xref: /freebsd/sys/netinet6/icmp6.c (revision 0f2bd1e89db1a2f09268edea21e0ead329e092df)
1 /*-
2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the project nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	$KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $
30  */
31 
32 /*-
33  * Copyright (c) 1982, 1986, 1988, 1993
34  *	The Regents of the University of California.  All rights reserved.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  * 4. Neither the name of the University nor the names of its contributors
45  *    may be used to endorse or promote products derived from this software
46  *    without specific prior written permission.
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58  * SUCH DAMAGE.
59  *
60  *	@(#)ip_icmp.c	8.2 (Berkeley) 1/4/94
61  */
62 
63 #include <sys/cdefs.h>
64 __FBSDID("$FreeBSD$");
65 
66 #include "opt_inet.h"
67 #include "opt_inet6.h"
68 #include "opt_ipsec.h"
69 
70 #include <sys/param.h>
71 #include <sys/domain.h>
72 #include <sys/jail.h>
73 #include <sys/kernel.h>
74 #include <sys/lock.h>
75 #include <sys/malloc.h>
76 #include <sys/mbuf.h>
77 #include <sys/proc.h>
78 #include <sys/protosw.h>
79 #include <sys/signalvar.h>
80 #include <sys/socket.h>
81 #include <sys/socketvar.h>
82 #include <sys/sx.h>
83 #include <sys/syslog.h>
84 #include <sys/systm.h>
85 #include <sys/time.h>
86 
87 #include <net/if.h>
88 #include <net/if_dl.h>
89 #include <net/if_llatbl.h>
90 #include <net/if_types.h>
91 #include <net/route.h>
92 #include <net/vnet.h>
93 
94 #include <netinet/in.h>
95 #include <netinet/in_pcb.h>
96 #include <netinet/in_var.h>
97 #include <netinet/ip6.h>
98 #include <netinet/icmp6.h>
99 #include <netinet/tcp_var.h>
100 
101 #include <netinet6/in6_ifattach.h>
102 #include <netinet6/in6_pcb.h>
103 #include <netinet6/ip6protosw.h>
104 #include <netinet6/ip6_var.h>
105 #include <netinet6/scope6_var.h>
106 #include <netinet6/mld6_var.h>
107 #include <netinet6/nd6.h>
108 #include <netinet6/send.h>
109 
110 #ifdef IPSEC
111 #include <netipsec/ipsec.h>
112 #include <netipsec/key.h>
113 #endif
114 
115 extern struct domain inet6domain;
116 
117 VNET_DEFINE(struct icmp6stat, icmp6stat);
118 
119 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
120 VNET_DECLARE(struct inpcbhead, ripcb);
121 VNET_DECLARE(int, icmp6errppslim);
122 static VNET_DEFINE(int, icmp6errpps_count) = 0;
123 static VNET_DEFINE(struct timeval, icmp6errppslim_last);
124 VNET_DECLARE(int, icmp6_nodeinfo);
125 
126 #define	V_ripcbinfo			VNET(ripcbinfo)
127 #define	V_ripcb				VNET(ripcb)
128 #define	V_icmp6errppslim		VNET(icmp6errppslim)
129 #define	V_icmp6errpps_count		VNET(icmp6errpps_count)
130 #define	V_icmp6errppslim_last		VNET(icmp6errppslim_last)
131 #define	V_icmp6_nodeinfo		VNET(icmp6_nodeinfo)
132 
133 static void icmp6_errcount(struct icmp6errstat *, int, int);
134 static int icmp6_rip6_input(struct mbuf **, int);
135 static int icmp6_ratelimit(const struct in6_addr *, const int, const int);
136 static const char *icmp6_redirect_diag __P((struct in6_addr *,
137 	struct in6_addr *, struct in6_addr *));
138 static struct mbuf *ni6_input(struct mbuf *, int);
139 static struct mbuf *ni6_nametodns(const char *, int, int);
140 static int ni6_dnsmatch(const char *, int, const char *, int);
141 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *,
142 			  struct ifnet **, struct in6_addr *));
143 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
144 				struct ifnet *, int));
145 static int icmp6_notify_error(struct mbuf **, int, int, int);
146 
147 /*
148  * Kernel module interface for updating icmp6stat.  The argument is an index
149  * into icmp6stat treated as an array of u_quad_t.  While this encodes the
150  * general layout of icmp6stat into the caller, it doesn't encode its
151  * location, so that future changes to add, for example, per-CPU stats
152  * support won't cause binary compatibility problems for kernel modules.
153  */
154 void
155 kmod_icmp6stat_inc(int statnum)
156 {
157 
158 	(*((u_quad_t *)&V_icmp6stat + statnum))++;
159 }
160 
161 static void
162 icmp6_errcount(struct icmp6errstat *stat, int type, int code)
163 {
164 	switch (type) {
165 	case ICMP6_DST_UNREACH:
166 		switch (code) {
167 		case ICMP6_DST_UNREACH_NOROUTE:
168 			stat->icp6errs_dst_unreach_noroute++;
169 			return;
170 		case ICMP6_DST_UNREACH_ADMIN:
171 			stat->icp6errs_dst_unreach_admin++;
172 			return;
173 		case ICMP6_DST_UNREACH_BEYONDSCOPE:
174 			stat->icp6errs_dst_unreach_beyondscope++;
175 			return;
176 		case ICMP6_DST_UNREACH_ADDR:
177 			stat->icp6errs_dst_unreach_addr++;
178 			return;
179 		case ICMP6_DST_UNREACH_NOPORT:
180 			stat->icp6errs_dst_unreach_noport++;
181 			return;
182 		}
183 		break;
184 	case ICMP6_PACKET_TOO_BIG:
185 		stat->icp6errs_packet_too_big++;
186 		return;
187 	case ICMP6_TIME_EXCEEDED:
188 		switch (code) {
189 		case ICMP6_TIME_EXCEED_TRANSIT:
190 			stat->icp6errs_time_exceed_transit++;
191 			return;
192 		case ICMP6_TIME_EXCEED_REASSEMBLY:
193 			stat->icp6errs_time_exceed_reassembly++;
194 			return;
195 		}
196 		break;
197 	case ICMP6_PARAM_PROB:
198 		switch (code) {
199 		case ICMP6_PARAMPROB_HEADER:
200 			stat->icp6errs_paramprob_header++;
201 			return;
202 		case ICMP6_PARAMPROB_NEXTHEADER:
203 			stat->icp6errs_paramprob_nextheader++;
204 			return;
205 		case ICMP6_PARAMPROB_OPTION:
206 			stat->icp6errs_paramprob_option++;
207 			return;
208 		}
209 		break;
210 	case ND_REDIRECT:
211 		stat->icp6errs_redirect++;
212 		return;
213 	}
214 	stat->icp6errs_unknown++;
215 }
216 
217 /*
218  * A wrapper function for icmp6_error() necessary when the erroneous packet
219  * may not contain enough scope zone information.
220  */
221 void
222 icmp6_error2(struct mbuf *m, int type, int code, int param,
223     struct ifnet *ifp)
224 {
225 	struct ip6_hdr *ip6;
226 
227 	if (ifp == NULL)
228 		return;
229 
230 #ifndef PULLDOWN_TEST
231 	IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
232 #else
233 	if (m->m_len < sizeof(struct ip6_hdr)) {
234 		m = m_pullup(m, sizeof(struct ip6_hdr));
235 		if (m == NULL)
236 			return;
237 	}
238 #endif
239 
240 	ip6 = mtod(m, struct ip6_hdr *);
241 
242 	if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
243 		return;
244 	if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
245 		return;
246 
247 	icmp6_error(m, type, code, param);
248 }
249 
250 /*
251  * Generate an error packet of type error in response to bad IP6 packet.
252  */
253 void
254 icmp6_error(struct mbuf *m, int type, int code, int param)
255 {
256 	struct ip6_hdr *oip6, *nip6;
257 	struct icmp6_hdr *icmp6;
258 	u_int preplen;
259 	int off;
260 	int nxt;
261 
262 	ICMP6STAT_INC(icp6s_error);
263 
264 	/* count per-type-code statistics */
265 	icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, type, code);
266 
267 #ifdef M_DECRYPTED	/*not openbsd*/
268 	if (m->m_flags & M_DECRYPTED) {
269 		ICMP6STAT_INC(icp6s_canterror);
270 		goto freeit;
271 	}
272 #endif
273 
274 #ifndef PULLDOWN_TEST
275 	IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
276 #else
277 	if (m->m_len < sizeof(struct ip6_hdr)) {
278 		m = m_pullup(m, sizeof(struct ip6_hdr));
279 		if (m == NULL)
280 			return;
281 	}
282 #endif
283 	oip6 = mtod(m, struct ip6_hdr *);
284 
285 	/*
286 	 * If the destination address of the erroneous packet is a multicast
287 	 * address, or the packet was sent using link-layer multicast,
288 	 * we should basically suppress sending an error (RFC 2463, Section
289 	 * 2.4).
290 	 * We have two exceptions (the item e.2 in that section):
291 	 * - the Packet Too Big message can be sent for path MTU discovery.
292 	 * - the Parameter Problem Message that can be allowed an icmp6 error
293 	 *   in the option type field.  This check has been done in
294 	 *   ip6_unknown_opt(), so we can just check the type and code.
295 	 */
296 	if ((m->m_flags & (M_BCAST|M_MCAST) ||
297 	     IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
298 	    (type != ICMP6_PACKET_TOO_BIG &&
299 	     (type != ICMP6_PARAM_PROB ||
300 	      code != ICMP6_PARAMPROB_OPTION)))
301 		goto freeit;
302 
303 	/*
304 	 * RFC 2463, 2.4 (e.5): source address check.
305 	 * XXX: the case of anycast source?
306 	 */
307 	if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
308 	    IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
309 		goto freeit;
310 
311 	/*
312 	 * If we are about to send ICMPv6 against ICMPv6 error/redirect,
313 	 * don't do it.
314 	 */
315 	nxt = -1;
316 	off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
317 	if (off >= 0 && nxt == IPPROTO_ICMPV6) {
318 		struct icmp6_hdr *icp;
319 
320 #ifndef PULLDOWN_TEST
321 		IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
322 		icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
323 #else
324 		IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
325 			sizeof(*icp));
326 		if (icp == NULL) {
327 			ICMP6STAT_INC(icp6s_tooshort);
328 			return;
329 		}
330 #endif
331 		if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
332 		    icp->icmp6_type == ND_REDIRECT) {
333 			/*
334 			 * ICMPv6 error
335 			 * Special case: for redirect (which is
336 			 * informational) we must not send icmp6 error.
337 			 */
338 			ICMP6STAT_INC(icp6s_canterror);
339 			goto freeit;
340 		} else {
341 			/* ICMPv6 informational - send the error */
342 		}
343 	} else {
344 		/* non-ICMPv6 - send the error */
345 	}
346 
347 	oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
348 
349 	/* Finally, do rate limitation check. */
350 	if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
351 		ICMP6STAT_INC(icp6s_toofreq);
352 		goto freeit;
353 	}
354 
355 	/*
356 	 * OK, ICMP6 can be generated.
357 	 */
358 
359 	if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
360 		m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
361 
362 	preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
363 	M_PREPEND(m, preplen, M_DONTWAIT);
364 	if (m && m->m_len < preplen)
365 		m = m_pullup(m, preplen);
366 	if (m == NULL) {
367 		nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
368 		return;
369 	}
370 
371 	nip6 = mtod(m, struct ip6_hdr *);
372 	nip6->ip6_src  = oip6->ip6_src;
373 	nip6->ip6_dst  = oip6->ip6_dst;
374 
375 	in6_clearscope(&oip6->ip6_src);
376 	in6_clearscope(&oip6->ip6_dst);
377 
378 	icmp6 = (struct icmp6_hdr *)(nip6 + 1);
379 	icmp6->icmp6_type = type;
380 	icmp6->icmp6_code = code;
381 	icmp6->icmp6_pptr = htonl((u_int32_t)param);
382 
383 	/*
384 	 * icmp6_reflect() is designed to be in the input path.
385 	 * icmp6_error() can be called from both input and output path,
386 	 * and if we are in output path rcvif could contain bogus value.
387 	 * clear m->m_pkthdr.rcvif for safety, we should have enough scope
388 	 * information in ip header (nip6).
389 	 */
390 	m->m_pkthdr.rcvif = NULL;
391 
392 	ICMP6STAT_INC(icp6s_outhist[type]);
393 	icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
394 
395 	return;
396 
397   freeit:
398 	/*
399 	 * If we can't tell whether or not we can generate ICMP6, free it.
400 	 */
401 	m_freem(m);
402 }
403 
404 /*
405  * Process a received ICMP6 message.
406  */
407 int
408 icmp6_input(struct mbuf **mp, int *offp, int proto)
409 {
410 	struct mbuf *m = *mp, *n;
411 	struct ifnet *ifp;
412 	struct ip6_hdr *ip6, *nip6;
413 	struct icmp6_hdr *icmp6, *nicmp6;
414 	int off = *offp;
415 	int icmp6len = m->m_pkthdr.len - *offp;
416 	int code, sum, noff;
417 	char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
418 	int ip6len, error;
419 
420 	ifp = m->m_pkthdr.rcvif;
421 
422 #ifndef PULLDOWN_TEST
423 	IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
424 	/* m might change if M_LOOP.  So, call mtod after this */
425 #endif
426 
427 	/*
428 	 * Locate icmp6 structure in mbuf, and check
429 	 * that not corrupted and of at least minimum length
430 	 */
431 
432 	ip6 = mtod(m, struct ip6_hdr *);
433 	ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
434 	if (icmp6len < sizeof(struct icmp6_hdr)) {
435 		ICMP6STAT_INC(icp6s_tooshort);
436 		goto freeit;
437 	}
438 
439 	/*
440 	 * Check multicast group membership.
441 	 * Note: SSM filters are not applied for ICMPv6 traffic.
442 	 */
443 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
444 		struct in6_multi	*inm;
445 
446 		inm = in6m_lookup(ifp, &ip6->ip6_dst);
447 		if (inm == NULL) {
448 			IP6STAT_INC(ip6s_notmember);
449 			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
450 			goto freeit;
451 		}
452 	}
453 
454 	/*
455 	 * calculate the checksum
456 	 */
457 #ifndef PULLDOWN_TEST
458 	icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
459 #else
460 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
461 	if (icmp6 == NULL) {
462 		ICMP6STAT_INC(icp6s_tooshort);
463 		return IPPROTO_DONE;
464 	}
465 #endif
466 	code = icmp6->icmp6_code;
467 
468 	if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
469 		nd6log((LOG_ERR,
470 		    "ICMP6 checksum error(%d|%x) %s\n",
471 		    icmp6->icmp6_type, sum,
472 		    ip6_sprintf(ip6bufs, &ip6->ip6_src)));
473 		ICMP6STAT_INC(icp6s_checksum);
474 		goto freeit;
475 	}
476 
477 	if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
478 		/*
479 		 * Deliver very specific ICMP6 type only.
480 		 * This is important to deliver TOOBIG.  Otherwise PMTUD
481 		 * will not work.
482 		 */
483 		switch (icmp6->icmp6_type) {
484 		case ICMP6_DST_UNREACH:
485 		case ICMP6_PACKET_TOO_BIG:
486 		case ICMP6_TIME_EXCEEDED:
487 			break;
488 		default:
489 			goto freeit;
490 		}
491 	}
492 
493 	ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]);
494 	icmp6_ifstat_inc(ifp, ifs6_in_msg);
495 	if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
496 		icmp6_ifstat_inc(ifp, ifs6_in_error);
497 
498 	switch (icmp6->icmp6_type) {
499 	case ICMP6_DST_UNREACH:
500 		icmp6_ifstat_inc(ifp, ifs6_in_dstunreach);
501 		switch (code) {
502 		case ICMP6_DST_UNREACH_NOROUTE:
503 			code = PRC_UNREACH_NET;
504 			break;
505 		case ICMP6_DST_UNREACH_ADMIN:
506 			icmp6_ifstat_inc(ifp, ifs6_in_adminprohib);
507 			code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
508 			break;
509 		case ICMP6_DST_UNREACH_ADDR:
510 			code = PRC_HOSTDEAD;
511 			break;
512 		case ICMP6_DST_UNREACH_BEYONDSCOPE:
513 			/* I mean "source address was incorrect." */
514 			code = PRC_PARAMPROB;
515 			break;
516 		case ICMP6_DST_UNREACH_NOPORT:
517 			code = PRC_UNREACH_PORT;
518 			break;
519 		default:
520 			goto badcode;
521 		}
522 		goto deliver;
523 		break;
524 
525 	case ICMP6_PACKET_TOO_BIG:
526 		icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);
527 
528 		/* validation is made in icmp6_mtudisc_update */
529 
530 		code = PRC_MSGSIZE;
531 
532 		/*
533 		 * Updating the path MTU will be done after examining
534 		 * intermediate extension headers.
535 		 */
536 		goto deliver;
537 		break;
538 
539 	case ICMP6_TIME_EXCEEDED:
540 		icmp6_ifstat_inc(ifp, ifs6_in_timeexceed);
541 		switch (code) {
542 		case ICMP6_TIME_EXCEED_TRANSIT:
543 			code = PRC_TIMXCEED_INTRANS;
544 			break;
545 		case ICMP6_TIME_EXCEED_REASSEMBLY:
546 			code = PRC_TIMXCEED_REASS;
547 			break;
548 		default:
549 			goto badcode;
550 		}
551 		goto deliver;
552 		break;
553 
554 	case ICMP6_PARAM_PROB:
555 		icmp6_ifstat_inc(ifp, ifs6_in_paramprob);
556 		switch (code) {
557 		case ICMP6_PARAMPROB_NEXTHEADER:
558 			code = PRC_UNREACH_PROTOCOL;
559 			break;
560 		case ICMP6_PARAMPROB_HEADER:
561 		case ICMP6_PARAMPROB_OPTION:
562 			code = PRC_PARAMPROB;
563 			break;
564 		default:
565 			goto badcode;
566 		}
567 		goto deliver;
568 		break;
569 
570 	case ICMP6_ECHO_REQUEST:
571 		icmp6_ifstat_inc(ifp, ifs6_in_echo);
572 		if (code != 0)
573 			goto badcode;
574 		if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
575 			/* Give up remote */
576 			break;
577 		}
578 		if ((n->m_flags & M_EXT) != 0
579 		 || n->m_len < off + sizeof(struct icmp6_hdr)) {
580 			struct mbuf *n0 = n;
581 			const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
582 			int n0len;
583 
584 			MGETHDR(n, M_DONTWAIT, n0->m_type);
585 			n0len = n0->m_pkthdr.len;	/* save for use below */
586 			if (n)
587 				M_MOVE_PKTHDR(n, n0);
588 			if (n && maxlen >= MHLEN) {
589 				MCLGET(n, M_DONTWAIT);
590 				if ((n->m_flags & M_EXT) == 0) {
591 					m_free(n);
592 					n = NULL;
593 				}
594 			}
595 			if (n == NULL) {
596 				/* Give up remote */
597 				m_freem(n0);
598 				break;
599 			}
600 			/*
601 			 * Copy IPv6 and ICMPv6 only.
602 			 */
603 			nip6 = mtod(n, struct ip6_hdr *);
604 			bcopy(ip6, nip6, sizeof(struct ip6_hdr));
605 			nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
606 			bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
607 			noff = sizeof(struct ip6_hdr);
608 			/* new mbuf contains only ipv6+icmpv6 headers */
609 			n->m_len = noff + sizeof(struct icmp6_hdr);
610 			/*
611 			 * Adjust mbuf.  ip6_plen will be adjusted in
612 			 * ip6_output().
613 			 */
614 			m_adj(n0, off + sizeof(struct icmp6_hdr));
615 			/* recalculate complete packet size */
616 			n->m_pkthdr.len = n0len + (noff - off);
617 			n->m_next = n0;
618 		} else {
619 			nip6 = mtod(n, struct ip6_hdr *);
620 			IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
621 			    sizeof(*nicmp6));
622 			noff = off;
623 		}
624 		nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
625 		nicmp6->icmp6_code = 0;
626 		if (n) {
627 			ICMP6STAT_INC(icp6s_reflect);
628 			ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]);
629 			icmp6_reflect(n, noff);
630 		}
631 		break;
632 
633 	case ICMP6_ECHO_REPLY:
634 		icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
635 		if (code != 0)
636 			goto badcode;
637 		break;
638 
639 	case MLD_LISTENER_QUERY:
640 	case MLD_LISTENER_REPORT:
641 	case MLD_LISTENER_DONE:
642 	case MLDV2_LISTENER_REPORT:
643 		/*
644 		 * Drop MLD traffic which is not link-local, has a hop limit
645 		 * of greater than 1 hop, or which does not have the
646 		 * IPv6 HBH Router Alert option.
647 		 * As IPv6 HBH options are stripped in ip6_input() we must
648 		 * check an mbuf header flag.
649 		 * XXX Should we also sanity check that these messages
650 		 * were directed to a link-local multicast prefix?
651 		 */
652 		if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0)
653 			goto freeit;
654 		if (mld_input(m, off, icmp6len) != 0)
655 			return (IPPROTO_DONE);
656 		/* m stays. */
657 		break;
658 
659 	case ICMP6_WRUREQUEST:	/* ICMP6_FQDN_QUERY */
660 	    {
661 		enum { WRU, FQDN } mode;
662 
663 		if (!V_icmp6_nodeinfo)
664 			break;
665 
666 		if (icmp6len == sizeof(struct icmp6_hdr) + 4)
667 			mode = WRU;
668 		else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
669 			mode = FQDN;
670 		else
671 			goto badlen;
672 
673 		if (mode == FQDN) {
674 #ifndef PULLDOWN_TEST
675 			IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
676 			    IPPROTO_DONE);
677 #endif
678 			n = m_copy(m, 0, M_COPYALL);
679 			if (n)
680 				n = ni6_input(n, off);
681 			/* XXX meaningless if n == NULL */
682 			noff = sizeof(struct ip6_hdr);
683 		} else {
684 			struct prison *pr;
685 			u_char *p;
686 			int maxlen, maxhlen, hlen;
687 
688 			/*
689 			 * XXX: this combination of flags is pointless,
690 			 * but should we keep this for compatibility?
691 			 */
692 			if ((V_icmp6_nodeinfo & 5) != 5)
693 				break;
694 
695 			if (code != 0)
696 				goto badcode;
697 			maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
698 			if (maxlen >= MCLBYTES) {
699 				/* Give up remote */
700 				break;
701 			}
702 			MGETHDR(n, M_DONTWAIT, m->m_type);
703 			if (n && maxlen > MHLEN) {
704 				MCLGET(n, M_DONTWAIT);
705 				if ((n->m_flags & M_EXT) == 0) {
706 					m_free(n);
707 					n = NULL;
708 				}
709 			}
710 			if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) {
711 				/*
712 				 * Previous code did a blind M_COPY_PKTHDR
713 				 * and said "just for rcvif".  If true, then
714 				 * we could tolerate the dup failing (due to
715 				 * the deep copy of the tag chain).  For now
716 				 * be conservative and just fail.
717 				 */
718 				m_free(n);
719 				n = NULL;
720 			}
721 			if (n == NULL) {
722 				/* Give up remote */
723 				break;
724 			}
725 			n->m_pkthdr.rcvif = NULL;
726 			n->m_len = 0;
727 			maxhlen = M_TRAILINGSPACE(n) - maxlen;
728 			pr = curthread->td_ucred->cr_prison;
729 			mtx_lock(&pr->pr_mtx);
730 			hlen = strlen(pr->pr_hostname);
731 			if (maxhlen > hlen)
732 				maxhlen = hlen;
733 			/*
734 			 * Copy IPv6 and ICMPv6 only.
735 			 */
736 			nip6 = mtod(n, struct ip6_hdr *);
737 			bcopy(ip6, nip6, sizeof(struct ip6_hdr));
738 			nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
739 			bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
740 			p = (u_char *)(nicmp6 + 1);
741 			bzero(p, 4);
742 			/* meaningless TTL */
743 			bcopy(pr->pr_hostname, p + 4, maxhlen);
744 			mtx_unlock(&pr->pr_mtx);
745 			noff = sizeof(struct ip6_hdr);
746 			n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
747 				sizeof(struct icmp6_hdr) + 4 + maxhlen;
748 			nicmp6->icmp6_type = ICMP6_WRUREPLY;
749 			nicmp6->icmp6_code = 0;
750 		}
751 		if (n) {
752 			ICMP6STAT_INC(icp6s_reflect);
753 			ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
754 			icmp6_reflect(n, noff);
755 		}
756 		break;
757 	    }
758 
759 	case ICMP6_WRUREPLY:
760 		if (code != 0)
761 			goto badcode;
762 		break;
763 
764 	case ND_ROUTER_SOLICIT:
765 		icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
766 		if (code != 0)
767 			goto badcode;
768 		if (icmp6len < sizeof(struct nd_router_solicit))
769 			goto badlen;
770 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
771 			/* give up local */
772 
773 			/* Send incoming SeND packet to user space. */
774 			if (send_sendso_input_hook != NULL) {
775 				IP6_EXTHDR_CHECK(m, off,
776 				    icmp6len, IPPROTO_DONE);
777 				error = send_sendso_input_hook(m, ifp,
778 				    SND_IN, ip6len);
779 				/* -1 == no app on SEND socket */
780 				if (error == 0)
781 					return (IPPROTO_DONE);
782 				nd6_rs_input(m, off, icmp6len);
783 			} else
784 				nd6_rs_input(m, off, icmp6len);
785 			m = NULL;
786 			goto freeit;
787 		}
788 		if (send_sendso_input_hook != NULL) {
789 			IP6_EXTHDR_CHECK(n, off,
790 			    icmp6len, IPPROTO_DONE);
791                         error = send_sendso_input_hook(n, ifp,
792 			    SND_IN, ip6len);
793 			if (error == 0)
794 				goto freeit;
795 			/* -1 == no app on SEND socket */
796 			nd6_rs_input(n, off, icmp6len);
797 		} else
798 			nd6_rs_input(n, off, icmp6len);
799 		/* m stays. */
800 		break;
801 
802 	case ND_ROUTER_ADVERT:
803 		icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
804 		if (code != 0)
805 			goto badcode;
806 		if (icmp6len < sizeof(struct nd_router_advert))
807 			goto badlen;
808 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
809 
810 			/* Send incoming SeND-protected/ND packet to user space. */
811 			if (send_sendso_input_hook != NULL) {
812 				error = send_sendso_input_hook(m, ifp,
813 				    SND_IN, ip6len);
814 				if (error == 0)
815 					return (IPPROTO_DONE);
816 				nd6_ra_input(m, off, icmp6len);
817 			} else
818 				nd6_ra_input(m, off, icmp6len);
819 			m = NULL;
820 			goto freeit;
821 		}
822 		if (send_sendso_input_hook != NULL) {
823 			error = send_sendso_input_hook(n, ifp,
824 			    SND_IN, ip6len);
825 			if (error == 0)
826 				goto freeit;
827 			nd6_ra_input(n, off, icmp6len);
828 		} else
829 			nd6_ra_input(n, off, icmp6len);
830 		/* m stays. */
831 		break;
832 
833 	case ND_NEIGHBOR_SOLICIT:
834 		icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
835 		if (code != 0)
836 			goto badcode;
837 		if (icmp6len < sizeof(struct nd_neighbor_solicit))
838 			goto badlen;
839 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
840 			if (send_sendso_input_hook != NULL) {
841 				error = send_sendso_input_hook(m, ifp,
842 				    SND_IN, ip6len);
843 				if (error == 0)
844 					return (IPPROTO_DONE);
845 				nd6_ns_input(m, off, icmp6len);
846 			} else
847 				nd6_ns_input(m, off, icmp6len);
848 			m = NULL;
849 			goto freeit;
850 		}
851 		if (send_sendso_input_hook != NULL) {
852 			error = send_sendso_input_hook(n, ifp,
853 			    SND_IN, ip6len);
854 			if (error == 0)
855 				goto freeit;
856 			nd6_ns_input(n, off, icmp6len);
857 		} else
858 			nd6_ns_input(n, off, icmp6len);
859 		/* m stays. */
860 		break;
861 
862 	case ND_NEIGHBOR_ADVERT:
863 		icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
864 		if (code != 0)
865 			goto badcode;
866 		if (icmp6len < sizeof(struct nd_neighbor_advert))
867 			goto badlen;
868 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
869 
870 			/* Send incoming SeND-protected/ND packet to user space. */
871 			if (send_sendso_input_hook != NULL) {
872 				error = send_sendso_input_hook(m, ifp,
873 				    SND_IN, ip6len);
874 				if (error == 0)
875 					return (IPPROTO_DONE);
876 				nd6_na_input(m, off, icmp6len);
877 			} else
878 				nd6_na_input(m, off, icmp6len);
879 			m = NULL;
880 			goto freeit;
881 		}
882 		if (send_sendso_input_hook != NULL) {
883 			error = send_sendso_input_hook(n, ifp,
884 			    SND_IN, ip6len);
885 			if (error == 0)
886 				goto freeit;
887 			nd6_na_input(n, off, icmp6len);
888 		} else
889 			nd6_na_input(n, off, icmp6len);
890 		/* m stays. */
891 		break;
892 
893 	case ND_REDIRECT:
894 		icmp6_ifstat_inc(ifp, ifs6_in_redirect);
895 		if (code != 0)
896 			goto badcode;
897 		if (icmp6len < sizeof(struct nd_redirect))
898 			goto badlen;
899 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
900 			if (send_sendso_input_hook != NULL) {
901 				error = send_sendso_input_hook(m, ifp,
902 				    SND_IN, ip6len);
903 		 		if (error == 0)
904 					return (IPPROTO_DONE);
905 			    icmp6_redirect_input(m, off);
906 			} else
907 				icmp6_redirect_input(m, off);
908 			m = NULL;
909 			goto freeit;
910 		}
911 		if (send_sendso_input_hook != NULL) {
912 			error = send_sendso_input_hook(n, ifp,
913 			    SND_IN, ip6len);
914 			if (error == 0)
915 				goto freeit;
916 			icmp6_redirect_input(n, off);
917 		} else
918 			icmp6_redirect_input(n, off);
919 		/* m stays. */
920 		break;
921 
922 	case ICMP6_ROUTER_RENUMBERING:
923 		if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
924 		    code != ICMP6_ROUTER_RENUMBERING_RESULT)
925 			goto badcode;
926 		if (icmp6len < sizeof(struct icmp6_router_renum))
927 			goto badlen;
928 		break;
929 
930 	default:
931 		nd6log((LOG_DEBUG,
932 		    "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
933 		    icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
934 		    ip6_sprintf(ip6bufd, &ip6->ip6_dst),
935 		    ifp ? ifp->if_index : 0));
936 		if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
937 			/* ICMPv6 error: MUST deliver it by spec... */
938 			code = PRC_NCMDS;
939 			/* deliver */
940 		} else {
941 			/* ICMPv6 informational: MUST not deliver */
942 			break;
943 		}
944 	deliver:
945 		if (icmp6_notify_error(&m, off, icmp6len, code) != 0) {
946 			/* In this case, m should've been freed. */
947 			return (IPPROTO_DONE);
948 		}
949 		break;
950 
951 	badcode:
952 		ICMP6STAT_INC(icp6s_badcode);
953 		break;
954 
955 	badlen:
956 		ICMP6STAT_INC(icp6s_badlen);
957 		break;
958 	}
959 
960 	/* deliver the packet to appropriate sockets */
961 	icmp6_rip6_input(&m, *offp);
962 
963 	return IPPROTO_DONE;
964 
965  freeit:
966 	m_freem(m);
967 	return IPPROTO_DONE;
968 }
969 
970 static int
971 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
972 {
973 	struct mbuf *m = *mp;
974 	struct icmp6_hdr *icmp6;
975 	struct ip6_hdr *eip6;
976 	u_int32_t notifymtu;
977 	struct sockaddr_in6 icmp6src, icmp6dst;
978 
979 	if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
980 		ICMP6STAT_INC(icp6s_tooshort);
981 		goto freeit;
982 	}
983 #ifndef PULLDOWN_TEST
984 	IP6_EXTHDR_CHECK(m, off,
985 	    sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
986 	icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
987 #else
988 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
989 	    sizeof(*icmp6) + sizeof(struct ip6_hdr));
990 	if (icmp6 == NULL) {
991 		ICMP6STAT_INC(icp6s_tooshort);
992 		return (-1);
993 	}
994 #endif
995 	eip6 = (struct ip6_hdr *)(icmp6 + 1);
996 
997 	/* Detect the upper level protocol */
998 	{
999 		void (*ctlfunc)(int, struct sockaddr *, void *);
1000 		u_int8_t nxt = eip6->ip6_nxt;
1001 		int eoff = off + sizeof(struct icmp6_hdr) +
1002 		    sizeof(struct ip6_hdr);
1003 		struct ip6ctlparam ip6cp;
1004 		struct in6_addr *finaldst = NULL;
1005 		int icmp6type = icmp6->icmp6_type;
1006 		struct ip6_frag *fh;
1007 		struct ip6_rthdr *rth;
1008 		struct ip6_rthdr0 *rth0;
1009 		int rthlen;
1010 
1011 		while (1) { /* XXX: should avoid infinite loop explicitly? */
1012 			struct ip6_ext *eh;
1013 
1014 			switch (nxt) {
1015 			case IPPROTO_HOPOPTS:
1016 			case IPPROTO_DSTOPTS:
1017 			case IPPROTO_AH:
1018 #ifndef PULLDOWN_TEST
1019 				IP6_EXTHDR_CHECK(m, 0,
1020 				    eoff + sizeof(struct ip6_ext), -1);
1021 				eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
1022 #else
1023 				IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
1024 				    eoff, sizeof(*eh));
1025 				if (eh == NULL) {
1026 					ICMP6STAT_INC(icp6s_tooshort);
1027 					return (-1);
1028 				}
1029 #endif
1030 
1031 				if (nxt == IPPROTO_AH)
1032 					eoff += (eh->ip6e_len + 2) << 2;
1033 				else
1034 					eoff += (eh->ip6e_len + 1) << 3;
1035 				nxt = eh->ip6e_nxt;
1036 				break;
1037 			case IPPROTO_ROUTING:
1038 				/*
1039 				 * When the erroneous packet contains a
1040 				 * routing header, we should examine the
1041 				 * header to determine the final destination.
1042 				 * Otherwise, we can't properly update
1043 				 * information that depends on the final
1044 				 * destination (e.g. path MTU).
1045 				 */
1046 #ifndef PULLDOWN_TEST
1047 				IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
1048 				rth = (struct ip6_rthdr *)
1049 				    (mtod(m, caddr_t) + eoff);
1050 #else
1051 				IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
1052 				    eoff, sizeof(*rth));
1053 				if (rth == NULL) {
1054 					ICMP6STAT_INC(icp6s_tooshort);
1055 					return (-1);
1056 				}
1057 #endif
1058 				rthlen = (rth->ip6r_len + 1) << 3;
1059 				/*
1060 				 * XXX: currently there is no
1061 				 * officially defined type other
1062 				 * than type-0.
1063 				 * Note that if the segment left field
1064 				 * is 0, all intermediate hops must
1065 				 * have been passed.
1066 				 */
1067 				if (rth->ip6r_segleft &&
1068 				    rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
1069 					int hops;
1070 
1071 #ifndef PULLDOWN_TEST
1072 					IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
1073 					rth0 = (struct ip6_rthdr0 *)
1074 					    (mtod(m, caddr_t) + eoff);
1075 #else
1076 					IP6_EXTHDR_GET(rth0,
1077 					    struct ip6_rthdr0 *, m,
1078 					    eoff, rthlen);
1079 					if (rth0 == NULL) {
1080 						ICMP6STAT_INC(icp6s_tooshort);
1081 						return (-1);
1082 					}
1083 #endif
1084 					/* just ignore a bogus header */
1085 					if ((rth0->ip6r0_len % 2) == 0 &&
1086 					    (hops = rth0->ip6r0_len/2))
1087 						finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
1088 				}
1089 				eoff += rthlen;
1090 				nxt = rth->ip6r_nxt;
1091 				break;
1092 			case IPPROTO_FRAGMENT:
1093 #ifndef PULLDOWN_TEST
1094 				IP6_EXTHDR_CHECK(m, 0, eoff +
1095 				    sizeof(struct ip6_frag), -1);
1096 				fh = (struct ip6_frag *)(mtod(m, caddr_t) +
1097 				    eoff);
1098 #else
1099 				IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
1100 				    eoff, sizeof(*fh));
1101 				if (fh == NULL) {
1102 					ICMP6STAT_INC(icp6s_tooshort);
1103 					return (-1);
1104 				}
1105 #endif
1106 				/*
1107 				 * Data after a fragment header is meaningless
1108 				 * unless it is the first fragment, but
1109 				 * we'll go to the notify label for path MTU
1110 				 * discovery.
1111 				 */
1112 				if (fh->ip6f_offlg & IP6F_OFF_MASK)
1113 					goto notify;
1114 
1115 				eoff += sizeof(struct ip6_frag);
1116 				nxt = fh->ip6f_nxt;
1117 				break;
1118 			default:
1119 				/*
1120 				 * This case includes ESP and the No Next
1121 				 * Header.  In such cases going to the notify
1122 				 * label does not have any meaning
1123 				 * (i.e. ctlfunc will be NULL), but we go
1124 				 * anyway since we might have to update
1125 				 * path MTU information.
1126 				 */
1127 				goto notify;
1128 			}
1129 		}
1130 	  notify:
1131 #ifndef PULLDOWN_TEST
1132 		icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1133 #else
1134 		IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1135 		    sizeof(*icmp6) + sizeof(struct ip6_hdr));
1136 		if (icmp6 == NULL) {
1137 			ICMP6STAT_INC(icp6s_tooshort);
1138 			return (-1);
1139 		}
1140 #endif
1141 
1142 		/*
1143 		 * retrieve parameters from the inner IPv6 header, and convert
1144 		 * them into sockaddr structures.
1145 		 * XXX: there is no guarantee that the source or destination
1146 		 * addresses of the inner packet are in the same scope as
1147 		 * the addresses of the icmp packet.  But there is no other
1148 		 * way to determine the zone.
1149 		 */
1150 		eip6 = (struct ip6_hdr *)(icmp6 + 1);
1151 
1152 		bzero(&icmp6dst, sizeof(icmp6dst));
1153 		icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1154 		icmp6dst.sin6_family = AF_INET6;
1155 		if (finaldst == NULL)
1156 			icmp6dst.sin6_addr = eip6->ip6_dst;
1157 		else
1158 			icmp6dst.sin6_addr = *finaldst;
1159 		if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1160 			goto freeit;
1161 		bzero(&icmp6src, sizeof(icmp6src));
1162 		icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1163 		icmp6src.sin6_family = AF_INET6;
1164 		icmp6src.sin6_addr = eip6->ip6_src;
1165 		if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1166 			goto freeit;
1167 		icmp6src.sin6_flowinfo =
1168 		    (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1169 
1170 		if (finaldst == NULL)
1171 			finaldst = &eip6->ip6_dst;
1172 		ip6cp.ip6c_m = m;
1173 		ip6cp.ip6c_icmp6 = icmp6;
1174 		ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1175 		ip6cp.ip6c_off = eoff;
1176 		ip6cp.ip6c_finaldst = finaldst;
1177 		ip6cp.ip6c_src = &icmp6src;
1178 		ip6cp.ip6c_nxt = nxt;
1179 
1180 		if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1181 			notifymtu = ntohl(icmp6->icmp6_mtu);
1182 			ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1183 			icmp6_mtudisc_update(&ip6cp, 1);	/*XXX*/
1184 		}
1185 
1186 		ctlfunc = (void (*)(int, struct sockaddr *, void *))
1187 		    (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1188 		if (ctlfunc) {
1189 			(void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1190 			    &ip6cp);
1191 		}
1192 	}
1193 	*mp = m;
1194 	return (0);
1195 
1196   freeit:
1197 	m_freem(m);
1198 	return (-1);
1199 }
1200 
1201 void
1202 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1203 {
1204 	struct in6_addr *dst = ip6cp->ip6c_finaldst;
1205 	struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1206 	struct mbuf *m = ip6cp->ip6c_m;	/* will be necessary for scope issue */
1207 	u_int mtu = ntohl(icmp6->icmp6_mtu);
1208 	struct in_conninfo inc;
1209 
1210 #if 0
1211 	/*
1212 	 * RFC2460 section 5, last paragraph.
1213 	 * even though minimum link MTU for IPv6 is IPV6_MMTU,
1214 	 * we may see ICMPv6 too big with mtu < IPV6_MMTU
1215 	 * due to packet translator in the middle.
1216 	 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1217 	 * special handling.
1218 	 */
1219 	if (mtu < IPV6_MMTU)
1220 		return;
1221 #endif
1222 
1223 	/*
1224 	 * we reject ICMPv6 too big with abnormally small value.
1225 	 * XXX what is the good definition of "abnormally small"?
1226 	 */
1227 	if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1228 		return;
1229 
1230 	if (!validated)
1231 		return;
1232 
1233 	/*
1234 	 * In case the suggested mtu is less than IPV6_MMTU, we
1235 	 * only need to remember that it was for above mentioned
1236 	 * "alwaysfrag" case.
1237 	 * Try to be as close to the spec as possible.
1238 	 */
1239 	if (mtu < IPV6_MMTU)
1240 		mtu = IPV6_MMTU - 8;
1241 
1242 	bzero(&inc, sizeof(inc));
1243 	inc.inc_flags |= INC_ISIPV6;
1244 	inc.inc6_faddr = *dst;
1245 	if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1246 		return;
1247 
1248 	if (mtu < tcp_maxmtu6(&inc, NULL)) {
1249 		tcp_hc_updatemtu(&inc, mtu);
1250 		ICMP6STAT_INC(icp6s_pmtuchg);
1251 	}
1252 }
1253 
1254 /*
1255  * Process a Node Information Query packet, based on
1256  * draft-ietf-ipngwg-icmp-name-lookups-07.
1257  *
1258  * Spec incompatibilities:
1259  * - IPv6 Subject address handling
1260  * - IPv4 Subject address handling support missing
1261  * - Proxy reply (answer even if it's not for me)
1262  * - joins NI group address at in6_ifattach() time only, does not cope
1263  *   with hostname changes by sethostname(3)
1264  */
1265 static struct mbuf *
1266 ni6_input(struct mbuf *m, int off)
1267 {
1268 	struct icmp6_nodeinfo *ni6, *nni6;
1269 	struct mbuf *n = NULL;
1270 	struct prison *pr;
1271 	u_int16_t qtype;
1272 	int subjlen;
1273 	int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1274 	struct ni_reply_fqdn *fqdn;
1275 	int addrs;		/* for NI_QTYPE_NODEADDR */
1276 	struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1277 	struct in6_addr in6_subj; /* subject address */
1278 	struct ip6_hdr *ip6;
1279 	int oldfqdn = 0;	/* if 1, return pascal string (03 draft) */
1280 	char *subj = NULL;
1281 	struct in6_ifaddr *ia6 = NULL;
1282 
1283 	ip6 = mtod(m, struct ip6_hdr *);
1284 #ifndef PULLDOWN_TEST
1285 	ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1286 #else
1287 	IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1288 	if (ni6 == NULL) {
1289 		/* m is already reclaimed */
1290 		return (NULL);
1291 	}
1292 #endif
1293 
1294 	/*
1295 	 * Validate IPv6 source address.
1296 	 * The default configuration MUST be to refuse answering queries from
1297 	 * global-scope addresses according to RFC4602.
1298 	 * Notes:
1299 	 *  - it's not very clear what "refuse" means; this implementation
1300 	 *    simply drops it.
1301 	 *  - it's not very easy to identify global-scope (unicast) addresses
1302 	 *    since there are many prefixes for them.  It should be safer
1303 	 *    and in practice sufficient to check "all" but loopback and
1304 	 *    link-local (note that site-local unicast was deprecated and
1305 	 *    ULA is defined as global scope-wise)
1306 	 */
1307 	if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1308 	    !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1309 	    !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1310 		goto bad;
1311 
1312 	/*
1313 	 * Validate IPv6 destination address.
1314 	 *
1315 	 * The Responder must discard the Query without further processing
1316 	 * unless it is one of the Responder's unicast or anycast addresses, or
1317 	 * a link-local scope multicast address which the Responder has joined.
1318 	 * [RFC4602, Section 5.]
1319 	 */
1320 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1321 		if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1322 			goto bad;
1323 		/* else it's a link-local multicast, fine */
1324 	} else {		/* unicast or anycast */
1325 		if ((ia6 = ip6_getdstifaddr(m)) == NULL)
1326 			goto bad; /* XXX impossible */
1327 
1328 		if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1329 		    !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1330 			ifa_free(&ia6->ia_ifa);
1331 			nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1332 				"a temporary address in %s:%d",
1333 			       __FILE__, __LINE__));
1334 			goto bad;
1335 		}
1336 		ifa_free(&ia6->ia_ifa);
1337 	}
1338 
1339 	/* validate query Subject field. */
1340 	qtype = ntohs(ni6->ni_qtype);
1341 	subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1342 	switch (qtype) {
1343 	case NI_QTYPE_NOOP:
1344 	case NI_QTYPE_SUPTYPES:
1345 		/* 07 draft */
1346 		if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1347 			break;
1348 		/* FALLTHROUGH */
1349 	case NI_QTYPE_FQDN:
1350 	case NI_QTYPE_NODEADDR:
1351 	case NI_QTYPE_IPV4ADDR:
1352 		switch (ni6->ni_code) {
1353 		case ICMP6_NI_SUBJ_IPV6:
1354 #if ICMP6_NI_SUBJ_IPV6 != 0
1355 		case 0:
1356 #endif
1357 			/*
1358 			 * backward compatibility - try to accept 03 draft
1359 			 * format, where no Subject is present.
1360 			 */
1361 			if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1362 			    subjlen == 0) {
1363 				oldfqdn++;
1364 				break;
1365 			}
1366 #if ICMP6_NI_SUBJ_IPV6 != 0
1367 			if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1368 				goto bad;
1369 #endif
1370 
1371 			if (subjlen != sizeof(struct in6_addr))
1372 				goto bad;
1373 
1374 			/*
1375 			 * Validate Subject address.
1376 			 *
1377 			 * Not sure what exactly "address belongs to the node"
1378 			 * means in the spec, is it just unicast, or what?
1379 			 *
1380 			 * At this moment we consider Subject address as
1381 			 * "belong to the node" if the Subject address equals
1382 			 * to the IPv6 destination address; validation for
1383 			 * IPv6 destination address should have done enough
1384 			 * check for us.
1385 			 *
1386 			 * We do not do proxy at this moment.
1387 			 */
1388 			/* m_pulldown instead of copy? */
1389 			m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1390 			    subjlen, (caddr_t)&in6_subj);
1391 			if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1392 				goto bad;
1393 
1394 			subj = (char *)&in6_subj;
1395 			if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1396 				break;
1397 
1398 			/*
1399 			 * XXX if we are to allow other cases, we should really
1400 			 * be careful about scope here.
1401 			 * basically, we should disallow queries toward IPv6
1402 			 * destination X with subject Y,
1403 			 * if scope(X) > scope(Y).
1404 			 * if we allow scope(X) > scope(Y), it will result in
1405 			 * information leakage across scope boundary.
1406 			 */
1407 			goto bad;
1408 
1409 		case ICMP6_NI_SUBJ_FQDN:
1410 			/*
1411 			 * Validate Subject name with gethostname(3).
1412 			 *
1413 			 * The behavior may need some debate, since:
1414 			 * - we are not sure if the node has FQDN as
1415 			 *   hostname (returned by gethostname(3)).
1416 			 * - the code does wildcard match for truncated names.
1417 			 *   however, we are not sure if we want to perform
1418 			 *   wildcard match, if gethostname(3) side has
1419 			 *   truncated hostname.
1420 			 */
1421 			pr = curthread->td_ucred->cr_prison;
1422 			mtx_lock(&pr->pr_mtx);
1423 			n = ni6_nametodns(pr->pr_hostname,
1424 			    strlen(pr->pr_hostname), 0);
1425 			mtx_unlock(&pr->pr_mtx);
1426 			if (!n || n->m_next || n->m_len == 0)
1427 				goto bad;
1428 			IP6_EXTHDR_GET(subj, char *, m,
1429 			    off + sizeof(struct icmp6_nodeinfo), subjlen);
1430 			if (subj == NULL)
1431 				goto bad;
1432 			if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1433 			    n->m_len)) {
1434 				goto bad;
1435 			}
1436 			m_freem(n);
1437 			n = NULL;
1438 			break;
1439 
1440 		case ICMP6_NI_SUBJ_IPV4:	/* XXX: to be implemented? */
1441 		default:
1442 			goto bad;
1443 		}
1444 		break;
1445 	}
1446 
1447 	/* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1448 	switch (qtype) {
1449 	case NI_QTYPE_FQDN:
1450 		if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1451 			goto bad;
1452 		break;
1453 	case NI_QTYPE_NODEADDR:
1454 	case NI_QTYPE_IPV4ADDR:
1455 		if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1456 			goto bad;
1457 		break;
1458 	}
1459 
1460 	/* guess reply length */
1461 	switch (qtype) {
1462 	case NI_QTYPE_NOOP:
1463 		break;		/* no reply data */
1464 	case NI_QTYPE_SUPTYPES:
1465 		replylen += sizeof(u_int32_t);
1466 		break;
1467 	case NI_QTYPE_FQDN:
1468 		/* XXX will append an mbuf */
1469 		replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1470 		break;
1471 	case NI_QTYPE_NODEADDR:
1472 		addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1473 		if ((replylen += addrs * (sizeof(struct in6_addr) +
1474 		    sizeof(u_int32_t))) > MCLBYTES)
1475 			replylen = MCLBYTES; /* XXX: will truncate pkt later */
1476 		break;
1477 	case NI_QTYPE_IPV4ADDR:
1478 		/* unsupported - should respond with unknown Qtype? */
1479 		break;
1480 	default:
1481 		/*
1482 		 * XXX: We must return a reply with the ICMP6 code
1483 		 * `unknown Qtype' in this case.  However we regard the case
1484 		 * as an FQDN query for backward compatibility.
1485 		 * Older versions set a random value to this field,
1486 		 * so it rarely varies in the defined qtypes.
1487 		 * But the mechanism is not reliable...
1488 		 * maybe we should obsolete older versions.
1489 		 */
1490 		qtype = NI_QTYPE_FQDN;
1491 		/* XXX will append an mbuf */
1492 		replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1493 		oldfqdn++;
1494 		break;
1495 	}
1496 
1497 	/* allocate an mbuf to reply. */
1498 	MGETHDR(n, M_DONTWAIT, m->m_type);
1499 	if (n == NULL) {
1500 		m_freem(m);
1501 		return (NULL);
1502 	}
1503 	M_MOVE_PKTHDR(n, m); /* just for recvif */
1504 	if (replylen > MHLEN) {
1505 		if (replylen > MCLBYTES) {
1506 			/*
1507 			 * XXX: should we try to allocate more? But MCLBYTES
1508 			 * is probably much larger than IPV6_MMTU...
1509 			 */
1510 			goto bad;
1511 		}
1512 		MCLGET(n, M_DONTWAIT);
1513 		if ((n->m_flags & M_EXT) == 0) {
1514 			goto bad;
1515 		}
1516 	}
1517 	n->m_pkthdr.len = n->m_len = replylen;
1518 
1519 	/* copy mbuf header and IPv6 + Node Information base headers */
1520 	bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1521 	nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1522 	bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1523 
1524 	/* qtype dependent procedure */
1525 	switch (qtype) {
1526 	case NI_QTYPE_NOOP:
1527 		nni6->ni_code = ICMP6_NI_SUCCESS;
1528 		nni6->ni_flags = 0;
1529 		break;
1530 	case NI_QTYPE_SUPTYPES:
1531 	{
1532 		u_int32_t v;
1533 		nni6->ni_code = ICMP6_NI_SUCCESS;
1534 		nni6->ni_flags = htons(0x0000);	/* raw bitmap */
1535 		/* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1536 		v = (u_int32_t)htonl(0x0000000f);
1537 		bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1538 		break;
1539 	}
1540 	case NI_QTYPE_FQDN:
1541 		nni6->ni_code = ICMP6_NI_SUCCESS;
1542 		fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1543 		    sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1544 		nni6->ni_flags = 0; /* XXX: meaningless TTL */
1545 		fqdn->ni_fqdn_ttl = 0;	/* ditto. */
1546 		/*
1547 		 * XXX do we really have FQDN in hostname?
1548 		 */
1549 		pr = curthread->td_ucred->cr_prison;
1550 		mtx_lock(&pr->pr_mtx);
1551 		n->m_next = ni6_nametodns(pr->pr_hostname,
1552 		    strlen(pr->pr_hostname), oldfqdn);
1553 		mtx_unlock(&pr->pr_mtx);
1554 		if (n->m_next == NULL)
1555 			goto bad;
1556 		/* XXX we assume that n->m_next is not a chain */
1557 		if (n->m_next->m_next != NULL)
1558 			goto bad;
1559 		n->m_pkthdr.len += n->m_next->m_len;
1560 		break;
1561 	case NI_QTYPE_NODEADDR:
1562 	{
1563 		int lenlim, copied;
1564 
1565 		nni6->ni_code = ICMP6_NI_SUCCESS;
1566 		n->m_pkthdr.len = n->m_len =
1567 		    sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1568 		lenlim = M_TRAILINGSPACE(n);
1569 		copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1570 		/* XXX: reset mbuf length */
1571 		n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1572 		    sizeof(struct icmp6_nodeinfo) + copied;
1573 		break;
1574 	}
1575 	default:
1576 		break;		/* XXX impossible! */
1577 	}
1578 
1579 	nni6->ni_type = ICMP6_NI_REPLY;
1580 	m_freem(m);
1581 	return (n);
1582 
1583   bad:
1584 	m_freem(m);
1585 	if (n)
1586 		m_freem(n);
1587 	return (NULL);
1588 }
1589 
1590 /*
1591  * make a mbuf with DNS-encoded string.  no compression support.
1592  *
1593  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1594  * treated as truncated name (two \0 at the end).  this is a wild guess.
1595  *
1596  * old - return pascal string if non-zero
1597  */
1598 static struct mbuf *
1599 ni6_nametodns(const char *name, int namelen, int old)
1600 {
1601 	struct mbuf *m;
1602 	char *cp, *ep;
1603 	const char *p, *q;
1604 	int i, len, nterm;
1605 
1606 	if (old)
1607 		len = namelen + 1;
1608 	else
1609 		len = MCLBYTES;
1610 
1611 	/* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1612 	MGET(m, M_DONTWAIT, MT_DATA);
1613 	if (m && len > MLEN) {
1614 		MCLGET(m, M_DONTWAIT);
1615 		if ((m->m_flags & M_EXT) == 0)
1616 			goto fail;
1617 	}
1618 	if (!m)
1619 		goto fail;
1620 	m->m_next = NULL;
1621 
1622 	if (old) {
1623 		m->m_len = len;
1624 		*mtod(m, char *) = namelen;
1625 		bcopy(name, mtod(m, char *) + 1, namelen);
1626 		return m;
1627 	} else {
1628 		m->m_len = 0;
1629 		cp = mtod(m, char *);
1630 		ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1631 
1632 		/* if not certain about my name, return empty buffer */
1633 		if (namelen == 0)
1634 			return m;
1635 
1636 		/*
1637 		 * guess if it looks like shortened hostname, or FQDN.
1638 		 * shortened hostname needs two trailing "\0".
1639 		 */
1640 		i = 0;
1641 		for (p = name; p < name + namelen; p++) {
1642 			if (*p && *p == '.')
1643 				i++;
1644 		}
1645 		if (i < 2)
1646 			nterm = 2;
1647 		else
1648 			nterm = 1;
1649 
1650 		p = name;
1651 		while (cp < ep && p < name + namelen) {
1652 			i = 0;
1653 			for (q = p; q < name + namelen && *q && *q != '.'; q++)
1654 				i++;
1655 			/* result does not fit into mbuf */
1656 			if (cp + i + 1 >= ep)
1657 				goto fail;
1658 			/*
1659 			 * DNS label length restriction, RFC1035 page 8.
1660 			 * "i == 0" case is included here to avoid returning
1661 			 * 0-length label on "foo..bar".
1662 			 */
1663 			if (i <= 0 || i >= 64)
1664 				goto fail;
1665 			*cp++ = i;
1666 			bcopy(p, cp, i);
1667 			cp += i;
1668 			p = q;
1669 			if (p < name + namelen && *p == '.')
1670 				p++;
1671 		}
1672 		/* termination */
1673 		if (cp + nterm >= ep)
1674 			goto fail;
1675 		while (nterm-- > 0)
1676 			*cp++ = '\0';
1677 		m->m_len = cp - mtod(m, char *);
1678 		return m;
1679 	}
1680 
1681 	panic("should not reach here");
1682 	/* NOTREACHED */
1683 
1684  fail:
1685 	if (m)
1686 		m_freem(m);
1687 	return NULL;
1688 }
1689 
1690 /*
1691  * check if two DNS-encoded string matches.  takes care of truncated
1692  * form (with \0\0 at the end).  no compression support.
1693  * XXX upper/lowercase match (see RFC2065)
1694  */
1695 static int
1696 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1697 {
1698 	const char *a0, *b0;
1699 	int l;
1700 
1701 	/* simplest case - need validation? */
1702 	if (alen == blen && bcmp(a, b, alen) == 0)
1703 		return 1;
1704 
1705 	a0 = a;
1706 	b0 = b;
1707 
1708 	/* termination is mandatory */
1709 	if (alen < 2 || blen < 2)
1710 		return 0;
1711 	if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1712 		return 0;
1713 	alen--;
1714 	blen--;
1715 
1716 	while (a - a0 < alen && b - b0 < blen) {
1717 		if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1718 			return 0;
1719 
1720 		if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1721 			return 0;
1722 		/* we don't support compression yet */
1723 		if (a[0] >= 64 || b[0] >= 64)
1724 			return 0;
1725 
1726 		/* truncated case */
1727 		if (a[0] == 0 && a - a0 == alen - 1)
1728 			return 1;
1729 		if (b[0] == 0 && b - b0 == blen - 1)
1730 			return 1;
1731 		if (a[0] == 0 || b[0] == 0)
1732 			return 0;
1733 
1734 		if (a[0] != b[0])
1735 			return 0;
1736 		l = a[0];
1737 		if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1738 			return 0;
1739 		if (bcmp(a + 1, b + 1, l) != 0)
1740 			return 0;
1741 
1742 		a += 1 + l;
1743 		b += 1 + l;
1744 	}
1745 
1746 	if (a - a0 == alen && b - b0 == blen)
1747 		return 1;
1748 	else
1749 		return 0;
1750 }
1751 
1752 /*
1753  * calculate the number of addresses to be returned in the node info reply.
1754  */
1755 static int
1756 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1757     struct in6_addr *subj)
1758 {
1759 	struct ifnet *ifp;
1760 	struct in6_ifaddr *ifa6;
1761 	struct ifaddr *ifa;
1762 	int addrs = 0, addrsofif, iffound = 0;
1763 	int niflags = ni6->ni_flags;
1764 
1765 	if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1766 		switch (ni6->ni_code) {
1767 		case ICMP6_NI_SUBJ_IPV6:
1768 			if (subj == NULL) /* must be impossible... */
1769 				return (0);
1770 			break;
1771 		default:
1772 			/*
1773 			 * XXX: we only support IPv6 subject address for
1774 			 * this Qtype.
1775 			 */
1776 			return (0);
1777 		}
1778 	}
1779 
1780 	IFNET_RLOCK_NOSLEEP();
1781 	for (ifp = TAILQ_FIRST(&V_ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1782 		addrsofif = 0;
1783 		IF_ADDR_LOCK(ifp);
1784 		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1785 			if (ifa->ifa_addr->sa_family != AF_INET6)
1786 				continue;
1787 			ifa6 = (struct in6_ifaddr *)ifa;
1788 
1789 			if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1790 			    IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1791 				iffound = 1;
1792 
1793 			/*
1794 			 * IPv4-mapped addresses can only be returned by a
1795 			 * Node Information proxy, since they represent
1796 			 * addresses of IPv4-only nodes, which perforce do
1797 			 * not implement this protocol.
1798 			 * [icmp-name-lookups-07, Section 5.4]
1799 			 * So we don't support NI_NODEADDR_FLAG_COMPAT in
1800 			 * this function at this moment.
1801 			 */
1802 
1803 			/* What do we have to do about ::1? */
1804 			switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1805 			case IPV6_ADDR_SCOPE_LINKLOCAL:
1806 				if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1807 					continue;
1808 				break;
1809 			case IPV6_ADDR_SCOPE_SITELOCAL:
1810 				if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1811 					continue;
1812 				break;
1813 			case IPV6_ADDR_SCOPE_GLOBAL:
1814 				if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1815 					continue;
1816 				break;
1817 			default:
1818 				continue;
1819 			}
1820 
1821 			/*
1822 			 * check if anycast is okay.
1823 			 * XXX: just experimental.  not in the spec.
1824 			 */
1825 			if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1826 			    (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1827 				continue; /* we need only unicast addresses */
1828 			if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1829 			    (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1830 				continue;
1831 			}
1832 			addrsofif++; /* count the address */
1833 		}
1834 		IF_ADDR_UNLOCK(ifp);
1835 		if (iffound) {
1836 			*ifpp = ifp;
1837 			IFNET_RUNLOCK_NOSLEEP();
1838 			return (addrsofif);
1839 		}
1840 
1841 		addrs += addrsofif;
1842 	}
1843 	IFNET_RUNLOCK_NOSLEEP();
1844 
1845 	return (addrs);
1846 }
1847 
1848 static int
1849 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1850     struct ifnet *ifp0, int resid)
1851 {
1852 	struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet);
1853 	struct in6_ifaddr *ifa6;
1854 	struct ifaddr *ifa;
1855 	struct ifnet *ifp_dep = NULL;
1856 	int copied = 0, allow_deprecated = 0;
1857 	u_char *cp = (u_char *)(nni6 + 1);
1858 	int niflags = ni6->ni_flags;
1859 	u_int32_t ltime;
1860 
1861 	if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1862 		return (0);	/* needless to copy */
1863 
1864 	IFNET_RLOCK_NOSLEEP();
1865   again:
1866 
1867 	for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1868 		IF_ADDR_LOCK(ifp);
1869 		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1870 			if (ifa->ifa_addr->sa_family != AF_INET6)
1871 				continue;
1872 			ifa6 = (struct in6_ifaddr *)ifa;
1873 
1874 			if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1875 			    allow_deprecated == 0) {
1876 				/*
1877 				 * prefererred address should be put before
1878 				 * deprecated addresses.
1879 				 */
1880 
1881 				/* record the interface for later search */
1882 				if (ifp_dep == NULL)
1883 					ifp_dep = ifp;
1884 
1885 				continue;
1886 			} else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1887 			    allow_deprecated != 0)
1888 				continue; /* we now collect deprecated addrs */
1889 
1890 			/* What do we have to do about ::1? */
1891 			switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1892 			case IPV6_ADDR_SCOPE_LINKLOCAL:
1893 				if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1894 					continue;
1895 				break;
1896 			case IPV6_ADDR_SCOPE_SITELOCAL:
1897 				if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1898 					continue;
1899 				break;
1900 			case IPV6_ADDR_SCOPE_GLOBAL:
1901 				if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1902 					continue;
1903 				break;
1904 			default:
1905 				continue;
1906 			}
1907 
1908 			/*
1909 			 * check if anycast is okay.
1910 			 * XXX: just experimental.  not in the spec.
1911 			 */
1912 			if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1913 			    (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1914 				continue;
1915 			if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1916 			    (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1917 				continue;
1918 			}
1919 
1920 			/* now we can copy the address */
1921 			if (resid < sizeof(struct in6_addr) +
1922 			    sizeof(u_int32_t)) {
1923 				IF_ADDR_UNLOCK(ifp);
1924 				/*
1925 				 * We give up much more copy.
1926 				 * Set the truncate flag and return.
1927 				 */
1928 				nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1929 				IFNET_RUNLOCK_NOSLEEP();
1930 				return (copied);
1931 			}
1932 
1933 			/*
1934 			 * Set the TTL of the address.
1935 			 * The TTL value should be one of the following
1936 			 * according to the specification:
1937 			 *
1938 			 * 1. The remaining lifetime of a DHCP lease on the
1939 			 *    address, or
1940 			 * 2. The remaining Valid Lifetime of a prefix from
1941 			 *    which the address was derived through Stateless
1942 			 *    Autoconfiguration.
1943 			 *
1944 			 * Note that we currently do not support stateful
1945 			 * address configuration by DHCPv6, so the former
1946 			 * case can't happen.
1947 			 */
1948 			if (ifa6->ia6_lifetime.ia6t_expire == 0)
1949 				ltime = ND6_INFINITE_LIFETIME;
1950 			else {
1951 				if (ifa6->ia6_lifetime.ia6t_expire >
1952 				    time_second)
1953 					ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second);
1954 				else
1955 					ltime = 0;
1956 			}
1957 
1958 			bcopy(&ltime, cp, sizeof(u_int32_t));
1959 			cp += sizeof(u_int32_t);
1960 
1961 			/* copy the address itself */
1962 			bcopy(&ifa6->ia_addr.sin6_addr, cp,
1963 			    sizeof(struct in6_addr));
1964 			in6_clearscope((struct in6_addr *)cp); /* XXX */
1965 			cp += sizeof(struct in6_addr);
1966 
1967 			resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1968 			copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1969 		}
1970 		IF_ADDR_UNLOCK(ifp);
1971 		if (ifp0)	/* we need search only on the specified IF */
1972 			break;
1973 	}
1974 
1975 	if (allow_deprecated == 0 && ifp_dep != NULL) {
1976 		ifp = ifp_dep;
1977 		allow_deprecated = 1;
1978 
1979 		goto again;
1980 	}
1981 
1982 	IFNET_RUNLOCK_NOSLEEP();
1983 
1984 	return (copied);
1985 }
1986 
1987 /*
1988  * XXX almost dup'ed code with rip6_input.
1989  */
1990 static int
1991 icmp6_rip6_input(struct mbuf **mp, int off)
1992 {
1993 	struct mbuf *m = *mp;
1994 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1995 	struct inpcb *in6p;
1996 	struct inpcb *last = NULL;
1997 	struct sockaddr_in6 fromsa;
1998 	struct icmp6_hdr *icmp6;
1999 	struct mbuf *opts = NULL;
2000 
2001 #ifndef PULLDOWN_TEST
2002 	/* this is assumed to be safe. */
2003 	icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
2004 #else
2005 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
2006 	if (icmp6 == NULL) {
2007 		/* m is already reclaimed */
2008 		return (IPPROTO_DONE);
2009 	}
2010 #endif
2011 
2012 	/*
2013 	 * XXX: the address may have embedded scope zone ID, which should be
2014 	 * hidden from applications.
2015 	 */
2016 	bzero(&fromsa, sizeof(fromsa));
2017 	fromsa.sin6_family = AF_INET6;
2018 	fromsa.sin6_len = sizeof(struct sockaddr_in6);
2019 	fromsa.sin6_addr = ip6->ip6_src;
2020 	if (sa6_recoverscope(&fromsa)) {
2021 		m_freem(m);
2022 		return (IPPROTO_DONE);
2023 	}
2024 
2025 	INP_INFO_RLOCK(&V_ripcbinfo);
2026 	LIST_FOREACH(in6p, &V_ripcb, inp_list) {
2027 		if ((in6p->inp_vflag & INP_IPV6) == 0)
2028 			continue;
2029 		if (in6p->inp_ip_p != IPPROTO_ICMPV6)
2030 			continue;
2031 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
2032 		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
2033 			continue;
2034 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
2035 		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
2036 			continue;
2037 		INP_RLOCK(in6p);
2038 		if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
2039 		    in6p->in6p_icmp6filt)) {
2040 			INP_RUNLOCK(in6p);
2041 			continue;
2042 		}
2043 		if (last != NULL) {
2044 			struct	mbuf *n = NULL;
2045 
2046 			/*
2047 			 * Recent network drivers tend to allocate a single
2048 			 * mbuf cluster, rather than to make a couple of
2049 			 * mbufs without clusters.  Also, since the IPv6 code
2050 			 * path tries to avoid m_pullup(), it is highly
2051 			 * probable that we still have an mbuf cluster here
2052 			 * even though the necessary length can be stored in an
2053 			 * mbuf's internal buffer.
2054 			 * Meanwhile, the default size of the receive socket
2055 			 * buffer for raw sockets is not so large.  This means
2056 			 * the possibility of packet loss is relatively higher
2057 			 * than before.  To avoid this scenario, we copy the
2058 			 * received data to a separate mbuf that does not use
2059 			 * a cluster, if possible.
2060 			 * XXX: it is better to copy the data after stripping
2061 			 * intermediate headers.
2062 			 */
2063 			if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2064 			    m->m_len <= MHLEN) {
2065 				MGET(n, M_DONTWAIT, m->m_type);
2066 				if (n != NULL) {
2067 					if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2068 						bcopy(m->m_data, n->m_data,
2069 						      m->m_len);
2070 						n->m_len = m->m_len;
2071 					} else {
2072 						m_free(n);
2073 						n = NULL;
2074 					}
2075 				}
2076 			}
2077 			if (n != NULL ||
2078 			    (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
2079 				if (last->inp_flags & INP_CONTROLOPTS)
2080 					ip6_savecontrol(last, n, &opts);
2081 				/* strip intermediate headers */
2082 				m_adj(n, off);
2083 				SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2084 				if (sbappendaddr_locked(
2085 				    &last->inp_socket->so_rcv,
2086 				    (struct sockaddr *)&fromsa, n, opts)
2087 				    == 0) {
2088 					/* should notify about lost packet */
2089 					m_freem(n);
2090 					if (opts) {
2091 						m_freem(opts);
2092 					}
2093 					SOCKBUF_UNLOCK(
2094 					    &last->inp_socket->so_rcv);
2095 				} else
2096 					sorwakeup_locked(last->inp_socket);
2097 				opts = NULL;
2098 			}
2099 			INP_RUNLOCK(last);
2100 		}
2101 		last = in6p;
2102 	}
2103 	INP_INFO_RUNLOCK(&V_ripcbinfo);
2104 	if (last != NULL) {
2105 		if (last->inp_flags & INP_CONTROLOPTS)
2106 			ip6_savecontrol(last, m, &opts);
2107 		/* strip intermediate headers */
2108 		m_adj(m, off);
2109 
2110 		/* avoid using mbuf clusters if possible (see above) */
2111 		if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2112 		    m->m_len <= MHLEN) {
2113 			struct mbuf *n;
2114 
2115 			MGET(n, M_DONTWAIT, m->m_type);
2116 			if (n != NULL) {
2117 				if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2118 					bcopy(m->m_data, n->m_data, m->m_len);
2119 					n->m_len = m->m_len;
2120 
2121 					m_freem(m);
2122 					m = n;
2123 				} else {
2124 					m_freem(n);
2125 					n = NULL;
2126 				}
2127 			}
2128 		}
2129 		SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2130 		if (sbappendaddr_locked(&last->inp_socket->so_rcv,
2131 		    (struct sockaddr *)&fromsa, m, opts) == 0) {
2132 			m_freem(m);
2133 			if (opts)
2134 				m_freem(opts);
2135 			SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
2136 		} else
2137 			sorwakeup_locked(last->inp_socket);
2138 		INP_RUNLOCK(last);
2139 	} else {
2140 		m_freem(m);
2141 		IP6STAT_DEC(ip6s_delivered);
2142 	}
2143 	return IPPROTO_DONE;
2144 }
2145 
2146 /*
2147  * Reflect the ip6 packet back to the source.
2148  * OFF points to the icmp6 header, counted from the top of the mbuf.
2149  */
2150 void
2151 icmp6_reflect(struct mbuf *m, size_t off)
2152 {
2153 	struct ip6_hdr *ip6;
2154 	struct icmp6_hdr *icmp6;
2155 	struct in6_ifaddr *ia = NULL;
2156 	int plen;
2157 	int type, code;
2158 	struct ifnet *outif = NULL;
2159 	struct in6_addr origdst, src, *srcp = NULL;
2160 
2161 	/* too short to reflect */
2162 	if (off < sizeof(struct ip6_hdr)) {
2163 		nd6log((LOG_DEBUG,
2164 		    "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2165 		    (u_long)off, (u_long)sizeof(struct ip6_hdr),
2166 		    __FILE__, __LINE__));
2167 		goto bad;
2168 	}
2169 
2170 	/*
2171 	 * If there are extra headers between IPv6 and ICMPv6, strip
2172 	 * off that header first.
2173 	 */
2174 #ifdef DIAGNOSTIC
2175 	if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2176 		panic("assumption failed in icmp6_reflect");
2177 #endif
2178 	if (off > sizeof(struct ip6_hdr)) {
2179 		size_t l;
2180 		struct ip6_hdr nip6;
2181 
2182 		l = off - sizeof(struct ip6_hdr);
2183 		m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2184 		m_adj(m, l);
2185 		l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2186 		if (m->m_len < l) {
2187 			if ((m = m_pullup(m, l)) == NULL)
2188 				return;
2189 		}
2190 		bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2191 	} else /* off == sizeof(struct ip6_hdr) */ {
2192 		size_t l;
2193 		l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2194 		if (m->m_len < l) {
2195 			if ((m = m_pullup(m, l)) == NULL)
2196 				return;
2197 		}
2198 	}
2199 	plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2200 	ip6 = mtod(m, struct ip6_hdr *);
2201 	ip6->ip6_nxt = IPPROTO_ICMPV6;
2202 	icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2203 	type = icmp6->icmp6_type; /* keep type for statistics */
2204 	code = icmp6->icmp6_code; /* ditto. */
2205 
2206 	origdst = ip6->ip6_dst;
2207 	/*
2208 	 * ip6_input() drops a packet if its src is multicast.
2209 	 * So, the src is never multicast.
2210 	 */
2211 	ip6->ip6_dst = ip6->ip6_src;
2212 
2213 	/*
2214 	 * If the incoming packet was addressed directly to us (i.e. unicast),
2215 	 * use dst as the src for the reply.
2216 	 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2217 	 * (for example) when we encounter an error while forwarding procedure
2218 	 * destined to a duplicated address of ours.
2219 	 * Note that ip6_getdstifaddr() may fail if we are in an error handling
2220 	 * procedure of an outgoing packet of our own, in which case we need
2221 	 * to search in the ifaddr list.
2222 	 */
2223 	if (!IN6_IS_ADDR_MULTICAST(&origdst)) {
2224 		if ((ia = ip6_getdstifaddr(m))) {
2225 			if (!(ia->ia6_flags &
2226 			    (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)))
2227 				srcp = &ia->ia_addr.sin6_addr;
2228 		} else {
2229 			struct sockaddr_in6 d;
2230 
2231 			bzero(&d, sizeof(d));
2232 			d.sin6_family = AF_INET6;
2233 			d.sin6_len = sizeof(d);
2234 			d.sin6_addr = origdst;
2235 			ia = (struct in6_ifaddr *)
2236 			    ifa_ifwithaddr((struct sockaddr *)&d);
2237 			if (ia &&
2238 			    !(ia->ia6_flags &
2239 			    (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2240 				srcp = &ia->ia_addr.sin6_addr;
2241 			}
2242 		}
2243 	}
2244 
2245 	if ((srcp != NULL) &&
2246 	    (in6_addrscope(srcp) != in6_addrscope(&ip6->ip6_src)))
2247 		srcp = NULL;
2248 
2249 	if (srcp == NULL) {
2250 		int e;
2251 		struct sockaddr_in6 sin6;
2252 		struct route_in6 ro;
2253 
2254 		/*
2255 		 * This case matches to multicasts, our anycast, or unicasts
2256 		 * that we do not own.  Select a source address based on the
2257 		 * source address of the erroneous packet.
2258 		 */
2259 		bzero(&sin6, sizeof(sin6));
2260 		sin6.sin6_family = AF_INET6;
2261 		sin6.sin6_len = sizeof(sin6);
2262 		sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */
2263 
2264 		bzero(&ro, sizeof(ro));
2265 		e = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &src);
2266 		if (ro.ro_rt)
2267 			RTFREE(ro.ro_rt); /* XXX: we could use this */
2268 		if (e) {
2269 			char ip6buf[INET6_ADDRSTRLEN];
2270 			nd6log((LOG_DEBUG,
2271 			    "icmp6_reflect: source can't be determined: "
2272 			    "dst=%s, error=%d\n",
2273 			    ip6_sprintf(ip6buf, &sin6.sin6_addr), e));
2274 			goto bad;
2275 		}
2276 		srcp = &src;
2277 	}
2278 
2279 	ip6->ip6_src = *srcp;
2280 	ip6->ip6_flow = 0;
2281 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2282 	ip6->ip6_vfc |= IPV6_VERSION;
2283 	ip6->ip6_nxt = IPPROTO_ICMPV6;
2284 	if (outif)
2285 		ip6->ip6_hlim = ND_IFINFO(outif)->chlim;
2286 	else if (m->m_pkthdr.rcvif) {
2287 		/* XXX: This may not be the outgoing interface */
2288 		ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2289 	} else
2290 		ip6->ip6_hlim = V_ip6_defhlim;
2291 
2292 	icmp6->icmp6_cksum = 0;
2293 	icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2294 	    sizeof(struct ip6_hdr), plen);
2295 
2296 	/*
2297 	 * XXX option handling
2298 	 */
2299 
2300 	m->m_flags &= ~(M_BCAST|M_MCAST);
2301 
2302 	ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2303 	if (outif)
2304 		icmp6_ifoutstat_inc(outif, type, code);
2305 
2306 	if (ia != NULL)
2307 		ifa_free(&ia->ia_ifa);
2308 	return;
2309 
2310  bad:
2311 	if (ia != NULL)
2312 		ifa_free(&ia->ia_ifa);
2313 	m_freem(m);
2314 	return;
2315 }
2316 
2317 void
2318 icmp6_fasttimo(void)
2319 {
2320 
2321 	mld_fasttimo();
2322 }
2323 
2324 void
2325 icmp6_slowtimo(void)
2326 {
2327 
2328 	mld_slowtimo();
2329 }
2330 
2331 static const char *
2332 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2333     struct in6_addr *tgt6)
2334 {
2335 	static char buf[1024];
2336 	char ip6bufs[INET6_ADDRSTRLEN];
2337 	char ip6bufd[INET6_ADDRSTRLEN];
2338 	char ip6buft[INET6_ADDRSTRLEN];
2339 	snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2340 	    ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2341 	    ip6_sprintf(ip6buft, tgt6));
2342 	return buf;
2343 }
2344 
2345 void
2346 icmp6_redirect_input(struct mbuf *m, int off)
2347 {
2348 	struct ifnet *ifp;
2349 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2350 	struct nd_redirect *nd_rd;
2351 	int icmp6len = ntohs(ip6->ip6_plen);
2352 	char *lladdr = NULL;
2353 	int lladdrlen = 0;
2354 	u_char *redirhdr = NULL;
2355 	int redirhdrlen = 0;
2356 	struct rtentry *rt = NULL;
2357 	int is_router;
2358 	int is_onlink;
2359 	struct in6_addr src6 = ip6->ip6_src;
2360 	struct in6_addr redtgt6;
2361 	struct in6_addr reddst6;
2362 	union nd_opts ndopts;
2363 	char ip6buf[INET6_ADDRSTRLEN];
2364 
2365 	if (!m)
2366 		return;
2367 
2368 	ifp = m->m_pkthdr.rcvif;
2369 
2370 	if (!ifp)
2371 		return;
2372 
2373 	/* XXX if we are router, we don't update route by icmp6 redirect */
2374 	if (V_ip6_forwarding)
2375 		goto freeit;
2376 	if (!V_icmp6_rediraccept)
2377 		goto freeit;
2378 
2379 #ifndef PULLDOWN_TEST
2380 	IP6_EXTHDR_CHECK(m, off, icmp6len,);
2381 	nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2382 #else
2383 	IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2384 	if (nd_rd == NULL) {
2385 		ICMP6STAT_INC(icp6s_tooshort);
2386 		return;
2387 	}
2388 #endif
2389 	redtgt6 = nd_rd->nd_rd_target;
2390 	reddst6 = nd_rd->nd_rd_dst;
2391 
2392 	if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2393 	    in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2394 		goto freeit;
2395 	}
2396 
2397 	/* validation */
2398 	if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2399 		nd6log((LOG_ERR,
2400 		    "ICMP6 redirect sent from %s rejected; "
2401 		    "must be from linklocal\n",
2402 		    ip6_sprintf(ip6buf, &src6)));
2403 		goto bad;
2404 	}
2405 	if (ip6->ip6_hlim != 255) {
2406 		nd6log((LOG_ERR,
2407 		    "ICMP6 redirect sent from %s rejected; "
2408 		    "hlim=%d (must be 255)\n",
2409 		    ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2410 		goto bad;
2411 	}
2412     {
2413 	/* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2414 	struct sockaddr_in6 sin6;
2415 	struct in6_addr *gw6;
2416 
2417 	bzero(&sin6, sizeof(sin6));
2418 	sin6.sin6_family = AF_INET6;
2419 	sin6.sin6_len = sizeof(struct sockaddr_in6);
2420 	bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
2421 	rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
2422 	if (rt) {
2423 		if (rt->rt_gateway == NULL ||
2424 		    rt->rt_gateway->sa_family != AF_INET6) {
2425 			nd6log((LOG_ERR,
2426 			    "ICMP6 redirect rejected; no route "
2427 			    "with inet6 gateway found for redirect dst: %s\n",
2428 			    icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2429 			RTFREE_LOCKED(rt);
2430 			goto bad;
2431 		}
2432 
2433 		gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2434 		if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2435 			nd6log((LOG_ERR,
2436 			    "ICMP6 redirect rejected; "
2437 			    "not equal to gw-for-src=%s (must be same): "
2438 			    "%s\n",
2439 			    ip6_sprintf(ip6buf, gw6),
2440 			    icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2441 			RTFREE_LOCKED(rt);
2442 			goto bad;
2443 		}
2444 	} else {
2445 		nd6log((LOG_ERR,
2446 		    "ICMP6 redirect rejected; "
2447 		    "no route found for redirect dst: %s\n",
2448 		    icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2449 		goto bad;
2450 	}
2451 	RTFREE_LOCKED(rt);
2452 	rt = NULL;
2453     }
2454 	if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2455 		nd6log((LOG_ERR,
2456 		    "ICMP6 redirect rejected; "
2457 		    "redirect dst must be unicast: %s\n",
2458 		    icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2459 		goto bad;
2460 	}
2461 
2462 	is_router = is_onlink = 0;
2463 	if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2464 		is_router = 1;	/* router case */
2465 	if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2466 		is_onlink = 1;	/* on-link destination case */
2467 	if (!is_router && !is_onlink) {
2468 		nd6log((LOG_ERR,
2469 		    "ICMP6 redirect rejected; "
2470 		    "neither router case nor onlink case: %s\n",
2471 		    icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2472 		goto bad;
2473 	}
2474 	/* validation passed */
2475 
2476 	icmp6len -= sizeof(*nd_rd);
2477 	nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2478 	if (nd6_options(&ndopts) < 0) {
2479 		nd6log((LOG_INFO, "icmp6_redirect_input: "
2480 		    "invalid ND option, rejected: %s\n",
2481 		    icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2482 		/* nd6_options have incremented stats */
2483 		goto freeit;
2484 	}
2485 
2486 	if (ndopts.nd_opts_tgt_lladdr) {
2487 		lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2488 		lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2489 	}
2490 
2491 	if (ndopts.nd_opts_rh) {
2492 		redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
2493 		redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
2494 	}
2495 
2496 	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2497 		nd6log((LOG_INFO,
2498 		    "icmp6_redirect_input: lladdrlen mismatch for %s "
2499 		    "(if %d, icmp6 packet %d): %s\n",
2500 		    ip6_sprintf(ip6buf, &redtgt6),
2501 		    ifp->if_addrlen, lladdrlen - 2,
2502 		    icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2503 		goto bad;
2504 	}
2505 
2506 	/* RFC 2461 8.3 */
2507 	nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2508 	    is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2509 
2510 	if (!is_onlink) {	/* better router case.  perform rtredirect. */
2511 		/* perform rtredirect */
2512 		struct sockaddr_in6 sdst;
2513 		struct sockaddr_in6 sgw;
2514 		struct sockaddr_in6 ssrc;
2515 
2516 		bzero(&sdst, sizeof(sdst));
2517 		bzero(&sgw, sizeof(sgw));
2518 		bzero(&ssrc, sizeof(ssrc));
2519 		sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2520 		sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2521 			sizeof(struct sockaddr_in6);
2522 		bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2523 		bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2524 		bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2525 		rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2526 		    (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
2527 		    (struct sockaddr *)&ssrc);
2528 	}
2529 	/* finally update cached route in each socket via pfctlinput */
2530     {
2531 	struct sockaddr_in6 sdst;
2532 
2533 	bzero(&sdst, sizeof(sdst));
2534 	sdst.sin6_family = AF_INET6;
2535 	sdst.sin6_len = sizeof(struct sockaddr_in6);
2536 	bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2537 	pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2538 #ifdef IPSEC
2539 	key_sa_routechange((struct sockaddr *)&sdst);
2540 #endif /* IPSEC */
2541     }
2542 
2543  freeit:
2544 	m_freem(m);
2545 	return;
2546 
2547  bad:
2548 	ICMP6STAT_INC(icp6s_badredirect);
2549 	m_freem(m);
2550 }
2551 
2552 void
2553 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2554 {
2555 	struct ifnet *ifp;	/* my outgoing interface */
2556 	struct in6_addr *ifp_ll6;
2557 	struct in6_addr *router_ll6;
2558 	struct ip6_hdr *sip6;	/* m0 as struct ip6_hdr */
2559 	struct mbuf *m = NULL;	/* newly allocated one */
2560 	struct m_tag *mtag;
2561 	struct ip6_hdr *ip6;	/* m as struct ip6_hdr */
2562 	struct nd_redirect *nd_rd;
2563 	struct llentry *ln = NULL;
2564 	size_t maxlen;
2565 	u_char *p;
2566 	struct ifnet *outif = NULL;
2567 	struct sockaddr_in6 src_sa;
2568 
2569 	icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
2570 
2571 	/* if we are not router, we don't send icmp6 redirect */
2572 	if (!V_ip6_forwarding)
2573 		goto fail;
2574 
2575 	/* sanity check */
2576 	if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2577 		goto fail;
2578 
2579 	/*
2580 	 * Address check:
2581 	 *  the source address must identify a neighbor, and
2582 	 *  the destination address must not be a multicast address
2583 	 *  [RFC 2461, sec 8.2]
2584 	 */
2585 	sip6 = mtod(m0, struct ip6_hdr *);
2586 	bzero(&src_sa, sizeof(src_sa));
2587 	src_sa.sin6_family = AF_INET6;
2588 	src_sa.sin6_len = sizeof(src_sa);
2589 	src_sa.sin6_addr = sip6->ip6_src;
2590 	if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2591 		goto fail;
2592 	if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2593 		goto fail;	/* what should we do here? */
2594 
2595 	/* rate limit */
2596 	if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2597 		goto fail;
2598 
2599 	/*
2600 	 * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2601 	 * we almost always ask for an mbuf cluster for simplicity.
2602 	 * (MHLEN < IPV6_MMTU is almost always true)
2603 	 */
2604 #if IPV6_MMTU >= MCLBYTES
2605 # error assumption failed about IPV6_MMTU and MCLBYTES
2606 #endif
2607 	MGETHDR(m, M_DONTWAIT, MT_HEADER);
2608 	if (m && IPV6_MMTU >= MHLEN)
2609 		MCLGET(m, M_DONTWAIT);
2610 	if (!m)
2611 		goto fail;
2612 	m->m_pkthdr.rcvif = NULL;
2613 	m->m_len = 0;
2614 	maxlen = M_TRAILINGSPACE(m);
2615 	maxlen = min(IPV6_MMTU, maxlen);
2616 	/* just for safety */
2617 	if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2618 	    ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2619 		goto fail;
2620 	}
2621 
2622 	{
2623 		/* get ip6 linklocal address for ifp(my outgoing interface). */
2624 		struct in6_ifaddr *ia;
2625 		if ((ia = in6ifa_ifpforlinklocal(ifp,
2626 						 IN6_IFF_NOTREADY|
2627 						 IN6_IFF_ANYCAST)) == NULL)
2628 			goto fail;
2629 		ifp_ll6 = &ia->ia_addr.sin6_addr;
2630 		/* XXXRW: reference released prematurely. */
2631 		ifa_free(&ia->ia_ifa);
2632 	}
2633 
2634 	/* get ip6 linklocal address for the router. */
2635 	if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2636 		struct sockaddr_in6 *sin6;
2637 		sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2638 		router_ll6 = &sin6->sin6_addr;
2639 		if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2640 			router_ll6 = (struct in6_addr *)NULL;
2641 	} else
2642 		router_ll6 = (struct in6_addr *)NULL;
2643 
2644 	/* ip6 */
2645 	ip6 = mtod(m, struct ip6_hdr *);
2646 	ip6->ip6_flow = 0;
2647 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2648 	ip6->ip6_vfc |= IPV6_VERSION;
2649 	/* ip6->ip6_plen will be set later */
2650 	ip6->ip6_nxt = IPPROTO_ICMPV6;
2651 	ip6->ip6_hlim = 255;
2652 	/* ip6->ip6_src must be linklocal addr for my outgoing if. */
2653 	bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2654 	bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2655 
2656 	/* ND Redirect */
2657 	nd_rd = (struct nd_redirect *)(ip6 + 1);
2658 	nd_rd->nd_rd_type = ND_REDIRECT;
2659 	nd_rd->nd_rd_code = 0;
2660 	nd_rd->nd_rd_reserved = 0;
2661 	if (rt->rt_flags & RTF_GATEWAY) {
2662 		/*
2663 		 * nd_rd->nd_rd_target must be a link-local address in
2664 		 * better router cases.
2665 		 */
2666 		if (!router_ll6)
2667 			goto fail;
2668 		bcopy(router_ll6, &nd_rd->nd_rd_target,
2669 		    sizeof(nd_rd->nd_rd_target));
2670 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2671 		    sizeof(nd_rd->nd_rd_dst));
2672 	} else {
2673 		/* make sure redtgt == reddst */
2674 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2675 		    sizeof(nd_rd->nd_rd_target));
2676 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2677 		    sizeof(nd_rd->nd_rd_dst));
2678 	}
2679 
2680 	p = (u_char *)(nd_rd + 1);
2681 
2682 	if (!router_ll6)
2683 		goto nolladdropt;
2684 
2685 	{
2686 		/* target lladdr option */
2687 		int len;
2688 		struct nd_opt_hdr *nd_opt;
2689 		char *lladdr;
2690 
2691 		IF_AFDATA_LOCK(ifp);
2692 		ln = nd6_lookup(router_ll6, 0, ifp);
2693 		IF_AFDATA_UNLOCK(ifp);
2694 		if (ln == NULL)
2695 			goto nolladdropt;
2696 
2697 		len = sizeof(*nd_opt) + ifp->if_addrlen;
2698 		len = (len + 7) & ~7;	/* round by 8 */
2699 		/* safety check */
2700 		if (len + (p - (u_char *)ip6) > maxlen)
2701 			goto nolladdropt;
2702 
2703 		if (ln->la_flags & LLE_VALID) {
2704 			nd_opt = (struct nd_opt_hdr *)p;
2705 			nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2706 			nd_opt->nd_opt_len = len >> 3;
2707 			lladdr = (char *)(nd_opt + 1);
2708 			bcopy(&ln->ll_addr, lladdr, ifp->if_addrlen);
2709 			p += len;
2710 		}
2711 	}
2712 nolladdropt:
2713 	if (ln != NULL)
2714 		LLE_RUNLOCK(ln);
2715 
2716 	m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2717 
2718 	/* just to be safe */
2719 #ifdef M_DECRYPTED	/*not openbsd*/
2720 	if (m0->m_flags & M_DECRYPTED)
2721 		goto noredhdropt;
2722 #endif
2723 	if (p - (u_char *)ip6 > maxlen)
2724 		goto noredhdropt;
2725 
2726 	{
2727 		/* redirected header option */
2728 		int len;
2729 		struct nd_opt_rd_hdr *nd_opt_rh;
2730 
2731 		/*
2732 		 * compute the maximum size for icmp6 redirect header option.
2733 		 * XXX room for auth header?
2734 		 */
2735 		len = maxlen - (p - (u_char *)ip6);
2736 		len &= ~7;
2737 
2738 		/* This is just for simplicity. */
2739 		if (m0->m_pkthdr.len != m0->m_len) {
2740 			if (m0->m_next) {
2741 				m_freem(m0->m_next);
2742 				m0->m_next = NULL;
2743 			}
2744 			m0->m_pkthdr.len = m0->m_len;
2745 		}
2746 
2747 		/*
2748 		 * Redirected header option spec (RFC2461 4.6.3) talks nothing
2749 		 * about padding/truncate rule for the original IP packet.
2750 		 * From the discussion on IPv6imp in Feb 1999,
2751 		 * the consensus was:
2752 		 * - "attach as much as possible" is the goal
2753 		 * - pad if not aligned (original size can be guessed by
2754 		 *   original ip6 header)
2755 		 * Following code adds the padding if it is simple enough,
2756 		 * and truncates if not.
2757 		 */
2758 		if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2759 			panic("assumption failed in %s:%d", __FILE__,
2760 			    __LINE__);
2761 
2762 		if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2763 			/* not enough room, truncate */
2764 			m0->m_pkthdr.len = m0->m_len = len -
2765 			    sizeof(*nd_opt_rh);
2766 		} else {
2767 			/* enough room, pad or truncate */
2768 			size_t extra;
2769 
2770 			extra = m0->m_pkthdr.len % 8;
2771 			if (extra) {
2772 				/* pad if easy enough, truncate if not */
2773 				if (8 - extra <= M_TRAILINGSPACE(m0)) {
2774 					/* pad */
2775 					m0->m_len += (8 - extra);
2776 					m0->m_pkthdr.len += (8 - extra);
2777 				} else {
2778 					/* truncate */
2779 					m0->m_pkthdr.len -= extra;
2780 					m0->m_len -= extra;
2781 				}
2782 			}
2783 			len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2784 			m0->m_pkthdr.len = m0->m_len = len -
2785 			    sizeof(*nd_opt_rh);
2786 		}
2787 
2788 		nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2789 		bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2790 		nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2791 		nd_opt_rh->nd_opt_rh_len = len >> 3;
2792 		p += sizeof(*nd_opt_rh);
2793 		m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2794 
2795 		/* connect m0 to m */
2796 		m_tag_delete_chain(m0, NULL);
2797 		m0->m_flags &= ~M_PKTHDR;
2798 		m->m_next = m0;
2799 		m->m_pkthdr.len = m->m_len + m0->m_len;
2800 		m0 = NULL;
2801 	}
2802 noredhdropt:;
2803 	if (m0) {
2804 		m_freem(m0);
2805 		m0 = NULL;
2806 	}
2807 
2808 	/* XXX: clear embedded link IDs in the inner header */
2809 	in6_clearscope(&sip6->ip6_src);
2810 	in6_clearscope(&sip6->ip6_dst);
2811 	in6_clearscope(&nd_rd->nd_rd_target);
2812 	in6_clearscope(&nd_rd->nd_rd_dst);
2813 
2814 	ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2815 
2816 	nd_rd->nd_rd_cksum = 0;
2817 	nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2818 	    sizeof(*ip6), ntohs(ip6->ip6_plen));
2819 
2820         if (send_sendso_input_hook != NULL) {
2821 		mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short),
2822 			M_NOWAIT);
2823 		if (mtag == NULL)
2824 			goto fail;
2825 		*(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type;
2826 		m_tag_prepend(m, mtag);
2827 	}
2828 
2829 	/* send the packet to outside... */
2830 	ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2831 	if (outif) {
2832 		icmp6_ifstat_inc(outif, ifs6_out_msg);
2833 		icmp6_ifstat_inc(outif, ifs6_out_redirect);
2834 	}
2835 	ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
2836 
2837 	return;
2838 
2839 fail:
2840 	if (m)
2841 		m_freem(m);
2842 	if (m0)
2843 		m_freem(m0);
2844 }
2845 
2846 /*
2847  * ICMPv6 socket option processing.
2848  */
2849 int
2850 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2851 {
2852 	int error = 0;
2853 	int optlen;
2854 	struct inpcb *inp = sotoinpcb(so);
2855 	int level, op, optname;
2856 
2857 	if (sopt) {
2858 		level = sopt->sopt_level;
2859 		op = sopt->sopt_dir;
2860 		optname = sopt->sopt_name;
2861 		optlen = sopt->sopt_valsize;
2862 	} else
2863 		level = op = optname = optlen = 0;
2864 
2865 	if (level != IPPROTO_ICMPV6) {
2866 		return EINVAL;
2867 	}
2868 
2869 	switch (op) {
2870 	case PRCO_SETOPT:
2871 		switch (optname) {
2872 		case ICMP6_FILTER:
2873 		    {
2874 			struct icmp6_filter ic6f;
2875 
2876 			if (optlen != sizeof(ic6f)) {
2877 				error = EMSGSIZE;
2878 				break;
2879 			}
2880 			error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2881 			if (error == 0) {
2882 				INP_WLOCK(inp);
2883 				*inp->in6p_icmp6filt = ic6f;
2884 				INP_WUNLOCK(inp);
2885 			}
2886 			break;
2887 		    }
2888 
2889 		default:
2890 			error = ENOPROTOOPT;
2891 			break;
2892 		}
2893 		break;
2894 
2895 	case PRCO_GETOPT:
2896 		switch (optname) {
2897 		case ICMP6_FILTER:
2898 		    {
2899 			struct icmp6_filter ic6f;
2900 
2901 			INP_RLOCK(inp);
2902 			ic6f = *inp->in6p_icmp6filt;
2903 			INP_RUNLOCK(inp);
2904 			error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2905 			break;
2906 		    }
2907 
2908 		default:
2909 			error = ENOPROTOOPT;
2910 			break;
2911 		}
2912 		break;
2913 	}
2914 
2915 	return (error);
2916 }
2917 
2918 /*
2919  * Perform rate limit check.
2920  * Returns 0 if it is okay to send the icmp6 packet.
2921  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2922  * limitation.
2923  *
2924  * XXX per-destination/type check necessary?
2925  *
2926  * dst - not used at this moment
2927  * type - not used at this moment
2928  * code - not used at this moment
2929  */
2930 static int
2931 icmp6_ratelimit(const struct in6_addr *dst, const int type,
2932     const int code)
2933 {
2934 	int ret;
2935 
2936 	ret = 0;	/* okay to send */
2937 
2938 	/* PPS limit */
2939 	if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
2940 	    V_icmp6errppslim)) {
2941 		/* The packet is subject to rate limit */
2942 		ret++;
2943 	}
2944 
2945 	return ret;
2946 }
2947