/* assumes that ip header and ah header are contiguous on mbuf */
void*
ah4_ctlinput(int cmd, const struct sockaddr *sa, void *v)
{
struct ip *ip = v;
struct ah *ah;
struct icmp *icp;
struct secasvar *sav;
if (sa->sa_family != AF_INET ||
sa->sa_len != sizeof(struct sockaddr_in))
return NULL;
if ((unsigned)cmd >= PRC_NCMDS)
return NULL;
if (cmd == PRC_MSGSIZE && ip_mtudisc && ip && ip->ip_v == 4) {
/*
* Check to see if we have a valid SA corresponding to
* the address in the ICMP message payload.
*/
ah = (struct ah *)((char *)ip + (ip->ip_hl << 2));
sav = KEY_ALLOCSA((const union sockaddr_union *)sa,
IPPROTO_AH, ah->ah_spi, 0, 0);
if (sav) {
if (sav->state == SADB_SASTATE_MATURE ||
sav->state == SADB_SASTATE_DYING) {
/*
* Now that we've validated that we are actually
* communicating with the host indicated in the
* ICMP message, locate the ICMP header,
* recalculate the new MTU, and create the
* corresponding routing entry.
*/
icp = (struct icmp *)((char *)ip -
offsetof(struct icmp, icmp_ip));
icmp_mtudisc(icp, ip->ip_dst);
}
KEY_FREESAV(&sav);
}
/*
* ipsec_common_input gets called when an IPsec-protected packet
* is received by IPv4 or IPv6. Its job is to find the right SA
* and call the appropriate transform. The transform callback
* takes care of further processing (like ingress filtering).
*/
int
ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto)
{
char buf[INET6_ADDRSTRLEN];
union sockaddr_union dst_address;
struct secasvar *sav;
u_int32_t spi;
int error;
#ifdef INET
#ifdef IPSEC_NAT_T
struct m_tag *tag;
#endif
#endif
IPSEC_ISTAT(sproto, input);
IPSEC_ASSERT(m != NULL, ("null packet"));
IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
sproto == IPPROTO_IPCOMP,
("unexpected security protocol %u", sproto));
if ((sproto == IPPROTO_ESP && !V_esp_enable) ||
(sproto == IPPROTO_AH && !V_ah_enable) ||
(sproto == IPPROTO_IPCOMP && !V_ipcomp_enable)) {
m_freem(m);
IPSEC_ISTAT(sproto, pdrops);
return EOPNOTSUPP;
}
if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) {
m_freem(m);
IPSEC_ISTAT(sproto, hdrops);
DPRINTF(("%s: packet too small\n", __func__));
return EINVAL;
}
/* Retrieve the SPI from the relevant IPsec header */
if (sproto == IPPROTO_ESP)
m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi);
else if (sproto == IPPROTO_AH)
m_copydata(m, skip + sizeof(u_int32_t), sizeof(u_int32_t),
(caddr_t) &spi);
else if (sproto == IPPROTO_IPCOMP) {
u_int16_t cpi;
m_copydata(m, skip + sizeof(u_int16_t), sizeof(u_int16_t),
(caddr_t) &cpi);
spi = ntohl(htons(cpi));
}
/*
* Find the SA and (indirectly) call the appropriate
* kernel crypto routine. The resulting mbuf chain is a valid
* IP packet ready to go through input processing.
*/
bzero(&dst_address, sizeof (dst_address));
dst_address.sa.sa_family = af;
switch (af) {
#ifdef INET
case AF_INET:
dst_address.sin.sin_len = sizeof(struct sockaddr_in);
m_copydata(m, offsetof(struct ip, ip_dst),
sizeof(struct in_addr),
(caddr_t) &dst_address.sin.sin_addr);
#ifdef IPSEC_NAT_T
/* Find the source port for NAT-T; see udp*_espdecap. */
tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL);
if (tag != NULL)
dst_address.sin.sin_port = ((u_int16_t *)(tag + 1))[1];
#endif /* IPSEC_NAT_T */
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
dst_address.sin6.sin6_len = sizeof(struct sockaddr_in6);
m_copydata(m, offsetof(struct ip6_hdr, ip6_dst),
sizeof(struct in6_addr),
(caddr_t) &dst_address.sin6.sin6_addr);
/* We keep addresses in SADB without embedded scope id */
if (IN6_IS_SCOPE_LINKLOCAL(&dst_address.sin6.sin6_addr)) {
/* XXX: sa6_recoverscope() */
dst_address.sin6.sin6_scope_id =
ntohs(dst_address.sin6.sin6_addr.s6_addr16[1]);
dst_address.sin6.sin6_addr.s6_addr16[1] = 0;
}
break;
#endif /* INET6 */
default:
DPRINTF(("%s: unsupported protocol family %u\n", __func__, af));
m_freem(m);
IPSEC_ISTAT(sproto, nopf);
return EPFNOSUPPORT;
}
/* NB: only pass dst since key_allocsa follows RFC2401 */
sav = KEY_ALLOCSA(&dst_address, sproto, spi);
if (sav == NULL) {
DPRINTF(("%s: no key association found for SA %s/%08lx/%u\n",
__func__, ipsec_address(&dst_address, buf, sizeof(buf)),
(u_long) ntohl(spi), sproto));
IPSEC_ISTAT(sproto, notdb);
m_freem(m);
return ENOENT;
}
if (sav->tdb_xform == NULL) {
DPRINTF(("%s: attempted to use uninitialized SA %s/%08lx/%u\n",
__func__, ipsec_address(&dst_address, buf, sizeof(buf)),
(u_long) ntohl(spi), sproto));
IPSEC_ISTAT(sproto, noxform);
KEY_FREESAV(&sav);
m_freem(m);
return ENXIO;
}
/*
* Call appropriate transform and return -- callback takes care of
* everything else.
*/
error = (*sav->tdb_xform->xf_input)(m, sav, skip, protoff);
KEY_FREESAV(&sav);
return error;
}
/*
* ESP output callback from the crypto driver.
*/
static int
esp_output_cb(struct cryptop *crp)
{
struct tdb_crypto *tc;
struct ipsecrequest *isr;
struct secasvar *sav;
struct mbuf *m;
int s, err, error;
tc = (struct tdb_crypto *) crp->crp_opaque;
KASSERT(tc != NULL, ("esp_output_cb: null opaque data area!"));
m = (struct mbuf *) crp->crp_buf;
s = splnet();
isr = tc->tc_isr;
sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
if (sav == NULL) {
espstat.esps_notdb++;
DPRINTF(("esp_output_cb: SA expired while in crypto "
"(SA %s/%08lx proto %u)\n", ipsec_address(&tc->tc_dst),
(u_long) ntohl(tc->tc_spi), tc->tc_proto));
error = ENOBUFS; /*XXX*/
goto bad;
}
KASSERT(isr->sav == sav,
("esp_output_cb: SA changed was %p now %p\n", isr->sav, sav));
/* Check for crypto errors. */
if (crp->crp_etype) {
/* Reset session ID. */
if (sav->tdb_cryptoid != 0)
sav->tdb_cryptoid = crp->crp_sid;
if (crp->crp_etype == EAGAIN) {
KEY_FREESAV(&sav);
splx(s);
return crypto_dispatch(crp);
}
espstat.esps_noxform++;
DPRINTF(("esp_output_cb: crypto error %d\n", crp->crp_etype));
error = crp->crp_etype;
goto bad;
}
/* Shouldn't happen... */
if (m == NULL) {
espstat.esps_crypto++;
DPRINTF(("esp_output_cb: bogus returned buffer from crypto\n"));
error = EINVAL;
goto bad;
}
espstat.esps_hist[sav->alg_enc]++;
if (sav->tdb_authalgxform != NULL)
ahstat.ahs_hist[sav->alg_auth]++;
/* Release crypto descriptors. */
free(tc, M_XDATA);
crypto_freereq(crp);
/* NB: m is reclaimed by ipsec_process_done. */
err = ipsec_process_done(m, isr);
KEY_FREESAV(&sav);
splx(s);
return err;
bad:
if (sav)
KEY_FREESAV(&sav);
splx(s);
if (m)
m_freem(m);
free(tc, M_XDATA);
crypto_freereq(crp);
return error;
}
/*
* ESP input callback from the crypto driver.
*/
static int
esp_input_cb(struct cryptop *crp)
{
u_int8_t lastthree[3], aalg[AH_HMAC_HASHLEN];
int s, hlen, skip, protoff, error;
struct mbuf *m;
struct cryptodesc *crd;
struct auth_hash *esph;
struct enc_xform *espx;
struct tdb_crypto *tc;
struct m_tag *mtag;
struct secasvar *sav;
struct secasindex *saidx;
caddr_t ptr;
crd = crp->crp_desc;
KASSERT(crd != NULL, ("esp_input_cb: null crypto descriptor!"));
tc = (struct tdb_crypto *) crp->crp_opaque;
KASSERT(tc != NULL, ("esp_input_cb: null opaque crypto data area!"));
skip = tc->tc_skip;
protoff = tc->tc_protoff;
mtag = (struct m_tag *) tc->tc_ptr;
m = (struct mbuf *) crp->crp_buf;
s = splnet();
sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
if (sav == NULL) {
espstat.esps_notdb++;
DPRINTF(("esp_input_cb: SA expired while in crypto "
"(SA %s/%08lx proto %u)\n", ipsec_address(&tc->tc_dst),
(u_long) ntohl(tc->tc_spi), tc->tc_proto));
error = ENOBUFS; /*XXX*/
goto bad;
}
saidx = &sav->sah->saidx;
KASSERT(saidx->dst.sa.sa_family == AF_INET ||
saidx->dst.sa.sa_family == AF_INET6,
("ah_input_cb: unexpected protocol family %u",
saidx->dst.sa.sa_family));
esph = sav->tdb_authalgxform;
espx = sav->tdb_encalgxform;
/* Check for crypto errors */
if (crp->crp_etype) {
/* Reset the session ID */
if (sav->tdb_cryptoid != 0)
sav->tdb_cryptoid = crp->crp_sid;
if (crp->crp_etype == EAGAIN) {
KEY_FREESAV(&sav);
splx(s);
return crypto_dispatch(crp);
}
espstat.esps_noxform++;
DPRINTF(("esp_input_cb: crypto error %d\n", crp->crp_etype));
error = crp->crp_etype;
goto bad;
}
/* Shouldn't happen... */
if (m == NULL) {
espstat.esps_crypto++;
DPRINTF(("esp_input_cb: bogus returned buffer from crypto\n"));
error = EINVAL;
goto bad;
}
espstat.esps_hist[sav->alg_enc]++;
/* If authentication was performed, check now. */
if (esph != NULL) {
/*
* If we have a tag, it means an IPsec-aware NIC did
* the verification for us. Otherwise we need to
* check the authentication calculation.
*/
ahstat.ahs_hist[sav->alg_auth]++;
if (mtag == NULL) {
/* Copy the authenticator from the packet */
m_copydata(m, m->m_pkthdr.len - esph->authsize,
esph->authsize, aalg);
ptr = (caddr_t) (tc + 1);
/* Verify authenticator */
if (bcmp(ptr, aalg, esph->authsize) != 0) {
DPRINTF(("esp_input_cb: "
"authentication hash mismatch for packet in SA %s/%08lx\n",
ipsec_address(&saidx->dst),
(u_long) ntohl(sav->spi)));
espstat.esps_badauth++;
error = EACCES;
goto bad;
}
}
/* Remove trailing authenticator */
m_adj(m, -(esph->authsize));
}
/* Release the crypto descriptors */
free(tc, M_XDATA), tc = NULL;
crypto_freereq(crp), crp = NULL;
/*
* Packet is now decrypted.
*/
m->m_flags |= M_DECRYPTED;
/* Determine the ESP header length */
if (sav->flags & SADB_X_EXT_OLD)
hlen = sizeof (struct esp) + sav->ivlen;
else
hlen = sizeof (struct newesp) + sav->ivlen;
/* Remove the ESP header and IV from the mbuf. */
error = m_striphdr(m, skip, hlen);
if (error) {
espstat.esps_hdrops++;
DPRINTF(("esp_input_cb: bad mbuf chain, SA %s/%08lx\n",
ipsec_address(&sav->sah->saidx.dst),
(u_long) ntohl(sav->spi)));
goto bad;
}
/* Save the last three bytes of decrypted data */
m_copydata(m, m->m_pkthdr.len - 3, 3, lastthree);
/* Verify pad length */
if (lastthree[1] + 2 > m->m_pkthdr.len - skip) {
espstat.esps_badilen++;
DPRINTF(("esp_input_cb: invalid padding length %d "
"for %u byte packet in SA %s/%08lx\n",
lastthree[1], m->m_pkthdr.len - skip,
ipsec_address(&sav->sah->saidx.dst),
(u_long) ntohl(sav->spi)));
error = EINVAL;
goto bad;
}
/* Verify correct decryption by checking the last padding bytes */
if ((sav->flags & SADB_X_EXT_PMASK) != SADB_X_EXT_PRAND) {
if (lastthree[1] != lastthree[0] && lastthree[1] != 0) {
espstat.esps_badenc++;
DPRINTF(("esp_input_cb: decryption failed "
"for packet in SA %s/%08lx\n",
ipsec_address(&sav->sah->saidx.dst),
(u_long) ntohl(sav->spi)));
DPRINTF(("esp_input_cb: %x %x\n", lastthree[0], lastthree[1]));
error = EINVAL;
goto bad;
}
}
/* Trim the mbuf chain to remove trailing authenticator and padding */
m_adj(m, -(lastthree[1] + 2));
/* Restore the Next Protocol field */
m_copyback(m, protoff, sizeof (u_int8_t), lastthree + 2);
IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag);
KEY_FREESAV(&sav);
splx(s);
return error;
bad:
if (sav)
KEY_FREESAV(&sav);
splx(s);
if (m != NULL)
m_freem(m);
if (tc != NULL)
free(tc, M_XDATA);
if (crp != NULL)
crypto_freereq(crp);
return error;
}
/*
* ESP input callback from the crypto driver.
*/
static int
esp_input_cb(struct cryptop *crp)
{
u_int8_t lastthree[3], aalg[AH_ALEN_MAX];
int s, hlen, skip, protoff, error;
struct mbuf *m;
struct cryptodesc *crd;
const struct auth_hash *esph;
const struct enc_xform *espx;
struct tdb_crypto *tc;
struct m_tag *mtag;
struct secasvar *sav;
struct secasindex *saidx;
void *ptr;
u_int16_t dport;
u_int16_t sport;
crd = crp->crp_desc;
IPSEC_ASSERT(crd != NULL, ("esp_input_cb: null crypto descriptor!"));
tc = (struct tdb_crypto *) crp->crp_opaque;
IPSEC_ASSERT(tc != NULL, ("esp_input_cb: null opaque crypto data area!"));
skip = tc->tc_skip;
protoff = tc->tc_protoff;
mtag = (struct m_tag *) tc->tc_ptr;
m = (struct mbuf *) crp->crp_buf;
/* find the source port for NAT-T */
nat_t_ports_get(m, &dport, &sport);
s = splsoftnet();
mutex_enter(softnet_lock);
sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi, sport, dport);
if (sav == NULL) {
ESP_STATINC(ESP_STAT_NOTDB);
DPRINTF(("esp_input_cb: SA expired while in crypto "
"(SA %s/%08lx proto %u)\n", ipsec_address(&tc->tc_dst),
(u_long) ntohl(tc->tc_spi), tc->tc_proto));
error = ENOBUFS; /*XXX*/
goto bad;
}
saidx = &sav->sah->saidx;
IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
saidx->dst.sa.sa_family == AF_INET6,
("esp_input_cb: unexpected protocol family %u",
saidx->dst.sa.sa_family));
esph = sav->tdb_authalgxform;
espx = sav->tdb_encalgxform;
/* Check for crypto errors */
if (crp->crp_etype) {
/* Reset the session ID */
if (sav->tdb_cryptoid != 0)
sav->tdb_cryptoid = crp->crp_sid;
if (crp->crp_etype == EAGAIN) {
KEY_FREESAV(&sav);
mutex_exit(softnet_lock);
splx(s);
return crypto_dispatch(crp);
}
ESP_STATINC(ESP_STAT_NOXFORM);
DPRINTF(("esp_input_cb: crypto error %d\n", crp->crp_etype));
error = crp->crp_etype;
goto bad;
}
/* Shouldn't happen... */
if (m == NULL) {
ESP_STATINC(ESP_STAT_CRYPTO);
DPRINTF(("esp_input_cb: bogus returned buffer from crypto\n"));
error = EINVAL;
goto bad;
}
ESP_STATINC(ESP_STAT_HIST + sav->alg_enc);
/* If authentication was performed, check now. */
if (esph != NULL) {
/*
* If we have a tag, it means an IPsec-aware NIC did
* the verification for us. Otherwise we need to
* check the authentication calculation.
*/
AH_STATINC(AH_STAT_HIST + sav->alg_auth);
if (mtag == NULL) {
/* Copy the authenticator from the packet */
m_copydata(m, m->m_pkthdr.len - esph->authsize,
esph->authsize, aalg);
ptr = (tc + 1);
/* Verify authenticator */
if (!consttime_memequal(ptr, aalg, esph->authsize)) {
DPRINTF(("esp_input_cb: "
"authentication hash mismatch for packet in SA %s/%08lx\n",
ipsec_address(&saidx->dst),
(u_long) ntohl(sav->spi)));
ESP_STATINC(ESP_STAT_BADAUTH);
error = EACCES;
goto bad;
}
}
/* Remove trailing authenticator */
m_adj(m, -(esph->authsize));
}
/* Release the crypto descriptors */
free(tc, M_XDATA), tc = NULL;
crypto_freereq(crp), crp = NULL;
/*
* Packet is now decrypted.
*/
m->m_flags |= M_DECRYPTED;
/*
* Update replay sequence number, if appropriate.
*/
if (sav->replay) {
u_int32_t seq;
m_copydata(m, skip + offsetof(struct newesp, esp_seq),
sizeof (seq), &seq);
if (ipsec_updatereplay(ntohl(seq), sav)) {
DPRINTF(("%s: packet replay check for %s\n", __func__,
ipsec_logsastr(sav)));
ESP_STATINC(ESP_STAT_REPLAY);
error = ENOBUFS;
goto bad;
}
}
/*
* ESP input callback from the crypto driver.
*/
static int
esp_input_cb(struct cryptop *crp)
{
u_int8_t lastthree[3], aalg[AH_HMAC_HASHLEN];
int hlen, skip, protoff, error;
struct mbuf *m;
struct cryptodesc *crd;
struct auth_hash *esph;
struct enc_xform *espx;
struct tdb_crypto *tc;
struct m_tag *mtag;
struct secasvar *sav;
struct secasindex *saidx;
caddr_t ptr;
crd = crp->crp_desc;
IPSEC_ASSERT(crd != NULL, ("null crypto descriptor!"));
tc = (struct tdb_crypto *) crp->crp_opaque;
IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
skip = tc->tc_skip;
protoff = tc->tc_protoff;
mtag = (struct m_tag *) tc->tc_ptr;
m = (struct mbuf *) crp->crp_buf;
sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
if (sav == NULL) {
V_espstat.esps_notdb++;
DPRINTF(("%s: SA gone during crypto (SA %s/%08lx proto %u)\n",
__func__, ipsec_address(&tc->tc_dst),
(u_long) ntohl(tc->tc_spi), tc->tc_proto));
error = ENOBUFS; /*XXX*/
goto bad;
}
saidx = &sav->sah->saidx;
IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
saidx->dst.sa.sa_family == AF_INET6,
("unexpected protocol family %u", saidx->dst.sa.sa_family));
esph = sav->tdb_authalgxform;
espx = sav->tdb_encalgxform;
/* Check for crypto errors */
if (crp->crp_etype) {
/* Reset the session ID */
if (sav->tdb_cryptoid != 0)
sav->tdb_cryptoid = crp->crp_sid;
if (crp->crp_etype == EAGAIN) {
KEY_FREESAV(&sav);
error = crypto_dispatch(crp);
return error;
}
V_espstat.esps_noxform++;
DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
error = crp->crp_etype;
goto bad;
}
/* Shouldn't happen... */
if (m == NULL) {
V_espstat.esps_crypto++;
DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
error = EINVAL;
goto bad;
}
V_espstat.esps_hist[sav->alg_enc]++;
/* If authentication was performed, check now. */
if (esph != NULL) {
/*
* If we have a tag, it means an IPsec-aware NIC did
* the verification for us. Otherwise we need to
* check the authentication calculation.
*/
V_ahstat.ahs_hist[sav->alg_auth]++;
if (mtag == NULL) {
/* Copy the authenticator from the packet */
m_copydata(m, m->m_pkthdr.len - AH_HMAC_HASHLEN,
AH_HMAC_HASHLEN, aalg);
ptr = (caddr_t) (tc + 1);
/* Verify authenticator */
if (bcmp(ptr, aalg, AH_HMAC_HASHLEN) != 0) {
DPRINTF(("%s: "
"authentication hash mismatch for packet in SA %s/%08lx\n",
__func__,
ipsec_address(&saidx->dst),
(u_long) ntohl(sav->spi)));
V_espstat.esps_badauth++;
error = EACCES;
goto bad;
}
}
/* Remove trailing authenticator */
m_adj(m, -AH_HMAC_HASHLEN);
}
/* Release the crypto descriptors */
free(tc, M_XDATA), tc = NULL;
crypto_freereq(crp), crp = NULL;
/*
* Packet is now decrypted.
*/
m->m_flags |= M_DECRYPTED;
/*
* Update replay sequence number, if appropriate.
*/
if (sav->replay) {
u_int32_t seq;
m_copydata(m, skip + offsetof(struct newesp, esp_seq),
sizeof (seq), (caddr_t) &seq);
if (ipsec_updatereplay(ntohl(seq), sav)) {
DPRINTF(("%s: packet replay check for %s\n", __func__,
ipsec_logsastr(sav)));
V_espstat.esps_replay++;
error = ENOBUFS;
goto bad;
}
}
