/*- * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting * Copyright (c) 2016 Andrey V. Elsukov <ae@FreeBSD.org> * 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_sctp.h" #include <sys/param.h> #include <sys/systm.h> #include <sys/mbuf.h> #include <sys/domain.h> #include <sys/protosw.h> #include <sys/socket.h> #include <sys/errno.h> #include <sys/hhook.h> #include <sys/syslog.h> #include <net/if.h> #include <net/if_enc.h> #include <net/if_var.h> #include <net/vnet.h> #include <netinet/in.h> #include <netinet/in_systm.h> #include <netinet/ip.h> #include <netinet/ip_var.h> #include <netinet/in_var.h> #include <netinet/ip_ecn.h> #ifdef INET6 #include <netinet6/ip6_ecn.h> #endif #include <netinet/ip6.h> #ifdef INET6 #include <netinet6/ip6_var.h> #include <netinet6/scope6_var.h> #endif #include <netinet/in_pcb.h> #ifdef INET6 #include <netinet/icmp6.h> #endif #ifdef SCTP #include <netinet/sctp_crc32.h> #endif #include <netinet/udp.h> #include <netipsec/ah.h> #include <netipsec/esp.h> #include <netipsec/ipsec.h> #ifdef INET6 #include <netipsec/ipsec6.h> #endif #include <netipsec/ah_var.h> #include <netipsec/esp_var.h> #include <netipsec/ipcomp_var.h> #include <netipsec/xform.h> #include <netipsec/key.h> #include <netipsec/keydb.h> #include <netipsec/key_debug.h> #include <machine/in_cksum.h> #define IPSEC_OSTAT_INC(proto, name) do { \ if ((proto) == IPPROTO_ESP) \ ESPSTAT_INC(esps_##name); \ else if ((proto) == IPPROTO_AH)\ AHSTAT_INC(ahs_##name); \ else \ IPCOMPSTAT_INC(ipcomps_##name); \ } while (0) static int ipsec_encap(struct mbuf **mp, struct secasindex *saidx); #ifdef INET static struct secasvar * ipsec4_allocsa(struct mbuf *m, struct secpolicy *sp, u_int *pidx, int *error) { struct secasindex *saidx, tmpsaidx; struct ipsecrequest *isr; struct sockaddr_in *sin; struct secasvar *sav; struct ip *ip; /* * Check system global policy controls. */ next: isr = sp->req[*pidx]; 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_INC(isr->saidx.proto, pdrops); *error = EHOSTUNREACH; return (NULL); } /* * Craft SA index to search for proper SA. Note that * we only initialize unspecified SA peers for transport * mode; for tunnel mode they must already be filled in. */ if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) { saidx = &tmpsaidx; *saidx = isr->saidx; 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 saidx = &sp->req[*pidx]->saidx; /* * Lookup SA and validate it. */ sav = key_allocsa_policy(sp, saidx, error); if (sav == NULL) { IPSECSTAT_INC(ips_out_nosa); if (*error != 0) return (NULL); if (ipsec_get_reqlevel(sp, *pidx) != IPSEC_LEVEL_REQUIRE) { /* * We have no SA and policy that doesn't require * this IPsec transform, thus we can continue w/o * IPsec processing, i.e. return EJUSTRETURN. * But first check if there is some bundled transform. */ if (sp->tcount > ++(*pidx)) goto next; *error = EJUSTRETURN; } return (NULL); } IPSEC_ASSERT(sav->tdb_xform != NULL, ("SA with NULL tdb_xform")); return (sav); } /* * IPsec output logic for IPv4. */ static int ipsec4_perform_request(struct mbuf *m, struct secpolicy *sp, struct inpcb *inp, u_int idx) { struct ipsec_ctx_data ctx; union sockaddr_union *dst; struct secasvar *sav; struct ip *ip; int error, i, off; IPSEC_ASSERT(idx < sp->tcount, ("Wrong IPsec request index %d", idx)); /* * We hold the reference to SP. Content of SP couldn't be changed. * Craft secasindex and do lookup for suitable SA. * Then do encapsulation if needed and call xform's output. * We need to store SP in the xform callback parameters. * In xform callback we will extract SP and it can be used to * determine next transform. At the end of transform we can * release reference to SP. */ sav = ipsec4_allocsa(m, sp, &idx, &error); if (sav == NULL) { if (error == EJUSTRETURN) { /* No IPsec required */ key_freesp(&sp); return (error); } goto bad; } /* * XXXAE: most likely ip_sum at this point is wrong. */ IPSEC_INIT_CTX(&ctx, &m, inp, sav, AF_INET, IPSEC_ENC_BEFORE); if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_OUT)) != 0) goto bad; ip = mtod(m, struct ip *); dst = &sav->sah->saidx.dst; /* Do the appropriate encapsulation, if necessary */ if (sp->req[idx]->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 SPI 0x%08x failed " "with error %d\n", __func__, ntohl(sav->spi), error)); /* XXXAE: IPSEC_OSTAT_INC(tunnel); */ goto bad; } inp = NULL; } IPSEC_INIT_CTX(&ctx, &m, inp, sav, dst->sa.sa_family, IPSEC_ENC_AFTER); if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_OUT)) != 0) goto bad; /* * 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 responsible 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; IPSEC_OSTAT_INC(sav->sah->saidx.proto, nopf); goto bad; } error = (*sav->tdb_xform->xf_output)(m, sp, sav, idx, i, off); return (error); bad: IPSECSTAT_INC(ips_out_inval); if (m != NULL) m_freem(m); if (sav != NULL) key_freesav(&sav); key_freesp(&sp); return (error); } int ipsec4_process_packet(struct mbuf *m, struct secpolicy *sp, struct inpcb *inp) { return (ipsec4_perform_request(m, sp, inp, 0)); } static int ipsec4_common_output(struct mbuf *m, struct inpcb *inp, int forwarding) { struct secpolicy *sp; int error; /* Lookup for the corresponding outbound security policy */ sp = ipsec4_checkpolicy(m, inp, &error, !forwarding); if (sp == NULL) { if (error == -EINVAL) { /* Discarded by policy. */ m_freem(m); return (EACCES); } return (0); /* No IPsec required. */ } /* * Usually we have to have tunnel mode IPsec security policy * when we are forwarding a packet. Otherwise we could not handle * encrypted replies, because they are not destined for us. But * some users are doing source address translation for forwarded * packets, and thus, even if they are forwarded, the replies will * return back to us. */ if (!forwarding) { /* * Do delayed checksums now because we send before * this is done in the normal processing path. */ if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { in_delayed_cksum(m); m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA; } #ifdef SCTP if (m->m_pkthdr.csum_flags & CSUM_SCTP) { struct ip *ip = mtod(m, struct ip *); sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2)); m->m_pkthdr.csum_flags &= ~CSUM_SCTP; } #endif } /* NB: callee frees mbuf and releases reference to SP */ error = ipsec4_process_packet(m, sp, inp); if (error == EJUSTRETURN) { /* * We had a SP with a level of 'use' and no SA. We * will just continue to process the packet without * IPsec processing and return without error. */ return (0); } if (error == 0) return (EINPROGRESS); /* consumed by IPsec */ return (error); } /* * IPSEC_OUTPUT() method implementation for IPv4. * 0 - no IPsec handling needed * other values - mbuf consumed by IPsec. */ int ipsec4_output(struct mbuf *m, struct inpcb *inp) { /* * If the packet is resubmitted to ip_output (e.g. after * AH, ESP, etc. processing), there will be a tag to bypass * the lookup and related policy checking. */ if (m_tag_find(m, PACKET_TAG_IPSEC_OUT_DONE, NULL) != NULL) return (0); return (ipsec4_common_output(m, inp, 0)); } /* * IPSEC_FORWARD() method implementation for IPv4. * 0 - no IPsec handling needed * other values - mbuf consumed by IPsec. */ int ipsec4_forward(struct mbuf *m) { /* * Check if this packet has an active inbound SP and needs to be * dropped instead of forwarded. */ if (ipsec4_in_reject(m, NULL) != 0) { m_freem(m); return (EACCES); } return (ipsec4_common_output(m, NULL, 1)); } #endif #ifdef INET6 static int in6_sa_equal_addrwithscope(const struct sockaddr_in6 *sa, const struct in6_addr *ia) { struct in6_addr ia2; if (IN6_IS_SCOPE_LINKLOCAL(&sa->sin6_addr)) { memcpy(&ia2, &sa->sin6_addr, sizeof(ia2)); ia2.s6_addr16[1] = htons(sa->sin6_scope_id); return (IN6_ARE_ADDR_EQUAL(ia, &ia2)); } return (IN6_ARE_ADDR_EQUAL(&sa->sin6_addr, ia)); } static struct secasvar * ipsec6_allocsa(struct mbuf *m, struct secpolicy *sp, u_int *pidx, int *error) { struct secasindex *saidx, tmpsaidx; struct ipsecrequest *isr; struct sockaddr_in6 *sin6; struct secasvar *sav; struct ip6_hdr *ip6; /* * Check system global policy controls. */ next: isr = sp->req[*pidx]; 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_INC(isr->saidx.proto, pdrops); *error = EHOSTUNREACH; return (NULL); } /* * 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. */ if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) { saidx = &tmpsaidx; *saidx = isr->saidx; 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]); } } } else saidx = &sp->req[*pidx]->saidx; /* * Lookup SA and validate it. */ sav = key_allocsa_policy(sp, saidx, error); if (sav == NULL) { IPSEC6STAT_INC(ips_out_nosa); if (*error != 0) return (NULL); if (ipsec_get_reqlevel(sp, *pidx) != IPSEC_LEVEL_REQUIRE) { /* * We have no SA and policy that doesn't require * this IPsec transform, thus we can continue w/o * IPsec processing, i.e. return EJUSTRETURN. * But first check if there is some bundled transform. */ if (sp->tcount > ++(*pidx)) goto next; *error = EJUSTRETURN; } return (NULL); } IPSEC_ASSERT(sav->tdb_xform != NULL, ("SA with NULL tdb_xform")); return (sav); } /* * IPsec output logic for IPv6. */ static int ipsec6_perform_request(struct mbuf *m, struct secpolicy *sp, struct inpcb *inp, u_int idx) { struct ipsec_ctx_data ctx; union sockaddr_union *dst; struct secasvar *sav; struct ip6_hdr *ip6; int error, i, off; IPSEC_ASSERT(idx < sp->tcount, ("Wrong IPsec request index %d", idx)); sav = ipsec6_allocsa(m, sp, &idx, &error); if (sav == NULL) { if (error == EJUSTRETURN) { /* No IPsec required */ key_freesp(&sp); return (error); } goto bad; } /* Fix IP length in case if it is not set yet. */ ip6 = mtod(m, struct ip6_hdr *); ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6)); IPSEC_INIT_CTX(&ctx, &m, inp, sav, AF_INET6, IPSEC_ENC_BEFORE); if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_OUT)) != 0) goto bad; ip6 = mtod(m, struct ip6_hdr *); /* pfil can change mbuf */ dst = &sav->sah->saidx.dst; /* Do the appropriate encapsulation, if necessary */ if (sp->req[idx]->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 SPI 0x%08x failed " "with error %d\n", __func__, ntohl(sav->spi), error)); /* XXXAE: IPSEC_OSTAT_INC(tunnel); */ goto bad; } inp = NULL; } IPSEC_INIT_CTX(&ctx, &m, inp, sav, dst->sa.sa_family, IPSEC_ENC_AFTER); if ((error = ipsec_run_hhooks(&ctx, HHOOK_TYPE_IPSEC_OUT)) != 0) goto bad; 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; IPSEC_OSTAT_INC(sav->sah->saidx.proto, nopf); goto bad; } error = (*sav->tdb_xform->xf_output)(m, sp, sav, idx, i, off); return (error); bad: IPSEC6STAT_INC(ips_out_inval); if (m != NULL) m_freem(m); if (sav != NULL) key_freesav(&sav); key_freesp(&sp); return (error); } int ipsec6_process_packet(struct mbuf *m, struct secpolicy *sp, struct inpcb *inp) { return (ipsec6_perform_request(m, sp, inp, 0)); } static int ipsec6_common_output(struct mbuf *m, struct inpcb *inp, int forwarding) { struct secpolicy *sp; int error; /* Lookup for the corresponding outbound security policy */ sp = ipsec6_checkpolicy(m, inp, &error, !forwarding); if (sp == NULL) { if (error == -EINVAL) { /* Discarded by policy. */ m_freem(m); return (EACCES); } return (0); /* No IPsec required. */ } if (!forwarding) { /* * Do delayed checksums now because we send before * this is done in the normal processing path. */ if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) { in6_delayed_cksum(m, m->m_pkthdr.len - sizeof(struct ip6_hdr), sizeof(struct ip6_hdr)); m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6; } #ifdef SCTP if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) { sctp_delayed_cksum(m, sizeof(struct ip6_hdr)); m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6; } #endif } /* NB: callee frees mbuf and releases reference to SP */ error = ipsec6_process_packet(m, sp, inp); if (error == EJUSTRETURN) { /* * We had a SP with a level of 'use' and no SA. We * will just continue to process the packet without * IPsec processing and return without error. */ return (0); } if (error == 0) return (EINPROGRESS); /* consumed by IPsec */ return (error); } /* * IPSEC_OUTPUT() method implementation for IPv6. * 0 - no IPsec handling needed * other values - mbuf consumed by IPsec. */ int ipsec6_output(struct mbuf *m, struct inpcb *inp) { /* * If the packet is resubmitted to ip_output (e.g. after * AH, ESP, etc. processing), there will be a tag to bypass * the lookup and related policy checking. */ if (m_tag_find(m, PACKET_TAG_IPSEC_OUT_DONE, NULL) != NULL) return (0); return (ipsec6_common_output(m, inp, 0)); } /* * IPSEC_FORWARD() method implementation for IPv6. * 0 - no IPsec handling needed * other values - mbuf consumed by IPsec. */ int ipsec6_forward(struct mbuf *m) { /* * Check if this packet has an active inbound SP and needs to be * dropped instead of forwarded. */ if (ipsec6_in_reject(m, NULL) != 0) { m_freem(m); return (EACCES); } return (ipsec6_common_output(m, NULL, 1)); } #endif /* INET6 */ int ipsec_process_done(struct mbuf *m, struct secpolicy *sp, struct secasvar *sav, u_int idx) { struct xform_history *xh; struct secasindex *saidx; struct m_tag *mtag; int error; 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 to the packet. */ mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE, sizeof(*xh), M_NOWAIT); if (mtag == NULL) { DPRINTF(("%s: could not get packet tag\n", __func__)); error = ENOMEM; goto bad; } xh = (struct xform_history *)(mtag + 1); xh->dst = saidx->dst; xh->proto = saidx->proto; xh->mode = saidx->mode; xh->spi = sav->spi; m_tag_prepend(m, mtag); key_sa_recordxfer(sav, m); /* record data transfer */ /* * 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 (++idx < sp->tcount) { switch (saidx->dst.sa.sa_family) { #ifdef INET case AF_INET: key_freesav(&sav); IPSECSTAT_INC(ips_out_bundlesa); return (ipsec4_perform_request(m, sp, NULL, idx)); /* NOTREACHED */ #endif #ifdef INET6 case AF_INET6: key_freesav(&sav); IPSEC6STAT_INC(ips_out_bundlesa); return (ipsec6_perform_request(m, sp, NULL, idx)); /* NOTREACHED */ #endif /* INET6 */ default: DPRINTF(("%s: unknown protocol family %u\n", __func__, saidx->dst.sa.sa_family)); error = EPFNOSUPPORT; goto bad; } } key_freesp(&sp), sp = NULL; /* Release reference to SP */ #ifdef INET /* * Do UDP encapsulation if SA requires it. */ if (sav->natt != NULL) { error = udp_ipsec_output(m, sav); if (error != 0) goto bad; } #endif /* INET */ /* * We're done with IPsec processing, transmit the packet using the * appropriate network protocol (IP or IPv6). */ switch (saidx->dst.sa.sa_family) { #ifdef INET case AF_INET: key_freesav(&sav); return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL); #endif /* INET */ #ifdef INET6 case AF_INET6: key_freesav(&sav); return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); #endif /* INET6 */ } panic("ipsec_process_done"); bad: m_freem(m); key_freesav(&sav); if (sp != NULL) key_freesp(&sp); return (error); } /* * ipsec_prepend() is optimized version of M_PREPEND(). * ipsec_encap() is called by IPsec output routine for tunnel mode SA. * It is expected that after IP encapsulation some IPsec transform will * be performed. Each IPsec transform inserts its variable length header * just after outer IP header using m_makespace(). If given mbuf has not * enough free space at the beginning, we allocate new mbuf and reserve * some space at the beginning and at the end. * This helps avoid allocating of new mbuf and data copying in m_makespace(), * we place outer header in the middle of mbuf's data with reserved leading * and trailing space: * [ LEADINGSPACE ][ Outer IP header ][ TRAILINGSPACE ] * LEADINGSPACE will be used to add ethernet header, TRAILINGSPACE will * be used to inject AH/ESP/IPCOMP header. */ #define IPSEC_TRAILINGSPACE (sizeof(struct udphdr) +/* NAT-T */ \ max(sizeof(struct newesp) + EALG_MAX_BLOCK_LEN, /* ESP + IV */ \ sizeof(struct newah) + HASH_MAX_LEN /* AH + ICV */)) static struct mbuf * ipsec_prepend(struct mbuf *m, int len, int how) { struct mbuf *n; M_ASSERTPKTHDR(m); IPSEC_ASSERT(len < MHLEN, ("wrong length")); if (M_LEADINGSPACE(m) >= len) { /* No need to allocate new mbuf. */ m->m_data -= len; m->m_len += len; m->m_pkthdr.len += len; return (m); } n = m_gethdr(how, m->m_type); if (n == NULL) { m_freem(m); return (NULL); } m_move_pkthdr(n, m); n->m_next = m; if (len + IPSEC_TRAILINGSPACE < M_SIZE(n)) m_align(n, len + IPSEC_TRAILINGSPACE); n->m_len = len; n->m_pkthdr.len += len; return (n); } 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 & htons(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); *mp = ipsec_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); *mp = ipsec_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); } (*mp)->m_flags &= ~(M_BCAST | M_MCAST); return (0); }