icmp6.c revision 1.112
1/*	$NetBSD: icmp6.c,v 1.112 2005/12/11 12:25:02 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 1.112 2005/12/11 12:25:02 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 <netinet/icmp6.h>
93#include <netinet6/mld6_var.h>
94#include <netinet6/in6_pcb.h>
95#include <netinet6/nd6.h>
96#include <netinet6/in6_ifattach.h>
97#include <netinet6/ip6protosw.h>
98
99#ifdef IPSEC
100#include <netinet6/ipsec.h>
101#include <netkey/key.h>
102#endif
103
104#include "faith.h"
105#if defined(NFAITH) && 0 < NFAITH
106#include <net/if_faith.h>
107#endif
108
109#include <net/net_osdep.h>
110
111extern struct domain inet6domain;
112
113struct icmp6stat icmp6stat;
114
115extern struct inpcbtable raw6cbtable;
116extern int icmp6errppslim;
117static int icmp6errpps_count = 0;
118static struct timeval icmp6errppslim_last;
119extern int icmp6_nodeinfo;
120
121/*
122 * List of callbacks to notify when Path MTU changes are made.
123 */
124struct icmp6_mtudisc_callback {
125	LIST_ENTRY(icmp6_mtudisc_callback) mc_list;
126	void (*mc_func) __P((struct in6_addr *));
127};
128
129LIST_HEAD(, icmp6_mtudisc_callback) icmp6_mtudisc_callbacks =
130    LIST_HEAD_INITIALIZER(&icmp6_mtudisc_callbacks);
131
132static struct rttimer_queue *icmp6_mtudisc_timeout_q = NULL;
133extern int pmtu_expire;
134
135/* XXX do these values make any sense? */
136static int icmp6_mtudisc_hiwat = 1280;
137static int icmp6_mtudisc_lowat = 256;
138
139/*
140 * keep track of # of redirect routes.
141 */
142static struct rttimer_queue *icmp6_redirect_timeout_q = NULL;
143
144/* XXX experimental, turned off */
145static int icmp6_redirect_hiwat = -1;
146static int icmp6_redirect_lowat = -1;
147
148static void icmp6_errcount __P((struct icmp6errstat *, int, int));
149static int icmp6_rip6_input __P((struct mbuf **, int));
150static int icmp6_ratelimit __P((const struct in6_addr *, const int, const int));
151static const char *icmp6_redirect_diag __P((struct in6_addr *,
152	struct in6_addr *, struct in6_addr *));
153static struct mbuf *ni6_input __P((struct mbuf *, int));
154static struct mbuf *ni6_nametodns __P((const char *, int, int));
155static int ni6_dnsmatch __P((const char *, int, const char *, int));
156static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *,
157			  struct ifnet **, char *));
158static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
159				struct ifnet *, int));
160static int icmp6_notify_error __P((struct mbuf *, int, int, int));
161static struct rtentry *icmp6_mtudisc_clone __P((struct sockaddr *));
162static void icmp6_mtudisc_timeout __P((struct rtentry *, struct rttimer *));
163static void icmp6_redirect_timeout __P((struct rtentry *, struct rttimer *));
164
165void
166icmp6_init()
167{
168	mld6_init();
169	icmp6_mtudisc_timeout_q = rt_timer_queue_create(pmtu_expire);
170	icmp6_redirect_timeout_q = rt_timer_queue_create(icmp6_redirtimeout);
171}
172
173static void
174icmp6_errcount(stat, type, code)
175	struct icmp6errstat *stat;
176	int type, code;
177{
178	switch (type) {
179	case ICMP6_DST_UNREACH:
180		switch (code) {
181		case ICMP6_DST_UNREACH_NOROUTE:
182			stat->icp6errs_dst_unreach_noroute++;
183			return;
184		case ICMP6_DST_UNREACH_ADMIN:
185			stat->icp6errs_dst_unreach_admin++;
186			return;
187		case ICMP6_DST_UNREACH_BEYONDSCOPE:
188			stat->icp6errs_dst_unreach_beyondscope++;
189			return;
190		case ICMP6_DST_UNREACH_ADDR:
191			stat->icp6errs_dst_unreach_addr++;
192			return;
193		case ICMP6_DST_UNREACH_NOPORT:
194			stat->icp6errs_dst_unreach_noport++;
195			return;
196		}
197		break;
198	case ICMP6_PACKET_TOO_BIG:
199		stat->icp6errs_packet_too_big++;
200		return;
201	case ICMP6_TIME_EXCEEDED:
202		switch (code) {
203		case ICMP6_TIME_EXCEED_TRANSIT:
204			stat->icp6errs_time_exceed_transit++;
205			return;
206		case ICMP6_TIME_EXCEED_REASSEMBLY:
207			stat->icp6errs_time_exceed_reassembly++;
208			return;
209		}
210		break;
211	case ICMP6_PARAM_PROB:
212		switch (code) {
213		case ICMP6_PARAMPROB_HEADER:
214			stat->icp6errs_paramprob_header++;
215			return;
216		case ICMP6_PARAMPROB_NEXTHEADER:
217			stat->icp6errs_paramprob_nextheader++;
218			return;
219		case ICMP6_PARAMPROB_OPTION:
220			stat->icp6errs_paramprob_option++;
221			return;
222		}
223		break;
224	case ND_REDIRECT:
225		stat->icp6errs_redirect++;
226		return;
227	}
228	stat->icp6errs_unknown++;
229}
230
231/*
232 * Register a Path MTU Discovery callback.
233 */
234void
235icmp6_mtudisc_callback_register(func)
236	void (*func) __P((struct in6_addr *));
237{
238	struct icmp6_mtudisc_callback *mc;
239
240	for (mc = LIST_FIRST(&icmp6_mtudisc_callbacks); mc != NULL;
241	     mc = LIST_NEXT(mc, mc_list)) {
242		if (mc->mc_func == func)
243			return;
244	}
245
246	mc = malloc(sizeof(*mc), M_PCB, M_NOWAIT);
247	if (mc == NULL)
248		panic("icmp6_mtudisc_callback_register");
249
250	mc->mc_func = func;
251	LIST_INSERT_HEAD(&icmp6_mtudisc_callbacks, mc, mc_list);
252}
253
254/*
255 * Generate an error packet of type error in response to bad IP6 packet.
256 */
257void
258icmp6_error(m, type, code, param)
259	struct mbuf *m;
260	int type, code, param;
261{
262	struct ip6_hdr *oip6, *nip6;
263	struct icmp6_hdr *icmp6;
264	u_int preplen;
265	int off;
266	int nxt;
267
268	icmp6stat.icp6s_error++;
269
270	/* count per-type-code statistics */
271	icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code);
272
273	if (m->m_flags & M_DECRYPTED) {
274		icmp6stat.icp6s_canterror++;
275		goto freeit;
276	}
277
278	if (m->m_len < sizeof(struct ip6_hdr)) {
279		m = m_pullup(m, sizeof(struct ip6_hdr));
280		if (m == NULL)
281			return;
282	}
283	oip6 = mtod(m, struct ip6_hdr *);
284
285	/*
286	 * If the destination address of the erroneous packet is a multicast
287	 * address, or the packet was sent using link-layer multicast,
288	 * we should basically suppress sending an error (RFC 2463, Section
289	 * 2.4).
290	 * We have two exceptions (the item e.2 in that section):
291	 * - the Pakcet Too Big message can be sent for path MTU discovery.
292	 * - the Parameter Problem Message that can be allowed an icmp6 error
293	 *   in the option type field.  This check has been done in
294	 *   ip6_unknown_opt(), so we can just check the type and code.
295	 */
296	if ((m->m_flags & (M_BCAST|M_MCAST) ||
297	     IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
298	    (type != ICMP6_PACKET_TOO_BIG &&
299	     (type != ICMP6_PARAM_PROB ||
300	      code != ICMP6_PARAMPROB_OPTION)))
301		goto freeit;
302
303	/*
304	 * RFC 2463, 2.4 (e.5): source address check.
305	 * XXX: the case of anycast source?
306	 */
307	if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
308	    IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
309		goto freeit;
310
311	/*
312	 * If we are about to send ICMPv6 against ICMPv6 error/redirect,
313	 * don't do it.
314	 */
315	nxt = -1;
316	off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
317	if (off >= 0 && nxt == IPPROTO_ICMPV6) {
318		struct icmp6_hdr *icp;
319
320		IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
321			sizeof(*icp));
322		if (icp == NULL) {
323			icmp6stat.icp6s_tooshort++;
324			return;
325		}
326		if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
327		    icp->icmp6_type == ND_REDIRECT) {
328			/*
329			 * ICMPv6 error
330			 * Special case: for redirect (which is
331			 * informational) we must not send icmp6 error.
332			 */
333			icmp6stat.icp6s_canterror++;
334			goto freeit;
335		} else {
336			/* ICMPv6 informational - send the error */
337		}
338	}
339#if 0 /* controversial */
340	else if (off >= 0 && nxt == IPPROTO_ESP) {
341		/*
342		 * It could be ICMPv6 error inside ESP.  Take a safer side,
343		 * don't respond.
344		 */
345		icmp6stat.icp6s_canterror++;
346		goto freeit;
347	}
348#endif
349	else {
350		/* non-ICMPv6 - send the error */
351	}
352
353	oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
354
355	/* Finally, do rate limitation check. */
356	if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
357		icmp6stat.icp6s_toofreq++;
358		goto freeit;
359	}
360
361	/*
362	 * OK, ICMP6 can be generated.
363	 */
364
365	if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
366		m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
367
368	preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
369	M_PREPEND(m, preplen, M_DONTWAIT);
370	if (m && m->m_len < preplen)
371		m = m_pullup(m, preplen);
372	if (m == NULL) {
373		nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
374		return;
375	}
376
377	nip6 = mtod(m, struct ip6_hdr *);
378	nip6->ip6_src  = oip6->ip6_src;
379	nip6->ip6_dst  = oip6->ip6_dst;
380
381	if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
382		oip6->ip6_src.s6_addr16[1] = 0;
383	if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
384		oip6->ip6_dst.s6_addr16[1] = 0;
385
386	icmp6 = (struct icmp6_hdr *)(nip6 + 1);
387	icmp6->icmp6_type = type;
388	icmp6->icmp6_code = code;
389	icmp6->icmp6_pptr = htonl((u_int32_t)param);
390
391	/*
392	 * icmp6_reflect() is designed to be in the input path.
393	 * icmp6_error() can be called from both input and outut path,
394	 * and if we are in output path rcvif could contain bogus value.
395	 * clear m->m_pkthdr.rcvif for safety, we should have enough scope
396	 * information in ip header (nip6).
397	 */
398	m->m_pkthdr.rcvif = NULL;
399
400	icmp6stat.icp6s_outhist[type]++;
401	icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
402
403	return;
404
405  freeit:
406	/*
407	 * If we can't tell wheter or not we can generate ICMP6, free it.
408	 */
409	m_freem(m);
410}
411
412/*
413 * Process a received ICMP6 message.
414 */
415int
416icmp6_input(mp, offp, proto)
417	struct mbuf **mp;
418	int *offp, proto;
419{
420	struct mbuf *m = *mp, *n;
421	struct ip6_hdr *ip6, *nip6;
422	struct icmp6_hdr *icmp6, *nicmp6;
423	int off = *offp;
424	int icmp6len = m->m_pkthdr.len - *offp;
425	int code, sum, noff;
426
427	icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg);
428
429	/*
430	 * Locate icmp6 structure in mbuf, and check
431	 * that not corrupted and of at least minimum length
432	 */
433
434	ip6 = mtod(m, struct ip6_hdr *);
435	if (icmp6len < sizeof(struct icmp6_hdr)) {
436		icmp6stat.icp6s_tooshort++;
437		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
438		goto freeit;
439	}
440
441	/*
442	 * calculate the checksum
443	 */
444	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
445	if (icmp6 == NULL) {
446		icmp6stat.icp6s_tooshort++;
447		/* m is invalid */
448		/*icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);*/
449		return IPPROTO_DONE;
450	}
451	KASSERT(IP6_HDR_ALIGNED_P(icmp6));
452	code = icmp6->icmp6_code;
453
454	if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
455		nd6log((LOG_ERR,
456		    "ICMP6 checksum error(%d|%x) %s\n",
457		    icmp6->icmp6_type, sum, ip6_sprintf(&ip6->ip6_src)));
458		icmp6stat.icp6s_checksum++;
459		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
460		goto freeit;
461	}
462
463#if defined(NFAITH) && 0 < NFAITH
464	if (faithprefix(&ip6->ip6_dst)) {
465		/*
466		 * Deliver very specific ICMP6 type only.
467		 * This is important to deilver TOOBIG.  Otherwise PMTUD
468		 * will not work.
469		 */
470		switch (icmp6->icmp6_type) {
471		case ICMP6_DST_UNREACH:
472		case ICMP6_PACKET_TOO_BIG:
473		case ICMP6_TIME_EXCEEDED:
474			break;
475		default:
476			goto freeit;
477		}
478	}
479#endif
480
481	icmp6stat.icp6s_inhist[icmp6->icmp6_type]++;
482
483	switch (icmp6->icmp6_type) {
484	case ICMP6_DST_UNREACH:
485		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach);
486		switch (code) {
487		case ICMP6_DST_UNREACH_NOROUTE:
488			code = PRC_UNREACH_NET;
489			break;
490		case ICMP6_DST_UNREACH_ADMIN:
491			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib);
492			code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
493			break;
494		case ICMP6_DST_UNREACH_ADDR:
495			code = PRC_HOSTDEAD;
496			break;
497#ifdef COMPAT_RFC1885
498		case ICMP6_DST_UNREACH_NOTNEIGHBOR:
499			code = PRC_UNREACH_SRCFAIL;
500			break;
501#else
502		case ICMP6_DST_UNREACH_BEYONDSCOPE:
503			/* I mean "source address was incorrect." */
504			code = PRC_UNREACH_NET;
505			break;
506#endif
507		case ICMP6_DST_UNREACH_NOPORT:
508			code = PRC_UNREACH_PORT;
509			break;
510		default:
511			goto badcode;
512		}
513		goto deliver;
514
515	case ICMP6_PACKET_TOO_BIG:
516		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig);
517
518		code = PRC_MSGSIZE;
519
520		/*
521		 * Updating the path MTU will be done after examining
522		 * intermediate extension headers.
523		 */
524		goto deliver;
525
526	case ICMP6_TIME_EXCEEDED:
527		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed);
528		switch (code) {
529		case ICMP6_TIME_EXCEED_TRANSIT:
530			code = PRC_TIMXCEED_INTRANS;
531			break;
532		case ICMP6_TIME_EXCEED_REASSEMBLY:
533			code = PRC_TIMXCEED_REASS;
534			break;
535		default:
536			goto badcode;
537		}
538		goto deliver;
539
540	case ICMP6_PARAM_PROB:
541		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob);
542		switch (code) {
543		case ICMP6_PARAMPROB_NEXTHEADER:
544			code = PRC_UNREACH_PROTOCOL;
545			break;
546		case ICMP6_PARAMPROB_HEADER:
547		case ICMP6_PARAMPROB_OPTION:
548			code = PRC_PARAMPROB;
549			break;
550		default:
551			goto badcode;
552		}
553		goto deliver;
554
555	case ICMP6_ECHO_REQUEST:
556		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo);
557		if (code != 0)
558			goto badcode;
559		/*
560		 * Copy mbuf to send to two data paths: userland socket(s),
561		 * and to the querier (echo reply).
562		 * m: a copy for socket, n: a copy for querier
563		 */
564		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
565			/* Give up local */
566			n = m;
567			m = NULL;
568			goto deliverecho;
569		}
570		/*
571		 * If the first mbuf is shared, or the first mbuf is too short,
572		 * copy the first part of the data into a fresh mbuf.
573		 * Otherwise, we will wrongly overwrite both copies.
574		 */
575		if ((n->m_flags & M_EXT) != 0 ||
576		    n->m_len < off + sizeof(struct icmp6_hdr)) {
577			struct mbuf *n0 = n;
578			const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
579
580			/*
581			 * Prepare an internal mbuf.  m_pullup() doesn't
582			 * always copy the length we specified.
583			 */
584			if (maxlen >= MCLBYTES) {
585				/* Give up remote */
586				m_freem(n0);
587				break;
588			}
589			MGETHDR(n, M_DONTWAIT, n0->m_type);
590			if (n && maxlen >= MHLEN) {
591				MCLGET(n, M_DONTWAIT);
592				if ((n->m_flags & M_EXT) == 0) {
593					m_free(n);
594					n = NULL;
595				}
596			}
597			if (n == NULL) {
598				/* Give up local */
599				m_freem(n0);
600				n = m;
601				m = NULL;
602				goto deliverecho;
603			}
604			M_MOVE_PKTHDR(n, n0);
605			/*
606			 * Copy IPv6 and ICMPv6 only.
607			 */
608			nip6 = mtod(n, struct ip6_hdr *);
609			bcopy(ip6, nip6, sizeof(struct ip6_hdr));
610			nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
611			bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
612			noff = sizeof(struct ip6_hdr);
613			n->m_len = noff + sizeof(struct icmp6_hdr);
614			/*
615			 * Adjust mbuf.  ip6_plen will be adjusted in
616			 * ip6_output().
617			 * n->m_pkthdr.len == n0->m_pkthdr.len at this point.
618			 */
619			n->m_pkthdr.len += noff + sizeof(struct icmp6_hdr);
620			n->m_pkthdr.len -= (off + sizeof(struct icmp6_hdr));
621			m_adj(n0, off + sizeof(struct icmp6_hdr));
622			n->m_next = n0;
623		} else {
624	 deliverecho:
625			nip6 = mtod(n, struct ip6_hdr *);
626			nicmp6 = (struct icmp6_hdr *)((caddr_t)nip6 + off);
627			noff = off;
628		}
629		nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
630		nicmp6->icmp6_code = 0;
631		if (n) {
632			icmp6stat.icp6s_reflect++;
633			icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++;
634			icmp6_reflect(n, noff);
635		}
636		if (!m)
637			goto freeit;
638		break;
639
640	case ICMP6_ECHO_REPLY:
641		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply);
642		if (code != 0)
643			goto badcode;
644		break;
645
646	case MLD_LISTENER_QUERY:
647	case MLD_LISTENER_REPORT:
648		if (icmp6len < sizeof(struct mld_hdr))
649			goto badlen;
650		if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */
651			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery);
652		else
653			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport);
654		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
655			/* give up local */
656			mld6_input(m, off);
657			m = NULL;
658			goto freeit;
659		}
660		mld6_input(n, off);
661		/* m stays. */
662		break;
663
664	case MLD_LISTENER_DONE:
665		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone);
666		if (icmp6len < sizeof(struct mld_hdr))	/* necessary? */
667			goto badlen;
668		break;		/* nothing to be done in kernel */
669
670	case MLD_MTRACE_RESP:
671	case MLD_MTRACE:
672		/* XXX: these two are experimental.  not officially defined. */
673		/* XXX: per-interface statistics? */
674		break;		/* just pass it to applications */
675
676	case ICMP6_WRUREQUEST:	/* ICMP6_FQDN_QUERY */
677	    {
678		enum { WRU, FQDN } mode;
679
680		if (!icmp6_nodeinfo)
681			break;
682
683		if (icmp6len == sizeof(struct icmp6_hdr) + 4)
684			mode = WRU;
685		else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
686			mode = FQDN;
687		else
688			goto badlen;
689
690		if (mode == FQDN) {
691			n = m_copym(m, 0, M_COPYALL, M_DONTWAIT);
692			if (n)
693				n = ni6_input(n, off);
694			/* XXX meaningless if n == NULL */
695			noff = sizeof(struct ip6_hdr);
696		} else {
697			u_char *p;
698			int maxlen, maxhlen;
699
700			if ((icmp6_nodeinfo & 5) != 5)
701				break;
702
703			if (code != 0)
704				goto badcode;
705			maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
706			if (maxlen >= MCLBYTES) {
707				/* Give up remote */
708				break;
709			}
710			MGETHDR(n, M_DONTWAIT, m->m_type);
711			if (n && maxlen > MHLEN) {
712				MCLGET(n, M_DONTWAIT);
713				if ((n->m_flags & M_EXT) == 0) {
714					m_free(n);
715					n = NULL;
716				}
717			}
718			if (n == NULL) {
719				/* Give up remote */
720				break;
721			}
722			n->m_pkthdr.rcvif = NULL;
723			n->m_len = 0;
724			maxhlen = M_TRAILINGSPACE(n) - maxlen;
725			if (maxhlen > hostnamelen)
726				maxhlen = hostnamelen;
727			/*
728			 * Copy IPv6 and ICMPv6 only.
729			 */
730			nip6 = mtod(n, struct ip6_hdr *);
731			bcopy(ip6, nip6, sizeof(struct ip6_hdr));
732			nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
733			bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
734			p = (u_char *)(nicmp6 + 1);
735			bzero(p, 4);
736			bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */
737			noff = sizeof(struct ip6_hdr);
738			M_COPY_PKTHDR(n, m); /* just for rcvif */
739			n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
740				sizeof(struct icmp6_hdr) + 4 + maxhlen;
741			nicmp6->icmp6_type = ICMP6_WRUREPLY;
742			nicmp6->icmp6_code = 0;
743		}
744#undef hostnamelen
745		if (n) {
746			icmp6stat.icp6s_reflect++;
747			icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++;
748			icmp6_reflect(n, noff);
749		}
750		break;
751	    }
752
753	case ICMP6_WRUREPLY:
754		if (code != 0)
755			goto badcode;
756		break;
757
758	case ND_ROUTER_SOLICIT:
759		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit);
760		if (code != 0)
761			goto badcode;
762		if (icmp6len < sizeof(struct nd_router_solicit))
763			goto badlen;
764		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
765			/* give up local */
766			nd6_rs_input(m, off, icmp6len);
767			m = NULL;
768			goto freeit;
769		}
770		nd6_rs_input(n, off, icmp6len);
771		/* m stays. */
772		break;
773
774	case ND_ROUTER_ADVERT:
775		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert);
776		if (code != 0)
777			goto badcode;
778		if (icmp6len < sizeof(struct nd_router_advert))
779			goto badlen;
780		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
781			/* give up local */
782			nd6_ra_input(m, off, icmp6len);
783			m = NULL;
784			goto freeit;
785		}
786		nd6_ra_input(n, off, icmp6len);
787		/* m stays. */
788		break;
789
790	case ND_NEIGHBOR_SOLICIT:
791		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit);
792		if (code != 0)
793			goto badcode;
794		if (icmp6len < sizeof(struct nd_neighbor_solicit))
795			goto badlen;
796		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
797			/* give up local */
798			nd6_ns_input(m, off, icmp6len);
799			m = NULL;
800			goto freeit;
801		}
802		nd6_ns_input(n, off, icmp6len);
803		/* m stays. */
804		break;
805
806	case ND_NEIGHBOR_ADVERT:
807		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert);
808		if (code != 0)
809			goto badcode;
810		if (icmp6len < sizeof(struct nd_neighbor_advert))
811			goto badlen;
812		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
813			/* give up local */
814			nd6_na_input(m, off, icmp6len);
815			m = NULL;
816			goto freeit;
817		}
818		nd6_na_input(n, off, icmp6len);
819		/* m stays. */
820		break;
821
822	case ND_REDIRECT:
823		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect);
824		if (code != 0)
825			goto badcode;
826		if (icmp6len < sizeof(struct nd_redirect))
827			goto badlen;
828		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
829			/* give up local */
830			icmp6_redirect_input(m, off);
831			m = NULL;
832			goto freeit;
833		}
834		icmp6_redirect_input(n, off);
835		/* m stays. */
836		break;
837
838	case ICMP6_ROUTER_RENUMBERING:
839		if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
840		    code != ICMP6_ROUTER_RENUMBERING_RESULT)
841			goto badcode;
842		if (icmp6len < sizeof(struct icmp6_router_renum))
843			goto badlen;
844		break;
845
846	default:
847		nd6log((LOG_DEBUG,
848		    "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
849		    icmp6->icmp6_type, ip6_sprintf(&ip6->ip6_src),
850		    ip6_sprintf(&ip6->ip6_dst),
851		    m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0));
852		if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
853			/* ICMPv6 error: MUST deliver it by spec... */
854			code = PRC_NCMDS;
855			/* deliver */
856		} else {
857			/* ICMPv6 informational: MUST not deliver */
858			break;
859		}
860	deliver:
861		if (icmp6_notify_error(m, off, icmp6len, code)) {
862			/* In this case, m should've been freed. */
863			return (IPPROTO_DONE);
864		}
865		break;
866
867	badcode:
868		icmp6stat.icp6s_badcode++;
869		break;
870
871	badlen:
872		icmp6stat.icp6s_badlen++;
873		break;
874	}
875
876	/* deliver the packet to appropriate sockets */
877	icmp6_rip6_input(&m, *offp);
878
879	return IPPROTO_DONE;
880
881 freeit:
882	m_freem(m);
883	return IPPROTO_DONE;
884}
885
886static int
887icmp6_notify_error(m, off, icmp6len, code)
888	struct mbuf *m;
889	int off, icmp6len;
890{
891	struct icmp6_hdr *icmp6;
892	struct ip6_hdr *eip6;
893	u_int32_t notifymtu;
894	struct sockaddr_in6 icmp6src, icmp6dst;
895
896	if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
897		icmp6stat.icp6s_tooshort++;
898		goto freeit;
899	}
900	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
901		       sizeof(*icmp6) + sizeof(struct ip6_hdr));
902	if (icmp6 == NULL) {
903		icmp6stat.icp6s_tooshort++;
904		return (-1);
905	}
906	eip6 = (struct ip6_hdr *)(icmp6 + 1);
907
908	/* Detect the upper level protocol */
909	{
910		void (*ctlfunc) __P((int, struct sockaddr *, void *));
911		u_int8_t nxt = eip6->ip6_nxt;
912		int eoff = off + sizeof(struct icmp6_hdr) +
913			sizeof(struct ip6_hdr);
914		struct ip6ctlparam ip6cp;
915		struct in6_addr *finaldst = NULL;
916		int icmp6type = icmp6->icmp6_type;
917		struct ip6_frag *fh;
918		struct ip6_rthdr *rth;
919		struct ip6_rthdr0 *rth0;
920		int rthlen;
921
922		while (1) { /* XXX: should avoid infinite loop explicitly? */
923			struct ip6_ext *eh;
924
925			switch (nxt) {
926			case IPPROTO_HOPOPTS:
927			case IPPROTO_DSTOPTS:
928			case IPPROTO_AH:
929				IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
930					       eoff, sizeof(*eh));
931				if (eh == NULL) {
932					icmp6stat.icp6s_tooshort++;
933					return (-1);
934				}
935
936				if (nxt == IPPROTO_AH)
937					eoff += (eh->ip6e_len + 2) << 2;
938				else
939					eoff += (eh->ip6e_len + 1) << 3;
940				nxt = eh->ip6e_nxt;
941				break;
942			case IPPROTO_ROUTING:
943				/*
944				 * When the erroneous packet contains a
945				 * routing header, we should examine the
946				 * header to determine the final destination.
947				 * Otherwise, we can't properly update
948				 * information that depends on the final
949				 * destination (e.g. path MTU).
950				 */
951				IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
952					       eoff, sizeof(*rth));
953				if (rth == NULL) {
954					icmp6stat.icp6s_tooshort++;
955					return (-1);
956				}
957				rthlen = (rth->ip6r_len + 1) << 3;
958				/*
959				 * XXX: currently there is no
960				 * officially defined type other
961				 * than type-0.
962				 * Note that if the segment left field
963				 * is 0, all intermediate hops must
964				 * have been passed.
965				 */
966				if (rth->ip6r_segleft &&
967				    rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
968					int hops;
969
970					IP6_EXTHDR_GET(rth0,
971						       struct ip6_rthdr0 *, m,
972						       eoff, rthlen);
973					if (rth0 == NULL) {
974						icmp6stat.icp6s_tooshort++;
975						return (-1);
976					}
977					/* just ignore a bogus header */
978					if ((rth0->ip6r0_len % 2) == 0 &&
979					    (hops = rth0->ip6r0_len/2))
980						finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
981				}
982				eoff += rthlen;
983				nxt = rth->ip6r_nxt;
984				break;
985			case IPPROTO_FRAGMENT:
986				IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
987					       eoff, sizeof(*fh));
988				if (fh == NULL) {
989					icmp6stat.icp6s_tooshort++;
990					return (-1);
991				}
992				/*
993				 * Data after a fragment header is meaningless
994				 * unless it is the first fragment, but
995				 * we'll go to the notify label for path MTU
996				 * discovery.
997				 */
998				if (fh->ip6f_offlg & IP6F_OFF_MASK)
999					goto notify;
1000
1001				eoff += sizeof(struct ip6_frag);
1002				nxt = fh->ip6f_nxt;
1003				break;
1004			default:
1005				/*
1006				 * This case includes ESP and the No Next
1007				 * Header.  In such cases going to the notify
1008				 * label does not have any meaning
1009				 * (i.e. ctlfunc will be NULL), but we go
1010				 * anyway since we might have to update
1011				 * path MTU information.
1012				 */
1013				goto notify;
1014			}
1015		}
1016	  notify:
1017		IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1018			       sizeof(*icmp6) + sizeof(struct ip6_hdr));
1019		if (icmp6 == NULL) {
1020			icmp6stat.icp6s_tooshort++;
1021			return (-1);
1022		}
1023
1024		eip6 = (struct ip6_hdr *)(icmp6 + 1);
1025		bzero(&icmp6dst, sizeof(icmp6dst));
1026		icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1027		icmp6dst.sin6_family = AF_INET6;
1028		if (finaldst == NULL)
1029			icmp6dst.sin6_addr = eip6->ip6_dst;
1030		else
1031			icmp6dst.sin6_addr = *finaldst;
1032		icmp6dst.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
1033							  &icmp6dst.sin6_addr);
1034#ifndef SCOPEDROUTING
1035		if (in6_embedscope(&icmp6dst.sin6_addr, &icmp6dst,
1036				   NULL, NULL)) {
1037			/* should be impossbile */
1038			nd6log((LOG_DEBUG,
1039			    "icmp6_notify_error: in6_embedscope failed\n"));
1040			goto freeit;
1041		}
1042#endif
1043
1044		/*
1045		 * retrieve parameters from the inner IPv6 header, and convert
1046		 * them into sockaddr structures.
1047		 */
1048		bzero(&icmp6src, sizeof(icmp6src));
1049		icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1050		icmp6src.sin6_family = AF_INET6;
1051		icmp6src.sin6_addr = eip6->ip6_src;
1052		icmp6src.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
1053							  &icmp6src.sin6_addr);
1054#ifndef SCOPEDROUTING
1055		if (in6_embedscope(&icmp6src.sin6_addr, &icmp6src,
1056				   NULL, NULL)) {
1057			/* should be impossbile */
1058			nd6log((LOG_DEBUG,
1059			    "icmp6_notify_error: in6_embedscope failed\n"));
1060			goto freeit;
1061		}
1062#endif
1063		icmp6src.sin6_flowinfo =
1064			(eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1065
1066		if (finaldst == NULL)
1067			finaldst = &eip6->ip6_dst;
1068		ip6cp.ip6c_m = m;
1069		ip6cp.ip6c_icmp6 = icmp6;
1070		ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1071		ip6cp.ip6c_off = eoff;
1072		ip6cp.ip6c_finaldst = finaldst;
1073		ip6cp.ip6c_src = &icmp6src;
1074		ip6cp.ip6c_nxt = nxt;
1075
1076		if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1077			notifymtu = ntohl(icmp6->icmp6_mtu);
1078			ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1079		}
1080
1081		ctlfunc = (void (*) __P((int, struct sockaddr *, void *)))
1082			(inet6sw[ip6_protox[nxt]].pr_ctlinput);
1083		if (ctlfunc) {
1084			(void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1085					  &ip6cp);
1086		}
1087	}
1088	return (0);
1089
1090  freeit:
1091	m_freem(m);
1092	return (-1);
1093}
1094
1095void
1096icmp6_mtudisc_update(ip6cp, validated)
1097	struct ip6ctlparam *ip6cp;
1098	int validated;
1099{
1100	unsigned long rtcount;
1101	struct icmp6_mtudisc_callback *mc;
1102	struct in6_addr *dst = ip6cp->ip6c_finaldst;
1103	struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1104	struct mbuf *m = ip6cp->ip6c_m;	/* will be necessary for scope issue */
1105	u_int mtu = ntohl(icmp6->icmp6_mtu);
1106	struct rtentry *rt = NULL;
1107	struct sockaddr_in6 sin6;
1108
1109	/*
1110	 * allow non-validated cases if memory is plenty, to make traffic
1111	 * from non-connected pcb happy.
1112	 */
1113	rtcount = rt_timer_count(icmp6_mtudisc_timeout_q);
1114	if (validated) {
1115		if (0 <= icmp6_mtudisc_hiwat && rtcount > icmp6_mtudisc_hiwat)
1116			return;
1117		else if (0 <= icmp6_mtudisc_lowat &&
1118		    rtcount > icmp6_mtudisc_lowat) {
1119			/*
1120			 * XXX nuke a victim, install the new one.
1121			 */
1122		}
1123	} else {
1124		if (0 <= icmp6_mtudisc_lowat && rtcount > icmp6_mtudisc_lowat)
1125			return;
1126	}
1127
1128	bzero(&sin6, sizeof(sin6));
1129	sin6.sin6_family = PF_INET6;
1130	sin6.sin6_len = sizeof(struct sockaddr_in6);
1131	sin6.sin6_addr = *dst;
1132	/* XXX normally, this won't happen */
1133	if (IN6_IS_ADDR_LINKLOCAL(dst)) {
1134		sin6.sin6_addr.s6_addr16[1] =
1135		    htons(m->m_pkthdr.rcvif->if_index);
1136	}
1137	/* sin6.sin6_scope_id = XXX: should be set if DST is a scoped addr */
1138	rt = icmp6_mtudisc_clone((struct sockaddr *)&sin6);
1139
1140	if (rt && (rt->rt_flags & RTF_HOST) &&
1141	    !(rt->rt_rmx.rmx_locks & RTV_MTU) &&
1142	    (rt->rt_rmx.rmx_mtu > mtu || rt->rt_rmx.rmx_mtu == 0)) {
1143		if (mtu < IN6_LINKMTU(rt->rt_ifp)) {
1144			icmp6stat.icp6s_pmtuchg++;
1145			rt->rt_rmx.rmx_mtu = mtu;
1146		}
1147	}
1148	if (rt) { /* XXX: need braces to avoid conflict with else in RTFREE. */
1149		RTFREE(rt);
1150	}
1151
1152	/*
1153	 * Notify protocols that the MTU for this destination
1154	 * has changed.
1155	 */
1156	for (mc = LIST_FIRST(&icmp6_mtudisc_callbacks); mc != NULL;
1157	     mc = LIST_NEXT(mc, mc_list))
1158		(*mc->mc_func)(&sin6.sin6_addr);
1159}
1160
1161/*
1162 * Process a Node Information Query packet, based on
1163 * draft-ietf-ipngwg-icmp-name-lookups-07.
1164 *
1165 * Spec incompatibilities:
1166 * - IPv6 Subject address handling
1167 * - IPv4 Subject address handling support missing
1168 * - Proxy reply (answer even if it's not for me)
1169 * - joins NI group address at in6_ifattach() time only, does not cope
1170 *   with hostname changes by sethostname(3)
1171 */
1172#ifndef offsetof		/* XXX */
1173#define	offsetof(type, member)	((size_t)(&((type *)0)->member))
1174#endif
1175static struct mbuf *
1176ni6_input(m, off)
1177	struct mbuf *m;
1178	int off;
1179{
1180	struct icmp6_nodeinfo *ni6, *nni6;
1181	struct mbuf *n = NULL;
1182	u_int16_t qtype;
1183	int subjlen;
1184	int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1185	struct ni_reply_fqdn *fqdn;
1186	int addrs;		/* for NI_QTYPE_NODEADDR */
1187	struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1188	struct sockaddr_in6 sin6; /* double meaning; ip6_dst and subjectaddr */
1189	struct ip6_hdr *ip6;
1190	int oldfqdn = 0;	/* if 1, return pascal string (03 draft) */
1191	char *subj = NULL;
1192
1193	ip6 = mtod(m, struct ip6_hdr *);
1194	IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1195	if (ni6 == NULL) {
1196		/* m is already reclaimed */
1197		return NULL;
1198	}
1199
1200	/*
1201	 * Validate IPv6 destination address.
1202	 *
1203	 * The Responder must discard the Query without further processing
1204	 * unless it is one of the Responder's unicast or anycast addresses, or
1205	 * a link-local scope multicast address which the Responder has joined.
1206	 * [icmp-name-lookups-07, Section 4.]
1207	 */
1208	bzero(&sin6, sizeof(sin6));
1209	sin6.sin6_family = AF_INET6;
1210	sin6.sin6_len = sizeof(struct sockaddr_in6);
1211	bcopy(&ip6->ip6_dst, &sin6.sin6_addr, sizeof(sin6.sin6_addr));
1212	/* XXX scopeid */
1213	if (ifa_ifwithaddr((struct sockaddr *)&sin6))
1214		; /* unicast/anycast, fine */
1215	else if (IN6_IS_ADDR_MC_LINKLOCAL(&sin6.sin6_addr))
1216		; /* link-local multicast, fine */
1217	else
1218		goto bad;
1219
1220	/* validate query Subject field. */
1221	qtype = ntohs(ni6->ni_qtype);
1222	subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1223	switch (qtype) {
1224	case NI_QTYPE_NOOP:
1225	case NI_QTYPE_SUPTYPES:
1226		/* 07 draft */
1227		if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1228			break;
1229		/* FALLTHROUGH */
1230	case NI_QTYPE_FQDN:
1231	case NI_QTYPE_NODEADDR:
1232		switch (ni6->ni_code) {
1233		case ICMP6_NI_SUBJ_IPV6:
1234#if ICMP6_NI_SUBJ_IPV6 != 0
1235		case 0:
1236#endif
1237			/*
1238			 * backward compatibility - try to accept 03 draft
1239			 * format, where no Subject is present.
1240			 */
1241			if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1242			    subjlen == 0) {
1243				oldfqdn++;
1244				break;
1245			}
1246#if ICMP6_NI_SUBJ_IPV6 != 0
1247			if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1248				goto bad;
1249#endif
1250
1251			if (subjlen != sizeof(sin6.sin6_addr))
1252				goto bad;
1253
1254			/*
1255			 * Validate Subject address.
1256			 *
1257			 * Not sure what exactly "address belongs to the node"
1258			 * means in the spec, is it just unicast, or what?
1259			 *
1260			 * At this moment we consider Subject address as
1261			 * "belong to the node" if the Subject address equals
1262			 * to the IPv6 destination address; validation for
1263			 * IPv6 destination address should have done enough
1264			 * check for us.
1265			 *
1266			 * We do not do proxy at this moment.
1267			 */
1268			/* m_pulldown instead of copy? */
1269			m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1270			    subjlen, (caddr_t)&sin6.sin6_addr);
1271			/* XXX kame scope hack */
1272			if (IN6_IS_SCOPE_LINKLOCAL(&sin6.sin6_addr)) {
1273				if ((m->m_flags & M_PKTHDR) != 0 &&
1274				    m->m_pkthdr.rcvif) {
1275					sin6.sin6_addr.s6_addr16[1] =
1276					    htons(m->m_pkthdr.rcvif->if_index);
1277				}
1278			}
1279			subj = (char *)&sin6;
1280			if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &sin6.sin6_addr))
1281				break;
1282
1283			/*
1284			 * XXX if we are to allow other cases, we should really
1285			 * be careful about scope here.
1286			 * basically, we should disallow queries toward IPv6
1287			 * destination X with subject Y, if scope(X) > scope(Y).
1288			 * if we allow scope(X) > scope(Y), it will result in
1289			 * information leakage across scope boundary.
1290			 */
1291			goto bad;
1292
1293		case ICMP6_NI_SUBJ_FQDN:
1294			/*
1295			 * Validate Subject name with gethostname(3).
1296			 *
1297			 * The behavior may need some debate, since:
1298			 * - we are not sure if the node has FQDN as
1299			 *   hostname (returned by gethostname(3)).
1300			 * - the code does wildcard match for truncated names.
1301			 *   however, we are not sure if we want to perform
1302			 *   wildcard match, if gethostname(3) side has
1303			 *   truncated hostname.
1304			 */
1305			n = ni6_nametodns(hostname, hostnamelen, 0);
1306			if (!n || n->m_next || n->m_len == 0)
1307				goto bad;
1308			IP6_EXTHDR_GET(subj, char *, m,
1309			    off + sizeof(struct icmp6_nodeinfo), subjlen);
1310			if (subj == NULL)
1311				goto bad;
1312			if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1313					n->m_len)) {
1314				goto bad;
1315			}
1316			m_freem(n);
1317			n = NULL;
1318			break;
1319
1320		case ICMP6_NI_SUBJ_IPV4:	/* XXX: to be implemented? */
1321		default:
1322			goto bad;
1323		}
1324		break;
1325	}
1326
1327	/* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1328	switch (qtype) {
1329	case NI_QTYPE_FQDN:
1330		if ((icmp6_nodeinfo & 1) == 0)
1331			goto bad;
1332		break;
1333	case NI_QTYPE_NODEADDR:
1334		if ((icmp6_nodeinfo & 2) == 0)
1335			goto bad;
1336		break;
1337	}
1338
1339	/* guess reply length */
1340	switch (qtype) {
1341	case NI_QTYPE_NOOP:
1342		break;		/* no reply data */
1343	case NI_QTYPE_SUPTYPES:
1344		replylen += sizeof(u_int32_t);
1345		break;
1346	case NI_QTYPE_FQDN:
1347		/* XXX will append an mbuf */
1348		replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1349		break;
1350	case NI_QTYPE_NODEADDR:
1351		addrs = ni6_addrs(ni6, m, &ifp, subj);
1352		if ((replylen += addrs * (sizeof(struct in6_addr) +
1353					  sizeof(u_int32_t))) > MCLBYTES)
1354			replylen = MCLBYTES; /* XXX: will truncate pkt later */
1355		break;
1356	default:
1357		/*
1358		 * XXX: We must return a reply with the ICMP6 code
1359		 * `unknown Qtype' in this case.  However we regard the case
1360		 * as an FQDN query for backward compatibility.
1361		 * Older versions set a random value to this field,
1362		 * so it rarely varies in the defined qtypes.
1363		 * But the mechanism is not reliable...
1364		 * maybe we should obsolete older versions.
1365		 */
1366		qtype = NI_QTYPE_FQDN;
1367		/* XXX will append an mbuf */
1368		replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1369		oldfqdn++;
1370		break;
1371	}
1372
1373	/* allocate an mbuf to reply. */
1374	MGETHDR(n, M_DONTWAIT, m->m_type);
1375	if (n == NULL) {
1376		m_freem(m);
1377		return (NULL);
1378	}
1379	M_MOVE_PKTHDR(n, m); /* just for rcvif */
1380	if (replylen > MHLEN) {
1381		if (replylen > MCLBYTES) {
1382			/*
1383			 * XXX: should we try to allocate more? But MCLBYTES
1384			 * is probably much larger than IPV6_MMTU...
1385			 */
1386			goto bad;
1387		}
1388		MCLGET(n, M_DONTWAIT);
1389		if ((n->m_flags & M_EXT) == 0) {
1390			goto bad;
1391		}
1392	}
1393	n->m_pkthdr.len = n->m_len = replylen;
1394
1395	/* copy mbuf header and IPv6 + Node Information base headers */
1396	bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1397	nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1398	bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1399
1400	/* qtype dependent procedure */
1401	switch (qtype) {
1402	case NI_QTYPE_NOOP:
1403		nni6->ni_code = ICMP6_NI_SUCCESS;
1404		nni6->ni_flags = 0;
1405		break;
1406	case NI_QTYPE_SUPTYPES:
1407	{
1408		u_int32_t v;
1409		nni6->ni_code = ICMP6_NI_SUCCESS;
1410		nni6->ni_flags = htons(0x0000);	/* raw bitmap */
1411		/* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1412		v = (u_int32_t)htonl(0x0000000f);
1413		bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1414		break;
1415	}
1416	case NI_QTYPE_FQDN:
1417		nni6->ni_code = ICMP6_NI_SUCCESS;
1418		fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1419						sizeof(struct ip6_hdr) +
1420						sizeof(struct icmp6_nodeinfo));
1421		nni6->ni_flags = 0; /* XXX: meaningless TTL */
1422		fqdn->ni_fqdn_ttl = 0;	/* ditto. */
1423		/*
1424		 * XXX do we really have FQDN in variable "hostname"?
1425		 */
1426		n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn);
1427		if (n->m_next == NULL)
1428			goto bad;
1429		/* XXX we assume that n->m_next is not a chain */
1430		if (n->m_next->m_next != NULL)
1431			goto bad;
1432		n->m_pkthdr.len += n->m_next->m_len;
1433		break;
1434	case NI_QTYPE_NODEADDR:
1435	{
1436		int lenlim, copied;
1437
1438		nni6->ni_code = ICMP6_NI_SUCCESS;
1439		n->m_pkthdr.len = n->m_len =
1440		    sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1441		lenlim = M_TRAILINGSPACE(n);
1442		copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1443		/* XXX: reset mbuf length */
1444		n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1445			sizeof(struct icmp6_nodeinfo) + copied;
1446		break;
1447	}
1448	default:
1449		break;		/* XXX impossible! */
1450	}
1451
1452	nni6->ni_type = ICMP6_NI_REPLY;
1453	m_freem(m);
1454	return (n);
1455
1456  bad:
1457	m_freem(m);
1458	if (n)
1459		m_freem(n);
1460	return (NULL);
1461}
1462#undef hostnamelen
1463
1464#define isupper(x) ('A' <= (x) && (x) <= 'Z')
1465#define isalpha(x) (('A' <= (x) && (x) <= 'Z') || ('a' <= (x) && (x) <= 'z'))
1466#define isalnum(x) (isalpha(x) || ('0' <= (x) && (x) <= '9'))
1467#define tolower(x) (isupper(x) ? (x) + 'a' - 'A' : (x))
1468
1469/*
1470 * make a mbuf with DNS-encoded string.  no compression support.
1471 *
1472 * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1473 * treated as truncated name (two \0 at the end).  this is a wild guess.
1474 */
1475static struct mbuf *
1476ni6_nametodns(name, namelen, old)
1477	const char *name;
1478	int namelen;
1479	int old;	/* return pascal string if non-zero */
1480{
1481	struct mbuf *m;
1482	char *cp, *ep;
1483	const char *p, *q;
1484	int i, len, nterm;
1485
1486	if (old)
1487		len = namelen + 1;
1488	else
1489		len = MCLBYTES;
1490
1491	/* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1492	MGET(m, M_DONTWAIT, MT_DATA);
1493	if (m && len > MLEN) {
1494		MCLGET(m, M_DONTWAIT);
1495		if ((m->m_flags & M_EXT) == 0)
1496			goto fail;
1497	}
1498	if (!m)
1499		goto fail;
1500	m->m_next = NULL;
1501
1502	if (old) {
1503		m->m_len = len;
1504		*mtod(m, char *) = namelen;
1505		bcopy(name, mtod(m, char *) + 1, namelen);
1506		return m;
1507	} else {
1508		m->m_len = 0;
1509		cp = mtod(m, char *);
1510		ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1511
1512		/* if not certain about my name, return empty buffer */
1513		if (namelen == 0)
1514			return m;
1515
1516		/*
1517		 * guess if it looks like shortened hostname, or FQDN.
1518		 * shortened hostname needs two trailing "\0".
1519		 */
1520		i = 0;
1521		for (p = name; p < name + namelen; p++) {
1522			if (*p && *p == '.')
1523				i++;
1524		}
1525		if (i < 2)
1526			nterm = 2;
1527		else
1528			nterm = 1;
1529
1530		p = name;
1531		while (cp < ep && p < name + namelen) {
1532			i = 0;
1533			for (q = p; q < name + namelen && *q && *q != '.'; q++)
1534				i++;
1535			/* result does not fit into mbuf */
1536			if (cp + i + 1 >= ep)
1537				goto fail;
1538			/*
1539			 * DNS label length restriction, RFC1035 page 8.
1540			 * "i == 0" case is included here to avoid returning
1541			 * 0-length label on "foo..bar".
1542			 */
1543			if (i <= 0 || i >= 64)
1544				goto fail;
1545			*cp++ = i;
1546			if (!isalpha(p[0]) || !isalnum(p[i - 1]))
1547				goto fail;
1548			while (i > 0) {
1549				if (!isalnum(*p) && *p != '-')
1550					goto fail;
1551				if (isupper(*p)) {
1552					*cp++ = tolower(*p);
1553					p++;
1554				} else
1555					*cp++ = *p++;
1556				i--;
1557			}
1558			p = q;
1559			if (p < name + namelen && *p == '.')
1560				p++;
1561		}
1562		/* termination */
1563		if (cp + nterm >= ep)
1564			goto fail;
1565		while (nterm-- > 0)
1566			*cp++ = '\0';
1567		m->m_len = cp - mtod(m, char *);
1568		return m;
1569	}
1570
1571	panic("should not reach here");
1572	/* NOTREACHED */
1573
1574 fail:
1575	if (m)
1576		m_freem(m);
1577	return NULL;
1578}
1579
1580/*
1581 * check if two DNS-encoded string matches.  takes care of truncated
1582 * form (with \0\0 at the end).  no compression support.
1583 * XXX upper/lowercase match (see RFC2065)
1584 */
1585static int
1586ni6_dnsmatch(a, alen, b, blen)
1587	const char *a;
1588	int alen;
1589	const char *b;
1590	int blen;
1591{
1592	const char *a0, *b0;
1593	int l;
1594
1595	/* simplest case - need validation? */
1596	if (alen == blen && bcmp(a, b, alen) == 0)
1597		return 1;
1598
1599	a0 = a;
1600	b0 = b;
1601
1602	/* termination is mandatory */
1603	if (alen < 2 || blen < 2)
1604		return 0;
1605	if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1606		return 0;
1607	alen--;
1608	blen--;
1609
1610	while (a - a0 < alen && b - b0 < blen) {
1611		if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1612			return 0;
1613
1614		if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1615			return 0;
1616		/* we don't support compression yet */
1617		if (a[0] >= 64 || b[0] >= 64)
1618			return 0;
1619
1620		/* truncated case */
1621		if (a[0] == 0 && a - a0 == alen - 1)
1622			return 1;
1623		if (b[0] == 0 && b - b0 == blen - 1)
1624			return 1;
1625		if (a[0] == 0 || b[0] == 0)
1626			return 0;
1627
1628		if (a[0] != b[0])
1629			return 0;
1630		l = a[0];
1631		if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1632			return 0;
1633		if (bcmp(a + 1, b + 1, l) != 0)
1634			return 0;
1635
1636		a += 1 + l;
1637		b += 1 + l;
1638	}
1639
1640	if (a - a0 == alen && b - b0 == blen)
1641		return 1;
1642	else
1643		return 0;
1644}
1645
1646/*
1647 * calculate the number of addresses to be returned in the node info reply.
1648 */
1649static int
1650ni6_addrs(ni6, m, ifpp, subj)
1651	struct icmp6_nodeinfo *ni6;
1652	struct mbuf *m;
1653	struct ifnet **ifpp;
1654	char *subj;
1655{
1656	struct ifnet *ifp;
1657	struct in6_ifaddr *ifa6;
1658	struct ifaddr *ifa;
1659	struct sockaddr_in6 *subj_ip6 = NULL; /* XXX pedant */
1660	int addrs = 0, addrsofif, iffound = 0;
1661	int niflags = ni6->ni_flags;
1662
1663	if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1664		switch (ni6->ni_code) {
1665		case ICMP6_NI_SUBJ_IPV6:
1666			if (subj == NULL) /* must be impossible... */
1667				return (0);
1668			subj_ip6 = (struct sockaddr_in6 *)subj;
1669			break;
1670		default:
1671			/*
1672			 * XXX: we only support IPv6 subject address for
1673			 * this Qtype.
1674			 */
1675			return (0);
1676		}
1677	}
1678
1679	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
1680	{
1681		addrsofif = 0;
1682		for (ifa = ifp->if_addrlist.tqh_first; ifa;
1683		     ifa = ifa->ifa_list.tqe_next)
1684		{
1685			if (ifa->ifa_addr->sa_family != AF_INET6)
1686				continue;
1687			ifa6 = (struct in6_ifaddr *)ifa;
1688
1689			if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1690			    IN6_ARE_ADDR_EQUAL(&subj_ip6->sin6_addr,
1691					       &ifa6->ia_addr.sin6_addr))
1692				iffound = 1;
1693
1694			/*
1695			 * IPv4-mapped addresses can only be returned by a
1696			 * Node Information proxy, since they represent
1697			 * addresses of IPv4-only nodes, which perforce do
1698			 * not implement this protocol.
1699			 * [icmp-name-lookups-07, Section 5.4]
1700			 * So we don't support NI_NODEADDR_FLAG_COMPAT in
1701			 * this function at this moment.
1702			 */
1703
1704			/* What do we have to do about ::1? */
1705			switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1706			case IPV6_ADDR_SCOPE_LINKLOCAL:
1707				if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1708					continue;
1709				break;
1710			case IPV6_ADDR_SCOPE_SITELOCAL:
1711				if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1712					continue;
1713				break;
1714			case IPV6_ADDR_SCOPE_GLOBAL:
1715				if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1716					continue;
1717				break;
1718			default:
1719				continue;
1720			}
1721
1722			/*
1723			 * check if anycast is okay.
1724			 * XXX: just experimental.  not in the spec.
1725			 */
1726			if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1727			    (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1728				continue; /* we need only unicast addresses */
1729
1730			addrsofif++; /* count the address */
1731		}
1732		if (iffound) {
1733			*ifpp = ifp;
1734			return (addrsofif);
1735		}
1736
1737		addrs += addrsofif;
1738	}
1739
1740	return (addrs);
1741}
1742
1743static int
1744ni6_store_addrs(ni6, nni6, ifp0, resid)
1745	struct icmp6_nodeinfo *ni6, *nni6;
1746	struct ifnet *ifp0;
1747	int resid;
1748{
1749	struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet);
1750	struct in6_ifaddr *ifa6;
1751	struct ifaddr *ifa;
1752	struct ifnet *ifp_dep = NULL;
1753	int copied = 0, allow_deprecated = 0;
1754	u_char *cp = (u_char *)(nni6 + 1);
1755	int niflags = ni6->ni_flags;
1756	u_int32_t ltime;
1757
1758	if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1759		return (0);	/* needless to copy */
1760
1761  again:
1762
1763	for (; ifp; ifp = TAILQ_NEXT(ifp, if_list))
1764	{
1765		for (ifa = ifp->if_addrlist.tqh_first; ifa;
1766		     ifa = ifa->ifa_list.tqe_next)
1767		{
1768			if (ifa->ifa_addr->sa_family != AF_INET6)
1769				continue;
1770			ifa6 = (struct in6_ifaddr *)ifa;
1771
1772			if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1773			    allow_deprecated == 0) {
1774				/*
1775				 * prefererred address should be put before
1776				 * deprecated addresses.
1777				 */
1778
1779				/* record the interface for later search */
1780				if (ifp_dep == NULL)
1781					ifp_dep = ifp;
1782
1783				continue;
1784			}
1785			else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1786				 allow_deprecated != 0)
1787				continue; /* we now collect deprecated addrs */
1788
1789			/* What do we have to do about ::1? */
1790			switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1791			case IPV6_ADDR_SCOPE_LINKLOCAL:
1792				if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1793					continue;
1794				break;
1795			case IPV6_ADDR_SCOPE_SITELOCAL:
1796				if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1797					continue;
1798				break;
1799			case IPV6_ADDR_SCOPE_GLOBAL:
1800				if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1801					continue;
1802				break;
1803			default:
1804				continue;
1805			}
1806
1807			/*
1808			 * check if anycast is okay.
1809			 * XXX: just experimental.  not in the spec.
1810			 */
1811			if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1812			    (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1813				continue;
1814
1815			/* now we can copy the address */
1816			if (resid < sizeof(struct in6_addr) +
1817			    sizeof(u_int32_t)) {
1818				/*
1819				 * We give up much more copy.
1820				 * Set the truncate flag and return.
1821				 */
1822				nni6->ni_flags |=
1823					NI_NODEADDR_FLAG_TRUNCATE;
1824				return (copied);
1825			}
1826
1827			/*
1828			 * Set the TTL of the address.
1829			 * The TTL value should be one of the following
1830			 * according to the specification:
1831			 *
1832			 * 1. The remaining lifetime of a DHCP lease on the
1833			 *    address, or
1834			 * 2. The remaining Valid Lifetime of a prefix from
1835			 *    which the address was derived through Stateless
1836			 *    Autoconfiguration.
1837			 *
1838			 * Note that we currently do not support stateful
1839			 * address configuration by DHCPv6, so the former
1840			 * case can't happen.
1841			 *
1842			 * TTL must be 2^31 > TTL >= 0.
1843			 */
1844			if (ifa6->ia6_lifetime.ia6t_expire == 0)
1845				ltime = ND6_INFINITE_LIFETIME;
1846			else {
1847				if (ifa6->ia6_lifetime.ia6t_expire >
1848				    time.tv_sec)
1849					ltime = ifa6->ia6_lifetime.ia6t_expire - time.tv_sec;
1850				else
1851					ltime = 0;
1852			}
1853			if (ltime > 0x7fffffff)
1854				ltime = 0x7fffffff;
1855			ltime = htonl(ltime);
1856
1857			bcopy(&ltime, cp, sizeof(u_int32_t));
1858			cp += sizeof(u_int32_t);
1859
1860			/* copy the address itself */
1861			bcopy(&ifa6->ia_addr.sin6_addr, cp,
1862			      sizeof(struct in6_addr));
1863			/* XXX: KAME link-local hack; remove ifindex */
1864			if (IN6_IS_ADDR_LINKLOCAL(&ifa6->ia_addr.sin6_addr))
1865				((struct in6_addr *)cp)->s6_addr16[1] = 0;
1866			cp += sizeof(struct in6_addr);
1867
1868			resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1869			copied += (sizeof(struct in6_addr) +
1870				   sizeof(u_int32_t));
1871		}
1872		if (ifp0)	/* we need search only on the specified IF */
1873			break;
1874	}
1875
1876	if (allow_deprecated == 0 && ifp_dep != NULL) {
1877		ifp = ifp_dep;
1878		allow_deprecated = 1;
1879
1880		goto again;
1881	}
1882
1883	return (copied);
1884}
1885
1886/*
1887 * XXX almost dup'ed code with rip6_input.
1888 */
1889static int
1890icmp6_rip6_input(mp, off)
1891	struct	mbuf **mp;
1892	int	off;
1893{
1894	struct mbuf *m = *mp;
1895	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1896	struct inpcb_hdr *inph;
1897	struct in6pcb *in6p;
1898	struct in6pcb *last = NULL;
1899	struct sockaddr_in6 rip6src;
1900	struct icmp6_hdr *icmp6;
1901	struct mbuf *opts = NULL;
1902
1903	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1904	if (icmp6 == NULL) {
1905		/* m is already reclaimed */
1906		return IPPROTO_DONE;
1907	}
1908
1909	bzero(&rip6src, sizeof(rip6src));
1910	rip6src.sin6_len = sizeof(struct sockaddr_in6);
1911	rip6src.sin6_family = AF_INET6;
1912	/* KAME hack: recover scopeid */
1913	(void)in6_recoverscope(&rip6src, &ip6->ip6_src, m->m_pkthdr.rcvif);
1914
1915	CIRCLEQ_FOREACH(inph, &raw6cbtable.inpt_queue, inph_queue) {
1916		in6p = (struct in6pcb *)inph;
1917		if (in6p->in6p_af != AF_INET6)
1918			continue;
1919		if (in6p->in6p_ip6.ip6_nxt != IPPROTO_ICMPV6)
1920			continue;
1921		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1922		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1923			continue;
1924		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1925		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1926			continue;
1927		if (in6p->in6p_icmp6filt
1928		    && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1929				 in6p->in6p_icmp6filt))
1930			continue;
1931		if (last) {
1932			struct	mbuf *n;
1933			if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
1934				if (last->in6p_flags & IN6P_CONTROLOPTS)
1935					ip6_savecontrol(last, &opts, ip6, n);
1936				/* strip intermediate headers */
1937				m_adj(n, off);
1938				if (sbappendaddr(&last->in6p_socket->so_rcv,
1939						 (struct sockaddr *)&rip6src,
1940						 n, opts) == 0) {
1941					/* should notify about lost packet */
1942					m_freem(n);
1943					if (opts)
1944						m_freem(opts);
1945				} else
1946					sorwakeup(last->in6p_socket);
1947				opts = NULL;
1948			}
1949		}
1950		last = in6p;
1951	}
1952	if (last) {
1953		if (last->in6p_flags & IN6P_CONTROLOPTS)
1954			ip6_savecontrol(last, &opts, ip6, m);
1955		/* strip intermediate headers */
1956		m_adj(m, off);
1957		if (sbappendaddr(&last->in6p_socket->so_rcv,
1958				(struct sockaddr *)&rip6src, m, opts) == 0) {
1959			m_freem(m);
1960			if (opts)
1961				m_freem(opts);
1962		} else
1963			sorwakeup(last->in6p_socket);
1964	} else {
1965		m_freem(m);
1966		ip6stat.ip6s_delivered--;
1967	}
1968	return IPPROTO_DONE;
1969}
1970
1971/*
1972 * Reflect the ip6 packet back to the source.
1973 * OFF points to the icmp6 header, counted from the top of the mbuf.
1974 *
1975 * Note: RFC 1885 required that an echo reply should be truncated if it
1976 * did not fit in with (return) path MTU, and KAME code supported the
1977 * behavior.  However, as a clarification after the RFC, this limitation
1978 * was removed in a revised version of the spec, RFC 2463.  We had kept the
1979 * old behavior, with a (non-default) ifdef block, while the new version of
1980 * the spec was an internet-draft status, and even after the new RFC was
1981 * published.  But it would rather make sense to clean the obsoleted part
1982 * up, and to make the code simpler at this stage.
1983 */
1984void
1985icmp6_reflect(m, off)
1986	struct	mbuf *m;
1987	size_t off;
1988{
1989	struct ip6_hdr *ip6;
1990	struct icmp6_hdr *icmp6;
1991	struct in6_ifaddr *ia;
1992	struct in6_addr t, *src = 0;
1993	int plen;
1994	int type, code;
1995	struct ifnet *outif = NULL;
1996	struct sockaddr_in6 sa6_src, sa6_dst;
1997
1998	/* too short to reflect */
1999	if (off < sizeof(struct ip6_hdr)) {
2000		nd6log((LOG_DEBUG,
2001		    "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2002		    (u_long)off, (u_long)sizeof(struct ip6_hdr),
2003		    __FILE__, __LINE__));
2004		goto bad;
2005	}
2006
2007	/*
2008	 * If there are extra headers between IPv6 and ICMPv6, strip
2009	 * off that header first.
2010	 */
2011#ifdef DIAGNOSTIC
2012	if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2013		panic("assumption failed in icmp6_reflect");
2014#endif
2015	if (off > sizeof(struct ip6_hdr)) {
2016		size_t l;
2017		struct ip6_hdr nip6;
2018
2019		l = off - sizeof(struct ip6_hdr);
2020		m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2021		m_adj(m, l);
2022		l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2023		if (m->m_len < l) {
2024			if ((m = m_pullup(m, l)) == NULL)
2025				return;
2026		}
2027		bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2028	} else /* off == sizeof(struct ip6_hdr) */ {
2029		size_t l;
2030		l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2031		if (m->m_len < l) {
2032			if ((m = m_pullup(m, l)) == NULL)
2033				return;
2034		}
2035	}
2036	plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2037	ip6 = mtod(m, struct ip6_hdr *);
2038	ip6->ip6_nxt = IPPROTO_ICMPV6;
2039	icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2040	type = icmp6->icmp6_type; /* keep type for statistics */
2041	code = icmp6->icmp6_code; /* ditto. */
2042
2043	t = ip6->ip6_dst;
2044	/*
2045	 * ip6_input() drops a packet if its src is multicast.
2046	 * So, the src is never multicast.
2047	 */
2048	ip6->ip6_dst = ip6->ip6_src;
2049
2050	/*
2051	 * XXX: make sure to embed scope zone information, using
2052	 * already embedded IDs or the received interface (if any).
2053	 * Note that rcvif may be NULL.
2054	 * TODO: scoped routing case (XXX).
2055	 */
2056	bzero(&sa6_src, sizeof(sa6_src));
2057	sa6_src.sin6_family = AF_INET6;
2058	sa6_src.sin6_len = sizeof(sa6_src);
2059	sa6_src.sin6_addr = ip6->ip6_dst;
2060	in6_recoverscope(&sa6_src, &ip6->ip6_dst, m->m_pkthdr.rcvif);
2061	in6_embedscope(&sa6_src.sin6_addr, &sa6_src, NULL, NULL);
2062	ip6->ip6_dst = sa6_src.sin6_addr;
2063
2064	bzero(&sa6_dst, sizeof(sa6_dst));
2065	sa6_dst.sin6_family = AF_INET6;
2066	sa6_dst.sin6_len = sizeof(sa6_dst);
2067	sa6_dst.sin6_addr = t;
2068	in6_recoverscope(&sa6_dst, &t, m->m_pkthdr.rcvif);
2069	in6_embedscope(&t, &sa6_dst, NULL, NULL);
2070
2071	/*
2072	 * If the incoming packet was addressed directly to us (i.e. unicast),
2073	 * use dst as the src for the reply.
2074	 * The IN6_IFF_NOTREADY case would be VERY rare, but is possible
2075	 * (for example) when we encounter an error while forwarding procedure
2076	 * destined to a duplicated address of ours.
2077	 */
2078	for (ia = in6_ifaddr; ia; ia = ia->ia_next)
2079		if (IN6_ARE_ADDR_EQUAL(&t, &ia->ia_addr.sin6_addr) &&
2080		    (ia->ia6_flags & (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) {
2081			src = &t;
2082			break;
2083		}
2084	if (ia == NULL && IN6_IS_ADDR_LINKLOCAL(&t) && (m->m_flags & M_LOOP)) {
2085		/*
2086		 * This is the case if the dst is our link-local address
2087		 * and the sender is also ourselves.
2088		 */
2089		src = &t;
2090	}
2091
2092	if (src == 0) {
2093		int e;
2094		struct route_in6 ro;
2095
2096		/*
2097		 * This case matches to multicasts, our anycast, or unicasts
2098		 * that we do not own.  Select a source address based on the
2099		 * source address of the erroneous packet.
2100		 */
2101		bzero(&ro, sizeof(ro));
2102		src = in6_selectsrc(&sa6_src, NULL, NULL, &ro, NULL, &e);
2103		if (ro.ro_rt) { /* XXX: see comments in icmp6_mtudisc_update */
2104			RTFREE(ro.ro_rt); /* XXX: we could use this */
2105		}
2106		if (src == NULL) {
2107			nd6log((LOG_DEBUG,
2108			    "icmp6_reflect: source can't be determined: "
2109			    "dst=%s, error=%d\n",
2110			    ip6_sprintf(&sa6_src.sin6_addr), e));
2111			goto bad;
2112		}
2113	}
2114
2115	ip6->ip6_src = *src;
2116
2117	ip6->ip6_flow = 0;
2118	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2119	ip6->ip6_vfc |= IPV6_VERSION;
2120	ip6->ip6_nxt = IPPROTO_ICMPV6;
2121	if (m->m_pkthdr.rcvif) {
2122		/* XXX: This may not be the outgoing interface */
2123		ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2124	} else
2125		ip6->ip6_hlim = ip6_defhlim;
2126
2127	icmp6->icmp6_cksum = 0;
2128	icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2129					sizeof(struct ip6_hdr), plen);
2130
2131	/*
2132	 * XXX option handling
2133	 */
2134
2135	m->m_flags &= ~(M_BCAST|M_MCAST);
2136
2137	/*
2138	 * To avoid a "too big" situation at an intermediate router
2139	 * and the path MTU discovery process, specify the IPV6_MINMTU flag.
2140	 * Note that only echo and node information replies are affected,
2141	 * since the length of ICMP6 errors is limited to the minimum MTU.
2142	 */
2143	if (ip6_output(m, NULL, NULL, IPV6_MINMTU,
2144		(struct ip6_moptions *)NULL, (struct socket *)NULL, &outif) != 0
2145	    && outif)
2146		icmp6_ifstat_inc(outif, ifs6_out_error);
2147
2148	if (outif)
2149		icmp6_ifoutstat_inc(outif, type, code);
2150
2151	return;
2152
2153 bad:
2154	m_freem(m);
2155	return;
2156}
2157
2158void
2159icmp6_fasttimo()
2160{
2161
2162	mld6_fasttimeo();
2163}
2164
2165static const char *
2166icmp6_redirect_diag(src6, dst6, tgt6)
2167	struct in6_addr *src6;
2168	struct in6_addr *dst6;
2169	struct in6_addr *tgt6;
2170{
2171	static char buf[1024];
2172	snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2173		ip6_sprintf(src6), ip6_sprintf(dst6), ip6_sprintf(tgt6));
2174	return buf;
2175}
2176
2177void
2178icmp6_redirect_input(m, off)
2179	struct mbuf *m;
2180	int off;
2181{
2182	struct ifnet *ifp = m->m_pkthdr.rcvif;
2183	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2184	struct nd_redirect *nd_rd;
2185	int icmp6len = ntohs(ip6->ip6_plen);
2186	char *lladdr = NULL;
2187	int lladdrlen = 0;
2188	struct rtentry *rt = NULL;
2189	int is_router;
2190	int is_onlink;
2191	struct in6_addr src6 = ip6->ip6_src;
2192	struct in6_addr redtgt6;
2193	struct in6_addr reddst6;
2194	union nd_opts ndopts;
2195
2196	if (!ifp)
2197		return;
2198
2199	/* XXX if we are router, we don't update route by icmp6 redirect */
2200	if (ip6_forwarding)
2201		goto freeit;
2202	if (!icmp6_rediraccept)
2203		goto freeit;
2204
2205	IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2206	if (nd_rd == NULL) {
2207		icmp6stat.icp6s_tooshort++;
2208		return;
2209	}
2210	redtgt6 = nd_rd->nd_rd_target;
2211	reddst6 = nd_rd->nd_rd_dst;
2212
2213	if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2214		redtgt6.s6_addr16[1] = htons(ifp->if_index);
2215	if (IN6_IS_ADDR_LINKLOCAL(&reddst6))
2216		reddst6.s6_addr16[1] = htons(ifp->if_index);
2217
2218	/* validation */
2219	if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2220		nd6log((LOG_ERR,
2221			"ICMP6 redirect sent from %s rejected; "
2222			"must be from linklocal\n", ip6_sprintf(&src6)));
2223		goto bad;
2224	}
2225	if (ip6->ip6_hlim != 255) {
2226		nd6log((LOG_ERR,
2227			"ICMP6 redirect sent from %s rejected; "
2228			"hlim=%d (must be 255)\n",
2229			ip6_sprintf(&src6), ip6->ip6_hlim));
2230		goto bad;
2231	}
2232    {
2233	/* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2234	struct sockaddr_in6 sin6;
2235	struct in6_addr *gw6;
2236
2237	bzero(&sin6, sizeof(sin6));
2238	sin6.sin6_family = AF_INET6;
2239	sin6.sin6_len = sizeof(struct sockaddr_in6);
2240	bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
2241	rt = rtalloc1((struct sockaddr *)&sin6, 0);
2242	if (rt) {
2243		if (rt->rt_gateway == NULL ||
2244		    rt->rt_gateway->sa_family != AF_INET6) {
2245			nd6log((LOG_ERR,
2246			    "ICMP6 redirect rejected; no route "
2247			    "with inet6 gateway found for redirect dst: %s\n",
2248			    icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2249			RTFREE(rt);
2250			goto bad;
2251		}
2252
2253		gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2254		if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2255			nd6log((LOG_ERR,
2256				"ICMP6 redirect rejected; "
2257				"not equal to gw-for-src=%s (must be same): "
2258				"%s\n",
2259				ip6_sprintf(gw6),
2260				icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2261			RTFREE(rt);
2262			goto bad;
2263		}
2264	} else {
2265		nd6log((LOG_ERR,
2266			"ICMP6 redirect rejected; "
2267			"no route found for redirect dst: %s\n",
2268			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2269		goto bad;
2270	}
2271	RTFREE(rt);
2272	rt = NULL;
2273    }
2274	if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2275		nd6log((LOG_ERR,
2276			"ICMP6 redirect rejected; "
2277			"redirect dst must be unicast: %s\n",
2278			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2279		goto bad;
2280	}
2281
2282	is_router = is_onlink = 0;
2283	if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2284		is_router = 1;	/* router case */
2285	if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2286		is_onlink = 1;	/* on-link destination case */
2287	if (!is_router && !is_onlink) {
2288		nd6log((LOG_ERR,
2289			"ICMP6 redirect rejected; "
2290			"neither router case nor onlink case: %s\n",
2291			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2292		goto bad;
2293	}
2294	/* validation passed */
2295
2296	icmp6len -= sizeof(*nd_rd);
2297	nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2298	if (nd6_options(&ndopts) < 0) {
2299		nd6log((LOG_INFO, "icmp6_redirect_input: "
2300			"invalid ND option, rejected: %s\n",
2301			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2302		/* nd6_options have incremented stats */
2303		goto freeit;
2304	}
2305
2306	if (ndopts.nd_opts_tgt_lladdr) {
2307		lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2308		lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2309	}
2310
2311	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2312		nd6log((LOG_INFO,
2313			"icmp6_redirect_input: lladdrlen mismatch for %s "
2314			"(if %d, icmp6 packet %d): %s\n",
2315			ip6_sprintf(&redtgt6), ifp->if_addrlen, lladdrlen - 2,
2316			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2317		goto bad;
2318	}
2319
2320	/* RFC 2461 8.3 */
2321	nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2322			 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2323
2324	if (!is_onlink) {	/* better router case.  perform rtredirect. */
2325		/* perform rtredirect */
2326		struct sockaddr_in6 sdst;
2327		struct sockaddr_in6 sgw;
2328		struct sockaddr_in6 ssrc;
2329		unsigned long rtcount;
2330		struct rtentry *newrt = NULL;
2331
2332		/*
2333		 * do not install redirect route, if the number of entries
2334		 * is too much (> hiwat).  note that, the node (= host) will
2335		 * work just fine even if we do not install redirect route
2336		 * (there will be additional hops, though).
2337		 */
2338		rtcount = rt_timer_count(icmp6_redirect_timeout_q);
2339		if (0 <= icmp6_redirect_hiwat && rtcount > icmp6_redirect_hiwat)
2340			return;
2341		else if (0 <= icmp6_redirect_lowat &&
2342		    rtcount > icmp6_redirect_lowat) {
2343			/*
2344			 * XXX nuke a victim, install the new one.
2345			 */
2346		}
2347
2348		bzero(&sdst, sizeof(sdst));
2349		bzero(&sgw, sizeof(sgw));
2350		bzero(&ssrc, sizeof(ssrc));
2351		sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2352		sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2353			sizeof(struct sockaddr_in6);
2354		bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2355		bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2356		bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2357		rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2358			   (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
2359			   (struct sockaddr *)&ssrc,
2360			   &newrt);
2361
2362		if (newrt) {
2363			(void)rt_timer_add(newrt, icmp6_redirect_timeout,
2364			    icmp6_redirect_timeout_q);
2365			rtfree(newrt);
2366		}
2367	}
2368	/* finally update cached route in each socket via pfctlinput */
2369	{
2370		struct sockaddr_in6 sdst;
2371
2372		bzero(&sdst, sizeof(sdst));
2373		sdst.sin6_family = AF_INET6;
2374		sdst.sin6_len = sizeof(struct sockaddr_in6);
2375		bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2376		pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2377#ifdef IPSEC
2378		key_sa_routechange((struct sockaddr *)&sdst);
2379#endif
2380	}
2381
2382 freeit:
2383	m_freem(m);
2384	return;
2385
2386 bad:
2387	icmp6stat.icp6s_badredirect++;
2388	m_freem(m);
2389}
2390
2391void
2392icmp6_redirect_output(m0, rt)
2393	struct mbuf *m0;
2394	struct rtentry *rt;
2395{
2396	struct ifnet *ifp;	/* my outgoing interface */
2397	struct in6_addr *ifp_ll6;
2398	struct in6_addr *nexthop;
2399	struct ip6_hdr *sip6;	/* m0 as struct ip6_hdr */
2400	struct mbuf *m = NULL;	/* newly allocated one */
2401	struct ip6_hdr *ip6;	/* m as struct ip6_hdr */
2402	struct nd_redirect *nd_rd;
2403	size_t maxlen;
2404	u_char *p;
2405	struct sockaddr_in6 src_sa;
2406
2407	icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
2408
2409	/* if we are not router, we don't send icmp6 redirect */
2410	if (!ip6_forwarding)
2411		goto fail;
2412
2413	/* sanity check */
2414	if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2415		goto fail;
2416
2417	/*
2418	 * Address check:
2419	 *  the source address must identify a neighbor, and
2420	 *  the destination address must not be a multicast address
2421	 *  [RFC 2461, sec 8.2]
2422	 */
2423	sip6 = mtod(m0, struct ip6_hdr *);
2424	bzero(&src_sa, sizeof(src_sa));
2425	src_sa.sin6_family = AF_INET6;
2426	src_sa.sin6_len = sizeof(src_sa);
2427	src_sa.sin6_addr = sip6->ip6_src;
2428	/* we don't currently use sin6_scope_id, but eventually use it */
2429	src_sa.sin6_scope_id = in6_addr2scopeid(ifp, &sip6->ip6_src);
2430	if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2431		goto fail;
2432	if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2433		goto fail;	/* what should we do here? */
2434
2435	/* rate limit */
2436	if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2437		goto fail;
2438
2439	/*
2440	 * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2441	 * we almost always ask for an mbuf cluster for simplicity.
2442	 * (MHLEN < IPV6_MMTU is almost always true)
2443	 */
2444#if IPV6_MMTU >= MCLBYTES
2445# error assumption failed about IPV6_MMTU and MCLBYTES
2446#endif
2447	MGETHDR(m, M_DONTWAIT, MT_HEADER);
2448	if (m && IPV6_MMTU >= MHLEN)
2449		MCLGET(m, M_DONTWAIT);
2450	if (!m)
2451		goto fail;
2452	m->m_pkthdr.rcvif = NULL;
2453	m->m_len = 0;
2454	maxlen = M_TRAILINGSPACE(m);
2455	maxlen = min(IPV6_MMTU, maxlen);
2456	/* just for safety */
2457	if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2458	    ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2459		goto fail;
2460	}
2461
2462	{
2463		/* get ip6 linklocal address for ifp(my outgoing interface). */
2464		struct in6_ifaddr *ia;
2465		if ((ia = in6ifa_ifpforlinklocal(ifp,
2466						 IN6_IFF_NOTREADY|
2467						 IN6_IFF_ANYCAST)) == NULL)
2468			goto fail;
2469		ifp_ll6 = &ia->ia_addr.sin6_addr;
2470	}
2471
2472	/* get ip6 linklocal address for the router. */
2473	if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2474		struct sockaddr_in6 *sin6;
2475		sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2476		nexthop = &sin6->sin6_addr;
2477		if (!IN6_IS_ADDR_LINKLOCAL(nexthop))
2478			nexthop = NULL;
2479	} else
2480		nexthop = NULL;
2481
2482	/* ip6 */
2483	ip6 = mtod(m, struct ip6_hdr *);
2484	ip6->ip6_flow = 0;
2485	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2486	ip6->ip6_vfc |= IPV6_VERSION;
2487	/* ip6->ip6_plen will be set later */
2488	ip6->ip6_nxt = IPPROTO_ICMPV6;
2489	ip6->ip6_hlim = 255;
2490	/* ip6->ip6_src must be linklocal addr for my outgoing if. */
2491	bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2492	bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2493
2494	/* ND Redirect */
2495	nd_rd = (struct nd_redirect *)(ip6 + 1);
2496	nd_rd->nd_rd_type = ND_REDIRECT;
2497	nd_rd->nd_rd_code = 0;
2498	nd_rd->nd_rd_reserved = 0;
2499	if (rt->rt_flags & RTF_GATEWAY) {
2500		/*
2501		 * nd_rd->nd_rd_target must be a link-local address in
2502		 * better router cases.
2503		 */
2504		if (!nexthop)
2505			goto fail;
2506		bcopy(nexthop, &nd_rd->nd_rd_target,
2507		      sizeof(nd_rd->nd_rd_target));
2508		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2509		      sizeof(nd_rd->nd_rd_dst));
2510	} else {
2511		/* make sure redtgt == reddst */
2512		nexthop = &sip6->ip6_dst;
2513		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2514		      sizeof(nd_rd->nd_rd_target));
2515		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2516		      sizeof(nd_rd->nd_rd_dst));
2517	}
2518
2519	p = (u_char *)(nd_rd + 1);
2520
2521	{
2522		/* target lladdr option */
2523		struct rtentry *rt_nexthop = NULL;
2524		int len;
2525		struct sockaddr_dl *sdl;
2526		struct nd_opt_hdr *nd_opt;
2527		char *lladdr;
2528
2529		rt_nexthop = nd6_lookup(nexthop, 0, ifp);
2530		if (!rt_nexthop)
2531			goto nolladdropt;
2532		len = sizeof(*nd_opt) + ifp->if_addrlen;
2533		len = (len + 7) & ~7;	/* round by 8 */
2534		/* safety check */
2535		if (len + (p - (u_char *)ip6) > maxlen)
2536			goto nolladdropt;
2537		if (!(rt_nexthop->rt_flags & RTF_GATEWAY) &&
2538		    (rt_nexthop->rt_flags & RTF_LLINFO) &&
2539		    (rt_nexthop->rt_gateway->sa_family == AF_LINK) &&
2540		    (sdl = (struct sockaddr_dl *)rt_nexthop->rt_gateway) &&
2541		    sdl->sdl_alen) {
2542			nd_opt = (struct nd_opt_hdr *)p;
2543			nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2544			nd_opt->nd_opt_len = len >> 3;
2545			lladdr = (char *)(nd_opt + 1);
2546			bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen);
2547			p += len;
2548		}
2549	}
2550  nolladdropt:;
2551
2552	m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2553
2554	/* just to be safe */
2555	if (m0->m_flags & M_DECRYPTED)
2556		goto noredhdropt;
2557	if (p - (u_char *)ip6 > maxlen)
2558		goto noredhdropt;
2559
2560	{
2561		/* redirected header option */
2562		int len;
2563		struct nd_opt_rd_hdr *nd_opt_rh;
2564
2565		/*
2566		 * compute the maximum size for icmp6 redirect header option.
2567		 * XXX room for auth header?
2568		 */
2569		len = maxlen - (p - (u_char *)ip6);
2570		len &= ~7;
2571
2572		/*
2573		 * Redirected header option spec (RFC2461 4.6.3) talks nothing
2574		 * about padding/truncate rule for the original IP packet.
2575		 * From the discussion on IPv6imp in Feb 1999,
2576		 * the consensus was:
2577		 * - "attach as much as possible" is the goal
2578		 * - pad if not aligned (original size can be guessed by
2579		 *   original ip6 header)
2580		 * Following code adds the padding if it is simple enough,
2581		 * and truncates if not.
2582		 */
2583		if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2584			/* not enough room, truncate */
2585			m_adj(m0, (len - sizeof(*nd_opt_rh)) -
2586			    m0->m_pkthdr.len);
2587		} else {
2588			/*
2589                         * enough room, truncate if not aligned.
2590			 * we don't pad here for simplicity.
2591			 */
2592			size_t extra;
2593
2594			extra = m0->m_pkthdr.len % 8;
2595			if (extra) {
2596				/* truncate */
2597				m_adj(m0, -extra);
2598			}
2599			len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2600		}
2601
2602		nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2603		bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2604		nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2605		nd_opt_rh->nd_opt_rh_len = len >> 3;
2606		p += sizeof(*nd_opt_rh);
2607		m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2608
2609		/* connect m0 to m */
2610		m->m_pkthdr.len += m0->m_pkthdr.len;
2611		m_cat(m, m0);
2612		m0 = NULL;
2613	}
2614noredhdropt:
2615	if (m0) {
2616		m_freem(m0);
2617		m0 = NULL;
2618	}
2619
2620	sip6 = mtod(m, struct ip6_hdr *);
2621	if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_src))
2622		sip6->ip6_src.s6_addr16[1] = 0;
2623	if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_dst))
2624		sip6->ip6_dst.s6_addr16[1] = 0;
2625#if 0
2626	if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
2627		ip6->ip6_src.s6_addr16[1] = 0;
2628	if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
2629		ip6->ip6_dst.s6_addr16[1] = 0;
2630#endif
2631	if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_target))
2632		nd_rd->nd_rd_target.s6_addr16[1] = 0;
2633	if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_dst))
2634		nd_rd->nd_rd_dst.s6_addr16[1] = 0;
2635
2636	ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2637
2638	nd_rd->nd_rd_cksum = 0;
2639	nd_rd->nd_rd_cksum
2640		= in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), ntohs(ip6->ip6_plen));
2641
2642	/* send the packet to outside... */
2643	if (ip6_output(m, NULL, NULL, 0,
2644		(struct ip6_moptions *)NULL, (struct socket *)NULL, NULL) != 0)
2645		icmp6_ifstat_inc(ifp, ifs6_out_error);
2646
2647	icmp6_ifstat_inc(ifp, ifs6_out_msg);
2648	icmp6_ifstat_inc(ifp, ifs6_out_redirect);
2649	icmp6stat.icp6s_outhist[ND_REDIRECT]++;
2650
2651	return;
2652
2653fail:
2654	if (m)
2655		m_freem(m);
2656	if (m0)
2657		m_freem(m0);
2658}
2659
2660/*
2661 * ICMPv6 socket option processing.
2662 */
2663int
2664icmp6_ctloutput(op, so, level, optname, mp)
2665	int op;
2666	struct socket *so;
2667	int level, optname;
2668	struct mbuf **mp;
2669{
2670	int error = 0;
2671	int optlen;
2672	struct in6pcb *in6p = sotoin6pcb(so);
2673	struct mbuf *m = *mp;
2674
2675	optlen = m ? m->m_len : 0;
2676
2677	if (level != IPPROTO_ICMPV6) {
2678		if (op == PRCO_SETOPT && m)
2679			(void)m_free(m);
2680		return EINVAL;
2681	}
2682
2683	switch (op) {
2684	case PRCO_SETOPT:
2685		switch (optname) {
2686		case ICMP6_FILTER:
2687		    {
2688			struct icmp6_filter *p;
2689
2690			if (optlen != sizeof(*p)) {
2691				error = EMSGSIZE;
2692				break;
2693			}
2694			p = mtod(m, struct icmp6_filter *);
2695			if (!p || !in6p->in6p_icmp6filt) {
2696				error = EINVAL;
2697				break;
2698			}
2699			bcopy(p, in6p->in6p_icmp6filt,
2700				sizeof(struct icmp6_filter));
2701			error = 0;
2702			break;
2703		    }
2704
2705		default:
2706			error = ENOPROTOOPT;
2707			break;
2708		}
2709		if (m)
2710			(void)m_freem(m);
2711		break;
2712
2713	case PRCO_GETOPT:
2714		switch (optname) {
2715		case ICMP6_FILTER:
2716		    {
2717			struct icmp6_filter *p;
2718
2719			if (!in6p->in6p_icmp6filt) {
2720				error = EINVAL;
2721				break;
2722			}
2723			*mp = m = m_get(M_WAIT, MT_SOOPTS);
2724			m->m_len = sizeof(struct icmp6_filter);
2725			p = mtod(m, struct icmp6_filter *);
2726			bcopy(in6p->in6p_icmp6filt, p,
2727				sizeof(struct icmp6_filter));
2728			error = 0;
2729			break;
2730		    }
2731
2732		default:
2733			error = ENOPROTOOPT;
2734			break;
2735		}
2736		break;
2737	}
2738
2739	return (error);
2740}
2741
2742/*
2743 * Perform rate limit check.
2744 * Returns 0 if it is okay to send the icmp6 packet.
2745 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2746 * limitation.
2747 *
2748 * XXX per-destination/type check necessary?
2749 */
2750static int
2751icmp6_ratelimit(dst, type, code)
2752	const struct in6_addr *dst;	/* not used at this moment */
2753	const int type;			/* not used at this moment */
2754	const int code;			/* not used at this moment */
2755{
2756	int ret;
2757
2758	ret = 0;	/* okay to send */
2759
2760	/* PPS limit */
2761	if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count,
2762	    icmp6errppslim)) {
2763		/* The packet is subject to rate limit */
2764		ret++;
2765	}
2766
2767	return ret;
2768}
2769
2770static struct rtentry *
2771icmp6_mtudisc_clone(dst)
2772	struct sockaddr *dst;
2773{
2774	struct rtentry *rt;
2775	int    error;
2776
2777	rt = rtalloc1(dst, 1);
2778	if (rt == 0)
2779		return NULL;
2780
2781	/* If we didn't get a host route, allocate one */
2782	if ((rt->rt_flags & RTF_HOST) == 0) {
2783		struct rtentry *nrt;
2784
2785		error = rtrequest((int) RTM_ADD, dst,
2786		    (struct sockaddr *) rt->rt_gateway,
2787		    (struct sockaddr *) 0,
2788		    RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt);
2789		if (error) {
2790			rtfree(rt);
2791			return NULL;
2792		}
2793		nrt->rt_rmx = rt->rt_rmx;
2794		rtfree(rt);
2795		rt = nrt;
2796	}
2797	error = rt_timer_add(rt, icmp6_mtudisc_timeout,
2798			icmp6_mtudisc_timeout_q);
2799	if (error) {
2800		rtfree(rt);
2801		return NULL;
2802	}
2803
2804	return rt;	/* caller need to call rtfree() */
2805}
2806
2807static void
2808icmp6_mtudisc_timeout(rt, r)
2809	struct rtentry *rt;
2810	struct rttimer *r;
2811{
2812	if (rt == NULL)
2813		panic("icmp6_mtudisc_timeout: bad route to timeout");
2814	if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) ==
2815	    (RTF_DYNAMIC | RTF_HOST)) {
2816		rtrequest((int) RTM_DELETE, (struct sockaddr *)rt_key(rt),
2817		    rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0);
2818	} else {
2819		if (!(rt->rt_rmx.rmx_locks & RTV_MTU))
2820			rt->rt_rmx.rmx_mtu = 0;
2821	}
2822}
2823
2824static void
2825icmp6_redirect_timeout(rt, r)
2826	struct rtentry *rt;
2827	struct rttimer *r;
2828{
2829	if (rt == NULL)
2830		panic("icmp6_redirect_timeout: bad route to timeout");
2831	if ((rt->rt_flags & (RTF_GATEWAY | RTF_DYNAMIC | RTF_HOST)) ==
2832	    (RTF_GATEWAY | RTF_DYNAMIC | RTF_HOST)) {
2833		rtrequest((int) RTM_DELETE, (struct sockaddr *)rt_key(rt),
2834		    rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0);
2835	}
2836}
2837
2838/*
2839 * sysctl helper routine for the net.inet6.icmp6.nd6 nodes.  silly?
2840 */
2841static int
2842sysctl_net_inet6_icmp6_nd6(SYSCTLFN_ARGS)
2843{
2844
2845	if (namelen != 0)
2846		return (EINVAL);
2847
2848	return (nd6_sysctl(rnode->sysctl_num, oldp, oldlenp,
2849	    /*XXXUNCONST*/
2850	    __UNCONST(newp), newlen));
2851}
2852
2853SYSCTL_SETUP(sysctl_net_inet6_icmp6_setup,
2854	     "sysctl net.inet6.icmp6 subtree setup")
2855{
2856
2857	sysctl_createv(clog, 0, NULL, NULL,
2858		       CTLFLAG_PERMANENT,
2859		       CTLTYPE_NODE, "net", NULL,
2860		       NULL, 0, NULL, 0,
2861		       CTL_NET, CTL_EOL);
2862	sysctl_createv(clog, 0, NULL, NULL,
2863		       CTLFLAG_PERMANENT,
2864		       CTLTYPE_NODE, "inet6", NULL,
2865		       NULL, 0, NULL, 0,
2866		       CTL_NET, PF_INET6, CTL_EOL);
2867	sysctl_createv(clog, 0, NULL, NULL,
2868		       CTLFLAG_PERMANENT,
2869		       CTLTYPE_NODE, "icmp6",
2870		       SYSCTL_DESCR("ICMPv6 related settings"),
2871		       NULL, 0, NULL, 0,
2872		       CTL_NET, PF_INET6, IPPROTO_ICMPV6, CTL_EOL);
2873
2874	sysctl_createv(clog, 0, NULL, NULL,
2875		       CTLFLAG_PERMANENT,
2876		       CTLTYPE_STRUCT, "stats",
2877		       SYSCTL_DESCR("ICMPv6 transmission statistics"),
2878		       NULL, 0, &icmp6stat, sizeof(icmp6stat),
2879		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2880		       ICMPV6CTL_STATS, CTL_EOL);
2881	sysctl_createv(clog, 0, NULL, NULL,
2882		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2883		       CTLTYPE_INT, "rediraccept",
2884		       SYSCTL_DESCR("Accept and process redirect messages"),
2885		       NULL, 0, &icmp6_rediraccept, 0,
2886		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2887		       ICMPV6CTL_REDIRACCEPT, CTL_EOL);
2888	sysctl_createv(clog, 0, NULL, NULL,
2889		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2890		       CTLTYPE_INT, "redirtimeout",
2891		       SYSCTL_DESCR("Redirect generated route lifetime"),
2892		       NULL, 0, &icmp6_redirtimeout, 0,
2893		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2894		       ICMPV6CTL_REDIRTIMEOUT, CTL_EOL);
2895#if 0 /* obsoleted */
2896	sysctl_createv(clog, 0, NULL, NULL,
2897		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2898		       CTLTYPE_INT, "errratelimit", NULL,
2899		       NULL, 0, &icmp6_errratelimit, 0,
2900		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2901		       ICMPV6CTL_ERRRATELIMIT, CTL_EOL);
2902#endif
2903	sysctl_createv(clog, 0, NULL, NULL,
2904		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2905		       CTLTYPE_INT, "nd6_prune",
2906		       SYSCTL_DESCR("Neighbor discovery prune interval"),
2907		       NULL, 0, &nd6_prune, 0,
2908		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2909		       ICMPV6CTL_ND6_PRUNE, CTL_EOL);
2910	sysctl_createv(clog, 0, NULL, NULL,
2911		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2912		       CTLTYPE_INT, "nd6_delay",
2913		       SYSCTL_DESCR("First probe delay time"),
2914		       NULL, 0, &nd6_delay, 0,
2915		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2916		       ICMPV6CTL_ND6_DELAY, CTL_EOL);
2917	sysctl_createv(clog, 0, NULL, NULL,
2918		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2919		       CTLTYPE_INT, "nd6_umaxtries",
2920		       SYSCTL_DESCR("Number of unicast discovery attempts"),
2921		       NULL, 0, &nd6_umaxtries, 0,
2922		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2923		       ICMPV6CTL_ND6_UMAXTRIES, CTL_EOL);
2924	sysctl_createv(clog, 0, NULL, NULL,
2925		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2926		       CTLTYPE_INT, "nd6_mmaxtries",
2927		       SYSCTL_DESCR("Number of multicast discovery attempts"),
2928		       NULL, 0, &nd6_mmaxtries, 0,
2929		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2930		       ICMPV6CTL_ND6_MMAXTRIES, CTL_EOL);
2931	sysctl_createv(clog, 0, NULL, NULL,
2932		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2933		       CTLTYPE_INT, "nd6_useloopback",
2934		       SYSCTL_DESCR("Use loopback interface for local traffic"),
2935		       NULL, 0, &nd6_useloopback, 0,
2936		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2937		       ICMPV6CTL_ND6_USELOOPBACK, CTL_EOL);
2938#if 0 /* obsoleted */
2939	sysctl_createv(clog, 0, NULL, NULL,
2940		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2941		       CTLTYPE_INT, "nd6_proxyall", NULL,
2942		       NULL, 0, &nd6_proxyall, 0,
2943		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2944		       ICMPV6CTL_ND6_PROXYALL, CTL_EOL);
2945#endif
2946	sysctl_createv(clog, 0, NULL, NULL,
2947		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2948		       CTLTYPE_INT, "nodeinfo",
2949		       SYSCTL_DESCR("Respond to node information requests"),
2950		       NULL, 0, &icmp6_nodeinfo, 0,
2951		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2952		       ICMPV6CTL_NODEINFO, CTL_EOL);
2953	sysctl_createv(clog, 0, NULL, NULL,
2954		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2955		       CTLTYPE_INT, "errppslimit",
2956		       SYSCTL_DESCR("Maximum ICMP errors sent per second"),
2957		       NULL, 0, &icmp6errppslim, 0,
2958		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2959		       ICMPV6CTL_ERRPPSLIMIT, CTL_EOL);
2960	sysctl_createv(clog, 0, NULL, NULL,
2961		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2962		       CTLTYPE_INT, "nd6_maxnudhint",
2963		       SYSCTL_DESCR("Maximum neighbor unreachable hint count"),
2964		       NULL, 0, &nd6_maxnudhint, 0,
2965		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2966		       ICMPV6CTL_ND6_MAXNUDHINT, CTL_EOL);
2967	sysctl_createv(clog, 0, NULL, NULL,
2968		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2969		       CTLTYPE_INT, "mtudisc_hiwat",
2970		       SYSCTL_DESCR("Low mark on MTU Discovery route timers"),
2971		       NULL, 0, &icmp6_mtudisc_hiwat, 0,
2972		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2973		       ICMPV6CTL_MTUDISC_HIWAT, CTL_EOL);
2974	sysctl_createv(clog, 0, NULL, NULL,
2975		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2976		       CTLTYPE_INT, "mtudisc_lowat",
2977		       SYSCTL_DESCR("Low mark on MTU Discovery route timers"),
2978		       NULL, 0, &icmp6_mtudisc_lowat, 0,
2979		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2980		       ICMPV6CTL_MTUDISC_LOWAT, CTL_EOL);
2981	sysctl_createv(clog, 0, NULL, NULL,
2982		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2983		       CTLTYPE_INT, "nd6_debug",
2984		       SYSCTL_DESCR("Enable neighbor discovery debug output"),
2985		       NULL, 0, &nd6_debug, 0,
2986		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2987		       ICMPV6CTL_ND6_DEBUG, CTL_EOL);
2988	sysctl_createv(clog, 0, NULL, NULL,
2989		       CTLFLAG_PERMANENT,
2990		       CTLTYPE_STRUCT, "nd6_drlist",
2991		       SYSCTL_DESCR("Default router list"),
2992		       sysctl_net_inet6_icmp6_nd6, 0, NULL, 0,
2993		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2994		       ICMPV6CTL_ND6_DRLIST, CTL_EOL);
2995	sysctl_createv(clog, 0, NULL, NULL,
2996		       CTLFLAG_PERMANENT,
2997		       CTLTYPE_STRUCT, "nd6_prlist",
2998		       SYSCTL_DESCR("Prefix list"),
2999		       sysctl_net_inet6_icmp6_nd6, 0, NULL, 0,
3000		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
3001		       ICMPV6CTL_ND6_PRLIST, CTL_EOL);
3002}
3003