xref: /freebsd/sys/netinet6/ip6_forward.c (revision 1d54aa3ba94f4d9883b0746ce45123d5b5be773b)
1686cdd19SJun-ichiro itojun Hagino /*	$FreeBSD$	*/
233841545SHajimu UMEMOTO /*	$KAME: ip6_forward.c,v 1.69 2001/05/17 03:48:30 itojun Exp $	*/
3686cdd19SJun-ichiro itojun Hagino 
4caf43b02SWarner Losh /*-
582cd038dSYoshinobu Inoue  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
682cd038dSYoshinobu Inoue  * All rights reserved.
782cd038dSYoshinobu Inoue  *
882cd038dSYoshinobu Inoue  * Redistribution and use in source and binary forms, with or without
982cd038dSYoshinobu Inoue  * modification, are permitted provided that the following conditions
1082cd038dSYoshinobu Inoue  * are met:
1182cd038dSYoshinobu Inoue  * 1. Redistributions of source code must retain the above copyright
1282cd038dSYoshinobu Inoue  *    notice, this list of conditions and the following disclaimer.
1382cd038dSYoshinobu Inoue  * 2. Redistributions in binary form must reproduce the above copyright
1482cd038dSYoshinobu Inoue  *    notice, this list of conditions and the following disclaimer in the
1582cd038dSYoshinobu Inoue  *    documentation and/or other materials provided with the distribution.
1682cd038dSYoshinobu Inoue  * 3. Neither the name of the project nor the names of its contributors
1782cd038dSYoshinobu Inoue  *    may be used to endorse or promote products derived from this software
1882cd038dSYoshinobu Inoue  *    without specific prior written permission.
1982cd038dSYoshinobu Inoue  *
2082cd038dSYoshinobu Inoue  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
2182cd038dSYoshinobu Inoue  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
2282cd038dSYoshinobu Inoue  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
2382cd038dSYoshinobu Inoue  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
2482cd038dSYoshinobu Inoue  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
2582cd038dSYoshinobu Inoue  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
2682cd038dSYoshinobu Inoue  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
2782cd038dSYoshinobu Inoue  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
2882cd038dSYoshinobu Inoue  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
2982cd038dSYoshinobu Inoue  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
3082cd038dSYoshinobu Inoue  * SUCH DAMAGE.
3182cd038dSYoshinobu Inoue  */
3282cd038dSYoshinobu Inoue 
33686cdd19SJun-ichiro itojun Hagino #include "opt_inet.h"
34686cdd19SJun-ichiro itojun Hagino #include "opt_inet6.h"
356a800098SYoshinobu Inoue #include "opt_ipsec.h"
36f8a8f9caSSUZUKI Shinsuke #include "opt_ipstealth.h"
3782cd038dSYoshinobu Inoue 
3882cd038dSYoshinobu Inoue #include <sys/param.h>
3982cd038dSYoshinobu Inoue #include <sys/systm.h>
4033841545SHajimu UMEMOTO #include <sys/malloc.h>
4182cd038dSYoshinobu Inoue #include <sys/mbuf.h>
4282cd038dSYoshinobu Inoue #include <sys/domain.h>
4382cd038dSYoshinobu Inoue #include <sys/protosw.h>
4482cd038dSYoshinobu Inoue #include <sys/socket.h>
4582cd038dSYoshinobu Inoue #include <sys/errno.h>
4682cd038dSYoshinobu Inoue #include <sys/time.h>
4733841545SHajimu UMEMOTO #include <sys/kernel.h>
4882cd038dSYoshinobu Inoue #include <sys/syslog.h>
4982cd038dSYoshinobu Inoue 
5082cd038dSYoshinobu Inoue #include <net/if.h>
5182cd038dSYoshinobu Inoue #include <net/route.h>
523a4d67f7SDarren Reed #include <net/pfil.h>
5382cd038dSYoshinobu Inoue 
5482cd038dSYoshinobu Inoue #include <netinet/in.h>
5582cd038dSYoshinobu Inoue #include <netinet/in_var.h>
5633841545SHajimu UMEMOTO #include <netinet/in_systm.h>
5733841545SHajimu UMEMOTO #include <netinet/ip.h>
58686cdd19SJun-ichiro itojun Hagino #include <netinet/ip_var.h>
5933841545SHajimu UMEMOTO #include <netinet6/in6_var.h>
60686cdd19SJun-ichiro itojun Hagino #include <netinet/ip6.h>
6182cd038dSYoshinobu Inoue #include <netinet6/ip6_var.h>
62a1f7e5f8SHajimu UMEMOTO #include <netinet6/scope6_var.h>
63686cdd19SJun-ichiro itojun Hagino #include <netinet/icmp6.h>
6482cd038dSYoshinobu Inoue #include <netinet6/nd6.h>
6582cd038dSYoshinobu Inoue 
6633841545SHajimu UMEMOTO #include <netinet/in_pcb.h>
6733841545SHajimu UMEMOTO 
68059e4684SJun-ichiro itojun Hagino #ifdef IPSEC
6982cd038dSYoshinobu Inoue #include <netinet6/ipsec.h>
7033841545SHajimu UMEMOTO #ifdef INET6
7126121655SJun-ichiro itojun Hagino #include <netinet6/ipsec6.h>
7233841545SHajimu UMEMOTO #endif
7382cd038dSYoshinobu Inoue #include <netkey/key.h>
74059e4684SJun-ichiro itojun Hagino #endif /* IPSEC */
7582cd038dSYoshinobu Inoue 
76b9234fafSSam Leffler #ifdef FAST_IPSEC
77b9234fafSSam Leffler #include <netipsec/ipsec.h>
78b9234fafSSam Leffler #include <netipsec/ipsec6.h>
79b9234fafSSam Leffler #include <netipsec/key.h>
80b9234fafSSam Leffler #define	IPSEC
81b9234fafSSam Leffler #endif /* FAST_IPSEC */
82b9234fafSSam Leffler 
833a4d67f7SDarren Reed #include <netinet6/ip6protosw.h>
843a4d67f7SDarren Reed 
8582cd038dSYoshinobu Inoue struct	route_in6 ip6_forward_rt;
8682cd038dSYoshinobu Inoue 
8782cd038dSYoshinobu Inoue /*
8882cd038dSYoshinobu Inoue  * Forward a packet.  If some error occurs return the sender
8982cd038dSYoshinobu Inoue  * an icmp packet.  Note we can't always generate a meaningful
9082cd038dSYoshinobu Inoue  * icmp message because icmp doesn't have a large enough repertoire
9182cd038dSYoshinobu Inoue  * of codes and types.
9282cd038dSYoshinobu Inoue  *
9382cd038dSYoshinobu Inoue  * If not forwarding, just drop the packet.  This could be confusing
9482cd038dSYoshinobu Inoue  * if ipforwarding was zero but some routing protocol was advancing
9582cd038dSYoshinobu Inoue  * us as a gateway to somewhere.  However, we must let the routing
9682cd038dSYoshinobu Inoue  * protocol deal with that.
9782cd038dSYoshinobu Inoue  *
9882cd038dSYoshinobu Inoue  */
9982cd038dSYoshinobu Inoue 
10082cd038dSYoshinobu Inoue void
10182cd038dSYoshinobu Inoue ip6_forward(m, srcrt)
10282cd038dSYoshinobu Inoue 	struct mbuf *m;
10382cd038dSYoshinobu Inoue 	int srcrt;
10482cd038dSYoshinobu Inoue {
10582cd038dSYoshinobu Inoue 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1060f9ade71SHajimu UMEMOTO 	struct sockaddr_in6 *dst = NULL;
1070f9ade71SHajimu UMEMOTO 	struct rtentry *rt = NULL;
10882cd038dSYoshinobu Inoue 	int error, type = 0, code = 0;
109686cdd19SJun-ichiro itojun Hagino 	struct mbuf *mcopy = NULL;
110686cdd19SJun-ichiro itojun Hagino 	struct ifnet *origifp;	/* maybe unnecessary */
111a1f7e5f8SHajimu UMEMOTO 	u_int32_t inzone, outzone;
112a1f7e5f8SHajimu UMEMOTO 	struct in6_addr src_in6, dst_in6;
113059e4684SJun-ichiro itojun Hagino #ifdef IPSEC
11482cd038dSYoshinobu Inoue 	struct secpolicy *sp = NULL;
1150f9ade71SHajimu UMEMOTO 	int ipsecrt = 0;
11682cd038dSYoshinobu Inoue #endif
1171d54aa3bSBjoern A. Zeeb 	char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
11882cd038dSYoshinobu Inoue 
1191b34a059SBjoern A. Zeeb 	GIANT_REQUIRED; /* XXX bz: ip6_forward_rt */
1201b34a059SBjoern A. Zeeb 
121059e4684SJun-ichiro itojun Hagino #ifdef IPSEC
12282cd038dSYoshinobu Inoue 	/*
12382cd038dSYoshinobu Inoue 	 * Check AH/ESP integrity.
12482cd038dSYoshinobu Inoue 	 */
12582cd038dSYoshinobu Inoue 	/*
12682cd038dSYoshinobu Inoue 	 * Don't increment ip6s_cantforward because this is the check
12782cd038dSYoshinobu Inoue 	 * before forwarding packet actually.
12882cd038dSYoshinobu Inoue 	 */
12982cd038dSYoshinobu Inoue 	if (ipsec6_in_reject(m, NULL)) {
130b9234fafSSam Leffler #if !defined(FAST_IPSEC)
13182cd038dSYoshinobu Inoue 		ipsec6stat.in_polvio++;
132b9234fafSSam Leffler #endif
13382cd038dSYoshinobu Inoue 		m_freem(m);
13482cd038dSYoshinobu Inoue 		return;
13582cd038dSYoshinobu Inoue 	}
136059e4684SJun-ichiro itojun Hagino #endif /* IPSEC */
13782cd038dSYoshinobu Inoue 
13833841545SHajimu UMEMOTO 	/*
13933841545SHajimu UMEMOTO 	 * Do not forward packets to multicast destination (should be handled
14033841545SHajimu UMEMOTO 	 * by ip6_mforward().
14133841545SHajimu UMEMOTO 	 * Do not forward packets with unspecified source.  It was discussed
1427efe5d92SHajimu UMEMOTO 	 * in July 2000, on the ipngwg mailing list.
14333841545SHajimu UMEMOTO 	 */
144686cdd19SJun-ichiro itojun Hagino 	if ((m->m_flags & (M_BCAST|M_MCAST)) != 0 ||
14533841545SHajimu UMEMOTO 	    IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
14633841545SHajimu UMEMOTO 	    IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) {
14782cd038dSYoshinobu Inoue 		ip6stat.ip6s_cantforward++;
14882cd038dSYoshinobu Inoue 		/* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */
14982cd038dSYoshinobu Inoue 		if (ip6_log_time + ip6_log_interval < time_second) {
15082cd038dSYoshinobu Inoue 			ip6_log_time = time_second;
15182cd038dSYoshinobu Inoue 			log(LOG_DEBUG,
15282cd038dSYoshinobu Inoue 			    "cannot forward "
15382cd038dSYoshinobu Inoue 			    "from %s to %s nxt %d received on %s\n",
1541d54aa3bSBjoern A. Zeeb 			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
1551d54aa3bSBjoern A. Zeeb 			    ip6_sprintf(ip6bufd, &ip6->ip6_dst),
15682cd038dSYoshinobu Inoue 			    ip6->ip6_nxt,
15782cd038dSYoshinobu Inoue 			    if_name(m->m_pkthdr.rcvif));
15882cd038dSYoshinobu Inoue 		}
15982cd038dSYoshinobu Inoue 		m_freem(m);
16082cd038dSYoshinobu Inoue 		return;
16182cd038dSYoshinobu Inoue 	}
16282cd038dSYoshinobu Inoue 
163f8a8f9caSSUZUKI Shinsuke #ifdef IPSTEALTH
164f8a8f9caSSUZUKI Shinsuke 	if (!ip6stealth) {
165f8a8f9caSSUZUKI Shinsuke #endif
16682cd038dSYoshinobu Inoue 	if (ip6->ip6_hlim <= IPV6_HLIMDEC) {
16782cd038dSYoshinobu Inoue 		/* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */
16882cd038dSYoshinobu Inoue 		icmp6_error(m, ICMP6_TIME_EXCEEDED,
16982cd038dSYoshinobu Inoue 				ICMP6_TIME_EXCEED_TRANSIT, 0);
17082cd038dSYoshinobu Inoue 		return;
17182cd038dSYoshinobu Inoue 	}
17282cd038dSYoshinobu Inoue 	ip6->ip6_hlim -= IPV6_HLIMDEC;
17382cd038dSYoshinobu Inoue 
174f8a8f9caSSUZUKI Shinsuke #ifdef IPSTEALTH
175f8a8f9caSSUZUKI Shinsuke 	}
176f8a8f9caSSUZUKI Shinsuke #endif
177f8a8f9caSSUZUKI Shinsuke 
178686cdd19SJun-ichiro itojun Hagino 	/*
179686cdd19SJun-ichiro itojun Hagino 	 * Save at most ICMPV6_PLD_MAXLEN (= the min IPv6 MTU -
180686cdd19SJun-ichiro itojun Hagino 	 * size of IPv6 + ICMPv6 headers) bytes of the packet in case
181686cdd19SJun-ichiro itojun Hagino 	 * we need to generate an ICMP6 message to the src.
182686cdd19SJun-ichiro itojun Hagino 	 * Thanks to M_EXT, in most cases copy will not occur.
183686cdd19SJun-ichiro itojun Hagino 	 *
184686cdd19SJun-ichiro itojun Hagino 	 * It is important to save it before IPsec processing as IPsec
185686cdd19SJun-ichiro itojun Hagino 	 * processing may modify the mbuf.
186686cdd19SJun-ichiro itojun Hagino 	 */
187686cdd19SJun-ichiro itojun Hagino 	mcopy = m_copy(m, 0, imin(m->m_pkthdr.len, ICMPV6_PLD_MAXLEN));
188686cdd19SJun-ichiro itojun Hagino 
189059e4684SJun-ichiro itojun Hagino #ifdef IPSEC
19082cd038dSYoshinobu Inoue 	/* get a security policy for this packet */
1917efe5d92SHajimu UMEMOTO 	sp = ipsec6_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND,
1927efe5d92SHajimu UMEMOTO 	    IP_FORWARDING, &error);
19382cd038dSYoshinobu Inoue 	if (sp == NULL) {
19482cd038dSYoshinobu Inoue 		ipsec6stat.out_inval++;
19582cd038dSYoshinobu Inoue 		ip6stat.ip6s_cantforward++;
196686cdd19SJun-ichiro itojun Hagino 		if (mcopy) {
197686cdd19SJun-ichiro itojun Hagino #if 0
198686cdd19SJun-ichiro itojun Hagino 			/* XXX: what icmp ? */
199686cdd19SJun-ichiro itojun Hagino #else
200686cdd19SJun-ichiro itojun Hagino 			m_freem(mcopy);
201686cdd19SJun-ichiro itojun Hagino #endif
202686cdd19SJun-ichiro itojun Hagino 		}
20382cd038dSYoshinobu Inoue 		m_freem(m);
20482cd038dSYoshinobu Inoue 		return;
20582cd038dSYoshinobu Inoue 	}
20682cd038dSYoshinobu Inoue 
20782cd038dSYoshinobu Inoue 	error = 0;
20882cd038dSYoshinobu Inoue 
20982cd038dSYoshinobu Inoue 	/* check policy */
21082cd038dSYoshinobu Inoue 	switch (sp->policy) {
21182cd038dSYoshinobu Inoue 	case IPSEC_POLICY_DISCARD:
21282cd038dSYoshinobu Inoue 		/*
21382cd038dSYoshinobu Inoue 		 * This packet is just discarded.
21482cd038dSYoshinobu Inoue 		 */
21582cd038dSYoshinobu Inoue 		ipsec6stat.out_polvio++;
21682cd038dSYoshinobu Inoue 		ip6stat.ip6s_cantforward++;
21782cd038dSYoshinobu Inoue 		key_freesp(sp);
218686cdd19SJun-ichiro itojun Hagino 		if (mcopy) {
219686cdd19SJun-ichiro itojun Hagino #if 0
220686cdd19SJun-ichiro itojun Hagino 			/* XXX: what icmp ? */
221686cdd19SJun-ichiro itojun Hagino #else
222686cdd19SJun-ichiro itojun Hagino 			m_freem(mcopy);
223686cdd19SJun-ichiro itojun Hagino #endif
224686cdd19SJun-ichiro itojun Hagino 		}
22582cd038dSYoshinobu Inoue 		m_freem(m);
22682cd038dSYoshinobu Inoue 		return;
22782cd038dSYoshinobu Inoue 
22882cd038dSYoshinobu Inoue 	case IPSEC_POLICY_BYPASS:
22982cd038dSYoshinobu Inoue 	case IPSEC_POLICY_NONE:
23082cd038dSYoshinobu Inoue 		/* no need to do IPsec. */
23182cd038dSYoshinobu Inoue 		key_freesp(sp);
23282cd038dSYoshinobu Inoue 		goto skip_ipsec;
23382cd038dSYoshinobu Inoue 
23482cd038dSYoshinobu Inoue 	case IPSEC_POLICY_IPSEC:
23582cd038dSYoshinobu Inoue 		if (sp->req == NULL) {
23682cd038dSYoshinobu Inoue 			/* XXX should be panic ? */
23782cd038dSYoshinobu Inoue 			printf("ip6_forward: No IPsec request specified.\n");
23882cd038dSYoshinobu Inoue 			ip6stat.ip6s_cantforward++;
23982cd038dSYoshinobu Inoue 			key_freesp(sp);
240686cdd19SJun-ichiro itojun Hagino 			if (mcopy) {
241686cdd19SJun-ichiro itojun Hagino #if 0
242686cdd19SJun-ichiro itojun Hagino 				/* XXX: what icmp ? */
243686cdd19SJun-ichiro itojun Hagino #else
244686cdd19SJun-ichiro itojun Hagino 				m_freem(mcopy);
245686cdd19SJun-ichiro itojun Hagino #endif
246686cdd19SJun-ichiro itojun Hagino 			}
24782cd038dSYoshinobu Inoue 			m_freem(m);
24882cd038dSYoshinobu Inoue 			return;
24982cd038dSYoshinobu Inoue 		}
25082cd038dSYoshinobu Inoue 		/* do IPsec */
25182cd038dSYoshinobu Inoue 		break;
25282cd038dSYoshinobu Inoue 
25382cd038dSYoshinobu Inoue 	case IPSEC_POLICY_ENTRUST:
25482cd038dSYoshinobu Inoue 	default:
25582cd038dSYoshinobu Inoue 		/* should be panic ?? */
25682cd038dSYoshinobu Inoue 		printf("ip6_forward: Invalid policy found. %d\n", sp->policy);
25782cd038dSYoshinobu Inoue 		key_freesp(sp);
25882cd038dSYoshinobu Inoue 		goto skip_ipsec;
25982cd038dSYoshinobu Inoue 	}
26082cd038dSYoshinobu Inoue 
26182cd038dSYoshinobu Inoue     {
2620f9ade71SHajimu UMEMOTO 	struct ipsecrequest *isr = NULL;
26382cd038dSYoshinobu Inoue 	struct ipsec_output_state state;
26482cd038dSYoshinobu Inoue 
26582cd038dSYoshinobu Inoue 	/*
2660f9ade71SHajimu UMEMOTO 	 * when the kernel forwards a packet, it is not proper to apply
2670f9ade71SHajimu UMEMOTO 	 * IPsec transport mode to the packet is not proper.  this check
2680f9ade71SHajimu UMEMOTO 	 * avoid from this.
2690f9ade71SHajimu UMEMOTO 	 * at present, if there is even a transport mode SA request in the
2700f9ade71SHajimu UMEMOTO 	 * security policy, the kernel does not apply IPsec to the packet.
2710f9ade71SHajimu UMEMOTO 	 * this check is not enough because the following case is valid.
2720f9ade71SHajimu UMEMOTO 	 *      ipsec esp/tunnel/xxx-xxx/require esp/transport//require;
2730f9ade71SHajimu UMEMOTO 	 */
2740f9ade71SHajimu UMEMOTO 	for (isr = sp->req; isr; isr = isr->next) {
275931282ceSHajimu UMEMOTO 		if (isr->saidx.mode == IPSEC_MODE_ANY)
276931282ceSHajimu UMEMOTO 			goto doipsectunnel;
277931282ceSHajimu UMEMOTO 		if (isr->saidx.mode == IPSEC_MODE_TUNNEL)
278931282ceSHajimu UMEMOTO 			goto doipsectunnel;
2790f9ade71SHajimu UMEMOTO 	}
2800f9ade71SHajimu UMEMOTO 
2810f9ade71SHajimu UMEMOTO 	/*
282931282ceSHajimu UMEMOTO 	 * if there's no need for tunnel mode IPsec, skip.
283931282ceSHajimu UMEMOTO 	 */
284931282ceSHajimu UMEMOTO 	if (!isr)
285931282ceSHajimu UMEMOTO 		goto skip_ipsec;
286931282ceSHajimu UMEMOTO 
287931282ceSHajimu UMEMOTO     doipsectunnel:
288931282ceSHajimu UMEMOTO 	/*
28982cd038dSYoshinobu Inoue 	 * All the extension headers will become inaccessible
29082cd038dSYoshinobu Inoue 	 * (since they can be encrypted).
29182cd038dSYoshinobu Inoue 	 * Don't panic, we need no more updates to extension headers
29282cd038dSYoshinobu Inoue 	 * on inner IPv6 packet (since they are now encapsulated).
29382cd038dSYoshinobu Inoue 	 *
29482cd038dSYoshinobu Inoue 	 * IPv6 [ESP|AH] IPv6 [extension headers] payload
29582cd038dSYoshinobu Inoue 	 */
29682cd038dSYoshinobu Inoue 	bzero(&state, sizeof(state));
29782cd038dSYoshinobu Inoue 	state.m = m;
29882cd038dSYoshinobu Inoue 	state.ro = NULL;	/* update at ipsec6_output_tunnel() */
29982cd038dSYoshinobu Inoue 	state.dst = NULL;	/* update at ipsec6_output_tunnel() */
30082cd038dSYoshinobu Inoue 
30182cd038dSYoshinobu Inoue 	error = ipsec6_output_tunnel(&state, sp, 0);
30282cd038dSYoshinobu Inoue 
30382cd038dSYoshinobu Inoue 	m = state.m;
30482cd038dSYoshinobu Inoue 	key_freesp(sp);
30582cd038dSYoshinobu Inoue 
30682cd038dSYoshinobu Inoue 	if (error) {
30782cd038dSYoshinobu Inoue 		/* mbuf is already reclaimed in ipsec6_output_tunnel. */
30882cd038dSYoshinobu Inoue 		switch (error) {
30982cd038dSYoshinobu Inoue 		case EHOSTUNREACH:
31082cd038dSYoshinobu Inoue 		case ENETUNREACH:
31182cd038dSYoshinobu Inoue 		case EMSGSIZE:
31282cd038dSYoshinobu Inoue 		case ENOBUFS:
31382cd038dSYoshinobu Inoue 		case ENOMEM:
31482cd038dSYoshinobu Inoue 			break;
31582cd038dSYoshinobu Inoue 		default:
31682cd038dSYoshinobu Inoue 			printf("ip6_output (ipsec): error code %d\n", error);
3177efe5d92SHajimu UMEMOTO 			/* FALLTHROUGH */
31882cd038dSYoshinobu Inoue 		case ENOENT:
31982cd038dSYoshinobu Inoue 			/* don't show these error codes to the user */
32082cd038dSYoshinobu Inoue 			break;
32182cd038dSYoshinobu Inoue 		}
32282cd038dSYoshinobu Inoue 		ip6stat.ip6s_cantforward++;
323686cdd19SJun-ichiro itojun Hagino 		if (mcopy) {
324686cdd19SJun-ichiro itojun Hagino #if 0
325686cdd19SJun-ichiro itojun Hagino 			/* XXX: what icmp ? */
326686cdd19SJun-ichiro itojun Hagino #else
327686cdd19SJun-ichiro itojun Hagino 			m_freem(mcopy);
328686cdd19SJun-ichiro itojun Hagino #endif
329686cdd19SJun-ichiro itojun Hagino 		}
33082cd038dSYoshinobu Inoue 		m_freem(m);
33182cd038dSYoshinobu Inoue 		return;
33282cd038dSYoshinobu Inoue 	}
3330f9ade71SHajimu UMEMOTO 
334931282ceSHajimu UMEMOTO 	if (ip6 != mtod(m, struct ip6_hdr *)) {
335931282ceSHajimu UMEMOTO 		/*
336931282ceSHajimu UMEMOTO 		 * now tunnel mode headers are added.  we are originating
337931282ceSHajimu UMEMOTO 		 * packet instead of forwarding the packet.
338931282ceSHajimu UMEMOTO 		 */
339931282ceSHajimu UMEMOTO 		ip6_output(m, NULL, NULL, IPV6_FORWARDING/*XXX*/, NULL, NULL,
340931282ceSHajimu UMEMOTO 		    NULL);
341931282ceSHajimu UMEMOTO 		goto freecopy;
342931282ceSHajimu UMEMOTO 	}
343931282ceSHajimu UMEMOTO 
3440f9ade71SHajimu UMEMOTO 	/* adjust pointer */
3450f9ade71SHajimu UMEMOTO 	dst = (struct sockaddr_in6 *)state.dst;
3460f9ade71SHajimu UMEMOTO 	rt = state.ro ? state.ro->ro_rt : NULL;
3470f9ade71SHajimu UMEMOTO 	if (dst != NULL && rt != NULL)
3480f9ade71SHajimu UMEMOTO 		ipsecrt = 1;
34982cd038dSYoshinobu Inoue     }
35082cd038dSYoshinobu Inoue     skip_ipsec:
351059e4684SJun-ichiro itojun Hagino #endif /* IPSEC */
35282cd038dSYoshinobu Inoue 
3530f9ade71SHajimu UMEMOTO #ifdef IPSEC
3540f9ade71SHajimu UMEMOTO 	if (ipsecrt)
3550f9ade71SHajimu UMEMOTO 		goto skip_routing;
3560f9ade71SHajimu UMEMOTO #endif
3570f9ade71SHajimu UMEMOTO 
35833841545SHajimu UMEMOTO 	dst = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst;
35982cd038dSYoshinobu Inoue 	if (!srcrt) {
3607efe5d92SHajimu UMEMOTO 		/* ip6_forward_rt.ro_dst.sin6_addr is equal to ip6->ip6_dst */
36182cd038dSYoshinobu Inoue 		if (ip6_forward_rt.ro_rt == 0 ||
36282cd038dSYoshinobu Inoue 		    (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) == 0) {
36382cd038dSYoshinobu Inoue 			if (ip6_forward_rt.ro_rt) {
36482cd038dSYoshinobu Inoue 				RTFREE(ip6_forward_rt.ro_rt);
36582cd038dSYoshinobu Inoue 				ip6_forward_rt.ro_rt = 0;
36682cd038dSYoshinobu Inoue 			}
3677efe5d92SHajimu UMEMOTO 
36882cd038dSYoshinobu Inoue 			/* this probably fails but give it a try again */
36926d02ca7SAndre Oppermann 			rtalloc((struct route *)&ip6_forward_rt);
37082cd038dSYoshinobu Inoue 		}
37182cd038dSYoshinobu Inoue 
37282cd038dSYoshinobu Inoue 		if (ip6_forward_rt.ro_rt == 0) {
37382cd038dSYoshinobu Inoue 			ip6stat.ip6s_noroute++;
37433841545SHajimu UMEMOTO 			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute);
375686cdd19SJun-ichiro itojun Hagino 			if (mcopy) {
376686cdd19SJun-ichiro itojun Hagino 				icmp6_error(mcopy, ICMP6_DST_UNREACH,
37782cd038dSYoshinobu Inoue 					    ICMP6_DST_UNREACH_NOROUTE, 0);
378686cdd19SJun-ichiro itojun Hagino 			}
379686cdd19SJun-ichiro itojun Hagino 			m_freem(m);
38082cd038dSYoshinobu Inoue 			return;
38182cd038dSYoshinobu Inoue 		}
38282cd038dSYoshinobu Inoue 	} else if ((rt = ip6_forward_rt.ro_rt) == 0 ||
38382cd038dSYoshinobu Inoue 		   !IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst->sin6_addr)) {
38482cd038dSYoshinobu Inoue 		if (ip6_forward_rt.ro_rt) {
38582cd038dSYoshinobu Inoue 			RTFREE(ip6_forward_rt.ro_rt);
38682cd038dSYoshinobu Inoue 			ip6_forward_rt.ro_rt = 0;
38782cd038dSYoshinobu Inoue 		}
38882cd038dSYoshinobu Inoue 		bzero(dst, sizeof(*dst));
38982cd038dSYoshinobu Inoue 		dst->sin6_len = sizeof(struct sockaddr_in6);
39082cd038dSYoshinobu Inoue 		dst->sin6_family = AF_INET6;
39182cd038dSYoshinobu Inoue 		dst->sin6_addr = ip6->ip6_dst;
39282cd038dSYoshinobu Inoue 
39326d02ca7SAndre Oppermann   		rtalloc((struct route *)&ip6_forward_rt);
39482cd038dSYoshinobu Inoue 		if (ip6_forward_rt.ro_rt == 0) {
39582cd038dSYoshinobu Inoue 			ip6stat.ip6s_noroute++;
39633841545SHajimu UMEMOTO 			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute);
397686cdd19SJun-ichiro itojun Hagino 			if (mcopy) {
398686cdd19SJun-ichiro itojun Hagino 				icmp6_error(mcopy, ICMP6_DST_UNREACH,
39982cd038dSYoshinobu Inoue 					    ICMP6_DST_UNREACH_NOROUTE, 0);
400686cdd19SJun-ichiro itojun Hagino 			}
401686cdd19SJun-ichiro itojun Hagino 			m_freem(m);
40282cd038dSYoshinobu Inoue 			return;
40382cd038dSYoshinobu Inoue 		}
40482cd038dSYoshinobu Inoue 	}
40582cd038dSYoshinobu Inoue 	rt = ip6_forward_rt.ro_rt;
4060f9ade71SHajimu UMEMOTO #ifdef IPSEC
4070f9ade71SHajimu UMEMOTO     skip_routing:;
4080f9ade71SHajimu UMEMOTO #endif
409686cdd19SJun-ichiro itojun Hagino 
410686cdd19SJun-ichiro itojun Hagino 	/*
411a1f7e5f8SHajimu UMEMOTO 	 * Source scope check: if a packet can't be delivered to its
412a1f7e5f8SHajimu UMEMOTO 	 * destination for the reason that the destination is beyond the scope
413a1f7e5f8SHajimu UMEMOTO 	 * of the source address, discard the packet and return an icmp6
414a1f7e5f8SHajimu UMEMOTO 	 * destination unreachable error with Code 2 (beyond scope of source
415a1f7e5f8SHajimu UMEMOTO 	 * address).  We use a local copy of ip6_src, since in6_setscope()
416a1f7e5f8SHajimu UMEMOTO 	 * will possibly modify its first argument.
417a1f7e5f8SHajimu UMEMOTO 	 * [draft-ietf-ipngwg-icmp-v3-04.txt, Section 3.1]
418686cdd19SJun-ichiro itojun Hagino 	 */
419a1f7e5f8SHajimu UMEMOTO 	src_in6 = ip6->ip6_src;
420a1f7e5f8SHajimu UMEMOTO 	if (in6_setscope(&src_in6, rt->rt_ifp, &outzone)) {
4210f9ade71SHajimu UMEMOTO 		/* XXX: this should not happen */
4220f9ade71SHajimu UMEMOTO 		ip6stat.ip6s_cantforward++;
4230f9ade71SHajimu UMEMOTO 		ip6stat.ip6s_badscope++;
4240f9ade71SHajimu UMEMOTO 		m_freem(m);
4250f9ade71SHajimu UMEMOTO 		return;
4260f9ade71SHajimu UMEMOTO 	}
427a1f7e5f8SHajimu UMEMOTO 	if (in6_setscope(&src_in6, m->m_pkthdr.rcvif, &inzone)) {
428a1f7e5f8SHajimu UMEMOTO 		ip6stat.ip6s_cantforward++;
429a1f7e5f8SHajimu UMEMOTO 		ip6stat.ip6s_badscope++;
430a1f7e5f8SHajimu UMEMOTO 		m_freem(m);
431a1f7e5f8SHajimu UMEMOTO 		return;
432a1f7e5f8SHajimu UMEMOTO 	}
433a1f7e5f8SHajimu UMEMOTO 	if (inzone != outzone
4340f9ade71SHajimu UMEMOTO #ifdef IPSEC
4350f9ade71SHajimu UMEMOTO 	    && !ipsecrt
4360f9ade71SHajimu UMEMOTO #endif
4370f9ade71SHajimu UMEMOTO 	    ) {
438686cdd19SJun-ichiro itojun Hagino 		ip6stat.ip6s_cantforward++;
439686cdd19SJun-ichiro itojun Hagino 		ip6stat.ip6s_badscope++;
440686cdd19SJun-ichiro itojun Hagino 		in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard);
441686cdd19SJun-ichiro itojun Hagino 
442686cdd19SJun-ichiro itojun Hagino 		if (ip6_log_time + ip6_log_interval < time_second) {
443686cdd19SJun-ichiro itojun Hagino 			ip6_log_time = time_second;
444686cdd19SJun-ichiro itojun Hagino 			log(LOG_DEBUG,
445686cdd19SJun-ichiro itojun Hagino 			    "cannot forward "
446686cdd19SJun-ichiro itojun Hagino 			    "src %s, dst %s, nxt %d, rcvif %s, outif %s\n",
4471d54aa3bSBjoern A. Zeeb 			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
4481d54aa3bSBjoern A. Zeeb 			    ip6_sprintf(ip6bufd, &ip6->ip6_dst),
449686cdd19SJun-ichiro itojun Hagino 			    ip6->ip6_nxt,
450686cdd19SJun-ichiro itojun Hagino 			    if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp));
451686cdd19SJun-ichiro itojun Hagino 		}
452686cdd19SJun-ichiro itojun Hagino 		if (mcopy)
453686cdd19SJun-ichiro itojun Hagino 			icmp6_error(mcopy, ICMP6_DST_UNREACH,
454686cdd19SJun-ichiro itojun Hagino 				    ICMP6_DST_UNREACH_BEYONDSCOPE, 0);
455686cdd19SJun-ichiro itojun Hagino 		m_freem(m);
456686cdd19SJun-ichiro itojun Hagino 		return;
457686cdd19SJun-ichiro itojun Hagino 	}
458686cdd19SJun-ichiro itojun Hagino 
459a1f7e5f8SHajimu UMEMOTO 	/*
460a1f7e5f8SHajimu UMEMOTO 	 * Destination scope check: if a packet is going to break the scope
461a1f7e5f8SHajimu UMEMOTO 	 * zone of packet's destination address, discard it.  This case should
462a1f7e5f8SHajimu UMEMOTO 	 * usually be prevented by appropriately-configured routing table, but
463a1f7e5f8SHajimu UMEMOTO 	 * we need an explicit check because we may mistakenly forward the
464a1f7e5f8SHajimu UMEMOTO 	 * packet to a different zone by (e.g.) a default route.
465a1f7e5f8SHajimu UMEMOTO 	 */
466a1f7e5f8SHajimu UMEMOTO 	dst_in6 = ip6->ip6_dst;
467a1f7e5f8SHajimu UMEMOTO 	if (in6_setscope(&dst_in6, m->m_pkthdr.rcvif, &inzone) != 0 ||
468a1f7e5f8SHajimu UMEMOTO 	    in6_setscope(&dst_in6, rt->rt_ifp, &outzone) != 0 ||
469a1f7e5f8SHajimu UMEMOTO 	    inzone != outzone) {
470a1f7e5f8SHajimu UMEMOTO 		ip6stat.ip6s_cantforward++;
471a1f7e5f8SHajimu UMEMOTO 		ip6stat.ip6s_badscope++;
472a1f7e5f8SHajimu UMEMOTO 		m_freem(m);
473a1f7e5f8SHajimu UMEMOTO 		return;
474a1f7e5f8SHajimu UMEMOTO 	}
475a1f7e5f8SHajimu UMEMOTO 
47631b3783cSHajimu UMEMOTO 	if (m->m_pkthdr.len > IN6_LINKMTU(rt->rt_ifp)) {
47782cd038dSYoshinobu Inoue 		in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig);
478686cdd19SJun-ichiro itojun Hagino 		if (mcopy) {
479686cdd19SJun-ichiro itojun Hagino 			u_long mtu;
480059e4684SJun-ichiro itojun Hagino #ifdef IPSEC
481686cdd19SJun-ichiro itojun Hagino 			struct secpolicy *sp;
482686cdd19SJun-ichiro itojun Hagino 			int ipsecerror;
483686cdd19SJun-ichiro itojun Hagino 			size_t ipsechdrsiz;
484686cdd19SJun-ichiro itojun Hagino #endif
485686cdd19SJun-ichiro itojun Hagino 
48631b3783cSHajimu UMEMOTO 			mtu = IN6_LINKMTU(rt->rt_ifp);
487059e4684SJun-ichiro itojun Hagino #ifdef IPSEC
488686cdd19SJun-ichiro itojun Hagino 			/*
489686cdd19SJun-ichiro itojun Hagino 			 * When we do IPsec tunnel ingress, we need to play
4900f9ade71SHajimu UMEMOTO 			 * with the link value (decrement IPsec header size
491686cdd19SJun-ichiro itojun Hagino 			 * from mtu value).  The code is much simpler than v4
492686cdd19SJun-ichiro itojun Hagino 			 * case, as we have the outgoing interface for
493686cdd19SJun-ichiro itojun Hagino 			 * encapsulated packet as "rt->rt_ifp".
494686cdd19SJun-ichiro itojun Hagino 			 */
495686cdd19SJun-ichiro itojun Hagino 			sp = ipsec6_getpolicybyaddr(mcopy, IPSEC_DIR_OUTBOUND,
496686cdd19SJun-ichiro itojun Hagino 				IP_FORWARDING, &ipsecerror);
497686cdd19SJun-ichiro itojun Hagino 			if (sp) {
498686cdd19SJun-ichiro itojun Hagino 				ipsechdrsiz = ipsec6_hdrsiz(mcopy,
499686cdd19SJun-ichiro itojun Hagino 					IPSEC_DIR_OUTBOUND, NULL);
500686cdd19SJun-ichiro itojun Hagino 				if (ipsechdrsiz < mtu)
501686cdd19SJun-ichiro itojun Hagino 					mtu -= ipsechdrsiz;
502686cdd19SJun-ichiro itojun Hagino 			}
503686cdd19SJun-ichiro itojun Hagino 
504686cdd19SJun-ichiro itojun Hagino 			/*
505686cdd19SJun-ichiro itojun Hagino 			 * if mtu becomes less than minimum MTU,
506686cdd19SJun-ichiro itojun Hagino 			 * tell minimum MTU (and I'll need to fragment it).
507686cdd19SJun-ichiro itojun Hagino 			 */
508686cdd19SJun-ichiro itojun Hagino 			if (mtu < IPV6_MMTU)
509686cdd19SJun-ichiro itojun Hagino 				mtu = IPV6_MMTU;
510686cdd19SJun-ichiro itojun Hagino #endif
511686cdd19SJun-ichiro itojun Hagino 			icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, mtu);
512686cdd19SJun-ichiro itojun Hagino 		}
513686cdd19SJun-ichiro itojun Hagino 		m_freem(m);
51482cd038dSYoshinobu Inoue 		return;
51582cd038dSYoshinobu Inoue 	}
51682cd038dSYoshinobu Inoue 
51782cd038dSYoshinobu Inoue 	if (rt->rt_flags & RTF_GATEWAY)
51882cd038dSYoshinobu Inoue 		dst = (struct sockaddr_in6 *)rt->rt_gateway;
51982cd038dSYoshinobu Inoue 
52082cd038dSYoshinobu Inoue 	/*
52182cd038dSYoshinobu Inoue 	 * If we are to forward the packet using the same interface
52282cd038dSYoshinobu Inoue 	 * as one we got the packet from, perhaps we should send a redirect
52382cd038dSYoshinobu Inoue 	 * to sender to shortcut a hop.
52482cd038dSYoshinobu Inoue 	 * Only send redirect if source is sending directly to us,
52582cd038dSYoshinobu Inoue 	 * and if packet was not source routed (or has any options).
52682cd038dSYoshinobu Inoue 	 * Also, don't send redirect if forwarding using a route
52782cd038dSYoshinobu Inoue 	 * modified by a redirect.
52882cd038dSYoshinobu Inoue 	 */
52980a684e0SJohn Hay 	if (ip6_sendredirects && rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt &&
5300f9ade71SHajimu UMEMOTO #ifdef IPSEC
5310f9ade71SHajimu UMEMOTO 	    !ipsecrt &&
5320f9ade71SHajimu UMEMOTO #endif
53333841545SHajimu UMEMOTO 	    (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0) {
53433841545SHajimu UMEMOTO 		if ((rt->rt_ifp->if_flags & IFF_POINTOPOINT) != 0) {
53533841545SHajimu UMEMOTO 			/*
53633841545SHajimu UMEMOTO 			 * If the incoming interface is equal to the outgoing
53733841545SHajimu UMEMOTO 			 * one, and the link attached to the interface is
53833841545SHajimu UMEMOTO 			 * point-to-point, then it will be highly probable
53933841545SHajimu UMEMOTO 			 * that a routing loop occurs. Thus, we immediately
54033841545SHajimu UMEMOTO 			 * drop the packet and send an ICMPv6 error message.
54133841545SHajimu UMEMOTO 			 *
54233841545SHajimu UMEMOTO 			 * type/code is based on suggestion by Rich Draves.
54333841545SHajimu UMEMOTO 			 * not sure if it is the best pick.
54433841545SHajimu UMEMOTO 			 */
54533841545SHajimu UMEMOTO 			icmp6_error(mcopy, ICMP6_DST_UNREACH,
54633841545SHajimu UMEMOTO 				    ICMP6_DST_UNREACH_ADDR, 0);
54733841545SHajimu UMEMOTO 			m_freem(m);
54833841545SHajimu UMEMOTO 			return;
54933841545SHajimu UMEMOTO 		}
55082cd038dSYoshinobu Inoue 		type = ND_REDIRECT;
55133841545SHajimu UMEMOTO 	}
55282cd038dSYoshinobu Inoue 
55382cd038dSYoshinobu Inoue 	/*
554686cdd19SJun-ichiro itojun Hagino 	 * Fake scoped addresses. Note that even link-local source or
555686cdd19SJun-ichiro itojun Hagino 	 * destinaion can appear, if the originating node just sends the
556686cdd19SJun-ichiro itojun Hagino 	 * packet to us (without address resolution for the destination).
557686cdd19SJun-ichiro itojun Hagino 	 * Since both icmp6_error and icmp6_redirect_output fill the embedded
55833841545SHajimu UMEMOTO 	 * link identifiers, we can do this stuff after making a copy for
55933841545SHajimu UMEMOTO 	 * returning an error.
560686cdd19SJun-ichiro itojun Hagino 	 */
561686cdd19SJun-ichiro itojun Hagino 	if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) {
562686cdd19SJun-ichiro itojun Hagino 		/*
563686cdd19SJun-ichiro itojun Hagino 		 * See corresponding comments in ip6_output.
564686cdd19SJun-ichiro itojun Hagino 		 * XXX: but is it possible that ip6_forward() sends a packet
565686cdd19SJun-ichiro itojun Hagino 		 *      to a loopback interface? I don't think so, and thus
566686cdd19SJun-ichiro itojun Hagino 		 *      I bark here. (jinmei@kame.net)
567686cdd19SJun-ichiro itojun Hagino 		 * XXX: it is common to route invalid packets to loopback.
568686cdd19SJun-ichiro itojun Hagino 		 *	also, the codepath will be visited on use of ::1 in
569686cdd19SJun-ichiro itojun Hagino 		 *	rthdr. (itojun)
570686cdd19SJun-ichiro itojun Hagino 		 */
571686cdd19SJun-ichiro itojun Hagino #if 1
572686cdd19SJun-ichiro itojun Hagino 		if (0)
573686cdd19SJun-ichiro itojun Hagino #else
574686cdd19SJun-ichiro itojun Hagino 		if ((rt->rt_flags & (RTF_BLACKHOLE|RTF_REJECT)) == 0)
575686cdd19SJun-ichiro itojun Hagino #endif
576686cdd19SJun-ichiro itojun Hagino 		{
577686cdd19SJun-ichiro itojun Hagino 			printf("ip6_forward: outgoing interface is loopback. "
578686cdd19SJun-ichiro itojun Hagino 			       "src %s, dst %s, nxt %d, rcvif %s, outif %s\n",
5791d54aa3bSBjoern A. Zeeb 			       ip6_sprintf(ip6bufs, &ip6->ip6_src),
5801d54aa3bSBjoern A. Zeeb 			       ip6_sprintf(ip6bufd, &ip6->ip6_dst),
581686cdd19SJun-ichiro itojun Hagino 			       ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif),
582686cdd19SJun-ichiro itojun Hagino 			       if_name(rt->rt_ifp));
583686cdd19SJun-ichiro itojun Hagino 		}
584686cdd19SJun-ichiro itojun Hagino 
58533841545SHajimu UMEMOTO 		/* we can just use rcvif in forwarding. */
58633841545SHajimu UMEMOTO 		origifp = m->m_pkthdr.rcvif;
587686cdd19SJun-ichiro itojun Hagino 	}
588686cdd19SJun-ichiro itojun Hagino 	else
589686cdd19SJun-ichiro itojun Hagino 		origifp = rt->rt_ifp;
59033841545SHajimu UMEMOTO 	/*
59133841545SHajimu UMEMOTO 	 * clear embedded scope identifiers if necessary.
59233841545SHajimu UMEMOTO 	 * in6_clearscope will touch the addresses only when necessary.
59333841545SHajimu UMEMOTO 	 */
59433841545SHajimu UMEMOTO 	in6_clearscope(&ip6->ip6_src);
59533841545SHajimu UMEMOTO 	in6_clearscope(&ip6->ip6_dst);
596686cdd19SJun-ichiro itojun Hagino 
597c21fd232SAndre Oppermann 	/* Jump over all PFIL processing if hooks are not active. */
598604afec4SChristian S.J. Peron 	if (!PFIL_HOOKED(&inet6_pfil_hook))
599c21fd232SAndre Oppermann 		goto pass;
600c21fd232SAndre Oppermann 
601c21fd232SAndre Oppermann 	/* Run through list of hooks for output packets. */
602d6a8d588SMax Laier 	error = pfil_run_hooks(&inet6_pfil_hook, &m, rt->rt_ifp, PFIL_OUT, NULL);
603b140bc1fSSam Leffler 	if (error != 0)
604b140bc1fSSam Leffler 		goto senderr;
6053a4d67f7SDarren Reed 	if (m == NULL)
6063a4d67f7SDarren Reed 		goto freecopy;
6073a4d67f7SDarren Reed 	ip6 = mtod(m, struct ip6_hdr *);
6083a4d67f7SDarren Reed 
609c21fd232SAndre Oppermann pass:
610686cdd19SJun-ichiro itojun Hagino 	error = nd6_output(rt->rt_ifp, origifp, m, dst, rt);
61182cd038dSYoshinobu Inoue 	if (error) {
61282cd038dSYoshinobu Inoue 		in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard);
61382cd038dSYoshinobu Inoue 		ip6stat.ip6s_cantforward++;
61482cd038dSYoshinobu Inoue 	} else {
61582cd038dSYoshinobu Inoue 		ip6stat.ip6s_forward++;
61682cd038dSYoshinobu Inoue 		in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward);
61782cd038dSYoshinobu Inoue 		if (type)
61882cd038dSYoshinobu Inoue 			ip6stat.ip6s_redirectsent++;
61982cd038dSYoshinobu Inoue 		else {
62082cd038dSYoshinobu Inoue 			if (mcopy)
62182cd038dSYoshinobu Inoue 				goto freecopy;
62282cd038dSYoshinobu Inoue 		}
62382cd038dSYoshinobu Inoue 	}
6247efe5d92SHajimu UMEMOTO 
625b140bc1fSSam Leffler senderr:
62682cd038dSYoshinobu Inoue 	if (mcopy == NULL)
62782cd038dSYoshinobu Inoue 		return;
62882cd038dSYoshinobu Inoue 	switch (error) {
62982cd038dSYoshinobu Inoue 	case 0:
63082cd038dSYoshinobu Inoue 		if (type == ND_REDIRECT) {
63182cd038dSYoshinobu Inoue 			icmp6_redirect_output(mcopy, rt);
63282cd038dSYoshinobu Inoue 			return;
63382cd038dSYoshinobu Inoue 		}
63482cd038dSYoshinobu Inoue 		goto freecopy;
63582cd038dSYoshinobu Inoue 
63682cd038dSYoshinobu Inoue 	case EMSGSIZE:
63782cd038dSYoshinobu Inoue 		/* xxx MTU is constant in PPP? */
63882cd038dSYoshinobu Inoue 		goto freecopy;
63982cd038dSYoshinobu Inoue 
64082cd038dSYoshinobu Inoue 	case ENOBUFS:
64182cd038dSYoshinobu Inoue 		/* Tell source to slow down like source quench in IP? */
64282cd038dSYoshinobu Inoue 		goto freecopy;
64382cd038dSYoshinobu Inoue 
64482cd038dSYoshinobu Inoue 	case ENETUNREACH:	/* shouldn't happen, checked above */
64582cd038dSYoshinobu Inoue 	case EHOSTUNREACH:
64682cd038dSYoshinobu Inoue 	case ENETDOWN:
64782cd038dSYoshinobu Inoue 	case EHOSTDOWN:
64882cd038dSYoshinobu Inoue 	default:
64982cd038dSYoshinobu Inoue 		type = ICMP6_DST_UNREACH;
65082cd038dSYoshinobu Inoue 		code = ICMP6_DST_UNREACH_ADDR;
65182cd038dSYoshinobu Inoue 		break;
65282cd038dSYoshinobu Inoue 	}
65382cd038dSYoshinobu Inoue 	icmp6_error(mcopy, type, code, 0);
65482cd038dSYoshinobu Inoue 	return;
65582cd038dSYoshinobu Inoue 
65682cd038dSYoshinobu Inoue  freecopy:
65782cd038dSYoshinobu Inoue 	m_freem(mcopy);
65882cd038dSYoshinobu Inoue 	return;
65982cd038dSYoshinobu Inoue }
660