xref: /freebsd/sys/netinet6/ip6_input.c (revision e7d02be19d40063783d6b8f1ff2bc4c7170fd434)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the project nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	$KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $
32  */
33 
34 /*-
35  * Copyright (c) 1982, 1986, 1988, 1993
36  *	The Regents of the University of California.  All rights reserved.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 3. Neither the name of the University nor the names of its contributors
47  *    may be used to endorse or promote products derived from this software
48  *    without specific prior written permission.
49  *
50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60  * SUCH DAMAGE.
61  *
62  *	@(#)ip_input.c	8.2 (Berkeley) 1/4/94
63  */
64 
65 #include <sys/cdefs.h>
66 __FBSDID("$FreeBSD$");
67 
68 #include "opt_inet.h"
69 #include "opt_inet6.h"
70 #include "opt_ipsec.h"
71 #include "opt_route.h"
72 #include "opt_rss.h"
73 #include "opt_sctp.h"
74 
75 #include <sys/param.h>
76 #include <sys/systm.h>
77 #include <sys/hhook.h>
78 #include <sys/malloc.h>
79 #include <sys/mbuf.h>
80 #include <sys/proc.h>
81 #include <sys/domain.h>
82 #include <sys/protosw.h>
83 #include <sys/sdt.h>
84 #include <sys/socket.h>
85 #include <sys/socketvar.h>
86 #include <sys/errno.h>
87 #include <sys/time.h>
88 #include <sys/kernel.h>
89 #include <sys/lock.h>
90 #include <sys/rmlock.h>
91 #include <sys/syslog.h>
92 #include <sys/sysctl.h>
93 
94 #include <net/if.h>
95 #include <net/if_var.h>
96 #include <net/if_types.h>
97 #include <net/if_dl.h>
98 #include <net/route.h>
99 #include <net/netisr.h>
100 #include <net/rss_config.h>
101 #include <net/pfil.h>
102 #include <net/vnet.h>
103 
104 #include <netinet/in.h>
105 #include <netinet/in_kdtrace.h>
106 #include <netinet/ip_var.h>
107 #include <netinet/in_systm.h>
108 #include <net/if_llatbl.h>
109 #ifdef INET
110 #include <netinet/ip.h>
111 #include <netinet/ip_icmp.h>
112 #endif /* INET */
113 #include <netinet/ip6.h>
114 #include <netinet6/in6_var.h>
115 #include <netinet6/ip6_var.h>
116 #include <netinet/ip_encap.h>
117 #include <netinet/in_pcb.h>
118 #include <netinet/icmp6.h>
119 #include <netinet6/scope6_var.h>
120 #include <netinet6/in6_ifattach.h>
121 #include <netinet6/mld6_var.h>
122 #include <netinet6/nd6.h>
123 #include <netinet6/in6_rss.h>
124 #ifdef SCTP
125 #include <netinet/sctp_pcb.h>
126 #include <netinet6/sctp6_var.h>
127 #endif
128 
129 #include <netipsec/ipsec_support.h>
130 
131 #include <netinet6/ip6protosw.h>
132 
133 ipproto_input_t		*ip6_protox[IPPROTO_MAX] = {
134 			    [0 ... IPPROTO_MAX - 1] = rip6_input };
135 ipproto_ctlinput_t	*ip6_ctlprotox[IPPROTO_MAX] = {
136 			    [0 ... IPPROTO_MAX - 1] = rip6_ctlinput };
137 
138 VNET_DEFINE(struct in6_ifaddrhead, in6_ifaddrhead);
139 VNET_DEFINE(struct in6_ifaddrlisthead *, in6_ifaddrhashtbl);
140 VNET_DEFINE(u_long, in6_ifaddrhmask);
141 
142 static struct netisr_handler ip6_nh = {
143 	.nh_name = "ip6",
144 	.nh_handler = ip6_input,
145 	.nh_proto = NETISR_IPV6,
146 #ifdef RSS
147 	.nh_m2cpuid = rss_soft_m2cpuid_v6,
148 	.nh_policy = NETISR_POLICY_CPU,
149 	.nh_dispatch = NETISR_DISPATCH_HYBRID,
150 #else
151 	.nh_policy = NETISR_POLICY_FLOW,
152 #endif
153 };
154 
155 static int
156 sysctl_netinet6_intr_queue_maxlen(SYSCTL_HANDLER_ARGS)
157 {
158 	int error, qlimit;
159 
160 	netisr_getqlimit(&ip6_nh, &qlimit);
161 	error = sysctl_handle_int(oidp, &qlimit, 0, req);
162 	if (error || !req->newptr)
163 		return (error);
164 	if (qlimit < 1)
165 		return (EINVAL);
166 	return (netisr_setqlimit(&ip6_nh, qlimit));
167 }
168 SYSCTL_DECL(_net_inet6_ip6);
169 SYSCTL_PROC(_net_inet6_ip6, IPV6CTL_INTRQMAXLEN, intr_queue_maxlen,
170     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
171     0, 0, sysctl_netinet6_intr_queue_maxlen, "I",
172     "Maximum size of the IPv6 input queue");
173 
174 VNET_DEFINE_STATIC(bool, ip6_sav) = true;
175 #define	V_ip6_sav	VNET(ip6_sav)
176 SYSCTL_BOOL(_net_inet6_ip6, OID_AUTO, source_address_validation,
177     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_sav), true,
178     "Drop incoming packets with source address that is a local address");
179 
180 #ifdef RSS
181 static struct netisr_handler ip6_direct_nh = {
182 	.nh_name = "ip6_direct",
183 	.nh_handler = ip6_direct_input,
184 	.nh_proto = NETISR_IPV6_DIRECT,
185 	.nh_m2cpuid = rss_soft_m2cpuid_v6,
186 	.nh_policy = NETISR_POLICY_CPU,
187 	.nh_dispatch = NETISR_DISPATCH_HYBRID,
188 };
189 
190 static int
191 sysctl_netinet6_intr_direct_queue_maxlen(SYSCTL_HANDLER_ARGS)
192 {
193 	int error, qlimit;
194 
195 	netisr_getqlimit(&ip6_direct_nh, &qlimit);
196 	error = sysctl_handle_int(oidp, &qlimit, 0, req);
197 	if (error || !req->newptr)
198 		return (error);
199 	if (qlimit < 1)
200 		return (EINVAL);
201 	return (netisr_setqlimit(&ip6_direct_nh, qlimit));
202 }
203 SYSCTL_PROC(_net_inet6_ip6, IPV6CTL_INTRDQMAXLEN, intr_direct_queue_maxlen,
204     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
205     0, 0, sysctl_netinet6_intr_direct_queue_maxlen, "I",
206     "Maximum size of the IPv6 direct input queue");
207 
208 #endif
209 
210 VNET_DEFINE(pfil_head_t, inet6_pfil_head);
211 
212 VNET_PCPUSTAT_DEFINE(struct ip6stat, ip6stat);
213 VNET_PCPUSTAT_SYSINIT(ip6stat);
214 #ifdef VIMAGE
215 VNET_PCPUSTAT_SYSUNINIT(ip6stat);
216 #endif /* VIMAGE */
217 
218 struct rmlock in6_ifaddr_lock;
219 RM_SYSINIT(in6_ifaddr_lock, &in6_ifaddr_lock, "in6_ifaddr_lock");
220 
221 static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *);
222 
223 /*
224  * IP6 initialization: fill in IP6 protocol switch table.
225  * All protocols not implemented in kernel go to raw IP6 protocol handler.
226  */
227 static void
228 ip6_vnet_init(void *arg __unused)
229 {
230 	struct pfil_head_args args;
231 
232 	TUNABLE_INT_FETCH("net.inet6.ip6.auto_linklocal",
233 	    &V_ip6_auto_linklocal);
234 	TUNABLE_INT_FETCH("net.inet6.ip6.accept_rtadv", &V_ip6_accept_rtadv);
235 	TUNABLE_INT_FETCH("net.inet6.ip6.no_radr", &V_ip6_no_radr);
236 
237 	CK_STAILQ_INIT(&V_in6_ifaddrhead);
238 	V_in6_ifaddrhashtbl = hashinit(IN6ADDR_NHASH, M_IFADDR,
239 	    &V_in6_ifaddrhmask);
240 
241 	/* Initialize packet filter hooks. */
242 	args.pa_version = PFIL_VERSION;
243 	args.pa_flags = PFIL_IN | PFIL_OUT;
244 	args.pa_type = PFIL_TYPE_IP6;
245 	args.pa_headname = PFIL_INET6_NAME;
246 	V_inet6_pfil_head = pfil_head_register(&args);
247 
248 	if (hhook_head_register(HHOOK_TYPE_IPSEC_IN, AF_INET6,
249 	    &V_ipsec_hhh_in[HHOOK_IPSEC_INET6],
250 	    HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0)
251 		printf("%s: WARNING: unable to register input helper hook\n",
252 		    __func__);
253 	if (hhook_head_register(HHOOK_TYPE_IPSEC_OUT, AF_INET6,
254 	    &V_ipsec_hhh_out[HHOOK_IPSEC_INET6],
255 	    HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0)
256 		printf("%s: WARNING: unable to register output helper hook\n",
257 		    __func__);
258 
259 	scope6_init();
260 	addrsel_policy_init();
261 	nd6_init();
262 	frag6_init();
263 
264 	V_ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR;
265 
266 	/* Skip global initialization stuff for non-default instances. */
267 #ifdef VIMAGE
268 	netisr_register_vnet(&ip6_nh);
269 #ifdef RSS
270 	netisr_register_vnet(&ip6_direct_nh);
271 #endif
272 #endif
273 }
274 VNET_SYSINIT(ip6_vnet_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH,
275     ip6_vnet_init, NULL);
276 
277 static void
278 ip6_init(void *arg __unused)
279 {
280 
281 	/*
282 	 * Register statically those protocols that are unlikely to ever go
283 	 * dynamic.
284 	 */
285 	IP6PROTO_REGISTER(IPPROTO_ICMPV6, icmp6_input, rip6_ctlinput);
286 	IP6PROTO_REGISTER(IPPROTO_DSTOPTS, dest6_input, NULL);
287 	IP6PROTO_REGISTER(IPPROTO_ROUTING, route6_input, NULL);
288 	IP6PROTO_REGISTER(IPPROTO_FRAGMENT, frag6_input, NULL);
289 	IP6PROTO_REGISTER(IPPROTO_IPV4, encap6_input, NULL);
290 	IP6PROTO_REGISTER(IPPROTO_IPV6, encap6_input, NULL);
291 	IP6PROTO_REGISTER(IPPROTO_ETHERIP, encap6_input, NULL);
292 	IP6PROTO_REGISTER(IPPROTO_GRE, encap6_input, NULL);
293 	IP6PROTO_REGISTER(IPPROTO_PIM, encap6_input, NULL);
294 #ifdef SCTP	/* XXX: has a loadable & static version */
295 	IP6PROTO_REGISTER(IPPROTO_SCTP, sctp6_input, sctp6_ctlinput);
296 #endif
297 
298 	EVENTHANDLER_REGISTER(vm_lowmem, frag6_drain, NULL, LOWMEM_PRI_DEFAULT);
299 	EVENTHANDLER_REGISTER(mbuf_lowmem, frag6_drain, NULL,
300 	    LOWMEM_PRI_DEFAULT);
301 
302 	netisr_register(&ip6_nh);
303 #ifdef RSS
304 	netisr_register(&ip6_direct_nh);
305 #endif
306 }
307 SYSINIT(ip6_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, ip6_init, NULL);
308 
309 int
310 ip6proto_register(uint8_t proto, ipproto_input_t input, ipproto_ctlinput_t ctl)
311 {
312 
313 	MPASS(proto > 0);
314 
315 	if (ip6_protox[proto] == rip6_input) {
316 		ip6_protox[proto] = input;
317 		ip6_ctlprotox[proto] = ctl;
318 		return (0);
319 	} else
320 		return (EEXIST);
321 }
322 
323 int
324 ip6proto_unregister(uint8_t proto)
325 {
326 
327 	MPASS(proto > 0);
328 
329 	if (ip6_protox[proto] != rip6_input) {
330 		ip6_protox[proto] = rip6_input;
331 		ip6_ctlprotox[proto] = rip6_ctlinput;
332 		return (0);
333 	} else
334 		return (ENOENT);
335 }
336 
337 #ifdef VIMAGE
338 static void
339 ip6_destroy(void *unused __unused)
340 {
341 	struct ifaddr *ifa, *nifa;
342 	struct ifnet *ifp;
343 	int error;
344 
345 #ifdef RSS
346 	netisr_unregister_vnet(&ip6_direct_nh);
347 #endif
348 	netisr_unregister_vnet(&ip6_nh);
349 
350 	pfil_head_unregister(V_inet6_pfil_head);
351 	error = hhook_head_deregister(V_ipsec_hhh_in[HHOOK_IPSEC_INET6]);
352 	if (error != 0) {
353 		printf("%s: WARNING: unable to deregister input helper hook "
354 		    "type HHOOK_TYPE_IPSEC_IN, id HHOOK_IPSEC_INET6: "
355 		    "error %d returned\n", __func__, error);
356 	}
357 	error = hhook_head_deregister(V_ipsec_hhh_out[HHOOK_IPSEC_INET6]);
358 	if (error != 0) {
359 		printf("%s: WARNING: unable to deregister output helper hook "
360 		    "type HHOOK_TYPE_IPSEC_OUT, id HHOOK_IPSEC_INET6: "
361 		    "error %d returned\n", __func__, error);
362 	}
363 
364 	/* Cleanup addresses. */
365 	IFNET_RLOCK();
366 	CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
367 		/* Cannot lock here - lock recursion. */
368 		/* IF_ADDR_LOCK(ifp); */
369 		CK_STAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, nifa) {
370 			if (ifa->ifa_addr->sa_family != AF_INET6)
371 				continue;
372 			in6_purgeaddr(ifa);
373 		}
374 		/* IF_ADDR_UNLOCK(ifp); */
375 		in6_ifdetach_destroy(ifp);
376 		mld_domifdetach(ifp);
377 	}
378 	IFNET_RUNLOCK();
379 
380 	/* Make sure any routes are gone as well. */
381 	rib_flush_routes_family(AF_INET6);
382 
383 	frag6_destroy();
384 	nd6_destroy();
385 	in6_ifattach_destroy();
386 
387 	hashdestroy(V_in6_ifaddrhashtbl, M_IFADDR, V_in6_ifaddrhmask);
388 }
389 
390 VNET_SYSUNINIT(inet6, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, ip6_destroy, NULL);
391 #endif
392 
393 static int
394 ip6_input_hbh(struct mbuf **mp, uint32_t *plen, uint32_t *rtalert, int *off,
395     int *nxt, int *ours)
396 {
397 	struct mbuf *m;
398 	struct ip6_hdr *ip6;
399 	struct ip6_hbh *hbh;
400 
401 	if (ip6_hopopts_input(plen, rtalert, mp, off)) {
402 #if 0	/*touches NULL pointer*/
403 		in6_ifstat_inc((*mp)->m_pkthdr.rcvif, ifs6_in_discard);
404 #endif
405 		goto out;	/* m have already been freed */
406 	}
407 
408 	/* adjust pointer */
409 	m = *mp;
410 	ip6 = mtod(m, struct ip6_hdr *);
411 
412 	/*
413 	 * if the payload length field is 0 and the next header field
414 	 * indicates Hop-by-Hop Options header, then a Jumbo Payload
415 	 * option MUST be included.
416 	 */
417 	if (ip6->ip6_plen == 0 && *plen == 0) {
418 		/*
419 		 * Note that if a valid jumbo payload option is
420 		 * contained, ip6_hopopts_input() must set a valid
421 		 * (non-zero) payload length to the variable plen.
422 		 */
423 		IP6STAT_INC(ip6s_badoptions);
424 		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
425 		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
426 		icmp6_error(m, ICMP6_PARAM_PROB,
427 			    ICMP6_PARAMPROB_HEADER,
428 			    (caddr_t)&ip6->ip6_plen - (caddr_t)ip6);
429 		goto out;
430 	}
431 	/* ip6_hopopts_input() ensures that mbuf is contiguous */
432 	hbh = (struct ip6_hbh *)(ip6 + 1);
433 	*nxt = hbh->ip6h_nxt;
434 
435 	/*
436 	 * If we are acting as a router and the packet contains a
437 	 * router alert option, see if we know the option value.
438 	 * Currently, we only support the option value for MLD, in which
439 	 * case we should pass the packet to the multicast routing
440 	 * daemon.
441 	 */
442 	if (*rtalert != ~0) {
443 		switch (*rtalert) {
444 		case IP6OPT_RTALERT_MLD:
445 			if (V_ip6_forwarding)
446 				*ours = 1;
447 			break;
448 		default:
449 			/*
450 			 * RFC2711 requires unrecognized values must be
451 			 * silently ignored.
452 			 */
453 			break;
454 		}
455 	}
456 
457 	return (0);
458 
459 out:
460 	return (1);
461 }
462 
463 #ifdef RSS
464 /*
465  * IPv6 direct input routine.
466  *
467  * This is called when reinjecting completed fragments where
468  * all of the previous checking and book-keeping has been done.
469  */
470 void
471 ip6_direct_input(struct mbuf *m)
472 {
473 	int off, nxt;
474 	int nest;
475 	struct m_tag *mtag;
476 	struct ip6_direct_ctx *ip6dc;
477 
478 	mtag = m_tag_locate(m, MTAG_ABI_IPV6, IPV6_TAG_DIRECT, NULL);
479 	KASSERT(mtag != NULL, ("Reinjected packet w/o direct ctx tag!"));
480 
481 	ip6dc = (struct ip6_direct_ctx *)(mtag + 1);
482 	nxt = ip6dc->ip6dc_nxt;
483 	off = ip6dc->ip6dc_off;
484 
485 	nest = 0;
486 
487 	m_tag_delete(m, mtag);
488 
489 	while (nxt != IPPROTO_DONE) {
490 		if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) {
491 			IP6STAT_INC(ip6s_toomanyhdr);
492 			goto bad;
493 		}
494 
495 		/*
496 		 * protection against faulty packet - there should be
497 		 * more sanity checks in header chain processing.
498 		 */
499 		if (m->m_pkthdr.len < off) {
500 			IP6STAT_INC(ip6s_tooshort);
501 			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
502 			goto bad;
503 		}
504 
505 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
506 		if (IPSEC_ENABLED(ipv6)) {
507 			if (IPSEC_INPUT(ipv6, m, off, nxt) != 0)
508 				return;
509 		}
510 #endif /* IPSEC */
511 
512 		nxt = ip6_protox[nxt](&m, &off, nxt);
513 	}
514 	return;
515 bad:
516 	m_freem(m);
517 }
518 #endif
519 
520 void
521 ip6_input(struct mbuf *m)
522 {
523 	struct in6_addr odst;
524 	struct ip6_hdr *ip6;
525 	struct in6_ifaddr *ia;
526 	struct ifnet *rcvif;
527 	u_int32_t plen;
528 	u_int32_t rtalert = ~0;
529 	int off = sizeof(struct ip6_hdr), nest;
530 	int nxt, ours = 0;
531 	int srcrt = 0;
532 
533 	/*
534 	 * Drop the packet if IPv6 operation is disabled on the interface.
535 	 */
536 	rcvif = m->m_pkthdr.rcvif;
537 	if ((ND_IFINFO(rcvif)->flags & ND6_IFF_IFDISABLED))
538 		goto bad;
539 
540 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
541 	/*
542 	 * should the inner packet be considered authentic?
543 	 * see comment in ah4_input().
544 	 * NB: m cannot be NULL when passed to the input routine
545 	 */
546 
547 	m->m_flags &= ~M_AUTHIPHDR;
548 	m->m_flags &= ~M_AUTHIPDGM;
549 
550 #endif /* IPSEC */
551 
552 	if (m->m_flags & M_FASTFWD_OURS) {
553 		/*
554 		 * Firewall changed destination to local.
555 		 */
556 		ip6 = mtod(m, struct ip6_hdr *);
557 		goto passin;
558 	}
559 
560 	/*
561 	 * mbuf statistics
562 	 */
563 	if (m->m_flags & M_EXT) {
564 		if (m->m_next)
565 			IP6STAT_INC(ip6s_mext2m);
566 		else
567 			IP6STAT_INC(ip6s_mext1);
568 	} else {
569 		if (m->m_next) {
570 			struct ifnet *ifp = (m->m_flags & M_LOOP) ? V_loif : rcvif;
571 			int ifindex = ifp->if_index;
572 			if (ifindex >= IP6S_M2MMAX)
573 				ifindex = 0;
574 			IP6STAT_INC(ip6s_m2m[ifindex]);
575 		} else
576 			IP6STAT_INC(ip6s_m1);
577 	}
578 
579 	in6_ifstat_inc(rcvif, ifs6_in_receive);
580 	IP6STAT_INC(ip6s_total);
581 
582 	/*
583 	 * L2 bridge code and some other code can return mbuf chain
584 	 * that does not conform to KAME requirement.  too bad.
585 	 * XXX: fails to join if interface MTU > MCLBYTES.  jumbogram?
586 	 */
587 	if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) {
588 		struct mbuf *n;
589 
590 		if (m->m_pkthdr.len > MHLEN)
591 			n = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
592 		else
593 			n = m_gethdr(M_NOWAIT, MT_DATA);
594 		if (n == NULL)
595 			goto bad;
596 
597 		m_move_pkthdr(n, m);
598 		m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
599 		n->m_len = n->m_pkthdr.len;
600 		m_freem(m);
601 		m = n;
602 	}
603 	if (m->m_len < sizeof(struct ip6_hdr)) {
604 		if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
605 			IP6STAT_INC(ip6s_toosmall);
606 			in6_ifstat_inc(rcvif, ifs6_in_hdrerr);
607 			goto bad;
608 		}
609 	}
610 
611 	ip6 = mtod(m, struct ip6_hdr *);
612 	if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
613 		IP6STAT_INC(ip6s_badvers);
614 		in6_ifstat_inc(rcvif, ifs6_in_hdrerr);
615 		goto bad;
616 	}
617 
618 	IP6STAT_INC(ip6s_nxthist[ip6->ip6_nxt]);
619 	IP_PROBE(receive, NULL, NULL, ip6, rcvif, NULL, ip6);
620 
621 	/*
622 	 * Check against address spoofing/corruption.
623 	 */
624 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) ||
625 	    IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) {
626 		/*
627 		 * XXX: "badscope" is not very suitable for a multicast source.
628 		 */
629 		IP6STAT_INC(ip6s_badscope);
630 		in6_ifstat_inc(rcvif, ifs6_in_addrerr);
631 		goto bad;
632 	}
633 	if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) &&
634 	    !(m->m_flags & M_LOOP)) {
635 		/*
636 		 * In this case, the packet should come from the loopback
637 		 * interface.  However, we cannot just check the if_flags,
638 		 * because ip6_mloopback() passes the "actual" interface
639 		 * as the outgoing/incoming interface.
640 		 */
641 		IP6STAT_INC(ip6s_badscope);
642 		in6_ifstat_inc(rcvif, ifs6_in_addrerr);
643 		goto bad;
644 	}
645 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
646 	    IPV6_ADDR_MC_SCOPE(&ip6->ip6_dst) == 0) {
647 		/*
648 		 * RFC4291 2.7:
649 		 * Nodes must not originate a packet to a multicast address
650 		 * whose scop field contains the reserved value 0; if such
651 		 * a packet is received, it must be silently dropped.
652 		 */
653 		IP6STAT_INC(ip6s_badscope);
654 		in6_ifstat_inc(rcvif, ifs6_in_addrerr);
655 		goto bad;
656 	}
657 #ifdef ALTQ
658 	if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) {
659 		/* packet is dropped by traffic conditioner */
660 		return;
661 	}
662 #endif
663 	/*
664 	 * The following check is not documented in specs.  A malicious
665 	 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack
666 	 * and bypass security checks (act as if it was from 127.0.0.1 by using
667 	 * IPv6 src ::ffff:127.0.0.1).  Be cautious.
668 	 *
669 	 * We have supported IPv6-only kernels for a few years and this issue
670 	 * has not come up.  The world seems to move mostly towards not using
671 	 * v4mapped on the wire, so it makes sense for us to keep rejecting
672 	 * any such packets.
673 	 */
674 	if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
675 	    IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
676 		IP6STAT_INC(ip6s_badscope);
677 		in6_ifstat_inc(rcvif, ifs6_in_addrerr);
678 		goto bad;
679 	}
680 #if 0
681 	/*
682 	 * Reject packets with IPv4 compatible addresses (auto tunnel).
683 	 *
684 	 * The code forbids auto tunnel relay case in RFC1933 (the check is
685 	 * stronger than RFC1933).  We may want to re-enable it if mech-xx
686 	 * is revised to forbid relaying case.
687 	 */
688 	if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
689 	    IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
690 		IP6STAT_INC(ip6s_badscope);
691 		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
692 		goto bad;
693 	}
694 #endif
695 	/*
696 	 * Try to forward the packet, but if we fail continue.
697 	 * ip6_tryforward() does not generate redirects, so fall
698 	 * through to normal processing if redirects are required.
699 	 * ip6_tryforward() does inbound and outbound packet firewall
700 	 * processing. If firewall has decided that destination becomes
701 	 * our local address, it sets M_FASTFWD_OURS flag. In this
702 	 * case skip another inbound firewall processing and update
703 	 * ip6 pointer.
704 	 */
705 	if (V_ip6_forwarding != 0 && V_ip6_sendredirects == 0
706 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
707 	    && (!IPSEC_ENABLED(ipv6) ||
708 	    IPSEC_CAPS(ipv6, m, IPSEC_CAP_OPERABLE) == 0)
709 #endif
710 	    ) {
711 		if ((m = ip6_tryforward(m)) == NULL)
712 			return;
713 		if (m->m_flags & M_FASTFWD_OURS) {
714 			ip6 = mtod(m, struct ip6_hdr *);
715 			goto passin;
716 		}
717 	}
718 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
719 	/*
720 	 * Bypass packet filtering for packets previously handled by IPsec.
721 	 */
722 	if (IPSEC_ENABLED(ipv6) &&
723 	    IPSEC_CAPS(ipv6, m, IPSEC_CAP_BYPASS_FILTER) != 0)
724 			goto passin;
725 #endif
726 	/*
727 	 * Run through list of hooks for input packets.
728 	 *
729 	 * NB: Beware of the destination address changing
730 	 *     (e.g. by NAT rewriting).  When this happens,
731 	 *     tell ip6_forward to do the right thing.
732 	 */
733 
734 	/* Jump over all PFIL processing if hooks are not active. */
735 	if (!PFIL_HOOKED_IN(V_inet6_pfil_head))
736 		goto passin;
737 
738 	odst = ip6->ip6_dst;
739 	if (pfil_run_hooks(V_inet6_pfil_head, &m, m->m_pkthdr.rcvif, PFIL_IN,
740 	    NULL) != PFIL_PASS)
741 		return;
742 	ip6 = mtod(m, struct ip6_hdr *);
743 	srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst);
744 	if ((m->m_flags & (M_IP6_NEXTHOP | M_FASTFWD_OURS)) == M_IP6_NEXTHOP &&
745 	    m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL) {
746 		/*
747 		 * Directly ship the packet on.  This allows forwarding
748 		 * packets originally destined to us to some other directly
749 		 * connected host.
750 		 */
751 		ip6_forward(m, 1);
752 		return;
753 	}
754 
755 passin:
756 	/*
757 	 * Disambiguate address scope zones (if there is ambiguity).
758 	 * We first make sure that the original source or destination address
759 	 * is not in our internal form for scoped addresses.  Such addresses
760 	 * are not necessarily invalid spec-wise, but we cannot accept them due
761 	 * to the usage conflict.
762 	 * in6_setscope() then also checks and rejects the cases where src or
763 	 * dst are the loopback address and the receiving interface
764 	 * is not loopback.
765 	 */
766 	if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) {
767 		IP6STAT_INC(ip6s_badscope); /* XXX */
768 		goto bad;
769 	}
770 	if (in6_setscope(&ip6->ip6_src, rcvif, NULL) ||
771 	    in6_setscope(&ip6->ip6_dst, rcvif, NULL)) {
772 		IP6STAT_INC(ip6s_badscope);
773 		goto bad;
774 	}
775 	if (m->m_flags & M_FASTFWD_OURS) {
776 		m->m_flags &= ~M_FASTFWD_OURS;
777 		ours = 1;
778 		goto hbhcheck;
779 	}
780 	/*
781 	 * Multicast check. Assume packet is for us to avoid
782 	 * prematurely taking locks.
783 	 */
784 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
785 		ours = 1;
786 		in6_ifstat_inc(rcvif, ifs6_in_mcast);
787 		goto hbhcheck;
788 	}
789 	/*
790 	 * Unicast check
791 	 * XXX: For now we keep link-local IPv6 addresses with embedded
792 	 *      scope zone id, therefore we use zero zoneid here.
793 	 */
794 	ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false);
795 	if (ia != NULL) {
796 		if (ia->ia6_flags & IN6_IFF_NOTREADY) {
797 			char ip6bufs[INET6_ADDRSTRLEN];
798 			char ip6bufd[INET6_ADDRSTRLEN];
799 			/* address is not ready, so discard the packet. */
800 			nd6log((LOG_INFO,
801 			    "ip6_input: packet to an unready address %s->%s\n",
802 			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
803 			    ip6_sprintf(ip6bufd, &ip6->ip6_dst)));
804 			goto bad;
805 		}
806 		if (V_ip6_sav && !(m->m_flags & M_LOOP) &&
807 		    __predict_false(in6_localip_fib(&ip6->ip6_src,
808 			    rcvif->if_fib))) {
809 			IP6STAT_INC(ip6s_badscope); /* XXX */
810 			goto bad;
811 		}
812 		/* Count the packet in the ip address stats */
813 		counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
814 		counter_u64_add(ia->ia_ifa.ifa_ibytes, m->m_pkthdr.len);
815 		ours = 1;
816 		goto hbhcheck;
817 	}
818 
819 	/*
820 	 * Now there is no reason to process the packet if it's not our own
821 	 * and we're not a router.
822 	 */
823 	if (!V_ip6_forwarding) {
824 		IP6STAT_INC(ip6s_cantforward);
825 		goto bad;
826 	}
827 
828   hbhcheck:
829 	/*
830 	 * Process Hop-by-Hop options header if it's contained.
831 	 * m may be modified in ip6_hopopts_input().
832 	 * If a JumboPayload option is included, plen will also be modified.
833 	 */
834 	plen = (u_int32_t)ntohs(ip6->ip6_plen);
835 	if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
836 		if (ip6_input_hbh(&m, &plen, &rtalert, &off, &nxt, &ours) != 0)
837 			return;
838 	} else
839 		nxt = ip6->ip6_nxt;
840 
841 	/*
842 	 * Use mbuf flags to propagate Router Alert option to
843 	 * ICMPv6 layer, as hop-by-hop options have been stripped.
844 	 */
845 	if (rtalert != ~0)
846 		m->m_flags |= M_RTALERT_MLD;
847 
848 	/*
849 	 * Check that the amount of data in the buffers
850 	 * is as at least much as the IPv6 header would have us expect.
851 	 * Trim mbufs if longer than we expect.
852 	 * Drop packet if shorter than we expect.
853 	 */
854 	if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
855 		IP6STAT_INC(ip6s_tooshort);
856 		in6_ifstat_inc(rcvif, ifs6_in_truncated);
857 		goto bad;
858 	}
859 	if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
860 		if (m->m_len == m->m_pkthdr.len) {
861 			m->m_len = sizeof(struct ip6_hdr) + plen;
862 			m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen;
863 		} else
864 			m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len);
865 	}
866 
867 	/*
868 	 * Forward if desirable.
869 	 */
870 	if (V_ip6_mrouter &&
871 	    IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
872 		/*
873 		 * If we are acting as a multicast router, all
874 		 * incoming multicast packets are passed to the
875 		 * kernel-level multicast forwarding function.
876 		 * The packet is returned (relatively) intact; if
877 		 * ip6_mforward() returns a non-zero value, the packet
878 		 * must be discarded, else it may be accepted below.
879 		 *
880 		 * XXX TODO: Check hlim and multicast scope here to avoid
881 		 * unnecessarily calling into ip6_mforward().
882 		 */
883 		if (ip6_mforward && ip6_mforward(ip6, rcvif, m)) {
884 			IP6STAT_INC(ip6s_cantforward);
885 			goto bad;
886 		}
887 	} else if (!ours) {
888 		ip6_forward(m, srcrt);
889 		return;
890 	}
891 
892 	/*
893 	 * Tell launch routine the next header
894 	 */
895 	IP6STAT_INC(ip6s_delivered);
896 	in6_ifstat_inc(rcvif, ifs6_in_deliver);
897 	nest = 0;
898 
899 	while (nxt != IPPROTO_DONE) {
900 		if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) {
901 			IP6STAT_INC(ip6s_toomanyhdr);
902 			goto bad;
903 		}
904 
905 		/*
906 		 * protection against faulty packet - there should be
907 		 * more sanity checks in header chain processing.
908 		 */
909 		if (m->m_pkthdr.len < off) {
910 			IP6STAT_INC(ip6s_tooshort);
911 			in6_ifstat_inc(rcvif, ifs6_in_truncated);
912 			goto bad;
913 		}
914 
915 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
916 		if (IPSEC_ENABLED(ipv6)) {
917 			if (IPSEC_INPUT(ipv6, m, off, nxt) != 0)
918 				return;
919 		}
920 #endif /* IPSEC */
921 
922 		nxt = ip6_protox[nxt](&m, &off, nxt);
923 	}
924 	return;
925 bad:
926 	in6_ifstat_inc(rcvif, ifs6_in_discard);
927 	if (m != NULL)
928 		m_freem(m);
929 }
930 
931 /*
932  * Hop-by-Hop options header processing. If a valid jumbo payload option is
933  * included, the real payload length will be stored in plenp.
934  *
935  * rtalertp - XXX: should be stored more smart way
936  */
937 static int
938 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp,
939     struct mbuf **mp, int *offp)
940 {
941 	struct mbuf *m = *mp;
942 	int off = *offp, hbhlen;
943 	struct ip6_hbh *hbh;
944 
945 	/* validation of the length of the header */
946 	if (m->m_len < off + sizeof(*hbh)) {
947 		m = m_pullup(m, off + sizeof(*hbh));
948 		if (m == NULL) {
949 			IP6STAT_INC(ip6s_exthdrtoolong);
950 			*mp = NULL;
951 			return (-1);
952 		}
953 	}
954 	hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
955 	hbhlen = (hbh->ip6h_len + 1) << 3;
956 
957 	if (m->m_len < off + hbhlen) {
958 		m = m_pullup(m, off + hbhlen);
959 		if (m == NULL) {
960 			IP6STAT_INC(ip6s_exthdrtoolong);
961 			*mp = NULL;
962 			return (-1);
963 		}
964 	}
965 	hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
966 	off += hbhlen;
967 	hbhlen -= sizeof(struct ip6_hbh);
968 	if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh),
969 				hbhlen, rtalertp, plenp) < 0) {
970 		*mp = NULL;
971 		return (-1);
972 	}
973 
974 	*offp = off;
975 	*mp = m;
976 	return (0);
977 }
978 
979 /*
980  * Search header for all Hop-by-hop options and process each option.
981  * This function is separate from ip6_hopopts_input() in order to
982  * handle a case where the sending node itself process its hop-by-hop
983  * options header. In such a case, the function is called from ip6_output().
984  *
985  * The function assumes that hbh header is located right after the IPv6 header
986  * (RFC2460 p7), opthead is pointer into data content in m, and opthead to
987  * opthead + hbhlen is located in contiguous memory region.
988  */
989 int
990 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen,
991     u_int32_t *rtalertp, u_int32_t *plenp)
992 {
993 	struct ip6_hdr *ip6;
994 	int optlen = 0;
995 	u_int8_t *opt = opthead;
996 	u_int16_t rtalert_val;
997 	u_int32_t jumboplen;
998 	const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh);
999 
1000 	for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
1001 		switch (*opt) {
1002 		case IP6OPT_PAD1:
1003 			optlen = 1;
1004 			break;
1005 		case IP6OPT_PADN:
1006 			if (hbhlen < IP6OPT_MINLEN) {
1007 				IP6STAT_INC(ip6s_toosmall);
1008 				goto bad;
1009 			}
1010 			optlen = *(opt + 1) + 2;
1011 			break;
1012 		case IP6OPT_ROUTER_ALERT:
1013 			/* XXX may need check for alignment */
1014 			if (hbhlen < IP6OPT_RTALERT_LEN) {
1015 				IP6STAT_INC(ip6s_toosmall);
1016 				goto bad;
1017 			}
1018 			if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
1019 				/* XXX stat */
1020 				icmp6_error(m, ICMP6_PARAM_PROB,
1021 				    ICMP6_PARAMPROB_HEADER,
1022 				    erroff + opt + 1 - opthead);
1023 				return (-1);
1024 			}
1025 			optlen = IP6OPT_RTALERT_LEN;
1026 			bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2);
1027 			*rtalertp = ntohs(rtalert_val);
1028 			break;
1029 		case IP6OPT_JUMBO:
1030 			/* XXX may need check for alignment */
1031 			if (hbhlen < IP6OPT_JUMBO_LEN) {
1032 				IP6STAT_INC(ip6s_toosmall);
1033 				goto bad;
1034 			}
1035 			if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
1036 				/* XXX stat */
1037 				icmp6_error(m, ICMP6_PARAM_PROB,
1038 				    ICMP6_PARAMPROB_HEADER,
1039 				    erroff + opt + 1 - opthead);
1040 				return (-1);
1041 			}
1042 			optlen = IP6OPT_JUMBO_LEN;
1043 
1044 			/*
1045 			 * IPv6 packets that have non 0 payload length
1046 			 * must not contain a jumbo payload option.
1047 			 */
1048 			ip6 = mtod(m, struct ip6_hdr *);
1049 			if (ip6->ip6_plen) {
1050 				IP6STAT_INC(ip6s_badoptions);
1051 				icmp6_error(m, ICMP6_PARAM_PROB,
1052 				    ICMP6_PARAMPROB_HEADER,
1053 				    erroff + opt - opthead);
1054 				return (-1);
1055 			}
1056 
1057 			/*
1058 			 * We may see jumbolen in unaligned location, so
1059 			 * we'd need to perform bcopy().
1060 			 */
1061 			bcopy(opt + 2, &jumboplen, sizeof(jumboplen));
1062 			jumboplen = (u_int32_t)htonl(jumboplen);
1063 
1064 #if 1
1065 			/*
1066 			 * if there are multiple jumbo payload options,
1067 			 * *plenp will be non-zero and the packet will be
1068 			 * rejected.
1069 			 * the behavior may need some debate in ipngwg -
1070 			 * multiple options does not make sense, however,
1071 			 * there's no explicit mention in specification.
1072 			 */
1073 			if (*plenp != 0) {
1074 				IP6STAT_INC(ip6s_badoptions);
1075 				icmp6_error(m, ICMP6_PARAM_PROB,
1076 				    ICMP6_PARAMPROB_HEADER,
1077 				    erroff + opt + 2 - opthead);
1078 				return (-1);
1079 			}
1080 #endif
1081 
1082 			/*
1083 			 * jumbo payload length must be larger than 65535.
1084 			 */
1085 			if (jumboplen <= IPV6_MAXPACKET) {
1086 				IP6STAT_INC(ip6s_badoptions);
1087 				icmp6_error(m, ICMP6_PARAM_PROB,
1088 				    ICMP6_PARAMPROB_HEADER,
1089 				    erroff + opt + 2 - opthead);
1090 				return (-1);
1091 			}
1092 			*plenp = jumboplen;
1093 
1094 			break;
1095 		default:		/* unknown option */
1096 			if (hbhlen < IP6OPT_MINLEN) {
1097 				IP6STAT_INC(ip6s_toosmall);
1098 				goto bad;
1099 			}
1100 			optlen = ip6_unknown_opt(opt, m,
1101 			    erroff + opt - opthead);
1102 			if (optlen == -1)
1103 				return (-1);
1104 			optlen += 2;
1105 			break;
1106 		}
1107 	}
1108 
1109 	return (0);
1110 
1111   bad:
1112 	m_freem(m);
1113 	return (-1);
1114 }
1115 
1116 /*
1117  * Unknown option processing.
1118  * The third argument `off' is the offset from the IPv6 header to the option,
1119  * which is necessary if the IPv6 header the and option header and IPv6 header
1120  * is not contiguous in order to return an ICMPv6 error.
1121  */
1122 int
1123 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off)
1124 {
1125 	struct ip6_hdr *ip6;
1126 
1127 	switch (IP6OPT_TYPE(*optp)) {
1128 	case IP6OPT_TYPE_SKIP: /* ignore the option */
1129 		return ((int)*(optp + 1));
1130 	case IP6OPT_TYPE_DISCARD:	/* silently discard */
1131 		m_freem(m);
1132 		return (-1);
1133 	case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */
1134 		IP6STAT_INC(ip6s_badoptions);
1135 		icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
1136 		return (-1);
1137 	case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
1138 		IP6STAT_INC(ip6s_badoptions);
1139 		ip6 = mtod(m, struct ip6_hdr *);
1140 		if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
1141 		    (m->m_flags & (M_BCAST|M_MCAST)))
1142 			m_freem(m);
1143 		else
1144 			icmp6_error(m, ICMP6_PARAM_PROB,
1145 				    ICMP6_PARAMPROB_OPTION, off);
1146 		return (-1);
1147 	}
1148 
1149 	m_freem(m);		/* XXX: NOTREACHED */
1150 	return (-1);
1151 }
1152 
1153 /*
1154  * Create the "control" list for this pcb.
1155  * These functions will not modify mbuf chain at all.
1156  *
1157  * The routine will be called from upper layer handlers like tcp6_input().
1158  * Thus the routine assumes that the caller (tcp6_input) have already
1159  * called m_pullup() and all the extension headers are located in the
1160  * very first mbuf on the mbuf chain.
1161  *
1162  * ip6_savecontrol_v4 will handle those options that are possible to be
1163  * set on a v4-mapped socket.
1164  * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those
1165  * options and handle the v6-only ones itself.
1166  */
1167 struct mbuf **
1168 ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp,
1169     int *v4only)
1170 {
1171 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1172 
1173 #ifdef SO_TIMESTAMP
1174 	if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) {
1175 		union {
1176 			struct timeval tv;
1177 			struct bintime bt;
1178 			struct timespec ts;
1179 		} t;
1180 		struct bintime boottimebin, bt1;
1181 		struct timespec ts1;
1182 		bool stamped;
1183 
1184 		stamped = false;
1185 		switch (inp->inp_socket->so_ts_clock) {
1186 		case SO_TS_REALTIME_MICRO:
1187 			if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1188 			    M_TSTMP)) {
1189 				mbuf_tstmp2timespec(m, &ts1);
1190 				timespec2bintime(&ts1, &bt1);
1191 				getboottimebin(&boottimebin);
1192 				bintime_add(&bt1, &boottimebin);
1193 				bintime2timeval(&bt1, &t.tv);
1194 			} else {
1195 				microtime(&t.tv);
1196 			}
1197 			*mp = sbcreatecontrol(&t.tv, sizeof(t.tv),
1198 			    SCM_TIMESTAMP, SOL_SOCKET, M_NOWAIT);
1199 			if (*mp != NULL) {
1200 				mp = &(*mp)->m_next;
1201 				stamped = true;
1202 			}
1203 			break;
1204 
1205 		case SO_TS_BINTIME:
1206 			if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1207 			    M_TSTMP)) {
1208 				mbuf_tstmp2timespec(m, &ts1);
1209 				timespec2bintime(&ts1, &t.bt);
1210 				getboottimebin(&boottimebin);
1211 				bintime_add(&t.bt, &boottimebin);
1212 			} else {
1213 				bintime(&t.bt);
1214 			}
1215 			*mp = sbcreatecontrol(&t.bt, sizeof(t.bt), SCM_BINTIME,
1216 			    SOL_SOCKET, M_NOWAIT);
1217 			if (*mp != NULL) {
1218 				mp = &(*mp)->m_next;
1219 				stamped = true;
1220 			}
1221 			break;
1222 
1223 		case SO_TS_REALTIME:
1224 			if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1225 			    M_TSTMP)) {
1226 				mbuf_tstmp2timespec(m, &t.ts);
1227 				getboottimebin(&boottimebin);
1228 				bintime2timespec(&boottimebin, &ts1);
1229 				timespecadd(&t.ts, &ts1, &t.ts);
1230 			} else {
1231 				nanotime(&t.ts);
1232 			}
1233 			*mp = sbcreatecontrol(&t.ts, sizeof(t.ts),
1234 			    SCM_REALTIME, SOL_SOCKET, M_NOWAIT);
1235 			if (*mp != NULL) {
1236 				mp = &(*mp)->m_next;
1237 				stamped = true;
1238 			}
1239 			break;
1240 
1241 		case SO_TS_MONOTONIC:
1242 			if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1243 			    M_TSTMP))
1244 				mbuf_tstmp2timespec(m, &t.ts);
1245 			else
1246 				nanouptime(&t.ts);
1247 			*mp = sbcreatecontrol(&t.ts, sizeof(t.ts),
1248 			    SCM_MONOTONIC, SOL_SOCKET, M_NOWAIT);
1249 			if (*mp != NULL) {
1250 				mp = &(*mp)->m_next;
1251 				stamped = true;
1252 			}
1253 			break;
1254 
1255 		default:
1256 			panic("unknown (corrupted) so_ts_clock");
1257 		}
1258 		if (stamped && (m->m_flags & (M_PKTHDR | M_TSTMP)) ==
1259 		    (M_PKTHDR | M_TSTMP)) {
1260 			struct sock_timestamp_info sti;
1261 
1262 			bzero(&sti, sizeof(sti));
1263 			sti.st_info_flags = ST_INFO_HW;
1264 			if ((m->m_flags & M_TSTMP_HPREC) != 0)
1265 				sti.st_info_flags |= ST_INFO_HW_HPREC;
1266 			*mp = sbcreatecontrol(&sti, sizeof(sti), SCM_TIME_INFO,
1267 			    SOL_SOCKET, M_NOWAIT);
1268 			if (*mp != NULL)
1269 				mp = &(*mp)->m_next;
1270 		}
1271 	}
1272 #endif
1273 
1274 #define IS2292(inp, x, y)	(((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y))
1275 	/* RFC 2292 sec. 5 */
1276 	if ((inp->inp_flags & IN6P_PKTINFO) != 0) {
1277 		struct in6_pktinfo pi6;
1278 
1279 		if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1280 #ifdef INET
1281 			struct ip *ip;
1282 
1283 			ip = mtod(m, struct ip *);
1284 			pi6.ipi6_addr.s6_addr32[0] = 0;
1285 			pi6.ipi6_addr.s6_addr32[1] = 0;
1286 			pi6.ipi6_addr.s6_addr32[2] = IPV6_ADDR_INT32_SMP;
1287 			pi6.ipi6_addr.s6_addr32[3] = ip->ip_dst.s_addr;
1288 #else
1289 			/* We won't hit this code */
1290 			bzero(&pi6.ipi6_addr, sizeof(struct in6_addr));
1291 #endif
1292 		} else {
1293 			bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr));
1294 			in6_clearscope(&pi6.ipi6_addr);	/* XXX */
1295 		}
1296 		pi6.ipi6_ifindex =
1297 		    (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0;
1298 
1299 		*mp = sbcreatecontrol(&pi6, sizeof(struct in6_pktinfo),
1300 		    IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6,
1301 		    M_NOWAIT);
1302 		if (*mp)
1303 			mp = &(*mp)->m_next;
1304 	}
1305 
1306 	if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) {
1307 		int hlim;
1308 
1309 		if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1310 #ifdef INET
1311 			struct ip *ip;
1312 
1313 			ip = mtod(m, struct ip *);
1314 			hlim = ip->ip_ttl;
1315 #else
1316 			/* We won't hit this code */
1317 			hlim = 0;
1318 #endif
1319 		} else {
1320 			hlim = ip6->ip6_hlim & 0xff;
1321 		}
1322 		*mp = sbcreatecontrol(&hlim, sizeof(int),
1323 		    IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT),
1324 		    IPPROTO_IPV6, M_NOWAIT);
1325 		if (*mp)
1326 			mp = &(*mp)->m_next;
1327 	}
1328 
1329 	if ((inp->inp_flags & IN6P_TCLASS) != 0) {
1330 		int tclass;
1331 
1332 		if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1333 #ifdef INET
1334 			struct ip *ip;
1335 
1336 			ip = mtod(m, struct ip *);
1337 			tclass = ip->ip_tos;
1338 #else
1339 			/* We won't hit this code */
1340 			tclass = 0;
1341 #endif
1342 		} else {
1343 			u_int32_t flowinfo;
1344 
1345 			flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK);
1346 			flowinfo >>= 20;
1347 			tclass = flowinfo & 0xff;
1348 		}
1349 		*mp = sbcreatecontrol(&tclass, sizeof(int), IPV6_TCLASS,
1350 		    IPPROTO_IPV6, M_NOWAIT);
1351 		if (*mp)
1352 			mp = &(*mp)->m_next;
1353 	}
1354 
1355 	if (v4only != NULL) {
1356 		if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1357 			*v4only = 1;
1358 		} else {
1359 			*v4only = 0;
1360 		}
1361 	}
1362 
1363 	return (mp);
1364 }
1365 
1366 void
1367 ip6_savecontrol(struct inpcb *inp, struct mbuf *m, struct mbuf **mp)
1368 {
1369 	struct ip6_hdr *ip6;
1370 	int v4only = 0;
1371 
1372 	mp = ip6_savecontrol_v4(inp, m, mp, &v4only);
1373 	if (v4only)
1374 		return;
1375 
1376 	ip6 = mtod(m, struct ip6_hdr *);
1377 	/*
1378 	 * IPV6_HOPOPTS socket option.  Recall that we required super-user
1379 	 * privilege for the option (see ip6_ctloutput), but it might be too
1380 	 * strict, since there might be some hop-by-hop options which can be
1381 	 * returned to normal user.
1382 	 * See also RFC 2292 section 6 (or RFC 3542 section 8).
1383 	 */
1384 	if ((inp->inp_flags & IN6P_HOPOPTS) != 0) {
1385 		/*
1386 		 * Check if a hop-by-hop options header is contatined in the
1387 		 * received packet, and if so, store the options as ancillary
1388 		 * data. Note that a hop-by-hop options header must be
1389 		 * just after the IPv6 header, which is assured through the
1390 		 * IPv6 input processing.
1391 		 */
1392 		if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
1393 			struct ip6_hbh *hbh;
1394 			u_int hbhlen;
1395 
1396 			hbh = (struct ip6_hbh *)(ip6 + 1);
1397 			hbhlen = (hbh->ip6h_len + 1) << 3;
1398 
1399 			/*
1400 			 * XXX: We copy the whole header even if a
1401 			 * jumbo payload option is included, the option which
1402 			 * is to be removed before returning according to
1403 			 * RFC2292.
1404 			 * Note: this constraint is removed in RFC3542
1405 			 */
1406 			*mp = sbcreatecontrol(hbh, hbhlen,
1407 			    IS2292(inp, IPV6_2292HOPOPTS, IPV6_HOPOPTS),
1408 			    IPPROTO_IPV6, M_NOWAIT);
1409 			if (*mp)
1410 				mp = &(*mp)->m_next;
1411 		}
1412 	}
1413 
1414 	if ((inp->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) {
1415 		int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);
1416 
1417 		/*
1418 		 * Search for destination options headers or routing
1419 		 * header(s) through the header chain, and stores each
1420 		 * header as ancillary data.
1421 		 * Note that the order of the headers remains in
1422 		 * the chain of ancillary data.
1423 		 */
1424 		while (1) {	/* is explicit loop prevention necessary? */
1425 			struct ip6_ext *ip6e = NULL;
1426 			u_int elen;
1427 
1428 			/*
1429 			 * if it is not an extension header, don't try to
1430 			 * pull it from the chain.
1431 			 */
1432 			switch (nxt) {
1433 			case IPPROTO_DSTOPTS:
1434 			case IPPROTO_ROUTING:
1435 			case IPPROTO_HOPOPTS:
1436 			case IPPROTO_AH: /* is it possible? */
1437 				break;
1438 			default:
1439 				goto loopend;
1440 			}
1441 
1442 			if (off + sizeof(*ip6e) > m->m_len)
1443 				goto loopend;
1444 			ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
1445 			if (nxt == IPPROTO_AH)
1446 				elen = (ip6e->ip6e_len + 2) << 2;
1447 			else
1448 				elen = (ip6e->ip6e_len + 1) << 3;
1449 			if (off + elen > m->m_len)
1450 				goto loopend;
1451 
1452 			switch (nxt) {
1453 			case IPPROTO_DSTOPTS:
1454 				if (!(inp->inp_flags & IN6P_DSTOPTS))
1455 					break;
1456 
1457 				*mp = sbcreatecontrol(ip6e, elen,
1458 				    IS2292(inp, IPV6_2292DSTOPTS, IPV6_DSTOPTS),
1459 				    IPPROTO_IPV6, M_NOWAIT);
1460 				if (*mp)
1461 					mp = &(*mp)->m_next;
1462 				break;
1463 			case IPPROTO_ROUTING:
1464 				if (!(inp->inp_flags & IN6P_RTHDR))
1465 					break;
1466 
1467 				*mp = sbcreatecontrol(ip6e, elen,
1468 				    IS2292(inp, IPV6_2292RTHDR, IPV6_RTHDR),
1469 				    IPPROTO_IPV6, M_NOWAIT);
1470 				if (*mp)
1471 					mp = &(*mp)->m_next;
1472 				break;
1473 			case IPPROTO_HOPOPTS:
1474 			case IPPROTO_AH: /* is it possible? */
1475 				break;
1476 
1477 			default:
1478 				/*
1479 				 * other cases have been filtered in the above.
1480 				 * none will visit this case.  here we supply
1481 				 * the code just in case (nxt overwritten or
1482 				 * other cases).
1483 				 */
1484 				goto loopend;
1485 			}
1486 
1487 			/* proceed with the next header. */
1488 			off += elen;
1489 			nxt = ip6e->ip6e_nxt;
1490 			ip6e = NULL;
1491 		}
1492 	  loopend:
1493 		;
1494 	}
1495 
1496 	if (inp->inp_flags2 & INP_RECVFLOWID) {
1497 		uint32_t flowid, flow_type;
1498 
1499 		flowid = m->m_pkthdr.flowid;
1500 		flow_type = M_HASHTYPE_GET(m);
1501 
1502 		/*
1503 		 * XXX should handle the failure of one or the
1504 		 * other - don't populate both?
1505 		 */
1506 		*mp = sbcreatecontrol(&flowid, sizeof(uint32_t), IPV6_FLOWID,
1507 		    IPPROTO_IPV6, M_NOWAIT);
1508 		if (*mp)
1509 			mp = &(*mp)->m_next;
1510 		*mp = sbcreatecontrol(&flow_type, sizeof(uint32_t),
1511 		    IPV6_FLOWTYPE, IPPROTO_IPV6, M_NOWAIT);
1512 		if (*mp)
1513 			mp = &(*mp)->m_next;
1514 	}
1515 
1516 #ifdef	RSS
1517 	if (inp->inp_flags2 & INP_RECVRSSBUCKETID) {
1518 		uint32_t flowid, flow_type;
1519 		uint32_t rss_bucketid;
1520 
1521 		flowid = m->m_pkthdr.flowid;
1522 		flow_type = M_HASHTYPE_GET(m);
1523 
1524 		if (rss_hash2bucket(flowid, flow_type, &rss_bucketid) == 0) {
1525 			*mp = sbcreatecontrol(&rss_bucketid, sizeof(uint32_t),
1526 			    IPV6_RSSBUCKETID, IPPROTO_IPV6, M_NOWAIT);
1527 			if (*mp)
1528 				mp = &(*mp)->m_next;
1529 		}
1530 	}
1531 #endif
1532 
1533 }
1534 #undef IS2292
1535 
1536 void
1537 ip6_notify_pmtu(struct inpcb *inp, struct sockaddr_in6 *dst, u_int32_t mtu)
1538 {
1539 	struct socket *so;
1540 	struct mbuf *m_mtu;
1541 	struct ip6_mtuinfo mtuctl;
1542 
1543 	KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
1544 	/*
1545 	 * Notify the error by sending IPV6_PATHMTU ancillary data if
1546 	 * application wanted to know the MTU value.
1547 	 * NOTE: we notify disconnected sockets, because some udp
1548 	 * applications keep sending sockets disconnected.
1549 	 * NOTE: our implementation doesn't notify connected sockets that has
1550 	 * foreign address that is different than given destination addresses
1551 	 * (this is permitted by RFC 3542).
1552 	 */
1553 	if ((inp->inp_flags & IN6P_MTU) == 0 || (
1554 	    !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) &&
1555 	    !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &dst->sin6_addr)))
1556 		return;
1557 
1558 	mtuctl.ip6m_mtu = mtu;
1559 	mtuctl.ip6m_addr = *dst;
1560 	if (sa6_recoverscope(&mtuctl.ip6m_addr))
1561 		return;
1562 
1563 	if ((m_mtu = sbcreatecontrol(&mtuctl, sizeof(mtuctl), IPV6_PATHMTU,
1564 	    IPPROTO_IPV6, M_NOWAIT)) == NULL)
1565 		return;
1566 
1567 	so =  inp->inp_socket;
1568 	if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu)
1569 	    == 0) {
1570 		soroverflow(so);
1571 		m_freem(m_mtu);
1572 		/* XXX: should count statistics */
1573 	} else
1574 		sorwakeup(so);
1575 }
1576 
1577 /*
1578  * Get pointer to the previous header followed by the header
1579  * currently processed.
1580  */
1581 int
1582 ip6_get_prevhdr(const struct mbuf *m, int off)
1583 {
1584 	struct ip6_ext ip6e;
1585 	struct ip6_hdr *ip6;
1586 	int len, nlen, nxt;
1587 
1588 	if (off == sizeof(struct ip6_hdr))
1589 		return (offsetof(struct ip6_hdr, ip6_nxt));
1590 	if (off < sizeof(struct ip6_hdr))
1591 		panic("%s: off < sizeof(struct ip6_hdr)", __func__);
1592 
1593 	ip6 = mtod(m, struct ip6_hdr *);
1594 	nxt = ip6->ip6_nxt;
1595 	len = sizeof(struct ip6_hdr);
1596 	nlen = 0;
1597 	while (len < off) {
1598 		m_copydata(m, len, sizeof(ip6e), (caddr_t)&ip6e);
1599 		switch (nxt) {
1600 		case IPPROTO_FRAGMENT:
1601 			nlen = sizeof(struct ip6_frag);
1602 			break;
1603 		case IPPROTO_AH:
1604 			nlen = (ip6e.ip6e_len + 2) << 2;
1605 			break;
1606 		default:
1607 			nlen = (ip6e.ip6e_len + 1) << 3;
1608 		}
1609 		len += nlen;
1610 		nxt = ip6e.ip6e_nxt;
1611 	}
1612 	return (len - nlen);
1613 }
1614 
1615 /*
1616  * get next header offset.  m will be retained.
1617  */
1618 int
1619 ip6_nexthdr(const struct mbuf *m, int off, int proto, int *nxtp)
1620 {
1621 	struct ip6_hdr ip6;
1622 	struct ip6_ext ip6e;
1623 	struct ip6_frag fh;
1624 
1625 	/* just in case */
1626 	if (m == NULL)
1627 		panic("ip6_nexthdr: m == NULL");
1628 	if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off)
1629 		return -1;
1630 
1631 	switch (proto) {
1632 	case IPPROTO_IPV6:
1633 		if (m->m_pkthdr.len < off + sizeof(ip6))
1634 			return -1;
1635 		m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6);
1636 		if (nxtp)
1637 			*nxtp = ip6.ip6_nxt;
1638 		off += sizeof(ip6);
1639 		return off;
1640 
1641 	case IPPROTO_FRAGMENT:
1642 		/*
1643 		 * terminate parsing if it is not the first fragment,
1644 		 * it does not make sense to parse through it.
1645 		 */
1646 		if (m->m_pkthdr.len < off + sizeof(fh))
1647 			return -1;
1648 		m_copydata(m, off, sizeof(fh), (caddr_t)&fh);
1649 		/* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */
1650 		if (fh.ip6f_offlg & IP6F_OFF_MASK)
1651 			return -1;
1652 		if (nxtp)
1653 			*nxtp = fh.ip6f_nxt;
1654 		off += sizeof(struct ip6_frag);
1655 		return off;
1656 
1657 	case IPPROTO_AH:
1658 		if (m->m_pkthdr.len < off + sizeof(ip6e))
1659 			return -1;
1660 		m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1661 		if (nxtp)
1662 			*nxtp = ip6e.ip6e_nxt;
1663 		off += (ip6e.ip6e_len + 2) << 2;
1664 		return off;
1665 
1666 	case IPPROTO_HOPOPTS:
1667 	case IPPROTO_ROUTING:
1668 	case IPPROTO_DSTOPTS:
1669 		if (m->m_pkthdr.len < off + sizeof(ip6e))
1670 			return -1;
1671 		m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1672 		if (nxtp)
1673 			*nxtp = ip6e.ip6e_nxt;
1674 		off += (ip6e.ip6e_len + 1) << 3;
1675 		return off;
1676 
1677 	case IPPROTO_NONE:
1678 	case IPPROTO_ESP:
1679 	case IPPROTO_IPCOMP:
1680 		/* give up */
1681 		return -1;
1682 
1683 	default:
1684 		return -1;
1685 	}
1686 
1687 	/* NOTREACHED */
1688 }
1689 
1690 /*
1691  * get offset for the last header in the chain.  m will be kept untainted.
1692  */
1693 int
1694 ip6_lasthdr(const struct mbuf *m, int off, int proto, int *nxtp)
1695 {
1696 	int newoff;
1697 	int nxt;
1698 
1699 	if (!nxtp) {
1700 		nxt = -1;
1701 		nxtp = &nxt;
1702 	}
1703 	while (1) {
1704 		newoff = ip6_nexthdr(m, off, proto, nxtp);
1705 		if (newoff < 0)
1706 			return off;
1707 		else if (newoff < off)
1708 			return -1;	/* invalid */
1709 		else if (newoff == off)
1710 			return newoff;
1711 
1712 		off = newoff;
1713 		proto = *nxtp;
1714 	}
1715 }
1716 
1717 /*
1718  * System control for IP6
1719  */
1720 
1721 u_char	inet6ctlerrmap[PRC_NCMDS] = {
1722 	0,		0,		0,		0,
1723 	0,		EMSGSIZE,	EHOSTDOWN,	EHOSTUNREACH,
1724 	EHOSTUNREACH,	EHOSTUNREACH,	ECONNREFUSED,	ECONNREFUSED,
1725 	EMSGSIZE,	EHOSTUNREACH,	0,		0,
1726 	0,		0,		EHOSTUNREACH,	0,
1727 	ENOPROTOOPT,	ECONNREFUSED
1728 };
1729