_addr_compare(&a->addr[0], &b->addr[0], a->af)) != 0) 666 return (diff); 667 if ((diff = pf_addr_compare(&a->addr[1], &b->addr[1], a->af)) != 0) 668 return (diff); 669 if ((diff = a->port[0] - b->port[0]) != 0) 670 return (diff); 671 if ((diff = a->port[1] - b->port[1]) != 0) 672 return (diff); 673 if ((diff = a->rdomain - b->rdomain) != 0) 674 return (diff); 675 return (0); 676 } 677 678 static __inline int 679 pf_state_compare_id(struct pf_state *a, struct pf_state *b) 680 { 681 if (a->id > b->id) 682 return (1); 683 if (a->id < b->id) 684 return (-1); 685 if (a->creatorid > b->creatorid) 686 return (1); 687 if (a->creatorid < b->creatorid) 688 return (-1); 689 690 return (0); 691 } 692 693 int 694 pf_state_key_attach(struct pf_state_key *sk, struct pf_state *s, int idx) 695 { 696 struct pf_state_item *si; 697 struct pf_state_key *cur; 698 struct pf_state *olds = NULL; 699 700 KASSERT(s->key[idx] == NULL); 701 if ((cur = RB_INSERT(pf_state_tree, &pf_statetbl, sk)) != NULL) { 702 /* key exists. check for same kif, if none, add to key */ 703 TAILQ_FOREACH(si, &cur->states, entry) 704 if (si->s->kif == s->kif && 705 ((si->s->key[PF_SK_WIRE]->af == sk->af && 706 si->s->direction == s->direction) || 707 (si->s->key[PF_SK_WIRE]->af != 708 si->s->key[PF_SK_STACK]->af && 709 sk->af == si->s->key[PF_SK_STACK]->af && 710 si->s->direction != s->direction))) { 711 int reuse = 0; 712 713 if (sk->proto == IPPROTO_TCP && 714 si->s->src.state >= TCPS_FIN_WAIT_2 && 715 si->s->dst.state >= TCPS_FIN_WAIT_2) 716 reuse = 1; 717 if (pf_status.debug >= LOG_NOTICE) { 718 log(LOG_NOTICE, 719 "pf: %s key attach %s on %s: ", 720 (idx == PF_SK_WIRE) ? 721 "wire" : "stack", 722 reuse ? "reuse" : "failed", 723 s->kif->pfik_name); 724 pf_print_state_parts(s, 725 (idx == PF_SK_WIRE) ? sk : NULL, 726 (idx == PF_SK_STACK) ? sk : NULL); 727 addlog(", existing: "); 728 pf_print_state_parts(si->s, 729 (idx == PF_SK_WIRE) ? sk : NULL, 730 (idx == PF_SK_STACK) ? sk : NULL); 731 addlog("\n"); 732 } 733 if (reuse) { 734 pf_set_protostate(si->s, PF_PEER_BOTH, 735 TCPS_CLOSED); 736 /* remove late or sks can go away */ 737 olds = si->s; 738 } else { 739 pool_put(&pf_state_key_pl, sk); 740 return (-1); /* collision! */ 741 } 742 } 743 pool_put(&pf_state_key_pl, sk); 744 s->key[idx] = cur; 745 } else 746 s->key[idx] = sk; 747 748 if ((si = pool_get(&pf_state_item_pl, PR_NOWAIT)) == NULL) { 749 pf_state_key_detach(s, idx); 750 return (-1); 751 } 752 si->s = s; 753 754 /* list is sorted, if-bound states before floating */ 755 if (s->kif == pfi_all) 756 TAILQ_INSERT_TAIL(&s->key[idx]->states, si, entry); 757 else 758 TAILQ_INSERT_HEAD(&s->key[idx]->states, si, entry); 759 760 if (olds) 761 pf_remove_state(olds); 762 763 return (0); 764 } 765 766 void 767 pf_detach_state(struct pf_state *s) 768 { 769 if (s->key[PF_SK_WIRE] == s->key[PF_SK_STACK]) 770 s->key[PF_SK_WIRE] = NULL; 771 772 if (s->key[PF_SK_STACK] != NULL) 773 pf_state_key_detach(s, PF_SK_STACK); 774 775 if (s->key[PF_SK_WIRE] != NULL) 776 pf_state_key_detach(s, PF_SK_WIRE); 777 } 778 779 void 780 pf_state_key_detach(struct pf_state *s, int idx) 781 { 782 struct pf_state_item *si; 783 struct pf_state_key *sk; 784 785 if (s->key[idx] == NULL) 786 return; 787 788 si = TAILQ_FIRST(&s->key[idx]->states); 789 while (si && si->s != s) 790 si = TAILQ_NEXT(si, entry); 791 792 if (si) { 793 TAILQ_REMOVE(&s->key[idx]->states, si, entry); 794 pool_put(&pf_state_item_pl, si); 795 } 796 797 sk = s->key[idx]; 798 s->key[idx] = NULL; 799 if (TAILQ_EMPTY(&sk->states)) { 800 RB_REMOVE(pf_state_tree, &pf_statetbl, sk); 801 sk->removed = 1; 802 pf_state_key_unlink_reverse(sk); 803 pf_state_key_unlink_inpcb(sk); 804 pf_state_key_unref(sk); 805 } 806 } 807 808 struct pf_state_key * 809 pf_alloc_state_key(int pool_flags) 810 { 811 struct pf_state_key *sk; 812 813 if ((sk = pool_get(&pf_state_key_pl, pool_flags)) == NULL) 814 return (NULL); 815 TAILQ_INIT(&sk->states); 816 817 return (sk); 818 } 819 820 static __inline int 821 pf_state_key_addr_setup(struct pf_pdesc *pd, void *arg, int sidx, 822 struct pf_addr *saddr, int didx, struct pf_addr *daddr, int af, int multi) 823 { 824 struct pf_state_key_cmp *key = arg; 825 #ifdef INET6 826 struct pf_addr *target; 827 828 if (af == AF_INET || pd->proto != IPPROTO_ICMPV6) 829 goto copy; 830 831 switch (pd->hdr.icmp6.icmp6_type) { 832 case ND_NEIGHBOR_SOLICIT: 833 if (multi) 834 return (-1); 835 target = (struct pf_addr *)&pd->hdr.nd_ns.nd_ns_target; 836 daddr = target; 837 break; 838 case ND_NEIGHBOR_ADVERT: 839 if (multi) 840 return (-1); 841 target = (struct pf_addr *)&pd->hdr.nd_ns.nd_ns_target; 842 saddr = target; 843 if (IN6_IS_ADDR_MULTICAST(&pd->dst->v6)) { 844 key->addr[didx].addr32[0] = 0; 845 key->addr[didx].addr32[1] = 0; 846 key->addr[didx].addr32[2] = 0; 847 key->addr[didx].addr32[3] = 0; 848 daddr = NULL; /* overwritten */ 849 } 850 break; 851 default: 852 if (multi) { 853 key->addr[sidx].addr32[0] = __IPV6_ADDR_INT32_MLL; 854 key->addr[sidx].addr32[1] = 0; 855 key->addr[sidx].addr32[2] = 0; 856 key->addr[sidx].addr32[3] = __IPV6_ADDR_INT32_ONE; 857 saddr = NULL; /* overwritten */ 858 } 859 } 860 copy: 861 #endif /* INET6 */ 862 if (saddr) 863 pf_addrcpy(&key->addr[sidx], saddr, af); 864 if (daddr) 865 pf_addrcpy(&key->addr[didx], daddr, af); 866 867 return (0); 868 } 869 870 int 871 pf_state_key_setup(struct pf_pdesc *pd, struct pf_state_key **skw, 872 struct pf_state_key **sks, int rtableid) 873 { 874 /* if returning error we MUST pool_put state keys ourselves */ 875 struct pf_state_key *sk1, *sk2; 876 u_int wrdom = pd->rdomain; 877 int afto = pd->af != pd->naf; 878 879 if ((sk1 = pf_alloc_state_key(PR_NOWAIT | PR_ZERO)) == NULL) 880 return (ENOMEM); 881 882 pf_state_key_addr_setup(pd, sk1, pd->sidx, pd->src, pd->didx, pd->dst, 883 pd->af, 0); 884 sk1->port[pd->sidx] = pd->osport; 885 sk1->port[pd->didx] = pd->odport; 886 sk1->proto = pd->proto; 887 sk1->af = pd->af; 888 sk1->rdomain = pd->rdomain; 889 PF_REF_INIT(sk1->refcnt); 890 sk1->removed = 0; 891 if (rtableid >= 0) 892 wrdom = rtable_l2(rtableid); 893 894 if (PF_ANEQ(&pd->nsaddr, pd->src, pd->af) || 895 PF_ANEQ(&pd->ndaddr, pd->dst, pd->af) || 896 pd->nsport != pd->osport || pd->ndport != pd->odport || 897 wrdom != pd->rdomain || afto) { /* NAT/NAT64 */ 898 if ((sk2 = pf_alloc_state_key(PR_NOWAIT | PR_ZERO)) == NULL) { 899 pool_put(&pf_state_key_pl, sk1); 900 return (ENOMEM); 901 } 902 pf_state_key_addr_setup(pd, sk2, afto ? pd->didx : pd->sidx, 903 &pd->nsaddr, afto ? pd->sidx : pd->didx, &pd->ndaddr, 904 pd->naf, 0); 905 sk2->port[afto ? pd->didx : pd->sidx] = pd->nsport; 906 sk2->port[afto ? pd->sidx : pd->didx] = pd->ndport; 907 if (afto) { 908 switch (pd->proto) { 909 case IPPROTO_ICMP: 910 sk2->proto = IPPROTO_ICMPV6; 911 break; 912 case IPPROTO_ICMPV6: 913 sk2->proto = IPPROTO_ICMP; 914 break; 915 default: 916 sk2->proto = pd->proto; 917 } 918 } else 919 sk2->proto = pd->proto; 920 sk2->af = pd->naf; 921 sk2->rdomain = wrdom; 922 PF_REF_INIT(sk2->refcnt); 923 sk2->removed = 0; 924 } else 925 sk2 = sk1; 926 927 if (pd->dir == PF_IN) { 928 *skw = sk1; 929 *sks = sk2; 930 } else { 931 *sks = sk1; 932 *skw = sk2; 933 } 934 935 if (pf_status.debug >= LOG_DEBUG) { 936 log(LOG_DEBUG, "pf: key setup: "); 937 pf_print_state_parts(NULL, *skw, *sks); 938 addlog("\n"); 939 } 940 941 return (0); 942 } 943 944 int 945 pf_state_insert(struct pfi_kif *kif, struct pf_state_key **skw, 946 struct pf_state_key **sks, struct pf_state *s) 947 { 948 PF_ASSERT_LOCKED(); 949 950 s->kif = kif; 951 PF_STATE_ENTER_WRITE(); 952 if (*skw == *sks) { 953 if (pf_state_key_attach(*skw, s, PF_SK_WIRE)) { 954 PF_STATE_EXIT_WRITE(); 955 return (-1); 956 } 957 *skw = *sks = s->key[PF_SK_WIRE]; 958 s->key[PF_SK_STACK] = s->key[PF_SK_WIRE]; 959 } else { 960 if (pf_state_key_attach(*skw, s, PF_SK_WIRE)) { 961 pool_put(&pf_state_key_pl, *sks); 962 PF_STATE_EXIT_WRITE(); 963 return (-1); 964 } 965 *skw = s->key[PF_SK_WIRE]; 966 if (pf_state_key_attach(*sks, s, PF_SK_STACK)) { 967 pf_state_key_detach(s, PF_SK_WIRE); 968 PF_STATE_EXIT_WRITE(); 969 return (-1); 970 } 971 *sks = s->key[PF_SK_STACK]; 972 } 973 974 if (s->id == 0 && s->creatorid == 0) { 975 s->id = htobe64(pf_status.stateid++); 976 s->creatorid = pf_status.hostid; 977 } 978 if (RB_INSERT(pf_state_tree_id, &tree_id, s) != NULL) { 979 if (pf_status.debug >= LOG_NOTICE) { 980 log(LOG_NOTICE, "pf: state insert failed: " 981 "id: %016llx creatorid: %08x", 982 betoh64(s->id), ntohl(s->creatorid)); 983 addlog("\n"); 984 } 985 pf_detach_state(s); 986 PF_STATE_EXIT_WRITE(); 987 return (-1); 988 } 989 TAILQ_INSERT_TAIL(&state_list, s, entry_list); 990 pf_status.fcounters[FCNT_STATE_INSERT]++; 991 pf_status.states++; 992 pfi_kif_ref(kif, PFI_KIF_REF_STATE); 993 PF_STATE_EXIT_WRITE(); 994 #if NPFSYNC > 0 995 pfsync_insert_state(s); 996 #endif /* NPFSYNC > 0 */ 997 return (0); 998 } 999 1000 struct pf_state * 1001 pf_find_state_byid(struct pf_state_cmp *key) 1002 { 1003 pf_status.fcounters[FCNT_STATE_SEARCH]++; 1004 1005 return (RB_FIND(pf_state_tree_id, &tree_id, (struct pf_state *)key)); 1006 } 1007 1008 int 1009 pf_compare_state_keys(struct pf_state_key *a, struct pf_state_key *b, 1010 struct pfi_kif *kif, u_int dir) 1011 { 1012 /* a (from hdr) and b (new) must be exact opposites of each other */ 1013 if (a->af == b->af && a->proto == b->proto && 1014 PF_AEQ(&a->addr[0], &b->addr[1], a->af) && 1015 PF_AEQ(&a->addr[1], &b->addr[0], a->af) && 1016 a->port[0] == b->port[1] && 1017 a->port[1] == b->port[0] && a->rdomain == b->rdomain) 1018 return (0); 1019 else { 1020 /* mismatch. must not happen. */ 1021 if (pf_status.debug >= LOG_ERR) { 1022 log(LOG_ERR, 1023 "pf: state key linking mismatch! dir=%s, " 1024 "if=%s, stored af=%u, a0: ", 1025 dir == PF_OUT ? "OUT" : "IN", 1026 kif->pfik_name, a->af); 1027 pf_print_host(&a->addr[0], a->port[0], a->af); 1028 addlog(", a1: "); 1029 pf_print_host(&a->addr[1], a->port[1], a->af); 1030 addlog(", proto=%u", a->proto); 1031 addlog(", found af=%u, a0: ", b->af); 1032 pf_print_host(&b->addr[0], b->port[0], b->af); 1033 addlog(", a1: "); 1034 pf_print_host(&b->addr[1], b->port[1], b->af); 1035 addlog(", proto=%u", b->proto); 1036 addlog("\n"); 1037 } 1038 return (-1); 1039 } 1040 } 1041 1042 int 1043 pf_find_state(struct pf_pdesc *pd, struct pf_state_key_cmp *key, 1044 struct pf_state **state) 1045 { 1046 struct pf_state_key *sk, *pkt_sk, *inp_sk; 1047 struct pf_state_item *si; 1048 struct pf_state *s = NULL; 1049 1050 pf_status.fcounters[FCNT_STATE_SEARCH]++; 1051 if (pf_status.debug >= LOG_DEBUG) { 1052 log(LOG_DEBUG, "pf: key search, %s on %s: ", 1053 pd->dir == PF_OUT ? "out" : "in", pd->kif->pfik_name); 1054 pf_print_state_parts(NULL, (struct pf_state_key *)key, NULL); 1055 addlog("\n"); 1056 } 1057 1058 inp_sk = NULL; 1059 pkt_sk = NULL; 1060 sk = NULL; 1061 if (pd->dir == PF_OUT) { 1062 /* first if block deals with outbound forwarded packet */ 1063 pkt_sk = pd->m->m_pkthdr.pf.statekey; 1064 1065 if (!pf_state_key_isvalid(pkt_sk)) { 1066 pf_mbuf_unlink_state_key(pd->m); 1067 pkt_sk = NULL; 1068 } 1069 1070 if (pkt_sk && pf_state_key_isvalid(pkt_sk->reverse)) 1071 sk = pkt_sk->reverse; 1072 1073 if (pkt_sk == NULL) { 1074 /* here we deal with local outbound packet */ 1075 if (pd->m->m_pkthdr.pf.inp != NULL) { 1076 inp_sk = pd->m->m_pkthdr.pf.inp->inp_pf_sk; 1077 if (pf_state_key_isvalid(inp_sk)) 1078 sk = inp_sk; 1079 else 1080 pf_inpcb_unlink_state_key( 1081 pd->m->m_pkthdr.pf.inp); 1082 } 1083 } 1084 } 1085 1086 if (sk == NULL) { 1087 if ((sk = RB_FIND(pf_state_tree, &pf_statetbl, 1088 (struct pf_state_key *)key)) == NULL) 1089 return (PF_DROP); 1090 if (pd->dir == PF_OUT && pkt_sk && 1091 pf_compare_state_keys(pkt_sk, sk, pd->kif, pd->dir) == 0) 1092 pf_state_key_link_reverse(sk, pkt_sk); 1093 else if (pd->dir == PF_OUT && pd->m->m_pkthdr.pf.inp && 1094 !pd->m->m_pkthdr.pf.inp->inp_pf_sk && !sk->inp) 1095 pf_state_key_link_inpcb(sk, pd->m->m_pkthdr.pf.inp); 1096 } 1097 1098 /* remove firewall data from outbound packet */ 1099 if (pd->dir == PF_OUT) 1100 pf_pkt_addr_changed(pd->m); 1101 1102 /* list is sorted, if-bound states before floating ones */ 1103 TAILQ_FOREACH(si, &sk->states, entry) 1104 if ((si->s->kif == pfi_all || si->s->kif == pd->kif) && 1105 ((si->s->key[PF_SK_WIRE]->af == si->s->key[PF_SK_STACK]->af 1106 && sk == (pd->dir == PF_IN ? si->s->key[PF_SK_WIRE] : 1107 si->s->key[PF_SK_STACK])) || 1108 (si->s->key[PF_SK_WIRE]->af != si->s->key[PF_SK_STACK]->af 1109 && pd->dir == PF_IN && (sk == si->s->key[PF_SK_STACK] || 1110 sk == si->s->key[PF_SK_WIRE])))) { 1111 s = si->s; 1112 break; 1113 } 1114 1115 if (s == NULL || s->timeout == PFTM_PURGE) 1116 return (PF_DROP); 1117 1118 if (s->rule.ptr->pktrate.limit && pd->dir == s->direction) { 1119 pf_add_threshold(&s->rule.ptr->pktrate); 1120 if (pf_check_threshold(&s->rule.ptr->pktrate)) 1121 return (PF_DROP); 1122 } 1123 1124 *state = s; 1125 1126 return (PF_MATCH); 1127 } 1128 1129 struct pf_state * 1130 pf_find_state_all(struct pf_state_key_cmp *key, u_int dir, int *more) 1131 { 1132 struct pf_state_key *sk; 1133 struct pf_state_item *si, *ret = NULL; 1134 1135 pf_status.fcounters[FCNT_STATE_SEARCH]++; 1136 1137 sk = RB_FIND(pf_state_tree, &pf_statetbl, (struct pf_state_key *)key); 1138 1139 if (sk != NULL) { 1140 TAILQ_FOREACH(si, &sk->states, entry) 1141 if (dir == PF_INOUT || 1142 (sk == (dir == PF_IN ? si->s->key[PF_SK_WIRE] : 1143 si->s->key[PF_SK_STACK]))) { 1144 if (more == NULL) 1145 return (si->s); 1146 1147 if (ret) 1148 (*more)++; 1149 else 1150 ret = si; 1151 } 1152 } 1153 return (ret ? ret->s : NULL); 1154 } 1155 1156 void 1157 pf_state_export(struct pfsync_state *sp, struct pf_state *st) 1158 { 1159 int32_t expire; 1160 1161 memset(sp, 0, sizeof(struct pfsync_state)); 1162 1163 /* copy from state key */ 1164 sp->key[PF_SK_WIRE].addr[0] = st->key[PF_SK_WIRE]->addr[0]; 1165 sp->key[PF_SK_WIRE].addr[1] = st->key[PF_SK_WIRE]->addr[1]; 1166 sp->key[PF_SK_WIRE].port[0] = st->key[PF_SK_WIRE]->port[0]; 1167 sp->key[PF_SK_WIRE].port[1] = st->key[PF_SK_WIRE]->port[1]; 1168 sp->key[PF_SK_WIRE].rdomain = htons(st->key[PF_SK_WIRE]->rdomain); 1169 sp->key[PF_SK_WIRE].af = st->key[PF_SK_WIRE]->af; 1170 sp->key[PF_SK_STACK].addr[0] = st->key[PF_SK_STACK]->addr[0]; 1171 sp->key[PF_SK_STACK].addr[1] = st->key[PF_SK_STACK]->addr[1]; 1172 sp->key[PF_SK_STACK].port[0] = st->key[PF_SK_STACK]->port[0]; 1173 sp->key[PF_SK_STACK].port[1] = st->key[PF_SK_STACK]->port[1]; 1174 sp->key[PF_SK_STACK].rdomain = htons(st->key[PF_SK_STACK]->rdomain); 1175 sp->key[PF_SK_STACK].af = st->key[PF_SK_STACK]->af; 1176 sp->rtableid[PF_SK_WIRE] = htonl(st->rtableid[PF_SK_WIRE]); 1177 sp->rtableid[PF_SK_STACK] = htonl(st->rtableid[PF_SK_STACK]); 1178 sp->proto = st->key[PF_SK_WIRE]->proto; 1179 sp->af = st->key[PF_SK_WIRE]->af; 1180 1181 /* copy from state */ 1182 strlcpy(sp->ifname, st->kif->pfik_name, sizeof(sp->ifname)); 1183 sp->rt = st->rt; 1184 sp->rt_addr = st->rt_addr; 1185 sp->creation = htonl(getuptime() - st->creation); 1186 expire = pf_state_expires(st); 1187 if (expire <= getuptime()) 1188 sp->expire = htonl(0); 1189 else 1190 sp->expire = htonl(expire - getuptime()); 1191 1192 sp->direction = st->direction; 1193 #if NPFLOG > 0 1194 sp->log = st->log; 1195 #endif /* NPFLOG > 0 */ 1196 sp->timeout = st->timeout; 1197 sp->state_flags = htons(st->state_flags); 1198 if (!SLIST_EMPTY(&st->src_nodes)) 1199 sp->sync_flags |= PFSYNC_FLAG_SRCNODE; 1200 1201 sp->id = st->id; 1202 sp->creatorid = st->creatorid; 1203 pf_state_peer_hton(&st->src, &sp->src); 1204 pf_state_peer_hton(&st->dst, &sp->dst); 1205 1206 if (st->rule.ptr == NULL) 1207 sp->rule = htonl(-1); 1208 else 1209 sp->rule = htonl(st->rule.ptr->nr); 1210 if (st->anchor.ptr == NULL) 1211 sp->anchor = htonl(-1); 1212 else 1213 sp->anchor = htonl(st->anchor.ptr->nr); 1214 sp->nat_rule = htonl(-1); /* left for compat, nat_rule is gone */ 1215 1216 pf_state_counter_hton(st->packets[0], sp->packets[0]); 1217 pf_state_counter_hton(st->packets[1], sp->packets[1]); 1218 pf_state_counter_hton(st->bytes[0], sp->bytes[0]); 1219 pf_state_counter_hton(st->bytes[1], sp->bytes[1]); 1220 1221 sp->max_mss = htons(st->max_mss); 1222 sp->min_ttl = st->min_ttl; 1223 sp->set_tos = st->set_tos; 1224 sp->set_prio[0] = st->set_prio[0]; 1225 sp->set_prio[1] = st->set_prio[1]; 1226 } 1227 1228 /* END state table stuff */ 1229 1230 void 1231 pf_purge_expired_rules(void) 1232 { 1233 struct pf_rule *r; 1234 1235 PF_ASSERT_LOCKED(); 1236 1237 if (SLIST_EMPTY(&pf_rule_gcl)) 1238 return; 1239 1240 while ((r = SLIST_FIRST(&pf_rule_gcl)) != NULL) { 1241 SLIST_REMOVE(&pf_rule_gcl, r, pf_rule, gcle); 1242 KASSERT(r->rule_flag & PFRULE_EXPIRED); 1243 pf_purge_rule(r); 1244 } 1245 } 1246 1247 void 1248 pf_purge_timeout(void *unused) 1249 { 1250 task_add(net_tq(0), &pf_purge_task); 1251 } 1252 1253 void 1254 pf_purge(void *xnloops) 1255 { 1256 int *nloops = xnloops; 1257 1258 KERNEL_LOCK(); 1259 NET_LOCK(); 1260 1261 /* 1262 * process a fraction of the state table every second 1263 * Note: 1264 * we no longer need PF_LOCK() here, because 1265 * pf_purge_expired_states() uses pf_state_lock to maintain 1266 * consistency. 1267 */ 1268 pf_purge_expired_states(1 + (pf_status.states 1269 / pf_default_rule.timeout[PFTM_INTERVAL])); 1270 1271 PF_LOCK(); 1272 /* purge other expired types every PFTM_INTERVAL seconds */ 1273 if (++(*nloops) >= pf_default_rule.timeout[PFTM_INTERVAL]) { 1274 pf_purge_expired_src_nodes(); 1275 pf_purge_expired_rules(); 1276 } 1277 PF_UNLOCK(); 1278 1279 /* 1280 * Fragments don't require PF_LOCK(), they use their own lock. 1281 */ 1282 if ((*nloops) >= pf_default_rule.timeout[PFTM_INTERVAL]) { 1283 pf_purge_expired_fragments(); 1284 *nloops = 0; 1285 } 1286 NET_UNLOCK(); 1287 KERNEL_UNLOCK(); 1288 1289 timeout_add_sec(&pf_purge_to, 1); 1290 } 1291 1292 int32_t 1293 pf_state_expires(const struct pf_state *state) 1294 { 1295 u_int32_t timeout; 1296 u_int32_t start; 1297 u_int32_t end; 1298 u_int32_t states; 1299 1300 /* handle all PFTM_* > PFTM_MAX here */ 1301 if (state->timeout == PFTM_PURGE) 1302 return (0); 1303 1304 KASSERT(state->timeout != PFTM_UNLINKED); 1305 KASSERT(state->timeout < PFTM_MAX); 1306 1307 timeout = state->rule.ptr->timeout[state->timeout]; 1308 if (!timeout) 1309 timeout = pf_default_rule.timeout[state->timeout]; 1310 1311 start = state->rule.ptr->timeout[PFTM_ADAPTIVE_START]; 1312 if (start) { 1313 end = state->rule.ptr->timeout[PFTM_ADAPTIVE_END]; 1314 states = state->rule.ptr->states_cur; 1315 } else { 1316 start = pf_default_rule.timeout[PFTM_ADAPTIVE_START]; 1317 end = pf_default_rule.timeout[PFTM_ADAPTIVE_END]; 1318 states = pf_status.states; 1319 } 1320 if (end && states > start && start < end) { 1321 if (states >= end) 1322 return (0); 1323 1324 timeout = (u_int64_t)timeout * (end - states) / (end - start); 1325 } 1326 1327 return (state->expire + timeout); 1328 } 1329 1330 void 1331 pf_purge_expired_src_nodes(void) 1332 { 1333 struct pf_src_node *cur, *next; 1334 1335 PF_ASSERT_LOCKED(); 1336 1337 for (cur = RB_MIN(pf_src_tree, &tree_src_tracking); cur; cur = next) { 1338 next = RB_NEXT(pf_src_tree, &tree_src_tracking, cur); 1339 1340 if (cur->states == 0 && cur->expire <= getuptime()) { 1341 next = RB_NEXT(pf_src_tree, &tree_src_tracking, cur); 1342 pf_remove_src_node(cur); 1343 } 1344 } 1345 } 1346 1347 void 1348 pf_src_tree_remove_state(struct pf_state *s) 1349 { 1350 u_int32_t timeout; 1351 struct pf_sn_item *sni; 1352 1353 while ((sni = SLIST_FIRST(&s->src_nodes)) != NULL) { 1354 SLIST_REMOVE_HEAD(&s->src_nodes, next); 1355 if (s->src.tcp_est) 1356 --sni->sn->conn; 1357 if (--sni->sn->states == 0) { 1358 timeout = s->rule.ptr->timeout[PFTM_SRC_NODE]; 1359 if (!timeout) 1360 timeout = 1361 pf_default_rule.timeout[PFTM_SRC_NODE]; 1362 sni->sn->expire = getuptime() + timeout; 1363 } 1364 pool_put(&pf_sn_item_pl, sni); 1365 } 1366 } 1367 1368 void 1369 pf_remove_state(struct pf_state *cur) 1370 { 1371 PF_ASSERT_LOCKED(); 1372 1373 /* handle load balancing related tasks */ 1374 pf_postprocess_addr(cur); 1375 1376 if (cur->src.state == PF_TCPS_PROXY_DST) { 1377 pf_send_tcp(cur->rule.ptr, cur->key[PF_SK_WIRE]->af, 1378 &cur->key[PF_SK_WIRE]->addr[1], 1379 &cur->key[PF_SK_WIRE]->addr[0], 1380 cur->key[PF_SK_WIRE]->port[1], 1381 cur->key[PF_SK_WIRE]->port[0], 1382 cur->src.seqhi, cur->src.seqlo + 1, 1383 TH_RST|TH_ACK, 0, 0, 0, 1, cur->tag, 1384 cur->key[PF_SK_WIRE]->rdomain); 1385 } 1386 if (cur->key[PF_SK_STACK]->proto == IPPROTO_TCP) 1387 pf_set_protostate(cur, PF_PEER_BOTH, TCPS_CLOSED); 1388 1389 RB_REMOVE(pf_state_tree_id, &tree_id, cur); 1390 #if NPFLOW > 0 1391 if (cur->state_flags & PFSTATE_PFLOW) 1392 export_pflow(cur); 1393 #endif /* NPFLOW > 0 */ 1394 #if NPFSYNC > 0 1395 pfsync_delete_state(cur); 1396 #endif /* NPFSYNC > 0 */ 1397 cur->timeout = PFTM_UNLINKED; 1398 pf_src_tree_remove_state(cur); 1399 pf_detach_state(cur); 1400 } 1401 1402 void 1403 pf_remove_divert_state(struct pf_state_key *sk) 1404 { 1405 struct pf_state_item *si; 1406 1407 PF_ASSERT_UNLOCKED(); 1408 1409 PF_LOCK(); 1410 PF_STATE_ENTER_WRITE(); 1411 TAILQ_FOREACH(si, &sk->states, entry) { 1412 if (sk == si->s->key[PF_SK_STACK] && si->s->rule.ptr && 1413 (si->s->rule.ptr->divert.type == PF_DIVERT_TO || 1414 si->s->rule.ptr->divert.type == PF_DIVERT_REPLY)) { 1415 pf_remove_state(si->s); 1416 break; 1417 } 1418 } 1419 PF_STATE_EXIT_WRITE(); 1420 PF_UNLOCK(); 1421 } 1422 1423 void 1424 pf_free_state(struct pf_state *cur) 1425 { 1426 struct pf_rule_item *ri; 1427 1428 PF_ASSERT_LOCKED(); 1429 1430 #if NPFSYNC > 0 1431 if (pfsync_state_in_use(cur)) 1432 return; 1433 #endif /* NPFSYNC > 0 */ 1434 KASSERT(cur->timeout == PFTM_UNLINKED); 1435 if (--cur->rule.ptr->states_cur == 0 && 1436 cur->rule.ptr->src_nodes == 0) 1437 pf_rm_rule(NULL, cur->rule.ptr); 1438 if (cur->anchor.ptr != NULL) 1439 if (--cur->anchor.ptr->states_cur == 0) 1440 pf_rm_rule(NULL, cur->anchor.ptr); 1441 while ((ri = SLIST_FIRST(&cur->match_rules))) { 1442 SLIST_REMOVE_HEAD(&cur->match_rules, entry); 1443 if (--ri->r->states_cur == 0 && 1444 ri->r->src_nodes == 0) 1445 pf_rm_rule(NULL, ri->r); 1446 pool_put(&pf_rule_item_pl, ri); 1447 } 1448 pf_normalize_tcp_cleanup(cur); 1449 pfi_kif_unref(cur->kif, PFI_KIF_REF_STATE); 1450 TAILQ_REMOVE(&state_list, cur, entry_list); 1451 if (cur->tag) 1452 pf_tag_unref(cur->tag); 1453 pf_state_unref(cur); 1454 pf_status.fcounters[FCNT_STATE_REMOVALS]++; 1455 pf_status.states--; 1456 } 1457 1458 void 1459 pf_purge_expired_states(u_int32_t maxcheck) 1460 { 1461 static struct pf_state *cur = NULL; 1462 struct pf_state *next; 1463 SLIST_HEAD(pf_state_gcl, pf_state) gcl; 1464 1465 PF_ASSERT_UNLOCKED(); 1466 SLIST_INIT(&gcl); 1467 1468 PF_STATE_ENTER_READ(); 1469 while (maxcheck--) { 1470 /* wrap to start of list when we hit the end */ 1471 if (cur == NULL) { 1472 cur = pf_state_ref(TAILQ_FIRST(&state_list)); 1473 if (cur == NULL) 1474 break; /* list empty */ 1475 } 1476 1477 /* get next state, as cur may get deleted */ 1478 next = TAILQ_NEXT(cur, entry_list); 1479 1480 if ((cur->timeout == PFTM_UNLINKED) || 1481 (pf_state_expires(cur) <= getuptime())) 1482 SLIST_INSERT_HEAD(&gcl, cur, gc_list); 1483 else 1484 pf_state_unref(cur); 1485 1486 cur = pf_state_ref(next); 1487 1488 if (cur == NULL) 1489 break; 1490 } 1491 PF_STATE_EXIT_READ(); 1492 1493 PF_LOCK(); 1494 PF_STATE_ENTER_WRITE(); 1495 while ((next = SLIST_FIRST(&gcl)) != NULL) { 1496 SLIST_REMOVE_HEAD(&gcl, gc_list); 1497 if (next->timeout == PFTM_UNLINKED) 1498 pf_free_state(next); 1499 else { 1500 pf_remove_state(next); 1501 pf_free_state(next); 1502 } 1503 1504 pf_state_unref(next); 1505 } 1506 PF_STATE_EXIT_WRITE(); 1507 PF_UNLOCK(); 1508 } 1509 1510 int 1511 pf_tbladdr_setup(struct pf_ruleset *rs, struct pf_addr_wrap *aw) 1512 { 1513 if (aw->type != PF_ADDR_TABLE) 1514 return (0); 1515 if ((aw->p.tbl = pfr_attach_table(rs, aw->v.tblname, 1)) == NULL) 1516 return (1); 1517 return (0); 1518 } 1519 1520 void 1521 pf_tbladdr_remove(struct pf_addr_wrap *aw) 1522 { 1523 if (aw->type != PF_ADDR_TABLE || aw->p.tbl == NULL) 1524 return; 1525 pfr_detach_table(aw->p.tbl); 1526 aw->p.tbl = NULL; 1527 } 1528 1529 void 1530 pf_tbladdr_copyout(struct pf_addr_wrap *aw) 1531 { 1532 struct pfr_ktable *kt = aw->p.tbl; 1533 1534 if (aw->type != PF_ADDR_TABLE || kt == NULL) 1535 return; 1536 if (!(kt->pfrkt_flags & PFR_TFLAG_ACTIVE) && kt->pfrkt_root != NULL) 1537 kt = kt->pfrkt_root; 1538 aw->p.tbl = NULL; 1539 aw->p.tblcnt = (kt->pfrkt_flags & PFR_TFLAG_ACTIVE) ? 1540 kt->pfrkt_cnt : -1; 1541 } 1542 1543 void 1544 pf_print_host(struct pf_addr *addr, u_int16_t p, sa_family_t af) 1545 { 1546 switch (af) { 1547 case AF_INET: { 1548 u_int32_t a = ntohl(addr->addr32[0]); 1549 addlog("%u.%u.%u.%u", (a>>24)&255, (a>>16)&255, 1550 (a>>8)&255, a&255); 1551 if (p) { 1552 p = ntohs(p); 1553 addlog(":%u", p); 1554 } 1555 break; 1556 } 1557 #ifdef INET6 1558 case AF_INET6: { 1559 u_int16_t b; 1560 u_int8_t i, curstart, curend, maxstart, maxend; 1561 curstart = curend = maxstart = maxend = 255; 1562 for (i = 0; i < 8; i++) { 1563 if (!addr->addr16[i]) { 1564 if (curstart == 255) 1565 curstart = i; 1566 curend = i; 1567 } else { 1568 if ((curend - curstart) > 1569 (maxend - maxstart)) { 1570 maxstart = curstart; 1571 maxend = curend; 1572 } 1573 curstart = curend = 255; 1574 } 1575 } 1576 if ((curend - curstart) > 1577 (maxend - maxstart)) { 1578 maxstart = curstart; 1579 maxend = curend; 1580 } 1581 for (i = 0; i < 8; i++) { 1582 if (i >= maxstart && i <= maxend) { 1583 if (i == 0) 1584 addlog(":"); 1585 if (i == maxend) 1586 addlog(":"); 1587 } else { 1588 b = ntohs(addr->addr16[i]); 1589 addlog("%x", b); 1590 if (i < 7) 1591 addlog(":"); 1592 } 1593 } 1594 if (p) { 1595 p = ntohs(p); 1596 addlog("[%u]", p); 1597 } 1598 break; 1599 } 1600 #endif /* INET6 */ 1601 } 1602 } 1603 1604 void 1605 pf_print_state(struct pf_state *s) 1606 { 1607 pf_print_state_parts(s, NULL, NULL); 1608 } 1609 1610 void 1611 pf_print_state_parts(struct pf_state *s, 1612 struct pf_state_key *skwp, struct pf_state_key *sksp) 1613 { 1614 struct pf_state_key *skw, *sks; 1615 u_int8_t proto, dir; 1616 1617 /* Do our best to fill these, but they're skipped if NULL */ 1618 skw = skwp ? skwp : (s ? s->key[PF_SK_WIRE] : NULL); 1619 sks = sksp ? sksp : (s ? s->key[PF_SK_STACK] : NULL); 1620 proto = skw ? skw->proto : (sks ? sks->proto : 0); 1621 dir = s ? s->direction : 0; 1622 1623 switch (proto) { 1624 case IPPROTO_IPV4: 1625 addlog("IPv4"); 1626 break; 1627 case IPPROTO_IPV6: 1628 addlog("IPv6"); 1629 break; 1630 case IPPROTO_TCP: 1631 addlog("TCP"); 1632 break; 1633 case IPPROTO_UDP: 1634 addlog("UDP"); 1635 break; 1636 case IPPROTO_ICMP: 1637 addlog("ICMP"); 1638 break; 1639 case IPPROTO_ICMPV6: 1640 addlog("ICMPv6"); 1641 break; 1642 default: 1643 addlog("%u", proto); 1644 break; 1645 } 1646 switch (dir) { 1647 case PF_IN: 1648 addlog(" in"); 1649 break; 1650 case PF_OUT: 1651 addlog(" out"); 1652 break; 1653 } 1654 if (skw) { 1655 addlog(" wire: (%d) ", skw->rdomain); 1656 pf_print_host(&skw->addr[0], skw->port[0], skw->af); 1657 addlog(" "); 1658 pf_print_host(&skw->addr[1], skw->port[1], skw->af); 1659 } 1660 if (sks) { 1661 addlog(" stack: (%d) ", sks->rdomain); 1662 if (sks != skw) { 1663 pf_print_host(&sks->addr[0], sks->port[0], sks->af); 1664 addlog(" "); 1665 pf_print_host(&sks->addr[1], sks->port[1], sks->af); 1666 } else 1667 addlog("-"); 1668 } 1669 if (s) { 1670 if (proto == IPPROTO_TCP) { 1671 addlog(" [lo=%u high=%u win=%u modulator=%u", 1672 s->src.seqlo, s->src.seqhi, 1673 s->src.max_win, s->src.seqdiff); 1674 if (s->src.wscale && s->dst.wscale) 1675 addlog(" wscale=%u", 1676 s->src.wscale & PF_WSCALE_MASK); 1677 addlog("]"); 1678 addlog(" [lo=%u high=%u win=%u modulator=%u", 1679 s->dst.seqlo, s->dst.seqhi, 1680 s->dst.max_win, s->dst.seqdiff); 1681 if (s->src.wscale && s->dst.wscale) 1682 addlog(" wscale=%u", 1683 s->dst.wscale & PF_WSCALE_MASK); 1684 addlog("]"); 1685 } 1686 addlog(" %u:%u", s->src.state, s->dst.state); 1687 if (s->rule.ptr) 1688 addlog(" @%d", s->rule.ptr->nr); 1689 } 1690 } 1691 1692 void 1693 pf_print_flags(u_int8_t f) 1694 { 1695 if (f) 1696 addlog(" "); 1697 if (f & TH_FIN) 1698 addlog("F"); 1699 if (f & TH_SYN) 1700 addlog("S"); 1701 if (f & TH_RST) 1702 addlog("R"); 1703 if (f & TH_PUSH) 1704 addlog("P"); 1705 if (f & TH_ACK) 1706 addlog("A"); 1707 if (f & TH_URG) 1708 addlog("U"); 1709 if (f & TH_ECE) 1710 addlog("E"); 1711 if (f & TH_CWR) 1712 addlog("W"); 1713 } 1714 1715 #define PF_SET_SKIP_STEPS(i) \ 1716 do { \ 1717 while (head[i] != cur) { \ 1718 head[i]->skip[i].ptr = cur; \ 1719 head[i] = TAILQ_NEXT(head[i], entries); \ 1720 } \ 1721 } while (0) 1722 1723 void 1724 pf_calc_skip_steps(struct pf_rulequeue *rules) 1725 { 1726 struct pf_rule *cur, *prev, *head[PF_SKIP_COUNT]; 1727 int i; 1728 1729 cur = TAILQ_FIRST(rules); 1730 prev = cur; 1731 for (i = 0; i < PF_SKIP_COUNT; ++i) 1732 head[i] = cur; 1733 while (cur != NULL) { 1734 if (cur->kif != prev->kif || cur->ifnot != prev->ifnot) 1735 PF_SET_SKIP_STEPS(PF_SKIP_IFP); 1736 if (cur->direction != prev->direction) 1737 PF_SET_SKIP_STEPS(PF_SKIP_DIR); 1738 if (cur->onrdomain != prev->onrdomain || 1739 cur->ifnot != prev->ifnot) 1740 PF_SET_SKIP_STEPS(PF_SKIP_RDOM); 1741 if (cur->af != prev->af) 1742 PF_SET_SKIP_STEPS(PF_SKIP_AF); 1743 if (cur->proto != prev->proto) 1744 PF_SET_SKIP_STEPS(PF_SKIP_PROTO); 1745 if (cur->src.neg != prev->src.neg || 1746 pf_addr_wrap_neq(&cur->src.addr, &prev->src.addr)) 1747 PF_SET_SKIP_STEPS(PF_SKIP_SRC_ADDR); 1748 if (cur->dst.neg != prev->dst.neg || 1749 pf_addr_wrap_neq(&cur->dst.addr, &prev->dst.addr)) 1750 PF_SET_SKIP_STEPS(PF_SKIP_DST_ADDR); 1751 if (cur->src.port[0] != prev->src.port[0] || 1752 cur->src.port[1] != prev->src.port[1] || 1753 cur->src.port_op != prev->src.port_op) 1754 PF_SET_SKIP_STEPS(PF_SKIP_SRC_PORT); 1755 if (cur->dst.port[0] != prev->dst.port[0] || 1756 cur->dst.port[1] != prev->dst.port[1] || 1757 cur->dst.port_op != prev->dst.port_op) 1758 PF_SET_SKIP_STEPS(PF_SKIP_DST_PORT); 1759 1760 prev = cur; 1761 cur = TAILQ_NEXT(cur, entries); 1762 } 1763 for (i = 0; i < PF_SKIP_COUNT; ++i) 1764 PF_SET_SKIP_STEPS(i); 1765 } 1766 1767 int 1768 pf_addr_wrap_neq(struct pf_addr_wrap *aw1, struct pf_addr_wrap *aw2) 1769 { 1770 if (aw1->type != aw2->type) 1771 return (1); 1772 switch (aw1->type) { 1773 case PF_ADDR_ADDRMASK: 1774 case PF_ADDR_RANGE: 1775 if (PF_ANEQ(&aw1->v.a.addr, &aw2->v.a.addr, AF_INET6)) 1776 return (1); 1777 if (PF_ANEQ(&aw1->v.a.mask, &aw2->v.a.mask, AF_INET6)) 1778 return (1); 1779 return (0); 1780 case PF_ADDR_DYNIFTL: 1781 return (aw1->p.dyn->pfid_kt != aw2->p.dyn->pfid_kt); 1782 case PF_ADDR_NONE: 1783 case PF_ADDR_NOROUTE: 1784 case PF_ADDR_URPFFAILED: 1785 return (0); 1786 case PF_ADDR_TABLE: 1787 return (aw1->p.tbl != aw2->p.tbl); 1788 case PF_ADDR_RTLABEL: 1789 return (aw1->v.rtlabel != aw2->v.rtlabel); 1790 default: 1791 addlog("invalid address type: %d\n", aw1->type); 1792 return (1); 1793 } 1794 } 1795 1796 /* This algorithm computes 'a + b - c' in ones-complement using a trick to 1797 * emulate at most one ones-complement subtraction. This thereby limits net 1798 * carries/borrows to at most one, eliminating a reduction step and saving one 1799 * each of +, >>, & and ~. 1800 * 1801 * def. x mod y = x - (x//y)*y for integer x,y 1802 * def. sum = x mod 2^16 1803 * def. accumulator = (x >> 16) mod 2^16 1804 * 1805 * The trick works as follows: subtracting exactly one u_int16_t from the 1806 * u_int32_t x incurs at most one underflow, wrapping its upper 16-bits, the 1807 * accumulator, to 2^16 - 1. Adding this to the 16-bit sum preserves the 1808 * ones-complement borrow: 1809 * 1810 * (sum + accumulator) mod 2^16 1811 * = { assume underflow: accumulator := 2^16 - 1 } 1812 * (sum + 2^16 - 1) mod 2^16 1813 * = { mod } 1814 * (sum - 1) mod 2^16 1815 * 1816 * Although this breaks for sum = 0, giving 0xffff, which is ones-complement's 1817 * other zero, not -1, that cannot occur: the 16-bit sum cannot be underflown 1818 * to zero as that requires subtraction of at least 2^16, which exceeds a 1819 * single u_int16_t's range. 1820 * 1821 * We use the following theorem to derive the implementation: 1822 * 1823 * th. (x + (y mod z)) mod z = (x + y) mod z (0) 1824 * proof. 1825 * (x + (y mod z)) mod z 1826 * = { def mod } 1827 * (x + y - (y//z)*z) mod z 1828 * = { (a + b*c) mod c = a mod c } 1829 * (x + y) mod z [end of proof] 1830 * 1831 * ... and thereby obtain: 1832 * 1833 * (sum + accumulator) mod 2^16 1834 * = { def. accumulator, def. sum } 1835 * (x mod 2^16 + (x >> 16) mod 2^16) mod 2^16 1836 * = { (0), twice } 1837 * (x + (x >> 16)) mod 2^16 1838 * = { x mod 2^n = x & (2^n - 1) } 1839 * (x + (x >> 16)) & 0xffff 1840 * 1841 * Note: this serves also as a reduction step for at most one add (as the 1842 * trailing mod 2^16 prevents further reductions by destroying carries). 1843 */ 1844 static __inline void 1845 pf_cksum_fixup(u_int16_t *cksum, u_int16_t was, u_int16_t now, 1846 u_int8_t proto) 1847 { 1848 u_int32_t x; 1849 const int udp = proto == IPPROTO_UDP; 1850 1851 x = *cksum + was - now; 1852 x = (x + (x >> 16)) & 0xffff; 1853 1854 /* optimise: eliminate a branch when not udp */ 1855 if (udp && *cksum == 0x0000) 1856 return; 1857 if (udp && x == 0x0000) 1858 x = 0xffff; 1859 1860 *cksum = (u_int16_t)(x); 1861 } 1862 1863 #ifdef INET6 1864 /* pre: coverage(cksum) is superset of coverage(covered_cksum) */ 1865 static __inline void 1866 pf_cksum_uncover(u_int16_t *cksum, u_int16_t covered_cksum, u_int8_t proto) 1867 { 1868 pf_cksum_fixup(cksum, ~covered_cksum, 0x0, proto); 1869 } 1870 1871 /* pre: disjoint(coverage(cksum), coverage(uncovered_cksum)) */ 1872 static __inline void 1873 pf_cksum_cover(u_int16_t *cksum, u_int16_t uncovered_cksum, u_int8_t proto) 1874 { 1875 pf_cksum_fixup(cksum, 0x0, ~uncovered_cksum, proto); 1876 } 1877 #endif /* INET6 */ 1878 1879 /* pre: *a is 16-bit aligned within its packet 1880 * 1881 * This algorithm emulates 16-bit ones-complement sums on a twos-complement 1882 * machine by conserving ones-complement's otherwise discarded carries in the 1883 * upper bits of x. These accumulated carries when added to the lower 16-bits 1884 * over at least zero 'reduction' steps then complete the ones-complement sum. 1885 * 1886 * def. sum = x mod 2^16 1887 * def. accumulator = (x >> 16) 1888 * 1889 * At most two reduction steps 1890 * 1891 * x := sum + accumulator 1892 * = { def sum, def accumulator } 1893 * x := x mod 2^16 + (x >> 16) 1894 * = { x mod 2^n = x & (2^n - 1) } 1895 * x := (x & 0xffff) + (x >> 16) 1896 * 1897 * are necessary to incorporate the accumulated carries (at most one per add) 1898 * i.e. to reduce x < 2^16 from at most 16 carries in the upper 16 bits. 1899 * 1900 * The function is also invariant over the endian of the host. Why? 1901 * 1902 * Define the unary transpose operator ~ on a bitstring in python slice 1903 * notation as lambda m: m[P:] + m[:P] , for some constant pivot P. 1904 * 1905 * th. ~ distributes over ones-complement addition, denoted by +_1, i.e. 1906 * 1907 * ~m +_1 ~n = ~(m +_1 n) (for all bitstrings m,n of equal length) 1908 * 1909 * proof. Regard the bitstrings in m +_1 n as split at P, forming at most two 1910 * 'half-adds'. Under ones-complement addition, each half-add carries to the 1911 * other, so the sum of each half-add is unaffected by their relative 1912 * order. Therefore: 1913 * 1914 * ~m +_1 ~n 1915 * = { half-adds invariant under transposition } 1916 * ~s 1917 * = { substitute } 1918 * ~(m +_1 n) [end of proof] 1919 * 1920 * th. Summing two in-memory ones-complement 16-bit variables m,n on a machine 1921 * with the converse endian does not alter the result. 1922 * 1923 * proof. 1924 * { converse machine endian: load/store transposes, P := 8 } 1925 * ~(~m +_1 ~n) 1926 * = { ~ over +_1 } 1927 * ~~m +_1 ~~n 1928 * = { ~ is an involution } 1929 * m +_1 n [end of proof] 1930 * 1931 */ 1932 #define NEG(x) ((u_int16_t)~(x)) 1933 void 1934 pf_cksum_fixup_a(u_int16_t *cksum, const struct pf_addr *a, 1935 const struct pf_addr *an, sa_family_t af, u_int8_t proto) 1936 { 1937 u_int32_t x; 1938 const u_int16_t *n = an->addr16; 1939 const u_int16_t *o = a->addr16; 1940 const int udp = proto == IPPROTO_UDP; 1941 1942 switch (af) { 1943 case AF_INET: 1944 x = *cksum + o[0] + NEG(n[0]) + o[1] + NEG(n[1]); 1945 break; 1946 #ifdef INET6 1947 case AF_INET6: 1948 x = *cksum + o[0] + NEG(n[0]) + o[1] + NEG(n[1]) +\ 1949 o[2] + NEG(n[2]) + o[3] + NEG(n[3]) +\ 1950 o[4] + NEG(n[4]) + o[5] + NEG(n[5]) +\ 1951 o[6] + NEG(n[6]) + o[7] + NEG(n[7]); 1952 break; 1953 #endif /* INET6 */ 1954 default: 1955 unhandled_af(af); 1956 } 1957 1958 x = (x & 0xffff) + (x >> 16); 1959 x = (x & 0xffff) + (x >> 16); 1960 1961 /* optimise: eliminate a branch when not udp */ 1962 if (udp && *cksum == 0x0000) 1963 return; 1964 if (udp && x == 0x0000) 1965 x = 0xffff; 1966 1967 *cksum = (u_int16_t)(x); 1968 } 1969 1970 int 1971 pf_patch_8(struct pf_pdesc *pd, u_int8_t *f, u_int8_t v, bool hi) 1972 { 1973 int rewrite = 0; 1974 1975 if (*f != v) { 1976 u_int16_t old = htons(hi ? (*f << 8) : *f); 1977 u_int16_t new = htons(hi ? ( v << 8) : v); 1978 1979 pf_cksum_fixup(pd->pcksum, old, new, pd->proto); 1980 *f = v; 1981 rewrite = 1; 1982 } 1983 1984 return (rewrite); 1985 } 1986 1987 /* pre: *f is 16-bit aligned within its packet */ 1988 int 1989 pf_patch_16(struct pf_pdesc *pd, u_int16_t *f, u_int16_t v) 1990 { 1991 int rewrite = 0; 1992 1993 if (*f != v) { 1994 pf_cksum_fixup(pd->pcksum, *f, v, pd->proto); 1995 *f = v; 1996 rewrite = 1; 1997 } 1998 1999 return (rewrite); 2000 } 2001 2002 int 2003 pf_patch_16_unaligned(struct pf_pdesc *pd, void *f, u_int16_t v, bool hi) 2004 { 2005 int rewrite = 0; 2006 u_int8_t *fb = (u_int8_t*)f; 2007 u_int8_t *vb = (u_int8_t*)&v; 2008 2009 if (hi && ALIGNED_POINTER(f, u_int16_t)) { 2010 return (pf_patch_16(pd, f, v)); /* optimise */ 2011 } 2012 2013 rewrite += pf_patch_8(pd, fb++, *vb++, hi); 2014 rewrite += pf_patch_8(pd, fb++, *vb++,!hi); 2015 2016 return (rewrite); 2017 } 2018 2019 /* pre: *f is 16-bit aligned within its packet */ 2020 /* pre: pd->proto != IPPROTO_UDP */ 2021 int 2022 pf_patch_32(struct pf_pdesc *pd, u_int32_t *f, u_int32_t v) 2023 { 2024 int rewrite = 0; 2025 u_int16_t *pc = pd->pcksum; 2026 u_int8_t proto = pd->proto; 2027 2028 /* optimise: inline udp fixup code is unused; let compiler scrub it */ 2029 if (proto == IPPROTO_UDP) 2030 panic("%s: udp", __func__); 2031 2032 /* optimise: skip *f != v guard; true for all use-cases */ 2033 pf_cksum_fixup(pc, *f / (1 << 16), v / (1 << 16), proto); 2034 pf_cksum_fixup(pc, *f % (1 << 16), v % (1 << 16), proto); 2035 2036 *f = v; 2037 rewrite = 1; 2038 2039 return (rewrite); 2040 } 2041 2042 int 2043 pf_patch_32_unaligned(struct pf_pdesc *pd, void *f, u_int32_t v, bool hi) 2044 { 2045 int rewrite = 0; 2046 u_int8_t *fb = (u_int8_t*)f; 2047 u_int8_t *vb = (u_int8_t*)&v; 2048 2049 if (hi && ALIGNED_POINTER(f, u_int32_t)) { 2050 return (pf_patch_32(pd, f, v)); /* optimise */ 2051 } 2052 2053 rewrite += pf_patch_8(pd, fb++, *vb++, hi); 2054 rewrite += pf_patch_8(pd, fb++, *vb++,!hi); 2055 rewrite += pf_patch_8(pd, fb++, *vb++, hi); 2056 rewrite += pf_patch_8(pd, fb++, *vb++,!hi); 2057 2058 return (rewrite); 2059 } 2060 2061 int 2062 pf_icmp_mapping(struct pf_pdesc *pd, u_int8_t type, int *icmp_dir, 2063 u_int16_t *virtual_id, u_int16_t *virtual_type) 2064 { 2065 /* 2066 * ICMP types marked with PF_OUT are typically responses to 2067 * PF_IN, and will match states in the opposite direction. 2068 * PF_IN ICMP types need to match a state with that type. 2069 */ 2070 *icmp_dir = PF_OUT; 2071 2072 /* Queries (and responses) */ 2073 switch (pd->af) { 2074 case AF_INET: 2075 switch (type) { 2076 case ICMP_ECHO: 2077 *icmp_dir = PF_IN; 2078 /* FALLTHROUGH */ 2079 case ICMP_ECHOREPLY: 2080 *virtual_type = ICMP_ECHO; 2081 *virtual_id = pd->hdr.icmp.icmp_id; 2082 break; 2083 2084 case ICMP_TSTAMP: 2085 *icmp_dir = PF_IN; 2086 /* FALLTHROUGH */ 2087 case ICMP_TSTAMPREPLY: 2088 *virtual_type = ICMP_TSTAMP; 2089 *virtual_id = pd->hdr.icmp.icmp_id; 2090 break; 2091 2092 case ICMP_IREQ: 2093 *icmp_dir = PF_IN; 2094 /* FALLTHROUGH */ 2095 case ICMP_IREQREPLY: 2096 *virtual_type = ICMP_IREQ; 2097 *virtual_id = pd->hdr.icmp.icmp_id; 2098 break; 2099 2100 case ICMP_MASKREQ: 2101 *icmp_dir = PF_IN; 2102 /* FALLTHROUGH */ 2103 case ICMP_MASKREPLY: 2104 *virtual_type = ICMP_MASKREQ; 2105 *virtual_id = pd->hdr.icmp.icmp_id; 2106 break; 2107 2108 case ICMP_IPV6_WHEREAREYOU: 2109 *icmp_dir = PF_IN; 2110 /* FALLTHROUGH */ 2111 case ICMP_IPV6_IAMHERE: 2112 *virtual_type = ICMP_IPV6_WHEREAREYOU; 2113 *virtual_id = 0; /* Nothing sane to match on! */ 2114 break; 2115 2116 case ICMP_MOBILE_REGREQUEST: 2117 *icmp_dir = PF_IN; 2118 /* FALLTHROUGH */ 2119 case ICMP_MOBILE_REGREPLY: 2120 *virtual_type = ICMP_MOBILE_REGREQUEST; 2121 *virtual_id = 0; /* Nothing sane to match on! */ 2122 break; 2123 2124 case ICMP_ROUTERSOLICIT: 2125 *icmp_dir = PF_IN; 2126 /* FALLTHROUGH */ 2127 case ICMP_ROUTERADVERT: 2128 *virtual_type = ICMP_ROUTERSOLICIT; 2129 *virtual_id = 0; /* Nothing sane to match on! */ 2130 break; 2131 2132 /* These ICMP types map to other connections */ 2133 case ICMP_UNREACH: 2134 case ICMP_SOURCEQUENCH: 2135 case ICMP_REDIRECT: 2136 case ICMP_TIMXCEED: 2137 case ICMP_PARAMPROB: 2138 /* These will not be used, but set them anyway */ 2139 *icmp_dir = PF_IN; 2140 *virtual_type = htons(type); 2141 *virtual_id = 0; 2142 return (1); /* These types match to another state */ 2143 2144 /* 2145 * All remaining ICMP types get their own states, 2146 * and will only match in one direction. 2147 */ 2148 default: 2149 *icmp_dir = PF_IN; 2150 *virtual_type = type; 2151 *virtual_id = 0; 2152 break; 2153 } 2154 break; 2155 #ifdef INET6 2156 case AF_INET6: 2157 switch (type) { 2158 case ICMP6_ECHO_REQUEST: 2159 *icmp_dir = PF_IN; 2160 /* FALLTHROUGH */ 2161 case ICMP6_ECHO_REPLY: 2162 *virtual_type = ICMP6_ECHO_REQUEST; 2163 *virtual_id = pd->hdr.icmp6.icmp6_id; 2164 break; 2165 2166 case MLD_LISTENER_QUERY: 2167 case MLD_LISTENER_REPORT: { 2168 struct mld_hdr *mld = &pd->hdr.mld; 2169 u_int32_t h; 2170 2171 /* 2172 * Listener Report can be sent by clients 2173 * without an associated Listener Query. 2174 * In addition to that, when Report is sent as a 2175 * reply to a Query its source and destination 2176 * address are different. 2177 */ 2178 *icmp_dir = PF_IN; 2179 *virtual_type = MLD_LISTENER_QUERY; 2180 /* generate fake id for these messages */ 2181 h = mld->mld_addr.s6_addr32[0] ^ 2182 mld->mld_addr.s6_addr32[1] ^ 2183 mld->mld_addr.s6_addr32[2] ^ 2184 mld->mld_addr.s6_addr32[3]; 2185 *virtual_id = (h >> 16) ^ (h & 0xffff); 2186 break; 2187 } 2188 2189 /* 2190 * ICMP6_FQDN and ICMP6_NI query/reply are the same type as 2191 * ICMP6_WRU 2192 */ 2193 case ICMP6_WRUREQUEST: 2194 *icmp_dir = PF_IN; 2195 /* FALLTHROUGH */ 2196 case ICMP6_WRUREPLY: 2197 *virtual_type = ICMP6_WRUREQUEST; 2198 *virtual_id = 0; /* Nothing sane to match on! */ 2199 break; 2200 2201 case MLD_MTRACE: 2202 *icmp_dir = PF_IN; 2203 /* FALLTHROUGH */ 2204 case MLD_MTRACE_RESP: 2205 *virtual_type = MLD_MTRACE; 2206 *virtual_id = 0; /* Nothing sane to match on! */ 2207 break; 2208 2209 case ND_NEIGHBOR_SOLICIT: 2210 *icmp_dir = PF_IN; 2211 /* FALLTHROUGH */ 2212 case ND_NEIGHBOR_ADVERT: { 2213 struct nd_neighbor_solicit *nd = &pd->hdr.nd_ns; 2214 u_int32_t h; 2215 2216 *virtual_type = ND_NEIGHBOR_SOLICIT; 2217 /* generate fake id for these messages */ 2218 h = nd->nd_ns_target.s6_addr32[0] ^ 2219 nd->nd_ns_target.s6_addr32[1] ^ 2220 nd->nd_ns_target.s6_addr32[2] ^ 2221 nd->nd_ns_target.s6_addr32[3]; 2222 *virtual_id = (h >> 16) ^ (h & 0xffff); 2223 break; 2224 } 2225 2226 /* 2227 * These ICMP types map to other connections. 2228 * ND_REDIRECT can't be in this list because the triggering 2229 * packet header is optional. 2230 */ 2231 case ICMP6_DST_UNREACH: 2232 case ICMP6_PACKET_TOO_BIG: 2233 case ICMP6_TIME_EXCEEDED: 2234 case ICMP6_PARAM_PROB: 2235 /* These will not be used, but set them anyway */ 2236 *icmp_dir = PF_IN; 2237 *virtual_type = htons(type); 2238 *virtual_id = 0; 2239 return (1); /* These types match to another state */ 2240 /* 2241 * All remaining ICMP6 types get their own states, 2242 * and will only match in one direction. 2243 */ 2244 default: 2245 *icmp_dir = PF_IN; 2246 *virtual_type = type; 2247 *virtual_id = 0; 2248 break; 2249 } 2250 break; 2251 #endif /* INET6 */ 2252 } 2253 *virtual_type = htons(*virtual_type); 2254 return (0); /* These types match to their own state */ 2255 } 2256 2257 void 2258 pf_translate_icmp(struct pf_pdesc *pd, struct pf_addr *qa, u_int16_t *qp, 2259 struct pf_addr *oa, struct pf_addr *na, u_int16_t np) 2260 { 2261 /* note: doesn't trouble to fixup quoted checksums, if any */ 2262 2263 /* change quoted protocol port */ 2264 if (qp != NULL) 2265 pf_patch_16(pd, qp, np); 2266 2267 /* change quoted ip address */ 2268 pf_cksum_fixup_a(pd->pcksum, qa, na, pd->af, pd->proto); 2269 pf_addrcpy(qa, na, pd->af); 2270 2271 /* change network-header's ip address */ 2272 if (oa) 2273 pf_translate_a(pd, oa, na); 2274 } 2275 2276 /* pre: *a is 16-bit aligned within its packet */ 2277 /* *a is a network header src/dst address */ 2278 int 2279 pf_translate_a(struct pf_pdesc *pd, struct pf_addr *a, struct pf_addr *an) 2280 { 2281 int rewrite = 0; 2282 2283 /* warning: !PF_ANEQ != PF_AEQ */ 2284 if (!PF_ANEQ(a, an, pd->af)) 2285 return (0); 2286 2287 /* fixup transport pseudo-header, if any */ 2288 switch (pd->proto) { 2289 case IPPROTO_TCP: /* FALLTHROUGH */ 2290 case IPPROTO_UDP: /* FALLTHROUGH */ 2291 case IPPROTO_ICMPV6: 2292 pf_cksum_fixup_a(pd->pcksum, a, an, pd->af, pd->proto); 2293 break; 2294 default: 2295 break; /* assume no pseudo-header */ 2296 } 2297 2298 pf_addrcpy(a, an, pd->af); 2299 rewrite = 1; 2300 2301 return (rewrite); 2302 } 2303 2304 #if INET6 2305 /* pf_translate_af() may change pd->m, adjust local copies after calling */ 2306 int 2307 pf_translate_af(struct pf_pdesc *pd) 2308 { 2309 static const struct pf_addr zero; 2310 struct ip *ip4; 2311 struct ip6_hdr *ip6; 2312 int copyback = 0; 2313 u_int hlen, ohlen, dlen; 2314 u_int16_t *pc; 2315 u_int8_t af_proto, naf_proto; 2316 2317 hlen = (pd->naf == AF_INET) ? sizeof(*ip4) : sizeof(*ip6); 2318 ohlen = pd->off; 2319 dlen = pd->tot_len - pd->off; 2320 pc = pd->pcksum; 2321 2322 af_proto = naf_proto = pd->proto; 2323 if (naf_proto == IPPROTO_ICMP) 2324 af_proto = IPPROTO_ICMPV6; 2325 if (naf_proto == IPPROTO_ICMPV6) 2326 af_proto = IPPROTO_ICMP; 2327 2328 /* uncover stale pseudo-header */ 2329 switch (af_proto) { 2330 case IPPROTO_ICMPV6: 2331 /* optimise: unchanged for TCP/UDP */ 2332 pf_cksum_fixup(pc, htons(af_proto), 0x0, af_proto); 2333 pf_cksum_fixup(pc, htons(dlen), 0x0, af_proto); 2334 /* FALLTHROUGH */ 2335 case IPPROTO_UDP: /* FALLTHROUGH */ 2336 case IPPROTO_TCP: 2337 pf_cksum_fixup_a(pc, pd->src, &zero, pd->af, af_proto); 2338 pf_cksum_fixup_a(pc, pd->dst, &zero, pd->af, af_proto); 2339 copyback = 1; 2340 break; 2341 default: 2342 break; /* assume no pseudo-header */ 2343 } 2344 2345 /* replace the network header */ 2346 m_adj(pd->m, pd->off); 2347 pd->src = NULL; 2348 pd->dst = NULL; 2349 2350 if ((M_PREPEND(pd->m, hlen, M_DONTWAIT)) == NULL) { 2351 pd->m = NULL; 2352 return (-1); 2353 } 2354 2355 pd->off = hlen; 2356 pd->tot_len += hlen - ohlen; 2357 2358 switch (pd->naf) { 2359 case AF_INET: 2360 ip4 = mtod(pd->m, struct ip *); 2361 memset(ip4, 0, hlen); 2362 ip4->ip_v = IPVERSION; 2363 ip4->ip_hl = hlen >> 2; 2364 ip4->ip_tos = pd->tos; 2365 ip4->ip_len = htons(hlen + dlen); 2366 ip4->ip_id = htons(ip_randomid()); 2367 ip4->ip_off = htons(IP_DF); 2368 ip4->ip_ttl = pd->ttl; 2369 ip4->ip_p = pd->proto; 2370 ip4->ip_src = pd->nsaddr.v4; 2371 ip4->ip_dst = pd->ndaddr.v4; 2372 break; 2373 case AF_INET6: 2374 ip6 = mtod(pd->m, struct ip6_hdr *); 2375 memset(ip6, 0, hlen); 2376 ip6->ip6_vfc = IPV6_VERSION; 2377 ip6->ip6_flow |= htonl((u_int32_t)pd->tos << 20); 2378 ip6->ip6_plen = htons(dlen); 2379 ip6->ip6_nxt = pd->proto; 2380 if (!pd->ttl || pd->ttl > IPV6_DEFHLIM) 2381 ip6->ip6_hlim = IPV6_DEFHLIM; 2382 else 2383 ip6->ip6_hlim = pd->ttl; 2384 ip6->ip6_src = pd->nsaddr.v6; 2385 ip6->ip6_dst = pd->ndaddr.v6; 2386 break; 2387 default: 2388 unhandled_af(pd->naf); 2389 } 2390 2391 /* UDP over IPv6 must be checksummed per rfc2460 p27 */ 2392 if (naf_proto == IPPROTO_UDP && *pc == 0x0000 && 2393 pd->naf == AF_INET6) { 2394 pd->m->m_pkthdr.csum_flags |= M_UDP_CSUM_OUT; 2395 } 2396 2397 /* cover fresh pseudo-header */ 2398 switch (naf_proto) { 2399 case IPPROTO_ICMPV6: 2400 /* optimise: unchanged for TCP/UDP */ 2401 pf_cksum_fixup(pc, 0x0, htons(naf_proto), naf_proto); 2402 pf_cksum_fixup(pc, 0x0, htons(dlen), naf_proto); 2403 /* FALLTHROUGH */ 2404 case IPPROTO_UDP: /* FALLTHROUGH */ 2405 case IPPROTO_TCP: 2406 pf_cksum_fixup_a(pc, &zero, &pd->nsaddr, pd->naf, naf_proto); 2407 pf_cksum_fixup_a(pc, &zero, &pd->ndaddr, pd->naf, naf_proto); 2408 copyback = 1; 2409 break; 2410 default: 2411 break; /* assume no pseudo-header */ 2412 } 2413 2414 /* flush pd->pcksum */ 2415 if (copyback) 2416 m_copyback(pd->m, pd->off, pd->hdrlen, &pd->hdr, M_NOWAIT); 2417 2418 return (0); 2419 } 2420 2421 int 2422 pf_change_icmp_af(struct mbuf *m, int ipoff2, struct pf_pdesc *pd, 2423 struct pf_pdesc *pd2, struct pf_addr *src, struct pf_addr *dst, 2424 sa_family_t af, sa_family_t naf) 2425 { 2426 struct mbuf *n = NULL; 2427 struct ip *ip4; 2428 struct ip6_hdr *ip6; 2429 u_int hlen, ohlen, dlen; 2430 int d; 2431 2432 if (af == naf || (af != AF_INET && af != AF_INET6) || 2433 (naf != AF_INET && naf != AF_INET6)) 2434 return (-1); 2435 2436 /* split the mbuf chain on the quoted ip/ip6 header boundary */ 2437 if ((n = m_split(m, ipoff2, M_DONTWAIT)) == NULL) 2438 return (-1); 2439 2440 /* new quoted header */ 2441 hlen = naf == AF_INET ? sizeof(*ip4) : sizeof(*ip6); 2442 /* old quoted header */ 2443 ohlen = pd2->off - ipoff2; 2444 2445 /* trim old quoted header */ 2446 pf_cksum_uncover(pd->pcksum, in_cksum(n, ohlen), pd->proto); 2447 m_adj(n, ohlen); 2448 2449 /* prepend a new, translated, quoted header */ 2450 if ((M_PREPEND(n, hlen, M_DONTWAIT)) == NULL) 2451 return (-1); 2452 2453 switch (naf) { 2454 case AF_INET: 2455 ip4 = mtod(n, struct ip *); 2456 memset(ip4, 0, sizeof(*ip4)); 2457 ip4->ip_v = IPVERSION; 2458 ip4->ip_hl = sizeof(*ip4) >> 2; 2459 ip4->ip_len = htons(sizeof(*ip4) + pd2->tot_len - ohlen); 2460 ip4->ip_id = htons(ip_randomid()); 2461 ip4->ip_off = htons(IP_DF); 2462 ip4->ip_ttl = pd2->ttl; 2463 if (pd2->proto == IPPROTO_ICMPV6) 2464 ip4->ip_p = IPPROTO_ICMP; 2465 else 2466 ip4->ip_p = pd2->proto; 2467 ip4->ip_src = src->v4; 2468 ip4->ip_dst = dst->v4; 2469 ip4->ip_sum = in_cksum(n, ip4->ip_hl << 2); 2470 break; 2471 case AF_INET6: 2472 ip6 = mtod(n, struct ip6_hdr *); 2473 memset(ip6, 0, sizeof(*ip6)); 2474 ip6->ip6_vfc = IPV6_VERSION; 2475 ip6->ip6_plen = htons(pd2->tot_len - ohlen); 2476 if (pd2->proto == IPPROTO_ICMP) 2477 ip6->ip6_nxt = IPPROTO_ICMPV6; 2478 else 2479 ip6->ip6_nxt = pd2->proto; 2480 if (!pd2->ttl || pd2->ttl > IPV6_DEFHLIM) 2481 ip6->ip6_hlim = IPV6_DEFHLIM; 2482 else 2483 ip6->ip6_hlim = pd2->ttl; 2484 ip6->ip6_src = src->v6; 2485 ip6->ip6_dst = dst->v6; 2486 break; 2487 } 2488 2489 /* cover new quoted header */ 2490 /* optimise: any new AF_INET header of ours sums to zero */ 2491 if (naf != AF_INET) { 2492 pf_cksum_cover(pd->pcksum, in_cksum(n, hlen), pd->proto); 2493 } 2494 2495 /* reattach modified quoted packet to outer header */ 2496 { 2497 int nlen = n->m_pkthdr.len; 2498 m_cat(m, n); 2499 m->m_pkthdr.len += nlen; 2500 } 2501 2502 /* account for altered length */ 2503 d = hlen - ohlen; 2504 2505 if (pd->proto == IPPROTO_ICMPV6) { 2506 /* fixup pseudo-header */ 2507 dlen = pd->tot_len - pd->off; 2508 pf_cksum_fixup(pd->pcksum, 2509 htons(dlen), htons(dlen + d), pd->proto); 2510 } 2511 2512 pd->tot_len += d; 2513 pd2->tot_len += d; 2514 pd2->off += d; 2515 2516 /* note: not bothering to update network headers as 2517 these due for rewrite by pf_translate_af() */ 2518 2519 return (0); 2520 } 2521 2522 2523 #define PTR_IP(field) (offsetof(struct ip, field)) 2524 #define PTR_IP6(field) (offsetof(struct ip6_hdr, field)) 2525 2526 int 2527 pf_translate_icmp_af(struct pf_pdesc *pd, int af, void *arg) 2528 { 2529 struct icmp *icmp4; 2530 struct icmp6_hdr *icmp6; 2531 u_int32_t mtu; 2532 int32_t ptr = -1; 2533 u_int8_t type; 2534 u_int8_t code; 2535 2536 switch (af) { 2537 case AF_INET: 2538 icmp6 = arg; 2539 type = icmp6->icmp6_type; 2540 code = icmp6->icmp6_code; 2541 mtu = ntohl(icmp6->icmp6_mtu); 2542 2543 switch (type) { 2544 case ICMP6_ECHO_REQUEST: 2545 type = ICMP_ECHO; 2546 break; 2547 case ICMP6_ECHO_REPLY: 2548 type = ICMP_ECHOREPLY; 2549 break; 2550 case ICMP6_DST_UNREACH: 2551 type = ICMP_UNREACH; 2552 switch (code) { 2553 case ICMP6_DST_UNREACH_NOROUTE: 2554 case ICMP6_DST_UNREACH_BEYONDSCOPE: 2555 case ICMP6_DST_UNREACH_ADDR: 2556 code = ICMP_UNREACH_HOST; 2557 break; 2558 case ICMP6_DST_UNREACH_ADMIN: 2559 code = ICMP_UNREACH_HOST_PROHIB; 2560 break; 2561 case ICMP6_DST_UNREACH_NOPORT: 2562 code = ICMP_UNREACH_PORT; 2563 break; 2564 default: 2565 return (-1); 2566 } 2567 break; 2568 case ICMP6_PACKET_TOO_BIG: 2569 type = ICMP_UNREACH; 2570 code = ICMP_UNREACH_NEEDFRAG; 2571 mtu -= 20; 2572 break; 2573 case ICMP6_TIME_EXCEEDED: 2574 type = ICMP_TIMXCEED; 2575 break; 2576 case ICMP6_PARAM_PROB: 2577 switch (code) { 2578 case ICMP6_PARAMPROB_HEADER: 2579 type = ICMP_PARAMPROB; 2580 code = ICMP_PARAMPROB_ERRATPTR; 2581 ptr = ntohl(icmp6->icmp6_pptr); 2582 2583 if (ptr == PTR_IP6(ip6_vfc)) 2584 ; /* preserve */ 2585 else if (ptr == PTR_IP6(ip6_vfc) + 1) 2586 ptr = PTR_IP(ip_tos); 2587 else if (ptr == PTR_IP6(ip6_plen) || 2588 ptr == PTR_IP6(ip6_plen) + 1) 2589 ptr = PTR_IP(ip_len); 2590 else if (ptr == PTR_IP6(ip6_nxt)) 2591 ptr = PTR_IP(ip_p); 2592 else if (ptr == PTR_IP6(ip6_hlim)) 2593 ptr = PTR_IP(ip_ttl); 2594 else if (ptr >= PTR_IP6(ip6_src) && 2595 ptr < PTR_IP6(ip6_dst)) 2596 ptr = PTR_IP(ip_src); 2597 else if (ptr >= PTR_IP6(ip6_dst) && 2598 ptr < sizeof(struct ip6_hdr)) 2599 ptr = PTR_IP(ip_dst); 2600 else { 2601 return (-1); 2602 } 2603 break; 2604 case ICMP6_PARAMPROB_NEXTHEADER: 2605 type = ICMP_UNREACH; 2606 code = ICMP_UNREACH_PROTOCOL; 2607 break; 2608 default: 2609 return (-1); 2610 } 2611 break; 2612 default: 2613 return (-1); 2614 } 2615 2616 pf_patch_8(pd, &icmp6->icmp6_type, type, PF_HI); 2617 pf_patch_8(pd, &icmp6->icmp6_code, code, PF_LO); 2618 2619 /* aligns well with a icmpv4 nextmtu */ 2620 pf_patch_32(pd, &icmp6->icmp6_mtu, htonl(mtu)); 2621 2622 /* icmpv4 pptr is a one most significant byte */ 2623 if (ptr >= 0) 2624 pf_patch_32(pd, &icmp6->icmp6_pptr, htonl(ptr << 24)); 2625 break; 2626 case AF_INET6: 2627 icmp4 = arg; 2628 type = icmp4->icmp_type; 2629 code = icmp4->icmp_code; 2630 mtu = ntohs(icmp4->icmp_nextmtu); 2631 2632 switch (type) { 2633 case ICMP_ECHO: 2634 type = ICMP6_ECHO_REQUEST; 2635 break; 2636 case ICMP_ECHOREPLY: 2637 type = ICMP6_ECHO_REPLY; 2638 break; 2639 case ICMP_UNREACH: 2640 type = ICMP6_DST_UNREACH; 2641 switch (code) { 2642 case ICMP_UNREACH_NET: 2643 case ICMP_UNREACH_HOST: 2644 case ICMP_UNREACH_NET_UNKNOWN: 2645 case ICMP_UNREACH_HOST_UNKNOWN: 2646 case ICMP_UNREACH_ISOLATED: 2647 case ICMP_UNREACH_TOSNET: 2648 case ICMP_UNREACH_TOSHOST: 2649 code = ICMP6_DST_UNREACH_NOROUTE; 2650 break; 2651 case ICMP_UNREACH_PORT: 2652 code = ICMP6_DST_UNREACH_NOPORT; 2653 break; 2654 case ICMP_UNREACH_NET_PROHIB: 2655 case ICMP_UNREACH_HOST_PROHIB: 2656 case ICMP_UNREACH_FILTER_PROHIB: 2657 case ICMP_UNREACH_PRECEDENCE_CUTOFF: 2658 code = ICMP6_DST_UNREACH_ADMIN; 2659 break; 2660 case ICMP_UNREACH_PROTOCOL: 2661 type = ICMP6_PARAM_PROB; 2662 code = ICMP6_PARAMPROB_NEXTHEADER; 2663 ptr = offsetof(struct ip6_hdr, ip6_nxt); 2664 break; 2665 case ICMP_UNREACH_NEEDFRAG: 2666 type = ICMP6_PACKET_TOO_BIG; 2667 code = 0; 2668 mtu += 20; 2669 break; 2670 default: 2671 return (-1); 2672 } 2673 break; 2674 case ICMP_TIMXCEED: 2675 type = ICMP6_TIME_EXCEEDED; 2676 break; 2677 case ICMP_PARAMPROB: 2678 type = ICMP6_PARAM_PROB; 2679 switch (code) { 2680 case ICMP_PARAMPROB_ERRATPTR: 2681 code = ICMP6_PARAMPROB_HEADER; 2682 break; 2683 case ICMP_PARAMPROB_LENGTH: 2684 code = ICMP6_PARAMPROB_HEADER; 2685 break; 2686 default: 2687 return (-1); 2688 } 2689 2690 ptr = icmp4->icmp_pptr; 2691 if (ptr == 0 || ptr == PTR_IP(ip_tos)) 2692 ; /* preserve */ 2693 else if (ptr == PTR_IP(ip_len) || 2694 ptr == PTR_IP(ip_len) + 1) 2695 ptr = PTR_IP6(ip6_plen); 2696 else if (ptr == PTR_IP(ip_ttl)) 2697 ptr = PTR_IP6(ip6_hlim); 2698 else if (ptr == PTR_IP(ip_p)) 2699 ptr = PTR_IP6(ip6_nxt); 2700 else if (ptr >= PTR_IP(ip_src) && 2701 ptr < PTR_IP(ip_dst)) 2702 ptr = PTR_IP6(ip6_src); 2703 else if (ptr >= PTR_IP(ip_dst) && 2704 ptr < sizeof(struct ip)) 2705 ptr = PTR_IP6(ip6_dst); 2706 else { 2707 return (-1); 2708 } 2709 break; 2710 default: 2711 return (-1); 2712 } 2713 2714 pf_patch_8(pd, &icmp4->icmp_type, type, PF_HI); 2715 pf_patch_8(pd, &icmp4->icmp_code, code, PF_LO); 2716 pf_patch_16(pd, &icmp4->icmp_nextmtu, htons(mtu)); 2717 if (ptr >= 0) 2718 pf_patch_32(pd, &icmp4->icmp_void, htonl(ptr)); 2719 break; 2720 } 2721 2722 return (0); 2723 } 2724 #endif /* INET6 */ 2725 2726 /* 2727 * Need to modulate the sequence numbers in the TCP SACK option 2728 * (credits to Krzysztof Pfaff for report and patch) 2729 */ 2730 int 2731 pf_modulate_sack(struct pf_pdesc *pd, struct pf_state_peer *dst) 2732 { 2733 struct sackblk sack; 2734 int copyback = 0, i; 2735 int olen, optsoff; 2736 u_int8_t opts[MAX_TCPOPTLEN], *opt, *eoh; 2737 2738 olen = (pd->hdr.tcp.th_off << 2) - sizeof(struct tcphdr); 2739 optsoff = pd->off + sizeof(struct tcphdr); 2740 #define TCPOLEN_MINSACK (TCPOLEN_SACK + 2) 2741 if (olen < TCPOLEN_MINSACK || 2742 !pf_pull_hdr(pd->m, optsoff, opts, olen, NULL, NULL, pd->af)) 2743 return (0); 2744 2745 eoh = opts + olen; 2746 opt = opts; 2747 while ((opt = pf_find_tcpopt(opt, opts, olen, 2748 TCPOPT_SACK, TCPOLEN_MINSACK)) != NULL) 2749 { 2750 size_t safelen = MIN(opt[1], (eoh - opt)); 2751 for (i = 2; i + TCPOLEN_SACK <= safelen; i += TCPOLEN_SACK) { 2752 size_t startoff = (opt + i) - opts; 2753 memcpy(&sack, &opt[i], sizeof(sack)); 2754 pf_patch_32_unaligned(pd, &sack.start, 2755 htonl(ntohl(sack.start) - dst->seqdiff), 2756 PF_ALGNMNT(startoff)); 2757 pf_patch_32_unaligned(pd, &sack.end, 2758 htonl(ntohl(sack.end) - dst->seqdiff), 2759 PF_ALGNMNT(startoff + sizeof(sack.start))); 2760 memcpy(&opt[i], &sack, sizeof(sack)); 2761 } 2762 copyback = 1; 2763 opt += opt[1]; 2764 } 2765 2766 if (copyback) 2767 m_copyback(pd->m, optsoff, olen, opts, M_NOWAIT); 2768 return (copyback); 2769 } 2770 2771 struct mbuf * 2772 pf_build_tcp(const struct pf_rule *r, sa_family_t af, 2773 const struct pf_addr *saddr, const struct pf_addr *daddr, 2774 u_int16_t sport, u_int16_t dport, u_int32_t seq, u_int32_t ack, 2775 u_int8_t flags, u_int16_t win, u_int16_t mss, u_int8_t ttl, int tag, 2776 u_int16_t rtag, u_int sack, u_int rdom) 2777 { 2778 struct mbuf *m; 2779 int len, tlen; 2780 struct ip *h; 2781 #ifdef INET6 2782 struct ip6_hdr *h6; 2783 #endif /* INET6 */ 2784 struct tcphdr *th; 2785 char *opt; 2786 2787 /* maximum segment size tcp option */ 2788 tlen = sizeof(struct tcphdr); 2789 if (mss) 2790 tlen += 4; 2791 if (sack) 2792 tlen += 2; 2793 2794 switch (af) { 2795 case AF_INET: 2796 len = sizeof(struct ip) + tlen; 2797 break; 2798 #ifdef INET6 2799 case AF_INET6: 2800 len = sizeof(struct ip6_hdr) + tlen; 2801 break; 2802 #endif /* INET6 */ 2803 default: 2804 unhandled_af(af); 2805 } 2806 2807 /* create outgoing mbuf */ 2808 m = m_gethdr(M_DONTWAIT, MT_HEADER); 2809 if (m == NULL) 2810 return (NULL); 2811 if (tag) 2812 m->m_pkthdr.pf.flags |= PF_TAG_GENERATED; 2813 m->m_pkthdr.pf.tag = rtag; 2814 m->m_pkthdr.ph_rtableid = rdom; 2815 if (r && (r->scrub_flags & PFSTATE_SETPRIO)) 2816 m->m_pkthdr.pf.prio = r->set_prio[0]; 2817 if (r && r->qid) 2818 m->m_pkthdr.pf.qid = r->qid; 2819 m->m_data += max_linkhdr; 2820 m->m_pkthdr.len = m->m_len = len; 2821 m->m_pkthdr.ph_ifidx = 0; 2822 m->m_pkthdr.csum_flags |= M_TCP_CSUM_OUT; 2823 memset(m->m_data, 0, len); 2824 switch (af) { 2825 case AF_INET: 2826 h = mtod(m, struct ip *); 2827 h->ip_p = IPPROTO_TCP; 2828 h->ip_len = htons(tlen); 2829 h->ip_v = 4; 2830 h->ip_hl = sizeof(*h) >> 2; 2831 h->ip_tos = IPTOS_LOWDELAY; 2832 h->ip_len = htons(len); 2833 h->ip_off = htons(ip_mtudisc ? IP_DF : 0); 2834 h->ip_ttl = ttl ? ttl : ip_defttl; 2835 h->ip_sum = 0; 2836 h->ip_src.s_addr = saddr->v4.s_addr; 2837 h->ip_dst.s_addr = daddr->v4.s_addr; 2838 2839 th = (struct tcphdr *)((caddr_t)h + sizeof(struct ip)); 2840 break; 2841 #ifdef INET6 2842 case AF_INET6: 2843 h6 = mtod(m, struct ip6_hdr *); 2844 h6->ip6_nxt = IPPROTO_TCP; 2845 h6->ip6_plen = htons(tlen); 2846 h6->ip6_vfc |= IPV6_VERSION; 2847 h6->ip6_hlim = IPV6_DEFHLIM; 2848 memcpy(&h6->ip6_src, &saddr->v6, sizeof(struct in6_addr)); 2849 memcpy(&h6->ip6_dst, &daddr->v6, sizeof(struct in6_addr)); 2850 2851 th = (struct tcphdr *)((caddr_t)h6 + sizeof(struct ip6_hdr)); 2852 break; 2853 #endif /* INET6 */ 2854 default: 2855 unhandled_af(af); 2856 } 2857 2858 /* TCP header */ 2859 th->th_sport = sport; 2860 th->th_dport = dport; 2861 th->th_seq = htonl(seq); 2862 th->th_ack = htonl(ack); 2863 th->th_off = tlen >> 2; 2864 th->th_flags = flags; 2865 th->th_win = htons(win); 2866 2867 opt = (char *)(th + 1); 2868 if (mss) { 2869 opt[0] = TCPOPT_MAXSEG; 2870 opt[1] = 4; 2871 mss = htons(mss); 2872 memcpy((opt + 2), &mss, 2); 2873 opt += 4; 2874 } 2875 if (sack) { 2876 opt[0] = TCPOPT_SACK_PERMITTED; 2877 opt[1] = 2; 2878 opt += 2; 2879 } 2880 2881 return (m); 2882 } 2883 2884 void 2885 pf_send_tcp(const struct pf_rule *r, sa_family_t af, 2886 const struct pf_addr *saddr, const struct pf_addr *daddr, 2887 u_int16_t sport, u_int16_t dport, u_int32_t seq, u_int32_t ack, 2888 u_int8_t flags, u_int16_t win, u_int16_t mss, u_int8_t ttl, int tag, 2889 u_int16_t rtag, u_int rdom) 2890 { 2891 struct mbuf *m; 2892 2893 if ((m = pf_build_tcp(r, af, saddr, daddr, sport, dport, seq, ack, 2894 flags, win, mss, ttl, tag, rtag, 0, rdom)) == NULL) 2895 return; 2896 2897 switch (af) { 2898 case AF_INET: 2899 ip_send(m); 2900 break; 2901 #ifdef INET6 2902 case AF_INET6: 2903 ip6_send(m); 2904 break; 2905 #endif /* INET6 */ 2906 } 2907 } 2908 2909 static void 2910 pf_send_challenge_ack(struct pf_pdesc *pd, struct pf_state *s, 2911 struct pf_state_peer *src, struct pf_state_peer *dst) 2912 { 2913 /* 2914 * We are sending challenge ACK as a response to SYN packet, which 2915 * matches existing state (modulo TCP window check). Therefore packet 2916 * must be sent on behalf of destination. 2917 * 2918 * We expect sender to remain either silent, or send RST packet 2919 * so both, firewall and remote peer, can purge dead state from 2920 * memory. 2921 */ 2922 pf_send_tcp(s->rule.ptr, pd->af, pd->dst, pd->src, 2923 pd->hdr.tcp.th_dport, pd->hdr.tcp.th_sport, dst->seqlo, 2924 src->seqlo, TH_ACK, 0, 0, s->rule.ptr->return_ttl, 1, 0, 2925 pd->rdomain); 2926 } 2927 2928 void 2929 pf_send_icmp(struct mbuf *m, u_int8_t type, u_int8_t code, int param, 2930 sa_family_t af, struct pf_rule *r, u_int rdomain) 2931 { 2932 struct mbuf *m0; 2933 2934 if ((m0 = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) 2935 return; 2936 2937 m0->m_pkthdr.pf.flags |= PF_TAG_GENERATED; 2938 m0->m_pkthdr.ph_rtableid = rdomain; 2939 if (r && (r->scrub_flags & PFSTATE_SETPRIO)) 2940 m0->m_pkthdr.pf.prio = r->set_prio[0]; 2941 if (r && r->qid) 2942 m0->m_pkthdr.pf.qid = r->qid; 2943 2944 switch (af) { 2945 case AF_INET: 2946 icmp_error(m0, type, code, 0, param); 2947 break; 2948 #ifdef INET6 2949 case AF_INET6: 2950 icmp6_error(m0, type, code, param); 2951 break; 2952 #endif /* INET6 */ 2953 } 2954 } 2955 2956 /* 2957 * Return ((n = 0) == (a = b [with mask m])) 2958 * Note: n != 0 => returns (a != b [with mask m]) 2959 */ 2960 int 2961 pf_match_addr(u_int8_t n, struct pf_addr *a, struct pf_addr *m, 2962 struct pf_addr *b, sa_family_t af) 2963 { 2964 switch (af) { 2965 case AF_INET: 2966 if ((a->addr32[0] & m->addr32[0]) == 2967 (b->addr32[0] & m->addr32[0])) 2968 return (n == 0); 2969 break; 2970 #ifdef INET6 2971 case AF_INET6: 2972 if (((a->addr32[0] & m->addr32[0]) == 2973 (b->addr32[0] & m->addr32[0])) && 2974 ((a->addr32[1] & m->addr32[1]) == 2975 (b->addr32[1] & m->addr32[1])) && 2976 ((a->addr32[2] & m->addr32[2]) == 2977 (b->addr32[2] & m->addr32[2])) && 2978 ((a->addr32[3] & m->addr32[3]) == 2979 (b->addr32[3] & m->addr32[3]))) 2980 return (n == 0); 2981 break; 2982 #endif /* INET6 */ 2983 } 2984 2985 return (n != 0); 2986 } 2987 2988 /* 2989 * Return 1 if b <= a <= e, otherwise return 0. 2990 */ 2991 int 2992 pf_match_addr_range(struct pf_addr *b, struct pf_addr *e, 2993 struct pf_addr *a, sa_family_t af) 2994 { 2995 switch (af) { 2996 case AF_INET: 2997 if ((ntohl(a->addr32[0]) < ntohl(b->addr32[0])) || 2998 (ntohl(a->addr32[0]) > ntohl(e->addr32[0]))) 2999 return (0); 3000 break; 3001 #ifdef INET6 3002 case AF_INET6: { 3003 int i; 3004 3005 /* check a >= b */ 3006 for (i = 0; i < 4; ++i) 3007 if (ntohl(a->addr32[i]) > ntohl(b->addr32[i])) 3008 break; 3009 else if (ntohl(a->addr32[i]) < ntohl(b->addr32[i])) 3010 return (0); 3011 /* check a <= e */ 3012 for (i = 0; i < 4; ++i) 3013 if (ntohl(a->addr32[i]) < ntohl(e->addr32[i])) 3014 break; 3015 else if (ntohl(a->addr32[i]) > ntohl(e->addr32[i])) 3016 return (0); 3017 break; 3018 } 3019 #endif /* INET6 */ 3020 } 3021 return (1); 3022 } 3023 3024 int 3025 pf_match(u_int8_t op, u_int32_t a1, u_int32_t a2, u_int32_t p) 3026 { 3027 switch (op) { 3028 case PF_OP_IRG: 3029 return ((p > a1) && (p < a2)); 3030 case PF_OP_XRG: 3031 return ((p < a1) || (p > a2)); 3032 case PF_OP_RRG: 3033 return ((p >= a1) && (p <= a2)); 3034 case PF_OP_EQ: 3035 return (p == a1); 3036 case PF_OP_NE: 3037 return (p != a1); 3038 case PF_OP_LT: 3039 return (p < a1); 3040 case PF_OP_LE: 3041 return (p <= a1); 3042 case PF_OP_GT: 3043 return (p > a1); 3044 case PF_OP_GE: 3045 return (p >= a1); 3046 } 3047 return (0); /* never reached */ 3048 } 3049 3050 int 3051 pf_match_port(u_int8_t op, u_int16_t a1, u_int16_t a2, u_int16_t p) 3052 { 3053 return (pf_match(op, ntohs(a1), ntohs(a2), ntohs(p))); 3054 } 3055 3056 int 3057 pf_match_uid(u_int8_t op, uid_t a1, uid_t a2, uid_t u) 3058 { 3059 if (u == -1 && op != PF_OP_EQ && op != PF_OP_NE) 3060 return (0); 3061 return (pf_match(op, a1, a2, u)); 3062 } 3063 3064 int 3065 pf_match_gid(u_int8_t op, gid_t a1, gid_t a2, gid_t g) 3066 { 3067 if (g == -1 && op != PF_OP_EQ && op != PF_OP_NE) 3068 return (0); 3069 return (pf_match(op, a1, a2, g)); 3070 } 3071 3072 int 3073 pf_match_tag(struct mbuf *m, struct pf_rule *r, int *tag) 3074 { 3075 if (*tag == -1) 3076 *tag = m->m_pkthdr.pf.tag; 3077 3078 return ((!r->match_tag_not && r->match_tag == *tag) || 3079 (r->match_tag_not && r->match_tag != *tag)); 3080 } 3081 3082 int 3083 pf_match_rcvif(struct mbuf *m, struct pf_rule *r) 3084 { 3085 struct ifnet *ifp; 3086 #if NCARP > 0 3087 struct ifnet *ifp0; 3088 #endif 3089 struct pfi_kif *kif; 3090 3091 ifp = if_get(m->m_pkthdr.ph_ifidx); 3092 if (ifp == NULL) 3093 return (0); 3094 3095 #if NCARP > 0 3096 if (ifp->if_type == IFT_CARP && 3097 (ifp0 = if_get(ifp->if_carpdevidx)) != NULL) { 3098 kif = (struct pfi_kif *)ifp0->if_pf_kif; 3099 if_put(ifp0); 3100 } else 3101 #endif /* NCARP */ 3102 kif = (struct pfi_kif *)ifp->if_pf_kif; 3103 3104 if_put(ifp); 3105 3106 if (kif == NULL) { 3107 DPFPRINTF(LOG_ERR, 3108 "%s: kif == NULL, @%d via %s", __func__, 3109 r->nr, r->rcv_ifname); 3110 return (0); 3111 } 3112 3113 return (pfi_kif_match(r->rcv_kif, kif)); 3114 } 3115 3116 void 3117 pf_tag_packet(struct mbuf *m, int tag, int rtableid) 3118 { 3119 if (tag > 0) 3120 m->m_pkthdr.pf.tag = tag; 3121 if (rtableid >= 0) 3122 m->m_pkthdr.ph_rtableid = (u_int)rtableid; 3123 } 3124 3125 enum pf_test_status 3126 pf_step_into_anchor(struct pf_test_ctx *ctx, struct pf_rule *r) 3127 { 3128 int rv; 3129 3130 if (ctx->depth >= PF_ANCHOR_STACK_MAX) { 3131 log(LOG_ERR, "pf_step_into_anchor: stack overflow\n"); 3132 return (PF_TEST_FAIL); 3133 } 3134 3135 ctx->depth++; 3136 3137 if (r->anchor_wildcard) { 3138 struct pf_anchor *child; 3139 rv = PF_TEST_OK; 3140 RB_FOREACH(child, pf_anchor_node, &r->anchor->children) { 3141 rv = pf_match_rule(ctx, &child->ruleset); 3142 if ((rv == PF_TEST_QUICK) || (rv == PF_TEST_FAIL)) { 3143 /* 3144 * we either hit a rule with quick action 3145 * (more likely), or hit some runtime 3146 * error (e.g. pool_get() failure). 3147 */ 3148 break; 3149 } 3150 } 3151 } else { 3152 rv = pf_match_rule(ctx, &r->anchor->ruleset); 3153 /* 3154 * Unless errors occurred, stop iff any rule matched 3155 * within quick anchors. 3156 */ 3157 if (rv != PF_TEST_FAIL && r->quick == PF_TEST_QUICK && 3158 *ctx->am == r) 3159 rv = PF_TEST_QUICK; 3160 } 3161 3162 ctx->depth--; 3163 3164 return (rv); 3165 } 3166 3167 void 3168 pf_poolmask(struct pf_addr *naddr, struct pf_addr *raddr, 3169 struct pf_addr *rmask, struct pf_addr *saddr, sa_family_t af) 3170 { 3171 switch (af) { 3172 case AF_INET: 3173 naddr->addr32[0] = (raddr->addr32[0] & rmask->addr32[0]) | 3174 ((rmask->addr32[0] ^ 0xffffffff ) & saddr->addr32[0]); 3175 break; 3176 #ifdef INET6 3177 case AF_INET6: 3178 naddr->addr32[0] = (raddr->addr32[0] & rmask->addr32[0]) | 3179 ((rmask->addr32[0] ^ 0xffffffff ) & saddr->addr32[0]); 3180 naddr->addr32[1] = (raddr->addr32[1] & rmask->addr32[1]) | 3181 ((rmask->addr32[1] ^ 0xffffffff ) & saddr->addr32[1]); 3182 naddr->addr32[2] = (raddr->addr32[2] & rmask->addr32[2]) | 3183 ((rmask->addr32[2] ^ 0xffffffff ) & saddr->addr32[2]); 3184 naddr->addr32[3] = (raddr->addr32[3] & rmask->addr32[3]) | 3185 ((rmask->addr32[3] ^ 0xffffffff ) & saddr->addr32[3]); 3186 break; 3187 #endif /* INET6 */ 3188 default: 3189 unhandled_af(af); 3190 } 3191 } 3192 3193 void 3194 pf_addr_inc(struct pf_addr *addr, sa_family_t af) 3195 { 3196 switch (af) { 3197 case AF_INET: 3198 addr->addr32[0] = htonl(ntohl(addr->addr32[0]) + 1); 3199 break; 3200 #ifdef INET6 3201 case AF_INET6: 3202 if (addr->addr32[3] == 0xffffffff) { 3203 addr->addr32[3] = 0; 3204 if (addr->addr32[2] == 0xffffffff) { 3205 addr->addr32[2] = 0; 3206 if (addr->addr32[1] == 0xffffffff) { 3207 addr->addr32[1] = 0; 3208 addr->addr32[0] = 3209 htonl(ntohl(addr->addr32[0]) + 1); 3210 } else 3211 addr->addr32[1] = 3212 htonl(ntohl(addr->addr32[1]) + 1); 3213 } else 3214 addr->addr32[2] = 3215 htonl(ntohl(addr->addr32[2]) + 1); 3216 } else 3217 addr->addr32[3] = 3218 htonl(ntohl(addr->addr32[3]) + 1); 3219 break; 3220 #endif /* INET6 */ 3221 default: 3222 unhandled_af(af); 3223 } 3224 } 3225 3226 int 3227 pf_socket_lookup(struct pf_pdesc *pd) 3228 { 3229 struct pf_addr *saddr, *daddr; 3230 u_int16_t sport, dport; 3231 struct inpcbtable *tb; 3232 struct inpcb *inp; 3233 3234 pd->lookup.uid = -1; 3235 pd->lookup.gid = -1; 3236 pd->lookup.pid = NO_PID; 3237 switch (pd->virtual_proto) { 3238 case IPPROTO_TCP: 3239 sport = pd->hdr.tcp.th_sport; 3240 dport = pd->hdr.tcp.th_dport; 3241 PF_ASSERT_LOCKED(); 3242 NET_ASSERT_LOCKED(); 3243 tb = &tcbtable; 3244 break; 3245 case IPPROTO_UDP: 3246 sport = pd->hdr.udp.uh_sport; 3247 dport = pd->hdr.udp.uh_dport; 3248 PF_ASSERT_LOCKED(); 3249 NET_ASSERT_LOCKED(); 3250 tb = &udbtable; 3251 break; 3252 default: 3253 return (-1); 3254 } 3255 if (pd->dir == PF_IN) { 3256 saddr = pd->src; 3257 daddr = pd->dst; 3258 } else { 3259 u_int16_t p; 3260 3261 p = sport; 3262 sport = dport; 3263 dport = p; 3264 saddr = pd->dst; 3265 daddr = pd->src; 3266 } 3267 switch (pd->af) { 3268 case AF_INET: 3269 /* 3270 * Fails when rtable is changed while evaluating the ruleset 3271 * The socket looked up will not match the one hit in the end. 3272 */ 3273 inp = in_pcbhashlookup(tb, saddr->v4, sport, daddr->v4, dport, 3274 pd->rdomain); 3275 if (inp == NULL) { 3276 inp = in_pcblookup_listen(tb, daddr->v4, dport, 3277 NULL, pd->rdomain); 3278 if (inp == NULL) 3279 return (-1); 3280 } 3281 break; 3282 #ifdef INET6 3283 case AF_INET6: 3284 inp = in6_pcbhashlookup(tb, &saddr->v6, sport, &daddr->v6, 3285 dport, pd->rdomain); 3286 if (inp == NULL) { 3287 inp = in6_pcblookup_listen(tb, &daddr->v6, dport, 3288 NULL, pd->rdomain); 3289 if (inp == NULL) 3290 return (-1); 3291 } 3292 break; 3293 #endif /* INET6 */ 3294 default: 3295 unhandled_af(pd->af); 3296 } 3297 pd->lookup.uid = inp->inp_socket->so_euid; 3298 pd->lookup.gid = inp->inp_socket->so_egid; 3299 pd->lookup.pid = inp->inp_socket->so_cpid; 3300 return (1); 3301 } 3302 3303 /* post: r => (r[0] == type /\ r[1] >= min_typelen >= 2 "validity" 3304 * /\ (eoh - r) >= min_typelen >= 2 "safety" ) 3305 * 3306 * warning: r + r[1] may exceed opts bounds for r[1] > min_typelen 3307 */ 3308 u_int8_t* 3309 pf_find_tcpopt(u_int8_t *opt, u_int8_t *opts, size_t hlen, u_int8_t type, 3310 u_int8_t min_typelen) 3311 { 3312 u_int8_t *eoh = opts + hlen; 3313 3314 if (min_typelen < 2) 3315 return (NULL); 3316 3317 while ((eoh - opt) >= min_typelen) { 3318 switch (*opt) { 3319 case TCPOPT_EOL: 3320 /* FALLTHROUGH - Workaround the failure of some 3321 systems to NOP-pad their bzero'd option buffers, 3322 producing spurious EOLs */ 3323 case TCPOPT_NOP: 3324 opt++; 3325 continue; 3326 default: 3327 if (opt[0] == type && 3328 opt[1] >= min_typelen) 3329 return (opt); 3330 } 3331 3332 opt += MAX(opt[1], 2); /* evade infinite loops */ 3333 } 3334 3335 return (NULL); 3336 } 3337 3338 u_int8_t 3339 pf_get_wscale(struct pf_pdesc *pd) 3340 { 3341 int olen; 3342 u_int8_t opts[MAX_TCPOPTLEN], *opt; 3343 u_int8_t wscale = 0; 3344 3345 olen = (pd->hdr.tcp.th_off << 2) - sizeof(struct tcphdr); 3346 if (olen < TCPOLEN_WINDOW || !pf_pull_hdr(pd->m, 3347 pd->off + sizeof(struct tcphdr), opts, olen, NULL, NULL, pd->af)) 3348 return (0); 3349 3350 opt = opts; 3351 while ((opt = pf_find_tcpopt(opt, opts, olen, 3352 TCPOPT_WINDOW, TCPOLEN_WINDOW)) != NULL) { 3353 wscale = opt[2]; 3354 wscale = MIN(wscale, TCP_MAX_WINSHIFT); 3355 wscale |= PF_WSCALE_FLAG; 3356 3357 opt += opt[1]; 3358 } 3359 3360 return (wscale); 3361 } 3362 3363 u_int16_t 3364 pf_get_mss(struct pf_pdesc *pd) 3365 { 3366 int olen; 3367 u_int8_t opts[MAX_TCPOPTLEN], *opt; 3368 u_int16_t mss = tcp_mssdflt; 3369 3370 olen = (pd->hdr.tcp.th_off << 2) - sizeof(struct tcphdr); 3371 if (olen < TCPOLEN_MAXSEG || !pf_pull_hdr(pd->m, 3372 pd->off + sizeof(struct tcphdr), opts, olen, NULL, NULL, pd->af)) 3373 return (0); 3374 3375 opt = opts; 3376 while ((opt = pf_find_tcpopt(opt, opts, olen, 3377 TCPOPT_MAXSEG, TCPOLEN_MAXSEG)) != NULL) { 3378 memcpy(&mss, (opt + 2), 2); 3379 mss = ntohs(mss); 3380 3381 opt += opt[1]; 3382 } 3383 return (mss); 3384 } 3385 3386 u_int16_t 3387 pf_calc_mss(struct pf_addr *addr, sa_family_t af, int rtableid, u_int16_t offer) 3388 { 3389 struct ifnet *ifp; 3390 struct sockaddr_in *dst; 3391 #ifdef INET6 3392 struct sockaddr_in6 *dst6; 3393 #endif /* INET6 */ 3394 struct rtentry *rt = NULL; 3395 struct sockaddr_storage ss; 3396 int hlen; 3397 u_int16_t mss = tcp_mssdflt; 3398 3399 memset(&ss, 0, sizeof(ss)); 3400 3401 switch (af) { 3402 case AF_INET: 3403 hlen = sizeof(struct ip); 3404 dst = (struct sockaddr_in *)&ss; 3405 dst->sin_family = AF_INET; 3406 dst->sin_len = sizeof(*dst); 3407 dst->sin_addr = addr->v4; 3408 rt = rtalloc(sintosa(dst), 0, rtableid); 3409 break; 3410 #ifdef INET6 3411 case AF_INET6: 3412 hlen = sizeof(struct ip6_hdr); 3413 dst6 = (struct sockaddr_in6 *)&ss; 3414 dst6->sin6_family = AF_INET6; 3415 dst6->sin6_len = sizeof(*dst6); 3416 dst6->sin6_addr = addr->v6; 3417 rt = rtalloc(sin6tosa(dst6), 0, rtableid); 3418 break; 3419 #endif /* INET6 */ 3420 } 3421 3422 if (rt != NULL && (ifp = if_get(rt->rt_ifidx)) != NULL) { 3423 mss = ifp->if_mtu - hlen - sizeof(struct tcphdr); 3424 mss = max(tcp_mssdflt, mss); 3425 if_put(ifp); 3426 } 3427 rtfree(rt); 3428 mss = min(mss, offer); 3429 mss = max(mss, 64); /* sanity - at least max opt space */ 3430 return (mss); 3431 } 3432 3433 static __inline int 3434 pf_set_rt_ifp(struct pf_state *s, struct pf_addr *saddr, sa_family_t af, 3435 struct pf_src_node **sns) 3436 { 3437 struct pf_rule *r = s->rule.ptr; 3438 int rv; 3439 3440 if (!r->rt) 3441 return (0); 3442 3443 rv = pf_map_addr(af, r, saddr, &s->rt_addr, NULL, sns, 3444 &r->route, PF_SN_ROUTE); 3445 if (rv == 0) 3446 s->rt = r->rt; 3447 3448 return (rv); 3449 } 3450 3451 u_int32_t 3452 pf_tcp_iss(struct pf_pdesc *pd) 3453 { 3454 SHA2_CTX ctx; 3455 union { 3456 uint8_t bytes[SHA512_DIGEST_LENGTH]; 3457 uint32_t words[1]; 3458 } digest; 3459 3460 if (pf_tcp_secret_init == 0) { 3461 arc4random_buf(pf_tcp_secret, sizeof(pf_tcp_secret)); 3462 SHA512Init(&pf_tcp_secret_ctx); 3463 SHA512Update(&pf_tcp_secret_ctx, pf_tcp_secret, 3464 sizeof(pf_tcp_secret)); 3465 pf_tcp_secret_init = 1; 3466 } 3467 ctx = pf_tcp_secret_ctx; 3468 3469 SHA512Update(&ctx, &pd->rdomain, sizeof(pd->rdomain)); 3470 SHA512Update(&ctx, &pd->hdr.tcp.th_sport, sizeof(u_short)); 3471 SHA512Update(&ctx, &pd->hdr.tcp.th_dport, sizeof(u_short)); 3472 switch (pd->af) { 3473 case AF_INET: 3474 SHA512Update(&ctx, &pd->src->v4, sizeof(struct in_addr)); 3475 SHA512Update(&ctx, &pd->dst->v4, sizeof(struct in_addr)); 3476 break; 3477 #ifdef INET6 3478 case AF_INET6: 3479 SHA512Update(&ctx, &pd->src->v6, sizeof(struct in6_addr)); 3480 SHA512Update(&ctx, &pd->dst->v6, sizeof(struct in6_addr)); 3481 break; 3482 #endif /* INET6 */ 3483 } 3484 SHA512Final(digest.bytes, &ctx); 3485 pf_tcp_iss_off += 4096; 3486 return (digest.words[0] + tcp_iss + pf_tcp_iss_off); 3487 } 3488 3489 void 3490 pf_rule_to_actions(struct pf_rule *r, struct pf_rule_actions *a) 3491 { 3492 if (r->qid) 3493 a->qid = r->qid; 3494 if (r->pqid) 3495 a->pqid = r->pqid; 3496 if (r->rtableid >= 0) 3497 a->rtableid = r->rtableid; 3498 #if NPFLOG > 0 3499 a->log |= r->log; 3500 #endif /* NPFLOG > 0 */ 3501 if (r->scrub_flags & PFSTATE_SETTOS) 3502 a->set_tos = r->set_tos; 3503 if (r->min_ttl) 3504 a->min_ttl = r->min_ttl; 3505 if (r->max_mss) 3506 a->max_mss = r->max_mss; 3507 a->flags |= (r->scrub_flags & (PFSTATE_NODF|PFSTATE_RANDOMID| 3508 PFSTATE_SETTOS|PFSTATE_SCRUB_TCP|PFSTATE_SETPRIO)); 3509 if (r->scrub_flags & PFSTATE_SETPRIO) { 3510 a->set_prio[0] = r->set_prio[0]; 3511 a->set_prio[1] = r->set_prio[1]; 3512 } 3513 if (r->rule_flag & PFRULE_SETDELAY) 3514 a->delay = r->delay; 3515 } 3516 3517 #define PF_TEST_ATTRIB(t, a) \ 3518 if (t) { \ 3519 r = a; \ 3520 continue; \ 3521 } else do { \ 3522 } while (0) 3523 3524 enum pf_test_status 3525 pf_match_rule(struct pf_test_ctx *ctx, struct pf_ruleset *ruleset) 3526 { 3527 struct pf_rule *r; 3528 struct pf_rule *save_a; 3529 struct pf_ruleset *save_aruleset; 3530 3531 r = TAILQ_FIRST(ruleset->rules.active.ptr); 3532 while (r != NULL) { 3533 r->evaluations++; 3534 PF_TEST_ATTRIB( 3535 (pfi_kif_match(r->kif, ctx->pd->kif) == r->ifnot), 3536 r->skip[PF_SKIP_IFP].ptr); 3537 PF_TEST_ATTRIB((r->direction && r->direction != ctx->pd->dir), 3538 r->skip[PF_SKIP_DIR].ptr); 3539 PF_TEST_ATTRIB((r->onrdomain >= 0 && 3540 (r->onrdomain == ctx->pd->rdomain) == r->ifnot), 3541 r->skip[PF_SKIP_RDOM].ptr); 3542 PF_TEST_ATTRIB((r->af && r->af != ctx->pd->af), 3543 r->skip[PF_SKIP_AF].ptr); 3544 PF_TEST_ATTRIB((r->proto && r->proto != ctx->pd->proto), 3545 r->skip[PF_SKIP_PROTO].ptr); 3546 PF_TEST_ATTRIB((PF_MISMATCHAW(&r->src.addr, &ctx->pd->nsaddr, 3547 ctx->pd->naf, r->src.neg, ctx->pd->kif, 3548 ctx->act.rtableid)), 3549 r->skip[PF_SKIP_SRC_ADDR].ptr); 3550 PF_TEST_ATTRIB((PF_MISMATCHAW(&r->dst.addr, &ctx->pd->ndaddr, 3551 ctx->pd->af, r->dst.neg, NULL, ctx->act.rtableid)), 3552 r->skip[PF_SKIP_DST_ADDR].ptr); 3553 3554 switch (ctx->pd->virtual_proto) { 3555 case PF_VPROTO_FRAGMENT: 3556 /* tcp/udp only. port_op always 0 in other cases */ 3557 PF_TEST_ATTRIB((r->src.port_op || r->dst.port_op), 3558 TAILQ_NEXT(r, entries)); 3559 PF_TEST_ATTRIB((ctx->pd->proto == IPPROTO_TCP && 3560 r->flagset), 3561 TAILQ_NEXT(r, entries)); 3562 /* icmp only. type/code always 0 in other cases */ 3563 PF_TEST_ATTRIB((r->type || r->code), 3564 TAILQ_NEXT(r, entries)); 3565 /* tcp/udp only. {uid|gid}.op always 0 in other cases */ 3566 PF_TEST_ATTRIB((r->gid.op || r->uid.op), 3567 TAILQ_NEXT(r, entries)); 3568 break; 3569 3570 case IPPROTO_TCP: 3571 PF_TEST_ATTRIB(((r->flagset & ctx->th->th_flags) != 3572 r->flags), 3573 TAILQ_NEXT(r, entries)); 3574 PF_TEST_ATTRIB((r->os_fingerprint != PF_OSFP_ANY && 3575 !pf_osfp_match(pf_osfp_fingerprint(ctx->pd), 3576 r->os_fingerprint)), 3577 TAILQ_NEXT(r, entries)); 3578 /* FALLTHROUGH */ 3579 3580 case IPPROTO_UDP: 3581 /* tcp/udp only. port_op always 0 in other cases */ 3582 PF_TEST_ATTRIB((r->src.port_op && 3583 !pf_match_port(r->src.port_op, r->src.port[0], 3584 r->src.port[1], ctx->pd->nsport)), 3585 r->skip[PF_SKIP_SRC_PORT].ptr); 3586 PF_TEST_ATTRIB((r->dst.port_op && 3587 !pf_match_port(r->dst.port_op, r->dst.port[0], 3588 r->dst.port[1], ctx->pd->ndport)), 3589 r->skip[PF_SKIP_DST_PORT].ptr); 3590 /* tcp/udp only. uid.op always 0 in other cases */ 3591 PF_TEST_ATTRIB((r->uid.op && (ctx->pd->lookup.done || 3592 (ctx->pd->lookup.done = 3593 pf_socket_lookup(ctx->pd), 1)) && 3594 !pf_match_uid(r->uid.op, r->uid.uid[0], 3595 r->uid.uid[1], ctx->pd->lookup.uid)), 3596 TAILQ_NEXT(r, entries)); 3597 /* tcp/udp only. gid.op always 0 in other cases */ 3598 PF_TEST_ATTRIB((r->gid.op && (ctx->pd->lookup.done || 3599 (ctx->pd->lookup.done = 3600 pf_socket_lookup(ctx->pd), 1)) && 3601 !pf_match_gid(r->gid.op, r->gid.gid[0], 3602 r->gid.gid[1], ctx->pd->lookup.gid)), 3603 TAILQ_NEXT(r, entries)); 3604 break; 3605 3606 case IPPROTO_ICMP: 3607 case IPPROTO_ICMPV6: 3608 /* icmp only. type always 0 in other cases */ 3609 PF_TEST_ATTRIB((r->type && 3610 r->type != ctx->icmptype + 1), 3611 TAILQ_NEXT(r, entries)); 3612 /* icmp only. type always 0 in other cases */ 3613 PF_TEST_ATTRIB((r->code && 3614 r->code != ctx->icmpcode + 1), 3615 TAILQ_NEXT(r, entries)); 3616 /* icmp only. don't create states on replies */ 3617 PF_TEST_ATTRIB((r->keep_state && !ctx->state_icmp && 3618 (r->rule_flag & PFRULE_STATESLOPPY) == 0 && 3619 ctx->icmp_dir != PF_IN), 3620 TAILQ_NEXT(r, entries)); 3621 break; 3622 3623 default: 3624 break; 3625 } 3626 3627 PF_TEST_ATTRIB((r->rule_flag & PFRULE_FRAGMENT && 3628 ctx->pd->virtual_proto != PF_VPROTO_FRAGMENT), 3629 TAILQ_NEXT(r, entries)); 3630 PF_TEST_ATTRIB((r->tos && !(r->tos == ctx->pd->tos)), 3631 TAILQ_NEXT(r, entries)); 3632 PF_TEST_ATTRIB((r->prob && 3633 r->prob <= arc4random_uniform(UINT_MAX - 1) + 1), 3634 TAILQ_NEXT(r, entries)); 3635 PF_TEST_ATTRIB((r->match_tag && 3636 !pf_match_tag(ctx->pd->m, r, &ctx->tag)), 3637 TAILQ_NEXT(r, entries)); 3638 PF_TEST_ATTRIB((r->rcv_kif && pf_match_rcvif(ctx->pd->m, r) == 3639 r->rcvifnot), 3640 TAILQ_NEXT(r, entries)); 3641 PF_TEST_ATTRIB((r->prio && 3642 (r->prio == PF_PRIO_ZERO ? 0 : r->prio) != 3643 ctx->pd->m->m_pkthdr.pf.prio), 3644 TAILQ_NEXT(r, entries)); 3645 3646 /* must be last! */ 3647 if (r->pktrate.limit) { 3648 pf_add_threshold(&r->pktrate); 3649 PF_TEST_ATTRIB((pf_check_threshold(&r->pktrate)), 3650 TAILQ_NEXT(r, entries)); 3651 } 3652 3653 /* FALLTHROUGH */ 3654 if (r->tag) 3655 ctx->tag = r->tag; 3656 if (r->anchor == NULL) { 3657 if (r->action == PF_MATCH) { 3658 if ((ctx->ri = pool_get(&pf_rule_item_pl, 3659 PR_NOWAIT)) == NULL) { 3660 REASON_SET(&ctx->reason, PFRES_MEMORY); 3661 ctx->test_status = PF_TEST_FAIL; 3662 break; 3663 } 3664 ctx->ri->r = r; 3665 /* order is irrelevant */ 3666 SLIST_INSERT_HEAD(&ctx->rules, ctx->ri, entry); 3667 ctx->ri = NULL; 3668 pf_rule_to_actions(r, &ctx->act); 3669 if (r->rule_flag & PFRULE_AFTO) 3670 ctx->pd->naf = r->naf; 3671 if (pf_get_transaddr(r, ctx->pd, ctx->sns, 3672 &ctx->nr) == -1) { 3673 REASON_SET(&ctx->reason, 3674 PFRES_TRANSLATE); 3675 ctx->test_status = PF_TEST_FAIL; 3676 break; 3677 } 3678 #if NPFLOG > 0 3679 if (r->log) { 3680 REASON_SET(&ctx->reason, PFRES_MATCH); 3681 pflog_packet(ctx->pd, ctx->reason, r, 3682 ctx->a, ruleset, NULL); 3683 } 3684 #endif /* NPFLOG > 0 */ 3685 } else { 3686 /* 3687 * found matching r 3688 */ 3689 *ctx->rm = r; 3690 /* 3691 * anchor, with ruleset, where r belongs to 3692 */ 3693 *ctx->am = ctx->a; 3694 /* 3695 * ruleset where r belongs to 3696 */ 3697 *ctx->rsm = ruleset; 3698 /* 3699 * ruleset, where anchor belongs to. 3700 */ 3701 ctx->arsm = ctx->aruleset; 3702 } 3703 3704 #if NPFLOG > 0 3705 if (ctx->act.log & PF_LOG_MATCHES) 3706 pf_log_matches(ctx->pd, r, ctx->a, ruleset, 3707 &ctx->rules); 3708 #endif /* NPFLOG > 0 */ 3709 3710 if (r->quick) { 3711 ctx->test_status = PF_TEST_QUICK; 3712 break; 3713 } 3714 } else { 3715 save_a = ctx->a; 3716 save_aruleset = ctx->aruleset; 3717 ctx->a = r; /* remember anchor */ 3718 ctx->aruleset = ruleset; /* and its ruleset */ 3719 /* 3720 * Note: we don't need to restore if we are not going 3721 * to continue with ruleset evaluation. 3722 */ 3723 if (pf_step_into_anchor(ctx, r) != PF_TEST_OK) 3724 break; 3725 ctx->a = save_a; 3726 ctx->aruleset = save_aruleset; 3727 } 3728 r = TAILQ_NEXT(r, entries); 3729 } 3730 3731 return (ctx->test_status); 3732 } 3733 3734 int 3735 pf_test_rule(struct pf_pdesc *pd, struct pf_rule **rm, struct pf_state **sm, 3736 struct pf_rule **am, struct pf_ruleset **rsm, u_short *reason) 3737 { 3738 struct pf_rule *r = NULL; 3739 struct pf_rule *a = NULL; 3740 struct pf_ruleset *ruleset = NULL; 3741 struct pf_state_key *skw = NULL, *sks = NULL; 3742 int rewrite = 0; 3743 u_int16_t virtual_type, virtual_id; 3744 int action = PF_DROP; 3745 struct pf_test_ctx ctx; 3746 int rv; 3747 3748 memset(&ctx, 0, sizeof(ctx)); 3749 ctx.pd = pd; 3750 ctx.rm = rm; 3751 ctx.am = am; 3752 ctx.rsm = rsm; 3753 ctx.th = &pd->hdr.tcp; 3754 ctx.act.rtableid = pd->rdomain; 3755 ctx.tag = -1; 3756 SLIST_INIT(&ctx.rules); 3757 3758 if (pd->dir == PF_IN && if_congested()) { 3759 REASON_SET(&ctx.reason, PFRES_CONGEST); 3760 return (PF_DROP); 3761 } 3762 3763 switch (pd->virtual_proto) { 3764 case IPPROTO_ICMP: 3765 ctx.icmptype = pd->hdr.icmp.icmp_type; 3766 ctx.icmpcode = pd->hdr.icmp.icmp_code; 3767 ctx.state_icmp = pf_icmp_mapping(pd, ctx.icmptype, 3768 &ctx.icmp_dir, &virtual_id, &virtual_type); 3769 if (ctx.icmp_dir == PF_IN) { 3770 pd->osport = pd->nsport = virtual_id; 3771 pd->odport = pd->ndport = virtual_type; 3772 } else { 3773 pd->osport = pd->nsport = virtual_type; 3774 pd->odport = pd->ndport = virtual_id; 3775 } 3776 break; 3777 #ifdef INET6 3778 case IPPROTO_ICMPV6: 3779 ctx.icmptype = pd->hdr.icmp6.icmp6_type; 3780 ctx.icmpcode = pd->hdr.icmp6.icmp6_code; 3781 ctx.state_icmp = pf_icmp_mapping(pd, ctx.icmptype, 3782 &ctx.icmp_dir, &virtual_id, &virtual_type); 3783 if (ctx.icmp_dir == PF_IN) { 3784 pd->osport = pd->nsport = virtual_id; 3785 pd->odport = pd->ndport = virtual_type; 3786 } else { 3787 pd->osport = pd->nsport = virtual_type; 3788 pd->odport = pd->ndport = virtual_id; 3789 } 3790 break; 3791 #endif /* INET6 */ 3792 } 3793 3794 ruleset = &pf_main_ruleset; 3795 rv = pf_match_rule(&ctx, ruleset); 3796 if (rv == PF_TEST_FAIL) { 3797 /* 3798 * Reason has been set in pf_match_rule() already. 3799 */ 3800 goto cleanup; 3801 } 3802 3803 r = *ctx.rm; /* matching rule */ 3804 a = *ctx.am; /* rule that defines an anchor containing 'r' */ 3805 ruleset = *ctx.rsm;/* ruleset of the anchor defined by the rule 'a' */ 3806 ctx.aruleset = ctx.arsm;/* ruleset of the 'a' rule itself */ 3807 3808 /* apply actions for last matching pass/block rule */ 3809 pf_rule_to_actions(r, &ctx.act); 3810 if (r->rule_flag & PFRULE_AFTO) 3811 pd->naf = r->naf; 3812 if (pf_get_transaddr(r, pd, ctx.sns, &ctx.nr) == -1) { 3813 REASON_SET(&ctx.reason, PFRES_TRANSLATE); 3814 goto cleanup; 3815 } 3816 REASON_SET(&ctx.reason, PFRES_MATCH); 3817 3818 #if NPFLOG > 0 3819 if (r->log) 3820 pflog_packet(pd, ctx.reason, r, a, ruleset, NULL); 3821 if (ctx.act.log & PF_LOG_MATCHES) 3822 pf_log_matches(pd, r, a, ruleset, &ctx.rules); 3823 #endif /* NPFLOG > 0 */ 3824 3825 if (pd->virtual_proto != PF_VPROTO_FRAGMENT && 3826 (r->action == PF_DROP) && 3827 ((r->rule_flag & PFRULE_RETURNRST) || 3828 (r->rule_flag & PFRULE_RETURNICMP) || 3829 (r->rule_flag & PFRULE_RETURN))) { 3830 if (pd->proto == IPPROTO_TCP && 3831 ((r->rule_flag & PFRULE_RETURNRST) || 3832 (r->rule_flag & PFRULE_RETURN)) && 3833 !(ctx.th->th_flags & TH_RST)) { 3834 u_int32_t ack = 3835 ntohl(ctx.th->th_seq) + pd->p_len; 3836 3837 if (pf_check_tcp_cksum(pd->m, pd->off, 3838 pd->tot_len - pd->off, pd->af)) 3839 REASON_SET(&ctx.reason, PFRES_PROTCKSUM); 3840 else { 3841 if (ctx.th->th_flags & TH_SYN) 3842 ack++; 3843 if (ctx.th->th_flags & TH_FIN) 3844 ack++; 3845 pf_send_tcp(r, pd->af, pd->dst, 3846 pd->src, ctx.th->th_dport, 3847 ctx.th->th_sport, ntohl(ctx.th->th_ack), 3848 ack, TH_RST|TH_ACK, 0, 0, r->return_ttl, 3849 1, 0, pd->rdomain); 3850 } 3851 } else if ((pd->proto != IPPROTO_ICMP || 3852 ICMP_INFOTYPE(ctx.icmptype)) && pd->af == AF_INET && 3853 r->return_icmp) 3854 pf_send_icmp(pd->m, r->return_icmp >> 8, 3855 r->return_icmp & 255, 0, pd->af, r, pd->rdomain); 3856 else if ((pd->proto != IPPROTO_ICMPV6 || 3857 (ctx.icmptype >= ICMP6_ECHO_REQUEST && 3858 ctx.icmptype != ND_REDIRECT)) && pd->af == AF_INET6 && 3859 r->return_icmp6) 3860 pf_send_icmp(pd->m, r->return_icmp6 >> 8, 3861 r->return_icmp6 & 255, 0, pd->af, r, pd->rdomain); 3862 } 3863 3864 if (r->action == PF_DROP) 3865 goto cleanup; 3866 3867 /* 3868 * If an expired "once" rule has not been purged, drop any new matching 3869 * packets. 3870 */ 3871 if (r->rule_flag & PFRULE_EXPIRED) 3872 goto cleanup; 3873 3874 pf_tag_packet(pd->m, ctx.tag, ctx.act.rtableid); 3875 if (ctx.act.rtableid >= 0 && 3876 rtable_l2(ctx.act.rtableid) != pd->rdomain) 3877 pd->destchg = 1; 3878 3879 if (r->action == PF_PASS && pd->badopts && ! r->allow_opts) { 3880 REASON_SET(&ctx.reason, PFRES_IPOPTIONS); 3881 #if NPFLOG > 0 3882 pd->pflog |= PF_LOG_FORCE; 3883 #endif /* NPFLOG > 0 */ 3884 DPFPRINTF(LOG_NOTICE, "dropping packet with " 3885 "ip/ipv6 options in pf_test_rule()"); 3886 goto cleanup; 3887 } 3888 3889 action = PF_PASS; 3890 3891 if (pd->virtual_proto != PF_VPROTO_FRAGMENT 3892 && !ctx.state_icmp && r->keep_state) { 3893 3894 if (r->rule_flag & PFRULE_SRCTRACK && 3895 pf_insert_src_node(&ctx.sns[PF_SN_NONE], r, PF_SN_NONE, 3896 pd->af, pd->src, NULL, NULL) != 0) { 3897 REASON_SET(&ctx.reason, PFRES_SRCLIMIT); 3898 goto cleanup; 3899 } 3900 3901 if (r->max_states && (r->states_cur >= r->max_states)) { 3902 pf_status.lcounters[LCNT_STATES]++; 3903 REASON_SET(&ctx.reason, PFRES_MAXSTATES); 3904 goto cleanup; 3905 } 3906 3907 action = pf_create_state(pd, r, a, ctx.nr, &skw, &sks, 3908 &rewrite, sm, ctx.tag, &ctx.rules, &ctx.act, ctx.sns); 3909 3910 if (action != PF_PASS) 3911 goto cleanup; 3912 if (sks != skw) { 3913 struct pf_state_key *sk; 3914 3915 if (pd->dir == PF_IN) 3916 sk = sks; 3917 else 3918 sk = skw; 3919 rewrite += pf_translate(pd, 3920 &sk->addr[pd->af == pd->naf ? pd->sidx : pd->didx], 3921 sk->port[pd->af == pd->naf ? pd->sidx : pd->didx], 3922 &sk->addr[pd->af == pd->naf ? pd->didx : pd->sidx], 3923 sk->port[pd->af == pd->naf ? pd->didx : pd->sidx], 3924 virtual_type, ctx.icmp_dir); 3925 } 3926 3927 #ifdef INET6 3928 if (rewrite && skw->af != sks->af) 3929 action = PF_AFRT; 3930 #endif /* INET6 */ 3931 3932 } else { 3933 while ((ctx.ri = SLIST_FIRST(&ctx.rules))) { 3934 SLIST_REMOVE_HEAD(&ctx.rules, entry); 3935 pool_put(&pf_rule_item_pl, ctx.ri); 3936 } 3937 } 3938 3939 /* copy back packet headers if needed */ 3940 if (rewrite && pd->hdrlen) { 3941 m_copyback(pd->m, pd->off, pd->hdrlen, &pd->hdr, M_NOWAIT); 3942 } 3943 3944 if (r->rule_flag & PFRULE_ONCE) { 3945 u_int32_t rule_flag; 3946 3947 /* 3948 * Use atomic_cas() to determine a clear winner, which will 3949 * insert an expired rule to gcl. 3950 */ 3951 rule_flag = r->rule_flag; 3952 if (((rule_flag & PFRULE_EXPIRED) == 0) && 3953 atomic_cas_uint(&r->rule_flag, rule_flag, 3954 rule_flag | PFRULE_EXPIRED) == rule_flag) { 3955 r->exptime = gettime(); 3956 SLIST_INSERT_HEAD(&pf_rule_gcl, r, gcle); 3957 } 3958 } 3959 3960 #if NPFSYNC > 0 3961 if (*sm != NULL && !ISSET((*sm)->state_flags, PFSTATE_NOSYNC) && 3962 pd->dir == PF_OUT && pfsync_up()) { 3963 /* 3964 * We want the state created, but we dont 3965 * want to send this in case a partner 3966 * firewall has to know about it to allow 3967 * replies through it. 3968 */ 3969 if (pfsync_defer(*sm, pd->m)) 3970 return (PF_DEFER); 3971 } 3972 #endif /* NPFSYNC > 0 */ 3973 3974 return (action); 3975 3976 cleanup: 3977 while ((ctx.ri = SLIST_FIRST(&ctx.rules))) { 3978 SLIST_REMOVE_HEAD(&ctx.rules, entry); 3979 pool_put(&pf_rule_item_pl, ctx.ri); 3980 } 3981 3982 return (action); 3983 } 3984 3985 static __inline int 3986 pf_create_state(struct pf_pdesc *pd, struct pf_rule *r, struct pf_rule *a, 3987 struct pf_rule *nr, struct pf_state_key **skw, struct pf_state_key **sks, 3988 int *rewrite, struct pf_state **sm, int tag, struct pf_rule_slist *rules, 3989 struct pf_rule_actions *act, struct pf_src_node *sns[PF_SN_MAX]) 3990 { 3991 struct pf_state *s = NULL; 3992 struct tcphdr *th = &pd->hdr.tcp; 3993 u_int16_t mss = tcp_mssdflt; 3994 u_short reason; 3995 u_int i; 3996 3997 s = pool_get(&pf_state_pl, PR_NOWAIT | PR_ZERO); 3998 if (s == NULL) { 3999 REASON_SET(&reason, PFRES_MEMORY); 4000 goto csfailed; 4001 } 4002 s->rule.ptr = r; 4003 s->anchor.ptr = a; 4004 s->natrule.ptr = nr; 4005 if (r->allow_opts) 4006 s->state_flags |= PFSTATE_ALLOWOPTS; 4007 if (r->rule_flag & PFRULE_STATESLOPPY) 4008 s->state_flags |= PFSTATE_SLOPPY; 4009 if (r->rule_flag & PFRULE_PFLOW) 4010 s->state_flags |= PFSTATE_PFLOW; 4011 #if NPFLOG > 0 4012 s->log = act->log & PF_LOG_ALL; 4013 #endif /* NPFLOG > 0 */ 4014 s->qid = act->qid; 4015 s->pqid = act->pqid; 4016 s->rtableid[pd->didx] = act->rtableid; 4017 s->rtableid[pd->sidx] = -1; /* return traffic is routed normally */ 4018 s->min_ttl = act->min_ttl; 4019 s->set_tos = act->set_tos; 4020 s->max_mss = act->max_mss; 4021 s->state_flags |= act->flags; 4022 #if NPFSYNC > 0 4023 s->sync_state = PFSYNC_S_NONE; 4024 #endif /* NPFSYNC > 0 */ 4025 s->set_prio[0] = act->set_prio[0]; 4026 s->set_prio[1] = act->set_prio[1]; 4027 s->delay = act->delay; 4028 SLIST_INIT(&s->src_nodes); 4029 /* 4030 * must initialize refcnt, before pf_state_insert() gets called. 4031 * pf_state_inserts() grabs reference for pfsync! 4032 */ 4033 refcnt_init(&s->refcnt); 4034 4035 switch (pd->proto) { 4036 case IPPROTO_TCP: 4037 s->src.seqlo = ntohl(th->th_seq); 4038 s->src.seqhi = s->src.seqlo + pd->p_len + 1; 4039 if ((th->th_flags & (TH_SYN|TH_ACK)) == TH_SYN && 4040 r->keep_state == PF_STATE_MODULATE) { 4041 /* Generate sequence number modulator */ 4042 if ((s->src.seqdiff = pf_tcp_iss(pd) - s->src.seqlo) == 4043 0) 4044 s->src.seqdiff = 1; 4045 pf_patch_32(pd, 4046 &th->th_seq, htonl(s->src.seqlo + s->src.seqdiff)); 4047 *rewrite = 1; 4048 } else 4049 s->src.seqdiff = 0; 4050 if (th->th_flags & TH_SYN) { 4051 s->src.seqhi++; 4052 s->src.wscale = pf_get_wscale(pd); 4053 } 4054 s->src.max_win = MAX(ntohs(th->th_win), 1); 4055 if (s->src.wscale & PF_WSCALE_MASK) { 4056 /* Remove scale factor from initial window */ 4057 int win = s->src.max_win; 4058 win += 1 << (s->src.wscale & PF_WSCALE_MASK); 4059 s->src.max_win = (win - 1) >> 4060 (s->src.wscale & PF_WSCALE_MASK); 4061 } 4062 if (th->th_flags & TH_FIN) 4063 s->src.seqhi++; 4064 s->dst.seqhi = 1; 4065 s->dst.max_win = 1; 4066 pf_set_protostate(s, PF_PEER_SRC, TCPS_SYN_SENT); 4067 pf_set_protostate(s, PF_PEER_DST, TCPS_CLOSED); 4068 s->timeout = PFTM_TCP_FIRST_PACKET; 4069 pf_status.states_halfopen++; 4070 break; 4071 case IPPROTO_UDP: 4072 pf_set_protostate(s, PF_PEER_SRC, PFUDPS_SINGLE); 4073 pf_set_protostate(s, PF_PEER_DST, PFUDPS_NO_TRAFFIC); 4074 s->timeout = PFTM_UDP_FIRST_PACKET; 4075 break; 4076 case IPPROTO_ICMP: 4077 #ifdef INET6 4078 case IPPROTO_ICMPV6: 4079 #endif /* INET6 */ 4080 s->timeout = PFTM_ICMP_FIRST_PACKET; 4081 break; 4082 default: 4083 pf_set_protostate(s, PF_PEER_SRC, PFOTHERS_SINGLE); 4084 pf_set_protostate(s, PF_PEER_DST, PFOTHERS_NO_TRAFFIC); 4085 s->timeout = PFTM_OTHER_FIRST_PACKET; 4086 } 4087 4088 s->creation = getuptime(); 4089 s->expire = getuptime(); 4090 4091 if (pd->proto == IPPROTO_TCP) { 4092 if (s->state_flags & PFSTATE_SCRUB_TCP && 4093 pf_normalize_tcp_init(pd, &s->src)) { 4094 REASON_SET(&reason, PFRES_MEMORY); 4095 goto csfailed; 4096 } 4097 if (s->state_flags & PFSTATE_SCRUB_TCP && s->src.scrub && 4098 pf_normalize_tcp_stateful(pd, &reason, s, &s->src, &s->dst, 4099 rewrite)) { 4100 /* This really shouldn't happen!!! */ 4101 DPFPRINTF(LOG_ERR, 4102 "%s: tcp normalize failed on first pkt", __func__); 4103 goto csfailed; 4104 } 4105 } 4106 s->direction = pd->dir; 4107 4108 if (pf_state_key_setup(pd, skw, sks, act->rtableid)) { 4109 REASON_SET(&reason, PFRES_MEMORY); 4110 goto csfailed; 4111 } 4112 4113 if (pf_set_rt_ifp(s, pd->src, (*skw)->af, sns) != 0) { 4114 REASON_SET(&reason, PFRES_NOROUTE); 4115 goto csfailed; 4116 } 4117 4118 for (i = 0; i < PF_SN_MAX; i++) 4119 if (sns[i] != NULL) { 4120 struct pf_sn_item *sni; 4121 4122 sni = pool_get(&pf_sn_item_pl, PR_NOWAIT); 4123 if (sni == NULL) { 4124 REASON_SET(&reason, PFRES_MEMORY); 4125 goto csfailed; 4126 } 4127 sni->sn = sns[i]; 4128 SLIST_INSERT_HEAD(&s->src_nodes, sni, next); 4129 sni->sn->states++; 4130 } 4131 4132 if (pf_state_insert(BOUND_IFACE(r, pd->kif), skw, sks, s)) { 4133 pf_detach_state(s); 4134 *sks = *skw = NULL; 4135 REASON_SET(&reason, PFRES_STATEINS); 4136 goto csfailed; 4137 } else 4138 *sm = s; 4139 4140 /* 4141 * Make state responsible for rules it binds here. 4142 */ 4143 memcpy(&s->match_rules, rules, sizeof(s->match_rules)); 4144 memset(rules, 0, sizeof(*rules)); 4145 STATE_INC_COUNTERS(s); 4146 4147 if (tag > 0) { 4148 pf_tag_ref(tag); 4149 s->tag = tag; 4150 } 4151 if (pd->proto == IPPROTO_TCP && (th->th_flags & (TH_SYN|TH_ACK)) == 4152 TH_SYN && r->keep_state == PF_STATE_SYNPROXY && pd->dir == PF_IN) { 4153 int rtid = pd->rdomain; 4154 if (act->rtableid >= 0) 4155 rtid = act->rtableid; 4156 pf_set_protostate(s, PF_PEER_SRC, PF_TCPS_PROXY_SRC); 4157 s->src.seqhi = arc4random(); 4158 /* Find mss option */ 4159 mss = pf_get_mss(pd); 4160 mss = pf_calc_mss(pd->src, pd->af, rtid, mss); 4161 mss = pf_calc_mss(pd->dst, pd->af, rtid, mss); 4162 s->src.mss = mss; 4163 pf_send_tcp(r, pd->af, pd->dst, pd->src, th->th_dport, 4164 th->th_sport, s->src.seqhi, ntohl(th->th_seq) + 1, 4165 TH_SYN|TH_ACK, 0, s->src.mss, 0, 1, 0, pd->rdomain); 4166 REASON_SET(&reason, PFRES_SYNPROXY); 4167 return (PF_SYNPROXY_DROP); 4168 } 4169 4170 return (PF_PASS); 4171 4172 csfailed: 4173 if (s) { 4174 pf_normalize_tcp_cleanup(s); /* safe even w/o init */ 4175 pf_src_tree_remove_state(s); 4176 pool_put(&pf_state_pl, s); 4177 } 4178 4179 for (i = 0; i < PF_SN_MAX; i++) 4180 if (sns[i] != NULL) 4181 pf_remove_src_node(sns[i]); 4182 4183 return (PF_DROP); 4184 } 4185 4186 int 4187 pf_translate(struct pf_pdesc *pd, struct pf_addr *saddr, u_int16_t sport, 4188 struct pf_addr *daddr, u_int16_t dport, u_int16_t virtual_type, 4189 int icmp_dir) 4190 { 4191 int rewrite = 0; 4192 int afto = pd->af != pd->naf; 4193 4194 if (afto || PF_ANEQ(daddr, pd->dst, pd->af)) 4195 pd->destchg = 1; 4196 4197 switch (pd->proto) { 4198 case IPPROTO_TCP: /* FALLTHROUGH */ 4199 case IPPROTO_UDP: 4200 rewrite += pf_patch_16(pd, pd->sport, sport); 4201 rewrite += pf_patch_16(pd, pd->dport, dport); 4202 break; 4203 4204 case IPPROTO_ICMP: 4205 if (pd->af != AF_INET) 4206 return (0); 4207 4208 #ifdef INET6 4209 if (afto) { 4210 if (pf_translate_icmp_af(pd, AF_INET6, &pd->hdr.icmp)) 4211 return (0); 4212 pd->proto = IPPROTO_ICMPV6; 4213 rewrite = 1; 4214 } 4215 #endif /* INET6 */ 4216 if (virtual_type == htons(ICMP_ECHO)) { 4217 u_int16_t icmpid = (icmp_dir == PF_IN) ? sport : dport; 4218 rewrite += pf_patch_16(pd, 4219 &pd->hdr.icmp.icmp_id, icmpid); 4220 } 4221 break; 4222 4223 #ifdef INET6 4224 case IPPROTO_ICMPV6: 4225 if (pd->af != AF_INET6) 4226 return (0); 4227 4228 if (afto) { 4229 if (pf_translate_icmp_af(pd, AF_INET, &pd->hdr.icmp6)) 4230 return (0); 4231 pd->proto = IPPROTO_ICMP; 4232 rewrite = 1; 4233 } 4234 if (virtual_type == htons(ICMP6_ECHO_REQUEST)) { 4235 u_int16_t icmpid = (icmp_dir == PF_IN) ? sport : dport; 4236 rewrite += pf_patch_16(pd, 4237 &pd->hdr.icmp6.icmp6_id, icmpid); 4238 } 4239 break; 4240 #endif /* INET6 */ 4241 } 4242 4243 if (!afto) { 4244 rewrite += pf_translate_a(pd, pd->src, saddr); 4245 rewrite += pf_translate_a(pd, pd->dst, daddr); 4246 } 4247 4248 return (rewrite); 4249 } 4250 4251 int 4252 pf_tcp_track_full(struct pf_pdesc *pd, struct pf_state **state, u_short *reason, 4253 int *copyback, int reverse) 4254 { 4255 struct tcphdr *th = &pd->hdr.tcp; 4256 struct pf_state_peer *src, *dst; 4257 u_int16_t win = ntohs(th->th_win); 4258 u_int32_t ack, end, data_end, seq, orig_seq; 4259 u_int8_t sws, dws, psrc, pdst; 4260 int ackskew; 4261 4262 if ((pd->dir == (*state)->direction && !reverse) || 4263 (pd->dir != (*state)->direction && reverse)) { 4264 src = &(*state)->src; 4265 dst = &(*state)->dst; 4266 psrc = PF_PEER_SRC; 4267 pdst = PF_PEER_DST; 4268 } else { 4269 src = &(*state)->dst; 4270 dst = &(*state)->src; 4271 psrc = PF_PEER_DST; 4272 pdst = PF_PEER_SRC; 4273 } 4274 4275 if (src->wscale && dst->wscale && !(th->th_flags & TH_SYN)) { 4276 sws = src->wscale & PF_WSCALE_MASK; 4277 dws = dst->wscale & PF_WSCALE_MASK; 4278 } else 4279 sws = dws = 0; 4280 4281 /* 4282 * Sequence tracking algorithm from Guido van Rooij's paper: 4283 * http://www.madison-gurkha.com/publications/tcp_filtering/ 4284 * tcp_filtering.ps 4285 */ 4286 4287 orig_seq = seq = ntohl(th->th_seq); 4288 if (src->seqlo == 0) { 4289 /* First packet from this end. Set its state */ 4290 4291 if (((*state)->state_flags & PFSTATE_SCRUB_TCP || dst->scrub) && 4292 src->scrub == NULL) { 4293 if (pf_normalize_tcp_init(pd, src)) { 4294 REASON_SET(reason, PFRES_MEMORY); 4295 return (PF_DROP); 4296 } 4297 } 4298 4299 /* Deferred generation of sequence number modulator */ 4300 if (dst->seqdiff && !src->seqdiff) { 4301 /* use random iss for the TCP server */ 4302 while ((src->seqdiff = arc4random() - seq) == 0) 4303 continue; 4304 ack = ntohl(th->th_ack) - dst->seqdiff; 4305 pf_patch_32(pd, &th->th_seq, htonl(seq + src->seqdiff)); 4306 pf_patch_32(pd, &th->th_ack, htonl(ack)); 4307 *copyback = 1; 4308 } else { 4309 ack = ntohl(th->th_ack); 4310 } 4311 4312 end = seq + pd->p_len; 4313 if (th->th_flags & TH_SYN) { 4314 end++; 4315 if (dst->wscale & PF_WSCALE_FLAG) { 4316 src->wscale = pf_get_wscale(pd); 4317 if (src->wscale & PF_WSCALE_FLAG) { 4318 /* Remove scale factor from initial 4319 * window */ 4320 sws = src->wscale & PF_WSCALE_MASK; 4321 win = ((u_int32_t)win + (1 << sws) - 1) 4322 >> sws; 4323 dws = dst->wscale & PF_WSCALE_MASK; 4324 } else { 4325 /* fixup other window */ 4326 dst->max_win = MIN(TCP_MAXWIN, 4327 (u_int32_t)dst->max_win << 4328 (dst->wscale & PF_WSCALE_MASK)); 4329 /* in case of a retrans SYN|ACK */ 4330 dst->wscale = 0; 4331 } 4332 } 4333 } 4334 data_end = end; 4335 if (th->th_flags & TH_FIN) 4336 end++; 4337 4338 src->seqlo = seq; 4339 if (src->state < TCPS_SYN_SENT) 4340 pf_set_protostate(*state, psrc, TCPS_SYN_SENT); 4341 4342 /* 4343 * May need to slide the window (seqhi may have been set by 4344 * the crappy stack check or if we picked up the connection 4345 * after establishment) 4346 */ 4347 if (src->seqhi == 1 || 4348 SEQ_GEQ(end + MAX(1, dst->max_win << dws), src->seqhi)) 4349 src->seqhi = end + MAX(1, dst->max_win << dws); 4350 if (win > src->max_win) 4351 src->max_win = win; 4352 4353 } else { 4354 ack = ntohl(th->th_ack) - dst->seqdiff; 4355 if (src->seqdiff) { 4356 /* Modulate sequence numbers */ 4357 pf_patch_32(pd, &th->th_seq, htonl(seq + src->seqdiff)); 4358 pf_patch_32(pd, &th->th_ack, htonl(ack)); 4359 *copyback = 1; 4360 } 4361 end = seq + pd->p_len; 4362 if (th->th_flags & TH_SYN) 4363 end++; 4364 data_end = end; 4365 if (th->th_flags & TH_FIN) 4366 end++; 4367 } 4368 4369 if ((th->th_flags & TH_ACK) == 0) { 4370 /* Let it pass through the ack skew check */ 4371 ack = dst->seqlo; 4372 } else if ((ack == 0 && 4373 (th->th_flags & (TH_ACK|TH_RST)) == (TH_ACK|TH_RST)) || 4374 /* broken tcp stacks do not set ack */ 4375 (dst->state < TCPS_SYN_SENT)) { 4376 /* 4377 * Many stacks (ours included) will set the ACK number in an 4378 * FIN|ACK if the SYN times out -- no sequence to ACK. 4379 */ 4380 ack = dst->seqlo; 4381 } 4382 4383 if (seq == end) { 4384 /* Ease sequencing restrictions on no data packets */ 4385 seq = src->seqlo; 4386 data_end = end = seq; 4387 } 4388 4389 ackskew = dst->seqlo - ack; 4390 4391 4392 /* 4393 * Need to demodulate the sequence numbers in any TCP SACK options 4394 * (Selective ACK). We could optionally validate the SACK values 4395 * against the current ACK window, either forwards or backwards, but 4396 * I'm not confident that SACK has been implemented properly 4397 * everywhere. It wouldn't surprise me if several stacks accidently 4398 * SACK too far backwards of previously ACKed data. There really aren't 4399 * any security implications of bad SACKing unless the target stack 4400 * doesn't validate the option length correctly. Someone trying to 4401 * spoof into a TCP connection won't bother blindly sending SACK 4402 * options anyway. 4403 */ 4404 if (dst->seqdiff && (th->th_off << 2) > sizeof(struct tcphdr)) { 4405 if (pf_modulate_sack(pd, dst)) 4406 *copyback = 1; 4407 } 4408 4409 4410 #define MAXACKWINDOW (0xffff + 1500) /* 1500 is an arbitrary fudge factor */ 4411 if (SEQ_GEQ(src->seqhi, data_end) && 4412 /* Last octet inside other's window space */ 4413 SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)) && 4414 /* Retrans: not more than one window back */ 4415 (ackskew >= -MAXACKWINDOW) && 4416 /* Acking not more than one reassembled fragment backwards */ 4417 (ackskew <= (MAXACKWINDOW << sws)) && 4418 /* Acking not more than one window forward */ 4419 ((th->th_flags & TH_RST) == 0 || orig_seq == src->seqlo || 4420 (orig_seq == src->seqlo + 1) || (orig_seq + 1 == src->seqlo))) { 4421 /* Require an exact/+1 sequence match on resets when possible */ 4422 4423 if (dst->scrub || src->scrub) { 4424 if (pf_normalize_tcp_stateful(pd, reason, *state, src, 4425 dst, copyback)) 4426 return (PF_DROP); 4427 } 4428 4429 /* update max window */ 4430 if (src->max_win < win) 4431 src->max_win = win; 4432 /* synchronize sequencing */ 4433 if (SEQ_GT(end, src->seqlo)) 4434 src->seqlo = end; 4435 /* slide the window of what the other end can send */ 4436 if (SEQ_GEQ(ack + (win << sws), dst->seqhi)) 4437 dst->seqhi = ack + MAX((win << sws), 1); 4438 4439 /* update states */ 4440 if (th->th_flags & TH_SYN) 4441 if (src->state < TCPS_SYN_SENT) 4442 pf_set_protostate(*state, psrc, TCPS_SYN_SENT); 4443 if (th->th_flags & TH_FIN) 4444 if (src->state < TCPS_CLOSING) 4445 pf_set_protostate(*state, psrc, TCPS_CLOSING); 4446 if (th->th_flags & TH_ACK) { 4447 if (dst->state == TCPS_SYN_SENT) { 4448 pf_set_protostate(*state, pdst, 4449 TCPS_ESTABLISHED); 4450 if (src->state == TCPS_ESTABLISHED && 4451 !SLIST_EMPTY(&(*state)->src_nodes) && 4452 pf_src_connlimit(state)) { 4453 REASON_SET(reason, PFRES_SRCLIMIT); 4454 return (PF_DROP); 4455 } 4456 } else if (dst->state == TCPS_CLOSING) 4457 pf_set_protostate(*state, pdst, 4458 TCPS_FIN_WAIT_2); 4459 } 4460 if (th->th_flags & TH_RST) 4461 pf_set_protostate(*state, PF_PEER_BOTH, TCPS_TIME_WAIT); 4462 4463 /* update expire time */ 4464 (*state)->expire = getuptime(); 4465 if (src->state >= TCPS_FIN_WAIT_2 && 4466 dst->state >= TCPS_FIN_WAIT_2) 4467 (*state)->timeout = PFTM_TCP_CLOSED; 4468 else if (src->state >= TCPS_CLOSING && 4469 dst->state >= TCPS_CLOSING) 4470 (*state)->timeout = PFTM_TCP_FIN_WAIT; 4471 else if (src->state < TCPS_ESTABLISHED || 4472 dst->state < TCPS_ESTABLISHED) 4473 (*state)->timeout = PFTM_TCP_OPENING; 4474 else if (src->state >= TCPS_CLOSING || 4475 dst->state >= TCPS_CLOSING) 4476 (*state)->timeout = PFTM_TCP_CLOSING; 4477 else 4478 (*state)->timeout = PFTM_TCP_ESTABLISHED; 4479 4480 /* Fall through to PASS packet */ 4481 } else if ((dst->state < TCPS_SYN_SENT || 4482 dst->state >= TCPS_FIN_WAIT_2 || 4483 src->state >= TCPS_FIN_WAIT_2) && 4484 SEQ_GEQ(src->seqhi + MAXACKWINDOW, data_end) && 4485 /* Within a window forward of the originating packet */ 4486 SEQ_GEQ(seq, src->seqlo - MAXACKWINDOW)) { 4487 /* Within a window backward of the originating packet */ 4488 4489 /* 4490 * This currently handles three situations: 4491 * 1) Stupid stacks will shotgun SYNs before their peer 4492 * replies. 4493 * 2) When PF catches an already established stream (the 4494 * firewall rebooted, the state table was flushed, routes 4495 * changed...) 4496 * 3) Packets get funky immediately after the connection 4497 * closes (this should catch Solaris spurious ACK|FINs 4498 * that web servers like to spew after a close) 4499 * 4500 * This must be a little more careful than the above code 4501 * since packet floods will also be caught here. We don't 4502 * update the TTL here to mitigate the damage of a packet 4503 * flood and so the same code can handle awkward establishment 4504 * and a loosened connection close. 4505 * In the establishment case, a correct peer response will 4506 * validate the connection, go through the normal state code 4507 * and keep updating the state TTL. 4508 */ 4509 4510 if (pf_status.debug >= LOG_NOTICE) { 4511 log(LOG_NOTICE, "pf: loose state match: "); 4512 pf_print_state(*state); 4513 pf_print_flags(th->th_flags); 4514 addlog(" seq=%u (%u) ack=%u len=%u ackskew=%d " 4515 "pkts=%llu:%llu dir=%s,%s\n", seq, orig_seq, ack, 4516 pd->p_len, ackskew, (*state)->packets[0], 4517 (*state)->packets[1], 4518 pd->dir == PF_IN ? "in" : "out", 4519 pd->dir == (*state)->direction ? "fwd" : "rev"); 4520 } 4521 4522 if (dst->scrub || src->scrub) { 4523 if (pf_normalize_tcp_stateful(pd, reason, *state, src, 4524 dst, copyback)) 4525 return (PF_DROP); 4526 } 4527 4528 /* update max window */ 4529 if (src->max_win < win) 4530 src->max_win = win; 4531 /* synchronize sequencing */ 4532 if (SEQ_GT(end, src->seqlo)) 4533 src->seqlo = end; 4534 /* slide the window of what the other end can send */ 4535 if (SEQ_GEQ(ack + (win << sws), dst->seqhi)) 4536 dst->seqhi = ack + MAX((win << sws), 1); 4537 4538 /* 4539 * Cannot set dst->seqhi here since this could be a shotgunned 4540 * SYN and not an already established connection. 4541 */ 4542 if (th->th_flags & TH_FIN) 4543 if (src->state < TCPS_CLOSING) 4544 pf_set_protostate(*state, psrc, TCPS_CLOSING); 4545 if (th->th_flags & TH_RST) 4546 pf_set_protostate(*state, PF_PEER_BOTH, TCPS_TIME_WAIT); 4547 4548 /* Fall through to PASS packet */ 4549 } else { 4550 if ((*state)->dst.state == TCPS_SYN_SENT && 4551 (*state)->src.state == TCPS_SYN_SENT) { 4552 /* Send RST for state mismatches during handshake */ 4553 if (!(th->th_flags & TH_RST)) 4554 pf_send_tcp((*state)->rule.ptr, pd->af, 4555 pd->dst, pd->src, th->th_dport, 4556 th->th_sport, ntohl(th->th_ack), 0, 4557 TH_RST, 0, 0, 4558 (*state)->rule.ptr->return_ttl, 1, 0, 4559 pd->rdomain); 4560 src->seqlo = 0; 4561 src->seqhi = 1; 4562 src->max_win = 1; 4563 } else if (pf_status.debug >= LOG_NOTICE) { 4564 log(LOG_NOTICE, "pf: BAD state: "); 4565 pf_print_state(*state); 4566 pf_print_flags(th->th_flags); 4567 addlog(" seq=%u (%u) ack=%u len=%u ackskew=%d " 4568 "pkts=%llu:%llu dir=%s,%s\n", 4569 seq, orig_seq, ack, pd->p_len, ackskew, 4570 (*state)->packets[0], (*state)->packets[1], 4571 pd->dir == PF_IN ? "in" : "out", 4572 pd->dir == (*state)->direction ? "fwd" : "rev"); 4573 addlog("pf: State failure on: %c %c %c %c | %c %c\n", 4574 SEQ_GEQ(src->seqhi, data_end) ? ' ' : '1', 4575 SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)) ? 4576 ' ': '2', 4577 (ackskew >= -MAXACKWINDOW) ? ' ' : '3', 4578 (ackskew <= (MAXACKWINDOW << sws)) ? ' ' : '4', 4579 SEQ_GEQ(src->seqhi + MAXACKWINDOW, data_end) ? 4580 ' ' :'5', 4581 SEQ_GEQ(seq, src->seqlo - MAXACKWINDOW) ?' ' :'6'); 4582 } 4583 REASON_SET(reason, PFRES_BADSTATE); 4584 return (PF_DROP); 4585 } 4586 4587 return (PF_PASS); 4588 } 4589 4590 int 4591 pf_tcp_track_sloppy(struct pf_pdesc *pd, struct pf_state **state, 4592 u_short *reason) 4593 { 4594 struct tcphdr *th = &pd->hdr.tcp; 4595 struct pf_state_peer *src, *dst; 4596 u_int8_t psrc, pdst; 4597 4598 if (pd->dir == (*state)->direction) { 4599 src = &(*state)->src; 4600 dst = &(*state)->dst; 4601 psrc = PF_PEER_SRC; 4602 pdst = PF_PEER_DST; 4603 } else { 4604 src = &(*state)->dst; 4605 dst = &(*state)->src; 4606 psrc = PF_PEER_DST; 4607 pdst = PF_PEER_SRC; 4608 } 4609 4610 if (th->th_flags & TH_SYN) 4611 if (src->state < TCPS_SYN_SENT) 4612 pf_set_protostate(*state, psrc, TCPS_SYN_SENT); 4613 if (th->th_flags & TH_FIN) 4614 if (src->state < TCPS_CLOSING) 4615 pf_set_protostate(*state, psrc, TCPS_CLOSING); 4616 if (th->th_flags & TH_ACK) { 4617 if (dst->state == TCPS_SYN_SENT) { 4618 pf_set_protostate(*state, pdst, TCPS_ESTABLISHED); 4619 if (src->state == TCPS_ESTABLISHED && 4620 !SLIST_EMPTY(&(*state)->src_nodes) && 4621 pf_src_connlimit(state)) { 4622 REASON_SET(reason, PFRES_SRCLIMIT); 4623 return (PF_DROP); 4624 } 4625 } else if (dst->state == TCPS_CLOSING) { 4626 pf_set_protostate(*state, pdst, TCPS_FIN_WAIT_2); 4627 } else if (src->state == TCPS_SYN_SENT && 4628 dst->state < TCPS_SYN_SENT) { 4629 /* 4630 * Handle a special sloppy case where we only see one 4631 * half of the connection. If there is a ACK after 4632 * the initial SYN without ever seeing a packet from 4633 * the destination, set the connection to established. 4634 */ 4635 pf_set_protostate(*state, PF_PEER_BOTH, 4636 TCPS_ESTABLISHED); 4637 if (!SLIST_EMPTY(&(*state)->src_nodes) && 4638 pf_src_connlimit(state)) { 4639 REASON_SET(reason, PFRES_SRCLIMIT); 4640 return (PF_DROP); 4641 } 4642 } else if (src->state == TCPS_CLOSING && 4643 dst->state == TCPS_ESTABLISHED && 4644 dst->seqlo == 0) { 4645 /* 4646 * Handle the closing of half connections where we 4647 * don't see the full bidirectional FIN/ACK+ACK 4648 * handshake. 4649 */ 4650 pf_set_protostate(*state, pdst, TCPS_CLOSING); 4651 } 4652 } 4653 if (th->th_flags & TH_RST) 4654 pf_set_protostate(*state, PF_PEER_BOTH, TCPS_TIME_WAIT); 4655 4656 /* update expire time */ 4657 (*state)->expire = getuptime(); 4658 if (src->state >= TCPS_FIN_WAIT_2 && 4659 dst->state >= TCPS_FIN_WAIT_2) 4660 (*state)->timeout = PFTM_TCP_CLOSED; 4661 else if (src->state >= TCPS_CLOSING && 4662 dst->state >= TCPS_CLOSING) 4663 (*state)->timeout = PFTM_TCP_FIN_WAIT; 4664 else if (src->state < TCPS_ESTABLISHED || 4665 dst->state < TCPS_ESTABLISHED) 4666 (*state)->timeout = PFTM_TCP_OPENING; 4667 else if (src->state >= TCPS_CLOSING || 4668 dst->state >= TCPS_CLOSING) 4669 (*state)->timeout = PFTM_TCP_CLOSING; 4670 else 4671 (*state)->timeout = PFTM_TCP_ESTABLISHED; 4672 4673 return (PF_PASS); 4674 } 4675 4676 static __inline int 4677 pf_synproxy(struct pf_pdesc *pd, struct pf_state **state, u_short *reason) 4678 { 4679 struct pf_state_key *sk = (*state)->key[pd->didx]; 4680 4681 if ((*state)->src.state == PF_TCPS_PROXY_SRC) { 4682 struct tcphdr *th = &pd->hdr.tcp; 4683 4684 if (pd->dir != (*state)->direction) { 4685 REASON_SET(reason, PFRES_SYNPROXY); 4686 return (PF_SYNPROXY_DROP); 4687 } 4688 if (th->th_flags & TH_SYN) { 4689 if (ntohl(th->th_seq) != (*state)->src.seqlo) { 4690 REASON_SET(reason, PFRES_SYNPROXY); 4691 return (PF_DROP); 4692 } 4693 pf_send_tcp((*state)->rule.ptr, pd->af, pd->dst, 4694 pd->src, th->th_dport, th->th_sport, 4695 (*state)->src.seqhi, ntohl(th->th_seq) + 1, 4696 TH_SYN|TH_ACK, 0, (*state)->src.mss, 0, 1, 4697 0, pd->rdomain); 4698 REASON_SET(reason, PFRES_SYNPROXY); 4699 return (PF_SYNPROXY_DROP); 4700 } else if ((th->th_flags & (TH_ACK|TH_RST|TH_FIN)) != TH_ACK || 4701 (ntohl(th->th_ack) != (*state)->src.seqhi + 1) || 4702 (ntohl(th->th_seq) != (*state)->src.seqlo + 1)) { 4703 REASON_SET(reason, PFRES_SYNPROXY); 4704 return (PF_DROP); 4705 } else if (!SLIST_EMPTY(&(*state)->src_nodes) && 4706 pf_src_connlimit(state)) { 4707 REASON_SET(reason, PFRES_SRCLIMIT); 4708 return (PF_DROP); 4709 } else 4710 pf_set_protostate(*state, PF_PEER_SRC, 4711 PF_TCPS_PROXY_DST); 4712 } 4713 if ((*state)->src.state == PF_TCPS_PROXY_DST) { 4714 struct tcphdr *th = &pd->hdr.tcp; 4715 4716 if (pd->dir == (*state)->direction) { 4717 if (((th->th_flags & (TH_SYN|TH_ACK)) != TH_ACK) || 4718 (ntohl(th->th_ack) != (*state)->src.seqhi + 1) || 4719 (ntohl(th->th_seq) != (*state)->src.seqlo + 1)) { 4720 REASON_SET(reason, PFRES_SYNPROXY); 4721 return (PF_DROP); 4722 } 4723 (*state)->src.max_win = MAX(ntohs(th->th_win), 1); 4724 if ((*state)->dst.seqhi == 1) 4725 (*state)->dst.seqhi = arc4random(); 4726 pf_send_tcp((*state)->rule.ptr, pd->af, 4727 &sk->addr[pd->sidx], &sk->addr[pd->didx], 4728 sk->port[pd->sidx], sk->port[pd->didx], 4729 (*state)->dst.seqhi, 0, TH_SYN, 0, 4730 (*state)->src.mss, 0, 0, (*state)->tag, 4731 sk->rdomain); 4732 REASON_SET(reason, PFRES_SYNPROXY); 4733 return (PF_SYNPROXY_DROP); 4734 } else if (((th->th_flags & (TH_SYN|TH_ACK)) != 4735 (TH_SYN|TH_ACK)) || 4736 (ntohl(th->th_ack) != (*state)->dst.seqhi + 1)) { 4737 REASON_SET(reason, PFRES_SYNPROXY); 4738 return (PF_DROP); 4739 } else { 4740 (*state)->dst.max_win = MAX(ntohs(th->th_win), 1); 4741 (*state)->dst.seqlo = ntohl(th->th_seq); 4742 pf_send_tcp((*state)->rule.ptr, pd->af, pd->dst, 4743 pd->src, th->th_dport, th->th_sport, 4744 ntohl(th->th_ack), ntohl(th->th_seq) + 1, 4745 TH_ACK, (*state)->src.max_win, 0, 0, 0, 4746 (*state)->tag, pd->rdomain); 4747 pf_send_tcp((*state)->rule.ptr, pd->af, 4748 &sk->addr[pd->sidx], &sk->addr[pd->didx], 4749 sk->port[pd->sidx], sk->port[pd->didx], 4750 (*state)->src.seqhi + 1, (*state)->src.seqlo + 1, 4751 TH_ACK, (*state)->dst.max_win, 0, 0, 1, 4752 0, sk->rdomain); 4753 (*state)->src.seqdiff = (*state)->dst.seqhi - 4754 (*state)->src.seqlo; 4755 (*state)->dst.seqdiff = (*state)->src.seqhi - 4756 (*state)->dst.seqlo; 4757 (*state)->src.seqhi = (*state)->src.seqlo + 4758 (*state)->dst.max_win; 4759 (*state)->dst.seqhi = (*state)->dst.seqlo + 4760 (*state)->src.max_win; 4761 (*state)->src.wscale = (*state)->dst.wscale = 0; 4762 pf_set_protostate(*state, PF_PEER_BOTH, 4763 TCPS_ESTABLISHED); 4764 REASON_SET(reason, PFRES_SYNPROXY); 4765 return (PF_SYNPROXY_DROP); 4766 } 4767 } 4768 return (PF_PASS); 4769 } 4770 4771 int 4772 pf_test_state(struct pf_pdesc *pd, struct pf_state **state, u_short *reason, 4773 int syncookie) 4774 { 4775 struct pf_state_key_cmp key; 4776 int copyback = 0; 4777 struct pf_state_peer *src, *dst; 4778 int action; 4779 struct inpcb *inp; 4780 u_int8_t psrc, pdst; 4781 4782 key.af = pd->af; 4783 key.proto = pd->virtual_proto; 4784 key.rdomain = pd->rdomain; 4785 pf_addrcpy(&key.addr[pd->sidx], pd->src, key.af); 4786 pf_addrcpy(&key.addr[pd->didx], pd->dst, key.af); 4787 key.port[pd->sidx] = pd->osport; 4788 key.port[pd->didx] = pd->odport; 4789 inp = pd->m->m_pkthdr.pf.inp; 4790 4791 action = pf_find_state(pd, &key, state); 4792 if (action != PF_MATCH) 4793 return (action); 4794 4795 action = PF_PASS; 4796 if (pd->dir == (*state)->direction) { 4797 src = &(*state)->src; 4798 dst = &(*state)->dst; 4799 psrc = PF_PEER_SRC; 4800 pdst = PF_PEER_DST; 4801 } else { 4802 src = &(*state)->dst; 4803 dst = &(*state)->src; 4804 psrc = PF_PEER_DST; 4805 pdst = PF_PEER_SRC; 4806 } 4807 4808 switch (pd->virtual_proto) { 4809 case IPPROTO_TCP: 4810 if (syncookie) { 4811 pf_set_protostate(*state, PF_PEER_SRC, 4812 PF_TCPS_PROXY_DST); 4813 (*state)->dst.seqhi = ntohl(pd->hdr.tcp.th_ack) - 1; 4814 } 4815 if ((action = pf_synproxy(pd, state, reason)) != PF_PASS) 4816 return (action); 4817 if ((pd->hdr.tcp.th_flags & (TH_SYN|TH_ACK)) == TH_SYN) { 4818 4819 if (dst->state >= TCPS_FIN_WAIT_2 && 4820 src->state >= TCPS_FIN_WAIT_2) { 4821 if (pf_status.debug >= LOG_NOTICE) { 4822 log(LOG_NOTICE, "pf: state reuse "); 4823 pf_print_state(*state); 4824 pf_print_flags(pd->hdr.tcp.th_flags); 4825 addlog("\n"); 4826 } 4827 /* XXX make sure it's the same direction ?? */ 4828 (*state)->timeout = PFTM_PURGE; 4829 *state = NULL; 4830 pf_mbuf_link_inpcb(pd->m, inp); 4831 return (PF_DROP); 4832 } else if (dst->state >= TCPS_ESTABLISHED && 4833 src->state >= TCPS_ESTABLISHED) { 4834 /* 4835 * SYN matches existing state??? 4836 * Typically happens when sender boots up after 4837 * sudden panic. Certain protocols (NFSv3) are 4838 * always using same port numbers. Challenge 4839 * ACK enables all parties (firewall and peers) 4840 * to get in sync again. 4841 */ 4842 pf_send_challenge_ack(pd, *state, src, dst); 4843 return (PF_DROP); 4844 } 4845 } 4846 4847 if ((*state)->state_flags & PFSTATE_SLOPPY) { 4848 if (pf_tcp_track_sloppy(pd, state, reason) == PF_DROP) 4849 return (PF_DROP); 4850 } else { 4851 if (pf_tcp_track_full(pd, state, reason, ©back, 4852 PF_REVERSED_KEY((*state)->key, pd->af)) == PF_DROP) 4853 return (PF_DROP); 4854 } 4855 break; 4856 case IPPROTO_UDP: 4857 /* update states */ 4858 if (src->state < PFUDPS_SINGLE) 4859 pf_set_protostate(*state, psrc, PFUDPS_SINGLE); 4860 if (dst->state == PFUDPS_SINGLE) 4861 pf_set_protostate(*state, pdst, PFUDPS_MULTIPLE); 4862 4863 /* update expire time */ 4864 (*state)->expire = getuptime(); 4865 if (src->state == PFUDPS_MULTIPLE && 4866 dst->state == PFUDPS_MULTIPLE) 4867 (*state)->timeout = PFTM_UDP_MULTIPLE; 4868 else 4869 (*state)->timeout = PFTM_UDP_SINGLE; 4870 break; 4871 default: 4872 /* update states */ 4873 if (src->state < PFOTHERS_SINGLE) 4874 pf_set_protostate(*state, psrc, PFOTHERS_SINGLE); 4875 if (dst->state == PFOTHERS_SINGLE) 4876 pf_set_protostate(*state, pdst, PFOTHERS_MULTIPLE); 4877 4878 /* update expire time */ 4879 (*state)->expire = getuptime(); 4880 if (src->state == PFOTHERS_MULTIPLE && 4881 dst->state == PFOTHERS_MULTIPLE) 4882 (*state)->timeout = PFTM_OTHER_MULTIPLE; 4883 else 4884 (*state)->timeout = PFTM_OTHER_SINGLE; 4885 break; 4886 } 4887 4888 /* translate source/destination address, if necessary */ 4889 if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) { 4890 struct pf_state_key *nk; 4891 int afto, sidx, didx; 4892 4893 if (PF_REVERSED_KEY((*state)->key, pd->af)) 4894 nk = (*state)->key[pd->sidx]; 4895 else 4896 nk = (*state)->key[pd->didx]; 4897 4898 afto = pd->af != nk->af; 4899 sidx = afto ? pd->didx : pd->sidx; 4900 didx = afto ? pd->sidx : pd->didx; 4901 4902 #ifdef INET6 4903 if (afto) { 4904 pf_addrcpy(&pd->nsaddr, &nk->addr[sidx], nk->af); 4905 pf_addrcpy(&pd->ndaddr, &nk->addr[didx], nk->af); 4906 pd->naf = nk->af; 4907 action = PF_AFRT; 4908 } 4909 #endif /* INET6 */ 4910 4911 if (!afto) 4912 pf_translate_a(pd, pd->src, &nk->addr[sidx]); 4913 4914 if (pd->sport != NULL) 4915 pf_patch_16(pd, pd->sport, nk->port[sidx]); 4916 4917 if (afto || PF_ANEQ(pd->dst, &nk->addr[didx], pd->af) || 4918 pd->rdomain != nk->rdomain) 4919 pd->destchg = 1; 4920 4921 if (!afto) 4922 pf_translate_a(pd, pd->dst, &nk->addr[didx]); 4923 4924 if (pd->dport != NULL) 4925 pf_patch_16(pd, pd->dport, nk->port[didx]); 4926 4927 pd->m->m_pkthdr.ph_rtableid = nk->rdomain; 4928 copyback = 1; 4929 } 4930 4931 if (copyback && pd->hdrlen > 0) { 4932 m_copyback(pd->m, pd->off, pd->hdrlen, &pd->hdr, M_NOWAIT); 4933 } 4934 4935 return (action); 4936 } 4937 4938 int 4939 pf_icmp_state_lookup(struct pf_pdesc *pd, struct pf_state_key_cmp *key, 4940 struct pf_state **state, u_int16_t icmpid, u_int16_t type, 4941 int icmp_dir, int *iidx, int multi, int inner) 4942 { 4943 int direction, action; 4944 4945 key->af = pd->af; 4946 key->proto = pd->proto; 4947 key->rdomain = pd->rdomain; 4948 if (icmp_dir == PF_IN) { 4949 *iidx = pd->sidx; 4950 key->port[pd->sidx] = icmpid; 4951 key->port[pd->didx] = type; 4952 } else { 4953 *iidx = pd->didx; 4954 key->port[pd->sidx] = type; 4955 key->port[pd->didx] = icmpid; 4956 } 4957 4958 if (pf_state_key_addr_setup(pd, key, pd->sidx, pd->src, pd->didx, 4959 pd->dst, pd->af, multi)) 4960 return (PF_DROP); 4961 4962 action = pf_find_state(pd, key, state); 4963 if (action != PF_MATCH) 4964 return (action); 4965 4966 if ((*state)->state_flags & PFSTATE_SLOPPY) 4967 return (-1); 4968 4969 /* Is this ICMP message flowing in right direction? */ 4970 if ((*state)->key[PF_SK_WIRE]->af != (*state)->key[PF_SK_STACK]->af) 4971 direction = (pd->af == (*state)->key[PF_SK_WIRE]->af) ? 4972 PF_IN : PF_OUT; 4973 else 4974 direction = (*state)->direction; 4975 if ((((!inner && direction == pd->dir) || 4976 (inner && direction != pd->dir)) ? 4977 PF_IN : PF_OUT) != icmp_dir) { 4978 if (pf_status.debug >= LOG_NOTICE) { 4979 log(LOG_NOTICE, 4980 "pf: icmp type %d in wrong direction (%d): ", 4981 ntohs(type), icmp_dir); 4982 pf_print_state(*state); 4983 addlog("\n"); 4984 } 4985 return (PF_DROP); 4986 } 4987 return (-1); 4988 } 4989 4990 int 4991 pf_test_state_icmp(struct pf_pdesc *pd, struct pf_state **state, 4992 u_short *reason) 4993 { 4994 u_int16_t virtual_id, virtual_type; 4995 u_int8_t icmptype, icmpcode; 4996 int icmp_dir, iidx, ret, copyback = 0; 4997 4998 struct pf_state_key_cmp key; 4999 5000 switch (pd->proto) { 5001 case IPPROTO_ICMP: 5002 icmptype = pd->hdr.icmp.icmp_type; 5003 icmpcode = pd->hdr.icmp.icmp_code; 5004 break; 5005 #ifdef INET6 5006 case IPPROTO_ICMPV6: 5007 icmptype = pd->hdr.icmp6.icmp6_type; 5008 icmpcode = pd->hdr.icmp6.icmp6_code; 5009 break; 5010 #endif /* INET6 */ 5011 default: 5012 panic("unhandled proto %d", pd->proto); 5013 } 5014 5015 if (pf_icmp_mapping(pd, icmptype, &icmp_dir, &virtual_id, 5016 &virtual_type) == 0) { 5017 /* 5018 * ICMP query/reply message not related to a TCP/UDP packet. 5019 * Search for an ICMP state. 5020 */ 5021 ret = pf_icmp_state_lookup(pd, &key, state, 5022 virtual_id, virtual_type, icmp_dir, &iidx, 5023 0, 0); 5024 /* IPv6? try matching a multicast address */ 5025 if (ret == PF_DROP && pd->af == AF_INET6 && icmp_dir == PF_OUT) 5026 ret = pf_icmp_state_lookup(pd, &key, state, virtual_id, 5027 virtual_type, icmp_dir, &iidx, 1, 0); 5028 if (ret >= 0) 5029 return (ret); 5030 5031 (*state)->expire = getuptime(); 5032 (*state)->timeout = PFTM_ICMP_ERROR_REPLY; 5033 5034 /* translate source/destination address, if necessary */ 5035 if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) { 5036 struct pf_state_key *nk; 5037 int afto, sidx, didx; 5038 5039 if (PF_REVERSED_KEY((*state)->key, pd->af)) 5040 nk = (*state)->key[pd->sidx]; 5041 else 5042 nk = (*state)->key[pd->didx]; 5043 5044 afto = pd->af != nk->af; 5045 sidx = afto ? pd->didx : pd->sidx; 5046 didx = afto ? pd->sidx : pd->didx; 5047 iidx = afto ? !iidx : iidx; 5048 #ifdef INET6 5049 if (afto) { 5050 pf_addrcpy(&pd->nsaddr, &nk->addr[sidx], 5051 nk->af); 5052 pf_addrcpy(&pd->ndaddr, &nk->addr[didx], 5053 nk->af); 5054 pd->naf = nk->af; 5055 } 5056 #endif /* INET6 */ 5057 if (!afto) { 5058 pf_translate_a(pd, pd->src, &nk->addr[sidx]); 5059 pf_translate_a(pd, pd->dst, &nk->addr[didx]); 5060 } 5061 5062 if (pd->rdomain != nk->rdomain) 5063 pd->destchg = 1; 5064 if (!afto && PF_ANEQ(pd->dst, 5065 &nk->addr[didx], pd->af)) 5066 pd->destchg = 1; 5067 pd->m->m_pkthdr.ph_rtableid = nk->rdomain; 5068 5069 switch (pd->af) { 5070 case AF_INET: 5071 #ifdef INET6 5072 if (afto) { 5073 if (pf_translate_icmp_af(pd, AF_INET6, 5074 &pd->hdr.icmp)) 5075 return (PF_DROP); 5076 pd->proto = IPPROTO_ICMPV6; 5077 } 5078 #endif /* INET6 */ 5079 pf_patch_16(pd, 5080 &pd->hdr.icmp.icmp_id, nk->port[iidx]); 5081 5082 m_copyback(pd->m, pd->off, ICMP_MINLEN, 5083 &pd->hdr.icmp, M_NOWAIT); 5084 copyback = 1; 5085 break; 5086 #ifdef INET6 5087 case AF_INET6: 5088 if (afto) { 5089 if (pf_translate_icmp_af(pd, AF_INET, 5090 &pd->hdr.icmp6)) 5091 return (PF_DROP); 5092 pd->proto = IPPROTO_ICMP; 5093 } 5094 5095 pf_patch_16(pd, 5096 &pd->hdr.icmp6.icmp6_id, nk->port[iidx]); 5097 5098 m_copyback(pd->m, pd->off, 5099 sizeof(struct icmp6_hdr), &pd->hdr.icmp6, 5100 M_NOWAIT); 5101 copyback = 1; 5102 break; 5103 #endif /* INET6 */ 5104 } 5105 #ifdef INET6 5106 if (afto) 5107 return (PF_AFRT); 5108 #endif /* INET6 */ 5109 } 5110 } else { 5111 /* 5112 * ICMP error message in response to a TCP/UDP packet. 5113 * Extract the inner TCP/UDP header and search for that state. 5114 */ 5115 struct pf_pdesc pd2; 5116 struct ip h2; 5117 #ifdef INET6 5118 struct ip6_hdr h2_6; 5119 #endif /* INET6 */ 5120 int ipoff2; 5121 5122 /* Initialize pd2 fields valid for both packets with pd. */ 5123 memset(&pd2, 0, sizeof(pd2)); 5124 pd2.af = pd->af; 5125 pd2.dir = pd->dir; 5126 pd2.kif = pd->kif; 5127 pd2.m = pd->m; 5128 pd2.rdomain = pd->rdomain; 5129 /* Payload packet is from the opposite direction. */ 5130 pd2.sidx = (pd2.dir == PF_IN) ? 1 : 0; 5131 pd2.didx = (pd2.dir == PF_IN) ? 0 : 1; 5132 switch (pd->af) { 5133 case AF_INET: 5134 /* offset of h2 in mbuf chain */ 5135 ipoff2 = pd->off + ICMP_MINLEN; 5136 5137 if (!pf_pull_hdr(pd2.m, ipoff2, &h2, sizeof(h2), 5138 NULL, reason, pd2.af)) { 5139 DPFPRINTF(LOG_NOTICE, 5140 "ICMP error message too short (ip)"); 5141 return (PF_DROP); 5142 } 5143 /* 5144 * ICMP error messages don't refer to non-first 5145 * fragments 5146 */ 5147 if (h2.ip_off & htons(IP_OFFMASK)) { 5148 REASON_SET(reason, PFRES_FRAG); 5149 return (PF_DROP); 5150 } 5151 5152 /* offset of protocol header that follows h2 */ 5153 pd2.off = ipoff2; 5154 if (pf_walk_header(&pd2, &h2, reason) != PF_PASS) 5155 return (PF_DROP); 5156 5157 pd2.tot_len = ntohs(h2.ip_len); 5158 pd2.src = (struct pf_addr *)&h2.ip_src; 5159 pd2.dst = (struct pf_addr *)&h2.ip_dst; 5160 break; 5161 #ifdef INET6 5162 case AF_INET6: 5163 ipoff2 = pd->off + sizeof(struct icmp6_hdr); 5164 5165 if (!pf_pull_hdr(pd2.m, ipoff2, &h2_6, sizeof(h2_6), 5166 NULL, reason, pd2.af)) { 5167 DPFPRINTF(LOG_NOTICE, 5168 "ICMP error message too short (ip6)"); 5169 return (PF_DROP); 5170 } 5171 5172 pd2.off = ipoff2; 5173 if (pf_walk_header6(&pd2, &h2_6, reason) != PF_PASS) 5174 return (PF_DROP); 5175 5176 pd2.tot_len = ntohs(h2_6.ip6_plen) + 5177 sizeof(struct ip6_hdr); 5178 pd2.src = (struct pf_addr *)&h2_6.ip6_src; 5179 pd2.dst = (struct pf_addr *)&h2_6.ip6_dst; 5180 break; 5181 #endif /* INET6 */ 5182 default: 5183 unhandled_af(pd->af); 5184 } 5185 5186 if (PF_ANEQ(pd->dst, pd2.src, pd->af)) { 5187 if (pf_status.debug >= LOG_NOTICE) { 5188 log(LOG_NOTICE, 5189 "pf: BAD ICMP %d:%d outer dst: ", 5190 icmptype, icmpcode); 5191 pf_print_host(pd->src, 0, pd->af); 5192 addlog(" -> "); 5193 pf_print_host(pd->dst, 0, pd->af); 5194 addlog(" inner src: "); 5195 pf_print_host(pd2.src, 0, pd2.af); 5196 addlog(" -> "); 5197 pf_print_host(pd2.dst, 0, pd2.af); 5198 addlog("\n"); 5199 } 5200 REASON_SET(reason, PFRES_BADSTATE); 5201 return (PF_DROP); 5202 } 5203 5204 switch (pd2.proto) { 5205 case IPPROTO_TCP: { 5206 struct tcphdr *th = &pd2.hdr.tcp; 5207 u_int32_t seq; 5208 struct pf_state_peer *src, *dst; 5209 u_int8_t dws; 5210 int action; 5211 5212 /* 5213 * Only the first 8 bytes of the TCP header can be 5214 * expected. Don't access any TCP header fields after 5215 * th_seq, an ackskew test is not possible. 5216 */ 5217 if (!pf_pull_hdr(pd2.m, pd2.off, th, 8, NULL, reason, 5218 pd2.af)) { 5219 DPFPRINTF(LOG_NOTICE, 5220 "ICMP error message too short (tcp)"); 5221 return (PF_DROP); 5222 } 5223 5224 key.af = pd2.af; 5225 key.proto = IPPROTO_TCP; 5226 key.rdomain = pd2.rdomain; 5227 pf_addrcpy(&key.addr[pd2.sidx], pd2.src, key.af); 5228 pf_addrcpy(&key.addr[pd2.didx], pd2.dst, key.af); 5229 key.port[pd2.sidx] = th->th_sport; 5230 key.port[pd2.didx] = th->th_dport; 5231 5232 action = pf_find_state(&pd2, &key, state); 5233 if (action != PF_MATCH) 5234 return (action); 5235 5236 if (pd2.dir == (*state)->direction) { 5237 if (PF_REVERSED_KEY((*state)->key, pd->af)) { 5238 src = &(*state)->src; 5239 dst = &(*state)->dst; 5240 } else { 5241 src = &(*state)->dst; 5242 dst = &(*state)->src; 5243 } 5244 } else { 5245 if (PF_REVERSED_KEY((*state)->key, pd->af)) { 5246 src = &(*state)->dst; 5247 dst = &(*state)->src; 5248 } else { 5249 src = &(*state)->src; 5250 dst = &(*state)->dst; 5251 } 5252 } 5253 5254 if (src->wscale && dst->wscale) 5255 dws = dst->wscale & PF_WSCALE_MASK; 5256 else 5257 dws = 0; 5258 5259 /* Demodulate sequence number */ 5260 seq = ntohl(th->th_seq) - src->seqdiff; 5261 if (src->seqdiff) { 5262 pf_patch_32(pd, &th->th_seq, htonl(seq)); 5263 copyback = 1; 5264 } 5265 5266 if (!((*state)->state_flags & PFSTATE_SLOPPY) && 5267 (!SEQ_GEQ(src->seqhi, seq) || !SEQ_GEQ(seq, 5268 src->seqlo - (dst->max_win << dws)))) { 5269 if (pf_status.debug >= LOG_NOTICE) { 5270 log(LOG_NOTICE, 5271 "pf: BAD ICMP %d:%d ", 5272 icmptype, icmpcode); 5273 pf_print_host(pd->src, 0, pd->af); 5274 addlog(" -> "); 5275 pf_print_host(pd->dst, 0, pd->af); 5276 addlog(" state: "); 5277 pf_print_state(*state); 5278 addlog(" seq=%u\n", seq); 5279 } 5280 REASON_SET(reason, PFRES_BADSTATE); 5281 return (PF_DROP); 5282 } else { 5283 if (pf_status.debug >= LOG_DEBUG) { 5284 log(LOG_DEBUG, 5285 "pf: OK ICMP %d:%d ", 5286 icmptype, icmpcode); 5287 pf_print_host(pd->src, 0, pd->af); 5288 addlog(" -> "); 5289 pf_print_host(pd->dst, 0, pd->af); 5290 addlog(" state: "); 5291 pf_print_state(*state); 5292 addlog(" seq=%u\n", seq); 5293 } 5294 } 5295 5296 /* translate source/destination address, if necessary */ 5297 if ((*state)->key[PF_SK_WIRE] != 5298 (*state)->key[PF_SK_STACK]) { 5299 struct pf_state_key *nk; 5300 int afto, sidx, didx; 5301 5302 if (PF_REVERSED_KEY((*state)->key, pd->af)) 5303 nk = (*state)->key[pd->sidx]; 5304 else 5305 nk = (*state)->key[pd->didx]; 5306 5307 afto = pd->af != nk->af; 5308 sidx = afto ? pd2.didx : pd2.sidx; 5309 didx = afto ? pd2.sidx : pd2.didx; 5310 5311 #ifdef INET6 5312 if (afto) { 5313 if (pf_translate_icmp_af(pd, nk->af, 5314 &pd->hdr.icmp)) 5315 return (PF_DROP); 5316 m_copyback(pd->m, pd->off, 5317 sizeof(struct icmp6_hdr), 5318 &pd->hdr.icmp6, M_NOWAIT); 5319 if (pf_change_icmp_af(pd->m, ipoff2, 5320 pd, &pd2, &nk->addr[sidx], 5321 &nk->addr[didx], pd->af, nk->af)) 5322 return (PF_DROP); 5323 if (nk->af == AF_INET) 5324 pd->proto = IPPROTO_ICMP; 5325 else 5326 pd->proto = IPPROTO_ICMPV6; 5327 pd->m->m_pkthdr.ph_rtableid = 5328 nk->rdomain; 5329 pd->destchg = 1; 5330 pf_addrcpy(&pd->nsaddr, 5331 &nk->addr[pd2.sidx], nk->af); 5332 pf_addrcpy(&pd->ndaddr, 5333 &nk->addr[pd2.didx], nk->af); 5334 pd->naf = nk->af; 5335 5336 pf_patch_16(pd, 5337 &th->th_sport, nk->port[sidx]); 5338 pf_patch_16(pd, 5339 &th->th_dport, nk->port[didx]); 5340 5341 m_copyback(pd2.m, pd2.off, 8, th, 5342 M_NOWAIT); 5343 return (PF_AFRT); 5344 } 5345 #endif /* INET6 */ 5346 if (PF_ANEQ(pd2.src, 5347 &nk->addr[pd2.sidx], pd2.af) || 5348 nk->port[pd2.sidx] != th->th_sport) 5349 pf_translate_icmp(pd, pd2.src, 5350 &th->th_sport, pd->dst, 5351 &nk->addr[pd2.sidx], 5352 nk->port[pd2.sidx]); 5353 5354 if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], 5355 pd2.af) || pd2.rdomain != nk->rdomain) 5356 pd->destchg = 1; 5357 pd->m->m_pkthdr.ph_rtableid = nk->rdomain; 5358 5359 if (PF_ANEQ(pd2.dst, 5360 &nk->addr[pd2.didx], pd2.af) || 5361 nk->port[pd2.didx] != th->th_dport) 5362 pf_translate_icmp(pd, pd2.dst, 5363 &th->th_dport, pd->src, 5364 &nk->addr[pd2.didx], 5365 nk->port[pd2.didx]); 5366 copyback = 1; 5367 } 5368 5369 if (copyback) { 5370 switch (pd2.af) { 5371 case AF_INET: 5372 m_copyback(pd->m, pd->off, ICMP_MINLEN, 5373 &pd->hdr.icmp, M_NOWAIT); 5374 m_copyback(pd2.m, ipoff2, sizeof(h2), 5375 &h2, M_NOWAIT); 5376 break; 5377 #ifdef INET6 5378 case AF_INET6: 5379 m_copyback(pd->m, pd->off, 5380 sizeof(struct icmp6_hdr), 5381 &pd->hdr.icmp6, M_NOWAIT); 5382 m_copyback(pd2.m, ipoff2, sizeof(h2_6), 5383 &h2_6, M_NOWAIT); 5384 break; 5385 #endif /* INET6 */ 5386 } 5387 m_copyback(pd2.m, pd2.off, 8, th, M_NOWAIT); 5388 } 5389 break; 5390 } 5391 case IPPROTO_UDP: { 5392 struct udphdr *uh = &pd2.hdr.udp; 5393 int action; 5394 5395 if (!pf_pull_hdr(pd2.m, pd2.off, uh, sizeof(*uh), 5396 NULL, reason, pd2.af)) { 5397 DPFPRINTF(LOG_NOTICE, 5398 "ICMP error message too short (udp)"); 5399 return (PF_DROP); 5400 } 5401 5402 key.af = pd2.af; 5403 key.proto = IPPROTO_UDP; 5404 key.rdomain = pd2.rdomain; 5405 pf_addrcpy(&key.addr[pd2.sidx], pd2.src, key.af); 5406 pf_addrcpy(&key.addr[pd2.didx], pd2.dst, key.af); 5407 key.port[pd2.sidx] = uh->uh_sport; 5408 key.port[pd2.didx] = uh->uh_dport; 5409 5410 action = pf_find_state(&pd2, &key, state); 5411 if (action != PF_MATCH) 5412 return (action); 5413 5414 /* translate source/destination address, if necessary */ 5415 if ((*state)->key[PF_SK_WIRE] != 5416 (*state)->key[PF_SK_STACK]) { 5417 struct pf_state_key *nk; 5418 int afto, sidx, didx; 5419 5420 if (PF_REVERSED_KEY((*state)->key, pd->af)) 5421 nk = (*state)->key[pd->sidx]; 5422 else 5423 nk = (*state)->key[pd->didx]; 5424 5425 afto = pd->af != nk->af; 5426 sidx = afto ? pd2.didx : pd2.sidx; 5427 didx = afto ? pd2.sidx : pd2.didx; 5428 5429 #ifdef INET6 5430 if (afto) { 5431 if (pf_translate_icmp_af(pd, nk->af, 5432 &pd->hdr.icmp)) 5433 return (PF_DROP); 5434 m_copyback(pd->m, pd->off, 5435 sizeof(struct icmp6_hdr), 5436 &pd->hdr.icmp6, M_NOWAIT); 5437 if (pf_change_icmp_af(pd->m, ipoff2, 5438 pd, &pd2, &nk->addr[sidx], 5439 &nk->addr[didx], pd->af, nk->af)) 5440 return (PF_DROP); 5441 if (nk->af == AF_INET) 5442 pd->proto = IPPROTO_ICMP; 5443 else 5444 pd->proto = IPPROTO_ICMPV6; 5445 pd->m->m_pkthdr.ph_rtableid = 5446 nk->rdomain; 5447 pd->destchg = 1; 5448 pf_addrcpy(&pd->nsaddr, 5449 &nk->addr[pd2.sidx], nk->af); 5450 pf_addrcpy(&pd->ndaddr, 5451 &nk->addr[pd2.didx], nk->af); 5452 pd->naf = nk->af; 5453 5454 pf_patch_16(pd, 5455 &uh->uh_sport, nk->port[sidx]); 5456 pf_patch_16(pd, 5457 &uh->uh_dport, nk->port[didx]); 5458 5459 m_copyback(pd2.m, pd2.off, sizeof(*uh), 5460 uh, M_NOWAIT); 5461 return (PF_AFRT); 5462 } 5463 #endif /* INET6 */ 5464 5465 if (PF_ANEQ(pd2.src, 5466 &nk->addr[pd2.sidx], pd2.af) || 5467 nk->port[pd2.sidx] != uh->uh_sport) 5468 pf_translate_icmp(pd, pd2.src, 5469 &uh->uh_sport, pd->dst, 5470 &nk->addr[pd2.sidx], 5471 nk->port[pd2.sidx]); 5472 5473 if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], 5474 pd2.af) || pd2.rdomain != nk->rdomain) 5475 pd->destchg = 1; 5476 pd->m->m_pkthdr.ph_rtableid = nk->rdomain; 5477 5478 if (PF_ANEQ(pd2.dst, 5479 &nk->addr[pd2.didx], pd2.af) || 5480 nk->port[pd2.didx] != uh->uh_dport) 5481 pf_translate_icmp(pd, pd2.dst, 5482 &uh->uh_dport, pd->src, 5483 &nk->addr[pd2.didx], 5484 nk->port[pd2.didx]); 5485 5486 switch (pd2.af) { 5487 case AF_INET: 5488 m_copyback(pd->m, pd->off, ICMP_MINLEN, 5489 &pd->hdr.icmp, M_NOWAIT); 5490 m_copyback(pd2.m, ipoff2, sizeof(h2), 5491 &h2, M_NOWAIT); 5492 break; 5493 #ifdef INET6 5494 case AF_INET6: 5495 m_copyback(pd->m, pd->off, 5496 sizeof(struct icmp6_hdr), 5497 &pd->hdr.icmp6, M_NOWAIT); 5498 m_copyback(pd2.m, ipoff2, sizeof(h2_6), 5499 &h2_6, M_NOWAIT); 5500 break; 5501 #endif /* INET6 */ 5502 } 5503 /* Avoid recomputing quoted UDP checksum. 5504 * note: udp6 0 csum invalid per rfc2460 p27. 5505 * but presumed nothing cares in this context */ 5506 pf_patch_16(pd, &uh->uh_sum, 0); 5507 m_copyback(pd2.m, pd2.off, sizeof(*uh), uh, 5508 M_NOWAIT); 5509 copyback = 1; 5510 } 5511 break; 5512 } 5513 case IPPROTO_ICMP: { 5514 struct icmp *iih = &pd2.hdr.icmp; 5515 5516 if (pd2.af != AF_INET) { 5517 REASON_SET(reason, PFRES_NORM); 5518 return (PF_DROP); 5519 } 5520 5521 if (!pf_pull_hdr(pd2.m, pd2.off, iih, ICMP_MINLEN, 5522 NULL, reason, pd2.af)) { 5523 DPFPRINTF(LOG_NOTICE, 5524 "ICMP error message too short (icmp)"); 5525 return (PF_DROP); 5526 } 5527 5528 pf_icmp_mapping(&pd2, iih->icmp_type, 5529 &icmp_dir, &virtual_id, &virtual_type); 5530 5531 ret = pf_icmp_state_lookup(&pd2, &key, state, 5532 virtual_id, virtual_type, icmp_dir, &iidx, 0, 1); 5533 if (ret >= 0) 5534 return (ret); 5535 5536 /* translate source/destination address, if necessary */ 5537 if ((*state)->key[PF_SK_WIRE] != 5538 (*state)->key[PF_SK_STACK]) { 5539 struct pf_state_key *nk; 5540 int afto, sidx, didx; 5541 5542 if (PF_REVERSED_KEY((*state)->key, pd->af)) 5543 nk = (*state)->key[pd->sidx]; 5544 else 5545 nk = (*state)->key[pd->didx]; 5546 5547 afto = pd->af != nk->af; 5548 sidx = afto ? pd2.didx : pd2.sidx; 5549 didx = afto ? pd2.sidx : pd2.didx; 5550 iidx = afto ? !iidx : iidx; 5551 5552 #ifdef INET6 5553 if (afto) { 5554 if (nk->af != AF_INET6) 5555 return (PF_DROP); 5556 if (pf_translate_icmp_af(pd, nk->af, 5557 &pd->hdr.icmp)) 5558 return (PF_DROP); 5559 m_copyback(pd->m, pd->off, 5560 sizeof(struct icmp6_hdr), 5561 &pd->hdr.icmp6, M_NOWAIT); 5562 if (pf_change_icmp_af(pd->m, ipoff2, 5563 pd, &pd2, &nk->addr[sidx], 5564 &nk->addr[didx], pd->af, nk->af)) 5565 return (PF_DROP); 5566 pd->proto = IPPROTO_ICMPV6; 5567 if (pf_translate_icmp_af(pd, 5568 nk->af, iih)) 5569 return (PF_DROP); 5570 if (virtual_type == htons(ICMP_ECHO)) 5571 pf_patch_16(pd, &iih->icmp_id, 5572 nk->port[iidx]); 5573 m_copyback(pd2.m, pd2.off, ICMP_MINLEN, 5574 iih, M_NOWAIT); 5575 pd->m->m_pkthdr.ph_rtableid = 5576 nk->rdomain; 5577 pd->destchg = 1; 5578 pf_addrcpy(&pd->nsaddr, 5579 &nk->addr[pd2.sidx], nk->af); 5580 pf_addrcpy(&pd->ndaddr, 5581 &nk->addr[pd2.didx], nk->af); 5582 pd->naf = nk->af; 5583 return (PF_AFRT); 5584 } 5585 #endif /* INET6 */ 5586 5587 if (PF_ANEQ(pd2.src, 5588 &nk->addr[pd2.sidx], pd2.af) || 5589 (virtual_type == htons(ICMP_ECHO) && 5590 nk->port[iidx] != iih->icmp_id)) 5591 pf_translate_icmp(pd, pd2.src, 5592 (virtual_type == htons(ICMP_ECHO)) ? 5593 &iih->icmp_id : NULL, 5594 pd->dst, &nk->addr[pd2.sidx], 5595 (virtual_type == htons(ICMP_ECHO)) ? 5596 nk->port[iidx] : 0); 5597 5598 if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], 5599 pd2.af) || pd2.rdomain != nk->rdomain) 5600 pd->destchg = 1; 5601 pd->m->m_pkthdr.ph_rtableid = nk->rdomain; 5602 5603 if (PF_ANEQ(pd2.dst, 5604 &nk->addr[pd2.didx], pd2.af)) 5605 pf_translate_icmp(pd, pd2.dst, NULL, 5606 pd->src, &nk->addr[pd2.didx], 0); 5607 5608 m_copyback(pd->m, pd->off, ICMP_MINLEN, 5609 &pd->hdr.icmp, M_NOWAIT); 5610 m_copyback(pd2.m, ipoff2, sizeof(h2), &h2, 5611 M_NOWAIT); 5612 m_copyback(pd2.m, pd2.off, ICMP_MINLEN, iih, 5613 M_NOWAIT); 5614 copyback = 1; 5615 } 5616 break; 5617 } 5618 #ifdef INET6 5619 case IPPROTO_ICMPV6: { 5620 struct icmp6_hdr *iih = &pd2.hdr.icmp6; 5621 5622 if (pd2.af != AF_INET6) { 5623 REASON_SET(reason, PFRES_NORM); 5624 return (PF_DROP); 5625 } 5626 5627 if (!pf_pull_hdr(pd2.m, pd2.off, iih, 5628 sizeof(struct icmp6_hdr), NULL, reason, pd2.af)) { 5629 DPFPRINTF(LOG_NOTICE, 5630 "ICMP error message too short (icmp6)"); 5631 return (PF_DROP); 5632 } 5633 5634 pf_icmp_mapping(&pd2, iih->icmp6_type, 5635 &icmp_dir, &virtual_id, &virtual_type); 5636 ret = pf_icmp_state_lookup(&pd2, &key, state, 5637 virtual_id, virtual_type, icmp_dir, &iidx, 0, 1); 5638 /* IPv6? try matching a multicast address */ 5639 if (ret == PF_DROP && pd2.af == AF_INET6 && 5640 icmp_dir == PF_OUT) 5641 ret = pf_icmp_state_lookup(&pd2, &key, state, 5642 virtual_id, virtual_type, icmp_dir, &iidx, 5643 1, 1); 5644 if (ret >= 0) 5645 return (ret); 5646 5647 /* translate source/destination address, if necessary */ 5648 if ((*state)->key[PF_SK_WIRE] != 5649 (*state)->key[PF_SK_STACK]) { 5650 struct pf_state_key *nk; 5651 int afto, sidx, didx; 5652 5653 if (PF_REVERSED_KEY((*state)->key, pd->af)) 5654 nk = (*state)->key[pd->sidx]; 5655 else 5656 nk = (*state)->key[pd->didx]; 5657 5658 afto = pd->af != nk->af; 5659 sidx = afto ? pd2.didx : pd2.sidx; 5660 didx = afto ? pd2.sidx : pd2.didx; 5661 iidx = afto ? !iidx : iidx; 5662 5663 if (afto) { 5664 if (nk->af != AF_INET) 5665 return (PF_DROP); 5666 if (pf_translate_icmp_af(pd, nk->af, 5667 &pd->hdr.icmp)) 5668 return (PF_DROP); 5669 m_copyback(pd->m, pd->off, 5670 sizeof(struct icmp6_hdr), 5671 &pd->hdr.icmp6, M_NOWAIT); 5672 if (pf_change_icmp_af(pd->m, ipoff2, 5673 pd, &pd2, &nk->addr[sidx], 5674 &nk->addr[didx], pd->af, nk->af)) 5675 return (PF_DROP); 5676 pd->proto = IPPROTO_ICMP; 5677 if (pf_translate_icmp_af(pd, 5678 nk->af, iih)) 5679 return (PF_DROP); 5680 if (virtual_type == 5681 htons(ICMP6_ECHO_REQUEST)) 5682 pf_patch_16(pd, &iih->icmp6_id, 5683 nk->port[iidx]); 5684 m_copyback(pd2.m, pd2.off, 5685 sizeof(struct icmp6_hdr), iih, 5686 M_NOWAIT); 5687 pd->m->m_pkthdr.ph_rtableid = 5688 nk->rdomain; 5689 pd->destchg = 1; 5690 pf_addrcpy(&pd->nsaddr, 5691 &nk->addr[pd2.sidx], nk->af); 5692 pf_addrcpy(&pd->ndaddr, 5693 &nk->addr[pd2.didx], nk->af); 5694 pd->naf = nk->af; 5695 return (PF_AFRT); 5696 } 5697 5698 if (PF_ANEQ(pd2.src, 5699 &nk->addr[pd2.sidx], pd2.af) || 5700 ((virtual_type == 5701 htons(ICMP6_ECHO_REQUEST)) && 5702 nk->port[pd2.sidx] != iih->icmp6_id)) 5703 pf_translate_icmp(pd, pd2.src, 5704 (virtual_type == 5705 htons(ICMP6_ECHO_REQUEST)) 5706 ? &iih->icmp6_id : NULL, 5707 pd->dst, &nk->addr[pd2.sidx], 5708 (virtual_type == 5709 htons(ICMP6_ECHO_REQUEST)) 5710 ? nk->port[iidx] : 0); 5711 5712 if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], 5713 pd2.af) || pd2.rdomain != nk->rdomain) 5714 pd->destchg = 1; 5715 pd->m->m_pkthdr.ph_rtableid = nk->rdomain; 5716 5717 if (PF_ANEQ(pd2.dst, 5718 &nk->addr[pd2.didx], pd2.af)) 5719 pf_translate_icmp(pd, pd2.dst, NULL, 5720 pd->src, &nk->addr[pd2.didx], 0); 5721 5722 m_copyback(pd->m, pd->off, 5723 sizeof(struct icmp6_hdr), &pd->hdr.icmp6, 5724 M_NOWAIT); 5725 m_copyback(pd2.m, ipoff2, sizeof(h2_6), &h2_6, 5726 M_NOWAIT); 5727 m_copyback(pd2.m, pd2.off, 5728 sizeof(struct icmp6_hdr), iih, M_NOWAIT); 5729 copyback = 1; 5730 } 5731 break; 5732 } 5733 #endif /* INET6 */ 5734 default: { 5735 int action; 5736 5737 key.af = pd2.af; 5738 key.proto = pd2.proto; 5739 key.rdomain = pd2.rdomain; 5740 pf_addrcpy(&key.addr[pd2.sidx], pd2.src, key.af); 5741 pf_addrcpy(&key.addr[pd2.didx], pd2.dst, key.af); 5742 key.port[0] = key.port[1] = 0; 5743 5744 action = pf_find_state(&pd2, &key, state); 5745 if (action != PF_MATCH) 5746 return (action); 5747 5748 /* translate source/destination address, if necessary */ 5749 if ((*state)->key[PF_SK_WIRE] != 5750 (*state)->key[PF_SK_STACK]) { 5751 struct pf_state_key *nk = 5752 (*state)->key[pd->didx]; 5753 5754 if (PF_ANEQ(pd2.src, 5755 &nk->addr[pd2.sidx], pd2.af)) 5756 pf_translate_icmp(pd, pd2.src, NULL, 5757 pd->dst, &nk->addr[pd2.sidx], 0); 5758 5759 if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], 5760 pd2.af) || pd2.rdomain != nk->rdomain) 5761 pd->destchg = 1; 5762 pd->m->m_pkthdr.ph_rtableid = nk->rdomain; 5763 5764 if (PF_ANEQ(pd2.dst, 5765 &nk->addr[pd2.didx], pd2.af)) 5766 pf_translate_icmp(pd, pd2.dst, NULL, 5767 pd->src, &nk->addr[pd2.didx], 0); 5768 5769 switch (pd2.af) { 5770 case AF_INET: 5771 m_copyback(pd->m, pd->off, ICMP_MINLEN, 5772 &pd->hdr.icmp, M_NOWAIT); 5773 m_copyback(pd2.m, ipoff2, sizeof(h2), 5774 &h2, M_NOWAIT); 5775 break; 5776 #ifdef INET6 5777 case AF_INET6: 5778 m_copyback(pd->m, pd->off, 5779 sizeof(struct icmp6_hdr), 5780 &pd->hdr.icmp6, M_NOWAIT); 5781 m_copyback(pd2.m, ipoff2, sizeof(h2_6), 5782 &h2_6, M_NOWAIT); 5783 break; 5784 #endif /* INET6 */ 5785 } 5786 copyback = 1; 5787 } 5788 break; 5789 } 5790 } 5791 } 5792 if (copyback) { 5793 m_copyback(pd->m, pd->off, pd->hdrlen, &pd->hdr, M_NOWAIT); 5794 } 5795 5796 return (PF_PASS); 5797 } 5798 5799 /* 5800 * ipoff and off are measured from the start of the mbuf chain. 5801 * h must be at "ipoff" on the mbuf chain. 5802 */ 5803 void * 5804 pf_pull_hdr(struct mbuf *m, int off, void *p, int len, 5805 u_short *actionp, u_short *reasonp, sa_family_t af) 5806 { 5807 int iplen = 0; 5808 5809 switch (af) { 5810 case AF_INET: { 5811 struct ip *h = mtod(m, struct ip *); 5812 u_int16_t fragoff = (ntohs(h->ip_off) & IP_OFFMASK) << 3; 5813 5814 if (fragoff) { 5815 if (fragoff >= len) 5816 ACTION_SET(actionp, PF_PASS); 5817 else { 5818 ACTION_SET(actionp, PF_DROP); 5819 REASON_SET(reasonp, PFRES_FRAG); 5820 } 5821 return (NULL); 5822 } 5823 iplen = ntohs(h->ip_len); 5824 break; 5825 } 5826 #ifdef INET6 5827 case AF_INET6: { 5828 struct ip6_hdr *h = mtod(m, struct ip6_hdr *); 5829 5830 iplen = ntohs(h->ip6_plen) + sizeof(struct ip6_hdr); 5831 break; 5832 } 5833 #endif /* INET6 */ 5834 } 5835 if (m->m_pkthdr.len < off + len || iplen < off + len) { 5836 ACTION_SET(actionp, PF_DROP); 5837 REASON_SET(reasonp, PFRES_SHORT); 5838 return (NULL); 5839 } 5840 m_copydata(m, off, len, p); 5841 return (p); 5842 } 5843 5844 int 5845 pf_routable(struct pf_addr *addr, sa_family_t af, struct pfi_kif *kif, 5846 int rtableid) 5847 { 5848 struct sockaddr_storage ss; 5849 struct sockaddr_in *dst; 5850 int ret = 1; 5851 int check_mpath; 5852 #ifdef INET6 5853 struct sockaddr_in6 *dst6; 5854 #endif /* INET6 */ 5855 struct rtentry *rt = NULL; 5856 5857 check_mpath = 0; 5858 memset(&ss, 0, sizeof(ss)); 5859 switch (af) { 5860 case AF_INET: 5861 dst = (struct sockaddr_in *)&ss; 5862 dst->sin_family = AF_INET; 5863 dst->sin_len = sizeof(*dst); 5864 dst->sin_addr = addr->v4; 5865 if (ipmultipath) 5866 check_mpath = 1; 5867 break; 5868 #ifdef INET6 5869 case AF_INET6: 5870 /* 5871 * Skip check for addresses with embedded interface scope, 5872 * as they would always match anyway. 5873 */ 5874 if (IN6_IS_SCOPE_EMBED(&addr->v6)) 5875 goto out; 5876 dst6 = (struct sockaddr_in6 *)&ss; 5877 dst6->sin6_family = AF_INET6; 5878 dst6->sin6_len = sizeof(*dst6); 5879 dst6->sin6_addr = addr->v6; 5880 if (ip6_multipath) 5881 check_mpath = 1; 5882 break; 5883 #endif /* INET6 */ 5884 } 5885 5886 /* Skip checks for ipsec interfaces */ 5887 if (kif != NULL && kif->pfik_ifp->if_type == IFT_ENC) 5888 goto out; 5889 5890 rt = rtalloc(sstosa(&ss), 0, rtableid); 5891 if (rt != NULL) { 5892 /* No interface given, this is a no-route check */ 5893 if (kif == NULL) 5894 goto out; 5895 5896 if (kif->pfik_ifp == NULL) { 5897 ret = 0; 5898 goto out; 5899 } 5900 5901 /* Perform uRPF check if passed input interface */ 5902 ret = 0; 5903 do { 5904 if (rt->rt_ifidx == kif->pfik_ifp->if_index) { 5905 ret = 1; 5906 #if NCARP > 0 5907 } else { 5908 struct ifnet *ifp; 5909 5910 ifp = if_get(rt->rt_ifidx); 5911 if (ifp != NULL && ifp->if_type == IFT_CARP && 5912 ifp->if_carpdevidx == 5913 kif->pfik_ifp->if_index) 5914 ret = 1; 5915 if_put(ifp); 5916 #endif /* NCARP */ 5917 } 5918 5919 rt = rtable_iterate(rt); 5920 } while (check_mpath == 1 && rt != NULL && ret == 0); 5921 } else 5922 ret = 0; 5923 out: 5924 rtfree(rt); 5925 return (ret); 5926 } 5927 5928 int 5929 pf_rtlabel_match(struct pf_addr *addr, sa_family_t af, struct pf_addr_wrap *aw, 5930 int rtableid) 5931 { 5932 struct sockaddr_storage ss; 5933 struct sockaddr_in *dst; 5934 #ifdef INET6 5935 struct sockaddr_in6 *dst6; 5936 #endif /* INET6 */ 5937 struct rtentry *rt; 5938 int ret = 0; 5939 5940 memset(&ss, 0, sizeof(ss)); 5941 switch (af) { 5942 case AF_INET: 5943 dst = (struct sockaddr_in *)&ss; 5944 dst->sin_family = AF_INET; 5945 dst->sin_len = sizeof(*dst); 5946 dst->sin_addr = addr->v4; 5947 break; 5948 #ifdef INET6 5949 case AF_INET6: 5950 dst6 = (struct sockaddr_in6 *)&ss; 5951 dst6->sin6_family = AF_INET6; 5952 dst6->sin6_len = sizeof(*dst6); 5953 dst6->sin6_addr = addr->v6; 5954 break; 5955 #endif /* INET6 */ 5956 } 5957 5958 rt = rtalloc(sstosa(&ss), RT_RESOLVE, rtableid); 5959 if (rt != NULL) { 5960 if (rt->rt_labelid == aw->v.rtlabel) 5961 ret = 1; 5962 rtfree(rt); 5963 } 5964 5965 return (ret); 5966 } 5967 5968 /* pf_route() may change pd->m, adjust local copies after calling */ 5969 void 5970 pf_route(struct pf_pdesc *pd, struct pf_state *s) 5971 { 5972 struct mbuf *m0; 5973 struct mbuf_list fml; 5974 struct sockaddr_in *dst, sin; 5975 struct rtentry *rt = NULL; 5976 struct ip *ip; 5977 struct ifnet *ifp = NULL; 5978 int error = 0; 5979 unsigned int rtableid; 5980 5981 if (pd->m->m_pkthdr.pf.routed++ > 3) { 5982 m_freem(pd->m); 5983 pd->m = NULL; 5984 return; 5985 } 5986 5987 if (s->rt == PF_DUPTO) { 5988 if ((m0 = m_dup_pkt(pd->m, max_linkhdr, M_NOWAIT)) == NULL) 5989 return; 5990 } else { 5991 if ((s->rt == PF_REPLYTO) == (s->direction == pd->dir)) 5992 return; 5993 m0 = pd->m; 5994 pd->m = NULL; 5995 } 5996 5997 if (m0->m_len < sizeof(struct ip)) { 5998 DPFPRINTF(LOG_ERR, 5999 "%s: m0->m_len < sizeof(struct ip)", __func__); 6000 goto bad; 6001 } 6002 6003 ip = mtod(m0, struct ip *); 6004 6005 if (pd->dir == PF_IN) { 6006 if (ip->ip_ttl <= IPTTLDEC) { 6007 if (s->rt != PF_DUPTO) { 6008 pf_send_icmp(m0, ICMP_TIMXCEED, 6009 ICMP_TIMXCEED_INTRANS, 0, 6010 pd->af, s->rule.ptr, pd->rdomain); 6011 } 6012 goto bad; 6013 } 6014 ip->ip_ttl -= IPTTLDEC; 6015 } 6016 6017 memset(&sin, 0, sizeof(sin)); 6018 dst = &sin; 6019 dst->sin_family = AF_INET; 6020 dst->sin_len = sizeof(*dst); 6021 dst->sin_addr = s->rt_addr.v4; 6022 rtableid = m0->m_pkthdr.ph_rtableid; 6023 6024 rt = rtalloc_mpath(sintosa(dst), &ip->ip_src.s_addr, rtableid); 6025 if (!rtisvalid(rt)) { 6026 if (s->rt != PF_DUPTO) { 6027 pf_send_icmp(m0, ICMP_UNREACH, ICMP_UNREACH_HOST, 6028 0, pd->af, s->rule.ptr, pd->rdomain); 6029 } 6030 ipstat_inc(ips_noroute); 6031 goto bad; 6032 } 6033 6034 ifp = if_get(rt->rt_ifidx); 6035 if (ifp == NULL) 6036 goto bad; 6037 6038 /* A locally generated packet may have invalid source address. */ 6039 if ((ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET && 6040 (ifp->if_flags & IFF_LOOPBACK) == 0) 6041 ip->ip_src = ifatoia(rt->rt_ifa)->ia_addr.sin_addr; 6042 6043 if (s->rt != PF_DUPTO && pd->dir == PF_IN) { 6044 if (pf_test(AF_INET, PF_OUT, ifp, &m0) != PF_PASS) 6045 goto bad; 6046 else if (m0 == NULL) 6047 goto done; 6048 if (m0->m_len < sizeof(struct ip)) { 6049 DPFPRINTF(LOG_ERR, 6050 "%s: m0->m_len < sizeof(struct ip)", __func__); 6051 goto bad; 6052 } 6053 ip = mtod(m0, struct ip *); 6054 } 6055 6056 in_proto_cksum_out(m0, ifp); 6057 6058 if (ntohs(ip->ip_len) <= ifp->if_mtu) { 6059 ip->ip_sum = 0; 6060 if (ifp->if_capabilities & IFCAP_CSUM_IPv4) 6061 m0->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; 6062 else { 6063 ipstat_inc(ips_outswcsum); 6064 ip->ip_sum = in_cksum(m0, ip->ip_hl << 2); 6065 } 6066 error = ifp->if_output(ifp, m0, sintosa(dst), rt); 6067 goto done; 6068 } 6069 6070 /* 6071 * Too large for interface; fragment if possible. 6072 * Must be able to put at least 8 bytes per fragment. 6073 */ 6074 if (ip->ip_off & htons(IP_DF)) { 6075 ipstat_inc(ips_cantfrag); 6076 if (s->rt != PF_DUPTO) 6077 pf_send_icmp(m0, ICMP_UNREACH, ICMP_UNREACH_NEEDFRAG, 6078 ifp->if_mtu, pd->af, s->rule.ptr, pd->rdomain); 6079 goto bad; 6080 } 6081 6082 error = ip_fragment(m0, &fml, ifp, ifp->if_mtu); 6083 if (error) 6084 goto done; 6085 6086 while ((m0 = ml_dequeue(&fml)) != NULL) { 6087 error = ifp->if_output(ifp, m0, sintosa(dst), rt); 6088 if (error) 6089 break; 6090 } 6091 if (error) 6092 ml_purge(&fml); 6093 else 6094 ipstat_inc(ips_fragmented); 6095 6096 done: 6097 if_put(ifp); 6098 rtfree(rt); 6099 return; 6100 6101 bad: 6102 m_freem(m0); 6103 goto done; 6104 } 6105 6106 #ifdef INET6 6107 /* pf_route6() may change pd->m, adjust local copies after calling */ 6108 void 6109 pf_route6(struct pf_pdesc *pd, struct pf_state *s) 6110 { 6111 struct mbuf *m0; 6112 struct sockaddr_in6 *dst, sin6; 6113 struct rtentry *rt = NULL; 6114 struct ip6_hdr *ip6; 6115 struct ifnet *ifp = NULL; 6116 struct m_tag *mtag; 6117 unsigned int rtableid; 6118 6119 if (pd->m->m_pkthdr.pf.routed++ > 3) { 6120 m_freem(pd->m); 6121 pd->m = NULL; 6122 return; 6123 } 6124 6125 if (s->rt == PF_DUPTO) { 6126 if ((m0 = m_dup_pkt(pd->m, max_linkhdr, M_NOWAIT)) == NULL) 6127 return; 6128 } else { 6129 if ((s->rt == PF_REPLYTO) == (s->direction == pd->dir)) 6130 return; 6131 m0 = pd->m; 6132 pd->m = NULL; 6133 } 6134 6135 if (m0->m_len < sizeof(struct ip6_hdr)) { 6136 DPFPRINTF(LOG_ERR, 6137 "%s: m0->m_len < sizeof(struct ip6_hdr)", __func__); 6138 goto bad; 6139 } 6140 ip6 = mtod(m0, struct ip6_hdr *); 6141 6142 if (pd->dir == PF_IN) { 6143 if (ip6->ip6_hlim <= IPV6_HLIMDEC) { 6144 if (s->rt != PF_DUPTO) { 6145 pf_send_icmp(m0, ICMP6_TIME_EXCEEDED, 6146 ICMP6_TIME_EXCEED_TRANSIT, 0, 6147 pd->af, s->rule.ptr, pd->rdomain); 6148 } 6149 goto bad; 6150 } 6151 ip6->ip6_hlim -= IPV6_HLIMDEC; 6152 } 6153 6154 memset(&sin6, 0, sizeof(sin6)); 6155 dst = &sin6; 6156 dst->sin6_family = AF_INET6; 6157 dst->sin6_len = sizeof(*dst); 6158 dst->sin6_addr = s->rt_addr.v6; 6159 rtableid = m0->m_pkthdr.ph_rtableid; 6160 6161 rt = rtalloc_mpath(sin6tosa(dst), &ip6->ip6_src.s6_addr32[0], 6162 rtableid); 6163 if (!rtisvalid(rt)) { 6164 if (s->rt != PF_DUPTO) { 6165 pf_send_icmp(m0, ICMP6_DST_UNREACH, 6166 ICMP6_DST_UNREACH_NOROUTE, 0, 6167 pd->af, s->rule.ptr, pd->rdomain); 6168 } 6169 ip6stat_inc(ip6s_noroute); 6170 goto bad; 6171 } 6172 6173 ifp = if_get(rt->rt_ifidx); 6174 if (ifp == NULL) 6175 goto bad; 6176 6177 /* A locally generated packet may have invalid source address. */ 6178 if (IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && 6179 (ifp->if_flags & IFF_LOOPBACK) == 0) 6180 ip6->ip6_src = ifatoia6(rt->rt_ifa)->ia_addr.sin6_addr; 6181 6182 if (s->rt != PF_DUPTO && pd->dir == PF_IN) { 6183 if (pf_test(AF_INET6, PF_OUT, ifp, &m0) != PF_PASS) 6184 goto bad; 6185 else if (m0 == NULL) 6186 goto done; 6187 if (m0->m_len < sizeof(struct ip6_hdr)) { 6188 DPFPRINTF(LOG_ERR, 6189 "%s: m0->m_len < sizeof(struct ip6_hdr)", __func__); 6190 goto bad; 6191 } 6192 } 6193 6194 in6_proto_cksum_out(m0, ifp); 6195 6196 /* 6197 * If packet has been reassembled by PF earlier, we have to 6198 * use pf_refragment6() here to turn it back to fragments. 6199 */ 6200 if ((mtag = m_tag_find(m0, PACKET_TAG_PF_REASSEMBLED, NULL))) { 6201 (void) pf_refragment6(&m0, mtag, dst, ifp, rt); 6202 } else if ((u_long)m0->m_pkthdr.len <= ifp->if_mtu) { 6203 ifp->if_output(ifp, m0, sin6tosa(dst), rt); 6204 } else { 6205 ip6stat_inc(ip6s_cantfrag); 6206 if (s->rt != PF_DUPTO) 6207 pf_send_icmp(m0, ICMP6_PACKET_TOO_BIG, 0, 6208 ifp->if_mtu, pd->af, s->rule.ptr, pd->rdomain); 6209 goto bad; 6210 } 6211 6212 done: 6213 if_put(ifp); 6214 rtfree(rt); 6215 return; 6216 6217 bad: 6218 m_freem(m0); 6219 goto done; 6220 } 6221 #endif /* INET6 */ 6222 6223 /* 6224 * check TCP checksum and set mbuf flag 6225 * off is the offset where the protocol header starts 6226 * len is the total length of protocol header plus payload 6227 * returns 0 when the checksum is valid, otherwise returns 1. 6228 * if the _OUT flag is set the checksum isn't done yet, consider these ok 6229 */ 6230 int 6231 pf_check_tcp_cksum(struct mbuf *m, int off, int len, sa_family_t af) 6232 { 6233 u_int16_t sum; 6234 6235 if (m->m_pkthdr.csum_flags & 6236 (M_TCP_CSUM_IN_OK | M_TCP_CSUM_OUT)) { 6237 return (0); 6238 } 6239 if (m->m_pkthdr.csum_flags & M_TCP_CSUM_IN_BAD || 6240 off < sizeof(struct ip) || 6241 m->m_pkthdr.len < off + len) { 6242 return (1); 6243 } 6244 6245 /* need to do it in software */ 6246 tcpstat_inc(tcps_inswcsum); 6247 6248 switch (af) { 6249 case AF_INET: 6250 if (m->m_len < sizeof(struct ip)) 6251 return (1); 6252 6253 sum = in4_cksum(m, IPPROTO_TCP, off, len); 6254 break; 6255 #ifdef INET6 6256 case AF_INET6: 6257 if (m->m_len < sizeof(struct ip6_hdr)) 6258 return (1); 6259 6260 sum = in6_cksum(m, IPPROTO_TCP, off, len); 6261 break; 6262 #endif /* INET6 */ 6263 default: 6264 unhandled_af(af); 6265 } 6266 if (sum) { 6267 tcpstat_inc(tcps_rcvbadsum); 6268 m->m_pkthdr.csum_flags |= M_TCP_CSUM_IN_BAD; 6269 return (1); 6270 } 6271 6272 m->m_pkthdr.csum_flags |= M_TCP_CSUM_IN_OK; 6273 return (0); 6274 } 6275 6276 struct pf_divert * 6277 pf_find_divert(struct mbuf *m) 6278 { 6279 struct m_tag *mtag; 6280 6281 if ((mtag = m_tag_find(m, PACKET_TAG_PF_DIVERT, NULL)) == NULL) 6282 return (NULL); 6283 6284 return ((struct pf_divert *)(mtag + 1)); 6285 } 6286 6287 struct pf_divert * 6288 pf_get_divert(struct mbuf *m) 6289 { 6290 struct m_tag *mtag; 6291 6292 if ((mtag = m_tag_find(m, PACKET_TAG_PF_DIVERT, NULL)) == NULL) { 6293 mtag = m_tag_get(PACKET_TAG_PF_DIVERT, sizeof(struct pf_divert), 6294 M_NOWAIT); 6295 if (mtag == NULL) 6296 return (NULL); 6297 memset(mtag + 1, 0, sizeof(struct pf_divert)); 6298 m_tag_prepend(m, mtag); 6299 } 6300 6301 return ((struct pf_divert *)(mtag + 1)); 6302 } 6303 6304 int 6305 pf_walk_header(struct pf_pdesc *pd, struct ip *h, u_short *reason) 6306 { 6307 struct ip6_ext ext; 6308 u_int32_t hlen, end; 6309 int hdr_cnt; 6310 6311 hlen = h->ip_hl << 2; 6312 if (hlen < sizeof(struct ip) || hlen > ntohs(h->ip_len)) { 6313 REASON_SET(reason, PFRES_SHORT); 6314 return (PF_DROP); 6315 } 6316 if (hlen != sizeof(struct ip)) 6317 pd->badopts++; 6318 end = pd->off + ntohs(h->ip_len); 6319 pd->off += hlen; 6320 pd->proto = h->ip_p; 6321 /* stop walking over non initial fragments */ 6322 if ((h->ip_off & htons(IP_OFFMASK)) != 0) 6323 return (PF_PASS); 6324 6325 for (hdr_cnt = 0; hdr_cnt < pf_hdr_limit; hdr_cnt++) { 6326 switch (pd->proto) { 6327 case IPPROTO_AH: 6328 /* fragments may be short */ 6329 if ((h->ip_off & htons(IP_MF | IP_OFFMASK)) != 0 && 6330 end < pd->off + sizeof(ext)) 6331 return (PF_PASS); 6332 if (!pf_pull_hdr(pd->m, pd->off, &ext, sizeof(ext), 6333 NULL, reason, AF_INET)) { 6334 DPFPRINTF(LOG_NOTICE, "IP short exthdr"); 6335 return (PF_DROP); 6336 } 6337 pd->off += (ext.ip6e_len + 2) * 4; 6338 pd->proto = ext.ip6e_nxt; 6339 break; 6340 default: 6341 return (PF_PASS); 6342 } 6343 } 6344 DPFPRINTF(LOG_NOTICE, "IPv4 nested authentication header limit"); 6345 REASON_SET(reason, PFRES_IPOPTIONS); 6346 return (PF_DROP); 6347 } 6348 6349 #ifdef INET6 6350 int 6351 pf_walk_option6(struct pf_pdesc *pd, struct ip6_hdr *h, int off, int end, 6352 u_short *reason) 6353 { 6354 struct ip6_opt opt; 6355 struct ip6_opt_jumbo jumbo; 6356 6357 while (off < end) { 6358 if (!pf_pull_hdr(pd->m, off, &opt.ip6o_type, 6359 sizeof(opt.ip6o_type), NULL, reason, AF_INET6)) { 6360 DPFPRINTF(LOG_NOTICE, "IPv6 short opt type"); 6361 return (PF_DROP); 6362 } 6363 if (opt.ip6o_type == IP6OPT_PAD1) { 6364 off++; 6365 continue; 6366 } 6367 if (!pf_pull_hdr(pd->m, off, &opt, sizeof(opt), 6368 NULL, reason, AF_INET6)) { 6369 DPFPRINTF(LOG_NOTICE, "IPv6 short opt"); 6370 return (PF_DROP); 6371 } 6372 if (off + sizeof(opt) + opt.ip6o_len > end) { 6373 DPFPRINTF(LOG_NOTICE, "IPv6 long opt"); 6374 REASON_SET(reason, PFRES_IPOPTIONS); 6375 return (PF_DROP); 6376 } 6377 switch (opt.ip6o_type) { 6378 case IP6OPT_JUMBO: 6379 if (pd->jumbolen != 0) { 6380 DPFPRINTF(LOG_NOTICE, "IPv6 multiple jumbo"); 6381 REASON_SET(reason, PFRES_IPOPTIONS); 6382 return (PF_DROP); 6383 } 6384 if (ntohs(h->ip6_plen) != 0) { 6385 DPFPRINTF(LOG_NOTICE, "IPv6 bad jumbo plen"); 6386 REASON_SET(reason, PFRES_IPOPTIONS); 6387 return (PF_DROP); 6388 } 6389 if (!pf_pull_hdr(pd->m, off, &jumbo, sizeof(jumbo), 6390 NULL, reason, AF_INET6)) { 6391 DPFPRINTF(LOG_NOTICE, "IPv6 short jumbo"); 6392 return (PF_DROP); 6393 } 6394 memcpy(&pd->jumbolen, jumbo.ip6oj_jumbo_len, 6395 sizeof(pd->jumbolen)); 6396 pd->jumbolen = ntohl(pd->jumbolen); 6397 if (pd->jumbolen < IPV6_MAXPACKET) { 6398 DPFPRINTF(LOG_NOTICE, "IPv6 short jumbolen"); 6399 REASON_SET(reason, PFRES_IPOPTIONS); 6400 return (PF_DROP); 6401 } 6402 break; 6403 default: 6404 break; 6405 } 6406 off += sizeof(opt) + opt.ip6o_len; 6407 } 6408 6409 return (PF_PASS); 6410 } 6411 6412 int 6413 pf_walk_header6(struct pf_pdesc *pd, struct ip6_hdr *h, u_short *reason) 6414 { 6415 struct ip6_frag frag; 6416 struct ip6_ext ext; 6417 struct ip6_rthdr rthdr; 6418 u_int32_t end; 6419 int hdr_cnt, fraghdr_cnt = 0, rthdr_cnt = 0; 6420 6421 pd->off += sizeof(struct ip6_hdr); 6422 end = pd->off + ntohs(h->ip6_plen); 6423 pd->fragoff = pd->extoff = pd->jumbolen = 0; 6424 pd->proto = h->ip6_nxt; 6425 6426 for (hdr_cnt = 0; hdr_cnt < pf_hdr_limit; hdr_cnt++) { 6427 switch (pd->proto) { 6428 case IPPROTO_ROUTING: 6429 case IPPROTO_HOPOPTS: 6430 case IPPROTO_DSTOPTS: 6431 pd->badopts++; 6432 break; 6433 } 6434 switch (pd->proto) { 6435 case IPPROTO_FRAGMENT: 6436 if (fraghdr_cnt++) { 6437 DPFPRINTF(LOG_NOTICE, "IPv6 multiple fragment"); 6438 REASON_SET(reason, PFRES_FRAG); 6439 return (PF_DROP); 6440 } 6441 /* jumbo payload packets cannot be fragmented */ 6442 if (pd->jumbolen != 0) { 6443 DPFPRINTF(LOG_NOTICE, "IPv6 fragmented jumbo"); 6444 REASON_SET(reason, PFRES_FRAG); 6445 return (PF_DROP); 6446 } 6447 if (!pf_pull_hdr(pd->m, pd->off, &frag, sizeof(frag), 6448 NULL, reason, AF_INET6)) { 6449 DPFPRINTF(LOG_NOTICE, "IPv6 short fragment"); 6450 return (PF_DROP); 6451 } 6452 /* stop walking over non initial fragments */ 6453 if (ntohs((frag.ip6f_offlg & IP6F_OFF_MASK)) != 0) { 6454 pd->fragoff = pd->off; 6455 return (PF_PASS); 6456 } 6457 /* RFC6946: reassemble only non atomic fragments */ 6458 if (frag.ip6f_offlg & IP6F_MORE_FRAG) 6459 pd->fragoff = pd->off; 6460 pd->off += sizeof(frag); 6461 pd->proto = frag.ip6f_nxt; 6462 break; 6463 case IPPROTO_ROUTING: 6464 if (rthdr_cnt++) { 6465 DPFPRINTF(LOG_NOTICE, "IPv6 multiple rthdr"); 6466 REASON_SET(reason, PFRES_IPOPTIONS); 6467 return (PF_DROP); 6468 } 6469 /* fragments may be short */ 6470 if (pd->fragoff != 0 && end < pd->off + sizeof(rthdr)) { 6471 pd->off = pd->fragoff; 6472 pd->proto = IPPROTO_FRAGMENT; 6473 return (PF_PASS); 6474 } 6475 if (!pf_pull_hdr(pd->m, pd->off, &rthdr, sizeof(rthdr), 6476 NULL, reason, AF_INET6)) { 6477 DPFPRINTF(LOG_NOTICE, "IPv6 short rthdr"); 6478 return (PF_DROP); 6479 } 6480 if (rthdr.ip6r_type == IPV6_RTHDR_TYPE_0) { 6481 DPFPRINTF(LOG_NOTICE, "IPv6 rthdr0"); 6482 REASON_SET(reason, PFRES_IPOPTIONS); 6483 return (PF_DROP); 6484 } 6485 /* FALLTHROUGH */ 6486 case IPPROTO_HOPOPTS: 6487 /* RFC2460 4.1: Hop-by-Hop only after IPv6 header */ 6488 if (pd->proto == IPPROTO_HOPOPTS && hdr_cnt > 0) { 6489 DPFPRINTF(LOG_NOTICE, "IPv6 hopopts not first"); 6490 REASON_SET(reason, PFRES_IPOPTIONS); 6491 return (PF_DROP); 6492 } 6493 /* FALLTHROUGH */ 6494 case IPPROTO_AH: 6495 case IPPROTO_DSTOPTS: 6496 /* fragments may be short */ 6497 if (pd->fragoff != 0 && end < pd->off + sizeof(ext)) { 6498 pd->off = pd->fragoff; 6499 pd->proto = IPPROTO_FRAGMENT; 6500 return (PF_PASS); 6501 } 6502 if (!pf_pull_hdr(pd->m, pd->off, &ext, sizeof(ext), 6503 NULL, reason, AF_INET6)) { 6504 DPFPRINTF(LOG_NOTICE, "IPv6 short exthdr"); 6505 return (PF_DROP); 6506 } 6507 /* reassembly needs the ext header before the frag */ 6508 if (pd->fragoff == 0) 6509 pd->extoff = pd->off; 6510 if (pd->proto == IPPROTO_HOPOPTS && pd->fragoff == 0) { 6511 if (pf_walk_option6(pd, h, 6512 pd->off + sizeof(ext), 6513 pd->off + (ext.ip6e_len + 1) * 8, reason) 6514 != PF_PASS) 6515 return (PF_DROP); 6516 if (ntohs(h->ip6_plen) == 0 && 6517 pd->jumbolen != 0) { 6518 DPFPRINTF(LOG_NOTICE, 6519 "IPv6 missing jumbo"); 6520 REASON_SET(reason, PFRES_IPOPTIONS); 6521 return (PF_DROP); 6522 } 6523 } 6524 if (pd->proto == IPPROTO_AH) 6525 pd->off += (ext.ip6e_len + 2) * 4; 6526 else 6527 pd->off += (ext.ip6e_len + 1) * 8; 6528 pd->proto = ext.ip6e_nxt; 6529 break; 6530 case IPPROTO_TCP: 6531 case IPPROTO_UDP: 6532 case IPPROTO_ICMPV6: 6533 /* fragments may be short, ignore inner header then */ 6534 if (pd->fragoff != 0 && end < pd->off + 6535 (pd->proto == IPPROTO_TCP ? sizeof(struct tcphdr) : 6536 pd->proto == IPPROTO_UDP ? sizeof(struct udphdr) : 6537 sizeof(struct icmp6_hdr))) { 6538 pd->off = pd->fragoff; 6539 pd->proto = IPPROTO_FRAGMENT; 6540 } 6541 /* FALLTHROUGH */ 6542 default: 6543 return (PF_PASS); 6544 } 6545 } 6546 DPFPRINTF(LOG_NOTICE, "IPv6 nested extension header limit"); 6547 REASON_SET(reason, PFRES_IPOPTIONS); 6548 return (PF_DROP); 6549 } 6550 #endif /* INET6 */ 6551 6552 int 6553 pf_setup_pdesc(struct pf_pdesc *pd, sa_family_t af, int dir, 6554 struct pfi_kif *kif, struct mbuf *m, u_short *reason) 6555 { 6556 memset(pd, 0, sizeof(*pd)); 6557 pd->dir = dir; 6558 pd->kif = kif; /* kif is NULL when called by pflog */ 6559 pd->m = m; 6560 pd->sidx = (dir == PF_IN) ? 0 : 1; 6561 pd->didx = (dir == PF_IN) ? 1 : 0; 6562 pd->af = pd->naf = af; 6563 pd->rdomain = rtable_l2(pd->m->m_pkthdr.ph_rtableid); 6564 6565 switch (pd->af) { 6566 case AF_INET: { 6567 struct ip *h; 6568 6569 /* Check for illegal packets */ 6570 if (pd->m->m_pkthdr.len < (int)sizeof(struct ip)) { 6571 REASON_SET(reason, PFRES_SHORT); 6572 return (PF_DROP); 6573 } 6574 6575 h = mtod(pd->m, struct ip *); 6576 if (pd->m->m_pkthdr.len < ntohs(h->ip_len)) { 6577 REASON_SET(reason, PFRES_SHORT); 6578 return (PF_DROP); 6579 } 6580 6581 if (pf_walk_header(pd, h, reason) != PF_PASS) 6582 return (PF_DROP); 6583 6584 pd->src = (struct pf_addr *)&h->ip_src; 6585 pd->dst = (struct pf_addr *)&h->ip_dst; 6586 pd->tot_len = ntohs(h->ip_len); 6587 pd->tos = h->ip_tos & ~IPTOS_ECN_MASK; 6588 pd->ttl = h->ip_ttl; 6589 pd->virtual_proto = (h->ip_off & htons(IP_MF | IP_OFFMASK)) ? 6590 PF_VPROTO_FRAGMENT : pd->proto; 6591 6592 break; 6593 } 6594 #ifdef INET6 6595 case AF_INET6: { 6596 struct ip6_hdr *h; 6597 6598 /* Check for illegal packets */ 6599 if (pd->m->m_pkthdr.len < (int)sizeof(struct ip6_hdr)) { 6600 REASON_SET(reason, PFRES_SHORT); 6601 return (PF_DROP); 6602 } 6603 6604 h = mtod(pd->m, struct ip6_hdr *); 6605 if (pd->m->m_pkthdr.len < 6606 sizeof(struct ip6_hdr) + ntohs(h->ip6_plen)) { 6607 REASON_SET(reason, PFRES_SHORT); 6608 return (PF_DROP); 6609 } 6610 6611 if (pf_walk_header6(pd, h, reason) != PF_PASS) 6612 return (PF_DROP); 6613 6614 #if 1 6615 /* 6616 * we do not support jumbogram yet. if we keep going, zero 6617 * ip6_plen will do something bad, so drop the packet for now. 6618 */ 6619 if (pd->jumbolen != 0) { 6620 REASON_SET(reason, PFRES_NORM); 6621 return (PF_DROP); 6622 } 6623 #endif /* 1 */ 6624 6625 pd->src = (struct pf_addr *)&h->ip6_src; 6626 pd->dst = (struct pf_addr *)&h->ip6_dst; 6627 pd->tot_len = ntohs(h->ip6_plen) + sizeof(struct ip6_hdr); 6628 pd->tos = (ntohl(h->ip6_flow) & 0x0fc00000) >> 20; 6629 pd->ttl = h->ip6_hlim; 6630 pd->virtual_proto = (pd->fragoff != 0) ? 6631 PF_VPROTO_FRAGMENT : pd->proto; 6632 6633 break; 6634 } 6635 #endif /* INET6 */ 6636 default: 6637 panic("pf_setup_pdesc called with illegal af %u", pd->af); 6638 6639 } 6640 6641 pf_addrcpy(&pd->nsaddr, pd->src, pd->af); 6642 pf_addrcpy(&pd->ndaddr, pd->dst, pd->af); 6643 6644 switch (pd->virtual_proto) { 6645 case IPPROTO_TCP: { 6646 struct tcphdr *th = &pd->hdr.tcp; 6647 6648 if (!pf_pull_hdr(pd->m, pd->off, th, sizeof(*th), 6649 NULL, reason, pd->af)) 6650 return (PF_DROP); 6651 pd->hdrlen = sizeof(*th); 6652 if (pd->off + (th->th_off << 2) > pd->tot_len || 6653 (th->th_off << 2) < sizeof(struct tcphdr)) { 6654 REASON_SET(reason, PFRES_SHORT); 6655 return (PF_DROP); 6656 } 6657 pd->p_len = pd->tot_len - pd->off - (th->th_off << 2); 6658 pd->sport = &th->th_sport; 6659 pd->dport = &th->th_dport; 6660 pd->pcksum = &th->th_sum; 6661 break; 6662 } 6663 case IPPROTO_UDP: { 6664 struct udphdr *uh = &pd->hdr.udp; 6665 6666 if (!pf_pull_hdr(pd->m, pd->off, uh, sizeof(*uh), 6667 NULL, reason, pd->af)) 6668 return (PF_DROP); 6669 pd->hdrlen = sizeof(*uh); 6670 if (uh->uh_dport == 0 || 6671 pd->off + ntohs(uh->uh_ulen) > pd->tot_len || 6672 ntohs(uh->uh_ulen) < sizeof(struct udphdr)) { 6673 REASON_SET(reason, PFRES_SHORT); 6674 return (PF_DROP); 6675 } 6676 pd->sport = &uh->uh_sport; 6677 pd->dport = &uh->uh_dport; 6678 pd->pcksum = &uh->uh_sum; 6679 break; 6680 } 6681 case IPPROTO_ICMP: { 6682 if (!pf_pull_hdr(pd->m, pd->off, &pd->hdr.icmp, ICMP_MINLEN, 6683 NULL, reason, pd->af)) 6684 return (PF_DROP); 6685 pd->hdrlen = ICMP_MINLEN; 6686 if (pd->off + pd->hdrlen > pd->tot_len) { 6687 REASON_SET(reason, PFRES_SHORT); 6688 return (PF_DROP); 6689 } 6690 pd->pcksum = &pd->hdr.icmp.icmp_cksum; 6691 break; 6692 } 6693 #ifdef INET6 6694 case IPPROTO_ICMPV6: { 6695 size_t icmp_hlen = sizeof(struct icmp6_hdr); 6696 6697 if (!pf_pull_hdr(pd->m, pd->off, &pd->hdr.icmp6, icmp_hlen, 6698 NULL, reason, pd->af)) 6699 return (PF_DROP); 6700 /* ICMP headers we look further into to match state */ 6701 switch (pd->hdr.icmp6.icmp6_type) { 6702 case MLD_LISTENER_QUERY: 6703 case MLD_LISTENER_REPORT: 6704 icmp_hlen = sizeof(struct mld_hdr); 6705 break; 6706 case ND_NEIGHBOR_SOLICIT: 6707 case ND_NEIGHBOR_ADVERT: 6708 icmp_hlen = sizeof(struct nd_neighbor_solicit); 6709 /* FALLTHROUGH */ 6710 case ND_ROUTER_SOLICIT: 6711 case ND_ROUTER_ADVERT: 6712 case ND_REDIRECT: 6713 if (pd->ttl != 255) { 6714 REASON_SET(reason, PFRES_NORM); 6715 return (PF_DROP); 6716 } 6717 break; 6718 } 6719 if (icmp_hlen > sizeof(struct icmp6_hdr) && 6720 !pf_pull_hdr(pd->m, pd->off, &pd->hdr.icmp6, icmp_hlen, 6721 NULL, reason, pd->af)) 6722 return (PF_DROP); 6723 pd->hdrlen = icmp_hlen; 6724 if (pd->off + pd->hdrlen > pd->tot_len) { 6725 REASON_SET(reason, PFRES_SHORT); 6726 return (PF_DROP); 6727 } 6728 pd->pcksum = &pd->hdr.icmp6.icmp6_cksum; 6729 break; 6730 } 6731 #endif /* INET6 */ 6732 } 6733 6734 if (pd->sport) 6735 pd->osport = pd->nsport = *pd->sport; 6736 if (pd->dport) 6737 pd->odport = pd->ndport = *pd->dport; 6738 6739 return (PF_PASS); 6740 } 6741 6742 void 6743 pf_counters_inc(int action, struct pf_pdesc *pd, struct pf_state *s, 6744 struct pf_rule *r, struct pf_rule *a) 6745 { 6746 int dirndx; 6747 pd->kif->pfik_bytes[pd->af == AF_INET6][pd->dir == PF_OUT] 6748 [action != PF_PASS] += pd->tot_len; 6749 pd->kif->pfik_packets[pd->af == AF_INET6][pd->dir == PF_OUT] 6750 [action != PF_PASS]++; 6751 6752 if (action == PF_PASS || action == PF_AFRT || r->action == PF_DROP) { 6753 dirndx = (pd->dir == PF_OUT); 6754 r->packets[dirndx]++; 6755 r->bytes[dirndx] += pd->tot_len; 6756 if (a != NULL) { 6757 a->packets[dirndx]++; 6758 a->bytes[dirndx] += pd->tot_len; 6759 } 6760 if (s != NULL) { 6761 struct pf_rule_item *ri; 6762 struct pf_sn_item *sni; 6763 6764 SLIST_FOREACH(sni, &s->src_nodes, next) { 6765 sni->sn->packets[dirndx]++; 6766 sni->sn->bytes[dirndx] += pd->tot_len; 6767 } 6768 dirndx = (pd->dir == s->direction) ? 0 : 1; 6769 s->packets[dirndx]++; 6770 s->bytes[dirndx] += pd->tot_len; 6771 6772 SLIST_FOREACH(ri, &s->match_rules, entry) { 6773 ri->r->packets[dirndx]++; 6774 ri->r->bytes[dirndx] += pd->tot_len; 6775 6776 if (ri->r->src.addr.type == PF_ADDR_TABLE) 6777 pfr_update_stats(ri->r->src.addr.p.tbl, 6778 &s->key[(s->direction == PF_IN)]-> 6779 addr[(s->direction == PF_OUT)], 6780 pd, ri->r->action, ri->r->src.neg); 6781 if (ri->r->dst.addr.type == PF_ADDR_TABLE) 6782 pfr_update_stats(ri->r->dst.addr.p.tbl, 6783 &s->key[(s->direction == PF_IN)]-> 6784 addr[(s->direction == PF_IN)], 6785 pd, ri->r->action, ri->r->dst.neg); 6786 } 6787 } 6788 if (r->src.addr.type == PF_ADDR_TABLE) 6789 pfr_update_stats(r->src.addr.p.tbl, 6790 (s == NULL) ? pd->src : 6791 &s->key[(s->direction == PF_IN)]-> 6792 addr[(s->direction == PF_OUT)], 6793 pd, r->action, r->src.neg); 6794 if (r->dst.addr.type == PF_ADDR_TABLE) 6795 pfr_update_stats(r->dst.addr.p.tbl, 6796 (s == NULL) ? pd->dst : 6797 &s->key[(s->direction == PF_IN)]-> 6798 addr[(s->direction == PF_IN)], 6799 pd, r->action, r->dst.neg); 6800 } 6801 } 6802 6803 int 6804 pf_test(sa_family_t af, int fwdir, struct ifnet *ifp, struct mbuf **m0) 6805 { 6806 #if NCARP > 0 6807 struct ifnet *ifp0; 6808 #endif 6809 struct pfi_kif *kif; 6810 u_short action, reason = 0; 6811 struct pf_rule *a = NULL, *r = &pf_default_rule; 6812 struct pf_state *s = NULL; 6813 struct pf_ruleset *ruleset = NULL; 6814 struct pf_pdesc pd; 6815 int dir = (fwdir == PF_FWD) ? PF_OUT : fwdir; 6816 u_int32_t qid, pqid = 0; 6817 int have_pf_lock = 0; 6818 6819 if (!pf_status.running) 6820 return (PF_PASS); 6821 6822 #if NCARP > 0 6823 if (ifp->if_type == IFT_CARP && 6824 (ifp0 = if_get(ifp->if_carpdevidx)) != NULL) { 6825 kif = (struct pfi_kif *)ifp0->if_pf_kif; 6826 if_put(ifp0); 6827 } else 6828 #endif /* NCARP */ 6829 kif = (struct pfi_kif *)ifp->if_pf_kif; 6830 6831 if (kif == NULL) { 6832 DPFPRINTF(LOG_ERR, 6833 "%s: kif == NULL, if_xname %s", __func__, ifp->if_xname); 6834 return (PF_DROP); 6835 } 6836 if (kif->pfik_flags & PFI_IFLAG_SKIP) 6837 return (PF_PASS); 6838 6839 #ifdef DIAGNOSTIC 6840 if (((*m0)->m_flags & M_PKTHDR) == 0) 6841 panic("non-M_PKTHDR is passed to pf_test"); 6842 #endif /* DIAGNOSTIC */ 6843 6844 if ((*m0)->m_pkthdr.pf.flags & PF_TAG_GENERATED) 6845 return (PF_PASS); 6846 6847 if ((*m0)->m_pkthdr.pf.flags & PF_TAG_DIVERTED_PACKET) { 6848 (*m0)->m_pkthdr.pf.flags &= ~PF_TAG_DIVERTED_PACKET; 6849 return (PF_PASS); 6850 } 6851 6852 if ((*m0)->m_pkthdr.pf.flags & PF_TAG_REFRAGMENTED) { 6853 (*m0)->m_pkthdr.pf.flags &= ~PF_TAG_REFRAGMENTED; 6854 return (PF_PASS); 6855 } 6856 6857 action = pf_setup_pdesc(&pd, af, dir, kif, *m0, &reason); 6858 if (action != PF_PASS) { 6859 #if NPFLOG > 0 6860 pd.pflog |= PF_LOG_FORCE; 6861 #endif /* NPFLOG > 0 */ 6862 goto done; 6863 } 6864 6865 /* packet normalization and reassembly */ 6866 switch (pd.af) { 6867 case AF_INET: 6868 action = pf_normalize_ip(&pd, &reason); 6869 break; 6870 #ifdef INET6 6871 case AF_INET6: 6872 action = pf_normalize_ip6(&pd, &reason); 6873 break; 6874 #endif /* INET6 */ 6875 } 6876 *m0 = pd.m; 6877 /* if packet sits in reassembly queue, return without error */ 6878 if (pd.m == NULL) 6879 return PF_PASS; 6880 6881 if (action != PF_PASS) { 6882 #if NPFLOG > 0 6883 pd.pflog |= PF_LOG_FORCE; 6884 #endif /* NPFLOG > 0 */ 6885 goto done; 6886 } 6887 6888 /* if packet has been reassembled, update packet description */ 6889 if (pf_status.reass && pd.virtual_proto == PF_VPROTO_FRAGMENT) { 6890 action = pf_setup_pdesc(&pd, af, dir, kif, pd.m, &reason); 6891 if (action != PF_PASS) { 6892 #if NPFLOG > 0 6893 pd.pflog |= PF_LOG_FORCE; 6894 #endif /* NPFLOG > 0 */ 6895 goto done; 6896 } 6897 } 6898 pd.m->m_pkthdr.pf.flags |= PF_TAG_PROCESSED; 6899 6900 /* 6901 * Avoid pcb-lookups from the forwarding path. They should never 6902 * match and would cause MP locking problems. 6903 */ 6904 if (fwdir == PF_FWD) { 6905 pd.lookup.done = -1; 6906 pd.lookup.uid = -1; 6907 pd.lookup.gid = -1; 6908 pd.lookup.pid = NO_PID; 6909 } 6910 6911 switch (pd.virtual_proto) { 6912 6913 case PF_VPROTO_FRAGMENT: { 6914 /* 6915 * handle fragments that aren't reassembled by 6916 * normalization 6917 */ 6918 PF_LOCK(); 6919 have_pf_lock = 1; 6920 action = pf_test_rule(&pd, &r, &s, &a, &ruleset, &reason); 6921 s = pf_state_ref(s); 6922 if (action != PF_PASS) 6923 REASON_SET(&reason, PFRES_FRAG); 6924 break; 6925 } 6926 6927 case IPPROTO_ICMP: { 6928 if (pd.af != AF_INET) { 6929 action = PF_DROP; 6930 REASON_SET(&reason, PFRES_NORM); 6931 DPFPRINTF(LOG_NOTICE, 6932 "dropping IPv6 packet with ICMPv4 payload"); 6933 break; 6934 } 6935 PF_STATE_ENTER_READ(); 6936 action = pf_test_state_icmp(&pd, &s, &reason); 6937 s = pf_state_ref(s); 6938 PF_STATE_EXIT_READ(); 6939 if (action == PF_PASS || action == PF_AFRT) { 6940 #if NPFSYNC > 0 6941 pfsync_update_state(s); 6942 #endif /* NPFSYNC > 0 */ 6943 r = s->rule.ptr; 6944 a = s->anchor.ptr; 6945 #if NPFLOG > 0 6946 pd.pflog |= s->log; 6947 #endif /* NPFLOG > 0 */ 6948 } else if (s == NULL) { 6949 PF_LOCK(); 6950 have_pf_lock = 1; 6951 action = pf_test_rule(&pd, &r, &s, &a, &ruleset, 6952 &reason); 6953 s = pf_state_ref(s); 6954 } 6955 break; 6956 } 6957 6958 #ifdef INET6 6959 case IPPROTO_ICMPV6: { 6960 if (pd.af != AF_INET6) { 6961 action = PF_DROP; 6962 REASON_SET(&reason, PFRES_NORM); 6963 DPFPRINTF(LOG_NOTICE, 6964 "dropping IPv4 packet with ICMPv6 payload"); 6965 break; 6966 } 6967 PF_STATE_ENTER_READ(); 6968 action = pf_test_state_icmp(&pd, &s, &reason); 6969 s = pf_state_ref(s); 6970 PF_STATE_EXIT_READ(); 6971 if (action == PF_PASS || action == PF_AFRT) { 6972 #if NPFSYNC > 0 6973 pfsync_update_state(s); 6974 #endif /* NPFSYNC > 0 */ 6975 r = s->rule.ptr; 6976 a = s->anchor.ptr; 6977 #if NPFLOG > 0 6978 pd.pflog |= s->log; 6979 #endif /* NPFLOG > 0 */ 6980 } else if (s == NULL) { 6981 PF_LOCK(); 6982 have_pf_lock = 1; 6983 action = pf_test_rule(&pd, &r, &s, &a, &ruleset, 6984 &reason); 6985 s = pf_state_ref(s); 6986 } 6987 break; 6988 } 6989 #endif /* INET6 */ 6990 6991 default: 6992 if (pd.virtual_proto == IPPROTO_TCP) { 6993 if (pd.dir == PF_IN && (pd.hdr.tcp.th_flags & 6994 (TH_SYN|TH_ACK)) == TH_SYN && 6995 pf_synflood_check(&pd)) { 6996 PF_LOCK(); 6997 have_pf_lock = 1; 6998 pf_syncookie_send(&pd); 6999 action = PF_DROP; 7000 break; 7001 } 7002 if ((pd.hdr.tcp.th_flags & TH_ACK) && pd.p_len == 0) 7003 pqid = 1; 7004 action = pf_normalize_tcp(&pd); 7005 if (action == PF_DROP) 7006 break; 7007 } 7008 PF_STATE_ENTER_READ(); 7009 action = pf_test_state(&pd, &s, &reason, 0); 7010 s = pf_state_ref(s); 7011 PF_STATE_EXIT_READ(); 7012 if (s == NULL && action != PF_PASS && action != PF_AFRT && 7013 pd.dir == PF_IN && pd.virtual_proto == IPPROTO_TCP && 7014 (pd.hdr.tcp.th_flags & (TH_SYN|TH_ACK|TH_RST)) == TH_ACK && 7015 pf_syncookie_validate(&pd)) { 7016 struct mbuf *msyn; 7017 msyn = pf_syncookie_recreate_syn(&pd); 7018 if (msyn) { 7019 action = pf_test(af, fwdir, ifp, &msyn); 7020 m_freem(msyn); 7021 if (action == PF_PASS || action == PF_AFRT) { 7022 PF_STATE_ENTER_READ(); 7023 pf_test_state(&pd, &s, &reason, 1); 7024 s = pf_state_ref(s); 7025 PF_STATE_EXIT_READ(); 7026 if (s == NULL) 7027 return (PF_DROP); 7028 s->src.seqhi = 7029 ntohl(pd.hdr.tcp.th_ack) - 1; 7030 s->src.seqlo = 7031 ntohl(pd.hdr.tcp.th_seq) - 1; 7032 pf_set_protostate(s, PF_PEER_SRC, 7033 PF_TCPS_PROXY_DST); 7034 PF_LOCK(); 7035 have_pf_lock = 1; 7036 action = pf_synproxy(&pd, &s, &reason); 7037 if (action != PF_PASS) { 7038 PF_UNLOCK(); 7039 pf_state_unref(s); 7040 return (action); 7041 } 7042 } 7043 } else 7044 action = PF_DROP; 7045 } 7046 7047 if (action == PF_PASS || action == PF_AFRT) { 7048 #if NPFSYNC > 0 7049 pfsync_update_state(s); 7050 #endif /* NPFSYNC > 0 */ 7051 r = s->rule.ptr; 7052 a = s->anchor.ptr; 7053 #if NPFLOG > 0 7054 pd.pflog |= s->log; 7055 #endif /* NPFLOG > 0 */ 7056 } else if (s == NULL) { 7057 PF_LOCK(); 7058 have_pf_lock = 1; 7059 action = pf_test_rule(&pd, &r, &s, &a, &ruleset, 7060 &reason); 7061 s = pf_state_ref(s); 7062 } 7063 7064 if (pd.virtual_proto == IPPROTO_TCP) { 7065 if (s) { 7066 if (s->max_mss) 7067 pf_normalize_mss(&pd, s->max_mss); 7068 } else if (r->max_mss) 7069 pf_normalize_mss(&pd, r->max_mss); 7070 } 7071 7072 break; 7073 } 7074 7075 if (have_pf_lock != 0) 7076 PF_UNLOCK(); 7077 7078 /* 7079 * At the moment, we rely on NET_LOCK() to prevent removal of items 7080 * we've collected above ('r', 'anchor' and 'ruleset'). They'll have 7081 * to be refcounted when NET_LOCK() is gone. 7082 */ 7083 7084 done: 7085 if (action != PF_DROP) { 7086 if (s) { 7087 /* The non-state case is handled in pf_test_rule() */ 7088 if (action == PF_PASS && pd.badopts && 7089 !(s->state_flags & PFSTATE_ALLOWOPTS)) { 7090 action = PF_DROP; 7091 REASON_SET(&reason, PFRES_IPOPTIONS); 7092 #if NPFLOG > 0 7093 pd.pflog |= PF_LOG_FORCE; 7094 #endif /* NPFLOG > 0 */ 7095 DPFPRINTF(LOG_NOTICE, "dropping packet with " 7096 "ip/ipv6 options in pf_test()"); 7097 } 7098 7099 pf_scrub(pd.m, s->state_flags, pd.af, s->min_ttl, 7100 s->set_tos); 7101 pf_tag_packet(pd.m, s->tag, s->rtableid[pd.didx]); 7102 if (pqid || (pd.tos & IPTOS_LOWDELAY)) { 7103 qid = s->pqid; 7104 if (s->state_flags & PFSTATE_SETPRIO) 7105 pd.m->m_pkthdr.pf.prio = s->set_prio[1]; 7106 } else { 7107 qid = s->qid; 7108 if (s->state_flags & PFSTATE_SETPRIO) 7109 pd.m->m_pkthdr.pf.prio = s->set_prio[0]; 7110 } 7111 pd.m->m_pkthdr.pf.delay = s->delay; 7112 } else { 7113 pf_scrub(pd.m, r->scrub_flags, pd.af, r->min_ttl, 7114 r->set_tos); 7115 if (pqid || (pd.tos & IPTOS_LOWDELAY)) { 7116 qid = r->pqid; 7117 if (r->scrub_flags & PFSTATE_SETPRIO) 7118 pd.m->m_pkthdr.pf.prio = r->set_prio[1]; 7119 } else { 7120 qid = r->qid; 7121 if (r->scrub_flags & PFSTATE_SETPRIO) 7122 pd.m->m_pkthdr.pf.prio = r->set_prio[0]; 7123 } 7124 pd.m->m_pkthdr.pf.delay = r->delay; 7125 } 7126 } 7127 7128 if (action == PF_PASS && qid) 7129 pd.m->m_pkthdr.pf.qid = qid; 7130 if (pd.dir == PF_IN && s && s->key[PF_SK_STACK]) 7131 pf_mbuf_link_state_key(pd.m, s->key[PF_SK_STACK]); 7132 if (pd.dir == PF_OUT && 7133 pd.m->m_pkthdr.pf.inp && !pd.m->m_pkthdr.pf.inp->inp_pf_sk && 7134 s && s->key[PF_SK_STACK] && !s->key[PF_SK_STACK]->inp) 7135 pf_state_key_link_inpcb(s->key[PF_SK_STACK], 7136 pd.m->m_pkthdr.pf.inp); 7137 7138 if (s != NULL && !ISSET(pd.m->m_pkthdr.csum_flags, M_FLOWID)) { 7139 pd.m->m_pkthdr.ph_flowid = bemtoh64(&s->id); 7140 SET(pd.m->m_pkthdr.csum_flags, M_FLOWID); 7141 } 7142 7143 /* 7144 * connections redirected to loopback should not match sockets 7145 * bound specifically to loopback due to security implications, 7146 * see in_pcblookup_listen(). 7147 */ 7148 if (pd.destchg) 7149 if ((pd.af == AF_INET && (ntohl(pd.dst->v4.s_addr) >> 7150 IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) || 7151 (pd.af == AF_INET6 && IN6_IS_ADDR_LOOPBACK(&pd.dst->v6))) 7152 pd.m->m_pkthdr.pf.flags |= PF_TAG_TRANSLATE_LOCALHOST; 7153 /* We need to redo the route lookup on outgoing routes. */ 7154 if (pd.destchg && pd.dir == PF_OUT) 7155 pd.m->m_pkthdr.pf.flags |= PF_TAG_REROUTE; 7156 7157 if (pd.dir == PF_IN && action == PF_PASS && 7158 (r->divert.type == PF_DIVERT_TO || 7159 r->divert.type == PF_DIVERT_REPLY)) { 7160 struct pf_divert *divert; 7161 7162 if ((divert = pf_get_divert(pd.m))) { 7163 pd.m->m_pkthdr.pf.flags |= PF_TAG_DIVERTED; 7164 divert->addr = r->divert.addr; 7165 divert->port = r->divert.port; 7166 divert->rdomain = pd.rdomain; 7167 divert->type = r->divert.type; 7168 } 7169 } 7170 7171 if (action == PF_PASS && r->divert.type == PF_DIVERT_PACKET) 7172 action = PF_DIVERT; 7173 7174 #if NPFLOG > 0 7175 if (pd.pflog) { 7176 struct pf_rule_item *ri; 7177 7178 if (pd.pflog & PF_LOG_FORCE || r->log & PF_LOG_ALL) 7179 pflog_packet(&pd, reason, r, a, ruleset, NULL); 7180 if (s) { 7181 SLIST_FOREACH(ri, &s->match_rules, entry) 7182 if (ri->r->log & PF_LOG_ALL) 7183 pflog_packet(&pd, reason, ri->r, a, 7184 ruleset, NULL); 7185 } 7186 } 7187 #endif /* NPFLOG > 0 */ 7188 7189 pf_counters_inc(action, &pd, s, r, a); 7190 7191 switch (action) { 7192 case PF_SYNPROXY_DROP: 7193 m_freem(pd.m); 7194 /* FALLTHROUGH */ 7195 case PF_DEFER: 7196 pd.m = NULL; 7197 action = PF_PASS; 7198 break; 7199 case PF_DIVERT: 7200 switch (pd.af) { 7201 case AF_INET: 7202 if (!divert_packet(pd.m, pd.dir, r->divert.port)) 7203 pd.m = NULL; 7204 break; 7205 #ifdef INET6 7206 case AF_INET6: 7207 if (!divert6_packet(pd.m, pd.dir, r->divert.port)) 7208 pd.m = NULL; 7209 break; 7210 #endif /* INET6 */ 7211 } 7212 action = PF_PASS; 7213 break; 7214 #ifdef INET6 7215 case PF_AFRT: 7216 if (pf_translate_af(&pd)) { 7217 action = PF_DROP; 7218 break; 7219 } 7220 pd.m->m_pkthdr.pf.flags |= PF_TAG_GENERATED; 7221 switch (pd.naf) { 7222 case AF_INET: 7223 if (pd.dir == PF_IN) { 7224 if (ipforwarding == 0) { 7225 ipstat_inc(ips_cantforward); 7226 action = PF_DROP; 7227 break; 7228 } 7229 ip_forward(pd.m, ifp, NULL, 1); 7230 } else 7231 ip_output(pd.m, NULL, NULL, 0, NULL, NULL, 0); 7232 break; 7233 case AF_INET6: 7234 if (pd.dir == PF_IN) { 7235 if (ip6_forwarding == 0) { 7236 ip6stat_inc(ip6s_cantforward); 7237 action = PF_DROP; 7238 break; 7239 } 7240 ip6_forward(pd.m, NULL, 1); 7241 } else 7242 ip6_output(pd.m, NULL, NULL, 0, NULL, NULL); 7243 break; 7244 } 7245 if (action != PF_DROP) { 7246 pd.m = NULL; 7247 action = PF_PASS; 7248 } 7249 break; 7250 #endif /* INET6 */ 7251 case PF_DROP: 7252 m_freem(pd.m); 7253 pd.m = NULL; 7254 break; 7255 default: 7256 if (s && s->rt) { 7257 switch (pd.af) { 7258 case AF_INET: 7259 pf_route(&pd, s); 7260 break; 7261 #ifdef INET6 7262 case AF_INET6: 7263 pf_route6(&pd, s); 7264 break; 7265 #endif /* INET6 */ 7266 } 7267 } 7268 break; 7269 } 7270 7271 #ifdef INET6 7272 /* if reassembled packet passed, create new fragments */ 7273 if (pf_status.reass && action == PF_PASS && pd.m && fwdir == PF_FWD && 7274 pd.af == AF_INET6) { 7275 struct m_tag *mtag; 7276 7277 if ((mtag = m_tag_find(pd.m, PACKET_TAG_PF_REASSEMBLED, NULL))) 7278 action = pf_refragment6(&pd.m, mtag, NULL, NULL, NULL); 7279 } 7280 #endif /* INET6 */ 7281 if (s && action != PF_DROP) { 7282 if (!s->if_index_in && dir == PF_IN) 7283 s->if_index_in = ifp->if_index; 7284 else if (!s->if_index_out && dir == PF_OUT) 7285 s->if_index_out = ifp->if_index; 7286 } 7287 7288 *m0 = pd.m; 7289 7290 pf_state_unref(s); 7291 7292 return (action); 7293 } 7294 7295 int 7296 pf_ouraddr(struct mbuf *m) 7297 { 7298 struct pf_state_key *sk; 7299 7300 if (m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) 7301 return (1); 7302 7303 sk = m->m_pkthdr.pf.statekey; 7304 if (sk != NULL) { 7305 if (sk->inp != NULL) 7306 return (1); 7307 } 7308 7309 return (-1); 7310 } 7311 7312 /* 7313 * must be called whenever any addressing information such as 7314 * address, port, protocol has changed 7315 */ 7316 void 7317 pf_pkt_addr_changed(struct mbuf *m) 7318 { 7319 pf_mbuf_unlink_state_key(m); 7320 pf_mbuf_unlink_inpcb(m); 7321 } 7322 7323 struct inpcb * 7324 pf_inp_lookup(struct mbuf *m) 7325 { 7326 struct inpcb *inp = NULL; 7327 struct pf_state_key *sk = m->m_pkthdr.pf.statekey; 7328 7329 if (!pf_state_key_isvalid(sk)) 7330 pf_mbuf_unlink_state_key(m); 7331 else 7332 inp = m->m_pkthdr.pf.statekey->inp; 7333 7334 if (inp && inp->inp_pf_sk) 7335 KASSERT(m->m_pkthdr.pf.statekey == inp->inp_pf_sk); 7336 7337 return (inp); 7338 } 7339 7340 void 7341 pf_inp_link(struct mbuf *m, struct inpcb *inp) 7342 { 7343 struct pf_state_key *sk = m->m_pkthdr.pf.statekey; 7344 7345 if (!pf_state_key_isvalid(sk)) { 7346 pf_mbuf_unlink_state_key(m); 7347 return; 7348 } 7349 7350 /* 7351 * we don't need to grab PF-lock here. At worst case we link inp to 7352 * state, which might be just being marked as deleted by another 7353 * thread. 7354 */ 7355 if (inp && !sk->inp && !inp->inp_pf_sk) 7356 pf_state_key_link_inpcb(sk, inp); 7357 7358 /* The statekey has finished finding the inp, it is no longer needed. */ 7359 pf_mbuf_unlink_state_key(m); 7360 } 7361 7362 void 7363 pf_inp_unlink(struct inpcb *inp) 7364 { 7365 pf_inpcb_unlink_state_key(inp); 7366 } 7367 7368 void 7369 pf_state_key_link_reverse(struct pf_state_key *sk, struct pf_state_key *skrev) 7370 { 7371 struct pf_state_key *old_reverse; 7372 7373 old_reverse = atomic_cas_ptr(&sk->reverse, NULL, skrev); 7374 if (old_reverse != NULL) 7375 KASSERT(old_reverse == skrev); 7376 else 7377 pf_state_key_ref(skrev); 7378 7379 old_reverse = atomic_cas_ptr(&skrev->reverse, NULL, sk); 7380 if (old_reverse != NULL) 7381 KASSERT(old_reverse == sk); 7382 else 7383 pf_state_key_ref(sk); 7384 } 7385 7386 #if NPFLOG > 0 7387 void 7388 pf_log_matches(struct pf_pdesc *pd, struct pf_rule *rm, struct pf_rule *am, 7389 struct pf_ruleset *ruleset, struct pf_rule_slist *matchrules) 7390 { 7391 struct pf_rule_item *ri; 7392 7393 /* if this is the log(matches) rule, packet has been logged already */ 7394 if (rm->log & PF_LOG_MATCHES) 7395 return; 7396 7397 SLIST_FOREACH(ri, matchrules, entry) 7398 if (ri->r->log & PF_LOG_MATCHES) 7399 pflog_packet(pd, PFRES_MATCH, rm, am, ruleset, ri->r); 7400 } 7401 #endif /* NPFLOG > 0 */ 7402 7403 struct pf_state_key * 7404 pf_state_key_ref(struct pf_state_key *sk) 7405 { 7406 if (sk != NULL) 7407 PF_REF_TAKE(sk->refcnt); 7408 7409 return (sk); 7410 } 7411 7412 void 7413 pf_state_key_unref(struct pf_state_key *sk) 7414 { 7415 if (PF_REF_RELE(sk->refcnt)) { 7416 /* state key must be removed from tree */ 7417 KASSERT(!pf_state_key_isvalid(sk)); 7418 /* state key must be unlinked from reverse key */ 7419 KASSERT(sk->reverse == NULL); 7420 /* state key must be unlinked from socket */ 7421 KASSERT(sk->inp == NULL); 7422 pool_put(&pf_state_key_pl, sk); 7423 } 7424 } 7425 7426 int 7427 pf_state_key_isvalid(struct pf_state_key *sk) 7428 { 7429 return ((sk != NULL) && (sk->removed == 0)); 7430 } 7431 7432 void 7433 pf_mbuf_link_state_key(struct mbuf *m, struct pf_state_key *sk) 7434 { 7435 KASSERT(m->m_pkthdr.pf.statekey == NULL); 7436 m->m_pkthdr.pf.statekey = pf_state_key_ref(sk); 7437 } 7438 7439 void 7440 pf_mbuf_unlink_state_key(struct mbuf *m) 7441 { 7442 struct pf_state_key *sk = m->m_pkthdr.pf.statekey; 7443 7444 if (sk != NULL) { 7445 m->m_pkthdr.pf.statekey = NULL; 7446 pf_state_key_unref(sk); 7447 } 7448 } 7449 7450 void 7451 pf_mbuf_link_inpcb(struct mbuf *m, struct inpcb *inp) 7452 { 7453 KASSERT(m->m_pkthdr.pf.inp == NULL); 7454 m->m_pkthdr.pf.inp = in_pcbref(inp); 7455 } 7456 7457 void 7458 pf_mbuf_unlink_inpcb(struct mbuf *m) 7459 { 7460 struct inpcb *inp = m->m_pkthdr.pf.inp; 7461 7462 if (inp != NULL) { 7463 m->m_pkthdr.pf.inp = NULL; 7464 in_pcbunref(inp); 7465 } 7466 } 7467 7468 void 7469 pf_state_key_link_inpcb(struct pf_state_key *sk, struct inpcb *inp) 7470 { 7471 KASSERT(sk->inp == NULL); 7472 sk->inp = in_pcbref(inp); 7473 KASSERT(inp->inp_pf_sk == NULL); 7474 inp->inp_pf_sk = pf_state_key_ref(sk); 7475 } 7476 7477 void 7478 pf_inpcb_unlink_state_key(struct inpcb *inp) 7479 { 7480 struct pf_state_key *sk = inp->inp_pf_sk; 7481 7482 if (sk != NULL) { 7483 KASSERT(sk->inp == inp); 7484 sk->inp = NULL; 7485 inp->inp_pf_sk = NULL; 7486 pf_state_key_unref(sk); 7487 in_pcbunref(inp); 7488 } 7489 } 7490 7491 void 7492 pf_state_key_unlink_inpcb(struct pf_state_key *sk) 7493 { 7494 struct inpcb *inp = sk->inp; 7495 7496 if (inp != NULL) { 7497 KASSERT(inp->inp_pf_sk == sk); 7498 sk->inp = NULL; 7499 inp->inp_pf_sk = NULL; 7500 pf_state_key_unref(sk); 7501 in_pcbunref(inp); 7502 } 7503 } 7504 7505 void 7506 pf_state_key_unlink_reverse(struct pf_state_key *sk) 7507 { 7508 struct pf_state_key *skrev = sk->reverse; 7509 7510 /* Note that sk and skrev may be equal, then we unref twice. */ 7511 if (skrev != NULL) { 7512 KASSERT(skrev->reverse == sk); 7513 sk->reverse = NULL; 7514 skrev->reverse = NULL; 7515 pf_state_key_unref(skrev); 7516 pf_state_key_unref(sk); 7517 } 7518 } 7519 7520 struct pf_state * 7521 pf_state_ref(struct pf_state *s) 7522 { 7523 if (s != NULL) 7524 PF_REF_TAKE(s->refcnt); 7525 return (s); 7526 } 7527 7528 void 7529 pf_state_unref(struct pf_state *s) 7530 { 7531 if ((s != NULL) && PF_REF_RELE(s->refcnt)) { 7532 /* never inserted or removed */ 7533 #if NPFSYNC > 0 7534 KASSERT((TAILQ_NEXT(s, sync_list) == NULL) || 7535 ((TAILQ_NEXT(s, sync_list) == _Q_INVALID) && 7536 (s->sync_state == PFSYNC_S_NONE))); 7537 #endif /* NPFSYNC */ 7538 KASSERT((TAILQ_NEXT(s, entry_list) == NULL) || 7539 (TAILQ_NEXT(s, entry_list) == _Q_INVALID)); 7540 KASSERT((s->key[PF_SK_WIRE] == NULL) && 7541 (s->key[PF_SK_STACK] == NULL)); 7542 7543 pool_put(&pf_state_pl, s); 7544 } 7545 } 7546 7547 int 7548 pf_delay_pkt(struct mbuf *m, u_int ifidx) 7549 { 7550 struct pf_pktdelay *pdy; 7551 7552 if ((pdy = pool_get(&pf_pktdelay_pl, PR_NOWAIT)) == NULL) { 7553 m_freem(m); 7554 return (ENOBUFS); 7555 } 7556 pdy->ifidx = ifidx; 7557 pdy->m = m; 7558 timeout_set(&pdy->to, pf_pktenqueue_delayed, pdy); 7559 timeout_add_msec(&pdy->to, m->m_pkthdr.pf.delay); 7560 m->m_pkthdr.pf.delay = 0; 7561 return (0); 7562 } 7563 7564 void 7565 pf_pktenqueue_delayed(void *arg) 7566 { 7567 struct pf_pktdelay *pdy = arg; 7568 struct ifnet *ifp; 7569 7570 ifp = if_get(pdy->ifidx); 7571 if (ifp != NULL) { 7572 if_enqueue(ifp, pdy->m); 7573 if_put(ifp); 7574 } else 7575 m_freem(pdy->m); 7576 7577 pool_put(&pf_pktdelay_pl, pdy); 7578 } 7579