/* $OpenBSD: ipsec_input.c,v 1.156 2017/07/05 11:34:10 bluhm Exp $ */ /* * The authors of this code are John Ioannidis (ji@tla.org), * Angelos D. Keromytis (kermit@csd.uch.gr) and * Niels Provos (provos@physnet.uni-hamburg.de). * * This code was written by John Ioannidis for BSD/OS in Athens, Greece, * in November 1995. * * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996, * by Angelos D. Keromytis. * * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis * and Niels Provos. * * Additional features in 1999 by Angelos D. Keromytis. * * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis, * Angelos D. Keromytis and Niels Provos. * Copyright (c) 2001, Angelos D. Keromytis. * * Permission to use, copy, and modify this software with or without fee * is hereby granted, provided that this entire notice is included in * all copies of any software which is or includes a copy or * modification of this software. * You may use this code under the GNU public license if you so wish. Please * contribute changes back to the authors under this freer than GPL license * so that we may further the use of strong encryption without limitations to * all. * * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR * PURPOSE. */ #include "pf.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if NPF > 0 #include #endif #ifdef INET6 #include #include #include #include #endif /* INET6 */ #include #include #include #include #include #include "bpfilter.h" void ipsec_common_ctlinput(u_int, int, struct sockaddr *, void *, int); #ifdef ENCDEBUG #define DPRINTF(x) if (encdebug) printf x #else #define DPRINTF(x) #endif /* sysctl variables */ int esp_enable = 1; int ah_enable = 1; int ipcomp_enable = 0; int *espctl_vars[ESPCTL_MAXID] = ESPCTL_VARS; int *ahctl_vars[AHCTL_MAXID] = AHCTL_VARS; int *ipcompctl_vars[IPCOMPCTL_MAXID] = IPCOMPCTL_VARS; /* * ipsec_common_input() gets called when we receive an IPsec-protected packet * in IPv4 or IPv6. All it does is find the right TDB and call the appropriate * transform. The callback takes care of further processing (like ingress * filtering). */ int ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto, int udpencap) { #define IPSEC_ISTAT(x,y,z) (sproto == IPPROTO_ESP ? (x)++ : \ sproto == IPPROTO_AH ? (y)++ : (z)++) union sockaddr_union dst_address; struct tdb *tdbp; struct ifnet *encif; u_int32_t spi; u_int16_t cpi; int error; #ifdef ENCDEBUG char buf[INET6_ADDRSTRLEN]; #endif NET_ASSERT_LOCKED(); IPSEC_ISTAT(espstat.esps_input, ahstat.ahs_input, ipcompstat.ipcomps_input); if (m == NULL) { DPRINTF(("ipsec_common_input(): NULL packet received\n")); IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); return EINVAL; } if ((sproto == IPPROTO_ESP && !esp_enable) || (sproto == IPPROTO_AH && !ah_enable) || #if NPF > 0 (m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) || #endif (sproto == IPPROTO_IPCOMP && !ipcomp_enable)) { switch (af) { case AF_INET: rip_input(&m, &skip, sproto, af); break; #ifdef INET6 case AF_INET6: rip6_input(&m, &skip, sproto, af); break; #endif /* INET6 */ default: DPRINTF(("ipsec_common_input(): unsupported protocol " "family %d\n", af)); m_freem(m); IPSEC_ISTAT(espstat.esps_nopf, ahstat.ahs_nopf, ipcompstat.ipcomps_nopf); return EPFNOSUPPORT; } return 0; } if ((sproto == IPPROTO_IPCOMP) && (m->m_flags & M_COMP)) { m_freem(m); ipcompstat.ipcomps_pdrops++; DPRINTF(("ipsec_common_input(): repeated decompression\n")); return EINVAL; } if (m->m_pkthdr.len - skip < 2 * sizeof(u_int32_t)) { m_freem(m); IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); DPRINTF(("ipsec_common_input(): packet too small\n")); return EINVAL; } /* Retrieve the SPI from the relevant IPsec header */ switch (sproto) { case IPPROTO_ESP: m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi); break; case IPPROTO_AH: m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t), (caddr_t) &spi); break; case IPPROTO_IPCOMP: m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t), (caddr_t) &cpi); spi = ntohl(htons(cpi)); break; default: panic("%s: unknown/unsupported security protocol %d", __func__, sproto); } /* * Find tunnel control block and (indirectly) call the appropriate * kernel crypto routine. The resulting mbuf chain is a valid * IP packet ready to go through input processing. */ memset(&dst_address, 0, sizeof(dst_address)); dst_address.sa.sa_family = af; switch (af) { case AF_INET: dst_address.sin.sin_len = sizeof(struct sockaddr_in); m_copydata(m, offsetof(struct ip, ip_dst), sizeof(struct in_addr), (caddr_t) &(dst_address.sin.sin_addr)); break; #ifdef INET6 case AF_INET6: dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6); m_copydata(m, offsetof(struct ip6_hdr, ip6_dst), sizeof(struct in6_addr), (caddr_t) &(dst_address.sin6.sin6_addr)); in6_recoverscope(&dst_address.sin6, &dst_address.sin6.sin6_addr); break; #endif /* INET6 */ default: DPRINTF(("ipsec_common_input(): unsupported protocol " "family %d\n", af)); m_freem(m); IPSEC_ISTAT(espstat.esps_nopf, ahstat.ahs_nopf, ipcompstat.ipcomps_nopf); return EPFNOSUPPORT; } tdbp = gettdb(rtable_l2(m->m_pkthdr.ph_rtableid), spi, &dst_address, sproto); if (tdbp == NULL) { DPRINTF(("ipsec_common_input(): could not find SA for " "packet to %s, spi %08x\n", ipsp_address(&dst_address, buf, sizeof(buf)), ntohl(spi))); m_freem(m); IPSEC_ISTAT(espstat.esps_notdb, ahstat.ahs_notdb, ipcompstat.ipcomps_notdb); return ENOENT; } if (tdbp->tdb_flags & TDBF_INVALID) { DPRINTF(("ipsec_common_input(): attempted to use invalid " "SA %s/%08x/%u\n", ipsp_address(&dst_address, buf, sizeof(buf)), ntohl(spi), tdbp->tdb_sproto)); m_freem(m); IPSEC_ISTAT(espstat.esps_invalid, ahstat.ahs_invalid, ipcompstat.ipcomps_invalid); return EINVAL; } if (udpencap && !(tdbp->tdb_flags & TDBF_UDPENCAP)) { DPRINTF(("ipsec_common_input(): attempted to use non-udpencap " "SA %s/%08x/%u\n", ipsp_address(&dst_address, buf, sizeof(buf)), ntohl(spi), tdbp->tdb_sproto)); m_freem(m); espstat.esps_udpinval++; return EINVAL; } if (!udpencap && (tdbp->tdb_flags & TDBF_UDPENCAP)) { DPRINTF(("ipsec_common_input(): attempted to use udpencap " "SA %s/%08x/%u\n", ipsp_address(&dst_address, buf, sizeof(buf)), ntohl(spi), tdbp->tdb_sproto)); m_freem(m); espstat.esps_udpneeded++; return EINVAL; } if (tdbp->tdb_xform == NULL) { DPRINTF(("ipsec_common_input(): attempted to use uninitialized " "SA %s/%08x/%u\n", ipsp_address(&dst_address, buf, sizeof(buf)), ntohl(spi), tdbp->tdb_sproto)); m_freem(m); IPSEC_ISTAT(espstat.esps_noxform, ahstat.ahs_noxform, ipcompstat.ipcomps_noxform); return ENXIO; } if (sproto != IPPROTO_IPCOMP) { if ((encif = enc_getif(tdbp->tdb_rdomain, tdbp->tdb_tap)) == NULL) { DPRINTF(("ipsec_common_input(): " "no enc%u interface for SA %s/%08x/%u\n", tdbp->tdb_tap, ipsp_address(&dst_address, buf, sizeof(buf)), ntohl(spi), tdbp->tdb_sproto)); m_freem(m); IPSEC_ISTAT(espstat.esps_pdrops, ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops); return EACCES; } /* XXX This conflicts with the scoped nature of IPv6 */ m->m_pkthdr.ph_ifidx = encif->if_index; } /* Register first use, setup expiration timer. */ if (tdbp->tdb_first_use == 0) { tdbp->tdb_first_use = time_second; if (tdbp->tdb_flags & TDBF_FIRSTUSE) timeout_add_sec(&tdbp->tdb_first_tmo, tdbp->tdb_exp_first_use); if (tdbp->tdb_flags & TDBF_SOFT_FIRSTUSE) timeout_add_sec(&tdbp->tdb_sfirst_tmo, tdbp->tdb_soft_first_use); } /* * Call appropriate transform and return -- callback takes care of * everything else. */ error = (*(tdbp->tdb_xform->xf_input))(m, tdbp, skip, protoff); return error; } /* * IPsec input callback, called by the transform callback. Takes care of * filtering and other sanity checks on the processed packet. */ void ipsec_common_input_cb(struct mbuf *m, struct tdb *tdbp, int skip, int protoff) { int af, sproto; u_int8_t prot; #if NBPFILTER > 0 struct ifnet *encif; #endif struct ip *ip, ipn; #ifdef INET6 struct ip6_hdr *ip6, ip6n; #endif /* INET6 */ struct m_tag *mtag; struct tdb_ident *tdbi; #ifdef ENCDEBUG char buf[INET6_ADDRSTRLEN]; #endif af = tdbp->tdb_dst.sa.sa_family; sproto = tdbp->tdb_sproto; tdbp->tdb_last_used = time_second; /* Sanity check */ if (m == NULL) { /* The called routine will print a message if necessary */ IPSEC_ISTAT(espstat.esps_badkcr, ahstat.ahs_badkcr, ipcompstat.ipcomps_badkcr); return; } /* Fix IPv4 header */ if (af == AF_INET) { if ((m->m_len < skip) && ((m = m_pullup(m, skip)) == NULL)) { DPRINTF(("ipsec_common_input_cb(): processing failed " "for SA %s/%08x\n", ipsp_address(&tdbp->tdb_dst, buf, sizeof(buf)), ntohl(tdbp->tdb_spi))); IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); return; } ip = mtod(m, struct ip *); ip->ip_len = htons(m->m_pkthdr.len); ip->ip_sum = 0; ip->ip_sum = in_cksum(m, ip->ip_hl << 2); prot = ip->ip_p; /* IP-in-IP encapsulation */ if (prot == IPPROTO_IPIP) { if (m->m_pkthdr.len - skip < sizeof(struct ip)) { m_freem(m); IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); return; } /* ipn will now contain the inner IPv4 header */ m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn); } #ifdef INET6 /* IPv6-in-IP encapsulation. */ if (prot == IPPROTO_IPV6) { if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { m_freem(m); IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); return; } /* ip6n will now contain the inner IPv6 header. */ m_copydata(m, skip, sizeof(struct ip6_hdr), (caddr_t) &ip6n); } #endif /* INET6 */ } #ifdef INET6 /* Fix IPv6 header */ if (af == AF_INET6) { if (m->m_len < sizeof(struct ip6_hdr) && (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { DPRINTF(("ipsec_common_input_cb(): processing failed " "for SA %s/%08x\n", ipsp_address(&tdbp->tdb_dst, buf, sizeof(buf)), ntohl(tdbp->tdb_spi))); IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); return; } ip6 = mtod(m, struct ip6_hdr *); ip6->ip6_plen = htons(m->m_pkthdr.len - skip); /* Save protocol */ m_copydata(m, protoff, 1, (caddr_t) &prot); /* IP-in-IP encapsulation */ if (prot == IPPROTO_IPIP) { if (m->m_pkthdr.len - skip < sizeof(struct ip)) { m_freem(m); IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); return; } /* ipn will now contain the inner IPv4 header */ m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn); } /* IPv6-in-IP encapsulation */ if (prot == IPPROTO_IPV6) { if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) { m_freem(m); IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); return; } /* ip6n will now contain the inner IPv6 header. */ m_copydata(m, skip, sizeof(struct ip6_hdr), (caddr_t) &ip6n); } } #endif /* INET6 */ /* * Fix TCP/UDP checksum of UDP encapsulated transport mode ESP packet. * (RFC3948 3.1.2) */ if ((af == AF_INET || af == AF_INET6) && (tdbp->tdb_flags & TDBF_UDPENCAP) && (tdbp->tdb_flags & TDBF_TUNNELING) == 0) { u_int16_t cksum; switch (prot) { case IPPROTO_UDP: if (m->m_pkthdr.len < skip + sizeof(struct udphdr)) { m_freem(m); IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); return; } cksum = 0; m_copyback(m, skip + offsetof(struct udphdr, uh_sum), sizeof(cksum), &cksum, M_NOWAIT); #ifdef INET6 if (af == AF_INET6) { cksum = in6_cksum(m, IPPROTO_UDP, skip, m->m_pkthdr.len - skip); m_copyback(m, skip + offsetof(struct udphdr, uh_sum), sizeof(cksum), &cksum, M_NOWAIT); } #endif break; case IPPROTO_TCP: if (m->m_pkthdr.len < skip + sizeof(struct tcphdr)) { m_freem(m); IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); return; } cksum = 0; m_copyback(m, skip + offsetof(struct tcphdr, th_sum), sizeof(cksum), &cksum, M_NOWAIT); if (af == AF_INET) cksum = in4_cksum(m, IPPROTO_TCP, skip, m->m_pkthdr.len - skip); #ifdef INET6 else if (af == AF_INET6) cksum = in6_cksum(m, IPPROTO_TCP, skip, m->m_pkthdr.len - skip); #endif m_copyback(m, skip + offsetof(struct tcphdr, th_sum), sizeof(cksum), &cksum, M_NOWAIT); break; } } /* * Record what we've done to the packet (under what SA it was * processed). */ if (tdbp->tdb_sproto != IPPROTO_IPCOMP) { mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE, sizeof(struct tdb_ident), M_NOWAIT); if (mtag == NULL) { m_freem(m); DPRINTF(("ipsec_common_input_cb(): failed to " "get tag\n")); IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); return; } tdbi = (struct tdb_ident *)(mtag + 1); tdbi->dst = tdbp->tdb_dst; tdbi->proto = tdbp->tdb_sproto; tdbi->spi = tdbp->tdb_spi; tdbi->rdomain = tdbp->tdb_rdomain; m_tag_prepend(m, mtag); } switch (sproto) { case IPPROTO_ESP: /* Packet is confidential ? */ if (tdbp->tdb_encalgxform) m->m_flags |= M_CONF; /* Check if we had authenticated ESP. */ if (tdbp->tdb_authalgxform) m->m_flags |= M_AUTH; break; case IPPROTO_AH: m->m_flags |= M_AUTH; break; case IPPROTO_IPCOMP: m->m_flags |= M_COMP; break; default: panic("%s: unknown/unsupported security protocol %d", __func__, sproto); } #if NPF > 0 /* Add pf tag if requested. */ pf_tag_packet(m, tdbp->tdb_tag, -1); pf_pkt_addr_changed(m); #endif if (tdbp->tdb_flags & TDBF_TUNNELING) m->m_flags |= M_TUNNEL; #if NBPFILTER > 0 if ((encif = enc_getif(tdbp->tdb_rdomain, tdbp->tdb_tap)) != NULL) { encif->if_ipackets++; encif->if_ibytes += m->m_pkthdr.len; if (encif->if_bpf) { struct enchdr hdr; hdr.af = af; hdr.spi = tdbp->tdb_spi; hdr.flags = m->m_flags & (M_AUTH|M_CONF); bpf_mtap_hdr(encif->if_bpf, (char *)&hdr, ENC_HDRLEN, m, BPF_DIRECTION_IN, NULL); } } #endif #if NPF > 0 /* * The ip_deliver() shortcut avoids running through ip_input() with the * same IP header twice. Packets in transport mode have to be be * passed to pf explicitly. In tunnel mode the inner IP header will * run through ip_input() and pf anyway. */ if ((tdbp->tdb_flags & TDBF_TUNNELING) == 0) { struct ifnet *ifp; /* This is the enc0 interface unless for ipcomp. */ if ((ifp = if_get(m->m_pkthdr.ph_ifidx)) == NULL) { m_freem(m); return; } if (pf_test(af, PF_IN, ifp, &m) != PF_PASS) { if_put(ifp); m_freem(m); return; } if_put(ifp); if (m == NULL) return; } #endif /* Call the appropriate IPsec transform callback. */ ip_deliver(&m, &skip, prot, af); #undef IPSEC_ISTAT } int esp_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, size_t newlen) { /* All sysctl names at this level are terminal. */ if (namelen != 1) return (ENOTDIR); switch (name[0]) { case ESPCTL_STATS: if (newp != NULL) return (EPERM); return (sysctl_struct(oldp, oldlenp, newp, newlen, &espstat, sizeof(espstat))); default: if (name[0] < ESPCTL_MAXID) return (sysctl_int_arr(espctl_vars, name, namelen, oldp, oldlenp, newp, newlen)); return (ENOPROTOOPT); } } int ah_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, size_t newlen) { /* All sysctl names at this level are terminal. */ if (namelen != 1) return (ENOTDIR); switch (name[0]) { case AHCTL_STATS: if (newp != NULL) return (EPERM); return (sysctl_struct(oldp, oldlenp, newp, newlen, &ahstat, sizeof(ahstat))); default: if (name[0] < AHCTL_MAXID) return (sysctl_int_arr(ahctl_vars, name, namelen, oldp, oldlenp, newp, newlen)); return (ENOPROTOOPT); } } int ipcomp_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, size_t newlen) { /* All sysctl names at this level are terminal. */ if (namelen != 1) return (ENOTDIR); switch (name[0]) { case IPCOMPCTL_STATS: if (newp != NULL) return (EPERM); return (sysctl_struct(oldp, oldlenp, newp, newlen, &ipcompstat, sizeof(ipcompstat))); default: if (name[0] < IPCOMPCTL_MAXID) return (sysctl_int_arr(ipcompctl_vars, name, namelen, oldp, oldlenp, newp, newlen)); return (ENOPROTOOPT); } } /* IPv4 AH wrapper. */ int ah4_input(struct mbuf **mp, int *offp, int proto, int af) { ipsec_common_input(*mp, *offp, offsetof(struct ip, ip_p), AF_INET, proto, 0); return IPPROTO_DONE; } /* XXX rdomain */ void ah4_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *v) { if (sa->sa_family != AF_INET || sa->sa_len != sizeof(struct sockaddr_in)) return; ipsec_common_ctlinput(rdomain, cmd, sa, v, IPPROTO_AH); } /* IPv4 ESP wrapper. */ int esp4_input(struct mbuf **mp, int *offp, int proto, int af) { ipsec_common_input(*mp, *offp, offsetof(struct ip, ip_p), AF_INET, proto, 0); return IPPROTO_DONE; } /* IPv4 IPCOMP wrapper */ int ipcomp4_input(struct mbuf **mp, int *offp, int proto, int af) { ipsec_common_input(*mp, *offp, offsetof(struct ip, ip_p), AF_INET, proto, 0); return IPPROTO_DONE; } void ipsec_common_ctlinput(u_int rdomain, int cmd, struct sockaddr *sa, void *v, int proto) { struct ip *ip = v; if (cmd == PRC_MSGSIZE && ip && ip_mtudisc && ip->ip_v == 4) { struct tdb *tdbp; struct sockaddr_in dst; struct icmp *icp; int hlen = ip->ip_hl << 2; u_int32_t spi, mtu; ssize_t adjust; /* Find the right MTU. */ icp = (struct icmp *)((caddr_t) ip - offsetof(struct icmp, icmp_ip)); mtu = ntohs(icp->icmp_nextmtu); /* * Ignore the packet, if we do not receive a MTU * or the MTU is too small to be acceptable. */ if (mtu < 296) return; memset(&dst, 0, sizeof(struct sockaddr_in)); dst.sin_family = AF_INET; dst.sin_len = sizeof(struct sockaddr_in); dst.sin_addr.s_addr = ip->ip_dst.s_addr; memcpy(&spi, (caddr_t)ip + hlen, sizeof(u_int32_t)); tdbp = gettdb(rdomain, spi, (union sockaddr_union *)&dst, proto); if (tdbp == NULL || tdbp->tdb_flags & TDBF_INVALID) return; /* Walk the chain backwards to the first tdb */ for (; tdbp; tdbp = tdbp->tdb_inext) { if (tdbp->tdb_flags & TDBF_INVALID || (adjust = ipsec_hdrsz(tdbp)) == -1) return; mtu -= adjust; /* Store adjusted MTU in tdb */ tdbp->tdb_mtu = mtu; tdbp->tdb_mtutimeout = time_second + ip_mtudisc_timeout; DPRINTF(("ipsec_common_ctlinput: " "spi %08x mtu %d adjust %ld\n", ntohl(tdbp->tdb_spi), tdbp->tdb_mtu, adjust)); } } } /* XXX rdomain */ void udpencap_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *v) { struct ip *ip = v; struct tdb *tdbp; struct icmp *icp; u_int32_t mtu; ssize_t adjust; struct sockaddr_in dst, src; union sockaddr_union *su_dst, *su_src; NET_ASSERT_LOCKED(); icp = (struct icmp *)((caddr_t) ip - offsetof(struct icmp, icmp_ip)); mtu = ntohs(icp->icmp_nextmtu); /* * Ignore the packet, if we do not receive a MTU * or the MTU is too small to be acceptable. */ if (mtu < 296) return; memset(&dst, 0, sizeof(dst)); dst.sin_family = AF_INET; dst.sin_len = sizeof(struct sockaddr_in); dst.sin_addr.s_addr = ip->ip_dst.s_addr; su_dst = (union sockaddr_union *)&dst; memset(&src, 0, sizeof(src)); src.sin_family = AF_INET; src.sin_len = sizeof(struct sockaddr_in); src.sin_addr.s_addr = ip->ip_src.s_addr; su_src = (union sockaddr_union *)&src; tdbp = gettdbbysrcdst(rdomain, 0, su_src, su_dst, IPPROTO_ESP); for (; tdbp != NULL; tdbp = tdbp->tdb_snext) { if (tdbp->tdb_sproto == IPPROTO_ESP && ((tdbp->tdb_flags & (TDBF_INVALID|TDBF_UDPENCAP)) == TDBF_UDPENCAP) && !memcmp(&tdbp->tdb_dst, &dst, su_dst->sa.sa_len) && !memcmp(&tdbp->tdb_src, &src, su_src->sa.sa_len)) { if ((adjust = ipsec_hdrsz(tdbp)) != -1) { /* Store adjusted MTU in tdb */ tdbp->tdb_mtu = mtu - adjust; tdbp->tdb_mtutimeout = time_second + ip_mtudisc_timeout; DPRINTF(("udpencap_ctlinput: " "spi %08x mtu %d adjust %ld\n", ntohl(tdbp->tdb_spi), tdbp->tdb_mtu, adjust)); } } } } /* XXX rdomain */ void esp4_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *v) { if (sa->sa_family != AF_INET || sa->sa_len != sizeof(struct sockaddr_in)) return; ipsec_common_ctlinput(rdomain, cmd, sa, v, IPPROTO_ESP); } #ifdef INET6 /* IPv6 AH wrapper. */ int ah6_input(struct mbuf **mp, int *offp, int proto, int af) { int l = 0; int protoff, nxt; struct ip6_ext ip6e; if (*offp < sizeof(struct ip6_hdr)) { DPRINTF(("ah6_input(): bad offset\n")); ahstat.ahs_hdrops++; m_freemp(mp); return IPPROTO_DONE; } else if (*offp == sizeof(struct ip6_hdr)) { protoff = offsetof(struct ip6_hdr, ip6_nxt); } else { /* Chase down the header chain... */ protoff = sizeof(struct ip6_hdr); nxt = (mtod(*mp, struct ip6_hdr *))->ip6_nxt; do { protoff += l; m_copydata(*mp, protoff, sizeof(ip6e), (caddr_t) &ip6e); if (nxt == IPPROTO_AH) l = (ip6e.ip6e_len + 2) << 2; else l = (ip6e.ip6e_len + 1) << 3; #ifdef DIAGNOSTIC if (l <= 0) panic("ah6_input: l went zero or negative"); #endif nxt = ip6e.ip6e_nxt; } while (protoff + l < *offp); /* Malformed packet check */ if (protoff + l != *offp) { DPRINTF(("ah6_input(): bad packet header chain\n")); ahstat.ahs_hdrops++; m_freemp(mp); return IPPROTO_DONE; } protoff += offsetof(struct ip6_ext, ip6e_nxt); } ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto, 0); return IPPROTO_DONE; } /* IPv6 ESP wrapper. */ int esp6_input(struct mbuf **mp, int *offp, int proto, int af) { int l = 0; int protoff, nxt; struct ip6_ext ip6e; if (*offp < sizeof(struct ip6_hdr)) { DPRINTF(("esp6_input(): bad offset\n")); espstat.esps_hdrops++; m_freemp(mp); return IPPROTO_DONE; } else if (*offp == sizeof(struct ip6_hdr)) { protoff = offsetof(struct ip6_hdr, ip6_nxt); } else { /* Chase down the header chain... */ protoff = sizeof(struct ip6_hdr); nxt = (mtod(*mp, struct ip6_hdr *))->ip6_nxt; do { protoff += l; m_copydata(*mp, protoff, sizeof(ip6e), (caddr_t) &ip6e); if (nxt == IPPROTO_AH) l = (ip6e.ip6e_len + 2) << 2; else l = (ip6e.ip6e_len + 1) << 3; #ifdef DIAGNOSTIC if (l <= 0) panic("esp6_input: l went zero or negative"); #endif nxt = ip6e.ip6e_nxt; } while (protoff + l < *offp); /* Malformed packet check */ if (protoff + l != *offp) { DPRINTF(("esp6_input(): bad packet header chain\n")); espstat.esps_hdrops++; m_freemp(mp); return IPPROTO_DONE; } protoff += offsetof(struct ip6_ext, ip6e_nxt); } ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto, 0); return IPPROTO_DONE; } /* IPv6 IPcomp wrapper */ int ipcomp6_input(struct mbuf **mp, int *offp, int proto, int af) { int l = 0; int protoff, nxt; struct ip6_ext ip6e; if (*offp < sizeof(struct ip6_hdr)) { DPRINTF(("ipcomp6_input(): bad offset\n")); ipcompstat.ipcomps_hdrops++; m_freemp(mp); return IPPROTO_DONE; } else if (*offp == sizeof(struct ip6_hdr)) { protoff = offsetof(struct ip6_hdr, ip6_nxt); } else { /* Chase down the header chain... */ protoff = sizeof(struct ip6_hdr); nxt = (mtod(*mp, struct ip6_hdr *))->ip6_nxt; do { protoff += l; m_copydata(*mp, protoff, sizeof(ip6e), (caddr_t) &ip6e); if (nxt == IPPROTO_AH) l = (ip6e.ip6e_len + 2) << 2; else l = (ip6e.ip6e_len + 1) << 3; #ifdef DIAGNOSTIC if (l <= 0) panic("ipcomp6_input: l went zero or negative"); #endif nxt = ip6e.ip6e_nxt; } while (protoff + l < *offp); /* Malformed packet check */ if (protoff + l != *offp) { DPRINTF(("ipcomp6_input(): bad packet header chain\n")); ipcompstat.ipcomps_hdrops++; m_freemp(mp); return IPPROTO_DONE; } protoff += offsetof(struct ip6_ext, ip6e_nxt); } ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto, 0); return IPPROTO_DONE; } #endif /* INET6 */ int ipsec_forward_check(struct mbuf *m, int hlen, int af) { struct tdb *tdb; struct tdb_ident *tdbi; struct m_tag *mtag; int error = 0; /* * IPsec policy check for forwarded packets. Look at * inner-most IPsec SA used. */ mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); if (mtag != NULL) { tdbi = (struct tdb_ident *)(mtag + 1); tdb = gettdb(tdbi->rdomain, tdbi->spi, &tdbi->dst, tdbi->proto); } else tdb = NULL; ipsp_spd_lookup(m, af, hlen, &error, IPSP_DIRECTION_IN, tdb, NULL, 0); return error; } int ipsec_local_check(struct mbuf *m, int hlen, int proto, int af) { struct tdb *tdb; struct tdb_ident *tdbi; struct m_tag *mtag; int error = 0; /* * If it's a protected packet for us, skip the policy check. * That's because we really only care about the properties of * the protected packet, and not the intermediate versions. * While this is not the most paranoid setting, it allows * some flexibility in handling nested tunnels (in setting up * the policies). */ if ((proto == IPPROTO_ESP) || (proto == IPPROTO_AH) || (proto == IPPROTO_IPCOMP)) return 0; /* * If the protected packet was tunneled, then we need to * verify the protected packet's information, not the * external headers. Thus, skip the policy lookup for the * external packet, and keep the IPsec information linked on * the packet header (the encapsulation routines know how * to deal with that). */ if ((proto == IPPROTO_IPV4) || (proto == IPPROTO_IPV6)) return 0; /* * When processing IPv6 header chains, do not look at the * outer header. The inner protocol is relevant and will * be checked by the local delivery loop later. */ if ((af == AF_INET6) && ((proto == IPPROTO_DSTOPTS) || (proto == IPPROTO_ROUTING) || (proto == IPPROTO_FRAGMENT))) return 0; /* * If the protected packet is TCP or UDP, we'll do the * policy check in the respective input routine, so we can * check for bypass sockets. */ if ((proto == IPPROTO_TCP) || (proto == IPPROTO_UDP)) return 0; /* * IPsec policy check for local-delivery packets. Look at the * inner-most SA that protected the packet. This is in fact * a bit too restrictive (it could end up causing packets to * be dropped that semantically follow the policy, e.g., in * certain SA-bundle configurations); but the alternative is * very complicated (and requires keeping track of what * kinds of tunneling headers have been seen in-between the * IPsec headers), and I don't think we lose much functionality * that's needed in the real world (who uses bundles anyway ?). */ mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL); if (mtag) { tdbi = (struct tdb_ident *)(mtag + 1); tdb = gettdb(tdbi->rdomain, tdbi->spi, &tdbi->dst, tdbi->proto); } else tdb = NULL; ipsp_spd_lookup(m, af, hlen, &error, IPSP_DIRECTION_IN, tdb, NULL, 0); return error; }