xref: /netbsd-src/sys/netinet6/icmp6.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: icmp6.c,v 1.155 2009/10/18 22:57:05 christos Exp $	*/
2 /*	$KAME: icmp6.c,v 1.217 2001/06/20 15:03:29 jinmei 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  * 3. 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 <sys/cdefs.h>
65 __KERNEL_RCSID(0, "$NetBSD: icmp6.c,v 1.155 2009/10/18 22:57:05 christos Exp $");
66 
67 #include "opt_inet.h"
68 #include "opt_ipsec.h"
69 
70 #include <sys/param.h>
71 #include <sys/systm.h>
72 #include <sys/malloc.h>
73 #include <sys/mbuf.h>
74 #include <sys/protosw.h>
75 #include <sys/socket.h>
76 #include <sys/socketvar.h>
77 #include <sys/time.h>
78 #include <sys/kernel.h>
79 #include <sys/syslog.h>
80 #include <sys/domain.h>
81 #include <sys/sysctl.h>
82 
83 #include <net/if.h>
84 #include <net/route.h>
85 #include <net/if_dl.h>
86 #include <net/if_types.h>
87 
88 #include <netinet/in.h>
89 #include <netinet/in_var.h>
90 #include <netinet/ip6.h>
91 #include <netinet6/ip6_var.h>
92 #include <netinet6/ip6_private.h>
93 #include <netinet/icmp6.h>
94 #include <netinet6/icmp6_private.h>
95 #include <netinet6/mld6_var.h>
96 #include <netinet6/in6_pcb.h>
97 #include <netinet6/nd6.h>
98 #include <netinet6/in6_ifattach.h>
99 #include <netinet6/ip6protosw.h>
100 #include <netinet6/scope6_var.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 
113 #include "faith.h"
114 #if defined(NFAITH) && 0 < NFAITH
115 #include <net/if_faith.h>
116 #endif
117 
118 #include <net/net_osdep.h>
119 
120 extern struct domain inet6domain;
121 
122 percpu_t *icmp6stat_percpu;
123 
124 extern struct inpcbtable raw6cbtable;
125 extern int icmp6errppslim;
126 static int icmp6errpps_count = 0;
127 static struct timeval icmp6errppslim_last;
128 extern int icmp6_nodeinfo;
129 
130 /*
131  * List of callbacks to notify when Path MTU changes are made.
132  */
133 struct icmp6_mtudisc_callback {
134 	LIST_ENTRY(icmp6_mtudisc_callback) mc_list;
135 	void (*mc_func)(struct in6_addr *);
136 };
137 
138 LIST_HEAD(, icmp6_mtudisc_callback) icmp6_mtudisc_callbacks =
139     LIST_HEAD_INITIALIZER(&icmp6_mtudisc_callbacks);
140 
141 static struct rttimer_queue *icmp6_mtudisc_timeout_q = NULL;
142 extern int pmtu_expire;
143 
144 /* XXX do these values make any sense? */
145 static int icmp6_mtudisc_hiwat = 1280;
146 static int icmp6_mtudisc_lowat = 256;
147 
148 /*
149  * keep track of # of redirect routes.
150  */
151 static struct rttimer_queue *icmp6_redirect_timeout_q = NULL;
152 
153 /* XXX experimental, turned off */
154 static int icmp6_redirect_hiwat = -1;
155 static int icmp6_redirect_lowat = -1;
156 
157 static void icmp6_errcount(u_int, int, int);
158 static int icmp6_rip6_input(struct mbuf **, int);
159 static int icmp6_ratelimit(const struct in6_addr *, const int, const int);
160 static const char *icmp6_redirect_diag(struct in6_addr *,
161 	struct in6_addr *, struct in6_addr *);
162 static struct mbuf *ni6_input(struct mbuf *, int);
163 static struct mbuf *ni6_nametodns(const char *, int, int);
164 static int ni6_dnsmatch(const char *, int, const char *, int);
165 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *,
166 			  struct ifnet **, char *);
167 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
168 				struct ifnet *, int);
169 static int icmp6_notify_error(struct mbuf *, int, int, int);
170 static struct rtentry *icmp6_mtudisc_clone(struct sockaddr *);
171 static void icmp6_mtudisc_timeout(struct rtentry *, struct rttimer *);
172 static void icmp6_redirect_timeout(struct rtentry *, struct rttimer *);
173 static void sysctl_net_inet6_icmp6_setup(struct sysctllog **);
174 
175 
176 void
177 icmp6_init(void)
178 {
179 
180 	sysctl_net_inet6_icmp6_setup(NULL);
181 	mld_init();
182 	icmp6_mtudisc_timeout_q = rt_timer_queue_create(pmtu_expire);
183 	icmp6_redirect_timeout_q = rt_timer_queue_create(icmp6_redirtimeout);
184 
185 	icmp6stat_percpu = percpu_alloc(sizeof(uint64_t) * ICMP6_NSTATS);
186 }
187 
188 static void
189 icmp6_errcount(u_int base, int type, int code)
190 {
191 	switch (type) {
192 	case ICMP6_DST_UNREACH:
193 		switch (code) {
194 		case ICMP6_DST_UNREACH_NOROUTE:
195 			ICMP6_STATINC(base + ICMP6_ERRSTAT_DST_UNREACH_NOROUTE);
196 			return;
197 		case ICMP6_DST_UNREACH_ADMIN:
198 			ICMP6_STATINC(base + ICMP6_ERRSTAT_DST_UNREACH_ADMIN);
199 			return;
200 		case ICMP6_DST_UNREACH_BEYONDSCOPE:
201 			ICMP6_STATINC(base +
202 				      ICMP6_ERRSTAT_DST_UNREACH_BEYONDSCOPE);
203 			return;
204 		case ICMP6_DST_UNREACH_ADDR:
205 			ICMP6_STATINC(base + ICMP6_ERRSTAT_DST_UNREACH_ADDR);
206 			return;
207 		case ICMP6_DST_UNREACH_NOPORT:
208 			ICMP6_STATINC(base + ICMP6_ERRSTAT_DST_UNREACH_NOPORT);
209 			return;
210 		}
211 		break;
212 	case ICMP6_PACKET_TOO_BIG:
213 		ICMP6_STATINC(base + ICMP6_ERRSTAT_PACKET_TOO_BIG);
214 		return;
215 	case ICMP6_TIME_EXCEEDED:
216 		switch (code) {
217 		case ICMP6_TIME_EXCEED_TRANSIT:
218 			ICMP6_STATINC(base + ICMP6_ERRSTAT_TIME_EXCEED_TRANSIT);
219 			return;
220 		case ICMP6_TIME_EXCEED_REASSEMBLY:
221 			ICMP6_STATINC(base +
222 				      ICMP6_ERRSTAT_TIME_EXCEED_REASSEMBLY);
223 			return;
224 		}
225 		break;
226 	case ICMP6_PARAM_PROB:
227 		switch (code) {
228 		case ICMP6_PARAMPROB_HEADER:
229 			ICMP6_STATINC(base + ICMP6_ERRSTAT_PARAMPROB_HEADER);
230 			return;
231 		case ICMP6_PARAMPROB_NEXTHEADER:
232 			ICMP6_STATINC(base +
233 				      ICMP6_ERRSTAT_PARAMPROB_NEXTHEADER);
234 			return;
235 		case ICMP6_PARAMPROB_OPTION:
236 			ICMP6_STATINC(base + ICMP6_ERRSTAT_PARAMPROB_OPTION);
237 			return;
238 		}
239 		break;
240 	case ND_REDIRECT:
241 		ICMP6_STATINC(base + ICMP6_ERRSTAT_REDIRECT);
242 		return;
243 	}
244 	ICMP6_STATINC(base + ICMP6_ERRSTAT_UNKNOWN);
245 }
246 
247 /*
248  * Register a Path MTU Discovery callback.
249  */
250 void
251 icmp6_mtudisc_callback_register(void (*func)(struct in6_addr *))
252 {
253 	struct icmp6_mtudisc_callback *mc;
254 
255 	for (mc = LIST_FIRST(&icmp6_mtudisc_callbacks); mc != NULL;
256 	     mc = LIST_NEXT(mc, mc_list)) {
257 		if (mc->mc_func == func)
258 			return;
259 	}
260 
261 	mc = malloc(sizeof(*mc), M_PCB, M_NOWAIT);
262 	if (mc == NULL)
263 		panic("icmp6_mtudisc_callback_register");
264 
265 	mc->mc_func = func;
266 	LIST_INSERT_HEAD(&icmp6_mtudisc_callbacks, mc, mc_list);
267 }
268 
269 /*
270  * A wrapper function for icmp6_error() necessary when the erroneous packet
271  * may not contain enough scope zone information.
272  */
273 void
274 icmp6_error2(struct mbuf *m, int type, int code, int param,
275 	struct ifnet *ifp)
276 {
277 	struct ip6_hdr *ip6;
278 
279 	if (ifp == NULL)
280 		return;
281 
282 	if (m->m_len < sizeof(struct ip6_hdr)) {
283 		m = m_pullup(m, sizeof(struct ip6_hdr));
284 		if (m == NULL)
285 			return;
286 	}
287 
288 	ip6 = mtod(m, struct ip6_hdr *);
289 
290 	if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
291 		return;
292 	if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
293 		return;
294 
295 	icmp6_error(m, type, code, param);
296 }
297 
298 /*
299  * Generate an error packet of type error in response to bad IP6 packet.
300  */
301 void
302 icmp6_error(struct mbuf *m, int type, int code, int param)
303 {
304 	struct ip6_hdr *oip6, *nip6;
305 	struct icmp6_hdr *icmp6;
306 	u_int preplen;
307 	int off;
308 	int nxt;
309 
310 	ICMP6_STATINC(ICMP6_STAT_ERROR);
311 
312 	/* count per-type-code statistics */
313 	icmp6_errcount(ICMP6_STAT_OUTERRHIST, type, code);
314 
315 	if (m->m_flags & M_DECRYPTED) {
316 		ICMP6_STATINC(ICMP6_STAT_CANTERROR);
317 		goto freeit;
318 	}
319 
320 	if (M_UNWRITABLE(m, sizeof(struct ip6_hdr)) &&
321 	    (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL)
322 		return;
323 	oip6 = mtod(m, struct ip6_hdr *);
324 
325 	/*
326 	 * If the destination address of the erroneous packet is a multicast
327 	 * address, or the packet was sent using link-layer multicast,
328 	 * we should basically suppress sending an error (RFC 2463, Section
329 	 * 2.4).
330 	 * We have two exceptions (the item e.2 in that section):
331 	 * - the Pakcet Too Big message can be sent for path MTU discovery.
332 	 * - the Parameter Problem Message that can be allowed an icmp6 error
333 	 *   in the option type field.  This check has been done in
334 	 *   ip6_unknown_opt(), so we can just check the type and code.
335 	 */
336 	if ((m->m_flags & (M_BCAST|M_MCAST) ||
337 	     IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
338 	    (type != ICMP6_PACKET_TOO_BIG &&
339 	     (type != ICMP6_PARAM_PROB ||
340 	      code != ICMP6_PARAMPROB_OPTION)))
341 		goto freeit;
342 
343 	/*
344 	 * RFC 2463, 2.4 (e.5): source address check.
345 	 * XXX: the case of anycast source?
346 	 */
347 	if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
348 	    IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
349 		goto freeit;
350 
351 	/*
352 	 * If we are about to send ICMPv6 against ICMPv6 error/redirect,
353 	 * don't do it.
354 	 */
355 	nxt = -1;
356 	off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
357 	if (off >= 0 && nxt == IPPROTO_ICMPV6) {
358 		struct icmp6_hdr *icp;
359 
360 		IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
361 			sizeof(*icp));
362 		if (icp == NULL) {
363 			ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
364 			return;
365 		}
366 		if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
367 		    icp->icmp6_type == ND_REDIRECT) {
368 			/*
369 			 * ICMPv6 error
370 			 * Special case: for redirect (which is
371 			 * informational) we must not send icmp6 error.
372 			 */
373 			ICMP6_STATINC(ICMP6_STAT_CANTERROR);
374 			goto freeit;
375 		} else {
376 			/* ICMPv6 informational - send the error */
377 		}
378 	}
379 #if 0 /* controversial */
380 	else if (off >= 0 && nxt == IPPROTO_ESP) {
381 		/*
382 		 * It could be ICMPv6 error inside ESP.  Take a safer side,
383 		 * don't respond.
384 		 */
385 		ICMP6_STATINC(ICMP6_STAT_CANTERROR);
386 		goto freeit;
387 	}
388 #endif
389 	else {
390 		/* non-ICMPv6 - send the error */
391 	}
392 
393 	oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
394 
395 	/* Finally, do rate limitation check. */
396 	if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
397 		ICMP6_STATINC(ICMP6_STAT_TOOFREQ);
398 		goto freeit;
399 	}
400 
401 	/*
402 	 * OK, ICMP6 can be generated.
403 	 */
404 
405 	if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
406 		m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
407 
408 	preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
409 	M_PREPEND(m, preplen, M_DONTWAIT);
410 	if (m && M_UNWRITABLE(m, preplen))
411 		m = m_pullup(m, preplen);
412 	if (m == NULL) {
413 		nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
414 		return;
415 	}
416 
417 	nip6 = mtod(m, struct ip6_hdr *);
418 	nip6->ip6_src  = oip6->ip6_src;
419 	nip6->ip6_dst  = oip6->ip6_dst;
420 
421 	in6_clearscope(&oip6->ip6_src);
422 	in6_clearscope(&oip6->ip6_dst);
423 
424 	icmp6 = (struct icmp6_hdr *)(nip6 + 1);
425 	icmp6->icmp6_type = type;
426 	icmp6->icmp6_code = code;
427 	icmp6->icmp6_pptr = htonl((u_int32_t)param);
428 
429 	/*
430 	 * icmp6_reflect() is designed to be in the input path.
431 	 * icmp6_error() can be called from both input and output path,
432 	 * and if we are in output path rcvif could contain bogus value.
433 	 * clear m->m_pkthdr.rcvif for safety, we should have enough scope
434 	 * information in ip header (nip6).
435 	 */
436 	m->m_pkthdr.rcvif = NULL;
437 
438 	ICMP6_STATINC(ICMP6_STAT_OUTHIST + type);
439 	icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
440 
441 	return;
442 
443   freeit:
444 	/*
445 	 * If we can't tell whether or not we can generate ICMP6, free it.
446 	 */
447 	m_freem(m);
448 }
449 
450 /*
451  * Process a received ICMP6 message.
452  */
453 int
454 icmp6_input(struct mbuf **mp, int *offp, int proto)
455 {
456 	struct mbuf *m = *mp, *n;
457 	struct ip6_hdr *ip6, *nip6;
458 	struct icmp6_hdr *icmp6, *nicmp6;
459 	int off = *offp;
460 	int icmp6len = m->m_pkthdr.len - *offp;
461 	int code, sum, noff, i;
462 
463 #define ICMP6_MAXLEN (sizeof(*nip6) + sizeof(*nicmp6) + 4)
464 	KASSERT(ICMP6_MAXLEN < MCLBYTES);
465 	icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg);
466 
467 	/*
468 	 * Locate icmp6 structure in mbuf, and check
469 	 * that not corrupted and of at least minimum length
470 	 */
471 
472 	if (icmp6len < sizeof(struct icmp6_hdr)) {
473 		ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
474 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
475 		goto freeit;
476 	}
477 
478 	i = off + sizeof(*icmp6);
479 	if ((m->m_len < i || M_READONLY(m)) && (m = m_pullup(m, i)) == 0) {
480 		ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
481 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
482 		goto freeit;
483 	}
484 	ip6 = mtod(m, struct ip6_hdr *);
485 	/*
486 	 * calculate the checksum
487 	 */
488 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
489 	if (icmp6 == NULL) {
490 		ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
491 		/* m is invalid */
492 		/*icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);*/
493 		return IPPROTO_DONE;
494 	}
495 	KASSERT(IP6_HDR_ALIGNED_P(icmp6));
496 	code = icmp6->icmp6_code;
497 
498 	if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
499 		nd6log((LOG_ERR,
500 		    "ICMP6 checksum error(%d|%x) %s\n",
501 		    icmp6->icmp6_type, sum, ip6_sprintf(&ip6->ip6_src)));
502 		ICMP6_STATINC(ICMP6_STAT_CHECKSUM);
503 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
504 		goto freeit;
505 	}
506 
507 #if defined(NFAITH) && 0 < NFAITH
508 	if (faithprefix(&ip6->ip6_dst)) {
509 		/*
510 		 * Deliver very specific ICMP6 type only.
511 		 * This is important to deliver TOOBIG.  Otherwise PMTUD
512 		 * will not work.
513 		 */
514 		switch (icmp6->icmp6_type) {
515 		case ICMP6_DST_UNREACH:
516 		case ICMP6_PACKET_TOO_BIG:
517 		case ICMP6_TIME_EXCEEDED:
518 			break;
519 		default:
520 			goto freeit;
521 		}
522 	}
523 #endif
524 
525 	ICMP6_STATINC(ICMP6_STAT_INHIST + icmp6->icmp6_type);
526 
527 	switch (icmp6->icmp6_type) {
528 	case ICMP6_DST_UNREACH:
529 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach);
530 		switch (code) {
531 		case ICMP6_DST_UNREACH_NOROUTE:
532 			code = PRC_UNREACH_NET;
533 			break;
534 		case ICMP6_DST_UNREACH_ADMIN:
535 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib);
536 			code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
537 			break;
538 		case ICMP6_DST_UNREACH_ADDR:
539 			code = PRC_HOSTDEAD;
540 			break;
541 #ifdef COMPAT_RFC1885
542 		case ICMP6_DST_UNREACH_NOTNEIGHBOR:
543 			code = PRC_UNREACH_SRCFAIL;
544 			break;
545 #else
546 		case ICMP6_DST_UNREACH_BEYONDSCOPE:
547 			/* I mean "source address was incorrect." */
548 			code = PRC_UNREACH_NET;
549 			break;
550 #endif
551 		case ICMP6_DST_UNREACH_NOPORT:
552 			code = PRC_UNREACH_PORT;
553 			break;
554 		default:
555 			goto badcode;
556 		}
557 		goto deliver;
558 
559 	case ICMP6_PACKET_TOO_BIG:
560 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig);
561 
562 		/*
563 		 * MTU is checked in icmp6_mtudisc.
564 		 */
565 		code = PRC_MSGSIZE;
566 
567 		/*
568 		 * Updating the path MTU will be done after examining
569 		 * intermediate extension headers.
570 		 */
571 		goto deliver;
572 
573 	case ICMP6_TIME_EXCEEDED:
574 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed);
575 		switch (code) {
576 		case ICMP6_TIME_EXCEED_TRANSIT:
577 			code = PRC_TIMXCEED_INTRANS;
578 			break;
579 		case ICMP6_TIME_EXCEED_REASSEMBLY:
580 			code = PRC_TIMXCEED_REASS;
581 			break;
582 		default:
583 			goto badcode;
584 		}
585 		goto deliver;
586 
587 	case ICMP6_PARAM_PROB:
588 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob);
589 		switch (code) {
590 		case ICMP6_PARAMPROB_NEXTHEADER:
591 			code = PRC_UNREACH_PROTOCOL;
592 			break;
593 		case ICMP6_PARAMPROB_HEADER:
594 		case ICMP6_PARAMPROB_OPTION:
595 			code = PRC_PARAMPROB;
596 			break;
597 		default:
598 			goto badcode;
599 		}
600 		goto deliver;
601 
602 	case ICMP6_ECHO_REQUEST:
603 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo);
604 		if (code != 0)
605 			goto badcode;
606 		/*
607 		 * Copy mbuf to send to two data paths: userland socket(s),
608 		 * and to the querier (echo reply).
609 		 * m: a copy for socket, n: a copy for querier
610 		 *
611 		 * If the first mbuf is shared, or the first mbuf is too short,
612 		 * copy the first part of the data into a fresh mbuf.
613 		 * Otherwise, we will wrongly overwrite both copies.
614 		 */
615 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
616 			/* Give up local */
617 			n = m;
618 			m = NULL;
619 		} else if (M_READONLY(n) ||
620 		    n->m_len < off + sizeof(struct icmp6_hdr)) {
621 			struct mbuf *n0 = n;
622 
623 			/*
624 			 * Prepare an internal mbuf.  m_pullup() doesn't
625 			 * always copy the length we specified.
626 			 */
627 			if ((n = m_dup(n0, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
628 				/* Give up local */
629 				n = m;
630 				m = NULL;
631 			}
632 			m_freem(n0);
633 		}
634 		IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
635 		    sizeof(*nicmp6));
636 		nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
637 		nicmp6->icmp6_code = 0;
638 		if (n) {
639 			uint64_t *icmp6s = ICMP6_STAT_GETREF();
640 			icmp6s[ICMP6_STAT_REFLECT]++;
641 			icmp6s[ICMP6_STAT_OUTHIST + ICMP6_ECHO_REPLY]++;
642 			ICMP6_STAT_PUTREF();
643 			icmp6_reflect(n, off);
644 		}
645 		if (!m)
646 			goto freeit;
647 		break;
648 
649 	case ICMP6_ECHO_REPLY:
650 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply);
651 		if (code != 0)
652 			goto badcode;
653 		break;
654 
655 	case MLD_LISTENER_QUERY:
656 	case MLD_LISTENER_REPORT:
657 		if (icmp6len < sizeof(struct mld_hdr))
658 			goto badlen;
659 		if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */
660 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery);
661 		else
662 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport);
663 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
664 			/* give up local */
665 			mld_input(m, off);
666 			m = NULL;
667 			goto freeit;
668 		}
669 		mld_input(n, off);
670 		/* m stays. */
671 		break;
672 
673 	case MLD_LISTENER_DONE:
674 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone);
675 		if (icmp6len < sizeof(struct mld_hdr))	/* necessary? */
676 			goto badlen;
677 		break;		/* nothing to be done in kernel */
678 
679 	case MLD_MTRACE_RESP:
680 	case MLD_MTRACE:
681 		/* XXX: these two are experimental.  not officially defined. */
682 		/* XXX: per-interface statistics? */
683 		break;		/* just pass it to applications */
684 
685 	case ICMP6_WRUREQUEST:	/* ICMP6_FQDN_QUERY */
686 	    {
687 		enum { WRU, FQDN } mode;
688 
689 		if (!icmp6_nodeinfo)
690 			break;
691 
692 		if (icmp6len == sizeof(struct icmp6_hdr) + 4)
693 			mode = WRU;
694 		else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
695 			mode = FQDN;
696 		else
697 			goto badlen;
698 
699 		if (mode == FQDN) {
700 			n = m_copym(m, 0, M_COPYALL, M_DONTWAIT);
701 			if (n)
702 				n = ni6_input(n, off);
703 			/* XXX meaningless if n == NULL */
704 			noff = sizeof(struct ip6_hdr);
705 		} else {
706 			u_char *p;
707 			int maxhlen;
708 
709 			if ((icmp6_nodeinfo & 5) != 5)
710 				break;
711 
712 			if (code != 0)
713 				goto badcode;
714 			MGETHDR(n, M_DONTWAIT, m->m_type);
715 			if (n && ICMP6_MAXLEN > MHLEN) {
716 				MCLGET(n, M_DONTWAIT);
717 				if ((n->m_flags & M_EXT) == 0) {
718 					m_free(n);
719 					n = NULL;
720 				}
721 			}
722 			if (n == NULL) {
723 				/* Give up remote */
724 				break;
725 			}
726 			n->m_pkthdr.rcvif = NULL;
727 			n->m_len = 0;
728 			maxhlen = M_TRAILINGSPACE(n) - ICMP6_MAXLEN;
729 			if (maxhlen > hostnamelen)
730 				maxhlen = hostnamelen;
731 			/*
732 			 * Copy IPv6 and ICMPv6 only.
733 			 */
734 			nip6 = mtod(n, struct ip6_hdr *);
735 			bcopy(ip6, nip6, sizeof(struct ip6_hdr));
736 			nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
737 			bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
738 			p = (u_char *)(nicmp6 + 1);
739 			memset(p, 0, 4);
740 			bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */
741 			noff = sizeof(struct ip6_hdr);
742 			M_COPY_PKTHDR(n, m); /* just for rcvif */
743 			n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
744 				sizeof(struct icmp6_hdr) + 4 + maxhlen;
745 			nicmp6->icmp6_type = ICMP6_WRUREPLY;
746 			nicmp6->icmp6_code = 0;
747 		}
748 #undef hostnamelen
749 		if (n) {
750 			uint64_t *icmp6s = ICMP6_STAT_GETREF();
751 			icmp6s[ICMP6_STAT_REFLECT]++;
752 			icmp6s[ICMP6_STAT_OUTHIST + ICMP6_WRUREPLY]++;
753 			ICMP6_STAT_PUTREF();
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(m->m_pkthdr.rcvif, 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 			nd6_rs_input(m, off, icmp6len);
773 			m = NULL;
774 			goto freeit;
775 		}
776 		nd6_rs_input(n, off, icmp6len);
777 		/* m stays. */
778 		break;
779 
780 	case ND_ROUTER_ADVERT:
781 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert);
782 		if (code != 0)
783 			goto badcode;
784 		if (icmp6len < sizeof(struct nd_router_advert))
785 			goto badlen;
786 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
787 			/* give up local */
788 			nd6_ra_input(m, off, icmp6len);
789 			m = NULL;
790 			goto freeit;
791 		}
792 		nd6_ra_input(n, off, icmp6len);
793 		/* m stays. */
794 		break;
795 
796 	case ND_NEIGHBOR_SOLICIT:
797 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit);
798 		if (code != 0)
799 			goto badcode;
800 		if (icmp6len < sizeof(struct nd_neighbor_solicit))
801 			goto badlen;
802 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
803 			/* give up local */
804 			nd6_ns_input(m, off, icmp6len);
805 			m = NULL;
806 			goto freeit;
807 		}
808 		nd6_ns_input(n, off, icmp6len);
809 		/* m stays. */
810 		break;
811 
812 	case ND_NEIGHBOR_ADVERT:
813 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert);
814 		if (code != 0)
815 			goto badcode;
816 		if (icmp6len < sizeof(struct nd_neighbor_advert))
817 			goto badlen;
818 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
819 			/* give up local */
820 			nd6_na_input(m, off, icmp6len);
821 			m = NULL;
822 			goto freeit;
823 		}
824 		nd6_na_input(n, off, icmp6len);
825 		/* m stays. */
826 		break;
827 
828 	case ND_REDIRECT:
829 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect);
830 		if (code != 0)
831 			goto badcode;
832 		if (icmp6len < sizeof(struct nd_redirect))
833 			goto badlen;
834 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
835 			/* give up local */
836 			icmp6_redirect_input(m, off);
837 			m = NULL;
838 			goto freeit;
839 		}
840 		icmp6_redirect_input(n, off);
841 		/* m stays. */
842 		break;
843 
844 	case ICMP6_ROUTER_RENUMBERING:
845 		if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
846 		    code != ICMP6_ROUTER_RENUMBERING_RESULT)
847 			goto badcode;
848 		if (icmp6len < sizeof(struct icmp6_router_renum))
849 			goto badlen;
850 		break;
851 
852 	default:
853 		nd6log((LOG_DEBUG,
854 		    "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
855 		    icmp6->icmp6_type, ip6_sprintf(&ip6->ip6_src),
856 		    ip6_sprintf(&ip6->ip6_dst),
857 		    m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0));
858 		if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
859 			/* ICMPv6 error: MUST deliver it by spec... */
860 			code = PRC_NCMDS;
861 			/* deliver */
862 		} else {
863 			/* ICMPv6 informational: MUST not deliver */
864 			break;
865 		}
866 	deliver:
867 		if (icmp6_notify_error(m, off, icmp6len, code)) {
868 			/* In this case, m should've been freed. */
869 			return (IPPROTO_DONE);
870 		}
871 		break;
872 
873 	badcode:
874 		ICMP6_STATINC(ICMP6_STAT_BADCODE);
875 		break;
876 
877 	badlen:
878 		ICMP6_STATINC(ICMP6_STAT_BADLEN);
879 		break;
880 	}
881 
882 	/* deliver the packet to appropriate sockets */
883 	icmp6_rip6_input(&m, *offp);
884 
885 	return IPPROTO_DONE;
886 
887  freeit:
888 	m_freem(m);
889 	return IPPROTO_DONE;
890 }
891 
892 static int
893 icmp6_notify_error(struct mbuf *m, int off, int icmp6len, int code)
894 {
895 	struct icmp6_hdr *icmp6;
896 	struct ip6_hdr *eip6;
897 	u_int32_t notifymtu;
898 	struct sockaddr_in6 icmp6src, icmp6dst;
899 
900 	if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
901 		ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
902 		goto freeit;
903 	}
904 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
905 		       sizeof(*icmp6) + sizeof(struct ip6_hdr));
906 	if (icmp6 == NULL) {
907 		ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
908 		return (-1);
909 	}
910 	eip6 = (struct ip6_hdr *)(icmp6 + 1);
911 
912 	/* Detect the upper level protocol */
913 	{
914 		void (*ctlfunc)(int, struct sockaddr *, void *);
915 		u_int8_t nxt = eip6->ip6_nxt;
916 		int eoff = off + sizeof(struct icmp6_hdr) +
917 			sizeof(struct ip6_hdr);
918 		struct ip6ctlparam ip6cp;
919 		struct in6_addr *finaldst = NULL;
920 		int icmp6type = icmp6->icmp6_type;
921 		struct ip6_frag *fh;
922 		struct ip6_rthdr *rth;
923 		struct ip6_rthdr0 *rth0;
924 		int rthlen;
925 
926 		while (1) { /* XXX: should avoid infinite loop explicitly? */
927 			struct ip6_ext *eh;
928 
929 			switch (nxt) {
930 			case IPPROTO_HOPOPTS:
931 			case IPPROTO_DSTOPTS:
932 			case IPPROTO_AH:
933 				IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
934 					       eoff, sizeof(*eh));
935 				if (eh == NULL) {
936 					ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
937 					return (-1);
938 				}
939 
940 				if (nxt == IPPROTO_AH)
941 					eoff += (eh->ip6e_len + 2) << 2;
942 				else
943 					eoff += (eh->ip6e_len + 1) << 3;
944 				nxt = eh->ip6e_nxt;
945 				break;
946 			case IPPROTO_ROUTING:
947 				/*
948 				 * When the erroneous packet contains a
949 				 * routing header, we should examine the
950 				 * header to determine the final destination.
951 				 * Otherwise, we can't properly update
952 				 * information that depends on the final
953 				 * destination (e.g. path MTU).
954 				 */
955 				IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
956 					       eoff, sizeof(*rth));
957 				if (rth == NULL) {
958 					ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
959 					return (-1);
960 				}
961 				rthlen = (rth->ip6r_len + 1) << 3;
962 				/*
963 				 * XXX: currently there is no
964 				 * officially defined type other
965 				 * than type-0.
966 				 * Note that if the segment left field
967 				 * is 0, all intermediate hops must
968 				 * have been passed.
969 				 */
970 				if (rth->ip6r_segleft &&
971 				    rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
972 					int hops;
973 
974 					IP6_EXTHDR_GET(rth0,
975 						       struct ip6_rthdr0 *, m,
976 						       eoff, rthlen);
977 					if (rth0 == NULL) {
978 						ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
979 						return (-1);
980 					}
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 				IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
991 					       eoff, sizeof(*fh));
992 				if (fh == NULL) {
993 					ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
994 					return (-1);
995 				}
996 				/*
997 				 * Data after a fragment header is meaningless
998 				 * unless it is the first fragment, but
999 				 * we'll go to the notify label for path MTU
1000 				 * discovery.
1001 				 */
1002 				if (fh->ip6f_offlg & IP6F_OFF_MASK)
1003 					goto notify;
1004 
1005 				eoff += sizeof(struct ip6_frag);
1006 				nxt = fh->ip6f_nxt;
1007 				break;
1008 			default:
1009 				/*
1010 				 * This case includes ESP and the No Next
1011 				 * Header.  In such cases going to the notify
1012 				 * label does not have any meaning
1013 				 * (i.e. ctlfunc will be NULL), but we go
1014 				 * anyway since we might have to update
1015 				 * path MTU information.
1016 				 */
1017 				goto notify;
1018 			}
1019 		}
1020 	  notify:
1021 		IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1022 			       sizeof(*icmp6) + sizeof(struct ip6_hdr));
1023 		if (icmp6 == NULL) {
1024 			ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
1025 			return (-1);
1026 		}
1027 
1028 		/*
1029 		 * retrieve parameters from the inner IPv6 header, and convert
1030 		 * them into sockaddr structures.
1031 		 * XXX: there is no guarantee that the source or destination
1032 		 * addresses of the inner packet are in the same scope zone as
1033 		 * the addresses of the icmp packet.  But there is no other
1034 		 * way to determine the zone.
1035 		 */
1036 		eip6 = (struct ip6_hdr *)(icmp6 + 1);
1037 
1038 		sockaddr_in6_init(&icmp6dst,
1039 		    (finaldst == NULL) ? &eip6->ip6_dst : finaldst, 0, 0, 0);
1040 		if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1041 			goto freeit;
1042 		sockaddr_in6_init(&icmp6src, &eip6->ip6_src, 0, 0, 0);
1043 		if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1044 			goto freeit;
1045 		icmp6src.sin6_flowinfo =
1046 			(eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1047 
1048 		if (finaldst == NULL)
1049 			finaldst = &eip6->ip6_dst;
1050 		ip6cp.ip6c_m = m;
1051 		ip6cp.ip6c_icmp6 = icmp6;
1052 		ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1053 		ip6cp.ip6c_off = eoff;
1054 		ip6cp.ip6c_finaldst = finaldst;
1055 		ip6cp.ip6c_src = &icmp6src;
1056 		ip6cp.ip6c_nxt = nxt;
1057 
1058 		if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1059 			notifymtu = ntohl(icmp6->icmp6_mtu);
1060 			ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1061 		}
1062 
1063 		ctlfunc = (void (*)(int, struct sockaddr *, void *))
1064 			(inet6sw[ip6_protox[nxt]].pr_ctlinput);
1065 		if (ctlfunc) {
1066 			(void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1067 					  &ip6cp);
1068 		}
1069 	}
1070 	return (0);
1071 
1072   freeit:
1073 	m_freem(m);
1074 	return (-1);
1075 }
1076 
1077 void
1078 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1079 {
1080 	unsigned long rtcount;
1081 	struct icmp6_mtudisc_callback *mc;
1082 	struct in6_addr *dst = ip6cp->ip6c_finaldst;
1083 	struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1084 	struct mbuf *m = ip6cp->ip6c_m;	/* will be necessary for scope issue */
1085 	u_int mtu = ntohl(icmp6->icmp6_mtu);
1086 	struct rtentry *rt = NULL;
1087 	struct sockaddr_in6 sin6;
1088 
1089 	/*
1090 	 * The MTU should not be less than the minimal IPv6 MTU except for the
1091 	 * hack in ip6_output/ip6_setpmtu where we always include a frag header.
1092 	 * In that one case, the MTU might be less than 1280.
1093 	 */
1094 	if (__predict_false(mtu < IPV6_MMTU - sizeof(struct ip6_frag))) {
1095 		/* is the mtu even sane? */
1096 		if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1097 			return;
1098 		if (!validated)
1099 			return;
1100 		mtu = IPV6_MMTU - sizeof(struct ip6_frag);
1101 	}
1102 
1103 	/*
1104 	 * allow non-validated cases if memory is plenty, to make traffic
1105 	 * from non-connected pcb happy.
1106 	 */
1107 	rtcount = rt_timer_count(icmp6_mtudisc_timeout_q);
1108 	if (validated) {
1109 		if (0 <= icmp6_mtudisc_hiwat && rtcount > icmp6_mtudisc_hiwat)
1110 			return;
1111 		else if (0 <= icmp6_mtudisc_lowat &&
1112 		    rtcount > icmp6_mtudisc_lowat) {
1113 			/*
1114 			 * XXX nuke a victim, install the new one.
1115 			 */
1116 		}
1117 	} else {
1118 		if (0 <= icmp6_mtudisc_lowat && rtcount > icmp6_mtudisc_lowat)
1119 			return;
1120 	}
1121 
1122 	memset(&sin6, 0, sizeof(sin6));
1123 	sin6.sin6_family = PF_INET6;
1124 	sin6.sin6_len = sizeof(struct sockaddr_in6);
1125 	sin6.sin6_addr = *dst;
1126 	if (in6_setscope(&sin6.sin6_addr, m->m_pkthdr.rcvif, NULL))
1127 		return;
1128 
1129 	rt = icmp6_mtudisc_clone((struct sockaddr *)&sin6);
1130 
1131 	if (rt && (rt->rt_flags & RTF_HOST) &&
1132 	    !(rt->rt_rmx.rmx_locks & RTV_MTU) &&
1133 	    (rt->rt_rmx.rmx_mtu > mtu || rt->rt_rmx.rmx_mtu == 0)) {
1134 		if (mtu < IN6_LINKMTU(rt->rt_ifp)) {
1135 			ICMP6_STATINC(ICMP6_STAT_PMTUCHG);
1136 			rt->rt_rmx.rmx_mtu = mtu;
1137 		}
1138 	}
1139 	if (rt) { /* XXX: need braces to avoid conflict with else in RTFREE. */
1140 		RTFREE(rt);
1141 	}
1142 
1143 	/*
1144 	 * Notify protocols that the MTU for this destination
1145 	 * has changed.
1146 	 */
1147 	for (mc = LIST_FIRST(&icmp6_mtudisc_callbacks); mc != NULL;
1148 	     mc = LIST_NEXT(mc, mc_list))
1149 		(*mc->mc_func)(&sin6.sin6_addr);
1150 }
1151 
1152 /*
1153  * Process a Node Information Query packet, based on
1154  * draft-ietf-ipngwg-icmp-name-lookups-07.
1155  *
1156  * Spec incompatibilities:
1157  * - IPv6 Subject address handling
1158  * - IPv4 Subject address handling support missing
1159  * - Proxy reply (answer even if it's not for me)
1160  * - joins NI group address at in6_ifattach() time only, does not cope
1161  *   with hostname changes by sethostname(3)
1162  */
1163 #ifndef offsetof		/* XXX */
1164 #define	offsetof(type, member)	((size_t)(&((type *)0)->member))
1165 #endif
1166 static struct mbuf *
1167 ni6_input(struct mbuf *m, int off)
1168 {
1169 	struct icmp6_nodeinfo *ni6, *nni6;
1170 	struct mbuf *n = NULL;
1171 	u_int16_t qtype;
1172 	int subjlen;
1173 	int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1174 	struct ni_reply_fqdn *fqdn;
1175 	int addrs;		/* for NI_QTYPE_NODEADDR */
1176 	struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1177 	struct sockaddr_in6 sin6; /* ip6_dst */
1178 	struct in6_addr in6_subj; /* subject address */
1179 	struct ip6_hdr *ip6;
1180 	int oldfqdn = 0;	/* if 1, return pascal string (03 draft) */
1181 	char *subj = NULL;
1182 
1183 	ip6 = mtod(m, struct ip6_hdr *);
1184 	IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1185 	if (ni6 == NULL) {
1186 		/* m is already reclaimed */
1187 		return NULL;
1188 	}
1189 
1190 	/*
1191 	 * Validate IPv6 destination address.
1192 	 *
1193 	 * The Responder must discard the Query without further processing
1194 	 * unless it is one of the Responder's unicast or anycast addresses, or
1195 	 * a link-local scope multicast address which the Responder has joined.
1196 	 * [icmp-name-lookups-07, Section 4.]
1197 	 */
1198 	sockaddr_in6_init(&sin6, &ip6->ip6_dst, 0, 0, 0);
1199 	/* XXX scopeid */
1200 	if (ifa_ifwithaddr((struct sockaddr *)&sin6))
1201 		; /* unicast/anycast, fine */
1202 	else if (IN6_IS_ADDR_MC_LINKLOCAL(&sin6.sin6_addr))
1203 		; /* link-local multicast, fine */
1204 	else
1205 		goto bad;
1206 
1207 	/* validate query Subject field. */
1208 	qtype = ntohs(ni6->ni_qtype);
1209 	subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1210 	switch (qtype) {
1211 	case NI_QTYPE_NOOP:
1212 	case NI_QTYPE_SUPTYPES:
1213 		/* 07 draft */
1214 		if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1215 			break;
1216 		/* FALLTHROUGH */
1217 	case NI_QTYPE_FQDN:
1218 	case NI_QTYPE_NODEADDR:
1219 	case NI_QTYPE_IPV4ADDR:
1220 		switch (ni6->ni_code) {
1221 		case ICMP6_NI_SUBJ_IPV6:
1222 #if ICMP6_NI_SUBJ_IPV6 != 0
1223 		case 0:
1224 #endif
1225 			/*
1226 			 * backward compatibility - try to accept 03 draft
1227 			 * format, where no Subject is present.
1228 			 */
1229 			if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1230 			    subjlen == 0) {
1231 				oldfqdn++;
1232 				break;
1233 			}
1234 #if ICMP6_NI_SUBJ_IPV6 != 0
1235 			if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1236 				goto bad;
1237 #endif
1238 
1239 			if (subjlen != sizeof(sin6.sin6_addr))
1240 				goto bad;
1241 
1242 			/*
1243 			 * Validate Subject address.
1244 			 *
1245 			 * Not sure what exactly "address belongs to the node"
1246 			 * means in the spec, is it just unicast, or what?
1247 			 *
1248 			 * At this moment we consider Subject address as
1249 			 * "belong to the node" if the Subject address equals
1250 			 * to the IPv6 destination address; validation for
1251 			 * IPv6 destination address should have done enough
1252 			 * check for us.
1253 			 *
1254 			 * We do not do proxy at this moment.
1255 			 */
1256 			/* m_pulldown instead of copy? */
1257 			m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1258 			    subjlen, (void *)&in6_subj);
1259 			if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1260 				goto bad;
1261 
1262 			subj = (char *)&in6_subj;
1263 			if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1264 				break;
1265 
1266 			/*
1267 			 * XXX if we are to allow other cases, we should really
1268 			 * be careful about scope here.
1269 			 * basically, we should disallow queries toward IPv6
1270 			 * destination X with subject Y, if scope(X) > scope(Y).
1271 			 * if we allow scope(X) > scope(Y), it will result in
1272 			 * information leakage across scope boundary.
1273 			 */
1274 			goto bad;
1275 
1276 		case ICMP6_NI_SUBJ_FQDN:
1277 			/*
1278 			 * Validate Subject name with gethostname(3).
1279 			 *
1280 			 * The behavior may need some debate, since:
1281 			 * - we are not sure if the node has FQDN as
1282 			 *   hostname (returned by gethostname(3)).
1283 			 * - the code does wildcard match for truncated names.
1284 			 *   however, we are not sure if we want to perform
1285 			 *   wildcard match, if gethostname(3) side has
1286 			 *   truncated hostname.
1287 			 */
1288 			n = ni6_nametodns(hostname, hostnamelen, 0);
1289 			if (!n || n->m_next || n->m_len == 0)
1290 				goto bad;
1291 			IP6_EXTHDR_GET(subj, char *, m,
1292 			    off + sizeof(struct icmp6_nodeinfo), subjlen);
1293 			if (subj == NULL)
1294 				goto bad;
1295 			if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1296 					n->m_len)) {
1297 				goto bad;
1298 			}
1299 			m_freem(n);
1300 			n = NULL;
1301 			break;
1302 
1303 		case ICMP6_NI_SUBJ_IPV4:	/* XXX: to be implemented? */
1304 		default:
1305 			goto bad;
1306 		}
1307 		break;
1308 	}
1309 
1310 	/* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1311 	switch (qtype) {
1312 	case NI_QTYPE_FQDN:
1313 		if ((icmp6_nodeinfo & 1) == 0)
1314 			goto bad;
1315 		break;
1316 	case NI_QTYPE_NODEADDR:
1317 	case NI_QTYPE_IPV4ADDR:
1318 		if ((icmp6_nodeinfo & 2) == 0)
1319 			goto bad;
1320 		break;
1321 	}
1322 
1323 	/* guess reply length */
1324 	switch (qtype) {
1325 	case NI_QTYPE_NOOP:
1326 		break;		/* no reply data */
1327 	case NI_QTYPE_SUPTYPES:
1328 		replylen += sizeof(u_int32_t);
1329 		break;
1330 	case NI_QTYPE_FQDN:
1331 		/* XXX will append an mbuf */
1332 		replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1333 		break;
1334 	case NI_QTYPE_NODEADDR:
1335 		addrs = ni6_addrs(ni6, m, &ifp, subj);
1336 		if ((replylen += addrs * (sizeof(struct in6_addr) +
1337 					  sizeof(u_int32_t))) > MCLBYTES)
1338 			replylen = MCLBYTES; /* XXX: will truncate pkt later */
1339 		break;
1340 	case NI_QTYPE_IPV4ADDR:
1341 		/* unsupported - should respond with unknown Qtype? */
1342 		goto bad;
1343 	default:
1344 		/*
1345 		 * XXX: We must return a reply with the ICMP6 code
1346 		 * `unknown Qtype' in this case.  However we regard the case
1347 		 * as an FQDN query for backward compatibility.
1348 		 * Older versions set a random value to this field,
1349 		 * so it rarely varies in the defined qtypes.
1350 		 * But the mechanism is not reliable...
1351 		 * maybe we should obsolete older versions.
1352 		 */
1353 		qtype = NI_QTYPE_FQDN;
1354 		/* XXX will append an mbuf */
1355 		replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1356 		oldfqdn++;
1357 		break;
1358 	}
1359 
1360 	/* allocate an mbuf to reply. */
1361 	MGETHDR(n, M_DONTWAIT, m->m_type);
1362 	if (n == NULL) {
1363 		m_freem(m);
1364 		return (NULL);
1365 	}
1366 	M_MOVE_PKTHDR(n, m); /* just for rcvif */
1367 	if (replylen > MHLEN) {
1368 		if (replylen > MCLBYTES) {
1369 			/*
1370 			 * XXX: should we try to allocate more? But MCLBYTES
1371 			 * is probably much larger than IPV6_MMTU...
1372 			 */
1373 			goto bad;
1374 		}
1375 		MCLGET(n, M_DONTWAIT);
1376 		if ((n->m_flags & M_EXT) == 0) {
1377 			goto bad;
1378 		}
1379 	}
1380 	n->m_pkthdr.len = n->m_len = replylen;
1381 
1382 	/* copy mbuf header and IPv6 + Node Information base headers */
1383 	bcopy(mtod(m, void *), mtod(n, void *), sizeof(struct ip6_hdr));
1384 	nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1385 	bcopy((void *)ni6, (void *)nni6, sizeof(struct icmp6_nodeinfo));
1386 
1387 	/* qtype dependent procedure */
1388 	switch (qtype) {
1389 	case NI_QTYPE_NOOP:
1390 		nni6->ni_code = ICMP6_NI_SUCCESS;
1391 		nni6->ni_flags = 0;
1392 		break;
1393 	case NI_QTYPE_SUPTYPES:
1394 	{
1395 		u_int32_t v;
1396 		nni6->ni_code = ICMP6_NI_SUCCESS;
1397 		nni6->ni_flags = htons(0x0000);	/* raw bitmap */
1398 		/* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1399 		v = (u_int32_t)htonl(0x0000000f);
1400 		bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1401 		break;
1402 	}
1403 	case NI_QTYPE_FQDN:
1404 		nni6->ni_code = ICMP6_NI_SUCCESS;
1405 		fqdn = (struct ni_reply_fqdn *)(mtod(n, char *) +
1406 						sizeof(struct ip6_hdr) +
1407 						sizeof(struct icmp6_nodeinfo));
1408 		nni6->ni_flags = 0; /* XXX: meaningless TTL */
1409 		fqdn->ni_fqdn_ttl = 0;	/* ditto. */
1410 		/*
1411 		 * XXX do we really have FQDN in variable "hostname"?
1412 		 */
1413 		n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn);
1414 		if (n->m_next == NULL)
1415 			goto bad;
1416 		/* XXX we assume that n->m_next is not a chain */
1417 		if (n->m_next->m_next != NULL)
1418 			goto bad;
1419 		n->m_pkthdr.len += n->m_next->m_len;
1420 		break;
1421 	case NI_QTYPE_NODEADDR:
1422 	{
1423 		int lenlim, copied;
1424 
1425 		nni6->ni_code = ICMP6_NI_SUCCESS;
1426 		n->m_pkthdr.len = n->m_len =
1427 		    sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1428 		lenlim = M_TRAILINGSPACE(n);
1429 		copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1430 		/* XXX: reset mbuf length */
1431 		n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1432 			sizeof(struct icmp6_nodeinfo) + copied;
1433 		break;
1434 	}
1435 	default:
1436 		break;		/* XXX impossible! */
1437 	}
1438 
1439 	nni6->ni_type = ICMP6_NI_REPLY;
1440 	m_freem(m);
1441 	return (n);
1442 
1443   bad:
1444 	m_freem(m);
1445 	if (n)
1446 		m_freem(n);
1447 	return (NULL);
1448 }
1449 #undef hostnamelen
1450 
1451 #define isupper(x) ('A' <= (x) && (x) <= 'Z')
1452 #define isalpha(x) (('A' <= (x) && (x) <= 'Z') || ('a' <= (x) && (x) <= 'z'))
1453 #define isalnum(x) (isalpha(x) || ('0' <= (x) && (x) <= '9'))
1454 #define tolower(x) (isupper(x) ? (x) + 'a' - 'A' : (x))
1455 
1456 /*
1457  * make a mbuf with DNS-encoded string.  no compression support.
1458  *
1459  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1460  * treated as truncated name (two \0 at the end).  this is a wild guess.
1461  *
1462  * old - return pascal string if non-zero
1463  */
1464 static struct mbuf *
1465 ni6_nametodns(const char *name, int namelen, int old)
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 			if (!isalpha(p[0]) || !isalnum(p[i - 1]))
1533 				goto fail;
1534 			while (i > 0) {
1535 				if (!isalnum(*p) && *p != '-')
1536 					goto fail;
1537 				if (isupper(*p)) {
1538 					*cp++ = tolower(*p);
1539 					p++;
1540 				} else
1541 					*cp++ = *p++;
1542 				i--;
1543 			}
1544 			p = q;
1545 			if (p < name + namelen && *p == '.')
1546 				p++;
1547 		}
1548 		/* termination */
1549 		if (cp + nterm >= ep)
1550 			goto fail;
1551 		while (nterm-- > 0)
1552 			*cp++ = '\0';
1553 		m->m_len = cp - mtod(m, char *);
1554 		return m;
1555 	}
1556 
1557 	panic("should not reach here");
1558 	/* NOTREACHED */
1559 
1560  fail:
1561 	if (m)
1562 		m_freem(m);
1563 	return NULL;
1564 }
1565 
1566 /*
1567  * check if two DNS-encoded string matches.  takes care of truncated
1568  * form (with \0\0 at the end).  no compression support.
1569  * XXX upper/lowercase match (see RFC2065)
1570  */
1571 static int
1572 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1573 {
1574 	const char *a0, *b0;
1575 	int l;
1576 
1577 	/* simplest case - need validation? */
1578 	if (alen == blen && memcmp(a, b, alen) == 0)
1579 		return 1;
1580 
1581 	a0 = a;
1582 	b0 = b;
1583 
1584 	/* termination is mandatory */
1585 	if (alen < 2 || blen < 2)
1586 		return 0;
1587 	if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1588 		return 0;
1589 	alen--;
1590 	blen--;
1591 
1592 	while (a - a0 < alen && b - b0 < blen) {
1593 		if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1594 			return 0;
1595 
1596 		if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1597 			return 0;
1598 		/* we don't support compression yet */
1599 		if (a[0] >= 64 || b[0] >= 64)
1600 			return 0;
1601 
1602 		/* truncated case */
1603 		if (a[0] == 0 && a - a0 == alen - 1)
1604 			return 1;
1605 		if (b[0] == 0 && b - b0 == blen - 1)
1606 			return 1;
1607 		if (a[0] == 0 || b[0] == 0)
1608 			return 0;
1609 
1610 		if (a[0] != b[0])
1611 			return 0;
1612 		l = a[0];
1613 		if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1614 			return 0;
1615 		if (memcmp(a + 1, b + 1, l) != 0)
1616 			return 0;
1617 
1618 		a += 1 + l;
1619 		b += 1 + l;
1620 	}
1621 
1622 	if (a - a0 == alen && b - b0 == blen)
1623 		return 1;
1624 	else
1625 		return 0;
1626 }
1627 
1628 /*
1629  * calculate the number of addresses to be returned in the node info reply.
1630  */
1631 static int
1632 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m,
1633     struct ifnet **ifpp, char *subj)
1634 {
1635 	struct ifnet *ifp;
1636 	struct in6_ifaddr *ifa6;
1637 	struct ifaddr *ifa;
1638 	struct sockaddr_in6 *subj_ip6 = NULL; /* XXX pedant */
1639 	int addrs = 0, addrsofif, iffound = 0;
1640 	int niflags = ni6->ni_flags;
1641 
1642 	if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1643 		switch (ni6->ni_code) {
1644 		case ICMP6_NI_SUBJ_IPV6:
1645 			if (subj == NULL) /* must be impossible... */
1646 				return (0);
1647 			subj_ip6 = (struct sockaddr_in6 *)subj;
1648 			break;
1649 		default:
1650 			/*
1651 			 * XXX: we only support IPv6 subject address for
1652 			 * this Qtype.
1653 			 */
1654 			return (0);
1655 		}
1656 	}
1657 
1658 	IFNET_FOREACH(ifp) {
1659 		addrsofif = 0;
1660 		IFADDR_FOREACH(ifa, ifp) {
1661 			if (ifa->ifa_addr->sa_family != AF_INET6)
1662 				continue;
1663 			ifa6 = (struct in6_ifaddr *)ifa;
1664 
1665 			if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1666 			    IN6_ARE_ADDR_EQUAL(&subj_ip6->sin6_addr,
1667 					       &ifa6->ia_addr.sin6_addr))
1668 				iffound = 1;
1669 
1670 			/*
1671 			 * IPv4-mapped addresses can only be returned by a
1672 			 * Node Information proxy, since they represent
1673 			 * addresses of IPv4-only nodes, which perforce do
1674 			 * not implement this protocol.
1675 			 * [icmp-name-lookups-07, Section 5.4]
1676 			 * So we don't support NI_NODEADDR_FLAG_COMPAT in
1677 			 * this function at this moment.
1678 			 */
1679 
1680 			/* What do we have to do about ::1? */
1681 			switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1682 			case IPV6_ADDR_SCOPE_LINKLOCAL:
1683 				if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1684 					continue;
1685 				break;
1686 			case IPV6_ADDR_SCOPE_SITELOCAL:
1687 				if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1688 					continue;
1689 				break;
1690 			case IPV6_ADDR_SCOPE_GLOBAL:
1691 				if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1692 					continue;
1693 				break;
1694 			default:
1695 				continue;
1696 			}
1697 
1698 			/*
1699 			 * check if anycast is okay.
1700 			 * XXX: just experimental.  not in the spec.
1701 			 */
1702 			if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1703 			    (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1704 				continue; /* we need only unicast addresses */
1705 
1706 			addrsofif++; /* count the address */
1707 		}
1708 		if (iffound) {
1709 			*ifpp = ifp;
1710 			return (addrsofif);
1711 		}
1712 
1713 		addrs += addrsofif;
1714 	}
1715 
1716 	return (addrs);
1717 }
1718 
1719 static int
1720 ni6_store_addrs(struct icmp6_nodeinfo *ni6,
1721 	struct icmp6_nodeinfo *nni6, struct ifnet *ifp0,
1722 	int resid)
1723 {
1724 	struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet);
1725 	struct in6_ifaddr *ifa6;
1726 	struct ifaddr *ifa;
1727 	struct ifnet *ifp_dep = NULL;
1728 	int copied = 0, allow_deprecated = 0;
1729 	u_char *cp = (u_char *)(nni6 + 1);
1730 	int niflags = ni6->ni_flags;
1731 	u_int32_t ltime;
1732 
1733 	if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1734 		return (0);	/* needless to copy */
1735 
1736   again:
1737 
1738 	for (; ifp; ifp = TAILQ_NEXT(ifp, if_list))
1739 	{
1740 		IFADDR_FOREACH(ifa, ifp) {
1741 			if (ifa->ifa_addr->sa_family != AF_INET6)
1742 				continue;
1743 			ifa6 = (struct in6_ifaddr *)ifa;
1744 
1745 			if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1746 			    allow_deprecated == 0) {
1747 				/*
1748 				 * prefererred address should be put before
1749 				 * deprecated addresses.
1750 				 */
1751 
1752 				/* record the interface for later search */
1753 				if (ifp_dep == NULL)
1754 					ifp_dep = ifp;
1755 
1756 				continue;
1757 			}
1758 			else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1759 				 allow_deprecated != 0)
1760 				continue; /* we now collect deprecated addrs */
1761 
1762 			/* What do we have to do about ::1? */
1763 			switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1764 			case IPV6_ADDR_SCOPE_LINKLOCAL:
1765 				if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1766 					continue;
1767 				break;
1768 			case IPV6_ADDR_SCOPE_SITELOCAL:
1769 				if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1770 					continue;
1771 				break;
1772 			case IPV6_ADDR_SCOPE_GLOBAL:
1773 				if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1774 					continue;
1775 				break;
1776 			default:
1777 				continue;
1778 			}
1779 
1780 			/*
1781 			 * check if anycast is okay.
1782 			 * XXX: just experimental.  not in the spec.
1783 			 */
1784 			if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1785 			    (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1786 				continue;
1787 
1788 			/* now we can copy the address */
1789 			if (resid < sizeof(struct in6_addr) +
1790 			    sizeof(u_int32_t)) {
1791 				/*
1792 				 * We give up much more copy.
1793 				 * Set the truncate flag and return.
1794 				 */
1795 				nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1796 				return (copied);
1797 			}
1798 
1799 			/*
1800 			 * Set the TTL of the address.
1801 			 * The TTL value should be one of the following
1802 			 * according to the specification:
1803 			 *
1804 			 * 1. The remaining lifetime of a DHCP lease on the
1805 			 *    address, or
1806 			 * 2. The remaining Valid Lifetime of a prefix from
1807 			 *    which the address was derived through Stateless
1808 			 *    Autoconfiguration.
1809 			 *
1810 			 * Note that we currently do not support stateful
1811 			 * address configuration by DHCPv6, so the former
1812 			 * case can't happen.
1813 			 *
1814 			 * TTL must be 2^31 > TTL >= 0.
1815 			 */
1816 			if (ifa6->ia6_lifetime.ia6t_expire == 0)
1817 				ltime = ND6_INFINITE_LIFETIME;
1818 			else {
1819 				if (ifa6->ia6_lifetime.ia6t_expire >
1820 				    time_second)
1821 					ltime = ifa6->ia6_lifetime.ia6t_expire -
1822 					    time_second;
1823 				else
1824 					ltime = 0;
1825 			}
1826 			if (ltime > 0x7fffffff)
1827 				ltime = 0x7fffffff;
1828 			ltime = htonl(ltime);
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 	return (copied);
1854 }
1855 
1856 /*
1857  * XXX almost dup'ed code with rip6_input.
1858  */
1859 static int
1860 icmp6_rip6_input(struct mbuf **mp, int off)
1861 {
1862 	struct mbuf *m = *mp;
1863 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1864 	struct inpcb_hdr *inph;
1865 	struct in6pcb *in6p;
1866 	struct in6pcb *last = NULL;
1867 	struct sockaddr_in6 rip6src;
1868 	struct icmp6_hdr *icmp6;
1869 	struct mbuf *opts = NULL;
1870 
1871 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1872 	if (icmp6 == NULL) {
1873 		/* m is already reclaimed */
1874 		return IPPROTO_DONE;
1875 	}
1876 
1877 	/*
1878 	 * XXX: the address may have embedded scope zone ID, which should be
1879 	 * hidden from applications.
1880 	 */
1881 	sockaddr_in6_init(&rip6src, &ip6->ip6_src, 0, 0, 0);
1882 	if (sa6_recoverscope(&rip6src)) {
1883 		m_freem(m);
1884 		return (IPPROTO_DONE);
1885 	}
1886 
1887 	CIRCLEQ_FOREACH(inph, &raw6cbtable.inpt_queue, inph_queue) {
1888 		in6p = (struct in6pcb *)inph;
1889 		if (in6p->in6p_af != AF_INET6)
1890 			continue;
1891 		if (in6p->in6p_ip6.ip6_nxt != IPPROTO_ICMPV6)
1892 			continue;
1893 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1894 		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1895 			continue;
1896 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1897 		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1898 			continue;
1899 		if (in6p->in6p_icmp6filt
1900 		    && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1901 				 in6p->in6p_icmp6filt))
1902 			continue;
1903 		if (last) {
1904 			struct	mbuf *n;
1905 			if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
1906 				if (last->in6p_flags & IN6P_CONTROLOPTS)
1907 					ip6_savecontrol(last, &opts, ip6, n);
1908 				/* strip intermediate headers */
1909 				m_adj(n, off);
1910 				if (sbappendaddr(&last->in6p_socket->so_rcv,
1911 						 (struct sockaddr *)&rip6src,
1912 						 n, opts) == 0) {
1913 					/* should notify about lost packet */
1914 					m_freem(n);
1915 					if (opts)
1916 						m_freem(opts);
1917 				} else
1918 					sorwakeup(last->in6p_socket);
1919 				opts = NULL;
1920 			}
1921 		}
1922 		last = in6p;
1923 	}
1924 	if (last) {
1925 		if (last->in6p_flags & IN6P_CONTROLOPTS)
1926 			ip6_savecontrol(last, &opts, ip6, m);
1927 		/* strip intermediate headers */
1928 		m_adj(m, off);
1929 		if (sbappendaddr(&last->in6p_socket->so_rcv,
1930 				(struct sockaddr *)&rip6src, m, opts) == 0) {
1931 			m_freem(m);
1932 			if (opts)
1933 				m_freem(opts);
1934 		} else
1935 			sorwakeup(last->in6p_socket);
1936 	} else {
1937 		m_freem(m);
1938 		IP6_STATDEC(IP6_STAT_DELIVERED);
1939 	}
1940 	return IPPROTO_DONE;
1941 }
1942 
1943 /*
1944  * Reflect the ip6 packet back to the source.
1945  * OFF points to the icmp6 header, counted from the top of the mbuf.
1946  *
1947  * Note: RFC 1885 required that an echo reply should be truncated if it
1948  * did not fit in with (return) path MTU, and KAME code supported the
1949  * behavior.  However, as a clarification after the RFC, this limitation
1950  * was removed in a revised version of the spec, RFC 2463.  We had kept the
1951  * old behavior, with a (non-default) ifdef block, while the new version of
1952  * the spec was an internet-draft status, and even after the new RFC was
1953  * published.  But it would rather make sense to clean the obsoleted part
1954  * up, and to make the code simpler at this stage.
1955  */
1956 void
1957 icmp6_reflect(struct mbuf *m, size_t off)
1958 {
1959 	struct ip6_hdr *ip6;
1960 	struct icmp6_hdr *icmp6;
1961 	const struct in6_ifaddr *ia;
1962 	const struct ip6aux *ip6a;
1963 	int plen;
1964 	int type, code;
1965 	struct ifnet *outif = NULL;
1966 	struct in6_addr origdst;
1967 	const struct in6_addr *src = NULL;
1968 
1969 	/* too short to reflect */
1970 	if (off < sizeof(struct ip6_hdr)) {
1971 		nd6log((LOG_DEBUG,
1972 		    "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
1973 		    (u_long)off, (u_long)sizeof(struct ip6_hdr),
1974 		    __FILE__, __LINE__));
1975 		goto bad;
1976 	}
1977 
1978 	/*
1979 	 * If there are extra headers between IPv6 and ICMPv6, strip
1980 	 * off that header first.
1981 	 */
1982 #ifdef DIAGNOSTIC
1983 	if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
1984 		panic("assumption failed in icmp6_reflect");
1985 #endif
1986 	if (off > sizeof(struct ip6_hdr)) {
1987 		size_t l;
1988 		struct ip6_hdr nip6;
1989 
1990 		l = off - sizeof(struct ip6_hdr);
1991 		m_copydata(m, 0, sizeof(nip6), (void *)&nip6);
1992 		m_adj(m, l);
1993 		l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
1994 		if (m->m_len < l) {
1995 			if ((m = m_pullup(m, l)) == NULL)
1996 				return;
1997 		}
1998 		bcopy((void *)&nip6, mtod(m, void *), sizeof(nip6));
1999 	} else /* off == sizeof(struct ip6_hdr) */ {
2000 		size_t l;
2001 		l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2002 		if (m->m_len < l) {
2003 			if ((m = m_pullup(m, l)) == NULL)
2004 				return;
2005 		}
2006 	}
2007 	plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2008 	ip6 = mtod(m, struct ip6_hdr *);
2009 	ip6->ip6_nxt = IPPROTO_ICMPV6;
2010 	icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2011 	type = icmp6->icmp6_type; /* keep type for statistics */
2012 	code = icmp6->icmp6_code; /* ditto. */
2013 
2014 	origdst = ip6->ip6_dst;
2015 	/*
2016 	 * ip6_input() drops a packet if its src is multicast.
2017 	 * So, the src is never multicast.
2018 	 */
2019 	ip6->ip6_dst = ip6->ip6_src;
2020 
2021 	/*
2022 	 * If the incoming packet was addressed directly to us (i.e. unicast),
2023 	 * use dst as the src for the reply.
2024 	 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2025 	 * (for example) when we encounter an error while forwarding procedure
2026 	 * destined to a duplicated address of ours.
2027 	 * Note that ip6_getdstifaddr() may fail if we are in an error handling
2028 	 * procedure of an outgoing packet of our own, in which case we need
2029 	 * to search in the ifaddr list.
2030 	 */
2031 	if (IN6_IS_ADDR_MULTICAST(&origdst))
2032 		;
2033 	else if ((ip6a = ip6_getdstifaddr(m)) != NULL) {
2034 		if ((ip6a->ip6a_flags &
2035 		     (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0)
2036 			src = &ip6a->ip6a_src;
2037 	} else {
2038 		union {
2039 			struct sockaddr_in6 sin6;
2040 			struct sockaddr sa;
2041 		} u;
2042 
2043 		sockaddr_in6_init(&u.sin6, &origdst, 0, 0, 0);
2044 
2045 		ia = (struct in6_ifaddr *)ifa_ifwithaddr(&u.sa);
2046 
2047 		if (ia == NULL)
2048 			;
2049 		else if ((ia->ia6_flags &
2050 			 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0)
2051 			src = &ia->ia_addr.sin6_addr;
2052 	}
2053 
2054 	if (src == NULL) {
2055 		int e;
2056 		struct sockaddr_in6 sin6;
2057 		struct route ro;
2058 
2059 		/*
2060 		 * This case matches to multicasts, our anycast, or unicasts
2061 		 * that we do not own.  Select a source address based on the
2062 		 * source address of the erroneous packet.
2063 		 */
2064 		/* zone ID should be embedded */
2065 		sockaddr_in6_init(&sin6, &ip6->ip6_dst, 0, 0, 0);
2066 
2067 		memset(&ro, 0, sizeof(ro));
2068 		src = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &e);
2069 		rtcache_free(&ro);
2070 		if (src == NULL) {
2071 			nd6log((LOG_DEBUG,
2072 			    "icmp6_reflect: source can't be determined: "
2073 			    "dst=%s, error=%d\n",
2074 			    ip6_sprintf(&sin6.sin6_addr), e));
2075 			goto bad;
2076 		}
2077 	}
2078 
2079 	ip6->ip6_src = *src;
2080 	ip6->ip6_flow = 0;
2081 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2082 	ip6->ip6_vfc |= IPV6_VERSION;
2083 	ip6->ip6_nxt = IPPROTO_ICMPV6;
2084 	if (m->m_pkthdr.rcvif) {
2085 		/* XXX: This may not be the outgoing interface */
2086 		ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2087 	} else
2088 		ip6->ip6_hlim = ip6_defhlim;
2089 
2090 	m->m_pkthdr.csum_flags = 0;
2091 	icmp6->icmp6_cksum = 0;
2092 	icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2093 					sizeof(struct ip6_hdr), plen);
2094 
2095 	/*
2096 	 * XXX option handling
2097 	 */
2098 
2099 	m->m_flags &= ~(M_BCAST|M_MCAST);
2100 
2101 	/*
2102 	 * To avoid a "too big" situation at an intermediate router
2103 	 * and the path MTU discovery process, specify the IPV6_MINMTU flag.
2104 	 * Note that only echo and node information replies are affected,
2105 	 * since the length of ICMP6 errors is limited to the minimum MTU.
2106 	 */
2107 	if (ip6_output(m, NULL, NULL, IPV6_MINMTU, NULL, NULL, &outif) != 0 &&
2108 	    outif)
2109 		icmp6_ifstat_inc(outif, ifs6_out_error);
2110 
2111 	if (outif)
2112 		icmp6_ifoutstat_inc(outif, type, code);
2113 
2114 	return;
2115 
2116  bad:
2117 	m_freem(m);
2118 	return;
2119 }
2120 
2121 static const char *
2122 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2123 	struct in6_addr *tgt6)
2124 {
2125 	static char buf[1024];
2126 	snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2127 		ip6_sprintf(src6), ip6_sprintf(dst6), ip6_sprintf(tgt6));
2128 	return buf;
2129 }
2130 
2131 void
2132 icmp6_redirect_input(struct mbuf *m, int off)
2133 {
2134 	struct ifnet *ifp = m->m_pkthdr.rcvif;
2135 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2136 	struct nd_redirect *nd_rd;
2137 	int icmp6len = ntohs(ip6->ip6_plen);
2138 	char *lladdr = NULL;
2139 	int lladdrlen = 0;
2140 	struct rtentry *rt = NULL;
2141 	int is_router;
2142 	int is_onlink;
2143 	struct in6_addr src6 = ip6->ip6_src;
2144 	struct in6_addr redtgt6;
2145 	struct in6_addr reddst6;
2146 	union nd_opts ndopts;
2147 
2148 	if (!ifp)
2149 		return;
2150 
2151 	/* XXX if we are router, we don't update route by icmp6 redirect */
2152 	if (ip6_forwarding)
2153 		goto freeit;
2154 	if (!icmp6_rediraccept)
2155 		goto freeit;
2156 
2157 	IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2158 	if (nd_rd == NULL) {
2159 		ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
2160 		return;
2161 	}
2162 	redtgt6 = nd_rd->nd_rd_target;
2163 	reddst6 = nd_rd->nd_rd_dst;
2164 
2165 	if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2166 	    in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2167 		goto freeit;
2168 	}
2169 
2170 	/* validation */
2171 	if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2172 		nd6log((LOG_ERR,
2173 			"ICMP6 redirect sent from %s rejected; "
2174 			"must be from linklocal\n", ip6_sprintf(&src6)));
2175 		goto bad;
2176 	}
2177 	if (ip6->ip6_hlim != 255) {
2178 		nd6log((LOG_ERR,
2179 			"ICMP6 redirect sent from %s rejected; "
2180 			"hlim=%d (must be 255)\n",
2181 			ip6_sprintf(&src6), ip6->ip6_hlim));
2182 		goto bad;
2183 	}
2184     {
2185 	/* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2186 	struct sockaddr_in6 sin6;
2187 	struct in6_addr *gw6;
2188 
2189 	sockaddr_in6_init(&sin6, &reddst6, 0, 0, 0);
2190 	rt = rtalloc1((struct sockaddr *)&sin6, 0);
2191 	if (rt) {
2192 		if (rt->rt_gateway == NULL ||
2193 		    rt->rt_gateway->sa_family != AF_INET6) {
2194 			nd6log((LOG_ERR,
2195 			    "ICMP6 redirect rejected; no route "
2196 			    "with inet6 gateway found for redirect dst: %s\n",
2197 			    icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2198 			RTFREE(rt);
2199 			goto bad;
2200 		}
2201 
2202 		gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2203 		if (memcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2204 			nd6log((LOG_ERR,
2205 				"ICMP6 redirect rejected; "
2206 				"not equal to gw-for-src=%s (must be same): "
2207 				"%s\n",
2208 				ip6_sprintf(gw6),
2209 				icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2210 			RTFREE(rt);
2211 			goto bad;
2212 		}
2213 	} else {
2214 		nd6log((LOG_ERR,
2215 			"ICMP6 redirect rejected; "
2216 			"no route found for redirect dst: %s\n",
2217 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2218 		goto bad;
2219 	}
2220 	RTFREE(rt);
2221 	rt = NULL;
2222     }
2223 	if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2224 		nd6log((LOG_ERR,
2225 			"ICMP6 redirect rejected; "
2226 			"redirect dst must be unicast: %s\n",
2227 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2228 		goto bad;
2229 	}
2230 
2231 	is_router = is_onlink = 0;
2232 	if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2233 		is_router = 1;	/* router case */
2234 	if (memcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2235 		is_onlink = 1;	/* on-link destination case */
2236 	if (!is_router && !is_onlink) {
2237 		nd6log((LOG_ERR,
2238 			"ICMP6 redirect rejected; "
2239 			"neither router case nor onlink case: %s\n",
2240 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2241 		goto bad;
2242 	}
2243 	/* validation passed */
2244 
2245 	icmp6len -= sizeof(*nd_rd);
2246 	nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2247 	if (nd6_options(&ndopts) < 0) {
2248 		nd6log((LOG_INFO, "icmp6_redirect_input: "
2249 			"invalid ND option, rejected: %s\n",
2250 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2251 		/* nd6_options have incremented stats */
2252 		goto freeit;
2253 	}
2254 
2255 	if (ndopts.nd_opts_tgt_lladdr) {
2256 		lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2257 		lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2258 	}
2259 
2260 	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2261 		nd6log((LOG_INFO,
2262 			"icmp6_redirect_input: lladdrlen mismatch for %s "
2263 			"(if %d, icmp6 packet %d): %s\n",
2264 			ip6_sprintf(&redtgt6), ifp->if_addrlen, lladdrlen - 2,
2265 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2266 		goto bad;
2267 	}
2268 
2269 	/* RFC 2461 8.3 */
2270 	nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2271 			 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2272 
2273 	if (!is_onlink) {	/* better router case.  perform rtredirect. */
2274 		/* perform rtredirect */
2275 		struct sockaddr_in6 sdst;
2276 		struct sockaddr_in6 sgw;
2277 		struct sockaddr_in6 ssrc;
2278 		unsigned long rtcount;
2279 		struct rtentry *newrt = NULL;
2280 
2281 		/*
2282 		 * do not install redirect route, if the number of entries
2283 		 * is too much (> hiwat).  note that, the node (= host) will
2284 		 * work just fine even if we do not install redirect route
2285 		 * (there will be additional hops, though).
2286 		 */
2287 		rtcount = rt_timer_count(icmp6_redirect_timeout_q);
2288 		if (0 <= icmp6_redirect_hiwat && rtcount > icmp6_redirect_hiwat)
2289 			return;
2290 		else if (0 <= icmp6_redirect_lowat &&
2291 		    rtcount > icmp6_redirect_lowat) {
2292 			/*
2293 			 * XXX nuke a victim, install the new one.
2294 			 */
2295 		}
2296 
2297 		memset(&sdst, 0, sizeof(sdst));
2298 		memset(&sgw, 0, sizeof(sgw));
2299 		memset(&ssrc, 0, sizeof(ssrc));
2300 		sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2301 		sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2302 			sizeof(struct sockaddr_in6);
2303 		bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2304 		bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2305 		bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2306 		rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2307 			   (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
2308 			   (struct sockaddr *)&ssrc,
2309 			   &newrt);
2310 
2311 		if (newrt) {
2312 			(void)rt_timer_add(newrt, icmp6_redirect_timeout,
2313 			    icmp6_redirect_timeout_q);
2314 			rtfree(newrt);
2315 		}
2316 	}
2317 	/* finally update cached route in each socket via pfctlinput */
2318 	{
2319 		struct sockaddr_in6 sdst;
2320 
2321 		sockaddr_in6_init(&sdst, &reddst6, 0, 0, 0);
2322 		pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2323 #if defined(IPSEC) || defined(FAST_IPSEC)
2324 		key_sa_routechange((struct sockaddr *)&sdst);
2325 #endif
2326 	}
2327 
2328  freeit:
2329 	m_freem(m);
2330 	return;
2331 
2332  bad:
2333 	ICMP6_STATINC(ICMP6_STAT_BADREDIRECT);
2334 	m_freem(m);
2335 }
2336 
2337 void
2338 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2339 {
2340 	struct ifnet *ifp;	/* my outgoing interface */
2341 	struct in6_addr *ifp_ll6;
2342 	struct in6_addr *nexthop;
2343 	struct ip6_hdr *sip6;	/* m0 as struct ip6_hdr */
2344 	struct mbuf *m = NULL;	/* newly allocated one */
2345 	struct ip6_hdr *ip6;	/* m as struct ip6_hdr */
2346 	struct nd_redirect *nd_rd;
2347 	size_t maxlen;
2348 	u_char *p;
2349 	struct sockaddr_in6 src_sa;
2350 
2351 	icmp6_errcount(ICMP6_STAT_OUTERRHIST, ND_REDIRECT, 0);
2352 
2353 	/* if we are not router, we don't send icmp6 redirect */
2354 	if (!ip6_forwarding)
2355 		goto fail;
2356 
2357 	/* sanity check */
2358 	if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2359 		goto fail;
2360 
2361 	/*
2362 	 * Address check:
2363 	 *  the source address must identify a neighbor, and
2364 	 *  the destination address must not be a multicast address
2365 	 *  [RFC 2461, sec 8.2]
2366 	 */
2367 	sip6 = mtod(m0, struct ip6_hdr *);
2368 	sockaddr_in6_init(&src_sa, &sip6->ip6_src, 0, 0, 0);
2369 	if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2370 		goto fail;
2371 	if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2372 		goto fail;	/* what should we do here? */
2373 
2374 	/* rate limit */
2375 	if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2376 		goto fail;
2377 
2378 	/*
2379 	 * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2380 	 * we almost always ask for an mbuf cluster for simplicity.
2381 	 * (MHLEN < IPV6_MMTU is almost always true)
2382 	 */
2383 	MGETHDR(m, M_DONTWAIT, MT_HEADER);
2384 	if (m && IPV6_MMTU >= MHLEN) {
2385 #if IPV6_MMTU >= MCLBYTES
2386 		_MCLGET(m, mcl_cache, IPV6_MMTU, M_DONTWAIT);
2387 #else
2388 		MCLGET(m, M_DONTWAIT);
2389 #endif
2390 	}
2391 
2392 	if (!m)
2393 		goto fail;
2394 	m->m_pkthdr.rcvif = NULL;
2395 	m->m_len = 0;
2396 	maxlen = M_TRAILINGSPACE(m);
2397 	maxlen = min(IPV6_MMTU, maxlen);
2398 	/* just for safety */
2399 	if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2400 	    ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2401 		goto fail;
2402 	}
2403 
2404 	{
2405 		/* get ip6 linklocal address for ifp(my outgoing interface). */
2406 		struct in6_ifaddr *ia;
2407 		if ((ia = in6ifa_ifpforlinklocal(ifp,
2408 						 IN6_IFF_NOTREADY|
2409 						 IN6_IFF_ANYCAST)) == NULL)
2410 			goto fail;
2411 		ifp_ll6 = &ia->ia_addr.sin6_addr;
2412 	}
2413 
2414 	/* get ip6 linklocal address for the router. */
2415 	if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2416 		struct sockaddr_in6 *sin6;
2417 		sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2418 		nexthop = &sin6->sin6_addr;
2419 		if (!IN6_IS_ADDR_LINKLOCAL(nexthop))
2420 			nexthop = NULL;
2421 	} else
2422 		nexthop = NULL;
2423 
2424 	/* ip6 */
2425 	ip6 = mtod(m, struct ip6_hdr *);
2426 	ip6->ip6_flow = 0;
2427 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2428 	ip6->ip6_vfc |= IPV6_VERSION;
2429 	/* ip6->ip6_plen will be set later */
2430 	ip6->ip6_nxt = IPPROTO_ICMPV6;
2431 	ip6->ip6_hlim = 255;
2432 	/* ip6->ip6_src must be linklocal addr for my outgoing if. */
2433 	bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2434 	bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2435 
2436 	/* ND Redirect */
2437 	nd_rd = (struct nd_redirect *)(ip6 + 1);
2438 	nd_rd->nd_rd_type = ND_REDIRECT;
2439 	nd_rd->nd_rd_code = 0;
2440 	nd_rd->nd_rd_reserved = 0;
2441 	if (rt->rt_flags & RTF_GATEWAY) {
2442 		/*
2443 		 * nd_rd->nd_rd_target must be a link-local address in
2444 		 * better router cases.
2445 		 */
2446 		if (!nexthop)
2447 			goto fail;
2448 		bcopy(nexthop, &nd_rd->nd_rd_target,
2449 		      sizeof(nd_rd->nd_rd_target));
2450 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2451 		      sizeof(nd_rd->nd_rd_dst));
2452 	} else {
2453 		/* make sure redtgt == reddst */
2454 		nexthop = &sip6->ip6_dst;
2455 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2456 		      sizeof(nd_rd->nd_rd_target));
2457 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2458 		      sizeof(nd_rd->nd_rd_dst));
2459 	}
2460 
2461 	p = (u_char *)(nd_rd + 1);
2462 
2463 	{
2464 		/* target lladdr option */
2465 		struct rtentry *rt_nexthop = NULL;
2466 		int len;
2467 		const struct sockaddr_dl *sdl;
2468 		struct nd_opt_hdr *nd_opt;
2469 		char *lladdr;
2470 
2471 		rt_nexthop = nd6_lookup(nexthop, 0, ifp);
2472 		if (!rt_nexthop)
2473 			goto nolladdropt;
2474 		len = sizeof(*nd_opt) + ifp->if_addrlen;
2475 		len = (len + 7) & ~7;	/* round by 8 */
2476 		/* safety check */
2477 		if (len + (p - (u_char *)ip6) > maxlen)
2478 			goto nolladdropt;
2479 		if (!(rt_nexthop->rt_flags & RTF_GATEWAY) &&
2480 		    (rt_nexthop->rt_flags & RTF_LLINFO) &&
2481 		    (rt_nexthop->rt_gateway->sa_family == AF_LINK) &&
2482 		    (sdl = satocsdl(rt_nexthop->rt_gateway)) &&
2483 		    sdl->sdl_alen) {
2484 			nd_opt = (struct nd_opt_hdr *)p;
2485 			nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2486 			nd_opt->nd_opt_len = len >> 3;
2487 			lladdr = (char *)(nd_opt + 1);
2488 			memcpy(lladdr, CLLADDR(sdl), ifp->if_addrlen);
2489 			p += len;
2490 		}
2491 	}
2492   nolladdropt:;
2493 
2494 	m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2495 
2496 	/* just to be safe */
2497 	if (m0->m_flags & M_DECRYPTED)
2498 		goto noredhdropt;
2499 	if (p - (u_char *)ip6 > maxlen)
2500 		goto noredhdropt;
2501 
2502 	{
2503 		/* redirected header option */
2504 		int len;
2505 		struct nd_opt_rd_hdr *nd_opt_rh;
2506 
2507 		/*
2508 		 * compute the maximum size for icmp6 redirect header option.
2509 		 * XXX room for auth header?
2510 		 */
2511 		len = maxlen - (p - (u_char *)ip6);
2512 		len &= ~7;
2513 
2514 		/*
2515 		 * Redirected header option spec (RFC2461 4.6.3) talks nothing
2516 		 * about padding/truncate rule for the original IP packet.
2517 		 * From the discussion on IPv6imp in Feb 1999,
2518 		 * the consensus was:
2519 		 * - "attach as much as possible" is the goal
2520 		 * - pad if not aligned (original size can be guessed by
2521 		 *   original ip6 header)
2522 		 * Following code adds the padding if it is simple enough,
2523 		 * and truncates if not.
2524 		 */
2525 		if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2526 			/* not enough room, truncate */
2527 			m_adj(m0, (len - sizeof(*nd_opt_rh)) -
2528 			    m0->m_pkthdr.len);
2529 		} else {
2530 			/*
2531 			 * enough room, truncate if not aligned.
2532 			 * we don't pad here for simplicity.
2533 			 */
2534 			size_t extra;
2535 
2536 			extra = m0->m_pkthdr.len % 8;
2537 			if (extra) {
2538 				/* truncate */
2539 				m_adj(m0, -extra);
2540 			}
2541 			len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2542 		}
2543 
2544 		nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2545 		memset(nd_opt_rh, 0, sizeof(*nd_opt_rh));
2546 		nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2547 		nd_opt_rh->nd_opt_rh_len = len >> 3;
2548 		p += sizeof(*nd_opt_rh);
2549 		m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2550 
2551 		/* connect m0 to m */
2552 		m->m_pkthdr.len += m0->m_pkthdr.len;
2553 		m_cat(m, m0);
2554 		m0 = NULL;
2555 	}
2556 noredhdropt:
2557 	if (m0) {
2558 		m_freem(m0);
2559 		m0 = NULL;
2560 	}
2561 
2562 	/* XXX: clear embedded link IDs in the inner header */
2563 	in6_clearscope(&sip6->ip6_src);
2564 	in6_clearscope(&sip6->ip6_dst);
2565 	in6_clearscope(&nd_rd->nd_rd_target);
2566 	in6_clearscope(&nd_rd->nd_rd_dst);
2567 
2568 	ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2569 
2570 	nd_rd->nd_rd_cksum = 0;
2571 	nd_rd->nd_rd_cksum
2572 		= in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), ntohs(ip6->ip6_plen));
2573 
2574 	/* send the packet to outside... */
2575 	if (ip6_output(m, NULL, NULL, 0,
2576 		(struct ip6_moptions *)NULL, (struct socket *)NULL, NULL) != 0)
2577 		icmp6_ifstat_inc(ifp, ifs6_out_error);
2578 
2579 	icmp6_ifstat_inc(ifp, ifs6_out_msg);
2580 	icmp6_ifstat_inc(ifp, ifs6_out_redirect);
2581 	ICMP6_STATINC(ICMP6_STAT_OUTHIST + ND_REDIRECT);
2582 
2583 	return;
2584 
2585 fail:
2586 	if (m)
2587 		m_freem(m);
2588 	if (m0)
2589 		m_freem(m0);
2590 }
2591 
2592 /*
2593  * ICMPv6 socket option processing.
2594  */
2595 int
2596 icmp6_ctloutput(int op, struct socket *so, struct sockopt *sopt)
2597 {
2598 	int error = 0;
2599 	struct in6pcb *in6p = sotoin6pcb(so);
2600 
2601 	if (sopt->sopt_level != IPPROTO_ICMPV6)
2602 		return rip6_ctloutput(op, so, sopt);
2603 
2604 	switch (op) {
2605 	case PRCO_SETOPT:
2606 		switch (sopt->sopt_name) {
2607 		case ICMP6_FILTER:
2608 		    {
2609 			struct icmp6_filter fil;
2610 
2611 			error = sockopt_get(sopt, &fil, sizeof(fil));
2612 			if (error)
2613 				break;
2614 			memcpy(in6p->in6p_icmp6filt, &fil,
2615 			    sizeof(struct icmp6_filter));
2616 			error = 0;
2617 			break;
2618 		    }
2619 
2620 		default:
2621 			error = ENOPROTOOPT;
2622 			break;
2623 		}
2624 		break;
2625 
2626 	case PRCO_GETOPT:
2627 		switch (sopt->sopt_name) {
2628 		case ICMP6_FILTER:
2629 		    {
2630 			if (in6p->in6p_icmp6filt == NULL) {
2631 				error = EINVAL;
2632 				break;
2633 			}
2634 			error = sockopt_set(sopt, in6p->in6p_icmp6filt,
2635 			    sizeof(struct icmp6_filter));
2636 			break;
2637 		    }
2638 
2639 		default:
2640 			error = ENOPROTOOPT;
2641 			break;
2642 		}
2643 		break;
2644 	}
2645 
2646 	return (error);
2647 }
2648 
2649 /*
2650  * Perform rate limit check.
2651  * Returns 0 if it is okay to send the icmp6 packet.
2652  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2653  * limitation.
2654  *
2655  * XXX per-destination/type check necessary?
2656  */
2657 static int
2658 icmp6_ratelimit(
2659 	const struct in6_addr *dst,	/* not used at this moment */
2660 	const int type,		/* not used at this moment */
2661 	const int code)		/* not used at this moment */
2662 {
2663 	int ret;
2664 
2665 	ret = 0;	/* okay to send */
2666 
2667 	/* PPS limit */
2668 	if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count,
2669 	    icmp6errppslim)) {
2670 		/* The packet is subject to rate limit */
2671 		ret++;
2672 	}
2673 
2674 	return ret;
2675 }
2676 
2677 static struct rtentry *
2678 icmp6_mtudisc_clone(struct sockaddr *dst)
2679 {
2680 	struct rtentry *rt;
2681 	int    error;
2682 
2683 	rt = rtalloc1(dst, 1);
2684 	if (rt == 0)
2685 		return NULL;
2686 
2687 	/* If we didn't get a host route, allocate one */
2688 	if ((rt->rt_flags & RTF_HOST) == 0) {
2689 		struct rtentry *nrt;
2690 
2691 		error = rtrequest((int) RTM_ADD, dst,
2692 		    (struct sockaddr *) rt->rt_gateway,
2693 		    (struct sockaddr *) 0,
2694 		    RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt);
2695 		if (error) {
2696 			rtfree(rt);
2697 			return NULL;
2698 		}
2699 		nrt->rt_rmx = rt->rt_rmx;
2700 		rtfree(rt);
2701 		rt = nrt;
2702 	}
2703 	error = rt_timer_add(rt, icmp6_mtudisc_timeout,
2704 			icmp6_mtudisc_timeout_q);
2705 	if (error) {
2706 		rtfree(rt);
2707 		return NULL;
2708 	}
2709 
2710 	return rt;	/* caller need to call rtfree() */
2711 }
2712 
2713 static void
2714 icmp6_mtudisc_timeout(struct rtentry *rt, struct rttimer *r)
2715 {
2716 	if (rt == NULL)
2717 		panic("icmp6_mtudisc_timeout: bad route to timeout");
2718 	if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) ==
2719 	    (RTF_DYNAMIC | RTF_HOST)) {
2720 		rtrequest((int) RTM_DELETE, rt_getkey(rt),
2721 		    rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0);
2722 	} else {
2723 		if (!(rt->rt_rmx.rmx_locks & RTV_MTU))
2724 			rt->rt_rmx.rmx_mtu = 0;
2725 	}
2726 }
2727 
2728 static void
2729 icmp6_redirect_timeout(struct rtentry *rt, struct rttimer *r)
2730 {
2731 	if (rt == NULL)
2732 		panic("icmp6_redirect_timeout: bad route to timeout");
2733 	if ((rt->rt_flags & (RTF_GATEWAY | RTF_DYNAMIC | RTF_HOST)) ==
2734 	    (RTF_GATEWAY | RTF_DYNAMIC | RTF_HOST)) {
2735 		rtrequest((int) RTM_DELETE, rt_getkey(rt),
2736 		    rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0);
2737 	}
2738 }
2739 
2740 /*
2741  * sysctl helper routine for the net.inet6.icmp6.nd6 nodes.  silly?
2742  */
2743 static int
2744 sysctl_net_inet6_icmp6_nd6(SYSCTLFN_ARGS)
2745 {
2746 	(void)&name;
2747 	(void)&l;
2748 	(void)&oname;
2749 
2750 	if (namelen != 0)
2751 		return (EINVAL);
2752 
2753 	return (nd6_sysctl(rnode->sysctl_num, oldp, oldlenp,
2754 	    /*XXXUNCONST*/
2755 	    __UNCONST(newp), newlen));
2756 }
2757 
2758 static int
2759 sysctl_net_inet6_icmp6_stats(SYSCTLFN_ARGS)
2760 {
2761 
2762 	return (NETSTAT_SYSCTL(icmp6stat_percpu, ICMP6_NSTATS));
2763 }
2764 
2765 static void
2766 sysctl_net_inet6_icmp6_setup(struct sysctllog **clog)
2767 {
2768 	extern int nd6_maxqueuelen; /* defined in nd6.c */
2769 
2770 	sysctl_createv(clog, 0, NULL, NULL,
2771 		       CTLFLAG_PERMANENT,
2772 		       CTLTYPE_NODE, "net", NULL,
2773 		       NULL, 0, NULL, 0,
2774 		       CTL_NET, CTL_EOL);
2775 	sysctl_createv(clog, 0, NULL, NULL,
2776 		       CTLFLAG_PERMANENT,
2777 		       CTLTYPE_NODE, "inet6", NULL,
2778 		       NULL, 0, NULL, 0,
2779 		       CTL_NET, PF_INET6, CTL_EOL);
2780 	sysctl_createv(clog, 0, NULL, NULL,
2781 		       CTLFLAG_PERMANENT,
2782 		       CTLTYPE_NODE, "icmp6",
2783 		       SYSCTL_DESCR("ICMPv6 related settings"),
2784 		       NULL, 0, NULL, 0,
2785 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6, CTL_EOL);
2786 
2787 	sysctl_createv(clog, 0, NULL, NULL,
2788 		       CTLFLAG_PERMANENT,
2789 		       CTLTYPE_STRUCT, "stats",
2790 		       SYSCTL_DESCR("ICMPv6 transmission statistics"),
2791 		       sysctl_net_inet6_icmp6_stats, 0, NULL, 0,
2792 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2793 		       ICMPV6CTL_STATS, CTL_EOL);
2794 	sysctl_createv(clog, 0, NULL, NULL,
2795 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2796 		       CTLTYPE_INT, "rediraccept",
2797 		       SYSCTL_DESCR("Accept and process redirect messages"),
2798 		       NULL, 0, &icmp6_rediraccept, 0,
2799 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2800 		       ICMPV6CTL_REDIRACCEPT, CTL_EOL);
2801 	sysctl_createv(clog, 0, NULL, NULL,
2802 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2803 		       CTLTYPE_INT, "redirtimeout",
2804 		       SYSCTL_DESCR("Redirect generated route lifetime"),
2805 		       NULL, 0, &icmp6_redirtimeout, 0,
2806 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2807 		       ICMPV6CTL_REDIRTIMEOUT, CTL_EOL);
2808 #if 0 /* obsoleted */
2809 	sysctl_createv(clog, 0, NULL, NULL,
2810 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2811 		       CTLTYPE_INT, "errratelimit", NULL,
2812 		       NULL, 0, &icmp6_errratelimit, 0,
2813 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2814 		       ICMPV6CTL_ERRRATELIMIT, CTL_EOL);
2815 #endif
2816 	sysctl_createv(clog, 0, NULL, NULL,
2817 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2818 		       CTLTYPE_INT, "nd6_prune",
2819 		       SYSCTL_DESCR("Neighbor discovery prune interval"),
2820 		       NULL, 0, &nd6_prune, 0,
2821 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2822 		       ICMPV6CTL_ND6_PRUNE, CTL_EOL);
2823 	sysctl_createv(clog, 0, NULL, NULL,
2824 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2825 		       CTLTYPE_INT, "nd6_delay",
2826 		       SYSCTL_DESCR("First probe delay time"),
2827 		       NULL, 0, &nd6_delay, 0,
2828 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2829 		       ICMPV6CTL_ND6_DELAY, CTL_EOL);
2830 	sysctl_createv(clog, 0, NULL, NULL,
2831 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2832 		       CTLTYPE_INT, "nd6_umaxtries",
2833 		       SYSCTL_DESCR("Number of unicast discovery attempts"),
2834 		       NULL, 0, &nd6_umaxtries, 0,
2835 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2836 		       ICMPV6CTL_ND6_UMAXTRIES, CTL_EOL);
2837 	sysctl_createv(clog, 0, NULL, NULL,
2838 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2839 		       CTLTYPE_INT, "nd6_mmaxtries",
2840 		       SYSCTL_DESCR("Number of multicast discovery attempts"),
2841 		       NULL, 0, &nd6_mmaxtries, 0,
2842 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2843 		       ICMPV6CTL_ND6_MMAXTRIES, CTL_EOL);
2844 	sysctl_createv(clog, 0, NULL, NULL,
2845 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2846 		       CTLTYPE_INT, "nd6_useloopback",
2847 		       SYSCTL_DESCR("Use loopback interface for local traffic"),
2848 		       NULL, 0, &nd6_useloopback, 0,
2849 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2850 		       ICMPV6CTL_ND6_USELOOPBACK, CTL_EOL);
2851 #if 0 /* obsoleted */
2852 	sysctl_createv(clog, 0, NULL, NULL,
2853 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2854 		       CTLTYPE_INT, "nd6_proxyall", NULL,
2855 		       NULL, 0, &nd6_proxyall, 0,
2856 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2857 		       ICMPV6CTL_ND6_PROXYALL, CTL_EOL);
2858 #endif
2859 	sysctl_createv(clog, 0, NULL, NULL,
2860 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2861 		       CTLTYPE_INT, "nodeinfo",
2862 		       SYSCTL_DESCR("Respond to node information requests"),
2863 		       NULL, 0, &icmp6_nodeinfo, 0,
2864 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2865 		       ICMPV6CTL_NODEINFO, CTL_EOL);
2866 	sysctl_createv(clog, 0, NULL, NULL,
2867 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2868 		       CTLTYPE_INT, "errppslimit",
2869 		       SYSCTL_DESCR("Maximum ICMP errors sent per second"),
2870 		       NULL, 0, &icmp6errppslim, 0,
2871 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2872 		       ICMPV6CTL_ERRPPSLIMIT, CTL_EOL);
2873 	sysctl_createv(clog, 0, NULL, NULL,
2874 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2875 		       CTLTYPE_INT, "nd6_maxnudhint",
2876 		       SYSCTL_DESCR("Maximum neighbor unreachable hint count"),
2877 		       NULL, 0, &nd6_maxnudhint, 0,
2878 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2879 		       ICMPV6CTL_ND6_MAXNUDHINT, CTL_EOL);
2880 	sysctl_createv(clog, 0, NULL, NULL,
2881 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2882 		       CTLTYPE_INT, "mtudisc_hiwat",
2883 		       SYSCTL_DESCR("Low mark on MTU Discovery route timers"),
2884 		       NULL, 0, &icmp6_mtudisc_hiwat, 0,
2885 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2886 		       ICMPV6CTL_MTUDISC_HIWAT, CTL_EOL);
2887 	sysctl_createv(clog, 0, NULL, NULL,
2888 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2889 		       CTLTYPE_INT, "mtudisc_lowat",
2890 		       SYSCTL_DESCR("Low mark on MTU Discovery route timers"),
2891 		       NULL, 0, &icmp6_mtudisc_lowat, 0,
2892 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2893 		       ICMPV6CTL_MTUDISC_LOWAT, CTL_EOL);
2894 	sysctl_createv(clog, 0, NULL, NULL,
2895 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2896 		       CTLTYPE_INT, "nd6_debug",
2897 		       SYSCTL_DESCR("Enable neighbor discovery debug output"),
2898 		       NULL, 0, &nd6_debug, 0,
2899 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2900 		       ICMPV6CTL_ND6_DEBUG, CTL_EOL);
2901 	sysctl_createv(clog, 0, NULL, NULL,
2902 		       CTLFLAG_PERMANENT,
2903 		       CTLTYPE_STRUCT, "nd6_drlist",
2904 		       SYSCTL_DESCR("Default router list"),
2905 		       sysctl_net_inet6_icmp6_nd6, 0, NULL, 0,
2906 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2907 		       ICMPV6CTL_ND6_DRLIST, CTL_EOL);
2908 	sysctl_createv(clog, 0, NULL, NULL,
2909 		       CTLFLAG_PERMANENT,
2910 		       CTLTYPE_STRUCT, "nd6_prlist",
2911 		       SYSCTL_DESCR("Prefix list"),
2912 		       sysctl_net_inet6_icmp6_nd6, 0, NULL, 0,
2913 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2914 		       ICMPV6CTL_ND6_PRLIST, CTL_EOL);
2915 	sysctl_createv(clog, 0, NULL, NULL,
2916 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2917 		       CTLTYPE_INT, "maxqueuelen",
2918 		       SYSCTL_DESCR("max packet queue len for a unresolved ND"),
2919 		       NULL, 1, &nd6_maxqueuelen, 0,
2920 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2921 		       ICMPV6CTL_ND6_MAXQLEN, CTL_EOL);
2922 }
2923 
2924 void
2925 icmp6_statinc(u_int stat)
2926 {
2927 
2928 	KASSERT(stat < ICMP6_NSTATS);
2929 	ICMP6_STATINC(stat);
2930 }
2931