xref: /dragonfly/sys/netinet6/nd6.c (revision cfd1aba3)
1 /*	$FreeBSD: src/sys/netinet6/nd6.c,v 1.2.2.15 2003/05/06 06:46:58 suz Exp $	*/
2 /*	$KAME: nd6.c,v 1.144 2001/05/24 07:44:00 itojun Exp $	*/
3 
4 /*
5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * XXX
35  * KAME 970409 note:
36  * BSD/OS version heavily modifies this code, related to llinfo.
37  * Since we don't have BSD/OS version of net/route.c in our hand,
38  * I left the code mostly as it was in 970310.  -- itojun
39  */
40 
41 #include "opt_inet.h"
42 #include "opt_inet6.h"
43 
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/callout.h>
47 #include <sys/malloc.h>
48 #include <sys/mbuf.h>
49 #include <sys/socket.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/syslog.h>
56 #include <sys/queue.h>
57 #include <sys/sysctl.h>
58 #include <sys/mutex.h>
59 
60 #include <sys/thread2.h>
61 #include <sys/mutex2.h>
62 
63 #include <net/if.h>
64 #include <net/if_dl.h>
65 #include <net/if_types.h>
66 #include <net/if_atm.h>
67 #include <net/route.h>
68 
69 #include <netinet/in.h>
70 #include <netinet/if_ether.h>
71 #include <netinet6/in6_var.h>
72 #include <netinet/ip6.h>
73 #include <netinet6/ip6_var.h>
74 #include <netinet6/nd6.h>
75 #include <netinet6/in6_prefix.h>
76 #include <netinet/icmp6.h>
77 
78 #include <net/net_osdep.h>
79 
80 #define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */
81 #define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */
82 
83 #define SIN6(s) ((struct sockaddr_in6 *)s)
84 #define SDL(s) ((struct sockaddr_dl *)s)
85 
86 /* timer values */
87 int	nd6_prune	= 1;	/* walk list every 1 seconds */
88 int	nd6_delay	= 5;	/* delay first probe time 5 second */
89 int	nd6_umaxtries	= 3;	/* maximum unicast query */
90 int	nd6_mmaxtries	= 3;	/* maximum multicast query */
91 int	nd6_useloopback = 1;	/* use loopback interface for local traffic */
92 int	nd6_gctimer	= (60 * 60 * 24); /* 1 day: garbage collection timer */
93 
94 /* preventing too many loops in ND option parsing */
95 int nd6_maxndopt = 10;	/* max # of ND options allowed */
96 
97 int nd6_maxnudhint = 0;	/* max # of subsequent upper layer hints */
98 
99 #ifdef ND6_DEBUG
100 int nd6_debug = 1;
101 #else
102 int nd6_debug = 0;
103 #endif
104 
105 /* for debugging? */
106 static int nd6_inuse, nd6_allocated;
107 
108 struct llinfo_nd6 llinfo_nd6 = {&llinfo_nd6, &llinfo_nd6};
109 struct nd_drhead nd_defrouter;
110 struct nd_prhead nd_prefix = { 0 };
111 struct mtx nd6_mtx = MTX_INITIALIZER;
112 
113 int nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL;
114 static struct sockaddr_in6 all1_sa;
115 
116 static void nd6_setmtu0 (struct ifnet *, struct nd_ifinfo *);
117 static void nd6_slowtimo (void *);
118 static int regen_tmpaddr (struct in6_ifaddr *);
119 
120 struct callout nd6_slowtimo_ch;
121 struct callout nd6_timer_ch;
122 extern struct callout in6_tmpaddrtimer_ch;
123 
124 void
125 nd6_init(void)
126 {
127 	static int nd6_init_done = 0;
128 	int i;
129 
130 	if (nd6_init_done) {
131 		log(LOG_NOTICE, "nd6_init called more than once(ignored)\n");
132 		return;
133 	}
134 
135 	all1_sa.sin6_family = AF_INET6;
136 	all1_sa.sin6_len = sizeof(struct sockaddr_in6);
137 	for (i = 0; i < sizeof(all1_sa.sin6_addr); i++)
138 		all1_sa.sin6_addr.s6_addr[i] = 0xff;
139 
140 	/* initialization of the default router list */
141 	TAILQ_INIT(&nd_defrouter);
142 
143 	nd6_init_done = 1;
144 
145 	/* start timer */
146 	callout_init(&nd6_slowtimo_ch);
147 	callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
148 	    nd6_slowtimo, NULL);
149 }
150 
151 struct nd_ifinfo *
152 nd6_ifattach(struct ifnet *ifp)
153 {
154 	struct nd_ifinfo *nd;
155 
156 	nd = (struct nd_ifinfo *)kmalloc(sizeof(*nd), M_IP6NDP,
157 	    M_WAITOK | M_ZERO);
158 
159 	nd->initialized = 1;
160 
161 	nd->linkmtu = ifindex2ifnet[ifp->if_index]->if_mtu;
162 	nd->chlim = IPV6_DEFHLIM;
163 	nd->basereachable = REACHABLE_TIME;
164 	nd->reachable = ND_COMPUTE_RTIME(nd->basereachable);
165 	nd->retrans = RETRANS_TIMER;
166 	nd->receivedra = 0;
167 
168 	/*
169 	 * Note that the default value of ip6_accept_rtadv is 0, which means
170 	 * we won't accept RAs by default even if we set ND6_IFF_ACCEPT_RTADV
171 	 * here.
172 	 */
173 	nd->flags = (ND6_IFF_PERFORMNUD | ND6_IFF_ACCEPT_RTADV);
174 
175 	/* XXX: we cannot call nd6_setmtu since ifp is not fully initialized */
176 	nd6_setmtu0(ifp, nd);
177 	return nd;
178 }
179 
180 void
181 nd6_ifdetach(struct nd_ifinfo *nd)
182 {
183 	kfree(nd, M_IP6NDP);
184 }
185 
186 /*
187  * Reset ND level link MTU. This function is called when the physical MTU
188  * changes, which means we might have to adjust the ND level MTU.
189  */
190 void
191 nd6_setmtu(struct ifnet *ifp)
192 {
193 	nd6_setmtu0(ifp, ND_IFINFO(ifp));
194 }
195 
196 /* XXX todo: do not maintain copy of ifp->if_mtu in ndi->maxmtu */
197 void
198 nd6_setmtu0(struct ifnet *ifp, struct nd_ifinfo *ndi)
199 {
200 	u_long oldmaxmtu;
201 	u_long oldlinkmtu;
202 
203 	oldmaxmtu = ndi->maxmtu;
204 	oldlinkmtu = ndi->linkmtu;
205 
206 	switch (ifp->if_type) {
207 	case IFT_ETHER:
208 		ndi->maxmtu = MIN(ETHERMTU, ifp->if_mtu);
209 		break;
210 	case IFT_ATM:
211 		ndi->maxmtu = MIN(ATMMTU, ifp->if_mtu);
212 		break;
213 	case IFT_IEEE1394:	/* XXX should be IEEE1394MTU(1500) */
214 		ndi->maxmtu = MIN(ETHERMTU, ifp->if_mtu);
215 		break;
216 #ifdef IFT_IEEE80211
217 	case IFT_IEEE80211:	/* XXX should be IEEE80211MTU(1500) */
218 		ndi->maxmtu = MIN(ETHERMTU, ifp->if_mtu);
219 		break;
220 #endif
221 	default:
222 		ndi->maxmtu = ifp->if_mtu;
223 		break;
224 	}
225 
226 	if (oldmaxmtu != ndi->maxmtu) {
227 		/*
228 		 * If the ND level MTU is not set yet, or if the maxmtu
229 		 * is reset to a smaller value than the ND level MTU,
230 		 * also reset the ND level MTU.
231 		 */
232 		if (ndi->linkmtu == 0 ||
233 		    ndi->maxmtu < ndi->linkmtu) {
234 			ndi->linkmtu = ndi->maxmtu;
235 			/* also adjust in6_maxmtu if necessary. */
236 			if (oldlinkmtu == 0) {
237 				/*
238 				 * XXX: the case analysis is grotty, but
239 				 * it is not efficient to call in6_setmaxmtu()
240 				 * here when we are during the initialization
241 				 * procedure.
242 				 */
243 				if (in6_maxmtu < ndi->linkmtu)
244 					in6_maxmtu = ndi->linkmtu;
245 			} else
246 				in6_setmaxmtu();
247 		}
248 	}
249 #undef MIN
250 }
251 
252 void
253 nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts)
254 {
255 	bzero(ndopts, sizeof(*ndopts));
256 	ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
257 	ndopts->nd_opts_last
258 		= (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len);
259 
260 	if (icmp6len == 0) {
261 		ndopts->nd_opts_done = 1;
262 		ndopts->nd_opts_search = NULL;
263 	}
264 }
265 
266 /*
267  * Take one ND option.
268  */
269 struct nd_opt_hdr *
270 nd6_option(union nd_opts *ndopts)
271 {
272 	struct nd_opt_hdr *nd_opt;
273 	int olen;
274 
275 	if (!ndopts)
276 		panic("ndopts == NULL in nd6_option");
277 	if (!ndopts->nd_opts_last)
278 		panic("uninitialized ndopts in nd6_option");
279 	if (!ndopts->nd_opts_search)
280 		return NULL;
281 	if (ndopts->nd_opts_done)
282 		return NULL;
283 
284 	nd_opt = ndopts->nd_opts_search;
285 
286 	/* make sure nd_opt_len is inside the buffer */
287 	if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) {
288 		bzero(ndopts, sizeof(*ndopts));
289 		return NULL;
290 	}
291 
292 	olen = nd_opt->nd_opt_len << 3;
293 	if (olen == 0) {
294 		/*
295 		 * Message validation requires that all included
296 		 * options have a length that is greater than zero.
297 		 */
298 		bzero(ndopts, sizeof(*ndopts));
299 		return NULL;
300 	}
301 
302 	ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen);
303 	if (ndopts->nd_opts_search > ndopts->nd_opts_last) {
304 		/* option overruns the end of buffer, invalid */
305 		bzero(ndopts, sizeof(*ndopts));
306 		return NULL;
307 	} else if (ndopts->nd_opts_search == ndopts->nd_opts_last) {
308 		/* reached the end of options chain */
309 		ndopts->nd_opts_done = 1;
310 		ndopts->nd_opts_search = NULL;
311 	}
312 	return nd_opt;
313 }
314 
315 /*
316  * Parse multiple ND options.
317  * This function is much easier to use, for ND routines that do not need
318  * multiple options of the same type.
319  */
320 int
321 nd6_options(union nd_opts *ndopts)
322 {
323 	struct nd_opt_hdr *nd_opt;
324 	int i = 0;
325 
326 	if (!ndopts)
327 		panic("ndopts == NULL in nd6_options");
328 	if (!ndopts->nd_opts_last)
329 		panic("uninitialized ndopts in nd6_options");
330 	if (!ndopts->nd_opts_search)
331 		return 0;
332 
333 	while (1) {
334 		nd_opt = nd6_option(ndopts);
335 		if (!nd_opt && !ndopts->nd_opts_last) {
336 			/*
337 			 * Message validation requires that all included
338 			 * options have a length that is greater than zero.
339 			 */
340 			icmp6stat.icp6s_nd_badopt++;
341 			bzero(ndopts, sizeof(*ndopts));
342 			return -1;
343 		}
344 
345 		if (!nd_opt)
346 			goto skip1;
347 
348 		switch (nd_opt->nd_opt_type) {
349 		case ND_OPT_SOURCE_LINKADDR:
350 		case ND_OPT_TARGET_LINKADDR:
351 		case ND_OPT_MTU:
352 		case ND_OPT_REDIRECTED_HEADER:
353 			if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
354 				nd6log((LOG_INFO,
355 				    "duplicated ND6 option found (type=%d)\n",
356 				    nd_opt->nd_opt_type));
357 				/* XXX bark? */
358 			} else {
359 				ndopts->nd_opt_array[nd_opt->nd_opt_type]
360 					= nd_opt;
361 			}
362 			break;
363 		case ND_OPT_PREFIX_INFORMATION:
364 			if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
365 				ndopts->nd_opt_array[nd_opt->nd_opt_type]
366 					= nd_opt;
367 			}
368 			ndopts->nd_opts_pi_end =
369 				(struct nd_opt_prefix_info *)nd_opt;
370 			break;
371 		default:
372 			/*
373 			 * Unknown options must be silently ignored,
374 			 * to accomodate future extension to the protocol.
375 			 */
376 			nd6log((LOG_DEBUG,
377 			    "nd6_options: unsupported option %d - "
378 			    "option ignored\n", nd_opt->nd_opt_type));
379 		}
380 
381 skip1:
382 		i++;
383 		if (i > nd6_maxndopt) {
384 			icmp6stat.icp6s_nd_toomanyopt++;
385 			nd6log((LOG_INFO, "too many loop in nd opt\n"));
386 			break;
387 		}
388 
389 		if (ndopts->nd_opts_done)
390 			break;
391 	}
392 
393 	return 0;
394 }
395 
396 /*
397  * ND6 timer routine to expire default route list and prefix list
398  */
399 void
400 nd6_timer(void *ignored_arg)
401 {
402 	struct llinfo_nd6 *ln;
403 	struct nd_defrouter *dr;
404 	struct nd_prefix *pr;
405 	struct ifnet *ifp;
406 	struct in6_ifaddr *ia6, *nia6;
407 
408 	mtx_lock(&nd6_mtx);
409 	callout_reset(&nd6_timer_ch, nd6_prune * hz,
410 		      nd6_timer, NULL);
411 
412 	ln = llinfo_nd6.ln_next;
413 	while (ln && ln != &llinfo_nd6) {
414 		struct rtentry *rt;
415 		struct sockaddr_in6 *dst;
416 		struct llinfo_nd6 *next = ln->ln_next;
417 		/* XXX: used for the DELAY case only: */
418 		struct nd_ifinfo *ndi = NULL;
419 
420 		if ((rt = ln->ln_rt) == NULL) {
421 			ln = next;
422 			continue;
423 		}
424 		if ((ifp = rt->rt_ifp) == NULL) {
425 			ln = next;
426 			continue;
427 		}
428 		ndi = ND_IFINFO(ifp);
429 		dst = (struct sockaddr_in6 *)rt_key(rt);
430 
431 		if (ln->ln_expire > time_uptime) {
432 			ln = next;
433 			continue;
434 		}
435 
436 		/* sanity check */
437 		if (!rt)
438 			panic("rt=0 in nd6_timer(ln=%p)", ln);
439 		if (rt->rt_llinfo && (struct llinfo_nd6 *)rt->rt_llinfo != ln)
440 			panic("rt_llinfo(%p) is not equal to ln(%p)",
441 			      rt->rt_llinfo, ln);
442 		if (!dst)
443 			panic("dst=0 in nd6_timer(ln=%p)", ln);
444 
445 		switch (ln->ln_state) {
446 		case ND6_LLINFO_INCOMPLETE:
447 			if (ln->ln_asked < nd6_mmaxtries) {
448 				ln->ln_asked++;
449 				ln->ln_expire = time_uptime +
450 					ND_IFINFO(ifp)->retrans / 1000;
451 				nd6_ns_output(ifp, NULL, &dst->sin6_addr,
452 					ln, 0);
453 			} else {
454 				struct mbuf *m = ln->ln_hold;
455 				if (m) {
456 					if (rt->rt_ifp) {
457 						/*
458 						 * Fake rcvif to make ICMP error
459 						 * more helpful in diagnosing
460 						 * for the receiver.
461 						 * XXX: should we consider
462 						 * older rcvif?
463 						 */
464 						m->m_pkthdr.rcvif = rt->rt_ifp;
465 					}
466 					icmp6_error(m, ICMP6_DST_UNREACH,
467 						    ICMP6_DST_UNREACH_ADDR, 0);
468 					ln->ln_hold = NULL;
469 				}
470 				next = nd6_free(rt);
471 			}
472 			break;
473 		case ND6_LLINFO_REACHABLE:
474 			if (ln->ln_expire) {
475 				ln->ln_state = ND6_LLINFO_STALE;
476 				ln->ln_expire = time_uptime + nd6_gctimer;
477 			}
478 			break;
479 
480 		case ND6_LLINFO_STALE:
481 			/* Garbage Collection(RFC 2461 5.3) */
482 			if (ln->ln_expire)
483 				next = nd6_free(rt);
484 			break;
485 
486 		case ND6_LLINFO_DELAY:
487 			if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD)) {
488 				/* We need NUD */
489 				ln->ln_asked = 1;
490 				ln->ln_state = ND6_LLINFO_PROBE;
491 				ln->ln_expire = time_uptime +
492 					ndi->retrans / 1000;
493 				nd6_ns_output(ifp, &dst->sin6_addr,
494 					      &dst->sin6_addr,
495 					      ln, 0);
496 			} else {
497 				ln->ln_state = ND6_LLINFO_STALE; /* XXX */
498 				ln->ln_expire = time_uptime + nd6_gctimer;
499 			}
500 			break;
501 		case ND6_LLINFO_PROBE:
502 			if (ln->ln_asked < nd6_umaxtries) {
503 				ln->ln_asked++;
504 				ln->ln_expire = time_uptime +
505 					ND_IFINFO(ifp)->retrans / 1000;
506 				nd6_ns_output(ifp, &dst->sin6_addr,
507 					       &dst->sin6_addr, ln, 0);
508 			} else {
509 				next = nd6_free(rt);
510 			}
511 			break;
512 		}
513 		ln = next;
514 	}
515 
516 	/* expire default router list */
517 	dr = TAILQ_FIRST(&nd_defrouter);
518 	while (dr) {
519 		if (dr->expire && dr->expire < time_uptime) {
520 			struct nd_defrouter *t;
521 			t = TAILQ_NEXT(dr, dr_entry);
522 			defrtrlist_del(dr);
523 			dr = t;
524 		} else {
525 			dr = TAILQ_NEXT(dr, dr_entry);
526 		}
527 	}
528 
529 	/*
530 	 * expire interface addresses.
531 	 * in the past the loop was inside prefix expiry processing.
532 	 * However, from a stricter speci-confrmance standpoint, we should
533 	 * rather separate address lifetimes and prefix lifetimes.
534 	 */
535 addrloop:
536 	for (ia6 = in6_ifaddr; ia6; ia6 = nia6) {
537 		nia6 = ia6->ia_next;
538 		/* check address lifetime */
539 		if (IFA6_IS_INVALID(ia6)) {
540 			int regen = 0;
541 
542 			/*
543 			 * If the expiring address is temporary, try
544 			 * regenerating a new one.  This would be useful when
545 			 * we suspended a laptop PC, then turned it on after a
546 			 * period that could invalidate all temporary
547 			 * addresses.  Although we may have to restart the
548 			 * loop (see below), it must be after purging the
549 			 * address.  Otherwise, we'd see an infinite loop of
550 			 * regeneration.
551 			 */
552 			if (ip6_use_tempaddr &&
553 			    (ia6->ia6_flags & IN6_IFF_TEMPORARY)) {
554 				if (regen_tmpaddr(ia6) == 0)
555 					regen = 1;
556 			}
557 
558 			in6_purgeaddr(&ia6->ia_ifa);
559 
560 			if (regen)
561 				goto addrloop; /* XXX: see below */
562 		}
563 		if (IFA6_IS_DEPRECATED(ia6)) {
564 			int oldflags = ia6->ia6_flags;
565 
566 			ia6->ia6_flags |= IN6_IFF_DEPRECATED;
567 
568 			/*
569 			 * If a temporary address has just become deprecated,
570 			 * regenerate a new one if possible.
571 			 */
572 			if (ip6_use_tempaddr &&
573 			    (ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
574 			    !(oldflags & IN6_IFF_DEPRECATED)) {
575 
576 				if (regen_tmpaddr(ia6) == 0) {
577 					/*
578 					 * A new temporary address is
579 					 * generated.
580 					 * XXX: this means the address chain
581 					 * has changed while we are still in
582 					 * the loop.  Although the change
583 					 * would not cause disaster (because
584 					 * it's not a deletion, but an
585 					 * addition,) we'd rather restart the
586 					 * loop just for safety.  Or does this
587 					 * significantly reduce performance??
588 					 */
589 					goto addrloop;
590 				}
591 			}
592 		} else {
593 			/*
594 			 * A new RA might have made a deprecated address
595 			 * preferred.
596 			 */
597 			ia6->ia6_flags &= ~IN6_IFF_DEPRECATED;
598 		}
599 	}
600 
601 	/* expire prefix list */
602 	pr = nd_prefix.lh_first;
603 	while (pr) {
604 		/*
605 		 * check prefix lifetime.
606 		 * since pltime is just for autoconf, pltime processing for
607 		 * prefix is not necessary.
608 		 */
609 		if (pr->ndpr_expire && pr->ndpr_expire < time_uptime) {
610 			struct nd_prefix *t;
611 			t = pr->ndpr_next;
612 
613 			/*
614 			 * address expiration and prefix expiration are
615 			 * separate.  NEVER perform in6_purgeaddr here.
616 			 */
617 
618 			prelist_remove(pr);
619 			pr = t;
620 		} else
621 			pr = pr->ndpr_next;
622 	}
623 	mtx_unlock(&nd6_mtx);
624 }
625 
626 static int
627 regen_tmpaddr(struct in6_ifaddr *ia6) /* deprecated/invalidated temporary
628 					 address */
629 {
630 	struct ifaddr_container *ifac;
631 	struct ifnet *ifp;
632 	struct in6_ifaddr *public_ifa6 = NULL;
633 
634 	ifp = ia6->ia_ifa.ifa_ifp;
635 	TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
636 		struct ifaddr *ifa = ifac->ifa;
637 		struct in6_ifaddr *it6;
638 
639 		if (ifa->ifa_addr->sa_family != AF_INET6)
640 			continue;
641 
642 		it6 = (struct in6_ifaddr *)ifa;
643 
644 		/* ignore no autoconf addresses. */
645 		if (!(it6->ia6_flags & IN6_IFF_AUTOCONF))
646 			continue;
647 
648 		/* ignore autoconf addresses with different prefixes. */
649 		if (it6->ia6_ndpr == NULL || it6->ia6_ndpr != ia6->ia6_ndpr)
650 			continue;
651 
652 		/*
653 		 * Now we are looking at an autoconf address with the same
654 		 * prefix as ours.  If the address is temporary and is still
655 		 * preferred, do not create another one.  It would be rare, but
656 		 * could happen, for example, when we resume a laptop PC after
657 		 * a long period.
658 		 */
659 		if ((it6->ia6_flags & IN6_IFF_TEMPORARY) &&
660 		    !IFA6_IS_DEPRECATED(it6)) {
661 			public_ifa6 = NULL;
662 			break;
663 		}
664 
665 		/*
666 		 * This is a public autoconf address that has the same prefix
667 		 * as ours.  If it is preferred, keep it.  We can't break the
668 		 * loop here, because there may be a still-preferred temporary
669 		 * address with the prefix.
670 		 */
671 		if (!IFA6_IS_DEPRECATED(it6))
672 		    public_ifa6 = it6;
673 	}
674 
675 	if (public_ifa6 != NULL) {
676 		int e;
677 
678 		if ((e = in6_tmpifadd(public_ifa6, 0)) != 0) {
679 			log(LOG_NOTICE, "regen_tmpaddr: failed to create a new"
680 			    " tmp addr,errno=%d\n", e);
681 			return (-1);
682 		}
683 		return (0);
684 	}
685 
686 	return (-1);
687 }
688 
689 /*
690  * Nuke neighbor cache/prefix/default router management table, right before
691  * ifp goes away.
692  */
693 void
694 nd6_purge(struct ifnet *ifp)
695 {
696 	struct llinfo_nd6 *ln, *nln;
697 	struct nd_defrouter *dr, *ndr, drany;
698 	struct nd_prefix *pr, *npr;
699 
700 	/* Nuke default router list entries toward ifp */
701 	if ((dr = TAILQ_FIRST(&nd_defrouter)) != NULL) {
702 		/*
703 		 * The first entry of the list may be stored in
704 		 * the routing table, so we'll delete it later.
705 		 */
706 		for (dr = TAILQ_NEXT(dr, dr_entry); dr; dr = ndr) {
707 			ndr = TAILQ_NEXT(dr, dr_entry);
708 			if (dr->ifp == ifp)
709 				defrtrlist_del(dr);
710 		}
711 		dr = TAILQ_FIRST(&nd_defrouter);
712 		if (dr->ifp == ifp)
713 			defrtrlist_del(dr);
714 	}
715 
716 	/* Nuke prefix list entries toward ifp */
717 	for (pr = nd_prefix.lh_first; pr; pr = npr) {
718 		npr = pr->ndpr_next;
719 		if (pr->ndpr_ifp == ifp) {
720 			/*
721 			 * Previously, pr->ndpr_addr is removed as well,
722 			 * but I strongly believe we don't have to do it.
723 			 * nd6_purge() is only called from in6_ifdetach(),
724 			 * which removes all the associated interface addresses
725 			 * by itself.
726 			 * (jinmei@kame.net 20010129)
727 			 */
728 			prelist_remove(pr);
729 		}
730 	}
731 
732 	/* cancel default outgoing interface setting */
733 	if (nd6_defifindex == ifp->if_index)
734 		nd6_setdefaultiface(0);
735 
736 	if (!ip6_forwarding && ip6_accept_rtadv) { /* XXX: too restrictive? */
737 		/* refresh default router list */
738 		bzero(&drany, sizeof(drany));
739 		defrouter_delreq(&drany, 0);
740 		defrouter_select();
741 	}
742 
743 	/*
744 	 * Nuke neighbor cache entries for the ifp.
745 	 * Note that rt->rt_ifp may not be the same as ifp,
746 	 * due to KAME goto ours hack.  See RTM_RESOLVE case in
747 	 * nd6_rtrequest(), and ip6_input().
748 	 */
749 	ln = llinfo_nd6.ln_next;
750 	while (ln && ln != &llinfo_nd6) {
751 		struct rtentry *rt;
752 		struct sockaddr_dl *sdl;
753 
754 		nln = ln->ln_next;
755 		rt = ln->ln_rt;
756 		if (rt && rt->rt_gateway &&
757 		    rt->rt_gateway->sa_family == AF_LINK) {
758 			sdl = (struct sockaddr_dl *)rt->rt_gateway;
759 			if (sdl->sdl_index == ifp->if_index)
760 				nln = nd6_free(rt);
761 		}
762 		ln = nln;
763 	}
764 }
765 
766 struct rtentry *
767 nd6_lookup(struct in6_addr *addr6, int create, struct ifnet *ifp)
768 {
769 	struct rtentry *rt;
770 	struct sockaddr_in6 sin6;
771 
772 	bzero(&sin6, sizeof(sin6));
773 	sin6.sin6_len = sizeof(struct sockaddr_in6);
774 	sin6.sin6_family = AF_INET6;
775 	sin6.sin6_addr = *addr6;
776 
777 	if (create)
778 		rt = rtlookup((struct sockaddr *)&sin6);
779 	else
780 		rt = rtpurelookup((struct sockaddr *)&sin6);
781 	if (rt && !(rt->rt_flags & RTF_LLINFO)) {
782 		/*
783 		 * This is the case for the default route.
784 		 * If we want to create a neighbor cache for the address, we
785 		 * should free the route for the destination and allocate an
786 		 * interface route.
787 		 */
788 		if (create) {
789 			--rt->rt_refcnt;
790 			rt = NULL;
791 		}
792 	}
793 	if (!rt) {
794 		if (create && ifp) {
795 			int e;
796 
797 			/*
798 			 * If no route is available and create is set,
799 			 * we allocate a host route for the destination
800 			 * and treat it like an interface route.
801 			 * This hack is necessary for a neighbor which can't
802 			 * be covered by our own prefix.
803 			 */
804 			struct ifaddr *ifa =
805 				ifaof_ifpforaddr((struct sockaddr *)&sin6, ifp);
806 			if (ifa == NULL)
807 				return (NULL);
808 
809 			/*
810 			 * Create a new route.  RTF_LLINFO is necessary
811 			 * to create a Neighbor Cache entry for the
812 			 * destination in nd6_rtrequest which will be
813 			 * called in rtrequest via ifa->ifa_rtrequest.
814 			 */
815 			if ((e = rtrequest(RTM_ADD, (struct sockaddr *)&sin6,
816 					   ifa->ifa_addr,
817 					   (struct sockaddr *)&all1_sa,
818 					   (ifa->ifa_flags |
819 					    RTF_HOST | RTF_LLINFO) &
820 					   ~RTF_CLONING,
821 					   &rt)) != 0)
822 				log(LOG_ERR,
823 				    "nd6_lookup: failed to add route for a "
824 				    "neighbor(%s), errno=%d\n",
825 				    ip6_sprintf(addr6), e);
826 			if (rt == NULL)
827 				return (NULL);
828 			if (rt->rt_llinfo) {
829 				struct llinfo_nd6 *ln =
830 					(struct llinfo_nd6 *)rt->rt_llinfo;
831 				ln->ln_state = ND6_LLINFO_NOSTATE;
832 			}
833 		} else
834 			return (NULL);
835 	}
836 	rt->rt_refcnt--;
837 	/*
838 	 * Validation for the entry.
839 	 * Note that the check for rt_llinfo is necessary because a cloned
840 	 * route from a parent route that has the L flag (e.g. the default
841 	 * route to a p2p interface) may have the flag, too, while the
842 	 * destination is not actually a neighbor.
843 	 * XXX: we can't use rt->rt_ifp to check for the interface, since
844 	 *      it might be the loopback interface if the entry is for our
845 	 *      own address on a non-loopback interface. Instead, we should
846 	 *      use rt->rt_ifa->ifa_ifp, which would specify the REAL
847 	 *      interface.
848 	 */
849 	if ((rt->rt_flags & RTF_GATEWAY) || !(rt->rt_flags & RTF_LLINFO) ||
850 	    rt->rt_gateway->sa_family != AF_LINK || rt->rt_llinfo == NULL ||
851 	    (ifp && rt->rt_ifa->ifa_ifp != ifp)) {
852 		if (create) {
853 			log(LOG_DEBUG, "nd6_lookup: failed to lookup %s (if = %s)\n",
854 			    ip6_sprintf(addr6), ifp ? if_name(ifp) : "unspec");
855 			/* xxx more logs... kazu */
856 		}
857 		return (NULL);
858 	}
859 	return (rt);
860 }
861 
862 /*
863  * Detect if a given IPv6 address identifies a neighbor on a given link.
864  * XXX: should take care of the destination of a p2p link?
865  */
866 int
867 nd6_is_addr_neighbor(struct sockaddr_in6 *addr, struct ifnet *ifp)
868 {
869 	struct ifaddr_container *ifac;
870 	int i;
871 
872 #define IFADDR6(a) ((((struct in6_ifaddr *)(a))->ia_addr).sin6_addr)
873 #define IFMASK6(a) ((((struct in6_ifaddr *)(a))->ia_prefixmask).sin6_addr)
874 
875 	/*
876 	 * A link-local address is always a neighbor.
877 	 * XXX: we should use the sin6_scope_id field rather than the embedded
878 	 * interface index.
879 	 */
880 	if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr) &&
881 	    ntohs(*(u_int16_t *)&addr->sin6_addr.s6_addr[2]) == ifp->if_index)
882 		return (1);
883 
884 	/*
885 	 * If the address matches one of our addresses,
886 	 * it should be a neighbor.
887 	 */
888 	TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
889 		struct ifaddr *ifa = ifac->ifa;
890 
891 		if (ifa->ifa_addr->sa_family != AF_INET6)
892 			next: continue;
893 
894 		for (i = 0; i < 4; i++) {
895 			if ((IFADDR6(ifa).s6_addr32[i] ^
896 			     addr->sin6_addr.s6_addr32[i]) &
897 			    IFMASK6(ifa).s6_addr32[i])
898 				goto next;
899 		}
900 		return (1);
901 	}
902 
903 	/*
904 	 * Even if the address matches none of our addresses, it might be
905 	 * in the neighbor cache.
906 	 */
907 	if (nd6_lookup(&addr->sin6_addr, 0, ifp) != NULL)
908 		return (1);
909 
910 	return (0);
911 #undef IFADDR6
912 #undef IFMASK6
913 }
914 
915 /*
916  * Free an nd6 llinfo entry.
917  */
918 struct llinfo_nd6 *
919 nd6_free(struct rtentry *rt)
920 {
921 	struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo, *next;
922 	struct in6_addr in6 = ((struct sockaddr_in6 *)rt_key(rt))->sin6_addr;
923 	struct nd_defrouter *dr;
924 
925 	/*
926 	 * we used to have kpfctlinput(PRC_HOSTDEAD) here.
927 	 * even though it is not harmful, it was not really necessary.
928 	 */
929 
930 	if (!ip6_forwarding && ip6_accept_rtadv) { /* XXX: too restrictive? */
931 		mtx_lock(&nd6_mtx);
932 		dr = defrouter_lookup(&((struct sockaddr_in6 *)rt_key(rt))->sin6_addr,
933 				      rt->rt_ifp);
934 
935 		if (ln->ln_router || dr) {
936 			/*
937 			 * rt6_flush must be called whether or not the neighbor
938 			 * is in the Default Router List.
939 			 * See a corresponding comment in nd6_na_input().
940 			 */
941 			rt6_flush(&in6, rt->rt_ifp);
942 		}
943 
944 		if (dr) {
945 			/*
946 			 * Unreachablity of a router might affect the default
947 			 * router selection and on-link detection of advertised
948 			 * prefixes.
949 			 */
950 
951 			/*
952 			 * Temporarily fake the state to choose a new default
953 			 * router and to perform on-link determination of
954 			 * prefixes correctly.
955 			 * Below the state will be set correctly,
956 			 * or the entry itself will be deleted.
957 			 */
958 			ln->ln_state = ND6_LLINFO_INCOMPLETE;
959 
960 			/*
961 			 * Since defrouter_select() does not affect the
962 			 * on-link determination and MIP6 needs the check
963 			 * before the default router selection, we perform
964 			 * the check now.
965 			 */
966 			pfxlist_onlink_check();
967 
968 			if (dr == TAILQ_FIRST(&nd_defrouter)) {
969 				/*
970 				 * It is used as the current default router,
971 				 * so we have to move it to the end of the
972 				 * list and choose a new one.
973 				 * XXX: it is not very efficient if this is
974 				 *      the only router.
975 				 */
976 				TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
977 				TAILQ_INSERT_TAIL(&nd_defrouter, dr, dr_entry);
978 
979 				defrouter_select();
980 			}
981 		}
982 		mtx_unlock(&nd6_mtx);
983 	}
984 
985 	/*
986 	 * Before deleting the entry, remember the next entry as the
987 	 * return value.  We need this because pfxlist_onlink_check() above
988 	 * might have freed other entries (particularly the old next entry) as
989 	 * a side effect (XXX).
990 	 */
991 	next = ln->ln_next;
992 
993 	/*
994 	 * Detach the route from the routing tree and the list of neighbor
995 	 * caches, and disable the route entry not to be used in already
996 	 * cached routes.
997 	 */
998 	rtrequest(RTM_DELETE, rt_key(rt), NULL, rt_mask(rt), 0, NULL);
999 
1000 	return (next);
1001 }
1002 
1003 /*
1004  * Upper-layer reachability hint for Neighbor Unreachability Detection.
1005  *
1006  * XXX cost-effective metods?
1007  */
1008 void
1009 nd6_nud_hint(struct rtentry *rt, struct in6_addr *dst6, int force)
1010 {
1011 	struct llinfo_nd6 *ln;
1012 
1013 	/*
1014 	 * If the caller specified "rt", use that.  Otherwise, resolve the
1015 	 * routing table by supplied "dst6".
1016 	 */
1017 	if (!rt) {
1018 		if (!dst6)
1019 			return;
1020 		if (!(rt = nd6_lookup(dst6, 0, NULL)))
1021 			return;
1022 	}
1023 
1024 	if ((rt->rt_flags & RTF_GATEWAY) ||
1025 	    !(rt->rt_flags & RTF_LLINFO) ||
1026 	    rt->rt_llinfo == NULL || rt->rt_gateway == NULL ||
1027 	    rt->rt_gateway->sa_family != AF_LINK) {
1028 		/* This is not a host route. */
1029 		return;
1030 	}
1031 
1032 	ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1033 	if (ln->ln_state < ND6_LLINFO_REACHABLE)
1034 		return;
1035 
1036 	/*
1037 	 * if we get upper-layer reachability confirmation many times,
1038 	 * it is possible we have false information.
1039 	 */
1040 	if (!force) {
1041 		ln->ln_byhint++;
1042 		if (ln->ln_byhint > nd6_maxnudhint)
1043 			return;
1044 	}
1045 
1046 	ln->ln_state = ND6_LLINFO_REACHABLE;
1047 	if (ln->ln_expire)
1048 		ln->ln_expire = time_uptime +
1049 			ND_IFINFO(rt->rt_ifp)->reachable;
1050 }
1051 
1052 void
1053 nd6_rtrequest(int req, struct rtentry *rt)
1054 {
1055 	struct sockaddr *gate = rt->rt_gateway;
1056 	struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1057 	static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
1058 	struct ifnet *ifp = rt->rt_ifp;
1059 	struct ifaddr *ifa;
1060 
1061 	if ((rt->rt_flags & RTF_GATEWAY))
1062 		return;
1063 
1064 	if (nd6_need_cache(ifp) == 0 && !(rt->rt_flags & RTF_HOST)) {
1065 		/*
1066 		 * This is probably an interface direct route for a link
1067 		 * which does not need neighbor caches (e.g. fe80::%lo0/64).
1068 		 * We do not need special treatment below for such a route.
1069 		 * Moreover, the RTF_LLINFO flag which would be set below
1070 		 * would annoy the ndp(8) command.
1071 		 */
1072 		return;
1073 	}
1074 
1075 	if (req == RTM_RESOLVE &&
1076 	    (nd6_need_cache(ifp) == 0 || /* stf case */
1077 	     !nd6_is_addr_neighbor((struct sockaddr_in6 *)rt_key(rt), ifp))) {
1078 		/*
1079 		 * FreeBSD and BSD/OS often make a cloned host route based
1080 		 * on a less-specific route (e.g. the default route).
1081 		 * If the less specific route does not have a "gateway"
1082 		 * (this is the case when the route just goes to a p2p or an
1083 		 * stf interface), we'll mistakenly make a neighbor cache for
1084 		 * the host route, and will see strange neighbor solicitation
1085 		 * for the corresponding destination.  In order to avoid the
1086 		 * confusion, we check if the destination of the route is
1087 		 * a neighbor in terms of neighbor discovery, and stop the
1088 		 * process if not.  Additionally, we remove the LLINFO flag
1089 		 * so that ndp(8) will not try to get the neighbor information
1090 		 * of the destination.
1091 		 */
1092 		rt->rt_flags &= ~RTF_LLINFO;
1093 		return;
1094 	}
1095 
1096 	switch (req) {
1097 	case RTM_ADD:
1098 		/*
1099 		 * There is no backward compatibility :)
1100 		 *
1101 		 * if (!(rt->rt_flags & RTF_HOST) &&
1102 		 *     SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff)
1103 		 *	   rt->rt_flags |= RTF_CLONING;
1104 		 */
1105 		if (rt->rt_flags & (RTF_CLONING | RTF_LLINFO)) {
1106 			/*
1107 			 * Case 1: This route should come from
1108 			 * a route to interface.  RTF_LLINFO flag is set
1109 			 * for a host route whose destination should be
1110 			 * treated as on-link.
1111 			 */
1112 			rt_setgate(rt, rt_key(rt),
1113 				   (struct sockaddr *)&null_sdl,
1114 				   RTL_DONTREPORT);
1115 			gate = rt->rt_gateway;
1116 			SDL(gate)->sdl_type = ifp->if_type;
1117 			SDL(gate)->sdl_index = ifp->if_index;
1118 			if (ln)
1119 				ln->ln_expire = time_uptime;
1120 #if 1
1121 			if (ln && ln->ln_expire == 0) {
1122 				/* kludge for desktops */
1123 #if 0
1124 				kprintf("nd6_rtequest: time.tv_sec is zero; "
1125 				       "treat it as 1\n");
1126 #endif
1127 				ln->ln_expire = 1;
1128 			}
1129 #endif
1130 			if ((rt->rt_flags & RTF_CLONING))
1131 				break;
1132 		}
1133 		/*
1134 		 * In IPv4 code, we try to annonuce new RTF_ANNOUNCE entry here.
1135 		 * We don't do that here since llinfo is not ready yet.
1136 		 *
1137 		 * There are also couple of other things to be discussed:
1138 		 * - unsolicited NA code needs improvement beforehand
1139 		 * - RFC2461 says we MAY send multicast unsolicited NA
1140 		 *   (7.2.6 paragraph 4), however, it also says that we
1141 		 *   SHOULD provide a mechanism to prevent multicast NA storm.
1142 		 *   we don't have anything like it right now.
1143 		 *   note that the mechanism needs a mutual agreement
1144 		 *   between proxies, which means that we need to implement
1145 		 *   a new protocol, or a new kludge.
1146 		 * - from RFC2461 6.2.4, host MUST NOT send an unsolicited NA.
1147 		 *   we need to check ip6forwarding before sending it.
1148 		 *   (or should we allow proxy ND configuration only for
1149 		 *   routers?  there's no mention about proxy ND from hosts)
1150 		 */
1151 #if 0
1152 		/* XXX it does not work */
1153 		if (rt->rt_flags & RTF_ANNOUNCE)
1154 			nd6_na_output(ifp,
1155 			      &SIN6(rt_key(rt))->sin6_addr,
1156 			      &SIN6(rt_key(rt))->sin6_addr,
1157 			      ip6_forwarding ? ND_NA_FLAG_ROUTER : 0,
1158 			      1, NULL);
1159 #endif
1160 		/* FALLTHROUGH */
1161 	case RTM_RESOLVE:
1162 		if ((ifp->if_flags & (IFF_POINTOPOINT | IFF_LOOPBACK)) == 0) {
1163 			/*
1164 			 * Address resolution isn't necessary for a point to
1165 			 * point link, so we can skip this test for a p2p link.
1166 			 */
1167 			if (gate->sa_family != AF_LINK ||
1168 			    gate->sa_len < sizeof(null_sdl)) {
1169 				log(LOG_DEBUG,
1170 				    "nd6_rtrequest: bad gateway value: %s\n",
1171 				    if_name(ifp));
1172 				break;
1173 			}
1174 			SDL(gate)->sdl_type = ifp->if_type;
1175 			SDL(gate)->sdl_index = ifp->if_index;
1176 		}
1177 		if (ln != NULL)
1178 			break;	/* This happens on a route change */
1179 		/*
1180 		 * Case 2: This route may come from cloning, or a manual route
1181 		 * add with a LL address.
1182 		 */
1183 		R_Malloc(ln, struct llinfo_nd6 *, sizeof(*ln));
1184 		rt->rt_llinfo = (caddr_t)ln;
1185 		if (!ln) {
1186 			log(LOG_DEBUG, "nd6_rtrequest: malloc failed\n");
1187 			break;
1188 		}
1189 		nd6_inuse++;
1190 		nd6_allocated++;
1191 		bzero(ln, sizeof(*ln));
1192 		ln->ln_rt = rt;
1193 		/* this is required for "ndp" command. - shin */
1194 		if (req == RTM_ADD) {
1195 		        /*
1196 			 * gate should have some valid AF_LINK entry,
1197 			 * and ln->ln_expire should have some lifetime
1198 			 * which is specified by ndp command.
1199 			 */
1200 			ln->ln_state = ND6_LLINFO_REACHABLE;
1201 			ln->ln_byhint = 0;
1202 		} else {
1203 		        /*
1204 			 * When req == RTM_RESOLVE, rt is created and
1205 			 * initialized in rtrequest(), so rt_expire is 0.
1206 			 */
1207 			ln->ln_state = ND6_LLINFO_NOSTATE;
1208 			ln->ln_expire = time_uptime;
1209 		}
1210 		rt->rt_flags |= RTF_LLINFO;
1211 		ln->ln_next = llinfo_nd6.ln_next;
1212 		llinfo_nd6.ln_next = ln;
1213 		ln->ln_prev = &llinfo_nd6;
1214 		ln->ln_next->ln_prev = ln;
1215 
1216 		/*
1217 		 * check if rt_key(rt) is one of my address assigned
1218 		 * to the interface.
1219 		 */
1220 		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(rt->rt_ifp,
1221 					  &SIN6(rt_key(rt))->sin6_addr);
1222 		if (ifa) {
1223 			caddr_t macp = nd6_ifptomac(ifp);
1224 			ln->ln_expire = 0;
1225 			ln->ln_state = ND6_LLINFO_REACHABLE;
1226 			ln->ln_byhint = 0;
1227 			if (macp) {
1228 				bcopy(macp, LLADDR(SDL(gate)), ifp->if_addrlen);
1229 				SDL(gate)->sdl_alen = ifp->if_addrlen;
1230 			}
1231 			if (nd6_useloopback) {
1232 				rt->rt_ifp = &loif[0];	/* XXX */
1233 				/*
1234 				 * Make sure rt_ifa be equal to the ifaddr
1235 				 * corresponding to the address.
1236 				 * We need this because when we refer
1237 				 * rt_ifa->ia6_flags in ip6_input, we assume
1238 				 * that the rt_ifa points to the address instead
1239 				 * of the loopback address.
1240 				 */
1241 				if (ifa != rt->rt_ifa) {
1242 					IFAFREE(rt->rt_ifa);
1243 					IFAREF(ifa);
1244 					rt->rt_ifa = ifa;
1245 				}
1246 			}
1247 		} else if (rt->rt_flags & RTF_ANNOUNCE) {
1248 			ln->ln_expire = 0;
1249 			ln->ln_state = ND6_LLINFO_REACHABLE;
1250 			ln->ln_byhint = 0;
1251 
1252 			/* join solicited node multicast for proxy ND */
1253 			if (ifp->if_flags & IFF_MULTICAST) {
1254 				struct in6_addr llsol;
1255 				int error;
1256 
1257 				llsol = SIN6(rt_key(rt))->sin6_addr;
1258 				llsol.s6_addr16[0] = htons(0xff02);
1259 				llsol.s6_addr16[1] = htons(ifp->if_index);
1260 				llsol.s6_addr32[1] = 0;
1261 				llsol.s6_addr32[2] = htonl(1);
1262 				llsol.s6_addr8[12] = 0xff;
1263 
1264 				if (!in6_addmulti(&llsol, ifp, &error)) {
1265 					nd6log((LOG_ERR, "%s: failed to join "
1266 					    "%s (errno=%d)\n", if_name(ifp),
1267 					    ip6_sprintf(&llsol), error));
1268 				}
1269 			}
1270 		}
1271 		break;
1272 
1273 	case RTM_DELETE:
1274 		if (!ln)
1275 			break;
1276 		/* leave from solicited node multicast for proxy ND */
1277 		if ((rt->rt_flags & RTF_ANNOUNCE) &&
1278 		    (ifp->if_flags & IFF_MULTICAST)) {
1279 			struct in6_addr llsol;
1280 			struct in6_multi *in6m;
1281 
1282 			llsol = SIN6(rt_key(rt))->sin6_addr;
1283 			llsol.s6_addr16[0] = htons(0xff02);
1284 			llsol.s6_addr16[1] = htons(ifp->if_index);
1285 			llsol.s6_addr32[1] = 0;
1286 			llsol.s6_addr32[2] = htonl(1);
1287 			llsol.s6_addr8[12] = 0xff;
1288 
1289 			IN6_LOOKUP_MULTI(llsol, ifp, in6m);
1290 			if (in6m)
1291 				in6_delmulti(in6m);
1292 		}
1293 		nd6_inuse--;
1294 		ln->ln_next->ln_prev = ln->ln_prev;
1295 		ln->ln_prev->ln_next = ln->ln_next;
1296 		ln->ln_prev = NULL;
1297 		rt->rt_llinfo = 0;
1298 		rt->rt_flags &= ~RTF_LLINFO;
1299 		if (ln->ln_hold)
1300 			m_freem(ln->ln_hold);
1301 		Free((caddr_t)ln);
1302 	}
1303 }
1304 
1305 int
1306 nd6_ioctl(u_long cmd, caddr_t	data, struct ifnet *ifp)
1307 {
1308 	struct in6_drlist *drl = (struct in6_drlist *)data;
1309 	struct in6_prlist *prl = (struct in6_prlist *)data;
1310 	struct in6_ndireq *ndi = (struct in6_ndireq *)data;
1311 	struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data;
1312 	struct in6_ndifreq *ndif = (struct in6_ndifreq *)data;
1313 	struct nd_defrouter *dr, any;
1314 	struct nd_prefix *pr;
1315 	struct rtentry *rt;
1316 	int i = 0, error = 0;
1317 
1318 	switch (cmd) {
1319 	case SIOCGDRLST_IN6:
1320 		/*
1321 		 * obsolete API, use sysctl under net.inet6.icmp6
1322 		 */
1323 		bzero(drl, sizeof(*drl));
1324 		mtx_lock(&nd6_mtx);
1325 		dr = TAILQ_FIRST(&nd_defrouter);
1326 		while (dr && i < DRLSTSIZ) {
1327 			drl->defrouter[i].rtaddr = dr->rtaddr;
1328 			if (IN6_IS_ADDR_LINKLOCAL(&drl->defrouter[i].rtaddr)) {
1329 				/* XXX: need to this hack for KAME stack */
1330 				drl->defrouter[i].rtaddr.s6_addr16[1] = 0;
1331 			} else
1332 				log(LOG_ERR,
1333 				    "default router list contains a "
1334 				    "non-linklocal address(%s)\n",
1335 				    ip6_sprintf(&drl->defrouter[i].rtaddr));
1336 
1337 			drl->defrouter[i].flags = dr->flags;
1338 			drl->defrouter[i].rtlifetime = dr->rtlifetime;
1339 			drl->defrouter[i].expire = dr->expire;
1340 			drl->defrouter[i].if_index = dr->ifp->if_index;
1341 			i++;
1342 			dr = TAILQ_NEXT(dr, dr_entry);
1343 		}
1344 		mtx_unlock(&nd6_mtx);
1345 		break;
1346 	case SIOCGPRLST_IN6:
1347 		/*
1348 		 * obsolete API, use sysctl under net.inet6.icmp6
1349 		 */
1350 		/*
1351 		 * XXX meaning of fields, especialy "raflags", is very
1352 		 * differnet between RA prefix list and RR/static prefix list.
1353 		 * how about separating ioctls into two?
1354 		 */
1355 		bzero(prl, sizeof(*prl));
1356 		mtx_lock(&nd6_mtx);
1357 		pr = nd_prefix.lh_first;
1358 		while (pr && i < PRLSTSIZ) {
1359 			struct nd_pfxrouter *pfr;
1360 			int j;
1361 
1362 			in6_embedscope(&prl->prefix[i].prefix,
1363 			    &pr->ndpr_prefix, NULL, NULL);
1364 			prl->prefix[i].raflags = pr->ndpr_raf;
1365 			prl->prefix[i].prefixlen = pr->ndpr_plen;
1366 			prl->prefix[i].vltime = pr->ndpr_vltime;
1367 			prl->prefix[i].pltime = pr->ndpr_pltime;
1368 			prl->prefix[i].if_index = pr->ndpr_ifp->if_index;
1369 			prl->prefix[i].expire = pr->ndpr_expire;
1370 
1371 			pfr = pr->ndpr_advrtrs.lh_first;
1372 			j = 0;
1373 			while (pfr) {
1374 				if (j < DRLSTSIZ) {
1375 #define RTRADDR prl->prefix[i].advrtr[j]
1376 					RTRADDR = pfr->router->rtaddr;
1377 					if (IN6_IS_ADDR_LINKLOCAL(&RTRADDR)) {
1378 						/* XXX: hack for KAME */
1379 						RTRADDR.s6_addr16[1] = 0;
1380 					} else
1381 						log(LOG_ERR,
1382 						    "a router(%s) advertises "
1383 						    "a prefix with "
1384 						    "non-link local address\n",
1385 						    ip6_sprintf(&RTRADDR));
1386 #undef RTRADDR
1387 				}
1388 				j++;
1389 				pfr = pfr->pfr_next;
1390 			}
1391 			prl->prefix[i].advrtrs = j;
1392 			prl->prefix[i].origin = PR_ORIG_RA;
1393 
1394 			i++;
1395 			pr = pr->ndpr_next;
1396 		}
1397 	      {
1398 		struct rr_prefix *rpp;
1399 
1400 		for (rpp = LIST_FIRST(&rr_prefix); rpp;
1401 		     rpp = LIST_NEXT(rpp, rp_entry)) {
1402 			if (i >= PRLSTSIZ)
1403 				break;
1404 			in6_embedscope(&prl->prefix[i].prefix,
1405 			    &pr->ndpr_prefix, NULL, NULL);
1406 			prl->prefix[i].raflags = rpp->rp_raf;
1407 			prl->prefix[i].prefixlen = rpp->rp_plen;
1408 			prl->prefix[i].vltime = rpp->rp_vltime;
1409 			prl->prefix[i].pltime = rpp->rp_pltime;
1410 			prl->prefix[i].if_index = rpp->rp_ifp->if_index;
1411 			prl->prefix[i].expire = rpp->rp_expire;
1412 			prl->prefix[i].advrtrs = 0;
1413 			prl->prefix[i].origin = rpp->rp_origin;
1414 			i++;
1415 		}
1416 	      }
1417 		mtx_unlock(&nd6_mtx);
1418 
1419 		break;
1420 	case OSIOCGIFINFO_IN6:
1421 		/* XXX: old ndp(8) assumes a positive value for linkmtu. */
1422 		bzero(&ndi->ndi, sizeof(ndi->ndi));
1423 		ndi->ndi.linkmtu = ND_IFINFO(ifp)->linkmtu;
1424 		ndi->ndi.maxmtu = ND_IFINFO(ifp)->maxmtu;
1425 		ndi->ndi.basereachable = ND_IFINFO(ifp)->basereachable;
1426 		ndi->ndi.reachable = ND_IFINFO(ifp)->reachable;
1427 		ndi->ndi.retrans = ND_IFINFO(ifp)->retrans;
1428 		ndi->ndi.flags = ND_IFINFO(ifp)->flags;
1429 		ndi->ndi.recalctm = ND_IFINFO(ifp)->recalctm;
1430 		ndi->ndi.chlim = ND_IFINFO(ifp)->chlim;
1431 		ndi->ndi.receivedra = ND_IFINFO(ifp)->receivedra;
1432 		break;
1433 	case SIOCGIFINFO_IN6:
1434 		ndi->ndi = *ND_IFINFO(ifp);
1435 		break;
1436 	case SIOCSIFINFO_FLAGS:
1437 		ND_IFINFO(ifp)->flags = ndi->ndi.flags;
1438 		break;
1439 	case SIOCSNDFLUSH_IN6:	/* XXX: the ioctl name is confusing... */
1440 		/* flush default router list */
1441 		/*
1442 		 * xxx sumikawa: should not delete route if default
1443 		 * route equals to the top of default router list
1444 		 */
1445 		bzero(&any, sizeof(any));
1446 		defrouter_delreq(&any, 0);
1447 		defrouter_select();
1448 		/* xxx sumikawa: flush prefix list */
1449 		break;
1450 	case SIOCSPFXFLUSH_IN6:
1451 	    {
1452 		/* flush all the prefix advertised by routers */
1453 		struct nd_prefix *pr, *next;
1454 
1455 		mtx_lock(&nd6_mtx);
1456 		for (pr = nd_prefix.lh_first; pr; pr = next) {
1457 			struct in6_ifaddr *ia, *ia_next;
1458 
1459 			next = pr->ndpr_next;
1460 
1461 			if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1462 				continue; /* XXX */
1463 
1464 			/* do we really have to remove addresses as well? */
1465 			for (ia = in6_ifaddr; ia; ia = ia_next) {
1466 				/* ia might be removed.  keep the next ptr. */
1467 				ia_next = ia->ia_next;
1468 
1469 				if (!(ia->ia6_flags & IN6_IFF_AUTOCONF))
1470 					continue;
1471 
1472 				if (ia->ia6_ndpr == pr)
1473 					in6_purgeaddr(&ia->ia_ifa);
1474 			}
1475 			prelist_remove(pr);
1476 		}
1477 		mtx_unlock(&nd6_mtx);
1478 		break;
1479 	    }
1480 	case SIOCSRTRFLUSH_IN6:
1481 	    {
1482 		/* flush all the default routers */
1483 		struct nd_defrouter *dr, *next;
1484 
1485 		mtx_lock(&nd6_mtx);
1486 		if ((dr = TAILQ_FIRST(&nd_defrouter)) != NULL) {
1487 			/*
1488 			 * The first entry of the list may be stored in
1489 			 * the routing table, so we'll delete it later.
1490 			 */
1491 			for (dr = TAILQ_NEXT(dr, dr_entry); dr; dr = next) {
1492 				next = TAILQ_NEXT(dr, dr_entry);
1493 				defrtrlist_del(dr);
1494 			}
1495 			defrtrlist_del(TAILQ_FIRST(&nd_defrouter));
1496 		}
1497 		mtx_unlock(&nd6_mtx);
1498 		break;
1499 	    }
1500 	case SIOCGNBRINFO_IN6:
1501 	    {
1502 		struct llinfo_nd6 *ln;
1503 		struct in6_addr nb_addr = nbi->addr; /* make local for safety */
1504 
1505 		/*
1506 		 * XXX: KAME specific hack for scoped addresses
1507 		 *      XXXX: for other scopes than link-local?
1508 		 */
1509 		if (IN6_IS_ADDR_LINKLOCAL(&nbi->addr) ||
1510 		    IN6_IS_ADDR_MC_LINKLOCAL(&nbi->addr)) {
1511 			u_int16_t *idp = (u_int16_t *)&nb_addr.s6_addr[2];
1512 
1513 			if (*idp == 0)
1514 				*idp = htons(ifp->if_index);
1515 		}
1516 
1517 		mtx_lock(&nd6_mtx);
1518 		if ((rt = nd6_lookup(&nb_addr, 0, ifp)) == NULL) {
1519 			error = EINVAL;
1520 			mtx_unlock(&nd6_mtx);
1521 			break;
1522 		}
1523 		ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1524 		nbi->state = ln->ln_state;
1525 		nbi->asked = ln->ln_asked;
1526 		nbi->isrouter = ln->ln_router;
1527 		nbi->expire = ln->ln_expire;
1528 		mtx_unlock(&nd6_mtx);
1529 
1530 		break;
1531 	    }
1532 	case SIOCGDEFIFACE_IN6:	/* XXX: should be implemented as a sysctl? */
1533 		ndif->ifindex = nd6_defifindex;
1534 		break;
1535 	case SIOCSDEFIFACE_IN6:	/* XXX: should be implemented as a sysctl? */
1536 		return (nd6_setdefaultiface(ndif->ifindex));
1537 		break;
1538 	}
1539 	return (error);
1540 }
1541 
1542 /*
1543  * Create neighbor cache entry and cache link-layer address,
1544  * on reception of inbound ND6 packets. (RS/RA/NS/redirect)
1545  */
1546 struct rtentry *
1547 nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr,
1548 		 int lladdrlen,
1549 		 int type,	/* ICMP6 type */
1550 		 int code	/* type dependent information */)
1551 {
1552 	struct rtentry *rt = NULL;
1553 	struct llinfo_nd6 *ln = NULL;
1554 	int is_newentry;
1555 	struct sockaddr_dl *sdl = NULL;
1556 	int do_update;
1557 	int olladdr;
1558 	int llchange;
1559 	int newstate = 0;
1560 
1561 	if (!ifp)
1562 		panic("ifp == NULL in nd6_cache_lladdr");
1563 	if (!from)
1564 		panic("from == NULL in nd6_cache_lladdr");
1565 
1566 	/* nothing must be updated for unspecified address */
1567 	if (IN6_IS_ADDR_UNSPECIFIED(from))
1568 		return NULL;
1569 
1570 	/*
1571 	 * Validation about ifp->if_addrlen and lladdrlen must be done in
1572 	 * the caller.
1573 	 *
1574 	 * XXX If the link does not have link-layer adderss, what should
1575 	 * we do? (ifp->if_addrlen == 0)
1576 	 * Spec says nothing in sections for RA, RS and NA.  There's small
1577 	 * description on it in NS section (RFC 2461 7.2.3).
1578 	 */
1579 
1580 	rt = nd6_lookup(from, 0, ifp);
1581 	if (!rt) {
1582 #if 0
1583 		/* nothing must be done if there's no lladdr */
1584 		if (!lladdr || !lladdrlen)
1585 			return NULL;
1586 #endif
1587 
1588 		rt = nd6_lookup(from, 1, ifp);
1589 		is_newentry = 1;
1590 	} else {
1591 		/* do nothing if static ndp is set */
1592 		if (rt->rt_flags & RTF_STATIC)
1593 			return NULL;
1594 		is_newentry = 0;
1595 	}
1596 
1597 	if (!rt)
1598 		return NULL;
1599 	if ((rt->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) != RTF_LLINFO) {
1600 fail:
1601 		nd6_free(rt);
1602 		return NULL;
1603 	}
1604 	ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1605 	if (!ln)
1606 		goto fail;
1607 	if (!rt->rt_gateway)
1608 		goto fail;
1609 	if (rt->rt_gateway->sa_family != AF_LINK)
1610 		goto fail;
1611 	sdl = SDL(rt->rt_gateway);
1612 
1613 	olladdr = (sdl->sdl_alen) ? 1 : 0;
1614 	if (olladdr && lladdr) {
1615 		if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen))
1616 			llchange = 1;
1617 		else
1618 			llchange = 0;
1619 	} else
1620 		llchange = 0;
1621 
1622 	/*
1623 	 * newentry olladdr  lladdr  llchange	(*=record)
1624 	 *	0	n	n	--	(1)
1625 	 *	0	y	n	--	(2)
1626 	 *	0	n	y	--	(3) * STALE
1627 	 *	0	y	y	n	(4) *
1628 	 *	0	y	y	y	(5) * STALE
1629 	 *	1	--	n	--	(6)   NOSTATE(= PASSIVE)
1630 	 *	1	--	y	--	(7) * STALE
1631 	 */
1632 
1633 	if (lladdr) {		/* (3-5) and (7) */
1634 		/*
1635 		 * Record source link-layer address
1636 		 * XXX is it dependent to ifp->if_type?
1637 		 */
1638 		sdl->sdl_alen = ifp->if_addrlen;
1639 		bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen);
1640 	}
1641 
1642 	if (!is_newentry) {
1643 		if ((!olladdr && lladdr)		/* (3) */
1644 		 || (olladdr && lladdr && llchange)) {	/* (5) */
1645 			do_update = 1;
1646 			newstate = ND6_LLINFO_STALE;
1647 		} else					/* (1-2,4) */
1648 			do_update = 0;
1649 	} else {
1650 		do_update = 1;
1651 		if (!lladdr)				/* (6) */
1652 			newstate = ND6_LLINFO_NOSTATE;
1653 		else					/* (7) */
1654 			newstate = ND6_LLINFO_STALE;
1655 	}
1656 
1657 	if (do_update) {
1658 		/*
1659 		 * Update the state of the neighbor cache.
1660 		 */
1661 		ln->ln_state = newstate;
1662 
1663 		if (ln->ln_state == ND6_LLINFO_STALE) {
1664 			/*
1665 			 * XXX: since nd6_output() below will cause
1666 			 * state tansition to DELAY and reset the timer,
1667 			 * we must set the timer now, although it is actually
1668 			 * meaningless.
1669 			 */
1670 			ln->ln_expire = time_uptime + nd6_gctimer;
1671 
1672 			if (ln->ln_hold) {
1673 				/*
1674 				 * we assume ifp is not a p2p here, so just
1675 				 * set the 2nd argument as the 1st one.
1676 				 */
1677 				nd6_output(ifp, ifp, ln->ln_hold,
1678 					   (struct sockaddr_in6 *)rt_key(rt),
1679 					   rt);
1680 				ln->ln_hold = NULL;
1681 			}
1682 		} else if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
1683 			/* probe right away */
1684 			ln->ln_expire = time_uptime;
1685 		}
1686 	}
1687 
1688 	/*
1689 	 * ICMP6 type dependent behavior.
1690 	 *
1691 	 * NS: clear IsRouter if new entry
1692 	 * RS: clear IsRouter
1693 	 * RA: set IsRouter if there's lladdr
1694 	 * redir: clear IsRouter if new entry
1695 	 *
1696 	 * RA case, (1):
1697 	 * The spec says that we must set IsRouter in the following cases:
1698 	 * - If lladdr exist, set IsRouter.  This means (1-5).
1699 	 * - If it is old entry (!newentry), set IsRouter.  This means (7).
1700 	 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
1701 	 * A quetion arises for (1) case.  (1) case has no lladdr in the
1702 	 * neighbor cache, this is similar to (6).
1703 	 * This case is rare but we figured that we MUST NOT set IsRouter.
1704 	 *
1705 	 * newentry olladdr  lladdr  llchange	    NS  RS  RA	redir
1706 	 *							D R
1707 	 *	0	n	n	--	(1)	c   ?     s
1708 	 *	0	y	n	--	(2)	c   s     s
1709 	 *	0	n	y	--	(3)	c   s     s
1710 	 *	0	y	y	n	(4)	c   s     s
1711 	 *	0	y	y	y	(5)	c   s     s
1712 	 *	1	--	n	--	(6) c	c 	c s
1713 	 *	1	--	y	--	(7) c	c   s	c s
1714 	 *
1715 	 *					(c=clear s=set)
1716 	 */
1717 	switch (type & 0xff) {
1718 	case ND_NEIGHBOR_SOLICIT:
1719 		/*
1720 		 * New entry must have is_router flag cleared.
1721 		 */
1722 		if (is_newentry)	/* (6-7) */
1723 			ln->ln_router = 0;
1724 		break;
1725 	case ND_REDIRECT:
1726 		/*
1727 		 * If the icmp is a redirect to a better router, always set the
1728 		 * is_router flag. Otherwise, if the entry is newly created,
1729 		 * clear the flag. [RFC 2461, sec 8.3]
1730 		 */
1731 		if (code == ND_REDIRECT_ROUTER)
1732 			ln->ln_router = 1;
1733 		else if (is_newentry) /* (6-7) */
1734 			ln->ln_router = 0;
1735 		break;
1736 	case ND_ROUTER_SOLICIT:
1737 		/*
1738 		 * is_router flag must always be cleared.
1739 		 */
1740 		ln->ln_router = 0;
1741 		break;
1742 	case ND_ROUTER_ADVERT:
1743 		/*
1744 		 * Mark an entry with lladdr as a router.
1745 		 */
1746 		if ((!is_newentry && (olladdr || lladdr))	/* (2-5) */
1747 		 || (is_newentry && lladdr)) {			/* (7) */
1748 			ln->ln_router = 1;
1749 		}
1750 		break;
1751 	}
1752 
1753 	/*
1754 	 * When the link-layer address of a router changes, select the
1755 	 * best router again.  In particular, when the neighbor entry is newly
1756 	 * created, it might affect the selection policy.
1757 	 * Question: can we restrict the first condition to the "is_newentry"
1758 	 * case?
1759 	 * XXX: when we hear an RA from a new router with the link-layer
1760 	 * address option, defrouter_select() is called twice, since
1761 	 * defrtrlist_update called the function as well.  However, I believe
1762 	 * we can compromise the overhead, since it only happens the first
1763 	 * time.
1764 	 * XXX: although defrouter_select() should not have a bad effect
1765 	 * for those are not autoconfigured hosts, we explicitly avoid such
1766 	 * cases for safety.
1767 	 */
1768 	if (do_update && ln->ln_router && !ip6_forwarding && ip6_accept_rtadv)
1769 		defrouter_select();
1770 
1771 	return rt;
1772 }
1773 
1774 static void
1775 nd6_slowtimo(void *ignored_arg)
1776 {
1777 	struct nd_ifinfo *nd6if;
1778 	struct ifnet *ifp;
1779 
1780 	mtx_lock(&nd6_mtx);
1781 	callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
1782 			nd6_slowtimo, NULL);
1783 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1784 		if (ifp->if_afdata[AF_INET6] == NULL)
1785 			continue;
1786 		nd6if = ND_IFINFO(ifp);
1787 		if (nd6if->basereachable && /* already initialized */
1788 		    (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
1789 			/*
1790 			 * Since reachable time rarely changes by router
1791 			 * advertisements, we SHOULD insure that a new random
1792 			 * value gets recomputed at least once every few hours.
1793 			 * (RFC 2461, 6.3.4)
1794 			 */
1795 			nd6if->recalctm = nd6_recalc_reachtm_interval;
1796 			nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable);
1797 		}
1798 	}
1799 	mtx_unlock(&nd6_mtx);
1800 }
1801 
1802 #define gotoerr(e) { error = (e); goto bad;}
1803 
1804 int
1805 nd6_output(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
1806 	   struct sockaddr_in6 *dst, struct rtentry *rt)
1807 {
1808 	struct llinfo_nd6 *ln = NULL;
1809 	int error = 0;
1810 
1811 	if (IN6_IS_ADDR_MULTICAST(&dst->sin6_addr))
1812 		goto sendpkt;
1813 
1814 	if (nd6_need_cache(ifp) == 0)
1815 		goto sendpkt;
1816 
1817 	/*
1818 	 * next hop determination.  This routine is derived from ether_outpout.
1819 	 */
1820 	if (rt != NULL) {
1821 		if (!(rt->rt_flags & RTF_UP)) {
1822 			rt = rtlookup((struct sockaddr *)dst);
1823 			if (rt == NULL)
1824 				gotoerr(EHOSTUNREACH);
1825 			rt->rt_refcnt--;
1826 			if (rt->rt_ifp != ifp) {
1827 				/* XXX: loop care? */
1828 				return nd6_output(ifp, origifp, m, dst, rt);
1829 			}
1830 		}
1831 		if (rt->rt_flags & RTF_GATEWAY) {
1832 			struct sockaddr_in6 *gw6;
1833 
1834 			/*
1835 			 * We skip link-layer address resolution and NUD
1836 			 * if the gateway is not a neighbor from ND point
1837 			 * of view, regardless of the value of nd_ifinfo.flags.
1838 			 * The second condition is a bit tricky; we skip
1839 			 * if the gateway is our own address, which is
1840 			 * sometimes used to install a route to a p2p link.
1841 			 */
1842 			gw6 = (struct sockaddr_in6 *)rt->rt_gateway;
1843 			if (!nd6_is_addr_neighbor(gw6, ifp) ||
1844 			    in6ifa_ifpwithaddr(ifp, &gw6->sin6_addr)) {
1845 				/*
1846 				 * We allow this kind of tricky route only
1847 				 * when the outgoing interface is p2p.
1848 				 * XXX: we may need a more generic rule here.
1849 				 */
1850 				if (!(ifp->if_flags & IFF_POINTOPOINT))
1851 					gotoerr(EHOSTUNREACH);
1852 
1853 				goto sendpkt;
1854 			}
1855 
1856 			if (rt->rt_gwroute == NULL) {
1857 				rt->rt_gwroute = rtlookup(rt->rt_gateway);
1858 				if (rt->rt_gwroute == NULL)
1859 					gotoerr(EHOSTUNREACH);
1860 			} else if (!(rt->rt_gwroute->rt_flags & RTF_UP)) {
1861 				rtfree(rt->rt_gwroute);
1862 				rt->rt_gwroute = rtlookup(rt->rt_gateway);
1863 				if (rt->rt_gwroute == NULL)
1864 					gotoerr(EHOSTUNREACH);
1865 			}
1866 		}
1867 	}
1868 
1869 	/*
1870 	 * Address resolution or Neighbor Unreachability Detection
1871 	 * for the next hop.
1872 	 * At this point, the destination of the packet must be a unicast
1873 	 * or an anycast address(i.e. not a multicast).
1874 	 */
1875 
1876 	/* Look up the neighbor cache for the nexthop */
1877 	if (rt && (rt->rt_flags & RTF_LLINFO))
1878 		ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1879 	else {
1880 		/*
1881 		 * Since nd6_is_addr_neighbor() internally calls nd6_lookup(),
1882 		 * the condition below is not very efficient.  But we believe
1883 		 * it is tolerable, because this should be a rare case.
1884 		 */
1885 		if (nd6_is_addr_neighbor(dst, ifp) &&
1886 		    (rt = nd6_lookup(&dst->sin6_addr, 1, ifp)) != NULL)
1887 			ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1888 	}
1889 	if (!ln || !rt) {
1890 		if (!(ifp->if_flags & IFF_POINTOPOINT) &&
1891 		    !(ND_IFINFO(ifp)->flags & ND6_IFF_PERFORMNUD)) {
1892 			log(LOG_DEBUG,
1893 			    "nd6_output: can't allocate llinfo for %s "
1894 			    "(ln=%p, rt=%p)\n",
1895 			    ip6_sprintf(&dst->sin6_addr), ln, rt);
1896 			gotoerr(EIO);	/* XXX: good error? */
1897 		}
1898 
1899 		goto sendpkt;	/* send anyway */
1900 	}
1901 
1902 	/* We don't have to do link-layer address resolution on a p2p link. */
1903 	if ((ifp->if_flags & IFF_POINTOPOINT) &&
1904 	    ln->ln_state < ND6_LLINFO_REACHABLE) {
1905 		ln->ln_state = ND6_LLINFO_STALE;
1906 		ln->ln_expire = time_uptime + nd6_gctimer;
1907 	}
1908 
1909 	/*
1910 	 * The first time we send a packet to a neighbor whose entry is
1911 	 * STALE, we have to change the state to DELAY and a sets a timer to
1912 	 * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do
1913 	 * neighbor unreachability detection on expiration.
1914 	 * (RFC 2461 7.3.3)
1915 	 */
1916 	if (ln->ln_state == ND6_LLINFO_STALE) {
1917 		ln->ln_asked = 0;
1918 		ln->ln_state = ND6_LLINFO_DELAY;
1919 		ln->ln_expire = time_uptime + nd6_delay;
1920 	}
1921 
1922 	/*
1923 	 * If the neighbor cache entry has a state other than INCOMPLETE
1924 	 * (i.e. its link-layer address is already resolved), just
1925 	 * send the packet.
1926 	 */
1927 	if (ln->ln_state > ND6_LLINFO_INCOMPLETE)
1928 		goto sendpkt;
1929 
1930 	/*
1931 	 * There is a neighbor cache entry, but no ethernet address
1932 	 * response yet.  Replace the held mbuf (if any) with this
1933 	 * latest one.
1934 	 *
1935 	 * This code conforms to the rate-limiting rule described in Section
1936 	 * 7.2.2 of RFC 2461, because the timer is set correctly after sending
1937 	 * an NS below.
1938 	 */
1939 	if (ln->ln_state == ND6_LLINFO_NOSTATE)
1940 		ln->ln_state = ND6_LLINFO_INCOMPLETE;
1941 	if (ln->ln_hold)
1942 		m_freem(ln->ln_hold);
1943 	ln->ln_hold = m;
1944 	if (ln->ln_expire) {
1945 		if (ln->ln_asked < nd6_mmaxtries &&
1946 		    ln->ln_expire < time_uptime) {
1947 			ln->ln_asked++;
1948 			ln->ln_expire = time_uptime +
1949 				ND_IFINFO(ifp)->retrans / 1000;
1950 			nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0);
1951 		}
1952 	}
1953 	return (0);
1954 
1955 sendpkt:
1956 	if (ifp->if_flags & IFF_LOOPBACK)
1957 		error = ifp->if_output(origifp, m, (struct sockaddr *)dst, rt);
1958 	else
1959 		error = ifp->if_output(ifp, m, (struct sockaddr *)dst, rt);
1960 	return (error);
1961 
1962 bad:
1963 	m_freem(m);
1964 	return (error);
1965 }
1966 #undef gotoerr
1967 
1968 int
1969 nd6_need_cache(struct ifnet *ifp)
1970 {
1971 	/*
1972 	 * XXX: we currently do not make neighbor cache on any interface
1973 	 * other than Ethernet and GIF.
1974 	 *
1975 	 * RFC2893 says:
1976 	 * - unidirectional tunnels needs no ND
1977 	 */
1978 	switch (ifp->if_type) {
1979 	case IFT_ETHER:
1980 	case IFT_IEEE1394:
1981 #ifdef IFT_L2VLAN
1982 	case IFT_L2VLAN:
1983 #endif
1984 #ifdef IFT_IEEE80211
1985 	case IFT_IEEE80211:
1986 #endif
1987 #ifdef IFT_CARP
1988 	case IFT_CARP:
1989 #endif
1990 	case IFT_GIF:		/* XXX need more cases? */
1991 		return (1);
1992 	default:
1993 		return (0);
1994 	}
1995 }
1996 
1997 int
1998 nd6_storelladdr(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m,
1999 		struct sockaddr *dst, u_char *desten)
2000 {
2001 	struct sockaddr_dl *sdl;
2002 	struct rtentry *rt;
2003 
2004 
2005 	if (m->m_flags & M_MCAST) {
2006 		switch (ifp->if_type) {
2007 		case IFT_ETHER:
2008 #ifdef IFT_L2VLAN
2009 	case IFT_L2VLAN:
2010 #endif
2011 #ifdef IFT_IEEE80211
2012 		case IFT_IEEE80211:
2013 #endif
2014 			ETHER_MAP_IPV6_MULTICAST(&SIN6(dst)->sin6_addr,
2015 						 desten);
2016 			return (1);
2017 		case IFT_IEEE1394:
2018 			bcopy(ifp->if_broadcastaddr, desten, ifp->if_addrlen);
2019 			return (1);
2020 		default:
2021 			m_freem(m);
2022 			return (0);
2023 		}
2024 	}
2025 	if (rt0 == NULL) {
2026 		/* this could happen, if we could not allocate memory */
2027 		m_freem(m);
2028 		return (0);
2029 	}
2030 	if (rt_llroute(dst, rt0, &rt) != 0) {
2031 		m_freem(m);
2032 		return (0);
2033 	}
2034 	if (rt->rt_gateway->sa_family != AF_LINK) {
2035 		kprintf("nd6_storelladdr: something odd happens\n");
2036 		m_freem(m);
2037 		return (0);
2038 	}
2039 	sdl = SDL(rt->rt_gateway);
2040 	if (sdl->sdl_alen == 0) {
2041 		/* this should be impossible, but we bark here for debugging */
2042 		kprintf("nd6_storelladdr: sdl_alen == 0\n");
2043 		m_freem(m);
2044 		return (0);
2045 	}
2046 
2047 	bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
2048 	return (1);
2049 }
2050 
2051 static int nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS);
2052 static int nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS);
2053 #ifdef SYSCTL_DECL
2054 SYSCTL_DECL(_net_inet6_icmp6);
2055 #endif
2056 SYSCTL_NODE(_net_inet6_icmp6, ICMPV6CTL_ND6_DRLIST, nd6_drlist,
2057 	CTLFLAG_RD, nd6_sysctl_drlist, "List default routers");
2058 SYSCTL_NODE(_net_inet6_icmp6, ICMPV6CTL_ND6_PRLIST, nd6_prlist,
2059 	CTLFLAG_RD, nd6_sysctl_prlist, "List prefixes");
2060 
2061 static int
2062 nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS)
2063 {
2064 	int error;
2065 	char buf[1024];
2066 	struct in6_defrouter *d, *de;
2067 	struct nd_defrouter *dr;
2068 
2069 	if (req->newptr)
2070 		return EPERM;
2071 	error = 0;
2072 
2073 	for (dr = TAILQ_FIRST(&nd_defrouter);
2074 	     dr;
2075 	     dr = TAILQ_NEXT(dr, dr_entry)) {
2076 		d = (struct in6_defrouter *)buf;
2077 		de = (struct in6_defrouter *)(buf + sizeof(buf));
2078 
2079 		if (d + 1 <= de) {
2080 			bzero(d, sizeof(*d));
2081 			d->rtaddr.sin6_family = AF_INET6;
2082 			d->rtaddr.sin6_len = sizeof(d->rtaddr);
2083 			if (in6_recoverscope(&d->rtaddr, &dr->rtaddr,
2084 			    dr->ifp) != 0)
2085 				log(LOG_ERR,
2086 				    "scope error in "
2087 				    "default router list (%s)\n",
2088 				    ip6_sprintf(&dr->rtaddr));
2089 			d->flags = dr->flags;
2090 			d->rtlifetime = dr->rtlifetime;
2091 			d->expire = dr->expire;
2092 			d->if_index = dr->ifp->if_index;
2093 		} else
2094 			panic("buffer too short");
2095 
2096 		error = SYSCTL_OUT(req, buf, sizeof(*d));
2097 		if (error)
2098 			break;
2099 	}
2100 	return error;
2101 }
2102 
2103 static int
2104 nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS)
2105 {
2106 	int error;
2107 	char buf[1024];
2108 	struct in6_prefix *p, *pe;
2109 	struct nd_prefix *pr;
2110 
2111 	if (req->newptr)
2112 		return EPERM;
2113 	error = 0;
2114 
2115 	for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
2116 		u_short advrtrs;
2117 		size_t advance;
2118 		struct sockaddr_in6 *sin6, *s6;
2119 		struct nd_pfxrouter *pfr;
2120 
2121 		p = (struct in6_prefix *)buf;
2122 		pe = (struct in6_prefix *)(buf + sizeof(buf));
2123 
2124 		if (p + 1 <= pe) {
2125 			bzero(p, sizeof(*p));
2126 			sin6 = (struct sockaddr_in6 *)(p + 1);
2127 
2128 			p->prefix = pr->ndpr_prefix;
2129 			if (in6_recoverscope(&p->prefix,
2130 			    &p->prefix.sin6_addr, pr->ndpr_ifp) != 0)
2131 				log(LOG_ERR,
2132 				    "scope error in prefix list (%s)\n",
2133 				    ip6_sprintf(&p->prefix.sin6_addr));
2134 			p->raflags = pr->ndpr_raf;
2135 			p->prefixlen = pr->ndpr_plen;
2136 			p->vltime = pr->ndpr_vltime;
2137 			p->pltime = pr->ndpr_pltime;
2138 			p->if_index = pr->ndpr_ifp->if_index;
2139 			p->expire = pr->ndpr_expire;
2140 			p->refcnt = pr->ndpr_refcnt;
2141 			p->flags = pr->ndpr_stateflags;
2142 			p->origin = PR_ORIG_RA;
2143 			advrtrs = 0;
2144 			for (pfr = pr->ndpr_advrtrs.lh_first;
2145 			     pfr;
2146 			     pfr = pfr->pfr_next) {
2147 				if ((void *)&sin6[advrtrs + 1] >
2148 				    (void *)pe) {
2149 					advrtrs++;
2150 					continue;
2151 				}
2152 				s6 = &sin6[advrtrs];
2153 				bzero(s6, sizeof(*s6));
2154 				s6->sin6_family = AF_INET6;
2155 				s6->sin6_len = sizeof(*sin6);
2156 				if (in6_recoverscope(s6, &pfr->router->rtaddr,
2157 						     pfr->router->ifp) != 0)
2158 					log(LOG_ERR,
2159 					    "scope error in "
2160 					    "prefix list (%s)\n",
2161 					    ip6_sprintf(&pfr->router->rtaddr));
2162 				advrtrs++;
2163 			}
2164 			p->advrtrs = advrtrs;
2165 		} else
2166 			panic("buffer too short");
2167 
2168 		advance = sizeof(*p) + sizeof(*sin6) * advrtrs;
2169 		error = SYSCTL_OUT(req, buf, advance);
2170 		if (error)
2171 			break;
2172 	}
2173 	return error;
2174 }
2175