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NetBSD/sys/netinet6/esp_input.c

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/* $NetBSD: esp_input.c,v 1.50 2011/07/17 20:54:53 joerg Exp $ */
/* $KAME: esp_input.c,v 1.60 2001/09/04 08:43:19 itojun Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* RFC1827/2406 Encapsulated Security Payload.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: esp_input.c,v 1.50 2011/07/17 20:54:53 joerg Exp $");
#include "opt_inet.h"
#include "opt_ipsec.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <net/if.h>
#include <net/route.h>
#include <net/netisr.h>
#include <sys/cpu.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/in_var.h>
#include <netinet/in_proto.h>
#include <netinet/ip_ecn.h>
#include <netinet/ip_icmp.h>
#ifdef INET6
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
#include <netinet6/ip6protosw.h>
#endif
#include <netinet6/ipsec.h>
#include <netinet6/ipsec_private.h>
#include <netinet6/ah.h>
#include <netinet6/esp.h>
#include <netkey/key.h>
#include <netkey/keydb.h>
#include <netkey/key_debug.h>
#include <net/net_osdep.h>
/*#define IPLEN_FLIPPED*/
#define ESPMAXLEN \
(sizeof(struct esp) < sizeof(struct newesp) \
? sizeof(struct newesp) : sizeof(struct esp))
#ifdef INET
void
esp4_init(void)
{
ipsec4_init();
}
void
#if __STDC__
esp4_input(struct mbuf *m, ...)
#else
esp4_input(m, va_alist)
struct mbuf *m;
va_dcl
#endif
{
struct ip *ip;
struct esp *esp;
struct esptail esptail;
u_int32_t spi;
struct secasvar *sav = NULL;
size_t taillen;
u_int16_t nxt;
const struct esp_algorithm *algo;
int ivlen;
size_t hlen;
size_t esplen;
int s;
va_list ap;
int off;
u_int16_t sport = 0;
u_int16_t dport = 0;
#ifdef IPSEC_NAT_T
struct m_tag *tag = NULL;
#endif
va_start(ap, m);
off = va_arg(ap, int);
(void)va_arg(ap, int); /* ignore value, advance ap */
va_end(ap);
/* sanity check for alignment. */
if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
ipseclog((LOG_ERR, "IPv4 ESP input: packet alignment problem "
"(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
IPSEC_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
if (m->m_len < off + ESPMAXLEN) {
m = m_pullup(m, off + ESPMAXLEN);
if (!m) {
ipseclog((LOG_DEBUG,
"IPv4 ESP input: can't pullup in esp4_input\n"));
IPSEC_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
}
#ifdef IPSEC_NAT_T
/* find the source port for NAT_T */
if ((tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL)) != NULL) {
sport = ((u_int16_t *)(tag + 1))[0];
dport = ((u_int16_t *)(tag + 1))[1];
}
#endif
ip = mtod(m, struct ip *);
esp = (struct esp *)(((u_int8_t *)ip) + off);
hlen = ip->ip_hl << 2;
/* find the sassoc. */
spi = esp->esp_spi;
if ((sav = key_allocsa(AF_INET,
(void *)&ip->ip_src, (void *)&ip->ip_dst,
IPPROTO_ESP, spi, sport, dport)) == 0) {
ipseclog((LOG_WARNING,
"IPv4 ESP input: no key association found for spi %u\n",
(u_int32_t)ntohl(spi)));
IPSEC_STATINC(IPSEC_STAT_IN_NOSA);
goto bad;
}
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP esp4_input called to allocate SA:%p\n", sav));
if (sav->state != SADB_SASTATE_MATURE &&
sav->state != SADB_SASTATE_DYING) {
ipseclog((LOG_DEBUG,
"IPv4 ESP input: non-mature/dying SA found for spi %u\n",
(u_int32_t)ntohl(spi)));
IPSEC_STATINC(IPSEC_STAT_IN_BADSPI);
goto bad;
}
algo = esp_algorithm_lookup(sav->alg_enc);
if (!algo) {
ipseclog((LOG_DEBUG, "IPv4 ESP input: "
"unsupported encryption algorithm for spi %u\n",
(u_int32_t)ntohl(spi)));
IPSEC_STATINC(IPSEC_STAT_IN_BADSPI);
goto bad;
}
/* check if we have proper ivlen information */
ivlen = sav->ivlen;
if (ivlen < 0) {
ipseclog((LOG_ERR, "inproper ivlen in IPv4 ESP input: %s %s\n",
ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
IPSEC_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay &&
sav->alg_auth && sav->key_auth))
goto noreplaycheck;
if (sav->alg_auth == SADB_X_AALG_NULL ||
sav->alg_auth == SADB_AALG_NONE)
goto noreplaycheck;
/*
* check for sequence number.
*/
if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
; /* okey */
else {
IPSEC_STATINC(IPSEC_STAT_IN_ESPREPLAY);
ipseclog((LOG_WARNING,
"replay packet in IPv4 ESP input: %s %s\n",
ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
goto bad;
}
/* check ICV */
{
u_int8_t sum0[AH_MAXSUMSIZE];
u_int8_t sum[AH_MAXSUMSIZE];
const struct ah_algorithm *sumalgo;
size_t siz;
sumalgo = ah_algorithm_lookup(sav->alg_auth);
if (!sumalgo)
goto noreplaycheck;
siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
if (m->m_pkthdr.len < off + ESPMAXLEN + siz) {
IPSEC_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
if (AH_MAXSUMSIZE < siz) {
ipseclog((LOG_DEBUG,
"internal error: AH_MAXSUMSIZE must be larger than %lu\n",
(u_long)siz));
IPSEC_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
m_copydata(m, m->m_pkthdr.len - siz, siz, (void *)&sum0[0]);
if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n",
ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
IPSEC_STATINC(IPSEC_STAT_IN_ESPAUTHFAIL);
goto bad;
}
if (memcmp(sum0, sum, siz) != 0) {
ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n",
ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
IPSEC_STATINC(IPSEC_STAT_IN_ESPAUTHFAIL);
goto bad;
}
/* strip off the authentication data */
m_adj(m, -siz);
ip = mtod(m, struct ip *);
#ifdef IPLEN_FLIPPED
ip->ip_len = ip->ip_len - siz;
#else
ip->ip_len = htons(ntohs(ip->ip_len) - siz);
#endif
m->m_flags |= M_AUTHIPDGM;
IPSEC_STATINC(IPSEC_STAT_IN_ESPAUTHSUCC);
}
/*
* update sequence number.
*/
if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
IPSEC_STATINC(IPSEC_STAT_IN_ESPREPLAY);
goto bad;
}
}
noreplaycheck:
/* process main esp header. */
if (sav->flags & SADB_X_EXT_OLD) {
/* RFC 1827 */
esplen = sizeof(struct esp);
} else {
/* RFC 2406 */
if (sav->flags & SADB_X_EXT_DERIV)
esplen = sizeof(struct esp);
else
esplen = sizeof(struct newesp);
}
if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
ipseclog((LOG_WARNING,
"IPv4 ESP input: packet too short\n"));
IPSEC_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
if (m->m_len < off + esplen + ivlen) {
m = m_pullup(m, off + esplen + ivlen);
if (!m) {
ipseclog((LOG_DEBUG,
"IPv4 ESP input: can't pullup in esp4_input\n"));
IPSEC_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
}
/*
* pre-compute and cache intermediate key
*/
if (esp_schedule(algo, sav) != 0) {
IPSEC_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
/*
* decrypt the packet.
*/
if (!algo->decrypt)
panic("internal error: no decrypt function");
if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
/* m is already freed */
m = NULL;
ipseclog((LOG_ERR, "decrypt fail in IPv4 ESP input: %s\n",
ipsec_logsastr(sav)));
IPSEC_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
IPSEC_STATINC(IPSEC_STAT_IN_ESPHIST + sav->alg_enc);
m->m_flags |= M_DECRYPTED;
/*
* find the trailer of the ESP.
*/
m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
(void *)&esptail);
nxt = esptail.esp_nxt;
taillen = esptail.esp_padlen + sizeof(esptail);
if (m->m_pkthdr.len < taillen ||
m->m_pkthdr.len - taillen < off + esplen + ivlen + sizeof(esptail)) {
ipseclog((LOG_WARNING,
"bad pad length in IPv4 ESP input: %s %s\n",
ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
IPSEC_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
/* strip off the trailing pad area. */
m_adj(m, -taillen);
#ifdef IPLEN_FLIPPED
ip->ip_len = ip->ip_len - taillen;
#else
ip->ip_len = htons(ntohs(ip->ip_len) - taillen);
#endif
/* was it transmitted over the IPsec tunnel SA? */
if (ipsec4_tunnel_validate(ip, nxt, sav)) {
/*
* strip off all the headers that precedes ESP header.
* IP4 xx ESP IP4' payload -> IP4' payload
*
* XXX more sanity checks
* XXX relationship with gif?
*/
u_int8_t tos;
tos = ip->ip_tos;
m_adj(m, off + esplen + ivlen);
if (m->m_len < sizeof(*ip)) {
m = m_pullup(m, sizeof(*ip));
if (!m) {
IPSEC_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
}
ip = mtod(m, struct ip *);
/* ECN consideration. */
ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos);
if (!key_checktunnelsanity(sav, AF_INET,
(void *)&ip->ip_src, (void *)&ip->ip_dst)) {
ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
"in IPv4 ESP input: %s %s\n",
ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
IPSEC_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
key_sa_recordxfer(sav, m);
if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
ipsec_addhist(m, IPPROTO_IPV4, 0) != 0) {
IPSEC_STATINC(IPSEC_STAT_IN_NOMEM);
goto bad;
}
s = splnet();
if (IF_QFULL(&ipintrq)) {
IPSEC_STATINC(IPSEC_STAT_IN_INVAL);
splx(s);
goto bad;
}
IF_ENQUEUE(&ipintrq, m);
m = NULL;
schednetisr(NETISR_IP); /* can be skipped but to make sure */
splx(s);
nxt = IPPROTO_DONE;
} else {
/*
* strip off ESP header and IV.
* even in m_pulldown case, we need to strip off ESP so that
* we can always compute checksum for AH correctly.
*/
size_t stripsiz;
stripsiz = esplen + ivlen;
ip = mtod(m, struct ip *);
ovbcopy((void *)ip, (void *)(((u_char *)ip) + stripsiz), off);
m->m_data += stripsiz;
m->m_len -= stripsiz;
m->m_pkthdr.len -= stripsiz;
ip = mtod(m, struct ip *);
#ifdef IPLEN_FLIPPED
ip->ip_len = ip->ip_len - stripsiz;
#else
ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz);
#endif
ip->ip_p = nxt;
key_sa_recordxfer(sav, m);
if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
IPSEC_STATINC(IPSEC_STAT_IN_NOMEM);
goto bad;
}
if (nxt != IPPROTO_DONE) {
if ((inetsw[ip_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
ipsec4_in_reject(m, NULL)) {
IPSEC_STATINC(IPSEC_STAT_IN_POLVIO);
goto bad;
}
(*inetsw[ip_protox[nxt]].pr_input)(m, off, nxt);
} else
m_freem(m);
m = NULL;
}
if (sav) {
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP esp4_input call free SA:%p\n", sav));
key_freesav(sav);
}
IPSEC_STATINC(IPSEC_STAT_IN_SUCCESS);
return;
bad:
if (sav) {
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP esp4_input call free SA:%p\n", sav));
key_freesav(sav);
}
if (m)
m_freem(m);
return;
}
/* assumes that ip header and esp header are contiguous on mbuf */
void *
esp4_ctlinput(int cmd, const struct sockaddr *sa, void *v)
{
struct ip *ip = v;
struct esp *esp;
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.
*/
esp = (struct esp *)((char *)ip + (ip->ip_hl << 2));
if ((sav = key_allocsa(AF_INET,
(void *) &ip->ip_src,
(void *) &ip->ip_dst,
IPPROTO_ESP, esp->esp_spi,
0, 0)) == NULL)
return NULL;
if (sav->state != SADB_SASTATE_MATURE &&
sav->state != SADB_SASTATE_DYING) {
key_freesav(sav);
return NULL;
}
/* XXX Further validation? */
key_freesav(sav);
/*
* 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);
return NULL;
}
return NULL;
}
#endif /* INET */
#ifdef INET6
void
esp6_init(void)
{
ipsec6_init();
}
int
esp6_input(struct mbuf **mp, int *offp, int proto)
{
struct mbuf *m = *mp;
int off = *offp;
struct ip6_hdr *ip6;
struct esp *esp;
struct esptail esptail;
u_int32_t spi;
struct secasvar *sav = NULL;
size_t taillen;
u_int16_t nxt;
const struct esp_algorithm *algo;
int ivlen;
size_t esplen;
int s;
/* sanity check for alignment. */
if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
ipseclog((LOG_ERR, "IPv6 ESP input: packet alignment problem "
"(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
IPSEC6_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
IP6_EXTHDR_GET(esp, struct esp *, m, off, ESPMAXLEN);
if (esp == NULL) {
IPSEC6_STATINC(IPSEC_STAT_IN_INVAL);
return IPPROTO_DONE;
}
ip6 = mtod(m, struct ip6_hdr *);
if (ntohs(ip6->ip6_plen) == 0) {
ipseclog((LOG_ERR, "IPv6 ESP input: "
"ESP with IPv6 jumbogram is not supported.\n"));
IPSEC6_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
/* find the sassoc. */
spi = esp->esp_spi;
if ((sav = key_allocsa(AF_INET6,
(void *)&ip6->ip6_src, (void *)&ip6->ip6_dst,
IPPROTO_ESP, spi, 0, 0)) == 0) {
ipseclog((LOG_WARNING,
"IPv6 ESP input: no key association found for spi %u\n",
(u_int32_t)ntohl(spi)));
IPSEC6_STATINC(IPSEC_STAT_IN_NOSA);
goto bad;
}
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP esp6_input called to allocate SA:%p\n", sav));
if (sav->state != SADB_SASTATE_MATURE &&
sav->state != SADB_SASTATE_DYING) {
ipseclog((LOG_DEBUG,
"IPv6 ESP input: non-mature/dying SA found for spi %u\n",
(u_int32_t)ntohl(spi)));
IPSEC6_STATINC(IPSEC_STAT_IN_BADSPI);
goto bad;
}
algo = esp_algorithm_lookup(sav->alg_enc);
if (!algo) {
ipseclog((LOG_DEBUG, "IPv6 ESP input: "
"unsupported encryption algorithm for spi %u\n",
(u_int32_t)ntohl(spi)));
IPSEC6_STATINC(IPSEC_STAT_IN_BADSPI);
goto bad;
}
/* check if we have proper ivlen information */
ivlen = sav->ivlen;
if (ivlen < 0) {
ipseclog((LOG_ERR, "inproper ivlen in IPv6 ESP input: %s %s\n",
ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
IPSEC6_STATINC(IPSEC_STAT_IN_BADSPI);
goto bad;
}
if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay &&
sav->alg_auth && sav->key_auth))
goto noreplaycheck;
if (sav->alg_auth == SADB_X_AALG_NULL ||
sav->alg_auth == SADB_AALG_NONE)
goto noreplaycheck;
/*
* check for sequence number.
*/
if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
; /* okey */
else {
IPSEC6_STATINC(IPSEC_STAT_IN_ESPREPLAY);
ipseclog((LOG_WARNING,
"replay packet in IPv6 ESP input: %s %s\n",
ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
goto bad;
}
/* check ICV */
{
u_char sum0[AH_MAXSUMSIZE];
u_char sum[AH_MAXSUMSIZE];
const struct ah_algorithm *sumalgo;
size_t siz;
sumalgo = ah_algorithm_lookup(sav->alg_auth);
if (!sumalgo)
goto noreplaycheck;
siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
if (m->m_pkthdr.len < off + ESPMAXLEN + siz) {
IPSEC6_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
if (AH_MAXSUMSIZE < siz) {
ipseclog((LOG_DEBUG,
"internal error: AH_MAXSUMSIZE must be larger than %lu\n",
(u_long)siz));
IPSEC6_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
m_copydata(m, m->m_pkthdr.len - siz, siz, (void *)&sum0[0]);
if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
IPSEC6_STATINC(IPSEC_STAT_IN_ESPAUTHFAIL);
goto bad;
}
if (memcmp(sum0, sum, siz) != 0) {
ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
IPSEC6_STATINC(IPSEC_STAT_IN_ESPAUTHFAIL);
goto bad;
}
/* strip off the authentication data */
m_adj(m, -siz);
ip6 = mtod(m, struct ip6_hdr *);
ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - siz);
m->m_flags |= M_AUTHIPDGM;
IPSEC6_STATINC(IPSEC_STAT_IN_ESPAUTHSUCC);
}
/*
* update sequence number.
*/
if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
IPSEC6_STATINC(IPSEC_STAT_IN_ESPREPLAY);
goto bad;
}
}
noreplaycheck:
/* process main esp header. */
if (sav->flags & SADB_X_EXT_OLD) {
/* RFC 1827 */
esplen = sizeof(struct esp);
} else {
/* RFC 2406 */
if (sav->flags & SADB_X_EXT_DERIV)
esplen = sizeof(struct esp);
else
esplen = sizeof(struct newesp);
}
if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
ipseclog((LOG_WARNING,
"IPv6 ESP input: packet too short\n"));
IPSEC6_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
IP6_EXTHDR_GET(esp, struct esp *, m, off, esplen + ivlen);
if (esp == NULL) {
IPSEC6_STATINC(IPSEC_STAT_IN_INVAL);
m = NULL;
goto bad;
}
ip6 = mtod(m, struct ip6_hdr *); /* set it again just in case */
/*
* pre-compute and cache intermediate key
*/
if (esp_schedule(algo, sav) != 0) {
IPSEC6_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
/*
* decrypt the packet.
*/
if (!algo->decrypt)
panic("internal error: no decrypt function");
if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
/* m is already freed */
m = NULL;
ipseclog((LOG_ERR, "decrypt fail in IPv6 ESP input: %s\n",
ipsec_logsastr(sav)));
IPSEC6_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
IPSEC6_STATINC(IPSEC_STAT_IN_ESPHIST + sav->alg_enc);
m->m_flags |= M_DECRYPTED;
/*
* find the trailer of the ESP.
*/
m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
(void *)&esptail);
nxt = esptail.esp_nxt;
taillen = esptail.esp_padlen + sizeof(esptail);
if (m->m_pkthdr.len < taillen
|| m->m_pkthdr.len - taillen < sizeof(struct ip6_hdr)) { /* ? */
ipseclog((LOG_WARNING,
"bad pad length in IPv6 ESP input: %s %s\n",
ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
IPSEC6_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
/* strip off the trailing pad area. */
m_adj(m, -taillen);
ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - taillen);
/* was it transmitted over the IPsec tunnel SA? */
if (ipsec6_tunnel_validate(ip6, nxt, sav)) {
/*
* strip off all the headers that precedes ESP header.
* IP6 xx ESP IP6' payload -> IP6' payload
*
* XXX more sanity checks
* XXX relationship with gif?
*/
u_int32_t flowinfo; /* net endian */
flowinfo = ip6->ip6_flow;
m_adj(m, off + esplen + ivlen);
if (m->m_len < sizeof(*ip6)) {
m = m_pullup(m, sizeof(*ip6));
if (!m) {
IPSEC6_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
}
ip6 = mtod(m, struct ip6_hdr *);
/* ECN consideration. */
ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
if (!key_checktunnelsanity(sav, AF_INET6,
(void *)&ip6->ip6_src, (void *)&ip6->ip6_dst)) {
ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
"in IPv6 ESP input: %s %s\n",
ipsec6_logpacketstr(ip6, spi),
ipsec_logsastr(sav)));
IPSEC6_STATINC(IPSEC_STAT_IN_INVAL);
goto bad;
}
key_sa_recordxfer(sav, m);
if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
IPSEC6_STATINC(IPSEC_STAT_IN_NOMEM);
goto bad;
}
s = splnet();
if (IF_QFULL(&ip6intrq)) {
IPSEC6_STATINC(IPSEC_STAT_IN_INVAL);
splx(s);
goto bad;
}
IF_ENQUEUE(&ip6intrq, m);
m = NULL;
schednetisr(NETISR_IPV6); /* can be skipped but to make sure */
splx(s);
nxt = IPPROTO_DONE;
} else {
/*
* strip off ESP header and IV.
* even in m_pulldown case, we need to strip off ESP so that
* we can always compute checksum for AH correctly.
*/
size_t stripsiz;
u_int8_t *prvnxtp;
/*
* Set the next header field of the previous header correctly.
*/
prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
*prvnxtp = nxt;
stripsiz = esplen + ivlen;
ip6 = mtod(m, struct ip6_hdr *);
if (m->m_len >= stripsiz + off) {
(void)memmove((char *)ip6 + stripsiz, ip6, off);
m->m_data += stripsiz;
m->m_len -= stripsiz;
m->m_pkthdr.len -= stripsiz;
} else {
/*
* this comes with no copy if the boundary is on
* cluster
*/
struct mbuf *n;
n = m_split(m, off, M_DONTWAIT);
if (n == NULL) {
/* m is retained by m_split */
goto bad;
}
m_adj(n, stripsiz);
/* m_cat does not update m_pkthdr.len */
m->m_pkthdr.len += n->m_pkthdr.len;
m_cat(m, n);
}
ip6 = mtod(m, struct ip6_hdr *);
ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
key_sa_recordxfer(sav, m);
if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
IPSEC6_STATINC(IPSEC_STAT_IN_NOMEM);
goto bad;
}
}
*offp = off;
*mp = m;
if (sav) {
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP esp6_input call free SA:%p\n", sav));
key_freesav(sav);
}
IPSEC6_STATINC(IPSEC_STAT_IN_SUCCESS);
return nxt;
bad:
if (sav) {
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP esp6_input call free SA:%p\n", sav));
key_freesav(sav);
}
if (m)
m_freem(m);
return IPPROTO_DONE;
}
void *
esp6_ctlinput(int cmd, const struct sockaddr *sa, void *d)
{
const struct newesp *espp;
struct newesp esp;
struct ip6ctlparam *ip6cp = NULL, ip6cp1;
struct secasvar *sav;
struct ip6_hdr *ip6;
struct mbuf *m;
int off;
const struct sockaddr_in6 *sa6_src, *sa6_dst;
if (sa->sa_family != AF_INET6 ||
sa->sa_len != sizeof(struct sockaddr_in6))
return NULL;
if ((unsigned)cmd >= PRC_NCMDS)
return NULL;
/* if the parameter is from icmp6, decode it. */
if (d != NULL) {
ip6cp = (struct ip6ctlparam *)d;
m = ip6cp->ip6c_m;
ip6 = ip6cp->ip6c_ip6;
off = ip6cp->ip6c_off;
} else {
m = NULL;
ip6 = NULL;
off = 0;
}
if (ip6) {
/*
* Notify the error to all possible sockets via pfctlinput2.
* Since the upper layer information (such as protocol type,
* source and destination ports) is embedded in the encrypted
* data and might have been cut, we can't directly call
* an upper layer ctlinput function. However, the pcbnotify
* function will consider source and destination addresses
* as well as the flow info value, and may be able to find
* some PCB that should be notified.
* Although pfctlinput2 will call esp6_ctlinput(), there is
* no possibility of an infinite loop of function calls,
* because we don't pass the inner IPv6 header.
*/
memset(&ip6cp1, 0, sizeof(ip6cp1));
ip6cp1.ip6c_src = ip6cp->ip6c_src;
pfctlinput2(cmd, sa, (void *)&ip6cp1);
/*
* Then go to special cases that need ESP header information.
* XXX: We assume that when ip6 is non NULL,
* M and OFF are valid.
*/
/* check if we can safely examine src and dst ports */
if (m->m_pkthdr.len < off + sizeof(esp))
return NULL;
if (m->m_len < off + sizeof(esp)) {
/*
* this should be rare case,
* so we compromise on this copy...
*/
m_copydata(m, off, sizeof(esp), (void *)&esp);
espp = &esp;
} else
espp = (struct newesp*)(mtod(m, char *) + off);
if (cmd == PRC_MSGSIZE) {
int valid = 0;
/*
* Check to see if we have a valid SA corresponding to
* the address in the ICMP message payload.
*/
sa6_src = ip6cp->ip6c_src;
sa6_dst = (const struct sockaddr_in6 *)sa;
sav = key_allocsa(AF_INET6,
(const void *)&sa6_src->sin6_addr,
(const void *)&sa6_dst->sin6_addr,
IPPROTO_ESP, espp->esp_spi, 0, 0);
if (sav) {
if (sav->state == SADB_SASTATE_MATURE ||
sav->state == SADB_SASTATE_DYING)
valid++;
key_freesav(sav);
}
/* XXX Further validation? */
/*
* Depending on the value of "valid" and routing table
* size (mtudisc_{hi,lo}wat), we will:
* - recalcurate the new MTU and create the
* corresponding routing entry, or
* - ignore the MTU change notification.
*/
icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
}
} else {
/* we normally notify any pcb here */
}
return NULL;
}
#endif /* INET6 */
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