xref: /freebsd/sys/netinet6/icmp6.c (revision 42c159fe388a3765f69860c84183700af37aca8a)
1 /*	$FreeBSD$	*/
2 /*	$KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 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_inet6.h"
70 #include "opt_ipsec.h"
71 
72 #include <sys/param.h>
73 #include <sys/systm.h>
74 #include <sys/malloc.h>
75 #include <sys/mbuf.h>
76 #include <sys/protosw.h>
77 #include <sys/socket.h>
78 #include <sys/socketvar.h>
79 #include <sys/time.h>
80 #include <sys/kernel.h>
81 #include <sys/syslog.h>
82 #include <sys/domain.h>
83 
84 #include <net/if.h>
85 #include <net/route.h>
86 #include <net/if_dl.h>
87 #include <net/if_types.h>
88 
89 #include <netinet/in.h>
90 #include <netinet/in_var.h>
91 #include <netinet/ip6.h>
92 #include <netinet6/ip6_var.h>
93 #include <netinet/icmp6.h>
94 #include <netinet6/mld6_var.h>
95 #include <netinet/in_pcb.h>
96 #include <netinet6/in6_pcb.h>
97 #include <netinet6/nd6.h>
98 #include <netinet6/in6_ifattach.h>
99 #include <netinet6/ip6protosw.h>
100 
101 #ifdef IPSEC
102 #include <netinet6/ipsec.h>
103 #include <netkey/key.h>
104 #endif
105 
106 #include <net/net_osdep.h>
107 
108 #ifdef HAVE_NRL_INPCB
109 /* inpcb members */
110 #define in6pcb		inpcb
111 #define in6p_laddr	inp_laddr6
112 #define in6p_faddr	inp_faddr6
113 #define in6p_icmp6filt	inp_icmp6filt
114 #define in6p_route	inp_route
115 #define in6p_socket	inp_socket
116 #define in6p_flags	inp_flags
117 #define in6p_moptions	inp_moptions6
118 #define in6p_outputopts	inp_outputopts6
119 #define in6p_ip6	inp_ipv6
120 #define in6p_flowinfo	inp_flowinfo
121 #define in6p_sp		inp_sp
122 #define in6p_next	inp_next
123 #define in6p_prev	inp_prev
124 /* macro names */
125 #define sotoin6pcb	sotoinpcb
126 /* function names */
127 #define in6_pcbdetach	in_pcbdetach
128 #define in6_rtchange	in_rtchange
129 
130 /*
131  * for KAME src sync over BSD*'s. XXX: FreeBSD (>=3) are VERY different from
132  * others...
133  */
134 #define in6p_ip6_nxt	inp_ipv6.ip6_nxt
135 #endif
136 
137 extern struct domain inet6domain;
138 
139 struct icmp6stat icmp6stat;
140 
141 extern struct inpcbhead ripcb;
142 extern int icmp6errppslim;
143 static int icmp6errpps_count = 0;
144 static struct timeval icmp6errppslim_last;
145 extern int icmp6_nodeinfo;
146 
147 static void icmp6_errcount __P((struct icmp6errstat *, int, int));
148 static int icmp6_rip6_input __P((struct mbuf **, int));
149 static int icmp6_ratelimit __P((const struct in6_addr *, const int, const int));
150 static const char *icmp6_redirect_diag __P((struct in6_addr *,
151 	struct in6_addr *, struct in6_addr *));
152 #ifndef HAVE_PPSRATECHECK
153 static int ppsratecheck __P((struct timeval *, int *, int));
154 #endif
155 static struct mbuf *ni6_input __P((struct mbuf *, int));
156 static struct mbuf *ni6_nametodns __P((const char *, int, int));
157 static int ni6_dnsmatch __P((const char *, int, const char *, int));
158 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *,
159 			  struct ifnet **, char *));
160 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
161 				struct ifnet *, int));
162 static int icmp6_notify_error __P((struct mbuf *, int, int, int));
163 
164 #ifdef COMPAT_RFC1885
165 static struct route_in6 icmp6_reflect_rt;
166 #endif
167 
168 
169 void
170 icmp6_init()
171 {
172 	mld6_init();
173 }
174 
175 static void
176 icmp6_errcount(stat, type, code)
177 	struct icmp6errstat *stat;
178 	int type, code;
179 {
180 	switch (type) {
181 	case ICMP6_DST_UNREACH:
182 		switch (code) {
183 		case ICMP6_DST_UNREACH_NOROUTE:
184 			stat->icp6errs_dst_unreach_noroute++;
185 			return;
186 		case ICMP6_DST_UNREACH_ADMIN:
187 			stat->icp6errs_dst_unreach_admin++;
188 			return;
189 		case ICMP6_DST_UNREACH_BEYONDSCOPE:
190 			stat->icp6errs_dst_unreach_beyondscope++;
191 			return;
192 		case ICMP6_DST_UNREACH_ADDR:
193 			stat->icp6errs_dst_unreach_addr++;
194 			return;
195 		case ICMP6_DST_UNREACH_NOPORT:
196 			stat->icp6errs_dst_unreach_noport++;
197 			return;
198 		}
199 		break;
200 	case ICMP6_PACKET_TOO_BIG:
201 		stat->icp6errs_packet_too_big++;
202 		return;
203 	case ICMP6_TIME_EXCEEDED:
204 		switch (code) {
205 		case ICMP6_TIME_EXCEED_TRANSIT:
206 			stat->icp6errs_time_exceed_transit++;
207 			return;
208 		case ICMP6_TIME_EXCEED_REASSEMBLY:
209 			stat->icp6errs_time_exceed_reassembly++;
210 			return;
211 		}
212 		break;
213 	case ICMP6_PARAM_PROB:
214 		switch (code) {
215 		case ICMP6_PARAMPROB_HEADER:
216 			stat->icp6errs_paramprob_header++;
217 			return;
218 		case ICMP6_PARAMPROB_NEXTHEADER:
219 			stat->icp6errs_paramprob_nextheader++;
220 			return;
221 		case ICMP6_PARAMPROB_OPTION:
222 			stat->icp6errs_paramprob_option++;
223 			return;
224 		}
225 		break;
226 	case ND_REDIRECT:
227 		stat->icp6errs_redirect++;
228 		return;
229 	}
230 	stat->icp6errs_unknown++;
231 }
232 
233 /*
234  * Generate an error packet of type error in response to bad IP6 packet.
235  */
236 void
237 icmp6_error(m, type, code, param)
238 	struct mbuf *m;
239 	int type, code, param;
240 {
241 	struct ip6_hdr *oip6, *nip6;
242 	struct icmp6_hdr *icmp6;
243 	u_int preplen;
244 	int off;
245 	int nxt;
246 
247 	icmp6stat.icp6s_error++;
248 
249 	/* count per-type-code statistics */
250 	icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code);
251 
252 #ifdef M_DECRYPTED	/*not openbsd*/
253 	if (m->m_flags & M_DECRYPTED) {
254 		icmp6stat.icp6s_canterror++;
255 		goto freeit;
256 	}
257 #endif
258 
259 #ifndef PULLDOWN_TEST
260 	IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
261 #else
262 	if (m->m_len < sizeof(struct ip6_hdr)) {
263 		m = m_pullup(m, sizeof(struct ip6_hdr));
264 		if (m == NULL)
265 			return;
266 	}
267 #endif
268 	oip6 = mtod(m, struct ip6_hdr *);
269 
270 	/*
271 	 * Multicast destination check. For unrecognized option errors,
272 	 * this check has already done in ip6_unknown_opt(), so we can
273 	 * check only for other errors.
274 	 */
275 	if ((m->m_flags & (M_BCAST|M_MCAST) ||
276 	     IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
277 	    (type != ICMP6_PACKET_TOO_BIG &&
278 	     (type != ICMP6_PARAM_PROB ||
279 	      code != ICMP6_PARAMPROB_OPTION)))
280 		goto freeit;
281 
282 	/* Source address check. XXX: the case of anycast source? */
283 	if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
284 	    IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
285 		goto freeit;
286 
287 	/*
288 	 * If we are about to send ICMPv6 against ICMPv6 error/redirect,
289 	 * don't do it.
290 	 */
291 	nxt = -1;
292 	off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
293 	if (off >= 0 && nxt == IPPROTO_ICMPV6) {
294 		struct icmp6_hdr *icp;
295 
296 #ifndef PULLDOWN_TEST
297 		IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
298 		icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
299 #else
300 		IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
301 			sizeof(*icp));
302 		if (icp == NULL) {
303 			icmp6stat.icp6s_tooshort++;
304 			return;
305 		}
306 #endif
307 		if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
308 		    icp->icmp6_type == ND_REDIRECT) {
309 			/*
310 			 * ICMPv6 error
311 			 * Special case: for redirect (which is
312 			 * informational) we must not send icmp6 error.
313 			 */
314 			icmp6stat.icp6s_canterror++;
315 			goto freeit;
316 		} else {
317 			/* ICMPv6 informational - send the error */
318 		}
319 	} else {
320 		/* non-ICMPv6 - send the error */
321 	}
322 
323 	oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
324 
325 	/* Finally, do rate limitation check. */
326 	if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
327 		icmp6stat.icp6s_toofreq++;
328 		goto freeit;
329 	}
330 
331 	/*
332 	 * OK, ICMP6 can be generated.
333 	 */
334 
335 	if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
336 		m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
337 
338 	preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
339 	M_PREPEND(m, preplen, M_DONTWAIT);
340 	if (m && m->m_len < preplen)
341 		m = m_pullup(m, preplen);
342 	if (m == NULL) {
343 		nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
344 		return;
345 	}
346 
347 	nip6 = mtod(m, struct ip6_hdr *);
348 	nip6->ip6_src  = oip6->ip6_src;
349 	nip6->ip6_dst  = oip6->ip6_dst;
350 
351 	if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
352 		oip6->ip6_src.s6_addr16[1] = 0;
353 	if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
354 		oip6->ip6_dst.s6_addr16[1] = 0;
355 
356 	icmp6 = (struct icmp6_hdr *)(nip6 + 1);
357 	icmp6->icmp6_type = type;
358 	icmp6->icmp6_code = code;
359 	icmp6->icmp6_pptr = htonl((u_int32_t)param);
360 
361 	/*
362 	 * icmp6_reflect() is designed to be in the input path.
363 	 * icmp6_error() can be called from both input and outut path,
364 	 * and if we are in output path rcvif could contain bogus value.
365 	 * clear m->m_pkthdr.rcvif for safety, we should have enough scope
366 	 * information in ip header (nip6).
367 	 */
368 	m->m_pkthdr.rcvif = NULL;
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 
397 #ifndef PULLDOWN_TEST
398 	IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
399 	/* m might change if M_LOOP. So, call mtod after this */
400 #endif
401 
402 	/*
403 	 * Locate icmp6 structure in mbuf, and check
404 	 * that not corrupted and of at least minimum length
405 	 */
406 
407 	ip6 = mtod(m, struct ip6_hdr *);
408 	if (icmp6len < sizeof(struct icmp6_hdr)) {
409 		icmp6stat.icp6s_tooshort++;
410 		goto freeit;
411 	}
412 
413 	/*
414 	 * calculate the checksum
415 	 */
416 #ifndef PULLDOWN_TEST
417 	icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
418 #else
419 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
420 	if (icmp6 == NULL) {
421 		icmp6stat.icp6s_tooshort++;
422 		return IPPROTO_DONE;
423 	}
424 #endif
425 	code = icmp6->icmp6_code;
426 
427 	if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
428 		nd6log((LOG_ERR,
429 		    "ICMP6 checksum error(%d|%x) %s\n",
430 		    icmp6->icmp6_type, sum, ip6_sprintf(&ip6->ip6_src)));
431 		icmp6stat.icp6s_checksum++;
432 		goto freeit;
433 	}
434 
435 	if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
436 		/*
437 		 * Deliver very specific ICMP6 type only.
438 		 * This is important to deilver TOOBIG.  Otherwise PMTUD
439 		 * will not work.
440 		 */
441 		switch (icmp6->icmp6_type) {
442 		case ICMP6_DST_UNREACH:
443 		case ICMP6_PACKET_TOO_BIG:
444 		case ICMP6_TIME_EXCEEDED:
445 			break;
446 		default:
447 			goto freeit;
448 		}
449 	}
450 
451 	icmp6stat.icp6s_inhist[icmp6->icmp6_type]++;
452 	icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg);
453 	if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
454 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
455 
456 	switch (icmp6->icmp6_type) {
457 	case ICMP6_DST_UNREACH:
458 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach);
459 		switch (code) {
460 		case ICMP6_DST_UNREACH_NOROUTE:
461 			code = PRC_UNREACH_NET;
462 			break;
463 		case ICMP6_DST_UNREACH_ADMIN:
464 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib);
465 			code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
466 			break;
467 		case ICMP6_DST_UNREACH_ADDR:
468 			code = PRC_HOSTDEAD;
469 			break;
470 #ifdef COMPAT_RFC1885
471 		case ICMP6_DST_UNREACH_NOTNEIGHBOR:
472 			code = PRC_UNREACH_SRCFAIL;
473 			break;
474 #else
475 		case ICMP6_DST_UNREACH_BEYONDSCOPE:
476 			/* I mean "source address was incorrect." */
477 			code = PRC_PARAMPROB;
478 			break;
479 #endif
480 		case ICMP6_DST_UNREACH_NOPORT:
481 			code = PRC_UNREACH_PORT;
482 			break;
483 		default:
484 			goto badcode;
485 		}
486 		goto deliver;
487 		break;
488 
489 	case ICMP6_PACKET_TOO_BIG:
490 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig);
491 		if (code != 0)
492 			goto badcode;
493 
494 		code = PRC_MSGSIZE;
495 
496 		/*
497 		 * Updating the path MTU will be done after examining
498 		 * intermediate extension headers.
499 		 */
500 		goto deliver;
501 		break;
502 
503 	case ICMP6_TIME_EXCEEDED:
504 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed);
505 		switch (code) {
506 		case ICMP6_TIME_EXCEED_TRANSIT:
507 		case ICMP6_TIME_EXCEED_REASSEMBLY:
508 			code += PRC_TIMXCEED_INTRANS;
509 			break;
510 		default:
511 			goto badcode;
512 		}
513 		goto deliver;
514 		break;
515 
516 	case ICMP6_PARAM_PROB:
517 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob);
518 		switch (code) {
519 		case ICMP6_PARAMPROB_NEXTHEADER:
520 			code = PRC_UNREACH_PROTOCOL;
521 			break;
522 		case ICMP6_PARAMPROB_HEADER:
523 		case ICMP6_PARAMPROB_OPTION:
524 			code = PRC_PARAMPROB;
525 			break;
526 		default:
527 			goto badcode;
528 		}
529 		goto deliver;
530 		break;
531 
532 	case ICMP6_ECHO_REQUEST:
533 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo);
534 		if (code != 0)
535 			goto badcode;
536 		if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
537 			/* Give up remote */
538 			break;
539 		}
540 		if ((n->m_flags & M_EXT) != 0
541 		 || n->m_len < off + sizeof(struct icmp6_hdr)) {
542 			struct mbuf *n0 = n;
543 			const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
544 
545 			/*
546 			 * Prepare an internal mbuf. m_pullup() doesn't
547 			 * always copy the length we specified.
548 			 */
549 			if (maxlen >= MCLBYTES) {
550 				/* Give up remote */
551 				m_freem(n0);
552 				break;
553 			}
554 			MGETHDR(n, M_DONTWAIT, n0->m_type);
555 			if (n && maxlen >= MHLEN) {
556 				MCLGET(n, M_DONTWAIT);
557 				if ((n->m_flags & M_EXT) == 0) {
558 					m_free(n);
559 					n = NULL;
560 				}
561 			}
562 			if (n == NULL) {
563 				/* Give up remote */
564 				m_freem(n0);
565 				break;
566 			}
567 			M_COPY_PKTHDR(n, n0);
568 			/*
569 			 * Copy IPv6 and ICMPv6 only.
570 			 */
571 			nip6 = mtod(n, struct ip6_hdr *);
572 			bcopy(ip6, nip6, sizeof(struct ip6_hdr));
573 			nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
574 			bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
575 			noff = sizeof(struct ip6_hdr);
576 			n->m_pkthdr.len = n->m_len =
577 				noff + sizeof(struct icmp6_hdr);
578 			/*
579 			 * Adjust mbuf. ip6_plen will be adjusted in
580 			 * ip6_output().
581 			 */
582 			m_adj(n0, off + sizeof(struct icmp6_hdr));
583 			n->m_pkthdr.len += n0->m_pkthdr.len;
584 			n->m_next = n0;
585 			n0->m_flags &= ~M_PKTHDR;
586 		} else {
587 			nip6 = mtod(n, struct ip6_hdr *);
588 			nicmp6 = (struct icmp6_hdr *)((caddr_t)nip6 + off);
589 			noff = off;
590 		}
591 		nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
592 		nicmp6->icmp6_code = 0;
593 		if (n) {
594 			icmp6stat.icp6s_reflect++;
595 			icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++;
596 			icmp6_reflect(n, noff);
597 		}
598 		break;
599 
600 	case ICMP6_ECHO_REPLY:
601 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply);
602 		if (code != 0)
603 			goto badcode;
604 		break;
605 
606 	case MLD6_LISTENER_QUERY:
607 	case MLD6_LISTENER_REPORT:
608 		if (icmp6len < sizeof(struct mld6_hdr))
609 			goto badlen;
610 		if (icmp6->icmp6_type == MLD6_LISTENER_QUERY) /* XXX: ugly... */
611 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery);
612 		else
613 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport);
614 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
615 			/* give up local */
616 			mld6_input(m, off);
617 			m = NULL;
618 			goto freeit;
619 		}
620 		mld6_input(n, off);
621 		/* m stays. */
622 		break;
623 
624 	case MLD6_LISTENER_DONE:
625 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone);
626 		if (icmp6len < sizeof(struct mld6_hdr))	/* necessary? */
627 			goto badlen;
628 		break;		/* nothing to be done in kernel */
629 
630 	case MLD6_MTRACE_RESP:
631 	case MLD6_MTRACE:
632 		/* XXX: these two are experimental. not officially defind. */
633 		/* XXX: per-interface statistics? */
634 		break;		/* just pass it to applications */
635 
636 	case ICMP6_WRUREQUEST:	/* ICMP6_FQDN_QUERY */
637 	    {
638 		enum { WRU, FQDN } mode;
639 
640 		if (!icmp6_nodeinfo)
641 			break;
642 
643 		if (icmp6len == sizeof(struct icmp6_hdr) + 4)
644 			mode = WRU;
645 		else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
646 			mode = FQDN;
647 		else
648 			goto badlen;
649 
650 #define hostnamelen	strlen(hostname)
651 		if (mode == FQDN) {
652 #ifndef PULLDOWN_TEST
653 			IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
654 					 IPPROTO_DONE);
655 #endif
656 			n = m_copy(m, 0, M_COPYALL);
657 			if (n)
658 				n = ni6_input(n, off);
659 			/* XXX meaningless if n == NULL */
660 			noff = sizeof(struct ip6_hdr);
661 		} else {
662 			u_char *p;
663 			int maxlen, maxhlen;
664 
665 			if ((icmp6_nodeinfo & 5) != 5)
666 				break;
667 
668 			if (code != 0)
669 				goto badcode;
670 			maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
671 			if (maxlen >= MCLBYTES) {
672 				/* Give up remote */
673 				break;
674 			}
675 			MGETHDR(n, M_DONTWAIT, m->m_type);
676 			if (n && maxlen > MHLEN) {
677 				MCLGET(n, M_DONTWAIT);
678 				if ((n->m_flags & M_EXT) == 0) {
679 					m_free(n);
680 					n = NULL;
681 				}
682 			}
683 			if (n == NULL) {
684 				/* Give up remote */
685 				break;
686 			}
687 			n->m_pkthdr.rcvif = NULL;
688 			n->m_len = 0;
689 			maxhlen = M_TRAILINGSPACE(n) - maxlen;
690 			if (maxhlen > hostnamelen)
691 				maxhlen = hostnamelen;
692 			/*
693 			 * Copy IPv6 and ICMPv6 only.
694 			 */
695 			nip6 = mtod(n, struct ip6_hdr *);
696 			bcopy(ip6, nip6, sizeof(struct ip6_hdr));
697 			nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
698 			bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
699 			p = (u_char *)(nicmp6 + 1);
700 			bzero(p, 4);
701 			bcopy(hostname, p + 4, maxhlen); /*meaningless TTL*/
702 			noff = sizeof(struct ip6_hdr);
703 			M_COPY_PKTHDR(n, m); /* just for recvif */
704 			n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
705 				sizeof(struct icmp6_hdr) + 4 + maxhlen;
706 			nicmp6->icmp6_type = ICMP6_WRUREPLY;
707 			nicmp6->icmp6_code = 0;
708 		}
709 #undef hostnamelen
710 		if (n) {
711 			icmp6stat.icp6s_reflect++;
712 			icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++;
713 			icmp6_reflect(n, noff);
714 		}
715 		break;
716 	    }
717 
718 	case ICMP6_WRUREPLY:
719 		if (code != 0)
720 			goto badcode;
721 		break;
722 
723 	case ND_ROUTER_SOLICIT:
724 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit);
725 		if (code != 0)
726 			goto badcode;
727 		if (icmp6len < sizeof(struct nd_router_solicit))
728 			goto badlen;
729 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
730 			/* give up local */
731 			nd6_rs_input(m, off, icmp6len);
732 			m = NULL;
733 			goto freeit;
734 		}
735 		nd6_rs_input(n, off, icmp6len);
736 		/* m stays. */
737 		break;
738 
739 	case ND_ROUTER_ADVERT:
740 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert);
741 		if (code != 0)
742 			goto badcode;
743 		if (icmp6len < sizeof(struct nd_router_advert))
744 			goto badlen;
745 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
746 			/* give up local */
747 			nd6_ra_input(m, off, icmp6len);
748 			m = NULL;
749 			goto freeit;
750 		}
751 		nd6_ra_input(n, off, icmp6len);
752 		/* m stays. */
753 		break;
754 
755 	case ND_NEIGHBOR_SOLICIT:
756 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit);
757 		if (code != 0)
758 			goto badcode;
759 		if (icmp6len < sizeof(struct nd_neighbor_solicit))
760 			goto badlen;
761 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
762 			/* give up local */
763 			nd6_ns_input(m, off, icmp6len);
764 			m = NULL;
765 			goto freeit;
766 		}
767 		nd6_ns_input(n, off, icmp6len);
768 		/* m stays. */
769 		break;
770 
771 	case ND_NEIGHBOR_ADVERT:
772 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert);
773 		if (code != 0)
774 			goto badcode;
775 		if (icmp6len < sizeof(struct nd_neighbor_advert))
776 			goto badlen;
777 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
778 			/* give up local */
779 			nd6_na_input(m, off, icmp6len);
780 			m = NULL;
781 			goto freeit;
782 		}
783 		nd6_na_input(n, off, icmp6len);
784 		/* m stays. */
785 		break;
786 
787 	case ND_REDIRECT:
788 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect);
789 		if (code != 0)
790 			goto badcode;
791 		if (icmp6len < sizeof(struct nd_redirect))
792 			goto badlen;
793 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
794 			/* give up local */
795 			icmp6_redirect_input(m, off);
796 			m = NULL;
797 			goto freeit;
798 		}
799 		icmp6_redirect_input(n, off);
800 		/* m stays. */
801 		break;
802 
803 	case ICMP6_ROUTER_RENUMBERING:
804 		if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
805 		    code != ICMP6_ROUTER_RENUMBERING_RESULT)
806 			goto badcode;
807 		if (icmp6len < sizeof(struct icmp6_router_renum))
808 			goto badlen;
809 		break;
810 
811 	default:
812 		nd6log((LOG_DEBUG,
813 		    "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
814 		    icmp6->icmp6_type, ip6_sprintf(&ip6->ip6_src),
815 		    ip6_sprintf(&ip6->ip6_dst),
816 		    m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0));
817 		if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
818 			/* ICMPv6 error: MUST deliver it by spec... */
819 			code = PRC_NCMDS;
820 			/* deliver */
821 		} else {
822 			/* ICMPv6 informational: MUST not deliver */
823 			break;
824 		}
825 	deliver:
826 		if (icmp6_notify_error(m, off, icmp6len, code)) {
827 			/* In this case, m should've been freed. */
828 			return(IPPROTO_DONE);
829 		}
830 		break;
831 
832 	badcode:
833 		icmp6stat.icp6s_badcode++;
834 		break;
835 
836 	badlen:
837 		icmp6stat.icp6s_badlen++;
838 		break;
839 	}
840 
841 	/* deliver the packet to appropriate sockets */
842 	icmp6_rip6_input(&m, *offp);
843 
844 	return IPPROTO_DONE;
845 
846  freeit:
847 	m_freem(m);
848 	return IPPROTO_DONE;
849 }
850 
851 static int
852 icmp6_notify_error(m, off, icmp6len, code)
853 	struct mbuf *m;
854 	int off, icmp6len;
855 {
856 	struct icmp6_hdr *icmp6;
857 	struct ip6_hdr *eip6;
858 	u_int32_t notifymtu;
859 	struct sockaddr_in6 icmp6src, icmp6dst;
860 
861 	if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
862 		icmp6stat.icp6s_tooshort++;
863 		goto freeit;
864 	}
865 #ifndef PULLDOWN_TEST
866 	IP6_EXTHDR_CHECK(m, off,
867 			 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr),
868 			 -1);
869 	icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
870 #else
871 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
872 		       sizeof(*icmp6) + sizeof(struct ip6_hdr));
873 	if (icmp6 == NULL) {
874 		icmp6stat.icp6s_tooshort++;
875 		return(-1);
876 	}
877 #endif
878 	eip6 = (struct ip6_hdr *)(icmp6 + 1);
879 
880 	/* Detect the upper level protocol */
881 	{
882 		void (*ctlfunc) __P((int, struct sockaddr *, void *));
883 		u_int8_t nxt = eip6->ip6_nxt;
884 		int eoff = off + sizeof(struct icmp6_hdr) +
885 			sizeof(struct ip6_hdr);
886 		struct ip6ctlparam ip6cp;
887 		struct in6_addr *finaldst = NULL;
888 		int icmp6type = icmp6->icmp6_type;
889 		struct ip6_frag *fh;
890 		struct ip6_rthdr *rth;
891 		struct ip6_rthdr0 *rth0;
892 		int rthlen;
893 
894 		while (1) { /* XXX: should avoid inf. loop explicitly? */
895 			struct ip6_ext *eh;
896 
897 			switch (nxt) {
898 			case IPPROTO_HOPOPTS:
899 			case IPPROTO_DSTOPTS:
900 			case IPPROTO_AH:
901 #ifndef PULLDOWN_TEST
902 				IP6_EXTHDR_CHECK(m, 0, eoff +
903 						 sizeof(struct ip6_ext),
904 						 -1);
905 				eh = (struct ip6_ext *)(mtod(m, caddr_t)
906 							+ eoff);
907 #else
908 				IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
909 					       eoff, sizeof(*eh));
910 				if (eh == NULL) {
911 					icmp6stat.icp6s_tooshort++;
912 					return(-1);
913 				}
914 #endif
915 
916 				if (nxt == IPPROTO_AH)
917 					eoff += (eh->ip6e_len + 2) << 2;
918 				else
919 					eoff += (eh->ip6e_len + 1) << 3;
920 				nxt = eh->ip6e_nxt;
921 				break;
922 			case IPPROTO_ROUTING:
923 				/*
924 				 * When the erroneous packet contains a
925 				 * routing header, we should examine the
926 				 * header to determine the final destination.
927 				 * Otherwise, we can't properly update
928 				 * information that depends on the final
929 				 * destination (e.g. path MTU).
930 				 */
931 #ifndef PULLDOWN_TEST
932 				IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth),
933 						 -1);
934 				rth = (struct ip6_rthdr *)(mtod(m, caddr_t)
935 							   + eoff);
936 #else
937 				IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
938 					       eoff, sizeof(*rth));
939 				if (rth == NULL) {
940 					icmp6stat.icp6s_tooshort++;
941 					return(-1);
942 				}
943 #endif
944 				rthlen = (rth->ip6r_len + 1) << 3;
945 				/*
946 				 * XXX: currently there is no
947 				 * officially defined type other
948 				 * than type-0.
949 				 * Note that if the segment left field
950 				 * is 0, all intermediate hops must
951 				 * have been passed.
952 				 */
953 				if (rth->ip6r_segleft &&
954 				    rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
955 					int hops;
956 
957 #ifndef PULLDOWN_TEST
958 					IP6_EXTHDR_CHECK(m, 0, eoff + rthlen,
959 							 -1);
960 					rth0 = (struct ip6_rthdr0 *)(mtod(m, caddr_t) + eoff);
961 #else
962 					IP6_EXTHDR_GET(rth0,
963 						       struct ip6_rthdr0 *, m,
964 						       eoff, rthlen);
965 					if (rth0 == NULL) {
966 						icmp6stat.icp6s_tooshort++;
967 						return(-1);
968 					}
969 #endif
970 					/* just ignore a bogus header */
971 					if ((rth0->ip6r0_len % 2) == 0 &&
972 					    (hops = rth0->ip6r0_len/2))
973 						finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
974 				}
975 				eoff += rthlen;
976 				nxt = rth->ip6r_nxt;
977 				break;
978 			case IPPROTO_FRAGMENT:
979 #ifndef PULLDOWN_TEST
980 				IP6_EXTHDR_CHECK(m, 0, eoff +
981 						 sizeof(struct ip6_frag),
982 						 -1);
983 				fh = (struct ip6_frag *)(mtod(m, caddr_t)
984 							 + eoff);
985 #else
986 				IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
987 					       eoff, sizeof(*fh));
988 				if (fh == NULL) {
989 					icmp6stat.icp6s_tooshort++;
990 					return(-1);
991 				}
992 #endif
993 				/*
994 				 * Data after a fragment header is meaningless
995 				 * unless it is the first fragment, but
996 				 * we'll go to the notify label for path MTU
997 				 * discovery.
998 				 */
999 				if (fh->ip6f_offlg & IP6F_OFF_MASK)
1000 					goto notify;
1001 
1002 				eoff += sizeof(struct ip6_frag);
1003 				nxt = fh->ip6f_nxt;
1004 				break;
1005 			default:
1006 				/*
1007 				 * This case includes ESP and the No Next
1008 				 * Header. In such cases going to the notify
1009 				 * label does not have any meaning
1010 				 * (i.e. ctlfunc will be NULL), but we go
1011 				 * anyway since we might have to update
1012 				 * path MTU information.
1013 				 */
1014 				goto notify;
1015 			}
1016 		}
1017 	  notify:
1018 #ifndef PULLDOWN_TEST
1019 		icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1020 #else
1021 		IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1022 			       sizeof(*icmp6) + sizeof(struct ip6_hdr));
1023 		if (icmp6 == NULL) {
1024 			icmp6stat.icp6s_tooshort++;
1025 			return(-1);
1026 		}
1027 #endif
1028 
1029 		eip6 = (struct ip6_hdr *)(icmp6 + 1);
1030 		bzero(&icmp6dst, sizeof(icmp6dst));
1031 		icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1032 		icmp6dst.sin6_family = AF_INET6;
1033 		if (finaldst == NULL)
1034 			icmp6dst.sin6_addr = eip6->ip6_dst;
1035 		else
1036 			icmp6dst.sin6_addr = *finaldst;
1037 		icmp6dst.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
1038 							  &icmp6dst.sin6_addr);
1039 #ifndef SCOPEDROUTING
1040 		if (in6_embedscope(&icmp6dst.sin6_addr, &icmp6dst,
1041 				   NULL, NULL)) {
1042 			/* should be impossbile */
1043 			nd6log((LOG_DEBUG,
1044 			    "icmp6_notify_error: in6_embedscope failed\n"));
1045 			goto freeit;
1046 		}
1047 #endif
1048 
1049 		/*
1050 		 * retrieve parameters from the inner IPv6 header, and convert
1051 		 * them into sockaddr structures.
1052 		 */
1053 		bzero(&icmp6src, sizeof(icmp6src));
1054 		icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1055 		icmp6src.sin6_family = AF_INET6;
1056 		icmp6src.sin6_addr = eip6->ip6_src;
1057 		icmp6src.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
1058 							  &icmp6src.sin6_addr);
1059 #ifndef SCOPEDROUTING
1060 		if (in6_embedscope(&icmp6src.sin6_addr, &icmp6src,
1061 				   NULL, NULL)) {
1062 			/* should be impossbile */
1063 			nd6log((LOG_DEBUG,
1064 			    "icmp6_notify_error: in6_embedscope failed\n"));
1065 			goto freeit;
1066 		}
1067 #endif
1068 		icmp6src.sin6_flowinfo =
1069 			(eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1070 
1071 		if (finaldst == NULL)
1072 			finaldst = &eip6->ip6_dst;
1073 		ip6cp.ip6c_m = m;
1074 		ip6cp.ip6c_icmp6 = icmp6;
1075 		ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1076 		ip6cp.ip6c_off = eoff;
1077 		ip6cp.ip6c_finaldst = finaldst;
1078 		ip6cp.ip6c_src = &icmp6src;
1079 		ip6cp.ip6c_nxt = nxt;
1080 
1081 		if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1082 			notifymtu = ntohl(icmp6->icmp6_mtu);
1083 			ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1084 			icmp6_mtudisc_update(&ip6cp, 1);	/*XXX*/
1085 		}
1086 
1087 		ctlfunc = (void (*) __P((int, struct sockaddr *, void *)))
1088 			(inet6sw[ip6_protox[nxt]].pr_ctlinput);
1089 		if (ctlfunc) {
1090 			(void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1091 					  &ip6cp);
1092 		}
1093 	}
1094 	return(0);
1095 
1096   freeit:
1097 	m_freem(m);
1098 	return(-1);
1099 }
1100 
1101 void
1102 icmp6_mtudisc_update(ip6cp, validated)
1103 	struct ip6ctlparam *ip6cp;
1104 	int validated;
1105 {
1106 	struct in6_addr *dst = ip6cp->ip6c_finaldst;
1107 	struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1108 	struct mbuf *m = ip6cp->ip6c_m;	/* will be necessary for scope issue */
1109 	u_int mtu = ntohl(icmp6->icmp6_mtu);
1110 	struct rtentry *rt = NULL;
1111 	struct sockaddr_in6 sin6;
1112 
1113 	if (!validated)
1114 		return;
1115 
1116 	bzero(&sin6, sizeof(sin6));
1117 	sin6.sin6_family = PF_INET6;
1118 	sin6.sin6_len = sizeof(struct sockaddr_in6);
1119 	sin6.sin6_addr = *dst;
1120 	/* XXX normally, this won't happen */
1121 	if (IN6_IS_ADDR_LINKLOCAL(dst)) {
1122 		sin6.sin6_addr.s6_addr16[1] =
1123 		    htons(m->m_pkthdr.rcvif->if_index);
1124 	}
1125 	/* sin6.sin6_scope_id = XXX: should be set if DST is a scoped addr */
1126 	rt = rtalloc1((struct sockaddr *)&sin6, 0,
1127 		      RTF_CLONING | RTF_PRCLONING);
1128 
1129 	if (rt && (rt->rt_flags & RTF_HOST)
1130 	    && !(rt->rt_rmx.rmx_locks & RTV_MTU)) {
1131 		if (mtu < IPV6_MMTU) {
1132 				/* xxx */
1133 			rt->rt_rmx.rmx_locks |= RTV_MTU;
1134 		} else if (mtu < rt->rt_ifp->if_mtu &&
1135 			   rt->rt_rmx.rmx_mtu > mtu) {
1136 			icmp6stat.icp6s_pmtuchg++;
1137 			rt->rt_rmx.rmx_mtu = mtu;
1138 		}
1139 	}
1140 	if (rt)
1141 		RTFREE(rt);
1142 }
1143 
1144 /*
1145  * Process a Node Information Query packet, based on
1146  * draft-ietf-ipngwg-icmp-name-lookups-07.
1147  *
1148  * Spec incompatibilities:
1149  * - IPv6 Subject address handling
1150  * - IPv4 Subject address handling support missing
1151  * - Proxy reply (answer even if it's not for me)
1152  * - joins NI group address at in6_ifattach() time only, does not cope
1153  *   with hostname changes by sethostname(3)
1154  */
1155 #define hostnamelen	strlen(hostname)
1156 static struct mbuf *
1157 ni6_input(m, off)
1158 	struct mbuf *m;
1159 	int off;
1160 {
1161 	struct icmp6_nodeinfo *ni6, *nni6;
1162 	struct mbuf *n = NULL;
1163 	u_int16_t qtype;
1164 	int subjlen;
1165 	int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1166 	struct ni_reply_fqdn *fqdn;
1167 	int addrs;		/* for NI_QTYPE_NODEADDR */
1168 	struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1169 	struct sockaddr_in6 sin6; /* double meaning; ip6_dst and subjectaddr */
1170 	struct sockaddr_in6 sin6_d; /* XXX: we should retrieve this from m_aux */
1171 	struct ip6_hdr *ip6;
1172 	int oldfqdn = 0;	/* if 1, return pascal string (03 draft) */
1173 	char *subj = NULL;
1174 	struct in6_ifaddr *ia6 = NULL;
1175 
1176 	ip6 = mtod(m, struct ip6_hdr *);
1177 #ifndef PULLDOWN_TEST
1178 	ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1179 #else
1180 	IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1181 	if (ni6 == NULL) {
1182 		/* m is already reclaimed */
1183 		return NULL;
1184 	}
1185 #endif
1186 
1187 	/*
1188 	 * Validate IPv6 destination address.
1189 	 *
1190 	 * The Responder must discard the Query without further processing
1191 	 * unless it is one of the Responder's unicast or anycast addresses, or
1192 	 * a link-local scope multicast address which the Responder has joined.
1193 	 * [icmp-name-lookups-07, Section 4.]
1194 	 */
1195 	bzero(&sin6, sizeof(sin6));
1196 	sin6.sin6_family = AF_INET6;
1197 	sin6.sin6_len = sizeof(struct sockaddr_in6);
1198 	bcopy(&ip6->ip6_dst, &sin6.sin6_addr, sizeof(sin6.sin6_addr));
1199 	/* XXX scopeid */
1200 	if ((ia6 = (struct in6_ifaddr *)ifa_ifwithaddr((struct sockaddr *)&sin6)) != NULL) {
1201 		/* unicast/anycast, fine */
1202 		if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1203 		    (icmp6_nodeinfo & 4) == 0) {
1204 			nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1205 				"a temporary address in %s:%d",
1206 			       __FILE__, __LINE__));
1207 			goto bad;
1208 		}
1209 	} else if (IN6_IS_ADDR_MC_LINKLOCAL(&sin6.sin6_addr))
1210 		; /* link-local multicast, fine */
1211 	else
1212 		goto bad;
1213 
1214 	/* validate query Subject field. */
1215 	qtype = ntohs(ni6->ni_qtype);
1216 	subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1217 	switch (qtype) {
1218 	case NI_QTYPE_NOOP:
1219 	case NI_QTYPE_SUPTYPES:
1220 		/* 07 draft */
1221 		if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1222 			break;
1223 		/* FALLTHROUGH */
1224 	case NI_QTYPE_FQDN:
1225 	case NI_QTYPE_NODEADDR:
1226 		switch (ni6->ni_code) {
1227 		case ICMP6_NI_SUBJ_IPV6:
1228 #if ICMP6_NI_SUBJ_IPV6 != 0
1229 		case 0:
1230 #endif
1231 			/*
1232 			 * backward compatibility - try to accept 03 draft
1233 			 * format, where no Subject is present.
1234 			 */
1235 			if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1236 			    subjlen == 0) {
1237 				oldfqdn++;
1238 				break;
1239 			}
1240 #if ICMP6_NI_SUBJ_IPV6 != 0
1241 			if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1242 				goto bad;
1243 #endif
1244 
1245 			if (subjlen != sizeof(sin6.sin6_addr))
1246 				goto bad;
1247 
1248 			/*
1249 			 * Validate Subject address.
1250 			 *
1251 			 * Not sure what exactly "address belongs to the node"
1252 			 * means in the spec, is it just unicast, or what?
1253 			 *
1254 			 * At this moment we consider Subject address as
1255 			 * "belong to the node" if the Subject address equals
1256 			 * to the IPv6 destination address; validation for
1257 			 * IPv6 destination address should have done enough
1258 			 * check for us.
1259 			 *
1260 			 * We do not do proxy at this moment.
1261 			 */
1262 			/* m_pulldown instead of copy? */
1263 			m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1264 			    subjlen, (caddr_t)&sin6.sin6_addr);
1265 			sin6.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
1266 							      &sin6.sin6_addr);
1267 #ifndef SCOPEDROUTING
1268 			in6_embedscope(&sin6.sin6_addr, &sin6, NULL, NULL);
1269 #endif
1270 			bzero(&sin6_d, sizeof(sin6_d));
1271 			sin6_d.sin6_family = AF_INET6; /* not used, actually */
1272 			sin6_d.sin6_len = sizeof(sin6_d); /* ditto */
1273 			sin6_d.sin6_addr = ip6->ip6_dst;
1274 			sin6_d.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
1275 								&ip6->ip6_dst);
1276 #ifndef SCOPEDROUTING
1277 			in6_embedscope(&sin6_d.sin6_addr, &sin6_d, NULL, NULL);
1278 #endif
1279 			subj = (char *)&sin6;
1280 			if (SA6_ARE_ADDR_EQUAL(&sin6, &sin6_d))
1281 				break;
1282 
1283 			/*
1284 			 * XXX if we are to allow other cases, we should really
1285 			 * be careful about scope here.
1286 			 * basically, we should disallow queries toward IPv6
1287 			 * destination X with subject Y, if scope(X) > scope(Y).
1288 			 * if we allow scope(X) > scope(Y), it will result in
1289 			 * information leakage across scope boundary.
1290 			 */
1291 			goto bad;
1292 
1293 		case ICMP6_NI_SUBJ_FQDN:
1294 			/*
1295 			 * Validate Subject name with gethostname(3).
1296 			 *
1297 			 * The behavior may need some debate, since:
1298 			 * - we are not sure if the node has FQDN as
1299 			 *   hostname (returned by gethostname(3)).
1300 			 * - the code does wildcard match for truncated names.
1301 			 *   however, we are not sure if we want to perform
1302 			 *   wildcard match, if gethostname(3) side has
1303 			 *   truncated hostname.
1304 			 */
1305 			n = ni6_nametodns(hostname, hostnamelen, 0);
1306 			if (!n || n->m_next || n->m_len == 0)
1307 				goto bad;
1308 			IP6_EXTHDR_GET(subj, char *, m,
1309 			    off + sizeof(struct icmp6_nodeinfo), subjlen);
1310 			if (subj == NULL)
1311 				goto bad;
1312 			if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1313 					n->m_len)) {
1314 				goto bad;
1315 			}
1316 			m_freem(n);
1317 			n = NULL;
1318 			break;
1319 
1320 		case ICMP6_NI_SUBJ_IPV4:	/* XXX: to be implemented? */
1321 		default:
1322 			goto bad;
1323 		}
1324 		break;
1325 	}
1326 
1327 	/* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1328 	switch (qtype) {
1329 	case NI_QTYPE_FQDN:
1330 		if ((icmp6_nodeinfo & 1) == 0)
1331 			goto bad;
1332 		break;
1333 	case NI_QTYPE_NODEADDR:
1334 		if ((icmp6_nodeinfo & 2) == 0)
1335 			goto bad;
1336 		break;
1337 	}
1338 
1339 	/* guess reply length */
1340 	switch (qtype) {
1341 	case NI_QTYPE_NOOP:
1342 		break;		/* no reply data */
1343 	case NI_QTYPE_SUPTYPES:
1344 		replylen += sizeof(u_int32_t);
1345 		break;
1346 	case NI_QTYPE_FQDN:
1347 		/* XXX will append an mbuf */
1348 		replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1349 		break;
1350 	case NI_QTYPE_NODEADDR:
1351 		addrs = ni6_addrs(ni6, m, &ifp, subj);
1352 		if ((replylen += addrs * (sizeof(struct in6_addr) +
1353 					  sizeof(u_int32_t))) > MCLBYTES)
1354 			replylen = MCLBYTES; /* XXX: will truncate pkt later */
1355 		break;
1356 	default:
1357 		/*
1358 		 * XXX: We must return a reply with the ICMP6 code
1359 		 * `unknown Qtype' in this case. However we regard the case
1360 		 * as an FQDN query for backward compatibility.
1361 		 * Older versions set a random value to this field,
1362 		 * so it rarely varies in the defined qtypes.
1363 		 * But the mechanism is not reliable...
1364 		 * maybe we should obsolete older versions.
1365 		 */
1366 		qtype = NI_QTYPE_FQDN;
1367 		/* XXX will append an mbuf */
1368 		replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1369 		oldfqdn++;
1370 		break;
1371 	}
1372 
1373 	/* allocate an mbuf to reply. */
1374 	MGETHDR(n, M_DONTWAIT, m->m_type);
1375 	if (n == NULL) {
1376 		m_freem(m);
1377 		return(NULL);
1378 	}
1379 	M_COPY_PKTHDR(n, m); /* just for recvif */
1380 	if (replylen > MHLEN) {
1381 		if (replylen > MCLBYTES) {
1382 			/*
1383 			 * XXX: should we try to allocate more? But MCLBYTES
1384 			 * is probably much larger than IPV6_MMTU...
1385 			 */
1386 			goto bad;
1387 		}
1388 		MCLGET(n, M_DONTWAIT);
1389 		if ((n->m_flags & M_EXT) == 0) {
1390 			goto bad;
1391 		}
1392 	}
1393 	n->m_pkthdr.len = n->m_len = replylen;
1394 
1395 	/* copy mbuf header and IPv6 + Node Information base headers */
1396 	bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1397 	nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1398 	bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1399 
1400 	/* qtype dependent procedure */
1401 	switch (qtype) {
1402 	case NI_QTYPE_NOOP:
1403 		nni6->ni_code = ICMP6_NI_SUCCESS;
1404 		nni6->ni_flags = 0;
1405 		break;
1406 	case NI_QTYPE_SUPTYPES:
1407 	{
1408 		u_int32_t v;
1409 		nni6->ni_code = ICMP6_NI_SUCCESS;
1410 		nni6->ni_flags = htons(0x0000);	/* raw bitmap */
1411 		/* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1412 		v = (u_int32_t)htonl(0x0000000f);
1413 		bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1414 		break;
1415 	}
1416 	case NI_QTYPE_FQDN:
1417 		nni6->ni_code = ICMP6_NI_SUCCESS;
1418 		fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1419 						sizeof(struct ip6_hdr) +
1420 						sizeof(struct icmp6_nodeinfo));
1421 		nni6->ni_flags = 0; /* XXX: meaningless TTL */
1422 		fqdn->ni_fqdn_ttl = 0;	/* ditto. */
1423 		/*
1424 		 * XXX do we really have FQDN in variable "hostname"?
1425 		 */
1426 		n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn);
1427 		if (n->m_next == NULL)
1428 			goto bad;
1429 		/* XXX we assume that n->m_next is not a chain */
1430 		if (n->m_next->m_next != NULL)
1431 			goto bad;
1432 		n->m_pkthdr.len += n->m_next->m_len;
1433 		break;
1434 	case NI_QTYPE_NODEADDR:
1435 	{
1436 		int lenlim, copied;
1437 
1438 		nni6->ni_code = ICMP6_NI_SUCCESS;
1439 		n->m_pkthdr.len = n->m_len =
1440 		    sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1441 		lenlim = M_TRAILINGSPACE(n);
1442 		copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1443 		/* XXX: reset mbuf length */
1444 		n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1445 			sizeof(struct icmp6_nodeinfo) + copied;
1446 		break;
1447 	}
1448 	default:
1449 		break;		/* XXX impossible! */
1450 	}
1451 
1452 	nni6->ni_type = ICMP6_NI_REPLY;
1453 	m_freem(m);
1454 	return(n);
1455 
1456   bad:
1457 	m_freem(m);
1458 	if (n)
1459 		m_freem(n);
1460 	return(NULL);
1461 }
1462 #undef hostnamelen
1463 
1464 /*
1465  * make a mbuf with DNS-encoded string.  no compression support.
1466  *
1467  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1468  * treated as truncated name (two \0 at the end).  this is a wild guess.
1469  */
1470 static struct mbuf *
1471 ni6_nametodns(name, namelen, old)
1472 	const char *name;
1473 	int namelen;
1474 	int old;	/* return pascal string if non-zero */
1475 {
1476 	struct mbuf *m;
1477 	char *cp, *ep;
1478 	const char *p, *q;
1479 	int i, len, nterm;
1480 
1481 	if (old)
1482 		len = namelen + 1;
1483 	else
1484 		len = MCLBYTES;
1485 
1486 	/* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1487 	MGET(m, M_DONTWAIT, MT_DATA);
1488 	if (m && len > MLEN) {
1489 		MCLGET(m, M_DONTWAIT);
1490 		if ((m->m_flags & M_EXT) == 0)
1491 			goto fail;
1492 	}
1493 	if (!m)
1494 		goto fail;
1495 	m->m_next = NULL;
1496 
1497 	if (old) {
1498 		m->m_len = len;
1499 		*mtod(m, char *) = namelen;
1500 		bcopy(name, mtod(m, char *) + 1, namelen);
1501 		return m;
1502 	} else {
1503 		m->m_len = 0;
1504 		cp = mtod(m, char *);
1505 		ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1506 
1507 		/* if not certain about my name, return empty buffer */
1508 		if (namelen == 0)
1509 			return m;
1510 
1511 		/*
1512 		 * guess if it looks like shortened hostname, or FQDN.
1513 		 * shortened hostname needs two trailing "\0".
1514 		 */
1515 		i = 0;
1516 		for (p = name; p < name + namelen; p++) {
1517 			if (*p && *p == '.')
1518 				i++;
1519 		}
1520 		if (i < 2)
1521 			nterm = 2;
1522 		else
1523 			nterm = 1;
1524 
1525 		p = name;
1526 		while (cp < ep && p < name + namelen) {
1527 			i = 0;
1528 			for (q = p; q < name + namelen && *q && *q != '.'; q++)
1529 				i++;
1530 			/* result does not fit into mbuf */
1531 			if (cp + i + 1 >= ep)
1532 				goto fail;
1533 			/*
1534 			 * DNS label length restriction, RFC1035 page 8.
1535 			 * "i == 0" case is included here to avoid returning
1536 			 * 0-length label on "foo..bar".
1537 			 */
1538 			if (i <= 0 || i >= 64)
1539 				goto fail;
1540 			*cp++ = i;
1541 			bcopy(p, cp, i);
1542 			cp += i;
1543 			p = q;
1544 			if (p < name + namelen && *p == '.')
1545 				p++;
1546 		}
1547 		/* termination */
1548 		if (cp + nterm >= ep)
1549 			goto fail;
1550 		while (nterm-- > 0)
1551 			*cp++ = '\0';
1552 		m->m_len = cp - mtod(m, char *);
1553 		return m;
1554 	}
1555 
1556 	panic("should not reach here");
1557 	/*NOTREACHED*/
1558 
1559  fail:
1560 	if (m)
1561 		m_freem(m);
1562 	return NULL;
1563 }
1564 
1565 /*
1566  * check if two DNS-encoded string matches.  takes care of truncated
1567  * form (with \0\0 at the end).  no compression support.
1568  * XXX upper/lowercase match (see RFC2065)
1569  */
1570 static int
1571 ni6_dnsmatch(a, alen, b, blen)
1572 	const char *a;
1573 	int alen;
1574 	const char *b;
1575 	int blen;
1576 {
1577 	const char *a0, *b0;
1578 	int l;
1579 
1580 	/* simplest case - need validation? */
1581 	if (alen == blen && bcmp(a, b, alen) == 0)
1582 		return 1;
1583 
1584 	a0 = a;
1585 	b0 = b;
1586 
1587 	/* termination is mandatory */
1588 	if (alen < 2 || blen < 2)
1589 		return 0;
1590 	if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1591 		return 0;
1592 	alen--;
1593 	blen--;
1594 
1595 	while (a - a0 < alen && b - b0 < blen) {
1596 		if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1597 			return 0;
1598 
1599 		if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1600 			return 0;
1601 		/* we don't support compression yet */
1602 		if (a[0] >= 64 || b[0] >= 64)
1603 			return 0;
1604 
1605 		/* truncated case */
1606 		if (a[0] == 0 && a - a0 == alen - 1)
1607 			return 1;
1608 		if (b[0] == 0 && b - b0 == blen - 1)
1609 			return 1;
1610 		if (a[0] == 0 || b[0] == 0)
1611 			return 0;
1612 
1613 		if (a[0] != b[0])
1614 			return 0;
1615 		l = a[0];
1616 		if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1617 			return 0;
1618 		if (bcmp(a + 1, b + 1, l) != 0)
1619 			return 0;
1620 
1621 		a += 1 + l;
1622 		b += 1 + l;
1623 	}
1624 
1625 	if (a - a0 == alen && b - b0 == blen)
1626 		return 1;
1627 	else
1628 		return 0;
1629 }
1630 
1631 /*
1632  * calculate the number of addresses to be returned in the node info reply.
1633  */
1634 static int
1635 ni6_addrs(ni6, m, ifpp, subj)
1636 	struct icmp6_nodeinfo *ni6;
1637 	struct mbuf *m;
1638 	struct ifnet **ifpp;
1639 	char *subj;
1640 {
1641 	struct ifnet *ifp;
1642 	struct in6_ifaddr *ifa6;
1643 	struct ifaddr *ifa;
1644 	struct sockaddr_in6 *subj_ip6 = NULL; /* XXX pedant */
1645 	int addrs = 0, addrsofif, iffound = 0;
1646 	int niflags = ni6->ni_flags;
1647 
1648 	if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1649 		switch (ni6->ni_code) {
1650 		case ICMP6_NI_SUBJ_IPV6:
1651 			if (subj == NULL) /* must be impossible... */
1652 				return(0);
1653 			subj_ip6 = (struct sockaddr_in6 *)subj;
1654 			break;
1655 		default:
1656 			/*
1657 			 * XXX: we only support IPv6 subject address for
1658 			 * this Qtype.
1659 			 */
1660 			return(0);
1661 		}
1662 	}
1663 
1664 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
1665 	{
1666 		addrsofif = 0;
1667 		TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1668 		{
1669 			if (ifa->ifa_addr->sa_family != AF_INET6)
1670 				continue;
1671 			ifa6 = (struct in6_ifaddr *)ifa;
1672 
1673 			if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1674 			    IN6_ARE_ADDR_EQUAL(&subj_ip6->sin6_addr,
1675 					       &ifa6->ia_addr.sin6_addr))
1676 				iffound = 1;
1677 
1678 			/*
1679 			 * IPv4-mapped addresses can only be returned by a
1680 			 * Node Information proxy, since they represent
1681 			 * addresses of IPv4-only nodes, which perforce do
1682 			 * not implement this protocol.
1683 			 * [icmp-name-lookups-07, Section 5.4]
1684 			 * So we don't support NI_NODEADDR_FLAG_COMPAT in
1685 			 * this function at this moment.
1686 			 */
1687 
1688 			/* What do we have to do about ::1? */
1689 			switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1690 			case IPV6_ADDR_SCOPE_LINKLOCAL:
1691 				if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1692 					continue;
1693 				break;
1694 			case IPV6_ADDR_SCOPE_SITELOCAL:
1695 				if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1696 					continue;
1697 				break;
1698 			case IPV6_ADDR_SCOPE_GLOBAL:
1699 				if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1700 					continue;
1701 				break;
1702 			default:
1703 				continue;
1704 			}
1705 
1706 			/*
1707 			 * check if anycast is okay.
1708 			 * XXX: just experimental. not in the spec.
1709 			 */
1710 			if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1711 			    (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1712 				continue; /* we need only unicast addresses */
1713 			if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1714 			    (icmp6_nodeinfo & 4) == 0) {
1715 				continue;
1716 			}
1717 			addrsofif++; /* count the address */
1718 		}
1719 		if (iffound) {
1720 			*ifpp = ifp;
1721 			return(addrsofif);
1722 		}
1723 
1724 		addrs += addrsofif;
1725 	}
1726 
1727 	return(addrs);
1728 }
1729 
1730 static int
1731 ni6_store_addrs(ni6, nni6, ifp0, resid)
1732 	struct icmp6_nodeinfo *ni6, *nni6;
1733 	struct ifnet *ifp0;
1734 	int resid;
1735 {
1736 	struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet);
1737 	struct in6_ifaddr *ifa6;
1738 	struct ifaddr *ifa;
1739 	struct ifnet *ifp_dep = NULL;
1740 	int copied = 0, allow_deprecated = 0;
1741 	u_char *cp = (u_char *)(nni6 + 1);
1742 	int niflags = ni6->ni_flags;
1743 	u_int32_t ltime;
1744 
1745 	if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1746 		return(0);	/* needless to copy */
1747 
1748   again:
1749 
1750 	for (; ifp; ifp = TAILQ_NEXT(ifp, if_list))
1751 	{
1752 		for (ifa = ifp->if_addrlist.tqh_first; ifa;
1753 		     ifa = ifa->ifa_list.tqe_next)
1754 		{
1755 			if (ifa->ifa_addr->sa_family != AF_INET6)
1756 				continue;
1757 			ifa6 = (struct in6_ifaddr *)ifa;
1758 
1759 			if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1760 			    allow_deprecated == 0) {
1761 				/*
1762 				 * prefererred address should be put before
1763 				 * deprecated addresses.
1764 				 */
1765 
1766 				/* record the interface for later search */
1767 				if (ifp_dep == NULL)
1768 					ifp_dep = ifp;
1769 
1770 				continue;
1771 			}
1772 			else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1773 				 allow_deprecated != 0)
1774 				continue; /* we now collect deprecated addrs */
1775 
1776 			/* What do we have to do about ::1? */
1777 			switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1778 			case IPV6_ADDR_SCOPE_LINKLOCAL:
1779 				if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1780 					continue;
1781 				break;
1782 			case IPV6_ADDR_SCOPE_SITELOCAL:
1783 				if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1784 					continue;
1785 				break;
1786 			case IPV6_ADDR_SCOPE_GLOBAL:
1787 				if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1788 					continue;
1789 				break;
1790 			default:
1791 				continue;
1792 			}
1793 
1794 			/*
1795 			 * check if anycast is okay.
1796 			 * XXX: just experimental. not in the spec.
1797 			 */
1798 			if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1799 			    (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1800 				continue;
1801 			if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1802 			    (icmp6_nodeinfo & 4) == 0) {
1803 				continue;
1804 			}
1805 
1806 			/* now we can copy the address */
1807 			if (resid < sizeof(struct in6_addr) +
1808 			    sizeof(u_int32_t)) {
1809 				/*
1810 				 * We give up much more copy.
1811 				 * Set the truncate flag and return.
1812 				 */
1813 				nni6->ni_flags |=
1814 					NI_NODEADDR_FLAG_TRUNCATE;
1815 				return(copied);
1816 			}
1817 
1818 			/*
1819 			 * Set the TTL of the address.
1820 			 * The TTL value should be one of the following
1821 			 * according to the specification:
1822 			 *
1823 			 * 1. The remaining lifetime of a DHCP lease on the
1824 			 *    address, or
1825 			 * 2. The remaining Valid Lifetime of a prefix from
1826 			 *    which the address was derived through Stateless
1827 			 *    Autoconfiguration.
1828 			 *
1829 			 * Note that we currently do not support stateful
1830 			 * address configuration by DHCPv6, so the former
1831 			 * case can't happen.
1832 			 */
1833 			if (ifa6->ia6_lifetime.ia6t_expire == 0)
1834 				ltime = ND6_INFINITE_LIFETIME;
1835 			else {
1836 				if (ifa6->ia6_lifetime.ia6t_expire >
1837 				    time_second)
1838 					ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second);
1839 				else
1840 					ltime = 0;
1841 			}
1842 
1843 			bcopy(&ltime, cp, sizeof(u_int32_t));
1844 			cp += sizeof(u_int32_t);
1845 
1846 			/* copy the address itself */
1847 			bcopy(&ifa6->ia_addr.sin6_addr, cp,
1848 			      sizeof(struct in6_addr));
1849 			/* XXX: KAME link-local hack; remove ifindex */
1850 			if (IN6_IS_ADDR_LINKLOCAL(&ifa6->ia_addr.sin6_addr))
1851 				((struct in6_addr *)cp)->s6_addr16[1] = 0;
1852 			cp += sizeof(struct in6_addr);
1853 
1854 			resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1855 			copied += (sizeof(struct in6_addr) +
1856 				   sizeof(u_int32_t));
1857 		}
1858 		if (ifp0)	/* we need search only on the specified IF */
1859 			break;
1860 	}
1861 
1862 	if (allow_deprecated == 0 && ifp_dep != NULL) {
1863 		ifp = ifp_dep;
1864 		allow_deprecated = 1;
1865 
1866 		goto again;
1867 	}
1868 
1869 	return(copied);
1870 }
1871 
1872 /*
1873  * XXX almost dup'ed code with rip6_input.
1874  */
1875 static int
1876 icmp6_rip6_input(mp, off)
1877 	struct	mbuf **mp;
1878 	int	off;
1879 {
1880 	struct mbuf *m = *mp;
1881 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1882 	struct in6pcb *in6p;
1883 	struct in6pcb *last = NULL;
1884 	struct sockaddr_in6 rip6src;
1885 	struct icmp6_hdr *icmp6;
1886 	struct mbuf *opts = NULL;
1887 
1888 #ifndef PULLDOWN_TEST
1889 	/* this is assumed to be safe. */
1890 	icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1891 #else
1892 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1893 	if (icmp6 == NULL) {
1894 		/* m is already reclaimed */
1895 		return IPPROTO_DONE;
1896 	}
1897 #endif
1898 
1899 	bzero(&rip6src, sizeof(rip6src));
1900 	rip6src.sin6_len = sizeof(struct sockaddr_in6);
1901 	rip6src.sin6_family = AF_INET6;
1902 	/* KAME hack: recover scopeid */
1903 	(void)in6_recoverscope(&rip6src, &ip6->ip6_src, m->m_pkthdr.rcvif);
1904 
1905 	LIST_FOREACH(in6p, &ripcb, inp_list)
1906 	{
1907 		if ((in6p->inp_vflag & INP_IPV6) == 0)
1908 			continue;
1909 #ifdef HAVE_NRL_INPCB
1910 		if (!(in6p->in6p_flags & INP_IPV6))
1911 			continue;
1912 #endif
1913 		if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6)
1914 			continue;
1915 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1916 		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1917 			continue;
1918 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1919 		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1920 			continue;
1921 		if (in6p->in6p_icmp6filt
1922 		    && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1923 				 in6p->in6p_icmp6filt))
1924 			continue;
1925 		if (last) {
1926 			struct	mbuf *n;
1927 			if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
1928 				if (last->in6p_flags & IN6P_CONTROLOPTS)
1929 					ip6_savecontrol(last, &opts, ip6, n);
1930 				/* strip intermediate headers */
1931 				m_adj(n, off);
1932 				if (sbappendaddr(&last->in6p_socket->so_rcv,
1933 						 (struct sockaddr *)&rip6src,
1934 						 n, opts) == 0) {
1935 					/* should notify about lost packet */
1936 					m_freem(n);
1937 					if (opts) {
1938 						m_freem(opts);
1939 					}
1940 				} else
1941 					sorwakeup(last->in6p_socket);
1942 				opts = NULL;
1943 			}
1944 		}
1945 		last = in6p;
1946 	}
1947 	if (last) {
1948 		if (last->in6p_flags & IN6P_CONTROLOPTS)
1949 			ip6_savecontrol(last, &opts, ip6, m);
1950 		/* strip intermediate headers */
1951 		m_adj(m, off);
1952 		if (sbappendaddr(&last->in6p_socket->so_rcv,
1953 				 (struct sockaddr *)&rip6src, m, opts) == 0) {
1954 			m_freem(m);
1955 			if (opts)
1956 				m_freem(opts);
1957 		} else
1958 			sorwakeup(last->in6p_socket);
1959 	} else {
1960 		m_freem(m);
1961 		ip6stat.ip6s_delivered--;
1962 	}
1963 	return IPPROTO_DONE;
1964 }
1965 
1966 /*
1967  * Reflect the ip6 packet back to the source.
1968  * OFF points to the icmp6 header, counted from the top of the mbuf.
1969  */
1970 void
1971 icmp6_reflect(m, off)
1972 	struct	mbuf *m;
1973 	size_t off;
1974 {
1975 	struct ip6_hdr *ip6;
1976 	struct icmp6_hdr *icmp6;
1977 	struct in6_ifaddr *ia;
1978 	struct in6_addr t, *src = 0;
1979 	int plen;
1980 	int type, code;
1981 	struct ifnet *outif = NULL;
1982 	struct sockaddr_in6 sa6_src, sa6_dst;
1983 #ifdef COMPAT_RFC1885
1984 	int mtu = IPV6_MMTU;
1985 	struct sockaddr_in6 *sin6 = &icmp6_reflect_rt.ro_dst;
1986 #endif
1987 
1988 	/* too short to reflect */
1989 	if (off < sizeof(struct ip6_hdr)) {
1990 		nd6log((LOG_DEBUG,
1991 		    "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
1992 		    (u_long)off, (u_long)sizeof(struct ip6_hdr),
1993 		    __FILE__, __LINE__));
1994 		goto bad;
1995 	}
1996 
1997 	/*
1998 	 * If there are extra headers between IPv6 and ICMPv6, strip
1999 	 * off that header first.
2000 	 */
2001 #ifdef DIAGNOSTIC
2002 	if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2003 		panic("assumption failed in icmp6_reflect");
2004 #endif
2005 	if (off > sizeof(struct ip6_hdr)) {
2006 		size_t l;
2007 		struct ip6_hdr nip6;
2008 
2009 		l = off - sizeof(struct ip6_hdr);
2010 		m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2011 		m_adj(m, l);
2012 		l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2013 		if (m->m_len < l) {
2014 			if ((m = m_pullup(m, l)) == NULL)
2015 				return;
2016 		}
2017 		bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2018 	} else /* off == sizeof(struct ip6_hdr) */ {
2019 		size_t l;
2020 		l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2021 		if (m->m_len < l) {
2022 			if ((m = m_pullup(m, l)) == NULL)
2023 				return;
2024 		}
2025 	}
2026 	plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2027 	ip6 = mtod(m, struct ip6_hdr *);
2028 	ip6->ip6_nxt = IPPROTO_ICMPV6;
2029 	icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2030 	type = icmp6->icmp6_type; /* keep type for statistics */
2031 	code = icmp6->icmp6_code; /* ditto. */
2032 
2033 	t = ip6->ip6_dst;
2034 	/*
2035 	 * ip6_input() drops a packet if its src is multicast.
2036 	 * So, the src is never multicast.
2037 	 */
2038 	ip6->ip6_dst = ip6->ip6_src;
2039 
2040 	/*
2041 	 * XXX: make sure to embed scope zone information, using
2042 	 * already embedded IDs or the received interface (if any).
2043 	 * Note that rcvif may be NULL.
2044 	 * TODO: scoped routing case (XXX).
2045 	 */
2046 	bzero(&sa6_src, sizeof(sa6_src));
2047 	sa6_src.sin6_family = AF_INET6;
2048 	sa6_src.sin6_len = sizeof(sa6_src);
2049 	sa6_src.sin6_addr = ip6->ip6_dst;
2050 	in6_recoverscope(&sa6_src, &ip6->ip6_dst, m->m_pkthdr.rcvif);
2051 	in6_embedscope(&ip6->ip6_dst, &sa6_src, NULL, NULL);
2052 	bzero(&sa6_dst, sizeof(sa6_dst));
2053 	sa6_dst.sin6_family = AF_INET6;
2054 	sa6_dst.sin6_len = sizeof(sa6_dst);
2055 	sa6_dst.sin6_addr = t;
2056 	in6_recoverscope(&sa6_dst, &t, m->m_pkthdr.rcvif);
2057 	in6_embedscope(&t, &sa6_dst, NULL, NULL);
2058 
2059 #ifdef COMPAT_RFC1885
2060 	/*
2061 	 * xxx guess MTU
2062 	 * RFC 1885 requires that echo reply should be truncated if it
2063 	 * does not fit in with (return) path MTU, but the description was
2064 	 * removed in the new spec.
2065 	 */
2066 	if (icmp6_reflect_rt.ro_rt == 0 ||
2067 	    ! (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &ip6->ip6_dst))) {
2068 		if (icmp6_reflect_rt.ro_rt) {
2069 			RTFREE(icmp6_reflect_rt.ro_rt);
2070 			icmp6_reflect_rt.ro_rt = 0;
2071 		}
2072 		bzero(sin6, sizeof(*sin6));
2073 		sin6->sin6_family = PF_INET6;
2074 		sin6->sin6_len = sizeof(struct sockaddr_in6);
2075 		sin6->sin6_addr = ip6->ip6_dst;
2076 
2077 		rtalloc_ign((struct route *)&icmp6_reflect_rt.ro_rt,
2078 			    RTF_PRCLONING);
2079 	}
2080 
2081 	if (icmp6_reflect_rt.ro_rt == 0)
2082 		goto bad;
2083 
2084 	if ((icmp6_reflect_rt.ro_rt->rt_flags & RTF_HOST)
2085 	    && mtu < icmp6_reflect_rt.ro_rt->rt_ifp->if_mtu)
2086 		mtu = icmp6_reflect_rt.ro_rt->rt_rmx.rmx_mtu;
2087 
2088 	if (mtu < m->m_pkthdr.len) {
2089 		plen -= (m->m_pkthdr.len - mtu);
2090 		m_adj(m, mtu - m->m_pkthdr.len);
2091 	}
2092 #endif
2093 	/*
2094 	 * If the incoming packet was addressed directly to us(i.e. unicast),
2095 	 * use dst as the src for the reply.
2096 	 * The IN6_IFF_NOTREADY case would be VERY rare, but is possible
2097 	 * (for example) when we encounter an error while forwarding procedure
2098 	 * destined to a duplicated address of ours.
2099 	 */
2100 	for (ia = in6_ifaddr; ia; ia = ia->ia_next)
2101 		if (IN6_ARE_ADDR_EQUAL(&t, &ia->ia_addr.sin6_addr) &&
2102 		    (ia->ia6_flags & (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) {
2103 			src = &t;
2104 			break;
2105 		}
2106 	if (ia == NULL && IN6_IS_ADDR_LINKLOCAL(&t) && (m->m_flags & M_LOOP)) {
2107 		/*
2108 		 * This is the case if the dst is our link-local address
2109 		 * and the sender is also ourseleves.
2110 		 */
2111 		src = &t;
2112 	}
2113 
2114 	if (src == 0) {
2115 		int e;
2116 		struct route_in6 ro;
2117 
2118 		/*
2119 		 * This case matches to multicasts, our anycast, or unicasts
2120 		 * that we do not own. Select a source address based on the
2121 		 * source address of the erroneous packet.
2122 		 */
2123 		bzero(&ro, sizeof(ro));
2124 		src = in6_selectsrc(&sa6_src, NULL, NULL, &ro, NULL, &e);
2125 		if (ro.ro_rt)
2126 			RTFREE(ro.ro_rt); /* XXX: we could use this */
2127 		if (src == NULL) {
2128 			nd6log((LOG_DEBUG,
2129 			    "icmp6_reflect: source can't be determined: "
2130 			    "dst=%s, error=%d\n",
2131 			    ip6_sprintf(&sa6_src.sin6_addr), e));
2132 			goto bad;
2133 		}
2134 	}
2135 
2136 	ip6->ip6_src = *src;
2137 
2138 	ip6->ip6_flow = 0;
2139 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2140 	ip6->ip6_vfc |= IPV6_VERSION;
2141 	ip6->ip6_nxt = IPPROTO_ICMPV6;
2142 	if (m->m_pkthdr.rcvif) {
2143 		/* XXX: This may not be the outgoing interface */
2144 		ip6->ip6_hlim = nd_ifinfo[m->m_pkthdr.rcvif->if_index].chlim;
2145 	} else
2146 		ip6->ip6_hlim = ip6_defhlim;
2147 
2148 	icmp6->icmp6_cksum = 0;
2149 	icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2150 					sizeof(struct ip6_hdr), plen);
2151 
2152 	/*
2153 	 * XXX option handling
2154 	 */
2155 
2156 	m->m_flags &= ~(M_BCAST|M_MCAST);
2157 #ifdef IPSEC
2158 	/* Don't lookup socket */
2159 	(void)ipsec_setsocket(m, NULL);
2160 #endif /*IPSEC*/
2161 
2162 #ifdef COMPAT_RFC1885
2163 	ip6_output(m, NULL, &icmp6_reflect_rt, 0, NULL, &outif);
2164 #else
2165 	ip6_output(m, NULL, NULL, 0, NULL, &outif);
2166 #endif
2167 	if (outif)
2168 		icmp6_ifoutstat_inc(outif, type, code);
2169 
2170 	return;
2171 
2172  bad:
2173 	m_freem(m);
2174 	return;
2175 }
2176 
2177 void
2178 icmp6_fasttimo()
2179 {
2180 
2181 	mld6_fasttimeo();
2182 }
2183 
2184 static const char *
2185 icmp6_redirect_diag(src6, dst6, tgt6)
2186 	struct in6_addr *src6;
2187 	struct in6_addr *dst6;
2188 	struct in6_addr *tgt6;
2189 {
2190 	static char buf[1024];
2191 	snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2192 		ip6_sprintf(src6), ip6_sprintf(dst6), ip6_sprintf(tgt6));
2193 	return buf;
2194 }
2195 
2196 void
2197 icmp6_redirect_input(m, off)
2198 	struct mbuf *m;
2199 	int off;
2200 {
2201 	struct ifnet *ifp = m->m_pkthdr.rcvif;
2202 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2203 	struct nd_redirect *nd_rd;
2204 	int icmp6len = ntohs(ip6->ip6_plen);
2205 	char *lladdr = NULL;
2206 	int lladdrlen = 0;
2207 	u_char *redirhdr = NULL;
2208 	int redirhdrlen = 0;
2209 	struct rtentry *rt = NULL;
2210 	int is_router;
2211 	int is_onlink;
2212 	struct in6_addr src6 = ip6->ip6_src;
2213 	struct in6_addr redtgt6;
2214 	struct in6_addr reddst6;
2215 	union nd_opts ndopts;
2216 
2217 	if (!m || !ifp)
2218 		return;
2219 
2220 	/* XXX if we are router, we don't update route by icmp6 redirect */
2221 	if (ip6_forwarding)
2222 		goto freeit;
2223 	if (!icmp6_rediraccept)
2224 		goto freeit;
2225 
2226 #ifndef PULLDOWN_TEST
2227 	IP6_EXTHDR_CHECK(m, off, icmp6len,);
2228 	nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2229 #else
2230 	IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2231 	if (nd_rd == NULL) {
2232 		icmp6stat.icp6s_tooshort++;
2233 		return;
2234 	}
2235 #endif
2236 	redtgt6 = nd_rd->nd_rd_target;
2237 	reddst6 = nd_rd->nd_rd_dst;
2238 
2239 	if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2240 		redtgt6.s6_addr16[1] = htons(ifp->if_index);
2241 	if (IN6_IS_ADDR_LINKLOCAL(&reddst6))
2242 		reddst6.s6_addr16[1] = htons(ifp->if_index);
2243 
2244 	/* validation */
2245 	if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2246 		nd6log((LOG_ERR,
2247 			"ICMP6 redirect sent from %s rejected; "
2248 			"must be from linklocal\n", ip6_sprintf(&src6)));
2249 		goto bad;
2250 	}
2251 	if (ip6->ip6_hlim != 255) {
2252 		nd6log((LOG_ERR,
2253 			"ICMP6 redirect sent from %s rejected; "
2254 			"hlim=%d (must be 255)\n",
2255 			ip6_sprintf(&src6), ip6->ip6_hlim));
2256 		goto bad;
2257 	}
2258     {
2259 	/* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2260 	struct sockaddr_in6 sin6;
2261 	struct in6_addr *gw6;
2262 
2263 	bzero(&sin6, sizeof(sin6));
2264 	sin6.sin6_family = AF_INET6;
2265 	sin6.sin6_len = sizeof(struct sockaddr_in6);
2266 	bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
2267 	rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
2268 	if (rt) {
2269 		if (rt->rt_gateway == NULL ||
2270 		    rt->rt_gateway->sa_family != AF_INET6) {
2271 			nd6log((LOG_ERR,
2272 			    "ICMP6 redirect rejected; no route "
2273 			    "with inet6 gateway found for redirect dst: %s\n",
2274 			    icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2275 			RTFREE(rt);
2276 			goto bad;
2277 		}
2278 
2279 		gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2280 		if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2281 			nd6log((LOG_ERR,
2282 				"ICMP6 redirect rejected; "
2283 				"not equal to gw-for-src=%s (must be same): "
2284 				"%s\n",
2285 				ip6_sprintf(gw6),
2286 				icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2287 			RTFREE(rt);
2288 			goto bad;
2289 		}
2290 	} else {
2291 		nd6log((LOG_ERR,
2292 			"ICMP6 redirect rejected; "
2293 			"no route found for redirect dst: %s\n",
2294 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2295 		goto bad;
2296 	}
2297 	RTFREE(rt);
2298 	rt = NULL;
2299     }
2300 	if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2301 		nd6log((LOG_ERR,
2302 			"ICMP6 redirect rejected; "
2303 			"redirect dst must be unicast: %s\n",
2304 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2305 		goto bad;
2306 	}
2307 
2308 	is_router = is_onlink = 0;
2309 	if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2310 		is_router = 1;	/* router case */
2311 	if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2312 		is_onlink = 1;	/* on-link destination case */
2313 	if (!is_router && !is_onlink) {
2314 		nd6log((LOG_ERR,
2315 			"ICMP6 redirect rejected; "
2316 			"neither router case nor onlink case: %s\n",
2317 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2318 		goto bad;
2319 	}
2320 	/* validation passed */
2321 
2322 	icmp6len -= sizeof(*nd_rd);
2323 	nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2324 	if (nd6_options(&ndopts) < 0) {
2325 		nd6log((LOG_INFO, "icmp6_redirect_input: "
2326 			"invalid ND option, rejected: %s\n",
2327 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2328 		/* nd6_options have incremented stats */
2329 		goto freeit;
2330 	}
2331 
2332 	if (ndopts.nd_opts_tgt_lladdr) {
2333 		lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2334 		lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2335 	}
2336 
2337 	if (ndopts.nd_opts_rh) {
2338 		redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
2339 		redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
2340 	}
2341 
2342 	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2343 		nd6log((LOG_INFO,
2344 			"icmp6_redirect_input: lladdrlen mismatch for %s "
2345 			"(if %d, icmp6 packet %d): %s\n",
2346 			ip6_sprintf(&redtgt6), ifp->if_addrlen, lladdrlen - 2,
2347 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2348 		goto bad;
2349 	}
2350 
2351 	/* RFC 2461 8.3 */
2352 	nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2353 			 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2354 
2355 	if (!is_onlink) {	/* better router case. perform rtredirect. */
2356 		/* perform rtredirect */
2357 		struct sockaddr_in6 sdst;
2358 		struct sockaddr_in6 sgw;
2359 		struct sockaddr_in6 ssrc;
2360 
2361 		bzero(&sdst, sizeof(sdst));
2362 		bzero(&sgw, sizeof(sgw));
2363 		bzero(&ssrc, sizeof(ssrc));
2364 		sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2365 		sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2366 			sizeof(struct sockaddr_in6);
2367 		bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2368 		bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2369 		bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2370 		rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2371 			   (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
2372 			   (struct sockaddr *)&ssrc,
2373 			   (struct rtentry **)NULL);
2374 	}
2375 	/* finally update cached route in each socket via pfctlinput */
2376     {
2377 	struct sockaddr_in6 sdst;
2378 
2379 	bzero(&sdst, sizeof(sdst));
2380 	sdst.sin6_family = AF_INET6;
2381 	sdst.sin6_len = sizeof(struct sockaddr_in6);
2382 	bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2383 	pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2384 #ifdef IPSEC
2385 	key_sa_routechange((struct sockaddr *)&sdst);
2386 #endif
2387     }
2388 
2389  freeit:
2390 	m_freem(m);
2391 	return;
2392 
2393  bad:
2394 	icmp6stat.icp6s_badredirect++;
2395 	m_freem(m);
2396 }
2397 
2398 void
2399 icmp6_redirect_output(m0, rt)
2400 	struct mbuf *m0;
2401 	struct rtentry *rt;
2402 {
2403 	struct ifnet *ifp;	/* my outgoing interface */
2404 	struct in6_addr *ifp_ll6;
2405 	struct in6_addr *router_ll6;
2406 	struct ip6_hdr *sip6;	/* m0 as struct ip6_hdr */
2407 	struct mbuf *m = NULL;	/* newly allocated one */
2408 	struct ip6_hdr *ip6;	/* m as struct ip6_hdr */
2409 	struct nd_redirect *nd_rd;
2410 	size_t maxlen;
2411 	u_char *p;
2412 	struct ifnet *outif = NULL;
2413 	struct sockaddr_in6 src_sa;
2414 
2415 	icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
2416 
2417 	/* if we are not router, we don't send icmp6 redirect */
2418 	if (!ip6_forwarding || ip6_accept_rtadv)
2419 		goto fail;
2420 
2421 	/* sanity check */
2422 	if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2423 		goto fail;
2424 
2425 	/*
2426 	 * Address check:
2427 	 *  the source address must identify a neighbor, and
2428 	 *  the destination address must not be a multicast address
2429 	 *  [RFC 2461, sec 8.2]
2430 	 */
2431 	sip6 = mtod(m0, struct ip6_hdr *);
2432 	bzero(&src_sa, sizeof(src_sa));
2433 	src_sa.sin6_family = AF_INET6;
2434 	src_sa.sin6_len = sizeof(src_sa);
2435 	src_sa.sin6_addr = sip6->ip6_src;
2436 	/* we don't currently use sin6_scope_id, but eventually use it */
2437 	src_sa.sin6_scope_id = in6_addr2scopeid(ifp, &sip6->ip6_src);
2438 	if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2439 		goto fail;
2440 	if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2441 		goto fail;	/* what should we do here? */
2442 
2443 	/* rate limit */
2444 	if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2445 		goto fail;
2446 
2447 	/*
2448 	 * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2449 	 * we almost always ask for an mbuf cluster for simplicity.
2450 	 * (MHLEN < IPV6_MMTU is almost always true)
2451 	 */
2452 #if IPV6_MMTU >= MCLBYTES
2453 # error assumption failed about IPV6_MMTU and MCLBYTES
2454 #endif
2455 	MGETHDR(m, M_DONTWAIT, MT_HEADER);
2456 	if (m && IPV6_MMTU >= MHLEN)
2457 		MCLGET(m, M_DONTWAIT);
2458 	if (!m)
2459 		goto fail;
2460 	m->m_pkthdr.rcvif = NULL;
2461 	m->m_len = 0;
2462 	maxlen = M_TRAILINGSPACE(m);
2463 	maxlen = min(IPV6_MMTU, maxlen);
2464 	/* just for safety */
2465 	if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2466 	    ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2467 		goto fail;
2468 	}
2469 
2470 	{
2471 		/* get ip6 linklocal address for ifp(my outgoing interface). */
2472 		struct in6_ifaddr *ia;
2473 		if ((ia = in6ifa_ifpforlinklocal(ifp,
2474 						 IN6_IFF_NOTREADY|
2475 						 IN6_IFF_ANYCAST)) == NULL)
2476 			goto fail;
2477 		ifp_ll6 = &ia->ia_addr.sin6_addr;
2478 	}
2479 
2480 	/* get ip6 linklocal address for the router. */
2481 	if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2482 		struct sockaddr_in6 *sin6;
2483 		sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2484 		router_ll6 = &sin6->sin6_addr;
2485 		if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2486 			router_ll6 = (struct in6_addr *)NULL;
2487 	} else
2488 		router_ll6 = (struct in6_addr *)NULL;
2489 
2490 	/* ip6 */
2491 	ip6 = mtod(m, struct ip6_hdr *);
2492 	ip6->ip6_flow = 0;
2493 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2494 	ip6->ip6_vfc |= IPV6_VERSION;
2495 	/* ip6->ip6_plen will be set later */
2496 	ip6->ip6_nxt = IPPROTO_ICMPV6;
2497 	ip6->ip6_hlim = 255;
2498 	/* ip6->ip6_src must be linklocal addr for my outgoing if. */
2499 	bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2500 	bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2501 
2502 	/* ND Redirect */
2503 	nd_rd = (struct nd_redirect *)(ip6 + 1);
2504 	nd_rd->nd_rd_type = ND_REDIRECT;
2505 	nd_rd->nd_rd_code = 0;
2506 	nd_rd->nd_rd_reserved = 0;
2507 	if (rt->rt_flags & RTF_GATEWAY) {
2508 		/*
2509 		 * nd_rd->nd_rd_target must be a link-local address in
2510 		 * better router cases.
2511 		 */
2512 		if (!router_ll6)
2513 			goto fail;
2514 		bcopy(router_ll6, &nd_rd->nd_rd_target,
2515 		      sizeof(nd_rd->nd_rd_target));
2516 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2517 		      sizeof(nd_rd->nd_rd_dst));
2518 	} else {
2519 		/* make sure redtgt == reddst */
2520 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2521 		      sizeof(nd_rd->nd_rd_target));
2522 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2523 		      sizeof(nd_rd->nd_rd_dst));
2524 	}
2525 
2526 	p = (u_char *)(nd_rd + 1);
2527 
2528 	if (!router_ll6)
2529 		goto nolladdropt;
2530 
2531     {
2532 	/* target lladdr option */
2533 	struct rtentry *rt_router = NULL;
2534 	int len;
2535 	struct sockaddr_dl *sdl;
2536 	struct nd_opt_hdr *nd_opt;
2537 	char *lladdr;
2538 
2539 	rt_router = nd6_lookup(router_ll6, 0, ifp);
2540 	if (!rt_router)
2541 		goto nolladdropt;
2542 	len = sizeof(*nd_opt) + ifp->if_addrlen;
2543 	len = (len + 7) & ~7;	/*round by 8*/
2544 	/* safety check */
2545 	if (len + (p - (u_char *)ip6) > maxlen)
2546 		goto nolladdropt;
2547 	if (!(rt_router->rt_flags & RTF_GATEWAY) &&
2548 	    (rt_router->rt_flags & RTF_LLINFO) &&
2549 	    (rt_router->rt_gateway->sa_family == AF_LINK) &&
2550 	    (sdl = (struct sockaddr_dl *)rt_router->rt_gateway) &&
2551 	    sdl->sdl_alen) {
2552 		nd_opt = (struct nd_opt_hdr *)p;
2553 		nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2554 		nd_opt->nd_opt_len = len >> 3;
2555 		lladdr = (char *)(nd_opt + 1);
2556 		bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen);
2557 		p += len;
2558 	}
2559     }
2560 nolladdropt:;
2561 
2562 	m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2563 
2564 	/* just to be safe */
2565 #ifdef M_DECRYPTED	/*not openbsd*/
2566 	if (m0->m_flags & M_DECRYPTED)
2567 		goto noredhdropt;
2568 #endif
2569 	if (p - (u_char *)ip6 > maxlen)
2570 		goto noredhdropt;
2571 
2572     {
2573 	/* redirected header option */
2574 	int len;
2575 	struct nd_opt_rd_hdr *nd_opt_rh;
2576 
2577 	/*
2578 	 * compute the maximum size for icmp6 redirect header option.
2579 	 * XXX room for auth header?
2580 	 */
2581 	len = maxlen - (p - (u_char *)ip6);
2582 	len &= ~7;
2583 
2584 	/* This is just for simplicity. */
2585 	if (m0->m_pkthdr.len != m0->m_len) {
2586 		if (m0->m_next) {
2587 			m_freem(m0->m_next);
2588 			m0->m_next = NULL;
2589 		}
2590 		m0->m_pkthdr.len = m0->m_len;
2591 	}
2592 
2593 	/*
2594 	 * Redirected header option spec (RFC2461 4.6.3) talks nothing
2595 	 * about padding/truncate rule for the original IP packet.
2596 	 * From the discussion on IPv6imp in Feb 1999, the consensus was:
2597 	 * - "attach as much as possible" is the goal
2598 	 * - pad if not aligned (original size can be guessed by original
2599 	 *   ip6 header)
2600 	 * Following code adds the padding if it is simple enough,
2601 	 * and truncates if not.
2602 	 */
2603 	if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2604 		panic("assumption failed in %s:%d\n", __FILE__, __LINE__);
2605 
2606 	if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2607 		/* not enough room, truncate */
2608 		m0->m_pkthdr.len = m0->m_len = len - sizeof(*nd_opt_rh);
2609 	} else {
2610 		/* enough room, pad or truncate */
2611 		size_t extra;
2612 
2613 		extra = m0->m_pkthdr.len % 8;
2614 		if (extra) {
2615 			/* pad if easy enough, truncate if not */
2616 			if (8 - extra <= M_TRAILINGSPACE(m0)) {
2617 				/* pad */
2618 				m0->m_len += (8 - extra);
2619 				m0->m_pkthdr.len += (8 - extra);
2620 			} else {
2621 				/* truncate */
2622 				m0->m_pkthdr.len -= extra;
2623 				m0->m_len -= extra;
2624 			}
2625 		}
2626 		len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2627 		m0->m_pkthdr.len = m0->m_len = len - sizeof(*nd_opt_rh);
2628 	}
2629 
2630 	nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2631 	bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2632 	nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2633 	nd_opt_rh->nd_opt_rh_len = len >> 3;
2634 	p += sizeof(*nd_opt_rh);
2635 	m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2636 
2637 	/* connect m0 to m */
2638 	m->m_next = m0;
2639 	m->m_pkthdr.len = m->m_len + m0->m_len;
2640     }
2641 noredhdropt:;
2642 
2643 	if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_src))
2644 		sip6->ip6_src.s6_addr16[1] = 0;
2645 	if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_dst))
2646 		sip6->ip6_dst.s6_addr16[1] = 0;
2647 #if 0
2648 	if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
2649 		ip6->ip6_src.s6_addr16[1] = 0;
2650 	if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
2651 		ip6->ip6_dst.s6_addr16[1] = 0;
2652 #endif
2653 	if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_target))
2654 		nd_rd->nd_rd_target.s6_addr16[1] = 0;
2655 	if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_dst))
2656 		nd_rd->nd_rd_dst.s6_addr16[1] = 0;
2657 
2658 	ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2659 
2660 	nd_rd->nd_rd_cksum = 0;
2661 	nd_rd->nd_rd_cksum
2662 		= in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), ntohs(ip6->ip6_plen));
2663 
2664 	/* send the packet to outside... */
2665 #ifdef IPSEC
2666 	/* Don't lookup socket */
2667 	(void)ipsec_setsocket(m, NULL);
2668 #endif /*IPSEC*/
2669 	ip6_output(m, NULL, NULL, 0, NULL, &outif);
2670 	if (outif) {
2671 		icmp6_ifstat_inc(outif, ifs6_out_msg);
2672 		icmp6_ifstat_inc(outif, ifs6_out_redirect);
2673 	}
2674 	icmp6stat.icp6s_outhist[ND_REDIRECT]++;
2675 
2676 	return;
2677 
2678 fail:
2679 	if (m)
2680 		m_freem(m);
2681 	if (m0)
2682 		m_freem(m0);
2683 }
2684 
2685 #ifdef HAVE_NRL_INPCB
2686 #define sotoin6pcb	sotoinpcb
2687 #define in6pcb		inpcb
2688 #define in6p_icmp6filt	inp_icmp6filt
2689 #endif
2690 /*
2691  * ICMPv6 socket option processing.
2692  */
2693 int
2694 icmp6_ctloutput(so, sopt)
2695 	struct socket *so;
2696 	struct sockopt *sopt;
2697 {
2698 	int error = 0;
2699 	int optlen;
2700 	struct inpcb *inp = sotoinpcb(so);
2701 	int level, op, optname;
2702 
2703 	if (sopt) {
2704 		level = sopt->sopt_level;
2705 		op = sopt->sopt_dir;
2706 		optname = sopt->sopt_name;
2707 		optlen = sopt->sopt_valsize;
2708 	} else
2709 		level = op = optname = optlen = 0;
2710 
2711 	if (level != IPPROTO_ICMPV6) {
2712 		return EINVAL;
2713 	}
2714 
2715 	switch (op) {
2716 	case PRCO_SETOPT:
2717 		switch (optname) {
2718 		case ICMP6_FILTER:
2719 		    {
2720 			struct icmp6_filter *p;
2721 
2722 			if (optlen != sizeof(*p)) {
2723 				error = EMSGSIZE;
2724 				break;
2725 			}
2726 			if (inp->in6p_icmp6filt == NULL) {
2727 				error = EINVAL;
2728 				break;
2729 			}
2730 			error = sooptcopyin(sopt, inp->in6p_icmp6filt, optlen,
2731 				optlen);
2732 			break;
2733 		    }
2734 
2735 		default:
2736 			error = ENOPROTOOPT;
2737 			break;
2738 		}
2739 		break;
2740 
2741 	case PRCO_GETOPT:
2742 		switch (optname) {
2743 		case ICMP6_FILTER:
2744 		    {
2745 			if (inp->in6p_icmp6filt == NULL) {
2746 				error = EINVAL;
2747 				break;
2748 			}
2749 			error = sooptcopyout(sopt, inp->in6p_icmp6filt,
2750 				sizeof(struct icmp6_filter));
2751 			break;
2752 		    }
2753 
2754 		default:
2755 			error = ENOPROTOOPT;
2756 			break;
2757 		}
2758 		break;
2759 	}
2760 
2761 	return(error);
2762 }
2763 #ifdef HAVE_NRL_INPCB
2764 #undef sotoin6pcb
2765 #undef in6pcb
2766 #undef in6p_icmp6filt
2767 #endif
2768 
2769 #ifndef HAVE_PPSRATECHECK
2770 #ifndef timersub
2771 #define	timersub(tvp, uvp, vvp)						\
2772 	do {								\
2773 		(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
2774 		(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
2775 		if ((vvp)->tv_usec < 0) {				\
2776 			(vvp)->tv_sec--;				\
2777 			(vvp)->tv_usec += 1000000;			\
2778 		}							\
2779 	} while (0)
2780 #endif
2781 
2782 /*
2783  * ppsratecheck(): packets (or events) per second limitation.
2784  */
2785 static int
2786 ppsratecheck(lasttime, curpps, maxpps)
2787 	struct timeval *lasttime;
2788 	int *curpps;
2789 	int maxpps;	/* maximum pps allowed */
2790 {
2791 	struct timeval tv, delta;
2792 	int s, rv;
2793 
2794 	s = splclock();
2795 	microtime(&tv);
2796 	splx(s);
2797 
2798 	timersub(&tv, lasttime, &delta);
2799 
2800 	/*
2801 	 * check for 0,0 is so that the message will be seen at least once.
2802 	 * if more than one second have passed since the last update of
2803 	 * lasttime, reset the counter.
2804 	 *
2805 	 * we do increment *curpps even in *curpps < maxpps case, as some may
2806 	 * try to use *curpps for stat purposes as well.
2807 	 */
2808 	if ((lasttime->tv_sec == 0 && lasttime->tv_usec == 0) ||
2809 	    delta.tv_sec >= 1) {
2810 		*lasttime = tv;
2811 		*curpps = 0;
2812 		rv = 1;
2813 	} else if (maxpps < 0)
2814 		rv = 1;
2815 	else if (*curpps < maxpps)
2816 		rv = 1;
2817 	else
2818 		rv = 0;
2819 
2820 #if 1 /*DIAGNOSTIC?*/
2821 	/* be careful about wrap-around */
2822 	if (*curpps + 1 > *curpps)
2823 		*curpps = *curpps + 1;
2824 #else
2825 	/*
2826 	 * assume that there's not too many calls to this function.
2827 	 * not sure if the assumption holds, as it depends on *caller's*
2828 	 * behavior, not the behavior of this function.
2829 	 * IMHO it is wrong to make assumption on the caller's behavior,
2830 	 * so the above #if is #if 1, not #ifdef DIAGNOSTIC.
2831 	 */
2832 	*curpps = *curpps + 1;
2833 #endif
2834 
2835 	return (rv);
2836 }
2837 #endif
2838 
2839 /*
2840  * Perform rate limit check.
2841  * Returns 0 if it is okay to send the icmp6 packet.
2842  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2843  * limitation.
2844  *
2845  * XXX per-destination/type check necessary?
2846  */
2847 static int
2848 icmp6_ratelimit(dst, type, code)
2849 	const struct in6_addr *dst;	/* not used at this moment */
2850 	const int type;			/* not used at this moment */
2851 	const int code;			/* not used at this moment */
2852 {
2853 	int ret;
2854 
2855 	ret = 0;	/*okay to send*/
2856 
2857 	/* PPS limit */
2858 	if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count,
2859 	    icmp6errppslim)) {
2860 		/* The packet is subject to rate limit */
2861 		ret++;
2862 	}
2863 
2864 	return ret;
2865 }
2866