[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/mcache.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>
#include <mach/sdt.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 *);

	/* Expect 32-bit aligned data pointer on strict-align platforms */
	MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);

	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;
		}

		DTRACE_IP6(receive, struct mbuf *, m, struct inpcb *, NULL,
                        struct ip *, ip, struct ifnet *, m->m_pkthdr.rcvif,
                        struct ip *, ip, struct ip6_hdr *, NULL);

		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(struct mbuf **mp, int *offp, int proto)
{
#pragma unused(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;
	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 *);

	/* Expect 32-bit aligned data pointer on strict-align platforms */
	MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);

	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>
316670eb	42	#include <sys/mcache.h>
1c79356b A	43	#include <sys/domain.h>
	44	#include <sys/protosw.h>
	45	#include <sys/socket.h>
	46	#include <sys/errno.h>
	47	#include <sys/time.h>
	48	#include <sys/kernel.h>
	49	#include <sys/syslog.h>
	50
	51	#include <net/if.h>
	52	#include <net/route.h>
2d21ac55	53	#include <libkern/zlib.h>
1c79356b	54	#include <kern/cpu_number.h>
91447636	55	#include <kern/locks.h>
1c79356b A	56
	57	#include <netinet/in.h>
	58	#include <netinet/in_systm.h>
	59	#include <netinet/in_var.h>
	60	#include <netinet/ip.h>
	61	#include <netinet/ip_var.h>
	62	#include <netinet/ip_ecn.h>
2d21ac55	63	#include <netinet/kpi_ipfilter_var.h>
1c79356b A	64
	65	#if INET6
	66	#include <netinet/ip6.h>
	67	#include <netinet6/ip6_var.h>
	68	#endif
	69	#include <netinet6/ipcomp.h>
9bccf70c A	70	#if INET6
	71	#include <netinet6/ipcomp6.h>
	72	#endif
1c79356b A	73
1c79356b A	74	#include <netinet6/ipsec.h>
9bccf70c A	75	#if INET6
	76	#include <netinet6/ipsec6.h>
	77	#endif
1c79356b A	78	#include <netkey/key.h>
1c79356b A	79	#include <netkey/keydb.h>
1c79356b A	80
1c79356b A	81	#include <net/net_osdep.h>
6d2010ae	82	#include <mach/sdt.h>
1c79356b A	83
	84	#define IPLEN_FLIPPED
	85
1c79356b A	86	void
	87	ipcomp4_input(struct mbuf *m, int off)
	88	{
9bccf70c	89	struct mbuf *md;
1c79356b A	90	struct ip *ip;
1c79356b A	91	struct ipcomp *ipcomp;
9bccf70c	92	const struct ipcomp_algorithm *algo;
1c79356b A	93	u_int16_t cpi; /* host order */
	94	u_int16_t nxt;
	95	size_t hlen;
	96	int error;
	97	size_t newlen, olen;
	98	struct secasvar *sav = NULL;
	99
9bccf70c	100	if (m->m_pkthdr.len < off + sizeof(struct ipcomp)) {
1c79356b	101	ipseclog((LOG_DEBUG, "IPv4 IPComp input: assumption failed "
9bccf70c	102	"(packet too short)\n"));
2d21ac55	103	IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
1c79356b A	104	goto fail;
1c79356b A	105	}
1c79356b	106
9bccf70c	107	md = m_pulldown(m, off, sizeof(*ipcomp), NULL);
cf7d32b8	108	if (!md) {
9bccf70c A	109	m = NULL; /already freed/
	110	ipseclog((LOG_DEBUG, "IPv4 IPComp input: assumption failed "
	111	"(pulldown failure)\n"));
2d21ac55	112	IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
9bccf70c A	113	goto fail;
	114	}
	115	ipcomp = mtod(md, struct ipcomp *);
316670eb A	116
	117	/* Expect 32-bit aligned data pointer on strict-align platforms */
	118	MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);
	119
1c79356b	120	ip = mtod(m, struct ip *);
1c79356b A	121	nxt = ipcomp->comp_nxt;
	122	#ifdef _IP_VHL
	123	hlen = IP_VHL_HL(ip->ip_vhl) << 2;
	124	#else
	125	hlen = ip->ip_hl << 2;
	126	#endif
	127
	128	cpi = ntohs(ipcomp->comp_cpi);
	129
	130	if (cpi >= IPCOMP_CPI_NEGOTIATE_MIN) {
	131	sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src,
	132	(caddr_t)&ip->ip_dst, IPPROTO_IPCOMP, htonl(cpi));
	133	if (sav != NULL
	134	&& (sav->state == SADB_SASTATE_MATURE
	135	\|\| sav->state == SADB_SASTATE_DYING)) {
	136	cpi = sav->alg_enc; /XXX/
	137	/* other parameters to look at? */
	138	}
	139	}
9bccf70c	140	algo = ipcomp_algorithm_lookup(cpi);
1c79356b A	141	if (!algo) {
	142	ipseclog((LOG_WARNING, "IPv4 IPComp input: unknown cpi %u\n",
	143	cpi));
2d21ac55	144	IPSEC_STAT_INCREMENT(ipsecstat.in_nosa);
1c79356b A	145	goto fail;
	146	}
	147
	148	/* chop ipcomp header */
	149	ipcomp = NULL;
9bccf70c A	150	md->m_data += sizeof(struct ipcomp);
9bccf70c A	151	md->m_len -= sizeof(struct ipcomp);
1c79356b A	152	m->m_pkthdr.len -= sizeof(struct ipcomp);
	153	#ifdef IPLEN_FLIPPED
	154	ip->ip_len -= sizeof(struct ipcomp);
	155	#else
	156	ip->ip_len = htons(ntohs(ip->ip_len) - sizeof(struct ipcomp));
	157	#endif
	158
	159	olen = m->m_pkthdr.len;
	160	newlen = m->m_pkthdr.len - off;
	161	error = (*algo->decompress)(m, m->m_next, &newlen);
	162	if (error != 0) {
2d21ac55 A	163	if (error == EINVAL) {
	164	IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
	165	} else if (error == ENOBUFS)
	166	IPSEC_STAT_INCREMENT(ipsecstat.in_nomem);
1c79356b A	167	m = NULL;
	168	goto fail;
	169	}
2d21ac55	170	IPSEC_STAT_INCREMENT(ipsecstat.in_comphist[cpi]);
1c79356b A	171
	172	/*
	173	* returning decompressed packet onto icmp is meaningless.
	174	* mark it decrypted to prevent icmp from attaching original packet.
	175	*/
	176	m->m_flags \|= M_DECRYPTED;
	177
	178	m->m_pkthdr.len = off + newlen;
	179	ip = mtod(m, struct ip *);
	180	{
	181	size_t len;
	182	#ifdef IPLEN_FLIPPED
	183	len = ip->ip_len;
	184	#else
	185	len = ntohs(ip->ip_len);
	186	#endif
	187	/*
	188	* be careful about underflow. also, do not assign exact value
	189	* as ip_len is manipulated differently on *BSDs.
	190	*/
	191	len += m->m_pkthdr.len;
	192	len -= olen;
	193	if (len & ~0xffff) {
	194	/* packet too big after decompress */
2d21ac55	195	IPSEC_STAT_INCREMENT(ipsecstat.in_inval);
1c79356b A	196	goto fail;
	197	}
	198	#ifdef IPLEN_FLIPPED
	199	ip->ip_len = len & 0xffff;
	200	#else
	201	ip->ip_len = htons(len & 0xffff);
	202	#endif
	203	ip->ip_p = nxt;
	204	}
	205
	206	if (sav) {
	207	key_sa_recordxfer(sav, m);
9bccf70c	208	if (ipsec_addhist(m, IPPROTO_IPCOMP, (u_int32_t)cpi) != 0) {
2d21ac55	209	IPSEC_STAT_INCREMENT(ipsecstat.in_nomem);
9bccf70c A	210	goto fail;
9bccf70c A	211	}
2d21ac55	212	key_freesav(sav, KEY_SADB_UNLOCKED);
1c79356b A	213	sav = NULL;
	214	}
	215
9bccf70c A	216	if (nxt != IPPROTO_DONE) {
	217	if ((ip_protox[nxt]->pr_flags & PR_LASTHDR) != 0 &&
	218	ipsec4_in_reject(m, NULL)) {
2d21ac55	219	IPSEC_STAT_INCREMENT(ipsecstat.in_polvio);
9bccf70c A	220	goto fail;
9bccf70c A	221	}
6d2010ae A	222
	223	DTRACE_IP6(receive, struct mbuf , m, struct inpcb , NULL,
	224	struct ip , ip, struct ifnet , m->m_pkthdr.rcvif,
	225	struct ip , ip, struct ip6_hdr , NULL);
	226
91447636	227	ip_proto_dispatch_in(m, off, nxt, 0);
9bccf70c	228	} else
1c79356b A	229	m_freem(m);
	230	m = NULL;
	231
2d21ac55	232	IPSEC_STAT_INCREMENT(ipsecstat.in_success);
1c79356b A	233	return;
	234
	235	fail:
	236	if (sav)
2d21ac55	237	key_freesav(sav, KEY_SADB_UNLOCKED);
91447636	238
1c79356b A	239	if (m)
	240	m_freem(m);
	241	return;
	242	}
1c79356b A	243
	244	#if INET6
	245	int
6d2010ae	246	ipcomp6_input(struct mbuf *mp, int offp, int proto)
1c79356b	247	{
6d2010ae	248	#pragma unused(proto)
1c79356b A	249	struct mbuf m, md;
	250	int off;
	251	struct ip6_hdr *ip6;
1c79356b	252	struct ipcomp *ipcomp;
9bccf70c	253	const struct ipcomp_algorithm *algo;
1c79356b A	254	u_int16_t cpi; /* host order */
	255	u_int16_t nxt;
	256	int error;
	257	size_t newlen;
	258	struct secasvar *sav = NULL;
9bccf70c	259	char *prvnxtp;
1c79356b A	260
	261	m = *mp;
	262	off = *offp;
	263
9bccf70c	264	md = m_pulldown(m, off, sizeof(*ipcomp), NULL);
cf7d32b8	265	if (!md) {
9bccf70c A	266	m = NULL; /already freed/
	267	ipseclog((LOG_DEBUG, "IPv6 IPComp input: assumption failed "
	268	"(pulldown failure)\n"));
2d21ac55	269	IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
1c79356b A	270	goto fail;
1c79356b A	271	}
9bccf70c	272	ipcomp = mtod(md, struct ipcomp *);
316670eb A	273
	274	/* Expect 32-bit aligned data pointer on strict-align platforms */
	275	MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);
	276
1c79356b	277	ip6 = mtod(m, struct ip6_hdr *);
1c79356b	278	nxt = ipcomp->comp_nxt;
9bccf70c	279
1c79356b A	280	cpi = ntohs(ipcomp->comp_cpi);
	281
	282	if (cpi >= IPCOMP_CPI_NEGOTIATE_MIN) {
	283	sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src,
	284	(caddr_t)&ip6->ip6_dst, IPPROTO_IPCOMP, htonl(cpi));
	285	if (sav != NULL
	286	&& (sav->state == SADB_SASTATE_MATURE
	287	\|\| sav->state == SADB_SASTATE_DYING)) {
	288	cpi = sav->alg_enc; /XXX/
	289	/* other parameters to look at? */
	290	}
	291	}
9bccf70c	292	algo = ipcomp_algorithm_lookup(cpi);
1c79356b A	293	if (!algo) {
	294	ipseclog((LOG_WARNING, "IPv6 IPComp input: unknown cpi %u; "
	295	"dropping the packet for simplicity\n", cpi));
2d21ac55	296	IPSEC_STAT_INCREMENT(ipsec6stat.in_nosa);
1c79356b A	297	goto fail;
	298	}
	299
9bccf70c A	300	/* chop ipcomp header */
	301	ipcomp = NULL;
	302	md->m_data += sizeof(struct ipcomp);
	303	md->m_len -= sizeof(struct ipcomp);
	304	m->m_pkthdr.len -= sizeof(struct ipcomp);
	305
	306	newlen = m->m_pkthdr.len - off;
1c79356b A	307	error = (*algo->decompress)(m, md, &newlen);
1c79356b A	308	if (error != 0) {
2d21ac55 A	309	if (error == EINVAL) {
	310	IPSEC_STAT_INCREMENT(ipsec6stat.in_inval);
	311	} else if (error == ENOBUFS)
	312	IPSEC_STAT_INCREMENT(ipsec6stat.in_nomem);
1c79356b A	313	m = NULL;
	314	goto fail;
	315	}
2d21ac55	316	IPSEC_STAT_INCREMENT(ipsec6stat.in_comphist[cpi]);
9bccf70c	317	m->m_pkthdr.len = off + newlen;
1c79356b A	318
	319	/*
	320	* returning decompressed packet onto icmp is meaningless.
	321	* mark it decrypted to prevent icmp from attaching original packet.
	322	*/
	323	m->m_flags \|= M_DECRYPTED;
	324
9bccf70c	325	/* update next header field */
1c79356b A	326	prvnxtp = ip6_get_prevhdr(m, off);
1c79356b A	327	*prvnxtp = nxt;
1c79356b	328
9bccf70c A	329	/*
	330	* no need to adjust payload length, as all the IPv6 protocols
	331	* look at m->m_pkthdr.len
	332	*/
1c79356b A	333
	334	if (sav) {
	335	key_sa_recordxfer(sav, m);
9bccf70c	336	if (ipsec_addhist(m, IPPROTO_IPCOMP, (u_int32_t)cpi) != 0) {
2d21ac55	337	IPSEC_STAT_INCREMENT(ipsec6stat.in_nomem);
9bccf70c A	338	goto fail;
9bccf70c A	339	}
2d21ac55	340	key_freesav(sav, KEY_SADB_UNLOCKED);
1c79356b A	341	sav = NULL;
	342	}
	343	*offp = off;
	344	*mp = m;
2d21ac55	345	IPSEC_STAT_INCREMENT(ipsec6stat.in_success);
1c79356b A	346	return nxt;
	347
	348	fail:
	349	if (m)
	350	m_freem(m);
	351	if (sav)
2d21ac55	352	key_freesav(sav, KEY_SADB_UNLOCKED);
1c79356b A	353	return IPPROTO_DONE;
	354	}
	355	#endif /* INET6 */