[apple/xnu.git] / bsd / netinet6 / route6.c

/*	$FreeBSD: src/sys/netinet6/route6.c,v 1.1.2.3 2001/07/03 11:01:55 ume Exp $	*/
/*	$KAME: route6.c,v 1.24 2001/03/14 03:07:05 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.
 */

#include <sys/param.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/queue.h>

#include <net/if.h>

#include <netinet/in.h>
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>

#include <netinet/icmp6.h>

static int ip6_rthdr0 __P((struct mbuf *, struct ip6_hdr *,
    struct ip6_rthdr0 *));

int
route6_input(mp, offp)
	struct mbuf **mp;
	int *offp;
{
	struct ip6_hdr *ip6;
	struct mbuf *m = *mp;
	struct ip6_rthdr *rh;
	int off = *offp, rhlen;
	struct mbuf *n;

	n = ip6_findaux(m);
	if (n) {
		struct ip6aux *ip6a = mtod(n, struct ip6aux *);
		/* XXX reject home-address option before rthdr */
		if (ip6a->ip6a_flags & IP6A_SWAP) {
			ip6stat.ip6s_badoptions++;
			m_freem(m);
			return IPPROTO_DONE;
		}
	}

#ifndef PULLDOWN_TEST
	IP6_EXTHDR_CHECK(m, off, sizeof(*rh), IPPROTO_DONE);
	ip6 = mtod(m, struct ip6_hdr *);
	rh = (struct ip6_rthdr *)((caddr_t)ip6 + off);
#else
	ip6 = mtod(m, struct ip6_hdr *);
	IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh));
	if (rh == NULL) {
		ip6stat.ip6s_tooshort++;
		return IPPROTO_DONE;
	}
#endif

	switch (rh->ip6r_type) {
	case IPV6_RTHDR_TYPE_0:
		rhlen = (rh->ip6r_len + 1) << 3;
#ifndef PULLDOWN_TEST
		/*
		 * note on option length:
		 * due to IP6_EXTHDR_CHECK assumption, we cannot handle
		 * very big routing header (max rhlen == 2048).
		 */
		IP6_EXTHDR_CHECK(m, off, rhlen, IPPROTO_DONE);
#else
		/*
		 * note on option length:
		 * maximum rhlen: 2048
		 * max mbuf m_pulldown can handle: MCLBYTES == usually 2048
		 * so, here we are assuming that m_pulldown can handle
		 * rhlen == 2048 case.  this may not be a good thing to
		 * assume - we may want to avoid pulling it up altogether.
		 */
		IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen);
		if (rh == NULL) {
			ip6stat.ip6s_tooshort++;
			return IPPROTO_DONE;
		}
#endif
		if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh))
			return(IPPROTO_DONE);
		break;
	default:
		/* unknown routing type */
		if (rh->ip6r_segleft == 0) {
			rhlen = (rh->ip6r_len + 1) << 3;
			break;	/* Final dst. Just ignore the header. */
		}
		ip6stat.ip6s_badoptions++;
		icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
			    (caddr_t)&rh->ip6r_type - (caddr_t)ip6);
		return(IPPROTO_DONE);
	}

	*offp += rhlen;
	return(rh->ip6r_nxt);
}

/*
 * Type0 routing header processing
 *
 * RFC2292 backward compatibility warning: no support for strict/loose bitmap,
 * as it was dropped between RFC1883 and RFC2460.
 */
static int
ip6_rthdr0(m, ip6, rh0)
	struct mbuf *m;
	struct ip6_hdr *ip6;
	struct ip6_rthdr0 *rh0;
{
	int addrs, index;
	struct in6_addr *nextaddr, tmpaddr;

	if (rh0->ip6r0_segleft == 0)
		return(0);

	if (rh0->ip6r0_len % 2
#if COMPAT_RFC1883
	    || rh0->ip6r0_len > 46
#endif
		) {
		/*
		 * Type 0 routing header can't contain more than 23 addresses.
		 * RFC 2462: this limitation was removed since stict/loose
		 * bitmap field was deleted.
		 */
		ip6stat.ip6s_badoptions++;
		icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
			    (caddr_t)&rh0->ip6r0_len - (caddr_t)ip6);
		return(-1);
	}

	if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) {
		ip6stat.ip6s_badoptions++;
		icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
			    (caddr_t)&rh0->ip6r0_segleft - (caddr_t)ip6);
		return(-1);
	}

	index = addrs - rh0->ip6r0_segleft;
	rh0->ip6r0_segleft--;
	/* note that ip6r0_addr does not exist in RFC2292bis */
	nextaddr = rh0->ip6r0_addr + index;

	/*
	 * reject invalid addresses.  be proactive about malicious use of
	 * IPv4 mapped/compat address.
	 * XXX need more checks?
	 */
	if (IN6_IS_ADDR_MULTICAST(nextaddr) ||
	    IN6_IS_ADDR_UNSPECIFIED(nextaddr) ||
	    IN6_IS_ADDR_V4MAPPED(nextaddr) ||
	    IN6_IS_ADDR_V4COMPAT(nextaddr)) {
		ip6stat.ip6s_badoptions++;
		m_freem(m);
		return(-1);
	}
	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
	    IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) ||
	    IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) ||
	    IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
		ip6stat.ip6s_badoptions++;
		m_freem(m);
		return(-1);
	}

	/*
	 * Swap the IPv6 destination address and nextaddr. Forward the packet.
	 */
	tmpaddr = *nextaddr;
	*nextaddr = ip6->ip6_dst;
	if (IN6_IS_ADDR_LINKLOCAL(nextaddr))
		nextaddr->s6_addr16[1] = 0;
	ip6->ip6_dst = tmpaddr;
	if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
		ip6->ip6_dst.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index);

#if COMPAT_RFC1883
	if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8))))
		ip6_forward(m, IPV6_SRCRT_NEIGHBOR);
	else
		ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR);
#else
	ip6_forward(m, 1);
#endif

	return(-1);			/* m would be freed in ip6_forward() */
}
Commit	Line	Data
9bccf70c A	1	/* $FreeBSD: src/sys/netinet6/route6.c,v 1.1.2.3 2001/07/03 11:01:55 ume Exp $ */
9bccf70c A	2	/* $KAME: route6.c,v 1.24 2001/03/14 03:07:05 itojun Exp $ */
1c79356b A	3
	4	/*
	5	* Copyright (C) 1995, 1996, 1997, and 1998 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	#include <sys/param.h>
	34	#include <sys/mbuf.h>
	35	#include <sys/socket.h>
9bccf70c	36	#include <sys/queue.h>
1c79356b A	37
	38	#include <net/if.h>
	39
	40	#include <netinet/in.h>
	41	#include <netinet6/in6_var.h>
	42	#include <netinet/ip6.h>
	43	#include <netinet6/ip6_var.h>
	44
	45	#include <netinet/icmp6.h>
	46
1c79356b A	47	static int ip6_rthdr0 __P((struct mbuf , struct ip6_hdr ,
	48	struct ip6_rthdr0 *));
	49
1c79356b	50	int
55e303ae	51	route6_input(mp, offp)
1c79356b	52	struct mbuf **mp;
55e303ae	53	int *offp;
1c79356b	54	{
9bccf70c A	55	struct ip6_hdr *ip6;
	56	struct mbuf m = mp;
	57	struct ip6_rthdr *rh;
1c79356b	58	int off = *offp, rhlen;
9bccf70c A	59	struct mbuf *n;
	60
	61	n = ip6_findaux(m);
	62	if (n) {
	63	struct ip6aux ip6a = mtod(n, struct ip6aux );
	64	/* XXX reject home-address option before rthdr */
	65	if (ip6a->ip6a_flags & IP6A_SWAP) {
	66	ip6stat.ip6s_badoptions++;
	67	m_freem(m);
	68	return IPPROTO_DONE;
	69	}
	70	}
1c79356b A	71
	72	#ifndef PULLDOWN_TEST
	73	IP6_EXTHDR_CHECK(m, off, sizeof(*rh), IPPROTO_DONE);
	74	ip6 = mtod(m, struct ip6_hdr *);
	75	rh = (struct ip6_rthdr *)((caddr_t)ip6 + off);
	76	#else
	77	ip6 = mtod(m, struct ip6_hdr *);
	78	IP6_EXTHDR_GET(rh, struct ip6_rthdr , m, off, sizeof(rh));
	79	if (rh == NULL) {
	80	ip6stat.ip6s_tooshort++;
	81	return IPPROTO_DONE;
	82	}
	83	#endif
	84
9bccf70c A	85	switch (rh->ip6r_type) {
	86	case IPV6_RTHDR_TYPE_0:
	87	rhlen = (rh->ip6r_len + 1) << 3;
1c79356b	88	#ifndef PULLDOWN_TEST
9bccf70c A	89	/*
	90	* note on option length:
	91	* due to IP6_EXTHDR_CHECK assumption, we cannot handle
	92	* very big routing header (max rhlen == 2048).
	93	*/
	94	IP6_EXTHDR_CHECK(m, off, rhlen, IPPROTO_DONE);
1c79356b	95	#else
9bccf70c A	96	/*
	97	* note on option length:
	98	* maximum rhlen: 2048
	99	* max mbuf m_pulldown can handle: MCLBYTES == usually 2048
	100	* so, here we are assuming that m_pulldown can handle
	101	* rhlen == 2048 case. this may not be a good thing to
	102	* assume - we may want to avoid pulling it up altogether.
	103	*/
	104	IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen);
	105	if (rh == NULL) {
1c79356b A	106	ip6stat.ip6s_tooshort++;
1c79356b A	107	return IPPROTO_DONE;
9bccf70c	108	}
1c79356b	109	#endif
9bccf70c A	110	if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh))
	111	return(IPPROTO_DONE);
	112	break;
	113	default:
	114	/* unknown routing type */
	115	if (rh->ip6r_segleft == 0) {
	116	rhlen = (rh->ip6r_len + 1) << 3;
	117	break; /* Final dst. Just ignore the header. */
	118	}
	119	ip6stat.ip6s_badoptions++;
	120	icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
	121	(caddr_t)&rh->ip6r_type - (caddr_t)ip6);
	122	return(IPPROTO_DONE);
	123	}
	124
1c79356b A	125	*offp += rhlen;
	126	return(rh->ip6r_nxt);
	127	}
	128
	129	/*
	130	* Type0 routing header processing
9bccf70c A	131	*
	132	* RFC2292 backward compatibility warning: no support for strict/loose bitmap,
	133	* as it was dropped between RFC1883 and RFC2460.
1c79356b A	134	*/
	135	static int
	136	ip6_rthdr0(m, ip6, rh0)
	137	struct mbuf *m;
	138	struct ip6_hdr *ip6;
	139	struct ip6_rthdr0 *rh0;
	140	{
	141	int addrs, index;
	142	struct in6_addr *nextaddr, tmpaddr;
	143
	144	if (rh0->ip6r0_segleft == 0)
	145	return(0);
	146
	147	if (rh0->ip6r0_len % 2
	148	#if COMPAT_RFC1883
	149	\|\| rh0->ip6r0_len > 46
	150	#endif
	151	) {
	152	/*
	153	* Type 0 routing header can't contain more than 23 addresses.
	154	* RFC 2462: this limitation was removed since stict/loose
	155	* bitmap field was deleted.
	156	*/
	157	ip6stat.ip6s_badoptions++;
	158	icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
	159	(caddr_t)&rh0->ip6r0_len - (caddr_t)ip6);
	160	return(-1);
	161	}
	162
	163	if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) {
	164	ip6stat.ip6s_badoptions++;
	165	icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
	166	(caddr_t)&rh0->ip6r0_segleft - (caddr_t)ip6);
	167	return(-1);
	168	}
	169
	170	index = addrs - rh0->ip6r0_segleft;
	171	rh0->ip6r0_segleft--;
9bccf70c A	172	/* note that ip6r0_addr does not exist in RFC2292bis */
9bccf70c A	173	nextaddr = rh0->ip6r0_addr + index;
1c79356b A	174
	175	/*
	176	* reject invalid addresses. be proactive about malicious use of
	177	* IPv4 mapped/compat address.
	178	* XXX need more checks?
	179	*/
	180	if (IN6_IS_ADDR_MULTICAST(nextaddr) \|\|
	181	IN6_IS_ADDR_UNSPECIFIED(nextaddr) \|\|
	182	IN6_IS_ADDR_V4MAPPED(nextaddr) \|\|
	183	IN6_IS_ADDR_V4COMPAT(nextaddr)) {
	184	ip6stat.ip6s_badoptions++;
	185	m_freem(m);
	186	return(-1);
	187	}
	188	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) \|\|
	189	IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) \|\|
	190	IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) \|\|
9bccf70c	191	IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
1c79356b A	192	ip6stat.ip6s_badoptions++;
	193	m_freem(m);
	194	return(-1);
	195	}
	196
	197	/*
	198	* Swap the IPv6 destination address and nextaddr. Forward the packet.
	199	*/
	200	tmpaddr = *nextaddr;
	201	*nextaddr = ip6->ip6_dst;
	202	if (IN6_IS_ADDR_LINKLOCAL(nextaddr))
	203	nextaddr->s6_addr16[1] = 0;
	204	ip6->ip6_dst = tmpaddr;
	205	if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
	206	ip6->ip6_dst.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index);
	207
	208	#if COMPAT_RFC1883
	209	if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8))))
	210	ip6_forward(m, IPV6_SRCRT_NEIGHBOR);
	211	else
	212	ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR);
	213	#else
	214	ip6_forward(m, 1);
	215	#endif
	216
	217	return(-1); /* m would be freed in ip6_forward() */
	218	}