xref: /netbsd-src/sys/netinet6/nd6.c (revision e39ef1d61eee3ccba837ee281f1e098c864487aa)
1 /*	$NetBSD: nd6.c,v 1.139 2011/12/19 11:59:58 drochner Exp $	*/
2 /*	$KAME: nd6.c,v 1.279 2002/06/08 11:16:51 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 #include <sys/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: nd6.c,v 1.139 2011/12/19 11:59:58 drochner Exp $");
35 
36 #include "opt_ipsec.h"
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/callout.h>
41 #include <sys/malloc.h>
42 #include <sys/mbuf.h>
43 #include <sys/socket.h>
44 #include <sys/socketvar.h>
45 #include <sys/sockio.h>
46 #include <sys/time.h>
47 #include <sys/kernel.h>
48 #include <sys/protosw.h>
49 #include <sys/errno.h>
50 #include <sys/ioctl.h>
51 #include <sys/syslog.h>
52 #include <sys/queue.h>
53 #include <sys/cprng.h>
54 
55 #include <net/if.h>
56 #include <net/if_dl.h>
57 #include <net/if_types.h>
58 #include <net/route.h>
59 #include <net/if_ether.h>
60 #include <net/if_fddi.h>
61 #include <net/if_arc.h>
62 
63 #include <netinet/in.h>
64 #include <netinet6/in6_var.h>
65 #include <netinet/ip6.h>
66 #include <netinet6/ip6_var.h>
67 #include <netinet6/scope6_var.h>
68 #include <netinet6/nd6.h>
69 #include <netinet/icmp6.h>
70 #include <netinet6/icmp6_private.h>
71 
72 #ifdef KAME_IPSEC
73 #include <netinet6/ipsec.h>
74 #endif
75 
76 #include <net/net_osdep.h>
77 
78 #define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */
79 #define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */
80 
81 /* timer values */
82 int	nd6_prune	= 1;	/* walk list every 1 seconds */
83 int	nd6_delay	= 5;	/* delay first probe time 5 second */
84 int	nd6_umaxtries	= 3;	/* maximum unicast query */
85 int	nd6_mmaxtries	= 3;	/* maximum multicast query */
86 int	nd6_useloopback = 1;	/* use loopback interface for local traffic */
87 int	nd6_gctimer	= (60 * 60 * 24); /* 1 day: garbage collection timer */
88 
89 /* preventing too many loops in ND option parsing */
90 int nd6_maxndopt = 10;	/* max # of ND options allowed */
91 
92 int nd6_maxnudhint = 0;	/* max # of subsequent upper layer hints */
93 
94 int nd6_maxqueuelen = 1; /* max # of packets cached in unresolved ND entries */
95 
96 #ifdef ND6_DEBUG
97 int nd6_debug = 1;
98 #else
99 int nd6_debug = 0;
100 #endif
101 
102 /* for debugging? */
103 static int nd6_inuse, nd6_allocated;
104 
105 struct llinfo_nd6 llinfo_nd6 = {
106 	.ln_prev = &llinfo_nd6,
107 	.ln_next = &llinfo_nd6,
108 };
109 struct nd_drhead nd_defrouter;
110 struct nd_prhead nd_prefix = { 0 };
111 
112 int nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL;
113 static const struct sockaddr_in6 all1_sa = {
114 	  .sin6_family = AF_INET6
115 	, .sin6_len = sizeof(struct sockaddr_in6)
116 	, .sin6_addr = {.s6_addr = {0xff, 0xff, 0xff, 0xff,
117 				    0xff, 0xff, 0xff, 0xff,
118 				    0xff, 0xff, 0xff, 0xff,
119 				    0xff, 0xff, 0xff, 0xff}}
120 };
121 
122 static void nd6_setmtu0(struct ifnet *, struct nd_ifinfo *);
123 static void nd6_slowtimo(void *);
124 static int regen_tmpaddr(struct in6_ifaddr *);
125 static struct llinfo_nd6 *nd6_free(struct rtentry *, int);
126 static void nd6_llinfo_timer(void *);
127 static void clear_llinfo_pqueue(struct llinfo_nd6 *);
128 
129 callout_t nd6_slowtimo_ch;
130 callout_t nd6_timer_ch;
131 extern callout_t in6_tmpaddrtimer_ch;
132 
133 static int fill_drlist(void *, size_t *, size_t);
134 static int fill_prlist(void *, size_t *, size_t);
135 
136 MALLOC_DEFINE(M_IP6NDP, "NDP", "IPv6 Neighbour Discovery");
137 
138 void
139 nd6_init(void)
140 {
141 	static int nd6_init_done = 0;
142 
143 	if (nd6_init_done) {
144 		log(LOG_NOTICE, "nd6_init called more than once(ignored)\n");
145 		return;
146 	}
147 
148 	/* initialization of the default router list */
149 	TAILQ_INIT(&nd_defrouter);
150 
151 	nd6_init_done = 1;
152 
153 	callout_init(&nd6_slowtimo_ch, CALLOUT_MPSAFE);
154 	callout_init(&nd6_timer_ch, CALLOUT_MPSAFE);
155 
156 	/* start timer */
157 	callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
158 	    nd6_slowtimo, NULL);
159 }
160 
161 struct nd_ifinfo *
162 nd6_ifattach(struct ifnet *ifp)
163 {
164 	struct nd_ifinfo *nd;
165 
166 	nd = (struct nd_ifinfo *)malloc(sizeof(*nd), M_IP6NDP, M_WAITOK);
167 	memset(nd, 0, sizeof(*nd));
168 
169 	nd->initialized = 1;
170 
171 	nd->chlim = IPV6_DEFHLIM;
172 	nd->basereachable = REACHABLE_TIME;
173 	nd->reachable = ND_COMPUTE_RTIME(nd->basereachable);
174 	nd->retrans = RETRANS_TIMER;
175 	/*
176 	 * Note that the default value of ip6_accept_rtadv is 0.
177 	 * Because we do not set ND6_IFF_OVERRIDE_RTADV here, we won't
178 	 * accept RAs by default.
179 	 */
180 	nd->flags = ND6_IFF_PERFORMNUD | ND6_IFF_ACCEPT_RTADV;
181 
182 	/* XXX: we cannot call nd6_setmtu since ifp is not fully initialized */
183 	nd6_setmtu0(ifp, nd);
184 
185 	return nd;
186 }
187 
188 void
189 nd6_ifdetach(struct nd_ifinfo *nd)
190 {
191 
192 	free(nd, M_IP6NDP);
193 }
194 
195 void
196 nd6_setmtu(struct ifnet *ifp)
197 {
198 	nd6_setmtu0(ifp, ND_IFINFO(ifp));
199 }
200 
201 void
202 nd6_setmtu0(struct ifnet *ifp, struct nd_ifinfo *ndi)
203 {
204 	u_int32_t omaxmtu;
205 
206 	omaxmtu = ndi->maxmtu;
207 
208 	switch (ifp->if_type) {
209 	case IFT_ARCNET:
210 		ndi->maxmtu = MIN(ARC_PHDS_MAXMTU, ifp->if_mtu); /* RFC2497 */
211 		break;
212 	case IFT_FDDI:
213 		ndi->maxmtu = MIN(FDDIIPMTU, ifp->if_mtu);
214 		break;
215 	default:
216 		ndi->maxmtu = ifp->if_mtu;
217 		break;
218 	}
219 
220 	/*
221 	 * Decreasing the interface MTU under IPV6 minimum MTU may cause
222 	 * undesirable situation.  We thus notify the operator of the change
223 	 * explicitly.  The check for omaxmtu is necessary to restrict the
224 	 * log to the case of changing the MTU, not initializing it.
225 	 */
226 	if (omaxmtu >= IPV6_MMTU && ndi->maxmtu < IPV6_MMTU) {
227 		log(LOG_NOTICE, "nd6_setmtu0: new link MTU on %s (%lu) is too"
228 		    " small for IPv6 which needs %lu\n",
229 		    if_name(ifp), (unsigned long)ndi->maxmtu, (unsigned long)
230 		    IPV6_MMTU);
231 	}
232 
233 	if (ndi->maxmtu > in6_maxmtu)
234 		in6_setmaxmtu(); /* check all interfaces just in case */
235 }
236 
237 void
238 nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts)
239 {
240 
241 	memset(ndopts, 0, sizeof(*ndopts));
242 	ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
243 	ndopts->nd_opts_last
244 		= (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len);
245 
246 	if (icmp6len == 0) {
247 		ndopts->nd_opts_done = 1;
248 		ndopts->nd_opts_search = NULL;
249 	}
250 }
251 
252 /*
253  * Take one ND option.
254  */
255 struct nd_opt_hdr *
256 nd6_option(union nd_opts *ndopts)
257 {
258 	struct nd_opt_hdr *nd_opt;
259 	int olen;
260 
261 	if (ndopts == NULL)
262 		panic("ndopts == NULL in nd6_option");
263 	if (ndopts->nd_opts_last == NULL)
264 		panic("uninitialized ndopts in nd6_option");
265 	if (ndopts->nd_opts_search == NULL)
266 		return NULL;
267 	if (ndopts->nd_opts_done)
268 		return NULL;
269 
270 	nd_opt = ndopts->nd_opts_search;
271 
272 	/* make sure nd_opt_len is inside the buffer */
273 	if ((void *)&nd_opt->nd_opt_len >= (void *)ndopts->nd_opts_last) {
274 		memset(ndopts, 0, sizeof(*ndopts));
275 		return NULL;
276 	}
277 
278 	olen = nd_opt->nd_opt_len << 3;
279 	if (olen == 0) {
280 		/*
281 		 * Message validation requires that all included
282 		 * options have a length that is greater than zero.
283 		 */
284 		memset(ndopts, 0, sizeof(*ndopts));
285 		return NULL;
286 	}
287 
288 	ndopts->nd_opts_search = (struct nd_opt_hdr *)((char *)nd_opt + olen);
289 	if (ndopts->nd_opts_search > ndopts->nd_opts_last) {
290 		/* option overruns the end of buffer, invalid */
291 		memset(ndopts, 0, sizeof(*ndopts));
292 		return NULL;
293 	} else if (ndopts->nd_opts_search == ndopts->nd_opts_last) {
294 		/* reached the end of options chain */
295 		ndopts->nd_opts_done = 1;
296 		ndopts->nd_opts_search = NULL;
297 	}
298 	return nd_opt;
299 }
300 
301 /*
302  * Parse multiple ND options.
303  * This function is much easier to use, for ND routines that do not need
304  * multiple options of the same type.
305  */
306 int
307 nd6_options(union nd_opts *ndopts)
308 {
309 	struct nd_opt_hdr *nd_opt;
310 	int i = 0;
311 
312 	if (ndopts == NULL)
313 		panic("ndopts == NULL in nd6_options");
314 	if (ndopts->nd_opts_last == NULL)
315 		panic("uninitialized ndopts in nd6_options");
316 	if (ndopts->nd_opts_search == NULL)
317 		return 0;
318 
319 	while (1) {
320 		nd_opt = nd6_option(ndopts);
321 		if (nd_opt == NULL && ndopts->nd_opts_last == NULL) {
322 			/*
323 			 * Message validation requires that all included
324 			 * options have a length that is greater than zero.
325 			 */
326 			ICMP6_STATINC(ICMP6_STAT_ND_BADOPT);
327 			memset(ndopts, 0, sizeof(*ndopts));
328 			return -1;
329 		}
330 
331 		if (nd_opt == NULL)
332 			goto skip1;
333 
334 		switch (nd_opt->nd_opt_type) {
335 		case ND_OPT_SOURCE_LINKADDR:
336 		case ND_OPT_TARGET_LINKADDR:
337 		case ND_OPT_MTU:
338 		case ND_OPT_REDIRECTED_HEADER:
339 			if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
340 				nd6log((LOG_INFO,
341 				    "duplicated ND6 option found (type=%d)\n",
342 				    nd_opt->nd_opt_type));
343 				/* XXX bark? */
344 			} else {
345 				ndopts->nd_opt_array[nd_opt->nd_opt_type]
346 					= nd_opt;
347 			}
348 			break;
349 		case ND_OPT_PREFIX_INFORMATION:
350 			if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
351 				ndopts->nd_opt_array[nd_opt->nd_opt_type]
352 					= nd_opt;
353 			}
354 			ndopts->nd_opts_pi_end =
355 				(struct nd_opt_prefix_info *)nd_opt;
356 			break;
357 		default:
358 			/*
359 			 * Unknown options must be silently ignored,
360 			 * to accommodate future extension to the protocol.
361 			 */
362 			nd6log((LOG_DEBUG,
363 			    "nd6_options: unsupported option %d - "
364 			    "option ignored\n", nd_opt->nd_opt_type));
365 		}
366 
367 skip1:
368 		i++;
369 		if (i > nd6_maxndopt) {
370 			ICMP6_STATINC(ICMP6_STAT_ND_TOOMANYOPT);
371 			nd6log((LOG_INFO, "too many loop in nd opt\n"));
372 			break;
373 		}
374 
375 		if (ndopts->nd_opts_done)
376 			break;
377 	}
378 
379 	return 0;
380 }
381 
382 /*
383  * ND6 timer routine to handle ND6 entries
384  */
385 void
386 nd6_llinfo_settimer(struct llinfo_nd6 *ln, long xtick)
387 {
388 	int s;
389 
390 	s = splsoftnet();
391 
392 	if (xtick < 0) {
393 		ln->ln_expire = 0;
394 		ln->ln_ntick = 0;
395 		callout_stop(&ln->ln_timer_ch);
396 	} else {
397 		ln->ln_expire = time_second + xtick / hz;
398 		if (xtick > INT_MAX) {
399 			ln->ln_ntick = xtick - INT_MAX;
400 			callout_reset(&ln->ln_timer_ch, INT_MAX,
401 			    nd6_llinfo_timer, ln);
402 		} else {
403 			ln->ln_ntick = 0;
404 			callout_reset(&ln->ln_timer_ch, xtick,
405 			    nd6_llinfo_timer, ln);
406 		}
407 	}
408 
409 	splx(s);
410 }
411 
412 static void
413 nd6_llinfo_timer(void *arg)
414 {
415 	struct llinfo_nd6 *ln;
416 	struct rtentry *rt;
417 	const struct sockaddr_in6 *dst;
418 	struct ifnet *ifp;
419 	struct nd_ifinfo *ndi = NULL;
420 
421 	mutex_enter(softnet_lock);
422 	KERNEL_LOCK(1, NULL);
423 
424 	ln = (struct llinfo_nd6 *)arg;
425 
426 	if (ln->ln_ntick > 0) {
427 		nd6_llinfo_settimer(ln, ln->ln_ntick);
428 		KERNEL_UNLOCK_ONE(NULL);
429 		mutex_exit(softnet_lock);
430 		return;
431 	}
432 
433 	if ((rt = ln->ln_rt) == NULL)
434 		panic("ln->ln_rt == NULL");
435 	if ((ifp = rt->rt_ifp) == NULL)
436 		panic("ln->ln_rt->rt_ifp == NULL");
437 	ndi = ND_IFINFO(ifp);
438 	dst = satocsin6(rt_getkey(rt));
439 
440 	/* sanity check */
441 	if (rt->rt_llinfo && (struct llinfo_nd6 *)rt->rt_llinfo != ln)
442 		panic("rt_llinfo(%p) is not equal to ln(%p)",
443 		      rt->rt_llinfo, ln);
444 	if (!dst)
445 		panic("dst=0 in nd6_timer(ln=%p)", ln);
446 
447 	switch (ln->ln_state) {
448 	case ND6_LLINFO_INCOMPLETE:
449 		if (ln->ln_asked < nd6_mmaxtries) {
450 			ln->ln_asked++;
451 			nd6_llinfo_settimer(ln, (long)ndi->retrans * hz / 1000);
452 			nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0);
453 		} else {
454 			struct mbuf *m = ln->ln_hold;
455 			if (m) {
456 				struct mbuf *m0;
457 
458 				/*
459 				 * assuming every packet in ln_hold has
460 				 * the same IP header
461 				 */
462 				m0 = m->m_nextpkt;
463 				m->m_nextpkt = NULL;
464 				icmp6_error2(m, ICMP6_DST_UNREACH,
465 				    ICMP6_DST_UNREACH_ADDR, 0, rt->rt_ifp);
466 
467 				ln->ln_hold = m0;
468 				clear_llinfo_pqueue(ln);
469  			}
470 			(void)nd6_free(rt, 0);
471 			ln = NULL;
472 		}
473 		break;
474 	case ND6_LLINFO_REACHABLE:
475 		if (!ND6_LLINFO_PERMANENT(ln)) {
476 			ln->ln_state = ND6_LLINFO_STALE;
477 			nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz);
478 		}
479 		break;
480 
481 	case ND6_LLINFO_STALE:
482 		/* Garbage Collection(RFC 2461 5.3) */
483 		if (!ND6_LLINFO_PERMANENT(ln)) {
484 			(void)nd6_free(rt, 1);
485 			ln = NULL;
486 		}
487 		break;
488 
489 	case ND6_LLINFO_DELAY:
490 		if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) {
491 			/* We need NUD */
492 			ln->ln_asked = 1;
493 			ln->ln_state = ND6_LLINFO_PROBE;
494 			nd6_llinfo_settimer(ln, (long)ndi->retrans * hz / 1000);
495 			nd6_ns_output(ifp, &dst->sin6_addr,
496 			    &dst->sin6_addr, ln, 0);
497 		} else {
498 			ln->ln_state = ND6_LLINFO_STALE; /* XXX */
499 			nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz);
500 		}
501 		break;
502 	case ND6_LLINFO_PROBE:
503 		if (ln->ln_asked < nd6_umaxtries) {
504 			ln->ln_asked++;
505 			nd6_llinfo_settimer(ln, (long)ndi->retrans * hz / 1000);
506 			nd6_ns_output(ifp, &dst->sin6_addr,
507 			    &dst->sin6_addr, ln, 0);
508 		} else {
509 			(void)nd6_free(rt, 0);
510 			ln = NULL;
511 		}
512 		break;
513 	}
514 
515 	KERNEL_UNLOCK_ONE(NULL);
516 	mutex_exit(softnet_lock);
517 }
518 
519 /*
520  * ND6 timer routine to expire default route list and prefix list
521  */
522 void
523 nd6_timer(void *ignored_arg)
524 {
525 	struct nd_defrouter *next_dr, *dr;
526 	struct nd_prefix *next_pr, *pr;
527 	struct in6_ifaddr *ia6, *nia6;
528 
529 	callout_reset(&nd6_timer_ch, nd6_prune * hz,
530 	    nd6_timer, NULL);
531 
532 	mutex_enter(softnet_lock);
533 	KERNEL_LOCK(1, NULL);
534 
535 	/* expire default router list */
536 
537 	for (dr = TAILQ_FIRST(&nd_defrouter); dr != NULL; dr = next_dr) {
538 		next_dr = TAILQ_NEXT(dr, dr_entry);
539 		if (dr->expire && dr->expire < time_second) {
540 			defrtrlist_del(dr);
541 		}
542 	}
543 
544 	/*
545 	 * expire interface addresses.
546 	 * in the past the loop was inside prefix expiry processing.
547 	 * However, from a stricter speci-confrmance standpoint, we should
548 	 * rather separate address lifetimes and prefix lifetimes.
549 	 */
550   addrloop:
551 	for (ia6 = in6_ifaddr; ia6; ia6 = nia6) {
552 		nia6 = ia6->ia_next;
553 		/* check address lifetime */
554 		if (IFA6_IS_INVALID(ia6)) {
555 			int regen = 0;
556 
557 			/*
558 			 * If the expiring address is temporary, try
559 			 * regenerating a new one.  This would be useful when
560 			 * we suspended a laptop PC, then turned it on after a
561 			 * period that could invalidate all temporary
562 			 * addresses.  Although we may have to restart the
563 			 * loop (see below), it must be after purging the
564 			 * address.  Otherwise, we'd see an infinite loop of
565 			 * regeneration.
566 			 */
567 			if (ip6_use_tempaddr &&
568 			    (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
569 				if (regen_tmpaddr(ia6) == 0)
570 					regen = 1;
571 			}
572 
573  			in6_purgeaddr(&ia6->ia_ifa);
574 
575 			if (regen)
576 				goto addrloop; /* XXX: see below */
577 		} else if (IFA6_IS_DEPRECATED(ia6)) {
578 			int oldflags = ia6->ia6_flags;
579 
580  			ia6->ia6_flags |= IN6_IFF_DEPRECATED;
581 
582 			/*
583 			 * If a temporary address has just become deprecated,
584 			 * regenerate a new one if possible.
585 			 */
586 			if (ip6_use_tempaddr &&
587 			    (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
588 			    (oldflags & IN6_IFF_DEPRECATED) == 0) {
589 
590 				if (regen_tmpaddr(ia6) == 0) {
591 					/*
592 					 * A new temporary address is
593 					 * generated.
594 					 * XXX: this means the address chain
595 					 * has changed while we are still in
596 					 * the loop.  Although the change
597 					 * would not cause disaster (because
598 					 * it's not a deletion, but an
599 					 * addition,) we'd rather restart the
600 					 * loop just for safety.  Or does this
601 					 * significantly reduce performance??
602 					 */
603 					goto addrloop;
604 				}
605 			}
606 		} else {
607 			/*
608 			 * A new RA might have made a deprecated address
609 			 * preferred.
610 			 */
611 			ia6->ia6_flags &= ~IN6_IFF_DEPRECATED;
612 		}
613 	}
614 
615 	/* expire prefix list */
616 	for (pr = LIST_FIRST(&nd_prefix); pr != NULL; pr = next_pr) {
617 		next_pr = LIST_NEXT(pr, ndpr_entry);
618 		/*
619 		 * check prefix lifetime.
620 		 * since pltime is just for autoconf, pltime processing for
621 		 * prefix is not necessary.
622 		 */
623 		if (pr->ndpr_vltime != ND6_INFINITE_LIFETIME &&
624 		    time_second - pr->ndpr_lastupdate > pr->ndpr_vltime) {
625 
626 			/*
627 			 * address expiration and prefix expiration are
628 			 * separate.  NEVER perform in6_purgeaddr here.
629 			 */
630 
631 			prelist_remove(pr);
632 		}
633 	}
634 
635 	KERNEL_UNLOCK_ONE(NULL);
636 	mutex_exit(softnet_lock);
637 }
638 
639 /* ia6: deprecated/invalidated temporary address */
640 static int
641 regen_tmpaddr(struct in6_ifaddr *ia6)
642 {
643 	struct ifaddr *ifa;
644 	struct ifnet *ifp;
645 	struct in6_ifaddr *public_ifa6 = NULL;
646 
647 	ifp = ia6->ia_ifa.ifa_ifp;
648 	IFADDR_FOREACH(ifa, ifp) {
649 		struct in6_ifaddr *it6;
650 
651 		if (ifa->ifa_addr->sa_family != AF_INET6)
652 			continue;
653 
654 		it6 = (struct in6_ifaddr *)ifa;
655 
656 		/* ignore no autoconf addresses. */
657 		if ((it6->ia6_flags & IN6_IFF_AUTOCONF) == 0)
658 			continue;
659 
660 		/* ignore autoconf addresses with different prefixes. */
661 		if (it6->ia6_ndpr == NULL || it6->ia6_ndpr != ia6->ia6_ndpr)
662 			continue;
663 
664 		/*
665 		 * Now we are looking at an autoconf address with the same
666 		 * prefix as ours.  If the address is temporary and is still
667 		 * preferred, do not create another one.  It would be rare, but
668 		 * could happen, for example, when we resume a laptop PC after
669 		 * a long period.
670 		 */
671 		if ((it6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
672 		    !IFA6_IS_DEPRECATED(it6)) {
673 			public_ifa6 = NULL;
674 			break;
675 		}
676 
677 		/*
678 		 * This is a public autoconf address that has the same prefix
679 		 * as ours.  If it is preferred, keep it.  We can't break the
680 		 * loop here, because there may be a still-preferred temporary
681 		 * address with the prefix.
682 		 */
683 		if (!IFA6_IS_DEPRECATED(it6))
684 		    public_ifa6 = it6;
685 	}
686 
687 	if (public_ifa6 != NULL) {
688 		int e;
689 
690 		/*
691 		 * Random factor is introduced in the preferred lifetime, so
692 		 * we do not need additional delay (3rd arg to in6_tmpifadd).
693 		 */
694 		if ((e = in6_tmpifadd(public_ifa6, 0, 0)) != 0) {
695 			log(LOG_NOTICE, "regen_tmpaddr: failed to create a new"
696 			    " tmp addr, errno=%d\n", e);
697 			return -1;
698 		}
699 		return 0;
700 	}
701 
702 	return -1;
703 }
704 
705 bool
706 nd6_accepts_rtadv(const struct nd_ifinfo *ndi)
707 {
708 	switch (ndi->flags & (ND6_IFF_ACCEPT_RTADV|ND6_IFF_OVERRIDE_RTADV)) {
709 	case ND6_IFF_OVERRIDE_RTADV|ND6_IFF_ACCEPT_RTADV:
710 		return true;
711 	case ND6_IFF_ACCEPT_RTADV:
712 		return ip6_accept_rtadv != 0;
713 	case ND6_IFF_OVERRIDE_RTADV:
714 	case 0:
715 	default:
716 		return false;
717 	}
718 }
719 
720 /*
721  * Nuke neighbor cache/prefix/default router management table, right before
722  * ifp goes away.
723  */
724 void
725 nd6_purge(struct ifnet *ifp)
726 {
727 	struct nd_ifinfo *ndi = ND_IFINFO(ifp);
728 	struct llinfo_nd6 *ln, *nln;
729 	struct nd_defrouter *dr, *ndr;
730 	struct nd_prefix *pr, *npr;
731 
732 	/*
733 	 * Nuke default router list entries toward ifp.
734 	 * We defer removal of default router list entries that is installed
735 	 * in the routing table, in order to keep additional side effects as
736 	 * small as possible.
737 	 */
738 	for (dr = TAILQ_FIRST(&nd_defrouter); dr != NULL; dr = ndr) {
739 		ndr = TAILQ_NEXT(dr, dr_entry);
740 		if (dr->installed)
741 			continue;
742 
743 		if (dr->ifp == ifp)
744 			defrtrlist_del(dr);
745 	}
746 	for (dr = TAILQ_FIRST(&nd_defrouter); dr != NULL; dr = ndr) {
747 		ndr = TAILQ_NEXT(dr, dr_entry);
748 		if (!dr->installed)
749 			continue;
750 
751 		if (dr->ifp == ifp)
752 			defrtrlist_del(dr);
753 	}
754 
755 	/* Nuke prefix list entries toward ifp */
756 	for (pr = LIST_FIRST(&nd_prefix); pr != NULL; pr = npr) {
757 		npr = LIST_NEXT(pr, ndpr_entry);
758 		if (pr->ndpr_ifp == ifp) {
759 			/*
760 			 * Because if_detach() does *not* release prefixes
761 			 * while purging addresses the reference count will
762 			 * still be above zero. We therefore reset it to
763 			 * make sure that the prefix really gets purged.
764 			 */
765 			pr->ndpr_refcnt = 0;
766 			/*
767 			 * Previously, pr->ndpr_addr is removed as well,
768 			 * but I strongly believe we don't have to do it.
769 			 * nd6_purge() is only called from in6_ifdetach(),
770 			 * which removes all the associated interface addresses
771 			 * by itself.
772 			 * (jinmei@kame.net 20010129)
773 			 */
774 			prelist_remove(pr);
775 		}
776 	}
777 
778 	/* cancel default outgoing interface setting */
779 	if (nd6_defifindex == ifp->if_index)
780 		nd6_setdefaultiface(0);
781 
782 	/* XXX: too restrictive? */
783 	if (!ip6_forwarding && ndi && nd6_accepts_rtadv(ndi)) {
784 		/* refresh default router list */
785 		defrouter_select();
786 	}
787 
788 	/*
789 	 * Nuke neighbor cache entries for the ifp.
790 	 * Note that rt->rt_ifp may not be the same as ifp,
791 	 * due to KAME goto ours hack.  See RTM_RESOLVE case in
792 	 * nd6_rtrequest(), and ip6_input().
793 	 */
794 	ln = llinfo_nd6.ln_next;
795 	while (ln != NULL && ln != &llinfo_nd6) {
796 		struct rtentry *rt;
797 		const struct sockaddr_dl *sdl;
798 
799 		nln = ln->ln_next;
800 		rt = ln->ln_rt;
801 		if (rt && rt->rt_gateway &&
802 		    rt->rt_gateway->sa_family == AF_LINK) {
803 			sdl = satocsdl(rt->rt_gateway);
804 			if (sdl->sdl_index == ifp->if_index)
805 				nln = nd6_free(rt, 0);
806 		}
807 		ln = nln;
808 	}
809 }
810 
811 struct rtentry *
812 nd6_lookup(const struct in6_addr *addr6, int create, struct ifnet *ifp)
813 {
814 	struct rtentry *rt;
815 	struct sockaddr_in6 sin6;
816 
817 	sockaddr_in6_init(&sin6, addr6, 0, 0, 0);
818 	rt = rtalloc1((struct sockaddr *)&sin6, create);
819 	if (rt != NULL && (rt->rt_flags & RTF_LLINFO) == 0) {
820 		/*
821 		 * This is the case for the default route.
822 		 * If we want to create a neighbor cache for the address, we
823 		 * should free the route for the destination and allocate an
824 		 * interface route.
825 		 */
826 		if (create) {
827 			RTFREE(rt);
828 			rt = NULL;
829 		}
830 	}
831 	if (rt != NULL)
832 		;
833 	else if (create && ifp) {
834 		int e;
835 
836 		/*
837 		 * If no route is available and create is set,
838 		 * we allocate a host route for the destination
839 		 * and treat it like an interface route.
840 		 * This hack is necessary for a neighbor which can't
841 		 * be covered by our own prefix.
842 		 */
843 		struct ifaddr *ifa =
844 		    ifaof_ifpforaddr((struct sockaddr *)&sin6, ifp);
845 		if (ifa == NULL)
846 			return NULL;
847 
848 		/*
849 		 * Create a new route.  RTF_LLINFO is necessary
850 		 * to create a Neighbor Cache entry for the
851 		 * destination in nd6_rtrequest which will be
852 		 * called in rtrequest via ifa->ifa_rtrequest.
853 		 */
854 		if ((e = rtrequest(RTM_ADD, (const struct sockaddr *)&sin6,
855 		    ifa->ifa_addr, (const struct sockaddr *)&all1_sa,
856 		    (ifa->ifa_flags | RTF_HOST | RTF_LLINFO) &
857 		    ~RTF_CLONING, &rt)) != 0) {
858 #if 0
859 			log(LOG_ERR,
860 			    "nd6_lookup: failed to add route for a "
861 			    "neighbor(%s), errno=%d\n",
862 			    ip6_sprintf(addr6), e);
863 #endif
864 			return NULL;
865 		}
866 		if (rt == NULL)
867 			return NULL;
868 		if (rt->rt_llinfo) {
869 			struct llinfo_nd6 *ln =
870 			    (struct llinfo_nd6 *)rt->rt_llinfo;
871 			ln->ln_state = ND6_LLINFO_NOSTATE;
872 		}
873 	} else
874 		return NULL;
875 	rt->rt_refcnt--;
876 	/*
877 	 * Validation for the entry.
878 	 * Note that the check for rt_llinfo is necessary because a cloned
879 	 * route from a parent route that has the L flag (e.g. the default
880 	 * route to a p2p interface) may have the flag, too, while the
881 	 * destination is not actually a neighbor.
882 	 * XXX: we can't use rt->rt_ifp to check for the interface, since
883 	 *      it might be the loopback interface if the entry is for our
884 	 *      own address on a non-loopback interface. Instead, we should
885 	 *      use rt->rt_ifa->ifa_ifp, which would specify the REAL
886 	 *	interface.
887 	 * Note also that ifa_ifp and ifp may differ when we connect two
888 	 * interfaces to a same link, install a link prefix to an interface,
889 	 * and try to install a neighbor cache on an interface that does not
890 	 * have a route to the prefix.
891 	 */
892 	if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 ||
893 	    rt->rt_gateway->sa_family != AF_LINK || rt->rt_llinfo == NULL ||
894 	    (ifp && rt->rt_ifa->ifa_ifp != ifp)) {
895 		if (create) {
896 			nd6log((LOG_DEBUG,
897 			    "nd6_lookup: failed to lookup %s (if = %s)\n",
898 			    ip6_sprintf(addr6),
899 			    ifp ? if_name(ifp) : "unspec"));
900 		}
901 		return NULL;
902 	}
903 	return rt;
904 }
905 
906 /*
907  * Detect if a given IPv6 address identifies a neighbor on a given link.
908  * XXX: should take care of the destination of a p2p link?
909  */
910 int
911 nd6_is_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp)
912 {
913 	struct nd_prefix *pr;
914 
915 	/*
916 	 * A link-local address is always a neighbor.
917 	 * XXX: a link does not necessarily specify a single interface.
918 	 */
919 	if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) {
920 		struct sockaddr_in6 sin6_copy;
921 		u_int32_t zone;
922 
923 		/*
924 		 * We need sin6_copy since sa6_recoverscope() may modify the
925 		 * content (XXX).
926 		 */
927 		sin6_copy = *addr;
928 		if (sa6_recoverscope(&sin6_copy))
929 			return 0; /* XXX: should be impossible */
930 		if (in6_setscope(&sin6_copy.sin6_addr, ifp, &zone))
931 			return 0;
932 		if (sin6_copy.sin6_scope_id == zone)
933 			return 1;
934 		else
935 			return 0;
936 	}
937 
938 	/*
939 	 * If the address matches one of our on-link prefixes, it should be a
940 	 * neighbor.
941 	 */
942 	LIST_FOREACH(pr, &nd_prefix, ndpr_entry) {
943 		if (pr->ndpr_ifp != ifp)
944 			continue;
945 
946 		if (!(pr->ndpr_stateflags & NDPRF_ONLINK))
947 			continue;
948 
949 		if (IN6_ARE_MASKED_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
950 		    &addr->sin6_addr, &pr->ndpr_mask))
951 			return 1;
952 	}
953 
954 	/*
955 	 * If the default router list is empty, all addresses are regarded
956 	 * as on-link, and thus, as a neighbor.
957 	 * XXX: we restrict the condition to hosts, because routers usually do
958 	 * not have the "default router list".
959 	 */
960 	if (!ip6_forwarding && TAILQ_FIRST(&nd_defrouter) == NULL &&
961 	    nd6_defifindex == ifp->if_index) {
962 		return 1;
963 	}
964 
965 	/*
966 	 * Even if the address matches none of our addresses, it might be
967 	 * in the neighbor cache.
968 	 */
969 	if (nd6_lookup(&addr->sin6_addr, 0, ifp) != NULL)
970 		return 1;
971 
972 	return 0;
973 }
974 
975 /*
976  * Free an nd6 llinfo entry.
977  * Since the function would cause significant changes in the kernel, DO NOT
978  * make it global, unless you have a strong reason for the change, and are sure
979  * that the change is safe.
980  */
981 static struct llinfo_nd6 *
982 nd6_free(struct rtentry *rt, int gc)
983 {
984 	struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo, *next;
985 	struct in6_addr in6 = satocsin6(rt_getkey(rt))->sin6_addr;
986 	struct nd_defrouter *dr;
987 
988 	/*
989 	 * we used to have pfctlinput(PRC_HOSTDEAD) here.
990 	 * even though it is not harmful, it was not really necessary.
991 	 */
992 
993 	/* cancel timer */
994 	nd6_llinfo_settimer(ln, -1);
995 
996 	if (!ip6_forwarding) {
997 		int s;
998 		s = splsoftnet();
999 		dr = defrouter_lookup(&satocsin6(rt_getkey(rt))->sin6_addr,
1000 		    rt->rt_ifp);
1001 
1002 		if (dr != NULL && dr->expire &&
1003 		    ln->ln_state == ND6_LLINFO_STALE && gc) {
1004 			/*
1005 			 * If the reason for the deletion is just garbage
1006 			 * collection, and the neighbor is an active default
1007 			 * router, do not delete it.  Instead, reset the GC
1008 			 * timer using the router's lifetime.
1009 			 * Simply deleting the entry would affect default
1010 			 * router selection, which is not necessarily a good
1011 			 * thing, especially when we're using router preference
1012 			 * values.
1013 			 * XXX: the check for ln_state would be redundant,
1014 			 *      but we intentionally keep it just in case.
1015 			 */
1016 			if (dr->expire > time_second)
1017 				nd6_llinfo_settimer(ln,
1018 				    (dr->expire - time_second) * hz);
1019 			else
1020 				nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz);
1021 			splx(s);
1022 			return ln->ln_next;
1023 		}
1024 
1025 		if (ln->ln_router || dr) {
1026 			/*
1027 			 * rt6_flush must be called whether or not the neighbor
1028 			 * is in the Default Router List.
1029 			 * See a corresponding comment in nd6_na_input().
1030 			 */
1031 			rt6_flush(&in6, rt->rt_ifp);
1032 		}
1033 
1034 		if (dr) {
1035 			/*
1036 			 * Unreachablity of a router might affect the default
1037 			 * router selection and on-link detection of advertised
1038 			 * prefixes.
1039 			 */
1040 
1041 			/*
1042 			 * Temporarily fake the state to choose a new default
1043 			 * router and to perform on-link determination of
1044 			 * prefixes correctly.
1045 			 * Below the state will be set correctly,
1046 			 * or the entry itself will be deleted.
1047 			 */
1048 			ln->ln_state = ND6_LLINFO_INCOMPLETE;
1049 
1050 			/*
1051 			 * Since defrouter_select() does not affect the
1052 			 * on-link determination and MIP6 needs the check
1053 			 * before the default router selection, we perform
1054 			 * the check now.
1055 			 */
1056 			pfxlist_onlink_check();
1057 
1058 			/*
1059 			 * refresh default router list
1060 			 */
1061 			defrouter_select();
1062 		}
1063 		splx(s);
1064 	}
1065 
1066 	/*
1067 	 * Before deleting the entry, remember the next entry as the
1068 	 * return value.  We need this because pfxlist_onlink_check() above
1069 	 * might have freed other entries (particularly the old next entry) as
1070 	 * a side effect (XXX).
1071 	 */
1072 	next = ln->ln_next;
1073 
1074 	/*
1075 	 * Detach the route from the routing tree and the list of neighbor
1076 	 * caches, and disable the route entry not to be used in already
1077 	 * cached routes.
1078 	 */
1079 	rtrequest(RTM_DELETE, rt_getkey(rt), NULL, rt_mask(rt), 0, NULL);
1080 
1081 	return next;
1082 }
1083 
1084 /*
1085  * Upper-layer reachability hint for Neighbor Unreachability Detection.
1086  *
1087  * XXX cost-effective methods?
1088  */
1089 void
1090 nd6_nud_hint(struct rtentry *rt, struct in6_addr *dst6, int force)
1091 {
1092 	struct llinfo_nd6 *ln;
1093 
1094 	/*
1095 	 * If the caller specified "rt", use that.  Otherwise, resolve the
1096 	 * routing table by supplied "dst6".
1097 	 */
1098 	if (rt == NULL) {
1099 		if (dst6 == NULL)
1100 			return;
1101 		if ((rt = nd6_lookup(dst6, 0, NULL)) == NULL)
1102 			return;
1103 	}
1104 
1105 	if ((rt->rt_flags & RTF_GATEWAY) != 0 ||
1106 	    (rt->rt_flags & RTF_LLINFO) == 0 ||
1107 	    !rt->rt_llinfo || !rt->rt_gateway ||
1108 	    rt->rt_gateway->sa_family != AF_LINK) {
1109 		/* This is not a host route. */
1110 		return;
1111 	}
1112 
1113 	ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1114 	if (ln->ln_state < ND6_LLINFO_REACHABLE)
1115 		return;
1116 
1117 	/*
1118 	 * if we get upper-layer reachability confirmation many times,
1119 	 * it is possible we have false information.
1120 	 */
1121 	if (!force) {
1122 		ln->ln_byhint++;
1123 		if (ln->ln_byhint > nd6_maxnudhint)
1124 			return;
1125 	}
1126 
1127 	ln->ln_state = ND6_LLINFO_REACHABLE;
1128 	if (!ND6_LLINFO_PERMANENT(ln)) {
1129 		nd6_llinfo_settimer(ln,
1130 		    (long)ND_IFINFO(rt->rt_ifp)->reachable * hz);
1131 	}
1132 }
1133 
1134 void
1135 nd6_rtrequest(int req, struct rtentry *rt, const struct rt_addrinfo *info)
1136 {
1137 	struct sockaddr *gate = rt->rt_gateway;
1138 	struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1139 	struct ifnet *ifp = rt->rt_ifp;
1140 	uint8_t namelen = strlen(ifp->if_xname), addrlen = ifp->if_addrlen;
1141 	struct ifaddr *ifa;
1142 
1143 	RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1144 
1145 	if (req == RTM_LLINFO_UPD) {
1146 		int rc;
1147 		struct in6_addr *in6;
1148 		struct in6_addr in6_all;
1149 		int anycast;
1150 
1151 		if ((ifa = info->rti_ifa) == NULL)
1152 			return;
1153 
1154 		in6 = &ifatoia6(ifa)->ia_addr.sin6_addr;
1155 		anycast = ifatoia6(ifa)->ia6_flags & IN6_IFF_ANYCAST;
1156 
1157 		in6_all = in6addr_linklocal_allnodes;
1158 		if ((rc = in6_setscope(&in6_all, ifa->ifa_ifp, NULL)) != 0) {
1159 			log(LOG_ERR, "%s: failed to set scope %s "
1160 			    "(errno=%d)\n", __func__, if_name(ifp), rc);
1161 			return;
1162 		}
1163 
1164 		/* XXX don't set Override for proxy addresses */
1165 		nd6_na_output(ifa->ifa_ifp, &in6_all, in6,
1166 		    (anycast ? 0 : ND_NA_FLAG_OVERRIDE)
1167 #if 0
1168 		    | (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0)
1169 #endif
1170 		    , 1, NULL);
1171 		return;
1172 	}
1173 
1174 	if ((rt->rt_flags & RTF_GATEWAY) != 0)
1175 		return;
1176 
1177 	if (nd6_need_cache(ifp) == 0 && (rt->rt_flags & RTF_HOST) == 0) {
1178 		RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1179 		/*
1180 		 * This is probably an interface direct route for a link
1181 		 * which does not need neighbor caches (e.g. fe80::%lo0/64).
1182 		 * We do not need special treatment below for such a route.
1183 		 * Moreover, the RTF_LLINFO flag which would be set below
1184 		 * would annoy the ndp(8) command.
1185 		 */
1186 		return;
1187 	}
1188 
1189 	if (req == RTM_RESOLVE &&
1190 	    (nd6_need_cache(ifp) == 0 || /* stf case */
1191 	     !nd6_is_addr_neighbor(satocsin6(rt_getkey(rt)), ifp))) {
1192 		RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1193 		/*
1194 		 * FreeBSD and BSD/OS often make a cloned host route based
1195 		 * on a less-specific route (e.g. the default route).
1196 		 * If the less specific route does not have a "gateway"
1197 		 * (this is the case when the route just goes to a p2p or an
1198 		 * stf interface), we'll mistakenly make a neighbor cache for
1199 		 * the host route, and will see strange neighbor solicitation
1200 		 * for the corresponding destination.  In order to avoid the
1201 		 * confusion, we check if the destination of the route is
1202 		 * a neighbor in terms of neighbor discovery, and stop the
1203 		 * process if not.  Additionally, we remove the LLINFO flag
1204 		 * so that ndp(8) will not try to get the neighbor information
1205 		 * of the destination.
1206 		 */
1207 		rt->rt_flags &= ~RTF_LLINFO;
1208 		return;
1209 	}
1210 
1211 	switch (req) {
1212 	case RTM_ADD:
1213 		RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1214 		/*
1215 		 * There is no backward compatibility :)
1216 		 *
1217 		 * if ((rt->rt_flags & RTF_HOST) == 0 &&
1218 		 *     SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff)
1219 		 *	   rt->rt_flags |= RTF_CLONING;
1220 		 */
1221 		if ((rt->rt_flags & RTF_CLONING) ||
1222 		    ((rt->rt_flags & RTF_LLINFO) && ln == NULL)) {
1223 			union {
1224 				struct sockaddr sa;
1225 				struct sockaddr_dl sdl;
1226 				struct sockaddr_storage ss;
1227 			} u;
1228 			/*
1229 			 * Case 1: This route should come from a route to
1230 			 * interface (RTF_CLONING case) or the route should be
1231 			 * treated as on-link but is currently not
1232 			 * (RTF_LLINFO && ln == NULL case).
1233 			 */
1234 			if (sockaddr_dl_init(&u.sdl, sizeof(u.ss),
1235 			    ifp->if_index, ifp->if_type,
1236 			    NULL, namelen, NULL, addrlen) == NULL) {
1237 				printf("%s.%d: sockaddr_dl_init(, %zu, ) "
1238 				    "failed on %s\n", __func__, __LINE__,
1239 				    sizeof(u.ss), if_name(ifp));
1240 			}
1241 			rt_setgate(rt, &u.sa);
1242 			gate = rt->rt_gateway;
1243 			RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1244 			if (ln != NULL)
1245 				nd6_llinfo_settimer(ln, 0);
1246 			RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1247 			if ((rt->rt_flags & RTF_CLONING) != 0)
1248 				break;
1249 		}
1250 		RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1251 		/*
1252 		 * In IPv4 code, we try to annonuce new RTF_ANNOUNCE entry here.
1253 		 * We don't do that here since llinfo is not ready yet.
1254 		 *
1255 		 * There are also couple of other things to be discussed:
1256 		 * - unsolicited NA code needs improvement beforehand
1257 		 * - RFC2461 says we MAY send multicast unsolicited NA
1258 		 *   (7.2.6 paragraph 4), however, it also says that we
1259 		 *   SHOULD provide a mechanism to prevent multicast NA storm.
1260 		 *   we don't have anything like it right now.
1261 		 *   note that the mechanism needs a mutual agreement
1262 		 *   between proxies, which means that we need to implement
1263 		 *   a new protocol, or a new kludge.
1264 		 * - from RFC2461 6.2.4, host MUST NOT send an unsolicited NA.
1265 		 *   we need to check ip6forwarding before sending it.
1266 		 *   (or should we allow proxy ND configuration only for
1267 		 *   routers?  there's no mention about proxy ND from hosts)
1268 		 */
1269 #if 0
1270 		/* XXX it does not work */
1271 		if (rt->rt_flags & RTF_ANNOUNCE)
1272 			nd6_na_output(ifp,
1273 			      &satocsin6(rt_getkey(rt))->sin6_addr,
1274 			      &satocsin6(rt_getkey(rt))->sin6_addr,
1275 			      ip6_forwarding ? ND_NA_FLAG_ROUTER : 0,
1276 			      1, NULL);
1277 #endif
1278 		/* FALLTHROUGH */
1279 	case RTM_RESOLVE:
1280 		if ((ifp->if_flags & (IFF_POINTOPOINT | IFF_LOOPBACK)) == 0) {
1281 			RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1282 			/*
1283 			 * Address resolution isn't necessary for a point to
1284 			 * point link, so we can skip this test for a p2p link.
1285 			 */
1286 			if (gate->sa_family != AF_LINK ||
1287 			    gate->sa_len <
1288 			    sockaddr_dl_measure(namelen, addrlen)) {
1289 				log(LOG_DEBUG,
1290 				    "nd6_rtrequest: bad gateway value: %s\n",
1291 				    if_name(ifp));
1292 				break;
1293 			}
1294 			satosdl(gate)->sdl_type = ifp->if_type;
1295 			satosdl(gate)->sdl_index = ifp->if_index;
1296 			RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1297 		}
1298 		if (ln != NULL)
1299 			break;	/* This happens on a route change */
1300 		RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1301 		/*
1302 		 * Case 2: This route may come from cloning, or a manual route
1303 		 * add with a LL address.
1304 		 */
1305 		R_Malloc(ln, struct llinfo_nd6 *, sizeof(*ln));
1306 		rt->rt_llinfo = ln;
1307 		RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1308 		if (ln == NULL) {
1309 			log(LOG_DEBUG, "nd6_rtrequest: malloc failed\n");
1310 			break;
1311 		}
1312 		RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1313 		nd6_inuse++;
1314 		nd6_allocated++;
1315 		memset(ln, 0, sizeof(*ln));
1316 		ln->ln_rt = rt;
1317 		callout_init(&ln->ln_timer_ch, CALLOUT_MPSAFE);
1318 		/* this is required for "ndp" command. - shin */
1319 		if (req == RTM_ADD) {
1320 		        /*
1321 			 * gate should have some valid AF_LINK entry,
1322 			 * and ln->ln_expire should have some lifetime
1323 			 * which is specified by ndp command.
1324 			 */
1325 			ln->ln_state = ND6_LLINFO_REACHABLE;
1326 			ln->ln_byhint = 0;
1327 		} else {
1328 		        /*
1329 			 * When req == RTM_RESOLVE, rt is created and
1330 			 * initialized in rtrequest(), so rt_expire is 0.
1331 			 */
1332 			ln->ln_state = ND6_LLINFO_NOSTATE;
1333 			nd6_llinfo_settimer(ln, 0);
1334 		}
1335 		RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1336 		rt->rt_flags |= RTF_LLINFO;
1337 		ln->ln_next = llinfo_nd6.ln_next;
1338 		llinfo_nd6.ln_next = ln;
1339 		ln->ln_prev = &llinfo_nd6;
1340 		ln->ln_next->ln_prev = ln;
1341 
1342 		RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1343 		/*
1344 		 * check if rt_getkey(rt) is an address assigned
1345 		 * to the interface.
1346 		 */
1347 		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp,
1348 		    &satocsin6(rt_getkey(rt))->sin6_addr);
1349 		RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1350 		if (ifa != NULL) {
1351 			const void *mac;
1352 			nd6_llinfo_settimer(ln, -1);
1353 			ln->ln_state = ND6_LLINFO_REACHABLE;
1354 			ln->ln_byhint = 0;
1355 			if ((mac = nd6_ifptomac(ifp)) != NULL) {
1356 				/* XXX check for error */
1357 				if (sockaddr_dl_setaddr(satosdl(gate),
1358 				    gate->sa_len, mac,
1359 				    ifp->if_addrlen) == NULL) {
1360 					printf("%s.%d: "
1361 					    "sockaddr_dl_setaddr(, %d, ) "
1362 					    "failed on %s\n", __func__,
1363 					    __LINE__, gate->sa_len,
1364 					    if_name(ifp));
1365 				}
1366 			}
1367 			if (nd6_useloopback) {
1368 				ifp = rt->rt_ifp = lo0ifp;	/* XXX */
1369 				/*
1370 				 * Make sure rt_ifa be equal to the ifaddr
1371 				 * corresponding to the address.
1372 				 * We need this because when we refer
1373 				 * rt_ifa->ia6_flags in ip6_input, we assume
1374 				 * that the rt_ifa points to the address instead
1375 				 * of the loopback address.
1376 				 */
1377 				if (ifa != rt->rt_ifa)
1378 					rt_replace_ifa(rt, ifa);
1379 				rt->rt_flags &= ~RTF_CLONED;
1380 			}
1381 		} else if (rt->rt_flags & RTF_ANNOUNCE) {
1382 			nd6_llinfo_settimer(ln, -1);
1383 			ln->ln_state = ND6_LLINFO_REACHABLE;
1384 			ln->ln_byhint = 0;
1385 
1386 			/* join solicited node multicast for proxy ND */
1387 			if (ifp->if_flags & IFF_MULTICAST) {
1388 				struct in6_addr llsol;
1389 				int error;
1390 
1391 				llsol = satocsin6(rt_getkey(rt))->sin6_addr;
1392 				llsol.s6_addr32[0] = htonl(0xff020000);
1393 				llsol.s6_addr32[1] = 0;
1394 				llsol.s6_addr32[2] = htonl(1);
1395 				llsol.s6_addr8[12] = 0xff;
1396 				if (in6_setscope(&llsol, ifp, NULL))
1397 					break;
1398 				if (!in6_addmulti(&llsol, ifp, &error, 0)) {
1399 					nd6log((LOG_ERR, "%s: failed to join "
1400 					    "%s (errno=%d)\n", if_name(ifp),
1401 					    ip6_sprintf(&llsol), error));
1402 				}
1403 			}
1404 		}
1405 		break;
1406 
1407 	case RTM_DELETE:
1408 		if (ln == NULL)
1409 			break;
1410 		/* leave from solicited node multicast for proxy ND */
1411 		if ((rt->rt_flags & RTF_ANNOUNCE) != 0 &&
1412 		    (ifp->if_flags & IFF_MULTICAST) != 0) {
1413 			struct in6_addr llsol;
1414 			struct in6_multi *in6m;
1415 
1416 			llsol = satocsin6(rt_getkey(rt))->sin6_addr;
1417 			llsol.s6_addr32[0] = htonl(0xff020000);
1418 			llsol.s6_addr32[1] = 0;
1419 			llsol.s6_addr32[2] = htonl(1);
1420 			llsol.s6_addr8[12] = 0xff;
1421 			if (in6_setscope(&llsol, ifp, NULL) == 0) {
1422 				IN6_LOOKUP_MULTI(llsol, ifp, in6m);
1423 				if (in6m)
1424 					in6_delmulti(in6m);
1425 			}
1426 		}
1427 		nd6_inuse--;
1428 		ln->ln_next->ln_prev = ln->ln_prev;
1429 		ln->ln_prev->ln_next = ln->ln_next;
1430 		ln->ln_prev = NULL;
1431 		nd6_llinfo_settimer(ln, -1);
1432 		rt->rt_llinfo = 0;
1433 		rt->rt_flags &= ~RTF_LLINFO;
1434 		clear_llinfo_pqueue(ln);
1435 		Free(ln);
1436 	}
1437 }
1438 
1439 int
1440 nd6_ioctl(u_long cmd, void *data, struct ifnet *ifp)
1441 {
1442 	struct in6_drlist *drl = (struct in6_drlist *)data;
1443 	struct in6_oprlist *oprl = (struct in6_oprlist *)data;
1444 	struct in6_ndireq *ndi = (struct in6_ndireq *)data;
1445 	struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data;
1446 	struct in6_ndifreq *ndif = (struct in6_ndifreq *)data;
1447 	struct nd_defrouter *dr;
1448 	struct nd_prefix *pr;
1449 	struct rtentry *rt;
1450 	int i = 0, error = 0;
1451 	int s;
1452 
1453 	switch (cmd) {
1454 	case SIOCGDRLST_IN6:
1455 		/*
1456 		 * obsolete API, use sysctl under net.inet6.icmp6
1457 		 */
1458 		memset(drl, 0, sizeof(*drl));
1459 		s = splsoftnet();
1460 		TAILQ_FOREACH(dr, &nd_defrouter, dr_entry) {
1461 			if (i >= DRLSTSIZ)
1462 				break;
1463 			drl->defrouter[i].rtaddr = dr->rtaddr;
1464 			in6_clearscope(&drl->defrouter[i].rtaddr);
1465 
1466 			drl->defrouter[i].flags = dr->flags;
1467 			drl->defrouter[i].rtlifetime = dr->rtlifetime;
1468 			drl->defrouter[i].expire = dr->expire;
1469 			drl->defrouter[i].if_index = dr->ifp->if_index;
1470 			i++;
1471 		}
1472 		splx(s);
1473 		break;
1474 	case SIOCGPRLST_IN6:
1475 		/*
1476 		 * obsolete API, use sysctl under net.inet6.icmp6
1477 		 *
1478 		 * XXX the structure in6_prlist was changed in backward-
1479 		 * incompatible manner.  in6_oprlist is used for SIOCGPRLST_IN6,
1480 		 * in6_prlist is used for nd6_sysctl() - fill_prlist().
1481 		 */
1482 		/*
1483 		 * XXX meaning of fields, especialy "raflags", is very
1484 		 * differnet between RA prefix list and RR/static prefix list.
1485 		 * how about separating ioctls into two?
1486 		 */
1487 		memset(oprl, 0, sizeof(*oprl));
1488 		s = splsoftnet();
1489 		LIST_FOREACH(pr, &nd_prefix, ndpr_entry) {
1490 			struct nd_pfxrouter *pfr;
1491 			int j;
1492 
1493 			if (i >= PRLSTSIZ)
1494 				break;
1495 			oprl->prefix[i].prefix = pr->ndpr_prefix.sin6_addr;
1496 			oprl->prefix[i].raflags = pr->ndpr_raf;
1497 			oprl->prefix[i].prefixlen = pr->ndpr_plen;
1498 			oprl->prefix[i].vltime = pr->ndpr_vltime;
1499 			oprl->prefix[i].pltime = pr->ndpr_pltime;
1500 			oprl->prefix[i].if_index = pr->ndpr_ifp->if_index;
1501 			if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME)
1502 				oprl->prefix[i].expire = 0;
1503 			else {
1504 				time_t maxexpire;
1505 
1506 				/* XXX: we assume time_t is signed. */
1507 				maxexpire = (-1) &
1508 				    ~((time_t)1 <<
1509 				    ((sizeof(maxexpire) * 8) - 1));
1510 				if (pr->ndpr_vltime <
1511 				    maxexpire - pr->ndpr_lastupdate) {
1512 					oprl->prefix[i].expire =
1513 						 pr->ndpr_lastupdate +
1514 						pr->ndpr_vltime;
1515 				} else
1516 					oprl->prefix[i].expire = maxexpire;
1517 			}
1518 
1519 			j = 0;
1520 			LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) {
1521 				if (j < DRLSTSIZ) {
1522 #define RTRADDR oprl->prefix[i].advrtr[j]
1523 					RTRADDR = pfr->router->rtaddr;
1524 					in6_clearscope(&RTRADDR);
1525 #undef RTRADDR
1526 				}
1527 				j++;
1528 			}
1529 			oprl->prefix[i].advrtrs = j;
1530 			oprl->prefix[i].origin = PR_ORIG_RA;
1531 
1532 			i++;
1533 		}
1534 		splx(s);
1535 
1536 		break;
1537 	case OSIOCGIFINFO_IN6:
1538 #define ND	ndi->ndi
1539 		/* XXX: old ndp(8) assumes a positive value for linkmtu. */
1540 		memset(&ND, 0, sizeof(ND));
1541 		ND.linkmtu = IN6_LINKMTU(ifp);
1542 		ND.maxmtu = ND_IFINFO(ifp)->maxmtu;
1543 		ND.basereachable = ND_IFINFO(ifp)->basereachable;
1544 		ND.reachable = ND_IFINFO(ifp)->reachable;
1545 		ND.retrans = ND_IFINFO(ifp)->retrans;
1546 		ND.flags = ND_IFINFO(ifp)->flags;
1547 		ND.recalctm = ND_IFINFO(ifp)->recalctm;
1548 		ND.chlim = ND_IFINFO(ifp)->chlim;
1549 		break;
1550 	case SIOCGIFINFO_IN6:
1551 		ND = *ND_IFINFO(ifp);
1552 		break;
1553 	case SIOCSIFINFO_IN6:
1554 		/*
1555 		 * used to change host variables from userland.
1556 		 * intented for a use on router to reflect RA configurations.
1557 		 */
1558 		/* 0 means 'unspecified' */
1559 		if (ND.linkmtu != 0) {
1560 			if (ND.linkmtu < IPV6_MMTU ||
1561 			    ND.linkmtu > IN6_LINKMTU(ifp)) {
1562 				error = EINVAL;
1563 				break;
1564 			}
1565 			ND_IFINFO(ifp)->linkmtu = ND.linkmtu;
1566 		}
1567 
1568 		if (ND.basereachable != 0) {
1569 			int obasereachable = ND_IFINFO(ifp)->basereachable;
1570 
1571 			ND_IFINFO(ifp)->basereachable = ND.basereachable;
1572 			if (ND.basereachable != obasereachable)
1573 				ND_IFINFO(ifp)->reachable =
1574 				    ND_COMPUTE_RTIME(ND.basereachable);
1575 		}
1576 		if (ND.retrans != 0)
1577 			ND_IFINFO(ifp)->retrans = ND.retrans;
1578 		if (ND.chlim != 0)
1579 			ND_IFINFO(ifp)->chlim = ND.chlim;
1580 		/* FALLTHROUGH */
1581 	case SIOCSIFINFO_FLAGS:
1582 		ND_IFINFO(ifp)->flags = ND.flags;
1583 		break;
1584 #undef ND
1585 	case SIOCSNDFLUSH_IN6:	/* XXX: the ioctl name is confusing... */
1586 		/* sync kernel routing table with the default router list */
1587 		defrouter_reset();
1588 		defrouter_select();
1589 		break;
1590 	case SIOCSPFXFLUSH_IN6:
1591 	{
1592 		/* flush all the prefix advertised by routers */
1593 		struct nd_prefix *pfx, *next;
1594 
1595 		s = splsoftnet();
1596 		for (pfx = LIST_FIRST(&nd_prefix); pfx; pfx = next) {
1597 			struct in6_ifaddr *ia, *ia_next;
1598 
1599 			next = LIST_NEXT(pfx, ndpr_entry);
1600 
1601 			if (IN6_IS_ADDR_LINKLOCAL(&pfx->ndpr_prefix.sin6_addr))
1602 				continue; /* XXX */
1603 
1604 			/* do we really have to remove addresses as well? */
1605 			for (ia = in6_ifaddr; ia; ia = ia_next) {
1606 				/* ia might be removed.  keep the next ptr. */
1607 				ia_next = ia->ia_next;
1608 
1609 				if ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1610 					continue;
1611 
1612 				if (ia->ia6_ndpr == pfx)
1613 					in6_purgeaddr(&ia->ia_ifa);
1614 			}
1615 			prelist_remove(pfx);
1616 		}
1617 		splx(s);
1618 		break;
1619 	}
1620 	case SIOCSRTRFLUSH_IN6:
1621 	{
1622 		/* flush all the default routers */
1623 		struct nd_defrouter *drtr, *next;
1624 
1625 		s = splsoftnet();
1626 		defrouter_reset();
1627 		for (drtr = TAILQ_FIRST(&nd_defrouter); drtr; drtr = next) {
1628 			next = TAILQ_NEXT(drtr, dr_entry);
1629 			defrtrlist_del(drtr);
1630 		}
1631 		defrouter_select();
1632 		splx(s);
1633 		break;
1634 	}
1635 	case SIOCGNBRINFO_IN6:
1636 	{
1637 		struct llinfo_nd6 *ln;
1638 		struct in6_addr nb_addr = nbi->addr; /* make local for safety */
1639 
1640 		if ((error = in6_setscope(&nb_addr, ifp, NULL)) != 0)
1641 			return error;
1642 
1643 		s = splsoftnet();
1644 		if ((rt = nd6_lookup(&nb_addr, 0, ifp)) == NULL ||
1645 		    (ln = (struct llinfo_nd6 *)rt->rt_llinfo) == NULL) {
1646 			error = EINVAL;
1647 			splx(s);
1648 			break;
1649 		}
1650 		nbi->state = ln->ln_state;
1651 		nbi->asked = ln->ln_asked;
1652 		nbi->isrouter = ln->ln_router;
1653 		nbi->expire = ln->ln_expire;
1654 		splx(s);
1655 
1656 		break;
1657 	}
1658 	case SIOCGDEFIFACE_IN6:	/* XXX: should be implemented as a sysctl? */
1659 		ndif->ifindex = nd6_defifindex;
1660 		break;
1661 	case SIOCSDEFIFACE_IN6:	/* XXX: should be implemented as a sysctl? */
1662 		return nd6_setdefaultiface(ndif->ifindex);
1663 	}
1664 	return error;
1665 }
1666 
1667 void
1668 nd6_llinfo_release_pkts(struct llinfo_nd6 *ln, struct ifnet *ifp,
1669     struct rtentry *rt)
1670 {
1671 	struct mbuf *m_hold, *m_hold_next;
1672 
1673 	for (m_hold = ln->ln_hold, ln->ln_hold = NULL;
1674 	     m_hold != NULL;
1675 	     m_hold = m_hold_next) {
1676 		m_hold_next = m_hold->m_nextpkt;
1677 		m_hold->m_nextpkt = NULL;
1678 
1679 		/*
1680 		 * we assume ifp is not a p2p here, so
1681 		 * just set the 2nd argument as the
1682 		 * 1st one.
1683 		 */
1684 		nd6_output(ifp, ifp, m_hold, satocsin6(rt_getkey(rt)), rt);
1685 	}
1686 }
1687 
1688 /*
1689  * Create neighbor cache entry and cache link-layer address,
1690  * on reception of inbound ND6 packets.  (RS/RA/NS/redirect)
1691  */
1692 struct rtentry *
1693 nd6_cache_lladdr(
1694     struct ifnet *ifp,
1695     struct in6_addr *from,
1696     char *lladdr,
1697     int lladdrlen,
1698     int type,	/* ICMP6 type */
1699     int code	/* type dependent information */
1700 )
1701 {
1702 	struct nd_ifinfo *ndi = ND_IFINFO(ifp);
1703 	struct rtentry *rt = NULL;
1704 	struct llinfo_nd6 *ln = NULL;
1705 	int is_newentry;
1706 	struct sockaddr_dl *sdl = NULL;
1707 	int do_update;
1708 	int olladdr;
1709 	int llchange;
1710 	int newstate = 0;
1711 
1712 	if (ifp == NULL)
1713 		panic("ifp == NULL in nd6_cache_lladdr");
1714 	if (from == NULL)
1715 		panic("from == NULL in nd6_cache_lladdr");
1716 
1717 	/* nothing must be updated for unspecified address */
1718 	if (IN6_IS_ADDR_UNSPECIFIED(from))
1719 		return NULL;
1720 
1721 	/*
1722 	 * Validation about ifp->if_addrlen and lladdrlen must be done in
1723 	 * the caller.
1724 	 *
1725 	 * XXX If the link does not have link-layer adderss, what should
1726 	 * we do? (ifp->if_addrlen == 0)
1727 	 * Spec says nothing in sections for RA, RS and NA.  There's small
1728 	 * description on it in NS section (RFC 2461 7.2.3).
1729 	 */
1730 
1731 	rt = nd6_lookup(from, 0, ifp);
1732 	if (rt == NULL) {
1733 #if 0
1734 		/* nothing must be done if there's no lladdr */
1735 		if (!lladdr || !lladdrlen)
1736 			return NULL;
1737 #endif
1738 
1739 		rt = nd6_lookup(from, 1, ifp);
1740 		is_newentry = 1;
1741 	} else {
1742 		/* do nothing if static ndp is set */
1743 		if (rt->rt_flags & RTF_STATIC)
1744 			return NULL;
1745 		is_newentry = 0;
1746 	}
1747 
1748 	if (rt == NULL)
1749 		return NULL;
1750 	if ((rt->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) != RTF_LLINFO) {
1751 fail:
1752 		(void)nd6_free(rt, 0);
1753 		return NULL;
1754 	}
1755 	ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1756 	if (ln == NULL)
1757 		goto fail;
1758 	if (rt->rt_gateway == NULL)
1759 		goto fail;
1760 	if (rt->rt_gateway->sa_family != AF_LINK)
1761 		goto fail;
1762 	sdl = satosdl(rt->rt_gateway);
1763 
1764 	olladdr = (sdl->sdl_alen) ? 1 : 0;
1765 	if (olladdr && lladdr) {
1766 		if (memcmp(lladdr, CLLADDR(sdl), ifp->if_addrlen))
1767 			llchange = 1;
1768 		else
1769 			llchange = 0;
1770 	} else
1771 		llchange = 0;
1772 
1773 	/*
1774 	 * newentry olladdr  lladdr  llchange	(*=record)
1775 	 *	0	n	n	--	(1)
1776 	 *	0	y	n	--	(2)
1777 	 *	0	n	y	--	(3) * STALE
1778 	 *	0	y	y	n	(4) *
1779 	 *	0	y	y	y	(5) * STALE
1780 	 *	1	--	n	--	(6)   NOSTATE(= PASSIVE)
1781 	 *	1	--	y	--	(7) * STALE
1782 	 */
1783 
1784 	if (lladdr) {		/* (3-5) and (7) */
1785 		/*
1786 		 * Record source link-layer address
1787 		 * XXX is it dependent to ifp->if_type?
1788 		 */
1789 		/* XXX check for error */
1790 		if (sockaddr_dl_setaddr(sdl, sdl->sdl_len, lladdr,
1791 		    ifp->if_addrlen) == NULL) {
1792 			printf("%s.%d: sockaddr_dl_setaddr(, %d, ) "
1793 			    "failed on %s\n", __func__, __LINE__,
1794 			    sdl->sdl_len, if_name(ifp));
1795 		}
1796 	}
1797 
1798 	if (!is_newentry) {
1799 		if ((!olladdr && lladdr) ||		/* (3) */
1800 		    (olladdr && lladdr && llchange)) {	/* (5) */
1801 			do_update = 1;
1802 			newstate = ND6_LLINFO_STALE;
1803 		} else					/* (1-2,4) */
1804 			do_update = 0;
1805 	} else {
1806 		do_update = 1;
1807 		if (lladdr == NULL)			/* (6) */
1808 			newstate = ND6_LLINFO_NOSTATE;
1809 		else					/* (7) */
1810 			newstate = ND6_LLINFO_STALE;
1811 	}
1812 
1813 	if (do_update) {
1814 		/*
1815 		 * Update the state of the neighbor cache.
1816 		 */
1817 		ln->ln_state = newstate;
1818 
1819 		if (ln->ln_state == ND6_LLINFO_STALE) {
1820 			/*
1821 			 * XXX: since nd6_output() below will cause
1822 			 * state tansition to DELAY and reset the timer,
1823 			 * we must set the timer now, although it is actually
1824 			 * meaningless.
1825 			 */
1826 			nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz);
1827 
1828 			nd6_llinfo_release_pkts(ln, ifp, rt);
1829 		} else if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
1830 			/* probe right away */
1831 			nd6_llinfo_settimer((void *)ln, 0);
1832 		}
1833 	}
1834 
1835 	/*
1836 	 * ICMP6 type dependent behavior.
1837 	 *
1838 	 * NS: clear IsRouter if new entry
1839 	 * RS: clear IsRouter
1840 	 * RA: set IsRouter if there's lladdr
1841 	 * redir: clear IsRouter if new entry
1842 	 *
1843 	 * RA case, (1):
1844 	 * The spec says that we must set IsRouter in the following cases:
1845 	 * - If lladdr exist, set IsRouter.  This means (1-5).
1846 	 * - If it is old entry (!newentry), set IsRouter.  This means (7).
1847 	 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
1848 	 * A quetion arises for (1) case.  (1) case has no lladdr in the
1849 	 * neighbor cache, this is similar to (6).
1850 	 * This case is rare but we figured that we MUST NOT set IsRouter.
1851 	 *
1852 	 * newentry olladdr  lladdr  llchange	    NS  RS  RA	redir
1853 	 *							D R
1854 	 *	0	n	n	--	(1)	c   ?     s
1855 	 *	0	y	n	--	(2)	c   s     s
1856 	 *	0	n	y	--	(3)	c   s     s
1857 	 *	0	y	y	n	(4)	c   s     s
1858 	 *	0	y	y	y	(5)	c   s     s
1859 	 *	1	--	n	--	(6) c	c 	c s
1860 	 *	1	--	y	--	(7) c	c   s	c s
1861 	 *
1862 	 *					(c=clear s=set)
1863 	 */
1864 	switch (type & 0xff) {
1865 	case ND_NEIGHBOR_SOLICIT:
1866 		/*
1867 		 * New entry must have is_router flag cleared.
1868 		 */
1869 		if (is_newentry)	/* (6-7) */
1870 			ln->ln_router = 0;
1871 		break;
1872 	case ND_REDIRECT:
1873 		/*
1874 		 * If the icmp is a redirect to a better router, always set the
1875 		 * is_router flag.  Otherwise, if the entry is newly created,
1876 		 * clear the flag.  [RFC 2461, sec 8.3]
1877 		 */
1878 		if (code == ND_REDIRECT_ROUTER)
1879 			ln->ln_router = 1;
1880 		else if (is_newentry) /* (6-7) */
1881 			ln->ln_router = 0;
1882 		break;
1883 	case ND_ROUTER_SOLICIT:
1884 		/*
1885 		 * is_router flag must always be cleared.
1886 		 */
1887 		ln->ln_router = 0;
1888 		break;
1889 	case ND_ROUTER_ADVERT:
1890 		/*
1891 		 * Mark an entry with lladdr as a router.
1892 		 */
1893 		if ((!is_newentry && (olladdr || lladdr)) ||	/* (2-5) */
1894 		    (is_newentry && lladdr)) {			/* (7) */
1895 			ln->ln_router = 1;
1896 		}
1897 		break;
1898 	}
1899 
1900 	/*
1901 	 * When the link-layer address of a router changes, select the
1902 	 * best router again.  In particular, when the neighbor entry is newly
1903 	 * created, it might affect the selection policy.
1904 	 * Question: can we restrict the first condition to the "is_newentry"
1905 	 * case?
1906 	 * XXX: when we hear an RA from a new router with the link-layer
1907 	 * address option, defrouter_select() is called twice, since
1908 	 * defrtrlist_update called the function as well.  However, I believe
1909 	 * we can compromise the overhead, since it only happens the first
1910 	 * time.
1911 	 * XXX: although defrouter_select() should not have a bad effect
1912 	 * for those are not autoconfigured hosts, we explicitly avoid such
1913 	 * cases for safety.
1914 	 */
1915 	if (do_update && ln->ln_router && !ip6_forwarding &&
1916 	    nd6_accepts_rtadv(ndi))
1917 		defrouter_select();
1918 
1919 	return rt;
1920 }
1921 
1922 static void
1923 nd6_slowtimo(void *ignored_arg)
1924 {
1925 	struct nd_ifinfo *nd6if;
1926 	struct ifnet *ifp;
1927 
1928 	mutex_enter(softnet_lock);
1929 	KERNEL_LOCK(1, NULL);
1930       	callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
1931 	    nd6_slowtimo, NULL);
1932 	TAILQ_FOREACH(ifp, &ifnet, if_list) {
1933 		nd6if = ND_IFINFO(ifp);
1934 		if (nd6if->basereachable && /* already initialized */
1935 		    (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
1936 			/*
1937 			 * Since reachable time rarely changes by router
1938 			 * advertisements, we SHOULD insure that a new random
1939 			 * value gets recomputed at least once every few hours.
1940 			 * (RFC 2461, 6.3.4)
1941 			 */
1942 			nd6if->recalctm = nd6_recalc_reachtm_interval;
1943 			nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable);
1944 		}
1945 	}
1946 	KERNEL_UNLOCK_ONE(NULL);
1947 	mutex_exit(softnet_lock);
1948 }
1949 
1950 #define senderr(e) { error = (e); goto bad;}
1951 int
1952 nd6_output(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m0,
1953     const struct sockaddr_in6 *dst, struct rtentry *rt0)
1954 {
1955 	struct mbuf *m = m0;
1956 	struct rtentry *rt = rt0;
1957 	struct sockaddr_in6 *gw6 = NULL;
1958 	struct llinfo_nd6 *ln = NULL;
1959 	int error = 0;
1960 
1961 	if (IN6_IS_ADDR_MULTICAST(&dst->sin6_addr))
1962 		goto sendpkt;
1963 
1964 	if (nd6_need_cache(ifp) == 0)
1965 		goto sendpkt;
1966 
1967 	/*
1968 	 * next hop determination.  This routine is derived from ether_output.
1969 	 */
1970 	if (rt) {
1971 		if ((rt->rt_flags & RTF_UP) == 0) {
1972 			if ((rt0 = rt = rtalloc1(sin6tocsa(dst), 1)) != NULL) {
1973 				rt->rt_refcnt--;
1974 				if (rt->rt_ifp != ifp)
1975 					senderr(EHOSTUNREACH);
1976 			} else
1977 				senderr(EHOSTUNREACH);
1978 		}
1979 
1980 		if (rt->rt_flags & RTF_GATEWAY) {
1981 			gw6 = (struct sockaddr_in6 *)rt->rt_gateway;
1982 
1983 			/*
1984 			 * We skip link-layer address resolution and NUD
1985 			 * if the gateway is not a neighbor from ND point
1986 			 * of view, regardless of the value of nd_ifinfo.flags.
1987 			 * The second condition is a bit tricky; we skip
1988 			 * if the gateway is our own address, which is
1989 			 * sometimes used to install a route to a p2p link.
1990 			 */
1991 			if (!nd6_is_addr_neighbor(gw6, ifp) ||
1992 			    in6ifa_ifpwithaddr(ifp, &gw6->sin6_addr)) {
1993 				/*
1994 				 * We allow this kind of tricky route only
1995 				 * when the outgoing interface is p2p.
1996 				 * XXX: we may need a more generic rule here.
1997 				 */
1998 				if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
1999 					senderr(EHOSTUNREACH);
2000 
2001 				goto sendpkt;
2002 			}
2003 
2004 			if (rt->rt_gwroute == NULL)
2005 				goto lookup;
2006 			if (((rt = rt->rt_gwroute)->rt_flags & RTF_UP) == 0) {
2007 				rtfree(rt); rt = rt0;
2008 			lookup:
2009 				rt->rt_gwroute = rtalloc1(rt->rt_gateway, 1);
2010 				if ((rt = rt->rt_gwroute) == NULL)
2011 					senderr(EHOSTUNREACH);
2012 				/* the "G" test below also prevents rt == rt0 */
2013 				if ((rt->rt_flags & RTF_GATEWAY) ||
2014 				    (rt->rt_ifp != ifp)) {
2015 					rt->rt_refcnt--;
2016 					rt0->rt_gwroute = NULL;
2017 					senderr(EHOSTUNREACH);
2018 				}
2019 			}
2020 		}
2021 	}
2022 
2023 	/*
2024 	 * Address resolution or Neighbor Unreachability Detection
2025 	 * for the next hop.
2026 	 * At this point, the destination of the packet must be a unicast
2027 	 * or an anycast address(i.e. not a multicast).
2028 	 */
2029 
2030 	/* Look up the neighbor cache for the nexthop */
2031 	if (rt != NULL && (rt->rt_flags & RTF_LLINFO) != 0)
2032 		ln = (struct llinfo_nd6 *)rt->rt_llinfo;
2033 	else {
2034 		/*
2035 		 * Since nd6_is_addr_neighbor() internally calls nd6_lookup(),
2036 		 * the condition below is not very efficient.  But we believe
2037 		 * it is tolerable, because this should be a rare case.
2038 		 */
2039 		if (nd6_is_addr_neighbor(dst, ifp) &&
2040 		    (rt = nd6_lookup(&dst->sin6_addr, 1, ifp)) != NULL)
2041 			ln = (struct llinfo_nd6 *)rt->rt_llinfo;
2042 	}
2043 	if (ln == NULL || rt == NULL) {
2044 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0 &&
2045 		    !(ND_IFINFO(ifp)->flags & ND6_IFF_PERFORMNUD)) {
2046 			log(LOG_DEBUG,
2047 			    "nd6_output: can't allocate llinfo for %s "
2048 			    "(ln=%p, rt=%p)\n",
2049 			    ip6_sprintf(&dst->sin6_addr), ln, rt);
2050 			senderr(EIO);	/* XXX: good error? */
2051 		}
2052 
2053 		goto sendpkt;	/* send anyway */
2054 	}
2055 
2056 	/* We don't have to do link-layer address resolution on a p2p link. */
2057 	if ((ifp->if_flags & IFF_POINTOPOINT) != 0 &&
2058 	    ln->ln_state < ND6_LLINFO_REACHABLE) {
2059 		ln->ln_state = ND6_LLINFO_STALE;
2060 		nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz);
2061 	}
2062 
2063 	/*
2064 	 * The first time we send a packet to a neighbor whose entry is
2065 	 * STALE, we have to change the state to DELAY and a sets a timer to
2066 	 * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do
2067 	 * neighbor unreachability detection on expiration.
2068 	 * (RFC 2461 7.3.3)
2069 	 */
2070 	if (ln->ln_state == ND6_LLINFO_STALE) {
2071 		ln->ln_asked = 0;
2072 		ln->ln_state = ND6_LLINFO_DELAY;
2073 		nd6_llinfo_settimer(ln, (long)nd6_delay * hz);
2074 	}
2075 
2076 	/*
2077 	 * If the neighbor cache entry has a state other than INCOMPLETE
2078 	 * (i.e. its link-layer address is already resolved), just
2079 	 * send the packet.
2080 	 */
2081 	if (ln->ln_state > ND6_LLINFO_INCOMPLETE)
2082 		goto sendpkt;
2083 
2084 	/*
2085 	 * There is a neighbor cache entry, but no ethernet address
2086 	 * response yet.  Append this latest packet to the end of the
2087 	 * packet queue in the mbuf, unless the number of the packet
2088 	 * does not exceed nd6_maxqueuelen.  When it exceeds nd6_maxqueuelen,
2089 	 * the oldest packet in the queue will be removed.
2090 	 */
2091 	if (ln->ln_state == ND6_LLINFO_NOSTATE)
2092 		ln->ln_state = ND6_LLINFO_INCOMPLETE;
2093 	if (ln->ln_hold) {
2094 		struct mbuf *m_hold;
2095 		int i;
2096 
2097 		i = 0;
2098 		for (m_hold = ln->ln_hold; m_hold; m_hold = m_hold->m_nextpkt) {
2099 			i++;
2100 			if (m_hold->m_nextpkt == NULL) {
2101 				m_hold->m_nextpkt = m;
2102 				break;
2103 			}
2104 		}
2105 		while (i >= nd6_maxqueuelen) {
2106 			m_hold = ln->ln_hold;
2107 			ln->ln_hold = ln->ln_hold->m_nextpkt;
2108 			m_freem(m_hold);
2109 			i--;
2110 		}
2111 	} else {
2112 		ln->ln_hold = m;
2113 	}
2114 
2115 	/*
2116 	 * If there has been no NS for the neighbor after entering the
2117 	 * INCOMPLETE state, send the first solicitation.
2118 	 */
2119 	if (!ND6_LLINFO_PERMANENT(ln) && ln->ln_asked == 0) {
2120 		ln->ln_asked++;
2121 		nd6_llinfo_settimer(ln,
2122 		    (long)ND_IFINFO(ifp)->retrans * hz / 1000);
2123 		nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0);
2124 	}
2125 	return 0;
2126 
2127   sendpkt:
2128 	/* discard the packet if IPv6 operation is disabled on the interface */
2129 	if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED)) {
2130 		error = ENETDOWN; /* better error? */
2131 		goto bad;
2132 	}
2133 
2134 #ifdef KAME_IPSEC
2135 	/* clean ipsec history once it goes out of the node */
2136 	ipsec_delaux(m);
2137 #endif
2138 	if ((ifp->if_flags & IFF_LOOPBACK) != 0)
2139 		return (*ifp->if_output)(origifp, m, sin6tocsa(dst), rt);
2140 	return (*ifp->if_output)(ifp, m, sin6tocsa(dst), rt);
2141 
2142   bad:
2143 	if (m != NULL)
2144 		m_freem(m);
2145 	return error;
2146 }
2147 #undef senderr
2148 
2149 int
2150 nd6_need_cache(struct ifnet *ifp)
2151 {
2152 	/*
2153 	 * XXX: we currently do not make neighbor cache on any interface
2154 	 * other than ARCnet, Ethernet, FDDI and GIF.
2155 	 *
2156 	 * RFC2893 says:
2157 	 * - unidirectional tunnels needs no ND
2158 	 */
2159 	switch (ifp->if_type) {
2160 	case IFT_ARCNET:
2161 	case IFT_ETHER:
2162 	case IFT_FDDI:
2163 	case IFT_IEEE1394:
2164 	case IFT_CARP:
2165 	case IFT_GIF:		/* XXX need more cases? */
2166 	case IFT_PPP:
2167 	case IFT_TUNNEL:
2168 		return 1;
2169 	default:
2170 		return 0;
2171 	}
2172 }
2173 
2174 int
2175 nd6_storelladdr(const struct ifnet *ifp, const struct rtentry *rt,
2176     struct mbuf *m, const struct sockaddr *dst, uint8_t *lldst,
2177     size_t dstsize)
2178 {
2179 	const struct sockaddr_dl *sdl;
2180 
2181 	if (m->m_flags & M_MCAST) {
2182 		switch (ifp->if_type) {
2183 		case IFT_ETHER:
2184 		case IFT_FDDI:
2185 			ETHER_MAP_IPV6_MULTICAST(&satocsin6(dst)->sin6_addr,
2186 			    lldst);
2187 			return 1;
2188 		case IFT_IEEE1394:
2189 			memcpy(lldst, ifp->if_broadcastaddr,
2190 			    MIN(dstsize, ifp->if_addrlen));
2191 			return 1;
2192 		case IFT_ARCNET:
2193 			*lldst = 0;
2194 			return 1;
2195 		default:
2196 			m_freem(m);
2197 			return 0;
2198 		}
2199 	}
2200 
2201 	if (rt == NULL) {
2202 		/* this could happen, if we could not allocate memory */
2203 		m_freem(m);
2204 		return 0;
2205 	}
2206 	if (rt->rt_gateway->sa_family != AF_LINK) {
2207 		printf("%s: something odd happens\n", __func__);
2208 		m_freem(m);
2209 		return 0;
2210 	}
2211 	sdl = satocsdl(rt->rt_gateway);
2212 	if (sdl->sdl_alen == 0 || sdl->sdl_alen > dstsize) {
2213 		/* this should be impossible, but we bark here for debugging */
2214 		printf("%s: sdl_alen == %" PRIu8 ", dst=%s, if=%s\n", __func__,
2215 		    sdl->sdl_alen, ip6_sprintf(&satocsin6(dst)->sin6_addr),
2216 		    if_name(ifp));
2217 		m_freem(m);
2218 		return 0;
2219 	}
2220 
2221 	memcpy(lldst, CLLADDR(sdl), MIN(dstsize, sdl->sdl_alen));
2222 	return 1;
2223 }
2224 
2225 static void
2226 clear_llinfo_pqueue(struct llinfo_nd6 *ln)
2227 {
2228 	struct mbuf *m_hold, *m_hold_next;
2229 
2230 	for (m_hold = ln->ln_hold; m_hold; m_hold = m_hold_next) {
2231 		m_hold_next = m_hold->m_nextpkt;
2232 		m_hold->m_nextpkt = NULL;
2233 		m_freem(m_hold);
2234 	}
2235 
2236 	ln->ln_hold = NULL;
2237 	return;
2238 }
2239 
2240 int
2241 nd6_sysctl(
2242     int name,
2243     void *oldp,	/* syscall arg, need copyout */
2244     size_t *oldlenp,
2245     void *newp,	/* syscall arg, need copyin */
2246     size_t newlen
2247 )
2248 {
2249 	void *p;
2250 	size_t ol;
2251 	int error;
2252 
2253 	error = 0;
2254 
2255 	if (newp)
2256 		return EPERM;
2257 	if (oldp && !oldlenp)
2258 		return EINVAL;
2259 	ol = oldlenp ? *oldlenp : 0;
2260 
2261 	if (oldp) {
2262 		p = malloc(*oldlenp, M_TEMP, M_WAITOK);
2263 		if (p == NULL)
2264 			return ENOMEM;
2265 	} else
2266 		p = NULL;
2267 	switch (name) {
2268 	case ICMPV6CTL_ND6_DRLIST:
2269 		error = fill_drlist(p, oldlenp, ol);
2270 		if (!error && p != NULL && oldp != NULL)
2271 			error = copyout(p, oldp, *oldlenp);
2272 		break;
2273 
2274 	case ICMPV6CTL_ND6_PRLIST:
2275 		error = fill_prlist(p, oldlenp, ol);
2276 		if (!error && p != NULL && oldp != NULL)
2277 			error = copyout(p, oldp, *oldlenp);
2278 		break;
2279 
2280 	case ICMPV6CTL_ND6_MAXQLEN:
2281 		break;
2282 
2283 	default:
2284 		error = ENOPROTOOPT;
2285 		break;
2286 	}
2287 	if (p)
2288 		free(p, M_TEMP);
2289 
2290 	return error;
2291 }
2292 
2293 static int
2294 fill_drlist(void *oldp, size_t *oldlenp, size_t ol)
2295 {
2296 	int error = 0, s;
2297 	struct in6_defrouter *d = NULL, *de = NULL;
2298 	struct nd_defrouter *dr;
2299 	size_t l;
2300 
2301 	s = splsoftnet();
2302 
2303 	if (oldp) {
2304 		d = (struct in6_defrouter *)oldp;
2305 		de = (struct in6_defrouter *)((char *)oldp + *oldlenp);
2306 	}
2307 	l = 0;
2308 
2309 	TAILQ_FOREACH(dr, &nd_defrouter, dr_entry) {
2310 
2311 		if (oldp && d + 1 <= de) {
2312 			memset(d, 0, sizeof(*d));
2313 			sockaddr_in6_init(&d->rtaddr, &dr->rtaddr, 0, 0, 0);
2314 			if (sa6_recoverscope(&d->rtaddr)) {
2315 				log(LOG_ERR,
2316 				    "scope error in router list (%s)\n",
2317 				    ip6_sprintf(&d->rtaddr.sin6_addr));
2318 				/* XXX: press on... */
2319 			}
2320 			d->flags = dr->flags;
2321 			d->rtlifetime = dr->rtlifetime;
2322 			d->expire = dr->expire;
2323 			d->if_index = dr->ifp->if_index;
2324 		}
2325 
2326 		l += sizeof(*d);
2327 		if (d)
2328 			d++;
2329 	}
2330 
2331 	if (oldp) {
2332 		if (l > ol)
2333 			error = ENOMEM;
2334 	}
2335 	if (oldlenp)
2336 		*oldlenp = l;	/* (void *)d - (void *)oldp */
2337 
2338 	splx(s);
2339 
2340 	return error;
2341 }
2342 
2343 static int
2344 fill_prlist(void *oldp, size_t *oldlenp, size_t ol)
2345 {
2346 	int error = 0, s;
2347 	struct nd_prefix *pr;
2348 	struct in6_prefix *p = NULL;
2349 	struct in6_prefix *pe = NULL;
2350 	size_t l;
2351 
2352 	s = splsoftnet();
2353 
2354 	if (oldp) {
2355 		p = (struct in6_prefix *)oldp;
2356 		pe = (struct in6_prefix *)((char *)oldp + *oldlenp);
2357 	}
2358 	l = 0;
2359 
2360 	LIST_FOREACH(pr, &nd_prefix, ndpr_entry) {
2361 		u_short advrtrs;
2362 		size_t advance;
2363 		struct sockaddr_in6 *sin6;
2364 		struct sockaddr_in6 *s6;
2365 		struct nd_pfxrouter *pfr;
2366 
2367 		if (oldp && p + 1 <= pe)
2368 		{
2369 			memset(p, 0, sizeof(*p));
2370 			sin6 = (struct sockaddr_in6 *)(p + 1);
2371 
2372 			p->prefix = pr->ndpr_prefix;
2373 			if (sa6_recoverscope(&p->prefix)) {
2374 				log(LOG_ERR,
2375 				    "scope error in prefix list (%s)\n",
2376 				    ip6_sprintf(&p->prefix.sin6_addr));
2377 				/* XXX: press on... */
2378 			}
2379 			p->raflags = pr->ndpr_raf;
2380 			p->prefixlen = pr->ndpr_plen;
2381 			p->vltime = pr->ndpr_vltime;
2382 			p->pltime = pr->ndpr_pltime;
2383 			p->if_index = pr->ndpr_ifp->if_index;
2384 			if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME)
2385 				p->expire = 0;
2386 			else {
2387 				time_t maxexpire;
2388 
2389 				/* XXX: we assume time_t is signed. */
2390 				maxexpire = (-1) &
2391 				    ~((time_t)1 <<
2392 				    ((sizeof(maxexpire) * 8) - 1));
2393 				if (pr->ndpr_vltime <
2394 				    maxexpire - pr->ndpr_lastupdate) {
2395 					p->expire = pr->ndpr_lastupdate +
2396 						pr->ndpr_vltime;
2397 				} else
2398 					p->expire = maxexpire;
2399 			}
2400 			p->refcnt = pr->ndpr_refcnt;
2401 			p->flags = pr->ndpr_stateflags;
2402 			p->origin = PR_ORIG_RA;
2403 			advrtrs = 0;
2404 			LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) {
2405 				if ((void *)&sin6[advrtrs + 1] > (void *)pe) {
2406 					advrtrs++;
2407 					continue;
2408 				}
2409 				s6 = &sin6[advrtrs];
2410 				sockaddr_in6_init(s6, &pfr->router->rtaddr,
2411 				    0, 0, 0);
2412 				if (sa6_recoverscope(s6)) {
2413 					log(LOG_ERR,
2414 					    "scope error in "
2415 					    "prefix list (%s)\n",
2416 					    ip6_sprintf(&pfr->router->rtaddr));
2417 				}
2418 				advrtrs++;
2419 			}
2420 			p->advrtrs = advrtrs;
2421 		}
2422 		else {
2423 			advrtrs = 0;
2424 			LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry)
2425 				advrtrs++;
2426 		}
2427 
2428 		advance = sizeof(*p) + sizeof(*sin6) * advrtrs;
2429 		l += advance;
2430 		if (p)
2431 			p = (struct in6_prefix *)((char *)p + advance);
2432 	}
2433 
2434 	if (oldp) {
2435 		*oldlenp = l;	/* (void *)d - (void *)oldp */
2436 		if (l > ol)
2437 			error = ENOMEM;
2438 	} else
2439 		*oldlenp = l;
2440 
2441 	splx(s);
2442 
2443 	return error;
2444 }
2445