xref: /netbsd-src/sys/netinet6/icmp6.c (revision 7cc2f76925f078d01ddc9e640a98f4ccfc9f8c3b)
1 /*	$NetBSD: icmp6.c,v 1.49 2000/12/11 19:28:47 itojun Exp $	*/
2 /*	$KAME: icmp6.c,v 1.172 2000/12/11 19:27:06 itojun Exp $	*/
3 
4 /*
5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (c) 1982, 1986, 1988, 1993
35  *	The Regents of the University of California.  All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. All advertising materials mentioning features or use of this software
46  *    must display the following acknowledgement:
47  *	This product includes software developed by the University of
48  *	California, Berkeley and its contributors.
49  * 4. Neither the name of the University nor the names of its contributors
50  *    may be used to endorse or promote products derived from this software
51  *    without specific prior written permission.
52  *
53  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63  * SUCH DAMAGE.
64  *
65  *	@(#)ip_icmp.c	8.2 (Berkeley) 1/4/94
66  */
67 
68 #include "opt_inet.h"
69 #include "opt_ipsec.h"
70 
71 #include <sys/param.h>
72 #include <sys/systm.h>
73 #include <sys/malloc.h>
74 #include <sys/mbuf.h>
75 #include <sys/protosw.h>
76 #include <sys/socket.h>
77 #include <sys/socketvar.h>
78 #include <sys/time.h>
79 #include <sys/kernel.h>
80 #include <sys/syslog.h>
81 #include <sys/domain.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 
100 #ifdef IPSEC
101 #include <netinet6/ipsec.h>
102 #include <netkey/key.h>
103 #endif
104 
105 #include "faith.h"
106 
107 #include <net/net_osdep.h>
108 
109 extern struct domain inet6domain;
110 
111 struct icmp6stat icmp6stat;
112 
113 extern struct in6pcb rawin6pcb;
114 extern int icmp6errppslim;
115 static int icmp6errpps_count = 0;
116 static struct timeval icmp6errppslim_last;
117 extern int icmp6_nodeinfo;
118 
119 /*
120  * List of callbacks to notify when Path MTU changes are made.
121  */
122 struct icmp6_mtudisc_callback {
123 	LIST_ENTRY(icmp6_mtudisc_callback) mc_list;
124 	void (*mc_func) __P((struct in6_addr *));
125 };
126 
127 LIST_HEAD(, icmp6_mtudisc_callback) icmp6_mtudisc_callbacks =
128     LIST_HEAD_INITIALIZER(&icmp6_mtudisc_callbacks);
129 
130 static struct rttimer_queue *icmp6_mtudisc_timeout_q = NULL;
131 extern int pmtu_expire;
132 
133 /* XXX do these values make any sense? */
134 int icmp6_mtudisc_hiwat = 1280;
135 int icmp6_mtudisc_lowat = 256;
136 
137 static void icmp6_errcount __P((struct icmp6errstat *, int, int));
138 static int icmp6_rip6_input __P((struct mbuf **, int));
139 static int icmp6_ratelimit __P((const struct in6_addr *, const int, const int));
140 static const char *icmp6_redirect_diag __P((struct in6_addr *,
141 	struct in6_addr *, struct in6_addr *));
142 static struct mbuf *ni6_input __P((struct mbuf *, int));
143 static struct mbuf *ni6_nametodns __P((const char *, int, int));
144 static int ni6_dnsmatch __P((const char *, int, const char *, int));
145 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *,
146 			  struct ifnet **, char *));
147 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
148 				struct ifnet *, int));
149 static struct rtentry *icmp6_mtudisc_clone __P((struct sockaddr *));
150 static void icmp6_mtudisc_timeout __P((struct rtentry *, struct rttimer *));
151 
152 #ifdef COMPAT_RFC1885
153 static struct route_in6 icmp6_reflect_rt;
154 #endif
155 
156 void
157 icmp6_init()
158 {
159 	mld6_init();
160 	icmp6_mtudisc_timeout_q = rt_timer_queue_create(pmtu_expire);
161 }
162 
163 static void
164 icmp6_errcount(stat, type, code)
165 	struct icmp6errstat *stat;
166 	int type, code;
167 {
168 	switch(type) {
169 	case ICMP6_DST_UNREACH:
170 		switch (code) {
171 		case ICMP6_DST_UNREACH_NOROUTE:
172 			stat->icp6errs_dst_unreach_noroute++;
173 			return;
174 		case ICMP6_DST_UNREACH_ADMIN:
175 			stat->icp6errs_dst_unreach_admin++;
176 			return;
177 		case ICMP6_DST_UNREACH_BEYONDSCOPE:
178 			stat->icp6errs_dst_unreach_beyondscope++;
179 			return;
180 		case ICMP6_DST_UNREACH_ADDR:
181 			stat->icp6errs_dst_unreach_addr++;
182 			return;
183 		case ICMP6_DST_UNREACH_NOPORT:
184 			stat->icp6errs_dst_unreach_noport++;
185 			return;
186 		}
187 		break;
188 	case ICMP6_PACKET_TOO_BIG:
189 		stat->icp6errs_packet_too_big++;
190 		return;
191 	case ICMP6_TIME_EXCEEDED:
192 		switch(code) {
193 		case ICMP6_TIME_EXCEED_TRANSIT:
194 			stat->icp6errs_time_exceed_transit++;
195 			return;
196 		case ICMP6_TIME_EXCEED_REASSEMBLY:
197 			stat->icp6errs_time_exceed_reassembly++;
198 			return;
199 		}
200 		break;
201 	case ICMP6_PARAM_PROB:
202 		switch(code) {
203 		case ICMP6_PARAMPROB_HEADER:
204 			stat->icp6errs_paramprob_header++;
205 			return;
206 		case ICMP6_PARAMPROB_NEXTHEADER:
207 			stat->icp6errs_paramprob_nextheader++;
208 			return;
209 		case ICMP6_PARAMPROB_OPTION:
210 			stat->icp6errs_paramprob_option++;
211 			return;
212 		}
213 		break;
214 	case ND_REDIRECT:
215 		stat->icp6errs_redirect++;
216 		return;
217 	}
218 	stat->icp6errs_unknown++;
219 }
220 
221 /*
222  * Register a Path MTU Discovery callback.
223  */
224 void
225 icmp6_mtudisc_callback_register(func)
226 	void (*func) __P((struct in6_addr *));
227 {
228 	struct icmp6_mtudisc_callback *mc;
229 
230 	for (mc = LIST_FIRST(&icmp6_mtudisc_callbacks); mc != NULL;
231 	     mc = LIST_NEXT(mc, mc_list)) {
232 		if (mc->mc_func == func)
233 			return;
234 	}
235 
236 	mc = malloc(sizeof(*mc), M_PCB, M_NOWAIT);
237 	if (mc == NULL)
238 		panic("icmp6_mtudisc_callback_register");
239 
240 	mc->mc_func = func;
241 	LIST_INSERT_HEAD(&icmp6_mtudisc_callbacks, mc, mc_list);
242 }
243 
244 /*
245  * Generate an error packet of type error in response to bad IP6 packet.
246  */
247 void
248 icmp6_error(m, type, code, param)
249 	struct mbuf *m;
250 	int type, code, param;
251 {
252 	struct ip6_hdr *oip6, *nip6;
253 	struct icmp6_hdr *icmp6;
254 	u_int preplen;
255 	int off;
256 	int nxt;
257 
258 	icmp6stat.icp6s_error++;
259 
260 	/* count per-type-code statistics */
261 	icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code);
262 
263 	if (m->m_flags & M_DECRYPTED) {
264 		icmp6stat.icp6s_canterror++;
265 		goto freeit;
266 	}
267 
268 #ifndef PULLDOWN_TEST
269 	IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
270 #else
271 	if (m->m_len < sizeof(struct ip6_hdr)) {
272 		m = m_pullup(m, sizeof(struct ip6_hdr));
273 		if (m == NULL)
274 			return;
275 	}
276 #endif
277 	oip6 = mtod(m, struct ip6_hdr *);
278 
279 	/*
280 	 * Multicast destination check. For unrecognized option errors,
281 	 * this check has already done in ip6_unknown_opt(), so we can
282 	 * check only for other errors.
283 	 */
284 	if ((m->m_flags & (M_BCAST|M_MCAST) ||
285 	     IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
286 	    (type != ICMP6_PACKET_TOO_BIG &&
287 	     (type != ICMP6_PARAM_PROB ||
288 	      code != ICMP6_PARAMPROB_OPTION)))
289 		goto freeit;
290 
291 	/* Source address check. XXX: the case of anycast source? */
292 	if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
293 	    IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
294 		goto freeit;
295 
296 	/*
297 	 * If we are about to send ICMPv6 against ICMPv6 error/redirect,
298 	 * don't do it.
299 	 */
300 	nxt = -1;
301 	off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
302 	if (off >= 0 && nxt == IPPROTO_ICMPV6) {
303 		struct icmp6_hdr *icp;
304 
305 #ifndef PULLDOWN_TEST
306 		IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
307 		icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
308 #else
309 		IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
310 			sizeof(*icp));
311 		if (icp == NULL) {
312 			icmp6stat.icp6s_tooshort++;
313 			return;
314 		}
315 #endif
316 		if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
317 		    icp->icmp6_type == ND_REDIRECT) {
318 			/*
319 			 * ICMPv6 error
320 			 * Special case: for redirect (which is
321 			 * informational) we must not send icmp6 error.
322 			 */
323 			icmp6stat.icp6s_canterror++;
324 			goto freeit;
325 		} else {
326 			/* ICMPv6 informational - send the error */
327 		}
328 	} else {
329 		/* non-ICMPv6 - send the error */
330 	}
331 
332 	oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
333 
334 	/* Finally, do rate limitation check. */
335 	if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
336 		icmp6stat.icp6s_toofreq++;
337 		goto freeit;
338 	}
339 
340 	/*
341 	 * OK, ICMP6 can be generated.
342 	 */
343 
344 	if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
345 		m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
346 
347 	preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
348 	M_PREPEND(m, preplen, M_DONTWAIT);
349 	if (m && m->m_len < preplen)
350 		m = m_pullup(m, preplen);
351 	if (m == NULL) {
352 		printf("ENOBUFS in icmp6_error %d\n", __LINE__);
353 		return;
354 	}
355 
356 	nip6 = mtod(m, struct ip6_hdr *);
357 	nip6->ip6_src  = oip6->ip6_src;
358 	nip6->ip6_dst  = oip6->ip6_dst;
359 
360 	if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
361 		oip6->ip6_src.s6_addr16[1] = 0;
362 	if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
363 		oip6->ip6_dst.s6_addr16[1] = 0;
364 
365 	icmp6 = (struct icmp6_hdr *)(nip6 + 1);
366 	icmp6->icmp6_type = type;
367 	icmp6->icmp6_code = code;
368 	icmp6->icmp6_pptr = htonl((u_int32_t)param);
369 
370 	icmp6stat.icp6s_outhist[type]++;
371 	icmp6_reflect(m, sizeof(struct ip6_hdr)); /*header order: IPv6 - ICMPv6*/
372 
373 	return;
374 
375   freeit:
376 	/*
377 	 * If we can't tell wheter or not we can generate ICMP6, free it.
378 	 */
379 	m_freem(m);
380 }
381 
382 /*
383  * Process a received ICMP6 message.
384  */
385 int
386 icmp6_input(mp, offp, proto)
387 	struct mbuf **mp;
388 	int *offp, proto;
389 {
390 	struct mbuf *m = *mp, *n;
391 	struct ip6_hdr *ip6, *nip6;
392 	struct icmp6_hdr *icmp6, *nicmp6;
393 	int off = *offp;
394 	int icmp6len = m->m_pkthdr.len - *offp;
395 	int code, sum, noff;
396 	struct sockaddr_in6 icmp6src;
397 
398 #ifndef PULLDOWN_TEST
399 	IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
400 	/* m might change if M_LOOP. So, call mtod after this */
401 #endif
402 
403 	/*
404 	 * Locate icmp6 structure in mbuf, and check
405 	 * that not corrupted and of at least minimum length
406 	 */
407 
408 	ip6 = mtod(m, struct ip6_hdr *);
409 	if (icmp6len < sizeof(struct icmp6_hdr)) {
410 		icmp6stat.icp6s_tooshort++;
411 		goto freeit;
412 	}
413 
414 	/*
415 	 * calculate the checksum
416 	 */
417 #ifndef PULLDOWN_TEST
418 	icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
419 #else
420 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
421 	if (icmp6 == NULL) {
422 		icmp6stat.icp6s_tooshort++;
423 		return IPPROTO_DONE;
424 	}
425 #endif
426 	code = icmp6->icmp6_code;
427 
428 	if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
429 		log(LOG_ERR,
430 		    "ICMP6 checksum error(%d|%x) %s\n",
431 		    icmp6->icmp6_type,
432 		    sum,
433 		    ip6_sprintf(&ip6->ip6_src));
434 		icmp6stat.icp6s_checksum++;
435 		goto freeit;
436 	}
437 
438 #if defined(NFAITH) && 0 < NFAITH
439 	if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
440 		/*
441 		 * Deliver very specific ICMP6 type only.
442 		 * This is important to deilver TOOBIG.  Otherwise PMTUD
443 		 * will not work.
444 		 */
445 		switch (icmp6->icmp6_type) {
446 		case ICMP6_DST_UNREACH:
447 		case ICMP6_PACKET_TOO_BIG:
448 		case ICMP6_TIME_EXCEEDED:
449 			break;
450 		default:
451 			goto freeit;
452 		}
453 	}
454 #endif
455 
456 #ifdef IPSEC
457 	/* drop it if it does not match the default policy */
458 	if (ipsec6_in_reject(m, NULL)) {
459 		ipsec6stat.in_polvio++;
460 		goto freeit;
461 	}
462 #endif
463 
464 	icmp6stat.icp6s_inhist[icmp6->icmp6_type]++;
465 	icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg);
466 	if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
467 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
468 
469 	switch (icmp6->icmp6_type) {
470 
471 	case ICMP6_DST_UNREACH:
472 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach);
473 		switch (code) {
474 		case ICMP6_DST_UNREACH_NOROUTE:
475 			code = PRC_UNREACH_NET;
476 			break;
477 		case ICMP6_DST_UNREACH_ADMIN:
478 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib);
479 			code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
480 			break;
481 		case ICMP6_DST_UNREACH_ADDR:
482 			code = PRC_HOSTDEAD;
483 			break;
484 #ifdef COMPAT_RFC1885
485 		case ICMP6_DST_UNREACH_NOTNEIGHBOR:
486 			code = PRC_UNREACH_SRCFAIL;
487 			break;
488 #else
489 		case ICMP6_DST_UNREACH_BEYONDSCOPE:
490 			/* I mean "source address was incorrect." */
491 			code = PRC_PARAMPROB;
492 			break;
493 #endif
494 		case ICMP6_DST_UNREACH_NOPORT:
495 			code = PRC_UNREACH_PORT;
496 			break;
497 		default:
498 			goto badcode;
499 		}
500 		goto deliver;
501 		break;
502 
503 	case ICMP6_PACKET_TOO_BIG:
504 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig);
505 		if (code != 0)
506 			goto badcode;
507 
508 		code = PRC_MSGSIZE;
509 
510 		/*
511 		 * Updating the path MTU will be done after examining
512 		 * intermediate extension headers.
513 		 */
514 		goto deliver;
515 		break;
516 
517 	case ICMP6_TIME_EXCEEDED:
518 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed);
519 		switch (code) {
520 		case ICMP6_TIME_EXCEED_TRANSIT:
521 		case ICMP6_TIME_EXCEED_REASSEMBLY:
522 			code += PRC_TIMXCEED_INTRANS;
523 			break;
524 		default:
525 			goto badcode;
526 		}
527 		goto deliver;
528 		break;
529 
530 	case ICMP6_PARAM_PROB:
531 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob);
532 		switch (code) {
533 		case ICMP6_PARAMPROB_NEXTHEADER:
534 			code = PRC_UNREACH_PROTOCOL;
535 			break;
536 		case ICMP6_PARAMPROB_HEADER:
537 		case ICMP6_PARAMPROB_OPTION:
538 			code = PRC_PARAMPROB;
539 			break;
540 		default:
541 			goto badcode;
542 		}
543 		goto deliver;
544 		break;
545 
546 	case ICMP6_ECHO_REQUEST:
547 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo);
548 		if (code != 0)
549 			goto badcode;
550 		if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
551 			/* Give up remote */
552 			break;
553 		}
554 		if ((n->m_flags & M_EXT) != 0
555 		 || n->m_len < off + sizeof(struct icmp6_hdr)) {
556 			struct mbuf *n0 = n;
557 			const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
558 
559 			/*
560 			 * Prepare an internal mbuf. m_pullup() doesn't
561 			 * always copy the length we specified.
562 			 */
563 			if (maxlen >= MCLBYTES) {
564 #ifdef DIAGNOSTIC
565 				printf("MCLBYTES too small\n");
566 #endif
567 				/* Give up remote */
568 				m_freem(n0);
569 				break;
570 			}
571 			MGETHDR(n, M_DONTWAIT, n0->m_type);
572 			if (n && maxlen >= MHLEN) {
573 				MCLGET(n, M_DONTWAIT);
574 				if ((n->m_flags & M_EXT) == 0) {
575 					m_free(n);
576 					n = NULL;
577 				}
578 			}
579 			if (n == NULL) {
580 				/* Give up remote */
581 				m_freem(n0);
582 				break;
583 			}
584 			M_COPY_PKTHDR(n, n0);
585 			/*
586 			 * Copy IPv6 and ICMPv6 only.
587 			 */
588 			nip6 = mtod(n, struct ip6_hdr *);
589 			bcopy(ip6, nip6, sizeof(struct ip6_hdr));
590 			nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
591 			bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
592 			noff = sizeof(struct ip6_hdr);
593 			n->m_pkthdr.len = n->m_len =
594 				noff + sizeof(struct icmp6_hdr);
595 			/*
596 			 * Adjust mbuf. ip6_plen will be adjusted in
597 			 * ip6_output().
598 			 */
599 			m_adj(n0, off + sizeof(struct icmp6_hdr));
600 			n->m_pkthdr.len += n0->m_pkthdr.len;
601 			n->m_next = n0;
602 			n0->m_flags &= ~M_PKTHDR;
603 		} else {
604 			nip6 = mtod(n, struct ip6_hdr *);
605 			nicmp6 = (struct icmp6_hdr *)((caddr_t)nip6 + off);
606 			noff = off;
607 		}
608 		nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
609 		nicmp6->icmp6_code = 0;
610 		if (n) {
611 			icmp6stat.icp6s_reflect++;
612 			icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++;
613 			icmp6_reflect(n, noff);
614 		}
615 		break;
616 
617 	case ICMP6_ECHO_REPLY:
618 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply);
619 		if (code != 0)
620 			goto badcode;
621 		break;
622 
623 	case MLD6_LISTENER_QUERY:
624 	case MLD6_LISTENER_REPORT:
625 		if (icmp6len < sizeof(struct mld6_hdr))
626 			goto badlen;
627 		if (icmp6->icmp6_type == MLD6_LISTENER_QUERY) /* XXX: ugly... */
628 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery);
629 		else
630 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport);
631 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
632 			/* give up local */
633 			mld6_input(m, off);
634 			m = NULL;
635 			goto freeit;
636 		}
637 		mld6_input(n, off);
638 		/* m stays. */
639 		break;
640 
641 	case MLD6_LISTENER_DONE:
642 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone);
643 		if (icmp6len < sizeof(struct mld6_hdr))	/* necessary? */
644 			goto badlen;
645 		break;		/* nothing to be done in kernel */
646 
647 	case MLD6_MTRACE_RESP:
648 	case MLD6_MTRACE:
649 		/* XXX: these two are experimental. not officially defind. */
650 		/* XXX: per-interface statistics? */
651 		break;		/* just pass it to applications */
652 
653 	case ICMP6_WRUREQUEST:	/* ICMP6_FQDN_QUERY */
654 	    {
655 		enum { WRU, FQDN } mode;
656 
657 		if (!icmp6_nodeinfo)
658 			break;
659 
660 		if (icmp6len == sizeof(struct icmp6_hdr) + 4)
661 			mode = WRU;
662 		else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
663 			mode = FQDN;
664 		else
665 			goto badlen;
666 
667 		if (mode == FQDN) {
668 #ifndef PULLDOWN_TEST
669 			IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
670 					 IPPROTO_DONE);
671 #endif
672 			n = m_copy(m, 0, M_COPYALL);
673 			if (n)
674 				n = ni6_input(n, off);
675 			/* XXX meaningless if n == NULL */
676 			noff = sizeof(struct ip6_hdr);
677 		} else {
678 			u_char *p;
679 			int maxlen, maxhlen;
680 
681 			if (code != 0)
682 				goto badcode;
683 			maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
684 			if (maxlen >= MCLBYTES) {
685 #ifdef DIAGNOSTIC
686 				printf("MCLBYTES too small\n");
687 #endif
688 				/* Give up remote */
689 				break;
690 			}
691 			MGETHDR(n, M_DONTWAIT, m->m_type);
692 			if (n && maxlen > MHLEN) {
693 				MCLGET(n, M_DONTWAIT);
694 				if ((n->m_flags & M_EXT) == 0) {
695 					m_free(n);
696 					n = NULL;
697 				}
698 			}
699 			if (n == NULL) {
700 				/* Give up remote */
701 				break;
702 			}
703 			n->m_len = 0;
704 			maxhlen = M_TRAILINGSPACE(n) - maxlen;
705 			if (maxhlen > hostnamelen)
706 				maxhlen = hostnamelen;
707 			/*
708 			 * Copy IPv6 and ICMPv6 only.
709 			 */
710 			nip6 = mtod(n, struct ip6_hdr *);
711 			bcopy(ip6, nip6, sizeof(struct ip6_hdr));
712 			nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
713 			bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
714 			p = (u_char *)(nicmp6 + 1);
715 			bzero(p, 4);
716 			bcopy(hostname, p + 4, maxhlen); /*meaningless TTL*/
717 			noff = sizeof(struct ip6_hdr);
718 			M_COPY_PKTHDR(n, m); /* just for recvif */
719 			n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
720 				sizeof(struct icmp6_hdr) + 4 + maxhlen;
721 			nicmp6->icmp6_type = ICMP6_WRUREPLY;
722 			nicmp6->icmp6_code = 0;
723 		}
724 #undef hostnamelen
725 		if (n) {
726 			icmp6stat.icp6s_reflect++;
727 			icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++;
728 			icmp6_reflect(n, noff);
729 		}
730 		break;
731 	    }
732 
733 	case ICMP6_WRUREPLY:
734 		if (code != 0)
735 			goto badcode;
736 		break;
737 
738 	case ND_ROUTER_SOLICIT:
739 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit);
740 		if (code != 0)
741 			goto badcode;
742 		if (icmp6len < sizeof(struct nd_router_solicit))
743 			goto badlen;
744 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
745 			/* give up local */
746 			nd6_rs_input(m, off, icmp6len);
747 			m = NULL;
748 			goto freeit;
749 		}
750 		nd6_rs_input(n, off, icmp6len);
751 		/* m stays. */
752 		break;
753 
754 	case ND_ROUTER_ADVERT:
755 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert);
756 		if (code != 0)
757 			goto badcode;
758 		if (icmp6len < sizeof(struct nd_router_advert))
759 			goto badlen;
760 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
761 			/* give up local */
762 			nd6_ra_input(m, off, icmp6len);
763 			m = NULL;
764 			goto freeit;
765 		}
766 		nd6_ra_input(n, off, icmp6len);
767 		/* m stays. */
768 		break;
769 
770 	case ND_NEIGHBOR_SOLICIT:
771 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit);
772 		if (code != 0)
773 			goto badcode;
774 		if (icmp6len < sizeof(struct nd_neighbor_solicit))
775 			goto badlen;
776 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
777 			/* give up local */
778 			nd6_ns_input(m, off, icmp6len);
779 			m = NULL;
780 			goto freeit;
781 		}
782 		nd6_ns_input(n, off, icmp6len);
783 		/* m stays. */
784 		break;
785 
786 	case ND_NEIGHBOR_ADVERT:
787 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert);
788 		if (code != 0)
789 			goto badcode;
790 		if (icmp6len < sizeof(struct nd_neighbor_advert))
791 			goto badlen;
792 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
793 			/* give up local */
794 			nd6_na_input(m, off, icmp6len);
795 			m = NULL;
796 			goto freeit;
797 		}
798 		nd6_na_input(n, off, icmp6len);
799 		/* m stays. */
800 		break;
801 
802 	case ND_REDIRECT:
803 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect);
804 		if (code != 0)
805 			goto badcode;
806 		if (icmp6len < sizeof(struct nd_redirect))
807 			goto badlen;
808 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
809 			/* give up local */
810 			icmp6_redirect_input(m, off);
811 			m = NULL;
812 			goto freeit;
813 		}
814 		icmp6_redirect_input(n, off);
815 		/* m stays. */
816 		break;
817 
818 	case ICMP6_ROUTER_RENUMBERING:
819 		if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
820 		    code != ICMP6_ROUTER_RENUMBERING_RESULT)
821 			goto badcode;
822 		if (icmp6len < sizeof(struct icmp6_router_renum))
823 			goto badlen;
824 		break;
825 
826 	default:
827 		printf("icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
828 		       icmp6->icmp6_type, ip6_sprintf(&ip6->ip6_src),
829 		       ip6_sprintf(&ip6->ip6_dst),
830 		       m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0);
831 		if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
832 			/* ICMPv6 error: MUST deliver it by spec... */
833 			code = PRC_NCMDS;
834 			/* deliver */
835 		} else {
836 			/* ICMPv6 informational: MUST not deliver */
837 			break;
838 		}
839 	deliver:
840 		if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
841 			icmp6stat.icp6s_tooshort++;
842 			goto freeit;
843 		}
844 #ifndef PULLDOWN_TEST
845 		IP6_EXTHDR_CHECK(m, off,
846 			sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr),
847 			IPPROTO_DONE);
848 		icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
849 #else
850 		IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
851 			sizeof(*icmp6) + sizeof(struct ip6_hdr));
852 		if (icmp6 == NULL) {
853 			icmp6stat.icp6s_tooshort++;
854 			return IPPROTO_DONE;
855 		}
856 #endif
857 		bzero(&icmp6src, sizeof(icmp6src));
858 		icmp6src.sin6_len = sizeof(struct sockaddr_in6);
859 		icmp6src.sin6_family = AF_INET6;
860 		icmp6src.sin6_addr = ((struct ip6_hdr *)(icmp6 + 1))->ip6_dst;
861 
862 		/* Detect the upper level protocol */
863 	    {
864 		void (*ctlfunc) __P((int, struct sockaddr *, void *));
865 		struct ip6_hdr *eip6 = (struct ip6_hdr *)(icmp6 + 1);
866 		u_int8_t nxt = eip6->ip6_nxt;
867 		int eoff = off + sizeof(struct icmp6_hdr) +
868 			sizeof(struct ip6_hdr);
869 		struct ip6ctlparam ip6cp;
870 		struct in6_addr *finaldst = NULL;
871 		struct ip6_frag *fh;
872 		struct ip6_rthdr *rth;
873 		struct ip6_rthdr0 *rth0;
874 		int rthlen;
875 
876 		while (1) { /* XXX: should avoid inf. loop explicitly? */
877 			struct ip6_ext *eh;
878 
879 			switch(nxt) {
880 			case IPPROTO_HOPOPTS:
881 			case IPPROTO_DSTOPTS:
882 			case IPPROTO_AH:
883 #ifndef PULLDOWN_TEST
884 				IP6_EXTHDR_CHECK(m, 0, eoff +
885 						 sizeof(struct ip6_ext),
886 						 IPPROTO_DONE);
887 				eh = (struct ip6_ext *)(mtod(m, caddr_t)
888 							+ eoff);
889 #else
890 				IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
891 					eoff, sizeof(*eh));
892 				if (eh == NULL) {
893 					icmp6stat.icp6s_tooshort++;
894 					return IPPROTO_DONE;
895 				}
896 #endif
897 
898 				if (nxt == IPPROTO_AH)
899 					eoff += (eh->ip6e_len + 2) << 2;
900 				else
901 					eoff += (eh->ip6e_len + 1) << 3;
902 				nxt = eh->ip6e_nxt;
903 				break;
904 			case IPPROTO_ROUTING:
905 				/*
906 				 * When the erroneous packet contains a
907 				 * routing header, we should examine the
908 				 * header to determine the final destination.
909 				 * Otherwise, we can't properly update
910 				 * information that depends on the final
911 				 * destination (e.g. path MTU).
912 				 */
913 #ifndef PULLDOWN_TEST
914 				IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth),
915 						 IPPROTO_DONE);
916 				rth = (struct ip6_rthdr *)(mtod(m, caddr_t)
917 							   + eoff);
918 #else
919 				IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
920 					eoff, sizeof(*rth));
921 				if (rth == NULL) {
922 					icmp6stat.icp6s_tooshort++;
923 					return IPPROTO_DONE;
924 				}
925 #endif
926 				rthlen = (rth->ip6r_len + 1) << 3;
927 				/*
928 				 * XXX: currently there is no
929 				 * officially defined type other
930 				 * than type-0.
931 				 * Note that if the segment left field
932 				 * is 0, all intermediate hops must
933 				 * have been passed.
934 				 */
935 				if (rth->ip6r_segleft &&
936 				    rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
937 					int hops;
938 
939 #ifndef PULLDOWN_TEST
940 					IP6_EXTHDR_CHECK(m, 0, eoff + rthlen,
941 							 IPPROTO_DONE);
942 					rth0 = (struct ip6_rthdr0 *)(mtod(m, caddr_t) + eoff);
943 #else
944 					IP6_EXTHDR_GET(rth0,
945 						       struct ip6_rthdr0 *, m,
946 						       eoff, rthlen);
947 					if (rth0 == NULL) {
948 						icmp6stat.icp6s_tooshort++;
949 						return IPPROTO_DONE;
950 					}
951 #endif
952 					/* just ignore a bogus header */
953 					if ((rth0->ip6r0_len % 2) == 0 &&
954 					    (hops = rth0->ip6r0_len/2))
955 						finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
956 				}
957 				eoff += rthlen;
958 				nxt = rth->ip6r_nxt;
959 				break;
960 			case IPPROTO_FRAGMENT:
961 #ifndef PULLDOWN_TEST
962 				IP6_EXTHDR_CHECK(m, 0, eoff +
963 						 sizeof(struct ip6_frag),
964 						 IPPROTO_DONE);
965 				fh = (struct ip6_frag *)(mtod(m, caddr_t)
966 							 + eoff);
967 #else
968 				IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
969 					eoff, sizeof(*fh));
970 				if (fh == NULL) {
971 					icmp6stat.icp6s_tooshort++;
972 					return IPPROTO_DONE;
973 				}
974 #endif
975 				/*
976 				 * Data after a fragment header is meaningless
977 				 * unless it is the first fragment, but
978 				 * we'll go to the notify label for path MTU
979 				 * discovery.
980 				 */
981 				if (fh->ip6f_offlg & IP6F_OFF_MASK)
982 					goto notify;
983 
984 				eoff += sizeof(struct ip6_frag);
985 				nxt = fh->ip6f_nxt;
986 				break;
987 			default:
988 				/*
989 				 * This case includes ESP and the No Next
990 				 * Header. In such cases going to the notify
991 				 * label does not have any meaning
992 				 * (i.e. ctlfunc will be NULL), but we go
993 				 * anyway since we might have to update
994 				 * path MTU information.
995 				 */
996 				goto notify;
997 			}
998 		}
999 	    notify:
1000 #ifndef PULLDOWN_TEST
1001 		icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1002 #else
1003 		IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1004 			sizeof(*icmp6) + sizeof(struct ip6_hdr));
1005 		if (icmp6 == NULL) {
1006 			icmp6stat.icp6s_tooshort++;
1007 			return IPPROTO_DONE;
1008 		}
1009 #endif
1010 		if (finaldst == NULL)
1011 			finaldst = &((struct ip6_hdr *)(icmp6 + 1))->ip6_dst;
1012 		ip6cp.ip6c_m = m;
1013 		ip6cp.ip6c_icmp6 = icmp6;
1014 		ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1015 		ip6cp.ip6c_off = eoff;
1016 		ip6cp.ip6c_finaldst = finaldst;
1017 
1018 		ctlfunc = (void (*) __P((int, struct sockaddr *, void *)))
1019 			(inet6sw[ip6_protox[nxt]].pr_ctlinput);
1020 		if (ctlfunc) {
1021 			(void) (*ctlfunc)(code, (struct sockaddr *)&icmp6src,
1022 			    &ip6cp);
1023 		}
1024 	    }
1025 		break;
1026 
1027 	badcode:
1028 		icmp6stat.icp6s_badcode++;
1029 		break;
1030 
1031 	badlen:
1032 		icmp6stat.icp6s_badlen++;
1033 		break;
1034 	}
1035 
1036 	icmp6_rip6_input(&m, *offp);
1037 	return IPPROTO_DONE;
1038 
1039  freeit:
1040 	m_freem(m);
1041 	return IPPROTO_DONE;
1042 }
1043 
1044 void
1045 icmp6_mtudisc_update(ip6cp, validated)
1046 	struct ip6ctlparam *ip6cp;
1047 	int validated;
1048 {
1049 	unsigned long rtcount;
1050 	struct icmp6_mtudisc_callback *mc;
1051 	struct in6_addr *dst = ip6cp->ip6c_finaldst;
1052 	struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1053 	struct mbuf *m = ip6cp->ip6c_m;	/* will be necessary for scope issue */
1054 	u_int mtu = ntohl(icmp6->icmp6_mtu);
1055 	struct rtentry *rt = NULL;
1056 	struct sockaddr_in6 sin6;
1057 
1058 	/*
1059 	 * allow non-validated cases if memory is plenty, to make traffic
1060 	 * from non-connected pcb happy.
1061 	 */
1062 	rtcount = rt_timer_count(icmp6_mtudisc_timeout_q);
1063 	if (validated) {
1064 		if (rtcount > icmp6_mtudisc_hiwat)
1065 			return;
1066 		else if (rtcount > icmp6_mtudisc_lowat) {
1067 			/*
1068 			 * XXX nuke a victim, install the new one.
1069 			 */
1070 		}
1071 	} else {
1072 		if (rtcount > icmp6_mtudisc_lowat)
1073 			return;
1074 	}
1075 
1076 	bzero(&sin6, sizeof(sin6));
1077 	sin6.sin6_family = PF_INET6;
1078 	sin6.sin6_len = sizeof(struct sockaddr_in6);
1079 	sin6.sin6_addr = *dst;
1080 	/* XXX normally, this won't happen */
1081 	if (IN6_IS_ADDR_LINKLOCAL(dst)) {
1082 		sin6.sin6_addr.s6_addr16[1] =
1083 		    htons(m->m_pkthdr.rcvif->if_index);
1084 	}
1085 	/* sin6.sin6_scope_id = XXX: should be set if DST is a scoped addr */
1086 	rt = icmp6_mtudisc_clone((struct sockaddr *)&sin6);
1087 
1088 	if (rt && (rt->rt_flags & RTF_HOST)
1089 	    && !(rt->rt_rmx.rmx_locks & RTV_MTU)) {
1090 		if (mtu < IPV6_MMTU) {
1091 				/* xxx */
1092 			rt->rt_rmx.rmx_locks |= RTV_MTU;
1093 		} else if (mtu < rt->rt_ifp->if_mtu &&
1094 			   rt->rt_rmx.rmx_mtu > mtu) {
1095 			icmp6stat.icp6s_pmtuchg++;
1096 			rt->rt_rmx.rmx_mtu = mtu;
1097 		}
1098 	}
1099 	if (rt)
1100 		RTFREE(rt);
1101 
1102 	/*
1103 	 * Notify protocols that the MTU for this destination
1104 	 * has changed.
1105 	 */
1106 	for (mc = LIST_FIRST(&icmp6_mtudisc_callbacks); mc != NULL;
1107 	     mc = LIST_NEXT(mc, mc_list))
1108 		(*mc->mc_func)(&sin6.sin6_addr);
1109 }
1110 
1111 /*
1112  * Process a Node Information Query packet, based on
1113  * draft-ietf-ipngwg-icmp-name-lookups-07.
1114  *
1115  * Spec incompatibilities:
1116  * - IPv6 Subject address handling
1117  * - IPv4 Subject address handling support missing
1118  * - Proxy reply (answer even if it's not for me)
1119  * - joins NI group address at in6_ifattach() time only, does not cope
1120  *   with hostname changes by sethostname(3)
1121  */
1122 #ifndef offsetof		/* XXX */
1123 #define	offsetof(type, member)	((size_t)(&((type *)0)->member))
1124 #endif
1125 static struct mbuf *
1126 ni6_input(m, off)
1127 	struct mbuf *m;
1128 	int off;
1129 {
1130 	struct icmp6_nodeinfo *ni6, *nni6;
1131 	struct mbuf *n = NULL;
1132 	u_int16_t qtype;
1133 	int subjlen;
1134 	int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1135 	struct ni_reply_fqdn *fqdn;
1136 	int addrs;		/* for NI_QTYPE_NODEADDR */
1137 	struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1138 	struct sockaddr_in6 sin6; /* double meaning; ip6_dst and subjectaddr */
1139 	struct ip6_hdr *ip6;
1140 	int oldfqdn = 0;	/* if 1, return pascal string (03 draft) */
1141 	char *subj = NULL;
1142 
1143 	ip6 = mtod(m, struct ip6_hdr *);
1144 #ifndef PULLDOWN_TEST
1145 	ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1146 #else
1147 	IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1148 	if (ni6 == NULL) {
1149 		/* m is already reclaimed */
1150 		return NULL;
1151 	}
1152 #endif
1153 
1154 	/*
1155 	 * Validate IPv6 destination address.
1156 	 *
1157 	 * The Responder must discard the Query without further processing
1158 	 * unless it is one of the Responder's unicast or anycast addresses, or
1159 	 * a link-local scope multicast address which the Responder has joined.
1160 	 * [icmp-name-lookups-07, Section 4.]
1161 	 */
1162 	bzero(&sin6, sizeof(sin6));
1163 	sin6.sin6_family = AF_INET6;
1164 	sin6.sin6_len = sizeof(struct sockaddr_in6);
1165 	bcopy(&ip6->ip6_dst, &sin6.sin6_addr, sizeof(sin6.sin6_addr));
1166 	/* XXX scopeid */
1167 	if (ifa_ifwithaddr((struct sockaddr *)&sin6))
1168 		; /* unicast/anycast, fine */
1169 	else if (IN6_IS_ADDR_MC_LINKLOCAL(&sin6.sin6_addr))
1170 		; /* link-local multicast, fine */
1171 	else
1172 		goto bad;
1173 
1174 	/* validate query Subject field. */
1175 	qtype = ntohs(ni6->ni_qtype);
1176 	subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1177 	switch (qtype) {
1178 	case NI_QTYPE_NOOP:
1179 	case NI_QTYPE_SUPTYPES:
1180 		/* 07 draft */
1181 		if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1182 			break;
1183 		/*FALLTHROUGH*/
1184 	case NI_QTYPE_FQDN:
1185 	case NI_QTYPE_NODEADDR:
1186 		switch (ni6->ni_code) {
1187 		case ICMP6_NI_SUBJ_IPV6:
1188 #if ICMP6_NI_SUBJ_IPV6 != 0
1189 		case 0:
1190 #endif
1191 			/*
1192 			 * backward compatibility - try to accept 03 draft
1193 			 * format, where no Subject is present.
1194 			 */
1195 			if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1196 			    subjlen == 0) {
1197 				oldfqdn++;
1198 				break;
1199 			}
1200 #if ICMP6_NI_SUBJ_IPV6 != 0
1201 			if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1202 				goto bad;
1203 #endif
1204 
1205 			if (subjlen != sizeof(sin6.sin6_addr))
1206 				goto bad;
1207 
1208 			/*
1209 			 * Validate Subject address.
1210 			 *
1211 			 * Not sure what exactly does "address belongs to the
1212 			 * node" mean in the spec, is it just unicast, or what?
1213 			 *
1214 			 * At this moment we consider Subject address as
1215 			 * "belong to the node" if the Subject address equals
1216 			 * to the IPv6 destination address; validation for
1217 			 * IPv6 destination address should have done enough
1218 			 * check for us.
1219 			 *
1220 			 * We do not do proxy at this moment.
1221 			 */
1222 			/* m_pulldown instead of copy? */
1223 			m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1224 			    subjlen, (caddr_t)&sin6.sin6_addr);
1225 			/* XXX kame scope hack */
1226 			if (IN6_IS_SCOPE_LINKLOCAL(&sin6.sin6_addr)) {
1227 #ifdef FAKE_LOOPBACK_IF
1228 				if ((m->m_flags & M_PKTHDR) != 0 &&
1229 				    m->m_pkthdr.rcvif) {
1230 					sin6.sin6_addr.s6_addr16[1] =
1231 					    htons(m->m_pkthdr.rcvif->if_index);
1232 				}
1233 #else
1234 				if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
1235 					sin6.sin6_addr.s6_addr16[1] =
1236 					    ip6->ip6_dst.s6_addr16[1];
1237 				}
1238 #endif
1239 			}
1240 			subj = (char *)&sin6;
1241 			if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &sin6.sin6_addr))
1242 				break;
1243 
1244 			/*
1245 			 * XXX if we are to allow other cases, we should really
1246 			 * be careful about scope here.
1247 			 * basically, we should disallow queries toward IPv6
1248 			 * destination X with subject Y, if scope(X) > scope(Y).
1249 			 * if we allow scope(X) > scope(Y), it will result in
1250 			 * information leakage across scope boundary.
1251 			 */
1252 			goto bad;
1253 
1254 		case ICMP6_NI_SUBJ_FQDN:
1255 			/*
1256 			 * Validate Subject name with gethostname(3).
1257 			 *
1258 			 * The behavior may need some debate, since:
1259 			 * - we are not sure if the node has FQDN as
1260 			 *   hostname (returned by gethostname(3)).
1261 			 * - the code does wildcard match for truncated names.
1262 			 *   however, we are not sure if we want to perform
1263 			 *   wildcard match, if gethostname(3) side has
1264 			 *   truncated hostname.
1265 			 */
1266 			n = ni6_nametodns(hostname, hostnamelen, 0);
1267 			if (!n || n->m_next || n->m_len == 0)
1268 				goto bad;
1269 			IP6_EXTHDR_GET(subj, char *, m,
1270 			    off + sizeof(struct icmp6_nodeinfo), subjlen);
1271 			if (subj == NULL)
1272 				goto bad;
1273 			if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1274 					n->m_len)) {
1275 				goto bad;
1276 			}
1277 			m_freem(n);
1278 			n = NULL;
1279 			break;
1280 
1281 		case ICMP6_NI_SUBJ_IPV4:	/* XXX: to be implemented? */
1282 		default:
1283 			goto bad;
1284 		}
1285 		break;
1286 	}
1287 
1288 	/* guess reply length */
1289 	switch (qtype) {
1290 	case NI_QTYPE_NOOP:
1291 		break;		/* no reply data */
1292 	case NI_QTYPE_SUPTYPES:
1293 		replylen += sizeof(u_int32_t);
1294 		break;
1295 	case NI_QTYPE_FQDN:
1296 		/* XXX will append an mbuf */
1297 		replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1298 		break;
1299 	case NI_QTYPE_NODEADDR:
1300 		addrs = ni6_addrs(ni6, m, &ifp, subj);
1301 		if ((replylen += addrs * (sizeof(struct in6_addr) +
1302 					  sizeof(u_int32_t))) > MCLBYTES)
1303 			replylen = MCLBYTES; /* XXX: will truncate pkt later */
1304 		break;
1305 	default:
1306 		/*
1307 		 * XXX: We must return a reply with the ICMP6 code
1308 		 * `unknown Qtype' in this case. However we regard the case
1309 		 * as an FQDN query for backward compatibility.
1310 		 * Older versions set a random value to this field,
1311 		 * so it rarely varies in the defined qtypes.
1312 		 * But the mechanism is not reliable...
1313 		 * maybe we should obsolete older versions.
1314 		 */
1315 		qtype = NI_QTYPE_FQDN;
1316 		/* XXX will append an mbuf */
1317 		replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1318 		oldfqdn++;
1319 		break;
1320 	}
1321 
1322 	/* allocate an mbuf to reply. */
1323 	MGETHDR(n, M_DONTWAIT, m->m_type);
1324 	if (n == NULL) {
1325 		m_freem(m);
1326 		return(NULL);
1327 	}
1328 	M_COPY_PKTHDR(n, m); /* just for recvif */
1329 	if (replylen > MHLEN) {
1330 		if (replylen > MCLBYTES) {
1331 			 /*
1332 			  * XXX: should we try to allocate more? But MCLBYTES
1333 			  * is probably much larger than IPV6_MMTU...
1334 			  */
1335 			goto bad;
1336 		}
1337 		MCLGET(n, M_DONTWAIT);
1338 		if ((n->m_flags & M_EXT) == 0) {
1339 			goto bad;
1340 		}
1341 	}
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(name, namelen, old)
1421 	const char *name;
1422 	int namelen;
1423 	int old;	/* return pascal string if non-zero */
1424 {
1425 	struct mbuf *m;
1426 	char *cp, *ep;
1427 	const char *p, *q;
1428 	int i, len, nterm;
1429 
1430 	if (old)
1431 		len = namelen + 1;
1432 	else
1433 		len = MCLBYTES;
1434 
1435 	/* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1436 	MGET(m, M_DONTWAIT, MT_DATA);
1437 	if (m && len > MLEN) {
1438 		MCLGET(m, M_DONTWAIT);
1439 		if ((m->m_flags & M_EXT) == 0)
1440 			goto fail;
1441 	}
1442 	if (!m)
1443 		goto fail;
1444 	m->m_next = NULL;
1445 
1446 	if (old) {
1447 		m->m_len = len;
1448 		*mtod(m, char *) = namelen;
1449 		bcopy(name, mtod(m, char *) + 1, namelen);
1450 		return m;
1451 	} else {
1452 		m->m_len = 0;
1453 		cp = mtod(m, char *);
1454 		ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1455 
1456 		/* if not certain about my name, return empty buffer */
1457 		if (namelen == 0)
1458 			return m;
1459 
1460 		/*
1461 		 * guess if it looks like shortened hostname, or FQDN.
1462 		 * shortened hostname needs two trailing "\0".
1463 		 */
1464 		i = 0;
1465 		for (p = name; p < name + namelen; p++) {
1466 			if (*p && *p == '.')
1467 				i++;
1468 		}
1469 		if (i < 2)
1470 			nterm = 2;
1471 		else
1472 			nterm = 1;
1473 
1474 		p = name;
1475 		while (cp < ep && p < name + namelen) {
1476 			i = 0;
1477 			for (q = p; q < name + namelen && *q && *q != '.'; q++)
1478 				i++;
1479 			/* result does not fit into mbuf */
1480 			if (cp + i + 1 >= ep)
1481 				goto fail;
1482 			/* DNS label length restriction, RFC1035 page 8 */
1483 			if (i >= 64)
1484 				goto fail;
1485 			*cp++ = i;
1486 			bcopy(p, cp, i);
1487 			cp += i;
1488 			p = q;
1489 			if (p < name + namelen && *p == '.')
1490 				p++;
1491 		}
1492 		/* termination */
1493 		if (cp + nterm >= ep)
1494 			goto fail;
1495 		while (nterm-- > 0)
1496 			*cp++ = '\0';
1497 		m->m_len = cp - mtod(m, char *);
1498 		return m;
1499 	}
1500 
1501 	panic("should not reach here");
1502 	/*NOTREACHED*/
1503 
1504  fail:
1505 	if (m)
1506 		m_freem(m);
1507 	return NULL;
1508 }
1509 
1510 /*
1511  * check if two DNS-encoded string matches.  takes care of truncated
1512  * form (with \0\0 at the end).  no compression support.
1513  * XXX upper/lowercase match (see RFC2065)
1514  */
1515 static int
1516 ni6_dnsmatch(a, alen, b, blen)
1517 	const char *a;
1518 	int alen;
1519 	const char *b;
1520 	int blen;
1521 {
1522 	const char *a0, *b0;
1523 	int l;
1524 
1525 	/* simplest case - need validation? */
1526 	if (alen == blen && bcmp(a, b, alen) == 0)
1527 		return 1;
1528 
1529 	a0 = a;
1530 	b0 = b;
1531 
1532 	/* termination is mandatory */
1533 	if (alen < 2 || blen < 2)
1534 		return 0;
1535 	if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1536 		return 0;
1537 	alen--;
1538 	blen--;
1539 
1540 	while (a - a0 < alen && b - b0 < blen) {
1541 		if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1542 			return 0;
1543 
1544 		if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1545 			return 0;
1546 		/* we don't support compression yet */
1547 		if (a[0] >= 64 || b[0] >= 64)
1548 			return 0;
1549 
1550 		/* truncated case */
1551 		if (a[0] == 0 && a - a0 == alen - 1)
1552 			return 1;
1553 		if (b[0] == 0 && b - b0 == blen - 1)
1554 			return 1;
1555 		if (a[0] == 0 || b[0] == 0)
1556 			return 0;
1557 
1558 		if (a[0] != b[0])
1559 			return 0;
1560 		l = a[0];
1561 		if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1562 			return 0;
1563 		if (bcmp(a + 1, b + 1, l) != 0)
1564 			return 0;
1565 
1566 		a += 1 + l;
1567 		b += 1 + l;
1568 	}
1569 
1570 	if (a - a0 == alen && b - b0 == blen)
1571 		return 1;
1572 	else
1573 		return 0;
1574 }
1575 
1576 /*
1577  * calculate the number of addresses to be returned in the node info reply.
1578  */
1579 static int
1580 ni6_addrs(ni6, m, ifpp, subj)
1581 	struct icmp6_nodeinfo *ni6;
1582 	struct mbuf *m;
1583 	struct ifnet **ifpp;
1584 	char *subj;
1585 {
1586 	register struct ifnet *ifp;
1587 	register struct in6_ifaddr *ifa6;
1588 	register struct ifaddr *ifa;
1589 	struct sockaddr_in6 *subj_ip6 = NULL; /* XXX pedant */
1590 	int addrs = 0, addrsofif, iffound = 0;
1591 	int niflags = ni6->ni_flags;
1592 
1593 	if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1594 		switch(ni6->ni_code) {
1595 		case ICMP6_NI_SUBJ_IPV6:
1596 			if (subj == NULL) /* must be impossible... */
1597 				return(0);
1598 			subj_ip6 = (struct sockaddr_in6 *)subj;
1599 			break;
1600 		default:
1601 			/*
1602 			 * XXX: we only support IPv6 subject address for
1603 			 * this Qtype.
1604 			 */
1605 			return(0);
1606 		}
1607 	}
1608 
1609 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
1610 	{
1611 		addrsofif = 0;
1612 		for (ifa = ifp->if_addrlist.tqh_first; ifa;
1613 		     ifa = ifa->ifa_list.tqe_next)
1614 		{
1615 			if (ifa->ifa_addr->sa_family != AF_INET6)
1616 				continue;
1617 			ifa6 = (struct in6_ifaddr *)ifa;
1618 
1619 			if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1620 			    IN6_ARE_ADDR_EQUAL(&subj_ip6->sin6_addr,
1621 					       &ifa6->ia_addr.sin6_addr))
1622 				iffound = 1;
1623 
1624 			/*
1625 			 * IPv4-mapped addresses can only be returned by a
1626 			 * Node Information proxy, since they represent
1627 			 * addresses of IPv4-only nodes, which perforce do
1628 			 * not implement this protocol.
1629 			 * [icmp-name-lookups-07, Section 5.4]
1630 			 * So we don't support NI_NODEADDR_FLAG_COMPAT in
1631 			 * this function at this moment.
1632 			 */
1633 
1634 			/* What do we have to do about ::1? */
1635 			switch(in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1636 			case IPV6_ADDR_SCOPE_LINKLOCAL:
1637 				if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL)
1638 				    == 0)
1639 					continue;
1640 				break;
1641 			case IPV6_ADDR_SCOPE_SITELOCAL:
1642 				if ((niflags & NI_NODEADDR_FLAG_SITELOCAL)
1643 				    == 0)
1644 					continue;
1645 				break;
1646 			case IPV6_ADDR_SCOPE_GLOBAL:
1647 				if ((niflags & NI_NODEADDR_FLAG_GLOBAL)
1648 				    == 0)
1649 					continue;
1650 				break;
1651 			default:
1652 				continue;
1653 			}
1654 
1655 			/*
1656 			 * check if anycast is okay.
1657 			 * XXX: just experimental. not in the spec.
1658 			 */
1659 			if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1660 			    (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1661 				continue; /* we need only unicast addresses */
1662 
1663 			addrsofif++; /* count the address */
1664 		}
1665 		if (iffound) {
1666 			*ifpp = ifp;
1667 			return(addrsofif);
1668 		}
1669 
1670 		addrs += addrsofif;
1671 	}
1672 
1673 	return(addrs);
1674 }
1675 
1676 static int
1677 ni6_store_addrs(ni6, nni6, ifp0, resid)
1678 	struct icmp6_nodeinfo *ni6, *nni6;
1679 	struct ifnet *ifp0;
1680 	int resid;
1681 {
1682 	register struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet);
1683 	register struct in6_ifaddr *ifa6;
1684 	register struct ifaddr *ifa;
1685 	struct ifnet *ifp_dep = NULL;
1686 	int copied = 0, allow_deprecated = 0;
1687 	u_char *cp = (u_char *)(nni6 + 1);
1688 	int niflags = ni6->ni_flags;
1689 	u_int32_t ltime;
1690 	long time_second = time.tv_sec;
1691 
1692 	if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1693 		return(0);	/* needless to copy */
1694 
1695   again:
1696 
1697 	for (; ifp; ifp = TAILQ_NEXT(ifp, if_list))
1698 	{
1699 		for (ifa = ifp->if_addrlist.tqh_first; ifa;
1700 		     ifa = ifa->ifa_list.tqe_next)
1701 		{
1702 			if (ifa->ifa_addr->sa_family != AF_INET6)
1703 				continue;
1704 			ifa6 = (struct in6_ifaddr *)ifa;
1705 
1706 			if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1707 			    allow_deprecated == 0) {
1708 				/*
1709 				 * prefererred address should be put before
1710 				 * deprecated addresses.
1711 				 */
1712 
1713 				/* record the interface for later search */
1714 				if (ifp_dep == NULL)
1715 					ifp_dep = ifp;
1716 
1717 				continue;
1718 			}
1719 			else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1720 				 allow_deprecated != 0)
1721 				continue; /* we now collect deprecated addrs */
1722 
1723 			/* What do we have to do about ::1? */
1724 			switch(in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1725 			case IPV6_ADDR_SCOPE_LINKLOCAL:
1726 				if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL)
1727 				    == 0)
1728 					continue;
1729 				break;
1730 			case IPV6_ADDR_SCOPE_SITELOCAL:
1731 				if ((niflags & NI_NODEADDR_FLAG_SITELOCAL)
1732 				    == 0)
1733 					continue;
1734 				break;
1735 			case IPV6_ADDR_SCOPE_GLOBAL:
1736 				if ((niflags & NI_NODEADDR_FLAG_GLOBAL)
1737 				    == 0)
1738 					continue;
1739 				break;
1740 			default:
1741 				continue;
1742 			}
1743 
1744 			/*
1745 			 * check if anycast is okay.
1746 			 * XXX: just experimental. not in the spec.
1747 			 */
1748 			if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1749 			    (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1750 				continue;
1751 
1752 			/* now we can copy the address */
1753 			if (resid < sizeof(struct in6_addr) +
1754 			    sizeof(u_int32_t)) {
1755 				/*
1756 				 * We give up much more copy.
1757 				 * Set the truncate flag and return.
1758 				 */
1759 				nni6->ni_flags |=
1760 					NI_NODEADDR_FLAG_TRUNCATE;
1761 				return(copied);
1762 			}
1763 
1764 			/*
1765 			 * Set the TTL of the address.
1766 			 * The TTL value should be one of the following
1767 			 * according to the specification:
1768 			 *
1769 			 * 1. The remaining lifetime of a DHCP lease on the
1770 			 *    address, or
1771 			 * 2. The remaining Valid Lifetime of a prefix from
1772 			 *    which the address was derived through Stateless
1773 			 *    Autoconfiguration.
1774 			 *
1775 			 * Note that we currently do not support stateful
1776 			 * address configuration by DHCPv6, so the former
1777 			 * case can't happen.
1778 			 */
1779 			if (ifa6->ia6_lifetime.ia6t_expire == 0)
1780 				ltime = ND6_INFINITE_LIFETIME;
1781 			else {
1782 				if (ifa6->ia6_lifetime.ia6t_expire >
1783 				    time_second)
1784 					ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second);
1785 				else
1786 					ltime = 0;
1787 			}
1788 
1789 			bcopy(&ltime, cp, sizeof(u_int32_t));
1790 			cp += sizeof(u_int32_t);
1791 
1792 			/* copy the address itself */
1793 			bcopy(&ifa6->ia_addr.sin6_addr, cp,
1794 			      sizeof(struct in6_addr));
1795 			/* XXX: KAME link-local hack; remove ifindex */
1796 			if (IN6_IS_ADDR_LINKLOCAL(&ifa6->ia_addr.sin6_addr))
1797 				((struct in6_addr *)cp)->s6_addr16[1] = 0;
1798 			cp += sizeof(struct in6_addr);
1799 
1800 			resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1801 			copied += (sizeof(struct in6_addr) +
1802 				   sizeof(u_int32_t));
1803 		}
1804 		if (ifp0)	/* we need search only on the specified IF */
1805 			break;
1806 	}
1807 
1808 	if (allow_deprecated == 0 && ifp_dep != NULL) {
1809 		ifp = ifp_dep;
1810 		allow_deprecated = 1;
1811 
1812 		goto again;
1813 	}
1814 
1815 	return(copied);
1816 }
1817 
1818 /*
1819  * XXX almost dup'ed code with rip6_input.
1820  */
1821 static int
1822 icmp6_rip6_input(mp, off)
1823 	struct	mbuf **mp;
1824 	int	off;
1825 {
1826 	struct mbuf *m = *mp;
1827 	register struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1828 	register struct in6pcb *in6p;
1829 	struct in6pcb *last = NULL;
1830 	struct sockaddr_in6 rip6src;
1831 	struct icmp6_hdr *icmp6;
1832 	struct mbuf *opts = NULL;
1833 
1834 #ifndef PULLDOWN_TEST
1835 	/* this is assumed to be safe. */
1836 	icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1837 #else
1838 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1839 	if (icmp6 == NULL) {
1840 		/* m is already reclaimed */
1841 		return IPPROTO_DONE;
1842 	}
1843 #endif
1844 
1845 	bzero(&rip6src, sizeof(rip6src));
1846 	rip6src.sin6_len = sizeof(struct sockaddr_in6);
1847 	rip6src.sin6_family = AF_INET6;
1848 	/* KAME hack: recover scopeid */
1849 	(void)in6_recoverscope(&rip6src, &ip6->ip6_src, m->m_pkthdr.rcvif);
1850 
1851 	for (in6p = rawin6pcb.in6p_next;
1852 	     in6p != &rawin6pcb; in6p = in6p->in6p_next)
1853 	{
1854 		if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6)
1855 			continue;
1856 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1857 		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1858 			continue;
1859 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1860 		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1861 			continue;
1862 		if (in6p->in6p_icmp6filt
1863 		    && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1864 				 in6p->in6p_icmp6filt))
1865 			continue;
1866 		if (last) {
1867 			struct	mbuf *n;
1868 			if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
1869 				if (last->in6p_flags & IN6P_CONTROLOPTS)
1870 					ip6_savecontrol(last, &opts, ip6, n);
1871 				/* strip intermediate headers */
1872 				m_adj(n, off);
1873 				if (sbappendaddr(&last->in6p_socket->so_rcv,
1874 						 (struct sockaddr *)&rip6src,
1875 						 n, opts) == 0) {
1876 					/* should notify about lost packet */
1877 					m_freem(n);
1878 					if (opts)
1879 						m_freem(opts);
1880 				} else
1881 					sorwakeup(last->in6p_socket);
1882 				opts = NULL;
1883 			}
1884 		}
1885 		last = in6p;
1886 	}
1887 	if (last) {
1888 		if (last->in6p_flags & IN6P_CONTROLOPTS)
1889 			ip6_savecontrol(last, &opts, ip6, m);
1890 		/* strip intermediate headers */
1891 		m_adj(m, off);
1892 		if (sbappendaddr(&last->in6p_socket->so_rcv,
1893 				(struct sockaddr *)&rip6src, m, opts) == 0) {
1894 			m_freem(m);
1895 			if (opts)
1896 				m_freem(opts);
1897 		} else
1898 			sorwakeup(last->in6p_socket);
1899 	} else {
1900 		m_freem(m);
1901 		ip6stat.ip6s_delivered--;
1902 	}
1903 	return IPPROTO_DONE;
1904 }
1905 
1906 /*
1907  * Reflect the ip6 packet back to the source.
1908  * OFF points to the icmp6 header, counted from the top of the mbuf.
1909  */
1910 void
1911 icmp6_reflect(m, off)
1912 	struct	mbuf *m;
1913 	size_t off;
1914 {
1915 	struct ip6_hdr *ip6;
1916 	struct icmp6_hdr *icmp6;
1917 	struct in6_ifaddr *ia;
1918 	struct in6_addr t, *src = 0;
1919 	int plen;
1920 	int type, code;
1921 	struct ifnet *outif = NULL;
1922 #ifdef COMPAT_RFC1885
1923 	int mtu = IPV6_MMTU;
1924 	struct sockaddr_in6 *sin6 = &icmp6_reflect_rt.ro_dst;
1925 #endif
1926 
1927 	/* too short to reflect */
1928 	if (off < sizeof(struct ip6_hdr)) {
1929 		printf("sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
1930 		       (u_long)off, (u_long)sizeof(struct ip6_hdr),
1931 		       __FILE__, __LINE__);
1932 		goto bad;
1933 	}
1934 
1935 	/*
1936 	 * If there are extra headers between IPv6 and ICMPv6, strip
1937 	 * off that header first.
1938 	 */
1939 #ifdef DIAGNOSTIC
1940 	if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
1941 		panic("assumption failed in icmp6_reflect");
1942 #endif
1943 	if (off > sizeof(struct ip6_hdr)) {
1944 		size_t l;
1945 		struct ip6_hdr nip6;
1946 
1947 		l = off - sizeof(struct ip6_hdr);
1948 		m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
1949 		m_adj(m, l);
1950 		l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
1951 		if (m->m_len < l) {
1952 			if ((m = m_pullup(m, l)) == NULL)
1953 				return;
1954 		}
1955 		bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
1956 	} else /* off == sizeof(struct ip6_hdr) */ {
1957 		size_t l;
1958 		l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
1959 		if (m->m_len < l) {
1960 			if ((m = m_pullup(m, l)) == NULL)
1961 				return;
1962 		}
1963 	}
1964 	plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
1965 	ip6 = mtod(m, struct ip6_hdr *);
1966 	ip6->ip6_nxt = IPPROTO_ICMPV6;
1967 	icmp6 = (struct icmp6_hdr *)(ip6 + 1);
1968 	type = icmp6->icmp6_type; /* keep type for statistics */
1969 	code = icmp6->icmp6_code; /* ditto. */
1970 
1971 	t = ip6->ip6_dst;
1972 	/*
1973 	 * ip6_input() drops a packet if its src is multicast.
1974 	 * So, the src is never multicast.
1975 	 */
1976 	ip6->ip6_dst = ip6->ip6_src;
1977 
1978 	/* XXX hack for link-local addresses */
1979 	if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
1980 		ip6->ip6_dst.s6_addr16[1] =
1981 			htons(m->m_pkthdr.rcvif->if_index);
1982 	if (IN6_IS_ADDR_LINKLOCAL(&t))
1983 		t.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index);
1984 
1985 #ifdef COMPAT_RFC1885
1986 	/*
1987 	 * xxx guess MTU
1988 	 * RFC 1885 requires that echo reply should be truncated if it
1989 	 * does not fit in with (return) path MTU, but the description was
1990 	 * removed in the new spec.
1991 	 */
1992 	if (icmp6_reflect_rt.ro_rt == 0 ||
1993 	    ! (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &ip6->ip6_dst))) {
1994 		if (icmp6_reflect_rt.ro_rt) {
1995 			icmp6_reflect_rt.ro_rt = 0;
1996 		}
1997 		bzero(sin6, sizeof(*sin6));
1998 		sin6->sin6_family = PF_INET6;
1999 		sin6->sin6_len = sizeof(struct sockaddr_in6);
2000 		sin6->sin6_addr = ip6->ip6_dst;
2001 
2002 		rtalloc((struct route *)&icmp6_reflect_rt.ro_rt);
2003 	}
2004 
2005 	if (icmp6_reflect_rt.ro_rt == 0)
2006 		goto bad;
2007 
2008 	if ((icmp6_reflect_rt.ro_rt->rt_flags & RTF_HOST)
2009 	    && mtu < icmp6_reflect_rt.ro_rt->rt_ifp->if_mtu)
2010 		mtu = icmp6_reflect_rt.ro_rt->rt_rmx.rmx_mtu;
2011 
2012 	if (mtu < m->m_pkthdr.len) {
2013 		plen -= (m->m_pkthdr.len - mtu);
2014 		m_adj(m, mtu - m->m_pkthdr.len);
2015 	}
2016 #endif
2017 	/*
2018 	 * If the incoming packet was addressed directly to us(i.e. unicast),
2019 	 * use dst as the src for the reply.
2020 	 * The IN6_IFF_NOTREADY case would be VERY rare, but is possible
2021 	 * (for example) when we encounter an error while forwarding procedure
2022 	 * destined to a duplicated address of ours.
2023 	 */
2024 	for (ia = in6_ifaddr; ia; ia = ia->ia_next)
2025 		if (IN6_ARE_ADDR_EQUAL(&t, &ia->ia_addr.sin6_addr) &&
2026 		    (ia->ia6_flags & (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) {
2027 			src = &t;
2028 			break;
2029 		}
2030 	if (ia == NULL && IN6_IS_ADDR_LINKLOCAL(&t) && (m->m_flags & M_LOOP)) {
2031 		/*
2032 		 * This is the case if the dst is our link-local address
2033 		 * and the sender is also ourseleves.
2034 		 */
2035 		src = &t;
2036 	}
2037 
2038 	if (src == 0)
2039 		/*
2040 		 * This case matches to multicasts, our anycast, or unicasts
2041 		 * that we do not own. Select a source address which has the
2042 		 * same scope.
2043 		 * XXX: for (non link-local) multicast addresses, this might
2044 		 * not be a good choice.
2045 		 */
2046 		if ((ia = in6_ifawithscope(m->m_pkthdr.rcvif, &t)) != 0)
2047 			src = &IA6_SIN6(ia)->sin6_addr;
2048 
2049 	if (src == 0)
2050 		goto bad;
2051 
2052 	ip6->ip6_src = *src;
2053 
2054 	ip6->ip6_flow = 0;
2055 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2056 	ip6->ip6_vfc |= IPV6_VERSION;
2057 	ip6->ip6_nxt = IPPROTO_ICMPV6;
2058 	if (m->m_pkthdr.rcvif) {
2059 		/* XXX: This may not be the outgoing interface */
2060 		ip6->ip6_hlim = nd_ifinfo[m->m_pkthdr.rcvif->if_index].chlim;
2061 	}
2062 
2063 	icmp6->icmp6_cksum = 0;
2064 	icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2065 					sizeof(struct ip6_hdr), plen);
2066 
2067 	/*
2068 	 * xxx option handling
2069 	 */
2070 
2071 	m->m_flags &= ~(M_BCAST|M_MCAST);
2072 #ifdef IPSEC
2073 	/* Don't lookup socket */
2074 	ipsec_setsocket(m, NULL);
2075 #endif /*IPSEC*/
2076 
2077 #ifdef COMPAT_RFC1885
2078 	ip6_output(m, NULL, &icmp6_reflect_rt, 0, NULL, &outif);
2079 #else
2080 	ip6_output(m, NULL, NULL, 0, NULL, &outif);
2081 #endif
2082 	if (outif)
2083 		icmp6_ifoutstat_inc(outif, type, code);
2084 
2085 	return;
2086 
2087  bad:
2088 	m_freem(m);
2089 	return;
2090 }
2091 
2092 void
2093 icmp6_fasttimo()
2094 {
2095 
2096 	mld6_fasttimeo();
2097 }
2098 
2099 static const char *
2100 icmp6_redirect_diag(src6, dst6, tgt6)
2101 	struct in6_addr *src6;
2102 	struct in6_addr *dst6;
2103 	struct in6_addr *tgt6;
2104 {
2105 	static char buf[1024];
2106 	snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2107 		ip6_sprintf(src6), ip6_sprintf(dst6), ip6_sprintf(tgt6));
2108 	return buf;
2109 }
2110 
2111 void
2112 icmp6_redirect_input(m, off)
2113 	register struct mbuf *m;
2114 	int off;
2115 {
2116 	struct ifnet *ifp = m->m_pkthdr.rcvif;
2117 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2118 	struct nd_redirect *nd_rd;
2119 	int icmp6len = ntohs(ip6->ip6_plen);
2120 	char *lladdr = NULL;
2121 	int lladdrlen = 0;
2122 	u_char *redirhdr = NULL;
2123 	int redirhdrlen = 0;
2124 	struct rtentry *rt = NULL;
2125 	int is_router;
2126 	int is_onlink;
2127 	struct in6_addr src6 = ip6->ip6_src;
2128 	struct in6_addr redtgt6;
2129 	struct in6_addr reddst6;
2130 	union nd_opts ndopts;
2131 
2132 	if (!m || !ifp)
2133 		return;
2134 
2135 	/* XXX if we are router, we don't update route by icmp6 redirect */
2136 	if (ip6_forwarding)
2137 		goto freeit;
2138 	if (!icmp6_rediraccept)
2139 		goto freeit;
2140 
2141 #ifndef PULLDOWN_TEST
2142 	IP6_EXTHDR_CHECK(m, off, icmp6len,);
2143 	nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2144 #else
2145 	IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2146 	if (nd_rd == NULL) {
2147 		icmp6stat.icp6s_tooshort++;
2148 		return;
2149 	}
2150 #endif
2151 	redtgt6 = nd_rd->nd_rd_target;
2152 	reddst6 = nd_rd->nd_rd_dst;
2153 
2154 	if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2155 		redtgt6.s6_addr16[1] = htons(ifp->if_index);
2156 	if (IN6_IS_ADDR_LINKLOCAL(&reddst6))
2157 		reddst6.s6_addr16[1] = htons(ifp->if_index);
2158 
2159 	/* validation */
2160 	if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2161 		log(LOG_ERR,
2162 			"ICMP6 redirect sent from %s rejected; "
2163 			"must be from linklocal\n", ip6_sprintf(&src6));
2164 		goto freeit;
2165 	}
2166 	if (ip6->ip6_hlim != 255) {
2167 		log(LOG_ERR,
2168 			"ICMP6 redirect sent from %s rejected; "
2169 			"hlim=%d (must be 255)\n",
2170 			ip6_sprintf(&src6), ip6->ip6_hlim);
2171 		goto freeit;
2172 	}
2173     {
2174 	/* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2175 	struct sockaddr_in6 sin6;
2176 	struct in6_addr *gw6;
2177 
2178 	bzero(&sin6, sizeof(sin6));
2179 	sin6.sin6_family = AF_INET6;
2180 	sin6.sin6_len = sizeof(struct sockaddr_in6);
2181 	bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
2182 	rt = rtalloc1((struct sockaddr *)&sin6, 0);
2183 	if (rt) {
2184 		if (rt->rt_gateway == NULL ||
2185 		    rt->rt_gateway->sa_family != AF_INET6) {
2186 			log(LOG_ERR,
2187 			    "ICMP6 redirect rejected; no route "
2188 			    "with inet6 gateway found for redirect dst: %s\n",
2189 			    icmp6_redirect_diag(&src6, &reddst6, &redtgt6));
2190 			RTFREE(rt);
2191 			goto freeit;
2192 		}
2193 
2194 		gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2195 		if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2196 			log(LOG_ERR,
2197 				"ICMP6 redirect rejected; "
2198 				"not equal to gw-for-src=%s (must be same): "
2199 				"%s\n",
2200 				ip6_sprintf(gw6),
2201 				icmp6_redirect_diag(&src6, &reddst6, &redtgt6));
2202 			RTFREE(rt);
2203 			goto freeit;
2204 		}
2205 	} else {
2206 		log(LOG_ERR,
2207 			"ICMP6 redirect rejected; "
2208 			"no route found for redirect dst: %s\n",
2209 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6));
2210 		goto freeit;
2211 	}
2212 	RTFREE(rt);
2213 	rt = NULL;
2214     }
2215 	if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2216 		log(LOG_ERR,
2217 			"ICMP6 redirect rejected; "
2218 			"redirect dst must be unicast: %s\n",
2219 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6));
2220 		goto freeit;
2221 	}
2222 
2223 	is_router = is_onlink = 0;
2224 	if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2225 		is_router = 1;	/* router case */
2226 	if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2227 		is_onlink = 1;	/* on-link destination case */
2228 	if (!is_router && !is_onlink) {
2229 		log(LOG_ERR,
2230 			"ICMP6 redirect rejected; "
2231 			"neither router case nor onlink case: %s\n",
2232 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6));
2233 		goto freeit;
2234 	}
2235 	/* validation passed */
2236 
2237 	icmp6len -= sizeof(*nd_rd);
2238 	nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2239 	if (nd6_options(&ndopts) < 0) {
2240 		log(LOG_INFO, "icmp6_redirect_input: "
2241 			"invalid ND option, rejected: %s\n",
2242 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6));
2243 		goto freeit;
2244 	}
2245 
2246 	if (ndopts.nd_opts_tgt_lladdr) {
2247 		lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2248 		lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2249 	}
2250 
2251 	if (ndopts.nd_opts_rh) {
2252 		redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
2253 		redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
2254 	}
2255 
2256 	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2257 		log(LOG_INFO,
2258 			"icmp6_redirect_input: lladdrlen mismatch for %s "
2259 			"(if %d, icmp6 packet %d): %s\n",
2260 			ip6_sprintf(&redtgt6), ifp->if_addrlen, lladdrlen - 2,
2261 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6));
2262 	}
2263 
2264 	/* RFC 2461 8.3 */
2265 	nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2266 			 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2267 
2268 	if (!is_onlink) {	/* better router case. perform rtredirect. */
2269 		/* perform rtredirect */
2270 		struct sockaddr_in6 sdst;
2271 		struct sockaddr_in6 sgw;
2272 		struct sockaddr_in6 ssrc;
2273 
2274 		bzero(&sdst, sizeof(sdst));
2275 		bzero(&sgw, sizeof(sgw));
2276 		bzero(&ssrc, sizeof(ssrc));
2277 		sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2278 		sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2279 			sizeof(struct sockaddr_in6);
2280 		bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2281 		bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2282 		bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2283 		rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2284 			   (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
2285 			   (struct sockaddr *)&ssrc,
2286 			   (struct rtentry **)NULL
2287 			   );
2288 	}
2289 	/* finally update cached route in each socket via pfctlinput */
2290     {
2291 	struct sockaddr_in6 sdst;
2292 #if 1
2293 #else
2294 	struct ip6protosw *pr;
2295 #endif
2296 
2297 	bzero(&sdst, sizeof(sdst));
2298 	sdst.sin6_family = AF_INET6;
2299 	sdst.sin6_len = sizeof(struct sockaddr_in6);
2300 	bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2301 #if 1
2302 	pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2303 #else
2304 	/*
2305 	 * do not use pfctlinput() here, we have different prototype for
2306 	 * xx_ctlinput() in ip6proto.
2307 	 */
2308 	for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
2309 	     pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW;
2310 	     pr++) {
2311 		if (pr->pr_ctlinput) {
2312 			(*pr->pr_ctlinput)(PRC_REDIRECT_HOST,
2313 				(struct sockaddr *)&sdst, NULL, NULL, 0);
2314 		}
2315 	}
2316 #endif
2317 #ifdef IPSEC
2318 	key_sa_routechange((struct sockaddr *)&sdst);
2319 #endif
2320     }
2321 
2322  freeit:
2323 	m_freem(m);
2324 }
2325 
2326 void
2327 icmp6_redirect_output(m0, rt)
2328 	struct mbuf *m0;
2329 	struct rtentry *rt;
2330 {
2331 	struct ifnet *ifp;	/* my outgoing interface */
2332 	struct in6_addr *ifp_ll6;
2333 	struct in6_addr *router_ll6;
2334 	struct ip6_hdr *sip6;	/* m0 as struct ip6_hdr */
2335 	struct mbuf *m = NULL;	/* newly allocated one */
2336 	struct ip6_hdr *ip6;	/* m as struct ip6_hdr */
2337 	struct nd_redirect *nd_rd;
2338 	size_t maxlen;
2339 	u_char *p;
2340 	struct ifnet *outif = NULL;
2341 	struct sockaddr_in6 src_sa;
2342 
2343 	icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
2344 
2345 	/* if we are not router, we don't send icmp6 redirect */
2346 	if (!ip6_forwarding || ip6_accept_rtadv)
2347 		goto fail;
2348 
2349 	/* sanity check */
2350 	if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2351 		goto fail;
2352 
2353 	/*
2354 	 * Address check:
2355 	 *  the source address must identify a neighbor, and
2356 	 *  the destination address must not be a multicast address
2357 	 *  [RFC 2461, sec 8.2]
2358 	 */
2359 	sip6 = mtod(m0, struct ip6_hdr *);
2360 	bzero(&src_sa, sizeof(src_sa));
2361 	src_sa.sin6_family = AF_INET6;
2362 	src_sa.sin6_len = sizeof(src_sa);
2363 	src_sa.sin6_addr = sip6->ip6_src;
2364 	/* we don't currently use sin6_scope_id, but eventually use it */
2365 	src_sa.sin6_scope_id = in6_addr2scopeid(ifp, &sip6->ip6_src);
2366 	if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2367 		goto fail;
2368 	if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2369 		goto fail;	/* what should we do here? */
2370 
2371 	/* rate limit */
2372 	if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2373 		goto fail;
2374 
2375 	/*
2376 	 * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2377 	 * we almost always ask for an mbuf cluster for simplicity.
2378 	 * (MHLEN < IPV6_MMTU is almost always true)
2379 	 */
2380 #if IPV6_MMTU >= MCLBYTES
2381 # error assumption failed about IPV6_MMTU and MCLBYTES
2382 #endif
2383 	MGETHDR(m, M_DONTWAIT, MT_HEADER);
2384 	if (m && IPV6_MMTU >= MHLEN)
2385 		MCLGET(m, M_DONTWAIT);
2386 	if (!m)
2387 		goto fail;
2388 	m->m_len = 0;
2389 	maxlen = M_TRAILINGSPACE(m);
2390 	maxlen = min(IPV6_MMTU, maxlen);
2391 	/* just for safety */
2392 	if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2393 	    ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2394 		goto fail;
2395 	}
2396 
2397 	{
2398 		/* get ip6 linklocal address for ifp(my outgoing interface). */
2399 		struct in6_ifaddr *ia;
2400 		if ((ia = in6ifa_ifpforlinklocal(ifp,
2401 						 IN6_IFF_NOTREADY|
2402 						 IN6_IFF_ANYCAST)) == NULL)
2403 			goto fail;
2404 		ifp_ll6 = &ia->ia_addr.sin6_addr;
2405 	}
2406 
2407 	/* get ip6 linklocal address for the router. */
2408 	if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2409 		struct sockaddr_in6 *sin6;
2410 		sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2411 		router_ll6 = &sin6->sin6_addr;
2412 		if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2413 			router_ll6 = (struct in6_addr *)NULL;
2414 	} else
2415 		router_ll6 = (struct in6_addr *)NULL;
2416 
2417 	/* ip6 */
2418 	ip6 = mtod(m, struct ip6_hdr *);
2419 	ip6->ip6_flow = 0;
2420 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2421 	ip6->ip6_vfc |= IPV6_VERSION;
2422 	/* ip6->ip6_plen will be set later */
2423 	ip6->ip6_nxt = IPPROTO_ICMPV6;
2424 	ip6->ip6_hlim = 255;
2425 	/* ip6->ip6_src must be linklocal addr for my outgoing if. */
2426 	bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2427 	bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2428 
2429 	/* ND Redirect */
2430 	nd_rd = (struct nd_redirect *)(ip6 + 1);
2431 	nd_rd->nd_rd_type = ND_REDIRECT;
2432 	nd_rd->nd_rd_code = 0;
2433 	nd_rd->nd_rd_reserved = 0;
2434 	if (rt->rt_flags & RTF_GATEWAY) {
2435 		/*
2436 		 * nd_rd->nd_rd_target must be a link-local address in
2437 		 * better router cases.
2438 		 */
2439 		if (!router_ll6)
2440 			goto fail;
2441 		bcopy(router_ll6, &nd_rd->nd_rd_target,
2442 		      sizeof(nd_rd->nd_rd_target));
2443 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2444 		      sizeof(nd_rd->nd_rd_dst));
2445 	} else {
2446 		/* make sure redtgt == reddst */
2447 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2448 		      sizeof(nd_rd->nd_rd_target));
2449 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2450 		      sizeof(nd_rd->nd_rd_dst));
2451 	}
2452 
2453 	p = (u_char *)(nd_rd + 1);
2454 
2455 	if (!router_ll6)
2456 		goto nolladdropt;
2457 
2458     {
2459 	/* target lladdr option */
2460 	struct rtentry *rt_router = NULL;
2461 	int len;
2462 	struct sockaddr_dl *sdl;
2463 	struct nd_opt_hdr *nd_opt;
2464 	char *lladdr;
2465 
2466 	rt_router = nd6_lookup(router_ll6, 0, ifp);
2467 	if (!rt_router)
2468 		goto nolladdropt;
2469 	len = sizeof(*nd_opt) + ifp->if_addrlen;
2470 	len = (len + 7) & ~7;	/*round by 8*/
2471 	/* safety check */
2472 	if (len + (p - (u_char *)ip6) > maxlen)
2473 		goto nolladdropt;
2474 	if (!(rt_router->rt_flags & RTF_GATEWAY) &&
2475 	    (rt_router->rt_flags & RTF_LLINFO) &&
2476 	    (rt_router->rt_gateway->sa_family == AF_LINK) &&
2477 	    (sdl = (struct sockaddr_dl *)rt_router->rt_gateway) &&
2478 	    sdl->sdl_alen) {
2479 		nd_opt = (struct nd_opt_hdr *)p;
2480 		nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2481 		nd_opt->nd_opt_len = len >> 3;
2482 		lladdr = (char *)(nd_opt + 1);
2483 		bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen);
2484 		p += len;
2485 	}
2486     }
2487 nolladdropt:;
2488 
2489 	m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2490 
2491 	/* just to be safe */
2492 	if (m0->m_flags & M_DECRYPTED)
2493 		goto noredhdropt;
2494 	if (p - (u_char *)ip6 > maxlen)
2495 		goto noredhdropt;
2496 
2497     {
2498 	/* redirected header option */
2499 	int len;
2500 	struct nd_opt_rd_hdr *nd_opt_rh;
2501 
2502 	/*
2503 	 * compute the maximum size for icmp6 redirect header option.
2504 	 * XXX room for auth header?
2505 	 */
2506 	len = maxlen - (p - (u_char *)ip6);
2507 	len &= ~7;
2508 
2509 	/* This is just for simplicity. */
2510 	if (m0->m_pkthdr.len != m0->m_len) {
2511 		if (m0->m_next) {
2512 			m_freem(m0->m_next);
2513 			m0->m_next = NULL;
2514 		}
2515 		m0->m_pkthdr.len = m0->m_len;
2516 	}
2517 
2518 	/*
2519 	 * Redirected header option spec (RFC2461 4.6.3) talks nothing
2520 	 * about padding/truncate rule for the original IP packet.
2521 	 * From the discussion on IPv6imp in Feb 1999, the consensus was:
2522 	 * - "attach as much as possible" is the goal
2523 	 * - pad if not aligned (original size can be guessed by original
2524 	 *   ip6 header)
2525 	 * Following code adds the padding if it is simple enough,
2526 	 * and truncates if not.
2527 	 */
2528 	if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2529 		panic("assumption failed in %s:%d\n", __FILE__, __LINE__);
2530 
2531 	if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2532 		/* not enough room, truncate */
2533 		m0->m_pkthdr.len = m0->m_len = len - sizeof(*nd_opt_rh);
2534 	} else {
2535 		/* enough room, pad or truncate */
2536 		size_t extra;
2537 
2538 		extra = m0->m_pkthdr.len % 8;
2539 		if (extra) {
2540 			/* pad if easy enough, truncate if not */
2541 			if (8 - extra <= M_TRAILINGSPACE(m0)) {
2542 				/* pad */
2543 				m0->m_len += (8 - extra);
2544 				m0->m_pkthdr.len += (8 - extra);
2545 			} else {
2546 				/* truncate */
2547 				m0->m_pkthdr.len -= extra;
2548 				m0->m_len -= extra;
2549 			}
2550 		}
2551 		len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2552 		m0->m_pkthdr.len = m0->m_len = len - sizeof(*nd_opt_rh);
2553 	}
2554 
2555 	nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2556 	bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2557 	nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2558 	nd_opt_rh->nd_opt_rh_len = len >> 3;
2559 	p += sizeof(*nd_opt_rh);
2560 	m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2561 
2562 	/* connect m0 to m */
2563 	m->m_next = m0;
2564 	m->m_pkthdr.len = m->m_len + m0->m_len;
2565     }
2566 noredhdropt:;
2567 
2568 	if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_src))
2569 		sip6->ip6_src.s6_addr16[1] = 0;
2570 	if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_dst))
2571 		sip6->ip6_dst.s6_addr16[1] = 0;
2572 #if 0
2573 	if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
2574 		ip6->ip6_src.s6_addr16[1] = 0;
2575 	if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
2576 		ip6->ip6_dst.s6_addr16[1] = 0;
2577 #endif
2578 	if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_target))
2579 		nd_rd->nd_rd_target.s6_addr16[1] = 0;
2580 	if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_dst))
2581 		nd_rd->nd_rd_dst.s6_addr16[1] = 0;
2582 
2583 	ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2584 
2585 	nd_rd->nd_rd_cksum = 0;
2586 	nd_rd->nd_rd_cksum
2587 		= in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), ntohs(ip6->ip6_plen));
2588 
2589 	/* send the packet to outside... */
2590 #ifdef IPSEC
2591 	/* Don't lookup socket */
2592 	ipsec_setsocket(m, NULL);
2593 #endif /*IPSEC*/
2594 	ip6_output(m, NULL, NULL, 0, NULL, &outif);
2595 	if (outif) {
2596 		icmp6_ifstat_inc(outif, ifs6_out_msg);
2597 		icmp6_ifstat_inc(outif, ifs6_out_redirect);
2598 	}
2599 	icmp6stat.icp6s_outhist[ND_REDIRECT]++;
2600 
2601 	return;
2602 
2603 fail:
2604 	if (m)
2605 		m_freem(m);
2606 	if (m0)
2607 		m_freem(m0);
2608 }
2609 
2610 /*
2611  * ICMPv6 socket option processing.
2612  */
2613 int
2614 icmp6_ctloutput(op, so, level, optname, mp)
2615 	int op;
2616 	struct socket *so;
2617 	int level, optname;
2618 	struct mbuf **mp;
2619 {
2620 	register struct in6pcb *in6p = sotoin6pcb(so);
2621 	register struct mbuf *m = *mp;
2622 	int error = 0;
2623 
2624 	if (level != IPPROTO_ICMPV6) {
2625 		error = EINVAL;
2626 		if (op == PRCO_SETOPT && m)
2627 			(void)m_free(m);
2628 	} else switch(op) {
2629 	 case PRCO_SETOPT:
2630 		 switch (optname) {
2631 		  case ICMP6_FILTER:
2632 		  {
2633 			  struct icmp6_filter *p;
2634 
2635 			  p = mtod(m, struct icmp6_filter *);
2636 			  if (!p || !in6p->in6p_icmp6filt) {
2637 				  error = EINVAL;
2638 				  break;
2639 			  }
2640 			  bcopy(p, in6p->in6p_icmp6filt,
2641 				sizeof(struct icmp6_filter));
2642 			  error = 0;
2643 			  break;
2644 		  }
2645 
2646 		  default:
2647 			  error = ENOPROTOOPT;
2648 			  break;
2649 		 }
2650 		 if (m)
2651 			 (void)m_free(m);
2652 		 break;
2653 
2654 	 case PRCO_GETOPT:
2655 		 switch (optname) {
2656 		  case ICMP6_FILTER:
2657 		  {
2658 			  struct icmp6_filter *p;
2659 
2660 			  if (!in6p->in6p_icmp6filt) {
2661 				  error = EINVAL;
2662 				  break;
2663 			  }
2664 			  *mp = m = m_get(M_WAIT, MT_SOOPTS);
2665 			  m->m_len = sizeof(struct icmp6_filter);
2666 			  p = mtod(m, struct icmp6_filter *);
2667 			  bcopy(in6p->in6p_icmp6filt, p,
2668 				sizeof(struct icmp6_filter));
2669 			  error = 0;
2670 			  break;
2671 		  }
2672 
2673 		  default:
2674 			  error = ENOPROTOOPT;
2675 			  break;
2676 		 }
2677 		 break;
2678 	}
2679 
2680 	return(error);
2681 }
2682 
2683 /*
2684  * Perform rate limit check.
2685  * Returns 0 if it is okay to send the icmp6 packet.
2686  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2687  * limitation.
2688  *
2689  * XXX per-destination/type check necessary?
2690  */
2691 static int
2692 icmp6_ratelimit(dst, type, code)
2693 	const struct in6_addr *dst;	/* not used at this moment */
2694 	const int type;			/* not used at this moment */
2695 	const int code;			/* not used at this moment */
2696 {
2697 	int ret;
2698 
2699 	ret = 0;	/*okay to send*/
2700 
2701 	/* PPS limit */
2702 	if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count,
2703 	    icmp6errppslim)) {
2704 		/* The packet is subject to rate limit */
2705 		ret++;
2706 	}
2707 
2708 	return ret;
2709 }
2710 
2711 static struct rtentry *
2712 icmp6_mtudisc_clone(dst)
2713 	struct sockaddr *dst;
2714 {
2715 	struct rtentry *rt;
2716 	int    error;
2717 
2718 	rt = rtalloc1(dst, 1);
2719 	if (rt == 0)
2720 		return NULL;
2721 
2722 	/* If we didn't get a host route, allocate one */
2723 	if ((rt->rt_flags & RTF_HOST) == 0) {
2724 		struct rtentry *nrt;
2725 
2726 		error = rtrequest((int) RTM_ADD, dst,
2727 		    (struct sockaddr *) rt->rt_gateway,
2728 		    (struct sockaddr *) 0,
2729 		    RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt);
2730 		if (error) {
2731 			rtfree(rt);
2732 			rtfree(nrt);
2733 			return NULL;
2734 		}
2735 		nrt->rt_rmx = rt->rt_rmx;
2736 		rtfree(rt);
2737 		rt = nrt;
2738 	}
2739 	error = rt_timer_add(rt, icmp6_mtudisc_timeout,
2740 			icmp6_mtudisc_timeout_q);
2741 	if (error) {
2742 		rtfree(rt);
2743 		return NULL;
2744 	}
2745 
2746 	return rt;	/* caller need to call rtfree() */
2747 }
2748 
2749 static void
2750 icmp6_mtudisc_timeout(rt, r)
2751 	struct rtentry *rt;
2752 	struct rttimer *r;
2753 {
2754 	if (rt == NULL)
2755 		panic("icmp6_mtudisc_timeout: bad route to timeout");
2756 	if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) ==
2757 	    (RTF_DYNAMIC | RTF_HOST)) {
2758 		rtrequest((int) RTM_DELETE, (struct sockaddr *)rt_key(rt),
2759 		    rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0);
2760 	} else {
2761 		if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) {
2762 			rt->rt_rmx.rmx_mtu = 0;
2763 		}
2764 	}
2765 }
2766 
2767 #include <uvm/uvm_extern.h>
2768 #include <sys/sysctl.h>
2769 
2770 int
2771 icmp6_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
2772 	int *name;
2773 	u_int namelen;
2774 	void *oldp;
2775 	size_t *oldlenp;
2776 	void *newp;
2777 	size_t newlen;
2778 {
2779 
2780 	/* All sysctl names at this level are terminal. */
2781 	if (namelen != 1)
2782 		return ENOTDIR;
2783 
2784 	switch (name[0]) {
2785 
2786 	case ICMPV6CTL_REDIRACCEPT:
2787 		return sysctl_int(oldp, oldlenp, newp, newlen,
2788 				&icmp6_rediraccept);
2789 	case ICMPV6CTL_REDIRTIMEOUT:
2790 		return sysctl_int(oldp, oldlenp, newp, newlen,
2791 				&icmp6_redirtimeout);
2792 	case ICMPV6CTL_STATS:
2793 		return sysctl_rdstruct(oldp, oldlenp, newp,
2794 				&icmp6stat, sizeof(icmp6stat));
2795 	case ICMPV6CTL_ND6_PRUNE:
2796 		return sysctl_int(oldp, oldlenp, newp, newlen, &nd6_prune);
2797 	case ICMPV6CTL_ND6_DELAY:
2798 		return sysctl_int(oldp, oldlenp, newp, newlen, &nd6_delay);
2799 	case ICMPV6CTL_ND6_UMAXTRIES:
2800 		return sysctl_int(oldp, oldlenp, newp, newlen, &nd6_umaxtries);
2801 	case ICMPV6CTL_ND6_MMAXTRIES:
2802 		return sysctl_int(oldp, oldlenp, newp, newlen, &nd6_mmaxtries);
2803 	case ICMPV6CTL_ND6_USELOOPBACK:
2804 		return sysctl_int(oldp, oldlenp, newp, newlen,
2805 				&nd6_useloopback);
2806 	case ICMPV6CTL_NODEINFO:
2807 		return sysctl_int(oldp, oldlenp, newp, newlen, &icmp6_nodeinfo);
2808 	case ICMPV6CTL_ERRPPSLIMIT:
2809 		return sysctl_int(oldp, oldlenp, newp, newlen, &icmp6errppslim);
2810 	case ICMPV6CTL_ND6_MAXNUDHINT:
2811 		return sysctl_int(oldp, oldlenp, newp, newlen,
2812 				&nd6_maxnudhint);
2813 	case ICMPV6CTL_MTUDISC_HIWAT:
2814 		return sysctl_int(oldp, oldlenp, newp, newlen,
2815 				&icmp6_mtudisc_hiwat);
2816 	case ICMPV6CTL_MTUDISC_LOWAT:
2817 		return sysctl_int(oldp, oldlenp, newp, newlen,
2818 				&icmp6_mtudisc_lowat);
2819 	default:
2820 		return ENOPROTOOPT;
2821 	}
2822 	/* NOTREACHED */
2823 }
2824