/* $OpenBSD: ipsec_input.c,v 1.32 2000/09/19 03:20:59 angelos 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. * * Permission to use, copy, and modify this software 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET6 #ifndef INET #include #endif #include #include #include #endif /* INET6 */ #include #include #include #include #include "bpfilter.h" #define PI_MAGIC 0xdeadbeef /* XXX horror! */ int ipsec_common_input(struct mbuf *, int, int, int, int); #ifdef ENCDEBUG #define DPRINTF(x) if (encdebug) printf x #else #define DPRINTF(x) #endif #ifndef offsetof #define offsetof(s, e) ((int)&((s *)0)->e) #endif /* sysctl variables */ int esp_enable = 0; int ah_enable = 0; #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) { #define IPSEC_ISTAT(y,z) (sproto == IPPROTO_ESP ? (y)++ : (z)++) union sockaddr_union dst_address; struct tdb *tdbp; u_int32_t spi; int s; IPSEC_ISTAT(espstat.esps_input, ahstat.ahs_input); if (m == 0) { DPRINTF(("%s: NULL packet received\n")); IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops); return EINVAL; } if ((sproto == IPPROTO_ESP && !esp_enable) || (sproto == IPPROTO_AH && !ah_enable)) { m_freem(m); IPSEC_ISTAT(espstat.esps_pdrops, ahstat.ahs_pdrops); return EOPNOTSUPP; } if (m->m_pkthdr.len - skip < 2 * sizeof(u_int32_t)) { m_freem(m); IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops); 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 m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t), (caddr_t) &spi); /* * 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)); 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); 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); 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); 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); return ENXIO; } if (tdbp->tdb_dst.sa.sa_family == AF_INET) { /* * XXX The fragment conflicts with scoped nature of IPv6, so do it for * only for IPv4 for now. */ if (tdbp->tdb_interface) m->m_pkthdr.rcvif = (struct ifnet *) tdbp->tdb_interface; else 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.tv_sec; tdb_expiration(tdbp, TDBEXP_TIMEOUT); } /* * Call appropriate transform and return -- callback takes care of * everything else. */ if ((*(tdbp->tdb_xform->xf_input))(m, tdbp, skip, protoff) == NULL) { splx(s); return EINVAL; } else { splx(s); return 0; } } /* * 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) { 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 */ af = tdbp->tdb_dst.sa.sa_family; sproto = tdbp->tdb_sproto; /* Sanity check */ if (m == NULL) { /* The called routine will print a message if necessary */ IPSEC_ISTAT(espstat.esps_badkcr, ahstat.ahs_badkcr); return EINVAL; } #ifdef INET /* Fix IPv4 header */ if (tdbp->tdb_dst.sa.sa_family == AF_INET) { if ((m = m_pullup(m, skip)) == 0) { 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); return ENOBUFS; } ip = mtod(m, struct ip *); ip->ip_len = htons(m->m_pkthdr.len); HTONS(ip->ip_id); HTONS(ip->ip_off); 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) { /* ipn will now contain the inner IPv4 header */ m_copydata(m, ip->ip_hl << 2, 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); return EACCES; } } #if INET6 /* IPv6-in-IP encapsulation */ if (prot == IPPROTO_IPV6) { /* ip6n will now contain the inner IPv6 header */ m_copydata(m, ip->ip_hl << 2, 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); return EACCES; } } #endif /* INET6 */ /* * Check that the source address is an expected one, if we know what * it's supposed to be. This avoids source address spoofing. */ if (((tdbp->tdb_src.sa.sa_family == AF_INET) && (tdbp->tdb_src.sin.sin_addr.s_addr != INADDR_ANY) && (ip->ip_src.s_addr != tdbp->tdb_src.sin.sin_addr.s_addr)) || ((tdbp->tdb_src.sa.sa_family != AF_INET) && (tdbp->tdb_src.sa.sa_family != 0))) { DPRINTF(("ipsec_common_input_cb(): source address %s doesn't correspond to expected source %s, SA %s/%08x\n", inet_ntoa4(ip->ip_src), ipsp_address(tdbp->tdb_src), ipsp_address(tdbp->tdb_dst), ntohl(tdbp->tdb_spi))); m_freem(m); IPSEC_ISTAT(espstat.esps_pdrops, ahstat.ahs_pdrops); return EACCES; } } #endif /* INET */ #ifdef INET6 /* Fix IPv6 header */ if (af == INET6) { if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == 0) { 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); 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) { /* 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); return EACCES; } } #endif /* INET */ /* IPv6-in-IP encapsulation */ if (prot == IPPROTO_IPV6) { /* 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); return EACCES; } } /* * Check that the source address is an expected one, if we know what * it's supposed to be. This avoids source address spoofing. */ if (((tdbp->tdb_src.sa.sa_family == AF_INET6) && !IN6_IS_ADDR_UNSPECIFIED(&tdbp->tdb_src.sin6.sin6_addr) && !IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, &tdbp->tdb_src.sin6.sin6_addr)) || ((tdbp->tdb_src.sa.sa_family != AF_INET6) && (tdbp->tdb_src.sa.sa_family != 0))) { DPRINTF(("ipsec_common_input_cb(): packet %s to %s does not match any ACL entries, SA %s/%08x\n", ip6_sprintf(&ip6->ip6_src), ip6_sprintf(&ip6->ip6_dst), ipsp_address(tdbp->tdb_src), ipsp_address(tdbp->tdb_dst), ntohl(tdbp->tdb_spi))); m_freem(m); IPSEC_ISTAT(espstat.esps_pdrops, ahstat.ahs_pdrops); return EACCES; } } #endif /* INET6 */ /* * Record what we've done to the packet (under what SA it was * processed). */ if (m->m_pkthdr.tdbi && m->m_pkthdr.tdbi != (void *) PI_MAGIC) free(m->m_pkthdr.tdbi, M_TEMP); MALLOC(m->m_pkthdr.tdbi, void *, sizeof(struct tdb_ident), M_TEMP, M_NOWAIT); if (m->m_pkthdr.tdbi == NULL) { m_freem(m); IPSEC_ISTAT(espstat.esps_hdrops, ahstat.ahs_hdrops); return ENOMEM; } bcopy(&tdbp->tdb_dst, &(((struct tdb_ident *) m->m_pkthdr.tdbi)->dst), sizeof(union sockaddr_union)); ((struct tdb_ident *) m->m_pkthdr.tdbi)->proto = tdbp->tdb_sproto; ((struct tdb_ident *) m->m_pkthdr.tdbi)->spi = tdbp->tdb_spi; 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 m->m_flags |= M_AUTH; #if NBPFILTER > 0 if (tdbp->tdb_interface) bpfif = (struct ifnet *) tdbp->tdb_interface; else bpfif = &encif[0].sc_if; if (bpfif->if_bpf) { /* * We need to prepend the address family as * a four byte field. Cons up a dummy header * to pacify bpf. This is safe because bpf * will only read from the mbuf (i.e., it won't * try to free it or keep a pointer a to it). */ struct mbuf m1; struct enchdr hdr; hdr.af = af; hdr.spi = tdbp->tdb_spi; hdr.flags = m->m_flags & (M_AUTH|M_CONF); m1.m_next = m; m1.m_len = ENC_HDRLEN; m1.m_data = (char *) &hdr; bpf_mtap(bpfif->if_bpf, &m1); } #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); 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); 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 *oldlen, void *newp, size_t newlen) { /* All sysctl names at this level are terminal. */ if (namelen != 1) return ENOTDIR; switch (name[0]) { case ESPCTL_ENABLE: return sysctl_int(oldp, oldlen, newp, newlen, &esp_enable); default: return ENOPROTOOPT; } /* NOTREACHED */ } int ah_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlen, void *newp, size_t newlen) { /* All sysctl names at this level are terminal. */ if (namelen != 1) return ENOTDIR; switch (name[0]) { case AHCTL_ENABLE: return sysctl_int(oldp, oldlen, newp, newlen, &ah_enable); default: return ENOPROTOOPT; } /* NOTREACHED */ } #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); return; } /* IPv4 AH callback */ int ah4_input_cb(struct mbuf *m, ...) { struct ifqueue *ifq = &ipintrq; /* * Interface pointer is already in first mbuf; chop off the * `outer' header and reschedule. */ if (IF_QFULL(ifq)) { IF_DROP(ifq); if (m->m_pkthdr.tdbi && m->m_pkthdr.tdbi != (void *) PI_MAGIC) free(m->m_pkthdr.tdbi, M_TEMP); m_freem(m); ahstat.ahs_qfull++; DPRINTF(("ah4_input_cb(): dropped packet because of full IP queue\n")); return ENOBUFS; } IF_ENQUEUE(ifq, m); schednetisr(NETISR_IP); return 0; } /* 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); } /* IPv4 ESP callback */ int esp4_input_cb(struct mbuf *m, ...) { struct ifqueue *ifq = &ipintrq; /* * Interface pointer is already in first mbuf; chop off the * `outer' header and reschedule. */ if (IF_QFULL(ifq)) { IF_DROP(ifq); if (m->m_pkthdr.tdbi && m->m_pkthdr.tdbi != (void *) PI_MAGIC) free(m->m_pkthdr.tdbi, M_TEMP); m_freem(m); espstat.esps_qfull++; DPRINTF(("esp4_input_cb(): dropped packet because of full IP queue\n")); return ENOBUFS; } IF_ENQUEUE(ifq, m); schednetisr(NETISR_IP); return 0; } #endif /* INET */ #ifdef INET6 /* IPv6 AH wrapper */ int ah6_input(struct mbuf **mp, int *offp, int proto) { int l = 0; int protoff; 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); do { protoff += l; m_copydata(*mp, protoff, sizeof(ip6e), (caddr_t) &ip6e); if (ip6e.ip6e_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 } 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); 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: if (m->m_pkthdr.tdbi && m->m_pkthdr.tdbi != (void *) PI_MAGIC) free(m->m_pkthdr.tdbi, M_TEMP); m_freem(m); return EINVAL; } /* IPv6 ESP wrapper */ int esp6_input(struct mbuf **mp, int *offp, int proto) { int l = 0; int protoff; 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); do { protoff += l; m_copydata(*mp, protoff, sizeof(ip6e), (caddr_t) &ip6e); if (ip6e.ip6e_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 } 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); return IPPROTO_DONE; } /* IPv6 ESP callback */ int esp6_input_cb(struct mbuf *m, int skip, int protoff) { return ah6_input_cb(m, skip, protoff); } #endif /* INET6 */