/* $OpenBSD: pf.c,v 1.973 2016/05/28 12:04:33 sthen Exp $ */ /* * Copyright (c) 2001 Daniel Hartmeier * Copyright (c) 2002 - 2013 Henning Brauer <henning@openbsd.org> * 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 <sys/param.h> #include <sys/systm.h> #include <sys/mbuf.h> #include <sys/filio.h> #include <sys/socket.h> #include <sys/socketvar.h> #include <sys/kernel.h> #include <sys/time.h> #include <sys/pool.h> #include <sys/proc.h> #include <sys/rwlock.h> #include <sys/syslog.h> #include <crypto/sha2.h> #include <net/if.h> #include <net/if_var.h> #include <net/if_types.h> #include <net/route.h> #include <netinet/in.h> #include <netinet/ip.h> #include <netinet/ip_var.h> #include <netinet/tcp.h> #include <netinet/tcp_seq.h> #include <netinet/udp.h> #include <netinet/ip_icmp.h> #include <netinet/in_pcb.h> #include <netinet/tcp_timer.h> #include <netinet/tcp_var.h> #include <netinet/tcp_fsm.h> #include <netinet/udp_var.h> #include <netinet/icmp_var.h> #include <netinet/ip_divert.h> #include <net/pfvar.h> #if NPFLOG > 0 #include <net/if_pflog.h> #endif /* NPFLOG > 0 */ #if NPFLOW > 0 #include <net/if_pflow.h> #endif /* NPFLOW > 0 */ #if NPFSYNC > 0 #include <net/if_pfsync.h> #endif /* NPFSYNC > 0 */ #ifdef INET6 #include <netinet6/in6_var.h> #include <netinet/ip6.h> #include <netinet6/ip6_var.h> #include <netinet/icmp6.h> #include <netinet6/nd6.h> #include <netinet6/ip6_divert.h> #endif /* INET6 */ #ifdef DDB #include <machine/db_machdep.h> #include <ddb/db_interface.h> #endif /* * 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; SHA2_CTX pf_tcp_secret_ctx; u_char pf_tcp_secret[16]; int pf_tcp_secret_init; int pf_tcp_iss_off; struct pf_anchor_stackframe { struct pf_ruleset *rs; struct pf_rule *r; struct pf_anchor_node *parent; struct pf_anchor *child; } pf_anchor_stack[64]; /* * Cannot fold into pf_pdesc directly, unknown storage size outside pf.c. * Keep in sync with union pf_headers in pflog_bpfcopy() in if_pflog.c. */ union pf_headers { struct tcphdr tcp; struct udphdr udp; struct icmp icmp; #ifdef INET6 struct icmp6_hdr icmp6; struct mld_hdr mld; struct nd_neighbor_solicit nd_ns; #endif /* INET6 */ }; 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; void pf_init_threshold(struct pf_threshold *, u_int32_t, u_int32_t); void pf_add_threshold(struct pf_threshold *); int pf_check_threshold(struct pf_threshold *); void pf_change_ap(struct pf_pdesc *, struct pf_addr *, u_int16_t *, struct pf_addr *, u_int16_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 *); void pf_change_icmp(struct pf_pdesc *, struct pf_addr *, u_int16_t *, struct pf_addr *, struct pf_addr *, 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_icmp_af(int, void *); void pf_send_tcp(const struct pf_rule *, sa_family_t, const struct pf_addr *, const struct pf_addr *, u_int16_t, u_int16_t, u_int32_t, u_int32_t, u_int8_t, u_int16_t, u_int16_t, u_int8_t, int, u_int16_t, u_int); void pf_send_icmp(struct mbuf *, u_int8_t, u_int8_t, sa_family_t, struct pf_rule *, u_int); void pf_detach_state(struct pf_state *); void pf_state_key_detach(struct pf_state *, int); u_int32_t pf_tcp_iss(struct pf_pdesc *); void pf_rule_to_actions(struct pf_rule *, struct pf_rule_actions *); int pf_test_rule(struct pf_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_peer *, struct pf_state_peer *, struct pf_state **, u_short *, int *); int pf_tcp_track_sloppy(struct pf_pdesc *, struct pf_state_peer *, struct pf_state_peer *, 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_int8_t pf_get_wscale(struct pf_pdesc *); u_int16_t pf_get_mss(struct pf_pdesc *); 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_divert *pf_get_divert(struct mbuf *); 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); struct pf_state *pf_find_state(struct pfi_kif *, struct pf_state_key_cmp *, u_int, struct mbuf *); int pf_src_connlimit(struct pf_state **); int pf_match_rcvif(struct mbuf *, struct pf_rule *); void pf_step_into_anchor(int *, struct pf_ruleset **, struct pf_rule **, struct pf_rule **); int pf_step_out_of_anchor(int *, struct pf_ruleset **, struct pf_rule **, struct pf_rule **, int *); void pf_counters_inc(int, struct pf_pdesc *, struct pf_state *, struct pf_rule *, struct pf_rule *); void pf_state_key_link(struct pf_state_key *, struct pf_state_key *); void pf_inpcb_unlink_state_key(struct inpcb *); void pf_state_key_unlink_reverse(struct pf_state_key *); #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 } }; #define STATE_LOOKUP(i, k, d, s, m) \ do { \ s = pf_find_state(i, k, d, m); \ if (s == NULL || (s)->timeout == PFTM_PURGE) \ return (PF_DROP); \ if (d == PF_OUT && \ (((s)->rule.ptr->rt == PF_ROUTETO && \ (s)->rule.ptr->direction == PF_OUT) || \ ((s)->rule.ptr->rt == PF_REPLYTO && \ (s)->rule.ptr->direction == PF_IN)) && \ (s)->rt_kif != NULL && \ (s)->rt_kif != i) \ return (PF_PASS); \ } while (0) #define BOUND_IFACE(r, k) \ ((r)->rule_flag & PFRULE_IFBOUND) ? (k) : pfi_all #define STATE_INC_COUNTERS(s) \ do { \ struct pf_rule_item *mrm; \ s->rule.ptr->states_cur++; \ s->rule.ptr->states_tot++; \ if (s->anchor.ptr != NULL) { \ s->anchor.ptr->states_cur++; \ s->anchor.ptr->states_tot++; \ } \ SLIST_FOREACH(mrm, &s->match_rules, entry) \ mrm->r->states_cur++; \ } while (0) static __inline int pf_src_compare(struct pf_src_node *, struct pf_src_node *); static __inline int pf_state_compare_key(struct pf_state_key *, struct pf_state_key *); static __inline int pf_state_compare_id(struct pf_state *, struct pf_state *); struct pf_src_tree tree_src_tracking; struct pf_state_tree_id tree_id; struct pf_state_queue state_list; RB_GENERATE(pf_src_tree, pf_src_node, entry, pf_src_compare); RB_GENERATE(pf_state_tree, pf_state_key, entry, pf_state_compare_key); RB_GENERATE(pf_state_tree_id, pf_state, entry_id, pf_state_compare_id); __inline int pf_addr_compare(struct pf_addr *a, 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); } 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 = time_uptime; } void pf_add_threshold(struct pf_threshold *threshold) { u_int32_t t = time_uptime, diff = t - threshold->last; if (diff >= threshold->seconds) threshold->count = 0; else threshold->count -= threshold->count * diff / threshold->seconds; threshold->count += PF_THRESHOLD_MULT; threshold->last = t; } int pf_check_threshold(struct pf_threshold *threshold) { return (threshold->count > threshold->limit); } int pf_src_connlimit(struct pf_state **state) { int bad = 0; struct pf_src_node *sn; if ((sn = pf_get_src_node((*state), PF_SN_NONE)) == NULL) return (0); sn->conn++; (*state)->src.tcp_est = 1; pf_add_threshold(&sn->conn_rate); if ((*state)->rule.ptr->max_src_conn && (*state)->rule.ptr->max_src_conn < sn->conn) { pf_status.lcounters[LCNT_SRCCONN]++; bad++; } if ((*state)->rule.ptr->max_src_conn_rate.limit && pf_check_threshold(&sn->conn_rate)) { pf_status.lcounters[LCNT_SRCCONNRATE]++; bad++; } if (!bad) return (0); if ((*state)->rule.ptr->overload_tbl) { struct pfr_addr p; u_int32_t killed = 0; pf_status.lcounters[LCNT_OVERLOAD_TABLE]++; if (pf_status.debug >= LOG_NOTICE) { log(LOG_NOTICE, "pf: pf_src_connlimit: blocking address "); pf_print_host(&sn->addr, 0, (*state)->key[PF_SK_WIRE]->af); } bzero(&p, sizeof(p)); p.pfra_af = (*state)->key[PF_SK_WIRE]->af; switch ((*state)->key[PF_SK_WIRE]->af) { 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((*state)->rule.ptr->overload_tbl, &p, time_second); /* kill existing states if that's required. */ if ((*state)->rule.ptr->flush) { struct pf_state_key *sk; struct pf_state *st; pf_status.lcounters[LCNT_OVERLOAD_FLUSH]++; RB_FOREACH(st, pf_state_tree_id, &tree_id) { sk = st->key[PF_SK_WIRE]; /* * Kill states from this source. (Only those * from the same rule if PF_FLUSH_GLOBAL is not * set) */ if (sk->af == (*state)->key[PF_SK_WIRE]->af && (((*state)->direction == PF_OUT && PF_AEQ(&sn->addr, &sk->addr[1], sk->af)) || ((*state)->direction == PF_IN && PF_AEQ(&sn->addr, &sk->addr[0], sk->af))) && ((*state)->rule.ptr->flush & PF_FLUSH_GLOBAL || (*state)->rule.ptr == st->rule.ptr)) { st->timeout = PFTM_PURGE; st->src.state = st->dst.state = TCPS_CLOSED; killed++; } } if (pf_status.debug >= LOG_NOTICE) addlog(", %u states killed", killed); } if (pf_status.debug >= LOG_NOTICE) addlog("\n"); } /* kill this state */ (*state)->timeout = PFTM_PURGE; (*state)->src.state = (*state)->dst.state = TCPS_CLOSED; return (1); } int pf_insert_src_node(struct pf_src_node **sn, struct pf_rule *rule, enum pf_sn_types type, sa_family_t af, struct pf_addr *src, struct pf_addr *raddr) { struct pf_src_node k; if (*sn == NULL) { k.af = af; k.type = type; PF_ACPY(&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_ACPY(&(*sn)->addr, src, af); if (raddr) PF_ACPY(&(*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 = time_uptime; (*sn)->rule.ptr->src_nodes++; pf_status.scounters[SCNT_SRC_NODE_INSERT]++; pf_status.src_nodes++; } else { if (rule->max_src_states && (*sn)->states >= rule->max_src_states) { pf_status.lcounters[LCNT_SRCSTATES]++; return (-1); } } return (0); } void pf_remove_src_node(struct pf_src_node *sn) { if (sn->states > 0 || sn->expire > time_uptime) 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--; pool_put(&pf_src_tree_pl, sn); } struct pf_src_node * pf_get_src_node(struct pf_state *s, enum pf_sn_types type) { struct pf_sn_item *sni; SLIST_FOREACH(sni, &s->src_nodes, next) if (sni->sn->type == type) return (sni->sn); return (NULL); } void pf_state_rm_src_node(struct pf_state *s, struct pf_src_node *sn) { struct pf_sn_item *sni, *snin, *snip = NULL; for (sni = SLIST_FIRST(&s->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(&s->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(struct pf_state_key *a, struct pf_state_key *b) { int diff; if ((diff = a->proto - b->proto) != 0) return (diff); if ((diff = a->af - b->af) != 0) return (diff); 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(struct pf_state *a, struct pf_state *b) { if (a->id > b->id) return (1); if (a->id < b->id) return (-1); if (a->creatorid > b->creatorid) return (1); if (a->creatorid < b->creatorid) return (-1); return (0); } int pf_state_key_attach(struct pf_state_key *sk, struct pf_state *s, int idx) { struct pf_state_item *si; struct pf_state_key *cur; struct pf_state *olds = NULL; KASSERT(s->key[idx] == NULL); if ((cur = RB_INSERT(pf_state_tree, &pf_statetbl, sk)) != NULL) { /* key exists. check for same kif, if none, add to key */ TAILQ_FOREACH(si, &cur->states, entry) if (si->s->kif == s->kif && ((si->s->key[PF_SK_WIRE]->af == sk->af && si->s->direction == s->direction) || (si->s->key[PF_SK_WIRE]->af != si->s->key[PF_SK_STACK]->af && sk->af == si->s->key[PF_SK_STACK]->af && si->s->direction != s->direction))) { if (sk->proto == IPPROTO_TCP && si->s->src.state >= TCPS_FIN_WAIT_2 && si->s->dst.state >= TCPS_FIN_WAIT_2) { si->s->src.state = si->s->dst.state = TCPS_CLOSED; /* remove late or sks can go away */ olds = si->s; } else { if (pf_status.debug >= LOG_NOTICE) { log(LOG_NOTICE, "pf: %s key attach " "failed on %s: ", (idx == PF_SK_WIRE) ? "wire" : "stack", s->kif->pfik_name); pf_print_state_parts(s, (idx == PF_SK_WIRE) ? sk : NULL, (idx == PF_SK_STACK) ? sk : NULL); addlog(", existing: "); pf_print_state_parts(si->s, (idx == PF_SK_WIRE) ? sk : NULL, (idx == PF_SK_STACK) ? sk : NULL); addlog("\n"); } pool_put(&pf_state_key_pl, sk); return (-1); /* collision! */ } } pool_put(&pf_state_key_pl, sk); s->key[idx] = cur; } else s->key[idx] = sk; if ((si = pool_get(&pf_state_item_pl, PR_NOWAIT)) == NULL) { pf_state_key_detach(s, idx); return (-1); } si->s = s; /* list is sorted, if-bound states before floating */ if (s->kif == pfi_all) TAILQ_INSERT_TAIL(&s->key[idx]->states, si, entry); else TAILQ_INSERT_HEAD(&s->key[idx]->states, si, entry); if (olds) pf_remove_state(olds); return (0); } void pf_detach_state(struct pf_state *s) { if (s->key[PF_SK_WIRE] == s->key[PF_SK_STACK]) s->key[PF_SK_WIRE] = NULL; if (s->key[PF_SK_STACK] != NULL) pf_state_key_detach(s, PF_SK_STACK); if (s->key[PF_SK_WIRE] != NULL) pf_state_key_detach(s, PF_SK_WIRE); } void pf_state_key_detach(struct pf_state *s, int idx) { struct pf_state_item *si; struct pf_state_key *sk; if (s->key[idx] == NULL) return; si = TAILQ_FIRST(&s->key[idx]->states); while (si && si->s != s) si = TAILQ_NEXT(si, entry); if (si) { TAILQ_REMOVE(&s->key[idx]->states, si, entry); pool_put(&pf_state_item_pl, si); } sk = s->key[idx]; s->key[idx] = NULL; if (TAILQ_EMPTY(&sk->states)) { RB_REMOVE(pf_state_tree, &pf_statetbl, sk); sk->removed = 1; pf_state_key_unlink_reverse(sk); pf_inpcb_unlink_state_key(sk->inp); pf_state_key_unref(sk); } } struct pf_state_key * pf_alloc_state_key(int pool_flags) { struct pf_state_key *sk; if ((sk = pool_get(&pf_state_key_pl, pool_flags)) == NULL) return (NULL); TAILQ_INIT(&sk->states); return (sk); } 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 nd_neighbor_solicit *nd; 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); nd = (void *)pd->hdr.icmp6; target = (struct pf_addr *)&nd->nd_ns_target; daddr = target; break; case ND_NEIGHBOR_ADVERT: if (multi) return (-1); nd = (void *)pd->hdr.icmp6; target = (struct pf_addr *)&nd->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_ACPY(&key->addr[sidx], saddr, af); if (daddr) PF_ACPY(&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; PF_REF_INIT(sk1->refcnt); sk1->removed = 0; 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) { pool_put(&pf_state_key_pl, 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; PF_REF_INIT(sk2->refcnt); sk2->removed = 0; } else sk2 = 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); } int pf_state_insert(struct pfi_kif *kif, struct pf_state_key **skw, struct pf_state_key **sks, struct pf_state *s) { splsoftassert(IPL_SOFTNET); s->kif = kif; if (*skw == *sks) { if (pf_state_key_attach(*skw, s, PF_SK_WIRE)) return (-1); *skw = *sks = s->key[PF_SK_WIRE]; s->key[PF_SK_STACK] = s->key[PF_SK_WIRE]; } else { if (pf_state_key_attach(*skw, s, PF_SK_WIRE)) { pool_put(&pf_state_key_pl, *sks); return (-1); } *skw = s->key[PF_SK_WIRE]; if (pf_state_key_attach(*sks, s, PF_SK_STACK)) { pf_state_key_detach(s, PF_SK_WIRE); return (-1); } *sks = s->key[PF_SK_STACK]; } if (s->id == 0 && s->creatorid == 0) { s->id = htobe64(pf_status.stateid++); s->creatorid = pf_status.hostid; } if (RB_INSERT(pf_state_tree_id, &tree_id, s) != NULL) { if (pf_status.debug >= LOG_NOTICE) { log(LOG_NOTICE, "pf: state insert failed: " "id: %016llx creatorid: %08x", betoh64(s->id), ntohl(s->creatorid)); addlog("\n"); } pf_detach_state(s); return (-1); } TAILQ_INSERT_TAIL(&state_list, s, entry_list); pf_status.fcounters[FCNT_STATE_INSERT]++; pf_status.states++; pfi_kif_ref(kif, PFI_KIF_REF_STATE); #if NPFSYNC > 0 pfsync_insert_state(s); #endif /* NPFSYNC > 0 */ return (0); } struct pf_state * pf_find_state_byid(struct pf_state_cmp *key) { pf_status.fcounters[FCNT_STATE_SEARCH]++; return (RB_FIND(pf_state_tree_id, &tree_id, (struct pf_state *)key)); } 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); } } struct pf_state * pf_find_state(struct pfi_kif *kif, struct pf_state_key_cmp *key, u_int dir, struct mbuf *m) { struct pf_state_key *sk, *pkt_sk, *inp_sk; struct pf_state_item *si; pf_status.fcounters[FCNT_STATE_SEARCH]++; if (pf_status.debug >= LOG_DEBUG) { log(LOG_DEBUG, "pf: key search, if=%s: ", kif->pfik_name); pf_print_state_parts(NULL, (struct pf_state_key *)key, NULL); addlog("\n"); } inp_sk = NULL; pkt_sk = NULL; sk = NULL; if (dir == PF_OUT) { /* first if block deals with outbound forwarded packet */ pkt_sk = m->m_pkthdr.pf.statekey; if (pf_state_key_isvalid(pkt_sk) && pf_state_key_isvalid(pkt_sk->reverse)) { sk = pkt_sk->reverse; } else { pf_pkt_unlink_state_key(m); pkt_sk = NULL; } if (pkt_sk == NULL) { /* here we deal with local outbound packet */ if (m->m_pkthdr.pf.inp != NULL) { inp_sk = m->m_pkthdr.pf.inp->inp_pf_sk; if (pf_state_key_isvalid(inp_sk)) sk = inp_sk; else pf_inpcb_unlink_state_key( m->m_pkthdr.pf.inp); } } } if (sk == NULL) { if ((sk = RB_FIND(pf_state_tree, &pf_statetbl, (struct pf_state_key *)key)) == NULL) return (NULL); if (dir == PF_OUT && pkt_sk && pf_compare_state_keys(pkt_sk, sk, kif, dir) == 0) pf_state_key_link(sk, pkt_sk); else if (dir == PF_OUT) pf_inp_link(m, m->m_pkthdr.pf.inp); } /* remove firewall data from outbound packet */ if (dir == PF_OUT) pf_pkt_addr_changed(m); /* list is sorted, if-bound states before floating ones */ TAILQ_FOREACH(si, &sk->states, entry) if ((si->s->kif == pfi_all || si->s->kif == kif) && ((si->s->key[PF_SK_WIRE]->af == si->s->key[PF_SK_STACK]->af && sk == (dir == PF_IN ? si->s->key[PF_SK_WIRE] : si->s->key[PF_SK_STACK])) || (si->s->key[PF_SK_WIRE]->af != si->s->key[PF_SK_STACK]->af && dir == PF_IN && (sk == si->s->key[PF_SK_STACK] || sk == si->s->key[PF_SK_WIRE])))) return (si->s); return (NULL); } struct pf_state * pf_find_state_all(struct pf_state_key_cmp *key, u_int dir, int *more) { struct pf_state_key *sk; struct pf_state_item *si, *ret = NULL; pf_status.fcounters[FCNT_STATE_SEARCH]++; sk = RB_FIND(pf_state_tree, &pf_statetbl, (struct pf_state_key *)key); if (sk != NULL) { TAILQ_FOREACH(si, &sk->states, entry) if (dir == PF_INOUT || (sk == (dir == PF_IN ? si->s->key[PF_SK_WIRE] : si->s->key[PF_SK_STACK]))) { if (more == NULL) return (si->s); if (ret) (*more)++; else ret = si; } } return (ret ? ret->s : NULL); } void pf_state_export(struct pfsync_state *sp, struct pf_state *st) { int32_t expire; bzero(sp, 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)); memcpy(&sp->rt_addr, &st->rt_addr, sizeof(sp->rt_addr)); sp->creation = htonl(time_uptime - st->creation); expire = pf_state_expires(st); if (expire <= time_uptime) sp->expire = htonl(0); else sp->expire = htonl(expire - time_uptime); 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 (!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]; } /* END state table stuff */ void pf_purge_thread(void *v) { int nloops = 0, s; for (;;) { tsleep(pf_purge_thread, PWAIT, "pftm", 1 * hz); s = splsoftnet(); /* process a fraction of the state table every second */ pf_purge_expired_states(1 + (pf_status.states / pf_default_rule.timeout[PFTM_INTERVAL])); /* purge other expired types every PFTM_INTERVAL seconds */ if (++nloops >= pf_default_rule.timeout[PFTM_INTERVAL]) { pf_purge_expired_fragments(); pf_purge_expired_src_nodes(0); nloops = 0; } splx(s); } } int32_t pf_state_expires(const struct pf_state *state) { int32_t timeout; u_int32_t start; u_int32_t end; u_int32_t states; /* handle all PFTM_* > PFTM_MAX here */ if (state->timeout == PFTM_PURGE) return (0); KASSERT(state->timeout != PFTM_UNLINKED); KASSERT(state->timeout < PFTM_MAX); timeout = state->rule.ptr->timeout[state->timeout]; if (!timeout) timeout = pf_default_rule.timeout[state->timeout]; start = state->rule.ptr->timeout[PFTM_ADAPTIVE_START]; if (start) { end = state->rule.ptr->timeout[PFTM_ADAPTIVE_END]; states = state->rule.ptr->states_cur; } else { start = pf_default_rule.timeout[PFTM_ADAPTIVE_START]; end = pf_default_rule.timeout[PFTM_ADAPTIVE_END]; states = pf_status.states; } if (end && states > start && start < end) { if (states >= end) return (0); timeout = timeout * (end - states) / (end - start); } return (state->expire + timeout); } void pf_purge_expired_src_nodes(int waslocked) { struct pf_src_node *cur, *next; int locked = waslocked; for (cur = RB_MIN(pf_src_tree, &tree_src_tracking); cur; cur = next) { next = RB_NEXT(pf_src_tree, &tree_src_tracking, cur); if (cur->states == 0 && cur->expire <= time_uptime) { if (! locked) { rw_enter_write(&pf_consistency_lock); next = RB_NEXT(pf_src_tree, &tree_src_tracking, cur); locked = 1; } pf_remove_src_node(cur); } } if (locked && !waslocked) rw_exit_write(&pf_consistency_lock); } void pf_src_tree_remove_state(struct pf_state *s) { u_int32_t timeout; struct pf_sn_item *sni; while ((sni = SLIST_FIRST(&s->src_nodes)) != NULL) { SLIST_REMOVE_HEAD(&s->src_nodes, next); if (s->src.tcp_est) --sni->sn->conn; if (--sni->sn->states == 0) { timeout = s->rule.ptr->timeout[PFTM_SRC_NODE]; if (!timeout) timeout = pf_default_rule.timeout[PFTM_SRC_NODE]; sni->sn->expire = time_uptime + timeout; } pool_put(&pf_sn_item_pl, sni); } } /* callers should be at splsoftnet */ void pf_remove_state(struct pf_state *cur) { splsoftassert(IPL_SOFTNET); /* handle load balancing related tasks */ pf_postprocess_addr(cur); if (cur->src.state == PF_TCPS_PROXY_DST) { pf_send_tcp(cur->rule.ptr, cur->key[PF_SK_WIRE]->af, &cur->key[PF_SK_WIRE]->addr[1], &cur->key[PF_SK_WIRE]->addr[0], cur->key[PF_SK_WIRE]->port[1], cur->key[PF_SK_WIRE]->port[0], cur->src.seqhi, cur->src.seqlo + 1, TH_RST|TH_ACK, 0, 0, 0, 1, cur->tag, cur->key[PF_SK_WIRE]->rdomain); } RB_REMOVE(pf_state_tree_id, &tree_id, cur); #if NPFLOW > 0 if (cur->state_flags & PFSTATE_PFLOW) export_pflow(cur); #endif /* NPFLOW > 0 */ #if NPFSYNC > 0 pfsync_delete_state(cur); #endif /* NPFSYNC > 0 */ cur->timeout = PFTM_UNLINKED; pf_src_tree_remove_state(cur); pf_detach_state(cur); } void pf_remove_divert_state(struct pf_state_key *sk) { struct pf_state_item *si; TAILQ_FOREACH(si, &sk->states, entry) { if (sk == si->s->key[PF_SK_STACK] && si->s->rule.ptr && si->s->rule.ptr->divert.port) { pf_remove_state(si->s); break; } } } /* callers should be at splsoftnet and hold the * write_lock on pf_consistency_lock */ void pf_free_state(struct pf_state *cur) { struct pf_rule_item *ri; splsoftassert(IPL_SOFTNET); #if NPFSYNC > 0 if (pfsync_state_in_use(cur)) return; #endif /* NPFSYNC > 0 */ KASSERT(cur->timeout == PFTM_UNLINKED); if (--cur->rule.ptr->states_cur == 0 && cur->rule.ptr->src_nodes == 0) pf_rm_rule(NULL, cur->rule.ptr); if (cur->anchor.ptr != NULL) if (--cur->anchor.ptr->states_cur == 0) pf_rm_rule(NULL, cur->anchor.ptr); while ((ri = SLIST_FIRST(&cur->match_rules))) { SLIST_REMOVE_HEAD(&cur->match_rules, entry); if (--ri->r->states_cur == 0 && ri->r->src_nodes == 0) pf_rm_rule(NULL, ri->r); pool_put(&pf_rule_item_pl, ri); } pf_normalize_tcp_cleanup(cur); pfi_kif_unref(cur->kif, PFI_KIF_REF_STATE); TAILQ_REMOVE(&state_list, cur, entry_list); if (cur->tag) pf_tag_unref(cur->tag); pool_put(&pf_state_pl, cur); pf_status.fcounters[FCNT_STATE_REMOVALS]++; pf_status.states--; } void pf_purge_expired_states(u_int32_t maxcheck) { static struct pf_state *cur = NULL; struct pf_state *next; int locked = 0; while (maxcheck--) { /* wrap to start of list when we hit the end */ if (cur == NULL) { cur = TAILQ_FIRST(&state_list); if (cur == NULL) break; /* list empty */ } /* get next state, as cur may get deleted */ next = TAILQ_NEXT(cur, entry_list); if (cur->timeout == PFTM_UNLINKED) { /* free removed state */ if (! locked) { rw_enter_write(&pf_consistency_lock); locked = 1; } pf_free_state(cur); } else if (pf_state_expires(cur) <= time_uptime) { /* remove and free expired state */ pf_remove_state(cur); if (! locked) { rw_enter_write(&pf_consistency_lock); locked = 1; } pf_free_state(cur); } cur = next; } if (locked) rw_exit_write(&pf_consistency_lock); } int pf_tbladdr_setup(struct pf_ruleset *rs, struct pf_addr_wrap *aw) { if (aw->type != PF_ADDR_TABLE) return (0); if ((aw->p.tbl = pfr_attach_table(rs, aw->v.tblname, 1)) == NULL) return (1); return (0); } void pf_tbladdr_remove(struct pf_addr_wrap *aw) { if (aw->type != PF_ADDR_TABLE || aw->p.tbl == NULL) return; pfr_detach_table(aw->p.tbl); aw->p.tbl = NULL; } void pf_tbladdr_copyout(struct pf_addr_wrap *aw) { struct pfr_ktable *kt = aw->p.tbl; if (aw->type != PF_ADDR_TABLE || kt == NULL) return; if (!(kt->pfrkt_flags & PFR_TFLAG_ACTIVE) && kt->pfrkt_root != NULL) kt = kt->pfrkt_root; aw->p.tbl = NULL; aw->p.tblcnt = (kt->pfrkt_flags & PFR_TFLAG_ACTIVE) ? kt->pfrkt_cnt : -1; } void pf_print_host(struct pf_addr *addr, u_int16_t p, sa_family_t af) { switch (af) { 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 *s) { pf_print_state_parts(s, NULL, NULL); } void pf_print_state_parts(struct pf_state *s, struct pf_state_key *skwp, struct pf_state_key *sksp) { struct pf_state_key *skw, *sks; u_int8_t proto, dir; /* Do our best to fill these, but they're skipped if NULL */ skw = skwp ? skwp : (s ? s->key[PF_SK_WIRE] : NULL); sks = sksp ? sksp : (s ? s->key[PF_SK_STACK] : NULL); proto = skw ? skw->proto : (sks ? sks->proto : 0); dir = s ? s->direction : 0; switch (proto) { case IPPROTO_IPV4: 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 (s) { if (proto == IPPROTO_TCP) { addlog(" [lo=%u high=%u win=%u modulator=%u", s->src.seqlo, s->src.seqhi, s->src.max_win, s->src.seqdiff); if (s->src.wscale && s->dst.wscale) addlog(" wscale=%u", s->src.wscale & PF_WSCALE_MASK); addlog("]"); addlog(" [lo=%u high=%u win=%u modulator=%u", s->dst.seqlo, s->dst.seqhi, s->dst.max_win, s->dst.seqdiff); if (s->src.wscale && s->dst.wscale) addlog(" wscale=%u", s->dst.wscale & PF_WSCALE_MASK); addlog("]"); } addlog(" %u:%u", s->src.state, s->dst.state); if (s->rule.ptr) addlog(" @%d", s->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); } } void pf_change_ap(struct pf_pdesc *pd, struct pf_addr *a, u_int16_t *p, struct pf_addr *an, u_int16_t pn) { if (pd->csum_status == PF_CSUM_UNKNOWN) pf_check_proto_cksum(pd, pd->off, pd->tot_len - pd->off, pd->proto, pd->af); if (pd->af == pd->naf) PF_ACPY(a, an, pd->naf); if (p != NULL) *p = pn; } /* Changes a u_int32_t. Uses a void * so there are no align restrictions */ void pf_change_a(struct pf_pdesc *pd, void *a, u_int32_t an) { if (pd->csum_status == PF_CSUM_UNKNOWN) pf_check_proto_cksum(pd, pd->off, pd->tot_len - pd->off, pd->proto, pd->af); memcpy(a, &an, sizeof(u_int32_t)); } 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: *icmp_dir = PF_IN; /* FALLTHROUGH */ case MLD_LISTENER_REPORT: { struct mld_hdr *mld = (void *)pd->hdr.icmp6; u_int32_t h; *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 = (void *)pd->hdr.icmp6; 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); 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_change_icmp(struct pf_pdesc *pd, struct pf_addr *ia, u_int16_t *ip, struct pf_addr *oa, struct pf_addr *na, u_int16_t np) { if (pd->csum_status == PF_CSUM_UNKNOWN) pf_check_proto_cksum(pd, pd->off, pd->tot_len - pd->off, pd->proto, pd->af); /* Change inner protocol port */ if (ip != NULL) *ip = np; /* Change inner ip address */ PF_ACPY(ia, na, pd->af); /* Outer ip address, fix outer icmpv6 checksum, if necessary. */ if (oa) PF_ACPY(oa, na, pd->af); } #if INET6 int pf_translate_af(struct pf_pdesc *pd) { struct mbuf *mp; struct ip *ip4; struct ip6_hdr *ip6; struct icmp6_hdr *icmp; int hlen; if (pd->csum_status == PF_CSUM_UNKNOWN) pf_check_proto_cksum(pd, pd->off, pd->tot_len - pd->off, pd->proto, pd->af); hlen = pd->naf == AF_INET ? sizeof(*ip4) : sizeof(*ip6); /* trim the old header */ m_adj(pd->m, pd->off); /* prepend a new one */ if ((M_PREPEND(pd->m, hlen, M_DONTWAIT)) == NULL) { pd->m = NULL; return (-1); } switch (pd->naf) { case AF_INET: ip4 = mtod(pd->m, struct ip *); bzero(ip4, hlen); ip4->ip_v = IPVERSION; ip4->ip_hl = hlen >> 2; ip4->ip_tos = pd->tos; ip4->ip_len = htons(hlen + (pd->tot_len - pd->off)); 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 *); bzero(ip6, hlen); ip6->ip6_vfc = IPV6_VERSION; ip6->ip6_flow |= htonl((u_int32_t)pd->tos << 20); ip6->ip6_plen = htons(pd->tot_len - pd->off); 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: return (-1); } /* recalculate icmp/icmp6 checksums */ if (pd->proto == IPPROTO_ICMP || pd->proto == IPPROTO_ICMPV6) { int off; if ((mp = m_pulldown(pd->m, hlen, sizeof(*icmp), &off)) == NULL) { pd->m = NULL; return (-1); } icmp = (struct icmp6_hdr *)(mp->m_data + off); icmp->icmp6_cksum = 0; icmp->icmp6_cksum = pd->naf == AF_INET ? in4_cksum(pd->m, 0, hlen, ntohs(ip4->ip_len) - hlen) : in6_cksum(pd->m, IPPROTO_ICMPV6, hlen, ntohs(ip6->ip6_plen)); } return (0); } int pf_change_icmp_af(struct mbuf *m, int off, 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; int hlen, olen, mlen; if (pd->csum_status == PF_CSUM_UNKNOWN) pf_check_proto_cksum(pd, pd->off, pd->tot_len - pd->off, pd->proto, pd->af); if (af == naf || (af != AF_INET && af != AF_INET6) || (naf != AF_INET && naf != AF_INET6)) return (-1); /* split the mbuf chain on the inner ip/ip6 header boundary */ if ((n = m_split(m, off, M_DONTWAIT)) == NULL) return (-1); /* old header */ olen = pd2->off - off; /* new header */ hlen = naf == AF_INET ? sizeof(*ip4) : sizeof(*ip6); /* trim old header */ m_adj(n, olen); /* prepend a new one */ if ((M_PREPEND(n, hlen, M_DONTWAIT)) == NULL) return (-1); /* translate inner ip/ip6 header */ switch (naf) { case AF_INET: ip4 = mtod(n, struct ip *); bzero(ip4, sizeof(*ip4)); ip4->ip_v = IPVERSION; ip4->ip_hl = sizeof(*ip4) >> 2; ip4->ip_len = htons(sizeof(*ip4) + pd2->tot_len - olen); 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; ip4->ip_sum = in_cksum(n, ip4->ip_hl << 2); break; case AF_INET6: ip6 = mtod(n, struct ip6_hdr *); bzero(ip6, sizeof(*ip6)); ip6->ip6_vfc = IPV6_VERSION; ip6->ip6_plen = htons(pd2->tot_len - olen); 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; } /* adjust payload offset and total packet length */ pd2->off += hlen - olen; pd->tot_len += hlen - olen; /* merge modified inner packet with the original header */ mlen = n->m_pkthdr.len; m_cat(m, n); m->m_pkthdr.len += mlen; return (0); } #define PTR_IP(field) (offsetof(struct ip, field)) #define PTR_IP6(field) (offsetof(struct ip6_hdr, field)) int pf_translate_icmp_af(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); } icmp6->icmp6_type = type; icmp6->icmp6_code = code; /* aligns well with a icmpv4 nextmtu */ icmp6->icmp6_mtu = htonl(mtu); /* icmpv4 pptr is a one most significant byte */ if (ptr >= 0) 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); } icmp4->icmp_type = type; icmp4->icmp_code = code; icmp4->icmp_nextmtu = htons(mtu); if (ptr >= 0) 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 tcphdr *th = pd->hdr.tcp; int hlen = (th->th_off << 2) - sizeof(*th); int thoptlen = hlen; u_int8_t opts[MAX_TCPOPTLEN], *opt = opts; int copyback = 0, i, olen; struct sackblk sack; #define TCPOLEN_SACKLEN (TCPOLEN_SACK + 2) if (hlen < TCPOLEN_SACKLEN || hlen > MAX_TCPOPTLEN || !pf_pull_hdr( pd->m, pd->off + sizeof(*th), opts, hlen, NULL, NULL, pd->af)) return 0; while (hlen >= TCPOLEN_SACKLEN) { olen = opt[1]; switch (*opt) { case TCPOPT_EOL: /* FALLTHROUGH */ case TCPOPT_NOP: opt++; hlen--; break; case TCPOPT_SACK: if (olen > hlen) olen = hlen; if (olen >= TCPOLEN_SACKLEN) { for (i = 2; i + TCPOLEN_SACK <= olen; i += TCPOLEN_SACK) { memcpy(&sack, &opt[i], sizeof(sack)); pf_change_a(pd, &sack.start, htonl(ntohl(sack.start) - dst->seqdiff)); pf_change_a(pd, &sack.end, htonl(ntohl(sack.end) - dst->seqdiff)); memcpy(&opt[i], &sack, sizeof(sack)); } copyback = 1; } /* FALLTHROUGH */ default: if (olen < 2) olen = 2; hlen -= olen; opt += olen; } } if (copyback) m_copyback(pd->m, pd->off + sizeof(*th), thoptlen, opts, M_NOWAIT); return (copyback); } void pf_send_tcp(const struct pf_rule *r, sa_family_t af, const struct pf_addr *saddr, const struct pf_addr *daddr, u_int16_t sport, u_int16_t dport, u_int32_t seq, u_int32_t ack, u_int8_t flags, u_int16_t win, u_int16_t mss, u_int8_t ttl, int tag, u_int16_t rtag, 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; 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; 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; bzero(m->m_data, 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); if (mss) { opt = (char *)(th + 1); opt[0] = TCPOPT_MAXSEG; opt[1] = 4; mss = htons(mss); memcpy((opt + 2), &mss, 2); } switch (af) { case AF_INET: ip_send(m); break; #ifdef INET6 case AF_INET6: ip6_send(m); break; #endif /* INET6 */ } } void pf_send_icmp(struct mbuf *m, u_int8_t type, u_int8_t code, sa_family_t af, struct pf_rule *r, u_int 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, 0); break; #ifdef INET6 case AF_INET6: icmp6_error(m0, type, code, 0); break; #endif /* INET6 */ } } /* * Return 1 if the addresses a and b match (with mask m), otherwise return 0. * If n is 0, they match if they are equal. If n is != 0, they match if they * are different. */ int pf_match_addr(u_int8_t n, struct pf_addr *a, struct pf_addr *m, struct pf_addr *b, sa_family_t af) { int match = 0; switch (af) { case AF_INET: if ((a->addr32[0] & m->addr32[0]) == (b->addr32[0] & m->addr32[0])) match++; 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]))) match++; break; #endif /* INET6 */ } if (match) { if (n) return (0); else return (1); } else { if (n) return (1); else return (0); } } /* * Return 1 if b <= a <= e, otherwise return 0. */ int pf_match_addr_range(struct pf_addr *b, struct pf_addr *e, struct pf_addr *a, sa_family_t af) { switch (af) { 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 == UID_MAX && op != PF_OP_EQ && op != PF_OP_NE) return (0); return (pf_match(op, a1, a2, u)); } int pf_match_gid(u_int8_t op, gid_t a1, gid_t a2, gid_t g) { if (g == GID_MAX && op != PF_OP_EQ && op != PF_OP_NE) return (0); return (pf_match(op, a1, a2, g)); } int pf_match_tag(struct mbuf *m, struct pf_rule *r, int *tag) { if (*tag == -1) *tag = m->m_pkthdr.pf.tag; return ((!r->match_tag_not && r->match_tag == *tag) || (r->match_tag_not && r->match_tag != *tag)); } int pf_match_rcvif(struct mbuf *m, struct pf_rule *r) { struct ifnet *ifp; 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 && ifp->if_carpdev) kif = (struct pfi_kif *)ifp->if_carpdev->if_pf_kif; else #endif /* NCARP */ kif = (struct pfi_kif *)ifp->if_pf_kif; if_put(ifp); if (kif == NULL) { DPFPRINTF(LOG_ERR, "pf_test_via: kif == NULL, @%d via %s", 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_step_into_anchor(int *depth, struct pf_ruleset **rs, struct pf_rule **r, struct pf_rule **a) { struct pf_anchor_stackframe *f; if (*depth >= sizeof(pf_anchor_stack) / sizeof(pf_anchor_stack[0])) { log(LOG_ERR, "pf_step_into_anchor: stack overflow\n"); *r = TAILQ_NEXT(*r, entries); return; } else if (a != NULL) *a = *r; f = pf_anchor_stack + (*depth)++; f->rs = *rs; f->r = *r; if ((*r)->anchor_wildcard) { f->parent = &(*r)->anchor->children; if ((f->child = RB_MIN(pf_anchor_node, f->parent)) == NULL) { *r = NULL; return; } *rs = &f->child->ruleset; } else { f->parent = NULL; f->child = NULL; *rs = &(*r)->anchor->ruleset; } *r = TAILQ_FIRST((*rs)->rules.active.ptr); } int pf_step_out_of_anchor(int *depth, struct pf_ruleset **rs, struct pf_rule **r, struct pf_rule **a, int *match) { struct pf_anchor_stackframe *f; int quick = 0; do { if (*depth <= 0) break; f = pf_anchor_stack + *depth - 1; if (f->parent != NULL && f->child != NULL) { f->child = RB_NEXT(pf_anchor_node, f->parent, f->child); if (f->child != NULL) { *rs = &f->child->ruleset; *r = TAILQ_FIRST((*rs)->rules.active.ptr); if (*r == NULL) continue; else break; } } (*depth)--; if (*depth == 0 && a != NULL) *a = NULL; else if (a != NULL) *a = f->r; *rs = f->rs; if (*match > *depth) { *match = *depth; if (f->r->quick) quick = 1; } *r = TAILQ_NEXT(f->r, entries); } while (*r == NULL); return (quick); } 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 *tb; struct inpcb *inp; if (pd == NULL) return (-1); pd->lookup.uid = UID_MAX; pd->lookup.gid = GID_MAX; pd->lookup.pid = NO_PID; switch (pd->proto) { case IPPROTO_TCP: if (pd->hdr.tcp == NULL) return (-1); sport = pd->hdr.tcp->th_sport; dport = pd->hdr.tcp->th_dport; tb = &tcbtable; break; case IPPROTO_UDP: if (pd->hdr.udp == NULL) return (-1); sport = pd->hdr.udp->uh_sport; dport = pd->hdr.udp->uh_dport; tb = &udbtable; break; default: return (-1); } if (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_pcbhashlookup(tb, saddr->v4, sport, daddr->v4, dport, pd->rdomain); if (inp == NULL) { inp = in_pcblookup_listen(tb, daddr->v4, dport, 0, NULL, pd->rdomain); if (inp == NULL) return (-1); } break; #ifdef INET6 case AF_INET6: inp = in6_pcbhashlookup(tb, &saddr->v6, sport, &daddr->v6, dport, pd->rdomain); if (inp == NULL) { inp = in6_pcblookup_listen(tb, &daddr->v6, dport, 0, 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; return (1); } u_int8_t pf_get_wscale(struct pf_pdesc *pd) { struct tcphdr *th = pd->hdr.tcp; int hlen; u_int8_t hdr[60]; u_int8_t *opt, optlen; u_int8_t wscale = 0; hlen = th->th_off << 2; /* hlen <= sizeof(hdr) */ if (hlen <= sizeof(struct tcphdr)) return (0); if (!pf_pull_hdr(pd->m, pd->off, hdr, hlen, NULL, NULL, pd->af)) return (0); opt = hdr + sizeof(struct tcphdr); hlen -= sizeof(struct tcphdr); while (hlen >= 3) { switch (*opt) { case TCPOPT_EOL: case TCPOPT_NOP: ++opt; --hlen; break; case TCPOPT_WINDOW: wscale = opt[2]; if (wscale > TCP_MAX_WINSHIFT) wscale = TCP_MAX_WINSHIFT; wscale |= PF_WSCALE_FLAG; /* FALLTHROUGH */ default: optlen = opt[1]; if (optlen < 2) optlen = 2; hlen -= optlen; opt += optlen; break; } } return (wscale); } u_int16_t pf_get_mss(struct pf_pdesc *pd) { struct tcphdr *th = pd->hdr.tcp; int hlen; u_int8_t hdr[60]; u_int8_t *opt, optlen; u_int16_t mss = tcp_mssdflt; hlen = th->th_off << 2; /* hlen <= sizeof(hdr) */ if (hlen <= sizeof(struct tcphdr)) return (0); if (!pf_pull_hdr(pd->m, pd->off, hdr, hlen, NULL, NULL, pd->af)) return (0); opt = hdr + sizeof(struct tcphdr); hlen -= sizeof(struct tcphdr); while (hlen >= TCPOLEN_MAXSEG) { switch (*opt) { case TCPOPT_EOL: case TCPOPT_NOP: ++opt; --hlen; break; case TCPOPT_MAXSEG: memcpy(&mss, (opt + 2), 2); mss = ntohs(mss); /* FALLTHROUGH */ default: optlen = opt[1]; if (optlen < 2) optlen = 2; hlen -= optlen; opt += optlen; break; } } return (mss); } u_int16_t pf_calc_mss(struct pf_addr *addr, sa_family_t af, 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 *s, struct pf_addr *saddr, sa_family_t af) { struct pf_rule *r = s->rule.ptr; struct pf_src_node *sns[PF_SN_MAX]; int rv; s->rt_kif = NULL; if (!r->rt) return (0); bzero(sns, sizeof(sns)); switch (af) { case AF_INET: rv = pf_map_addr(AF_INET, r, saddr, &s->rt_addr, NULL, sns, &r->route, PF_SN_ROUTE); break; #ifdef INET6 case AF_INET6: rv = pf_map_addr(AF_INET6, r, saddr, &s->rt_addr, NULL, sns, &r->route, PF_SN_ROUTE); break; #endif /* INET6 */ default: rv = 1; } if (rv == 0) { s->rt_kif = r->route.kif; s->natrule.ptr = r; } 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] + 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]; } } #define PF_TEST_ATTRIB(t, a) \ do { \ if (t) { \ r = a; \ goto nextrule; \ } \ } while (0) 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; struct pf_rule *nr = NULL; struct pf_rule *a = NULL; struct pf_ruleset *arsm = NULL; struct pf_ruleset *aruleset = NULL; struct pf_ruleset *ruleset = NULL; struct pf_rule_slist rules; struct pf_rule_item *ri; struct pf_src_node *sns[PF_SN_MAX]; struct tcphdr *th = pd->hdr.tcp; struct pf_state_key *skw = NULL, *sks = NULL; struct pf_rule_actions act; int rewrite = 0; int tag = -1; int asd = 0; int match = 0; int state_icmp = 0, icmp_dir = 0; u_int16_t virtual_type, virtual_id; u_int8_t icmptype = 0, icmpcode = 0; int action = PF_DROP; bzero(&act, sizeof(act)); bzero(sns, sizeof(sns)); act.rtableid = pd->rdomain; SLIST_INIT(&rules); if (pd->dir == PF_IN && if_congested()) { REASON_SET(reason, PFRES_CONGEST); return (PF_DROP); } switch (pd->virtual_proto) { case IPPROTO_ICMP: icmptype = pd->hdr.icmp->icmp_type; icmpcode = pd->hdr.icmp->icmp_code; state_icmp = pf_icmp_mapping(pd, icmptype, &icmp_dir, &virtual_id, &virtual_type); if (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: icmptype = pd->hdr.icmp6->icmp6_type; icmpcode = pd->hdr.icmp6->icmp6_code; state_icmp = pf_icmp_mapping(pd, icmptype, &icmp_dir, &virtual_id, &virtual_type); if (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; r = TAILQ_FIRST(pf_main_ruleset.rules.active.ptr); while (r != NULL) { r->evaluations++; PF_TEST_ATTRIB((pfi_kif_match(r->kif, pd->kif) == r->ifnot), r->skip[PF_SKIP_IFP].ptr); PF_TEST_ATTRIB((r->direction && r->direction != pd->dir), r->skip[PF_SKIP_DIR].ptr); PF_TEST_ATTRIB((r->onrdomain >= 0 && (r->onrdomain == pd->rdomain) == r->ifnot), r->skip[PF_SKIP_RDOM].ptr); PF_TEST_ATTRIB((r->af && r->af != pd->af), r->skip[PF_SKIP_AF].ptr); PF_TEST_ATTRIB((r->proto && r->proto != pd->proto), r->skip[PF_SKIP_PROTO].ptr); PF_TEST_ATTRIB((PF_MISMATCHAW(&r->src.addr, &pd->nsaddr, pd->naf, r->src.neg, pd->kif, act.rtableid)), r->skip[PF_SKIP_SRC_ADDR].ptr); PF_TEST_ATTRIB((PF_MISMATCHAW(&r->dst.addr, &pd->ndaddr, pd->af, r->dst.neg, NULL, act.rtableid)), r->skip[PF_SKIP_DST_ADDR].ptr); switch (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((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 & th->th_flags) != r->flags), TAILQ_NEXT(r, entries)); PF_TEST_ATTRIB((r->os_fingerprint != PF_OSFP_ANY && !pf_osfp_match(pf_osfp_fingerprint(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], 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], 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 && (pd->lookup.done || (pd->lookup.done = pf_socket_lookup(pd), 1)) && !pf_match_uid(r->uid.op, r->uid.uid[0], r->uid.uid[1], pd->lookup.uid)), TAILQ_NEXT(r, entries)); /* tcp/udp only. gid.op always 0 in other cases */ PF_TEST_ATTRIB((r->gid.op && (pd->lookup.done || (pd->lookup.done = pf_socket_lookup(pd), 1)) && !pf_match_gid(r->gid.op, r->gid.gid[0], r->gid.gid[1], pd->lookup.gid)), TAILQ_NEXT(r, entries)); break; case IPPROTO_ICMP: case IPPROTO_ICMPV6: /* icmp only. type always 0 in other cases */ PF_TEST_ATTRIB((r->type && r->type != icmptype + 1), TAILQ_NEXT(r, entries)); /* icmp only. type always 0 in other cases */ PF_TEST_ATTRIB((r->code && r->code != icmpcode + 1), TAILQ_NEXT(r, entries)); /* icmp only. don't create states on replies */ PF_TEST_ATTRIB((r->keep_state && !state_icmp && (r->rule_flag & PFRULE_STATESLOPPY) == 0 && icmp_dir != PF_IN), TAILQ_NEXT(r, entries)); break; default: break; } PF_TEST_ATTRIB((r->rule_flag & PFRULE_FRAGMENT && pd->virtual_proto != PF_VPROTO_FRAGMENT), TAILQ_NEXT(r, entries)); PF_TEST_ATTRIB((r->tos && !(r->tos == 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(pd->m, r, &tag)), TAILQ_NEXT(r, entries)); PF_TEST_ATTRIB((r->rcv_kif && pf_match_rcvif(pd->m, r) == r->rcvifnot), TAILQ_NEXT(r, entries)); PF_TEST_ATTRIB((r->prio && (r->prio == PF_PRIO_ZERO ? 0 : r->prio) != pd->m->m_pkthdr.pf.prio), TAILQ_NEXT(r, entries)); /* FALLTHROUGH */ if (r->tag) tag = r->tag; if (r->anchor == NULL) { if (r->action == PF_MATCH) { if ((ri = pool_get(&pf_rule_item_pl, PR_NOWAIT)) == NULL) { REASON_SET(reason, PFRES_MEMORY); goto cleanup; } ri->r = r; /* order is irrelevant */ SLIST_INSERT_HEAD(&rules, ri, entry); pf_rule_to_actions(r, &act); if (r->rule_flag & PFRULE_AFTO) pd->naf = r->naf; if (pf_get_transaddr(r, pd, sns, &nr) == -1) { REASON_SET(reason, PFRES_TRANSLATE); goto cleanup; } #if NPFLOG > 0 if (r->log) { REASON_SET(reason, PFRES_MATCH); PFLOG_PACKET(pd, *reason, r, a, ruleset, NULL); } #endif /* NPFLOG > 0 */ } else { match = asd; *rm = r; *am = a; *rsm = ruleset; arsm = aruleset; } #if NPFLOG > 0 if (act.log & PF_LOG_MATCHES) pf_log_matches(pd, r, a, ruleset, &rules); #endif /* NPFLOG > 0 */ if (r->quick) break; r = TAILQ_NEXT(r, entries); } else { aruleset = ruleset; pf_step_into_anchor(&asd, &ruleset, &r, &a); } nextrule: if (r == NULL && pf_step_out_of_anchor(&asd, &ruleset, &r, &a, &match)) break; } r = *rm; /* matching rule */ a = *am; /* rule that defines an anchor containing 'r' */ ruleset = *rsm; /* ruleset of the anchor defined by the rule 'a' */ aruleset = arsm;/* ruleset of the 'a' rule itself */ /* apply actions for last matching pass/block rule */ pf_rule_to_actions(r, &act); if (r->rule_flag & PFRULE_AFTO) pd->naf = r->naf; if (pf_get_transaddr(r, pd, sns, &nr) == -1) { REASON_SET(reason, PFRES_TRANSLATE); goto cleanup; } REASON_SET(reason, PFRES_MATCH); #if NPFLOG > 0 if (r->log) PFLOG_PACKET(pd, *reason, r, a, ruleset, NULL); if (act.log & PF_LOG_MATCHES) pf_log_matches(pd, r, a, ruleset, &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)) && !(th->th_flags & TH_RST)) { u_int32_t ack = ntohl(th->th_seq) + pd->p_len; if (pf_check_proto_cksum(pd, pd->off, pd->tot_len - pd->off, IPPROTO_TCP, pd->af)) REASON_SET(reason, PFRES_PROTCKSUM); else { if (th->th_flags & TH_SYN) ack++; if (th->th_flags & TH_FIN) ack++; pf_send_tcp(r, pd->af, pd->dst, pd->src, th->th_dport, th->th_sport, ntohl(th->th_ack), ack, TH_RST|TH_ACK, 0, 0, r->return_ttl, 1, 0, pd->rdomain); } } else if ((pd->proto != IPPROTO_ICMP || ICMP_INFOTYPE(icmptype)) && pd->af == AF_INET && r->return_icmp) pf_send_icmp(pd->m, r->return_icmp >> 8, r->return_icmp & 255, pd->af, r, pd->rdomain); else if ((pd->proto != IPPROTO_ICMPV6 || (icmptype >= ICMP6_ECHO_REQUEST && icmptype != ND_REDIRECT)) && pd->af == AF_INET6 && r->return_icmp6) pf_send_icmp(pd->m, r->return_icmp6 >> 8, r->return_icmp6 & 255, pd->af, r, pd->rdomain); } if (r->action == PF_DROP) goto cleanup; pf_tag_packet(pd->m, tag, act.rtableid); if (act.rtableid >= 0 && rtable_l2(act.rtableid) != pd->rdomain) pd->destchg = 1; if (r->action == PF_PASS && pd->badopts && ! r->allow_opts) { 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_rule()"); goto cleanup; } action = PF_PASS; if (pd->virtual_proto != PF_VPROTO_FRAGMENT && !state_icmp && r->keep_state) { if (r->rule_flag & PFRULE_SRCTRACK && pf_insert_src_node(&sns[PF_SN_NONE], r, PF_SN_NONE, pd->af, pd->src, NULL) != 0) { REASON_SET(reason, PFRES_SRCLIMIT); goto cleanup; } if (r->max_states && (r->states_cur >= r->max_states)) { pf_status.lcounters[LCNT_STATES]++; REASON_SET(reason, PFRES_MAXSTATES); goto cleanup; } action = pf_create_state(pd, r, a, nr, &skw, &sks, &rewrite, sm, tag, &rules, &act, 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, icmp_dir); } #ifdef INET6 if (rewrite && skw->af != sks->af) action = PF_AFRT; #endif /* INET6 */ } else { while ((ri = SLIST_FIRST(&rules))) { SLIST_REMOVE_HEAD(&rules, entry); pool_put(&pf_rule_item_pl, ri); } } /* copy back packet headers if needed */ if (rewrite && pd->hdrlen) { pf_cksum(pd, pd->m); m_copyback(pd->m, pd->off, pd->hdrlen, pd->hdr.any, M_NOWAIT); } #if NPFSYNC > 0 if (*sm != NULL && !ISSET((*sm)->state_flags, PFSTATE_NOSYNC) && pd->dir == PF_OUT && pfsync_up()) { /* * We want the state created, but we dont * want to send this in case a partner * firewall has to know about it to allow * replies through it. */ if (pfsync_defer(*sm, pd->m)) return (PF_DEFER); } #endif /* NPFSYNC > 0 */ if (r->rule_flag & PFRULE_ONCE) pf_purge_rule(ruleset, r, aruleset, a); return (action); cleanup: while ((ri = SLIST_FIRST(&rules))) { SLIST_REMOVE_HEAD(&rules, entry); pool_put(&pf_rule_item_pl, 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 *s = NULL; struct tcphdr *th = pd->hdr.tcp; u_int16_t mss = tcp_mssdflt; u_short reason; u_int i; s = pool_get(&pf_state_pl, PR_NOWAIT | PR_ZERO); if (s == NULL) { REASON_SET(&reason, PFRES_MEMORY); goto csfailed; } s->rule.ptr = r; s->anchor.ptr = a; s->natrule.ptr = nr; if (r->allow_opts) s->state_flags |= PFSTATE_ALLOWOPTS; if (r->rule_flag & PFRULE_STATESLOPPY) s->state_flags |= PFSTATE_SLOPPY; if (r->rule_flag & PFRULE_PFLOW) s->state_flags |= PFSTATE_PFLOW; #if NPFLOG > 0 s->log = act->log & PF_LOG_ALL; #endif /* NPFLOG > 0 */ s->qid = act->qid; s->pqid = act->pqid; s->rtableid[pd->didx] = act->rtableid; s->rtableid[pd->sidx] = -1; /* return traffic is routed normally */ s->min_ttl = act->min_ttl; s->set_tos = act->set_tos; s->max_mss = act->max_mss; s->state_flags |= act->flags; #if NPFSYNC > 0 s->sync_state = PFSYNC_S_NONE; #endif /* NPFSYNC > 0 */ s->set_prio[0] = act->set_prio[0]; s->set_prio[1] = act->set_prio[1]; SLIST_INIT(&s->src_nodes); switch (pd->proto) { case IPPROTO_TCP: s->src.seqlo = ntohl(th->th_seq); s->src.seqhi = s->src.seqlo + pd->p_len + 1; if ((th->th_flags & (TH_SYN|TH_ACK)) == TH_SYN && r->keep_state == PF_STATE_MODULATE) { /* Generate sequence number modulator */ if ((s->src.seqdiff = pf_tcp_iss(pd) - s->src.seqlo) == 0) s->src.seqdiff = 1; pf_change_a(pd, &th->th_seq, htonl(s->src.seqlo + s->src.seqdiff)); *rewrite = 1; } else s->src.seqdiff = 0; if (th->th_flags & TH_SYN) { s->src.seqhi++; s->src.wscale = pf_get_wscale(pd); } s->src.max_win = MAX(ntohs(th->th_win), 1); if (s->src.wscale & PF_WSCALE_MASK) { /* Remove scale factor from initial window */ int win = s->src.max_win; win += 1 << (s->src.wscale & PF_WSCALE_MASK); s->src.max_win = (win - 1) >> (s->src.wscale & PF_WSCALE_MASK); } if (th->th_flags & TH_FIN) s->src.seqhi++; s->dst.seqhi = 1; s->dst.max_win = 1; s->src.state = TCPS_SYN_SENT; s->dst.state = TCPS_CLOSED; s->timeout = PFTM_TCP_FIRST_PACKET; break; case IPPROTO_UDP: s->src.state = PFUDPS_SINGLE; s->dst.state = PFUDPS_NO_TRAFFIC; s->timeout = PFTM_UDP_FIRST_PACKET; break; case IPPROTO_ICMP: #ifdef INET6 case IPPROTO_ICMPV6: #endif /* INET6 */ s->timeout = PFTM_ICMP_FIRST_PACKET; break; default: s->src.state = PFOTHERS_SINGLE; s->dst.state = PFOTHERS_NO_TRAFFIC; s->timeout = PFTM_OTHER_FIRST_PACKET; } s->creation = time_uptime; s->expire = time_uptime; if (pd->proto == IPPROTO_TCP) { if (s->state_flags & PFSTATE_SCRUB_TCP && pf_normalize_tcp_init(pd, &s->src)) { REASON_SET(&reason, PFRES_MEMORY); goto csfailed; } if (s->state_flags & PFSTATE_SCRUB_TCP && s->src.scrub && pf_normalize_tcp_stateful(pd, &reason, s, &s->src, &s->dst, rewrite)) { /* This really shouldn't happen!!! */ DPFPRINTF(LOG_ERR, "pf_normalize_tcp_stateful failed on first pkt"); goto csfailed; } } s->direction = pd->dir; if (pf_state_key_setup(pd, skw, sks, act->rtableid)) { REASON_SET(&reason, PFRES_MEMORY); 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(&s->src_nodes, sni, next); sni->sn->states++; } if (pf_set_rt_ifp(s, pd->src, (*skw)->af) != 0) { REASON_SET(&reason, PFRES_NOROUTE); goto csfailed; } if (pf_state_insert(BOUND_IFACE(r, pd->kif), skw, sks, s)) { pf_detach_state(s); *sks = *skw = NULL; REASON_SET(&reason, PFRES_STATEINS); goto csfailed; } else *sm = s; /* * Make state responsible for rules it binds here. */ memcpy(&s->match_rules, rules, sizeof(s->match_rules)); bzero(rules, sizeof(*rules)); STATE_INC_COUNTERS(s); if (tag > 0) { pf_tag_ref(tag); s->tag = tag; } if (pd->proto == IPPROTO_TCP && (th->th_flags & (TH_SYN|TH_ACK)) == TH_SYN && r->keep_state == PF_STATE_SYNPROXY) { int rtid = pd->rdomain; if (act->rtableid >= 0) rtid = act->rtableid; s->src.state = PF_TCPS_PROXY_SRC; s->src.seqhi = htonl(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); s->src.mss = mss; pf_send_tcp(r, pd->af, pd->dst, pd->src, th->th_dport, th->th_sport, s->src.seqhi, ntohl(th->th_seq) + 1, TH_SYN|TH_ACK, 0, s->src.mss, 0, 1, 0, pd->rdomain); REASON_SET(&reason, PFRES_SYNPROXY); return (PF_SYNPROXY_DROP); } return (PF_PASS); csfailed: if (s) { pf_normalize_tcp_cleanup(s); /* safe even w/o init */ pf_src_tree_remove_state(s); pool_put(&pf_state_pl, s); } 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) { /* * when called from bpf_mtap_pflog, there are extra constraints: * -mbuf is faked, m_data is the bpf buffer * -pd is not fully set up */ 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: if (afto || PF_ANEQ(saddr, pd->src, pd->af) || *pd->sport != sport) { pf_change_ap(pd, pd->src, pd->sport, saddr, sport); rewrite = 1; } if (afto || PF_ANEQ(daddr, pd->dst, pd->af) || *pd->dport != dport) { pf_change_ap(pd, pd->dst, pd->dport, daddr, dport); rewrite = 1; } break; case IPPROTO_UDP: if (afto || PF_ANEQ(saddr, pd->src, pd->af) || *pd->sport != sport) { pf_change_ap(pd, pd->src, pd->sport, saddr, sport); rewrite = 1; } if (afto || PF_ANEQ(daddr, pd->dst, pd->af) || *pd->dport != dport) { pf_change_ap(pd, pd->dst, pd->dport, daddr, dport); rewrite = 1; } break; case IPPROTO_ICMP: /* pf_translate() is also used when logging invalid packets */ if (pd->af != AF_INET) return (0); if (afto) { #ifdef INET6 if (pf_translate_icmp_af(AF_INET6, pd->hdr.icmp)) return (0); pd->proto = IPPROTO_ICMPV6; rewrite = 1; #endif /* INET6 */ } else { if (PF_ANEQ(saddr, pd->src, pd->af)) { pf_change_a(pd, &pd->src->v4.s_addr, saddr->v4.s_addr); rewrite = 1; } if (PF_ANEQ(daddr, pd->dst, pd->af)) { pf_change_a(pd, &pd->dst->v4.s_addr, daddr->v4.s_addr); rewrite = 1; } } if (virtual_type == htons(ICMP_ECHO)) { u_int16_t icmpid = (icmp_dir == PF_IN) ? sport : dport; if (icmpid != pd->hdr.icmp->icmp_id) { if (pd->csum_status == PF_CSUM_UNKNOWN) pf_check_proto_cksum(pd, pd->off, pd->tot_len - pd->off, pd->proto, pd->af); pd->hdr.icmp->icmp_id = icmpid; rewrite = 1; } } break; #ifdef INET6 case IPPROTO_ICMPV6: /* pf_translate() is also used when logging invalid packets */ if (pd->af != AF_INET6) return (0); if (afto) { /* ip_sum will be recalculated in pf_translate_af */ if (pf_translate_icmp_af(AF_INET, pd->hdr.icmp6)) return (0); pd->proto = IPPROTO_ICMP; rewrite = 1; } else { if (PF_ANEQ(saddr, pd->src, pd->af)) { pf_change_ap(pd, pd->src, NULL, saddr, 0); rewrite = 1; } if (PF_ANEQ(daddr, pd->dst, pd->af)) { pf_change_ap(pd, pd->dst, NULL, daddr, 0); rewrite = 1; } } if (virtual_type == htons(ICMP6_ECHO_REQUEST)) { u_int16_t icmpid = (icmp_dir == PF_IN) ? sport : dport; if (icmpid != pd->hdr.icmp6->icmp6_id) { if (pd->csum_status == PF_CSUM_UNKNOWN) pf_check_proto_cksum(pd, pd->off, pd->tot_len - pd->off, pd->proto, pd->af); pd->hdr.icmp6->icmp6_id = icmpid; rewrite = 1; } } break; #endif /* INET6 */ default: switch (pd->af) { case AF_INET: if (!afto && PF_ANEQ(saddr, pd->src, pd->af)) { pf_change_a(pd, &pd->src->v4.s_addr, saddr->v4.s_addr); rewrite = 1; } if (!afto && PF_ANEQ(daddr, pd->dst, pd->af)) { pf_change_a(pd, &pd->dst->v4.s_addr, daddr->v4.s_addr); rewrite = 1; } break; #ifdef INET6 case AF_INET6: if (!afto && PF_ANEQ(saddr, pd->src, pd->af)) { pf_change_ap(pd, pd->src, NULL, saddr, 0); rewrite = 1; } if (!afto && PF_ANEQ(daddr, pd->dst, pd->af)) { pf_change_ap(pd, pd->dst, NULL, daddr, 0); rewrite = 1; } break; #endif /* INET6 */ } } return (rewrite); } int pf_tcp_track_full(struct pf_pdesc *pd, struct pf_state_peer *src, struct pf_state_peer *dst, struct pf_state **state, u_short *reason, int *copyback) { struct tcphdr *th = pd->hdr.tcp; u_int16_t win = ntohs(th->th_win); u_int32_t ack, end, data_end, seq, orig_seq; u_int8_t sws, dws; int ackskew; if (src->wscale && dst->wscale && !(th->th_flags & TH_SYN)) { sws = src->wscale & PF_WSCALE_MASK; dws = dst->wscale & PF_WSCALE_MASK; } else sws = dws = 0; /* * Sequence tracking algorithm from Guido van Rooij's paper: * http://www.madison-gurkha.com/publications/tcp_filtering/ * tcp_filtering.ps */ orig_seq = seq = ntohl(th->th_seq); if (src->seqlo == 0) { /* First packet from this end. Set its state */ if (((*state)->state_flags & PFSTATE_SCRUB_TCP || dst->scrub) && src->scrub == NULL) { if (pf_normalize_tcp_init(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) ; ack = ntohl(th->th_ack) - dst->seqdiff; pf_change_a(pd, &th->th_seq, htonl(seq + src->seqdiff)); pf_change_a(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) src->state = TCPS_SYN_SENT; /* * May need to slide the window (seqhi may have been set by * the crappy stack check or if we picked up the connection * after establishment) */ if (src->seqhi == 1 || SEQ_GEQ(end + MAX(1, dst->max_win << dws), src->seqhi)) src->seqhi = end + MAX(1, dst->max_win << dws); if (win > src->max_win) src->max_win = win; } else { ack = ntohl(th->th_ack) - dst->seqdiff; if (src->seqdiff) { /* Modulate sequence numbers */ pf_change_a(pd, &th->th_seq, htonl(seq + src->seqdiff)); pf_change_a(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 accidently * SACK too far backwards of previously ACKed data. There really aren't * any security implications of bad SACKing unless the target stack * doesn't validate the option length correctly. Someone trying to * spoof into a TCP connection won't bother blindly sending SACK * options anyway. */ if (dst->seqdiff && (th->th_off << 2) > sizeof(struct tcphdr)) { if (pf_modulate_sack(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, *state, src, dst, copyback)) return (PF_DROP); } /* update max window */ if (src->max_win < win) src->max_win = win; /* synchronize sequencing */ if (SEQ_GT(end, src->seqlo)) src->seqlo = end; /* slide the window of what the other end can send */ if (SEQ_GEQ(ack + (win << sws), dst->seqhi)) dst->seqhi = ack + MAX((win << sws), 1); /* update states */ if (th->th_flags & TH_SYN) if (src->state < TCPS_SYN_SENT) src->state = TCPS_SYN_SENT; if (th->th_flags & TH_FIN) if (src->state < TCPS_CLOSING) src->state = TCPS_CLOSING; if (th->th_flags & TH_ACK) { if (dst->state == TCPS_SYN_SENT) { dst->state = TCPS_ESTABLISHED; if (src->state == TCPS_ESTABLISHED && !SLIST_EMPTY(&(*state)->src_nodes) && pf_src_connlimit(state)) { REASON_SET(reason, PFRES_SRCLIMIT); return (PF_DROP); } } else if (dst->state == TCPS_CLOSING) dst->state = TCPS_FIN_WAIT_2; } if (th->th_flags & TH_RST) src->state = dst->state = TCPS_TIME_WAIT; /* update expire time */ (*state)->expire = time_uptime; if (src->state >= TCPS_FIN_WAIT_2 && dst->state >= TCPS_FIN_WAIT_2) (*state)->timeout = PFTM_TCP_CLOSED; else if (src->state >= TCPS_CLOSING && dst->state >= TCPS_CLOSING) (*state)->timeout = PFTM_TCP_FIN_WAIT; else if (src->state < TCPS_ESTABLISHED || dst->state < TCPS_ESTABLISHED) (*state)->timeout = PFTM_TCP_OPENING; else if (src->state >= TCPS_CLOSING || dst->state >= TCPS_CLOSING) (*state)->timeout = PFTM_TCP_CLOSING; else (*state)->timeout = PFTM_TCP_ESTABLISHED; /* Fall through to PASS packet */ } else if ((dst->state < TCPS_SYN_SENT || dst->state >= TCPS_FIN_WAIT_2 || src->state >= TCPS_FIN_WAIT_2) && SEQ_GEQ(src->seqhi + MAXACKWINDOW, 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(*state); 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, (*state)->packets[0], (*state)->packets[1], pd->dir == PF_IN ? "in" : "out", pd->dir == (*state)->direction ? "fwd" : "rev"); } if (dst->scrub || src->scrub) { if (pf_normalize_tcp_stateful(pd, reason, *state, src, dst, copyback)) return (PF_DROP); } /* update max window */ if (src->max_win < win) src->max_win = win; /* synchronize sequencing */ if (SEQ_GT(end, src->seqlo)) src->seqlo = end; /* slide the window of what the other end can send */ if (SEQ_GEQ(ack + (win << sws), dst->seqhi)) dst->seqhi = ack + MAX((win << sws), 1); /* * Cannot set dst->seqhi here since this could be a shotgunned * SYN and not an already established connection. */ if (th->th_flags & TH_FIN) if (src->state < TCPS_CLOSING) src->state = TCPS_CLOSING; if (th->th_flags & TH_RST) src->state = dst->state = TCPS_TIME_WAIT; /* Fall through to PASS packet */ } else { if ((*state)->dst.state == TCPS_SYN_SENT && (*state)->src.state == TCPS_SYN_SENT) { /* Send RST for state mismatches during handshake */ if (!(th->th_flags & TH_RST)) pf_send_tcp((*state)->rule.ptr, pd->af, pd->dst, pd->src, th->th_dport, th->th_sport, ntohl(th->th_ack), 0, TH_RST, 0, 0, (*state)->rule.ptr->return_ttl, 1, 0, pd->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(*state); 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, (*state)->packets[0], (*state)->packets[1], pd->dir == PF_IN ? "in" : "out", pd->dir == (*state)->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_peer *src, struct pf_state_peer *dst, struct pf_state **state, u_short *reason) { struct tcphdr *th = pd->hdr.tcp; if (th->th_flags & TH_SYN) if (src->state < TCPS_SYN_SENT) src->state = TCPS_SYN_SENT; if (th->th_flags & TH_FIN) if (src->state < TCPS_CLOSING) src->state = TCPS_CLOSING; if (th->th_flags & TH_ACK) { if (dst->state == TCPS_SYN_SENT) { dst->state = TCPS_ESTABLISHED; if (src->state == TCPS_ESTABLISHED && !SLIST_EMPTY(&(*state)->src_nodes) && pf_src_connlimit(state)) { REASON_SET(reason, PFRES_SRCLIMIT); return (PF_DROP); } } else if (dst->state == TCPS_CLOSING) { dst->state = TCPS_FIN_WAIT_2; } else if (src->state == TCPS_SYN_SENT && dst->state < TCPS_SYN_SENT) { /* * Handle a special sloppy case where we only see one * half of the connection. If there is a ACK after * the initial SYN without ever seeing a packet from * the destination, set the connection to established. */ dst->state = src->state = TCPS_ESTABLISHED; if (!SLIST_EMPTY(&(*state)->src_nodes) && pf_src_connlimit(state)) { REASON_SET(reason, PFRES_SRCLIMIT); return (PF_DROP); } } else if (src->state == TCPS_CLOSING && dst->state == TCPS_ESTABLISHED && dst->seqlo == 0) { /* * Handle the closing of half connections where we * don't see the full bidirectional FIN/ACK+ACK * handshake. */ dst->state = TCPS_CLOSING; } } if (th->th_flags & TH_RST) src->state = dst->state = TCPS_TIME_WAIT; /* update expire time */ (*state)->expire = time_uptime; if (src->state >= TCPS_FIN_WAIT_2 && dst->state >= TCPS_FIN_WAIT_2) (*state)->timeout = PFTM_TCP_CLOSED; else if (src->state >= TCPS_CLOSING && dst->state >= TCPS_CLOSING) (*state)->timeout = PFTM_TCP_FIN_WAIT; else if (src->state < TCPS_ESTABLISHED || dst->state < TCPS_ESTABLISHED) (*state)->timeout = PFTM_TCP_OPENING; else if (src->state >= TCPS_CLOSING || dst->state >= TCPS_CLOSING) (*state)->timeout = PFTM_TCP_CLOSING; else (*state)->timeout = PFTM_TCP_ESTABLISHED; return (PF_PASS); } static __inline int pf_synproxy(struct pf_pdesc *pd, struct pf_state **state, u_short *reason) { struct pf_state_key *sk = (*state)->key[pd->didx]; if ((*state)->src.state == PF_TCPS_PROXY_SRC) { struct tcphdr *th = pd->hdr.tcp; if (pd->dir != (*state)->direction) { REASON_SET(reason, PFRES_SYNPROXY); return (PF_SYNPROXY_DROP); } if (th->th_flags & TH_SYN) { if (ntohl(th->th_seq) != (*state)->src.seqlo) { REASON_SET(reason, PFRES_SYNPROXY); return (PF_DROP); } pf_send_tcp((*state)->rule.ptr, pd->af, pd->dst, pd->src, th->th_dport, th->th_sport, (*state)->src.seqhi, ntohl(th->th_seq) + 1, TH_SYN|TH_ACK, 0, (*state)->src.mss, 0, 1, 0, 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) != (*state)->src.seqhi + 1) || (ntohl(th->th_seq) != (*state)->src.seqlo + 1)) { REASON_SET(reason, PFRES_SYNPROXY); return (PF_DROP); } else if (!SLIST_EMPTY(&(*state)->src_nodes) && pf_src_connlimit(state)) { REASON_SET(reason, PFRES_SRCLIMIT); return (PF_DROP); } else (*state)->src.state = PF_TCPS_PROXY_DST; } if ((*state)->src.state == PF_TCPS_PROXY_DST) { struct tcphdr *th = pd->hdr.tcp; if (pd->dir == (*state)->direction) { if (((th->th_flags & (TH_SYN|TH_ACK)) != TH_ACK) || (ntohl(th->th_ack) != (*state)->src.seqhi + 1) || (ntohl(th->th_seq) != (*state)->src.seqlo + 1)) { REASON_SET(reason, PFRES_SYNPROXY); return (PF_DROP); } (*state)->src.max_win = MAX(ntohs(th->th_win), 1); if ((*state)->dst.seqhi == 1) (*state)->dst.seqhi = htonl(arc4random()); pf_send_tcp((*state)->rule.ptr, pd->af, &sk->addr[pd->sidx], &sk->addr[pd->didx], sk->port[pd->sidx], sk->port[pd->didx], (*state)->dst.seqhi, 0, TH_SYN, 0, (*state)->src.mss, 0, 0, (*state)->tag, 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) != (*state)->dst.seqhi + 1)) { REASON_SET(reason, PFRES_SYNPROXY); return (PF_DROP); } else { (*state)->dst.max_win = MAX(ntohs(th->th_win), 1); (*state)->dst.seqlo = ntohl(th->th_seq); pf_send_tcp((*state)->rule.ptr, pd->af, pd->dst, pd->src, th->th_dport, th->th_sport, ntohl(th->th_ack), ntohl(th->th_seq) + 1, TH_ACK, (*state)->src.max_win, 0, 0, 0, (*state)->tag, pd->rdomain); pf_send_tcp((*state)->rule.ptr, pd->af, &sk->addr[pd->sidx], &sk->addr[pd->didx], sk->port[pd->sidx], sk->port[pd->didx], (*state)->src.seqhi + 1, (*state)->src.seqlo + 1, TH_ACK, (*state)->dst.max_win, 0, 0, 1, 0, sk->rdomain); (*state)->src.seqdiff = (*state)->dst.seqhi - (*state)->src.seqlo; (*state)->dst.seqdiff = (*state)->src.seqhi - (*state)->dst.seqlo; (*state)->src.seqhi = (*state)->src.seqlo + (*state)->dst.max_win; (*state)->dst.seqhi = (*state)->dst.seqlo + (*state)->src.max_win; (*state)->src.wscale = (*state)->dst.wscale = 0; (*state)->src.state = (*state)->dst.state = TCPS_ESTABLISHED; REASON_SET(reason, PFRES_SYNPROXY); return (PF_SYNPROXY_DROP); } } return (PF_PASS); } int pf_test_state(struct pf_pdesc *pd, struct pf_state **state, u_short *reason) { struct pf_state_key_cmp key; int copyback = 0; struct pf_state_peer *src, *dst; int action = PF_PASS; struct inpcb *inp; key.af = pd->af; key.proto = pd->virtual_proto; key.rdomain = pd->rdomain; PF_ACPY(&key.addr[pd->sidx], pd->src, key.af); PF_ACPY(&key.addr[pd->didx], pd->dst, key.af); key.port[pd->sidx] = pd->osport; key.port[pd->didx] = pd->odport; inp = pd->m->m_pkthdr.pf.inp; STATE_LOOKUP(pd->kif, &key, pd->dir, *state, pd->m); if (pd->dir == (*state)->direction) { src = &(*state)->src; dst = &(*state)->dst; } else { src = &(*state)->dst; dst = &(*state)->src; } switch (pd->virtual_proto) { case IPPROTO_TCP: if ((action = pf_synproxy(pd, state, reason)) != PF_PASS) return (action); if (((pd->hdr.tcp->th_flags & (TH_SYN|TH_ACK)) == TH_SYN) && 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(*state); pf_print_flags(pd->hdr.tcp->th_flags); addlog("\n"); } /* XXX make sure it's the same direction ?? */ (*state)->src.state = (*state)->dst.state = TCPS_CLOSED; pf_remove_state(*state); *state = NULL; pd->m->m_pkthdr.pf.inp = inp; return (PF_DROP); } if ((*state)->state_flags & PFSTATE_SLOPPY) { if (pf_tcp_track_sloppy(pd, src, dst, state, reason) == PF_DROP) return (PF_DROP); } else { int ret; if (PF_REVERSED_KEY((*state)->key, pd->af)) ret = pf_tcp_track_full(pd, dst, src, state, reason, ©back); else ret = pf_tcp_track_full(pd, src, dst, state, reason, ©back); if (ret == PF_DROP) return (PF_DROP); } break; case IPPROTO_UDP: /* update states */ if (src->state < PFUDPS_SINGLE) src->state = PFUDPS_SINGLE; if (dst->state == PFUDPS_SINGLE) dst->state = PFUDPS_MULTIPLE; /* update expire time */ (*state)->expire = time_uptime; if (src->state == PFUDPS_MULTIPLE && dst->state == PFUDPS_MULTIPLE) (*state)->timeout = PFTM_UDP_MULTIPLE; else (*state)->timeout = PFTM_UDP_SINGLE; break; default: /* update states */ if (src->state < PFOTHERS_SINGLE) src->state = PFOTHERS_SINGLE; if (dst->state == PFOTHERS_SINGLE) dst->state = PFOTHERS_MULTIPLE; /* update expire time */ (*state)->expire = time_uptime; if (src->state == PFOTHERS_MULTIPLE && dst->state == PFOTHERS_MULTIPLE) (*state)->timeout = PFTM_OTHER_MULTIPLE; else (*state)->timeout = PFTM_OTHER_SINGLE; break; } /* translate source/destination address, if necessary */ if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) { struct pf_state_key *nk; int afto, sidx, didx; if (PF_REVERSED_KEY((*state)->key, pd->af)) nk = (*state)->key[pd->sidx]; else nk = (*state)->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_ACPY(&pd->nsaddr, &nk->addr[sidx], nk->af); PF_ACPY(&pd->ndaddr, &nk->addr[didx], nk->af); pd->naf = nk->af; action = PF_AFRT; } #endif /* INET6 */ if (afto || PF_ANEQ(pd->src, &nk->addr[sidx], pd->af) || nk->port[sidx] != pd->osport) pf_change_ap(pd, pd->src, pd->sport, &nk->addr[sidx], nk->port[sidx]); if (afto || PF_ANEQ(pd->dst, &nk->addr[didx], pd->af) || pd->rdomain != nk->rdomain) pd->destchg = 1; if (afto || PF_ANEQ(pd->dst, &nk->addr[didx], pd->af) || nk->port[didx] != pd->odport) pf_change_ap(pd, pd->dst, pd->dport, &nk->addr[didx], nk->port[didx]); pd->m->m_pkthdr.ph_rtableid = nk->rdomain; copyback = 1; } if (copyback && pd->hdrlen > 0) { pf_cksum(pd, pd->m); m_copyback(pd->m, pd->off, pd->hdrlen, pd->hdr.any, M_NOWAIT); } return (action); } int pf_icmp_state_lookup(struct pf_pdesc *pd, struct pf_state_key_cmp *key, struct pf_state **state, u_int16_t icmpid, u_int16_t type, int icmp_dir, int *iidx, int multi, int inner) { int direction; 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); STATE_LOOKUP(pd->kif, key, pd->dir, *state, pd->m); if ((*state)->state_flags & PFSTATE_SLOPPY) return (-1); /* Is this ICMP message flowing in right direction? */ if ((*state)->key[PF_SK_WIRE]->af != (*state)->key[PF_SK_STACK]->af) direction = (pd->af == (*state)->key[PF_SK_WIRE]->af) ? PF_IN : PF_OUT; else direction = (*state)->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(*state); addlog("\n"); } return (PF_DROP); } return (-1); } int pf_test_state_icmp(struct pf_pdesc *pd, struct pf_state **state, u_short *reason) { struct pf_addr *saddr = pd->src, *daddr = pd->dst; u_int16_t virtual_id, virtual_type; u_int8_t icmptype; 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; break; #ifdef INET6 case IPPROTO_ICMPV6: icmptype = pd->hdr.icmp6->icmp6_type; 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, state, 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, state, virtual_id, virtual_type, icmp_dir, &iidx, 1, 0); if (ret >= 0) return (ret); (*state)->expire = time_uptime; (*state)->timeout = PFTM_ICMP_ERROR_REPLY; /* translate source/destination address, if necessary */ if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) { struct pf_state_key *nk; int afto, sidx, didx; if (PF_REVERSED_KEY((*state)->key, pd->af)) nk = (*state)->key[pd->sidx]; else nk = (*state)->key[pd->didx]; afto = pd->af != nk->af; sidx = afto ? pd->didx : pd->sidx; didx = afto ? pd->sidx : pd->didx; iidx = afto ? !iidx : iidx; if (pd->rdomain != nk->rdomain) 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(AF_INET6, pd->hdr.icmp)) return (PF_DROP); pd->proto = IPPROTO_ICMPV6; } #endif /* INET6 */ if (!afto && PF_ANEQ(pd->src, &nk->addr[sidx], AF_INET)) pf_change_a(pd, &saddr->v4.s_addr, nk->addr[sidx].v4.s_addr); if (!afto && PF_ANEQ(pd->dst, &nk->addr[didx], AF_INET)) { pf_change_a(pd, &daddr->v4.s_addr, nk->addr[didx].v4.s_addr); pd->destchg = 1; } if (nk->port[iidx] != pd->hdr.icmp->icmp_id) { if (pd->csum_status == PF_CSUM_UNKNOWN) pf_check_proto_cksum(pd, pd->off, pd->tot_len - pd->off, pd->proto, pd->af); 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(AF_INET, pd->hdr.icmp6)) return (PF_DROP); pd->proto = IPPROTO_ICMP; } if (!afto && PF_ANEQ(pd->src, &nk->addr[sidx], AF_INET6)) pf_change_ap(pd, saddr, NULL, &nk->addr[sidx], 0); if (!afto && PF_ANEQ(pd->dst, &nk->addr[didx], AF_INET6)) { pf_change_ap(pd, daddr, NULL, &nk->addr[didx], 0); pd->destchg = 1; } if (nk->port[iidx] != pd->hdr.icmp6->icmp6_id) { if (pd->csum_status == PF_CSUM_UNKNOWN) pf_check_proto_cksum(pd, pd->off, pd->tot_len - pd->off, pd->proto, pd->af); 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) { PF_ACPY(&pd->nsaddr, &nk->addr[sidx], nk->af); PF_ACPY(&pd->ndaddr, &nk->addr[didx], nk->af); pd->naf = nk->af; 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. */ bzero(&pd2, 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), NULL, 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 + (h2.ip_hl << 2); pd2.proto = h2.ip_p; pd2.tot_len = ntohs(h2.ip_len); 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), NULL, 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.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); } switch (pd2.proto) { case IPPROTO_TCP: { struct tcphdr th; u_int32_t seq; struct pf_state_peer *src, *dst; u_int8_t dws; /* * Only the first 8 bytes of the TCP header can be * expected. Don't access any TCP header fields after * th_seq, an ackskew test is not possible. */ if (!pf_pull_hdr(pd2.m, pd2.off, &th, 8, NULL, 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_ACPY(&key.addr[pd2.sidx], pd2.src, key.af); PF_ACPY(&key.addr[pd2.didx], pd2.dst, key.af); key.port[pd2.sidx] = th.th_sport; key.port[pd2.didx] = th.th_dport; STATE_LOOKUP(pd2.kif, &key, pd2.dir, *state, pd2.m); if (pd2.dir == (*state)->direction) { if (PF_REVERSED_KEY((*state)->key, pd->af)) { src = &(*state)->src; dst = &(*state)->dst; } else { src = &(*state)->dst; dst = &(*state)->src; } } else { if (PF_REVERSED_KEY((*state)->key, pd->af)) { src = &(*state)->dst; dst = &(*state)->src; } else { src = &(*state)->src; dst = &(*state)->dst; } } if (src->wscale && dst->wscale) dws = dst->wscale & PF_WSCALE_MASK; else dws = 0; /* Demodulate sequence number */ seq = ntohl(th.th_seq) - src->seqdiff; if (src->seqdiff) { pf_change_a(pd, &th.th_seq, htonl(seq)); copyback = 1; } if (!((*state)->state_flags & PFSTATE_SLOPPY) && (!SEQ_GEQ(src->seqhi, seq) || !SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)))) { if (pf_status.debug >= LOG_NOTICE) { log(LOG_NOTICE, "pf: BAD ICMP %d:%d ", icmptype, pd->hdr.icmp->icmp_code); pf_print_host(pd->src, 0, pd->af); addlog(" -> "); pf_print_host(pd->dst, 0, pd->af); addlog(" state: "); pf_print_state(*state); 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, pd->hdr.icmp->icmp_code); pf_print_host(pd->src, 0, pd->af); addlog(" -> "); pf_print_host(pd->dst, 0, pd->af); addlog(" state: "); pf_print_state(*state); addlog(" seq=%u\n", seq); } } /* translate source/destination address, if necessary */ if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) { struct pf_state_key *nk; int afto, sidx, didx; if (PF_REVERSED_KEY((*state)->key, pd->af)) nk = (*state)->key[pd->sidx]; else nk = (*state)->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(nk->af, pd->hdr.icmp)) return (PF_DROP); m_copyback(pd->m, pd->off, sizeof(struct icmp6_hdr), pd->hdr.icmp6, M_NOWAIT); 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_ACPY(&pd->nsaddr, &nk->addr[pd2.sidx], nk->af); PF_ACPY(&pd->ndaddr, &nk->addr[pd2.didx], nk->af); pd->naf = nk->af; if (pf_change_icmp_af(pd->m, ipoff2, pd, &pd2, &nk->addr[sidx], &nk->addr[didx], pd->af, nk->af)) return (PF_DROP); pf_change_ap(pd, pd2.src, &th.th_sport, &nk->addr[pd2.sidx], nk->port[sidx]); pf_change_ap(pd, pd2.dst, &th.th_dport, &nk->addr[pd2.didx], 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_change_icmp(pd, pd2.src, &th.th_sport, daddr, &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_change_icmp(pd, pd2.dst, &th.th_dport, saddr, &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; if (!pf_pull_hdr(pd2.m, pd2.off, &uh, sizeof(uh), NULL, 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_ACPY(&key.addr[pd2.sidx], pd2.src, key.af); PF_ACPY(&key.addr[pd2.didx], pd2.dst, key.af); key.port[pd2.sidx] = uh.uh_sport; key.port[pd2.didx] = uh.uh_dport; STATE_LOOKUP(pd2.kif, &key, pd2.dir, *state, pd2.m); /* translate source/destination address, if necessary */ if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) { struct pf_state_key *nk; int afto, sidx, didx; if (PF_REVERSED_KEY((*state)->key, pd->af)) nk = (*state)->key[pd->sidx]; else nk = (*state)->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(nk->af, pd->hdr.icmp)) return (PF_DROP); m_copyback(pd->m, pd->off, sizeof(struct icmp6_hdr), pd->hdr.icmp6, M_NOWAIT); 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_ACPY(&pd->nsaddr, &nk->addr[pd2.sidx], nk->af); PF_ACPY(&pd->ndaddr, &nk->addr[pd2.didx], nk->af); pd->naf = nk->af; if (pf_change_icmp_af(pd->m, ipoff2, pd, &pd2, &nk->addr[sidx], &nk->addr[didx], pd->af, nk->af)) return (PF_DROP); pf_change_ap(pd, pd2.src, &uh.uh_sport, &nk->addr[pd2.sidx], nk->port[sidx]); pf_change_ap(pd, pd2.dst, &uh.uh_dport, &nk->addr[pd2.didx], 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_change_icmp(pd, pd2.src, &uh.uh_sport, daddr, &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_change_icmp(pd, pd2.dst, &uh.uh_dport, saddr, &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 */ } uh.uh_sum = 0; m_copyback(pd2.m, pd2.off, sizeof(uh), &uh, M_NOWAIT); copyback = 1; } break; } case IPPROTO_ICMP: { struct icmp iih; if (pd2.af != AF_INET) { REASON_SET(reason, PFRES_NORM); return (PF_DROP); } if (!pf_pull_hdr(pd2.m, pd2.off, &iih, ICMP_MINLEN, NULL, reason, pd2.af)) { DPFPRINTF(LOG_NOTICE, "ICMP error message too short (icmp)"); return (PF_DROP); } pd2.hdr.icmp = &iih; pf_icmp_mapping(&pd2, iih.icmp_type, &icmp_dir, &virtual_id, &virtual_type); ret = pf_icmp_state_lookup(&pd2, &key, state, virtual_id, virtual_type, icmp_dir, &iidx, 0, 1); if (ret >= 0) return (ret); /* translate source/destination address, if necessary */ if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) { struct pf_state_key *nk; int afto, sidx, didx; if (PF_REVERSED_KEY((*state)->key, pd->af)) nk = (*state)->key[pd->sidx]; else nk = (*state)->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(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(nk->af, &iih)) return (PF_DROP); if (virtual_type == htons(ICMP_ECHO) && nk->port[iidx] != iih.icmp_id) 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_ACPY(&pd->nsaddr, &nk->addr[pd2.sidx], nk->af); PF_ACPY(&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_change_icmp(pd, pd2.src, (virtual_type == htons(ICMP_ECHO)) ? &iih.icmp_id : NULL, daddr, &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_change_icmp(pd, pd2.dst, NULL, saddr, &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; 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), NULL, reason, pd2.af)) { DPFPRINTF(LOG_NOTICE, "ICMP error message too short (icmp6)"); return (PF_DROP); } pd2.hdr.icmp6 = &iih; pf_icmp_mapping(&pd2, iih.icmp6_type, &icmp_dir, &virtual_id, &virtual_type); ret = pf_icmp_state_lookup(&pd2, &key, state, 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, state, virtual_id, virtual_type, icmp_dir, &iidx, 1, 1); if (ret >= 0) return (ret); /* translate source/destination address, if necessary */ if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) { struct pf_state_key *nk; int afto, sidx, didx; if (PF_REVERSED_KEY((*state)->key, pd->af)) nk = (*state)->key[pd->sidx]; else nk = (*state)->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(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(nk->af, &iih)) return (PF_DROP); if (virtual_type == htons(ICMP6_ECHO_REQUEST) && nk->port[iidx] != iih.icmp6_id) 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_ACPY(&pd->nsaddr, &nk->addr[pd2.sidx], nk->af); PF_ACPY(&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_change_icmp(pd, pd2.src, (virtual_type == htons(ICMP6_ECHO_REQUEST)) ? &iih.icmp6_id : NULL, daddr, &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_change_icmp(pd, pd2.dst, NULL, saddr, &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: { key.af = pd2.af; key.proto = pd2.proto; key.rdomain = pd2.rdomain; PF_ACPY(&key.addr[pd2.sidx], pd2.src, key.af); PF_ACPY(&key.addr[pd2.didx], pd2.dst, key.af); key.port[0] = key.port[1] = 0; STATE_LOOKUP(pd2.kif, &key, pd2.dir, *state, pd2.m); /* translate source/destination address, if necessary */ if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) { struct pf_state_key *nk = (*state)->key[pd->didx]; if (PF_ANEQ(pd2.src, &nk->addr[pd2.sidx], pd2.af)) pf_change_icmp(pd, pd2.src, NULL, daddr, &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_change_icmp(pd, pd2.dst, NULL, saddr, &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) { pf_cksum(pd, pd->m); m_copyback(pd->m, pd->off, pd->hdrlen, pd->hdr.any, 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 *actionp, u_short *reasonp, sa_family_t af) { 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) { if (fragoff >= len) ACTION_SET(actionp, PF_PASS); else { ACTION_SET(actionp, PF_DROP); REASON_SET(reasonp, PFRES_FRAG); } return (NULL); } if (m->m_pkthdr.len < off + len || ntohs(h->ip_len) < off + len) { ACTION_SET(actionp, PF_DROP); REASON_SET(reasonp, PFRES_SHORT); return (NULL); } break; } #ifdef INET6 case AF_INET6: { struct ip6_hdr *h = mtod(m, struct ip6_hdr *); if (m->m_pkthdr.len < off + len || (ntohs(h->ip6_plen) + sizeof(struct ip6_hdr)) < (unsigned)(off + len)) { ACTION_SET(actionp, PF_DROP); REASON_SET(reasonp, PFRES_SHORT); return (NULL); } break; } #endif /* INET6 */ } m_copydata(m, off, len, p); return (p); } int pf_routable(struct pf_addr *addr, sa_family_t af, struct pfi_kif *kif, 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, *rt0 = 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; rt0 = rtalloc((struct sockaddr *)&ss, 0, rtableid); if (rt0 != 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; rt = rt0; 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_carpdev == kif->pfik_ifp) ret = 1; if_put(ifp); #endif /* NCARP */ } #ifndef SMALL_KERNEL rt = rtable_mpath_next(rt); #else rt = NULL; #endif /* SMALL_KERNEL */ } while (check_mpath == 1 && rt != NULL && ret == 0); } else ret = 0; out: rtfree(rt0); 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((struct sockaddr *)&ss, RT_RESOLVE, rtableid); if (rt != NULL) { if (rt->rt_labelid == aw->v.rtlabel) ret = 1; rtfree(rt); } return (ret); } void pf_route(struct mbuf **m, struct pf_rule *r, int dir, struct ifnet *oifp, struct pf_state *s) { struct mbuf *m0, *m1; struct sockaddr_in *dst, sin; struct rtentry *rt = NULL; struct ip *ip; struct ifnet *ifp = NULL; struct pf_addr naddr; struct pf_src_node *sns[PF_SN_MAX]; int error = 0; unsigned int rtableid; if (m == NULL || *m == NULL || r == NULL || (dir != PF_IN && dir != PF_OUT) || oifp == NULL) panic("pf_route: invalid parameters"); if ((*m)->m_pkthdr.pf.routed++ > 3) { m0 = *m; *m = NULL; goto bad; } if (r->rt == PF_DUPTO) { if ((m0 = m_dup_pkt(*m, max_linkhdr, M_NOWAIT)) == NULL) return; } else { if ((r->rt == PF_REPLYTO) == (r->direction == dir)) return; m0 = *m; } if (m0->m_len < sizeof(struct ip)) { DPFPRINTF(LOG_ERR, "pf_route: m0->m_len < sizeof(struct ip)"); goto bad; } ip = mtod(m0, struct ip *); memset(&sin, 0, sizeof(sin)); dst = &sin; dst->sin_family = AF_INET; dst->sin_len = sizeof(*dst); dst->sin_addr = ip->ip_dst; rtableid = m0->m_pkthdr.ph_rtableid; if (!r->rt) { rt = rtalloc(sintosa(dst), RT_RESOLVE, rtableid); if (rt == NULL) { ipstat.ips_noroute++; goto bad; } ifp = if_get(rt->rt_ifidx); if (rt->rt_flags & RTF_GATEWAY) dst = satosin(rt->rt_gateway); m0->m_pkthdr.pf.flags |= PF_TAG_GENERATED; } else { if (s == NULL) { bzero(sns, sizeof(sns)); if (pf_map_addr(AF_INET, r, (struct pf_addr *)&ip->ip_src, &naddr, NULL, sns, &r->route, PF_SN_ROUTE)) { DPFPRINTF(LOG_ERR, "pf_route: pf_map_addr() failed."); goto bad; } if (!PF_AZERO(&naddr, AF_INET)) dst->sin_addr.s_addr = naddr.v4.s_addr; ifp = r->route.kif ? r->route.kif->pfik_ifp : NULL; } else { if (!PF_AZERO(&s->rt_addr, AF_INET)) dst->sin_addr.s_addr = s->rt_addr.v4.s_addr; ifp = s->rt_kif ? s->rt_kif->pfik_ifp : NULL; } rt = rtalloc(sintosa(dst), RT_RESOLVE, rtableid); if (rt == NULL) { ipstat.ips_noroute++; goto bad; } } if (ifp == NULL) goto bad; if (oifp != ifp) { 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, "pf_route: m0->m_len < sizeof(struct ip)"); goto bad; } ip = mtod(m0, struct ip *); } in_proto_cksum_out(m0, ifp); if (ntohs(ip->ip_len) <= ifp->if_mtu) { ip->ip_sum = 0; if (ifp->if_capabilities & IFCAP_CSUM_IPv4) m0->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; else { ipstat.ips_outswcsum++; ip->ip_sum = in_cksum(m0, ip->ip_hl << 2); } error = ifp->if_output(ifp, m0, sintosa(dst), rt); goto done; } /* * Too large for interface; fragment if possible. * Must be able to put at least 8 bytes per fragment. */ if (ip->ip_off & htons(IP_DF)) { ipstat.ips_cantfrag++; if (r->rt != PF_DUPTO) { icmp_error(m0, ICMP_UNREACH, ICMP_UNREACH_NEEDFRAG, 0, ifp->if_mtu); goto done; } else goto bad; } m1 = m0; error = ip_fragment(m0, ifp, ifp->if_mtu); if (error) { m0 = NULL; goto bad; } for (m0 = m1; m0; m0 = m1) { m1 = m0->m_nextpkt; m0->m_nextpkt = 0; if (error == 0) error = ifp->if_output(ifp, m0, sintosa(dst), rt); else m_freem(m0); } if (error == 0) ipstat.ips_fragmented++; done: if (r->rt != PF_DUPTO) *m = NULL; if (!r->rt) if_put(ifp); rtfree(rt); return; bad: m_freem(m0); goto done; } #ifdef INET6 void pf_route6(struct mbuf **m, struct pf_rule *r, int dir, struct ifnet *oifp, struct pf_state *s) { struct mbuf *m0; struct sockaddr_in6 *dst, sin6; struct ip6_hdr *ip6; struct ifnet *ifp = NULL; struct pf_addr naddr; struct pf_src_node *sns[PF_SN_MAX]; struct m_tag *mtag; if (m == NULL || *m == NULL || r == NULL || (dir != PF_IN && dir != PF_OUT) || oifp == NULL) panic("pf_route6: invalid parameters"); if ((*m)->m_pkthdr.pf.routed++ > 3) { m0 = *m; *m = NULL; goto bad; } if (r->rt == PF_DUPTO) { if ((m0 = m_dup_pkt(*m, max_linkhdr, M_NOWAIT)) == NULL) return; } else { if ((r->rt == PF_REPLYTO) == (r->direction == dir)) return; m0 = *m; } if (m0->m_len < sizeof(struct ip6_hdr)) { DPFPRINTF(LOG_ERR, "pf_route6: m0->m_len < sizeof(struct ip6_hdr)"); goto bad; } ip6 = mtod(m0, struct ip6_hdr *); memset(&sin6, 0, sizeof(sin6)); dst = &sin6; dst->sin6_family = AF_INET6; dst->sin6_len = sizeof(*dst); dst->sin6_addr = ip6->ip6_dst; if (!r->rt) { m0->m_pkthdr.pf.flags |= PF_TAG_GENERATED; ip6_output(m0, NULL, NULL, 0, NULL, NULL); return; } if (s == NULL) { bzero(sns, sizeof(sns)); if (pf_map_addr(AF_INET6, r, (struct pf_addr *)&ip6->ip6_src, &naddr, NULL, sns, &r->route, PF_SN_ROUTE)) { DPFPRINTF(LOG_ERR, "pf_route6: pf_map_addr() failed."); goto bad; } if (!PF_AZERO(&naddr, AF_INET6)) PF_ACPY((struct pf_addr *)&dst->sin6_addr, &naddr, AF_INET6); ifp = r->route.kif ? r->route.kif->pfik_ifp : NULL; } else { if (!PF_AZERO(&s->rt_addr, AF_INET6)) PF_ACPY((struct pf_addr *)&dst->sin6_addr, &s->rt_addr, AF_INET6); ifp = s->rt_kif ? s->rt_kif->pfik_ifp : NULL; } if (ifp == NULL) goto bad; if (oifp != ifp) { if (pf_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, "pf_route6: m0->m_len < sizeof(struct ip6_hdr)"); goto bad; } } in6_proto_cksum_out(m0, ifp); if (IN6_IS_SCOPE_EMBED(&dst->sin6_addr)) dst->sin6_addr.s6_addr16[1] = htons(ifp->if_index); /* * 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); } else if ((u_long)m0->m_pkthdr.len <= ifp->if_mtu) { nd6_output(ifp, m0, dst, NULL); } else { icmp6_error(m0, ICMP6_PACKET_TOO_BIG, 0, ifp->if_mtu); } done: if (r->rt != PF_DUPTO) *m = NULL; return; bad: m_freem(m0); goto done; } #endif /* INET6 */ /* * check protocol (tcp/udp/icmp/icmp6) checksum and set mbuf flag * off is the offset where the protocol header starts * len is the total length of protocol header plus payload * returns 0 when the checksum is valid, otherwise returns 1. * if the _OUT flag is set the checksum isn't done yet, consider these ok */ int pf_check_proto_cksum(struct pf_pdesc *pd, int off, int len, u_int8_t p, sa_family_t af) { u_int16_t flag_ok, flag_bad, flag_out; u_int16_t sum; if (pd->csum_status == PF_CSUM_OK) return (0); if (pd->csum_status == PF_CSUM_BAD) return (1); switch (p) { case IPPROTO_TCP: flag_ok = M_TCP_CSUM_IN_OK; flag_out = M_TCP_CSUM_OUT; flag_bad = M_TCP_CSUM_IN_BAD; break; case IPPROTO_UDP: flag_ok = M_UDP_CSUM_IN_OK; flag_out = M_UDP_CSUM_OUT; flag_bad = M_UDP_CSUM_IN_BAD; break; case IPPROTO_ICMP: #ifdef INET6 case IPPROTO_ICMPV6: #endif /* INET6 */ flag_ok = M_ICMP_CSUM_IN_OK; flag_out = M_ICMP_CSUM_OUT; flag_bad = M_ICMP_CSUM_IN_BAD; break; default: return (1); } if (pd->m->m_pkthdr.csum_flags & (flag_ok | flag_out)) { pd->csum_status = PF_CSUM_OK; return (0); } if (pd->m->m_pkthdr.csum_flags & flag_bad || off < sizeof(struct ip) || pd->m->m_pkthdr.len < off + len) { pd->csum_status = PF_CSUM_BAD; return (1); } /* need to do it in software */ if (p == IPPROTO_TCP) tcpstat.tcps_inswcsum++; else if (p == IPPROTO_UDP) udpstat.udps_inswcsum++; switch (af) { case AF_INET: if (pd->m->m_len < sizeof(struct ip)) { pd->csum_status = PF_CSUM_BAD; return (1); } sum = in4_cksum(pd->m, (p == IPPROTO_ICMP ? 0 : p), off, len); break; #ifdef INET6 case AF_INET6: if (pd->m->m_len < sizeof(struct ip6_hdr)) { pd->csum_status = PF_CSUM_BAD; return (1); } sum = in6_cksum(pd->m, p, off, len); break; #endif /* INET6 */ default: unhandled_af(af); } if (sum) { switch (p) { case IPPROTO_TCP: tcpstat.tcps_rcvbadsum++; break; case IPPROTO_UDP: udpstat.udps_badsum++; break; case IPPROTO_ICMP: icmpstat.icps_checksum++; break; #ifdef INET6 case IPPROTO_ICMPV6: icmp6stat.icp6s_checksum++; break; #endif /* INET6 */ } pd->m->m_pkthdr.csum_flags |= flag_bad; pd->csum_status = PF_CSUM_BAD; return (1); } pd->m->m_pkthdr.csum_flags |= flag_ok; pd->csum_status = PF_CSUM_OK; return (0); } struct pf_divert * pf_find_divert(struct mbuf *m) { struct m_tag *mtag; if ((mtag = m_tag_find(m, PACKET_TAG_PF_DIVERT, NULL)) == NULL) return (NULL); return ((struct pf_divert *)(mtag + 1)); } struct pf_divert * pf_get_divert(struct mbuf *m) { struct m_tag *mtag; if ((mtag = m_tag_find(m, PACKET_TAG_PF_DIVERT, NULL)) == NULL) { mtag = m_tag_get(PACKET_TAG_PF_DIVERT, sizeof(struct pf_divert), M_NOWAIT); if (mtag == NULL) return (NULL); bzero(mtag + 1, sizeof(struct pf_divert)); m_tag_prepend(m, mtag); } return ((struct pf_divert *)(mtag + 1)); } #ifdef 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), NULL, 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), NULL, 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_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), NULL, 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; default: 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 ip6_rthdr rthdr; u_int32_t end; int 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 (;;) { 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), NULL, 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), NULL, 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_AH: case IPPROTO_HOPOPTS: 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), NULL, 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) { if (pf_walk_option6(pd, h, pd->off + sizeof(ext), pd->off + (ext.ip6e_len + 1) * 8, reason) != PF_PASS) return (PF_DROP); if (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_TCP: case IPPROTO_UDP: case IPPROTO_ICMPV6: /* 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); } } } #endif /* INET6 */ int pf_setup_pdesc(struct pf_pdesc *pd, void *pdhdrs, sa_family_t af, int dir, struct pfi_kif *kif, struct mbuf *m, u_short *reason) { bzero(pd, sizeof(*pd)); pd->hdr.any = pdhdrs; 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 *); pd->off = h->ip_hl << 2; if (pd->off < sizeof(struct ip) || pd->off > ntohs(h->ip_len) || pd->m->m_pkthdr.len < ntohs(h->ip_len)) { REASON_SET(reason, PFRES_SHORT); return (PF_DROP); } pd->src = (struct pf_addr *)&h->ip_src; pd->dst = (struct pf_addr *)&h->ip_dst; pd->virtual_proto = pd->proto = h->ip_p; pd->tot_len = ntohs(h->ip_len); pd->tos = h->ip_tos & ~IPTOS_ECN_MASK; pd->ttl = h->ip_ttl; if (h->ip_hl > 5) /* has options */ pd->badopts++; if (h->ip_off & htons(IP_MF | IP_OFFMASK)) pd->virtual_proto = PF_VPROTO_FRAGMENT; 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 *); pd->off = 0; 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->virtual_proto = pd->proto; pd->tot_len = ntohs(h->ip6_plen) + sizeof(struct ip6_hdr); pd->tos = (ntohl(h->ip6_flow) & 0x0fc00000) >> 20; pd->ttl = h->ip6_hlim; if (pd->fragoff != 0) pd->virtual_proto = PF_VPROTO_FRAGMENT; break; } #endif /* INET6 */ default: panic("pf_setup_pdesc called with illegal af %u", pd->af); } PF_ACPY(&pd->nsaddr, pd->src, pd->af); PF_ACPY(&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), NULL, reason, pd->af)) return (PF_DROP); pd->hdrlen = sizeof(*th); if (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), NULL, 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, NULL, 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, NULL, 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); break; } if (icmp_hlen > sizeof(struct icmp6_hdr) && !pf_pull_hdr(pd->m, pd->off, pd->hdr.icmp6, icmp_hlen, NULL, 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); } break; } #endif /* INET6 */ } if (pd->sport) pd->osport = pd->nsport = *pd->sport; if (pd->dport) pd->odport = pd->ndport = *pd->dport; return (PF_PASS); } void pf_counters_inc(int action, struct pf_pdesc *pd, struct pf_state *s, 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 (s != NULL) { struct pf_rule_item *ri; struct pf_sn_item *sni; SLIST_FOREACH(sni, &s->src_nodes, next) { sni->sn->packets[dirndx]++; sni->sn->bytes[dirndx] += pd->tot_len; } dirndx = (pd->dir == s->direction) ? 0 : 1; s->packets[dirndx]++; s->bytes[dirndx] += pd->tot_len; SLIST_FOREACH(ri, &s->match_rules, entry) { ri->r->packets[dirndx]++; ri->r->bytes[dirndx] += pd->tot_len; if (ri->r->src.addr.type == PF_ADDR_TABLE) pfr_update_stats(ri->r->src.addr.p.tbl, &s->key[(s->direction == PF_IN)]-> addr[(s->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, &s->key[(s->direction == PF_IN)]-> addr[(s->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, (s == NULL) ? pd->src : &s->key[(s->direction == PF_IN)]-> addr[(s->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, (s == NULL) ? pd->dst : &s->key[(s->direction == PF_IN)]-> addr[(s->direction == PF_IN)], pd, r->action, r->dst.neg); } } int pf_test(sa_family_t af, int fwdir, struct ifnet *ifp, struct mbuf **m0) { struct pfi_kif *kif; u_short action, reason = 0; struct pf_rule *a = NULL, *r = &pf_default_rule; struct pf_state *s = NULL; struct pf_ruleset *ruleset = NULL; struct pf_pdesc pd; union pf_headers pdhdrs; int dir = (fwdir == PF_FWD) ? PF_OUT : fwdir; u_int32_t qid, pqid = 0; if (!pf_status.running) return (PF_PASS); #if NCARP > 0 if (ifp->if_type == IFT_CARP && ifp->if_carpdev) kif = (struct pfi_kif *)ifp->if_carpdev->if_pf_kif; else #endif /* NCARP */ kif = (struct pfi_kif *)ifp->if_pf_kif; if (kif == NULL) { DPFPRINTF(LOG_ERR, "pf_test: kif == NULL, if_xname %s", 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) 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, &pdhdrs, 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, &pdhdrs, af, dir, kif, *m0, &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; switch (pd.virtual_proto) { case PF_VPROTO_FRAGMENT: { /* * handle fragments that aren't reassembled by * normalization */ action = pf_test_rule(&pd, &r, &s, &a, &ruleset, &reason); 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"); goto done; } action = pf_test_state_icmp(&pd, &s, &reason); if (action == PF_PASS || action == PF_AFRT) { #if NPFSYNC > 0 pfsync_update_state(s); #endif /* NPFSYNC > 0 */ r = s->rule.ptr; a = s->anchor.ptr; #if NPFLOG > 0 pd.pflog |= s->log; #endif /* NPFLOG > 0 */ } else if (s == NULL) action = pf_test_rule(&pd, &r, &s, &a, &ruleset, &reason); 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"); goto done; } action = pf_test_state_icmp(&pd, &s, &reason); if (action == PF_PASS || action == PF_AFRT) { #if NPFSYNC > 0 pfsync_update_state(s); #endif /* NPFSYNC > 0 */ r = s->rule.ptr; a = s->anchor.ptr; #if NPFLOG > 0 pd.pflog |= s->log; #endif /* NPFLOG > 0 */ } else if (s == NULL) action = pf_test_rule(&pd, &r, &s, &a, &ruleset, &reason); break; } #endif /* INET6 */ default: if (pd.virtual_proto == IPPROTO_TCP) { if ((pd.hdr.tcp->th_flags & TH_ACK) && pd.p_len == 0) pqid = 1; action = pf_normalize_tcp(&pd); if (action == PF_DROP) goto done; } action = pf_test_state(&pd, &s, &reason); if (action == PF_PASS || action == PF_AFRT) { #if NPFSYNC > 0 pfsync_update_state(s); #endif /* NPFSYNC > 0 */ r = s->rule.ptr; a = s->anchor.ptr; #if NPFLOG > 0 pd.pflog |= s->log; #endif /* NPFLOG > 0 */ } else if (s == NULL) action = pf_test_rule(&pd, &r, &s, &a, &ruleset, &reason); if (pd.virtual_proto == IPPROTO_TCP) { if (s) { if (s->max_mss) pf_normalize_mss(&pd, s->max_mss); } else if (r->max_mss) pf_normalize_mss(&pd, r->max_mss); } break; } done: if (action != PF_DROP) { if (s) { /* The non-state case is handled in pf_test_rule() */ if (action == PF_PASS && pd.badopts && !(s->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, s->state_flags, pd.af, s->min_ttl, s->set_tos); pf_tag_packet(pd.m, s->tag, s->rtableid[pd.didx]); if (pqid || (pd.tos & IPTOS_LOWDELAY)) { qid = s->pqid; if (s->state_flags & PFSTATE_SETPRIO) pd.m->m_pkthdr.pf.prio = s->set_prio[1]; } else { qid = s->qid; if (s->state_flags & PFSTATE_SETPRIO) pd.m->m_pkthdr.pf.prio = s->set_prio[0]; } } 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]; } } } if (action == PF_PASS && qid) pd.m->m_pkthdr.pf.qid = qid; if (pd.dir == PF_IN && s && s->key[PF_SK_STACK]) { /* * Check below fires whenever caller forgets to call * pf_pkt_addr_changed(). This might happen when we * deal with IP tunnels. */ if (pd.m->m_pkthdr.pf.statekey != NULL) { #ifdef DDB m_print(pd.m, printf); #endif panic("incoming mbuf already has a statekey"); } pd.m->m_pkthdr.pf.statekey = pf_state_key_ref(s->key[PF_SK_STACK]); } if (pd.dir == PF_OUT && pd.m->m_pkthdr.pf.inp && !pd.m->m_pkthdr.pf.inp->inp_pf_sk && s && s->key[PF_SK_STACK] && !s->key[PF_SK_STACK]->inp) { pd.m->m_pkthdr.pf.inp->inp_pf_sk = pf_state_key_ref(s->key[PF_SK_STACK]); s->key[PF_SK_STACK]->inp = pd.m->m_pkthdr.pf.inp; } if (s) { pd.m->m_pkthdr.ph_flowid = M_FLOWID_VALID | (M_FLOWID_MASK & bemtoh64(&s->id)); } /* * connections redirected to loopback should not match sockets * bound specifically to loopback due to security implications, * see tcp_input() and 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.port) { struct pf_divert *divert; if ((divert = pf_get_divert(pd.m))) { pd.m->m_pkthdr.pf.flags |= PF_TAG_DIVERTED; divert->port = r->divert.port; divert->rdomain = pd.rdomain; divert->addr = r->divert.addr; } } if (action == PF_PASS && r->divert_packet.port) 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 (s) { SLIST_FOREACH(ri, &s->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, s, r, a); switch (action) { case PF_SYNPROXY_DROP: m_freem(*m0); case PF_DEFER: *m0 = NULL; action = PF_PASS; break; case PF_DIVERT: switch (pd.af) { case AF_INET: if (!divert_packet(pd.m, pd.dir, r->divert_packet.port)) *m0 = NULL; break; #ifdef INET6 case AF_INET6: if (!divert6_packet(pd.m, pd.dir, r->divert_packet.port)) *m0 = NULL; break; #endif /* INET6 */ } action = PF_PASS; break; #ifdef INET6 case PF_AFRT: if (pf_translate_af(&pd)) { if (!pd.m) *m0 = NULL; action = PF_DROP; break; } if (pd.naf == AF_INET) pf_route(&pd.m, r, dir, kif->pfik_ifp, s); if (pd.naf == AF_INET6) pf_route6(&pd.m, r, dir, kif->pfik_ifp, s); *m0 = NULL; action = PF_PASS; break; #endif /* INET6 */ case PF_DROP: m_freem(*m0); *m0 = NULL; break; default: /* pf_route can free the mbuf causing *m0 to become NULL */ if (r->rt) { switch (pd.af) { case AF_INET: pf_route(m0, r, pd.dir, pd.kif->pfik_ifp, s); break; #ifdef INET6 case AF_INET6: pf_route6(m0, r, pd.dir, pd.kif->pfik_ifp, s); break; #endif /* INET6 */ } } break; } #ifdef INET6 /* if reassembled packet passed, create new fragments */ if (pf_status.reass && action == PF_PASS && *m0 && fwdir == PF_FWD) { struct m_tag *mtag; if ((mtag = m_tag_find(*m0, PACKET_TAG_PF_REASSEMBLED, NULL))) action = pf_refragment6(m0, mtag, NULL, NULL); } #endif /* INET6 */ if (s && action != PF_DROP) { if (!s->if_index_in && dir == PF_IN) s->if_index_in = ifp->if_index; else if (!s->if_index_out && dir == PF_OUT) s->if_index_out = ifp->if_index; } return (action); } void pf_cksum(struct pf_pdesc *pd, struct mbuf *m) { if (pd->csum_status != PF_CSUM_OK) return; /* don't fix broken cksums */ switch (pd->proto) { case IPPROTO_TCP: pd->hdr.tcp->th_sum = 0; m->m_pkthdr.csum_flags |= M_TCP_CSUM_OUT; break; case IPPROTO_UDP: pd->hdr.udp->uh_sum = 0; m->m_pkthdr.csum_flags |= M_UDP_CSUM_OUT; break; case IPPROTO_ICMP: pd->hdr.icmp->icmp_cksum = 0; m->m_pkthdr.csum_flags |= M_ICMP_CSUM_OUT; break; #ifdef INET6 case IPPROTO_ICMPV6: pd->hdr.icmp6->icmp6_cksum = 0; m->m_pkthdr.csum_flags |= M_ICMP_CSUM_OUT; break; #endif /* INET6 */ default: /* nothing */ break; } } /* * must be called whenever any addressing information such as * address, port, protocol has changed */ void pf_pkt_addr_changed(struct mbuf *m) { pf_pkt_unlink_state_key(m); m->m_pkthdr.pf.inp = NULL; } 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_pkt_unlink_state_key(m); else inp = m->m_pkthdr.pf.statekey->inp; if (inp && inp->inp_pf_sk) KASSERT(m->m_pkthdr.pf.statekey == inp->inp_pf_sk); 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_pkt_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. */ if (inp && !sk->inp && !inp->inp_pf_sk) { sk->inp = inp; inp->inp_pf_sk = pf_state_key_ref(sk); } /* The statekey has finished finding the inp, it is no longer needed. */ pf_pkt_unlink_state_key(m); } void pf_inp_unlink(struct inpcb *inp) { if (inp->inp_pf_sk) { inp->inp_pf_sk->inp = NULL; pf_inpcb_unlink_state_key(inp); } } void pf_state_key_link(struct pf_state_key *sk, struct pf_state_key *pkt_sk) { /* * Assert will not wire as long as we are called by pf_find_state() */ KASSERT((pkt_sk->reverse == NULL) && (sk->reverse == NULL)); pkt_sk->reverse = pf_state_key_ref(sk); sk->reverse = pf_state_key_ref(pkt_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->refcnt); return (sk); } void pf_state_key_unref(struct pf_state_key *sk) { if ((sk != NULL) && PF_REF_RELE(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->reverse == NULL); /* state key must be unlinked from socket */ KASSERT((sk->inp == NULL) || (sk->inp->inp_pf_sk == NULL)); sk->inp = NULL; pool_put(&pf_state_key_pl, sk); } } int pf_state_key_isvalid(struct pf_state_key *sk) { return ((sk != NULL) && (sk->removed == 0)); } void pf_pkt_unlink_state_key(struct mbuf *m) { pf_state_key_unref(m->m_pkthdr.pf.statekey); m->m_pkthdr.pf.statekey = NULL; } void pf_pkt_state_key_ref(struct mbuf *m) { pf_state_key_ref(m->m_pkthdr.pf.statekey); } void pf_inpcb_unlink_state_key(struct inpcb *inp) { if (inp != NULL) { pf_state_key_unref(inp->inp_pf_sk); inp->inp_pf_sk = NULL; } } void pf_state_key_unlink_reverse(struct pf_state_key *sk) { if ((sk != NULL) && (sk->reverse != NULL)) { pf_state_key_unref(sk->reverse->reverse); sk->reverse->reverse = NULL; pf_state_key_unref(sk->reverse); sk->reverse = NULL; } }