/* $NetBSD: esp_input.c,v 1.1.1.1 2000/06/14 19:39:43 thorpej Exp $ */ /* $KAME: esp_input.c,v 1.22 2000/03/21 05:14:49 itojun Exp $ */ /* * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. * 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. * 3. Neither the name of the project nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE PROJECT 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 PROJECT 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. */ /* * RFC1827/2406 Encapsulated Security Payload. */ #include "opt_inet.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET6 #include #include #include #endif #include #include #include #include #include #include #include #include #define IPLEN_FLIPPED #ifdef INET extern struct protosw inetsw[]; extern u_char ip_protox[]; #define ESPMAXLEN \ (sizeof(struct esp) < sizeof(struct newesp) \ ? sizeof(struct newesp) : sizeof(struct esp)) void #if __STDC__ esp4_input(struct mbuf *m, ...) #else esp4_input(m, va_alist) struct mbuf *m; va_dcl #endif { struct ip *ip; struct esp *esp; struct esptail esptail; u_int32_t spi; struct secasvar *sav = NULL; size_t taillen; u_int16_t nxt; struct esp_algorithm *algo; int ivlen; size_t hlen; size_t esplen; int s; va_list ap; int off, proto; va_start(ap, m); off = va_arg(ap, int); proto = va_arg(ap, int); va_end(ap); /* sanity check for alignment. */ if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) { ipseclog((LOG_ERR, "IPv4 ESP input: packet alignment problem " "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len)); ipsecstat.in_inval++; goto bad; } if (m->m_len < off + ESPMAXLEN) { m = m_pullup(m, off + ESPMAXLEN); if (!m) { ipseclog((LOG_DEBUG, "IPv4 ESP input: can't pullup in esp4_input\n")); ipsecstat.in_inval++; goto bad; } } ip = mtod(m, struct ip *); esp = (struct esp *)(((u_int8_t *)ip) + off); #ifdef _IP_VHL hlen = IP_VHL_HL(ip->ip_vhl) << 2; #else hlen = ip->ip_hl << 2; #endif /* find the sassoc. */ spi = esp->esp_spi; if ((sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst, IPPROTO_ESP, spi)) == 0) { ipseclog((LOG_WARNING, "IPv4 ESP input: no key association found for spi %u\n", (u_int32_t)ntohl(spi))); ipsecstat.in_nosa++; goto bad; } KEYDEBUG(KEYDEBUG_IPSEC_STAMP, printf("DP esp4_input called to allocate SA:%p\n", sav)); if (sav->state != SADB_SASTATE_MATURE && sav->state != SADB_SASTATE_DYING) { ipseclog((LOG_DEBUG, "IPv4 ESP input: non-mature/dying SA found for spi %u\n", (u_int32_t)ntohl(spi))); ipsecstat.in_badspi++; goto bad; } if (sav->alg_enc == SADB_EALG_NONE) { ipseclog((LOG_DEBUG, "IPv4 ESP input: " "unspecified encryption algorithm for spi %u\n", (u_int32_t)ntohl(spi))); ipsecstat.in_badspi++; goto bad; } algo = &esp_algorithms[sav->alg_enc]; /*XXX*/ /* check if we have proper ivlen information */ ivlen = sav->ivlen; if (ivlen < 0) { ipseclog((LOG_ERR, "inproper ivlen in IPv4 ESP input: %s %s\n", ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav))); ipsecstat.in_inval++; goto bad; } if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay && (sav->alg_auth && sav->key_auth))) goto noreplaycheck; if (sav->alg_auth == SADB_AALG_NULL) goto noreplaycheck; /* * check for sequence number. */ if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) ; /*okey*/ else { ipsecstat.in_espreplay++; ipseclog((LOG_WARNING, "replay packet in IPv4 ESP input: %s %s\n", ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav))); goto bad; } /* check ICV */ { u_char sum0[AH_MAXSUMSIZE]; u_char sum[AH_MAXSUMSIZE]; struct ah_algorithm *sumalgo; size_t siz; sumalgo = &ah_algorithms[sav->alg_auth]; siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1)); if (AH_MAXSUMSIZE < siz) { ipseclog((LOG_DEBUG, "internal error: AH_MAXSUMSIZE must be larger than %lu\n", (u_long)siz)); ipsecstat.in_inval++; goto bad; } m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]); if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) { ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n", ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav))); ipsecstat.in_espauthfail++; goto bad; } if (bcmp(sum0, sum, siz) != 0) { ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n", ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav))); ipsecstat.in_espauthfail++; goto bad; } /* strip off the authentication data */ m_adj(m, -siz); ip = mtod(m, struct ip *); #ifdef IPLEN_FLIPPED ip->ip_len = ip->ip_len - siz; #else ip->ip_len = htons(ntohs(ip->ip_len) - siz); #endif m->m_flags |= M_AUTHIPDGM; ipsecstat.in_espauthsucc++; } /* * update sequence number. */ if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) { if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) { ipsecstat.in_espreplay++; goto bad; } } noreplaycheck: /* process main esp header. */ if (sav->flags & SADB_X_EXT_OLD) { /* RFC 1827 */ esplen = sizeof(struct esp); } else { /* RFC 2406 */ if (sav->flags & SADB_X_EXT_DERIV) esplen = sizeof(struct esp); else esplen = sizeof(struct newesp); } if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) { ipseclog((LOG_WARNING, "IPv4 ESP input: packet too short\n")); ipsecstat.in_inval++; goto bad; } if (m->m_len < off + esplen + ivlen) { m = m_pullup(m, off + esplen + ivlen); if (!m) { ipseclog((LOG_DEBUG, "IPv4 ESP input: can't pullup in esp4_input\n")); ipsecstat.in_inval++; goto bad; } } { /* * decrypt the packet. */ if (!algo->decrypt) panic("internal error: no decrypt function"); if ((*algo->decrypt)(m, off, sav, algo, ivlen)) { ipseclog((LOG_ERR, "decrypt fail in IPv4 ESP input: %s %s\n", ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav))); ipsecstat.in_inval++; goto bad; } ipsecstat.in_esphist[sav->alg_enc]++; m->m_flags |= M_DECRYPTED; } /* * find the trailer of the ESP. */ m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail), (caddr_t)&esptail); nxt = esptail.esp_nxt; taillen = esptail.esp_padlen + sizeof(esptail); if (m->m_pkthdr.len < taillen || m->m_pkthdr.len - taillen < hlen) { /*?*/ ipseclog((LOG_WARNING, "bad pad length in IPv4 ESP input: %s %s\n", ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav))); ipsecstat.in_inval++; goto bad; } /* strip off the trailing pad area. */ m_adj(m, -taillen); #ifdef IPLEN_FLIPPED ip->ip_len = ip->ip_len - taillen; #else ip->ip_len = htons(ntohs(ip->ip_len) - taillen); #endif /* was it transmitted over the IPsec tunnel SA? */ if (ipsec4_tunnel_validate(ip, nxt, sav)) { /* * strip off all the headers that precedes ESP header. * IP4 xx ESP IP4' payload -> IP4' payload * * XXX more sanity checks * XXX relationship with gif? */ u_int8_t tos; tos = ip->ip_tos; m_adj(m, off + esplen + ivlen); if (m->m_len < sizeof(*ip)) { m = m_pullup(m, sizeof(*ip)); if (!m) { ipsecstat.in_inval++; goto bad; } } ip = mtod(m, struct ip *); /* ECN consideration. */ ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos); if (!key_checktunnelsanity(sav, AF_INET, (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) { ipseclog((LOG_ERR, "ipsec tunnel address mismatch " "in IPv4 ESP input: %s %s\n", ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav))); ipsecstat.in_inval++; goto bad; } #if 0 /* XXX should call ipfw rather than ipsec_in_reject, shouldn't it ? */ /* drop it if it does not match the default policy */ if (ipsec4_in_reject(m, NULL)) { ipsecstat.in_polvio++; goto bad; } #endif key_sa_recordxfer(sav, m); s = splimp(); if (IF_QFULL(&ipintrq)) { ipsecstat.in_inval++; goto bad; } IF_ENQUEUE(&ipintrq, m); m = NULL; schednetisr(NETISR_IP); /*can be skipped but to make sure*/ splx(s); nxt = IPPROTO_DONE; } else { /* * strip off ESP header and IV. * even in m_pulldown case, we need to strip off ESP so that * we can always compute checksum for AH correctly. */ size_t stripsiz; stripsiz = esplen + ivlen; ip = mtod(m, struct ip *); ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off); m->m_data += stripsiz; m->m_len -= stripsiz; m->m_pkthdr.len -= stripsiz; ip = mtod(m, struct ip *); #ifdef IPLEN_FLIPPED ip->ip_len = ip->ip_len - stripsiz; #else ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz); #endif ip->ip_p = nxt; key_sa_recordxfer(sav, m); if (nxt != IPPROTO_DONE) (*inetsw[ip_protox[nxt]].pr_input)(m, off, nxt); else m_freem(m); m = NULL; } if (sav) { KEYDEBUG(KEYDEBUG_IPSEC_STAMP, printf("DP esp4_input call free SA:%p\n", sav)); key_freesav(sav); } ipsecstat.in_success++; return; bad: if (sav) { KEYDEBUG(KEYDEBUG_IPSEC_STAMP, printf("DP esp4_input call free SA:%p\n", sav)); key_freesav(sav); } if (m) m_freem(m); return; } #endif /* INET */ #ifdef INET6 int esp6_input(mp, offp, proto) struct mbuf **mp; int *offp, proto; { struct mbuf *m = *mp; int off = *offp; struct ip6_hdr *ip6; struct esp *esp; struct esptail esptail; u_int32_t spi; struct secasvar *sav = NULL; size_t taillen; u_int16_t nxt; struct esp_algorithm *algo; int ivlen; size_t esplen; int s; /* sanity check for alignment. */ if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) { ipseclog((LOG_ERR, "IPv6 ESP input: packet alignment problem " "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len)); ipsec6stat.in_inval++; goto bad; } #ifndef PULLDOWN_TEST IP6_EXTHDR_CHECK(m, off, ESPMAXLEN, IPPROTO_DONE); esp = (struct esp *)(mtod(m, caddr_t) + off); #else IP6_EXTHDR_GET(esp, struct esp *, m, off, ESPMAXLEN); if (esp == NULL) { ipsec6stat.in_inval++; return IPPROTO_DONE; } #endif ip6 = mtod(m, struct ip6_hdr *); if (ntohs(ip6->ip6_plen) == 0) { ipseclog((LOG_ERR, "IPv6 ESP input: " "ESP with IPv6 jumbogram is not supported.\n")); ipsec6stat.in_inval++; goto bad; } /* find the sassoc. */ spi = esp->esp_spi; if ((sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst, IPPROTO_ESP, spi)) == 0) { ipseclog((LOG_WARNING, "IPv6 ESP input: no key association found for spi %u\n", (u_int32_t)ntohl(spi))); ipsec6stat.in_nosa++; goto bad; } KEYDEBUG(KEYDEBUG_IPSEC_STAMP, printf("DP esp6_input called to allocate SA:%p\n", sav)); if (sav->state != SADB_SASTATE_MATURE && sav->state != SADB_SASTATE_DYING) { ipseclog((LOG_DEBUG, "IPv6 ESP input: non-mature/dying SA found for spi %u\n", (u_int32_t)ntohl(spi))); ipsec6stat.in_badspi++; goto bad; } if (sav->alg_enc == SADB_EALG_NONE) { ipseclog((LOG_DEBUG, "IPv6 ESP input: " "unspecified encryption algorithm for spi %u\n", (u_int32_t)ntohl(spi))); ipsec6stat.in_badspi++; goto bad; } algo = &esp_algorithms[sav->alg_enc]; /*XXX*/ /* check if we have proper ivlen information */ ivlen = sav->ivlen; if (ivlen < 0) { ipseclog((LOG_ERR, "inproper ivlen in IPv6 ESP input: %s %s\n", ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav))); ipsec6stat.in_badspi++; goto bad; } if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay && (sav->alg_auth && sav->key_auth))) goto noreplaycheck; if (sav->alg_auth == SADB_AALG_NULL) goto noreplaycheck; /* * check for sequence number. */ if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) ; /*okey*/ else { ipsec6stat.in_espreplay++; ipseclog((LOG_WARNING, "replay packet in IPv6 ESP input: %s %s\n", ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav))); goto bad; } /* check ICV */ { u_char sum0[AH_MAXSUMSIZE]; u_char sum[AH_MAXSUMSIZE]; struct ah_algorithm *sumalgo; size_t siz; sumalgo = &ah_algorithms[sav->alg_auth]; siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1)); if (AH_MAXSUMSIZE < siz) { ipseclog((LOG_DEBUG, "internal error: AH_MAXSUMSIZE must be larger than %lu\n", (u_long)siz)); ipsec6stat.in_inval++; goto bad; } m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]); if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) { ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n", ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav))); ipsec6stat.in_espauthfail++; goto bad; } if (bcmp(sum0, sum, siz) != 0) { ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n", ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav))); ipsec6stat.in_espauthfail++; goto bad; } /* strip off the authentication data */ m_adj(m, -siz); ip6 = mtod(m, struct ip6_hdr *); ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - siz); m->m_flags |= M_AUTHIPDGM; ipsec6stat.in_espauthsucc++; } /* * update sequence number. */ if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) { if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) { ipsec6stat.in_espreplay++; goto bad; } } noreplaycheck: /* process main esp header. */ if (sav->flags & SADB_X_EXT_OLD) { /* RFC 1827 */ esplen = sizeof(struct esp); } else { /* RFC 2406 */ if (sav->flags & SADB_X_EXT_DERIV) esplen = sizeof(struct esp); else esplen = sizeof(struct newesp); } if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) { ipseclog((LOG_WARNING, "IPv6 ESP input: packet too short\n")); ipsec6stat.in_inval++; goto bad; } #ifndef PULLDOWN_TEST IP6_EXTHDR_CHECK(m, off, esplen + ivlen, IPPROTO_DONE); /*XXX*/ #else IP6_EXTHDR_GET(esp, struct esp *, m, off, esplen + ivlen); if (esp == NULL) { ipsec6stat.in_inval++; m = NULL; goto bad; } #endif ip6 = mtod(m, struct ip6_hdr *); /*set it again just in case*/ /* * decrypt the packet. */ if (!algo->decrypt) panic("internal error: no decrypt function"); if ((*algo->decrypt)(m, off, sav, algo, ivlen)) { ipseclog((LOG_ERR, "decrypt fail in IPv6 ESP input: %s %s\n", ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav))); ipsec6stat.in_inval++; goto bad; } ipsec6stat.in_esphist[sav->alg_enc]++; m->m_flags |= M_DECRYPTED; /* * find the trailer of the ESP. */ m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail), (caddr_t)&esptail); nxt = esptail.esp_nxt; taillen = esptail.esp_padlen + sizeof(esptail); if (m->m_pkthdr.len < taillen || m->m_pkthdr.len - taillen < sizeof(struct ip6_hdr)) { /*?*/ ipseclog((LOG_WARNING, "bad pad length in IPv6 ESP input: %s %s\n", ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav))); ipsec6stat.in_inval++; goto bad; } /* strip off the trailing pad area. */ m_adj(m, -taillen); ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - taillen); /* was it transmitted over the IPsec tunnel SA? */ if (ipsec6_tunnel_validate(ip6, nxt, sav)) { /* * strip off all the headers that precedes ESP header. * IP6 xx ESP IP6' payload -> IP6' payload * * XXX more sanity checks * XXX relationship with gif? */ u_int32_t flowinfo; /*net endian*/ flowinfo = ip6->ip6_flow; m_adj(m, off + esplen + ivlen); if (m->m_len < sizeof(*ip6)) { #ifndef PULLDOWN_TEST /* * m_pullup is prohibited in KAME IPv6 input processing * but there's no other way! */ #else /* okay to pullup in m_pulldown style */ #endif m = m_pullup(m, sizeof(*ip6)); if (!m) { ipsec6stat.in_inval++; goto bad; } } ip6 = mtod(m, struct ip6_hdr *); /* ECN consideration. */ ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow); if (!key_checktunnelsanity(sav, AF_INET6, (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) { ipseclog((LOG_ERR, "ipsec tunnel address mismatch " "in IPv6 ESP input: %s %s\n", ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav))); ipsec6stat.in_inval++; goto bad; } #if 0 /* XXX should call ipfw rather than ipsec_in_reject, shouldn't it ? */ /* drop it if it does not match the default policy */ if (ipsec6_in_reject(m, NULL)) { ipsec6stat.in_polvio++; goto bad; } #endif key_sa_recordxfer(sav, m); s = splimp(); if (IF_QFULL(&ip6intrq)) { ipsec6stat.in_inval++; goto bad; } IF_ENQUEUE(&ip6intrq, m); m = NULL; schednetisr(NETISR_IPV6); /*can be skipped but to make sure*/ splx(s); nxt = IPPROTO_DONE; } else { /* * strip off ESP header and IV. * even in m_pulldown case, we need to strip off ESP so that * we can always compute checksum for AH correctly. */ size_t stripsiz; char *prvnxtp; /* * Set the next header field of the previous header correctly. */ prvnxtp = ip6_get_prevhdr(m, off); /* XXX */ *prvnxtp = nxt; stripsiz = esplen + ivlen; ip6 = mtod(m, struct ip6_hdr *); if (m->m_len >= stripsiz + off) { ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off); m->m_data += stripsiz; m->m_len -= stripsiz; m->m_pkthdr.len -= stripsiz; } else { /* * this comes with no copy if the boundary is on * cluster */ struct mbuf *n; n = m_split(m, off, M_DONTWAIT); if (n == NULL) { /* m is retained by m_split */ goto bad; } m_adj(n, stripsiz); m_cat(m, n); /* m_cat does not update m_pkthdr.len */ m->m_pkthdr.len += n->m_pkthdr.len; } ip6 = mtod(m, struct ip6_hdr *); ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz); key_sa_recordxfer(sav, m); } *offp = off; *mp = m; if (sav) { KEYDEBUG(KEYDEBUG_IPSEC_STAMP, printf("DP esp6_input call free SA:%p\n", sav)); key_freesav(sav); } ipsec6stat.in_success++; return nxt; bad: if (sav) { KEYDEBUG(KEYDEBUG_IPSEC_STAMP, printf("DP esp6_input call free SA:%p\n", sav)); key_freesav(sav); } if (m) m_freem(m); return IPPROTO_DONE; } #endif /* INET6 */