NetBSD/sys/netinet6/ah_input.c
itojun 2d6047cff9 make sure to enforce inbound ipsec policy checking, for any protocols on top
of ip (check it when final header is visited).  sync with kame.
XXX kame team will need to re-check policy engine code
2001-03-01 16:31:37 +00:00

1131 lines
27 KiB
C

/* $NetBSD: ah_input.c,v 1.26 2001/03/01 16:31:40 itojun Exp $ */
/* $KAME: ah_input.c,v 1.53 2001/03/01 09:12:08 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.
*/
/*
* RFC1826/2402 authentication header.
*/
#include "opt_inet.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 <machine/cpu.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/ip_ecn.h>
#include <netinet/ip_icmp.h>
#include <netinet/ip6.h>
#ifdef INET6
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
#include <netinet6/ip6protosw.h>
#endif
#include <netinet6/ipsec.h>
#include <netinet6/ah.h>
#include <netkey/key.h>
#include <netkey/keydb.h>
#include <netkey/key_debug.h>
#include <machine/stdarg.h>
#include <net/net_osdep.h>
#define IPLEN_FLIPPED
#ifdef INET
void
#if __STDC__
ah4_input(struct mbuf *m, ...)
#else
ah4_input(m, va_alist)
struct mbuf *m;
va_dcl
#endif
{
struct ip *ip;
struct ah *ah;
u_int32_t spi;
const struct ah_algorithm *algo;
size_t siz;
size_t siz1;
u_char *cksum;
struct secasvar *sav = NULL;
u_int16_t nxt;
size_t hlen;
int s;
int off, proto;
va_list ap;
va_start(ap, m);
off = va_arg(ap, int);
proto = va_arg(ap, int);
va_end(ap);
#ifndef PULLDOWN_TEST
if (m->m_len < off + sizeof(struct newah)) {
m = m_pullup(m, off + sizeof(struct newah));
if (!m) {
ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup;"
"dropping the packet for simplicity\n"));
ipsecstat.in_inval++;
goto fail;
}
}
ip = mtod(m, struct ip *);
ah = (struct ah *)(((caddr_t)ip) + off);
#else
ip = mtod(m, struct ip *);
IP6_EXTHDR_GET(ah, struct ah *, m, off, sizeof(struct newah));
if (ah == NULL) {
ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup;"
"dropping the packet for simplicity\n"));
ipsecstat.in_inval++;
goto fail;
}
#endif
nxt = ah->ah_nxt;
#ifdef _IP_VHL
hlen = IP_VHL_HL(ip->ip_vhl) << 2;
#else
hlen = ip->ip_hl << 2;
#endif
/* find the sassoc. */
spi = ah->ah_spi;
if ((sav = key_allocsa(AF_INET,
(caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
IPPROTO_AH, spi)) == 0) {
ipseclog((LOG_WARNING,
"IPv4 AH input: no key association found for spi %u\n",
(u_int32_t)ntohl(spi)));
ipsecstat.in_nosa++;
goto fail;
}
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP ah4_input called to allocate SA:%p\n", sav));
if (sav->state != SADB_SASTATE_MATURE
&& sav->state != SADB_SASTATE_DYING) {
ipseclog((LOG_DEBUG,
"IPv4 AH input: non-mature/dying SA found for spi %u\n",
(u_int32_t)ntohl(spi)));
ipsecstat.in_badspi++;
goto fail;
}
algo = ah_algorithm_lookup(sav->alg_auth);
if (!algo) {
ipseclog((LOG_DEBUG, "IPv4 AH input: "
"unsupported authentication algorithm for spi %u\n",
(u_int32_t)ntohl(spi)));
ipsecstat.in_badspi++;
goto fail;
}
siz = (*algo->sumsiz)(sav);
siz1 = ((siz + 3) & ~(4 - 1));
/*
* sanity checks for header, 1.
*/
{
int sizoff;
sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
/*
* Here, we do not do "siz1 == siz". This is because the way
* RFC240[34] section 2 is written. They do not require truncation
* to 96 bits.
* For example, Microsoft IPsec stack attaches 160 bits of
* authentication data for both hmac-md5 and hmac-sha1. For hmac-sha1,
* 32 bits of padding is attached.
*
* There are two downsides to this specification.
* They have no real harm, however, they leave us fuzzy feeling.
* - if we attach more than 96 bits of authentication data onto AH,
* we will never notice about possible modification by rogue
* intermediate nodes.
* Since extra bits in AH checksum is never used, this constitutes
* no real issue, however, it is wacky.
* - even if the peer attaches big authentication data, we will never
* notice the difference, since longer authentication data will just
* work.
*
* We may need some clarification in the spec.
*/
if (siz1 < siz) {
ipseclog((LOG_NOTICE, "sum length too short in IPv4 AH input "
"(%lu, should be at least %lu): %s\n",
(u_long)siz1, (u_long)siz,
ipsec4_logpacketstr(ip, spi)));
ipsecstat.in_inval++;
goto fail;
}
if ((ah->ah_len << 2) - sizoff != siz1) {
ipseclog((LOG_NOTICE, "sum length mismatch in IPv4 AH input "
"(%d should be %lu): %s\n",
(ah->ah_len << 2) - sizoff, (u_long)siz1,
ipsec4_logpacketstr(ip, spi)));
ipsecstat.in_inval++;
goto fail;
}
#ifndef PULLDOWN_TEST
if (m->m_len < off + sizeof(struct ah) + sizoff + siz1) {
m = m_pullup(m, off + sizeof(struct ah) + sizoff + siz1);
if (!m) {
ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup\n"));
ipsecstat.in_inval++;
goto fail;
}
ip = mtod(m, struct ip *);
ah = (struct ah *)(((caddr_t)ip) + off);
}
#else
IP6_EXTHDR_GET(ah, struct ah *, m, off,
sizeof(struct ah) + sizoff + siz1);
if (ah == NULL) {
ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup\n"));
ipsecstat.in_inval++;
goto fail;
}
#endif
}
/*
* check for sequence number.
*/
if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
if (ipsec_chkreplay(ntohl(((struct newah *)ah)->ah_seq), sav))
; /*okey*/
else {
ipsecstat.in_ahreplay++;
ipseclog((LOG_WARNING,
"replay packet in IPv4 AH input: %s %s\n",
ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
goto fail;
}
}
/*
* alright, it seems sane. now we are going to check the
* cryptographic checksum.
*/
cksum = malloc(siz1, M_TEMP, M_NOWAIT);
if (!cksum) {
ipseclog((LOG_DEBUG, "IPv4 AH input: "
"couldn't alloc temporary region for cksum\n"));
ipsecstat.in_inval++;
goto fail;
}
{
#if 1
/*
* some of IP header fields are flipped to the host endian.
* convert them back to network endian. VERY stupid.
*/
ip->ip_len = htons(ip->ip_len);
ip->ip_off = htons(ip->ip_off);
#endif
if (ah4_calccksum(m, (caddr_t)cksum, siz1, algo, sav)) {
free(cksum, M_TEMP);
ipsecstat.in_inval++;
goto fail;
}
ipsecstat.in_ahhist[sav->alg_auth]++;
#if 1
/*
* flip them back.
*/
ip->ip_len = ntohs(ip->ip_len);
ip->ip_off = ntohs(ip->ip_off);
#endif
}
{
caddr_t sumpos = NULL;
if (sav->flags & SADB_X_EXT_OLD) {
/* RFC 1826 */
sumpos = (caddr_t)(ah + 1);
} else {
/* RFC 2402 */
sumpos = (caddr_t)(((struct newah *)ah) + 1);
}
if (bcmp(sumpos, cksum, siz) != 0) {
ipseclog((LOG_WARNING,
"checksum mismatch in IPv4 AH input: %s %s\n",
ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
free(cksum, M_TEMP);
ipsecstat.in_ahauthfail++;
goto fail;
}
}
free(cksum, M_TEMP);
m->m_flags |= M_AUTHIPHDR;
m->m_flags |= M_AUTHIPDGM;
#if 0
/*
* looks okey, but we need more sanity check.
* XXX should elaborate.
*/
if (ah->ah_nxt == IPPROTO_IPIP || ah->ah_nxt == IPPROTO_IP) {
struct ip *nip;
size_t sizoff;
sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
if (m->m_len < off + sizeof(struct ah) + sizoff + siz1 + hlen) {
m = m_pullup(m, off + sizeof(struct ah)
+ sizoff + siz1 + hlen);
if (!m) {
ipseclog((LOG_DEBUG,
"IPv4 AH input: can't pullup\n"));
ipsecstat.in_inval++;
goto fail;
}
}
nip = (struct ip *)((u_char *)(ah + 1) + sizoff + siz1);
if (nip->ip_src.s_addr != ip->ip_src.s_addr
|| nip->ip_dst.s_addr != ip->ip_dst.s_addr) {
m->m_flags &= ~M_AUTHIPHDR;
m->m_flags &= ~M_AUTHIPDGM;
}
}
#ifdef INET6
else if (ah->ah_nxt == IPPROTO_IPV6) {
m->m_flags &= ~M_AUTHIPHDR;
m->m_flags &= ~M_AUTHIPDGM;
}
#endif /*INET6*/
#endif /*0*/
if (m->m_flags & M_AUTHIPHDR
&& m->m_flags & M_AUTHIPDGM) {
#if 0
ipseclog((LOG_DEBUG,
"IPv4 AH input: authentication succeess\n"));
#endif
ipsecstat.in_ahauthsucc++;
} else {
ipseclog((LOG_WARNING,
"authentication failed in IPv4 AH input: %s %s\n",
ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
ipsecstat.in_ahauthfail++;
goto fail;
}
/*
* update sequence number.
*/
if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
if (ipsec_updatereplay(ntohl(((struct newah *)ah)->ah_seq), sav)) {
ipsecstat.in_ahreplay++;
goto fail;
}
}
/* was it transmitted over the IPsec tunnel SA? */
if (ipsec4_tunnel_validate(ip, nxt, sav)) {
/*
* strip off all the headers that precedes AH.
* IP xx AH IP' payload -> IP' payload
*
* XXX more sanity checks
* XXX relationship with gif?
*/
size_t stripsiz = 0;
u_int8_t tos;
tos = ip->ip_tos;
if (sav->flags & SADB_X_EXT_OLD) {
/* RFC 1826 */
stripsiz = sizeof(struct ah) + siz1;
} else {
/* RFC 2402 */
stripsiz = sizeof(struct newah) + siz1;
}
m_adj(m, off + stripsiz);
if (m->m_len < sizeof(*ip)) {
m = m_pullup(m, sizeof(*ip));
if (!m) {
ipsecstat.in_inval++;
goto fail;
}
}
ip = mtod(m, struct ip *);
/* ECN consideration. */
ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos);
if (!key_checktunnelsanity(sav, AF_INET,
(caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
ipseclog((LOG_NOTICE, "ipsec tunnel address mismatch "
"in IPv4 AH input: %s %s\n",
ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
ipsecstat.in_inval++;
goto fail;
}
#if 0 /* XXX should we call ipfw rather than ipsec_in_reject? */
/* drop it if it does not match the default policy */
if (ipsec4_in_reject(m, NULL)) {
ipsecstat.in_polvio++;
goto fail;
}
#endif
#if 1
/*
* Should the inner packet be considered authentic?
* My current answer is: NO.
*
* host1 -- gw1 === gw2 -- host2
* In this case, gw2 can trust the authenticity of the
* outer packet, but NOT inner. Packet may be altered
* between host1 and gw1.
*
* host1 -- gw1 === host2
* This case falls into the same scenario as above.
*
* host1 === host2
* This case is the only case when we may be able to leave
* M_AUTHIPHDR and M_AUTHIPDGM set.
* However, if host1 is wrongly configured, and allows
* attacker to inject some packet with src=host1 and
* dst=host2, you are in risk.
*/
m->m_flags &= ~M_AUTHIPHDR;
m->m_flags &= ~M_AUTHIPDGM;
#endif
key_sa_recordxfer(sav, m);
if (ipsec_addhist(m, IPPROTO_AH, spi) != 0 ||
ipsec_addhist(m, IPPROTO_IPV4, 0) != 0) {
ipsecstat.in_nomem++;
goto fail;
}
s = splimp();
if (IF_QFULL(&ipintrq)) {
ipsecstat.in_inval++;
splx(s);
goto fail;
}
IF_ENQUEUE(&ipintrq, m);
m = NULL;
schednetisr(NETISR_IP); /*can be skipped but to make sure*/
splx(s);
nxt = IPPROTO_DONE;
} else {
/*
* strip off AH.
*/
size_t stripsiz = 0;
if (sav->flags & SADB_X_EXT_OLD) {
/* RFC 1826 */
stripsiz = sizeof(struct ah) + siz1;
} else {
/* RFC 2402 */
stripsiz = sizeof(struct newah) + siz1;
}
ip = mtod(m, struct ip *);
#ifndef PULLDOWN_TEST
/*
* We do deep-copy since KAME requires that
* the packet is placed in a single external mbuf.
*/
ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off);
m->m_data += stripsiz;
m->m_len -= stripsiz;
m->m_pkthdr.len -= stripsiz;
#else
/*
* even in m_pulldown case, we need to strip off AH so that
* we can compute checksum for multiple AH correctly.
*/
if (m->m_len >= stripsiz + off) {
ovbcopy((caddr_t)ip, ((caddr_t)ip) + stripsiz, 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 fail;
}
m_adj(n, stripsiz);
m_cat(m, n);
/* m_cat does not update m_pkthdr.len */
m->m_pkthdr.len += n->m_pkthdr.len;
}
#endif
if (m->m_len < sizeof(*ip)) {
m = m_pullup(m, sizeof(*ip));
if (m == NULL) {
ipsecstat.in_inval++;
goto fail;
}
}
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;
/* forget about IP hdr checksum, the check has already been passed */
key_sa_recordxfer(sav, m);
if (ipsec_addhist(m, IPPROTO_AH, spi) != 0) {
ipsecstat.in_nomem++;
goto fail;
}
if (nxt != IPPROTO_DONE) {
if ((inetsw[ip_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
ipsec4_in_reject(m, NULL)) {
ipsecstat.in_polvio++;
goto fail;
}
(*inetsw[ip_protox[nxt]].pr_input)(m, off, nxt);
} else
m_freem(m);
m = NULL;
}
if (sav) {
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP ah4_input call free SA:%p\n", sav));
key_freesav(sav);
}
ipsecstat.in_success++;
return;
fail:
if (sav) {
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP ah4_input call free SA:%p\n", sav));
key_freesav(sav);
}
if (m)
m_freem(m);
return;
}
/* assumes that ip header and ah header are contiguous on mbuf */
void *
ah4_ctlinput(cmd, sa, v)
int cmd;
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 *)((caddr_t)ip + (ip->ip_hl << 2));
if ((sav = key_allocsa(AF_INET,
(caddr_t) &ip->ip_src,
(caddr_t) &ip->ip_dst,
IPPROTO_AH, ah->ah_spi)) == 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 *)((caddr_t)ip -
offsetof(struct icmp, icmp_ip));
icmp_mtudisc(icp, ip->ip_dst);
return NULL;
}
return NULL;
}
#endif /* INET */
#ifdef INET6
int
ah6_input(mp, offp, proto)
struct mbuf **mp;
int *offp, proto;
{
struct mbuf *m = *mp;
int off = *offp;
struct ip6_hdr *ip6;
struct ah *ah;
u_int32_t spi;
const struct ah_algorithm *algo;
size_t siz;
size_t siz1;
u_char *cksum;
struct secasvar *sav = NULL;
u_int16_t nxt;
int s;
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, sizeof(struct ah), IPPROTO_DONE);
ah = (struct ah *)(mtod(m, caddr_t) + off);
#else
IP6_EXTHDR_GET(ah, struct ah *, m, off, sizeof(struct newah));
if (ah == NULL) {
ipseclog((LOG_DEBUG, "IPv6 AH input: can't pullup\n"));
ipsec6stat.in_inval++;
return IPPROTO_DONE;
}
#endif
ip6 = mtod(m, struct ip6_hdr *);
nxt = ah->ah_nxt;
/* find the sassoc. */
spi = ah->ah_spi;
if (ntohs(ip6->ip6_plen) == 0) {
ipseclog((LOG_ERR, "IPv6 AH input: "
"AH with IPv6 jumbogram is not supported.\n"));
ipsec6stat.in_inval++;
goto fail;
}
if ((sav = key_allocsa(AF_INET6,
(caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
IPPROTO_AH, spi)) == 0) {
ipseclog((LOG_WARNING,
"IPv6 AH input: no key association found for spi %u\n",
(u_int32_t)ntohl(spi)));
ipsec6stat.in_nosa++;
goto fail;
}
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP ah6_input called to allocate SA:%p\n", sav));
if (sav->state != SADB_SASTATE_MATURE
&& sav->state != SADB_SASTATE_DYING) {
ipseclog((LOG_DEBUG,
"IPv6 AH input: non-mature/dying SA found for spi %u; ",
(u_int32_t)ntohl(spi)));
ipsec6stat.in_badspi++;
goto fail;
}
algo = ah_algorithm_lookup(sav->alg_auth);
if (!algo) {
ipseclog((LOG_DEBUG, "IPv6 AH input: "
"unsupported authentication algorithm for spi %u\n",
(u_int32_t)ntohl(spi)));
ipsec6stat.in_badspi++;
goto fail;
}
siz = (*algo->sumsiz)(sav);
siz1 = ((siz + 3) & ~(4 - 1));
/*
* sanity checks for header, 1.
*/
{
int sizoff;
sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
/*
* Here, we do not do "siz1 == siz". See ah4_input() for complete
* description.
*/
if (siz1 < siz) {
ipseclog((LOG_NOTICE, "sum length too short in IPv6 AH input "
"(%lu, should be at least %lu): %s\n",
(u_long)siz1, (u_long)siz,
ipsec6_logpacketstr(ip6, spi)));
ipsec6stat.in_inval++;
goto fail;
}
if ((ah->ah_len << 2) - sizoff != siz1) {
ipseclog((LOG_NOTICE, "sum length mismatch in IPv6 AH input "
"(%d should be %lu): %s\n",
(ah->ah_len << 2) - sizoff, (u_long)siz1,
ipsec6_logpacketstr(ip6, spi)));
ipsec6stat.in_inval++;
goto fail;
}
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, sizeof(struct ah) + sizoff + siz1, IPPROTO_DONE);
#else
IP6_EXTHDR_GET(ah, struct ah *, m, off,
sizeof(struct ah) + sizoff + siz1);
if (ah == NULL) {
ipseclog((LOG_NOTICE, "couldn't pullup gather IPv6 AH checksum part"));
ipsec6stat.in_inval++;
m = NULL;
goto fail;
}
#endif
}
/*
* check for sequence number.
*/
if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
if (ipsec_chkreplay(ntohl(((struct newah *)ah)->ah_seq), sav))
; /*okey*/
else {
ipsec6stat.in_ahreplay++;
ipseclog((LOG_WARNING,
"replay packet in IPv6 AH input: %s %s\n",
ipsec6_logpacketstr(ip6, spi),
ipsec_logsastr(sav)));
goto fail;
}
}
/*
* alright, it seems sane. now we are going to check the
* cryptographic checksum.
*/
cksum = malloc(siz1, M_TEMP, M_NOWAIT);
if (!cksum) {
ipseclog((LOG_DEBUG, "IPv6 AH input: "
"couldn't alloc temporary region for cksum\n"));
ipsec6stat.in_inval++;
goto fail;
}
if (ah6_calccksum(m, (caddr_t)cksum, siz1, algo, sav)) {
free(cksum, M_TEMP);
ipsec6stat.in_inval++;
goto fail;
}
ipsec6stat.in_ahhist[sav->alg_auth]++;
{
caddr_t sumpos = NULL;
if (sav->flags & SADB_X_EXT_OLD) {
/* RFC 1826 */
sumpos = (caddr_t)(ah + 1);
} else {
/* RFC 2402 */
sumpos = (caddr_t)(((struct newah *)ah) + 1);
}
if (bcmp(sumpos, cksum, siz) != 0) {
ipseclog((LOG_WARNING,
"checksum mismatch in IPv6 AH input: %s %s\n",
ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
free(cksum, M_TEMP);
ipsec6stat.in_ahauthfail++;
goto fail;
}
}
free(cksum, M_TEMP);
m->m_flags |= M_AUTHIPHDR;
m->m_flags |= M_AUTHIPDGM;
#if 0
/*
* looks okey, but we need more sanity check.
* XXX should elaborate.
*/
if (ah->ah_nxt == IPPROTO_IPV6) {
struct ip6_hdr *nip6;
size_t sizoff;
sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
IP6_EXTHDR_CHECK(m, off, sizeof(struct ah) + sizoff + siz1
+ sizeof(struct ip6_hdr), IPPROTO_DONE);
nip6 = (struct ip6_hdr *)((u_char *)(ah + 1) + sizoff + siz1);
if (!IN6_ARE_ADDR_EQUAL(&nip6->ip6_src, &ip6->ip6_src)
|| !IN6_ARE_ADDR_EQUAL(&nip6->ip6_dst, &ip6->ip6_dst)) {
m->m_flags &= ~M_AUTHIPHDR;
m->m_flags &= ~M_AUTHIPDGM;
}
} else if (ah->ah_nxt == IPPROTO_IPIP) {
m->m_flags &= ~M_AUTHIPHDR;
m->m_flags &= ~M_AUTHIPDGM;
} else if (ah->ah_nxt == IPPROTO_IP) {
m->m_flags &= ~M_AUTHIPHDR;
m->m_flags &= ~M_AUTHIPDGM;
}
#endif
if (m->m_flags & M_AUTHIPHDR
&& m->m_flags & M_AUTHIPDGM) {
#if 0
ipseclog((LOG_DEBUG,
"IPv6 AH input: authentication succeess\n"));
#endif
ipsec6stat.in_ahauthsucc++;
} else {
ipseclog((LOG_WARNING,
"authentication failed in IPv6 AH input: %s %s\n",
ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
ipsec6stat.in_ahauthfail++;
goto fail;
}
/*
* update sequence number.
*/
if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
if (ipsec_updatereplay(ntohl(((struct newah *)ah)->ah_seq), sav)) {
ipsec6stat.in_ahreplay++;
goto fail;
}
}
/* was it transmitted over the IPsec tunnel SA? */
if (ipsec6_tunnel_validate(ip6, nxt, sav)) {
/*
* strip off all the headers that precedes AH.
* IP6 xx AH IP6' payload -> IP6' payload
*
* XXX more sanity checks
* XXX relationship with gif?
*/
size_t stripsiz = 0;
u_int32_t flowinfo; /*net endian*/
flowinfo = ip6->ip6_flow;
if (sav->flags & SADB_X_EXT_OLD) {
/* RFC 1826 */
stripsiz = sizeof(struct ah) + siz1;
} else {
/* RFC 2402 */
stripsiz = sizeof(struct newah) + siz1;
}
m_adj(m, off + stripsiz);
if (m->m_len < sizeof(*ip6)) {
/*
* m_pullup is prohibited in KAME IPv6 input processing
* but there's no other way!
*/
m = m_pullup(m, sizeof(*ip6));
if (!m) {
ipsec6stat.in_inval++;
goto fail;
}
}
ip6 = mtod(m, struct ip6_hdr *);
/* ECN consideration. */
ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
if (!key_checktunnelsanity(sav, AF_INET6,
(caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
ipseclog((LOG_NOTICE, "ipsec tunnel address mismatch "
"in IPv6 AH input: %s %s\n",
ipsec6_logpacketstr(ip6, spi),
ipsec_logsastr(sav)));
ipsec6stat.in_inval++;
goto fail;
}
#if 0 /* XXX should we call ipfw rather than ipsec_in_reject? */
/* drop it if it does not match the default policy */
if (ipsec6_in_reject(m, NULL)) {
ipsec6stat.in_polvio++;
goto fail;
}
#endif
#if 1
/*
* should the inner packet be considered authentic?
* see comment in ah4_input().
*/
m->m_flags &= ~M_AUTHIPHDR;
m->m_flags &= ~M_AUTHIPDGM;
#endif
key_sa_recordxfer(sav, m);
if (ipsec_addhist(m, IPPROTO_AH, spi) != 0 ||
ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
ipsec6stat.in_nomem++;
goto fail;
}
s = splimp();
if (IF_QFULL(&ip6intrq)) {
ipsec6stat.in_inval++;
splx(s);
goto fail;
}
IF_ENQUEUE(&ip6intrq, m);
m = NULL;
schednetisr(NETISR_IPV6); /*can be skipped but to make sure*/
splx(s);
nxt = IPPROTO_DONE;
} else {
/*
* strip off AH.
*/
size_t stripsiz = 0;
char *prvnxtp;
/*
* Copy the value of the next header field of AH to the
* next header field of the previous header.
* This is necessary because AH will be stripped off below.
*/
prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
*prvnxtp = nxt;
if (sav->flags & SADB_X_EXT_OLD) {
/* RFC 1826 */
stripsiz = sizeof(struct ah) + siz1;
} else {
/* RFC 2402 */
stripsiz = sizeof(struct newah) + siz1;
}
ip6 = mtod(m, struct ip6_hdr *);
#ifndef PULLDOWN_TEST
/*
* We do deep-copy since KAME requires that
* the packet is placed in a single mbuf.
*/
ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
m->m_data += stripsiz;
m->m_len -= stripsiz;
m->m_pkthdr.len -= stripsiz;
#else
/*
* even in m_pulldown case, we need to strip off AH so that
* we can compute checksum for multiple AH correctly.
*/
if (m->m_len >= stripsiz + off) {
ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, 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 fail;
}
m_adj(n, stripsiz);
m_cat(m, n);
/* m_cat does not update m_pkthdr.len */
m->m_pkthdr.len += n->m_pkthdr.len;
}
#endif
ip6 = mtod(m, struct ip6_hdr *);
/* XXX jumbogram */
ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
key_sa_recordxfer(sav, m);
if (ipsec_addhist(m, IPPROTO_AH, spi) != 0) {
ipsec6stat.in_nomem++;
goto fail;
}
}
*offp = off;
*mp = m;
if (sav) {
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP ah6_input call free SA:%p\n", sav));
key_freesav(sav);
}
ipsec6stat.in_success++;
return nxt;
fail:
if (sav) {
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP ah6_input call free SA:%p\n", sav));
key_freesav(sav);
}
if (m)
m_freem(m);
return IPPROTO_DONE;
}
void
ah6_ctlinput(cmd, sa, d)
int cmd;
struct sockaddr *sa;
void *d;
{
const struct newah *ahp;
struct newah ah;
struct secasvar *sav;
struct ip6_hdr *ip6;
struct mbuf *m;
struct ip6ctlparam *ip6cp = NULL;
int off;
struct sockaddr_in6 sa6_src, sa6_dst;
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) {
ip6cp = (struct ip6ctlparam *)d;
m = ip6cp->ip6c_m;
ip6 = ip6cp->ip6c_ip6;
off = ip6cp->ip6c_off;
} else {
m = NULL;
ip6 = NULL;
}
if (ip6) {
/*
* 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(ah))
return;
if (m->m_len < off + sizeof(ah)) {
/*
* this should be rare case,
* so we compromise on this copy...
*/
m_copydata(m, off, sizeof(ah), (caddr_t)&ah);
ahp = &ah;
} else
ahp = (struct newah *)(mtod(m, caddr_t) + 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.
*/
sav = key_allocsa(AF_INET6,
(caddr_t)&sa6_src.sin6_addr,
(caddr_t)&sa6_dst.sin6_addr,
IPPROTO_AH, ahp->ah_spi);
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);
}
/* we normally notify single pcb here */
} else {
/* we normally notify any pcb here */
}
}
#endif /* INET6 */