[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 <string.h>

#include <net/if.h>
#include <net/route.h>

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

#include <netinet/icmp6.h>

#if IP6_RTHDR0_ALLOWED
static int ip6_rthdr0(struct mbuf *, struct ip6_hdr *,
    struct ip6_rthdr0 *);
#endif /* IP6_RTHDR0_ALLOWED */

int
route6_input(struct mbuf **mp, int *offp)
{
	struct ip6_hdr *ip6;
	struct mbuf *m = *mp;
	struct ip6_rthdr *rh;
	int off = *offp, rhlen;
	struct ip6aux *ip6a;

	ip6a = ip6_findaux(m);
	if (ip6a) {
		/* 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), return 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) {
#if IP6_RTHDR0_ALLOWED
	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, return 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;
#endif /* IP6_RTHDR0_ALLOWED */
	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);
}

#if IP6_RTHDR0_ALLOWED
/*
 * 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;
	struct route_in6 ip6forward_rt;

	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);

	/*
	 * Don't use the globally cached route to forward packet having
	 * Type 0 routing header(s); instead, do an explicit lookup using
	 * a local route entry variable, in case the next address in the
	 * packet is bogus (which would otherwise unnecessarily invalidate
	 * the globally cached route).
	 */
	bzero(&ip6forward_rt, sizeof (ip6forward_rt));

#if COMPAT_RFC1883
	if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8))))
		ip6_forward(m, &ip6forward_rt, IPV6_SRCRT_NEIGHBOR, 0);
	else
		ip6_forward(m, &ip6forward_rt, IPV6_SRCRT_NOTNEIGHBOR, 0);
#else
	ip6_forward(m, &ip6forward_rt, 1, 0);
#endif

	/* Release reference to the looked up route */
	if (ip6forward_rt.ro_rt != NULL) {
		rtfree(ip6forward_rt.ro_rt);
		ip6forward_rt.ro_rt = NULL;
	}

	return(-1);			/* m would be freed in ip6_forward() */
}
#endif /* IP6_RTHDR0_ALLOWED */
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>
2d21ac55	37	#include <string.h>
1c79356b A	38
1c79356b A	39	#include <net/if.h>
2d21ac55	40	#include <net/route.h>
1c79356b A	41
	42	#include <netinet/in.h>
	43	#include <netinet6/in6_var.h>
	44	#include <netinet/ip6.h>
	45	#include <netinet6/ip6_var.h>
	46
	47	#include <netinet/icmp6.h>
	48
21362eb3	49	#if IP6_RTHDR0_ALLOWED
91447636 A	50	static int ip6_rthdr0(struct mbuf , struct ip6_hdr ,
91447636 A	51	struct ip6_rthdr0 *);
21362eb3	52	#endif /* IP6_RTHDR0_ALLOWED */
1c79356b	53
1c79356b	54	int
2d21ac55	55	route6_input(struct mbuf *mp, int offp)
1c79356b	56	{
9bccf70c A	57	struct ip6_hdr *ip6;
	58	struct mbuf m = mp;
	59	struct ip6_rthdr *rh;
1c79356b	60	int off = *offp, rhlen;
2d21ac55	61	struct ip6aux *ip6a;
9bccf70c	62
2d21ac55 A	63	ip6a = ip6_findaux(m);
2d21ac55 A	64	if (ip6a) {
9bccf70c A	65	/* XXX reject home-address option before rthdr */
	66	if (ip6a->ip6a_flags & IP6A_SWAP) {
	67	ip6stat.ip6s_badoptions++;
	68	m_freem(m);
	69	return IPPROTO_DONE;
	70	}
	71	}
1c79356b A	72
1c79356b A	73	#ifndef PULLDOWN_TEST
91447636	74	IP6_EXTHDR_CHECK(m, off, sizeof(*rh), return IPPROTO_DONE);
1c79356b A	75	ip6 = mtod(m, struct ip6_hdr *);
	76	rh = (struct ip6_rthdr *)((caddr_t)ip6 + off);
	77	#else
	78	ip6 = mtod(m, struct ip6_hdr *);
	79	IP6_EXTHDR_GET(rh, struct ip6_rthdr , m, off, sizeof(rh));
	80	if (rh == NULL) {
	81	ip6stat.ip6s_tooshort++;
	82	return IPPROTO_DONE;
	83	}
	84	#endif
	85
9bccf70c	86	switch (rh->ip6r_type) {
21362eb3	87	#if IP6_RTHDR0_ALLOWED
9bccf70c A	88	case IPV6_RTHDR_TYPE_0:
9bccf70c A	89	rhlen = (rh->ip6r_len + 1) << 3;
1c79356b	90	#ifndef PULLDOWN_TEST
9bccf70c A	91	/*
	92	* note on option length:
	93	* due to IP6_EXTHDR_CHECK assumption, we cannot handle
	94	* very big routing header (max rhlen == 2048).
	95	*/
91447636	96	IP6_EXTHDR_CHECK(m, off, rhlen, return IPPROTO_DONE);
1c79356b	97	#else
9bccf70c A	98	/*
	99	* note on option length:
	100	* maximum rhlen: 2048
	101	* max mbuf m_pulldown can handle: MCLBYTES == usually 2048
	102	* so, here we are assuming that m_pulldown can handle
	103	* rhlen == 2048 case. this may not be a good thing to
	104	* assume - we may want to avoid pulling it up altogether.
	105	*/
	106	IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen);
	107	if (rh == NULL) {
1c79356b A	108	ip6stat.ip6s_tooshort++;
1c79356b A	109	return IPPROTO_DONE;
9bccf70c	110	}
1c79356b	111	#endif
9bccf70c A	112	if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh))
	113	return(IPPROTO_DONE);
	114	break;
21362eb3	115	#endif /* IP6_RTHDR0_ALLOWED */
9bccf70c A	116	default:
	117	/* unknown routing type */
	118	if (rh->ip6r_segleft == 0) {
	119	rhlen = (rh->ip6r_len + 1) << 3;
	120	break; /* Final dst. Just ignore the header. */
	121	}
	122	ip6stat.ip6s_badoptions++;
	123	icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
	124	(caddr_t)&rh->ip6r_type - (caddr_t)ip6);
	125	return(IPPROTO_DONE);
	126	}
	127
1c79356b A	128	*offp += rhlen;
	129	return(rh->ip6r_nxt);
	130	}
	131
21362eb3	132	#if IP6_RTHDR0_ALLOWED
1c79356b A	133	/*
1c79356b A	134	* Type0 routing header processing
9bccf70c A	135	*
	136	* RFC2292 backward compatibility warning: no support for strict/loose bitmap,
	137	* as it was dropped between RFC1883 and RFC2460.
1c79356b A	138	*/
	139	static int
	140	ip6_rthdr0(m, ip6, rh0)
	141	struct mbuf *m;
	142	struct ip6_hdr *ip6;
	143	struct ip6_rthdr0 *rh0;
	144	{
	145	int addrs, index;
	146	struct in6_addr *nextaddr, tmpaddr;
2d21ac55	147	struct route_in6 ip6forward_rt;
1c79356b A	148
	149	if (rh0->ip6r0_segleft == 0)
	150	return(0);
	151
	152	if (rh0->ip6r0_len % 2
	153	#if COMPAT_RFC1883
	154	\|\| rh0->ip6r0_len > 46
	155	#endif
	156	) {
	157	/*
	158	* Type 0 routing header can't contain more than 23 addresses.
	159	* RFC 2462: this limitation was removed since stict/loose
	160	* bitmap field was deleted.
	161	*/
	162	ip6stat.ip6s_badoptions++;
	163	icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
	164	(caddr_t)&rh0->ip6r0_len - (caddr_t)ip6);
	165	return(-1);
	166	}
	167
	168	if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) {
	169	ip6stat.ip6s_badoptions++;
	170	icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
	171	(caddr_t)&rh0->ip6r0_segleft - (caddr_t)ip6);
	172	return(-1);
	173	}
	174
	175	index = addrs - rh0->ip6r0_segleft;
	176	rh0->ip6r0_segleft--;
9bccf70c A	177	/* note that ip6r0_addr does not exist in RFC2292bis */
9bccf70c A	178	nextaddr = rh0->ip6r0_addr + index;
1c79356b A	179
	180	/*
	181	* reject invalid addresses. be proactive about malicious use of
	182	* IPv4 mapped/compat address.
	183	* XXX need more checks?
	184	*/
	185	if (IN6_IS_ADDR_MULTICAST(nextaddr) \|\|
	186	IN6_IS_ADDR_UNSPECIFIED(nextaddr) \|\|
	187	IN6_IS_ADDR_V4MAPPED(nextaddr) \|\|
	188	IN6_IS_ADDR_V4COMPAT(nextaddr)) {
	189	ip6stat.ip6s_badoptions++;
	190	m_freem(m);
	191	return(-1);
	192	}
	193	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) \|\|
	194	IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) \|\|
	195	IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) \|\|
9bccf70c	196	IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
1c79356b A	197	ip6stat.ip6s_badoptions++;
	198	m_freem(m);
	199	return(-1);
	200	}
	201
	202	/*
	203	* Swap the IPv6 destination address and nextaddr. Forward the packet.
	204	*/
	205	tmpaddr = *nextaddr;
	206	*nextaddr = ip6->ip6_dst;
	207	if (IN6_IS_ADDR_LINKLOCAL(nextaddr))
	208	nextaddr->s6_addr16[1] = 0;
	209	ip6->ip6_dst = tmpaddr;
	210	if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
	211	ip6->ip6_dst.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index);
	212
2d21ac55 A	213	/*
	214	* Don't use the globally cached route to forward packet having
	215	* Type 0 routing header(s); instead, do an explicit lookup using
	216	* a local route entry variable, in case the next address in the
	217	* packet is bogus (which would otherwise unnecessarily invalidate
	218	* the globally cached route).
	219	*/
	220	bzero(&ip6forward_rt, sizeof (ip6forward_rt));
	221
1c79356b A	222	#if COMPAT_RFC1883
1c79356b A	223	if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8))))
2d21ac55	224	ip6_forward(m, &ip6forward_rt, IPV6_SRCRT_NEIGHBOR, 0);
1c79356b	225	else
2d21ac55	226	ip6_forward(m, &ip6forward_rt, IPV6_SRCRT_NOTNEIGHBOR, 0);
1c79356b	227	#else
2d21ac55	228	ip6_forward(m, &ip6forward_rt, 1, 0);
1c79356b A	229	#endif
1c79356b A	230
2d21ac55 A	231	/* Release reference to the looked up route */
	232	if (ip6forward_rt.ro_rt != NULL) {
	233	rtfree(ip6forward_rt.ro_rt);
	234	ip6forward_rt.ro_rt = NULL;
	235	}
	236
1c79356b A	237	return(-1); /* m would be freed in ip6_forward() */
1c79356b A	238	}
21362eb3	239	#endif /* IP6_RTHDR0_ALLOWED */
2d21ac55	240