ip6_input.c revision 242079
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: head/sys/netinet6/ip6_input.c 242079 2012-10-25 09:39:14Z ae $");
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		V_ip6stat.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		V_ip6stat.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			V_ip6stat.ip6s_mext2m++;
461		else
462			V_ip6stat.ip6s_mext1++;
463	} else {
464#define M2MMAX	(sizeof(V_ip6stat.ip6s_m2m)/sizeof(V_ip6stat.ip6s_m2m[0]))
465		if (m->m_next) {
466			if (m->m_flags & M_LOOP) {
467				V_ip6stat.ip6s_m2m[V_loif->if_index]++;
468			} else if (m->m_pkthdr.rcvif->if_index < M2MMAX)
469				V_ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++;
470			else
471				V_ip6stat.ip6s_m2m[0]++;
472		} else
473			V_ip6stat.ip6s_m1++;
474#undef M2MMAX
475	}
476
477	/* drop the packet if IPv6 operation is disabled on the IF */
478	if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) {
479		m_freem(m);
480		return;
481	}
482
483	in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive);
484	V_ip6stat.ip6s_total++;
485
486#ifndef PULLDOWN_TEST
487	/*
488	 * L2 bridge code and some other code can return mbuf chain
489	 * that does not conform to KAME requirement.  too bad.
490	 * XXX: fails to join if interface MTU > MCLBYTES.  jumbogram?
491	 */
492	if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) {
493		struct mbuf *n;
494
495		MGETHDR(n, M_DONTWAIT, MT_HEADER);
496		if (n)
497			M_MOVE_PKTHDR(n, m);
498		if (n && n->m_pkthdr.len > MHLEN) {
499			MCLGET(n, M_DONTWAIT);
500			if ((n->m_flags & M_EXT) == 0) {
501				m_freem(n);
502				n = NULL;
503			}
504		}
505		if (n == NULL) {
506			m_freem(m);
507			return;	/* ENOBUFS */
508		}
509
510		m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
511		n->m_len = n->m_pkthdr.len;
512		m_freem(m);
513		m = n;
514	}
515	IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */);
516#endif
517
518	if (m->m_len < sizeof(struct ip6_hdr)) {
519		struct ifnet *inifp;
520		inifp = m->m_pkthdr.rcvif;
521		if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
522			V_ip6stat.ip6s_toosmall++;
523			in6_ifstat_inc(inifp, ifs6_in_hdrerr);
524			return;
525		}
526	}
527
528	ip6 = mtod(m, struct ip6_hdr *);
529
530	if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
531		V_ip6stat.ip6s_badvers++;
532		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
533		goto bad;
534	}
535
536	V_ip6stat.ip6s_nxthist[ip6->ip6_nxt]++;
537
538	/*
539	 * Check against address spoofing/corruption.
540	 */
541	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) ||
542	    IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) {
543		/*
544		 * XXX: "badscope" is not very suitable for a multicast source.
545		 */
546		V_ip6stat.ip6s_badscope++;
547		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
548		goto bad;
549	}
550	if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) &&
551	    !(m->m_flags & M_LOOP)) {
552		/*
553		 * In this case, the packet should come from the loopback
554		 * interface.  However, we cannot just check the if_flags,
555		 * because ip6_mloopback() passes the "actual" interface
556		 * as the outgoing/incoming interface.
557		 */
558		V_ip6stat.ip6s_badscope++;
559		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
560		goto bad;
561	}
562
563#ifdef ALTQ
564	if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) {
565		/* packet is dropped by traffic conditioner */
566		return;
567	}
568#endif
569	/*
570	 * The following check is not documented in specs.  A malicious
571	 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack
572	 * and bypass security checks (act as if it was from 127.0.0.1 by using
573	 * IPv6 src ::ffff:127.0.0.1).  Be cautious.
574	 *
575	 * This check chokes if we are in an SIIT cloud.  As none of BSDs
576	 * support IPv4-less kernel compilation, we cannot support SIIT
577	 * environment at all.  So, it makes more sense for us to reject any
578	 * malicious packets for non-SIIT environment, than try to do a
579	 * partial support for SIIT environment.
580	 */
581	if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
582	    IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
583		V_ip6stat.ip6s_badscope++;
584		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
585		goto bad;
586	}
587#if 0
588	/*
589	 * Reject packets with IPv4 compatible addresses (auto tunnel).
590	 *
591	 * The code forbids auto tunnel relay case in RFC1933 (the check is
592	 * stronger than RFC1933).  We may want to re-enable it if mech-xx
593	 * is revised to forbid relaying case.
594	 */
595	if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
596	    IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
597		V_ip6stat.ip6s_badscope++;
598		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
599		goto bad;
600	}
601#endif
602#ifdef IPSEC
603	/*
604	 * Bypass packet filtering for packets previously handled by IPsec.
605	 */
606	if (ip6_ipsec_filtertunnel(m))
607		goto passin;
608#endif /* IPSEC */
609
610	/*
611	 * Run through list of hooks for input packets.
612	 *
613	 * NB: Beware of the destination address changing
614	 *     (e.g. by NAT rewriting).  When this happens,
615	 *     tell ip6_forward to do the right thing.
616	 */
617	odst = ip6->ip6_dst;
618
619	/* Jump over all PFIL processing if hooks are not active. */
620	if (!PFIL_HOOKED(&V_inet6_pfil_hook))
621		goto passin;
622
623	if (pfil_run_hooks(&V_inet6_pfil_hook, &m,
624	    m->m_pkthdr.rcvif, PFIL_IN, NULL))
625		return;
626	if (m == NULL)			/* consumed by filter */
627		return;
628	ip6 = mtod(m, struct ip6_hdr *);
629	srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst);
630
631	if (V_pfilforward == 0)
632		goto passin;
633	if (m->m_flags & M_FASTFWD_OURS) {
634		m->m_flags &= ~M_FASTFWD_OURS;
635		ours = 1;
636		deliverifp = m->m_pkthdr.rcvif;
637		goto hbhcheck;
638	}
639	if (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL) {
640		/*
641		 * Directly ship the packet on.  This allows forwarding
642		 * packets originally destined to us to some other directly
643		 * connected host.
644		 */
645		ip6_forward(m, 1);
646		goto out;
647	}
648
649passin:
650	/*
651	 * Disambiguate address scope zones (if there is ambiguity).
652	 * We first make sure that the original source or destination address
653	 * is not in our internal form for scoped addresses.  Such addresses
654	 * are not necessarily invalid spec-wise, but we cannot accept them due
655	 * to the usage conflict.
656	 * in6_setscope() then also checks and rejects the cases where src or
657	 * dst are the loopback address and the receiving interface
658	 * is not loopback.
659	 */
660	if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) {
661		V_ip6stat.ip6s_badscope++; /* XXX */
662		goto bad;
663	}
664	if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) ||
665	    in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) {
666		V_ip6stat.ip6s_badscope++;
667		goto bad;
668	}
669
670	/*
671	 * Multicast check. Assume packet is for us to avoid
672	 * prematurely taking locks.
673	 */
674	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
675		ours = 1;
676		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast);
677		deliverifp = m->m_pkthdr.rcvif;
678		goto hbhcheck;
679	}
680
681	/*
682	 *  Unicast check
683	 */
684
685	bzero(&dst6, sizeof(dst6));
686	dst6.sin6_family = AF_INET6;
687	dst6.sin6_len = sizeof(struct sockaddr_in6);
688	dst6.sin6_addr = ip6->ip6_dst;
689	ifp = m->m_pkthdr.rcvif;
690	IF_AFDATA_LOCK(ifp);
691	lle = lla_lookup(LLTABLE6(ifp), 0,
692	     (struct sockaddr *)&dst6);
693	IF_AFDATA_UNLOCK(ifp);
694	if ((lle != NULL) && (lle->la_flags & LLE_IFADDR)) {
695		struct ifaddr *ifa;
696		struct in6_ifaddr *ia6;
697		int bad;
698
699		bad = 1;
700#define	sa_equal(a1, a2)						\
701	(bcmp((a1), (a2), ((a1))->sin6_len) == 0)
702		IF_ADDR_RLOCK(ifp);
703		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
704			if (ifa->ifa_addr->sa_family != dst6.sin6_family)
705				continue;
706			if (sa_equal(&dst6, ifa->ifa_addr))
707				break;
708		}
709		KASSERT(ifa != NULL, ("%s: ifa not found for lle %p",
710		    __func__, lle));
711#undef sa_equal
712
713		ia6 = (struct in6_ifaddr *)ifa;
714		if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
715			/* Count the packet in the ip address stats */
716			ia6->ia_ifa.if_ipackets++;
717			ia6->ia_ifa.if_ibytes += m->m_pkthdr.len;
718
719			/*
720			 * record address information into m_tag.
721			 */
722			(void)ip6_setdstifaddr(m, ia6);
723
724			bad = 0;
725		} else {
726			char ip6bufs[INET6_ADDRSTRLEN];
727			char ip6bufd[INET6_ADDRSTRLEN];
728			/* address is not ready, so discard the packet. */
729			nd6log((LOG_INFO,
730			    "ip6_input: packet to an unready address %s->%s\n",
731			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
732			    ip6_sprintf(ip6bufd, &ip6->ip6_dst)));
733		}
734		IF_ADDR_RUNLOCK(ifp);
735		LLE_RUNLOCK(lle);
736		if (bad)
737			goto bad;
738		else {
739			ours = 1;
740			deliverifp = ifp;
741			goto hbhcheck;
742		}
743	}
744	if (lle != NULL)
745		LLE_RUNLOCK(lle);
746
747	dst = &rin6.ro_dst;
748	dst->sin6_len = sizeof(struct sockaddr_in6);
749	dst->sin6_family = AF_INET6;
750	dst->sin6_addr = ip6->ip6_dst;
751	rin6.ro_rt = in6_rtalloc1((struct sockaddr *)dst, 0, 0, M_GETFIB(m));
752	if (rin6.ro_rt)
753		RT_UNLOCK(rin6.ro_rt);
754
755#define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key))
756
757	/*
758	 * Accept the packet if the forwarding interface to the destination
759	 * according to the routing table is the loopback interface,
760	 * unless the associated route has a gateway.
761	 * Note that this approach causes to accept a packet if there is a
762	 * route to the loopback interface for the destination of the packet.
763	 * But we think it's even useful in some situations, e.g. when using
764	 * a special daemon which wants to intercept the packet.
765	 *
766	 * XXX: some OSes automatically make a cloned route for the destination
767	 * of an outgoing packet.  If the outgoing interface of the packet
768	 * is a loopback one, the kernel would consider the packet to be
769	 * accepted, even if we have no such address assinged on the interface.
770	 * We check the cloned flag of the route entry to reject such cases,
771	 * assuming that route entries for our own addresses are not made by
772	 * cloning (it should be true because in6_addloop explicitly installs
773	 * the host route).  However, we might have to do an explicit check
774	 * while it would be less efficient.  Or, should we rather install a
775	 * reject route for such a case?
776	 */
777	if (rin6.ro_rt &&
778	    (rin6.ro_rt->rt_flags &
779	     (RTF_HOST|RTF_GATEWAY)) == RTF_HOST &&
780#ifdef RTF_WASCLONED
781	    !(rin6.ro_rt->rt_flags & RTF_WASCLONED) &&
782#endif
783#ifdef RTF_CLONED
784	    !(rin6.ro_rt->rt_flags & RTF_CLONED) &&
785#endif
786#if 0
787	    /*
788	     * The check below is redundant since the comparison of
789	     * the destination and the key of the rtentry has
790	     * already done through looking up the routing table.
791	     */
792	    IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
793	    &rt6_key(rin6.ro_rt)->sin6_addr)
794#endif
795	    rin6.ro_rt->rt_ifp->if_type == IFT_LOOP) {
796		int free_ia6 = 0;
797		struct in6_ifaddr *ia6;
798
799		/*
800		 * found the loopback route to the interface address
801		 */
802		if (rin6.ro_rt->rt_gateway->sa_family == AF_LINK) {
803			struct sockaddr_in6 dest6;
804
805			bzero(&dest6, sizeof(dest6));
806			dest6.sin6_family = AF_INET6;
807			dest6.sin6_len = sizeof(dest6);
808			dest6.sin6_addr = ip6->ip6_dst;
809			ia6 = (struct in6_ifaddr *)
810			    ifa_ifwithaddr((struct sockaddr *)&dest6);
811			if (ia6 == NULL)
812				goto bad;
813			free_ia6 = 1;
814		}
815		else
816			ia6 = (struct in6_ifaddr *)rin6.ro_rt->rt_ifa;
817
818		/*
819		 * record address information into m_tag.
820		 */
821		(void)ip6_setdstifaddr(m, ia6);
822
823		/*
824		 * packets to a tentative, duplicated, or somehow invalid
825		 * address must not be accepted.
826		 */
827		if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
828			/* this address is ready */
829			ours = 1;
830			deliverifp = ia6->ia_ifp;	/* correct? */
831			/* Count the packet in the ip address stats */
832			ia6->ia_ifa.if_ipackets++;
833			ia6->ia_ifa.if_ibytes += m->m_pkthdr.len;
834			if (ia6 != NULL && free_ia6 != 0)
835				ifa_free(&ia6->ia_ifa);
836			goto hbhcheck;
837		} else {
838			char ip6bufs[INET6_ADDRSTRLEN];
839			char ip6bufd[INET6_ADDRSTRLEN];
840			/* address is not ready, so discard the packet. */
841			nd6log((LOG_INFO,
842			    "ip6_input: packet to an unready address %s->%s\n",
843			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
844			    ip6_sprintf(ip6bufd, &ip6->ip6_dst)));
845
846			if (ia6 != NULL && free_ia6 != 0)
847				ifa_free(&ia6->ia_ifa);
848			goto bad;
849		}
850	}
851
852	/*
853	 * FAITH (Firewall Aided Internet Translator)
854	 */
855	if (V_ip6_keepfaith) {
856		if (rin6.ro_rt && rin6.ro_rt->rt_ifp &&
857		    rin6.ro_rt->rt_ifp->if_type == IFT_FAITH) {
858			/* XXX do we need more sanity checks? */
859			ours = 1;
860			deliverifp = rin6.ro_rt->rt_ifp; /* faith */
861			goto hbhcheck;
862		}
863	}
864
865	/*
866	 * Now there is no reason to process the packet if it's not our own
867	 * and we're not a router.
868	 */
869	if (!V_ip6_forwarding) {
870		V_ip6stat.ip6s_cantforward++;
871		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
872		goto bad;
873	}
874
875  hbhcheck:
876	/*
877	 * record address information into m_tag, if we don't have one yet.
878	 * note that we are unable to record it, if the address is not listed
879	 * as our interface address (e.g. multicast addresses, addresses
880	 * within FAITH prefixes and such).
881	 */
882	if (deliverifp) {
883		struct in6_ifaddr *ia6;
884
885 		if ((ia6 = ip6_getdstifaddr(m)) != NULL) {
886			ifa_free(&ia6->ia_ifa);
887		} else {
888			ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst);
889			if (ia6) {
890				if (!ip6_setdstifaddr(m, ia6)) {
891					/*
892					 * XXX maybe we should drop the packet here,
893					 * as we could not provide enough information
894					 * to the upper layers.
895					 */
896				}
897				ifa_free(&ia6->ia_ifa);
898			}
899		}
900	}
901
902	/*
903	 * Process Hop-by-Hop options header if it's contained.
904	 * m may be modified in ip6_hopopts_input().
905	 * If a JumboPayload option is included, plen will also be modified.
906	 */
907	plen = (u_int32_t)ntohs(ip6->ip6_plen);
908	if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
909		int error;
910
911		error = ip6_input_hbh(m, &plen, &rtalert, &off, &nxt, &ours);
912		if (error != 0)
913			goto out;
914	} else
915		nxt = ip6->ip6_nxt;
916
917	/*
918	 * Check that the amount of data in the buffers
919	 * is as at least much as the IPv6 header would have us expect.
920	 * Trim mbufs if longer than we expect.
921	 * Drop packet if shorter than we expect.
922	 */
923	if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
924		V_ip6stat.ip6s_tooshort++;
925		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
926		goto bad;
927	}
928	if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
929		if (m->m_len == m->m_pkthdr.len) {
930			m->m_len = sizeof(struct ip6_hdr) + plen;
931			m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen;
932		} else
933			m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len);
934	}
935
936	/*
937	 * Forward if desirable.
938	 */
939	if (V_ip6_mrouter &&
940	    IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
941		/*
942		 * If we are acting as a multicast router, all
943		 * incoming multicast packets are passed to the
944		 * kernel-level multicast forwarding function.
945		 * The packet is returned (relatively) intact; if
946		 * ip6_mforward() returns a non-zero value, the packet
947		 * must be discarded, else it may be accepted below.
948		 *
949		 * XXX TODO: Check hlim and multicast scope here to avoid
950		 * unnecessarily calling into ip6_mforward().
951		 */
952		if (ip6_mforward &&
953		    ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) {
954			IP6STAT_INC(ip6s_cantforward);
955			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
956			goto bad;
957		}
958	} else if (!ours) {
959		ip6_forward(m, srcrt);
960		goto out;
961	}
962
963	ip6 = mtod(m, struct ip6_hdr *);
964
965	/*
966	 * Malicious party may be able to use IPv4 mapped addr to confuse
967	 * tcp/udp stack and bypass security checks (act as if it was from
968	 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1).  Be cautious.
969	 *
970	 * For SIIT end node behavior, you may want to disable the check.
971	 * However, you will  become vulnerable to attacks using IPv4 mapped
972	 * source.
973	 */
974	if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
975	    IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
976		V_ip6stat.ip6s_badscope++;
977		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
978		goto bad;
979	}
980
981	/*
982	 * Tell launch routine the next header
983	 */
984	V_ip6stat.ip6s_delivered++;
985	in6_ifstat_inc(deliverifp, ifs6_in_deliver);
986	nest = 0;
987
988	while (nxt != IPPROTO_DONE) {
989		if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) {
990			V_ip6stat.ip6s_toomanyhdr++;
991			goto bad;
992		}
993
994		/*
995		 * protection against faulty packet - there should be
996		 * more sanity checks in header chain processing.
997		 */
998		if (m->m_pkthdr.len < off) {
999			V_ip6stat.ip6s_tooshort++;
1000			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
1001			goto bad;
1002		}
1003
1004#ifdef IPSEC
1005		/*
1006		 * enforce IPsec policy checking if we are seeing last header.
1007		 * note that we do not visit this with protocols with pcb layer
1008		 * code - like udp/tcp/raw ip.
1009		 */
1010		if (ip6_ipsec_input(m, nxt))
1011			goto bad;
1012#endif /* IPSEC */
1013
1014		/*
1015		 * Use mbuf flags to propagate Router Alert option to
1016		 * ICMPv6 layer, as hop-by-hop options have been stripped.
1017		 */
1018		if (nxt == IPPROTO_ICMPV6 && rtalert != ~0)
1019			m->m_flags |= M_RTALERT_MLD;
1020
1021		nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt);
1022	}
1023	goto out;
1024bad:
1025	m_freem(m);
1026out:
1027	if (rin6.ro_rt)
1028		RTFREE(rin6.ro_rt);
1029}
1030
1031/*
1032 * set/grab in6_ifaddr correspond to IPv6 destination address.
1033 * XXX backward compatibility wrapper
1034 *
1035 * XXXRW: We should bump the refcount on ia6 before sticking it in the m_tag,
1036 * and then bump it when the tag is copied, and release it when the tag is
1037 * freed.  Unfortunately, m_tags don't support deep copies (yet), so instead
1038 * we just bump the ia refcount when we receive it.  This should be fixed.
1039 */
1040static struct ip6aux *
1041ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6)
1042{
1043	struct ip6aux *ip6a;
1044
1045	ip6a = ip6_addaux(m);
1046	if (ip6a)
1047		ip6a->ip6a_dstia6 = ia6;
1048	return ip6a;	/* NULL if failed to set */
1049}
1050
1051struct in6_ifaddr *
1052ip6_getdstifaddr(struct mbuf *m)
1053{
1054	struct ip6aux *ip6a;
1055	struct in6_ifaddr *ia;
1056
1057	ip6a = ip6_findaux(m);
1058	if (ip6a) {
1059		ia = ip6a->ip6a_dstia6;
1060		ifa_ref(&ia->ia_ifa);
1061		return ia;
1062	} else
1063		return NULL;
1064}
1065
1066/*
1067 * Hop-by-Hop options header processing. If a valid jumbo payload option is
1068 * included, the real payload length will be stored in plenp.
1069 *
1070 * rtalertp - XXX: should be stored more smart way
1071 */
1072static int
1073ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp,
1074    struct mbuf **mp, int *offp)
1075{
1076	struct mbuf *m = *mp;
1077	int off = *offp, hbhlen;
1078	struct ip6_hbh *hbh;
1079	u_int8_t *opt;
1080
1081	/* validation of the length of the header */
1082#ifndef PULLDOWN_TEST
1083	IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1);
1084	hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
1085	hbhlen = (hbh->ip6h_len + 1) << 3;
1086
1087	IP6_EXTHDR_CHECK(m, off, hbhlen, -1);
1088	hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
1089#else
1090	IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
1091		sizeof(struct ip6_hdr), sizeof(struct ip6_hbh));
1092	if (hbh == NULL) {
1093		V_ip6stat.ip6s_tooshort++;
1094		return -1;
1095	}
1096	hbhlen = (hbh->ip6h_len + 1) << 3;
1097	IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
1098		hbhlen);
1099	if (hbh == NULL) {
1100		V_ip6stat.ip6s_tooshort++;
1101		return -1;
1102	}
1103#endif
1104	off += hbhlen;
1105	hbhlen -= sizeof(struct ip6_hbh);
1106	opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh);
1107
1108	if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh),
1109				hbhlen, rtalertp, plenp) < 0)
1110		return (-1);
1111
1112	*offp = off;
1113	*mp = m;
1114	return (0);
1115}
1116
1117/*
1118 * Search header for all Hop-by-hop options and process each option.
1119 * This function is separate from ip6_hopopts_input() in order to
1120 * handle a case where the sending node itself process its hop-by-hop
1121 * options header. In such a case, the function is called from ip6_output().
1122 *
1123 * The function assumes that hbh header is located right after the IPv6 header
1124 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to
1125 * opthead + hbhlen is located in contiguous memory region.
1126 */
1127int
1128ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen,
1129    u_int32_t *rtalertp, u_int32_t *plenp)
1130{
1131	struct ip6_hdr *ip6;
1132	int optlen = 0;
1133	u_int8_t *opt = opthead;
1134	u_int16_t rtalert_val;
1135	u_int32_t jumboplen;
1136	const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh);
1137
1138	for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
1139		switch (*opt) {
1140		case IP6OPT_PAD1:
1141			optlen = 1;
1142			break;
1143		case IP6OPT_PADN:
1144			if (hbhlen < IP6OPT_MINLEN) {
1145				V_ip6stat.ip6s_toosmall++;
1146				goto bad;
1147			}
1148			optlen = *(opt + 1) + 2;
1149			break;
1150		case IP6OPT_ROUTER_ALERT:
1151			/* XXX may need check for alignment */
1152			if (hbhlen < IP6OPT_RTALERT_LEN) {
1153				V_ip6stat.ip6s_toosmall++;
1154				goto bad;
1155			}
1156			if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
1157				/* XXX stat */
1158				icmp6_error(m, ICMP6_PARAM_PROB,
1159				    ICMP6_PARAMPROB_HEADER,
1160				    erroff + opt + 1 - opthead);
1161				return (-1);
1162			}
1163			optlen = IP6OPT_RTALERT_LEN;
1164			bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2);
1165			*rtalertp = ntohs(rtalert_val);
1166			break;
1167		case IP6OPT_JUMBO:
1168			/* XXX may need check for alignment */
1169			if (hbhlen < IP6OPT_JUMBO_LEN) {
1170				V_ip6stat.ip6s_toosmall++;
1171				goto bad;
1172			}
1173			if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
1174				/* XXX stat */
1175				icmp6_error(m, ICMP6_PARAM_PROB,
1176				    ICMP6_PARAMPROB_HEADER,
1177				    erroff + opt + 1 - opthead);
1178				return (-1);
1179			}
1180			optlen = IP6OPT_JUMBO_LEN;
1181
1182			/*
1183			 * IPv6 packets that have non 0 payload length
1184			 * must not contain a jumbo payload option.
1185			 */
1186			ip6 = mtod(m, struct ip6_hdr *);
1187			if (ip6->ip6_plen) {
1188				V_ip6stat.ip6s_badoptions++;
1189				icmp6_error(m, ICMP6_PARAM_PROB,
1190				    ICMP6_PARAMPROB_HEADER,
1191				    erroff + opt - opthead);
1192				return (-1);
1193			}
1194
1195			/*
1196			 * We may see jumbolen in unaligned location, so
1197			 * we'd need to perform bcopy().
1198			 */
1199			bcopy(opt + 2, &jumboplen, sizeof(jumboplen));
1200			jumboplen = (u_int32_t)htonl(jumboplen);
1201
1202#if 1
1203			/*
1204			 * if there are multiple jumbo payload options,
1205			 * *plenp will be non-zero and the packet will be
1206			 * rejected.
1207			 * the behavior may need some debate in ipngwg -
1208			 * multiple options does not make sense, however,
1209			 * there's no explicit mention in specification.
1210			 */
1211			if (*plenp != 0) {
1212				V_ip6stat.ip6s_badoptions++;
1213				icmp6_error(m, ICMP6_PARAM_PROB,
1214				    ICMP6_PARAMPROB_HEADER,
1215				    erroff + opt + 2 - opthead);
1216				return (-1);
1217			}
1218#endif
1219
1220			/*
1221			 * jumbo payload length must be larger than 65535.
1222			 */
1223			if (jumboplen <= IPV6_MAXPACKET) {
1224				V_ip6stat.ip6s_badoptions++;
1225				icmp6_error(m, ICMP6_PARAM_PROB,
1226				    ICMP6_PARAMPROB_HEADER,
1227				    erroff + opt + 2 - opthead);
1228				return (-1);
1229			}
1230			*plenp = jumboplen;
1231
1232			break;
1233		default:		/* unknown option */
1234			if (hbhlen < IP6OPT_MINLEN) {
1235				V_ip6stat.ip6s_toosmall++;
1236				goto bad;
1237			}
1238			optlen = ip6_unknown_opt(opt, m,
1239			    erroff + opt - opthead);
1240			if (optlen == -1)
1241				return (-1);
1242			optlen += 2;
1243			break;
1244		}
1245	}
1246
1247	return (0);
1248
1249  bad:
1250	m_freem(m);
1251	return (-1);
1252}
1253
1254/*
1255 * Unknown option processing.
1256 * The third argument `off' is the offset from the IPv6 header to the option,
1257 * which is necessary if the IPv6 header the and option header and IPv6 header
1258 * is not contiguous in order to return an ICMPv6 error.
1259 */
1260int
1261ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off)
1262{
1263	struct ip6_hdr *ip6;
1264
1265	switch (IP6OPT_TYPE(*optp)) {
1266	case IP6OPT_TYPE_SKIP: /* ignore the option */
1267		return ((int)*(optp + 1));
1268	case IP6OPT_TYPE_DISCARD:	/* silently discard */
1269		m_freem(m);
1270		return (-1);
1271	case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */
1272		V_ip6stat.ip6s_badoptions++;
1273		icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
1274		return (-1);
1275	case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
1276		V_ip6stat.ip6s_badoptions++;
1277		ip6 = mtod(m, struct ip6_hdr *);
1278		if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
1279		    (m->m_flags & (M_BCAST|M_MCAST)))
1280			m_freem(m);
1281		else
1282			icmp6_error(m, ICMP6_PARAM_PROB,
1283				    ICMP6_PARAMPROB_OPTION, off);
1284		return (-1);
1285	}
1286
1287	m_freem(m);		/* XXX: NOTREACHED */
1288	return (-1);
1289}
1290
1291/*
1292 * Create the "control" list for this pcb.
1293 * These functions will not modify mbuf chain at all.
1294 *
1295 * With KAME mbuf chain restriction:
1296 * The routine will be called from upper layer handlers like tcp6_input().
1297 * Thus the routine assumes that the caller (tcp6_input) have already
1298 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the
1299 * very first mbuf on the mbuf chain.
1300 *
1301 * ip6_savecontrol_v4 will handle those options that are possible to be
1302 * set on a v4-mapped socket.
1303 * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those
1304 * options and handle the v6-only ones itself.
1305 */
1306struct mbuf **
1307ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp,
1308    int *v4only)
1309{
1310	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1311
1312#ifdef SO_TIMESTAMP
1313	if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) {
1314		struct timeval tv;
1315
1316		microtime(&tv);
1317		*mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1318		    SCM_TIMESTAMP, SOL_SOCKET);
1319		if (*mp)
1320			mp = &(*mp)->m_next;
1321	}
1322#endif
1323
1324#define IS2292(inp, x, y)	(((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y))
1325	/* RFC 2292 sec. 5 */
1326	if ((inp->inp_flags & IN6P_PKTINFO) != 0) {
1327		struct in6_pktinfo pi6;
1328
1329		if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1330#ifdef INET
1331			struct ip *ip;
1332
1333			ip = mtod(m, struct ip *);
1334			pi6.ipi6_addr.s6_addr32[0] = 0;
1335			pi6.ipi6_addr.s6_addr32[1] = 0;
1336			pi6.ipi6_addr.s6_addr32[2] = IPV6_ADDR_INT32_SMP;
1337			pi6.ipi6_addr.s6_addr32[3] = ip->ip_dst.s_addr;
1338#else
1339			/* We won't hit this code */
1340			bzero(&pi6.ipi6_addr, sizeof(struct in6_addr));
1341#endif
1342		} else {
1343			bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr));
1344			in6_clearscope(&pi6.ipi6_addr);	/* XXX */
1345		}
1346		pi6.ipi6_ifindex =
1347		    (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0;
1348
1349		*mp = sbcreatecontrol((caddr_t) &pi6,
1350		    sizeof(struct in6_pktinfo),
1351		    IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6);
1352		if (*mp)
1353			mp = &(*mp)->m_next;
1354	}
1355
1356	if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) {
1357		int hlim;
1358
1359		if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1360#ifdef INET
1361			struct ip *ip;
1362
1363			ip = mtod(m, struct ip *);
1364			hlim = ip->ip_ttl;
1365#else
1366			/* We won't hit this code */
1367			hlim = 0;
1368#endif
1369		} else {
1370			hlim = ip6->ip6_hlim & 0xff;
1371		}
1372		*mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int),
1373		    IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT),
1374		    IPPROTO_IPV6);
1375		if (*mp)
1376			mp = &(*mp)->m_next;
1377	}
1378
1379	if ((inp->inp_flags & IN6P_TCLASS) != 0) {
1380		int tclass;
1381
1382		if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1383#ifdef INET
1384			struct ip *ip;
1385
1386			ip = mtod(m, struct ip *);
1387			tclass = ip->ip_tos;
1388#else
1389			/* We won't hit this code */
1390			tclass = 0;
1391#endif
1392		} else {
1393			u_int32_t flowinfo;
1394
1395			flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK);
1396			flowinfo >>= 20;
1397			tclass = flowinfo & 0xff;
1398		}
1399		*mp = sbcreatecontrol((caddr_t) &tclass, sizeof(int),
1400		    IPV6_TCLASS, IPPROTO_IPV6);
1401		if (*mp)
1402			mp = &(*mp)->m_next;
1403	}
1404
1405	if (v4only != NULL) {
1406		if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1407			*v4only = 1;
1408		} else {
1409			*v4only = 0;
1410		}
1411	}
1412
1413	return (mp);
1414}
1415
1416void
1417ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp)
1418{
1419	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1420	int v4only = 0;
1421
1422	mp = ip6_savecontrol_v4(in6p, m, mp, &v4only);
1423	if (v4only)
1424		return;
1425
1426	/*
1427	 * IPV6_HOPOPTS socket option.  Recall that we required super-user
1428	 * privilege for the option (see ip6_ctloutput), but it might be too
1429	 * strict, since there might be some hop-by-hop options which can be
1430	 * returned to normal user.
1431	 * See also RFC 2292 section 6 (or RFC 3542 section 8).
1432	 */
1433	if ((in6p->inp_flags & IN6P_HOPOPTS) != 0) {
1434		/*
1435		 * Check if a hop-by-hop options header is contatined in the
1436		 * received packet, and if so, store the options as ancillary
1437		 * data. Note that a hop-by-hop options header must be
1438		 * just after the IPv6 header, which is assured through the
1439		 * IPv6 input processing.
1440		 */
1441		if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
1442			struct ip6_hbh *hbh;
1443			int hbhlen = 0;
1444#ifdef PULLDOWN_TEST
1445			struct mbuf *ext;
1446#endif
1447
1448#ifndef PULLDOWN_TEST
1449			hbh = (struct ip6_hbh *)(ip6 + 1);
1450			hbhlen = (hbh->ip6h_len + 1) << 3;
1451#else
1452			ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr),
1453			    ip6->ip6_nxt);
1454			if (ext == NULL) {
1455				V_ip6stat.ip6s_tooshort++;
1456				return;
1457			}
1458			hbh = mtod(ext, struct ip6_hbh *);
1459			hbhlen = (hbh->ip6h_len + 1) << 3;
1460			if (hbhlen != ext->m_len) {
1461				m_freem(ext);
1462				V_ip6stat.ip6s_tooshort++;
1463				return;
1464			}
1465#endif
1466
1467			/*
1468			 * XXX: We copy the whole header even if a
1469			 * jumbo payload option is included, the option which
1470			 * is to be removed before returning according to
1471			 * RFC2292.
1472			 * Note: this constraint is removed in RFC3542
1473			 */
1474			*mp = sbcreatecontrol((caddr_t)hbh, hbhlen,
1475			    IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS),
1476			    IPPROTO_IPV6);
1477			if (*mp)
1478				mp = &(*mp)->m_next;
1479#ifdef PULLDOWN_TEST
1480			m_freem(ext);
1481#endif
1482		}
1483	}
1484
1485	if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) {
1486		int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);
1487
1488		/*
1489		 * Search for destination options headers or routing
1490		 * header(s) through the header chain, and stores each
1491		 * header as ancillary data.
1492		 * Note that the order of the headers remains in
1493		 * the chain of ancillary data.
1494		 */
1495		while (1) {	/* is explicit loop prevention necessary? */
1496			struct ip6_ext *ip6e = NULL;
1497			int elen;
1498#ifdef PULLDOWN_TEST
1499			struct mbuf *ext = NULL;
1500#endif
1501
1502			/*
1503			 * if it is not an extension header, don't try to
1504			 * pull it from the chain.
1505			 */
1506			switch (nxt) {
1507			case IPPROTO_DSTOPTS:
1508			case IPPROTO_ROUTING:
1509			case IPPROTO_HOPOPTS:
1510			case IPPROTO_AH: /* is it possible? */
1511				break;
1512			default:
1513				goto loopend;
1514			}
1515
1516#ifndef PULLDOWN_TEST
1517			if (off + sizeof(*ip6e) > m->m_len)
1518				goto loopend;
1519			ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
1520			if (nxt == IPPROTO_AH)
1521				elen = (ip6e->ip6e_len + 2) << 2;
1522			else
1523				elen = (ip6e->ip6e_len + 1) << 3;
1524			if (off + elen > m->m_len)
1525				goto loopend;
1526#else
1527			ext = ip6_pullexthdr(m, off, nxt);
1528			if (ext == NULL) {
1529				V_ip6stat.ip6s_tooshort++;
1530				return;
1531			}
1532			ip6e = mtod(ext, struct ip6_ext *);
1533			if (nxt == IPPROTO_AH)
1534				elen = (ip6e->ip6e_len + 2) << 2;
1535			else
1536				elen = (ip6e->ip6e_len + 1) << 3;
1537			if (elen != ext->m_len) {
1538				m_freem(ext);
1539				V_ip6stat.ip6s_tooshort++;
1540				return;
1541			}
1542#endif
1543
1544			switch (nxt) {
1545			case IPPROTO_DSTOPTS:
1546				if (!(in6p->inp_flags & IN6P_DSTOPTS))
1547					break;
1548
1549				*mp = sbcreatecontrol((caddr_t)ip6e, elen,
1550				    IS2292(in6p,
1551					IPV6_2292DSTOPTS, IPV6_DSTOPTS),
1552				    IPPROTO_IPV6);
1553				if (*mp)
1554					mp = &(*mp)->m_next;
1555				break;
1556			case IPPROTO_ROUTING:
1557				if (!(in6p->inp_flags & IN6P_RTHDR))
1558					break;
1559
1560				*mp = sbcreatecontrol((caddr_t)ip6e, elen,
1561				    IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR),
1562				    IPPROTO_IPV6);
1563				if (*mp)
1564					mp = &(*mp)->m_next;
1565				break;
1566			case IPPROTO_HOPOPTS:
1567			case IPPROTO_AH: /* is it possible? */
1568				break;
1569
1570			default:
1571				/*
1572				 * other cases have been filtered in the above.
1573				 * none will visit this case.  here we supply
1574				 * the code just in case (nxt overwritten or
1575				 * other cases).
1576				 */
1577#ifdef PULLDOWN_TEST
1578				m_freem(ext);
1579#endif
1580				goto loopend;
1581
1582			}
1583
1584			/* proceed with the next header. */
1585			off += elen;
1586			nxt = ip6e->ip6e_nxt;
1587			ip6e = NULL;
1588#ifdef PULLDOWN_TEST
1589			m_freem(ext);
1590			ext = NULL;
1591#endif
1592		}
1593	  loopend:
1594		;
1595	}
1596}
1597#undef IS2292
1598
1599void
1600ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu)
1601{
1602	struct socket *so;
1603	struct mbuf *m_mtu;
1604	struct ip6_mtuinfo mtuctl;
1605
1606	so =  in6p->inp_socket;
1607
1608	if (mtu == NULL)
1609		return;
1610
1611#ifdef DIAGNOSTIC
1612	if (so == NULL)		/* I believe this is impossible */
1613		panic("ip6_notify_pmtu: socket is NULL");
1614#endif
1615
1616	bzero(&mtuctl, sizeof(mtuctl));	/* zero-clear for safety */
1617	mtuctl.ip6m_mtu = *mtu;
1618	mtuctl.ip6m_addr = *dst;
1619	if (sa6_recoverscope(&mtuctl.ip6m_addr))
1620		return;
1621
1622	if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl),
1623	    IPV6_PATHMTU, IPPROTO_IPV6)) == NULL)
1624		return;
1625
1626	if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu)
1627	    == 0) {
1628		m_freem(m_mtu);
1629		/* XXX: should count statistics */
1630	} else
1631		sorwakeup(so);
1632
1633	return;
1634}
1635
1636#ifdef PULLDOWN_TEST
1637/*
1638 * pull single extension header from mbuf chain.  returns single mbuf that
1639 * contains the result, or NULL on error.
1640 */
1641static struct mbuf *
1642ip6_pullexthdr(struct mbuf *m, size_t off, int nxt)
1643{
1644	struct ip6_ext ip6e;
1645	size_t elen;
1646	struct mbuf *n;
1647
1648#ifdef DIAGNOSTIC
1649	switch (nxt) {
1650	case IPPROTO_DSTOPTS:
1651	case IPPROTO_ROUTING:
1652	case IPPROTO_HOPOPTS:
1653	case IPPROTO_AH: /* is it possible? */
1654		break;
1655	default:
1656		printf("ip6_pullexthdr: invalid nxt=%d\n", nxt);
1657	}
1658#endif
1659
1660	m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1661	if (nxt == IPPROTO_AH)
1662		elen = (ip6e.ip6e_len + 2) << 2;
1663	else
1664		elen = (ip6e.ip6e_len + 1) << 3;
1665
1666	MGET(n, M_DONTWAIT, MT_DATA);
1667	if (n && elen >= MLEN) {
1668		MCLGET(n, M_DONTWAIT);
1669		if ((n->m_flags & M_EXT) == 0) {
1670			m_free(n);
1671			n = NULL;
1672		}
1673	}
1674	if (!n)
1675		return NULL;
1676
1677	n->m_len = 0;
1678	if (elen >= M_TRAILINGSPACE(n)) {
1679		m_free(n);
1680		return NULL;
1681	}
1682
1683	m_copydata(m, off, elen, mtod(n, caddr_t));
1684	n->m_len = elen;
1685	return n;
1686}
1687#endif
1688
1689/*
1690 * Get pointer to the previous header followed by the header
1691 * currently processed.
1692 * XXX: This function supposes that
1693 *	M includes all headers,
1694 *	the next header field and the header length field of each header
1695 *	are valid, and
1696 *	the sum of each header length equals to OFF.
1697 * Because of these assumptions, this function must be called very
1698 * carefully. Moreover, it will not be used in the near future when
1699 * we develop `neater' mechanism to process extension headers.
1700 */
1701char *
1702ip6_get_prevhdr(struct mbuf *m, int off)
1703{
1704	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1705
1706	if (off == sizeof(struct ip6_hdr))
1707		return (&ip6->ip6_nxt);
1708	else {
1709		int len, nxt;
1710		struct ip6_ext *ip6e = NULL;
1711
1712		nxt = ip6->ip6_nxt;
1713		len = sizeof(struct ip6_hdr);
1714		while (len < off) {
1715			ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len);
1716
1717			switch (nxt) {
1718			case IPPROTO_FRAGMENT:
1719				len += sizeof(struct ip6_frag);
1720				break;
1721			case IPPROTO_AH:
1722				len += (ip6e->ip6e_len + 2) << 2;
1723				break;
1724			default:
1725				len += (ip6e->ip6e_len + 1) << 3;
1726				break;
1727			}
1728			nxt = ip6e->ip6e_nxt;
1729		}
1730		if (ip6e)
1731			return (&ip6e->ip6e_nxt);
1732		else
1733			return NULL;
1734	}
1735}
1736
1737/*
1738 * get next header offset.  m will be retained.
1739 */
1740int
1741ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp)
1742{
1743	struct ip6_hdr ip6;
1744	struct ip6_ext ip6e;
1745	struct ip6_frag fh;
1746
1747	/* just in case */
1748	if (m == NULL)
1749		panic("ip6_nexthdr: m == NULL");
1750	if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off)
1751		return -1;
1752
1753	switch (proto) {
1754	case IPPROTO_IPV6:
1755		if (m->m_pkthdr.len < off + sizeof(ip6))
1756			return -1;
1757		m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6);
1758		if (nxtp)
1759			*nxtp = ip6.ip6_nxt;
1760		off += sizeof(ip6);
1761		return off;
1762
1763	case IPPROTO_FRAGMENT:
1764		/*
1765		 * terminate parsing if it is not the first fragment,
1766		 * it does not make sense to parse through it.
1767		 */
1768		if (m->m_pkthdr.len < off + sizeof(fh))
1769			return -1;
1770		m_copydata(m, off, sizeof(fh), (caddr_t)&fh);
1771		/* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */
1772		if (fh.ip6f_offlg & IP6F_OFF_MASK)
1773			return -1;
1774		if (nxtp)
1775			*nxtp = fh.ip6f_nxt;
1776		off += sizeof(struct ip6_frag);
1777		return off;
1778
1779	case IPPROTO_AH:
1780		if (m->m_pkthdr.len < off + sizeof(ip6e))
1781			return -1;
1782		m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1783		if (nxtp)
1784			*nxtp = ip6e.ip6e_nxt;
1785		off += (ip6e.ip6e_len + 2) << 2;
1786		return off;
1787
1788	case IPPROTO_HOPOPTS:
1789	case IPPROTO_ROUTING:
1790	case IPPROTO_DSTOPTS:
1791		if (m->m_pkthdr.len < off + sizeof(ip6e))
1792			return -1;
1793		m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1794		if (nxtp)
1795			*nxtp = ip6e.ip6e_nxt;
1796		off += (ip6e.ip6e_len + 1) << 3;
1797		return off;
1798
1799	case IPPROTO_NONE:
1800	case IPPROTO_ESP:
1801	case IPPROTO_IPCOMP:
1802		/* give up */
1803		return -1;
1804
1805	default:
1806		return -1;
1807	}
1808
1809	return -1;
1810}
1811
1812/*
1813 * get offset for the last header in the chain.  m will be kept untainted.
1814 */
1815int
1816ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp)
1817{
1818	int newoff;
1819	int nxt;
1820
1821	if (!nxtp) {
1822		nxt = -1;
1823		nxtp = &nxt;
1824	}
1825	while (1) {
1826		newoff = ip6_nexthdr(m, off, proto, nxtp);
1827		if (newoff < 0)
1828			return off;
1829		else if (newoff < off)
1830			return -1;	/* invalid */
1831		else if (newoff == off)
1832			return newoff;
1833
1834		off = newoff;
1835		proto = *nxtp;
1836	}
1837}
1838
1839static struct ip6aux *
1840ip6_addaux(struct mbuf *m)
1841{
1842	struct m_tag *mtag;
1843
1844	mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1845	if (!mtag) {
1846		mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux),
1847		    M_NOWAIT);
1848		if (mtag) {
1849			m_tag_prepend(m, mtag);
1850			bzero(mtag + 1, sizeof(struct ip6aux));
1851		}
1852	}
1853	return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
1854}
1855
1856static struct ip6aux *
1857ip6_findaux(struct mbuf *m)
1858{
1859	struct m_tag *mtag;
1860
1861	mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1862	return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
1863}
1864
1865static void
1866ip6_delaux(struct mbuf *m)
1867{
1868	struct m_tag *mtag;
1869
1870	mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1871	if (mtag)
1872		m_tag_delete(m, mtag);
1873}
1874
1875/*
1876 * System control for IP6
1877 */
1878
1879u_char	inet6ctlerrmap[PRC_NCMDS] = {
1880	0,		0,		0,		0,
1881	0,		EMSGSIZE,	EHOSTDOWN,	EHOSTUNREACH,
1882	EHOSTUNREACH,	EHOSTUNREACH,	ECONNREFUSED,	ECONNREFUSED,
1883	EMSGSIZE,	EHOSTUNREACH,	0,		0,
1884	0,		0,		0,		0,
1885	ENOPROTOOPT
1886};
1887