1/*-
2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 *	$KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $
30 */
31
32/*-
33 * Copyright (c) 1982, 1986, 1988, 1993
34 *	The Regents of the University of California.  All rights reserved.
35 *
36 * Redistribution and use in source and binary forms, with or without
37 * modification, are permitted provided that the following conditions
38 * are met:
39 * 1. Redistributions of source code must retain the above copyright
40 *    notice, this list of conditions and the following disclaimer.
41 * 2. Redistributions in binary form must reproduce the above copyright
42 *    notice, this list of conditions and the following disclaimer in the
43 *    documentation and/or other materials provided with the distribution.
44 * 4. Neither the name of the University nor the names of its contributors
45 *    may be used to endorse or promote products derived from this software
46 *    without specific prior written permission.
47 *
48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58 * SUCH DAMAGE.
59 *
60 *	@(#)ip_input.c	8.2 (Berkeley) 1/4/94
61 */
62
63#include <sys/cdefs.h>
64__FBSDID("$FreeBSD$");
65
66#include "opt_inet.h"
67#include "opt_inet6.h"
68#include "opt_ipfw.h"
69#include "opt_ipsec.h"
70#include "opt_route.h"
71
72#include <sys/param.h>
73#include <sys/systm.h>
74#include <sys/malloc.h>
75#include <sys/mbuf.h>
76#include <sys/proc.h>
77#include <sys/domain.h>
78#include <sys/protosw.h>
79#include <sys/socket.h>
80#include <sys/socketvar.h>
81#include <sys/errno.h>
82#include <sys/time.h>
83#include <sys/kernel.h>
84#include <sys/syslog.h>
85
86#include <net/if.h>
87#include <net/if_types.h>
88#include <net/if_dl.h>
89#include <net/route.h>
90#include <net/netisr.h>
91#include <net/pfil.h>
92#include <net/vnet.h>
93
94#include <netinet/in.h>
95#include <netinet/ip_var.h>
96#include <netinet/in_systm.h>
97#include <net/if_llatbl.h>
98#ifdef INET
99#include <netinet/ip.h>
100#include <netinet/ip_icmp.h>
101#endif /* INET */
102#include <netinet/ip6.h>
103#include <netinet6/in6_var.h>
104#include <netinet6/ip6_var.h>
105#include <netinet/in_pcb.h>
106#include <netinet/icmp6.h>
107#include <netinet6/scope6_var.h>
108#include <netinet6/in6_ifattach.h>
109#include <netinet6/nd6.h>
110
111#ifdef IPSEC
112#include <netipsec/ipsec.h>
113#include <netinet6/ip6_ipsec.h>
114#include <netipsec/ipsec6.h>
115#endif /* IPSEC */
116
117#include <netinet6/ip6protosw.h>
118
119#ifdef FLOWTABLE
120#include <net/flowtable.h>
121VNET_DECLARE(int, ip6_output_flowtable_size);
122#define	V_ip6_output_flowtable_size	VNET(ip6_output_flowtable_size)
123#endif
124
125extern struct domain inet6domain;
126
127u_char ip6_protox[IPPROTO_MAX];
128VNET_DEFINE(struct in6_ifaddrhead, in6_ifaddrhead);
129
130static struct netisr_handler ip6_nh = {
131	.nh_name = "ip6",
132	.nh_handler = ip6_input,
133	.nh_proto = NETISR_IPV6,
134	.nh_policy = NETISR_POLICY_FLOW,
135};
136
137VNET_DECLARE(struct callout, in6_tmpaddrtimer_ch);
138#define	V_in6_tmpaddrtimer_ch		VNET(in6_tmpaddrtimer_ch)
139
140VNET_DEFINE(struct pfil_head, inet6_pfil_hook);
141
142VNET_DEFINE(struct ip6stat, ip6stat);
143
144struct rwlock in6_ifaddr_lock;
145RW_SYSINIT(in6_ifaddr_lock, &in6_ifaddr_lock, "in6_ifaddr_lock");
146
147static void ip6_init2(void *);
148static struct ip6aux *ip6_setdstifaddr(struct mbuf *, struct in6_ifaddr *);
149static struct ip6aux *ip6_addaux(struct mbuf *);
150static struct ip6aux *ip6_findaux(struct mbuf *m);
151static void ip6_delaux (struct mbuf *);
152static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *);
153#ifdef PULLDOWN_TEST
154static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int);
155#endif
156
157/*
158 * IP6 initialization: fill in IP6 protocol switch table.
159 * All protocols not implemented in kernel go to raw IP6 protocol handler.
160 */
161void
162ip6_init(void)
163{
164	struct ip6protosw *pr;
165	int i;
166
167	TUNABLE_INT_FETCH("net.inet6.ip6.auto_linklocal",
168	    &V_ip6_auto_linklocal);
169	TUNABLE_INT_FETCH("net.inet6.ip6.accept_rtadv", &V_ip6_accept_rtadv);
170	TUNABLE_INT_FETCH("net.inet6.ip6.no_radr", &V_ip6_no_radr);
171
172	TAILQ_INIT(&V_in6_ifaddrhead);
173
174	/* Initialize packet filter hooks. */
175	V_inet6_pfil_hook.ph_type = PFIL_TYPE_AF;
176	V_inet6_pfil_hook.ph_af = AF_INET6;
177	if ((i = pfil_head_register(&V_inet6_pfil_hook)) != 0)
178		printf("%s: WARNING: unable to register pfil hook, "
179			"error %d\n", __func__, i);
180
181	scope6_init();
182	addrsel_policy_init();
183	nd6_init();
184	frag6_init();
185
186#ifdef FLOWTABLE
187	if (TUNABLE_INT_FETCH("net.inet6.ip6.output_flowtable_size",
188		&V_ip6_output_flowtable_size)) {
189		if (V_ip6_output_flowtable_size < 256)
190			V_ip6_output_flowtable_size = 256;
191		if (!powerof2(V_ip6_output_flowtable_size)) {
192			printf("flowtable must be power of 2 size\n");
193			V_ip6_output_flowtable_size = 2048;
194		}
195	} else {
196		/*
197		 * round up to the next power of 2
198		 */
199		V_ip6_output_flowtable_size = 1 << fls((1024 + maxusers * 64)-1);
200	}
201	V_ip6_ft = flowtable_alloc("ipv6", V_ip6_output_flowtable_size, FL_IPV6|FL_PCPU);
202#endif
203
204	V_ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR;
205
206	/* Skip global initialization stuff for non-default instances. */
207	if (!IS_DEFAULT_VNET(curvnet))
208		return;
209
210#ifdef DIAGNOSTIC
211	if (sizeof(struct protosw) != sizeof(struct ip6protosw))
212		panic("sizeof(protosw) != sizeof(ip6protosw)");
213#endif
214	pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
215	if (pr == NULL)
216		panic("ip6_init");
217
218	/* Initialize the entire ip6_protox[] array to IPPROTO_RAW. */
219	for (i = 0; i < IPPROTO_MAX; i++)
220		ip6_protox[i] = pr - inet6sw;
221	/*
222	 * Cycle through IP protocols and put them into the appropriate place
223	 * in ip6_protox[].
224	 */
225	for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
226	    pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++)
227		if (pr->pr_domain->dom_family == PF_INET6 &&
228		    pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
229			/* Be careful to only index valid IP protocols. */
230			if (pr->pr_protocol < IPPROTO_MAX)
231				ip6_protox[pr->pr_protocol] = pr - inet6sw;
232		}
233
234	netisr_register(&ip6_nh);
235}
236
237/*
238 * The protocol to be inserted into ip6_protox[] must be already registered
239 * in inet6sw[], either statically or through pf_proto_register().
240 */
241int
242ip6proto_register(short ip6proto)
243{
244	struct ip6protosw *pr;
245
246	/* Sanity checks. */
247	if (ip6proto <= 0 || ip6proto >= IPPROTO_MAX)
248		return (EPROTONOSUPPORT);
249
250	/*
251	 * The protocol slot must not be occupied by another protocol
252	 * already.  An index pointing to IPPROTO_RAW is unused.
253	 */
254	pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
255	if (pr == NULL)
256		return (EPFNOSUPPORT);
257	if (ip6_protox[ip6proto] != pr - inet6sw)	/* IPPROTO_RAW */
258		return (EEXIST);
259
260	/*
261	 * Find the protocol position in inet6sw[] and set the index.
262	 */
263	for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
264	    pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) {
265		if (pr->pr_domain->dom_family == PF_INET6 &&
266		    pr->pr_protocol && pr->pr_protocol == ip6proto) {
267			ip6_protox[pr->pr_protocol] = pr - inet6sw;
268			return (0);
269		}
270	}
271	return (EPROTONOSUPPORT);
272}
273
274int
275ip6proto_unregister(short ip6proto)
276{
277	struct ip6protosw *pr;
278
279	/* Sanity checks. */
280	if (ip6proto <= 0 || ip6proto >= IPPROTO_MAX)
281		return (EPROTONOSUPPORT);
282
283	/* Check if the protocol was indeed registered. */
284	pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
285	if (pr == NULL)
286		return (EPFNOSUPPORT);
287	if (ip6_protox[ip6proto] == pr - inet6sw)	/* IPPROTO_RAW */
288		return (ENOENT);
289
290	/* Reset the protocol slot to IPPROTO_RAW. */
291	ip6_protox[ip6proto] = pr - inet6sw;
292	return (0);
293}
294
295#ifdef VIMAGE
296void
297ip6_destroy()
298{
299
300	nd6_destroy();
301	callout_drain(&V_in6_tmpaddrtimer_ch);
302}
303#endif
304
305static int
306ip6_init2_vnet(const void *unused __unused)
307{
308
309	/* nd6_timer_init */
310	callout_init(&V_nd6_timer_ch, 0);
311	callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet);
312
313	/* timer for regeneranation of temporary addresses randomize ID */
314	callout_init(&V_in6_tmpaddrtimer_ch, 0);
315	callout_reset(&V_in6_tmpaddrtimer_ch,
316		      (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor -
317		       V_ip6_temp_regen_advance) * hz,
318		      in6_tmpaddrtimer, curvnet);
319
320	return (0);
321}
322
323static void
324ip6_init2(void *dummy)
325{
326
327	ip6_init2_vnet(NULL);
328}
329
330/* cheat */
331/* This must be after route_init(), which is now SI_ORDER_THIRD */
332SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL);
333
334static int
335ip6_input_hbh(struct mbuf *m, uint32_t *plen, uint32_t *rtalert, int *off,
336    int *nxt, int *ours)
337{
338	struct ip6_hdr *ip6;
339	struct ip6_hbh *hbh;
340
341	if (ip6_hopopts_input(plen, rtalert, &m, off)) {
342#if 0	/*touches NULL pointer*/
343		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
344#endif
345		goto out;	/* m have already been freed */
346	}
347
348	/* adjust pointer */
349	ip6 = mtod(m, struct ip6_hdr *);
350
351	/*
352	 * if the payload length field is 0 and the next header field
353	 * indicates Hop-by-Hop Options header, then a Jumbo Payload
354	 * option MUST be included.
355	 */
356	if (ip6->ip6_plen == 0 && *plen == 0) {
357		/*
358		 * Note that if a valid jumbo payload option is
359		 * contained, ip6_hopopts_input() must set a valid
360		 * (non-zero) payload length to the variable plen.
361		 */
362		IP6STAT_INC(ip6s_badoptions);
363		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
364		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
365		icmp6_error(m, ICMP6_PARAM_PROB,
366			    ICMP6_PARAMPROB_HEADER,
367			    (caddr_t)&ip6->ip6_plen - (caddr_t)ip6);
368		goto out;
369	}
370#ifndef PULLDOWN_TEST
371	/* ip6_hopopts_input() ensures that mbuf is contiguous */
372	hbh = (struct ip6_hbh *)(ip6 + 1);
373#else
374	IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
375		sizeof(struct ip6_hbh));
376	if (hbh == NULL) {
377		IP6STAT_INC(ip6s_tooshort);
378		goto out;
379	}
380#endif
381	*nxt = hbh->ip6h_nxt;
382
383	/*
384	 * If we are acting as a router and the packet contains a
385	 * router alert option, see if we know the option value.
386	 * Currently, we only support the option value for MLD, in which
387	 * case we should pass the packet to the multicast routing
388	 * daemon.
389	 */
390	if (*rtalert != ~0) {
391		switch (*rtalert) {
392		case IP6OPT_RTALERT_MLD:
393			if (V_ip6_forwarding)
394				*ours = 1;
395			break;
396		default:
397			/*
398			 * RFC2711 requires unrecognized values must be
399			 * silently ignored.
400			 */
401			break;
402		}
403	}
404
405	return (0);
406
407out:
408	return (1);
409}
410
411void
412ip6_input(struct mbuf *m)
413{
414	struct ip6_hdr *ip6;
415	int off = sizeof(struct ip6_hdr), nest;
416	u_int32_t plen;
417	u_int32_t rtalert = ~0;
418	int nxt, ours = 0;
419	struct ifnet *deliverifp = NULL, *ifp = NULL;
420	struct in6_addr odst;
421	struct route_in6 rin6;
422	int srcrt = 0;
423	struct llentry *lle = NULL;
424	struct sockaddr_in6 dst6, *dst;
425
426	bzero(&rin6, sizeof(struct route_in6));
427#ifdef IPSEC
428	/*
429	 * should the inner packet be considered authentic?
430	 * see comment in ah4_input().
431	 * NB: m cannot be NULL when passed to the input routine
432	 */
433
434	m->m_flags &= ~M_AUTHIPHDR;
435	m->m_flags &= ~M_AUTHIPDGM;
436
437#endif /* IPSEC */
438
439	/*
440	 * make sure we don't have onion peering information into m_tag.
441	 */
442	ip6_delaux(m);
443
444	if (m->m_flags & M_FASTFWD_OURS) {
445		/*
446		 * Firewall changed destination to local.
447		 */
448		m->m_flags &= ~M_FASTFWD_OURS;
449		ours = 1;
450		deliverifp = m->m_pkthdr.rcvif;
451		ip6 = mtod(m, struct ip6_hdr *);
452		goto hbhcheck;
453	}
454
455	/*
456	 * mbuf statistics
457	 */
458	if (m->m_flags & M_EXT) {
459		if (m->m_next)
460			IP6STAT_INC(ip6s_mext2m);
461		else
462			IP6STAT_INC(ip6s_mext1);
463	} else {
464		if (m->m_next) {
465			if (m->m_flags & M_LOOP) {
466				IP6STAT_INC(ip6s_m2m[V_loif->if_index]);
467			} else if (m->m_pkthdr.rcvif->if_index < IP6S_M2MMAX)
468				IP6STAT_INC(
469				    ip6s_m2m[m->m_pkthdr.rcvif->if_index]);
470			else
471				IP6STAT_INC(ip6s_m2m[0]);
472		} else
473			IP6STAT_INC(ip6s_m1);
474	}
475
476	/* drop the packet if IPv6 operation is disabled on the IF */
477	if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) {
478		m_freem(m);
479		return;
480	}
481
482	in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive);
483	IP6STAT_INC(ip6s_total);
484
485#ifndef PULLDOWN_TEST
486	/*
487	 * L2 bridge code and some other code can return mbuf chain
488	 * that does not conform to KAME requirement.  too bad.
489	 * XXX: fails to join if interface MTU > MCLBYTES.  jumbogram?
490	 */
491	if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) {
492		struct mbuf *n;
493
494		MGETHDR(n, M_DONTWAIT, MT_HEADER);
495		if (n)
496			M_MOVE_PKTHDR(n, m);
497		if (n && n->m_pkthdr.len > MHLEN) {
498			MCLGET(n, M_DONTWAIT);
499			if ((n->m_flags & M_EXT) == 0) {
500				m_freem(n);
501				n = NULL;
502			}
503		}
504		if (n == NULL) {
505			m_freem(m);
506			return;	/* ENOBUFS */
507		}
508
509		m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
510		n->m_len = n->m_pkthdr.len;
511		m_freem(m);
512		m = n;
513	}
514	IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */);
515#endif
516
517	if (m->m_len < sizeof(struct ip6_hdr)) {
518		struct ifnet *inifp;
519		inifp = m->m_pkthdr.rcvif;
520		if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
521			IP6STAT_INC(ip6s_toosmall);
522			in6_ifstat_inc(inifp, ifs6_in_hdrerr);
523			return;
524		}
525	}
526
527	ip6 = mtod(m, struct ip6_hdr *);
528
529	if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
530		IP6STAT_INC(ip6s_badvers);
531		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
532		goto bad;
533	}
534
535	IP6STAT_INC(ip6s_nxthist[ip6->ip6_nxt]);
536
537	/*
538	 * Check against address spoofing/corruption.
539	 */
540	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) ||
541	    IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) {
542		/*
543		 * XXX: "badscope" is not very suitable for a multicast source.
544		 */
545		IP6STAT_INC(ip6s_badscope);
546		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
547		goto bad;
548	}
549	if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) &&
550	    !(m->m_flags & M_LOOP)) {
551		/*
552		 * In this case, the packet should come from the loopback
553		 * interface.  However, we cannot just check the if_flags,
554		 * because ip6_mloopback() passes the "actual" interface
555		 * as the outgoing/incoming interface.
556		 */
557		IP6STAT_INC(ip6s_badscope);
558		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
559		goto bad;
560	}
561	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
562	    IPV6_ADDR_MC_SCOPE(&ip6->ip6_dst) == 0) {
563		/*
564		 * RFC4291 2.7:
565		 * Nodes must not originate a packet to a multicast address
566		 * whose scop field contains the reserved value 0; if such
567		 * a packet is received, it must be silently dropped.
568		 */
569		IP6STAT_INC(ip6s_badscope);
570		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
571		goto bad;
572	}
573#ifdef ALTQ
574	if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) {
575		/* packet is dropped by traffic conditioner */
576		return;
577	}
578#endif
579	/*
580	 * The following check is not documented in specs.  A malicious
581	 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack
582	 * and bypass security checks (act as if it was from 127.0.0.1 by using
583	 * IPv6 src ::ffff:127.0.0.1).  Be cautious.
584	 *
585	 * This check chokes if we are in an SIIT cloud.  As none of BSDs
586	 * support IPv4-less kernel compilation, we cannot support SIIT
587	 * environment at all.  So, it makes more sense for us to reject any
588	 * malicious packets for non-SIIT environment, than try to do a
589	 * partial support for SIIT environment.
590	 */
591	if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
592	    IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
593		IP6STAT_INC(ip6s_badscope);
594		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
595		goto bad;
596	}
597#if 0
598	/*
599	 * Reject packets with IPv4 compatible addresses (auto tunnel).
600	 *
601	 * The code forbids auto tunnel relay case in RFC1933 (the check is
602	 * stronger than RFC1933).  We may want to re-enable it if mech-xx
603	 * is revised to forbid relaying case.
604	 */
605	if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
606	    IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
607		IP6STAT_INC(ip6s_badscope);
608		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
609		goto bad;
610	}
611#endif
612#ifdef IPSEC
613	/*
614	 * Bypass packet filtering for packets previously handled by IPsec.
615	 */
616	if (ip6_ipsec_filtertunnel(m))
617		goto passin;
618#endif /* IPSEC */
619
620	/*
621	 * Run through list of hooks for input packets.
622	 *
623	 * NB: Beware of the destination address changing
624	 *     (e.g. by NAT rewriting).  When this happens,
625	 *     tell ip6_forward to do the right thing.
626	 */
627	odst = ip6->ip6_dst;
628
629	/* Jump over all PFIL processing if hooks are not active. */
630	if (!PFIL_HOOKED(&V_inet6_pfil_hook))
631		goto passin;
632
633	if (pfil_run_hooks(&V_inet6_pfil_hook, &m,
634	    m->m_pkthdr.rcvif, PFIL_IN, NULL))
635		return;
636	if (m == NULL)			/* consumed by filter */
637		return;
638	ip6 = mtod(m, struct ip6_hdr *);
639	srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst);
640
641	if (m->m_flags & M_FASTFWD_OURS) {
642		m->m_flags &= ~M_FASTFWD_OURS;
643		ours = 1;
644		deliverifp = m->m_pkthdr.rcvif;
645		goto hbhcheck;
646	}
647	if ((m->m_flags & M_IP6_NEXTHOP) &&
648	    m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL) {
649		/*
650		 * Directly ship the packet on.  This allows forwarding
651		 * packets originally destined to us to some other directly
652		 * connected host.
653		 */
654		ip6_forward(m, 1);
655		goto out;
656	}
657
658passin:
659	/*
660	 * Disambiguate address scope zones (if there is ambiguity).
661	 * We first make sure that the original source or destination address
662	 * is not in our internal form for scoped addresses.  Such addresses
663	 * are not necessarily invalid spec-wise, but we cannot accept them due
664	 * to the usage conflict.
665	 * in6_setscope() then also checks and rejects the cases where src or
666	 * dst are the loopback address and the receiving interface
667	 * is not loopback.
668	 */
669	if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) {
670		IP6STAT_INC(ip6s_badscope); /* XXX */
671		goto bad;
672	}
673	if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) ||
674	    in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) {
675		IP6STAT_INC(ip6s_badscope);
676		goto bad;
677	}
678
679	/*
680	 * Multicast check. Assume packet is for us to avoid
681	 * prematurely taking locks.
682	 */
683	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
684		ours = 1;
685		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast);
686		deliverifp = m->m_pkthdr.rcvif;
687		goto hbhcheck;
688	}
689
690	/*
691	 *  Unicast check
692	 */
693
694	bzero(&dst6, sizeof(dst6));
695	dst6.sin6_family = AF_INET6;
696	dst6.sin6_len = sizeof(struct sockaddr_in6);
697	dst6.sin6_addr = ip6->ip6_dst;
698	ifp = m->m_pkthdr.rcvif;
699	IF_AFDATA_RLOCK(ifp);
700	lle = lla_lookup(LLTABLE6(ifp), 0,
701	     (struct sockaddr *)&dst6);
702	IF_AFDATA_RUNLOCK(ifp);
703	if ((lle != NULL) && (lle->la_flags & LLE_IFADDR)) {
704		struct ifaddr *ifa;
705		struct in6_ifaddr *ia6;
706		int bad;
707
708		bad = 1;
709#define	sa_equal(a1, a2)						\
710	(bcmp((a1), (a2), ((a1))->sin6_len) == 0)
711		IF_ADDR_RLOCK(ifp);
712		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
713			if (ifa->ifa_addr->sa_family != dst6.sin6_family)
714				continue;
715			if (sa_equal(&dst6, ifa->ifa_addr))
716				break;
717		}
718		KASSERT(ifa != NULL, ("%s: ifa not found for lle %p",
719		    __func__, lle));
720#undef sa_equal
721
722		ia6 = (struct in6_ifaddr *)ifa;
723		if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
724			/* Count the packet in the ip address stats */
725			ia6->ia_ifa.if_ipackets++;
726			ia6->ia_ifa.if_ibytes += m->m_pkthdr.len;
727
728			/*
729			 * record address information into m_tag.
730			 */
731			(void)ip6_setdstifaddr(m, ia6);
732
733			bad = 0;
734		} else {
735			char ip6bufs[INET6_ADDRSTRLEN];
736			char ip6bufd[INET6_ADDRSTRLEN];
737			/* address is not ready, so discard the packet. */
738			nd6log((LOG_INFO,
739			    "ip6_input: packet to an unready address %s->%s\n",
740			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
741			    ip6_sprintf(ip6bufd, &ip6->ip6_dst)));
742		}
743		IF_ADDR_RUNLOCK(ifp);
744		LLE_RUNLOCK(lle);
745		if (bad)
746			goto bad;
747		else {
748			ours = 1;
749			deliverifp = ifp;
750			goto hbhcheck;
751		}
752	}
753	if (lle != NULL)
754		LLE_RUNLOCK(lle);
755
756	dst = &rin6.ro_dst;
757	dst->sin6_len = sizeof(struct sockaddr_in6);
758	dst->sin6_family = AF_INET6;
759	dst->sin6_addr = ip6->ip6_dst;
760	rin6.ro_rt = in6_rtalloc1((struct sockaddr *)dst, 0, 0, M_GETFIB(m));
761	if (rin6.ro_rt)
762		RT_UNLOCK(rin6.ro_rt);
763
764#define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key))
765
766	/*
767	 * Accept the packet if the forwarding interface to the destination
768	 * according to the routing table is the loopback interface,
769	 * unless the associated route has a gateway.
770	 * Note that this approach causes to accept a packet if there is a
771	 * route to the loopback interface for the destination of the packet.
772	 * But we think it's even useful in some situations, e.g. when using
773	 * a special daemon which wants to intercept the packet.
774	 *
775	 * XXX: some OSes automatically make a cloned route for the destination
776	 * of an outgoing packet.  If the outgoing interface of the packet
777	 * is a loopback one, the kernel would consider the packet to be
778	 * accepted, even if we have no such address assinged on the interface.
779	 * We check the cloned flag of the route entry to reject such cases,
780	 * assuming that route entries for our own addresses are not made by
781	 * cloning (it should be true because in6_addloop explicitly installs
782	 * the host route).  However, we might have to do an explicit check
783	 * while it would be less efficient.  Or, should we rather install a
784	 * reject route for such a case?
785	 */
786	if (rin6.ro_rt &&
787	    (rin6.ro_rt->rt_flags &
788	     (RTF_HOST|RTF_GATEWAY)) == RTF_HOST &&
789#ifdef RTF_WASCLONED
790	    !(rin6.ro_rt->rt_flags & RTF_WASCLONED) &&
791#endif
792#ifdef RTF_CLONED
793	    !(rin6.ro_rt->rt_flags & RTF_CLONED) &&
794#endif
795#if 0
796	    /*
797	     * The check below is redundant since the comparison of
798	     * the destination and the key of the rtentry has
799	     * already done through looking up the routing table.
800	     */
801	    IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
802	    &rt6_key(rin6.ro_rt)->sin6_addr)
803#endif
804	    rin6.ro_rt->rt_ifp->if_type == IFT_LOOP) {
805		int free_ia6 = 0;
806		struct in6_ifaddr *ia6;
807
808		/*
809		 * found the loopback route to the interface address
810		 */
811		if (rin6.ro_rt->rt_gateway->sa_family == AF_LINK) {
812			struct sockaddr_in6 dest6;
813
814			bzero(&dest6, sizeof(dest6));
815			dest6.sin6_family = AF_INET6;
816			dest6.sin6_len = sizeof(dest6);
817			dest6.sin6_addr = ip6->ip6_dst;
818			ia6 = (struct in6_ifaddr *)
819			    ifa_ifwithaddr((struct sockaddr *)&dest6);
820			if (ia6 == NULL)
821				goto bad;
822			free_ia6 = 1;
823		}
824		else
825			ia6 = (struct in6_ifaddr *)rin6.ro_rt->rt_ifa;
826
827		/*
828		 * record address information into m_tag.
829		 */
830		(void)ip6_setdstifaddr(m, ia6);
831
832		/*
833		 * packets to a tentative, duplicated, or somehow invalid
834		 * address must not be accepted.
835		 */
836		if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
837			/* this address is ready */
838			ours = 1;
839			deliverifp = ia6->ia_ifp;	/* correct? */
840			/* Count the packet in the ip address stats */
841			ia6->ia_ifa.if_ipackets++;
842			ia6->ia_ifa.if_ibytes += m->m_pkthdr.len;
843			if (ia6 != NULL && free_ia6 != 0)
844				ifa_free(&ia6->ia_ifa);
845			goto hbhcheck;
846		} else {
847			char ip6bufs[INET6_ADDRSTRLEN];
848			char ip6bufd[INET6_ADDRSTRLEN];
849			/* address is not ready, so discard the packet. */
850			nd6log((LOG_INFO,
851			    "ip6_input: packet to an unready address %s->%s\n",
852			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
853			    ip6_sprintf(ip6bufd, &ip6->ip6_dst)));
854
855			if (ia6 != NULL && free_ia6 != 0)
856				ifa_free(&ia6->ia_ifa);
857			goto bad;
858		}
859	}
860
861	/*
862	 * FAITH (Firewall Aided Internet Translator)
863	 */
864	if (V_ip6_keepfaith) {
865		if (rin6.ro_rt && rin6.ro_rt->rt_ifp &&
866		    rin6.ro_rt->rt_ifp->if_type == IFT_FAITH) {
867			/* XXX do we need more sanity checks? */
868			ours = 1;
869			deliverifp = rin6.ro_rt->rt_ifp; /* faith */
870			goto hbhcheck;
871		}
872	}
873
874	/*
875	 * Now there is no reason to process the packet if it's not our own
876	 * and we're not a router.
877	 */
878	if (!V_ip6_forwarding) {
879		IP6STAT_INC(ip6s_cantforward);
880		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
881		goto bad;
882	}
883
884  hbhcheck:
885	/*
886	 * record address information into m_tag, if we don't have one yet.
887	 * note that we are unable to record it, if the address is not listed
888	 * as our interface address (e.g. multicast addresses, addresses
889	 * within FAITH prefixes and such).
890	 */
891	if (deliverifp) {
892		struct in6_ifaddr *ia6;
893
894 		if ((ia6 = ip6_getdstifaddr(m)) != NULL) {
895			ifa_free(&ia6->ia_ifa);
896		} else {
897			ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst);
898			if (ia6) {
899				if (!ip6_setdstifaddr(m, ia6)) {
900					/*
901					 * XXX maybe we should drop the packet here,
902					 * as we could not provide enough information
903					 * to the upper layers.
904					 */
905				}
906				ifa_free(&ia6->ia_ifa);
907			}
908		}
909	}
910
911	/*
912	 * Process Hop-by-Hop options header if it's contained.
913	 * m may be modified in ip6_hopopts_input().
914	 * If a JumboPayload option is included, plen will also be modified.
915	 */
916	plen = (u_int32_t)ntohs(ip6->ip6_plen);
917	if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
918		int error;
919
920		error = ip6_input_hbh(m, &plen, &rtalert, &off, &nxt, &ours);
921		if (error != 0)
922			goto out;
923	} else
924		nxt = ip6->ip6_nxt;
925
926	/*
927	 * Check that the amount of data in the buffers
928	 * is as at least much as the IPv6 header would have us expect.
929	 * Trim mbufs if longer than we expect.
930	 * Drop packet if shorter than we expect.
931	 */
932	if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
933		IP6STAT_INC(ip6s_tooshort);
934		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
935		goto bad;
936	}
937	if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
938		if (m->m_len == m->m_pkthdr.len) {
939			m->m_len = sizeof(struct ip6_hdr) + plen;
940			m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen;
941		} else
942			m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len);
943	}
944
945	/*
946	 * Forward if desirable.
947	 */
948	if (V_ip6_mrouter &&
949	    IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
950		/*
951		 * If we are acting as a multicast router, all
952		 * incoming multicast packets are passed to the
953		 * kernel-level multicast forwarding function.
954		 * The packet is returned (relatively) intact; if
955		 * ip6_mforward() returns a non-zero value, the packet
956		 * must be discarded, else it may be accepted below.
957		 *
958		 * XXX TODO: Check hlim and multicast scope here to avoid
959		 * unnecessarily calling into ip6_mforward().
960		 */
961		if (ip6_mforward &&
962		    ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) {
963			IP6STAT_INC(ip6s_cantforward);
964			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
965			goto bad;
966		}
967	} else if (!ours) {
968		ip6_forward(m, srcrt);
969		goto out;
970	}
971
972	ip6 = mtod(m, struct ip6_hdr *);
973
974	/*
975	 * Malicious party may be able to use IPv4 mapped addr to confuse
976	 * tcp/udp stack and bypass security checks (act as if it was from
977	 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1).  Be cautious.
978	 *
979	 * For SIIT end node behavior, you may want to disable the check.
980	 * However, you will  become vulnerable to attacks using IPv4 mapped
981	 * source.
982	 */
983	if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
984	    IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
985		IP6STAT_INC(ip6s_badscope);
986		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
987		goto bad;
988	}
989
990	/*
991	 * Tell launch routine the next header
992	 */
993	IP6STAT_INC(ip6s_delivered);
994	in6_ifstat_inc(deliverifp, ifs6_in_deliver);
995	nest = 0;
996
997	while (nxt != IPPROTO_DONE) {
998		if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) {
999			IP6STAT_INC(ip6s_toomanyhdr);
1000			goto bad;
1001		}
1002
1003		/*
1004		 * protection against faulty packet - there should be
1005		 * more sanity checks in header chain processing.
1006		 */
1007		if (m->m_pkthdr.len < off) {
1008			IP6STAT_INC(ip6s_tooshort);
1009			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
1010			goto bad;
1011		}
1012
1013#ifdef IPSEC
1014		/*
1015		 * enforce IPsec policy checking if we are seeing last header.
1016		 * note that we do not visit this with protocols with pcb layer
1017		 * code - like udp/tcp/raw ip.
1018		 */
1019		if (ip6_ipsec_input(m, nxt))
1020			goto bad;
1021#endif /* IPSEC */
1022
1023		/*
1024		 * Use mbuf flags to propagate Router Alert option to
1025		 * ICMPv6 layer, as hop-by-hop options have been stripped.
1026		 */
1027		if (nxt == IPPROTO_ICMPV6 && rtalert != ~0)
1028			m->m_flags |= M_RTALERT_MLD;
1029
1030		nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt);
1031	}
1032	goto out;
1033bad:
1034	m_freem(m);
1035out:
1036	if (rin6.ro_rt)
1037		RTFREE(rin6.ro_rt);
1038}
1039
1040/*
1041 * set/grab in6_ifaddr correspond to IPv6 destination address.
1042 * XXX backward compatibility wrapper
1043 *
1044 * XXXRW: We should bump the refcount on ia6 before sticking it in the m_tag,
1045 * and then bump it when the tag is copied, and release it when the tag is
1046 * freed.  Unfortunately, m_tags don't support deep copies (yet), so instead
1047 * we just bump the ia refcount when we receive it.  This should be fixed.
1048 */
1049static struct ip6aux *
1050ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6)
1051{
1052	struct ip6aux *ip6a;
1053
1054	ip6a = ip6_addaux(m);
1055	if (ip6a)
1056		ip6a->ip6a_dstia6 = ia6;
1057	return ip6a;	/* NULL if failed to set */
1058}
1059
1060struct in6_ifaddr *
1061ip6_getdstifaddr(struct mbuf *m)
1062{
1063	struct ip6aux *ip6a;
1064	struct in6_ifaddr *ia;
1065
1066	ip6a = ip6_findaux(m);
1067	if (ip6a) {
1068		ia = ip6a->ip6a_dstia6;
1069		ifa_ref(&ia->ia_ifa);
1070		return ia;
1071	} else
1072		return NULL;
1073}
1074
1075/*
1076 * Hop-by-Hop options header processing. If a valid jumbo payload option is
1077 * included, the real payload length will be stored in plenp.
1078 *
1079 * rtalertp - XXX: should be stored more smart way
1080 */
1081static int
1082ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp,
1083    struct mbuf **mp, int *offp)
1084{
1085	struct mbuf *m = *mp;
1086	int off = *offp, hbhlen;
1087	struct ip6_hbh *hbh;
1088
1089	/* validation of the length of the header */
1090#ifndef PULLDOWN_TEST
1091	IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1);
1092	hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
1093	hbhlen = (hbh->ip6h_len + 1) << 3;
1094
1095	IP6_EXTHDR_CHECK(m, off, hbhlen, -1);
1096	hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
1097#else
1098	IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
1099		sizeof(struct ip6_hdr), sizeof(struct ip6_hbh));
1100	if (hbh == NULL) {
1101		IP6STAT_INC(ip6s_tooshort);
1102		return -1;
1103	}
1104	hbhlen = (hbh->ip6h_len + 1) << 3;
1105	IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
1106		hbhlen);
1107	if (hbh == NULL) {
1108		IP6STAT_INC(ip6s_tooshort);
1109		return -1;
1110	}
1111#endif
1112	off += hbhlen;
1113	hbhlen -= sizeof(struct ip6_hbh);
1114	if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh),
1115				hbhlen, rtalertp, plenp) < 0)
1116		return (-1);
1117
1118	*offp = off;
1119	*mp = m;
1120	return (0);
1121}
1122
1123/*
1124 * Search header for all Hop-by-hop options and process each option.
1125 * This function is separate from ip6_hopopts_input() in order to
1126 * handle a case where the sending node itself process its hop-by-hop
1127 * options header. In such a case, the function is called from ip6_output().
1128 *
1129 * The function assumes that hbh header is located right after the IPv6 header
1130 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to
1131 * opthead + hbhlen is located in contiguous memory region.
1132 */
1133int
1134ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen,
1135    u_int32_t *rtalertp, u_int32_t *plenp)
1136{
1137	struct ip6_hdr *ip6;
1138	int optlen = 0;
1139	u_int8_t *opt = opthead;
1140	u_int16_t rtalert_val;
1141	u_int32_t jumboplen;
1142	const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh);
1143
1144	for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
1145		switch (*opt) {
1146		case IP6OPT_PAD1:
1147			optlen = 1;
1148			break;
1149		case IP6OPT_PADN:
1150			if (hbhlen < IP6OPT_MINLEN) {
1151				IP6STAT_INC(ip6s_toosmall);
1152				goto bad;
1153			}
1154			optlen = *(opt + 1) + 2;
1155			break;
1156		case IP6OPT_ROUTER_ALERT:
1157			/* XXX may need check for alignment */
1158			if (hbhlen < IP6OPT_RTALERT_LEN) {
1159				IP6STAT_INC(ip6s_toosmall);
1160				goto bad;
1161			}
1162			if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
1163				/* XXX stat */
1164				icmp6_error(m, ICMP6_PARAM_PROB,
1165				    ICMP6_PARAMPROB_HEADER,
1166				    erroff + opt + 1 - opthead);
1167				return (-1);
1168			}
1169			optlen = IP6OPT_RTALERT_LEN;
1170			bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2);
1171			*rtalertp = ntohs(rtalert_val);
1172			break;
1173		case IP6OPT_JUMBO:
1174			/* XXX may need check for alignment */
1175			if (hbhlen < IP6OPT_JUMBO_LEN) {
1176				IP6STAT_INC(ip6s_toosmall);
1177				goto bad;
1178			}
1179			if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
1180				/* XXX stat */
1181				icmp6_error(m, ICMP6_PARAM_PROB,
1182				    ICMP6_PARAMPROB_HEADER,
1183				    erroff + opt + 1 - opthead);
1184				return (-1);
1185			}
1186			optlen = IP6OPT_JUMBO_LEN;
1187
1188			/*
1189			 * IPv6 packets that have non 0 payload length
1190			 * must not contain a jumbo payload option.
1191			 */
1192			ip6 = mtod(m, struct ip6_hdr *);
1193			if (ip6->ip6_plen) {
1194				IP6STAT_INC(ip6s_badoptions);
1195				icmp6_error(m, ICMP6_PARAM_PROB,
1196				    ICMP6_PARAMPROB_HEADER,
1197				    erroff + opt - opthead);
1198				return (-1);
1199			}
1200
1201			/*
1202			 * We may see jumbolen in unaligned location, so
1203			 * we'd need to perform bcopy().
1204			 */
1205			bcopy(opt + 2, &jumboplen, sizeof(jumboplen));
1206			jumboplen = (u_int32_t)htonl(jumboplen);
1207
1208#if 1
1209			/*
1210			 * if there are multiple jumbo payload options,
1211			 * *plenp will be non-zero and the packet will be
1212			 * rejected.
1213			 * the behavior may need some debate in ipngwg -
1214			 * multiple options does not make sense, however,
1215			 * there's no explicit mention in specification.
1216			 */
1217			if (*plenp != 0) {
1218				IP6STAT_INC(ip6s_badoptions);
1219				icmp6_error(m, ICMP6_PARAM_PROB,
1220				    ICMP6_PARAMPROB_HEADER,
1221				    erroff + opt + 2 - opthead);
1222				return (-1);
1223			}
1224#endif
1225
1226			/*
1227			 * jumbo payload length must be larger than 65535.
1228			 */
1229			if (jumboplen <= IPV6_MAXPACKET) {
1230				IP6STAT_INC(ip6s_badoptions);
1231				icmp6_error(m, ICMP6_PARAM_PROB,
1232				    ICMP6_PARAMPROB_HEADER,
1233				    erroff + opt + 2 - opthead);
1234				return (-1);
1235			}
1236			*plenp = jumboplen;
1237
1238			break;
1239		default:		/* unknown option */
1240			if (hbhlen < IP6OPT_MINLEN) {
1241				IP6STAT_INC(ip6s_toosmall);
1242				goto bad;
1243			}
1244			optlen = ip6_unknown_opt(opt, m,
1245			    erroff + opt - opthead);
1246			if (optlen == -1)
1247				return (-1);
1248			optlen += 2;
1249			break;
1250		}
1251	}
1252
1253	return (0);
1254
1255  bad:
1256	m_freem(m);
1257	return (-1);
1258}
1259
1260/*
1261 * Unknown option processing.
1262 * The third argument `off' is the offset from the IPv6 header to the option,
1263 * which is necessary if the IPv6 header the and option header and IPv6 header
1264 * is not contiguous in order to return an ICMPv6 error.
1265 */
1266int
1267ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off)
1268{
1269	struct ip6_hdr *ip6;
1270
1271	switch (IP6OPT_TYPE(*optp)) {
1272	case IP6OPT_TYPE_SKIP: /* ignore the option */
1273		return ((int)*(optp + 1));
1274	case IP6OPT_TYPE_DISCARD:	/* silently discard */
1275		m_freem(m);
1276		return (-1);
1277	case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */
1278		IP6STAT_INC(ip6s_badoptions);
1279		icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
1280		return (-1);
1281	case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
1282		IP6STAT_INC(ip6s_badoptions);
1283		ip6 = mtod(m, struct ip6_hdr *);
1284		if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
1285		    (m->m_flags & (M_BCAST|M_MCAST)))
1286			m_freem(m);
1287		else
1288			icmp6_error(m, ICMP6_PARAM_PROB,
1289				    ICMP6_PARAMPROB_OPTION, off);
1290		return (-1);
1291	}
1292
1293	m_freem(m);		/* XXX: NOTREACHED */
1294	return (-1);
1295}
1296
1297/*
1298 * Create the "control" list for this pcb.
1299 * These functions will not modify mbuf chain at all.
1300 *
1301 * With KAME mbuf chain restriction:
1302 * The routine will be called from upper layer handlers like tcp6_input().
1303 * Thus the routine assumes that the caller (tcp6_input) have already
1304 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the
1305 * very first mbuf on the mbuf chain.
1306 *
1307 * ip6_savecontrol_v4 will handle those options that are possible to be
1308 * set on a v4-mapped socket.
1309 * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those
1310 * options and handle the v6-only ones itself.
1311 */
1312struct mbuf **
1313ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp,
1314    int *v4only)
1315{
1316	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1317
1318#ifdef SO_TIMESTAMP
1319	if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) {
1320		struct timeval tv;
1321
1322		microtime(&tv);
1323		*mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1324		    SCM_TIMESTAMP, SOL_SOCKET);
1325		if (*mp)
1326			mp = &(*mp)->m_next;
1327	}
1328#endif
1329
1330#define IS2292(inp, x, y)	(((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y))
1331	/* RFC 2292 sec. 5 */
1332	if ((inp->inp_flags & IN6P_PKTINFO) != 0) {
1333		struct in6_pktinfo pi6;
1334
1335		if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1336#ifdef INET
1337			struct ip *ip;
1338
1339			ip = mtod(m, struct ip *);
1340			pi6.ipi6_addr.s6_addr32[0] = 0;
1341			pi6.ipi6_addr.s6_addr32[1] = 0;
1342			pi6.ipi6_addr.s6_addr32[2] = IPV6_ADDR_INT32_SMP;
1343			pi6.ipi6_addr.s6_addr32[3] = ip->ip_dst.s_addr;
1344#else
1345			/* We won't hit this code */
1346			bzero(&pi6.ipi6_addr, sizeof(struct in6_addr));
1347#endif
1348		} else {
1349			bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr));
1350			in6_clearscope(&pi6.ipi6_addr);	/* XXX */
1351		}
1352		pi6.ipi6_ifindex =
1353		    (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0;
1354
1355		*mp = sbcreatecontrol((caddr_t) &pi6,
1356		    sizeof(struct in6_pktinfo),
1357		    IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6);
1358		if (*mp)
1359			mp = &(*mp)->m_next;
1360	}
1361
1362	if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) {
1363		int hlim;
1364
1365		if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1366#ifdef INET
1367			struct ip *ip;
1368
1369			ip = mtod(m, struct ip *);
1370			hlim = ip->ip_ttl;
1371#else
1372			/* We won't hit this code */
1373			hlim = 0;
1374#endif
1375		} else {
1376			hlim = ip6->ip6_hlim & 0xff;
1377		}
1378		*mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int),
1379		    IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT),
1380		    IPPROTO_IPV6);
1381		if (*mp)
1382			mp = &(*mp)->m_next;
1383	}
1384
1385	if ((inp->inp_flags & IN6P_TCLASS) != 0) {
1386		int tclass;
1387
1388		if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1389#ifdef INET
1390			struct ip *ip;
1391
1392			ip = mtod(m, struct ip *);
1393			tclass = ip->ip_tos;
1394#else
1395			/* We won't hit this code */
1396			tclass = 0;
1397#endif
1398		} else {
1399			u_int32_t flowinfo;
1400
1401			flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK);
1402			flowinfo >>= 20;
1403			tclass = flowinfo & 0xff;
1404		}
1405		*mp = sbcreatecontrol((caddr_t) &tclass, sizeof(int),
1406		    IPV6_TCLASS, IPPROTO_IPV6);
1407		if (*mp)
1408			mp = &(*mp)->m_next;
1409	}
1410
1411	if (v4only != NULL) {
1412		if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1413			*v4only = 1;
1414		} else {
1415			*v4only = 0;
1416		}
1417	}
1418
1419	return (mp);
1420}
1421
1422void
1423ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp)
1424{
1425	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1426	int v4only = 0;
1427
1428	mp = ip6_savecontrol_v4(in6p, m, mp, &v4only);
1429	if (v4only)
1430		return;
1431
1432	/*
1433	 * IPV6_HOPOPTS socket option.  Recall that we required super-user
1434	 * privilege for the option (see ip6_ctloutput), but it might be too
1435	 * strict, since there might be some hop-by-hop options which can be
1436	 * returned to normal user.
1437	 * See also RFC 2292 section 6 (or RFC 3542 section 8).
1438	 */
1439	if ((in6p->inp_flags & IN6P_HOPOPTS) != 0) {
1440		/*
1441		 * Check if a hop-by-hop options header is contatined in the
1442		 * received packet, and if so, store the options as ancillary
1443		 * data. Note that a hop-by-hop options header must be
1444		 * just after the IPv6 header, which is assured through the
1445		 * IPv6 input processing.
1446		 */
1447		if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
1448			struct ip6_hbh *hbh;
1449			int hbhlen = 0;
1450#ifdef PULLDOWN_TEST
1451			struct mbuf *ext;
1452#endif
1453
1454#ifndef PULLDOWN_TEST
1455			hbh = (struct ip6_hbh *)(ip6 + 1);
1456			hbhlen = (hbh->ip6h_len + 1) << 3;
1457#else
1458			ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr),
1459			    ip6->ip6_nxt);
1460			if (ext == NULL) {
1461				IP6STAT_INC(ip6s_tooshort);
1462				return;
1463			}
1464			hbh = mtod(ext, struct ip6_hbh *);
1465			hbhlen = (hbh->ip6h_len + 1) << 3;
1466			if (hbhlen != ext->m_len) {
1467				m_freem(ext);
1468				IP6STAT_INC(ip6s_tooshort);
1469				return;
1470			}
1471#endif
1472
1473			/*
1474			 * XXX: We copy the whole header even if a
1475			 * jumbo payload option is included, the option which
1476			 * is to be removed before returning according to
1477			 * RFC2292.
1478			 * Note: this constraint is removed in RFC3542
1479			 */
1480			*mp = sbcreatecontrol((caddr_t)hbh, hbhlen,
1481			    IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS),
1482			    IPPROTO_IPV6);
1483			if (*mp)
1484				mp = &(*mp)->m_next;
1485#ifdef PULLDOWN_TEST
1486			m_freem(ext);
1487#endif
1488		}
1489	}
1490
1491	if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) {
1492		int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);
1493
1494		/*
1495		 * Search for destination options headers or routing
1496		 * header(s) through the header chain, and stores each
1497		 * header as ancillary data.
1498		 * Note that the order of the headers remains in
1499		 * the chain of ancillary data.
1500		 */
1501		while (1) {	/* is explicit loop prevention necessary? */
1502			struct ip6_ext *ip6e = NULL;
1503			int elen;
1504#ifdef PULLDOWN_TEST
1505			struct mbuf *ext = NULL;
1506#endif
1507
1508			/*
1509			 * if it is not an extension header, don't try to
1510			 * pull it from the chain.
1511			 */
1512			switch (nxt) {
1513			case IPPROTO_DSTOPTS:
1514			case IPPROTO_ROUTING:
1515			case IPPROTO_HOPOPTS:
1516			case IPPROTO_AH: /* is it possible? */
1517				break;
1518			default:
1519				goto loopend;
1520			}
1521
1522#ifndef PULLDOWN_TEST
1523			if (off + sizeof(*ip6e) > m->m_len)
1524				goto loopend;
1525			ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
1526			if (nxt == IPPROTO_AH)
1527				elen = (ip6e->ip6e_len + 2) << 2;
1528			else
1529				elen = (ip6e->ip6e_len + 1) << 3;
1530			if (off + elen > m->m_len)
1531				goto loopend;
1532#else
1533			ext = ip6_pullexthdr(m, off, nxt);
1534			if (ext == NULL) {
1535				IP6STAT_INC(ip6s_tooshort);
1536				return;
1537			}
1538			ip6e = mtod(ext, struct ip6_ext *);
1539			if (nxt == IPPROTO_AH)
1540				elen = (ip6e->ip6e_len + 2) << 2;
1541			else
1542				elen = (ip6e->ip6e_len + 1) << 3;
1543			if (elen != ext->m_len) {
1544				m_freem(ext);
1545				IP6STAT_INC(ip6s_tooshort);
1546				return;
1547			}
1548#endif
1549
1550			switch (nxt) {
1551			case IPPROTO_DSTOPTS:
1552				if (!(in6p->inp_flags & IN6P_DSTOPTS))
1553					break;
1554
1555				*mp = sbcreatecontrol((caddr_t)ip6e, elen,
1556				    IS2292(in6p,
1557					IPV6_2292DSTOPTS, IPV6_DSTOPTS),
1558				    IPPROTO_IPV6);
1559				if (*mp)
1560					mp = &(*mp)->m_next;
1561				break;
1562			case IPPROTO_ROUTING:
1563				if (!(in6p->inp_flags & IN6P_RTHDR))
1564					break;
1565
1566				*mp = sbcreatecontrol((caddr_t)ip6e, elen,
1567				    IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR),
1568				    IPPROTO_IPV6);
1569				if (*mp)
1570					mp = &(*mp)->m_next;
1571				break;
1572			case IPPROTO_HOPOPTS:
1573			case IPPROTO_AH: /* is it possible? */
1574				break;
1575
1576			default:
1577				/*
1578				 * other cases have been filtered in the above.
1579				 * none will visit this case.  here we supply
1580				 * the code just in case (nxt overwritten or
1581				 * other cases).
1582				 */
1583#ifdef PULLDOWN_TEST
1584				m_freem(ext);
1585#endif
1586				goto loopend;
1587
1588			}
1589
1590			/* proceed with the next header. */
1591			off += elen;
1592			nxt = ip6e->ip6e_nxt;
1593			ip6e = NULL;
1594#ifdef PULLDOWN_TEST
1595			m_freem(ext);
1596			ext = NULL;
1597#endif
1598		}
1599	  loopend:
1600		;
1601	}
1602}
1603#undef IS2292
1604
1605void
1606ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu)
1607{
1608	struct socket *so;
1609	struct mbuf *m_mtu;
1610	struct ip6_mtuinfo mtuctl;
1611
1612	so =  in6p->inp_socket;
1613
1614	if (mtu == NULL)
1615		return;
1616
1617#ifdef DIAGNOSTIC
1618	if (so == NULL)		/* I believe this is impossible */
1619		panic("ip6_notify_pmtu: socket is NULL");
1620#endif
1621
1622	bzero(&mtuctl, sizeof(mtuctl));	/* zero-clear for safety */
1623	mtuctl.ip6m_mtu = *mtu;
1624	mtuctl.ip6m_addr = *dst;
1625	if (sa6_recoverscope(&mtuctl.ip6m_addr))
1626		return;
1627
1628	if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl),
1629	    IPV6_PATHMTU, IPPROTO_IPV6)) == NULL)
1630		return;
1631
1632	if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu)
1633	    == 0) {
1634		m_freem(m_mtu);
1635		/* XXX: should count statistics */
1636	} else
1637		sorwakeup(so);
1638
1639	return;
1640}
1641
1642#ifdef PULLDOWN_TEST
1643/*
1644 * pull single extension header from mbuf chain.  returns single mbuf that
1645 * contains the result, or NULL on error.
1646 */
1647static struct mbuf *
1648ip6_pullexthdr(struct mbuf *m, size_t off, int nxt)
1649{
1650	struct ip6_ext ip6e;
1651	size_t elen;
1652	struct mbuf *n;
1653
1654#ifdef DIAGNOSTIC
1655	switch (nxt) {
1656	case IPPROTO_DSTOPTS:
1657	case IPPROTO_ROUTING:
1658	case IPPROTO_HOPOPTS:
1659	case IPPROTO_AH: /* is it possible? */
1660		break;
1661	default:
1662		printf("ip6_pullexthdr: invalid nxt=%d\n", nxt);
1663	}
1664#endif
1665
1666	m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1667	if (nxt == IPPROTO_AH)
1668		elen = (ip6e.ip6e_len + 2) << 2;
1669	else
1670		elen = (ip6e.ip6e_len + 1) << 3;
1671
1672	MGET(n, M_DONTWAIT, MT_DATA);
1673	if (n && elen >= MLEN) {
1674		MCLGET(n, M_DONTWAIT);
1675		if ((n->m_flags & M_EXT) == 0) {
1676			m_free(n);
1677			n = NULL;
1678		}
1679	}
1680	if (!n)
1681		return NULL;
1682
1683	n->m_len = 0;
1684	if (elen >= M_TRAILINGSPACE(n)) {
1685		m_free(n);
1686		return NULL;
1687	}
1688
1689	m_copydata(m, off, elen, mtod(n, caddr_t));
1690	n->m_len = elen;
1691	return n;
1692}
1693#endif
1694
1695/*
1696 * Get pointer to the previous header followed by the header
1697 * currently processed.
1698 * XXX: This function supposes that
1699 *	M includes all headers,
1700 *	the next header field and the header length field of each header
1701 *	are valid, and
1702 *	the sum of each header length equals to OFF.
1703 * Because of these assumptions, this function must be called very
1704 * carefully. Moreover, it will not be used in the near future when
1705 * we develop `neater' mechanism to process extension headers.
1706 */
1707char *
1708ip6_get_prevhdr(struct mbuf *m, int off)
1709{
1710	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1711
1712	if (off == sizeof(struct ip6_hdr))
1713		return (&ip6->ip6_nxt);
1714	else {
1715		int len, nxt;
1716		struct ip6_ext *ip6e = NULL;
1717
1718		nxt = ip6->ip6_nxt;
1719		len = sizeof(struct ip6_hdr);
1720		while (len < off) {
1721			ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len);
1722
1723			switch (nxt) {
1724			case IPPROTO_FRAGMENT:
1725				len += sizeof(struct ip6_frag);
1726				break;
1727			case IPPROTO_AH:
1728				len += (ip6e->ip6e_len + 2) << 2;
1729				break;
1730			default:
1731				len += (ip6e->ip6e_len + 1) << 3;
1732				break;
1733			}
1734			nxt = ip6e->ip6e_nxt;
1735		}
1736		if (ip6e)
1737			return (&ip6e->ip6e_nxt);
1738		else
1739			return NULL;
1740	}
1741}
1742
1743/*
1744 * get next header offset.  m will be retained.
1745 */
1746int
1747ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp)
1748{
1749	struct ip6_hdr ip6;
1750	struct ip6_ext ip6e;
1751	struct ip6_frag fh;
1752
1753	/* just in case */
1754	if (m == NULL)
1755		panic("ip6_nexthdr: m == NULL");
1756	if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off)
1757		return -1;
1758
1759	switch (proto) {
1760	case IPPROTO_IPV6:
1761		if (m->m_pkthdr.len < off + sizeof(ip6))
1762			return -1;
1763		m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6);
1764		if (nxtp)
1765			*nxtp = ip6.ip6_nxt;
1766		off += sizeof(ip6);
1767		return off;
1768
1769	case IPPROTO_FRAGMENT:
1770		/*
1771		 * terminate parsing if it is not the first fragment,
1772		 * it does not make sense to parse through it.
1773		 */
1774		if (m->m_pkthdr.len < off + sizeof(fh))
1775			return -1;
1776		m_copydata(m, off, sizeof(fh), (caddr_t)&fh);
1777		/* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */
1778		if (fh.ip6f_offlg & IP6F_OFF_MASK)
1779			return -1;
1780		if (nxtp)
1781			*nxtp = fh.ip6f_nxt;
1782		off += sizeof(struct ip6_frag);
1783		return off;
1784
1785	case IPPROTO_AH:
1786		if (m->m_pkthdr.len < off + sizeof(ip6e))
1787			return -1;
1788		m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1789		if (nxtp)
1790			*nxtp = ip6e.ip6e_nxt;
1791		off += (ip6e.ip6e_len + 2) << 2;
1792		return off;
1793
1794	case IPPROTO_HOPOPTS:
1795	case IPPROTO_ROUTING:
1796	case IPPROTO_DSTOPTS:
1797		if (m->m_pkthdr.len < off + sizeof(ip6e))
1798			return -1;
1799		m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1800		if (nxtp)
1801			*nxtp = ip6e.ip6e_nxt;
1802		off += (ip6e.ip6e_len + 1) << 3;
1803		return off;
1804
1805	case IPPROTO_NONE:
1806	case IPPROTO_ESP:
1807	case IPPROTO_IPCOMP:
1808		/* give up */
1809		return -1;
1810
1811	default:
1812		return -1;
1813	}
1814
1815	return -1;
1816}
1817
1818/*
1819 * get offset for the last header in the chain.  m will be kept untainted.
1820 */
1821int
1822ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp)
1823{
1824	int newoff;
1825	int nxt;
1826
1827	if (!nxtp) {
1828		nxt = -1;
1829		nxtp = &nxt;
1830	}
1831	while (1) {
1832		newoff = ip6_nexthdr(m, off, proto, nxtp);
1833		if (newoff < 0)
1834			return off;
1835		else if (newoff < off)
1836			return -1;	/* invalid */
1837		else if (newoff == off)
1838			return newoff;
1839
1840		off = newoff;
1841		proto = *nxtp;
1842	}
1843}
1844
1845static struct ip6aux *
1846ip6_addaux(struct mbuf *m)
1847{
1848	struct m_tag *mtag;
1849
1850	mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1851	if (!mtag) {
1852		mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux),
1853		    M_NOWAIT);
1854		if (mtag) {
1855			m_tag_prepend(m, mtag);
1856			bzero(mtag + 1, sizeof(struct ip6aux));
1857		}
1858	}
1859	return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
1860}
1861
1862static struct ip6aux *
1863ip6_findaux(struct mbuf *m)
1864{
1865	struct m_tag *mtag;
1866
1867	mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1868	return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
1869}
1870
1871static void
1872ip6_delaux(struct mbuf *m)
1873{
1874	struct m_tag *mtag;
1875
1876	mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1877	if (mtag)
1878		m_tag_delete(m, mtag);
1879}
1880
1881/*
1882 * System control for IP6
1883 */
1884
1885u_char	inet6ctlerrmap[PRC_NCMDS] = {
1886	0,		0,		0,		0,
1887	0,		EMSGSIZE,	EHOSTDOWN,	EHOSTUNREACH,
1888	EHOSTUNREACH,	EHOSTUNREACH,	ECONNREFUSED,	ECONNREFUSED,
1889	EMSGSIZE,	EHOSTUNREACH,	0,		0,
1890	0,		0,		0,		0,
1891	ENOPROTOOPT
1892};
1893