xref: /netbsd-src/sys/netinet6/nd6.c (revision a24efa7dea9f1f56c3bdb15a927d3516792ace1c)
1 /*	$NetBSD: nd6.c,v 1.195 2016/05/18 11:28:44 ozaki-r 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 1.195 2016/05/18 11:28:44 ozaki-r Exp $");
35 
36 #ifdef _KERNEL_OPT
37 #include "opt_net_mpsafe.h"
38 #endif
39 
40 #include "bridge.h"
41 #include "carp.h"
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/callout.h>
46 #include <sys/malloc.h>
47 #include <sys/mbuf.h>
48 #include <sys/socket.h>
49 #include <sys/socketvar.h>
50 #include <sys/sockio.h>
51 #include <sys/time.h>
52 #include <sys/kernel.h>
53 #include <sys/protosw.h>
54 #include <sys/errno.h>
55 #include <sys/ioctl.h>
56 #include <sys/syslog.h>
57 #include <sys/queue.h>
58 #include <sys/cprng.h>
59 
60 #include <net/if.h>
61 #include <net/if_dl.h>
62 #include <net/if_llatbl.h>
63 #include <net/if_types.h>
64 #include <net/route.h>
65 #include <net/if_ether.h>
66 #include <net/if_fddi.h>
67 #include <net/if_arc.h>
68 
69 #include <netinet/in.h>
70 #include <netinet6/in6_var.h>
71 #include <netinet/ip6.h>
72 #include <netinet6/ip6_var.h>
73 #include <netinet6/scope6_var.h>
74 #include <netinet6/nd6.h>
75 #include <netinet6/in6_ifattach.h>
76 #include <netinet/icmp6.h>
77 #include <netinet6/icmp6_private.h>
78 
79 #include <net/net_osdep.h>
80 
81 #define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */
82 #define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */
83 
84 /* timer values */
85 int	nd6_prune	= 1;	/* walk list every 1 seconds */
86 int	nd6_delay	= 5;	/* delay first probe time 5 second */
87 int	nd6_umaxtries	= 3;	/* maximum unicast query */
88 int	nd6_mmaxtries	= 3;	/* maximum multicast query */
89 int	nd6_useloopback = 1;	/* use loopback interface for local traffic */
90 int	nd6_gctimer	= (60 * 60 * 24); /* 1 day: garbage collection timer */
91 
92 /* preventing too many loops in ND option parsing */
93 int nd6_maxndopt = 10;	/* max # of ND options allowed */
94 
95 int nd6_maxnudhint = 0;	/* max # of subsequent upper layer hints */
96 
97 int nd6_maxqueuelen = 1; /* max # of packets cached in unresolved ND entries */
98 
99 #ifdef ND6_DEBUG
100 int nd6_debug = 1;
101 #else
102 int nd6_debug = 0;
103 #endif
104 
105 struct nd_drhead nd_defrouter;
106 struct nd_prhead nd_prefix = { 0 };
107 
108 int nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL;
109 
110 static void nd6_setmtu0(struct ifnet *, struct nd_ifinfo *);
111 static void nd6_slowtimo(void *);
112 static int regen_tmpaddr(struct in6_ifaddr *);
113 static void nd6_free(struct llentry *, int);
114 static void nd6_llinfo_timer(void *);
115 static void nd6_timer(void *);
116 static void clear_llinfo_pqueue(struct llentry *);
117 
118 static callout_t nd6_slowtimo_ch;
119 static callout_t nd6_timer_ch;
120 
121 static int fill_drlist(void *, size_t *, size_t);
122 static int fill_prlist(void *, size_t *, size_t);
123 
124 MALLOC_DEFINE(M_IP6NDP, "NDP", "IPv6 Neighbour Discovery");
125 
126 void
127 nd6_init(void)
128 {
129 
130 	/* initialization of the default router list */
131 	TAILQ_INIT(&nd_defrouter);
132 
133 	callout_init(&nd6_slowtimo_ch, CALLOUT_MPSAFE);
134 	callout_init(&nd6_timer_ch, CALLOUT_MPSAFE);
135 
136 	/* start timer */
137 	callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
138 	    nd6_slowtimo, NULL);
139 	callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL);
140 }
141 
142 struct nd_ifinfo *
143 nd6_ifattach(struct ifnet *ifp)
144 {
145 	struct nd_ifinfo *nd;
146 
147 	nd = (struct nd_ifinfo *)malloc(sizeof(*nd), M_IP6NDP, M_WAITOK|M_ZERO);
148 
149 	nd->initialized = 1;
150 
151 	nd->chlim = IPV6_DEFHLIM;
152 	nd->basereachable = REACHABLE_TIME;
153 	nd->reachable = ND_COMPUTE_RTIME(nd->basereachable);
154 	nd->retrans = RETRANS_TIMER;
155 
156 	nd->flags = ND6_IFF_PERFORMNUD | ND6_IFF_ACCEPT_RTADV;
157 
158 	/* A loopback interface always has ND6_IFF_AUTO_LINKLOCAL.
159 	 * A bridge interface should not have ND6_IFF_AUTO_LINKLOCAL
160 	 * because one of its members should. */
161 	if ((ip6_auto_linklocal && ifp->if_type != IFT_BRIDGE) ||
162 	    (ifp->if_flags & IFF_LOOPBACK))
163 		nd->flags |= ND6_IFF_AUTO_LINKLOCAL;
164 
165 	/* A loopback interface does not need to accept RTADV.
166 	 * A bridge interface should not accept RTADV
167 	 * because one of its members should. */
168 	if (ip6_accept_rtadv &&
169 	    !(ifp->if_flags & IFF_LOOPBACK) &&
170 	    !(ifp->if_type != IFT_BRIDGE))
171 		nd->flags |= ND6_IFF_ACCEPT_RTADV;
172 
173 	/* XXX: we cannot call nd6_setmtu since ifp is not fully initialized */
174 	nd6_setmtu0(ifp, nd);
175 
176 	return nd;
177 }
178 
179 void
180 nd6_ifdetach(struct ifnet *ifp, struct in6_ifextra *ext)
181 {
182 
183 	nd6_purge(ifp, ext);
184 	free(ext->nd_ifinfo, M_IP6NDP);
185 }
186 
187 void
188 nd6_setmtu(struct ifnet *ifp)
189 {
190 	nd6_setmtu0(ifp, ND_IFINFO(ifp));
191 }
192 
193 void
194 nd6_setmtu0(struct ifnet *ifp, struct nd_ifinfo *ndi)
195 {
196 	u_int32_t omaxmtu;
197 
198 	omaxmtu = ndi->maxmtu;
199 
200 	switch (ifp->if_type) {
201 	case IFT_ARCNET:
202 		ndi->maxmtu = MIN(ARC_PHDS_MAXMTU, ifp->if_mtu); /* RFC2497 */
203 		break;
204 	case IFT_FDDI:
205 		ndi->maxmtu = MIN(FDDIIPMTU, ifp->if_mtu);
206 		break;
207 	default:
208 		ndi->maxmtu = ifp->if_mtu;
209 		break;
210 	}
211 
212 	/*
213 	 * Decreasing the interface MTU under IPV6 minimum MTU may cause
214 	 * undesirable situation.  We thus notify the operator of the change
215 	 * explicitly.  The check for omaxmtu is necessary to restrict the
216 	 * log to the case of changing the MTU, not initializing it.
217 	 */
218 	if (omaxmtu >= IPV6_MMTU && ndi->maxmtu < IPV6_MMTU) {
219 		log(LOG_NOTICE, "nd6_setmtu0: new link MTU on %s (%lu) is too"
220 		    " small for IPv6 which needs %lu\n",
221 		    if_name(ifp), (unsigned long)ndi->maxmtu, (unsigned long)
222 		    IPV6_MMTU);
223 	}
224 
225 	if (ndi->maxmtu > in6_maxmtu)
226 		in6_setmaxmtu(); /* check all interfaces just in case */
227 }
228 
229 void
230 nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts)
231 {
232 
233 	memset(ndopts, 0, sizeof(*ndopts));
234 	ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
235 	ndopts->nd_opts_last
236 		= (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len);
237 
238 	if (icmp6len == 0) {
239 		ndopts->nd_opts_done = 1;
240 		ndopts->nd_opts_search = NULL;
241 	}
242 }
243 
244 /*
245  * Take one ND option.
246  */
247 struct nd_opt_hdr *
248 nd6_option(union nd_opts *ndopts)
249 {
250 	struct nd_opt_hdr *nd_opt;
251 	int olen;
252 
253 	KASSERT(ndopts != NULL);
254 	KASSERT(ndopts->nd_opts_last != NULL);
255 
256 	if (ndopts->nd_opts_search == NULL)
257 		return NULL;
258 	if (ndopts->nd_opts_done)
259 		return NULL;
260 
261 	nd_opt = ndopts->nd_opts_search;
262 
263 	/* make sure nd_opt_len is inside the buffer */
264 	if ((void *)&nd_opt->nd_opt_len >= (void *)ndopts->nd_opts_last) {
265 		memset(ndopts, 0, sizeof(*ndopts));
266 		return NULL;
267 	}
268 
269 	olen = nd_opt->nd_opt_len << 3;
270 	if (olen == 0) {
271 		/*
272 		 * Message validation requires that all included
273 		 * options have a length that is greater than zero.
274 		 */
275 		memset(ndopts, 0, sizeof(*ndopts));
276 		return NULL;
277 	}
278 
279 	ndopts->nd_opts_search = (struct nd_opt_hdr *)((char *)nd_opt + olen);
280 	if (ndopts->nd_opts_search > ndopts->nd_opts_last) {
281 		/* option overruns the end of buffer, invalid */
282 		memset(ndopts, 0, sizeof(*ndopts));
283 		return NULL;
284 	} else if (ndopts->nd_opts_search == ndopts->nd_opts_last) {
285 		/* reached the end of options chain */
286 		ndopts->nd_opts_done = 1;
287 		ndopts->nd_opts_search = NULL;
288 	}
289 	return nd_opt;
290 }
291 
292 /*
293  * Parse multiple ND options.
294  * This function is much easier to use, for ND routines that do not need
295  * multiple options of the same type.
296  */
297 int
298 nd6_options(union nd_opts *ndopts)
299 {
300 	struct nd_opt_hdr *nd_opt;
301 	int i = 0;
302 
303 	KASSERT(ndopts != NULL);
304 	KASSERT(ndopts->nd_opts_last != NULL);
305 
306 	if (ndopts->nd_opts_search == NULL)
307 		return 0;
308 
309 	while (1) {
310 		nd_opt = nd6_option(ndopts);
311 		if (nd_opt == NULL && ndopts->nd_opts_last == NULL) {
312 			/*
313 			 * Message validation requires that all included
314 			 * options have a length that is greater than zero.
315 			 */
316 			ICMP6_STATINC(ICMP6_STAT_ND_BADOPT);
317 			memset(ndopts, 0, sizeof(*ndopts));
318 			return -1;
319 		}
320 
321 		if (nd_opt == NULL)
322 			goto skip1;
323 
324 		switch (nd_opt->nd_opt_type) {
325 		case ND_OPT_SOURCE_LINKADDR:
326 		case ND_OPT_TARGET_LINKADDR:
327 		case ND_OPT_MTU:
328 		case ND_OPT_REDIRECTED_HEADER:
329 			if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
330 				nd6log(LOG_INFO,
331 				    "duplicated ND6 option found (type=%d)\n",
332 				    nd_opt->nd_opt_type);
333 				/* XXX bark? */
334 			} else {
335 				ndopts->nd_opt_array[nd_opt->nd_opt_type]
336 					= nd_opt;
337 			}
338 			break;
339 		case ND_OPT_PREFIX_INFORMATION:
340 			if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
341 				ndopts->nd_opt_array[nd_opt->nd_opt_type]
342 					= nd_opt;
343 			}
344 			ndopts->nd_opts_pi_end =
345 				(struct nd_opt_prefix_info *)nd_opt;
346 			break;
347 		default:
348 			/*
349 			 * Unknown options must be silently ignored,
350 			 * to accommodate future extension to the protocol.
351 			 */
352 			nd6log(LOG_DEBUG,
353 			    "nd6_options: unsupported option %d - "
354 			    "option ignored\n", nd_opt->nd_opt_type);
355 		}
356 
357 skip1:
358 		i++;
359 		if (i > nd6_maxndopt) {
360 			ICMP6_STATINC(ICMP6_STAT_ND_TOOMANYOPT);
361 			nd6log(LOG_INFO, "too many loop in nd opt\n");
362 			break;
363 		}
364 
365 		if (ndopts->nd_opts_done)
366 			break;
367 	}
368 
369 	return 0;
370 }
371 
372 /*
373  * ND6 timer routine to handle ND6 entries
374  */
375 void
376 nd6_llinfo_settimer(struct llentry *ln, time_t xtick)
377 {
378 
379 	CTASSERT(sizeof(time_t) > sizeof(int));
380 	LLE_WLOCK_ASSERT(ln);
381 
382 	if (xtick < 0) {
383 		ln->ln_expire = 0;
384 		ln->ln_ntick = 0;
385 		callout_halt(&ln->ln_timer_ch, &ln->lle_lock);
386 	} else {
387 		ln->ln_expire = time_uptime + xtick / hz;
388 		LLE_ADDREF(ln);
389 		if (xtick > INT_MAX) {
390 			ln->ln_ntick = xtick - INT_MAX;
391 			callout_reset(&ln->ln_timer_ch, INT_MAX,
392 			    nd6_llinfo_timer, ln);
393 		} else {
394 			ln->ln_ntick = 0;
395 			callout_reset(&ln->ln_timer_ch, xtick,
396 			    nd6_llinfo_timer, ln);
397 		}
398 	}
399 }
400 
401 /*
402  * Gets source address of the first packet in hold queue
403  * and stores it in @src.
404  * Returns pointer to @src (if hold queue is not empty) or NULL.
405  */
406 static struct in6_addr *
407 nd6_llinfo_get_holdsrc(struct llentry *ln, struct in6_addr *src)
408 {
409 	struct ip6_hdr *hip6;
410 
411 	if (ln == NULL || ln->ln_hold == NULL)
412 		return NULL;
413 
414 	/*
415 	 * assuming every packet in ln_hold has the same IP header
416 	 */
417 	hip6 = mtod(ln->ln_hold, struct ip6_hdr *);
418 	/* XXX pullup? */
419 	if (sizeof(*hip6) < ln->ln_hold->m_len)
420 		*src = hip6->ip6_src;
421 	else
422 		src = NULL;
423 
424 	return src;
425 }
426 
427 static void
428 nd6_llinfo_timer(void *arg)
429 {
430 	struct llentry *ln = arg;
431 	struct ifnet *ifp;
432 	struct nd_ifinfo *ndi = NULL;
433 	bool send_ns = false;
434 	const struct in6_addr *daddr6 = NULL;
435 
436 	mutex_enter(softnet_lock);
437 	KERNEL_LOCK(1, NULL);
438 
439 	LLE_WLOCK(ln);
440 	if (ln->ln_ntick > 0) {
441 		nd6_llinfo_settimer(ln, ln->ln_ntick);
442 		goto out;
443 	}
444 
445 	if (callout_pending(&ln->la_timer)) {
446 		/*
447 		 * Here we are a bit odd here in the treatment of
448 		 * active/pending. If the pending bit is set, it got
449 		 * rescheduled before I ran. The active
450 		 * bit we ignore, since if it was stopped
451 		 * in ll_tablefree() and was currently running
452 		 * it would have return 0 so the code would
453 		 * not have deleted it since the callout could
454 		 * not be stopped so we want to go through
455 		 * with the delete here now. If the callout
456 		 * was restarted, the pending bit will be back on and
457 		 * we just want to bail since the callout_reset would
458 		 * return 1 and our reference would have been removed
459 		 * by nd6_llinfo_settimer above since canceled
460 		 * would have been 1.
461 		 */
462 		goto out;
463 	}
464 
465 	ifp = ln->lle_tbl->llt_ifp;
466 
467 	KASSERT(ifp != NULL);
468 
469 	ndi = ND_IFINFO(ifp);
470 
471 	switch (ln->ln_state) {
472 	case ND6_LLINFO_INCOMPLETE:
473 		if (ln->ln_asked < nd6_mmaxtries) {
474 			ln->ln_asked++;
475 			send_ns = true;
476 		} else {
477 			struct mbuf *m = ln->ln_hold;
478 			if (m) {
479 				struct mbuf *m0;
480 
481 				/*
482 				 * assuming every packet in ln_hold has
483 				 * the same IP header
484 				 */
485 				m0 = m->m_nextpkt;
486 				m->m_nextpkt = NULL;
487 				ln->ln_hold = m0;
488 				clear_llinfo_pqueue(ln);
489  			}
490 			nd6_free(ln, 0);
491 			ln = NULL;
492 			if (m != NULL)
493 				icmp6_error2(m, ICMP6_DST_UNREACH,
494 				    ICMP6_DST_UNREACH_ADDR, 0, ifp);
495 		}
496 		break;
497 	case ND6_LLINFO_REACHABLE:
498 		if (!ND6_LLINFO_PERMANENT(ln)) {
499 			ln->ln_state = ND6_LLINFO_STALE;
500 			nd6_llinfo_settimer(ln, nd6_gctimer * hz);
501 		}
502 		break;
503 
504 	case ND6_LLINFO_PURGE:
505 	case ND6_LLINFO_STALE:
506 		/* Garbage Collection(RFC 2461 5.3) */
507 		if (!ND6_LLINFO_PERMANENT(ln)) {
508 			nd6_free(ln, 1);
509 			ln = NULL;
510 		}
511 		break;
512 
513 	case ND6_LLINFO_DELAY:
514 		if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) {
515 			/* We need NUD */
516 			ln->ln_asked = 1;
517 			ln->ln_state = ND6_LLINFO_PROBE;
518 			daddr6 = &ln->r_l3addr.addr6;
519 			send_ns = true;
520 		} else {
521 			ln->ln_state = ND6_LLINFO_STALE; /* XXX */
522 			nd6_llinfo_settimer(ln, nd6_gctimer * hz);
523 		}
524 		break;
525 	case ND6_LLINFO_PROBE:
526 		if (ln->ln_asked < nd6_umaxtries) {
527 			ln->ln_asked++;
528 			daddr6 = &ln->r_l3addr.addr6;
529 			send_ns = true;
530 		} else {
531 			nd6_free(ln, 0);
532 			ln = NULL;
533 		}
534 		break;
535 	}
536 
537 	if (send_ns) {
538 		struct in6_addr src, *psrc;
539 		const struct in6_addr *taddr6 = &ln->r_l3addr.addr6;
540 
541 		nd6_llinfo_settimer(ln, ndi->retrans * hz / 1000);
542 		psrc = nd6_llinfo_get_holdsrc(ln, &src);
543 		LLE_FREE_LOCKED(ln);
544 		ln = NULL;
545 		nd6_ns_output(ifp, daddr6, taddr6, psrc, 0);
546 	}
547 
548 out:
549 	if (ln != NULL)
550 		LLE_FREE_LOCKED(ln);
551 	KERNEL_UNLOCK_ONE(NULL);
552 	mutex_exit(softnet_lock);
553 }
554 
555 /*
556  * ND6 timer routine to expire default route list and prefix list
557  */
558 static void
559 nd6_timer(void *ignored_arg)
560 {
561 	struct nd_defrouter *next_dr, *dr;
562 	struct nd_prefix *next_pr, *pr;
563 	struct in6_ifaddr *ia6, *nia6;
564 
565 	callout_reset(&nd6_timer_ch, nd6_prune * hz,
566 	    nd6_timer, NULL);
567 
568 	mutex_enter(softnet_lock);
569 	KERNEL_LOCK(1, NULL);
570 
571 	/* expire default router list */
572 
573 	TAILQ_FOREACH_SAFE(dr, &nd_defrouter, dr_entry, next_dr) {
574 		if (dr->expire && dr->expire < time_uptime) {
575 			defrtrlist_del(dr, NULL);
576 		}
577 	}
578 
579 	/*
580 	 * expire interface addresses.
581 	 * in the past the loop was inside prefix expiry processing.
582 	 * However, from a stricter speci-confrmance standpoint, we should
583 	 * rather separate address lifetimes and prefix lifetimes.
584 	 */
585   addrloop:
586 	for (ia6 = in6_ifaddr; ia6; ia6 = nia6) {
587 		nia6 = ia6->ia_next;
588 		/* check address lifetime */
589 		if (IFA6_IS_INVALID(ia6)) {
590 			int regen = 0;
591 
592 			/*
593 			 * If the expiring address is temporary, try
594 			 * regenerating a new one.  This would be useful when
595 			 * we suspended a laptop PC, then turned it on after a
596 			 * period that could invalidate all temporary
597 			 * addresses.  Although we may have to restart the
598 			 * loop (see below), it must be after purging the
599 			 * address.  Otherwise, we'd see an infinite loop of
600 			 * regeneration.
601 			 */
602 			if (ip6_use_tempaddr &&
603 			    (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
604 				if (regen_tmpaddr(ia6) == 0)
605 					regen = 1;
606 			}
607 
608  			in6_purgeaddr(&ia6->ia_ifa);
609 
610 			if (regen)
611 				goto addrloop; /* XXX: see below */
612 		} else if (IFA6_IS_DEPRECATED(ia6)) {
613 			int oldflags = ia6->ia6_flags;
614 
615 			if ((oldflags & IN6_IFF_DEPRECATED) == 0) {
616 				ia6->ia6_flags |= IN6_IFF_DEPRECATED;
617 				rt_newaddrmsg(RTM_NEWADDR,
618 				    (struct ifaddr *)ia6, 0, NULL);
619 			}
620 
621 			/*
622 			 * If a temporary address has just become deprecated,
623 			 * regenerate a new one if possible.
624 			 */
625 			if (ip6_use_tempaddr &&
626 			    (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
627 			    (oldflags & IN6_IFF_DEPRECATED) == 0) {
628 
629 				if (regen_tmpaddr(ia6) == 0) {
630 					/*
631 					 * A new temporary address is
632 					 * generated.
633 					 * XXX: this means the address chain
634 					 * has changed while we are still in
635 					 * the loop.  Although the change
636 					 * would not cause disaster (because
637 					 * it's not a deletion, but an
638 					 * addition,) we'd rather restart the
639 					 * loop just for safety.  Or does this
640 					 * significantly reduce performance??
641 					 */
642 					goto addrloop;
643 				}
644 			}
645 		} else {
646 			/*
647 			 * A new RA might have made a deprecated address
648 			 * preferred.
649 			 */
650 			if (ia6->ia6_flags & IN6_IFF_DEPRECATED) {
651 				ia6->ia6_flags &= ~IN6_IFF_DEPRECATED;
652 				rt_newaddrmsg(RTM_NEWADDR,
653 				    (struct ifaddr *)ia6, 0, NULL);
654 			}
655 		}
656 	}
657 
658 	/* expire prefix list */
659 	LIST_FOREACH_SAFE(pr, &nd_prefix, ndpr_entry, next_pr) {
660 		/*
661 		 * check prefix lifetime.
662 		 * since pltime is just for autoconf, pltime processing for
663 		 * prefix is not necessary.
664 		 */
665 		if (pr->ndpr_vltime != ND6_INFINITE_LIFETIME &&
666 		    time_uptime - pr->ndpr_lastupdate > pr->ndpr_vltime) {
667 
668 			/*
669 			 * address expiration and prefix expiration are
670 			 * separate.  NEVER perform in6_purgeaddr here.
671 			 */
672 
673 			prelist_remove(pr);
674 		}
675 	}
676 
677 	KERNEL_UNLOCK_ONE(NULL);
678 	mutex_exit(softnet_lock);
679 }
680 
681 /* ia6: deprecated/invalidated temporary address */
682 static int
683 regen_tmpaddr(struct in6_ifaddr *ia6)
684 {
685 	struct ifaddr *ifa;
686 	struct ifnet *ifp;
687 	struct in6_ifaddr *public_ifa6 = NULL;
688 
689 	ifp = ia6->ia_ifa.ifa_ifp;
690 	IFADDR_FOREACH(ifa, ifp) {
691 		struct in6_ifaddr *it6;
692 
693 		if (ifa->ifa_addr->sa_family != AF_INET6)
694 			continue;
695 
696 		it6 = (struct in6_ifaddr *)ifa;
697 
698 		/* ignore no autoconf addresses. */
699 		if ((it6->ia6_flags & IN6_IFF_AUTOCONF) == 0)
700 			continue;
701 
702 		/* ignore autoconf addresses with different prefixes. */
703 		if (it6->ia6_ndpr == NULL || it6->ia6_ndpr != ia6->ia6_ndpr)
704 			continue;
705 
706 		/*
707 		 * Now we are looking at an autoconf address with the same
708 		 * prefix as ours.  If the address is temporary and is still
709 		 * preferred, do not create another one.  It would be rare, but
710 		 * could happen, for example, when we resume a laptop PC after
711 		 * a long period.
712 		 */
713 		if ((it6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
714 		    !IFA6_IS_DEPRECATED(it6)) {
715 			public_ifa6 = NULL;
716 			break;
717 		}
718 
719 		/*
720 		 * This is a public autoconf address that has the same prefix
721 		 * as ours.  If it is preferred, keep it.  We can't break the
722 		 * loop here, because there may be a still-preferred temporary
723 		 * address with the prefix.
724 		 */
725 		if (!IFA6_IS_DEPRECATED(it6))
726 		    public_ifa6 = it6;
727 	}
728 
729 	if (public_ifa6 != NULL) {
730 		int e;
731 
732 		/*
733 		 * Random factor is introduced in the preferred lifetime, so
734 		 * we do not need additional delay (3rd arg to in6_tmpifadd).
735 		 */
736 		if ((e = in6_tmpifadd(public_ifa6, 0, 0)) != 0) {
737 			log(LOG_NOTICE, "regen_tmpaddr: failed to create a new"
738 			    " tmp addr, errno=%d\n", e);
739 			return -1;
740 		}
741 		return 0;
742 	}
743 
744 	return -1;
745 }
746 
747 bool
748 nd6_accepts_rtadv(const struct nd_ifinfo *ndi)
749 {
750 	switch (ndi->flags & (ND6_IFF_ACCEPT_RTADV|ND6_IFF_OVERRIDE_RTADV)) {
751 	case ND6_IFF_OVERRIDE_RTADV|ND6_IFF_ACCEPT_RTADV:
752 		return true;
753 	case ND6_IFF_ACCEPT_RTADV:
754 		return ip6_accept_rtadv != 0;
755 	case ND6_IFF_OVERRIDE_RTADV:
756 	case 0:
757 	default:
758 		return false;
759 	}
760 }
761 
762 /*
763  * Nuke neighbor cache/prefix/default router management table, right before
764  * ifp goes away.
765  */
766 void
767 nd6_purge(struct ifnet *ifp, struct in6_ifextra *ext)
768 {
769 	struct nd_defrouter *dr, *ndr;
770 	struct nd_prefix *pr, *npr;
771 
772 	/*
773 	 * During detach, the ND info might be already removed, but
774 	 * then is explitly passed as argument.
775 	 * Otherwise get it from ifp->if_afdata.
776 	 */
777 	if (ext == NULL)
778 		ext = ifp->if_afdata[AF_INET6];
779 	if (ext == NULL)
780 		return;
781 
782 	/*
783 	 * Nuke default router list entries toward ifp.
784 	 * We defer removal of default router list entries that is installed
785 	 * in the routing table, in order to keep additional side effects as
786 	 * small as possible.
787 	 */
788 	TAILQ_FOREACH_SAFE(dr, &nd_defrouter, dr_entry, ndr) {
789 		if (dr->installed)
790 			continue;
791 
792 		if (dr->ifp == ifp) {
793 			KASSERT(ext != NULL);
794 			defrtrlist_del(dr, ext);
795 		}
796 	}
797 
798 	TAILQ_FOREACH_SAFE(dr, &nd_defrouter, dr_entry, ndr) {
799 		if (!dr->installed)
800 			continue;
801 
802 		if (dr->ifp == ifp) {
803 			KASSERT(ext != NULL);
804 			defrtrlist_del(dr, ext);
805 		}
806 	}
807 
808 	/* Nuke prefix list entries toward ifp */
809 	LIST_FOREACH_SAFE(pr, &nd_prefix, ndpr_entry, npr) {
810 		if (pr->ndpr_ifp == ifp) {
811 			/*
812 			 * Because if_detach() does *not* release prefixes
813 			 * while purging addresses the reference count will
814 			 * still be above zero. We therefore reset it to
815 			 * make sure that the prefix really gets purged.
816 			 */
817 			pr->ndpr_refcnt = 0;
818 			/*
819 			 * Previously, pr->ndpr_addr is removed as well,
820 			 * but I strongly believe we don't have to do it.
821 			 * nd6_purge() is only called from in6_ifdetach(),
822 			 * which removes all the associated interface addresses
823 			 * by itself.
824 			 * (jinmei@kame.net 20010129)
825 			 */
826 			prelist_remove(pr);
827 		}
828 	}
829 
830 	/* cancel default outgoing interface setting */
831 	if (nd6_defifindex == ifp->if_index)
832 		nd6_setdefaultiface(0);
833 
834 	/* XXX: too restrictive? */
835 	if (!ip6_forwarding && ifp->if_afdata[AF_INET6]) {
836 		struct nd_ifinfo *ndi = ND_IFINFO(ifp);
837 		if (ndi && nd6_accepts_rtadv(ndi)) {
838 			/* refresh default router list */
839 			defrouter_select();
840 		}
841 	}
842 
843 	/*
844 	 * We may not need to nuke the neighbor cache entries here
845 	 * because the neighbor cache is kept in if_afdata[AF_INET6].
846 	 * nd6_purge() is invoked by in6_ifdetach() which is called
847 	 * from if_detach() where everything gets purged. However
848 	 * in6_ifdetach is directly called from vlan(4), so we still
849 	 * need to purge entries here.
850 	 */
851 	if (ext->lltable != NULL)
852 		lltable_purge_entries(ext->lltable);
853 }
854 
855 struct llentry *
856 nd6_lookup(const struct in6_addr *addr6, const struct ifnet *ifp, bool wlock)
857 {
858 	struct sockaddr_in6 sin6;
859 	struct llentry *ln;
860 
861 	sockaddr_in6_init(&sin6, addr6, 0, 0, 0);
862 
863 	IF_AFDATA_RLOCK(ifp);
864 	ln = lla_lookup(LLTABLE6(ifp), wlock ? LLE_EXCLUSIVE : 0,
865 	    sin6tosa(&sin6));
866 	IF_AFDATA_RUNLOCK(ifp);
867 
868 	return ln;
869 }
870 
871 struct llentry *
872 nd6_create(const struct in6_addr *addr6, const struct ifnet *ifp)
873 {
874 	struct sockaddr_in6 sin6;
875 	struct llentry *ln;
876 
877 	sockaddr_in6_init(&sin6, addr6, 0, 0, 0);
878 
879 	IF_AFDATA_WLOCK(ifp);
880 	ln = lla_create(LLTABLE6(ifp), LLE_EXCLUSIVE,
881 	    sin6tosa(&sin6));
882 	IF_AFDATA_WUNLOCK(ifp);
883 
884 	if (ln != NULL)
885 		ln->ln_state = ND6_LLINFO_NOSTATE;
886 
887 	return ln;
888 }
889 
890 /*
891  * Test whether a given IPv6 address is a neighbor or not, ignoring
892  * the actual neighbor cache.  The neighbor cache is ignored in order
893  * to not reenter the routing code from within itself.
894  */
895 static int
896 nd6_is_new_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp)
897 {
898 	struct nd_prefix *pr;
899 	struct ifaddr *dstaddr;
900 
901 	/*
902 	 * A link-local address is always a neighbor.
903 	 * XXX: a link does not necessarily specify a single interface.
904 	 */
905 	if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) {
906 		struct sockaddr_in6 sin6_copy;
907 		u_int32_t zone;
908 
909 		/*
910 		 * We need sin6_copy since sa6_recoverscope() may modify the
911 		 * content (XXX).
912 		 */
913 		sin6_copy = *addr;
914 		if (sa6_recoverscope(&sin6_copy))
915 			return 0; /* XXX: should be impossible */
916 		if (in6_setscope(&sin6_copy.sin6_addr, ifp, &zone))
917 			return 0;
918 		if (sin6_copy.sin6_scope_id == zone)
919 			return 1;
920 		else
921 			return 0;
922 	}
923 
924 	/*
925 	 * If the address matches one of our addresses,
926 	 * it should be a neighbor.
927 	 * If the address matches one of our on-link prefixes, it should be a
928 	 * neighbor.
929 	 */
930 	LIST_FOREACH(pr, &nd_prefix, ndpr_entry) {
931 		if (pr->ndpr_ifp != ifp)
932 			continue;
933 
934 		if (!(pr->ndpr_stateflags & NDPRF_ONLINK)) {
935 			struct rtentry *rt;
936 
937 			rt = rtalloc1((struct sockaddr *)&pr->ndpr_prefix, 0);
938 			if (rt == NULL)
939 				continue;
940 			/*
941 			 * This is the case where multiple interfaces
942 			 * have the same prefix, but only one is installed
943 			 * into the routing table and that prefix entry
944 			 * is not the one being examined here. In the case
945 			 * where RADIX_MPATH is enabled, multiple route
946 			 * entries (of the same rt_key value) will be
947 			 * installed because the interface addresses all
948 			 * differ.
949 			 */
950 			if (!IN6_ARE_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
951 			    &satocsin6(rt_getkey(rt))->sin6_addr)) {
952 				continue;
953 			}
954 		}
955 
956 		if (IN6_ARE_MASKED_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
957 		    &addr->sin6_addr, &pr->ndpr_mask))
958 			return 1;
959 	}
960 
961 	/*
962 	 * If the address is assigned on the node of the other side of
963 	 * a p2p interface, the address should be a neighbor.
964 	 */
965 	dstaddr = ifa_ifwithdstaddr((const struct sockaddr *)addr);
966 	if (dstaddr != NULL) {
967 		if (dstaddr->ifa_ifp == ifp) {
968 #ifdef __FreeBSD__
969 			/* XXX we need to ifaref in ifa_ifwithdstaddr as well */
970 			ifafree(dstaddr);
971 #endif
972 			return 1;
973 		}
974 #ifdef __FreeBSD__
975 		/* XXX we need to ifaref in ifa_ifwithdstaddr as well */
976 		ifafree(dstaddr);
977 #endif
978 	}
979 
980 	/*
981 	 * If the default router list is empty, all addresses are regarded
982 	 * as on-link, and thus, as a neighbor.
983 	 */
984 	if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV &&
985 	    TAILQ_EMPTY(&nd_defrouter) &&
986 	    nd6_defifindex == ifp->if_index) {
987 		return 1;
988 	}
989 
990 	return 0;
991 }
992 
993 /*
994  * Detect if a given IPv6 address identifies a neighbor on a given link.
995  * XXX: should take care of the destination of a p2p link?
996  */
997 int
998 nd6_is_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp)
999 {
1000 	struct nd_prefix *pr;
1001 	struct llentry *ln;
1002 	struct rtentry *rt;
1003 
1004 	/*
1005 	 * A link-local address is always a neighbor.
1006 	 * XXX: a link does not necessarily specify a single interface.
1007 	 */
1008 	if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) {
1009 		struct sockaddr_in6 sin6_copy;
1010 		u_int32_t zone;
1011 
1012 		/*
1013 		 * We need sin6_copy since sa6_recoverscope() may modify the
1014 		 * content (XXX).
1015 		 */
1016 		sin6_copy = *addr;
1017 		if (sa6_recoverscope(&sin6_copy))
1018 			return 0; /* XXX: should be impossible */
1019 		if (in6_setscope(&sin6_copy.sin6_addr, ifp, &zone))
1020 			return 0;
1021 		if (sin6_copy.sin6_scope_id == zone)
1022 			return 1;
1023 		else
1024 			return 0;
1025 	}
1026 
1027 	/*
1028 	 * If the address matches one of our on-link prefixes, it should be a
1029 	 * neighbor.
1030 	 */
1031 	LIST_FOREACH(pr, &nd_prefix, ndpr_entry) {
1032 		if (pr->ndpr_ifp != ifp)
1033 			continue;
1034 
1035 		if (!(pr->ndpr_stateflags & NDPRF_ONLINK))
1036 			continue;
1037 
1038 		if (IN6_ARE_MASKED_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
1039 		    &addr->sin6_addr, &pr->ndpr_mask))
1040 			return 1;
1041 	}
1042 
1043 	/*
1044 	 * If the default router list is empty, all addresses are regarded
1045 	 * as on-link, and thus, as a neighbor.
1046 	 * XXX: we restrict the condition to hosts, because routers usually do
1047 	 * not have the "default router list".
1048 	 */
1049 	if (!ip6_forwarding && TAILQ_FIRST(&nd_defrouter) == NULL &&
1050 	    nd6_defifindex == ifp->if_index) {
1051 		return 1;
1052 	}
1053 
1054 	IF_AFDATA_UNLOCK_ASSERT(ifp);
1055 	if (nd6_is_new_addr_neighbor(addr, ifp))
1056 		return 1;
1057 
1058 	/*
1059 	 * Even if the address matches none of our addresses, it might be
1060 	 * in the neighbor cache or a connected route.
1061 	 */
1062 	ln = nd6_lookup(&addr->sin6_addr, ifp, false);
1063 	if (ln != NULL) {
1064 		LLE_RUNLOCK(ln);
1065 		return 1;
1066 	}
1067 
1068 	rt = rtalloc1(sin6tocsa(addr), 0);
1069 	if (rt == NULL)
1070 		return 0;
1071 
1072 	if ((rt->rt_flags & RTF_CONNECTED) && (rt->rt_ifp == ifp
1073 #if NBRIDGE > 0
1074 	    || rt->rt_ifp->if_bridge == ifp->if_bridge
1075 #endif
1076 #if NCARP > 0
1077 	    || (ifp->if_type == IFT_CARP && rt->rt_ifp == ifp->if_carpdev) ||
1078 	    (rt->rt_ifp->if_type == IFT_CARP && rt->rt_ifp->if_carpdev == ifp)||
1079 	    (ifp->if_type == IFT_CARP && rt->rt_ifp->if_type == IFT_CARP &&
1080 	    rt->rt_ifp->if_carpdev == ifp->if_carpdev)
1081 #endif
1082 	    )) {
1083 		rtfree(rt);
1084 		return 1;
1085 	}
1086 	rtfree(rt);
1087 
1088 	return 0;
1089 }
1090 
1091 /*
1092  * Free an nd6 llinfo entry.
1093  * Since the function would cause significant changes in the kernel, DO NOT
1094  * make it global, unless you have a strong reason for the change, and are sure
1095  * that the change is safe.
1096  */
1097 static void
1098 nd6_free(struct llentry *ln, int gc)
1099 {
1100 	struct nd_defrouter *dr;
1101 	struct ifnet *ifp;
1102 	struct in6_addr *in6;
1103 
1104 	KASSERT(ln != NULL);
1105 	LLE_WLOCK_ASSERT(ln);
1106 
1107 	ifp = ln->lle_tbl->llt_ifp;
1108 	in6 = &ln->r_l3addr.addr6;
1109 	/*
1110 	 * we used to have pfctlinput(PRC_HOSTDEAD) here.
1111 	 * even though it is not harmful, it was not really necessary.
1112 	 */
1113 
1114 	/* cancel timer */
1115 	nd6_llinfo_settimer(ln, -1);
1116 
1117 	if (!ip6_forwarding) {
1118 		int s;
1119 		s = splsoftnet();
1120 		dr = defrouter_lookup(in6, ifp);
1121 
1122 		if (dr != NULL && dr->expire &&
1123 		    ln->ln_state == ND6_LLINFO_STALE && gc) {
1124 			/*
1125 			 * If the reason for the deletion is just garbage
1126 			 * collection, and the neighbor is an active default
1127 			 * router, do not delete it.  Instead, reset the GC
1128 			 * timer using the router's lifetime.
1129 			 * Simply deleting the entry would affect default
1130 			 * router selection, which is not necessarily a good
1131 			 * thing, especially when we're using router preference
1132 			 * values.
1133 			 * XXX: the check for ln_state would be redundant,
1134 			 *      but we intentionally keep it just in case.
1135 			 */
1136 			if (dr->expire > time_uptime)
1137 				nd6_llinfo_settimer(ln,
1138 				    (dr->expire - time_uptime) * hz);
1139 			else
1140 				nd6_llinfo_settimer(ln, nd6_gctimer * hz);
1141 			splx(s);
1142 			LLE_WUNLOCK(ln);
1143 			return;
1144 		}
1145 
1146 		if (ln->ln_router || dr) {
1147 			/*
1148 			 * We need to unlock to avoid a LOR with rt6_flush()
1149 			 * with the rnh and for the calls to
1150 			 * pfxlist_onlink_check() and defrouter_select() in the
1151 			 * block further down for calls into nd6_lookup().
1152 			 * We still hold a ref.
1153 			 */
1154 			LLE_WUNLOCK(ln);
1155 
1156 			/*
1157 			 * rt6_flush must be called whether or not the neighbor
1158 			 * is in the Default Router List.
1159 			 * See a corresponding comment in nd6_na_input().
1160 			 */
1161 			rt6_flush(in6, ifp);
1162 		}
1163 
1164 		if (dr) {
1165 			/*
1166 			 * Unreachablity of a router might affect the default
1167 			 * router selection and on-link detection of advertised
1168 			 * prefixes.
1169 			 */
1170 
1171 			/*
1172 			 * Temporarily fake the state to choose a new default
1173 			 * router and to perform on-link determination of
1174 			 * prefixes correctly.
1175 			 * Below the state will be set correctly,
1176 			 * or the entry itself will be deleted.
1177 			 */
1178 			ln->ln_state = ND6_LLINFO_INCOMPLETE;
1179 
1180 			/*
1181 			 * Since defrouter_select() does not affect the
1182 			 * on-link determination and MIP6 needs the check
1183 			 * before the default router selection, we perform
1184 			 * the check now.
1185 			 */
1186 			pfxlist_onlink_check();
1187 
1188 			/*
1189 			 * refresh default router list
1190 			 */
1191 			defrouter_select();
1192 		}
1193 
1194 #ifdef __FreeBSD__
1195 		/*
1196 		 * If this entry was added by an on-link redirect, remove the
1197 		 * corresponding host route.
1198 		 */
1199 		if (ln->la_flags & LLE_REDIRECT)
1200 			nd6_free_redirect(ln);
1201 #endif
1202 
1203 		if (ln->ln_router || dr)
1204 			LLE_WLOCK(ln);
1205 
1206 		splx(s);
1207 	}
1208 
1209 	/*
1210 	 * Save to unlock. We still hold an extra reference and will not
1211 	 * free(9) in llentry_free() if someone else holds one as well.
1212 	 */
1213 	LLE_WUNLOCK(ln);
1214 	IF_AFDATA_LOCK(ifp);
1215 	LLE_WLOCK(ln);
1216 
1217 	/* Guard against race with other llentry_free(). */
1218 	if (ln->la_flags & LLE_LINKED) {
1219 		LLE_REMREF(ln);
1220 		llentry_free(ln);
1221 	} else
1222 		LLE_FREE_LOCKED(ln);
1223 
1224 	IF_AFDATA_UNLOCK(ifp);
1225 }
1226 
1227 /*
1228  * Upper-layer reachability hint for Neighbor Unreachability Detection.
1229  *
1230  * XXX cost-effective methods?
1231  */
1232 void
1233 nd6_nud_hint(struct rtentry *rt)
1234 {
1235 	struct llentry *ln;
1236 	struct ifnet *ifp;
1237 
1238 	if (rt == NULL)
1239 		return;
1240 
1241 	ifp = rt->rt_ifp;
1242 	ln = nd6_lookup(&(satocsin6(rt_getkey(rt)))->sin6_addr, ifp, true);
1243 	if (ln == NULL)
1244 		return;
1245 
1246 	if (ln->ln_state < ND6_LLINFO_REACHABLE)
1247 		goto done;
1248 
1249 	/*
1250 	 * if we get upper-layer reachability confirmation many times,
1251 	 * it is possible we have false information.
1252 	 */
1253 	ln->ln_byhint++;
1254 	if (ln->ln_byhint > nd6_maxnudhint)
1255 		goto done;
1256 
1257 	ln->ln_state = ND6_LLINFO_REACHABLE;
1258 	if (!ND6_LLINFO_PERMANENT(ln))
1259 		nd6_llinfo_settimer(ln, ND_IFINFO(rt->rt_ifp)->reachable * hz);
1260 
1261 done:
1262 	LLE_WUNLOCK(ln);
1263 
1264 	return;
1265 }
1266 
1267 static int
1268 nd6_purge_entry(struct lltable *llt, struct llentry *ln, void *farg)
1269 {
1270 	int *n = farg;
1271 
1272 	if (*n <= 0)
1273 		return 0;
1274 
1275 	if (ND6_LLINFO_PERMANENT(ln))
1276 		return 0;
1277 
1278 	LLE_WLOCK(ln);
1279 	if (ln->ln_state > ND6_LLINFO_INCOMPLETE)
1280 		ln->ln_state = ND6_LLINFO_STALE;
1281 	else
1282 		ln->ln_state = ND6_LLINFO_PURGE;
1283 	nd6_llinfo_settimer(ln, 0);
1284 	LLE_WUNLOCK(ln);
1285 
1286 	(*n)--;
1287 	return 0;
1288 }
1289 
1290 static void
1291 nd6_gc_neighbors(struct lltable *llt)
1292 {
1293 	int max_gc_entries = 10;
1294 
1295 	if (ip6_neighborgcthresh >= 0 &&
1296 	    lltable_get_entry_count(llt) >= ip6_neighborgcthresh) {
1297 		/*
1298 		 * XXX entries that are "less recently used" should be
1299 		 * freed first.
1300 		 */
1301 		lltable_foreach_lle(llt, nd6_purge_entry, &max_gc_entries);
1302 	}
1303 }
1304 
1305 void
1306 nd6_rtrequest(int req, struct rtentry *rt, const struct rt_addrinfo *info)
1307 {
1308 	struct sockaddr *gate = rt->rt_gateway;
1309 	struct ifnet *ifp = rt->rt_ifp;
1310 	uint8_t namelen = strlen(ifp->if_xname), addrlen = ifp->if_addrlen;
1311 	struct ifaddr *ifa;
1312 
1313 	RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt));
1314 
1315 	if (req == RTM_LLINFO_UPD) {
1316 		int rc;
1317 		struct in6_addr *in6;
1318 		struct in6_addr in6_all;
1319 		int anycast;
1320 
1321 		if ((ifa = info->rti_ifa) == NULL)
1322 			return;
1323 
1324 		in6 = &ifatoia6(ifa)->ia_addr.sin6_addr;
1325 		anycast = ifatoia6(ifa)->ia6_flags & IN6_IFF_ANYCAST;
1326 
1327 		in6_all = in6addr_linklocal_allnodes;
1328 		if ((rc = in6_setscope(&in6_all, ifa->ifa_ifp, NULL)) != 0) {
1329 			log(LOG_ERR, "%s: failed to set scope %s "
1330 			    "(errno=%d)\n", __func__, if_name(ifp), rc);
1331 			return;
1332 		}
1333 
1334 		/* XXX don't set Override for proxy addresses */
1335 		nd6_na_output(ifa->ifa_ifp, &in6_all, in6,
1336 		    (anycast ? 0 : ND_NA_FLAG_OVERRIDE)
1337 #if 0
1338 		    | (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0)
1339 #endif
1340 		    , 1, NULL);
1341 		return;
1342 	}
1343 
1344 	if ((rt->rt_flags & RTF_GATEWAY) != 0)
1345 		return;
1346 
1347 	if (nd6_need_cache(ifp) == 0 && (rt->rt_flags & RTF_HOST) == 0) {
1348 		RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt));
1349 		/*
1350 		 * This is probably an interface direct route for a link
1351 		 * which does not need neighbor caches (e.g. fe80::%lo0/64).
1352 		 * We do not need special treatment below for such a route.
1353 		 * Moreover, the RTF_LLINFO flag which would be set below
1354 		 * would annoy the ndp(8) command.
1355 		 */
1356 		return;
1357 	}
1358 
1359 	switch (req) {
1360 	case RTM_ADD:
1361 		RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt));
1362 		/*
1363 		 * There is no backward compatibility :)
1364 		 *
1365 		 * if ((rt->rt_flags & RTF_HOST) == 0 &&
1366 		 *     SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff)
1367 		 *	   rt->rt_flags |= RTF_CLONING;
1368 		 */
1369 		/* XXX should move to route.c? */
1370 		if (rt->rt_flags & (RTF_CONNECTED | RTF_LOCAL)) {
1371 			union {
1372 				struct sockaddr sa;
1373 				struct sockaddr_dl sdl;
1374 				struct sockaddr_storage ss;
1375 			} u;
1376 			/*
1377 			 * Case 1: This route should come from a route to
1378 			 * interface (RTF_CLONING case) or the route should be
1379 			 * treated as on-link but is currently not
1380 			 * (RTF_LLINFO && ln == NULL case).
1381 			 */
1382 			if (sockaddr_dl_init(&u.sdl, sizeof(u.ss),
1383 			    ifp->if_index, ifp->if_type,
1384 			    NULL, namelen, NULL, addrlen) == NULL) {
1385 				printf("%s.%d: sockaddr_dl_init(, %zu, ) "
1386 				    "failed on %s\n", __func__, __LINE__,
1387 				    sizeof(u.ss), if_name(ifp));
1388 			}
1389 			rt_setgate(rt, &u.sa);
1390 			gate = rt->rt_gateway;
1391 			RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt));
1392 			if (gate == NULL) {
1393 				log(LOG_ERR,
1394 				    "%s: rt_setgate failed on %s\n", __func__,
1395 				    if_name(ifp));
1396 				break;
1397 			}
1398 
1399 			RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt));
1400 			if ((rt->rt_flags & RTF_CONNECTED) != 0)
1401 				break;
1402 		}
1403 		RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt));
1404 		/*
1405 		 * In IPv4 code, we try to annonuce new RTF_ANNOUNCE entry here.
1406 		 * We don't do that here since llinfo is not ready yet.
1407 		 *
1408 		 * There are also couple of other things to be discussed:
1409 		 * - unsolicited NA code needs improvement beforehand
1410 		 * - RFC2461 says we MAY send multicast unsolicited NA
1411 		 *   (7.2.6 paragraph 4), however, it also says that we
1412 		 *   SHOULD provide a mechanism to prevent multicast NA storm.
1413 		 *   we don't have anything like it right now.
1414 		 *   note that the mechanism needs a mutual agreement
1415 		 *   between proxies, which means that we need to implement
1416 		 *   a new protocol, or a new kludge.
1417 		 * - from RFC2461 6.2.4, host MUST NOT send an unsolicited NA.
1418 		 *   we need to check ip6forwarding before sending it.
1419 		 *   (or should we allow proxy ND configuration only for
1420 		 *   routers?  there's no mention about proxy ND from hosts)
1421 		 */
1422 #if 0
1423 		/* XXX it does not work */
1424 		if (rt->rt_flags & RTF_ANNOUNCE)
1425 			nd6_na_output(ifp,
1426 			      &satocsin6(rt_getkey(rt))->sin6_addr,
1427 			      &satocsin6(rt_getkey(rt))->sin6_addr,
1428 			      ip6_forwarding ? ND_NA_FLAG_ROUTER : 0,
1429 			      1, NULL);
1430 #endif
1431 
1432 		if ((ifp->if_flags & (IFF_POINTOPOINT | IFF_LOOPBACK)) == 0) {
1433 			RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt));
1434 			/*
1435 			 * Address resolution isn't necessary for a point to
1436 			 * point link, so we can skip this test for a p2p link.
1437 			 */
1438 			if (gate->sa_family != AF_LINK ||
1439 			    gate->sa_len <
1440 			    sockaddr_dl_measure(namelen, addrlen)) {
1441 				log(LOG_DEBUG,
1442 				    "nd6_rtrequest: bad gateway value: %s\n",
1443 				    if_name(ifp));
1444 				break;
1445 			}
1446 			satosdl(gate)->sdl_type = ifp->if_type;
1447 			satosdl(gate)->sdl_index = ifp->if_index;
1448 			RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt));
1449 		}
1450 		RT_DPRINTF("rt_getkey(rt) = %p\n", rt_getkey(rt));
1451 
1452 		/*
1453 		 * check if rt_getkey(rt) is an address assigned
1454 		 * to the interface.
1455 		 */
1456 		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp,
1457 		    &satocsin6(rt_getkey(rt))->sin6_addr);
1458 		if (ifa != NULL) {
1459 			if (nd6_useloopback) {
1460 				rt->rt_ifp = lo0ifp;	/* XXX */
1461 				/*
1462 				 * Make sure rt_ifa be equal to the ifaddr
1463 				 * corresponding to the address.
1464 				 * We need this because when we refer
1465 				 * rt_ifa->ia6_flags in ip6_input, we assume
1466 				 * that the rt_ifa points to the address instead
1467 				 * of the loopback address.
1468 				 */
1469 				if (ifa != rt->rt_ifa)
1470 					rt_replace_ifa(rt, ifa);
1471 			}
1472 		} else if (rt->rt_flags & RTF_ANNOUNCE) {
1473 			/* join solicited node multicast for proxy ND */
1474 			if (ifp->if_flags & IFF_MULTICAST) {
1475 				struct in6_addr llsol;
1476 				int error;
1477 
1478 				llsol = satocsin6(rt_getkey(rt))->sin6_addr;
1479 				llsol.s6_addr32[0] = htonl(0xff020000);
1480 				llsol.s6_addr32[1] = 0;
1481 				llsol.s6_addr32[2] = htonl(1);
1482 				llsol.s6_addr8[12] = 0xff;
1483 				if (in6_setscope(&llsol, ifp, NULL))
1484 					goto out;
1485 				if (!in6_addmulti(&llsol, ifp, &error, 0)) {
1486 					nd6log(LOG_ERR, "%s: failed to join "
1487 					    "%s (errno=%d)\n", if_name(ifp),
1488 					    ip6_sprintf(&llsol), error);
1489 				}
1490 			}
1491 		}
1492 
1493 	out:
1494 		/*
1495 		 * If we have too many cache entries, initiate immediate
1496 		 * purging for some entries.
1497 		 */
1498 		if (rt->rt_ifp != NULL)
1499 			nd6_gc_neighbors(LLTABLE6(rt->rt_ifp));
1500 		break;
1501 
1502 	case RTM_DELETE:
1503 		/* leave from solicited node multicast for proxy ND */
1504 		if ((rt->rt_flags & RTF_ANNOUNCE) != 0 &&
1505 		    (ifp->if_flags & IFF_MULTICAST) != 0) {
1506 			struct in6_addr llsol;
1507 			struct in6_multi *in6m;
1508 
1509 			llsol = satocsin6(rt_getkey(rt))->sin6_addr;
1510 			llsol.s6_addr32[0] = htonl(0xff020000);
1511 			llsol.s6_addr32[1] = 0;
1512 			llsol.s6_addr32[2] = htonl(1);
1513 			llsol.s6_addr8[12] = 0xff;
1514 			if (in6_setscope(&llsol, ifp, NULL) == 0) {
1515 				IN6_LOOKUP_MULTI(llsol, ifp, in6m);
1516 				if (in6m)
1517 					in6_delmulti(in6m);
1518 			}
1519 		}
1520 		break;
1521 	}
1522 }
1523 
1524 int
1525 nd6_ioctl(u_long cmd, void *data, struct ifnet *ifp)
1526 {
1527 	struct in6_drlist *drl = (struct in6_drlist *)data;
1528 	struct in6_oprlist *oprl = (struct in6_oprlist *)data;
1529 	struct in6_ndireq *ndi = (struct in6_ndireq *)data;
1530 	struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data;
1531 	struct in6_ndifreq *ndif = (struct in6_ndifreq *)data;
1532 	struct nd_defrouter *dr;
1533 	struct nd_prefix *pr;
1534 	int i = 0, error = 0;
1535 	int s;
1536 
1537 	switch (cmd) {
1538 	case SIOCGDRLST_IN6:
1539 		/*
1540 		 * obsolete API, use sysctl under net.inet6.icmp6
1541 		 */
1542 		memset(drl, 0, sizeof(*drl));
1543 		s = splsoftnet();
1544 		TAILQ_FOREACH(dr, &nd_defrouter, dr_entry) {
1545 			if (i >= DRLSTSIZ)
1546 				break;
1547 			drl->defrouter[i].rtaddr = dr->rtaddr;
1548 			in6_clearscope(&drl->defrouter[i].rtaddr);
1549 
1550 			drl->defrouter[i].flags = dr->flags;
1551 			drl->defrouter[i].rtlifetime = dr->rtlifetime;
1552 			drl->defrouter[i].expire = dr->expire ?
1553 			    time_mono_to_wall(dr->expire) : 0;
1554 			drl->defrouter[i].if_index = dr->ifp->if_index;
1555 			i++;
1556 		}
1557 		splx(s);
1558 		break;
1559 	case SIOCGPRLST_IN6:
1560 		/*
1561 		 * obsolete API, use sysctl under net.inet6.icmp6
1562 		 *
1563 		 * XXX the structure in6_prlist was changed in backward-
1564 		 * incompatible manner.  in6_oprlist is used for SIOCGPRLST_IN6,
1565 		 * in6_prlist is used for nd6_sysctl() - fill_prlist().
1566 		 */
1567 		/*
1568 		 * XXX meaning of fields, especialy "raflags", is very
1569 		 * differnet between RA prefix list and RR/static prefix list.
1570 		 * how about separating ioctls into two?
1571 		 */
1572 		memset(oprl, 0, sizeof(*oprl));
1573 		s = splsoftnet();
1574 		LIST_FOREACH(pr, &nd_prefix, ndpr_entry) {
1575 			struct nd_pfxrouter *pfr;
1576 			int j;
1577 
1578 			if (i >= PRLSTSIZ)
1579 				break;
1580 			oprl->prefix[i].prefix = pr->ndpr_prefix.sin6_addr;
1581 			oprl->prefix[i].raflags = pr->ndpr_raf;
1582 			oprl->prefix[i].prefixlen = pr->ndpr_plen;
1583 			oprl->prefix[i].vltime = pr->ndpr_vltime;
1584 			oprl->prefix[i].pltime = pr->ndpr_pltime;
1585 			oprl->prefix[i].if_index = pr->ndpr_ifp->if_index;
1586 			if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME)
1587 				oprl->prefix[i].expire = 0;
1588 			else {
1589 				time_t maxexpire;
1590 
1591 				/* XXX: we assume time_t is signed. */
1592 				maxexpire = (-1) &
1593 				    ~((time_t)1 <<
1594 				    ((sizeof(maxexpire) * 8) - 1));
1595 				if (pr->ndpr_vltime <
1596 				    maxexpire - pr->ndpr_lastupdate) {
1597 					time_t expire;
1598 					expire = pr->ndpr_lastupdate +
1599 					    pr->ndpr_vltime;
1600 					oprl->prefix[i].expire = expire ?
1601 					    time_mono_to_wall(expire) : 0;
1602 				} else
1603 					oprl->prefix[i].expire = maxexpire;
1604 			}
1605 
1606 			j = 0;
1607 			LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) {
1608 				if (j < DRLSTSIZ) {
1609 #define RTRADDR oprl->prefix[i].advrtr[j]
1610 					RTRADDR = pfr->router->rtaddr;
1611 					in6_clearscope(&RTRADDR);
1612 #undef RTRADDR
1613 				}
1614 				j++;
1615 			}
1616 			oprl->prefix[i].advrtrs = j;
1617 			oprl->prefix[i].origin = PR_ORIG_RA;
1618 
1619 			i++;
1620 		}
1621 		splx(s);
1622 
1623 		break;
1624 	case OSIOCGIFINFO_IN6:
1625 #define ND	ndi->ndi
1626 		/* XXX: old ndp(8) assumes a positive value for linkmtu. */
1627 		memset(&ND, 0, sizeof(ND));
1628 		ND.linkmtu = IN6_LINKMTU(ifp);
1629 		ND.maxmtu = ND_IFINFO(ifp)->maxmtu;
1630 		ND.basereachable = ND_IFINFO(ifp)->basereachable;
1631 		ND.reachable = ND_IFINFO(ifp)->reachable;
1632 		ND.retrans = ND_IFINFO(ifp)->retrans;
1633 		ND.flags = ND_IFINFO(ifp)->flags;
1634 		ND.recalctm = ND_IFINFO(ifp)->recalctm;
1635 		ND.chlim = ND_IFINFO(ifp)->chlim;
1636 		break;
1637 	case SIOCGIFINFO_IN6:
1638 		ND = *ND_IFINFO(ifp);
1639 		break;
1640 	case SIOCSIFINFO_IN6:
1641 		/*
1642 		 * used to change host variables from userland.
1643 		 * intented for a use on router to reflect RA configurations.
1644 		 */
1645 		/* 0 means 'unspecified' */
1646 		if (ND.linkmtu != 0) {
1647 			if (ND.linkmtu < IPV6_MMTU ||
1648 			    ND.linkmtu > IN6_LINKMTU(ifp)) {
1649 				error = EINVAL;
1650 				break;
1651 			}
1652 			ND_IFINFO(ifp)->linkmtu = ND.linkmtu;
1653 		}
1654 
1655 		if (ND.basereachable != 0) {
1656 			int obasereachable = ND_IFINFO(ifp)->basereachable;
1657 
1658 			ND_IFINFO(ifp)->basereachable = ND.basereachable;
1659 			if (ND.basereachable != obasereachable)
1660 				ND_IFINFO(ifp)->reachable =
1661 				    ND_COMPUTE_RTIME(ND.basereachable);
1662 		}
1663 		if (ND.retrans != 0)
1664 			ND_IFINFO(ifp)->retrans = ND.retrans;
1665 		if (ND.chlim != 0)
1666 			ND_IFINFO(ifp)->chlim = ND.chlim;
1667 		/* FALLTHROUGH */
1668 	case SIOCSIFINFO_FLAGS:
1669 	{
1670 		struct ifaddr *ifa;
1671 		struct in6_ifaddr *ia;
1672 
1673 		if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
1674 		    !(ND.flags & ND6_IFF_IFDISABLED))
1675 		{
1676 			/*
1677 			 * If the interface is marked as ND6_IFF_IFDISABLED and
1678 			 * has a link-local address with IN6_IFF_DUPLICATED,
1679 			 * do not clear ND6_IFF_IFDISABLED.
1680 			 * See RFC 4862, section 5.4.5.
1681 			 */
1682 			int duplicated_linklocal = 0;
1683 
1684 			IFADDR_FOREACH(ifa, ifp) {
1685 				if (ifa->ifa_addr->sa_family != AF_INET6)
1686 					continue;
1687 				ia = (struct in6_ifaddr *)ifa;
1688 				if ((ia->ia6_flags & IN6_IFF_DUPLICATED) &&
1689 				    IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia)))
1690 				{
1691 					duplicated_linklocal = 1;
1692 					break;
1693 				}
1694 			}
1695 
1696 			if (duplicated_linklocal) {
1697 				ND.flags |= ND6_IFF_IFDISABLED;
1698 				log(LOG_ERR, "Cannot enable an interface"
1699 				    " with a link-local address marked"
1700 				    " duplicate.\n");
1701 			} else {
1702 				ND_IFINFO(ifp)->flags &= ~ND6_IFF_IFDISABLED;
1703 				if (ifp->if_flags & IFF_UP)
1704 					in6_if_up(ifp);
1705 			}
1706 		} else if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
1707 		    (ND.flags & ND6_IFF_IFDISABLED))
1708 		{
1709 			/* Mark all IPv6 addresses as tentative. */
1710 
1711 			ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
1712 			IFADDR_FOREACH(ifa, ifp) {
1713 				if (ifa->ifa_addr->sa_family != AF_INET6)
1714 					continue;
1715 				nd6_dad_stop(ifa);
1716 				ia = (struct in6_ifaddr *)ifa;
1717 				ia->ia6_flags |= IN6_IFF_TENTATIVE;
1718 			}
1719 		}
1720 
1721 		if (ND.flags & ND6_IFF_AUTO_LINKLOCAL) {
1722 			if (!(ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL)) {
1723 				/* auto_linklocal 0->1 transition */
1724 
1725 				ND_IFINFO(ifp)->flags |= ND6_IFF_AUTO_LINKLOCAL;
1726 				in6_ifattach(ifp, NULL);
1727 			} else if (!(ND.flags & ND6_IFF_IFDISABLED) &&
1728 			    ifp->if_flags & IFF_UP)
1729 			{
1730 				/*
1731 				 * When the IF already has
1732 				 * ND6_IFF_AUTO_LINKLOCAL, no link-local
1733 				 * address is assigned, and IFF_UP, try to
1734 				 * assign one.
1735 				 */
1736 				 int haslinklocal = 0;
1737 
1738 				 IFADDR_FOREACH(ifa, ifp) {
1739 					if (ifa->ifa_addr->sa_family !=AF_INET6)
1740 						continue;
1741 					ia = (struct in6_ifaddr *)ifa;
1742 					if (IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia))){
1743 						haslinklocal = 1;
1744 						break;
1745 					}
1746 				 }
1747 				 if (!haslinklocal)
1748 					in6_ifattach(ifp, NULL);
1749 			}
1750 		}
1751 	}
1752 		ND_IFINFO(ifp)->flags = ND.flags;
1753 		break;
1754 #undef ND
1755 	case SIOCSNDFLUSH_IN6:	/* XXX: the ioctl name is confusing... */
1756 		/* sync kernel routing table with the default router list */
1757 		defrouter_reset();
1758 		defrouter_select();
1759 		break;
1760 	case SIOCSPFXFLUSH_IN6:
1761 	{
1762 		/* flush all the prefix advertised by routers */
1763 		struct nd_prefix *pfx, *next;
1764 
1765 		s = splsoftnet();
1766 		LIST_FOREACH_SAFE(pfx, &nd_prefix, ndpr_entry, next) {
1767 			struct in6_ifaddr *ia, *ia_next;
1768 
1769 			if (IN6_IS_ADDR_LINKLOCAL(&pfx->ndpr_prefix.sin6_addr))
1770 				continue; /* XXX */
1771 
1772 			/* do we really have to remove addresses as well? */
1773 			for (ia = in6_ifaddr; ia; ia = ia_next) {
1774 				/* ia might be removed.  keep the next ptr. */
1775 				ia_next = ia->ia_next;
1776 
1777 				if ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1778 					continue;
1779 
1780 				if (ia->ia6_ndpr == pfx)
1781 					in6_purgeaddr(&ia->ia_ifa);
1782 			}
1783 			prelist_remove(pfx);
1784 		}
1785 		splx(s);
1786 		break;
1787 	}
1788 	case SIOCSRTRFLUSH_IN6:
1789 	{
1790 		/* flush all the default routers */
1791 		struct nd_defrouter *drtr, *next;
1792 
1793 		s = splsoftnet();
1794 		defrouter_reset();
1795 		TAILQ_FOREACH_SAFE(drtr, &nd_defrouter, dr_entry, next) {
1796 			defrtrlist_del(drtr, NULL);
1797 		}
1798 		defrouter_select();
1799 		splx(s);
1800 		break;
1801 	}
1802 	case SIOCGNBRINFO_IN6:
1803 	{
1804 		struct llentry *ln;
1805 		struct in6_addr nb_addr = nbi->addr; /* make local for safety */
1806 
1807 		if ((error = in6_setscope(&nb_addr, ifp, NULL)) != 0)
1808 			return error;
1809 
1810 		ln = nd6_lookup(&nb_addr, ifp, false);
1811 		if (ln == NULL) {
1812 			error = EINVAL;
1813 			break;
1814 		}
1815 		nbi->state = ln->ln_state;
1816 		nbi->asked = ln->ln_asked;
1817 		nbi->isrouter = ln->ln_router;
1818 		nbi->expire = ln->ln_expire ?
1819 		    time_mono_to_wall(ln->ln_expire) : 0;
1820 		LLE_RUNLOCK(ln);
1821 
1822 		break;
1823 	}
1824 	case SIOCGDEFIFACE_IN6:	/* XXX: should be implemented as a sysctl? */
1825 		ndif->ifindex = nd6_defifindex;
1826 		break;
1827 	case SIOCSDEFIFACE_IN6:	/* XXX: should be implemented as a sysctl? */
1828 		return nd6_setdefaultiface(ndif->ifindex);
1829 	}
1830 	return error;
1831 }
1832 
1833 void
1834 nd6_llinfo_release_pkts(struct llentry *ln, struct ifnet *ifp)
1835 {
1836 	struct mbuf *m_hold, *m_hold_next;
1837 	struct sockaddr_in6 sin6;
1838 
1839 	LLE_WLOCK_ASSERT(ln);
1840 
1841 	sockaddr_in6_init(&sin6, &ln->r_l3addr.addr6, 0, 0, 0);
1842 
1843 	m_hold = ln->la_hold, ln->la_hold = NULL, ln->la_numheld = 0;
1844 
1845 	LLE_WUNLOCK(ln);
1846 	for (; m_hold != NULL; m_hold = m_hold_next) {
1847 		m_hold_next = m_hold->m_nextpkt;
1848 		m_hold->m_nextpkt = NULL;
1849 
1850 		/*
1851 		 * we assume ifp is not a p2p here, so
1852 		 * just set the 2nd argument as the
1853 		 * 1st one.
1854 		 */
1855 		nd6_output(ifp, ifp, m_hold, &sin6, NULL);
1856 	}
1857 	LLE_WLOCK(ln);
1858 }
1859 
1860 /*
1861  * Create neighbor cache entry and cache link-layer address,
1862  * on reception of inbound ND6 packets.  (RS/RA/NS/redirect)
1863  */
1864 void
1865 nd6_cache_lladdr(
1866     struct ifnet *ifp,
1867     struct in6_addr *from,
1868     char *lladdr,
1869     int lladdrlen,
1870     int type,	/* ICMP6 type */
1871     int code	/* type dependent information */
1872 )
1873 {
1874 	struct nd_ifinfo *ndi = ND_IFINFO(ifp);
1875 	struct llentry *ln = NULL;
1876 	int is_newentry;
1877 	int do_update;
1878 	int olladdr;
1879 	int llchange;
1880 	int newstate = 0;
1881 	uint16_t router = 0;
1882 
1883 	KASSERT(ifp != NULL);
1884 	KASSERT(from != NULL);
1885 
1886 	/* nothing must be updated for unspecified address */
1887 	if (IN6_IS_ADDR_UNSPECIFIED(from))
1888 		return;
1889 
1890 	/*
1891 	 * Validation about ifp->if_addrlen and lladdrlen must be done in
1892 	 * the caller.
1893 	 *
1894 	 * XXX If the link does not have link-layer adderss, what should
1895 	 * we do? (ifp->if_addrlen == 0)
1896 	 * Spec says nothing in sections for RA, RS and NA.  There's small
1897 	 * description on it in NS section (RFC 2461 7.2.3).
1898 	 */
1899 
1900 	ln = nd6_lookup(from, ifp, true);
1901 	if (ln == NULL) {
1902 #if 0
1903 		/* nothing must be done if there's no lladdr */
1904 		if (!lladdr || !lladdrlen)
1905 			return NULL;
1906 #endif
1907 
1908 		ln = nd6_create(from, ifp);
1909 		is_newentry = 1;
1910 	} else {
1911 		/* do nothing if static ndp is set */
1912 		if (ln->la_flags & LLE_STATIC) {
1913 			LLE_WUNLOCK(ln);
1914 			return;
1915 		}
1916 		is_newentry = 0;
1917 	}
1918 
1919 	if (ln == NULL)
1920 		return;
1921 
1922 	olladdr = (ln->la_flags & LLE_VALID) ? 1 : 0;
1923 	if (olladdr && lladdr) {
1924 		llchange = memcmp(lladdr, &ln->ll_addr, ifp->if_addrlen);
1925 	} else
1926 		llchange = 0;
1927 
1928 	/*
1929 	 * newentry olladdr  lladdr  llchange	(*=record)
1930 	 *	0	n	n	--	(1)
1931 	 *	0	y	n	--	(2)
1932 	 *	0	n	y	--	(3) * STALE
1933 	 *	0	y	y	n	(4) *
1934 	 *	0	y	y	y	(5) * STALE
1935 	 *	1	--	n	--	(6)   NOSTATE(= PASSIVE)
1936 	 *	1	--	y	--	(7) * STALE
1937 	 */
1938 
1939 	if (lladdr) {		/* (3-5) and (7) */
1940 		/*
1941 		 * Record source link-layer address
1942 		 * XXX is it dependent to ifp->if_type?
1943 		 */
1944 		memcpy(&ln->ll_addr, lladdr, ifp->if_addrlen);
1945 		ln->la_flags |= LLE_VALID;
1946 	}
1947 
1948 	if (!is_newentry) {
1949 		if ((!olladdr && lladdr) ||		/* (3) */
1950 		    (olladdr && lladdr && llchange)) {	/* (5) */
1951 			do_update = 1;
1952 			newstate = ND6_LLINFO_STALE;
1953 		} else					/* (1-2,4) */
1954 			do_update = 0;
1955 	} else {
1956 		do_update = 1;
1957 		if (lladdr == NULL)			/* (6) */
1958 			newstate = ND6_LLINFO_NOSTATE;
1959 		else					/* (7) */
1960 			newstate = ND6_LLINFO_STALE;
1961 	}
1962 
1963 	if (do_update) {
1964 		/*
1965 		 * Update the state of the neighbor cache.
1966 		 */
1967 		ln->ln_state = newstate;
1968 
1969 		if (ln->ln_state == ND6_LLINFO_STALE) {
1970 			/*
1971 			 * XXX: since nd6_output() below will cause
1972 			 * state tansition to DELAY and reset the timer,
1973 			 * we must set the timer now, although it is actually
1974 			 * meaningless.
1975 			 */
1976 			nd6_llinfo_settimer(ln, nd6_gctimer * hz);
1977 
1978 			nd6_llinfo_release_pkts(ln, ifp);
1979 		} else if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
1980 			/* probe right away */
1981 			nd6_llinfo_settimer((void *)ln, 0);
1982 		}
1983 	}
1984 
1985 	/*
1986 	 * ICMP6 type dependent behavior.
1987 	 *
1988 	 * NS: clear IsRouter if new entry
1989 	 * RS: clear IsRouter
1990 	 * RA: set IsRouter if there's lladdr
1991 	 * redir: clear IsRouter if new entry
1992 	 *
1993 	 * RA case, (1):
1994 	 * The spec says that we must set IsRouter in the following cases:
1995 	 * - If lladdr exist, set IsRouter.  This means (1-5).
1996 	 * - If it is old entry (!newentry), set IsRouter.  This means (7).
1997 	 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
1998 	 * A quetion arises for (1) case.  (1) case has no lladdr in the
1999 	 * neighbor cache, this is similar to (6).
2000 	 * This case is rare but we figured that we MUST NOT set IsRouter.
2001 	 *
2002 	 * newentry olladdr  lladdr  llchange	    NS  RS  RA	redir
2003 	 *							D R
2004 	 *	0	n	n	--	(1)	c   ?     s
2005 	 *	0	y	n	--	(2)	c   s     s
2006 	 *	0	n	y	--	(3)	c   s     s
2007 	 *	0	y	y	n	(4)	c   s     s
2008 	 *	0	y	y	y	(5)	c   s     s
2009 	 *	1	--	n	--	(6) c	c 	c s
2010 	 *	1	--	y	--	(7) c	c   s	c s
2011 	 *
2012 	 *					(c=clear s=set)
2013 	 */
2014 	switch (type & 0xff) {
2015 	case ND_NEIGHBOR_SOLICIT:
2016 		/*
2017 		 * New entry must have is_router flag cleared.
2018 		 */
2019 		if (is_newentry)	/* (6-7) */
2020 			ln->ln_router = 0;
2021 		break;
2022 	case ND_REDIRECT:
2023 		/*
2024 		 * If the icmp is a redirect to a better router, always set the
2025 		 * is_router flag.  Otherwise, if the entry is newly created,
2026 		 * clear the flag.  [RFC 2461, sec 8.3]
2027 		 */
2028 		if (code == ND_REDIRECT_ROUTER)
2029 			ln->ln_router = 1;
2030 		else if (is_newentry) /* (6-7) */
2031 			ln->ln_router = 0;
2032 		break;
2033 	case ND_ROUTER_SOLICIT:
2034 		/*
2035 		 * is_router flag must always be cleared.
2036 		 */
2037 		ln->ln_router = 0;
2038 		break;
2039 	case ND_ROUTER_ADVERT:
2040 		/*
2041 		 * Mark an entry with lladdr as a router.
2042 		 */
2043 		if ((!is_newentry && (olladdr || lladdr)) ||	/* (2-5) */
2044 		    (is_newentry && lladdr)) {			/* (7) */
2045 			ln->ln_router = 1;
2046 		}
2047 		break;
2048 	}
2049 
2050 #if 0
2051 	/* XXX should we send rtmsg as it used to be? */
2052 	if (do_update)
2053 		rt_newmsg(RTM_CHANGE, rt);  /* tell user process */
2054 #endif
2055 
2056 	if (ln != NULL) {
2057 		router = ln->ln_router;
2058 		LLE_WUNLOCK(ln);
2059 	}
2060 
2061 	/*
2062 	 * If we have too many cache entries, initiate immediate
2063 	 * purging for some entries.
2064 	 */
2065 	if (is_newentry)
2066 		nd6_gc_neighbors(LLTABLE6(ifp));
2067 
2068 	/*
2069 	 * When the link-layer address of a router changes, select the
2070 	 * best router again.  In particular, when the neighbor entry is newly
2071 	 * created, it might affect the selection policy.
2072 	 * Question: can we restrict the first condition to the "is_newentry"
2073 	 * case?
2074 	 * XXX: when we hear an RA from a new router with the link-layer
2075 	 * address option, defrouter_select() is called twice, since
2076 	 * defrtrlist_update called the function as well.  However, I believe
2077 	 * we can compromise the overhead, since it only happens the first
2078 	 * time.
2079 	 * XXX: although defrouter_select() should not have a bad effect
2080 	 * for those are not autoconfigured hosts, we explicitly avoid such
2081 	 * cases for safety.
2082 	 */
2083 	if (do_update && router && !ip6_forwarding &&
2084 	    nd6_accepts_rtadv(ndi))
2085 		defrouter_select();
2086 }
2087 
2088 static void
2089 nd6_slowtimo(void *ignored_arg)
2090 {
2091 	struct nd_ifinfo *nd6if;
2092 	struct ifnet *ifp;
2093 	int s;
2094 
2095 	mutex_enter(softnet_lock);
2096 	KERNEL_LOCK(1, NULL);
2097 	callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
2098 	    nd6_slowtimo, NULL);
2099 
2100 	s = pserialize_read_enter();
2101 	IFNET_READER_FOREACH(ifp) {
2102 		nd6if = ND_IFINFO(ifp);
2103 		if (nd6if->basereachable && /* already initialized */
2104 		    (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
2105 			/*
2106 			 * Since reachable time rarely changes by router
2107 			 * advertisements, we SHOULD insure that a new random
2108 			 * value gets recomputed at least once every few hours.
2109 			 * (RFC 2461, 6.3.4)
2110 			 */
2111 			nd6if->recalctm = nd6_recalc_reachtm_interval;
2112 			nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable);
2113 		}
2114 	}
2115 	pserialize_read_exit(s);
2116 
2117 	KERNEL_UNLOCK_ONE(NULL);
2118 	mutex_exit(softnet_lock);
2119 }
2120 
2121 int
2122 nd6_output(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
2123     const struct sockaddr_in6 *dst, struct rtentry *rt)
2124 {
2125 #define senderr(e) { error = (e); goto bad;}
2126 	struct llentry *ln = NULL;
2127 	int error = 0;
2128 	bool created = false;
2129 
2130 	if (rt != NULL) {
2131 		error = rt_check_reject_route(rt, ifp);
2132 		if (error != 0) {
2133 			m_freem(m);
2134 			return error;
2135 		}
2136 	}
2137 
2138 	if (IN6_IS_ADDR_MULTICAST(&dst->sin6_addr))
2139 		goto sendpkt;
2140 
2141 	if (nd6_need_cache(ifp) == 0)
2142 		goto sendpkt;
2143 
2144 	if (rt != NULL && (rt->rt_flags & RTF_GATEWAY) != 0) {
2145 		struct sockaddr_in6 *gw6 = satosin6(rt->rt_gateway);
2146 
2147 		/* XXX remain the check to keep the original behavior. */
2148 		/*
2149 		 * We skip link-layer address resolution and NUD
2150 		 * if the gateway is not a neighbor from ND point
2151 		 * of view, regardless of the value of nd_ifinfo.flags.
2152 		 * The second condition is a bit tricky; we skip
2153 		 * if the gateway is our own address, which is
2154 		 * sometimes used to install a route to a p2p link.
2155 		 */
2156 		if (!nd6_is_addr_neighbor(gw6, ifp) ||
2157 		    in6ifa_ifpwithaddr(ifp, &gw6->sin6_addr)) {
2158 			/*
2159 			 * We allow this kind of tricky route only
2160 			 * when the outgoing interface is p2p.
2161 			 * XXX: we may need a more generic rule here.
2162 			 */
2163 			if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
2164 				senderr(EHOSTUNREACH);
2165 
2166 			goto sendpkt;
2167 		}
2168 	}
2169 
2170 	/*
2171 	 * Address resolution or Neighbor Unreachability Detection
2172 	 * for the next hop.
2173 	 * At this point, the destination of the packet must be a unicast
2174 	 * or an anycast address(i.e. not a multicast).
2175 	 */
2176 
2177 	/* Look up the neighbor cache for the nexthop */
2178 	ln = nd6_lookup(&dst->sin6_addr, ifp, true);
2179 	if ((ln == NULL) && nd6_is_addr_neighbor(dst, ifp))  {
2180 		/*
2181 		 * Since nd6_is_addr_neighbor() internally calls nd6_lookup(),
2182 		 * the condition below is not very efficient.  But we believe
2183 		 * it is tolerable, because this should be a rare case.
2184 		 */
2185 		ln = nd6_create(&dst->sin6_addr, ifp);
2186 		if (ln != NULL)
2187 			created = true;
2188 	}
2189 
2190 	if (ln == NULL) {
2191 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0 &&
2192 		    !(ND_IFINFO(ifp)->flags & ND6_IFF_PERFORMNUD)) {
2193 			log(LOG_DEBUG,
2194 			    "nd6_output: can't allocate llinfo for %s "
2195 			    "(ln=%p, rt=%p)\n",
2196 			    ip6_sprintf(&dst->sin6_addr), ln, rt);
2197 			senderr(EIO);	/* XXX: good error? */
2198 		}
2199 		goto sendpkt;	/* send anyway */
2200 	}
2201 
2202 	LLE_WLOCK_ASSERT(ln);
2203 
2204 	/* We don't have to do link-layer address resolution on a p2p link. */
2205 	if ((ifp->if_flags & IFF_POINTOPOINT) != 0 &&
2206 	    ln->ln_state < ND6_LLINFO_REACHABLE) {
2207 		ln->ln_state = ND6_LLINFO_STALE;
2208 		nd6_llinfo_settimer(ln, nd6_gctimer * hz);
2209 	}
2210 
2211 	/*
2212 	 * The first time we send a packet to a neighbor whose entry is
2213 	 * STALE, we have to change the state to DELAY and a sets a timer to
2214 	 * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do
2215 	 * neighbor unreachability detection on expiration.
2216 	 * (RFC 2461 7.3.3)
2217 	 */
2218 	if (ln->ln_state == ND6_LLINFO_STALE) {
2219 		ln->ln_asked = 0;
2220 		ln->ln_state = ND6_LLINFO_DELAY;
2221 		nd6_llinfo_settimer(ln, nd6_delay * hz);
2222 	}
2223 
2224 	/*
2225 	 * If the neighbor cache entry has a state other than INCOMPLETE
2226 	 * (i.e. its link-layer address is already resolved), just
2227 	 * send the packet.
2228 	 */
2229 	if (ln->ln_state > ND6_LLINFO_INCOMPLETE)
2230 		goto sendpkt;
2231 
2232 	/*
2233 	 * There is a neighbor cache entry, but no ethernet address
2234 	 * response yet.  Append this latest packet to the end of the
2235 	 * packet queue in the mbuf, unless the number of the packet
2236 	 * does not exceed nd6_maxqueuelen.  When it exceeds nd6_maxqueuelen,
2237 	 * the oldest packet in the queue will be removed.
2238 	 */
2239 	if (ln->ln_state == ND6_LLINFO_NOSTATE)
2240 		ln->ln_state = ND6_LLINFO_INCOMPLETE;
2241 	if (ln->ln_hold) {
2242 		struct mbuf *m_hold;
2243 		int i;
2244 
2245 		i = 0;
2246 		for (m_hold = ln->ln_hold; m_hold; m_hold = m_hold->m_nextpkt) {
2247 			i++;
2248 			if (m_hold->m_nextpkt == NULL) {
2249 				m_hold->m_nextpkt = m;
2250 				break;
2251 			}
2252 		}
2253 		while (i >= nd6_maxqueuelen) {
2254 			m_hold = ln->ln_hold;
2255 			ln->ln_hold = ln->ln_hold->m_nextpkt;
2256 			m_freem(m_hold);
2257 			i--;
2258 		}
2259 	} else {
2260 		ln->ln_hold = m;
2261 	}
2262 
2263 	/*
2264 	 * If there has been no NS for the neighbor after entering the
2265 	 * INCOMPLETE state, send the first solicitation.
2266 	 */
2267 	if (!ND6_LLINFO_PERMANENT(ln) && ln->ln_asked == 0) {
2268 		struct in6_addr src, *psrc;
2269 
2270 		ln->ln_asked++;
2271 		nd6_llinfo_settimer(ln, ND_IFINFO(ifp)->retrans * hz / 1000);
2272 		psrc = nd6_llinfo_get_holdsrc(ln, &src);
2273 		LLE_WUNLOCK(ln);
2274 		ln = NULL;
2275 		nd6_ns_output(ifp, NULL, &dst->sin6_addr, psrc, 0);
2276 	} else {
2277 		/* We did the lookup so we need to do the unlock here. */
2278 		LLE_WUNLOCK(ln);
2279 	}
2280 
2281 	error = 0;
2282 	goto exit;
2283 
2284   sendpkt:
2285 	/* discard the packet if IPv6 operation is disabled on the interface */
2286 	if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED)) {
2287 		error = ENETDOWN; /* better error? */
2288 		goto bad;
2289 	}
2290 
2291 	if (ln != NULL)
2292 		LLE_WUNLOCK(ln);
2293 
2294 #ifndef NET_MPSAFE
2295 	KERNEL_LOCK(1, NULL);
2296 #endif
2297 	if ((ifp->if_flags & IFF_LOOPBACK) != 0)
2298 		error = (*ifp->if_output)(origifp, m, sin6tocsa(dst), rt);
2299 	else
2300 		error = (*ifp->if_output)(ifp, m, sin6tocsa(dst), rt);
2301 #ifndef NET_MPSAFE
2302 	KERNEL_UNLOCK_ONE(NULL);
2303 #endif
2304 	goto exit;
2305 
2306   bad:
2307 	if (m != NULL)
2308 		m_freem(m);
2309   exit:
2310 	if (created)
2311 		nd6_gc_neighbors(LLTABLE6(ifp));
2312 
2313 	return error;
2314 #undef senderr
2315 }
2316 
2317 int
2318 nd6_need_cache(struct ifnet *ifp)
2319 {
2320 	/*
2321 	 * XXX: we currently do not make neighbor cache on any interface
2322 	 * other than ARCnet, Ethernet, FDDI and GIF.
2323 	 *
2324 	 * RFC2893 says:
2325 	 * - unidirectional tunnels needs no ND
2326 	 */
2327 	switch (ifp->if_type) {
2328 	case IFT_ARCNET:
2329 	case IFT_ETHER:
2330 	case IFT_FDDI:
2331 	case IFT_IEEE1394:
2332 	case IFT_CARP:
2333 	case IFT_GIF:		/* XXX need more cases? */
2334 	case IFT_PPP:
2335 	case IFT_TUNNEL:
2336 		return 1;
2337 	default:
2338 		return 0;
2339 	}
2340 }
2341 
2342 /*
2343  * Add pernament ND6 link-layer record for given
2344  * interface address.
2345  *
2346  * Very similar to IPv4 arp_ifinit(), but:
2347  * 1) IPv6 DAD is performed in different place
2348  * 2) It is called by IPv6 protocol stack in contrast to
2349  * arp_ifinit() which is typically called in SIOCSIFADDR
2350  * driver ioctl handler.
2351  *
2352  */
2353 int
2354 nd6_add_ifa_lle(struct in6_ifaddr *ia)
2355 {
2356 	struct ifnet *ifp;
2357 	struct llentry *ln;
2358 
2359 	ifp = ia->ia_ifa.ifa_ifp;
2360 	if (nd6_need_cache(ifp) == 0)
2361 		return 0;
2362 	ia->ia_ifa.ifa_rtrequest = nd6_rtrequest;
2363 	ia->ia_ifa.ifa_flags = RTF_CONNECTED;
2364 
2365 	IF_AFDATA_WLOCK(ifp);
2366 	ln = lla_create(LLTABLE6(ifp), LLE_IFADDR | LLE_EXCLUSIVE,
2367 	    (struct sockaddr *)&ia->ia_addr);
2368 	IF_AFDATA_WUNLOCK(ifp);
2369 	if (ln == NULL)
2370 		return ENOBUFS;
2371 
2372 	ln->la_expire = 0;  /* for IPv6 this means permanent */
2373 	ln->ln_state = ND6_LLINFO_REACHABLE;
2374 
2375 	LLE_WUNLOCK(ln);
2376 	return 0;
2377 }
2378 
2379 /*
2380  * Removes ALL lle records for interface address prefix.
2381  * XXXME: That's probably not we really want to do, we need
2382  * to remove address record only and keep other records
2383  * until we determine if given prefix is really going
2384  * to be removed.
2385  */
2386 void
2387 nd6_rem_ifa_lle(struct in6_ifaddr *ia)
2388 {
2389 	struct sockaddr_in6 mask, addr;
2390 
2391 	memcpy(&addr, &ia->ia_addr, sizeof(ia->ia_addr));
2392 	memcpy(&mask, &ia->ia_prefixmask, sizeof(ia->ia_prefixmask));
2393 	lltable_prefix_free(AF_INET6, (struct sockaddr *)&addr,
2394 	    (struct sockaddr *)&mask, LLE_STATIC);
2395 }
2396 
2397 int
2398 nd6_storelladdr(const struct ifnet *ifp, const struct rtentry *rt,
2399     struct mbuf *m, const struct sockaddr *dst, uint8_t *lldst,
2400     size_t dstsize)
2401 {
2402 	struct llentry *ln;
2403 
2404 	if (m->m_flags & M_MCAST) {
2405 		switch (ifp->if_type) {
2406 		case IFT_ETHER:
2407 		case IFT_FDDI:
2408 			ETHER_MAP_IPV6_MULTICAST(&satocsin6(dst)->sin6_addr,
2409 			    lldst);
2410 			return 1;
2411 		case IFT_IEEE1394:
2412 			memcpy(lldst, ifp->if_broadcastaddr,
2413 			    MIN(dstsize, ifp->if_addrlen));
2414 			return 1;
2415 		case IFT_ARCNET:
2416 			*lldst = 0;
2417 			return 1;
2418 		default:
2419 			m_freem(m);
2420 			return 0;
2421 		}
2422 	}
2423 
2424 	/*
2425 	 * the entry should have been created in nd6_store_lladdr
2426 	 */
2427 	ln = nd6_lookup(&satocsin6(dst)->sin6_addr, ifp, false);
2428 	if ((ln == NULL) || !(ln->la_flags & LLE_VALID)) {
2429 		if (ln != NULL)
2430 			LLE_RUNLOCK(ln);
2431 		/* this could happen, if we could not allocate memory */
2432 		m_freem(m);
2433 		return 0;
2434 	}
2435 
2436 	/* XXX llentry should have addrlen? */
2437 #if 0
2438 	sdl = satocsdl(rt->rt_gateway);
2439 	if (sdl->sdl_alen == 0 || sdl->sdl_alen > dstsize) {
2440 		char sbuf[INET6_ADDRSTRLEN];
2441 		char dbuf[LINK_ADDRSTRLEN];
2442 		/* this should be impossible, but we bark here for debugging */
2443 		printf("%s: sdl_alen == %" PRIu8 ", if=%s, dst=%s, sdl=%s\n",
2444 		    __func__, sdl->sdl_alen, if_name(ifp),
2445 		    IN6_PRINT(sbuf, &satocsin6(dst)->sin6_addr),
2446 		    DL_PRINT(dbuf, &sdl->sdl_addr));
2447 		m_freem(m);
2448 		return 0;
2449 	}
2450 #endif
2451 
2452 	memcpy(lldst, &ln->ll_addr, MIN(dstsize, ifp->if_addrlen));
2453 
2454 	LLE_RUNLOCK(ln);
2455 
2456 	return 1;
2457 }
2458 
2459 static void
2460 clear_llinfo_pqueue(struct llentry *ln)
2461 {
2462 	struct mbuf *m_hold, *m_hold_next;
2463 
2464 	for (m_hold = ln->ln_hold; m_hold; m_hold = m_hold_next) {
2465 		m_hold_next = m_hold->m_nextpkt;
2466 		m_hold->m_nextpkt = NULL;
2467 		m_freem(m_hold);
2468 	}
2469 
2470 	ln->ln_hold = NULL;
2471 	return;
2472 }
2473 
2474 int
2475 nd6_sysctl(
2476     int name,
2477     void *oldp,	/* syscall arg, need copyout */
2478     size_t *oldlenp,
2479     void *newp,	/* syscall arg, need copyin */
2480     size_t newlen
2481 )
2482 {
2483 	void *p;
2484 	size_t ol;
2485 	int error;
2486 
2487 	error = 0;
2488 
2489 	if (newp)
2490 		return EPERM;
2491 	if (oldp && !oldlenp)
2492 		return EINVAL;
2493 	ol = oldlenp ? *oldlenp : 0;
2494 
2495 	if (oldp) {
2496 		p = malloc(*oldlenp, M_TEMP, M_WAITOK);
2497 		if (p == NULL)
2498 			return ENOMEM;
2499 	} else
2500 		p = NULL;
2501 	switch (name) {
2502 	case ICMPV6CTL_ND6_DRLIST:
2503 		error = fill_drlist(p, oldlenp, ol);
2504 		if (!error && p != NULL && oldp != NULL)
2505 			error = copyout(p, oldp, *oldlenp);
2506 		break;
2507 
2508 	case ICMPV6CTL_ND6_PRLIST:
2509 		error = fill_prlist(p, oldlenp, ol);
2510 		if (!error && p != NULL && oldp != NULL)
2511 			error = copyout(p, oldp, *oldlenp);
2512 		break;
2513 
2514 	case ICMPV6CTL_ND6_MAXQLEN:
2515 		break;
2516 
2517 	default:
2518 		error = ENOPROTOOPT;
2519 		break;
2520 	}
2521 	if (p)
2522 		free(p, M_TEMP);
2523 
2524 	return error;
2525 }
2526 
2527 static int
2528 fill_drlist(void *oldp, size_t *oldlenp, size_t ol)
2529 {
2530 	int error = 0, s;
2531 	struct in6_defrouter *d = NULL, *de = NULL;
2532 	struct nd_defrouter *dr;
2533 	size_t l;
2534 
2535 	s = splsoftnet();
2536 
2537 	if (oldp) {
2538 		d = (struct in6_defrouter *)oldp;
2539 		de = (struct in6_defrouter *)((char *)oldp + *oldlenp);
2540 	}
2541 	l = 0;
2542 
2543 	TAILQ_FOREACH(dr, &nd_defrouter, dr_entry) {
2544 
2545 		if (oldp && d + 1 <= de) {
2546 			memset(d, 0, sizeof(*d));
2547 			sockaddr_in6_init(&d->rtaddr, &dr->rtaddr, 0, 0, 0);
2548 			if (sa6_recoverscope(&d->rtaddr)) {
2549 				log(LOG_ERR,
2550 				    "scope error in router list (%s)\n",
2551 				    ip6_sprintf(&d->rtaddr.sin6_addr));
2552 				/* XXX: press on... */
2553 			}
2554 			d->flags = dr->flags;
2555 			d->rtlifetime = dr->rtlifetime;
2556 			d->expire = dr->expire ?
2557 			    time_mono_to_wall(dr->expire) : 0;
2558 			d->if_index = dr->ifp->if_index;
2559 		}
2560 
2561 		l += sizeof(*d);
2562 		if (d)
2563 			d++;
2564 	}
2565 
2566 	if (oldp) {
2567 		if (l > ol)
2568 			error = ENOMEM;
2569 	}
2570 	if (oldlenp)
2571 		*oldlenp = l;	/* (void *)d - (void *)oldp */
2572 
2573 	splx(s);
2574 
2575 	return error;
2576 }
2577 
2578 static int
2579 fill_prlist(void *oldp, size_t *oldlenp, size_t ol)
2580 {
2581 	int error = 0, s;
2582 	struct nd_prefix *pr;
2583 	uint8_t *p = NULL, *ps = NULL;
2584 	uint8_t *pe = NULL;
2585 	size_t l;
2586 
2587 	s = splsoftnet();
2588 
2589 	if (oldp) {
2590 		ps = p = (uint8_t*)oldp;
2591 		pe = (uint8_t*)oldp + *oldlenp;
2592 	}
2593 	l = 0;
2594 
2595 	LIST_FOREACH(pr, &nd_prefix, ndpr_entry) {
2596 		u_short advrtrs;
2597 		struct sockaddr_in6 sin6;
2598 		struct nd_pfxrouter *pfr;
2599 		struct in6_prefix pfx;
2600 
2601 		if (oldp && p + sizeof(struct in6_prefix) <= pe)
2602 		{
2603 			memset(&pfx, 0, sizeof(pfx));
2604 			ps = p;
2605 			pfx.prefix = pr->ndpr_prefix;
2606 
2607 			if (sa6_recoverscope(&pfx.prefix)) {
2608 				log(LOG_ERR,
2609 				    "scope error in prefix list (%s)\n",
2610 				    ip6_sprintf(&pfx.prefix.sin6_addr));
2611 				/* XXX: press on... */
2612 			}
2613 			pfx.raflags = pr->ndpr_raf;
2614 			pfx.prefixlen = pr->ndpr_plen;
2615 			pfx.vltime = pr->ndpr_vltime;
2616 			pfx.pltime = pr->ndpr_pltime;
2617 			pfx.if_index = pr->ndpr_ifp->if_index;
2618 			if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME)
2619 				pfx.expire = 0;
2620 			else {
2621 				time_t maxexpire;
2622 
2623 				/* XXX: we assume time_t is signed. */
2624 				maxexpire = (-1) &
2625 				    ~((time_t)1 <<
2626 				    ((sizeof(maxexpire) * 8) - 1));
2627 				if (pr->ndpr_vltime <
2628 				    maxexpire - pr->ndpr_lastupdate) {
2629 					pfx.expire = pr->ndpr_lastupdate +
2630 						pr->ndpr_vltime;
2631 				} else
2632 					pfx.expire = maxexpire;
2633 			}
2634 			pfx.refcnt = pr->ndpr_refcnt;
2635 			pfx.flags = pr->ndpr_stateflags;
2636 			pfx.origin = PR_ORIG_RA;
2637 
2638 			p += sizeof(pfx); l += sizeof(pfx);
2639 
2640 			advrtrs = 0;
2641 			LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) {
2642 				if (p + sizeof(sin6) > pe) {
2643 					advrtrs++;
2644 					continue;
2645 				}
2646 
2647 				sockaddr_in6_init(&sin6, &pfr->router->rtaddr,
2648 				    0, 0, 0);
2649 				if (sa6_recoverscope(&sin6)) {
2650 					log(LOG_ERR,
2651 					    "scope error in "
2652 					    "prefix list (%s)\n",
2653 					    ip6_sprintf(&pfr->router->rtaddr));
2654 				}
2655 				advrtrs++;
2656 				memcpy(p, &sin6, sizeof(sin6));
2657 				p += sizeof(sin6);
2658 				l += sizeof(sin6);
2659 			}
2660 			pfx.advrtrs = advrtrs;
2661 			memcpy(ps, &pfx, sizeof(pfx));
2662 		}
2663 		else {
2664 			l += sizeof(pfx);
2665 			advrtrs = 0;
2666 			LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) {
2667 				advrtrs++;
2668 				l += sizeof(sin6);
2669 			}
2670 		}
2671 	}
2672 
2673 	if (oldp) {
2674 		*oldlenp = l;	/* (void *)d - (void *)oldp */
2675 		if (l > ol)
2676 			error = ENOMEM;
2677 	} else
2678 		*oldlenp = l;
2679 
2680 	splx(s);
2681 
2682 	return error;
2683 }
2684