xref: /dragonfly/sys/netinet6/nd6.c (revision 43b4d1bd)
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 1.9 2004/08/13 14:27:29 drhodus 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_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
147 	    nd6_slowtimo, NULL);
148 }
149 
150 void
151 nd6_ifattach(struct ifnet *ifp)
152 {
153 
154 	/*
155 	 * We have some arrays that should be indexed by if_index.
156 	 * since if_index will grow dynamically, they should grow too.
157 	 */
158 	if (nd_ifinfo == NULL || if_index >= nd_ifinfo_indexlim) {
159 		size_t n;
160 		caddr_t q;
161 
162 		while (if_index >= nd_ifinfo_indexlim)
163 			nd_ifinfo_indexlim <<= 1;
164 
165 		/* grow nd_ifinfo */
166 		n = nd_ifinfo_indexlim * sizeof(struct nd_ifinfo);
167 		q = (caddr_t)malloc(n, M_IP6NDP, M_WAITOK);
168 		bzero(q, n);
169 		if (nd_ifinfo) {
170 			bcopy((caddr_t)nd_ifinfo, q, n/2);
171 			free((caddr_t)nd_ifinfo, M_IP6NDP);
172 		}
173 		nd_ifinfo = (struct nd_ifinfo *)q;
174 	}
175 
176 #define ND nd_ifinfo[ifp->if_index]
177 
178 	/*
179 	 * Don't initialize if called twice.
180 	 * XXX: to detect this, we should choose a member that is never set
181 	 * before initialization of the ND structure itself.  We formaly used
182 	 * the linkmtu member, which was not suitable because it could be
183 	 * initialized via "ifconfig mtu".
184 	 */
185 	if (ND.basereachable)
186 		return;
187 
188 	ND.linkmtu = ifindex2ifnet[ifp->if_index]->if_mtu;
189 	ND.chlim = IPV6_DEFHLIM;
190 	ND.basereachable = REACHABLE_TIME;
191 	ND.reachable = ND_COMPUTE_RTIME(ND.basereachable);
192 	ND.retrans = RETRANS_TIMER;
193 	ND.receivedra = 0;
194 	ND.flags = ND6_IFF_PERFORMNUD;
195 	nd6_setmtu(ifp);
196 #undef ND
197 }
198 
199 /*
200  * Reset ND level link MTU. This function is called when the physical MTU
201  * changes, which means we might have to adjust the ND level MTU.
202  */
203 void
204 nd6_setmtu(struct ifnet *ifp)
205 {
206 	struct nd_ifinfo *ndi = &nd_ifinfo[ifp->if_index];
207 	u_long oldmaxmtu = ndi->maxmtu;
208 	u_long oldlinkmtu = ndi->linkmtu;
209 
210 	switch (ifp->if_type) {
211 	case IFT_ARCNET:	/* XXX MTU handling needs more work */
212 		ndi->maxmtu = MIN(60480, ifp->if_mtu);
213 		break;
214 	case IFT_ETHER:
215 		ndi->maxmtu = MIN(ETHERMTU, ifp->if_mtu);
216 		break;
217 	case IFT_FDDI:
218 		ndi->maxmtu = MIN(FDDIIPMTU, ifp->if_mtu);
219 		break;
220 	case IFT_ATM:
221 		ndi->maxmtu = MIN(ATMMTU, ifp->if_mtu);
222 		break;
223 	case IFT_IEEE1394:	/* XXX should be IEEE1394MTU(1500) */
224 		ndi->maxmtu = MIN(ETHERMTU, ifp->if_mtu);
225 		break;
226 #ifdef IFT_IEEE80211
227 	case IFT_IEEE80211:	/* XXX should be IEEE80211MTU(1500) */
228 		ndi->maxmtu = MIN(ETHERMTU, ifp->if_mtu);
229 		break;
230 #endif
231 	default:
232 		ndi->maxmtu = ifp->if_mtu;
233 		break;
234 	}
235 
236 	if (oldmaxmtu != ndi->maxmtu) {
237 		/*
238 		 * If the ND level MTU is not set yet, or if the maxmtu
239 		 * is reset to a smaller value than the ND level MTU,
240 		 * also reset the ND level MTU.
241 		 */
242 		if (ndi->linkmtu == 0 ||
243 		    ndi->maxmtu < ndi->linkmtu) {
244 			ndi->linkmtu = ndi->maxmtu;
245 			/* also adjust in6_maxmtu if necessary. */
246 			if (oldlinkmtu == 0) {
247 				/*
248 				 * XXX: the case analysis is grotty, but
249 				 * it is not efficient to call in6_setmaxmtu()
250 				 * here when we are during the initialization
251 				 * procedure.
252 				 */
253 				if (in6_maxmtu < ndi->linkmtu)
254 					in6_maxmtu = ndi->linkmtu;
255 			} else
256 				in6_setmaxmtu();
257 		}
258 	}
259 #undef MIN
260 }
261 
262 void
263 nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts)
264 {
265 	bzero(ndopts, sizeof(*ndopts));
266 	ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
267 	ndopts->nd_opts_last
268 		= (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len);
269 
270 	if (icmp6len == 0) {
271 		ndopts->nd_opts_done = 1;
272 		ndopts->nd_opts_search = NULL;
273 	}
274 }
275 
276 /*
277  * Take one ND option.
278  */
279 struct nd_opt_hdr *
280 nd6_option(union nd_opts *ndopts)
281 {
282 	struct nd_opt_hdr *nd_opt;
283 	int olen;
284 
285 	if (!ndopts)
286 		panic("ndopts == NULL in nd6_option");
287 	if (!ndopts->nd_opts_last)
288 		panic("uninitialized ndopts in nd6_option");
289 	if (!ndopts->nd_opts_search)
290 		return NULL;
291 	if (ndopts->nd_opts_done)
292 		return NULL;
293 
294 	nd_opt = ndopts->nd_opts_search;
295 
296 	/* make sure nd_opt_len is inside the buffer */
297 	if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) {
298 		bzero(ndopts, sizeof(*ndopts));
299 		return NULL;
300 	}
301 
302 	olen = nd_opt->nd_opt_len << 3;
303 	if (olen == 0) {
304 		/*
305 		 * Message validation requires that all included
306 		 * options have a length that is greater than zero.
307 		 */
308 		bzero(ndopts, sizeof(*ndopts));
309 		return NULL;
310 	}
311 
312 	ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen);
313 	if (ndopts->nd_opts_search > ndopts->nd_opts_last) {
314 		/* option overruns the end of buffer, invalid */
315 		bzero(ndopts, sizeof(*ndopts));
316 		return NULL;
317 	} else if (ndopts->nd_opts_search == ndopts->nd_opts_last) {
318 		/* reached the end of options chain */
319 		ndopts->nd_opts_done = 1;
320 		ndopts->nd_opts_search = NULL;
321 	}
322 	return nd_opt;
323 }
324 
325 /*
326  * Parse multiple ND options.
327  * This function is much easier to use, for ND routines that do not need
328  * multiple options of the same type.
329  */
330 int
331 nd6_options(union nd_opts *ndopts)
332 {
333 	struct nd_opt_hdr *nd_opt;
334 	int i = 0;
335 
336 	if (!ndopts)
337 		panic("ndopts == NULL in nd6_options");
338 	if (!ndopts->nd_opts_last)
339 		panic("uninitialized ndopts in nd6_options");
340 	if (!ndopts->nd_opts_search)
341 		return 0;
342 
343 	while (1) {
344 		nd_opt = nd6_option(ndopts);
345 		if (!nd_opt && !ndopts->nd_opts_last) {
346 			/*
347 			 * Message validation requires that all included
348 			 * options have a length that is greater than zero.
349 			 */
350 			icmp6stat.icp6s_nd_badopt++;
351 			bzero(ndopts, sizeof(*ndopts));
352 			return -1;
353 		}
354 
355 		if (!nd_opt)
356 			goto skip1;
357 
358 		switch (nd_opt->nd_opt_type) {
359 		case ND_OPT_SOURCE_LINKADDR:
360 		case ND_OPT_TARGET_LINKADDR:
361 		case ND_OPT_MTU:
362 		case ND_OPT_REDIRECTED_HEADER:
363 			if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
364 				nd6log((LOG_INFO,
365 				    "duplicated ND6 option found (type=%d)\n",
366 				    nd_opt->nd_opt_type));
367 				/* XXX bark? */
368 			} else {
369 				ndopts->nd_opt_array[nd_opt->nd_opt_type]
370 					= nd_opt;
371 			}
372 			break;
373 		case ND_OPT_PREFIX_INFORMATION:
374 			if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
375 				ndopts->nd_opt_array[nd_opt->nd_opt_type]
376 					= nd_opt;
377 			}
378 			ndopts->nd_opts_pi_end =
379 				(struct nd_opt_prefix_info *)nd_opt;
380 			break;
381 		default:
382 			/*
383 			 * Unknown options must be silently ignored,
384 			 * to accomodate future extension to the protocol.
385 			 */
386 			nd6log((LOG_DEBUG,
387 			    "nd6_options: unsupported option %d - "
388 			    "option ignored\n", nd_opt->nd_opt_type));
389 		}
390 
391 skip1:
392 		i++;
393 		if (i > nd6_maxndopt) {
394 			icmp6stat.icp6s_nd_toomanyopt++;
395 			nd6log((LOG_INFO, "too many loop in nd opt\n"));
396 			break;
397 		}
398 
399 		if (ndopts->nd_opts_done)
400 			break;
401 	}
402 
403 	return 0;
404 }
405 
406 /*
407  * ND6 timer routine to expire default route list and prefix list
408  */
409 void
410 nd6_timer(void *ignored_arg)
411 {
412 	int s;
413 	struct llinfo_nd6 *ln;
414 	struct nd_defrouter *dr;
415 	struct nd_prefix *pr;
416 	struct ifnet *ifp;
417 	struct in6_ifaddr *ia6, *nia6;
418 	struct in6_addrlifetime *lt6;
419 
420 	s = splnet();
421 	callout_reset(&nd6_timer_ch, nd6_prune * hz,
422 		      nd6_timer, NULL);
423 
424 	ln = llinfo_nd6.ln_next;
425 	while (ln && ln != &llinfo_nd6) {
426 		struct rtentry *rt;
427 		struct sockaddr_in6 *dst;
428 		struct llinfo_nd6 *next = ln->ln_next;
429 		/* XXX: used for the DELAY case only: */
430 		struct nd_ifinfo *ndi = NULL;
431 
432 		if ((rt = ln->ln_rt) == NULL) {
433 			ln = next;
434 			continue;
435 		}
436 		if ((ifp = rt->rt_ifp) == NULL) {
437 			ln = next;
438 			continue;
439 		}
440 		ndi = &nd_ifinfo[ifp->if_index];
441 		dst = (struct sockaddr_in6 *)rt_key(rt);
442 
443 		if (ln->ln_expire > time_second) {
444 			ln = next;
445 			continue;
446 		}
447 
448 		/* sanity check */
449 		if (!rt)
450 			panic("rt=0 in nd6_timer(ln=%p)", ln);
451 		if (rt->rt_llinfo && (struct llinfo_nd6 *)rt->rt_llinfo != ln)
452 			panic("rt_llinfo(%p) is not equal to ln(%p)",
453 			      rt->rt_llinfo, ln);
454 		if (!dst)
455 			panic("dst=0 in nd6_timer(ln=%p)", ln);
456 
457 		switch (ln->ln_state) {
458 		case ND6_LLINFO_INCOMPLETE:
459 			if (ln->ln_asked < nd6_mmaxtries) {
460 				ln->ln_asked++;
461 				ln->ln_expire = time_second +
462 					nd_ifinfo[ifp->if_index].retrans / 1000;
463 				nd6_ns_output(ifp, NULL, &dst->sin6_addr,
464 					ln, 0);
465 			} else {
466 				struct mbuf *m = ln->ln_hold;
467 				if (m) {
468 					if (rt->rt_ifp) {
469 						/*
470 						 * Fake rcvif to make ICMP error
471 						 * more helpful in diagnosing
472 						 * for the receiver.
473 						 * XXX: should we consider
474 						 * older rcvif?
475 						 */
476 						m->m_pkthdr.rcvif = rt->rt_ifp;
477 					}
478 					icmp6_error(m, ICMP6_DST_UNREACH,
479 						    ICMP6_DST_UNREACH_ADDR, 0);
480 					ln->ln_hold = NULL;
481 				}
482 				next = nd6_free(rt);
483 			}
484 			break;
485 		case ND6_LLINFO_REACHABLE:
486 			if (ln->ln_expire) {
487 				ln->ln_state = ND6_LLINFO_STALE;
488 				ln->ln_expire = time_second + nd6_gctimer;
489 			}
490 			break;
491 
492 		case ND6_LLINFO_STALE:
493 			/* Garbage Collection(RFC 2461 5.3) */
494 			if (ln->ln_expire)
495 				next = nd6_free(rt);
496 			break;
497 
498 		case ND6_LLINFO_DELAY:
499 			if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) {
500 				/* We need NUD */
501 				ln->ln_asked = 1;
502 				ln->ln_state = ND6_LLINFO_PROBE;
503 				ln->ln_expire = time_second +
504 					ndi->retrans / 1000;
505 				nd6_ns_output(ifp, &dst->sin6_addr,
506 					      &dst->sin6_addr,
507 					      ln, 0);
508 			} else {
509 				ln->ln_state = ND6_LLINFO_STALE; /* XXX */
510 				ln->ln_expire = time_second + nd6_gctimer;
511 			}
512 			break;
513 		case ND6_LLINFO_PROBE:
514 			if (ln->ln_asked < nd6_umaxtries) {
515 				ln->ln_asked++;
516 				ln->ln_expire = time_second +
517 					nd_ifinfo[ifp->if_index].retrans / 1000;
518 				nd6_ns_output(ifp, &dst->sin6_addr,
519 					       &dst->sin6_addr, ln, 0);
520 			} else {
521 				next = nd6_free(rt);
522 			}
523 			break;
524 		}
525 		ln = next;
526 	}
527 
528 	/* expire default router list */
529 	dr = TAILQ_FIRST(&nd_defrouter);
530 	while (dr) {
531 		if (dr->expire && dr->expire < time_second) {
532 			struct nd_defrouter *t;
533 			t = TAILQ_NEXT(dr, dr_entry);
534 			defrtrlist_del(dr);
535 			dr = t;
536 		} else {
537 			dr = TAILQ_NEXT(dr, dr_entry);
538 		}
539 	}
540 
541 	/*
542 	 * expire interface addresses.
543 	 * in the past the loop was inside prefix expiry processing.
544 	 * However, from a stricter speci-confrmance standpoint, we should
545 	 * rather separate address lifetimes and prefix lifetimes.
546 	 */
547   addrloop:
548 	for (ia6 = in6_ifaddr; ia6; ia6 = nia6) {
549 		nia6 = ia6->ia_next;
550 		/* check address lifetime */
551 		lt6 = &ia6->ia6_lifetime;
552 		if (IFA6_IS_INVALID(ia6)) {
553 			int regen = 0;
554 
555 			/*
556 			 * If the expiring address is temporary, try
557 			 * regenerating a new one.  This would be useful when
558 			 * we suspended a laptop PC, then turned it on after a
559 			 * period that could invalidate all temporary
560 			 * addresses.  Although we may have to restart the
561 			 * loop (see below), it must be after purging the
562 			 * address.  Otherwise, we'd see an infinite loop of
563 			 * regeneration.
564 			 */
565 			if (ip6_use_tempaddr &&
566 			    (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
567 				if (regen_tmpaddr(ia6) == 0)
568 					regen = 1;
569 			}
570 
571 			in6_purgeaddr(&ia6->ia_ifa);
572 
573 			if (regen)
574 				goto addrloop; /* XXX: see below */
575 		}
576 		if (IFA6_IS_DEPRECATED(ia6)) {
577 			int oldflags = ia6->ia6_flags;
578 
579 			ia6->ia6_flags |= IN6_IFF_DEPRECATED;
580 
581 			/*
582 			 * If a temporary address has just become deprecated,
583 			 * regenerate a new one if possible.
584 			 */
585 			if (ip6_use_tempaddr &&
586 			    (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
587 			    (oldflags & IN6_IFF_DEPRECATED) == 0) {
588 
589 				if (regen_tmpaddr(ia6) == 0) {
590 					/*
591 					 * A new temporary address is
592 					 * generated.
593 					 * XXX: this means the address chain
594 					 * has changed while we are still in
595 					 * the loop.  Although the change
596 					 * would not cause disaster (because
597 					 * it's not a deletion, but an
598 					 * addition,) we'd rather restart the
599 					 * loop just for safety.  Or does this
600 					 * significantly reduce performance??
601 					 */
602 					goto addrloop;
603 				}
604 			}
605 		} else {
606 			/*
607 			 * A new RA might have made a deprecated address
608 			 * preferred.
609 			 */
610 			ia6->ia6_flags &= ~IN6_IFF_DEPRECATED;
611 		}
612 	}
613 
614 	/* expire prefix list */
615 	pr = nd_prefix.lh_first;
616 	while (pr) {
617 		/*
618 		 * check prefix lifetime.
619 		 * since pltime is just for autoconf, pltime processing for
620 		 * prefix is not necessary.
621 		 */
622 		if (pr->ndpr_expire && pr->ndpr_expire < time_second) {
623 			struct nd_prefix *t;
624 			t = pr->ndpr_next;
625 
626 			/*
627 			 * address expiration and prefix expiration are
628 			 * separate.  NEVER perform in6_purgeaddr here.
629 			 */
630 
631 			prelist_remove(pr);
632 			pr = t;
633 		} else
634 			pr = pr->ndpr_next;
635 	}
636 	splx(s);
637 }
638 
639 static int
640 regen_tmpaddr(struct in6_ifaddr *ia6) /* deprecated/invalidated temporary
641 					 address */
642 {
643 	struct ifaddr *ifa;
644 	struct ifnet *ifp;
645 	struct in6_ifaddr *public_ifa6 = NULL;
646 
647 	ifp = ia6->ia_ifa.ifa_ifp;
648 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_list) {
649 		struct in6_ifaddr *it6;
650 
651 		if (ifa->ifa_addr->sa_family != AF_INET6)
652 			continue;
653 
654 		it6 = (struct in6_ifaddr *)ifa;
655 
656 		/* ignore no autoconf addresses. */
657 		if ((it6->ia6_flags & IN6_IFF_AUTOCONF) == 0)
658 			continue;
659 
660 		/* ignore autoconf addresses with different prefixes. */
661 		if (it6->ia6_ndpr == NULL || it6->ia6_ndpr != ia6->ia6_ndpr)
662 			continue;
663 
664 		/*
665 		 * Now we are looking at an autoconf address with the same
666 		 * prefix as ours.  If the address is temporary and is still
667 		 * preferred, do not create another one.  It would be rare, but
668 		 * could happen, for example, when we resume a laptop PC after
669 		 * a long period.
670 		 */
671 		if ((it6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
672 		    !IFA6_IS_DEPRECATED(it6)) {
673 			public_ifa6 = NULL;
674 			break;
675 		}
676 
677 		/*
678 		 * This is a public autoconf address that has the same prefix
679 		 * as ours.  If it is preferred, keep it.  We can't break the
680 		 * loop here, because there may be a still-preferred temporary
681 		 * address with the prefix.
682 		 */
683 		if (!IFA6_IS_DEPRECATED(it6))
684 		    public_ifa6 = it6;
685 	}
686 
687 	if (public_ifa6 != NULL) {
688 		int e;
689 
690 		if ((e = in6_tmpifadd(public_ifa6, 0)) != 0) {
691 			log(LOG_NOTICE, "regen_tmpaddr: failed to create a new"
692 			    " tmp addr,errno=%d\n", e);
693 			return(-1);
694 		}
695 		return(0);
696 	}
697 
698 	return(-1);
699 }
700 
701 /*
702  * Nuke neighbor cache/prefix/default router management table, right before
703  * ifp goes away.
704  */
705 void
706 nd6_purge(struct ifnet *ifp)
707 {
708 	struct llinfo_nd6 *ln, *nln;
709 	struct nd_defrouter *dr, *ndr, drany;
710 	struct nd_prefix *pr, *npr;
711 
712 	/* Nuke default router list entries toward ifp */
713 	if ((dr = TAILQ_FIRST(&nd_defrouter)) != NULL) {
714 		/*
715 		 * The first entry of the list may be stored in
716 		 * the routing table, so we'll delete it later.
717 		 */
718 		for (dr = TAILQ_NEXT(dr, dr_entry); dr; dr = ndr) {
719 			ndr = TAILQ_NEXT(dr, dr_entry);
720 			if (dr->ifp == ifp)
721 				defrtrlist_del(dr);
722 		}
723 		dr = TAILQ_FIRST(&nd_defrouter);
724 		if (dr->ifp == ifp)
725 			defrtrlist_del(dr);
726 	}
727 
728 	/* Nuke prefix list entries toward ifp */
729 	for (pr = nd_prefix.lh_first; pr; pr = npr) {
730 		npr = pr->ndpr_next;
731 		if (pr->ndpr_ifp == ifp) {
732 			/*
733 			 * Previously, pr->ndpr_addr is removed as well,
734 			 * but I strongly believe we don't have to do it.
735 			 * nd6_purge() is only called from in6_ifdetach(),
736 			 * which removes all the associated interface addresses
737 			 * by itself.
738 			 * (jinmei@kame.net 20010129)
739 			 */
740 			prelist_remove(pr);
741 		}
742 	}
743 
744 	/* cancel default outgoing interface setting */
745 	if (nd6_defifindex == ifp->if_index)
746 		nd6_setdefaultiface(0);
747 
748 	if (!ip6_forwarding && ip6_accept_rtadv) { /* XXX: too restrictive? */
749 		/* refresh default router list */
750 		bzero(&drany, sizeof(drany));
751 		defrouter_delreq(&drany, 0);
752 		defrouter_select();
753 	}
754 
755 	/*
756 	 * Nuke neighbor cache entries for the ifp.
757 	 * Note that rt->rt_ifp may not be the same as ifp,
758 	 * due to KAME goto ours hack.  See RTM_RESOLVE case in
759 	 * nd6_rtrequest(), and ip6_input().
760 	 */
761 	ln = llinfo_nd6.ln_next;
762 	while (ln && ln != &llinfo_nd6) {
763 		struct rtentry *rt;
764 		struct sockaddr_dl *sdl;
765 
766 		nln = ln->ln_next;
767 		rt = ln->ln_rt;
768 		if (rt && rt->rt_gateway &&
769 		    rt->rt_gateway->sa_family == AF_LINK) {
770 			sdl = (struct sockaddr_dl *)rt->rt_gateway;
771 			if (sdl->sdl_index == ifp->if_index)
772 				nln = nd6_free(rt);
773 		}
774 		ln = nln;
775 	}
776 }
777 
778 struct rtentry *
779 nd6_lookup(struct in6_addr *addr6, int create, struct ifnet *ifp)
780 {
781 	struct rtentry *rt;
782 	struct sockaddr_in6 sin6;
783 
784 	bzero(&sin6, sizeof(sin6));
785 	sin6.sin6_len = sizeof(struct sockaddr_in6);
786 	sin6.sin6_family = AF_INET6;
787 	sin6.sin6_addr = *addr6;
788 #ifdef SCOPEDROUTING
789 	sin6.sin6_scope_id = in6_addr2scopeid(ifp, addr6);
790 #endif
791 	rt = rtalloc1((struct sockaddr *)&sin6, create, 0UL);
792 	if (rt && (rt->rt_flags & RTF_LLINFO) == 0) {
793 		/*
794 		 * This is the case for the default route.
795 		 * If we want to create a neighbor cache for the address, we
796 		 * should free the route for the destination and allocate an
797 		 * interface route.
798 		 */
799 		if (create) {
800 			RTFREE(rt);
801 			rt = 0;
802 		}
803 	}
804 	if (!rt) {
805 		if (create && ifp) {
806 			int e;
807 
808 			/*
809 			 * If no route is available and create is set,
810 			 * we allocate a host route for the destination
811 			 * and treat it like an interface route.
812 			 * This hack is necessary for a neighbor which can't
813 			 * be covered by our own prefix.
814 			 */
815 			struct ifaddr *ifa =
816 				ifaof_ifpforaddr((struct sockaddr *)&sin6, ifp);
817 			if (ifa == NULL)
818 				return(NULL);
819 
820 			/*
821 			 * Create a new route.  RTF_LLINFO is necessary
822 			 * to create a Neighbor Cache entry for the
823 			 * destination in nd6_rtrequest which will be
824 			 * called in rtrequest via ifa->ifa_rtrequest.
825 			 */
826 			if ((e = rtrequest(RTM_ADD, (struct sockaddr *)&sin6,
827 					   ifa->ifa_addr,
828 					   (struct sockaddr *)&all1_sa,
829 					   (ifa->ifa_flags |
830 					    RTF_HOST | RTF_LLINFO) &
831 					   ~RTF_CLONING,
832 					   &rt)) != 0)
833 				log(LOG_ERR,
834 				    "nd6_lookup: failed to add route for a "
835 				    "neighbor(%s), errno=%d\n",
836 				    ip6_sprintf(addr6), e);
837 			if (rt == NULL)
838 				return(NULL);
839 			if (rt->rt_llinfo) {
840 				struct llinfo_nd6 *ln =
841 					(struct llinfo_nd6 *)rt->rt_llinfo;
842 				ln->ln_state = ND6_LLINFO_NOSTATE;
843 			}
844 		} else
845 			return(NULL);
846 	}
847 	rt->rt_refcnt--;
848 	/*
849 	 * Validation for the entry.
850 	 * Note that the check for rt_llinfo is necessary because a cloned
851 	 * route from a parent route that has the L flag (e.g. the default
852 	 * route to a p2p interface) may have the flag, too, while the
853 	 * destination is not actually a neighbor.
854 	 * XXX: we can't use rt->rt_ifp to check for the interface, since
855 	 *      it might be the loopback interface if the entry is for our
856 	 *      own address on a non-loopback interface. Instead, we should
857 	 *      use rt->rt_ifa->ifa_ifp, which would specify the REAL
858 	 *      interface.
859 	 */
860 	if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 ||
861 	    rt->rt_gateway->sa_family != AF_LINK || rt->rt_llinfo == NULL ||
862 	    (ifp && rt->rt_ifa->ifa_ifp != ifp)) {
863 		if (create) {
864 			log(LOG_DEBUG, "nd6_lookup: failed to lookup %s (if = %s)\n",
865 			    ip6_sprintf(addr6), ifp ? if_name(ifp) : "unspec");
866 			/* xxx more logs... kazu */
867 		}
868 		return(NULL);
869 	}
870 	return(rt);
871 }
872 
873 /*
874  * Detect if a given IPv6 address identifies a neighbor on a given link.
875  * XXX: should take care of the destination of a p2p link?
876  */
877 int
878 nd6_is_addr_neighbor(struct sockaddr_in6 *addr, struct ifnet *ifp)
879 {
880 	struct ifaddr *ifa;
881 	int i;
882 
883 #define IFADDR6(a) ((((struct in6_ifaddr *)(a))->ia_addr).sin6_addr)
884 #define IFMASK6(a) ((((struct in6_ifaddr *)(a))->ia_prefixmask).sin6_addr)
885 
886 	/*
887 	 * A link-local address is always a neighbor.
888 	 * XXX: we should use the sin6_scope_id field rather than the embedded
889 	 * interface index.
890 	 */
891 	if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr) &&
892 	    ntohs(*(u_int16_t *)&addr->sin6_addr.s6_addr[2]) == ifp->if_index)
893 		return(1);
894 
895 	/*
896 	 * If the address matches one of our addresses,
897 	 * it should be a neighbor.
898 	 */
899 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
900 		if (ifa->ifa_addr->sa_family != AF_INET6)
901 			next: continue;
902 
903 		for (i = 0; i < 4; i++) {
904 			if ((IFADDR6(ifa).s6_addr32[i] ^
905 			     addr->sin6_addr.s6_addr32[i]) &
906 			    IFMASK6(ifa).s6_addr32[i])
907 				goto next;
908 		}
909 		return(1);
910 	}
911 
912 	/*
913 	 * Even if the address matches none of our addresses, it might be
914 	 * in the neighbor cache.
915 	 */
916 	if (nd6_lookup(&addr->sin6_addr, 0, ifp) != NULL)
917 		return(1);
918 
919 	return(0);
920 #undef IFADDR6
921 #undef IFMASK6
922 }
923 
924 /*
925  * Free an nd6 llinfo entry.
926  */
927 struct llinfo_nd6 *
928 nd6_free(struct rtentry *rt)
929 {
930 	struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo, *next;
931 	struct in6_addr in6 = ((struct sockaddr_in6 *)rt_key(rt))->sin6_addr;
932 	struct nd_defrouter *dr;
933 
934 	/*
935 	 * we used to have pfctlinput(PRC_HOSTDEAD) here.
936 	 * even though it is not harmful, it was not really necessary.
937 	 */
938 
939 	if (!ip6_forwarding && ip6_accept_rtadv) { /* XXX: too restrictive? */
940 		int s;
941 		s = splnet();
942 		dr = defrouter_lookup(&((struct sockaddr_in6 *)rt_key(rt))->sin6_addr,
943 				      rt->rt_ifp);
944 
945 		if (ln->ln_router || dr) {
946 			/*
947 			 * rt6_flush must be called whether or not the neighbor
948 			 * is in the Default Router List.
949 			 * See a corresponding comment in nd6_na_input().
950 			 */
951 			rt6_flush(&in6, rt->rt_ifp);
952 		}
953 
954 		if (dr) {
955 			/*
956 			 * Unreachablity of a router might affect the default
957 			 * router selection and on-link detection of advertised
958 			 * prefixes.
959 			 */
960 
961 			/*
962 			 * Temporarily fake the state to choose a new default
963 			 * router and to perform on-link determination of
964 			 * prefixes correctly.
965 			 * Below the state will be set correctly,
966 			 * or the entry itself will be deleted.
967 			 */
968 			ln->ln_state = ND6_LLINFO_INCOMPLETE;
969 
970 			/*
971 			 * Since defrouter_select() does not affect the
972 			 * on-link determination and MIP6 needs the check
973 			 * before the default router selection, we perform
974 			 * the check now.
975 			 */
976 			pfxlist_onlink_check();
977 
978 			if (dr == TAILQ_FIRST(&nd_defrouter)) {
979 				/*
980 				 * It is used as the current default router,
981 				 * so we have to move it to the end of the
982 				 * list and choose a new one.
983 				 * XXX: it is not very efficient if this is
984 				 *      the only router.
985 				 */
986 				TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
987 				TAILQ_INSERT_TAIL(&nd_defrouter, dr, dr_entry);
988 
989 				defrouter_select();
990 			}
991 		}
992 		splx(s);
993 	}
994 
995 	/*
996 	 * Before deleting the entry, remember the next entry as the
997 	 * return value.  We need this because pfxlist_onlink_check() above
998 	 * might have freed other entries (particularly the old next entry) as
999 	 * a side effect (XXX).
1000 	 */
1001 	next = ln->ln_next;
1002 
1003 	/*
1004 	 * Detach the route from the routing tree and the list of neighbor
1005 	 * caches, and disable the route entry not to be used in already
1006 	 * cached routes.
1007 	 */
1008 	rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0,
1009 		  rt_mask(rt), 0, (struct rtentry **)0);
1010 
1011 	return(next);
1012 }
1013 
1014 /*
1015  * Upper-layer reachability hint for Neighbor Unreachability Detection.
1016  *
1017  * XXX cost-effective metods?
1018  */
1019 void
1020 nd6_nud_hint(struct rtentry *rt, struct in6_addr *dst6, int force)
1021 {
1022 	struct llinfo_nd6 *ln;
1023 
1024 	/*
1025 	 * If the caller specified "rt", use that.  Otherwise, resolve the
1026 	 * routing table by supplied "dst6".
1027 	 */
1028 	if (!rt) {
1029 		if (!dst6)
1030 			return;
1031 		if (!(rt = nd6_lookup(dst6, 0, NULL)))
1032 			return;
1033 	}
1034 
1035 	if ((rt->rt_flags & RTF_GATEWAY) != 0 ||
1036 	    (rt->rt_flags & RTF_LLINFO) == 0 ||
1037 	    !rt->rt_llinfo || !rt->rt_gateway ||
1038 	    rt->rt_gateway->sa_family != AF_LINK) {
1039 		/* This is not a host route. */
1040 		return;
1041 	}
1042 
1043 	ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1044 	if (ln->ln_state < ND6_LLINFO_REACHABLE)
1045 		return;
1046 
1047 	/*
1048 	 * if we get upper-layer reachability confirmation many times,
1049 	 * it is possible we have false information.
1050 	 */
1051 	if (!force) {
1052 		ln->ln_byhint++;
1053 		if (ln->ln_byhint > nd6_maxnudhint)
1054 			return;
1055 	}
1056 
1057 	ln->ln_state = ND6_LLINFO_REACHABLE;
1058 	if (ln->ln_expire)
1059 		ln->ln_expire = time_second +
1060 			nd_ifinfo[rt->rt_ifp->if_index].reachable;
1061 }
1062 
1063 void
1064 nd6_rtrequest(int req, struct rtentry *rt,
1065 	      struct rt_addrinfo *info) /* xxx unused */
1066 {
1067 	struct sockaddr *gate = rt->rt_gateway;
1068 	struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1069 	static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
1070 	struct ifnet *ifp = rt->rt_ifp;
1071 	struct ifaddr *ifa;
1072 
1073 	if ((rt->rt_flags & RTF_GATEWAY))
1074 		return;
1075 
1076 	if (nd6_need_cache(ifp) == 0 && (rt->rt_flags & RTF_HOST) == 0) {
1077 		/*
1078 		 * This is probably an interface direct route for a link
1079 		 * which does not need neighbor caches (e.g. fe80::%lo0/64).
1080 		 * We do not need special treatment below for such a route.
1081 		 * Moreover, the RTF_LLINFO flag which would be set below
1082 		 * would annoy the ndp(8) command.
1083 		 */
1084 		return;
1085 	}
1086 
1087 	if (req == RTM_RESOLVE &&
1088 	    (nd6_need_cache(ifp) == 0 || /* stf case */
1089 	     !nd6_is_addr_neighbor((struct sockaddr_in6 *)rt_key(rt), ifp))) {
1090 		/*
1091 		 * FreeBSD and BSD/OS often make a cloned host route based
1092 		 * on a less-specific route (e.g. the default route).
1093 		 * If the less specific route does not have a "gateway"
1094 		 * (this is the case when the route just goes to a p2p or an
1095 		 * stf interface), we'll mistakenly make a neighbor cache for
1096 		 * the host route, and will see strange neighbor solicitation
1097 		 * for the corresponding destination.  In order to avoid the
1098 		 * confusion, we check if the destination of the route is
1099 		 * a neighbor in terms of neighbor discovery, and stop the
1100 		 * process if not.  Additionally, we remove the LLINFO flag
1101 		 * so that ndp(8) will not try to get the neighbor information
1102 		 * of the destination.
1103 		 */
1104 		rt->rt_flags &= ~RTF_LLINFO;
1105 		return;
1106 	}
1107 
1108 	switch (req) {
1109 	case RTM_ADD:
1110 		/*
1111 		 * There is no backward compatibility :)
1112 		 *
1113 		 * if ((rt->rt_flags & RTF_HOST) == 0 &&
1114 		 *     SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff)
1115 		 *	   rt->rt_flags |= RTF_CLONING;
1116 		 */
1117 		if (rt->rt_flags & (RTF_CLONING | RTF_LLINFO)) {
1118 			/*
1119 			 * Case 1: This route should come from
1120 			 * a route to interface.  RTF_LLINFO flag is set
1121 			 * for a host route whose destination should be
1122 			 * treated as on-link.
1123 			 */
1124 			rt_setgate(rt, rt_key(rt),
1125 				   (struct sockaddr *)&null_sdl);
1126 			gate = rt->rt_gateway;
1127 			SDL(gate)->sdl_type = ifp->if_type;
1128 			SDL(gate)->sdl_index = ifp->if_index;
1129 			if (ln)
1130 				ln->ln_expire = time_second;
1131 #if 1
1132 			if (ln && ln->ln_expire == 0) {
1133 				/* kludge for desktops */
1134 #if 0
1135 				printf("nd6_rtequest: time.tv_sec is zero; "
1136 				       "treat it as 1\n");
1137 #endif
1138 				ln->ln_expire = 1;
1139 			}
1140 #endif
1141 			if ((rt->rt_flags & RTF_CLONING))
1142 				break;
1143 		}
1144 		/*
1145 		 * In IPv4 code, we try to annonuce new RTF_ANNOUNCE entry here.
1146 		 * We don't do that here since llinfo is not ready yet.
1147 		 *
1148 		 * There are also couple of other things to be discussed:
1149 		 * - unsolicited NA code needs improvement beforehand
1150 		 * - RFC2461 says we MAY send multicast unsolicited NA
1151 		 *   (7.2.6 paragraph 4), however, it also says that we
1152 		 *   SHOULD provide a mechanism to prevent multicast NA storm.
1153 		 *   we don't have anything like it right now.
1154 		 *   note that the mechanism needs a mutual agreement
1155 		 *   between proxies, which means that we need to implement
1156 		 *   a new protocol, or a new kludge.
1157 		 * - from RFC2461 6.2.4, host MUST NOT send an unsolicited NA.
1158 		 *   we need to check ip6forwarding before sending it.
1159 		 *   (or should we allow proxy ND configuration only for
1160 		 *   routers?  there's no mention about proxy ND from hosts)
1161 		 */
1162 #if 0
1163 		/* XXX it does not work */
1164 		if (rt->rt_flags & RTF_ANNOUNCE)
1165 			nd6_na_output(ifp,
1166 			      &SIN6(rt_key(rt))->sin6_addr,
1167 			      &SIN6(rt_key(rt))->sin6_addr,
1168 			      ip6_forwarding ? ND_NA_FLAG_ROUTER : 0,
1169 			      1, NULL);
1170 #endif
1171 		/* FALLTHROUGH */
1172 	case RTM_RESOLVE:
1173 		if ((ifp->if_flags & (IFF_POINTOPOINT | IFF_LOOPBACK)) == 0) {
1174 			/*
1175 			 * Address resolution isn't necessary for a point to
1176 			 * point link, so we can skip this test for a p2p link.
1177 			 */
1178 			if (gate->sa_family != AF_LINK ||
1179 			    gate->sa_len < sizeof(null_sdl)) {
1180 				log(LOG_DEBUG,
1181 				    "nd6_rtrequest: bad gateway value: %s\n",
1182 				    if_name(ifp));
1183 				break;
1184 			}
1185 			SDL(gate)->sdl_type = ifp->if_type;
1186 			SDL(gate)->sdl_index = ifp->if_index;
1187 		}
1188 		if (ln != NULL)
1189 			break;	/* This happens on a route change */
1190 		/*
1191 		 * Case 2: This route may come from cloning, or a manual route
1192 		 * add with a LL address.
1193 		 */
1194 		R_Malloc(ln, struct llinfo_nd6 *, sizeof(*ln));
1195 		rt->rt_llinfo = (caddr_t)ln;
1196 		if (!ln) {
1197 			log(LOG_DEBUG, "nd6_rtrequest: malloc failed\n");
1198 			break;
1199 		}
1200 		nd6_inuse++;
1201 		nd6_allocated++;
1202 		Bzero(ln, sizeof(*ln));
1203 		ln->ln_rt = rt;
1204 		/* this is required for "ndp" command. - shin */
1205 		if (req == RTM_ADD) {
1206 		        /*
1207 			 * gate should have some valid AF_LINK entry,
1208 			 * and ln->ln_expire should have some lifetime
1209 			 * which is specified by ndp command.
1210 			 */
1211 			ln->ln_state = ND6_LLINFO_REACHABLE;
1212 			ln->ln_byhint = 0;
1213 		} else {
1214 		        /*
1215 			 * When req == RTM_RESOLVE, rt is created and
1216 			 * initialized in rtrequest(), so rt_expire is 0.
1217 			 */
1218 			ln->ln_state = ND6_LLINFO_NOSTATE;
1219 			ln->ln_expire = time_second;
1220 		}
1221 		rt->rt_flags |= RTF_LLINFO;
1222 		ln->ln_next = llinfo_nd6.ln_next;
1223 		llinfo_nd6.ln_next = ln;
1224 		ln->ln_prev = &llinfo_nd6;
1225 		ln->ln_next->ln_prev = ln;
1226 
1227 		/*
1228 		 * check if rt_key(rt) is one of my address assigned
1229 		 * to the interface.
1230 		 */
1231 		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(rt->rt_ifp,
1232 					  &SIN6(rt_key(rt))->sin6_addr);
1233 		if (ifa) {
1234 			caddr_t macp = nd6_ifptomac(ifp);
1235 			ln->ln_expire = 0;
1236 			ln->ln_state = ND6_LLINFO_REACHABLE;
1237 			ln->ln_byhint = 0;
1238 			if (macp) {
1239 				Bcopy(macp, LLADDR(SDL(gate)), ifp->if_addrlen);
1240 				SDL(gate)->sdl_alen = ifp->if_addrlen;
1241 			}
1242 			if (nd6_useloopback) {
1243 				rt->rt_ifp = &loif[0];	/* XXX */
1244 				/*
1245 				 * Make sure rt_ifa be equal to the ifaddr
1246 				 * corresponding to the address.
1247 				 * We need this because when we refer
1248 				 * rt_ifa->ia6_flags in ip6_input, we assume
1249 				 * that the rt_ifa points to the address instead
1250 				 * of the loopback address.
1251 				 */
1252 				if (ifa != rt->rt_ifa) {
1253 					IFAFREE(rt->rt_ifa);
1254 					IFAREF(ifa);
1255 					rt->rt_ifa = ifa;
1256 				}
1257 			}
1258 		} else if (rt->rt_flags & RTF_ANNOUNCE) {
1259 			ln->ln_expire = 0;
1260 			ln->ln_state = ND6_LLINFO_REACHABLE;
1261 			ln->ln_byhint = 0;
1262 
1263 			/* join solicited node multicast for proxy ND */
1264 			if (ifp->if_flags & IFF_MULTICAST) {
1265 				struct in6_addr llsol;
1266 				int error;
1267 
1268 				llsol = SIN6(rt_key(rt))->sin6_addr;
1269 				llsol.s6_addr16[0] = htons(0xff02);
1270 				llsol.s6_addr16[1] = htons(ifp->if_index);
1271 				llsol.s6_addr32[1] = 0;
1272 				llsol.s6_addr32[2] = htonl(1);
1273 				llsol.s6_addr8[12] = 0xff;
1274 
1275 				if (!in6_addmulti(&llsol, ifp, &error)) {
1276 					nd6log((LOG_ERR, "%s: failed to join "
1277 					    "%s (errno=%d)\n", if_name(ifp),
1278 					    ip6_sprintf(&llsol), error));
1279 				}
1280 			}
1281 		}
1282 		break;
1283 
1284 	case RTM_DELETE:
1285 		if (!ln)
1286 			break;
1287 		/* leave from solicited node multicast for proxy ND */
1288 		if ((rt->rt_flags & RTF_ANNOUNCE) != 0 &&
1289 		    (ifp->if_flags & IFF_MULTICAST) != 0) {
1290 			struct in6_addr llsol;
1291 			struct in6_multi *in6m;
1292 
1293 			llsol = SIN6(rt_key(rt))->sin6_addr;
1294 			llsol.s6_addr16[0] = htons(0xff02);
1295 			llsol.s6_addr16[1] = htons(ifp->if_index);
1296 			llsol.s6_addr32[1] = 0;
1297 			llsol.s6_addr32[2] = htonl(1);
1298 			llsol.s6_addr8[12] = 0xff;
1299 
1300 			IN6_LOOKUP_MULTI(llsol, ifp, in6m);
1301 			if (in6m)
1302 				in6_delmulti(in6m);
1303 		}
1304 		nd6_inuse--;
1305 		ln->ln_next->ln_prev = ln->ln_prev;
1306 		ln->ln_prev->ln_next = ln->ln_next;
1307 		ln->ln_prev = NULL;
1308 		rt->rt_llinfo = 0;
1309 		rt->rt_flags &= ~RTF_LLINFO;
1310 		if (ln->ln_hold)
1311 			m_freem(ln->ln_hold);
1312 		Free((caddr_t)ln);
1313 	}
1314 }
1315 
1316 int
1317 nd6_ioctl(u_long cmd, caddr_t	data, struct ifnet *ifp)
1318 {
1319 	struct in6_drlist *drl = (struct in6_drlist *)data;
1320 	struct in6_prlist *prl = (struct in6_prlist *)data;
1321 	struct in6_ndireq *ndi = (struct in6_ndireq *)data;
1322 	struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data;
1323 	struct in6_ndifreq *ndif = (struct in6_ndifreq *)data;
1324 	struct nd_defrouter *dr, any;
1325 	struct nd_prefix *pr;
1326 	struct rtentry *rt;
1327 	int i = 0, error = 0;
1328 	int s;
1329 
1330 	switch (cmd) {
1331 	case SIOCGDRLST_IN6:
1332 		/*
1333 		 * obsolete API, use sysctl under net.inet6.icmp6
1334 		 */
1335 		bzero(drl, sizeof(*drl));
1336 		s = splnet();
1337 		dr = TAILQ_FIRST(&nd_defrouter);
1338 		while (dr && i < DRLSTSIZ) {
1339 			drl->defrouter[i].rtaddr = dr->rtaddr;
1340 			if (IN6_IS_ADDR_LINKLOCAL(&drl->defrouter[i].rtaddr)) {
1341 				/* XXX: need to this hack for KAME stack */
1342 				drl->defrouter[i].rtaddr.s6_addr16[1] = 0;
1343 			} else
1344 				log(LOG_ERR,
1345 				    "default router list contains a "
1346 				    "non-linklocal address(%s)\n",
1347 				    ip6_sprintf(&drl->defrouter[i].rtaddr));
1348 
1349 			drl->defrouter[i].flags = dr->flags;
1350 			drl->defrouter[i].rtlifetime = dr->rtlifetime;
1351 			drl->defrouter[i].expire = dr->expire;
1352 			drl->defrouter[i].if_index = dr->ifp->if_index;
1353 			i++;
1354 			dr = TAILQ_NEXT(dr, dr_entry);
1355 		}
1356 		splx(s);
1357 		break;
1358 	case SIOCGPRLST_IN6:
1359 		/*
1360 		 * obsolete API, use sysctl under net.inet6.icmp6
1361 		 */
1362 		/*
1363 		 * XXX meaning of fields, especialy "raflags", is very
1364 		 * differnet between RA prefix list and RR/static prefix list.
1365 		 * how about separating ioctls into two?
1366 		 */
1367 		bzero(prl, sizeof(*prl));
1368 		s = splnet();
1369 		pr = nd_prefix.lh_first;
1370 		while (pr && i < PRLSTSIZ) {
1371 			struct nd_pfxrouter *pfr;
1372 			int j;
1373 
1374 			(void)in6_embedscope(&prl->prefix[i].prefix,
1375 			    &pr->ndpr_prefix, NULL, NULL);
1376 			prl->prefix[i].raflags = pr->ndpr_raf;
1377 			prl->prefix[i].prefixlen = pr->ndpr_plen;
1378 			prl->prefix[i].vltime = pr->ndpr_vltime;
1379 			prl->prefix[i].pltime = pr->ndpr_pltime;
1380 			prl->prefix[i].if_index = pr->ndpr_ifp->if_index;
1381 			prl->prefix[i].expire = pr->ndpr_expire;
1382 
1383 			pfr = pr->ndpr_advrtrs.lh_first;
1384 			j = 0;
1385 			while (pfr) {
1386 				if (j < DRLSTSIZ) {
1387 #define RTRADDR prl->prefix[i].advrtr[j]
1388 					RTRADDR = pfr->router->rtaddr;
1389 					if (IN6_IS_ADDR_LINKLOCAL(&RTRADDR)) {
1390 						/* XXX: hack for KAME */
1391 						RTRADDR.s6_addr16[1] = 0;
1392 					} else
1393 						log(LOG_ERR,
1394 						    "a router(%s) advertises "
1395 						    "a prefix with "
1396 						    "non-link local address\n",
1397 						    ip6_sprintf(&RTRADDR));
1398 #undef RTRADDR
1399 				}
1400 				j++;
1401 				pfr = pfr->pfr_next;
1402 			}
1403 			prl->prefix[i].advrtrs = j;
1404 			prl->prefix[i].origin = PR_ORIG_RA;
1405 
1406 			i++;
1407 			pr = pr->ndpr_next;
1408 		}
1409 	      {
1410 		struct rr_prefix *rpp;
1411 
1412 		for (rpp = LIST_FIRST(&rr_prefix); rpp;
1413 		     rpp = LIST_NEXT(rpp, rp_entry)) {
1414 			if (i >= PRLSTSIZ)
1415 				break;
1416 			(void)in6_embedscope(&prl->prefix[i].prefix,
1417 			    &pr->ndpr_prefix, NULL, NULL);
1418 			prl->prefix[i].raflags = rpp->rp_raf;
1419 			prl->prefix[i].prefixlen = rpp->rp_plen;
1420 			prl->prefix[i].vltime = rpp->rp_vltime;
1421 			prl->prefix[i].pltime = rpp->rp_pltime;
1422 			prl->prefix[i].if_index = rpp->rp_ifp->if_index;
1423 			prl->prefix[i].expire = rpp->rp_expire;
1424 			prl->prefix[i].advrtrs = 0;
1425 			prl->prefix[i].origin = rpp->rp_origin;
1426 			i++;
1427 		}
1428 	      }
1429 		splx(s);
1430 
1431 		break;
1432 	case OSIOCGIFINFO_IN6:
1433 		if (!nd_ifinfo || i >= nd_ifinfo_indexlim) {
1434 			error = EINVAL;
1435 			break;
1436 		}
1437 		ndi->ndi.linkmtu = nd_ifinfo[ifp->if_index].linkmtu;
1438 		ndi->ndi.maxmtu = nd_ifinfo[ifp->if_index].maxmtu;
1439 		ndi->ndi.basereachable =
1440 		    nd_ifinfo[ifp->if_index].basereachable;
1441 		ndi->ndi.reachable = nd_ifinfo[ifp->if_index].reachable;
1442 		ndi->ndi.retrans = nd_ifinfo[ifp->if_index].retrans;
1443 		ndi->ndi.flags = nd_ifinfo[ifp->if_index].flags;
1444 		ndi->ndi.recalctm = nd_ifinfo[ifp->if_index].recalctm;
1445 		ndi->ndi.chlim = nd_ifinfo[ifp->if_index].chlim;
1446 		ndi->ndi.receivedra = nd_ifinfo[ifp->if_index].receivedra;
1447 		break;
1448 	case SIOCGIFINFO_IN6:
1449 		if (!nd_ifinfo || i >= nd_ifinfo_indexlim) {
1450 			error = EINVAL;
1451 			break;
1452 		}
1453 		ndi->ndi = nd_ifinfo[ifp->if_index];
1454 		break;
1455 	case SIOCSIFINFO_FLAGS:
1456 		/* XXX: almost all other fields of ndi->ndi is unused */
1457 		if (!nd_ifinfo || i >= nd_ifinfo_indexlim) {
1458 			error = EINVAL;
1459 			break;
1460 		}
1461 		nd_ifinfo[ifp->if_index].flags = ndi->ndi.flags;
1462 		break;
1463 	case SIOCSNDFLUSH_IN6:	/* XXX: the ioctl name is confusing... */
1464 		/* flush default router list */
1465 		/*
1466 		 * xxx sumikawa: should not delete route if default
1467 		 * route equals to the top of default router list
1468 		 */
1469 		bzero(&any, sizeof(any));
1470 		defrouter_delreq(&any, 0);
1471 		defrouter_select();
1472 		/* xxx sumikawa: flush prefix list */
1473 		break;
1474 	case SIOCSPFXFLUSH_IN6:
1475 	    {
1476 		/* flush all the prefix advertised by routers */
1477 		struct nd_prefix *pr, *next;
1478 
1479 		s = splnet();
1480 		for (pr = nd_prefix.lh_first; pr; pr = next) {
1481 			struct in6_ifaddr *ia, *ia_next;
1482 
1483 			next = pr->ndpr_next;
1484 
1485 			if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1486 				continue; /* XXX */
1487 
1488 			/* do we really have to remove addresses as well? */
1489 			for (ia = in6_ifaddr; ia; ia = ia_next) {
1490 				/* ia might be removed.  keep the next ptr. */
1491 				ia_next = ia->ia_next;
1492 
1493 				if ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1494 					continue;
1495 
1496 				if (ia->ia6_ndpr == pr)
1497 					in6_purgeaddr(&ia->ia_ifa);
1498 			}
1499 			prelist_remove(pr);
1500 		}
1501 		splx(s);
1502 		break;
1503 	    }
1504 	case SIOCSRTRFLUSH_IN6:
1505 	    {
1506 		/* flush all the default routers */
1507 		struct nd_defrouter *dr, *next;
1508 
1509 		s = splnet();
1510 		if ((dr = TAILQ_FIRST(&nd_defrouter)) != NULL) {
1511 			/*
1512 			 * The first entry of the list may be stored in
1513 			 * the routing table, so we'll delete it later.
1514 			 */
1515 			for (dr = TAILQ_NEXT(dr, dr_entry); dr; dr = next) {
1516 				next = TAILQ_NEXT(dr, dr_entry);
1517 				defrtrlist_del(dr);
1518 			}
1519 			defrtrlist_del(TAILQ_FIRST(&nd_defrouter));
1520 		}
1521 		splx(s);
1522 		break;
1523 	    }
1524 	case SIOCGNBRINFO_IN6:
1525 	    {
1526 		struct llinfo_nd6 *ln;
1527 		struct in6_addr nb_addr = nbi->addr; /* make local for safety */
1528 
1529 		/*
1530 		 * XXX: KAME specific hack for scoped addresses
1531 		 *      XXXX: for other scopes than link-local?
1532 		 */
1533 		if (IN6_IS_ADDR_LINKLOCAL(&nbi->addr) ||
1534 		    IN6_IS_ADDR_MC_LINKLOCAL(&nbi->addr)) {
1535 			u_int16_t *idp = (u_int16_t *)&nb_addr.s6_addr[2];
1536 
1537 			if (*idp == 0)
1538 				*idp = htons(ifp->if_index);
1539 		}
1540 
1541 		s = splnet();
1542 		if ((rt = nd6_lookup(&nb_addr, 0, ifp)) == NULL) {
1543 			error = EINVAL;
1544 			splx(s);
1545 			break;
1546 		}
1547 		ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1548 		nbi->state = ln->ln_state;
1549 		nbi->asked = ln->ln_asked;
1550 		nbi->isrouter = ln->ln_router;
1551 		nbi->expire = ln->ln_expire;
1552 		splx(s);
1553 
1554 		break;
1555 	    }
1556 	case SIOCGDEFIFACE_IN6:	/* XXX: should be implemented as a sysctl? */
1557 		ndif->ifindex = nd6_defifindex;
1558 		break;
1559 	case SIOCSDEFIFACE_IN6:	/* XXX: should be implemented as a sysctl? */
1560 		return(nd6_setdefaultiface(ndif->ifindex));
1561 		break;
1562 	}
1563 	return(error);
1564 }
1565 
1566 /*
1567  * Create neighbor cache entry and cache link-layer address,
1568  * on reception of inbound ND6 packets. (RS/RA/NS/redirect)
1569  */
1570 struct rtentry *
1571 nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr,
1572 		 int lladdrlen,
1573 		 int type,	/* ICMP6 type */
1574 		 int code	/* type dependent information */)
1575 {
1576 	struct rtentry *rt = NULL;
1577 	struct llinfo_nd6 *ln = NULL;
1578 	int is_newentry;
1579 	struct sockaddr_dl *sdl = NULL;
1580 	int do_update;
1581 	int olladdr;
1582 	int llchange;
1583 	int newstate = 0;
1584 
1585 	if (!ifp)
1586 		panic("ifp == NULL in nd6_cache_lladdr");
1587 	if (!from)
1588 		panic("from == NULL in nd6_cache_lladdr");
1589 
1590 	/* nothing must be updated for unspecified address */
1591 	if (IN6_IS_ADDR_UNSPECIFIED(from))
1592 		return NULL;
1593 
1594 	/*
1595 	 * Validation about ifp->if_addrlen and lladdrlen must be done in
1596 	 * the caller.
1597 	 *
1598 	 * XXX If the link does not have link-layer adderss, what should
1599 	 * we do? (ifp->if_addrlen == 0)
1600 	 * Spec says nothing in sections for RA, RS and NA.  There's small
1601 	 * description on it in NS section (RFC 2461 7.2.3).
1602 	 */
1603 
1604 	rt = nd6_lookup(from, 0, ifp);
1605 	if (!rt) {
1606 #if 0
1607 		/* nothing must be done if there's no lladdr */
1608 		if (!lladdr || !lladdrlen)
1609 			return NULL;
1610 #endif
1611 
1612 		rt = nd6_lookup(from, 1, ifp);
1613 		is_newentry = 1;
1614 	} else {
1615 		/* do nothing if static ndp is set */
1616 		if (rt->rt_flags & RTF_STATIC)
1617 			return NULL;
1618 		is_newentry = 0;
1619 	}
1620 
1621 	if (!rt)
1622 		return NULL;
1623 	if ((rt->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) != RTF_LLINFO) {
1624 fail:
1625 		(void)nd6_free(rt);
1626 		return NULL;
1627 	}
1628 	ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1629 	if (!ln)
1630 		goto fail;
1631 	if (!rt->rt_gateway)
1632 		goto fail;
1633 	if (rt->rt_gateway->sa_family != AF_LINK)
1634 		goto fail;
1635 	sdl = SDL(rt->rt_gateway);
1636 
1637 	olladdr = (sdl->sdl_alen) ? 1 : 0;
1638 	if (olladdr && lladdr) {
1639 		if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen))
1640 			llchange = 1;
1641 		else
1642 			llchange = 0;
1643 	} else
1644 		llchange = 0;
1645 
1646 	/*
1647 	 * newentry olladdr  lladdr  llchange	(*=record)
1648 	 *	0	n	n	--	(1)
1649 	 *	0	y	n	--	(2)
1650 	 *	0	n	y	--	(3) * STALE
1651 	 *	0	y	y	n	(4) *
1652 	 *	0	y	y	y	(5) * STALE
1653 	 *	1	--	n	--	(6)   NOSTATE(= PASSIVE)
1654 	 *	1	--	y	--	(7) * STALE
1655 	 */
1656 
1657 	if (lladdr) {		/* (3-5) and (7) */
1658 		/*
1659 		 * Record source link-layer address
1660 		 * XXX is it dependent to ifp->if_type?
1661 		 */
1662 		sdl->sdl_alen = ifp->if_addrlen;
1663 		bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen);
1664 	}
1665 
1666 	if (!is_newentry) {
1667 		if ((!olladdr && lladdr)		/* (3) */
1668 		 || (olladdr && lladdr && llchange)) {	/* (5) */
1669 			do_update = 1;
1670 			newstate = ND6_LLINFO_STALE;
1671 		} else					/* (1-2,4) */
1672 			do_update = 0;
1673 	} else {
1674 		do_update = 1;
1675 		if (!lladdr)				/* (6) */
1676 			newstate = ND6_LLINFO_NOSTATE;
1677 		else					/* (7) */
1678 			newstate = ND6_LLINFO_STALE;
1679 	}
1680 
1681 	if (do_update) {
1682 		/*
1683 		 * Update the state of the neighbor cache.
1684 		 */
1685 		ln->ln_state = newstate;
1686 
1687 		if (ln->ln_state == ND6_LLINFO_STALE) {
1688 			/*
1689 			 * XXX: since nd6_output() below will cause
1690 			 * state tansition to DELAY and reset the timer,
1691 			 * we must set the timer now, although it is actually
1692 			 * meaningless.
1693 			 */
1694 			ln->ln_expire = time_second + nd6_gctimer;
1695 
1696 			if (ln->ln_hold) {
1697 				/*
1698 				 * we assume ifp is not a p2p here, so just
1699 				 * set the 2nd argument as the 1st one.
1700 				 */
1701 				nd6_output(ifp, ifp, ln->ln_hold,
1702 					   (struct sockaddr_in6 *)rt_key(rt),
1703 					   rt);
1704 				ln->ln_hold = NULL;
1705 			}
1706 		} else if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
1707 			/* probe right away */
1708 			ln->ln_expire = time_second;
1709 		}
1710 	}
1711 
1712 	/*
1713 	 * ICMP6 type dependent behavior.
1714 	 *
1715 	 * NS: clear IsRouter if new entry
1716 	 * RS: clear IsRouter
1717 	 * RA: set IsRouter if there's lladdr
1718 	 * redir: clear IsRouter if new entry
1719 	 *
1720 	 * RA case, (1):
1721 	 * The spec says that we must set IsRouter in the following cases:
1722 	 * - If lladdr exist, set IsRouter.  This means (1-5).
1723 	 * - If it is old entry (!newentry), set IsRouter.  This means (7).
1724 	 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
1725 	 * A quetion arises for (1) case.  (1) case has no lladdr in the
1726 	 * neighbor cache, this is similar to (6).
1727 	 * This case is rare but we figured that we MUST NOT set IsRouter.
1728 	 *
1729 	 * newentry olladdr  lladdr  llchange	    NS  RS  RA	redir
1730 	 *							D R
1731 	 *	0	n	n	--	(1)	c   ?     s
1732 	 *	0	y	n	--	(2)	c   s     s
1733 	 *	0	n	y	--	(3)	c   s     s
1734 	 *	0	y	y	n	(4)	c   s     s
1735 	 *	0	y	y	y	(5)	c   s     s
1736 	 *	1	--	n	--	(6) c	c 	c s
1737 	 *	1	--	y	--	(7) c	c   s	c s
1738 	 *
1739 	 *					(c=clear s=set)
1740 	 */
1741 	switch (type & 0xff) {
1742 	case ND_NEIGHBOR_SOLICIT:
1743 		/*
1744 		 * New entry must have is_router flag cleared.
1745 		 */
1746 		if (is_newentry)	/* (6-7) */
1747 			ln->ln_router = 0;
1748 		break;
1749 	case ND_REDIRECT:
1750 		/*
1751 		 * If the icmp is a redirect to a better router, always set the
1752 		 * is_router flag. Otherwise, if the entry is newly created,
1753 		 * clear the flag. [RFC 2461, sec 8.3]
1754 		 */
1755 		if (code == ND_REDIRECT_ROUTER)
1756 			ln->ln_router = 1;
1757 		else if (is_newentry) /* (6-7) */
1758 			ln->ln_router = 0;
1759 		break;
1760 	case ND_ROUTER_SOLICIT:
1761 		/*
1762 		 * is_router flag must always be cleared.
1763 		 */
1764 		ln->ln_router = 0;
1765 		break;
1766 	case ND_ROUTER_ADVERT:
1767 		/*
1768 		 * Mark an entry with lladdr as a router.
1769 		 */
1770 		if ((!is_newentry && (olladdr || lladdr))	/* (2-5) */
1771 		 || (is_newentry && lladdr)) {			/* (7) */
1772 			ln->ln_router = 1;
1773 		}
1774 		break;
1775 	}
1776 
1777 	/*
1778 	 * When the link-layer address of a router changes, select the
1779 	 * best router again.  In particular, when the neighbor entry is newly
1780 	 * created, it might affect the selection policy.
1781 	 * Question: can we restrict the first condition to the "is_newentry"
1782 	 * case?
1783 	 * XXX: when we hear an RA from a new router with the link-layer
1784 	 * address option, defrouter_select() is called twice, since
1785 	 * defrtrlist_update called the function as well.  However, I believe
1786 	 * we can compromise the overhead, since it only happens the first
1787 	 * time.
1788 	 * XXX: although defrouter_select() should not have a bad effect
1789 	 * for those are not autoconfigured hosts, we explicitly avoid such
1790 	 * cases for safety.
1791 	 */
1792 	if (do_update && ln->ln_router && !ip6_forwarding && ip6_accept_rtadv)
1793 		defrouter_select();
1794 
1795 	return rt;
1796 }
1797 
1798 static void
1799 nd6_slowtimo(void *ignored_arg)
1800 {
1801 	int s = splnet();
1802 	int i;
1803 	struct nd_ifinfo *nd6if;
1804 
1805 	callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
1806 	    nd6_slowtimo, NULL);
1807 	for (i = 1; i < if_index + 1; i++) {
1808 		if (!nd_ifinfo || i >= nd_ifinfo_indexlim)
1809 			continue;
1810 		nd6if = &nd_ifinfo[i];
1811 		if (nd6if->basereachable && /* already initialized */
1812 		    (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
1813 			/*
1814 			 * Since reachable time rarely changes by router
1815 			 * advertisements, we SHOULD insure that a new random
1816 			 * value gets recomputed at least once every few hours.
1817 			 * (RFC 2461, 6.3.4)
1818 			 */
1819 			nd6if->recalctm = nd6_recalc_reachtm_interval;
1820 			nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable);
1821 		}
1822 	}
1823 	splx(s);
1824 }
1825 
1826 #define senderr(e) { error = (e); goto bad;}
1827 int
1828 nd6_output(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m0,
1829 	   struct sockaddr_in6 *dst, struct rtentry *rt0)
1830 {
1831 	struct mbuf *m = m0;
1832 	struct rtentry *rt = rt0;
1833 	struct sockaddr_in6 *gw6 = NULL;
1834 	struct llinfo_nd6 *ln = NULL;
1835 	int error = 0;
1836 
1837 	if (IN6_IS_ADDR_MULTICAST(&dst->sin6_addr))
1838 		goto sendpkt;
1839 
1840 	if (nd6_need_cache(ifp) == 0)
1841 		goto sendpkt;
1842 
1843 	/*
1844 	 * next hop determination.  This routine is derived from ether_outpout.
1845 	 */
1846 	if (rt) {
1847 		if ((rt->rt_flags & RTF_UP) == 0) {
1848 			if ((rt0 = rt = rtalloc1((struct sockaddr *)dst, 1, 0UL)) !=
1849 				NULL)
1850 			{
1851 				rt->rt_refcnt--;
1852 				if (rt->rt_ifp != ifp) {
1853 					/* XXX: loop care? */
1854 					return nd6_output(ifp, origifp, m0,
1855 							  dst, rt);
1856 				}
1857 			} else
1858 				senderr(EHOSTUNREACH);
1859 		}
1860 
1861 		if (rt->rt_flags & RTF_GATEWAY) {
1862 			gw6 = (struct sockaddr_in6 *)rt->rt_gateway;
1863 
1864 			/*
1865 			 * We skip link-layer address resolution and NUD
1866 			 * if the gateway is not a neighbor from ND point
1867 			 * of view, regardless of the value of nd_ifinfo.flags.
1868 			 * The second condition is a bit tricky; we skip
1869 			 * if the gateway is our own address, which is
1870 			 * sometimes used to install a route to a p2p link.
1871 			 */
1872 			if (!nd6_is_addr_neighbor(gw6, ifp) ||
1873 			    in6ifa_ifpwithaddr(ifp, &gw6->sin6_addr)) {
1874 				/*
1875 				 * We allow this kind of tricky route only
1876 				 * when the outgoing interface is p2p.
1877 				 * XXX: we may need a more generic rule here.
1878 				 */
1879 				if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
1880 					senderr(EHOSTUNREACH);
1881 
1882 				goto sendpkt;
1883 			}
1884 
1885 			if (rt->rt_gwroute == 0)
1886 				goto lookup;
1887 			if (((rt = rt->rt_gwroute)->rt_flags & RTF_UP) == 0) {
1888 				rtfree(rt); rt = rt0;
1889 			lookup: rt->rt_gwroute = rtalloc1(rt->rt_gateway, 1, 0UL);
1890 				if ((rt = rt->rt_gwroute) == 0)
1891 					senderr(EHOSTUNREACH);
1892 			}
1893 		}
1894 	}
1895 
1896 	/*
1897 	 * Address resolution or Neighbor Unreachability Detection
1898 	 * for the next hop.
1899 	 * At this point, the destination of the packet must be a unicast
1900 	 * or an anycast address(i.e. not a multicast).
1901 	 */
1902 
1903 	/* Look up the neighbor cache for the nexthop */
1904 	if (rt && (rt->rt_flags & RTF_LLINFO) != 0)
1905 		ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1906 	else {
1907 		/*
1908 		 * Since nd6_is_addr_neighbor() internally calls nd6_lookup(),
1909 		 * the condition below is not very efficient.  But we believe
1910 		 * it is tolerable, because this should be a rare case.
1911 		 */
1912 		if (nd6_is_addr_neighbor(dst, ifp) &&
1913 		    (rt = nd6_lookup(&dst->sin6_addr, 1, ifp)) != NULL)
1914 			ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1915 	}
1916 	if (!ln || !rt) {
1917 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0 &&
1918 		    !(nd_ifinfo[ifp->if_index].flags & ND6_IFF_PERFORMNUD)) {
1919 			log(LOG_DEBUG,
1920 			    "nd6_output: can't allocate llinfo for %s "
1921 			    "(ln=%p, rt=%p)\n",
1922 			    ip6_sprintf(&dst->sin6_addr), ln, rt);
1923 			senderr(EIO);	/* XXX: good error? */
1924 		}
1925 
1926 		goto sendpkt;	/* send anyway */
1927 	}
1928 
1929 	/* We don't have to do link-layer address resolution on a p2p link. */
1930 	if ((ifp->if_flags & IFF_POINTOPOINT) != 0 &&
1931 	    ln->ln_state < ND6_LLINFO_REACHABLE) {
1932 		ln->ln_state = ND6_LLINFO_STALE;
1933 		ln->ln_expire = time_second + nd6_gctimer;
1934 	}
1935 
1936 	/*
1937 	 * The first time we send a packet to a neighbor whose entry is
1938 	 * STALE, we have to change the state to DELAY and a sets a timer to
1939 	 * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do
1940 	 * neighbor unreachability detection on expiration.
1941 	 * (RFC 2461 7.3.3)
1942 	 */
1943 	if (ln->ln_state == ND6_LLINFO_STALE) {
1944 		ln->ln_asked = 0;
1945 		ln->ln_state = ND6_LLINFO_DELAY;
1946 		ln->ln_expire = time_second + nd6_delay;
1947 	}
1948 
1949 	/*
1950 	 * If the neighbor cache entry has a state other than INCOMPLETE
1951 	 * (i.e. its link-layer address is already resolved), just
1952 	 * send the packet.
1953 	 */
1954 	if (ln->ln_state > ND6_LLINFO_INCOMPLETE)
1955 		goto sendpkt;
1956 
1957 	/*
1958 	 * There is a neighbor cache entry, but no ethernet address
1959 	 * response yet.  Replace the held mbuf (if any) with this
1960 	 * latest one.
1961 	 *
1962 	 * This code conforms to the rate-limiting rule described in Section
1963 	 * 7.2.2 of RFC 2461, because the timer is set correctly after sending
1964 	 * an NS below.
1965 	 */
1966 	if (ln->ln_state == ND6_LLINFO_NOSTATE)
1967 		ln->ln_state = ND6_LLINFO_INCOMPLETE;
1968 	if (ln->ln_hold)
1969 		m_freem(ln->ln_hold);
1970 	ln->ln_hold = m;
1971 	if (ln->ln_expire) {
1972 		if (ln->ln_asked < nd6_mmaxtries &&
1973 		    ln->ln_expire < time_second) {
1974 			ln->ln_asked++;
1975 			ln->ln_expire = time_second +
1976 				nd_ifinfo[ifp->if_index].retrans / 1000;
1977 			nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0);
1978 		}
1979 	}
1980 	return(0);
1981 
1982   sendpkt:
1983 
1984 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
1985 		return((*ifp->if_output)(origifp, m, (struct sockaddr *)dst,
1986 					 rt));
1987 	}
1988 	return((*ifp->if_output)(ifp, m, (struct sockaddr *)dst, rt));
1989 
1990   bad:
1991 	if (m)
1992 		m_freem(m);
1993 	return (error);
1994 }
1995 #undef senderr
1996 
1997 int
1998 nd6_need_cache(struct ifnet *ifp)
1999 {
2000 	/*
2001 	 * XXX: we currently do not make neighbor cache on any interface
2002 	 * other than ARCnet, Ethernet, FDDI and GIF.
2003 	 *
2004 	 * RFC2893 says:
2005 	 * - unidirectional tunnels needs no ND
2006 	 */
2007 	switch (ifp->if_type) {
2008 	case IFT_ARCNET:
2009 	case IFT_ETHER:
2010 	case IFT_FDDI:
2011 	case IFT_IEEE1394:
2012 #ifdef IFT_L2VLAN
2013 	case IFT_L2VLAN:
2014 #endif
2015 #ifdef IFT_IEEE80211
2016 	case IFT_IEEE80211:
2017 #endif
2018 	case IFT_GIF:		/* XXX need more cases? */
2019 		return(1);
2020 	default:
2021 		return(0);
2022 	}
2023 }
2024 
2025 int
2026 nd6_storelladdr(struct ifnet *ifp, struct rtentry *rt, struct mbuf *m,
2027 		struct sockaddr *dst, u_char *desten)
2028 {
2029 	struct sockaddr_dl *sdl;
2030 
2031 	if (m->m_flags & M_MCAST) {
2032 		switch (ifp->if_type) {
2033 		case IFT_ETHER:
2034 		case IFT_FDDI:
2035 #ifdef IFT_L2VLAN
2036 	case IFT_L2VLAN:
2037 #endif
2038 #ifdef IFT_IEEE80211
2039 		case IFT_IEEE80211:
2040 #endif
2041 			ETHER_MAP_IPV6_MULTICAST(&SIN6(dst)->sin6_addr,
2042 						 desten);
2043 			return(1);
2044 		case IFT_IEEE1394:
2045 			bcopy(ifp->if_broadcastaddr, desten, ifp->if_addrlen);
2046 			return(1);
2047 		case IFT_ARCNET:
2048 			*desten = 0;
2049 			return(1);
2050 		default:
2051 			m_freem(m);
2052 			return(0);
2053 		}
2054 	}
2055 
2056 	if (rt == NULL) {
2057 		/* this could happen, if we could not allocate memory */
2058 		m_freem(m);
2059 		return(0);
2060 	}
2061 	if (rt->rt_gateway->sa_family != AF_LINK) {
2062 		printf("nd6_storelladdr: something odd happens\n");
2063 		m_freem(m);
2064 		return(0);
2065 	}
2066 	sdl = SDL(rt->rt_gateway);
2067 	if (sdl->sdl_alen == 0) {
2068 		/* this should be impossible, but we bark here for debugging */
2069 		printf("nd6_storelladdr: sdl_alen == 0\n");
2070 		m_freem(m);
2071 		return(0);
2072 	}
2073 
2074 	bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
2075 	return(1);
2076 }
2077 
2078 static int nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS);
2079 static int nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS);
2080 #ifdef SYSCTL_DECL
2081 SYSCTL_DECL(_net_inet6_icmp6);
2082 #endif
2083 SYSCTL_NODE(_net_inet6_icmp6, ICMPV6CTL_ND6_DRLIST, nd6_drlist,
2084 	CTLFLAG_RD, nd6_sysctl_drlist, "");
2085 SYSCTL_NODE(_net_inet6_icmp6, ICMPV6CTL_ND6_PRLIST, nd6_prlist,
2086 	CTLFLAG_RD, nd6_sysctl_prlist, "");
2087 
2088 static int
2089 nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS)
2090 {
2091 	int error;
2092 	char buf[1024];
2093 	struct in6_defrouter *d, *de;
2094 	struct nd_defrouter *dr;
2095 
2096 	if (req->newptr)
2097 		return EPERM;
2098 	error = 0;
2099 
2100 	for (dr = TAILQ_FIRST(&nd_defrouter);
2101 	     dr;
2102 	     dr = TAILQ_NEXT(dr, dr_entry)) {
2103 		d = (struct in6_defrouter *)buf;
2104 		de = (struct in6_defrouter *)(buf + sizeof(buf));
2105 
2106 		if (d + 1 <= de) {
2107 			bzero(d, sizeof(*d));
2108 			d->rtaddr.sin6_family = AF_INET6;
2109 			d->rtaddr.sin6_len = sizeof(d->rtaddr);
2110 			if (in6_recoverscope(&d->rtaddr, &dr->rtaddr,
2111 			    dr->ifp) != 0)
2112 				log(LOG_ERR,
2113 				    "scope error in "
2114 				    "default router list (%s)\n",
2115 				    ip6_sprintf(&dr->rtaddr));
2116 			d->flags = dr->flags;
2117 			d->rtlifetime = dr->rtlifetime;
2118 			d->expire = dr->expire;
2119 			d->if_index = dr->ifp->if_index;
2120 		} else
2121 			panic("buffer too short");
2122 
2123 		error = SYSCTL_OUT(req, buf, sizeof(*d));
2124 		if (error)
2125 			break;
2126 	}
2127 	return error;
2128 }
2129 
2130 static int
2131 nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS)
2132 {
2133 	int error;
2134 	char buf[1024];
2135 	struct in6_prefix *p, *pe;
2136 	struct nd_prefix *pr;
2137 
2138 	if (req->newptr)
2139 		return EPERM;
2140 	error = 0;
2141 
2142 	for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
2143 		u_short advrtrs;
2144 		size_t advance;
2145 		struct sockaddr_in6 *sin6, *s6;
2146 		struct nd_pfxrouter *pfr;
2147 
2148 		p = (struct in6_prefix *)buf;
2149 		pe = (struct in6_prefix *)(buf + sizeof(buf));
2150 
2151 		if (p + 1 <= pe) {
2152 			bzero(p, sizeof(*p));
2153 			sin6 = (struct sockaddr_in6 *)(p + 1);
2154 
2155 			p->prefix = pr->ndpr_prefix;
2156 			if (in6_recoverscope(&p->prefix,
2157 			    &p->prefix.sin6_addr, pr->ndpr_ifp) != 0)
2158 				log(LOG_ERR,
2159 				    "scope error in prefix list (%s)\n",
2160 				    ip6_sprintf(&p->prefix.sin6_addr));
2161 			p->raflags = pr->ndpr_raf;
2162 			p->prefixlen = pr->ndpr_plen;
2163 			p->vltime = pr->ndpr_vltime;
2164 			p->pltime = pr->ndpr_pltime;
2165 			p->if_index = pr->ndpr_ifp->if_index;
2166 			p->expire = pr->ndpr_expire;
2167 			p->refcnt = pr->ndpr_refcnt;
2168 			p->flags = pr->ndpr_stateflags;
2169 			p->origin = PR_ORIG_RA;
2170 			advrtrs = 0;
2171 			for (pfr = pr->ndpr_advrtrs.lh_first;
2172 			     pfr;
2173 			     pfr = pfr->pfr_next) {
2174 				if ((void *)&sin6[advrtrs + 1] >
2175 				    (void *)pe) {
2176 					advrtrs++;
2177 					continue;
2178 				}
2179 				s6 = &sin6[advrtrs];
2180 				bzero(s6, sizeof(*s6));
2181 				s6->sin6_family = AF_INET6;
2182 				s6->sin6_len = sizeof(*sin6);
2183 				if (in6_recoverscope(s6,
2184 				    &pfr->router->rtaddr,
2185 				    pfr->router->ifp) != 0)
2186 					log(LOG_ERR,
2187 					    "scope error in "
2188 					    "prefix list (%s)\n",
2189 					    ip6_sprintf(&pfr->router->rtaddr));
2190 				advrtrs++;
2191 			}
2192 			p->advrtrs = advrtrs;
2193 		} else
2194 			panic("buffer too short");
2195 
2196 		advance = sizeof(*p) + sizeof(*sin6) * advrtrs;
2197 		error = SYSCTL_OUT(req, buf, advance);
2198 		if (error)
2199 			break;
2200 	}
2201 	return error;
2202 }
2203