/* $OpenBSD: ip_ah.c,v 1.74 2003/04/02 20:09:26 millert 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). * * The original version of 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 and Niklas Hallqvist. * * Copyright (c) 1995, 1996, 1997, 1998, 1999 by John Ioannidis, * Angelos D. Keromytis and Niels Provos. * Copyright (c) 1999 Niklas Hallqvist. * 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 <sys/param.h> #include <sys/systm.h> #include <sys/mbuf.h> #include <sys/socket.h> #include <net/if.h> #include <net/bpf.h> #ifdef INET #include <netinet/in.h> #include <netinet/in_systm.h> #include <netinet/ip.h> #endif /* INET */ #ifdef INET6 #ifndef INET #include <netinet/in.h> #endif /* INET */ #include <netinet/ip6.h> #endif /* INET6 */ #include <netinet/ip_ipsp.h> #include <netinet/ip_ah.h> #include <net/pfkeyv2.h> #include <net/if_enc.h> #include <crypto/cryptodev.h> #include <crypto/xform.h> #include "bpfilter.h" #ifdef ENCDEBUG #define DPRINTF(x) if (encdebug) printf x #else #define DPRINTF(x) #endif struct ahstat ahstat; /* * ah_attach() is called from the transformation initialization code. */ int ah_attach() { return 0; } /* * ah_init() is called when an SPI is being set up. */ int ah_init(struct tdb *tdbp, struct xformsw *xsp, struct ipsecinit *ii) { struct auth_hash *thash = NULL; struct cryptoini cria; /* Authentication operation. */ switch (ii->ii_authalg) { case SADB_AALG_MD5HMAC: thash = &auth_hash_hmac_md5_96; break; case SADB_AALG_SHA1HMAC: thash = &auth_hash_hmac_sha1_96; break; case SADB_AALG_RIPEMD160HMAC: thash = &auth_hash_hmac_ripemd_160_96; break; case SADB_X_AALG_MD5: thash = &auth_hash_key_md5; break; case SADB_X_AALG_SHA1: thash = &auth_hash_key_sha1; break; default: DPRINTF(("ah_init(): unsupported authentication algorithm %d specified\n", ii->ii_authalg)); return EINVAL; } if (ii->ii_authkeylen != thash->keysize && thash->keysize != 0) { DPRINTF(("ah_init(): keylength %d doesn't match algorithm " "%s keysize (%d)\n", ii->ii_authkeylen, thash->name, thash->keysize)); return EINVAL; } tdbp->tdb_xform = xsp; tdbp->tdb_authalgxform = thash; tdbp->tdb_bitmap = 0; tdbp->tdb_rpl = AH_HMAC_INITIAL_RPL; DPRINTF(("ah_init(): initialized TDB with hash algorithm %s\n", thash->name)); tdbp->tdb_amxkeylen = ii->ii_authkeylen; MALLOC(tdbp->tdb_amxkey, u_int8_t *, tdbp->tdb_amxkeylen, M_XDATA, M_WAITOK); bcopy(ii->ii_authkey, tdbp->tdb_amxkey, tdbp->tdb_amxkeylen); /* Initialize crypto session. */ bzero(&cria, sizeof(cria)); cria.cri_alg = tdbp->tdb_authalgxform->type; cria.cri_klen = ii->ii_authkeylen * 8; cria.cri_key = ii->ii_authkey; return crypto_newsession(&tdbp->tdb_cryptoid, &cria, 0); } /* * Paranoia. */ int ah_zeroize(struct tdb *tdbp) { int err; if (tdbp->tdb_amxkey) { bzero(tdbp->tdb_amxkey, tdbp->tdb_amxkeylen); FREE(tdbp->tdb_amxkey, M_XDATA); tdbp->tdb_amxkey = NULL; } err = crypto_freesession(tdbp->tdb_cryptoid); tdbp->tdb_cryptoid = 0; return err; } /* * Massage IPv4/IPv6 headers for AH processing. */ int ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out) { struct mbuf *m = *m0; unsigned char *ptr; int off, count; #ifdef INET struct ip *ip; #endif /* INET */ #ifdef INET6 struct ip6_ext *ip6e; struct ip6_hdr ip6; int alloc, len, ad; #endif /* INET6 */ switch (proto) { #ifdef INET case AF_INET: /* * This is the least painful way of dealing with IPv4 header * and option processing -- just make sure they're in * contiguous memory. */ *m0 = m = m_pullup(m, skip); if (m == NULL) { DPRINTF(("ah_massage_headers(): m_pullup() failed\n")); ahstat.ahs_hdrops++; return ENOBUFS; } /* Fix the IP header */ ip = mtod(m, struct ip *); ip->ip_tos = 0; ip->ip_ttl = 0; ip->ip_sum = 0; /* * On input, fix ip_len which has been byte-swapped * at ip_input(). */ if (!out) { ip->ip_len += skip; HTONS(ip->ip_len); if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK) ip->ip_off = htons(ip->ip_off & IP_DF); else ip->ip_off = 0; } else { if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK) ip->ip_off = htons(ntohs(ip->ip_off) & IP_DF); else ip->ip_off = 0; } ptr = mtod(m, unsigned char *) + sizeof(struct ip); /* IPv4 option processing */ for (off = sizeof(struct ip); off < skip;) { if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP || off + 1 < skip) ; else { DPRINTF(("ah_massage_headers(): illegal IPv4 " "option length for option %d\n", ptr[off])); ahstat.ahs_hdrops++; m_freem(m); return EINVAL; } switch (ptr[off]) { case IPOPT_EOL: off = skip; /* End the loop. */ break; case IPOPT_NOP: off++; break; case IPOPT_SECURITY: /* 0x82 */ case 0x85: /* Extended security. */ case 0x86: /* Commercial security. */ case 0x94: /* Router alert */ case 0x95: /* RFC1770 */ /* Sanity check for option length. */ if (ptr[off + 1] < 2) { DPRINTF(("ah_massage_headers(): " "illegal IPv4 option length for " "option %d\n", ptr[off])); ahstat.ahs_hdrops++; m_freem(m); return EINVAL; } off += ptr[off + 1]; break; case IPOPT_LSRR: case IPOPT_SSRR: /* Sanity check for option length. */ if (ptr[off + 1] < 2) { DPRINTF(("ah_massage_headers(): " "illegal IPv4 option length for " "option %d\n", ptr[off])); ahstat.ahs_hdrops++; m_freem(m); return EINVAL; } /* * On output, if we have either of the * source routing options, we should * swap the destination address of the * IP header with the last address * specified in the option, as that is * what the destination's IP header * will look like. */ if (out) bcopy(ptr + off + ptr[off + 1] - sizeof(struct in_addr), &(ip->ip_dst), sizeof(struct in_addr)); /* Fall through */ default: /* Sanity check for option length. */ if (ptr[off + 1] < 2) { DPRINTF(("ah_massage_headers(): " "illegal IPv4 option length for " "option %d\n", ptr[off])); ahstat.ahs_hdrops++; m_freem(m); return EINVAL; } /* Zeroize all other options. */ count = ptr[off + 1]; bcopy(ipseczeroes, ptr, count); off += count; break; } /* Sanity check. */ if (off > skip) { DPRINTF(("ah_massage_headers(): malformed " "IPv4 options header\n")); ahstat.ahs_hdrops++; m_freem(m); return EINVAL; } } break; #endif /* INET */ #ifdef INET6 case AF_INET6: /* Ugly... */ /* Copy and "cook" the IPv6 header. */ m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6); /* We don't do IPv6 Jumbograms. */ if (ip6.ip6_plen == 0) { DPRINTF(("ah_massage_headers(): unsupported IPv6 " "jumbogram")); ahstat.ahs_hdrops++; m_freem(m); return EMSGSIZE; } ip6.ip6_flow = 0; ip6.ip6_hlim = 0; ip6.ip6_vfc &= ~IPV6_VERSION_MASK; ip6.ip6_vfc |= IPV6_VERSION; /* Scoped address handling. */ if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src)) ip6.ip6_src.s6_addr16[1] = 0; if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst)) ip6.ip6_dst.s6_addr16[1] = 0; /* Done with IPv6 header. */ m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6); /* Let's deal with the remaining headers (if any). */ if (skip - sizeof(struct ip6_hdr) > 0) { if (m->m_len <= skip) { MALLOC(ptr, unsigned char *, skip - sizeof(struct ip6_hdr), M_XDATA, M_NOWAIT); if (ptr == NULL) { DPRINTF(("ah_massage_headers(): failed to allocate memory for IPv6 headers\n")); ahstat.ahs_hdrops++; m_freem(m); return ENOBUFS; } /* * Copy all the protocol headers after * the IPv6 header. */ m_copydata(m, sizeof(struct ip6_hdr), skip - sizeof(struct ip6_hdr), ptr); alloc = 1; } else { /* No need to allocate memory. */ ptr = mtod(m, unsigned char *) + sizeof(struct ip6_hdr); alloc = 0; } } else break; off = ip6.ip6_nxt & 0xff; /* Next header type. */ for (len = 0; len < skip - sizeof(struct ip6_hdr);) switch (off) { case IPPROTO_HOPOPTS: case IPPROTO_DSTOPTS: ip6e = (struct ip6_ext *) (ptr + len); /* * Process the mutable/immutable * options -- borrows heavily from the * KAME code. */ for (count = len + sizeof(struct ip6_ext); count < len + ((ip6e->ip6e_len + 1) << 3);) { if (ptr[count] == IP6OPT_PAD1) { count++; continue; /* Skip padding. */ } /* Sanity check. */ if (count > len + ((ip6e->ip6e_len + 1) << 3)) { ahstat.ahs_hdrops++; m_freem(m); /* Free, if we allocated. */ if (alloc) FREE(ptr, M_XDATA); return EINVAL; } ad = ptr[count + 1]; /* If mutable option, zeroize. */ if (ptr[count] & IP6OPT_MUTABLE) bcopy(ipseczeroes, ptr + count, ptr[count + 1]); count += ad; /* Sanity check. */ if (count > skip - sizeof(struct ip6_hdr)) { ahstat.ahs_hdrops++; m_freem(m); /* Free, if we allocated. */ if (alloc) FREE(ptr, M_XDATA); return EINVAL; } } /* Advance. */ len += ((ip6e->ip6e_len + 1) << 3); off = ip6e->ip6e_nxt; break; case IPPROTO_ROUTING: /* * Always include routing headers in * computation. */ ip6e = (struct ip6_ext *) (ptr + len); len += ((ip6e->ip6e_len + 1) << 3); off = ip6e->ip6e_nxt; break; default: DPRINTF(("ah_massage_headers(): unexpected " "IPv6 header type %d\n", off)); if (alloc) FREE(ptr, M_XDATA); ahstat.ahs_hdrops++; m_freem(m); return EINVAL; } /* Copyback and free, if we allocated. */ if (alloc) { m_copyback(m, sizeof(struct ip6_hdr), skip - sizeof(struct ip6_hdr), ptr); FREE(ptr, M_XDATA); } break; #endif /* INET6 */ } return 0; } /* * ah_input() gets called to verify that an input packet * passes authentication. */ int ah_input(struct mbuf *m, struct tdb *tdb, int skip, int protoff) { struct auth_hash *ahx = (struct auth_hash *) tdb->tdb_authalgxform; struct tdb_ident *tdbi; struct tdb_crypto *tc; struct m_tag *mtag; u_int32_t btsx; u_int8_t hl; int rplen; struct cryptodesc *crda = NULL; struct cryptop *crp; if (!(tdb->tdb_flags & TDBF_NOREPLAY)) rplen = AH_FLENGTH + sizeof(u_int32_t); else rplen = AH_FLENGTH; /* Save the AH header, we use it throughout. */ m_copydata(m, skip + offsetof(struct ah, ah_hl), sizeof(u_int8_t), (caddr_t) &hl); /* Replay window checking, if applicable. */ if ((tdb->tdb_wnd > 0) && (!(tdb->tdb_flags & TDBF_NOREPLAY))) { m_copydata(m, skip + offsetof(struct ah, ah_rpl), sizeof(u_int32_t), (caddr_t) &btsx); btsx = ntohl(btsx); switch (checkreplaywindow32(btsx, 0, &(tdb->tdb_rpl), tdb->tdb_wnd, &(tdb->tdb_bitmap), 0)) { case 0: /* All's well. */ break; case 1: DPRINTF(("ah_input(): replay counter wrapped for " "SA %s/%08x\n", ipsp_address(tdb->tdb_dst), ntohl(tdb->tdb_spi))); ahstat.ahs_wrap++; m_freem(m); return ENOBUFS; case 2: case 3: DPRINTF(("ah_input(): duplicate packet received in " "SA %s/%08x\n", ipsp_address(tdb->tdb_dst), ntohl(tdb->tdb_spi))); m_freem(m); return ENOBUFS; default: DPRINTF(("ah_input(): bogus value from " "checkreplaywindow32() in SA %s/%08x\n", ipsp_address(tdb->tdb_dst), ntohl(tdb->tdb_spi))); ahstat.ahs_replay++; m_freem(m); return ENOBUFS; } } /* Verify AH header length. */ if (hl * sizeof(u_int32_t) != ahx->authsize + rplen - AH_FLENGTH) { DPRINTF(("ah_input(): bad authenticator length %d for packet " "in SA %s/%08x\n", hl * sizeof(u_int32_t), ipsp_address(tdb->tdb_dst), ntohl(tdb->tdb_spi))); ahstat.ahs_badauthl++; m_freem(m); return EACCES; } /* Update the counters. */ tdb->tdb_cur_bytes += (m->m_pkthdr.len - skip - hl * sizeof(u_int32_t)); ahstat.ahs_ibytes += (m->m_pkthdr.len - skip - hl * sizeof(u_int32_t)); /* Hard expiration. */ if (tdb->tdb_flags & TDBF_BYTES && tdb->tdb_cur_bytes >= tdb->tdb_exp_bytes) { pfkeyv2_expire(tdb, SADB_EXT_LIFETIME_HARD); tdb_delete(tdb); m_freem(m); return ENXIO; } /* Notify on expiration. */ if (tdb->tdb_flags & TDBF_SOFT_BYTES && tdb->tdb_cur_bytes >= tdb->tdb_soft_bytes) { pfkeyv2_expire(tdb, SADB_EXT_LIFETIME_SOFT); tdb->tdb_flags &= ~TDBF_SOFT_BYTES; /* Turn off checking. */ } /* Get crypto descriptors. */ crp = crypto_getreq(1); if (crp == NULL) { m_freem(m); DPRINTF(("ah_input(): failed to acquire crypto " "descriptors\n")); ahstat.ahs_crypto++; return ENOBUFS; } crda = crp->crp_desc; crda->crd_skip = 0; crda->crd_len = m->m_pkthdr.len; crda->crd_inject = skip + rplen; /* Authentication operation. */ crda->crd_alg = ahx->type; crda->crd_key = tdb->tdb_amxkey; crda->crd_klen = tdb->tdb_amxkeylen * 8; /* Find out if we've already done crypto. */ for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL); mtag != NULL; mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) { tdbi = (struct tdb_ident *) (mtag + 1); if (tdbi->proto == tdb->tdb_sproto && tdbi->spi == tdb->tdb_spi && !bcmp(&tdbi->dst, &tdb->tdb_dst, sizeof(union sockaddr_union))) break; } /* Allocate IPsec-specific opaque crypto info. */ if (mtag == NULL) MALLOC(tc, struct tdb_crypto *, sizeof(struct tdb_crypto) + skip + rplen + ahx->authsize, M_XDATA, M_NOWAIT); else /* Hash verification has already been done successfully. */ MALLOC(tc, struct tdb_crypto *, sizeof(struct tdb_crypto), M_XDATA, M_NOWAIT); if (tc == NULL) { m_freem(m); crypto_freereq(crp); DPRINTF(("ah_input(): failed to allocate tdb_crypto\n")); ahstat.ahs_crypto++; return ENOBUFS; } bzero(tc, sizeof(struct tdb_crypto)); /* Only save information if crypto processing is needed. */ if (mtag == NULL) { /* * Save the authenticator, the skipped portion of the packet, * and the AH header. */ m_copydata(m, 0, skip + rplen + ahx->authsize, (caddr_t) (tc + 1)); /* Zeroize the authenticator on the packet. */ m_copyback(m, skip + rplen, ahx->authsize, ipseczeroes); /* "Massage" the packet headers for crypto processing. */ if ((btsx = ah_massage_headers(&m, tdb->tdb_dst.sa.sa_family, skip, ahx->type, 0)) != 0) { /* mbuf will be free'd by callee. */ FREE(tc, M_XDATA); crypto_freereq(crp); return btsx; } } /* Crypto operation descriptor. */ crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ crp->crp_flags = CRYPTO_F_IMBUF; crp->crp_buf = (caddr_t) m; crp->crp_callback = (int (*) (struct cryptop *)) ah_input_cb; crp->crp_sid = tdb->tdb_cryptoid; crp->crp_opaque = (caddr_t) tc; /* These are passed as-is to the callback. */ tc->tc_skip = skip; tc->tc_protoff = protoff; tc->tc_spi = tdb->tdb_spi; tc->tc_proto = tdb->tdb_sproto; tc->tc_ptr = (caddr_t) mtag; /* Save the mtag we've identified. */ bcopy(&tdb->tdb_dst, &tc->tc_dst, sizeof(union sockaddr_union)); if (mtag == NULL) return crypto_dispatch(crp); else return ah_input_cb(crp); } /* * AH input callback, called directly by the crypto driver. */ int ah_input_cb(void *op) { int s, roff, rplen, error, skip, protoff; unsigned char calc[AH_ALEN_MAX]; struct mbuf *m1, *m0, *m; struct cryptodesc *crd; struct auth_hash *ahx; struct tdb_crypto *tc; struct cryptop *crp; struct m_tag *mtag; struct tdb *tdb; u_int32_t btsx; u_int8_t prot; caddr_t ptr; crp = (struct cryptop *) op; crd = crp->crp_desc; tc = (struct tdb_crypto *) crp->crp_opaque; skip = tc->tc_skip; protoff = tc->tc_protoff; mtag = (struct m_tag *) tc->tc_ptr; m = (struct mbuf *) crp->crp_buf; if (m == NULL) { /* Shouldn't happen... */ FREE(tc, M_XDATA); crypto_freereq(crp); ahstat.ahs_crypto++; DPRINTF(("ah_input_cb(): bogus returned buffer from " "crypto\n")); return (EINVAL); } s = spltdb(); tdb = gettdb(tc->tc_spi, &tc->tc_dst, tc->tc_proto); if (tdb == NULL) { FREE(tc, M_XDATA); ahstat.ahs_notdb++; DPRINTF(("ah_input_cb(): TDB is expired while in crypto")); error = EPERM; goto baddone; } ahx = (struct auth_hash *) tdb->tdb_authalgxform; /* Check for crypto errors. */ if (crp->crp_etype) { if (crp->crp_etype == EAGAIN) { /* Reset the session ID */ if (tdb->tdb_cryptoid != 0) tdb->tdb_cryptoid = crp->crp_sid; splx(s); return crypto_dispatch(crp); } FREE(tc, M_XDATA); ahstat.ahs_noxform++; DPRINTF(("ah_input_cb(): crypto error %d\n", crp->crp_etype)); error = crp->crp_etype; goto baddone; } else { crypto_freereq(crp); /* No longer needed. */ crp = NULL; } if (!(tdb->tdb_flags & TDBF_NOREPLAY)) rplen = AH_FLENGTH + sizeof(u_int32_t); else rplen = AH_FLENGTH; /* Copy authenticator off the packet. */ m_copydata(m, skip + rplen, ahx->authsize, calc); /* * If we have an mtag, we don't need to verify the authenticator -- * it has been verified by an IPsec-aware NIC. */ if (mtag == NULL) { ptr = (caddr_t) (tc + 1); /* Verify authenticator. */ if (bcmp(ptr + skip + rplen, calc, ahx->authsize)) { FREE(tc, M_XDATA); DPRINTF(("ah_input(): authentication failed for " "packet in SA %s/%08x\n", ipsp_address(tdb->tdb_dst), ntohl(tdb->tdb_spi))); ahstat.ahs_badauth++; error = EACCES; goto baddone; } /* Fix the Next Protocol field. */ ((u_int8_t *) ptr)[protoff] = ((u_int8_t *) ptr)[skip]; /* Copyback the saved (uncooked) network headers. */ m_copyback(m, 0, skip, ptr); } else { /* Fix the Next Protocol field. */ m_copydata(m, skip, sizeof(u_int8_t), &prot); m_copyback(m, protoff, sizeof(u_int8_t), &prot); } FREE(tc, M_XDATA); /* Replay window checking, if applicable. */ if ((tdb->tdb_wnd > 0) && (!(tdb->tdb_flags & TDBF_NOREPLAY))) { m_copydata(m, skip + offsetof(struct ah, ah_rpl), sizeof(u_int32_t), (caddr_t) &btsx); btsx = ntohl(btsx); switch (checkreplaywindow32(btsx, 0, &(tdb->tdb_rpl), tdb->tdb_wnd, &(tdb->tdb_bitmap), 1)) { case 0: /* All's well. */ break; case 1: DPRINTF(("ah_input(): replay counter wrapped for " "SA %s/%08x\n", ipsp_address(tdb->tdb_dst), ntohl(tdb->tdb_spi))); ahstat.ahs_wrap++; error = ENOBUFS; goto baddone; case 2: case 3: DPRINTF(("ah_input_cb(): duplicate packet received in " "SA %s/%08x\n", ipsp_address(tdb->tdb_dst), ntohl(tdb->tdb_spi))); error = ENOBUFS; goto baddone; default: DPRINTF(("ah_input_cb(): bogus value from " "checkreplaywindow32() in SA %s/%08x\n", ipsp_address(tdb->tdb_dst), ntohl(tdb->tdb_spi))); ahstat.ahs_replay++; error = ENOBUFS; goto baddone; } } /* Record the beginning of the AH header. */ m1 = m_getptr(m, skip, &roff); if (m1 == NULL) { ahstat.ahs_hdrops++; splx(s); m_freem(m); DPRINTF(("ah_input(): bad mbuf chain for packet in SA " "%s/%08x\n", ipsp_address(tdb->tdb_dst), ntohl(tdb->tdb_spi))); return EINVAL; } /* Remove the AH header from the mbuf. */ if (roff == 0) { /* * The AH header was conveniently at the beginning of * the mbuf. */ m_adj(m1, rplen + ahx->authsize); if (!(m1->m_flags & M_PKTHDR)) m->m_pkthdr.len -= rplen + ahx->authsize; } else if (roff + rplen + ahx->authsize >= m1->m_len) { /* * Part or all of the AH header is at the end * of this mbuf, so first let's remove the * remainder of the AH header from the * beginning of the remainder of the mbuf * chain, if any. */ if (roff + rplen + ahx->authsize > m1->m_len) { /* Adjust the next mbuf by the remainder. */ m_adj(m1->m_next, roff + rplen + ahx->authsize - m1->m_len); /* * The second mbuf is guaranteed not * to have a pkthdr... */ m->m_pkthdr.len -= (roff + rplen + ahx->authsize - m1->m_len); } /* Now, let's unlink the mbuf chain for a second... */ m0 = m1->m_next; m1->m_next = NULL; /* * ...and trim the end of the first part of * the chain...sick */ m_adj(m1, -(m1->m_len - roff)); if (!(m1->m_flags & M_PKTHDR)) m->m_pkthdr.len -= (m1->m_len - roff); /* Finally, let's relink. */ m1->m_next = m0; } else { /* * The AH header lies in the "middle" of the * mbuf...do an overlapping copy of the * remainder of the mbuf over the ESP header. */ bcopy(mtod(m1, u_char *) + roff + rplen + ahx->authsize, mtod(m1, u_char *) + roff, m1->m_len - (roff + rplen + ahx->authsize)); m1->m_len -= rplen + ahx->authsize; m->m_pkthdr.len -= rplen + ahx->authsize; } error = ipsec_common_input_cb(m, tdb, skip, protoff, mtag); splx(s); return (error); baddone: splx(s); if (m != NULL) m_freem(m); if (crp != NULL) crypto_freereq(crp); return (error); } /* * AH output routine, called by ipsp_process_packet(). */ int ah_output(struct mbuf *m, struct tdb *tdb, struct mbuf **mp, int skip, int protoff) { struct auth_hash *ahx = (struct auth_hash *) tdb->tdb_authalgxform; struct cryptodesc *crda; struct tdb_crypto *tc; struct mbuf *mo, *mi; struct cryptop *crp; u_int16_t iplen; int len, rplen; u_int8_t prot; struct ah *ah; #if NBPFILTER > 0 { struct ifnet *ifn; struct enchdr hdr; struct mbuf m1; bzero (&hdr, sizeof(hdr)); hdr.af = tdb->tdb_dst.sa.sa_family; hdr.spi = tdb->tdb_spi; hdr.flags |= M_AUTH | M_AUTH_AH; m1.m_next = m; m1.m_len = ENC_HDRLEN; m1.m_data = (char *) &hdr; ifn = &(encif[0].sc_if); if (ifn->if_bpf) bpf_mtap(ifn->if_bpf, &m1); } #endif ahstat.ahs_output++; /* * Check for replay counter wrap-around in automatic (not * manual) keying. */ if ((tdb->tdb_rpl == 0) && (tdb->tdb_wnd > 0) && (!(tdb->tdb_flags & TDBF_NOREPLAY))) { DPRINTF(("ah_output(): SA %s/%08x should have expired\n", ipsp_address(tdb->tdb_dst), ntohl(tdb->tdb_spi))); m_freem(m); ahstat.ahs_wrap++; return EINVAL; } if (!(tdb->tdb_flags & TDBF_NOREPLAY)) rplen = AH_FLENGTH + sizeof(u_int32_t); else rplen = AH_FLENGTH; switch (tdb->tdb_dst.sa.sa_family) { #ifdef INET case AF_INET: /* Check for IP maximum packet size violations. */ if (rplen + ahx->authsize + m->m_pkthdr.len > IP_MAXPACKET) { DPRINTF(("ah_output(): packet in SA %s/%08x got too " "big\n", ipsp_address(tdb->tdb_dst), ntohl(tdb->tdb_spi))); m_freem(m); ahstat.ahs_toobig++; return EMSGSIZE; } break; #endif /* INET */ #ifdef INET6 case AF_INET6: /* Check for IPv6 maximum packet size violations. */ if (rplen + ahx->authsize + m->m_pkthdr.len > IPV6_MAXPACKET) { DPRINTF(("ah_output(): packet in SA %s/%08x " "got too big\n", ipsp_address(tdb->tdb_dst), ntohl(tdb->tdb_spi))); m_freem(m); ahstat.ahs_toobig++; return EMSGSIZE; } break; #endif /* INET6 */ default: DPRINTF(("ah_output(): unknown/unsupported protocol " "family %d, SA %s/%08x\n", tdb->tdb_dst.sa.sa_family, ipsp_address(tdb->tdb_dst), ntohl(tdb->tdb_spi))); m_freem(m); ahstat.ahs_nopf++; return EPFNOSUPPORT; } /* Update the counters. */ tdb->tdb_cur_bytes += m->m_pkthdr.len - skip; ahstat.ahs_obytes += m->m_pkthdr.len - skip; /* Hard expiration. */ if (tdb->tdb_flags & TDBF_BYTES && tdb->tdb_cur_bytes >= tdb->tdb_exp_bytes) { pfkeyv2_expire(tdb, SADB_EXT_LIFETIME_HARD); tdb_delete(tdb); m_freem(m); return EINVAL; } /* Notify on expiration. */ if (tdb->tdb_flags & TDBF_SOFT_BYTES && tdb->tdb_cur_bytes >= tdb->tdb_soft_bytes) { pfkeyv2_expire(tdb, SADB_EXT_LIFETIME_SOFT); tdb->tdb_flags &= ~TDBF_SOFT_BYTES; /* Turn off checking */ } /* * Loop through mbuf chain; if we find an M_EXT mbuf with * more than one reference, replace the rest of the chain. */ mo = NULL; mi = m; while (mi != NULL && (!(mi->m_flags & M_EXT) || !MCLISREFERENCED(mi))) { mo = mi; mi = mi->m_next; } if (mi != NULL) { /* Replace the rest of the mbuf chain. */ struct mbuf *n = m_copym2(mi, 0, M_COPYALL, M_DONTWAIT); if (n == NULL) { ahstat.ahs_hdrops++; m_freem(m); return ENOBUFS; } if (mo != NULL) mo->m_next = n; else m = n; m_freem(mi); } /* Inject AH header. */ mi = m_inject(m, skip, rplen + ahx->authsize, M_DONTWAIT); if (mi == NULL) { DPRINTF(("ah_output(): failed to inject AH header for SA " "%s/%08x\n", ipsp_address(tdb->tdb_dst), ntohl(tdb->tdb_spi))); m_freem(m); ahstat.ahs_hdrops++; return ENOBUFS; } /* * The AH header is guaranteed by m_inject() to be in * contiguous memory, at the beginning of the returned mbuf. */ ah = mtod(mi, struct ah *); /* Initialize the AH header. */ m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nh); ah->ah_hl = (rplen + ahx->authsize - AH_FLENGTH) / sizeof(u_int32_t); ah->ah_rv = 0; ah->ah_spi = tdb->tdb_spi; /* Zeroize authenticator. */ m_copyback(m, skip + rplen, ahx->authsize, ipseczeroes); if (!(tdb->tdb_flags & TDBF_NOREPLAY)) ah->ah_rpl = htonl(tdb->tdb_rpl++); /* Get crypto descriptors. */ crp = crypto_getreq(1); if (crp == NULL) { m_freem(m); DPRINTF(("ah_output(): failed to acquire crypto " "descriptors\n")); ahstat.ahs_crypto++; return ENOBUFS; } crda = crp->crp_desc; crda->crd_skip = 0; crda->crd_inject = skip + rplen; crda->crd_len = m->m_pkthdr.len; /* Authentication operation. */ crda->crd_alg = ahx->type; crda->crd_key = tdb->tdb_amxkey; crda->crd_klen = tdb->tdb_amxkeylen * 8; /* Allocate IPsec-specific opaque crypto info. */ if ((tdb->tdb_flags & TDBF_SKIPCRYPTO) == 0) MALLOC(tc, struct tdb_crypto *, sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT); else MALLOC(tc, struct tdb_crypto *, sizeof(struct tdb_crypto), M_XDATA, M_NOWAIT); if (tc == NULL) { m_freem(m); crypto_freereq(crp); DPRINTF(("ah_output(): failed to allocate tdb_crypto\n")); ahstat.ahs_crypto++; return ENOBUFS; } bzero(tc, sizeof(struct tdb_crypto)); /* Save the skipped portion of the packet. */ if ((tdb->tdb_flags & TDBF_SKIPCRYPTO) == 0) { m_copydata(m, 0, skip, (caddr_t) (tc + 1)); /* * Fix IP header length on the header used for * authentication. We don't need to fix the original * header length as it will be fixed by our caller. */ switch (tdb->tdb_dst.sa.sa_family) { #ifdef INET case AF_INET: bcopy(((caddr_t)(tc + 1)) + offsetof(struct ip, ip_len), (caddr_t) &iplen, sizeof(u_int16_t)); iplen = htons(ntohs(iplen) + rplen + ahx->authsize); m_copyback(m, offsetof(struct ip, ip_len), sizeof(u_int16_t), (caddr_t) &iplen); break; #endif /* INET */ #ifdef INET6 case AF_INET6: bcopy(((caddr_t)(tc + 1)) + offsetof(struct ip6_hdr, ip6_plen), (caddr_t) &iplen, sizeof(u_int16_t)); iplen = htons(ntohs(iplen) + rplen + ahx->authsize); m_copyback(m, offsetof(struct ip6_hdr, ip6_plen), sizeof(u_int16_t), (caddr_t) &iplen); break; #endif /* INET6 */ } /* Fix the Next Header field in saved header. */ ((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH; /* Update the Next Protocol field in the IP header. */ prot = IPPROTO_AH; m_copyback(m, protoff, sizeof(u_int8_t), (caddr_t) &prot); /* "Massage" the packet headers for crypto processing. */ if ((len = ah_massage_headers(&m, tdb->tdb_dst.sa.sa_family, skip, ahx->type, 1)) != 0) { /* mbuf will be free'd by callee. */ FREE(tc, M_XDATA); crypto_freereq(crp); return len; } } else { /* Update the Next Protocol field in the IP header. */ prot = IPPROTO_AH; m_copyback(m, protoff, sizeof(u_int8_t), (caddr_t) &prot); } /* Crypto operation descriptor. */ crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ crp->crp_flags = CRYPTO_F_IMBUF; crp->crp_buf = (caddr_t) m; crp->crp_callback = (int (*) (struct cryptop *)) ah_output_cb; crp->crp_sid = tdb->tdb_cryptoid; crp->crp_opaque = (caddr_t) tc; /* These are passed as-is to the callback. */ tc->tc_skip = skip; tc->tc_protoff = protoff; tc->tc_spi = tdb->tdb_spi; tc->tc_proto = tdb->tdb_sproto; bcopy(&tdb->tdb_dst, &tc->tc_dst, sizeof(union sockaddr_union)); if ((tdb->tdb_flags & TDBF_SKIPCRYPTO) == 0) return crypto_dispatch(crp); else return ah_output_cb(crp); } /* * AH output callback, called directly from the crypto handler. */ int ah_output_cb(void *op) { int skip, protoff, error; struct tdb_crypto *tc; struct cryptop *crp; struct tdb *tdb; struct mbuf *m; caddr_t ptr; int err, s; crp = (struct cryptop *) op; tc = (struct tdb_crypto *) crp->crp_opaque; skip = tc->tc_skip; protoff = tc->tc_protoff; ptr = (caddr_t) (tc + 1); m = (struct mbuf *) crp->crp_buf; if (m == NULL) { /* Shouldn't happen... */ FREE(tc, M_XDATA); crypto_freereq(crp); ahstat.ahs_crypto++; DPRINTF(("ah_output_cb(): bogus returned buffer from " "crypto\n")); return (EINVAL); } s = spltdb(); tdb = gettdb(tc->tc_spi, &tc->tc_dst, tc->tc_proto); if (tdb == NULL) { FREE(tc, M_XDATA); ahstat.ahs_notdb++; DPRINTF(("ah_output_cb(): TDB is expired while in crypto\n")); error = EPERM; goto baddone; } /* Check for crypto errors. */ if (crp->crp_etype) { if (crp->crp_etype == EAGAIN) { /* Reset the session ID */ if (tdb->tdb_cryptoid != 0) tdb->tdb_cryptoid = crp->crp_sid; splx(s); return crypto_dispatch(crp); } FREE(tc, M_XDATA); ahstat.ahs_noxform++; DPRINTF(("ah_output_cb(): crypto error %d\n", crp->crp_etype)); error = crp->crp_etype; goto baddone; } /* * Copy original headers (with the new protocol number) back * in place. */ if ((tdb->tdb_flags & TDBF_SKIPCRYPTO) == 0) m_copyback(m, 0, skip, ptr); FREE(tc, M_XDATA); /* No longer needed. */ crypto_freereq(crp); err = ipsp_process_done(m, tdb); splx(s); return err; baddone: splx(s); if (m != NULL) m_freem(m); crypto_freereq(crp); return error; }