/*- * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting * All rights reserved. * * 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. * * $FreeBSD$ */ /* * IPsec output processing. */ #include "opt_inet.h" #include "opt_inet6.h" #include "opt_ipsec.h" #include "opt_enc.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET6 #include #endif #include #ifdef INET6 #include #include #endif #include #ifdef INET6 #include #endif #include #ifdef INET6 #include #endif #include #include #include #include #include #include #include #include #ifdef IPSEC_NAT_T #include #endif #ifdef DEV_ENC #include #endif int ipsec_process_done(struct mbuf *m, struct ipsecrequest *isr) { struct tdb_ident *tdbi; struct m_tag *mtag; struct secasvar *sav; struct secasindex *saidx; int error; IPSEC_ASSERT(m != NULL, ("null mbuf")); IPSEC_ASSERT(isr != NULL, ("null ISR")); sav = isr->sav; IPSEC_ASSERT(sav != NULL, ("null SA")); IPSEC_ASSERT(sav->sah != NULL, ("null SAH")); saidx = &sav->sah->saidx; switch (saidx->dst.sa.sa_family) { #ifdef INET case AF_INET: /* Fix the header length, for AH processing. */ mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len); break; #endif /* INET */ #ifdef INET6 case AF_INET6: /* Fix the header length, for AH processing. */ if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) { error = ENXIO; goto bad; } if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) { /* No jumbogram support. */ error = ENXIO; /*?*/ goto bad; } mtod(m, struct ip6_hdr *)->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); break; #endif /* INET6 */ default: DPRINTF(("%s: unknown protocol family %u\n", __func__, saidx->dst.sa.sa_family)); error = ENXIO; goto bad; } /* * Add a record of what we've done or what needs to be done to the * packet. */ mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE, sizeof(struct tdb_ident), M_NOWAIT); if (mtag == NULL) { DPRINTF(("%s: could not get packet tag\n", __func__)); error = ENOMEM; goto bad; } tdbi = (struct tdb_ident *)(mtag + 1); tdbi->dst = saidx->dst; tdbi->proto = saidx->proto; tdbi->spi = sav->spi; m_tag_prepend(m, mtag); /* * If there's another (bundled) SA to apply, do so. * Note that this puts a burden on the kernel stack size. * If this is a problem we'll need to introduce a queue * to set the packet on so we can unwind the stack before * doing further processing. */ if (isr->next) { /* XXX-BZ currently only support same AF bundles. */ switch (saidx->dst.sa.sa_family) { #ifdef INET case AF_INET: IPSECSTAT_INC(ips_out_bundlesa); return ipsec4_process_packet(m, isr->next); /* NOTREACHED */ #endif #ifdef notyet #ifdef INET6 case AF_INET6: /* XXX */ IPSEC6STAT_INC(ips_out_bundlesa); return ipsec6_process_packet(m, isr->next); /* NOTREACHED */ #endif /* INET6 */ #endif default: DPRINTF(("%s: unknown protocol family %u\n", __func__, saidx->dst.sa.sa_family)); error = ENXIO; goto bad; } } key_sa_recordxfer(sav, m); /* record data transfer */ /* * We're done with IPsec processing, transmit the packet using the * appropriate network protocol (IP or IPv6). SPD lookup will be * performed again there. */ switch (saidx->dst.sa.sa_family) { #ifdef INET case AF_INET: #ifdef IPSEC_NAT_T /* * If NAT-T is enabled, now that all IPsec processing is done * insert UDP encapsulation header after IP header. */ if (sav->natt_type) { struct ip *ip = mtod(m, struct ip *); const int hlen = (ip->ip_hl << 2); int size, off; struct mbuf *mi; struct udphdr *udp; size = sizeof(struct udphdr); if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) { /* * draft-ietf-ipsec-nat-t-ike-0[01].txt and * draft-ietf-ipsec-udp-encaps-(00/)01.txt, * ignoring possible AH mode * non-IKE marker + non-ESP marker * from draft-ietf-ipsec-udp-encaps-00.txt. */ size += sizeof(u_int64_t); } mi = m_makespace(m, hlen, size, &off); if (mi == NULL) { DPRINTF(("%s: m_makespace for udphdr failed\n", __func__)); error = ENOBUFS; goto bad; } udp = (struct udphdr *)(mtod(mi, caddr_t) + off); if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) udp->uh_sport = htons(UDP_ENCAP_ESPINUDP_PORT); else udp->uh_sport = KEY_PORTFROMSADDR(&sav->sah->saidx.src); udp->uh_dport = KEY_PORTFROMSADDR(&sav->sah->saidx.dst); udp->uh_sum = 0; udp->uh_ulen = htons(m->m_pkthdr.len - hlen); ip->ip_len = htons(m->m_pkthdr.len); ip->ip_p = IPPROTO_UDP; if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) *(u_int64_t *)(udp + 1) = 0; } #endif /* IPSEC_NAT_T */ return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL); #endif /* INET */ #ifdef INET6 case AF_INET6: /* * We don't need massage, IPv6 header fields are always in * net endian. */ return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); #endif /* INET6 */ } panic("ipsec_process_done"); bad: m_freem(m); return (error); } static struct ipsecrequest * ipsec_nextisr( struct mbuf *m, struct ipsecrequest *isr, int af, struct secasindex *saidx, int *error ) { #define IPSEC_OSTAT(name) do { \ if (isr->saidx.proto == IPPROTO_ESP) \ ESPSTAT_INC(esps_##name); \ else if (isr->saidx.proto == IPPROTO_AH)\ AHSTAT_INC(ahs_##name); \ else \ IPCOMPSTAT_INC(ipcomps_##name); \ } while (0) struct secasvar *sav; IPSECREQUEST_LOCK_ASSERT(isr); IPSEC_ASSERT(af == AF_INET || af == AF_INET6, ("invalid address family %u", af)); again: /* * Craft SA index to search for proper SA. Note that * we only fillin unspecified SA peers for transport * mode; for tunnel mode they must already be filled in. */ *saidx = isr->saidx; if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) { /* Fillin unspecified SA peers only for transport mode */ if (af == AF_INET) { struct sockaddr_in *sin; struct ip *ip = mtod(m, struct ip *); if (saidx->src.sa.sa_len == 0) { sin = &saidx->src.sin; sin->sin_len = sizeof(*sin); sin->sin_family = AF_INET; sin->sin_port = IPSEC_PORT_ANY; sin->sin_addr = ip->ip_src; } if (saidx->dst.sa.sa_len == 0) { sin = &saidx->dst.sin; sin->sin_len = sizeof(*sin); sin->sin_family = AF_INET; sin->sin_port = IPSEC_PORT_ANY; sin->sin_addr = ip->ip_dst; } } else { struct sockaddr_in6 *sin6; struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); if (saidx->src.sin6.sin6_len == 0) { sin6 = (struct sockaddr_in6 *)&saidx->src; sin6->sin6_len = sizeof(*sin6); sin6->sin6_family = AF_INET6; sin6->sin6_port = IPSEC_PORT_ANY; sin6->sin6_addr = ip6->ip6_src; if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) { /* fix scope id for comparing SPD */ sin6->sin6_addr.s6_addr16[1] = 0; sin6->sin6_scope_id = ntohs(ip6->ip6_src.s6_addr16[1]); } } if (saidx->dst.sin6.sin6_len == 0) { sin6 = (struct sockaddr_in6 *)&saidx->dst; sin6->sin6_len = sizeof(*sin6); sin6->sin6_family = AF_INET6; sin6->sin6_port = IPSEC_PORT_ANY; sin6->sin6_addr = ip6->ip6_dst; if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) { /* fix scope id for comparing SPD */ sin6->sin6_addr.s6_addr16[1] = 0; sin6->sin6_scope_id = ntohs(ip6->ip6_dst.s6_addr16[1]); } } } } /* * Lookup SA and validate it. */ *error = key_checkrequest(isr, saidx); if (*error != 0) { /* * IPsec processing is required, but no SA found. * I assume that key_acquire() had been called * to get/establish the SA. Here I discard * this packet because it is responsibility for * upper layer to retransmit the packet. */ switch(af) { case AF_INET: IPSECSTAT_INC(ips_out_nosa); break; #ifdef INET6 case AF_INET6: IPSEC6STAT_INC(ips_out_nosa); break; #endif } goto bad; } sav = isr->sav; if (sav == NULL) { IPSEC_ASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE, ("no SA found, but required; level %u", ipsec_get_reqlevel(isr))); IPSECREQUEST_UNLOCK(isr); isr = isr->next; /* * If isr is NULL, we found a 'use' policy w/o SA. * Return w/o error and w/o isr so we can drop out * and continue w/o IPsec processing. */ if (isr == NULL) return isr; IPSECREQUEST_LOCK(isr); goto again; } /* * Check system global policy controls. */ if ((isr->saidx.proto == IPPROTO_ESP && !V_esp_enable) || (isr->saidx.proto == IPPROTO_AH && !V_ah_enable) || (isr->saidx.proto == IPPROTO_IPCOMP && !V_ipcomp_enable)) { DPRINTF(("%s: IPsec outbound packet dropped due" " to policy (check your sysctls)\n", __func__)); IPSEC_OSTAT(pdrops); *error = EHOSTUNREACH; goto bad; } /* * Sanity check the SA contents for the caller * before they invoke the xform output method. */ if (sav->tdb_xform == NULL) { DPRINTF(("%s: no transform for SA\n", __func__)); IPSEC_OSTAT(noxform); *error = EHOSTUNREACH; goto bad; } return isr; bad: IPSEC_ASSERT(*error != 0, ("error return w/ no error code")); IPSECREQUEST_UNLOCK(isr); return NULL; #undef IPSEC_OSTAT } static int ipsec_encap(struct mbuf **mp, struct secasindex *saidx) { #ifdef INET6 struct ip6_hdr *ip6; #endif struct ip *ip; int setdf; uint8_t itos, proto; ip = mtod(*mp, struct ip *); switch (ip->ip_v) { #ifdef INET case IPVERSION: proto = IPPROTO_IPIP; /* * Collect IP_DF state from the inner header * and honor system-wide control of how to handle it. */ switch (V_ip4_ipsec_dfbit) { case 0: /* clear in outer header */ case 1: /* set in outer header */ setdf = V_ip4_ipsec_dfbit; break; default:/* propagate to outer header */ setdf = (ip->ip_off & ntohs(IP_DF)) != 0; } itos = ip->ip_tos; break; #endif #ifdef INET6 case (IPV6_VERSION >> 4): proto = IPPROTO_IPV6; ip6 = mtod(*mp, struct ip6_hdr *); itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; setdf = V_ip4_ipsec_dfbit ? 1: 0; /* scoped address handling */ in6_clearscope(&ip6->ip6_src); in6_clearscope(&ip6->ip6_dst); break; #endif default: return (EAFNOSUPPORT); } switch (saidx->dst.sa.sa_family) { #ifdef INET case AF_INET: if (saidx->src.sa.sa_family != AF_INET || saidx->src.sin.sin_addr.s_addr == INADDR_ANY || saidx->dst.sin.sin_addr.s_addr == INADDR_ANY) return (EINVAL); M_PREPEND(*mp, sizeof(struct ip), M_NOWAIT); if (*mp == NULL) return (ENOBUFS); ip = mtod(*mp, struct ip *); ip->ip_v = IPVERSION; ip->ip_hl = sizeof(struct ip) >> 2; ip->ip_p = proto; ip->ip_len = htons((*mp)->m_pkthdr.len); ip->ip_ttl = V_ip_defttl; ip->ip_sum = 0; ip->ip_off = setdf ? htons(IP_DF): 0; ip->ip_src = saidx->src.sin.sin_addr; ip->ip_dst = saidx->dst.sin.sin_addr; ip_ecn_ingress(V_ip4_ipsec_ecn, &ip->ip_tos, &itos); ip_fillid(ip); break; #endif /* INET */ #ifdef INET6 case AF_INET6: if (saidx->src.sa.sa_family != AF_INET6 || IN6_IS_ADDR_UNSPECIFIED(&saidx->src.sin6.sin6_addr) || IN6_IS_ADDR_UNSPECIFIED(&saidx->dst.sin6.sin6_addr)) return (EINVAL); M_PREPEND(*mp, sizeof(struct ip6_hdr), M_NOWAIT); if (*mp == NULL) return (ENOBUFS); ip6 = mtod(*mp, struct ip6_hdr *); ip6->ip6_flow = 0; ip6->ip6_vfc = IPV6_VERSION; ip6->ip6_hlim = V_ip6_defhlim; ip6->ip6_nxt = proto; ip6->ip6_dst = saidx->dst.sin6.sin6_addr; /* For link-local address embed scope zone id */ if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) ip6->ip6_dst.s6_addr16[1] = htons(saidx->dst.sin6.sin6_scope_id & 0xffff); ip6->ip6_src = saidx->src.sin6.sin6_addr; if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) ip6->ip6_src.s6_addr16[1] = htons(saidx->src.sin6.sin6_scope_id & 0xffff); ip6->ip6_plen = htons((*mp)->m_pkthdr.len - sizeof(*ip6)); ip_ecn_ingress(V_ip6_ipsec_ecn, &proto, &itos); ip6->ip6_flow |= htonl((uint32_t)proto << 20); break; #endif /* INET6 */ default: return (EAFNOSUPPORT); } return (0); } #ifdef INET /* * IPsec output logic for IPv4. */ int ipsec4_process_packet(struct mbuf *m, struct ipsecrequest *isr) { char sbuf[INET6_ADDRSTRLEN], dbuf[INET6_ADDRSTRLEN]; union sockaddr_union *dst; struct secasindex saidx; struct secasvar *sav; struct ip *ip; int error, i, off; IPSEC_ASSERT(m != NULL, ("null mbuf")); IPSEC_ASSERT(isr != NULL, ("null isr")); IPSECREQUEST_LOCK(isr); /* insure SA contents don't change */ isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error); if (isr == NULL) { if (error != 0) goto bad; return EJUSTRETURN; } sav = isr->sav; if (m->m_len < sizeof(struct ip) && (m = m_pullup(m, sizeof (struct ip))) == NULL) { error = ENOBUFS; goto bad; } ip = mtod(m, struct ip *); dst = &sav->sah->saidx.dst; #ifdef DEV_ENC if_inc_counter(encif, IFCOUNTER_OPACKETS, 1); if_inc_counter(encif, IFCOUNTER_OBYTES, m->m_pkthdr.len); /* pass the mbuf to enc0 for bpf processing */ ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_BEFORE); /* pass the mbuf to enc0 for packet filtering */ if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0) goto bad; #endif /* Do the appropriate encapsulation, if necessary */ if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */ dst->sa.sa_family != AF_INET || /* PF mismatch */ (dst->sa.sa_family == AF_INET && /* Proxy */ dst->sin.sin_addr.s_addr != INADDR_ANY && dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) { /* Fix IPv4 header checksum and length */ ip->ip_len = htons(m->m_pkthdr.len); ip->ip_sum = 0; ip->ip_sum = in_cksum(m, ip->ip_hl << 2); error = ipsec_encap(&m, &sav->sah->saidx); if (error != 0) { DPRINTF(("%s: encapsulation for SA %s->%s " "SPI 0x%08x failed with error %d\n", __func__, ipsec_address(&sav->sah->saidx.src, sbuf, sizeof(sbuf)), ipsec_address(&sav->sah->saidx.dst, dbuf, sizeof(dbuf)), ntohl(sav->spi), error)); goto bad; } } #ifdef DEV_ENC /* pass the mbuf to enc0 for bpf processing */ ipsec_bpf(m, sav, sav->sah->saidx.dst.sa.sa_family, ENC_OUT|ENC_AFTER); /* pass the mbuf to enc0 for packet filtering */ if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0) goto bad; #endif /* * Dispatch to the appropriate IPsec transform logic. The * packet will be returned for transmission after crypto * processing, etc. are completed. * * NB: m & sav are ``passed to caller'' who's reponsible for * for reclaiming their resources. */ switch(dst->sa.sa_family) { case AF_INET: ip = mtod(m, struct ip *); i = ip->ip_hl << 2; off = offsetof(struct ip, ip_p); break; #ifdef INET6 case AF_INET6: i = sizeof(struct ip6_hdr); off = offsetof(struct ip6_hdr, ip6_nxt); break; #endif /* INET6 */ default: DPRINTF(("%s: unsupported protocol family %u\n", __func__, dst->sa.sa_family)); error = EPFNOSUPPORT; IPSECSTAT_INC(ips_out_inval); goto bad; } error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off); IPSECREQUEST_UNLOCK(isr); return (error); bad: if (isr) IPSECREQUEST_UNLOCK(isr); if (m) m_freem(m); return error; } #endif #ifdef INET6 static int in6_sa_equal_addrwithscope(const struct sockaddr_in6 *sa, const struct in6_addr *ia) { struct in6_addr ia2; memcpy(&ia2, &sa->sin6_addr, sizeof(ia2)); if (IN6_IS_SCOPE_LINKLOCAL(&sa->sin6_addr)) ia2.s6_addr16[1] = htons(sa->sin6_scope_id); return IN6_ARE_ADDR_EQUAL(ia, &ia2); } /* * IPsec output logic for IPv6. */ int ipsec6_process_packet(struct mbuf *m, struct ipsecrequest *isr) { char sbuf[INET6_ADDRSTRLEN], dbuf[INET6_ADDRSTRLEN]; struct secasindex saidx; struct secasvar *sav; struct ip6_hdr *ip6; int error, i, off; union sockaddr_union *dst; IPSEC_ASSERT(m != NULL, ("ipsec6_process_packet: null mbuf")); IPSEC_ASSERT(isr != NULL, ("ipsec6_process_packet: null isr")); IPSECREQUEST_LOCK(isr); /* insure SA contents don't change */ isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error); if (isr == NULL) { if (error != 0) goto bad; return EJUSTRETURN; } sav = isr->sav; dst = &sav->sah->saidx.dst; ip6 = mtod(m, struct ip6_hdr *); ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6)); #ifdef DEV_ENC if_inc_counter(encif, IFCOUNTER_OPACKETS, 1); if_inc_counter(encif, IFCOUNTER_OBYTES, m->m_pkthdr.len); /* pass the mbuf to enc0 for bpf processing */ ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_BEFORE); /* pass the mbuf to enc0 for packet filtering */ if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0) goto bad; #endif /* DEV_ENC */ /* Do the appropriate encapsulation, if necessary */ if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */ dst->sa.sa_family != AF_INET6 || /* PF mismatch */ ((dst->sa.sa_family == AF_INET6) && (!IN6_IS_ADDR_UNSPECIFIED(&dst->sin6.sin6_addr)) && (!in6_sa_equal_addrwithscope(&dst->sin6, &ip6->ip6_dst)))) { if (m->m_pkthdr.len - sizeof(*ip6) > IPV6_MAXPACKET) { /* No jumbogram support. */ error = ENXIO; /*XXX*/ goto bad; } error = ipsec_encap(&m, &sav->sah->saidx); if (error != 0) { DPRINTF(("%s: encapsulation for SA %s->%s " "SPI 0x%08x failed with error %d\n", __func__, ipsec_address(&sav->sah->saidx.src, sbuf, sizeof(sbuf)), ipsec_address(&sav->sah->saidx.dst, dbuf, sizeof(dbuf)), ntohl(sav->spi), error)); goto bad; } } #ifdef DEV_ENC ipsec_bpf(m, isr->sav, dst->sa.sa_family, ENC_OUT|ENC_AFTER); /* pass the mbuf to enc0 for packet filtering */ if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0) goto bad; #endif /* DEV_ENC */ switch(dst->sa.sa_family) { #ifdef INET case AF_INET: { struct ip *ip; ip = mtod(m, struct ip *); i = ip->ip_hl << 2; off = offsetof(struct ip, ip_p); } break; #endif /* AF_INET */ case AF_INET6: i = sizeof(struct ip6_hdr); off = offsetof(struct ip6_hdr, ip6_nxt); break; default: DPRINTF(("%s: unsupported protocol family %u\n", __func__, dst->sa.sa_family)); error = EPFNOSUPPORT; IPSEC6STAT_INC(ips_out_inval); goto bad; } error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off); IPSECREQUEST_UNLOCK(isr); return error; bad: if (isr) IPSECREQUEST_UNLOCK(isr); if (m) m_freem(m); return error; } #endif /*INET6*/