FreeBSD-5.3/sys/netipsec/ipsec_input.c
/* $FreeBSD: src/sys/netipsec/ipsec_input.c,v 1.7.4.1 2004/09/15 15:14:19 andre Exp $ */
/* $OpenBSD: ipsec_input.c,v 1.63 2003/02/20 18:35:43 deraadt 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).
*
* 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.
*
* Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
* Angelos D. Keromytis and Niels Provos.
* 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.
*/
/*
* IPsec input processing.
*/
#include "opt_inet.h"
#include "opt_inet6.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/syslog.h>
#include <net/if.h>
#include <net/route.h>
#include <net/netisr.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/ip6.h>
#ifdef INET6
#include <netinet6/ip6_var.h>
#endif
#include <netinet/in_pcb.h>
#ifdef INET6
#include <netinet/icmp6.h>
#endif
#include <netipsec/ipsec.h>
#ifdef INET6
#include <netipsec/ipsec6.h>
#endif
#include <netipsec/ah_var.h>
#include <netipsec/esp.h>
#include <netipsec/esp_var.h>
#include <netipsec/ipcomp_var.h>
#include <netipsec/key.h>
#include <netipsec/keydb.h>
#include <netipsec/xform.h>
#include <netinet6/ip6protosw.h>
#include <machine/in_cksum.h>
#include <machine/stdarg.h>
#define IPSEC_ISTAT(p,x,y,z) ((p) == IPPROTO_ESP ? (x)++ : \
(p) == IPPROTO_AH ? (y)++ : (z)++)
static void ipsec4_common_ctlinput(int, struct sockaddr *, void *, int);
/*
* ipsec_common_input gets called when an IPsec-protected packet
* is received by IPv4 or IPv6. It's job is to find the right SA
# and call the appropriate transform. The transform callback
* takes care of further processing (like ingress filtering).
*/
static int
ipsec_common_input(struct mbuf *m, int skip, int protoff, int af, int sproto)
{
union sockaddr_union dst_address;
struct secasvar *sav;
u_int32_t spi;
int error;
IPSEC_ISTAT(sproto, espstat.esps_input, ahstat.ahs_input,
ipcompstat.ipcomps_input);
IPSEC_ASSERT(m != NULL, ("null packet"));
if ((sproto == IPPROTO_ESP && !esp_enable) ||
(sproto == IPPROTO_AH && !ah_enable) ||
(sproto == IPPROTO_IPCOMP && !ipcomp_enable)) {
m_freem(m);
IPSEC_ISTAT(sproto, espstat.esps_pdrops, ahstat.ahs_pdrops,
ipcompstat.ipcomps_pdrops);
return EOPNOTSUPP;
}
if (m->m_pkthdr.len - skip < 2 * sizeof (u_int32_t)) {
m_freem(m);
IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops,
ipcompstat.ipcomps_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);
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);
break;
#endif /* INET6 */
default:
DPRINTF(("%s: unsupported protocol family %u\n", __func__, af));
m_freem(m);
IPSEC_ISTAT(sproto, espstat.esps_nopf, ahstat.ahs_nopf,
ipcompstat.ipcomps_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),
(u_long) ntohl(spi), sproto));
IPSEC_ISTAT(sproto, espstat.esps_notdb, ahstat.ahs_notdb,
ipcompstat.ipcomps_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),
(u_long) ntohl(spi), sproto));
IPSEC_ISTAT(sproto, espstat.esps_noxform, ahstat.ahs_noxform,
ipcompstat.ipcomps_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;
}
#ifdef INET
/*
* Common input handler for IPv4 AH, ESP, and IPCOMP.
*/
int
ipsec4_common_input(struct mbuf *m, ...)
{
va_list ap;
int off, nxt;
va_start(ap, m);
off = va_arg(ap, int);
nxt = va_arg(ap, int);
va_end(ap);
return ipsec_common_input(m, off, offsetof(struct ip, ip_p),
AF_INET, nxt);
}
void
ah4_input(struct mbuf *m, int off)
{
ipsec4_common_input(m, off, IPPROTO_AH);
}
void
ah4_ctlinput(int cmd, struct sockaddr *sa, void *v)
{
if (sa->sa_family == AF_INET &&
sa->sa_len == sizeof(struct sockaddr_in))
ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_AH);
}
void
esp4_input(struct mbuf *m, int off)
{
ipsec4_common_input(m, off, IPPROTO_ESP);
}
void
esp4_ctlinput(int cmd, struct sockaddr *sa, void *v)
{
if (sa->sa_family == AF_INET &&
sa->sa_len == sizeof(struct sockaddr_in))
ipsec4_common_ctlinput(cmd, sa, v, IPPROTO_ESP);
}
void
ipcomp4_input(struct mbuf *m, int off)
{
ipsec4_common_input(m, off, IPPROTO_IPCOMP);
}
/*
* IPsec input callback for INET protocols.
* This routine is called as the transform callback.
* Takes care of filtering and other sanity checks on
* the processed packet.
*/
int
ipsec4_common_input_cb(struct mbuf *m, struct secasvar *sav,
int skip, int protoff, struct m_tag *mt)
{
int prot, af, sproto;
struct ip *ip;
struct m_tag *mtag;
struct tdb_ident *tdbi;
struct secasindex *saidx;
int error;
IPSEC_SPLASSERT_SOFTNET(__func__);
IPSEC_ASSERT(m != NULL, ("null mbuf"));
IPSEC_ASSERT(sav != NULL, ("null SA"));
IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
saidx = &sav->sah->saidx;
af = saidx->dst.sa.sa_family;
IPSEC_ASSERT(af == AF_INET, ("unexpected af %u", af));
sproto = saidx->proto;
IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
sproto == IPPROTO_IPCOMP,
("unexpected security protocol %u", sproto));
/* Sanity check */
if (m == NULL) {
DPRINTF(("%s: null mbuf", __func__));
IPSEC_ISTAT(sproto, espstat.esps_badkcr, ahstat.ahs_badkcr,
ipcompstat.ipcomps_badkcr);
KEY_FREESAV(&sav);
return EINVAL;
}
if (skip != 0) {
/* Fix IPv4 header */
if (m->m_len < skip && (m = m_pullup(m, skip)) == NULL) {
DPRINTF(("%s: processing failed for SA %s/%08lx\n",
__func__, ipsec_address(&sav->sah->saidx.dst),
(u_long) ntohl(sav->spi)));
IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops,
ipcompstat.ipcomps_hdrops);
error = ENOBUFS;
goto bad;
}
ip = mtod(m, struct ip *);
ip->ip_len = htons(m->m_pkthdr.len);
ip->ip_off = htons(ip->ip_off);
ip->ip_sum = 0;
ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
} else {
ip = mtod(m, struct ip *);
}
prot = ip->ip_p;
/* IP-in-IP encapsulation */
if (prot == IPPROTO_IPIP) {
struct ip ipn;
if (m->m_pkthdr.len - skip < sizeof(struct ip)) {
IPSEC_ISTAT(sproto, espstat.esps_hdrops,
ahstat.ahs_hdrops,
ipcompstat.ipcomps_hdrops);
error = EINVAL;
goto bad;
}
/* ipn will now contain the inner IPv4 header */
m_copydata(m, ip->ip_hl << 2, sizeof(struct ip),
(caddr_t) &ipn);
#ifdef notyet
/* XXX PROXY address isn't recorded in SAH */
/*
* Check that the inner source address is the same as
* the proxy address, if available.
*/
if ((saidx->proxy.sa.sa_family == AF_INET &&
saidx->proxy.sin.sin_addr.s_addr !=
INADDR_ANY &&
ipn.ip_src.s_addr !=
saidx->proxy.sin.sin_addr.s_addr) ||
(saidx->proxy.sa.sa_family != AF_INET &&
saidx->proxy.sa.sa_family != 0)) {
DPRINTF(("%s: inner source address %s doesn't "
"correspond to expected proxy source %s, "
"SA %s/%08lx\n", __func__,
inet_ntoa4(ipn.ip_src),
ipsp_address(saidx->proxy),
ipsp_address(saidx->dst),
(u_long) ntohl(sav->spi)));
IPSEC_ISTAT(sproto, espstat.esps_pdrops,
ahstat.ahs_pdrops,
ipcompstat.ipcomps_pdrops);
error = EACCES;
goto bad;
}
#endif /*XXX*/
}
#if INET6
/* IPv6-in-IP encapsulation. */
if (prot == IPPROTO_IPV6) {
struct ip6_hdr ip6n;
if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) {
IPSEC_ISTAT(sproto, espstat.esps_hdrops,
ahstat.ahs_hdrops,
ipcompstat.ipcomps_hdrops);
error = EINVAL;
goto bad;
}
/* ip6n will now contain the inner IPv6 header. */
m_copydata(m, ip->ip_hl << 2, sizeof(struct ip6_hdr),
(caddr_t) &ip6n);
#ifdef notyet
/*
* Check that the inner source address is the same as
* the proxy address, if available.
*/
if ((saidx->proxy.sa.sa_family == AF_INET6 &&
!IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
!IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
&saidx->proxy.sin6.sin6_addr)) ||
(saidx->proxy.sa.sa_family != AF_INET6 &&
saidx->proxy.sa.sa_family != 0)) {
DPRINTF(("%s: inner source address %s doesn't "
"correspond to expected proxy source %s, "
"SA %s/%08lx\n", __func__,
ip6_sprintf(&ip6n.ip6_src),
ipsec_address(&saidx->proxy),
ipsec_address(&saidx->dst),
(u_long) ntohl(sav->spi)));
IPSEC_ISTAT(sproto, espstat.esps_pdrops,
ahstat.ahs_pdrops,
ipcompstat.ipcomps_pdrops);
error = EACCES;
goto bad;
}
#endif /*XXX*/
}
#endif /* INET6 */
/*
* Record what we've done to the packet (under what SA it was
* processed). If we've been passed an mtag, it means the packet
* was already processed by an ethernet/crypto combo card and
* thus has a tag attached with all the right information, but
* with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
* PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
*/
if (mt == NULL && sproto != IPPROTO_IPCOMP) {
mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
sizeof(struct tdb_ident), M_NOWAIT);
if (mtag == NULL) {
DPRINTF(("%s: failed to get tag\n", __func__));
IPSEC_ISTAT(sproto, espstat.esps_hdrops,
ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops);
error = ENOMEM;
goto bad;
}
tdbi = (struct tdb_ident *)(mtag + 1);
bcopy(&saidx->dst, &tdbi->dst, saidx->dst.sa.sa_len);
tdbi->proto = sproto;
tdbi->spi = sav->spi;
m_tag_prepend(m, mtag);
} else {
mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
/* XXX do we need to mark m_flags??? */
}
key_sa_recordxfer(sav, m); /* record data transfer */
/*
* Re-dispatch via software interrupt.
*/
if ((error = netisr_queue(NETISR_IP, m))) {
IPSEC_ISTAT(sproto, espstat.esps_qfull, ahstat.ahs_qfull,
ipcompstat.ipcomps_qfull);
DPRINTF(("%s: queue full; proto %u packet dropped\n",
__func__, sproto));
return error;
}
return 0;
bad:
m_freem(m);
return error;
}
void
ipsec4_common_ctlinput(int cmd, struct sockaddr *sa, void *v, int proto)
{
/* XXX nothing just yet */
}
#endif /* INET */
#ifdef INET6
/* IPv6 AH wrapper. */
int
ipsec6_common_input(struct mbuf **mp, int *offp, int proto)
{
int l = 0;
int protoff;
struct ip6_ext ip6e;
if (*offp < sizeof(struct ip6_hdr)) {
DPRINTF(("%s: bad offset %u\n", __func__, *offp));
return IPPROTO_DONE;
} else if (*offp == sizeof(struct ip6_hdr)) {
protoff = offsetof(struct ip6_hdr, ip6_nxt);
} else {
/* Chase down the header chain... */
protoff = sizeof(struct ip6_hdr);
do {
protoff += l;
m_copydata(*mp, protoff, sizeof(ip6e),
(caddr_t) &ip6e);
if (ip6e.ip6e_nxt == IPPROTO_AH)
l = (ip6e.ip6e_len + 2) << 2;
else
l = (ip6e.ip6e_len + 1) << 3;
IPSEC_ASSERT(l > 0, ("l went zero or negative"));
} while (protoff + l < *offp);
/* Malformed packet check */
if (protoff + l != *offp) {
DPRINTF(("%s: bad packet header chain, protoff %u, "
"l %u, off %u\n", __func__, protoff, l, *offp));
IPSEC_ISTAT(proto, espstat.esps_hdrops,
ahstat.ahs_hdrops,
ipcompstat.ipcomps_hdrops);
m_freem(*mp);
*mp = NULL;
return IPPROTO_DONE;
}
protoff += offsetof(struct ip6_ext, ip6e_nxt);
}
(void) ipsec_common_input(*mp, *offp, protoff, AF_INET6, proto);
return IPPROTO_DONE;
}
/*
* IPsec input callback, called by the transform callback. Takes care of
* filtering and other sanity checks on the processed packet.
*/
int
ipsec6_common_input_cb(struct mbuf *m, struct secasvar *sav, int skip, int protoff,
struct m_tag *mt)
{
int prot, af, sproto;
struct ip6_hdr *ip6;
struct m_tag *mtag;
struct tdb_ident *tdbi;
struct secasindex *saidx;
int nxt;
u_int8_t nxt8;
int error, nest;
IPSEC_ASSERT(m != NULL, ("null mbuf"));
IPSEC_ASSERT(sav != NULL, ("null SA"));
IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
saidx = &sav->sah->saidx;
af = saidx->dst.sa.sa_family;
IPSEC_ASSERT(af == AF_INET6, ("unexpected af %u", af));
sproto = saidx->proto;
IPSEC_ASSERT(sproto == IPPROTO_ESP || sproto == IPPROTO_AH ||
sproto == IPPROTO_IPCOMP,
("unexpected security protocol %u", sproto));
/* Sanity check */
if (m == NULL) {
DPRINTF(("%s: null mbuf", __func__));
IPSEC_ISTAT(sproto, espstat.esps_badkcr, ahstat.ahs_badkcr,
ipcompstat.ipcomps_badkcr);
error = EINVAL;
goto bad;
}
/* Fix IPv6 header */
if (m->m_len < sizeof(struct ip6_hdr) &&
(m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
DPRINTF(("%s: processing failed for SA %s/%08lx\n",
__func__, ipsec_address(&sav->sah->saidx.dst),
(u_long) ntohl(sav->spi)));
IPSEC_ISTAT(sproto, espstat.esps_hdrops, ahstat.ahs_hdrops,
ipcompstat.ipcomps_hdrops);
error = EACCES;
goto bad;
}
ip6 = mtod(m, struct ip6_hdr *);
ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
/* Save protocol */
m_copydata(m, protoff, 1, (unsigned char *) &prot);
#ifdef INET
/* IP-in-IP encapsulation */
if (prot == IPPROTO_IPIP) {
struct ip ipn;
if (m->m_pkthdr.len - skip < sizeof(struct ip)) {
IPSEC_ISTAT(sproto, espstat.esps_hdrops,
ahstat.ahs_hdrops,
ipcompstat.ipcomps_hdrops);
error = EINVAL;
goto bad;
}
/* ipn will now contain the inner IPv4 header */
m_copydata(m, skip, sizeof(struct ip), (caddr_t) &ipn);
#ifdef notyet
/*
* Check that the inner source address is the same as
* the proxy address, if available.
*/
if ((saidx->proxy.sa.sa_family == AF_INET &&
saidx->proxy.sin.sin_addr.s_addr != INADDR_ANY &&
ipn.ip_src.s_addr != saidx->proxy.sin.sin_addr.s_addr) ||
(saidx->proxy.sa.sa_family != AF_INET &&
saidx->proxy.sa.sa_family != 0)) {
DPRINTF(("%s: inner source address %s doesn't "
"correspond to expected proxy source %s, "
"SA %s/%08lx\n", __func__,
inet_ntoa4(ipn.ip_src),
ipsec_address(&saidx->proxy),
ipsec_address(&saidx->dst),
(u_long) ntohl(sav->spi)));
IPSEC_ISTATsproto, (espstat.esps_pdrops,
ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops);
error = EACCES;
goto bad;
}
#endif /*XXX*/
}
#endif /* INET */
/* IPv6-in-IP encapsulation */
if (prot == IPPROTO_IPV6) {
struct ip6_hdr ip6n;
if (m->m_pkthdr.len - skip < sizeof(struct ip6_hdr)) {
IPSEC_ISTAT(sproto, espstat.esps_hdrops,
ahstat.ahs_hdrops,
ipcompstat.ipcomps_hdrops);
error = EINVAL;
goto bad;
}
/* ip6n will now contain the inner IPv6 header. */
m_copydata(m, skip, sizeof(struct ip6_hdr),
(caddr_t) &ip6n);
#ifdef notyet
/*
* Check that the inner source address is the same as
* the proxy address, if available.
*/
if ((saidx->proxy.sa.sa_family == AF_INET6 &&
!IN6_IS_ADDR_UNSPECIFIED(&saidx->proxy.sin6.sin6_addr) &&
!IN6_ARE_ADDR_EQUAL(&ip6n.ip6_src,
&saidx->proxy.sin6.sin6_addr)) ||
(saidx->proxy.sa.sa_family != AF_INET6 &&
saidx->proxy.sa.sa_family != 0)) {
DPRINTF(("%s: inner source address %s doesn't "
"correspond to expected proxy source %s, "
"SA %s/%08lx\n", __func__,
ip6_sprintf(&ip6n.ip6_src),
ipsec_address(&saidx->proxy),
ipsec_address(&saidx->dst),
(u_long) ntohl(sav->spi)));
IPSEC_ISTAT(sproto, espstat.esps_pdrops,
ahstat.ahs_pdrops, ipcompstat.ipcomps_pdrops);
error = EACCES;
goto bad;
}
#endif /*XXX*/
}
/*
* Record what we've done to the packet (under what SA it was
* processed). If we've been passed an mtag, it means the packet
* was already processed by an ethernet/crypto combo card and
* thus has a tag attached with all the right information, but
* with a PACKET_TAG_IPSEC_IN_CRYPTO_DONE as opposed to
* PACKET_TAG_IPSEC_IN_DONE type; in that case, just change the type.
*/
if (mt == NULL && sproto != IPPROTO_IPCOMP) {
mtag = m_tag_get(PACKET_TAG_IPSEC_IN_DONE,
sizeof(struct tdb_ident), M_NOWAIT);
if (mtag == NULL) {
DPRINTF(("%s: failed to get tag\n", __func__));
IPSEC_ISTAT(sproto, espstat.esps_hdrops,
ahstat.ahs_hdrops, ipcompstat.ipcomps_hdrops);
error = ENOMEM;
goto bad;
}
tdbi = (struct tdb_ident *)(mtag + 1);
bcopy(&saidx->dst, &tdbi->dst, sizeof(union sockaddr_union));
tdbi->proto = sproto;
tdbi->spi = sav->spi;
m_tag_prepend(m, mtag);
} else {
if (mt != NULL)
mt->m_tag_id = PACKET_TAG_IPSEC_IN_DONE;
/* XXX do we need to mark m_flags??? */
}
key_sa_recordxfer(sav, m);
/* Retrieve new protocol */
m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &nxt8);
/*
* See the end of ip6_input for this logic.
* IPPROTO_IPV[46] case will be processed just like other ones
*/
nest = 0;
nxt = nxt8;
while (nxt != IPPROTO_DONE) {
if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) {
ip6stat.ip6s_toomanyhdr++;
error = EINVAL;
goto bad;
}
/*
* Protection against faulty packet - there should be
* more sanity checks in header chain processing.
*/
if (m->m_pkthdr.len < skip) {
ip6stat.ip6s_tooshort++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
error = EINVAL;
goto bad;
}
/*
* Enforce IPsec policy checking if we are seeing last header.
* note that we do not visit this with protocols with pcb layer
* code - like udp/tcp/raw ip.
*/
if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
ipsec6_in_reject(m, NULL)) {
error = EINVAL;
goto bad;
}
nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &skip, nxt);
}
return 0;
bad:
if (m)
m_freem(m);
return error;
}
void
esp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
{
if (sa->sa_family != AF_INET6 ||
sa->sa_len != sizeof(struct sockaddr_in6))
return;
if ((unsigned)cmd >= PRC_NCMDS)
return;
/* if the parameter is from icmp6, decode it. */
if (d != NULL) {
struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d;
struct mbuf *m = ip6cp->ip6c_m;
int off = ip6cp->ip6c_off;
struct ip6ctlparam ip6cp1;
/*
* 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.
*/
bzero(&ip6cp1, 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.
*/
if (cmd == PRC_MSGSIZE) {
struct secasvar *sav;
u_int32_t spi;
int valid;
/* check header length before using m_copydata */
if (m->m_pkthdr.len < off + sizeof (struct esp))
return;
m_copydata(m, off + offsetof(struct esp, esp_spi),
sizeof(u_int32_t), (caddr_t) &spi);
/*
* Check to see if we have a valid SA corresponding to
* the address in the ICMP message payload.
*/
sav = KEY_ALLOCSA((union sockaddr_union *)sa,
IPPROTO_ESP, spi);
valid = (sav != NULL);
if (sav)
KEY_FREESAV(&sav);
/* XXX Further validation? */
/*
* Depending on whether the SA is "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(ip6cp, valid);
}
} else {
/* we normally notify any pcb here */
}
}
#endif /* INET6 */