[apple/xnu.git] / bsd / netinet6 / ipcomp_input.c

/*	$FreeBSD: src/sys/netinet6/ipcomp_input.c,v 1.1.2.2 2001/07/03 11:01:54 ume Exp $	*/
/*	$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 <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 <libkern/zlib.h>
#include <kern/cpu_number.h>
#include <kern/locks.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/kpi_ipfilter_var.h>

#if INET6
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#endif
#include <netinet6/ipcomp.h>
#if INET6
#include <netinet6/ipcomp6.h>
#endif

#include <netinet6/ipsec.h>
#if INET6
#include <netinet6/ipsec6.h>
#endif
#include <netkey/key.h>
#include <netkey/keydb.h>

#include <net/net_osdep.h>

#define IPLEN_FLIPPED

void
ipcomp4_input(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"));
		IPSEC_STAT_INCREMENT(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"));
		IPSEC_STAT_INCREMENT(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));
		IPSEC_STAT_INCREMENT(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) {
			IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
		} else if (error == ENOBUFS)
			IPSEC_STAT_INCREMENT(ipsecstat.in_nomem);
		m = NULL;
		goto fail;
	}
	IPSEC_STAT_INCREMENT(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 */
		IPSEC_STAT_INCREMENT(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) {
			IPSEC_STAT_INCREMENT(ipsecstat.in_nomem);
			goto fail;
		}
		key_freesav(sav, KEY_SADB_UNLOCKED);
		sav = NULL;
	}

	if (nxt != IPPROTO_DONE) {
		if ((ip_protox[nxt]->pr_flags & PR_LASTHDR) != 0 &&
		    ipsec4_in_reject(m, NULL)) {
			IPSEC_STAT_INCREMENT(ipsecstat.in_polvio);
			goto fail;
		}
		ip_proto_dispatch_in(m, off, nxt, 0);
	} else
		m_freem(m);
	m = NULL;

	IPSEC_STAT_INCREMENT(ipsecstat.in_success);
	return;

fail:
	if (sav)
		key_freesav(sav, KEY_SADB_UNLOCKED);

	if (m)
		m_freem(m);
	return;
}

#if INET6
int
ipcomp6_input(mp, offp)
	struct mbuf **mp;
	int *offp;
{
	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;
	char *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"));
		IPSEC_STAT_INCREMENT(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));
		IPSEC_STAT_INCREMENT(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) {
			IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
		} else if (error == ENOBUFS)
			IPSEC_STAT_INCREMENT(ipsec6stat.in_nomem);
		m = NULL;
		goto fail;
	}
	IPSEC_STAT_INCREMENT(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) {
			IPSEC_STAT_INCREMENT(ipsec6stat.in_nomem);
			goto fail;
		}
		key_freesav(sav, KEY_SADB_UNLOCKED);
		sav = NULL;
	}
	*offp = off;
	*mp = m;
	IPSEC_STAT_INCREMENT(ipsec6stat.in_success);
	return nxt;

fail:
	if (m)
		m_freem(m);
	if (sav)
		key_freesav(sav, KEY_SADB_UNLOCKED);
	return IPPROTO_DONE;
}
#endif /* INET6 */
Commit	Line	Data
9bccf70c A	1	/* $FreeBSD: src/sys/netinet6/ipcomp_input.c,v 1.1.2.2 2001/07/03 11:01:54 ume Exp $ */
9bccf70c A	2	/* $KAME: ipcomp_input.c,v 1.25 2001/03/01 09:12:09 itojun Exp $ */
1c79356b A	3
	4	/*
	5	* Copyright (C) 1999 WIDE Project.
	6	* All rights reserved.
	7	*
	8	* Redistribution and use in source and binary forms, with or without
	9	* modification, are permitted provided that the following conditions
	10	* are met:
	11	* 1. Redistributions of source code must retain the above copyright
	12	* notice, this list of conditions and the following disclaimer.
	13	* 2. Redistributions in binary form must reproduce the above copyright
	14	* notice, this list of conditions and the following disclaimer in the
	15	* documentation and/or other materials provided with the distribution.
	16	* 3. Neither the name of the project nor the names of its contributors
	17	* may be used to endorse or promote products derived from this software
	18	* without specific prior written permission.
	19	*
	20	* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
	21	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	22	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	23	* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
	24	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	25	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	26	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	27	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	28	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	29	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	30	* SUCH DAMAGE.
	31	*/
	32
	33	/*
	34	* RFC2393 IP payload compression protocol (IPComp).
	35	*/
	36
1c79356b A	37
	38	#include <sys/param.h>
	39	#include <sys/systm.h>
	40	#include <sys/malloc.h>
	41	#include <sys/mbuf.h>
	42	#include <sys/domain.h>
	43	#include <sys/protosw.h>
	44	#include <sys/socket.h>
	45	#include <sys/errno.h>
	46	#include <sys/time.h>
	47	#include <sys/kernel.h>
	48	#include <sys/syslog.h>
	49
	50	#include <net/if.h>
	51	#include <net/route.h>
2d21ac55	52	#include <libkern/zlib.h>
1c79356b	53	#include <kern/cpu_number.h>
91447636	54	#include <kern/locks.h>
1c79356b A	55
	56	#include <netinet/in.h>
	57	#include <netinet/in_systm.h>
	58	#include <netinet/in_var.h>
	59	#include <netinet/ip.h>
	60	#include <netinet/ip_var.h>
	61	#include <netinet/ip_ecn.h>
2d21ac55	62	#include <netinet/kpi_ipfilter_var.h>
1c79356b A	63
	64	#if INET6
	65	#include <netinet/ip6.h>
	66	#include <netinet6/ip6_var.h>
	67	#endif
	68	#include <netinet6/ipcomp.h>
9bccf70c A	69	#if INET6
	70	#include <netinet6/ipcomp6.h>
	71	#endif
1c79356b A	72
1c79356b A	73	#include <netinet6/ipsec.h>
9bccf70c A	74	#if INET6
	75	#include <netinet6/ipsec6.h>
	76	#endif
1c79356b A	77	#include <netkey/key.h>
1c79356b A	78	#include <netkey/keydb.h>
1c79356b A	79
	80	#include <net/net_osdep.h>
	81
	82	#define IPLEN_FLIPPED
	83
1c79356b A	84	void
	85	ipcomp4_input(struct mbuf *m, int off)
	86	{
9bccf70c	87	struct mbuf *md;
1c79356b A	88	struct ip *ip;
1c79356b A	89	struct ipcomp *ipcomp;
9bccf70c	90	const struct ipcomp_algorithm *algo;
1c79356b A	91	u_int16_t cpi; /* host order */
	92	u_int16_t nxt;
	93	size_t hlen;
	94	int error;
	95	size_t newlen, olen;
	96	struct secasvar *sav = NULL;
	97
	98
9bccf70c	99	if (m->m_pkthdr.len < off + sizeof(struct ipcomp)) {
1c79356b	100	ipseclog((LOG_DEBUG, "IPv4 IPComp input: assumption failed "
9bccf70c	101	"(packet too short)\n"));
2d21ac55	102	IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
1c79356b A	103	goto fail;
1c79356b A	104	}
1c79356b	105
9bccf70c	106	md = m_pulldown(m, off, sizeof(*ipcomp), NULL);
cf7d32b8	107	if (!md) {
9bccf70c A	108	m = NULL; /already freed/
	109	ipseclog((LOG_DEBUG, "IPv4 IPComp input: assumption failed "
	110	"(pulldown failure)\n"));
2d21ac55	111	IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
9bccf70c A	112	goto fail;
	113	}
	114	ipcomp = mtod(md, struct ipcomp *);
1c79356b	115	ip = mtod(m, struct ip *);
1c79356b A	116	nxt = ipcomp->comp_nxt;
	117	#ifdef _IP_VHL
	118	hlen = IP_VHL_HL(ip->ip_vhl) << 2;
	119	#else
	120	hlen = ip->ip_hl << 2;
	121	#endif
	122
	123	cpi = ntohs(ipcomp->comp_cpi);
	124
	125	if (cpi >= IPCOMP_CPI_NEGOTIATE_MIN) {
	126	sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src,
	127	(caddr_t)&ip->ip_dst, IPPROTO_IPCOMP, htonl(cpi));
	128	if (sav != NULL
	129	&& (sav->state == SADB_SASTATE_MATURE
	130	\|\| sav->state == SADB_SASTATE_DYING)) {
	131	cpi = sav->alg_enc; /XXX/
	132	/* other parameters to look at? */
	133	}
	134	}
9bccf70c	135	algo = ipcomp_algorithm_lookup(cpi);
1c79356b A	136	if (!algo) {
	137	ipseclog((LOG_WARNING, "IPv4 IPComp input: unknown cpi %u\n",
	138	cpi));
2d21ac55	139	IPSEC_STAT_INCREMENT(ipsecstat.in_nosa);
1c79356b A	140	goto fail;
	141	}
	142
	143	/* chop ipcomp header */
	144	ipcomp = NULL;
9bccf70c A	145	md->m_data += sizeof(struct ipcomp);
9bccf70c A	146	md->m_len -= sizeof(struct ipcomp);
1c79356b A	147	m->m_pkthdr.len -= sizeof(struct ipcomp);
	148	#ifdef IPLEN_FLIPPED
	149	ip->ip_len -= sizeof(struct ipcomp);
	150	#else
	151	ip->ip_len = htons(ntohs(ip->ip_len) - sizeof(struct ipcomp));
	152	#endif
	153
	154	olen = m->m_pkthdr.len;
	155	newlen = m->m_pkthdr.len - off;
	156	error = (*algo->decompress)(m, m->m_next, &newlen);
	157	if (error != 0) {
2d21ac55 A	158	if (error == EINVAL) {
	159	IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
	160	} else if (error == ENOBUFS)
	161	IPSEC_STAT_INCREMENT(ipsecstat.in_nomem);
1c79356b A	162	m = NULL;
	163	goto fail;
	164	}
2d21ac55	165	IPSEC_STAT_INCREMENT(ipsecstat.in_comphist[cpi]);
1c79356b A	166
	167	/*
	168	* returning decompressed packet onto icmp is meaningless.
	169	* mark it decrypted to prevent icmp from attaching original packet.
	170	*/
	171	m->m_flags \|= M_DECRYPTED;
	172
	173	m->m_pkthdr.len = off + newlen;
	174	ip = mtod(m, struct ip *);
	175	{
	176	size_t len;
	177	#ifdef IPLEN_FLIPPED
	178	len = ip->ip_len;
	179	#else
	180	len = ntohs(ip->ip_len);
	181	#endif
	182	/*
	183	* be careful about underflow. also, do not assign exact value
	184	* as ip_len is manipulated differently on *BSDs.
	185	*/
	186	len += m->m_pkthdr.len;
	187	len -= olen;
	188	if (len & ~0xffff) {
	189	/* packet too big after decompress */
2d21ac55	190	IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
1c79356b A	191	goto fail;
	192	}
	193	#ifdef IPLEN_FLIPPED
	194	ip->ip_len = len & 0xffff;
	195	#else
	196	ip->ip_len = htons(len & 0xffff);
	197	#endif
	198	ip->ip_p = nxt;
	199	}
	200
	201	if (sav) {
	202	key_sa_recordxfer(sav, m);
9bccf70c	203	if (ipsec_addhist(m, IPPROTO_IPCOMP, (u_int32_t)cpi) != 0) {
2d21ac55	204	IPSEC_STAT_INCREMENT(ipsecstat.in_nomem);
9bccf70c A	205	goto fail;
9bccf70c A	206	}
2d21ac55	207	key_freesav(sav, KEY_SADB_UNLOCKED);
1c79356b A	208	sav = NULL;
	209	}
	210
9bccf70c A	211	if (nxt != IPPROTO_DONE) {
	212	if ((ip_protox[nxt]->pr_flags & PR_LASTHDR) != 0 &&
	213	ipsec4_in_reject(m, NULL)) {
2d21ac55	214	IPSEC_STAT_INCREMENT(ipsecstat.in_polvio);
9bccf70c A	215	goto fail;
9bccf70c A	216	}
91447636	217	ip_proto_dispatch_in(m, off, nxt, 0);
9bccf70c	218	} else
1c79356b A	219	m_freem(m);
	220	m = NULL;
	221
2d21ac55	222	IPSEC_STAT_INCREMENT(ipsecstat.in_success);
1c79356b A	223	return;
	224
	225	fail:
	226	if (sav)
2d21ac55	227	key_freesav(sav, KEY_SADB_UNLOCKED);
91447636	228
1c79356b A	229	if (m)
	230	m_freem(m);
	231	return;
	232	}
1c79356b A	233
	234	#if INET6
	235	int
	236	ipcomp6_input(mp, offp)
	237	struct mbuf **mp;
	238	int *offp;
	239	{
	240	struct mbuf m, md;
	241	int off;
	242	struct ip6_hdr *ip6;
1c79356b	243	struct ipcomp *ipcomp;
9bccf70c	244	const struct ipcomp_algorithm *algo;
1c79356b A	245	u_int16_t cpi; /* host order */
	246	u_int16_t nxt;
	247	int error;
	248	size_t newlen;
	249	struct secasvar *sav = NULL;
9bccf70c	250	char *prvnxtp;
1c79356b A	251
	252	m = *mp;
	253	off = *offp;
	254
9bccf70c	255	md = m_pulldown(m, off, sizeof(*ipcomp), NULL);
cf7d32b8	256	if (!md) {
9bccf70c A	257	m = NULL; /already freed/
	258	ipseclog((LOG_DEBUG, "IPv6 IPComp input: assumption failed "
	259	"(pulldown failure)\n"));
2d21ac55	260	IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1c79356b A	261	goto fail;
1c79356b A	262	}
9bccf70c	263	ipcomp = mtod(md, struct ipcomp *);
1c79356b	264	ip6 = mtod(m, struct ip6_hdr *);
1c79356b	265	nxt = ipcomp->comp_nxt;
9bccf70c	266
1c79356b A	267	cpi = ntohs(ipcomp->comp_cpi);
	268
	269	if (cpi >= IPCOMP_CPI_NEGOTIATE_MIN) {
	270	sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src,
	271	(caddr_t)&ip6->ip6_dst, IPPROTO_IPCOMP, htonl(cpi));
	272	if (sav != NULL
	273	&& (sav->state == SADB_SASTATE_MATURE
	274	\|\| sav->state == SADB_SASTATE_DYING)) {
	275	cpi = sav->alg_enc; /XXX/
	276	/* other parameters to look at? */
	277	}
	278	}
9bccf70c	279	algo = ipcomp_algorithm_lookup(cpi);
1c79356b A	280	if (!algo) {
	281	ipseclog((LOG_WARNING, "IPv6 IPComp input: unknown cpi %u; "
	282	"dropping the packet for simplicity\n", cpi));
2d21ac55	283	IPSEC_STAT_INCREMENT(ipsec6stat.in_nosa);
1c79356b A	284	goto fail;
	285	}
	286
9bccf70c A	287	/* chop ipcomp header */
	288	ipcomp = NULL;
	289	md->m_data += sizeof(struct ipcomp);
	290	md->m_len -= sizeof(struct ipcomp);
	291	m->m_pkthdr.len -= sizeof(struct ipcomp);
	292
	293	newlen = m->m_pkthdr.len - off;
1c79356b A	294	error = (*algo->decompress)(m, md, &newlen);
1c79356b A	295	if (error != 0) {
2d21ac55 A	296	if (error == EINVAL) {
	297	IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
	298	} else if (error == ENOBUFS)
	299	IPSEC_STAT_INCREMENT(ipsec6stat.in_nomem);
1c79356b A	300	m = NULL;
	301	goto fail;
	302	}
2d21ac55	303	IPSEC_STAT_INCREMENT(ipsec6stat.in_comphist[cpi]);
9bccf70c	304	m->m_pkthdr.len = off + newlen;
1c79356b A	305
	306	/*
	307	* returning decompressed packet onto icmp is meaningless.
	308	* mark it decrypted to prevent icmp from attaching original packet.
	309	*/
	310	m->m_flags \|= M_DECRYPTED;
	311
9bccf70c	312	/* update next header field */
1c79356b A	313	prvnxtp = ip6_get_prevhdr(m, off);
1c79356b A	314	*prvnxtp = nxt;
1c79356b	315
9bccf70c A	316	/*
	317	* no need to adjust payload length, as all the IPv6 protocols
	318	* look at m->m_pkthdr.len
	319	*/
1c79356b A	320
	321	if (sav) {
	322	key_sa_recordxfer(sav, m);
9bccf70c	323	if (ipsec_addhist(m, IPPROTO_IPCOMP, (u_int32_t)cpi) != 0) {
2d21ac55	324	IPSEC_STAT_INCREMENT(ipsec6stat.in_nomem);
9bccf70c A	325	goto fail;
9bccf70c A	326	}
2d21ac55	327	key_freesav(sav, KEY_SADB_UNLOCKED);
1c79356b A	328	sav = NULL;
	329	}
	330	*offp = off;
	331	*mp = m;
2d21ac55	332	IPSEC_STAT_INCREMENT(ipsec6stat.in_success);
1c79356b A	333	return nxt;
	334
	335	fail:
	336	if (m)
	337	m_freem(m);
	338	if (sav)
2d21ac55	339	key_freesav(sav, KEY_SADB_UNLOCKED);
1c79356b A	340	return IPPROTO_DONE;
	341	}
	342	#endif /* INET6 */