/* $OpenBSD: pf.c,v 1.647 2009/04/30 12:54:32 henning Exp $ */ /* * Copyright (c) 2001 Daniel Hartmeier * Copyright (c) 2002 - 2008 Henning Brauer * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * - Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials provided * with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * * Effort sponsored in part by the Defense Advanced Research Projects * Agency (DARPA) and Air Force Research Laboratory, Air Force * Materiel Command, USAF, under agreement number F30602-01-2-0537. * */ #include "bpfilter.h" #include "pflog.h" #include "pfsync.h" #include "pflow.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if NPFSYNC > 0 #include #endif /* NPFSYNC > 0 */ #ifdef INET6 #include #include #include #include #endif /* INET6 */ #define DPFPRINTF(n, x) if (pf_status.debug >= (n)) printf x /* * Global variables */ /* state tables */ struct pf_state_tree pf_statetbl; struct pf_altqqueue pf_altqs[2]; struct pf_palist pf_pabuf; struct pf_altqqueue *pf_altqs_active; struct pf_altqqueue *pf_altqs_inactive; struct pf_status pf_status; u_int32_t ticket_altqs_active; u_int32_t ticket_altqs_inactive; int altqs_inactive_open; u_int32_t ticket_pabuf; MD5_CTX pf_tcp_secret_ctx; u_char pf_tcp_secret[16]; int pf_tcp_secret_init; int pf_tcp_iss_off; struct pf_anchor_stackframe { struct pf_ruleset *rs; struct pf_rule *r; struct pf_anchor_node *parent; struct pf_anchor *child; } pf_anchor_stack[64]; struct pool pf_src_tree_pl, pf_rule_pl, pf_pooladdr_pl; struct pool pf_state_pl, pf_state_key_pl, pf_state_item_pl; struct pool pf_altq_pl, pf_rule_item_pl; void pf_init_threshold(struct pf_threshold *, u_int32_t, u_int32_t); void pf_add_threshold(struct pf_threshold *); int pf_check_threshold(struct pf_threshold *); void pf_change_ap(struct pf_addr *, u_int16_t *, u_int16_t *, u_int16_t *, struct pf_addr *, u_int16_t, u_int8_t, sa_family_t); int pf_modulate_sack(struct mbuf *, int, struct pf_pdesc *, struct tcphdr *, struct pf_state_peer *); #ifdef INET6 void pf_change_a6(struct pf_addr *, u_int16_t *, struct pf_addr *, u_int8_t); #endif /* INET6 */ int pf_icmp_mapping(struct pf_pdesc *, u_int8_t, int *, int *, u_int16_t *, u_int16_t *); void pf_change_icmp(struct pf_addr *, u_int16_t *, struct pf_addr *, struct pf_addr *, u_int16_t, u_int16_t *, u_int16_t *, u_int16_t *, u_int16_t *, u_int8_t, sa_family_t); void pf_send_tcp(const struct pf_rule *, sa_family_t, const struct pf_addr *, const struct pf_addr *, u_int16_t, u_int16_t, u_int32_t, u_int32_t, u_int8_t, u_int16_t, u_int16_t, u_int8_t, int, u_int16_t, struct ether_header *, struct ifnet *, u_int); void pf_send_icmp(struct mbuf *, u_int8_t, u_int8_t, sa_family_t, struct pf_rule *, u_int); void pf_detach_state(struct pf_state *); void pf_state_key_detach(struct pf_state *, int); u_int32_t pf_tcp_iss(struct pf_pdesc *); void pf_rule_to_actions(struct pf_rule *, struct pf_rule_actions *); int pf_test_rule(struct pf_rule **, struct pf_state **, int, struct pfi_kif *, struct mbuf *, int, void *, struct pf_pdesc *, struct pf_rule **, struct pf_ruleset **, struct ifqueue *); static __inline int pf_create_state(struct pf_rule *, struct pf_rule *, struct pf_rule *, struct pf_pdesc *, struct pf_src_node *, struct pf_state_key *, struct pf_state_key *, struct pf_state_key *, struct pf_state_key *, struct mbuf *, int, u_int16_t, u_int16_t, int *, struct pfi_kif *, struct pf_state **, int, u_int16_t, u_int16_t, int, struct pf_rule_slist *, struct pf_rule_actions *); int pf_test_fragment(struct pf_rule **, int, struct pfi_kif *, struct mbuf *, void *, struct pf_pdesc *, struct pf_rule **, struct pf_ruleset **); int pf_tcp_track_full(struct pf_state_peer *, struct pf_state_peer *, struct pf_state **, struct pfi_kif *, struct mbuf *, int, struct pf_pdesc *, u_short *, int *); int pf_tcp_track_sloppy(struct pf_state_peer *, struct pf_state_peer *, struct pf_state **, struct pf_pdesc *, u_short *); int pf_test_state_tcp(struct pf_state **, int, struct pfi_kif *, struct mbuf *, int, void *, struct pf_pdesc *, u_short *); int pf_test_state_udp(struct pf_state **, int, struct pfi_kif *, struct mbuf *, int, void *, struct pf_pdesc *); int pf_icmp_state_lookup(struct pf_state_key_cmp *, struct pf_pdesc *, struct pf_state **, struct mbuf *, int, struct pfi_kif *, u_int16_t, u_int16_t, int, int *, int); int pf_test_state_icmp(struct pf_state **, int, struct pfi_kif *, struct mbuf *, int, void *, struct pf_pdesc *, u_short *); int pf_test_state_other(struct pf_state **, int, struct pfi_kif *, struct mbuf *, struct pf_pdesc *); void pf_route(struct mbuf **, struct pf_rule *, int, struct ifnet *, struct pf_state *, struct pf_pdesc *); void pf_route6(struct mbuf **, struct pf_rule *, int, struct ifnet *, struct pf_state *, struct pf_pdesc *); int pf_socket_lookup(int, struct pf_pdesc *); u_int8_t pf_get_wscale(struct mbuf *, int, u_int16_t, sa_family_t); u_int16_t pf_get_mss(struct mbuf *, int, u_int16_t, sa_family_t); u_int16_t pf_calc_mss(struct pf_addr *, sa_family_t, u_int16_t); void pf_set_rt_ifp(struct pf_state *, struct pf_addr *); int pf_check_proto_cksum(struct mbuf *, int, int, u_int8_t, sa_family_t); struct pf_divert *pf_get_divert(struct mbuf *); void pf_print_state_parts(struct pf_state *, struct pf_state_key *, struct pf_state_key *); int pf_addr_wrap_neq(struct pf_addr_wrap *, struct pf_addr_wrap *); int pf_compare_state_keys(struct pf_state_key *, struct pf_state_key *, struct pfi_kif *, u_int); struct pf_state *pf_find_state(struct pfi_kif *, struct pf_state_key_cmp *, u_int, struct mbuf *); int pf_src_connlimit(struct pf_state **); int pf_check_congestion(struct ifqueue *); extern struct pool pfr_ktable_pl; extern struct pool pfr_kentry_pl; struct pf_pool_limit pf_pool_limits[PF_LIMIT_MAX] = { { &pf_state_pl, PFSTATE_HIWAT, PFSTATE_HIWAT }, { &pf_src_tree_pl, PFSNODE_HIWAT, PFSNODE_HIWAT }, { &pf_frent_pl, PFFRAG_FRENT_HIWAT, PFFRAG_FRENT_HIWAT }, { &pfr_ktable_pl, PFR_KTABLE_HIWAT, PFR_KTABLE_HIWAT }, { &pfr_kentry_pl, PFR_KENTRY_HIWAT, PFR_KENTRY_HIWAT } }; enum { PF_ICMP_MULTI_NONE, PF_ICMP_MULTI_SOLICITED, PF_ICMP_MULTI_LINK }; #define STATE_LOOKUP(i, k, d, s, m) \ do { \ s = pf_find_state(i, k, d, m); \ if (s == NULL || (s)->timeout == PFTM_PURGE) \ return (PF_DROP); \ if (d == PF_OUT && \ (((s)->rule.ptr->rt == PF_ROUTETO && \ (s)->rule.ptr->direction == PF_OUT) || \ ((s)->rule.ptr->rt == PF_REPLYTO && \ (s)->rule.ptr->direction == PF_IN)) && \ (s)->rt_kif != NULL && \ (s)->rt_kif != i) \ return (PF_PASS); \ } while (0) #define BOUND_IFACE(r, k) \ ((r)->rule_flag & PFRULE_IFBOUND) ? (k) : pfi_all #define STATE_INC_COUNTERS(s) \ do { \ struct pf_rule_item *mrm; \ s->rule.ptr->states_cur++; \ s->rule.ptr->states_tot++; \ if (s->anchor.ptr != NULL) { \ s->anchor.ptr->states_cur++; \ s->anchor.ptr->states_tot++; \ } \ if (s->nat_rule.ptr != NULL) { \ s->nat_rule.ptr->states_cur++; \ s->nat_rule.ptr->states_tot++; \ } \ SLIST_FOREACH(mrm, &s->match_rules, entry) { \ mrm->r->states_cur++; \ mrm->r->states_tot++; \ } \ } while (0) #define STATE_DEC_COUNTERS(s) \ do { \ struct pf_rule_item *mrm; \ if (s->nat_rule.ptr != NULL) \ s->nat_rule.ptr->states_cur--; \ if (s->anchor.ptr != NULL) \ s->anchor.ptr->states_cur--; \ s->rule.ptr->states_cur--; \ SLIST_FOREACH(mrm, &s->match_rules, entry) \ mrm->r->states_cur--; \ } while (0) static __inline int pf_src_compare(struct pf_src_node *, struct pf_src_node *); static __inline int pf_state_compare_key(struct pf_state_key *, struct pf_state_key *); static __inline int pf_state_compare_id(struct pf_state *, struct pf_state *); struct pf_src_tree tree_src_tracking; struct pf_state_tree_id tree_id; struct pf_state_queue state_list; RB_GENERATE(pf_src_tree, pf_src_node, entry, pf_src_compare); RB_GENERATE(pf_state_tree, pf_state_key, entry, pf_state_compare_key); RB_GENERATE(pf_state_tree_id, pf_state, entry_id, pf_state_compare_id); static __inline int pf_src_compare(struct pf_src_node *a, struct pf_src_node *b) { int diff; if (a->rule.ptr > b->rule.ptr) return (1); if (a->rule.ptr < b->rule.ptr) return (-1); if ((diff = a->af - b->af) != 0) return (diff); switch (a->af) { #ifdef INET case AF_INET: if (a->addr.addr32[0] > b->addr.addr32[0]) return (1); if (a->addr.addr32[0] < b->addr.addr32[0]) return (-1); break; #endif /* INET */ #ifdef INET6 case AF_INET6: if (a->addr.addr32[3] > b->addr.addr32[3]) return (1); if (a->addr.addr32[3] < b->addr.addr32[3]) return (-1); if (a->addr.addr32[2] > b->addr.addr32[2]) return (1); if (a->addr.addr32[2] < b->addr.addr32[2]) return (-1); if (a->addr.addr32[1] > b->addr.addr32[1]) return (1); if (a->addr.addr32[1] < b->addr.addr32[1]) return (-1); if (a->addr.addr32[0] > b->addr.addr32[0]) return (1); if (a->addr.addr32[0] < b->addr.addr32[0]) return (-1); break; #endif /* INET6 */ } return (0); } #ifdef INET6 void pf_addrcpy(struct pf_addr *dst, struct pf_addr *src, sa_family_t af) { switch (af) { #ifdef INET case AF_INET: dst->addr32[0] = src->addr32[0]; break; #endif /* INET */ case AF_INET6: dst->addr32[0] = src->addr32[0]; dst->addr32[1] = src->addr32[1]; dst->addr32[2] = src->addr32[2]; dst->addr32[3] = src->addr32[3]; break; } } #endif /* INET6 */ void pf_init_threshold(struct pf_threshold *threshold, u_int32_t limit, u_int32_t seconds) { threshold->limit = limit * PF_THRESHOLD_MULT; threshold->seconds = seconds; threshold->count = 0; threshold->last = time_second; } void pf_add_threshold(struct pf_threshold *threshold) { u_int32_t t = time_second, diff = t - threshold->last; if (diff >= threshold->seconds) threshold->count = 0; else threshold->count -= threshold->count * diff / threshold->seconds; threshold->count += PF_THRESHOLD_MULT; threshold->last = t; } int pf_check_threshold(struct pf_threshold *threshold) { return (threshold->count > threshold->limit); } int pf_src_connlimit(struct pf_state **state) { int bad = 0; (*state)->src_node->conn++; (*state)->src.tcp_est = 1; pf_add_threshold(&(*state)->src_node->conn_rate); if ((*state)->rule.ptr->max_src_conn && (*state)->rule.ptr->max_src_conn < (*state)->src_node->conn) { pf_status.lcounters[LCNT_SRCCONN]++; bad++; } if ((*state)->rule.ptr->max_src_conn_rate.limit && pf_check_threshold(&(*state)->src_node->conn_rate)) { pf_status.lcounters[LCNT_SRCCONNRATE]++; bad++; } if (!bad) return (0); if ((*state)->rule.ptr->overload_tbl) { struct pfr_addr p; u_int32_t killed = 0; pf_status.lcounters[LCNT_OVERLOAD_TABLE]++; if (pf_status.debug >= PF_DEBUG_MISC) { printf("pf_src_connlimit: blocking address "); pf_print_host(&(*state)->src_node->addr, 0, (*state)->key[PF_SK_WIRE]->af); } bzero(&p, sizeof(p)); p.pfra_af = (*state)->key[PF_SK_WIRE]->af; switch ((*state)->key[PF_SK_WIRE]->af) { #ifdef INET case AF_INET: p.pfra_net = 32; p.pfra_ip4addr = (*state)->src_node->addr.v4; break; #endif /* INET */ #ifdef INET6 case AF_INET6: p.pfra_net = 128; p.pfra_ip6addr = (*state)->src_node->addr.v6; break; #endif /* INET6 */ } pfr_insert_kentry((*state)->rule.ptr->overload_tbl, &p, time_second); /* kill existing states if that's required. */ if ((*state)->rule.ptr->flush) { struct pf_state_key *sk; struct pf_state *st; pf_status.lcounters[LCNT_OVERLOAD_FLUSH]++; RB_FOREACH(st, pf_state_tree_id, &tree_id) { sk = st->key[PF_SK_WIRE]; /* * Kill states from this source. (Only those * from the same rule if PF_FLUSH_GLOBAL is not * set) */ if (sk->af == (*state)->key[PF_SK_WIRE]->af && (((*state)->direction == PF_OUT && PF_AEQ(&(*state)->src_node->addr, &sk->addr[0], sk->af)) || ((*state)->direction == PF_IN && PF_AEQ(&(*state)->src_node->addr, &sk->addr[1], sk->af))) && ((*state)->rule.ptr->flush & PF_FLUSH_GLOBAL || (*state)->rule.ptr == st->rule.ptr)) { st->timeout = PFTM_PURGE; st->src.state = st->dst.state = TCPS_CLOSED; killed++; } } if (pf_status.debug >= PF_DEBUG_MISC) printf(", %u states killed", killed); } if (pf_status.debug >= PF_DEBUG_MISC) printf("\n"); } /* kill this state */ (*state)->timeout = PFTM_PURGE; (*state)->src.state = (*state)->dst.state = TCPS_CLOSED; return (1); } int pf_insert_src_node(struct pf_src_node **sn, struct pf_rule *rule, struct pf_addr *src, sa_family_t af) { struct pf_src_node k; if (*sn == NULL) { k.af = af; PF_ACPY(&k.addr, src, af); if (rule->rule_flag & PFRULE_RULESRCTRACK || rule->rpool.opts & PF_POOL_STICKYADDR) k.rule.ptr = rule; else k.rule.ptr = NULL; pf_status.scounters[SCNT_SRC_NODE_SEARCH]++; *sn = RB_FIND(pf_src_tree, &tree_src_tracking, &k); } if (*sn == NULL) { if (!rule->max_src_nodes || rule->src_nodes < rule->max_src_nodes) (*sn) = pool_get(&pf_src_tree_pl, PR_NOWAIT | PR_ZERO); else pf_status.lcounters[LCNT_SRCNODES]++; if ((*sn) == NULL) return (-1); pf_init_threshold(&(*sn)->conn_rate, rule->max_src_conn_rate.limit, rule->max_src_conn_rate.seconds); (*sn)->af = af; if (rule->rule_flag & PFRULE_RULESRCTRACK || rule->rpool.opts & PF_POOL_STICKYADDR) (*sn)->rule.ptr = rule; else (*sn)->rule.ptr = NULL; PF_ACPY(&(*sn)->addr, src, af); if (RB_INSERT(pf_src_tree, &tree_src_tracking, *sn) != NULL) { if (pf_status.debug >= PF_DEBUG_MISC) { printf("pf: src_tree insert failed: "); pf_print_host(&(*sn)->addr, 0, af); printf("\n"); } pool_put(&pf_src_tree_pl, *sn); return (-1); } (*sn)->creation = time_second; (*sn)->ruletype = rule->action; if ((*sn)->rule.ptr != NULL) (*sn)->rule.ptr->src_nodes++; pf_status.scounters[SCNT_SRC_NODE_INSERT]++; pf_status.src_nodes++; } else { if (rule->max_src_states && (*sn)->states >= rule->max_src_states) { pf_status.lcounters[LCNT_SRCSTATES]++; return (-1); } } return (0); } /* state table stuff */ static __inline int pf_state_compare_key(struct pf_state_key *a, struct pf_state_key *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[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[3] > b->addr[1].addr32[3]) return (1); if (a->addr[1].addr32[3] < b->addr[1].addr32[3]) 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[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[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[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[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 /* 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); } static __inline int pf_state_compare_id(struct pf_state *a, struct pf_state *b) { if (a->id > b->id) return (1); if (a->id < b->id) return (-1); if (a->creatorid > b->creatorid) return (1); if (a->creatorid < b->creatorid) return (-1); return (0); } int pf_state_key_attach(struct pf_state_key *sk, struct pf_state *s, int idx) { struct pf_state_item *si; struct pf_state_key *cur; struct pf_state *olds = NULL; KASSERT(s->key[idx] == NULL); /* XXX handle this? */ if ((cur = RB_INSERT(pf_state_tree, &pf_statetbl, sk)) != NULL) { /* key exists. check for same kif, if none, add to key */ TAILQ_FOREACH(si, &cur->states, entry) if (si->s->kif == s->kif && si->s->direction == s->direction) { if (sk->proto == IPPROTO_TCP && si->s->src.state >= TCPS_FIN_WAIT_2 && si->s->dst.state >= TCPS_FIN_WAIT_2) { si->s->src.state = si->s->dst.state = TCPS_CLOSED; /* unlink late or sks can go away */ olds = si->s; } else { if (pf_status.debug >= PF_DEBUG_MISC) { printf("pf: %s key attach " "failed on %s: ", (idx == PF_SK_WIRE) ? "wire" : "stack", s->kif->pfik_name); pf_print_state_parts(s, (idx == PF_SK_WIRE) ? sk : NULL, (idx == PF_SK_STACK) ? sk : NULL); printf(", existing: "); pf_print_state_parts(si->s, (idx == PF_SK_WIRE) ? sk : NULL, (idx == PF_SK_STACK) ? sk : NULL); printf("\n"); } pool_put(&pf_state_key_pl, sk); return (-1); /* collision! */ } } pool_put(&pf_state_key_pl, sk); s->key[idx] = cur; } else s->key[idx] = sk; if ((si = pool_get(&pf_state_item_pl, PR_NOWAIT)) == NULL) { pf_state_key_detach(s, idx); return (-1); } si->s = s; /* list is sorted, if-bound states before floating */ if (s->kif == pfi_all) TAILQ_INSERT_TAIL(&s->key[idx]->states, si, entry); else TAILQ_INSERT_HEAD(&s->key[idx]->states, si, entry); if (olds) pf_unlink_state(olds); return (0); } void pf_detach_state(struct pf_state *s) { if (s->key[PF_SK_WIRE] == s->key[PF_SK_STACK]) s->key[PF_SK_WIRE] = NULL; if (s->key[PF_SK_STACK] != NULL) pf_state_key_detach(s, PF_SK_STACK); if (s->key[PF_SK_WIRE] != NULL) pf_state_key_detach(s, PF_SK_WIRE); } void pf_state_key_detach(struct pf_state *s, int idx) { struct pf_state_item *si; si = TAILQ_FIRST(&s->key[idx]->states); while (si && si->s != s) si = TAILQ_NEXT(si, entry); if (si) { TAILQ_REMOVE(&s->key[idx]->states, si, entry); pool_put(&pf_state_item_pl, si); } if (TAILQ_EMPTY(&s->key[idx]->states)) { RB_REMOVE(pf_state_tree, &pf_statetbl, s->key[idx]); if (s->key[idx]->reverse) s->key[idx]->reverse->reverse = NULL; if (s->key[idx]->inp) s->key[idx]->inp->inp_pf_sk = NULL; pool_put(&pf_state_key_pl, s->key[idx]); } s->key[idx] = NULL; } struct pf_state_key * pf_alloc_state_key(int pool_flags) { struct pf_state_key *sk; if ((sk = pool_get(&pf_state_key_pl, pool_flags)) == NULL) return (NULL); TAILQ_INIT(&sk->states); return (sk); } int pf_state_key_setup(struct pf_pdesc *pd, struct pf_rule *nr, struct pf_state_key **skw, struct pf_state_key **sks, struct pf_state_key **skp, struct pf_state_key **nkp, struct pf_addr *saddr, struct pf_addr *daddr, u_int16_t sport, u_int16_t dport) { KASSERT((*skp == NULL && *nkp == NULL)); if ((*skp = pf_alloc_state_key(PR_NOWAIT | PR_ZERO)) == NULL) return (ENOMEM); PF_ACPY(&(*skp)->addr[pd->sidx], saddr, pd->af); PF_ACPY(&(*skp)->addr[pd->didx], daddr, pd->af); (*skp)->port[pd->sidx] = sport; (*skp)->port[pd->didx] = dport; (*skp)->proto = pd->proto; (*skp)->af = pd->af; if (nr != NULL) { if ((*nkp = pf_alloc_state_key(PR_NOWAIT | PR_ZERO)) == NULL) return (ENOMEM); /* caller must handle cleanup */ /* XXX maybe just bcopy and TAILQ_INIT(&(*nkp)->states) */ PF_ACPY(&(*nkp)->addr[0], &(*skp)->addr[0], pd->af); PF_ACPY(&(*nkp)->addr[1], &(*skp)->addr[1], pd->af); (*nkp)->port[0] = (*skp)->port[0]; (*nkp)->port[1] = (*skp)->port[1]; (*nkp)->proto = pd->proto; (*nkp)->af = pd->af; } else *nkp = *skp; if (pd->dir == PF_IN) { *skw = *skp; *sks = *nkp; } else { *sks = *skp; *skw = *nkp; } return (0); } int pf_state_insert(struct pfi_kif *kif, struct pf_state_key *skw, struct pf_state_key *sks, struct pf_state *s) { splsoftassert(IPL_SOFTNET); s->kif = kif; if (skw == sks) { if (pf_state_key_attach(skw, s, PF_SK_WIRE)) return (-1); s->key[PF_SK_STACK] = s->key[PF_SK_WIRE]; } else { if (pf_state_key_attach(skw, s, PF_SK_WIRE)) { pool_put(&pf_state_key_pl, sks); return (-1); } if (pf_state_key_attach(sks, s, PF_SK_STACK)) { pf_state_key_detach(s, PF_SK_WIRE); return (-1); } } if (s->id == 0 && s->creatorid == 0) { s->id = htobe64(pf_status.stateid++); s->creatorid = pf_status.hostid; } if (RB_INSERT(pf_state_tree_id, &tree_id, s) != NULL) { if (pf_status.debug >= PF_DEBUG_MISC) { printf("pf: state insert failed: " "id: %016llx creatorid: %08x", betoh64(s->id), ntohl(s->creatorid)); printf("\n"); } pf_detach_state(s); return (-1); } TAILQ_INSERT_TAIL(&state_list, s, entry_list); pf_status.fcounters[FCNT_STATE_INSERT]++; pf_status.states++; pfi_kif_ref(kif, PFI_KIF_REF_STATE); #if NPFSYNC > 0 pfsync_insert_state(s); #endif return (0); } struct pf_state * pf_find_state_byid(struct pf_state_cmp *key) { pf_status.fcounters[FCNT_STATE_SEARCH]++; return (RB_FIND(pf_state_tree_id, &tree_id, (struct pf_state *)key)); } /* XXX debug function, intended to be removed one day */ int pf_compare_state_keys(struct pf_state_key *a, struct pf_state_key *b, struct pfi_kif *kif, u_int dir) { /* a (from hdr) and b (new) must be exact opposites of each other */ if (a->af == b->af && a->proto == b->proto && PF_AEQ(&a->addr[0], &b->addr[1], a->af) && PF_AEQ(&a->addr[1], &b->addr[0], a->af) && a->port[0] == b->port[1] && a->port[1] == b->port[0]) return (0); else { /* mismatch. must not happen. */ printf("pf: state key linking mismatch! dir=%s, " "if=%s, stored af=%u, a0: ", dir == PF_OUT ? "OUT" : "IN", kif->pfik_name, a->af); pf_print_host(&a->addr[0], a->port[0], a->af); printf(", a1: "); pf_print_host(&a->addr[1], a->port[1], a->af); printf(", proto=%u", a->proto); printf(", found af=%u, a0: ", b->af); pf_print_host(&b->addr[0], b->port[0], b->af); printf(", a1: "); pf_print_host(&b->addr[1], b->port[1], b->af); printf(", proto=%u", b->proto); printf(".\n"); return (-1); } } struct pf_state * pf_find_state(struct pfi_kif *kif, struct pf_state_key_cmp *key, u_int dir, struct mbuf *m) { struct pf_state_key *sk; struct pf_state_item *si; pf_status.fcounters[FCNT_STATE_SEARCH]++; if (dir == PF_OUT && m->m_pkthdr.pf.statekey && ((struct pf_state_key *)m->m_pkthdr.pf.statekey)->reverse) sk = ((struct pf_state_key *)m->m_pkthdr.pf.statekey)->reverse; else { if ((sk = RB_FIND(pf_state_tree, &pf_statetbl, (struct pf_state_key *)key)) == NULL) return (NULL); if (dir == PF_OUT && m->m_pkthdr.pf.statekey && pf_compare_state_keys(m->m_pkthdr.pf.statekey, sk, kif, dir) == 0) { ((struct pf_state_key *) m->m_pkthdr.pf.statekey)->reverse = sk; sk->reverse = m->m_pkthdr.pf.statekey; } } if (dir == PF_OUT) m->m_pkthdr.pf.statekey = NULL; /* list is sorted, if-bound states before floating ones */ TAILQ_FOREACH(si, &sk->states, entry) if ((si->s->kif == pfi_all || si->s->kif == kif) && sk == (dir == PF_IN ? si->s->key[PF_SK_WIRE] : si->s->key[PF_SK_STACK])) return (si->s); return (NULL); } struct pf_state * pf_find_state_all(struct pf_state_key_cmp *key, u_int dir, int *more) { struct pf_state_key *sk; struct pf_state_item *si, *ret = NULL; pf_status.fcounters[FCNT_STATE_SEARCH]++; sk = RB_FIND(pf_state_tree, &pf_statetbl, (struct pf_state_key *)key); if (sk != NULL) { TAILQ_FOREACH(si, &sk->states, entry) if (dir == PF_INOUT || (sk == (dir == PF_IN ? si->s->key[PF_SK_WIRE] : si->s->key[PF_SK_STACK]))) { if (more == NULL) return (si->s); if (ret) (*more)++; else ret = si; } } return (ret ? ret->s : NULL); } /* END state table stuff */ void pf_purge_thread(void *v) { int nloops = 0, s; for (;;) { tsleep(pf_purge_thread, PWAIT, "pftm", 1 * hz); s = splsoftnet(); /* process a fraction of the state table every second */ pf_purge_expired_states(1 + (pf_status.states / pf_default_rule.timeout[PFTM_INTERVAL])); /* purge other expired types every PFTM_INTERVAL seconds */ if (++nloops >= pf_default_rule.timeout[PFTM_INTERVAL]) { pf_purge_expired_fragments(); pf_purge_expired_src_nodes(0); nloops = 0; } splx(s); } } u_int32_t pf_state_expires(const struct pf_state *state) { u_int32_t timeout; u_int32_t start; u_int32_t end; u_int32_t states; /* handle all PFTM_* > PFTM_MAX here */ if (state->timeout == PFTM_PURGE) return (time_second); if (state->timeout == PFTM_UNTIL_PACKET) return (0); KASSERT(state->timeout != PFTM_UNLINKED); KASSERT(state->timeout < PFTM_MAX); timeout = state->rule.ptr->timeout[state->timeout]; if (!timeout) timeout = pf_default_rule.timeout[state->timeout]; start = state->rule.ptr->timeout[PFTM_ADAPTIVE_START]; if (start) { end = state->rule.ptr->timeout[PFTM_ADAPTIVE_END]; states = state->rule.ptr->states_cur; } else { start = pf_default_rule.timeout[PFTM_ADAPTIVE_START]; end = pf_default_rule.timeout[PFTM_ADAPTIVE_END]; states = pf_status.states; } if (end && states > start && start < end) { if (states < end) return (state->expire + timeout * (end - states) / (end - start)); else return (time_second); } return (state->expire + timeout); } void pf_purge_expired_src_nodes(int waslocked) { struct pf_src_node *cur, *next; int locked = waslocked; for (cur = RB_MIN(pf_src_tree, &tree_src_tracking); cur; cur = next) { next = RB_NEXT(pf_src_tree, &tree_src_tracking, cur); if (cur->states <= 0 && cur->expire <= time_second) { if (! locked) { rw_enter_write(&pf_consistency_lock); next = RB_NEXT(pf_src_tree, &tree_src_tracking, cur); locked = 1; } if (cur->rule.ptr != NULL) { cur->rule.ptr->src_nodes--; if (cur->rule.ptr->states_cur <= 0 && cur->rule.ptr->max_src_nodes <= 0) pf_rm_rule(NULL, cur->rule.ptr); } RB_REMOVE(pf_src_tree, &tree_src_tracking, cur); pf_status.scounters[SCNT_SRC_NODE_REMOVALS]++; pf_status.src_nodes--; pool_put(&pf_src_tree_pl, cur); } } if (locked && !waslocked) rw_exit_write(&pf_consistency_lock); } void pf_src_tree_remove_state(struct pf_state *s) { u_int32_t timeout; if (s->src_node != NULL) { if (s->src.tcp_est) --s->src_node->conn; if (--s->src_node->states <= 0) { timeout = s->rule.ptr->timeout[PFTM_SRC_NODE]; if (!timeout) timeout = pf_default_rule.timeout[PFTM_SRC_NODE]; s->src_node->expire = time_second + timeout; } } if (s->nat_src_node != s->src_node && s->nat_src_node != NULL) { if (--s->nat_src_node->states <= 0) { timeout = s->rule.ptr->timeout[PFTM_SRC_NODE]; if (!timeout) timeout = pf_default_rule.timeout[PFTM_SRC_NODE]; s->nat_src_node->expire = time_second + timeout; } } s->src_node = s->nat_src_node = NULL; } /* callers should be at splsoftnet */ void pf_unlink_state(struct pf_state *cur) { splsoftassert(IPL_SOFTNET); if (cur->src.state == PF_TCPS_PROXY_DST) { /* XXX wire key the right one? */ pf_send_tcp(cur->rule.ptr, cur->key[PF_SK_WIRE]->af, &cur->key[PF_SK_WIRE]->addr[1], &cur->key[PF_SK_WIRE]->addr[0], cur->key[PF_SK_WIRE]->port[1], cur->key[PF_SK_WIRE]->port[0], cur->src.seqhi, cur->src.seqlo + 1, TH_RST|TH_ACK, 0, 0, 0, 1, cur->tag, NULL, NULL, cur->rtableid); } RB_REMOVE(pf_state_tree_id, &tree_id, cur); #if NPFLOW > 0 if (cur->state_flags & PFSTATE_PFLOW) export_pflow(cur); #endif #if NPFSYNC > 0 pfsync_delete_state(cur); #endif cur->timeout = PFTM_UNLINKED; pf_src_tree_remove_state(cur); pf_detach_state(cur); } /* callers should be at splsoftnet and hold the * write_lock on pf_consistency_lock */ void pf_free_state(struct pf_state *cur) { struct pf_rule_item *ri; splsoftassert(IPL_SOFTNET); #if NPFSYNC > 0 if (pfsync_state_in_use(cur)) return; #endif KASSERT(cur->timeout == PFTM_UNLINKED); if (--cur->rule.ptr->states_cur <= 0 && cur->rule.ptr->src_nodes <= 0) pf_rm_rule(NULL, cur->rule.ptr); if (cur->nat_rule.ptr != NULL) if (--cur->nat_rule.ptr->states_cur <= 0 && cur->nat_rule.ptr->src_nodes <= 0) pf_rm_rule(NULL, cur->nat_rule.ptr); if (cur->anchor.ptr != NULL) if (--cur->anchor.ptr->states_cur <= 0) pf_rm_rule(NULL, cur->anchor.ptr); while ((ri = SLIST_FIRST(&cur->match_rules))) { SLIST_REMOVE_HEAD(&cur->match_rules, entry); if (--ri->r->states_cur <= 0 && ri->r->src_nodes <= 0) pf_rm_rule(NULL, ri->r); pool_put(&pf_rule_item_pl, ri); } pf_normalize_tcp_cleanup(cur); pfi_kif_unref(cur->kif, PFI_KIF_REF_STATE); TAILQ_REMOVE(&state_list, cur, entry_list); if (cur->tag) pf_tag_unref(cur->tag); pool_put(&pf_state_pl, cur); pf_status.fcounters[FCNT_STATE_REMOVALS]++; pf_status.states--; } void pf_purge_expired_states(u_int32_t maxcheck) { static struct pf_state *cur = NULL; struct pf_state *next; int locked = 0; while (maxcheck--) { /* wrap to start of list when we hit the end */ if (cur == NULL) { cur = TAILQ_FIRST(&state_list); if (cur == NULL) break; /* list empty */ } /* get next state, as cur may get deleted */ next = TAILQ_NEXT(cur, entry_list); if (cur->timeout == PFTM_UNLINKED) { /* free unlinked state */ if (! locked) { rw_enter_write(&pf_consistency_lock); locked = 1; } pf_free_state(cur); } else if (pf_state_expires(cur) <= time_second) { /* unlink and free expired state */ pf_unlink_state(cur); if (! locked) { rw_enter_write(&pf_consistency_lock); locked = 1; } pf_free_state(cur); } cur = next; } if (locked) rw_exit_write(&pf_consistency_lock); } int pf_tbladdr_setup(struct pf_ruleset *rs, struct pf_addr_wrap *aw) { if (aw->type != PF_ADDR_TABLE) return (0); if ((aw->p.tbl = pfr_attach_table(rs, aw->v.tblname, 1)) == NULL) return (1); return (0); } void pf_tbladdr_remove(struct pf_addr_wrap *aw) { if (aw->type != PF_ADDR_TABLE || aw->p.tbl == NULL) return; pfr_detach_table(aw->p.tbl); aw->p.tbl = NULL; } void pf_tbladdr_copyout(struct pf_addr_wrap *aw) { struct pfr_ktable *kt = aw->p.tbl; if (aw->type != PF_ADDR_TABLE || kt == NULL) return; if (!(kt->pfrkt_flags & PFR_TFLAG_ACTIVE) && kt->pfrkt_root != NULL) kt = kt->pfrkt_root; aw->p.tbl = NULL; aw->p.tblcnt = (kt->pfrkt_flags & PFR_TFLAG_ACTIVE) ? kt->pfrkt_cnt : -1; } void pf_print_host(struct pf_addr *addr, u_int16_t p, sa_family_t af) { switch (af) { #ifdef INET case AF_INET: { u_int32_t a = ntohl(addr->addr32[0]); printf("%u.%u.%u.%u", (a>>24)&255, (a>>16)&255, (a>>8)&255, a&255); if (p) { p = ntohs(p); printf(":%u", p); } break; } #endif /* INET */ #ifdef INET6 case AF_INET6: { u_int16_t b; u_int8_t i, curstart, curend, maxstart, maxend; curstart = curend = maxstart = maxend = 255; for (i = 0; i < 8; i++) { if (!addr->addr16[i]) { if (curstart == 255) curstart = i; curend = i; } else { if ((curend - curstart) > (maxend - maxstart)) { maxstart = curstart; maxend = curend; } curstart = curend = 255; } } if ((curend - curstart) > (maxend - maxstart)) { maxstart = curstart; maxend = curend; } for (i = 0; i < 8; i++) { if (i >= maxstart && i <= maxend) { if (i == 0) printf(":"); if (i == maxend) printf(":"); } else { b = ntohs(addr->addr16[i]); printf("%x", b); if (i < 7) printf(":"); } } if (p) { p = ntohs(p); printf("[%u]", p); } break; } #endif /* INET6 */ } } void pf_print_state(struct pf_state *s) { pf_print_state_parts(s, NULL, NULL); } void pf_print_state_parts(struct pf_state *s, struct pf_state_key *skwp, struct pf_state_key *sksp) { struct pf_state_key *skw, *sks; u_int8_t proto, dir; /* Do our best to fill these, but they're skipped if NULL */ skw = skwp ? skwp : (s ? s->key[PF_SK_WIRE] : NULL); sks = sksp ? sksp : (s ? s->key[PF_SK_STACK] : NULL); proto = skw ? skw->proto : (sks ? sks->proto : 0); dir = s ? s->direction : 0; switch (proto) { case IPPROTO_IPV4: printf("IPv4"); break; case IPPROTO_IPV6: printf("IPv6"); break; 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", skw->proto); break; } switch (dir) { case PF_IN: printf(" in"); break; case PF_OUT: printf(" out"); break; } if (skw) { printf(" wire: "); pf_print_host(&skw->addr[0], skw->port[0], skw->af); printf(" "); pf_print_host(&skw->addr[1], skw->port[1], skw->af); } if (sks) { printf(" stack: "); if (sks != skw) { pf_print_host(&sks->addr[0], sks->port[0], sks->af); printf(" "); pf_print_host(&sks->addr[1], sks->port[1], sks->af); } else printf("-"); } if (s) { if (proto == IPPROTO_TCP) { printf(" [lo=%u high=%u win=%u modulator=%u", s->src.seqlo, s->src.seqhi, s->src.max_win, s->src.seqdiff); if (s->src.wscale && s->dst.wscale) printf(" wscale=%u", s->src.wscale & PF_WSCALE_MASK); printf("]"); printf(" [lo=%u high=%u win=%u modulator=%u", s->dst.seqlo, s->dst.seqhi, s->dst.max_win, s->dst.seqdiff); if (s->src.wscale && s->dst.wscale) printf(" wscale=%u", s->dst.wscale & PF_WSCALE_MASK); printf("]"); } printf(" %u:%u", s->src.state, s->dst.state); } } void pf_print_flags(u_int8_t f) { if (f) printf(" "); if (f & TH_FIN) printf("F"); if (f & TH_SYN) printf("S"); if (f & TH_RST) printf("R"); if (f & TH_PUSH) printf("P"); if (f & TH_ACK) printf("A"); if (f & TH_URG) printf("U"); if (f & TH_ECE) printf("E"); if (f & TH_CWR) printf("W"); } #define PF_SET_SKIP_STEPS(i) \ do { \ while (head[i] != cur) { \ head[i]->skip[i].ptr = cur; \ head[i] = TAILQ_NEXT(head[i], entries); \ } \ } while (0) void pf_calc_skip_steps(struct pf_rulequeue *rules) { struct pf_rule *cur, *prev, *head[PF_SKIP_COUNT]; int i; cur = TAILQ_FIRST(rules); prev = cur; for (i = 0; i < PF_SKIP_COUNT; ++i) head[i] = cur; while (cur != NULL) { if (cur->kif != prev->kif || cur->ifnot != prev->ifnot) PF_SET_SKIP_STEPS(PF_SKIP_IFP); if (cur->direction != prev->direction) PF_SET_SKIP_STEPS(PF_SKIP_DIR); if (cur->af != prev->af) PF_SET_SKIP_STEPS(PF_SKIP_AF); if (cur->proto != prev->proto) PF_SET_SKIP_STEPS(PF_SKIP_PROTO); if (cur->src.neg != prev->src.neg || pf_addr_wrap_neq(&cur->src.addr, &prev->src.addr)) PF_SET_SKIP_STEPS(PF_SKIP_SRC_ADDR); if (cur->src.port[0] != prev->src.port[0] || cur->src.port[1] != prev->src.port[1] || cur->src.port_op != prev->src.port_op) PF_SET_SKIP_STEPS(PF_SKIP_SRC_PORT); if (cur->dst.neg != prev->dst.neg || pf_addr_wrap_neq(&cur->dst.addr, &prev->dst.addr)) PF_SET_SKIP_STEPS(PF_SKIP_DST_ADDR); if (cur->dst.port[0] != prev->dst.port[0] || cur->dst.port[1] != prev->dst.port[1] || cur->dst.port_op != prev->dst.port_op) PF_SET_SKIP_STEPS(PF_SKIP_DST_PORT); prev = cur; cur = TAILQ_NEXT(cur, entries); } for (i = 0; i < PF_SKIP_COUNT; ++i) PF_SET_SKIP_STEPS(i); } int pf_addr_wrap_neq(struct pf_addr_wrap *aw1, struct pf_addr_wrap *aw2) { if (aw1->type != aw2->type) return (1); switch (aw1->type) { case PF_ADDR_ADDRMASK: case PF_ADDR_RANGE: if (PF_ANEQ(&aw1->v.a.addr, &aw2->v.a.addr, 0)) return (1); if (PF_ANEQ(&aw1->v.a.mask, &aw2->v.a.mask, 0)) return (1); return (0); case PF_ADDR_DYNIFTL: return (aw1->p.dyn->pfid_kt != aw2->p.dyn->pfid_kt); case PF_ADDR_NOROUTE: case PF_ADDR_URPFFAILED: return (0); case PF_ADDR_TABLE: return (aw1->p.tbl != aw2->p.tbl); case PF_ADDR_RTLABEL: return (aw1->v.rtlabel != aw2->v.rtlabel); default: printf("invalid address type: %d\n", aw1->type); return (1); } } u_int16_t pf_cksum_fixup(u_int16_t cksum, u_int16_t old, u_int16_t new, u_int8_t udp) { u_int32_t l; if (udp && !cksum) return (0x0000); l = cksum + old - new; l = (l >> 16) + (l & 65535); l = l & 65535; if (udp && !l) return (0xFFFF); return (l); } void pf_change_ap(struct pf_addr *a, u_int16_t *p, u_int16_t *ic, u_int16_t *pc, struct pf_addr *an, u_int16_t pn, u_int8_t u, sa_family_t af) { struct pf_addr ao; u_int16_t po = *p; PF_ACPY(&ao, a, af); PF_ACPY(a, an, af); *p = pn; switch (af) { #ifdef INET case AF_INET: *ic = pf_cksum_fixup(pf_cksum_fixup(*ic, ao.addr16[0], an->addr16[0], 0), ao.addr16[1], an->addr16[1], 0); *p = pn; *pc = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(*pc, ao.addr16[0], an->addr16[0], u), ao.addr16[1], an->addr16[1], u), po, pn, u); break; #endif /* INET */ #ifdef INET6 case AF_INET6: *pc = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup( pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup( pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(*pc, ao.addr16[0], an->addr16[0], u), ao.addr16[1], an->addr16[1], u), ao.addr16[2], an->addr16[2], u), ao.addr16[3], an->addr16[3], u), ao.addr16[4], an->addr16[4], u), ao.addr16[5], an->addr16[5], u), ao.addr16[6], an->addr16[6], u), ao.addr16[7], an->addr16[7], u), po, pn, u); break; #endif /* INET6 */ } } /* Changes a u_int32_t. Uses a void * so there are no align restrictions */ void pf_change_a(void *a, u_int16_t *c, u_int32_t an, u_int8_t u) { u_int32_t ao; memcpy(&ao, a, sizeof(ao)); memcpy(a, &an, sizeof(u_int32_t)); *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 */ int pf_icmp_mapping(struct pf_pdesc *pd, u_int8_t type, int *icmp_dir, int *multi, u_int16_t *icmpid, u_int16_t *icmptype) { /* * ICMP types marked with PF_OUT are typically responses to * PF_IN, and will match states in the opposite direction. * PF_IN ICMP types need to match a state with that type. */ *icmp_dir = PF_OUT; *multi = PF_ICMP_MULTI_LINK; /* Queries (and responses) */ switch (type) { case ICMP_ECHO: *icmp_dir = PF_IN; case ICMP_ECHOREPLY: *icmptype = ICMP_ECHO; *icmpid = pd->hdr.icmp->icmp_id; break; case ICMP_TSTAMP: *icmp_dir = PF_IN; case ICMP_TSTAMPREPLY: *icmptype = ICMP_TSTAMP; *icmpid = pd->hdr.icmp->icmp_id; break; case ICMP_IREQ: *icmp_dir = PF_IN; case ICMP_IREQREPLY: *icmptype = ICMP_IREQ; *icmpid = pd->hdr.icmp->icmp_id; break; case ICMP_MASKREQ: *icmp_dir = PF_IN; case ICMP_MASKREPLY: *icmptype = ICMP_MASKREQ; *icmpid = pd->hdr.icmp->icmp_id; break; case ICMP_IPV6_WHEREAREYOU: *icmp_dir = PF_IN; case ICMP_IPV6_IAMHERE: *icmptype = ICMP_IPV6_WHEREAREYOU; *icmpid = 0; /* Nothing sane to match on! */ break; case ICMP_MOBILE_REGREQUEST: *icmp_dir = PF_IN; case ICMP_MOBILE_REGREPLY: *icmptype = ICMP_MOBILE_REGREQUEST; *icmpid = 0; /* Nothing sane to match on! */ break; case ICMP_ROUTERSOLICIT: *icmp_dir = PF_IN; case ICMP_ROUTERADVERT: *icmptype = ICMP_ROUTERSOLICIT; *icmpid = 0; /* Nothing sane to match on! */ break; #ifdef INET6 case ICMP6_ECHO_REQUEST: *icmp_dir = PF_IN; case ICMP6_ECHO_REPLY: *icmptype = ICMP6_ECHO_REQUEST; *icmpid = pd->hdr.icmp6->icmp6_id; break; case MLD_LISTENER_QUERY: *icmp_dir = PF_IN; case MLD_LISTENER_REPORT: { struct mld_hdr *mld = (void *)pd->hdr.icmp6; *icmptype = MLD_LISTENER_QUERY; /* generate fake id for these messages */ *icmpid = (mld->mld_addr.s6_addr32[0] ^ mld->mld_addr.s6_addr32[1] ^ mld->mld_addr.s6_addr32[2] ^ mld->mld_addr.s6_addr32[3]) & 0xffff; break; } /* ICMP6_FQDN and ICMP6_NI query/reply are the same type as ICMP6_WRU */ case ICMP6_WRUREQUEST: *icmp_dir = PF_IN; case ICMP6_WRUREPLY: *icmptype = ICMP6_WRUREQUEST; *icmpid = 0; /* Nothing sane to match on! */ break; case MLD_MTRACE: *icmp_dir = PF_IN; case MLD_MTRACE_RESP: *icmptype = MLD_MTRACE; *icmpid = 0; /* Nothing sane to match on! */ break; case ND_NEIGHBOR_SOLICIT: *icmp_dir = PF_IN; case ND_NEIGHBOR_ADVERT: { struct nd_neighbor_solicit *nd = (void *)pd->hdr.icmp6; *icmptype = ND_NEIGHBOR_SOLICIT; *multi = PF_ICMP_MULTI_SOLICITED; /* generate fake id for these messages */ *icmpid = (nd->nd_ns_target.s6_addr32[0] ^ nd->nd_ns_target.s6_addr32[1] ^ nd->nd_ns_target.s6_addr32[2] ^ nd->nd_ns_target.s6_addr32[3]) & 0xffff; break; } #endif /* INET6 */ /* These ICMP types map to other connections */ case ICMP_UNREACH: case ICMP_SOURCEQUENCH: case ICMP_REDIRECT: case ICMP_TIMXCEED: case ICMP_PARAMPROB: #ifdef INET6 /* * ICMP6_TIME_EXCEEDED is the same type as ICMP_UNREACH * ND_REDIRECT can't be in this list because the triggering packet * header is optional. */ case ICMP6_PACKET_TOO_BIG: #endif /* INET6 */ /* These will not be used, but set them anyways */ *icmp_dir = PF_IN; *icmptype = htons(type); *icmpid = 0; return (1); /* These types are matched to other state */ /* * All remaining ICMP types get their own states, * and will only match in one direction. */ default: *icmp_dir = PF_IN; *icmptype = type; *icmpid = 0; break; } HTONS(*icmptype); return (0); } void pf_change_icmp(struct pf_addr *ia, u_int16_t *ip, struct pf_addr *oa, struct pf_addr *na, u_int16_t np, u_int16_t *pc, u_int16_t *h2c, u_int16_t *ic, u_int16_t *hc, u_int8_t u, sa_family_t af) { struct pf_addr oia, ooa; PF_ACPY(&oia, ia, af); if (oa) PF_ACPY(&ooa, oa, af); /* Change inner protocol port, fix inner protocol checksum. */ if (ip != NULL) { u_int16_t oip = *ip; u_int32_t opc; if (pc != NULL) opc = *pc; *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); } /* Change inner ip address, fix inner ip and icmp checksums. */ PF_ACPY(ia, na, af); switch (af) { #ifdef INET case AF_INET: { u_int32_t oh2c = *h2c; *h2c = pf_cksum_fixup(pf_cksum_fixup(*h2c, oia.addr16[0], ia->addr16[0], 0), oia.addr16[1], ia->addr16[1], 0); *ic = pf_cksum_fixup(pf_cksum_fixup(*ic, oia.addr16[0], ia->addr16[0], 0), oia.addr16[1], ia->addr16[1], 0); *ic = pf_cksum_fixup(*ic, oh2c, *h2c, 0); break; } #endif /* INET */ #ifdef INET6 case AF_INET6: *ic = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup( pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup( pf_cksum_fixup(pf_cksum_fixup(*ic, oia.addr16[0], ia->addr16[0], u), oia.addr16[1], ia->addr16[1], u), oia.addr16[2], ia->addr16[2], u), oia.addr16[3], ia->addr16[3], u), oia.addr16[4], ia->addr16[4], u), oia.addr16[5], ia->addr16[5], u), oia.addr16[6], ia->addr16[6], u), oia.addr16[7], ia->addr16[7], u); break; #endif /* INET6 */ } /* Outer ip address, fix outer ip or icmpv6 checksum, if necessary. */ if (oa) { 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 */ } } } /* * Need to modulate the sequence numbers in the TCP SACK option * (credits to Krzysztof Pfaff for report and patch) */ int pf_modulate_sack(struct mbuf *m, int off, struct pf_pdesc *pd, struct tcphdr *th, struct pf_state_peer *dst) { int hlen = (th->th_off << 2) - sizeof(*th), thoptlen = hlen; u_int8_t opts[MAX_TCPOPTLEN], *opt = opts; int copyback = 0, i, olen; struct sackblk sack; #define TCPOLEN_SACKLEN (TCPOLEN_SACK + 2) if (hlen < TCPOLEN_SACKLEN || !pf_pull_hdr(m, off + sizeof(*th), opts, hlen, NULL, NULL, pd->af)) return 0; while (hlen >= TCPOLEN_SACKLEN) { olen = opt[1]; switch (*opt) { case TCPOPT_EOL: /* FALLTHROUGH */ case TCPOPT_NOP: opt++; hlen--; break; case TCPOPT_SACK: if (olen > hlen) olen = hlen; if (olen >= TCPOLEN_SACKLEN) { for (i = 2; i + TCPOLEN_SACK <= olen; i += TCPOLEN_SACK) { memcpy(&sack, &opt[i], sizeof(sack)); pf_change_a(&sack.start, &th->th_sum, htonl(ntohl(sack.start) - dst->seqdiff), 0); pf_change_a(&sack.end, &th->th_sum, htonl(ntohl(sack.end) - dst->seqdiff), 0); memcpy(&opt[i], &sack, sizeof(sack)); } copyback = 1; } /* FALLTHROUGH */ default: if (olen < 2) olen = 2; hlen -= olen; opt += olen; } } if (copyback) m_copyback(m, off + sizeof(*th), thoptlen, opts); return (copyback); } void pf_send_tcp(const struct pf_rule *r, sa_family_t af, const struct pf_addr *saddr, const struct pf_addr *daddr, u_int16_t sport, u_int16_t dport, u_int32_t seq, u_int32_t ack, u_int8_t flags, u_int16_t win, u_int16_t mss, u_int8_t ttl, int tag, u_int16_t rtag, struct ether_header *eh, struct ifnet *ifp, u_int rtableid) { struct mbuf *m; int len, tlen; #ifdef INET struct ip *h; #endif /* INET */ #ifdef INET6 struct ip6_hdr *h6; #endif /* INET6 */ struct tcphdr *th; char *opt; /* maximum segment size tcp option */ tlen = sizeof(struct tcphdr); if (mss) tlen += 4; switch (af) { #ifdef INET case AF_INET: len = sizeof(struct ip) + tlen; break; #endif /* INET */ #ifdef INET6 case AF_INET6: len = sizeof(struct ip6_hdr) + tlen; break; #endif /* INET6 */ } /* create outgoing mbuf */ m = m_gethdr(M_DONTWAIT, MT_HEADER); if (m == NULL) return; if (tag) m->m_pkthdr.pf.flags |= PF_TAG_GENERATED; m->m_pkthdr.pf.tag = rtag; if (rtableid >= 0) m->m_pkthdr.pf.rtableid = rtableid; #ifdef ALTQ if (r != NULL && r->qid) { m->m_pkthdr.pf.qid = r->qid; /* add hints for ecn */ m->m_pkthdr.pf.hdr = mtod(m, struct ip *); } #endif /* ALTQ */ 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: h = mtod(m, struct ip *); /* IP header fields included in the TCP checksum */ h->ip_p = IPPROTO_TCP; h->ip_len = htons(tlen); h->ip_src.s_addr = saddr->v4.s_addr; h->ip_dst.s_addr = daddr->v4.s_addr; th = (struct tcphdr *)((caddr_t)h + sizeof(struct ip)); break; #endif /* INET */ #ifdef INET6 case AF_INET6: h6 = mtod(m, struct ip6_hdr *); /* IP header fields included in the TCP checksum */ h6->ip6_nxt = IPPROTO_TCP; h6->ip6_plen = htons(tlen); memcpy(&h6->ip6_src, &saddr->v6, sizeof(struct in6_addr)); memcpy(&h6->ip6_dst, &daddr->v6, sizeof(struct in6_addr)); th = (struct tcphdr *)((caddr_t)h6 + sizeof(struct ip6_hdr)); break; #endif /* INET6 */ } /* TCP header */ th->th_sport = sport; th->th_dport = dport; th->th_seq = htonl(seq); th->th_ack = htonl(ack); th->th_off = tlen >> 2; th->th_flags = flags; th->th_win = htons(win); if (mss) { opt = (char *)(th + 1); opt[0] = TCPOPT_MAXSEG; opt[1] = 4; HTONS(mss); bcopy((caddr_t)&mss, (caddr_t)(opt + 2), 2); } switch (af) { #ifdef INET case AF_INET: /* TCP checksum */ th->th_sum = in_cksum(m, len); /* Finish the IP header */ h->ip_v = 4; h->ip_hl = sizeof(*h) >> 2; h->ip_tos = IPTOS_LOWDELAY; h->ip_len = htons(len); h->ip_off = htons(ip_mtudisc ? IP_DF : 0); h->ip_ttl = ttl ? ttl : ip_defttl; h->ip_sum = 0; if (eh == NULL) { ip_output(m, (void *)NULL, (void *)NULL, 0, (void *)NULL, (void *)NULL); } else { struct route ro; struct rtentry rt; struct ether_header *e = (void *)ro.ro_dst.sa_data; if (ifp == NULL) { m_freem(m); return; } rt.rt_ifp = ifp; ro.ro_rt = &rt; ro.ro_dst.sa_len = sizeof(ro.ro_dst); ro.ro_dst.sa_family = pseudo_AF_HDRCMPLT; bcopy(eh->ether_dhost, e->ether_shost, ETHER_ADDR_LEN); bcopy(eh->ether_shost, e->ether_dhost, ETHER_ADDR_LEN); e->ether_type = eh->ether_type; ip_output(m, (void *)NULL, &ro, IP_ROUTETOETHER, (void *)NULL, (void *)NULL); } break; #endif /* INET */ #ifdef INET6 case AF_INET6: /* TCP checksum */ th->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(struct ip6_hdr), tlen); h6->ip6_vfc |= IPV6_VERSION; h6->ip6_hlim = IPV6_DEFHLIM; ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); break; #endif /* INET6 */ } } void pf_send_icmp(struct mbuf *m, u_int8_t type, u_int8_t code, sa_family_t af, struct pf_rule *r, u_int rtableid) { struct mbuf *m0; if ((m0 = m_copy(m, 0, M_COPYALL)) == NULL) return; m0->m_pkthdr.pf.flags |= PF_TAG_GENERATED; if (rtableid >= 0) m0->m_pkthdr.pf.rtableid = rtableid; #ifdef ALTQ if (r->qid) { m0->m_pkthdr.pf.qid = r->qid; /* add hints for ecn */ m0->m_pkthdr.pf.hdr = mtod(m0, struct ip *); } #endif /* ALTQ */ switch (af) { #ifdef INET case AF_INET: icmp_error(m0, type, code, 0, 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: icmp6_error(m0, type, code, 0); break; #endif /* INET6 */ } } /* * Return 1 if the addresses a and b match (with mask m), otherwise return 0. * If n is 0, they match if they are equal. If n is != 0, they match if they * are different. */ int pf_match_addr(u_int8_t n, struct pf_addr *a, struct pf_addr *m, struct pf_addr *b, sa_family_t af) { int match = 0; switch (af) { #ifdef INET case AF_INET: if ((a->addr32[0] & m->addr32[0]) == (b->addr32[0] & m->addr32[0])) match++; break; #endif /* INET */ #ifdef INET6 case AF_INET6: if (((a->addr32[0] & m->addr32[0]) == (b->addr32[0] & m->addr32[0])) && ((a->addr32[1] & m->addr32[1]) == (b->addr32[1] & m->addr32[1])) && ((a->addr32[2] & m->addr32[2]) == (b->addr32[2] & m->addr32[2])) && ((a->addr32[3] & m->addr32[3]) == (b->addr32[3] & m->addr32[3]))) match++; break; #endif /* INET6 */ } if (match) { if (n) return (0); else return (1); } else { if (n) return (1); else return (0); } } /* * Return 1 if b <= a <= e, otherwise return 0. */ int pf_match_addr_range(struct pf_addr *b, struct pf_addr *e, struct pf_addr *a, sa_family_t af) { switch (af) { #ifdef INET case AF_INET: if ((a->addr32[0] < b->addr32[0]) || (a->addr32[0] > e->addr32[0])) return (0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: { int i; /* check a >= b */ for (i = 0; i < 4; ++i) if (a->addr32[i] > b->addr32[i]) break; else if (a->addr32[i] < b->addr32[i]) return (0); /* check a <= e */ for (i = 0; i < 4; ++i) if (a->addr32[i] < e->addr32[i]) break; else if (a->addr32[i] > e->addr32[i]) return (0); break; } #endif /* INET6 */ } return (1); } int pf_match(u_int8_t op, u_int32_t a1, u_int32_t a2, u_int32_t p) { switch (op) { case PF_OP_IRG: return ((p > a1) && (p < a2)); case PF_OP_XRG: return ((p < a1) || (p > a2)); case PF_OP_RRG: return ((p >= a1) && (p <= a2)); case PF_OP_EQ: return (p == a1); case PF_OP_NE: return (p != a1); case PF_OP_LT: return (p < a1); case PF_OP_LE: return (p <= a1); case PF_OP_GT: return (p > a1); case PF_OP_GE: return (p >= a1); } return (0); /* never reached */ } int pf_match_port(u_int8_t op, u_int16_t a1, u_int16_t a2, u_int16_t p) { NTOHS(a1); NTOHS(a2); NTOHS(p); return (pf_match(op, a1, a2, p)); } int pf_match_uid(u_int8_t op, uid_t a1, uid_t a2, uid_t u) { if (u == UID_MAX && op != PF_OP_EQ && op != PF_OP_NE) return (0); return (pf_match(op, a1, a2, u)); } int pf_match_gid(u_int8_t op, gid_t a1, gid_t a2, gid_t g) { if (g == GID_MAX && op != PF_OP_EQ && op != PF_OP_NE) return (0); return (pf_match(op, a1, a2, g)); } int pf_match_tag(struct mbuf *m, struct pf_rule *r, int *tag) { if (*tag == -1) *tag = m->m_pkthdr.pf.tag; return ((!r->match_tag_not && r->match_tag == *tag) || (r->match_tag_not && r->match_tag != *tag)); } int pf_tag_packet(struct mbuf *m, int tag, int rtableid) { if (tag <= 0 && rtableid < 0) return (0); if (tag > 0) m->m_pkthdr.pf.tag = tag; if (rtableid >= 0) m->m_pkthdr.pf.rtableid = rtableid; return (0); } void pf_step_into_anchor(int *depth, struct pf_ruleset **rs, int n, struct pf_rule **r, struct pf_rule **a, int *match) { struct pf_anchor_stackframe *f; (*r)->anchor->match = 0; if (match) *match = 0; if (*depth >= sizeof(pf_anchor_stack) / sizeof(pf_anchor_stack[0])) { printf("pf_step_into_anchor: stack overflow\n"); *r = TAILQ_NEXT(*r, entries); return; } else if (*depth == 0 && a != NULL) *a = *r; f = pf_anchor_stack + (*depth)++; f->rs = *rs; f->r = *r; if ((*r)->anchor_wildcard) { f->parent = &(*r)->anchor->children; if ((f->child = RB_MIN(pf_anchor_node, f->parent)) == NULL) { *r = NULL; return; } *rs = &f->child->ruleset; } else { f->parent = NULL; f->child = NULL; *rs = &(*r)->anchor->ruleset; } *r = TAILQ_FIRST((*rs)->rules[n].active.ptr); } int pf_step_out_of_anchor(int *depth, struct pf_ruleset **rs, int n, struct pf_rule **r, struct pf_rule **a, int *match) { struct pf_anchor_stackframe *f; int quick = 0; do { if (*depth <= 0) break; f = pf_anchor_stack + *depth - 1; if (f->parent != NULL && f->child != NULL) { if (f->child->match || (match != NULL && *match)) { f->r->anchor->match = 1; *match = 0; } f->child = RB_NEXT(pf_anchor_node, f->parent, f->child); if (f->child != NULL) { *rs = &f->child->ruleset; *r = TAILQ_FIRST((*rs)->rules[n].active.ptr); if (*r == NULL) continue; else break; } } (*depth)--; if (*depth == 0 && a != NULL) *a = NULL; *rs = f->rs; if (f->r->anchor->match || (match != NULL && *match)) quick = f->r->quick; *r = TAILQ_NEXT(f->r, entries); } while (*r == NULL); return (quick); } #ifdef INET6 void pf_poolmask(struct pf_addr *naddr, struct pf_addr *raddr, struct pf_addr *rmask, struct pf_addr *saddr, sa_family_t af) { switch (af) { #ifdef INET case AF_INET: naddr->addr32[0] = (raddr->addr32[0] & rmask->addr32[0]) | ((rmask->addr32[0] ^ 0xffffffff ) & saddr->addr32[0]); break; #endif /* INET */ case AF_INET6: naddr->addr32[0] = (raddr->addr32[0] & rmask->addr32[0]) | ((rmask->addr32[0] ^ 0xffffffff ) & saddr->addr32[0]); naddr->addr32[1] = (raddr->addr32[1] & rmask->addr32[1]) | ((rmask->addr32[1] ^ 0xffffffff ) & saddr->addr32[1]); naddr->addr32[2] = (raddr->addr32[2] & rmask->addr32[2]) | ((rmask->addr32[2] ^ 0xffffffff ) & saddr->addr32[2]); naddr->addr32[3] = (raddr->addr32[3] & rmask->addr32[3]) | ((rmask->addr32[3] ^ 0xffffffff ) & saddr->addr32[3]); break; } } void pf_addr_inc(struct pf_addr *addr, sa_family_t af) { switch (af) { #ifdef INET case AF_INET: addr->addr32[0] = htonl(ntohl(addr->addr32[0]) + 1); break; #endif /* INET */ case AF_INET6: if (addr->addr32[3] == 0xffffffff) { addr->addr32[3] = 0; if (addr->addr32[2] == 0xffffffff) { addr->addr32[2] = 0; if (addr->addr32[1] == 0xffffffff) { addr->addr32[1] = 0; addr->addr32[0] = htonl(ntohl(addr->addr32[0]) + 1); } else addr->addr32[1] = htonl(ntohl(addr->addr32[1]) + 1); } else addr->addr32[2] = htonl(ntohl(addr->addr32[2]) + 1); } else addr->addr32[3] = htonl(ntohl(addr->addr32[3]) + 1); break; } } #endif /* INET6 */ int pf_socket_lookup(int direction, struct pf_pdesc *pd) { struct pf_addr *saddr, *daddr; u_int16_t sport, dport; struct inpcbtable *tb; struct inpcb *inp; if (pd == NULL) return (-1); pd->lookup.uid = UID_MAX; pd->lookup.gid = GID_MAX; pd->lookup.pid = NO_PID; switch (pd->proto) { case IPPROTO_TCP: if (pd->hdr.tcp == NULL) return (-1); sport = pd->hdr.tcp->th_sport; dport = pd->hdr.tcp->th_dport; tb = &tcbtable; break; case IPPROTO_UDP: if (pd->hdr.udp == NULL) return (-1); sport = pd->hdr.udp->uh_sport; dport = pd->hdr.udp->uh_dport; tb = &udbtable; break; default: return (-1); } if (direction == PF_IN) { saddr = pd->src; daddr = pd->dst; } else { u_int16_t p; p = sport; sport = dport; dport = p; saddr = pd->dst; daddr = pd->src; } switch (pd->af) { #ifdef INET case AF_INET: inp = in_pcbhashlookup(tb, saddr->v4, sport, daddr->v4, dport); if (inp == NULL) { inp = in_pcblookup_listen(tb, daddr->v4, dport, 0, NULL); if (inp == NULL) return (-1); } break; #endif /* INET */ #ifdef INET6 case AF_INET6: inp = in6_pcbhashlookup(tb, &saddr->v6, sport, &daddr->v6, dport); if (inp == NULL) { inp = in6_pcblookup_listen(tb, &daddr->v6, dport, 0, NULL); if (inp == NULL) return (-1); } break; #endif /* INET6 */ default: return (-1); } pd->lookup.uid = inp->inp_socket->so_euid; pd->lookup.gid = inp->inp_socket->so_egid; pd->lookup.pid = inp->inp_socket->so_cpid; return (1); } u_int8_t pf_get_wscale(struct mbuf *m, int off, u_int16_t th_off, sa_family_t af) { int hlen; u_int8_t hdr[60]; u_int8_t *opt, optlen; u_int8_t wscale = 0; hlen = th_off << 2; /* hlen <= sizeof(hdr) */ if (hlen <= sizeof(struct tcphdr)) return (0); if (!pf_pull_hdr(m, off, hdr, hlen, NULL, NULL, af)) return (0); opt = hdr + sizeof(struct tcphdr); hlen -= sizeof(struct tcphdr); while (hlen >= 3) { switch (*opt) { case TCPOPT_EOL: case TCPOPT_NOP: ++opt; --hlen; break; case TCPOPT_WINDOW: wscale = opt[2]; if (wscale > TCP_MAX_WINSHIFT) wscale = TCP_MAX_WINSHIFT; wscale |= PF_WSCALE_FLAG; /* FALLTHROUGH */ default: optlen = opt[1]; if (optlen < 2) optlen = 2; hlen -= optlen; opt += optlen; break; } } return (wscale); } u_int16_t pf_get_mss(struct mbuf *m, int off, u_int16_t th_off, sa_family_t af) { int hlen; u_int8_t hdr[60]; u_int8_t *opt, optlen; u_int16_t mss = tcp_mssdflt; hlen = th_off << 2; /* hlen <= sizeof(hdr) */ if (hlen <= sizeof(struct tcphdr)) return (0); if (!pf_pull_hdr(m, off, hdr, hlen, NULL, NULL, af)) return (0); opt = hdr + sizeof(struct tcphdr); hlen -= sizeof(struct tcphdr); while (hlen >= TCPOLEN_MAXSEG) { switch (*opt) { case TCPOPT_EOL: case TCPOPT_NOP: ++opt; --hlen; break; case TCPOPT_MAXSEG: bcopy((caddr_t)(opt + 2), (caddr_t)&mss, 2); NTOHS(mss); /* FALLTHROUGH */ default: optlen = opt[1]; if (optlen < 2) optlen = 2; hlen -= optlen; opt += optlen; break; } } return (mss); } u_int16_t pf_calc_mss(struct pf_addr *addr, sa_family_t af, u_int16_t offer) { #ifdef INET struct sockaddr_in *dst; struct route ro; #endif /* INET */ #ifdef INET6 struct sockaddr_in6 *dst6; struct route_in6 ro6; #endif /* INET6 */ struct rtentry *rt = NULL; int hlen; u_int16_t mss = tcp_mssdflt; switch (af) { #ifdef INET case AF_INET: hlen = sizeof(struct ip); bzero(&ro, sizeof(ro)); dst = (struct sockaddr_in *)&ro.ro_dst; dst->sin_family = AF_INET; dst->sin_len = sizeof(*dst); dst->sin_addr = addr->v4; rtalloc_noclone(&ro, NO_CLONING); rt = ro.ro_rt; break; #endif /* INET */ #ifdef INET6 case AF_INET6: hlen = sizeof(struct ip6_hdr); bzero(&ro6, sizeof(ro6)); dst6 = (struct sockaddr_in6 *)&ro6.ro_dst; dst6->sin6_family = AF_INET6; dst6->sin6_len = sizeof(*dst6); dst6->sin6_addr = addr->v6; rtalloc_noclone((struct route *)&ro6, NO_CLONING); rt = ro6.ro_rt; break; #endif /* INET6 */ } if (rt && rt->rt_ifp) { mss = rt->rt_ifp->if_mtu - hlen - sizeof(struct tcphdr); mss = max(tcp_mssdflt, mss); RTFREE(rt); } mss = min(mss, offer); mss = max(mss, 64); /* sanity - at least max opt space */ return (mss); } void pf_set_rt_ifp(struct pf_state *s, struct pf_addr *saddr) { struct pf_rule *r = s->rule.ptr; struct pf_src_node *sn = NULL; s->rt_kif = NULL; if (!r->rt || r->rt == PF_FASTROUTE) return; switch (s->key[PF_SK_WIRE]->af) { #ifdef INET case AF_INET: pf_map_addr(AF_INET, r, saddr, &s->rt_addr, NULL, &sn); s->rt_kif = r->rpool.cur->kif; break; #endif /* INET */ #ifdef INET6 case AF_INET6: pf_map_addr(AF_INET6, r, saddr, &s->rt_addr, NULL, &sn); s->rt_kif = r->rpool.cur->kif; break; #endif /* INET6 */ } } u_int32_t pf_tcp_iss(struct pf_pdesc *pd) { MD5_CTX ctx; u_int32_t digest[4]; if (pf_tcp_secret_init == 0) { arc4random_buf(pf_tcp_secret, sizeof(pf_tcp_secret)); MD5Init(&pf_tcp_secret_ctx); MD5Update(&pf_tcp_secret_ctx, pf_tcp_secret, sizeof(pf_tcp_secret)); pf_tcp_secret_init = 1; } ctx = pf_tcp_secret_ctx; MD5Update(&ctx, (char *)&pd->hdr.tcp->th_sport, sizeof(u_short)); MD5Update(&ctx, (char *)&pd->hdr.tcp->th_dport, sizeof(u_short)); if (pd->af == AF_INET6) { MD5Update(&ctx, (char *)&pd->src->v6, sizeof(struct in6_addr)); MD5Update(&ctx, (char *)&pd->dst->v6, sizeof(struct in6_addr)); } else { MD5Update(&ctx, (char *)&pd->src->v4, sizeof(struct in_addr)); MD5Update(&ctx, (char *)&pd->dst->v4, sizeof(struct in_addr)); } MD5Final((u_char *)digest, &ctx); pf_tcp_iss_off += 4096; return (digest[0] + tcp_iss + pf_tcp_iss_off); } void pf_rule_to_actions(struct pf_rule *r, struct pf_rule_actions *a) { if (r->qid) a->qid = r->qid; if (r->pqid) a->pqid = r->pqid; if (r->rtableid >= 0) a->rtableid = r->rtableid; a->log |= r->log; if (r->scrub_flags & PFSTATE_SETTOS) a->set_tos = r->set_tos; if (r->min_ttl) a->min_ttl = r->min_ttl; if (r->max_mss) a->max_mss = r->max_mss; a->flags |= (r->scrub_flags & (PFSTATE_NODF|PFSTATE_RANDOMID| PFSTATE_SETTOS|PFSTATE_SCRUB_TCP)); } int pf_test_rule(struct pf_rule **rm, struct pf_state **sm, int direction, struct pfi_kif *kif, struct mbuf *m, int off, void *h, struct pf_pdesc *pd, struct pf_rule **am, struct pf_ruleset **rsm, struct ifqueue *ifq) { struct pf_rule *nr = NULL, *lastr = NULL; struct pf_addr *saddr = pd->src, *daddr = pd->dst; sa_family_t af = pd->af; struct pf_rule *r, *a = NULL; struct pf_ruleset *ruleset = NULL; struct pf_rule_slist rules; struct pf_rule_item *ri; struct pf_src_node *nsn = NULL; struct tcphdr *th = pd->hdr.tcp; struct pf_state_key *skw = NULL, *sks = NULL; struct pf_state_key *sk = NULL, *nk = NULL; struct pf_rule_actions act; u_short reason; int rewrite = 0, hdrlen = 0; int tag = -1; int asd = 0; int match = 0; int state_icmp = 0, icmp_dir, multi; u_int16_t sport, dport, virtual_type, virtual_id; u_int16_t bproto_sum = 0, bip_sum; u_int8_t icmptype = 0, icmpcode = 0; bzero(&act, sizeof(act)); act.rtableid = -1; if (direction == PF_IN && pf_check_congestion(ifq)) { REASON_SET(&reason, PFRES_CONGEST); return (PF_DROP); } switch (pd->proto) { case IPPROTO_TCP: sport = th->th_sport; dport = th->th_dport; hdrlen = sizeof(*th); break; case IPPROTO_UDP: sport = pd->hdr.udp->uh_sport; dport = pd->hdr.udp->uh_dport; hdrlen = sizeof(*pd->hdr.udp); break; #ifdef INET case IPPROTO_ICMP: if (pd->af != AF_INET) break; hdrlen = sizeof(*pd->hdr.icmp); icmptype = pd->hdr.icmp->icmp_type; icmpcode = pd->hdr.icmp->icmp_code; state_icmp = pf_icmp_mapping(pd, icmptype, &icmp_dir, &multi, &virtual_id, &virtual_type); if (icmp_dir == PF_IN) { sport = virtual_id; dport = virtual_type; } else { sport = virtual_type; dport = virtual_id; } break; #endif /* INET */ #ifdef INET6 case IPPROTO_ICMPV6: if (af != AF_INET6) break; hdrlen = sizeof(*pd->hdr.icmp6); icmptype = pd->hdr.icmp6->icmp6_type; icmpcode = pd->hdr.icmp6->icmp6_code; state_icmp = pf_icmp_mapping(pd, icmptype, &icmp_dir, &multi, &virtual_id, &virtual_type); if (icmp_dir == PF_IN) { sport = virtual_id; dport = virtual_type; } else { sport = virtual_type; dport = virtual_id; } break; #endif /* INET6 */ default: sport = dport = hdrlen = 0; break; } r = TAILQ_FIRST(pf_main_ruleset.rules[PF_RULESET_FILTER].active.ptr); /* check packet for BINAT/NAT/RDR */ if ((nr = pf_get_translation(pd, m, off, direction, kif, &nsn, &skw, &sks, &sk, &nk, saddr, daddr, sport, dport)) != NULL) { if (nk == NULL || sk == NULL) { REASON_SET(&reason, PFRES_MEMORY); goto cleanup; } if (pd->ip_sum) bip_sum = *pd->ip_sum; switch (pd->proto) { case IPPROTO_TCP: bproto_sum = th->th_sum; pd->proto_sum = &th->th_sum; if (PF_ANEQ(saddr, &nk->addr[pd->sidx], af) || nk->port[pd->sidx] != sport) { pf_change_ap(saddr, &th->th_sport, pd->ip_sum, &th->th_sum, &nk->addr[pd->sidx], nk->port[pd->sidx], 0, af); pd->sport = &th->th_sport; sport = th->th_sport; } if (PF_ANEQ(daddr, &nk->addr[pd->didx], af) || nk->port[pd->didx] != dport) { pf_change_ap(daddr, &th->th_dport, pd->ip_sum, &th->th_sum, &nk->addr[pd->didx], nk->port[pd->didx], 0, af); dport = th->th_dport; pd->dport = &th->th_dport; } rewrite++; break; case IPPROTO_UDP: bproto_sum = pd->hdr.udp->uh_sum; pd->proto_sum = &pd->hdr.udp->uh_sum; if (PF_ANEQ(saddr, &nk->addr[pd->sidx], af) || nk->port[pd->sidx] != sport) { pf_change_ap(saddr, &pd->hdr.udp->uh_sport, pd->ip_sum, &pd->hdr.udp->uh_sum, &nk->addr[pd->sidx], nk->port[pd->sidx], 1, af); sport = pd->hdr.udp->uh_sport; pd->sport = &pd->hdr.udp->uh_sport; } if (PF_ANEQ(daddr, &nk->addr[pd->didx], af) || nk->port[pd->didx] != dport) { pf_change_ap(daddr, &pd->hdr.udp->uh_dport, pd->ip_sum, &pd->hdr.udp->uh_sum, &nk->addr[pd->didx], nk->port[pd->didx], 1, af); dport = pd->hdr.udp->uh_dport; pd->dport = &pd->hdr.udp->uh_dport; } rewrite++; break; #ifdef INET case IPPROTO_ICMP: if (PF_ANEQ(saddr, &nk->addr[pd->sidx], AF_INET)) pf_change_a(&saddr->v4.s_addr, pd->ip_sum, nk->addr[pd->sidx].v4.s_addr, 0); if (PF_ANEQ(daddr, &nk->addr[pd->didx], AF_INET)) pf_change_a(&daddr->v4.s_addr, pd->ip_sum, nk->addr[pd->didx].v4.s_addr, 0); if (virtual_type == ICMP_ECHO && nk->port[pd->sidx] != pd->hdr.icmp->icmp_id) { pd->hdr.icmp->icmp_cksum = pf_cksum_fixup( pd->hdr.icmp->icmp_cksum, sport, nk->port[pd->sidx], 0); pd->hdr.icmp->icmp_id = nk->port[pd->sidx]; pd->sport = &pd->hdr.icmp->icmp_id; } m_copyback(m, off, ICMP_MINLEN, pd->hdr.icmp); break; #endif /* INET */ #ifdef INET6 case IPPROTO_ICMPV6: if (PF_ANEQ(saddr, &nk->addr[pd->sidx], AF_INET6)) pf_change_a6(saddr, &pd->hdr.icmp6->icmp6_cksum, &nk->addr[pd->sidx], 0); if (PF_ANEQ(daddr, &nk->addr[pd->didx], AF_INET6)) pf_change_a6(daddr, &pd->hdr.icmp6->icmp6_cksum, &nk->addr[pd->didx], 0); rewrite++; break; #endif /* INET */ default: switch (af) { #ifdef INET case AF_INET: if (PF_ANEQ(saddr, &nk->addr[pd->sidx], AF_INET)) pf_change_a(&saddr->v4.s_addr, pd->ip_sum, nk->addr[pd->sidx].v4.s_addr, 0); if (PF_ANEQ(daddr, &nk->addr[pd->didx], AF_INET)) pf_change_a(&daddr->v4.s_addr, pd->ip_sum, nk->addr[pd->didx].v4.s_addr, 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: if (PF_ANEQ(saddr, &nk->addr[pd->sidx], AF_INET6)) PF_ACPY(saddr, &nk->addr[pd->sidx], af); if (PF_ANEQ(daddr, &nk->addr[pd->didx], AF_INET6)) PF_ACPY(saddr, &nk->addr[pd->didx], af); break; #endif /* INET */ } break; } if (nr->natpass) r = NULL; pd->nat_rule = nr; } SLIST_INIT(&rules); while (r != NULL) { r->evaluations++; if (pfi_kif_match(r->kif, kif) == r->ifnot) r = r->skip[PF_SKIP_IFP].ptr; else if (r->direction && r->direction != direction) r = r->skip[PF_SKIP_DIR].ptr; else if (r->af && r->af != af) r = r->skip[PF_SKIP_AF].ptr; else if (r->proto && r->proto != pd->proto) r = r->skip[PF_SKIP_PROTO].ptr; else if (PF_MISMATCHAW(&r->src.addr, saddr, af, r->src.neg, kif)) r = r->skip[PF_SKIP_SRC_ADDR].ptr; /* tcp/udp only. port_op always 0 in other cases */ else if (r->src.port_op && !pf_match_port(r->src.port_op, r->src.port[0], r->src.port[1], sport)) r = r->skip[PF_SKIP_SRC_PORT].ptr; else if (PF_MISMATCHAW(&r->dst.addr, daddr, af, r->dst.neg, NULL)) r = r->skip[PF_SKIP_DST_ADDR].ptr; /* tcp/udp only. port_op always 0 in other cases */ else if (r->dst.port_op && !pf_match_port(r->dst.port_op, r->dst.port[0], r->dst.port[1], dport)) r = r->skip[PF_SKIP_DST_PORT].ptr; /* icmp only. type always 0 in other cases */ else if (r->type && r->type != icmptype + 1) r = TAILQ_NEXT(r, entries); /* icmp only. type always 0 in other cases */ else if (r->code && r->code != icmpcode + 1) r = TAILQ_NEXT(r, entries); else if (r->tos && !(r->tos == pd->tos)) r = TAILQ_NEXT(r, entries); else if (r->rule_flag & PFRULE_FRAGMENT) r = TAILQ_NEXT(r, entries); else if (pd->proto == IPPROTO_TCP && (r->flagset & th->th_flags) != r->flags) r = TAILQ_NEXT(r, entries); /* tcp/udp only. uid.op always 0 in other cases */ else if (r->uid.op && (pd->lookup.done || (pd->lookup.done = pf_socket_lookup(direction, pd), 1)) && !pf_match_uid(r->uid.op, r->uid.uid[0], r->uid.uid[1], pd->lookup.uid)) r = TAILQ_NEXT(r, entries); /* tcp/udp only. gid.op always 0 in other cases */ else if (r->gid.op && (pd->lookup.done || (pd->lookup.done = pf_socket_lookup(direction, pd), 1)) && !pf_match_gid(r->gid.op, r->gid.gid[0], r->gid.gid[1], pd->lookup.gid)) r = TAILQ_NEXT(r, entries); else if (r->prob && r->prob <= arc4random_uniform(UINT_MAX - 1) + 1) r = TAILQ_NEXT(r, entries); else if (r->match_tag && !pf_match_tag(m, r, &tag)) r = TAILQ_NEXT(r, entries); else if (r->os_fingerprint != PF_OSFP_ANY && (pd->proto != IPPROTO_TCP || !pf_osfp_match( pf_osfp_fingerprint(pd, m, off, th), r->os_fingerprint))) r = TAILQ_NEXT(r, entries); else { if (r->tag) tag = r->tag; if (r->anchor == NULL) { lastr = r; if (r->action == PF_MATCH) { ri = pool_get(&pf_rule_item_pl, PR_NOWAIT); ri->r = r; /* order is irrelevant */ SLIST_INSERT_HEAD(&rules, ri, entry); pf_rule_to_actions(r, &act); } else { match = 1; *rm = r; *am = a; *rsm = ruleset; } if ((*rm)->quick) break; r = TAILQ_NEXT(r, entries); } else pf_step_into_anchor(&asd, &ruleset, PF_RULESET_FILTER, &r, &a, &match); } if (r == NULL && pf_step_out_of_anchor(&asd, &ruleset, PF_RULESET_FILTER, &r, &a, &match)) break; } r = *rm; a = *am; ruleset = *rsm; /* apply actions for last matching rule */ if (lastr && lastr->action != PF_MATCH) pf_rule_to_actions(lastr, &act); REASON_SET(&reason, PFRES_MATCH); if (act.log || (nr != NULL && nr->log)) { struct pf_rule_item *mr; if (rewrite) m_copyback(m, off, hdrlen, pd->hdr.any); if (r->log) PFLOG_PACKET(kif, h, m, af, direction, reason, r->log ? r : nr, a, ruleset, pd); SLIST_FOREACH(mr, &rules, entry) if (mr->r->log) PFLOG_PACKET(kif, h, m, af, direction, reason, mr->r, a, ruleset, pd); } if ((r->action == PF_DROP) && ((r->rule_flag & PFRULE_RETURNRST) || (r->rule_flag & PFRULE_RETURNICMP) || (r->rule_flag & PFRULE_RETURN))) { /* undo NAT changes, if they have taken place */ if (nr != NULL) { PF_ACPY(saddr, &sk->addr[pd->sidx], af); PF_ACPY(daddr, &sk->addr[pd->didx], af); if (pd->sport) *pd->sport = sk->port[pd->sidx]; if (pd->dport) *pd->dport = sk->port[pd->didx]; if (pd->proto_sum) *pd->proto_sum = bproto_sum; if (pd->ip_sum) *pd->ip_sum = bip_sum; m_copyback(m, off, hdrlen, pd->hdr.any); } if (pd->proto == IPPROTO_TCP && ((r->rule_flag & PFRULE_RETURNRST) || (r->rule_flag & PFRULE_RETURN)) && !(th->th_flags & TH_RST)) { u_int32_t ack = ntohl(th->th_seq) + pd->p_len; int len = 0; struct ip *h4; struct ip6_hdr *h6; switch (af) { case AF_INET: h4 = mtod(m, struct ip *); len = ntohs(h4->ip_len) - off; break; case AF_INET6: h6 = mtod(m, struct ip6_hdr *); len = ntohs(h6->ip6_plen) - (off - sizeof(*h6)); break; } if (pf_check_proto_cksum(m, off, len, IPPROTO_TCP, af)) REASON_SET(&reason, PFRES_PROTCKSUM); else { if (th->th_flags & TH_SYN) ack++; if (th->th_flags & TH_FIN) ack++; pf_send_tcp(r, af, pd->dst, pd->src, th->th_dport, th->th_sport, ntohl(th->th_ack), ack, TH_RST|TH_ACK, 0, 0, r->return_ttl, 1, 0, pd->eh, kif->pfik_ifp, act.rtableid); } } else if (pd->proto != IPPROTO_ICMP && af == AF_INET && r->return_icmp) pf_send_icmp(m, r->return_icmp >> 8, r->return_icmp & 255, af, r, act.rtableid); else if (pd->proto != IPPROTO_ICMPV6 && af == AF_INET6 && r->return_icmp6) pf_send_icmp(m, r->return_icmp6 >> 8, r->return_icmp6 & 255, af, r, act.rtableid); } if (r->action == PF_DROP) goto cleanup; if (pf_tag_packet(m, tag, act.rtableid)) { REASON_SET(&reason, PFRES_MEMORY); goto cleanup; } if (!state_icmp && (r->keep_state || nr != NULL)) { int action; action = pf_create_state(r, nr, a, pd, nsn, skw, sks, nk, sk, m, off, sport, dport, &rewrite, kif, sm, tag, bproto_sum, bip_sum, hdrlen, &rules, &act); if (action != PF_PASS) return (action); } else { if (sk != NULL) pool_put(&pf_state_key_pl, sk); if (nk != NULL) pool_put(&pf_state_key_pl, nk); } /* copy back packet headers if we performed NAT operations */ if (rewrite) m_copyback(m, off, hdrlen, pd->hdr.any); #if NPFSYNC > 0 if (*sm != NULL && !ISSET((*sm)->state_flags, PFSTATE_NOSYNC) && direction == PF_OUT && pfsync_up()) { /* * We want the state created, but we dont * want to send this in case a partner * firewall has to know about it to allow * replies through it. */ if (pfsync_defer(*sm, m)) return (PF_DEFER); } #endif return (PF_PASS); cleanup: if (sk != NULL) pool_put(&pf_state_key_pl, sk); if (nk != NULL) pool_put(&pf_state_key_pl, nk); return (PF_DROP); } static __inline int pf_create_state(struct pf_rule *r, struct pf_rule *nr, struct pf_rule *a, struct pf_pdesc *pd, struct pf_src_node *nsn, struct pf_state_key *skw, struct pf_state_key *sks, struct pf_state_key *nk, struct pf_state_key *sk, struct mbuf *m, int off, u_int16_t sport, u_int16_t dport, int *rewrite, struct pfi_kif *kif, struct pf_state **sm, int tag, u_int16_t bproto_sum, u_int16_t bip_sum, int hdrlen, struct pf_rule_slist *rules, struct pf_rule_actions *act) { struct pf_state *s = NULL; struct pf_src_node *sn = NULL; struct tcphdr *th = pd->hdr.tcp; u_int16_t mss = tcp_mssdflt; u_short reason; /* check maximums */ if (r->max_states && (r->states_cur >= r->max_states)) { pf_status.lcounters[LCNT_STATES]++; REASON_SET(&reason, PFRES_MAXSTATES); return (PF_DROP); } /* src node for filter rule */ if ((r->rule_flag & PFRULE_SRCTRACK || r->rpool.opts & PF_POOL_STICKYADDR) && pf_insert_src_node(&sn, r, pd->src, pd->af) != 0) { REASON_SET(&reason, PFRES_SRCLIMIT); goto csfailed; } /* src node for translation rule */ if (nr != NULL && (nr->rpool.opts & PF_POOL_STICKYADDR) && pf_insert_src_node(&nsn, nr, &sk->addr[pd->sidx], pd->af)) { REASON_SET(&reason, PFRES_SRCLIMIT); goto csfailed; } s = pool_get(&pf_state_pl, PR_NOWAIT | PR_ZERO); if (s == NULL) { REASON_SET(&reason, PFRES_MEMORY); goto csfailed; } s->rule.ptr = r; s->nat_rule.ptr = nr; s->anchor.ptr = a; bcopy(rules, &s->match_rules, sizeof(s->match_rules)); STATE_INC_COUNTERS(s); if (r->allow_opts) s->state_flags |= PFSTATE_ALLOWOPTS; if (r->rule_flag & PFRULE_STATESLOPPY) s->state_flags |= PFSTATE_SLOPPY; if (r->rule_flag & PFRULE_PFLOW) s->state_flags |= PFSTATE_PFLOW; s->log = act->log & PF_LOG_ALL; s->qid = act->qid; s->pqid = act->pqid; s->rtableid = act->rtableid; s->min_ttl = act->min_ttl; s->set_tos = act->set_tos; s->max_mss = act->max_mss; s->state_flags |= act->flags; s->sync_state = PFSYNC_S_NONE; if (nr != NULL) s->log |= nr->log & PF_LOG_ALL; switch (pd->proto) { case IPPROTO_TCP: s->src.seqlo = ntohl(th->th_seq); s->src.seqhi = s->src.seqlo + pd->p_len + 1; if ((th->th_flags & (TH_SYN|TH_ACK)) == TH_SYN && r->keep_state == PF_STATE_MODULATE) { /* Generate sequence number modulator */ if ((s->src.seqdiff = pf_tcp_iss(pd) - s->src.seqlo) == 0) s->src.seqdiff = 1; pf_change_a(&th->th_seq, &th->th_sum, htonl(s->src.seqlo + s->src.seqdiff), 0); *rewrite = 1; } else s->src.seqdiff = 0; if (th->th_flags & TH_SYN) { s->src.seqhi++; s->src.wscale = pf_get_wscale(m, off, th->th_off, pd->af); } s->src.max_win = MAX(ntohs(th->th_win), 1); if (s->src.wscale & PF_WSCALE_MASK) { /* Remove scale factor from initial window */ int win = s->src.max_win; win += 1 << (s->src.wscale & PF_WSCALE_MASK); s->src.max_win = (win - 1) >> (s->src.wscale & PF_WSCALE_MASK); } if (th->th_flags & TH_FIN) s->src.seqhi++; s->dst.seqhi = 1; s->dst.max_win = 1; s->src.state = TCPS_SYN_SENT; s->dst.state = TCPS_CLOSED; s->timeout = PFTM_TCP_FIRST_PACKET; break; case IPPROTO_UDP: s->src.state = PFUDPS_SINGLE; s->dst.state = PFUDPS_NO_TRAFFIC; s->timeout = PFTM_UDP_FIRST_PACKET; break; case IPPROTO_ICMP: #ifdef INET6 case IPPROTO_ICMPV6: #endif s->timeout = PFTM_ICMP_FIRST_PACKET; break; default: s->src.state = PFOTHERS_SINGLE; s->dst.state = PFOTHERS_NO_TRAFFIC; s->timeout = PFTM_OTHER_FIRST_PACKET; } s->creation = time_second; s->expire = time_second; if (sn != NULL) { s->src_node = sn; s->src_node->states++; } if (nsn != NULL) { /* XXX We only modify one side for now. */ PF_ACPY(&nsn->raddr, &nk->addr[1], pd->af); s->nat_src_node = nsn; s->nat_src_node->states++; } if (pd->proto == IPPROTO_TCP) { if (s->state_flags & PFSTATE_SCRUB_TCP && pf_normalize_tcp_init(m, off, pd, th, &s->src, &s->dst)) { REASON_SET(&reason, PFRES_MEMORY); pf_src_tree_remove_state(s); STATE_DEC_COUNTERS(s); pool_put(&pf_state_pl, s); return (PF_DROP); } if (s->state_flags & PFSTATE_SCRUB_TCP && s->src.scrub && pf_normalize_tcp_stateful(m, off, pd, &reason, th, s, &s->src, &s->dst, rewrite)) { /* This really shouldn't happen!!! */ DPFPRINTF(PF_DEBUG_URGENT, ("pf_normalize_tcp_stateful failed on first pkt")); pf_normalize_tcp_cleanup(s); pf_src_tree_remove_state(s); STATE_DEC_COUNTERS(s); pool_put(&pf_state_pl, s); return (PF_DROP); } } s->direction = pd->dir; if (sk == NULL && pf_state_key_setup(pd, nr, &skw, &sks, &sk, &nk, pd->src, pd->dst, sport, dport)) goto csfailed; if (pf_state_insert(BOUND_IFACE(r, kif), skw, sks, s)) { if (pd->proto == IPPROTO_TCP) pf_normalize_tcp_cleanup(s); REASON_SET(&reason, PFRES_STATEINS); pf_src_tree_remove_state(s); STATE_DEC_COUNTERS(s); pool_put(&pf_state_pl, s); return (PF_DROP); } else *sm = s; pf_set_rt_ifp(s, pd->src); /* needs s->state_key set */ if (tag > 0) { pf_tag_ref(tag); s->tag = tag; } if (pd->proto == IPPROTO_TCP && (th->th_flags & (TH_SYN|TH_ACK)) == TH_SYN && r->keep_state == PF_STATE_SYNPROXY) { s->src.state = PF_TCPS_PROXY_SRC; /* undo NAT changes, if they have taken place */ if (nr != NULL) { struct pf_state_key *skt = s->key[PF_SK_WIRE]; if (pd->dir == PF_OUT) skt = s->key[PF_SK_STACK]; PF_ACPY(pd->src, &skt->addr[pd->sidx], pd->af); PF_ACPY(pd->dst, &skt->addr[pd->didx], pd->af); if (pd->sport) *pd->sport = skt->port[pd->sidx]; if (pd->dport) *pd->dport = skt->port[pd->didx]; if (pd->proto_sum) *pd->proto_sum = bproto_sum; if (pd->ip_sum) *pd->ip_sum = bip_sum; m_copyback(m, off, hdrlen, pd->hdr.any); } s->src.seqhi = htonl(arc4random()); /* Find mss option */ mss = pf_get_mss(m, off, th->th_off, pd->af); mss = pf_calc_mss(pd->src, pd->af, mss); mss = pf_calc_mss(pd->dst, pd->af, mss); s->src.mss = mss; pf_send_tcp(r, pd->af, pd->dst, pd->src, th->th_dport, th->th_sport, s->src.seqhi, ntohl(th->th_seq) + 1, TH_SYN|TH_ACK, 0, s->src.mss, 0, 1, 0, NULL, NULL, act->rtableid); REASON_SET(&reason, PFRES_SYNPROXY); return (PF_SYNPROXY_DROP); } return (PF_PASS); csfailed: if (sk != NULL) pool_put(&pf_state_key_pl, sk); if (nk != NULL) pool_put(&pf_state_key_pl, nk); if (sn != NULL && sn->states == 0 && sn->expire == 0) { RB_REMOVE(pf_src_tree, &tree_src_tracking, sn); pf_status.scounters[SCNT_SRC_NODE_REMOVALS]++; pf_status.src_nodes--; pool_put(&pf_src_tree_pl, sn); } if (nsn != sn && nsn != NULL && nsn->states == 0 && nsn->expire == 0) { RB_REMOVE(pf_src_tree, &tree_src_tracking, nsn); pf_status.scounters[SCNT_SRC_NODE_REMOVALS]++; pf_status.src_nodes--; pool_put(&pf_src_tree_pl, nsn); } return (PF_DROP); } int pf_test_fragment(struct pf_rule **rm, int direction, struct pfi_kif *kif, struct mbuf *m, void *h, struct pf_pdesc *pd, struct pf_rule **am, struct pf_ruleset **rsm) { struct pf_rule *r, *a = NULL; struct pf_ruleset *ruleset = NULL; sa_family_t af = pd->af; u_short reason; int tag = -1; int asd = 0; int match = 0; r = TAILQ_FIRST(pf_main_ruleset.rules[PF_RULESET_FILTER].active.ptr); while (r != NULL) { r->evaluations++; if (pfi_kif_match(r->kif, kif) == r->ifnot) r = r->skip[PF_SKIP_IFP].ptr; else if (r->direction && r->direction != direction) r = r->skip[PF_SKIP_DIR].ptr; else if (r->af && r->af != af) r = r->skip[PF_SKIP_AF].ptr; else if (r->proto && r->proto != pd->proto) r = r->skip[PF_SKIP_PROTO].ptr; else if (PF_MISMATCHAW(&r->src.addr, pd->src, af, r->src.neg, kif)) r = r->skip[PF_SKIP_SRC_ADDR].ptr; else if (PF_MISMATCHAW(&r->dst.addr, pd->dst, af, r->dst.neg, NULL)) r = r->skip[PF_SKIP_DST_ADDR].ptr; else if (r->tos && !(r->tos == pd->tos)) r = TAILQ_NEXT(r, entries); else if (r->os_fingerprint != PF_OSFP_ANY) r = TAILQ_NEXT(r, entries); else if (pd->proto == IPPROTO_UDP && (r->src.port_op || r->dst.port_op)) r = TAILQ_NEXT(r, entries); else if (pd->proto == IPPROTO_TCP && (r->src.port_op || r->dst.port_op || r->flagset)) r = TAILQ_NEXT(r, entries); else if ((pd->proto == IPPROTO_ICMP || pd->proto == IPPROTO_ICMPV6) && (r->type || r->code)) r = TAILQ_NEXT(r, entries); else if (r->prob && r->prob <= (arc4random() % (UINT_MAX - 1) + 1)) r = TAILQ_NEXT(r, entries); else if (r->match_tag && !pf_match_tag(m, r, &tag)) r = TAILQ_NEXT(r, entries); else { if (r->anchor == NULL) { match = 1; *rm = r; *am = a; *rsm = ruleset; if ((*rm)->quick) break; r = TAILQ_NEXT(r, entries); } else pf_step_into_anchor(&asd, &ruleset, PF_RULESET_FILTER, &r, &a, &match); } if (r == NULL && pf_step_out_of_anchor(&asd, &ruleset, PF_RULESET_FILTER, &r, &a, &match)) break; } r = *rm; a = *am; ruleset = *rsm; REASON_SET(&reason, PFRES_MATCH); if (r->log) PFLOG_PACKET(kif, h, m, af, direction, reason, r, a, ruleset, pd); if (r->action != PF_PASS) return (PF_DROP); if (pf_tag_packet(m, tag, -1)) { REASON_SET(&reason, PFRES_MEMORY); return (PF_DROP); } return (PF_PASS); } int pf_tcp_track_full(struct pf_state_peer *src, struct pf_state_peer *dst, struct pf_state **state, struct pfi_kif *kif, struct mbuf *m, int off, struct pf_pdesc *pd, u_short *reason, int *copyback) { struct tcphdr *th = pd->hdr.tcp; u_int16_t win = ntohs(th->th_win); u_int32_t ack, end, seq, orig_seq; u_int8_t sws, dws; int ackskew; if (src->wscale && dst->wscale && !(th->th_flags & TH_SYN)) { sws = src->wscale & PF_WSCALE_MASK; dws = dst->wscale & PF_WSCALE_MASK; } else sws = dws = 0; /* * Sequence tracking algorithm from Guido van Rooij's paper: * http://www.madison-gurkha.com/publications/tcp_filtering/ * tcp_filtering.ps */ orig_seq = seq = ntohl(th->th_seq); if (src->seqlo == 0) { /* First packet from this end. Set its state */ if (((*state)->state_flags & PFSTATE_SCRUB_TCP || dst->scrub) && src->scrub == NULL) { if (pf_normalize_tcp_init(m, off, pd, th, src, dst)) { REASON_SET(reason, PFRES_MEMORY); return (PF_DROP); } } /* Deferred generation of sequence number modulator */ if (dst->seqdiff && !src->seqdiff) { /* use random iss for the TCP server */ while ((src->seqdiff = arc4random() - seq) == 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); *copyback = 1; } else { ack = ntohl(th->th_ack); } end = seq + pd->p_len; if (th->th_flags & TH_SYN) { end++; if (dst->wscale & PF_WSCALE_FLAG) { src->wscale = pf_get_wscale(m, off, th->th_off, pd->af); if (src->wscale & PF_WSCALE_FLAG) { /* Remove scale factor from initial * window */ sws = src->wscale & PF_WSCALE_MASK; win = ((u_int32_t)win + (1 << sws) - 1) >> sws; dws = dst->wscale & PF_WSCALE_MASK; } else { /* fixup other window */ dst->max_win <<= dst->wscale & PF_WSCALE_MASK; /* in case of a retrans SYN|ACK */ dst->wscale = 0; } } } if (th->th_flags & TH_FIN) end++; src->seqlo = seq; if (src->state < TCPS_SYN_SENT) src->state = TCPS_SYN_SENT; /* * May need to slide the window (seqhi may have been set by * the crappy stack check or if we picked up the connection * after establishment) */ if (src->seqhi == 1 || SEQ_GEQ(end + MAX(1, dst->max_win << dws), src->seqhi)) src->seqhi = end + MAX(1, dst->max_win << dws); if (win > src->max_win) src->max_win = win; } else { ack = ntohl(th->th_ack) - dst->seqdiff; if (src->seqdiff) { /* Modulate sequence numbers */ pf_change_a(&th->th_seq, &th->th_sum, htonl(seq + src->seqdiff), 0); pf_change_a(&th->th_ack, &th->th_sum, htonl(ack), 0); *copyback = 1; } 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; /* * Need to demodulate the sequence numbers in any TCP SACK options * (Selective ACK). We could optionally validate the SACK values * against the current ACK window, either forwards or backwards, but * I'm not confident that SACK has been implemented properly * everywhere. It wouldn't surprise me if several stacks accidently * SACK too far backwards of previously ACKed data. There really aren't * any security implications of bad SACKing unless the target stack * doesn't validate the option length correctly. Someone trying to * spoof into a TCP connection won't bother blindly sending SACK * options anyway. */ if (dst->seqdiff && (th->th_off << 2) > sizeof(struct tcphdr)) { if (pf_modulate_sack(m, off, pd, th, dst)) *copyback = 1; } #define MAXACKWINDOW (0xffff + 1500) /* 1500 is an arbitrary fudge factor */ if (SEQ_GEQ(src->seqhi, end) && /* Last octet inside other's window space */ SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)) && /* Retrans: not more than one window back */ (ackskew >= -MAXACKWINDOW) && /* Acking not more than one reassembled fragment backwards */ (ackskew <= (MAXACKWINDOW << sws)) && /* Acking not more than one window forward */ ((th->th_flags & TH_RST) == 0 || orig_seq == src->seqlo || (orig_seq == src->seqlo + 1) || (orig_seq + 1 == src->seqlo) || (pd->flags & PFDESC_IP_REAS) == 0)) { /* Require an exact/+1 sequence match on resets when possible */ if (dst->scrub || src->scrub) { if (pf_normalize_tcp_stateful(m, off, pd, reason, th, *state, src, dst, copyback)) return (PF_DROP); } /* update max window */ if (src->max_win < win) src->max_win = win; /* synchronize sequencing */ if (SEQ_GT(end, src->seqlo)) src->seqlo = end; /* slide the window of what the other end can send */ if (SEQ_GEQ(ack + (win << sws), dst->seqhi)) dst->seqhi = ack + MAX((win << sws), 1); /* update states */ if (th->th_flags & TH_SYN) if (src->state < TCPS_SYN_SENT) src->state = TCPS_SYN_SENT; if (th->th_flags & TH_FIN) if (src->state < TCPS_CLOSING) src->state = TCPS_CLOSING; if (th->th_flags & TH_ACK) { if (dst->state == TCPS_SYN_SENT) { dst->state = TCPS_ESTABLISHED; if (src->state == TCPS_ESTABLISHED && (*state)->src_node != NULL && pf_src_connlimit(state)) { REASON_SET(reason, PFRES_SRCLIMIT); return (PF_DROP); } } 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 */ (*state)->expire = time_second; if (src->state >= TCPS_FIN_WAIT_2 && dst->state >= TCPS_FIN_WAIT_2) (*state)->timeout = PFTM_TCP_CLOSED; else if (src->state >= TCPS_CLOSING && dst->state >= TCPS_CLOSING) (*state)->timeout = PFTM_TCP_FIN_WAIT; else if (src->state < TCPS_ESTABLISHED || dst->state < TCPS_ESTABLISHED) (*state)->timeout = PFTM_TCP_OPENING; else if (src->state >= TCPS_CLOSING || dst->state >= TCPS_CLOSING) (*state)->timeout = PFTM_TCP_CLOSING; else (*state)->timeout = PFTM_TCP_ESTABLISHED; /* Fall through to PASS packet */ } else if ((dst->state < TCPS_SYN_SENT || dst->state >= TCPS_FIN_WAIT_2 || src->state >= TCPS_FIN_WAIT_2) && SEQ_GEQ(src->seqhi + MAXACKWINDOW, end) && /* Within a window forward of the originating packet */ SEQ_GEQ(seq, src->seqlo - MAXACKWINDOW)) { /* Within a window backward of the originating packet */ /* * This currently handles three situations: * 1) Stupid stacks will shotgun SYNs before their peer * replies. * 2) When PF catches an already established stream (the * firewall rebooted, the state table was flushed, routes * changed...) * 3) Packets get funky immediately after the connection * closes (this should catch Solaris spurious ACK|FINs * that web servers like to spew after a close) * * This must be a little more careful than the above code * since packet floods will also be caught here. We don't * update the TTL here to mitigate the damage of a packet * flood and so the same code can handle awkward establishment * and a loosened connection close. * In the establishment case, a correct peer response will * validate the connection, go through the normal state code * and keep updating the state TTL. */ if (pf_status.debug >= PF_DEBUG_MISC) { printf("pf: loose state match: "); pf_print_state(*state); pf_print_flags(th->th_flags); printf(" seq=%u (%u) ack=%u len=%u ackskew=%d " "pkts=%llu:%llu dir=%s,%s\n", seq, orig_seq, ack, pd->p_len, ackskew, (*state)->packets[0], (*state)->packets[1], pd->dir == PF_IN ? "in" : "out", pd->dir == (*state)->direction ? "fwd" : "rev"); } if (dst->scrub || src->scrub) { if (pf_normalize_tcp_stateful(m, off, pd, reason, th, *state, src, dst, copyback)) return (PF_DROP); } /* update max window */ if (src->max_win < win) src->max_win = win; /* synchronize sequencing */ if (SEQ_GT(end, src->seqlo)) src->seqlo = end; /* slide the window of what the other end can send */ if (SEQ_GEQ(ack + (win << sws), dst->seqhi)) dst->seqhi = ack + MAX((win << sws), 1); /* * Cannot set dst->seqhi here since this could be a shotgunned * SYN and not an already established connection. */ if (th->th_flags & TH_FIN) if (src->state < TCPS_CLOSING) src->state = TCPS_CLOSING; if (th->th_flags & TH_RST) src->state = dst->state = TCPS_TIME_WAIT; /* Fall through to PASS packet */ } else { if ((*state)->dst.state == TCPS_SYN_SENT && (*state)->src.state == TCPS_SYN_SENT) { /* Send RST for state mismatches during handshake */ if (!(th->th_flags & TH_RST)) pf_send_tcp((*state)->rule.ptr, pd->af, pd->dst, pd->src, th->th_dport, th->th_sport, ntohl(th->th_ack), 0, TH_RST, 0, 0, (*state)->rule.ptr->return_ttl, 1, 0, pd->eh, kif->pfik_ifp, (*state)->rtableid); src->seqlo = 0; src->seqhi = 1; src->max_win = 1; } else if (pf_status.debug >= PF_DEBUG_MISC) { printf("pf: BAD state: "); pf_print_state(*state); pf_print_flags(th->th_flags); printf(" seq=%u (%u) ack=%u len=%u ackskew=%d " "pkts=%llu:%llu dir=%s,%s\n", seq, orig_seq, ack, pd->p_len, ackskew, (*state)->packets[0], (*state)->packets[1], pd->dir == PF_IN ? "in" : "out", pd->dir == (*state)->direction ? "fwd" : "rev"); printf("pf: State failure on: %c %c %c %c | %c %c\n", SEQ_GEQ(src->seqhi, end) ? ' ' : '1', SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)) ? ' ': '2', (ackskew >= -MAXACKWINDOW) ? ' ' : '3', (ackskew <= (MAXACKWINDOW << sws)) ? ' ' : '4', SEQ_GEQ(src->seqhi + MAXACKWINDOW, end) ?' ' :'5', SEQ_GEQ(seq, src->seqlo - MAXACKWINDOW) ?' ' :'6'); } REASON_SET(reason, PFRES_BADSTATE); return (PF_DROP); } return (PF_PASS); } int pf_tcp_track_sloppy(struct pf_state_peer *src, struct pf_state_peer *dst, struct pf_state **state, struct pf_pdesc *pd, u_short *reason) { struct tcphdr *th = pd->hdr.tcp; 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; if (src->state == TCPS_ESTABLISHED && (*state)->src_node != NULL && pf_src_connlimit(state)) { REASON_SET(reason, PFRES_SRCLIMIT); return (PF_DROP); } } else if (dst->state == TCPS_CLOSING) { dst->state = TCPS_FIN_WAIT_2; } else if (src->state == TCPS_SYN_SENT && dst->state < TCPS_SYN_SENT) { /* * Handle a special sloppy case where we only see one * half of the connection. If there is a ACK after * the initial SYN without ever seeing a packet from * the destination, set the connection to established. */ dst->state = src->state = TCPS_ESTABLISHED; if ((*state)->src_node != NULL && pf_src_connlimit(state)) { REASON_SET(reason, PFRES_SRCLIMIT); return (PF_DROP); } } else if (src->state == TCPS_CLOSING && dst->state == TCPS_ESTABLISHED && dst->seqlo == 0) { /* * Handle the closing of half connections where we * don't see the full bidirectional FIN/ACK+ACK * handshake. */ dst->state = TCPS_CLOSING; } } if (th->th_flags & TH_RST) src->state = dst->state = TCPS_TIME_WAIT; /* update expire time */ (*state)->expire = time_second; if (src->state >= TCPS_FIN_WAIT_2 && dst->state >= TCPS_FIN_WAIT_2) (*state)->timeout = PFTM_TCP_CLOSED; else if (src->state >= TCPS_CLOSING && dst->state >= TCPS_CLOSING) (*state)->timeout = PFTM_TCP_FIN_WAIT; else if (src->state < TCPS_ESTABLISHED || dst->state < TCPS_ESTABLISHED) (*state)->timeout = PFTM_TCP_OPENING; else if (src->state >= TCPS_CLOSING || dst->state >= TCPS_CLOSING) (*state)->timeout = PFTM_TCP_CLOSING; else (*state)->timeout = PFTM_TCP_ESTABLISHED; return (PF_PASS); } int pf_test_state_tcp(struct pf_state **state, int direction, struct pfi_kif *kif, struct mbuf *m, int off, void *h, struct pf_pdesc *pd, u_short *reason) { struct pf_state_key_cmp key; struct tcphdr *th = pd->hdr.tcp; int copyback = 0; struct pf_state_peer *src, *dst; struct pf_state_key *sk; key.af = pd->af; key.proto = IPPROTO_TCP; if (direction == PF_IN) { /* wire side, straight */ 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; } else { /* stack side, reverse */ PF_ACPY(&key.addr[1], pd->src, key.af); PF_ACPY(&key.addr[0], pd->dst, key.af); key.port[1] = th->th_sport; key.port[0] = th->th_dport; } STATE_LOOKUP(kif, &key, direction, *state, m); if (direction == (*state)->direction) { src = &(*state)->src; dst = &(*state)->dst; } else { src = &(*state)->dst; dst = &(*state)->src; } sk = (*state)->key[pd->didx]; if ((*state)->src.state == PF_TCPS_PROXY_SRC) { if (direction != (*state)->direction) { REASON_SET(reason, PFRES_SYNPROXY); return (PF_SYNPROXY_DROP); } if (th->th_flags & TH_SYN) { if (ntohl(th->th_seq) != (*state)->src.seqlo) { REASON_SET(reason, PFRES_SYNPROXY); return (PF_DROP); } pf_send_tcp((*state)->rule.ptr, pd->af, pd->dst, pd->src, th->th_dport, th->th_sport, (*state)->src.seqhi, ntohl(th->th_seq) + 1, TH_SYN|TH_ACK, 0, (*state)->src.mss, 0, 1, 0, NULL, NULL, (*state)->rtableid); REASON_SET(reason, PFRES_SYNPROXY); return (PF_SYNPROXY_DROP); } else if (!(th->th_flags & TH_ACK) || (ntohl(th->th_ack) != (*state)->src.seqhi + 1) || (ntohl(th->th_seq) != (*state)->src.seqlo + 1)) { REASON_SET(reason, PFRES_SYNPROXY); return (PF_DROP); } else if ((*state)->src_node != NULL && pf_src_connlimit(state)) { REASON_SET(reason, PFRES_SRCLIMIT); return (PF_DROP); } else (*state)->src.state = PF_TCPS_PROXY_DST; } if ((*state)->src.state == PF_TCPS_PROXY_DST) { if (direction == (*state)->direction) { if (((th->th_flags & (TH_SYN|TH_ACK)) != TH_ACK) || (ntohl(th->th_ack) != (*state)->src.seqhi + 1) || (ntohl(th->th_seq) != (*state)->src.seqlo + 1)) { REASON_SET(reason, PFRES_SYNPROXY); return (PF_DROP); } (*state)->src.max_win = MAX(ntohs(th->th_win), 1); if ((*state)->dst.seqhi == 1) (*state)->dst.seqhi = htonl(arc4random()); pf_send_tcp((*state)->rule.ptr, pd->af, &sk->addr[pd->sidx], &sk->addr[pd->didx], sk->port[pd->sidx], sk->port[pd->didx], (*state)->dst.seqhi, 0, TH_SYN, 0, (*state)->src.mss, 0, 0, (*state)->tag, NULL, NULL, (*state)->rtableid); REASON_SET(reason, PFRES_SYNPROXY); return (PF_SYNPROXY_DROP); } else if (((th->th_flags & (TH_SYN|TH_ACK)) != (TH_SYN|TH_ACK)) || (ntohl(th->th_ack) != (*state)->dst.seqhi + 1)) { REASON_SET(reason, PFRES_SYNPROXY); return (PF_DROP); } else { (*state)->dst.max_win = MAX(ntohs(th->th_win), 1); (*state)->dst.seqlo = ntohl(th->th_seq); pf_send_tcp((*state)->rule.ptr, pd->af, pd->dst, pd->src, th->th_dport, th->th_sport, ntohl(th->th_ack), ntohl(th->th_seq) + 1, TH_ACK, (*state)->src.max_win, 0, 0, 0, (*state)->tag, NULL, NULL, (*state)->rtableid); pf_send_tcp((*state)->rule.ptr, pd->af, &sk->addr[pd->sidx], &sk->addr[pd->didx], sk->port[pd->sidx], sk->port[pd->didx], (*state)->src.seqhi + 1, (*state)->src.seqlo + 1, TH_ACK, (*state)->dst.max_win, 0, 0, 1, 0, NULL, NULL, (*state)->rtableid); (*state)->src.seqdiff = (*state)->dst.seqhi - (*state)->src.seqlo; (*state)->dst.seqdiff = (*state)->src.seqhi - (*state)->dst.seqlo; (*state)->src.seqhi = (*state)->src.seqlo + (*state)->dst.max_win; (*state)->dst.seqhi = (*state)->dst.seqlo + (*state)->src.max_win; (*state)->src.wscale = (*state)->dst.wscale = 0; (*state)->src.state = (*state)->dst.state = TCPS_ESTABLISHED; REASON_SET(reason, PFRES_SYNPROXY); return (PF_SYNPROXY_DROP); } } if (((th->th_flags & (TH_SYN|TH_ACK)) == TH_SYN) && dst->state >= TCPS_FIN_WAIT_2 && src->state >= TCPS_FIN_WAIT_2) { if (pf_status.debug >= PF_DEBUG_MISC) { printf("pf: state reuse "); pf_print_state(*state); pf_print_flags(th->th_flags); printf("\n"); } /* XXX make sure it's the same direction ?? */ (*state)->src.state = (*state)->dst.state = TCPS_CLOSED; pf_unlink_state(*state); *state = NULL; return (PF_DROP); } if ((*state)->state_flags & PFSTATE_SLOPPY) { if (pf_tcp_track_sloppy(src, dst, state, pd, reason) == PF_DROP) return (PF_DROP); } else { if (pf_tcp_track_full(src, dst, state, kif, m, off, pd, reason, ©back) == PF_DROP) return (PF_DROP); } /* translate source/destination address, if necessary */ if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) { struct pf_state_key *nk = (*state)->key[pd->didx]; if (PF_ANEQ(pd->src, &nk->addr[pd->sidx], pd->af) || nk->port[pd->sidx] != th->th_sport) pf_change_ap(pd->src, &th->th_sport, pd->ip_sum, &th->th_sum, &nk->addr[pd->sidx], nk->port[pd->sidx], 0, pd->af); if (PF_ANEQ(pd->dst, &nk->addr[pd->didx], pd->af) || nk->port[pd->didx] != th->th_dport) pf_change_ap(pd->dst, &th->th_dport, pd->ip_sum, &th->th_sum, &nk->addr[pd->didx], nk->port[pd->didx], 0, pd->af); copyback = 1; } /* Copyback sequence modulation or stateful scrub changes if needed */ if (copyback) m_copyback(m, off, sizeof(*th), th); return (PF_PASS); } int pf_test_state_udp(struct pf_state **state, int direction, struct pfi_kif *kif, struct mbuf *m, int off, void *h, struct pf_pdesc *pd) { struct pf_state_peer *src, *dst; struct pf_state_key_cmp key; struct udphdr *uh = pd->hdr.udp; key.af = pd->af; key.proto = IPPROTO_UDP; if (direction == PF_IN) { /* wire side, straight */ PF_ACPY(&key.addr[0], pd->src, key.af); PF_ACPY(&key.addr[1], pd->dst, key.af); key.port[0] = uh->uh_sport; key.port[1] = uh->uh_dport; } else { /* stack side, reverse */ PF_ACPY(&key.addr[1], pd->src, key.af); PF_ACPY(&key.addr[0], pd->dst, key.af); key.port[1] = uh->uh_sport; key.port[0] = uh->uh_dport; } STATE_LOOKUP(kif, &key, direction, *state, m); if (direction == (*state)->direction) { src = &(*state)->src; dst = &(*state)->dst; } else { src = &(*state)->dst; dst = &(*state)->src; } /* update states */ if (src->state < PFUDPS_SINGLE) src->state = PFUDPS_SINGLE; if (dst->state == PFUDPS_SINGLE) dst->state = PFUDPS_MULTIPLE; /* update expire time */ (*state)->expire = time_second; if (src->state == PFUDPS_MULTIPLE && dst->state == PFUDPS_MULTIPLE) (*state)->timeout = PFTM_UDP_MULTIPLE; else (*state)->timeout = PFTM_UDP_SINGLE; /* translate source/destination address, if necessary */ if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) { struct pf_state_key *nk = (*state)->key[pd->didx]; if (PF_ANEQ(pd->src, &nk->addr[pd->sidx], pd->af) || nk->port[pd->sidx] != uh->uh_sport) pf_change_ap(pd->src, &uh->uh_sport, pd->ip_sum, &uh->uh_sum, &nk->addr[pd->sidx], nk->port[pd->sidx], 1, pd->af); if (PF_ANEQ(pd->dst, &nk->addr[pd->didx], pd->af) || nk->port[pd->didx] != uh->uh_dport) pf_change_ap(pd->dst, &uh->uh_dport, pd->ip_sum, &uh->uh_sum, &nk->addr[pd->didx], nk->port[pd->didx], 1, pd->af); m_copyback(m, off, sizeof(*uh), uh); } return (PF_PASS); } int pf_icmp_state_lookup(struct pf_state_key_cmp *key, struct pf_pdesc *pd, struct pf_state **state, struct mbuf *m, int direction, struct pfi_kif *kif, u_int16_t icmpid, u_int16_t type, int icmp_dir, int *iidx, int multi) { key->af = pd->af; key->proto = pd->proto; if (icmp_dir == PF_IN) { *iidx = pd->sidx; key->port[pd->sidx] = icmpid; key->port[pd->didx] = type; } else { *iidx = pd->didx; key->port[pd->sidx] = type; key->port[pd->didx] = icmpid; } if (pd->af == AF_INET6 && multi != PF_ICMP_MULTI_NONE) { switch (multi) { case PF_ICMP_MULTI_SOLICITED: key->addr[pd->sidx].addr32[0] = IPV6_ADDR_INT32_MLL; key->addr[pd->sidx].addr32[1] = 0; key->addr[pd->sidx].addr32[2] = IPV6_ADDR_INT32_ONE; key->addr[pd->sidx].addr32[3] = pd->src->addr32[3]; key->addr[pd->sidx].addr8[12] = 0xff; break; case PF_ICMP_MULTI_LINK: key->addr[pd->sidx].addr32[0] = IPV6_ADDR_INT32_MLL; key->addr[pd->sidx].addr32[1] = 0; key->addr[pd->sidx].addr32[2] = 0; key->addr[pd->sidx].addr32[3] = IPV6_ADDR_INT32_ONE; break; } } else PF_ACPY(&key->addr[pd->sidx], pd->src, key->af); PF_ACPY(&key->addr[pd->didx], pd->dst, key->af); STATE_LOOKUP(kif, key, direction, *state, m); /* Is this ICMP message flowing in right direction? */ if ((*state)->rule.ptr->type && (((*state)->direction == direction) ? PF_IN : PF_OUT) != icmp_dir) { if (pf_status.debug >= PF_DEBUG_MISC) { printf("pf: icmp type %d in wrong direction (%d): ", ntohs(type), icmp_dir); pf_print_state(*state); printf("\n"); } return (PF_DROP); } return (-1); } int pf_test_state_icmp(struct pf_state **state, int direction, struct pfi_kif *kif, struct mbuf *m, int off, void *h, struct pf_pdesc *pd, u_short *reason) { struct pf_addr *saddr = pd->src, *daddr = pd->dst; u_int16_t icmpid, *icmpsum, virtual_id, virtual_type; u_int8_t icmptype; int icmp_dir, iidx, ret, multi; struct pf_state_key_cmp key; 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; 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; break; #endif /* INET6 */ } if (pf_icmp_mapping(pd, icmptype, &icmp_dir, &multi, &virtual_id, &virtual_type) == 0) { /* * ICMP query/reply message not related to a TCP/UDP packet. * Search for an ICMP state. */ ret = pf_icmp_state_lookup(&key, pd, state, m, direction, kif, virtual_id, virtual_type, icmp_dir, &iidx, PF_ICMP_MULTI_NONE); if (ret >= 0) { if (ret == PF_DROP && pd->af == AF_INET6 && icmp_dir == PF_OUT) { ret = pf_icmp_state_lookup(&key, pd, state, m, direction, kif, virtual_id, virtual_type, icmp_dir, &iidx, multi); if (ret >= 0) return (ret); } else return (ret); } (*state)->expire = time_second; (*state)->timeout = PFTM_ICMP_ERROR_REPLY; /* translate source/destination address, if necessary */ if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) { struct pf_state_key *nk = (*state)->key[pd->didx]; switch (pd->af) { #ifdef INET case AF_INET: if (PF_ANEQ(pd->src, &nk->addr[pd->sidx], AF_INET)) pf_change_a(&saddr->v4.s_addr, pd->ip_sum, nk->addr[pd->sidx].v4.s_addr, 0); if (PF_ANEQ(pd->dst, &nk->addr[pd->didx], AF_INET)) pf_change_a(&daddr->v4.s_addr, pd->ip_sum, nk->addr[pd->didx].v4.s_addr, 0); if (nk->port[iidx] != pd->hdr.icmp->icmp_id) { pd->hdr.icmp->icmp_cksum = pf_cksum_fixup( pd->hdr.icmp->icmp_cksum, icmpid, nk->port[iidx], 0); pd->hdr.icmp->icmp_id = nk->port[iidx]; } m_copyback(m, off, ICMP_MINLEN, pd->hdr.icmp); break; #endif /* INET */ #ifdef INET6 case AF_INET6: if (PF_ANEQ(pd->src, &nk->addr[pd->sidx], AF_INET6)) pf_change_a6(saddr, &pd->hdr.icmp6->icmp6_cksum, &nk->addr[pd->sidx], 0); if (PF_ANEQ(pd->dst, &nk->addr[pd->didx], AF_INET6)) pf_change_a6(daddr, &pd->hdr.icmp6->icmp6_cksum, &nk->addr[pd->didx], 0); m_copyback(m, off, sizeof(struct icmp6_hdr), 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; /* Payload packet is from the opposite direction. */ pd2.sidx = (direction == PF_IN) ? 1 : 0; pd2.didx = (direction == PF_IN) ? 0 : 1; 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, reason, 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 (h2.ip_off & htons(IP_OFFMASK)) { REASON_SET(reason, PFRES_FRAG); 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, reason, 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 */ REASON_SET(reason, PFRES_FRAG); 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, reason, 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_state_peer *src, *dst; u_int8_t dws; int copyback = 0; /* * 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, reason, 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[pd2.sidx], pd2.src, key.af); PF_ACPY(&key.addr[pd2.didx], pd2.dst, key.af); key.port[pd2.sidx] = th.th_sport; key.port[pd2.didx] = th.th_dport; STATE_LOOKUP(kif, &key, direction, *state, m); if (direction == (*state)->direction) { src = &(*state)->dst; dst = &(*state)->src; } else { src = &(*state)->src; dst = &(*state)->dst; } if (src->wscale && dst->wscale) dws = dst->wscale & PF_WSCALE_MASK; else dws = 0; /* Demodulate sequence number */ seq = ntohl(th.th_seq) - src->seqdiff; if (src->seqdiff) { pf_change_a(&th.th_seq, icmpsum, htonl(seq), 0); copyback = 1; } if (!((*state)->state_flags & PFSTATE_SLOPPY) && (!SEQ_GEQ(src->seqhi, seq) || !SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)))) { if (pf_status.debug >= PF_DEBUG_MISC) { printf("pf: BAD ICMP %d:%d ", icmptype, pd->hdr.icmp->icmp_code); pf_print_host(pd->src, 0, pd->af); printf(" -> "); pf_print_host(pd->dst, 0, pd->af); printf(" state: "); pf_print_state(*state); printf(" seq=%u\n", seq); } REASON_SET(reason, PFRES_BADSTATE); return (PF_DROP); } else { if (pf_status.debug >= PF_DEBUG_NOISY) { printf("pf: OK ICMP %d:%d ", icmptype, pd->hdr.icmp->icmp_code); pf_print_host(pd->src, 0, pd->af); printf(" -> "); pf_print_host(pd->dst, 0, pd->af); printf(" state: "); pf_print_state(*state); printf(" seq=%u\n", seq); } } /* translate source/destination address, if necessary */ if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) { struct pf_state_key *nk = (*state)->key[pd->didx]; if (PF_ANEQ(pd2.src, &nk->addr[pd2.sidx], pd2.af) || nk->port[pd2.sidx] != th.th_sport) pf_change_icmp(pd2.src, &th.th_sport, daddr, &nk->addr[pd2.sidx], nk->port[pd2.sidx], NULL, pd2.ip_sum, icmpsum, pd->ip_sum, 0, pd2.af); if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], pd2.af) || nk->port[pd2.didx] != th.th_dport) pf_change_icmp(pd2.dst, &th.th_dport, NULL, /* XXX Inbound NAT? */ &nk->addr[pd2.didx], nk->port[pd2.didx], NULL, pd2.ip_sum, icmpsum, pd->ip_sum, 0, pd2.af); copyback = 1; } if (copyback) { switch (pd2.af) { #ifdef INET case AF_INET: m_copyback(m, off, ICMP_MINLEN, pd->hdr.icmp); m_copyback(m, ipoff2, sizeof(h2), &h2); break; #endif /* INET */ #ifdef INET6 case AF_INET6: m_copyback(m, off, sizeof(struct icmp6_hdr), pd->hdr.icmp6); m_copyback(m, ipoff2, sizeof(h2_6), &h2_6); break; #endif /* INET6 */ } m_copyback(m, off2, 8, &th); } return (PF_PASS); break; } case IPPROTO_UDP: { struct udphdr uh; if (!pf_pull_hdr(m, off2, &uh, sizeof(uh), NULL, reason, 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[pd2.sidx], pd2.src, key.af); PF_ACPY(&key.addr[pd2.didx], pd2.dst, key.af); key.port[pd2.sidx] = uh.uh_sport; key.port[pd2.didx] = uh.uh_dport; STATE_LOOKUP(kif, &key, direction, *state, m); /* translate source/destination address, if necessary */ if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) { struct pf_state_key *nk = (*state)->key[pd->didx]; if (PF_ANEQ(pd2.src, &nk->addr[pd2.sidx], pd2.af) || nk->port[pd2.sidx] != uh.uh_sport) pf_change_icmp(pd2.src, &uh.uh_sport, daddr, &nk->addr[pd2.sidx], nk->port[pd2.sidx], &uh.uh_sum, pd2.ip_sum, icmpsum, pd->ip_sum, 1, pd2.af); if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], pd2.af) || nk->port[pd2.didx] != uh.uh_dport) pf_change_icmp(pd2.dst, &uh.uh_dport, NULL, /* XXX Inbound NAT? */ &nk->addr[pd2.didx], nk->port[pd2.didx], &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, pd->hdr.icmp); m_copyback(m, ipoff2, sizeof(h2), &h2); break; #endif /* INET */ #ifdef INET6 case AF_INET6: m_copyback(m, off, sizeof(struct icmp6_hdr), pd->hdr.icmp6); m_copyback(m, ipoff2, sizeof(h2_6), &h2_6); break; #endif /* INET6 */ } m_copyback(m, off2, sizeof(uh), &uh); } return (PF_PASS); break; } #ifdef INET case IPPROTO_ICMP: { struct icmp iih; if (!pf_pull_hdr(m, off2, &iih, ICMP_MINLEN, NULL, reason, pd2.af)) { DPFPRINTF(PF_DEBUG_MISC, ("pf: ICMP error message too short i" "(icmp)\n")); return (PF_DROP); } pd2.hdr.icmp = &iih; pf_icmp_mapping(&pd2, iih.icmp_type, &icmp_dir, &multi, &virtual_id, &virtual_type); ret = pf_icmp_state_lookup(&key, &pd2, state, m, direction, kif, virtual_id, virtual_type, icmp_dir, &iidx, PF_ICMP_MULTI_NONE); if (ret >= 0) return (ret); /* translate source/destination address, if necessary */ if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) { struct pf_state_key *nk = (*state)->key[pd->didx]; if (PF_ANEQ(pd2.src, &nk->addr[pd2.sidx], pd2.af) || (virtual_type == ICMP_ECHO && nk->port[iidx] != iih.icmp_id)) pf_change_icmp(pd2.src, (virtual_type == ICMP_ECHO) ? &iih.icmp_id : NULL, daddr, &nk->addr[pd2.sidx], (virtual_type == ICMP_ECHO) ? nk->port[iidx] : NULL, NULL, pd2.ip_sum, icmpsum, pd->ip_sum, 0, AF_INET); if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], pd2.af)) pf_change_icmp(pd2.dst, NULL, NULL, &nk->addr[pd2.didx], 0, NULL, pd2.ip_sum, icmpsum, pd->ip_sum, 0, AF_INET); m_copyback(m, off, ICMP_MINLEN, pd->hdr.icmp); m_copyback(m, ipoff2, sizeof(h2), &h2); m_copyback(m, off2, ICMP_MINLEN, &iih); } return (PF_PASS); break; } #endif /* INET */ #ifdef INET6 case IPPROTO_ICMPV6: { struct icmp6_hdr iih; if (!pf_pull_hdr(m, off2, &iih, sizeof(struct icmp6_hdr), NULL, reason, pd2.af)) { DPFPRINTF(PF_DEBUG_MISC, ("pf: ICMP error message too short " "(icmp6)\n")); return (PF_DROP); } pd2.hdr.icmp6 = &iih; pf_icmp_mapping(&pd2, iih.icmp6_type, &icmp_dir, &multi, &virtual_id, &virtual_type); ret = pf_icmp_state_lookup(&key, &pd2, state, m, direction, kif, virtual_id, virtual_type, icmp_dir, &iidx, PF_ICMP_MULTI_NONE); if (ret >= 0) { if (ret == PF_DROP && pd->af == AF_INET6 && icmp_dir == PF_OUT) { ret = pf_icmp_state_lookup(&key, pd, state, m, direction, kif, virtual_id, virtual_type, icmp_dir, &iidx, multi); if (ret >= 0) return (ret); } else return (ret); } /* translate source/destination address, if necessary */ if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) { struct pf_state_key *nk = (*state)->key[pd->didx]; if (PF_ANEQ(pd2.src, &nk->addr[pd2.sidx], pd2.af) || ((virtual_type == ICMP6_ECHO_REQUEST) && nk->port[pd2.sidx] != iih.icmp6_id)) pf_change_icmp(pd2.src, (virtual_type == ICMP6_ECHO_REQUEST) ? &iih.icmp6_id : NULL, daddr, &nk->addr[pd2.sidx], (virtual_type == ICMP6_ECHO_REQUEST) ? nk->port[iidx] : NULL, NULL, pd2.ip_sum, icmpsum, pd->ip_sum, 0, AF_INET6); if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], pd2.af)) pf_change_icmp(pd2.dst, NULL, NULL, &nk->addr[pd2.didx], 0, NULL, pd2.ip_sum, icmpsum, pd->ip_sum, 0, AF_INET6); m_copyback(m, off, sizeof(struct icmp6_hdr), pd->hdr.icmp6); m_copyback(m, ipoff2, sizeof(h2_6), &h2_6); m_copyback(m, off2, sizeof(struct icmp6_hdr), &iih); } return (PF_PASS); break; } #endif /* INET6 */ default: { key.af = pd2.af; key.proto = pd2.proto; PF_ACPY(&key.addr[pd2.sidx], pd2.src, key.af); PF_ACPY(&key.addr[pd2.didx], pd2.dst, key.af); key.port[0] = key.port[1] = 0; STATE_LOOKUP(kif, &key, direction, *state, m); /* translate source/destination address, if necessary */ if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) { struct pf_state_key *nk = (*state)->key[pd->didx]; if (PF_ANEQ(pd2.src, &nk->addr[pd2.sidx], pd2.af)) pf_change_icmp(pd2.src, NULL, daddr, &nk->addr[pd2.sidx], 0, NULL, pd2.ip_sum, icmpsum, pd->ip_sum, 0, pd2.af); if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], pd2.af)) pf_change_icmp(pd2.src, NULL, NULL, /* XXX Inbound NAT? */ &nk->addr[pd2.didx], 0, 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, pd->hdr.icmp); m_copyback(m, ipoff2, sizeof(h2), &h2); break; #endif /* INET */ #ifdef INET6 case AF_INET6: m_copyback(m, off, sizeof(struct icmp6_hdr), pd->hdr.icmp6); m_copyback(m, ipoff2, sizeof(h2_6), &h2_6); break; #endif /* INET6 */ } } return (PF_PASS); break; } } } } int pf_test_state_other(struct pf_state **state, int direction, struct pfi_kif *kif, struct mbuf *m, struct pf_pdesc *pd) { struct pf_state_peer *src, *dst; struct pf_state_key_cmp key; key.af = pd->af; key.proto = pd->proto; if (direction == PF_IN) { PF_ACPY(&key.addr[0], pd->src, key.af); PF_ACPY(&key.addr[1], pd->dst, key.af); key.port[0] = key.port[1] = 0; } else { PF_ACPY(&key.addr[1], pd->src, key.af); PF_ACPY(&key.addr[0], pd->dst, key.af); key.port[1] = key.port[0] = 0; } STATE_LOOKUP(kif, &key, direction, *state, m); if (direction == (*state)->direction) { src = &(*state)->src; dst = &(*state)->dst; } else { src = &(*state)->dst; dst = &(*state)->src; } /* update states */ if (src->state < PFOTHERS_SINGLE) src->state = PFOTHERS_SINGLE; if (dst->state == PFOTHERS_SINGLE) dst->state = PFOTHERS_MULTIPLE; /* update expire time */ (*state)->expire = time_second; if (src->state == PFOTHERS_MULTIPLE && dst->state == PFOTHERS_MULTIPLE) (*state)->timeout = PFTM_OTHER_MULTIPLE; else (*state)->timeout = PFTM_OTHER_SINGLE; /* translate source/destination address, if necessary */ if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) { struct pf_state_key *nk = (*state)->key[pd->didx]; KASSERT(nk); KASSERT(pd); KASSERT(pd->src); KASSERT(pd->dst); switch (pd->af) { #ifdef INET case AF_INET: if (PF_ANEQ(pd->src, &nk->addr[pd->sidx], AF_INET)) pf_change_a(&pd->src->v4.s_addr, pd->ip_sum, nk->addr[pd->sidx].v4.s_addr, 0); if (PF_ANEQ(pd->dst, &nk->addr[pd->didx], AF_INET)) pf_change_a(&pd->dst->v4.s_addr, pd->ip_sum, nk->addr[pd->didx].v4.s_addr, 0); break; #endif /* INET */ #ifdef INET6 case AF_INET6: if (PF_ANEQ(pd->src, &nk->addr[pd->sidx], AF_INET)) PF_ACPY(pd->src, &nk->addr[pd->sidx], pd->af); if (PF_ANEQ(pd->dst, &nk->addr[pd->didx], AF_INET)) PF_ACPY(pd->dst, &nk->addr[pd->didx], pd->af); #endif /* INET6 */ } } return (PF_PASS); } /* * ipoff and off are measured from the start of the mbuf chain. * h must be at "ipoff" on the mbuf chain. */ void * pf_pull_hdr(struct mbuf *m, int off, void *p, int len, u_short *actionp, u_short *reasonp, sa_family_t af) { switch (af) { #ifdef INET case AF_INET: { struct ip *h = mtod(m, struct ip *); u_int16_t fragoff = (ntohs(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 || ntohs(h->ip_len) < off + len) { ACTION_SET(actionp, PF_DROP); REASON_SET(reasonp, PFRES_SHORT); return (NULL); } break; } #endif /* INET */ #ifdef INET6 case AF_INET6: { struct ip6_hdr *h = mtod(m, struct ip6_hdr *); if (m->m_pkthdr.len < off + len || (ntohs(h->ip6_plen) + sizeof(struct ip6_hdr)) < (unsigned)(off + len)) { ACTION_SET(actionp, PF_DROP); REASON_SET(reasonp, PFRES_SHORT); return (NULL); } break; } #endif /* INET6 */ } m_copydata(m, off, len, p); return (p); } int pf_routable(struct pf_addr *addr, sa_family_t af, struct pfi_kif *kif) { struct sockaddr_in *dst; int ret = 1; int check_mpath; extern int ipmultipath; #ifdef INET6 extern int ip6_multipath; struct sockaddr_in6 *dst6; struct route_in6 ro; #else struct route ro; #endif struct radix_node *rn; struct rtentry *rt; struct ifnet *ifp; check_mpath = 0; bzero(&ro, sizeof(ro)); switch (af) { case AF_INET: dst = satosin(&ro.ro_dst); dst->sin_family = AF_INET; dst->sin_len = sizeof(*dst); dst->sin_addr = addr->v4; if (ipmultipath) check_mpath = 1; break; #ifdef INET6 case AF_INET6: /* * Skip check for addresses with embedded interface scope, * as they would always match anyway. */ if (IN6_IS_SCOPE_EMBED(&addr->v6)) goto out; dst6 = (struct sockaddr_in6 *)&ro.ro_dst; dst6->sin6_family = AF_INET6; dst6->sin6_len = sizeof(*dst6); dst6->sin6_addr = addr->v6; if (ip6_multipath) check_mpath = 1; break; #endif /* INET6 */ default: return (0); } /* Skip checks for ipsec interfaces */ if (kif != NULL && kif->pfik_ifp->if_type == IFT_ENC) goto out; rtalloc_noclone((struct route *)&ro, NO_CLONING); if (ro.ro_rt != NULL) { /* No interface given, this is a no-route check */ if (kif == NULL) goto out; if (kif->pfik_ifp == NULL) { ret = 0; goto out; } /* Perform uRPF check if passed input interface */ ret = 0; rn = (struct radix_node *)ro.ro_rt; do { rt = (struct rtentry *)rn; if (rt->rt_ifp->if_type == IFT_CARP) ifp = rt->rt_ifp->if_carpdev; else ifp = rt->rt_ifp; if (kif->pfik_ifp == ifp) ret = 1; rn = rn_mpath_next(rn, 0); } while (check_mpath == 1 && rn != NULL && ret == 0); } else ret = 0; out: if (ro.ro_rt != NULL) RTFREE(ro.ro_rt); return (ret); } int pf_rtlabel_match(struct pf_addr *addr, sa_family_t af, struct pf_addr_wrap *aw) { struct sockaddr_in *dst; #ifdef INET6 struct sockaddr_in6 *dst6; struct route_in6 ro; #else struct route ro; #endif int ret = 0; bzero(&ro, sizeof(ro)); switch (af) { case AF_INET: dst = satosin(&ro.ro_dst); dst->sin_family = AF_INET; dst->sin_len = sizeof(*dst); dst->sin_addr = addr->v4; break; #ifdef INET6 case AF_INET6: dst6 = (struct sockaddr_in6 *)&ro.ro_dst; dst6->sin6_family = AF_INET6; dst6->sin6_len = sizeof(*dst6); dst6->sin6_addr = addr->v6; break; #endif /* INET6 */ default: return (0); } rtalloc_noclone((struct route *)&ro, NO_CLONING); if (ro.ro_rt != NULL) { if (ro.ro_rt->rt_labelid == aw->v.rtlabel) ret = 1; RTFREE(ro.ro_rt); } return (ret); } #ifdef INET void pf_route(struct mbuf **m, struct pf_rule *r, int dir, struct ifnet *oifp, struct pf_state *s, struct pf_pdesc *pd) { struct mbuf *m0, *m1; struct route iproute; struct route *ro = NULL; struct sockaddr_in *dst; struct ip *ip; struct ifnet *ifp = NULL; struct pf_addr naddr; struct pf_src_node *sn = NULL; int error = 0; #ifdef IPSEC struct m_tag *mtag; #endif /* IPSEC */ if (m == NULL || *m == NULL || r == NULL || (dir != PF_IN && dir != PF_OUT) || oifp == NULL) panic("pf_route: invalid parameters"); if ((*m)->m_pkthdr.pf.routed++ > 3) { m0 = *m; *m = NULL; goto bad; } if (r->rt == PF_DUPTO) { if ((m0 = m_copym2(*m, 0, M_COPYALL, M_NOWAIT)) == NULL) return; } else { if ((r->rt == PF_REPLYTO) == (r->direction == dir)) return; m0 = *m; } if (m0->m_len < sizeof(struct ip)) { DPFPRINTF(PF_DEBUG_URGENT, ("pf_route: m0->m_len < sizeof(struct ip)\n")); goto bad; } ip = mtod(m0, struct ip *); ro = &iproute; bzero((caddr_t)ro, sizeof(*ro)); dst = satosin(&ro->ro_dst); dst->sin_family = AF_INET; dst->sin_len = sizeof(*dst); dst->sin_addr = ip->ip_dst; if (r->rt == PF_FASTROUTE) { rtalloc(ro); if (ro->ro_rt == 0) { ipstat.ips_noroute++; goto bad; } ifp = ro->ro_rt->rt_ifp; ro->ro_rt->rt_use++; if (ro->ro_rt->rt_flags & RTF_GATEWAY) dst = satosin(ro->ro_rt->rt_gateway); } else { if (TAILQ_EMPTY(&r->rpool.list)) { DPFPRINTF(PF_DEBUG_URGENT, ("pf_route: TAILQ_EMPTY(&r->rpool.list)\n")); goto bad; } if (s == NULL) { pf_map_addr(AF_INET, r, (struct pf_addr *)&ip->ip_src, &naddr, NULL, &sn); if (!PF_AZERO(&naddr, AF_INET)) dst->sin_addr.s_addr = naddr.v4.s_addr; ifp = r->rpool.cur->kif ? r->rpool.cur->kif->pfik_ifp : NULL; } else { if (!PF_AZERO(&s->rt_addr, AF_INET)) dst->sin_addr.s_addr = s->rt_addr.v4.s_addr; ifp = s->rt_kif ? s->rt_kif->pfik_ifp : NULL; } } if (ifp == NULL) goto bad; if (oifp != ifp) { if (pf_test(PF_OUT, ifp, &m0, NULL) != PF_PASS) goto bad; else if (m0 == NULL) goto done; if (m0->m_len < sizeof(struct ip)) { DPFPRINTF(PF_DEBUG_URGENT, ("pf_route: m0->m_len < sizeof(struct ip)\n")); goto bad; } ip = mtod(m0, struct ip *); } /* Copied from ip_output. */ #ifdef IPSEC /* * If deferred crypto processing is needed, check that the * interface supports it. */ if ((mtag = m_tag_find(m0, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL)) != NULL && (ifp->if_capabilities & IFCAP_IPSEC) == 0) { /* Notify IPsec to do its own crypto. */ ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1)); goto bad; } #endif /* IPSEC */ /* Catch routing changes wrt. hardware checksumming for TCP or UDP. */ if (m0->m_pkthdr.csum_flags & M_TCPV4_CSUM_OUT) { if (!(ifp->if_capabilities & IFCAP_CSUM_TCPv4) || ifp->if_bridge != NULL) { in_delayed_cksum(m0); m0->m_pkthdr.csum_flags &= ~M_TCPV4_CSUM_OUT; /* Clr */ } } else if (m0->m_pkthdr.csum_flags & M_UDPV4_CSUM_OUT) { if (!(ifp->if_capabilities & IFCAP_CSUM_UDPv4) || ifp->if_bridge != NULL) { in_delayed_cksum(m0); m0->m_pkthdr.csum_flags &= ~M_UDPV4_CSUM_OUT; /* Clr */ } } if (ntohs(ip->ip_len) <= ifp->if_mtu) { ip->ip_sum = 0; if ((ifp->if_capabilities & IFCAP_CSUM_IPv4) && ifp->if_bridge == NULL) { m0->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; ipstat.ips_outhwcsum++; } else ip->ip_sum = in_cksum(m0, ip->ip_hl << 2); /* Update relevant hardware checksum stats for TCP/UDP */ if (m0->m_pkthdr.csum_flags & M_TCPV4_CSUM_OUT) tcpstat.tcps_outhwcsum++; else if (m0->m_pkthdr.csum_flags & 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 & htons(IP_DF)) { ipstat.ips_cantfrag++; if (r->rt != PF_DUPTO) { icmp_error(m0, ICMP_UNREACH, ICMP_UNREACH_NEEDFRAG, 0, ifp->if_mtu); goto done; } else goto bad; } m1 = m0; error = ip_fragment(m0, ifp, ifp->if_mtu); if (error) { m0 = NULL; goto bad; } for (m0 = m1; m0; m0 = m1) { m1 = m0->m_nextpkt; m0->m_nextpkt = 0; if (error == 0) error = (*ifp->if_output)(ifp, m0, sintosa(dst), NULL); else m_freem(m0); } if (error == 0) ipstat.ips_fragmented++; done: if (r->rt != PF_DUPTO) *m = NULL; if (ro == &iproute && ro->ro_rt) RTFREE(ro->ro_rt); return; bad: m_freem(m0); goto done; } #endif /* INET */ #ifdef INET6 void pf_route6(struct mbuf **m, struct pf_rule *r, int dir, struct ifnet *oifp, struct pf_state *s, struct pf_pdesc *pd) { struct mbuf *m0; struct route_in6 ip6route; struct route_in6 *ro; struct sockaddr_in6 *dst; struct ip6_hdr *ip6; struct ifnet *ifp = NULL; struct pf_addr naddr; struct pf_src_node *sn = NULL; if (m == NULL || *m == NULL || r == NULL || (dir != PF_IN && dir != PF_OUT) || oifp == NULL) panic("pf_route6: invalid parameters"); if ((*m)->m_pkthdr.pf.routed++ > 3) { m0 = *m; *m = NULL; goto bad; } if (r->rt == PF_DUPTO) { if ((m0 = m_copym2(*m, 0, M_COPYALL, M_NOWAIT)) == NULL) return; } else { if ((r->rt == PF_REPLYTO) == (r->direction == dir)) return; m0 = *m; } if (m0->m_len < sizeof(struct ip6_hdr)) { DPFPRINTF(PF_DEBUG_URGENT, ("pf_route6: m0->m_len < sizeof(struct ip6_hdr)\n")); goto bad; } ip6 = mtod(m0, struct ip6_hdr *); ro = &ip6route; bzero((caddr_t)ro, sizeof(*ro)); dst = (struct sockaddr_in6 *)&ro->ro_dst; dst->sin6_family = AF_INET6; dst->sin6_len = sizeof(*dst); dst->sin6_addr = ip6->ip6_dst; /* Cheat. XXX why only in the v6 case??? */ if (r->rt == PF_FASTROUTE) { m0->m_pkthdr.pf.flags |= PF_TAG_GENERATED; ip6_output(m0, NULL, NULL, 0, NULL, NULL, NULL); return; } if (TAILQ_EMPTY(&r->rpool.list)) { DPFPRINTF(PF_DEBUG_URGENT, ("pf_route6: TAILQ_EMPTY(&r->rpool.list)\n")); goto bad; } if (s == NULL) { pf_map_addr(AF_INET6, r, (struct pf_addr *)&ip6->ip6_src, &naddr, NULL, &sn); if (!PF_AZERO(&naddr, AF_INET6)) PF_ACPY((struct pf_addr *)&dst->sin6_addr, &naddr, AF_INET6); ifp = r->rpool.cur->kif ? r->rpool.cur->kif->pfik_ifp : NULL; } else { if (!PF_AZERO(&s->rt_addr, AF_INET6)) PF_ACPY((struct pf_addr *)&dst->sin6_addr, &s->rt_addr, AF_INET6); ifp = s->rt_kif ? s->rt_kif->pfik_ifp : NULL; } if (ifp == NULL) goto bad; if (oifp != ifp) { if (pf_test6(PF_OUT, ifp, &m0, NULL) != PF_PASS) goto bad; else if (m0 == NULL) goto done; if (m0->m_len < sizeof(struct ip6_hdr)) { DPFPRINTF(PF_DEBUG_URGENT, ("pf_route6: m0->m_len < sizeof(struct ip6_hdr)\n")); goto bad; } ip6 = mtod(m0, struct ip6_hdr *); } /* * If the packet is too large for the outgoing interface, * send back an icmp6 error. */ if (IN6_IS_SCOPE_EMBED(&dst->sin6_addr)) dst->sin6_addr.s6_addr16[1] = htons(ifp->if_index); if ((u_long)m0->m_pkthdr.len <= ifp->if_mtu) { nd6_output(ifp, ifp, m0, dst, NULL); } else { in6_ifstat_inc(ifp, ifs6_in_toobig); if (r->rt != PF_DUPTO) icmp6_error(m0, ICMP6_PACKET_TOO_BIG, 0, ifp->if_mtu); else goto bad; } done: if (r->rt != PF_DUPTO) *m = NULL; return; bad: m_freem(m0); goto done; } #endif /* INET6 */ /* * check protocol (tcp/udp/icmp/icmp6) checksum and set mbuf flag * off is the offset where the protocol header starts * len is the total length of protocol header plus payload * returns 0 when the checksum is valid, otherwise returns 1. */ int pf_check_proto_cksum(struct mbuf *m, int off, int len, u_int8_t p, sa_family_t af) { u_int16_t flag_ok, flag_bad; u_int16_t sum; switch (p) { case IPPROTO_TCP: flag_ok = M_TCP_CSUM_IN_OK; flag_bad = M_TCP_CSUM_IN_BAD; break; case IPPROTO_UDP: flag_ok = M_UDP_CSUM_IN_OK; flag_bad = M_UDP_CSUM_IN_BAD; break; case IPPROTO_ICMP: #ifdef INET6 case IPPROTO_ICMPV6: #endif /* INET6 */ flag_ok = flag_bad = 0; break; default: return (1); } if (m->m_pkthdr.csum_flags & flag_ok) return (0); if (m->m_pkthdr.csum_flags & flag_bad) return (1); if (off < sizeof(struct ip) || len < sizeof(struct udphdr)) return (1); if (m->m_pkthdr.len < off + len) return (1); switch (af) { #ifdef INET case AF_INET: if (p == IPPROTO_ICMP) { if (m->m_len < off) return (1); m->m_data += off; m->m_len -= off; sum = in_cksum(m, len); m->m_data -= off; m->m_len += off; } else { if (m->m_len < sizeof(struct ip)) return (1); sum = in4_cksum(m, p, off, len); } break; #endif /* INET */ #ifdef INET6 case AF_INET6: if (m->m_len < sizeof(struct ip6_hdr)) return (1); sum = in6_cksum(m, p, off, len); break; #endif /* INET6 */ default: return (1); } if (sum) { m->m_pkthdr.csum_flags |= flag_bad; switch (p) { case IPPROTO_TCP: tcpstat.tcps_rcvbadsum++; break; case IPPROTO_UDP: udpstat.udps_badsum++; break; case IPPROTO_ICMP: icmpstat.icps_checksum++; break; #ifdef INET6 case IPPROTO_ICMPV6: icmp6stat.icp6s_checksum++; break; #endif /* INET6 */ } return (1); } m->m_pkthdr.csum_flags |= flag_ok; return (0); } struct pf_divert * pf_find_divert(struct mbuf *m) { struct m_tag *mtag; if ((mtag = m_tag_find(m, PACKET_TAG_PF_DIVERT, NULL)) == NULL) return (NULL); return ((struct pf_divert *)(mtag + 1)); } struct pf_divert * pf_get_divert(struct mbuf *m) { struct m_tag *mtag; if ((mtag = m_tag_find(m, PACKET_TAG_PF_DIVERT, NULL)) == NULL) { mtag = m_tag_get(PACKET_TAG_PF_DIVERT, sizeof(struct pf_divert), M_NOWAIT); if (mtag == NULL) return (NULL); bzero(mtag + 1, sizeof(struct pf_divert)); m_tag_prepend(m, mtag); } return ((struct pf_divert *)(mtag + 1)); } #ifdef INET int pf_test(int dir, struct ifnet *ifp, struct mbuf **m0, struct ether_header *eh) { struct pfi_kif *kif; u_short action, reason = 0, log = 0; struct mbuf *m = *m0; struct ip *h; struct pf_rule *a = NULL, *r = &pf_default_rule, *tr, *nr; struct pf_state *s = NULL; struct pf_ruleset *ruleset = NULL; struct pf_pdesc pd; int off, dirndx, pqid = 0; u_int16_t qid; if (!pf_status.running) return (PF_PASS); memset(&pd, 0, sizeof(pd)); if (ifp->if_type == IFT_CARP && ifp->if_carpdev) kif = (struct pfi_kif *)ifp->if_carpdev->if_pf_kif; else kif = (struct pfi_kif *)ifp->if_pf_kif; if (kif == NULL) { DPFPRINTF(PF_DEBUG_URGENT, ("pf_test: kif == NULL, if_xname %s\n", ifp->if_xname)); return (PF_DROP); } if (kif->pfik_flags & PFI_IFLAG_SKIP) return (PF_PASS); #ifdef DIAGNOSTIC if ((m->m_flags & M_PKTHDR) == 0) panic("non-M_PKTHDR is passed to pf_test"); #endif /* DIAGNOSTIC */ if (m->m_pkthdr.len < (int)sizeof(*h)) { action = PF_DROP; REASON_SET(&reason, PFRES_SHORT); log |= PF_LOG_FORCE; goto done; } if (m->m_pkthdr.pf.flags & PF_TAG_GENERATED) return (PF_PASS); /* packet reassembly here if 1) enabled 2) we deal with a fragment */ h = mtod(m, struct ip *); if (pf_status.reass && (h->ip_off & htons(IP_MF | IP_OFFMASK)) && pf_normalize_ip(m0, dir, kif, &reason, &pd) != PF_PASS) { action = PF_DROP; goto done; } m = *m0; /* pf_normalize messes with m0 */ h = mtod(m, struct ip *); off = h->ip_hl << 2; if (off < (int)sizeof(*h)) { action = PF_DROP; REASON_SET(&reason, PFRES_SHORT); log |= PF_LOG_FORCE; goto done; } pd.src = (struct pf_addr *)&h->ip_src; pd.dst = (struct pf_addr *)&h->ip_dst; pd.sport = pd.dport = NULL; pd.ip_sum = &h->ip_sum; pd.proto_sum = NULL; pd.proto = h->ip_p; pd.dir = dir; pd.sidx = (dir == PF_IN) ? 0 : 1; pd.didx = (dir == PF_IN) ? 1 : 0; pd.af = AF_INET; pd.tos = h->ip_tos; pd.tot_len = ntohs(h->ip_len); pd.eh = eh; /* handle fragments that didn't get reassembled by normalization */ if (h->ip_off & htons(IP_MF | IP_OFFMASK)) { action = pf_test_fragment(&r, dir, kif, m, h, &pd, &a, &ruleset); 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)) { if (action != PF_PASS) log |= PF_LOG_FORCE; goto done; } pd.p_len = pd.tot_len - off - (th.th_off << 2); if ((th.th_flags & TH_ACK) && pd.p_len == 0) pqid = 1; action = pf_normalize_tcp(dir, kif, m, 0, off, h, &pd); if (action == PF_DROP) goto done; action = pf_test_state_tcp(&s, dir, kif, m, off, h, &pd, &reason); if (action == PF_PASS) { #if NPFSYNC > 0 pfsync_update_state(s); #endif /* NPFSYNC */ r = s->rule.ptr; a = s->anchor.ptr; log |= s->log; } else if (s == NULL) action = pf_test_rule(&r, &s, dir, kif, m, off, h, &pd, &a, &ruleset, &ipintrq); if (s) { if (s->max_mss) pf_normalize_mss(m, off, &pd, s->max_mss); } else if (r->max_mss) pf_normalize_mss(m, off, &pd, r->max_mss); break; } case IPPROTO_UDP: { struct udphdr uh; pd.hdr.udp = &uh; if (!pf_pull_hdr(m, off, &uh, sizeof(uh), &action, &reason, AF_INET)) { if (action != PF_PASS) log |= PF_LOG_FORCE; goto done; } if (uh.uh_dport == 0 || ntohs(uh.uh_ulen) > m->m_pkthdr.len - off || ntohs(uh.uh_ulen) < sizeof(struct udphdr)) { action = PF_DROP; REASON_SET(&reason, PFRES_SHORT); goto done; } action = pf_test_state_udp(&s, dir, kif, m, off, h, &pd); if (action == PF_PASS) { #if NPFSYNC > 0 pfsync_update_state(s); #endif /* NPFSYNC */ r = s->rule.ptr; a = s->anchor.ptr; log |= s->log; } else if (s == NULL) action = pf_test_rule(&r, &s, dir, kif, m, off, h, &pd, &a, &ruleset, &ipintrq); break; } case IPPROTO_ICMP: { struct icmp ih; pd.hdr.icmp = &ih; if (!pf_pull_hdr(m, off, &ih, ICMP_MINLEN, &action, &reason, AF_INET)) { if (action != PF_PASS) log |= PF_LOG_FORCE; goto done; } action = pf_test_state_icmp(&s, dir, kif, m, off, h, &pd, &reason); if (action == PF_PASS) { #if NPFSYNC > 0 pfsync_update_state(s); #endif /* NPFSYNC */ r = s->rule.ptr; a = s->anchor.ptr; log |= s->log; } else if (s == NULL) action = pf_test_rule(&r, &s, dir, kif, m, off, h, &pd, &a, &ruleset, &ipintrq); break; } #ifdef INET6 case IPPROTO_ICMPV6: { action = PF_DROP; DPFPRINTF(PF_DEBUG_MISC, ("pf: dropping IPv4 packet with ICMPv6 payload\n")); goto done; } #endif default: action = pf_test_state_other(&s, dir, kif, m, &pd); if (action == PF_PASS) { #if NPFSYNC > 0 pfsync_update_state(s); #endif /* NPFSYNC */ r = s->rule.ptr; a = s->anchor.ptr; log |= s->log; } else if (s == NULL) action = pf_test_rule(&r, &s, dir, kif, m, off, h, &pd, &a, &ruleset, &ipintrq); break; } done: if (action == PF_PASS && h->ip_hl > 5 && !((s && s->state_flags & PFSTATE_ALLOWOPTS) || r->allow_opts)) { action = PF_DROP; REASON_SET(&reason, PFRES_IPOPTIONS); log |= PF_LOG_FORCE; DPFPRINTF(PF_DEBUG_MISC, ("pf: dropping packet with ip options\n")); } if (s) { pf_scrub_ip(&m, s->state_flags, s->min_ttl, s->set_tos); pf_tag_packet(m, s->tag, s->rtableid); if (pqid || (pd.tos & IPTOS_LOWDELAY)) qid = s->pqid; else qid = s->qid; } else { pf_scrub_ip(&m, r->scrub_flags, r->min_ttl, r->set_tos); pf_tag_packet(m, r->tag, r->rtableid); if (pqid || (pd.tos & IPTOS_LOWDELAY)) qid = r->pqid; else qid = r->qid; } if (dir == PF_IN && s && s->key[PF_SK_STACK]) m->m_pkthdr.pf.statekey = s->key[PF_SK_STACK]; #ifdef ALTQ if (action == PF_PASS && qid) { m->m_pkthdr.pf.qid = qid; m->m_pkthdr.pf.hdr = h; /* hints for ecn */ } #endif /* ALTQ */ /* * connections redirected to loopback should not match sockets * bound specifically to loopback due to security implications, * see tcp_input() and in_pcblookup_listen(). */ if (dir == PF_IN && action == PF_PASS && (pd.proto == IPPROTO_TCP || pd.proto == IPPROTO_UDP) && s != NULL && s->nat_rule.ptr != NULL && (s->nat_rule.ptr->action == PF_RDR || s->nat_rule.ptr->action == PF_BINAT) && (ntohl(pd.dst->v4.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) m->m_pkthdr.pf.flags |= PF_TAG_TRANSLATE_LOCALHOST; if (dir == PF_IN && action == PF_PASS && r->divert.port) { struct pf_divert *divert; if ((divert = pf_get_divert(m))) { m->m_pkthdr.pf.flags |= PF_TAG_DIVERTED; divert->port = r->divert.port; divert->addr.ipv4 = r->divert.addr.v4; } } if (log) { struct pf_rule *lr; struct pf_rule_item *ri; if (s != NULL && s->nat_rule.ptr != NULL && s->nat_rule.ptr->log & PF_LOG_ALL) lr = s->nat_rule.ptr; else lr = r; if (log & PF_LOG_FORCE || lr->log & PF_LOG_ALL) PFLOG_PACKET(kif, h, m, AF_INET, dir, reason, lr, a, ruleset, &pd); if (s) { SLIST_FOREACH(ri, &s->match_rules, entry) if (ri->r->log & PF_LOG_ALL) PFLOG_PACKET(kif, h, m, AF_INET, dir, reason, ri->r, a, ruleset, &pd); } } kif->pfik_bytes[0][dir == PF_OUT][action != PF_PASS] += pd.tot_len; kif->pfik_packets[0][dir == PF_OUT][action != PF_PASS]++; if (action == PF_PASS || r->action == PF_DROP) { dirndx = (dir == PF_OUT); r->packets[dirndx]++; r->bytes[dirndx] += pd.tot_len; if (a != NULL) { a->packets[dirndx]++; a->bytes[dirndx] += pd.tot_len; } if (s != NULL) { struct pf_rule_item *ri; if (s->nat_rule.ptr != NULL) { s->nat_rule.ptr->packets[dirndx]++; s->nat_rule.ptr->bytes[dirndx] += pd.tot_len; } if (s->src_node != NULL) { s->src_node->packets[dirndx]++; s->src_node->bytes[dirndx] += pd.tot_len; } if (s->nat_src_node != NULL) { s->nat_src_node->packets[dirndx]++; s->nat_src_node->bytes[dirndx] += pd.tot_len; } dirndx = (dir == s->direction) ? 0 : 1; s->packets[dirndx]++; s->bytes[dirndx] += pd.tot_len; SLIST_FOREACH(ri, &s->match_rules, entry) { ri->r->packets[dirndx]++; ri->r->bytes[dirndx] += pd.tot_len; } } tr = r; nr = (s != NULL) ? s->nat_rule.ptr : pd.nat_rule; if (nr != NULL && r == &pf_default_rule) tr = nr; if (tr->src.addr.type == PF_ADDR_TABLE) pfr_update_stats(tr->src.addr.p.tbl, (s == NULL) ? pd.src : &s->key[(s->direction == PF_IN)]-> addr[(s->direction == PF_OUT)], pd.af, pd.tot_len, dir == PF_OUT, r->action == PF_PASS, tr->src.neg); if (tr->dst.addr.type == PF_ADDR_TABLE) pfr_update_stats(tr->dst.addr.p.tbl, (s == NULL) ? pd.dst : &s->key[(s->direction == PF_IN)]-> addr[(s->direction == PF_IN)], pd.af, pd.tot_len, dir == PF_OUT, r->action == PF_PASS, tr->dst.neg); } switch (action) { case PF_SYNPROXY_DROP: m_freem(*m0); case PF_DEFER: *m0 = NULL; action = PF_PASS; break; default: /* pf_route can free the mbuf causing *m0 to become NULL */ if (r->rt) pf_route(m0, r, dir, kif->pfik_ifp, s, &pd); break; } return (action); } #endif /* INET */ #ifdef INET6 int pf_test6(int dir, struct ifnet *ifp, struct mbuf **m0, struct ether_header *eh) { struct pfi_kif *kif; u_short action, reason = 0, log = 0; struct mbuf *m = *m0, *n = NULL; struct ip6_hdr *h; struct pf_rule *a = NULL, *r = &pf_default_rule, *tr, *nr; struct pf_state *s = NULL; struct pf_ruleset *ruleset = NULL; struct pf_pdesc pd; int off, terminal = 0, dirndx, rh_cnt = 0; if (!pf_status.running) return (PF_PASS); memset(&pd, 0, sizeof(pd)); if (ifp->if_type == IFT_CARP && ifp->if_carpdev) kif = (struct pfi_kif *)ifp->if_carpdev->if_pf_kif; else kif = (struct pfi_kif *)ifp->if_pf_kif; if (kif == NULL) { DPFPRINTF(PF_DEBUG_URGENT, ("pf_test6: kif == NULL, if_xname %s\n", ifp->if_xname)); return (PF_DROP); } if (kif->pfik_flags & PFI_IFLAG_SKIP) return (PF_PASS); #ifdef DIAGNOSTIC if ((m->m_flags & M_PKTHDR) == 0) panic("non-M_PKTHDR is passed to pf_test6"); #endif /* DIAGNOSTIC */ if (m->m_pkthdr.len < (int)sizeof(*h)) { action = PF_DROP; REASON_SET(&reason, PFRES_SHORT); log = 1; goto done; } if (m->m_pkthdr.pf.flags & PF_TAG_GENERATED) return (PF_PASS); /* packet reassembly */ if (pf_normalize_ip6(m0, dir, kif, &reason, &pd) != PF_PASS) { action = PF_DROP; goto done; } m = *m0; /* pf_normalize messes with m0 */ h = mtod(m, struct ip6_hdr *); #if 1 /* * we do not support jumbogram yet. if we keep going, zero ip6_plen * will do something bad, so drop the packet for now. */ if (htons(h->ip6_plen) == 0) { action = PF_DROP; REASON_SET(&reason, PFRES_NORM); /*XXX*/ goto done; } #endif pd.src = (struct pf_addr *)&h->ip6_src; pd.dst = (struct pf_addr *)&h->ip6_dst; pd.sport = pd.dport = NULL; pd.ip_sum = NULL; pd.proto_sum = NULL; pd.dir = dir; pd.sidx = (dir == PF_IN) ? 0 : 1; pd.didx = (dir == PF_IN) ? 1 : 0; pd.af = AF_INET6; pd.tos = 0; pd.tot_len = ntohs(h->ip6_plen) + sizeof(struct ip6_hdr); pd.eh = eh; 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, kif, m, h, &pd, &a, &ruleset); if (action == PF_DROP) REASON_SET(&reason, PFRES_FRAG); goto done; case IPPROTO_ROUTING: { struct ip6_rthdr rthdr; if (rh_cnt++) { DPFPRINTF(PF_DEBUG_MISC, ("pf: IPv6 more than one rthdr\n")); action = PF_DROP; REASON_SET(&reason, PFRES_IPOPTIONS); log = 1; goto done; } if (!pf_pull_hdr(m, off, &rthdr, sizeof(rthdr), NULL, &reason, pd.af)) { DPFPRINTF(PF_DEBUG_MISC, ("pf: IPv6 short rthdr\n")); action = PF_DROP; REASON_SET(&reason, PFRES_SHORT); log = 1; goto done; } if (rthdr.ip6r_type == IPV6_RTHDR_TYPE_0) { DPFPRINTF(PF_DEBUG_MISC, ("pf: IPv6 rthdr0\n")); action = PF_DROP; REASON_SET(&reason, PFRES_IPOPTIONS); log = 1; goto done; } /* FALLTHROUGH */ } case IPPROTO_AH: case IPPROTO_HOPOPTS: case IPPROTO_DSTOPTS: { /* get next header and header length */ struct ip6_ext opt6; if (!pf_pull_hdr(m, off, &opt6, sizeof(opt6), NULL, &reason, pd.af)) { DPFPRINTF(PF_DEBUG_MISC, ("pf: IPv6 short opt\n")); action = PF_DROP; 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); /* if there's no routing header, use unmodified mbuf for checksumming */ if (!n) n = m; 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, kif, m, 0, off, h, &pd); if (action == PF_DROP) goto done; action = pf_test_state_tcp(&s, dir, kif, m, off, h, &pd, &reason); if (action == PF_PASS) { #if NPFSYNC > 0 pfsync_update_state(s); #endif /* NPFSYNC */ r = s->rule.ptr; a = s->anchor.ptr; log = s->log; } else if (s == NULL) action = pf_test_rule(&r, &s, dir, kif, m, off, h, &pd, &a, &ruleset, &ip6intrq); break; } case IPPROTO_UDP: { struct udphdr uh; pd.hdr.udp = &uh; if (!pf_pull_hdr(m, off, &uh, sizeof(uh), &action, &reason, AF_INET6)) { log = action != PF_PASS; goto done; } if (uh.uh_dport == 0 || ntohs(uh.uh_ulen) > m->m_pkthdr.len - off || ntohs(uh.uh_ulen) < sizeof(struct udphdr)) { action = PF_DROP; REASON_SET(&reason, PFRES_SHORT); goto done; } action = pf_test_state_udp(&s, dir, kif, m, off, h, &pd); if (action == PF_PASS) { #if NPFSYNC > 0 pfsync_update_state(s); #endif /* NPFSYNC */ r = s->rule.ptr; a = s->anchor.ptr; log = s->log; } else if (s == NULL) action = pf_test_rule(&r, &s, dir, kif, m, off, h, &pd, &a, &ruleset, &ip6intrq); break; } case IPPROTO_ICMP: { action = PF_DROP; DPFPRINTF(PF_DEBUG_MISC, ("pf: dropping IPv6 packet with ICMPv4 payload\n")); goto done; } case IPPROTO_ICMPV6: { union { struct icmp6_hdr icmp6; struct mld_hdr mld; struct nd_neighbor_solicit nd; } ih; size_t icmp_hlen = sizeof(struct icmp6_hdr); pd.hdr.icmp6 = &ih.icmp6; if (!pf_pull_hdr(m, off, &ih, icmp_hlen, &action, &reason, AF_INET6)) { log = action != PF_PASS; goto done; } /* ICMP headers we look further into to match state */ switch (ih.icmp6.icmp6_type) { case MLD_LISTENER_QUERY: case MLD_LISTENER_REPORT: icmp_hlen = sizeof(struct mld_hdr); break; case ND_NEIGHBOR_SOLICIT: case ND_NEIGHBOR_ADVERT: icmp_hlen = sizeof(struct nd_neighbor_solicit); break; } if (icmp_hlen > sizeof(struct icmp6_hdr) && !pf_pull_hdr(m, off, &ih, icmp_hlen, &action, &reason, AF_INET6)) { log = action != PF_PASS; goto done; } action = pf_test_state_icmp(&s, dir, kif, m, off, h, &pd, &reason); if (action == PF_PASS) { #if NPFSYNC > 0 pfsync_update_state(s); #endif /* NPFSYNC */ r = s->rule.ptr; a = s->anchor.ptr; log = s->log; } else if (s == NULL) action = pf_test_rule(&r, &s, dir, kif, m, off, h, &pd, &a, &ruleset, &ip6intrq); break; } default: action = pf_test_state_other(&s, dir, kif, m, &pd); if (action == PF_PASS) { #if NPFSYNC > 0 pfsync_update_state(s); #endif /* NPFSYNC */ r = s->rule.ptr; a = s->anchor.ptr; log = s->log; } else if (s == NULL) action = pf_test_rule(&r, &s, dir, kif, m, off, h, &pd, &a, &ruleset, &ip6intrq); break; } done: if (n != m) { m_freem(n); n = NULL; } /* handle dangerous IPv6 extension headers. */ if (action == PF_PASS && rh_cnt && !((s && s->state_flags & PFSTATE_ALLOWOPTS) || r->allow_opts)) { action = PF_DROP; REASON_SET(&reason, PFRES_IPOPTIONS); log = 1; DPFPRINTF(PF_DEBUG_MISC, ("pf: dropping packet with dangerous v6 headers\n")); } if (s) pf_scrub_ip6(&m, s->min_ttl); else pf_scrub_ip6(&m, r->min_ttl); if (s && (s->tag || s->rtableid)) pf_tag_packet(m, s ? s->tag : 0, s->rtableid); if (dir == PF_IN && s && s->key[PF_SK_STACK]) m->m_pkthdr.pf.statekey = s->key[PF_SK_STACK]; #ifdef ALTQ if (action == PF_PASS && s && s->qid) { if (pd.tos & IPTOS_LOWDELAY) m->m_pkthdr.pf.qid = s->pqid; else m->m_pkthdr.pf.qid = s->qid; /* add hints for ecn */ m->m_pkthdr.pf.hdr = h; } #endif /* ALTQ */ if (dir == PF_IN && action == PF_PASS && (pd.proto == IPPROTO_TCP || pd.proto == IPPROTO_UDP) && s != NULL && s->nat_rule.ptr != NULL && (s->nat_rule.ptr->action == PF_RDR || s->nat_rule.ptr->action == PF_BINAT) && IN6_IS_ADDR_LOOPBACK(&pd.dst->v6)) m->m_pkthdr.pf.flags |= PF_TAG_TRANSLATE_LOCALHOST; if (dir == PF_IN && action == PF_PASS && r->divert.port) { struct pf_divert *divert; if ((divert = pf_get_divert(m))) { m->m_pkthdr.pf.flags |= PF_TAG_DIVERTED; divert->port = r->divert.port; divert->addr.ipv6 = r->divert.addr.v6; } } if (log) { struct pf_rule *lr; if (s != NULL && s->nat_rule.ptr != NULL && s->nat_rule.ptr->log & PF_LOG_ALL) lr = s->nat_rule.ptr; else lr = r; PFLOG_PACKET(kif, h, m, AF_INET6, dir, reason, lr, a, ruleset, &pd); } kif->pfik_bytes[1][dir == PF_OUT][action != PF_PASS] += pd.tot_len; kif->pfik_packets[1][dir == PF_OUT][action != PF_PASS]++; if (action == PF_PASS || r->action == PF_DROP) { dirndx = (dir == PF_OUT); r->packets[dirndx]++; r->bytes[dirndx] += pd.tot_len; if (a != NULL) { a->packets[dirndx]++; a->bytes[dirndx] += pd.tot_len; } if (s != NULL) { if (s->nat_rule.ptr != NULL) { s->nat_rule.ptr->packets[dirndx]++; s->nat_rule.ptr->bytes[dirndx] += pd.tot_len; } if (s->src_node != NULL) { s->src_node->packets[dirndx]++; s->src_node->bytes[dirndx] += pd.tot_len; } if (s->nat_src_node != NULL) { s->nat_src_node->packets[dirndx]++; s->nat_src_node->bytes[dirndx] += pd.tot_len; } dirndx = (dir == s->direction) ? 0 : 1; s->packets[dirndx]++; s->bytes[dirndx] += pd.tot_len; } tr = r; nr = (s != NULL) ? s->nat_rule.ptr : pd.nat_rule; if (nr != NULL && r == &pf_default_rule) tr = nr; if (tr->src.addr.type == PF_ADDR_TABLE) pfr_update_stats(tr->src.addr.p.tbl, (s == NULL) ? pd.src : &s->key[(s->direction == PF_IN)]->addr[0], pd.af, pd.tot_len, dir == PF_OUT, r->action == PF_PASS, tr->src.neg); if (tr->dst.addr.type == PF_ADDR_TABLE) pfr_update_stats(tr->dst.addr.p.tbl, (s == NULL) ? pd.dst : &s->key[(s->direction == PF_IN)]->addr[1], pd.af, pd.tot_len, dir == PF_OUT, r->action == PF_PASS, tr->dst.neg); } switch (action) { case PF_SYNPROXY_DROP: m_freem(*m0); case PF_DEFER: *m0 = NULL; action = PF_PASS; break; default: /* pf_route6 can free the mbuf causing *m0 to become NULL */ if (r->rt) pf_route6(m0, r, dir, kif->pfik_ifp, s, &pd); break; } return (action); } #endif /* INET6 */ int pf_check_congestion(struct ifqueue *ifq) { if (ifq->ifq_congestion) return (1); else return (0); } /* * must be called whenever any addressing information such as * address, port, protocol has changed */ void pf_pkt_addr_changed(struct mbuf *m) { m->m_pkthdr.pf.statekey = NULL; }