xref: /freebsd/sys/netinet6/icmp6.c (revision c96ae1968a6ab7056427a739bce81bf07447c2d4)
1 /*	$FreeBSD$	*/
2 /*	$KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $	*/
3 
4 /*-
5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*-
34  * Copyright (c) 1982, 1986, 1988, 1993
35  *	The Regents of the University of California.  All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 4. Neither the name of the University nor the names of its contributors
46  *    may be used to endorse or promote products derived from this software
47  *    without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  *
61  *	@(#)ip_icmp.c	8.2 (Berkeley) 1/4/94
62  */
63 
64 #include "opt_inet.h"
65 #include "opt_inet6.h"
66 #include "opt_ipsec.h"
67 
68 #include <sys/param.h>
69 #include <sys/domain.h>
70 #include <sys/kernel.h>
71 #include <sys/lock.h>
72 #include <sys/malloc.h>
73 #include <sys/mbuf.h>
74 #include <sys/protosw.h>
75 #include <sys/signalvar.h>
76 #include <sys/socket.h>
77 #include <sys/socketvar.h>
78 #include <sys/sx.h>
79 #include <sys/syslog.h>
80 #include <sys/systm.h>
81 #include <sys/time.h>
82 
83 #include <net/if.h>
84 #include <net/if_dl.h>
85 #include <net/if_types.h>
86 #include <net/route.h>
87 
88 #include <netinet/in.h>
89 #include <netinet/in_pcb.h>
90 #include <netinet/in_var.h>
91 #include <netinet/ip6.h>
92 #include <netinet/icmp6.h>
93 #include <netinet/tcp_var.h>
94 #include <netinet6/in6_ifattach.h>
95 #include <netinet6/in6_pcb.h>
96 #include <netinet6/ip6protosw.h>
97 #include <netinet6/ip6_var.h>
98 #include <netinet6/scope6_var.h>
99 #include <netinet6/mld6_var.h>
100 #include <netinet6/nd6.h>
101 
102 #ifdef IPSEC
103 #include <netinet6/ipsec.h>
104 #include <netkey/key.h>
105 #endif
106 
107 #ifdef FAST_IPSEC
108 #include <netipsec/ipsec.h>
109 #include <netipsec/key.h>
110 #endif
111 
112 extern struct domain inet6domain;
113 
114 struct icmp6stat icmp6stat;
115 
116 extern struct inpcbinfo ripcbinfo;
117 extern struct inpcbhead ripcb;
118 extern int icmp6errppslim;
119 static int icmp6errpps_count = 0;
120 static struct timeval icmp6errppslim_last;
121 extern int icmp6_nodeinfo;
122 
123 static void icmp6_errcount __P((struct icmp6errstat *, int, int));
124 static int icmp6_rip6_input __P((struct mbuf **, int));
125 static int icmp6_ratelimit __P((const struct in6_addr *, const int, const int));
126 static const char *icmp6_redirect_diag __P((struct in6_addr *,
127 	struct in6_addr *, struct in6_addr *));
128 static struct mbuf *ni6_input __P((struct mbuf *, int));
129 static struct mbuf *ni6_nametodns __P((const char *, int, int));
130 static int ni6_dnsmatch __P((const char *, int, const char *, int));
131 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *,
132 			  struct ifnet **, struct in6_addr *));
133 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
134 				struct ifnet *, int));
135 static int icmp6_notify_error __P((struct mbuf **, int, int, int));
136 
137 
138 void
139 icmp6_init()
140 {
141 	mld6_init();
142 }
143 
144 static void
145 icmp6_errcount(stat, type, code)
146 	struct icmp6errstat *stat;
147 	int type, code;
148 {
149 	switch (type) {
150 	case ICMP6_DST_UNREACH:
151 		switch (code) {
152 		case ICMP6_DST_UNREACH_NOROUTE:
153 			stat->icp6errs_dst_unreach_noroute++;
154 			return;
155 		case ICMP6_DST_UNREACH_ADMIN:
156 			stat->icp6errs_dst_unreach_admin++;
157 			return;
158 		case ICMP6_DST_UNREACH_BEYONDSCOPE:
159 			stat->icp6errs_dst_unreach_beyondscope++;
160 			return;
161 		case ICMP6_DST_UNREACH_ADDR:
162 			stat->icp6errs_dst_unreach_addr++;
163 			return;
164 		case ICMP6_DST_UNREACH_NOPORT:
165 			stat->icp6errs_dst_unreach_noport++;
166 			return;
167 		}
168 		break;
169 	case ICMP6_PACKET_TOO_BIG:
170 		stat->icp6errs_packet_too_big++;
171 		return;
172 	case ICMP6_TIME_EXCEEDED:
173 		switch (code) {
174 		case ICMP6_TIME_EXCEED_TRANSIT:
175 			stat->icp6errs_time_exceed_transit++;
176 			return;
177 		case ICMP6_TIME_EXCEED_REASSEMBLY:
178 			stat->icp6errs_time_exceed_reassembly++;
179 			return;
180 		}
181 		break;
182 	case ICMP6_PARAM_PROB:
183 		switch (code) {
184 		case ICMP6_PARAMPROB_HEADER:
185 			stat->icp6errs_paramprob_header++;
186 			return;
187 		case ICMP6_PARAMPROB_NEXTHEADER:
188 			stat->icp6errs_paramprob_nextheader++;
189 			return;
190 		case ICMP6_PARAMPROB_OPTION:
191 			stat->icp6errs_paramprob_option++;
192 			return;
193 		}
194 		break;
195 	case ND_REDIRECT:
196 		stat->icp6errs_redirect++;
197 		return;
198 	}
199 	stat->icp6errs_unknown++;
200 }
201 
202 /*
203  * A wrapper function for icmp6_error() necessary when the erroneous packet
204  * may not contain enough scope zone information.
205  */
206 void
207 icmp6_error2(m, type, code, param, ifp)
208 	struct mbuf *m;
209 	int type, code, param;
210 	struct ifnet *ifp;
211 {
212 	struct ip6_hdr *ip6;
213 
214 	if (ifp == NULL)
215 		return;
216 
217 #ifndef PULLDOWN_TEST
218 	IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
219 #else
220 	if (m->m_len < sizeof(struct ip6_hdr)) {
221 		m = m_pullup(m, sizeof(struct ip6_hdr));
222 		if (m == NULL)
223 			return;
224 	}
225 #endif
226 
227 	ip6 = mtod(m, struct ip6_hdr *);
228 
229 	if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
230 		return;
231 	if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
232 		return;
233 
234 	icmp6_error(m, type, code, param);
235 }
236 
237 /*
238  * Generate an error packet of type error in response to bad IP6 packet.
239  */
240 void
241 icmp6_error(m, type, code, param)
242 	struct mbuf *m;
243 	int type, code, param;
244 {
245 	struct ip6_hdr *oip6, *nip6;
246 	struct icmp6_hdr *icmp6;
247 	u_int preplen;
248 	int off;
249 	int nxt;
250 
251 	icmp6stat.icp6s_error++;
252 
253 	/* count per-type-code statistics */
254 	icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code);
255 
256 #ifdef M_DECRYPTED	/*not openbsd*/
257 	if (m->m_flags & M_DECRYPTED) {
258 		icmp6stat.icp6s_canterror++;
259 		goto freeit;
260 	}
261 #endif
262 
263 #ifndef PULLDOWN_TEST
264 	IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
265 #else
266 	if (m->m_len < sizeof(struct ip6_hdr)) {
267 		m = m_pullup(m, sizeof(struct ip6_hdr));
268 		if (m == NULL)
269 			return;
270 	}
271 #endif
272 	oip6 = mtod(m, struct ip6_hdr *);
273 
274 	/*
275 	 * If the destination address of the erroneous packet is a multicast
276 	 * address, or the packet was sent using link-layer multicast,
277 	 * we should basically suppress sending an error (RFC 2463, Section
278 	 * 2.4).
279 	 * We have two exceptions (the item e.2 in that section):
280 	 * - the Pakcet Too Big message can be sent for path MTU discovery.
281 	 * - the Parameter Problem Message that can be allowed an icmp6 error
282 	 *   in the option type field.  This check has been done in
283 	 *   ip6_unknown_opt(), so we can just check the type and code.
284 	 */
285 	if ((m->m_flags & (M_BCAST|M_MCAST) ||
286 	     IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
287 	    (type != ICMP6_PACKET_TOO_BIG &&
288 	     (type != ICMP6_PARAM_PROB ||
289 	      code != ICMP6_PARAMPROB_OPTION)))
290 		goto freeit;
291 
292 	/*
293 	 * RFC 2463, 2.4 (e.5): source address check.
294 	 * XXX: the case of anycast source?
295 	 */
296 	if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
297 	    IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
298 		goto freeit;
299 
300 	/*
301 	 * If we are about to send ICMPv6 against ICMPv6 error/redirect,
302 	 * don't do it.
303 	 */
304 	nxt = -1;
305 	off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
306 	if (off >= 0 && nxt == IPPROTO_ICMPV6) {
307 		struct icmp6_hdr *icp;
308 
309 #ifndef PULLDOWN_TEST
310 		IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
311 		icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
312 #else
313 		IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
314 			sizeof(*icp));
315 		if (icp == NULL) {
316 			icmp6stat.icp6s_tooshort++;
317 			return;
318 		}
319 #endif
320 		if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
321 		    icp->icmp6_type == ND_REDIRECT) {
322 			/*
323 			 * ICMPv6 error
324 			 * Special case: for redirect (which is
325 			 * informational) we must not send icmp6 error.
326 			 */
327 			icmp6stat.icp6s_canterror++;
328 			goto freeit;
329 		} else {
330 			/* ICMPv6 informational - send the error */
331 		}
332 	} else {
333 		/* non-ICMPv6 - send the error */
334 	}
335 
336 	oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
337 
338 	/* Finally, do rate limitation check. */
339 	if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
340 		icmp6stat.icp6s_toofreq++;
341 		goto freeit;
342 	}
343 
344 	/*
345 	 * OK, ICMP6 can be generated.
346 	 */
347 
348 	if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
349 		m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
350 
351 	preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
352 	M_PREPEND(m, preplen, M_DONTWAIT);
353 	if (m && m->m_len < preplen)
354 		m = m_pullup(m, preplen);
355 	if (m == NULL) {
356 		nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
357 		return;
358 	}
359 
360 	nip6 = mtod(m, struct ip6_hdr *);
361 	nip6->ip6_src  = oip6->ip6_src;
362 	nip6->ip6_dst  = oip6->ip6_dst;
363 
364 	in6_clearscope(&oip6->ip6_src);
365 	in6_clearscope(&oip6->ip6_dst);
366 
367 	icmp6 = (struct icmp6_hdr *)(nip6 + 1);
368 	icmp6->icmp6_type = type;
369 	icmp6->icmp6_code = code;
370 	icmp6->icmp6_pptr = htonl((u_int32_t)param);
371 
372 	/*
373 	 * icmp6_reflect() is designed to be in the input path.
374 	 * icmp6_error() can be called from both input and output path,
375 	 * and if we are in output path rcvif could contain bogus value.
376 	 * clear m->m_pkthdr.rcvif for safety, we should have enough scope
377 	 * information in ip header (nip6).
378 	 */
379 	m->m_pkthdr.rcvif = NULL;
380 
381 	icmp6stat.icp6s_outhist[type]++;
382 	icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
383 
384 	return;
385 
386   freeit:
387 	/*
388 	 * If we can't tell whether or not we can generate ICMP6, free it.
389 	 */
390 	m_freem(m);
391 }
392 
393 /*
394  * Process a received ICMP6 message.
395  */
396 int
397 icmp6_input(mp, offp, proto)
398 	struct mbuf **mp;
399 	int *offp, proto;
400 {
401 	struct mbuf *m = *mp, *n;
402 	struct ip6_hdr *ip6, *nip6;
403 	struct icmp6_hdr *icmp6, *nicmp6;
404 	int off = *offp;
405 	int icmp6len = m->m_pkthdr.len - *offp;
406 	int code, sum, noff;
407 	char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
408 
409 #ifndef PULLDOWN_TEST
410 	IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
411 	/* m might change if M_LOOP.  So, call mtod after this */
412 #endif
413 
414 	/*
415 	 * Locate icmp6 structure in mbuf, and check
416 	 * that not corrupted and of at least minimum length
417 	 */
418 
419 	ip6 = mtod(m, struct ip6_hdr *);
420 	if (icmp6len < sizeof(struct icmp6_hdr)) {
421 		icmp6stat.icp6s_tooshort++;
422 		goto freeit;
423 	}
424 
425 	/*
426 	 * calculate the checksum
427 	 */
428 #ifndef PULLDOWN_TEST
429 	icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
430 #else
431 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
432 	if (icmp6 == NULL) {
433 		icmp6stat.icp6s_tooshort++;
434 		return IPPROTO_DONE;
435 	}
436 #endif
437 	code = icmp6->icmp6_code;
438 
439 	if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
440 		nd6log((LOG_ERR,
441 		    "ICMP6 checksum error(%d|%x) %s\n",
442 		    icmp6->icmp6_type, sum,
443 		    ip6_sprintf(ip6bufs, &ip6->ip6_src)));
444 		icmp6stat.icp6s_checksum++;
445 		goto freeit;
446 	}
447 
448 	if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
449 		/*
450 		 * Deliver very specific ICMP6 type only.
451 		 * This is important to deliver TOOBIG.  Otherwise PMTUD
452 		 * will not work.
453 		 */
454 		switch (icmp6->icmp6_type) {
455 		case ICMP6_DST_UNREACH:
456 		case ICMP6_PACKET_TOO_BIG:
457 		case ICMP6_TIME_EXCEEDED:
458 			break;
459 		default:
460 			goto freeit;
461 		}
462 	}
463 
464 	icmp6stat.icp6s_inhist[icmp6->icmp6_type]++;
465 	icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg);
466 	if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
467 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
468 
469 	switch (icmp6->icmp6_type) {
470 	case ICMP6_DST_UNREACH:
471 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach);
472 		switch (code) {
473 		case ICMP6_DST_UNREACH_NOROUTE:
474 			code = PRC_UNREACH_NET;
475 			break;
476 		case ICMP6_DST_UNREACH_ADMIN:
477 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib);
478 			code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
479 			break;
480 		case ICMP6_DST_UNREACH_ADDR:
481 			code = PRC_HOSTDEAD;
482 			break;
483 		case ICMP6_DST_UNREACH_BEYONDSCOPE:
484 			/* I mean "source address was incorrect." */
485 			code = PRC_PARAMPROB;
486 			break;
487 		case ICMP6_DST_UNREACH_NOPORT:
488 			code = PRC_UNREACH_PORT;
489 			break;
490 		default:
491 			goto badcode;
492 		}
493 		goto deliver;
494 		break;
495 
496 	case ICMP6_PACKET_TOO_BIG:
497 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig);
498 
499 		/* validation is made in icmp6_mtudisc_update */
500 
501 		code = PRC_MSGSIZE;
502 
503 		/*
504 		 * Updating the path MTU will be done after examining
505 		 * intermediate extension headers.
506 		 */
507 		goto deliver;
508 		break;
509 
510 	case ICMP6_TIME_EXCEEDED:
511 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed);
512 		switch (code) {
513 		case ICMP6_TIME_EXCEED_TRANSIT:
514 			code = PRC_TIMXCEED_INTRANS;
515 			break;
516 		case ICMP6_TIME_EXCEED_REASSEMBLY:
517 			code = PRC_TIMXCEED_REASS;
518 			break;
519 		default:
520 			goto badcode;
521 		}
522 		goto deliver;
523 		break;
524 
525 	case ICMP6_PARAM_PROB:
526 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob);
527 		switch (code) {
528 		case ICMP6_PARAMPROB_NEXTHEADER:
529 			code = PRC_UNREACH_PROTOCOL;
530 			break;
531 		case ICMP6_PARAMPROB_HEADER:
532 		case ICMP6_PARAMPROB_OPTION:
533 			code = PRC_PARAMPROB;
534 			break;
535 		default:
536 			goto badcode;
537 		}
538 		goto deliver;
539 		break;
540 
541 	case ICMP6_ECHO_REQUEST:
542 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo);
543 		if (code != 0)
544 			goto badcode;
545 		if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
546 			/* Give up remote */
547 			break;
548 		}
549 		if ((n->m_flags & M_EXT) != 0
550 		 || n->m_len < off + sizeof(struct icmp6_hdr)) {
551 			struct mbuf *n0 = n;
552 			const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
553 			int n0len;
554 
555 			MGETHDR(n, M_DONTWAIT, n0->m_type);
556 			n0len = n0->m_pkthdr.len;	/* save for use below */
557 			if (n)
558 				M_MOVE_PKTHDR(n, n0);
559 			if (n && maxlen >= MHLEN) {
560 				MCLGET(n, M_DONTWAIT);
561 				if ((n->m_flags & M_EXT) == 0) {
562 					m_free(n);
563 					n = NULL;
564 				}
565 			}
566 			if (n == NULL) {
567 				/* Give up remote */
568 				m_freem(n0);
569 				break;
570 			}
571 			/*
572 			 * Copy IPv6 and ICMPv6 only.
573 			 */
574 			nip6 = mtod(n, struct ip6_hdr *);
575 			bcopy(ip6, nip6, sizeof(struct ip6_hdr));
576 			nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
577 			bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
578 			noff = sizeof(struct ip6_hdr);
579 			/* new mbuf contains only ipv6+icmpv6 headers */
580 			n->m_len = noff + sizeof(struct icmp6_hdr);
581 			/*
582 			 * Adjust mbuf.  ip6_plen will be adjusted in
583 			 * ip6_output().
584 			 */
585 			m_adj(n0, off + sizeof(struct icmp6_hdr));
586 			/* recalculate complete packet size */
587 			n->m_pkthdr.len = n0len + (noff - off);
588 			n->m_next = n0;
589 		} else {
590 			nip6 = mtod(n, struct ip6_hdr *);
591 			IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
592 			    sizeof(*nicmp6));
593 			noff = off;
594 		}
595 		nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
596 		nicmp6->icmp6_code = 0;
597 		if (n) {
598 			icmp6stat.icp6s_reflect++;
599 			icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++;
600 			icmp6_reflect(n, noff);
601 		}
602 		break;
603 
604 	case ICMP6_ECHO_REPLY:
605 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply);
606 		if (code != 0)
607 			goto badcode;
608 		break;
609 
610 	case MLD_LISTENER_QUERY:
611 	case MLD_LISTENER_REPORT:
612 		if (icmp6len < sizeof(struct mld_hdr))
613 			goto badlen;
614 		if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */
615 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery);
616 		else
617 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport);
618 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
619 			/* give up local */
620 			mld6_input(m, off);
621 			m = NULL;
622 			goto freeit;
623 		}
624 		mld6_input(n, off);
625 		/* m stays. */
626 		break;
627 
628 	case MLD_LISTENER_DONE:
629 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone);
630 		if (icmp6len < sizeof(struct mld_hdr))	/* necessary? */
631 			goto badlen;
632 		break;		/* nothing to be done in kernel */
633 
634 	case MLD_MTRACE_RESP:
635 	case MLD_MTRACE:
636 		/* XXX: these two are experimental.  not officially defined. */
637 		/* XXX: per-interface statistics? */
638 		break;		/* just pass it to applications */
639 
640 	case ICMP6_WRUREQUEST:	/* ICMP6_FQDN_QUERY */
641 	    {
642 		enum { WRU, FQDN } mode;
643 
644 		if (!icmp6_nodeinfo)
645 			break;
646 
647 		if (icmp6len == sizeof(struct icmp6_hdr) + 4)
648 			mode = WRU;
649 		else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
650 			mode = FQDN;
651 		else
652 			goto badlen;
653 
654 #define hostnamelen	strlen(hostname)
655 		if (mode == FQDN) {
656 #ifndef PULLDOWN_TEST
657 			IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
658 			    IPPROTO_DONE);
659 #endif
660 			n = m_copy(m, 0, M_COPYALL);
661 			if (n)
662 				n = ni6_input(n, off);
663 			/* XXX meaningless if n == NULL */
664 			noff = sizeof(struct ip6_hdr);
665 		} else {
666 			u_char *p;
667 			int maxlen, maxhlen;
668 
669 			if ((icmp6_nodeinfo & 5) != 5)
670 				break;
671 
672 			if (code != 0)
673 				goto badcode;
674 			maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
675 			if (maxlen >= MCLBYTES) {
676 				/* Give up remote */
677 				break;
678 			}
679 			MGETHDR(n, M_DONTWAIT, m->m_type);
680 			if (n && maxlen > MHLEN) {
681 				MCLGET(n, M_DONTWAIT);
682 				if ((n->m_flags & M_EXT) == 0) {
683 					m_free(n);
684 					n = NULL;
685 				}
686 			}
687 			if (!m_dup_pkthdr(n, m, M_DONTWAIT)) {
688 				/*
689 				 * Previous code did a blind M_COPY_PKTHDR
690 				 * and said "just for rcvif".  If true, then
691 				 * we could tolerate the dup failing (due to
692 				 * the deep copy of the tag chain).  For now
693 				 * be conservative and just fail.
694 				 */
695 				m_free(n);
696 				n = NULL;
697 			}
698 			if (n == NULL) {
699 				/* Give up remote */
700 				break;
701 			}
702 			n->m_pkthdr.rcvif = NULL;
703 			n->m_len = 0;
704 			maxhlen = M_TRAILINGSPACE(n) - maxlen;
705 			if (maxhlen > hostnamelen)
706 				maxhlen = hostnamelen;
707 			/*
708 			 * Copy IPv6 and ICMPv6 only.
709 			 */
710 			nip6 = mtod(n, struct ip6_hdr *);
711 			bcopy(ip6, nip6, sizeof(struct ip6_hdr));
712 			nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
713 			bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
714 			p = (u_char *)(nicmp6 + 1);
715 			bzero(p, 4);
716 			bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */
717 			noff = sizeof(struct ip6_hdr);
718 			n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
719 				sizeof(struct icmp6_hdr) + 4 + maxhlen;
720 			nicmp6->icmp6_type = ICMP6_WRUREPLY;
721 			nicmp6->icmp6_code = 0;
722 		}
723 #undef hostnamelen
724 		if (n) {
725 			icmp6stat.icp6s_reflect++;
726 			icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++;
727 			icmp6_reflect(n, noff);
728 		}
729 		break;
730 	    }
731 
732 	case ICMP6_WRUREPLY:
733 		if (code != 0)
734 			goto badcode;
735 		break;
736 
737 	case ND_ROUTER_SOLICIT:
738 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit);
739 		if (code != 0)
740 			goto badcode;
741 		if (icmp6len < sizeof(struct nd_router_solicit))
742 			goto badlen;
743 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
744 			/* give up local */
745 			nd6_rs_input(m, off, icmp6len);
746 			m = NULL;
747 			goto freeit;
748 		}
749 		nd6_rs_input(n, off, icmp6len);
750 		/* m stays. */
751 		break;
752 
753 	case ND_ROUTER_ADVERT:
754 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert);
755 		if (code != 0)
756 			goto badcode;
757 		if (icmp6len < sizeof(struct nd_router_advert))
758 			goto badlen;
759 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
760 			/* give up local */
761 			nd6_ra_input(m, off, icmp6len);
762 			m = NULL;
763 			goto freeit;
764 		}
765 		nd6_ra_input(n, off, icmp6len);
766 		/* m stays. */
767 		break;
768 
769 	case ND_NEIGHBOR_SOLICIT:
770 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit);
771 		if (code != 0)
772 			goto badcode;
773 		if (icmp6len < sizeof(struct nd_neighbor_solicit))
774 			goto badlen;
775 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
776 			/* give up local */
777 			nd6_ns_input(m, off, icmp6len);
778 			m = NULL;
779 			goto freeit;
780 		}
781 		nd6_ns_input(n, off, icmp6len);
782 		/* m stays. */
783 		break;
784 
785 	case ND_NEIGHBOR_ADVERT:
786 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert);
787 		if (code != 0)
788 			goto badcode;
789 		if (icmp6len < sizeof(struct nd_neighbor_advert))
790 			goto badlen;
791 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
792 			/* give up local */
793 			nd6_na_input(m, off, icmp6len);
794 			m = NULL;
795 			goto freeit;
796 		}
797 		nd6_na_input(n, off, icmp6len);
798 		/* m stays. */
799 		break;
800 
801 	case ND_REDIRECT:
802 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect);
803 		if (code != 0)
804 			goto badcode;
805 		if (icmp6len < sizeof(struct nd_redirect))
806 			goto badlen;
807 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
808 			/* give up local */
809 			icmp6_redirect_input(m, off);
810 			m = NULL;
811 			goto freeit;
812 		}
813 		icmp6_redirect_input(n, off);
814 		/* m stays. */
815 		break;
816 
817 	case ICMP6_ROUTER_RENUMBERING:
818 		if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
819 		    code != ICMP6_ROUTER_RENUMBERING_RESULT)
820 			goto badcode;
821 		if (icmp6len < sizeof(struct icmp6_router_renum))
822 			goto badlen;
823 		break;
824 
825 	default:
826 		nd6log((LOG_DEBUG,
827 		    "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
828 		    icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
829 		    ip6_sprintf(ip6bufd, &ip6->ip6_dst),
830 		    m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0));
831 		if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
832 			/* ICMPv6 error: MUST deliver it by spec... */
833 			code = PRC_NCMDS;
834 			/* deliver */
835 		} else {
836 			/* ICMPv6 informational: MUST not deliver */
837 			break;
838 		}
839 	deliver:
840 		if (icmp6_notify_error(&m, off, icmp6len, code)) {
841 			/* In this case, m should've been freed. */
842 			return (IPPROTO_DONE);
843 		}
844 		break;
845 
846 	badcode:
847 		icmp6stat.icp6s_badcode++;
848 		break;
849 
850 	badlen:
851 		icmp6stat.icp6s_badlen++;
852 		break;
853 	}
854 
855 	/* deliver the packet to appropriate sockets */
856 	icmp6_rip6_input(&m, *offp);
857 
858 	return IPPROTO_DONE;
859 
860  freeit:
861 	m_freem(m);
862 	return IPPROTO_DONE;
863 }
864 
865 static int
866 icmp6_notify_error(mp, off, icmp6len, code)
867 	struct mbuf **mp;
868 	int off, icmp6len, code;
869 {
870 	struct mbuf *m = *mp;
871 	struct icmp6_hdr *icmp6;
872 	struct ip6_hdr *eip6;
873 	u_int32_t notifymtu;
874 	struct sockaddr_in6 icmp6src, icmp6dst;
875 
876 	if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
877 		icmp6stat.icp6s_tooshort++;
878 		goto freeit;
879 	}
880 #ifndef PULLDOWN_TEST
881 	IP6_EXTHDR_CHECK(m, off,
882 	    sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
883 	icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
884 #else
885 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
886 	    sizeof(*icmp6) + sizeof(struct ip6_hdr));
887 	if (icmp6 == NULL) {
888 		icmp6stat.icp6s_tooshort++;
889 		return (-1);
890 	}
891 #endif
892 	eip6 = (struct ip6_hdr *)(icmp6 + 1);
893 
894 	/* Detect the upper level protocol */
895 	{
896 		void (*ctlfunc) __P((int, struct sockaddr *, void *));
897 		u_int8_t nxt = eip6->ip6_nxt;
898 		int eoff = off + sizeof(struct icmp6_hdr) +
899 		    sizeof(struct ip6_hdr);
900 		struct ip6ctlparam ip6cp;
901 		struct in6_addr *finaldst = NULL;
902 		int icmp6type = icmp6->icmp6_type;
903 		struct ip6_frag *fh;
904 		struct ip6_rthdr *rth;
905 		struct ip6_rthdr0 *rth0;
906 		int rthlen;
907 
908 		while (1) { /* XXX: should avoid infinite loop explicitly? */
909 			struct ip6_ext *eh;
910 
911 			switch (nxt) {
912 			case IPPROTO_HOPOPTS:
913 			case IPPROTO_DSTOPTS:
914 			case IPPROTO_AH:
915 #ifndef PULLDOWN_TEST
916 				IP6_EXTHDR_CHECK(m, 0,
917 				    eoff + sizeof(struct ip6_ext), -1);
918 				eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
919 #else
920 				IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
921 				    eoff, sizeof(*eh));
922 				if (eh == NULL) {
923 					icmp6stat.icp6s_tooshort++;
924 					return (-1);
925 				}
926 #endif
927 
928 				if (nxt == IPPROTO_AH)
929 					eoff += (eh->ip6e_len + 2) << 2;
930 				else
931 					eoff += (eh->ip6e_len + 1) << 3;
932 				nxt = eh->ip6e_nxt;
933 				break;
934 			case IPPROTO_ROUTING:
935 				/*
936 				 * When the erroneous packet contains a
937 				 * routing header, we should examine the
938 				 * header to determine the final destination.
939 				 * Otherwise, we can't properly update
940 				 * information that depends on the final
941 				 * destination (e.g. path MTU).
942 				 */
943 #ifndef PULLDOWN_TEST
944 				IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
945 				rth = (struct ip6_rthdr *)
946 				    (mtod(m, caddr_t) + eoff);
947 #else
948 				IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
949 				    eoff, sizeof(*rth));
950 				if (rth == NULL) {
951 					icmp6stat.icp6s_tooshort++;
952 					return (-1);
953 				}
954 #endif
955 				rthlen = (rth->ip6r_len + 1) << 3;
956 				/*
957 				 * XXX: currently there is no
958 				 * officially defined type other
959 				 * than type-0.
960 				 * Note that if the segment left field
961 				 * is 0, all intermediate hops must
962 				 * have been passed.
963 				 */
964 				if (rth->ip6r_segleft &&
965 				    rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
966 					int hops;
967 
968 #ifndef PULLDOWN_TEST
969 					IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
970 					rth0 = (struct ip6_rthdr0 *)
971 					    (mtod(m, caddr_t) + eoff);
972 #else
973 					IP6_EXTHDR_GET(rth0,
974 					    struct ip6_rthdr0 *, m,
975 					    eoff, rthlen);
976 					if (rth0 == NULL) {
977 						icmp6stat.icp6s_tooshort++;
978 						return (-1);
979 					}
980 #endif
981 					/* just ignore a bogus header */
982 					if ((rth0->ip6r0_len % 2) == 0 &&
983 					    (hops = rth0->ip6r0_len/2))
984 						finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
985 				}
986 				eoff += rthlen;
987 				nxt = rth->ip6r_nxt;
988 				break;
989 			case IPPROTO_FRAGMENT:
990 #ifndef PULLDOWN_TEST
991 				IP6_EXTHDR_CHECK(m, 0, eoff +
992 				    sizeof(struct ip6_frag), -1);
993 				fh = (struct ip6_frag *)(mtod(m, caddr_t) +
994 				    eoff);
995 #else
996 				IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
997 				    eoff, sizeof(*fh));
998 				if (fh == NULL) {
999 					icmp6stat.icp6s_tooshort++;
1000 					return (-1);
1001 				}
1002 #endif
1003 				/*
1004 				 * Data after a fragment header is meaningless
1005 				 * unless it is the first fragment, but
1006 				 * we'll go to the notify label for path MTU
1007 				 * discovery.
1008 				 */
1009 				if (fh->ip6f_offlg & IP6F_OFF_MASK)
1010 					goto notify;
1011 
1012 				eoff += sizeof(struct ip6_frag);
1013 				nxt = fh->ip6f_nxt;
1014 				break;
1015 			default:
1016 				/*
1017 				 * This case includes ESP and the No Next
1018 				 * Header.  In such cases going to the notify
1019 				 * label does not have any meaning
1020 				 * (i.e. ctlfunc will be NULL), but we go
1021 				 * anyway since we might have to update
1022 				 * path MTU information.
1023 				 */
1024 				goto notify;
1025 			}
1026 		}
1027 	  notify:
1028 #ifndef PULLDOWN_TEST
1029 		icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1030 #else
1031 		IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1032 		    sizeof(*icmp6) + sizeof(struct ip6_hdr));
1033 		if (icmp6 == NULL) {
1034 			icmp6stat.icp6s_tooshort++;
1035 			return (-1);
1036 		}
1037 #endif
1038 
1039 		/*
1040 		 * retrieve parameters from the inner IPv6 header, and convert
1041 		 * them into sockaddr structures.
1042 		 * XXX: there is no guarantee that the source or destination
1043 		 * addresses of the inner packet are in the same scope as
1044 		 * the addresses of the icmp packet.  But there is no other
1045 		 * way to determine the zone.
1046 		 */
1047 		eip6 = (struct ip6_hdr *)(icmp6 + 1);
1048 
1049 		bzero(&icmp6dst, sizeof(icmp6dst));
1050 		icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1051 		icmp6dst.sin6_family = AF_INET6;
1052 		if (finaldst == NULL)
1053 			icmp6dst.sin6_addr = eip6->ip6_dst;
1054 		else
1055 			icmp6dst.sin6_addr = *finaldst;
1056 		if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1057 			goto freeit;
1058 		bzero(&icmp6src, sizeof(icmp6src));
1059 		icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1060 		icmp6src.sin6_family = AF_INET6;
1061 		icmp6src.sin6_addr = eip6->ip6_src;
1062 		if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1063 			goto freeit;
1064 		icmp6src.sin6_flowinfo =
1065 		    (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1066 
1067 		if (finaldst == NULL)
1068 			finaldst = &eip6->ip6_dst;
1069 		ip6cp.ip6c_m = m;
1070 		ip6cp.ip6c_icmp6 = icmp6;
1071 		ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1072 		ip6cp.ip6c_off = eoff;
1073 		ip6cp.ip6c_finaldst = finaldst;
1074 		ip6cp.ip6c_src = &icmp6src;
1075 		ip6cp.ip6c_nxt = nxt;
1076 
1077 		if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1078 			notifymtu = ntohl(icmp6->icmp6_mtu);
1079 			ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1080 			icmp6_mtudisc_update(&ip6cp, 1);	/*XXX*/
1081 		}
1082 
1083 		ctlfunc = (void (*) __P((int, struct sockaddr *, void *)))
1084 		    (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1085 		if (ctlfunc) {
1086 			(void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1087 			    &ip6cp);
1088 		}
1089 	}
1090 	*mp = m;
1091 	return (0);
1092 
1093   freeit:
1094 	m_freem(m);
1095 	return (-1);
1096 }
1097 
1098 void
1099 icmp6_mtudisc_update(ip6cp, validated)
1100 	struct ip6ctlparam *ip6cp;
1101 	int validated;
1102 {
1103 	struct in6_addr *dst = ip6cp->ip6c_finaldst;
1104 	struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1105 	struct mbuf *m = ip6cp->ip6c_m;	/* will be necessary for scope issue */
1106 	u_int mtu = ntohl(icmp6->icmp6_mtu);
1107 	struct in_conninfo inc;
1108 
1109 #if 0
1110 	/*
1111 	 * RFC2460 section 5, last paragraph.
1112 	 * even though minimum link MTU for IPv6 is IPV6_MMTU,
1113 	 * we may see ICMPv6 too big with mtu < IPV6_MMTU
1114 	 * due to packet translator in the middle.
1115 	 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1116 	 * special handling.
1117 	 */
1118 	if (mtu < IPV6_MMTU)
1119 		return;
1120 #endif
1121 
1122 	/*
1123 	 * we reject ICMPv6 too big with abnormally small value.
1124 	 * XXX what is the good definition of "abnormally small"?
1125 	 */
1126 	if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1127 		return;
1128 
1129 	if (!validated)
1130 		return;
1131 
1132 	bzero(&inc, sizeof(inc));
1133 	inc.inc_flags = 1; /* IPv6 */
1134 	inc.inc6_faddr = *dst;
1135 	if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1136 		return;
1137 
1138 	if (mtu < tcp_maxmtu6(&inc, NULL)) {
1139 		tcp_hc_updatemtu(&inc, mtu);
1140 		icmp6stat.icp6s_pmtuchg++;
1141 	}
1142 }
1143 
1144 /*
1145  * Process a Node Information Query packet, based on
1146  * draft-ietf-ipngwg-icmp-name-lookups-07.
1147  *
1148  * Spec incompatibilities:
1149  * - IPv6 Subject address handling
1150  * - IPv4 Subject address handling support missing
1151  * - Proxy reply (answer even if it's not for me)
1152  * - joins NI group address at in6_ifattach() time only, does not cope
1153  *   with hostname changes by sethostname(3)
1154  */
1155 #define hostnamelen	strlen(hostname)
1156 static struct mbuf *
1157 ni6_input(m, off)
1158 	struct mbuf *m;
1159 	int off;
1160 {
1161 	struct icmp6_nodeinfo *ni6, *nni6;
1162 	struct mbuf *n = NULL;
1163 	u_int16_t qtype;
1164 	int subjlen;
1165 	int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1166 	struct ni_reply_fqdn *fqdn;
1167 	int addrs;		/* for NI_QTYPE_NODEADDR */
1168 	struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1169 	struct in6_addr in6_subj; /* subject address */
1170 	struct ip6_hdr *ip6;
1171 	int oldfqdn = 0;	/* if 1, return pascal string (03 draft) */
1172 	char *subj = NULL;
1173 	struct in6_ifaddr *ia6 = NULL;
1174 
1175 	ip6 = mtod(m, struct ip6_hdr *);
1176 #ifndef PULLDOWN_TEST
1177 	ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1178 #else
1179 	IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1180 	if (ni6 == NULL) {
1181 		/* m is already reclaimed */
1182 		return (NULL);
1183 	}
1184 #endif
1185 
1186 	/*
1187 	 * Validate IPv6 destination address.
1188 	 *
1189 	 * The Responder must discard the Query without further processing
1190 	 * unless it is one of the Responder's unicast or anycast addresses, or
1191 	 * a link-local scope multicast address which the Responder has joined.
1192 	 * [icmp-name-lookups-08, Section 4.]
1193 	 */
1194 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1195 		if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1196 			goto bad;
1197 		/* else it's a link-local multicast, fine */
1198 	} else {		/* unicast or anycast */
1199 		if ((ia6 = ip6_getdstifaddr(m)) == NULL)
1200 			goto bad; /* XXX impossible */
1201 
1202 		if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1203 		    !(icmp6_nodeinfo & 4)) {
1204 			nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1205 				"a temporary address in %s:%d",
1206 			       __FILE__, __LINE__));
1207 			goto bad;
1208 		}
1209 	}
1210 
1211 	/* validate query Subject field. */
1212 	qtype = ntohs(ni6->ni_qtype);
1213 	subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1214 	switch (qtype) {
1215 	case NI_QTYPE_NOOP:
1216 	case NI_QTYPE_SUPTYPES:
1217 		/* 07 draft */
1218 		if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1219 			break;
1220 		/* FALLTHROUGH */
1221 	case NI_QTYPE_FQDN:
1222 	case NI_QTYPE_NODEADDR:
1223 	case NI_QTYPE_IPV4ADDR:
1224 		switch (ni6->ni_code) {
1225 		case ICMP6_NI_SUBJ_IPV6:
1226 #if ICMP6_NI_SUBJ_IPV6 != 0
1227 		case 0:
1228 #endif
1229 			/*
1230 			 * backward compatibility - try to accept 03 draft
1231 			 * format, where no Subject is present.
1232 			 */
1233 			if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1234 			    subjlen == 0) {
1235 				oldfqdn++;
1236 				break;
1237 			}
1238 #if ICMP6_NI_SUBJ_IPV6 != 0
1239 			if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1240 				goto bad;
1241 #endif
1242 
1243 			if (subjlen != sizeof(struct in6_addr))
1244 				goto bad;
1245 
1246 			/*
1247 			 * Validate Subject address.
1248 			 *
1249 			 * Not sure what exactly "address belongs to the node"
1250 			 * means in the spec, is it just unicast, or what?
1251 			 *
1252 			 * At this moment we consider Subject address as
1253 			 * "belong to the node" if the Subject address equals
1254 			 * to the IPv6 destination address; validation for
1255 			 * IPv6 destination address should have done enough
1256 			 * check for us.
1257 			 *
1258 			 * We do not do proxy at this moment.
1259 			 */
1260 			/* m_pulldown instead of copy? */
1261 			m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1262 			    subjlen, (caddr_t)&in6_subj);
1263 			if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1264 				goto bad;
1265 
1266 			subj = (char *)&in6_subj;
1267 			if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1268 				break;
1269 
1270 			/*
1271 			 * XXX if we are to allow other cases, we should really
1272 			 * be careful about scope here.
1273 			 * basically, we should disallow queries toward IPv6
1274 			 * destination X with subject Y,
1275 			 * if scope(X) > scope(Y).
1276 			 * if we allow scope(X) > scope(Y), it will result in
1277 			 * information leakage across scope boundary.
1278 			 */
1279 			goto bad;
1280 
1281 		case ICMP6_NI_SUBJ_FQDN:
1282 			/*
1283 			 * Validate Subject name with gethostname(3).
1284 			 *
1285 			 * The behavior may need some debate, since:
1286 			 * - we are not sure if the node has FQDN as
1287 			 *   hostname (returned by gethostname(3)).
1288 			 * - the code does wildcard match for truncated names.
1289 			 *   however, we are not sure if we want to perform
1290 			 *   wildcard match, if gethostname(3) side has
1291 			 *   truncated hostname.
1292 			 */
1293 			n = ni6_nametodns(hostname, hostnamelen, 0);
1294 			if (!n || n->m_next || n->m_len == 0)
1295 				goto bad;
1296 			IP6_EXTHDR_GET(subj, char *, m,
1297 			    off + sizeof(struct icmp6_nodeinfo), subjlen);
1298 			if (subj == NULL)
1299 				goto bad;
1300 			if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1301 			    n->m_len)) {
1302 				goto bad;
1303 			}
1304 			m_freem(n);
1305 			n = NULL;
1306 			break;
1307 
1308 		case ICMP6_NI_SUBJ_IPV4:	/* XXX: to be implemented? */
1309 		default:
1310 			goto bad;
1311 		}
1312 		break;
1313 	}
1314 
1315 	/* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1316 	switch (qtype) {
1317 	case NI_QTYPE_FQDN:
1318 		if ((icmp6_nodeinfo & 1) == 0)
1319 			goto bad;
1320 		break;
1321 	case NI_QTYPE_NODEADDR:
1322 	case NI_QTYPE_IPV4ADDR:
1323 		if ((icmp6_nodeinfo & 2) == 0)
1324 			goto bad;
1325 		break;
1326 	}
1327 
1328 	/* guess reply length */
1329 	switch (qtype) {
1330 	case NI_QTYPE_NOOP:
1331 		break;		/* no reply data */
1332 	case NI_QTYPE_SUPTYPES:
1333 		replylen += sizeof(u_int32_t);
1334 		break;
1335 	case NI_QTYPE_FQDN:
1336 		/* XXX will append an mbuf */
1337 		replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1338 		break;
1339 	case NI_QTYPE_NODEADDR:
1340 		addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1341 		if ((replylen += addrs * (sizeof(struct in6_addr) +
1342 		    sizeof(u_int32_t))) > MCLBYTES)
1343 			replylen = MCLBYTES; /* XXX: will truncate pkt later */
1344 		break;
1345 	case NI_QTYPE_IPV4ADDR:
1346 		/* unsupported - should respond with unknown Qtype? */
1347 		break;
1348 	default:
1349 		/*
1350 		 * XXX: We must return a reply with the ICMP6 code
1351 		 * `unknown Qtype' in this case.  However we regard the case
1352 		 * as an FQDN query for backward compatibility.
1353 		 * Older versions set a random value to this field,
1354 		 * so it rarely varies in the defined qtypes.
1355 		 * But the mechanism is not reliable...
1356 		 * maybe we should obsolete older versions.
1357 		 */
1358 		qtype = NI_QTYPE_FQDN;
1359 		/* XXX will append an mbuf */
1360 		replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1361 		oldfqdn++;
1362 		break;
1363 	}
1364 
1365 	/* allocate an mbuf to reply. */
1366 	MGETHDR(n, M_DONTWAIT, m->m_type);
1367 	if (n == NULL) {
1368 		m_freem(m);
1369 		return (NULL);
1370 	}
1371 	M_MOVE_PKTHDR(n, m); /* just for recvif */
1372 	if (replylen > MHLEN) {
1373 		if (replylen > MCLBYTES) {
1374 			/*
1375 			 * XXX: should we try to allocate more? But MCLBYTES
1376 			 * is probably much larger than IPV6_MMTU...
1377 			 */
1378 			goto bad;
1379 		}
1380 		MCLGET(n, M_DONTWAIT);
1381 		if ((n->m_flags & M_EXT) == 0) {
1382 			goto bad;
1383 		}
1384 	}
1385 	n->m_pkthdr.len = n->m_len = replylen;
1386 
1387 	/* copy mbuf header and IPv6 + Node Information base headers */
1388 	bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1389 	nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1390 	bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1391 
1392 	/* qtype dependent procedure */
1393 	switch (qtype) {
1394 	case NI_QTYPE_NOOP:
1395 		nni6->ni_code = ICMP6_NI_SUCCESS;
1396 		nni6->ni_flags = 0;
1397 		break;
1398 	case NI_QTYPE_SUPTYPES:
1399 	{
1400 		u_int32_t v;
1401 		nni6->ni_code = ICMP6_NI_SUCCESS;
1402 		nni6->ni_flags = htons(0x0000);	/* raw bitmap */
1403 		/* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1404 		v = (u_int32_t)htonl(0x0000000f);
1405 		bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1406 		break;
1407 	}
1408 	case NI_QTYPE_FQDN:
1409 		nni6->ni_code = ICMP6_NI_SUCCESS;
1410 		fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1411 		    sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1412 		nni6->ni_flags = 0; /* XXX: meaningless TTL */
1413 		fqdn->ni_fqdn_ttl = 0;	/* ditto. */
1414 		/*
1415 		 * XXX do we really have FQDN in variable "hostname"?
1416 		 */
1417 		n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn);
1418 		if (n->m_next == NULL)
1419 			goto bad;
1420 		/* XXX we assume that n->m_next is not a chain */
1421 		if (n->m_next->m_next != NULL)
1422 			goto bad;
1423 		n->m_pkthdr.len += n->m_next->m_len;
1424 		break;
1425 	case NI_QTYPE_NODEADDR:
1426 	{
1427 		int lenlim, copied;
1428 
1429 		nni6->ni_code = ICMP6_NI_SUCCESS;
1430 		n->m_pkthdr.len = n->m_len =
1431 		    sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1432 		lenlim = M_TRAILINGSPACE(n);
1433 		copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1434 		/* XXX: reset mbuf length */
1435 		n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1436 		    sizeof(struct icmp6_nodeinfo) + copied;
1437 		break;
1438 	}
1439 	default:
1440 		break;		/* XXX impossible! */
1441 	}
1442 
1443 	nni6->ni_type = ICMP6_NI_REPLY;
1444 	m_freem(m);
1445 	return (n);
1446 
1447   bad:
1448 	m_freem(m);
1449 	if (n)
1450 		m_freem(n);
1451 	return (NULL);
1452 }
1453 #undef hostnamelen
1454 
1455 /*
1456  * make a mbuf with DNS-encoded string.  no compression support.
1457  *
1458  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1459  * treated as truncated name (two \0 at the end).  this is a wild guess.
1460  */
1461 static struct mbuf *
1462 ni6_nametodns(name, namelen, old)
1463 	const char *name;
1464 	int namelen;
1465 	int old;	/* return pascal string if non-zero */
1466 {
1467 	struct mbuf *m;
1468 	char *cp, *ep;
1469 	const char *p, *q;
1470 	int i, len, nterm;
1471 
1472 	if (old)
1473 		len = namelen + 1;
1474 	else
1475 		len = MCLBYTES;
1476 
1477 	/* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1478 	MGET(m, M_DONTWAIT, MT_DATA);
1479 	if (m && len > MLEN) {
1480 		MCLGET(m, M_DONTWAIT);
1481 		if ((m->m_flags & M_EXT) == 0)
1482 			goto fail;
1483 	}
1484 	if (!m)
1485 		goto fail;
1486 	m->m_next = NULL;
1487 
1488 	if (old) {
1489 		m->m_len = len;
1490 		*mtod(m, char *) = namelen;
1491 		bcopy(name, mtod(m, char *) + 1, namelen);
1492 		return m;
1493 	} else {
1494 		m->m_len = 0;
1495 		cp = mtod(m, char *);
1496 		ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1497 
1498 		/* if not certain about my name, return empty buffer */
1499 		if (namelen == 0)
1500 			return m;
1501 
1502 		/*
1503 		 * guess if it looks like shortened hostname, or FQDN.
1504 		 * shortened hostname needs two trailing "\0".
1505 		 */
1506 		i = 0;
1507 		for (p = name; p < name + namelen; p++) {
1508 			if (*p && *p == '.')
1509 				i++;
1510 		}
1511 		if (i < 2)
1512 			nterm = 2;
1513 		else
1514 			nterm = 1;
1515 
1516 		p = name;
1517 		while (cp < ep && p < name + namelen) {
1518 			i = 0;
1519 			for (q = p; q < name + namelen && *q && *q != '.'; q++)
1520 				i++;
1521 			/* result does not fit into mbuf */
1522 			if (cp + i + 1 >= ep)
1523 				goto fail;
1524 			/*
1525 			 * DNS label length restriction, RFC1035 page 8.
1526 			 * "i == 0" case is included here to avoid returning
1527 			 * 0-length label on "foo..bar".
1528 			 */
1529 			if (i <= 0 || i >= 64)
1530 				goto fail;
1531 			*cp++ = i;
1532 			bcopy(p, cp, i);
1533 			cp += i;
1534 			p = q;
1535 			if (p < name + namelen && *p == '.')
1536 				p++;
1537 		}
1538 		/* termination */
1539 		if (cp + nterm >= ep)
1540 			goto fail;
1541 		while (nterm-- > 0)
1542 			*cp++ = '\0';
1543 		m->m_len = cp - mtod(m, char *);
1544 		return m;
1545 	}
1546 
1547 	panic("should not reach here");
1548 	/* NOTREACHED */
1549 
1550  fail:
1551 	if (m)
1552 		m_freem(m);
1553 	return NULL;
1554 }
1555 
1556 /*
1557  * check if two DNS-encoded string matches.  takes care of truncated
1558  * form (with \0\0 at the end).  no compression support.
1559  * XXX upper/lowercase match (see RFC2065)
1560  */
1561 static int
1562 ni6_dnsmatch(a, alen, b, blen)
1563 	const char *a;
1564 	int alen;
1565 	const char *b;
1566 	int blen;
1567 {
1568 	const char *a0, *b0;
1569 	int l;
1570 
1571 	/* simplest case - need validation? */
1572 	if (alen == blen && bcmp(a, b, alen) == 0)
1573 		return 1;
1574 
1575 	a0 = a;
1576 	b0 = b;
1577 
1578 	/* termination is mandatory */
1579 	if (alen < 2 || blen < 2)
1580 		return 0;
1581 	if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1582 		return 0;
1583 	alen--;
1584 	blen--;
1585 
1586 	while (a - a0 < alen && b - b0 < blen) {
1587 		if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1588 			return 0;
1589 
1590 		if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1591 			return 0;
1592 		/* we don't support compression yet */
1593 		if (a[0] >= 64 || b[0] >= 64)
1594 			return 0;
1595 
1596 		/* truncated case */
1597 		if (a[0] == 0 && a - a0 == alen - 1)
1598 			return 1;
1599 		if (b[0] == 0 && b - b0 == blen - 1)
1600 			return 1;
1601 		if (a[0] == 0 || b[0] == 0)
1602 			return 0;
1603 
1604 		if (a[0] != b[0])
1605 			return 0;
1606 		l = a[0];
1607 		if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1608 			return 0;
1609 		if (bcmp(a + 1, b + 1, l) != 0)
1610 			return 0;
1611 
1612 		a += 1 + l;
1613 		b += 1 + l;
1614 	}
1615 
1616 	if (a - a0 == alen && b - b0 == blen)
1617 		return 1;
1618 	else
1619 		return 0;
1620 }
1621 
1622 /*
1623  * calculate the number of addresses to be returned in the node info reply.
1624  */
1625 static int
1626 ni6_addrs(ni6, m, ifpp, subj)
1627 	struct icmp6_nodeinfo *ni6;
1628 	struct mbuf *m;
1629 	struct ifnet **ifpp;
1630 	struct in6_addr *subj;
1631 {
1632 	struct ifnet *ifp;
1633 	struct in6_ifaddr *ifa6;
1634 	struct ifaddr *ifa;
1635 	int addrs = 0, addrsofif, iffound = 0;
1636 	int niflags = ni6->ni_flags;
1637 
1638 	if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1639 		switch (ni6->ni_code) {
1640 		case ICMP6_NI_SUBJ_IPV6:
1641 			if (subj == NULL) /* must be impossible... */
1642 				return (0);
1643 			break;
1644 		default:
1645 			/*
1646 			 * XXX: we only support IPv6 subject address for
1647 			 * this Qtype.
1648 			 */
1649 			return (0);
1650 		}
1651 	}
1652 
1653 	IFNET_RLOCK();
1654 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1655 		addrsofif = 0;
1656 		TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
1657 			if (ifa->ifa_addr->sa_family != AF_INET6)
1658 				continue;
1659 			ifa6 = (struct in6_ifaddr *)ifa;
1660 
1661 			if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1662 			    IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1663 				iffound = 1;
1664 
1665 			/*
1666 			 * IPv4-mapped addresses can only be returned by a
1667 			 * Node Information proxy, since they represent
1668 			 * addresses of IPv4-only nodes, which perforce do
1669 			 * not implement this protocol.
1670 			 * [icmp-name-lookups-07, Section 5.4]
1671 			 * So we don't support NI_NODEADDR_FLAG_COMPAT in
1672 			 * this function at this moment.
1673 			 */
1674 
1675 			/* What do we have to do about ::1? */
1676 			switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1677 			case IPV6_ADDR_SCOPE_LINKLOCAL:
1678 				if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1679 					continue;
1680 				break;
1681 			case IPV6_ADDR_SCOPE_SITELOCAL:
1682 				if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1683 					continue;
1684 				break;
1685 			case IPV6_ADDR_SCOPE_GLOBAL:
1686 				if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1687 					continue;
1688 				break;
1689 			default:
1690 				continue;
1691 			}
1692 
1693 			/*
1694 			 * check if anycast is okay.
1695 			 * XXX: just experimental.  not in the spec.
1696 			 */
1697 			if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1698 			    (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1699 				continue; /* we need only unicast addresses */
1700 			if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1701 			    (icmp6_nodeinfo & 4) == 0) {
1702 				continue;
1703 			}
1704 			addrsofif++; /* count the address */
1705 		}
1706 		if (iffound) {
1707 			*ifpp = ifp;
1708 			IFNET_RUNLOCK();
1709 			return (addrsofif);
1710 		}
1711 
1712 		addrs += addrsofif;
1713 	}
1714 	IFNET_RUNLOCK();
1715 
1716 	return (addrs);
1717 }
1718 
1719 static int
1720 ni6_store_addrs(ni6, nni6, ifp0, resid)
1721 	struct icmp6_nodeinfo *ni6, *nni6;
1722 	struct ifnet *ifp0;
1723 	int resid;
1724 {
1725 	struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet);
1726 	struct in6_ifaddr *ifa6;
1727 	struct ifaddr *ifa;
1728 	struct ifnet *ifp_dep = NULL;
1729 	int copied = 0, allow_deprecated = 0;
1730 	u_char *cp = (u_char *)(nni6 + 1);
1731 	int niflags = ni6->ni_flags;
1732 	u_int32_t ltime;
1733 
1734 	if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1735 		return (0);	/* needless to copy */
1736 
1737 	IFNET_RLOCK();
1738   again:
1739 
1740 	for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1741 		for (ifa = ifp->if_addrlist.tqh_first; ifa;
1742 		     ifa = ifa->ifa_list.tqe_next) {
1743 			if (ifa->ifa_addr->sa_family != AF_INET6)
1744 				continue;
1745 			ifa6 = (struct in6_ifaddr *)ifa;
1746 
1747 			if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1748 			    allow_deprecated == 0) {
1749 				/*
1750 				 * prefererred address should be put before
1751 				 * deprecated addresses.
1752 				 */
1753 
1754 				/* record the interface for later search */
1755 				if (ifp_dep == NULL)
1756 					ifp_dep = ifp;
1757 
1758 				continue;
1759 			} else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1760 			    allow_deprecated != 0)
1761 				continue; /* we now collect deprecated addrs */
1762 
1763 			/* What do we have to do about ::1? */
1764 			switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1765 			case IPV6_ADDR_SCOPE_LINKLOCAL:
1766 				if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1767 					continue;
1768 				break;
1769 			case IPV6_ADDR_SCOPE_SITELOCAL:
1770 				if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1771 					continue;
1772 				break;
1773 			case IPV6_ADDR_SCOPE_GLOBAL:
1774 				if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1775 					continue;
1776 				break;
1777 			default:
1778 				continue;
1779 			}
1780 
1781 			/*
1782 			 * check if anycast is okay.
1783 			 * XXX: just experimental.  not in the spec.
1784 			 */
1785 			if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1786 			    (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1787 				continue;
1788 			if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1789 			    (icmp6_nodeinfo & 4) == 0) {
1790 				continue;
1791 			}
1792 
1793 			/* now we can copy the address */
1794 			if (resid < sizeof(struct in6_addr) +
1795 			    sizeof(u_int32_t)) {
1796 				/*
1797 				 * We give up much more copy.
1798 				 * Set the truncate flag and return.
1799 				 */
1800 				nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1801 				IFNET_RUNLOCK();
1802 				return (copied);
1803 			}
1804 
1805 			/*
1806 			 * Set the TTL of the address.
1807 			 * The TTL value should be one of the following
1808 			 * according to the specification:
1809 			 *
1810 			 * 1. The remaining lifetime of a DHCP lease on the
1811 			 *    address, or
1812 			 * 2. The remaining Valid Lifetime of a prefix from
1813 			 *    which the address was derived through Stateless
1814 			 *    Autoconfiguration.
1815 			 *
1816 			 * Note that we currently do not support stateful
1817 			 * address configuration by DHCPv6, so the former
1818 			 * case can't happen.
1819 			 */
1820 			if (ifa6->ia6_lifetime.ia6t_expire == 0)
1821 				ltime = ND6_INFINITE_LIFETIME;
1822 			else {
1823 				if (ifa6->ia6_lifetime.ia6t_expire >
1824 				    time_second)
1825 					ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second);
1826 				else
1827 					ltime = 0;
1828 			}
1829 
1830 			bcopy(&ltime, cp, sizeof(u_int32_t));
1831 			cp += sizeof(u_int32_t);
1832 
1833 			/* copy the address itself */
1834 			bcopy(&ifa6->ia_addr.sin6_addr, cp,
1835 			    sizeof(struct in6_addr));
1836 			in6_clearscope((struct in6_addr *)cp); /* XXX */
1837 			cp += sizeof(struct in6_addr);
1838 
1839 			resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1840 			copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1841 		}
1842 		if (ifp0)	/* we need search only on the specified IF */
1843 			break;
1844 	}
1845 
1846 	if (allow_deprecated == 0 && ifp_dep != NULL) {
1847 		ifp = ifp_dep;
1848 		allow_deprecated = 1;
1849 
1850 		goto again;
1851 	}
1852 
1853 	IFNET_RUNLOCK();
1854 
1855 	return (copied);
1856 }
1857 
1858 /*
1859  * XXX almost dup'ed code with rip6_input.
1860  */
1861 static int
1862 icmp6_rip6_input(mp, off)
1863 	struct	mbuf **mp;
1864 	int	off;
1865 {
1866 	struct mbuf *m = *mp;
1867 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1868 	struct in6pcb *in6p;
1869 	struct in6pcb *last = NULL;
1870 	struct sockaddr_in6 fromsa;
1871 	struct icmp6_hdr *icmp6;
1872 	struct mbuf *opts = NULL;
1873 
1874 #ifndef PULLDOWN_TEST
1875 	/* this is assumed to be safe. */
1876 	icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1877 #else
1878 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1879 	if (icmp6 == NULL) {
1880 		/* m is already reclaimed */
1881 		return (IPPROTO_DONE);
1882 	}
1883 #endif
1884 
1885 	/*
1886 	 * XXX: the address may have embedded scope zone ID, which should be
1887 	 * hidden from applications.
1888 	 */
1889 	bzero(&fromsa, sizeof(fromsa));
1890 	fromsa.sin6_family = AF_INET6;
1891 	fromsa.sin6_len = sizeof(struct sockaddr_in6);
1892 	fromsa.sin6_addr = ip6->ip6_src;
1893 	if (sa6_recoverscope(&fromsa)) {
1894 		m_freem(m);
1895 		return (IPPROTO_DONE);
1896 	}
1897 
1898 	INP_INFO_RLOCK(&ripcbinfo);
1899 	LIST_FOREACH(in6p, &ripcb, inp_list) {
1900 		INP_LOCK(in6p);
1901 		if ((in6p->inp_vflag & INP_IPV6) == 0) {
1902 	docontinue:
1903 			INP_UNLOCK(in6p);
1904 			continue;
1905 		}
1906 		if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6)
1907 			goto docontinue;
1908 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1909 		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1910 			goto docontinue;
1911 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1912 		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1913 			goto docontinue;
1914 		if (in6p->in6p_icmp6filt
1915 		    && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1916 				 in6p->in6p_icmp6filt))
1917 			goto docontinue;
1918 		if (last) {
1919 			struct	mbuf *n = NULL;
1920 
1921 			/*
1922 			 * Recent network drivers tend to allocate a single
1923 			 * mbuf cluster, rather than to make a couple of
1924 			 * mbufs without clusters.  Also, since the IPv6 code
1925 			 * path tries to avoid m_pullup(), it is highly
1926 			 * probable that we still have an mbuf cluster here
1927 			 * even though the necessary length can be stored in an
1928 			 * mbuf's internal buffer.
1929 			 * Meanwhile, the default size of the receive socket
1930 			 * buffer for raw sockets is not so large.  This means
1931 			 * the possibility of packet loss is relatively higher
1932 			 * than before.  To avoid this scenario, we copy the
1933 			 * received data to a separate mbuf that does not use
1934 			 * a cluster, if possible.
1935 			 * XXX: it is better to copy the data after stripping
1936 			 * intermediate headers.
1937 			 */
1938 			if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1939 			    m->m_len <= MHLEN) {
1940 				MGET(n, M_DONTWAIT, m->m_type);
1941 				if (n != NULL) {
1942 					if (m_dup_pkthdr(n, m, M_NOWAIT)) {
1943 						bcopy(m->m_data, n->m_data,
1944 						      m->m_len);
1945 						n->m_len = m->m_len;
1946 					} else {
1947 						m_free(n);
1948 						n = NULL;
1949 					}
1950 				}
1951 			}
1952 			if (n != NULL ||
1953 			    (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
1954 				if (last->in6p_flags & IN6P_CONTROLOPTS)
1955 					ip6_savecontrol(last, n, &opts);
1956 				/* strip intermediate headers */
1957 				m_adj(n, off);
1958 				SOCKBUF_LOCK(&last->in6p_socket->so_rcv);
1959 				if (sbappendaddr_locked(
1960 				    &last->in6p_socket->so_rcv,
1961 				    (struct sockaddr *)&fromsa, n, opts)
1962 				    == 0) {
1963 					/* should notify about lost packet */
1964 					m_freem(n);
1965 					if (opts) {
1966 						m_freem(opts);
1967 					}
1968 					SOCKBUF_UNLOCK(
1969 					    &last->in6p_socket->so_rcv);
1970 				} else
1971 					sorwakeup_locked(last->in6p_socket);
1972 				opts = NULL;
1973 			}
1974 			INP_UNLOCK(last);
1975 		}
1976 		last = in6p;
1977 	}
1978 	if (last) {
1979 		if (last->in6p_flags & IN6P_CONTROLOPTS)
1980 			ip6_savecontrol(last, m, &opts);
1981 		/* strip intermediate headers */
1982 		m_adj(m, off);
1983 
1984 		/* avoid using mbuf clusters if possible (see above) */
1985 		if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1986 		    m->m_len <= MHLEN) {
1987 			struct mbuf *n;
1988 
1989 			MGET(n, M_DONTWAIT, m->m_type);
1990 			if (n != NULL) {
1991 				if (m_dup_pkthdr(n, m, M_NOWAIT)) {
1992 					bcopy(m->m_data, n->m_data, m->m_len);
1993 					n->m_len = m->m_len;
1994 
1995 					m_freem(m);
1996 					m = n;
1997 				} else {
1998 					m_freem(n);
1999 					n = NULL;
2000 				}
2001 			}
2002 		}
2003 		SOCKBUF_LOCK(&last->in6p_socket->so_rcv);
2004 		if (sbappendaddr_locked(&last->in6p_socket->so_rcv,
2005 		    (struct sockaddr *)&fromsa, m, opts) == 0) {
2006 			m_freem(m);
2007 			if (opts)
2008 				m_freem(opts);
2009 			SOCKBUF_UNLOCK(&last->in6p_socket->so_rcv);
2010 		} else
2011 			sorwakeup_locked(last->in6p_socket);
2012 		INP_UNLOCK(last);
2013 	} else {
2014 		m_freem(m);
2015 		ip6stat.ip6s_delivered--;
2016 	}
2017 	INP_INFO_RUNLOCK(&ripcbinfo);
2018 	return IPPROTO_DONE;
2019 }
2020 
2021 /*
2022  * Reflect the ip6 packet back to the source.
2023  * OFF points to the icmp6 header, counted from the top of the mbuf.
2024  */
2025 void
2026 icmp6_reflect(m, off)
2027 	struct	mbuf *m;
2028 	size_t off;
2029 {
2030 	struct ip6_hdr *ip6;
2031 	struct icmp6_hdr *icmp6;
2032 	struct in6_ifaddr *ia;
2033 	int plen;
2034 	int type, code;
2035 	struct ifnet *outif = NULL;
2036 	struct in6_addr origdst, *src = NULL;
2037 
2038 	/* too short to reflect */
2039 	if (off < sizeof(struct ip6_hdr)) {
2040 		nd6log((LOG_DEBUG,
2041 		    "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2042 		    (u_long)off, (u_long)sizeof(struct ip6_hdr),
2043 		    __FILE__, __LINE__));
2044 		goto bad;
2045 	}
2046 
2047 	/*
2048 	 * If there are extra headers between IPv6 and ICMPv6, strip
2049 	 * off that header first.
2050 	 */
2051 #ifdef DIAGNOSTIC
2052 	if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2053 		panic("assumption failed in icmp6_reflect");
2054 #endif
2055 	if (off > sizeof(struct ip6_hdr)) {
2056 		size_t l;
2057 		struct ip6_hdr nip6;
2058 
2059 		l = off - sizeof(struct ip6_hdr);
2060 		m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2061 		m_adj(m, l);
2062 		l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2063 		if (m->m_len < l) {
2064 			if ((m = m_pullup(m, l)) == NULL)
2065 				return;
2066 		}
2067 		bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2068 	} else /* off == sizeof(struct ip6_hdr) */ {
2069 		size_t l;
2070 		l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2071 		if (m->m_len < l) {
2072 			if ((m = m_pullup(m, l)) == NULL)
2073 				return;
2074 		}
2075 	}
2076 	plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2077 	ip6 = mtod(m, struct ip6_hdr *);
2078 	ip6->ip6_nxt = IPPROTO_ICMPV6;
2079 	icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2080 	type = icmp6->icmp6_type; /* keep type for statistics */
2081 	code = icmp6->icmp6_code; /* ditto. */
2082 
2083 	origdst = ip6->ip6_dst;
2084 	/*
2085 	 * ip6_input() drops a packet if its src is multicast.
2086 	 * So, the src is never multicast.
2087 	 */
2088 	ip6->ip6_dst = ip6->ip6_src;
2089 
2090 	/*
2091 	 * If the incoming packet was addressed directly to us (i.e. unicast),
2092 	 * use dst as the src for the reply.
2093 	 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2094 	 * (for example) when we encounter an error while forwarding procedure
2095 	 * destined to a duplicated address of ours.
2096 	 * Note that ip6_getdstifaddr() may fail if we are in an error handling
2097 	 * procedure of an outgoing packet of our own, in which case we need
2098 	 * to search in the ifaddr list.
2099 	 */
2100 	if (!IN6_IS_ADDR_MULTICAST(&origdst)) {
2101 		if ((ia = ip6_getdstifaddr(m))) {
2102 			if (!(ia->ia6_flags &
2103 			    (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)))
2104 				src = &ia->ia_addr.sin6_addr;
2105 		} else {
2106 			struct sockaddr_in6 d;
2107 
2108 			bzero(&d, sizeof(d));
2109 			d.sin6_family = AF_INET6;
2110 			d.sin6_len = sizeof(d);
2111 			d.sin6_addr = origdst;
2112 			ia = (struct in6_ifaddr *)
2113 			    ifa_ifwithaddr((struct sockaddr *)&d);
2114 			if (ia &&
2115 			    !(ia->ia6_flags &
2116 			    (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2117 				src = &ia->ia_addr.sin6_addr;
2118 			}
2119 		}
2120 	}
2121 
2122 	if (src == NULL) {
2123 		int e;
2124 		struct sockaddr_in6 sin6;
2125 		struct route_in6 ro;
2126 
2127 		/*
2128 		 * This case matches to multicasts, our anycast, or unicasts
2129 		 * that we do not own.  Select a source address based on the
2130 		 * source address of the erroneous packet.
2131 		 */
2132 		bzero(&sin6, sizeof(sin6));
2133 		sin6.sin6_family = AF_INET6;
2134 		sin6.sin6_len = sizeof(sin6);
2135 		sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */
2136 
2137 		bzero(&ro, sizeof(ro));
2138 		src = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &e);
2139 		if (ro.ro_rt)
2140 			RTFREE(ro.ro_rt); /* XXX: we could use this */
2141 		if (src == NULL) {
2142 			char ip6buf[INET6_ADDRSTRLEN];
2143 			nd6log((LOG_DEBUG,
2144 			    "icmp6_reflect: source can't be determined: "
2145 			    "dst=%s, error=%d\n",
2146 			    ip6_sprintf(ip6buf, &sin6.sin6_addr), e));
2147 			goto bad;
2148 		}
2149 	}
2150 
2151 	ip6->ip6_src = *src;
2152 	ip6->ip6_flow = 0;
2153 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2154 	ip6->ip6_vfc |= IPV6_VERSION;
2155 	ip6->ip6_nxt = IPPROTO_ICMPV6;
2156 	if (outif)
2157 		ip6->ip6_hlim = ND_IFINFO(outif)->chlim;
2158 	else if (m->m_pkthdr.rcvif) {
2159 		/* XXX: This may not be the outgoing interface */
2160 		ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2161 	} else
2162 		ip6->ip6_hlim = ip6_defhlim;
2163 
2164 	icmp6->icmp6_cksum = 0;
2165 	icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2166 	    sizeof(struct ip6_hdr), plen);
2167 
2168 	/*
2169 	 * XXX option handling
2170 	 */
2171 
2172 	m->m_flags &= ~(M_BCAST|M_MCAST);
2173 
2174 	ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2175 	if (outif)
2176 		icmp6_ifoutstat_inc(outif, type, code);
2177 
2178 	return;
2179 
2180  bad:
2181 	m_freem(m);
2182 	return;
2183 }
2184 
2185 void
2186 icmp6_fasttimo()
2187 {
2188 
2189 	return;
2190 }
2191 
2192 static const char *
2193 icmp6_redirect_diag(src6, dst6, tgt6)
2194 	struct in6_addr *src6;
2195 	struct in6_addr *dst6;
2196 	struct in6_addr *tgt6;
2197 {
2198 	static char buf[1024];
2199 	char ip6bufs[INET6_ADDRSTRLEN];
2200 	char ip6bufd[INET6_ADDRSTRLEN];
2201 	char ip6buft[INET6_ADDRSTRLEN];
2202 	snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2203 	    ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2204 	    ip6_sprintf(ip6buft, tgt6));
2205 	return buf;
2206 }
2207 
2208 void
2209 icmp6_redirect_input(m, off)
2210 	struct mbuf *m;
2211 	int off;
2212 {
2213 	struct ifnet *ifp = m->m_pkthdr.rcvif;
2214 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2215 	struct nd_redirect *nd_rd;
2216 	int icmp6len = ntohs(ip6->ip6_plen);
2217 	char *lladdr = NULL;
2218 	int lladdrlen = 0;
2219 	u_char *redirhdr = NULL;
2220 	int redirhdrlen = 0;
2221 	struct rtentry *rt = NULL;
2222 	int is_router;
2223 	int is_onlink;
2224 	struct in6_addr src6 = ip6->ip6_src;
2225 	struct in6_addr redtgt6;
2226 	struct in6_addr reddst6;
2227 	union nd_opts ndopts;
2228 	char ip6buf[INET6_ADDRSTRLEN];
2229 
2230 	if (!m || !ifp)
2231 		return;
2232 
2233 	/* XXX if we are router, we don't update route by icmp6 redirect */
2234 	if (ip6_forwarding)
2235 		goto freeit;
2236 	if (!icmp6_rediraccept)
2237 		goto freeit;
2238 
2239 #ifndef PULLDOWN_TEST
2240 	IP6_EXTHDR_CHECK(m, off, icmp6len,);
2241 	nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2242 #else
2243 	IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2244 	if (nd_rd == NULL) {
2245 		icmp6stat.icp6s_tooshort++;
2246 		return;
2247 	}
2248 #endif
2249 	redtgt6 = nd_rd->nd_rd_target;
2250 	reddst6 = nd_rd->nd_rd_dst;
2251 
2252 	if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2253 	    in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2254 		goto freeit;
2255 	}
2256 
2257 	/* validation */
2258 	if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2259 		nd6log((LOG_ERR,
2260 		    "ICMP6 redirect sent from %s rejected; "
2261 		    "must be from linklocal\n",
2262 		    ip6_sprintf(ip6buf, &src6)));
2263 		goto bad;
2264 	}
2265 	if (ip6->ip6_hlim != 255) {
2266 		nd6log((LOG_ERR,
2267 		    "ICMP6 redirect sent from %s rejected; "
2268 		    "hlim=%d (must be 255)\n",
2269 		    ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2270 		goto bad;
2271 	}
2272     {
2273 	/* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2274 	struct sockaddr_in6 sin6;
2275 	struct in6_addr *gw6;
2276 
2277 	bzero(&sin6, sizeof(sin6));
2278 	sin6.sin6_family = AF_INET6;
2279 	sin6.sin6_len = sizeof(struct sockaddr_in6);
2280 	bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
2281 	rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
2282 	if (rt) {
2283 		if (rt->rt_gateway == NULL ||
2284 		    rt->rt_gateway->sa_family != AF_INET6) {
2285 			nd6log((LOG_ERR,
2286 			    "ICMP6 redirect rejected; no route "
2287 			    "with inet6 gateway found for redirect dst: %s\n",
2288 			    icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2289 			RTFREE_LOCKED(rt);
2290 			goto bad;
2291 		}
2292 
2293 		gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2294 		if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2295 			nd6log((LOG_ERR,
2296 			    "ICMP6 redirect rejected; "
2297 			    "not equal to gw-for-src=%s (must be same): "
2298 			    "%s\n",
2299 			    ip6_sprintf(ip6buf, gw6),
2300 			    icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2301 			RTFREE_LOCKED(rt);
2302 			goto bad;
2303 		}
2304 	} else {
2305 		nd6log((LOG_ERR,
2306 		    "ICMP6 redirect rejected; "
2307 		    "no route found for redirect dst: %s\n",
2308 		    icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2309 		goto bad;
2310 	}
2311 	RTFREE_LOCKED(rt);
2312 	rt = NULL;
2313     }
2314 	if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2315 		nd6log((LOG_ERR,
2316 		    "ICMP6 redirect rejected; "
2317 		    "redirect dst must be unicast: %s\n",
2318 		    icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2319 		goto bad;
2320 	}
2321 
2322 	is_router = is_onlink = 0;
2323 	if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2324 		is_router = 1;	/* router case */
2325 	if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2326 		is_onlink = 1;	/* on-link destination case */
2327 	if (!is_router && !is_onlink) {
2328 		nd6log((LOG_ERR,
2329 		    "ICMP6 redirect rejected; "
2330 		    "neither router case nor onlink case: %s\n",
2331 		    icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2332 		goto bad;
2333 	}
2334 	/* validation passed */
2335 
2336 	icmp6len -= sizeof(*nd_rd);
2337 	nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2338 	if (nd6_options(&ndopts) < 0) {
2339 		nd6log((LOG_INFO, "icmp6_redirect_input: "
2340 		    "invalid ND option, rejected: %s\n",
2341 		    icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2342 		/* nd6_options have incremented stats */
2343 		goto freeit;
2344 	}
2345 
2346 	if (ndopts.nd_opts_tgt_lladdr) {
2347 		lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2348 		lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2349 	}
2350 
2351 	if (ndopts.nd_opts_rh) {
2352 		redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
2353 		redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
2354 	}
2355 
2356 	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2357 		nd6log((LOG_INFO,
2358 		    "icmp6_redirect_input: lladdrlen mismatch for %s "
2359 		    "(if %d, icmp6 packet %d): %s\n",
2360 		    ip6_sprintf(ip6buf, &redtgt6),
2361 		    ifp->if_addrlen, lladdrlen - 2,
2362 		    icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2363 		goto bad;
2364 	}
2365 
2366 	/* RFC 2461 8.3 */
2367 	nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2368 	    is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2369 
2370 	if (!is_onlink) {	/* better router case.  perform rtredirect. */
2371 		/* perform rtredirect */
2372 		struct sockaddr_in6 sdst;
2373 		struct sockaddr_in6 sgw;
2374 		struct sockaddr_in6 ssrc;
2375 
2376 		bzero(&sdst, sizeof(sdst));
2377 		bzero(&sgw, sizeof(sgw));
2378 		bzero(&ssrc, sizeof(ssrc));
2379 		sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2380 		sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2381 			sizeof(struct sockaddr_in6);
2382 		bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2383 		bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2384 		bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2385 		rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2386 		    (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
2387 		    (struct sockaddr *)&ssrc);
2388 	}
2389 	/* finally update cached route in each socket via pfctlinput */
2390     {
2391 	struct sockaddr_in6 sdst;
2392 
2393 	bzero(&sdst, sizeof(sdst));
2394 	sdst.sin6_family = AF_INET6;
2395 	sdst.sin6_len = sizeof(struct sockaddr_in6);
2396 	bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2397 	pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2398 #if defined(IPSEC) || defined(FAST_IPSEC)
2399 	key_sa_routechange((struct sockaddr *)&sdst);
2400 #endif
2401     }
2402 
2403  freeit:
2404 	m_freem(m);
2405 	return;
2406 
2407  bad:
2408 	icmp6stat.icp6s_badredirect++;
2409 	m_freem(m);
2410 }
2411 
2412 void
2413 icmp6_redirect_output(m0, rt)
2414 	struct mbuf *m0;
2415 	struct rtentry *rt;
2416 {
2417 	struct ifnet *ifp;	/* my outgoing interface */
2418 	struct in6_addr *ifp_ll6;
2419 	struct in6_addr *router_ll6;
2420 	struct ip6_hdr *sip6;	/* m0 as struct ip6_hdr */
2421 	struct mbuf *m = NULL;	/* newly allocated one */
2422 	struct ip6_hdr *ip6;	/* m as struct ip6_hdr */
2423 	struct nd_redirect *nd_rd;
2424 	size_t maxlen;
2425 	u_char *p;
2426 	struct ifnet *outif = NULL;
2427 	struct sockaddr_in6 src_sa;
2428 
2429 	icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
2430 
2431 	/* if we are not router, we don't send icmp6 redirect */
2432 	if (!ip6_forwarding)
2433 		goto fail;
2434 
2435 	/* sanity check */
2436 	if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2437 		goto fail;
2438 
2439 	/*
2440 	 * Address check:
2441 	 *  the source address must identify a neighbor, and
2442 	 *  the destination address must not be a multicast address
2443 	 *  [RFC 2461, sec 8.2]
2444 	 */
2445 	sip6 = mtod(m0, struct ip6_hdr *);
2446 	bzero(&src_sa, sizeof(src_sa));
2447 	src_sa.sin6_family = AF_INET6;
2448 	src_sa.sin6_len = sizeof(src_sa);
2449 	src_sa.sin6_addr = sip6->ip6_src;
2450 	if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2451 		goto fail;
2452 	if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2453 		goto fail;	/* what should we do here? */
2454 
2455 	/* rate limit */
2456 	if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2457 		goto fail;
2458 
2459 	/*
2460 	 * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2461 	 * we almost always ask for an mbuf cluster for simplicity.
2462 	 * (MHLEN < IPV6_MMTU is almost always true)
2463 	 */
2464 #if IPV6_MMTU >= MCLBYTES
2465 # error assumption failed about IPV6_MMTU and MCLBYTES
2466 #endif
2467 	MGETHDR(m, M_DONTWAIT, MT_HEADER);
2468 	if (m && IPV6_MMTU >= MHLEN)
2469 		MCLGET(m, M_DONTWAIT);
2470 	if (!m)
2471 		goto fail;
2472 	m->m_pkthdr.rcvif = NULL;
2473 	m->m_len = 0;
2474 	maxlen = M_TRAILINGSPACE(m);
2475 	maxlen = min(IPV6_MMTU, maxlen);
2476 	/* just for safety */
2477 	if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2478 	    ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2479 		goto fail;
2480 	}
2481 
2482 	{
2483 		/* get ip6 linklocal address for ifp(my outgoing interface). */
2484 		struct in6_ifaddr *ia;
2485 		if ((ia = in6ifa_ifpforlinklocal(ifp,
2486 						 IN6_IFF_NOTREADY|
2487 						 IN6_IFF_ANYCAST)) == NULL)
2488 			goto fail;
2489 		ifp_ll6 = &ia->ia_addr.sin6_addr;
2490 	}
2491 
2492 	/* get ip6 linklocal address for the router. */
2493 	if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2494 		struct sockaddr_in6 *sin6;
2495 		sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2496 		router_ll6 = &sin6->sin6_addr;
2497 		if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2498 			router_ll6 = (struct in6_addr *)NULL;
2499 	} else
2500 		router_ll6 = (struct in6_addr *)NULL;
2501 
2502 	/* ip6 */
2503 	ip6 = mtod(m, struct ip6_hdr *);
2504 	ip6->ip6_flow = 0;
2505 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2506 	ip6->ip6_vfc |= IPV6_VERSION;
2507 	/* ip6->ip6_plen will be set later */
2508 	ip6->ip6_nxt = IPPROTO_ICMPV6;
2509 	ip6->ip6_hlim = 255;
2510 	/* ip6->ip6_src must be linklocal addr for my outgoing if. */
2511 	bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2512 	bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2513 
2514 	/* ND Redirect */
2515 	nd_rd = (struct nd_redirect *)(ip6 + 1);
2516 	nd_rd->nd_rd_type = ND_REDIRECT;
2517 	nd_rd->nd_rd_code = 0;
2518 	nd_rd->nd_rd_reserved = 0;
2519 	if (rt->rt_flags & RTF_GATEWAY) {
2520 		/*
2521 		 * nd_rd->nd_rd_target must be a link-local address in
2522 		 * better router cases.
2523 		 */
2524 		if (!router_ll6)
2525 			goto fail;
2526 		bcopy(router_ll6, &nd_rd->nd_rd_target,
2527 		    sizeof(nd_rd->nd_rd_target));
2528 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2529 		    sizeof(nd_rd->nd_rd_dst));
2530 	} else {
2531 		/* make sure redtgt == reddst */
2532 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2533 		    sizeof(nd_rd->nd_rd_target));
2534 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2535 		    sizeof(nd_rd->nd_rd_dst));
2536 	}
2537 
2538 	p = (u_char *)(nd_rd + 1);
2539 
2540 	if (!router_ll6)
2541 		goto nolladdropt;
2542 
2543 	{
2544 		/* target lladdr option */
2545 		struct rtentry *rt_router = NULL;
2546 		int len;
2547 		struct sockaddr_dl *sdl;
2548 		struct nd_opt_hdr *nd_opt;
2549 		char *lladdr;
2550 
2551 		rt_router = nd6_lookup(router_ll6, 0, ifp);
2552 		if (!rt_router)
2553 			goto nolladdropt;
2554 		len = sizeof(*nd_opt) + ifp->if_addrlen;
2555 		len = (len + 7) & ~7;	/* round by 8 */
2556 		/* safety check */
2557 		if (len + (p - (u_char *)ip6) > maxlen)
2558 			goto nolladdropt;
2559 		if (!(rt_router->rt_flags & RTF_GATEWAY) &&
2560 		    (rt_router->rt_flags & RTF_LLINFO) &&
2561 		    (rt_router->rt_gateway->sa_family == AF_LINK) &&
2562 		    (sdl = (struct sockaddr_dl *)rt_router->rt_gateway) &&
2563 		    sdl->sdl_alen) {
2564 			nd_opt = (struct nd_opt_hdr *)p;
2565 			nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2566 			nd_opt->nd_opt_len = len >> 3;
2567 			lladdr = (char *)(nd_opt + 1);
2568 			bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen);
2569 			p += len;
2570 		}
2571 	}
2572 nolladdropt:;
2573 
2574 	m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2575 
2576 	/* just to be safe */
2577 #ifdef M_DECRYPTED	/*not openbsd*/
2578 	if (m0->m_flags & M_DECRYPTED)
2579 		goto noredhdropt;
2580 #endif
2581 	if (p - (u_char *)ip6 > maxlen)
2582 		goto noredhdropt;
2583 
2584 	{
2585 		/* redirected header option */
2586 		int len;
2587 		struct nd_opt_rd_hdr *nd_opt_rh;
2588 
2589 		/*
2590 		 * compute the maximum size for icmp6 redirect header option.
2591 		 * XXX room for auth header?
2592 		 */
2593 		len = maxlen - (p - (u_char *)ip6);
2594 		len &= ~7;
2595 
2596 		/* This is just for simplicity. */
2597 		if (m0->m_pkthdr.len != m0->m_len) {
2598 			if (m0->m_next) {
2599 				m_freem(m0->m_next);
2600 				m0->m_next = NULL;
2601 			}
2602 			m0->m_pkthdr.len = m0->m_len;
2603 		}
2604 
2605 		/*
2606 		 * Redirected header option spec (RFC2461 4.6.3) talks nothing
2607 		 * about padding/truncate rule for the original IP packet.
2608 		 * From the discussion on IPv6imp in Feb 1999,
2609 		 * the consensus was:
2610 		 * - "attach as much as possible" is the goal
2611 		 * - pad if not aligned (original size can be guessed by
2612 		 *   original ip6 header)
2613 		 * Following code adds the padding if it is simple enough,
2614 		 * and truncates if not.
2615 		 */
2616 		if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2617 			panic("assumption failed in %s:%d", __FILE__,
2618 			    __LINE__);
2619 
2620 		if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2621 			/* not enough room, truncate */
2622 			m0->m_pkthdr.len = m0->m_len = len -
2623 			    sizeof(*nd_opt_rh);
2624 		} else {
2625 			/* enough room, pad or truncate */
2626 			size_t extra;
2627 
2628 			extra = m0->m_pkthdr.len % 8;
2629 			if (extra) {
2630 				/* pad if easy enough, truncate if not */
2631 				if (8 - extra <= M_TRAILINGSPACE(m0)) {
2632 					/* pad */
2633 					m0->m_len += (8 - extra);
2634 					m0->m_pkthdr.len += (8 - extra);
2635 				} else {
2636 					/* truncate */
2637 					m0->m_pkthdr.len -= extra;
2638 					m0->m_len -= extra;
2639 				}
2640 			}
2641 			len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2642 			m0->m_pkthdr.len = m0->m_len = len -
2643 			    sizeof(*nd_opt_rh);
2644 		}
2645 
2646 		nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2647 		bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2648 		nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2649 		nd_opt_rh->nd_opt_rh_len = len >> 3;
2650 		p += sizeof(*nd_opt_rh);
2651 		m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2652 
2653 		/* connect m0 to m */
2654 		m_tag_delete_chain(m0, NULL);
2655 		m0->m_flags &= ~M_PKTHDR;
2656 		m->m_next = m0;
2657 		m->m_pkthdr.len = m->m_len + m0->m_len;
2658 		m0 = NULL;
2659 	}
2660 noredhdropt:;
2661 	if (m0) {
2662 		m_freem(m0);
2663 		m0 = NULL;
2664 	}
2665 
2666 	/* XXX: clear embedded link IDs in the inner header */
2667 	in6_clearscope(&sip6->ip6_src);
2668 	in6_clearscope(&sip6->ip6_dst);
2669 	in6_clearscope(&nd_rd->nd_rd_target);
2670 	in6_clearscope(&nd_rd->nd_rd_dst);
2671 
2672 	ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2673 
2674 	nd_rd->nd_rd_cksum = 0;
2675 	nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2676 	    sizeof(*ip6), ntohs(ip6->ip6_plen));
2677 
2678 	/* send the packet to outside... */
2679 	ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2680 	if (outif) {
2681 		icmp6_ifstat_inc(outif, ifs6_out_msg);
2682 		icmp6_ifstat_inc(outif, ifs6_out_redirect);
2683 	}
2684 	icmp6stat.icp6s_outhist[ND_REDIRECT]++;
2685 
2686 	return;
2687 
2688 fail:
2689 	if (m)
2690 		m_freem(m);
2691 	if (m0)
2692 		m_freem(m0);
2693 }
2694 
2695 /*
2696  * ICMPv6 socket option processing.
2697  */
2698 int
2699 icmp6_ctloutput(so, sopt)
2700 	struct socket *so;
2701 	struct sockopt *sopt;
2702 {
2703 	int error = 0;
2704 	int optlen;
2705 	struct inpcb *inp = sotoinpcb(so);
2706 	int level, op, optname;
2707 
2708 	if (sopt) {
2709 		level = sopt->sopt_level;
2710 		op = sopt->sopt_dir;
2711 		optname = sopt->sopt_name;
2712 		optlen = sopt->sopt_valsize;
2713 	} else
2714 		level = op = optname = optlen = 0;
2715 
2716 	if (level != IPPROTO_ICMPV6) {
2717 		return EINVAL;
2718 	}
2719 
2720 	switch (op) {
2721 	case PRCO_SETOPT:
2722 		switch (optname) {
2723 		case ICMP6_FILTER:
2724 		    {
2725 			struct icmp6_filter *p;
2726 
2727 			if (optlen != sizeof(*p)) {
2728 				error = EMSGSIZE;
2729 				break;
2730 			}
2731 			if (inp->in6p_icmp6filt == NULL) {
2732 				error = EINVAL;
2733 				break;
2734 			}
2735 			error = sooptcopyin(sopt, inp->in6p_icmp6filt, optlen,
2736 				optlen);
2737 			break;
2738 		    }
2739 
2740 		default:
2741 			error = ENOPROTOOPT;
2742 			break;
2743 		}
2744 		break;
2745 
2746 	case PRCO_GETOPT:
2747 		switch (optname) {
2748 		case ICMP6_FILTER:
2749 		    {
2750 			if (inp->in6p_icmp6filt == NULL) {
2751 				error = EINVAL;
2752 				break;
2753 			}
2754 			error = sooptcopyout(sopt, inp->in6p_icmp6filt,
2755 				sizeof(struct icmp6_filter));
2756 			break;
2757 		    }
2758 
2759 		default:
2760 			error = ENOPROTOOPT;
2761 			break;
2762 		}
2763 		break;
2764 	}
2765 
2766 	return (error);
2767 }
2768 
2769 /*
2770  * Perform rate limit check.
2771  * Returns 0 if it is okay to send the icmp6 packet.
2772  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2773  * limitation.
2774  *
2775  * XXX per-destination/type check necessary?
2776  */
2777 static int
2778 icmp6_ratelimit(dst, type, code)
2779 	const struct in6_addr *dst;	/* not used at this moment */
2780 	const int type;			/* not used at this moment */
2781 	const int code;			/* not used at this moment */
2782 {
2783 	int ret;
2784 
2785 	ret = 0;	/* okay to send */
2786 
2787 	/* PPS limit */
2788 	if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count,
2789 	    icmp6errppslim)) {
2790 		/* The packet is subject to rate limit */
2791 		ret++;
2792 	}
2793 
2794 	return ret;
2795 }
2796