xref: /dragonfly/sys/netinet6/icmp6.c (revision 8a0bcd56)
1 /*	$FreeBSD: src/sys/netinet6/icmp6.c,v 1.6.2.13 2003/05/06 06:46:58 suz Exp $	*/
2 /*	$DragonFly: src/sys/netinet6/icmp6.c,v 1.31 2008/10/27 02:56:30 sephe Exp $	*/
3 /*	$KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $	*/
4 
5 /*
6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the project nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 /*
35  * Copyright (c) 1982, 1986, 1988, 1993
36  *	The Regents of the University of California.  All rights reserved.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 3. All advertising materials mentioning features or use of this software
47  *    must display the following acknowledgement:
48  *	This product includes software developed by the University of
49  *	California, Berkeley and its contributors.
50  * 4. Neither the name of the University nor the names of its contributors
51  *    may be used to endorse or promote products derived from this software
52  *    without specific prior written permission.
53  *
54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
64  * SUCH DAMAGE.
65  *
66  *	@(#)ip_icmp.c	8.2 (Berkeley) 1/4/94
67  */
68 
69 #include "opt_inet.h"
70 #include "opt_inet6.h"
71 #include "opt_ipsec.h"
72 
73 #include <sys/param.h>
74 #include <sys/systm.h>
75 #include <sys/malloc.h>
76 #include <sys/mbuf.h>
77 #include <sys/protosw.h>
78 #include <sys/socket.h>
79 #include <sys/socketvar.h>
80 #include <sys/socketops.h>
81 #include <sys/time.h>
82 #include <sys/kernel.h>
83 #include <sys/syslog.h>
84 #include <sys/domain.h>
85 
86 #include <sys/thread2.h>
87 #include <sys/msgport2.h>
88 
89 #include <net/if.h>
90 #include <net/route.h>
91 #include <net/if_dl.h>
92 #include <net/if_types.h>
93 
94 #include <netinet/in.h>
95 #include <netinet/in_var.h>
96 #include <netinet/ip6.h>
97 #include <netinet6/ip6_var.h>
98 #include <netinet/icmp6.h>
99 #include <netinet6/mld6_var.h>
100 #include <netinet/in_pcb.h>
101 #include <netinet6/in6_pcb.h>
102 #include <netinet6/nd6.h>
103 #include <netinet6/in6_ifattach.h>
104 #include <netinet6/ip6protosw.h>
105 
106 #ifdef IPSEC
107 #include <netinet6/ipsec.h>
108 #include <netproto/key/key.h>
109 #endif
110 
111 #ifdef FAST_IPSEC
112 #include <netproto/ipsec/ipsec.h>
113 #include <netproto/ipsec/key.h>
114 #define	IPSEC
115 #endif
116 
117 #include <net/net_osdep.h>
118 
119 #ifdef HAVE_NRL_INPCB
120 /* inpcb members */
121 #define in6pcb		inpcb
122 #define in6p_laddr	inp_laddr6
123 #define in6p_faddr	inp_faddr6
124 #define in6p_icmp6filt	inp_icmp6filt
125 #define in6p_route	inp_route
126 #define in6p_socket	inp_socket
127 #define in6p_flags	inp_flags
128 #define in6p_moptions	inp_moptions6
129 #define in6p_outputopts	inp_outputopts6
130 #define in6p_ip6	inp_ipv6
131 #define in6p_flowinfo	inp_flowinfo
132 #define in6p_sp		inp_sp
133 #define in6p_next	inp_next
134 #define in6p_prev	inp_prev
135 /* function names */
136 #define in6_pcbdetach	in_pcbdetach
137 #define in6_rtchange	in_rtchange
138 
139 /*
140  * for KAME src sync over BSD*'s. XXX: FreeBSD (>=3) are VERY different from
141  * others...
142  */
143 #define in6p_ip6_nxt	inp_ipv6.ip6_nxt
144 #endif
145 
146 /*
147  * ppratecheck() is available, so define it here.
148  */
149 #define	HAVE_PPSRATECHECK
150 
151 extern struct domain inet6domain;
152 extern struct protosw inet6sw[];
153 extern u_char ip6_protox[];
154 
155 struct icmp6stat icmp6stat;
156 
157 extern struct inpcbinfo ripcbinfo;
158 extern int icmp6errppslim;
159 static int icmp6errpps_count = 0;
160 static struct timeval icmp6errppslim_last;
161 extern int icmp6_nodeinfo;
162 
163 static void icmp6_errcount (struct icmp6errstat *, int, int);
164 static int icmp6_rip6_input (struct mbuf **, int);
165 static int icmp6_ratelimit (const struct in6_addr *, const int, const int);
166 static const char *icmp6_redirect_diag (struct in6_addr *,
167 	struct in6_addr *, struct in6_addr *);
168 #ifndef HAVE_PPSRATECHECK
169 static int ppsratecheck (struct timeval *, int *, int);
170 #endif
171 static struct mbuf *ni6_input (struct mbuf *, int);
172 static struct mbuf *ni6_nametodns (const char *, int, int);
173 static int ni6_dnsmatch (const char *, int, const char *, int);
174 static int ni6_addrs (struct icmp6_nodeinfo *, struct mbuf *,
175 			  struct ifnet **, char *);
176 static int ni6_store_addrs (struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
177 				struct ifnet *, int);
178 static int icmp6_notify_error (struct mbuf *, int, int, int);
179 
180 #ifdef COMPAT_RFC1885
181 static struct route_in6 icmp6_reflect_rt;
182 #endif
183 
184 
185 void
186 icmp6_init(void)
187 {
188 	mld6_init();
189 }
190 
191 static void
192 icmp6_errcount(struct icmp6errstat *stat, int type, int code)
193 {
194 	switch (type) {
195 	case ICMP6_DST_UNREACH:
196 		switch (code) {
197 		case ICMP6_DST_UNREACH_NOROUTE:
198 			stat->icp6errs_dst_unreach_noroute++;
199 			return;
200 		case ICMP6_DST_UNREACH_ADMIN:
201 			stat->icp6errs_dst_unreach_admin++;
202 			return;
203 		case ICMP6_DST_UNREACH_BEYONDSCOPE:
204 			stat->icp6errs_dst_unreach_beyondscope++;
205 			return;
206 		case ICMP6_DST_UNREACH_ADDR:
207 			stat->icp6errs_dst_unreach_addr++;
208 			return;
209 		case ICMP6_DST_UNREACH_NOPORT:
210 			stat->icp6errs_dst_unreach_noport++;
211 			return;
212 		}
213 		break;
214 	case ICMP6_PACKET_TOO_BIG:
215 		stat->icp6errs_packet_too_big++;
216 		return;
217 	case ICMP6_TIME_EXCEEDED:
218 		switch (code) {
219 		case ICMP6_TIME_EXCEED_TRANSIT:
220 			stat->icp6errs_time_exceed_transit++;
221 			return;
222 		case ICMP6_TIME_EXCEED_REASSEMBLY:
223 			stat->icp6errs_time_exceed_reassembly++;
224 			return;
225 		}
226 		break;
227 	case ICMP6_PARAM_PROB:
228 		switch (code) {
229 		case ICMP6_PARAMPROB_HEADER:
230 			stat->icp6errs_paramprob_header++;
231 			return;
232 		case ICMP6_PARAMPROB_NEXTHEADER:
233 			stat->icp6errs_paramprob_nextheader++;
234 			return;
235 		case ICMP6_PARAMPROB_OPTION:
236 			stat->icp6errs_paramprob_option++;
237 			return;
238 		}
239 		break;
240 	case ND_REDIRECT:
241 		stat->icp6errs_redirect++;
242 		return;
243 	}
244 	stat->icp6errs_unknown++;
245 }
246 
247 /*
248  * Generate an error packet of type error in response to bad IP6 packet.
249  */
250 void
251 icmp6_error(struct mbuf *m, int type, int code, int param)
252 {
253 	struct ip6_hdr *oip6, *nip6;
254 	struct icmp6_hdr *icmp6;
255 	u_int preplen;
256 	int off;
257 	int nxt;
258 
259 	icmp6stat.icp6s_error++;
260 
261 	/* count per-type-code statistics */
262 	icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code);
263 
264 #ifdef M_DECRYPTED	/*not openbsd*/
265 	if (m->m_flags & M_DECRYPTED) {
266 		icmp6stat.icp6s_canterror++;
267 		goto freeit;
268 	}
269 #endif
270 
271 #ifndef PULLDOWN_TEST
272 	IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
273 #else
274 	if (m->m_len < sizeof(struct ip6_hdr)) {
275 		m = m_pullup(m, sizeof(struct ip6_hdr));
276 		if (m == NULL)
277 			return;
278 	}
279 #endif
280 	oip6 = mtod(m, struct ip6_hdr *);
281 
282 	/*
283 	 * Multicast destination check. For unrecognized option errors,
284 	 * this check has already done in ip6_unknown_opt(), so we can
285 	 * check only for other errors.
286 	 */
287 	if ((m->m_flags & (M_BCAST|M_MCAST) ||
288 	     IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
289 	    (type != ICMP6_PACKET_TOO_BIG &&
290 	     (type != ICMP6_PARAM_PROB ||
291 	      code != ICMP6_PARAMPROB_OPTION)))
292 		goto freeit;
293 
294 	/* Source address check. XXX: the case of anycast source? */
295 	if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
296 	    IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
297 		goto freeit;
298 
299 	/*
300 	 * If we are about to send ICMPv6 against ICMPv6 error/redirect,
301 	 * don't do it.
302 	 */
303 	nxt = -1;
304 	off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
305 	if (off >= 0 && nxt == IPPROTO_ICMPV6) {
306 		struct icmp6_hdr *icp;
307 
308 #ifndef PULLDOWN_TEST
309 		IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
310 		icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
311 #else
312 		IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
313 			sizeof(*icp));
314 		if (icp == NULL) {
315 			icmp6stat.icp6s_tooshort++;
316 			return;
317 		}
318 #endif
319 		if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
320 		    icp->icmp6_type == ND_REDIRECT) {
321 			/*
322 			 * ICMPv6 error
323 			 * Special case: for redirect (which is
324 			 * informational) we must not send icmp6 error.
325 			 */
326 			icmp6stat.icp6s_canterror++;
327 			goto freeit;
328 		} else {
329 			/* ICMPv6 informational - send the error */
330 		}
331 	} else {
332 		/* non-ICMPv6 - send the error */
333 	}
334 
335 	oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
336 
337 	/* Finally, do rate limitation check. */
338 	if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
339 		icmp6stat.icp6s_toofreq++;
340 		goto freeit;
341 	}
342 
343 	/*
344 	 * OK, ICMP6 can be generated.
345 	 */
346 
347 	if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
348 		m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
349 
350 	preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
351 	M_PREPEND(m, preplen, MB_DONTWAIT);
352 	if (m && m->m_len < preplen)
353 		m = m_pullup(m, preplen);
354 	if (m == NULL) {
355 		nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
356 		return;
357 	}
358 
359 	nip6 = mtod(m, struct ip6_hdr *);
360 	nip6->ip6_src  = oip6->ip6_src;
361 	nip6->ip6_dst  = oip6->ip6_dst;
362 
363 	if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
364 		oip6->ip6_src.s6_addr16[1] = 0;
365 	if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
366 		oip6->ip6_dst.s6_addr16[1] = 0;
367 
368 	icmp6 = (struct icmp6_hdr *)(nip6 + 1);
369 	icmp6->icmp6_type = type;
370 	icmp6->icmp6_code = code;
371 	icmp6->icmp6_pptr = htonl((u_int32_t)param);
372 
373 	/*
374 	 * icmp6_reflect() is designed to be in the input path.
375 	 * icmp6_error() can be called from both input and outut path,
376 	 * and if we are in output path rcvif could contain bogus value.
377 	 * clear m->m_pkthdr.rcvif for safety, we should have enough scope
378 	 * information in ip header (nip6).
379 	 */
380 	m->m_pkthdr.rcvif = NULL;
381 
382 	icmp6stat.icp6s_outhist[type]++;
383 	icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
384 
385 	return;
386 
387 freeit:
388 	/*
389 	 * If we can't tell wheter or not we can generate ICMP6, free it.
390 	 */
391 	m_freem(m);
392 }
393 
394 /*
395  * Process a received ICMP6 message.
396  */
397 int
398 icmp6_input(struct mbuf **mp, int *offp, int proto)
399 {
400 	struct mbuf *m = *mp, *n;
401 	struct ip6_hdr *ip6, *nip6;
402 	struct icmp6_hdr *icmp6, *nicmp6;
403 	int off = *offp;
404 	int icmp6len = m->m_pkthdr.len - *offp;
405 	int code, sum, noff;
406 
407 #ifndef PULLDOWN_TEST
408 	IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
409 	/* m might change if M_LOOP.  So, call mtod after this */
410 #endif
411 
412 	/*
413 	 * Locate icmp6 structure in mbuf, and check
414 	 * that not corrupted and of at least minimum length
415 	 */
416 
417 	ip6 = mtod(m, struct ip6_hdr *);
418 	if (icmp6len < sizeof(struct icmp6_hdr)) {
419 		icmp6stat.icp6s_tooshort++;
420 		goto freeit;
421 	}
422 
423 	/*
424 	 * calculate the checksum
425 	 */
426 #ifndef PULLDOWN_TEST
427 	icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
428 #else
429 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
430 	if (icmp6 == NULL) {
431 		icmp6stat.icp6s_tooshort++;
432 		return IPPROTO_DONE;
433 	}
434 #endif
435 	code = icmp6->icmp6_code;
436 
437 	if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
438 		nd6log((LOG_ERR,
439 		    "ICMP6 checksum error(%d|%x) %s\n",
440 		    icmp6->icmp6_type, sum, ip6_sprintf(&ip6->ip6_src)));
441 		icmp6stat.icp6s_checksum++;
442 		goto freeit;
443 	}
444 
445 	if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
446 		/*
447 		 * Deliver very specific ICMP6 type only.
448 		 * This is important to deilver TOOBIG.  Otherwise PMTUD
449 		 * will not work.
450 		 */
451 		switch (icmp6->icmp6_type) {
452 		case ICMP6_DST_UNREACH:
453 		case ICMP6_PACKET_TOO_BIG:
454 		case ICMP6_TIME_EXCEEDED:
455 			break;
456 		default:
457 			goto freeit;
458 		}
459 	}
460 
461 	icmp6stat.icp6s_inhist[icmp6->icmp6_type]++;
462 	icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg);
463 	if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
464 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
465 
466 	switch (icmp6->icmp6_type) {
467 	case ICMP6_DST_UNREACH:
468 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach);
469 		switch (code) {
470 		case ICMP6_DST_UNREACH_NOROUTE:
471 			code = PRC_UNREACH_NET;
472 			break;
473 		case ICMP6_DST_UNREACH_ADMIN:
474 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib);
475 			code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
476 			break;
477 		case ICMP6_DST_UNREACH_ADDR:
478 			code = PRC_HOSTDEAD;
479 			break;
480 #ifdef COMPAT_RFC1885
481 		case ICMP6_DST_UNREACH_NOTNEIGHBOR:
482 			code = PRC_UNREACH_SRCFAIL;
483 			break;
484 #else
485 		case ICMP6_DST_UNREACH_BEYONDSCOPE:
486 			/* I mean "source address was incorrect." */
487 			code = PRC_PARAMPROB;
488 			break;
489 #endif
490 		case ICMP6_DST_UNREACH_NOPORT:
491 			code = PRC_UNREACH_PORT;
492 			break;
493 		default:
494 			goto badcode;
495 		}
496 		goto deliver;
497 		break;
498 
499 	case ICMP6_PACKET_TOO_BIG:
500 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig);
501 		if (code != 0)
502 			goto badcode;
503 
504 		code = PRC_MSGSIZE;
505 
506 		/*
507 		 * Updating the path MTU will be done after examining
508 		 * intermediate extension headers.
509 		 */
510 		goto deliver;
511 		break;
512 
513 	case ICMP6_TIME_EXCEEDED:
514 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed);
515 		switch (code) {
516 		case ICMP6_TIME_EXCEED_TRANSIT:
517 		case ICMP6_TIME_EXCEED_REASSEMBLY:
518 			code += PRC_TIMXCEED_INTRANS;
519 			break;
520 		default:
521 			goto badcode;
522 		}
523 		goto deliver;
524 		break;
525 
526 	case ICMP6_PARAM_PROB:
527 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob);
528 		switch (code) {
529 		case ICMP6_PARAMPROB_NEXTHEADER:
530 			code = PRC_UNREACH_PROTOCOL;
531 			break;
532 		case ICMP6_PARAMPROB_HEADER:
533 		case ICMP6_PARAMPROB_OPTION:
534 			code = PRC_PARAMPROB;
535 			break;
536 		default:
537 			goto badcode;
538 		}
539 		goto deliver;
540 		break;
541 
542 	case ICMP6_ECHO_REQUEST:
543 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo);
544 		if (code != 0)
545 			goto badcode;
546 		if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
547 			/* Give up remote */
548 			break;
549 		}
550 		if ((n->m_flags & M_EXT) ||
551 		    n->m_len < off + sizeof(struct icmp6_hdr)) {
552 			struct mbuf *n0 = n;
553 			const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
554 			int n0len;
555 
556 			/*
557 			 * Prepare an internal mbuf. m_pullup() doesn't
558 			 * always copy the length we specified.
559 			 */
560 			if (maxlen >= MCLBYTES) {
561 				/* Give up remote */
562 				m_freem(n0);
563 				break;
564 			}
565 			n = m_getb(maxlen, MB_DONTWAIT, n0->m_type, M_PKTHDR);
566 			if (n == NULL) {
567 				/* Give up remote */
568 				m_freem(n0);
569 				break;
570 			}
571 			n0len = n0->m_pkthdr.len;	/* save for use below */
572 			M_MOVE_PKTHDR(n, n0);
573 			/*
574 			 * Copy IPv6 and ICMPv6 only.
575 			 */
576 			nip6 = mtod(n, struct ip6_hdr *);
577 			bcopy(ip6, nip6, sizeof(struct ip6_hdr));
578 			nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
579 			bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
580 			noff = sizeof(struct ip6_hdr);
581 			/* new mbuf contains only ipv6+icmpv6 headers */
582 			n->m_len = noff + sizeof(struct icmp6_hdr);
583 			/*
584 			 * Adjust mbuf. ip6_plen will be adjusted in
585 			 * ip6_output().
586 			 */
587 			m_adj(n0, off + sizeof(struct icmp6_hdr));
588 			/* recalculate complete packet size */
589 			n->m_pkthdr.len = n0len + (noff - off);
590 			n->m_next = n0;
591 		} else {
592 			nip6 = mtod(n, struct ip6_hdr *);
593 			nicmp6 = (struct icmp6_hdr *)((caddr_t)nip6 + off);
594 			noff = off;
595 		}
596 		nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
597 		nicmp6->icmp6_code = 0;
598 		if (n) {
599 			icmp6stat.icp6s_reflect++;
600 			icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++;
601 			icmp6_reflect(n, noff);
602 		}
603 		break;
604 
605 	case ICMP6_ECHO_REPLY:
606 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply);
607 		if (code != 0)
608 			goto badcode;
609 		break;
610 
611 	case MLD_LISTENER_QUERY:
612 	case MLD_LISTENER_REPORT:
613 		if (icmp6len < sizeof(struct mld_hdr))
614 			goto badlen;
615 		if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */
616 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery);
617 		else
618 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport);
619 		if ((n = m_copym(m, 0, M_COPYALL, MB_DONTWAIT)) == NULL) {
620 			/* give up local */
621 			mld6_input(m, off);
622 			m = NULL;
623 			goto freeit;
624 		}
625 		mld6_input(n, off);
626 		/* m stays. */
627 		break;
628 
629 	case MLD_LISTENER_DONE:
630 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone);
631 		if (icmp6len < sizeof(struct mld_hdr))	/* necessary? */
632 			goto badlen;
633 		break;		/* nothing to be done in kernel */
634 
635 	case MLD_MTRACE_RESP:
636 	case MLD_MTRACE:
637 		/* XXX: these two are experimental.  not officially defind. */
638 		/* XXX: per-interface statistics? */
639 		break;		/* just pass it to applications */
640 
641 	case ICMP6_WRUREQUEST:	/* ICMP6_FQDN_QUERY */
642 	    {
643 		enum { WRU, FQDN } mode;
644 
645 		if (!icmp6_nodeinfo)
646 			break;
647 
648 		if (icmp6len == sizeof(struct icmp6_hdr) + 4)
649 			mode = WRU;
650 		else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
651 			mode = FQDN;
652 		else
653 			goto badlen;
654 
655 #define hostnamelen	strlen(hostname)
656 		if (mode == FQDN) {
657 #ifndef PULLDOWN_TEST
658 			IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
659 					 IPPROTO_DONE);
660 #endif
661 			n = m_copy(m, 0, M_COPYALL);
662 			if (n)
663 				n = ni6_input(n, off);
664 			/* XXX meaningless if n == NULL */
665 			noff = sizeof(struct ip6_hdr);
666 		} else {
667 			u_char *p;
668 			int maxlen, maxhlen;
669 
670 			if ((icmp6_nodeinfo & 5) != 5)
671 				break;
672 
673 			if (code != 0)
674 				goto badcode;
675 			maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
676 			if (maxlen >= MCLBYTES) {
677 				/* Give up remote */
678 				break;
679 			}
680 			n = m_getb(maxlen, MB_DONTWAIT, m->m_type, M_PKTHDR);
681 			if (n == NULL) {
682 				/* Give up remote */
683 				break;
684 			}
685 			if (!m_dup_pkthdr(n, m, MB_DONTWAIT)) {
686 				/*
687 				 * Previous code did a blind M_COPY_PKTHDR
688 				 * and said "just for rcvif".  If true, then
689 				 * we could tolerate the dup failing (due to
690 				 * the deep copy of the tag chain).  For now
691 				 * be conservative and just fail.
692 				 */
693 				m_free(n);
694 				break;
695 			}
696 			n->m_len = 0;
697 			maxhlen = M_TRAILINGSPACE(n) - maxlen;
698 			if (maxhlen > hostnamelen)
699 				maxhlen = hostnamelen;
700 			/*
701 			 * Copy IPv6 and ICMPv6 only.
702 			 */
703 			nip6 = mtod(n, struct ip6_hdr *);
704 			bcopy(ip6, nip6, sizeof(struct ip6_hdr));
705 			nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
706 			bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
707 			p = (u_char *)(nicmp6 + 1);
708 			bzero(p, 4);
709 			bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */
710 			noff = sizeof(struct ip6_hdr);
711 			n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
712 				sizeof(struct icmp6_hdr) + 4 + maxhlen;
713 			nicmp6->icmp6_type = ICMP6_WRUREPLY;
714 			nicmp6->icmp6_code = 0;
715 		}
716 #undef hostnamelen
717 		if (n) {
718 			icmp6stat.icp6s_reflect++;
719 			icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++;
720 			icmp6_reflect(n, noff);
721 		}
722 		break;
723 	    }
724 
725 	case ICMP6_WRUREPLY:
726 		if (code != 0)
727 			goto badcode;
728 		break;
729 
730 	case ND_ROUTER_SOLICIT:
731 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit);
732 		if (code != 0)
733 			goto badcode;
734 		if (icmp6len < sizeof(struct nd_router_solicit))
735 			goto badlen;
736 		if ((n = m_copym(m, 0, M_COPYALL, MB_DONTWAIT)) == NULL) {
737 			/* give up local */
738 			nd6_rs_input(m, off, icmp6len);
739 			m = NULL;
740 			goto freeit;
741 		}
742 		nd6_rs_input(n, off, icmp6len);
743 		/* m stays. */
744 		break;
745 
746 	case ND_ROUTER_ADVERT:
747 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert);
748 		if (code != 0)
749 			goto badcode;
750 		if (icmp6len < sizeof(struct nd_router_advert))
751 			goto badlen;
752 		if ((n = m_copym(m, 0, M_COPYALL, MB_DONTWAIT)) == NULL) {
753 			/* give up local */
754 			nd6_ra_input(m, off, icmp6len);
755 			m = NULL;
756 			goto freeit;
757 		}
758 		nd6_ra_input(n, off, icmp6len);
759 		/* m stays. */
760 		break;
761 
762 	case ND_NEIGHBOR_SOLICIT:
763 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit);
764 		if (code != 0)
765 			goto badcode;
766 		if (icmp6len < sizeof(struct nd_neighbor_solicit))
767 			goto badlen;
768 		if ((n = m_copym(m, 0, M_COPYALL, MB_DONTWAIT)) == NULL) {
769 			/* give up local */
770 			nd6_ns_input(m, off, icmp6len);
771 			m = NULL;
772 			goto freeit;
773 		}
774 		nd6_ns_input(n, off, icmp6len);
775 		/* m stays. */
776 		break;
777 
778 	case ND_NEIGHBOR_ADVERT:
779 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert);
780 		if (code != 0)
781 			goto badcode;
782 		if (icmp6len < sizeof(struct nd_neighbor_advert))
783 			goto badlen;
784 		if ((n = m_copym(m, 0, M_COPYALL, MB_DONTWAIT)) == NULL) {
785 			/* give up local */
786 			nd6_na_input(m, off, icmp6len);
787 			m = NULL;
788 			goto freeit;
789 		}
790 		nd6_na_input(n, off, icmp6len);
791 		/* m stays. */
792 		break;
793 
794 	case ND_REDIRECT:
795 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect);
796 		if (code != 0)
797 			goto badcode;
798 		if (icmp6len < sizeof(struct nd_redirect))
799 			goto badlen;
800 		if ((n = m_copym(m, 0, M_COPYALL, MB_DONTWAIT)) == NULL) {
801 			/* give up local */
802 			icmp6_redirect_input(m, off);
803 			m = NULL;
804 			goto freeit;
805 		}
806 		icmp6_redirect_input(n, off);
807 		/* m stays. */
808 		break;
809 
810 	case ICMP6_ROUTER_RENUMBERING:
811 		if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
812 		    code != ICMP6_ROUTER_RENUMBERING_RESULT)
813 			goto badcode;
814 		if (icmp6len < sizeof(struct icmp6_router_renum))
815 			goto badlen;
816 		break;
817 
818 	default:
819 		nd6log((LOG_DEBUG,
820 		    "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
821 		    icmp6->icmp6_type, ip6_sprintf(&ip6->ip6_src),
822 		    ip6_sprintf(&ip6->ip6_dst),
823 		    m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0));
824 		if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
825 			/* ICMPv6 error: MUST deliver it by spec... */
826 			code = PRC_NCMDS;
827 			/* deliver */
828 		} else {
829 			/* ICMPv6 informational: MUST not deliver */
830 			break;
831 		}
832 	deliver:
833 		if (icmp6_notify_error(m, off, icmp6len, code)) {
834 			/* In this case, m should've been freed. */
835 			return (IPPROTO_DONE);
836 		}
837 		break;
838 
839 	badcode:
840 		icmp6stat.icp6s_badcode++;
841 		break;
842 
843 	badlen:
844 		icmp6stat.icp6s_badlen++;
845 		break;
846 	}
847 
848 	/* deliver the packet to appropriate sockets */
849 	icmp6_rip6_input(&m, *offp);
850 
851 	return IPPROTO_DONE;
852 
853 freeit:
854 	m_freem(m);
855 	return IPPROTO_DONE;
856 }
857 
858 static int
859 icmp6_notify_error(struct mbuf *m, int off, int icmp6len, int code)
860 {
861 	struct icmp6_hdr *icmp6;
862 	struct ip6_hdr *eip6;
863 	u_int32_t notifymtu;
864 	struct sockaddr_in6 icmp6src, icmp6dst;
865 
866 	if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
867 		icmp6stat.icp6s_tooshort++;
868 		goto freeit;
869 	}
870 #ifndef PULLDOWN_TEST
871 	IP6_EXTHDR_CHECK(m, off,
872 			 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr),
873 			 -1);
874 	icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
875 #else
876 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
877 		       sizeof(*icmp6) + sizeof(struct ip6_hdr));
878 	if (icmp6 == NULL) {
879 		icmp6stat.icp6s_tooshort++;
880 		return (-1);
881 	}
882 #endif
883 	eip6 = (struct ip6_hdr *)(icmp6 + 1);
884 
885 	/* Detect the upper level protocol */
886 	{
887 		u_int8_t nxt = eip6->ip6_nxt;
888 		int eoff = off + sizeof(struct icmp6_hdr) +
889 			sizeof(struct ip6_hdr);
890 		struct ip6ctlparam ip6cp;
891 		struct in6_addr *finaldst = NULL;
892 		int icmp6type = icmp6->icmp6_type;
893 		struct ip6_frag *fh;
894 		struct ip6_rthdr *rth;
895 		int rthlen;
896 
897 		while (1) { /* XXX: should avoid infinite loop explicitly? */
898 			struct ip6_ext *eh;
899 
900 			switch (nxt) {
901 			case IPPROTO_HOPOPTS:
902 			case IPPROTO_DSTOPTS:
903 			case IPPROTO_AH:
904 #ifndef PULLDOWN_TEST
905 				IP6_EXTHDR_CHECK(m, 0, eoff +
906 						 sizeof(struct ip6_ext),
907 						 -1);
908 				eh = (struct ip6_ext *)(mtod(m, caddr_t)
909 							+ eoff);
910 #else
911 				IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
912 					       eoff, sizeof(*eh));
913 				if (eh == NULL) {
914 					icmp6stat.icp6s_tooshort++;
915 					return (-1);
916 				}
917 #endif
918 
919 				if (nxt == IPPROTO_AH)
920 					eoff += (eh->ip6e_len + 2) << 2;
921 				else
922 					eoff += (eh->ip6e_len + 1) << 3;
923 				nxt = eh->ip6e_nxt;
924 				break;
925 			case IPPROTO_ROUTING:
926 				/*
927 				 * When the erroneous packet contains a
928 				 * routing header, we should examine the
929 				 * header to determine the final destination.
930 				 * Otherwise, we can't properly update
931 				 * information that depends on the final
932 				 * destination (e.g. path MTU).
933 				 */
934 #ifndef PULLDOWN_TEST
935 				IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth),
936 						 -1);
937 				rth = (struct ip6_rthdr *)(mtod(m, caddr_t)
938 							   + eoff);
939 #else
940 				IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
941 					       eoff, sizeof(*rth));
942 				if (rth == NULL) {
943 					icmp6stat.icp6s_tooshort++;
944 					return (-1);
945 				}
946 #endif
947 				rthlen = (rth->ip6r_len + 1) << 3;
948 				eoff += rthlen;
949 				nxt = rth->ip6r_nxt;
950 				break;
951 			case IPPROTO_FRAGMENT:
952 #ifndef PULLDOWN_TEST
953 				IP6_EXTHDR_CHECK(m, 0, eoff +
954 						 sizeof(struct ip6_frag),
955 						 -1);
956 				fh = (struct ip6_frag *)(mtod(m, caddr_t)
957 							 + eoff);
958 #else
959 				IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
960 					       eoff, sizeof(*fh));
961 				if (fh == NULL) {
962 					icmp6stat.icp6s_tooshort++;
963 					return (-1);
964 				}
965 #endif
966 				/*
967 				 * Data after a fragment header is meaningless
968 				 * unless it is the first fragment, but
969 				 * we'll go to the notify label for path MTU
970 				 * discovery.
971 				 */
972 				if (fh->ip6f_offlg & IP6F_OFF_MASK)
973 					goto notify;
974 
975 				eoff += sizeof(struct ip6_frag);
976 				nxt = fh->ip6f_nxt;
977 				break;
978 			default:
979 				/*
980 				 * This case includes ESP and the No Next
981 				 * Header.  In such cases going to the notify
982 				 * label does not have any meaning
983 				 * (i.e. pr_ctlinput will be NULL), but we go
984 				 * anyway since we might have to update
985 				 * path MTU information.
986 				 */
987 				goto notify;
988 			}
989 		}
990 	  notify:
991 #ifndef PULLDOWN_TEST
992 		icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
993 #else
994 		IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
995 			       sizeof(*icmp6) + sizeof(struct ip6_hdr));
996 		if (icmp6 == NULL) {
997 			icmp6stat.icp6s_tooshort++;
998 			return (-1);
999 		}
1000 #endif
1001 
1002 		eip6 = (struct ip6_hdr *)(icmp6 + 1);
1003 		bzero(&icmp6dst, sizeof(icmp6dst));
1004 		icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1005 		icmp6dst.sin6_family = AF_INET6;
1006 		if (finaldst == NULL)
1007 			icmp6dst.sin6_addr = eip6->ip6_dst;
1008 		else
1009 			icmp6dst.sin6_addr = *finaldst;
1010 		icmp6dst.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
1011 							  &icmp6dst.sin6_addr);
1012 		if (in6_embedscope(&icmp6dst.sin6_addr, &icmp6dst,
1013 				   NULL, NULL)) {
1014 			/* should be impossbile */
1015 			nd6log((LOG_DEBUG,
1016 			    "icmp6_notify_error: in6_embedscope failed\n"));
1017 			goto freeit;
1018 		}
1019 
1020 		/*
1021 		 * retrieve parameters from the inner IPv6 header, and convert
1022 		 * them into sockaddr structures.
1023 		 */
1024 		bzero(&icmp6src, sizeof(icmp6src));
1025 		icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1026 		icmp6src.sin6_family = AF_INET6;
1027 		icmp6src.sin6_addr = eip6->ip6_src;
1028 		icmp6src.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
1029 							  &icmp6src.sin6_addr);
1030 		if (in6_embedscope(&icmp6src.sin6_addr, &icmp6src,
1031 				   NULL, NULL)) {
1032 			/* should be impossbile */
1033 			nd6log((LOG_DEBUG,
1034 			    "icmp6_notify_error: in6_embedscope failed\n"));
1035 			goto freeit;
1036 		}
1037 		icmp6src.sin6_flowinfo =
1038 			(eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1039 
1040 		if (finaldst == NULL)
1041 			finaldst = &eip6->ip6_dst;
1042 		ip6cp.ip6c_m = m;
1043 		ip6cp.ip6c_icmp6 = icmp6;
1044 		ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1045 		ip6cp.ip6c_off = eoff;
1046 		ip6cp.ip6c_finaldst = finaldst;
1047 		ip6cp.ip6c_src = &icmp6src;
1048 		ip6cp.ip6c_nxt = nxt;
1049 
1050 		if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1051 			notifymtu = ntohl(icmp6->icmp6_mtu);
1052 			ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1053 			icmp6_mtudisc_update(&ip6cp, 1);	/*XXX*/
1054 		}
1055 
1056 		so_pru_ctlinput(
1057 			(struct protosw *)&inet6sw[ip6_protox[nxt]],
1058 			code, (struct sockaddr *)&icmp6dst, &ip6cp);
1059 	}
1060 	return (0);
1061 
1062 freeit:
1063 	m_freem(m);
1064 	return (-1);
1065 }
1066 
1067 void
1068 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1069 {
1070 	struct in6_addr *dst = ip6cp->ip6c_finaldst;
1071 	struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1072 	struct mbuf *m = ip6cp->ip6c_m;	/* will be necessary for scope issue */
1073 	u_int mtu = ntohl(icmp6->icmp6_mtu);
1074 	struct rtentry *rt = NULL;
1075 	struct sockaddr_in6 sin6;
1076 
1077 	if (!validated)
1078 		return;
1079 
1080 	bzero(&sin6, sizeof(sin6));
1081 	sin6.sin6_family = PF_INET6;
1082 	sin6.sin6_len = sizeof(struct sockaddr_in6);
1083 	sin6.sin6_addr = *dst;
1084 	/* XXX normally, this won't happen */
1085 	if (IN6_IS_ADDR_LINKLOCAL(dst)) {
1086 		sin6.sin6_addr.s6_addr16[1] =
1087 		    htons(m->m_pkthdr.rcvif->if_index);
1088 	}
1089 	/* sin6.sin6_scope_id = XXX: should be set if DST is a scoped addr */
1090 	rt = rtpurelookup((struct sockaddr *)&sin6);
1091 	if (rt != NULL && (rt->rt_flags & RTF_HOST) &&
1092 	    !(rt->rt_rmx.rmx_locks & RTV_MTU)) {
1093 		if (mtu < IPV6_MMTU) {				/* XXX */
1094 			rt->rt_rmx.rmx_locks |= RTV_MTU;
1095 		} else if (mtu < rt->rt_ifp->if_mtu &&
1096 			   rt->rt_rmx.rmx_mtu > mtu) {
1097 			icmp6stat.icp6s_pmtuchg++;
1098 			rt->rt_rmx.rmx_mtu = mtu;
1099 		}
1100 	}
1101 	if (rt)
1102 		--rt->rt_refcnt;
1103 }
1104 
1105 /*
1106  * Process a Node Information Query packet, based on
1107  * draft-ietf-ipngwg-icmp-name-lookups-07.
1108  *
1109  * Spec incompatibilities:
1110  * - IPv6 Subject address handling
1111  * - IPv4 Subject address handling support missing
1112  * - Proxy reply (answer even if it's not for me)
1113  * - joins NI group address at in6_ifattach() time only, does not cope
1114  *   with hostname changes by sethostname(3)
1115  */
1116 #define hostnamelen	strlen(hostname)
1117 static struct mbuf *
1118 ni6_input(struct mbuf *m, int off)
1119 {
1120 	struct icmp6_nodeinfo *ni6, *nni6;
1121 	struct mbuf *n = NULL;
1122 	u_int16_t qtype;
1123 	int subjlen;
1124 	int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1125 	struct ni_reply_fqdn *fqdn;
1126 	int addrs;		/* for NI_QTYPE_NODEADDR */
1127 	struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1128 	struct sockaddr_in6 sin6; /* double meaning; ip6_dst and subjectaddr */
1129 	struct sockaddr_in6 sin6_d; /* XXX: we should retrieve this from m_aux */
1130 	struct ip6_hdr *ip6;
1131 	int oldfqdn = 0;	/* if 1, return pascal string (03 draft) */
1132 	char *subj = NULL;
1133 	struct in6_ifaddr *ia6 = NULL;
1134 
1135 	ip6 = mtod(m, struct ip6_hdr *);
1136 #ifndef PULLDOWN_TEST
1137 	ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1138 #else
1139 	IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1140 	if (ni6 == NULL) {
1141 		/* m is already reclaimed */
1142 		return NULL;
1143 	}
1144 #endif
1145 
1146 	/*
1147 	 * Validate IPv6 destination address.
1148 	 *
1149 	 * The Responder must discard the Query without further processing
1150 	 * unless it is one of the Responder's unicast or anycast addresses, or
1151 	 * a link-local scope multicast address which the Responder has joined.
1152 	 * [icmp-name-lookups-07, Section 4.]
1153 	 */
1154 	bzero(&sin6, sizeof(sin6));
1155 	sin6.sin6_family = AF_INET6;
1156 	sin6.sin6_len = sizeof(struct sockaddr_in6);
1157 	bcopy(&ip6->ip6_dst, &sin6.sin6_addr, sizeof(sin6.sin6_addr));
1158 	/* XXX scopeid */
1159 	if ((ia6 = (struct in6_ifaddr *)ifa_ifwithaddr((struct sockaddr *)&sin6)) != NULL) {
1160 		/* unicast/anycast, fine */
1161 		if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1162 		    (icmp6_nodeinfo & 4) == 0) {
1163 			nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1164 				"a temporary address in %s:%d",
1165 			       __FILE__, __LINE__));
1166 			goto bad;
1167 		}
1168 	} else if (IN6_IS_ADDR_MC_LINKLOCAL(&sin6.sin6_addr))
1169 		; /* link-local multicast, fine */
1170 	else
1171 		goto bad;
1172 
1173 	/* validate query Subject field. */
1174 	qtype = ntohs(ni6->ni_qtype);
1175 	subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1176 	switch (qtype) {
1177 	case NI_QTYPE_NOOP:
1178 	case NI_QTYPE_SUPTYPES:
1179 		/* 07 draft */
1180 		if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1181 			break;
1182 		/* FALLTHROUGH */
1183 	case NI_QTYPE_FQDN:
1184 	case NI_QTYPE_NODEADDR:
1185 		switch (ni6->ni_code) {
1186 		case ICMP6_NI_SUBJ_IPV6:
1187 #if ICMP6_NI_SUBJ_IPV6 != 0
1188 		case 0:
1189 #endif
1190 			/*
1191 			 * backward compatibility - try to accept 03 draft
1192 			 * format, where no Subject is present.
1193 			 */
1194 			if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1195 			    subjlen == 0) {
1196 				oldfqdn++;
1197 				break;
1198 			}
1199 #if ICMP6_NI_SUBJ_IPV6 != 0
1200 			if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1201 				goto bad;
1202 #endif
1203 
1204 			if (subjlen != sizeof(sin6.sin6_addr))
1205 				goto bad;
1206 
1207 			/*
1208 			 * Validate Subject address.
1209 			 *
1210 			 * Not sure what exactly "address belongs to the node"
1211 			 * means in the spec, is it just unicast, or what?
1212 			 *
1213 			 * At this moment we consider Subject address as
1214 			 * "belong to the node" if the Subject address equals
1215 			 * to the IPv6 destination address; validation for
1216 			 * IPv6 destination address should have done enough
1217 			 * check for us.
1218 			 *
1219 			 * We do not do proxy at this moment.
1220 			 */
1221 			/* m_pulldown instead of copy? */
1222 			m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1223 			    subjlen, (caddr_t)&sin6.sin6_addr);
1224 			sin6.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
1225 							      &sin6.sin6_addr);
1226 			in6_embedscope(&sin6.sin6_addr, &sin6, NULL, NULL);
1227 			bzero(&sin6_d, sizeof(sin6_d));
1228 			sin6_d.sin6_family = AF_INET6; /* not used, actually */
1229 			sin6_d.sin6_len = sizeof(sin6_d); /* ditto */
1230 			sin6_d.sin6_addr = ip6->ip6_dst;
1231 			sin6_d.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
1232 								&ip6->ip6_dst);
1233 			in6_embedscope(&sin6_d.sin6_addr, &sin6_d, NULL, NULL);
1234 			subj = (char *)&sin6;
1235 			if (SA6_ARE_ADDR_EQUAL(&sin6, &sin6_d))
1236 				break;
1237 
1238 			/*
1239 			 * XXX if we are to allow other cases, we should really
1240 			 * be careful about scope here.
1241 			 * basically, we should disallow queries toward IPv6
1242 			 * destination X with subject Y, if scope(X) > scope(Y).
1243 			 * if we allow scope(X) > scope(Y), it will result in
1244 			 * information leakage across scope boundary.
1245 			 */
1246 			goto bad;
1247 
1248 		case ICMP6_NI_SUBJ_FQDN:
1249 			/*
1250 			 * Validate Subject name with gethostname(3).
1251 			 *
1252 			 * The behavior may need some debate, since:
1253 			 * - we are not sure if the node has FQDN as
1254 			 *   hostname (returned by gethostname(3)).
1255 			 * - the code does wildcard match for truncated names.
1256 			 *   however, we are not sure if we want to perform
1257 			 *   wildcard match, if gethostname(3) side has
1258 			 *   truncated hostname.
1259 			 */
1260 			n = ni6_nametodns(hostname, hostnamelen, 0);
1261 			if (!n || n->m_next || n->m_len == 0)
1262 				goto bad;
1263 			IP6_EXTHDR_GET(subj, char *, m,
1264 			    off + sizeof(struct icmp6_nodeinfo), subjlen);
1265 			if (subj == NULL)
1266 				goto bad;
1267 			if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1268 					n->m_len)) {
1269 				goto bad;
1270 			}
1271 			m_freem(n);
1272 			n = NULL;
1273 			break;
1274 
1275 		case ICMP6_NI_SUBJ_IPV4:	/* XXX: to be implemented? */
1276 		default:
1277 			goto bad;
1278 		}
1279 		break;
1280 	}
1281 
1282 	/* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1283 	switch (qtype) {
1284 	case NI_QTYPE_FQDN:
1285 		if ((icmp6_nodeinfo & 1) == 0)
1286 			goto bad;
1287 		break;
1288 	case NI_QTYPE_NODEADDR:
1289 		if ((icmp6_nodeinfo & 2) == 0)
1290 			goto bad;
1291 		break;
1292 	}
1293 
1294 	/* guess reply length */
1295 	switch (qtype) {
1296 	case NI_QTYPE_NOOP:
1297 		break;		/* no reply data */
1298 	case NI_QTYPE_SUPTYPES:
1299 		replylen += sizeof(u_int32_t);
1300 		break;
1301 	case NI_QTYPE_FQDN:
1302 		/* XXX will append an mbuf */
1303 		replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1304 		break;
1305 	case NI_QTYPE_NODEADDR:
1306 		addrs = ni6_addrs(ni6, m, &ifp, subj);
1307 		if ((replylen += addrs * (sizeof(struct in6_addr) +
1308 					  sizeof(u_int32_t))) > MCLBYTES)
1309 			replylen = MCLBYTES; /* XXX: will truncate pkt later */
1310 		break;
1311 	default:
1312 		/*
1313 		 * XXX: We must return a reply with the ICMP6 code
1314 		 * `unknown Qtype' in this case. However we regard the case
1315 		 * as an FQDN query for backward compatibility.
1316 		 * Older versions set a random value to this field,
1317 		 * so it rarely varies in the defined qtypes.
1318 		 * But the mechanism is not reliable...
1319 		 * maybe we should obsolete older versions.
1320 		 */
1321 		qtype = NI_QTYPE_FQDN;
1322 		/* XXX will append an mbuf */
1323 		replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1324 		oldfqdn++;
1325 		break;
1326 	}
1327 
1328 	/* allocate an mbuf to reply. */
1329 	if (replylen > MCLBYTES) {
1330 		/*
1331 		 * XXX: should we try to allocate more? But MCLBYTES
1332 		 * is probably much larger than IPV6_MMTU...
1333 		 */
1334 		goto bad;
1335 	}
1336 	n = m_getb(replylen, MB_DONTWAIT, m->m_type, M_PKTHDR);
1337 	if (n == NULL) {
1338 		m_freem(m);
1339 		return (NULL);
1340 	}
1341 	M_MOVE_PKTHDR(n, m); /* just for recvif */
1342 	n->m_pkthdr.len = n->m_len = replylen;
1343 
1344 	/* copy mbuf header and IPv6 + Node Information base headers */
1345 	bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1346 	nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1347 	bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1348 
1349 	/* qtype dependent procedure */
1350 	switch (qtype) {
1351 	case NI_QTYPE_NOOP:
1352 		nni6->ni_code = ICMP6_NI_SUCCESS;
1353 		nni6->ni_flags = 0;
1354 		break;
1355 	case NI_QTYPE_SUPTYPES:
1356 	{
1357 		u_int32_t v;
1358 		nni6->ni_code = ICMP6_NI_SUCCESS;
1359 		nni6->ni_flags = htons(0x0000);	/* raw bitmap */
1360 		/* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1361 		v = (u_int32_t)htonl(0x0000000f);
1362 		bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1363 		break;
1364 	}
1365 	case NI_QTYPE_FQDN:
1366 		nni6->ni_code = ICMP6_NI_SUCCESS;
1367 		fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1368 						sizeof(struct ip6_hdr) +
1369 						sizeof(struct icmp6_nodeinfo));
1370 		nni6->ni_flags = 0; /* XXX: meaningless TTL */
1371 		fqdn->ni_fqdn_ttl = 0;	/* ditto. */
1372 		/*
1373 		 * XXX do we really have FQDN in variable "hostname"?
1374 		 */
1375 		n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn);
1376 		if (n->m_next == NULL)
1377 			goto bad;
1378 		/* XXX we assume that n->m_next is not a chain */
1379 		if (n->m_next->m_next != NULL)
1380 			goto bad;
1381 		n->m_pkthdr.len += n->m_next->m_len;
1382 		break;
1383 	case NI_QTYPE_NODEADDR:
1384 	{
1385 		int lenlim, copied;
1386 
1387 		nni6->ni_code = ICMP6_NI_SUCCESS;
1388 		n->m_pkthdr.len = n->m_len =
1389 		    sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1390 		lenlim = M_TRAILINGSPACE(n);
1391 		copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1392 		/* XXX: reset mbuf length */
1393 		n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1394 			sizeof(struct icmp6_nodeinfo) + copied;
1395 		break;
1396 	}
1397 	default:
1398 		break;		/* XXX impossible! */
1399 	}
1400 
1401 	nni6->ni_type = ICMP6_NI_REPLY;
1402 	m_freem(m);
1403 	return (n);
1404 
1405 bad:
1406 	m_freem(m);
1407 	if (n)
1408 		m_freem(n);
1409 	return (NULL);
1410 }
1411 #undef hostnamelen
1412 
1413 /*
1414  * make a mbuf with DNS-encoded string.  no compression support.
1415  *
1416  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1417  * treated as truncated name (two \0 at the end).  this is a wild guess.
1418  */
1419 static struct mbuf *
1420 ni6_nametodns(const char *name, int namelen,
1421 	      int old) /* return pascal string if non-zero */
1422 {
1423 	struct mbuf *m;
1424 	char *cp, *ep;
1425 	const char *p, *q;
1426 	int i, len, nterm;
1427 
1428 	if (old)
1429 		len = namelen + 1;
1430 	else
1431 		len = MCLBYTES;
1432 
1433 	/* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1434 	m = m_getb(len, MB_DONTWAIT, MT_DATA, 0);
1435 	if (!m)
1436 		goto fail;
1437 
1438 	if (old) {
1439 		m->m_len = len;
1440 		*mtod(m, char *) = namelen;
1441 		bcopy(name, mtod(m, char *) + 1, namelen);
1442 		return m;
1443 	} else {
1444 		m->m_len = 0;
1445 		cp = mtod(m, char *);
1446 		ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1447 
1448 		/* if not certain about my name, return empty buffer */
1449 		if (namelen == 0)
1450 			return m;
1451 
1452 		/*
1453 		 * guess if it looks like shortened hostname, or FQDN.
1454 		 * shortened hostname needs two trailing "\0".
1455 		 */
1456 		i = 0;
1457 		for (p = name; p < name + namelen; p++) {
1458 			if (*p && *p == '.')
1459 				i++;
1460 		}
1461 		if (i < 2)
1462 			nterm = 2;
1463 		else
1464 			nterm = 1;
1465 
1466 		p = name;
1467 		while (cp < ep && p < name + namelen) {
1468 			i = 0;
1469 			for (q = p; q < name + namelen && *q && *q != '.'; q++)
1470 				i++;
1471 			/* result does not fit into mbuf */
1472 			if (cp + i + 1 >= ep)
1473 				goto fail;
1474 			/*
1475 			 * DNS label length restriction, RFC1035 page 8.
1476 			 * "i == 0" case is included here to avoid returning
1477 			 * 0-length label on "foo..bar".
1478 			 */
1479 			if (i <= 0 || i >= 64)
1480 				goto fail;
1481 			*cp++ = i;
1482 			bcopy(p, cp, i);
1483 			cp += i;
1484 			p = q;
1485 			if (p < name + namelen && *p == '.')
1486 				p++;
1487 		}
1488 		/* termination */
1489 		if (cp + nterm >= ep)
1490 			goto fail;
1491 		while (nterm-- > 0)
1492 			*cp++ = '\0';
1493 		m->m_len = cp - mtod(m, char *);
1494 		return m;
1495 	}
1496 
1497 	panic("should not reach here");
1498 	/* NOTREACHED */
1499 
1500 fail:
1501 	if (m)
1502 		m_freem(m);
1503 	return NULL;
1504 }
1505 
1506 /*
1507  * check if two DNS-encoded string matches.  takes care of truncated
1508  * form (with \0\0 at the end).  no compression support.
1509  * XXX upper/lowercase match (see RFC2065)
1510  */
1511 static int
1512 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1513 {
1514 	const char *a0, *b0;
1515 	int l;
1516 
1517 	/* simplest case - need validation? */
1518 	if (alen == blen && bcmp(a, b, alen) == 0)
1519 		return 1;
1520 
1521 	a0 = a;
1522 	b0 = b;
1523 
1524 	/* termination is mandatory */
1525 	if (alen < 2 || blen < 2)
1526 		return 0;
1527 	if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1528 		return 0;
1529 	alen--;
1530 	blen--;
1531 
1532 	while (a - a0 < alen && b - b0 < blen) {
1533 		if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1534 			return 0;
1535 
1536 		if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1537 			return 0;
1538 		/* we don't support compression yet */
1539 		if (a[0] >= 64 || b[0] >= 64)
1540 			return 0;
1541 
1542 		/* truncated case */
1543 		if (a[0] == 0 && a - a0 == alen - 1)
1544 			return 1;
1545 		if (b[0] == 0 && b - b0 == blen - 1)
1546 			return 1;
1547 		if (a[0] == 0 || b[0] == 0)
1548 			return 0;
1549 
1550 		if (a[0] != b[0])
1551 			return 0;
1552 		l = a[0];
1553 		if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1554 			return 0;
1555 		if (bcmp(a + 1, b + 1, l) != 0)
1556 			return 0;
1557 
1558 		a += 1 + l;
1559 		b += 1 + l;
1560 	}
1561 
1562 	if (a - a0 == alen && b - b0 == blen)
1563 		return 1;
1564 	else
1565 		return 0;
1566 }
1567 
1568 /*
1569  * calculate the number of addresses to be returned in the node info reply.
1570  */
1571 static int
1572 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1573 	  char *subj)
1574 {
1575 	struct ifnet *ifp;
1576 	struct in6_ifaddr *ifa6;
1577 	struct sockaddr_in6 *subj_ip6 = NULL; /* XXX pedant */
1578 	int addrs = 0, addrsofif, iffound = 0;
1579 	int niflags = ni6->ni_flags;
1580 
1581 	if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1582 		switch (ni6->ni_code) {
1583 		case ICMP6_NI_SUBJ_IPV6:
1584 			if (subj == NULL) /* must be impossible... */
1585 				return (0);
1586 			subj_ip6 = (struct sockaddr_in6 *)subj;
1587 			break;
1588 		default:
1589 			/*
1590 			 * XXX: we only support IPv6 subject address for
1591 			 * this Qtype.
1592 			 */
1593 			return (0);
1594 		}
1595 	}
1596 
1597 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
1598 	{
1599 		struct ifaddr_container *ifac;
1600 
1601 		addrsofif = 0;
1602 		TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link)
1603 		{
1604 			struct ifaddr *ifa = ifac->ifa;
1605 
1606 			if (ifa->ifa_addr->sa_family != AF_INET6)
1607 				continue;
1608 			ifa6 = (struct in6_ifaddr *)ifa;
1609 
1610 			if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1611 			    IN6_ARE_ADDR_EQUAL(&subj_ip6->sin6_addr,
1612 					       &ifa6->ia_addr.sin6_addr))
1613 				iffound = 1;
1614 
1615 			/*
1616 			 * IPv4-mapped addresses can only be returned by a
1617 			 * Node Information proxy, since they represent
1618 			 * addresses of IPv4-only nodes, which perforce do
1619 			 * not implement this protocol.
1620 			 * [icmp-name-lookups-07, Section 5.4]
1621 			 * So we don't support NI_NODEADDR_FLAG_COMPAT in
1622 			 * this function at this moment.
1623 			 */
1624 
1625 			/* What do we have to do about ::1? */
1626 			switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1627 			case IPV6_ADDR_SCOPE_LINKLOCAL:
1628 				if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1629 					continue;
1630 				break;
1631 			case IPV6_ADDR_SCOPE_SITELOCAL:
1632 				if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1633 					continue;
1634 				break;
1635 			case IPV6_ADDR_SCOPE_GLOBAL:
1636 				if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1637 					continue;
1638 				break;
1639 			default:
1640 				continue;
1641 			}
1642 
1643 			/*
1644 			 * check if anycast is okay.
1645 			 * XXX: just experimental.  not in the spec.
1646 			 */
1647 			if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) &&
1648 			    !(niflags & NI_NODEADDR_FLAG_ANYCAST))
1649 				continue; /* we need only unicast addresses */
1650 			if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) &&
1651 			    (icmp6_nodeinfo & 4) == 0) {
1652 				continue;
1653 			}
1654 			addrsofif++; /* count the address */
1655 		}
1656 		if (iffound) {
1657 			*ifpp = ifp;
1658 			return (addrsofif);
1659 		}
1660 
1661 		addrs += addrsofif;
1662 	}
1663 
1664 	return (addrs);
1665 }
1666 
1667 static int
1668 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1669 		struct ifnet *ifp0, int resid)
1670 {
1671 	struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet);
1672 	struct in6_ifaddr *ifa6;
1673 	struct ifnet *ifp_dep = NULL;
1674 	int copied = 0, allow_deprecated = 0;
1675 	u_char *cp = (u_char *)(nni6 + 1);
1676 	int niflags = ni6->ni_flags;
1677 	u_int32_t ltime;
1678 
1679 	if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1680 		return (0);	/* needless to copy */
1681 
1682 again:
1683 
1684 	for (; ifp; ifp = TAILQ_NEXT(ifp, if_list))
1685 	{
1686 		struct ifaddr_container *ifac;
1687 
1688 		TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
1689 			struct ifaddr *ifa = ifac->ifa;
1690 
1691 			if (ifa->ifa_addr->sa_family != AF_INET6)
1692 				continue;
1693 			ifa6 = (struct in6_ifaddr *)ifa;
1694 
1695 			if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) &&
1696 			    allow_deprecated == 0) {
1697 				/*
1698 				 * prefererred address should be put before
1699 				 * deprecated addresses.
1700 				 */
1701 
1702 				/* record the interface for later search */
1703 				if (ifp_dep == NULL)
1704 					ifp_dep = ifp;
1705 
1706 				continue;
1707 			}
1708 			else if (!(ifa6->ia6_flags & IN6_IFF_DEPRECATED) &&
1709 				 allow_deprecated != 0)
1710 				continue; /* we now collect deprecated addrs */
1711 
1712 			/* What do we have to do about ::1? */
1713 			switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1714 			case IPV6_ADDR_SCOPE_LINKLOCAL:
1715 				if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1716 					continue;
1717 				break;
1718 			case IPV6_ADDR_SCOPE_SITELOCAL:
1719 				if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1720 					continue;
1721 				break;
1722 			case IPV6_ADDR_SCOPE_GLOBAL:
1723 				if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1724 					continue;
1725 				break;
1726 			default:
1727 				continue;
1728 			}
1729 
1730 			/*
1731 			 * check if anycast is okay.
1732 			 * XXX: just experimental. not in the spec.
1733 			 */
1734 			if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) &&
1735 			    !(niflags & NI_NODEADDR_FLAG_ANYCAST))
1736 				continue;
1737 			if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) &&
1738 			    (icmp6_nodeinfo & 4) == 0) {
1739 				continue;
1740 			}
1741 
1742 			/* now we can copy the address */
1743 			if (resid < sizeof(struct in6_addr) +
1744 			    sizeof(u_int32_t)) {
1745 				/*
1746 				 * We give up much more copy.
1747 				 * Set the truncate flag and return.
1748 				 */
1749 				nni6->ni_flags |=
1750 					NI_NODEADDR_FLAG_TRUNCATE;
1751 				return (copied);
1752 			}
1753 
1754 			/*
1755 			 * Set the TTL of the address.
1756 			 * The TTL value should be one of the following
1757 			 * according to the specification:
1758 			 *
1759 			 * 1. The remaining lifetime of a DHCP lease on the
1760 			 *    address, or
1761 			 * 2. The remaining Valid Lifetime of a prefix from
1762 			 *    which the address was derived through Stateless
1763 			 *    Autoconfiguration.
1764 			 *
1765 			 * Note that we currently do not support stateful
1766 			 * address configuration by DHCPv6, so the former
1767 			 * case can't happen.
1768 			 */
1769 			if (ifa6->ia6_lifetime.ia6t_expire == 0)
1770 				ltime = ND6_INFINITE_LIFETIME;
1771 			else {
1772 				if (ifa6->ia6_lifetime.ia6t_expire >
1773 				    time_second)
1774 					ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second);
1775 				else
1776 					ltime = 0;
1777 			}
1778 
1779 			bcopy(&ltime, cp, sizeof(u_int32_t));
1780 			cp += sizeof(u_int32_t);
1781 
1782 			/* copy the address itself */
1783 			bcopy(&ifa6->ia_addr.sin6_addr, cp,
1784 			      sizeof(struct in6_addr));
1785 			/* XXX: KAME link-local hack; remove ifindex */
1786 			if (IN6_IS_ADDR_LINKLOCAL(&ifa6->ia_addr.sin6_addr))
1787 				((struct in6_addr *)cp)->s6_addr16[1] = 0;
1788 			cp += sizeof(struct in6_addr);
1789 
1790 			resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1791 			copied += (sizeof(struct in6_addr) +
1792 				   sizeof(u_int32_t));
1793 		}
1794 		if (ifp0)	/* we need search only on the specified IF */
1795 			break;
1796 	}
1797 
1798 	if (allow_deprecated == 0 && ifp_dep != NULL) {
1799 		ifp = ifp_dep;
1800 		allow_deprecated = 1;
1801 
1802 		goto again;
1803 	}
1804 
1805 	return (copied);
1806 }
1807 
1808 /*
1809  * XXX almost dup'ed code with rip6_input.
1810  */
1811 static int
1812 icmp6_rip6_input(struct	mbuf **mp, int	off)
1813 {
1814 	struct mbuf *m = *mp;
1815 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1816 	struct in6pcb *in6p;
1817 	struct in6pcb *last = NULL;
1818 	struct sockaddr_in6 rip6src;
1819 	struct icmp6_hdr *icmp6;
1820 	struct mbuf *opts = NULL;
1821 
1822 #ifndef PULLDOWN_TEST
1823 	/* this is assumed to be safe. */
1824 	icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1825 #else
1826 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1827 	if (icmp6 == NULL) {
1828 		/* m is already reclaimed */
1829 		return IPPROTO_DONE;
1830 	}
1831 #endif
1832 
1833 	bzero(&rip6src, sizeof(rip6src));
1834 	rip6src.sin6_len = sizeof(struct sockaddr_in6);
1835 	rip6src.sin6_family = AF_INET6;
1836 	/* KAME hack: recover scopeid */
1837 	in6_recoverscope(&rip6src, &ip6->ip6_src, m->m_pkthdr.rcvif);
1838 
1839 	LIST_FOREACH(in6p, &ripcbinfo.pcblisthead, inp_list)
1840 	{
1841 		if (in6p->inp_flags & INP_PLACEMARKER)
1842 			continue;
1843 		if ((in6p->inp_vflag & INP_IPV6) == 0)
1844 			continue;
1845 #ifdef HAVE_NRL_INPCB
1846 		if (!(in6p->in6p_flags & INP_IPV6))
1847 			continue;
1848 #endif
1849 		if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6)
1850 			continue;
1851 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1852 		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1853 			continue;
1854 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1855 		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1856 			continue;
1857 		if (in6p->in6p_icmp6filt
1858 		    && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1859 				 in6p->in6p_icmp6filt))
1860 			continue;
1861 		if (last) {
1862 			struct socket *so;
1863 			struct mbuf *n;
1864 
1865 			if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
1866 				if (last->in6p_flags & IN6P_CONTROLOPTS)
1867 					ip6_savecontrol(last, &opts, ip6, n);
1868 				/* strip intermediate headers */
1869 				m_adj(n, off);
1870 				so = last->in6p_socket;
1871 				lwkt_gettoken(&so->so_rcv.ssb_token);
1872 				if (ssb_appendaddr(&so->so_rcv,
1873 						 (struct sockaddr *)&rip6src,
1874 						 n, opts) == 0) {
1875 					/* should notify about lost packet */
1876 					m_freem(n);
1877 					if (opts)
1878 						m_freem(opts);
1879 				} else {
1880 					sorwakeup(so);
1881 				}
1882 				lwkt_reltoken(&so->so_rcv.ssb_token);
1883 				opts = NULL;
1884 			}
1885 		}
1886 		last = in6p;
1887 	}
1888 	if (last) {
1889 		struct socket *so;
1890 
1891 		if (last->in6p_flags & IN6P_CONTROLOPTS)
1892 			ip6_savecontrol(last, &opts, ip6, m);
1893 		/* strip intermediate headers */
1894 		m_adj(m, off);
1895 		so = last->in6p_socket;
1896 		lwkt_gettoken(&so->so_rcv.ssb_token);
1897 		if (ssb_appendaddr(&so->so_rcv, (struct sockaddr *)&rip6src,
1898 				   m, opts) == 0) {
1899 			m_freem(m);
1900 			if (opts)
1901 				m_freem(opts);
1902 		} else {
1903 			sorwakeup(so);
1904 		}
1905 		lwkt_reltoken(&so->so_rcv.ssb_token);
1906 	} else {
1907 		m_freem(m);
1908 		ip6stat.ip6s_delivered--;
1909 	}
1910 	return IPPROTO_DONE;
1911 }
1912 
1913 /*
1914  * Reflect the ip6 packet back to the source.
1915  * OFF points to the icmp6 header, counted from the top of the mbuf.
1916  */
1917 void
1918 icmp6_reflect(struct mbuf *m, size_t off)
1919 {
1920 	struct ip6_hdr *ip6;
1921 	struct icmp6_hdr *icmp6;
1922 	struct in6_ifaddr *ia;
1923 	struct in6_addr t, *src = 0;
1924 	int plen;
1925 	int type, code;
1926 	struct ifnet *outif = NULL;
1927 	struct sockaddr_in6 sa6_src, sa6_dst;
1928 #ifdef COMPAT_RFC1885
1929 	int mtu = IPV6_MMTU;
1930 	struct sockaddr_in6 *sin6 = &icmp6_reflect_rt.ro_dst;
1931 #endif
1932 
1933 	/* too short to reflect */
1934 	if (off < sizeof(struct ip6_hdr)) {
1935 		nd6log((LOG_DEBUG,
1936 		    "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
1937 		    (u_long)off, (u_long)sizeof(struct ip6_hdr),
1938 		    __FILE__, __LINE__));
1939 		goto bad;
1940 	}
1941 
1942 	/*
1943 	 * If there are extra headers between IPv6 and ICMPv6, strip
1944 	 * off that header first.
1945 	 */
1946 #ifdef DIAGNOSTIC
1947 	if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
1948 		panic("assumption failed in icmp6_reflect");
1949 #endif
1950 	if (off > sizeof(struct ip6_hdr)) {
1951 		size_t l;
1952 		struct ip6_hdr nip6;
1953 
1954 		l = off - sizeof(struct ip6_hdr);
1955 		m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
1956 		m_adj(m, l);
1957 		l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
1958 		if (m->m_len < l) {
1959 			if ((m = m_pullup(m, l)) == NULL)
1960 				return;
1961 		}
1962 		bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
1963 	} else /* off == sizeof(struct ip6_hdr) */ {
1964 		size_t l;
1965 		l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
1966 		if (m->m_len < l) {
1967 			if ((m = m_pullup(m, l)) == NULL)
1968 				return;
1969 		}
1970 	}
1971 	plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
1972 	ip6 = mtod(m, struct ip6_hdr *);
1973 	ip6->ip6_nxt = IPPROTO_ICMPV6;
1974 	icmp6 = (struct icmp6_hdr *)(ip6 + 1);
1975 	type = icmp6->icmp6_type; /* keep type for statistics */
1976 	code = icmp6->icmp6_code; /* ditto. */
1977 
1978 	t = ip6->ip6_dst;
1979 	/*
1980 	 * ip6_input() drops a packet if its src is multicast.
1981 	 * So, the src is never multicast.
1982 	 */
1983 	ip6->ip6_dst = ip6->ip6_src;
1984 
1985 	/*
1986 	 * XXX: make sure to embed scope zone information, using
1987 	 * already embedded IDs or the received interface (if any).
1988 	 * Note that rcvif may be NULL.
1989 	 * TODO: scoped routing case (XXX).
1990 	 */
1991 	bzero(&sa6_src, sizeof(sa6_src));
1992 	sa6_src.sin6_family = AF_INET6;
1993 	sa6_src.sin6_len = sizeof(sa6_src);
1994 	sa6_src.sin6_addr = ip6->ip6_dst;
1995 	in6_recoverscope(&sa6_src, &ip6->ip6_dst, m->m_pkthdr.rcvif);
1996 	in6_embedscope(&ip6->ip6_dst, &sa6_src, NULL, NULL);
1997 	bzero(&sa6_dst, sizeof(sa6_dst));
1998 	sa6_dst.sin6_family = AF_INET6;
1999 	sa6_dst.sin6_len = sizeof(sa6_dst);
2000 	sa6_dst.sin6_addr = t;
2001 	in6_recoverscope(&sa6_dst, &t, m->m_pkthdr.rcvif);
2002 	in6_embedscope(&t, &sa6_dst, NULL, NULL);
2003 
2004 #ifdef COMPAT_RFC1885
2005 	/*
2006 	 * xxx guess MTU
2007 	 * RFC 1885 requires that echo reply should be truncated if it
2008 	 * does not fit in with (return) path MTU, but the description was
2009 	 * removed in the new spec.
2010 	 */
2011 	if (icmp6_reflect_rt.ro_rt == 0 ||
2012 	    ! (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &ip6->ip6_dst))) {
2013 		if (icmp6_reflect_rt.ro_rt) {
2014 			RTFREE(icmp6_reflect_rt.ro_rt);
2015 			icmp6_reflect_rt.ro_rt = 0;
2016 		}
2017 		bzero(sin6, sizeof(*sin6));
2018 		sin6->sin6_family = PF_INET6;
2019 		sin6->sin6_len = sizeof(struct sockaddr_in6);
2020 		sin6->sin6_addr = ip6->ip6_dst;
2021 
2022 		rtalloc_ign((struct route *)&icmp6_reflect_rt.ro_rt,
2023 			    RTF_PRCLONING);
2024 	}
2025 
2026 	if (icmp6_reflect_rt.ro_rt == 0)
2027 		goto bad;
2028 
2029 	if ((icmp6_reflect_rt.ro_rt->rt_flags & RTF_HOST)
2030 	    && mtu < icmp6_reflect_rt.ro_rt->rt_ifp->if_mtu)
2031 		mtu = icmp6_reflect_rt.ro_rt->rt_rmx.rmx_mtu;
2032 
2033 	if (mtu < m->m_pkthdr.len) {
2034 		plen -= (m->m_pkthdr.len - mtu);
2035 		m_adj(m, mtu - m->m_pkthdr.len);
2036 	}
2037 #endif
2038 	/*
2039 	 * If the incoming packet was addressed directly to us(i.e. unicast),
2040 	 * use dst as the src for the reply.
2041 	 * The IN6_IFF_NOTREADY case would be VERY rare, but is possible
2042 	 * (for example) when we encounter an error while forwarding procedure
2043 	 * destined to a duplicated address of ours.
2044 	 */
2045 	for (ia = in6_ifaddr; ia; ia = ia->ia_next)
2046 		if (IN6_ARE_ADDR_EQUAL(&t, &ia->ia_addr.sin6_addr) &&
2047 		    (ia->ia6_flags & (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) {
2048 			src = &t;
2049 			break;
2050 		}
2051 	if (ia == NULL && IN6_IS_ADDR_LINKLOCAL(&t) && (m->m_flags & M_LOOP)) {
2052 		/*
2053 		 * This is the case if the dst is our link-local address
2054 		 * and the sender is also ourselves.
2055 		 */
2056 		src = &t;
2057 	}
2058 
2059 	if (src == 0) {
2060 		int e;
2061 		struct route_in6 ro;
2062 
2063 		/*
2064 		 * This case matches to multicasts, our anycast, or unicasts
2065 		 * that we do not own.  Select a source address based on the
2066 		 * source address of the erroneous packet.
2067 		 */
2068 		bzero(&ro, sizeof(ro));
2069 		src = in6_selectsrc(&sa6_src, NULL, NULL, &ro, NULL, &e, NULL);
2070 		if (ro.ro_rt)
2071 			RTFREE(ro.ro_rt); /* XXX: we could use this */
2072 		if (src == NULL) {
2073 			nd6log((LOG_DEBUG,
2074 			    "icmp6_reflect: source can't be determined: "
2075 			    "dst=%s, error=%d\n",
2076 			    ip6_sprintf(&sa6_src.sin6_addr), e));
2077 			goto bad;
2078 		}
2079 	}
2080 
2081 	ip6->ip6_src = *src;
2082 
2083 	ip6->ip6_flow = 0;
2084 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2085 	ip6->ip6_vfc |= IPV6_VERSION;
2086 	ip6->ip6_nxt = IPPROTO_ICMPV6;
2087 	if (m->m_pkthdr.rcvif) {
2088 		/* XXX: This may not be the outgoing interface */
2089 		ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2090 	} else
2091 		ip6->ip6_hlim = ip6_defhlim;
2092 
2093 	icmp6->icmp6_cksum = 0;
2094 	icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2095 					sizeof(struct ip6_hdr), plen);
2096 
2097 	/*
2098 	 * XXX option handling
2099 	 */
2100 
2101 	m->m_flags &= ~(M_BCAST|M_MCAST);
2102 
2103 #ifdef COMPAT_RFC1885
2104 	ip6_output(m, NULL, &icmp6_reflect_rt, 0, NULL, &outif, NULL);
2105 #else
2106 	ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2107 #endif
2108 	if (outif)
2109 		icmp6_ifoutstat_inc(outif, type, code);
2110 
2111 	return;
2112 
2113 bad:
2114 	m_freem(m);
2115 	return;
2116 }
2117 
2118 void
2119 icmp6_fasttimo(void)
2120 {
2121 
2122 	mld6_fasttimeo();
2123 }
2124 
2125 static const char *
2126 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2127 		    struct in6_addr *tgt6)
2128 {
2129 	static char buf[1024];
2130 	ksnprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2131 		ip6_sprintf(src6), ip6_sprintf(dst6), ip6_sprintf(tgt6));
2132 	return buf;
2133 }
2134 
2135 void
2136 icmp6_redirect_input(struct mbuf *m, int off)
2137 {
2138 	struct ifnet *ifp = m->m_pkthdr.rcvif;
2139 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2140 	struct nd_redirect *nd_rd;
2141 	int icmp6len = ntohs(ip6->ip6_plen);
2142 	char *lladdr = NULL;
2143 	int lladdrlen = 0;
2144 	u_char *redirhdr = NULL;
2145 	int redirhdrlen = 0;
2146 	struct rtentry *rt = NULL;
2147 	int is_router;
2148 	int is_onlink;
2149 	struct in6_addr src6 = ip6->ip6_src;
2150 	struct in6_addr redtgt6;
2151 	struct in6_addr reddst6;
2152 	union nd_opts ndopts;
2153 
2154 	if (!m || !ifp)
2155 		return;
2156 
2157 	/* XXX if we are router, we don't update route by icmp6 redirect */
2158 	if (ip6_forwarding)
2159 		goto freeit;
2160 	if (!icmp6_rediraccept)
2161 		goto freeit;
2162 
2163 #ifndef PULLDOWN_TEST
2164 	IP6_EXTHDR_CHECK(m, off, icmp6len,);
2165 	nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2166 #else
2167 	IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2168 	if (nd_rd == NULL) {
2169 		icmp6stat.icp6s_tooshort++;
2170 		return;
2171 	}
2172 #endif
2173 	redtgt6 = nd_rd->nd_rd_target;
2174 	reddst6 = nd_rd->nd_rd_dst;
2175 
2176 	if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2177 		redtgt6.s6_addr16[1] = htons(ifp->if_index);
2178 	if (IN6_IS_ADDR_LINKLOCAL(&reddst6))
2179 		reddst6.s6_addr16[1] = htons(ifp->if_index);
2180 
2181 	/* validation */
2182 	if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2183 		nd6log((LOG_ERR,
2184 			"ICMP6 redirect sent from %s rejected; "
2185 			"must be from linklocal\n", ip6_sprintf(&src6)));
2186 		goto bad;
2187 	}
2188 	if (ip6->ip6_hlim != 255) {
2189 		nd6log((LOG_ERR,
2190 			"ICMP6 redirect sent from %s rejected; "
2191 			"hlim=%d (must be 255)\n",
2192 			ip6_sprintf(&src6), ip6->ip6_hlim));
2193 		goto bad;
2194 	}
2195     {
2196 	/* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2197 	struct sockaddr_in6 sin6;
2198 	struct in6_addr *gw6;
2199 
2200 	bzero(&sin6, sizeof(sin6));
2201 	sin6.sin6_family = AF_INET6;
2202 	sin6.sin6_len = sizeof(struct sockaddr_in6);
2203 	bcopy(&reddst6, &sin6.sin6_addr, sizeof reddst6);
2204 	rt = rtpurelookup((struct sockaddr *)&sin6);
2205 	if (rt != NULL) {
2206 		if (rt->rt_gateway == NULL ||
2207 		    rt->rt_gateway->sa_family != AF_INET6) {
2208 			nd6log((LOG_ERR,
2209 			    "ICMP6 redirect rejected; no route "
2210 			    "with inet6 gateway found for redirect dst: %s\n",
2211 			    icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2212 			--rt->rt_refcnt;
2213 			goto bad;
2214 		}
2215 
2216 		gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2217 		if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2218 			nd6log((LOG_ERR,
2219 				"ICMP6 redirect rejected; "
2220 				"not equal to gw-for-src=%s (must be same): "
2221 				"%s\n",
2222 				ip6_sprintf(gw6),
2223 				icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2224 			--rt->rt_refcnt;
2225 			goto bad;
2226 		}
2227 	} else {
2228 		nd6log((LOG_ERR,
2229 			"ICMP6 redirect rejected; "
2230 			"no route found for redirect dst: %s\n",
2231 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2232 		goto bad;
2233 	}
2234 	--rt->rt_refcnt;
2235 	rt = NULL;
2236     }
2237 	if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2238 		nd6log((LOG_ERR,
2239 			"ICMP6 redirect rejected; "
2240 			"redirect dst must be unicast: %s\n",
2241 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2242 		goto bad;
2243 	}
2244 
2245 	is_router = is_onlink = 0;
2246 	if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2247 		is_router = 1;	/* router case */
2248 	if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2249 		is_onlink = 1;	/* on-link destination case */
2250 	if (!is_router && !is_onlink) {
2251 		nd6log((LOG_ERR,
2252 			"ICMP6 redirect rejected; "
2253 			"neither router case nor onlink case: %s\n",
2254 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2255 		goto bad;
2256 	}
2257 	/* validation passed */
2258 
2259 	icmp6len -= sizeof(*nd_rd);
2260 	nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2261 	if (nd6_options(&ndopts) < 0) {
2262 		nd6log((LOG_INFO, "icmp6_redirect_input: "
2263 			"invalid ND option, rejected: %s\n",
2264 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2265 		/* nd6_options have incremented stats */
2266 		goto freeit;
2267 	}
2268 
2269 	if (ndopts.nd_opts_tgt_lladdr) {
2270 		lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2271 		lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2272 	}
2273 
2274 	if (ndopts.nd_opts_rh) {
2275 		redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
2276 		redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
2277 	}
2278 
2279 	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2280 		nd6log((LOG_INFO,
2281 			"icmp6_redirect_input: lladdrlen mismatch for %s "
2282 			"(if %d, icmp6 packet %d): %s\n",
2283 			ip6_sprintf(&redtgt6), ifp->if_addrlen, lladdrlen - 2,
2284 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2285 		goto bad;
2286 	}
2287 
2288 	/* RFC 2461 8.3 */
2289 	nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2290 			 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2291 
2292 	if (!is_onlink) {	/* better router case.  perform rtredirect. */
2293 		/* perform rtredirect */
2294 		struct sockaddr_in6 sdst;
2295 		struct sockaddr_in6 sgw;
2296 		struct sockaddr_in6 ssrc;
2297 
2298 		bzero(&sdst, sizeof(sdst));
2299 		bzero(&sgw, sizeof(sgw));
2300 		bzero(&ssrc, sizeof(ssrc));
2301 		sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2302 		sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2303 			sizeof(struct sockaddr_in6);
2304 		bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2305 		bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2306 		bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2307 		rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2308 			   NULL, RTF_GATEWAY | RTF_HOST,
2309 			   (struct sockaddr *)&ssrc);
2310 	}
2311 	/* finally update cached route in each socket via kpfctlinput */
2312     {
2313 	struct sockaddr_in6 sdst;
2314 
2315 	bzero(&sdst, sizeof(sdst));
2316 	sdst.sin6_family = AF_INET6;
2317 	sdst.sin6_len = sizeof(struct sockaddr_in6);
2318 	bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2319 	kpfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2320 #ifdef IPSEC
2321 	key_sa_routechange((struct sockaddr *)&sdst);
2322 #endif
2323     }
2324 
2325 freeit:
2326 	m_freem(m);
2327 	return;
2328 
2329 bad:
2330 	icmp6stat.icp6s_badredirect++;
2331 	m_freem(m);
2332 }
2333 
2334 void
2335 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2336 {
2337 	struct ifnet *ifp;	/* my outgoing interface */
2338 	struct in6_addr *ifp_ll6;
2339 	struct in6_addr *router_ll6;
2340 	struct ip6_hdr *sip6;	/* m0 as struct ip6_hdr */
2341 	struct mbuf *m = NULL;	/* newly allocated one */
2342 	struct ip6_hdr *ip6;	/* m as struct ip6_hdr */
2343 	struct nd_redirect *nd_rd;
2344 	size_t maxlen;
2345 	u_char *p;
2346 	struct ifnet *outif = NULL;
2347 	struct sockaddr_in6 src_sa;
2348 
2349 	icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
2350 
2351 	/* if we are not router, we don't send icmp6 redirect */
2352 	if (!ip6_forwarding || ip6_accept_rtadv)
2353 		goto fail;
2354 
2355 	/* sanity check */
2356 	if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2357 		goto fail;
2358 
2359 	/*
2360 	 * Address check:
2361 	 *  the source address must identify a neighbor, and
2362 	 *  the destination address must not be a multicast address
2363 	 *  [RFC 2461, sec 8.2]
2364 	 */
2365 	sip6 = mtod(m0, struct ip6_hdr *);
2366 	bzero(&src_sa, sizeof(src_sa));
2367 	src_sa.sin6_family = AF_INET6;
2368 	src_sa.sin6_len = sizeof(src_sa);
2369 	src_sa.sin6_addr = sip6->ip6_src;
2370 	/* we don't currently use sin6_scope_id, but eventually use it */
2371 	src_sa.sin6_scope_id = in6_addr2scopeid(ifp, &sip6->ip6_src);
2372 	if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2373 		goto fail;
2374 	if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2375 		goto fail;	/* what should we do here? */
2376 
2377 	/* rate limit */
2378 	if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2379 		goto fail;
2380 
2381 	/*
2382 	 * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2383 	 * we almost always ask for an mbuf cluster for simplicity.
2384 	 * (MHLEN < IPV6_MMTU is almost always true)
2385 	 */
2386 #if IPV6_MMTU >= MCLBYTES
2387 # error assumption failed about IPV6_MMTU and MCLBYTES
2388 #endif
2389 	m = m_getb(IPV6_MMTU, MB_DONTWAIT, MT_HEADER, M_PKTHDR);
2390 	if (!m)
2391 		goto fail;
2392 	m->m_len = 0;
2393 	maxlen = M_TRAILINGSPACE(m);
2394 	maxlen = min(IPV6_MMTU, maxlen);
2395 	/* just for safety */
2396 	if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2397 	    ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2398 		goto fail;
2399 	}
2400 
2401 	{
2402 		/* get ip6 linklocal address for ifp(my outgoing interface). */
2403 		struct in6_ifaddr *ia;
2404 		if ((ia = in6ifa_ifpforlinklocal(ifp,
2405 						 IN6_IFF_NOTREADY|
2406 						 IN6_IFF_ANYCAST)) == NULL)
2407 			goto fail;
2408 		ifp_ll6 = &ia->ia_addr.sin6_addr;
2409 	}
2410 
2411 	/* get ip6 linklocal address for the router. */
2412 	if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2413 		struct sockaddr_in6 *sin6;
2414 		sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2415 		router_ll6 = &sin6->sin6_addr;
2416 		if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2417 			router_ll6 = NULL;
2418 	} else
2419 		router_ll6 = NULL;
2420 
2421 	/* ip6 */
2422 	ip6 = mtod(m, struct ip6_hdr *);
2423 	ip6->ip6_flow = 0;
2424 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2425 	ip6->ip6_vfc |= IPV6_VERSION;
2426 	/* ip6->ip6_plen will be set later */
2427 	ip6->ip6_nxt = IPPROTO_ICMPV6;
2428 	ip6->ip6_hlim = 255;
2429 	/* ip6->ip6_src must be linklocal addr for my outgoing if. */
2430 	bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2431 	bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2432 
2433 	/* ND Redirect */
2434 	nd_rd = (struct nd_redirect *)(ip6 + 1);
2435 	nd_rd->nd_rd_type = ND_REDIRECT;
2436 	nd_rd->nd_rd_code = 0;
2437 	nd_rd->nd_rd_reserved = 0;
2438 	if (rt->rt_flags & RTF_GATEWAY) {
2439 		/*
2440 		 * nd_rd->nd_rd_target must be a link-local address in
2441 		 * better router cases.
2442 		 */
2443 		if (!router_ll6)
2444 			goto fail;
2445 		bcopy(router_ll6, &nd_rd->nd_rd_target,
2446 		      sizeof(nd_rd->nd_rd_target));
2447 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2448 		      sizeof(nd_rd->nd_rd_dst));
2449 	} else {
2450 		/* make sure redtgt == reddst */
2451 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2452 		      sizeof(nd_rd->nd_rd_target));
2453 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2454 		      sizeof(nd_rd->nd_rd_dst));
2455 	}
2456 
2457 	p = (u_char *)(nd_rd + 1);
2458 
2459 	if (!router_ll6)
2460 		goto nolladdropt;
2461 
2462     {
2463 	/* target lladdr option */
2464 	struct rtentry *rt_router = NULL;
2465 	int len;
2466 	struct sockaddr_dl *sdl;
2467 	struct nd_opt_hdr *nd_opt;
2468 	char *lladdr;
2469 
2470 	rt_router = nd6_lookup(router_ll6, 0, ifp);
2471 	if (!rt_router)
2472 		goto nolladdropt;
2473 	len = sizeof(*nd_opt) + ifp->if_addrlen;
2474 	len = (len + 7) & ~7;	/* round by 8 */
2475 	/* safety check */
2476 	if (len + (p - (u_char *)ip6) > maxlen)
2477 		goto nolladdropt;
2478 	if (!(rt_router->rt_flags & RTF_GATEWAY) &&
2479 	    (rt_router->rt_flags & RTF_LLINFO) &&
2480 	    (rt_router->rt_gateway->sa_family == AF_LINK) &&
2481 	    (sdl = (struct sockaddr_dl *)rt_router->rt_gateway) &&
2482 	    sdl->sdl_alen) {
2483 		nd_opt = (struct nd_opt_hdr *)p;
2484 		nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2485 		nd_opt->nd_opt_len = len >> 3;
2486 		lladdr = (char *)(nd_opt + 1);
2487 		bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen);
2488 		p += len;
2489 	}
2490     }
2491 nolladdropt:;
2492 
2493 	m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2494 
2495 	/* just to be safe */
2496 #ifdef M_DECRYPTED	/*not openbsd*/
2497 	if (m0->m_flags & M_DECRYPTED)
2498 		goto noredhdropt;
2499 #endif
2500 	if (p - (u_char *)ip6 > maxlen)
2501 		goto noredhdropt;
2502 
2503     {
2504 	/* redirected header option */
2505 	int len;
2506 	struct nd_opt_rd_hdr *nd_opt_rh;
2507 
2508 	/*
2509 	 * compute the maximum size for icmp6 redirect header option.
2510 	 * XXX room for auth header?
2511 	 */
2512 	len = maxlen - (p - (u_char *)ip6);
2513 	len &= ~7;
2514 
2515 	/* This is just for simplicity. */
2516 	if (m0->m_pkthdr.len != m0->m_len) {
2517 		if (m0->m_next) {
2518 			m_freem(m0->m_next);
2519 			m0->m_next = NULL;
2520 		}
2521 		m0->m_pkthdr.len = m0->m_len;
2522 	}
2523 
2524 	/*
2525 	 * Redirected header option spec (RFC2461 4.6.3) talks nothing
2526 	 * about padding/truncate rule for the original IP packet.
2527 	 * From the discussion on IPv6imp in Feb 1999, the consensus was:
2528 	 * - "attach as much as possible" is the goal
2529 	 * - pad if not aligned (original size can be guessed by original
2530 	 *   ip6 header)
2531 	 * Following code adds the padding if it is simple enough,
2532 	 * and truncates if not.
2533 	 */
2534 	if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2535 		panic("assumption failed in %s:%d", __FILE__, __LINE__);
2536 
2537 	if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2538 		/* not enough room, truncate */
2539 		m0->m_pkthdr.len = m0->m_len = len - sizeof(*nd_opt_rh);
2540 	} else {
2541 		/* enough room, pad or truncate */
2542 		size_t extra;
2543 
2544 		extra = m0->m_pkthdr.len % 8;
2545 		if (extra) {
2546 			/* pad if easy enough, truncate if not */
2547 			if (8 - extra <= M_TRAILINGSPACE(m0)) {
2548 				/* pad */
2549 				m0->m_len += (8 - extra);
2550 				m0->m_pkthdr.len += (8 - extra);
2551 			} else {
2552 				/* truncate */
2553 				m0->m_pkthdr.len -= extra;
2554 				m0->m_len -= extra;
2555 			}
2556 		}
2557 		len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2558 		m0->m_pkthdr.len = m0->m_len = len - sizeof(*nd_opt_rh);
2559 	}
2560 
2561 	nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2562 	bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2563 	nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2564 	nd_opt_rh->nd_opt_rh_len = len >> 3;
2565 	p += sizeof(*nd_opt_rh);
2566 	m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2567 
2568 	/* connect m0 to m */
2569 	m->m_next = m0;
2570 	m->m_pkthdr.len = m->m_len + m0->m_len;
2571     }
2572 noredhdropt:;
2573 
2574 	if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_src))
2575 		sip6->ip6_src.s6_addr16[1] = 0;
2576 	if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_dst))
2577 		sip6->ip6_dst.s6_addr16[1] = 0;
2578 #if 0
2579 	if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
2580 		ip6->ip6_src.s6_addr16[1] = 0;
2581 	if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
2582 		ip6->ip6_dst.s6_addr16[1] = 0;
2583 #endif
2584 	if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_target))
2585 		nd_rd->nd_rd_target.s6_addr16[1] = 0;
2586 	if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_dst))
2587 		nd_rd->nd_rd_dst.s6_addr16[1] = 0;
2588 
2589 	ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2590 
2591 	nd_rd->nd_rd_cksum = 0;
2592 	nd_rd->nd_rd_cksum
2593 		= in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), ntohs(ip6->ip6_plen));
2594 
2595 	/* send the packet to outside... */
2596 	ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2597 	if (outif) {
2598 		icmp6_ifstat_inc(outif, ifs6_out_msg);
2599 		icmp6_ifstat_inc(outif, ifs6_out_redirect);
2600 	}
2601 	icmp6stat.icp6s_outhist[ND_REDIRECT]++;
2602 
2603 	return;
2604 
2605 fail:
2606 	if (m)
2607 		m_freem(m);
2608 	if (m0)
2609 		m_freem(m0);
2610 }
2611 
2612 #ifdef HAVE_NRL_INPCB
2613 #define in6pcb		inpcb
2614 #define in6p_icmp6filt	inp_icmp6filt
2615 #endif
2616 /*
2617  * ICMPv6 socket option processing.
2618  */
2619 void
2620 icmp6_ctloutput(netmsg_t msg)
2621 {
2622 	struct socket *so = msg->ctloutput.base.nm_so;
2623 	struct sockopt *sopt = msg->ctloutput.nm_sopt;
2624 	int error = 0;
2625 	int optlen;
2626 	struct inpcb *inp = so->so_pcb;
2627 	int level, op, optname;
2628 
2629 	if (sopt) {
2630 		level = sopt->sopt_level;
2631 		op = sopt->sopt_dir;
2632 		optname = sopt->sopt_name;
2633 		optlen = sopt->sopt_valsize;
2634 	} else
2635 		level = op = optname = optlen = 0;
2636 
2637 	if (level != IPPROTO_ICMPV6) {
2638 		error = EINVAL;
2639 		goto out;
2640 	}
2641 
2642 	switch (op) {
2643 	case PRCO_SETOPT:
2644 		switch (optname) {
2645 		case ICMP6_FILTER:
2646 		    {
2647 			struct icmp6_filter *p;
2648 
2649 			if (optlen != sizeof(*p)) {
2650 				error = EMSGSIZE;
2651 				break;
2652 			}
2653 			if (inp->in6p_icmp6filt == NULL) {
2654 				error = EINVAL;
2655 				break;
2656 			}
2657 			error = soopt_to_kbuf(sopt, inp->in6p_icmp6filt, optlen,
2658 				optlen);
2659 			break;
2660 		    }
2661 
2662 		default:
2663 			error = ENOPROTOOPT;
2664 			break;
2665 		}
2666 		break;
2667 
2668 	case PRCO_GETOPT:
2669 		switch (optname) {
2670 		case ICMP6_FILTER:
2671 		    {
2672 			if (inp->in6p_icmp6filt == NULL) {
2673 				error = EINVAL;
2674 				break;
2675 			}
2676 			soopt_from_kbuf(sopt, inp->in6p_icmp6filt,
2677 				sizeof(struct icmp6_filter));
2678 			break;
2679 		    }
2680 
2681 		default:
2682 			error = ENOPROTOOPT;
2683 			break;
2684 		}
2685 		break;
2686 	}
2687 out:
2688 	lwkt_replymsg(&msg->ctloutput.base.lmsg, error);
2689 }
2690 #ifdef HAVE_NRL_INPCB
2691 #undef in6pcb
2692 #undef in6p_icmp6filt
2693 #endif
2694 
2695 #ifndef HAVE_PPSRATECHECK
2696 #ifndef timersub
2697 #define	timersub(tvp, uvp, vvp)						\
2698 	do {								\
2699 		(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
2700 		(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
2701 		if ((vvp)->tv_usec < 0) {				\
2702 			(vvp)->tv_sec--;				\
2703 			(vvp)->tv_usec += 1000000;			\
2704 		}							\
2705 	} while (0)
2706 #endif
2707 
2708 /*
2709  * ppsratecheck(): packets (or events) per second limitation.
2710  */
2711 static int
2712 ppsratecheck(struct timeval *lasttime, int *curpps,
2713 	     int maxpps)	/* maximum pps allowed */
2714 {
2715 	struct timeval tv, delta;
2716 	int rv;
2717 
2718 	microtime(&tv);
2719 
2720 	timersub(&tv, lasttime, &delta);
2721 
2722 	/*
2723 	 * Check for 0,0 so that the message will be seen at least once.
2724 	 * If more than one second has passed since the last update of
2725 	 * lasttime, reset the counter.
2726 	 *
2727 	 * We do increment *curpps even in *curpps < maxpps case, as some may
2728 	 * try to use *curpps for stat purposes as well.
2729 	 */
2730 	if ((lasttime->tv_sec == 0 && lasttime->tv_usec == 0) ||
2731 	    delta.tv_sec >= 1) {
2732 		*lasttime = tv;
2733 		*curpps = 0;
2734 		rv = 1;
2735 	} else if (maxpps < 0)
2736 		rv = 1;
2737 	else if (*curpps < maxpps)
2738 		rv = 1;
2739 	else
2740 		rv = 0;
2741 
2742 #if 1 /* DIAGNOSTIC? */
2743 	/* be careful about wrap-around */
2744 	if (*curpps + 1 > *curpps)
2745 		*curpps = *curpps + 1;
2746 #else
2747 	/*
2748 	 * assume that there's not too many calls to this function.
2749 	 * not sure if the assumption holds, as it depends on *caller's*
2750 	 * behavior, not the behavior of this function.
2751 	 * IMHO it is wrong to make assumption on the caller's behavior,
2752 	 * so the above #if is #if 1, not #ifdef DIAGNOSTIC.
2753 	 */
2754 	*curpps = *curpps + 1;
2755 #endif
2756 
2757 	return (rv);
2758 }
2759 #endif
2760 
2761 /*
2762  * Perform rate limit check.
2763  * Returns 0 if it is okay to send the icmp6 packet.
2764  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2765  * limitation.
2766  *
2767  * XXX per-destination/type check necessary?
2768  */
2769 static int
2770 icmp6_ratelimit(const struct in6_addr *dst,	/* not used at this moment */
2771 		const int type,			/* not used at this moment */
2772 		const int code)			/* not used at this moment */
2773 {
2774 	int ret;
2775 
2776 	ret = 0;	/* okay to send */
2777 
2778 	/* PPS limit */
2779 	if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count,
2780 	    icmp6errppslim)) {
2781 		/* The packet is subject to rate limit */
2782 		ret++;
2783 	}
2784 
2785 	return ret;
2786 }
2787