1 /* $OpenBSD: pf.c,v 1.1015 2017/02/09 15:19:32 jca 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/ip.h> 66 #include <netinet/in_pcb.h> 67 #include <netinet/ip_var.h> 68 #include <netinet/ip_icmp.h> 69 #include <netinet/icmp_var.h> 70 #include <netinet/tcp.h> 71 #include <netinet/tcp_seq.h> 72 #include <netinet/tcp_timer.h> 73 #include <netinet/tcp_var.h> 74 #include <netinet/tcp_fsm.h> 75 #include <netinet/udp.h> 76 #include <netinet/udp_var.h> 77 #include <netinet/ip_divert.h> 78 79 #ifdef INET6 80 #include <netinet/ip6.h> 81 #include <netinet6/ip6_var.h> 82 #include <netinet/icmp6.h> 83 #include <netinet6/nd6.h> 84 #include <netinet6/ip6_divert.h> 85 #endif /* INET6 */ 86 87 #include <net/pfvar.h> 88 #include <net/pfvar_priv.h> 89 90 #if NPFLOG > 0 91 #include <net/if_pflog.h> 92 #endif /* NPFLOG > 0 */ 93 94 #if NPFLOW > 0 95 #include <net/if_pflow.h> 96 #endif /* NPFLOW > 0 */ 97 98 #if NPFSYNC > 0 99 #include <net/if_pfsync.h> 100 #endif /* NPFSYNC > 0 */ 101 102 #ifdef DDB 103 #include <machine/db_machdep.h> 104 #include <ddb/db_interface.h> 105 #endif 106 107 /* 108 * Global variables 109 */ 110 struct pf_state_tree pf_statetbl; 111 struct pf_queuehead pf_queues[2]; 112 struct pf_queuehead *pf_queues_active; 113 struct pf_queuehead *pf_queues_inactive; 114 115 struct pf_status pf_status; 116 117 SHA2_CTX pf_tcp_secret_ctx; 118 u_char pf_tcp_secret[16]; 119 int pf_tcp_secret_init; 120 int pf_tcp_iss_off; 121 122 struct pf_anchor_stackframe { 123 struct pf_ruleset *rs; 124 struct pf_rule *r; 125 struct pf_anchor_node *parent; 126 struct pf_anchor *child; 127 } pf_anchor_stack[64]; 128 129 struct pool pf_src_tree_pl, pf_rule_pl, pf_queue_pl; 130 struct pool pf_state_pl, pf_state_key_pl, pf_state_item_pl; 131 struct pool pf_rule_item_pl, pf_sn_item_pl; 132 133 void pf_init_threshold(struct pf_threshold *, u_int32_t, 134 u_int32_t); 135 void pf_add_threshold(struct pf_threshold *); 136 int pf_check_threshold(struct pf_threshold *); 137 int pf_check_tcp_cksum(struct mbuf *, int, int, 138 sa_family_t); 139 static __inline void pf_cksum_fixup(u_int16_t *, u_int16_t, u_int16_t, 140 u_int8_t); 141 void pf_cksum_fixup_a(u_int16_t *, const struct pf_addr *, 142 const struct pf_addr *, sa_family_t, u_int8_t); 143 int pf_modulate_sack(struct pf_pdesc *, 144 struct pf_state_peer *); 145 int pf_icmp_mapping(struct pf_pdesc *, u_int8_t, int *, 146 u_int16_t *, u_int16_t *); 147 int pf_change_icmp_af(struct mbuf *, int, 148 struct pf_pdesc *, struct pf_pdesc *, 149 struct pf_addr *, struct pf_addr *, sa_family_t, 150 sa_family_t); 151 int pf_translate_a(struct pf_pdesc *, struct pf_addr *, 152 struct pf_addr *); 153 void pf_translate_icmp(struct pf_pdesc *, struct pf_addr *, 154 u_int16_t *, struct pf_addr *, struct pf_addr *, 155 u_int16_t); 156 int pf_translate_icmp_af(struct pf_pdesc*, int, void *); 157 void pf_send_icmp(struct mbuf *, u_int8_t, u_int8_t, 158 sa_family_t, struct pf_rule *, u_int); 159 void pf_detach_state(struct pf_state *); 160 void pf_state_key_detach(struct pf_state *, int); 161 u_int32_t pf_tcp_iss(struct pf_pdesc *); 162 void pf_rule_to_actions(struct pf_rule *, 163 struct pf_rule_actions *); 164 int pf_test_rule(struct pf_pdesc *, struct pf_rule **, 165 struct pf_state **, struct pf_rule **, 166 struct pf_ruleset **, u_short *); 167 static __inline int pf_create_state(struct pf_pdesc *, struct pf_rule *, 168 struct pf_rule *, struct pf_rule *, 169 struct pf_state_key **, struct pf_state_key **, 170 int *, struct pf_state **, int, 171 struct pf_rule_slist *, struct pf_rule_actions *, 172 struct pf_src_node *[]); 173 static __inline int pf_state_key_addr_setup(struct pf_pdesc *, void *, 174 int, struct pf_addr *, int, struct pf_addr *, 175 int, int); 176 int pf_state_key_setup(struct pf_pdesc *, struct 177 pf_state_key **, struct pf_state_key **, int); 178 int pf_tcp_track_full(struct pf_pdesc *, 179 struct pf_state_peer *, struct pf_state_peer *, 180 struct pf_state **, u_short *, int *); 181 int pf_tcp_track_sloppy(struct pf_pdesc *, 182 struct pf_state_peer *, struct pf_state_peer *, 183 struct pf_state **, u_short *); 184 static __inline int pf_synproxy(struct pf_pdesc *, struct pf_state **, 185 u_short *); 186 int pf_test_state(struct pf_pdesc *, struct pf_state **, 187 u_short *); 188 int pf_icmp_state_lookup(struct pf_pdesc *, 189 struct pf_state_key_cmp *, struct pf_state **, 190 u_int16_t, u_int16_t, int, int *, int, int); 191 int pf_test_state_icmp(struct pf_pdesc *, 192 struct pf_state **, u_short *); 193 u_int8_t pf_get_wscale(struct pf_pdesc *); 194 u_int16_t pf_get_mss(struct pf_pdesc *); 195 u_int16_t pf_calc_mss(struct pf_addr *, sa_family_t, int, 196 u_int16_t); 197 static __inline int pf_set_rt_ifp(struct pf_state *, struct pf_addr *, 198 sa_family_t); 199 struct pf_divert *pf_get_divert(struct mbuf *); 200 int pf_walk_option6(struct pf_pdesc *, struct ip6_hdr *, 201 int, int, u_short *); 202 int pf_walk_header6(struct pf_pdesc *, struct ip6_hdr *, 203 u_short *); 204 void pf_print_state_parts(struct pf_state *, 205 struct pf_state_key *, struct pf_state_key *); 206 int pf_addr_wrap_neq(struct pf_addr_wrap *, 207 struct pf_addr_wrap *); 208 int pf_compare_state_keys(struct pf_state_key *, 209 struct pf_state_key *, struct pfi_kif *, u_int); 210 struct pf_state *pf_find_state(struct pfi_kif *, 211 struct pf_state_key_cmp *, u_int, struct mbuf *); 212 int pf_src_connlimit(struct pf_state **); 213 int pf_match_rcvif(struct mbuf *, struct pf_rule *); 214 void pf_step_into_anchor(int *, struct pf_ruleset **, 215 struct pf_rule **, struct pf_rule **); 216 int pf_step_out_of_anchor(int *, struct pf_ruleset **, 217 struct pf_rule **, struct pf_rule **, 218 int *); 219 void pf_counters_inc(int, struct pf_pdesc *, 220 struct pf_state *, struct pf_rule *, 221 struct pf_rule *); 222 void pf_state_key_link(struct pf_state_key *, 223 struct pf_state_key *); 224 void pf_inpcb_unlink_state_key(struct inpcb *); 225 void pf_state_key_unlink_reverse(struct pf_state_key *); 226 227 #if NPFLOG > 0 228 void pf_log_matches(struct pf_pdesc *, struct pf_rule *, 229 struct pf_rule *, struct pf_ruleset *, 230 struct pf_rule_slist *); 231 #endif /* NPFLOG > 0 */ 232 233 extern struct pool pfr_ktable_pl; 234 extern struct pool pfr_kentry_pl; 235 236 struct pf_pool_limit pf_pool_limits[PF_LIMIT_MAX] = { 237 { &pf_state_pl, PFSTATE_HIWAT, PFSTATE_HIWAT }, 238 { &pf_src_tree_pl, PFSNODE_HIWAT, PFSNODE_HIWAT }, 239 { &pf_frent_pl, PFFRAG_FRENT_HIWAT, PFFRAG_FRENT_HIWAT }, 240 { &pfr_ktable_pl, PFR_KTABLE_HIWAT, PFR_KTABLE_HIWAT }, 241 { &pfr_kentry_pl, PFR_KENTRY_HIWAT, PFR_KENTRY_HIWAT } 242 }; 243 244 #define STATE_LOOKUP(i, k, d, s, m) \ 245 do { \ 246 s = pf_find_state(i, k, d, m); \ 247 if (s == NULL || (s)->timeout == PFTM_PURGE) \ 248 return (PF_DROP); \ 249 if (d == PF_OUT && \ 250 (((s)->rule.ptr->rt == PF_ROUTETO && \ 251 (s)->rule.ptr->direction == PF_OUT) || \ 252 ((s)->rule.ptr->rt == PF_REPLYTO && \ 253 (s)->rule.ptr->direction == PF_IN)) && \ 254 (s)->rt_kif != NULL && \ 255 (s)->rt_kif != i) \ 256 return (PF_PASS); \ 257 } while (0) 258 259 #define BOUND_IFACE(r, k) \ 260 ((r)->rule_flag & PFRULE_IFBOUND) ? (k) : pfi_all 261 262 #define STATE_INC_COUNTERS(s) \ 263 do { \ 264 struct pf_rule_item *mrm; \ 265 s->rule.ptr->states_cur++; \ 266 s->rule.ptr->states_tot++; \ 267 if (s->anchor.ptr != NULL) { \ 268 s->anchor.ptr->states_cur++; \ 269 s->anchor.ptr->states_tot++; \ 270 } \ 271 SLIST_FOREACH(mrm, &s->match_rules, entry) \ 272 mrm->r->states_cur++; \ 273 } while (0) 274 275 static __inline int pf_src_compare(struct pf_src_node *, struct pf_src_node *); 276 static __inline int pf_state_compare_key(struct pf_state_key *, 277 struct pf_state_key *); 278 static __inline int pf_state_compare_id(struct pf_state *, 279 struct pf_state *); 280 static __inline void pf_cksum_uncover(u_int16_t *, u_int16_t, u_int8_t); 281 static __inline void pf_cksum_cover(u_int16_t *, u_int16_t, u_int8_t); 282 283 struct pf_src_tree tree_src_tracking; 284 285 struct pf_state_tree_id tree_id; 286 struct pf_state_queue state_list; 287 288 RB_GENERATE(pf_src_tree, pf_src_node, entry, pf_src_compare); 289 RB_GENERATE(pf_state_tree, pf_state_key, entry, pf_state_compare_key); 290 RB_GENERATE(pf_state_tree_id, pf_state, 291 entry_id, pf_state_compare_id); 292 293 SLIST_HEAD(pf_rule_gcl, pf_rule) pf_rule_gcl = 294 SLIST_HEAD_INITIALIZER(pf_rule_gcl); 295 296 __inline int 297 pf_addr_compare(struct pf_addr *a, struct pf_addr *b, sa_family_t af) 298 { 299 switch (af) { 300 case AF_INET: 301 if (a->addr32[0] > b->addr32[0]) 302 return (1); 303 if (a->addr32[0] < b->addr32[0]) 304 return (-1); 305 break; 306 #ifdef INET6 307 case AF_INET6: 308 if (a->addr32[3] > b->addr32[3]) 309 return (1); 310 if (a->addr32[3] < b->addr32[3]) 311 return (-1); 312 if (a->addr32[2] > b->addr32[2]) 313 return (1); 314 if (a->addr32[2] < b->addr32[2]) 315 return (-1); 316 if (a->addr32[1] > b->addr32[1]) 317 return (1); 318 if (a->addr32[1] < b->addr32[1]) 319 return (-1); 320 if (a->addr32[0] > b->addr32[0]) 321 return (1); 322 if (a->addr32[0] < b->addr32[0]) 323 return (-1); 324 break; 325 #endif /* INET6 */ 326 } 327 return (0); 328 } 329 330 static __inline int 331 pf_src_compare(struct pf_src_node *a, struct pf_src_node *b) 332 { 333 int diff; 334 335 if (a->rule.ptr > b->rule.ptr) 336 return (1); 337 if (a->rule.ptr < b->rule.ptr) 338 return (-1); 339 if ((diff = a->type - b->type) != 0) 340 return (diff); 341 if ((diff = a->af - b->af) != 0) 342 return (diff); 343 if ((diff = pf_addr_compare(&a->addr, &b->addr, a->af)) != 0) 344 return (diff); 345 return (0); 346 } 347 348 void 349 pf_addrcpy(struct pf_addr *dst, struct pf_addr *src, sa_family_t af) 350 { 351 switch (af) { 352 case AF_INET: 353 dst->addr32[0] = src->addr32[0]; 354 break; 355 #ifdef INET6 356 case AF_INET6: 357 dst->addr32[0] = src->addr32[0]; 358 dst->addr32[1] = src->addr32[1]; 359 dst->addr32[2] = src->addr32[2]; 360 dst->addr32[3] = src->addr32[3]; 361 break; 362 #endif /* INET6 */ 363 default: 364 unhandled_af(af); 365 } 366 } 367 368 void 369 pf_init_threshold(struct pf_threshold *threshold, 370 u_int32_t limit, u_int32_t seconds) 371 { 372 threshold->limit = limit * PF_THRESHOLD_MULT; 373 threshold->seconds = seconds; 374 threshold->count = 0; 375 threshold->last = time_uptime; 376 } 377 378 void 379 pf_add_threshold(struct pf_threshold *threshold) 380 { 381 u_int32_t t = time_uptime, diff = t - threshold->last; 382 383 if (diff >= threshold->seconds) 384 threshold->count = 0; 385 else 386 threshold->count -= threshold->count * diff / 387 threshold->seconds; 388 threshold->count += PF_THRESHOLD_MULT; 389 threshold->last = t; 390 } 391 392 int 393 pf_check_threshold(struct pf_threshold *threshold) 394 { 395 return (threshold->count > threshold->limit); 396 } 397 398 int 399 pf_src_connlimit(struct pf_state **state) 400 { 401 int bad = 0; 402 struct pf_src_node *sn; 403 404 if ((sn = pf_get_src_node((*state), PF_SN_NONE)) == NULL) 405 return (0); 406 407 sn->conn++; 408 (*state)->src.tcp_est = 1; 409 pf_add_threshold(&sn->conn_rate); 410 411 if ((*state)->rule.ptr->max_src_conn && 412 (*state)->rule.ptr->max_src_conn < sn->conn) { 413 pf_status.lcounters[LCNT_SRCCONN]++; 414 bad++; 415 } 416 417 if ((*state)->rule.ptr->max_src_conn_rate.limit && 418 pf_check_threshold(&sn->conn_rate)) { 419 pf_status.lcounters[LCNT_SRCCONNRATE]++; 420 bad++; 421 } 422 423 if (!bad) 424 return (0); 425 426 if ((*state)->rule.ptr->overload_tbl) { 427 struct pfr_addr p; 428 u_int32_t killed = 0; 429 430 pf_status.lcounters[LCNT_OVERLOAD_TABLE]++; 431 if (pf_status.debug >= LOG_NOTICE) { 432 log(LOG_NOTICE, 433 "pf: pf_src_connlimit: blocking address "); 434 pf_print_host(&sn->addr, 0, 435 (*state)->key[PF_SK_WIRE]->af); 436 } 437 438 bzero(&p, sizeof(p)); 439 p.pfra_af = (*state)->key[PF_SK_WIRE]->af; 440 switch ((*state)->key[PF_SK_WIRE]->af) { 441 case AF_INET: 442 p.pfra_net = 32; 443 p.pfra_ip4addr = sn->addr.v4; 444 break; 445 #ifdef INET6 446 case AF_INET6: 447 p.pfra_net = 128; 448 p.pfra_ip6addr = sn->addr.v6; 449 break; 450 #endif /* INET6 */ 451 } 452 453 pfr_insert_kentry((*state)->rule.ptr->overload_tbl, 454 &p, time_second); 455 456 /* kill existing states if that's required. */ 457 if ((*state)->rule.ptr->flush) { 458 struct pf_state_key *sk; 459 struct pf_state *st; 460 461 pf_status.lcounters[LCNT_OVERLOAD_FLUSH]++; 462 RB_FOREACH(st, pf_state_tree_id, &tree_id) { 463 sk = st->key[PF_SK_WIRE]; 464 /* 465 * Kill states from this source. (Only those 466 * from the same rule if PF_FLUSH_GLOBAL is not 467 * set) 468 */ 469 if (sk->af == 470 (*state)->key[PF_SK_WIRE]->af && 471 (((*state)->direction == PF_OUT && 472 PF_AEQ(&sn->addr, &sk->addr[1], sk->af)) || 473 ((*state)->direction == PF_IN && 474 PF_AEQ(&sn->addr, &sk->addr[0], sk->af))) && 475 ((*state)->rule.ptr->flush & 476 PF_FLUSH_GLOBAL || 477 (*state)->rule.ptr == st->rule.ptr)) { 478 st->timeout = PFTM_PURGE; 479 st->src.state = st->dst.state = 480 TCPS_CLOSED; 481 killed++; 482 } 483 } 484 if (pf_status.debug >= LOG_NOTICE) 485 addlog(", %u states killed", killed); 486 } 487 if (pf_status.debug >= LOG_NOTICE) 488 addlog("\n"); 489 } 490 491 /* kill this state */ 492 (*state)->timeout = PFTM_PURGE; 493 (*state)->src.state = (*state)->dst.state = TCPS_CLOSED; 494 return (1); 495 } 496 497 int 498 pf_insert_src_node(struct pf_src_node **sn, struct pf_rule *rule, 499 enum pf_sn_types type, sa_family_t af, struct pf_addr *src, 500 struct pf_addr *raddr) 501 { 502 struct pf_src_node k; 503 504 if (*sn == NULL) { 505 k.af = af; 506 k.type = type; 507 PF_ACPY(&k.addr, src, af); 508 k.rule.ptr = rule; 509 pf_status.scounters[SCNT_SRC_NODE_SEARCH]++; 510 *sn = RB_FIND(pf_src_tree, &tree_src_tracking, &k); 511 } 512 if (*sn == NULL) { 513 if (!rule->max_src_nodes || 514 rule->src_nodes < rule->max_src_nodes) 515 (*sn) = pool_get(&pf_src_tree_pl, PR_NOWAIT | PR_ZERO); 516 else 517 pf_status.lcounters[LCNT_SRCNODES]++; 518 if ((*sn) == NULL) 519 return (-1); 520 521 pf_init_threshold(&(*sn)->conn_rate, 522 rule->max_src_conn_rate.limit, 523 rule->max_src_conn_rate.seconds); 524 525 (*sn)->type = type; 526 (*sn)->af = af; 527 (*sn)->rule.ptr = rule; 528 PF_ACPY(&(*sn)->addr, src, af); 529 if (raddr) 530 PF_ACPY(&(*sn)->raddr, raddr, af); 531 if (RB_INSERT(pf_src_tree, 532 &tree_src_tracking, *sn) != NULL) { 533 if (pf_status.debug >= LOG_NOTICE) { 534 log(LOG_NOTICE, 535 "pf: src_tree insert failed: "); 536 pf_print_host(&(*sn)->addr, 0, af); 537 addlog("\n"); 538 } 539 pool_put(&pf_src_tree_pl, *sn); 540 return (-1); 541 } 542 (*sn)->creation = time_uptime; 543 (*sn)->rule.ptr->src_nodes++; 544 pf_status.scounters[SCNT_SRC_NODE_INSERT]++; 545 pf_status.src_nodes++; 546 } else { 547 if (rule->max_src_states && 548 (*sn)->states >= rule->max_src_states) { 549 pf_status.lcounters[LCNT_SRCSTATES]++; 550 return (-1); 551 } 552 } 553 return (0); 554 } 555 556 void 557 pf_remove_src_node(struct pf_src_node *sn) 558 { 559 if (sn->states > 0 || sn->expire > time_uptime) 560 return; 561 562 sn->rule.ptr->src_nodes--; 563 if (sn->rule.ptr->states_cur == 0 && 564 sn->rule.ptr->src_nodes == 0) 565 pf_rm_rule(NULL, sn->rule.ptr); 566 RB_REMOVE(pf_src_tree, &tree_src_tracking, sn); 567 pf_status.scounters[SCNT_SRC_NODE_REMOVALS]++; 568 pf_status.src_nodes--; 569 pool_put(&pf_src_tree_pl, sn); 570 } 571 572 struct pf_src_node * 573 pf_get_src_node(struct pf_state *s, enum pf_sn_types type) 574 { 575 struct pf_sn_item *sni; 576 577 SLIST_FOREACH(sni, &s->src_nodes, next) 578 if (sni->sn->type == type) 579 return (sni->sn); 580 return (NULL); 581 } 582 583 void 584 pf_state_rm_src_node(struct pf_state *s, struct pf_src_node *sn) 585 { 586 struct pf_sn_item *sni, *snin, *snip = NULL; 587 588 for (sni = SLIST_FIRST(&s->src_nodes); sni; sni = snin) { 589 snin = SLIST_NEXT(sni, next); 590 if (sni->sn == sn) { 591 if (snip) 592 SLIST_REMOVE_AFTER(snip, next); 593 else 594 SLIST_REMOVE_HEAD(&s->src_nodes, next); 595 pool_put(&pf_sn_item_pl, sni); 596 sni = NULL; 597 sn->states--; 598 } 599 if (sni != NULL) 600 snip = sni; 601 } 602 } 603 604 /* state table stuff */ 605 606 static __inline int 607 pf_state_compare_key(struct pf_state_key *a, struct pf_state_key *b) 608 { 609 int diff; 610 611 if ((diff = a->proto - b->proto) != 0) 612 return (diff); 613 if ((diff = a->af - b->af) != 0) 614 return (diff); 615 if ((diff = pf_addr_compare(&a->addr[0], &b->addr[0], a->af)) != 0) 616 return (diff); 617 if ((diff = pf_addr_compare(&a->addr[1], &b->addr[1], a->af)) != 0) 618 return (diff); 619 if ((diff = a->port[0] - b->port[0]) != 0) 620 return (diff); 621 if ((diff = a->port[1] - b->port[1]) != 0) 622 return (diff); 623 if ((diff = a->rdomain - b->rdomain) != 0) 624 return (diff); 625 return (0); 626 } 627 628 static __inline int 629 pf_state_compare_id(struct pf_state *a, struct pf_state *b) 630 { 631 if (a->id > b->id) 632 return (1); 633 if (a->id < b->id) 634 return (-1); 635 if (a->creatorid > b->creatorid) 636 return (1); 637 if (a->creatorid < b->creatorid) 638 return (-1); 639 640 return (0); 641 } 642 643 int 644 pf_state_key_attach(struct pf_state_key *sk, struct pf_state *s, int idx) 645 { 646 struct pf_state_item *si; 647 struct pf_state_key *cur; 648 struct pf_state *olds = NULL; 649 650 KASSERT(s->key[idx] == NULL); 651 if ((cur = RB_INSERT(pf_state_tree, &pf_statetbl, sk)) != NULL) { 652 /* key exists. check for same kif, if none, add to key */ 653 TAILQ_FOREACH(si, &cur->states, entry) 654 if (si->s->kif == s->kif && 655 ((si->s->key[PF_SK_WIRE]->af == sk->af && 656 si->s->direction == s->direction) || 657 (si->s->key[PF_SK_WIRE]->af != 658 si->s->key[PF_SK_STACK]->af && 659 sk->af == si->s->key[PF_SK_STACK]->af && 660 si->s->direction != s->direction))) { 661 int reuse = 0; 662 663 if (sk->proto == IPPROTO_TCP && 664 si->s->src.state >= TCPS_FIN_WAIT_2 && 665 si->s->dst.state >= TCPS_FIN_WAIT_2) 666 reuse = 1; 667 if (pf_status.debug >= LOG_NOTICE) { 668 log(LOG_NOTICE, 669 "pf: %s key attach %s on %s: ", 670 (idx == PF_SK_WIRE) ? 671 "wire" : "stack", 672 reuse ? "reuse" : "failed", 673 s->kif->pfik_name); 674 pf_print_state_parts(s, 675 (idx == PF_SK_WIRE) ? sk : NULL, 676 (idx == PF_SK_STACK) ? sk : NULL); 677 addlog(", existing: "); 678 pf_print_state_parts(si->s, 679 (idx == PF_SK_WIRE) ? sk : NULL, 680 (idx == PF_SK_STACK) ? sk : NULL); 681 addlog("\n"); 682 } 683 if (reuse) { 684 si->s->src.state = si->s->dst.state = 685 TCPS_CLOSED; 686 /* remove late or sks can go away */ 687 olds = si->s; 688 } else { 689 pool_put(&pf_state_key_pl, sk); 690 return (-1); /* collision! */ 691 } 692 } 693 pool_put(&pf_state_key_pl, sk); 694 s->key[idx] = cur; 695 } else 696 s->key[idx] = sk; 697 698 if ((si = pool_get(&pf_state_item_pl, PR_NOWAIT)) == NULL) { 699 pf_state_key_detach(s, idx); 700 return (-1); 701 } 702 si->s = s; 703 704 /* list is sorted, if-bound states before floating */ 705 if (s->kif == pfi_all) 706 TAILQ_INSERT_TAIL(&s->key[idx]->states, si, entry); 707 else 708 TAILQ_INSERT_HEAD(&s->key[idx]->states, si, entry); 709 710 if (olds) 711 pf_remove_state(olds); 712 713 return (0); 714 } 715 716 void 717 pf_detach_state(struct pf_state *s) 718 { 719 if (s->key[PF_SK_WIRE] == s->key[PF_SK_STACK]) 720 s->key[PF_SK_WIRE] = NULL; 721 722 if (s->key[PF_SK_STACK] != NULL) 723 pf_state_key_detach(s, PF_SK_STACK); 724 725 if (s->key[PF_SK_WIRE] != NULL) 726 pf_state_key_detach(s, PF_SK_WIRE); 727 } 728 729 void 730 pf_state_key_detach(struct pf_state *s, int idx) 731 { 732 struct pf_state_item *si; 733 struct pf_state_key *sk; 734 735 if (s->key[idx] == NULL) 736 return; 737 738 si = TAILQ_FIRST(&s->key[idx]->states); 739 while (si && si->s != s) 740 si = TAILQ_NEXT(si, entry); 741 742 if (si) { 743 TAILQ_REMOVE(&s->key[idx]->states, si, entry); 744 pool_put(&pf_state_item_pl, si); 745 } 746 747 sk = s->key[idx]; 748 s->key[idx] = NULL; 749 if (TAILQ_EMPTY(&sk->states)) { 750 RB_REMOVE(pf_state_tree, &pf_statetbl, sk); 751 sk->removed = 1; 752 pf_state_key_unlink_reverse(sk); 753 pf_inpcb_unlink_state_key(sk->inp); 754 pf_state_key_unref(sk); 755 } 756 } 757 758 struct pf_state_key * 759 pf_alloc_state_key(int pool_flags) 760 { 761 struct pf_state_key *sk; 762 763 if ((sk = pool_get(&pf_state_key_pl, pool_flags)) == NULL) 764 return (NULL); 765 TAILQ_INIT(&sk->states); 766 767 return (sk); 768 } 769 770 static __inline int 771 pf_state_key_addr_setup(struct pf_pdesc *pd, void *arg, int sidx, 772 struct pf_addr *saddr, int didx, struct pf_addr *daddr, int af, int multi) 773 { 774 struct pf_state_key_cmp *key = arg; 775 #ifdef INET6 776 struct pf_addr *target; 777 778 if (af == AF_INET || pd->proto != IPPROTO_ICMPV6) 779 goto copy; 780 781 switch (pd->hdr.icmp6.icmp6_type) { 782 case ND_NEIGHBOR_SOLICIT: 783 if (multi) 784 return (-1); 785 target = (struct pf_addr *)&pd->hdr.nd_ns.nd_ns_target; 786 daddr = target; 787 break; 788 case ND_NEIGHBOR_ADVERT: 789 if (multi) 790 return (-1); 791 target = (struct pf_addr *)&pd->hdr.nd_ns.nd_ns_target; 792 saddr = target; 793 if (IN6_IS_ADDR_MULTICAST(&pd->dst->v6)) { 794 key->addr[didx].addr32[0] = 0; 795 key->addr[didx].addr32[1] = 0; 796 key->addr[didx].addr32[2] = 0; 797 key->addr[didx].addr32[3] = 0; 798 daddr = NULL; /* overwritten */ 799 } 800 break; 801 default: 802 if (multi) { 803 key->addr[sidx].addr32[0] = __IPV6_ADDR_INT32_MLL; 804 key->addr[sidx].addr32[1] = 0; 805 key->addr[sidx].addr32[2] = 0; 806 key->addr[sidx].addr32[3] = __IPV6_ADDR_INT32_ONE; 807 saddr = NULL; /* overwritten */ 808 } 809 } 810 copy: 811 #endif /* INET6 */ 812 if (saddr) 813 PF_ACPY(&key->addr[sidx], saddr, af); 814 if (daddr) 815 PF_ACPY(&key->addr[didx], daddr, af); 816 817 return (0); 818 } 819 820 int 821 pf_state_key_setup(struct pf_pdesc *pd, struct pf_state_key **skw, 822 struct pf_state_key **sks, int rtableid) 823 { 824 /* if returning error we MUST pool_put state keys ourselves */ 825 struct pf_state_key *sk1, *sk2; 826 u_int wrdom = pd->rdomain; 827 int afto = pd->af != pd->naf; 828 829 if ((sk1 = pf_alloc_state_key(PR_NOWAIT | PR_ZERO)) == NULL) 830 return (ENOMEM); 831 832 pf_state_key_addr_setup(pd, sk1, pd->sidx, pd->src, pd->didx, pd->dst, 833 pd->af, 0); 834 sk1->port[pd->sidx] = pd->osport; 835 sk1->port[pd->didx] = pd->odport; 836 sk1->proto = pd->proto; 837 sk1->af = pd->af; 838 sk1->rdomain = pd->rdomain; 839 PF_REF_INIT(sk1->refcnt); 840 sk1->removed = 0; 841 if (rtableid >= 0) 842 wrdom = rtable_l2(rtableid); 843 844 if (PF_ANEQ(&pd->nsaddr, pd->src, pd->af) || 845 PF_ANEQ(&pd->ndaddr, pd->dst, pd->af) || 846 pd->nsport != pd->osport || pd->ndport != pd->odport || 847 wrdom != pd->rdomain || afto) { /* NAT/NAT64 */ 848 if ((sk2 = pf_alloc_state_key(PR_NOWAIT | PR_ZERO)) == NULL) { 849 pool_put(&pf_state_key_pl, sk1); 850 return (ENOMEM); 851 } 852 pf_state_key_addr_setup(pd, sk2, afto ? pd->didx : pd->sidx, 853 &pd->nsaddr, afto ? pd->sidx : pd->didx, &pd->ndaddr, 854 pd->naf, 0); 855 sk2->port[afto ? pd->didx : pd->sidx] = pd->nsport; 856 sk2->port[afto ? pd->sidx : pd->didx] = pd->ndport; 857 if (afto) { 858 switch (pd->proto) { 859 case IPPROTO_ICMP: 860 sk2->proto = IPPROTO_ICMPV6; 861 break; 862 case IPPROTO_ICMPV6: 863 sk2->proto = IPPROTO_ICMP; 864 break; 865 default: 866 sk2->proto = pd->proto; 867 } 868 } else 869 sk2->proto = pd->proto; 870 sk2->af = pd->naf; 871 sk2->rdomain = wrdom; 872 PF_REF_INIT(sk2->refcnt); 873 sk2->removed = 0; 874 } else 875 sk2 = sk1; 876 877 if (pd->dir == PF_IN) { 878 *skw = sk1; 879 *sks = sk2; 880 } else { 881 *sks = sk1; 882 *skw = sk2; 883 } 884 885 if (pf_status.debug >= LOG_DEBUG) { 886 log(LOG_DEBUG, "pf: key setup: "); 887 pf_print_state_parts(NULL, *skw, *sks); 888 addlog("\n"); 889 } 890 891 return (0); 892 } 893 894 int 895 pf_state_insert(struct pfi_kif *kif, struct pf_state_key **skw, 896 struct pf_state_key **sks, struct pf_state *s) 897 { 898 splsoftassert(IPL_SOFTNET); 899 900 s->kif = kif; 901 if (*skw == *sks) { 902 if (pf_state_key_attach(*skw, s, PF_SK_WIRE)) 903 return (-1); 904 *skw = *sks = s->key[PF_SK_WIRE]; 905 s->key[PF_SK_STACK] = s->key[PF_SK_WIRE]; 906 } else { 907 if (pf_state_key_attach(*skw, s, PF_SK_WIRE)) { 908 pool_put(&pf_state_key_pl, *sks); 909 return (-1); 910 } 911 *skw = s->key[PF_SK_WIRE]; 912 if (pf_state_key_attach(*sks, s, PF_SK_STACK)) { 913 pf_state_key_detach(s, PF_SK_WIRE); 914 return (-1); 915 } 916 *sks = s->key[PF_SK_STACK]; 917 } 918 919 if (s->id == 0 && s->creatorid == 0) { 920 s->id = htobe64(pf_status.stateid++); 921 s->creatorid = pf_status.hostid; 922 } 923 if (RB_INSERT(pf_state_tree_id, &tree_id, s) != NULL) { 924 if (pf_status.debug >= LOG_NOTICE) { 925 log(LOG_NOTICE, "pf: state insert failed: " 926 "id: %016llx creatorid: %08x", 927 betoh64(s->id), ntohl(s->creatorid)); 928 addlog("\n"); 929 } 930 pf_detach_state(s); 931 return (-1); 932 } 933 TAILQ_INSERT_TAIL(&state_list, s, entry_list); 934 pf_status.fcounters[FCNT_STATE_INSERT]++; 935 pf_status.states++; 936 pfi_kif_ref(kif, PFI_KIF_REF_STATE); 937 #if NPFSYNC > 0 938 pfsync_insert_state(s); 939 #endif /* NPFSYNC > 0 */ 940 return (0); 941 } 942 943 struct pf_state * 944 pf_find_state_byid(struct pf_state_cmp *key) 945 { 946 pf_status.fcounters[FCNT_STATE_SEARCH]++; 947 948 return (RB_FIND(pf_state_tree_id, &tree_id, (struct pf_state *)key)); 949 } 950 951 int 952 pf_compare_state_keys(struct pf_state_key *a, struct pf_state_key *b, 953 struct pfi_kif *kif, u_int dir) 954 { 955 /* a (from hdr) and b (new) must be exact opposites of each other */ 956 if (a->af == b->af && a->proto == b->proto && 957 PF_AEQ(&a->addr[0], &b->addr[1], a->af) && 958 PF_AEQ(&a->addr[1], &b->addr[0], a->af) && 959 a->port[0] == b->port[1] && 960 a->port[1] == b->port[0] && a->rdomain == b->rdomain) 961 return (0); 962 else { 963 /* mismatch. must not happen. */ 964 if (pf_status.debug >= LOG_ERR) { 965 log(LOG_ERR, 966 "pf: state key linking mismatch! dir=%s, " 967 "if=%s, stored af=%u, a0: ", 968 dir == PF_OUT ? "OUT" : "IN", 969 kif->pfik_name, a->af); 970 pf_print_host(&a->addr[0], a->port[0], a->af); 971 addlog(", a1: "); 972 pf_print_host(&a->addr[1], a->port[1], a->af); 973 addlog(", proto=%u", a->proto); 974 addlog(", found af=%u, a0: ", b->af); 975 pf_print_host(&b->addr[0], b->port[0], b->af); 976 addlog(", a1: "); 977 pf_print_host(&b->addr[1], b->port[1], b->af); 978 addlog(", proto=%u", b->proto); 979 addlog("\n"); 980 } 981 return (-1); 982 } 983 } 984 985 struct pf_state * 986 pf_find_state(struct pfi_kif *kif, struct pf_state_key_cmp *key, u_int dir, 987 struct mbuf *m) 988 { 989 struct pf_state_key *sk, *pkt_sk, *inp_sk; 990 struct pf_state_item *si; 991 992 pf_status.fcounters[FCNT_STATE_SEARCH]++; 993 if (pf_status.debug >= LOG_DEBUG) { 994 log(LOG_DEBUG, "pf: key search, if=%s: ", kif->pfik_name); 995 pf_print_state_parts(NULL, (struct pf_state_key *)key, NULL); 996 addlog("\n"); 997 } 998 999 inp_sk = NULL; 1000 pkt_sk = NULL; 1001 sk = NULL; 1002 if (dir == PF_OUT) { 1003 /* first if block deals with outbound forwarded packet */ 1004 pkt_sk = m->m_pkthdr.pf.statekey; 1005 1006 if (!pf_state_key_isvalid(pkt_sk)) { 1007 pf_pkt_unlink_state_key(m); 1008 pkt_sk = NULL; 1009 } 1010 1011 if (pkt_sk && pf_state_key_isvalid(pkt_sk->reverse)) 1012 sk = pkt_sk->reverse; 1013 1014 if (pkt_sk == NULL) { 1015 /* here we deal with local outbound packet */ 1016 if (m->m_pkthdr.pf.inp != NULL) { 1017 inp_sk = m->m_pkthdr.pf.inp->inp_pf_sk; 1018 if (pf_state_key_isvalid(inp_sk)) 1019 sk = inp_sk; 1020 else 1021 pf_inpcb_unlink_state_key( 1022 m->m_pkthdr.pf.inp); 1023 } 1024 } 1025 } 1026 1027 if (sk == NULL) { 1028 if ((sk = RB_FIND(pf_state_tree, &pf_statetbl, 1029 (struct pf_state_key *)key)) == NULL) 1030 return (NULL); 1031 if (dir == PF_OUT && pkt_sk && 1032 pf_compare_state_keys(pkt_sk, sk, kif, dir) == 0) 1033 pf_state_key_link(sk, pkt_sk); 1034 else if (dir == PF_OUT) 1035 pf_inp_link(m, m->m_pkthdr.pf.inp); 1036 } 1037 1038 /* remove firewall data from outbound packet */ 1039 if (dir == PF_OUT) 1040 pf_pkt_addr_changed(m); 1041 1042 /* list is sorted, if-bound states before floating ones */ 1043 TAILQ_FOREACH(si, &sk->states, entry) 1044 if ((si->s->kif == pfi_all || si->s->kif == kif) && 1045 ((si->s->key[PF_SK_WIRE]->af == si->s->key[PF_SK_STACK]->af 1046 && sk == (dir == PF_IN ? si->s->key[PF_SK_WIRE] : 1047 si->s->key[PF_SK_STACK])) || 1048 (si->s->key[PF_SK_WIRE]->af != si->s->key[PF_SK_STACK]->af 1049 && dir == PF_IN && (sk == si->s->key[PF_SK_STACK] || 1050 sk == si->s->key[PF_SK_WIRE])))) 1051 return (si->s); 1052 1053 return (NULL); 1054 } 1055 1056 struct pf_state * 1057 pf_find_state_all(struct pf_state_key_cmp *key, u_int dir, int *more) 1058 { 1059 struct pf_state_key *sk; 1060 struct pf_state_item *si, *ret = NULL; 1061 1062 pf_status.fcounters[FCNT_STATE_SEARCH]++; 1063 1064 sk = RB_FIND(pf_state_tree, &pf_statetbl, (struct pf_state_key *)key); 1065 1066 if (sk != NULL) { 1067 TAILQ_FOREACH(si, &sk->states, entry) 1068 if (dir == PF_INOUT || 1069 (sk == (dir == PF_IN ? si->s->key[PF_SK_WIRE] : 1070 si->s->key[PF_SK_STACK]))) { 1071 if (more == NULL) 1072 return (si->s); 1073 1074 if (ret) 1075 (*more)++; 1076 else 1077 ret = si; 1078 } 1079 } 1080 return (ret ? ret->s : NULL); 1081 } 1082 1083 void 1084 pf_state_export(struct pfsync_state *sp, struct pf_state *st) 1085 { 1086 int32_t expire; 1087 1088 bzero(sp, sizeof(struct pfsync_state)); 1089 1090 /* copy from state key */ 1091 sp->key[PF_SK_WIRE].addr[0] = st->key[PF_SK_WIRE]->addr[0]; 1092 sp->key[PF_SK_WIRE].addr[1] = st->key[PF_SK_WIRE]->addr[1]; 1093 sp->key[PF_SK_WIRE].port[0] = st->key[PF_SK_WIRE]->port[0]; 1094 sp->key[PF_SK_WIRE].port[1] = st->key[PF_SK_WIRE]->port[1]; 1095 sp->key[PF_SK_WIRE].rdomain = htons(st->key[PF_SK_WIRE]->rdomain); 1096 sp->key[PF_SK_WIRE].af = st->key[PF_SK_WIRE]->af; 1097 sp->key[PF_SK_STACK].addr[0] = st->key[PF_SK_STACK]->addr[0]; 1098 sp->key[PF_SK_STACK].addr[1] = st->key[PF_SK_STACK]->addr[1]; 1099 sp->key[PF_SK_STACK].port[0] = st->key[PF_SK_STACK]->port[0]; 1100 sp->key[PF_SK_STACK].port[1] = st->key[PF_SK_STACK]->port[1]; 1101 sp->key[PF_SK_STACK].rdomain = htons(st->key[PF_SK_STACK]->rdomain); 1102 sp->key[PF_SK_STACK].af = st->key[PF_SK_STACK]->af; 1103 sp->rtableid[PF_SK_WIRE] = htonl(st->rtableid[PF_SK_WIRE]); 1104 sp->rtableid[PF_SK_STACK] = htonl(st->rtableid[PF_SK_STACK]); 1105 sp->proto = st->key[PF_SK_WIRE]->proto; 1106 sp->af = st->key[PF_SK_WIRE]->af; 1107 1108 /* copy from state */ 1109 strlcpy(sp->ifname, st->kif->pfik_name, sizeof(sp->ifname)); 1110 memcpy(&sp->rt_addr, &st->rt_addr, sizeof(sp->rt_addr)); 1111 sp->creation = htonl(time_uptime - st->creation); 1112 expire = pf_state_expires(st); 1113 if (expire <= time_uptime) 1114 sp->expire = htonl(0); 1115 else 1116 sp->expire = htonl(expire - time_uptime); 1117 1118 sp->direction = st->direction; 1119 #if NPFLOG > 0 1120 sp->log = st->log; 1121 #endif /* NPFLOG > 0 */ 1122 sp->timeout = st->timeout; 1123 sp->state_flags = htons(st->state_flags); 1124 if (!SLIST_EMPTY(&st->src_nodes)) 1125 sp->sync_flags |= PFSYNC_FLAG_SRCNODE; 1126 1127 sp->id = st->id; 1128 sp->creatorid = st->creatorid; 1129 pf_state_peer_hton(&st->src, &sp->src); 1130 pf_state_peer_hton(&st->dst, &sp->dst); 1131 1132 if (st->rule.ptr == NULL) 1133 sp->rule = htonl(-1); 1134 else 1135 sp->rule = htonl(st->rule.ptr->nr); 1136 if (st->anchor.ptr == NULL) 1137 sp->anchor = htonl(-1); 1138 else 1139 sp->anchor = htonl(st->anchor.ptr->nr); 1140 sp->nat_rule = htonl(-1); /* left for compat, nat_rule is gone */ 1141 1142 pf_state_counter_hton(st->packets[0], sp->packets[0]); 1143 pf_state_counter_hton(st->packets[1], sp->packets[1]); 1144 pf_state_counter_hton(st->bytes[0], sp->bytes[0]); 1145 pf_state_counter_hton(st->bytes[1], sp->bytes[1]); 1146 1147 sp->max_mss = htons(st->max_mss); 1148 sp->min_ttl = st->min_ttl; 1149 sp->set_tos = st->set_tos; 1150 sp->set_prio[0] = st->set_prio[0]; 1151 sp->set_prio[1] = st->set_prio[1]; 1152 } 1153 1154 /* END state table stuff */ 1155 1156 void 1157 pf_purge_expired_rules(void) 1158 { 1159 struct pf_rule *r; 1160 1161 NET_ASSERT_LOCKED(); 1162 1163 if (SLIST_EMPTY(&pf_rule_gcl)) 1164 return; 1165 1166 while ((r = SLIST_FIRST(&pf_rule_gcl)) != NULL) { 1167 SLIST_REMOVE(&pf_rule_gcl, r, pf_rule, gcle); 1168 KASSERT(r->rule_flag & PFRULE_EXPIRED); 1169 pf_purge_rule(r); 1170 } 1171 } 1172 1173 void 1174 pf_purge_thread(void *v) 1175 { 1176 int nloops = 0, s; 1177 1178 for (;;) { 1179 tsleep(pf_purge_thread, PWAIT, "pftm", 1 * hz); 1180 1181 NET_LOCK(s); 1182 1183 /* process a fraction of the state table every second */ 1184 pf_purge_expired_states(1 + (pf_status.states 1185 / pf_default_rule.timeout[PFTM_INTERVAL])); 1186 1187 /* purge other expired types every PFTM_INTERVAL seconds */ 1188 if (++nloops >= pf_default_rule.timeout[PFTM_INTERVAL]) { 1189 pf_purge_expired_fragments(); 1190 pf_purge_expired_src_nodes(0); 1191 pf_purge_expired_rules(); 1192 nloops = 0; 1193 } 1194 1195 NET_UNLOCK(s); 1196 } 1197 } 1198 1199 int32_t 1200 pf_state_expires(const struct pf_state *state) 1201 { 1202 int32_t timeout; 1203 u_int32_t start; 1204 u_int32_t end; 1205 u_int32_t states; 1206 1207 /* handle all PFTM_* > PFTM_MAX here */ 1208 if (state->timeout == PFTM_PURGE) 1209 return (0); 1210 1211 KASSERT(state->timeout != PFTM_UNLINKED); 1212 KASSERT(state->timeout < PFTM_MAX); 1213 1214 timeout = state->rule.ptr->timeout[state->timeout]; 1215 if (!timeout) 1216 timeout = pf_default_rule.timeout[state->timeout]; 1217 1218 start = state->rule.ptr->timeout[PFTM_ADAPTIVE_START]; 1219 if (start) { 1220 end = state->rule.ptr->timeout[PFTM_ADAPTIVE_END]; 1221 states = state->rule.ptr->states_cur; 1222 } else { 1223 start = pf_default_rule.timeout[PFTM_ADAPTIVE_START]; 1224 end = pf_default_rule.timeout[PFTM_ADAPTIVE_END]; 1225 states = pf_status.states; 1226 } 1227 if (end && states > start && start < end) { 1228 if (states >= end) 1229 return (0); 1230 1231 timeout = timeout * (end - states) / (end - start); 1232 } 1233 1234 return (state->expire + timeout); 1235 } 1236 1237 void 1238 pf_purge_expired_src_nodes(void) 1239 { 1240 struct pf_src_node *cur, *next; 1241 1242 NET_ASSERT_LOCKED(); 1243 1244 for (cur = RB_MIN(pf_src_tree, &tree_src_tracking); cur; cur = next) { 1245 next = RB_NEXT(pf_src_tree, &tree_src_tracking, cur); 1246 1247 if (cur->states == 0 && cur->expire <= time_uptime) { 1248 next = RB_NEXT(pf_src_tree, &tree_src_tracking, cur); 1249 pf_remove_src_node(cur); 1250 } 1251 } 1252 } 1253 1254 void 1255 pf_src_tree_remove_state(struct pf_state *s) 1256 { 1257 u_int32_t timeout; 1258 struct pf_sn_item *sni; 1259 1260 while ((sni = SLIST_FIRST(&s->src_nodes)) != NULL) { 1261 SLIST_REMOVE_HEAD(&s->src_nodes, next); 1262 if (s->src.tcp_est) 1263 --sni->sn->conn; 1264 if (--sni->sn->states == 0) { 1265 timeout = s->rule.ptr->timeout[PFTM_SRC_NODE]; 1266 if (!timeout) 1267 timeout = 1268 pf_default_rule.timeout[PFTM_SRC_NODE]; 1269 sni->sn->expire = time_uptime + timeout; 1270 } 1271 pool_put(&pf_sn_item_pl, sni); 1272 } 1273 } 1274 1275 void 1276 pf_remove_state(struct pf_state *cur) 1277 { 1278 splsoftassert(IPL_SOFTNET); 1279 1280 /* handle load balancing related tasks */ 1281 pf_postprocess_addr(cur); 1282 1283 if (cur->src.state == PF_TCPS_PROXY_DST) { 1284 pf_send_tcp(cur->rule.ptr, cur->key[PF_SK_WIRE]->af, 1285 &cur->key[PF_SK_WIRE]->addr[1], 1286 &cur->key[PF_SK_WIRE]->addr[0], 1287 cur->key[PF_SK_WIRE]->port[1], 1288 cur->key[PF_SK_WIRE]->port[0], 1289 cur->src.seqhi, cur->src.seqlo + 1, 1290 TH_RST|TH_ACK, 0, 0, 0, 1, cur->tag, 1291 cur->key[PF_SK_WIRE]->rdomain); 1292 } 1293 RB_REMOVE(pf_state_tree_id, &tree_id, cur); 1294 #if NPFLOW > 0 1295 if (cur->state_flags & PFSTATE_PFLOW) { 1296 /* XXXSMP breaks atomicity */ 1297 rw_exit_write(&netlock); 1298 export_pflow(cur); 1299 rw_enter_write(&netlock); 1300 } 1301 #endif /* NPFLOW > 0 */ 1302 #if NPFSYNC > 0 1303 pfsync_delete_state(cur); 1304 #endif /* NPFSYNC > 0 */ 1305 cur->timeout = PFTM_UNLINKED; 1306 pf_src_tree_remove_state(cur); 1307 pf_detach_state(cur); 1308 } 1309 1310 void 1311 pf_remove_divert_state(struct pf_state_key *sk) 1312 { 1313 struct pf_state_item *si; 1314 1315 TAILQ_FOREACH(si, &sk->states, entry) { 1316 if (sk == si->s->key[PF_SK_STACK] && si->s->rule.ptr && 1317 si->s->rule.ptr->divert.port) { 1318 pf_remove_state(si->s); 1319 break; 1320 } 1321 } 1322 } 1323 1324 void 1325 pf_free_state(struct pf_state *cur) 1326 { 1327 struct pf_rule_item *ri; 1328 1329 NET_ASSERT_LOCKED(); 1330 1331 #if NPFSYNC > 0 1332 if (pfsync_state_in_use(cur)) 1333 return; 1334 #endif /* NPFSYNC > 0 */ 1335 KASSERT(cur->timeout == PFTM_UNLINKED); 1336 if (--cur->rule.ptr->states_cur == 0 && 1337 cur->rule.ptr->src_nodes == 0) 1338 pf_rm_rule(NULL, cur->rule.ptr); 1339 if (cur->anchor.ptr != NULL) 1340 if (--cur->anchor.ptr->states_cur == 0) 1341 pf_rm_rule(NULL, cur->anchor.ptr); 1342 while ((ri = SLIST_FIRST(&cur->match_rules))) { 1343 SLIST_REMOVE_HEAD(&cur->match_rules, entry); 1344 if (--ri->r->states_cur == 0 && 1345 ri->r->src_nodes == 0) 1346 pf_rm_rule(NULL, ri->r); 1347 pool_put(&pf_rule_item_pl, ri); 1348 } 1349 pf_normalize_tcp_cleanup(cur); 1350 pfi_kif_unref(cur->kif, PFI_KIF_REF_STATE); 1351 TAILQ_REMOVE(&state_list, cur, entry_list); 1352 if (cur->tag) 1353 pf_tag_unref(cur->tag); 1354 pool_put(&pf_state_pl, cur); 1355 pf_status.fcounters[FCNT_STATE_REMOVALS]++; 1356 pf_status.states--; 1357 } 1358 1359 void 1360 pf_purge_expired_states(u_int32_t maxcheck) 1361 { 1362 static struct pf_state *cur = NULL; 1363 struct pf_state *next; 1364 1365 NET_ASSERT_LOCKED(); 1366 1367 while (maxcheck--) { 1368 /* wrap to start of list when we hit the end */ 1369 if (cur == NULL) { 1370 cur = TAILQ_FIRST(&state_list); 1371 if (cur == NULL) 1372 break; /* list empty */ 1373 } 1374 1375 /* get next state, as cur may get deleted */ 1376 next = TAILQ_NEXT(cur, entry_list); 1377 1378 if (cur->timeout == PFTM_UNLINKED) { 1379 /* free removed state */ 1380 pf_free_state(cur); 1381 } else if (pf_state_expires(cur) <= time_uptime) { 1382 /* remove and free expired state */ 1383 pf_remove_state(cur); 1384 pf_free_state(cur); 1385 } 1386 cur = next; 1387 } 1388 } 1389 1390 int 1391 pf_tbladdr_setup(struct pf_ruleset *rs, struct pf_addr_wrap *aw) 1392 { 1393 if (aw->type != PF_ADDR_TABLE) 1394 return (0); 1395 if ((aw->p.tbl = pfr_attach_table(rs, aw->v.tblname, 1)) == NULL) 1396 return (1); 1397 return (0); 1398 } 1399 1400 void 1401 pf_tbladdr_remove(struct pf_addr_wrap *aw) 1402 { 1403 if (aw->type != PF_ADDR_TABLE || aw->p.tbl == NULL) 1404 return; 1405 pfr_detach_table(aw->p.tbl); 1406 aw->p.tbl = NULL; 1407 } 1408 1409 void 1410 pf_tbladdr_copyout(struct pf_addr_wrap *aw) 1411 { 1412 struct pfr_ktable *kt = aw->p.tbl; 1413 1414 if (aw->type != PF_ADDR_TABLE || kt == NULL) 1415 return; 1416 if (!(kt->pfrkt_flags & PFR_TFLAG_ACTIVE) && kt->pfrkt_root != NULL) 1417 kt = kt->pfrkt_root; 1418 aw->p.tbl = NULL; 1419 aw->p.tblcnt = (kt->pfrkt_flags & PFR_TFLAG_ACTIVE) ? 1420 kt->pfrkt_cnt : -1; 1421 } 1422 1423 void 1424 pf_print_host(struct pf_addr *addr, u_int16_t p, sa_family_t af) 1425 { 1426 switch (af) { 1427 case AF_INET: { 1428 u_int32_t a = ntohl(addr->addr32[0]); 1429 addlog("%u.%u.%u.%u", (a>>24)&255, (a>>16)&255, 1430 (a>>8)&255, a&255); 1431 if (p) { 1432 p = ntohs(p); 1433 addlog(":%u", p); 1434 } 1435 break; 1436 } 1437 #ifdef INET6 1438 case AF_INET6: { 1439 u_int16_t b; 1440 u_int8_t i, curstart, curend, maxstart, maxend; 1441 curstart = curend = maxstart = maxend = 255; 1442 for (i = 0; i < 8; i++) { 1443 if (!addr->addr16[i]) { 1444 if (curstart == 255) 1445 curstart = i; 1446 curend = i; 1447 } else { 1448 if ((curend - curstart) > 1449 (maxend - maxstart)) { 1450 maxstart = curstart; 1451 maxend = curend; 1452 } 1453 curstart = curend = 255; 1454 } 1455 } 1456 if ((curend - curstart) > 1457 (maxend - maxstart)) { 1458 maxstart = curstart; 1459 maxend = curend; 1460 } 1461 for (i = 0; i < 8; i++) { 1462 if (i >= maxstart && i <= maxend) { 1463 if (i == 0) 1464 addlog(":"); 1465 if (i == maxend) 1466 addlog(":"); 1467 } else { 1468 b = ntohs(addr->addr16[i]); 1469 addlog("%x", b); 1470 if (i < 7) 1471 addlog(":"); 1472 } 1473 } 1474 if (p) { 1475 p = ntohs(p); 1476 addlog("[%u]", p); 1477 } 1478 break; 1479 } 1480 #endif /* INET6 */ 1481 } 1482 } 1483 1484 void 1485 pf_print_state(struct pf_state *s) 1486 { 1487 pf_print_state_parts(s, NULL, NULL); 1488 } 1489 1490 void 1491 pf_print_state_parts(struct pf_state *s, 1492 struct pf_state_key *skwp, struct pf_state_key *sksp) 1493 { 1494 struct pf_state_key *skw, *sks; 1495 u_int8_t proto, dir; 1496 1497 /* Do our best to fill these, but they're skipped if NULL */ 1498 skw = skwp ? skwp : (s ? s->key[PF_SK_WIRE] : NULL); 1499 sks = sksp ? sksp : (s ? s->key[PF_SK_STACK] : NULL); 1500 proto = skw ? skw->proto : (sks ? sks->proto : 0); 1501 dir = s ? s->direction : 0; 1502 1503 switch (proto) { 1504 case IPPROTO_IPV4: 1505 addlog("IPv4"); 1506 break; 1507 case IPPROTO_IPV6: 1508 addlog("IPv6"); 1509 break; 1510 case IPPROTO_TCP: 1511 addlog("TCP"); 1512 break; 1513 case IPPROTO_UDP: 1514 addlog("UDP"); 1515 break; 1516 case IPPROTO_ICMP: 1517 addlog("ICMP"); 1518 break; 1519 case IPPROTO_ICMPV6: 1520 addlog("ICMPv6"); 1521 break; 1522 default: 1523 addlog("%u", proto); 1524 break; 1525 } 1526 switch (dir) { 1527 case PF_IN: 1528 addlog(" in"); 1529 break; 1530 case PF_OUT: 1531 addlog(" out"); 1532 break; 1533 } 1534 if (skw) { 1535 addlog(" wire: (%d) ", skw->rdomain); 1536 pf_print_host(&skw->addr[0], skw->port[0], skw->af); 1537 addlog(" "); 1538 pf_print_host(&skw->addr[1], skw->port[1], skw->af); 1539 } 1540 if (sks) { 1541 addlog(" stack: (%d) ", sks->rdomain); 1542 if (sks != skw) { 1543 pf_print_host(&sks->addr[0], sks->port[0], sks->af); 1544 addlog(" "); 1545 pf_print_host(&sks->addr[1], sks->port[1], sks->af); 1546 } else 1547 addlog("-"); 1548 } 1549 if (s) { 1550 if (proto == IPPROTO_TCP) { 1551 addlog(" [lo=%u high=%u win=%u modulator=%u", 1552 s->src.seqlo, s->src.seqhi, 1553 s->src.max_win, s->src.seqdiff); 1554 if (s->src.wscale && s->dst.wscale) 1555 addlog(" wscale=%u", 1556 s->src.wscale & PF_WSCALE_MASK); 1557 addlog("]"); 1558 addlog(" [lo=%u high=%u win=%u modulator=%u", 1559 s->dst.seqlo, s->dst.seqhi, 1560 s->dst.max_win, s->dst.seqdiff); 1561 if (s->src.wscale && s->dst.wscale) 1562 addlog(" wscale=%u", 1563 s->dst.wscale & PF_WSCALE_MASK); 1564 addlog("]"); 1565 } 1566 addlog(" %u:%u", s->src.state, s->dst.state); 1567 if (s->rule.ptr) 1568 addlog(" @%d", s->rule.ptr->nr); 1569 } 1570 } 1571 1572 void 1573 pf_print_flags(u_int8_t f) 1574 { 1575 if (f) 1576 addlog(" "); 1577 if (f & TH_FIN) 1578 addlog("F"); 1579 if (f & TH_SYN) 1580 addlog("S"); 1581 if (f & TH_RST) 1582 addlog("R"); 1583 if (f & TH_PUSH) 1584 addlog("P"); 1585 if (f & TH_ACK) 1586 addlog("A"); 1587 if (f & TH_URG) 1588 addlog("U"); 1589 if (f & TH_ECE) 1590 addlog("E"); 1591 if (f & TH_CWR) 1592 addlog("W"); 1593 } 1594 1595 #define PF_SET_SKIP_STEPS(i) \ 1596 do { \ 1597 while (head[i] != cur) { \ 1598 head[i]->skip[i].ptr = cur; \ 1599 head[i] = TAILQ_NEXT(head[i], entries); \ 1600 } \ 1601 } while (0) 1602 1603 void 1604 pf_calc_skip_steps(struct pf_rulequeue *rules) 1605 { 1606 struct pf_rule *cur, *prev, *head[PF_SKIP_COUNT]; 1607 int i; 1608 1609 cur = TAILQ_FIRST(rules); 1610 prev = cur; 1611 for (i = 0; i < PF_SKIP_COUNT; ++i) 1612 head[i] = cur; 1613 while (cur != NULL) { 1614 if (cur->kif != prev->kif || cur->ifnot != prev->ifnot) 1615 PF_SET_SKIP_STEPS(PF_SKIP_IFP); 1616 if (cur->direction != prev->direction) 1617 PF_SET_SKIP_STEPS(PF_SKIP_DIR); 1618 if (cur->onrdomain != prev->onrdomain || 1619 cur->ifnot != prev->ifnot) 1620 PF_SET_SKIP_STEPS(PF_SKIP_RDOM); 1621 if (cur->af != prev->af) 1622 PF_SET_SKIP_STEPS(PF_SKIP_AF); 1623 if (cur->proto != prev->proto) 1624 PF_SET_SKIP_STEPS(PF_SKIP_PROTO); 1625 if (cur->src.neg != prev->src.neg || 1626 pf_addr_wrap_neq(&cur->src.addr, &prev->src.addr)) 1627 PF_SET_SKIP_STEPS(PF_SKIP_SRC_ADDR); 1628 if (cur->dst.neg != prev->dst.neg || 1629 pf_addr_wrap_neq(&cur->dst.addr, &prev->dst.addr)) 1630 PF_SET_SKIP_STEPS(PF_SKIP_DST_ADDR); 1631 if (cur->src.port[0] != prev->src.port[0] || 1632 cur->src.port[1] != prev->src.port[1] || 1633 cur->src.port_op != prev->src.port_op) 1634 PF_SET_SKIP_STEPS(PF_SKIP_SRC_PORT); 1635 if (cur->dst.port[0] != prev->dst.port[0] || 1636 cur->dst.port[1] != prev->dst.port[1] || 1637 cur->dst.port_op != prev->dst.port_op) 1638 PF_SET_SKIP_STEPS(PF_SKIP_DST_PORT); 1639 1640 prev = cur; 1641 cur = TAILQ_NEXT(cur, entries); 1642 } 1643 for (i = 0; i < PF_SKIP_COUNT; ++i) 1644 PF_SET_SKIP_STEPS(i); 1645 } 1646 1647 int 1648 pf_addr_wrap_neq(struct pf_addr_wrap *aw1, struct pf_addr_wrap *aw2) 1649 { 1650 if (aw1->type != aw2->type) 1651 return (1); 1652 switch (aw1->type) { 1653 case PF_ADDR_ADDRMASK: 1654 case PF_ADDR_RANGE: 1655 if (PF_ANEQ(&aw1->v.a.addr, &aw2->v.a.addr, AF_INET6)) 1656 return (1); 1657 if (PF_ANEQ(&aw1->v.a.mask, &aw2->v.a.mask, AF_INET6)) 1658 return (1); 1659 return (0); 1660 case PF_ADDR_DYNIFTL: 1661 return (aw1->p.dyn->pfid_kt != aw2->p.dyn->pfid_kt); 1662 case PF_ADDR_NONE: 1663 case PF_ADDR_NOROUTE: 1664 case PF_ADDR_URPFFAILED: 1665 return (0); 1666 case PF_ADDR_TABLE: 1667 return (aw1->p.tbl != aw2->p.tbl); 1668 case PF_ADDR_RTLABEL: 1669 return (aw1->v.rtlabel != aw2->v.rtlabel); 1670 default: 1671 addlog("invalid address type: %d\n", aw1->type); 1672 return (1); 1673 } 1674 } 1675 1676 /* This algorithm computes 'a + b - c' in ones-complement using a trick to 1677 * emulate at most one ones-complement subtraction. This thereby limits net 1678 * carries/borrows to at most one, eliminating a reduction step and saving one 1679 * each of +, >>, & and ~. 1680 * 1681 * def. x mod y = x - (x//y)*y for integer x,y 1682 * def. sum = x mod 2^16 1683 * def. accumulator = (x >> 16) mod 2^16 1684 * 1685 * The trick works as follows: subtracting exactly one u_int16_t from the 1686 * u_int32_t x incurs at most one underflow, wrapping its upper 16-bits, the 1687 * accumulator, to 2^16 - 1. Adding this to the 16-bit sum preserves the 1688 * ones-complement borrow: 1689 * 1690 * (sum + accumulator) mod 2^16 1691 * = { assume underflow: accumulator := 2^16 - 1 } 1692 * (sum + 2^16 - 1) mod 2^16 1693 * = { mod } 1694 * (sum - 1) mod 2^16 1695 * 1696 * Although this breaks for sum = 0, giving 0xffff, which is ones-complement's 1697 * other zero, not -1, that cannot occur: the 16-bit sum cannot be underflown 1698 * to zero as that requires subtraction of at least 2^16, which exceeds a 1699 * single u_int16_t's range. 1700 * 1701 * We use the following theorem to derive the implementation: 1702 * 1703 * th. (x + (y mod z)) mod z = (x + y) mod z (0) 1704 * proof. 1705 * (x + (y mod z)) mod z 1706 * = { def mod } 1707 * (x + y - (y//z)*z) mod z 1708 * = { (a + b*c) mod c = a mod c } 1709 * (x + y) mod z [end of proof] 1710 * 1711 * ... and thereby obtain: 1712 * 1713 * (sum + accumulator) mod 2^16 1714 * = { def. accumulator, def. sum } 1715 * (x mod 2^16 + (x >> 16) mod 2^16) mod 2^16 1716 * = { (0), twice } 1717 * (x + (x >> 16)) mod 2^16 1718 * = { x mod 2^n = x & (2^n - 1) } 1719 * (x + (x >> 16)) & 0xffff 1720 * 1721 * Note: this serves also as a reduction step for at most one add (as the 1722 * trailing mod 2^16 prevents further reductions by destroying carries). 1723 */ 1724 static __inline void 1725 pf_cksum_fixup(u_int16_t *cksum, u_int16_t was, u_int16_t now, 1726 u_int8_t proto) 1727 { 1728 u_int32_t x; 1729 const int udp = proto == IPPROTO_UDP; 1730 1731 x = *cksum + was - now; 1732 x = (x + (x >> 16)) & 0xffff; 1733 1734 /* optimise: eliminate a branch when not udp */ 1735 if (udp && *cksum == 0x0000) 1736 return; 1737 if (udp && x == 0x0000) 1738 x = 0xffff; 1739 1740 *cksum = (u_int16_t)(x); 1741 } 1742 1743 /* pre: coverage(cksum) is superset of coverage(covered_cksum) */ 1744 static __inline void 1745 pf_cksum_uncover(u_int16_t *cksum, u_int16_t covered_cksum, u_int8_t proto) 1746 { 1747 pf_cksum_fixup(cksum, ~covered_cksum, 0x0, proto); 1748 } 1749 1750 /* pre: disjoint(coverage(cksum), coverage(uncovered_cksum)) */ 1751 static __inline void 1752 pf_cksum_cover(u_int16_t *cksum, u_int16_t uncovered_cksum, u_int8_t proto) 1753 { 1754 pf_cksum_fixup(cksum, 0x0, ~uncovered_cksum, proto); 1755 } 1756 1757 /* pre: *a is 16-bit aligned within its packet 1758 * 1759 * This algorithm emulates 16-bit ones-complement sums on a twos-complement 1760 * machine by conserving ones-complement's otherwise discarded carries in the 1761 * upper bits of x. These accumulated carries when added to the lower 16-bits 1762 * over at least zero 'reduction' steps then complete the ones-complement sum. 1763 * 1764 * def. sum = x mod 2^16 1765 * def. accumulator = (x >> 16) 1766 * 1767 * At most two reduction steps 1768 * 1769 * x := sum + accumulator 1770 * = { def sum, def accumulator } 1771 * x := x mod 2^16 + (x >> 16) 1772 * = { x mod 2^n = x & (2^n - 1) } 1773 * x := (x & 0xffff) + (x >> 16) 1774 * 1775 * are necessary to incorporate the accumulated carries (at most one per add) 1776 * i.e. to reduce x < 2^16 from at most 16 carries in the upper 16 bits. 1777 * 1778 * The function is also invariant over the endian of the host. Why? 1779 * 1780 * Define the unary transpose operator ~ on a bitstring in python slice 1781 * notation as lambda m: m[P:] + m[:P] , for some constant pivot P. 1782 * 1783 * th. ~ distributes over ones-complement addition, denoted by +_1, i.e. 1784 * 1785 * ~m +_1 ~n = ~(m +_1 n) (for all bitstrings m,n of equal length) 1786 * 1787 * proof. Regard the bitstrings in m +_1 n as split at P, forming at most two 1788 * 'half-adds'. Under ones-complement addition, each half-add carries to the 1789 * other, so the sum of each half-add is unaffected by their relative 1790 * order. Therefore: 1791 * 1792 * ~m +_1 ~n 1793 * = { half-adds invariant under transposition } 1794 * ~s 1795 * = { substitute } 1796 * ~(m +_1 n) [end of proof] 1797 * 1798 * th. Summing two in-memory ones-complement 16-bit variables m,n on a machine 1799 * with the converse endian does not alter the result. 1800 * 1801 * proof. 1802 * { converse machine endian: load/store transposes, P := 8 } 1803 * ~(~m +_1 ~n) 1804 * = { ~ over +_1 } 1805 * ~~m +_1 ~~n 1806 * = { ~ is an involution } 1807 * m +_1 n [end of proof] 1808 * 1809 */ 1810 #define NEG(x) ((u_int16_t)~(x)) 1811 void 1812 pf_cksum_fixup_a(u_int16_t *cksum, const struct pf_addr *a, 1813 const struct pf_addr *an, sa_family_t af, u_int8_t proto) 1814 { 1815 u_int32_t x; 1816 const u_int16_t *n = an->addr16; 1817 const u_int16_t *o = a->addr16; 1818 const int udp = proto == IPPROTO_UDP; 1819 1820 switch (af) { 1821 case AF_INET: 1822 x = *cksum + o[0] + NEG(n[0]) + o[1] + NEG(n[1]); 1823 break; 1824 #ifdef INET6 1825 case AF_INET6: 1826 x = *cksum + o[0] + NEG(n[0]) + o[1] + NEG(n[1]) +\ 1827 o[2] + NEG(n[2]) + o[3] + NEG(n[3]) +\ 1828 o[4] + NEG(n[4]) + o[5] + NEG(n[5]) +\ 1829 o[6] + NEG(n[6]) + o[7] + NEG(n[7]); 1830 break; 1831 #endif /* INET6 */ 1832 default: 1833 unhandled_af(af); 1834 } 1835 1836 x = (x & 0xffff) + (x >> 16); 1837 x = (x & 0xffff) + (x >> 16); 1838 1839 /* optimise: eliminate a branch when not udp */ 1840 if (udp && *cksum == 0x0000) 1841 return; 1842 if (udp && x == 0x0000) 1843 x = 0xffff; 1844 1845 *cksum = (u_int16_t)(x); 1846 } 1847 1848 int 1849 pf_patch_8(struct pf_pdesc *pd, u_int8_t *f, u_int8_t v, bool hi) 1850 { 1851 int rewrite = 0; 1852 1853 if (*f != v) { 1854 u_int16_t old = htons(hi ? (*f << 8) : *f); 1855 u_int16_t new = htons(hi ? ( v << 8) : v); 1856 1857 pf_cksum_fixup(pd->pcksum, old, new, pd->proto); 1858 *f = v; 1859 rewrite = 1; 1860 } 1861 1862 return (rewrite); 1863 } 1864 1865 /* pre: *f is 16-bit aligned within its packet */ 1866 int 1867 pf_patch_16(struct pf_pdesc *pd, u_int16_t *f, u_int16_t v) 1868 { 1869 int rewrite = 0; 1870 1871 if (*f != v) { 1872 pf_cksum_fixup(pd->pcksum, *f, v, pd->proto); 1873 *f = v; 1874 rewrite = 1; 1875 } 1876 1877 return (rewrite); 1878 } 1879 1880 int 1881 pf_patch_16_unaligned(struct pf_pdesc *pd, void *f, u_int16_t v, bool hi) 1882 { 1883 int rewrite = 0; 1884 u_int8_t *fb = (u_int8_t*)f; 1885 u_int8_t *vb = (u_int8_t*)&v; 1886 1887 if (hi && ALIGNED_POINTER(f, u_int16_t)) { 1888 return (pf_patch_16(pd, f, v)); /* optimise */ 1889 } 1890 1891 rewrite += pf_patch_8(pd, fb++, *vb++, hi); 1892 rewrite += pf_patch_8(pd, fb++, *vb++,!hi); 1893 1894 return (rewrite); 1895 } 1896 1897 /* pre: *f is 16-bit aligned within its packet */ 1898 /* pre: pd->proto != IPPROTO_UDP */ 1899 int 1900 pf_patch_32(struct pf_pdesc *pd, u_int32_t *f, u_int32_t v) 1901 { 1902 int rewrite = 0; 1903 u_int16_t *pc = pd->pcksum; 1904 u_int8_t proto = pd->proto; 1905 1906 /* optimise: inline udp fixup code is unused; let compiler scrub it */ 1907 if (proto == IPPROTO_UDP) 1908 panic("pf_patch_32: udp"); 1909 1910 /* optimise: skip *f != v guard; true for all use-cases */ 1911 pf_cksum_fixup(pc, *f / (1 << 16), v / (1 << 16), proto); 1912 pf_cksum_fixup(pc, *f % (1 << 16), v % (1 << 16), proto); 1913 1914 *f = v; 1915 rewrite = 1; 1916 1917 return (rewrite); 1918 } 1919 1920 int 1921 pf_patch_32_unaligned(struct pf_pdesc *pd, void *f, u_int32_t v, bool hi) 1922 { 1923 int rewrite = 0; 1924 u_int8_t *fb = (u_int8_t*)f; 1925 u_int8_t *vb = (u_int8_t*)&v; 1926 1927 if (hi && ALIGNED_POINTER(f, u_int32_t)) { 1928 return (pf_patch_32(pd, f, v)); /* optimise */ 1929 } 1930 1931 rewrite += pf_patch_8(pd, fb++, *vb++, hi); 1932 rewrite += pf_patch_8(pd, fb++, *vb++,!hi); 1933 rewrite += pf_patch_8(pd, fb++, *vb++, hi); 1934 rewrite += pf_patch_8(pd, fb++, *vb++,!hi); 1935 1936 return (rewrite); 1937 } 1938 1939 int 1940 pf_icmp_mapping(struct pf_pdesc *pd, u_int8_t type, int *icmp_dir, 1941 u_int16_t *virtual_id, u_int16_t *virtual_type) 1942 { 1943 /* 1944 * ICMP types marked with PF_OUT are typically responses to 1945 * PF_IN, and will match states in the opposite direction. 1946 * PF_IN ICMP types need to match a state with that type. 1947 */ 1948 *icmp_dir = PF_OUT; 1949 1950 /* Queries (and responses) */ 1951 switch (pd->af) { 1952 case AF_INET: 1953 switch (type) { 1954 case ICMP_ECHO: 1955 *icmp_dir = PF_IN; 1956 /* FALLTHROUGH */ 1957 case ICMP_ECHOREPLY: 1958 *virtual_type = ICMP_ECHO; 1959 *virtual_id = pd->hdr.icmp.icmp_id; 1960 break; 1961 1962 case ICMP_TSTAMP: 1963 *icmp_dir = PF_IN; 1964 /* FALLTHROUGH */ 1965 case ICMP_TSTAMPREPLY: 1966 *virtual_type = ICMP_TSTAMP; 1967 *virtual_id = pd->hdr.icmp.icmp_id; 1968 break; 1969 1970 case ICMP_IREQ: 1971 *icmp_dir = PF_IN; 1972 /* FALLTHROUGH */ 1973 case ICMP_IREQREPLY: 1974 *virtual_type = ICMP_IREQ; 1975 *virtual_id = pd->hdr.icmp.icmp_id; 1976 break; 1977 1978 case ICMP_MASKREQ: 1979 *icmp_dir = PF_IN; 1980 /* FALLTHROUGH */ 1981 case ICMP_MASKREPLY: 1982 *virtual_type = ICMP_MASKREQ; 1983 *virtual_id = pd->hdr.icmp.icmp_id; 1984 break; 1985 1986 case ICMP_IPV6_WHEREAREYOU: 1987 *icmp_dir = PF_IN; 1988 /* FALLTHROUGH */ 1989 case ICMP_IPV6_IAMHERE: 1990 *virtual_type = ICMP_IPV6_WHEREAREYOU; 1991 *virtual_id = 0; /* Nothing sane to match on! */ 1992 break; 1993 1994 case ICMP_MOBILE_REGREQUEST: 1995 *icmp_dir = PF_IN; 1996 /* FALLTHROUGH */ 1997 case ICMP_MOBILE_REGREPLY: 1998 *virtual_type = ICMP_MOBILE_REGREQUEST; 1999 *virtual_id = 0; /* Nothing sane to match on! */ 2000 break; 2001 2002 case ICMP_ROUTERSOLICIT: 2003 *icmp_dir = PF_IN; 2004 /* FALLTHROUGH */ 2005 case ICMP_ROUTERADVERT: 2006 *virtual_type = ICMP_ROUTERSOLICIT; 2007 *virtual_id = 0; /* Nothing sane to match on! */ 2008 break; 2009 2010 /* These ICMP types map to other connections */ 2011 case ICMP_UNREACH: 2012 case ICMP_SOURCEQUENCH: 2013 case ICMP_REDIRECT: 2014 case ICMP_TIMXCEED: 2015 case ICMP_PARAMPROB: 2016 /* These will not be used, but set them anyway */ 2017 *icmp_dir = PF_IN; 2018 *virtual_type = htons(type); 2019 *virtual_id = 0; 2020 return (1); /* These types match to another state */ 2021 2022 /* 2023 * All remaining ICMP types get their own states, 2024 * and will only match in one direction. 2025 */ 2026 default: 2027 *icmp_dir = PF_IN; 2028 *virtual_type = type; 2029 *virtual_id = 0; 2030 break; 2031 } 2032 break; 2033 #ifdef INET6 2034 case AF_INET6: 2035 switch (type) { 2036 case ICMP6_ECHO_REQUEST: 2037 *icmp_dir = PF_IN; 2038 /* FALLTHROUGH */ 2039 case ICMP6_ECHO_REPLY: 2040 *virtual_type = ICMP6_ECHO_REQUEST; 2041 *virtual_id = pd->hdr.icmp6.icmp6_id; 2042 break; 2043 2044 case MLD_LISTENER_QUERY: 2045 *icmp_dir = PF_IN; 2046 /* FALLTHROUGH */ 2047 case MLD_LISTENER_REPORT: { 2048 struct mld_hdr *mld = &pd->hdr.mld; 2049 u_int32_t h; 2050 2051 *virtual_type = MLD_LISTENER_QUERY; 2052 /* generate fake id for these messages */ 2053 h = mld->mld_addr.s6_addr32[0] ^ 2054 mld->mld_addr.s6_addr32[1] ^ 2055 mld->mld_addr.s6_addr32[2] ^ 2056 mld->mld_addr.s6_addr32[3]; 2057 *virtual_id = (h >> 16) ^ (h & 0xffff); 2058 break; 2059 } 2060 2061 /* 2062 * ICMP6_FQDN and ICMP6_NI query/reply are the same type as 2063 * ICMP6_WRU 2064 */ 2065 case ICMP6_WRUREQUEST: 2066 *icmp_dir = PF_IN; 2067 /* FALLTHROUGH */ 2068 case ICMP6_WRUREPLY: 2069 *virtual_type = ICMP6_WRUREQUEST; 2070 *virtual_id = 0; /* Nothing sane to match on! */ 2071 break; 2072 2073 case MLD_MTRACE: 2074 *icmp_dir = PF_IN; 2075 /* FALLTHROUGH */ 2076 case MLD_MTRACE_RESP: 2077 *virtual_type = MLD_MTRACE; 2078 *virtual_id = 0; /* Nothing sane to match on! */ 2079 break; 2080 2081 case ND_NEIGHBOR_SOLICIT: 2082 *icmp_dir = PF_IN; 2083 /* FALLTHROUGH */ 2084 case ND_NEIGHBOR_ADVERT: { 2085 struct nd_neighbor_solicit *nd = &pd->hdr.nd_ns; 2086 u_int32_t h; 2087 2088 *virtual_type = ND_NEIGHBOR_SOLICIT; 2089 /* generate fake id for these messages */ 2090 h = nd->nd_ns_target.s6_addr32[0] ^ 2091 nd->nd_ns_target.s6_addr32[1] ^ 2092 nd->nd_ns_target.s6_addr32[2] ^ 2093 nd->nd_ns_target.s6_addr32[3]; 2094 *virtual_id = (h >> 16) ^ (h & 0xffff); 2095 break; 2096 } 2097 2098 /* 2099 * These ICMP types map to other connections. 2100 * ND_REDIRECT can't be in this list because the triggering 2101 * packet header is optional. 2102 */ 2103 case ICMP6_DST_UNREACH: 2104 case ICMP6_PACKET_TOO_BIG: 2105 case ICMP6_TIME_EXCEEDED: 2106 case ICMP6_PARAM_PROB: 2107 /* These will not be used, but set them anyway */ 2108 *icmp_dir = PF_IN; 2109 *virtual_type = htons(type); 2110 *virtual_id = 0; 2111 return (1); /* These types match to another state */ 2112 /* 2113 * All remaining ICMP6 types get their own states, 2114 * and will only match in one direction. 2115 */ 2116 default: 2117 *icmp_dir = PF_IN; 2118 *virtual_type = type; 2119 *virtual_id = 0; 2120 break; 2121 } 2122 break; 2123 #endif /* INET6 */ 2124 } 2125 *virtual_type = htons(*virtual_type); 2126 return (0); /* These types match to their own state */ 2127 } 2128 2129 void 2130 pf_translate_icmp(struct pf_pdesc *pd, struct pf_addr *qa, u_int16_t *qp, 2131 struct pf_addr *oa, struct pf_addr *na, u_int16_t np) 2132 { 2133 /* note: doesn't trouble to fixup quoted checksums, if any */ 2134 2135 /* change quoted protocol port */ 2136 if (qp != NULL) 2137 pf_patch_16(pd, qp, np); 2138 2139 /* change quoted ip address */ 2140 pf_cksum_fixup_a(pd->pcksum, qa, na, pd->af, pd->proto); 2141 PF_ACPY(qa, na, pd->af); 2142 2143 /* change network-header's ip address */ 2144 if (oa) 2145 pf_translate_a(pd, oa, na); 2146 } 2147 2148 /* pre: *a is 16-bit aligned within its packet */ 2149 /* *a is a network header src/dst address */ 2150 int 2151 pf_translate_a(struct pf_pdesc *pd, struct pf_addr *a, struct pf_addr *an) 2152 { 2153 int rewrite = 0; 2154 2155 /* warning: !PF_ANEQ != PF_AEQ */ 2156 if (!PF_ANEQ(a, an, pd->af)) 2157 return (0); 2158 2159 /* fixup transport pseudo-header, if any */ 2160 switch (pd->proto) { 2161 case IPPROTO_TCP: /* FALLTHROUGH */ 2162 case IPPROTO_UDP: /* FALLTHROUGH */ 2163 case IPPROTO_ICMPV6: 2164 pf_cksum_fixup_a(pd->pcksum, a, an, pd->af, pd->proto); 2165 break; 2166 default: 2167 break; /* assume no pseudo-header */ 2168 } 2169 2170 PF_ACPY(a, an, pd->af); 2171 rewrite = 1; 2172 2173 return (rewrite); 2174 } 2175 2176 #if INET6 2177 /* pf_translate_af() may change pd->m, adjust local copies after calling */ 2178 int 2179 pf_translate_af(struct pf_pdesc *pd) 2180 { 2181 static const struct pf_addr zero; 2182 struct ip *ip4; 2183 struct ip6_hdr *ip6; 2184 int copyback = 0; 2185 u_int hlen, ohlen, dlen; 2186 u_int16_t *pc; 2187 u_int8_t af_proto, naf_proto; 2188 2189 hlen = (pd->naf == AF_INET) ? sizeof(*ip4) : sizeof(*ip6); 2190 ohlen = pd->off; 2191 dlen = pd->tot_len - pd->off; 2192 pc = pd->pcksum; 2193 2194 af_proto = naf_proto = pd->proto; 2195 if (naf_proto == IPPROTO_ICMP) 2196 af_proto = IPPROTO_ICMPV6; 2197 if (naf_proto == IPPROTO_ICMPV6) 2198 af_proto = IPPROTO_ICMP; 2199 2200 /* uncover stale pseudo-header */ 2201 switch (af_proto) { 2202 case IPPROTO_ICMPV6: 2203 /* optimise: unchanged for TCP/UDP */ 2204 pf_cksum_fixup(pc, htons(af_proto), 0x0, af_proto); 2205 pf_cksum_fixup(pc, htons(dlen), 0x0, af_proto); 2206 /* FALLTHROUGH */ 2207 case IPPROTO_UDP: /* FALLTHROUGH */ 2208 case IPPROTO_TCP: 2209 pf_cksum_fixup_a(pc, pd->src, &zero, pd->af, af_proto); 2210 pf_cksum_fixup_a(pc, pd->dst, &zero, pd->af, af_proto); 2211 copyback = 1; 2212 break; 2213 default: 2214 break; /* assume no pseudo-header */ 2215 } 2216 2217 /* replace the network header */ 2218 m_adj(pd->m, pd->off); 2219 pd->src = NULL; 2220 pd->dst = NULL; 2221 2222 if ((M_PREPEND(pd->m, hlen, M_DONTWAIT)) == NULL) { 2223 pd->m = NULL; 2224 return (-1); 2225 } 2226 2227 pd->off = hlen; 2228 pd->tot_len += hlen - ohlen; 2229 2230 switch (pd->naf) { 2231 case AF_INET: 2232 ip4 = mtod(pd->m, struct ip *); 2233 bzero(ip4, hlen); 2234 ip4->ip_v = IPVERSION; 2235 ip4->ip_hl = hlen >> 2; 2236 ip4->ip_tos = pd->tos; 2237 ip4->ip_len = htons(hlen + dlen); 2238 ip4->ip_id = htons(ip_randomid()); 2239 ip4->ip_off = htons(IP_DF); 2240 ip4->ip_ttl = pd->ttl; 2241 ip4->ip_p = pd->proto; 2242 ip4->ip_src = pd->nsaddr.v4; 2243 ip4->ip_dst = pd->ndaddr.v4; 2244 break; 2245 case AF_INET6: 2246 ip6 = mtod(pd->m, struct ip6_hdr *); 2247 bzero(ip6, hlen); 2248 ip6->ip6_vfc = IPV6_VERSION; 2249 ip6->ip6_flow |= htonl((u_int32_t)pd->tos << 20); 2250 ip6->ip6_plen = htons(dlen); 2251 ip6->ip6_nxt = pd->proto; 2252 if (!pd->ttl || pd->ttl > IPV6_DEFHLIM) 2253 ip6->ip6_hlim = IPV6_DEFHLIM; 2254 else 2255 ip6->ip6_hlim = pd->ttl; 2256 ip6->ip6_src = pd->nsaddr.v6; 2257 ip6->ip6_dst = pd->ndaddr.v6; 2258 break; 2259 default: 2260 unhandled_af(pd->naf); 2261 } 2262 2263 /* UDP over IPv6 must be checksummed per rfc2460 p27 */ 2264 if (naf_proto == IPPROTO_UDP && *pc == 0x0000 && 2265 pd->naf == AF_INET6) { 2266 pd->m->m_pkthdr.csum_flags |= M_UDP_CSUM_OUT; 2267 } 2268 2269 /* cover fresh pseudo-header */ 2270 switch (naf_proto) { 2271 case IPPROTO_ICMPV6: 2272 /* optimise: unchanged for TCP/UDP */ 2273 pf_cksum_fixup(pc, 0x0, htons(naf_proto), naf_proto); 2274 pf_cksum_fixup(pc, 0x0, htons(dlen), naf_proto); 2275 /* FALLTHROUGH */ 2276 case IPPROTO_UDP: /* FALLTHROUGH */ 2277 case IPPROTO_TCP: 2278 pf_cksum_fixup_a(pc, &zero, &pd->nsaddr, pd->naf, naf_proto); 2279 pf_cksum_fixup_a(pc, &zero, &pd->ndaddr, pd->naf, naf_proto); 2280 copyback = 1; 2281 break; 2282 default: 2283 break; /* assume no pseudo-header */ 2284 } 2285 2286 /* flush pd->pcksum */ 2287 if (copyback) 2288 m_copyback(pd->m, pd->off, pd->hdrlen, &pd->hdr, M_NOWAIT); 2289 2290 return (0); 2291 } 2292 2293 int 2294 pf_change_icmp_af(struct mbuf *m, int ipoff2, struct pf_pdesc *pd, 2295 struct pf_pdesc *pd2, struct pf_addr *src, struct pf_addr *dst, 2296 sa_family_t af, sa_family_t naf) 2297 { 2298 struct mbuf *n = NULL; 2299 struct ip *ip4; 2300 struct ip6_hdr *ip6; 2301 u_int hlen, ohlen, dlen; 2302 int d; 2303 2304 if (af == naf || (af != AF_INET && af != AF_INET6) || 2305 (naf != AF_INET && naf != AF_INET6)) 2306 return (-1); 2307 2308 /* split the mbuf chain on the quoted ip/ip6 header boundary */ 2309 if ((n = m_split(m, ipoff2, M_DONTWAIT)) == NULL) 2310 return (-1); 2311 2312 /* new quoted header */ 2313 hlen = naf == AF_INET ? sizeof(*ip4) : sizeof(*ip6); 2314 /* old quoted header */ 2315 ohlen = pd2->off - ipoff2; 2316 2317 /* trim old quoted header */ 2318 pf_cksum_uncover(pd->pcksum, in_cksum(n, ohlen), pd->proto); 2319 m_adj(n, ohlen); 2320 2321 /* prepend a new, translated, quoted header */ 2322 if ((M_PREPEND(n, hlen, M_DONTWAIT)) == NULL) 2323 return (-1); 2324 2325 switch (naf) { 2326 case AF_INET: 2327 ip4 = mtod(n, struct ip *); 2328 bzero(ip4, sizeof(*ip4)); 2329 ip4->ip_v = IPVERSION; 2330 ip4->ip_hl = sizeof(*ip4) >> 2; 2331 ip4->ip_len = htons(sizeof(*ip4) + pd2->tot_len - ohlen); 2332 ip4->ip_id = htons(ip_randomid()); 2333 ip4->ip_off = htons(IP_DF); 2334 ip4->ip_ttl = pd2->ttl; 2335 if (pd2->proto == IPPROTO_ICMPV6) 2336 ip4->ip_p = IPPROTO_ICMP; 2337 else 2338 ip4->ip_p = pd2->proto; 2339 ip4->ip_src = src->v4; 2340 ip4->ip_dst = dst->v4; 2341 ip4->ip_sum = in_cksum(n, ip4->ip_hl << 2); 2342 break; 2343 case AF_INET6: 2344 ip6 = mtod(n, struct ip6_hdr *); 2345 bzero(ip6, sizeof(*ip6)); 2346 ip6->ip6_vfc = IPV6_VERSION; 2347 ip6->ip6_plen = htons(pd2->tot_len - ohlen); 2348 if (pd2->proto == IPPROTO_ICMP) 2349 ip6->ip6_nxt = IPPROTO_ICMPV6; 2350 else 2351 ip6->ip6_nxt = pd2->proto; 2352 if (!pd2->ttl || pd2->ttl > IPV6_DEFHLIM) 2353 ip6->ip6_hlim = IPV6_DEFHLIM; 2354 else 2355 ip6->ip6_hlim = pd2->ttl; 2356 ip6->ip6_src = src->v6; 2357 ip6->ip6_dst = dst->v6; 2358 break; 2359 } 2360 2361 /* cover new quoted header */ 2362 /* optimise: any new AF_INET header of ours sums to zero */ 2363 if (naf != AF_INET) { 2364 pf_cksum_cover(pd->pcksum, in_cksum(n, hlen), pd->proto); 2365 } 2366 2367 /* reattach modified quoted packet to outer header */ 2368 { 2369 int nlen = n->m_pkthdr.len; 2370 m_cat(m, n); 2371 m->m_pkthdr.len += nlen; 2372 } 2373 2374 /* account for altered length */ 2375 d = hlen - ohlen; 2376 2377 if (pd->proto == IPPROTO_ICMPV6) { 2378 /* fixup pseudo-header */ 2379 dlen = pd->tot_len - pd->off; 2380 pf_cksum_fixup(pd->pcksum, 2381 htons(dlen), htons(dlen + d), pd->proto); 2382 } 2383 2384 pd->tot_len += d; 2385 pd2->tot_len += d; 2386 pd2->off += d; 2387 2388 /* note: not bothering to update network headers as 2389 these due for rewrite by pf_translate_af() */ 2390 2391 return (0); 2392 } 2393 2394 2395 #define PTR_IP(field) (offsetof(struct ip, field)) 2396 #define PTR_IP6(field) (offsetof(struct ip6_hdr, field)) 2397 2398 int 2399 pf_translate_icmp_af(struct pf_pdesc *pd, int af, void *arg) 2400 { 2401 struct icmp *icmp4; 2402 struct icmp6_hdr *icmp6; 2403 u_int32_t mtu; 2404 int32_t ptr = -1; 2405 u_int8_t type; 2406 u_int8_t code; 2407 2408 switch (af) { 2409 case AF_INET: 2410 icmp6 = arg; 2411 type = icmp6->icmp6_type; 2412 code = icmp6->icmp6_code; 2413 mtu = ntohl(icmp6->icmp6_mtu); 2414 2415 switch (type) { 2416 case ICMP6_ECHO_REQUEST: 2417 type = ICMP_ECHO; 2418 break; 2419 case ICMP6_ECHO_REPLY: 2420 type = ICMP_ECHOREPLY; 2421 break; 2422 case ICMP6_DST_UNREACH: 2423 type = ICMP_UNREACH; 2424 switch (code) { 2425 case ICMP6_DST_UNREACH_NOROUTE: 2426 case ICMP6_DST_UNREACH_BEYONDSCOPE: 2427 case ICMP6_DST_UNREACH_ADDR: 2428 code = ICMP_UNREACH_HOST; 2429 break; 2430 case ICMP6_DST_UNREACH_ADMIN: 2431 code = ICMP_UNREACH_HOST_PROHIB; 2432 break; 2433 case ICMP6_DST_UNREACH_NOPORT: 2434 code = ICMP_UNREACH_PORT; 2435 break; 2436 default: 2437 return (-1); 2438 } 2439 break; 2440 case ICMP6_PACKET_TOO_BIG: 2441 type = ICMP_UNREACH; 2442 code = ICMP_UNREACH_NEEDFRAG; 2443 mtu -= 20; 2444 break; 2445 case ICMP6_TIME_EXCEEDED: 2446 type = ICMP_TIMXCEED; 2447 break; 2448 case ICMP6_PARAM_PROB: 2449 switch (code) { 2450 case ICMP6_PARAMPROB_HEADER: 2451 type = ICMP_PARAMPROB; 2452 code = ICMP_PARAMPROB_ERRATPTR; 2453 ptr = ntohl(icmp6->icmp6_pptr); 2454 2455 if (ptr == PTR_IP6(ip6_vfc)) 2456 ; /* preserve */ 2457 else if (ptr == PTR_IP6(ip6_vfc) + 1) 2458 ptr = PTR_IP(ip_tos); 2459 else if (ptr == PTR_IP6(ip6_plen) || 2460 ptr == PTR_IP6(ip6_plen) + 1) 2461 ptr = PTR_IP(ip_len); 2462 else if (ptr == PTR_IP6(ip6_nxt)) 2463 ptr = PTR_IP(ip_p); 2464 else if (ptr == PTR_IP6(ip6_hlim)) 2465 ptr = PTR_IP(ip_ttl); 2466 else if (ptr >= PTR_IP6(ip6_src) && 2467 ptr < PTR_IP6(ip6_dst)) 2468 ptr = PTR_IP(ip_src); 2469 else if (ptr >= PTR_IP6(ip6_dst) && 2470 ptr < sizeof(struct ip6_hdr)) 2471 ptr = PTR_IP(ip_dst); 2472 else { 2473 return (-1); 2474 } 2475 break; 2476 case ICMP6_PARAMPROB_NEXTHEADER: 2477 type = ICMP_UNREACH; 2478 code = ICMP_UNREACH_PROTOCOL; 2479 break; 2480 default: 2481 return (-1); 2482 } 2483 break; 2484 default: 2485 return (-1); 2486 } 2487 2488 pf_patch_8(pd, &icmp6->icmp6_type, type, PF_HI); 2489 pf_patch_8(pd, &icmp6->icmp6_code, code, PF_LO); 2490 2491 /* aligns well with a icmpv4 nextmtu */ 2492 pf_patch_32(pd, &icmp6->icmp6_mtu, htonl(mtu)); 2493 2494 /* icmpv4 pptr is a one most significant byte */ 2495 if (ptr >= 0) 2496 pf_patch_32(pd, &icmp6->icmp6_pptr, htonl(ptr << 24)); 2497 break; 2498 case AF_INET6: 2499 icmp4 = arg; 2500 type = icmp4->icmp_type; 2501 code = icmp4->icmp_code; 2502 mtu = ntohs(icmp4->icmp_nextmtu); 2503 2504 switch (type) { 2505 case ICMP_ECHO: 2506 type = ICMP6_ECHO_REQUEST; 2507 break; 2508 case ICMP_ECHOREPLY: 2509 type = ICMP6_ECHO_REPLY; 2510 break; 2511 case ICMP_UNREACH: 2512 type = ICMP6_DST_UNREACH; 2513 switch (code) { 2514 case ICMP_UNREACH_NET: 2515 case ICMP_UNREACH_HOST: 2516 case ICMP_UNREACH_NET_UNKNOWN: 2517 case ICMP_UNREACH_HOST_UNKNOWN: 2518 case ICMP_UNREACH_ISOLATED: 2519 case ICMP_UNREACH_TOSNET: 2520 case ICMP_UNREACH_TOSHOST: 2521 code = ICMP6_DST_UNREACH_NOROUTE; 2522 break; 2523 case ICMP_UNREACH_PORT: 2524 code = ICMP6_DST_UNREACH_NOPORT; 2525 break; 2526 case ICMP_UNREACH_NET_PROHIB: 2527 case ICMP_UNREACH_HOST_PROHIB: 2528 case ICMP_UNREACH_FILTER_PROHIB: 2529 case ICMP_UNREACH_PRECEDENCE_CUTOFF: 2530 code = ICMP6_DST_UNREACH_ADMIN; 2531 break; 2532 case ICMP_UNREACH_PROTOCOL: 2533 type = ICMP6_PARAM_PROB; 2534 code = ICMP6_PARAMPROB_NEXTHEADER; 2535 ptr = offsetof(struct ip6_hdr, ip6_nxt); 2536 break; 2537 case ICMP_UNREACH_NEEDFRAG: 2538 type = ICMP6_PACKET_TOO_BIG; 2539 code = 0; 2540 mtu += 20; 2541 break; 2542 default: 2543 return (-1); 2544 } 2545 break; 2546 case ICMP_TIMXCEED: 2547 type = ICMP6_TIME_EXCEEDED; 2548 break; 2549 case ICMP_PARAMPROB: 2550 type = ICMP6_PARAM_PROB; 2551 switch (code) { 2552 case ICMP_PARAMPROB_ERRATPTR: 2553 code = ICMP6_PARAMPROB_HEADER; 2554 break; 2555 case ICMP_PARAMPROB_LENGTH: 2556 code = ICMP6_PARAMPROB_HEADER; 2557 break; 2558 default: 2559 return (-1); 2560 } 2561 2562 ptr = icmp4->icmp_pptr; 2563 if (ptr == 0 || ptr == PTR_IP(ip_tos)) 2564 ; /* preserve */ 2565 else if (ptr == PTR_IP(ip_len) || 2566 ptr == PTR_IP(ip_len) + 1) 2567 ptr = PTR_IP6(ip6_plen); 2568 else if (ptr == PTR_IP(ip_ttl)) 2569 ptr = PTR_IP6(ip6_hlim); 2570 else if (ptr == PTR_IP(ip_p)) 2571 ptr = PTR_IP6(ip6_nxt); 2572 else if (ptr >= PTR_IP(ip_src) && 2573 ptr < PTR_IP(ip_dst)) 2574 ptr = PTR_IP6(ip6_src); 2575 else if (ptr >= PTR_IP(ip_dst) && 2576 ptr < sizeof(struct ip)) 2577 ptr = PTR_IP6(ip6_dst); 2578 else { 2579 return (-1); 2580 } 2581 break; 2582 default: 2583 return (-1); 2584 } 2585 2586 pf_patch_8(pd, &icmp4->icmp_type, type, PF_HI); 2587 pf_patch_8(pd, &icmp4->icmp_code, code, PF_LO); 2588 pf_patch_16(pd, &icmp4->icmp_nextmtu, htons(mtu)); 2589 if (ptr >= 0) 2590 pf_patch_32(pd, &icmp4->icmp_void, htonl(ptr)); 2591 break; 2592 } 2593 2594 return (0); 2595 } 2596 #endif /* INET6 */ 2597 2598 /* 2599 * Need to modulate the sequence numbers in the TCP SACK option 2600 * (credits to Krzysztof Pfaff for report and patch) 2601 */ 2602 int 2603 pf_modulate_sack(struct pf_pdesc *pd, struct pf_state_peer *dst) 2604 { 2605 struct tcphdr *th = &pd->hdr.tcp; 2606 int hlen = (th->th_off << 2) - sizeof(*th); 2607 int thoptlen = hlen; 2608 u_int8_t opts[MAX_TCPOPTLEN], *opt = opts; 2609 int copyback = 0, i, olen; 2610 struct sackblk sack; 2611 2612 #define TCPOLEN_SACKLEN (TCPOLEN_SACK + 2) 2613 if (hlen < TCPOLEN_SACKLEN || hlen > MAX_TCPOPTLEN || !pf_pull_hdr( 2614 pd->m, pd->off + sizeof(*th), opts, hlen, NULL, NULL, pd->af)) 2615 return 0; 2616 2617 while (hlen >= TCPOLEN_SACKLEN) { 2618 olen = opt[1]; 2619 switch (*opt) { 2620 case TCPOPT_EOL: /* FALLTHROUGH */ 2621 case TCPOPT_NOP: 2622 opt++; 2623 hlen--; 2624 break; 2625 case TCPOPT_SACK: 2626 if (olen > hlen) 2627 olen = hlen; 2628 if (olen >= TCPOLEN_SACKLEN) { 2629 for (i = 2; i + TCPOLEN_SACK <= olen; 2630 i += TCPOLEN_SACK) { 2631 size_t startoff = (opt + i) - opts; 2632 memcpy(&sack, &opt[i], sizeof(sack)); 2633 pf_patch_32_unaligned(pd, &sack.start, 2634 htonl(ntohl(sack.start) - 2635 dst->seqdiff), 2636 PF_ALGNMNT(startoff)); 2637 pf_patch_32_unaligned(pd, &sack.end, 2638 htonl(ntohl(sack.end) - 2639 dst->seqdiff), 2640 PF_ALGNMNT(startoff + 2641 sizeof(sack.start))); 2642 memcpy(&opt[i], &sack, sizeof(sack)); 2643 } 2644 copyback = 1; 2645 } 2646 /* FALLTHROUGH */ 2647 default: 2648 if (olen < 2) 2649 olen = 2; 2650 hlen -= olen; 2651 opt += olen; 2652 } 2653 } 2654 2655 if (copyback) 2656 m_copyback(pd->m, pd->off + sizeof(*th), thoptlen, opts, 2657 M_NOWAIT); 2658 return (copyback); 2659 } 2660 2661 struct mbuf * 2662 pf_build_tcp(const struct pf_rule *r, sa_family_t af, 2663 const struct pf_addr *saddr, const struct pf_addr *daddr, 2664 u_int16_t sport, u_int16_t dport, u_int32_t seq, u_int32_t ack, 2665 u_int8_t flags, u_int16_t win, u_int16_t mss, u_int8_t ttl, int tag, 2666 u_int16_t rtag, u_int rdom) 2667 { 2668 struct mbuf *m; 2669 int len, tlen; 2670 struct ip *h; 2671 #ifdef INET6 2672 struct ip6_hdr *h6; 2673 #endif /* INET6 */ 2674 struct tcphdr *th; 2675 char *opt; 2676 2677 /* maximum segment size tcp option */ 2678 tlen = sizeof(struct tcphdr); 2679 if (mss) 2680 tlen += 4; 2681 2682 switch (af) { 2683 case AF_INET: 2684 len = sizeof(struct ip) + tlen; 2685 break; 2686 #ifdef INET6 2687 case AF_INET6: 2688 len = sizeof(struct ip6_hdr) + tlen; 2689 break; 2690 #endif /* INET6 */ 2691 default: 2692 unhandled_af(af); 2693 } 2694 2695 /* create outgoing mbuf */ 2696 m = m_gethdr(M_DONTWAIT, MT_HEADER); 2697 if (m == NULL) 2698 return (NULL); 2699 if (tag) 2700 m->m_pkthdr.pf.flags |= PF_TAG_GENERATED; 2701 m->m_pkthdr.pf.tag = rtag; 2702 m->m_pkthdr.ph_rtableid = rdom; 2703 if (r && (r->scrub_flags & PFSTATE_SETPRIO)) 2704 m->m_pkthdr.pf.prio = r->set_prio[0]; 2705 if (r && r->qid) 2706 m->m_pkthdr.pf.qid = r->qid; 2707 m->m_data += max_linkhdr; 2708 m->m_pkthdr.len = m->m_len = len; 2709 m->m_pkthdr.ph_ifidx = 0; 2710 m->m_pkthdr.csum_flags |= M_TCP_CSUM_OUT; 2711 bzero(m->m_data, len); 2712 switch (af) { 2713 case AF_INET: 2714 h = mtod(m, struct ip *); 2715 h->ip_p = IPPROTO_TCP; 2716 h->ip_len = htons(tlen); 2717 h->ip_v = 4; 2718 h->ip_hl = sizeof(*h) >> 2; 2719 h->ip_tos = IPTOS_LOWDELAY; 2720 h->ip_len = htons(len); 2721 h->ip_off = htons(ip_mtudisc ? IP_DF : 0); 2722 h->ip_ttl = ttl ? ttl : ip_defttl; 2723 h->ip_sum = 0; 2724 h->ip_src.s_addr = saddr->v4.s_addr; 2725 h->ip_dst.s_addr = daddr->v4.s_addr; 2726 2727 th = (struct tcphdr *)((caddr_t)h + sizeof(struct ip)); 2728 break; 2729 #ifdef INET6 2730 case AF_INET6: 2731 h6 = mtod(m, struct ip6_hdr *); 2732 h6->ip6_nxt = IPPROTO_TCP; 2733 h6->ip6_plen = htons(tlen); 2734 h6->ip6_vfc |= IPV6_VERSION; 2735 h6->ip6_hlim = IPV6_DEFHLIM; 2736 memcpy(&h6->ip6_src, &saddr->v6, sizeof(struct in6_addr)); 2737 memcpy(&h6->ip6_dst, &daddr->v6, sizeof(struct in6_addr)); 2738 2739 th = (struct tcphdr *)((caddr_t)h6 + sizeof(struct ip6_hdr)); 2740 break; 2741 #endif /* INET6 */ 2742 default: 2743 unhandled_af(af); 2744 } 2745 2746 /* TCP header */ 2747 th->th_sport = sport; 2748 th->th_dport = dport; 2749 th->th_seq = htonl(seq); 2750 th->th_ack = htonl(ack); 2751 th->th_off = tlen >> 2; 2752 th->th_flags = flags; 2753 th->th_win = htons(win); 2754 2755 if (mss) { 2756 opt = (char *)(th + 1); 2757 opt[0] = TCPOPT_MAXSEG; 2758 opt[1] = 4; 2759 mss = htons(mss); 2760 memcpy((opt + 2), &mss, 2); 2761 } 2762 2763 return (m); 2764 } 2765 2766 void 2767 pf_send_tcp(const struct pf_rule *r, sa_family_t af, 2768 const struct pf_addr *saddr, const struct pf_addr *daddr, 2769 u_int16_t sport, u_int16_t dport, u_int32_t seq, u_int32_t ack, 2770 u_int8_t flags, u_int16_t win, u_int16_t mss, u_int8_t ttl, int tag, 2771 u_int16_t rtag, u_int rdom) 2772 { 2773 struct mbuf *m; 2774 2775 if ((m = pf_build_tcp(r, af, saddr, daddr, sport, dport, seq, ack, 2776 flags, win, mss, ttl, tag, rtag, rdom)) == NULL) 2777 return; 2778 2779 switch (af) { 2780 case AF_INET: 2781 ip_send(m); 2782 break; 2783 #ifdef INET6 2784 case AF_INET6: 2785 ip6_send(m); 2786 break; 2787 #endif /* INET6 */ 2788 } 2789 } 2790 2791 static void 2792 pf_send_challenge_ack(struct pf_pdesc *pd, struct pf_state *s, 2793 struct pf_state_peer *src, struct pf_state_peer *dst) 2794 { 2795 /* 2796 * We are sending challenge ACK as a response to SYN packet, which 2797 * matches existing state (modulo TCP window check). Therefore packet 2798 * must be sent on behalf of destination. 2799 * 2800 * We expect sender to remain either silent, or send RST packet 2801 * so both, firewall and remote peer, can purge dead state from 2802 * memory. 2803 */ 2804 pf_send_tcp(s->rule.ptr, pd->af, pd->dst, pd->src, 2805 pd->hdr.tcp.th_dport, pd->hdr.tcp.th_sport, dst->seqlo, 2806 src->seqlo, TH_ACK, 0, 0, s->rule.ptr->return_ttl, 1, 0, 2807 pd->rdomain); 2808 } 2809 2810 void 2811 pf_send_icmp(struct mbuf *m, u_int8_t type, u_int8_t code, sa_family_t af, 2812 struct pf_rule *r, u_int rdomain) 2813 { 2814 struct mbuf *m0; 2815 2816 if ((m0 = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) 2817 return; 2818 2819 m0->m_pkthdr.pf.flags |= PF_TAG_GENERATED; 2820 m0->m_pkthdr.ph_rtableid = rdomain; 2821 if (r && (r->scrub_flags & PFSTATE_SETPRIO)) 2822 m0->m_pkthdr.pf.prio = r->set_prio[0]; 2823 if (r && r->qid) 2824 m0->m_pkthdr.pf.qid = r->qid; 2825 2826 switch (af) { 2827 case AF_INET: 2828 icmp_error(m0, type, code, 0, 0); 2829 break; 2830 #ifdef INET6 2831 case AF_INET6: 2832 icmp6_error(m0, type, code, 0); 2833 break; 2834 #endif /* INET6 */ 2835 } 2836 } 2837 2838 /* 2839 * Return ((n = 0) == (a = b [with mask m])) 2840 * Note: n != 0 => returns (a != b [with mask m]) 2841 */ 2842 int 2843 pf_match_addr(u_int8_t n, struct pf_addr *a, struct pf_addr *m, 2844 struct pf_addr *b, sa_family_t af) 2845 { 2846 switch (af) { 2847 case AF_INET: 2848 if ((a->addr32[0] & m->addr32[0]) == 2849 (b->addr32[0] & m->addr32[0])) 2850 return (n == 0); 2851 break; 2852 #ifdef INET6 2853 case AF_INET6: 2854 if (((a->addr32[0] & m->addr32[0]) == 2855 (b->addr32[0] & m->addr32[0])) && 2856 ((a->addr32[1] & m->addr32[1]) == 2857 (b->addr32[1] & m->addr32[1])) && 2858 ((a->addr32[2] & m->addr32[2]) == 2859 (b->addr32[2] & m->addr32[2])) && 2860 ((a->addr32[3] & m->addr32[3]) == 2861 (b->addr32[3] & m->addr32[3]))) 2862 return (n == 0); 2863 break; 2864 #endif /* INET6 */ 2865 } 2866 2867 return (n != 0); 2868 } 2869 2870 /* 2871 * Return 1 if b <= a <= e, otherwise return 0. 2872 */ 2873 int 2874 pf_match_addr_range(struct pf_addr *b, struct pf_addr *e, 2875 struct pf_addr *a, sa_family_t af) 2876 { 2877 switch (af) { 2878 case AF_INET: 2879 if ((ntohl(a->addr32[0]) < ntohl(b->addr32[0])) || 2880 (ntohl(a->addr32[0]) > ntohl(e->addr32[0]))) 2881 return (0); 2882 break; 2883 #ifdef INET6 2884 case AF_INET6: { 2885 int i; 2886 2887 /* check a >= b */ 2888 for (i = 0; i < 4; ++i) 2889 if (ntohl(a->addr32[i]) > ntohl(b->addr32[i])) 2890 break; 2891 else if (ntohl(a->addr32[i]) < ntohl(b->addr32[i])) 2892 return (0); 2893 /* check a <= e */ 2894 for (i = 0; i < 4; ++i) 2895 if (ntohl(a->addr32[i]) < ntohl(e->addr32[i])) 2896 break; 2897 else if (ntohl(a->addr32[i]) > ntohl(e->addr32[i])) 2898 return (0); 2899 break; 2900 } 2901 #endif /* INET6 */ 2902 } 2903 return (1); 2904 } 2905 2906 int 2907 pf_match(u_int8_t op, u_int32_t a1, u_int32_t a2, u_int32_t p) 2908 { 2909 switch (op) { 2910 case PF_OP_IRG: 2911 return ((p > a1) && (p < a2)); 2912 case PF_OP_XRG: 2913 return ((p < a1) || (p > a2)); 2914 case PF_OP_RRG: 2915 return ((p >= a1) && (p <= a2)); 2916 case PF_OP_EQ: 2917 return (p == a1); 2918 case PF_OP_NE: 2919 return (p != a1); 2920 case PF_OP_LT: 2921 return (p < a1); 2922 case PF_OP_LE: 2923 return (p <= a1); 2924 case PF_OP_GT: 2925 return (p > a1); 2926 case PF_OP_GE: 2927 return (p >= a1); 2928 } 2929 return (0); /* never reached */ 2930 } 2931 2932 int 2933 pf_match_port(u_int8_t op, u_int16_t a1, u_int16_t a2, u_int16_t p) 2934 { 2935 return (pf_match(op, ntohs(a1), ntohs(a2), ntohs(p))); 2936 } 2937 2938 int 2939 pf_match_uid(u_int8_t op, uid_t a1, uid_t a2, uid_t u) 2940 { 2941 if (u == UID_MAX && op != PF_OP_EQ && op != PF_OP_NE) 2942 return (0); 2943 return (pf_match(op, a1, a2, u)); 2944 } 2945 2946 int 2947 pf_match_gid(u_int8_t op, gid_t a1, gid_t a2, gid_t g) 2948 { 2949 if (g == GID_MAX && op != PF_OP_EQ && op != PF_OP_NE) 2950 return (0); 2951 return (pf_match(op, a1, a2, g)); 2952 } 2953 2954 int 2955 pf_match_tag(struct mbuf *m, struct pf_rule *r, int *tag) 2956 { 2957 if (*tag == -1) 2958 *tag = m->m_pkthdr.pf.tag; 2959 2960 return ((!r->match_tag_not && r->match_tag == *tag) || 2961 (r->match_tag_not && r->match_tag != *tag)); 2962 } 2963 2964 int 2965 pf_match_rcvif(struct mbuf *m, struct pf_rule *r) 2966 { 2967 struct ifnet *ifp; 2968 struct pfi_kif *kif; 2969 2970 ifp = if_get(m->m_pkthdr.ph_ifidx); 2971 if (ifp == NULL) 2972 return (0); 2973 2974 #if NCARP > 0 2975 if (ifp->if_type == IFT_CARP && ifp->if_carpdev) 2976 kif = (struct pfi_kif *)ifp->if_carpdev->if_pf_kif; 2977 else 2978 #endif /* NCARP */ 2979 kif = (struct pfi_kif *)ifp->if_pf_kif; 2980 2981 if_put(ifp); 2982 2983 if (kif == NULL) { 2984 DPFPRINTF(LOG_ERR, 2985 "%s: kif == NULL, @%d via %s", __func__, 2986 r->nr, r->rcv_ifname); 2987 return (0); 2988 } 2989 2990 return (pfi_kif_match(r->rcv_kif, kif)); 2991 } 2992 2993 void 2994 pf_tag_packet(struct mbuf *m, int tag, int rtableid) 2995 { 2996 if (tag > 0) 2997 m->m_pkthdr.pf.tag = tag; 2998 if (rtableid >= 0) 2999 m->m_pkthdr.ph_rtableid = (u_int)rtableid; 3000 } 3001 3002 void 3003 pf_step_into_anchor(int *depth, struct pf_ruleset **rs, 3004 struct pf_rule **r, struct pf_rule **a) 3005 { 3006 struct pf_anchor_stackframe *f; 3007 3008 if (*depth >= sizeof(pf_anchor_stack) / 3009 sizeof(pf_anchor_stack[0])) { 3010 log(LOG_ERR, "pf: anchor stack overflow\n"); 3011 *r = TAILQ_NEXT(*r, entries); 3012 return; 3013 } else if (a != NULL) 3014 *a = *r; 3015 f = pf_anchor_stack + (*depth)++; 3016 f->rs = *rs; 3017 f->r = *r; 3018 if ((*r)->anchor_wildcard) { 3019 f->parent = &(*r)->anchor->children; 3020 if ((f->child = RB_MIN(pf_anchor_node, f->parent)) == NULL) { 3021 *r = NULL; 3022 return; 3023 } 3024 *rs = &f->child->ruleset; 3025 } else { 3026 f->parent = NULL; 3027 f->child = NULL; 3028 *rs = &(*r)->anchor->ruleset; 3029 } 3030 *r = TAILQ_FIRST((*rs)->rules.active.ptr); 3031 } 3032 3033 int 3034 pf_step_out_of_anchor(int *depth, struct pf_ruleset **rs, 3035 struct pf_rule **r, struct pf_rule **a, int *match) 3036 { 3037 struct pf_anchor_stackframe *f; 3038 int quick = 0; 3039 3040 do { 3041 if (*depth <= 0) 3042 break; 3043 f = pf_anchor_stack + *depth - 1; 3044 if (f->parent != NULL && f->child != NULL) { 3045 f->child = RB_NEXT(pf_anchor_node, f->parent, f->child); 3046 if (f->child != NULL) { 3047 *rs = &f->child->ruleset; 3048 *r = TAILQ_FIRST((*rs)->rules.active.ptr); 3049 if (*r == NULL) 3050 continue; 3051 else 3052 break; 3053 } 3054 } 3055 (*depth)--; 3056 if (*depth == 0 && a != NULL) 3057 *a = NULL; 3058 else if (a != NULL) 3059 *a = f->r; 3060 *rs = f->rs; 3061 if (*match > *depth) { 3062 *match = *depth; 3063 if (f->r->quick) 3064 quick = 1; 3065 } 3066 *r = TAILQ_NEXT(f->r, entries); 3067 } while (*r == NULL); 3068 3069 return (quick); 3070 } 3071 3072 void 3073 pf_poolmask(struct pf_addr *naddr, struct pf_addr *raddr, 3074 struct pf_addr *rmask, struct pf_addr *saddr, sa_family_t af) 3075 { 3076 switch (af) { 3077 case AF_INET: 3078 naddr->addr32[0] = (raddr->addr32[0] & rmask->addr32[0]) | 3079 ((rmask->addr32[0] ^ 0xffffffff ) & saddr->addr32[0]); 3080 break; 3081 #ifdef INET6 3082 case AF_INET6: 3083 naddr->addr32[0] = (raddr->addr32[0] & rmask->addr32[0]) | 3084 ((rmask->addr32[0] ^ 0xffffffff ) & saddr->addr32[0]); 3085 naddr->addr32[1] = (raddr->addr32[1] & rmask->addr32[1]) | 3086 ((rmask->addr32[1] ^ 0xffffffff ) & saddr->addr32[1]); 3087 naddr->addr32[2] = (raddr->addr32[2] & rmask->addr32[2]) | 3088 ((rmask->addr32[2] ^ 0xffffffff ) & saddr->addr32[2]); 3089 naddr->addr32[3] = (raddr->addr32[3] & rmask->addr32[3]) | 3090 ((rmask->addr32[3] ^ 0xffffffff ) & saddr->addr32[3]); 3091 break; 3092 #endif /* INET6 */ 3093 default: 3094 unhandled_af(af); 3095 } 3096 } 3097 3098 void 3099 pf_addr_inc(struct pf_addr *addr, sa_family_t af) 3100 { 3101 switch (af) { 3102 case AF_INET: 3103 addr->addr32[0] = htonl(ntohl(addr->addr32[0]) + 1); 3104 break; 3105 #ifdef INET6 3106 case AF_INET6: 3107 if (addr->addr32[3] == 0xffffffff) { 3108 addr->addr32[3] = 0; 3109 if (addr->addr32[2] == 0xffffffff) { 3110 addr->addr32[2] = 0; 3111 if (addr->addr32[1] == 0xffffffff) { 3112 addr->addr32[1] = 0; 3113 addr->addr32[0] = 3114 htonl(ntohl(addr->addr32[0]) + 1); 3115 } else 3116 addr->addr32[1] = 3117 htonl(ntohl(addr->addr32[1]) + 1); 3118 } else 3119 addr->addr32[2] = 3120 htonl(ntohl(addr->addr32[2]) + 1); 3121 } else 3122 addr->addr32[3] = 3123 htonl(ntohl(addr->addr32[3]) + 1); 3124 break; 3125 #endif /* INET6 */ 3126 default: 3127 unhandled_af(af); 3128 } 3129 } 3130 3131 int 3132 pf_socket_lookup(struct pf_pdesc *pd) 3133 { 3134 struct pf_addr *saddr, *daddr; 3135 u_int16_t sport, dport; 3136 struct inpcbtable *tb; 3137 struct inpcb *inp; 3138 3139 pd->lookup.uid = UID_MAX; 3140 pd->lookup.gid = GID_MAX; 3141 pd->lookup.pid = NO_PID; 3142 switch (pd->virtual_proto) { 3143 case IPPROTO_TCP: 3144 sport = pd->hdr.tcp.th_sport; 3145 dport = pd->hdr.tcp.th_dport; 3146 tb = &tcbtable; 3147 break; 3148 case IPPROTO_UDP: 3149 sport = pd->hdr.udp.uh_sport; 3150 dport = pd->hdr.udp.uh_dport; 3151 tb = &udbtable; 3152 break; 3153 default: 3154 return (-1); 3155 } 3156 if (pd->dir == PF_IN) { 3157 saddr = pd->src; 3158 daddr = pd->dst; 3159 } else { 3160 u_int16_t p; 3161 3162 p = sport; 3163 sport = dport; 3164 dport = p; 3165 saddr = pd->dst; 3166 daddr = pd->src; 3167 } 3168 switch (pd->af) { 3169 case AF_INET: 3170 /* 3171 * Fails when rtable is changed while evaluating the ruleset 3172 * The socket looked up will not match the one hit in the end. 3173 */ 3174 inp = in_pcbhashlookup(tb, saddr->v4, sport, daddr->v4, dport, 3175 pd->rdomain); 3176 if (inp == NULL) { 3177 inp = in_pcblookup_listen(tb, daddr->v4, dport, 0, 3178 NULL, pd->rdomain); 3179 if (inp == NULL) 3180 return (-1); 3181 } 3182 break; 3183 #ifdef INET6 3184 case AF_INET6: 3185 inp = in6_pcbhashlookup(tb, &saddr->v6, sport, &daddr->v6, 3186 dport, pd->rdomain); 3187 if (inp == NULL) { 3188 inp = in6_pcblookup_listen(tb, &daddr->v6, dport, 0, 3189 NULL, pd->rdomain); 3190 if (inp == NULL) 3191 return (-1); 3192 } 3193 break; 3194 #endif /* INET6 */ 3195 default: 3196 unhandled_af(pd->af); 3197 } 3198 pd->lookup.uid = inp->inp_socket->so_euid; 3199 pd->lookup.gid = inp->inp_socket->so_egid; 3200 pd->lookup.pid = inp->inp_socket->so_cpid; 3201 return (1); 3202 } 3203 3204 u_int8_t 3205 pf_get_wscale(struct pf_pdesc *pd) 3206 { 3207 struct tcphdr *th = &pd->hdr.tcp; 3208 int hlen; 3209 u_int8_t hdr[60]; 3210 u_int8_t *opt, optlen; 3211 u_int8_t wscale = 0; 3212 3213 hlen = th->th_off << 2; /* hlen <= sizeof(hdr) */ 3214 if (hlen <= sizeof(struct tcphdr)) 3215 return (0); 3216 if (!pf_pull_hdr(pd->m, pd->off, hdr, hlen, NULL, NULL, pd->af)) 3217 return (0); 3218 opt = hdr + sizeof(struct tcphdr); 3219 hlen -= sizeof(struct tcphdr); 3220 while (hlen >= 3) { 3221 switch (*opt) { 3222 case TCPOPT_EOL: 3223 case TCPOPT_NOP: 3224 ++opt; 3225 --hlen; 3226 break; 3227 case TCPOPT_WINDOW: 3228 wscale = opt[2]; 3229 if (wscale > TCP_MAX_WINSHIFT) 3230 wscale = TCP_MAX_WINSHIFT; 3231 wscale |= PF_WSCALE_FLAG; 3232 /* FALLTHROUGH */ 3233 default: 3234 optlen = opt[1]; 3235 if (optlen < 2) 3236 optlen = 2; 3237 hlen -= optlen; 3238 opt += optlen; 3239 break; 3240 } 3241 } 3242 return (wscale); 3243 } 3244 3245 u_int16_t 3246 pf_get_mss(struct pf_pdesc *pd) 3247 { 3248 struct tcphdr *th = &pd->hdr.tcp; 3249 int hlen; 3250 u_int8_t hdr[60]; 3251 u_int8_t *opt, optlen; 3252 u_int16_t mss = tcp_mssdflt; 3253 3254 hlen = th->th_off << 2; /* hlen <= sizeof(hdr) */ 3255 if (hlen <= sizeof(struct tcphdr)) 3256 return (0); 3257 if (!pf_pull_hdr(pd->m, pd->off, hdr, hlen, NULL, NULL, pd->af)) 3258 return (0); 3259 opt = hdr + sizeof(struct tcphdr); 3260 hlen -= sizeof(struct tcphdr); 3261 while (hlen >= TCPOLEN_MAXSEG) { 3262 switch (*opt) { 3263 case TCPOPT_EOL: 3264 case TCPOPT_NOP: 3265 ++opt; 3266 --hlen; 3267 break; 3268 case TCPOPT_MAXSEG: 3269 memcpy(&mss, (opt + 2), 2); 3270 mss = ntohs(mss); 3271 /* FALLTHROUGH */ 3272 default: 3273 optlen = opt[1]; 3274 if (optlen < 2) 3275 optlen = 2; 3276 hlen -= optlen; 3277 opt += optlen; 3278 break; 3279 } 3280 } 3281 return (mss); 3282 } 3283 3284 u_int16_t 3285 pf_calc_mss(struct pf_addr *addr, sa_family_t af, int rtableid, u_int16_t offer) 3286 { 3287 struct ifnet *ifp; 3288 struct sockaddr_in *dst; 3289 #ifdef INET6 3290 struct sockaddr_in6 *dst6; 3291 #endif /* INET6 */ 3292 struct rtentry *rt = NULL; 3293 struct sockaddr_storage ss; 3294 int hlen; 3295 u_int16_t mss = tcp_mssdflt; 3296 3297 memset(&ss, 0, sizeof(ss)); 3298 3299 switch (af) { 3300 case AF_INET: 3301 hlen = sizeof(struct ip); 3302 dst = (struct sockaddr_in *)&ss; 3303 dst->sin_family = AF_INET; 3304 dst->sin_len = sizeof(*dst); 3305 dst->sin_addr = addr->v4; 3306 rt = rtalloc(sintosa(dst), 0, rtableid); 3307 break; 3308 #ifdef INET6 3309 case AF_INET6: 3310 hlen = sizeof(struct ip6_hdr); 3311 dst6 = (struct sockaddr_in6 *)&ss; 3312 dst6->sin6_family = AF_INET6; 3313 dst6->sin6_len = sizeof(*dst6); 3314 dst6->sin6_addr = addr->v6; 3315 rt = rtalloc(sin6tosa(dst6), 0, rtableid); 3316 break; 3317 #endif /* INET6 */ 3318 } 3319 3320 if (rt != NULL && (ifp = if_get(rt->rt_ifidx)) != NULL) { 3321 mss = ifp->if_mtu - hlen - sizeof(struct tcphdr); 3322 mss = max(tcp_mssdflt, mss); 3323 if_put(ifp); 3324 } 3325 rtfree(rt); 3326 mss = min(mss, offer); 3327 mss = max(mss, 64); /* sanity - at least max opt space */ 3328 return (mss); 3329 } 3330 3331 static __inline int 3332 pf_set_rt_ifp(struct pf_state *s, struct pf_addr *saddr, sa_family_t af) 3333 { 3334 struct pf_rule *r = s->rule.ptr; 3335 struct pf_src_node *sns[PF_SN_MAX]; 3336 int rv; 3337 3338 s->rt_kif = NULL; 3339 if (!r->rt) 3340 return (0); 3341 3342 bzero(sns, sizeof(sns)); 3343 switch (af) { 3344 case AF_INET: 3345 rv = pf_map_addr(AF_INET, r, saddr, &s->rt_addr, NULL, sns, 3346 &r->route, PF_SN_ROUTE); 3347 break; 3348 #ifdef INET6 3349 case AF_INET6: 3350 rv = pf_map_addr(AF_INET6, r, saddr, &s->rt_addr, NULL, sns, 3351 &r->route, PF_SN_ROUTE); 3352 break; 3353 #endif /* INET6 */ 3354 default: 3355 rv = 1; 3356 } 3357 3358 if (rv == 0) { 3359 s->rt_kif = r->route.kif; 3360 s->natrule.ptr = r; 3361 } 3362 3363 return (rv); 3364 } 3365 3366 u_int32_t 3367 pf_tcp_iss(struct pf_pdesc *pd) 3368 { 3369 SHA2_CTX ctx; 3370 union { 3371 uint8_t bytes[SHA512_DIGEST_LENGTH]; 3372 uint32_t words[1]; 3373 } digest; 3374 3375 if (pf_tcp_secret_init == 0) { 3376 arc4random_buf(pf_tcp_secret, sizeof(pf_tcp_secret)); 3377 SHA512Init(&pf_tcp_secret_ctx); 3378 SHA512Update(&pf_tcp_secret_ctx, pf_tcp_secret, 3379 sizeof(pf_tcp_secret)); 3380 pf_tcp_secret_init = 1; 3381 } 3382 ctx = pf_tcp_secret_ctx; 3383 3384 SHA512Update(&ctx, &pd->rdomain, sizeof(pd->rdomain)); 3385 SHA512Update(&ctx, &pd->hdr.tcp.th_sport, sizeof(u_short)); 3386 SHA512Update(&ctx, &pd->hdr.tcp.th_dport, sizeof(u_short)); 3387 switch (pd->af) { 3388 case AF_INET: 3389 SHA512Update(&ctx, &pd->src->v4, sizeof(struct in_addr)); 3390 SHA512Update(&ctx, &pd->dst->v4, sizeof(struct in_addr)); 3391 break; 3392 #ifdef INET6 3393 case AF_INET6: 3394 SHA512Update(&ctx, &pd->src->v6, sizeof(struct in6_addr)); 3395 SHA512Update(&ctx, &pd->dst->v6, sizeof(struct in6_addr)); 3396 break; 3397 #endif /* INET6 */ 3398 } 3399 SHA512Final(digest.bytes, &ctx); 3400 pf_tcp_iss_off += 4096; 3401 return (digest.words[0] + tcp_iss + pf_tcp_iss_off); 3402 } 3403 3404 void 3405 pf_rule_to_actions(struct pf_rule *r, struct pf_rule_actions *a) 3406 { 3407 if (r->qid) 3408 a->qid = r->qid; 3409 if (r->pqid) 3410 a->pqid = r->pqid; 3411 if (r->rtableid >= 0) 3412 a->rtableid = r->rtableid; 3413 #if NPFLOG > 0 3414 a->log |= r->log; 3415 #endif /* NPFLOG > 0 */ 3416 if (r->scrub_flags & PFSTATE_SETTOS) 3417 a->set_tos = r->set_tos; 3418 if (r->min_ttl) 3419 a->min_ttl = r->min_ttl; 3420 if (r->max_mss) 3421 a->max_mss = r->max_mss; 3422 a->flags |= (r->scrub_flags & (PFSTATE_NODF|PFSTATE_RANDOMID| 3423 PFSTATE_SETTOS|PFSTATE_SCRUB_TCP|PFSTATE_SETPRIO)); 3424 if (r->scrub_flags & PFSTATE_SETPRIO) { 3425 a->set_prio[0] = r->set_prio[0]; 3426 a->set_prio[1] = r->set_prio[1]; 3427 } 3428 } 3429 3430 #define PF_TEST_ATTRIB(t, a) \ 3431 do { \ 3432 if (t) { \ 3433 r = a; \ 3434 goto nextrule; \ 3435 } \ 3436 } while (0) 3437 3438 int 3439 pf_test_rule(struct pf_pdesc *pd, struct pf_rule **rm, struct pf_state **sm, 3440 struct pf_rule **am, struct pf_ruleset **rsm, u_short *reason) 3441 { 3442 struct pf_rule *r; 3443 struct pf_rule *nr = NULL; 3444 struct pf_rule *a = NULL; 3445 struct pf_ruleset *arsm = NULL; 3446 struct pf_ruleset *aruleset = NULL; 3447 struct pf_ruleset *ruleset = NULL; 3448 struct pf_rule_slist rules; 3449 struct pf_rule_item *ri; 3450 struct pf_src_node *sns[PF_SN_MAX]; 3451 struct pf_state_key *skw = NULL, *sks = NULL; 3452 struct pf_rule_actions act; 3453 int rewrite = 0; 3454 int tag = -1; 3455 int asd = 0; 3456 int match = 0; 3457 int state_icmp = 0, icmp_dir = 0; 3458 u_int16_t virtual_type, virtual_id; 3459 u_int8_t icmptype = 0, icmpcode = 0; 3460 int action = PF_DROP; 3461 3462 bzero(&act, sizeof(act)); 3463 bzero(sns, sizeof(sns)); 3464 act.rtableid = pd->rdomain; 3465 SLIST_INIT(&rules); 3466 3467 if (pd->dir == PF_IN && if_congested()) { 3468 REASON_SET(reason, PFRES_CONGEST); 3469 return (PF_DROP); 3470 } 3471 3472 switch (pd->virtual_proto) { 3473 case IPPROTO_ICMP: 3474 icmptype = pd->hdr.icmp.icmp_type; 3475 icmpcode = pd->hdr.icmp.icmp_code; 3476 state_icmp = pf_icmp_mapping(pd, icmptype, 3477 &icmp_dir, &virtual_id, &virtual_type); 3478 if (icmp_dir == PF_IN) { 3479 pd->osport = pd->nsport = virtual_id; 3480 pd->odport = pd->ndport = virtual_type; 3481 } else { 3482 pd->osport = pd->nsport = virtual_type; 3483 pd->odport = pd->ndport = virtual_id; 3484 } 3485 break; 3486 #ifdef INET6 3487 case IPPROTO_ICMPV6: 3488 icmptype = pd->hdr.icmp6.icmp6_type; 3489 icmpcode = pd->hdr.icmp6.icmp6_code; 3490 state_icmp = pf_icmp_mapping(pd, icmptype, 3491 &icmp_dir, &virtual_id, &virtual_type); 3492 if (icmp_dir == PF_IN) { 3493 pd->osport = pd->nsport = virtual_id; 3494 pd->odport = pd->ndport = virtual_type; 3495 } else { 3496 pd->osport = pd->nsport = virtual_type; 3497 pd->odport = pd->ndport = virtual_id; 3498 } 3499 break; 3500 #endif /* INET6 */ 3501 } 3502 3503 ruleset = &pf_main_ruleset; 3504 r = TAILQ_FIRST(pf_main_ruleset.rules.active.ptr); 3505 while (r != NULL) { 3506 if (r->rule_flag & PFRULE_EXPIRED) { 3507 r = TAILQ_NEXT(r, entries); 3508 goto nextrule; 3509 } 3510 r->evaluations++; 3511 PF_TEST_ATTRIB((pfi_kif_match(r->kif, pd->kif) == r->ifnot), 3512 r->skip[PF_SKIP_IFP].ptr); 3513 PF_TEST_ATTRIB((r->direction && r->direction != pd->dir), 3514 r->skip[PF_SKIP_DIR].ptr); 3515 PF_TEST_ATTRIB((r->onrdomain >= 0 && 3516 (r->onrdomain == pd->rdomain) == r->ifnot), 3517 r->skip[PF_SKIP_RDOM].ptr); 3518 PF_TEST_ATTRIB((r->af && r->af != pd->af), 3519 r->skip[PF_SKIP_AF].ptr); 3520 PF_TEST_ATTRIB((r->proto && r->proto != pd->proto), 3521 r->skip[PF_SKIP_PROTO].ptr); 3522 PF_TEST_ATTRIB((PF_MISMATCHAW(&r->src.addr, &pd->nsaddr, 3523 pd->naf, r->src.neg, pd->kif, act.rtableid)), 3524 r->skip[PF_SKIP_SRC_ADDR].ptr); 3525 PF_TEST_ATTRIB((PF_MISMATCHAW(&r->dst.addr, &pd->ndaddr, pd->af, 3526 r->dst.neg, NULL, act.rtableid)), 3527 r->skip[PF_SKIP_DST_ADDR].ptr); 3528 3529 switch (pd->virtual_proto) { 3530 case PF_VPROTO_FRAGMENT: 3531 /* tcp/udp only. port_op always 0 in other cases */ 3532 PF_TEST_ATTRIB((r->src.port_op || r->dst.port_op), 3533 TAILQ_NEXT(r, entries)); 3534 PF_TEST_ATTRIB((pd->proto == IPPROTO_TCP && r->flagset), 3535 TAILQ_NEXT(r, entries)); 3536 /* icmp only. type/code always 0 in other cases */ 3537 PF_TEST_ATTRIB((r->type || r->code), 3538 TAILQ_NEXT(r, entries)); 3539 /* tcp/udp only. {uid|gid}.op always 0 in other cases */ 3540 PF_TEST_ATTRIB((r->gid.op || r->uid.op), 3541 TAILQ_NEXT(r, entries)); 3542 break; 3543 3544 case IPPROTO_TCP: 3545 PF_TEST_ATTRIB(((r->flagset & pd->hdr.tcp.th_flags) != 3546 r->flags), 3547 TAILQ_NEXT(r, entries)); 3548 PF_TEST_ATTRIB((r->os_fingerprint != PF_OSFP_ANY && 3549 !pf_osfp_match(pf_osfp_fingerprint(pd), 3550 r->os_fingerprint)), 3551 TAILQ_NEXT(r, entries)); 3552 /* FALLTHROUGH */ 3553 3554 case IPPROTO_UDP: 3555 /* tcp/udp only. port_op always 0 in other cases */ 3556 PF_TEST_ATTRIB((r->src.port_op && 3557 !pf_match_port(r->src.port_op, r->src.port[0], 3558 r->src.port[1], pd->nsport)), 3559 r->skip[PF_SKIP_SRC_PORT].ptr); 3560 PF_TEST_ATTRIB((r->dst.port_op && 3561 !pf_match_port(r->dst.port_op, r->dst.port[0], 3562 r->dst.port[1], pd->ndport)), 3563 r->skip[PF_SKIP_DST_PORT].ptr); 3564 /* tcp/udp only. uid.op always 0 in other cases */ 3565 PF_TEST_ATTRIB((r->uid.op && (pd->lookup.done || 3566 (pd->lookup.done = 3567 pf_socket_lookup(pd), 1)) && 3568 !pf_match_uid(r->uid.op, r->uid.uid[0], 3569 r->uid.uid[1], pd->lookup.uid)), 3570 TAILQ_NEXT(r, entries)); 3571 /* tcp/udp only. gid.op always 0 in other cases */ 3572 PF_TEST_ATTRIB((r->gid.op && (pd->lookup.done || 3573 (pd->lookup.done = 3574 pf_socket_lookup(pd), 1)) && 3575 !pf_match_gid(r->gid.op, r->gid.gid[0], 3576 r->gid.gid[1], pd->lookup.gid)), 3577 TAILQ_NEXT(r, entries)); 3578 break; 3579 3580 case IPPROTO_ICMP: 3581 case IPPROTO_ICMPV6: 3582 /* icmp only. type always 0 in other cases */ 3583 PF_TEST_ATTRIB((r->type && r->type != icmptype + 1), 3584 TAILQ_NEXT(r, entries)); 3585 /* icmp only. type always 0 in other cases */ 3586 PF_TEST_ATTRIB((r->code && r->code != icmpcode + 1), 3587 TAILQ_NEXT(r, entries)); 3588 /* icmp only. don't create states on replies */ 3589 PF_TEST_ATTRIB((r->keep_state && !state_icmp && 3590 (r->rule_flag & PFRULE_STATESLOPPY) == 0 && 3591 icmp_dir != PF_IN), 3592 TAILQ_NEXT(r, entries)); 3593 break; 3594 3595 default: 3596 break; 3597 } 3598 3599 PF_TEST_ATTRIB((r->rule_flag & PFRULE_FRAGMENT && 3600 pd->virtual_proto != PF_VPROTO_FRAGMENT), 3601 TAILQ_NEXT(r, entries)); 3602 PF_TEST_ATTRIB((r->tos && !(r->tos == pd->tos)), 3603 TAILQ_NEXT(r, entries)); 3604 PF_TEST_ATTRIB((r->prob && 3605 r->prob <= arc4random_uniform(UINT_MAX - 1) + 1), 3606 TAILQ_NEXT(r, entries)); 3607 PF_TEST_ATTRIB((r->match_tag && !pf_match_tag(pd->m, r, &tag)), 3608 TAILQ_NEXT(r, entries)); 3609 PF_TEST_ATTRIB((r->rcv_kif && pf_match_rcvif(pd->m, r) == 3610 r->rcvifnot), 3611 TAILQ_NEXT(r, entries)); 3612 PF_TEST_ATTRIB((r->prio && (r->prio == PF_PRIO_ZERO ? 3613 0 : r->prio) != pd->m->m_pkthdr.pf.prio), 3614 TAILQ_NEXT(r, entries)); 3615 3616 /* FALLTHROUGH */ 3617 if (r->tag) 3618 tag = r->tag; 3619 if (r->anchor == NULL) { 3620 if (r->action == PF_MATCH) { 3621 if ((ri = pool_get(&pf_rule_item_pl, 3622 PR_NOWAIT)) == NULL) { 3623 REASON_SET(reason, PFRES_MEMORY); 3624 goto cleanup; 3625 } 3626 ri->r = r; 3627 /* order is irrelevant */ 3628 SLIST_INSERT_HEAD(&rules, ri, entry); 3629 pf_rule_to_actions(r, &act); 3630 if (r->rule_flag & PFRULE_AFTO) 3631 pd->naf = r->naf; 3632 if (pf_get_transaddr(r, pd, sns, &nr) == -1) { 3633 REASON_SET(reason, PFRES_TRANSLATE); 3634 goto cleanup; 3635 } 3636 #if NPFLOG > 0 3637 if (r->log) { 3638 REASON_SET(reason, PFRES_MATCH); 3639 PFLOG_PACKET(pd, *reason, r, a, ruleset, 3640 NULL); 3641 } 3642 #endif /* NPFLOG > 0 */ 3643 } else { 3644 match = asd; 3645 *rm = r; 3646 *am = a; 3647 *rsm = ruleset; 3648 arsm = aruleset; 3649 } 3650 3651 #if NPFLOG > 0 3652 if (act.log & PF_LOG_MATCHES) 3653 pf_log_matches(pd, r, a, ruleset, &rules); 3654 #endif /* NPFLOG > 0 */ 3655 3656 if (r->quick) 3657 break; 3658 r = TAILQ_NEXT(r, entries); 3659 } else { 3660 aruleset = ruleset; 3661 pf_step_into_anchor(&asd, &ruleset, &r, &a); 3662 } 3663 3664 nextrule: 3665 if (r == NULL && pf_step_out_of_anchor(&asd, &ruleset, 3666 &r, &a, &match)) 3667 break; 3668 } 3669 r = *rm; /* matching rule */ 3670 a = *am; /* rule that defines an anchor containing 'r' */ 3671 ruleset = *rsm; /* ruleset of the anchor defined by the rule 'a' */ 3672 aruleset = arsm;/* ruleset of the 'a' rule itself */ 3673 3674 /* apply actions for last matching pass/block rule */ 3675 pf_rule_to_actions(r, &act); 3676 if (r->rule_flag & PFRULE_AFTO) 3677 pd->naf = r->naf; 3678 if (pf_get_transaddr(r, pd, sns, &nr) == -1) { 3679 REASON_SET(reason, PFRES_TRANSLATE); 3680 goto cleanup; 3681 } 3682 REASON_SET(reason, PFRES_MATCH); 3683 3684 #if NPFLOG > 0 3685 if (r->log) 3686 PFLOG_PACKET(pd, *reason, r, a, ruleset, NULL); 3687 if (act.log & PF_LOG_MATCHES) 3688 pf_log_matches(pd, r, a, ruleset, &rules); 3689 #endif /* NPFLOG > 0 */ 3690 3691 if (pd->virtual_proto != PF_VPROTO_FRAGMENT && 3692 (r->action == PF_DROP) && 3693 ((r->rule_flag & PFRULE_RETURNRST) || 3694 (r->rule_flag & PFRULE_RETURNICMP) || 3695 (r->rule_flag & PFRULE_RETURN))) { 3696 if (pd->proto == IPPROTO_TCP && 3697 ((r->rule_flag & PFRULE_RETURNRST) || 3698 (r->rule_flag & PFRULE_RETURN)) && 3699 !(pd->hdr.tcp.th_flags & TH_RST)) { 3700 struct tcphdr *th = &pd->hdr.tcp; 3701 u_int32_t ack = ntohl(th->th_seq) + pd->p_len; 3702 3703 if (pf_check_tcp_cksum(pd->m, pd->off, 3704 pd->tot_len - pd->off, pd->af)) 3705 REASON_SET(reason, PFRES_PROTCKSUM); 3706 else { 3707 if (th->th_flags & TH_SYN) 3708 ack++; 3709 if (th->th_flags & TH_FIN) 3710 ack++; 3711 pf_send_tcp(r, pd->af, pd->dst, 3712 pd->src, th->th_dport, th->th_sport, 3713 ntohl(th->th_ack), ack, TH_RST|TH_ACK, 0, 0, 3714 r->return_ttl, 1, 0, pd->rdomain); 3715 } 3716 } else if ((pd->proto != IPPROTO_ICMP || 3717 ICMP_INFOTYPE(icmptype)) && pd->af == AF_INET && 3718 r->return_icmp) 3719 pf_send_icmp(pd->m, r->return_icmp >> 8, 3720 r->return_icmp & 255, pd->af, r, pd->rdomain); 3721 else if ((pd->proto != IPPROTO_ICMPV6 || 3722 (icmptype >= ICMP6_ECHO_REQUEST && 3723 icmptype != ND_REDIRECT)) && pd->af == AF_INET6 && 3724 r->return_icmp6) 3725 pf_send_icmp(pd->m, r->return_icmp6 >> 8, 3726 r->return_icmp6 & 255, pd->af, r, pd->rdomain); 3727 } 3728 3729 if (r->action == PF_DROP) 3730 goto cleanup; 3731 3732 pf_tag_packet(pd->m, tag, act.rtableid); 3733 if (act.rtableid >= 0 && 3734 rtable_l2(act.rtableid) != pd->rdomain) 3735 pd->destchg = 1; 3736 3737 if (r->action == PF_PASS && pd->badopts && ! r->allow_opts) { 3738 REASON_SET(reason, PFRES_IPOPTIONS); 3739 #if NPFLOG > 0 3740 pd->pflog |= PF_LOG_FORCE; 3741 #endif /* NPFLOG > 0 */ 3742 DPFPRINTF(LOG_NOTICE, "dropping packet with " 3743 "ip/ipv6 options in pf_test_rule()"); 3744 goto cleanup; 3745 } 3746 3747 action = PF_PASS; 3748 3749 if (pd->virtual_proto != PF_VPROTO_FRAGMENT 3750 && !state_icmp && r->keep_state) { 3751 3752 if (r->rule_flag & PFRULE_SRCTRACK && 3753 pf_insert_src_node(&sns[PF_SN_NONE], r, PF_SN_NONE, pd->af, 3754 pd->src, NULL) != 0) { 3755 REASON_SET(reason, PFRES_SRCLIMIT); 3756 goto cleanup; 3757 } 3758 3759 if (r->max_states && (r->states_cur >= r->max_states)) { 3760 pf_status.lcounters[LCNT_STATES]++; 3761 REASON_SET(reason, PFRES_MAXSTATES); 3762 goto cleanup; 3763 } 3764 3765 action = pf_create_state(pd, r, a, nr, &skw, &sks, &rewrite, 3766 sm, tag, &rules, &act, sns); 3767 3768 if (action != PF_PASS) 3769 goto cleanup; 3770 if (sks != skw) { 3771 struct pf_state_key *sk; 3772 3773 if (pd->dir == PF_IN) 3774 sk = sks; 3775 else 3776 sk = skw; 3777 rewrite += pf_translate(pd, 3778 &sk->addr[pd->af == pd->naf ? pd->sidx : pd->didx], 3779 sk->port[pd->af == pd->naf ? pd->sidx : pd->didx], 3780 &sk->addr[pd->af == pd->naf ? pd->didx : pd->sidx], 3781 sk->port[pd->af == pd->naf ? pd->didx : pd->sidx], 3782 virtual_type, icmp_dir); 3783 } 3784 3785 #ifdef INET6 3786 if (rewrite && skw->af != sks->af) 3787 action = PF_AFRT; 3788 #endif /* INET6 */ 3789 3790 } else { 3791 while ((ri = SLIST_FIRST(&rules))) { 3792 SLIST_REMOVE_HEAD(&rules, entry); 3793 pool_put(&pf_rule_item_pl, ri); 3794 } 3795 } 3796 3797 /* copy back packet headers if needed */ 3798 if (rewrite && pd->hdrlen) { 3799 m_copyback(pd->m, pd->off, pd->hdrlen, &pd->hdr, M_NOWAIT); 3800 } 3801 3802 #if NPFSYNC > 0 3803 if (*sm != NULL && !ISSET((*sm)->state_flags, PFSTATE_NOSYNC) && 3804 pd->dir == PF_OUT && pfsync_up()) { 3805 /* 3806 * We want the state created, but we dont 3807 * want to send this in case a partner 3808 * firewall has to know about it to allow 3809 * replies through it. 3810 */ 3811 if (pfsync_defer(*sm, pd->m)) 3812 return (PF_DEFER); 3813 } 3814 #endif /* NPFSYNC > 0 */ 3815 3816 if (r->rule_flag & PFRULE_ONCE) { 3817 r->rule_flag |= PFRULE_EXPIRED; 3818 r->exptime = time_second; 3819 SLIST_INSERT_HEAD(&pf_rule_gcl, r, gcle); 3820 } 3821 3822 return (action); 3823 3824 cleanup: 3825 while ((ri = SLIST_FIRST(&rules))) { 3826 SLIST_REMOVE_HEAD(&rules, entry); 3827 pool_put(&pf_rule_item_pl, ri); 3828 } 3829 3830 return (action); 3831 } 3832 3833 static __inline int 3834 pf_create_state(struct pf_pdesc *pd, struct pf_rule *r, struct pf_rule *a, 3835 struct pf_rule *nr, struct pf_state_key **skw, struct pf_state_key **sks, 3836 int *rewrite, struct pf_state **sm, int tag, struct pf_rule_slist *rules, 3837 struct pf_rule_actions *act, struct pf_src_node *sns[PF_SN_MAX]) 3838 { 3839 struct pf_state *s = NULL; 3840 struct tcphdr *th = &pd->hdr.tcp; 3841 u_int16_t mss = tcp_mssdflt; 3842 u_short reason; 3843 u_int i; 3844 3845 s = pool_get(&pf_state_pl, PR_NOWAIT | PR_ZERO); 3846 if (s == NULL) { 3847 REASON_SET(&reason, PFRES_MEMORY); 3848 goto csfailed; 3849 } 3850 s->rule.ptr = r; 3851 s->anchor.ptr = a; 3852 s->natrule.ptr = nr; 3853 if (r->allow_opts) 3854 s->state_flags |= PFSTATE_ALLOWOPTS; 3855 if (r->rule_flag & PFRULE_STATESLOPPY) 3856 s->state_flags |= PFSTATE_SLOPPY; 3857 if (r->rule_flag & PFRULE_PFLOW) 3858 s->state_flags |= PFSTATE_PFLOW; 3859 #if NPFLOG > 0 3860 s->log = act->log & PF_LOG_ALL; 3861 #endif /* NPFLOG > 0 */ 3862 s->qid = act->qid; 3863 s->pqid = act->pqid; 3864 s->rtableid[pd->didx] = act->rtableid; 3865 s->rtableid[pd->sidx] = -1; /* return traffic is routed normally */ 3866 s->min_ttl = act->min_ttl; 3867 s->set_tos = act->set_tos; 3868 s->max_mss = act->max_mss; 3869 s->state_flags |= act->flags; 3870 #if NPFSYNC > 0 3871 s->sync_state = PFSYNC_S_NONE; 3872 #endif /* NPFSYNC > 0 */ 3873 s->set_prio[0] = act->set_prio[0]; 3874 s->set_prio[1] = act->set_prio[1]; 3875 SLIST_INIT(&s->src_nodes); 3876 3877 switch (pd->proto) { 3878 case IPPROTO_TCP: 3879 s->src.seqlo = ntohl(th->th_seq); 3880 s->src.seqhi = s->src.seqlo + pd->p_len + 1; 3881 if ((th->th_flags & (TH_SYN|TH_ACK)) == TH_SYN && 3882 r->keep_state == PF_STATE_MODULATE) { 3883 /* Generate sequence number modulator */ 3884 if ((s->src.seqdiff = pf_tcp_iss(pd) - s->src.seqlo) == 3885 0) 3886 s->src.seqdiff = 1; 3887 pf_patch_32(pd, 3888 &th->th_seq, htonl(s->src.seqlo + s->src.seqdiff)); 3889 *rewrite = 1; 3890 } else 3891 s->src.seqdiff = 0; 3892 if (th->th_flags & TH_SYN) { 3893 s->src.seqhi++; 3894 s->src.wscale = pf_get_wscale(pd); 3895 } 3896 s->src.max_win = MAX(ntohs(th->th_win), 1); 3897 if (s->src.wscale & PF_WSCALE_MASK) { 3898 /* Remove scale factor from initial window */ 3899 int win = s->src.max_win; 3900 win += 1 << (s->src.wscale & PF_WSCALE_MASK); 3901 s->src.max_win = (win - 1) >> 3902 (s->src.wscale & PF_WSCALE_MASK); 3903 } 3904 if (th->th_flags & TH_FIN) 3905 s->src.seqhi++; 3906 s->dst.seqhi = 1; 3907 s->dst.max_win = 1; 3908 s->src.state = TCPS_SYN_SENT; 3909 s->dst.state = TCPS_CLOSED; 3910 s->timeout = PFTM_TCP_FIRST_PACKET; 3911 break; 3912 case IPPROTO_UDP: 3913 s->src.state = PFUDPS_SINGLE; 3914 s->dst.state = PFUDPS_NO_TRAFFIC; 3915 s->timeout = PFTM_UDP_FIRST_PACKET; 3916 break; 3917 case IPPROTO_ICMP: 3918 #ifdef INET6 3919 case IPPROTO_ICMPV6: 3920 #endif /* INET6 */ 3921 s->timeout = PFTM_ICMP_FIRST_PACKET; 3922 break; 3923 default: 3924 s->src.state = PFOTHERS_SINGLE; 3925 s->dst.state = PFOTHERS_NO_TRAFFIC; 3926 s->timeout = PFTM_OTHER_FIRST_PACKET; 3927 } 3928 3929 s->creation = time_uptime; 3930 s->expire = time_uptime; 3931 3932 if (pd->proto == IPPROTO_TCP) { 3933 if (s->state_flags & PFSTATE_SCRUB_TCP && 3934 pf_normalize_tcp_init(pd, &s->src)) { 3935 REASON_SET(&reason, PFRES_MEMORY); 3936 goto csfailed; 3937 } 3938 if (s->state_flags & PFSTATE_SCRUB_TCP && s->src.scrub && 3939 pf_normalize_tcp_stateful(pd, &reason, s, &s->src, &s->dst, 3940 rewrite)) { 3941 /* This really shouldn't happen!!! */ 3942 DPFPRINTF(LOG_ERR, 3943 "%s: tcp normalize failed on first pkt", __func__); 3944 goto csfailed; 3945 } 3946 } 3947 s->direction = pd->dir; 3948 3949 if (pf_state_key_setup(pd, skw, sks, act->rtableid)) { 3950 REASON_SET(&reason, PFRES_MEMORY); 3951 goto csfailed; 3952 } 3953 3954 for (i = 0; i < PF_SN_MAX; i++) 3955 if (sns[i] != NULL) { 3956 struct pf_sn_item *sni; 3957 3958 sni = pool_get(&pf_sn_item_pl, PR_NOWAIT); 3959 if (sni == NULL) { 3960 REASON_SET(&reason, PFRES_MEMORY); 3961 goto csfailed; 3962 } 3963 sni->sn = sns[i]; 3964 SLIST_INSERT_HEAD(&s->src_nodes, sni, next); 3965 sni->sn->states++; 3966 } 3967 3968 if (pf_set_rt_ifp(s, pd->src, (*skw)->af) != 0) { 3969 REASON_SET(&reason, PFRES_NOROUTE); 3970 goto csfailed; 3971 } 3972 3973 if (pf_state_insert(BOUND_IFACE(r, pd->kif), skw, sks, s)) { 3974 pf_detach_state(s); 3975 *sks = *skw = NULL; 3976 REASON_SET(&reason, PFRES_STATEINS); 3977 goto csfailed; 3978 } else 3979 *sm = s; 3980 3981 /* 3982 * Make state responsible for rules it binds here. 3983 */ 3984 memcpy(&s->match_rules, rules, sizeof(s->match_rules)); 3985 bzero(rules, sizeof(*rules)); 3986 STATE_INC_COUNTERS(s); 3987 3988 if (tag > 0) { 3989 pf_tag_ref(tag); 3990 s->tag = tag; 3991 } 3992 if (pd->proto == IPPROTO_TCP && (th->th_flags & (TH_SYN|TH_ACK)) == 3993 TH_SYN && r->keep_state == PF_STATE_SYNPROXY) { 3994 int rtid = pd->rdomain; 3995 if (act->rtableid >= 0) 3996 rtid = act->rtableid; 3997 s->src.state = PF_TCPS_PROXY_SRC; 3998 s->src.seqhi = arc4random(); 3999 /* Find mss option */ 4000 mss = pf_get_mss(pd); 4001 mss = pf_calc_mss(pd->src, pd->af, rtid, mss); 4002 mss = pf_calc_mss(pd->dst, pd->af, rtid, mss); 4003 s->src.mss = mss; 4004 pf_send_tcp(r, pd->af, pd->dst, pd->src, th->th_dport, 4005 th->th_sport, s->src.seqhi, ntohl(th->th_seq) + 1, 4006 TH_SYN|TH_ACK, 0, s->src.mss, 0, 1, 0, pd->rdomain); 4007 REASON_SET(&reason, PFRES_SYNPROXY); 4008 return (PF_SYNPROXY_DROP); 4009 } 4010 4011 return (PF_PASS); 4012 4013 csfailed: 4014 if (s) { 4015 pf_normalize_tcp_cleanup(s); /* safe even w/o init */ 4016 pf_src_tree_remove_state(s); 4017 pool_put(&pf_state_pl, s); 4018 } 4019 4020 for (i = 0; i < PF_SN_MAX; i++) 4021 if (sns[i] != NULL) 4022 pf_remove_src_node(sns[i]); 4023 4024 return (PF_DROP); 4025 } 4026 4027 int 4028 pf_translate(struct pf_pdesc *pd, struct pf_addr *saddr, u_int16_t sport, 4029 struct pf_addr *daddr, u_int16_t dport, u_int16_t virtual_type, 4030 int icmp_dir) 4031 { 4032 /* 4033 * when called from bpf_mtap_pflog, there are extra constraints: 4034 * -mbuf is faked, m_data is the bpf buffer 4035 * -pd is not fully set up 4036 */ 4037 int rewrite = 0; 4038 int afto = pd->af != pd->naf; 4039 4040 if (afto || PF_ANEQ(daddr, pd->dst, pd->af)) 4041 pd->destchg = 1; 4042 4043 switch (pd->proto) { 4044 case IPPROTO_TCP: /* FALLTHROUGH */ 4045 case IPPROTO_UDP: 4046 rewrite += pf_patch_16(pd, pd->sport, sport); 4047 rewrite += pf_patch_16(pd, pd->dport, dport); 4048 break; 4049 4050 case IPPROTO_ICMP: 4051 /* pf_translate() is also used when logging invalid packets */ 4052 if (pd->af != AF_INET) 4053 return (0); 4054 4055 if (afto) { 4056 #ifdef INET6 4057 if (pf_translate_icmp_af(pd, AF_INET6, &pd->hdr.icmp)) 4058 return (0); 4059 pd->proto = IPPROTO_ICMPV6; 4060 rewrite = 1; 4061 #endif /* INET6 */ 4062 } 4063 if (virtual_type == htons(ICMP_ECHO)) { 4064 u_int16_t icmpid = (icmp_dir == PF_IN) ? sport : dport; 4065 rewrite += pf_patch_16(pd, 4066 &pd->hdr.icmp.icmp_id, icmpid); 4067 } 4068 break; 4069 4070 #ifdef INET6 4071 case IPPROTO_ICMPV6: 4072 /* pf_translate() is also used when logging invalid packets */ 4073 if (pd->af != AF_INET6) 4074 return (0); 4075 4076 if (afto) { 4077 if (pf_translate_icmp_af(pd, AF_INET, &pd->hdr.icmp6)) 4078 return (0); 4079 pd->proto = IPPROTO_ICMP; 4080 rewrite = 1; 4081 } 4082 if (virtual_type == htons(ICMP6_ECHO_REQUEST)) { 4083 u_int16_t icmpid = (icmp_dir == PF_IN) ? sport : dport; 4084 rewrite += pf_patch_16(pd, 4085 &pd->hdr.icmp6.icmp6_id, icmpid); 4086 } 4087 break; 4088 #endif /* INET6 */ 4089 } 4090 4091 if (!afto) { 4092 rewrite += pf_translate_a(pd, pd->src, saddr); 4093 rewrite += pf_translate_a(pd, pd->dst, daddr); 4094 } 4095 4096 return (rewrite); 4097 } 4098 4099 int 4100 pf_tcp_track_full(struct pf_pdesc *pd, struct pf_state_peer *src, 4101 struct pf_state_peer *dst, struct pf_state **state, u_short *reason, 4102 int *copyback) 4103 { 4104 struct tcphdr *th = &pd->hdr.tcp; 4105 u_int16_t win = ntohs(th->th_win); 4106 u_int32_t ack, end, data_end, seq, orig_seq; 4107 u_int8_t sws, dws; 4108 int ackskew; 4109 4110 if (src->wscale && dst->wscale && !(th->th_flags & TH_SYN)) { 4111 sws = src->wscale & PF_WSCALE_MASK; 4112 dws = dst->wscale & PF_WSCALE_MASK; 4113 } else 4114 sws = dws = 0; 4115 4116 /* 4117 * Sequence tracking algorithm from Guido van Rooij's paper: 4118 * http://www.madison-gurkha.com/publications/tcp_filtering/ 4119 * tcp_filtering.ps 4120 */ 4121 4122 orig_seq = seq = ntohl(th->th_seq); 4123 if (src->seqlo == 0) { 4124 /* First packet from this end. Set its state */ 4125 4126 if (((*state)->state_flags & PFSTATE_SCRUB_TCP || dst->scrub) && 4127 src->scrub == NULL) { 4128 if (pf_normalize_tcp_init(pd, src)) { 4129 REASON_SET(reason, PFRES_MEMORY); 4130 return (PF_DROP); 4131 } 4132 } 4133 4134 /* Deferred generation of sequence number modulator */ 4135 if (dst->seqdiff && !src->seqdiff) { 4136 /* use random iss for the TCP server */ 4137 while ((src->seqdiff = arc4random() - seq) == 0) 4138 continue; 4139 ack = ntohl(th->th_ack) - dst->seqdiff; 4140 pf_patch_32(pd, &th->th_seq, htonl(seq + src->seqdiff)); 4141 pf_patch_32(pd, &th->th_ack, htonl(ack)); 4142 *copyback = 1; 4143 } else { 4144 ack = ntohl(th->th_ack); 4145 } 4146 4147 end = seq + pd->p_len; 4148 if (th->th_flags & TH_SYN) { 4149 end++; 4150 if (dst->wscale & PF_WSCALE_FLAG) { 4151 src->wscale = pf_get_wscale(pd); 4152 if (src->wscale & PF_WSCALE_FLAG) { 4153 /* Remove scale factor from initial 4154 * window */ 4155 sws = src->wscale & PF_WSCALE_MASK; 4156 win = ((u_int32_t)win + (1 << sws) - 1) 4157 >> sws; 4158 dws = dst->wscale & PF_WSCALE_MASK; 4159 } else { 4160 /* fixup other window */ 4161 dst->max_win = MIN(TCP_MAXWIN, 4162 (u_int32_t)dst->max_win << 4163 (dst->wscale & PF_WSCALE_MASK)); 4164 /* in case of a retrans SYN|ACK */ 4165 dst->wscale = 0; 4166 } 4167 } 4168 } 4169 data_end = end; 4170 if (th->th_flags & TH_FIN) 4171 end++; 4172 4173 src->seqlo = seq; 4174 if (src->state < TCPS_SYN_SENT) 4175 src->state = TCPS_SYN_SENT; 4176 4177 /* 4178 * May need to slide the window (seqhi may have been set by 4179 * the crappy stack check or if we picked up the connection 4180 * after establishment) 4181 */ 4182 if (src->seqhi == 1 || 4183 SEQ_GEQ(end + MAX(1, dst->max_win << dws), src->seqhi)) 4184 src->seqhi = end + MAX(1, dst->max_win << dws); 4185 if (win > src->max_win) 4186 src->max_win = win; 4187 4188 } else { 4189 ack = ntohl(th->th_ack) - dst->seqdiff; 4190 if (src->seqdiff) { 4191 /* Modulate sequence numbers */ 4192 pf_patch_32(pd, &th->th_seq, htonl(seq + src->seqdiff)); 4193 pf_patch_32(pd, &th->th_ack, htonl(ack)); 4194 *copyback = 1; 4195 } 4196 end = seq + pd->p_len; 4197 if (th->th_flags & TH_SYN) 4198 end++; 4199 data_end = end; 4200 if (th->th_flags & TH_FIN) 4201 end++; 4202 } 4203 4204 if ((th->th_flags & TH_ACK) == 0) { 4205 /* Let it pass through the ack skew check */ 4206 ack = dst->seqlo; 4207 } else if ((ack == 0 && 4208 (th->th_flags & (TH_ACK|TH_RST)) == (TH_ACK|TH_RST)) || 4209 /* broken tcp stacks do not set ack */ 4210 (dst->state < TCPS_SYN_SENT)) { 4211 /* 4212 * Many stacks (ours included) will set the ACK number in an 4213 * FIN|ACK if the SYN times out -- no sequence to ACK. 4214 */ 4215 ack = dst->seqlo; 4216 } 4217 4218 if (seq == end) { 4219 /* Ease sequencing restrictions on no data packets */ 4220 seq = src->seqlo; 4221 data_end = end = seq; 4222 } 4223 4224 ackskew = dst->seqlo - ack; 4225 4226 4227 /* 4228 * Need to demodulate the sequence numbers in any TCP SACK options 4229 * (Selective ACK). We could optionally validate the SACK values 4230 * against the current ACK window, either forwards or backwards, but 4231 * I'm not confident that SACK has been implemented properly 4232 * everywhere. It wouldn't surprise me if several stacks accidently 4233 * SACK too far backwards of previously ACKed data. There really aren't 4234 * any security implications of bad SACKing unless the target stack 4235 * doesn't validate the option length correctly. Someone trying to 4236 * spoof into a TCP connection won't bother blindly sending SACK 4237 * options anyway. 4238 */ 4239 if (dst->seqdiff && (th->th_off << 2) > sizeof(struct tcphdr)) { 4240 if (pf_modulate_sack(pd, dst)) 4241 *copyback = 1; 4242 } 4243 4244 4245 #define MAXACKWINDOW (0xffff + 1500) /* 1500 is an arbitrary fudge factor */ 4246 if (SEQ_GEQ(src->seqhi, data_end) && 4247 /* Last octet inside other's window space */ 4248 SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)) && 4249 /* Retrans: not more than one window back */ 4250 (ackskew >= -MAXACKWINDOW) && 4251 /* Acking not more than one reassembled fragment backwards */ 4252 (ackskew <= (MAXACKWINDOW << sws)) && 4253 /* Acking not more than one window forward */ 4254 ((th->th_flags & TH_RST) == 0 || orig_seq == src->seqlo || 4255 (orig_seq == src->seqlo + 1) || (orig_seq + 1 == src->seqlo))) { 4256 /* Require an exact/+1 sequence match on resets when possible */ 4257 4258 if (dst->scrub || src->scrub) { 4259 if (pf_normalize_tcp_stateful(pd, reason, *state, src, 4260 dst, copyback)) 4261 return (PF_DROP); 4262 } 4263 4264 /* update max window */ 4265 if (src->max_win < win) 4266 src->max_win = win; 4267 /* synchronize sequencing */ 4268 if (SEQ_GT(end, src->seqlo)) 4269 src->seqlo = end; 4270 /* slide the window of what the other end can send */ 4271 if (SEQ_GEQ(ack + (win << sws), dst->seqhi)) 4272 dst->seqhi = ack + MAX((win << sws), 1); 4273 4274 /* update states */ 4275 if (th->th_flags & TH_SYN) 4276 if (src->state < TCPS_SYN_SENT) 4277 src->state = TCPS_SYN_SENT; 4278 if (th->th_flags & TH_FIN) 4279 if (src->state < TCPS_CLOSING) 4280 src->state = TCPS_CLOSING; 4281 if (th->th_flags & TH_ACK) { 4282 if (dst->state == TCPS_SYN_SENT) { 4283 dst->state = TCPS_ESTABLISHED; 4284 if (src->state == TCPS_ESTABLISHED && 4285 !SLIST_EMPTY(&(*state)->src_nodes) && 4286 pf_src_connlimit(state)) { 4287 REASON_SET(reason, PFRES_SRCLIMIT); 4288 return (PF_DROP); 4289 } 4290 } else if (dst->state == TCPS_CLOSING) 4291 dst->state = TCPS_FIN_WAIT_2; 4292 } 4293 if (th->th_flags & TH_RST) 4294 src->state = dst->state = TCPS_TIME_WAIT; 4295 4296 /* update expire time */ 4297 (*state)->expire = time_uptime; 4298 if (src->state >= TCPS_FIN_WAIT_2 && 4299 dst->state >= TCPS_FIN_WAIT_2) 4300 (*state)->timeout = PFTM_TCP_CLOSED; 4301 else if (src->state >= TCPS_CLOSING && 4302 dst->state >= TCPS_CLOSING) 4303 (*state)->timeout = PFTM_TCP_FIN_WAIT; 4304 else if (src->state < TCPS_ESTABLISHED || 4305 dst->state < TCPS_ESTABLISHED) 4306 (*state)->timeout = PFTM_TCP_OPENING; 4307 else if (src->state >= TCPS_CLOSING || 4308 dst->state >= TCPS_CLOSING) 4309 (*state)->timeout = PFTM_TCP_CLOSING; 4310 else 4311 (*state)->timeout = PFTM_TCP_ESTABLISHED; 4312 4313 /* Fall through to PASS packet */ 4314 } else if ((dst->state < TCPS_SYN_SENT || 4315 dst->state >= TCPS_FIN_WAIT_2 || 4316 src->state >= TCPS_FIN_WAIT_2) && 4317 SEQ_GEQ(src->seqhi + MAXACKWINDOW, data_end) && 4318 /* Within a window forward of the originating packet */ 4319 SEQ_GEQ(seq, src->seqlo - MAXACKWINDOW)) { 4320 /* Within a window backward of the originating packet */ 4321 4322 /* 4323 * This currently handles three situations: 4324 * 1) Stupid stacks will shotgun SYNs before their peer 4325 * replies. 4326 * 2) When PF catches an already established stream (the 4327 * firewall rebooted, the state table was flushed, routes 4328 * changed...) 4329 * 3) Packets get funky immediately after the connection 4330 * closes (this should catch Solaris spurious ACK|FINs 4331 * that web servers like to spew after a close) 4332 * 4333 * This must be a little more careful than the above code 4334 * since packet floods will also be caught here. We don't 4335 * update the TTL here to mitigate the damage of a packet 4336 * flood and so the same code can handle awkward establishment 4337 * and a loosened connection close. 4338 * In the establishment case, a correct peer response will 4339 * validate the connection, go through the normal state code 4340 * and keep updating the state TTL. 4341 */ 4342 4343 if (pf_status.debug >= LOG_NOTICE) { 4344 log(LOG_NOTICE, "pf: loose state match: "); 4345 pf_print_state(*state); 4346 pf_print_flags(th->th_flags); 4347 addlog(" seq=%u (%u) ack=%u len=%u ackskew=%d " 4348 "pkts=%llu:%llu dir=%s,%s\n", seq, orig_seq, ack, 4349 pd->p_len, ackskew, (*state)->packets[0], 4350 (*state)->packets[1], 4351 pd->dir == PF_IN ? "in" : "out", 4352 pd->dir == (*state)->direction ? "fwd" : "rev"); 4353 } 4354 4355 if (dst->scrub || src->scrub) { 4356 if (pf_normalize_tcp_stateful(pd, reason, *state, src, 4357 dst, copyback)) 4358 return (PF_DROP); 4359 } 4360 4361 /* update max window */ 4362 if (src->max_win < win) 4363 src->max_win = win; 4364 /* synchronize sequencing */ 4365 if (SEQ_GT(end, src->seqlo)) 4366 src->seqlo = end; 4367 /* slide the window of what the other end can send */ 4368 if (SEQ_GEQ(ack + (win << sws), dst->seqhi)) 4369 dst->seqhi = ack + MAX((win << sws), 1); 4370 4371 /* 4372 * Cannot set dst->seqhi here since this could be a shotgunned 4373 * SYN and not an already established connection. 4374 */ 4375 if (th->th_flags & TH_FIN) 4376 if (src->state < TCPS_CLOSING) 4377 src->state = TCPS_CLOSING; 4378 if (th->th_flags & TH_RST) 4379 src->state = dst->state = TCPS_TIME_WAIT; 4380 4381 /* Fall through to PASS packet */ 4382 } else { 4383 if ((*state)->dst.state == TCPS_SYN_SENT && 4384 (*state)->src.state == TCPS_SYN_SENT) { 4385 /* Send RST for state mismatches during handshake */ 4386 if (!(th->th_flags & TH_RST)) 4387 pf_send_tcp((*state)->rule.ptr, pd->af, 4388 pd->dst, pd->src, th->th_dport, 4389 th->th_sport, ntohl(th->th_ack), 0, 4390 TH_RST, 0, 0, 4391 (*state)->rule.ptr->return_ttl, 1, 0, 4392 pd->rdomain); 4393 src->seqlo = 0; 4394 src->seqhi = 1; 4395 src->max_win = 1; 4396 } else if (pf_status.debug >= LOG_NOTICE) { 4397 log(LOG_NOTICE, "pf: BAD state: "); 4398 pf_print_state(*state); 4399 pf_print_flags(th->th_flags); 4400 addlog(" seq=%u (%u) ack=%u len=%u ackskew=%d " 4401 "pkts=%llu:%llu dir=%s,%s\n", 4402 seq, orig_seq, ack, pd->p_len, ackskew, 4403 (*state)->packets[0], (*state)->packets[1], 4404 pd->dir == PF_IN ? "in" : "out", 4405 pd->dir == (*state)->direction ? "fwd" : "rev"); 4406 addlog("pf: State failure on: %c %c %c %c | %c %c\n", 4407 SEQ_GEQ(src->seqhi, data_end) ? ' ' : '1', 4408 SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)) ? 4409 ' ': '2', 4410 (ackskew >= -MAXACKWINDOW) ? ' ' : '3', 4411 (ackskew <= (MAXACKWINDOW << sws)) ? ' ' : '4', 4412 SEQ_GEQ(src->seqhi + MAXACKWINDOW, data_end) ? 4413 ' ' :'5', 4414 SEQ_GEQ(seq, src->seqlo - MAXACKWINDOW) ?' ' :'6'); 4415 } 4416 REASON_SET(reason, PFRES_BADSTATE); 4417 return (PF_DROP); 4418 } 4419 4420 return (PF_PASS); 4421 } 4422 4423 int 4424 pf_tcp_track_sloppy(struct pf_pdesc *pd, struct pf_state_peer *src, 4425 struct pf_state_peer *dst, struct pf_state **state, u_short *reason) 4426 { 4427 struct tcphdr *th = &pd->hdr.tcp; 4428 4429 if (th->th_flags & TH_SYN) 4430 if (src->state < TCPS_SYN_SENT) 4431 src->state = TCPS_SYN_SENT; 4432 if (th->th_flags & TH_FIN) 4433 if (src->state < TCPS_CLOSING) 4434 src->state = TCPS_CLOSING; 4435 if (th->th_flags & TH_ACK) { 4436 if (dst->state == TCPS_SYN_SENT) { 4437 dst->state = TCPS_ESTABLISHED; 4438 if (src->state == TCPS_ESTABLISHED && 4439 !SLIST_EMPTY(&(*state)->src_nodes) && 4440 pf_src_connlimit(state)) { 4441 REASON_SET(reason, PFRES_SRCLIMIT); 4442 return (PF_DROP); 4443 } 4444 } else if (dst->state == TCPS_CLOSING) { 4445 dst->state = TCPS_FIN_WAIT_2; 4446 } else if (src->state == TCPS_SYN_SENT && 4447 dst->state < TCPS_SYN_SENT) { 4448 /* 4449 * Handle a special sloppy case where we only see one 4450 * half of the connection. If there is a ACK after 4451 * the initial SYN without ever seeing a packet from 4452 * the destination, set the connection to established. 4453 */ 4454 dst->state = src->state = TCPS_ESTABLISHED; 4455 if (!SLIST_EMPTY(&(*state)->src_nodes) && 4456 pf_src_connlimit(state)) { 4457 REASON_SET(reason, PFRES_SRCLIMIT); 4458 return (PF_DROP); 4459 } 4460 } else if (src->state == TCPS_CLOSING && 4461 dst->state == TCPS_ESTABLISHED && 4462 dst->seqlo == 0) { 4463 /* 4464 * Handle the closing of half connections where we 4465 * don't see the full bidirectional FIN/ACK+ACK 4466 * handshake. 4467 */ 4468 dst->state = TCPS_CLOSING; 4469 } 4470 } 4471 if (th->th_flags & TH_RST) 4472 src->state = dst->state = TCPS_TIME_WAIT; 4473 4474 /* update expire time */ 4475 (*state)->expire = time_uptime; 4476 if (src->state >= TCPS_FIN_WAIT_2 && 4477 dst->state >= TCPS_FIN_WAIT_2) 4478 (*state)->timeout = PFTM_TCP_CLOSED; 4479 else if (src->state >= TCPS_CLOSING && 4480 dst->state >= TCPS_CLOSING) 4481 (*state)->timeout = PFTM_TCP_FIN_WAIT; 4482 else if (src->state < TCPS_ESTABLISHED || 4483 dst->state < TCPS_ESTABLISHED) 4484 (*state)->timeout = PFTM_TCP_OPENING; 4485 else if (src->state >= TCPS_CLOSING || 4486 dst->state >= TCPS_CLOSING) 4487 (*state)->timeout = PFTM_TCP_CLOSING; 4488 else 4489 (*state)->timeout = PFTM_TCP_ESTABLISHED; 4490 4491 return (PF_PASS); 4492 } 4493 4494 static __inline int 4495 pf_synproxy(struct pf_pdesc *pd, struct pf_state **state, u_short *reason) 4496 { 4497 struct pf_state_key *sk = (*state)->key[pd->didx]; 4498 4499 if ((*state)->src.state == PF_TCPS_PROXY_SRC) { 4500 struct tcphdr *th = &pd->hdr.tcp; 4501 4502 if (pd->dir != (*state)->direction) { 4503 REASON_SET(reason, PFRES_SYNPROXY); 4504 return (PF_SYNPROXY_DROP); 4505 } 4506 if (th->th_flags & TH_SYN) { 4507 if (ntohl(th->th_seq) != (*state)->src.seqlo) { 4508 REASON_SET(reason, PFRES_SYNPROXY); 4509 return (PF_DROP); 4510 } 4511 pf_send_tcp((*state)->rule.ptr, pd->af, pd->dst, 4512 pd->src, th->th_dport, th->th_sport, 4513 (*state)->src.seqhi, ntohl(th->th_seq) + 1, 4514 TH_SYN|TH_ACK, 0, (*state)->src.mss, 0, 1, 4515 0, pd->rdomain); 4516 REASON_SET(reason, PFRES_SYNPROXY); 4517 return (PF_SYNPROXY_DROP); 4518 } else if ((th->th_flags & (TH_ACK|TH_RST|TH_FIN)) != TH_ACK || 4519 (ntohl(th->th_ack) != (*state)->src.seqhi + 1) || 4520 (ntohl(th->th_seq) != (*state)->src.seqlo + 1)) { 4521 REASON_SET(reason, PFRES_SYNPROXY); 4522 return (PF_DROP); 4523 } else if (!SLIST_EMPTY(&(*state)->src_nodes) && 4524 pf_src_connlimit(state)) { 4525 REASON_SET(reason, PFRES_SRCLIMIT); 4526 return (PF_DROP); 4527 } else 4528 (*state)->src.state = PF_TCPS_PROXY_DST; 4529 } 4530 if ((*state)->src.state == PF_TCPS_PROXY_DST) { 4531 struct tcphdr *th = &pd->hdr.tcp; 4532 4533 if (pd->dir == (*state)->direction) { 4534 if (((th->th_flags & (TH_SYN|TH_ACK)) != TH_ACK) || 4535 (ntohl(th->th_ack) != (*state)->src.seqhi + 1) || 4536 (ntohl(th->th_seq) != (*state)->src.seqlo + 1)) { 4537 REASON_SET(reason, PFRES_SYNPROXY); 4538 return (PF_DROP); 4539 } 4540 (*state)->src.max_win = MAX(ntohs(th->th_win), 1); 4541 if ((*state)->dst.seqhi == 1) 4542 (*state)->dst.seqhi = arc4random(); 4543 pf_send_tcp((*state)->rule.ptr, pd->af, 4544 &sk->addr[pd->sidx], &sk->addr[pd->didx], 4545 sk->port[pd->sidx], sk->port[pd->didx], 4546 (*state)->dst.seqhi, 0, TH_SYN, 0, 4547 (*state)->src.mss, 0, 0, (*state)->tag, 4548 sk->rdomain); 4549 REASON_SET(reason, PFRES_SYNPROXY); 4550 return (PF_SYNPROXY_DROP); 4551 } else if (((th->th_flags & (TH_SYN|TH_ACK)) != 4552 (TH_SYN|TH_ACK)) || 4553 (ntohl(th->th_ack) != (*state)->dst.seqhi + 1)) { 4554 REASON_SET(reason, PFRES_SYNPROXY); 4555 return (PF_DROP); 4556 } else { 4557 (*state)->dst.max_win = MAX(ntohs(th->th_win), 1); 4558 (*state)->dst.seqlo = ntohl(th->th_seq); 4559 pf_send_tcp((*state)->rule.ptr, pd->af, pd->dst, 4560 pd->src, th->th_dport, th->th_sport, 4561 ntohl(th->th_ack), ntohl(th->th_seq) + 1, 4562 TH_ACK, (*state)->src.max_win, 0, 0, 0, 4563 (*state)->tag, pd->rdomain); 4564 pf_send_tcp((*state)->rule.ptr, pd->af, 4565 &sk->addr[pd->sidx], &sk->addr[pd->didx], 4566 sk->port[pd->sidx], sk->port[pd->didx], 4567 (*state)->src.seqhi + 1, (*state)->src.seqlo + 1, 4568 TH_ACK, (*state)->dst.max_win, 0, 0, 1, 4569 0, sk->rdomain); 4570 (*state)->src.seqdiff = (*state)->dst.seqhi - 4571 (*state)->src.seqlo; 4572 (*state)->dst.seqdiff = (*state)->src.seqhi - 4573 (*state)->dst.seqlo; 4574 (*state)->src.seqhi = (*state)->src.seqlo + 4575 (*state)->dst.max_win; 4576 (*state)->dst.seqhi = (*state)->dst.seqlo + 4577 (*state)->src.max_win; 4578 (*state)->src.wscale = (*state)->dst.wscale = 0; 4579 (*state)->src.state = (*state)->dst.state = 4580 TCPS_ESTABLISHED; 4581 REASON_SET(reason, PFRES_SYNPROXY); 4582 return (PF_SYNPROXY_DROP); 4583 } 4584 } 4585 return (PF_PASS); 4586 } 4587 4588 int 4589 pf_test_state(struct pf_pdesc *pd, struct pf_state **state, u_short *reason) 4590 { 4591 struct pf_state_key_cmp key; 4592 int copyback = 0; 4593 struct pf_state_peer *src, *dst; 4594 int action = PF_PASS; 4595 struct inpcb *inp; 4596 4597 key.af = pd->af; 4598 key.proto = pd->virtual_proto; 4599 key.rdomain = pd->rdomain; 4600 PF_ACPY(&key.addr[pd->sidx], pd->src, key.af); 4601 PF_ACPY(&key.addr[pd->didx], pd->dst, key.af); 4602 key.port[pd->sidx] = pd->osport; 4603 key.port[pd->didx] = pd->odport; 4604 inp = pd->m->m_pkthdr.pf.inp; 4605 4606 STATE_LOOKUP(pd->kif, &key, pd->dir, *state, pd->m); 4607 4608 if (pd->dir == (*state)->direction) { 4609 src = &(*state)->src; 4610 dst = &(*state)->dst; 4611 } else { 4612 src = &(*state)->dst; 4613 dst = &(*state)->src; 4614 } 4615 4616 switch (pd->virtual_proto) { 4617 case IPPROTO_TCP: 4618 if ((action = pf_synproxy(pd, state, reason)) != PF_PASS) 4619 return (action); 4620 if ((pd->hdr.tcp.th_flags & (TH_SYN|TH_ACK)) == TH_SYN) { 4621 4622 if (dst->state >= TCPS_FIN_WAIT_2 && 4623 src->state >= TCPS_FIN_WAIT_2) { 4624 if (pf_status.debug >= LOG_NOTICE) { 4625 log(LOG_NOTICE, "pf: state reuse "); 4626 pf_print_state(*state); 4627 pf_print_flags(pd->hdr.tcp.th_flags); 4628 addlog("\n"); 4629 } 4630 /* XXX make sure it's the same direction ?? */ 4631 (*state)->src.state = TCPS_CLOSED; 4632 (*state)->dst.state = TCPS_CLOSED; 4633 pf_remove_state(*state); 4634 *state = NULL; 4635 pd->m->m_pkthdr.pf.inp = inp; 4636 return (PF_DROP); 4637 } else if (dst->state >= TCPS_ESTABLISHED && 4638 src->state >= TCPS_ESTABLISHED) { 4639 /* 4640 * SYN matches existing state??? 4641 * Typically happens when sender boots up after 4642 * sudden panic. Certain protocols (NFSv3) are 4643 * always using same port numbers. Challenge 4644 * ACK enables all parties (firewall and peers) 4645 * to get in sync again. 4646 */ 4647 pf_send_challenge_ack(pd, *state, src, dst); 4648 return (PF_DROP); 4649 } 4650 } 4651 4652 if ((*state)->state_flags & PFSTATE_SLOPPY) { 4653 if (pf_tcp_track_sloppy(pd, src, dst, state, reason) == 4654 PF_DROP) 4655 return (PF_DROP); 4656 } else { 4657 int ret; 4658 4659 if (PF_REVERSED_KEY((*state)->key, pd->af)) 4660 ret = pf_tcp_track_full(pd, dst, src, state, 4661 reason, ©back); 4662 else 4663 ret = pf_tcp_track_full(pd, src, dst, state, 4664 reason, ©back); 4665 if (ret == PF_DROP) 4666 return (PF_DROP); 4667 } 4668 break; 4669 case IPPROTO_UDP: 4670 /* update states */ 4671 if (src->state < PFUDPS_SINGLE) 4672 src->state = PFUDPS_SINGLE; 4673 if (dst->state == PFUDPS_SINGLE) 4674 dst->state = PFUDPS_MULTIPLE; 4675 4676 /* update expire time */ 4677 (*state)->expire = time_uptime; 4678 if (src->state == PFUDPS_MULTIPLE && 4679 dst->state == PFUDPS_MULTIPLE) 4680 (*state)->timeout = PFTM_UDP_MULTIPLE; 4681 else 4682 (*state)->timeout = PFTM_UDP_SINGLE; 4683 break; 4684 default: 4685 /* update states */ 4686 if (src->state < PFOTHERS_SINGLE) 4687 src->state = PFOTHERS_SINGLE; 4688 if (dst->state == PFOTHERS_SINGLE) 4689 dst->state = PFOTHERS_MULTIPLE; 4690 4691 /* update expire time */ 4692 (*state)->expire = time_uptime; 4693 if (src->state == PFOTHERS_MULTIPLE && 4694 dst->state == PFOTHERS_MULTIPLE) 4695 (*state)->timeout = PFTM_OTHER_MULTIPLE; 4696 else 4697 (*state)->timeout = PFTM_OTHER_SINGLE; 4698 break; 4699 } 4700 4701 /* translate source/destination address, if necessary */ 4702 if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) { 4703 struct pf_state_key *nk; 4704 int afto, sidx, didx; 4705 4706 if (PF_REVERSED_KEY((*state)->key, pd->af)) 4707 nk = (*state)->key[pd->sidx]; 4708 else 4709 nk = (*state)->key[pd->didx]; 4710 4711 afto = pd->af != nk->af; 4712 sidx = afto ? pd->didx : pd->sidx; 4713 didx = afto ? pd->sidx : pd->didx; 4714 4715 #ifdef INET6 4716 if (afto) { 4717 PF_ACPY(&pd->nsaddr, &nk->addr[sidx], nk->af); 4718 PF_ACPY(&pd->ndaddr, &nk->addr[didx], nk->af); 4719 pd->naf = nk->af; 4720 action = PF_AFRT; 4721 } 4722 #endif /* INET6 */ 4723 4724 if (!afto) 4725 pf_translate_a(pd, pd->src, &nk->addr[sidx]); 4726 4727 if (pd->sport != NULL) 4728 pf_patch_16(pd, pd->sport, nk->port[sidx]); 4729 4730 if (afto || PF_ANEQ(pd->dst, &nk->addr[didx], pd->af) || 4731 pd->rdomain != nk->rdomain) 4732 pd->destchg = 1; 4733 4734 if (!afto) 4735 pf_translate_a(pd, pd->dst, &nk->addr[didx]); 4736 4737 if (pd->dport != NULL) 4738 pf_patch_16(pd, pd->dport, nk->port[didx]); 4739 4740 pd->m->m_pkthdr.ph_rtableid = nk->rdomain; 4741 copyback = 1; 4742 } 4743 4744 if (copyback && pd->hdrlen > 0) { 4745 m_copyback(pd->m, pd->off, pd->hdrlen, &pd->hdr, M_NOWAIT); 4746 } 4747 4748 return (action); 4749 } 4750 4751 int 4752 pf_icmp_state_lookup(struct pf_pdesc *pd, struct pf_state_key_cmp *key, 4753 struct pf_state **state, u_int16_t icmpid, u_int16_t type, 4754 int icmp_dir, int *iidx, int multi, int inner) 4755 { 4756 int direction; 4757 4758 key->af = pd->af; 4759 key->proto = pd->proto; 4760 key->rdomain = pd->rdomain; 4761 if (icmp_dir == PF_IN) { 4762 *iidx = pd->sidx; 4763 key->port[pd->sidx] = icmpid; 4764 key->port[pd->didx] = type; 4765 } else { 4766 *iidx = pd->didx; 4767 key->port[pd->sidx] = type; 4768 key->port[pd->didx] = icmpid; 4769 } 4770 4771 if (pf_state_key_addr_setup(pd, key, pd->sidx, pd->src, pd->didx, 4772 pd->dst, pd->af, multi)) 4773 return (PF_DROP); 4774 4775 STATE_LOOKUP(pd->kif, key, pd->dir, *state, pd->m); 4776 4777 if ((*state)->state_flags & PFSTATE_SLOPPY) 4778 return (-1); 4779 4780 /* Is this ICMP message flowing in right direction? */ 4781 if ((*state)->key[PF_SK_WIRE]->af != (*state)->key[PF_SK_STACK]->af) 4782 direction = (pd->af == (*state)->key[PF_SK_WIRE]->af) ? 4783 PF_IN : PF_OUT; 4784 else 4785 direction = (*state)->direction; 4786 if ((((!inner && direction == pd->dir) || 4787 (inner && direction != pd->dir)) ? 4788 PF_IN : PF_OUT) != icmp_dir) { 4789 if (pf_status.debug >= LOG_NOTICE) { 4790 log(LOG_NOTICE, 4791 "pf: icmp type %d in wrong direction (%d): ", 4792 ntohs(type), icmp_dir); 4793 pf_print_state(*state); 4794 addlog("\n"); 4795 } 4796 return (PF_DROP); 4797 } 4798 return (-1); 4799 } 4800 4801 int 4802 pf_test_state_icmp(struct pf_pdesc *pd, struct pf_state **state, 4803 u_short *reason) 4804 { 4805 u_int16_t virtual_id, virtual_type; 4806 u_int8_t icmptype; 4807 int icmp_dir, iidx, ret, copyback = 0; 4808 4809 struct pf_state_key_cmp key; 4810 4811 switch (pd->proto) { 4812 case IPPROTO_ICMP: 4813 icmptype = pd->hdr.icmp.icmp_type; 4814 break; 4815 #ifdef INET6 4816 case IPPROTO_ICMPV6: 4817 icmptype = pd->hdr.icmp6.icmp6_type; 4818 break; 4819 #endif /* INET6 */ 4820 default: 4821 panic("unhandled proto %d", pd->proto); 4822 } 4823 4824 if (pf_icmp_mapping(pd, icmptype, &icmp_dir, &virtual_id, 4825 &virtual_type) == 0) { 4826 /* 4827 * ICMP query/reply message not related to a TCP/UDP packet. 4828 * Search for an ICMP state. 4829 */ 4830 ret = pf_icmp_state_lookup(pd, &key, state, 4831 virtual_id, virtual_type, icmp_dir, &iidx, 4832 0, 0); 4833 /* IPv6? try matching a multicast address */ 4834 if (ret == PF_DROP && pd->af == AF_INET6 && icmp_dir == PF_OUT) 4835 ret = pf_icmp_state_lookup(pd, &key, state, virtual_id, 4836 virtual_type, icmp_dir, &iidx, 1, 0); 4837 if (ret >= 0) 4838 return (ret); 4839 4840 (*state)->expire = time_uptime; 4841 (*state)->timeout = PFTM_ICMP_ERROR_REPLY; 4842 4843 /* translate source/destination address, if necessary */ 4844 if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) { 4845 struct pf_state_key *nk; 4846 int afto, sidx, didx; 4847 4848 if (PF_REVERSED_KEY((*state)->key, pd->af)) 4849 nk = (*state)->key[pd->sidx]; 4850 else 4851 nk = (*state)->key[pd->didx]; 4852 4853 afto = pd->af != nk->af; 4854 sidx = afto ? pd->didx : pd->sidx; 4855 didx = afto ? pd->sidx : pd->didx; 4856 iidx = afto ? !iidx : iidx; 4857 #ifdef INET6 4858 if (afto) { 4859 PF_ACPY(&pd->nsaddr, &nk->addr[sidx], nk->af); 4860 PF_ACPY(&pd->ndaddr, &nk->addr[didx], nk->af); 4861 pd->naf = nk->af; 4862 } 4863 #endif /* INET6 */ 4864 if (!afto) { 4865 pf_translate_a(pd, pd->src, &nk->addr[sidx]); 4866 pf_translate_a(pd, pd->dst, &nk->addr[didx]); 4867 } 4868 4869 if (pd->rdomain != nk->rdomain) 4870 pd->destchg = 1; 4871 if (!afto && PF_ANEQ(pd->dst, 4872 &nk->addr[didx], pd->af)) 4873 pd->destchg = 1; 4874 pd->m->m_pkthdr.ph_rtableid = nk->rdomain; 4875 4876 switch (pd->af) { 4877 case AF_INET: 4878 #ifdef INET6 4879 if (afto) { 4880 if (pf_translate_icmp_af(pd, AF_INET6, 4881 &pd->hdr.icmp)) 4882 return (PF_DROP); 4883 pd->proto = IPPROTO_ICMPV6; 4884 } 4885 #endif /* INET6 */ 4886 pf_patch_16(pd, 4887 &pd->hdr.icmp.icmp_id, nk->port[iidx]); 4888 4889 m_copyback(pd->m, pd->off, ICMP_MINLEN, 4890 &pd->hdr.icmp, M_NOWAIT); 4891 copyback = 1; 4892 break; 4893 #ifdef INET6 4894 case AF_INET6: 4895 if (afto) { 4896 if (pf_translate_icmp_af(pd, AF_INET, 4897 &pd->hdr.icmp6)) 4898 return (PF_DROP); 4899 pd->proto = IPPROTO_ICMP; 4900 } 4901 4902 pf_patch_16(pd, 4903 &pd->hdr.icmp6.icmp6_id, nk->port[iidx]); 4904 4905 m_copyback(pd->m, pd->off, 4906 sizeof(struct icmp6_hdr), &pd->hdr.icmp6, 4907 M_NOWAIT); 4908 copyback = 1; 4909 break; 4910 #endif /* INET6 */ 4911 } 4912 #ifdef INET6 4913 if (afto) 4914 return (PF_AFRT); 4915 #endif /* INET6 */ 4916 } 4917 } else { 4918 /* 4919 * ICMP error message in response to a TCP/UDP packet. 4920 * Extract the inner TCP/UDP header and search for that state. 4921 */ 4922 struct pf_pdesc pd2; 4923 struct ip h2; 4924 #ifdef INET6 4925 struct ip6_hdr h2_6; 4926 #endif /* INET6 */ 4927 int ipoff2; 4928 4929 /* Initialize pd2 fields valid for both packets with pd. */ 4930 bzero(&pd2, sizeof(pd2)); 4931 pd2.af = pd->af; 4932 pd2.dir = pd->dir; 4933 pd2.kif = pd->kif; 4934 pd2.m = pd->m; 4935 pd2.rdomain = pd->rdomain; 4936 /* Payload packet is from the opposite direction. */ 4937 pd2.sidx = (pd2.dir == PF_IN) ? 1 : 0; 4938 pd2.didx = (pd2.dir == PF_IN) ? 0 : 1; 4939 switch (pd->af) { 4940 case AF_INET: 4941 /* offset of h2 in mbuf chain */ 4942 ipoff2 = pd->off + ICMP_MINLEN; 4943 4944 if (!pf_pull_hdr(pd2.m, ipoff2, &h2, sizeof(h2), 4945 NULL, reason, pd2.af)) { 4946 DPFPRINTF(LOG_NOTICE, 4947 "ICMP error message too short (ip)"); 4948 return (PF_DROP); 4949 } 4950 /* 4951 * ICMP error messages don't refer to non-first 4952 * fragments 4953 */ 4954 if (h2.ip_off & htons(IP_OFFMASK)) { 4955 REASON_SET(reason, PFRES_FRAG); 4956 return (PF_DROP); 4957 } 4958 4959 /* offset of protocol header that follows h2 */ 4960 pd2.off = ipoff2 + (h2.ip_hl << 2); 4961 4962 pd2.proto = h2.ip_p; 4963 pd2.tot_len = ntohs(h2.ip_len); 4964 pd2.src = (struct pf_addr *)&h2.ip_src; 4965 pd2.dst = (struct pf_addr *)&h2.ip_dst; 4966 break; 4967 #ifdef INET6 4968 case AF_INET6: 4969 ipoff2 = pd->off + sizeof(struct icmp6_hdr); 4970 4971 if (!pf_pull_hdr(pd2.m, ipoff2, &h2_6, sizeof(h2_6), 4972 NULL, reason, pd2.af)) { 4973 DPFPRINTF(LOG_NOTICE, 4974 "ICMP error message too short (ip6)"); 4975 return (PF_DROP); 4976 } 4977 4978 pd2.off = ipoff2; 4979 if (pf_walk_header6(&pd2, &h2_6, reason) != PF_PASS) 4980 return (PF_DROP); 4981 4982 pd2.tot_len = ntohs(h2_6.ip6_plen) + 4983 sizeof(struct ip6_hdr); 4984 pd2.src = (struct pf_addr *)&h2_6.ip6_src; 4985 pd2.dst = (struct pf_addr *)&h2_6.ip6_dst; 4986 break; 4987 #endif /* INET6 */ 4988 default: 4989 unhandled_af(pd->af); 4990 } 4991 4992 switch (pd2.proto) { 4993 case IPPROTO_TCP: { 4994 struct tcphdr *th = &pd2.hdr.tcp; 4995 u_int32_t seq; 4996 struct pf_state_peer *src, *dst; 4997 u_int8_t dws; 4998 4999 /* 5000 * Only the first 8 bytes of the TCP header can be 5001 * expected. Don't access any TCP header fields after 5002 * th_seq, an ackskew test is not possible. 5003 */ 5004 if (!pf_pull_hdr(pd2.m, pd2.off, th, 8, NULL, reason, 5005 pd2.af)) { 5006 DPFPRINTF(LOG_NOTICE, 5007 "ICMP error message too short (tcp)"); 5008 return (PF_DROP); 5009 } 5010 5011 key.af = pd2.af; 5012 key.proto = IPPROTO_TCP; 5013 key.rdomain = pd2.rdomain; 5014 PF_ACPY(&key.addr[pd2.sidx], pd2.src, key.af); 5015 PF_ACPY(&key.addr[pd2.didx], pd2.dst, key.af); 5016 key.port[pd2.sidx] = th->th_sport; 5017 key.port[pd2.didx] = th->th_dport; 5018 5019 STATE_LOOKUP(pd2.kif, &key, pd2.dir, *state, pd2.m); 5020 5021 if (pd2.dir == (*state)->direction) { 5022 if (PF_REVERSED_KEY((*state)->key, pd->af)) { 5023 src = &(*state)->src; 5024 dst = &(*state)->dst; 5025 } else { 5026 src = &(*state)->dst; 5027 dst = &(*state)->src; 5028 } 5029 } else { 5030 if (PF_REVERSED_KEY((*state)->key, pd->af)) { 5031 src = &(*state)->dst; 5032 dst = &(*state)->src; 5033 } else { 5034 src = &(*state)->src; 5035 dst = &(*state)->dst; 5036 } 5037 } 5038 5039 if (src->wscale && dst->wscale) 5040 dws = dst->wscale & PF_WSCALE_MASK; 5041 else 5042 dws = 0; 5043 5044 /* Demodulate sequence number */ 5045 seq = ntohl(th->th_seq) - src->seqdiff; 5046 if (src->seqdiff) { 5047 pf_patch_32(pd, &th->th_seq, htonl(seq)); 5048 copyback = 1; 5049 } 5050 5051 if (!((*state)->state_flags & PFSTATE_SLOPPY) && 5052 (!SEQ_GEQ(src->seqhi, seq) || !SEQ_GEQ(seq, 5053 src->seqlo - (dst->max_win << dws)))) { 5054 if (pf_status.debug >= LOG_NOTICE) { 5055 log(LOG_NOTICE, 5056 "pf: BAD ICMP %d:%d ", 5057 icmptype, pd->hdr.icmp.icmp_code); 5058 pf_print_host(pd->src, 0, pd->af); 5059 addlog(" -> "); 5060 pf_print_host(pd->dst, 0, pd->af); 5061 addlog(" state: "); 5062 pf_print_state(*state); 5063 addlog(" seq=%u\n", seq); 5064 } 5065 REASON_SET(reason, PFRES_BADSTATE); 5066 return (PF_DROP); 5067 } else { 5068 if (pf_status.debug >= LOG_DEBUG) { 5069 log(LOG_DEBUG, 5070 "pf: OK ICMP %d:%d ", 5071 icmptype, pd->hdr.icmp.icmp_code); 5072 pf_print_host(pd->src, 0, pd->af); 5073 addlog(" -> "); 5074 pf_print_host(pd->dst, 0, pd->af); 5075 addlog(" state: "); 5076 pf_print_state(*state); 5077 addlog(" seq=%u\n", seq); 5078 } 5079 } 5080 5081 /* translate source/destination address, if necessary */ 5082 if ((*state)->key[PF_SK_WIRE] != 5083 (*state)->key[PF_SK_STACK]) { 5084 struct pf_state_key *nk; 5085 int afto, sidx, didx; 5086 5087 if (PF_REVERSED_KEY((*state)->key, pd->af)) 5088 nk = (*state)->key[pd->sidx]; 5089 else 5090 nk = (*state)->key[pd->didx]; 5091 5092 afto = pd->af != nk->af; 5093 sidx = afto ? pd2.didx : pd2.sidx; 5094 didx = afto ? pd2.sidx : pd2.didx; 5095 5096 #ifdef INET6 5097 if (afto) { 5098 if (pf_translate_icmp_af(pd, nk->af, 5099 &pd->hdr.icmp)) 5100 return (PF_DROP); 5101 m_copyback(pd->m, pd->off, 5102 sizeof(struct icmp6_hdr), 5103 &pd->hdr.icmp6, M_NOWAIT); 5104 if (pf_change_icmp_af(pd->m, ipoff2, 5105 pd, &pd2, &nk->addr[sidx], 5106 &nk->addr[didx], pd->af, nk->af)) 5107 return (PF_DROP); 5108 if (nk->af == AF_INET) 5109 pd->proto = IPPROTO_ICMP; 5110 else 5111 pd->proto = IPPROTO_ICMPV6; 5112 pd->m->m_pkthdr.ph_rtableid = 5113 nk->rdomain; 5114 pd->destchg = 1; 5115 PF_ACPY(&pd->nsaddr, 5116 &nk->addr[pd2.sidx], nk->af); 5117 PF_ACPY(&pd->ndaddr, 5118 &nk->addr[pd2.didx], nk->af); 5119 pd->naf = nk->af; 5120 5121 pf_patch_16(pd, 5122 &th->th_sport, nk->port[sidx]); 5123 pf_patch_16(pd, 5124 &th->th_dport, nk->port[didx]); 5125 5126 m_copyback(pd2.m, pd2.off, 8, th, 5127 M_NOWAIT); 5128 return (PF_AFRT); 5129 } 5130 #endif /* INET6 */ 5131 if (PF_ANEQ(pd2.src, 5132 &nk->addr[pd2.sidx], pd2.af) || 5133 nk->port[pd2.sidx] != th->th_sport) 5134 pf_translate_icmp(pd, pd2.src, 5135 &th->th_sport, pd->dst, 5136 &nk->addr[pd2.sidx], 5137 nk->port[pd2.sidx]); 5138 5139 if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], 5140 pd2.af) || pd2.rdomain != nk->rdomain) 5141 pd->destchg = 1; 5142 pd->m->m_pkthdr.ph_rtableid = nk->rdomain; 5143 5144 if (PF_ANEQ(pd2.dst, 5145 &nk->addr[pd2.didx], pd2.af) || 5146 nk->port[pd2.didx] != th->th_dport) 5147 pf_translate_icmp(pd, pd2.dst, 5148 &th->th_dport, pd->src, 5149 &nk->addr[pd2.didx], 5150 nk->port[pd2.didx]); 5151 copyback = 1; 5152 } 5153 5154 if (copyback) { 5155 switch (pd2.af) { 5156 case AF_INET: 5157 m_copyback(pd->m, pd->off, ICMP_MINLEN, 5158 &pd->hdr.icmp, M_NOWAIT); 5159 m_copyback(pd2.m, ipoff2, sizeof(h2), 5160 &h2, M_NOWAIT); 5161 break; 5162 #ifdef INET6 5163 case AF_INET6: 5164 m_copyback(pd->m, pd->off, 5165 sizeof(struct icmp6_hdr), 5166 &pd->hdr.icmp6, M_NOWAIT); 5167 m_copyback(pd2.m, ipoff2, sizeof(h2_6), 5168 &h2_6, M_NOWAIT); 5169 break; 5170 #endif /* INET6 */ 5171 } 5172 m_copyback(pd2.m, pd2.off, 8, th, M_NOWAIT); 5173 } 5174 break; 5175 } 5176 case IPPROTO_UDP: { 5177 struct udphdr *uh = &pd2.hdr.udp; 5178 5179 if (!pf_pull_hdr(pd2.m, pd2.off, uh, sizeof(*uh), 5180 NULL, reason, pd2.af)) { 5181 DPFPRINTF(LOG_NOTICE, 5182 "ICMP error message too short (udp)"); 5183 return (PF_DROP); 5184 } 5185 5186 key.af = pd2.af; 5187 key.proto = IPPROTO_UDP; 5188 key.rdomain = pd2.rdomain; 5189 PF_ACPY(&key.addr[pd2.sidx], pd2.src, key.af); 5190 PF_ACPY(&key.addr[pd2.didx], pd2.dst, key.af); 5191 key.port[pd2.sidx] = uh->uh_sport; 5192 key.port[pd2.didx] = uh->uh_dport; 5193 5194 STATE_LOOKUP(pd2.kif, &key, pd2.dir, *state, pd2.m); 5195 5196 /* translate source/destination address, if necessary */ 5197 if ((*state)->key[PF_SK_WIRE] != 5198 (*state)->key[PF_SK_STACK]) { 5199 struct pf_state_key *nk; 5200 int afto, sidx, didx; 5201 5202 if (PF_REVERSED_KEY((*state)->key, pd->af)) 5203 nk = (*state)->key[pd->sidx]; 5204 else 5205 nk = (*state)->key[pd->didx]; 5206 5207 afto = pd->af != nk->af; 5208 sidx = afto ? pd2.didx : pd2.sidx; 5209 didx = afto ? pd2.sidx : pd2.didx; 5210 5211 #ifdef INET6 5212 if (afto) { 5213 if (pf_translate_icmp_af(pd, nk->af, 5214 &pd->hdr.icmp)) 5215 return (PF_DROP); 5216 m_copyback(pd->m, pd->off, 5217 sizeof(struct icmp6_hdr), 5218 &pd->hdr.icmp6, M_NOWAIT); 5219 if (pf_change_icmp_af(pd->m, ipoff2, 5220 pd, &pd2, &nk->addr[sidx], 5221 &nk->addr[didx], pd->af, nk->af)) 5222 return (PF_DROP); 5223 if (nk->af == AF_INET) 5224 pd->proto = IPPROTO_ICMP; 5225 else 5226 pd->proto = IPPROTO_ICMPV6; 5227 pd->m->m_pkthdr.ph_rtableid = 5228 nk->rdomain; 5229 pd->destchg = 1; 5230 PF_ACPY(&pd->nsaddr, 5231 &nk->addr[pd2.sidx], nk->af); 5232 PF_ACPY(&pd->ndaddr, 5233 &nk->addr[pd2.didx], nk->af); 5234 pd->naf = nk->af; 5235 5236 pf_patch_16(pd, 5237 &uh->uh_sport, nk->port[sidx]); 5238 pf_patch_16(pd, 5239 &uh->uh_dport, nk->port[didx]); 5240 5241 m_copyback(pd2.m, pd2.off, sizeof(*uh), 5242 uh, M_NOWAIT); 5243 return (PF_AFRT); 5244 } 5245 #endif /* INET6 */ 5246 5247 if (PF_ANEQ(pd2.src, 5248 &nk->addr[pd2.sidx], pd2.af) || 5249 nk->port[pd2.sidx] != uh->uh_sport) 5250 pf_translate_icmp(pd, pd2.src, 5251 &uh->uh_sport, pd->dst, 5252 &nk->addr[pd2.sidx], 5253 nk->port[pd2.sidx]); 5254 5255 if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], 5256 pd2.af) || pd2.rdomain != nk->rdomain) 5257 pd->destchg = 1; 5258 pd->m->m_pkthdr.ph_rtableid = nk->rdomain; 5259 5260 if (PF_ANEQ(pd2.dst, 5261 &nk->addr[pd2.didx], pd2.af) || 5262 nk->port[pd2.didx] != uh->uh_dport) 5263 pf_translate_icmp(pd, pd2.dst, 5264 &uh->uh_dport, pd->src, 5265 &nk->addr[pd2.didx], 5266 nk->port[pd2.didx]); 5267 5268 switch (pd2.af) { 5269 case AF_INET: 5270 m_copyback(pd->m, pd->off, ICMP_MINLEN, 5271 &pd->hdr.icmp, M_NOWAIT); 5272 m_copyback(pd2.m, ipoff2, sizeof(h2), 5273 &h2, M_NOWAIT); 5274 break; 5275 #ifdef INET6 5276 case AF_INET6: 5277 m_copyback(pd->m, pd->off, 5278 sizeof(struct icmp6_hdr), 5279 &pd->hdr.icmp6, M_NOWAIT); 5280 m_copyback(pd2.m, ipoff2, sizeof(h2_6), 5281 &h2_6, M_NOWAIT); 5282 break; 5283 #endif /* INET6 */ 5284 } 5285 /* Avoid recomputing quoted UDP checksum. 5286 * note: udp6 0 csum invalid per rfc2460 p27. 5287 * but presumed nothing cares in this context */ 5288 pf_patch_16(pd, &uh->uh_sum, 0); 5289 m_copyback(pd2.m, pd2.off, sizeof(*uh), uh, 5290 M_NOWAIT); 5291 copyback = 1; 5292 } 5293 break; 5294 } 5295 case IPPROTO_ICMP: { 5296 struct icmp *iih = &pd2.hdr.icmp; 5297 5298 if (pd2.af != AF_INET) { 5299 REASON_SET(reason, PFRES_NORM); 5300 return (PF_DROP); 5301 } 5302 5303 if (!pf_pull_hdr(pd2.m, pd2.off, iih, ICMP_MINLEN, 5304 NULL, reason, pd2.af)) { 5305 DPFPRINTF(LOG_NOTICE, 5306 "ICMP error message too short (icmp)"); 5307 return (PF_DROP); 5308 } 5309 5310 pf_icmp_mapping(&pd2, iih->icmp_type, 5311 &icmp_dir, &virtual_id, &virtual_type); 5312 5313 ret = pf_icmp_state_lookup(&pd2, &key, state, 5314 virtual_id, virtual_type, icmp_dir, &iidx, 0, 1); 5315 if (ret >= 0) 5316 return (ret); 5317 5318 /* translate source/destination address, if necessary */ 5319 if ((*state)->key[PF_SK_WIRE] != 5320 (*state)->key[PF_SK_STACK]) { 5321 struct pf_state_key *nk; 5322 int afto, sidx, didx; 5323 5324 if (PF_REVERSED_KEY((*state)->key, pd->af)) 5325 nk = (*state)->key[pd->sidx]; 5326 else 5327 nk = (*state)->key[pd->didx]; 5328 5329 afto = pd->af != nk->af; 5330 sidx = afto ? pd2.didx : pd2.sidx; 5331 didx = afto ? pd2.sidx : pd2.didx; 5332 iidx = afto ? !iidx : iidx; 5333 5334 #ifdef INET6 5335 if (afto) { 5336 if (nk->af != AF_INET6) 5337 return (PF_DROP); 5338 if (pf_translate_icmp_af(pd, nk->af, 5339 &pd->hdr.icmp)) 5340 return (PF_DROP); 5341 m_copyback(pd->m, pd->off, 5342 sizeof(struct icmp6_hdr), 5343 &pd->hdr.icmp6, M_NOWAIT); 5344 if (pf_change_icmp_af(pd->m, ipoff2, 5345 pd, &pd2, &nk->addr[sidx], 5346 &nk->addr[didx], pd->af, nk->af)) 5347 return (PF_DROP); 5348 pd->proto = IPPROTO_ICMPV6; 5349 if (pf_translate_icmp_af(pd, 5350 nk->af, iih)) 5351 return (PF_DROP); 5352 if (virtual_type == htons(ICMP_ECHO)) 5353 pf_patch_16(pd, &iih->icmp_id, 5354 nk->port[iidx]); 5355 m_copyback(pd2.m, pd2.off, ICMP_MINLEN, 5356 iih, M_NOWAIT); 5357 pd->m->m_pkthdr.ph_rtableid = 5358 nk->rdomain; 5359 pd->destchg = 1; 5360 PF_ACPY(&pd->nsaddr, 5361 &nk->addr[pd2.sidx], nk->af); 5362 PF_ACPY(&pd->ndaddr, 5363 &nk->addr[pd2.didx], nk->af); 5364 pd->naf = nk->af; 5365 return (PF_AFRT); 5366 } 5367 #endif /* INET6 */ 5368 5369 if (PF_ANEQ(pd2.src, 5370 &nk->addr[pd2.sidx], pd2.af) || 5371 (virtual_type == htons(ICMP_ECHO) && 5372 nk->port[iidx] != iih->icmp_id)) 5373 pf_translate_icmp(pd, pd2.src, 5374 (virtual_type == htons(ICMP_ECHO)) ? 5375 &iih->icmp_id : NULL, 5376 pd->dst, &nk->addr[pd2.sidx], 5377 (virtual_type == htons(ICMP_ECHO)) ? 5378 nk->port[iidx] : 0); 5379 5380 if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], 5381 pd2.af) || pd2.rdomain != nk->rdomain) 5382 pd->destchg = 1; 5383 pd->m->m_pkthdr.ph_rtableid = nk->rdomain; 5384 5385 if (PF_ANEQ(pd2.dst, 5386 &nk->addr[pd2.didx], pd2.af)) 5387 pf_translate_icmp(pd, pd2.dst, NULL, 5388 pd->src, &nk->addr[pd2.didx], 0); 5389 5390 m_copyback(pd->m, pd->off, ICMP_MINLEN, 5391 &pd->hdr.icmp, M_NOWAIT); 5392 m_copyback(pd2.m, ipoff2, sizeof(h2), &h2, 5393 M_NOWAIT); 5394 m_copyback(pd2.m, pd2.off, ICMP_MINLEN, iih, 5395 M_NOWAIT); 5396 copyback = 1; 5397 } 5398 break; 5399 } 5400 #ifdef INET6 5401 case IPPROTO_ICMPV6: { 5402 struct icmp6_hdr *iih = &pd2.hdr.icmp6; 5403 5404 if (pd2.af != AF_INET6) { 5405 REASON_SET(reason, PFRES_NORM); 5406 return (PF_DROP); 5407 } 5408 5409 if (!pf_pull_hdr(pd2.m, pd2.off, iih, 5410 sizeof(struct icmp6_hdr), NULL, reason, pd2.af)) { 5411 DPFPRINTF(LOG_NOTICE, 5412 "ICMP error message too short (icmp6)"); 5413 return (PF_DROP); 5414 } 5415 5416 pf_icmp_mapping(&pd2, iih->icmp6_type, 5417 &icmp_dir, &virtual_id, &virtual_type); 5418 ret = pf_icmp_state_lookup(&pd2, &key, state, 5419 virtual_id, virtual_type, icmp_dir, &iidx, 0, 1); 5420 /* IPv6? try matching a multicast address */ 5421 if (ret == PF_DROP && pd2.af == AF_INET6 && 5422 icmp_dir == PF_OUT) 5423 ret = pf_icmp_state_lookup(&pd2, &key, state, 5424 virtual_id, virtual_type, icmp_dir, &iidx, 5425 1, 1); 5426 if (ret >= 0) 5427 return (ret); 5428 5429 /* translate source/destination address, if necessary */ 5430 if ((*state)->key[PF_SK_WIRE] != 5431 (*state)->key[PF_SK_STACK]) { 5432 struct pf_state_key *nk; 5433 int afto, sidx, didx; 5434 5435 if (PF_REVERSED_KEY((*state)->key, pd->af)) 5436 nk = (*state)->key[pd->sidx]; 5437 else 5438 nk = (*state)->key[pd->didx]; 5439 5440 afto = pd->af != nk->af; 5441 sidx = afto ? pd2.didx : pd2.sidx; 5442 didx = afto ? pd2.sidx : pd2.didx; 5443 iidx = afto ? !iidx : iidx; 5444 5445 if (afto) { 5446 if (nk->af != AF_INET) 5447 return (PF_DROP); 5448 if (pf_translate_icmp_af(pd, nk->af, 5449 &pd->hdr.icmp)) 5450 return (PF_DROP); 5451 m_copyback(pd->m, pd->off, 5452 sizeof(struct icmp6_hdr), 5453 &pd->hdr.icmp6, M_NOWAIT); 5454 if (pf_change_icmp_af(pd->m, ipoff2, 5455 pd, &pd2, &nk->addr[sidx], 5456 &nk->addr[didx], pd->af, nk->af)) 5457 return (PF_DROP); 5458 pd->proto = IPPROTO_ICMP; 5459 if (pf_translate_icmp_af(pd, 5460 nk->af, iih)) 5461 return (PF_DROP); 5462 if (virtual_type == 5463 htons(ICMP6_ECHO_REQUEST)) 5464 pf_patch_16(pd, &iih->icmp6_id, 5465 nk->port[iidx]); 5466 m_copyback(pd2.m, pd2.off, 5467 sizeof(struct icmp6_hdr), iih, 5468 M_NOWAIT); 5469 pd->m->m_pkthdr.ph_rtableid = 5470 nk->rdomain; 5471 pd->destchg = 1; 5472 PF_ACPY(&pd->nsaddr, 5473 &nk->addr[pd2.sidx], nk->af); 5474 PF_ACPY(&pd->ndaddr, 5475 &nk->addr[pd2.didx], nk->af); 5476 pd->naf = nk->af; 5477 return (PF_AFRT); 5478 } 5479 5480 if (PF_ANEQ(pd2.src, 5481 &nk->addr[pd2.sidx], pd2.af) || 5482 ((virtual_type == 5483 htons(ICMP6_ECHO_REQUEST)) && 5484 nk->port[pd2.sidx] != iih->icmp6_id)) 5485 pf_translate_icmp(pd, pd2.src, 5486 (virtual_type == 5487 htons(ICMP6_ECHO_REQUEST)) 5488 ? &iih->icmp6_id : NULL, 5489 pd->dst, &nk->addr[pd2.sidx], 5490 (virtual_type == 5491 htons(ICMP6_ECHO_REQUEST)) 5492 ? nk->port[iidx] : 0); 5493 5494 if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], 5495 pd2.af) || pd2.rdomain != nk->rdomain) 5496 pd->destchg = 1; 5497 pd->m->m_pkthdr.ph_rtableid = nk->rdomain; 5498 5499 if (PF_ANEQ(pd2.dst, 5500 &nk->addr[pd2.didx], pd2.af)) 5501 pf_translate_icmp(pd, pd2.dst, NULL, 5502 pd->src, &nk->addr[pd2.didx], 0); 5503 5504 m_copyback(pd->m, pd->off, 5505 sizeof(struct icmp6_hdr), &pd->hdr.icmp6, 5506 M_NOWAIT); 5507 m_copyback(pd2.m, ipoff2, sizeof(h2_6), &h2_6, 5508 M_NOWAIT); 5509 m_copyback(pd2.m, pd2.off, 5510 sizeof(struct icmp6_hdr), iih, M_NOWAIT); 5511 copyback = 1; 5512 } 5513 break; 5514 } 5515 #endif /* INET6 */ 5516 default: { 5517 key.af = pd2.af; 5518 key.proto = pd2.proto; 5519 key.rdomain = pd2.rdomain; 5520 PF_ACPY(&key.addr[pd2.sidx], pd2.src, key.af); 5521 PF_ACPY(&key.addr[pd2.didx], pd2.dst, key.af); 5522 key.port[0] = key.port[1] = 0; 5523 5524 STATE_LOOKUP(pd2.kif, &key, pd2.dir, *state, pd2.m); 5525 5526 /* translate source/destination address, if necessary */ 5527 if ((*state)->key[PF_SK_WIRE] != 5528 (*state)->key[PF_SK_STACK]) { 5529 struct pf_state_key *nk = 5530 (*state)->key[pd->didx]; 5531 5532 if (PF_ANEQ(pd2.src, 5533 &nk->addr[pd2.sidx], pd2.af)) 5534 pf_translate_icmp(pd, pd2.src, NULL, 5535 pd->dst, &nk->addr[pd2.sidx], 0); 5536 5537 if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], 5538 pd2.af) || pd2.rdomain != nk->rdomain) 5539 pd->destchg = 1; 5540 pd->m->m_pkthdr.ph_rtableid = nk->rdomain; 5541 5542 if (PF_ANEQ(pd2.dst, 5543 &nk->addr[pd2.didx], pd2.af)) 5544 pf_translate_icmp(pd, pd2.dst, NULL, 5545 pd->src, &nk->addr[pd2.didx], 0); 5546 5547 switch (pd2.af) { 5548 case AF_INET: 5549 m_copyback(pd->m, pd->off, ICMP_MINLEN, 5550 &pd->hdr.icmp, M_NOWAIT); 5551 m_copyback(pd2.m, ipoff2, sizeof(h2), 5552 &h2, M_NOWAIT); 5553 break; 5554 #ifdef INET6 5555 case AF_INET6: 5556 m_copyback(pd->m, pd->off, 5557 sizeof(struct icmp6_hdr), 5558 &pd->hdr.icmp6, M_NOWAIT); 5559 m_copyback(pd2.m, ipoff2, sizeof(h2_6), 5560 &h2_6, M_NOWAIT); 5561 break; 5562 #endif /* INET6 */ 5563 } 5564 copyback = 1; 5565 } 5566 break; 5567 } 5568 } 5569 } 5570 if (copyback) { 5571 m_copyback(pd->m, pd->off, pd->hdrlen, &pd->hdr, M_NOWAIT); 5572 } 5573 5574 return (PF_PASS); 5575 } 5576 5577 /* 5578 * ipoff and off are measured from the start of the mbuf chain. 5579 * h must be at "ipoff" on the mbuf chain. 5580 */ 5581 void * 5582 pf_pull_hdr(struct mbuf *m, int off, void *p, int len, 5583 u_short *actionp, u_short *reasonp, sa_family_t af) 5584 { 5585 switch (af) { 5586 case AF_INET: { 5587 struct ip *h = mtod(m, struct ip *); 5588 u_int16_t fragoff = (ntohs(h->ip_off) & IP_OFFMASK) << 3; 5589 5590 if (fragoff) { 5591 if (fragoff >= len) 5592 ACTION_SET(actionp, PF_PASS); 5593 else { 5594 ACTION_SET(actionp, PF_DROP); 5595 REASON_SET(reasonp, PFRES_FRAG); 5596 } 5597 return (NULL); 5598 } 5599 if (m->m_pkthdr.len < off + len || 5600 ntohs(h->ip_len) < off + len) { 5601 ACTION_SET(actionp, PF_DROP); 5602 REASON_SET(reasonp, PFRES_SHORT); 5603 return (NULL); 5604 } 5605 break; 5606 } 5607 #ifdef INET6 5608 case AF_INET6: { 5609 struct ip6_hdr *h = mtod(m, struct ip6_hdr *); 5610 5611 if (m->m_pkthdr.len < off + len || 5612 (ntohs(h->ip6_plen) + sizeof(struct ip6_hdr)) < 5613 (unsigned)(off + len)) { 5614 ACTION_SET(actionp, PF_DROP); 5615 REASON_SET(reasonp, PFRES_SHORT); 5616 return (NULL); 5617 } 5618 break; 5619 } 5620 #endif /* INET6 */ 5621 } 5622 m_copydata(m, off, len, p); 5623 return (p); 5624 } 5625 5626 int 5627 pf_routable(struct pf_addr *addr, sa_family_t af, struct pfi_kif *kif, 5628 int rtableid) 5629 { 5630 struct sockaddr_storage ss; 5631 struct sockaddr_in *dst; 5632 int ret = 1; 5633 int check_mpath; 5634 #ifdef INET6 5635 struct sockaddr_in6 *dst6; 5636 #endif /* INET6 */ 5637 struct rtentry *rt = NULL; 5638 5639 check_mpath = 0; 5640 memset(&ss, 0, sizeof(ss)); 5641 switch (af) { 5642 case AF_INET: 5643 dst = (struct sockaddr_in *)&ss; 5644 dst->sin_family = AF_INET; 5645 dst->sin_len = sizeof(*dst); 5646 dst->sin_addr = addr->v4; 5647 if (ipmultipath) 5648 check_mpath = 1; 5649 break; 5650 #ifdef INET6 5651 case AF_INET6: 5652 /* 5653 * Skip check for addresses with embedded interface scope, 5654 * as they would always match anyway. 5655 */ 5656 if (IN6_IS_SCOPE_EMBED(&addr->v6)) 5657 goto out; 5658 dst6 = (struct sockaddr_in6 *)&ss; 5659 dst6->sin6_family = AF_INET6; 5660 dst6->sin6_len = sizeof(*dst6); 5661 dst6->sin6_addr = addr->v6; 5662 if (ip6_multipath) 5663 check_mpath = 1; 5664 break; 5665 #endif /* INET6 */ 5666 } 5667 5668 /* Skip checks for ipsec interfaces */ 5669 if (kif != NULL && kif->pfik_ifp->if_type == IFT_ENC) 5670 goto out; 5671 5672 rt = rtalloc((struct sockaddr *)&ss, 0, rtableid); 5673 if (rt != NULL) { 5674 /* No interface given, this is a no-route check */ 5675 if (kif == NULL) 5676 goto out; 5677 5678 if (kif->pfik_ifp == NULL) { 5679 ret = 0; 5680 goto out; 5681 } 5682 5683 /* Perform uRPF check if passed input interface */ 5684 ret = 0; 5685 do { 5686 if (rt->rt_ifidx == kif->pfik_ifp->if_index) { 5687 ret = 1; 5688 #if NCARP > 0 5689 } else { 5690 struct ifnet *ifp; 5691 5692 ifp = if_get(rt->rt_ifidx); 5693 if (ifp != NULL && ifp->if_type == IFT_CARP && 5694 ifp->if_carpdev == kif->pfik_ifp) 5695 ret = 1; 5696 if_put(ifp); 5697 #endif /* NCARP */ 5698 } 5699 5700 rt = rtable_iterate(rt); 5701 } while (check_mpath == 1 && rt != NULL && ret == 0); 5702 } else 5703 ret = 0; 5704 out: 5705 rtfree(rt); 5706 return (ret); 5707 } 5708 5709 int 5710 pf_rtlabel_match(struct pf_addr *addr, sa_family_t af, struct pf_addr_wrap *aw, 5711 int rtableid) 5712 { 5713 struct sockaddr_storage ss; 5714 struct sockaddr_in *dst; 5715 #ifdef INET6 5716 struct sockaddr_in6 *dst6; 5717 #endif /* INET6 */ 5718 struct rtentry *rt; 5719 int ret = 0; 5720 5721 memset(&ss, 0, sizeof(ss)); 5722 switch (af) { 5723 case AF_INET: 5724 dst = (struct sockaddr_in *)&ss; 5725 dst->sin_family = AF_INET; 5726 dst->sin_len = sizeof(*dst); 5727 dst->sin_addr = addr->v4; 5728 break; 5729 #ifdef INET6 5730 case AF_INET6: 5731 dst6 = (struct sockaddr_in6 *)&ss; 5732 dst6->sin6_family = AF_INET6; 5733 dst6->sin6_len = sizeof(*dst6); 5734 dst6->sin6_addr = addr->v6; 5735 break; 5736 #endif /* INET6 */ 5737 } 5738 5739 rt = rtalloc((struct sockaddr *)&ss, RT_RESOLVE, rtableid); 5740 if (rt != NULL) { 5741 if (rt->rt_labelid == aw->v.rtlabel) 5742 ret = 1; 5743 rtfree(rt); 5744 } 5745 5746 return (ret); 5747 } 5748 5749 /* pf_route() may change pd->m, adjust local copies after calling */ 5750 void 5751 pf_route(struct pf_pdesc *pd, struct pf_rule *r, struct pf_state *s) 5752 { 5753 struct mbuf *m0, *m1; 5754 struct sockaddr_in *dst, sin; 5755 struct rtentry *rt = NULL; 5756 struct ip *ip; 5757 struct ifnet *ifp = NULL; 5758 struct pf_addr naddr; 5759 struct pf_src_node *sns[PF_SN_MAX]; 5760 int error = 0; 5761 unsigned int rtableid; 5762 5763 if (pd->m->m_pkthdr.pf.routed++ > 3) { 5764 m_freem(pd->m); 5765 pd->m = NULL; 5766 return; 5767 } 5768 5769 if (r->rt == PF_DUPTO) { 5770 if ((m0 = m_dup_pkt(pd->m, max_linkhdr, M_NOWAIT)) == NULL) 5771 return; 5772 } else { 5773 if ((r->rt == PF_REPLYTO) == (r->direction == pd->dir)) 5774 return; 5775 m0 = pd->m; 5776 } 5777 5778 if (m0->m_len < sizeof(struct ip)) { 5779 DPFPRINTF(LOG_ERR, 5780 "%s: m0->m_len < sizeof(struct ip)", __func__); 5781 goto bad; 5782 } 5783 5784 ip = mtod(m0, struct ip *); 5785 5786 memset(&sin, 0, sizeof(sin)); 5787 dst = &sin; 5788 dst->sin_family = AF_INET; 5789 dst->sin_len = sizeof(*dst); 5790 dst->sin_addr = ip->ip_dst; 5791 rtableid = m0->m_pkthdr.ph_rtableid; 5792 5793 if (s == NULL) { 5794 bzero(sns, sizeof(sns)); 5795 if (pf_map_addr(AF_INET, r, 5796 (struct pf_addr *)&ip->ip_src, 5797 &naddr, NULL, sns, &r->route, PF_SN_ROUTE)) { 5798 DPFPRINTF(LOG_ERR, 5799 "%s: pf_map_addr() failed", __func__); 5800 goto bad; 5801 } 5802 5803 if (!PF_AZERO(&naddr, AF_INET)) 5804 dst->sin_addr.s_addr = naddr.v4.s_addr; 5805 ifp = r->route.kif ? 5806 r->route.kif->pfik_ifp : NULL; 5807 } else { 5808 if (!PF_AZERO(&s->rt_addr, AF_INET)) 5809 dst->sin_addr.s_addr = 5810 s->rt_addr.v4.s_addr; 5811 ifp = s->rt_kif ? s->rt_kif->pfik_ifp : NULL; 5812 } 5813 if (ifp == NULL) 5814 goto bad; 5815 5816 if (pd->kif->pfik_ifp != ifp) { 5817 if (pf_test(AF_INET, PF_OUT, ifp, &m0) != PF_PASS) 5818 goto bad; 5819 else if (m0 == NULL) 5820 goto done; 5821 if (m0->m_len < sizeof(struct ip)) { 5822 DPFPRINTF(LOG_ERR, 5823 "%s: m0->m_len < sizeof(struct ip)", __func__); 5824 goto bad; 5825 } 5826 ip = mtod(m0, struct ip *); 5827 } 5828 5829 in_proto_cksum_out(m0, ifp); 5830 5831 rt = rtalloc(sintosa(dst), RT_RESOLVE, rtableid); 5832 if (!rtisvalid(rt)) { 5833 ipstat_inc(ips_noroute); 5834 goto bad; 5835 } 5836 5837 if (ntohs(ip->ip_len) <= ifp->if_mtu) { 5838 ip->ip_sum = 0; 5839 if (ifp->if_capabilities & IFCAP_CSUM_IPv4) 5840 m0->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; 5841 else { 5842 ipstat_inc(ips_outswcsum); 5843 ip->ip_sum = in_cksum(m0, ip->ip_hl << 2); 5844 } 5845 error = ifp->if_output(ifp, m0, sintosa(dst), rt); 5846 goto done; 5847 } 5848 5849 /* 5850 * Too large for interface; fragment if possible. 5851 * Must be able to put at least 8 bytes per fragment. 5852 */ 5853 if (ip->ip_off & htons(IP_DF)) { 5854 ipstat_inc(ips_cantfrag); 5855 if (r->rt != PF_DUPTO) { 5856 icmp_error(m0, ICMP_UNREACH, ICMP_UNREACH_NEEDFRAG, 0, 5857 ifp->if_mtu); 5858 goto done; 5859 } else 5860 goto bad; 5861 } 5862 5863 m1 = m0; 5864 error = ip_fragment(m0, ifp, ifp->if_mtu); 5865 if (error) { 5866 m0 = NULL; 5867 goto bad; 5868 } 5869 5870 for (m0 = m1; m0; m0 = m1) { 5871 m1 = m0->m_nextpkt; 5872 m0->m_nextpkt = 0; 5873 if (error == 0) 5874 error = ifp->if_output(ifp, m0, sintosa(dst), rt); 5875 else 5876 m_freem(m0); 5877 } 5878 5879 if (error == 0) 5880 ipstat_inc(ips_fragmented); 5881 5882 done: 5883 if (r->rt != PF_DUPTO) 5884 pd->m = NULL; 5885 rtfree(rt); 5886 return; 5887 5888 bad: 5889 m_freem(m0); 5890 goto done; 5891 } 5892 5893 #ifdef INET6 5894 /* pf_route6() may change pd->m, adjust local copies after calling */ 5895 void 5896 pf_route6(struct pf_pdesc *pd, struct pf_rule *r, struct pf_state *s) 5897 { 5898 struct mbuf *m0; 5899 struct sockaddr_in6 *dst, sin6; 5900 struct rtentry *rt = NULL; 5901 struct ip6_hdr *ip6; 5902 struct ifnet *ifp = NULL; 5903 struct pf_addr naddr; 5904 struct pf_src_node *sns[PF_SN_MAX]; 5905 struct m_tag *mtag; 5906 unsigned int rtableid; 5907 5908 if (pd->m->m_pkthdr.pf.routed++ > 3) { 5909 m_freem(pd->m); 5910 pd->m = NULL; 5911 return; 5912 } 5913 5914 if (r->rt == PF_DUPTO) { 5915 if ((m0 = m_dup_pkt(pd->m, max_linkhdr, M_NOWAIT)) == NULL) 5916 return; 5917 } else { 5918 if ((r->rt == PF_REPLYTO) == (r->direction == pd->dir)) 5919 return; 5920 m0 = pd->m; 5921 } 5922 5923 if (m0->m_len < sizeof(struct ip6_hdr)) { 5924 DPFPRINTF(LOG_ERR, 5925 "%s: m0->m_len < sizeof(struct ip6_hdr)", __func__); 5926 goto bad; 5927 } 5928 ip6 = mtod(m0, struct ip6_hdr *); 5929 5930 memset(&sin6, 0, sizeof(sin6)); 5931 dst = &sin6; 5932 dst->sin6_family = AF_INET6; 5933 dst->sin6_len = sizeof(*dst); 5934 dst->sin6_addr = ip6->ip6_dst; 5935 rtableid = m0->m_pkthdr.ph_rtableid; 5936 5937 if (s == NULL) { 5938 bzero(sns, sizeof(sns)); 5939 if (pf_map_addr(AF_INET6, r, (struct pf_addr *)&ip6->ip6_src, 5940 &naddr, NULL, sns, &r->route, PF_SN_ROUTE)) { 5941 DPFPRINTF(LOG_ERR, 5942 "%s: pf_map_addr() failed", __func__); 5943 goto bad; 5944 } 5945 if (!PF_AZERO(&naddr, AF_INET6)) 5946 PF_ACPY((struct pf_addr *)&dst->sin6_addr, 5947 &naddr, AF_INET6); 5948 ifp = r->route.kif ? r->route.kif->pfik_ifp : NULL; 5949 } else { 5950 if (!PF_AZERO(&s->rt_addr, AF_INET6)) 5951 PF_ACPY((struct pf_addr *)&dst->sin6_addr, 5952 &s->rt_addr, AF_INET6); 5953 ifp = s->rt_kif ? s->rt_kif->pfik_ifp : NULL; 5954 } 5955 if (ifp == NULL) 5956 goto bad; 5957 5958 if (pd->kif->pfik_ifp != ifp) { 5959 if (pf_test(AF_INET6, PF_OUT, ifp, &m0) != PF_PASS) 5960 goto bad; 5961 else if (m0 == NULL) 5962 goto done; 5963 if (m0->m_len < sizeof(struct ip6_hdr)) { 5964 DPFPRINTF(LOG_ERR, 5965 "%s: m0->m_len < sizeof(struct ip6_hdr)", __func__); 5966 goto bad; 5967 } 5968 } 5969 5970 in6_proto_cksum_out(m0, ifp); 5971 5972 if (IN6_IS_SCOPE_EMBED(&dst->sin6_addr)) 5973 dst->sin6_addr.s6_addr16[1] = htons(ifp->if_index); 5974 5975 rt = rtalloc(sin6tosa(dst), RT_RESOLVE, rtableid); 5976 if (!rtisvalid(rt)) { 5977 ip6stat_inc(ip6s_noroute); 5978 goto bad; 5979 } 5980 5981 /* 5982 * If packet has been reassembled by PF earlier, we have to 5983 * use pf_refragment6() here to turn it back to fragments. 5984 */ 5985 if ((mtag = m_tag_find(m0, PACKET_TAG_PF_REASSEMBLED, NULL))) { 5986 (void) pf_refragment6(&m0, mtag, dst, ifp, rt); 5987 } else if ((u_long)m0->m_pkthdr.len <= ifp->if_mtu) { 5988 ifp->if_output(ifp, m0, sin6tosa(dst), rt); 5989 } else { 5990 icmp6_error(m0, ICMP6_PACKET_TOO_BIG, 0, ifp->if_mtu); 5991 } 5992 5993 done: 5994 if (r->rt != PF_DUPTO) 5995 pd->m = NULL; 5996 rtfree(rt); 5997 return; 5998 5999 bad: 6000 m_freem(m0); 6001 goto done; 6002 } 6003 #endif /* INET6 */ 6004 6005 6006 /* 6007 * check TCP checksum and set mbuf flag 6008 * off is the offset where the protocol header starts 6009 * len is the total length of protocol header plus payload 6010 * returns 0 when the checksum is valid, otherwise returns 1. 6011 * if the _OUT flag is set the checksum isn't done yet, consider these ok 6012 */ 6013 int 6014 pf_check_tcp_cksum(struct mbuf *m, int off, int len, sa_family_t af) 6015 { 6016 u_int16_t sum; 6017 6018 if (m->m_pkthdr.csum_flags & 6019 (M_TCP_CSUM_IN_OK | M_TCP_CSUM_OUT)) { 6020 return (0); 6021 } 6022 if (m->m_pkthdr.csum_flags & M_TCP_CSUM_IN_BAD || 6023 off < sizeof(struct ip) || 6024 m->m_pkthdr.len < off + len) { 6025 return (1); 6026 } 6027 6028 /* need to do it in software */ 6029 tcpstat_inc(tcps_inswcsum); 6030 6031 switch (af) { 6032 case AF_INET: 6033 if (m->m_len < sizeof(struct ip)) 6034 return (1); 6035 6036 sum = in4_cksum(m, IPPROTO_TCP, off, len); 6037 break; 6038 #ifdef INET6 6039 case AF_INET6: 6040 if (m->m_len < sizeof(struct ip6_hdr)) 6041 return (1); 6042 6043 sum = in6_cksum(m, IPPROTO_TCP, off, len); 6044 break; 6045 #endif /* INET6 */ 6046 default: 6047 unhandled_af(af); 6048 } 6049 if (sum) { 6050 tcpstat_inc(tcps_rcvbadsum); 6051 m->m_pkthdr.csum_flags |= M_TCP_CSUM_IN_BAD; 6052 return (1); 6053 } 6054 6055 m->m_pkthdr.csum_flags |= M_TCP_CSUM_IN_OK; 6056 return (0); 6057 } 6058 6059 struct pf_divert * 6060 pf_find_divert(struct mbuf *m) 6061 { 6062 struct m_tag *mtag; 6063 6064 if ((mtag = m_tag_find(m, PACKET_TAG_PF_DIVERT, NULL)) == NULL) 6065 return (NULL); 6066 6067 return ((struct pf_divert *)(mtag + 1)); 6068 } 6069 6070 struct pf_divert * 6071 pf_get_divert(struct mbuf *m) 6072 { 6073 struct m_tag *mtag; 6074 6075 if ((mtag = m_tag_find(m, PACKET_TAG_PF_DIVERT, NULL)) == NULL) { 6076 mtag = m_tag_get(PACKET_TAG_PF_DIVERT, sizeof(struct pf_divert), 6077 M_NOWAIT); 6078 if (mtag == NULL) 6079 return (NULL); 6080 bzero(mtag + 1, sizeof(struct pf_divert)); 6081 m_tag_prepend(m, mtag); 6082 } 6083 6084 return ((struct pf_divert *)(mtag + 1)); 6085 } 6086 6087 #ifdef INET6 6088 int 6089 pf_walk_option6(struct pf_pdesc *pd, struct ip6_hdr *h, int off, int end, 6090 u_short *reason) 6091 { 6092 struct ip6_opt opt; 6093 struct ip6_opt_jumbo jumbo; 6094 6095 while (off < end) { 6096 if (!pf_pull_hdr(pd->m, off, &opt.ip6o_type, 6097 sizeof(opt.ip6o_type), NULL, reason, AF_INET6)) { 6098 DPFPRINTF(LOG_NOTICE, "IPv6 short opt type"); 6099 return (PF_DROP); 6100 } 6101 if (opt.ip6o_type == IP6OPT_PAD1) { 6102 off++; 6103 continue; 6104 } 6105 if (!pf_pull_hdr(pd->m, off, &opt, sizeof(opt), 6106 NULL, reason, AF_INET6)) { 6107 DPFPRINTF(LOG_NOTICE, "IPv6 short opt"); 6108 return (PF_DROP); 6109 } 6110 if (off + sizeof(opt) + opt.ip6o_len > end) { 6111 DPFPRINTF(LOG_NOTICE, "IPv6 long opt"); 6112 REASON_SET(reason, PFRES_IPOPTIONS); 6113 return (PF_DROP); 6114 } 6115 switch (opt.ip6o_type) { 6116 case IP6OPT_JUMBO: 6117 if (pd->jumbolen != 0) { 6118 DPFPRINTF(LOG_NOTICE, "IPv6 multiple jumbo"); 6119 REASON_SET(reason, PFRES_IPOPTIONS); 6120 return (PF_DROP); 6121 } 6122 if (ntohs(h->ip6_plen) != 0) { 6123 DPFPRINTF(LOG_NOTICE, "IPv6 bad jumbo plen"); 6124 REASON_SET(reason, PFRES_IPOPTIONS); 6125 return (PF_DROP); 6126 } 6127 if (!pf_pull_hdr(pd->m, off, &jumbo, sizeof(jumbo), 6128 NULL, reason, AF_INET6)) { 6129 DPFPRINTF(LOG_NOTICE, "IPv6 short jumbo"); 6130 return (PF_DROP); 6131 } 6132 memcpy(&pd->jumbolen, jumbo.ip6oj_jumbo_len, 6133 sizeof(pd->jumbolen)); 6134 pd->jumbolen = ntohl(pd->jumbolen); 6135 if (pd->jumbolen < IPV6_MAXPACKET) { 6136 DPFPRINTF(LOG_NOTICE, "IPv6 short jumbolen"); 6137 REASON_SET(reason, PFRES_IPOPTIONS); 6138 return (PF_DROP); 6139 } 6140 break; 6141 default: 6142 break; 6143 } 6144 off += sizeof(opt) + opt.ip6o_len; 6145 } 6146 6147 return (PF_PASS); 6148 } 6149 6150 int 6151 pf_walk_header6(struct pf_pdesc *pd, struct ip6_hdr *h, u_short *reason) 6152 { 6153 struct ip6_frag frag; 6154 struct ip6_ext ext; 6155 struct ip6_rthdr rthdr; 6156 u_int32_t end; 6157 int hdr_cnt = 0, fraghdr_cnt = 0, rthdr_cnt = 0; 6158 6159 pd->off += sizeof(struct ip6_hdr); 6160 end = pd->off + ntohs(h->ip6_plen); 6161 pd->fragoff = pd->extoff = pd->jumbolen = 0; 6162 pd->proto = h->ip6_nxt; 6163 for (;;) { 6164 hdr_cnt++; 6165 switch (pd->proto) { 6166 case IPPROTO_FRAGMENT: 6167 if (fraghdr_cnt++) { 6168 DPFPRINTF(LOG_NOTICE, "IPv6 multiple fragment"); 6169 REASON_SET(reason, PFRES_FRAG); 6170 return (PF_DROP); 6171 } 6172 /* jumbo payload packets cannot be fragmented */ 6173 if (pd->jumbolen != 0) { 6174 DPFPRINTF(LOG_NOTICE, "IPv6 fragmented jumbo"); 6175 REASON_SET(reason, PFRES_FRAG); 6176 return (PF_DROP); 6177 } 6178 if (!pf_pull_hdr(pd->m, pd->off, &frag, sizeof(frag), 6179 NULL, reason, AF_INET6)) { 6180 DPFPRINTF(LOG_NOTICE, "IPv6 short fragment"); 6181 return (PF_DROP); 6182 } 6183 /* stop walking over non initial fragments */ 6184 if (ntohs((frag.ip6f_offlg & IP6F_OFF_MASK)) != 0) { 6185 pd->fragoff = pd->off; 6186 return (PF_PASS); 6187 } 6188 /* RFC6946: reassemble only non atomic fragments */ 6189 if (frag.ip6f_offlg & IP6F_MORE_FRAG) 6190 pd->fragoff = pd->off; 6191 pd->off += sizeof(frag); 6192 pd->proto = frag.ip6f_nxt; 6193 break; 6194 case IPPROTO_ROUTING: 6195 if (rthdr_cnt++) { 6196 DPFPRINTF(LOG_NOTICE, "IPv6 multiple rthdr"); 6197 REASON_SET(reason, PFRES_IPOPTIONS); 6198 return (PF_DROP); 6199 } 6200 /* fragments may be short */ 6201 if (pd->fragoff != 0 && end < pd->off + sizeof(rthdr)) { 6202 pd->off = pd->fragoff; 6203 pd->proto = IPPROTO_FRAGMENT; 6204 return (PF_PASS); 6205 } 6206 if (!pf_pull_hdr(pd->m, pd->off, &rthdr, sizeof(rthdr), 6207 NULL, reason, AF_INET6)) { 6208 DPFPRINTF(LOG_NOTICE, "IPv6 short rthdr"); 6209 return (PF_DROP); 6210 } 6211 if (rthdr.ip6r_type == IPV6_RTHDR_TYPE_0) { 6212 DPFPRINTF(LOG_NOTICE, "IPv6 rthdr0"); 6213 REASON_SET(reason, PFRES_IPOPTIONS); 6214 return (PF_DROP); 6215 } 6216 /* FALLTHROUGH */ 6217 case IPPROTO_HOPOPTS: 6218 /* RFC2460 4.1: Hop-by-Hop only after IPv6 header */ 6219 if (pd->proto == IPPROTO_HOPOPTS && hdr_cnt > 1) { 6220 DPFPRINTF(LOG_NOTICE, "IPv6 hopopts not first"); 6221 REASON_SET(reason, PFRES_IPOPTIONS); 6222 return (PF_DROP); 6223 } 6224 /* FALLTHROUGH */ 6225 case IPPROTO_AH: 6226 case IPPROTO_DSTOPTS: 6227 /* fragments may be short */ 6228 if (pd->fragoff != 0 && end < pd->off + sizeof(ext)) { 6229 pd->off = pd->fragoff; 6230 pd->proto = IPPROTO_FRAGMENT; 6231 return (PF_PASS); 6232 } 6233 if (!pf_pull_hdr(pd->m, pd->off, &ext, sizeof(ext), 6234 NULL, reason, AF_INET6)) { 6235 DPFPRINTF(LOG_NOTICE, "IPv6 short exthdr"); 6236 return (PF_DROP); 6237 } 6238 /* reassembly needs the ext header before the frag */ 6239 if (pd->fragoff == 0) 6240 pd->extoff = pd->off; 6241 if (pd->proto == IPPROTO_HOPOPTS && pd->fragoff == 0) { 6242 if (pf_walk_option6(pd, h, 6243 pd->off + sizeof(ext), 6244 pd->off + (ext.ip6e_len + 1) * 8, reason) 6245 != PF_PASS) 6246 return (PF_DROP); 6247 if (ntohs(h->ip6_plen) == 0 && 6248 pd->jumbolen != 0) { 6249 DPFPRINTF(LOG_NOTICE, 6250 "IPv6 missing jumbo"); 6251 REASON_SET(reason, PFRES_IPOPTIONS); 6252 return (PF_DROP); 6253 } 6254 } 6255 if (pd->proto == IPPROTO_AH) 6256 pd->off += (ext.ip6e_len + 2) * 4; 6257 else 6258 pd->off += (ext.ip6e_len + 1) * 8; 6259 pd->proto = ext.ip6e_nxt; 6260 break; 6261 case IPPROTO_TCP: 6262 case IPPROTO_UDP: 6263 case IPPROTO_ICMPV6: 6264 /* fragments may be short, ignore inner header then */ 6265 if (pd->fragoff != 0 && end < pd->off + 6266 (pd->proto == IPPROTO_TCP ? sizeof(struct tcphdr) : 6267 pd->proto == IPPROTO_UDP ? sizeof(struct udphdr) : 6268 sizeof(struct icmp6_hdr))) { 6269 pd->off = pd->fragoff; 6270 pd->proto = IPPROTO_FRAGMENT; 6271 } 6272 /* FALLTHROUGH */ 6273 default: 6274 return (PF_PASS); 6275 } 6276 } 6277 } 6278 #endif /* INET6 */ 6279 6280 int 6281 pf_setup_pdesc(struct pf_pdesc *pd, sa_family_t af, int dir, 6282 struct pfi_kif *kif, struct mbuf *m, u_short *reason) 6283 { 6284 bzero(pd, sizeof(*pd)); 6285 pd->dir = dir; 6286 pd->kif = kif; /* kif is NULL when called by pflog */ 6287 pd->m = m; 6288 pd->sidx = (dir == PF_IN) ? 0 : 1; 6289 pd->didx = (dir == PF_IN) ? 1 : 0; 6290 pd->af = pd->naf = af; 6291 pd->rdomain = rtable_l2(pd->m->m_pkthdr.ph_rtableid); 6292 6293 switch (pd->af) { 6294 case AF_INET: { 6295 struct ip *h; 6296 6297 /* Check for illegal packets */ 6298 if (pd->m->m_pkthdr.len < (int)sizeof(struct ip)) { 6299 REASON_SET(reason, PFRES_SHORT); 6300 return (PF_DROP); 6301 } 6302 6303 h = mtod(pd->m, struct ip *); 6304 pd->off = h->ip_hl << 2; 6305 6306 if (pd->off < sizeof(struct ip) || 6307 pd->off > ntohs(h->ip_len) || 6308 pd->m->m_pkthdr.len < ntohs(h->ip_len)) { 6309 REASON_SET(reason, PFRES_SHORT); 6310 return (PF_DROP); 6311 } 6312 6313 pd->src = (struct pf_addr *)&h->ip_src; 6314 pd->dst = (struct pf_addr *)&h->ip_dst; 6315 pd->virtual_proto = pd->proto = h->ip_p; 6316 pd->tot_len = ntohs(h->ip_len); 6317 pd->tos = h->ip_tos & ~IPTOS_ECN_MASK; 6318 pd->ttl = h->ip_ttl; 6319 if (h->ip_hl > 5) /* has options */ 6320 pd->badopts++; 6321 6322 if (h->ip_off & htons(IP_MF | IP_OFFMASK)) 6323 pd->virtual_proto = PF_VPROTO_FRAGMENT; 6324 6325 break; 6326 } 6327 #ifdef INET6 6328 case AF_INET6: { 6329 struct ip6_hdr *h; 6330 6331 /* Check for illegal packets */ 6332 if (pd->m->m_pkthdr.len < (int)sizeof(struct ip6_hdr)) { 6333 REASON_SET(reason, PFRES_SHORT); 6334 return (PF_DROP); 6335 } 6336 6337 h = mtod(pd->m, struct ip6_hdr *); 6338 pd->off = 0; 6339 6340 if (pd->m->m_pkthdr.len < 6341 sizeof(struct ip6_hdr) + ntohs(h->ip6_plen)) { 6342 REASON_SET(reason, PFRES_SHORT); 6343 return (PF_DROP); 6344 } 6345 6346 if (pf_walk_header6(pd, h, reason) != PF_PASS) 6347 return (PF_DROP); 6348 6349 #if 1 6350 /* 6351 * we do not support jumbogram yet. if we keep going, zero 6352 * ip6_plen will do something bad, so drop the packet for now. 6353 */ 6354 if (pd->jumbolen != 0) { 6355 REASON_SET(reason, PFRES_NORM); 6356 return (PF_DROP); 6357 } 6358 #endif /* 1 */ 6359 6360 pd->src = (struct pf_addr *)&h->ip6_src; 6361 pd->dst = (struct pf_addr *)&h->ip6_dst; 6362 pd->virtual_proto = pd->proto; 6363 pd->tot_len = ntohs(h->ip6_plen) + sizeof(struct ip6_hdr); 6364 pd->tos = (ntohl(h->ip6_flow) & 0x0fc00000) >> 20; 6365 pd->ttl = h->ip6_hlim; 6366 6367 if (pd->fragoff != 0) 6368 pd->virtual_proto = PF_VPROTO_FRAGMENT; 6369 6370 break; 6371 } 6372 #endif /* INET6 */ 6373 default: 6374 panic("pf_setup_pdesc called with illegal af %u", pd->af); 6375 6376 } 6377 6378 PF_ACPY(&pd->nsaddr, pd->src, pd->af); 6379 PF_ACPY(&pd->ndaddr, pd->dst, pd->af); 6380 6381 switch (pd->virtual_proto) { 6382 case IPPROTO_TCP: { 6383 struct tcphdr *th = &pd->hdr.tcp; 6384 6385 if (!pf_pull_hdr(pd->m, pd->off, th, sizeof(*th), 6386 NULL, reason, pd->af)) 6387 return (PF_DROP); 6388 pd->hdrlen = sizeof(*th); 6389 if (pd->off + (th->th_off << 2) > pd->tot_len || 6390 (th->th_off << 2) < sizeof(struct tcphdr)) { 6391 REASON_SET(reason, PFRES_SHORT); 6392 return (PF_DROP); 6393 } 6394 pd->p_len = pd->tot_len - pd->off - (th->th_off << 2); 6395 pd->sport = &th->th_sport; 6396 pd->dport = &th->th_dport; 6397 pd->pcksum = &th->th_sum; 6398 break; 6399 } 6400 case IPPROTO_UDP: { 6401 struct udphdr *uh = &pd->hdr.udp; 6402 6403 if (!pf_pull_hdr(pd->m, pd->off, uh, sizeof(*uh), 6404 NULL, reason, pd->af)) 6405 return (PF_DROP); 6406 pd->hdrlen = sizeof(*uh); 6407 if (uh->uh_dport == 0 || 6408 pd->off + ntohs(uh->uh_ulen) > pd->tot_len || 6409 ntohs(uh->uh_ulen) < sizeof(struct udphdr)) { 6410 REASON_SET(reason, PFRES_SHORT); 6411 return (PF_DROP); 6412 } 6413 pd->sport = &uh->uh_sport; 6414 pd->dport = &uh->uh_dport; 6415 pd->pcksum = &uh->uh_sum; 6416 break; 6417 } 6418 case IPPROTO_ICMP: { 6419 if (!pf_pull_hdr(pd->m, pd->off, &pd->hdr.icmp, ICMP_MINLEN, 6420 NULL, reason, pd->af)) 6421 return (PF_DROP); 6422 pd->hdrlen = ICMP_MINLEN; 6423 if (pd->off + pd->hdrlen > pd->tot_len) { 6424 REASON_SET(reason, PFRES_SHORT); 6425 return (PF_DROP); 6426 } 6427 pd->pcksum = &pd->hdr.icmp.icmp_cksum; 6428 break; 6429 } 6430 #ifdef INET6 6431 case IPPROTO_ICMPV6: { 6432 size_t icmp_hlen = sizeof(struct icmp6_hdr); 6433 6434 if (!pf_pull_hdr(pd->m, pd->off, &pd->hdr.icmp6, icmp_hlen, 6435 NULL, reason, pd->af)) 6436 return (PF_DROP); 6437 /* ICMP headers we look further into to match state */ 6438 switch (pd->hdr.icmp6.icmp6_type) { 6439 case MLD_LISTENER_QUERY: 6440 case MLD_LISTENER_REPORT: 6441 icmp_hlen = sizeof(struct mld_hdr); 6442 break; 6443 case ND_NEIGHBOR_SOLICIT: 6444 case ND_NEIGHBOR_ADVERT: 6445 icmp_hlen = sizeof(struct nd_neighbor_solicit); 6446 break; 6447 } 6448 if (icmp_hlen > sizeof(struct icmp6_hdr) && 6449 !pf_pull_hdr(pd->m, pd->off, &pd->hdr.icmp6, icmp_hlen, 6450 NULL, reason, pd->af)) 6451 return (PF_DROP); 6452 pd->hdrlen = icmp_hlen; 6453 if (pd->off + pd->hdrlen > pd->tot_len) { 6454 REASON_SET(reason, PFRES_SHORT); 6455 return (PF_DROP); 6456 } 6457 pd->pcksum = &pd->hdr.icmp6.icmp6_cksum; 6458 break; 6459 } 6460 #endif /* INET6 */ 6461 } 6462 6463 if (pd->sport) 6464 pd->osport = pd->nsport = *pd->sport; 6465 if (pd->dport) 6466 pd->odport = pd->ndport = *pd->dport; 6467 6468 return (PF_PASS); 6469 } 6470 6471 void 6472 pf_counters_inc(int action, struct pf_pdesc *pd, struct pf_state *s, 6473 struct pf_rule *r, struct pf_rule *a) 6474 { 6475 int dirndx; 6476 pd->kif->pfik_bytes[pd->af == AF_INET6][pd->dir == PF_OUT] 6477 [action != PF_PASS] += pd->tot_len; 6478 pd->kif->pfik_packets[pd->af == AF_INET6][pd->dir == PF_OUT] 6479 [action != PF_PASS]++; 6480 6481 if (action == PF_PASS || action == PF_AFRT || r->action == PF_DROP) { 6482 dirndx = (pd->dir == PF_OUT); 6483 r->packets[dirndx]++; 6484 r->bytes[dirndx] += pd->tot_len; 6485 if (a != NULL) { 6486 a->packets[dirndx]++; 6487 a->bytes[dirndx] += pd->tot_len; 6488 } 6489 if (s != NULL) { 6490 struct pf_rule_item *ri; 6491 struct pf_sn_item *sni; 6492 6493 SLIST_FOREACH(sni, &s->src_nodes, next) { 6494 sni->sn->packets[dirndx]++; 6495 sni->sn->bytes[dirndx] += pd->tot_len; 6496 } 6497 dirndx = (pd->dir == s->direction) ? 0 : 1; 6498 s->packets[dirndx]++; 6499 s->bytes[dirndx] += pd->tot_len; 6500 6501 SLIST_FOREACH(ri, &s->match_rules, entry) { 6502 ri->r->packets[dirndx]++; 6503 ri->r->bytes[dirndx] += pd->tot_len; 6504 6505 if (ri->r->src.addr.type == PF_ADDR_TABLE) 6506 pfr_update_stats(ri->r->src.addr.p.tbl, 6507 &s->key[(s->direction == PF_IN)]-> 6508 addr[(s->direction == PF_OUT)], 6509 pd, ri->r->action, ri->r->src.neg); 6510 if (ri->r->dst.addr.type == PF_ADDR_TABLE) 6511 pfr_update_stats(ri->r->dst.addr.p.tbl, 6512 &s->key[(s->direction == PF_IN)]-> 6513 addr[(s->direction == PF_IN)], 6514 pd, ri->r->action, ri->r->dst.neg); 6515 } 6516 } 6517 if (r->src.addr.type == PF_ADDR_TABLE) 6518 pfr_update_stats(r->src.addr.p.tbl, 6519 (s == NULL) ? pd->src : 6520 &s->key[(s->direction == PF_IN)]-> 6521 addr[(s->direction == PF_OUT)], 6522 pd, r->action, r->src.neg); 6523 if (r->dst.addr.type == PF_ADDR_TABLE) 6524 pfr_update_stats(r->dst.addr.p.tbl, 6525 (s == NULL) ? pd->dst : 6526 &s->key[(s->direction == PF_IN)]-> 6527 addr[(s->direction == PF_IN)], 6528 pd, r->action, r->dst.neg); 6529 } 6530 } 6531 6532 int 6533 pf_test(sa_family_t af, int fwdir, struct ifnet *ifp, struct mbuf **m0) 6534 { 6535 struct pfi_kif *kif; 6536 u_short action, reason = 0; 6537 struct pf_rule *a = NULL, *r = &pf_default_rule; 6538 struct pf_state *s = NULL; 6539 struct pf_ruleset *ruleset = NULL; 6540 struct pf_pdesc pd; 6541 int dir = (fwdir == PF_FWD) ? PF_OUT : fwdir; 6542 u_int32_t qid, pqid = 0; 6543 6544 if (!pf_status.running) 6545 return (PF_PASS); 6546 6547 #if NCARP > 0 6548 if (ifp->if_type == IFT_CARP && ifp->if_carpdev) 6549 kif = (struct pfi_kif *)ifp->if_carpdev->if_pf_kif; 6550 else 6551 #endif /* NCARP */ 6552 kif = (struct pfi_kif *)ifp->if_pf_kif; 6553 6554 if (kif == NULL) { 6555 DPFPRINTF(LOG_ERR, 6556 "%s: kif == NULL, if_xname %s", __func__, ifp->if_xname); 6557 return (PF_DROP); 6558 } 6559 if (kif->pfik_flags & PFI_IFLAG_SKIP) 6560 return (PF_PASS); 6561 6562 #ifdef DIAGNOSTIC 6563 if (((*m0)->m_flags & M_PKTHDR) == 0) 6564 panic("non-M_PKTHDR is passed to pf_test"); 6565 #endif /* DIAGNOSTIC */ 6566 6567 if ((*m0)->m_pkthdr.pf.flags & PF_TAG_GENERATED) 6568 return (PF_PASS); 6569 6570 if ((*m0)->m_pkthdr.pf.flags & PF_TAG_DIVERTED_PACKET) 6571 return (PF_PASS); 6572 6573 if ((*m0)->m_pkthdr.pf.flags & PF_TAG_REFRAGMENTED) { 6574 (*m0)->m_pkthdr.pf.flags &= ~PF_TAG_REFRAGMENTED; 6575 return (PF_PASS); 6576 } 6577 6578 action = pf_setup_pdesc(&pd, af, dir, kif, *m0, &reason); 6579 if (action != PF_PASS) { 6580 #if NPFLOG > 0 6581 pd.pflog |= PF_LOG_FORCE; 6582 #endif /* NPFLOG > 0 */ 6583 goto done; 6584 } 6585 6586 /* packet normalization and reassembly */ 6587 switch (pd.af) { 6588 case AF_INET: 6589 action = pf_normalize_ip(&pd, &reason); 6590 break; 6591 #ifdef INET6 6592 case AF_INET6: 6593 action = pf_normalize_ip6(&pd, &reason); 6594 break; 6595 #endif /* INET6 */ 6596 } 6597 *m0 = pd.m; 6598 /* if packet sits in reassembly queue, return without error */ 6599 if (pd.m == NULL) 6600 return PF_PASS; 6601 if (action != PF_PASS) { 6602 #if NPFLOG > 0 6603 pd.pflog |= PF_LOG_FORCE; 6604 #endif /* NPFLOG > 0 */ 6605 goto done; 6606 } 6607 6608 /* if packet has been reassembled, update packet description */ 6609 if (pf_status.reass && pd.virtual_proto == PF_VPROTO_FRAGMENT) { 6610 action = pf_setup_pdesc(&pd, af, dir, kif, pd.m, &reason); 6611 if (action != PF_PASS) { 6612 #if NPFLOG > 0 6613 pd.pflog |= PF_LOG_FORCE; 6614 #endif /* NPFLOG > 0 */ 6615 goto done; 6616 } 6617 } 6618 pd.m->m_pkthdr.pf.flags |= PF_TAG_PROCESSED; 6619 6620 switch (pd.virtual_proto) { 6621 6622 case PF_VPROTO_FRAGMENT: { 6623 /* 6624 * handle fragments that aren't reassembled by 6625 * normalization 6626 */ 6627 action = pf_test_rule(&pd, &r, &s, &a, &ruleset, &reason); 6628 if (action != PF_PASS) 6629 REASON_SET(&reason, PFRES_FRAG); 6630 break; 6631 } 6632 6633 case IPPROTO_ICMP: { 6634 if (pd.af != AF_INET) { 6635 action = PF_DROP; 6636 REASON_SET(&reason, PFRES_NORM); 6637 DPFPRINTF(LOG_NOTICE, 6638 "dropping IPv6 packet with ICMPv4 payload"); 6639 goto done; 6640 } 6641 action = pf_test_state_icmp(&pd, &s, &reason); 6642 if (action == PF_PASS || action == PF_AFRT) { 6643 #if NPFSYNC > 0 6644 pfsync_update_state(s); 6645 #endif /* NPFSYNC > 0 */ 6646 r = s->rule.ptr; 6647 a = s->anchor.ptr; 6648 #if NPFLOG > 0 6649 pd.pflog |= s->log; 6650 #endif /* NPFLOG > 0 */ 6651 } else if (s == NULL) 6652 action = pf_test_rule(&pd, &r, &s, &a, &ruleset, 6653 &reason); 6654 break; 6655 } 6656 6657 #ifdef INET6 6658 case IPPROTO_ICMPV6: { 6659 if (pd.af != AF_INET6) { 6660 action = PF_DROP; 6661 REASON_SET(&reason, PFRES_NORM); 6662 DPFPRINTF(LOG_NOTICE, 6663 "dropping IPv4 packet with ICMPv6 payload"); 6664 goto done; 6665 } 6666 action = pf_test_state_icmp(&pd, &s, &reason); 6667 if (action == PF_PASS || action == PF_AFRT) { 6668 #if NPFSYNC > 0 6669 pfsync_update_state(s); 6670 #endif /* NPFSYNC > 0 */ 6671 r = s->rule.ptr; 6672 a = s->anchor.ptr; 6673 #if NPFLOG > 0 6674 pd.pflog |= s->log; 6675 #endif /* NPFLOG > 0 */ 6676 } else if (s == NULL) 6677 action = pf_test_rule(&pd, &r, &s, &a, &ruleset, 6678 &reason); 6679 break; 6680 } 6681 #endif /* INET6 */ 6682 6683 default: 6684 if (pd.virtual_proto == IPPROTO_TCP) { 6685 if ((pd.hdr.tcp.th_flags & TH_ACK) && pd.p_len == 0) 6686 pqid = 1; 6687 action = pf_normalize_tcp(&pd); 6688 if (action == PF_DROP) 6689 goto done; 6690 } 6691 action = pf_test_state(&pd, &s, &reason); 6692 if (action == PF_PASS || action == PF_AFRT) { 6693 #if NPFSYNC > 0 6694 pfsync_update_state(s); 6695 #endif /* NPFSYNC > 0 */ 6696 r = s->rule.ptr; 6697 a = s->anchor.ptr; 6698 #if NPFLOG > 0 6699 pd.pflog |= s->log; 6700 #endif /* NPFLOG > 0 */ 6701 } else if (s == NULL) 6702 action = pf_test_rule(&pd, &r, &s, &a, &ruleset, 6703 &reason); 6704 6705 if (pd.virtual_proto == IPPROTO_TCP) { 6706 if (s) { 6707 if (s->max_mss) 6708 pf_normalize_mss(&pd, s->max_mss); 6709 } else if (r->max_mss) 6710 pf_normalize_mss(&pd, r->max_mss); 6711 } 6712 6713 break; 6714 } 6715 6716 done: 6717 if (action != PF_DROP) { 6718 if (s) { 6719 /* The non-state case is handled in pf_test_rule() */ 6720 if (action == PF_PASS && pd.badopts && 6721 !(s->state_flags & PFSTATE_ALLOWOPTS)) { 6722 action = PF_DROP; 6723 REASON_SET(&reason, PFRES_IPOPTIONS); 6724 #if NPFLOG > 0 6725 pd.pflog |= PF_LOG_FORCE; 6726 #endif /* NPFLOG > 0 */ 6727 DPFPRINTF(LOG_NOTICE, "dropping packet with " 6728 "ip/ipv6 options in pf_test()"); 6729 } 6730 6731 pf_scrub(pd.m, s->state_flags, pd.af, s->min_ttl, 6732 s->set_tos); 6733 pf_tag_packet(pd.m, s->tag, s->rtableid[pd.didx]); 6734 if (pqid || (pd.tos & IPTOS_LOWDELAY)) { 6735 qid = s->pqid; 6736 if (s->state_flags & PFSTATE_SETPRIO) 6737 pd.m->m_pkthdr.pf.prio = s->set_prio[1]; 6738 } else { 6739 qid = s->qid; 6740 if (s->state_flags & PFSTATE_SETPRIO) 6741 pd.m->m_pkthdr.pf.prio = s->set_prio[0]; 6742 } 6743 } else { 6744 pf_scrub(pd.m, r->scrub_flags, pd.af, r->min_ttl, 6745 r->set_tos); 6746 if (pqid || (pd.tos & IPTOS_LOWDELAY)) { 6747 qid = r->pqid; 6748 if (r->scrub_flags & PFSTATE_SETPRIO) 6749 pd.m->m_pkthdr.pf.prio = r->set_prio[1]; 6750 } else { 6751 qid = r->qid; 6752 if (r->scrub_flags & PFSTATE_SETPRIO) 6753 pd.m->m_pkthdr.pf.prio = r->set_prio[0]; 6754 } 6755 } 6756 } 6757 6758 if (action == PF_PASS && qid) 6759 pd.m->m_pkthdr.pf.qid = qid; 6760 if (pd.dir == PF_IN && s && s->key[PF_SK_STACK]) { 6761 /* 6762 * Check below fires whenever caller forgets to call 6763 * pf_pkt_addr_changed(). This might happen when we 6764 * deal with IP tunnels. 6765 */ 6766 if (pd.m->m_pkthdr.pf.statekey != NULL) { 6767 #ifdef DDB 6768 m_print(pd.m, printf); 6769 #endif 6770 panic("incoming mbuf already has a statekey"); 6771 } 6772 pd.m->m_pkthdr.pf.statekey = 6773 pf_state_key_ref(s->key[PF_SK_STACK]); 6774 } 6775 if (pd.dir == PF_OUT && 6776 pd.m->m_pkthdr.pf.inp && !pd.m->m_pkthdr.pf.inp->inp_pf_sk && 6777 s && s->key[PF_SK_STACK] && !s->key[PF_SK_STACK]->inp) { 6778 pd.m->m_pkthdr.pf.inp->inp_pf_sk = 6779 pf_state_key_ref(s->key[PF_SK_STACK]); 6780 s->key[PF_SK_STACK]->inp = pd.m->m_pkthdr.pf.inp; 6781 } 6782 6783 if (s) { 6784 pd.m->m_pkthdr.ph_flowid = M_FLOWID_VALID | 6785 (M_FLOWID_MASK & bemtoh64(&s->id)); 6786 } 6787 6788 /* 6789 * connections redirected to loopback should not match sockets 6790 * bound specifically to loopback due to security implications, 6791 * see tcp_input() and in_pcblookup_listen(). 6792 */ 6793 if (pd.destchg) 6794 if ((pd.af == AF_INET && (ntohl(pd.dst->v4.s_addr) >> 6795 IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) || 6796 (pd.af == AF_INET6 && IN6_IS_ADDR_LOOPBACK(&pd.dst->v6))) 6797 pd.m->m_pkthdr.pf.flags |= PF_TAG_TRANSLATE_LOCALHOST; 6798 /* We need to redo the route lookup on outgoing routes. */ 6799 if (pd.destchg && pd.dir == PF_OUT) 6800 pd.m->m_pkthdr.pf.flags |= PF_TAG_REROUTE; 6801 6802 if (pd.dir == PF_IN && action == PF_PASS && r->divert.port) { 6803 struct pf_divert *divert; 6804 6805 if ((divert = pf_get_divert(pd.m))) { 6806 pd.m->m_pkthdr.pf.flags |= PF_TAG_DIVERTED; 6807 divert->port = r->divert.port; 6808 divert->rdomain = pd.rdomain; 6809 divert->addr = r->divert.addr; 6810 } 6811 } 6812 6813 if (action == PF_PASS && r->divert_packet.port) 6814 action = PF_DIVERT; 6815 6816 #if NPFLOG > 0 6817 if (pd.pflog) { 6818 struct pf_rule_item *ri; 6819 6820 if (pd.pflog & PF_LOG_FORCE || r->log & PF_LOG_ALL) 6821 PFLOG_PACKET(&pd, reason, r, a, ruleset, NULL); 6822 if (s) { 6823 SLIST_FOREACH(ri, &s->match_rules, entry) 6824 if (ri->r->log & PF_LOG_ALL) 6825 PFLOG_PACKET(&pd, reason, ri->r, a, 6826 ruleset, NULL); 6827 } 6828 } 6829 #endif /* NPFLOG > 0 */ 6830 6831 pf_counters_inc(action, &pd, s, r, a); 6832 6833 switch (action) { 6834 case PF_SYNPROXY_DROP: 6835 m_freem(pd.m); 6836 /* FALLTHROUGH */ 6837 case PF_DEFER: 6838 pd.m = NULL; 6839 action = PF_PASS; 6840 break; 6841 case PF_DIVERT: 6842 switch (pd.af) { 6843 case AF_INET: 6844 if (!divert_packet(pd.m, pd.dir, r->divert_packet.port)) 6845 pd.m = NULL; 6846 break; 6847 #ifdef INET6 6848 case AF_INET6: 6849 if (!divert6_packet(pd.m, pd.dir, 6850 r->divert_packet.port)) 6851 pd.m = NULL; 6852 break; 6853 #endif /* INET6 */ 6854 } 6855 action = PF_PASS; 6856 break; 6857 #ifdef INET6 6858 case PF_AFRT: 6859 if (pf_translate_af(&pd)) { 6860 action = PF_DROP; 6861 break; 6862 } 6863 pd.m->m_pkthdr.pf.flags |= PF_TAG_GENERATED; 6864 switch (pd.naf) { 6865 case AF_INET: 6866 if (pd.dir == PF_IN) 6867 ip_forward(pd.m, ifp, NULL, 1); 6868 else 6869 ip_output(pd.m, NULL, NULL, 0, NULL, NULL, 0); 6870 break; 6871 case AF_INET6: 6872 if (pd.dir == PF_IN) 6873 ip6_forward(pd.m, NULL, 1); 6874 else 6875 ip6_output(pd.m, NULL, NULL, 0, NULL, NULL); 6876 break; 6877 } 6878 pd.m = NULL; 6879 action = PF_PASS; 6880 break; 6881 #endif /* INET6 */ 6882 case PF_DROP: 6883 m_freem(pd.m); 6884 pd.m = NULL; 6885 break; 6886 default: 6887 if (r->rt) { 6888 switch (pd.af) { 6889 case AF_INET: 6890 pf_route(&pd, r, s); 6891 break; 6892 #ifdef INET6 6893 case AF_INET6: 6894 pf_route6(&pd, r, s); 6895 break; 6896 #endif /* INET6 */ 6897 } 6898 } 6899 break; 6900 } 6901 6902 #ifdef INET6 6903 /* if reassembled packet passed, create new fragments */ 6904 if (pf_status.reass && action == PF_PASS && pd.m && fwdir == PF_FWD) { 6905 struct m_tag *mtag; 6906 6907 if ((mtag = m_tag_find(pd.m, PACKET_TAG_PF_REASSEMBLED, NULL))) 6908 action = pf_refragment6(&pd.m, mtag, NULL, NULL, NULL); 6909 } 6910 #endif /* INET6 */ 6911 if (s && action != PF_DROP) { 6912 if (!s->if_index_in && dir == PF_IN) 6913 s->if_index_in = ifp->if_index; 6914 else if (!s->if_index_out && dir == PF_OUT) 6915 s->if_index_out = ifp->if_index; 6916 } 6917 6918 *m0 = pd.m; 6919 return (action); 6920 } 6921 6922 int 6923 pf_ouraddr(struct mbuf *m) 6924 { 6925 struct pf_state_key *sk; 6926 6927 if (m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) 6928 return (1); 6929 6930 sk = m->m_pkthdr.pf.statekey; 6931 if (sk != NULL) { 6932 if (sk->inp != NULL) 6933 return (1); 6934 6935 /* If we have linked state keys it is certainly forwarded. */ 6936 if (sk->reverse != NULL) 6937 return (0); 6938 } 6939 6940 return (-1); 6941 } 6942 6943 /* 6944 * must be called whenever any addressing information such as 6945 * address, port, protocol has changed 6946 */ 6947 void 6948 pf_pkt_addr_changed(struct mbuf *m) 6949 { 6950 pf_pkt_unlink_state_key(m); 6951 m->m_pkthdr.pf.inp = NULL; 6952 } 6953 6954 struct inpcb * 6955 pf_inp_lookup(struct mbuf *m) 6956 { 6957 struct inpcb *inp = NULL; 6958 struct pf_state_key *sk = m->m_pkthdr.pf.statekey; 6959 6960 if (!pf_state_key_isvalid(sk)) 6961 pf_pkt_unlink_state_key(m); 6962 else 6963 inp = m->m_pkthdr.pf.statekey->inp; 6964 6965 if (inp && inp->inp_pf_sk) 6966 KASSERT(m->m_pkthdr.pf.statekey == inp->inp_pf_sk); 6967 6968 return (inp); 6969 } 6970 6971 void 6972 pf_inp_link(struct mbuf *m, struct inpcb *inp) 6973 { 6974 struct pf_state_key *sk = m->m_pkthdr.pf.statekey; 6975 6976 if (!pf_state_key_isvalid(sk)) { 6977 pf_pkt_unlink_state_key(m); 6978 return; 6979 } 6980 6981 /* 6982 * we don't need to grab PF-lock here. At worst case we link inp to 6983 * state, which might be just being marked as deleted by another 6984 * thread. 6985 */ 6986 if (inp && !sk->inp && !inp->inp_pf_sk) { 6987 sk->inp = inp; 6988 inp->inp_pf_sk = pf_state_key_ref(sk); 6989 } 6990 /* The statekey has finished finding the inp, it is no longer needed. */ 6991 pf_pkt_unlink_state_key(m); 6992 } 6993 6994 void 6995 pf_inp_unlink(struct inpcb *inp) 6996 { 6997 if (inp->inp_pf_sk) { 6998 inp->inp_pf_sk->inp = NULL; 6999 pf_inpcb_unlink_state_key(inp); 7000 } 7001 } 7002 7003 void 7004 pf_state_key_link(struct pf_state_key *sk, struct pf_state_key *pkt_sk) 7005 { 7006 /* 7007 * Assert will not wire as long as we are called by pf_find_state() 7008 */ 7009 KASSERT((pkt_sk->reverse == NULL) && (sk->reverse == NULL)); 7010 pkt_sk->reverse = pf_state_key_ref(sk); 7011 sk->reverse = pf_state_key_ref(pkt_sk); 7012 } 7013 7014 #if NPFLOG > 0 7015 void 7016 pf_log_matches(struct pf_pdesc *pd, struct pf_rule *rm, struct pf_rule *am, 7017 struct pf_ruleset *ruleset, struct pf_rule_slist *matchrules) 7018 { 7019 struct pf_rule_item *ri; 7020 7021 /* if this is the log(matches) rule, packet has been logged already */ 7022 if (rm->log & PF_LOG_MATCHES) 7023 return; 7024 7025 SLIST_FOREACH(ri, matchrules, entry) 7026 if (ri->r->log & PF_LOG_MATCHES) 7027 PFLOG_PACKET(pd, PFRES_MATCH, rm, am, ruleset, ri->r); 7028 } 7029 #endif /* NPFLOG > 0 */ 7030 7031 struct pf_state_key * 7032 pf_state_key_ref(struct pf_state_key *sk) 7033 { 7034 if (sk != NULL) 7035 PF_REF_TAKE(sk->refcnt); 7036 7037 return (sk); 7038 } 7039 7040 void 7041 pf_state_key_unref(struct pf_state_key *sk) 7042 { 7043 if ((sk != NULL) && PF_REF_RELE(sk->refcnt)) { 7044 /* state key must be removed from tree */ 7045 KASSERT(!pf_state_key_isvalid(sk)); 7046 /* state key must be unlinked from reverse key */ 7047 KASSERT(sk->reverse == NULL); 7048 /* state key must be unlinked from socket */ 7049 KASSERT((sk->inp == NULL) || (sk->inp->inp_pf_sk == NULL)); 7050 sk->inp = NULL; 7051 pool_put(&pf_state_key_pl, sk); 7052 } 7053 } 7054 7055 int 7056 pf_state_key_isvalid(struct pf_state_key *sk) 7057 { 7058 return ((sk != NULL) && (sk->removed == 0)); 7059 } 7060 7061 void 7062 pf_pkt_unlink_state_key(struct mbuf *m) 7063 { 7064 pf_state_key_unref(m->m_pkthdr.pf.statekey); 7065 m->m_pkthdr.pf.statekey = NULL; 7066 } 7067 7068 void 7069 pf_pkt_state_key_ref(struct mbuf *m) 7070 { 7071 pf_state_key_ref(m->m_pkthdr.pf.statekey); 7072 } 7073 7074 void 7075 pf_inpcb_unlink_state_key(struct inpcb *inp) 7076 { 7077 if (inp != NULL) { 7078 pf_state_key_unref(inp->inp_pf_sk); 7079 inp->inp_pf_sk = NULL; 7080 } 7081 } 7082 7083 void 7084 pf_state_key_unlink_reverse(struct pf_state_key *sk) 7085 { 7086 if ((sk != NULL) && (sk->reverse != NULL)) { 7087 pf_state_key_unref(sk->reverse->reverse); 7088 sk->reverse->reverse = NULL; 7089 pf_state_key_unref(sk->reverse); 7090 sk->reverse = NULL; 7091 } 7092 } 7093