freebsd-skq/sys/netinet6/ipcomp_input.c
rwatson e68bf7df89 In ipcomp6_input(), check 'md' not 'm' after a call to m_pulldown(): 'm'
may be a stale pointer at this point, and we're interested in whether or
not m_pulldown() failed.

Noticed by:	Coverity Prevent analysis tool
MFC after:	3 days
2006-01-13 23:53:23 +00:00

348 lines
8.1 KiB
C

/* $FreeBSD$ */
/* $KAME: ipcomp_input.c,v 1.25 2001/03/01 09:12:09 itojun Exp $ */
/*-
* Copyright (C) 1999 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.
*/
/*
* RFC2393 IP payload compression protocol (IPComp).
*/
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/systm.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/syslog.h>
#include <net/if.h>
#include <net/route.h>
#include <net/netisr.h>
#include <net/zlib.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>
#ifdef INET6
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#endif
#include <netinet6/ipcomp.h>
#ifdef INET6
#include <netinet6/ipcomp6.h>
#endif
#include <netinet6/ipsec.h>
#ifdef INET6
#include <netinet6/ipsec6.h>
#endif
#include <netkey/key.h>
#include <netkey/keydb.h>
#include <machine/stdarg.h>
#include <net/net_osdep.h>
#define IPLEN_FLIPPED
#ifdef INET
extern struct protosw inetsw[];
void
ipcomp4_input(m, off)
struct mbuf *m;
int off;
{
struct mbuf *md;
struct ip *ip;
struct ipcomp *ipcomp;
const struct ipcomp_algorithm *algo;
u_int16_t cpi; /* host order */
u_int16_t nxt;
size_t hlen;
int error;
size_t newlen, olen;
struct secasvar *sav = NULL;
if (m->m_pkthdr.len < off + sizeof(struct ipcomp)) {
ipseclog((LOG_DEBUG, "IPv4 IPComp input: assumption failed "
"(packet too short)\n"));
ipsecstat.in_inval++;
goto fail;
}
md = m_pulldown(m, off, sizeof(*ipcomp), NULL);
if (!md) {
m = NULL; /* already freed */
ipseclog((LOG_DEBUG, "IPv4 IPComp input: assumption failed "
"(pulldown failure)\n"));
ipsecstat.in_inval++;
goto fail;
}
ipcomp = mtod(md, struct ipcomp *);
ip = mtod(m, struct ip *);
nxt = ipcomp->comp_nxt;
#ifdef _IP_VHL
hlen = IP_VHL_HL(ip->ip_vhl) << 2;
#else
hlen = ip->ip_hl << 2;
#endif
cpi = ntohs(ipcomp->comp_cpi);
if (cpi >= IPCOMP_CPI_NEGOTIATE_MIN) {
sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src,
(caddr_t)&ip->ip_dst, IPPROTO_IPCOMP, htonl(cpi));
if (sav != NULL
&& (sav->state == SADB_SASTATE_MATURE
|| sav->state == SADB_SASTATE_DYING)) {
cpi = sav->alg_enc; /* XXX */
/* other parameters to look at? */
}
}
algo = ipcomp_algorithm_lookup(cpi);
if (!algo) {
ipseclog((LOG_WARNING, "IPv4 IPComp input: unknown cpi %u\n",
cpi));
ipsecstat.in_nosa++;
goto fail;
}
/* chop ipcomp header */
ipcomp = NULL;
md->m_data += sizeof(struct ipcomp);
md->m_len -= sizeof(struct ipcomp);
m->m_pkthdr.len -= sizeof(struct ipcomp);
#ifdef IPLEN_FLIPPED
ip->ip_len -= sizeof(struct ipcomp);
#else
ip->ip_len = htons(ntohs(ip->ip_len) - sizeof(struct ipcomp));
#endif
olen = m->m_pkthdr.len;
newlen = m->m_pkthdr.len - off;
error = (*algo->decompress)(m, m->m_next, &newlen);
if (error != 0) {
if (error == EINVAL)
ipsecstat.in_inval++;
else if (error == ENOBUFS)
ipsecstat.in_nomem++;
m = NULL;
goto fail;
}
ipsecstat.in_comphist[cpi]++;
/*
* returning decompressed packet onto icmp is meaningless.
* mark it decrypted to prevent icmp from attaching original packet.
*/
m->m_flags |= M_DECRYPTED;
m->m_pkthdr.len = off + newlen;
ip = mtod(m, struct ip *);
{
size_t len;
#ifdef IPLEN_FLIPPED
len = ip->ip_len;
#else
len = ntohs(ip->ip_len);
#endif
/*
* be careful about underflow. also, do not assign exact value
* as ip_len is manipulated differently on *BSDs.
*/
len += m->m_pkthdr.len;
len -= olen;
if (len & ~0xffff) {
/* packet too big after decompress */
ipsecstat.in_inval++;
goto fail;
}
#ifdef IPLEN_FLIPPED
ip->ip_len = len & 0xffff;
#else
ip->ip_len = htons(len & 0xffff);
#endif
ip->ip_p = nxt;
}
if (sav) {
key_sa_recordxfer(sav, m);
if (ipsec_addhist(m, IPPROTO_IPCOMP, (u_int32_t)cpi) != 0) {
ipsecstat.in_nomem++;
goto fail;
}
key_freesav(sav);
sav = NULL;
}
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);
} else
m_freem(m);
m = NULL;
ipsecstat.in_success++;
return;
fail:
if (sav)
key_freesav(sav);
if (m)
m_freem(m);
return;
}
#endif /* INET */
#ifdef INET6
int
ipcomp6_input(mp, offp, proto)
struct mbuf **mp;
int *offp, proto;
{
struct mbuf *m, *md;
int off;
struct ip6_hdr *ip6;
struct ipcomp *ipcomp;
const struct ipcomp_algorithm *algo;
u_int16_t cpi; /* host order */
u_int16_t nxt;
int error;
size_t newlen;
struct secasvar *sav = NULL;
u_int8_t *prvnxtp;
m = *mp;
off = *offp;
md = m_pulldown(m, off, sizeof(*ipcomp), NULL);
if (!md) {
m = NULL; /* already freed */
ipseclog((LOG_DEBUG, "IPv6 IPComp input: assumption failed "
"(pulldown failure)\n"));
ipsec6stat.in_inval++;
goto fail;
}
ipcomp = mtod(md, struct ipcomp *);
ip6 = mtod(m, struct ip6_hdr *);
nxt = ipcomp->comp_nxt;
cpi = ntohs(ipcomp->comp_cpi);
if (cpi >= IPCOMP_CPI_NEGOTIATE_MIN) {
sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src,
(caddr_t)&ip6->ip6_dst, IPPROTO_IPCOMP, htonl(cpi));
if (sav != NULL
&& (sav->state == SADB_SASTATE_MATURE
|| sav->state == SADB_SASTATE_DYING)) {
cpi = sav->alg_enc; /* XXX */
/* other parameters to look at? */
}
}
algo = ipcomp_algorithm_lookup(cpi);
if (!algo) {
ipseclog((LOG_WARNING, "IPv6 IPComp input: unknown cpi %u; "
"dropping the packet for simplicity\n", cpi));
ipsec6stat.in_nosa++;
goto fail;
}
/* chop ipcomp header */
ipcomp = NULL;
md->m_data += sizeof(struct ipcomp);
md->m_len -= sizeof(struct ipcomp);
m->m_pkthdr.len -= sizeof(struct ipcomp);
newlen = m->m_pkthdr.len - off;
error = (*algo->decompress)(m, md, &newlen);
if (error != 0) {
if (error == EINVAL)
ipsec6stat.in_inval++;
else if (error == ENOBUFS)
ipsec6stat.in_nomem++;
m = NULL;
goto fail;
}
ipsec6stat.in_comphist[cpi]++;
m->m_pkthdr.len = off + newlen;
/*
* returning decompressed packet onto icmp is meaningless.
* mark it decrypted to prevent icmp from attaching original packet.
*/
m->m_flags |= M_DECRYPTED;
/* update next header field */
prvnxtp = ip6_get_prevhdr(m, off);
*prvnxtp = nxt;
/*
* no need to adjust payload length, as all the IPv6 protocols
* look at m->m_pkthdr.len
*/
if (sav) {
key_sa_recordxfer(sav, m);
if (ipsec_addhist(m, IPPROTO_IPCOMP, (u_int32_t)cpi) != 0) {
ipsec6stat.in_nomem++;
goto fail;
}
key_freesav(sav);
sav = NULL;
}
*offp = off;
*mp = m;
ipsec6stat.in_success++;
return nxt;
fail:
if (m)
m_freem(m);
if (sav)
key_freesav(sav);
return IPPROTO_DONE;
}
#endif /* INET6 */