File: [local] / sys / netinet / ip_ah.c (download)
Revision 1.1, Tue Mar 4 16:15:43 2008 UTC (16 years, 1 month ago) by nbrk
Branch point for: MAIN
Initial revision
|
/* $OpenBSD: ip_ah.c,v 1.89 2007/02/14 00:53:48 jsg 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 <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>
#include <netinet/ip_var.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>
#if NPFSYNC > 0
#include <net/pfvar.h>
#include <net/if_pfsync.h>
#endif /* NPFSYNC > 0 */
#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_X_AALG_RIPEMD160HMAC:
thash = &auth_hash_hmac_ripemd_160_96;
break;
case SADB_X_AALG_SHA2_256:
thash = &auth_hash_hmac_sha2_256_96;
break;
case SADB_X_AALG_SHA2_384:
thash = &auth_hash_hmac_sha2_384_96;
break;
case SADB_X_AALG_SHA2_512:
thash = &auth_hash_hmac_sha2_512_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 ad, alloc, nxt;
#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 (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
ip->ip_off &= htons(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));
/* FALLTHROUGH */
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_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. */
m_copyback(m, 0, sizeof(struct ip6_hdr), &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;
nxt = ip6.ip6_nxt & 0xff; /* Next header type. */
for (off = 0; off < skip - sizeof(struct ip6_hdr);) {
switch (nxt) {
case IPPROTO_HOPOPTS:
case IPPROTO_DSTOPTS:
ip6e = (struct ip6_ext *) (ptr + off);
/*
* Process the mutable/immutable
* options -- borrows heavily from the
* KAME code.
*/
for (count = off + sizeof(struct ip6_ext);
count < off + ((ip6e->ip6e_len + 1) << 3);) {
if (ptr[count] == IP6OPT_PAD1) {
count++;
continue; /* Skip padding. */
}
/* Sanity check. */
if (count > off +
((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. */
off += ((ip6e->ip6e_len + 1) << 3);
nxt = ip6e->ip6e_nxt;
break;
case IPPROTO_ROUTING:
/*
* Always include routing headers in
* computation.
*/
{
struct ip6_rthdr *rh;
ip6e = (struct ip6_ext *) (ptr + off);
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];
ovbcopy(&addr[0], &addr[1],
sizeof(struct in6_addr) *
(rh0->ip6r0_segleft - 1));
m_copydata(m, 0, sizeof(ip6),
(caddr_t)&ip6);
addr[0] = ip6.ip6_dst;
ip6.ip6_dst = finaldst;
m_copyback(m, 0, sizeof(ip6), &ip6);
rh0->ip6r0_segleft = 0;
}
/* advance */
off += ((ip6e->ip6e_len + 1) << 3);
nxt = 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_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;
#ifdef notyet
/* 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)) {
struct tdb_ident *tdbi;
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;
}
#else
mtag = NULL;
#endif
/* 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. */
#if NPFSYNC > 0
pfsync_update_tdb(tdb,0);
#endif
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 = &(encif[0].sc_if);
ifn->if_opackets++;
ifn->if_obytes += m->m_pkthdr.len;
if (ifn->if_bpf) {
struct enchdr hdr;
bzero (&hdr, sizeof(hdr));
hdr.af = tdb->tdb_dst.sa.sa_family;
hdr.spi = tdb->tdb_spi;
hdr.flags |= M_AUTH | M_AUTH_AH;
bpf_mtap_hdr(ifn->if_bpf, (char *)&hdr, ENC_HDRLEN, m,
BPF_DIRECTION_OUT);
}
#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 a readonly mbuf,
* replace the rest of the chain.
*/
mo = NULL;
mi = m;
while (mi != NULL && !M_READONLY(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++);
#if NPFSYNC > 0
pfsync_update_tdb(tdb,1);
#endif
}
/* 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), &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), &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), &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), &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;
}
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