xref: /dragonfly/sys/netinet6/nd6.c (revision 606a6e92)
1 /*	$FreeBSD: src/sys/netinet6/nd6.c,v 1.2.2.15 2003/05/06 06:46:58 suz Exp $	*/
2 /*	$DragonFly: src/sys/netinet6/nd6.c,v 1.13 2004/12/30 02:26:12 hsu Exp $	*/
3 /*	$KAME: nd6.c,v 1.144 2001/05/24 07:44:00 itojun Exp $	*/
4 
5 /*
6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the project nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 /*
35  * XXX
36  * KAME 970409 note:
37  * BSD/OS version heavily modifies this code, related to llinfo.
38  * Since we don't have BSD/OS version of net/route.c in our hand,
39  * I left the code mostly as it was in 970310.  -- itojun
40  */
41 
42 #include "opt_inet.h"
43 #include "opt_inet6.h"
44 
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/callout.h>
48 #include <sys/malloc.h>
49 #include <sys/mbuf.h>
50 #include <sys/socket.h>
51 #include <sys/sockio.h>
52 #include <sys/time.h>
53 #include <sys/kernel.h>
54 #include <sys/protosw.h>
55 #include <sys/errno.h>
56 #include <sys/syslog.h>
57 #include <sys/queue.h>
58 #include <sys/sysctl.h>
59 
60 #include <net/if.h>
61 #include <net/if_dl.h>
62 #include <net/if_types.h>
63 #include <net/if_atm.h>
64 #include <net/route.h>
65 
66 #include <netinet/in.h>
67 #include <netinet/if_ether.h>
68 #include <netinet/if_fddi.h>
69 #include <netinet6/in6_var.h>
70 #include <netinet/ip6.h>
71 #include <netinet6/ip6_var.h>
72 #include <netinet6/nd6.h>
73 #include <netinet6/in6_prefix.h>
74 #include <netinet/icmp6.h>
75 
76 #include "use_loop.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 static size_t nd_ifinfo_indexlim = 8;
110 struct nd_ifinfo *nd_ifinfo = NULL;
111 struct nd_drhead nd_defrouter;
112 struct nd_prhead nd_prefix = { 0 };
113 
114 int nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL;
115 static struct sockaddr_in6 all1_sa;
116 
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 void
152 nd6_ifattach(struct ifnet *ifp)
153 {
154 
155 	/*
156 	 * We have some arrays that should be indexed by if_index.
157 	 * since if_index will grow dynamically, they should grow too.
158 	 */
159 	if (nd_ifinfo == NULL || if_index >= nd_ifinfo_indexlim) {
160 		size_t n;
161 		caddr_t q;
162 
163 		while (if_index >= nd_ifinfo_indexlim)
164 			nd_ifinfo_indexlim <<= 1;
165 
166 		/* grow nd_ifinfo */
167 		n = nd_ifinfo_indexlim * sizeof(struct nd_ifinfo);
168 		q = (caddr_t)malloc(n, M_IP6NDP, M_WAITOK);
169 		bzero(q, n);
170 		if (nd_ifinfo) {
171 			bcopy((caddr_t)nd_ifinfo, q, n/2);
172 			free((caddr_t)nd_ifinfo, M_IP6NDP);
173 		}
174 		nd_ifinfo = (struct nd_ifinfo *)q;
175 	}
176 
177 #define ND nd_ifinfo[ifp->if_index]
178 
179 	/*
180 	 * Don't initialize if called twice.
181 	 * XXX: to detect this, we should choose a member that is never set
182 	 * before initialization of the ND structure itself.  We formaly used
183 	 * the linkmtu member, which was not suitable because it could be
184 	 * initialized via "ifconfig mtu".
185 	 */
186 	if (ND.basereachable)
187 		return;
188 
189 	ND.linkmtu = ifindex2ifnet[ifp->if_index]->if_mtu;
190 	ND.chlim = IPV6_DEFHLIM;
191 	ND.basereachable = REACHABLE_TIME;
192 	ND.reachable = ND_COMPUTE_RTIME(ND.basereachable);
193 	ND.retrans = RETRANS_TIMER;
194 	ND.receivedra = 0;
195 	/*
196 	 * Note that the default value of ip6_accept_rtadv is 0, which means
197 	 * we won't accept RAs by default even if we set ND6_IFF_ACCEPT_RTADV
198 	 * here.
199 	 */
200 	ND.flags = (ND6_IFF_PERFORMNUD | ND6_IFF_ACCEPT_RTADV);
201 	nd6_setmtu(ifp);
202 #undef ND
203 }
204 
205 /*
206  * Reset ND level link MTU. This function is called when the physical MTU
207  * changes, which means we might have to adjust the ND level MTU.
208  */
209 void
210 nd6_setmtu(struct ifnet *ifp)
211 {
212 	struct nd_ifinfo *ndi = &nd_ifinfo[ifp->if_index];
213 	u_long oldmaxmtu = ndi->maxmtu;
214 	u_long oldlinkmtu = ndi->linkmtu;
215 
216 	switch (ifp->if_type) {
217 	case IFT_ARCNET:	/* XXX MTU handling needs more work */
218 		ndi->maxmtu = MIN(60480, ifp->if_mtu);
219 		break;
220 	case IFT_ETHER:
221 		ndi->maxmtu = MIN(ETHERMTU, ifp->if_mtu);
222 		break;
223 	case IFT_FDDI:
224 		ndi->maxmtu = MIN(FDDIIPMTU, ifp->if_mtu);
225 		break;
226 	case IFT_ATM:
227 		ndi->maxmtu = MIN(ATMMTU, ifp->if_mtu);
228 		break;
229 	case IFT_IEEE1394:	/* XXX should be IEEE1394MTU(1500) */
230 		ndi->maxmtu = MIN(ETHERMTU, ifp->if_mtu);
231 		break;
232 #ifdef IFT_IEEE80211
233 	case IFT_IEEE80211:	/* XXX should be IEEE80211MTU(1500) */
234 		ndi->maxmtu = MIN(ETHERMTU, ifp->if_mtu);
235 		break;
236 #endif
237 	default:
238 		ndi->maxmtu = ifp->if_mtu;
239 		break;
240 	}
241 
242 	if (oldmaxmtu != ndi->maxmtu) {
243 		/*
244 		 * If the ND level MTU is not set yet, or if the maxmtu
245 		 * is reset to a smaller value than the ND level MTU,
246 		 * also reset the ND level MTU.
247 		 */
248 		if (ndi->linkmtu == 0 ||
249 		    ndi->maxmtu < ndi->linkmtu) {
250 			ndi->linkmtu = ndi->maxmtu;
251 			/* also adjust in6_maxmtu if necessary. */
252 			if (oldlinkmtu == 0) {
253 				/*
254 				 * XXX: the case analysis is grotty, but
255 				 * it is not efficient to call in6_setmaxmtu()
256 				 * here when we are during the initialization
257 				 * procedure.
258 				 */
259 				if (in6_maxmtu < ndi->linkmtu)
260 					in6_maxmtu = ndi->linkmtu;
261 			} else
262 				in6_setmaxmtu();
263 		}
264 	}
265 #undef MIN
266 }
267 
268 void
269 nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts)
270 {
271 	bzero(ndopts, sizeof(*ndopts));
272 	ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
273 	ndopts->nd_opts_last
274 		= (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len);
275 
276 	if (icmp6len == 0) {
277 		ndopts->nd_opts_done = 1;
278 		ndopts->nd_opts_search = NULL;
279 	}
280 }
281 
282 /*
283  * Take one ND option.
284  */
285 struct nd_opt_hdr *
286 nd6_option(union nd_opts *ndopts)
287 {
288 	struct nd_opt_hdr *nd_opt;
289 	int olen;
290 
291 	if (!ndopts)
292 		panic("ndopts == NULL in nd6_option");
293 	if (!ndopts->nd_opts_last)
294 		panic("uninitialized ndopts in nd6_option");
295 	if (!ndopts->nd_opts_search)
296 		return NULL;
297 	if (ndopts->nd_opts_done)
298 		return NULL;
299 
300 	nd_opt = ndopts->nd_opts_search;
301 
302 	/* make sure nd_opt_len is inside the buffer */
303 	if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) {
304 		bzero(ndopts, sizeof(*ndopts));
305 		return NULL;
306 	}
307 
308 	olen = nd_opt->nd_opt_len << 3;
309 	if (olen == 0) {
310 		/*
311 		 * Message validation requires that all included
312 		 * options have a length that is greater than zero.
313 		 */
314 		bzero(ndopts, sizeof(*ndopts));
315 		return NULL;
316 	}
317 
318 	ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen);
319 	if (ndopts->nd_opts_search > ndopts->nd_opts_last) {
320 		/* option overruns the end of buffer, invalid */
321 		bzero(ndopts, sizeof(*ndopts));
322 		return NULL;
323 	} else if (ndopts->nd_opts_search == ndopts->nd_opts_last) {
324 		/* reached the end of options chain */
325 		ndopts->nd_opts_done = 1;
326 		ndopts->nd_opts_search = NULL;
327 	}
328 	return nd_opt;
329 }
330 
331 /*
332  * Parse multiple ND options.
333  * This function is much easier to use, for ND routines that do not need
334  * multiple options of the same type.
335  */
336 int
337 nd6_options(union nd_opts *ndopts)
338 {
339 	struct nd_opt_hdr *nd_opt;
340 	int i = 0;
341 
342 	if (!ndopts)
343 		panic("ndopts == NULL in nd6_options");
344 	if (!ndopts->nd_opts_last)
345 		panic("uninitialized ndopts in nd6_options");
346 	if (!ndopts->nd_opts_search)
347 		return 0;
348 
349 	while (1) {
350 		nd_opt = nd6_option(ndopts);
351 		if (!nd_opt && !ndopts->nd_opts_last) {
352 			/*
353 			 * Message validation requires that all included
354 			 * options have a length that is greater than zero.
355 			 */
356 			icmp6stat.icp6s_nd_badopt++;
357 			bzero(ndopts, sizeof(*ndopts));
358 			return -1;
359 		}
360 
361 		if (!nd_opt)
362 			goto skip1;
363 
364 		switch (nd_opt->nd_opt_type) {
365 		case ND_OPT_SOURCE_LINKADDR:
366 		case ND_OPT_TARGET_LINKADDR:
367 		case ND_OPT_MTU:
368 		case ND_OPT_REDIRECTED_HEADER:
369 			if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
370 				nd6log((LOG_INFO,
371 				    "duplicated ND6 option found (type=%d)\n",
372 				    nd_opt->nd_opt_type));
373 				/* XXX bark? */
374 			} else {
375 				ndopts->nd_opt_array[nd_opt->nd_opt_type]
376 					= nd_opt;
377 			}
378 			break;
379 		case ND_OPT_PREFIX_INFORMATION:
380 			if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
381 				ndopts->nd_opt_array[nd_opt->nd_opt_type]
382 					= nd_opt;
383 			}
384 			ndopts->nd_opts_pi_end =
385 				(struct nd_opt_prefix_info *)nd_opt;
386 			break;
387 		default:
388 			/*
389 			 * Unknown options must be silently ignored,
390 			 * to accomodate future extension to the protocol.
391 			 */
392 			nd6log((LOG_DEBUG,
393 			    "nd6_options: unsupported option %d - "
394 			    "option ignored\n", nd_opt->nd_opt_type));
395 		}
396 
397 skip1:
398 		i++;
399 		if (i > nd6_maxndopt) {
400 			icmp6stat.icp6s_nd_toomanyopt++;
401 			nd6log((LOG_INFO, "too many loop in nd opt\n"));
402 			break;
403 		}
404 
405 		if (ndopts->nd_opts_done)
406 			break;
407 	}
408 
409 	return 0;
410 }
411 
412 /*
413  * ND6 timer routine to expire default route list and prefix list
414  */
415 void
416 nd6_timer(void *ignored_arg)
417 {
418 	int s;
419 	struct llinfo_nd6 *ln;
420 	struct nd_defrouter *dr;
421 	struct nd_prefix *pr;
422 	struct ifnet *ifp;
423 	struct in6_ifaddr *ia6, *nia6;
424 	struct in6_addrlifetime *lt6;
425 
426 	s = splnet();
427 	callout_reset(&nd6_timer_ch, nd6_prune * hz,
428 		      nd6_timer, NULL);
429 
430 	ln = llinfo_nd6.ln_next;
431 	while (ln && ln != &llinfo_nd6) {
432 		struct rtentry *rt;
433 		struct sockaddr_in6 *dst;
434 		struct llinfo_nd6 *next = ln->ln_next;
435 		/* XXX: used for the DELAY case only: */
436 		struct nd_ifinfo *ndi = NULL;
437 
438 		if ((rt = ln->ln_rt) == NULL) {
439 			ln = next;
440 			continue;
441 		}
442 		if ((ifp = rt->rt_ifp) == NULL) {
443 			ln = next;
444 			continue;
445 		}
446 		ndi = &nd_ifinfo[ifp->if_index];
447 		dst = (struct sockaddr_in6 *)rt_key(rt);
448 
449 		if (ln->ln_expire > time_second) {
450 			ln = next;
451 			continue;
452 		}
453 
454 		/* sanity check */
455 		if (!rt)
456 			panic("rt=0 in nd6_timer(ln=%p)", ln);
457 		if (rt->rt_llinfo && (struct llinfo_nd6 *)rt->rt_llinfo != ln)
458 			panic("rt_llinfo(%p) is not equal to ln(%p)",
459 			      rt->rt_llinfo, ln);
460 		if (!dst)
461 			panic("dst=0 in nd6_timer(ln=%p)", ln);
462 
463 		switch (ln->ln_state) {
464 		case ND6_LLINFO_INCOMPLETE:
465 			if (ln->ln_asked < nd6_mmaxtries) {
466 				ln->ln_asked++;
467 				ln->ln_expire = time_second +
468 					nd_ifinfo[ifp->if_index].retrans / 1000;
469 				nd6_ns_output(ifp, NULL, &dst->sin6_addr,
470 					ln, 0);
471 			} else {
472 				struct mbuf *m = ln->ln_hold;
473 				if (m) {
474 					if (rt->rt_ifp) {
475 						/*
476 						 * Fake rcvif to make ICMP error
477 						 * more helpful in diagnosing
478 						 * for the receiver.
479 						 * XXX: should we consider
480 						 * older rcvif?
481 						 */
482 						m->m_pkthdr.rcvif = rt->rt_ifp;
483 					}
484 					icmp6_error(m, ICMP6_DST_UNREACH,
485 						    ICMP6_DST_UNREACH_ADDR, 0);
486 					ln->ln_hold = NULL;
487 				}
488 				next = nd6_free(rt);
489 			}
490 			break;
491 		case ND6_LLINFO_REACHABLE:
492 			if (ln->ln_expire) {
493 				ln->ln_state = ND6_LLINFO_STALE;
494 				ln->ln_expire = time_second + nd6_gctimer;
495 			}
496 			break;
497 
498 		case ND6_LLINFO_STALE:
499 			/* Garbage Collection(RFC 2461 5.3) */
500 			if (ln->ln_expire)
501 				next = nd6_free(rt);
502 			break;
503 
504 		case ND6_LLINFO_DELAY:
505 			if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) {
506 				/* We need NUD */
507 				ln->ln_asked = 1;
508 				ln->ln_state = ND6_LLINFO_PROBE;
509 				ln->ln_expire = time_second +
510 					ndi->retrans / 1000;
511 				nd6_ns_output(ifp, &dst->sin6_addr,
512 					      &dst->sin6_addr,
513 					      ln, 0);
514 			} else {
515 				ln->ln_state = ND6_LLINFO_STALE; /* XXX */
516 				ln->ln_expire = time_second + nd6_gctimer;
517 			}
518 			break;
519 		case ND6_LLINFO_PROBE:
520 			if (ln->ln_asked < nd6_umaxtries) {
521 				ln->ln_asked++;
522 				ln->ln_expire = time_second +
523 					nd_ifinfo[ifp->if_index].retrans / 1000;
524 				nd6_ns_output(ifp, &dst->sin6_addr,
525 					       &dst->sin6_addr, ln, 0);
526 			} else {
527 				next = nd6_free(rt);
528 			}
529 			break;
530 		}
531 		ln = next;
532 	}
533 
534 	/* expire default router list */
535 	dr = TAILQ_FIRST(&nd_defrouter);
536 	while (dr) {
537 		if (dr->expire && dr->expire < time_second) {
538 			struct nd_defrouter *t;
539 			t = TAILQ_NEXT(dr, dr_entry);
540 			defrtrlist_del(dr);
541 			dr = t;
542 		} else {
543 			dr = TAILQ_NEXT(dr, dr_entry);
544 		}
545 	}
546 
547 	/*
548 	 * expire interface addresses.
549 	 * in the past the loop was inside prefix expiry processing.
550 	 * However, from a stricter speci-confrmance standpoint, we should
551 	 * rather separate address lifetimes and prefix lifetimes.
552 	 */
553   addrloop:
554 	for (ia6 = in6_ifaddr; ia6; ia6 = nia6) {
555 		nia6 = ia6->ia_next;
556 		/* check address lifetime */
557 		lt6 = &ia6->ia6_lifetime;
558 		if (IFA6_IS_INVALID(ia6)) {
559 			int regen = 0;
560 
561 			/*
562 			 * If the expiring address is temporary, try
563 			 * regenerating a new one.  This would be useful when
564 			 * we suspended a laptop PC, then turned it on after a
565 			 * period that could invalidate all temporary
566 			 * addresses.  Although we may have to restart the
567 			 * loop (see below), it must be after purging the
568 			 * address.  Otherwise, we'd see an infinite loop of
569 			 * regeneration.
570 			 */
571 			if (ip6_use_tempaddr &&
572 			    (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
573 				if (regen_tmpaddr(ia6) == 0)
574 					regen = 1;
575 			}
576 
577 			in6_purgeaddr(&ia6->ia_ifa);
578 
579 			if (regen)
580 				goto addrloop; /* XXX: see below */
581 		}
582 		if (IFA6_IS_DEPRECATED(ia6)) {
583 			int oldflags = ia6->ia6_flags;
584 
585 			ia6->ia6_flags |= IN6_IFF_DEPRECATED;
586 
587 			/*
588 			 * If a temporary address has just become deprecated,
589 			 * regenerate a new one if possible.
590 			 */
591 			if (ip6_use_tempaddr &&
592 			    (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
593 			    (oldflags & IN6_IFF_DEPRECATED) == 0) {
594 
595 				if (regen_tmpaddr(ia6) == 0) {
596 					/*
597 					 * A new temporary address is
598 					 * generated.
599 					 * XXX: this means the address chain
600 					 * has changed while we are still in
601 					 * the loop.  Although the change
602 					 * would not cause disaster (because
603 					 * it's not a deletion, but an
604 					 * addition,) we'd rather restart the
605 					 * loop just for safety.  Or does this
606 					 * significantly reduce performance??
607 					 */
608 					goto addrloop;
609 				}
610 			}
611 		} else {
612 			/*
613 			 * A new RA might have made a deprecated address
614 			 * preferred.
615 			 */
616 			ia6->ia6_flags &= ~IN6_IFF_DEPRECATED;
617 		}
618 	}
619 
620 	/* expire prefix list */
621 	pr = nd_prefix.lh_first;
622 	while (pr) {
623 		/*
624 		 * check prefix lifetime.
625 		 * since pltime is just for autoconf, pltime processing for
626 		 * prefix is not necessary.
627 		 */
628 		if (pr->ndpr_expire && pr->ndpr_expire < time_second) {
629 			struct nd_prefix *t;
630 			t = pr->ndpr_next;
631 
632 			/*
633 			 * address expiration and prefix expiration are
634 			 * separate.  NEVER perform in6_purgeaddr here.
635 			 */
636 
637 			prelist_remove(pr);
638 			pr = t;
639 		} else
640 			pr = pr->ndpr_next;
641 	}
642 	splx(s);
643 }
644 
645 static int
646 regen_tmpaddr(struct in6_ifaddr *ia6) /* deprecated/invalidated temporary
647 					 address */
648 {
649 	struct ifaddr *ifa;
650 	struct ifnet *ifp;
651 	struct in6_ifaddr *public_ifa6 = NULL;
652 
653 	ifp = ia6->ia_ifa.ifa_ifp;
654 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_list) {
655 		struct in6_ifaddr *it6;
656 
657 		if (ifa->ifa_addr->sa_family != AF_INET6)
658 			continue;
659 
660 		it6 = (struct in6_ifaddr *)ifa;
661 
662 		/* ignore no autoconf addresses. */
663 		if ((it6->ia6_flags & IN6_IFF_AUTOCONF) == 0)
664 			continue;
665 
666 		/* ignore autoconf addresses with different prefixes. */
667 		if (it6->ia6_ndpr == NULL || it6->ia6_ndpr != ia6->ia6_ndpr)
668 			continue;
669 
670 		/*
671 		 * Now we are looking at an autoconf address with the same
672 		 * prefix as ours.  If the address is temporary and is still
673 		 * preferred, do not create another one.  It would be rare, but
674 		 * could happen, for example, when we resume a laptop PC after
675 		 * a long period.
676 		 */
677 		if ((it6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
678 		    !IFA6_IS_DEPRECATED(it6)) {
679 			public_ifa6 = NULL;
680 			break;
681 		}
682 
683 		/*
684 		 * This is a public autoconf address that has the same prefix
685 		 * as ours.  If it is preferred, keep it.  We can't break the
686 		 * loop here, because there may be a still-preferred temporary
687 		 * address with the prefix.
688 		 */
689 		if (!IFA6_IS_DEPRECATED(it6))
690 		    public_ifa6 = it6;
691 	}
692 
693 	if (public_ifa6 != NULL) {
694 		int e;
695 
696 		if ((e = in6_tmpifadd(public_ifa6, 0)) != 0) {
697 			log(LOG_NOTICE, "regen_tmpaddr: failed to create a new"
698 			    " tmp addr,errno=%d\n", e);
699 			return(-1);
700 		}
701 		return(0);
702 	}
703 
704 	return(-1);
705 }
706 
707 /*
708  * Nuke neighbor cache/prefix/default router management table, right before
709  * ifp goes away.
710  */
711 void
712 nd6_purge(struct ifnet *ifp)
713 {
714 	struct llinfo_nd6 *ln, *nln;
715 	struct nd_defrouter *dr, *ndr, drany;
716 	struct nd_prefix *pr, *npr;
717 
718 	/* Nuke default router list entries toward ifp */
719 	if ((dr = TAILQ_FIRST(&nd_defrouter)) != NULL) {
720 		/*
721 		 * The first entry of the list may be stored in
722 		 * the routing table, so we'll delete it later.
723 		 */
724 		for (dr = TAILQ_NEXT(dr, dr_entry); dr; dr = ndr) {
725 			ndr = TAILQ_NEXT(dr, dr_entry);
726 			if (dr->ifp == ifp)
727 				defrtrlist_del(dr);
728 		}
729 		dr = TAILQ_FIRST(&nd_defrouter);
730 		if (dr->ifp == ifp)
731 			defrtrlist_del(dr);
732 	}
733 
734 	/* Nuke prefix list entries toward ifp */
735 	for (pr = nd_prefix.lh_first; pr; pr = npr) {
736 		npr = pr->ndpr_next;
737 		if (pr->ndpr_ifp == ifp) {
738 			/*
739 			 * Previously, pr->ndpr_addr is removed as well,
740 			 * but I strongly believe we don't have to do it.
741 			 * nd6_purge() is only called from in6_ifdetach(),
742 			 * which removes all the associated interface addresses
743 			 * by itself.
744 			 * (jinmei@kame.net 20010129)
745 			 */
746 			prelist_remove(pr);
747 		}
748 	}
749 
750 	/* cancel default outgoing interface setting */
751 	if (nd6_defifindex == ifp->if_index)
752 		nd6_setdefaultiface(0);
753 
754 	if (!ip6_forwarding && ip6_accept_rtadv) { /* XXX: too restrictive? */
755 		/* refresh default router list */
756 		bzero(&drany, sizeof(drany));
757 		defrouter_delreq(&drany, 0);
758 		defrouter_select();
759 	}
760 
761 	/*
762 	 * Nuke neighbor cache entries for the ifp.
763 	 * Note that rt->rt_ifp may not be the same as ifp,
764 	 * due to KAME goto ours hack.  See RTM_RESOLVE case in
765 	 * nd6_rtrequest(), and ip6_input().
766 	 */
767 	ln = llinfo_nd6.ln_next;
768 	while (ln && ln != &llinfo_nd6) {
769 		struct rtentry *rt;
770 		struct sockaddr_dl *sdl;
771 
772 		nln = ln->ln_next;
773 		rt = ln->ln_rt;
774 		if (rt && rt->rt_gateway &&
775 		    rt->rt_gateway->sa_family == AF_LINK) {
776 			sdl = (struct sockaddr_dl *)rt->rt_gateway;
777 			if (sdl->sdl_index == ifp->if_index)
778 				nln = nd6_free(rt);
779 		}
780 		ln = nln;
781 	}
782 }
783 
784 struct rtentry *
785 nd6_lookup(struct in6_addr *addr6, int create, struct ifnet *ifp)
786 {
787 	struct rtentry *rt;
788 	struct sockaddr_in6 sin6;
789 
790 	bzero(&sin6, sizeof(sin6));
791 	sin6.sin6_len = sizeof(struct sockaddr_in6);
792 	sin6.sin6_family = AF_INET6;
793 	sin6.sin6_addr = *addr6;
794 #ifdef SCOPEDROUTING
795 	sin6.sin6_scope_id = in6_addr2scopeid(ifp, addr6);
796 #endif
797 	rt = rtlookup((struct sockaddr *)&sin6, create, 0UL);
798 	if (rt && !(rt->rt_flags & RTF_LLINFO)) {
799 		/*
800 		 * This is the case for the default route.
801 		 * If we want to create a neighbor cache for the address, we
802 		 * should free the route for the destination and allocate an
803 		 * interface route.
804 		 */
805 		if (create) {
806 			--rt->rt_refcnt;
807 			rt = NULL;
808 		}
809 	}
810 	if (!rt) {
811 		if (create && ifp) {
812 			int e;
813 
814 			/*
815 			 * If no route is available and create is set,
816 			 * we allocate a host route for the destination
817 			 * and treat it like an interface route.
818 			 * This hack is necessary for a neighbor which can't
819 			 * be covered by our own prefix.
820 			 */
821 			struct ifaddr *ifa =
822 				ifaof_ifpforaddr((struct sockaddr *)&sin6, ifp);
823 			if (ifa == NULL)
824 				return(NULL);
825 
826 			/*
827 			 * Create a new route.  RTF_LLINFO is necessary
828 			 * to create a Neighbor Cache entry for the
829 			 * destination in nd6_rtrequest which will be
830 			 * called in rtrequest via ifa->ifa_rtrequest.
831 			 */
832 			if ((e = rtrequest(RTM_ADD, (struct sockaddr *)&sin6,
833 					   ifa->ifa_addr,
834 					   (struct sockaddr *)&all1_sa,
835 					   (ifa->ifa_flags |
836 					    RTF_HOST | RTF_LLINFO) &
837 					   ~RTF_CLONING,
838 					   &rt)) != 0)
839 				log(LOG_ERR,
840 				    "nd6_lookup: failed to add route for a "
841 				    "neighbor(%s), errno=%d\n",
842 				    ip6_sprintf(addr6), e);
843 			if (rt == NULL)
844 				return(NULL);
845 			if (rt->rt_llinfo) {
846 				struct llinfo_nd6 *ln =
847 					(struct llinfo_nd6 *)rt->rt_llinfo;
848 				ln->ln_state = ND6_LLINFO_NOSTATE;
849 			}
850 		} else
851 			return(NULL);
852 	}
853 	rt->rt_refcnt--;
854 	/*
855 	 * Validation for the entry.
856 	 * Note that the check for rt_llinfo is necessary because a cloned
857 	 * route from a parent route that has the L flag (e.g. the default
858 	 * route to a p2p interface) may have the flag, too, while the
859 	 * destination is not actually a neighbor.
860 	 * XXX: we can't use rt->rt_ifp to check for the interface, since
861 	 *      it might be the loopback interface if the entry is for our
862 	 *      own address on a non-loopback interface. Instead, we should
863 	 *      use rt->rt_ifa->ifa_ifp, which would specify the REAL
864 	 *      interface.
865 	 */
866 	if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 ||
867 	    rt->rt_gateway->sa_family != AF_LINK || rt->rt_llinfo == NULL ||
868 	    (ifp && rt->rt_ifa->ifa_ifp != ifp)) {
869 		if (create) {
870 			log(LOG_DEBUG, "nd6_lookup: failed to lookup %s (if = %s)\n",
871 			    ip6_sprintf(addr6), ifp ? if_name(ifp) : "unspec");
872 			/* xxx more logs... kazu */
873 		}
874 		return(NULL);
875 	}
876 	return(rt);
877 }
878 
879 /*
880  * Detect if a given IPv6 address identifies a neighbor on a given link.
881  * XXX: should take care of the destination of a p2p link?
882  */
883 int
884 nd6_is_addr_neighbor(struct sockaddr_in6 *addr, struct ifnet *ifp)
885 {
886 	struct ifaddr *ifa;
887 	int i;
888 
889 #define IFADDR6(a) ((((struct in6_ifaddr *)(a))->ia_addr).sin6_addr)
890 #define IFMASK6(a) ((((struct in6_ifaddr *)(a))->ia_prefixmask).sin6_addr)
891 
892 	/*
893 	 * A link-local address is always a neighbor.
894 	 * XXX: we should use the sin6_scope_id field rather than the embedded
895 	 * interface index.
896 	 */
897 	if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr) &&
898 	    ntohs(*(u_int16_t *)&addr->sin6_addr.s6_addr[2]) == ifp->if_index)
899 		return(1);
900 
901 	/*
902 	 * If the address matches one of our addresses,
903 	 * it should be a neighbor.
904 	 */
905 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
906 		if (ifa->ifa_addr->sa_family != AF_INET6)
907 			next: continue;
908 
909 		for (i = 0; i < 4; i++) {
910 			if ((IFADDR6(ifa).s6_addr32[i] ^
911 			     addr->sin6_addr.s6_addr32[i]) &
912 			    IFMASK6(ifa).s6_addr32[i])
913 				goto next;
914 		}
915 		return(1);
916 	}
917 
918 	/*
919 	 * Even if the address matches none of our addresses, it might be
920 	 * in the neighbor cache.
921 	 */
922 	if (nd6_lookup(&addr->sin6_addr, 0, ifp) != NULL)
923 		return(1);
924 
925 	return(0);
926 #undef IFADDR6
927 #undef IFMASK6
928 }
929 
930 /*
931  * Free an nd6 llinfo entry.
932  */
933 struct llinfo_nd6 *
934 nd6_free(struct rtentry *rt)
935 {
936 	struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo, *next;
937 	struct in6_addr in6 = ((struct sockaddr_in6 *)rt_key(rt))->sin6_addr;
938 	struct nd_defrouter *dr;
939 
940 	/*
941 	 * we used to have pfctlinput(PRC_HOSTDEAD) here.
942 	 * even though it is not harmful, it was not really necessary.
943 	 */
944 
945 	if (!ip6_forwarding && ip6_accept_rtadv) { /* XXX: too restrictive? */
946 		int s;
947 		s = splnet();
948 		dr = defrouter_lookup(&((struct sockaddr_in6 *)rt_key(rt))->sin6_addr,
949 				      rt->rt_ifp);
950 
951 		if (ln->ln_router || dr) {
952 			/*
953 			 * rt6_flush must be called whether or not the neighbor
954 			 * is in the Default Router List.
955 			 * See a corresponding comment in nd6_na_input().
956 			 */
957 			rt6_flush(&in6, rt->rt_ifp);
958 		}
959 
960 		if (dr) {
961 			/*
962 			 * Unreachablity of a router might affect the default
963 			 * router selection and on-link detection of advertised
964 			 * prefixes.
965 			 */
966 
967 			/*
968 			 * Temporarily fake the state to choose a new default
969 			 * router and to perform on-link determination of
970 			 * prefixes correctly.
971 			 * Below the state will be set correctly,
972 			 * or the entry itself will be deleted.
973 			 */
974 			ln->ln_state = ND6_LLINFO_INCOMPLETE;
975 
976 			/*
977 			 * Since defrouter_select() does not affect the
978 			 * on-link determination and MIP6 needs the check
979 			 * before the default router selection, we perform
980 			 * the check now.
981 			 */
982 			pfxlist_onlink_check();
983 
984 			if (dr == TAILQ_FIRST(&nd_defrouter)) {
985 				/*
986 				 * It is used as the current default router,
987 				 * so we have to move it to the end of the
988 				 * list and choose a new one.
989 				 * XXX: it is not very efficient if this is
990 				 *      the only router.
991 				 */
992 				TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
993 				TAILQ_INSERT_TAIL(&nd_defrouter, dr, dr_entry);
994 
995 				defrouter_select();
996 			}
997 		}
998 		splx(s);
999 	}
1000 
1001 	/*
1002 	 * Before deleting the entry, remember the next entry as the
1003 	 * return value.  We need this because pfxlist_onlink_check() above
1004 	 * might have freed other entries (particularly the old next entry) as
1005 	 * a side effect (XXX).
1006 	 */
1007 	next = ln->ln_next;
1008 
1009 	/*
1010 	 * Detach the route from the routing tree and the list of neighbor
1011 	 * caches, and disable the route entry not to be used in already
1012 	 * cached routes.
1013 	 */
1014 	rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0,
1015 		  rt_mask(rt), 0, (struct rtentry **)0);
1016 
1017 	return(next);
1018 }
1019 
1020 /*
1021  * Upper-layer reachability hint for Neighbor Unreachability Detection.
1022  *
1023  * XXX cost-effective metods?
1024  */
1025 void
1026 nd6_nud_hint(struct rtentry *rt, struct in6_addr *dst6, int force)
1027 {
1028 	struct llinfo_nd6 *ln;
1029 
1030 	/*
1031 	 * If the caller specified "rt", use that.  Otherwise, resolve the
1032 	 * routing table by supplied "dst6".
1033 	 */
1034 	if (!rt) {
1035 		if (!dst6)
1036 			return;
1037 		if (!(rt = nd6_lookup(dst6, 0, NULL)))
1038 			return;
1039 	}
1040 
1041 	if ((rt->rt_flags & RTF_GATEWAY) != 0 ||
1042 	    (rt->rt_flags & RTF_LLINFO) == 0 ||
1043 	    !rt->rt_llinfo || !rt->rt_gateway ||
1044 	    rt->rt_gateway->sa_family != AF_LINK) {
1045 		/* This is not a host route. */
1046 		return;
1047 	}
1048 
1049 	ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1050 	if (ln->ln_state < ND6_LLINFO_REACHABLE)
1051 		return;
1052 
1053 	/*
1054 	 * if we get upper-layer reachability confirmation many times,
1055 	 * it is possible we have false information.
1056 	 */
1057 	if (!force) {
1058 		ln->ln_byhint++;
1059 		if (ln->ln_byhint > nd6_maxnudhint)
1060 			return;
1061 	}
1062 
1063 	ln->ln_state = ND6_LLINFO_REACHABLE;
1064 	if (ln->ln_expire)
1065 		ln->ln_expire = time_second +
1066 			nd_ifinfo[rt->rt_ifp->if_index].reachable;
1067 }
1068 
1069 void
1070 nd6_rtrequest(int req, struct rtentry *rt,
1071 	      struct rt_addrinfo *info) /* xxx unused */
1072 {
1073 	struct sockaddr *gate = rt->rt_gateway;
1074 	struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1075 	static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
1076 	struct ifnet *ifp = rt->rt_ifp;
1077 	struct ifaddr *ifa;
1078 
1079 	if ((rt->rt_flags & RTF_GATEWAY))
1080 		return;
1081 
1082 	if (nd6_need_cache(ifp) == 0 && (rt->rt_flags & RTF_HOST) == 0) {
1083 		/*
1084 		 * This is probably an interface direct route for a link
1085 		 * which does not need neighbor caches (e.g. fe80::%lo0/64).
1086 		 * We do not need special treatment below for such a route.
1087 		 * Moreover, the RTF_LLINFO flag which would be set below
1088 		 * would annoy the ndp(8) command.
1089 		 */
1090 		return;
1091 	}
1092 
1093 	if (req == RTM_RESOLVE &&
1094 	    (nd6_need_cache(ifp) == 0 || /* stf case */
1095 	     !nd6_is_addr_neighbor((struct sockaddr_in6 *)rt_key(rt), ifp))) {
1096 		/*
1097 		 * FreeBSD and BSD/OS often make a cloned host route based
1098 		 * on a less-specific route (e.g. the default route).
1099 		 * If the less specific route does not have a "gateway"
1100 		 * (this is the case when the route just goes to a p2p or an
1101 		 * stf interface), we'll mistakenly make a neighbor cache for
1102 		 * the host route, and will see strange neighbor solicitation
1103 		 * for the corresponding destination.  In order to avoid the
1104 		 * confusion, we check if the destination of the route is
1105 		 * a neighbor in terms of neighbor discovery, and stop the
1106 		 * process if not.  Additionally, we remove the LLINFO flag
1107 		 * so that ndp(8) will not try to get the neighbor information
1108 		 * of the destination.
1109 		 */
1110 		rt->rt_flags &= ~RTF_LLINFO;
1111 		return;
1112 	}
1113 
1114 	switch (req) {
1115 	case RTM_ADD:
1116 		/*
1117 		 * There is no backward compatibility :)
1118 		 *
1119 		 * if ((rt->rt_flags & RTF_HOST) == 0 &&
1120 		 *     SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff)
1121 		 *	   rt->rt_flags |= RTF_CLONING;
1122 		 */
1123 		if (rt->rt_flags & (RTF_CLONING | RTF_LLINFO)) {
1124 			/*
1125 			 * Case 1: This route should come from
1126 			 * a route to interface.  RTF_LLINFO flag is set
1127 			 * for a host route whose destination should be
1128 			 * treated as on-link.
1129 			 */
1130 			rt_setgate(rt, rt_key(rt),
1131 				   (struct sockaddr *)&null_sdl);
1132 			gate = rt->rt_gateway;
1133 			SDL(gate)->sdl_type = ifp->if_type;
1134 			SDL(gate)->sdl_index = ifp->if_index;
1135 			if (ln)
1136 				ln->ln_expire = time_second;
1137 #if 1
1138 			if (ln && ln->ln_expire == 0) {
1139 				/* kludge for desktops */
1140 #if 0
1141 				printf("nd6_rtequest: time.tv_sec is zero; "
1142 				       "treat it as 1\n");
1143 #endif
1144 				ln->ln_expire = 1;
1145 			}
1146 #endif
1147 			if ((rt->rt_flags & RTF_CLONING))
1148 				break;
1149 		}
1150 		/*
1151 		 * In IPv4 code, we try to annonuce new RTF_ANNOUNCE entry here.
1152 		 * We don't do that here since llinfo is not ready yet.
1153 		 *
1154 		 * There are also couple of other things to be discussed:
1155 		 * - unsolicited NA code needs improvement beforehand
1156 		 * - RFC2461 says we MAY send multicast unsolicited NA
1157 		 *   (7.2.6 paragraph 4), however, it also says that we
1158 		 *   SHOULD provide a mechanism to prevent multicast NA storm.
1159 		 *   we don't have anything like it right now.
1160 		 *   note that the mechanism needs a mutual agreement
1161 		 *   between proxies, which means that we need to implement
1162 		 *   a new protocol, or a new kludge.
1163 		 * - from RFC2461 6.2.4, host MUST NOT send an unsolicited NA.
1164 		 *   we need to check ip6forwarding before sending it.
1165 		 *   (or should we allow proxy ND configuration only for
1166 		 *   routers?  there's no mention about proxy ND from hosts)
1167 		 */
1168 #if 0
1169 		/* XXX it does not work */
1170 		if (rt->rt_flags & RTF_ANNOUNCE)
1171 			nd6_na_output(ifp,
1172 			      &SIN6(rt_key(rt))->sin6_addr,
1173 			      &SIN6(rt_key(rt))->sin6_addr,
1174 			      ip6_forwarding ? ND_NA_FLAG_ROUTER : 0,
1175 			      1, NULL);
1176 #endif
1177 		/* FALLTHROUGH */
1178 	case RTM_RESOLVE:
1179 		if ((ifp->if_flags & (IFF_POINTOPOINT | IFF_LOOPBACK)) == 0) {
1180 			/*
1181 			 * Address resolution isn't necessary for a point to
1182 			 * point link, so we can skip this test for a p2p link.
1183 			 */
1184 			if (gate->sa_family != AF_LINK ||
1185 			    gate->sa_len < sizeof(null_sdl)) {
1186 				log(LOG_DEBUG,
1187 				    "nd6_rtrequest: bad gateway value: %s\n",
1188 				    if_name(ifp));
1189 				break;
1190 			}
1191 			SDL(gate)->sdl_type = ifp->if_type;
1192 			SDL(gate)->sdl_index = ifp->if_index;
1193 		}
1194 		if (ln != NULL)
1195 			break;	/* This happens on a route change */
1196 		/*
1197 		 * Case 2: This route may come from cloning, or a manual route
1198 		 * add with a LL address.
1199 		 */
1200 		R_Malloc(ln, struct llinfo_nd6 *, sizeof(*ln));
1201 		rt->rt_llinfo = (caddr_t)ln;
1202 		if (!ln) {
1203 			log(LOG_DEBUG, "nd6_rtrequest: malloc failed\n");
1204 			break;
1205 		}
1206 		nd6_inuse++;
1207 		nd6_allocated++;
1208 		bzero(ln, sizeof(*ln));
1209 		ln->ln_rt = rt;
1210 		/* this is required for "ndp" command. - shin */
1211 		if (req == RTM_ADD) {
1212 		        /*
1213 			 * gate should have some valid AF_LINK entry,
1214 			 * and ln->ln_expire should have some lifetime
1215 			 * which is specified by ndp command.
1216 			 */
1217 			ln->ln_state = ND6_LLINFO_REACHABLE;
1218 			ln->ln_byhint = 0;
1219 		} else {
1220 		        /*
1221 			 * When req == RTM_RESOLVE, rt is created and
1222 			 * initialized in rtrequest(), so rt_expire is 0.
1223 			 */
1224 			ln->ln_state = ND6_LLINFO_NOSTATE;
1225 			ln->ln_expire = time_second;
1226 		}
1227 		rt->rt_flags |= RTF_LLINFO;
1228 		ln->ln_next = llinfo_nd6.ln_next;
1229 		llinfo_nd6.ln_next = ln;
1230 		ln->ln_prev = &llinfo_nd6;
1231 		ln->ln_next->ln_prev = ln;
1232 
1233 		/*
1234 		 * check if rt_key(rt) is one of my address assigned
1235 		 * to the interface.
1236 		 */
1237 		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(rt->rt_ifp,
1238 					  &SIN6(rt_key(rt))->sin6_addr);
1239 		if (ifa) {
1240 			caddr_t macp = nd6_ifptomac(ifp);
1241 			ln->ln_expire = 0;
1242 			ln->ln_state = ND6_LLINFO_REACHABLE;
1243 			ln->ln_byhint = 0;
1244 			if (macp) {
1245 				bcopy(macp, LLADDR(SDL(gate)), ifp->if_addrlen);
1246 				SDL(gate)->sdl_alen = ifp->if_addrlen;
1247 			}
1248 			if (nd6_useloopback) {
1249 				rt->rt_ifp = &loif[0];	/* XXX */
1250 				/*
1251 				 * Make sure rt_ifa be equal to the ifaddr
1252 				 * corresponding to the address.
1253 				 * We need this because when we refer
1254 				 * rt_ifa->ia6_flags in ip6_input, we assume
1255 				 * that the rt_ifa points to the address instead
1256 				 * of the loopback address.
1257 				 */
1258 				if (ifa != rt->rt_ifa) {
1259 					IFAFREE(rt->rt_ifa);
1260 					IFAREF(ifa);
1261 					rt->rt_ifa = ifa;
1262 				}
1263 			}
1264 		} else if (rt->rt_flags & RTF_ANNOUNCE) {
1265 			ln->ln_expire = 0;
1266 			ln->ln_state = ND6_LLINFO_REACHABLE;
1267 			ln->ln_byhint = 0;
1268 
1269 			/* join solicited node multicast for proxy ND */
1270 			if (ifp->if_flags & IFF_MULTICAST) {
1271 				struct in6_addr llsol;
1272 				int error;
1273 
1274 				llsol = SIN6(rt_key(rt))->sin6_addr;
1275 				llsol.s6_addr16[0] = htons(0xff02);
1276 				llsol.s6_addr16[1] = htons(ifp->if_index);
1277 				llsol.s6_addr32[1] = 0;
1278 				llsol.s6_addr32[2] = htonl(1);
1279 				llsol.s6_addr8[12] = 0xff;
1280 
1281 				if (!in6_addmulti(&llsol, ifp, &error)) {
1282 					nd6log((LOG_ERR, "%s: failed to join "
1283 					    "%s (errno=%d)\n", if_name(ifp),
1284 					    ip6_sprintf(&llsol), error));
1285 				}
1286 			}
1287 		}
1288 		break;
1289 
1290 	case RTM_DELETE:
1291 		if (!ln)
1292 			break;
1293 		/* leave from solicited node multicast for proxy ND */
1294 		if ((rt->rt_flags & RTF_ANNOUNCE) != 0 &&
1295 		    (ifp->if_flags & IFF_MULTICAST) != 0) {
1296 			struct in6_addr llsol;
1297 			struct in6_multi *in6m;
1298 
1299 			llsol = SIN6(rt_key(rt))->sin6_addr;
1300 			llsol.s6_addr16[0] = htons(0xff02);
1301 			llsol.s6_addr16[1] = htons(ifp->if_index);
1302 			llsol.s6_addr32[1] = 0;
1303 			llsol.s6_addr32[2] = htonl(1);
1304 			llsol.s6_addr8[12] = 0xff;
1305 
1306 			IN6_LOOKUP_MULTI(llsol, ifp, in6m);
1307 			if (in6m)
1308 				in6_delmulti(in6m);
1309 		}
1310 		nd6_inuse--;
1311 		ln->ln_next->ln_prev = ln->ln_prev;
1312 		ln->ln_prev->ln_next = ln->ln_next;
1313 		ln->ln_prev = NULL;
1314 		rt->rt_llinfo = 0;
1315 		rt->rt_flags &= ~RTF_LLINFO;
1316 		if (ln->ln_hold)
1317 			m_freem(ln->ln_hold);
1318 		Free((caddr_t)ln);
1319 	}
1320 }
1321 
1322 int
1323 nd6_ioctl(u_long cmd, caddr_t	data, struct ifnet *ifp)
1324 {
1325 	struct in6_drlist *drl = (struct in6_drlist *)data;
1326 	struct in6_prlist *prl = (struct in6_prlist *)data;
1327 	struct in6_ndireq *ndi = (struct in6_ndireq *)data;
1328 	struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data;
1329 	struct in6_ndifreq *ndif = (struct in6_ndifreq *)data;
1330 	struct nd_defrouter *dr, any;
1331 	struct nd_prefix *pr;
1332 	struct rtentry *rt;
1333 	int i = 0, error = 0;
1334 	int s;
1335 
1336 	switch (cmd) {
1337 	case SIOCGDRLST_IN6:
1338 		/*
1339 		 * obsolete API, use sysctl under net.inet6.icmp6
1340 		 */
1341 		bzero(drl, sizeof(*drl));
1342 		s = splnet();
1343 		dr = TAILQ_FIRST(&nd_defrouter);
1344 		while (dr && i < DRLSTSIZ) {
1345 			drl->defrouter[i].rtaddr = dr->rtaddr;
1346 			if (IN6_IS_ADDR_LINKLOCAL(&drl->defrouter[i].rtaddr)) {
1347 				/* XXX: need to this hack for KAME stack */
1348 				drl->defrouter[i].rtaddr.s6_addr16[1] = 0;
1349 			} else
1350 				log(LOG_ERR,
1351 				    "default router list contains a "
1352 				    "non-linklocal address(%s)\n",
1353 				    ip6_sprintf(&drl->defrouter[i].rtaddr));
1354 
1355 			drl->defrouter[i].flags = dr->flags;
1356 			drl->defrouter[i].rtlifetime = dr->rtlifetime;
1357 			drl->defrouter[i].expire = dr->expire;
1358 			drl->defrouter[i].if_index = dr->ifp->if_index;
1359 			i++;
1360 			dr = TAILQ_NEXT(dr, dr_entry);
1361 		}
1362 		splx(s);
1363 		break;
1364 	case SIOCGPRLST_IN6:
1365 		/*
1366 		 * obsolete API, use sysctl under net.inet6.icmp6
1367 		 */
1368 		/*
1369 		 * XXX meaning of fields, especialy "raflags", is very
1370 		 * differnet between RA prefix list and RR/static prefix list.
1371 		 * how about separating ioctls into two?
1372 		 */
1373 		bzero(prl, sizeof(*prl));
1374 		s = splnet();
1375 		pr = nd_prefix.lh_first;
1376 		while (pr && i < PRLSTSIZ) {
1377 			struct nd_pfxrouter *pfr;
1378 			int j;
1379 
1380 			(void)in6_embedscope(&prl->prefix[i].prefix,
1381 			    &pr->ndpr_prefix, NULL, NULL);
1382 			prl->prefix[i].raflags = pr->ndpr_raf;
1383 			prl->prefix[i].prefixlen = pr->ndpr_plen;
1384 			prl->prefix[i].vltime = pr->ndpr_vltime;
1385 			prl->prefix[i].pltime = pr->ndpr_pltime;
1386 			prl->prefix[i].if_index = pr->ndpr_ifp->if_index;
1387 			prl->prefix[i].expire = pr->ndpr_expire;
1388 
1389 			pfr = pr->ndpr_advrtrs.lh_first;
1390 			j = 0;
1391 			while (pfr) {
1392 				if (j < DRLSTSIZ) {
1393 #define RTRADDR prl->prefix[i].advrtr[j]
1394 					RTRADDR = pfr->router->rtaddr;
1395 					if (IN6_IS_ADDR_LINKLOCAL(&RTRADDR)) {
1396 						/* XXX: hack for KAME */
1397 						RTRADDR.s6_addr16[1] = 0;
1398 					} else
1399 						log(LOG_ERR,
1400 						    "a router(%s) advertises "
1401 						    "a prefix with "
1402 						    "non-link local address\n",
1403 						    ip6_sprintf(&RTRADDR));
1404 #undef RTRADDR
1405 				}
1406 				j++;
1407 				pfr = pfr->pfr_next;
1408 			}
1409 			prl->prefix[i].advrtrs = j;
1410 			prl->prefix[i].origin = PR_ORIG_RA;
1411 
1412 			i++;
1413 			pr = pr->ndpr_next;
1414 		}
1415 	      {
1416 		struct rr_prefix *rpp;
1417 
1418 		for (rpp = LIST_FIRST(&rr_prefix); rpp;
1419 		     rpp = LIST_NEXT(rpp, rp_entry)) {
1420 			if (i >= PRLSTSIZ)
1421 				break;
1422 			(void)in6_embedscope(&prl->prefix[i].prefix,
1423 			    &pr->ndpr_prefix, NULL, NULL);
1424 			prl->prefix[i].raflags = rpp->rp_raf;
1425 			prl->prefix[i].prefixlen = rpp->rp_plen;
1426 			prl->prefix[i].vltime = rpp->rp_vltime;
1427 			prl->prefix[i].pltime = rpp->rp_pltime;
1428 			prl->prefix[i].if_index = rpp->rp_ifp->if_index;
1429 			prl->prefix[i].expire = rpp->rp_expire;
1430 			prl->prefix[i].advrtrs = 0;
1431 			prl->prefix[i].origin = rpp->rp_origin;
1432 			i++;
1433 		}
1434 	      }
1435 		splx(s);
1436 
1437 		break;
1438 	case OSIOCGIFINFO_IN6:
1439 		if (!nd_ifinfo || i >= nd_ifinfo_indexlim) {
1440 			error = EINVAL;
1441 			break;
1442 		}
1443 		ndi->ndi.linkmtu = nd_ifinfo[ifp->if_index].linkmtu;
1444 		ndi->ndi.maxmtu = nd_ifinfo[ifp->if_index].maxmtu;
1445 		ndi->ndi.basereachable =
1446 		    nd_ifinfo[ifp->if_index].basereachable;
1447 		ndi->ndi.reachable = nd_ifinfo[ifp->if_index].reachable;
1448 		ndi->ndi.retrans = nd_ifinfo[ifp->if_index].retrans;
1449 		ndi->ndi.flags = nd_ifinfo[ifp->if_index].flags;
1450 		ndi->ndi.recalctm = nd_ifinfo[ifp->if_index].recalctm;
1451 		ndi->ndi.chlim = nd_ifinfo[ifp->if_index].chlim;
1452 		ndi->ndi.receivedra = nd_ifinfo[ifp->if_index].receivedra;
1453 		break;
1454 	case SIOCGIFINFO_IN6:
1455 		if (!nd_ifinfo || i >= nd_ifinfo_indexlim) {
1456 			error = EINVAL;
1457 			break;
1458 		}
1459 		ndi->ndi = nd_ifinfo[ifp->if_index];
1460 		break;
1461 	case SIOCSIFINFO_FLAGS:
1462 		/* XXX: almost all other fields of ndi->ndi is unused */
1463 		if (!nd_ifinfo || i >= nd_ifinfo_indexlim) {
1464 			error = EINVAL;
1465 			break;
1466 		}
1467 		nd_ifinfo[ifp->if_index].flags = ndi->ndi.flags;
1468 		break;
1469 	case SIOCSNDFLUSH_IN6:	/* XXX: the ioctl name is confusing... */
1470 		/* flush default router list */
1471 		/*
1472 		 * xxx sumikawa: should not delete route if default
1473 		 * route equals to the top of default router list
1474 		 */
1475 		bzero(&any, sizeof(any));
1476 		defrouter_delreq(&any, 0);
1477 		defrouter_select();
1478 		/* xxx sumikawa: flush prefix list */
1479 		break;
1480 	case SIOCSPFXFLUSH_IN6:
1481 	    {
1482 		/* flush all the prefix advertised by routers */
1483 		struct nd_prefix *pr, *next;
1484 
1485 		s = splnet();
1486 		for (pr = nd_prefix.lh_first; pr; pr = next) {
1487 			struct in6_ifaddr *ia, *ia_next;
1488 
1489 			next = pr->ndpr_next;
1490 
1491 			if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1492 				continue; /* XXX */
1493 
1494 			/* do we really have to remove addresses as well? */
1495 			for (ia = in6_ifaddr; ia; ia = ia_next) {
1496 				/* ia might be removed.  keep the next ptr. */
1497 				ia_next = ia->ia_next;
1498 
1499 				if ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1500 					continue;
1501 
1502 				if (ia->ia6_ndpr == pr)
1503 					in6_purgeaddr(&ia->ia_ifa);
1504 			}
1505 			prelist_remove(pr);
1506 		}
1507 		splx(s);
1508 		break;
1509 	    }
1510 	case SIOCSRTRFLUSH_IN6:
1511 	    {
1512 		/* flush all the default routers */
1513 		struct nd_defrouter *dr, *next;
1514 
1515 		s = splnet();
1516 		if ((dr = TAILQ_FIRST(&nd_defrouter)) != NULL) {
1517 			/*
1518 			 * The first entry of the list may be stored in
1519 			 * the routing table, so we'll delete it later.
1520 			 */
1521 			for (dr = TAILQ_NEXT(dr, dr_entry); dr; dr = next) {
1522 				next = TAILQ_NEXT(dr, dr_entry);
1523 				defrtrlist_del(dr);
1524 			}
1525 			defrtrlist_del(TAILQ_FIRST(&nd_defrouter));
1526 		}
1527 		splx(s);
1528 		break;
1529 	    }
1530 	case SIOCGNBRINFO_IN6:
1531 	    {
1532 		struct llinfo_nd6 *ln;
1533 		struct in6_addr nb_addr = nbi->addr; /* make local for safety */
1534 
1535 		/*
1536 		 * XXX: KAME specific hack for scoped addresses
1537 		 *      XXXX: for other scopes than link-local?
1538 		 */
1539 		if (IN6_IS_ADDR_LINKLOCAL(&nbi->addr) ||
1540 		    IN6_IS_ADDR_MC_LINKLOCAL(&nbi->addr)) {
1541 			u_int16_t *idp = (u_int16_t *)&nb_addr.s6_addr[2];
1542 
1543 			if (*idp == 0)
1544 				*idp = htons(ifp->if_index);
1545 		}
1546 
1547 		s = splnet();
1548 		if ((rt = nd6_lookup(&nb_addr, 0, ifp)) == NULL) {
1549 			error = EINVAL;
1550 			splx(s);
1551 			break;
1552 		}
1553 		ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1554 		nbi->state = ln->ln_state;
1555 		nbi->asked = ln->ln_asked;
1556 		nbi->isrouter = ln->ln_router;
1557 		nbi->expire = ln->ln_expire;
1558 		splx(s);
1559 
1560 		break;
1561 	    }
1562 	case SIOCGDEFIFACE_IN6:	/* XXX: should be implemented as a sysctl? */
1563 		ndif->ifindex = nd6_defifindex;
1564 		break;
1565 	case SIOCSDEFIFACE_IN6:	/* XXX: should be implemented as a sysctl? */
1566 		return(nd6_setdefaultiface(ndif->ifindex));
1567 		break;
1568 	}
1569 	return(error);
1570 }
1571 
1572 /*
1573  * Create neighbor cache entry and cache link-layer address,
1574  * on reception of inbound ND6 packets. (RS/RA/NS/redirect)
1575  */
1576 struct rtentry *
1577 nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr,
1578 		 int lladdrlen,
1579 		 int type,	/* ICMP6 type */
1580 		 int code	/* type dependent information */)
1581 {
1582 	struct rtentry *rt = NULL;
1583 	struct llinfo_nd6 *ln = NULL;
1584 	int is_newentry;
1585 	struct sockaddr_dl *sdl = NULL;
1586 	int do_update;
1587 	int olladdr;
1588 	int llchange;
1589 	int newstate = 0;
1590 
1591 	if (!ifp)
1592 		panic("ifp == NULL in nd6_cache_lladdr");
1593 	if (!from)
1594 		panic("from == NULL in nd6_cache_lladdr");
1595 
1596 	/* nothing must be updated for unspecified address */
1597 	if (IN6_IS_ADDR_UNSPECIFIED(from))
1598 		return NULL;
1599 
1600 	/*
1601 	 * Validation about ifp->if_addrlen and lladdrlen must be done in
1602 	 * the caller.
1603 	 *
1604 	 * XXX If the link does not have link-layer adderss, what should
1605 	 * we do? (ifp->if_addrlen == 0)
1606 	 * Spec says nothing in sections for RA, RS and NA.  There's small
1607 	 * description on it in NS section (RFC 2461 7.2.3).
1608 	 */
1609 
1610 	rt = nd6_lookup(from, 0, ifp);
1611 	if (!rt) {
1612 #if 0
1613 		/* nothing must be done if there's no lladdr */
1614 		if (!lladdr || !lladdrlen)
1615 			return NULL;
1616 #endif
1617 
1618 		rt = nd6_lookup(from, 1, ifp);
1619 		is_newentry = 1;
1620 	} else {
1621 		/* do nothing if static ndp is set */
1622 		if (rt->rt_flags & RTF_STATIC)
1623 			return NULL;
1624 		is_newentry = 0;
1625 	}
1626 
1627 	if (!rt)
1628 		return NULL;
1629 	if ((rt->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) != RTF_LLINFO) {
1630 fail:
1631 		(void)nd6_free(rt);
1632 		return NULL;
1633 	}
1634 	ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1635 	if (!ln)
1636 		goto fail;
1637 	if (!rt->rt_gateway)
1638 		goto fail;
1639 	if (rt->rt_gateway->sa_family != AF_LINK)
1640 		goto fail;
1641 	sdl = SDL(rt->rt_gateway);
1642 
1643 	olladdr = (sdl->sdl_alen) ? 1 : 0;
1644 	if (olladdr && lladdr) {
1645 		if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen))
1646 			llchange = 1;
1647 		else
1648 			llchange = 0;
1649 	} else
1650 		llchange = 0;
1651 
1652 	/*
1653 	 * newentry olladdr  lladdr  llchange	(*=record)
1654 	 *	0	n	n	--	(1)
1655 	 *	0	y	n	--	(2)
1656 	 *	0	n	y	--	(3) * STALE
1657 	 *	0	y	y	n	(4) *
1658 	 *	0	y	y	y	(5) * STALE
1659 	 *	1	--	n	--	(6)   NOSTATE(= PASSIVE)
1660 	 *	1	--	y	--	(7) * STALE
1661 	 */
1662 
1663 	if (lladdr) {		/* (3-5) and (7) */
1664 		/*
1665 		 * Record source link-layer address
1666 		 * XXX is it dependent to ifp->if_type?
1667 		 */
1668 		sdl->sdl_alen = ifp->if_addrlen;
1669 		bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen);
1670 	}
1671 
1672 	if (!is_newentry) {
1673 		if ((!olladdr && lladdr)		/* (3) */
1674 		 || (olladdr && lladdr && llchange)) {	/* (5) */
1675 			do_update = 1;
1676 			newstate = ND6_LLINFO_STALE;
1677 		} else					/* (1-2,4) */
1678 			do_update = 0;
1679 	} else {
1680 		do_update = 1;
1681 		if (!lladdr)				/* (6) */
1682 			newstate = ND6_LLINFO_NOSTATE;
1683 		else					/* (7) */
1684 			newstate = ND6_LLINFO_STALE;
1685 	}
1686 
1687 	if (do_update) {
1688 		/*
1689 		 * Update the state of the neighbor cache.
1690 		 */
1691 		ln->ln_state = newstate;
1692 
1693 		if (ln->ln_state == ND6_LLINFO_STALE) {
1694 			/*
1695 			 * XXX: since nd6_output() below will cause
1696 			 * state tansition to DELAY and reset the timer,
1697 			 * we must set the timer now, although it is actually
1698 			 * meaningless.
1699 			 */
1700 			ln->ln_expire = time_second + nd6_gctimer;
1701 
1702 			if (ln->ln_hold) {
1703 				/*
1704 				 * we assume ifp is not a p2p here, so just
1705 				 * set the 2nd argument as the 1st one.
1706 				 */
1707 				nd6_output(ifp, ifp, ln->ln_hold,
1708 					   (struct sockaddr_in6 *)rt_key(rt),
1709 					   rt);
1710 				ln->ln_hold = NULL;
1711 			}
1712 		} else if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
1713 			/* probe right away */
1714 			ln->ln_expire = time_second;
1715 		}
1716 	}
1717 
1718 	/*
1719 	 * ICMP6 type dependent behavior.
1720 	 *
1721 	 * NS: clear IsRouter if new entry
1722 	 * RS: clear IsRouter
1723 	 * RA: set IsRouter if there's lladdr
1724 	 * redir: clear IsRouter if new entry
1725 	 *
1726 	 * RA case, (1):
1727 	 * The spec says that we must set IsRouter in the following cases:
1728 	 * - If lladdr exist, set IsRouter.  This means (1-5).
1729 	 * - If it is old entry (!newentry), set IsRouter.  This means (7).
1730 	 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
1731 	 * A quetion arises for (1) case.  (1) case has no lladdr in the
1732 	 * neighbor cache, this is similar to (6).
1733 	 * This case is rare but we figured that we MUST NOT set IsRouter.
1734 	 *
1735 	 * newentry olladdr  lladdr  llchange	    NS  RS  RA	redir
1736 	 *							D R
1737 	 *	0	n	n	--	(1)	c   ?     s
1738 	 *	0	y	n	--	(2)	c   s     s
1739 	 *	0	n	y	--	(3)	c   s     s
1740 	 *	0	y	y	n	(4)	c   s     s
1741 	 *	0	y	y	y	(5)	c   s     s
1742 	 *	1	--	n	--	(6) c	c 	c s
1743 	 *	1	--	y	--	(7) c	c   s	c s
1744 	 *
1745 	 *					(c=clear s=set)
1746 	 */
1747 	switch (type & 0xff) {
1748 	case ND_NEIGHBOR_SOLICIT:
1749 		/*
1750 		 * New entry must have is_router flag cleared.
1751 		 */
1752 		if (is_newentry)	/* (6-7) */
1753 			ln->ln_router = 0;
1754 		break;
1755 	case ND_REDIRECT:
1756 		/*
1757 		 * If the icmp is a redirect to a better router, always set the
1758 		 * is_router flag. Otherwise, if the entry is newly created,
1759 		 * clear the flag. [RFC 2461, sec 8.3]
1760 		 */
1761 		if (code == ND_REDIRECT_ROUTER)
1762 			ln->ln_router = 1;
1763 		else if (is_newentry) /* (6-7) */
1764 			ln->ln_router = 0;
1765 		break;
1766 	case ND_ROUTER_SOLICIT:
1767 		/*
1768 		 * is_router flag must always be cleared.
1769 		 */
1770 		ln->ln_router = 0;
1771 		break;
1772 	case ND_ROUTER_ADVERT:
1773 		/*
1774 		 * Mark an entry with lladdr as a router.
1775 		 */
1776 		if ((!is_newentry && (olladdr || lladdr))	/* (2-5) */
1777 		 || (is_newentry && lladdr)) {			/* (7) */
1778 			ln->ln_router = 1;
1779 		}
1780 		break;
1781 	}
1782 
1783 	/*
1784 	 * When the link-layer address of a router changes, select the
1785 	 * best router again.  In particular, when the neighbor entry is newly
1786 	 * created, it might affect the selection policy.
1787 	 * Question: can we restrict the first condition to the "is_newentry"
1788 	 * case?
1789 	 * XXX: when we hear an RA from a new router with the link-layer
1790 	 * address option, defrouter_select() is called twice, since
1791 	 * defrtrlist_update called the function as well.  However, I believe
1792 	 * we can compromise the overhead, since it only happens the first
1793 	 * time.
1794 	 * XXX: although defrouter_select() should not have a bad effect
1795 	 * for those are not autoconfigured hosts, we explicitly avoid such
1796 	 * cases for safety.
1797 	 */
1798 	if (do_update && ln->ln_router && !ip6_forwarding && ip6_accept_rtadv)
1799 		defrouter_select();
1800 
1801 	return rt;
1802 }
1803 
1804 static void
1805 nd6_slowtimo(void *ignored_arg)
1806 {
1807 	int s = splnet();
1808 	int i;
1809 	struct nd_ifinfo *nd6if;
1810 
1811 	callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
1812 	    nd6_slowtimo, NULL);
1813 	for (i = 1; i < if_index + 1; i++) {
1814 		if (!nd_ifinfo || i >= nd_ifinfo_indexlim)
1815 			continue;
1816 		nd6if = &nd_ifinfo[i];
1817 		if (nd6if->basereachable && /* already initialized */
1818 		    (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
1819 			/*
1820 			 * Since reachable time rarely changes by router
1821 			 * advertisements, we SHOULD insure that a new random
1822 			 * value gets recomputed at least once every few hours.
1823 			 * (RFC 2461, 6.3.4)
1824 			 */
1825 			nd6if->recalctm = nd6_recalc_reachtm_interval;
1826 			nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable);
1827 		}
1828 	}
1829 	splx(s);
1830 }
1831 
1832 #define senderr(e) { error = (e); goto bad;}
1833 int
1834 nd6_output(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m0,
1835 	   struct sockaddr_in6 *dst, struct rtentry *rt0)
1836 {
1837 	struct mbuf *m = m0;
1838 	struct rtentry *rt = rt0;
1839 	struct sockaddr_in6 *gw6 = NULL;
1840 	struct llinfo_nd6 *ln = NULL;
1841 	int error = 0;
1842 
1843 	if (IN6_IS_ADDR_MULTICAST(&dst->sin6_addr))
1844 		goto sendpkt;
1845 
1846 	if (nd6_need_cache(ifp) == 0)
1847 		goto sendpkt;
1848 
1849 	/*
1850 	 * next hop determination.  This routine is derived from ether_outpout.
1851 	 */
1852 	if (rt) {
1853 		if (!(rt->rt_flags & RTF_UP)) {
1854 			if ((rt0 = rt =
1855 			    rtlookup((struct sockaddr *)dst, 1, 0UL))) {
1856 				rt->rt_refcnt--;
1857 				if (rt->rt_ifp != ifp) {
1858 					/* XXX: loop care? */
1859 					return nd6_output(ifp, origifp, m0,
1860 							  dst, rt);
1861 				}
1862 			} else
1863 				senderr(EHOSTUNREACH);
1864 		}
1865 
1866 		if (rt->rt_flags & RTF_GATEWAY) {
1867 			gw6 = (struct sockaddr_in6 *)rt->rt_gateway;
1868 
1869 			/*
1870 			 * We skip link-layer address resolution and NUD
1871 			 * if the gateway is not a neighbor from ND point
1872 			 * of view, regardless of the value of nd_ifinfo.flags.
1873 			 * The second condition is a bit tricky; we skip
1874 			 * if the gateway is our own address, which is
1875 			 * sometimes used to install a route to a p2p link.
1876 			 */
1877 			if (!nd6_is_addr_neighbor(gw6, ifp) ||
1878 			    in6ifa_ifpwithaddr(ifp, &gw6->sin6_addr)) {
1879 				/*
1880 				 * We allow this kind of tricky route only
1881 				 * when the outgoing interface is p2p.
1882 				 * XXX: we may need a more generic rule here.
1883 				 */
1884 				if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
1885 					senderr(EHOSTUNREACH);
1886 
1887 				goto sendpkt;
1888 			}
1889 
1890 			if (rt->rt_gwroute == NULL)
1891 				goto lookup;
1892 			if (!(rt->rt_gwroute->rt_flags & RTF_UP)) {
1893 				rtfree(rt->rt_gwroute);
1894 lookup:				rt->rt_gwroute = rtlookup(rt->rt_gateway, 1,
1895 							  0UL);
1896 				if (rt->rt_gwroute == NULL)
1897 					senderr(EHOSTUNREACH);
1898 			}
1899 		}
1900 	}
1901 
1902 	/*
1903 	 * Address resolution or Neighbor Unreachability Detection
1904 	 * for the next hop.
1905 	 * At this point, the destination of the packet must be a unicast
1906 	 * or an anycast address(i.e. not a multicast).
1907 	 */
1908 
1909 	/* Look up the neighbor cache for the nexthop */
1910 	if (rt && (rt->rt_flags & RTF_LLINFO) != 0)
1911 		ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1912 	else {
1913 		/*
1914 		 * Since nd6_is_addr_neighbor() internally calls nd6_lookup(),
1915 		 * the condition below is not very efficient.  But we believe
1916 		 * it is tolerable, because this should be a rare case.
1917 		 */
1918 		if (nd6_is_addr_neighbor(dst, ifp) &&
1919 		    (rt = nd6_lookup(&dst->sin6_addr, 1, ifp)) != NULL)
1920 			ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1921 	}
1922 	if (!ln || !rt) {
1923 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0 &&
1924 		    !(nd_ifinfo[ifp->if_index].flags & ND6_IFF_PERFORMNUD)) {
1925 			log(LOG_DEBUG,
1926 			    "nd6_output: can't allocate llinfo for %s "
1927 			    "(ln=%p, rt=%p)\n",
1928 			    ip6_sprintf(&dst->sin6_addr), ln, rt);
1929 			senderr(EIO);	/* XXX: good error? */
1930 		}
1931 
1932 		goto sendpkt;	/* send anyway */
1933 	}
1934 
1935 	/* We don't have to do link-layer address resolution on a p2p link. */
1936 	if ((ifp->if_flags & IFF_POINTOPOINT) != 0 &&
1937 	    ln->ln_state < ND6_LLINFO_REACHABLE) {
1938 		ln->ln_state = ND6_LLINFO_STALE;
1939 		ln->ln_expire = time_second + nd6_gctimer;
1940 	}
1941 
1942 	/*
1943 	 * The first time we send a packet to a neighbor whose entry is
1944 	 * STALE, we have to change the state to DELAY and a sets a timer to
1945 	 * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do
1946 	 * neighbor unreachability detection on expiration.
1947 	 * (RFC 2461 7.3.3)
1948 	 */
1949 	if (ln->ln_state == ND6_LLINFO_STALE) {
1950 		ln->ln_asked = 0;
1951 		ln->ln_state = ND6_LLINFO_DELAY;
1952 		ln->ln_expire = time_second + nd6_delay;
1953 	}
1954 
1955 	/*
1956 	 * If the neighbor cache entry has a state other than INCOMPLETE
1957 	 * (i.e. its link-layer address is already resolved), just
1958 	 * send the packet.
1959 	 */
1960 	if (ln->ln_state > ND6_LLINFO_INCOMPLETE)
1961 		goto sendpkt;
1962 
1963 	/*
1964 	 * There is a neighbor cache entry, but no ethernet address
1965 	 * response yet.  Replace the held mbuf (if any) with this
1966 	 * latest one.
1967 	 *
1968 	 * This code conforms to the rate-limiting rule described in Section
1969 	 * 7.2.2 of RFC 2461, because the timer is set correctly after sending
1970 	 * an NS below.
1971 	 */
1972 	if (ln->ln_state == ND6_LLINFO_NOSTATE)
1973 		ln->ln_state = ND6_LLINFO_INCOMPLETE;
1974 	if (ln->ln_hold)
1975 		m_freem(ln->ln_hold);
1976 	ln->ln_hold = m;
1977 	if (ln->ln_expire) {
1978 		if (ln->ln_asked < nd6_mmaxtries &&
1979 		    ln->ln_expire < time_second) {
1980 			ln->ln_asked++;
1981 			ln->ln_expire = time_second +
1982 				nd_ifinfo[ifp->if_index].retrans / 1000;
1983 			nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0);
1984 		}
1985 	}
1986 	return(0);
1987 
1988   sendpkt:
1989 
1990 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
1991 		return((*ifp->if_output)(origifp, m, (struct sockaddr *)dst,
1992 					 rt));
1993 	}
1994 	return((*ifp->if_output)(ifp, m, (struct sockaddr *)dst, rt));
1995 
1996   bad:
1997 	if (m)
1998 		m_freem(m);
1999 	return (error);
2000 }
2001 #undef senderr
2002 
2003 int
2004 nd6_need_cache(struct ifnet *ifp)
2005 {
2006 	/*
2007 	 * XXX: we currently do not make neighbor cache on any interface
2008 	 * other than ARCnet, Ethernet, FDDI and GIF.
2009 	 *
2010 	 * RFC2893 says:
2011 	 * - unidirectional tunnels needs no ND
2012 	 */
2013 	switch (ifp->if_type) {
2014 	case IFT_ARCNET:
2015 	case IFT_ETHER:
2016 	case IFT_FDDI:
2017 	case IFT_IEEE1394:
2018 #ifdef IFT_L2VLAN
2019 	case IFT_L2VLAN:
2020 #endif
2021 #ifdef IFT_IEEE80211
2022 	case IFT_IEEE80211:
2023 #endif
2024 	case IFT_GIF:		/* XXX need more cases? */
2025 		return(1);
2026 	default:
2027 		return(0);
2028 	}
2029 }
2030 
2031 int
2032 nd6_storelladdr(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m,
2033 		struct sockaddr *dst, u_char *desten)
2034 {
2035 	struct sockaddr_dl *sdl;
2036 	struct rtentry *rt;
2037 
2038 
2039 	if (m->m_flags & M_MCAST) {
2040 		switch (ifp->if_type) {
2041 		case IFT_ETHER:
2042 		case IFT_FDDI:
2043 #ifdef IFT_L2VLAN
2044 	case IFT_L2VLAN:
2045 #endif
2046 #ifdef IFT_IEEE80211
2047 		case IFT_IEEE80211:
2048 #endif
2049 			ETHER_MAP_IPV6_MULTICAST(&SIN6(dst)->sin6_addr,
2050 						 desten);
2051 			return(1);
2052 		case IFT_IEEE1394:
2053 			bcopy(ifp->if_broadcastaddr, desten, ifp->if_addrlen);
2054 			return(1);
2055 		case IFT_ARCNET:
2056 			*desten = 0;
2057 			return(1);
2058 		default:
2059 			m_freem(m);
2060 			return(0);
2061 		}
2062 	}
2063 	if (rt0 == NULL) {
2064 		/* this could happen, if we could not allocate memory */
2065 		m_freem(m);
2066 		return(0);
2067 	}
2068 	if (rt_llroute(dst, rt0, &rt) != 0) {
2069 		m_freem(m);
2070 		return (0);
2071 	}
2072 	if (rt->rt_gateway->sa_family != AF_LINK) {
2073 		printf("nd6_storelladdr: something odd happens\n");
2074 		m_freem(m);
2075 		return(0);
2076 	}
2077 	sdl = SDL(rt->rt_gateway);
2078 	if (sdl->sdl_alen == 0) {
2079 		/* this should be impossible, but we bark here for debugging */
2080 		printf("nd6_storelladdr: sdl_alen == 0\n");
2081 		m_freem(m);
2082 		return(0);
2083 	}
2084 
2085 	bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
2086 	return(1);
2087 }
2088 
2089 static int nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS);
2090 static int nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS);
2091 #ifdef SYSCTL_DECL
2092 SYSCTL_DECL(_net_inet6_icmp6);
2093 #endif
2094 SYSCTL_NODE(_net_inet6_icmp6, ICMPV6CTL_ND6_DRLIST, nd6_drlist,
2095 	CTLFLAG_RD, nd6_sysctl_drlist, "");
2096 SYSCTL_NODE(_net_inet6_icmp6, ICMPV6CTL_ND6_PRLIST, nd6_prlist,
2097 	CTLFLAG_RD, nd6_sysctl_prlist, "");
2098 
2099 static int
2100 nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS)
2101 {
2102 	int error;
2103 	char buf[1024];
2104 	struct in6_defrouter *d, *de;
2105 	struct nd_defrouter *dr;
2106 
2107 	if (req->newptr)
2108 		return EPERM;
2109 	error = 0;
2110 
2111 	for (dr = TAILQ_FIRST(&nd_defrouter);
2112 	     dr;
2113 	     dr = TAILQ_NEXT(dr, dr_entry)) {
2114 		d = (struct in6_defrouter *)buf;
2115 		de = (struct in6_defrouter *)(buf + sizeof(buf));
2116 
2117 		if (d + 1 <= de) {
2118 			bzero(d, sizeof(*d));
2119 			d->rtaddr.sin6_family = AF_INET6;
2120 			d->rtaddr.sin6_len = sizeof(d->rtaddr);
2121 			if (in6_recoverscope(&d->rtaddr, &dr->rtaddr,
2122 			    dr->ifp) != 0)
2123 				log(LOG_ERR,
2124 				    "scope error in "
2125 				    "default router list (%s)\n",
2126 				    ip6_sprintf(&dr->rtaddr));
2127 			d->flags = dr->flags;
2128 			d->rtlifetime = dr->rtlifetime;
2129 			d->expire = dr->expire;
2130 			d->if_index = dr->ifp->if_index;
2131 		} else
2132 			panic("buffer too short");
2133 
2134 		error = SYSCTL_OUT(req, buf, sizeof(*d));
2135 		if (error)
2136 			break;
2137 	}
2138 	return error;
2139 }
2140 
2141 static int
2142 nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS)
2143 {
2144 	int error;
2145 	char buf[1024];
2146 	struct in6_prefix *p, *pe;
2147 	struct nd_prefix *pr;
2148 
2149 	if (req->newptr)
2150 		return EPERM;
2151 	error = 0;
2152 
2153 	for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
2154 		u_short advrtrs;
2155 		size_t advance;
2156 		struct sockaddr_in6 *sin6, *s6;
2157 		struct nd_pfxrouter *pfr;
2158 
2159 		p = (struct in6_prefix *)buf;
2160 		pe = (struct in6_prefix *)(buf + sizeof(buf));
2161 
2162 		if (p + 1 <= pe) {
2163 			bzero(p, sizeof(*p));
2164 			sin6 = (struct sockaddr_in6 *)(p + 1);
2165 
2166 			p->prefix = pr->ndpr_prefix;
2167 			if (in6_recoverscope(&p->prefix,
2168 			    &p->prefix.sin6_addr, pr->ndpr_ifp) != 0)
2169 				log(LOG_ERR,
2170 				    "scope error in prefix list (%s)\n",
2171 				    ip6_sprintf(&p->prefix.sin6_addr));
2172 			p->raflags = pr->ndpr_raf;
2173 			p->prefixlen = pr->ndpr_plen;
2174 			p->vltime = pr->ndpr_vltime;
2175 			p->pltime = pr->ndpr_pltime;
2176 			p->if_index = pr->ndpr_ifp->if_index;
2177 			p->expire = pr->ndpr_expire;
2178 			p->refcnt = pr->ndpr_refcnt;
2179 			p->flags = pr->ndpr_stateflags;
2180 			p->origin = PR_ORIG_RA;
2181 			advrtrs = 0;
2182 			for (pfr = pr->ndpr_advrtrs.lh_first;
2183 			     pfr;
2184 			     pfr = pfr->pfr_next) {
2185 				if ((void *)&sin6[advrtrs + 1] >
2186 				    (void *)pe) {
2187 					advrtrs++;
2188 					continue;
2189 				}
2190 				s6 = &sin6[advrtrs];
2191 				bzero(s6, sizeof(*s6));
2192 				s6->sin6_family = AF_INET6;
2193 				s6->sin6_len = sizeof(*sin6);
2194 				if (in6_recoverscope(s6,
2195 				    &pfr->router->rtaddr,
2196 				    pfr->router->ifp) != 0)
2197 					log(LOG_ERR,
2198 					    "scope error in "
2199 					    "prefix list (%s)\n",
2200 					    ip6_sprintf(&pfr->router->rtaddr));
2201 				advrtrs++;
2202 			}
2203 			p->advrtrs = advrtrs;
2204 		} else
2205 			panic("buffer too short");
2206 
2207 		advance = sizeof(*p) + sizeof(*sin6) * advrtrs;
2208 		error = SYSCTL_OUT(req, buf, advance);
2209 		if (error)
2210 			break;
2211 	}
2212 	return error;
2213 }
2214