/* $OpenBSD: pf.c,v 1.243 2002/08/28 15:43:02 pefo 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 #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 "bpfilter.h" #include "pflog.h" #ifdef INET6 #include #include #include #endif /* INET6 */ #define DPFPRINTF(n, x) if (pf_status.debug >= (n)) printf x struct pf_state_tree; /* * Global variables */ struct pf_rulequeue pf_rules[2]; struct pf_rulequeue *pf_rules_active; struct pf_rulequeue *pf_rules_inactive; struct pf_natqueue *pf_nats_active; struct pf_natqueue *pf_nats_inactive; struct pf_binatqueue *pf_binats_active; struct pf_binatqueue *pf_binats_inactive; struct pf_rdrqueue *pf_rdrs_active; struct pf_rdrqueue *pf_rdrs_inactive; struct pf_status pf_status; struct ifnet *status_ifp; u_int32_t ticket_rules_active; u_int32_t ticket_rules_inactive; u_int32_t ticket_nats_active; u_int32_t ticket_nats_inactive; u_int32_t ticket_binats_active; u_int32_t ticket_binats_inactive; u_int32_t ticket_rdrs_active; u_int32_t ticket_rdrs_inactive; /* Timeouts */ int pftm_tcp_first_packet = 120; /* First TCP packet */ int pftm_tcp_opening = 30; /* No response yet */ int pftm_tcp_established = 24*60*60; /* established */ int pftm_tcp_closing = 15 * 60; /* Half closed */ int pftm_tcp_fin_wait = 45; /* Got both FINs */ int pftm_tcp_closed = 90; /* Got a RST */ int pftm_udp_first_packet = 60; /* First UDP packet */ int pftm_udp_single = 30; /* Unidirectional */ int pftm_udp_multiple = 60; /* Bidirectional */ int pftm_icmp_first_packet = 20; /* First ICMP packet */ int pftm_icmp_error_reply = 10; /* Got error response */ int pftm_other_first_packet = 60; /* First packet */ int pftm_other_single = 30; /* Unidirectional */ int pftm_other_multiple = 60; /* Bidirectional */ int pftm_frag = 30; /* Fragment expire */ int pftm_interval = 10; /* expire interval */ struct timeout pf_expire_to; /* expire timeout */ int *pftm_timeouts[PFTM_MAX] = { &pftm_tcp_first_packet, &pftm_tcp_opening, &pftm_tcp_established, &pftm_tcp_closing, &pftm_tcp_fin_wait, &pftm_tcp_closed, &pftm_udp_first_packet, &pftm_udp_single, &pftm_udp_multiple, &pftm_icmp_first_packet, &pftm_icmp_error_reply, &pftm_other_first_packet, &pftm_other_single, &pftm_other_multiple, &pftm_frag, &pftm_interval }; struct pool pf_tree_pl, pf_rule_pl, pf_nat_pl, pf_sport_pl; struct pool pf_rdr_pl, pf_state_pl, pf_binat_pl, pf_addr_pl; void pf_addrcpy(struct pf_addr *, struct pf_addr *, u_int8_t); int pf_compare_rules(struct pf_rule *, struct pf_rule *); int pf_compare_nats(struct pf_nat *, struct pf_nat *); int pf_compare_binats(struct pf_binat *, struct pf_binat *); int pf_compare_rdrs(struct pf_rdr *, struct pf_rdr *); 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 *); 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, int); 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, int); void pf_send_reset(int, struct tcphdr *, struct pf_pdesc *, int, u_int8_t); void pf_send_icmp(struct mbuf *, u_int8_t, u_int8_t, int); u_int16_t pf_map_port_range(struct pf_rdr *, u_int16_t); struct pf_nat *pf_get_nat(struct ifnet *, u_int8_t, struct pf_addr *, u_int16_t, struct pf_addr *, u_int16_t, int); struct pf_binat *pf_get_binat(int, struct ifnet *, u_int8_t, struct pf_addr *, struct pf_addr *, int); struct pf_rdr *pf_get_rdr(struct ifnet *, u_int8_t, struct pf_addr *, struct pf_addr *, u_int16_t, int); int pf_test_tcp(struct pf_rule **, int, struct ifnet *, struct mbuf *, int, int, void *, struct pf_pdesc *); int pf_test_udp(struct pf_rule **, int, struct ifnet *, struct mbuf *, int, int, void *, struct pf_pdesc *); int pf_test_icmp(struct pf_rule **, int, struct ifnet *, struct mbuf *, int, int, void *, struct pf_pdesc *); int pf_test_other(struct pf_rule **, 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 *, int); void pf_calc_skip_steps(struct pf_rulequeue *); int pf_get_sport(u_int8_t, u_int8_t, struct pf_addr *, struct pf_addr *, u_int16_t, 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); void pf_route6(struct mbuf **, struct pf_rule *, int); int pf_socket_lookup(uid_t *, gid_t *, int, int, int, struct pf_pdesc *); struct pf_pool_limit pf_pool_limits[PF_LIMIT_MAX] = { { &pf_state_pl, UINT_MAX }, { &pf_frent_pl, PFFRAG_FRENT_HIWAT } }; #if NPFLOG > 0 #define PFLOG_PACKET(i,x,a,b,c,d,e) \ do { \ if (b == AF_INET) { \ HTONS(((struct ip *)x)->ip_len); \ HTONS(((struct ip *)x)->ip_off); \ pflog_packet(i,a,b,c,d,e); \ NTOHS(((struct ip *)x)->ip_len); \ NTOHS(((struct ip *)x)->ip_off); \ } else { \ pflog_packet(i,a,b,c,d,e); \ } \ } while (0) #else #define PFLOG_PACKET(i,x,a,b,c,d,e) ((void)0) #endif #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) && (r)->timeout[(i)]) ? (r)->timeout[(i)] : *pftm_timeouts[(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); struct pf_rulequeue pf_rules[2]; struct pf_natqueue pf_nats[2]; struct pf_binatqueue pf_binats[2]; struct pf_rdrqueue pf_rdrs[2]; 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, u_int8_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 int pf_compare_rules(struct pf_rule *a, struct pf_rule *b) { if (a->return_icmp != b->return_icmp || a->action != b->action || a->direction != b->direction || a->log != b->log || a->quick != b->quick || a->keep_state != b->keep_state || a->af != b->af || a->proto != b->proto || a->type != b->type || a->code != b->code || a->flags != b->flags || a->flagset != b->flagset || a->rule_flag != b->rule_flag || a->min_ttl != b->min_ttl || a->allow_opts != b->allow_opts) return (1); if (PF_ANEQ(&a->src.addr.addr, &b->src.addr.addr, a->af) || PF_ANEQ(&a->src.mask, &b->src.mask, a->af) || a->src.port[0] != b->src.port[0] || a->src.port[1] != b->src.port[1] || a->src.not != b->src.not || a->src.port_op != b->src.port_op) return (1); if (PF_ANEQ(&a->dst.addr.addr, &b->dst.addr.addr, a->af) || PF_ANEQ(&a->dst.mask, &b->dst.mask, a->af) || a->dst.port[0] != b->dst.port[0] || a->dst.port[1] != b->dst.port[1] || a->dst.not != b->dst.not || a->dst.port_op != b->dst.port_op) return (1); if (strcmp(a->ifname, b->ifname)) return (1); if (a->ifnot != b->ifnot) return (1); return (0); } int pf_compare_nats(struct pf_nat *a, struct pf_nat *b) { if (a->proto != b->proto || a->af != b->af || a->ifnot != b->ifnot || a->no != b->no) return (1); if (PF_ANEQ(&a->src.addr.addr, &b->src.addr.addr, a->af) || PF_ANEQ(&a->src.mask, &b->src.mask, a->af) || a->src.port[0] != b->src.port[0] || a->src.port[1] != b->src.port[1] || a->src.not != b->src.not || a->src.port_op != b->src.port_op) return (1); if (PF_ANEQ(&a->dst.addr.addr, &b->dst.addr.addr, a->af) || PF_ANEQ(&a->dst.mask, &b->dst.mask, a->af) || a->dst.port[0] != b->dst.port[0] || a->dst.port[1] != b->dst.port[1] || a->dst.not != b->dst.not || a->dst.port_op != b->dst.port_op) return (1); if (PF_ANEQ(&a->raddr.addr, &b->raddr.addr, a->af)) return (1); if (strcmp(a->ifname, b->ifname)) return (1); return (0); } int pf_compare_binats(struct pf_binat *a, struct pf_binat *b) { if (a->proto != b->proto || a->dnot != b->dnot || a->af != b->af || a->no != b->no) return (1); if (PF_ANEQ(&a->saddr.addr, &b->saddr.addr, a->af)) return (1); if (PF_ANEQ(&a->daddr.addr, &b->daddr.addr, a->af)) return (1); if (PF_ANEQ(&a->dmask, &b->dmask, a->af)) return (1); if (PF_ANEQ(&a->raddr.addr, &b->raddr.addr, a->af)) return (1); if (strcmp(a->ifname, b->ifname)) return (1); return (0); } int pf_compare_rdrs(struct pf_rdr *a, struct pf_rdr *b) { if (a->dport != b->dport || a->dport2 != b->dport2 || a->rport != b->rport || a->proto != b->proto || a->af != b->af || a->snot != b->snot || a->dnot != b->dnot || a->ifnot != b->ifnot || a->opts != b->opts || a->no != b->no) return (1); if (PF_ANEQ(&a->saddr.addr, &b->saddr.addr, a->af)) return (1); if (PF_ANEQ(&a->smask, &b->smask, a->af)) return (1); if (PF_ANEQ(&a->daddr.addr, &b->daddr.addr, a->af)) return (1); if (PF_ANEQ(&a->dmask, &b->dmask, a->af)) return (1); if (PF_ANEQ(&a->raddr.addr, &b->raddr.addr, a->af)) return (1); if (strcmp(a->ifname, b->ifname)) return (1); return (0); } int pflog_packet(struct ifnet *ifp, struct mbuf *m, int af, u_short dir, u_short reason, struct pf_rule *rm) { #if NBPFILTER > 0 struct ifnet *ifn; struct pfloghdr hdr; struct mbuf m1; if (ifp == NULL || m == NULL || rm == NULL) return (-1); hdr.af = htonl(af); memcpy(hdr.ifname, ifp->if_xname, sizeof(hdr.ifname)); hdr.rnr = htons(rm->nr); hdr.reason = htons(reason); hdr.dir = htons(dir); hdr.action = htons(rm->action); #ifdef INET if (af == AF_INET && dir == PF_OUT) { struct ip *ip; ip = mtod(m, struct ip *); ip->ip_sum = 0; ip->ip_sum = in_cksum(m, ip->ip_hl << 2); } #endif /* INET */ m1.m_next = m; m1.m_len = PFLOG_HDRLEN; m1.m_data = (char *) &hdr; ifn = &(pflogif[0].sc_if); if (ifn->if_bpf) bpf_mtap(ifn->if_bpf, &m1); #endif return (0); } 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++; 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, 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 <= 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 (cur->state->rule.ptr != NULL) cur->state->rule.ptr->states--; 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_dynaddr_setup(struct pf_addr_wrap *aw, u_int8_t af) { if (aw->addr_dyn == NULL) return (0); aw->addr_dyn = pool_get(&pf_addr_pl, PR_NOWAIT); if (aw->addr_dyn == NULL) return (1); bcopy(aw->addr.pfa.ifname, aw->addr_dyn->ifname, sizeof(aw->addr_dyn->ifname)); aw->addr_dyn->ifp = ifunit(aw->addr_dyn->ifname); if (aw->addr_dyn->ifp == NULL) { pool_put(&pf_addr_pl, aw->addr_dyn); aw->addr_dyn = NULL; return (1); } aw->addr_dyn->addr = &aw->addr; aw->addr_dyn->af = af; aw->addr_dyn->undefined = 1; aw->addr_dyn->hook_cookie = hook_establish( aw->addr_dyn->ifp->if_addrhooks, 1, pf_dynaddr_update, aw->addr_dyn); if (aw->addr_dyn->hook_cookie == NULL) { pool_put(&pf_addr_pl, aw->addr_dyn); aw->addr_dyn = NULL; return (1); } pf_dynaddr_update(aw->addr_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->addr_dyn == NULL) return; hook_disestablish(aw->addr_dyn->ifp->if_addrhooks, aw->addr_dyn->hook_cookie); pool_put(&pf_addr_pl, aw->addr_dyn); aw->addr_dyn = NULL; } void pf_dynaddr_copyout(struct pf_addr_wrap *aw) { if (aw->addr_dyn == NULL) return; bcopy(aw->addr_dyn->ifname, aw->addr.pfa.ifname, sizeof(aw->addr.pfa.ifname)); aw->addr_dyn = (struct pf_addr_dyn *)1; } void pf_print_host(struct pf_addr *addr, u_int16_t p, u_int8_t af) { switch(af) { #ifdef INET case AF_INET: { u_int32_t a = ntohl(addr->addr32[0]); p = ntohs(p); printf("%u.%u.%u.%u:%u", (a>>24)&255, (a>>16)&255, (a>>8)&255, a&255, 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(":"); } } 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=%lu high=%lu win=%u modulator=%u]", s->src.seqlo, s->src.seqhi, s->src.max_win, s->src.seqdiff); printf(" [lo=%lu high=%lu win=%u modulator=%u]", s->dst.seqlo, s->dst.seqhi, s->dst.max_win, s->dst.seqdiff); 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_CALC_SKIP_STEP(i, c) \ do { \ if (a & 1 << i) { \ if (c) \ r->skip[i] = TAILQ_NEXT(s, entries); \ else \ a ^= 1 << i; \ } \ } while (0) void pf_calc_skip_steps(struct pf_rulequeue *rules) { struct pf_rule *r, *s; int a, i; r = TAILQ_FIRST(rules); while (r != NULL) { a = 0; for (i = 0; i < PF_SKIP_COUNT; ++i) { a |= 1 << i; r->skip[i] = TAILQ_NEXT(r, entries); } s = TAILQ_NEXT(r, entries); while (a && s != NULL) { PF_CALC_SKIP_STEP(PF_SKIP_ACTION, (s->action == PF_SCRUB && r->action == PF_SCRUB) || (s->action != PF_SCRUB && r->action != PF_SCRUB)); PF_CALC_SKIP_STEP(PF_SKIP_IFP, s->ifp == r->ifp && s->ifnot == r->ifnot); PF_CALC_SKIP_STEP(PF_SKIP_DIR, s->direction == r->direction); PF_CALC_SKIP_STEP(PF_SKIP_AF, s->af == r->af); PF_CALC_SKIP_STEP(PF_SKIP_PROTO, s->proto == r->proto); PF_CALC_SKIP_STEP(PF_SKIP_SRC_ADDR, s->src.addr.addr_dyn == NULL && r->src.addr.addr_dyn == NULL && PF_AEQ(&s->src.addr.addr, &r->src.addr.addr, r->af) && PF_AEQ(&s->src.mask, &r->src.mask, r->af) && s->src.not == r->src.not); PF_CALC_SKIP_STEP(PF_SKIP_SRC_PORT, s->src.port[0] == r->src.port[0] && s->src.port[1] == r->src.port[1] && s->src.port_op == r->src.port_op); PF_CALC_SKIP_STEP(PF_SKIP_DST_ADDR, s->dst.addr.addr_dyn == NULL && r->dst.addr.addr_dyn == NULL && PF_AEQ(&s->dst.addr.addr, &r->dst.addr.addr, r->af) && PF_AEQ(&s->dst.mask, &r->dst.mask, r->af) && s->dst.not == r->dst.not); PF_CALC_SKIP_STEP(PF_SKIP_DST_PORT, s->dst.port[0] == r->dst.port[0] && s->dst.port[1] == r->dst.port[1] && s->dst.port_op == r->dst.port_op); s = TAILQ_NEXT(s, entries); } r = TAILQ_NEXT(r, entries); } } 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, int 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, int af) { struct pf_addr oia, ooa; u_int32_t opc, oh2c = *h2c; 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 checksum and icmp checksum. */ switch (af) { #ifdef INET case AF_INET: *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); 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 */ } *ic = pf_cksum_fixup(*ic, oh2c, *h2c, 0); /* 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, int af, u_int8_t return_ttl) { 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; 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, int af) { 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); 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, int 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_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)); } int pf_get_sport(u_int8_t af, u_int8_t proto, struct pf_addr *daddr, struct pf_addr *raddr, u_int16_t dport, u_int16_t *port, u_int16_t low, u_int16_t high) { struct pf_tree_node key; int step; u_int16_t cut; if (!(proto == IPPROTO_TCP || proto == IPPROTO_UDP)) return (EINVAL); if (low == 0 && high == 0) { NTOHS(*port); return (0); } if (low == high) { *port = low; return (0); } key.af = af; key.proto = proto; PF_ACPY(&key.addr[0], daddr, key.af); PF_ACPY(&key.addr[1], raddr, key.af); key.port[0] = dport; /* port search; start random, step; similar 2 portloop in in_pcbbind */ if (low == high) { key.port[1] = htons(low); if (pf_find_state(&tree_ext_gwy, &key) == NULL) { *port = low; return (0); } return (1); } else if (low < high) { step = 1; cut = arc4random() % (1 + high - low) + low; } else { step = -1; cut = arc4random() % (1 + low - high) + high; } *port = cut - step; do { *port += step; key.port[1] = htons(*port); if (pf_find_state(&tree_ext_gwy, &key) == NULL) return (0); } while (*port != low && *port != high); step = -step; *port = cut; do { *port += step; key.port[1] = htons(*port); if (pf_find_state(&tree_ext_gwy, &key) == NULL) return (0); } while (*port != low && *port != high); return (1); /* none available */ } struct pf_nat * pf_get_nat(struct ifnet *ifp, u_int8_t proto, struct pf_addr *saddr, u_int16_t sport, struct pf_addr *daddr, u_int16_t dport, int af) { struct pf_nat *n, *nm = NULL; n = TAILQ_FIRST(pf_nats_active); while (n && nm == NULL) { if (((n->ifp == NULL) || (n->ifp == ifp && !n->ifnot) || (n->ifp != ifp && n->ifnot)) && (!n->proto || n->proto == proto) && (!n->af || n->af == af) && (n->src.addr.addr_dyn == NULL || !n->src.addr.addr_dyn->undefined) && PF_MATCHA(n->src.not, &n->src.addr.addr, &n->src.mask, saddr, af) && (!n->src.port_op || (proto != IPPROTO_TCP && proto != IPPROTO_UDP) || pf_match_port(n->src.port_op, n->src.port[0], n->src.port[1], sport)) && (n->dst.addr.addr_dyn == NULL || !n->dst.addr.addr_dyn->undefined) && PF_MATCHA(n->dst.not, &n->dst.addr.addr, &n->dst.mask, daddr, af) && (!n->dst.port_op || (proto != IPPROTO_TCP && proto != IPPROTO_UDP) || pf_match_port(n->dst.port_op, n->dst.port[0], n->dst.port[1], dport))) nm = n; else n = TAILQ_NEXT(n, entries); } if (nm && (nm->no || (nm->raddr.addr_dyn != NULL && nm->raddr.addr_dyn->undefined))) return (NULL); return (nm); } struct pf_binat * pf_get_binat(int direction, struct ifnet *ifp, u_int8_t proto, struct pf_addr *saddr, struct pf_addr *daddr, int af) { struct pf_binat *b, *bm = NULL; struct pf_addr fullmask; memset(&fullmask, 0xff, sizeof(fullmask)); b = TAILQ_FIRST(pf_binats_active); while (b && bm == NULL) { if (direction == PF_OUT && b->ifp == ifp && (!b->proto || b->proto == proto) && (!b->af || b->af == af) && (b->saddr.addr_dyn == NULL || !b->saddr.addr_dyn->undefined) && PF_MATCHA(0, &b->saddr.addr, &fullmask, saddr, af) && (b->daddr.addr_dyn == NULL || !b->daddr.addr_dyn->undefined) && PF_MATCHA(b->dnot, &b->daddr.addr, &b->dmask, daddr, af)) bm = b; else if (direction == PF_IN && b->ifp == ifp && (!b->proto || b->proto == proto) && (!b->af || b->af == af) && (b->raddr.addr_dyn == NULL || !b->raddr.addr_dyn->undefined) && PF_MATCHA(0, &b->raddr.addr, &fullmask, saddr, af) && (b->daddr.addr_dyn == NULL || !b->daddr.addr_dyn->undefined) && PF_MATCHA(b->dnot, &b->daddr.addr, &b->dmask, daddr, af)) bm = b; else b = TAILQ_NEXT(b, entries); } if (bm && bm->no) return (NULL); if (bm && direction == PF_OUT && bm->raddr.addr_dyn != NULL && bm->raddr.addr_dyn->undefined) return (NULL); if (bm && direction == PF_IN && bm->saddr.addr_dyn != NULL && bm->saddr.addr_dyn->undefined) return (NULL); return (bm); } struct pf_rdr * pf_get_rdr(struct ifnet *ifp, u_int8_t proto, struct pf_addr *saddr, struct pf_addr *daddr, u_int16_t dport, int af) { struct pf_rdr *r, *rm = NULL; r = TAILQ_FIRST(pf_rdrs_active); while (r && rm == NULL) { if (((r->ifp == NULL) || (r->ifp == ifp && !r->ifnot) || (r->ifp != ifp && r->ifnot)) && (!r->proto || r->proto == proto) && (!r->af || r->af == af) && (r->saddr.addr_dyn == NULL || !r->saddr.addr_dyn->undefined) && PF_MATCHA(r->snot, &r->saddr.addr, &r->smask, saddr, af) && (r->daddr.addr_dyn == NULL || !r->daddr.addr_dyn->undefined) && PF_MATCHA(r->dnot, &r->daddr.addr, &r->dmask, daddr, af) && ((!r->dport2 && (!r->dport || dport == r->dport)) || (r->dport2 && (ntohs(dport) >= ntohs(r->dport)) && ntohs(dport) <= ntohs(r->dport2)))) rm = r; else r = TAILQ_NEXT(r, entries); } if (rm && (rm->no || (rm->raddr.addr_dyn != NULL && rm->raddr.addr_dyn->undefined))) return (NULL); return (rm); } u_int16_t pf_map_port_range(struct pf_rdr *rdr, u_int16_t port) { u_int32_t nport; nport = ntohs(rdr->rport) - ntohs(rdr->dport) + ntohs(port); /* wrap around if necessary */ if (nport > 65535) nport -= 65535; return (htons((u_int16_t)nport)); } int pf_socket_lookup(uid_t *uid, gid_t *gid, int direction, int 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; if (af != AF_INET) return (0); 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; } 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); } *uid = inp->inp_socket->so_euid; *gid = inp->inp_socket->so_egid; return (1); } int pf_test_tcp(struct pf_rule **rm, int direction, struct ifnet *ifp, struct mbuf *m, int ipoff, int off, void *h, struct pf_pdesc *pd) { struct pf_nat *nat = NULL; struct pf_binat *binat = NULL; struct pf_rdr *rdr = NULL; struct pf_addr *saddr = pd->src, *daddr = pd->dst, baddr; struct tcphdr *th = pd->hdr.tcp; u_int16_t bport, nport = 0, af = pd->af; int lookup = -1; uid_t uid; gid_t gid; struct pf_rule *r; u_short reason; int rewrite = 0, error; *rm = NULL; if (direction == PF_OUT) { /* check outgoing packet for BINAT */ if ((binat = pf_get_binat(PF_OUT, ifp, IPPROTO_TCP, saddr, daddr, af)) != NULL) { PF_ACPY(&baddr, saddr, af); bport = th->th_sport; pf_change_ap(saddr, &th->th_sport, pd->ip_sum, &th->th_sum, &binat->raddr.addr, th->th_sport, 0, af); rewrite++; } /* check outgoing packet for NAT */ else if ((nat = pf_get_nat(ifp, IPPROTO_TCP, saddr, th->th_sport, daddr, th->th_dport, af)) != NULL) { bport = nport = th->th_sport; error = pf_get_sport(af, IPPROTO_TCP, daddr, &nat->raddr.addr, th->th_dport, &nport, nat->proxy_port[0], nat->proxy_port[1]); if (error) { DPFPRINTF(PF_DEBUG_MISC, ("pf: NAT proxy port allocation " "(tcp %u-%u) failed\n", nat->proxy_port[0], nat->proxy_port[1])); return (PF_DROP); } PF_ACPY(&baddr, saddr, af); pf_change_ap(saddr, &th->th_sport, pd->ip_sum, &th->th_sum, &nat->raddr.addr, htons(nport), 0, af); rewrite++; } } else { /* check incoming packet for RDR */ if ((rdr = pf_get_rdr(ifp, IPPROTO_TCP, saddr, daddr, th->th_dport, af)) != NULL) { bport = th->th_dport; if (rdr->opts & PF_RPORT_RANGE) nport = pf_map_port_range(rdr, th->th_dport); else if (rdr->rport) nport = rdr->rport; else nport = bport; PF_ACPY(&baddr, daddr, af); pf_change_ap(daddr, &th->th_dport, pd->ip_sum, &th->th_sum, &rdr->raddr.addr, nport, 0, af); rewrite++; } /* check incoming packet for BINAT */ else if ((binat = pf_get_binat(PF_IN, ifp, IPPROTO_TCP, daddr, saddr, af)) != NULL) { PF_ACPY(&baddr, daddr, af); bport = th->th_dport; pf_change_ap(daddr, &th->th_dport, pd->ip_sum, &th->th_sum, &binat->saddr.addr, th->th_dport, 0, af); rewrite++; } } r = TAILQ_FIRST(pf_rules_active); while (r != NULL) { r->evaluations++; if (r->action == PF_SCRUB) r = r->skip[PF_SKIP_ACTION]; else if (r->ifp != NULL && ((r->ifp != ifp && !r->ifnot) || (r->ifp == ifp && r->ifnot))) r = r->skip[PF_SKIP_IFP]; else if (r->direction != direction) r = r->skip[PF_SKIP_DIR]; else if (r->af && r->af != af) r = r->skip[PF_SKIP_AF]; else if (r->proto && r->proto != IPPROTO_TCP) r = r->skip[PF_SKIP_PROTO]; else if (r->src.noroute && pf_routable(saddr, af)) r = TAILQ_NEXT(r, entries); else if (!r->src.noroute && !PF_AZERO(&r->src.mask, af) && !PF_MATCHA(r->src.not, &r->src.addr.addr, &r->src.mask, saddr, af)) r = r->skip[PF_SKIP_SRC_ADDR]; 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]; else if (r->dst.noroute && pf_routable(daddr, af)) r = TAILQ_NEXT(r, entries); else if (!r->dst.noroute && !PF_AZERO(&r->dst.mask, af) && !PF_MATCHA(r->dst.not, &r->dst.addr.addr, &r->dst.mask, daddr, af)) r = r->skip[PF_SKIP_DST_ADDR]; 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]; 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 { *rm = r; if ((*rm)->quick) break; r = TAILQ_NEXT(r, entries); } } if (*rm != NULL) { (*rm)->packets++; (*rm)->bytes += pd->tot_len; REASON_SET(&reason, PFRES_MATCH); if ((*rm)->log) { if (rewrite) m_copyback(m, off, sizeof(*th), (caddr_t)th); PFLOG_PACKET(ifp, h, m, af, direction, reason, *rm); } if (((*rm)->action == PF_DROP) && (((*rm)->rule_flag & PFRULE_RETURNRST) || (*rm)->return_icmp)) { /* undo NAT/RST changes, if they have taken place */ if (nat != NULL || (binat != NULL && direction == PF_OUT)) { pf_change_ap(saddr, &th->th_sport, pd->ip_sum, &th->th_sum, &baddr, bport, 0, af); rewrite++; } else if (rdr != NULL || (binat != NULL && direction == PF_IN)) { pf_change_ap(daddr, &th->th_dport, pd->ip_sum, &th->th_sum, &baddr, bport, 0, af); rewrite++; } if ((*rm)->rule_flag & PFRULE_RETURNRST) pf_send_reset(off, th, pd, af, (*rm)->return_ttl); else pf_send_icmp(m, (*rm)->return_icmp >> 8, (*rm)->return_icmp & 255, af); } if ((*rm)->action == PF_DROP) return (PF_DROP); } if (((*rm != NULL) && (*rm)->keep_state) || nat != NULL || binat != 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 (*rm == NULL || !(*rm)->max_states || (*rm)->states < (*rm)->max_states) s = pool_get(&pf_state_pl, PR_NOWAIT); if (s == NULL) { REASON_SET(&reason, PFRES_MEMORY); return (PF_DROP); } if (*rm != NULL) (*rm)->states++; s->rule.ptr = *rm; s->allow_opts = *rm && (*rm)->allow_opts; s->log = *rm && ((*rm)->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 || binat != 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 (binat != NULL ||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 && *rm != NULL && (*rm)->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++; 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(*rm, 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); } } /* 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, int direction, struct ifnet *ifp, struct mbuf *m, int ipoff, int off, void *h, struct pf_pdesc *pd) { struct pf_nat *nat = NULL; struct pf_binat *binat = NULL; struct pf_rdr *rdr = NULL; struct pf_addr *saddr = pd->src, *daddr = pd->dst, baddr; struct udphdr *uh = pd->hdr.udp; u_int16_t bport, nport = 0, af = pd->af; int lookup = -1; uid_t uid; gid_t gid; struct pf_rule *r; u_short reason; int rewrite = 0, error; *rm = NULL; if (direction == PF_OUT) { /* check outgoing packet for BINAT */ if ((binat = pf_get_binat(PF_OUT, ifp, IPPROTO_UDP, saddr, daddr, af)) != NULL) { PF_ACPY(&baddr, saddr, af); bport = uh->uh_sport; pf_change_ap(saddr, &uh->uh_sport, pd->ip_sum, &uh->uh_sum, &binat->raddr.addr, uh->uh_sport, 1, af); rewrite++; } /* check outgoing packet for NAT */ else if ((nat = pf_get_nat(ifp, IPPROTO_UDP, saddr, uh->uh_sport, daddr, uh->uh_dport, af)) != NULL) { bport = nport = uh->uh_sport; error = pf_get_sport(af, IPPROTO_UDP, daddr, &nat->raddr.addr, uh->uh_dport, &nport, nat->proxy_port[0], nat->proxy_port[1]); if (error) { DPFPRINTF(PF_DEBUG_MISC, ("pf: NAT proxy port allocation " "(udp %u-%u) failed\n", nat->proxy_port[0], nat->proxy_port[1])); return (PF_DROP); } PF_ACPY(&baddr, saddr, af); pf_change_ap(saddr, &uh->uh_sport, pd->ip_sum, &uh->uh_sum, &nat->raddr.addr, htons(nport), 1, af); rewrite++; } } else { /* check incoming packet for RDR */ if ((rdr = pf_get_rdr(ifp, IPPROTO_UDP, saddr, daddr, uh->uh_dport, af)) != NULL) { bport = uh->uh_dport; if (rdr->opts & PF_RPORT_RANGE) nport = pf_map_port_range(rdr, uh->uh_dport); else if (rdr->rport) nport = rdr->rport; else nport = bport; PF_ACPY(&baddr, daddr, af); pf_change_ap(daddr, &uh->uh_dport, pd->ip_sum, &uh->uh_sum, &rdr->raddr.addr, nport, 1, af); rewrite++; } /* check incoming packet for BINAT */ else if ((binat = pf_get_binat(PF_IN, ifp, IPPROTO_UDP, daddr, daddr, af)) != NULL) { PF_ACPY(&baddr, daddr, af); bport = uh->uh_dport; pf_change_ap(daddr, &uh->uh_dport, pd->ip_sum, &uh->uh_sum, &binat->saddr.addr, uh->uh_dport, 1, af); rewrite++; } } r = TAILQ_FIRST(pf_rules_active); while (r != NULL) { r->evaluations++; if (r->action == PF_SCRUB) r = r->skip[PF_SKIP_ACTION]; else if (r->ifp != NULL && ((r->ifp != ifp && !r->ifnot) || (r->ifp == ifp && r->ifnot))) r = r->skip[PF_SKIP_IFP]; else if (r->direction != direction) r = r->skip[PF_SKIP_DIR]; else if (r->af && r->af != af) r = r->skip[PF_SKIP_AF]; else if (r->proto && r->proto != IPPROTO_UDP) r = r->skip[PF_SKIP_PROTO]; else if (r->src.noroute && pf_routable(saddr, af)) r = TAILQ_NEXT(r, entries); else if (!r->src.noroute && !PF_AZERO(&r->src.mask, af) && !PF_MATCHA(r->src.not, &r->src.addr.addr, &r->src.mask, saddr, af)) r = r->skip[PF_SKIP_SRC_ADDR]; 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]; else if (r->dst.noroute && pf_routable(daddr, af)) r = TAILQ_NEXT(r, entries); else if (!r->dst.noroute && !PF_AZERO(&r->dst.mask, af) && !PF_MATCHA(r->dst.not, &r->dst.addr.addr, &r->dst.mask, daddr, af)) r = r->skip[PF_SKIP_DST_ADDR]; 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]; 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 { *rm = r; if ((*rm)->quick) break; r = TAILQ_NEXT(r, entries); } } if (*rm != NULL) { (*rm)->packets++; (*rm)->bytes += pd->tot_len; REASON_SET(&reason, PFRES_MATCH); if ((*rm)->log) { if (rewrite) m_copyback(m, off, sizeof(*uh), (caddr_t)uh); PFLOG_PACKET(ifp, h, m, af, direction, reason, *rm); } if (((*rm)->action == PF_DROP) && (*rm)->return_icmp) { /* undo NAT/RST changes, if they have taken place */ if (nat != NULL || (binat != NULL && direction == PF_OUT)) { pf_change_ap(saddr, &uh->uh_sport, pd->ip_sum, &uh->uh_sum, &baddr, bport, 1, af); rewrite++; } else if (rdr != NULL || (binat != NULL && direction == PF_IN)) { pf_change_ap(daddr, &uh->uh_dport, pd->ip_sum, &uh->uh_sum, &baddr, bport, 1, af); rewrite++; } pf_send_icmp(m, (*rm)->return_icmp >> 8, (*rm)->return_icmp & 255, af); } if ((*rm)->action == PF_DROP) return (PF_DROP); } if ((*rm != NULL && (*rm)->keep_state) || nat != NULL || binat != NULL || rdr != NULL) { /* create new state */ struct pf_state *s = NULL; if (*rm == NULL || !(*rm)->max_states || (*rm)->states < (*rm)->max_states) s = pool_get(&pf_state_pl, PR_NOWAIT); if (s == NULL) return (PF_DROP); if (*rm != NULL) (*rm)->states++; s->rule.ptr = *rm; s->allow_opts = *rm && (*rm)->allow_opts; s->log = *rm && ((*rm)->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 || binat != 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 (binat != NULL || 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(*rm, 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); } } /* 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, int direction, struct ifnet *ifp, struct mbuf *m, int ipoff, int off, void *h, struct pf_pdesc *pd) { struct pf_nat *nat = NULL; struct pf_binat *binat = NULL; struct pf_rdr *rdr = NULL; struct pf_addr *saddr = pd->src, *daddr = pd->dst, baddr; struct pf_rule *r; u_short reason; u_int16_t icmpid, af = pd->af; u_int8_t icmptype, icmpcode; int state_icmp = 0; #ifdef INET6 int rewrite = 0; #endif /* INET6 */ *rm = NULL; 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 */ if ((binat = pf_get_binat(PF_OUT, ifp, IPPROTO_ICMP, saddr, daddr, af)) != NULL) { PF_ACPY(&baddr, saddr, af); switch (af) { #ifdef INET case AF_INET: pf_change_a(&saddr->v4.s_addr, pd->ip_sum, binat->raddr.addr.v4.s_addr, 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: pf_change_a6(saddr, &pd->hdr.icmp6->icmp6_cksum, &binat->raddr.addr, 0); rewrite++; break; #endif /* INET6 */ } } /* check outgoing packet for NAT */ else if ((nat = pf_get_nat(ifp, pd->proto, saddr, 0, daddr, 0, af)) != NULL) { PF_ACPY(&baddr, saddr, af); switch (af) { #ifdef INET case AF_INET: pf_change_a(&saddr->v4.s_addr, pd->ip_sum, nat->raddr.addr.v4.s_addr, 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: pf_change_a6(saddr, &pd->hdr.icmp6->icmp6_cksum, &nat->raddr.addr, 0); rewrite++; break; #endif /* INET6 */ } } } else { /* check incoming packet for RDR */ if ((rdr = pf_get_rdr(ifp, pd->proto, saddr, daddr, 0, af)) != NULL) { PF_ACPY(&baddr, daddr, af); switch (af) { #ifdef INET case AF_INET: pf_change_a(&daddr->v4.s_addr, pd->ip_sum, rdr->raddr.addr.v4.s_addr, 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: pf_change_a6(daddr, &pd->hdr.icmp6->icmp6_cksum, &rdr->raddr.addr, 0); rewrite++; break; #endif /* INET6 */ } } /* check incoming packet for BINAT */ else if ((binat = pf_get_binat(PF_IN, ifp, IPPROTO_ICMP, daddr, saddr, af)) != NULL) { PF_ACPY(&baddr, daddr, af); switch (af) { #ifdef INET case AF_INET: pf_change_a(&daddr->v4.s_addr, pd->ip_sum, binat->saddr.addr.v4.s_addr, 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: pf_change_a6(daddr, &pd->hdr.icmp6->icmp6_cksum, &binat->saddr.addr, 0); rewrite++; break; #endif /* INET6 */ } } } r = TAILQ_FIRST(pf_rules_active); while (r != NULL) { r->evaluations++; if (r->action == PF_SCRUB) r = r->skip[PF_SKIP_ACTION]; else if (r->ifp != NULL && ((r->ifp != ifp && !r->ifnot) || (r->ifp == ifp && r->ifnot))) r = r->skip[PF_SKIP_IFP]; else if (r->direction != direction) r = r->skip[PF_SKIP_DIR]; else if (r->af && r->af != af) r = r->skip[PF_SKIP_AF]; else if (r->proto && r->proto != pd->proto) r = r->skip[PF_SKIP_PROTO]; else if (r->src.noroute && pf_routable(saddr, af)) r = TAILQ_NEXT(r, entries); else if (!r->src.noroute && !PF_AZERO(&r->src.mask, af) && !PF_MATCHA(r->src.not, &r->src.addr.addr, &r->src.mask, saddr, af)) r = r->skip[PF_SKIP_SRC_ADDR]; else if (r->dst.noroute && pf_routable(daddr, af)) r = TAILQ_NEXT(r, entries); else if (!r->dst.noroute && !PF_AZERO(&r->dst.mask, af) && !PF_MATCHA(r->dst.not, &r->dst.addr.addr, &r->dst.mask, daddr, af)) r = r->skip[PF_SKIP_DST_ADDR]; 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->rule_flag & PFRULE_FRAGMENT) r = TAILQ_NEXT(r, entries); else { *rm = r; if ((*rm)->quick) break; r = TAILQ_NEXT(r, entries); } } if (*rm != NULL) { (*rm)->packets++; (*rm)->bytes += pd->tot_len; REASON_SET(&reason, PFRES_MATCH); if ((*rm)->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, *rm); } if ((*rm)->action != PF_PASS) return (PF_DROP); } if (!state_icmp && ((*rm != NULL && (*rm)->keep_state) || nat != NULL || rdr != NULL || binat != NULL)) { /* create new state */ struct pf_state *s = NULL; if (*rm == NULL || !(*rm)->max_states || (*rm)->states < (*rm)->max_states) s = pool_get(&pf_state_pl, PR_NOWAIT); if (s == NULL) return (PF_DROP); if (*rm != NULL) (*rm)->states++; s->rule.ptr = *rm; s->allow_opts = *rm && (*rm)->allow_opts; s->log = *rm && ((*rm)->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 || binat != 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 (binat != NULL || 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(*rm, 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); } } #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, int direction, struct ifnet *ifp, struct mbuf *m, void *h, struct pf_pdesc *pd) { struct pf_rule *r; struct pf_nat *nat = NULL; struct pf_binat *binat = NULL; struct pf_rdr *rdr = NULL; struct pf_addr *saddr = pd->src, *daddr = pd->dst, baddr; u_int8_t af = pd->af; u_short reason; *rm = NULL; if (direction == PF_OUT) { /* check outgoing packet for BINAT */ if ((binat = pf_get_binat(PF_OUT, ifp, pd->proto, saddr, daddr, af)) != NULL) { PF_ACPY(&baddr, saddr, af); switch (af) { #ifdef INET case AF_INET: pf_change_a(&saddr->v4.s_addr, pd->ip_sum, binat->raddr.addr.v4.s_addr, 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: PF_ACPY(saddr, &binat->raddr.addr, af); break; #endif /* INET6 */ } } /* check outgoing packet for NAT */ else if ((nat = pf_get_nat(ifp, pd->proto, saddr, 0, daddr, 0, af)) != NULL) { PF_ACPY(&baddr, saddr, af); switch (af) { #ifdef INET case AF_INET: pf_change_a(&saddr->v4.s_addr, pd->ip_sum, nat->raddr.addr.v4.s_addr, 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: PF_ACPY(saddr, &nat->raddr.addr, af); break; #endif /* INET6 */ } } } else { /* check incoming packet for RDR */ if ((rdr = pf_get_rdr(ifp, pd->proto, saddr, daddr, 0, af)) != NULL) { PF_ACPY(&baddr, daddr, af); switch (af) { #ifdef INET case AF_INET: pf_change_a(&daddr->v4.s_addr, pd->ip_sum, rdr->raddr.addr.v4.s_addr, 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: PF_ACPY(daddr, &rdr->raddr.addr, af); break; #endif /* INET6 */ } } /* check incoming packet for BINAT */ else if ((binat = pf_get_binat(PF_IN, ifp, pd->proto, daddr, saddr, af)) != NULL) { PF_ACPY(&baddr, daddr, af); switch (af) { #ifdef INET case AF_INET: pf_change_a(&daddr->v4.s_addr, pd->ip_sum, binat->saddr.addr.v4.s_addr, 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: PF_ACPY(daddr, &binat->saddr.addr, af); break; #endif /* INET6 */ } } } r = TAILQ_FIRST(pf_rules_active); while (r != NULL) { r->evaluations++; if (r->action == PF_SCRUB) r = r->skip[PF_SKIP_ACTION]; else if (r->ifp != NULL && ((r->ifp != ifp && !r->ifnot) || (r->ifp == ifp && r->ifnot))) r = r->skip[PF_SKIP_IFP]; else if (r->direction != direction) r = r->skip[PF_SKIP_DIR]; else if (r->af && r->af != af) r = r->skip[PF_SKIP_AF]; else if (r->proto && r->proto != pd->proto) r = r->skip[PF_SKIP_PROTO]; else if (r->src.noroute && pf_routable(pd->src, af)) r = TAILQ_NEXT(r, entries); else if (!r->src.noroute && !PF_AZERO(&r->src.mask, af) && !PF_MATCHA(r->src.not, &r->src.addr.addr, &r->src.mask, pd->src, af)) r = r->skip[PF_SKIP_SRC_ADDR]; else if (r->dst.noroute && pf_routable(pd->dst, af)) r = TAILQ_NEXT(r, entries); else if (!r->src.noroute && !PF_AZERO(&r->dst.mask, af) && !PF_MATCHA(r->dst.not, &r->dst.addr.addr, &r->dst.mask, pd->dst, af)) r = r->skip[PF_SKIP_DST_ADDR]; else if (r->rule_flag & PFRULE_FRAGMENT) r = TAILQ_NEXT(r, entries); else { *rm = r; if ((*rm)->quick) break; r = TAILQ_NEXT(r, entries); } } if (*rm != NULL) { (*rm)->packets++; (*rm)->bytes += pd->tot_len; REASON_SET(&reason, PFRES_MATCH); if ((*rm)->log) PFLOG_PACKET(ifp, h, m, af, direction, reason, *rm); if ((*rm)->action != PF_PASS) return (PF_DROP); } if ((*rm != NULL && (*rm)->keep_state) || nat != NULL || rdr != NULL || binat != NULL) { /* create new state */ struct pf_state *s = NULL; if (*rm == NULL || !(*rm)->max_states || (*rm)->states < (*rm)->max_states) s = pool_get(&pf_state_pl, PR_NOWAIT); if (s == NULL) return (PF_DROP); if (*rm != NULL) (*rm)->states++; s->rule.ptr = *rm; s->allow_opts = *rm && (*rm)->allow_opts; s->log = *rm && ((*rm)->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 || binat != 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 (binat != NULL || 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(*rm, PFTM_OTHER_FIRST_PACKET); s->packets = 1; s->bytes = pd->tot_len; if (pf_insert_state(s)) { REASON_SET(&reason, PFRES_MEMORY); if (*rm && (*rm)->log) PFLOG_PACKET(ifp, h, m, af, direction, reason, *rm); pool_put(&pf_state_pl, s); return (PF_DROP); } } 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; u_int8_t af = pd->af; *rm = NULL; r = TAILQ_FIRST(pf_rules_active); while (r != NULL) { r->evaluations++; if (r->action == PF_SCRUB) r = r->skip[PF_SKIP_ACTION]; else if (r->ifp != NULL && ((r->ifp != ifp && !r->ifnot) || (r->ifp == ifp && r->ifnot))) r = r->skip[PF_SKIP_IFP]; else if (r->direction != direction) r = r->skip[PF_SKIP_DIR]; else if (r->af && r->af != af) r = r->skip[PF_SKIP_AF]; else if (r->proto && r->proto != pd->proto) r = r->skip[PF_SKIP_PROTO]; else if (r->src.noroute && pf_routable(pd->src, af)) r = TAILQ_NEXT(r, entries); else if (!r->src.noroute && !PF_AZERO(&r->src.mask, af) && !PF_MATCHA(r->src.not, &r->src.addr.addr, &r->src.mask, pd->src, af)) r = r->skip[PF_SKIP_SRC_ADDR]; else if (r->dst.noroute && pf_routable(pd->dst, af)) r = TAILQ_NEXT(r, entries); else if (!r->src.noroute && !PF_AZERO(&r->dst.mask, af) && !PF_MATCHA(r->dst.not, &r->dst.addr.addr, &r->dst.mask, pd->dst, af)) r = r->skip[PF_SKIP_DST_ADDR]; else if (r->src.port_op || r->dst.port_op || r->flagset || r->type || r->code) r = TAILQ_NEXT(r, entries); else { *rm = r; if ((*rm)->quick) break; r = TAILQ_NEXT(r, entries); } } if (*rm != NULL) { u_short reason; (*rm)->packets++; (*rm)->bytes += pd->tot_len; REASON_SET(&reason, PFRES_MATCH); if ((*rm)->log) PFLOG_PACKET(ifp, h, m, af, direction, reason, *rm); if ((*rm)->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; 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; 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 == (*state)->direction) { src = &(*state)->src; dst = &(*state)->dst; } else { src = &(*state)->dst; dst = &(*state)->src; } /* * 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++; 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), src->seqhi)) src->seqhi = end + MAX(1, dst->max_win); 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) && /* 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, dst->seqhi)) dst->seqhi = ack + MAX(win, 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_CLOSING || dst->state >= TCPS_CLOSING) (*state)->expire = time.tv_sec + TIMEOUT((*state)->rule.ptr, PFTM_TCP_CLOSING); else if (src->state < TCPS_ESTABLISHED || dst->state < TCPS_ESTABLISHED) (*state)->expire = time.tv_sec + TIMEOUT((*state)->rule.ptr, PFTM_TCP_OPENING); 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=%lu ack=%lu 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, dst->seqhi)) dst->seqhi = ack + MAX(win, 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 (pf_status.debug >= PF_DEBUG_MISC) { printf("pf: BAD state: "); pf_print_state(*state); pf_print_flags(th->th_flags); printf(" seq=%lu ack=%lu 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) ? ' ': '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); } if ((*state)->rule.ptr != NULL) { (*state)->rule.ptr->packets++; (*state)->rule.ptr->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; 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 == (*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); } if ((*state)->rule.ptr != NULL) { (*state)->rule.ptr->packets++; (*state)->rule.ptr->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; 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); (*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; /* * 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; 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 == (*state)->direction) { src = &(*state)->dst; dst = &(*state)->src; } else { src = &(*state)->src; dst = &(*state)->dst; } /* 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)) { if (pf_status.debug >= PF_DEBUG_MISC) { printf("pf: BAD ICMP state: "); pf_print_state(*state); printf(" seq=%lu\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; 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 (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 (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; 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 (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; 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 (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; 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 == (*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 */ } } if ((*state)->rule.ptr != NULL) { (*state)->rule.ptr->packets++; (*state)->rule.ptr->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, int 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)) < 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(addr, af) struct pf_addr *addr; int 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 mbuf *m0, *m1; struct route iproute; struct route *ro; struct sockaddr_in *dst; struct ip *ip; struct ifnet *ifp = r->rt_ifp; struct m_tag *mtag; int hlen; int error = 0; if (r->rt == PF_DUPTO) { m0 = m_copym2(*m, 0, M_COPYALL, M_NOWAIT); if (m0 == NULL) return; } else { if (r->direction != dir) return; m0 = *m; } ip = mtod(m0, struct ip *); hlen = ip->ip_hl << 2; 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 (!PF_AZERO(&r->rt_addr, AF_INET)) dst->sin_addr.s_addr = r->rt_addr.v4.s_addr; } if (ifp == NULL) goto bad; if (r->ifp != ifp) { mtag = m_tag_find(m0, PACKET_TAG_PF_ROUTED, NULL); if (mtag == NULL) { if (pf_test(PF_OUT, ifp, &m0) != PF_PASS) goto bad; else if (m0 == NULL) goto done; else { mtag = m_tag_get(PACKET_TAG_PF_ROUTED, 0, M_NOWAIT); if (mtag == NULL) goto bad; m_tag_prepend(m0, mtag); } } } /* Copied from ip_output. */ if ((u_int16_t)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, hlen); } /* 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 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 = r->rt_ifp; int error = 0; if (m == NULL) return; if (r->rt == PF_DUPTO) { m0 = m_copym2(*m, 0, M_COPYALL, M_NOWAIT); if (m0 == NULL) return; } else { if (r->direction != dir) return; m0 = *m; } 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; if (!PF_AZERO(&r->rt_addr, AF_INET6)) dst->sin6_addr = r->rt_addr.v6; /* 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 (ifp == NULL) goto bad; if (r->ifp != ifp) { mtag = m_tag_find(m0, PACKET_TAG_PF_ROUTED, NULL); if (mtag == NULL) { if (pf_test(PF_OUT, ifp, &m0) != PF_PASS) goto bad; else if (m0 == NULL) goto done; else { mtag = m_tag_get(PACKET_TAG_PF_ROUTED, 0, M_NOWAIT); if (mtag == NULL) goto bad; m_tag_prepend(m0, mtag); } } } /* * If the packet is too large for the outgoing interface, * send back an icmp6 error. */ if (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 */ #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 = NULL; struct pf_state *s = NULL; struct pf_pdesc pd; int off; 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 < 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 < 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.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; } 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, 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; } 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, 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; } action = pf_test_state_icmp(&s, dir, ifp, m, 0, off, h, &pd); if (action == PF_PASS) { r = s->rule.ptr; if (r != NULL) { r->packets++; r->bytes += h->ip_len; } log = s->log; } else if (s == NULL) action = pf_test_icmp(&r, 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, dir, ifp, m, h, &pd); break; } if (ifp == status_ifp) { pf_status.bcounters[0][dir] += pd.tot_len; pf_status.pcounters[0][dir][action]++; } done: if (action != PF_DROP && h->ip_hl > 5 && !((s && s->allow_opts) || (r && r->allow_opts))) { action = PF_DROP; REASON_SET(&reason, PFRES_SHORT); log = 1; DPFPRINTF(PF_DEBUG_MISC, ("pf: dropping packet with ip options\n")); } if (log) { if (r == NULL) { struct pf_rule r0; r0.ifp = ifp; r0.action = action; r0.nr = -1; PFLOG_PACKET(ifp, h, m, AF_INET, dir, reason, &r0); } else PFLOG_PACKET(ifp, h, m, AF_INET, dir, reason, r); } /* pf_route can free the mbuf causing *m0 to become NULL */ if (r && r->rt) pf_route(m0, r, dir); 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 = NULL; 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 < 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.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; } 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, 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; } 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, 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; } action = pf_test_state_icmp(&s, dir, ifp, m, 0, off, h, &pd); if (action == PF_PASS) { r = s->rule.ptr; if (r != NULL) { r->packets++; r->bytes += h->ip6_plen; } log = s->log; } else if (s == NULL) action = pf_test_icmp(&r, dir, ifp, m, 0, off, h, &pd); break; } default: action = pf_test_other(&r, dir, ifp, m, h, &pd); break; } if (ifp == status_ifp) { pf_status.bcounters[1][dir] += pd.tot_len; pf_status.pcounters[1][dir][action]++; } done: /* XXX handle IPv6 options, if not allowed. not implemented. */ if (log) { if (r == NULL) { struct pf_rule r0; r0.ifp = ifp; r0.action = action; r0.nr = -1; PFLOG_PACKET(ifp, h, m, AF_INET6, dir, reason, &r0); } else PFLOG_PACKET(ifp, h, m, AF_INET6, dir, reason, r); } /* pf_route6 can free the mbuf causing *m0 to become NULL */ if (r && r->rt) pf_route6(m0, r, dir); return (action); } #endif /* INET6 */