/* $OpenBSD: ipsec_input.c,v 1.83 2007/02/08 15:25:30 itojun 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 #if NPF > 0 #include #endif #include #include #include #include #include #include #include #include #ifdef INET6 #ifndef INET #include #endif #include #include #include #endif /* INET6 */ #include #include #include #include #include #include "bpfilter.h" void *ipsec_common_ctlinput(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; #ifdef INET6 extern struct ip6protosw inet6sw[]; extern u_char ip6_protox[]; #endif /* * 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 timeval tv; struct tdb *tdbp; u_int32_t spi; u_int16_t cpi; int s, error; IPSEC_ISTAT(espstat.esps_input, ahstat.ahs_input, ipcompstat.ipcomps_input); if (m == 0) { 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) || (sproto == IPPROTO_IPCOMP && !ipcomp_enable)) { rip_input(m, skip, sproto); return 0; } 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 */ if (sproto == IPPROTO_ESP) m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi); else if (sproto == IPPROTO_AH) m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t), (caddr_t) &spi); else if (sproto == IPPROTO_IPCOMP) { m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t), (caddr_t) &cpi); spi = ntohl(htons(cpi)); } /* * 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. */ bzero(&dst_address, sizeof(dst_address)); dst_address.sa.sa_family = af; switch (af) { #ifdef INET 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; #endif /* INET */ #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, NULL); 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; } s = spltdb(); tdbp = gettdb(spi, &dst_address, sproto); if (tdbp == NULL) { splx(s); DPRINTF(("ipsec_common_input(): could not find SA for " "packet to %s, spi %08x\n", ipsp_address(dst_address), ntohl(spi))); m_freem(m); IPSEC_ISTAT(espstat.esps_notdb, ahstat.ahs_notdb, ipcompstat.ipcomps_notdb); return ENOENT; } if (tdbp->tdb_flags & TDBF_INVALID) { splx(s); DPRINTF(("ipsec_common_input(): attempted to use invalid SA %s/%08x/%u\n", ipsp_address(dst_address), 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)) { splx(s); DPRINTF(("ipsec_common_input(): attempted to use non-udpencap SA %s/%08x/%u\n", ipsp_address(dst_address), ntohl(spi), tdbp->tdb_sproto)); m_freem(m); espstat.esps_udpinval++; return EINVAL; } if (tdbp->tdb_xform == NULL) { splx(s); DPRINTF(("ipsec_common_input(): attempted to use uninitialized SA %s/%08x/%u\n", ipsp_address(dst_address), ntohl(spi), tdbp->tdb_sproto)); m_freem(m); IPSEC_ISTAT(espstat.esps_noxform, ahstat.ahs_noxform, ipcompstat.ipcomps_noxform); return ENXIO; } if (tdbp->tdb_dst.sa.sa_family == AF_INET && sproto != IPPROTO_IPCOMP) { /* * XXX The fragment conflicts with scoped nature of * IPv6, so do it for only for IPv4 for now. */ m->m_pkthdr.rcvif = &encif[0].sc_if; } /* Register first use, setup expiration timer. */ if (tdbp->tdb_first_use == 0) { tdbp->tdb_first_use = time_second; tv.tv_usec = 0; tv.tv_sec = tdbp->tdb_exp_first_use + tdbp->tdb_first_use; if (tdbp->tdb_flags & TDBF_FIRSTUSE) timeout_add(&tdbp->tdb_first_tmo, hzto(&tv)); tv.tv_sec = tdbp->tdb_first_use + tdbp->tdb_soft_first_use; if (tdbp->tdb_flags & TDBF_SOFT_FIRSTUSE) timeout_add(&tdbp->tdb_sfirst_tmo, hzto(&tv)); } /* * Call appropriate transform and return -- callback takes care of * everything else. */ error = (*(tdbp->tdb_xform->xf_input))(m, tdbp, skip, protoff); splx(s); return error; } /* * IPsec input callback, called by the transform callback. Takes care of * filtering and other sanity checks on the processed packet. */ int ipsec_common_input_cb(struct mbuf *m, struct tdb *tdbp, int skip, int protoff, struct m_tag *mt) { int prot, af, sproto; #if NBPFILTER > 0 struct ifnet *bpfif; #endif #ifdef INET struct ip *ip, ipn; #endif /* INET */ #ifdef INET6 struct ip6_hdr *ip6, ip6n; #endif /* INET6 */ struct m_tag *mtag; struct tdb_ident *tdbi; 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 EINVAL; } #ifdef INET /* Fix IPv4 header */ if (tdbp->tdb_dst.sa.sa_family == 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), ntohl(tdbp->tdb_spi))); IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); return ENOBUFS; } 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 EINVAL; } /* ipn will now contain the inner IPv4 header */ m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn); /* * Check that the inner source address is the same as * the proxy address, if available. */ if ((tdbp->tdb_proxy.sa.sa_family == AF_INET && tdbp->tdb_proxy.sin.sin_addr.s_addr != INADDR_ANY && ipn.ip_src.s_addr != tdbp->tdb_proxy.sin.sin_addr.s_addr) || (tdbp->tdb_proxy.sa.sa_family != AF_INET && tdbp->tdb_proxy.sa.sa_family != 0)) { DPRINTF(("ipsec_common_input_cb(): inner " "source address %s doesn't correspond to " "expected proxy source %s, SA %s/%08x\n", inet_ntoa4(ipn.ip_src), ipsp_address(tdbp->tdb_proxy), ipsp_address(tdbp->tdb_dst), ntohl(tdbp->tdb_spi))); m_freem(m); IPSEC_ISTAT(espstat.esps_pdrops, ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops); return EACCES; } } #if 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 EINVAL; } /* ip6n will now contain the inner IPv6 header. */ m_copydata(m, skip, sizeof(struct ip6_hdr), (caddr_t) &ip6n); /* * Check that the inner source address is the same as * the proxy address, if available. */ if ((tdbp->tdb_proxy.sa.sa_family == AF_INET6 && !IN6_IS_ADDR_UNSPECIFIED(&tdbp->tdb_proxy.sin6.sin6_addr) && !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, &tdbp->tdb_proxy.sin6.sin6_addr)) || (tdbp->tdb_proxy.sa.sa_family != AF_INET6 && tdbp->tdb_proxy.sa.sa_family != 0)) { DPRINTF(("ipsec_common_input_cb(): inner " "source address %s doesn't correspond to " "expected proxy source %s, SA %s/%08x\n", ip6_sprintf(&ip6n.ip6_src), ipsp_address(tdbp->tdb_proxy), ipsp_address(tdbp->tdb_dst), ntohl(tdbp->tdb_spi))); m_freem(m); IPSEC_ISTAT(espstat.esps_pdrops, ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops); return EACCES; } } #endif /* INET6 */ } #endif /* INET */ #ifdef INET6 /* Fix IPv6 header */ if (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), ntohl(tdbp->tdb_spi))); IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops); return EACCES; } ip6 = mtod(m, struct ip6_hdr *); ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); /* Save protocol */ m_copydata(m, protoff, 1, (unsigned char *) &prot); #ifdef INET /* 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 EINVAL; } /* ipn will now contain the inner IPv4 header */ m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn); /* * Check that the inner source address is the same as * the proxy address, if available. */ if ((tdbp->tdb_proxy.sa.sa_family == AF_INET && tdbp->tdb_proxy.sin.sin_addr.s_addr != INADDR_ANY && ipn.ip_src.s_addr != tdbp->tdb_proxy.sin.sin_addr.s_addr) || (tdbp->tdb_proxy.sa.sa_family != AF_INET && tdbp->tdb_proxy.sa.sa_family != 0)) { DPRINTF(("ipsec_common_input_cb(): inner " "source address %s doesn't correspond to " "expected proxy source %s, SA %s/%08x\n", inet_ntoa4(ipn.ip_src), ipsp_address(tdbp->tdb_proxy), ipsp_address(tdbp->tdb_dst), ntohl(tdbp->tdb_spi))); m_freem(m); IPSEC_ISTAT(espstat.esps_pdrops, ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops); return EACCES; } } #endif /* INET */ /* 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 EINVAL; } /* ip6n will now contain the inner IPv6 header. */ m_copydata(m, skip, sizeof(struct ip6_hdr), (caddr_t) &ip6n); /* * Check that the inner source address is the same as * the proxy address, if available. */ if ((tdbp->tdb_proxy.sa.sa_family == AF_INET6 && !IN6_IS_ADDR_UNSPECIFIED(&tdbp->tdb_proxy.sin6.sin6_addr) && !IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src, &tdbp->tdb_proxy.sin6.sin6_addr)) || (tdbp->tdb_proxy.sa.sa_family != AF_INET6 && tdbp->tdb_proxy.sa.sa_family != 0)) { DPRINTF(("ipsec_common_input_cb(): inner " "source address %s doesn't correspond to " "expected proxy source %s, SA %s/%08x\n", ip6_sprintf(&ip6n.ip6_src), ipsp_address(tdbp->tdb_proxy), ipsp_address(tdbp->tdb_dst), ntohl(tdbp->tdb_spi))); m_freem(m); IPSEC_ISTAT(espstat.esps_pdrops, ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops); return EACCES; } } } #endif /* INET6 */ /* * Record what we've done to the packet (under what SA it was * processed). If we've been passed an mtag, it means the packet * was already processed by an ethernet/crypto combo card and * thus has a tag attached with all the right information, but * with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to * PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type. */ if (mt == NULL && 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 ENOMEM; } tdbi = (struct tdb_ident *)(mtag + 1); bcopy(&tdbp->tdb_dst, &tdbi->dst, sizeof(union sockaddr_union)); tdbi->proto = tdbp->tdb_sproto; tdbi->spi = tdbp->tdb_spi; m_tag_prepend(m, mtag); } else { if (mt != NULL) mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE; } if (sproto == 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; } else if (sproto == IPPROTO_AH) m->m_flags |= M_AUTH | M_AUTH_AH; #if NPF > 0 /* Add pf tag if requested. */ if (pf_tag_packet(m, NULL, tdbp->tdb_tag, -1)) DPRINTF(("failed to tag ipsec packet\n")); #endif if (tdbp->tdb_flags & TDBF_TUNNELING) m->m_flags |= M_TUNNEL; #if NBPFILTER > 0 bpfif = &encif[0].sc_if; bpfif->if_ipackets++; bpfif->if_ibytes += m->m_pkthdr.len; if (bpfif->if_bpf) { struct enchdr hdr; hdr.af = af; hdr.spi = tdbp->tdb_spi; hdr.flags = m->m_flags & (M_AUTH|M_CONF|M_AUTH_AH); bpf_mtap_hdr(bpfif->if_bpf, (char *)&hdr, ENC_HDRLEN, m, BPF_DIRECTION_IN); } #endif /* Call the appropriate IPsec transform callback. */ switch (af) { #ifdef INET case AF_INET: switch (sproto) { case IPPROTO_ESP: return esp4_input_cb(m); case IPPROTO_AH: return ah4_input_cb(m); case IPPROTO_IPCOMP: return ipcomp4_input_cb(m); default: DPRINTF(("ipsec_common_input_cb(): unknown/unsupported" " security protocol %d\n", sproto)); m_freem(m); return EPFNOSUPPORT; } break; #endif /* INET */ #ifdef INET6 case AF_INET6: switch (sproto) { case IPPROTO_ESP: return esp6_input_cb(m, skip, protoff); case IPPROTO_AH: return ah6_input_cb(m, skip, protoff); case IPPROTO_IPCOMP: return ipcomp6_input_cb(m, skip, protoff); default: DPRINTF(("ipsec_common_input_cb(): unknown/unsupported" " security protocol %d\n", sproto)); m_freem(m); return EPFNOSUPPORT; } break; #endif /* INET6 */ default: DPRINTF(("ipsec_common_input_cb(): unknown/unsupported " "protocol family %d\n", af)); m_freem(m); return EPFNOSUPPORT; } #undef IPSEC_ISTAT } int esp_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, size_t newlen) { 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) { 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) { if (name[0] < IPCOMPCTL_MAXID) return (sysctl_int_arr(ipcompctl_vars, name, namelen, oldp, oldlenp, newp, newlen)); return (ENOPROTOOPT); } #ifdef INET /* IPv4 AH wrapper. */ void ah4_input(struct mbuf *m, ...) { int skip; va_list ap; va_start(ap, m); skip = va_arg(ap, int); va_end(ap); ipsec_common_input(m, skip, offsetof(struct ip, ip_p), AF_INET, IPPROTO_AH, 0); return; } /* IPv4 AH callback. */ int ah4_input_cb(struct mbuf *m, ...) { struct ifqueue *ifq = &ipintrq; int s = splnet(); /* * Interface pointer is already in first mbuf; chop off the * `outer' header and reschedule. */ if (IF_QFULL(ifq)) { IF_DROP(ifq); ahstat.ahs_qfull++; splx(s); m_freem(m); DPRINTF(("ah4_input_cb(): dropped packet because of full " "IP queue\n")); return ENOBUFS; } IF_ENQUEUE(ifq, m); schednetisr(NETISR_IP); splx(s); return 0; } void * ah4_ctlinput(int cmd, struct sockaddr *sa, void *v) { if (sa->sa_family != AF_INET || sa->sa_len != sizeof(struct sockaddr_in)) return (NULL); return (ipsec_common_ctlinput(cmd, sa, v, IPPROTO_AH)); } /* IPv4 ESP wrapper. */ void esp4_input(struct mbuf *m, ...) { int skip; va_list ap; va_start(ap, m); skip = va_arg(ap, int); va_end(ap); ipsec_common_input(m, skip, offsetof(struct ip, ip_p), AF_INET, IPPROTO_ESP, 0); } /* IPv4 ESP callback. */ int esp4_input_cb(struct mbuf *m, ...) { struct ifqueue *ifq = &ipintrq; int s = splnet(); /* * Interface pointer is already in first mbuf; chop off the * `outer' header and reschedule. */ if (IF_QFULL(ifq)) { IF_DROP(ifq); espstat.esps_qfull++; splx(s); m_freem(m); DPRINTF(("esp4_input_cb(): dropped packet because of full " "IP queue\n")); return ENOBUFS; } IF_ENQUEUE(ifq, m); schednetisr(NETISR_IP); splx(s); return 0; } /* IPv4 IPCOMP wrapper */ void ipcomp4_input(struct mbuf *m, ...) { int skip; va_list ap; va_start(ap, m); skip = va_arg(ap, int); va_end(ap); ipsec_common_input(m, skip, offsetof(struct ip, ip_p), AF_INET, IPPROTO_IPCOMP, 0); } /* IPv4 IPCOMP callback */ int ipcomp4_input_cb(struct mbuf *m, ...) { struct ifqueue *ifq = &ipintrq; int s = splnet(); /* * Interface pointer is already in first mbuf; chop off the * `outer' header and reschedule. */ if (IF_QFULL(ifq)) { IF_DROP(ifq); ipcompstat.ipcomps_qfull++; splx(s); m_freem(m); DPRINTF(("ipcomp4_input_cb(): dropped packet because of full IP queue\n")); return ENOBUFS; } IF_ENQUEUE(ifq, m); schednetisr(NETISR_IP); splx(s); return 0; } void * ipsec_common_ctlinput(int cmd, struct sockaddr *sa, void *v, int proto) { extern u_int ip_mtudisc_timeout; struct ip *ip = v; int s; 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 (NULL); bzero(&dst, 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; bcopy((caddr_t)ip + hlen, &spi, sizeof(u_int32_t)); s = spltdb(); tdbp = gettdb(spi, (union sockaddr_union *)&dst, proto); if (tdbp == NULL || tdbp->tdb_flags & TDBF_INVALID) { splx(s); return (NULL); } /* Walk the chain backswards to the first tdb */ for (; tdbp; tdbp = tdbp->tdb_inext) { if (tdbp->tdb_flags & TDBF_INVALID || (adjust = ipsec_hdrsz(tdbp)) == -1) { splx(s); return (NULL); } 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 %d\n", ntohl(tdbp->tdb_spi), tdbp->tdb_mtu, adjust)); } splx(s); return (NULL); } return (NULL); } void * udpencap_ctlinput(int cmd, struct sockaddr *sa, 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; int s; 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 (NULL); bzero(&dst, 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; bzero(&src, 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; s = spltdb(); tdbp = gettdbbysrcdst(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) && !bcmp(&tdbp->tdb_dst, &dst, SA_LEN(&su_dst->sa)) && !bcmp(&tdbp->tdb_src, &src, SA_LEN(&su_src->sa))) { 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 %d\n", ntohl(tdbp->tdb_spi), tdbp->tdb_mtu, adjust)); } } } splx(s); return (NULL); } void * esp4_ctlinput(int cmd, struct sockaddr *sa, void *v) { if (sa->sa_family != AF_INET || sa->sa_len != sizeof(struct sockaddr_in)) return (NULL); return (ipsec_common_ctlinput(cmd, sa, v, IPPROTO_ESP)); } #endif /* INET */ #ifdef INET6 /* IPv6 AH wrapper. */ int ah6_input(struct mbuf **mp, int *offp, int proto) { int l = 0; int protoff, nxt; struct ip6_ext ip6e; if (*offp < sizeof(struct ip6_hdr)) { DPRINTF(("ah6_input(): bad offset\n")); 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_freem(*mp); *mp = NULL; return IPPROTO_DONE; } protoff += offsetof(struct ip6_ext, ip6e_nxt); } ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto, 0); return IPPROTO_DONE; } /* IPv6 AH callback. */ int ah6_input_cb(struct mbuf *m, int off, int protoff) { int nxt; u_int8_t nxt8; int nest = 0; /* Retrieve new protocol */ m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &nxt8); nxt = nxt8; /* * see the end of ip6_input for this logic. * IPPROTO_IPV[46] case will be processed just like other ones */ while (nxt != IPPROTO_DONE) { if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { ip6stat.ip6s_toomanyhdr++; goto bad; } /* * Protection against faulty packet - there should be * more sanity checks in header chain processing. */ if (m->m_pkthdr.len < off) { ip6stat.ip6s_tooshort++; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); goto bad; } nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); } return 0; bad: m_freem(m); return EINVAL; } /* IPv6 ESP wrapper. */ int esp6_input(struct mbuf **mp, int *offp, int proto) { int l = 0; int protoff, nxt; struct ip6_ext ip6e; if (*offp < sizeof(struct ip6_hdr)) { DPRINTF(("esp6_input(): bad offset\n")); 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_freem(*mp); *mp = NULL; 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 callback */ int esp6_input_cb(struct mbuf *m, int skip, int protoff) { return ah6_input_cb(m, skip, protoff); } /* IPv6 IPcomp wrapper */ int ipcomp6_input(struct mbuf **mp, int *offp, int proto) { int l = 0; int protoff, nxt; struct ip6_ext ip6e; if (*offp < sizeof(struct ip6_hdr)) { DPRINTF(("ipcomp6_input(): bad offset\n")); 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_freem(*mp); *mp = NULL; 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 callback */ int ipcomp6_input_cb(struct mbuf *m, int skip, int protoff) { return ah6_input_cb(m, skip, protoff); } #endif /* INET6 */