/* $OpenBSD: pf.c,v 1.334 2003/04/05 20:24:58 cedric Exp $ */ /* * Copyright (c) 2001 Daniel Hartmeier * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * - Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials provided * with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * * Effort sponsored in part by the Defense Advanced Research Projects * Agency (DARPA) and Air Force Research Laboratory, Air Force * Materiel Command, USAF, under agreement number F30602-01-2-0537. * */ #include "bpfilter.h" #include "pflog.h" #include "pfsync.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET6 #include #include #include #endif /* INET6 */ #ifdef ALTQ #include #endif #define DPFPRINTF(n, x) if (pf_status.debug >= (n)) printf x struct pf_state_tree; /* * Global variables */ struct pf_anchorqueue pf_anchors; struct pf_ruleset pf_main_ruleset; struct pf_altqqueue pf_altqs[2]; struct pf_palist pf_pabuf; struct pf_altqqueue *pf_altqs_active; struct pf_altqqueue *pf_altqs_inactive; struct pf_status pf_status; struct ifnet *status_ifp; u_int32_t ticket_altqs_active; u_int32_t ticket_altqs_inactive; u_int32_t ticket_pabuf; struct timeout pf_expire_to; /* expire timeout */ struct pool pf_tree_pl, pf_rule_pl, pf_addr_pl; struct pool pf_state_pl, pf_altq_pl, pf_pooladdr_pl; void pf_addrcpy(struct pf_addr *, struct pf_addr *, sa_family_t); int pf_insert_state(struct pf_state *); struct pf_state *pf_find_state(struct pf_state_tree *, struct pf_tree_node *); void pf_purge_expired_states(void); void pf_purge_timeout(void *); int pf_tbladdr_setup(struct pf_addr_wrap *); void pf_tbladdr_remove(struct pf_addr_wrap *); void pf_dynaddr_update(void *); void pf_print_host(struct pf_addr *, u_int16_t, u_int8_t); void pf_print_state(struct pf_state *); void pf_print_flags(u_int8_t); u_int16_t pf_cksum_fixup(u_int16_t, u_int16_t, u_int16_t, u_int8_t); void pf_change_ap(struct pf_addr *, u_int16_t *, u_int16_t *, u_int16_t *, struct pf_addr *, u_int16_t, u_int8_t, sa_family_t); void pf_change_a(u_int32_t *, u_int16_t *, u_int32_t, u_int8_t); #ifdef INET6 void pf_change_a6(struct pf_addr *, u_int16_t *, struct pf_addr *, u_int8_t); #endif /* INET6 */ void pf_change_icmp(struct pf_addr *, u_int16_t *, struct pf_addr *, struct pf_addr *, u_int16_t, u_int16_t *, u_int16_t *, u_int16_t *, u_int16_t *, u_int8_t, sa_family_t); void pf_send_reset(int, struct tcphdr *, struct pf_pdesc *, sa_family_t, u_int8_t, struct pf_rule *); void pf_send_icmp(struct mbuf *, u_int8_t, u_int8_t, sa_family_t, struct pf_rule *); struct pf_rule *pf_match_translation(int, struct ifnet *, u_int8_t, struct pf_addr *, u_int16_t, struct pf_addr *, u_int16_t, sa_family_t, int); struct pf_rule *pf_get_translation(int, struct ifnet *, u_int8_t, struct pf_addr *, u_int16_t, struct pf_addr *, u_int16_t, struct pf_addr *, u_int16_t *, sa_family_t); int pf_test_tcp(struct pf_rule **, struct pf_state **, int, struct ifnet *, struct mbuf *, int, int, void *, struct pf_pdesc *); int pf_test_udp(struct pf_rule **, struct pf_state **, int, struct ifnet *, struct mbuf *, int, int, void *, struct pf_pdesc *); int pf_test_icmp(struct pf_rule **, struct pf_state **, int, struct ifnet *, struct mbuf *, int, int, void *, struct pf_pdesc *); int pf_test_other(struct pf_rule **, struct pf_state **, int, struct ifnet *, struct mbuf *, void *, struct pf_pdesc *); int pf_test_fragment(struct pf_rule **, int, struct ifnet *, struct mbuf *, void *, struct pf_pdesc *); int pf_test_state_tcp(struct pf_state **, int, struct ifnet *, struct mbuf *, int, int, void *, struct pf_pdesc *); int pf_test_state_udp(struct pf_state **, int, struct ifnet *, struct mbuf *, int, int, void *, struct pf_pdesc *); int pf_test_state_icmp(struct pf_state **, int, struct ifnet *, struct mbuf *, int, int, void *, struct pf_pdesc *); int pf_test_state_other(struct pf_state **, int, struct ifnet *, struct pf_pdesc *); void *pf_pull_hdr(struct mbuf *, int, void *, int, u_short *, u_short *, sa_family_t); void pf_calc_skip_steps(struct pf_rulequeue *); #ifdef INET6 void pf_poolmask(struct pf_addr *, struct pf_addr*, struct pf_addr *, struct pf_addr *, u_int8_t); void pf_addr_inc(struct pf_addr *, sa_family_t); #endif /* INET6 */ void pf_hash(struct pf_addr *, struct pf_addr *, struct pf_poolhashkey *, sa_family_t); int pf_map_addr(u_int8_t, struct pf_pool *, struct pf_addr *, struct pf_addr *, struct pf_addr *); int pf_get_sport(sa_family_t, u_int8_t, struct pf_pool *, struct pf_addr *, struct pf_addr *, u_int16_t, struct pf_addr *, u_int16_t*, u_int16_t, u_int16_t); int pf_normalize_tcp(int, struct ifnet *, struct mbuf *, int, int, void *, struct pf_pdesc *); void pf_route(struct mbuf **, struct pf_rule *, int, struct ifnet *, struct pf_state *); void pf_route6(struct mbuf **, struct pf_rule *, int, struct ifnet *, struct pf_state *); int pf_socket_lookup(uid_t *, gid_t *, int, sa_family_t, int, struct pf_pdesc *); u_int8_t pf_get_wscale(struct mbuf *, int, u_int16_t, sa_family_t); int pf_check_proto_cksum(struct mbuf *, int, int, u_int8_t, sa_family_t); struct pf_pool_limit pf_pool_limits[PF_LIMIT_MAX] = { { &pf_state_pl, PFSTATE_HIWAT }, { &pf_frent_pl, PFFRAG_FRENT_HIWAT } }; #define STATE_LOOKUP() \ do { \ if (direction == PF_IN) \ *state = pf_find_state(&tree_ext_gwy, &key); \ else \ *state = pf_find_state(&tree_lan_ext, &key); \ if (*state == NULL) \ return (PF_DROP); \ if (direction == PF_OUT && \ (((*state)->rule.ptr->rt == PF_ROUTETO && \ (*state)->rule.ptr->direction == PF_OUT) || \ ((*state)->rule.ptr->rt == PF_REPLYTO && \ (*state)->rule.ptr->direction == PF_IN)) && \ (*state)->rt_ifp != NULL && \ (*state)->rt_ifp != ifp) \ return (PF_PASS); \ } while (0) #define STATE_TRANSLATE(s) \ (s)->lan.addr.addr32[0] != (s)->gwy.addr.addr32[0] || \ ((s)->af == AF_INET6 && \ ((s)->lan.addr.addr32[1] != (s)->gwy.addr.addr32[1] || \ (s)->lan.addr.addr32[2] != (s)->gwy.addr.addr32[2] || \ (s)->lan.addr.addr32[3] != (s)->gwy.addr.addr32[3])) || \ (s)->lan.port != (s)->gwy.port #define TIMEOUT(r,i) \ ((r)->timeout[(i)] ? (r)->timeout[(i)] : pf_default_rule.timeout[(i)]) static __inline int pf_state_compare(struct pf_tree_node *, struct pf_tree_node *); struct pf_state_tree tree_lan_ext, tree_ext_gwy; RB_GENERATE(pf_state_tree, pf_tree_node, entry, pf_state_compare); static __inline int pf_state_compare(struct pf_tree_node *a, struct pf_tree_node *b) { int diff; if ((diff = a->proto - b->proto) != 0) return (diff); if ((diff = a->af - b->af) != 0) return (diff); switch (a->af) { #ifdef INET case AF_INET: if (a->addr[0].addr32[0] > b->addr[0].addr32[0]) return (1); if (a->addr[0].addr32[0] < b->addr[0].addr32[0]) return (-1); if (a->addr[1].addr32[0] > b->addr[1].addr32[0]) return (1); if (a->addr[1].addr32[0] < b->addr[1].addr32[0]) return (-1); break; #endif /* INET */ #ifdef INET6 case AF_INET6: if (a->addr[0].addr32[0] > b->addr[0].addr32[0]) return (1); if (a->addr[0].addr32[0] < b->addr[0].addr32[0]) return (-1); if (a->addr[0].addr32[1] > b->addr[0].addr32[1]) return (1); if (a->addr[0].addr32[1] < b->addr[0].addr32[1]) return (-1); if (a->addr[0].addr32[2] > b->addr[0].addr32[2]) return (1); if (a->addr[0].addr32[2] < b->addr[0].addr32[2]) return (-1); if (a->addr[0].addr32[3] > b->addr[0].addr32[3]) return (1); if (a->addr[0].addr32[3] < b->addr[0].addr32[3]) return (-1); if (a->addr[1].addr32[0] > b->addr[1].addr32[0]) return (1); if (a->addr[1].addr32[0] < b->addr[1].addr32[0]) return (-1); if (a->addr[1].addr32[1] > b->addr[1].addr32[1]) return (1); if (a->addr[1].addr32[1] < b->addr[1].addr32[1]) return (-1); if (a->addr[1].addr32[2] > b->addr[1].addr32[2]) return (1); if (a->addr[1].addr32[2] < b->addr[1].addr32[2]) return (-1); if (a->addr[1].addr32[3] > b->addr[1].addr32[3]) return (1); if (a->addr[1].addr32[3] < b->addr[1].addr32[3]) return (-1); break; #endif /* INET6 */ } if ((diff = a->port[0] - b->port[0]) != 0) return (diff); if ((diff = a->port[1] - b->port[1]) != 0) return (diff); return (0); } #ifdef INET6 void pf_addrcpy(struct pf_addr *dst, struct pf_addr *src, sa_family_t af) { switch (af) { #ifdef INET case AF_INET: dst->addr32[0] = src->addr32[0]; break; #endif /* INET */ case AF_INET6: dst->addr32[0] = src->addr32[0]; dst->addr32[1] = src->addr32[1]; dst->addr32[2] = src->addr32[2]; dst->addr32[3] = src->addr32[3]; break; } } #endif struct pf_state * pf_find_state(struct pf_state_tree *tree, struct pf_tree_node *key) { struct pf_tree_node *k; pf_status.fcounters[FCNT_STATE_SEARCH]++; k = RB_FIND(pf_state_tree, tree, key); if (k) return (k->state); else return (NULL); } int pf_insert_state(struct pf_state *state) { struct pf_tree_node *keya, *keyb; keya = pool_get(&pf_tree_pl, PR_NOWAIT); if (keya == NULL) return (-1); keya->state = state; keya->proto = state->proto; keya->af = state->af; PF_ACPY(&keya->addr[0], &state->lan.addr, state->af); keya->port[0] = state->lan.port; PF_ACPY(&keya->addr[1], &state->ext.addr, state->af); keya->port[1] = state->ext.port; /* Thou MUST NOT insert multiple duplicate keys */ if (RB_INSERT(pf_state_tree, &tree_lan_ext, keya) != NULL) { if (pf_status.debug >= PF_DEBUG_MISC) { printf("pf: state insert failed: tree_lan_ext"); printf(" lan: "); pf_print_host(&state->lan.addr, state->lan.port, state->af); printf(" gwy: "); pf_print_host(&state->gwy.addr, state->gwy.port, state->af); printf(" ext: "); pf_print_host(&state->ext.addr, state->ext.port, state->af); printf("\n"); } pool_put(&pf_tree_pl, keya); return (-1); } keyb = pool_get(&pf_tree_pl, PR_NOWAIT); if (keyb == NULL) { /* Need to pull out the other state */ RB_REMOVE(pf_state_tree, &tree_lan_ext, keya); pool_put(&pf_tree_pl, keya); return (-1); } keyb->state = state; keyb->proto = state->proto; keyb->af = state->af; PF_ACPY(&keyb->addr[0], &state->ext.addr, state->af); keyb->port[0] = state->ext.port; PF_ACPY(&keyb->addr[1], &state->gwy.addr, state->af); keyb->port[1] = state->gwy.port; if (RB_INSERT(pf_state_tree, &tree_ext_gwy, keyb) != NULL) { if (pf_status.debug >= PF_DEBUG_MISC) { printf("pf: state insert failed: tree_ext_gwy"); printf(" lan: "); pf_print_host(&state->lan.addr, state->lan.port, state->af); printf(" gwy: "); pf_print_host(&state->gwy.addr, state->gwy.port, state->af); printf(" ext: "); pf_print_host(&state->ext.addr, state->ext.port, state->af); printf("\n"); } RB_REMOVE(pf_state_tree, &tree_lan_ext, keya); pool_put(&pf_tree_pl, keya); pool_put(&pf_tree_pl, keyb); return (-1); } pf_status.fcounters[FCNT_STATE_INSERT]++; pf_status.states++; #if NPFSYNC pfsync_insert_state(state); #endif return (0); } void pf_purge_timeout(void *arg) { struct timeout *to = arg; int s; s = splsoftnet(); pf_purge_expired_states(); pf_purge_expired_fragments(); splx(s); timeout_add(to, pf_default_rule.timeout[PFTM_INTERVAL] * hz); } void pf_purge_expired_states(void) { struct pf_tree_node *cur, *peer, *next; struct pf_tree_node key; for (cur = RB_MIN(pf_state_tree, &tree_ext_gwy); cur; cur = next) { next = RB_NEXT(pf_state_tree, &tree_ext_gwy, cur); if (cur->state->expire <= (unsigned)time.tv_sec) { RB_REMOVE(pf_state_tree, &tree_ext_gwy, cur); /* Need this key's peer (in the other tree) */ key.state = cur->state; key.proto = cur->state->proto; key.af = cur->state->af; PF_ACPY(&key.addr[0], &cur->state->lan.addr, cur->state->af); key.port[0] = cur->state->lan.port; PF_ACPY(&key.addr[1], &cur->state->ext.addr, cur->state->af); key.port[1] = cur->state->ext.port; peer = RB_FIND(pf_state_tree, &tree_lan_ext, &key); KASSERT(peer); KASSERT(peer->state == cur->state); RB_REMOVE(pf_state_tree, &tree_lan_ext, peer); #if NPFSYNC pfsync_delete_state(cur->state); #endif if (--cur->state->rule.ptr->states <= 0) pf_rm_rule(NULL, cur->state->rule.ptr); if (cur->state->nat_rule != NULL) if (--cur->state->nat_rule->states <= 0) pf_rm_rule(NULL, cur->state->nat_rule); pool_put(&pf_state_pl, cur->state); pool_put(&pf_tree_pl, cur); pool_put(&pf_tree_pl, peer); pf_status.fcounters[FCNT_STATE_REMOVALS]++; pf_status.states--; } } } int pf_tbladdr_setup(struct pf_addr_wrap *aw) { if (aw->type != PF_ADDR_TABLE) return (0); if ((aw->p.tbl = pfr_attach_table(aw->v.tblname)) == NULL) return (1); return (0); } void pf_tbladdr_remove(struct pf_addr_wrap *aw) { if (aw->type != PF_ADDR_TABLE || aw->p.tbl == NULL) return; pfr_detach_table(aw->p.tbl); aw->p.tbl = NULL; } void pf_tbladdr_copyout(struct pf_addr_wrap *aw) { if (aw->type != PF_ADDR_TABLE || aw->p.tbl == NULL) return; aw->p.tblcnt = (aw->p.tbl->pfrkt_flags & PFR_TFLAG_ACTIVE) ? aw->p.tbl->pfrkt_cnt : -1; } int pf_dynaddr_setup(struct pf_addr_wrap *aw, sa_family_t af) { if (aw->type != PF_ADDR_DYNIFTL) return (0); aw->p.dyn = pool_get(&pf_addr_pl, PR_NOWAIT); if (aw->p.dyn == NULL) return (1); bcopy(aw->v.ifname, aw->p.dyn->ifname, sizeof(aw->p.dyn->ifname)); aw->p.dyn->ifp = ifunit(aw->p.dyn->ifname); if (aw->p.dyn->ifp == NULL) { pool_put(&pf_addr_pl, aw->p.dyn); aw->p.dyn = NULL; return (1); } aw->p.dyn->addr = &aw->v.a.addr; aw->p.dyn->af = af; aw->p.dyn->undefined = 1; aw->p.dyn->hook_cookie = hook_establish( aw->p.dyn->ifp->if_addrhooks, 1, pf_dynaddr_update, aw->p.dyn); if (aw->p.dyn->hook_cookie == NULL) { pool_put(&pf_addr_pl, aw->p.dyn); aw->p.dyn = NULL; return (1); } pf_dynaddr_update(aw->p.dyn); return (0); } void pf_dynaddr_update(void *p) { struct pf_addr_dyn *ad = (struct pf_addr_dyn *)p; struct ifaddr *ia; int s, changed = 0; if (ad == NULL || ad->ifp == NULL) panic("pf_dynaddr_update"); s = splsoftnet(); TAILQ_FOREACH(ia, &ad->ifp->if_addrlist, ifa_list) if (ia->ifa_addr != NULL && ia->ifa_addr->sa_family == ad->af) { if (ad->af == AF_INET) { struct in_addr *a, *b; a = &ad->addr->v4; b = &((struct sockaddr_in *)ia->ifa_addr) ->sin_addr; if (ad->undefined || memcmp(a, b, sizeof(*a))) { bcopy(b, a, sizeof(*a)); changed = 1; } } else if (ad->af == AF_INET6) { struct in6_addr *a, *b; a = &ad->addr->v6; b = &((struct sockaddr_in6 *)ia->ifa_addr) ->sin6_addr; if (ad->undefined || memcmp(a, b, sizeof(*a))) { bcopy(b, a, sizeof(*a)); changed = 1; } } if (changed) ad->undefined = 0; break; } if (ia == NULL) ad->undefined = 1; splx(s); } void pf_dynaddr_remove(struct pf_addr_wrap *aw) { if (aw->type != PF_ADDR_DYNIFTL || aw->p.dyn == NULL) return; hook_disestablish(aw->p.dyn->ifp->if_addrhooks, aw->p.dyn->hook_cookie); pool_put(&pf_addr_pl, aw->p.dyn); aw->p.dyn = NULL; } void pf_dynaddr_copyout(struct pf_addr_wrap *aw) { if (aw->type != PF_ADDR_DYNIFTL || aw->p.dyn == NULL) return; bcopy(aw->p.dyn->ifname, aw->v.ifname, sizeof(aw->v.ifname)); aw->p.dyn = (struct pf_addr_dyn *)1; } void pf_print_host(struct pf_addr *addr, u_int16_t p, sa_family_t af) { switch (af) { #ifdef INET case AF_INET: { u_int32_t a = ntohl(addr->addr32[0]); printf("%u.%u.%u.%u", (a>>24)&255, (a>>16)&255, (a>>8)&255, a&255); if (p) { p = ntohs(p); printf(":%u", p); } break; } #endif /* INET */ #ifdef INET6 case AF_INET6: { u_int16_t b; u_int8_t i, curstart = 255, curend = 0, maxstart = 0, maxend = 0; for (i = 0; i < 8; i++) { if (!addr->addr16[i]) { if (curstart == 255) curstart = i; else curend = i; } else { if (curstart) { if ((curend - curstart) > (maxend - maxstart)) { maxstart = curstart; maxend = curend; curstart = 255; } } } } for (i = 0; i < 8; i++) { if (i >= maxstart && i <= maxend) { if (maxend != 7) { if (i == maxstart) printf(":"); } else { if (i == maxend) printf(":"); } } else { b = ntohs(addr->addr16[i]); printf("%x", b); if (i < 7) printf(":"); } } if (p) { p = ntohs(p); printf("[%u]", p); } break; } #endif /* INET6 */ } } void pf_print_state(struct pf_state *s) { switch (s->proto) { case IPPROTO_TCP: printf("TCP "); break; case IPPROTO_UDP: printf("UDP "); break; case IPPROTO_ICMP: printf("ICMP "); break; case IPPROTO_ICMPV6: printf("ICMPV6 "); break; default: printf("%u ", s->proto); break; } pf_print_host(&s->lan.addr, s->lan.port, s->af); printf(" "); pf_print_host(&s->gwy.addr, s->gwy.port, s->af); printf(" "); pf_print_host(&s->ext.addr, s->ext.port, s->af); printf(" [lo=%u high=%u win=%u modulator=%u", s->src.seqlo, s->src.seqhi, s->src.max_win, s->src.seqdiff); if (s->src.wscale && s->dst.wscale) printf(" wscale=%u", s->src.wscale & PF_WSCALE_MASK); printf("]"); printf(" [lo=%u high=%u win=%u modulator=%u", s->dst.seqlo, s->dst.seqhi, s->dst.max_win, s->dst.seqdiff); if (s->src.wscale && s->dst.wscale) printf(" wscale=%u", s->dst.wscale & PF_WSCALE_MASK); printf("]"); printf(" %u:%u", s->src.state, s->dst.state); } void pf_print_flags(u_int8_t f) { if (f) printf(" "); if (f & TH_FIN) printf("F"); if (f & TH_SYN) printf("S"); if (f & TH_RST) printf("R"); if (f & TH_PUSH) printf("P"); if (f & TH_ACK) printf("A"); if (f & TH_URG) printf("U"); if (f & TH_ECE) printf("E"); if (f & TH_CWR) printf("W"); } #define PF_SET_SKIP_STEPS(i) \ do { \ while (head[i] != cur) { \ head[i]->skip[i].ptr = cur; \ head[i] = TAILQ_NEXT(head[i], entries); \ } \ } while (0) void pf_calc_skip_steps(struct pf_rulequeue *rules) { struct pf_rule *cur, *prev, *head[PF_SKIP_COUNT]; int i; cur = TAILQ_FIRST(rules); prev = cur; for (i = 0; i < PF_SKIP_COUNT; ++i) head[i] = cur; while (cur != NULL) { if (cur->ifp != prev->ifp || cur->ifnot != prev->ifnot) PF_SET_SKIP_STEPS(PF_SKIP_IFP); if (cur->direction != prev->direction) PF_SET_SKIP_STEPS(PF_SKIP_DIR); if (cur->af != prev->af) PF_SET_SKIP_STEPS(PF_SKIP_AF); if (cur->proto != prev->proto) PF_SET_SKIP_STEPS(PF_SKIP_PROTO); if (cur->src.addr.type == PF_ADDR_DYNIFTL || prev->src.addr.type == PF_ADDR_DYNIFTL || cur->src.addr.type == PF_ADDR_TABLE || prev->src.addr.type == PF_ADDR_TABLE || cur->src.not != prev->src.not || (cur->src.addr.type == PF_ADDR_NOROUTE) != (prev->src.addr.type == PF_ADDR_NOROUTE) || !PF_AEQ(&cur->src.addr.v.a.addr, &prev->src.addr.v.a.addr, 0) || !PF_AEQ(&cur->src.addr.v.a.mask, &prev->src.addr.v.a.mask, 0)) PF_SET_SKIP_STEPS(PF_SKIP_SRC_ADDR); if (cur->src.port[0] != prev->src.port[0] || cur->src.port[1] != prev->src.port[1] || cur->src.port_op != prev->src.port_op) PF_SET_SKIP_STEPS(PF_SKIP_SRC_PORT); if (cur->dst.addr.type == PF_ADDR_DYNIFTL || prev->dst.addr.type == PF_ADDR_DYNIFTL || cur->dst.addr.type == PF_ADDR_TABLE || prev->dst.addr.type == PF_ADDR_TABLE || cur->dst.not != prev->dst.not || (cur->dst.addr.type == PF_ADDR_NOROUTE) != (prev->dst.addr.type == PF_ADDR_NOROUTE) || !PF_AEQ(&cur->dst.addr.v.a.addr, &prev->dst.addr.v.a.addr, 0) || !PF_AEQ(&cur->dst.addr.v.a.mask, &prev->dst.addr.v.a.mask, 0)) PF_SET_SKIP_STEPS(PF_SKIP_DST_ADDR); if (cur->dst.port[0] != prev->dst.port[0] || cur->dst.port[1] != prev->dst.port[1] || cur->dst.port_op != prev->dst.port_op) PF_SET_SKIP_STEPS(PF_SKIP_DST_PORT); prev = cur; cur = TAILQ_NEXT(cur, entries); } for (i = 0; i < PF_SKIP_COUNT; ++i) PF_SET_SKIP_STEPS(i); } void pf_update_anchor_rules() { struct pf_rule *rule; int i; for (i = 0; i < PF_RULESET_MAX; ++i) TAILQ_FOREACH(rule, pf_main_ruleset.rules[i].active.ptr, entries) if (rule->anchorname[0]) rule->anchor = pf_find_anchor(rule->anchorname); else rule->anchor = NULL; } u_int16_t pf_cksum_fixup(u_int16_t cksum, u_int16_t old, u_int16_t new, u_int8_t udp) { u_int32_t l; if (udp && !cksum) return (0x0000); l = cksum + old - new; l = (l >> 16) + (l & 65535); l = l & 65535; if (udp && !l) return (0xFFFF); return (l); } void pf_change_ap(struct pf_addr *a, u_int16_t *p, u_int16_t *ic, u_int16_t *pc, struct pf_addr *an, u_int16_t pn, u_int8_t u, sa_family_t af) { struct pf_addr ao; u_int16_t po = *p; PF_ACPY(&ao, a, af); PF_ACPY(a, an, af); *p = pn; switch (af) { #ifdef INET case AF_INET: *ic = pf_cksum_fixup(pf_cksum_fixup(*ic, ao.addr16[0], an->addr16[0], 0), ao.addr16[1], an->addr16[1], 0); *p = pn; *pc = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(*pc, ao.addr16[0], an->addr16[0], u), ao.addr16[1], an->addr16[1], u), po, pn, u); break; #endif /* INET */ #ifdef INET6 case AF_INET6: *pc = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup( pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup( pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(*pc, ao.addr16[0], an->addr16[0], u), ao.addr16[1], an->addr16[1], u), ao.addr16[2], an->addr16[2], u), ao.addr16[3], an->addr16[3], u), ao.addr16[4], an->addr16[4], u), ao.addr16[5], an->addr16[5], u), ao.addr16[6], an->addr16[6], u), ao.addr16[7], an->addr16[7], u), po, pn, u); break; #endif /* INET6 */ } } void pf_change_a(u_int32_t *a, u_int16_t *c, u_int32_t an, u_int8_t u) { u_int32_t ao = *a; *a = an; *c = pf_cksum_fixup(pf_cksum_fixup(*c, ao / 65536, an / 65536, u), ao % 65536, an % 65536, u); } #ifdef INET6 void pf_change_a6(struct pf_addr *a, u_int16_t *c, struct pf_addr *an, u_int8_t u) { struct pf_addr ao; PF_ACPY(&ao, a, AF_INET6); PF_ACPY(a, an, AF_INET6); *c = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup( pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup( pf_cksum_fixup(pf_cksum_fixup(*c, ao.addr16[0], an->addr16[0], u), ao.addr16[1], an->addr16[1], u), ao.addr16[2], an->addr16[2], u), ao.addr16[3], an->addr16[3], u), ao.addr16[4], an->addr16[4], u), ao.addr16[5], an->addr16[5], u), ao.addr16[6], an->addr16[6], u), ao.addr16[7], an->addr16[7], u); } #endif /* INET6 */ void pf_change_icmp(struct pf_addr *ia, u_int16_t *ip, struct pf_addr *oa, struct pf_addr *na, u_int16_t np, u_int16_t *pc, u_int16_t *h2c, u_int16_t *ic, u_int16_t *hc, u_int8_t u, sa_family_t af) { struct pf_addr oia, ooa; u_int32_t opc; u_int16_t oip = *ip; PF_ACPY(&oia, ia, af); PF_ACPY(&ooa, oa, af); if (pc != NULL) opc = *pc; /* Change inner protocol port, fix inner protocol checksum. */ *ip = np; if (pc != NULL) *pc = pf_cksum_fixup(*pc, oip, *ip, u); *ic = pf_cksum_fixup(*ic, oip, *ip, 0); if (pc != NULL) *ic = pf_cksum_fixup(*ic, opc, *pc, 0); PF_ACPY(ia, na, af); /* Change inner ip address, fix inner ipv4 and icmp checksums. */ switch (af) { #ifdef INET case AF_INET: { u_int32_t oh2c = *h2c; *h2c = pf_cksum_fixup(pf_cksum_fixup(*h2c, oia.addr16[0], ia->addr16[0], 0), oia.addr16[1], ia->addr16[1], 0); *ic = pf_cksum_fixup(pf_cksum_fixup(*ic, oia.addr16[0], ia->addr16[0], 0), oia.addr16[1], ia->addr16[1], 0); *ic = pf_cksum_fixup(*ic, oh2c, *h2c, 0); break; } #endif /* INET */ #ifdef INET6 case AF_INET6: *ic = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup( pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup( pf_cksum_fixup(pf_cksum_fixup(*ic, oia.addr16[0], ia->addr16[0], u), oia.addr16[1], ia->addr16[1], u), oia.addr16[2], ia->addr16[2], u), oia.addr16[3], ia->addr16[3], u), oia.addr16[4], ia->addr16[4], u), oia.addr16[5], ia->addr16[5], u), oia.addr16[6], ia->addr16[6], u), oia.addr16[7], ia->addr16[7], u); break; #endif /* INET6 */ } /* Change outer ip address, fix outer ipv4 or icmpv6 checksum. */ PF_ACPY(oa, na, af); switch (af) { #ifdef INET case AF_INET: *hc = pf_cksum_fixup(pf_cksum_fixup(*hc, ooa.addr16[0], oa->addr16[0], 0), ooa.addr16[1], oa->addr16[1], 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: *ic = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup( pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup( pf_cksum_fixup(pf_cksum_fixup(*ic, ooa.addr16[0], oa->addr16[0], u), ooa.addr16[1], oa->addr16[1], u), ooa.addr16[2], oa->addr16[2], u), ooa.addr16[3], oa->addr16[3], u), ooa.addr16[4], oa->addr16[4], u), ooa.addr16[5], oa->addr16[5], u), ooa.addr16[6], oa->addr16[6], u), ooa.addr16[7], oa->addr16[7], u); break; #endif /* INET6 */ } } void pf_send_reset(int off, struct tcphdr *th, struct pf_pdesc *pd, sa_family_t af, u_int8_t return_ttl, struct pf_rule *r) { struct mbuf *m; struct m_tag *mtag; int len; #ifdef INET struct ip *h2; #endif /* INET */ #ifdef INET6 struct ip6_hdr *h2_6; #endif /* INET6 */ struct tcphdr *th2; switch (af) { #ifdef INET case AF_INET: len = sizeof(struct ip) + sizeof(struct tcphdr); break; #endif /* INET */ #ifdef INET6 case AF_INET6: len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr); break; #endif /* INET6 */ } /* don't reply to RST packets */ if (th->th_flags & TH_RST) return; /* create outgoing mbuf */ mtag = m_tag_get(PACKET_TAG_PF_GENERATED, 0, M_NOWAIT); if (mtag == NULL) return; m = m_gethdr(M_DONTWAIT, MT_HEADER); if (m == NULL) { m_tag_free(mtag); return; } m_tag_prepend(m, mtag); m->m_data += max_linkhdr; m->m_pkthdr.len = m->m_len = len; m->m_pkthdr.rcvif = NULL; bzero(m->m_data, len); switch (af) { #ifdef INET case AF_INET: h2 = mtod(m, struct ip *); /* IP header fields included in the TCP checksum */ h2->ip_p = IPPROTO_TCP; h2->ip_len = htons(sizeof(*th2)); h2->ip_src.s_addr = pd->dst->v4.s_addr; h2->ip_dst.s_addr = pd->src->v4.s_addr; th2 = (struct tcphdr *)((caddr_t)h2 + sizeof(struct ip)); break; #endif /* INET */ #ifdef INET6 case AF_INET6: h2_6 = mtod(m, struct ip6_hdr *); /* IP header fields included in the TCP checksum */ h2_6->ip6_nxt = IPPROTO_TCP; h2_6->ip6_plen = htons(sizeof(*th2)); memcpy(&h2_6->ip6_src, pd->dst, sizeof(struct in6_addr)); memcpy(&h2_6->ip6_dst, pd->src, sizeof(struct in6_addr)); th2 = (struct tcphdr *)((caddr_t)h2_6 + sizeof(struct ip6_hdr)); break; #endif /* INET6 */ } /* TCP header */ th2->th_sport = th->th_dport; th2->th_dport = th->th_sport; if (th->th_flags & TH_ACK) { th2->th_seq = th->th_ack; th2->th_flags = TH_RST; } else { int tlen = pd->p_len; if (th->th_flags & TH_SYN) tlen++; if (th->th_flags & TH_FIN) tlen++; th2->th_ack = htonl(ntohl(th->th_seq) + tlen); th2->th_flags = TH_RST | TH_ACK; } th2->th_off = sizeof(*th2) >> 2; #ifdef ALTQ if (r->qid) { struct altq_tag *atag; mtag = m_tag_get(PACKET_TAG_PF_QID, sizeof(*atag), M_NOWAIT); if (mtag != NULL) { atag = (struct altq_tag *)(mtag + 1); atag->qid = r->qid; /* add hints for ecn */ atag->af = af; atag->hdr = mtod(m, struct ip *); m_tag_prepend(m, mtag); } } #endif switch (af) { #ifdef INET case AF_INET: /* TCP checksum */ th2->th_sum = in_cksum(m, len); /* Finish the IP header */ h2->ip_v = 4; h2->ip_hl = sizeof(*h2) >> 2; if (!return_ttl) return_ttl = ip_defttl; h2->ip_ttl = return_ttl; h2->ip_sum = 0; h2->ip_len = len; h2->ip_off = ip_mtudisc ? IP_DF : 0; ip_output(m, (void *)NULL, (void *)NULL, 0, (void *)NULL, (void *)NULL); break; #endif /* INET */ #ifdef INET6 case AF_INET6: /* TCP checksum */ th2->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(struct ip6_hdr), sizeof(*th)); h2_6->ip6_vfc |= IPV6_VERSION; if (!return_ttl) return_ttl = IPV6_DEFHLIM; h2_6->ip6_hlim = return_ttl; ip6_output(m, NULL, NULL, 0, NULL, NULL); #endif /* INET6 */ } } void pf_send_icmp(struct mbuf *m, u_int8_t type, u_int8_t code, sa_family_t af, struct pf_rule *r) { struct m_tag *mtag; struct mbuf *m0; mtag = m_tag_get(PACKET_TAG_PF_GENERATED, 0, M_NOWAIT); if (mtag == NULL) return; m0 = m_copy(m, 0, M_COPYALL); if (m0 == NULL) { m_tag_free(mtag); return; } m_tag_prepend(m0, mtag); #ifdef ALTQ if (r->qid) { struct altq_tag *atag; mtag = m_tag_get(PACKET_TAG_PF_QID, sizeof(*atag), M_NOWAIT); if (mtag != NULL) { atag = (struct altq_tag *)(mtag + 1); atag->qid = r->qid; /* add hints for ecn */ atag->af = af; atag->hdr = mtod(m0, struct ip *); m_tag_prepend(m0, mtag); } } #endif switch (af) { #ifdef INET case AF_INET: icmp_error(m0, type, code, 0, 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: icmp6_error(m0, type, code, 0); break; #endif /* INET6 */ } } /* * Return 1 if the addresses a and b match (with mask m), otherwise return 0. * If n is 0, they match if they are equal. If n is != 0, they match if they * are different. */ int pf_match_addr(u_int8_t n, struct pf_addr *a, struct pf_addr *m, struct pf_addr *b, sa_family_t af) { int match = 0; switch (af) { #ifdef INET case AF_INET: if ((a->addr32[0] & m->addr32[0]) == (b->addr32[0] & m->addr32[0])) match++; break; #endif /* INET */ #ifdef INET6 case AF_INET6: if (((a->addr32[0] & m->addr32[0]) == (b->addr32[0] & m->addr32[0])) && ((a->addr32[1] & m->addr32[1]) == (b->addr32[1] & m->addr32[1])) && ((a->addr32[2] & m->addr32[2]) == (b->addr32[2] & m->addr32[2])) && ((a->addr32[3] & m->addr32[3]) == (b->addr32[3] & m->addr32[3]))) match++; break; #endif /* INET6 */ } if (match) { if (n) return (0); else return (1); } else { if (n) return (1); else return (0); } } int pf_match(u_int8_t op, u_int16_t a1, u_int16_t a2, u_int16_t p) { switch (op) { case PF_OP_IRG: return ((p > a1) && (p < a2)); case PF_OP_XRG: return ((p < a1) || (p > a2)); case PF_OP_RRG: return ((p >= a1) && (p <= a2)); case PF_OP_EQ: return (p == a1); case PF_OP_NE: return (p != a1); case PF_OP_LT: return (p < a1); case PF_OP_LE: return (p <= a1); case PF_OP_GT: return (p > a1); case PF_OP_GE: return (p >= a1); } return (0); /* never reached */ } int pf_match_port(u_int8_t op, u_int16_t a1, u_int16_t a2, u_int16_t p) { NTOHS(a1); NTOHS(a2); NTOHS(p); return (pf_match(op, a1, a2, p)); } int pf_match_uid(u_int8_t op, uid_t a1, uid_t a2, uid_t u) { if (u == UID_MAX && op != PF_OP_EQ && op != PF_OP_NE) return (0); return (pf_match(op, a1, a2, u)); } int pf_match_gid(u_int8_t op, gid_t a1, gid_t a2, gid_t g) { if (g == GID_MAX && op != PF_OP_EQ && op != PF_OP_NE) return (0); return (pf_match(op, a1, a2, g)); } #define PF_STEP_INTO_ANCHOR(r, a, s, n) \ do { \ if ((r) == NULL || (r)->anchor == NULL || \ (s) != NULL || (a) != NULL) \ panic("PF_STEP_INTO_ANCHOR"); \ (a) = (r); \ (s) = TAILQ_FIRST(&(r)->anchor->rulesets); \ (r) = NULL; \ while ((s) != NULL && ((r) = \ TAILQ_FIRST((s)->rules[n].active.ptr)) == NULL) \ (s) = TAILQ_NEXT((s), entries); \ if ((r) == NULL) { \ (r) = TAILQ_NEXT((a), entries); \ (a) = NULL; \ } \ } while (0) #define PF_STEP_OUT_OF_ANCHOR(r, a, s, n) \ do { \ if ((r) != NULL || (a) == NULL || (s) == NULL) \ panic("PF_STEP_OUT_OF_ANCHOR"); \ (s) = TAILQ_NEXT((s), entries); \ while ((s) != NULL && ((r) = \ TAILQ_FIRST((s)->rules[n].active.ptr)) == NULL) \ (s) = TAILQ_NEXT((s), entries); \ if ((r) == NULL) { \ (r) = TAILQ_NEXT((a), entries); \ (a) = NULL; \ } \ } while (0) #ifdef INET6 void pf_poolmask(struct pf_addr *naddr, struct pf_addr *raddr, struct pf_addr *rmask, struct pf_addr *saddr, sa_family_t af) { switch (af) { #ifdef INET case AF_INET: naddr->addr32[0] = (raddr->addr32[0] & rmask->addr32[0]) | ((rmask->addr32[0] ^ 0xffffffff ) & saddr->addr32[0]); break; #endif /* INET */ case AF_INET6: naddr->addr32[0] = (raddr->addr32[0] & rmask->addr32[0]) | ((rmask->addr32[0] ^ 0xffffffff ) & saddr->addr32[0]); naddr->addr32[1] = (raddr->addr32[1] & rmask->addr32[1]) | ((rmask->addr32[1] ^ 0xffffffff ) & saddr->addr32[1]); naddr->addr32[2] = (raddr->addr32[2] & rmask->addr32[2]) | ((rmask->addr32[2] ^ 0xffffffff ) & saddr->addr32[2]); naddr->addr32[3] = (raddr->addr32[3] & rmask->addr32[3]) | ((rmask->addr32[3] ^ 0xffffffff ) & saddr->addr32[3]); break; } } void pf_addr_inc(struct pf_addr *addr, u_int8_t af) { switch (af) { #ifdef INET case AF_INET: addr->addr32[0] = htonl(ntohl(addr->addr32[0]) + 1); break; #endif /* INET */ case AF_INET6: if (addr->addr32[3] == 0xffffffff) { addr->addr32[3] = 0; if (addr->addr32[2] == 0xffffffff) { addr->addr32[2] = 0; if (addr->addr32[1] == 0xffffffff) { addr->addr32[1] = 0; addr->addr32[0] = htonl(ntohl(addr->addr32[0]) + 1); } else addr->addr32[1] = htonl(ntohl(addr->addr32[1]) + 1); } else addr->addr32[2] = htonl(ntohl(addr->addr32[2]) + 1); } else addr->addr32[3] = htonl(ntohl(addr->addr32[3]) + 1); break; } } #endif /* INET6 */ #define mix(a,b,c) \ do { \ a -= b; a -= c; a ^= (c >> 13); \ b -= c; b -= a; b ^= (a << 8); \ c -= a; c -= b; c ^= (b >> 13); \ a -= b; a -= c; a ^= (c >> 12); \ b -= c; b -= a; b ^= (a << 16); \ c -= a; c -= b; c ^= (b >> 5); \ a -= b; a -= c; a ^= (c >> 3); \ b -= c; b -= a; b ^= (a << 10); \ c -= a; c -= b; c ^= (b >> 15); \ } while (0) /* * hash function based on bridge_hash in if_bridge.c */ void pf_hash(struct pf_addr *inaddr, struct pf_addr *hash, struct pf_poolhashkey *key, sa_family_t af) { u_int32_t a = 0x9e3779b9, b = 0x9e3779b9, c = key->key32[0]; switch (af) { #ifdef INET case AF_INET: a += inaddr->addr32[0]; b += key->key32[1]; mix(a, b, c); hash->addr32[0] = c + key->key32[2]; break; #endif /* INET */ #ifdef INET6 case AF_INET6: a += inaddr->addr32[0]; b += inaddr->addr32[2]; mix(a, b, c); hash->addr32[0] = c; a += inaddr->addr32[1]; b += inaddr->addr32[3]; c += key->key32[1]; mix(a, b, c); hash->addr32[1] = c; a += inaddr->addr32[2]; b += inaddr->addr32[1]; c += key->key32[2]; mix(a, b, c); hash->addr32[2] = c; a += inaddr->addr32[3]; b += inaddr->addr32[0]; c += key->key32[3]; mix(a, b, c); hash->addr32[3] = c; break; #endif /* INET6 */ } } int pf_map_addr(u_int8_t af, struct pf_pool *rpool, struct pf_addr *saddr, struct pf_addr *naddr, struct pf_addr *init_addr) { unsigned char hash[16]; struct pf_addr *raddr = &rpool->cur->addr.addr.v.a.addr; struct pf_addr *rmask = &rpool->cur->addr.addr.v.a.mask; if (rpool->cur->addr.addr.type == PF_ADDR_NOROUTE || rpool->cur->addr.addr.type == PF_ADDR_TABLE) return (1); if (rpool->cur->addr.addr.type == PF_ADDR_DYNIFTL && rpool->cur->addr.addr.p.dyn->undefined) return (1); switch (rpool->opts & PF_POOL_TYPEMASK) { case PF_POOL_NONE: PF_ACPY(naddr, raddr, af); break; case PF_POOL_BITMASK: PF_POOLMASK(naddr, raddr, rmask, saddr, af); break; case PF_POOL_RANDOM: if (init_addr != NULL && PF_AZERO(init_addr, af)) { switch (af) { #ifdef INET case AF_INET: rpool->counter.addr32[0] = arc4random(); break; #endif /* INET */ #ifdef INET6 case AF_INET6: if (rmask->addr32[3] != 0xffffffff) rpool->counter.addr32[3] = arc4random(); else break; if (rmask->addr32[2] != 0xffffffff) rpool->counter.addr32[2] = arc4random(); else break; if (rmask->addr32[1] != 0xffffffff) rpool->counter.addr32[1] = arc4random(); else break; if (rmask->addr32[0] != 0xffffffff) rpool->counter.addr32[0] = arc4random(); break; #endif /* INET6 */ } PF_POOLMASK(naddr, raddr, rmask, &rpool->counter, af); PF_ACPY(init_addr, naddr, af); } else { PF_AINC(&rpool->counter, af); PF_POOLMASK(naddr, raddr, rmask, &rpool->counter, af); } break; case PF_POOL_SRCHASH: pf_hash(saddr, (struct pf_addr *)&hash, &rpool->key, af); PF_POOLMASK(naddr, raddr, rmask, (struct pf_addr *)&hash, af); break; case PF_POOL_ROUNDROBIN: if (pf_match_addr(0, &rpool->cur->addr.addr.v.a.addr, &rpool->cur->addr.addr.v.a.mask, &rpool->counter, af)) { PF_ACPY(naddr, &rpool->counter, af); PF_AINC(&rpool->counter, af); } else { if ((rpool->cur = TAILQ_NEXT(rpool->cur, entries)) == NULL) rpool->cur = TAILQ_FIRST(&rpool->list); PF_ACPY(naddr, &rpool->cur->addr.addr.v.a.addr, af); PF_ACPY(&rpool->counter, &rpool->cur->addr.addr.v.a.addr, af); PF_AINC(&rpool->counter, af); } break; } if (pf_status.debug >= PF_DEBUG_MISC && (rpool->opts & PF_POOL_TYPEMASK) != PF_POOL_NONE) { printf("pf_map_addr: selected address: "); pf_print_host(naddr, 0, af); printf("\n"); } return (0); } int pf_get_sport(sa_family_t af, u_int8_t proto, struct pf_pool *rpool, struct pf_addr *saddr, struct pf_addr *daddr, u_int16_t dport, struct pf_addr *naddr, u_int16_t *nport, u_int16_t low, u_int16_t high) { struct pf_tree_node key; struct pf_addr init_addr; int step; u_int16_t cut; bzero(&init_addr, sizeof(init_addr)); if (pf_map_addr(af, rpool, saddr, naddr, &init_addr)) return (1); do { key.af = af; key.proto = proto; PF_ACPY(&key.addr[0], daddr, key.af); PF_ACPY(&key.addr[1], naddr, key.af); key.port[0] = dport; /* * port search; start random, step; * similar 2 portloop in in_pcbbind */ if (!(proto == IPPROTO_TCP || proto == IPPROTO_UDP)) { key.port[1] = 0; if (pf_find_state(&tree_ext_gwy, &key) == NULL) return (0); } else if (rpool->opts & PF_POOL_STATICPORT) { key.port[1] = *nport; if (pf_find_state(&tree_ext_gwy, &key) == NULL) return (0); } else if (low == 0 && high == 0) { key.port[1] = *nport; if (pf_find_state(&tree_ext_gwy, &key) == NULL) { NTOHS(*nport); return (0); } } else if (low == high) { key.port[1] = htons(low); if (pf_find_state(&tree_ext_gwy, &key) == NULL) { *nport = low; return (0); } } else { if (low < high) { step = 1; cut = arc4random() % (1 + high - low) + low; } else { step = -1; cut = arc4random() % (1 + low - high) + high; } *nport = cut - step; do { *nport += step; key.port[1] = htons(*nport); if (pf_find_state(&tree_ext_gwy, &key) == NULL) return (0); } while (*nport != low && *nport != high); step = -step; *nport = cut; do { *nport += step; key.port[1] = htons(*nport); if (pf_find_state(&tree_ext_gwy, &key) == NULL) return (0); } while (*nport != low && *nport != high); } switch (rpool->opts & PF_POOL_TYPEMASK) { case PF_POOL_RANDOM: case PF_POOL_ROUNDROBIN: if (pf_map_addr(af, rpool, saddr, naddr, &init_addr)) return (1); break; case PF_POOL_NONE: case PF_POOL_SRCHASH: case PF_POOL_BITMASK: default: return (1); break; } } while (! PF_AEQ(&init_addr, naddr, af) ); return (1); /* none available */ } struct pf_rule * pf_match_translation(int direction, struct ifnet *ifp, u_int8_t proto, struct pf_addr *saddr, u_int16_t sport, struct pf_addr *daddr, u_int16_t dport, sa_family_t af, int rs_num) { struct pf_rule *r, *rm = NULL, *anchorrule = NULL; struct pf_ruleset *ruleset = NULL; r = TAILQ_FIRST(pf_main_ruleset.rules[rs_num].active.ptr); while (r && rm == NULL) { struct pf_rule_addr *src = NULL, *dst = NULL; if (r->action == PF_BINAT && direction == PF_IN) { src = &r->dst; if (r->rpool.cur != NULL) dst = &r->rpool.cur->addr; } else { src = &r->src; dst = &r->dst; } r->evaluations++; if (r->ifp != NULL && ((r->ifp != ifp && !r->ifnot) || (r->ifp == ifp && r->ifnot))) r = r->skip[PF_SKIP_IFP].ptr; else if (r->direction && r->direction != direction) r = r->skip[PF_SKIP_DIR].ptr; else if (r->af && r->af != af) r = r->skip[PF_SKIP_AF].ptr; else if (r->proto && r->proto != proto) r = r->skip[PF_SKIP_PROTO].ptr; else if (PF_MISMATCHAW(&src->addr, saddr, af, src->not)) r = r->skip[src == &r->src ? PF_SKIP_SRC_ADDR : PF_SKIP_DST_ADDR].ptr; else if (src->port_op && !pf_match_port(src->port_op, src->port[0], src->port[1], sport)) r = r->skip[src == &r->src ? PF_SKIP_SRC_PORT : PF_SKIP_DST_PORT].ptr; else if (dst != NULL && PF_MISMATCHAW(&dst->addr, daddr, af, dst->not)) r = dst == &r->dst ? r->skip[PF_SKIP_DST_ADDR].ptr : TAILQ_NEXT(r, entries); else if (dst != NULL && dst->port_op && !pf_match_port(dst->port_op, dst->port[0], dst->port[1], dport)) r = dst == &r->dst ? r->skip[PF_SKIP_DST_PORT].ptr : TAILQ_NEXT(r, entries); else if (r->anchorname[0] && r->anchor == NULL) r = TAILQ_NEXT(r, entries); else if (r->anchor == NULL) rm = r; else PF_STEP_INTO_ANCHOR(r, anchorrule, ruleset, rs_num); if (r == NULL && anchorrule != NULL) PF_STEP_OUT_OF_ANCHOR(r, anchorrule, ruleset, rs_num); } if (rm != NULL && (rm->action == PF_NONAT || rm->action == PF_NORDR || rm->action == PF_NOBINAT)) return (NULL); return (rm); } struct pf_rule * pf_get_translation(int direction, struct ifnet *ifp, u_int8_t proto, struct pf_addr *saddr, u_int16_t sport, struct pf_addr *daddr, u_int16_t dport, struct pf_addr *naddr, u_int16_t *nport, sa_family_t af) { struct pf_rule *r = NULL; if (direction == PF_OUT) { r = pf_match_translation(direction, ifp, proto, saddr, sport, daddr, dport, af, PF_RULESET_BINAT); if (r == NULL) r = pf_match_translation(direction, ifp, proto, saddr, sport, daddr, dport, af, PF_RULESET_NAT); } else { r = pf_match_translation(direction, ifp, proto, saddr, sport, daddr, dport, af, PF_RULESET_RDR); if (r == NULL) r = pf_match_translation(direction, ifp, proto, saddr, sport, daddr, dport, af, PF_RULESET_BINAT); } if (r != NULL) { switch (r->action) { case PF_NONAT: case PF_NOBINAT: case PF_NORDR: return (NULL); break; case PF_NAT: if (pf_get_sport(af, proto, &r->rpool, saddr, daddr, dport, naddr, nport, r->rpool.proxy_port[0], r->rpool.proxy_port[1])) { DPFPRINTF(PF_DEBUG_MISC, ("pf: NAT proxy port allocation " "(%u-%u) failed\n", r->rpool.proxy_port[0], r->rpool.proxy_port[1])); return (NULL); } break; case PF_BINAT: switch (direction) { case PF_OUT: if (r->rpool.cur->addr.addr.type == PF_ADDR_DYNIFTL && r->rpool.cur->addr.addr.p.dyn->undefined) return (NULL); else PF_POOLMASK(naddr, &r->rpool.cur->addr.addr.v.a.addr, &r->rpool.cur->addr.addr.v.a.mask, saddr, af); break; case PF_IN: if (r->src.addr.type == PF_ADDR_DYNIFTL && r->src.addr.p.dyn->undefined) return (NULL); else PF_POOLMASK(naddr, &r->src.addr.v.a.addr, &r->src.addr.v.a.mask, saddr, af); break; } break; case PF_RDR: { if (pf_map_addr(r->af, &r->rpool, &r->src.addr.v.a.addr, naddr, NULL)) return (NULL); if (r->rpool.proxy_port[1]) { u_int32_t tmp_nport; tmp_nport = ((ntohs(dport) - ntohs(r->dst.port[0])) % (r->rpool.proxy_port[1] - r->rpool.proxy_port[0] + 1)) + r->rpool.proxy_port[0]; /* wrap around if necessary */ if (tmp_nport > 65535) tmp_nport -= 65535; *nport = htons((u_int16_t)tmp_nport); } else if (r->rpool.proxy_port[0]) *nport = htons(r->rpool.proxy_port[0]); break; } default: return (NULL); break; } } return (r); } int pf_socket_lookup(uid_t *uid, gid_t *gid, int direction, sa_family_t af, int proto, struct pf_pdesc *pd) { struct pf_addr *saddr, *daddr; u_int16_t sport, dport; struct inpcbtable *tb; struct inpcb *inp; *uid = UID_MAX; *gid = GID_MAX; switch (proto) { case IPPROTO_TCP: sport = pd->hdr.tcp->th_sport; dport = pd->hdr.tcp->th_dport; tb = &tcbtable; break; case IPPROTO_UDP: sport = pd->hdr.udp->uh_sport; dport = pd->hdr.udp->uh_dport; tb = &udbtable; break; default: return (0); } if (direction == PF_IN) { saddr = pd->src; daddr = pd->dst; } else { u_int16_t p; p = sport; sport = dport; dport = p; saddr = pd->dst; daddr = pd->src; } switch(af) { case AF_INET: inp = in_pcbhashlookup(tb, saddr->v4, sport, daddr->v4, dport); if (inp == NULL) { inp = in_pcblookup(tb, &saddr->v4, sport, &daddr->v4, dport, INPLOOKUP_WILDCARD); if (inp == NULL) return (0); } break; #ifdef INET6 case AF_INET6: inp = in6_pcbhashlookup(tb, &saddr->v6, sport, &daddr->v6, dport); if (inp == NULL) { inp = in_pcblookup(tb, &saddr->v6, sport, &daddr->v6, dport, INPLOOKUP_WILDCARD | INPLOOKUP_IPV6); if (inp == NULL) return (0); } break; #endif /* INET6 */ default: return (0); } *uid = inp->inp_socket->so_euid; *gid = inp->inp_socket->so_egid; return (1); } u_int8_t pf_get_wscale(struct mbuf *m, int off, u_int16_t th_off, sa_family_t af) { int hlen; u_int8_t hdr[60]; u_int8_t *opt, optlen; u_int8_t wscale = 0; hlen = th_off << 2; /* hlen <= sizeof(hdr) */ if (hlen <= sizeof(struct tcphdr)) return (0); if (!pf_pull_hdr(m, off, hdr, hlen, NULL, NULL, af)) return (0); opt = hdr + sizeof(struct tcphdr); hlen -= sizeof(struct tcphdr); while (hlen >= 3) { switch (*opt) { case TCPOPT_EOL: case TCPOPT_NOP: ++opt; --hlen; break; case TCPOPT_WINDOW: wscale = opt[2]; if (wscale > TCP_MAX_WINSHIFT) wscale = TCP_MAX_WINSHIFT; wscale |= PF_WSCALE_FLAG; /* fallthrough */ default: optlen = opt[1]; if (optlen < 2) optlen = 2; hlen -= optlen; opt += optlen; } } return (wscale); } int pf_test_tcp(struct pf_rule **rm, struct pf_state **sm, int direction, struct ifnet *ifp, struct mbuf *m, int ipoff, int off, void *h, struct pf_pdesc *pd) { struct pf_rule *nat = NULL, *rdr = NULL; struct pf_addr *saddr = pd->src, *daddr = pd->dst; struct pf_addr baddr, naddr; struct tcphdr *th = pd->hdr.tcp; u_int16_t bport, nport = 0; sa_family_t af = pd->af; int lookup = -1; uid_t uid; gid_t gid; struct pf_rule *r, *rs = &pf_default_rule, *anchorrule = NULL; struct pf_ruleset *ruleset = NULL; u_short reason; int rewrite = 0; if (direction == PF_OUT) { bport = nport = th->th_sport; /* check outgoing packet for BINAT/NAT */ if ((nat = pf_get_translation(PF_OUT, ifp, IPPROTO_TCP, saddr, th->th_sport, daddr, th->th_dport, &naddr, &nport, af)) != NULL) { PF_ACPY(&baddr, saddr, af); pf_change_ap(saddr, &th->th_sport, pd->ip_sum, &th->th_sum, &naddr, nport, 0, af); rewrite++; } } else { bport = nport = th->th_dport; /* check incoming packet for BINAT/RDR */ if ((rdr = pf_get_translation(PF_IN, ifp, IPPROTO_TCP, saddr, th->th_sport, daddr, th->th_dport, &naddr, &nport, af)) != NULL) { PF_ACPY(&baddr, daddr, af); pf_change_ap(daddr, &th->th_dport, pd->ip_sum, &th->th_sum, &naddr, nport, 0, af); rewrite++; } } r = TAILQ_FIRST(pf_main_ruleset.rules[PF_RULESET_FILTER].active.ptr); while (r != NULL) { r->evaluations++; if (r->ifp != NULL && ((r->ifp != ifp && !r->ifnot) || (r->ifp == ifp && r->ifnot))) r = r->skip[PF_SKIP_IFP].ptr; else if (r->direction && r->direction != direction) r = r->skip[PF_SKIP_DIR].ptr; else if (r->af && r->af != af) r = r->skip[PF_SKIP_AF].ptr; else if (r->proto && r->proto != IPPROTO_TCP) r = r->skip[PF_SKIP_PROTO].ptr; else if (PF_MISMATCHAW(&r->src.addr, saddr, af, r->src.not)) r = r->skip[PF_SKIP_SRC_ADDR].ptr; else if (r->src.port_op && !pf_match_port(r->src.port_op, r->src.port[0], r->src.port[1], th->th_sport)) r = r->skip[PF_SKIP_SRC_PORT].ptr; else if (PF_MISMATCHAW(&r->dst.addr, daddr, af, r->dst.not)) r = r->skip[PF_SKIP_DST_ADDR].ptr; else if (r->dst.port_op && !pf_match_port(r->dst.port_op, r->dst.port[0], r->dst.port[1], th->th_dport)) r = r->skip[PF_SKIP_DST_PORT].ptr; else if (r->tos && !(r->tos & pd->tos)) r = TAILQ_NEXT(r, entries); else if (r->rule_flag & PFRULE_FRAGMENT) r = TAILQ_NEXT(r, entries); else if ((r->flagset & th->th_flags) != r->flags) r = TAILQ_NEXT(r, entries); else if (r->uid.op && (lookup != -1 || (lookup = pf_socket_lookup(&uid, &gid, direction, af, IPPROTO_TCP, pd), 1)) && !pf_match_uid(r->uid.op, r->uid.uid[0], r->uid.uid[1], uid)) r = TAILQ_NEXT(r, entries); else if (r->gid.op && (lookup != -1 || (lookup = pf_socket_lookup(&uid, &gid, direction, af, IPPROTO_TCP, pd), 1)) && !pf_match_gid(r->gid.op, r->gid.gid[0], r->gid.gid[1], gid)) r = TAILQ_NEXT(r, entries); else if (r->anchorname[0] && r->anchor == NULL) r = TAILQ_NEXT(r, entries); else { if (r->anchor == NULL) { *rm = r; rs = (anchorrule == NULL ? r : anchorrule); if ((*rm)->quick) break; r = TAILQ_NEXT(r, entries); } else PF_STEP_INTO_ANCHOR(r, anchorrule, ruleset, PF_RULESET_FILTER); } if (r == NULL && anchorrule != NULL) PF_STEP_OUT_OF_ANCHOR(r, anchorrule, ruleset, PF_RULESET_FILTER); } r = *rm; r->packets++; r->bytes += pd->tot_len; if (rs != r) { rs->packets++; rs->bytes += pd->tot_len; } REASON_SET(&reason, PFRES_MATCH); if (r->log) { if (rewrite) m_copyback(m, off, sizeof(*th), (caddr_t)th); PFLOG_PACKET(ifp, h, m, af, direction, reason, rs); } if ((r->action == PF_DROP) && ((r->rule_flag & PFRULE_RETURNRST) || (r->rule_flag & PFRULE_RETURNICMP) || (r->rule_flag & PFRULE_RETURN))) { /* undo NAT/RST changes, if they have taken place */ if (nat != NULL) { pf_change_ap(saddr, &th->th_sport, pd->ip_sum, &th->th_sum, &baddr, bport, 0, af); rewrite++; } else if (rdr != NULL) { pf_change_ap(daddr, &th->th_dport, pd->ip_sum, &th->th_sum, &baddr, bport, 0, af); rewrite++; } if ((r->rule_flag & PFRULE_RETURNRST) || (r->rule_flag & PFRULE_RETURN)) pf_send_reset(off, th, pd, af, r->return_ttl, r); else if ((af == AF_INET) && r->return_icmp) pf_send_icmp(m, r->return_icmp >> 8, r->return_icmp & 255, af, r); else if ((af == AF_INET6) && r->return_icmp6) pf_send_icmp(m, r->return_icmp6 >> 8, r->return_icmp6 & 255, af, r); } if (r->action == PF_DROP) return (PF_DROP); if (r->keep_state || nat != NULL || rdr != NULL) { /* create new state */ u_int16_t len; struct pf_state *s = NULL; len = pd->tot_len - off - (th->th_off << 2); if (!r->max_states || r->states < r->max_states) s = pool_get(&pf_state_pl, PR_NOWAIT); if (s == NULL) { REASON_SET(&reason, PFRES_MEMORY); return (PF_DROP); } bzero(s, sizeof(*s)); if (rs != NULL) rs->states++; s->rule.ptr = rs; if (nat != NULL) s->nat_rule = nat; else s->nat_rule = rdr; if (s->nat_rule != NULL) s->nat_rule->states++; s->allow_opts = r->allow_opts; s->log = r->log & 2; s->proto = IPPROTO_TCP; s->direction = direction; s->af = af; if (direction == PF_OUT) { PF_ACPY(&s->gwy.addr, saddr, af); s->gwy.port = th->th_sport; /* sport */ PF_ACPY(&s->ext.addr, daddr, af); s->ext.port = th->th_dport; if (nat != NULL) { PF_ACPY(&s->lan.addr, &baddr, af); s->lan.addr = baddr; s->lan.port = bport; } else { PF_ACPY(&s->lan.addr, &s->gwy.addr, af); s->lan.port = s->gwy.port; } } else { PF_ACPY(&s->lan.addr, daddr, af); s->lan.port = th->th_dport; PF_ACPY(&s->ext.addr, saddr, af); s->ext.port = th->th_sport; if (rdr != NULL) { PF_ACPY(&s->gwy.addr, &baddr, af); s->gwy.port = bport; } else { PF_ACPY(&s->gwy.addr, &s->lan.addr, af); s->gwy.port = s->lan.port; } } s->src.seqlo = ntohl(th->th_seq); s->src.seqhi = s->src.seqlo + len + 1; if ((th->th_flags & (TH_SYN|TH_ACK)) == TH_SYN && r->keep_state == PF_STATE_MODULATE) { /* Generate sequence number modulator */ while ((s->src.seqdiff = arc4random()) == 0) ; pf_change_a(&th->th_seq, &th->th_sum, htonl(s->src.seqlo + s->src.seqdiff), 0); rewrite = 1; } else s->src.seqdiff = 0; if (th->th_flags & TH_SYN) { s->src.seqhi++; s->src.wscale = pf_get_wscale(m, off, th->th_off, af); } if (th->th_flags & TH_FIN) s->src.seqhi++; s->src.max_win = MAX(ntohs(th->th_win), 1); s->dst.seqlo = 0; /* Haven't seen these yet */ s->dst.seqhi = 1; s->dst.max_win = 1; s->dst.seqdiff = 0; /* Defer random generation */ s->src.state = TCPS_SYN_SENT; s->dst.state = TCPS_CLOSED; s->creation = time.tv_sec; s->expire = s->creation + TIMEOUT(r, PFTM_TCP_FIRST_PACKET); s->packets = 1; s->bytes = pd->tot_len; if (pf_insert_state(s)) { REASON_SET(&reason, PFRES_MEMORY); pool_put(&pf_state_pl, s); return (PF_DROP); } else *sm = s; } /* copy back packet headers if we performed NAT operations */ if (rewrite) m_copyback(m, off, sizeof(*th), (caddr_t)th); return (PF_PASS); } int pf_test_udp(struct pf_rule **rm, struct pf_state **sm, int direction, struct ifnet *ifp, struct mbuf *m, int ipoff, int off, void *h, struct pf_pdesc *pd) { struct pf_rule *nat = NULL, *rdr = NULL; struct pf_addr *saddr = pd->src, *daddr = pd->dst; struct pf_addr baddr, naddr; struct udphdr *uh = pd->hdr.udp; u_int16_t bport, nport = 0; sa_family_t af = pd->af; int lookup = -1; uid_t uid; gid_t gid; struct pf_rule *r, *rs = &pf_default_rule, *anchorrule = NULL; struct pf_ruleset *ruleset = NULL; u_short reason; int rewrite = 0; if (direction == PF_OUT) { bport = nport = uh->uh_sport; /* check outgoing packet for BINAT/NAT */ if ((nat = pf_get_translation(PF_OUT, ifp, IPPROTO_UDP, saddr, uh->uh_sport, daddr, uh->uh_dport, &naddr, &nport, af)) != NULL) { PF_ACPY(&baddr, saddr, af); pf_change_ap(saddr, &uh->uh_sport, pd->ip_sum, &uh->uh_sum, &naddr, nport, 1, af); rewrite++; } } else { bport = nport = uh->uh_dport; /* check incoming packet for BINAT/RDR */ if ((rdr = pf_get_translation(PF_IN, ifp, IPPROTO_UDP, saddr, uh->uh_sport, daddr, uh->uh_dport, &naddr, &nport, af)) != NULL) { PF_ACPY(&baddr, daddr, af); pf_change_ap(daddr, &uh->uh_dport, pd->ip_sum, &uh->uh_sum, &naddr, nport, 1, af); rewrite++; } } r = TAILQ_FIRST(pf_main_ruleset.rules[PF_RULESET_FILTER].active.ptr); while (r != NULL) { r->evaluations++; if (r->ifp != NULL && ((r->ifp != ifp && !r->ifnot) || (r->ifp == ifp && r->ifnot))) r = r->skip[PF_SKIP_IFP].ptr; else if (r->direction && r->direction != direction) r = r->skip[PF_SKIP_DIR].ptr; else if (r->af && r->af != af) r = r->skip[PF_SKIP_AF].ptr; else if (r->proto && r->proto != IPPROTO_UDP) r = r->skip[PF_SKIP_PROTO].ptr; else if (PF_MISMATCHAW(&r->src.addr, saddr, af, r->src.not)) r = r->skip[PF_SKIP_SRC_ADDR].ptr; else if (r->src.port_op && !pf_match_port(r->src.port_op, r->src.port[0], r->src.port[1], uh->uh_sport)) r = r->skip[PF_SKIP_SRC_PORT].ptr; else if (PF_MISMATCHAW(&r->dst.addr, daddr, af, r->dst.not)) r = r->skip[PF_SKIP_DST_ADDR].ptr; else if (r->dst.port_op && !pf_match_port(r->dst.port_op, r->dst.port[0], r->dst.port[1], uh->uh_dport)) r = r->skip[PF_SKIP_DST_PORT].ptr; else if (r->tos && !(r->tos & pd->tos)) r = TAILQ_NEXT(r, entries); else if (r->rule_flag & PFRULE_FRAGMENT) r = TAILQ_NEXT(r, entries); else if (r->uid.op && (lookup != -1 || (lookup = pf_socket_lookup(&uid, &gid, direction, af, IPPROTO_UDP, pd), 1)) && !pf_match_uid(r->uid.op, r->uid.uid[0], r->uid.uid[1], uid)) r = TAILQ_NEXT(r, entries); else if (r->gid.op && (lookup != -1 || (lookup = pf_socket_lookup(&uid, &gid, direction, af, IPPROTO_UDP, pd), 1)) && !pf_match_gid(r->gid.op, r->gid.gid[0], r->gid.gid[1], gid)) r = TAILQ_NEXT(r, entries); else if (r->anchorname[0] && r->anchor == NULL) r = TAILQ_NEXT(r, entries); else { if (r->anchor == NULL) { *rm = r; rs = (anchorrule == NULL ? r : anchorrule); if ((*rm)->quick) break; r = TAILQ_NEXT(r, entries); } else PF_STEP_INTO_ANCHOR(r, anchorrule, ruleset, PF_RULESET_FILTER); } if (r == NULL && anchorrule != NULL) PF_STEP_OUT_OF_ANCHOR(r, anchorrule, ruleset, PF_RULESET_FILTER); } r = *rm; r->packets++; r->bytes += pd->tot_len; if (rs != r) { rs->packets++; rs->bytes += pd->tot_len; } REASON_SET(&reason, PFRES_MATCH); if (r->log) { if (rewrite) m_copyback(m, off, sizeof(*uh), (caddr_t)uh); PFLOG_PACKET(ifp, h, m, af, direction, reason, rs); } if ((r->action == PF_DROP) && ((r->rule_flag & PFRULE_RETURNICMP) || (r->rule_flag & PFRULE_RETURN))) { /* undo NAT/RST changes, if they have taken place */ if (nat != NULL) { pf_change_ap(saddr, &uh->uh_sport, pd->ip_sum, &uh->uh_sum, &baddr, bport, 1, af); rewrite++; } else if (rdr != NULL) { pf_change_ap(daddr, &uh->uh_dport, pd->ip_sum, &uh->uh_sum, &baddr, bport, 1, af); rewrite++; } if ((af == AF_INET) && r->return_icmp) pf_send_icmp(m, r->return_icmp >> 8, r->return_icmp & 255, af, r); else if ((af == AF_INET6) && r->return_icmp6) pf_send_icmp(m, r->return_icmp6 >> 8, r->return_icmp6 & 255, af, r); } if (r->action == PF_DROP) return (PF_DROP); if (r->keep_state || nat != NULL || rdr != NULL) { /* create new state */ struct pf_state *s = NULL; if (!r->max_states || r->states < r->max_states) s = pool_get(&pf_state_pl, PR_NOWAIT); if (s == NULL) return (PF_DROP); bzero(s, sizeof(*s)); if (rs != NULL) rs->states++; s->rule.ptr = rs; if (nat != NULL) s->nat_rule = nat; else s->nat_rule = rdr; if (s->nat_rule != NULL) s->nat_rule->states++; s->allow_opts = r->allow_opts; s->log = r->log & 2; s->proto = IPPROTO_UDP; s->direction = direction; s->af = af; if (direction == PF_OUT) { PF_ACPY(&s->gwy.addr, saddr, af); s->gwy.port = uh->uh_sport; PF_ACPY(&s->ext.addr, daddr, af); s->ext.port = uh->uh_dport; if (nat != NULL) { PF_ACPY(&s->lan.addr, &baddr, af); s->lan.port = bport; } else { PF_ACPY(&s->lan.addr, &s->gwy.addr, af); s->lan.port = s->gwy.port; } } else { PF_ACPY(&s->lan.addr, daddr, af); s->lan.port = uh->uh_dport; PF_ACPY(&s->ext.addr, saddr, af); s->ext.port = uh->uh_sport; if (rdr != NULL) { PF_ACPY(&s->gwy.addr, &baddr, af); s->gwy.port = bport; } else { PF_ACPY(&s->gwy.addr, &s->lan.addr, af); s->gwy.port = s->lan.port; } } s->src.seqlo = 0; s->src.seqhi = 0; s->src.seqdiff = 0; s->src.max_win = 0; s->src.state = PFUDPS_SINGLE; s->dst.seqlo = 0; s->dst.seqhi = 0; s->dst.seqdiff = 0; s->dst.max_win = 0; s->dst.state = PFUDPS_NO_TRAFFIC; s->creation = time.tv_sec; s->expire = s->creation + TIMEOUT(r, PFTM_UDP_FIRST_PACKET); s->packets = 1; s->bytes = pd->tot_len; if (pf_insert_state(s)) { REASON_SET(&reason, PFRES_MEMORY); pool_put(&pf_state_pl, s); return (PF_DROP); } else *sm = s; } /* copy back packet headers if we performed NAT operations */ if (rewrite) m_copyback(m, off, sizeof(*uh), (caddr_t)uh); return (PF_PASS); } int pf_test_icmp(struct pf_rule **rm, struct pf_state **sm, int direction, struct ifnet *ifp, struct mbuf *m, int ipoff, int off, void *h, struct pf_pdesc *pd) { struct pf_rule *nat = NULL, *rdr = NULL; struct pf_addr *saddr = pd->src, *daddr = pd->dst; struct pf_addr baddr, naddr; struct pf_rule *r, *rs = &pf_default_rule, *anchorrule = NULL; struct pf_ruleset *ruleset = NULL; u_short reason; u_int16_t icmpid; sa_family_t af = pd->af; u_int8_t icmptype, icmpcode; int state_icmp = 0; #ifdef INET6 int rewrite = 0; #endif /* INET6 */ switch (pd->proto) { #ifdef INET case IPPROTO_ICMP: icmptype = pd->hdr.icmp->icmp_type; icmpcode = pd->hdr.icmp->icmp_code; icmpid = pd->hdr.icmp->icmp_id; if (icmptype == ICMP_UNREACH || icmptype == ICMP_SOURCEQUENCH || icmptype == ICMP_REDIRECT || icmptype == ICMP_TIMXCEED || icmptype == ICMP_PARAMPROB) state_icmp++; break; #endif /* INET */ #ifdef INET6 case IPPROTO_ICMPV6: icmptype = pd->hdr.icmp6->icmp6_type; icmpcode = pd->hdr.icmp6->icmp6_code; icmpid = pd->hdr.icmp6->icmp6_id; if (icmptype == ICMP6_DST_UNREACH || icmptype == ICMP6_PACKET_TOO_BIG || icmptype == ICMP6_TIME_EXCEEDED || icmptype == ICMP6_PARAM_PROB) state_icmp++; break; #endif /* INET6 */ } if (direction == PF_OUT) { /* check outgoing packet for BINAT/NAT */ if ((nat = pf_get_translation(PF_OUT, ifp, pd->proto, saddr, 0, daddr, 0, &naddr, NULL, af)) != NULL) { PF_ACPY(&baddr, saddr, af); switch (af) { #ifdef INET case AF_INET: pf_change_a(&saddr->v4.s_addr, pd->ip_sum, naddr.v4.s_addr, 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: pf_change_a6(saddr, &pd->hdr.icmp6->icmp6_cksum, &naddr, 0); rewrite++; break; #endif /* INET6 */ } } } else { /* check incoming packet for BINAT/RDR */ if ((rdr = pf_get_translation(PF_IN, ifp, pd->proto, saddr, 0, daddr, 0, &naddr, NULL, af)) != NULL) { PF_ACPY(&baddr, daddr, af); switch (af) { #ifdef INET case AF_INET: pf_change_a(&daddr->v4.s_addr, pd->ip_sum, naddr.v4.s_addr, 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: pf_change_a6(daddr, &pd->hdr.icmp6->icmp6_cksum, &naddr, 0); rewrite++; break; #endif /* INET6 */ } } } r = TAILQ_FIRST(pf_main_ruleset.rules[PF_RULESET_FILTER].active.ptr); while (r != NULL) { r->evaluations++; if (r->ifp != NULL && ((r->ifp != ifp && !r->ifnot) || (r->ifp == ifp && r->ifnot))) r = r->skip[PF_SKIP_IFP].ptr; else if (r->direction && r->direction != direction) r = r->skip[PF_SKIP_DIR].ptr; else if (r->af && r->af != af) r = r->skip[PF_SKIP_AF].ptr; else if (r->proto && r->proto != pd->proto) r = r->skip[PF_SKIP_PROTO].ptr; else if (PF_MISMATCHAW(&r->src.addr, saddr, af, r->src.not)) r = r->skip[PF_SKIP_SRC_ADDR].ptr; else if (PF_MISMATCHAW(&r->dst.addr, daddr, af, r->dst.not)) r = r->skip[PF_SKIP_DST_ADDR].ptr; else if (r->type && r->type != icmptype + 1) r = TAILQ_NEXT(r, entries); else if (r->code && r->code != icmpcode + 1) r = TAILQ_NEXT(r, entries); else if (r->tos && !(r->tos & pd->tos)) r = TAILQ_NEXT(r, entries); else if (r->rule_flag & PFRULE_FRAGMENT) r = TAILQ_NEXT(r, entries); else if (r->anchorname[0] && r->anchor == NULL) r = TAILQ_NEXT(r, entries); else { if (r->anchor == NULL) { *rm = r; rs = (anchorrule == NULL ? r : anchorrule); if ((*rm)->quick) break; r = TAILQ_NEXT(r, entries); } else PF_STEP_INTO_ANCHOR(r, anchorrule, ruleset, PF_RULESET_FILTER); } if (r == NULL && anchorrule != NULL) PF_STEP_OUT_OF_ANCHOR(r, anchorrule, ruleset, PF_RULESET_FILTER); } r = *rm; r->packets++; r->bytes += pd->tot_len; if (rs != r) { rs->packets++; rs->bytes += pd->tot_len; } REASON_SET(&reason, PFRES_MATCH); if (r->log) { #ifdef INET6 if (rewrite) m_copyback(m, off, ICMP_MINLEN, (caddr_t)pd->hdr.icmp6); #endif /* INET6 */ PFLOG_PACKET(ifp, h, m, af, direction, reason, rs); } if (r->action != PF_PASS) return (PF_DROP); if (!state_icmp && (r->keep_state || nat != NULL || rdr != NULL)) { /* create new state */ struct pf_state *s = NULL; if (!r->max_states || r->states < r->max_states) s = pool_get(&pf_state_pl, PR_NOWAIT); if (s == NULL) return (PF_DROP); bzero(s, sizeof(*s)); if (rs != NULL) rs->states++; s->rule.ptr = rs; if (nat != NULL) s->nat_rule = nat; else s->nat_rule = rdr; if (s->nat_rule != NULL) s->nat_rule->states++; s->allow_opts = r->allow_opts; s->log = r->log & 2; s->proto = pd->proto; s->direction = direction; s->af = af; if (direction == PF_OUT) { PF_ACPY(&s->gwy.addr, saddr, af); s->gwy.port = icmpid; PF_ACPY(&s->ext.addr, daddr, af); s->ext.port = icmpid; if (nat != NULL) PF_ACPY(&s->lan.addr, &baddr, af); else PF_ACPY(&s->lan.addr, &s->gwy.addr, af); s->lan.port = icmpid; } else { PF_ACPY(&s->lan.addr, daddr, af); s->lan.port = icmpid; PF_ACPY(&s->ext.addr, saddr, af); s->ext.port = icmpid; if (rdr != NULL) PF_ACPY(&s->gwy.addr, &baddr, af); else PF_ACPY(&s->gwy.addr, &s->lan.addr, af); s->gwy.port = icmpid; } s->src.seqlo = 0; s->src.seqhi = 0; s->src.seqdiff = 0; s->src.max_win = 0; s->src.state = 0; s->dst.seqlo = 0; s->dst.seqhi = 0; s->dst.seqdiff = 0; s->dst.max_win = 0; s->dst.state = 0; s->creation = time.tv_sec; s->expire = s->creation + TIMEOUT(r, PFTM_ICMP_FIRST_PACKET); s->packets = 1; s->bytes = pd->tot_len; if (pf_insert_state(s)) { REASON_SET(&reason, PFRES_MEMORY); pool_put(&pf_state_pl, s); return (PF_DROP); } else *sm = s; } #ifdef INET6 /* copy back packet headers if we performed IPv6 NAT operations */ if (rewrite) m_copyback(m, off, ICMP_MINLEN, (caddr_t)pd->hdr.icmp6); #endif /* INET6 */ return (PF_PASS); } int pf_test_other(struct pf_rule **rm, struct pf_state **sm, int direction, struct ifnet *ifp, struct mbuf *m, void *h, struct pf_pdesc *pd) { struct pf_rule *nat = NULL, *rdr = NULL; struct pf_rule *r, *rs = &pf_default_rule, *anchorrule = NULL; struct pf_ruleset *ruleset = NULL; struct pf_addr *saddr = pd->src, *daddr = pd->dst; struct pf_addr baddr, naddr; sa_family_t af = pd->af; u_short reason; if (direction == PF_OUT) { /* check outgoing packet for BINAT/NAT */ if ((nat = pf_get_translation(PF_OUT, ifp, pd->proto, saddr, 0, daddr, 0, &naddr, NULL, af)) != NULL) { PF_ACPY(&baddr, saddr, af); switch (af) { #ifdef INET case AF_INET: pf_change_a(&saddr->v4.s_addr, pd->ip_sum, naddr.v4.s_addr, 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: PF_ACPY(saddr, &naddr, af); break; #endif /* INET6 */ } } } else { /* check incoming packet for BINAT/RDR */ if ((rdr = pf_get_translation(PF_IN, ifp, pd->proto, saddr, 0, daddr, 0, &naddr, NULL, af)) != NULL) { switch (af) { #ifdef INET case AF_INET: pf_change_a(&daddr->v4.s_addr, pd->ip_sum, naddr.v4.s_addr, 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: PF_ACPY(daddr, &naddr, af); break; #endif /* INET6 */ } } } r = TAILQ_FIRST(pf_main_ruleset.rules[PF_RULESET_FILTER].active.ptr); while (r != NULL) { r->evaluations++; if (r->ifp != NULL && ((r->ifp != ifp && !r->ifnot) || (r->ifp == ifp && r->ifnot))) r = r->skip[PF_SKIP_IFP].ptr; else if (r->direction && r->direction != direction) r = r->skip[PF_SKIP_DIR].ptr; else if (r->af && r->af != af) r = r->skip[PF_SKIP_AF].ptr; else if (r->proto && r->proto != pd->proto) r = r->skip[PF_SKIP_PROTO].ptr; else if (PF_MISMATCHAW(&r->src.addr, pd->src, af, r->src.not)) r = r->skip[PF_SKIP_SRC_ADDR].ptr; else if (PF_MISMATCHAW(&r->dst.addr, pd->dst, af, r->dst.not)) r = r->skip[PF_SKIP_DST_ADDR].ptr; else if (r->tos && !(r->tos & pd->tos)) r = TAILQ_NEXT(r, entries); else if (r->rule_flag & PFRULE_FRAGMENT) r = TAILQ_NEXT(r, entries); else if (r->anchorname[0] && r->anchor == NULL) r = TAILQ_NEXT(r, entries); else { if (r->anchor == NULL) { *rm = r; rs = (anchorrule == NULL ? r : anchorrule); if ((*rm)->quick) break; r = TAILQ_NEXT(r, entries); } else PF_STEP_INTO_ANCHOR(r, anchorrule, ruleset, PF_RULESET_FILTER); } if (r == NULL && anchorrule != NULL) PF_STEP_OUT_OF_ANCHOR(r, anchorrule, ruleset, PF_RULESET_FILTER); } r = *rm; r->packets++; r->bytes += pd->tot_len; if (rs != r) { rs->packets++; rs->bytes += pd->tot_len; } REASON_SET(&reason, PFRES_MATCH); if (r->log) PFLOG_PACKET(ifp, h, m, af, direction, reason, rs); if (r->action != PF_PASS) return (PF_DROP); if (r->keep_state || nat != NULL || rdr != NULL) { /* create new state */ struct pf_state *s = NULL; if (!r->max_states || r->states < r->max_states) s = pool_get(&pf_state_pl, PR_NOWAIT); if (s == NULL) return (PF_DROP); bzero(s, sizeof(*s)); if (rs != NULL) rs->states++; s->rule.ptr = rs; if (nat != NULL) s->nat_rule = nat; else s->nat_rule = rdr; if (s->nat_rule != NULL) s->nat_rule->states++; s->allow_opts = r->allow_opts; s->log = r->log & 2; s->proto = pd->proto; s->direction = direction; s->af = af; if (direction == PF_OUT) { PF_ACPY(&s->gwy.addr, saddr, af); s->gwy.port = 0; PF_ACPY(&s->ext.addr, daddr, af); s->ext.port = 0; if (nat != NULL) PF_ACPY(&s->lan.addr, &baddr, af); else PF_ACPY(&s->lan.addr, &s->gwy.addr, af); s->lan.port = 0; } else { PF_ACPY(&s->lan.addr, daddr, af); s->lan.port = 0; PF_ACPY(&s->ext.addr, saddr, af); s->ext.port = 0; if (rdr != NULL) PF_ACPY(&s->gwy.addr, &baddr, af); else PF_ACPY(&s->gwy.addr, &s->lan.addr, af); s->gwy.port = 0; } s->src.seqlo = 0; s->src.seqhi = 0; s->src.seqdiff = 0; s->src.max_win = 0; s->src.state = PFOTHERS_SINGLE; s->dst.seqlo = 0; s->dst.seqhi = 0; s->dst.seqdiff = 0; s->dst.max_win = 0; s->dst.state = PFOTHERS_NO_TRAFFIC; s->creation = time.tv_sec; s->expire = s->creation + TIMEOUT(r, PFTM_OTHER_FIRST_PACKET); s->packets = 1; s->bytes = pd->tot_len; if (pf_insert_state(s)) { REASON_SET(&reason, PFRES_MEMORY); if (r->log) PFLOG_PACKET(ifp, h, m, af, direction, reason, rs); pool_put(&pf_state_pl, s); return (PF_DROP); } else *sm = s; } return (PF_PASS); } int pf_test_fragment(struct pf_rule **rm, int direction, struct ifnet *ifp, struct mbuf *m, void *h, struct pf_pdesc *pd) { struct pf_rule *r, *rs = &pf_default_rule, *anchorrule = NULL; struct pf_ruleset *ruleset = NULL; sa_family_t af = pd->af; u_short reason; r = TAILQ_FIRST(pf_main_ruleset.rules[PF_RULESET_FILTER].active.ptr); while (r != NULL) { r->evaluations++; if (r->ifp != NULL && ((r->ifp != ifp && !r->ifnot) || (r->ifp == ifp && r->ifnot))) r = r->skip[PF_SKIP_IFP].ptr; else if (r->direction && r->direction != direction) r = r->skip[PF_SKIP_DIR].ptr; else if (r->af && r->af != af) r = r->skip[PF_SKIP_AF].ptr; else if (r->proto && r->proto != pd->proto) r = r->skip[PF_SKIP_PROTO].ptr; else if (PF_MISMATCHAW(&r->src.addr, pd->src, af, r->src.not)) r = r->skip[PF_SKIP_SRC_ADDR].ptr; else if (PF_MISMATCHAW(&r->dst.addr, pd->dst, af, r->dst.not)) r = r->skip[PF_SKIP_DST_ADDR].ptr; else if (r->tos && !(r->tos & pd->tos)) r = TAILQ_NEXT(r, entries); else if (r->src.port_op || r->dst.port_op || r->flagset || r->type || r->code) r = TAILQ_NEXT(r, entries); else if (r->anchorname[0] && r->anchor == NULL) r = TAILQ_NEXT(r, entries); else { if (r->anchor == NULL) { *rm = r; rs = (anchorrule == NULL ? r : anchorrule); if ((*rm)->quick) break; r = TAILQ_NEXT(r, entries); } else PF_STEP_INTO_ANCHOR(r, anchorrule, ruleset, PF_RULESET_FILTER); } if (r == NULL && anchorrule != NULL) PF_STEP_OUT_OF_ANCHOR(r, anchorrule, ruleset, PF_RULESET_FILTER); } r = *rm; r->packets++; r->bytes += pd->tot_len; if (rs != r) { rs->packets++; rs->bytes += pd->tot_len; } REASON_SET(&reason, PFRES_MATCH); if (r->log) PFLOG_PACKET(ifp, h, m, af, direction, reason, rs); if (r->action != PF_PASS) return (PF_DROP); return (PF_PASS); } int pf_test_state_tcp(struct pf_state **state, int direction, struct ifnet *ifp, struct mbuf *m, int ipoff, int off, void *h, struct pf_pdesc *pd) { struct pf_tree_node key; struct tcphdr *th = pd->hdr.tcp; u_int16_t win = ntohs(th->th_win); u_int32_t ack, end, seq; u_int8_t sws, dws; int ackskew; struct pf_state_peer *src, *dst; key.af = pd->af; key.proto = IPPROTO_TCP; PF_ACPY(&key.addr[0], pd->src, key.af); PF_ACPY(&key.addr[1], pd->dst, key.af); key.port[0] = th->th_sport; key.port[1] = th->th_dport; STATE_LOOKUP(); if (direction == (*state)->direction) { src = &(*state)->src; dst = &(*state)->dst; } else { src = &(*state)->dst; dst = &(*state)->src; } if (src->wscale && dst->wscale && !(th->th_flags & TH_SYN)) { sws = src->wscale & PF_WSCALE_MASK; dws = dst->wscale & PF_WSCALE_MASK; } else sws = dws = 0; /* * Sequence tracking algorithm from Guido van Rooij's paper: * http://www.madison-gurkha.com/publications/tcp_filtering/ * tcp_filtering.ps */ seq = ntohl(th->th_seq); if (src->seqlo == 0) { /* First packet from this end. Set its state */ /* Deferred generation of sequence number modulator */ if (dst->seqdiff) { while ((src->seqdiff = arc4random()) == 0) ; ack = ntohl(th->th_ack) - dst->seqdiff; pf_change_a(&th->th_seq, &th->th_sum, htonl(seq + src->seqdiff), 0); pf_change_a(&th->th_ack, &th->th_sum, htonl(ack), 0); } else { ack = ntohl(th->th_ack); } end = seq + pd->p_len; if (th->th_flags & TH_SYN) { end++; src->wscale = pf_get_wscale(m, off, th->th_off, pd->af); } if (th->th_flags & TH_FIN) end++; src->seqlo = seq; if (src->state < TCPS_SYN_SENT) src->state = TCPS_SYN_SENT; /* * May need to slide the window (seqhi may have been set by * the crappy stack check or if we picked up the connection * after establishment) */ if (src->seqhi == 1 || SEQ_GEQ(end + MAX(1, dst->max_win << dws), src->seqhi)) src->seqhi = end + MAX(1, dst->max_win << dws); if (win > src->max_win) src->max_win = win; } else { ack = ntohl(th->th_ack) - dst->seqdiff; if (src->seqdiff) { /* Modulate sequence numbers */ pf_change_a(&th->th_seq, &th->th_sum, htonl(seq + src->seqdiff), 0); pf_change_a(&th->th_ack, &th->th_sum, htonl(ack), 0); } end = seq + pd->p_len; if (th->th_flags & TH_SYN) end++; if (th->th_flags & TH_FIN) end++; } if ((th->th_flags & TH_ACK) == 0) { /* Let it pass through the ack skew check */ ack = dst->seqlo; } else if ((ack == 0 && (th->th_flags & (TH_ACK|TH_RST)) == (TH_ACK|TH_RST)) || /* broken tcp stacks do not set ack */ (dst->state < TCPS_SYN_SENT)) { /* * Many stacks (ours included) will set the ACK number in an * FIN|ACK if the SYN times out -- no sequence to ACK. */ ack = dst->seqlo; } if (seq == end) { /* Ease sequencing restrictions on no data packets */ seq = src->seqlo; end = seq; } ackskew = dst->seqlo - ack; #define MAXACKWINDOW (0xffff + 1500) /* 1500 is an arbitrary fudge factor */ if (SEQ_GEQ(src->seqhi, end) && /* Last octet inside other's window space */ SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)) && /* Retrans: not more than one window back */ (ackskew >= -MAXACKWINDOW) && /* Acking not more than one window back */ (ackskew <= MAXACKWINDOW)) { /* Acking not more than one window forward */ (*state)->packets++; (*state)->bytes += pd->tot_len; /* update max window */ if (src->max_win < win) src->max_win = win; /* synchronize sequencing */ if (SEQ_GT(end, src->seqlo)) src->seqlo = end; /* slide the window of what the other end can send */ if (SEQ_GEQ(ack + (win << sws), dst->seqhi)) dst->seqhi = ack + MAX((win << sws), 1); /* update states */ if (th->th_flags & TH_SYN) if (src->state < TCPS_SYN_SENT) src->state = TCPS_SYN_SENT; if (th->th_flags & TH_FIN) if (src->state < TCPS_CLOSING) src->state = TCPS_CLOSING; if (th->th_flags & TH_ACK) { if (dst->state == TCPS_SYN_SENT) dst->state = TCPS_ESTABLISHED; else if (dst->state == TCPS_CLOSING) dst->state = TCPS_FIN_WAIT_2; } if (th->th_flags & TH_RST) src->state = dst->state = TCPS_TIME_WAIT; /* update expire time */ if (src->state >= TCPS_FIN_WAIT_2 && dst->state >= TCPS_FIN_WAIT_2) (*state)->expire = time.tv_sec + TIMEOUT((*state)->rule.ptr, PFTM_TCP_CLOSED); else if (src->state >= TCPS_FIN_WAIT_2 || dst->state >= TCPS_FIN_WAIT_2) (*state)->expire = time.tv_sec + TIMEOUT((*state)->rule.ptr, PFTM_TCP_FIN_WAIT); else if (src->state < TCPS_ESTABLISHED || dst->state < TCPS_ESTABLISHED) (*state)->expire = time.tv_sec + TIMEOUT((*state)->rule.ptr, PFTM_TCP_OPENING); else if (src->state >= TCPS_CLOSING || dst->state >= TCPS_CLOSING) (*state)->expire = time.tv_sec + TIMEOUT((*state)->rule.ptr, PFTM_TCP_CLOSING); else (*state)->expire = time.tv_sec + TIMEOUT((*state)->rule.ptr, PFTM_TCP_ESTABLISHED); /* Fall through to PASS packet */ } else if ((dst->state < TCPS_SYN_SENT || dst->state >= TCPS_FIN_WAIT_2 || src->state >= TCPS_FIN_WAIT_2) && SEQ_GEQ(src->seqhi + MAXACKWINDOW, end) && /* Within a window forward of the originating packet */ SEQ_GEQ(seq, src->seqlo - MAXACKWINDOW)) { /* Within a window backward of the originating packet */ /* * This currently handles three situations: * 1) Stupid stacks will shotgun SYNs before their peer * replies. * 2) When PF catches an already established stream (the * firewall rebooted, the state table was flushed, routes * changed...) * 3) Packets get funky immediately after the connection * closes (this should catch Solaris spurious ACK|FINs * that web servers like to spew after a close) * * This must be a little more careful than the above code * since packet floods will also be caught here. We don't * update the TTL here to mitigate the damage of a packet * flood and so the same code can handle awkward establishment * and a loosened connection close. * In the establishment case, a correct peer response will * validate the connection, go through the normal state code * and keep updating the state TTL. */ if (pf_status.debug >= PF_DEBUG_MISC) { printf("pf: loose state match: "); pf_print_state(*state); pf_print_flags(th->th_flags); printf(" seq=%u ack=%u len=%u ackskew=%d pkts=%d\n", seq, ack, pd->p_len, ackskew, (*state)->packets); } (*state)->packets++; (*state)->bytes += pd->tot_len; /* update max window */ if (src->max_win < win) src->max_win = win; /* synchronize sequencing */ if (SEQ_GT(end, src->seqlo)) src->seqlo = end; /* slide the window of what the other end can send */ if (SEQ_GEQ(ack + (win << sws), dst->seqhi)) dst->seqhi = ack + MAX((win << sws), 1); /* * Cannot set dst->seqhi here since this could be a shotgunned * SYN and not an already established connection. */ if (th->th_flags & TH_FIN) if (src->state < TCPS_CLOSING) src->state = TCPS_CLOSING; if (th->th_flags & TH_RST) src->state = dst->state = TCPS_TIME_WAIT; /* Fall through to PASS packet */ } else { if ((*state)->dst.state == TCPS_SYN_SENT && (*state)->src.state == TCPS_SYN_SENT) { /* Send RST for state mismatches during handshake */ pf_send_reset(off, th, pd, pd->af, 0, (*state)->rule.ptr); src->seqlo = 0; src->seqhi = 1; src->max_win = 1; } else if (pf_status.debug >= PF_DEBUG_MISC) { printf("pf: BAD state: "); pf_print_state(*state); pf_print_flags(th->th_flags); printf(" seq=%u ack=%u len=%u ackskew=%d pkts=%d " "dir=%s,%s\n", seq, ack, pd->p_len, ackskew, ++(*state)->packets, direction == PF_IN ? "in" : "out", direction == (*state)->direction ? "fwd" : "rev"); printf("pf: State failure on: %c %c %c %c | %c %c\n", SEQ_GEQ(src->seqhi, end) ? ' ' : '1', SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)) ? ' ': '2', (ackskew >= -MAXACKWINDOW) ? ' ' : '3', (ackskew <= MAXACKWINDOW) ? ' ' : '4', SEQ_GEQ(src->seqhi + MAXACKWINDOW, end) ?' ' :'5', SEQ_GEQ(seq, src->seqlo - MAXACKWINDOW) ?' ' :'6'); } return (PF_DROP); } /* Any packets which have gotten here are to be passed */ /* translate source/destination address, if needed */ if (STATE_TRANSLATE(*state)) { if (direction == PF_OUT) pf_change_ap(pd->src, &th->th_sport, pd->ip_sum, &th->th_sum, &(*state)->gwy.addr, (*state)->gwy.port, 0, pd->af); else pf_change_ap(pd->dst, &th->th_dport, pd->ip_sum, &th->th_sum, &(*state)->lan.addr, (*state)->lan.port, 0, pd->af); m_copyback(m, off, sizeof(*th), (caddr_t)th); } else if (src->seqdiff) { /* Copyback sequence modulation */ m_copyback(m, off, sizeof(*th), (caddr_t)th); } (*state)->rule.ptr->packets++; (*state)->rule.ptr->bytes += pd->tot_len; if ((*state)->nat_rule != NULL) { (*state)->nat_rule->packets++; (*state)->nat_rule->bytes += pd->tot_len; } return (PF_PASS); } int pf_test_state_udp(struct pf_state **state, int direction, struct ifnet *ifp, struct mbuf *m, int ipoff, int off, void *h, struct pf_pdesc *pd) { struct pf_state_peer *src, *dst; struct pf_tree_node key; struct udphdr *uh = pd->hdr.udp; key.af = pd->af; key.proto = IPPROTO_UDP; PF_ACPY(&key.addr[0], pd->src, key.af); PF_ACPY(&key.addr[1], pd->dst, key.af); key.port[0] = pd->hdr.udp->uh_sport; key.port[1] = pd->hdr.udp->uh_dport; STATE_LOOKUP(); if (direction == (*state)->direction) { src = &(*state)->src; dst = &(*state)->dst; } else { src = &(*state)->dst; dst = &(*state)->src; } (*state)->packets++; (*state)->bytes += pd->tot_len; /* update states */ if (src->state < PFUDPS_SINGLE) src->state = PFUDPS_SINGLE; if (dst->state == PFUDPS_SINGLE) dst->state = PFUDPS_MULTIPLE; /* update expire time */ if (src->state == PFUDPS_MULTIPLE && dst->state == PFUDPS_MULTIPLE) (*state)->expire = time.tv_sec + TIMEOUT((*state)->rule.ptr, PFTM_UDP_MULTIPLE); else (*state)->expire = time.tv_sec + TIMEOUT((*state)->rule.ptr, PFTM_UDP_SINGLE); /* translate source/destination address, if necessary */ if (STATE_TRANSLATE(*state)) { if (direction == PF_OUT) pf_change_ap(pd->src, &uh->uh_sport, pd->ip_sum, &uh->uh_sum, &(*state)->gwy.addr, (*state)->gwy.port, 1, pd->af); else pf_change_ap(pd->dst, &uh->uh_dport, pd->ip_sum, &uh->uh_sum, &(*state)->lan.addr, (*state)->lan.port, 1, pd->af); m_copyback(m, off, sizeof(*uh), (caddr_t)uh); } (*state)->rule.ptr->packets++; (*state)->rule.ptr->bytes += pd->tot_len; if ((*state)->nat_rule != NULL) { (*state)->nat_rule->packets++; (*state)->nat_rule->bytes += pd->tot_len; } return (PF_PASS); } int pf_test_state_icmp(struct pf_state **state, int direction, struct ifnet *ifp, struct mbuf *m, int ipoff, int off, void *h, struct pf_pdesc *pd) { struct pf_addr *saddr = pd->src, *daddr = pd->dst; u_int16_t icmpid, *icmpsum; u_int8_t icmptype; int state_icmp = 0; switch (pd->proto) { #ifdef INET case IPPROTO_ICMP: icmptype = pd->hdr.icmp->icmp_type; icmpid = pd->hdr.icmp->icmp_id; icmpsum = &pd->hdr.icmp->icmp_cksum; if (icmptype == ICMP_UNREACH || icmptype == ICMP_SOURCEQUENCH || icmptype == ICMP_REDIRECT || icmptype == ICMP_TIMXCEED || icmptype == ICMP_PARAMPROB) state_icmp++; break; #endif /* INET */ #ifdef INET6 case IPPROTO_ICMPV6: icmptype = pd->hdr.icmp6->icmp6_type; icmpid = pd->hdr.icmp6->icmp6_id; icmpsum = &pd->hdr.icmp6->icmp6_cksum; if (icmptype == ICMP6_DST_UNREACH || icmptype == ICMP6_PACKET_TOO_BIG || icmptype == ICMP6_TIME_EXCEEDED || icmptype == ICMP6_PARAM_PROB) state_icmp++; break; #endif /* INET6 */ } if (!state_icmp) { /* * ICMP query/reply message not related to a TCP/UDP packet. * Search for an ICMP state. */ struct pf_tree_node key; key.af = pd->af; key.proto = pd->proto; PF_ACPY(&key.addr[0], saddr, key.af); PF_ACPY(&key.addr[1], daddr, key.af); key.port[0] = icmpid; key.port[1] = icmpid; STATE_LOOKUP(); (*state)->packets++; (*state)->bytes += pd->tot_len; (*state)->expire = time.tv_sec + TIMEOUT((*state)->rule.ptr, PFTM_ICMP_ERROR_REPLY); /* translate source/destination address, if needed */ if (PF_ANEQ(&(*state)->lan.addr, &(*state)->gwy.addr, pd->af)) { if (direction == PF_OUT) { switch (pd->af) { #ifdef INET case AF_INET: pf_change_a(&saddr->v4.s_addr, pd->ip_sum, (*state)->gwy.addr.v4.s_addr, 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: pf_change_a6(saddr, &pd->hdr.icmp6->icmp6_cksum, &(*state)->gwy.addr, 0); m_copyback(m, off, ICMP_MINLEN, (caddr_t)pd->hdr.icmp6); break; #endif /* INET6 */ } } else { switch (pd->af) { #ifdef INET case AF_INET: pf_change_a(&daddr->v4.s_addr, pd->ip_sum, (*state)->lan.addr.v4.s_addr, 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: pf_change_a6(daddr, &pd->hdr.icmp6->icmp6_cksum, &(*state)->lan.addr, 0); m_copyback(m, off, ICMP_MINLEN, (caddr_t)pd->hdr.icmp6); break; #endif /* INET6 */ } } } return (PF_PASS); } else { /* * ICMP error message in response to a TCP/UDP packet. * Extract the inner TCP/UDP header and search for that state. */ struct pf_pdesc pd2; #ifdef INET struct ip h2; #endif /* INET */ #ifdef INET6 struct ip6_hdr h2_6; int terminal = 0; #endif /* INET6 */ int ipoff2; int off2; pd2.af = pd->af; switch (pd->af) { #ifdef INET case AF_INET: /* offset of h2 in mbuf chain */ ipoff2 = off + ICMP_MINLEN; if (!pf_pull_hdr(m, ipoff2, &h2, sizeof(h2), NULL, NULL, pd2.af)) { DPFPRINTF(PF_DEBUG_MISC, ("pf: ICMP error message too short " "(ip)\n")); return (PF_DROP); } /* * ICMP error messages don't refer to non-first * fragments */ if (ntohs(h2.ip_off) & IP_OFFMASK) return (PF_DROP); /* offset of protocol header that follows h2 */ off2 = ipoff2 + (h2.ip_hl << 2); pd2.proto = h2.ip_p; pd2.src = (struct pf_addr *)&h2.ip_src; pd2.dst = (struct pf_addr *)&h2.ip_dst; pd2.ip_sum = &h2.ip_sum; break; #endif /* INET */ #ifdef INET6 case AF_INET6: ipoff2 = off + sizeof(struct icmp6_hdr); if (!pf_pull_hdr(m, ipoff2, &h2_6, sizeof(h2_6), NULL, NULL, pd2.af)) { DPFPRINTF(PF_DEBUG_MISC, ("pf: ICMP error message too short " "(ip6)\n")); return (PF_DROP); } pd2.proto = h2_6.ip6_nxt; pd2.src = (struct pf_addr *)&h2_6.ip6_src; pd2.dst = (struct pf_addr *)&h2_6.ip6_dst; pd2.ip_sum = NULL; off2 = ipoff2 + sizeof(h2_6); do { switch (pd2.proto) { case IPPROTO_FRAGMENT: /* * ICMPv6 error messages for * non-first fragments */ return (PF_DROP); case IPPROTO_AH: case IPPROTO_HOPOPTS: case IPPROTO_ROUTING: case IPPROTO_DSTOPTS: { /* get next header and header length */ struct ip6_ext opt6; if (!pf_pull_hdr(m, off2, &opt6, sizeof(opt6), NULL, NULL, pd2.af)) { DPFPRINTF(PF_DEBUG_MISC, ("pf: ICMPv6 short opt\n")); return (PF_DROP); } if (pd2.proto == IPPROTO_AH) off2 += (opt6.ip6e_len + 2) * 4; else off2 += (opt6.ip6e_len + 1) * 8; pd2.proto = opt6.ip6e_nxt; /* goto the next header */ break; } default: terminal++; break; } } while (!terminal); break; #endif /* INET6 */ } switch (pd2.proto) { case IPPROTO_TCP: { struct tcphdr th; u_int32_t seq; struct pf_tree_node key; struct pf_state_peer *src, *dst; u_int8_t dws; /* * Only the first 8 bytes of the TCP header can be * expected. Don't access any TCP header fields after * th_seq, an ackskew test is not possible. */ if (!pf_pull_hdr(m, off2, &th, 8, NULL, NULL, pd2.af)) { DPFPRINTF(PF_DEBUG_MISC, ("pf: ICMP error message too short " "(tcp)\n")); return (PF_DROP); } key.af = pd2.af; key.proto = IPPROTO_TCP; PF_ACPY(&key.addr[0], pd2.dst, pd2.af); key.port[0] = th.th_dport; PF_ACPY(&key.addr[1], pd2.src, pd2.af); key.port[1] = th.th_sport; STATE_LOOKUP(); if (direction == (*state)->direction) { src = &(*state)->dst; dst = &(*state)->src; } else { src = &(*state)->src; dst = &(*state)->dst; } if (src->wscale && dst->wscale && !(th.th_flags & TH_SYN)) dws = dst->wscale & PF_WSCALE_MASK; else dws = 0; /* Demodulate sequence number */ seq = ntohl(th.th_seq) - src->seqdiff; if (src->seqdiff) pf_change_a(&th.th_seq, &th.th_sum, htonl(seq), 0); if (!SEQ_GEQ(src->seqhi, seq) || !SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws))) { if (pf_status.debug >= PF_DEBUG_MISC) { printf("pf: BAD ICMP state: "); pf_print_state(*state); printf(" seq=%u\n", seq); } return (PF_DROP); } if (STATE_TRANSLATE(*state)) { if (direction == PF_IN) { pf_change_icmp(pd2.src, &th.th_sport, saddr, &(*state)->lan.addr, (*state)->lan.port, NULL, pd2.ip_sum, icmpsum, pd->ip_sum, 0, pd2.af); } else { pf_change_icmp(pd2.dst, &th.th_dport, saddr, &(*state)->gwy.addr, (*state)->gwy.port, NULL, pd2.ip_sum, icmpsum, pd->ip_sum, 0, pd2.af); } switch (pd2.af) { #ifdef INET case AF_INET: m_copyback(m, off, ICMP_MINLEN, (caddr_t)pd->hdr.icmp); m_copyback(m, ipoff2, sizeof(h2), (caddr_t)&h2); break; #endif /* INET */ #ifdef INET6 case AF_INET6: m_copyback(m, off, ICMP_MINLEN, (caddr_t)pd->hdr.icmp6); m_copyback(m, ipoff2, sizeof(h2_6), (caddr_t)&h2_6); break; #endif /* INET6 */ } m_copyback(m, off2, 8, (caddr_t)&th); } else if (src->seqdiff) { m_copyback(m, off2, 8, (caddr_t)&th); } return (PF_PASS); break; } case IPPROTO_UDP: { struct udphdr uh; struct pf_tree_node key; if (!pf_pull_hdr(m, off2, &uh, sizeof(uh), NULL, NULL, pd2.af)) { DPFPRINTF(PF_DEBUG_MISC, ("pf: ICMP error message too short " "(udp)\n")); return (PF_DROP); } key.af = pd2.af; key.proto = IPPROTO_UDP; PF_ACPY(&key.addr[0], pd2.dst, pd2.af); key.port[0] = uh.uh_dport; PF_ACPY(&key.addr[1], pd2.src, pd2.af); key.port[1] = uh.uh_sport; STATE_LOOKUP(); if (STATE_TRANSLATE(*state)) { if (direction == PF_IN) { pf_change_icmp(pd2.src, &uh.uh_sport, daddr, &(*state)->lan.addr, (*state)->lan.port, &uh.uh_sum, pd2.ip_sum, icmpsum, pd->ip_sum, 1, pd2.af); } else { pf_change_icmp(pd2.dst, &uh.uh_dport, saddr, &(*state)->gwy.addr, (*state)->gwy.port, &uh.uh_sum, pd2.ip_sum, icmpsum, pd->ip_sum, 1, pd2.af); } switch (pd2.af) { #ifdef INET case AF_INET: m_copyback(m, off, ICMP_MINLEN, (caddr_t)pd->hdr.icmp); m_copyback(m, ipoff2, sizeof(h2), (caddr_t)&h2); break; #endif /* INET */ #ifdef INET6 case AF_INET6: m_copyback(m, off, ICMP_MINLEN, (caddr_t)pd->hdr.icmp6); m_copyback(m, ipoff2, sizeof(h2_6), (caddr_t)&h2_6); break; #endif /* INET6 */ } m_copyback(m, off2, sizeof(uh), (caddr_t)&uh); } return (PF_PASS); break; } #ifdef INET case IPPROTO_ICMP: { struct icmp iih; struct pf_tree_node key; if (!pf_pull_hdr(m, off2, &iih, ICMP_MINLEN, NULL, NULL, pd2.af)) { DPFPRINTF(PF_DEBUG_MISC, ("pf: ICMP error message too short i" "(icmp)\n")); return (PF_DROP); } key.af = pd2.af; key.proto = IPPROTO_ICMP; PF_ACPY(&key.addr[0], pd2.dst, pd2.af); key.port[0] = iih.icmp_id; PF_ACPY(&key.addr[1], pd2.src, pd2.af); key.port[1] = iih.icmp_id; STATE_LOOKUP(); if (STATE_TRANSLATE(*state)) { if (direction == PF_IN) { pf_change_icmp(pd2.src, &iih.icmp_id, daddr, &(*state)->lan.addr, (*state)->lan.port, NULL, pd2.ip_sum, icmpsum, pd->ip_sum, 0, AF_INET); } else { pf_change_icmp(pd2.dst, &iih.icmp_id, saddr, &(*state)->gwy.addr, (*state)->gwy.port, NULL, pd2.ip_sum, icmpsum, pd->ip_sum, 0, AF_INET); } m_copyback(m, off, ICMP_MINLEN, (caddr_t)pd->hdr.icmp); m_copyback(m, ipoff2, sizeof(h2), (caddr_t)&h2); m_copyback(m, off2, ICMP_MINLEN, (caddr_t)&iih); } return (PF_PASS); break; } #endif /* INET */ #ifdef INET6 case IPPROTO_ICMPV6: { struct icmp6_hdr iih; struct pf_tree_node key; if (!pf_pull_hdr(m, off2, &iih, ICMP_MINLEN, NULL, NULL, pd2.af)) { DPFPRINTF(PF_DEBUG_MISC, ("pf: ICMP error message too short " "(icmp6)\n")); return (PF_DROP); } key.af = pd2.af; key.proto = IPPROTO_ICMPV6; PF_ACPY(&key.addr[0], pd2.dst, pd2.af); key.port[0] = iih.icmp6_id; PF_ACPY(&key.addr[1], pd2.src, pd2.af); key.port[1] = iih.icmp6_id; STATE_LOOKUP(); if (STATE_TRANSLATE(*state)) { if (direction == PF_IN) { pf_change_icmp(pd2.src, &iih.icmp6_id, daddr, &(*state)->lan.addr, (*state)->lan.port, NULL, pd2.ip_sum, icmpsum, pd->ip_sum, 0, AF_INET6); } else { pf_change_icmp(pd2.dst, &iih.icmp6_id, saddr, &(*state)->gwy.addr, (*state)->gwy.port, NULL, pd2.ip_sum, icmpsum, pd->ip_sum, 0, AF_INET6); } m_copyback(m, off, ICMP_MINLEN, (caddr_t)pd->hdr.icmp6); m_copyback(m, ipoff2, sizeof(h2_6), (caddr_t)&h2_6); m_copyback(m, off2, ICMP_MINLEN, (caddr_t)&iih); } return (PF_PASS); break; } #endif /* INET6 */ default: DPFPRINTF(PF_DEBUG_MISC, ("pf: ICMP error message for bad proto\n")); return (PF_DROP); } } } int pf_test_state_other(struct pf_state **state, int direction, struct ifnet *ifp, struct pf_pdesc *pd) { struct pf_state_peer *src, *dst; struct pf_tree_node key; key.af = pd->af; key.proto = pd->proto; PF_ACPY(&key.addr[0], pd->src, key.af); PF_ACPY(&key.addr[1], pd->dst, key.af); key.port[0] = 0; key.port[1] = 0; STATE_LOOKUP(); if (direction == (*state)->direction) { src = &(*state)->src; dst = &(*state)->dst; } else { src = &(*state)->dst; dst = &(*state)->src; } (*state)->packets++; (*state)->bytes += pd->tot_len; /* update states */ if (src->state < PFOTHERS_SINGLE) src->state = PFOTHERS_SINGLE; if (dst->state == PFOTHERS_SINGLE) dst->state = PFOTHERS_MULTIPLE; /* update expire time */ if (src->state == PFOTHERS_MULTIPLE && dst->state == PFOTHERS_MULTIPLE) (*state)->expire = time.tv_sec + TIMEOUT((*state)->rule.ptr, PFTM_OTHER_MULTIPLE); else (*state)->expire = time.tv_sec + TIMEOUT((*state)->rule.ptr, PFTM_OTHER_SINGLE); /* translate source/destination address, if necessary */ if (STATE_TRANSLATE(*state)) { if (direction == PF_OUT) switch (pd->af) { #ifdef INET case AF_INET: pf_change_a(&pd->src->v4.s_addr, pd->ip_sum, (*state)->gwy.addr.v4.s_addr, 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: PF_ACPY(pd->src, &(*state)->gwy.addr, pd->af); break; #endif /* INET6 */ } else switch (pd->af) { #ifdef INET case AF_INET: pf_change_a(&pd->dst->v4.s_addr, pd->ip_sum, (*state)->lan.addr.v4.s_addr, 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: PF_ACPY(pd->dst, &(*state)->lan.addr, pd->af); break; #endif /* INET6 */ } } (*state)->rule.ptr->packets++; (*state)->rule.ptr->bytes += pd->tot_len; if ((*state)->nat_rule != NULL) { (*state)->nat_rule->packets++; (*state)->nat_rule->bytes += pd->tot_len; } return (PF_PASS); } /* * ipoff and off are measured from the start of the mbuf chain. * h must be at "ipoff" on the mbuf chain. */ void * pf_pull_hdr(struct mbuf *m, int off, void *p, int len, u_short *actionp, u_short *reasonp, sa_family_t af) { switch (af) { #ifdef INET case AF_INET: { struct ip *h = mtod(m, struct ip *); u_int16_t fragoff = (h->ip_off & IP_OFFMASK) << 3; if (fragoff) { if (fragoff >= len) ACTION_SET(actionp, PF_PASS); else { ACTION_SET(actionp, PF_DROP); REASON_SET(reasonp, PFRES_FRAG); } return (NULL); } if (m->m_pkthdr.len < off + len || h->ip_len < off + len) { ACTION_SET(actionp, PF_DROP); REASON_SET(reasonp, PFRES_SHORT); return (NULL); } break; } #endif /* INET */ #ifdef INET6 case AF_INET6: { struct ip6_hdr *h = mtod(m, struct ip6_hdr *); if (m->m_pkthdr.len < off + len || (ntohs(h->ip6_plen) + sizeof(struct ip6_hdr)) < (unsigned)(off + len)) { ACTION_SET(actionp, PF_DROP); REASON_SET(reasonp, PFRES_SHORT); return (NULL); } break; } #endif /* INET6 */ } m_copydata(m, off, len, p); return (p); } int pf_routable(struct pf_addr *addr, sa_family_t af) { struct sockaddr_in *dst; struct route ro; int ret = 0; bzero(&ro, sizeof(ro)); dst = satosin(&ro.ro_dst); dst->sin_family = af; dst->sin_len = sizeof(*dst); dst->sin_addr = addr->v4; rtalloc_noclone(&ro, NO_CLONING); if (ro.ro_rt != NULL) { ret = 1; RTFREE(ro.ro_rt); } return (ret); } #ifdef INET void pf_route(struct mbuf **m, struct pf_rule *r, int dir, struct ifnet *oifp, struct pf_state *s) { struct mbuf *m0, *m1; struct route iproute; struct route *ro; struct sockaddr_in *dst; struct ip *ip; struct ifnet *ifp = NULL; struct m_tag *mtag; struct pf_addr naddr; int error = 0; if (m == NULL || *m == NULL || r == NULL || (dir != PF_IN && dir != PF_OUT) || oifp == NULL) panic("pf_route: invalid parameters"); if (r->rt == PF_DUPTO) { m0 = *m; mtag = m_tag_find(m0, PACKET_TAG_PF_ROUTED, NULL); if (mtag == NULL) { mtag = m_tag_get(PACKET_TAG_PF_ROUTED, 0, M_NOWAIT); if (mtag == NULL) goto bad; m_tag_prepend(m0, mtag); } m0 = m_copym2(*m, 0, M_COPYALL, M_NOWAIT); if (m0 == NULL) return; } else { if ((r->rt == PF_REPLYTO) == (r->direction == dir)) return; m0 = *m; } if (m0->m_len < sizeof(struct ip)) panic("pf_route: m0->m_len < sizeof(struct ip)"); ip = mtod(m0, struct ip *); ro = &iproute; bzero((caddr_t)ro, sizeof(*ro)); dst = satosin(&ro->ro_dst); dst->sin_family = AF_INET; dst->sin_len = sizeof(*dst); dst->sin_addr = ip->ip_dst; if (r->rt == PF_FASTROUTE) { rtalloc(ro); if (ro->ro_rt == 0) { ipstat.ips_noroute++; goto bad; } ifp = ro->ro_rt->rt_ifp; ro->ro_rt->rt_use++; if (ro->ro_rt->rt_flags & RTF_GATEWAY) dst = satosin(ro->ro_rt->rt_gateway); } else { if (TAILQ_EMPTY(&r->rpool.list)) panic("pf_route: TAILQ_EMPTY(&r->rpool.list)"); if (s == NULL) { pf_map_addr(AF_INET, &r->rpool, (struct pf_addr *)&ip->ip_src, &naddr, NULL); if (!PF_AZERO(&naddr, AF_INET)) dst->sin_addr.s_addr = naddr.v4.s_addr; ifp = r->rpool.cur->ifp; } else { if (s->rt_ifp == NULL) { pf_map_addr(AF_INET, &r->rpool, (struct pf_addr *)&ip->ip_src, &s->rt_addr, NULL); s->rt_ifp = r->rpool.cur->ifp; } if (!PF_AZERO(&s->rt_addr, AF_INET)) dst->sin_addr.s_addr = s->rt_addr.v4.s_addr; ifp = s->rt_ifp; } } if (ifp == NULL) goto bad; if (oifp != ifp) { mtag = m_tag_find(m0, PACKET_TAG_PF_ROUTED, NULL); if (mtag == NULL) { mtag = m_tag_get(PACKET_TAG_PF_ROUTED, 0, M_NOWAIT); if (mtag == NULL) goto bad; m_tag_prepend(m0, mtag); if (pf_test(PF_OUT, ifp, &m0) != PF_PASS) goto bad; else if (m0 == NULL) goto done; if (m0->m_len < sizeof(struct ip)) panic("pf_route: m0->m_len < " "sizeof(struct ip)"); ip = mtod(m0, struct ip *); } } /* Copied from ip_output. */ if (ip->ip_len <= ifp->if_mtu) { ip->ip_len = htons((u_int16_t)ip->ip_len); ip->ip_off = htons((u_int16_t)ip->ip_off); if ((ifp->if_capabilities & IFCAP_CSUM_IPv4) && ifp->if_bridge == NULL) { m0->m_pkthdr.csum |= M_IPV4_CSUM_OUT; ipstat.ips_outhwcsum++; } else { ip->ip_sum = 0; ip->ip_sum = in_cksum(m0, ip->ip_hl << 2); } /* Update relevant hardware checksum stats for TCP/UDP */ if (m0->m_pkthdr.csum & M_TCPV4_CSUM_OUT) tcpstat.tcps_outhwcsum++; else if (m0->m_pkthdr.csum & M_UDPV4_CSUM_OUT) udpstat.udps_outhwcsum++; error = (*ifp->if_output)(ifp, m0, sintosa(dst), NULL); goto done; } /* * Too large for interface; fragment if possible. * Must be able to put at least 8 bytes per fragment. */ if (ip->ip_off & IP_DF) { ipstat.ips_cantfrag++; if (r->rt != PF_DUPTO) { icmp_error(m0, ICMP_UNREACH, ICMP_UNREACH_NEEDFRAG, 0, ifp); goto done; } else goto bad; } m1 = m0; error = ip_fragment(m0, ifp, ifp->if_mtu); if (error == EMSGSIZE) goto bad; for (m0 = m1; m0; m0 = m1) { m1 = m0->m_nextpkt; m0->m_nextpkt = 0; if (error == 0) error = (*ifp->if_output)(ifp, m0, sintosa(dst), NULL); else m_freem(m0); } if (error == 0) ipstat.ips_fragmented++; done: if (r->rt != PF_DUPTO) *m = NULL; if (ro == &iproute && ro->ro_rt) RTFREE(ro->ro_rt); return; bad: m_freem(m0); goto done; } #endif /* INET */ #ifdef INET6 void pf_route6(struct mbuf **m, struct pf_rule *r, int dir, struct ifnet *oifp, struct pf_state *s) { struct mbuf *m0; struct m_tag *mtag; struct route_in6 ip6route; struct route_in6 *ro; struct sockaddr_in6 *dst; struct ip6_hdr *ip6; struct ifnet *ifp = NULL; struct pf_addr naddr; int error = 0; if (m == NULL || *m == NULL || r == NULL || (dir != PF_IN && dir != PF_OUT) || oifp == NULL) panic("pf_route6: invalid parameters"); if (r->rt == PF_DUPTO) { m0 = *m; mtag = m_tag_find(m0, PACKET_TAG_PF_ROUTED, NULL); if (mtag == NULL) { mtag = m_tag_get(PACKET_TAG_PF_ROUTED, 0, M_NOWAIT); if (mtag == NULL) goto bad; m_tag_prepend(m0, mtag); } m0 = m_copym2(*m, 0, M_COPYALL, M_NOWAIT); if (m0 == NULL) return; } else { if ((r->rt == PF_REPLYTO) == (r->direction == dir)) return; m0 = *m; } if (m0->m_len < sizeof(struct ip6_hdr)) panic("pf_route6: m0->m_len < sizeof(struct ip6_hdr)"); ip6 = mtod(m0, struct ip6_hdr *); ro = &ip6route; bzero((caddr_t)ro, sizeof(*ro)); dst = (struct sockaddr_in6 *)&ro->ro_dst; dst->sin6_family = AF_INET6; dst->sin6_len = sizeof(*dst); dst->sin6_addr = ip6->ip6_dst; /* Cheat. */ if (r->rt == PF_FASTROUTE) { mtag = m_tag_get(PACKET_TAG_PF_GENERATED, 0, M_NOWAIT); if (mtag == NULL) goto bad; m_tag_prepend(m0, mtag); ip6_output(m0, NULL, NULL, NULL, NULL, NULL); return; } if (TAILQ_EMPTY(&r->rpool.list)) panic("pf_route6: TAILQ_EMPTY(&r->rpool.list)"); if (s == NULL) { pf_map_addr(AF_INET6, &r->rpool, (struct pf_addr *)&ip6->ip6_src, &naddr, NULL); if (!PF_AZERO(&naddr, AF_INET6)) PF_ACPY((struct pf_addr *)&dst->sin6_addr, &naddr, AF_INET6); ifp = r->rpool.cur->ifp; } else { if (s->rt_ifp == NULL) { pf_map_addr(AF_INET6, &r->rpool, (struct pf_addr *)&ip6->ip6_src, &s->rt_addr, NULL); s->rt_ifp = r->rpool.cur->ifp; } if (!PF_AZERO(&s->rt_addr, AF_INET6)) PF_ACPY((struct pf_addr *)&dst->sin6_addr, &s->rt_addr, AF_INET6); ifp = s->rt_ifp; } if (ifp == NULL) goto bad; if (oifp != ifp) { mtag = m_tag_find(m0, PACKET_TAG_PF_ROUTED, NULL); if (mtag == NULL) { mtag = m_tag_get(PACKET_TAG_PF_ROUTED, 0, M_NOWAIT); if (mtag == NULL) goto bad; m_tag_prepend(m0, mtag); if (pf_test6(PF_OUT, ifp, &m0) != PF_PASS) goto bad; else if (m0 == NULL) goto done; } } /* * If the packet is too large for the outgoing interface, * send back an icmp6 error. */ if ((u_long)m0->m_pkthdr.len <= ifp->if_mtu) { error = (*ifp->if_output)(ifp, m0, (struct sockaddr *)dst, NULL); } else { in6_ifstat_inc(ifp, ifs6_in_toobig); if (r->rt != PF_DUPTO) icmp6_error(m0, ICMP6_PACKET_TOO_BIG, 0, ifp->if_mtu); else goto bad; } done: if (r->rt != PF_DUPTO) *m = NULL; return; bad: m_freem(m0); goto done; } #endif /* INET6 */ /* * check protocol (tcp/udp/icmp/icmp6) checksum and set mbuf flag * off is the offset where the protocol header starts * len is the total length of protocol header plus payload * returns 0 when the checksum is valid, otherwise returns 1. */ int pf_check_proto_cksum(struct mbuf *m, int off, int len, u_int8_t p, sa_family_t af) { u_int16_t flag_ok, flag_bad; u_int16_t sum; switch (p) { case IPPROTO_TCP: flag_ok = M_TCP_CSUM_IN_OK; flag_bad = M_TCP_CSUM_IN_BAD; break; case IPPROTO_UDP: flag_ok = M_UDP_CSUM_IN_OK; flag_bad = M_UDP_CSUM_IN_BAD; break; case IPPROTO_ICMP: #ifdef INET6 case IPPROTO_ICMPV6: #endif /* INET6 */ flag_ok = flag_bad = 0; break; default: return (1); } if (m->m_pkthdr.csum & flag_ok) return (0); if (m->m_pkthdr.csum & flag_bad) return (1); if (off < sizeof(struct ip) || len < sizeof(struct udphdr)) return (1); if (m->m_pkthdr.len < off + len) return (1); switch (af) { case AF_INET: if (p == IPPROTO_ICMP) { if (m->m_len < off) return (1); m->m_data += off; m->m_len -= off; sum = in_cksum(m, len); m->m_data -= off; m->m_len += off; } else { if (m->m_len < sizeof(struct ip)) return (1); sum = in4_cksum(m, p, off, len); } break; #ifdef INET6 case AF_INET6: if (m->m_len < sizeof(struct ip6_hdr)) return (1); sum = in6_cksum(m, p, off, len); break; #endif /* INET6 */ default: return (1); } if (sum) { m->m_pkthdr.csum |= flag_bad; switch (p) { case IPPROTO_TCP: tcpstat.tcps_rcvbadsum++; break; case IPPROTO_UDP: udpstat.udps_badsum++; break; case IPPROTO_ICMP: icmpstat.icps_checksum++; break; #ifdef INET6 case IPPROTO_ICMPV6: icmp6stat.icp6s_checksum++; break; #endif /* INET6 */ } return (1); } m->m_pkthdr.csum |= flag_ok; return (0); } #ifdef INET int pf_test(int dir, struct ifnet *ifp, struct mbuf **m0) { u_short action, reason = 0, log = 0; struct mbuf *m = *m0; struct ip *h; struct pf_rule *r = &pf_default_rule; struct pf_state *s = NULL; struct pf_pdesc pd; int off; int pqid = 0; if (!pf_status.running || (m_tag_find(m, PACKET_TAG_PF_GENERATED, NULL) != NULL)) return (PF_PASS); #ifdef DIAGNOSTIC if ((m->m_flags & M_PKTHDR) == 0) panic("non-M_PKTHDR is passed to pf_test"); #endif if (m->m_pkthdr.len < (int)sizeof(*h)) { action = PF_DROP; REASON_SET(&reason, PFRES_SHORT); log = 1; goto done; } /* We do IP header normalization and packet reassembly here */ if (pf_normalize_ip(m0, dir, ifp, &reason) != PF_PASS) { ACTION_SET(&action, PF_DROP); goto done; } m = *m0; h = mtod(m, struct ip *); off = h->ip_hl << 2; if (off < (int)sizeof(*h)) { action = PF_DROP; REASON_SET(&reason, PFRES_SHORT); log = 1; goto done; } pd.src = (struct pf_addr *)&h->ip_src; pd.dst = (struct pf_addr *)&h->ip_dst; pd.ip_sum = &h->ip_sum; pd.proto = h->ip_p; pd.af = AF_INET; pd.tos = h->ip_tos; pd.tot_len = h->ip_len; /* handle fragments that didn't get reassembled by normalization */ if (h->ip_off & (IP_MF | IP_OFFMASK)) { action = pf_test_fragment(&r, dir, ifp, m, h, &pd); goto done; } switch (h->ip_p) { case IPPROTO_TCP: { struct tcphdr th; pd.hdr.tcp = &th; if (!pf_pull_hdr(m, off, &th, sizeof(th), &action, &reason, AF_INET)) { log = action != PF_PASS; goto done; } if (dir == PF_IN && pf_check_proto_cksum(m, off, h->ip_len - off, IPPROTO_TCP, AF_INET)) { action = PF_DROP; goto done; } pd.p_len = pd.tot_len - off - (th.th_off << 2); if ((th.th_flags & TH_ACK) && pd.p_len == 0) pqid = 1; action = pf_normalize_tcp(dir, ifp, m, 0, off, h, &pd); if (action == PF_DROP) break; action = pf_test_state_tcp(&s, dir, ifp, m, 0, off, h, &pd); if (action == PF_PASS) { r = s->rule.ptr; log = s->log; } else if (s == NULL) action = pf_test_tcp(&r, &s, dir, ifp, m, 0, off, h, &pd); break; } case IPPROTO_UDP: { struct udphdr uh; pd.hdr.udp = &uh; if (!pf_pull_hdr(m, off, &uh, sizeof(uh), &action, &reason, AF_INET)) { log = action != PF_PASS; goto done; } if (dir == PF_IN && uh.uh_sum && pf_check_proto_cksum(m, off, h->ip_len - off, IPPROTO_UDP, AF_INET)) { action = PF_DROP; goto done; } action = pf_test_state_udp(&s, dir, ifp, m, 0, off, h, &pd); if (action == PF_PASS) { r = s->rule.ptr; log = s->log; } else if (s == NULL) action = pf_test_udp(&r, &s, dir, ifp, m, 0, off, h, &pd); break; } case IPPROTO_ICMP: { struct icmp ih; pd.hdr.icmp = &ih; if (!pf_pull_hdr(m, off, &ih, ICMP_MINLEN, &action, &reason, AF_INET)) { log = action != PF_PASS; goto done; } if (dir == PF_IN && pf_check_proto_cksum(m, off, h->ip_len - off, IPPROTO_ICMP, AF_INET)) { action = PF_DROP; goto done; } action = pf_test_state_icmp(&s, dir, ifp, m, 0, off, h, &pd); if (action == PF_PASS) { r = s->rule.ptr; r->packets++; r->bytes += h->ip_len; log = s->log; } else if (s == NULL) action = pf_test_icmp(&r, &s, dir, ifp, m, 0, off, h, &pd); break; } default: action = pf_test_state_other(&s, dir, ifp, &pd); if (action == PF_PASS) { r = s->rule.ptr; log = s->log; } else if (s == NULL) action = pf_test_other(&r, &s, dir, ifp, m, h, &pd); break; } if (ifp == status_ifp) { pf_status.bcounters[0][dir == PF_OUT] += pd.tot_len; pf_status.pcounters[0][dir == PF_OUT][action]++; } done: if (r->src.addr.type == PF_ADDR_TABLE) pfr_update_stats(r->src.addr.p.tbl, (s == NULL || s->direction == dir) ? pd.src : pd.dst, pd.af, pd.tot_len, dir == PF_OUT, r->action == PF_PASS, r->src.not); if (r->dst.addr.type == PF_ADDR_TABLE) pfr_update_stats(r->dst.addr.p.tbl, (s == NULL || s->direction == dir) ? pd.dst : pd.src, pd.af, pd.tot_len, dir == PF_OUT, r->action == PF_PASS, r->dst.not); if (action != PF_DROP && h->ip_hl > 5 && !((s && s->allow_opts) || r->allow_opts)) { action = PF_DROP; REASON_SET(&reason, PFRES_SHORT); log = 1; DPFPRINTF(PF_DEBUG_MISC, ("pf: dropping packet with ip options\n")); } #ifdef ALTQ if (action != PF_DROP && r->qid) { struct m_tag *mtag; struct altq_tag *atag; mtag = m_tag_get(PACKET_TAG_PF_QID, sizeof(*atag), M_NOWAIT); if (mtag != NULL) { atag = (struct altq_tag *)(mtag + 1); if (pqid || pd.tos == IPTOS_LOWDELAY) atag->qid = r->pqid; else atag->qid = r->qid; /* add hints for ecn */ atag->af = AF_INET; atag->hdr = h; m_tag_prepend(m, mtag); } } #endif if (log) PFLOG_PACKET(ifp, h, m, AF_INET, dir, reason, r); /* pf_route can free the mbuf causing *m0 to become NULL */ if (r->rt) pf_route(m0, r, dir, ifp, s); return (action); } #endif /* INET */ #ifdef INET6 int pf_test6(int dir, struct ifnet *ifp, struct mbuf **m0) { u_short action, reason = 0, log = 0; struct mbuf *m = *m0; struct ip6_hdr *h; struct pf_rule *r = &pf_default_rule; struct pf_state *s = NULL; struct pf_pdesc pd; int off, terminal = 0; if (!pf_status.running || (m_tag_find(m, PACKET_TAG_PF_GENERATED, NULL) != NULL)) return (PF_PASS); #ifdef DIAGNOSTIC if ((m->m_flags & M_PKTHDR) == 0) panic("non-M_PKTHDR is passed to pf_test"); #endif if (m->m_pkthdr.len < (int)sizeof(*h)) { action = PF_DROP; REASON_SET(&reason, PFRES_SHORT); log = 1; goto done; } m = *m0; h = mtod(m, struct ip6_hdr *); pd.src = (struct pf_addr *)&h->ip6_src; pd.dst = (struct pf_addr *)&h->ip6_dst; pd.ip_sum = NULL; pd.af = AF_INET6; pd.tos = 0; pd.tot_len = ntohs(h->ip6_plen) + sizeof(struct ip6_hdr); off = ((caddr_t)h - m->m_data) + sizeof(struct ip6_hdr); pd.proto = h->ip6_nxt; do { switch (pd.proto) { case IPPROTO_FRAGMENT: action = pf_test_fragment(&r, dir, ifp, m, h, &pd); if (action == PF_DROP) REASON_SET(&reason, PFRES_FRAG); goto done; case IPPROTO_AH: case IPPROTO_HOPOPTS: case IPPROTO_ROUTING: case IPPROTO_DSTOPTS: { /* get next header and header length */ struct ip6_ext opt6; if (!pf_pull_hdr(m, off, &opt6, sizeof(opt6), NULL, NULL, pd.af)) { DPFPRINTF(PF_DEBUG_MISC, ("pf: IPv6 short opt\n")); action = PF_DROP; REASON_SET(&reason, PFRES_SHORT); log = 1; goto done; } if (pd.proto == IPPROTO_AH) off += (opt6.ip6e_len + 2) * 4; else off += (opt6.ip6e_len + 1) * 8; pd.proto = opt6.ip6e_nxt; /* goto the next header */ break; } default: terminal++; break; } } while (!terminal); switch (pd.proto) { case IPPROTO_TCP: { struct tcphdr th; pd.hdr.tcp = &th; if (!pf_pull_hdr(m, off, &th, sizeof(th), &action, &reason, AF_INET6)) { log = action != PF_PASS; goto done; } if (dir == PF_IN && pf_check_proto_cksum(m, off, ntohs(h->ip6_plen), IPPROTO_TCP, AF_INET6)) { action = PF_DROP; goto done; } pd.p_len = pd.tot_len - off - (th.th_off << 2); action = pf_normalize_tcp(dir, ifp, m, 0, off, h, &pd); if (action == PF_DROP) break; action = pf_test_state_tcp(&s, dir, ifp, m, 0, off, h, &pd); if (action == PF_PASS) { r = s->rule.ptr; log = s->log; } else if (s == NULL) action = pf_test_tcp(&r, &s, dir, ifp, m, 0, off, h, &pd); break; } case IPPROTO_UDP: { struct udphdr uh; pd.hdr.udp = &uh; if (!pf_pull_hdr(m, off, &uh, sizeof(uh), &action, &reason, AF_INET6)) { log = action != PF_PASS; goto done; } if (dir == PF_IN && uh.uh_sum && pf_check_proto_cksum(m, off, ntohs(h->ip6_plen), IPPROTO_UDP, AF_INET6)) { action = PF_DROP; goto done; } action = pf_test_state_udp(&s, dir, ifp, m, 0, off, h, &pd); if (action == PF_PASS) { r = s->rule.ptr; log = s->log; } else if (s == NULL) action = pf_test_udp(&r, &s, dir, ifp, m, 0, off, h, &pd); break; } case IPPROTO_ICMPV6: { struct icmp6_hdr ih; pd.hdr.icmp6 = &ih; if (!pf_pull_hdr(m, off, &ih, sizeof(ih), &action, &reason, AF_INET6)) { log = action != PF_PASS; goto done; } if (dir == PF_IN && pf_check_proto_cksum(m, off, ntohs(h->ip6_plen), IPPROTO_ICMPV6, AF_INET6)) { action = PF_DROP; goto done; } action = pf_test_state_icmp(&s, dir, ifp, m, 0, off, h, &pd); if (action == PF_PASS) { r = s->rule.ptr; r->packets++; r->bytes += h->ip6_plen; log = s->log; } else if (s == NULL) action = pf_test_icmp(&r, &s, dir, ifp, m, 0, off, h, &pd); break; } default: action = pf_test_other(&r, &s, dir, ifp, m, h, &pd); break; } if (ifp == status_ifp) { pf_status.bcounters[1][dir == PF_OUT] += pd.tot_len; pf_status.pcounters[1][dir == PF_OUT][action]++; } done: if (r->src.addr.type == PF_ADDR_TABLE) pfr_update_stats(r->src.addr.p.tbl, (s == NULL || s->direction == dir) ? pd.src : pd.dst, pd.af, pd.tot_len, dir == PF_OUT, r->action == PF_PASS, r->src.not); if (r->dst.addr.type == PF_ADDR_TABLE) pfr_update_stats(r->dst.addr.p.tbl, (s == NULL || s->direction == dir) ? pd.dst : pd.src, pd.af, pd.tot_len, dir == PF_OUT, r->action == PF_PASS, r->dst.not); /* XXX handle IPv6 options, if not allowed. not implemented. */ #ifdef ALTQ if (action != PF_DROP && r->qid) { struct m_tag *mtag; struct altq_tag *atag; mtag = m_tag_get(PACKET_TAG_PF_QID, sizeof(*atag), M_NOWAIT); if (mtag != NULL) { atag = (struct altq_tag *)(mtag + 1); if (pd.tos == IPTOS_LOWDELAY) atag->qid = r->pqid; else atag->qid = r->qid; /* add hints for ecn */ atag->af = AF_INET6; atag->hdr = h; m_tag_prepend(m, mtag); } } #endif if (log) PFLOG_PACKET(ifp, h, m, AF_INET6, dir, reason, r); /* pf_route6 can free the mbuf causing *m0 to become NULL */ if (r->rt) pf_route6(m0, r, dir, ifp, s); return (action); } #endif /* INET6 */