/* $OpenBSD: ip_ah.c,v 1.151 2021/07/18 14:38:20 bluhm 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 "pfsync.h" #include #include #include #include #include #include #include #include #include #include #ifdef INET6 #include #endif /* INET6 */ #include #include #include #include #if NPFSYNC > 0 #include #include #endif /* NPFSYNC > 0 */ #include #include #include "bpfilter.h" #ifdef ENCDEBUG #define DPRINTF(fmt, args...) \ do { \ if (encdebug) \ printf("%s: " fmt "\n", __func__, ## args); \ } while (0) #else #define DPRINTF(fmt, args...) \ do { } while (0) #endif int ah_massage_headers(struct mbuf **, int, int, int, int); const unsigned char ipseczeroes[IPSEC_ZEROES_SIZE]; /* zeroes! */ /* * ah_attach() is called from the transformation initialization code. */ int ah_attach(void) { return 0; } /* * ah_init() is called when an SPI is being set up. */ int ah_init(struct tdb *tdbp, const struct xformsw *xsp, struct ipsecinit *ii) { const struct auth_hash *thash = NULL; struct cryptoini cria, crin; int error; /* 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_X_AALG_RIPEMD160HMAC: thash = &auth_hash_hmac_ripemd_160_96; break; case SADB_X_AALG_SHA2_256: thash = &auth_hash_hmac_sha2_256_128; break; case SADB_X_AALG_SHA2_384: thash = &auth_hash_hmac_sha2_384_192; break; case SADB_X_AALG_SHA2_512: thash = &auth_hash_hmac_sha2_512_256; break; default: DPRINTF("unsupported authentication algorithm %d specified", ii->ii_authalg); return EINVAL; } if (ii->ii_authkeylen != thash->keysize && thash->keysize != 0) { DPRINTF("keylength %d doesn't match algorithm %s keysize (%d)", ii->ii_authkeylen, thash->name, thash->keysize); return EINVAL; } tdbp->tdb_xform = xsp; tdbp->tdb_authalgxform = thash; tdbp->tdb_rpl = AH_HMAC_INITIAL_RPL; DPRINTF("initialized TDB with hash algorithm %s", thash->name); tdbp->tdb_amxkeylen = ii->ii_authkeylen; tdbp->tdb_amxkey = malloc(tdbp->tdb_amxkeylen, M_XDATA, M_WAITOK); memcpy(tdbp->tdb_amxkey, ii->ii_authkey, tdbp->tdb_amxkeylen); /* Initialize crypto session. */ memset(&cria, 0, sizeof(cria)); cria.cri_alg = tdbp->tdb_authalgxform->type; cria.cri_klen = ii->ii_authkeylen * 8; cria.cri_key = ii->ii_authkey; if ((tdbp->tdb_wnd > 0) && (tdbp->tdb_flags & TDBF_ESN)) { memset(&crin, 0, sizeof(crin)); crin.cri_alg = CRYPTO_ESN; cria.cri_next = &crin; } KERNEL_LOCK(); error = crypto_newsession(&tdbp->tdb_cryptoid, &cria, 0); KERNEL_UNLOCK(); return error; } /* * Paranoia. */ int ah_zeroize(struct tdb *tdbp) { int error; if (tdbp->tdb_amxkey) { explicit_bzero(tdbp->tdb_amxkey, tdbp->tdb_amxkeylen); free(tdbp->tdb_amxkey, M_XDATA, tdbp->tdb_amxkeylen); tdbp->tdb_amxkey = NULL; } KERNEL_LOCK(); error = crypto_freesession(tdbp->tdb_cryptoid); KERNEL_UNLOCK(); tdbp->tdb_cryptoid = 0; return error; } /* * Massage IPv4/IPv6 headers for AH processing. */ int ah_massage_headers(struct mbuf **m0, int af, int skip, int alg, int out) { struct mbuf *m = *m0; unsigned char *ptr; int off, count; struct ip *ip; #ifdef INET6 struct ip6_ext *ip6e; struct ip6_hdr ip6; int ad, alloc, nxt, noff, error; #endif /* INET6 */ switch (af) { 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("m_pullup() failed"); ahstat_inc(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; ip->ip_off = 0; ptr = mtod(m, unsigned char *); /* IPv4 option processing */ for (off = sizeof(struct ip); off < skip;) { if (ptr[off] != IPOPT_EOL && ptr[off] != IPOPT_NOP && off + 1 >= skip) { DPRINTF("illegal IPv4 option length " "for option %d", ptr[off]); ahstat_inc(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("illegal IPv4 option length " "for option %d", ptr[off]); ahstat_inc(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("illegal IPv4 option length " "for option %d", ptr[off]); ahstat_inc(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 && ptr[off + 1] >= 2 + sizeof(struct in_addr)) memcpy(&ip->ip_dst, ptr + off + ptr[off + 1] - sizeof(struct in_addr), sizeof(struct in_addr)); /* FALLTHROUGH */ default: /* Sanity check for option length. */ if (ptr[off + 1] < 2) { DPRINTF("illegal IPv4 option length " "for option %d", ptr[off]); ahstat_inc(ahs_hdrops); m_freem(m); return EINVAL; } /* Zeroize all other options. */ count = ptr[off + 1]; memset(ptr + off, 0, count); off += count; break; } /* Sanity check. */ if (off > skip) { DPRINTF("malformed IPv4 options header"); ahstat_inc(ahs_hdrops); m_freem(m); return EINVAL; } } break; #ifdef INET6 case AF_INET6: /* Ugly... */ /* Copy and "cook" the IPv6 header. */ m_copydata(m, 0, sizeof(ip6), &ip6); /* We don't do IPv6 Jumbograms. */ if (ip6.ip6_plen == 0) { DPRINTF("unsupported IPv6 jumbogram"); ahstat_inc(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_EMBED(&ip6.ip6_src)) ip6.ip6_src.s6_addr16[1] = 0; if (IN6_IS_SCOPE_EMBED(&ip6.ip6_dst)) ip6.ip6_dst.s6_addr16[1] = 0; /* Done with IPv6 header. */ error = m_copyback(m, 0, sizeof(struct ip6_hdr), &ip6, M_NOWAIT); if (error) { DPRINTF("m_copyback no memory"); ahstat_inc(ahs_hdrops); m_freem(m); return error; } /* Let's deal with the remaining headers (if any). */ if (skip - sizeof(struct ip6_hdr) > 0) { if (m->m_len <= skip) { ptr = malloc(skip - sizeof(struct ip6_hdr), M_XDATA, M_NOWAIT); if (ptr == NULL) { DPRINTF("failed to allocate " "memory for IPv6 headers"); ahstat_inc(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; nxt = ip6.ip6_nxt; /* Next header type. */ for (off = 0; off < skip - sizeof(struct ip6_hdr);) { if (off + sizeof(struct ip6_ext) > skip - sizeof(struct ip6_hdr)) goto error6; ip6e = (struct ip6_ext *)(ptr + off); switch (nxt) { case IPPROTO_HOPOPTS: case IPPROTO_DSTOPTS: noff = off + ((ip6e->ip6e_len + 1) << 3); /* Sanity check. */ if (noff > skip - sizeof(struct ip6_hdr)) goto error6; /* * Zero out mutable options. */ for (count = off + sizeof(struct ip6_ext); count < noff;) { if (ptr[count] == IP6OPT_PAD1) { count++; continue; /* Skip padding. */ } if (count + 2 > noff) goto error6; ad = ptr[count + 1] + 2; if (count + ad > noff) goto error6; /* If mutable option, zeroize. */ if (ptr[count] & IP6OPT_MUTABLE) memset(ptr + count, 0, ad); count += ad; } if (count != noff) goto error6; break; case IPPROTO_ROUTING: /* * Always include routing headers in * computation. */ { struct ip6_rthdr *rh; rh = (struct ip6_rthdr *)(ptr + off); /* * must adjust content to make it look like * its final form (as seen at the final * destination). * we only know how to massage type 0 routing * header. */ if (out && rh->ip6r_type == IPV6_RTHDR_TYPE_0) { struct ip6_rthdr0 *rh0; struct in6_addr *addr, finaldst; int i; rh0 = (struct ip6_rthdr0 *)rh; addr = (struct in6_addr *)(rh0 + 1); for (i = 0; i < rh0->ip6r0_segleft; i++) if (IN6_IS_SCOPE_EMBED(&addr[i])) addr[i].s6_addr16[1] = 0; finaldst = addr[rh0->ip6r0_segleft - 1]; memmove(&addr[1], &addr[0], sizeof(struct in6_addr) * (rh0->ip6r0_segleft - 1)); m_copydata(m, 0, sizeof(ip6), &ip6); addr[0] = ip6.ip6_dst; ip6.ip6_dst = finaldst; error = m_copyback(m, 0, sizeof(ip6), &ip6, M_NOWAIT); if (error) { if (alloc) free(ptr, M_XDATA, 0); ahstat_inc(ahs_hdrops); m_freem(m); return error; } rh0->ip6r0_segleft = 0; } break; } default: DPRINTF("unexpected IPv6 header type %d", off); error6: if (alloc) free(ptr, M_XDATA, 0); ahstat_inc(ahs_hdrops); m_freem(m); return EINVAL; } /* Advance. */ off += ((ip6e->ip6e_len + 1) << 3); nxt = ip6e->ip6e_nxt; } /* Copyback and free, if we allocated. */ if (alloc) { error = m_copyback(m, sizeof(struct ip6_hdr), skip - sizeof(struct ip6_hdr), ptr, M_NOWAIT); free(ptr, M_XDATA, 0); if (error) { ahstat_inc(ahs_hdrops); m_freem(m); return error; } } 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) { const struct auth_hash *ahx = tdb->tdb_authalgxform; struct tdb_crypto *tc = NULL; u_int32_t btsx, esn; u_int8_t hl; int error, rplen; u_int64_t ibytes; #ifdef ENCDEBUG char buf[INET6_ADDRSTRLEN]; #endif struct cryptodesc *crda = NULL; struct cryptop *crp = NULL; rplen = AH_FLENGTH + sizeof(u_int32_t); /* Save the AH header, we use it throughout. */ m_copydata(m, skip + offsetof(struct ah, ah_hl), sizeof(u_int8_t), &hl); /* Replay window checking, if applicable. */ if (tdb->tdb_wnd > 0) { m_copydata(m, skip + offsetof(struct ah, ah_rpl), sizeof(u_int32_t), &btsx); btsx = ntohl(btsx); switch (checkreplaywindow(tdb, tdb->tdb_rpl, btsx, &esn, 0)) { case 0: /* All's well. */ break; case 1: DPRINTF("replay counter wrapped for SA %s/%08x", ipsp_address(&tdb->tdb_dst, buf, sizeof(buf)), ntohl(tdb->tdb_spi)); ahstat_inc(ahs_wrap); error = ENOBUFS; goto drop; case 2: DPRINTF("old packet received in SA %s/%08x", ipsp_address(&tdb->tdb_dst, buf, sizeof(buf)), ntohl(tdb->tdb_spi)); ahstat_inc(ahs_replay); error = ENOBUFS; goto drop; case 3: DPRINTF("duplicate packet received in SA %s/%08x", ipsp_address(&tdb->tdb_dst, buf, sizeof(buf)), ntohl(tdb->tdb_spi)); ahstat_inc(ahs_replay); error = ENOBUFS; goto drop; default: DPRINTF("bogus value from checkreplaywindow() " "in SA %s/%08x", ipsp_address(&tdb->tdb_dst, buf, sizeof(buf)), ntohl(tdb->tdb_spi)); ahstat_inc(ahs_replay); error = ENOBUFS; goto drop; } } /* Verify AH header length. */ if (hl * sizeof(u_int32_t) != ahx->authsize + rplen - AH_FLENGTH) { DPRINTF("bad authenticator length %ld for packet in SA %s/%08x", hl * sizeof(u_int32_t), ipsp_address(&tdb->tdb_dst, buf, sizeof(buf)), ntohl(tdb->tdb_spi)); ahstat_inc(ahs_badauthl); error = EACCES; goto drop; } if (skip + ahx->authsize + rplen > m->m_pkthdr.len) { DPRINTF("bad mbuf length %d (expecting %d) for packet " "in SA %s/%08x", m->m_pkthdr.len, skip + ahx->authsize + rplen, ipsp_address(&tdb->tdb_dst, buf, sizeof(buf)), ntohl(tdb->tdb_spi)); ahstat_inc(ahs_badauthl); error = EACCES; goto drop; } /* Update the counters. */ ibytes = (m->m_pkthdr.len - skip - hl * sizeof(u_int32_t)); tdb->tdb_cur_bytes += ibytes; tdb->tdb_ibytes += ibytes; ahstat_add(ahs_ibytes, ibytes); /* 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); error = ENXIO; goto drop; } /* 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) { DPRINTF("failed to acquire crypto descriptors"); ahstat_inc(ahs_crypto); error = ENOBUFS; goto drop; } crda = &crp->crp_desc[0]; 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; if ((tdb->tdb_wnd > 0) && (tdb->tdb_flags & TDBF_ESN)) { esn = htonl(esn); memcpy(crda->crd_esn, &esn, 4); crda->crd_flags |= CRD_F_ESN; } /* Allocate IPsec-specific opaque crypto info. */ tc = malloc(sizeof(*tc) + skip + rplen + ahx->authsize, M_XDATA, M_NOWAIT | M_ZERO); if (tc == NULL) { DPRINTF("failed to allocate tdb_crypto"); ahstat_inc(ahs_crypto); error = ENOBUFS; goto drop; } /* * Save the authenticator, the skipped portion of the packet, * and the AH header. */ m_copydata(m, 0, skip + rplen + ahx->authsize, tc + 1); /* Zeroize the authenticator on the packet. */ m_copyback(m, skip + rplen, ahx->authsize, ipseczeroes, M_NOWAIT); /* "Massage" the packet headers for crypto processing. */ error = ah_massage_headers(&m, tdb->tdb_dst.sa.sa_family, skip, ahx->type, 0); if (error) { /* mbuf was freed by callee. */ m = NULL; goto drop; } /* 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 = ipsec_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_rdomain = tdb->tdb_rdomain; memcpy(&tc->tc_dst, &tdb->tdb_dst, sizeof(union sockaddr_union)); tc->tc_rpl = tdb->tdb_rpl; KERNEL_LOCK(); error = crypto_dispatch(crp); KERNEL_UNLOCK(); return error; drop: m_freem(m); crypto_freereq(crp); free(tc, M_XDATA, 0); return error; } int ah_input_cb(struct tdb *tdb, struct tdb_crypto *tc, struct mbuf *m, int clen) { const struct auth_hash *ahx = tdb->tdb_authalgxform; int roff, rplen, skip, protoff; u_int64_t rpl; u_int32_t btsx, esn; caddr_t ptr; unsigned char calc[AH_ALEN_MAX]; struct mbuf *m1, *m0; #ifdef ENCDEBUG char buf[INET6_ADDRSTRLEN]; #endif NET_ASSERT_LOCKED(); skip = tc->tc_skip; protoff = tc->tc_protoff; rpl = tc->tc_rpl; rplen = AH_FLENGTH + sizeof(u_int32_t); /* Copy authenticator off the packet. */ m_copydata(m, skip + rplen, ahx->authsize, calc); ptr = (caddr_t) (tc + 1); /* Verify authenticator. */ if (timingsafe_bcmp(ptr + skip + rplen, calc, ahx->authsize)) { DPRINTF("authentication failed for packet in SA %s/%08x", ipsp_address(&tdb->tdb_dst, buf, sizeof(buf)), ntohl(tdb->tdb_spi)); ahstat_inc(ahs_badauth); 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, M_NOWAIT); /* Replay window checking, if applicable. */ if (tdb->tdb_wnd > 0) { m_copydata(m, skip + offsetof(struct ah, ah_rpl), sizeof(u_int32_t), &btsx); btsx = ntohl(btsx); switch (checkreplaywindow(tdb, rpl, btsx, &esn, 1)) { case 0: /* All's well. */ #if NPFSYNC > 0 pfsync_update_tdb(tdb,0); #endif break; case 1: DPRINTF("replay counter wrapped for SA %s/%08x", ipsp_address(&tdb->tdb_dst, buf, sizeof(buf)), ntohl(tdb->tdb_spi)); ahstat_inc(ahs_wrap); goto baddone; case 2: DPRINTF("old packet received in SA %s/%08x", ipsp_address(&tdb->tdb_dst, buf, sizeof(buf)), ntohl(tdb->tdb_spi)); ahstat_inc(ahs_replay); goto baddone; case 3: DPRINTF("duplicate packet received in SA %s/%08x", ipsp_address(&tdb->tdb_dst, buf, sizeof(buf)), ntohl(tdb->tdb_spi)); ahstat_inc(ahs_replay); goto baddone; default: DPRINTF("bogus value from checkreplaywindow() " "in SA %s/%08x", ipsp_address(&tdb->tdb_dst, buf, sizeof(buf)), ntohl(tdb->tdb_spi)); ahstat_inc(ahs_replay); goto baddone; } } /* Record the beginning of the AH header. */ m1 = m_getptr(m, skip, &roff); if (m1 == NULL) { DPRINTF("bad mbuf chain for packet in SA %s/%08x", ipsp_address(&tdb->tdb_dst, buf, sizeof(buf)), ntohl(tdb->tdb_spi)); ahstat_inc(ahs_hdrops); goto baddone; } /* 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 is the first mbuf, it has set M_PKTHDR and m_adj() * has already adjusted the packet header length for us. */ if (m1 != m) m->m_pkthdr.len -= rplen + ahx->authsize; } else if (roff + rplen + ahx->authsize >= m1->m_len) { int adjlen; /* * 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) { adjlen = roff + rplen + ahx->authsize - m1->m_len; /* Adjust the next mbuf by the remainder. */ m_adj(m1->m_next, adjlen); /* * The second mbuf is guaranteed not * to have a pkthdr... */ m->m_pkthdr.len -= adjlen; } /* 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 */ adjlen = m1->m_len - roff; m_adj(m1, -adjlen); /* * If m1 is the first mbuf, it has set M_PKTHDR and * m_adj() has already adjusted the packet header len. */ if (m1 != m) m->m_pkthdr.len -= adjlen; /* 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; } free(tc, M_XDATA, 0); return ipsec_common_input_cb(m, tdb, skip, protoff); baddone: m_freem(m); free(tc, M_XDATA, 0); return -1; } /* * AH output routine, called by ipsp_process_packet(). */ int ah_output(struct mbuf *m, struct tdb *tdb, struct mbuf **mp, int skip, int protoff) { const struct auth_hash *ahx = tdb->tdb_authalgxform; struct cryptodesc *crda; struct tdb_crypto *tc = NULL; struct mbuf *mi; struct cryptop *crp = NULL; u_int64_t replay64; u_int16_t iplen; int error, rplen, roff; u_int8_t prot; struct ah *ah; #if NBPFILTER > 0 struct ifnet *encif; #ifdef ENCDEBUG char buf[INET6_ADDRSTRLEN]; #endif if ((encif = enc_getif(tdb->tdb_rdomain, tdb->tdb_tap)) != NULL) { encif->if_opackets++; encif->if_obytes += m->m_pkthdr.len; if (encif->if_bpf) { struct enchdr hdr; memset(&hdr, 0, sizeof(hdr)); hdr.af = tdb->tdb_dst.sa.sa_family; hdr.spi = tdb->tdb_spi; hdr.flags |= M_AUTH; bpf_mtap_hdr(encif->if_bpf, (char *)&hdr, ENC_HDRLEN, m, BPF_DIRECTION_OUT); } } #endif ahstat_inc(ahs_output); /* * Check for replay counter wrap-around in automatic (not * manual) keying. */ if ((tdb->tdb_rpl == 0) && (tdb->tdb_wnd > 0)) { DPRINTF("SA %s/%08x should have expired", ipsp_address(&tdb->tdb_dst, buf, sizeof(buf)), ntohl(tdb->tdb_spi)); ahstat_inc(ahs_wrap); error = EINVAL; goto drop; } rplen = AH_FLENGTH + sizeof(u_int32_t); switch (tdb->tdb_dst.sa.sa_family) { case AF_INET: /* Check for IP maximum packet size violations. */ if (rplen + ahx->authsize + m->m_pkthdr.len > IP_MAXPACKET) { DPRINTF("packet in SA %s/%08x got too big", ipsp_address(&tdb->tdb_dst, buf, sizeof(buf)), ntohl(tdb->tdb_spi)); ahstat_inc(ahs_toobig); error = EMSGSIZE; goto drop; } break; #ifdef INET6 case AF_INET6: /* Check for IPv6 maximum packet size violations. */ if (rplen + ahx->authsize + m->m_pkthdr.len > IPV6_MAXPACKET) { DPRINTF("packet in SA %s/%08x got too big", ipsp_address(&tdb->tdb_dst, buf, sizeof(buf)), ntohl(tdb->tdb_spi)); ahstat_inc(ahs_toobig); error = EMSGSIZE; goto drop; } break; #endif /* INET6 */ default: DPRINTF("unknown/unsupported protocol family %d, SA %s/%08x", tdb->tdb_dst.sa.sa_family, ipsp_address(&tdb->tdb_dst, buf, sizeof(buf)), ntohl(tdb->tdb_spi)); ahstat_inc(ahs_nopf); error = EPFNOSUPPORT; goto drop; } /* Update the counters. */ tdb->tdb_cur_bytes += m->m_pkthdr.len - skip; ahstat_add(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); error = EINVAL; goto drop; } /* 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 a readonly mbuf, * copy the packet. */ mi = m; while (mi != NULL && !M_READONLY(mi)) mi = mi->m_next; if (mi != NULL) { struct mbuf *n = m_dup_pkt(m, 0, M_DONTWAIT); if (n == NULL) { ahstat_inc(ahs_hdrops); error = ENOBUFS; goto drop; } m_freem(m); m = n; } /* Inject AH header. */ mi = m_makespace(m, skip, rplen + ahx->authsize, &roff); if (mi == NULL) { DPRINTF("failed to inject AH header for SA %s/%08x", ipsp_address(&tdb->tdb_dst, buf, sizeof(buf)), ntohl(tdb->tdb_spi)); ahstat_inc(ahs_hdrops); error = ENOBUFS; goto drop; } /* * The AH header is guaranteed by m_makespace() to be in * contiguous memory, at 'roff' of the returned mbuf. */ ah = (struct ah *)(mtod(mi, caddr_t) + roff); /* Initialize the AH header. */ m_copydata(m, protoff, sizeof(u_int8_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, M_NOWAIT); replay64 = tdb->tdb_rpl++; ah->ah_rpl = htonl((u_int32_t)replay64); #if NPFSYNC > 0 pfsync_update_tdb(tdb,1); #endif /* Get crypto descriptors. */ crp = crypto_getreq(1); if (crp == NULL) { DPRINTF("failed to acquire crypto descriptors"); ahstat_inc(ahs_crypto); error = ENOBUFS; goto drop; } crda = &crp->crp_desc[0]; 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; if ((tdb->tdb_wnd > 0) && (tdb->tdb_flags & TDBF_ESN)) { u_int32_t esn; esn = htonl((u_int32_t)(replay64 >> 32)); memcpy(crda->crd_esn, &esn, 4); crda->crd_flags |= CRD_F_ESN; } /* Allocate IPsec-specific opaque crypto info. */ tc = malloc(sizeof(*tc) + skip, M_XDATA, M_NOWAIT | M_ZERO); if (tc == NULL) { DPRINTF("failed to allocate tdb_crypto"); ahstat_inc(ahs_crypto); error = ENOBUFS; goto drop; } /* Save the skipped portion of the packet. */ m_copydata(m, 0, skip, 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) { case AF_INET: memcpy((caddr_t) &iplen, ((caddr_t)(tc + 1)) + offsetof(struct ip, ip_len), sizeof(u_int16_t)); iplen = htons(ntohs(iplen) + rplen + ahx->authsize); m_copyback(m, offsetof(struct ip, ip_len), sizeof(u_int16_t), &iplen, M_NOWAIT); break; #ifdef INET6 case AF_INET6: memcpy((caddr_t) &iplen, ((caddr_t)(tc + 1)) + offsetof(struct ip6_hdr, ip6_plen), sizeof(u_int16_t)); iplen = htons(ntohs(iplen) + rplen + ahx->authsize); m_copyback(m, offsetof(struct ip6_hdr, ip6_plen), sizeof(u_int16_t), &iplen, M_NOWAIT); 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), &prot, M_NOWAIT); /* "Massage" the packet headers for crypto processing. */ error = ah_massage_headers(&m, tdb->tdb_dst.sa.sa_family, skip, ahx->type, 1); if (error) { /* mbuf was freed by callee. */ m = NULL; goto drop; } /* 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 = ipsec_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; tc->tc_rdomain = tdb->tdb_rdomain; memcpy(&tc->tc_dst, &tdb->tdb_dst, sizeof(union sockaddr_union)); KERNEL_LOCK(); error = crypto_dispatch(crp); KERNEL_UNLOCK(); return error; drop: m_freem(m); crypto_freereq(crp); free(tc, M_XDATA, 0); return error; } /* * AH output callback. */ int ah_output_cb(struct tdb *tdb, struct tdb_crypto *tc, struct mbuf *m, int ilen, int olen) { int skip = tc->tc_skip; caddr_t ptr = (caddr_t) (tc + 1); /* * Copy original headers (with the new protocol number) back * in place. */ m_copyback(m, 0, skip, ptr, M_NOWAIT); /* No longer needed. */ free(tc, M_XDATA, 0); /* Call the IPsec input callback. */ if (ipsp_process_done(m, tdb)) { ahstat_inc(ahs_outfail); return -1; } return 0; }