/* $OpenBSD: pf.c,v 1.1206 2024/11/08 13:22:09 sashan Exp $ */ /* * Copyright (c) 2001 Daniel Hartmeier * Copyright (c) 2002 - 2013 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 "carp.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 #ifdef INET6 #include #include #include #include #include #include #endif /* INET6 */ #include #include #if NPFLOG > 0 #include #endif /* NPFLOG > 0 */ #if NPFLOW > 0 #include #endif /* NPFLOW > 0 */ #if NPFSYNC > 0 #include #endif /* NPFSYNC > 0 */ /* * Global variables */ struct pf_state_tree pf_statetbl; struct pf_queuehead pf_queues[2]; struct pf_queuehead *pf_queues_active; struct pf_queuehead *pf_queues_inactive; struct pf_status pf_status; struct mutex pf_inp_mtx = MUTEX_INITIALIZER(IPL_SOFTNET); int pf_hdr_limit = 20; /* arbitrary limit, tune in ddb */ SHA2_CTX pf_tcp_secret_ctx; u_char pf_tcp_secret[16]; int pf_tcp_secret_init; int pf_tcp_iss_off; enum pf_test_status { PF_TEST_FAIL = -1, PF_TEST_OK, PF_TEST_QUICK }; struct pf_test_ctx { struct pf_pdesc *pd; struct pf_rule_actions act; u_int8_t icmpcode; u_int8_t icmptype; int icmp_dir; int state_icmp; int tag; u_short reason; struct pf_rule_item *ri; struct pf_src_node *sns[PF_SN_MAX]; struct pf_rule_slist rules; struct pf_rule *nr; struct pf_rule **rm; struct pf_rule *a; struct pf_rule **am; struct pf_ruleset **rsm; struct pf_ruleset *arsm; struct pf_ruleset *aruleset; struct tcphdr *th; }; struct pool pf_src_tree_pl, pf_rule_pl, pf_queue_pl; struct pool pf_state_pl, pf_state_key_pl, pf_state_item_pl; struct pool pf_rule_item_pl, pf_sn_item_pl, pf_pktdelay_pl; void pf_add_threshold(struct pf_threshold *); int pf_check_threshold(struct pf_threshold *); int pf_check_tcp_cksum(struct mbuf *, int, int, sa_family_t); __inline void pf_cksum_fixup(u_int16_t *, u_int16_t, u_int16_t, u_int8_t); void pf_cksum_fixup_a(u_int16_t *, const struct pf_addr *, const struct pf_addr *, sa_family_t, u_int8_t); int pf_modulate_sack(struct pf_pdesc *, struct pf_state_peer *); int pf_icmp_mapping(struct pf_pdesc *, u_int8_t, int *, u_int16_t *, u_int16_t *); int pf_change_icmp_af(struct mbuf *, int, struct pf_pdesc *, struct pf_pdesc *, struct pf_addr *, struct pf_addr *, sa_family_t, sa_family_t); int pf_translate_a(struct pf_pdesc *, struct pf_addr *, struct pf_addr *); void pf_translate_icmp(struct pf_pdesc *, struct pf_addr *, u_int16_t *, struct pf_addr *, struct pf_addr *, u_int16_t); int pf_translate_icmp_af(struct pf_pdesc*, int, void *); void pf_send_icmp(struct mbuf *, u_int8_t, u_int8_t, int, sa_family_t, struct pf_rule *, u_int); void pf_detach_state(struct pf_state *); struct pf_state_key *pf_state_key_attach(struct pf_state_key *, struct pf_state *, int); 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_pdesc *, struct pf_rule **, struct pf_state **, struct pf_rule **, struct pf_ruleset **, u_short *); static __inline int pf_create_state(struct pf_pdesc *, struct pf_rule *, struct pf_rule *, struct pf_rule *, struct pf_state_key **, struct pf_state_key **, int *, struct pf_state **, int, struct pf_rule_slist *, struct pf_rule_actions *, struct pf_src_node **); static __inline int pf_state_key_addr_setup(struct pf_pdesc *, void *, int, struct pf_addr *, int, struct pf_addr *, int, int); int pf_state_key_setup(struct pf_pdesc *, struct pf_state_key **, struct pf_state_key **, int); int pf_tcp_track_full(struct pf_pdesc *, struct pf_state **, u_short *, int *, int); int pf_tcp_track_sloppy(struct pf_pdesc *, struct pf_state **, u_short *); static __inline int pf_synproxy(struct pf_pdesc *, struct pf_state **, u_short *); int pf_test_state(struct pf_pdesc *, struct pf_state **, u_short *); int pf_icmp_state_lookup(struct pf_pdesc *, struct pf_state_key_cmp *, struct pf_state **, u_int16_t, u_int16_t, int, int *, int, int); int pf_test_state_icmp(struct pf_pdesc *, struct pf_state **, u_short *); u_int16_t pf_calc_mss(struct pf_addr *, sa_family_t, int, u_int16_t); static __inline int pf_set_rt_ifp(struct pf_state *, struct pf_addr *, sa_family_t, struct pf_src_node **); struct pf_divert *pf_get_divert(struct mbuf *); int pf_walk_option(struct pf_pdesc *, struct ip *, int, int, u_short *); int pf_walk_header(struct pf_pdesc *, struct ip *, u_short *); int pf_walk_option6(struct pf_pdesc *, struct ip6_hdr *, int, int, u_short *); int pf_walk_header6(struct pf_pdesc *, struct ip6_hdr *, u_short *); 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); u_int16_t pf_pkt_hash(sa_family_t, uint8_t, const struct pf_addr *, const struct pf_addr *, uint16_t, uint16_t); int pf_find_state(struct pf_pdesc *, struct pf_state_key_cmp *, struct pf_state **); int pf_src_connlimit(struct pf_state **); int pf_match_rcvif(struct mbuf *, struct pf_rule *); enum pf_test_status pf_match_rule(struct pf_test_ctx *, struct pf_ruleset *); void pf_counters_inc(int, struct pf_pdesc *, struct pf_state *, struct pf_rule *, struct pf_rule *); int pf_state_insert(struct pfi_kif *, struct pf_state_key **, struct pf_state_key **, struct pf_state *); int pf_state_key_isvalid(struct pf_state_key *); struct pf_state_key *pf_state_key_ref(struct pf_state_key *); void pf_state_key_unref(struct pf_state_key *); void pf_state_key_link_reverse(struct pf_state_key *, struct pf_state_key *); void pf_state_key_unlink_reverse(struct pf_state_key *); void pf_state_key_link_inpcb(struct pf_state_key *, struct inpcb *); void pf_state_key_unlink_inpcb(struct pf_state_key *); void pf_pktenqueue_delayed(void *); int32_t pf_state_expires(const struct pf_state *, uint8_t); #if NPFLOG > 0 void pf_log_matches(struct pf_pdesc *, struct pf_rule *, struct pf_rule *, struct pf_ruleset *, struct pf_rule_slist *); #endif /* NPFLOG > 0 */ 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 }, { &pf_pktdelay_pl, PF_PKTDELAY_MAXPKTS, PF_PKTDELAY_MAXPKTS }, { &pf_anchor_pl, PF_ANCHOR_HIWAT, PF_ANCHOR_HIWAT } }; #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++; \ } \ 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(const struct pf_state_key *, const struct pf_state_key *); static inline int pf_state_compare_id(const struct pf_state *, const struct pf_state *); #ifdef INET6 static __inline void pf_cksum_uncover(u_int16_t *, u_int16_t, u_int8_t); static __inline void pf_cksum_cover(u_int16_t *, u_int16_t, u_int8_t); #endif /* INET6 */ static __inline void pf_set_protostate(struct pf_state *, int, u_int8_t); struct pf_src_tree tree_src_tracking; struct pf_state_tree_id tree_id; struct pf_state_list pf_state_list = PF_STATE_LIST_INITIALIZER(pf_state_list); RB_GENERATE(pf_src_tree, pf_src_node, entry, pf_src_compare); RBT_GENERATE(pf_state_tree, pf_state_key, sk_entry, pf_state_compare_key); RBT_GENERATE(pf_state_tree_id, pf_state, entry_id, pf_state_compare_id); int pf_addr_compare(const struct pf_addr *a, const struct pf_addr *b, sa_family_t af) { switch (af) { case AF_INET: if (a->addr32[0] > b->addr32[0]) return (1); if (a->addr32[0] < b->addr32[0]) return (-1); break; #ifdef INET6 case AF_INET6: if (a->addr32[3] > b->addr32[3]) return (1); if (a->addr32[3] < b->addr32[3]) return (-1); if (a->addr32[2] > b->addr32[2]) return (1); if (a->addr32[2] < b->addr32[2]) return (-1); if (a->addr32[1] > b->addr32[1]) return (1); if (a->addr32[1] < b->addr32[1]) return (-1); if (a->addr32[0] > b->addr32[0]) return (1); if (a->addr32[0] < b->addr32[0]) return (-1); break; #endif /* INET6 */ } return (0); } 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->type - b->type) != 0) return (diff); if ((diff = a->af - b->af) != 0) return (diff); if ((diff = pf_addr_compare(&a->addr, &b->addr, a->af)) != 0) return (diff); return (0); } static __inline void pf_set_protostate(struct pf_state *st, int which, u_int8_t newstate) { if (which == PF_PEER_DST || which == PF_PEER_BOTH) st->dst.state = newstate; if (which == PF_PEER_DST) return; if (st->src.state == newstate) return; if (st->creatorid == pf_status.hostid && st->key[PF_SK_STACK]->proto == IPPROTO_TCP && !(TCPS_HAVEESTABLISHED(st->src.state) || st->src.state == TCPS_CLOSED) && (TCPS_HAVEESTABLISHED(newstate) || newstate == TCPS_CLOSED)) pf_status.states_halfopen--; st->src.state = newstate; } void pf_addrcpy(struct pf_addr *dst, struct pf_addr *src, sa_family_t af) { switch (af) { case AF_INET: dst->addr32[0] = src->addr32[0]; break; #ifdef INET6 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 */ default: unhandled_af(af); } } 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 = getuptime(); } void pf_add_threshold(struct pf_threshold *threshold) { u_int32_t t = getuptime(), 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); } void pf_state_list_insert(struct pf_state_list *pfs, struct pf_state *st) { /* * we can always put states on the end of the list. * * things reading the list should take a read lock, then * the mutex, get the head and tail pointers, release the * mutex, and then they can iterate between the head and tail. */ pf_state_ref(st); /* get a ref for the list */ mtx_enter(&pfs->pfs_mtx); TAILQ_INSERT_TAIL(&pfs->pfs_list, st, entry_list); mtx_leave(&pfs->pfs_mtx); } void pf_state_list_remove(struct pf_state_list *pfs, struct pf_state *st) { /* states can only be removed when the write lock is held */ rw_assert_wrlock(&pfs->pfs_rwl); mtx_enter(&pfs->pfs_mtx); TAILQ_REMOVE(&pfs->pfs_list, st, entry_list); mtx_leave(&pfs->pfs_mtx); pf_state_unref(st); /* list no longer references the state */ } void pf_update_state_timeout(struct pf_state *st, int to) { mtx_enter(&st->mtx); if (st->timeout != PFTM_UNLINKED) st->timeout = to; mtx_leave(&st->mtx); } int pf_src_connlimit(struct pf_state **stp) { int bad = 0; struct pf_src_node *sn; if ((sn = pf_get_src_node((*stp), PF_SN_NONE)) == NULL) return (0); sn->conn++; (*stp)->src.tcp_est = 1; pf_add_threshold(&sn->conn_rate); if ((*stp)->rule.ptr->max_src_conn && (*stp)->rule.ptr->max_src_conn < sn->conn) { pf_status.lcounters[LCNT_SRCCONN]++; bad++; } if ((*stp)->rule.ptr->max_src_conn_rate.limit && pf_check_threshold(&sn->conn_rate)) { pf_status.lcounters[LCNT_SRCCONNRATE]++; bad++; } if (!bad) return (0); if ((*stp)->rule.ptr->overload_tbl) { struct pfr_addr p; u_int32_t killed = 0; pf_status.lcounters[LCNT_OVERLOAD_TABLE]++; if (pf_status.debug >= LOG_NOTICE) { log(LOG_NOTICE, "pf: pf_src_connlimit: blocking address "); pf_print_host(&sn->addr, 0, (*stp)->key[PF_SK_WIRE]->af); } memset(&p, 0, sizeof(p)); p.pfra_af = (*stp)->key[PF_SK_WIRE]->af; switch ((*stp)->key[PF_SK_WIRE]->af) { case AF_INET: p.pfra_net = 32; p.pfra_ip4addr = sn->addr.v4; break; #ifdef INET6 case AF_INET6: p.pfra_net = 128; p.pfra_ip6addr = sn->addr.v6; break; #endif /* INET6 */ } pfr_insert_kentry((*stp)->rule.ptr->overload_tbl, &p, gettime()); /* kill existing states if that's required. */ if ((*stp)->rule.ptr->flush) { struct pf_state_key *sk; struct pf_state *st; pf_status.lcounters[LCNT_OVERLOAD_FLUSH]++; RBT_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 == (*stp)->key[PF_SK_WIRE]->af && (((*stp)->direction == PF_OUT && PF_AEQ(&sn->addr, &sk->addr[1], sk->af)) || ((*stp)->direction == PF_IN && PF_AEQ(&sn->addr, &sk->addr[0], sk->af))) && ((*stp)->rule.ptr->flush & PF_FLUSH_GLOBAL || (*stp)->rule.ptr == st->rule.ptr)) { pf_update_state_timeout(st, PFTM_PURGE); pf_set_protostate(st, PF_PEER_BOTH, TCPS_CLOSED); killed++; } } if (pf_status.debug >= LOG_NOTICE) addlog(", %u states killed", killed); } if (pf_status.debug >= LOG_NOTICE) addlog("\n"); } /* kill this state */ pf_update_state_timeout(*stp, PFTM_PURGE); pf_set_protostate(*stp, PF_PEER_BOTH, TCPS_CLOSED); return (1); } int pf_insert_src_node(struct pf_src_node **sn, struct pf_rule *rule, enum pf_sn_types type, sa_family_t af, struct pf_addr *src, struct pf_addr *raddr, struct pfi_kif *kif) { struct pf_src_node k; if (*sn == NULL) { k.af = af; k.type = type; pf_addrcpy(&k.addr, src, af); k.rule.ptr = rule; 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)->type = type; (*sn)->af = af; (*sn)->rule.ptr = rule; pf_addrcpy(&(*sn)->addr, src, af); if (raddr) pf_addrcpy(&(*sn)->raddr, raddr, af); if (RB_INSERT(pf_src_tree, &tree_src_tracking, *sn) != NULL) { if (pf_status.debug >= LOG_NOTICE) { log(LOG_NOTICE, "pf: src_tree insert failed: "); pf_print_host(&(*sn)->addr, 0, af); addlog("\n"); } pool_put(&pf_src_tree_pl, *sn); return (-1); } (*sn)->creation = getuptime(); (*sn)->rule.ptr->src_nodes++; if (kif != NULL) { (*sn)->kif = kif; pfi_kif_ref(kif, PFI_KIF_REF_SRCNODE); } 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); } void pf_remove_src_node(struct pf_src_node *sn) { if (sn->states > 0 || sn->expire > getuptime()) return; sn->rule.ptr->src_nodes--; if (sn->rule.ptr->states_cur == 0 && sn->rule.ptr->src_nodes == 0) pf_rm_rule(NULL, sn->rule.ptr); RB_REMOVE(pf_src_tree, &tree_src_tracking, sn); pf_status.scounters[SCNT_SRC_NODE_REMOVALS]++; pf_status.src_nodes--; pfi_kif_unref(sn->kif, PFI_KIF_REF_SRCNODE); pool_put(&pf_src_tree_pl, sn); } struct pf_src_node * pf_get_src_node(struct pf_state *st, enum pf_sn_types type) { struct pf_sn_item *sni; SLIST_FOREACH(sni, &st->src_nodes, next) if (sni->sn->type == type) return (sni->sn); return (NULL); } void pf_state_rm_src_node(struct pf_state *st, struct pf_src_node *sn) { struct pf_sn_item *sni, *snin, *snip = NULL; for (sni = SLIST_FIRST(&st->src_nodes); sni; sni = snin) { snin = SLIST_NEXT(sni, next); if (sni->sn == sn) { if (snip) SLIST_REMOVE_AFTER(snip, next); else SLIST_REMOVE_HEAD(&st->src_nodes, next); pool_put(&pf_sn_item_pl, sni); sni = NULL; sn->states--; } if (sni != NULL) snip = sni; } } /* state table stuff */ static inline int pf_state_compare_key(const struct pf_state_key *a, const struct pf_state_key *b) { int diff; if ((diff = a->hash - b->hash) != 0) return (diff); if ((diff = a->proto - b->proto) != 0) return (diff); if ((diff = a->af - b->af) != 0) return (diff); if ((diff = pf_addr_compare(&a->addr[0], &b->addr[0], a->af)) != 0) return (diff); if ((diff = pf_addr_compare(&a->addr[1], &b->addr[1], a->af)) != 0) return (diff); if ((diff = a->port[0] - b->port[0]) != 0) return (diff); if ((diff = a->port[1] - b->port[1]) != 0) return (diff); if ((diff = a->rdomain - b->rdomain) != 0) return (diff); return (0); } static inline int pf_state_compare_id(const struct pf_state *a, const 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); } /* * on failure, pf_state_key_attach() releases the pf_state_key * reference and returns NULL. */ struct pf_state_key * pf_state_key_attach(struct pf_state_key *sk, struct pf_state *st, int idx) { struct pf_state_item *si; struct pf_state_key *cur; struct pf_state *oldst = NULL; PF_ASSERT_LOCKED(); KASSERT(st->key[idx] == NULL); sk->sk_removed = 0; cur = RBT_INSERT(pf_state_tree, &pf_statetbl, sk); if (cur != NULL) { sk->sk_removed = 1; /* key exists. check for same kif, if none, add to key */ TAILQ_FOREACH(si, &cur->sk_states, si_entry) { struct pf_state *sist = si->si_st; if (sist->kif == st->kif && ((sist->key[PF_SK_WIRE]->af == sk->af && sist->direction == st->direction) || (sist->key[PF_SK_WIRE]->af != sist->key[PF_SK_STACK]->af && sk->af == sist->key[PF_SK_STACK]->af && sist->direction != st->direction))) { int reuse = 0; if (sk->proto == IPPROTO_TCP && sist->src.state >= TCPS_FIN_WAIT_2 && sist->dst.state >= TCPS_FIN_WAIT_2) reuse = 1; if (pf_status.debug >= LOG_NOTICE) { log(LOG_NOTICE, "pf: %s key attach %s on %s: ", (idx == PF_SK_WIRE) ? "wire" : "stack", reuse ? "reuse" : "failed", st->kif->pfik_name); pf_print_state_parts(st, (idx == PF_SK_WIRE) ? sk : NULL, (idx == PF_SK_STACK) ? sk : NULL); addlog(", existing: "); pf_print_state_parts(sist, (idx == PF_SK_WIRE) ? sk : NULL, (idx == PF_SK_STACK) ? sk : NULL); addlog("\n"); } if (reuse) { pf_set_protostate(sist, PF_PEER_BOTH, TCPS_CLOSED); /* remove late or sks can go away */ oldst = sist; } else { pf_state_key_unref(sk); return (NULL); /* collision! */ } } } /* reuse the existing state key */ pf_state_key_unref(sk); sk = cur; } if ((si = pool_get(&pf_state_item_pl, PR_NOWAIT)) == NULL) { if (TAILQ_EMPTY(&sk->sk_states)) { KASSERT(cur == NULL); RBT_REMOVE(pf_state_tree, &pf_statetbl, sk); sk->sk_removed = 1; pf_state_key_unref(sk); } return (NULL); } st->key[idx] = pf_state_key_ref(sk); /* give a ref to state */ si->si_st = pf_state_ref(st); /* list is sorted, if-bound states before floating */ if (st->kif == pfi_all) TAILQ_INSERT_TAIL(&sk->sk_states, si, si_entry); else TAILQ_INSERT_HEAD(&sk->sk_states, si, si_entry); if (oldst) pf_remove_state(oldst); /* caller owns the pf_state ref, which owns a pf_state_key ref now */ return (sk); } void pf_detach_state(struct pf_state *st) { KASSERT(st->key[PF_SK_WIRE] != NULL); pf_state_key_detach(st, PF_SK_WIRE); KASSERT(st->key[PF_SK_STACK] != NULL); if (st->key[PF_SK_STACK] != st->key[PF_SK_WIRE]) pf_state_key_detach(st, PF_SK_STACK); } void pf_state_key_detach(struct pf_state *st, int idx) { struct pf_state_item *si; struct pf_state_key *sk; PF_ASSERT_LOCKED(); sk = st->key[idx]; if (sk == NULL) return; TAILQ_FOREACH(si, &sk->sk_states, si_entry) { if (si->si_st == st) break; } if (si == NULL) return; TAILQ_REMOVE(&sk->sk_states, si, si_entry); pool_put(&pf_state_item_pl, si); if (TAILQ_EMPTY(&sk->sk_states)) { RBT_REMOVE(pf_state_tree, &pf_statetbl, sk); sk->sk_removed = 1; pf_state_key_unlink_reverse(sk); pf_state_key_unlink_inpcb(sk); pf_state_key_unref(sk); } pf_state_unref(st); } 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); PF_REF_INIT(sk->sk_refcnt); TAILQ_INIT(&sk->sk_states); sk->sk_removed = 1; return (sk); } static __inline int pf_state_key_addr_setup(struct pf_pdesc *pd, void *arg, int sidx, struct pf_addr *saddr, int didx, struct pf_addr *daddr, int af, int multi) { struct pf_state_key_cmp *key = arg; #ifdef INET6 struct pf_addr *target; if (af == AF_INET || pd->proto != IPPROTO_ICMPV6) goto copy; switch (pd->hdr.icmp6.icmp6_type) { case ND_NEIGHBOR_SOLICIT: if (multi) return (-1); target = (struct pf_addr *)&pd->hdr.nd_ns.nd_ns_target; daddr = target; break; case ND_NEIGHBOR_ADVERT: if (multi) return (-1); target = (struct pf_addr *)&pd->hdr.nd_ns.nd_ns_target; saddr = target; if (IN6_IS_ADDR_MULTICAST(&pd->dst->v6)) { key->addr[didx].addr32[0] = 0; key->addr[didx].addr32[1] = 0; key->addr[didx].addr32[2] = 0; key->addr[didx].addr32[3] = 0; daddr = NULL; /* overwritten */ } break; default: if (multi) { key->addr[sidx].addr32[0] = __IPV6_ADDR_INT32_MLL; key->addr[sidx].addr32[1] = 0; key->addr[sidx].addr32[2] = 0; key->addr[sidx].addr32[3] = __IPV6_ADDR_INT32_ONE; saddr = NULL; /* overwritten */ } } copy: #endif /* INET6 */ if (saddr) pf_addrcpy(&key->addr[sidx], saddr, af); if (daddr) pf_addrcpy(&key->addr[didx], daddr, af); return (0); } int pf_state_key_setup(struct pf_pdesc *pd, struct pf_state_key **skw, struct pf_state_key **sks, int rtableid) { /* if returning error we MUST pool_put state keys ourselves */ struct pf_state_key *sk1, *sk2; u_int wrdom = pd->rdomain; int afto = pd->af != pd->naf; if ((sk1 = pf_alloc_state_key(PR_NOWAIT | PR_ZERO)) == NULL) return (ENOMEM); pf_state_key_addr_setup(pd, sk1, pd->sidx, pd->src, pd->didx, pd->dst, pd->af, 0); sk1->port[pd->sidx] = pd->osport; sk1->port[pd->didx] = pd->odport; sk1->proto = pd->proto; sk1->af = pd->af; sk1->rdomain = pd->rdomain; sk1->hash = pf_pkt_hash(sk1->af, sk1->proto, &sk1->addr[0], &sk1->addr[1], sk1->port[0], sk1->port[1]); if (rtableid >= 0) wrdom = rtable_l2(rtableid); if (PF_ANEQ(&pd->nsaddr, pd->src, pd->af) || PF_ANEQ(&pd->ndaddr, pd->dst, pd->af) || pd->nsport != pd->osport || pd->ndport != pd->odport || wrdom != pd->rdomain || afto) { /* NAT/NAT64 */ if ((sk2 = pf_alloc_state_key(PR_NOWAIT | PR_ZERO)) == NULL) { pf_state_key_unref(sk1); return (ENOMEM); } pf_state_key_addr_setup(pd, sk2, afto ? pd->didx : pd->sidx, &pd->nsaddr, afto ? pd->sidx : pd->didx, &pd->ndaddr, pd->naf, 0); sk2->port[afto ? pd->didx : pd->sidx] = pd->nsport; sk2->port[afto ? pd->sidx : pd->didx] = pd->ndport; if (afto) { switch (pd->proto) { case IPPROTO_ICMP: sk2->proto = IPPROTO_ICMPV6; break; case IPPROTO_ICMPV6: sk2->proto = IPPROTO_ICMP; break; default: sk2->proto = pd->proto; } } else sk2->proto = pd->proto; sk2->af = pd->naf; sk2->rdomain = wrdom; sk2->hash = pf_pkt_hash(sk2->af, sk2->proto, &sk2->addr[0], &sk2->addr[1], sk2->port[0], sk2->port[1]); } else sk2 = pf_state_key_ref(sk1); if (pd->dir == PF_IN) { *skw = sk1; *sks = sk2; } else { *sks = sk1; *skw = sk2; } if (pf_status.debug >= LOG_DEBUG) { log(LOG_DEBUG, "pf: key setup: "); pf_print_state_parts(NULL, *skw, *sks); addlog("\n"); } return (0); } /* * pf_state_insert() does the following: * - links the pf_state up with pf_state_key(s). * - inserts the pf_state_keys into pf_state_tree. * - inserts the pf_state into the into pf_state_tree_id. * - tells pfsync about the state. * * pf_state_insert() owns the references to the pf_state_key structs * it is given. on failure to insert, these references are released. * on success, the caller owns a pf_state reference that allows it * to access the state keys. */ int pf_state_insert(struct pfi_kif *kif, struct pf_state_key **skwp, struct pf_state_key **sksp, struct pf_state *st) { struct pf_state_key *skw = *skwp; struct pf_state_key *sks = *sksp; int same = (skw == sks); PF_ASSERT_LOCKED(); st->kif = kif; PF_STATE_ENTER_WRITE(); skw = pf_state_key_attach(skw, st, PF_SK_WIRE); if (skw == NULL) { pf_state_key_unref(sks); PF_STATE_EXIT_WRITE(); return (-1); } if (same) { /* pf_state_key_attach might have swapped skw */ pf_state_key_unref(sks); st->key[PF_SK_STACK] = sks = pf_state_key_ref(skw); } else if (pf_state_key_attach(sks, st, PF_SK_STACK) == NULL) { pf_state_key_detach(st, PF_SK_WIRE); PF_STATE_EXIT_WRITE(); return (-1); } if (st->id == 0 && st->creatorid == 0) { st->id = htobe64(pf_status.stateid++); st->creatorid = pf_status.hostid; } if (RBT_INSERT(pf_state_tree_id, &tree_id, st) != NULL) { if (pf_status.debug >= LOG_NOTICE) { log(LOG_NOTICE, "pf: state insert failed: " "id: %016llx creatorid: %08x", betoh64(st->id), ntohl(st->creatorid)); addlog("\n"); } pf_detach_state(st); PF_STATE_EXIT_WRITE(); return (-1); } pf_state_list_insert(&pf_state_list, st); pf_status.fcounters[FCNT_STATE_INSERT]++; pf_status.states++; pfi_kif_ref(kif, PFI_KIF_REF_STATE); PF_STATE_EXIT_WRITE(); #if NPFSYNC > 0 pfsync_insert_state(st); #endif /* NPFSYNC > 0 */ *skwp = skw; *sksp = sks; return (0); } struct pf_state * pf_find_state_byid(struct pf_state_cmp *key) { pf_status.fcounters[FCNT_STATE_SEARCH]++; return (RBT_FIND(pf_state_tree_id, &tree_id, (struct pf_state *)key)); } 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] && a->rdomain == b->rdomain) return (0); else { /* mismatch. must not happen. */ if (pf_status.debug >= LOG_ERR) { log(LOG_ERR, "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); addlog(", a1: "); pf_print_host(&a->addr[1], a->port[1], a->af); addlog(", proto=%u", a->proto); addlog(", found af=%u, a0: ", b->af); pf_print_host(&b->addr[0], b->port[0], b->af); addlog(", a1: "); pf_print_host(&b->addr[1], b->port[1], b->af); addlog(", proto=%u", b->proto); addlog("\n"); } return (-1); } } int pf_find_state(struct pf_pdesc *pd, struct pf_state_key_cmp *key, struct pf_state **stp) { struct pf_state_key *sk, *pkt_sk; struct pf_state_item *si; struct pf_state *st = NULL; pf_status.fcounters[FCNT_STATE_SEARCH]++; if (pf_status.debug >= LOG_DEBUG) { log(LOG_DEBUG, "pf: key search, %s on %s: ", pd->dir == PF_OUT ? "out" : "in", pd->kif->pfik_name); pf_print_state_parts(NULL, (struct pf_state_key *)key, NULL); addlog("\n"); } pkt_sk = NULL; sk = NULL; if (pd->dir == PF_OUT) { /* first if block deals with outbound forwarded packet */ pkt_sk = pd->m->m_pkthdr.pf.statekey; if (!pf_state_key_isvalid(pkt_sk)) { pf_mbuf_unlink_state_key(pd->m); pkt_sk = NULL; } if (pkt_sk && pf_state_key_isvalid(pkt_sk->sk_reverse)) sk = pkt_sk->sk_reverse; if (pkt_sk == NULL) { struct inpcb *inp = pd->m->m_pkthdr.pf.inp; /* here we deal with local outbound packet */ if (inp != NULL) { struct pf_state_key *inp_sk; mtx_enter(&pf_inp_mtx); inp_sk = inp->inp_pf_sk; if (pf_state_key_isvalid(inp_sk)) { sk = inp_sk; mtx_leave(&pf_inp_mtx); } else if (inp_sk != NULL) { KASSERT(inp_sk->sk_inp == inp); inp_sk->sk_inp = NULL; inp->inp_pf_sk = NULL; mtx_leave(&pf_inp_mtx); pf_state_key_unref(inp_sk); in_pcbunref(inp); } else mtx_leave(&pf_inp_mtx); } } } if (sk == NULL) { if ((sk = RBT_FIND(pf_state_tree, &pf_statetbl, (struct pf_state_key *)key)) == NULL) return (PF_DROP); if (pd->dir == PF_OUT && pkt_sk && pf_compare_state_keys(pkt_sk, sk, pd->kif, pd->dir) == 0) pf_state_key_link_reverse(sk, pkt_sk); else if (pd->dir == PF_OUT) pf_state_key_link_inpcb(sk, pd->m->m_pkthdr.pf.inp); } /* remove firewall data from outbound packet */ if (pd->dir == PF_OUT) pf_pkt_addr_changed(pd->m); /* list is sorted, if-bound states before floating ones */ TAILQ_FOREACH(si, &sk->sk_states, si_entry) { struct pf_state *sist = si->si_st; if (sist->timeout != PFTM_PURGE && (sist->kif == pfi_all || sist->kif == pd->kif) && ((sist->key[PF_SK_WIRE]->af == sist->key[PF_SK_STACK]->af && sk == (pd->dir == PF_IN ? sist->key[PF_SK_WIRE] : sist->key[PF_SK_STACK])) || (sist->key[PF_SK_WIRE]->af != sist->key[PF_SK_STACK]->af && pd->dir == PF_IN && (sk == sist->key[PF_SK_STACK] || sk == sist->key[PF_SK_WIRE])))) { st = sist; break; } } if (st == NULL) return (PF_DROP); if (ISSET(st->state_flags, PFSTATE_INP_UNLINKED)) return (PF_DROP); if (st->rule.ptr->pktrate.limit && pd->dir == st->direction) { pf_add_threshold(&st->rule.ptr->pktrate); if (pf_check_threshold(&st->rule.ptr->pktrate)) return (PF_DROP); } *stp = st; return (PF_MATCH); } 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 = RBT_FIND(pf_state_tree, &pf_statetbl, (struct pf_state_key *)key); if (sk != NULL) { TAILQ_FOREACH(si, &sk->sk_states, si_entry) { struct pf_state *sist = si->si_st; if (dir == PF_INOUT || (sk == (dir == PF_IN ? sist->key[PF_SK_WIRE] : sist->key[PF_SK_STACK]))) { if (more == NULL) return (sist); if (ret) (*more)++; else ret = si; } } } return (ret ? ret->si_st : NULL); } void pf_state_peer_hton(const struct pf_state_peer *s, struct pfsync_state_peer *d) { d->seqlo = htonl(s->seqlo); d->seqhi = htonl(s->seqhi); d->seqdiff = htonl(s->seqdiff); d->max_win = htons(s->max_win); d->mss = htons(s->mss); d->state = s->state; d->wscale = s->wscale; if (s->scrub) { d->scrub.pfss_flags = htons(s->scrub->pfss_flags & PFSS_TIMESTAMP); d->scrub.pfss_ttl = (s)->scrub->pfss_ttl; d->scrub.pfss_ts_mod = htonl((s)->scrub->pfss_ts_mod); d->scrub.scrub_flag = PFSYNC_SCRUB_FLAG_VALID; } } void pf_state_peer_ntoh(const struct pfsync_state_peer *s, struct pf_state_peer *d) { d->seqlo = ntohl(s->seqlo); d->seqhi = ntohl(s->seqhi); d->seqdiff = ntohl(s->seqdiff); d->max_win = ntohs(s->max_win); d->mss = ntohs(s->mss); d->state = s->state; d->wscale = s->wscale; if (s->scrub.scrub_flag == PFSYNC_SCRUB_FLAG_VALID && d->scrub != NULL) { d->scrub->pfss_flags = ntohs(s->scrub.pfss_flags) & PFSS_TIMESTAMP; d->scrub->pfss_ttl = s->scrub.pfss_ttl; d->scrub->pfss_ts_mod = ntohl(s->scrub.pfss_ts_mod); } } void pf_state_export(struct pfsync_state *sp, struct pf_state *st) { int32_t expire; memset(sp, 0, sizeof(struct pfsync_state)); /* copy from state key */ sp->key[PF_SK_WIRE].addr[0] = st->key[PF_SK_WIRE]->addr[0]; sp->key[PF_SK_WIRE].addr[1] = st->key[PF_SK_WIRE]->addr[1]; sp->key[PF_SK_WIRE].port[0] = st->key[PF_SK_WIRE]->port[0]; sp->key[PF_SK_WIRE].port[1] = st->key[PF_SK_WIRE]->port[1]; sp->key[PF_SK_WIRE].rdomain = htons(st->key[PF_SK_WIRE]->rdomain); sp->key[PF_SK_WIRE].af = st->key[PF_SK_WIRE]->af; sp->key[PF_SK_STACK].addr[0] = st->key[PF_SK_STACK]->addr[0]; sp->key[PF_SK_STACK].addr[1] = st->key[PF_SK_STACK]->addr[1]; sp->key[PF_SK_STACK].port[0] = st->key[PF_SK_STACK]->port[0]; sp->key[PF_SK_STACK].port[1] = st->key[PF_SK_STACK]->port[1]; sp->key[PF_SK_STACK].rdomain = htons(st->key[PF_SK_STACK]->rdomain); sp->key[PF_SK_STACK].af = st->key[PF_SK_STACK]->af; sp->rtableid[PF_SK_WIRE] = htonl(st->rtableid[PF_SK_WIRE]); sp->rtableid[PF_SK_STACK] = htonl(st->rtableid[PF_SK_STACK]); sp->proto = st->key[PF_SK_WIRE]->proto; sp->af = st->key[PF_SK_WIRE]->af; /* copy from state */ strlcpy(sp->ifname, st->kif->pfik_name, sizeof(sp->ifname)); sp->rt = st->rt; sp->rt_addr = st->rt_addr; sp->creation = htonl(getuptime() - st->creation); expire = pf_state_expires(st, st->timeout); if (expire <= getuptime()) sp->expire = htonl(0); else sp->expire = htonl(expire - getuptime()); sp->direction = st->direction; #if NPFLOG > 0 sp->log = st->log; #endif /* NPFLOG > 0 */ sp->timeout = st->timeout; sp->state_flags = htons(st->state_flags); if (READ_ONCE(st->sync_defer) != NULL) sp->state_flags |= htons(PFSTATE_ACK); if (!SLIST_EMPTY(&st->src_nodes)) sp->sync_flags |= PFSYNC_FLAG_SRCNODE; sp->id = st->id; sp->creatorid = st->creatorid; pf_state_peer_hton(&st->src, &sp->src); pf_state_peer_hton(&st->dst, &sp->dst); if (st->rule.ptr == NULL) sp->rule = htonl(-1); else sp->rule = htonl(st->rule.ptr->nr); if (st->anchor.ptr == NULL) sp->anchor = htonl(-1); else sp->anchor = htonl(st->anchor.ptr->nr); sp->nat_rule = htonl(-1); /* left for compat, nat_rule is gone */ pf_state_counter_hton(st->packets[0], sp->packets[0]); pf_state_counter_hton(st->packets[1], sp->packets[1]); pf_state_counter_hton(st->bytes[0], sp->bytes[0]); pf_state_counter_hton(st->bytes[1], sp->bytes[1]); sp->max_mss = htons(st->max_mss); sp->min_ttl = st->min_ttl; sp->set_tos = st->set_tos; sp->set_prio[0] = st->set_prio[0]; sp->set_prio[1] = st->set_prio[1]; } int pf_state_alloc_scrub_memory(const struct pfsync_state_peer *s, struct pf_state_peer *d) { if (s->scrub.scrub_flag && d->scrub == NULL) return (pf_normalize_tcp_alloc(d)); return (0); } #if NPFSYNC > 0 int pf_state_import(const struct pfsync_state *sp, int flags) { struct pf_state *st = NULL; struct pf_state_key *skw = NULL, *sks = NULL; struct pf_rule *r = NULL; struct pfi_kif *kif; int pool_flags; int error = ENOMEM; int n = 0; PF_ASSERT_LOCKED(); if (sp->creatorid == 0) { DPFPRINTF(LOG_NOTICE, "%s: invalid creator id: %08x", __func__, ntohl(sp->creatorid)); return (EINVAL); } if ((kif = pfi_kif_get(sp->ifname, NULL)) == NULL) { DPFPRINTF(LOG_NOTICE, "%s: unknown interface: %s", __func__, sp->ifname); if (flags & PFSYNC_SI_IOCTL) return (EINVAL); return (0); /* skip this state */ } if (sp->af == 0) return (0); /* skip this state */ /* * If the ruleset checksums match or the state is coming from the ioctl, * it's safe to associate the state with the rule of that number. */ if (sp->rule != htonl(-1) && sp->anchor == htonl(-1) && (flags & (PFSYNC_SI_IOCTL | PFSYNC_SI_CKSUM)) && ntohl(sp->rule) < pf_main_ruleset.rules.active.rcount) { TAILQ_FOREACH(r, pf_main_ruleset.rules.active.ptr, entries) if (ntohl(sp->rule) == n++) break; } else r = &pf_default_rule; if ((r->max_states && r->states_cur >= r->max_states)) goto cleanup; if (flags & PFSYNC_SI_IOCTL) pool_flags = PR_WAITOK | PR_LIMITFAIL | PR_ZERO; else pool_flags = PR_NOWAIT | PR_LIMITFAIL | PR_ZERO; if ((st = pool_get(&pf_state_pl, pool_flags)) == NULL) goto cleanup; if ((skw = pf_alloc_state_key(pool_flags)) == NULL) goto cleanup; if ((sp->key[PF_SK_WIRE].af && (sp->key[PF_SK_WIRE].af != sp->key[PF_SK_STACK].af)) || PF_ANEQ(&sp->key[PF_SK_WIRE].addr[0], &sp->key[PF_SK_STACK].addr[0], sp->af) || PF_ANEQ(&sp->key[PF_SK_WIRE].addr[1], &sp->key[PF_SK_STACK].addr[1], sp->af) || sp->key[PF_SK_WIRE].port[0] != sp->key[PF_SK_STACK].port[0] || sp->key[PF_SK_WIRE].port[1] != sp->key[PF_SK_STACK].port[1] || sp->key[PF_SK_WIRE].rdomain != sp->key[PF_SK_STACK].rdomain) { if ((sks = pf_alloc_state_key(pool_flags)) == NULL) goto cleanup; } else sks = pf_state_key_ref(skw); /* allocate memory for scrub info */ if (pf_state_alloc_scrub_memory(&sp->src, &st->src) || pf_state_alloc_scrub_memory(&sp->dst, &st->dst)) goto cleanup; /* copy to state key(s) */ skw->addr[0] = sp->key[PF_SK_WIRE].addr[0]; skw->addr[1] = sp->key[PF_SK_WIRE].addr[1]; skw->port[0] = sp->key[PF_SK_WIRE].port[0]; skw->port[1] = sp->key[PF_SK_WIRE].port[1]; skw->rdomain = ntohs(sp->key[PF_SK_WIRE].rdomain); skw->proto = sp->proto; if (!(skw->af = sp->key[PF_SK_WIRE].af)) skw->af = sp->af; skw->hash = pf_pkt_hash(skw->af, skw->proto, &skw->addr[0], &skw->addr[1], skw->port[0], skw->port[1]); if (sks != skw) { sks->addr[0] = sp->key[PF_SK_STACK].addr[0]; sks->addr[1] = sp->key[PF_SK_STACK].addr[1]; sks->port[0] = sp->key[PF_SK_STACK].port[0]; sks->port[1] = sp->key[PF_SK_STACK].port[1]; sks->rdomain = ntohs(sp->key[PF_SK_STACK].rdomain); if (!(sks->af = sp->key[PF_SK_STACK].af)) sks->af = sp->af; if (sks->af != skw->af) { switch (sp->proto) { case IPPROTO_ICMP: sks->proto = IPPROTO_ICMPV6; break; case IPPROTO_ICMPV6: sks->proto = IPPROTO_ICMP; break; default: sks->proto = sp->proto; } } else sks->proto = sp->proto; if (((sks->af != AF_INET) && (sks->af != AF_INET6)) || ((skw->af != AF_INET) && (skw->af != AF_INET6))) { error = EINVAL; goto cleanup; } sks->hash = pf_pkt_hash(sks->af, sks->proto, &sks->addr[0], &sks->addr[1], sks->port[0], sks->port[1]); } else if ((sks->af != AF_INET) && (sks->af != AF_INET6)) { error = EINVAL; goto cleanup; } st->rtableid[PF_SK_WIRE] = ntohl(sp->rtableid[PF_SK_WIRE]); st->rtableid[PF_SK_STACK] = ntohl(sp->rtableid[PF_SK_STACK]); /* copy to state */ st->rt_addr = sp->rt_addr; st->rt = sp->rt; st->creation = getuptime() - ntohl(sp->creation); st->expire = getuptime(); if (ntohl(sp->expire)) { u_int32_t timeout; timeout = r->timeout[sp->timeout]; if (!timeout) timeout = pf_default_rule.timeout[sp->timeout]; /* sp->expire may have been adaptively scaled by export. */ st->expire -= timeout - ntohl(sp->expire); } st->direction = sp->direction; st->log = sp->log; st->timeout = sp->timeout; st->state_flags = ntohs(sp->state_flags); st->max_mss = ntohs(sp->max_mss); st->min_ttl = sp->min_ttl; st->set_tos = sp->set_tos; st->set_prio[0] = sp->set_prio[0]; st->set_prio[1] = sp->set_prio[1]; st->id = sp->id; st->creatorid = sp->creatorid; pf_state_peer_ntoh(&sp->src, &st->src); pf_state_peer_ntoh(&sp->dst, &st->dst); st->rule.ptr = r; st->anchor.ptr = NULL; PF_REF_INIT(st->refcnt); mtx_init(&st->mtx, IPL_NET); /* XXX when we have anchors, use STATE_INC_COUNTERS */ r->states_cur++; r->states_tot++; st->sync_state = PFSYNC_S_NONE; st->pfsync_time = getuptime(); #if NPFSYNC > 0 pfsync_init_state(st, skw, sks, flags); #endif if (pf_state_insert(kif, &skw, &sks, st) != 0) { /* XXX when we have anchors, use STATE_DEC_COUNTERS */ r->states_cur--; error = EEXIST; goto cleanup_state; } return (0); cleanup: if (skw != NULL) pf_state_key_unref(skw); if (sks != NULL) pf_state_key_unref(sks); cleanup_state: /* pf_state_insert frees the state keys */ if (st) { if (st->dst.scrub) pool_put(&pf_state_scrub_pl, st->dst.scrub); if (st->src.scrub) pool_put(&pf_state_scrub_pl, st->src.scrub); pool_put(&pf_state_pl, st); } return (error); } #endif /* NPFSYNC > 0 */ /* END state table stuff */ void pf_purge_states(void *); struct task pf_purge_states_task = TASK_INITIALIZER(pf_purge_states, NULL); void pf_purge_states_tick(void *); struct timeout pf_purge_states_to = TIMEOUT_INITIALIZER(pf_purge_states_tick, NULL); unsigned int pf_purge_expired_states(unsigned int, unsigned int); /* * how many states to scan this interval. * * this is set when the timeout fires, and reduced by the task. the * task will reschedule itself until the limit is reduced to zero, * and then it adds the timeout again. */ unsigned int pf_purge_states_limit; /* * limit how many states are processed with locks held per run of * the state purge task. */ unsigned int pf_purge_states_collect = 64; void pf_purge_states_tick(void *null) { unsigned int limit = pf_status.states; unsigned int interval = pf_default_rule.timeout[PFTM_INTERVAL]; if (limit == 0) { timeout_add_sec(&pf_purge_states_to, 1); return; } /* * process a fraction of the state table every second */ if (interval > 1) limit /= interval; pf_purge_states_limit = limit; task_add(systqmp, &pf_purge_states_task); } void pf_purge_states(void *null) { unsigned int limit; unsigned int scanned; limit = pf_purge_states_limit; if (limit < pf_purge_states_collect) limit = pf_purge_states_collect; scanned = pf_purge_expired_states(limit, pf_purge_states_collect); if (scanned >= pf_purge_states_limit) { /* we've run out of states to scan this "interval" */ timeout_add_sec(&pf_purge_states_to, 1); return; } pf_purge_states_limit -= scanned; task_add(systqmp, &pf_purge_states_task); } void pf_purge_tick(void *); struct timeout pf_purge_to = TIMEOUT_INITIALIZER(pf_purge_tick, NULL); void pf_purge(void *); struct task pf_purge_task = TASK_INITIALIZER(pf_purge, NULL); void pf_purge_tick(void *null) { task_add(systqmp, &pf_purge_task); } void pf_purge(void *null) { unsigned int interval = max(1, pf_default_rule.timeout[PFTM_INTERVAL]); PF_LOCK(); pf_purge_expired_src_nodes(); PF_UNLOCK(); /* * Fragments don't require PF_LOCK(), they use their own lock. */ pf_purge_expired_fragments(); /* interpret the interval as idle time between runs */ timeout_add_sec(&pf_purge_to, interval); } int32_t pf_state_expires(const struct pf_state *st, uint8_t stimeout) { u_int32_t timeout; u_int32_t start; u_int32_t end; u_int32_t states; /* * pf_state_expires is used by the state purge task to * decide if a state is a candidate for cleanup, and by the * pfsync state export code to populate an expiry time. * * this function may be called by the state purge task while * the state is being modified. avoid inconsistent reads of * state->timeout by having the caller do the read (and any * checks it needs to do on the same variable) and then pass * their view of the timeout in here for this function to use. * the only consequence of using a stale timeout value is * that the state won't be a candidate for purging until the * next pass of the purge task. */ /* handle all PFTM_* >= PFTM_MAX here */ if (stimeout >= PFTM_MAX) return (0); KASSERT(stimeout < PFTM_MAX); timeout = st->rule.ptr->timeout[stimeout]; if (!timeout) timeout = pf_default_rule.timeout[stimeout]; start = st->rule.ptr->timeout[PFTM_ADAPTIVE_START]; if (start) { end = st->rule.ptr->timeout[PFTM_ADAPTIVE_END]; states = st->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 (0); timeout = (u_int64_t)timeout * (end - states) / (end - start); } return (st->expire + timeout); } void pf_purge_expired_src_nodes(void) { struct pf_src_node *cur, *next; PF_ASSERT_LOCKED(); RB_FOREACH_SAFE(cur, pf_src_tree, &tree_src_tracking, next) { if (cur->states == 0 && cur->expire <= getuptime()) { pf_remove_src_node(cur); } } } void pf_src_tree_remove_state(struct pf_state *st) { u_int32_t timeout; struct pf_sn_item *sni; while ((sni = SLIST_FIRST(&st->src_nodes)) != NULL) { SLIST_REMOVE_HEAD(&st->src_nodes, next); if (st->src.tcp_est) --sni->sn->conn; if (--sni->sn->states == 0) { timeout = st->rule.ptr->timeout[PFTM_SRC_NODE]; if (!timeout) timeout = pf_default_rule.timeout[PFTM_SRC_NODE]; sni->sn->expire = getuptime() + timeout; } pool_put(&pf_sn_item_pl, sni); } } void pf_remove_state(struct pf_state *st) { PF_ASSERT_LOCKED(); mtx_enter(&st->mtx); if (st->timeout == PFTM_UNLINKED) { mtx_leave(&st->mtx); return; } st->timeout = PFTM_UNLINKED; mtx_leave(&st->mtx); /* handle load balancing related tasks */ pf_postprocess_addr(st); if (st->src.state == PF_TCPS_PROXY_DST) { pf_send_tcp(st->rule.ptr, st->key[PF_SK_WIRE]->af, &st->key[PF_SK_WIRE]->addr[1], &st->key[PF_SK_WIRE]->addr[0], st->key[PF_SK_WIRE]->port[1], st->key[PF_SK_WIRE]->port[0], st->src.seqhi, st->src.seqlo + 1, TH_RST|TH_ACK, 0, 0, 0, 1, st->tag, st->key[PF_SK_WIRE]->rdomain); } if (st->key[PF_SK_STACK]->proto == IPPROTO_TCP) pf_set_protostate(st, PF_PEER_BOTH, TCPS_CLOSED); RBT_REMOVE(pf_state_tree_id, &tree_id, st); #if NPFLOW > 0 if (st->state_flags & PFSTATE_PFLOW) export_pflow(st); #endif /* NPFLOW > 0 */ #if NPFSYNC > 0 pfsync_delete_state(st); #endif /* NPFSYNC > 0 */ pf_src_tree_remove_state(st); pf_detach_state(st); } void pf_remove_divert_state(struct inpcb *inp) { struct pf_state_key *sk; struct pf_state_item *si; PF_ASSERT_UNLOCKED(); if (READ_ONCE(inp->inp_pf_sk) == NULL) return; mtx_enter(&pf_inp_mtx); sk = pf_state_key_ref(inp->inp_pf_sk); mtx_leave(&pf_inp_mtx); if (sk == NULL) return; PF_LOCK(); PF_STATE_ENTER_WRITE(); TAILQ_FOREACH(si, &sk->sk_states, si_entry) { struct pf_state *sist = si->si_st; if (sk == sist->key[PF_SK_STACK] && sist->rule.ptr && (sist->rule.ptr->divert.type == PF_DIVERT_TO || sist->rule.ptr->divert.type == PF_DIVERT_REPLY)) { if (sist->key[PF_SK_STACK]->proto == IPPROTO_TCP && sist->key[PF_SK_WIRE] != sist->key[PF_SK_STACK]) { /* * If the local address is translated, keep * the state for "tcp.closed" seconds to * prevent its source port from being reused. */ if (sist->src.state < TCPS_FIN_WAIT_2 || sist->dst.state < TCPS_FIN_WAIT_2) { pf_set_protostate(sist, PF_PEER_BOTH, TCPS_TIME_WAIT); pf_update_state_timeout(sist, PFTM_TCP_CLOSED); sist->expire = getuptime(); } sist->state_flags |= PFSTATE_INP_UNLINKED; } else pf_remove_state(sist); break; } } PF_STATE_EXIT_WRITE(); PF_UNLOCK(); pf_state_key_unref(sk); } void pf_free_state(struct pf_state *st) { struct pf_rule_item *ri; PF_ASSERT_LOCKED(); #if NPFSYNC > 0 if (pfsync_state_in_use(st)) return; #endif /* NPFSYNC > 0 */ KASSERT(st->timeout == PFTM_UNLINKED); if (--st->rule.ptr->states_cur == 0 && st->rule.ptr->src_nodes == 0) pf_rm_rule(NULL, st->rule.ptr); if (st->anchor.ptr != NULL) if (--st->anchor.ptr->states_cur == 0) pf_rm_rule(NULL, st->anchor.ptr); while ((ri = SLIST_FIRST(&st->match_rules))) { SLIST_REMOVE_HEAD(&st->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(st); pfi_kif_unref(st->kif, PFI_KIF_REF_STATE); pf_state_list_remove(&pf_state_list, st); if (st->tag) pf_tag_unref(st->tag); pf_state_unref(st); pf_status.fcounters[FCNT_STATE_REMOVALS]++; pf_status.states--; } unsigned int pf_purge_expired_states(const unsigned int limit, const unsigned int collect) { /* * this task/thread/context/whatever is the only thing that * removes states from the pf_state_list, so the cur reference * it holds between calls is guaranteed to still be in the * list. */ static struct pf_state *cur = NULL; struct pf_state *head, *tail; struct pf_state *st; SLIST_HEAD(pf_state_gcl, pf_state) gcl = SLIST_HEAD_INITIALIZER(gcl); time_t now; unsigned int scanned; unsigned int collected = 0; PF_ASSERT_UNLOCKED(); rw_enter_read(&pf_state_list.pfs_rwl); mtx_enter(&pf_state_list.pfs_mtx); head = TAILQ_FIRST(&pf_state_list.pfs_list); tail = TAILQ_LAST(&pf_state_list.pfs_list, pf_state_queue); mtx_leave(&pf_state_list.pfs_mtx); if (head == NULL) { /* the list is empty */ rw_exit_read(&pf_state_list.pfs_rwl); return (limit); } /* (re)start at the front of the list */ if (cur == NULL) cur = head; now = getuptime(); for (scanned = 0; scanned < limit; scanned++) { uint8_t stimeout = cur->timeout; unsigned int limited = 0; if ((stimeout == PFTM_UNLINKED) || (pf_state_expires(cur, stimeout) <= now)) { st = pf_state_ref(cur); SLIST_INSERT_HEAD(&gcl, st, gc_list); if (++collected >= collect) limited = 1; } /* don't iterate past the end of our view of the list */ if (cur == tail) { cur = NULL; break; } cur = TAILQ_NEXT(cur, entry_list); /* don't spend too much time here. */ if (ISSET(READ_ONCE(curcpu()->ci_schedstate.spc_schedflags), SPCF_SHOULDYIELD) || limited) break; } rw_exit_read(&pf_state_list.pfs_rwl); if (SLIST_EMPTY(&gcl)) return (scanned); rw_enter_write(&pf_state_list.pfs_rwl); PF_LOCK(); PF_STATE_ENTER_WRITE(); SLIST_FOREACH(st, &gcl, gc_list) { if (st->timeout != PFTM_UNLINKED) pf_remove_state(st); pf_free_state(st); } PF_STATE_EXIT_WRITE(); PF_UNLOCK(); rw_exit_write(&pf_state_list.pfs_rwl); while ((st = SLIST_FIRST(&gcl)) != NULL) { SLIST_REMOVE_HEAD(&gcl, gc_list); pf_state_unref(st); } return (scanned); } int pf_tbladdr_setup(struct pf_ruleset *rs, struct pf_addr_wrap *aw, int wait) { if (aw->type != PF_ADDR_TABLE) return (0); if ((aw->p.tbl = pfr_attach_table(rs, aw->v.tblname, wait)) == 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) { case AF_INET: { u_int32_t a = ntohl(addr->addr32[0]); addlog("%u.%u.%u.%u", (a>>24)&255, (a>>16)&255, (a>>8)&255, a&255); if (p) { p = ntohs(p); addlog(":%u", p); } break; } #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) addlog(":"); if (i == maxend) addlog(":"); } else { b = ntohs(addr->addr16[i]); addlog("%x", b); if (i < 7) addlog(":"); } } if (p) { p = ntohs(p); addlog("[%u]", p); } break; } #endif /* INET6 */ } } void pf_print_state(struct pf_state *st) { pf_print_state_parts(st, NULL, NULL); } void pf_print_state_parts(struct pf_state *st, 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 : (st ? st->key[PF_SK_WIRE] : NULL); sks = sksp ? sksp : (st ? st->key[PF_SK_STACK] : NULL); proto = skw ? skw->proto : (sks ? sks->proto : 0); dir = st ? st->direction : 0; switch (proto) { case IPPROTO_IPV4: addlog("IPv4"); break; case IPPROTO_IPV6: addlog("IPv6"); break; case IPPROTO_TCP: addlog("TCP"); break; case IPPROTO_UDP: addlog("UDP"); break; case IPPROTO_ICMP: addlog("ICMP"); break; case IPPROTO_ICMPV6: addlog("ICMPv6"); break; default: addlog("%u", proto); break; } switch (dir) { case PF_IN: addlog(" in"); break; case PF_OUT: addlog(" out"); break; } if (skw) { addlog(" wire: (%d) ", skw->rdomain); pf_print_host(&skw->addr[0], skw->port[0], skw->af); addlog(" "); pf_print_host(&skw->addr[1], skw->port[1], skw->af); } if (sks) { addlog(" stack: (%d) ", sks->rdomain); if (sks != skw) { pf_print_host(&sks->addr[0], sks->port[0], sks->af); addlog(" "); pf_print_host(&sks->addr[1], sks->port[1], sks->af); } else addlog("-"); } if (st) { if (proto == IPPROTO_TCP) { addlog(" [lo=%u high=%u win=%u modulator=%u", st->src.seqlo, st->src.seqhi, st->src.max_win, st->src.seqdiff); if (st->src.wscale && st->dst.wscale) addlog(" wscale=%u", st->src.wscale & PF_WSCALE_MASK); addlog("]"); addlog(" [lo=%u high=%u win=%u modulator=%u", st->dst.seqlo, st->dst.seqhi, st->dst.max_win, st->dst.seqdiff); if (st->src.wscale && st->dst.wscale) addlog(" wscale=%u", st->dst.wscale & PF_WSCALE_MASK); addlog("]"); } addlog(" %u:%u", st->src.state, st->dst.state); if (st->rule.ptr) addlog(" @%d", st->rule.ptr->nr); } } void pf_print_flags(u_int8_t f) { if (f) addlog(" "); if (f & TH_FIN) addlog("F"); if (f & TH_SYN) addlog("S"); if (f & TH_RST) addlog("R"); if (f & TH_PUSH) addlog("P"); if (f & TH_ACK) addlog("A"); if (f & TH_URG) addlog("U"); if (f & TH_ECE) addlog("E"); if (f & TH_CWR) addlog("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->onrdomain != prev->onrdomain || cur->ifnot != prev->ifnot) PF_SET_SKIP_STEPS(PF_SKIP_RDOM); 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->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->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.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, AF_INET6)) return (1); if (PF_ANEQ(&aw1->v.a.mask, &aw2->v.a.mask, AF_INET6)) return (1); return (0); case PF_ADDR_DYNIFTL: return (aw1->p.dyn->pfid_kt != aw2->p.dyn->pfid_kt); case PF_ADDR_NONE: 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: addlog("invalid address type: %d\n", aw1->type); return (1); } } /* This algorithm computes 'a + b - c' in ones-complement using a trick to * emulate at most one ones-complement subtraction. This thereby limits net * carries/borrows to at most one, eliminating a reduction step and saving one * each of +, >>, & and ~. * * def. x mod y = x - (x//y)*y for integer x,y * def. sum = x mod 2^16 * def. accumulator = (x >> 16) mod 2^16 * * The trick works as follows: subtracting exactly one u_int16_t from the * u_int32_t x incurs at most one underflow, wrapping its upper 16-bits, the * accumulator, to 2^16 - 1. Adding this to the 16-bit sum preserves the * ones-complement borrow: * * (sum + accumulator) mod 2^16 * = { assume underflow: accumulator := 2^16 - 1 } * (sum + 2^16 - 1) mod 2^16 * = { mod } * (sum - 1) mod 2^16 * * Although this breaks for sum = 0, giving 0xffff, which is ones-complement's * other zero, not -1, that cannot occur: the 16-bit sum cannot be underflown * to zero as that requires subtraction of at least 2^16, which exceeds a * single u_int16_t's range. * * We use the following theorem to derive the implementation: * * th. (x + (y mod z)) mod z = (x + y) mod z (0) * proof. * (x + (y mod z)) mod z * = { def mod } * (x + y - (y//z)*z) mod z * = { (a + b*c) mod c = a mod c } * (x + y) mod z [end of proof] * * ... and thereby obtain: * * (sum + accumulator) mod 2^16 * = { def. accumulator, def. sum } * (x mod 2^16 + (x >> 16) mod 2^16) mod 2^16 * = { (0), twice } * (x + (x >> 16)) mod 2^16 * = { x mod 2^n = x & (2^n - 1) } * (x + (x >> 16)) & 0xffff * * Note: this serves also as a reduction step for at most one add (as the * trailing mod 2^16 prevents further reductions by destroying carries). */ __inline void pf_cksum_fixup(u_int16_t *cksum, u_int16_t was, u_int16_t now, u_int8_t proto) { u_int32_t x; const int udp = proto == IPPROTO_UDP; x = *cksum + was - now; x = (x + (x >> 16)) & 0xffff; /* optimise: eliminate a branch when not udp */ if (udp && *cksum == 0x0000) return; if (udp && x == 0x0000) x = 0xffff; *cksum = (u_int16_t)(x); } #ifdef INET6 /* pre: coverage(cksum) is superset of coverage(covered_cksum) */ static __inline void pf_cksum_uncover(u_int16_t *cksum, u_int16_t covered_cksum, u_int8_t proto) { pf_cksum_fixup(cksum, ~covered_cksum, 0x0, proto); } /* pre: disjoint(coverage(cksum), coverage(uncovered_cksum)) */ static __inline void pf_cksum_cover(u_int16_t *cksum, u_int16_t uncovered_cksum, u_int8_t proto) { pf_cksum_fixup(cksum, 0x0, ~uncovered_cksum, proto); } #endif /* INET6 */ /* pre: *a is 16-bit aligned within its packet * * This algorithm emulates 16-bit ones-complement sums on a twos-complement * machine by conserving ones-complement's otherwise discarded carries in the * upper bits of x. These accumulated carries when added to the lower 16-bits * over at least zero 'reduction' steps then complete the ones-complement sum. * * def. sum = x mod 2^16 * def. accumulator = (x >> 16) * * At most two reduction steps * * x := sum + accumulator * = { def sum, def accumulator } * x := x mod 2^16 + (x >> 16) * = { x mod 2^n = x & (2^n - 1) } * x := (x & 0xffff) + (x >> 16) * * are necessary to incorporate the accumulated carries (at most one per add) * i.e. to reduce x < 2^16 from at most 16 carries in the upper 16 bits. * * The function is also invariant over the endian of the host. Why? * * Define the unary transpose operator ~ on a bitstring in python slice * notation as lambda m: m[P:] + m[:P] , for some constant pivot P. * * th. ~ distributes over ones-complement addition, denoted by +_1, i.e. * * ~m +_1 ~n = ~(m +_1 n) (for all bitstrings m,n of equal length) * * proof. Regard the bitstrings in m +_1 n as split at P, forming at most two * 'half-adds'. Under ones-complement addition, each half-add carries to the * other, so the sum of each half-add is unaffected by their relative * order. Therefore: * * ~m +_1 ~n * = { half-adds invariant under transposition } * ~s * = { substitute } * ~(m +_1 n) [end of proof] * * th. Summing two in-memory ones-complement 16-bit variables m,n on a machine * with the converse endian does not alter the result. * * proof. * { converse machine endian: load/store transposes, P := 8 } * ~(~m +_1 ~n) * = { ~ over +_1 } * ~~m +_1 ~~n * = { ~ is an involution } * m +_1 n [end of proof] * */ #define NEG(x) ((u_int16_t)~(x)) void pf_cksum_fixup_a(u_int16_t *cksum, const struct pf_addr *a, const struct pf_addr *an, sa_family_t af, u_int8_t proto) { u_int32_t x; const u_int16_t *n = an->addr16; const u_int16_t *o = a->addr16; const int udp = proto == IPPROTO_UDP; switch (af) { case AF_INET: x = *cksum + o[0] + NEG(n[0]) + o[1] + NEG(n[1]); break; #ifdef INET6 case AF_INET6: x = *cksum + o[0] + NEG(n[0]) + o[1] + NEG(n[1]) +\ o[2] + NEG(n[2]) + o[3] + NEG(n[3]) +\ o[4] + NEG(n[4]) + o[5] + NEG(n[5]) +\ o[6] + NEG(n[6]) + o[7] + NEG(n[7]); break; #endif /* INET6 */ default: unhandled_af(af); } x = (x & 0xffff) + (x >> 16); x = (x & 0xffff) + (x >> 16); /* optimise: eliminate a branch when not udp */ if (udp && *cksum == 0x0000) return; if (udp && x == 0x0000) x = 0xffff; *cksum = (u_int16_t)(x); } int pf_patch_8(struct pf_pdesc *pd, u_int8_t *f, u_int8_t v, bool hi) { int rewrite = 0; if (*f != v) { u_int16_t old = htons(hi ? (*f << 8) : *f); u_int16_t new = htons(hi ? ( v << 8) : v); pf_cksum_fixup(pd->pcksum, old, new, pd->proto); *f = v; rewrite = 1; } return (rewrite); } /* pre: *f is 16-bit aligned within its packet */ int pf_patch_16(struct pf_pdesc *pd, u_int16_t *f, u_int16_t v) { int rewrite = 0; if (*f != v) { pf_cksum_fixup(pd->pcksum, *f, v, pd->proto); *f = v; rewrite = 1; } return (rewrite); } int pf_patch_16_unaligned(struct pf_pdesc *pd, void *f, u_int16_t v, bool hi) { int rewrite = 0; u_int8_t *fb = (u_int8_t*)f; u_int8_t *vb = (u_int8_t*)&v; if (hi && ALIGNED_POINTER(f, u_int16_t)) { return (pf_patch_16(pd, f, v)); /* optimise */ } rewrite += pf_patch_8(pd, fb++, *vb++, hi); rewrite += pf_patch_8(pd, fb++, *vb++,!hi); return (rewrite); } /* pre: *f is 16-bit aligned within its packet */ /* pre: pd->proto != IPPROTO_UDP */ int pf_patch_32(struct pf_pdesc *pd, u_int32_t *f, u_int32_t v) { int rewrite = 0; u_int16_t *pc = pd->pcksum; u_int8_t proto = pd->proto; /* optimise: inline udp fixup code is unused; let compiler scrub it */ if (proto == IPPROTO_UDP) panic("%s: udp", __func__); /* optimise: skip *f != v guard; true for all use-cases */ pf_cksum_fixup(pc, *f / (1 << 16), v / (1 << 16), proto); pf_cksum_fixup(pc, *f % (1 << 16), v % (1 << 16), proto); *f = v; rewrite = 1; return (rewrite); } int pf_patch_32_unaligned(struct pf_pdesc *pd, void *f, u_int32_t v, bool hi) { int rewrite = 0; u_int8_t *fb = (u_int8_t*)f; u_int8_t *vb = (u_int8_t*)&v; if (hi && ALIGNED_POINTER(f, u_int32_t)) { return (pf_patch_32(pd, f, v)); /* optimise */ } rewrite += pf_patch_8(pd, fb++, *vb++, hi); rewrite += pf_patch_8(pd, fb++, *vb++,!hi); rewrite += pf_patch_8(pd, fb++, *vb++, hi); rewrite += pf_patch_8(pd, fb++, *vb++,!hi); return (rewrite); } int pf_icmp_mapping(struct pf_pdesc *pd, u_int8_t type, int *icmp_dir, u_int16_t *virtual_id, u_int16_t *virtual_type) { /* * 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; /* Queries (and responses) */ switch (pd->af) { case AF_INET: switch (type) { case ICMP_ECHO: *icmp_dir = PF_IN; /* FALLTHROUGH */ case ICMP_ECHOREPLY: *virtual_type = ICMP_ECHO; *virtual_id = pd->hdr.icmp.icmp_id; break; case ICMP_TSTAMP: *icmp_dir = PF_IN; /* FALLTHROUGH */ case ICMP_TSTAMPREPLY: *virtual_type = ICMP_TSTAMP; *virtual_id = pd->hdr.icmp.icmp_id; break; case ICMP_IREQ: *icmp_dir = PF_IN; /* FALLTHROUGH */ case ICMP_IREQREPLY: *virtual_type = ICMP_IREQ; *virtual_id = pd->hdr.icmp.icmp_id; break; case ICMP_MASKREQ: *icmp_dir = PF_IN; /* FALLTHROUGH */ case ICMP_MASKREPLY: *virtual_type = ICMP_MASKREQ; *virtual_id = pd->hdr.icmp.icmp_id; break; case ICMP_IPV6_WHEREAREYOU: *icmp_dir = PF_IN; /* FALLTHROUGH */ case ICMP_IPV6_IAMHERE: *virtual_type = ICMP_IPV6_WHEREAREYOU; *virtual_id = 0; /* Nothing sane to match on! */ break; case ICMP_MOBILE_REGREQUEST: *icmp_dir = PF_IN; /* FALLTHROUGH */ case ICMP_MOBILE_REGREPLY: *virtual_type = ICMP_MOBILE_REGREQUEST; *virtual_id = 0; /* Nothing sane to match on! */ break; case ICMP_ROUTERSOLICIT: *icmp_dir = PF_IN; /* FALLTHROUGH */ case ICMP_ROUTERADVERT: *virtual_type = ICMP_ROUTERSOLICIT; *virtual_id = 0; /* Nothing sane to match on! */ break; /* These ICMP types map to other connections */ case ICMP_UNREACH: case ICMP_SOURCEQUENCH: case ICMP_REDIRECT: case ICMP_TIMXCEED: case ICMP_PARAMPROB: /* These will not be used, but set them anyway */ *icmp_dir = PF_IN; *virtual_type = htons(type); *virtual_id = 0; return (1); /* These types match to another state */ /* * All remaining ICMP types get their own states, * and will only match in one direction. */ default: *icmp_dir = PF_IN; *virtual_type = type; *virtual_id = 0; break; } break; #ifdef INET6 case AF_INET6: switch (type) { case ICMP6_ECHO_REQUEST: *icmp_dir = PF_IN; /* FALLTHROUGH */ case ICMP6_ECHO_REPLY: *virtual_type = ICMP6_ECHO_REQUEST; *virtual_id = pd->hdr.icmp6.icmp6_id; break; case MLD_LISTENER_QUERY: case MLD_LISTENER_REPORT: { struct mld_hdr *mld = &pd->hdr.mld; u_int32_t h; /* * Listener Report can be sent by clients * without an associated Listener Query. * In addition to that, when Report is sent as a * reply to a Query its source and destination * address are different. */ *icmp_dir = PF_IN; *virtual_type = MLD_LISTENER_QUERY; /* generate fake id for these messages */ h = mld->mld_addr.s6_addr32[0] ^ mld->mld_addr.s6_addr32[1] ^ mld->mld_addr.s6_addr32[2] ^ mld->mld_addr.s6_addr32[3]; *virtual_id = (h >> 16) ^ (h & 0xffff); break; } /* * ICMP6_FQDN and ICMP6_NI query/reply are the same type as * ICMP6_WRU */ case ICMP6_WRUREQUEST: *icmp_dir = PF_IN; /* FALLTHROUGH */ case ICMP6_WRUREPLY: *virtual_type = ICMP6_WRUREQUEST; *virtual_id = 0; /* Nothing sane to match on! */ break; case MLD_MTRACE: *icmp_dir = PF_IN; /* FALLTHROUGH */ case MLD_MTRACE_RESP: *virtual_type = MLD_MTRACE; *virtual_id = 0; /* Nothing sane to match on! */ break; case ND_NEIGHBOR_SOLICIT: *icmp_dir = PF_IN; /* FALLTHROUGH */ case ND_NEIGHBOR_ADVERT: { struct nd_neighbor_solicit *nd = &pd->hdr.nd_ns; u_int32_t h; *virtual_type = ND_NEIGHBOR_SOLICIT; /* generate fake id for these messages */ h = 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]; *virtual_id = (h >> 16) ^ (h & 0xffff); /* * the extra work here deals with 'keep state' option * at pass rule for unsolicited advertisement. By * returning 1 (state_icmp = 1) we override 'keep * state' to 'no state' so we don't create state for * unsolicited advertisements. No one expects answer to * unsolicited advertisements so we should be good. */ if (type == ND_NEIGHBOR_ADVERT) { *virtual_type = htons(*virtual_type); return (1); } break; } /* * These ICMP types map to other connections. * ND_REDIRECT can't be in this list because the triggering * packet header is optional. */ case ICMP6_DST_UNREACH: case ICMP6_PACKET_TOO_BIG: case ICMP6_TIME_EXCEEDED: case ICMP6_PARAM_PROB: /* These will not be used, but set them anyway */ *icmp_dir = PF_IN; *virtual_type = htons(type); *virtual_id = 0; return (1); /* These types match to another state */ /* * All remaining ICMP6 types get their own states, * and will only match in one direction. */ default: *icmp_dir = PF_IN; *virtual_type = type; *virtual_id = 0; break; } break; #endif /* INET6 */ } *virtual_type = htons(*virtual_type); return (0); /* These types match to their own state */ } void pf_translate_icmp(struct pf_pdesc *pd, struct pf_addr *qa, u_int16_t *qp, struct pf_addr *oa, struct pf_addr *na, u_int16_t np) { /* note: doesn't trouble to fixup quoted checksums, if any */ /* change quoted protocol port */ if (qp != NULL) pf_patch_16(pd, qp, np); /* change quoted ip address */ pf_cksum_fixup_a(pd->pcksum, qa, na, pd->af, pd->proto); pf_addrcpy(qa, na, pd->af); /* change network-header's ip address */ if (oa) pf_translate_a(pd, oa, na); } /* pre: *a is 16-bit aligned within its packet */ /* *a is a network header src/dst address */ int pf_translate_a(struct pf_pdesc *pd, struct pf_addr *a, struct pf_addr *an) { int rewrite = 0; /* warning: !PF_ANEQ != PF_AEQ */ if (!PF_ANEQ(a, an, pd->af)) return (0); /* fixup transport pseudo-header, if any */ switch (pd->proto) { case IPPROTO_TCP: /* FALLTHROUGH */ case IPPROTO_UDP: /* FALLTHROUGH */ case IPPROTO_ICMPV6: pf_cksum_fixup_a(pd->pcksum, a, an, pd->af, pd->proto); break; default: break; /* assume no pseudo-header */ } pf_addrcpy(a, an, pd->af); rewrite = 1; return (rewrite); } #ifdef INET6 /* pf_translate_af() may change pd->m, adjust local copies after calling */ int pf_translate_af(struct pf_pdesc *pd) { static const struct pf_addr zero; struct ip *ip4; struct ip6_hdr *ip6; int copyback = 0; u_int hlen, ohlen, dlen; u_int16_t *pc; u_int8_t af_proto, naf_proto; hlen = (pd->naf == AF_INET) ? sizeof(*ip4) : sizeof(*ip6); ohlen = pd->off; dlen = pd->tot_len - pd->off; pc = pd->pcksum; af_proto = naf_proto = pd->proto; if (naf_proto == IPPROTO_ICMP) af_proto = IPPROTO_ICMPV6; if (naf_proto == IPPROTO_ICMPV6) af_proto = IPPROTO_ICMP; /* uncover stale pseudo-header */ switch (af_proto) { case IPPROTO_ICMPV6: /* optimise: unchanged for TCP/UDP */ pf_cksum_fixup(pc, htons(af_proto), 0x0, af_proto); pf_cksum_fixup(pc, htons(dlen), 0x0, af_proto); /* FALLTHROUGH */ case IPPROTO_UDP: /* FALLTHROUGH */ case IPPROTO_TCP: pf_cksum_fixup_a(pc, pd->src, &zero, pd->af, af_proto); pf_cksum_fixup_a(pc, pd->dst, &zero, pd->af, af_proto); copyback = 1; break; default: break; /* assume no pseudo-header */ } /* replace the network header */ m_adj(pd->m, pd->off); pd->src = NULL; pd->dst = NULL; if ((M_PREPEND(pd->m, hlen, M_DONTWAIT)) == NULL) { pd->m = NULL; return (-1); } pd->off = hlen; pd->tot_len += hlen - ohlen; switch (pd->naf) { case AF_INET: ip4 = mtod(pd->m, struct ip *); memset(ip4, 0, hlen); ip4->ip_v = IPVERSION; ip4->ip_hl = hlen >> 2; ip4->ip_tos = pd->tos; ip4->ip_len = htons(hlen + dlen); ip4->ip_id = htons(ip_randomid()); ip4->ip_off = htons(IP_DF); ip4->ip_ttl = pd->ttl; ip4->ip_p = pd->proto; ip4->ip_src = pd->nsaddr.v4; ip4->ip_dst = pd->ndaddr.v4; break; case AF_INET6: ip6 = mtod(pd->m, struct ip6_hdr *); memset(ip6, 0, hlen); ip6->ip6_vfc = IPV6_VERSION; ip6->ip6_flow |= htonl((u_int32_t)pd->tos << 20); ip6->ip6_plen = htons(dlen); ip6->ip6_nxt = pd->proto; if (!pd->ttl || pd->ttl > IPV6_DEFHLIM) ip6->ip6_hlim = IPV6_DEFHLIM; else ip6->ip6_hlim = pd->ttl; ip6->ip6_src = pd->nsaddr.v6; ip6->ip6_dst = pd->ndaddr.v6; break; default: unhandled_af(pd->naf); } /* UDP over IPv6 must be checksummed per rfc2460 p27 */ if (naf_proto == IPPROTO_UDP && *pc == 0x0000 && pd->naf == AF_INET6) { pd->m->m_pkthdr.csum_flags |= M_UDP_CSUM_OUT; } /* cover fresh pseudo-header */ switch (naf_proto) { case IPPROTO_ICMPV6: /* optimise: unchanged for TCP/UDP */ pf_cksum_fixup(pc, 0x0, htons(naf_proto), naf_proto); pf_cksum_fixup(pc, 0x0, htons(dlen), naf_proto); /* FALLTHROUGH */ case IPPROTO_UDP: /* FALLTHROUGH */ case IPPROTO_TCP: pf_cksum_fixup_a(pc, &zero, &pd->nsaddr, pd->naf, naf_proto); pf_cksum_fixup_a(pc, &zero, &pd->ndaddr, pd->naf, naf_proto); copyback = 1; break; default: break; /* assume no pseudo-header */ } /* flush pd->pcksum */ if (copyback) m_copyback(pd->m, pd->off, pd->hdrlen, &pd->hdr, M_NOWAIT); return (0); } int pf_change_icmp_af(struct mbuf *m, int ipoff2, struct pf_pdesc *pd, struct pf_pdesc *pd2, struct pf_addr *src, struct pf_addr *dst, sa_family_t af, sa_family_t naf) { struct mbuf *n = NULL; struct ip *ip4; struct ip6_hdr *ip6; u_int hlen, ohlen, dlen; int d; if (af == naf || (af != AF_INET && af != AF_INET6) || (naf != AF_INET && naf != AF_INET6)) return (-1); /* split the mbuf chain on the quoted ip/ip6 header boundary */ if ((n = m_split(m, ipoff2, M_DONTWAIT)) == NULL) return (-1); /* new quoted header */ hlen = naf == AF_INET ? sizeof(*ip4) : sizeof(*ip6); /* old quoted header */ ohlen = pd2->off - ipoff2; /* trim old quoted header */ pf_cksum_uncover(pd->pcksum, in_cksum(n, ohlen), pd->proto); m_adj(n, ohlen); /* prepend a new, translated, quoted header */ if ((M_PREPEND(n, hlen, M_DONTWAIT)) == NULL) return (-1); switch (naf) { case AF_INET: ip4 = mtod(n, struct ip *); memset(ip4, 0, sizeof(*ip4)); ip4->ip_v = IPVERSION; ip4->ip_hl = sizeof(*ip4) >> 2; ip4->ip_len = htons(sizeof(*ip4) + pd2->tot_len - ohlen); ip4->ip_id = htons(ip_randomid()); ip4->ip_off = htons(IP_DF); ip4->ip_ttl = pd2->ttl; if (pd2->proto == IPPROTO_ICMPV6) ip4->ip_p = IPPROTO_ICMP; else ip4->ip_p = pd2->proto; ip4->ip_src = src->v4; ip4->ip_dst = dst->v4; in_hdr_cksum_out(n, NULL); break; case AF_INET6: ip6 = mtod(n, struct ip6_hdr *); memset(ip6, 0, sizeof(*ip6)); ip6->ip6_vfc = IPV6_VERSION; ip6->ip6_plen = htons(pd2->tot_len - ohlen); if (pd2->proto == IPPROTO_ICMP) ip6->ip6_nxt = IPPROTO_ICMPV6; else ip6->ip6_nxt = pd2->proto; if (!pd2->ttl || pd2->ttl > IPV6_DEFHLIM) ip6->ip6_hlim = IPV6_DEFHLIM; else ip6->ip6_hlim = pd2->ttl; ip6->ip6_src = src->v6; ip6->ip6_dst = dst->v6; break; } /* cover new quoted header */ /* optimise: any new AF_INET header of ours sums to zero */ if (naf != AF_INET) { pf_cksum_cover(pd->pcksum, in_cksum(n, hlen), pd->proto); } /* reattach modified quoted packet to outer header */ { int nlen = n->m_pkthdr.len; m_cat(m, n); m->m_pkthdr.len += nlen; } /* account for altered length */ d = hlen - ohlen; if (pd->proto == IPPROTO_ICMPV6) { /* fixup pseudo-header */ dlen = pd->tot_len - pd->off; pf_cksum_fixup(pd->pcksum, htons(dlen), htons(dlen + d), pd->proto); } pd->tot_len += d; pd2->tot_len += d; pd2->off += d; /* note: not bothering to update network headers as these due for rewrite by pf_translate_af() */ return (0); } #define PTR_IP(field) (offsetof(struct ip, field)) #define PTR_IP6(field) (offsetof(struct ip6_hdr, field)) int pf_translate_icmp_af(struct pf_pdesc *pd, int af, void *arg) { struct icmp *icmp4; struct icmp6_hdr *icmp6; u_int32_t mtu; int32_t ptr = -1; u_int8_t type; u_int8_t code; switch (af) { case AF_INET: icmp6 = arg; type = icmp6->icmp6_type; code = icmp6->icmp6_code; mtu = ntohl(icmp6->icmp6_mtu); switch (type) { case ICMP6_ECHO_REQUEST: type = ICMP_ECHO; break; case ICMP6_ECHO_REPLY: type = ICMP_ECHOREPLY; break; case ICMP6_DST_UNREACH: type = ICMP_UNREACH; switch (code) { case ICMP6_DST_UNREACH_NOROUTE: case ICMP6_DST_UNREACH_BEYONDSCOPE: case ICMP6_DST_UNREACH_ADDR: code = ICMP_UNREACH_HOST; break; case ICMP6_DST_UNREACH_ADMIN: code = ICMP_UNREACH_HOST_PROHIB; break; case ICMP6_DST_UNREACH_NOPORT: code = ICMP_UNREACH_PORT; break; default: return (-1); } break; case ICMP6_PACKET_TOO_BIG: type = ICMP_UNREACH; code = ICMP_UNREACH_NEEDFRAG; mtu -= 20; break; case ICMP6_TIME_EXCEEDED: type = ICMP_TIMXCEED; break; case ICMP6_PARAM_PROB: switch (code) { case ICMP6_PARAMPROB_HEADER: type = ICMP_PARAMPROB; code = ICMP_PARAMPROB_ERRATPTR; ptr = ntohl(icmp6->icmp6_pptr); if (ptr == PTR_IP6(ip6_vfc)) ; /* preserve */ else if (ptr == PTR_IP6(ip6_vfc) + 1) ptr = PTR_IP(ip_tos); else if (ptr == PTR_IP6(ip6_plen) || ptr == PTR_IP6(ip6_plen) + 1) ptr = PTR_IP(ip_len); else if (ptr == PTR_IP6(ip6_nxt)) ptr = PTR_IP(ip_p); else if (ptr == PTR_IP6(ip6_hlim)) ptr = PTR_IP(ip_ttl); else if (ptr >= PTR_IP6(ip6_src) && ptr < PTR_IP6(ip6_dst)) ptr = PTR_IP(ip_src); else if (ptr >= PTR_IP6(ip6_dst) && ptr < sizeof(struct ip6_hdr)) ptr = PTR_IP(ip_dst); else { return (-1); } break; case ICMP6_PARAMPROB_NEXTHEADER: type = ICMP_UNREACH; code = ICMP_UNREACH_PROTOCOL; break; default: return (-1); } break; default: return (-1); } pf_patch_8(pd, &icmp6->icmp6_type, type, PF_HI); pf_patch_8(pd, &icmp6->icmp6_code, code, PF_LO); /* aligns well with a icmpv4 nextmtu */ pf_patch_32(pd, &icmp6->icmp6_mtu, htonl(mtu)); /* icmpv4 pptr is a one most significant byte */ if (ptr >= 0) pf_patch_32(pd, &icmp6->icmp6_pptr, htonl(ptr << 24)); break; case AF_INET6: icmp4 = arg; type = icmp4->icmp_type; code = icmp4->icmp_code; mtu = ntohs(icmp4->icmp_nextmtu); switch (type) { case ICMP_ECHO: type = ICMP6_ECHO_REQUEST; break; case ICMP_ECHOREPLY: type = ICMP6_ECHO_REPLY; break; case ICMP_UNREACH: type = ICMP6_DST_UNREACH; switch (code) { case ICMP_UNREACH_NET: case ICMP_UNREACH_HOST: case ICMP_UNREACH_NET_UNKNOWN: case ICMP_UNREACH_HOST_UNKNOWN: case ICMP_UNREACH_ISOLATED: case ICMP_UNREACH_TOSNET: case ICMP_UNREACH_TOSHOST: code = ICMP6_DST_UNREACH_NOROUTE; break; case ICMP_UNREACH_PORT: code = ICMP6_DST_UNREACH_NOPORT; break; case ICMP_UNREACH_NET_PROHIB: case ICMP_UNREACH_HOST_PROHIB: case ICMP_UNREACH_FILTER_PROHIB: case ICMP_UNREACH_PRECEDENCE_CUTOFF: code = ICMP6_DST_UNREACH_ADMIN; break; case ICMP_UNREACH_PROTOCOL: type = ICMP6_PARAM_PROB; code = ICMP6_PARAMPROB_NEXTHEADER; ptr = offsetof(struct ip6_hdr, ip6_nxt); break; case ICMP_UNREACH_NEEDFRAG: type = ICMP6_PACKET_TOO_BIG; code = 0; mtu += 20; break; default: return (-1); } break; case ICMP_TIMXCEED: type = ICMP6_TIME_EXCEEDED; break; case ICMP_PARAMPROB: type = ICMP6_PARAM_PROB; switch (code) { case ICMP_PARAMPROB_ERRATPTR: code = ICMP6_PARAMPROB_HEADER; break; case ICMP_PARAMPROB_LENGTH: code = ICMP6_PARAMPROB_HEADER; break; default: return (-1); } ptr = icmp4->icmp_pptr; if (ptr == 0 || ptr == PTR_IP(ip_tos)) ; /* preserve */ else if (ptr == PTR_IP(ip_len) || ptr == PTR_IP(ip_len) + 1) ptr = PTR_IP6(ip6_plen); else if (ptr == PTR_IP(ip_ttl)) ptr = PTR_IP6(ip6_hlim); else if (ptr == PTR_IP(ip_p)) ptr = PTR_IP6(ip6_nxt); else if (ptr >= PTR_IP(ip_src) && ptr < PTR_IP(ip_dst)) ptr = PTR_IP6(ip6_src); else if (ptr >= PTR_IP(ip_dst) && ptr < sizeof(struct ip)) ptr = PTR_IP6(ip6_dst); else { return (-1); } break; default: return (-1); } pf_patch_8(pd, &icmp4->icmp_type, type, PF_HI); pf_patch_8(pd, &icmp4->icmp_code, code, PF_LO); pf_patch_16(pd, &icmp4->icmp_nextmtu, htons(mtu)); if (ptr >= 0) pf_patch_32(pd, &icmp4->icmp_void, htonl(ptr)); break; } return (0); } #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 pf_pdesc *pd, struct pf_state_peer *dst) { struct sackblk sack; int copyback = 0, i; int olen, optsoff; u_int8_t opts[MAX_TCPOPTLEN], *opt, *eoh; olen = (pd->hdr.tcp.th_off << 2) - sizeof(struct tcphdr); optsoff = pd->off + sizeof(struct tcphdr); #define TCPOLEN_MINSACK (TCPOLEN_SACK + 2) if (olen < TCPOLEN_MINSACK || !pf_pull_hdr(pd->m, optsoff, opts, olen, NULL, pd->af)) return (0); eoh = opts + olen; opt = opts; while ((opt = pf_find_tcpopt(opt, opts, olen, TCPOPT_SACK, TCPOLEN_MINSACK)) != NULL) { size_t safelen = MIN(opt[1], (eoh - opt)); for (i = 2; i + TCPOLEN_SACK <= safelen; i += TCPOLEN_SACK) { size_t startoff = (opt + i) - opts; memcpy(&sack, &opt[i], sizeof(sack)); pf_patch_32_unaligned(pd, &sack.start, htonl(ntohl(sack.start) - dst->seqdiff), PF_ALGNMNT(startoff)); pf_patch_32_unaligned(pd, &sack.end, htonl(ntohl(sack.end) - dst->seqdiff), PF_ALGNMNT(startoff + sizeof(sack.start))); memcpy(&opt[i], &sack, sizeof(sack)); } copyback = 1; opt += opt[1]; } if (copyback) m_copyback(pd->m, optsoff, olen, opts, M_NOWAIT); return (copyback); } struct mbuf * pf_build_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, u_int sack, u_int rdom) { struct mbuf *m; int len, tlen; struct ip *h; #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; if (sack) tlen += 2; switch (af) { case AF_INET: len = sizeof(struct ip) + tlen; break; #ifdef INET6 case AF_INET6: len = sizeof(struct ip6_hdr) + tlen; break; #endif /* INET6 */ default: unhandled_af(af); } /* create outgoing mbuf */ m = m_gethdr(M_DONTWAIT, MT_HEADER); if (m == NULL) return (NULL); if (tag) m->m_pkthdr.pf.flags |= PF_TAG_GENERATED; m->m_pkthdr.pf.tag = rtag; m->m_pkthdr.ph_rtableid = rdom; if (r && (r->scrub_flags & PFSTATE_SETPRIO)) m->m_pkthdr.pf.prio = r->set_prio[0]; if (r && r->qid) m->m_pkthdr.pf.qid = r->qid; m->m_data += max_linkhdr; m->m_pkthdr.len = m->m_len = len; m->m_pkthdr.ph_ifidx = 0; m->m_pkthdr.csum_flags |= M_TCP_CSUM_OUT; memset(m->m_data, 0, len); switch (af) { case AF_INET: h = mtod(m, struct ip *); h->ip_p = IPPROTO_TCP; h->ip_len = htons(tlen); 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; 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; #ifdef INET6 case AF_INET6: h6 = mtod(m, struct ip6_hdr *); h6->ip6_nxt = IPPROTO_TCP; h6->ip6_plen = htons(tlen); h6->ip6_vfc |= IPV6_VERSION; h6->ip6_hlim = IPV6_DEFHLIM; 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 */ default: unhandled_af(af); } /* 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); opt = (char *)(th + 1); if (mss) { opt[0] = TCPOPT_MAXSEG; opt[1] = 4; mss = htons(mss); memcpy((opt + 2), &mss, 2); opt += 4; } if (sack) { opt[0] = TCPOPT_SACK_PERMITTED; opt[1] = 2; opt += 2; } return (m); } 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, u_int rdom) { struct mbuf *m; if ((m = pf_build_tcp(r, af, saddr, daddr, sport, dport, seq, ack, flags, win, mss, ttl, tag, rtag, 0, rdom)) == NULL) return; switch (af) { case AF_INET: ip_send(m); break; #ifdef INET6 case AF_INET6: ip6_send(m); break; #endif /* INET6 */ } } static void pf_send_challenge_ack(struct pf_pdesc *pd, struct pf_state *st, struct pf_state_peer *src, struct pf_state_peer *dst) { /* * We are sending challenge ACK as a response to SYN packet, which * matches existing state (modulo TCP window check). Therefore packet * must be sent on behalf of destination. * * We expect sender to remain either silent, or send RST packet * so both, firewall and remote peer, can purge dead state from * memory. */ pf_send_tcp(st->rule.ptr, pd->af, pd->dst, pd->src, pd->hdr.tcp.th_dport, pd->hdr.tcp.th_sport, dst->seqlo, src->seqlo, TH_ACK, 0, 0, st->rule.ptr->return_ttl, 1, 0, pd->rdomain); } void pf_send_icmp(struct mbuf *m, u_int8_t type, u_int8_t code, int param, sa_family_t af, struct pf_rule *r, u_int rdomain) { struct mbuf *m0; if ((m0 = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) return; m0->m_pkthdr.pf.flags |= PF_TAG_GENERATED; m0->m_pkthdr.ph_rtableid = rdomain; if (r && (r->scrub_flags & PFSTATE_SETPRIO)) m0->m_pkthdr.pf.prio = r->set_prio[0]; if (r && r->qid) m0->m_pkthdr.pf.qid = r->qid; switch (af) { case AF_INET: icmp_error(m0, type, code, 0, param); break; #ifdef INET6 case AF_INET6: icmp6_error(m0, type, code, param); break; #endif /* INET6 */ } } /* * Return ((n = 0) == (a = b [with mask m])) * Note: n != 0 => returns (a != b [with mask m]) */ int pf_match_addr(u_int8_t n, struct pf_addr *a, struct pf_addr *m, struct pf_addr *b, sa_family_t af) { switch (af) { case AF_INET: if ((a->addr32[0] & m->addr32[0]) == (b->addr32[0] & m->addr32[0])) return (n == 0); break; #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]))) return (n == 0); break; #endif /* INET6 */ } return (n != 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) { case AF_INET: if ((ntohl(a->addr32[0]) < ntohl(b->addr32[0])) || (ntohl(a->addr32[0]) > ntohl(e->addr32[0]))) return (0); break; #ifdef INET6 case AF_INET6: { int i; /* check a >= b */ for (i = 0; i < 4; ++i) if (ntohl(a->addr32[i]) > ntohl(b->addr32[i])) break; else if (ntohl(a->addr32[i]) < ntohl(b->addr32[i])) return (0); /* check a <= e */ for (i = 0; i < 4; ++i) if (ntohl(a->addr32[i]) < ntohl(e->addr32[i])) break; else if (ntohl(a->addr32[i]) > ntohl(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) { return (pf_match(op, ntohs(a1), ntohs(a2), ntohs(p))); } int pf_match_uid(u_int8_t op, uid_t a1, uid_t a2, uid_t u) { if (u == -1 && 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 == -1 && 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_match_rcvif(struct mbuf *m, struct pf_rule *r) { struct ifnet *ifp; #if NCARP > 0 struct ifnet *ifp0; #endif struct pfi_kif *kif; ifp = if_get(m->m_pkthdr.ph_ifidx); if (ifp == NULL) return (0); #if NCARP > 0 if (ifp->if_type == IFT_CARP && (ifp0 = if_get(ifp->if_carpdevidx)) != NULL) { kif = (struct pfi_kif *)ifp0->if_pf_kif; if_put(ifp0); } else #endif /* NCARP */ kif = (struct pfi_kif *)ifp->if_pf_kif; if_put(ifp); if (kif == NULL) { DPFPRINTF(LOG_ERR, "%s: kif == NULL, @%d via %s", __func__, r->nr, r->rcv_ifname); return (0); } return (pfi_kif_match(r->rcv_kif, kif)); } void pf_tag_packet(struct mbuf *m, int tag, int rtableid) { if (tag > 0) m->m_pkthdr.pf.tag = tag; if (rtableid >= 0) m->m_pkthdr.ph_rtableid = (u_int)rtableid; } void pf_anchor_stack_init(void) { struct pf_anchor_stackframe *stack; stack = (struct pf_anchor_stackframe *)cpumem_enter(pf_anchor_stack); stack[PF_ANCHOR_STACK_MAX].sf_stack_top = &stack[0]; cpumem_leave(pf_anchor_stack, stack); } int pf_anchor_stack_is_full(struct pf_anchor_stackframe *sf) { struct pf_anchor_stackframe *stack; int rv; stack = (struct pf_anchor_stackframe *)cpumem_enter(pf_anchor_stack); rv = (sf == &stack[PF_ANCHOR_STACK_MAX]); cpumem_leave(pf_anchor_stack, stack); return (rv); } int pf_anchor_stack_is_empty(struct pf_anchor_stackframe *sf) { struct pf_anchor_stackframe *stack; int rv; stack = (struct pf_anchor_stackframe *)cpumem_enter(pf_anchor_stack); rv = (sf == &stack[0]); cpumem_leave(pf_anchor_stack, stack); return (rv); } struct pf_anchor_stackframe * pf_anchor_stack_top(void) { struct pf_anchor_stackframe *stack; struct pf_anchor_stackframe *top_sf; stack = (struct pf_anchor_stackframe *)cpumem_enter(pf_anchor_stack); top_sf = stack[PF_ANCHOR_STACK_MAX].sf_stack_top; cpumem_leave(pf_anchor_stack, stack); return (top_sf); } int pf_anchor_stack_push(struct pf_ruleset *rs, struct pf_rule *anchor, struct pf_rule *r, struct pf_anchor *child, int jump_target) { struct pf_anchor_stackframe *stack; struct pf_anchor_stackframe *top_sf = pf_anchor_stack_top(); top_sf++; if (pf_anchor_stack_is_full(top_sf)) return (-1); top_sf->sf_rs = rs; top_sf->sf_anchor = anchor; top_sf->sf_r = r; top_sf->sf_child = child; top_sf->sf_jump_target = jump_target; stack = (struct pf_anchor_stackframe *)cpumem_enter(pf_anchor_stack); if ((top_sf <= &stack[0]) || (top_sf >= &stack[PF_ANCHOR_STACK_MAX])) panic("%s: top frame outside of anchor stack range", __func__); stack[PF_ANCHOR_STACK_MAX].sf_stack_top = top_sf; cpumem_leave(pf_anchor_stack, stack); return (0); } int pf_anchor_stack_pop(struct pf_ruleset **rs, struct pf_rule **anchor, struct pf_rule **r, struct pf_anchor **child, int *jump_target) { struct pf_anchor_stackframe *top_sf = pf_anchor_stack_top(); struct pf_anchor_stackframe *stack; int on_top; stack = (struct pf_anchor_stackframe *)cpumem_enter(pf_anchor_stack); if (pf_anchor_stack_is_empty(top_sf)) { on_top = -1; } else { if ((top_sf <= &stack[0]) || (top_sf >= &stack[PF_ANCHOR_STACK_MAX])) panic("%s: top frame outside of anchor stack range", __func__); *rs = top_sf->sf_rs; *anchor = top_sf->sf_anchor; *r = top_sf->sf_r; *child = top_sf->sf_child; *jump_target = top_sf->sf_jump_target; top_sf--; stack[PF_ANCHOR_STACK_MAX].sf_stack_top = top_sf; on_top = 0; } cpumem_leave(pf_anchor_stack, stack); return (on_top); } 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) { case AF_INET: naddr->addr32[0] = (raddr->addr32[0] & rmask->addr32[0]) | ((rmask->addr32[0] ^ 0xffffffff ) & saddr->addr32[0]); break; #ifdef INET6 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; #endif /* INET6 */ default: unhandled_af(af); } } void pf_addr_inc(struct pf_addr *addr, sa_family_t af) { switch (af) { case AF_INET: addr->addr32[0] = htonl(ntohl(addr->addr32[0]) + 1); break; #ifdef INET6 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 */ default: unhandled_af(af); } } int pf_socket_lookup(struct pf_pdesc *pd) { struct pf_addr *saddr, *daddr; u_int16_t sport, dport; struct inpcbtable *table; struct inpcb *inp; pd->lookup.uid = -1; pd->lookup.gid = -1; pd->lookup.pid = NO_PID; switch (pd->virtual_proto) { case IPPROTO_TCP: sport = pd->hdr.tcp.th_sport; dport = pd->hdr.tcp.th_dport; PF_ASSERT_LOCKED(); NET_ASSERT_LOCKED(); table = &tcbtable; break; case IPPROTO_UDP: sport = pd->hdr.udp.uh_sport; dport = pd->hdr.udp.uh_dport; PF_ASSERT_LOCKED(); NET_ASSERT_LOCKED(); table = &udbtable; break; default: return (-1); } if (pd->dir == 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) { case AF_INET: /* * Fails when rtable is changed while evaluating the ruleset * The socket looked up will not match the one hit in the end. */ inp = in_pcblookup(table, saddr->v4, sport, daddr->v4, dport, pd->rdomain); if (inp == NULL) { inp = in_pcblookup_listen(table, daddr->v4, dport, NULL, pd->rdomain); if (inp == NULL) return (-1); } break; #ifdef INET6 case AF_INET6: if (pd->virtual_proto == IPPROTO_UDP) table = &udb6table; if (pd->virtual_proto == IPPROTO_TCP) table = &tcb6table; inp = in6_pcblookup(table, &saddr->v6, sport, &daddr->v6, dport, pd->rdomain); if (inp == NULL) { inp = in6_pcblookup_listen(table, &daddr->v6, dport, NULL, pd->rdomain); if (inp == NULL) return (-1); } break; #endif /* INET6 */ default: unhandled_af(pd->af); } pd->lookup.uid = inp->inp_socket->so_euid; pd->lookup.gid = inp->inp_socket->so_egid; pd->lookup.pid = inp->inp_socket->so_cpid; in_pcbunref(inp); return (1); } /* post: r => (r[0] == type /\ r[1] >= min_typelen >= 2 "validity" * /\ (eoh - r) >= min_typelen >= 2 "safety" ) * * warning: r + r[1] may exceed opts bounds for r[1] > min_typelen */ u_int8_t* pf_find_tcpopt(u_int8_t *opt, u_int8_t *opts, size_t hlen, u_int8_t type, u_int8_t min_typelen) { u_int8_t *eoh = opts + hlen; if (min_typelen < 2) return (NULL); while ((eoh - opt) >= min_typelen) { switch (*opt) { case TCPOPT_EOL: /* FALLTHROUGH - Workaround the failure of some systems to NOP-pad their bzero'd option buffers, producing spurious EOLs */ case TCPOPT_NOP: opt++; continue; default: if (opt[0] == type && opt[1] >= min_typelen) return (opt); } opt += MAX(opt[1], 2); /* evade infinite loops */ } return (NULL); } u_int8_t pf_get_wscale(struct pf_pdesc *pd) { int olen; u_int8_t opts[MAX_TCPOPTLEN], *opt; u_int8_t wscale = 0; olen = (pd->hdr.tcp.th_off << 2) - sizeof(struct tcphdr); if (olen < TCPOLEN_WINDOW || !pf_pull_hdr(pd->m, pd->off + sizeof(struct tcphdr), opts, olen, NULL, pd->af)) return (0); opt = opts; while ((opt = pf_find_tcpopt(opt, opts, olen, TCPOPT_WINDOW, TCPOLEN_WINDOW)) != NULL) { wscale = opt[2]; wscale = MIN(wscale, TCP_MAX_WINSHIFT); wscale |= PF_WSCALE_FLAG; opt += opt[1]; } return (wscale); } u_int16_t pf_get_mss(struct pf_pdesc *pd) { int olen; u_int8_t opts[MAX_TCPOPTLEN], *opt; u_int16_t mss = tcp_mssdflt; olen = (pd->hdr.tcp.th_off << 2) - sizeof(struct tcphdr); if (olen < TCPOLEN_MAXSEG || !pf_pull_hdr(pd->m, pd->off + sizeof(struct tcphdr), opts, olen, NULL, pd->af)) return (0); opt = opts; while ((opt = pf_find_tcpopt(opt, opts, olen, TCPOPT_MAXSEG, TCPOLEN_MAXSEG)) != NULL) { memcpy(&mss, (opt + 2), 2); mss = ntohs(mss); opt += opt[1]; } return (mss); } u_int16_t pf_calc_mss(struct pf_addr *addr, sa_family_t af, int rtableid, u_int16_t offer) { struct ifnet *ifp; struct sockaddr_in *dst; #ifdef INET6 struct sockaddr_in6 *dst6; #endif /* INET6 */ struct rtentry *rt = NULL; struct sockaddr_storage ss; int hlen; u_int16_t mss = tcp_mssdflt; memset(&ss, 0, sizeof(ss)); switch (af) { case AF_INET: hlen = sizeof(struct ip); dst = (struct sockaddr_in *)&ss; dst->sin_family = AF_INET; dst->sin_len = sizeof(*dst); dst->sin_addr = addr->v4; rt = rtalloc(sintosa(dst), 0, rtableid); break; #ifdef INET6 case AF_INET6: hlen = sizeof(struct ip6_hdr); dst6 = (struct sockaddr_in6 *)&ss; dst6->sin6_family = AF_INET6; dst6->sin6_len = sizeof(*dst6); dst6->sin6_addr = addr->v6; rt = rtalloc(sin6tosa(dst6), 0, rtableid); break; #endif /* INET6 */ } if (rt != NULL && (ifp = if_get(rt->rt_ifidx)) != NULL) { mss = ifp->if_mtu - hlen - sizeof(struct tcphdr); mss = max(tcp_mssdflt, mss); if_put(ifp); } rtfree(rt); mss = min(mss, offer); mss = max(mss, 64); /* sanity - at least max opt space */ return (mss); } static __inline int pf_set_rt_ifp(struct pf_state *st, struct pf_addr *saddr, sa_family_t af, struct pf_src_node **sns) { struct pf_rule *r = st->rule.ptr; int rv; if (!r->rt) return (0); rv = pf_map_addr(af, r, saddr, &st->rt_addr, NULL, sns, &r->route, PF_SN_ROUTE); if (rv == 0) st->rt = r->rt; return (rv); } u_int32_t pf_tcp_iss(struct pf_pdesc *pd) { SHA2_CTX ctx; union { uint8_t bytes[SHA512_DIGEST_LENGTH]; uint32_t words[1]; } digest; if (pf_tcp_secret_init == 0) { arc4random_buf(pf_tcp_secret, sizeof(pf_tcp_secret)); SHA512Init(&pf_tcp_secret_ctx); SHA512Update(&pf_tcp_secret_ctx, pf_tcp_secret, sizeof(pf_tcp_secret)); pf_tcp_secret_init = 1; } ctx = pf_tcp_secret_ctx; SHA512Update(&ctx, &pd->rdomain, sizeof(pd->rdomain)); SHA512Update(&ctx, &pd->hdr.tcp.th_sport, sizeof(u_short)); SHA512Update(&ctx, &pd->hdr.tcp.th_dport, sizeof(u_short)); switch (pd->af) { case AF_INET: SHA512Update(&ctx, &pd->src->v4, sizeof(struct in_addr)); SHA512Update(&ctx, &pd->dst->v4, sizeof(struct in_addr)); break; #ifdef INET6 case AF_INET6: SHA512Update(&ctx, &pd->src->v6, sizeof(struct in6_addr)); SHA512Update(&ctx, &pd->dst->v6, sizeof(struct in6_addr)); break; #endif /* INET6 */ } SHA512Final(digest.bytes, &ctx); pf_tcp_iss_off += 4096; return (digest.words[0] + READ_ONCE(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; #if NPFLOG > 0 a->log |= r->log; #endif /* NPFLOG > 0 */ 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|PFSTATE_SETPRIO)); if (r->scrub_flags & PFSTATE_SETPRIO) { a->set_prio[0] = r->set_prio[0]; a->set_prio[1] = r->set_prio[1]; } if (r->rule_flag & PFRULE_SETDELAY) a->delay = r->delay; } #define PF_TEST_ATTRIB(t, a) \ if (t) { \ r = a; \ continue; \ } else do { \ } while (0) enum pf_test_status pf_match_rule(struct pf_test_ctx *ctx, struct pf_ruleset *ruleset) { struct pf_rule *r; struct pf_anchor *child = NULL; int target; pf_anchor_stack_init(); enter_ruleset: r = TAILQ_FIRST(ruleset->rules.active.ptr); while (r != NULL) { PF_TEST_ATTRIB(r->rule_flag & PFRULE_EXPIRED, TAILQ_NEXT(r, entries)); r->evaluations++; PF_TEST_ATTRIB( (pfi_kif_match(r->kif, ctx->pd->kif) == r->ifnot), r->skip[PF_SKIP_IFP].ptr); PF_TEST_ATTRIB((r->direction && r->direction != ctx->pd->dir), r->skip[PF_SKIP_DIR].ptr); PF_TEST_ATTRIB((r->onrdomain >= 0 && (r->onrdomain == ctx->pd->rdomain) == r->ifnot), r->skip[PF_SKIP_RDOM].ptr); PF_TEST_ATTRIB((r->af && r->af != ctx->pd->af), r->skip[PF_SKIP_AF].ptr); PF_TEST_ATTRIB((r->proto && r->proto != ctx->pd->proto), r->skip[PF_SKIP_PROTO].ptr); PF_TEST_ATTRIB((PF_MISMATCHAW(&r->src.addr, &ctx->pd->nsaddr, ctx->pd->naf, r->src.neg, ctx->pd->kif, ctx->act.rtableid)), r->skip[PF_SKIP_SRC_ADDR].ptr); PF_TEST_ATTRIB((PF_MISMATCHAW(&r->dst.addr, &ctx->pd->ndaddr, ctx->pd->af, r->dst.neg, NULL, ctx->act.rtableid)), r->skip[PF_SKIP_DST_ADDR].ptr); switch (ctx->pd->virtual_proto) { case PF_VPROTO_FRAGMENT: /* tcp/udp only. port_op always 0 in other cases */ PF_TEST_ATTRIB((r->src.port_op || r->dst.port_op), TAILQ_NEXT(r, entries)); PF_TEST_ATTRIB((ctx->pd->proto == IPPROTO_TCP && r->flagset), TAILQ_NEXT(r, entries)); /* icmp only. type/code always 0 in other cases */ PF_TEST_ATTRIB((r->type || r->code), TAILQ_NEXT(r, entries)); /* tcp/udp only. {uid|gid}.op always 0 in other cases */ PF_TEST_ATTRIB((r->gid.op || r->uid.op), TAILQ_NEXT(r, entries)); break; case IPPROTO_TCP: PF_TEST_ATTRIB(((r->flagset & ctx->th->th_flags) != r->flags), TAILQ_NEXT(r, entries)); PF_TEST_ATTRIB((r->os_fingerprint != PF_OSFP_ANY && !pf_osfp_match(pf_osfp_fingerprint(ctx->pd), r->os_fingerprint)), TAILQ_NEXT(r, entries)); /* FALLTHROUGH */ case IPPROTO_UDP: /* tcp/udp only. port_op always 0 in other cases */ PF_TEST_ATTRIB((r->src.port_op && !pf_match_port(r->src.port_op, r->src.port[0], r->src.port[1], ctx->pd->nsport)), r->skip[PF_SKIP_SRC_PORT].ptr); PF_TEST_ATTRIB((r->dst.port_op && !pf_match_port(r->dst.port_op, r->dst.port[0], r->dst.port[1], ctx->pd->ndport)), r->skip[PF_SKIP_DST_PORT].ptr); /* tcp/udp only. uid.op always 0 in other cases */ PF_TEST_ATTRIB((r->uid.op && (ctx->pd->lookup.done || (ctx->pd->lookup.done = pf_socket_lookup(ctx->pd), 1)) && !pf_match_uid(r->uid.op, r->uid.uid[0], r->uid.uid[1], ctx->pd->lookup.uid)), TAILQ_NEXT(r, entries)); /* tcp/udp only. gid.op always 0 in other cases */ PF_TEST_ATTRIB((r->gid.op && (ctx->pd->lookup.done || (ctx->pd->lookup.done = pf_socket_lookup(ctx->pd), 1)) && !pf_match_gid(r->gid.op, r->gid.gid[0], r->gid.gid[1], ctx->pd->lookup.gid)), TAILQ_NEXT(r, entries)); break; case IPPROTO_ICMP: /* icmp only. type always 0 in other cases */ PF_TEST_ATTRIB((r->type && r->type != ctx->icmptype + 1), TAILQ_NEXT(r, entries)); /* icmp only. type always 0 in other cases */ PF_TEST_ATTRIB((r->code && r->code != ctx->icmpcode + 1), TAILQ_NEXT(r, entries)); /* icmp only. don't create states on replies */ PF_TEST_ATTRIB((r->keep_state && !ctx->state_icmp && (r->rule_flag & PFRULE_STATESLOPPY) == 0 && ctx->icmp_dir != PF_IN), TAILQ_NEXT(r, entries)); break; case IPPROTO_ICMPV6: /* icmp only. type always 0 in other cases */ PF_TEST_ATTRIB((r->type && r->type != ctx->icmptype + 1), TAILQ_NEXT(r, entries)); /* icmp only. type always 0 in other cases */ PF_TEST_ATTRIB((r->code && r->code != ctx->icmpcode + 1), TAILQ_NEXT(r, entries)); /* icmp only. don't create states on replies */ PF_TEST_ATTRIB((r->keep_state && !ctx->state_icmp && (r->rule_flag & PFRULE_STATESLOPPY) == 0 && ctx->icmp_dir != PF_IN && ctx->icmptype != ND_NEIGHBOR_ADVERT), TAILQ_NEXT(r, entries)); break; default: break; } PF_TEST_ATTRIB((r->rule_flag & PFRULE_FRAGMENT && ctx->pd->virtual_proto != PF_VPROTO_FRAGMENT), TAILQ_NEXT(r, entries)); PF_TEST_ATTRIB((r->tos && !(r->tos == ctx->pd->tos)), TAILQ_NEXT(r, entries)); PF_TEST_ATTRIB((r->prob && r->prob <= arc4random_uniform(UINT_MAX - 1) + 1), TAILQ_NEXT(r, entries)); PF_TEST_ATTRIB((r->match_tag && !pf_match_tag(ctx->pd->m, r, &ctx->tag)), TAILQ_NEXT(r, entries)); PF_TEST_ATTRIB((r->rcv_kif && pf_match_rcvif(ctx->pd->m, r) == r->rcvifnot), TAILQ_NEXT(r, entries)); PF_TEST_ATTRIB((r->prio && (r->prio == PF_PRIO_ZERO ? 0 : r->prio) != ctx->pd->m->m_pkthdr.pf.prio), TAILQ_NEXT(r, entries)); /* must be last! */ if (r->pktrate.limit) { pf_add_threshold(&r->pktrate); PF_TEST_ATTRIB((pf_check_threshold(&r->pktrate)), TAILQ_NEXT(r, entries)); } /* FALLTHROUGH */ if (r->tag) ctx->tag = r->tag; if (r->anchor == NULL) { if (r->rule_flag & PFRULE_ONCE) { u_int32_t rule_flag; rule_flag = r->rule_flag; if (((rule_flag & PFRULE_EXPIRED) == 0) && atomic_cas_uint(&r->rule_flag, rule_flag, rule_flag | PFRULE_EXPIRED) == rule_flag) { r->exptime = gettime(); } else { r = TAILQ_NEXT(r, entries); continue; } } if (r->action == PF_MATCH) { if ((ctx->ri = pool_get(&pf_rule_item_pl, PR_NOWAIT)) == NULL) { REASON_SET(&ctx->reason, PFRES_MEMORY); return (PF_TEST_FAIL); } ctx->ri->r = r; /* order is irrelevant */ SLIST_INSERT_HEAD(&ctx->rules, ctx->ri, entry); ctx->ri = NULL; pf_rule_to_actions(r, &ctx->act); if (r->rule_flag & PFRULE_AFTO) ctx->pd->naf = r->naf; if (pf_get_transaddr(r, ctx->pd, ctx->sns, &ctx->nr) == -1) { REASON_SET(&ctx->reason, PFRES_TRANSLATE); return (PF_TEST_FAIL); } #if NPFLOG > 0 if (r->log) { REASON_SET(&ctx->reason, PFRES_MATCH); pflog_packet(ctx->pd, ctx->reason, r, ctx->a, ruleset, NULL); } #endif /* NPFLOG > 0 */ } else { /* * found matching r */ *ctx->rm = r; /* * anchor, with ruleset, where r belongs to */ *ctx->am = ctx->a; /* * ruleset where r belongs to */ *ctx->rsm = ruleset; /* * ruleset, where anchor belongs to. */ ctx->arsm = ctx->aruleset; } #if NPFLOG > 0 if (ctx->act.log & PF_LOG_MATCHES) pf_log_matches(ctx->pd, r, ctx->a, ruleset, &ctx->rules); #endif /* NPFLOG > 0 */ if (r->quick) return (PF_TEST_QUICK); } else { ctx->aruleset = &r->anchor->ruleset; if (r->anchor_wildcard) { RB_FOREACH(child, pf_anchor_node, &r->anchor->children) { if (pf_anchor_stack_push(ruleset, ctx->a, r, child, PF_NEXT_CHILD) != 0) return (PF_TEST_FAIL); ctx->a = r; ruleset = &child->ruleset; goto enter_ruleset; next_child: continue; /* with RB_FOREACH() */ } } else { if (pf_anchor_stack_push(ruleset, ctx->a, r, child, PF_NEXT_RULE) != 0) return (PF_TEST_FAIL); ctx->a = r; ruleset = &r->anchor->ruleset; child = NULL; goto enter_ruleset; next_rule: ; } } r = TAILQ_NEXT(r, entries); } if (pf_anchor_stack_pop(&ruleset, &ctx->a, &r, &child, &target) == 0) { /* stop if any rule matched within quick anchors. */ if (r->quick == PF_TEST_QUICK && *ctx->am == r) return (PF_TEST_QUICK); switch (target) { case PF_NEXT_CHILD: goto next_child; case PF_NEXT_RULE: goto next_rule; default: panic("%s: unknown jump target", __func__); } } return (PF_TEST_OK); } int pf_test_rule(struct pf_pdesc *pd, struct pf_rule **rm, struct pf_state **sm, struct pf_rule **am, struct pf_ruleset **rsm, u_short *reason) { struct pf_rule *r = NULL; struct pf_rule *a = NULL; struct pf_ruleset *ruleset = NULL; struct pf_state_key *skw = NULL, *sks = NULL; int rewrite = 0; u_int16_t virtual_type, virtual_id; int action = PF_DROP; struct pf_test_ctx ctx; int rv; PF_ASSERT_LOCKED(); memset(&ctx, 0, sizeof(ctx)); ctx.pd = pd; ctx.rm = rm; ctx.am = am; ctx.rsm = rsm; ctx.th = &pd->hdr.tcp; ctx.act.rtableid = pd->rdomain; ctx.tag = -1; SLIST_INIT(&ctx.rules); if (pd->dir == PF_IN && if_congested()) { REASON_SET(&ctx.reason, PFRES_CONGEST); return (PF_DROP); } switch (pd->virtual_proto) { case IPPROTO_ICMP: ctx.icmptype = pd->hdr.icmp.icmp_type; ctx.icmpcode = pd->hdr.icmp.icmp_code; ctx.state_icmp = pf_icmp_mapping(pd, ctx.icmptype, &ctx.icmp_dir, &virtual_id, &virtual_type); if (ctx.icmp_dir == PF_IN) { pd->osport = pd->nsport = virtual_id; pd->odport = pd->ndport = virtual_type; } else { pd->osport = pd->nsport = virtual_type; pd->odport = pd->ndport = virtual_id; } break; #ifdef INET6 case IPPROTO_ICMPV6: ctx.icmptype = pd->hdr.icmp6.icmp6_type; ctx.icmpcode = pd->hdr.icmp6.icmp6_code; ctx.state_icmp = pf_icmp_mapping(pd, ctx.icmptype, &ctx.icmp_dir, &virtual_id, &virtual_type); if (ctx.icmp_dir == PF_IN) { pd->osport = pd->nsport = virtual_id; pd->odport = pd->ndport = virtual_type; } else { pd->osport = pd->nsport = virtual_type; pd->odport = pd->ndport = virtual_id; } break; #endif /* INET6 */ } ruleset = &pf_main_ruleset; rv = pf_match_rule(&ctx, ruleset); if (rv == PF_TEST_FAIL) { /* * Reason has been set in pf_match_rule() already. */ goto cleanup; } r = *ctx.rm; /* matching rule */ a = *ctx.am; /* rule that defines an anchor containing 'r' */ ruleset = *ctx.rsm;/* ruleset of the anchor defined by the rule 'a' */ ctx.aruleset = ctx.arsm;/* ruleset of the 'a' rule itself */ /* apply actions for last matching pass/block rule */ pf_rule_to_actions(r, &ctx.act); if (r->rule_flag & PFRULE_AFTO) pd->naf = r->naf; if (pf_get_transaddr(r, pd, ctx.sns, &ctx.nr) == -1) { REASON_SET(&ctx.reason, PFRES_TRANSLATE); goto cleanup; } REASON_SET(&ctx.reason, PFRES_MATCH); #if NPFLOG > 0 if (r->log) pflog_packet(pd, ctx.reason, r, a, ruleset, NULL); if (ctx.act.log & PF_LOG_MATCHES) pf_log_matches(pd, r, a, ruleset, &ctx.rules); #endif /* NPFLOG > 0 */ if (pd->virtual_proto != PF_VPROTO_FRAGMENT && (r->action == PF_DROP) && ((r->rule_flag & PFRULE_RETURNRST) || (r->rule_flag & PFRULE_RETURNICMP) || (r->rule_flag & PFRULE_RETURN))) { if (pd->proto == IPPROTO_TCP && ((r->rule_flag & PFRULE_RETURNRST) || (r->rule_flag & PFRULE_RETURN)) && !(ctx.th->th_flags & TH_RST)) { u_int32_t ack = ntohl(ctx.th->th_seq) + pd->p_len; if (pf_check_tcp_cksum(pd->m, pd->off, pd->tot_len - pd->off, pd->af)) REASON_SET(&ctx.reason, PFRES_PROTCKSUM); else { if (ctx.th->th_flags & TH_SYN) ack++; if (ctx.th->th_flags & TH_FIN) ack++; pf_send_tcp(r, pd->af, pd->dst, pd->src, ctx.th->th_dport, ctx.th->th_sport, ntohl(ctx.th->th_ack), ack, TH_RST|TH_ACK, 0, 0, r->return_ttl, 1, 0, pd->rdomain); } } else if ((pd->proto != IPPROTO_ICMP || ICMP_INFOTYPE(ctx.icmptype)) && pd->af == AF_INET && r->return_icmp) pf_send_icmp(pd->m, r->return_icmp >> 8, r->return_icmp & 255, 0, pd->af, r, pd->rdomain); else if ((pd->proto != IPPROTO_ICMPV6 || (ctx.icmptype >= ICMP6_ECHO_REQUEST && ctx.icmptype != ND_REDIRECT)) && pd->af == AF_INET6 && r->return_icmp6) pf_send_icmp(pd->m, r->return_icmp6 >> 8, r->return_icmp6 & 255, 0, pd->af, r, pd->rdomain); } if (r->action == PF_DROP) goto cleanup; pf_tag_packet(pd->m, ctx.tag, ctx.act.rtableid); if (ctx.act.rtableid >= 0 && rtable_l2(ctx.act.rtableid) != pd->rdomain) pd->destchg = 1; if (r->action == PF_PASS && pd->badopts != 0 && ! r->allow_opts) { REASON_SET(&ctx.reason, PFRES_IPOPTIONS); #if NPFLOG > 0 pd->pflog |= PF_LOG_FORCE; #endif /* NPFLOG > 0 */ DPFPRINTF(LOG_NOTICE, "dropping packet with " "ip/ipv6 options in pf_test_rule()"); goto cleanup; } if (pd->virtual_proto != PF_VPROTO_FRAGMENT && !ctx.state_icmp && r->keep_state) { if (r->rule_flag & PFRULE_SRCTRACK && pf_insert_src_node(&ctx.sns[PF_SN_NONE], r, PF_SN_NONE, pd->af, pd->src, NULL, NULL) != 0) { REASON_SET(&ctx.reason, PFRES_SRCLIMIT); goto cleanup; } if (r->max_states && (r->states_cur >= r->max_states)) { pf_status.lcounters[LCNT_STATES]++; REASON_SET(&ctx.reason, PFRES_MAXSTATES); goto cleanup; } action = pf_create_state(pd, r, a, ctx.nr, &skw, &sks, &rewrite, sm, ctx.tag, &ctx.rules, &ctx.act, ctx.sns); if (action != PF_PASS) goto cleanup; if (sks != skw) { struct pf_state_key *sk; if (pd->dir == PF_IN) sk = sks; else sk = skw; rewrite += pf_translate(pd, &sk->addr[pd->af == pd->naf ? pd->sidx : pd->didx], sk->port[pd->af == pd->naf ? pd->sidx : pd->didx], &sk->addr[pd->af == pd->naf ? pd->didx : pd->sidx], sk->port[pd->af == pd->naf ? pd->didx : pd->sidx], virtual_type, ctx.icmp_dir); } #ifdef INET6 if (rewrite && skw->af != sks->af) action = PF_AFRT; #endif /* INET6 */ } else { action = PF_PASS; while ((ctx.ri = SLIST_FIRST(&ctx.rules))) { SLIST_REMOVE_HEAD(&ctx.rules, entry); pool_put(&pf_rule_item_pl, ctx.ri); } } /* copy back packet headers if needed */ if (rewrite && pd->hdrlen) { m_copyback(pd->m, pd->off, pd->hdrlen, &pd->hdr, M_NOWAIT); } #if NPFSYNC > 0 if (*sm != NULL && !ISSET((*sm)->state_flags, PFSTATE_NOSYNC) && pd->dir == PF_OUT && pfsync_is_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, pd->m)) return (PF_DEFER); } #endif /* NPFSYNC > 0 */ return (action); cleanup: while ((ctx.ri = SLIST_FIRST(&ctx.rules))) { SLIST_REMOVE_HEAD(&ctx.rules, entry); pool_put(&pf_rule_item_pl, ctx.ri); } return (action); } static __inline int pf_create_state(struct pf_pdesc *pd, struct pf_rule *r, struct pf_rule *a, struct pf_rule *nr, struct pf_state_key **skw, struct pf_state_key **sks, int *rewrite, struct pf_state **sm, int tag, struct pf_rule_slist *rules, struct pf_rule_actions *act, struct pf_src_node *sns[PF_SN_MAX]) { struct pf_state *st = NULL; struct tcphdr *th = &pd->hdr.tcp; u_int16_t mss = tcp_mssdflt; u_short reason; u_int i; st = pool_get(&pf_state_pl, PR_NOWAIT | PR_ZERO); if (st == NULL) { REASON_SET(&reason, PFRES_MEMORY); goto csfailed; } st->rule.ptr = r; st->anchor.ptr = a; st->natrule.ptr = nr; if (r->allow_opts) st->state_flags |= PFSTATE_ALLOWOPTS; if (r->rule_flag & PFRULE_STATESLOPPY) st->state_flags |= PFSTATE_SLOPPY; if (r->rule_flag & PFRULE_PFLOW) st->state_flags |= PFSTATE_PFLOW; if (r->rule_flag & PFRULE_NOSYNC) st->state_flags |= PFSTATE_NOSYNC; #if NPFLOG > 0 st->log = act->log & PF_LOG_ALL; #endif /* NPFLOG > 0 */ st->qid = act->qid; st->pqid = act->pqid; st->rtableid[pd->didx] = act->rtableid; st->rtableid[pd->sidx] = -1; /* return traffic is routed normally */ st->min_ttl = act->min_ttl; st->set_tos = act->set_tos; st->max_mss = act->max_mss; st->state_flags |= act->flags; #if NPFSYNC > 0 st->sync_state = PFSYNC_S_NONE; #endif /* NPFSYNC > 0 */ st->set_prio[0] = act->set_prio[0]; st->set_prio[1] = act->set_prio[1]; st->delay = act->delay; SLIST_INIT(&st->src_nodes); /* * must initialize refcnt, before pf_state_insert() gets called. * pf_state_inserts() grabs reference for pfsync! */ PF_REF_INIT(st->refcnt); mtx_init(&st->mtx, IPL_NET); switch (pd->proto) { case IPPROTO_TCP: st->src.seqlo = ntohl(th->th_seq); st->src.seqhi = st->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 */ st->src.seqdiff = pf_tcp_iss(pd) - st->src.seqlo; if (st->src.seqdiff == 0) st->src.seqdiff = 1; pf_patch_32(pd, &th->th_seq, htonl(st->src.seqlo + st->src.seqdiff)); *rewrite = 1; } else st->src.seqdiff = 0; if (th->th_flags & TH_SYN) { st->src.seqhi++; st->src.wscale = pf_get_wscale(pd); } st->src.max_win = MAX(ntohs(th->th_win), 1); if (st->src.wscale & PF_WSCALE_MASK) { /* Remove scale factor from initial window */ int win = st->src.max_win; win += 1 << (st->src.wscale & PF_WSCALE_MASK); st->src.max_win = (win - 1) >> (st->src.wscale & PF_WSCALE_MASK); } if (th->th_flags & TH_FIN) st->src.seqhi++; st->dst.seqhi = 1; st->dst.max_win = 1; pf_set_protostate(st, PF_PEER_SRC, TCPS_SYN_SENT); pf_set_protostate(st, PF_PEER_DST, TCPS_CLOSED); st->timeout = PFTM_TCP_FIRST_PACKET; pf_status.states_halfopen++; break; case IPPROTO_UDP: pf_set_protostate(st, PF_PEER_SRC, PFUDPS_SINGLE); pf_set_protostate(st, PF_PEER_DST, PFUDPS_NO_TRAFFIC); st->timeout = PFTM_UDP_FIRST_PACKET; break; case IPPROTO_ICMP: #ifdef INET6 case IPPROTO_ICMPV6: #endif /* INET6 */ st->timeout = PFTM_ICMP_FIRST_PACKET; break; default: pf_set_protostate(st, PF_PEER_SRC, PFOTHERS_SINGLE); pf_set_protostate(st, PF_PEER_DST, PFOTHERS_NO_TRAFFIC); st->timeout = PFTM_OTHER_FIRST_PACKET; } st->creation = getuptime(); st->expire = getuptime(); if (pd->proto == IPPROTO_TCP) { if (st->state_flags & PFSTATE_SCRUB_TCP && pf_normalize_tcp_init(pd, &st->src)) { REASON_SET(&reason, PFRES_MEMORY); goto csfailed; } if (st->state_flags & PFSTATE_SCRUB_TCP && st->src.scrub && pf_normalize_tcp_stateful(pd, &reason, st, &st->src, &st->dst, rewrite)) { /* This really shouldn't happen!!! */ DPFPRINTF(LOG_ERR, "%s: tcp normalize failed on first pkt", __func__); goto csfailed; } } st->direction = pd->dir; if (pf_state_key_setup(pd, skw, sks, act->rtableid)) { REASON_SET(&reason, PFRES_MEMORY); goto csfailed; } if (pf_set_rt_ifp(st, pd->src, (*skw)->af, sns) != 0) { REASON_SET(&reason, PFRES_NOROUTE); goto csfailed; } for (i = 0; i < PF_SN_MAX; i++) if (sns[i] != NULL) { struct pf_sn_item *sni; sni = pool_get(&pf_sn_item_pl, PR_NOWAIT); if (sni == NULL) { REASON_SET(&reason, PFRES_MEMORY); goto csfailed; } sni->sn = sns[i]; SLIST_INSERT_HEAD(&st->src_nodes, sni, next); sni->sn->states++; } #if NPFSYNC > 0 pfsync_init_state(st, *skw, *sks, 0); #endif if (pf_state_insert(BOUND_IFACE(r, pd->kif), skw, sks, st)) { *sks = *skw = NULL; REASON_SET(&reason, PFRES_STATEINS); goto csfailed; } else *sm = st; /* * Make state responsible for rules it binds here. */ memcpy(&st->match_rules, rules, sizeof(st->match_rules)); memset(rules, 0, sizeof(*rules)); STATE_INC_COUNTERS(st); if (tag > 0) { pf_tag_ref(tag); st->tag = tag; } if (pd->proto == IPPROTO_TCP && (th->th_flags & (TH_SYN|TH_ACK)) == TH_SYN && r->keep_state == PF_STATE_SYNPROXY && pd->dir == PF_IN) { int rtid = pd->rdomain; if (act->rtableid >= 0) rtid = act->rtableid; pf_set_protostate(st, PF_PEER_SRC, PF_TCPS_PROXY_SRC); st->src.seqhi = arc4random(); /* Find mss option */ mss = pf_get_mss(pd); mss = pf_calc_mss(pd->src, pd->af, rtid, mss); mss = pf_calc_mss(pd->dst, pd->af, rtid, mss); st->src.mss = mss; pf_send_tcp(r, pd->af, pd->dst, pd->src, th->th_dport, th->th_sport, st->src.seqhi, ntohl(th->th_seq) + 1, TH_SYN|TH_ACK, 0, st->src.mss, 0, 1, 0, pd->rdomain); REASON_SET(&reason, PFRES_SYNPROXY); return (PF_SYNPROXY_DROP); } return (PF_PASS); csfailed: if (st) { pf_normalize_tcp_cleanup(st); /* safe even w/o init */ pf_src_tree_remove_state(st); pool_put(&pf_state_pl, st); } for (i = 0; i < PF_SN_MAX; i++) if (sns[i] != NULL) pf_remove_src_node(sns[i]); return (PF_DROP); } int pf_translate(struct pf_pdesc *pd, struct pf_addr *saddr, u_int16_t sport, struct pf_addr *daddr, u_int16_t dport, u_int16_t virtual_type, int icmp_dir) { int rewrite = 0; int afto = pd->af != pd->naf; if (afto || PF_ANEQ(daddr, pd->dst, pd->af)) pd->destchg = 1; switch (pd->proto) { case IPPROTO_TCP: /* FALLTHROUGH */ case IPPROTO_UDP: rewrite += pf_patch_16(pd, pd->sport, sport); rewrite += pf_patch_16(pd, pd->dport, dport); break; case IPPROTO_ICMP: if (pd->af != AF_INET) return (0); #ifdef INET6 if (afto) { if (pf_translate_icmp_af(pd, AF_INET6, &pd->hdr.icmp)) return (0); pd->proto = IPPROTO_ICMPV6; rewrite = 1; } #endif /* INET6 */ if (virtual_type == htons(ICMP_ECHO)) { u_int16_t icmpid = (icmp_dir == PF_IN) ? sport : dport; rewrite += pf_patch_16(pd, &pd->hdr.icmp.icmp_id, icmpid); } break; #ifdef INET6 case IPPROTO_ICMPV6: if (pd->af != AF_INET6) return (0); if (afto) { if (pf_translate_icmp_af(pd, AF_INET, &pd->hdr.icmp6)) return (0); pd->proto = IPPROTO_ICMP; rewrite = 1; } if (virtual_type == htons(ICMP6_ECHO_REQUEST)) { u_int16_t icmpid = (icmp_dir == PF_IN) ? sport : dport; rewrite += pf_patch_16(pd, &pd->hdr.icmp6.icmp6_id, icmpid); } break; #endif /* INET6 */ } if (!afto) { rewrite += pf_translate_a(pd, pd->src, saddr); rewrite += pf_translate_a(pd, pd->dst, daddr); } return (rewrite); } int pf_tcp_track_full(struct pf_pdesc *pd, struct pf_state **stp, u_short *reason, int *copyback, int reverse) { struct tcphdr *th = &pd->hdr.tcp; struct pf_state_peer *src, *dst; u_int16_t win = ntohs(th->th_win); u_int32_t ack, end, data_end, seq, orig_seq; u_int8_t sws, dws, psrc, pdst; int ackskew; if ((pd->dir == (*stp)->direction && !reverse) || (pd->dir != (*stp)->direction && reverse)) { src = &(*stp)->src; dst = &(*stp)->dst; psrc = PF_PEER_SRC; pdst = PF_PEER_DST; } else { src = &(*stp)->dst; dst = &(*stp)->src; psrc = PF_PEER_DST; pdst = PF_PEER_SRC; } if (src->wscale && dst->wscale && !(th->th_flags & TH_SYN)) { sws = src->wscale & PF_WSCALE_MASK; dws = dst->wscale & PF_WSCALE_MASK; } else sws = dws = 0; /* * Sequence tracking algorithm from Guido van Rooij's paper: * http://www.madison-gurkha.com/publications/tcp_filtering/ * tcp_filtering.ps */ orig_seq = seq = ntohl(th->th_seq); if (src->seqlo == 0) { /* First packet from this end. Set its state */ if (((*stp)->state_flags & PFSTATE_SCRUB_TCP || dst->scrub) && src->scrub == NULL) { if (pf_normalize_tcp_init(pd, src)) { 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) continue; ack = ntohl(th->th_ack) - dst->seqdiff; pf_patch_32(pd, &th->th_seq, htonl(seq + src->seqdiff)); pf_patch_32(pd, &th->th_ack, htonl(ack)); *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(pd); 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 = MIN(TCP_MAXWIN, (u_int32_t)dst->max_win << (dst->wscale & PF_WSCALE_MASK)); /* in case of a retrans SYN|ACK */ dst->wscale = 0; } } } data_end = end; if (th->th_flags & TH_FIN) end++; src->seqlo = seq; if (src->state < TCPS_SYN_SENT) pf_set_protostate(*stp, psrc, 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_patch_32(pd, &th->th_seq, htonl(seq + src->seqdiff)); pf_patch_32(pd, &th->th_ack, htonl(ack)); *copyback = 1; } end = seq + pd->p_len; if (th->th_flags & TH_SYN) end++; data_end = 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; data_end = 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 accidentally * 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(pd, dst)) *copyback = 1; } #define MAXACKWINDOW (0xffff + 1500) /* 1500 is an arbitrary fudge factor */ if (SEQ_GEQ(src->seqhi, data_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))) { /* Require an exact/+1 sequence match on resets when possible */ if (dst->scrub || src->scrub) { if (pf_normalize_tcp_stateful(pd, reason, *stp, 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) pf_set_protostate(*stp, psrc, TCPS_SYN_SENT); if (th->th_flags & TH_FIN) if (src->state < TCPS_CLOSING) pf_set_protostate(*stp, psrc, TCPS_CLOSING); if (th->th_flags & TH_ACK) { if (dst->state == TCPS_SYN_SENT) { pf_set_protostate(*stp, pdst, TCPS_ESTABLISHED); if (src->state == TCPS_ESTABLISHED && !SLIST_EMPTY(&(*stp)->src_nodes) && pf_src_connlimit(stp)) { REASON_SET(reason, PFRES_SRCLIMIT); return (PF_DROP); } } else if (dst->state == TCPS_CLOSING) pf_set_protostate(*stp, pdst, TCPS_FIN_WAIT_2); } if (th->th_flags & TH_RST) pf_set_protostate(*stp, PF_PEER_BOTH, TCPS_TIME_WAIT); /* update expire time */ (*stp)->expire = getuptime(); if (src->state >= TCPS_FIN_WAIT_2 && dst->state >= TCPS_FIN_WAIT_2) pf_update_state_timeout(*stp, PFTM_TCP_CLOSED); else if (src->state >= TCPS_CLOSING && dst->state >= TCPS_CLOSING) pf_update_state_timeout(*stp, PFTM_TCP_FIN_WAIT); else if (src->state < TCPS_ESTABLISHED || dst->state < TCPS_ESTABLISHED) pf_update_state_timeout(*stp, PFTM_TCP_OPENING); else if (src->state >= TCPS_CLOSING || dst->state >= TCPS_CLOSING) pf_update_state_timeout(*stp, PFTM_TCP_CLOSING); else pf_update_state_timeout(*stp, 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, data_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 >= LOG_NOTICE) { log(LOG_NOTICE, "pf: loose state match: "); pf_print_state(*stp); pf_print_flags(th->th_flags); addlog(" seq=%u (%u) ack=%u len=%u ackskew=%d " "pkts=%llu:%llu dir=%s,%s\n", seq, orig_seq, ack, pd->p_len, ackskew, (*stp)->packets[0], (*stp)->packets[1], pd->dir == PF_IN ? "in" : "out", pd->dir == (*stp)->direction ? "fwd" : "rev"); } if (dst->scrub || src->scrub) { if (pf_normalize_tcp_stateful(pd, reason, *stp, 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) pf_set_protostate(*stp, psrc, TCPS_CLOSING); if (th->th_flags & TH_RST) pf_set_protostate(*stp, PF_PEER_BOTH, TCPS_TIME_WAIT); /* Fall through to PASS packet */ } else { if ((*stp)->dst.state == TCPS_SYN_SENT && (*stp)->src.state == TCPS_SYN_SENT) { /* Send RST for state mismatches during handshake */ if (!(th->th_flags & TH_RST)) pf_send_tcp((*stp)->rule.ptr, pd->af, pd->dst, pd->src, th->th_dport, th->th_sport, ntohl(th->th_ack), 0, TH_RST, 0, 0, (*stp)->rule.ptr->return_ttl, 1, 0, pd->rdomain); src->seqlo = 0; src->seqhi = 1; src->max_win = 1; } else if (pf_status.debug >= LOG_NOTICE) { log(LOG_NOTICE, "pf: BAD state: "); pf_print_state(*stp); pf_print_flags(th->th_flags); addlog(" seq=%u (%u) ack=%u len=%u ackskew=%d " "pkts=%llu:%llu dir=%s,%s\n", seq, orig_seq, ack, pd->p_len, ackskew, (*stp)->packets[0], (*stp)->packets[1], pd->dir == PF_IN ? "in" : "out", pd->dir == (*stp)->direction ? "fwd" : "rev"); addlog("pf: State failure on: %c %c %c %c | %c %c\n", SEQ_GEQ(src->seqhi, data_end) ? ' ' : '1', SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)) ? ' ': '2', (ackskew >= -MAXACKWINDOW) ? ' ' : '3', (ackskew <= (MAXACKWINDOW << sws)) ? ' ' : '4', SEQ_GEQ(src->seqhi + MAXACKWINDOW, data_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_pdesc *pd, struct pf_state **stp, u_short *reason) { struct tcphdr *th = &pd->hdr.tcp; struct pf_state_peer *src, *dst; u_int8_t psrc, pdst; if (pd->dir == (*stp)->direction) { src = &(*stp)->src; dst = &(*stp)->dst; psrc = PF_PEER_SRC; pdst = PF_PEER_DST; } else { src = &(*stp)->dst; dst = &(*stp)->src; psrc = PF_PEER_DST; pdst = PF_PEER_SRC; } if (th->th_flags & TH_SYN) if (src->state < TCPS_SYN_SENT) pf_set_protostate(*stp, psrc, TCPS_SYN_SENT); if (th->th_flags & TH_FIN) if (src->state < TCPS_CLOSING) pf_set_protostate(*stp, psrc, TCPS_CLOSING); if (th->th_flags & TH_ACK) { if (dst->state == TCPS_SYN_SENT) { pf_set_protostate(*stp, pdst, TCPS_ESTABLISHED); if (src->state == TCPS_ESTABLISHED && !SLIST_EMPTY(&(*stp)->src_nodes) && pf_src_connlimit(stp)) { REASON_SET(reason, PFRES_SRCLIMIT); return (PF_DROP); } } else if (dst->state == TCPS_CLOSING) { pf_set_protostate(*stp, pdst, 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. */ pf_set_protostate(*stp, PF_PEER_BOTH, TCPS_ESTABLISHED); if (!SLIST_EMPTY(&(*stp)->src_nodes) && pf_src_connlimit(stp)) { 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. */ pf_set_protostate(*stp, pdst, TCPS_CLOSING); } } if (th->th_flags & TH_RST) pf_set_protostate(*stp, PF_PEER_BOTH, TCPS_TIME_WAIT); /* update expire time */ (*stp)->expire = getuptime(); if (src->state >= TCPS_FIN_WAIT_2 && dst->state >= TCPS_FIN_WAIT_2) pf_update_state_timeout(*stp, PFTM_TCP_CLOSED); else if (src->state >= TCPS_CLOSING && dst->state >= TCPS_CLOSING) pf_update_state_timeout(*stp, PFTM_TCP_FIN_WAIT); else if (src->state < TCPS_ESTABLISHED || dst->state < TCPS_ESTABLISHED) pf_update_state_timeout(*stp, PFTM_TCP_OPENING); else if (src->state >= TCPS_CLOSING || dst->state >= TCPS_CLOSING) pf_update_state_timeout(*stp, PFTM_TCP_CLOSING); else pf_update_state_timeout(*stp, PFTM_TCP_ESTABLISHED); return (PF_PASS); } static __inline int pf_synproxy(struct pf_pdesc *pd, struct pf_state **stp, u_short *reason) { struct pf_state_key *sk = (*stp)->key[pd->didx]; if ((*stp)->src.state == PF_TCPS_PROXY_SRC) { struct tcphdr *th = &pd->hdr.tcp; if (pd->dir != (*stp)->direction) { REASON_SET(reason, PFRES_SYNPROXY); return (PF_SYNPROXY_DROP); } if (th->th_flags & TH_SYN) { if (ntohl(th->th_seq) != (*stp)->src.seqlo) { REASON_SET(reason, PFRES_SYNPROXY); return (PF_DROP); } pf_send_tcp((*stp)->rule.ptr, pd->af, pd->dst, pd->src, th->th_dport, th->th_sport, (*stp)->src.seqhi, ntohl(th->th_seq) + 1, TH_SYN|TH_ACK, 0, (*stp)->src.mss, 0, 1, 0, pd->rdomain); REASON_SET(reason, PFRES_SYNPROXY); return (PF_SYNPROXY_DROP); } else if ((th->th_flags & (TH_ACK|TH_RST|TH_FIN)) != TH_ACK || (ntohl(th->th_ack) != (*stp)->src.seqhi + 1) || (ntohl(th->th_seq) != (*stp)->src.seqlo + 1)) { REASON_SET(reason, PFRES_SYNPROXY); return (PF_DROP); } else if (!SLIST_EMPTY(&(*stp)->src_nodes) && pf_src_connlimit(stp)) { REASON_SET(reason, PFRES_SRCLIMIT); return (PF_DROP); } else pf_set_protostate(*stp, PF_PEER_SRC, PF_TCPS_PROXY_DST); } if ((*stp)->src.state == PF_TCPS_PROXY_DST) { struct tcphdr *th = &pd->hdr.tcp; if (pd->dir == (*stp)->direction) { if (((th->th_flags & (TH_SYN|TH_ACK)) != TH_ACK) || (ntohl(th->th_ack) != (*stp)->src.seqhi + 1) || (ntohl(th->th_seq) != (*stp)->src.seqlo + 1)) { REASON_SET(reason, PFRES_SYNPROXY); return (PF_DROP); } (*stp)->src.max_win = MAX(ntohs(th->th_win), 1); if ((*stp)->dst.seqhi == 1) (*stp)->dst.seqhi = arc4random(); pf_send_tcp((*stp)->rule.ptr, pd->af, &sk->addr[pd->sidx], &sk->addr[pd->didx], sk->port[pd->sidx], sk->port[pd->didx], (*stp)->dst.seqhi, 0, TH_SYN, 0, (*stp)->src.mss, 0, 0, (*stp)->tag, sk->rdomain); 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) != (*stp)->dst.seqhi + 1)) { REASON_SET(reason, PFRES_SYNPROXY); return (PF_DROP); } else { (*stp)->dst.max_win = MAX(ntohs(th->th_win), 1); (*stp)->dst.seqlo = ntohl(th->th_seq); pf_send_tcp((*stp)->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, (*stp)->src.max_win, 0, 0, 0, (*stp)->tag, pd->rdomain); pf_send_tcp((*stp)->rule.ptr, pd->af, &sk->addr[pd->sidx], &sk->addr[pd->didx], sk->port[pd->sidx], sk->port[pd->didx], (*stp)->src.seqhi + 1, (*stp)->src.seqlo + 1, TH_ACK, (*stp)->dst.max_win, 0, 0, 1, 0, sk->rdomain); (*stp)->src.seqdiff = (*stp)->dst.seqhi - (*stp)->src.seqlo; (*stp)->dst.seqdiff = (*stp)->src.seqhi - (*stp)->dst.seqlo; (*stp)->src.seqhi = (*stp)->src.seqlo + (*stp)->dst.max_win; (*stp)->dst.seqhi = (*stp)->dst.seqlo + (*stp)->src.max_win; (*stp)->src.wscale = (*stp)->dst.wscale = 0; pf_set_protostate(*stp, PF_PEER_BOTH, TCPS_ESTABLISHED); REASON_SET(reason, PFRES_SYNPROXY); return (PF_SYNPROXY_DROP); } } return (PF_PASS); } int pf_test_state(struct pf_pdesc *pd, struct pf_state **stp, u_short *reason) { int copyback = 0; struct pf_state_peer *src, *dst; int action; struct inpcb *inp = pd->m->m_pkthdr.pf.inp; u_int8_t psrc, pdst; action = PF_PASS; if (pd->dir == (*stp)->direction) { src = &(*stp)->src; dst = &(*stp)->dst; psrc = PF_PEER_SRC; pdst = PF_PEER_DST; } else { src = &(*stp)->dst; dst = &(*stp)->src; psrc = PF_PEER_DST; pdst = PF_PEER_SRC; } switch (pd->virtual_proto) { case IPPROTO_TCP: if ((action = pf_synproxy(pd, stp, reason)) != PF_PASS) return (action); if ((pd->hdr.tcp.th_flags & (TH_SYN|TH_ACK)) == TH_SYN) { if (dst->state >= TCPS_FIN_WAIT_2 && src->state >= TCPS_FIN_WAIT_2) { if (pf_status.debug >= LOG_NOTICE) { log(LOG_NOTICE, "pf: state reuse "); pf_print_state(*stp); pf_print_flags(pd->hdr.tcp.th_flags); addlog("\n"); } /* XXX make sure it's the same direction ?? */ pf_update_state_timeout(*stp, PFTM_PURGE); pf_state_unref(*stp); *stp = NULL; pf_mbuf_link_inpcb(pd->m, inp); return (PF_DROP); } else if (dst->state >= TCPS_ESTABLISHED && src->state >= TCPS_ESTABLISHED) { /* * SYN matches existing state??? * Typically happens when sender boots up after * sudden panic. Certain protocols (NFSv3) are * always using same port numbers. Challenge * ACK enables all parties (firewall and peers) * to get in sync again. */ pf_send_challenge_ack(pd, *stp, src, dst); return (PF_DROP); } } if ((*stp)->state_flags & PFSTATE_SLOPPY) { if (pf_tcp_track_sloppy(pd, stp, reason) == PF_DROP) return (PF_DROP); } else { if (pf_tcp_track_full(pd, stp, reason, ©back, PF_REVERSED_KEY((*stp)->key, pd->af)) == PF_DROP) return (PF_DROP); } break; case IPPROTO_UDP: /* update states */ if (src->state < PFUDPS_SINGLE) pf_set_protostate(*stp, psrc, PFUDPS_SINGLE); if (dst->state == PFUDPS_SINGLE) pf_set_protostate(*stp, pdst, PFUDPS_MULTIPLE); /* update expire time */ (*stp)->expire = getuptime(); if (src->state == PFUDPS_MULTIPLE && dst->state == PFUDPS_MULTIPLE) pf_update_state_timeout(*stp, PFTM_UDP_MULTIPLE); else pf_update_state_timeout(*stp, PFTM_UDP_SINGLE); break; default: /* update states */ if (src->state < PFOTHERS_SINGLE) pf_set_protostate(*stp, psrc, PFOTHERS_SINGLE); if (dst->state == PFOTHERS_SINGLE) pf_set_protostate(*stp, pdst, PFOTHERS_MULTIPLE); /* update expire time */ (*stp)->expire = getuptime(); if (src->state == PFOTHERS_MULTIPLE && dst->state == PFOTHERS_MULTIPLE) pf_update_state_timeout(*stp, PFTM_OTHER_MULTIPLE); else pf_update_state_timeout(*stp, PFTM_OTHER_SINGLE); break; } /* translate source/destination address, if necessary */ if ((*stp)->key[PF_SK_WIRE] != (*stp)->key[PF_SK_STACK]) { struct pf_state_key *nk; int afto, sidx, didx; if (PF_REVERSED_KEY((*stp)->key, pd->af)) nk = (*stp)->key[pd->sidx]; else nk = (*stp)->key[pd->didx]; afto = pd->af != nk->af; sidx = afto ? pd->didx : pd->sidx; didx = afto ? pd->sidx : pd->didx; #ifdef INET6 if (afto) { pf_addrcpy(&pd->nsaddr, &nk->addr[sidx], nk->af); pf_addrcpy(&pd->ndaddr, &nk->addr[didx], nk->af); pd->naf = nk->af; action = PF_AFRT; } #endif /* INET6 */ if (!afto) pf_translate_a(pd, pd->src, &nk->addr[sidx]); if (pd->sport != NULL) pf_patch_16(pd, pd->sport, nk->port[sidx]); if (afto || PF_ANEQ(pd->dst, &nk->addr[didx], pd->af) || pd->rdomain != nk->rdomain) pd->destchg = 1; if (!afto) pf_translate_a(pd, pd->dst, &nk->addr[didx]); if (pd->dport != NULL) pf_patch_16(pd, pd->dport, nk->port[didx]); pd->m->m_pkthdr.ph_rtableid = nk->rdomain; copyback = 1; } if (copyback && pd->hdrlen > 0) { m_copyback(pd->m, pd->off, pd->hdrlen, &pd->hdr, M_NOWAIT); } return (action); } int pf_icmp_state_lookup(struct pf_pdesc *pd, struct pf_state_key_cmp *key, struct pf_state **stp, u_int16_t icmpid, u_int16_t type, int icmp_dir, int *iidx, int multi, int inner) { int direction, action; key->af = pd->af; key->proto = pd->proto; key->rdomain = pd->rdomain; 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 (pf_state_key_addr_setup(pd, key, pd->sidx, pd->src, pd->didx, pd->dst, pd->af, multi)) return (PF_DROP); key->hash = pf_pkt_hash(key->af, key->proto, &key->addr[0], &key->addr[1], 0, 0); action = pf_find_state(pd, key, stp); if (action != PF_MATCH) return (action); if ((*stp)->state_flags & PFSTATE_SLOPPY) return (-1); /* Is this ICMP message flowing in right direction? */ if ((*stp)->key[PF_SK_WIRE]->af != (*stp)->key[PF_SK_STACK]->af) direction = (pd->af == (*stp)->key[PF_SK_WIRE]->af) ? PF_IN : PF_OUT; else direction = (*stp)->direction; if ((((!inner && direction == pd->dir) || (inner && direction != pd->dir)) ? PF_IN : PF_OUT) != icmp_dir) { if (pf_status.debug >= LOG_NOTICE) { log(LOG_NOTICE, "pf: icmp type %d in wrong direction (%d): ", ntohs(type), icmp_dir); pf_print_state(*stp); addlog("\n"); } return (PF_DROP); } return (-1); } int pf_test_state_icmp(struct pf_pdesc *pd, struct pf_state **stp, u_short *reason) { u_int16_t virtual_id, virtual_type; u_int8_t icmptype, icmpcode; int icmp_dir, iidx, ret, copyback = 0; struct pf_state_key_cmp key; switch (pd->proto) { case IPPROTO_ICMP: icmptype = pd->hdr.icmp.icmp_type; icmpcode = pd->hdr.icmp.icmp_code; break; #ifdef INET6 case IPPROTO_ICMPV6: icmptype = pd->hdr.icmp6.icmp6_type; icmpcode = pd->hdr.icmp6.icmp6_code; break; #endif /* INET6 */ default: panic("unhandled proto %d", pd->proto); } if (pf_icmp_mapping(pd, icmptype, &icmp_dir, &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(pd, &key, stp, virtual_id, virtual_type, icmp_dir, &iidx, 0, 0); /* IPv6? try matching a multicast address */ if (ret == PF_DROP && pd->af == AF_INET6 && icmp_dir == PF_OUT) ret = pf_icmp_state_lookup(pd, &key, stp, virtual_id, virtual_type, icmp_dir, &iidx, 1, 0); if (ret >= 0) return (ret); (*stp)->expire = getuptime(); pf_update_state_timeout(*stp, PFTM_ICMP_ERROR_REPLY); /* translate source/destination address, if necessary */ if ((*stp)->key[PF_SK_WIRE] != (*stp)->key[PF_SK_STACK]) { struct pf_state_key *nk; int afto, sidx, didx; if (PF_REVERSED_KEY((*stp)->key, pd->af)) nk = (*stp)->key[pd->sidx]; else nk = (*stp)->key[pd->didx]; afto = pd->af != nk->af; sidx = afto ? pd->didx : pd->sidx; didx = afto ? pd->sidx : pd->didx; iidx = afto ? !iidx : iidx; #ifdef INET6 if (afto) { pf_addrcpy(&pd->nsaddr, &nk->addr[sidx], nk->af); pf_addrcpy(&pd->ndaddr, &nk->addr[didx], nk->af); pd->naf = nk->af; } #endif /* INET6 */ if (!afto) { pf_translate_a(pd, pd->src, &nk->addr[sidx]); pf_translate_a(pd, pd->dst, &nk->addr[didx]); } if (pd->rdomain != nk->rdomain) pd->destchg = 1; if (!afto && PF_ANEQ(pd->dst, &nk->addr[didx], pd->af)) pd->destchg = 1; pd->m->m_pkthdr.ph_rtableid = nk->rdomain; switch (pd->af) { case AF_INET: #ifdef INET6 if (afto) { if (pf_translate_icmp_af(pd, AF_INET6, &pd->hdr.icmp)) return (PF_DROP); pd->proto = IPPROTO_ICMPV6; } #endif /* INET6 */ pf_patch_16(pd, &pd->hdr.icmp.icmp_id, nk->port[iidx]); m_copyback(pd->m, pd->off, ICMP_MINLEN, &pd->hdr.icmp, M_NOWAIT); copyback = 1; break; #ifdef INET6 case AF_INET6: if (afto) { if (pf_translate_icmp_af(pd, AF_INET, &pd->hdr.icmp6)) return (PF_DROP); pd->proto = IPPROTO_ICMP; } pf_patch_16(pd, &pd->hdr.icmp6.icmp6_id, nk->port[iidx]); m_copyback(pd->m, pd->off, sizeof(struct icmp6_hdr), &pd->hdr.icmp6, M_NOWAIT); copyback = 1; break; #endif /* INET6 */ } #ifdef INET6 if (afto) return (PF_AFRT); #endif /* INET6 */ } } 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; struct ip h2; #ifdef INET6 struct ip6_hdr h2_6; #endif /* INET6 */ int ipoff2; /* Initialize pd2 fields valid for both packets with pd. */ memset(&pd2, 0, sizeof(pd2)); pd2.af = pd->af; pd2.dir = pd->dir; pd2.kif = pd->kif; pd2.m = pd->m; pd2.rdomain = pd->rdomain; /* Payload packet is from the opposite direction. */ pd2.sidx = (pd2.dir == PF_IN) ? 1 : 0; pd2.didx = (pd2.dir == PF_IN) ? 0 : 1; switch (pd->af) { case AF_INET: /* offset of h2 in mbuf chain */ ipoff2 = pd->off + ICMP_MINLEN; if (!pf_pull_hdr(pd2.m, ipoff2, &h2, sizeof(h2), reason, pd2.af)) { DPFPRINTF(LOG_NOTICE, "ICMP error message too short (ip)"); 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 */ pd2.off = ipoff2; if (pf_walk_header(&pd2, &h2, reason) != PF_PASS) return (PF_DROP); pd2.tot_len = ntohs(h2.ip_len); pd2.ttl = h2.ip_ttl; pd2.src = (struct pf_addr *)&h2.ip_src; pd2.dst = (struct pf_addr *)&h2.ip_dst; break; #ifdef INET6 case AF_INET6: ipoff2 = pd->off + sizeof(struct icmp6_hdr); if (!pf_pull_hdr(pd2.m, ipoff2, &h2_6, sizeof(h2_6), reason, pd2.af)) { DPFPRINTF(LOG_NOTICE, "ICMP error message too short (ip6)"); return (PF_DROP); } pd2.off = ipoff2; if (pf_walk_header6(&pd2, &h2_6, reason) != PF_PASS) return (PF_DROP); pd2.tot_len = ntohs(h2_6.ip6_plen) + sizeof(struct ip6_hdr); pd2.ttl = h2_6.ip6_hlim; pd2.src = (struct pf_addr *)&h2_6.ip6_src; pd2.dst = (struct pf_addr *)&h2_6.ip6_dst; break; #endif /* INET6 */ default: unhandled_af(pd->af); } if (PF_ANEQ(pd->dst, pd2.src, pd->af)) { if (pf_status.debug >= LOG_NOTICE) { log(LOG_NOTICE, "pf: BAD ICMP %d:%d outer dst: ", icmptype, icmpcode); pf_print_host(pd->src, 0, pd->af); addlog(" -> "); pf_print_host(pd->dst, 0, pd->af); addlog(" inner src: "); pf_print_host(pd2.src, 0, pd2.af); addlog(" -> "); pf_print_host(pd2.dst, 0, pd2.af); addlog("\n"); } REASON_SET(reason, PFRES_BADSTATE); return (PF_DROP); } switch (pd2.proto) { case IPPROTO_TCP: { struct tcphdr *th = &pd2.hdr.tcp; u_int32_t seq; struct pf_state_peer *src, *dst; u_int8_t dws; int action; /* * 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(pd2.m, pd2.off, th, 8, reason, pd2.af)) { DPFPRINTF(LOG_NOTICE, "ICMP error message too short (tcp)"); return (PF_DROP); } key.af = pd2.af; key.proto = IPPROTO_TCP; key.rdomain = pd2.rdomain; pf_addrcpy(&key.addr[pd2.sidx], pd2.src, key.af); pf_addrcpy(&key.addr[pd2.didx], pd2.dst, key.af); key.port[pd2.sidx] = th->th_sport; key.port[pd2.didx] = th->th_dport; key.hash = pf_pkt_hash(pd2.af, pd2.proto, pd2.src, pd2.dst, th->th_sport, th->th_dport); action = pf_find_state(&pd2, &key, stp); if (action != PF_MATCH) return (action); if (pd2.dir == (*stp)->direction) { if (PF_REVERSED_KEY((*stp)->key, pd->af)) { src = &(*stp)->src; dst = &(*stp)->dst; } else { src = &(*stp)->dst; dst = &(*stp)->src; } } else { if (PF_REVERSED_KEY((*stp)->key, pd->af)) { src = &(*stp)->dst; dst = &(*stp)->src; } else { src = &(*stp)->src; dst = &(*stp)->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_patch_32(pd, &th->th_seq, htonl(seq)); copyback = 1; } if (!((*stp)->state_flags & PFSTATE_SLOPPY) && (!SEQ_GEQ(src->seqhi, seq) || !SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)))) { if (pf_status.debug >= LOG_NOTICE) { log(LOG_NOTICE, "pf: BAD ICMP %d:%d ", icmptype, icmpcode); pf_print_host(pd->src, 0, pd->af); addlog(" -> "); pf_print_host(pd->dst, 0, pd->af); addlog(" state: "); pf_print_state(*stp); addlog(" seq=%u\n", seq); } REASON_SET(reason, PFRES_BADSTATE); return (PF_DROP); } else { if (pf_status.debug >= LOG_DEBUG) { log(LOG_DEBUG, "pf: OK ICMP %d:%d ", icmptype, icmpcode); pf_print_host(pd->src, 0, pd->af); addlog(" -> "); pf_print_host(pd->dst, 0, pd->af); addlog(" state: "); pf_print_state(*stp); addlog(" seq=%u\n", seq); } } /* translate source/destination address, if necessary */ if ((*stp)->key[PF_SK_WIRE] != (*stp)->key[PF_SK_STACK]) { struct pf_state_key *nk; int afto, sidx, didx; if (PF_REVERSED_KEY((*stp)->key, pd->af)) nk = (*stp)->key[pd->sidx]; else nk = (*stp)->key[pd->didx]; afto = pd->af != nk->af; sidx = afto ? pd2.didx : pd2.sidx; didx = afto ? pd2.sidx : pd2.didx; #ifdef INET6 if (afto) { if (pf_translate_icmp_af(pd, nk->af, &pd->hdr.icmp)) return (PF_DROP); m_copyback(pd->m, pd->off, sizeof(struct icmp6_hdr), &pd->hdr.icmp6, M_NOWAIT); if (pf_change_icmp_af(pd->m, ipoff2, pd, &pd2, &nk->addr[sidx], &nk->addr[didx], pd->af, nk->af)) return (PF_DROP); if (nk->af == AF_INET) pd->proto = IPPROTO_ICMP; else pd->proto = IPPROTO_ICMPV6; pd->m->m_pkthdr.ph_rtableid = nk->rdomain; pd->destchg = 1; pf_addrcpy(&pd->nsaddr, &nk->addr[pd2.sidx], nk->af); pf_addrcpy(&pd->ndaddr, &nk->addr[pd2.didx], nk->af); pd->naf = nk->af; pf_patch_16(pd, &th->th_sport, nk->port[sidx]); pf_patch_16(pd, &th->th_dport, nk->port[didx]); m_copyback(pd2.m, pd2.off, 8, th, M_NOWAIT); return (PF_AFRT); } #endif /* INET6 */ if (PF_ANEQ(pd2.src, &nk->addr[pd2.sidx], pd2.af) || nk->port[pd2.sidx] != th->th_sport) pf_translate_icmp(pd, pd2.src, &th->th_sport, pd->dst, &nk->addr[pd2.sidx], nk->port[pd2.sidx]); if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], pd2.af) || pd2.rdomain != nk->rdomain) pd->destchg = 1; pd->m->m_pkthdr.ph_rtableid = nk->rdomain; if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], pd2.af) || nk->port[pd2.didx] != th->th_dport) pf_translate_icmp(pd, pd2.dst, &th->th_dport, pd->src, &nk->addr[pd2.didx], nk->port[pd2.didx]); copyback = 1; } if (copyback) { switch (pd2.af) { case AF_INET: m_copyback(pd->m, pd->off, ICMP_MINLEN, &pd->hdr.icmp, M_NOWAIT); m_copyback(pd2.m, ipoff2, sizeof(h2), &h2, M_NOWAIT); break; #ifdef INET6 case AF_INET6: m_copyback(pd->m, pd->off, sizeof(struct icmp6_hdr), &pd->hdr.icmp6, M_NOWAIT); m_copyback(pd2.m, ipoff2, sizeof(h2_6), &h2_6, M_NOWAIT); break; #endif /* INET6 */ } m_copyback(pd2.m, pd2.off, 8, th, M_NOWAIT); } break; } case IPPROTO_UDP: { struct udphdr *uh = &pd2.hdr.udp; int action; if (!pf_pull_hdr(pd2.m, pd2.off, uh, sizeof(*uh), reason, pd2.af)) { DPFPRINTF(LOG_NOTICE, "ICMP error message too short (udp)"); return (PF_DROP); } key.af = pd2.af; key.proto = IPPROTO_UDP; key.rdomain = pd2.rdomain; pf_addrcpy(&key.addr[pd2.sidx], pd2.src, key.af); pf_addrcpy(&key.addr[pd2.didx], pd2.dst, key.af); key.port[pd2.sidx] = uh->uh_sport; key.port[pd2.didx] = uh->uh_dport; key.hash = pf_pkt_hash(pd2.af, pd2.proto, pd2.src, pd2.dst, uh->uh_sport, uh->uh_dport); action = pf_find_state(&pd2, &key, stp); if (action != PF_MATCH) return (action); /* translate source/destination address, if necessary */ if ((*stp)->key[PF_SK_WIRE] != (*stp)->key[PF_SK_STACK]) { struct pf_state_key *nk; int afto, sidx, didx; if (PF_REVERSED_KEY((*stp)->key, pd->af)) nk = (*stp)->key[pd->sidx]; else nk = (*stp)->key[pd->didx]; afto = pd->af != nk->af; sidx = afto ? pd2.didx : pd2.sidx; didx = afto ? pd2.sidx : pd2.didx; #ifdef INET6 if (afto) { if (pf_translate_icmp_af(pd, nk->af, &pd->hdr.icmp)) return (PF_DROP); m_copyback(pd->m, pd->off, sizeof(struct icmp6_hdr), &pd->hdr.icmp6, M_NOWAIT); if (pf_change_icmp_af(pd->m, ipoff2, pd, &pd2, &nk->addr[sidx], &nk->addr[didx], pd->af, nk->af)) return (PF_DROP); if (nk->af == AF_INET) pd->proto = IPPROTO_ICMP; else pd->proto = IPPROTO_ICMPV6; pd->m->m_pkthdr.ph_rtableid = nk->rdomain; pd->destchg = 1; pf_addrcpy(&pd->nsaddr, &nk->addr[pd2.sidx], nk->af); pf_addrcpy(&pd->ndaddr, &nk->addr[pd2.didx], nk->af); pd->naf = nk->af; pf_patch_16(pd, &uh->uh_sport, nk->port[sidx]); pf_patch_16(pd, &uh->uh_dport, nk->port[didx]); m_copyback(pd2.m, pd2.off, sizeof(*uh), uh, M_NOWAIT); return (PF_AFRT); } #endif /* INET6 */ if (PF_ANEQ(pd2.src, &nk->addr[pd2.sidx], pd2.af) || nk->port[pd2.sidx] != uh->uh_sport) pf_translate_icmp(pd, pd2.src, &uh->uh_sport, pd->dst, &nk->addr[pd2.sidx], nk->port[pd2.sidx]); if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], pd2.af) || pd2.rdomain != nk->rdomain) pd->destchg = 1; pd->m->m_pkthdr.ph_rtableid = nk->rdomain; if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], pd2.af) || nk->port[pd2.didx] != uh->uh_dport) pf_translate_icmp(pd, pd2.dst, &uh->uh_dport, pd->src, &nk->addr[pd2.didx], nk->port[pd2.didx]); switch (pd2.af) { case AF_INET: m_copyback(pd->m, pd->off, ICMP_MINLEN, &pd->hdr.icmp, M_NOWAIT); m_copyback(pd2.m, ipoff2, sizeof(h2), &h2, M_NOWAIT); break; #ifdef INET6 case AF_INET6: m_copyback(pd->m, pd->off, sizeof(struct icmp6_hdr), &pd->hdr.icmp6, M_NOWAIT); m_copyback(pd2.m, ipoff2, sizeof(h2_6), &h2_6, M_NOWAIT); break; #endif /* INET6 */ } /* Avoid recomputing quoted UDP checksum. * note: udp6 0 csum invalid per rfc2460 p27. * but presumed nothing cares in this context */ pf_patch_16(pd, &uh->uh_sum, 0); m_copyback(pd2.m, pd2.off, sizeof(*uh), uh, M_NOWAIT); copyback = 1; } break; } case IPPROTO_ICMP: { struct icmp *iih = &pd2.hdr.icmp; if (pd2.af != AF_INET) { REASON_SET(reason, PFRES_NORM); return (PF_DROP); } if (!pf_pull_hdr(pd2.m, pd2.off, iih, ICMP_MINLEN, reason, pd2.af)) { DPFPRINTF(LOG_NOTICE, "ICMP error message too short (icmp)"); return (PF_DROP); } pf_icmp_mapping(&pd2, iih->icmp_type, &icmp_dir, &virtual_id, &virtual_type); ret = pf_icmp_state_lookup(&pd2, &key, stp, virtual_id, virtual_type, icmp_dir, &iidx, 0, 1); if (ret >= 0) return (ret); /* translate source/destination address, if necessary */ if ((*stp)->key[PF_SK_WIRE] != (*stp)->key[PF_SK_STACK]) { struct pf_state_key *nk; int afto, sidx, didx; if (PF_REVERSED_KEY((*stp)->key, pd->af)) nk = (*stp)->key[pd->sidx]; else nk = (*stp)->key[pd->didx]; afto = pd->af != nk->af; sidx = afto ? pd2.didx : pd2.sidx; didx = afto ? pd2.sidx : pd2.didx; iidx = afto ? !iidx : iidx; #ifdef INET6 if (afto) { if (nk->af != AF_INET6) return (PF_DROP); if (pf_translate_icmp_af(pd, nk->af, &pd->hdr.icmp)) return (PF_DROP); m_copyback(pd->m, pd->off, sizeof(struct icmp6_hdr), &pd->hdr.icmp6, M_NOWAIT); if (pf_change_icmp_af(pd->m, ipoff2, pd, &pd2, &nk->addr[sidx], &nk->addr[didx], pd->af, nk->af)) return (PF_DROP); pd->proto = IPPROTO_ICMPV6; if (pf_translate_icmp_af(pd, nk->af, iih)) return (PF_DROP); if (virtual_type == htons(ICMP_ECHO)) pf_patch_16(pd, &iih->icmp_id, nk->port[iidx]); m_copyback(pd2.m, pd2.off, ICMP_MINLEN, iih, M_NOWAIT); pd->m->m_pkthdr.ph_rtableid = nk->rdomain; pd->destchg = 1; pf_addrcpy(&pd->nsaddr, &nk->addr[pd2.sidx], nk->af); pf_addrcpy(&pd->ndaddr, &nk->addr[pd2.didx], nk->af); pd->naf = nk->af; return (PF_AFRT); } #endif /* INET6 */ if (PF_ANEQ(pd2.src, &nk->addr[pd2.sidx], pd2.af) || (virtual_type == htons(ICMP_ECHO) && nk->port[iidx] != iih->icmp_id)) pf_translate_icmp(pd, pd2.src, (virtual_type == htons(ICMP_ECHO)) ? &iih->icmp_id : NULL, pd->dst, &nk->addr[pd2.sidx], (virtual_type == htons(ICMP_ECHO)) ? nk->port[iidx] : 0); if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], pd2.af) || pd2.rdomain != nk->rdomain) pd->destchg = 1; pd->m->m_pkthdr.ph_rtableid = nk->rdomain; if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], pd2.af)) pf_translate_icmp(pd, pd2.dst, NULL, pd->src, &nk->addr[pd2.didx], 0); m_copyback(pd->m, pd->off, ICMP_MINLEN, &pd->hdr.icmp, M_NOWAIT); m_copyback(pd2.m, ipoff2, sizeof(h2), &h2, M_NOWAIT); m_copyback(pd2.m, pd2.off, ICMP_MINLEN, iih, M_NOWAIT); copyback = 1; } break; } #ifdef INET6 case IPPROTO_ICMPV6: { struct icmp6_hdr *iih = &pd2.hdr.icmp6; if (pd2.af != AF_INET6) { REASON_SET(reason, PFRES_NORM); return (PF_DROP); } if (!pf_pull_hdr(pd2.m, pd2.off, iih, sizeof(struct icmp6_hdr), reason, pd2.af)) { DPFPRINTF(LOG_NOTICE, "ICMP error message too short (icmp6)"); return (PF_DROP); } pf_icmp_mapping(&pd2, iih->icmp6_type, &icmp_dir, &virtual_id, &virtual_type); ret = pf_icmp_state_lookup(&pd2, &key, stp, virtual_id, virtual_type, icmp_dir, &iidx, 0, 1); /* IPv6? try matching a multicast address */ if (ret == PF_DROP && pd2.af == AF_INET6 && icmp_dir == PF_OUT) ret = pf_icmp_state_lookup(&pd2, &key, stp, virtual_id, virtual_type, icmp_dir, &iidx, 1, 1); if (ret >= 0) return (ret); /* translate source/destination address, if necessary */ if ((*stp)->key[PF_SK_WIRE] != (*stp)->key[PF_SK_STACK]) { struct pf_state_key *nk; int afto, sidx, didx; if (PF_REVERSED_KEY((*stp)->key, pd->af)) nk = (*stp)->key[pd->sidx]; else nk = (*stp)->key[pd->didx]; afto = pd->af != nk->af; sidx = afto ? pd2.didx : pd2.sidx; didx = afto ? pd2.sidx : pd2.didx; iidx = afto ? !iidx : iidx; if (afto) { if (nk->af != AF_INET) return (PF_DROP); if (pf_translate_icmp_af(pd, nk->af, &pd->hdr.icmp)) return (PF_DROP); m_copyback(pd->m, pd->off, sizeof(struct icmp6_hdr), &pd->hdr.icmp6, M_NOWAIT); if (pf_change_icmp_af(pd->m, ipoff2, pd, &pd2, &nk->addr[sidx], &nk->addr[didx], pd->af, nk->af)) return (PF_DROP); pd->proto = IPPROTO_ICMP; if (pf_translate_icmp_af(pd, nk->af, iih)) return (PF_DROP); if (virtual_type == htons(ICMP6_ECHO_REQUEST)) pf_patch_16(pd, &iih->icmp6_id, nk->port[iidx]); m_copyback(pd2.m, pd2.off, sizeof(struct icmp6_hdr), iih, M_NOWAIT); pd->m->m_pkthdr.ph_rtableid = nk->rdomain; pd->destchg = 1; pf_addrcpy(&pd->nsaddr, &nk->addr[pd2.sidx], nk->af); pf_addrcpy(&pd->ndaddr, &nk->addr[pd2.didx], nk->af); pd->naf = nk->af; return (PF_AFRT); } if (PF_ANEQ(pd2.src, &nk->addr[pd2.sidx], pd2.af) || ((virtual_type == htons(ICMP6_ECHO_REQUEST)) && nk->port[pd2.sidx] != iih->icmp6_id)) pf_translate_icmp(pd, pd2.src, (virtual_type == htons(ICMP6_ECHO_REQUEST)) ? &iih->icmp6_id : NULL, pd->dst, &nk->addr[pd2.sidx], (virtual_type == htons(ICMP6_ECHO_REQUEST)) ? nk->port[iidx] : 0); if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], pd2.af) || pd2.rdomain != nk->rdomain) pd->destchg = 1; pd->m->m_pkthdr.ph_rtableid = nk->rdomain; if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], pd2.af)) pf_translate_icmp(pd, pd2.dst, NULL, pd->src, &nk->addr[pd2.didx], 0); m_copyback(pd->m, pd->off, sizeof(struct icmp6_hdr), &pd->hdr.icmp6, M_NOWAIT); m_copyback(pd2.m, ipoff2, sizeof(h2_6), &h2_6, M_NOWAIT); m_copyback(pd2.m, pd2.off, sizeof(struct icmp6_hdr), iih, M_NOWAIT); copyback = 1; } break; } #endif /* INET6 */ default: { int action; key.af = pd2.af; key.proto = pd2.proto; key.rdomain = pd2.rdomain; pf_addrcpy(&key.addr[pd2.sidx], pd2.src, key.af); pf_addrcpy(&key.addr[pd2.didx], pd2.dst, key.af); key.port[0] = key.port[1] = 0; key.hash = pf_pkt_hash(pd2.af, pd2.proto, pd2.src, pd2.dst, 0, 0); action = pf_find_state(&pd2, &key, stp); if (action != PF_MATCH) return (action); /* translate source/destination address, if necessary */ if ((*stp)->key[PF_SK_WIRE] != (*stp)->key[PF_SK_STACK]) { struct pf_state_key *nk = (*stp)->key[pd->didx]; if (PF_ANEQ(pd2.src, &nk->addr[pd2.sidx], pd2.af)) pf_translate_icmp(pd, pd2.src, NULL, pd->dst, &nk->addr[pd2.sidx], 0); if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], pd2.af) || pd2.rdomain != nk->rdomain) pd->destchg = 1; pd->m->m_pkthdr.ph_rtableid = nk->rdomain; if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx], pd2.af)) pf_translate_icmp(pd, pd2.dst, NULL, pd->src, &nk->addr[pd2.didx], 0); switch (pd2.af) { case AF_INET: m_copyback(pd->m, pd->off, ICMP_MINLEN, &pd->hdr.icmp, M_NOWAIT); m_copyback(pd2.m, ipoff2, sizeof(h2), &h2, M_NOWAIT); break; #ifdef INET6 case AF_INET6: m_copyback(pd->m, pd->off, sizeof(struct icmp6_hdr), &pd->hdr.icmp6, M_NOWAIT); m_copyback(pd2.m, ipoff2, sizeof(h2_6), &h2_6, M_NOWAIT); break; #endif /* INET6 */ } copyback = 1; } break; } } } if (copyback) { m_copyback(pd->m, pd->off, pd->hdrlen, &pd->hdr, M_NOWAIT); } 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 *reasonp, sa_family_t af) { int iplen = 0; switch (af) { case AF_INET: { struct ip *h = mtod(m, struct ip *); u_int16_t fragoff = (ntohs(h->ip_off) & IP_OFFMASK) << 3; if (fragoff) { REASON_SET(reasonp, PFRES_FRAG); return (NULL); } iplen = ntohs(h->ip_len); break; } #ifdef INET6 case AF_INET6: { struct ip6_hdr *h = mtod(m, struct ip6_hdr *); iplen = ntohs(h->ip6_plen) + sizeof(struct ip6_hdr); break; } #endif /* INET6 */ } if (m->m_pkthdr.len < off + len || iplen < off + len) { REASON_SET(reasonp, PFRES_SHORT); return (NULL); } m_copydata(m, off, len, p); return (p); } int pf_routable(struct pf_addr *addr, sa_family_t af, struct pfi_kif *kif, int rtableid) { struct sockaddr_storage ss; struct sockaddr_in *dst; int ret = 1; int check_mpath; #ifdef INET6 struct sockaddr_in6 *dst6; #endif /* INET6 */ struct rtentry *rt = NULL; check_mpath = 0; memset(&ss, 0, sizeof(ss)); switch (af) { case AF_INET: dst = (struct sockaddr_in *)&ss; 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 *)&ss; dst6->sin6_family = AF_INET6; dst6->sin6_len = sizeof(*dst6); dst6->sin6_addr = addr->v6; if (ip6_multipath) check_mpath = 1; break; #endif /* INET6 */ } /* Skip checks for ipsec interfaces */ if (kif != NULL && kif->pfik_ifp->if_type == IFT_ENC) goto out; rt = rtalloc(sstosa(&ss), 0, rtableid); if (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; do { if (rt->rt_ifidx == kif->pfik_ifp->if_index) { ret = 1; #if NCARP > 0 } else { struct ifnet *ifp; ifp = if_get(rt->rt_ifidx); if (ifp != NULL && ifp->if_type == IFT_CARP && ifp->if_carpdevidx == kif->pfik_ifp->if_index) ret = 1; if_put(ifp); #endif /* NCARP */ } rt = rtable_iterate(rt); } while (check_mpath == 1 && rt != NULL && ret == 0); } else ret = 0; out: rtfree(rt); return (ret); } int pf_rtlabel_match(struct pf_addr *addr, sa_family_t af, struct pf_addr_wrap *aw, int rtableid) { struct sockaddr_storage ss; struct sockaddr_in *dst; #ifdef INET6 struct sockaddr_in6 *dst6; #endif /* INET6 */ struct rtentry *rt; int ret = 0; memset(&ss, 0, sizeof(ss)); switch (af) { case AF_INET: dst = (struct sockaddr_in *)&ss; 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 *)&ss; dst6->sin6_family = AF_INET6; dst6->sin6_len = sizeof(*dst6); dst6->sin6_addr = addr->v6; break; #endif /* INET6 */ } rt = rtalloc(sstosa(&ss), RT_RESOLVE, rtableid); if (rt != NULL) { if (rt->rt_labelid == aw->v.rtlabel) ret = 1; rtfree(rt); } return (ret); } /* pf_route() may change pd->m, adjust local copies after calling */ void pf_route(struct pf_pdesc *pd, struct pf_state *st) { struct mbuf *m0; struct mbuf_list ml; struct sockaddr_in *dst, sin; struct rtentry *rt = NULL; struct ip *ip; struct ifnet *ifp = NULL; unsigned int rtableid; if (pd->m->m_pkthdr.pf.routed++ > 3) { m_freem(pd->m); pd->m = NULL; return; } if (st->rt == PF_DUPTO) { if ((m0 = m_dup_pkt(pd->m, max_linkhdr, M_NOWAIT)) == NULL) return; } else { if ((st->rt == PF_REPLYTO) == (st->direction == pd->dir)) return; m0 = pd->m; pd->m = NULL; } if (m0->m_len < sizeof(struct ip)) { DPFPRINTF(LOG_ERR, "%s: m0->m_len < sizeof(struct ip)", __func__); goto bad; } ip = mtod(m0, struct ip *); if (pd->dir == PF_IN) { if (ip->ip_ttl <= IPTTLDEC) { if (st->rt != PF_DUPTO) { pf_send_icmp(m0, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, 0, pd->af, st->rule.ptr, pd->rdomain); } goto bad; } ip->ip_ttl -= IPTTLDEC; } memset(&sin, 0, sizeof(sin)); dst = &sin; dst->sin_family = AF_INET; dst->sin_len = sizeof(*dst); dst->sin_addr = st->rt_addr.v4; rtableid = m0->m_pkthdr.ph_rtableid; rt = rtalloc_mpath(sintosa(dst), &ip->ip_src.s_addr, rtableid); if (!rtisvalid(rt)) { if (st->rt != PF_DUPTO) { pf_send_icmp(m0, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, pd->af, st->rule.ptr, pd->rdomain); } ipstat_inc(ips_noroute); goto bad; } ifp = if_get(rt->rt_ifidx); if (ifp == NULL) goto bad; /* A locally generated packet may have invalid source address. */ if ((ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET && (ifp->if_flags & IFF_LOOPBACK) == 0) ip->ip_src = ifatoia(rt->rt_ifa)->ia_addr.sin_addr; if (st->rt != PF_DUPTO && pd->dir == PF_IN) { if (pf_test(AF_INET, PF_OUT, ifp, &m0) != PF_PASS) goto bad; else if (m0 == NULL) goto done; if (m0->m_len < sizeof(struct ip)) { DPFPRINTF(LOG_ERR, "%s: m0->m_len < sizeof(struct ip)", __func__); goto bad; } ip = mtod(m0, struct ip *); } if (if_output_tso(ifp, &m0, sintosa(dst), rt, ifp->if_mtu) || m0 == 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_inc(ips_cantfrag); if (st->rt != PF_DUPTO) pf_send_icmp(m0, ICMP_UNREACH, ICMP_UNREACH_NEEDFRAG, ifp->if_mtu, pd->af, st->rule.ptr, pd->rdomain); goto bad; } if (ip_fragment(m0, &ml, ifp, ifp->if_mtu) || if_output_ml(ifp, &ml, sintosa(dst), rt)) goto done; ipstat_inc(ips_fragmented); done: if_put(ifp); rtfree(rt); return; bad: m_freem(m0); goto done; } #ifdef INET6 /* pf_route6() may change pd->m, adjust local copies after calling */ void pf_route6(struct pf_pdesc *pd, struct pf_state *st) { struct mbuf *m0; struct sockaddr_in6 *dst, sin6; struct rtentry *rt = NULL; struct ip6_hdr *ip6; struct ifnet *ifp = NULL; struct m_tag *mtag; unsigned int rtableid; if (pd->m->m_pkthdr.pf.routed++ > 3) { m_freem(pd->m); pd->m = NULL; return; } if (st->rt == PF_DUPTO) { if ((m0 = m_dup_pkt(pd->m, max_linkhdr, M_NOWAIT)) == NULL) return; } else { if ((st->rt == PF_REPLYTO) == (st->direction == pd->dir)) return; m0 = pd->m; pd->m = NULL; } if (m0->m_len < sizeof(struct ip6_hdr)) { DPFPRINTF(LOG_ERR, "%s: m0->m_len < sizeof(struct ip6_hdr)", __func__); goto bad; } ip6 = mtod(m0, struct ip6_hdr *); if (pd->dir == PF_IN) { if (ip6->ip6_hlim <= IPV6_HLIMDEC) { if (st->rt != PF_DUPTO) { pf_send_icmp(m0, ICMP6_TIME_EXCEEDED, ICMP6_TIME_EXCEED_TRANSIT, 0, pd->af, st->rule.ptr, pd->rdomain); } goto bad; } ip6->ip6_hlim -= IPV6_HLIMDEC; } memset(&sin6, 0, sizeof(sin6)); dst = &sin6; dst->sin6_family = AF_INET6; dst->sin6_len = sizeof(*dst); dst->sin6_addr = st->rt_addr.v6; rtableid = m0->m_pkthdr.ph_rtableid; rt = rtalloc_mpath(sin6tosa(dst), &ip6->ip6_src.s6_addr32[0], rtableid); if (!rtisvalid(rt)) { if (st->rt != PF_DUPTO) { pf_send_icmp(m0, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE, 0, pd->af, st->rule.ptr, pd->rdomain); } ip6stat_inc(ip6s_noroute); goto bad; } ifp = if_get(rt->rt_ifidx); if (ifp == NULL) goto bad; /* A locally generated packet may have invalid source address. */ if (IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && (ifp->if_flags & IFF_LOOPBACK) == 0) ip6->ip6_src = ifatoia6(rt->rt_ifa)->ia_addr.sin6_addr; if (st->rt != PF_DUPTO && pd->dir == PF_IN) { if (pf_test(AF_INET6, PF_OUT, ifp, &m0) != PF_PASS) goto bad; else if (m0 == NULL) goto done; if (m0->m_len < sizeof(struct ip6_hdr)) { DPFPRINTF(LOG_ERR, "%s: m0->m_len < sizeof(struct ip6_hdr)", __func__); goto bad; } } /* * If packet has been reassembled by PF earlier, we have to * use pf_refragment6() here to turn it back to fragments. */ if ((mtag = m_tag_find(m0, PACKET_TAG_PF_REASSEMBLED, NULL))) { (void) pf_refragment6(&m0, mtag, dst, ifp, rt); goto done; } if (if_output_tso(ifp, &m0, sin6tosa(dst), rt, ifp->if_mtu) || m0 == NULL) goto done; ip6stat_inc(ip6s_cantfrag); if (st->rt != PF_DUPTO) pf_send_icmp(m0, ICMP6_PACKET_TOO_BIG, 0, ifp->if_mtu, pd->af, st->rule.ptr, pd->rdomain); goto bad; done: if_put(ifp); rtfree(rt); return; bad: m_freem(m0); goto done; } #endif /* INET6 */ /* * check TCP 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. * if the _OUT flag is set the checksum isn't done yet, consider these ok */ int pf_check_tcp_cksum(struct mbuf *m, int off, int len, sa_family_t af) { u_int16_t sum; if (m->m_pkthdr.csum_flags & (M_TCP_CSUM_IN_OK | M_TCP_CSUM_OUT)) { return (0); } if (m->m_pkthdr.csum_flags & M_TCP_CSUM_IN_BAD || off < sizeof(struct ip) || m->m_pkthdr.len < off + len) { return (1); } /* need to do it in software */ tcpstat_inc(tcps_inswcsum); switch (af) { case AF_INET: if (m->m_len < sizeof(struct ip)) return (1); sum = in4_cksum(m, IPPROTO_TCP, off, len); break; #ifdef INET6 case AF_INET6: if (m->m_len < sizeof(struct ip6_hdr)) return (1); sum = in6_cksum(m, IPPROTO_TCP, off, len); break; #endif /* INET6 */ default: unhandled_af(af); } if (sum) { tcpstat_inc(tcps_rcvbadsum); m->m_pkthdr.csum_flags |= M_TCP_CSUM_IN_BAD; return (1); } m->m_pkthdr.csum_flags |= M_TCP_CSUM_IN_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); memset(mtag + 1, 0, sizeof(struct pf_divert)); m_tag_prepend(m, mtag); } return ((struct pf_divert *)(mtag + 1)); } int pf_walk_option(struct pf_pdesc *pd, struct ip *h, int off, int end, u_short *reason) { uint8_t type, length, opts[15 * 4 - sizeof(struct ip)]; /* IP header in payload of ICMP packet may be too short */ if (pd->m->m_pkthdr.len < end) { DPFPRINTF(LOG_NOTICE, "IP option too short"); REASON_SET(reason, PFRES_SHORT); return (PF_DROP); } KASSERT(end - off <= sizeof(opts)); m_copydata(pd->m, off, end - off, opts); end -= off; off = 0; while (off < end) { type = opts[off]; if (type == IPOPT_EOL) break; if (type == IPOPT_NOP) { off++; continue; } if (off + 2 > end) { DPFPRINTF(LOG_NOTICE, "IP length opt"); REASON_SET(reason, PFRES_IPOPTIONS); return (PF_DROP); } length = opts[off + 1]; if (length < 2) { DPFPRINTF(LOG_NOTICE, "IP short opt"); REASON_SET(reason, PFRES_IPOPTIONS); return (PF_DROP); } if (off + length > end) { DPFPRINTF(LOG_NOTICE, "IP long opt"); REASON_SET(reason, PFRES_IPOPTIONS); return (PF_DROP); } switch (type) { case IPOPT_RA: SET(pd->badopts, PF_OPT_ROUTER_ALERT); break; default: SET(pd->badopts, PF_OPT_OTHER); break; } off += length; } return (PF_PASS); } int pf_walk_header(struct pf_pdesc *pd, struct ip *h, u_short *reason) { struct ip6_ext ext; u_int32_t hlen, end; int hdr_cnt; hlen = h->ip_hl << 2; if (hlen < sizeof(struct ip) || hlen > ntohs(h->ip_len)) { REASON_SET(reason, PFRES_SHORT); return (PF_DROP); } if (hlen != sizeof(struct ip)) { if (pf_walk_option(pd, h, pd->off + sizeof(struct ip), pd->off + hlen, reason) != PF_PASS) return (PF_DROP); /* header options which contain only padding is fishy */ if (pd->badopts == 0) SET(pd->badopts, PF_OPT_OTHER); } end = pd->off + ntohs(h->ip_len); pd->off += hlen; pd->proto = h->ip_p; /* IGMP packets have router alert options, allow them */ if (pd->proto == IPPROTO_IGMP) { /* * According to RFC 1112 ttl must be set to 1 in all IGMP * packets sent to 224.0.0.1 */ if ((h->ip_ttl != 1) && (h->ip_dst.s_addr == INADDR_ALLHOSTS_GROUP)) { DPFPRINTF(LOG_NOTICE, "Invalid IGMP"); REASON_SET(reason, PFRES_IPOPTIONS); return (PF_DROP); } CLR(pd->badopts, PF_OPT_ROUTER_ALERT); } /* stop walking over non initial fragments */ if ((h->ip_off & htons(IP_OFFMASK)) != 0) return (PF_PASS); for (hdr_cnt = 0; hdr_cnt < pf_hdr_limit; hdr_cnt++) { switch (pd->proto) { case IPPROTO_AH: /* fragments may be short */ if ((h->ip_off & htons(IP_MF | IP_OFFMASK)) != 0 && end < pd->off + sizeof(ext)) return (PF_PASS); if (!pf_pull_hdr(pd->m, pd->off, &ext, sizeof(ext), reason, AF_INET)) { DPFPRINTF(LOG_NOTICE, "IP short exthdr"); return (PF_DROP); } pd->off += (ext.ip6e_len + 2) * 4; pd->proto = ext.ip6e_nxt; break; default: return (PF_PASS); } } DPFPRINTF(LOG_NOTICE, "IPv4 nested authentication header limit"); REASON_SET(reason, PFRES_IPOPTIONS); return (PF_DROP); } #ifdef INET6 int pf_walk_option6(struct pf_pdesc *pd, struct ip6_hdr *h, int off, int end, u_short *reason) { struct ip6_opt opt; struct ip6_opt_jumbo jumbo; while (off < end) { if (!pf_pull_hdr(pd->m, off, &opt.ip6o_type, sizeof(opt.ip6o_type), reason, AF_INET6)) { DPFPRINTF(LOG_NOTICE, "IPv6 short opt type"); return (PF_DROP); } if (opt.ip6o_type == IP6OPT_PAD1) { off++; continue; } if (!pf_pull_hdr(pd->m, off, &opt, sizeof(opt), reason, AF_INET6)) { DPFPRINTF(LOG_NOTICE, "IPv6 short opt"); return (PF_DROP); } if (off + sizeof(opt) + opt.ip6o_len > end) { DPFPRINTF(LOG_NOTICE, "IPv6 long opt"); REASON_SET(reason, PFRES_IPOPTIONS); return (PF_DROP); } switch (opt.ip6o_type) { case IP6OPT_PADN: break; case IP6OPT_JUMBO: SET(pd->badopts, PF_OPT_JUMBO); if (pd->jumbolen != 0) { DPFPRINTF(LOG_NOTICE, "IPv6 multiple jumbo"); REASON_SET(reason, PFRES_IPOPTIONS); return (PF_DROP); } if (ntohs(h->ip6_plen) != 0) { DPFPRINTF(LOG_NOTICE, "IPv6 bad jumbo plen"); REASON_SET(reason, PFRES_IPOPTIONS); return (PF_DROP); } if (!pf_pull_hdr(pd->m, off, &jumbo, sizeof(jumbo), reason, AF_INET6)) { DPFPRINTF(LOG_NOTICE, "IPv6 short jumbo"); return (PF_DROP); } memcpy(&pd->jumbolen, jumbo.ip6oj_jumbo_len, sizeof(pd->jumbolen)); pd->jumbolen = ntohl(pd->jumbolen); if (pd->jumbolen < IPV6_MAXPACKET) { DPFPRINTF(LOG_NOTICE, "IPv6 short jumbolen"); REASON_SET(reason, PFRES_IPOPTIONS); return (PF_DROP); } break; case IP6OPT_ROUTER_ALERT: SET(pd->badopts, PF_OPT_ROUTER_ALERT); break; default: SET(pd->badopts, PF_OPT_OTHER); break; } off += sizeof(opt) + opt.ip6o_len; } return (PF_PASS); } int pf_walk_header6(struct pf_pdesc *pd, struct ip6_hdr *h, u_short *reason) { struct ip6_frag frag; struct ip6_ext ext; struct icmp6_hdr icmp6; struct ip6_rthdr rthdr; u_int32_t end; int hdr_cnt, fraghdr_cnt = 0, rthdr_cnt = 0; pd->off += sizeof(struct ip6_hdr); end = pd->off + ntohs(h->ip6_plen); pd->fragoff = pd->extoff = pd->jumbolen = 0; pd->proto = h->ip6_nxt; for (hdr_cnt = 0; hdr_cnt < pf_hdr_limit; hdr_cnt++) { switch (pd->proto) { case IPPROTO_ROUTING: case IPPROTO_DSTOPTS: SET(pd->badopts, PF_OPT_OTHER); break; case IPPROTO_HOPOPTS: if (!pf_pull_hdr(pd->m, pd->off, &ext, sizeof(ext), reason, AF_INET6)) { DPFPRINTF(LOG_NOTICE, "IPv6 short exthdr"); return (PF_DROP); } if (pf_walk_option6(pd, h, pd->off + sizeof(ext), pd->off + (ext.ip6e_len + 1) * 8, reason) != PF_PASS) return (PF_DROP); /* option header which contains only padding is fishy */ if (pd->badopts == 0) SET(pd->badopts, PF_OPT_OTHER); break; } switch (pd->proto) { case IPPROTO_FRAGMENT: if (fraghdr_cnt++) { DPFPRINTF(LOG_NOTICE, "IPv6 multiple fragment"); REASON_SET(reason, PFRES_FRAG); return (PF_DROP); } /* jumbo payload packets cannot be fragmented */ if (pd->jumbolen != 0) { DPFPRINTF(LOG_NOTICE, "IPv6 fragmented jumbo"); REASON_SET(reason, PFRES_FRAG); return (PF_DROP); } if (!pf_pull_hdr(pd->m, pd->off, &frag, sizeof(frag), reason, AF_INET6)) { DPFPRINTF(LOG_NOTICE, "IPv6 short fragment"); return (PF_DROP); } /* stop walking over non initial fragments */ if (ntohs((frag.ip6f_offlg & IP6F_OFF_MASK)) != 0) { pd->fragoff = pd->off; return (PF_PASS); } /* RFC6946: reassemble only non atomic fragments */ if (frag.ip6f_offlg & IP6F_MORE_FRAG) pd->fragoff = pd->off; pd->off += sizeof(frag); pd->proto = frag.ip6f_nxt; break; case IPPROTO_ROUTING: if (rthdr_cnt++) { DPFPRINTF(LOG_NOTICE, "IPv6 multiple rthdr"); REASON_SET(reason, PFRES_IPOPTIONS); return (PF_DROP); } /* fragments may be short */ if (pd->fragoff != 0 && end < pd->off + sizeof(rthdr)) { pd->off = pd->fragoff; pd->proto = IPPROTO_FRAGMENT; return (PF_PASS); } if (!pf_pull_hdr(pd->m, pd->off, &rthdr, sizeof(rthdr), reason, AF_INET6)) { DPFPRINTF(LOG_NOTICE, "IPv6 short rthdr"); return (PF_DROP); } if (rthdr.ip6r_type == IPV6_RTHDR_TYPE_0) { DPFPRINTF(LOG_NOTICE, "IPv6 rthdr0"); REASON_SET(reason, PFRES_IPOPTIONS); return (PF_DROP); } /* FALLTHROUGH */ case IPPROTO_HOPOPTS: /* RFC2460 4.1: Hop-by-Hop only after IPv6 header */ if (pd->proto == IPPROTO_HOPOPTS && hdr_cnt > 0) { DPFPRINTF(LOG_NOTICE, "IPv6 hopopts not first"); REASON_SET(reason, PFRES_IPOPTIONS); return (PF_DROP); } /* FALLTHROUGH */ case IPPROTO_AH: case IPPROTO_DSTOPTS: /* fragments may be short */ if (pd->fragoff != 0 && end < pd->off + sizeof(ext)) { pd->off = pd->fragoff; pd->proto = IPPROTO_FRAGMENT; return (PF_PASS); } if (!pf_pull_hdr(pd->m, pd->off, &ext, sizeof(ext), reason, AF_INET6)) { DPFPRINTF(LOG_NOTICE, "IPv6 short exthdr"); return (PF_DROP); } /* reassembly needs the ext header before the frag */ if (pd->fragoff == 0) pd->extoff = pd->off; if (pd->proto == IPPROTO_HOPOPTS && pd->fragoff == 0 && ntohs(h->ip6_plen) == 0 && pd->jumbolen != 0) { DPFPRINTF(LOG_NOTICE, "IPv6 missing jumbo"); REASON_SET(reason, PFRES_IPOPTIONS); return (PF_DROP); } if (pd->proto == IPPROTO_AH) pd->off += (ext.ip6e_len + 2) * 4; else pd->off += (ext.ip6e_len + 1) * 8; pd->proto = ext.ip6e_nxt; break; case IPPROTO_ICMPV6: /* fragments may be short, ignore inner header then */ if (pd->fragoff != 0 && end < pd->off + sizeof(icmp6)) { pd->off = pd->fragoff; pd->proto = IPPROTO_FRAGMENT; return (PF_PASS); } if (!pf_pull_hdr(pd->m, pd->off, &icmp6, sizeof(icmp6), reason, AF_INET6)) { DPFPRINTF(LOG_NOTICE, "IPv6 short icmp6hdr"); return (PF_DROP); } /* ICMP multicast packets have router alert options */ switch (icmp6.icmp6_type) { case MLD_LISTENER_QUERY: case MLD_LISTENER_REPORT: case MLD_LISTENER_DONE: case MLDV2_LISTENER_REPORT: /* * According to RFC 2710 all MLD messages are * sent with hop-limit (ttl) set to 1, and link * local source address. If either one is * missing then MLD message is invalid and * should be discarded. */ if ((h->ip6_hlim != 1) || !IN6_IS_ADDR_LINKLOCAL(&h->ip6_src)) { DPFPRINTF(LOG_NOTICE, "Invalid MLD"); REASON_SET(reason, PFRES_IPOPTIONS); return (PF_DROP); } CLR(pd->badopts, PF_OPT_ROUTER_ALERT); break; } return (PF_PASS); case IPPROTO_TCP: case IPPROTO_UDP: /* fragments may be short, ignore inner header then */ if (pd->fragoff != 0 && end < pd->off + (pd->proto == IPPROTO_TCP ? sizeof(struct tcphdr) : pd->proto == IPPROTO_UDP ? sizeof(struct udphdr) : sizeof(struct icmp6_hdr))) { pd->off = pd->fragoff; pd->proto = IPPROTO_FRAGMENT; } /* FALLTHROUGH */ default: return (PF_PASS); } } DPFPRINTF(LOG_NOTICE, "IPv6 nested extension header limit"); REASON_SET(reason, PFRES_IPOPTIONS); return (PF_DROP); } #endif /* INET6 */ u_int16_t pf_pkt_hash(sa_family_t af, uint8_t proto, const struct pf_addr *src, const struct pf_addr *dst, uint16_t sport, uint16_t dport) { uint32_t hash; hash = src->addr32[0] ^ dst->addr32[0]; #ifdef INET6 if (af == AF_INET6) { hash ^= src->addr32[1] ^ dst->addr32[1]; hash ^= src->addr32[2] ^ dst->addr32[2]; hash ^= src->addr32[3] ^ dst->addr32[3]; } #endif switch (proto) { case IPPROTO_TCP: case IPPROTO_UDP: hash ^= sport ^ dport; break; } return stoeplitz_n32(hash); } int pf_setup_pdesc(struct pf_pdesc *pd, sa_family_t af, int dir, struct pfi_kif *kif, struct mbuf *m, u_short *reason) { memset(pd, 0, sizeof(*pd)); pd->dir = dir; pd->kif = kif; /* kif is NULL when called by pflog */ pd->m = m; pd->sidx = (dir == PF_IN) ? 0 : 1; pd->didx = (dir == PF_IN) ? 1 : 0; pd->af = pd->naf = af; pd->rdomain = rtable_l2(pd->m->m_pkthdr.ph_rtableid); switch (pd->af) { case AF_INET: { struct ip *h; /* Check for illegal packets */ if (pd->m->m_pkthdr.len < (int)sizeof(struct ip)) { REASON_SET(reason, PFRES_SHORT); return (PF_DROP); } h = mtod(pd->m, struct ip *); if (pd->m->m_pkthdr.len < ntohs(h->ip_len)) { REASON_SET(reason, PFRES_SHORT); return (PF_DROP); } if (pf_walk_header(pd, h, reason) != PF_PASS) return (PF_DROP); pd->src = (struct pf_addr *)&h->ip_src; pd->dst = (struct pf_addr *)&h->ip_dst; pd->tot_len = ntohs(h->ip_len); pd->tos = h->ip_tos & ~IPTOS_ECN_MASK; pd->ttl = h->ip_ttl; pd->virtual_proto = (h->ip_off & htons(IP_MF | IP_OFFMASK)) ? PF_VPROTO_FRAGMENT : pd->proto; break; } #ifdef INET6 case AF_INET6: { struct ip6_hdr *h; /* Check for illegal packets */ if (pd->m->m_pkthdr.len < (int)sizeof(struct ip6_hdr)) { REASON_SET(reason, PFRES_SHORT); return (PF_DROP); } h = mtod(pd->m, struct ip6_hdr *); if (pd->m->m_pkthdr.len < sizeof(struct ip6_hdr) + ntohs(h->ip6_plen)) { REASON_SET(reason, PFRES_SHORT); return (PF_DROP); } if (pf_walk_header6(pd, h, reason) != PF_PASS) return (PF_DROP); #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 (pd->jumbolen != 0) { REASON_SET(reason, PFRES_NORM); return (PF_DROP); } #endif /* 1 */ pd->src = (struct pf_addr *)&h->ip6_src; pd->dst = (struct pf_addr *)&h->ip6_dst; pd->tot_len = ntohs(h->ip6_plen) + sizeof(struct ip6_hdr); pd->tos = (ntohl(h->ip6_flow) & 0x0fc00000) >> 20; pd->ttl = h->ip6_hlim; pd->virtual_proto = (pd->fragoff != 0) ? PF_VPROTO_FRAGMENT : pd->proto; break; } #endif /* INET6 */ default: panic("pf_setup_pdesc called with illegal af %u", pd->af); } pf_addrcpy(&pd->nsaddr, pd->src, pd->af); pf_addrcpy(&pd->ndaddr, pd->dst, pd->af); switch (pd->virtual_proto) { case IPPROTO_TCP: { struct tcphdr *th = &pd->hdr.tcp; if (!pf_pull_hdr(pd->m, pd->off, th, sizeof(*th), reason, pd->af)) return (PF_DROP); pd->hdrlen = sizeof(*th); if (th->th_dport == 0 || pd->off + (th->th_off << 2) > pd->tot_len || (th->th_off << 2) < sizeof(struct tcphdr)) { REASON_SET(reason, PFRES_SHORT); return (PF_DROP); } pd->p_len = pd->tot_len - pd->off - (th->th_off << 2); pd->sport = &th->th_sport; pd->dport = &th->th_dport; pd->pcksum = &th->th_sum; break; } case IPPROTO_UDP: { struct udphdr *uh = &pd->hdr.udp; if (!pf_pull_hdr(pd->m, pd->off, uh, sizeof(*uh), reason, pd->af)) return (PF_DROP); pd->hdrlen = sizeof(*uh); if (uh->uh_dport == 0 || pd->off + ntohs(uh->uh_ulen) > pd->tot_len || ntohs(uh->uh_ulen) < sizeof(struct udphdr)) { REASON_SET(reason, PFRES_SHORT); return (PF_DROP); } pd->sport = &uh->uh_sport; pd->dport = &uh->uh_dport; pd->pcksum = &uh->uh_sum; break; } case IPPROTO_ICMP: { if (!pf_pull_hdr(pd->m, pd->off, &pd->hdr.icmp, ICMP_MINLEN, reason, pd->af)) return (PF_DROP); pd->hdrlen = ICMP_MINLEN; if (pd->off + pd->hdrlen > pd->tot_len) { REASON_SET(reason, PFRES_SHORT); return (PF_DROP); } pd->pcksum = &pd->hdr.icmp.icmp_cksum; break; } #ifdef INET6 case IPPROTO_ICMPV6: { size_t icmp_hlen = sizeof(struct icmp6_hdr); if (!pf_pull_hdr(pd->m, pd->off, &pd->hdr.icmp6, icmp_hlen, reason, pd->af)) return (PF_DROP); /* ICMP headers we look further into to match state */ switch (pd->hdr.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); /* FALLTHROUGH */ case ND_ROUTER_SOLICIT: case ND_ROUTER_ADVERT: case ND_REDIRECT: if (pd->ttl != 255) { REASON_SET(reason, PFRES_NORM); return (PF_DROP); } break; } if (icmp_hlen > sizeof(struct icmp6_hdr) && !pf_pull_hdr(pd->m, pd->off, &pd->hdr.icmp6, icmp_hlen, reason, pd->af)) return (PF_DROP); pd->hdrlen = icmp_hlen; if (pd->off + pd->hdrlen > pd->tot_len) { REASON_SET(reason, PFRES_SHORT); return (PF_DROP); } pd->pcksum = &pd->hdr.icmp6.icmp6_cksum; break; } #endif /* INET6 */ } if (pd->sport) pd->osport = pd->nsport = *pd->sport; if (pd->dport) pd->odport = pd->ndport = *pd->dport; pd->hash = pf_pkt_hash(pd->af, pd->proto, pd->src, pd->dst, pd->osport, pd->odport); return (PF_PASS); } void pf_counters_inc(int action, struct pf_pdesc *pd, struct pf_state *st, struct pf_rule *r, struct pf_rule *a) { int dirndx; pd->kif->pfik_bytes[pd->af == AF_INET6][pd->dir == PF_OUT] [action != PF_PASS] += pd->tot_len; pd->kif->pfik_packets[pd->af == AF_INET6][pd->dir == PF_OUT] [action != PF_PASS]++; if (action == PF_PASS || action == PF_AFRT || r->action == PF_DROP) { dirndx = (pd->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 (st != NULL) { struct pf_rule_item *ri; struct pf_sn_item *sni; SLIST_FOREACH(sni, &st->src_nodes, next) { sni->sn->packets[dirndx]++; sni->sn->bytes[dirndx] += pd->tot_len; } dirndx = (pd->dir == st->direction) ? 0 : 1; st->packets[dirndx]++; st->bytes[dirndx] += pd->tot_len; SLIST_FOREACH(ri, &st->match_rules, entry) { ri->r->packets[dirndx]++; ri->r->bytes[dirndx] += pd->tot_len; if (ri->r->src.addr.type == PF_ADDR_TABLE) pfr_update_stats(ri->r->src.addr.p.tbl, &st->key[(st->direction == PF_IN)]-> addr[(st->direction == PF_OUT)], pd, ri->r->action, ri->r->src.neg); if (ri->r->dst.addr.type == PF_ADDR_TABLE) pfr_update_stats(ri->r->dst.addr.p.tbl, &st->key[(st->direction == PF_IN)]-> addr[(st->direction == PF_IN)], pd, ri->r->action, ri->r->dst.neg); } } if (r->src.addr.type == PF_ADDR_TABLE) pfr_update_stats(r->src.addr.p.tbl, (st == NULL) ? pd->src : &st->key[(st->direction == PF_IN)]-> addr[(st->direction == PF_OUT)], pd, r->action, r->src.neg); if (r->dst.addr.type == PF_ADDR_TABLE) pfr_update_stats(r->dst.addr.p.tbl, (st == NULL) ? pd->dst : &st->key[(st->direction == PF_IN)]-> addr[(st->direction == PF_IN)], pd, r->action, r->dst.neg); } } int pf_test(sa_family_t af, int fwdir, struct ifnet *ifp, struct mbuf **m0) { #if NCARP > 0 struct ifnet *ifp0; #endif struct pfi_kif *kif; u_short action, reason = 0; struct pf_rule *a = NULL, *r = &pf_default_rule; struct pf_state *st = NULL; struct pf_state_key_cmp key; struct pf_ruleset *ruleset = NULL; struct pf_pdesc pd; int dir = (fwdir == PF_FWD) ? PF_OUT : fwdir; u_int32_t qid, pqid = 0; int have_pf_lock = 0; if (!pf_status.running) return (PF_PASS); #if NCARP > 0 if (ifp->if_type == IFT_CARP && (ifp0 = if_get(ifp->if_carpdevidx)) != NULL) { kif = (struct pfi_kif *)ifp0->if_pf_kif; if_put(ifp0); } else #endif /* NCARP */ kif = (struct pfi_kif *)ifp->if_pf_kif; if (kif == NULL) { DPFPRINTF(LOG_ERR, "%s: kif == NULL, if_xname %s", __func__, ifp->if_xname); return (PF_DROP); } if (kif->pfik_flags & PFI_IFLAG_SKIP) return (PF_PASS); #ifdef DIAGNOSTIC if (((*m0)->m_flags & M_PKTHDR) == 0) panic("non-M_PKTHDR is passed to pf_test"); #endif /* DIAGNOSTIC */ if ((*m0)->m_pkthdr.pf.flags & PF_TAG_GENERATED) return (PF_PASS); if ((*m0)->m_pkthdr.pf.flags & PF_TAG_DIVERTED_PACKET) { (*m0)->m_pkthdr.pf.flags &= ~PF_TAG_DIVERTED_PACKET; return (PF_PASS); } if ((*m0)->m_pkthdr.pf.flags & PF_TAG_REFRAGMENTED) { (*m0)->m_pkthdr.pf.flags &= ~PF_TAG_REFRAGMENTED; return (PF_PASS); } action = pf_setup_pdesc(&pd, af, dir, kif, *m0, &reason); if (action != PF_PASS) { #if NPFLOG > 0 pd.pflog |= PF_LOG_FORCE; #endif /* NPFLOG > 0 */ goto done; } /* packet normalization and reassembly */ switch (pd.af) { case AF_INET: action = pf_normalize_ip(&pd, &reason); break; #ifdef INET6 case AF_INET6: action = pf_normalize_ip6(&pd, &reason); break; #endif /* INET6 */ } *m0 = pd.m; /* if packet sits in reassembly queue, return without error */ if (pd.m == NULL) return PF_PASS; if (action != PF_PASS) { #if NPFLOG > 0 pd.pflog |= PF_LOG_FORCE; #endif /* NPFLOG > 0 */ goto done; } /* if packet has been reassembled, update packet description */ if (pf_status.reass && pd.virtual_proto == PF_VPROTO_FRAGMENT) { action = pf_setup_pdesc(&pd, af, dir, kif, pd.m, &reason); if (action != PF_PASS) { #if NPFLOG > 0 pd.pflog |= PF_LOG_FORCE; #endif /* NPFLOG > 0 */ goto done; } } pd.m->m_pkthdr.pf.flags |= PF_TAG_PROCESSED; /* * Avoid pcb-lookups from the forwarding path. They should never * match and would cause MP locking problems. */ if (fwdir == PF_FWD) { pd.lookup.done = -1; pd.lookup.uid = -1; pd.lookup.gid = -1; pd.lookup.pid = NO_PID; } switch (pd.virtual_proto) { case PF_VPROTO_FRAGMENT: { /* * handle fragments that aren't reassembled by * normalization */ PF_LOCK(); have_pf_lock = 1; action = pf_test_rule(&pd, &r, &st, &a, &ruleset, &reason); st = pf_state_ref(st); if (action != PF_PASS) REASON_SET(&reason, PFRES_FRAG); break; } case IPPROTO_ICMP: { if (pd.af != AF_INET) { action = PF_DROP; REASON_SET(&reason, PFRES_NORM); DPFPRINTF(LOG_NOTICE, "dropping IPv6 packet with ICMPv4 payload"); break; } PF_STATE_ENTER_READ(); action = pf_test_state_icmp(&pd, &st, &reason); st = pf_state_ref(st); PF_STATE_EXIT_READ(); if (action == PF_PASS || action == PF_AFRT) { #if NPFSYNC > 0 pfsync_update_state(st); #endif /* NPFSYNC > 0 */ r = st->rule.ptr; a = st->anchor.ptr; #if NPFLOG > 0 pd.pflog |= st->log; #endif /* NPFLOG > 0 */ } else if (st == NULL) { PF_LOCK(); have_pf_lock = 1; action = pf_test_rule(&pd, &r, &st, &a, &ruleset, &reason); st = pf_state_ref(st); } break; } #ifdef INET6 case IPPROTO_ICMPV6: { if (pd.af != AF_INET6) { action = PF_DROP; REASON_SET(&reason, PFRES_NORM); DPFPRINTF(LOG_NOTICE, "dropping IPv4 packet with ICMPv6 payload"); break; } PF_STATE_ENTER_READ(); action = pf_test_state_icmp(&pd, &st, &reason); st = pf_state_ref(st); PF_STATE_EXIT_READ(); if (action == PF_PASS || action == PF_AFRT) { #if NPFSYNC > 0 pfsync_update_state(st); #endif /* NPFSYNC > 0 */ r = st->rule.ptr; a = st->anchor.ptr; #if NPFLOG > 0 pd.pflog |= st->log; #endif /* NPFLOG > 0 */ } else if (st == NULL) { PF_LOCK(); have_pf_lock = 1; action = pf_test_rule(&pd, &r, &st, &a, &ruleset, &reason); st = pf_state_ref(st); } break; } #endif /* INET6 */ default: if (pd.virtual_proto == IPPROTO_TCP) { if (pd.dir == PF_IN && (pd.hdr.tcp.th_flags & (TH_SYN|TH_ACK)) == TH_SYN && pf_synflood_check(&pd)) { PF_LOCK(); have_pf_lock = 1; pf_syncookie_send(&pd); action = PF_DROP; break; } if ((pd.hdr.tcp.th_flags & TH_ACK) && pd.p_len == 0) pqid = 1; action = pf_normalize_tcp(&pd); if (action == PF_DROP) break; } key.af = pd.af; key.proto = pd.virtual_proto; key.rdomain = pd.rdomain; pf_addrcpy(&key.addr[pd.sidx], pd.src, key.af); pf_addrcpy(&key.addr[pd.didx], pd.dst, key.af); key.port[pd.sidx] = pd.osport; key.port[pd.didx] = pd.odport; key.hash = pd.hash; PF_STATE_ENTER_READ(); action = pf_find_state(&pd, &key, &st); st = pf_state_ref(st); PF_STATE_EXIT_READ(); /* check for syncookies if tcp ack and no active state */ if (pd.dir == PF_IN && pd.virtual_proto == IPPROTO_TCP && (st == NULL || (st->src.state >= TCPS_FIN_WAIT_2 && st->dst.state >= TCPS_FIN_WAIT_2)) && (pd.hdr.tcp.th_flags & (TH_SYN|TH_ACK|TH_RST)) == TH_ACK && pf_syncookie_validate(&pd)) { struct mbuf *msyn = pf_syncookie_recreate_syn(&pd); if (msyn) { action = pf_test(af, fwdir, ifp, &msyn); m_freem(msyn); if (action == PF_PASS || action == PF_AFRT) { PF_STATE_ENTER_READ(); pf_state_unref(st); action = pf_find_state(&pd, &key, &st); st = pf_state_ref(st); PF_STATE_EXIT_READ(); if (st == NULL) return (PF_DROP); st->src.seqhi = st->dst.seqhi = ntohl(pd.hdr.tcp.th_ack) - 1; st->src.seqlo = ntohl(pd.hdr.tcp.th_seq) - 1; pf_set_protostate(st, PF_PEER_SRC, PF_TCPS_PROXY_DST); } } else action = PF_DROP; } if (action == PF_MATCH) action = pf_test_state(&pd, &st, &reason); if (action == PF_PASS || action == PF_AFRT) { #if NPFSYNC > 0 pfsync_update_state(st); #endif /* NPFSYNC > 0 */ r = st->rule.ptr; a = st->anchor.ptr; #if NPFLOG > 0 pd.pflog |= st->log; #endif /* NPFLOG > 0 */ } else if (st == NULL) { PF_LOCK(); have_pf_lock = 1; action = pf_test_rule(&pd, &r, &st, &a, &ruleset, &reason); st = pf_state_ref(st); } if (pd.virtual_proto == IPPROTO_TCP) { if (st) { if (st->max_mss) pf_normalize_mss(&pd, st->max_mss); } else if (r->max_mss) pf_normalize_mss(&pd, r->max_mss); } break; } if (have_pf_lock != 0) PF_UNLOCK(); /* * At the moment, we rely on NET_LOCK() to prevent removal of items * we've collected above ('r', 'anchor' and 'ruleset'). They'll have * to be refcounted when NET_LOCK() is gone. */ done: if (action != PF_DROP) { if (st) { /* The non-state case is handled in pf_test_rule() */ if (action == PF_PASS && pd.badopts != 0 && !(st->state_flags & PFSTATE_ALLOWOPTS)) { action = PF_DROP; REASON_SET(&reason, PFRES_IPOPTIONS); #if NPFLOG > 0 pd.pflog |= PF_LOG_FORCE; #endif /* NPFLOG > 0 */ DPFPRINTF(LOG_NOTICE, "dropping packet with " "ip/ipv6 options in pf_test()"); } pf_scrub(pd.m, st->state_flags, pd.af, st->min_ttl, st->set_tos); pf_tag_packet(pd.m, st->tag, st->rtableid[pd.didx]); if (pqid || (pd.tos & IPTOS_LOWDELAY)) { qid = st->pqid; if (st->state_flags & PFSTATE_SETPRIO) { pd.m->m_pkthdr.pf.prio = st->set_prio[1]; } } else { qid = st->qid; if (st->state_flags & PFSTATE_SETPRIO) { pd.m->m_pkthdr.pf.prio = st->set_prio[0]; } } pd.m->m_pkthdr.pf.delay = st->delay; } else { pf_scrub(pd.m, r->scrub_flags, pd.af, r->min_ttl, r->set_tos); if (pqid || (pd.tos & IPTOS_LOWDELAY)) { qid = r->pqid; if (r->scrub_flags & PFSTATE_SETPRIO) pd.m->m_pkthdr.pf.prio = r->set_prio[1]; } else { qid = r->qid; if (r->scrub_flags & PFSTATE_SETPRIO) pd.m->m_pkthdr.pf.prio = r->set_prio[0]; } pd.m->m_pkthdr.pf.delay = r->delay; } } if (action == PF_PASS && qid) pd.m->m_pkthdr.pf.qid = qid; if (pd.dir == PF_IN && st && st->key[PF_SK_STACK]) pf_mbuf_link_state_key(pd.m, st->key[PF_SK_STACK]); if (pd.dir == PF_OUT && st && st->key[PF_SK_STACK]) pf_state_key_link_inpcb(st->key[PF_SK_STACK], pd.m->m_pkthdr.pf.inp); if (st != NULL && !ISSET(pd.m->m_pkthdr.csum_flags, M_FLOWID)) { pd.m->m_pkthdr.ph_flowid = st->key[PF_SK_WIRE]->hash; SET(pd.m->m_pkthdr.csum_flags, M_FLOWID); } /* * connections redirected to loopback should not match sockets * bound specifically to loopback due to security implications, * see in_pcblookup_listen(). */ if (pd.destchg) if ((pd.af == AF_INET && (ntohl(pd.dst->v4.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) || (pd.af == AF_INET6 && IN6_IS_ADDR_LOOPBACK(&pd.dst->v6))) pd.m->m_pkthdr.pf.flags |= PF_TAG_TRANSLATE_LOCALHOST; /* We need to redo the route lookup on outgoing routes. */ if (pd.destchg && pd.dir == PF_OUT) pd.m->m_pkthdr.pf.flags |= PF_TAG_REROUTE; if (pd.dir == PF_IN && action == PF_PASS && (r->divert.type == PF_DIVERT_TO || r->divert.type == PF_DIVERT_REPLY)) { struct pf_divert *divert; if ((divert = pf_get_divert(pd.m))) { pd.m->m_pkthdr.pf.flags |= PF_TAG_DIVERTED; divert->addr = r->divert.addr; divert->port = r->divert.port; divert->rdomain = pd.rdomain; divert->type = r->divert.type; } } if (action == PF_PASS && r->divert.type == PF_DIVERT_PACKET) action = PF_DIVERT; #if NPFLOG > 0 if (pd.pflog) { struct pf_rule_item *ri; if (pd.pflog & PF_LOG_FORCE || r->log & PF_LOG_ALL) pflog_packet(&pd, reason, r, a, ruleset, NULL); if (st) { SLIST_FOREACH(ri, &st->match_rules, entry) if (ri->r->log & PF_LOG_ALL) pflog_packet(&pd, reason, ri->r, a, ruleset, NULL); } } #endif /* NPFLOG > 0 */ pf_counters_inc(action, &pd, st, r, a); switch (action) { case PF_SYNPROXY_DROP: m_freem(pd.m); /* FALLTHROUGH */ case PF_DEFER: pd.m = NULL; action = PF_PASS; break; case PF_DIVERT: switch (pd.af) { case AF_INET: divert_packet(pd.m, pd.dir, r->divert.port); pd.m = NULL; break; #ifdef INET6 case AF_INET6: divert6_packet(pd.m, pd.dir, r->divert.port); pd.m = NULL; break; #endif /* INET6 */ } action = PF_PASS; break; #ifdef INET6 case PF_AFRT: if (pf_translate_af(&pd)) { action = PF_DROP; goto out; } pd.m->m_pkthdr.pf.flags |= PF_TAG_GENERATED; switch (pd.naf) { case AF_INET: if (pd.dir == PF_IN) { int flags = IP_REDIRECT; switch (atomic_load_int(&ip_forwarding)) { case 2: SET(flags, IP_FORWARDING_IPSEC); /* FALLTHROUGH */ case 1: SET(flags, IP_FORWARDING); break; default: ipstat_inc(ips_cantforward); action = PF_DROP; goto out; } if (atomic_load_int(&ip_directedbcast)) SET(flags, IP_ALLOWBROADCAST); ip_forward(pd.m, ifp, NULL, flags); } else ip_output(pd.m, NULL, NULL, 0, NULL, NULL, 0); break; case AF_INET6: if (pd.dir == PF_IN) { int flags = IPV6_REDIRECT; switch (atomic_load_int(&ip6_forwarding)) { case 2: SET(flags, IPV6_FORWARDING_IPSEC); /* FALLTHROUGH */ case 1: SET(flags, IPV6_FORWARDING); break; default: ip6stat_inc(ip6s_cantforward); action = PF_DROP; goto out; } ip6_forward(pd.m, NULL, flags); } else ip6_output(pd.m, NULL, NULL, 0, NULL, NULL); break; } pd.m = NULL; action = PF_PASS; break; #endif /* INET6 */ case PF_DROP: m_freem(pd.m); pd.m = NULL; break; default: if (st && st->rt) { switch (pd.af) { case AF_INET: pf_route(&pd, st); break; #ifdef INET6 case AF_INET6: pf_route6(&pd, st); break; #endif /* INET6 */ } } break; } #ifdef INET6 /* if reassembled packet passed, create new fragments */ if (pf_status.reass && action == PF_PASS && pd.m && fwdir == PF_FWD && pd.af == AF_INET6) { struct m_tag *mtag; if ((mtag = m_tag_find(pd.m, PACKET_TAG_PF_REASSEMBLED, NULL))) action = pf_refragment6(&pd.m, mtag, NULL, NULL, NULL); } #endif /* INET6 */ if (st && action != PF_DROP) { if (!st->if_index_in && dir == PF_IN) st->if_index_in = ifp->if_index; else if (!st->if_index_out && dir == PF_OUT) st->if_index_out = ifp->if_index; } out: *m0 = pd.m; pf_state_unref(st); return (action); } int pf_ouraddr(struct mbuf *m) { struct pf_state_key *sk; if (m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) return (1); sk = m->m_pkthdr.pf.statekey; if (sk != NULL) { if (READ_ONCE(sk->sk_inp) != NULL) return (1); } return (-1); } /* * must be called whenever any addressing information such as * address, port, protocol has changed */ void pf_pkt_addr_changed(struct mbuf *m) { pf_mbuf_unlink_state_key(m); pf_mbuf_unlink_inpcb(m); } struct inpcb * pf_inp_lookup(struct mbuf *m) { struct inpcb *inp = NULL; struct pf_state_key *sk = m->m_pkthdr.pf.statekey; if (!pf_state_key_isvalid(sk)) pf_mbuf_unlink_state_key(m); else if (READ_ONCE(sk->sk_inp) != NULL) { mtx_enter(&pf_inp_mtx); inp = in_pcbref(sk->sk_inp); mtx_leave(&pf_inp_mtx); } return (inp); } void pf_inp_link(struct mbuf *m, struct inpcb *inp) { struct pf_state_key *sk = m->m_pkthdr.pf.statekey; if (!pf_state_key_isvalid(sk)) { pf_mbuf_unlink_state_key(m); return; } /* * we don't need to grab PF-lock here. At worst case we link inp to * state, which might be just being marked as deleted by another * thread. */ pf_state_key_link_inpcb(sk, inp); /* The statekey has finished finding the inp, it is no longer needed. */ pf_mbuf_unlink_state_key(m); } void pf_inp_unlink(struct inpcb *inp) { struct pf_state_key *sk; if (READ_ONCE(inp->inp_pf_sk) == NULL) return; mtx_enter(&pf_inp_mtx); sk = inp->inp_pf_sk; if (sk == NULL) { mtx_leave(&pf_inp_mtx); return; } KASSERT(sk->sk_inp == inp); sk->sk_inp = NULL; inp->inp_pf_sk = NULL; mtx_leave(&pf_inp_mtx); pf_state_key_unref(sk); in_pcbunref(inp); } void pf_state_key_link_reverse(struct pf_state_key *sk, struct pf_state_key *skrev) { struct pf_state_key *old_reverse; old_reverse = atomic_cas_ptr(&sk->sk_reverse, NULL, skrev); if (old_reverse != NULL) KASSERT(old_reverse == skrev); else { pf_state_key_ref(skrev); /* * NOTE: if sk == skrev, then KASSERT() below holds true, we * still want to grab a reference in such case, because * pf_state_key_unlink_reverse() does not check whether keys * are identical or not. */ old_reverse = atomic_cas_ptr(&skrev->sk_reverse, NULL, sk); if (old_reverse != NULL) KASSERT(old_reverse == sk); pf_state_key_ref(sk); } } #if NPFLOG > 0 void pf_log_matches(struct pf_pdesc *pd, struct pf_rule *rm, struct pf_rule *am, struct pf_ruleset *ruleset, struct pf_rule_slist *matchrules) { struct pf_rule_item *ri; /* if this is the log(matches) rule, packet has been logged already */ if (rm->log & PF_LOG_MATCHES) return; SLIST_FOREACH(ri, matchrules, entry) if (ri->r->log & PF_LOG_MATCHES) pflog_packet(pd, PFRES_MATCH, rm, am, ruleset, ri->r); } #endif /* NPFLOG > 0 */ struct pf_state_key * pf_state_key_ref(struct pf_state_key *sk) { if (sk != NULL) PF_REF_TAKE(sk->sk_refcnt); return (sk); } void pf_state_key_unref(struct pf_state_key *sk) { if (PF_REF_RELE(sk->sk_refcnt)) { /* state key must be removed from tree */ KASSERT(!pf_state_key_isvalid(sk)); /* state key must be unlinked from reverse key */ KASSERT(sk->sk_reverse == NULL); /* state key must be unlinked from socket */ KASSERT(sk->sk_inp == NULL); pool_put(&pf_state_key_pl, sk); } } int pf_state_key_isvalid(struct pf_state_key *sk) { return ((sk != NULL) && (sk->sk_removed == 0)); } void pf_mbuf_link_state_key(struct mbuf *m, struct pf_state_key *sk) { KASSERT(m->m_pkthdr.pf.statekey == NULL); m->m_pkthdr.pf.statekey = pf_state_key_ref(sk); } void pf_mbuf_unlink_state_key(struct mbuf *m) { struct pf_state_key *sk = m->m_pkthdr.pf.statekey; if (sk != NULL) { m->m_pkthdr.pf.statekey = NULL; pf_state_key_unref(sk); } } void pf_mbuf_link_inpcb(struct mbuf *m, struct inpcb *inp) { KASSERT(m->m_pkthdr.pf.inp == NULL); m->m_pkthdr.pf.inp = in_pcbref(inp); } void pf_mbuf_unlink_inpcb(struct mbuf *m) { struct inpcb *inp = m->m_pkthdr.pf.inp; if (inp != NULL) { m->m_pkthdr.pf.inp = NULL; in_pcbunref(inp); } } void pf_state_key_link_inpcb(struct pf_state_key *sk, struct inpcb *inp) { if (inp == NULL || READ_ONCE(sk->sk_inp) != NULL) return; mtx_enter(&pf_inp_mtx); if (inp->inp_pf_sk != NULL || sk->sk_inp != NULL) { mtx_leave(&pf_inp_mtx); return; } sk->sk_inp = in_pcbref(inp); inp->inp_pf_sk = pf_state_key_ref(sk); mtx_leave(&pf_inp_mtx); } void pf_state_key_unlink_inpcb(struct pf_state_key *sk) { struct inpcb *inp; if (READ_ONCE(sk->sk_inp) == NULL) return; mtx_enter(&pf_inp_mtx); inp = sk->sk_inp; if (inp == NULL) { mtx_leave(&pf_inp_mtx); return; } KASSERT(inp->inp_pf_sk == sk); sk->sk_inp = NULL; inp->inp_pf_sk = NULL; mtx_leave(&pf_inp_mtx); pf_state_key_unref(sk); in_pcbunref(inp); } void pf_state_key_unlink_reverse(struct pf_state_key *sk) { struct pf_state_key *skrev = sk->sk_reverse; /* Note that sk and skrev may be equal, then we unref twice. */ if (skrev != NULL) { KASSERT(skrev->sk_reverse == sk); sk->sk_reverse = NULL; skrev->sk_reverse = NULL; pf_state_key_unref(skrev); pf_state_key_unref(sk); } } struct pf_state * pf_state_ref(struct pf_state *st) { if (st != NULL) PF_REF_TAKE(st->refcnt); return (st); } void pf_state_unref(struct pf_state *st) { if ((st != NULL) && PF_REF_RELE(st->refcnt)) { /* never inserted or removed */ #if NPFSYNC > 0 KASSERT((TAILQ_NEXT(st, sync_list) == NULL) || ((TAILQ_NEXT(st, sync_list) == _Q_INVALID) && (st->sync_state >= PFSYNC_S_NONE))); #endif /* NPFSYNC */ KASSERT((TAILQ_NEXT(st, entry_list) == NULL) || (TAILQ_NEXT(st, entry_list) == _Q_INVALID)); pf_state_key_unref(st->key[PF_SK_WIRE]); pf_state_key_unref(st->key[PF_SK_STACK]); pool_put(&pf_state_pl, st); } } int pf_delay_pkt(struct mbuf *m, u_int ifidx) { struct pf_pktdelay *pdy; if ((pdy = pool_get(&pf_pktdelay_pl, PR_NOWAIT)) == NULL) { m_freem(m); return (ENOBUFS); } pdy->ifidx = ifidx; pdy->m = m; timeout_set(&pdy->to, pf_pktenqueue_delayed, pdy); timeout_add_msec(&pdy->to, m->m_pkthdr.pf.delay); m->m_pkthdr.pf.delay = 0; return (0); } void pf_pktenqueue_delayed(void *arg) { struct pf_pktdelay *pdy = arg; struct ifnet *ifp; ifp = if_get(pdy->ifidx); if (ifp != NULL) { if_enqueue(ifp, pdy->m); if_put(ifp); } else m_freem(pdy->m); pool_put(&pf_pktdelay_pl, pdy); }