/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2002-2009 Luigi Rizzo, Universita` di Pisa * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. 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 AUTHOR 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 AUTHOR 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. */ #include /* * The FreeBSD IP packet firewall, main file */ #include "opt_ipfw.h" #include "opt_ipdivert.h" #include "opt_inet.h" #ifndef INET #error "IPFIREWALL requires INET" #endif /* INET */ #include "opt_inet6.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* for ETHERTYPE_IP */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET6 #include #include #include #include #endif #include /* for struct grehdr */ #include #include /* XXX for in_cksum */ #ifdef MAC #include #endif #define IPFW_PROBE(probe, arg0, arg1, arg2, arg3, arg4, arg5) \ SDT_PROBE6(ipfw, , , probe, arg0, arg1, arg2, arg3, arg4, arg5) SDT_PROVIDER_DEFINE(ipfw); SDT_PROBE_DEFINE6(ipfw, , , rule__matched, "int", /* retval */ "int", /* af */ "void *", /* src addr */ "void *", /* dst addr */ "struct ip_fw_args *", /* args */ "struct ip_fw *" /* rule */); /* * static variables followed by global ones. * All ipfw global variables are here. */ VNET_DEFINE_STATIC(int, fw_deny_unknown_exthdrs); #define V_fw_deny_unknown_exthdrs VNET(fw_deny_unknown_exthdrs) VNET_DEFINE_STATIC(int, fw_permit_single_frag6) = 1; #define V_fw_permit_single_frag6 VNET(fw_permit_single_frag6) #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT static int default_to_accept = 1; #else static int default_to_accept; #endif VNET_DEFINE(int, autoinc_step); VNET_DEFINE(int, fw_one_pass) = 1; VNET_DEFINE(unsigned int, fw_tables_max); VNET_DEFINE(unsigned int, fw_tables_sets) = 0; /* Don't use set-aware tables */ /* Use 128 tables by default */ static unsigned int default_fw_tables = IPFW_TABLES_DEFAULT; static int jump_lookup_pos(struct ip_fw_chain *chain, struct ip_fw *f, int num, int tablearg, int jump_backwards); #ifndef LINEAR_SKIPTO static int jump_cached(struct ip_fw_chain *chain, struct ip_fw *f, int num, int tablearg, int jump_backwards); #define JUMP(ch, f, num, targ, back) jump_cached(ch, f, num, targ, back) #else #define JUMP(ch, f, num, targ, back) jump_lookup_pos(ch, f, num, targ, back) #endif /* * Each rule belongs to one of 32 different sets (0..31). * The variable set_disable contains one bit per set. * If the bit is set, all rules in the corresponding set * are disabled. Set RESVD_SET(31) is reserved for the default rule * and rules that are not deleted by the flush command, * and CANNOT be disabled. * Rules in set RESVD_SET can only be deleted individually. */ VNET_DEFINE(u_int32_t, set_disable); #define V_set_disable VNET(set_disable) VNET_DEFINE(int, fw_verbose); /* counter for ipfw_log(NULL...) */ VNET_DEFINE(u_int64_t, norule_counter); VNET_DEFINE(int, verbose_limit); /* layer3_chain contains the list of rules for layer 3 */ VNET_DEFINE(struct ip_fw_chain, layer3_chain); /* ipfw_vnet_ready controls when we are open for business */ VNET_DEFINE(int, ipfw_vnet_ready) = 0; VNET_DEFINE(int, ipfw_nat_ready) = 0; ipfw_nat_t *ipfw_nat_ptr = NULL; struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int); ipfw_nat_cfg_t *ipfw_nat_cfg_ptr; ipfw_nat_cfg_t *ipfw_nat_del_ptr; ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr; ipfw_nat_cfg_t *ipfw_nat_get_log_ptr; #ifdef SYSCTL_NODE uint32_t dummy_def = IPFW_DEFAULT_RULE; static int sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS); static int sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS); SYSBEGIN(f3) SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, "Firewall"); SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, one_pass, CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0, "Only do a single pass through ipfw when using dummynet(4)"); SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(autoinc_step), 0, "Rule number auto-increment step"); SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose, CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0, "Log matches to ipfw rules"); SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(verbose_limit), 0, "Set upper limit of matches of ipfw rules logged"); SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD, &dummy_def, 0, "The default/max possible rule number."); SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, tables_max, CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0, sysctl_ipfw_table_num, "IU", "Maximum number of concurrently used tables"); SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, tables_sets, CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0, sysctl_ipfw_tables_sets, "IU", "Use per-set namespace for tables"); SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN, &default_to_accept, 0, "Make the default rule accept all packets."); TUNABLE_INT("net.inet.ip.fw.tables_max", (int *)&default_fw_tables); SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0, "Number of static rules"); #ifdef INET6 SYSCTL_DECL(_net_inet6_ip6); SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, "Firewall"); SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs, CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_deny_unknown_exthdrs), 0, "Deny packets with unknown IPv6 Extension Headers"); SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, permit_single_frag6, CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE, &VNET_NAME(fw_permit_single_frag6), 0, "Permit single packet IPv6 fragments"); #endif /* INET6 */ SYSEND #endif /* SYSCTL_NODE */ /* * Some macros used in the various matching options. * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T * Other macros just cast void * into the appropriate type */ #define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl)) #define TCP(p) ((struct tcphdr *)(p)) #define SCTP(p) ((struct sctphdr *)(p)) #define UDP(p) ((struct udphdr *)(p)) #define ICMP(p) ((struct icmphdr *)(p)) #define ICMP6(p) ((struct icmp6_hdr *)(p)) static __inline int icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd) { int type = icmp->icmp_type; return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<icmp_type; return (type <= ICMP_MAXTYPE && (TT & (1<arg1 or cmd->d[0]. * * We scan options and store the bits we find set. We succeed if * * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear * * The code is sometimes optimized not to store additional variables. */ static int flags_match(ipfw_insn *cmd, u_int8_t bits) { u_char want_clear; bits = ~bits; if ( ((cmd->arg1 & 0xff) & bits) != 0) return 0; /* some bits we want set were clear */ want_clear = (cmd->arg1 >> 8) & 0xff; if ( (want_clear & bits) != want_clear) return 0; /* some bits we want clear were set */ return 1; } static int ipopts_match(struct ip *ip, ipfw_insn *cmd) { int optlen, bits = 0; u_char *cp = (u_char *)(ip + 1); int x = (ip->ip_hl << 2) - sizeof (struct ip); for (; x > 0; x -= optlen, cp += optlen) { int opt = cp[IPOPT_OPTVAL]; if (opt == IPOPT_EOL) break; if (opt == IPOPT_NOP) optlen = 1; else { optlen = cp[IPOPT_OLEN]; if (optlen <= 0 || optlen > x) return 0; /* invalid or truncated */ } switch (opt) { default: break; case IPOPT_LSRR: bits |= IP_FW_IPOPT_LSRR; break; case IPOPT_SSRR: bits |= IP_FW_IPOPT_SSRR; break; case IPOPT_RR: bits |= IP_FW_IPOPT_RR; break; case IPOPT_TS: bits |= IP_FW_IPOPT_TS; break; } } return (flags_match(cmd, bits)); } /* * Parse TCP options. The logic copied from tcp_dooptions(). */ static int tcpopts_parse(const struct tcphdr *tcp, uint16_t *mss) { const u_char *cp = (const u_char *)(tcp + 1); int optlen, bits = 0; int cnt = (tcp->th_off << 2) - sizeof(struct tcphdr); for (; cnt > 0; cnt -= optlen, cp += optlen) { int opt = cp[0]; if (opt == TCPOPT_EOL) break; if (opt == TCPOPT_NOP) optlen = 1; else { if (cnt < 2) break; optlen = cp[1]; if (optlen < 2 || optlen > cnt) break; } switch (opt) { default: break; case TCPOPT_MAXSEG: if (optlen != TCPOLEN_MAXSEG) break; bits |= IP_FW_TCPOPT_MSS; if (mss != NULL) *mss = be16dec(cp + 2); break; case TCPOPT_WINDOW: if (optlen == TCPOLEN_WINDOW) bits |= IP_FW_TCPOPT_WINDOW; break; case TCPOPT_SACK_PERMITTED: if (optlen == TCPOLEN_SACK_PERMITTED) bits |= IP_FW_TCPOPT_SACK; break; case TCPOPT_SACK: if (optlen > 2 && (optlen - 2) % TCPOLEN_SACK == 0) bits |= IP_FW_TCPOPT_SACK; break; case TCPOPT_TIMESTAMP: if (optlen == TCPOLEN_TIMESTAMP) bits |= IP_FW_TCPOPT_TS; break; } } return (bits); } static int tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd) { return (flags_match(cmd, tcpopts_parse(tcp, NULL))); } static int iface_match(struct ifnet *ifp, ipfw_insn_if *cmd, struct ip_fw_chain *chain, uint32_t *tablearg) { if (ifp == NULL) /* no iface with this packet, match fails */ return (0); /* Check by name or by IP address */ if (cmd->name[0] != '\0') { /* match by name */ if (cmd->name[0] == '\1') /* use tablearg to match */ return ipfw_lookup_table(chain, cmd->p.kidx, 0, &ifp->if_index, tablearg); /* Check name */ if (cmd->p.glob) { if (fnmatch(cmd->name, ifp->if_xname, 0) == 0) return(1); } else { if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0) return(1); } } else { #if !defined(USERSPACE) && defined(__FreeBSD__) /* and OSX too ? */ struct ifaddr *ia; NET_EPOCH_ASSERT(); CK_STAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { if (ia->ifa_addr->sa_family != AF_INET) continue; if (cmd->p.ip.s_addr == ((struct sockaddr_in *) (ia->ifa_addr))->sin_addr.s_addr) return (1); /* match */ } #endif /* __FreeBSD__ */ } return(0); /* no match, fail ... */ } /* * The verify_path function checks if a route to the src exists and * if it is reachable via ifp (when provided). * * The 'verrevpath' option checks that the interface that an IP packet * arrives on is the same interface that traffic destined for the * packet's source address would be routed out of. * The 'versrcreach' option just checks that the source address is * reachable via any route (except default) in the routing table. * These two are a measure to block forged packets. This is also * commonly known as "anti-spoofing" or Unicast Reverse Path * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs * is purposely reminiscent of the Cisco IOS command, * * ip verify unicast reverse-path * ip verify unicast source reachable-via any * * which implements the same functionality. But note that the syntax * is misleading, and the check may be performed on all IP packets * whether unicast, multicast, or broadcast. */ static int verify_path(struct in_addr src, struct ifnet *ifp, u_int fib) { #if defined(USERSPACE) || !defined(__FreeBSD__) return 0; #else struct nhop_object *nh; nh = fib4_lookup(fib, src, 0, NHR_NONE, 0); if (nh == NULL) return (0); /* * If ifp is provided, check for equality with rtentry. * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp, * in order to pass packets injected back by if_simloop(): * routing entry (via lo0) for our own address * may exist, so we need to handle routing assymetry. */ if (ifp != NULL && ifp != nh->nh_aifp) return (0); /* if no ifp provided, check if rtentry is not default route */ if (ifp == NULL && (nh->nh_flags & NHF_DEFAULT) != 0) return (0); /* or if this is a blackhole/reject route */ if (ifp == NULL && (nh->nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0) return (0); /* found valid route */ return 1; #endif /* __FreeBSD__ */ } /* * Generate an SCTP packet containing an ABORT chunk. The verification tag * is given by vtag. The T-bit is set in the ABORT chunk if and only if * reflected is not 0. */ static struct mbuf * ipfw_send_abort(struct mbuf *replyto, struct ipfw_flow_id *id, u_int32_t vtag, int reflected) { struct mbuf *m; struct ip *ip; #ifdef INET6 struct ip6_hdr *ip6; #endif struct sctphdr *sctp; struct sctp_chunkhdr *chunk; u_int16_t hlen, plen, tlen; MGETHDR(m, M_NOWAIT, MT_DATA); if (m == NULL) return (NULL); M_SETFIB(m, id->fib); #ifdef MAC if (replyto != NULL) mac_netinet_firewall_reply(replyto, m); else mac_netinet_firewall_send(m); #else (void)replyto; /* don't warn about unused arg */ #endif switch (id->addr_type) { case 4: hlen = sizeof(struct ip); break; #ifdef INET6 case 6: hlen = sizeof(struct ip6_hdr); break; #endif default: /* XXX: log me?!? */ FREE_PKT(m); return (NULL); } plen = sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr); tlen = hlen + plen; m->m_data += max_linkhdr; m->m_flags |= M_SKIP_FIREWALL; m->m_pkthdr.len = m->m_len = tlen; m->m_pkthdr.rcvif = NULL; bzero(m->m_data, tlen); switch (id->addr_type) { case 4: ip = mtod(m, struct ip *); ip->ip_v = 4; ip->ip_hl = sizeof(struct ip) >> 2; ip->ip_tos = IPTOS_LOWDELAY; ip->ip_len = htons(tlen); ip->ip_id = htons(0); ip->ip_off = htons(0); ip->ip_ttl = V_ip_defttl; ip->ip_p = IPPROTO_SCTP; ip->ip_sum = 0; ip->ip_src.s_addr = htonl(id->dst_ip); ip->ip_dst.s_addr = htonl(id->src_ip); sctp = (struct sctphdr *)(ip + 1); break; #ifdef INET6 case 6: ip6 = mtod(m, struct ip6_hdr *); ip6->ip6_vfc = IPV6_VERSION; ip6->ip6_plen = htons(plen); ip6->ip6_nxt = IPPROTO_SCTP; ip6->ip6_hlim = IPV6_DEFHLIM; ip6->ip6_src = id->dst_ip6; ip6->ip6_dst = id->src_ip6; sctp = (struct sctphdr *)(ip6 + 1); break; #endif } sctp->src_port = htons(id->dst_port); sctp->dest_port = htons(id->src_port); sctp->v_tag = htonl(vtag); sctp->checksum = htonl(0); chunk = (struct sctp_chunkhdr *)(sctp + 1); chunk->chunk_type = SCTP_ABORT_ASSOCIATION; chunk->chunk_flags = 0; if (reflected != 0) { chunk->chunk_flags |= SCTP_HAD_NO_TCB; } chunk->chunk_length = htons(sizeof(struct sctp_chunkhdr)); sctp->checksum = sctp_calculate_cksum(m, hlen); return (m); } /* * Generate a TCP packet, containing either a RST or a keepalive. * When flags & TH_RST, we are sending a RST packet, because of a * "reset" action matched the packet. * Otherwise we are sending a keepalive, and flags & TH_ * The 'replyto' mbuf is the mbuf being replied to, if any, and is required * so that MAC can label the reply appropriately. */ struct mbuf * ipfw_send_pkt(struct mbuf *replyto, struct ipfw_flow_id *id, u_int32_t seq, u_int32_t ack, int flags) { struct mbuf *m = NULL; /* stupid compiler */ struct ip *h = NULL; /* stupid compiler */ #ifdef INET6 struct ip6_hdr *h6 = NULL; #endif struct tcphdr *th = NULL; int len, dir; MGETHDR(m, M_NOWAIT, MT_DATA); if (m == NULL) return (NULL); M_SETFIB(m, id->fib); #ifdef MAC if (replyto != NULL) mac_netinet_firewall_reply(replyto, m); else mac_netinet_firewall_send(m); #else (void)replyto; /* don't warn about unused arg */ #endif switch (id->addr_type) { case 4: len = sizeof(struct ip) + sizeof(struct tcphdr); break; #ifdef INET6 case 6: len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr); break; #endif default: /* XXX: log me?!? */ FREE_PKT(m); return (NULL); } dir = ((flags & (TH_SYN | TH_RST)) == TH_SYN); m->m_data += max_linkhdr; m->m_flags |= M_SKIP_FIREWALL; m->m_pkthdr.len = m->m_len = len; m->m_pkthdr.rcvif = NULL; bzero(m->m_data, len); switch (id->addr_type) { case 4: h = mtod(m, struct ip *); /* prepare for checksum */ h->ip_p = IPPROTO_TCP; h->ip_len = htons(sizeof(struct tcphdr)); if (dir) { h->ip_src.s_addr = htonl(id->src_ip); h->ip_dst.s_addr = htonl(id->dst_ip); } else { h->ip_src.s_addr = htonl(id->dst_ip); h->ip_dst.s_addr = htonl(id->src_ip); } th = (struct tcphdr *)(h + 1); break; #ifdef INET6 case 6: h6 = mtod(m, struct ip6_hdr *); /* prepare for checksum */ h6->ip6_nxt = IPPROTO_TCP; h6->ip6_plen = htons(sizeof(struct tcphdr)); if (dir) { h6->ip6_src = id->src_ip6; h6->ip6_dst = id->dst_ip6; } else { h6->ip6_src = id->dst_ip6; h6->ip6_dst = id->src_ip6; } th = (struct tcphdr *)(h6 + 1); break; #endif } if (dir) { th->th_sport = htons(id->src_port); th->th_dport = htons(id->dst_port); } else { th->th_sport = htons(id->dst_port); th->th_dport = htons(id->src_port); } th->th_off = sizeof(struct tcphdr) >> 2; if (flags & TH_RST) { if (flags & TH_ACK) { th->th_seq = htonl(ack); th->th_flags = TH_RST; } else { if (flags & TH_SYN) seq++; th->th_ack = htonl(seq); th->th_flags = TH_RST | TH_ACK; } } else { /* * Keepalive - use caller provided sequence numbers */ th->th_seq = htonl(seq); th->th_ack = htonl(ack); th->th_flags = TH_ACK; } switch (id->addr_type) { case 4: th->th_sum = in_cksum(m, len); /* finish the ip header */ h->ip_v = 4; h->ip_hl = sizeof(*h) >> 2; h->ip_tos = IPTOS_LOWDELAY; h->ip_off = htons(0); h->ip_len = htons(len); h->ip_ttl = V_ip_defttl; h->ip_sum = 0; break; #ifdef INET6 case 6: th->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(*h6), sizeof(struct tcphdr)); /* finish the ip6 header */ h6->ip6_vfc |= IPV6_VERSION; h6->ip6_hlim = IPV6_DEFHLIM; break; #endif } return (m); } #ifdef INET6 /* * ipv6 specific rules here... */ static __inline int icmp6type_match(int type, ipfw_insn_u32 *cmd) { return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) ); } static int flow6id_match(int curr_flow, ipfw_insn_u32 *cmd) { int i; for (i=0; i <= cmd->o.arg1; ++i) if (curr_flow == cmd->d[i]) return 1; return 0; } /* support for IP6_*_ME opcodes */ static const struct in6_addr lla_mask = {{{ 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }}}; static int ipfw_localip6(struct in6_addr *in6) { struct rm_priotracker in6_ifa_tracker; struct in6_ifaddr *ia; if (IN6_IS_ADDR_MULTICAST(in6)) return (0); if (!IN6_IS_ADDR_LINKLOCAL(in6)) return (in6_localip(in6)); IN6_IFADDR_RLOCK(&in6_ifa_tracker); CK_STAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) { if (!IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) continue; if (IN6_ARE_MASKED_ADDR_EQUAL(&ia->ia_addr.sin6_addr, in6, &lla_mask)) { IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); return (1); } } IN6_IFADDR_RUNLOCK(&in6_ifa_tracker); return (0); } static int verify_path6(struct in6_addr *src, struct ifnet *ifp, u_int fib) { struct nhop_object *nh; if (IN6_IS_SCOPE_LINKLOCAL(src)) return (1); nh = fib6_lookup(fib, src, 0, NHR_NONE, 0); if (nh == NULL) return (0); /* If ifp is provided, check for equality with route table. */ if (ifp != NULL && ifp != nh->nh_aifp) return (0); /* if no ifp provided, check if rtentry is not default route */ if (ifp == NULL && (nh->nh_flags & NHF_DEFAULT) != 0) return (0); /* or if this is a blackhole/reject route */ if (ifp == NULL && (nh->nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0) return (0); /* found valid route */ return 1; } static int is_icmp6_query(int icmp6_type) { if ((icmp6_type <= ICMP6_MAXTYPE) && (icmp6_type == ICMP6_ECHO_REQUEST || icmp6_type == ICMP6_MEMBERSHIP_QUERY || icmp6_type == ICMP6_WRUREQUEST || icmp6_type == ICMP6_FQDN_QUERY || icmp6_type == ICMP6_NI_QUERY)) return (1); return (0); } static int map_icmp_unreach(int code) { /* RFC 7915 p4.2 */ switch (code) { case ICMP_UNREACH_NET: case ICMP_UNREACH_HOST: case ICMP_UNREACH_SRCFAIL: case ICMP_UNREACH_NET_UNKNOWN: case ICMP_UNREACH_HOST_UNKNOWN: case ICMP_UNREACH_TOSNET: case ICMP_UNREACH_TOSHOST: return (ICMP6_DST_UNREACH_NOROUTE); case ICMP_UNREACH_PORT: return (ICMP6_DST_UNREACH_NOPORT); default: /* * Map the rest of codes into admit prohibited. * XXX: unreach proto should be mapped into ICMPv6 * parameter problem, but we use only unreach type. */ return (ICMP6_DST_UNREACH_ADMIN); } } static void send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6) { struct mbuf *m; m = args->m; if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) { struct tcphdr *tcp; tcp = (struct tcphdr *)((char *)ip6 + hlen); if ((tcp->th_flags & TH_RST) == 0) { struct mbuf *m0; m0 = ipfw_send_pkt(args->m, &(args->f_id), ntohl(tcp->th_seq), ntohl(tcp->th_ack), tcp->th_flags | TH_RST); if (m0 != NULL) ip6_output(m0, NULL, NULL, 0, NULL, NULL, NULL); } FREE_PKT(m); } else if (code == ICMP6_UNREACH_ABORT && args->f_id.proto == IPPROTO_SCTP) { struct mbuf *m0; struct sctphdr *sctp; u_int32_t v_tag; int reflected; sctp = (struct sctphdr *)((char *)ip6 + hlen); reflected = 1; v_tag = ntohl(sctp->v_tag); /* Investigate the first chunk header if available */ if (m->m_len >= hlen + sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr)) { struct sctp_chunkhdr *chunk; chunk = (struct sctp_chunkhdr *)(sctp + 1); switch (chunk->chunk_type) { case SCTP_INITIATION: /* * Packets containing an INIT chunk MUST have * a zero v-tag. */ if (v_tag != 0) { v_tag = 0; break; } /* INIT chunk MUST NOT be bundled */ if (m->m_pkthdr.len > hlen + sizeof(struct sctphdr) + ntohs(chunk->chunk_length) + 3) { break; } /* Use the initiate tag if available */ if ((m->m_len >= hlen + sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr) + offsetof(struct sctp_init, a_rwnd))) { struct sctp_init *init; init = (struct sctp_init *)(chunk + 1); v_tag = ntohl(init->initiate_tag); reflected = 0; } break; case SCTP_ABORT_ASSOCIATION: /* * If the packet contains an ABORT chunk, don't * reply. * XXX: We should search through all chunks, * but do not do that to avoid attacks. */ v_tag = 0; break; } } if (v_tag == 0) { m0 = NULL; } else { m0 = ipfw_send_abort(args->m, &(args->f_id), v_tag, reflected); } if (m0 != NULL) ip6_output(m0, NULL, NULL, 0, NULL, NULL, NULL); FREE_PKT(m); } else if (code != ICMP6_UNREACH_RST && code != ICMP6_UNREACH_ABORT) { /* Send an ICMPv6 unreach. */ #if 0 /* * Unlike above, the mbufs need to line up with the ip6 hdr, * as the contents are read. We need to m_adj() the * needed amount. * The mbuf will however be thrown away so we can adjust it. * Remember we did an m_pullup on it already so we * can make some assumptions about contiguousness. */ if (args->L3offset) m_adj(m, args->L3offset); #endif icmp6_error(m, ICMP6_DST_UNREACH, code, 0); } else FREE_PKT(m); args->m = NULL; } #endif /* INET6 */ /* * sends a reject message, consuming the mbuf passed as an argument. */ static void send_reject(struct ip_fw_args *args, const ipfw_insn *cmd, int iplen, struct ip *ip) { int code, mtu; code = cmd->arg1; if (code == ICMP_UNREACH_NEEDFRAG && cmd->len == F_INSN_SIZE(ipfw_insn_u16)) mtu = ((const ipfw_insn_u16 *)cmd)->ports[0]; else mtu = 0; #if 0 /* XXX When ip is not guaranteed to be at mtod() we will * need to account for this */ * The mbuf will however be thrown away so we can adjust it. * Remember we did an m_pullup on it already so we * can make some assumptions about contiguousness. */ if (args->L3offset) m_adj(m, args->L3offset); #endif if (code != ICMP_REJECT_RST && code != ICMP_REJECT_ABORT) { /* Send an ICMP unreach */ icmp_error(args->m, ICMP_UNREACH, code, 0L, mtu); } else if (code == ICMP_REJECT_RST && args->f_id.proto == IPPROTO_TCP) { struct tcphdr *const tcp = L3HDR(struct tcphdr, mtod(args->m, struct ip *)); if ( (tcp->th_flags & TH_RST) == 0) { struct mbuf *m; m = ipfw_send_pkt(args->m, &(args->f_id), ntohl(tcp->th_seq), ntohl(tcp->th_ack), tcp->th_flags | TH_RST); if (m != NULL) ip_output(m, NULL, NULL, 0, NULL, NULL); } FREE_PKT(args->m); } else if (code == ICMP_REJECT_ABORT && args->f_id.proto == IPPROTO_SCTP) { struct mbuf *m; struct sctphdr *sctp; struct sctp_chunkhdr *chunk; struct sctp_init *init; u_int32_t v_tag; int reflected; sctp = L3HDR(struct sctphdr, mtod(args->m, struct ip *)); reflected = 1; v_tag = ntohl(sctp->v_tag); if (iplen >= (ip->ip_hl << 2) + sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr)) { /* Look at the first chunk header if available */ chunk = (struct sctp_chunkhdr *)(sctp + 1); switch (chunk->chunk_type) { case SCTP_INITIATION: /* * Packets containing an INIT chunk MUST have * a zero v-tag. */ if (v_tag != 0) { v_tag = 0; break; } /* INIT chunk MUST NOT be bundled */ if (iplen > (ip->ip_hl << 2) + sizeof(struct sctphdr) + ntohs(chunk->chunk_length) + 3) { break; } /* Use the initiate tag if available */ if ((iplen >= (ip->ip_hl << 2) + sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr) + offsetof(struct sctp_init, a_rwnd))) { init = (struct sctp_init *)(chunk + 1); v_tag = ntohl(init->initiate_tag); reflected = 0; } break; case SCTP_ABORT_ASSOCIATION: /* * If the packet contains an ABORT chunk, don't * reply. * XXX: We should search through all chunks, * but do not do that to avoid attacks. */ v_tag = 0; break; } } if (v_tag == 0) { m = NULL; } else { m = ipfw_send_abort(args->m, &(args->f_id), v_tag, reflected); } if (m != NULL) ip_output(m, NULL, NULL, 0, NULL, NULL); FREE_PKT(args->m); } else FREE_PKT(args->m); args->m = NULL; } /* * Support for uid/gid/jail lookup. These tests are expensive * (because we may need to look into the list of active sockets) * so we cache the results. ugid_lookupp is 0 if we have not * yet done a lookup, 1 if we succeeded, and -1 if we tried * and failed. The function always returns the match value. * We could actually spare the variable and use *uc, setting * it to '(void *)check_uidgid if we have no info, NULL if * we tried and failed, or any other value if successful. */ static int check_uidgid(ipfw_insn_u32 *insn, struct ip_fw_args *args, int *ugid_lookupp, struct ucred **uc) { #if defined(USERSPACE) return 0; // not supported in userspace #else #ifndef __FreeBSD__ /* XXX */ return cred_check(insn, proto, oif, dst_ip, dst_port, src_ip, src_port, (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb); #else /* FreeBSD */ struct in_addr src_ip, dst_ip; struct inpcbinfo *pi; struct ipfw_flow_id *id; struct inpcb *pcb, *inp; int lookupflags; int match; id = &args->f_id; inp = args->inp; /* * Check to see if the UDP or TCP stack supplied us with * the PCB. If so, rather then holding a lock and looking * up the PCB, we can use the one that was supplied. */ if (inp && *ugid_lookupp == 0) { INP_LOCK_ASSERT(inp); if (inp->inp_socket != NULL) { *uc = crhold(inp->inp_cred); *ugid_lookupp = 1; } else *ugid_lookupp = -1; } /* * If we have already been here and the packet has no * PCB entry associated with it, then we can safely * assume that this is a no match. */ if (*ugid_lookupp == -1) return (0); if (id->proto == IPPROTO_TCP) { lookupflags = 0; pi = &V_tcbinfo; } else if (id->proto == IPPROTO_UDP) { lookupflags = INPLOOKUP_WILDCARD; pi = &V_udbinfo; } else if (id->proto == IPPROTO_UDPLITE) { lookupflags = INPLOOKUP_WILDCARD; pi = &V_ulitecbinfo; } else return 0; lookupflags |= INPLOOKUP_RLOCKPCB; match = 0; if (*ugid_lookupp == 0) { if (id->addr_type == 6) { #ifdef INET6 if (args->flags & IPFW_ARGS_IN) pcb = in6_pcblookup_mbuf(pi, &id->src_ip6, htons(id->src_port), &id->dst_ip6, htons(id->dst_port), lookupflags, NULL, args->m); else pcb = in6_pcblookup_mbuf(pi, &id->dst_ip6, htons(id->dst_port), &id->src_ip6, htons(id->src_port), lookupflags, args->ifp, args->m); #else *ugid_lookupp = -1; return (0); #endif } else { src_ip.s_addr = htonl(id->src_ip); dst_ip.s_addr = htonl(id->dst_ip); if (args->flags & IPFW_ARGS_IN) pcb = in_pcblookup_mbuf(pi, src_ip, htons(id->src_port), dst_ip, htons(id->dst_port), lookupflags, NULL, args->m); else pcb = in_pcblookup_mbuf(pi, dst_ip, htons(id->dst_port), src_ip, htons(id->src_port), lookupflags, args->ifp, args->m); } if (pcb != NULL) { INP_RLOCK_ASSERT(pcb); *uc = crhold(pcb->inp_cred); *ugid_lookupp = 1; INP_RUNLOCK(pcb); } if (*ugid_lookupp == 0) { /* * We tried and failed, set the variable to -1 * so we will not try again on this packet. */ *ugid_lookupp = -1; return (0); } } if (insn->o.opcode == O_UID) match = ((*uc)->cr_uid == (uid_t)insn->d[0]); else if (insn->o.opcode == O_GID) match = groupmember((gid_t)insn->d[0], *uc); else if (insn->o.opcode == O_JAIL) match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]); return (match); #endif /* __FreeBSD__ */ #endif /* not supported in userspace */ } /* * Helper function to set args with info on the rule after the matching * one. slot is precise, whereas we guess rule_id as they are * assigned sequentially. */ static inline void set_match(struct ip_fw_args *args, int slot, struct ip_fw_chain *chain) { args->rule.chain_id = chain->id; args->rule.slot = slot + 1; /* we use 0 as a marker */ args->rule.rule_id = 1 + chain->map[slot]->id; args->rule.rulenum = chain->map[slot]->rulenum; args->flags |= IPFW_ARGS_REF; } static int jump_lookup_pos(struct ip_fw_chain *chain, struct ip_fw *f, int num, int tablearg, int jump_backwards) { int f_pos, i; i = IP_FW_ARG_TABLEARG(chain, num, skipto); /* make sure we do not jump backward */ if (jump_backwards == 0 && i <= f->rulenum) i = f->rulenum + 1; #ifndef LINEAR_SKIPTO if (chain->idxmap != NULL) f_pos = chain->idxmap[i]; else f_pos = ipfw_find_rule(chain, i, 0); #else f_pos = chain->idxmap[i]; #endif /* LINEAR_SKIPTO */ return (f_pos); } #ifndef LINEAR_SKIPTO /* * Helper function to enable cached rule lookups using * cache.id and cache.pos fields in ipfw rule. */ static int jump_cached(struct ip_fw_chain *chain, struct ip_fw *f, int num, int tablearg, int jump_backwards) { int f_pos; /* Can't use cache with IP_FW_TARG */ if (num == IP_FW_TARG) return jump_lookup_pos(chain, f, num, tablearg, jump_backwards); /* * If possible use cached f_pos (in f->cache.pos), * whose version is written in f->cache.id (horrible hacks * to avoid changing the ABI). * * Multiple threads can execute the same rule simultaneously, * we need to ensure that cache.pos is updated before cache.id. */ #ifdef __LP64__ struct ip_fw_jump_cache cache; cache.raw_value = f->cache.raw_value; if (cache.id == chain->id) return (cache.pos); f_pos = jump_lookup_pos(chain, f, num, tablearg, jump_backwards); cache.pos = f_pos; cache.id = chain->id; f->cache.raw_value = cache.raw_value; #else if (f->cache.id == chain->id) { /* Load pos after id */ atomic_thread_fence_acq(); return (f->cache.pos); } f_pos = jump_lookup_pos(chain, f, num, tablearg, jump_backwards); f->cache.pos = f_pos; /* Store id after pos */ atomic_thread_fence_rel(); f->cache.id = chain->id; #endif /* !__LP64__ */ return (f_pos); } #endif /* !LINEAR_SKIPTO */ #define TARG(k, f) IP_FW_ARG_TABLEARG(chain, k, f) /* * The main check routine for the firewall. * * All arguments are in args so we can modify them and return them * back to the caller. * * Parameters: * * args->m (in/out) The packet; we set to NULL when/if we nuke it. * Starts with the IP header. * args->L3offset Number of bytes bypassed if we came from L2. * e.g. often sizeof(eh) ** NOTYET ** * args->ifp Incoming or outgoing interface. * args->divert_rule (in/out) * Skip up to the first rule past this rule number; * upon return, non-zero port number for divert or tee. * * args->rule Pointer to the last matching rule (in/out) * args->next_hop Socket we are forwarding to (out). * args->next_hop6 IPv6 next hop we are forwarding to (out). * args->f_id Addresses grabbed from the packet (out) * args->rule.info a cookie depending on rule action * * Return value: * * IP_FW_PASS the packet must be accepted * IP_FW_DENY the packet must be dropped * IP_FW_DIVERT divert packet, port in m_tag * IP_FW_TEE tee packet, port in m_tag * IP_FW_DUMMYNET to dummynet, pipe in args->cookie * IP_FW_NETGRAPH into netgraph, cookie args->cookie * args->rule contains the matching rule, * args->rule.info has additional information. * */ int ipfw_chk(struct ip_fw_args *args) { /* * Local variables holding state while processing a packet: * * IMPORTANT NOTE: to speed up the processing of rules, there * are some assumption on the values of the variables, which * are documented here. Should you change them, please check * the implementation of the various instructions to make sure * that they still work. * * m | args->m Pointer to the mbuf, as received from the caller. * It may change if ipfw_chk() does an m_pullup, or if it * consumes the packet because it calls send_reject(). * XXX This has to change, so that ipfw_chk() never modifies * or consumes the buffer. * OR * args->mem Pointer to contigous memory chunk. * ip Is the beginning of the ip(4 or 6) header. * eh Ethernet header in case if input is Layer2. */ struct mbuf *m; struct ip *ip; struct ether_header *eh; /* * For rules which contain uid/gid or jail constraints, cache * a copy of the users credentials after the pcb lookup has been * executed. This will speed up the processing of rules with * these types of constraints, as well as decrease contention * on pcb related locks. */ #ifndef __FreeBSD__ struct bsd_ucred ucred_cache; #else struct ucred *ucred_cache = NULL; #endif int ucred_lookup = 0; int f_pos = 0; /* index of current rule in the array */ int retval = 0; struct ifnet *oif, *iif; /* * hlen The length of the IP header. */ u_int hlen = 0; /* hlen >0 means we have an IP pkt */ /* * offset The offset of a fragment. offset != 0 means that * we have a fragment at this offset of an IPv4 packet. * offset == 0 means that (if this is an IPv4 packet) * this is the first or only fragment. * For IPv6 offset|ip6f_mf == 0 means there is no Fragment Header * or there is a single packet fragment (fragment header added * without needed). We will treat a single packet fragment as if * there was no fragment header (or log/block depending on the * V_fw_permit_single_frag6 sysctl setting). */ u_short offset = 0; u_short ip6f_mf = 0; /* * Local copies of addresses. They are only valid if we have * an IP packet. * * proto The protocol. Set to 0 for non-ip packets, * or to the protocol read from the packet otherwise. * proto != 0 means that we have an IPv4 packet. * * src_port, dst_port port numbers, in HOST format. Only * valid for TCP and UDP packets. * * src_ip, dst_ip ip addresses, in NETWORK format. * Only valid for IPv4 packets. */ uint8_t proto; uint16_t src_port, dst_port; /* NOTE: host format */ struct in_addr src_ip, dst_ip; /* NOTE: network format */ int iplen = 0; int pktlen; struct ipfw_dyn_info dyn_info; struct ip_fw *q = NULL; struct ip_fw_chain *chain = &V_layer3_chain; /* * We store in ulp a pointer to the upper layer protocol header. * In the ipv4 case this is easy to determine from the header, * but for ipv6 we might have some additional headers in the middle. * ulp is NULL if not found. */ void *ulp = NULL; /* upper layer protocol pointer. */ /* XXX ipv6 variables */ int is_ipv6 = 0; #ifdef INET6 uint8_t icmp6_type = 0; #endif uint16_t ext_hd = 0; /* bits vector for extension header filtering */ /* end of ipv6 variables */ int is_ipv4 = 0; int done = 0; /* flag to exit the outer loop */ IPFW_RLOCK_TRACKER; bool mem; if ((mem = (args->flags & IPFW_ARGS_LENMASK))) { if (args->flags & IPFW_ARGS_ETHER) { eh = (struct ether_header *)args->mem; if (eh->ether_type == htons(ETHERTYPE_VLAN)) ip = (struct ip *) ((struct ether_vlan_header *)eh + 1); else ip = (struct ip *)(eh + 1); } else { eh = NULL; ip = (struct ip *)args->mem; } pktlen = IPFW_ARGS_LENGTH(args->flags); args->f_id.fib = args->ifp->if_fib; /* best guess */ } else { m = args->m; if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready)) return (IP_FW_PASS); /* accept */ if (args->flags & IPFW_ARGS_ETHER) { /* We need some amount of data to be contiguous. */ if (m->m_len < min(m->m_pkthdr.len, max_protohdr) && (args->m = m = m_pullup(m, min(m->m_pkthdr.len, max_protohdr))) == NULL) goto pullup_failed; eh = mtod(m, struct ether_header *); ip = (struct ip *)(eh + 1); } else { eh = NULL; ip = mtod(m, struct ip *); } pktlen = m->m_pkthdr.len; args->f_id.fib = M_GETFIB(m); /* mbuf not altered */ } dst_ip.s_addr = 0; /* make sure it is initialized */ src_ip.s_addr = 0; /* make sure it is initialized */ src_port = dst_port = 0; DYN_INFO_INIT(&dyn_info); /* * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous, * then it sets p to point at the offset "len" in the mbuf. WARNING: the * pointer might become stale after other pullups (but we never use it * this way). */ #define PULLUP_TO(_len, p, T) PULLUP_LEN(_len, p, sizeof(T)) #define EHLEN (eh != NULL ? ((char *)ip - (char *)eh) : 0) #define _PULLUP_LOCKED(_len, p, T, unlock) \ do { \ int x = (_len) + T + EHLEN; \ if (mem) { \ if (__predict_false(pktlen < x)) { \ unlock; \ goto pullup_failed; \ } \ p = (char *)args->mem + (_len) + EHLEN; \ } else { \ if (__predict_false((m)->m_len < x)) { \ args->m = m = m_pullup(m, x); \ if (m == NULL) { \ unlock; \ goto pullup_failed; \ } \ } \ p = mtod(m, char *) + (_len) + EHLEN; \ } \ } while (0) #define PULLUP_LEN(_len, p, T) _PULLUP_LOCKED(_len, p, T, ) #define PULLUP_LEN_LOCKED(_len, p, T) \ _PULLUP_LOCKED(_len, p, T, IPFW_PF_RUNLOCK(chain)); \ UPDATE_POINTERS() /* * In case pointers got stale after pullups, update them. */ #define UPDATE_POINTERS() \ do { \ if (!mem) { \ if (eh != NULL) { \ eh = mtod(m, struct ether_header *); \ ip = (struct ip *)(eh + 1); \ } else \ ip = mtod(m, struct ip *); \ args->m = m; \ } \ } while (0) /* Identify IP packets and fill up variables. */ if (pktlen >= sizeof(struct ip6_hdr) && (eh == NULL || eh->ether_type == htons(ETHERTYPE_IPV6)) && ip->ip_v == 6) { struct ip6_hdr *ip6 = (struct ip6_hdr *)ip; is_ipv6 = 1; args->flags |= IPFW_ARGS_IP6; hlen = sizeof(struct ip6_hdr); proto = ip6->ip6_nxt; /* Search extension headers to find upper layer protocols */ while (ulp == NULL && offset == 0) { switch (proto) { case IPPROTO_ICMPV6: PULLUP_TO(hlen, ulp, struct icmp6_hdr); #ifdef INET6 icmp6_type = ICMP6(ulp)->icmp6_type; #endif break; case IPPROTO_TCP: PULLUP_TO(hlen, ulp, struct tcphdr); dst_port = TCP(ulp)->th_dport; src_port = TCP(ulp)->th_sport; /* save flags for dynamic rules */ args->f_id._flags = TCP(ulp)->th_flags; break; case IPPROTO_SCTP: if (pktlen >= hlen + sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr) + offsetof(struct sctp_init, a_rwnd)) PULLUP_LEN(hlen, ulp, sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr) + offsetof(struct sctp_init, a_rwnd)); else if (pktlen >= hlen + sizeof(struct sctphdr)) PULLUP_LEN(hlen, ulp, pktlen - hlen); else PULLUP_LEN(hlen, ulp, sizeof(struct sctphdr)); src_port = SCTP(ulp)->src_port; dst_port = SCTP(ulp)->dest_port; break; case IPPROTO_UDP: case IPPROTO_UDPLITE: PULLUP_TO(hlen, ulp, struct udphdr); dst_port = UDP(ulp)->uh_dport; src_port = UDP(ulp)->uh_sport; break; case IPPROTO_HOPOPTS: /* RFC 2460 */ PULLUP_TO(hlen, ulp, struct ip6_hbh); ext_hd |= EXT_HOPOPTS; hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; ulp = NULL; break; case IPPROTO_ROUTING: /* RFC 2460 */ PULLUP_TO(hlen, ulp, struct ip6_rthdr); switch (((struct ip6_rthdr *)ulp)->ip6r_type) { case 0: ext_hd |= EXT_RTHDR0; break; case 2: ext_hd |= EXT_RTHDR2; break; default: if (V_fw_verbose) printf("IPFW2: IPV6 - Unknown " "Routing Header type(%d)\n", ((struct ip6_rthdr *) ulp)->ip6r_type); if (V_fw_deny_unknown_exthdrs) return (IP_FW_DENY); break; } ext_hd |= EXT_ROUTING; hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3; proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt; ulp = NULL; break; case IPPROTO_FRAGMENT: /* RFC 2460 */ PULLUP_TO(hlen, ulp, struct ip6_frag); ext_hd |= EXT_FRAGMENT; hlen += sizeof (struct ip6_frag); proto = ((struct ip6_frag *)ulp)->ip6f_nxt; offset = ((struct ip6_frag *)ulp)->ip6f_offlg & IP6F_OFF_MASK; ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg & IP6F_MORE_FRAG; if (V_fw_permit_single_frag6 == 0 && offset == 0 && ip6f_mf == 0) { if (V_fw_verbose) printf("IPFW2: IPV6 - Invalid " "Fragment Header\n"); if (V_fw_deny_unknown_exthdrs) return (IP_FW_DENY); break; } args->f_id.extra = ntohl(((struct ip6_frag *)ulp)->ip6f_ident); ulp = NULL; break; case IPPROTO_DSTOPTS: /* RFC 2460 */ PULLUP_TO(hlen, ulp, struct ip6_hbh); ext_hd |= EXT_DSTOPTS; hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3; proto = ((struct ip6_hbh *)ulp)->ip6h_nxt; ulp = NULL; break; case IPPROTO_AH: /* RFC 2402 */ PULLUP_TO(hlen, ulp, struct ip6_ext); ext_hd |= EXT_AH; hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2; proto = ((struct ip6_ext *)ulp)->ip6e_nxt; ulp = NULL; break; case IPPROTO_ESP: /* RFC 2406 */ PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */ /* Anything past Seq# is variable length and * data past this ext. header is encrypted. */ ext_hd |= EXT_ESP; break; case IPPROTO_NONE: /* RFC 2460 */ /* * Packet ends here, and IPv6 header has * already been pulled up. If ip6e_len!=0 * then octets must be ignored. */ ulp = ip; /* non-NULL to get out of loop. */ break; case IPPROTO_OSPFIGP: /* XXX OSPF header check? */ PULLUP_TO(hlen, ulp, struct ip6_ext); break; case IPPROTO_PIM: /* XXX PIM header check? */ PULLUP_TO(hlen, ulp, struct pim); break; case IPPROTO_GRE: /* RFC 1701 */ /* XXX GRE header check? */ PULLUP_TO(hlen, ulp, struct grehdr); break; case IPPROTO_CARP: PULLUP_TO(hlen, ulp, offsetof( struct carp_header, carp_counter)); if (CARP_ADVERTISEMENT != ((struct carp_header *)ulp)->carp_type) return (IP_FW_DENY); break; case IPPROTO_IPV6: /* RFC 2893 */ PULLUP_TO(hlen, ulp, struct ip6_hdr); break; case IPPROTO_IPV4: /* RFC 2893 */ PULLUP_TO(hlen, ulp, struct ip); break; case IPPROTO_PFSYNC: PULLUP_TO(hlen, ulp, struct pfsync_header); break; default: if (V_fw_verbose) printf("IPFW2: IPV6 - Unknown " "Extension Header(%d), ext_hd=%x\n", proto, ext_hd); if (V_fw_deny_unknown_exthdrs) return (IP_FW_DENY); PULLUP_TO(hlen, ulp, struct ip6_ext); break; } /*switch */ } UPDATE_POINTERS(); ip6 = (struct ip6_hdr *)ip; args->f_id.addr_type = 6; args->f_id.src_ip6 = ip6->ip6_src; args->f_id.dst_ip6 = ip6->ip6_dst; args->f_id.flow_id6 = ntohl(ip6->ip6_flow); iplen = ntohs(ip6->ip6_plen) + sizeof(*ip6); } else if (pktlen >= sizeof(struct ip) && (eh == NULL || eh->ether_type == htons(ETHERTYPE_IP)) && ip->ip_v == 4) { is_ipv4 = 1; args->flags |= IPFW_ARGS_IP4; hlen = ip->ip_hl << 2; /* * Collect parameters into local variables for faster * matching. */ proto = ip->ip_p; src_ip = ip->ip_src; dst_ip = ip->ip_dst; offset = ntohs(ip->ip_off) & IP_OFFMASK; iplen = ntohs(ip->ip_len); if (offset == 0) { switch (proto) { case IPPROTO_TCP: PULLUP_TO(hlen, ulp, struct tcphdr); dst_port = TCP(ulp)->th_dport; src_port = TCP(ulp)->th_sport; /* save flags for dynamic rules */ args->f_id._flags = TCP(ulp)->th_flags; break; case IPPROTO_SCTP: if (pktlen >= hlen + sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr) + offsetof(struct sctp_init, a_rwnd)) PULLUP_LEN(hlen, ulp, sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr) + offsetof(struct sctp_init, a_rwnd)); else if (pktlen >= hlen + sizeof(struct sctphdr)) PULLUP_LEN(hlen, ulp, pktlen - hlen); else PULLUP_LEN(hlen, ulp, sizeof(struct sctphdr)); src_port = SCTP(ulp)->src_port; dst_port = SCTP(ulp)->dest_port; break; case IPPROTO_UDP: case IPPROTO_UDPLITE: PULLUP_TO(hlen, ulp, struct udphdr); dst_port = UDP(ulp)->uh_dport; src_port = UDP(ulp)->uh_sport; break; case IPPROTO_ICMP: PULLUP_TO(hlen, ulp, struct icmphdr); //args->f_id.flags = ICMP(ulp)->icmp_type; break; default: break; } } else { if (offset == 1 && proto == IPPROTO_TCP) { /* RFC 3128 */ goto pullup_failed; } } UPDATE_POINTERS(); args->f_id.addr_type = 4; args->f_id.src_ip = ntohl(src_ip.s_addr); args->f_id.dst_ip = ntohl(dst_ip.s_addr); } else { proto = 0; dst_ip.s_addr = src_ip.s_addr = 0; args->f_id.addr_type = 1; /* XXX */ } #undef PULLUP_TO pktlen = iplen < pktlen ? iplen: pktlen; /* Properly initialize the rest of f_id */ args->f_id.proto = proto; args->f_id.src_port = src_port = ntohs(src_port); args->f_id.dst_port = dst_port = ntohs(dst_port); IPFW_PF_RLOCK(chain); if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */ IPFW_PF_RUNLOCK(chain); return (IP_FW_PASS); /* accept */ } if (args->flags & IPFW_ARGS_REF) { /* * Packet has already been tagged as a result of a previous * match on rule args->rule aka args->rule_id (PIPE, QUEUE, * REASS, NETGRAPH, DIVERT/TEE...) * Validate the slot and continue from the next one * if still present, otherwise do a lookup. */ f_pos = (args->rule.chain_id == chain->id) ? args->rule.slot : ipfw_find_rule(chain, args->rule.rulenum, args->rule.rule_id); } else { f_pos = 0; } if (args->flags & IPFW_ARGS_IN) { iif = args->ifp; oif = NULL; } else { MPASS(args->flags & IPFW_ARGS_OUT); iif = mem ? NULL : m_rcvif(m); oif = args->ifp; } /* * Now scan the rules, and parse microinstructions for each rule. * We have two nested loops and an inner switch. Sometimes we * need to break out of one or both loops, or re-enter one of * the loops with updated variables. Loop variables are: * * f_pos (outer loop) points to the current rule. * On output it points to the matching rule. * done (outer loop) is used as a flag to break the loop. * l (inner loop) residual length of current rule. * cmd points to the current microinstruction. * * We break the inner loop by setting l=0 and possibly * cmdlen=0 if we don't want to advance cmd. * We break the outer loop by setting done=1 * We can restart the inner loop by setting l>0 and f_pos, f, cmd * as needed. */ for (; f_pos < chain->n_rules; f_pos++) { ipfw_insn *cmd; uint32_t tablearg = 0; int l, cmdlen, skip_or; /* skip rest of OR block */ struct ip_fw *f; f = chain->map[f_pos]; if (V_set_disable & (1 << f->set) ) continue; skip_or = 0; for (l = f->cmd_len, cmd = f->cmd ; l > 0 ; l -= cmdlen, cmd += cmdlen) { int match; /* * check_body is a jump target used when we find a * CHECK_STATE, and need to jump to the body of * the target rule. */ /* check_body: */ cmdlen = F_LEN(cmd); /* * An OR block (insn_1 || .. || insn_n) has the * F_OR bit set in all but the last instruction. * The first match will set "skip_or", and cause * the following instructions to be skipped until * past the one with the F_OR bit clear. */ if (skip_or) { /* skip this instruction */ if ((cmd->len & F_OR) == 0) skip_or = 0; /* next one is good */ continue; } match = 0; /* set to 1 if we succeed */ switch (cmd->opcode) { /* * The first set of opcodes compares the packet's * fields with some pattern, setting 'match' if a * match is found. At the end of the loop there is * logic to deal with F_NOT and F_OR flags associated * with the opcode. */ case O_NOP: match = 1; break; case O_FORWARD_MAC: printf("ipfw: opcode %d unimplemented\n", cmd->opcode); break; case O_GID: case O_UID: case O_JAIL: /* * We only check offset == 0 && proto != 0, * as this ensures that we have a * packet with the ports info. */ if (offset != 0) break; if (proto == IPPROTO_TCP || proto == IPPROTO_UDP || proto == IPPROTO_UDPLITE) match = check_uidgid( (ipfw_insn_u32 *)cmd, args, &ucred_lookup, #ifdef __FreeBSD__ &ucred_cache); #else (void *)&ucred_cache); #endif break; case O_RECV: match = iface_match(iif, (ipfw_insn_if *)cmd, chain, &tablearg); break; case O_XMIT: match = iface_match(oif, (ipfw_insn_if *)cmd, chain, &tablearg); break; case O_VIA: match = iface_match(args->ifp, (ipfw_insn_if *)cmd, chain, &tablearg); break; case O_MACADDR2: if (args->flags & IPFW_ARGS_ETHER) { u_int32_t *want = (u_int32_t *) ((ipfw_insn_mac *)cmd)->addr; u_int32_t *mask = (u_int32_t *) ((ipfw_insn_mac *)cmd)->mask; u_int32_t *hdr = (u_int32_t *)eh; match = ( want[0] == (hdr[0] & mask[0]) && want[1] == (hdr[1] & mask[1]) && want[2] == (hdr[2] & mask[2]) ); } break; case O_MAC_TYPE: if (args->flags & IPFW_ARGS_ETHER) { u_int16_t *p = ((ipfw_insn_u16 *)cmd)->ports; int i; for (i = cmdlen - 1; !match && i>0; i--, p += 2) match = (ntohs(eh->ether_type) >= p[0] && ntohs(eh->ether_type) <= p[1]); } break; case O_FRAG: if (is_ipv4) { /* * Since flags_match() works with * uint8_t we pack ip_off into 8 bits. * For this match offset is a boolean. */ match = flags_match(cmd, ((ntohs(ip->ip_off) & ~IP_OFFMASK) >> 8) | (offset != 0)); } else { /* * Compatibility: historically bare * "frag" would match IPv6 fragments. */ match = (cmd->arg1 == 0x1 && (offset != 0)); } break; case O_IN: /* "out" is "not in" */ match = (oif == NULL); break; case O_LAYER2: match = (args->flags & IPFW_ARGS_ETHER); break; case O_DIVERTED: if ((args->flags & IPFW_ARGS_REF) == 0) break; /* * For diverted packets, args->rule.info * contains the divert port (in host format) * reason and direction. */ match = ((args->rule.info & IPFW_IS_MASK) == IPFW_IS_DIVERT) && ( ((args->rule.info & IPFW_INFO_IN) ? 1: 2) & cmd->arg1); break; case O_PROTO: /* * We do not allow an arg of 0 so the * check of "proto" only suffices. */ match = (proto == cmd->arg1); break; case O_IP_SRC: match = is_ipv4 && (((ipfw_insn_ip *)cmd)->addr.s_addr == src_ip.s_addr); break; case O_IP_DST_LOOKUP: { if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) { void *pkey; uint32_t vidx, key; uint16_t keylen = 0; /* zero if can't match the packet */ /* Determine lookup key type */ vidx = ((ipfw_insn_u32 *)cmd)->d[1]; switch (vidx) { case LOOKUP_DST_IP: case LOOKUP_SRC_IP: /* Need IP frame */ if (is_ipv6 == 0 && is_ipv4 == 0) break; if (vidx == LOOKUP_DST_IP) pkey = is_ipv6 ? (void *)&args->f_id.dst_ip6: (void *)&dst_ip; else pkey = is_ipv6 ? (void *)&args->f_id.src_ip6: (void *)&src_ip; keylen = is_ipv6 ? sizeof(struct in6_addr): sizeof(in_addr_t); break; case LOOKUP_DST_PORT: case LOOKUP_SRC_PORT: /* Need IP frame */ if (is_ipv6 == 0 && is_ipv4 == 0) break; /* Skip fragments */ if (offset != 0) break; /* Skip proto without ports */ if (proto != IPPROTO_TCP && proto != IPPROTO_UDP && proto != IPPROTO_UDPLITE && proto != IPPROTO_SCTP) break; key = vidx == LOOKUP_DST_PORT ? dst_port: src_port; pkey = &key; keylen = sizeof(key); break; case LOOKUP_UID: case LOOKUP_JAIL: check_uidgid( (ipfw_insn_u32 *)cmd, args, &ucred_lookup, &ucred_cache); key = vidx == LOOKUP_UID ? ucred_cache->cr_uid: ucred_cache->cr_prison->pr_id; pkey = &key; keylen = sizeof(key); break; case LOOKUP_DSCP: /* Need IP frame */ if (is_ipv6 == 0 && is_ipv4 == 0) break; if (is_ipv6) key = IPV6_DSCP( (struct ip6_hdr *)ip) >> 2; else key = ip->ip_tos >> 2; pkey = &key; keylen = sizeof(key); break; case LOOKUP_DST_MAC: case LOOKUP_SRC_MAC: /* Need ether frame */ if ((args->flags & IPFW_ARGS_ETHER) == 0) break; pkey = vidx == LOOKUP_DST_MAC ? eh->ether_dhost: eh->ether_shost; keylen = ETHER_ADDR_LEN; break; case LOOKUP_MARK: key = args->rule.pkt_mark; pkey = &key; keylen = sizeof(key); break; } if (keylen == 0) break; match = ipfw_lookup_table(chain, cmd->arg1, keylen, pkey, &vidx); if (!match) break; tablearg = vidx; break; } /* cmdlen =< F_INSN_SIZE(ipfw_insn_u32) */ /* FALLTHROUGH */ } case O_IP_SRC_LOOKUP: { void *pkey; uint32_t vidx; uint16_t keylen; if (is_ipv4) { keylen = sizeof(in_addr_t); if (cmd->opcode == O_IP_DST_LOOKUP) pkey = &dst_ip; else pkey = &src_ip; } else if (is_ipv6) { keylen = sizeof(struct in6_addr); if (cmd->opcode == O_IP_DST_LOOKUP) pkey = &args->f_id.dst_ip6; else pkey = &args->f_id.src_ip6; } else break; match = ipfw_lookup_table(chain, cmd->arg1, keylen, pkey, &vidx); if (!match) break; if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) { match = ((ipfw_insn_u32 *)cmd)->d[0] == TARG_VAL(chain, vidx, tag); if (!match) break; } tablearg = vidx; break; } case O_MAC_SRC_LOOKUP: case O_MAC_DST_LOOKUP: { void *pkey; uint32_t vidx; uint16_t keylen = ETHER_ADDR_LEN; /* Need ether frame */ if ((args->flags & IPFW_ARGS_ETHER) == 0) break; if (cmd->opcode == O_MAC_DST_LOOKUP) pkey = eh->ether_dhost; else pkey = eh->ether_shost; match = ipfw_lookup_table(chain, cmd->arg1, keylen, pkey, &vidx); if (!match) break; if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) { match = ((ipfw_insn_u32 *)cmd)->d[0] == TARG_VAL(chain, vidx, tag); if (!match) break; } tablearg = vidx; break; } case O_IP_FLOW_LOOKUP: { uint32_t v = 0; match = ipfw_lookup_table(chain, cmd->arg1, 0, &args->f_id, &v); if (!match) break; if (cmdlen == F_INSN_SIZE(ipfw_insn_u32)) match = ((ipfw_insn_u32 *)cmd)->d[0] == TARG_VAL(chain, v, tag); if (match) tablearg = v; } break; case O_IP_SRC_MASK: case O_IP_DST_MASK: if (is_ipv4) { uint32_t a = (cmd->opcode == O_IP_DST_MASK) ? dst_ip.s_addr : src_ip.s_addr; uint32_t *p = ((ipfw_insn_u32 *)cmd)->d; int i = cmdlen-1; for (; !match && i>0; i-= 2, p+= 2) match = (p[0] == (a & p[1])); } break; case O_IP_SRC_ME: if (is_ipv4) { match = in_localip(src_ip); break; } #ifdef INET6 /* FALLTHROUGH */ case O_IP6_SRC_ME: match = is_ipv6 && ipfw_localip6(&args->f_id.src_ip6); #endif break; case O_IP_DST_SET: case O_IP_SRC_SET: if (is_ipv4) { u_int32_t *d = (u_int32_t *)(cmd+1); u_int32_t addr = cmd->opcode == O_IP_DST_SET ? args->f_id.dst_ip : args->f_id.src_ip; if (addr < d[0]) break; addr -= d[0]; /* subtract base */ match = (addr < cmd->arg1) && ( d[ 1 + (addr>>5)] & (1<<(addr & 0x1f)) ); } break; case O_IP_DST: match = is_ipv4 && (((ipfw_insn_ip *)cmd)->addr.s_addr == dst_ip.s_addr); break; case O_IP_DST_ME: if (is_ipv4) { match = in_localip(dst_ip); break; } #ifdef INET6 /* FALLTHROUGH */ case O_IP6_DST_ME: match = is_ipv6 && ipfw_localip6(&args->f_id.dst_ip6); #endif break; case O_IP_SRCPORT: case O_IP_DSTPORT: /* * offset == 0 && proto != 0 is enough * to guarantee that we have a * packet with port info. */ if ((proto == IPPROTO_UDP || proto == IPPROTO_UDPLITE || proto == IPPROTO_TCP || proto == IPPROTO_SCTP) && offset == 0) { u_int16_t x = (cmd->opcode == O_IP_SRCPORT) ? src_port : dst_port ; u_int16_t *p = ((ipfw_insn_u16 *)cmd)->ports; int i; for (i = cmdlen - 1; !match && i>0; i--, p += 2) match = (x>=p[0] && x<=p[1]); } break; case O_ICMPTYPE: match = (offset == 0 && proto==IPPROTO_ICMP && icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) ); break; #ifdef INET6 case O_ICMP6TYPE: match = is_ipv6 && offset == 0 && proto==IPPROTO_ICMPV6 && icmp6type_match( ICMP6(ulp)->icmp6_type, (ipfw_insn_u32 *)cmd); break; #endif /* INET6 */ case O_IPOPT: match = (is_ipv4 && ipopts_match(ip, cmd) ); break; case O_IPVER: match = ((is_ipv4 || is_ipv6) && cmd->arg1 == ip->ip_v); break; case O_IPID: case O_IPTTL: if (!is_ipv4) break; case O_IPLEN: { /* only for IP packets */ uint16_t x; uint16_t *p; int i; if (cmd->opcode == O_IPLEN) x = iplen; else if (cmd->opcode == O_IPTTL) x = ip->ip_ttl; else /* must be IPID */ x = ntohs(ip->ip_id); if (cmdlen == 1) { match = (cmd->arg1 == x); break; } /* otherwise we have ranges */ p = ((ipfw_insn_u16 *)cmd)->ports; i = cmdlen - 1; for (; !match && i>0; i--, p += 2) match = (x >= p[0] && x <= p[1]); } break; case O_IPPRECEDENCE: match = (is_ipv4 && (cmd->arg1 == (ip->ip_tos & 0xe0)) ); break; case O_IPTOS: match = (is_ipv4 && flags_match(cmd, ip->ip_tos)); break; case O_DSCP: { uint32_t *p; uint16_t x; p = ((ipfw_insn_u32 *)cmd)->d; if (is_ipv4) x = ip->ip_tos >> 2; else if (is_ipv6) { x = IPV6_DSCP( (struct ip6_hdr *)ip) >> 2; x &= 0x3f; } else break; /* DSCP bitmask is stored as low_u32 high_u32 */ if (x >= 32) match = *(p + 1) & (1 << (x - 32)); else match = *p & (1 << x); } break; case O_TCPDATALEN: if (proto == IPPROTO_TCP && offset == 0) { struct tcphdr *tcp; uint16_t x; uint16_t *p; int i; #ifdef INET6 if (is_ipv6) { struct ip6_hdr *ip6; ip6 = (struct ip6_hdr *)ip; if (ip6->ip6_plen == 0) { /* * Jumbo payload is not * supported by this * opcode. */ break; } x = iplen - hlen; } else #endif /* INET6 */ x = iplen - (ip->ip_hl << 2); tcp = TCP(ulp); x -= tcp->th_off << 2; if (cmdlen == 1) { match = (cmd->arg1 == x); break; } /* otherwise we have ranges */ p = ((ipfw_insn_u16 *)cmd)->ports; i = cmdlen - 1; for (; !match && i>0; i--, p += 2) match = (x >= p[0] && x <= p[1]); } break; case O_TCPFLAGS: match = (proto == IPPROTO_TCP && offset == 0 && flags_match(cmd, TCP(ulp)->th_flags)); break; case O_TCPOPTS: if (proto == IPPROTO_TCP && offset == 0 && ulp){ PULLUP_LEN_LOCKED(hlen, ulp, (TCP(ulp)->th_off << 2)); match = tcpopts_match(TCP(ulp), cmd); } break; case O_TCPSEQ: match = (proto == IPPROTO_TCP && offset == 0 && ((ipfw_insn_u32 *)cmd)->d[0] == TCP(ulp)->th_seq); break; case O_TCPACK: match = (proto == IPPROTO_TCP && offset == 0 && ((ipfw_insn_u32 *)cmd)->d[0] == TCP(ulp)->th_ack); break; case O_TCPMSS: if (proto == IPPROTO_TCP && (args->f_id._flags & TH_SYN) != 0 && ulp != NULL) { uint16_t mss, *p; int i; PULLUP_LEN_LOCKED(hlen, ulp, (TCP(ulp)->th_off << 2)); if ((tcpopts_parse(TCP(ulp), &mss) & IP_FW_TCPOPT_MSS) == 0) break; if (cmdlen == 1) { match = (cmd->arg1 == mss); break; } /* Otherwise we have ranges. */ p = ((ipfw_insn_u16 *)cmd)->ports; i = cmdlen - 1; for (; !match && i > 0; i--, p += 2) match = (mss >= p[0] && mss <= p[1]); } break; case O_TCPWIN: if (proto == IPPROTO_TCP && offset == 0) { uint16_t x; uint16_t *p; int i; x = ntohs(TCP(ulp)->th_win); if (cmdlen == 1) { match = (cmd->arg1 == x); break; } /* Otherwise we have ranges. */ p = ((ipfw_insn_u16 *)cmd)->ports; i = cmdlen - 1; for (; !match && i > 0; i--, p += 2) match = (x >= p[0] && x <= p[1]); } break; case O_ESTAB: /* reject packets which have SYN only */ /* XXX should i also check for TH_ACK ? */ match = (proto == IPPROTO_TCP && offset == 0 && (TCP(ulp)->th_flags & (TH_RST | TH_ACK | TH_SYN)) != TH_SYN); break; case O_ALTQ: { struct pf_mtag *at; struct m_tag *mtag; ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd; /* * ALTQ uses mbuf tags from another * packet filtering system - pf(4). * We allocate a tag in its format * and fill it in, pretending to be pf(4). */ match = 1; at = pf_find_mtag(m); if (at != NULL && at->qid != 0) break; mtag = m_tag_get(PACKET_TAG_PF, sizeof(struct pf_mtag), M_NOWAIT | M_ZERO); if (mtag == NULL) { /* * Let the packet fall back to the * default ALTQ. */ break; } m_tag_prepend(m, mtag); at = (struct pf_mtag *)(mtag + 1); at->qid = altq->qid; at->hdr = ip; break; } case O_LOG: ipfw_log(chain, f, hlen, args, offset | ip6f_mf, tablearg, ip); match = 1; break; case O_PROB: match = (random()<((ipfw_insn_u32 *)cmd)->d[0]); break; case O_VERREVPATH: /* Outgoing packets automatically pass/match */ match = (args->flags & IPFW_ARGS_OUT || ( #ifdef INET6 is_ipv6 ? verify_path6(&(args->f_id.src_ip6), iif, args->f_id.fib) : #endif verify_path(src_ip, iif, args->f_id.fib))); break; case O_VERSRCREACH: /* Outgoing packets automatically pass/match */ match = (hlen > 0 && ((oif != NULL) || ( #ifdef INET6 is_ipv6 ? verify_path6(&(args->f_id.src_ip6), NULL, args->f_id.fib) : #endif verify_path(src_ip, NULL, args->f_id.fib)))); break; case O_ANTISPOOF: /* Outgoing packets automatically pass/match */ if (oif == NULL && hlen > 0 && ( (is_ipv4 && in_localaddr(src_ip)) #ifdef INET6 || (is_ipv6 && in6_localaddr(&(args->f_id.src_ip6))) #endif )) match = #ifdef INET6 is_ipv6 ? verify_path6( &(args->f_id.src_ip6), iif, args->f_id.fib) : #endif verify_path(src_ip, iif, args->f_id.fib); else match = 1; break; case O_IPSEC: match = (m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL); /* otherwise no match */ break; #ifdef INET6 case O_IP6_SRC: match = is_ipv6 && IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6, &((ipfw_insn_ip6 *)cmd)->addr6); break; case O_IP6_DST: match = is_ipv6 && IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6, &((ipfw_insn_ip6 *)cmd)->addr6); break; case O_IP6_SRC_MASK: case O_IP6_DST_MASK: if (is_ipv6) { int i = cmdlen - 1; struct in6_addr p; struct in6_addr *d = &((ipfw_insn_ip6 *)cmd)->addr6; for (; !match && i > 0; d += 2, i -= F_INSN_SIZE(struct in6_addr) * 2) { p = (cmd->opcode == O_IP6_SRC_MASK) ? args->f_id.src_ip6: args->f_id.dst_ip6; APPLY_MASK(&p, &d[1]); match = IN6_ARE_ADDR_EQUAL(&d[0], &p); } } break; case O_FLOW6ID: match = is_ipv6 && flow6id_match(args->f_id.flow_id6, (ipfw_insn_u32 *) cmd); break; case O_EXT_HDR: match = is_ipv6 && (ext_hd & ((ipfw_insn *) cmd)->arg1); break; case O_IP6: match = is_ipv6; break; #endif case O_IP4: match = is_ipv4; break; case O_TAG: { struct m_tag *mtag; uint32_t tag = TARG(cmd->arg1, tag); /* Packet is already tagged with this tag? */ mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL); /* We have `untag' action when F_NOT flag is * present. And we must remove this mtag from * mbuf and reset `match' to zero (`match' will * be inversed later). * Otherwise we should allocate new mtag and * push it into mbuf. */ if (cmd->len & F_NOT) { /* `untag' action */ if (mtag != NULL) m_tag_delete(m, mtag); match = 0; } else { if (mtag == NULL) { mtag = m_tag_alloc( MTAG_IPFW, tag, 0, M_NOWAIT); if (mtag != NULL) m_tag_prepend(m, mtag); } match = 1; } break; } case O_FIB: /* try match the specified fib */ if (args->f_id.fib == cmd->arg1) match = 1; break; case O_SOCKARG: { #ifndef USERSPACE /* not supported in userspace */ struct inpcb *inp = args->inp; struct inpcbinfo *pi; bool inp_locked = false; if (proto == IPPROTO_TCP) pi = &V_tcbinfo; else if (proto == IPPROTO_UDP) pi = &V_udbinfo; else if (proto == IPPROTO_UDPLITE) pi = &V_ulitecbinfo; else break; /* * XXXRW: so_user_cookie should almost * certainly be inp_user_cookie? */ /* * For incoming packet lookup the inpcb * using the src/dest ip/port tuple. */ if (is_ipv4 && inp == NULL) { inp = in_pcblookup(pi, src_ip, htons(src_port), dst_ip, htons(dst_port), INPLOOKUP_RLOCKPCB, NULL); inp_locked = true; } #ifdef INET6 if (is_ipv6 && inp == NULL) { inp = in6_pcblookup(pi, &args->f_id.src_ip6, htons(src_port), &args->f_id.dst_ip6, htons(dst_port), INPLOOKUP_RLOCKPCB, NULL); inp_locked = true; } #endif /* INET6 */ if (inp != NULL) { if (inp->inp_socket) { tablearg = inp->inp_socket->so_user_cookie; if (tablearg) match = 1; } if (inp_locked) INP_RUNLOCK(inp); } #endif /* !USERSPACE */ break; } case O_TAGGED: { struct m_tag *mtag; uint32_t tag = TARG(cmd->arg1, tag); if (cmdlen == 1) { match = m_tag_locate(m, MTAG_IPFW, tag, NULL) != NULL; break; } /* we have ranges */ for (mtag = m_tag_first(m); mtag != NULL && !match; mtag = m_tag_next(m, mtag)) { uint16_t *p; int i; if (mtag->m_tag_cookie != MTAG_IPFW) continue; p = ((ipfw_insn_u16 *)cmd)->ports; i = cmdlen - 1; for(; !match && i > 0; i--, p += 2) match = mtag->m_tag_id >= p[0] && mtag->m_tag_id <= p[1]; } break; } case O_MARK: { uint32_t mark; if (cmd->arg1 == IP_FW_TARG) mark = TARG_VAL(chain, tablearg, mark); else mark = ((ipfw_insn_u32 *)cmd)->d[0]; match = (args->rule.pkt_mark & ((ipfw_insn_u32 *)cmd)->d[1]) == (mark & ((ipfw_insn_u32 *)cmd)->d[1]); break; } /* * The second set of opcodes represents 'actions', * i.e. the terminal part of a rule once the packet * matches all previous patterns. * Typically there is only one action for each rule, * and the opcode is stored at the end of the rule * (but there are exceptions -- see below). * * In general, here we set retval and terminate the * outer loop (would be a 'break 3' in some language, * but we need to set l=0, done=1) * * Exceptions: * O_COUNT and O_SKIPTO actions: * instead of terminating, we jump to the next rule * (setting l=0), or to the SKIPTO target (setting * f/f_len, cmd and l as needed), respectively. * * O_TAG, O_LOG and O_ALTQ action parameters: * perform some action and set match = 1; * * O_LIMIT and O_KEEP_STATE: these opcodes are * not real 'actions', and are stored right * before the 'action' part of the rule (one * exception is O_SKIP_ACTION which could be * between these opcodes and 'action' one). * These opcodes try to install an entry in the * state tables; if successful, we continue with * the next opcode (match=1; break;), otherwise * the packet must be dropped (set retval, * break loops with l=0, done=1) * * O_PROBE_STATE and O_CHECK_STATE: these opcodes * cause a lookup of the state table, and a jump * to the 'action' part of the parent rule * if an entry is found, or * (CHECK_STATE only) a jump to the next rule if * the entry is not found. * The result of the lookup is cached so that * further instances of these opcodes become NOPs. * The jump to the next rule is done by setting * l=0, cmdlen=0. * * O_SKIP_ACTION: this opcode is not a real 'action' * either, and is stored right before the 'action' * part of the rule, right after the O_KEEP_STATE * opcode. It causes match failure so the real * 'action' could be executed only if the rule * is checked via dynamic rule from the state * table, as in such case execution starts * from the true 'action' opcode directly. * */ case O_LIMIT: case O_KEEP_STATE: if (ipfw_dyn_install_state(chain, f, (ipfw_insn_limit *)cmd, args, ulp, pktlen, &dyn_info, tablearg)) { /* error or limit violation */ retval = IP_FW_DENY; l = 0; /* exit inner loop */ done = 1; /* exit outer loop */ } match = 1; break; case O_PROBE_STATE: case O_CHECK_STATE: /* * dynamic rules are checked at the first * keep-state or check-state occurrence, * with the result being stored in dyn_info. * The compiler introduces a PROBE_STATE * instruction for us when we have a * KEEP_STATE (because PROBE_STATE needs * to be run first). */ if (DYN_LOOKUP_NEEDED(&dyn_info, cmd) && (q = ipfw_dyn_lookup_state(args, ulp, pktlen, cmd, &dyn_info)) != NULL) { /* * Found dynamic entry, jump to the * 'action' part of the parent rule * by setting f, cmd, l and clearing * cmdlen. */ f = q; f_pos = dyn_info.f_pos; cmd = ACTION_PTR(f); l = f->cmd_len - f->act_ofs; cmdlen = 0; continue; } /* * Dynamic entry not found. If CHECK_STATE, * skip to next rule, if PROBE_STATE just * ignore and continue with next opcode. */ if (cmd->opcode == O_CHECK_STATE) l = 0; /* exit inner loop */ match = 1; break; case O_SKIP_ACTION: match = 0; /* skip to the next rule */ l = 0; /* exit inner loop */ break; case O_ACCEPT: retval = 0; /* accept */ l = 0; /* exit inner loop */ done = 1; /* exit outer loop */ break; case O_PIPE: case O_QUEUE: set_match(args, f_pos, chain); args->rule.info = TARG(cmd->arg1, pipe); if (cmd->opcode == O_PIPE) args->rule.info |= IPFW_IS_PIPE; if (V_fw_one_pass) args->rule.info |= IPFW_ONEPASS; retval = IP_FW_DUMMYNET; l = 0; /* exit inner loop */ done = 1; /* exit outer loop */ break; case O_DIVERT: case O_TEE: if (args->flags & IPFW_ARGS_ETHER) break; /* not on layer 2 */ /* otherwise this is terminal */ l = 0; /* exit inner loop */ done = 1; /* exit outer loop */ retval = (cmd->opcode == O_DIVERT) ? IP_FW_DIVERT : IP_FW_TEE; set_match(args, f_pos, chain); args->rule.info = TARG(cmd->arg1, divert); break; case O_COUNT: IPFW_INC_RULE_COUNTER(f, pktlen); l = 0; /* exit inner loop */ break; case O_SKIPTO: IPFW_INC_RULE_COUNTER(f, pktlen); f_pos = JUMP(chain, f, cmd->arg1, tablearg, 0); /* * Skip disabled rules, and re-enter * the inner loop with the correct * f_pos, f, l and cmd. * Also clear cmdlen and skip_or */ for (; f_pos < chain->n_rules - 1 && (V_set_disable & (1 << chain->map[f_pos]->set)); f_pos++) ; /* Re-enter the inner loop at the skipto rule. */ f = chain->map[f_pos]; l = f->cmd_len; cmd = f->cmd; match = 1; cmdlen = 0; skip_or = 0; continue; break; /* not reached */ case O_CALLRETURN: { /* * Implementation of `subroutine' call/return, * in the stack carried in an mbuf tag. This * is different from `skipto' in that any call * address is possible (`skipto' must prevent * backward jumps to avoid endless loops). * We have `return' action when F_NOT flag is * present. The `m_tag_id' field is used as * stack pointer. */ struct m_tag *mtag; uint16_t jmpto, *stack; #define IS_CALL ((cmd->len & F_NOT) == 0) #define IS_RETURN ((cmd->len & F_NOT) != 0) /* * Hand-rolled version of m_tag_locate() with * wildcard `type'. * If not already tagged, allocate new tag. */ mtag = m_tag_first(m); while (mtag != NULL) { if (mtag->m_tag_cookie == MTAG_IPFW_CALL) break; mtag = m_tag_next(m, mtag); } if (mtag == NULL && IS_CALL) { mtag = m_tag_alloc(MTAG_IPFW_CALL, 0, IPFW_CALLSTACK_SIZE * sizeof(uint16_t), M_NOWAIT); if (mtag != NULL) m_tag_prepend(m, mtag); } /* * On error both `call' and `return' just * continue with next rule. */ if (IS_RETURN && (mtag == NULL || mtag->m_tag_id == 0)) { l = 0; /* exit inner loop */ break; } if (IS_CALL && (mtag == NULL || mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) { printf("ipfw: call stack error, " "go to next rule\n"); l = 0; /* exit inner loop */ break; } IPFW_INC_RULE_COUNTER(f, pktlen); stack = (uint16_t *)(mtag + 1); /* * The `call' action may use cached f_pos * (in f->next_rule), whose version is written * in f->next_rule. * The `return' action, however, doesn't have * fixed jump address in cmd->arg1 and can't use * cache. */ if (IS_CALL) { stack[mtag->m_tag_id] = f->rulenum; mtag->m_tag_id++; f_pos = JUMP(chain, f, cmd->arg1, tablearg, 1); } else { /* `return' action */ mtag->m_tag_id--; jmpto = stack[mtag->m_tag_id] + 1; f_pos = ipfw_find_rule(chain, jmpto, 0); } /* * Skip disabled rules, and re-enter * the inner loop with the correct * f_pos, f, l and cmd. * Also clear cmdlen and skip_or */ for (; f_pos < chain->n_rules - 1 && (V_set_disable & (1 << chain->map[f_pos]->set)); f_pos++) ; /* Re-enter the inner loop at the dest rule. */ f = chain->map[f_pos]; l = f->cmd_len; cmd = f->cmd; cmdlen = 0; skip_or = 0; continue; break; /* NOTREACHED */ } #undef IS_CALL #undef IS_RETURN case O_REJECT: /* * Drop the packet and send a reject notice * if the packet is not ICMP (or is an ICMP * query), and it is not multicast/broadcast. */ if (hlen > 0 && is_ipv4 && offset == 0 && (proto != IPPROTO_ICMP || is_icmp_query(ICMP(ulp))) && !(m->m_flags & (M_BCAST|M_MCAST)) && !IN_MULTICAST(ntohl(dst_ip.s_addr))) { send_reject(args, cmd, iplen, ip); m = args->m; } /* FALLTHROUGH */ #ifdef INET6 case O_UNREACH6: if (hlen > 0 && is_ipv6 && ((offset & IP6F_OFF_MASK) == 0) && (proto != IPPROTO_ICMPV6 || (is_icmp6_query(icmp6_type) == 1)) && !(m->m_flags & (M_BCAST|M_MCAST)) && !IN6_IS_ADDR_MULTICAST( &args->f_id.dst_ip6)) { send_reject6(args, cmd->opcode == O_REJECT ? map_icmp_unreach(cmd->arg1): cmd->arg1, hlen, (struct ip6_hdr *)ip); m = args->m; } /* FALLTHROUGH */ #endif case O_DENY: retval = IP_FW_DENY; l = 0; /* exit inner loop */ done = 1; /* exit outer loop */ break; case O_FORWARD_IP: if (args->flags & IPFW_ARGS_ETHER) break; /* not valid on layer2 pkts */ if (q != f || dyn_info.direction == MATCH_FORWARD) { struct sockaddr_in *sa; sa = &(((ipfw_insn_sa *)cmd)->sa); if (sa->sin_addr.s_addr == INADDR_ANY) { #ifdef INET6 /* * We use O_FORWARD_IP opcode for * fwd rule with tablearg, but tables * now support IPv6 addresses. And * when we are inspecting IPv6 packet, * we can use nh6 field from * table_value as next_hop6 address. */ if (is_ipv6) { struct ip_fw_nh6 *nh6; args->flags |= IPFW_ARGS_NH6; nh6 = &args->hopstore6; nh6->sin6_addr = TARG_VAL( chain, tablearg, nh6); nh6->sin6_port = sa->sin_port; nh6->sin6_scope_id = TARG_VAL( chain, tablearg, zoneid); } else #endif { args->flags |= IPFW_ARGS_NH4; args->hopstore.sin_port = sa->sin_port; sa = &args->hopstore; sa->sin_family = AF_INET; sa->sin_len = sizeof(*sa); sa->sin_addr.s_addr = htonl( TARG_VAL(chain, tablearg, nh4)); } } else { args->flags |= IPFW_ARGS_NH4PTR; args->next_hop = sa; } } retval = IP_FW_PASS; l = 0; /* exit inner loop */ done = 1; /* exit outer loop */ break; #ifdef INET6 case O_FORWARD_IP6: if (args->flags & IPFW_ARGS_ETHER) break; /* not valid on layer2 pkts */ if (q != f || dyn_info.direction == MATCH_FORWARD) { struct sockaddr_in6 *sin6; sin6 = &(((ipfw_insn_sa6 *)cmd)->sa); args->flags |= IPFW_ARGS_NH6PTR; args->next_hop6 = sin6; } retval = IP_FW_PASS; l = 0; /* exit inner loop */ done = 1; /* exit outer loop */ break; #endif case O_NETGRAPH: case O_NGTEE: set_match(args, f_pos, chain); args->rule.info = TARG(cmd->arg1, netgraph); if (V_fw_one_pass) args->rule.info |= IPFW_ONEPASS; retval = (cmd->opcode == O_NETGRAPH) ? IP_FW_NETGRAPH : IP_FW_NGTEE; l = 0; /* exit inner loop */ done = 1; /* exit outer loop */ break; case O_SETFIB: { uint32_t fib; IPFW_INC_RULE_COUNTER(f, pktlen); fib = TARG(cmd->arg1, fib) & 0x7FFF; if (fib >= rt_numfibs) fib = 0; M_SETFIB(m, fib); args->f_id.fib = fib; /* XXX */ l = 0; /* exit inner loop */ break; } case O_SETDSCP: { uint16_t code; code = TARG(cmd->arg1, dscp) & 0x3F; l = 0; /* exit inner loop */ if (is_ipv4) { uint16_t old; old = *(uint16_t *)ip; ip->ip_tos = (code << 2) | (ip->ip_tos & 0x03); ip->ip_sum = cksum_adjust(ip->ip_sum, old, *(uint16_t *)ip); } else if (is_ipv6) { /* update cached value */ args->f_id.flow_id6 = ntohl(*(uint32_t *)ip) & ~0x0FC00000; args->f_id.flow_id6 |= code << 22; *((uint32_t *)ip) = htonl(args->f_id.flow_id6); } else break; IPFW_INC_RULE_COUNTER(f, pktlen); break; } case O_NAT: l = 0; /* exit inner loop */ done = 1; /* exit outer loop */ /* * Ensure that we do not invoke NAT handler for * non IPv4 packets. Libalias expects only IPv4. */ if (!is_ipv4 || !IPFW_NAT_LOADED) { retval = IP_FW_DENY; break; } struct cfg_nat *t; int nat_id; args->rule.info = 0; set_match(args, f_pos, chain); /* Check if this is 'global' nat rule */ if (cmd->arg1 == IP_FW_NAT44_GLOBAL) { retval = ipfw_nat_ptr(args, NULL, m); break; } t = ((ipfw_insn_nat *)cmd)->nat; if (t == NULL) { nat_id = TARG(cmd->arg1, nat); t = (*lookup_nat_ptr)(&chain->nat, nat_id); if (t == NULL) { retval = IP_FW_DENY; break; } if (cmd->arg1 != IP_FW_TARG) ((ipfw_insn_nat *)cmd)->nat = t; } retval = ipfw_nat_ptr(args, t, m); break; case O_REASS: { int ip_off; l = 0; /* in any case exit inner loop */ if (is_ipv6) /* IPv6 is not supported yet */ break; IPFW_INC_RULE_COUNTER(f, pktlen); ip_off = ntohs(ip->ip_off); /* if not fragmented, go to next rule */ if ((ip_off & (IP_MF | IP_OFFMASK)) == 0) break; args->m = m = ip_reass(m); /* * do IP header checksum fixup. */ if (m == NULL) { /* fragment got swallowed */ retval = IP_FW_DENY; } else { /* good, packet complete */ int hlen; ip = mtod(m, struct ip *); hlen = ip->ip_hl << 2; ip->ip_sum = 0; if (hlen == sizeof(struct ip)) ip->ip_sum = in_cksum_hdr(ip); else ip->ip_sum = in_cksum(m, hlen); retval = IP_FW_REASS; args->rule.info = 0; set_match(args, f_pos, chain); } done = 1; /* exit outer loop */ break; } case O_SETMARK: { l = 0; /* exit inner loop */ args->rule.pkt_mark = ( (cmd->arg1 == IP_FW_TARG) ? TARG_VAL(chain, tablearg, mark) : ((ipfw_insn_u32 *)cmd)->d[0]); IPFW_INC_RULE_COUNTER(f, pktlen); break; } case O_EXTERNAL_ACTION: l = 0; /* in any case exit inner loop */ retval = ipfw_run_eaction(chain, args, cmd, &done); /* * If both @retval and @done are zero, * consider this as rule matching and * update counters. */ if (retval == 0 && done == 0) { IPFW_INC_RULE_COUNTER(f, pktlen); /* * Reset the result of the last * dynamic state lookup. * External action can change * @args content, and it may be * used for new state lookup later. */ DYN_INFO_INIT(&dyn_info); } break; default: panic("-- unknown opcode %d\n", cmd->opcode); } /* end of switch() on opcodes */ /* * if we get here with l=0, then match is irrelevant. */ if (cmd->len & F_NOT) match = !match; if (match) { if (cmd->len & F_OR) skip_or = 1; } else { if (!(cmd->len & F_OR)) /* not an OR block, */ break; /* try next rule */ } } /* end of inner loop, scan opcodes */ #undef PULLUP_LEN #undef PULLUP_LEN_LOCKED if (done) break; /* next_rule:; */ /* try next rule */ } /* end of outer for, scan rules */ if (done) { struct ip_fw *rule = chain->map[f_pos]; /* Update statistics */ IPFW_INC_RULE_COUNTER(rule, pktlen); IPFW_PROBE(rule__matched, retval, is_ipv4 ? AF_INET : AF_INET6, is_ipv4 ? (uintptr_t)&src_ip : (uintptr_t)&args->f_id.src_ip6, is_ipv4 ? (uintptr_t)&dst_ip : (uintptr_t)&args->f_id.dst_ip6, args, rule); } else { retval = IP_FW_DENY; printf("ipfw: ouch!, skip past end of rules, denying packet\n"); } IPFW_PF_RUNLOCK(chain); #ifdef __FreeBSD__ if (ucred_cache != NULL) crfree(ucred_cache); #endif return (retval); pullup_failed: if (V_fw_verbose) printf("ipfw: pullup failed\n"); return (IP_FW_DENY); } /* * Set maximum number of tables that can be used in given VNET ipfw instance. */ #ifdef SYSCTL_NODE static int sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS) { int error; unsigned int ntables; ntables = V_fw_tables_max; error = sysctl_handle_int(oidp, &ntables, 0, req); /* Read operation or some error */ if ((error != 0) || (req->newptr == NULL)) return (error); return (ipfw_resize_tables(&V_layer3_chain, ntables)); } /* * Switches table namespace between global and per-set. */ static int sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS) { int error; unsigned int sets; sets = V_fw_tables_sets; error = sysctl_handle_int(oidp, &sets, 0, req); /* Read operation or some error */ if ((error != 0) || (req->newptr == NULL)) return (error); return (ipfw_switch_tables_namespace(&V_layer3_chain, sets)); } #endif /* * Module and VNET glue */ /* * Stuff that must be initialised only on boot or module load */ static int ipfw_init(void) { int error = 0; /* * Only print out this stuff the first time around, * when called from the sysinit code. */ printf("ipfw2 " #ifdef INET6 "(+ipv6) " #endif "initialized, divert %s, nat %s, " "default to %s, logging ", #ifdef IPDIVERT "enabled", #else "loadable", #endif #ifdef IPFIREWALL_NAT "enabled", #else "loadable", #endif default_to_accept ? "accept" : "deny"); /* * Note: V_xxx variables can be accessed here but the vnet specific * initializer may not have been called yet for the VIMAGE case. * Tuneables will have been processed. We will print out values for * the default vnet. * XXX This should all be rationalized AFTER 8.0 */ if (V_fw_verbose == 0) printf("disabled\n"); else if (V_verbose_limit == 0) printf("unlimited\n"); else printf("limited to %d packets/entry by default\n", V_verbose_limit); /* Check user-supplied table count for validness */ if (default_fw_tables > IPFW_TABLES_MAX) default_fw_tables = IPFW_TABLES_MAX; ipfw_init_sopt_handler(); ipfw_init_obj_rewriter(); ipfw_iface_init(); return (error); } /* * Called for the removal of the last instance only on module unload. */ static void ipfw_destroy(void) { ipfw_iface_destroy(); ipfw_destroy_sopt_handler(); ipfw_destroy_obj_rewriter(); printf("IP firewall unloaded\n"); } /* * Stuff that must be initialized for every instance * (including the first of course). */ static int vnet_ipfw_init(const void *unused) { int error, first; struct ip_fw *rule = NULL; struct ip_fw_chain *chain; chain = &V_layer3_chain; first = IS_DEFAULT_VNET(curvnet) ? 1 : 0; /* First set up some values that are compile time options */ V_autoinc_step = 100; /* bounded to 1..1000 in add_rule() */ V_fw_deny_unknown_exthdrs = 1; #ifdef IPFIREWALL_VERBOSE V_fw_verbose = 1; #endif #ifdef IPFIREWALL_VERBOSE_LIMIT V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT; #endif #ifdef IPFIREWALL_NAT LIST_INIT(&chain->nat); #endif /* Init shared services hash table */ ipfw_init_srv(chain); ipfw_init_counters(); /* Set initial number of tables */ V_fw_tables_max = default_fw_tables; error = ipfw_init_tables(chain, first); if (error) { printf("ipfw2: setting up tables failed\n"); free(chain->map, M_IPFW); free(rule, M_IPFW); return (ENOSPC); } IPFW_LOCK_INIT(chain); /* fill and insert the default rule */ rule = ipfw_alloc_rule(chain, sizeof(struct ip_fw)); rule->flags |= IPFW_RULE_NOOPT; rule->cmd_len = 1; rule->cmd[0].len = 1; rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY; chain->default_rule = rule; ipfw_add_protected_rule(chain, rule, 0); ipfw_dyn_init(chain); ipfw_eaction_init(chain, first); #ifdef LINEAR_SKIPTO ipfw_init_skipto_cache(chain); #endif ipfw_bpf_init(first); /* First set up some values that are compile time options */ V_ipfw_vnet_ready = 1; /* Open for business */ /* * Hook the sockopt handler and pfil hooks for ipv4 and ipv6. * Even if the latter two fail we still keep the module alive * because the sockopt and layer2 paths are still useful. * ipfw[6]_hook return 0 on success, ENOENT on failure, * so we can ignore the exact return value and just set a flag. * * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so * changes in the underlying (per-vnet) variables trigger * immediate hook()/unhook() calls. * In layer2 we have the same behaviour, except that V_ether_ipfw * is checked on each packet because there are no pfil hooks. */ V_ip_fw_ctl_ptr = ipfw_ctl3; error = ipfw_attach_hooks(); return (error); } /* * Called for the removal of each instance. */ static int vnet_ipfw_uninit(const void *unused) { struct ip_fw *reap; struct ip_fw_chain *chain = &V_layer3_chain; int i, last; V_ipfw_vnet_ready = 0; /* tell new callers to go away */ /* * disconnect from ipv4, ipv6, layer2 and sockopt. * Then grab, release and grab again the WLOCK so we make * sure the update is propagated and nobody will be in. */ ipfw_detach_hooks(); V_ip_fw_ctl_ptr = NULL; last = IS_DEFAULT_VNET(curvnet) ? 1 : 0; IPFW_UH_WLOCK(chain); IPFW_UH_WUNLOCK(chain); ipfw_dyn_uninit(0); /* run the callout_drain */ IPFW_UH_WLOCK(chain); reap = NULL; IPFW_WLOCK(chain); for (i = 0; i < chain->n_rules; i++) ipfw_reap_add(chain, &reap, chain->map[i]); free(chain->map, M_IPFW); #ifdef LINEAR_SKIPTO ipfw_destroy_skipto_cache(chain); #endif IPFW_WUNLOCK(chain); IPFW_UH_WUNLOCK(chain); ipfw_destroy_tables(chain, last); ipfw_eaction_uninit(chain, last); if (reap != NULL) ipfw_reap_rules(reap); vnet_ipfw_iface_destroy(chain); ipfw_destroy_srv(chain); IPFW_LOCK_DESTROY(chain); ipfw_dyn_uninit(1); /* free the remaining parts */ ipfw_destroy_counters(); ipfw_bpf_uninit(last); return (0); } /* * Module event handler. * In general we have the choice of handling most of these events by the * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to * use the SYSINIT handlers as they are more capable of expressing the * flow of control during module and vnet operations, so this is just * a skeleton. Note there is no SYSINIT equivalent of the module * SHUTDOWN handler, but we don't have anything to do in that case anyhow. */ static int ipfw_modevent(module_t mod, int type, void *unused) { int err = 0; switch (type) { case MOD_LOAD: /* Called once at module load or * system boot if compiled in. */ break; case MOD_QUIESCE: /* Called before unload. May veto unloading. */ break; case MOD_UNLOAD: /* Called during unload. */ break; case MOD_SHUTDOWN: /* Called during system shutdown. */ break; default: err = EOPNOTSUPP; break; } return err; } static moduledata_t ipfwmod = { "ipfw", ipfw_modevent, 0 }; /* Define startup order. */ #define IPFW_SI_SUB_FIREWALL SI_SUB_PROTO_FIREWALL #define IPFW_MODEVENT_ORDER (SI_ORDER_ANY - 255) /* On boot slot in here. */ #define IPFW_MODULE_ORDER (IPFW_MODEVENT_ORDER + 1) /* A little later. */ #define IPFW_VNET_ORDER (IPFW_MODEVENT_ORDER + 2) /* Later still. */ DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER); FEATURE(ipfw_ctl3, "ipfw new sockopt calls"); MODULE_VERSION(ipfw, 3); /* should declare some dependencies here */ /* * Starting up. Done in order after ipfwmod() has been called. * VNET_SYSINIT is also called for each existing vnet and each new vnet. */ SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, ipfw_init, NULL); VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, vnet_ipfw_init, NULL); /* * Closing up shop. These are done in REVERSE ORDER, but still * after ipfwmod() has been called. Not called on reboot. * VNET_SYSUNINIT is also called for each exiting vnet as it exits. * or when the module is unloaded. */ SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER, ipfw_destroy, NULL); VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER, vnet_ipfw_uninit, NULL); /* end of file */