xref: /netbsd-src/sys/netinet6/nd6.c (revision 3b01aba77a7a698587faaae455bbfe740923c1f5)
1 /*	$NetBSD: nd6.c,v 1.51 2001/07/25 06:59:52 itojun Exp $	*/
2 /*	$KAME: nd6.c,v 1.151 2001/06/19 14:24:41 sumikawa Exp $	*/
3 
4 /*
5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * XXX
35  * KAME 970409 note:
36  * BSD/OS version heavily modifies this code, related to llinfo.
37  * Since we don't have BSD/OS version of net/route.c in our hand,
38  * I left the code mostly as it was in 970310.  -- itojun
39  */
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/callout.h>
44 #include <sys/malloc.h>
45 #include <sys/mbuf.h>
46 #include <sys/socket.h>
47 #include <sys/sockio.h>
48 #include <sys/time.h>
49 #include <sys/kernel.h>
50 #include <sys/protosw.h>
51 #include <sys/errno.h>
52 #include <sys/ioctl.h>
53 #include <sys/syslog.h>
54 #include <sys/queue.h>
55 
56 #include <net/if.h>
57 #include <net/if_dl.h>
58 #include <net/if_types.h>
59 #include <net/if_atm.h>
60 #include <net/if_ieee1394.h>
61 #include <net/route.h>
62 
63 #include <netinet/in.h>
64 #include <net/if_ether.h>
65 #include <netinet/if_inarp.h>
66 #include <net/if_fddi.h>
67 #include <netinet6/in6_var.h>
68 #include <netinet/ip6.h>
69 #include <netinet6/ip6_var.h>
70 #include <netinet6/nd6.h>
71 #include <netinet6/in6_prefix.h>
72 #include <netinet/icmp6.h>
73 
74 #include "loop.h"
75 extern struct ifnet loif[NLOOP];
76 
77 #include <net/net_osdep.h>
78 
79 #define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */
80 #define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */
81 
82 #define SIN6(s) ((struct sockaddr_in6 *)s)
83 #define SDL(s) ((struct sockaddr_dl *)s)
84 
85 /* timer values */
86 int	nd6_prune	= 1;	/* walk list every 1 seconds */
87 int	nd6_delay	= 5;	/* delay first probe time 5 second */
88 int	nd6_umaxtries	= 3;	/* maximum unicast query */
89 int	nd6_mmaxtries	= 3;	/* maximum multicast query */
90 int	nd6_useloopback = 1;	/* use loopback interface for local traffic */
91 int	nd6_gctimer	= (60 * 60 * 24); /* 1 day: garbage collection timer */
92 
93 /* preventing too many loops in ND option parsing */
94 int nd6_maxndopt = 10;	/* max # of ND options allowed */
95 
96 int nd6_maxnudhint = 0;	/* max # of subsequent upper layer hints */
97 
98 #ifdef ND6_DEBUG
99 int nd6_debug = 1;
100 #else
101 int nd6_debug = 0;
102 #endif
103 
104 /* for debugging? */
105 static int nd6_inuse, nd6_allocated;
106 
107 struct llinfo_nd6 llinfo_nd6 = {&llinfo_nd6, &llinfo_nd6};
108 static size_t nd_ifinfo_indexlim = 8;
109 struct nd_ifinfo *nd_ifinfo = NULL;
110 struct nd_drhead nd_defrouter;
111 struct nd_prhead nd_prefix = { 0 };
112 
113 int nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL;
114 static struct sockaddr_in6 all1_sa;
115 
116 static void nd6_slowtimo __P((void *));
117 
118 struct callout nd6_slowtimo_ch;
119 struct callout nd6_timer_ch;
120 
121 void
122 nd6_init()
123 {
124 	static int nd6_init_done = 0;
125 	int i;
126 
127 	if (nd6_init_done) {
128 		log(LOG_NOTICE, "nd6_init called more than once(ignored)\n");
129 		return;
130 	}
131 
132 	all1_sa.sin6_family = AF_INET6;
133 	all1_sa.sin6_len = sizeof(struct sockaddr_in6);
134 	for (i = 0; i < sizeof(all1_sa.sin6_addr); i++)
135 		all1_sa.sin6_addr.s6_addr[i] = 0xff;
136 
137 	/* initialization of the default router list */
138 	TAILQ_INIT(&nd_defrouter);
139 
140 	nd6_init_done = 1;
141 
142 	/* start timer */
143 	callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
144 	    nd6_slowtimo, NULL);
145 }
146 
147 void
148 nd6_ifattach(ifp)
149 	struct ifnet *ifp;
150 {
151 
152 	/*
153 	 * We have some arrays that should be indexed by if_index.
154 	 * since if_index will grow dynamically, they should grow too.
155 	 */
156 	if (nd_ifinfo == NULL || if_index >= nd_ifinfo_indexlim) {
157 		size_t n;
158 		caddr_t q;
159 
160 		while (if_index >= nd_ifinfo_indexlim)
161 			nd_ifinfo_indexlim <<= 1;
162 
163 		/* grow nd_ifinfo */
164 		n = nd_ifinfo_indexlim * sizeof(struct nd_ifinfo);
165 		q = (caddr_t)malloc(n, M_IP6NDP, M_WAITOK);
166 		bzero(q, n);
167 		if (nd_ifinfo) {
168 			bcopy((caddr_t)nd_ifinfo, q, n/2);
169 			free((caddr_t)nd_ifinfo, M_IP6NDP);
170 		}
171 		nd_ifinfo = (struct nd_ifinfo *)q;
172 	}
173 
174 #define ND nd_ifinfo[ifp->if_index]
175 
176 	/*
177 	 * Don't initialize if called twice.
178 	 * XXX: to detect this, we should choose a member that is never set
179 	 * before initialization of the ND structure itself.  We formaly used
180 	 * the linkmtu member, which was not suitable because it could be
181 	 * initialized via "ifconfig mtu".
182 	 */
183 	if (ND.basereachable)
184 		return;
185 
186 #ifdef DIAGNOSTIC
187 	if (!ifindex2ifnet[ifp->if_index])
188 		panic("nd6_ifattach: ifindex2ifnet is NULL");
189 #endif
190 	ND.linkmtu = ifindex2ifnet[ifp->if_index]->if_mtu;
191 	ND.chlim = IPV6_DEFHLIM;
192 	ND.basereachable = REACHABLE_TIME;
193 	ND.reachable = ND_COMPUTE_RTIME(ND.basereachable);
194 	ND.retrans = RETRANS_TIMER;
195 	ND.receivedra = 0;
196 	ND.flags = ND6_IFF_PERFORMNUD;
197 	nd6_setmtu(ifp);
198 #undef ND
199 }
200 
201 /*
202  * Reset ND level link MTU. This function is called when the physical MTU
203  * changes, which means we might have to adjust the ND level MTU.
204  */
205 void
206 nd6_setmtu(ifp)
207 	struct ifnet *ifp;
208 {
209 	struct nd_ifinfo *ndi = &nd_ifinfo[ifp->if_index];
210 	u_long oldmaxmtu = ndi->maxmtu;
211 	u_long oldlinkmtu = ndi->linkmtu;
212 
213 	switch (ifp->if_type) {
214 	case IFT_ARCNET:	/* XXX MTU handling needs more work */
215 		ndi->maxmtu = MIN(60480, ifp->if_mtu);
216 		break;
217 	case IFT_ETHER:
218 		ndi->maxmtu = MIN(ETHERMTU, ifp->if_mtu);
219 		break;
220 	case IFT_ATM:
221 		ndi->maxmtu = MIN(ATMMTU, ifp->if_mtu);
222 		break;
223 	case IFT_IEEE1394:
224 		ndi->maxmtu = MIN(IEEE1394MTU, ifp->if_mtu);
225 		break;
226 	default:
227 		ndi->maxmtu = ifp->if_mtu;
228 		break;
229 	}
230 
231 	if (oldmaxmtu != ndi->maxmtu) {
232 		/*
233 		 * If the ND level MTU is not set yet, or if the maxmtu
234 		 * is reset to a smaller value than the ND level MTU,
235 		 * also reset the ND level MTU.
236 		 */
237 		if (ndi->linkmtu == 0 ||
238 		    ndi->maxmtu < ndi->linkmtu) {
239 			ndi->linkmtu = ndi->maxmtu;
240 			/* also adjust in6_maxmtu if necessary. */
241 			if (oldlinkmtu == 0) {
242 				/*
243 				 * XXX: the case analysis is grotty, but
244 				 * it is not efficient to call in6_setmaxmtu()
245 				 * here when we are during the initialization
246 				 * procedure.
247 				 */
248 				if (in6_maxmtu < ndi->linkmtu)
249 					in6_maxmtu = ndi->linkmtu;
250 			} else
251 				in6_setmaxmtu();
252 		}
253 	}
254 #undef MIN
255 }
256 
257 void
258 nd6_option_init(opt, icmp6len, ndopts)
259 	void *opt;
260 	int icmp6len;
261 	union nd_opts *ndopts;
262 {
263 	bzero(ndopts, sizeof(*ndopts));
264 	ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
265 	ndopts->nd_opts_last
266 		= (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len);
267 
268 	if (icmp6len == 0) {
269 		ndopts->nd_opts_done = 1;
270 		ndopts->nd_opts_search = NULL;
271 	}
272 }
273 
274 /*
275  * Take one ND option.
276  */
277 struct nd_opt_hdr *
278 nd6_option(ndopts)
279 	union nd_opts *ndopts;
280 {
281 	struct nd_opt_hdr *nd_opt;
282 	int olen;
283 
284 	if (!ndopts)
285 		panic("ndopts == NULL in nd6_option\n");
286 	if (!ndopts->nd_opts_last)
287 		panic("uninitialized ndopts in nd6_option\n");
288 	if (!ndopts->nd_opts_search)
289 		return NULL;
290 	if (ndopts->nd_opts_done)
291 		return NULL;
292 
293 	nd_opt = ndopts->nd_opts_search;
294 
295 	/* make sure nd_opt_len is inside the buffer */
296 	if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) {
297 		bzero(ndopts, sizeof(*ndopts));
298 		return NULL;
299 	}
300 
301 	olen = nd_opt->nd_opt_len << 3;
302 	if (olen == 0) {
303 		/*
304 		 * Message validation requires that all included
305 		 * options have a length that is greater than zero.
306 		 */
307 		bzero(ndopts, sizeof(*ndopts));
308 		return NULL;
309 	}
310 
311 	ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen);
312 	if (ndopts->nd_opts_search > ndopts->nd_opts_last) {
313 		/* option overruns the end of buffer, invalid */
314 		bzero(ndopts, sizeof(*ndopts));
315 		return NULL;
316 	} else if (ndopts->nd_opts_search == ndopts->nd_opts_last) {
317 		/* reached the end of options chain */
318 		ndopts->nd_opts_done = 1;
319 		ndopts->nd_opts_search = NULL;
320 	}
321 	return nd_opt;
322 }
323 
324 /*
325  * Parse multiple ND options.
326  * This function is much easier to use, for ND routines that do not need
327  * multiple options of the same type.
328  */
329 int
330 nd6_options(ndopts)
331 	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\n");
338 	if (!ndopts->nd_opts_last)
339 		panic("uninitialized ndopts in nd6_options\n");
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(ignored_arg)
411 	void	*ignored_arg;
412 {
413 	int s;
414 	struct llinfo_nd6 *ln;
415 	struct nd_defrouter *dr;
416 	struct nd_prefix *pr;
417 	long time_second = time.tv_sec;
418 
419 	s = splsoftnet();
420 	callout_reset(&nd6_timer_ch, nd6_prune * hz,
421 	    nd6_timer, NULL);
422 
423 	ln = llinfo_nd6.ln_next;
424 	/* XXX BSD/OS separates this code -- itojun */
425 	while (ln && ln != &llinfo_nd6) {
426 		struct rtentry *rt;
427 		struct ifnet *ifp;
428 		struct sockaddr_in6 *dst;
429 		struct llinfo_nd6 *next = ln->ln_next;
430 		/* XXX: used for the DELAY case only: */
431 		struct nd_ifinfo *ndi = NULL;
432 
433 		if ((rt = ln->ln_rt) == NULL) {
434 			ln = next;
435 			continue;
436 		}
437 		if ((ifp = rt->rt_ifp) == NULL) {
438 			ln = next;
439 			continue;
440 		}
441 		ndi = &nd_ifinfo[ifp->if_index];
442 		dst = (struct sockaddr_in6 *)rt_key(rt);
443 
444 		if (ln->ln_expire > time_second) {
445 			ln = next;
446 			continue;
447 		}
448 
449 		/* sanity check */
450 		if (!rt)
451 			panic("rt=0 in nd6_timer(ln=%p)\n", ln);
452 		if (rt->rt_llinfo && (struct llinfo_nd6 *)rt->rt_llinfo != ln)
453 			panic("rt_llinfo(%p) is not equal to ln(%p)\n",
454 			      rt->rt_llinfo, ln);
455 		if (!dst)
456 			panic("dst=0 in nd6_timer(ln=%p)\n", ln);
457 
458 		switch (ln->ln_state) {
459 		case ND6_LLINFO_INCOMPLETE:
460 			if (ln->ln_asked < nd6_mmaxtries) {
461 				ln->ln_asked++;
462 				ln->ln_expire = time_second +
463 					nd_ifinfo[ifp->if_index].retrans / 1000;
464 				nd6_ns_output(ifp, NULL, &dst->sin6_addr,
465 					ln, 0);
466 			} else {
467 				struct mbuf *m = ln->ln_hold;
468 				if (m) {
469 					if (rt->rt_ifp) {
470 						/*
471 						 * Fake rcvif to make ICMP error
472 						 * more helpful in diagnosing
473 						 * for the receiver.
474 						 * XXX: should we consider
475 						 * older rcvif?
476 						 */
477 						m->m_pkthdr.rcvif = rt->rt_ifp;
478 					}
479 					icmp6_error(m, ICMP6_DST_UNREACH,
480 						    ICMP6_DST_UNREACH_ADDR, 0);
481 					ln->ln_hold = NULL;
482 				}
483 				next = nd6_free(rt);
484 			}
485 			break;
486 		case ND6_LLINFO_REACHABLE:
487 			if (ln->ln_expire) {
488 				ln->ln_state = ND6_LLINFO_STALE;
489 				ln->ln_expire = time_second + nd6_gctimer;
490 			}
491 			break;
492 
493 		case ND6_LLINFO_STALE:
494 			/* Garbage Collection(RFC 2461 5.3) */
495 			if (ln->ln_expire)
496 				next = nd6_free(rt);
497 			break;
498 
499 		case ND6_LLINFO_DELAY:
500 			if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) {
501 				/* We need NUD */
502 				ln->ln_asked = 1;
503 				ln->ln_state = ND6_LLINFO_PROBE;
504 				ln->ln_expire = time_second +
505 					ndi->retrans / 1000;
506 				nd6_ns_output(ifp, &dst->sin6_addr,
507 					      &dst->sin6_addr,
508 					      ln, 0);
509 			} else {
510 				ln->ln_state = ND6_LLINFO_STALE; /* XXX */
511 				ln->ln_expire = time_second + nd6_gctimer;
512 			}
513 			break;
514 		case ND6_LLINFO_PROBE:
515 			if (ln->ln_asked < nd6_umaxtries) {
516 				ln->ln_asked++;
517 				ln->ln_expire = time_second +
518 					nd_ifinfo[ifp->if_index].retrans / 1000;
519 				nd6_ns_output(ifp, &dst->sin6_addr,
520 					       &dst->sin6_addr, ln, 0);
521 			} else
522 				next = nd6_free(rt);
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 	pr = nd_prefix.lh_first;
541 	while (pr) {
542 		struct in6_ifaddr *ia6;
543 		struct in6_addrlifetime *lt6;
544 
545 		if (IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr))
546 			ia6 = NULL;
547 		else
548 			ia6 = in6ifa_ifpwithaddr(pr->ndpr_ifp, &pr->ndpr_addr);
549 
550 		if (ia6) {
551 			/* check address lifetime */
552 			lt6 = &ia6->ia6_lifetime;
553 			if (lt6->ia6t_preferred && lt6->ia6t_preferred < time_second)
554 				ia6->ia6_flags |= IN6_IFF_DEPRECATED;
555 			if (lt6->ia6t_expire && lt6->ia6t_expire < time_second) {
556 				if (!IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr))
557 					in6_ifdel(pr->ndpr_ifp, &pr->ndpr_addr);
558 				/* xxx ND_OPT_PI_FLAG_ONLINK processing */
559 			}
560 		}
561 
562 		/*
563 		 * check prefix lifetime.
564 		 * since pltime is just for autoconf, pltime processing for
565 		 * prefix is not necessary.
566 		 *
567 		 * we offset expire time by NDPR_KEEP_EXPIRE, so that we
568 		 * can use the old prefix information to validate the
569 		 * next prefix information to come.  See prelist_update()
570 		 * for actual validation.
571 		 */
572 		if (pr->ndpr_expire
573 		 && pr->ndpr_expire + NDPR_KEEP_EXPIRED < time_second) {
574 			struct nd_prefix *t;
575 			t = pr->ndpr_next;
576 
577 			/*
578 			 * address expiration and prefix expiration are
579 			 * separate.  NEVER perform in6_ifdel here.
580 			 */
581 
582 			prelist_remove(pr);
583 			pr = t;
584 		} else
585 			pr = pr->ndpr_next;
586 	}
587 	splx(s);
588 }
589 
590 /*
591  * Nuke neighbor cache/prefix/default router management table, right before
592  * ifp goes away.
593  */
594 void
595 nd6_purge(ifp)
596 	struct ifnet *ifp;
597 {
598 	struct llinfo_nd6 *ln, *nln;
599 	struct nd_defrouter *dr, *ndr, drany;
600 	struct nd_prefix *pr, *npr;
601 
602 	/* Nuke default router list entries toward ifp */
603 	if ((dr = TAILQ_FIRST(&nd_defrouter)) != NULL) {
604 		/*
605 		 * The first entry of the list may be stored in
606 		 * the routing table, so we'll delete it later.
607 		 */
608 		for (dr = TAILQ_NEXT(dr, dr_entry); dr; dr = ndr) {
609 			ndr = TAILQ_NEXT(dr, dr_entry);
610 			if (dr->ifp == ifp)
611 				defrtrlist_del(dr);
612 		}
613 		dr = TAILQ_FIRST(&nd_defrouter);
614 		if (dr->ifp == ifp)
615 			defrtrlist_del(dr);
616 	}
617 
618 	/* Nuke prefix list entries toward ifp */
619 	for (pr = nd_prefix.lh_first; pr; pr = npr) {
620 		npr = pr->ndpr_next;
621 		if (pr->ndpr_ifp == ifp) {
622 			if (!IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr))
623 				in6_ifdel(pr->ndpr_ifp, &pr->ndpr_addr);
624 			prelist_remove(pr);
625 		}
626 	}
627 
628 	/* cancel default outgoing interface setting */
629 	if (nd6_defifindex == ifp->if_index)
630 		nd6_setdefaultiface(0);
631 
632 	if (!ip6_forwarding && ip6_accept_rtadv) { /* XXX: too restrictive? */
633 		/* refresh default router list */
634 		bzero(&drany, sizeof(drany));
635 		defrouter_delreq(&drany, 0);
636 		defrouter_select();
637 	}
638 
639 	/*
640 	 * Nuke neighbor cache entries for the ifp.
641 	 * Note that rt->rt_ifp may not be the same as ifp,
642 	 * due to KAME goto ours hack.  See RTM_RESOLVE case in
643 	 * nd6_rtrequest(), and ip6_input().
644 	 */
645 	ln = llinfo_nd6.ln_next;
646 	while (ln && ln != &llinfo_nd6) {
647 		struct rtentry *rt;
648 		struct sockaddr_dl *sdl;
649 
650 		nln = ln->ln_next;
651 		rt = ln->ln_rt;
652 		if (rt && rt->rt_gateway &&
653 		    rt->rt_gateway->sa_family == AF_LINK) {
654 			sdl = (struct sockaddr_dl *)rt->rt_gateway;
655 			if (sdl->sdl_index == ifp->if_index)
656 				nln = nd6_free(rt);
657 		}
658 		ln = nln;
659 	}
660 }
661 
662 struct rtentry *
663 nd6_lookup(addr6, create, ifp)
664 	struct in6_addr *addr6;
665 	int create;
666 	struct ifnet *ifp;
667 {
668 	struct rtentry *rt;
669 	struct sockaddr_in6 sin6;
670 
671 	bzero(&sin6, sizeof(sin6));
672 	sin6.sin6_len = sizeof(struct sockaddr_in6);
673 	sin6.sin6_family = AF_INET6;
674 	sin6.sin6_addr = *addr6;
675 	rt = rtalloc1((struct sockaddr *)&sin6, create);
676 	if (rt && (rt->rt_flags & RTF_LLINFO) == 0) {
677 		/*
678 		 * This is the case for the default route.
679 		 * If we want to create a neighbor cache for the address, we
680 		 * should free the route for the destination and allocate an
681 		 * interface route.
682 		 */
683 		if (create) {
684 			RTFREE(rt);
685 			rt = 0;
686 		}
687 	}
688 	if (!rt) {
689 		if (create && ifp) {
690 			int e;
691 
692 			/*
693 			 * If no route is available and create is set,
694 			 * we allocate a host route for the destination
695 			 * and treat it like an interface route.
696 			 * This hack is necessary for a neighbor which can't
697 			 * be covered by our own prefix.
698 			 */
699 			struct ifaddr *ifa =
700 				ifaof_ifpforaddr((struct sockaddr *)&sin6, ifp);
701 			if (ifa == NULL)
702 				return(NULL);
703 
704 			/*
705 			 * Create a new route. RTF_LLINFO is necessary
706 			 * to create a Neighbor Cache entry for the
707 			 * destination in nd6_rtrequest which will be
708 			 * called in rtequest via ifa->ifa_rtrequest.
709 			 */
710 			if ((e = rtrequest(RTM_ADD, (struct sockaddr *)&sin6,
711 					   ifa->ifa_addr,
712 					   (struct sockaddr *)&all1_sa,
713 					   (ifa->ifa_flags |
714 					    RTF_HOST | RTF_LLINFO) &
715 					   ~RTF_CLONING,
716 					   &rt)) != 0)
717 				log(LOG_ERR,
718 				    "nd6_lookup: failed to add route for a "
719 				    "neighbor(%s), errno=%d\n",
720 				    ip6_sprintf(addr6), e);
721 			if (rt == NULL)
722 				return(NULL);
723 			if (rt->rt_llinfo) {
724 				struct llinfo_nd6 *ln =
725 					(struct llinfo_nd6 *)rt->rt_llinfo;
726 				ln->ln_state = ND6_LLINFO_NOSTATE;
727 			}
728 		} else
729 			return(NULL);
730 	}
731 	rt->rt_refcnt--;
732 	/*
733 	 * Validation for the entry.
734 	 * XXX: we can't use rt->rt_ifp to check for the interface, since
735 	 *      it might be the loopback interface if the entry is for our
736 	 *      own address on a non-loopback interface. Instead, we should
737 	 *      use rt->rt_ifa->ifa_ifp, which would specify the REAL interface.
738 	 */
739 	if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 ||
740 	    rt->rt_gateway->sa_family != AF_LINK ||
741 	    (ifp && rt->rt_ifa->ifa_ifp != ifp)) {
742 		if (create) {
743 			log(LOG_DEBUG, "nd6_lookup: failed to lookup %s (if = %s)\n",
744 			    ip6_sprintf(addr6), ifp ? if_name(ifp) : "unspec");
745 			/* xxx more logs... kazu */
746 		}
747 		return(0);
748 	}
749 	return(rt);
750 }
751 
752 /*
753  * Detect if a given IPv6 address identifies a neighbor on a given link.
754  * XXX: should take care of the destination of a p2p link?
755  */
756 int
757 nd6_is_addr_neighbor(addr, ifp)
758 	struct sockaddr_in6 *addr;
759 	struct ifnet *ifp;
760 {
761 	struct ifaddr *ifa;
762 	int i;
763 
764 #define IFADDR6(a) ((((struct in6_ifaddr *)(a))->ia_addr).sin6_addr)
765 #define IFMASK6(a) ((((struct in6_ifaddr *)(a))->ia_prefixmask).sin6_addr)
766 
767 	/*
768 	 * A link-local address is always a neighbor.
769 	 * XXX: we should use the sin6_scope_id field rather than the embedded
770 	 * interface index.
771 	 */
772 	if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr) &&
773 	    ntohs(*(u_int16_t *)&addr->sin6_addr.s6_addr[2]) == ifp->if_index)
774 		return(1);
775 
776 	/*
777 	 * If the address matches one of our addresses,
778 	 * it should be a neighbor.
779 	 */
780 	for (ifa = ifp->if_addrlist.tqh_first;
781 	     ifa;
782 	     ifa = ifa->ifa_list.tqe_next)
783 	{
784 		if (ifa->ifa_addr->sa_family != AF_INET6)
785 			next: continue;
786 
787 		for (i = 0; i < 4; i++) {
788 			if ((IFADDR6(ifa).s6_addr32[i] ^
789 			     addr->sin6_addr.s6_addr32[i]) &
790 			    IFMASK6(ifa).s6_addr32[i])
791 				goto next;
792 		}
793 		return(1);
794 	}
795 
796 	/*
797 	 * Even if the address matches none of our addresses, it might be
798 	 * in the neighbor cache.
799 	 */
800 	if (nd6_lookup(&addr->sin6_addr, 0, ifp))
801 		return(1);
802 
803 	return(0);
804 #undef IFADDR6
805 #undef IFMASK6
806 }
807 
808 /*
809  * Free an nd6 llinfo entry.
810  */
811 struct llinfo_nd6 *
812 nd6_free(rt)
813 	struct rtentry *rt;
814 {
815 	struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo, *next;
816 	struct in6_addr in6 = ((struct sockaddr_in6 *)rt_key(rt))->sin6_addr;
817 	struct nd_defrouter *dr;
818 
819 	/*
820 	 * Clear all destination cache entries for the neighbor.
821 	 * XXX: is it better to restrict this to hosts?
822 	 */
823 	pfctlinput(PRC_HOSTDEAD, rt_key(rt));
824 
825 	if (!ip6_forwarding && ip6_accept_rtadv) { /* XXX: too restrictive? */
826 		int s;
827 		s = splsoftnet();
828 		dr = defrouter_lookup(&((struct sockaddr_in6 *)rt_key(rt))->sin6_addr,
829 				      rt->rt_ifp);
830 		if (ln->ln_router || dr) {
831 			/*
832 			 * rt6_flush must be called whether or not the neighbor
833 			 * is in the Default Router List.
834 			 * See a corresponding comment in nd6_na_input().
835 			 */
836 			rt6_flush(&in6, rt->rt_ifp);
837 		}
838 
839 		if (dr) {
840 			/*
841 			 * Unreachablity of a router might affect the default
842 			 * router selection and on-link detection of advertised
843 			 * prefixes.
844 			 */
845 
846 			/*
847 			 * Temporarily fake the state to choose a new default
848 			 * router and to perform on-link determination of
849 			 * prefixes coreectly.
850 			 * Below the state will be set correctly,
851 			 * or the entry itself will be deleted.
852 			 */
853 			ln->ln_state = ND6_LLINFO_INCOMPLETE;
854 
855 			if (dr == TAILQ_FIRST(&nd_defrouter)) {
856 				/*
857 				 * It is used as the current default router,
858 				 * so we have to move it to the end of the
859 				 * list and choose a new one.
860 				 * XXX: it is not very efficient if this is
861 				 *      the only router.
862 				 */
863 				TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
864 				TAILQ_INSERT_TAIL(&nd_defrouter, dr, dr_entry);
865 
866 				defrouter_select();
867 			}
868 			pfxlist_onlink_check();
869 		}
870 		splx(s);
871 	}
872 
873 	/*
874 	 * Before deleting the entry, remember the next entry as the
875 	 * return value.  We need this because pfxlist_onlink_check() above
876 	 * might have freed other entries (particularly the old next entry) as
877 	 * a side effect (XXX).
878 	 */
879 	next = ln->ln_next;
880 
881 	/*
882 	 * Detach the route from the routing tree and the list of neighbor
883 	 * caches, and disable the route entry not to be used in already
884 	 * cached routes.
885 	 */
886 	rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0,
887 		  rt_mask(rt), 0, (struct rtentry **)0);
888 
889 	return(next);
890 }
891 
892 /*
893  * Upper-layer reachability hint for Neighbor Unreachability Detection.
894  *
895  * XXX cost-effective metods?
896  */
897 void
898 nd6_nud_hint(rt, dst6, force)
899 	struct rtentry *rt;
900 	struct in6_addr *dst6;
901 	int force;
902 {
903 	struct llinfo_nd6 *ln;
904 	long time_second = time.tv_sec;
905 
906 	/*
907 	 * If the caller specified "rt", use that.  Otherwise, resolve the
908 	 * routing table by supplied "dst6".
909 	 */
910 	if (!rt) {
911 		if (!dst6)
912 			return;
913 		if (!(rt = nd6_lookup(dst6, 0, NULL)))
914 			return;
915 	}
916 
917 	if ((rt->rt_flags & RTF_GATEWAY) != 0 ||
918 	    (rt->rt_flags & RTF_LLINFO) == 0 ||
919 	    !rt->rt_llinfo || !rt->rt_gateway ||
920 	    rt->rt_gateway->sa_family != AF_LINK) {
921 		/* This is not a host route. */
922 		return;
923 	}
924 
925 	ln = (struct llinfo_nd6 *)rt->rt_llinfo;
926 	if (ln->ln_state < ND6_LLINFO_REACHABLE)
927 		return;
928 
929 	/*
930 	 * if we get upper-layer reachability confirmation many times,
931 	 * it is possible we have false information.
932 	 */
933 	if (!force) {
934 		ln->ln_byhint++;
935 		if (ln->ln_byhint > nd6_maxnudhint)
936 			return;
937 	}
938 
939 	ln->ln_state = ND6_LLINFO_REACHABLE;
940 	if (ln->ln_expire)
941 		ln->ln_expire = time_second +
942 			nd_ifinfo[rt->rt_ifp->if_index].reachable;
943 }
944 
945 #ifdef OLDIP6OUTPUT
946 /*
947  * Resolve an IP6 address into an ethernet address. If success,
948  * desten is filled in. If there is no entry in ndptab,
949  * set one up and multicast a solicitation for the IP6 address.
950  * Hold onto this mbuf and resend it once the address
951  * is finally resolved. A return value of 1 indicates
952  * that desten has been filled in and the packet should be sent
953  * normally; a 0 return indicates that the packet has been
954  * taken over here, either now or for later transmission.
955  */
956 int
957 nd6_resolve(ifp, rt, m, dst, desten)
958 	struct ifnet *ifp;
959 	struct rtentry *rt;
960 	struct mbuf *m;
961 	struct sockaddr *dst;
962 	u_char *desten;
963 {
964 	struct llinfo_nd6 *ln = (struct llinfo_nd6 *)NULL;
965 	struct sockaddr_dl *sdl;
966 	long time_second = time.tv_sec;
967 
968 	if (m->m_flags & M_MCAST) {
969 		switch (ifp->if_type) {
970 		case IFT_ETHER:
971 		case IFT_FDDI:
972 			ETHER_MAP_IPV6_MULTICAST(&SIN6(dst)->sin6_addr,
973 						 desten);
974 			return(1);
975 		case IFT_IEEE1394:
976 			bcopy(ifp->if_broadcastaddr, desten, ifp->if_addrlen);
977 			return(1);
978 		case IFT_ARCNET:
979 			*desten = 0;
980 			return(1);
981 		default:
982 			m_freem(m);
983 			return(0);
984 		}
985 	}
986 	if (rt && (rt->rt_flags & RTF_LLINFO) != 0)
987 		ln = (struct llinfo_nd6 *)rt->rt_llinfo;
988 	else {
989 		if ((rt = nd6_lookup(&(SIN6(dst)->sin6_addr), 1, ifp)) != NULL)
990 			ln = (struct llinfo_nd6 *)rt->rt_llinfo;
991 	}
992 	if (!ln || !rt) {
993 		log(LOG_DEBUG, "nd6_resolve: can't allocate llinfo for %s\n",
994 			ip6_sprintf(&(SIN6(dst)->sin6_addr)));
995 		m_freem(m);
996 		return(0);
997 	}
998 	sdl = SDL(rt->rt_gateway);
999 	/*
1000 	 * Ckeck the address family and length is valid, the address
1001 	 * is resolved; otherwise, try to resolve.
1002 	 */
1003 	if (ln->ln_state >= ND6_LLINFO_REACHABLE
1004 	   && sdl->sdl_family == AF_LINK
1005 	   && sdl->sdl_alen != 0) {
1006 		bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
1007 		if (ln->ln_state == ND6_LLINFO_STALE) {
1008 			ln->ln_asked = 0;
1009 			ln->ln_state = ND6_LLINFO_DELAY;
1010 			ln->ln_expire = time_second + nd6_delay;
1011 		}
1012 		return(1);
1013 	}
1014 	/*
1015 	 * There is an ndp entry, but no ethernet address
1016 	 * response yet. Replace the held mbuf with this
1017 	 * latest one.
1018 	 *
1019 	 * XXX Does the code conform to rate-limiting rule?
1020 	 * (RFC 2461 7.2.2)
1021 	 */
1022 	if (ln->ln_state == ND6_LLINFO_NOSTATE)
1023 		ln->ln_state = ND6_LLINFO_INCOMPLETE;
1024 	if (ln->ln_hold)
1025 		m_freem(ln->ln_hold);
1026 	ln->ln_hold = m;
1027 	if (ln->ln_expire) {
1028 		if (ln->ln_asked < nd6_mmaxtries &&
1029 		    ln->ln_expire < time_second) {
1030 			ln->ln_asked++;
1031 			ln->ln_expire = time_second +
1032 				nd_ifinfo[ifp->if_index].retrans / 1000;
1033 			nd6_ns_output(ifp, NULL, &(SIN6(dst)->sin6_addr),
1034 				ln, 0);
1035 		}
1036 	}
1037 	/* do not free mbuf here, it is queued into llinfo_nd6 */
1038 	return(0);
1039 }
1040 #endif /* OLDIP6OUTPUT */
1041 
1042 void
1043 nd6_rtrequest(req, rt, info)
1044 	int	req;
1045 	struct rtentry *rt;
1046 	struct rt_addrinfo *info; /* xxx unused */
1047 {
1048 	struct sockaddr *gate = rt->rt_gateway;
1049 	struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1050 	static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
1051 	struct ifnet *ifp = rt->rt_ifp;
1052 	struct ifaddr *ifa;
1053 	long time_second = time.tv_sec;
1054 
1055 	if (rt->rt_flags & RTF_GATEWAY)
1056 		return;
1057 
1058 	switch (req) {
1059 	case RTM_ADD:
1060 		/*
1061 		 * There is no backward compatibility :)
1062 		 *
1063 		 * if ((rt->rt_flags & RTF_HOST) == 0 &&
1064 		 *     SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff)
1065 		 *	   rt->rt_flags |= RTF_CLONING;
1066 		 */
1067 		if (rt->rt_flags & (RTF_CLONING | RTF_LLINFO)) {
1068 			/*
1069 			 * Case 1: This route should come from
1070 			 * a route to interface. RTF_LLINFO flag is set
1071 			 * for a host route whose destination should be
1072 			 * treated as on-link.
1073 			 */
1074 			rt_setgate(rt, rt_key(rt),
1075 				   (struct sockaddr *)&null_sdl);
1076 			gate = rt->rt_gateway;
1077 			SDL(gate)->sdl_type = ifp->if_type;
1078 			SDL(gate)->sdl_index = ifp->if_index;
1079 			if (ln)
1080 				ln->ln_expire = time_second;
1081 #if 1
1082 			if (ln && ln->ln_expire == 0) {
1083 				/* kludge for desktops */
1084 #if 0
1085 				printf("nd6_request: time.tv_sec is zero; "
1086 				       "treat it as 1\n");
1087 #endif
1088 				ln->ln_expire = 1;
1089 			}
1090 #endif
1091 			if (rt->rt_flags & RTF_CLONING)
1092 				break;
1093 		}
1094 		/*
1095 		 * In IPv4 code, we try to annonuce new RTF_ANNOUNCE entry here.
1096 		 * We don't do that here since llinfo is not ready yet.
1097 		 *
1098 		 * There are also couple of other things to be discussed:
1099 		 * - unsolicited NA code needs improvement beforehand
1100 		 * - RFC2461 says we MAY send multicast unsolicited NA
1101 		 *   (7.2.6 paragraph 4), however, it also says that we
1102 		 *   SHOULD provide a mechanism to prevent multicast NA storm.
1103 		 *   we don't have anything like it right now.
1104 		 *   note that the mechanism needs a mutual agreement
1105 		 *   between proxies, which means that we need to implement
1106 		 *   a new protocol, or a new kludge.
1107 		 * - from RFC2461 6.2.4, host MUST NOT send an unsolicited NA.
1108 		 *   we need to check ip6forwarding before sending it.
1109 		 *   (or should we allow proxy ND configuration only for
1110 		 *   routers?  there's no mention about proxy ND from hosts)
1111 		 */
1112 #if 0
1113 		/* XXX it does not work */
1114 		if (rt->rt_flags & RTF_ANNOUNCE)
1115 			nd6_na_output(ifp,
1116 			      &SIN6(rt_key(rt))->sin6_addr,
1117 			      &SIN6(rt_key(rt))->sin6_addr,
1118 			      ip6_forwarding ? ND_NA_FLAG_ROUTER : 0,
1119 			      1, NULL);
1120 #endif
1121 		/* FALLTHROUGH */
1122 	case RTM_RESOLVE:
1123 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0) {
1124 			/*
1125 			 * Address resolution isn't necessary for a point to
1126 			 * point link, so we can skip this test for a p2p link.
1127 			 */
1128 			if (gate->sa_family != AF_LINK ||
1129 			    gate->sa_len < sizeof(null_sdl)) {
1130 				log(LOG_DEBUG,
1131 				    "nd6_rtrequest: bad gateway value: %s\n",
1132 				    if_name(ifp));
1133 				break;
1134 			}
1135 			SDL(gate)->sdl_type = ifp->if_type;
1136 			SDL(gate)->sdl_index = ifp->if_index;
1137 		}
1138 		if (ln != NULL)
1139 			break;	/* This happens on a route change */
1140 		/*
1141 		 * Case 2: This route may come from cloning, or a manual route
1142 		 * add with a LL address.
1143 		 */
1144 		R_Malloc(ln, struct llinfo_nd6 *, sizeof(*ln));
1145 		rt->rt_llinfo = (caddr_t)ln;
1146 		if (!ln) {
1147 			log(LOG_DEBUG, "nd6_rtrequest: malloc failed\n");
1148 			break;
1149 		}
1150 		nd6_inuse++;
1151 		nd6_allocated++;
1152 		Bzero(ln, sizeof(*ln));
1153 		ln->ln_rt = rt;
1154 		/* this is required for "ndp" command. - shin */
1155 		if (req == RTM_ADD) {
1156 		        /*
1157 			 * gate should have some valid AF_LINK entry,
1158 			 * and ln->ln_expire should have some lifetime
1159 			 * which is specified by ndp command.
1160 			 */
1161 			ln->ln_state = ND6_LLINFO_REACHABLE;
1162 			ln->ln_byhint = 0;
1163 		} else {
1164 		        /*
1165 			 * When req == RTM_RESOLVE, rt is created and
1166 			 * initialized in rtrequest(), so rt_expire is 0.
1167 			 */
1168 			ln->ln_state = ND6_LLINFO_NOSTATE;
1169 			ln->ln_expire = time_second;
1170 		}
1171 		rt->rt_flags |= RTF_LLINFO;
1172 		ln->ln_next = llinfo_nd6.ln_next;
1173 		llinfo_nd6.ln_next = ln;
1174 		ln->ln_prev = &llinfo_nd6;
1175 		ln->ln_next->ln_prev = ln;
1176 
1177 		/*
1178 		 * check if rt_key(rt) is one of my address assigned
1179 		 * to the interface.
1180 		 */
1181 		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(rt->rt_ifp,
1182 					  &SIN6(rt_key(rt))->sin6_addr);
1183 		if (ifa) {
1184 			caddr_t macp = nd6_ifptomac(ifp);
1185 			ln->ln_expire = 0;
1186 			ln->ln_state = ND6_LLINFO_REACHABLE;
1187 			ln->ln_byhint = 0;
1188 			if (macp) {
1189 				Bcopy(macp, LLADDR(SDL(gate)), ifp->if_addrlen);
1190 				SDL(gate)->sdl_alen = ifp->if_addrlen;
1191 			}
1192 			if (nd6_useloopback) {
1193 				rt->rt_ifp = &loif[0];	/*XXX*/
1194 				/*
1195 				 * Make sure rt_ifa be equal to the ifaddr
1196 				 * corresponding to the address.
1197 				 * We need this because when we refer
1198 				 * rt_ifa->ia6_flags in ip6_input, we assume
1199 				 * that the rt_ifa points to the address instead
1200 				 * of the loopback address.
1201 				 */
1202 				if (ifa != rt->rt_ifa) {
1203 					IFAFREE(rt->rt_ifa);
1204 					IFAREF(ifa);
1205 					rt->rt_ifa = ifa;
1206 				}
1207 			}
1208 		} else if (rt->rt_flags & RTF_ANNOUNCE) {
1209 			ln->ln_expire = 0;
1210 			ln->ln_state = ND6_LLINFO_REACHABLE;
1211 			ln->ln_byhint = 0;
1212 
1213 			/* join solicited node multicast for proxy ND */
1214 			if (ifp->if_flags & IFF_MULTICAST) {
1215 				struct in6_addr llsol;
1216 				int error;
1217 
1218 				llsol = SIN6(rt_key(rt))->sin6_addr;
1219 				llsol.s6_addr16[0] = htons(0xff02);
1220 				llsol.s6_addr16[1] = htons(ifp->if_index);
1221 				llsol.s6_addr32[1] = 0;
1222 				llsol.s6_addr32[2] = htonl(1);
1223 				llsol.s6_addr8[12] = 0xff;
1224 
1225 				if (!in6_addmulti(&llsol, ifp, &error)) {
1226 					nd6log((LOG_ERR, "%s: "
1227 					    "failed to join %s (errno=%d)\n",
1228 					    if_name(ifp), ip6_sprintf(&llsol),
1229 					    error));
1230 				}
1231 			}
1232 		}
1233 		break;
1234 
1235 	case RTM_DELETE:
1236 		if (!ln)
1237 			break;
1238 		/* leave from solicited node multicast for proxy ND */
1239 		if ((rt->rt_flags & RTF_ANNOUNCE) != 0 &&
1240 		    (ifp->if_flags & IFF_MULTICAST) != 0) {
1241 			struct in6_addr llsol;
1242 			struct in6_multi *in6m;
1243 
1244 			llsol = SIN6(rt_key(rt))->sin6_addr;
1245 			llsol.s6_addr16[0] = htons(0xff02);
1246 			llsol.s6_addr16[1] = htons(ifp->if_index);
1247 			llsol.s6_addr32[1] = 0;
1248 			llsol.s6_addr32[2] = htonl(1);
1249 			llsol.s6_addr8[12] = 0xff;
1250 
1251 			IN6_LOOKUP_MULTI(llsol, ifp, in6m);
1252 			if (in6m)
1253 				in6_delmulti(in6m);
1254 		}
1255 		nd6_inuse--;
1256 		ln->ln_next->ln_prev = ln->ln_prev;
1257 		ln->ln_prev->ln_next = ln->ln_next;
1258 		ln->ln_prev = NULL;
1259 		rt->rt_llinfo = 0;
1260 		rt->rt_flags &= ~RTF_LLINFO;
1261 		if (ln->ln_hold)
1262 			m_freem(ln->ln_hold);
1263 		Free((caddr_t)ln);
1264 	}
1265 }
1266 
1267 void
1268 nd6_p2p_rtrequest(req, rt, info)
1269 	int	req;
1270 	struct rtentry *rt;
1271 	struct rt_addrinfo *info; /* xxx unused */
1272 {
1273 	struct sockaddr *gate = rt->rt_gateway;
1274 	static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
1275 	struct ifnet *ifp = rt->rt_ifp;
1276 	struct ifaddr *ifa;
1277 
1278 	if (rt->rt_flags & RTF_GATEWAY)
1279 		return;
1280 
1281 	switch (req) {
1282 	case RTM_ADD:
1283 		/*
1284 		 * There is no backward compatibility :)
1285 		 *
1286 		 * if ((rt->rt_flags & RTF_HOST) == 0 &&
1287 		 *     SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff)
1288 		 *	   rt->rt_flags |= RTF_CLONING;
1289 		 */
1290 		if (rt->rt_flags & RTF_CLONING) {
1291 			/*
1292 			 * Case 1: This route should come from
1293 			 * a route to interface.
1294 			 */
1295 			rt_setgate(rt, rt_key(rt),
1296 				   (struct sockaddr *)&null_sdl);
1297 			gate = rt->rt_gateway;
1298 			SDL(gate)->sdl_type = ifp->if_type;
1299 			SDL(gate)->sdl_index = ifp->if_index;
1300 			break;
1301 		}
1302 		/* Announce a new entry if requested. */
1303 		if (rt->rt_flags & RTF_ANNOUNCE)
1304 			nd6_na_output(ifp,
1305 				      &SIN6(rt_key(rt))->sin6_addr,
1306 				      &SIN6(rt_key(rt))->sin6_addr,
1307 				      ip6_forwarding ? ND_NA_FLAG_ROUTER : 0,
1308 				      1, NULL);
1309 		/* FALLTHROUGH */
1310 	case RTM_RESOLVE:
1311 		/*
1312 		 * check if rt_key(rt) is one of my address assigned
1313 		 * to the interface.
1314 		 */
1315  		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(rt->rt_ifp,
1316 					  &SIN6(rt_key(rt))->sin6_addr);
1317 		if (ifa) {
1318 			if (nd6_useloopback) {
1319 				rt->rt_ifp = &loif[0];	/*XXX*/
1320 			}
1321 		}
1322 		break;
1323 	}
1324 }
1325 
1326 int
1327 nd6_ioctl(cmd, data, ifp)
1328 	u_long cmd;
1329 	caddr_t	data;
1330 	struct ifnet *ifp;
1331 {
1332 	struct in6_drlist *drl = (struct in6_drlist *)data;
1333 	struct in6_prlist *prl = (struct in6_prlist *)data;
1334 	struct in6_ndireq *ndi = (struct in6_ndireq *)data;
1335 	struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data;
1336 	struct in6_ndifreq *ndif = (struct in6_ndifreq *)data;
1337 	struct nd_defrouter *dr, any;
1338 	struct nd_prefix *pr;
1339 	struct rtentry *rt;
1340 	int i = 0, error = 0;
1341 	int s;
1342 
1343 	switch (cmd) {
1344 	case SIOCGDRLST_IN6:
1345 		bzero(drl, sizeof(*drl));
1346 		s = splsoftnet();
1347 		dr = TAILQ_FIRST(&nd_defrouter);
1348 		while (dr && i < DRLSTSIZ) {
1349 			drl->defrouter[i].rtaddr = dr->rtaddr;
1350 			if (IN6_IS_ADDR_LINKLOCAL(&drl->defrouter[i].rtaddr)) {
1351 				/* XXX: need to this hack for KAME stack */
1352 				drl->defrouter[i].rtaddr.s6_addr16[1] = 0;
1353 			} else
1354 				log(LOG_ERR,
1355 				    "default router list contains a "
1356 				    "non-linklocal address(%s)\n",
1357 				    ip6_sprintf(&drl->defrouter[i].rtaddr));
1358 
1359 			drl->defrouter[i].flags = dr->flags;
1360 			drl->defrouter[i].rtlifetime = dr->rtlifetime;
1361 			drl->defrouter[i].expire = dr->expire;
1362 			drl->defrouter[i].if_index = dr->ifp->if_index;
1363 			i++;
1364 			dr = TAILQ_NEXT(dr, dr_entry);
1365 		}
1366 		splx(s);
1367 		break;
1368 	case SIOCGPRLST_IN6:
1369 		/*
1370 		 * XXX meaning of fields, especialy "raflags", is very
1371 		 * differnet between RA prefix list and RR/static prefix list.
1372 		 * how about separating ioctls into two?
1373 		 */
1374 		bzero(prl, sizeof(*prl));
1375 		s = splsoftnet();
1376 		pr = nd_prefix.lh_first;
1377 		while (pr && i < PRLSTSIZ) {
1378 			struct nd_pfxrouter *pfr;
1379 			int j;
1380 
1381 			prl->prefix[i].prefix = pr->ndpr_prefix.sin6_addr;
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 			prl->prefix[i].prefix = rpp->rp_prefix.sin6_addr;
1423 			prl->prefix[i].raflags = rpp->rp_raf;
1424 			prl->prefix[i].prefixlen = rpp->rp_plen;
1425 			prl->prefix[i].vltime = rpp->rp_vltime;
1426 			prl->prefix[i].pltime = rpp->rp_pltime;
1427 			prl->prefix[i].if_index = rpp->rp_ifp->if_index;
1428 			prl->prefix[i].expire = rpp->rp_expire;
1429 			prl->prefix[i].advrtrs = 0;
1430 			prl->prefix[i].origin = rpp->rp_origin;
1431 			i++;
1432 		}
1433 	      }
1434 		splx(s);
1435 
1436 		break;
1437 	case SIOCGIFINFO_IN6:
1438 		if (!nd_ifinfo || i >= nd_ifinfo_indexlim) {
1439 			error = EINVAL;
1440 			break;
1441 		}
1442 		ndi->ndi = nd_ifinfo[ifp->if_index];
1443 		break;
1444 	case SIOCSIFINFO_FLAGS:
1445 		/* XXX: almost all other fields of ndi->ndi is unused */
1446 		if (!nd_ifinfo || i >= nd_ifinfo_indexlim) {
1447 			error = EINVAL;
1448 			break;
1449 		}
1450 		nd_ifinfo[ifp->if_index].flags = ndi->ndi.flags;
1451 		break;
1452 	case SIOCSNDFLUSH_IN6:	/* XXX: the ioctl name is confusing... */
1453 		/* flush default router list */
1454 		/*
1455 		 * xxx sumikawa: should not delete route if default
1456 		 * route equals to the top of default router list
1457 		 */
1458 		bzero(&any, sizeof(any));
1459 		defrouter_delreq(&any, 0);
1460 		defrouter_select();
1461 		/* xxx sumikawa: flush prefix list */
1462 		break;
1463 	case SIOCSPFXFLUSH_IN6:
1464 	    {
1465 		/* flush all the prefix advertised by routers */
1466 		struct nd_prefix *pr, *next;
1467 
1468 		s = splsoftnet();
1469 		for (pr = nd_prefix.lh_first; pr; pr = next) {
1470 			next = pr->ndpr_next;
1471 			if (!IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr))
1472 				in6_ifdel(pr->ndpr_ifp, &pr->ndpr_addr);
1473 			prelist_remove(pr);
1474 		}
1475 		splx(s);
1476 		break;
1477 	    }
1478 	case SIOCSRTRFLUSH_IN6:
1479 	    {
1480 		/* flush all the default routers */
1481 		struct nd_defrouter *dr, *next;
1482 
1483 		s = splsoftnet();
1484 		if ((dr = TAILQ_FIRST(&nd_defrouter)) != NULL) {
1485 			/*
1486 			 * The first entry of the list may be stored in
1487 			 * the routing table, so we'll delete it later.
1488 			 */
1489 			for (dr = TAILQ_NEXT(dr, dr_entry); dr; dr = next) {
1490 				next = TAILQ_NEXT(dr, dr_entry);
1491 				defrtrlist_del(dr);
1492 			}
1493 			defrtrlist_del(TAILQ_FIRST(&nd_defrouter));
1494 		}
1495 		splx(s);
1496 		break;
1497 	    }
1498 	case SIOCGNBRINFO_IN6:
1499 	    {
1500 		struct llinfo_nd6 *ln;
1501 		struct in6_addr nb_addr = nbi->addr; /* make local for safety */
1502 
1503 		/*
1504 		 * XXX: KAME specific hack for scoped addresses
1505 		 *      XXXX: for other scopes than link-local?
1506 		 */
1507 		if (IN6_IS_ADDR_LINKLOCAL(&nbi->addr) ||
1508 		    IN6_IS_ADDR_MC_LINKLOCAL(&nbi->addr)) {
1509 			u_int16_t *idp = (u_int16_t *)&nb_addr.s6_addr[2];
1510 
1511 			if (*idp == 0)
1512 				*idp = htons(ifp->if_index);
1513 		}
1514 
1515 		s = splsoftnet();
1516 		if ((rt = nd6_lookup(&nb_addr, 0, ifp)) == NULL) {
1517 			error = EINVAL;
1518 			splx(s);
1519 			break;
1520 		}
1521 		ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1522 		nbi->state = ln->ln_state;
1523 		nbi->asked = ln->ln_asked;
1524 		nbi->isrouter = ln->ln_router;
1525 		nbi->expire = ln->ln_expire;
1526 		splx(s);
1527 
1528 		break;
1529 	    }
1530 	case SIOCGDEFIFACE_IN6:	/* XXX: should be implemented as a sysctl? */
1531 		ndif->ifindex = nd6_defifindex;
1532 		break;
1533 	case SIOCSDEFIFACE_IN6:	/* XXX: should be implemented as a sysctl? */
1534 		return(nd6_setdefaultiface(ndif->ifindex));
1535 		break;
1536 	}
1537 	return(error);
1538 }
1539 
1540 /*
1541  * Create neighbor cache entry and cache link-layer address,
1542  * on reception of inbound ND6 packets. (RS/RA/NS/redirect)
1543  */
1544 struct rtentry *
1545 nd6_cache_lladdr(ifp, from, lladdr, lladdrlen, type, code)
1546 	struct ifnet *ifp;
1547 	struct in6_addr *from;
1548 	char *lladdr;
1549 	int lladdrlen;
1550 	int type;	/* ICMP6 type */
1551 	int code;	/* type dependent information */
1552 {
1553 	struct rtentry *rt = NULL;
1554 	struct llinfo_nd6 *ln = NULL;
1555 	int is_newentry;
1556 	struct sockaddr_dl *sdl = NULL;
1557 	int do_update;
1558 	int olladdr;
1559 	int llchange;
1560 	int newstate = 0;
1561 	long time_second = time.tv_sec;
1562 
1563 	if (!ifp)
1564 		panic("ifp == NULL in nd6_cache_lladdr");
1565 	if (!from)
1566 		panic("from == NULL in nd6_cache_lladdr");
1567 
1568 	/* nothing must be updated for unspecified address */
1569 	if (IN6_IS_ADDR_UNSPECIFIED(from))
1570 		return NULL;
1571 
1572 	/*
1573 	 * Validation about ifp->if_addrlen and lladdrlen must be done in
1574 	 * the caller.
1575 	 *
1576 	 * XXX If the link does not have link-layer adderss, what should
1577 	 * we do? (ifp->if_addrlen == 0)
1578 	 * Spec says nothing in sections for RA, RS and NA.  There's small
1579 	 * description on it in NS section (RFC 2461 7.2.3).
1580 	 */
1581 
1582 	rt = nd6_lookup(from, 0, ifp);
1583 	if (!rt) {
1584 #if 0
1585 		/* nothing must be done if there's no lladdr */
1586 		if (!lladdr || !lladdrlen)
1587 			return NULL;
1588 #endif
1589 
1590 		rt = nd6_lookup(from, 1, ifp);
1591 		is_newentry = 1;
1592 	} else {
1593 		/* do nothing if static ndp is set */
1594 		if (rt->rt_flags & RTF_STATIC)
1595 			return NULL;
1596 		is_newentry = 0;
1597 	}
1598 
1599 	if (!rt)
1600 		return NULL;
1601 	if ((rt->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) != RTF_LLINFO) {
1602 fail:
1603 		(void)nd6_free(rt);
1604 		return NULL;
1605 	}
1606 	ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1607 	if (!ln)
1608 		goto fail;
1609 	if (!rt->rt_gateway)
1610 		goto fail;
1611 	if (rt->rt_gateway->sa_family != AF_LINK)
1612 		goto fail;
1613 	sdl = SDL(rt->rt_gateway);
1614 
1615 	olladdr = (sdl->sdl_alen) ? 1 : 0;
1616 	if (olladdr && lladdr) {
1617 		if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen))
1618 			llchange = 1;
1619 		else
1620 			llchange = 0;
1621 	} else
1622 		llchange = 0;
1623 
1624 	/*
1625 	 * newentry olladdr  lladdr  llchange	(*=record)
1626 	 *	0	n	n	--	(1)
1627 	 *	0	y	n	--	(2)
1628 	 *	0	n	y	--	(3) * STALE
1629 	 *	0	y	y	n	(4) *
1630 	 *	0	y	y	y	(5) * STALE
1631 	 *	1	--	n	--	(6)   NOSTATE(= PASSIVE)
1632 	 *	1	--	y	--	(7) * STALE
1633 	 */
1634 
1635 	if (lladdr) {		/*(3-5) and (7)*/
1636 		/*
1637 		 * Record source link-layer address
1638 		 * XXX is it dependent to ifp->if_type?
1639 		 */
1640 		sdl->sdl_alen = ifp->if_addrlen;
1641 		bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen);
1642 	}
1643 
1644 	if (!is_newentry) {
1645 		if ((!olladdr && lladdr)		/*(3)*/
1646 		 || (olladdr && lladdr && llchange)) {	/*(5)*/
1647 			do_update = 1;
1648 			newstate = ND6_LLINFO_STALE;
1649 		} else					/*(1-2,4)*/
1650 			do_update = 0;
1651 	} else {
1652 		do_update = 1;
1653 		if (!lladdr)				/*(6)*/
1654 			newstate = ND6_LLINFO_NOSTATE;
1655 		else					/*(7)*/
1656 			newstate = ND6_LLINFO_STALE;
1657 	}
1658 
1659 	if (do_update) {
1660 		/*
1661 		 * Update the state of the neighbor cache.
1662 		 */
1663 		ln->ln_state = newstate;
1664 
1665 		if (ln->ln_state == ND6_LLINFO_STALE) {
1666 			/*
1667 			 * XXX: since nd6_output() below will cause
1668 			 * state tansition to DELAY and reset the timer,
1669 			 * we must set the timer now, although it is actually
1670 			 * meaningless.
1671 			 */
1672 			ln->ln_expire = time_second + nd6_gctimer;
1673 
1674 			if (ln->ln_hold) {
1675 #ifdef OLDIP6OUTPUT
1676 				ln->ln_asked = 0;
1677 				ln->ln_state = ND6_LLINFO_DELAY;
1678 				ln->ln_expire = time_second + nd6_delay;
1679 				(*ifp->if_output)(ifp, ln->ln_hold,
1680 						  rt_key(rt), rt);
1681 #else
1682 				/*
1683 				 * we assume ifp is not a p2p here, so just
1684 				 * set the 2nd argument as the 1st one.
1685 				 */
1686 				nd6_output(ifp, ifp, ln->ln_hold,
1687 					   (struct sockaddr_in6 *)rt_key(rt),
1688 					   rt);
1689 #endif
1690 				ln->ln_hold = NULL;
1691 			}
1692 		} else if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
1693 			/* probe right away */
1694 			ln->ln_expire = time_second;
1695 		}
1696 	}
1697 
1698 	/*
1699 	 * ICMP6 type dependent behavior.
1700 	 *
1701 	 * NS: clear IsRouter if new entry
1702 	 * RS: clear IsRouter
1703 	 * RA: set IsRouter if there's lladdr
1704 	 * redir: clear IsRouter if new entry
1705 	 *
1706 	 * RA case, (1):
1707 	 * The spec says that we must set IsRouter in the following cases:
1708 	 * - If lladdr exist, set IsRouter.  This means (1-5).
1709 	 * - If it is old entry (!newentry), set IsRouter.  This means (7).
1710 	 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
1711 	 * A quetion arises for (1) case.  (1) case has no lladdr in the
1712 	 * neighbor cache, this is similar to (6).
1713 	 * This case is rare but we figured that we MUST NOT set IsRouter.
1714 	 *
1715 	 * newentry olladdr  lladdr  llchange	    NS  RS  RA	redir
1716 	 *							D R
1717 	 *	0	n	n	--	(1)	c   ?     s
1718 	 *	0	y	n	--	(2)	c   s     s
1719 	 *	0	n	y	--	(3)	c   s     s
1720 	 *	0	y	y	n	(4)	c   s     s
1721 	 *	0	y	y	y	(5)	c   s     s
1722 	 *	1	--	n	--	(6) c	c 	c s
1723 	 *	1	--	y	--	(7) c	c   s	c s
1724 	 *
1725 	 *					(c=clear s=set)
1726 	 */
1727 	switch (type & 0xff) {
1728 	case ND_NEIGHBOR_SOLICIT:
1729 		/*
1730 		 * New entry must have is_router flag cleared.
1731 		 */
1732 		if (is_newentry)	/*(6-7)*/
1733 			ln->ln_router = 0;
1734 		break;
1735 	case ND_REDIRECT:
1736 		/*
1737 		 * If the icmp is a redirect to a better router, always set the
1738 		 * is_router flag. Otherwise, if the entry is newly created,
1739 		 * clear the flag. [RFC 2461, sec 8.3]
1740 		 */
1741 		if (code == ND_REDIRECT_ROUTER)
1742 			ln->ln_router = 1;
1743 		else if (is_newentry) /*(6-7)*/
1744 			ln->ln_router = 0;
1745 		break;
1746 	case ND_ROUTER_SOLICIT:
1747 		/*
1748 		 * is_router flag must always be cleared.
1749 		 */
1750 		ln->ln_router = 0;
1751 		break;
1752 	case ND_ROUTER_ADVERT:
1753 		/*
1754 		 * Mark an entry with lladdr as a router.
1755 		 */
1756 		if ((!is_newentry && (olladdr || lladdr))	/*(2-5)*/
1757 		 || (is_newentry && lladdr)) {			/*(7)*/
1758 			ln->ln_router = 1;
1759 		}
1760 		break;
1761 	}
1762 
1763 	/*
1764 	 * When the link-layer address of a router changes, select the
1765 	 * best router again.  In particular, when the neighbor entry is newly
1766 	 * created, it might affect the selection policy.
1767 	 * Question: can we restrict the first condition to the "is_newentry"
1768 	 * case?
1769 	 * XXX: when we hear an RA from a new router with the link-layer
1770 	 * address option, defrouter_select() is called twice, since
1771 	 * defrtrlist_update called the function as well.  However, I believe
1772 	 * we can compromise the overhead, since it only happens the first
1773 	 * time.
1774 	 */
1775 	if (do_update && ln->ln_router && !ip6_forwarding && ip6_accept_rtadv)
1776 		defrouter_select();
1777 
1778 	return rt;
1779 }
1780 
1781 static void
1782 nd6_slowtimo(ignored_arg)
1783     void *ignored_arg;
1784 {
1785 	int s = splsoftnet();
1786 	int i;
1787 	struct nd_ifinfo *nd6if;
1788 
1789 	callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
1790 	    nd6_slowtimo, NULL);
1791 	for (i = 1; i < if_index + 1; i++) {
1792 		if (!nd_ifinfo || i >= nd_ifinfo_indexlim)
1793 			continue;
1794 		nd6if = &nd_ifinfo[i];
1795 		if (nd6if->basereachable && /* already initialized */
1796 		    (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
1797 			/*
1798 			 * Since reachable time rarely changes by router
1799 			 * advertisements, we SHOULD insure that a new random
1800 			 * value gets recomputed at least once every few hours.
1801 			 * (RFC 2461, 6.3.4)
1802 			 */
1803 			nd6if->recalctm = nd6_recalc_reachtm_interval;
1804 			nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable);
1805 		}
1806 	}
1807 	splx(s);
1808 }
1809 
1810 #define senderr(e) { error = (e); goto bad;}
1811 int
1812 nd6_output(ifp, origifp, m0, dst, rt0)
1813 	struct ifnet *ifp;
1814 	struct ifnet *origifp;
1815 	struct mbuf *m0;
1816 	struct sockaddr_in6 *dst;
1817 	struct rtentry *rt0;
1818 {
1819 	struct mbuf *m = m0;
1820 	struct rtentry *rt = rt0;
1821 	struct sockaddr_in6 *gw6 = NULL;
1822 	struct llinfo_nd6 *ln = NULL;
1823 	int error = 0;
1824 	long time_second = time.tv_sec;
1825 
1826 	if (IN6_IS_ADDR_MULTICAST(&dst->sin6_addr))
1827 		goto sendpkt;
1828 
1829 	/*
1830 	 * XXX: we currently do not make neighbor cache on any interface
1831 	 * other than ARCnet, Ethernet, FDDI and GIF.
1832 	 *
1833 	 * RFC2893 says:
1834 	 * - unidirectional tunnels needs no ND
1835 	 */
1836 	switch (ifp->if_type) {
1837 	case IFT_ARCNET:
1838 	case IFT_ETHER:
1839 	case IFT_FDDI:
1840 	case IFT_IEEE1394:
1841 	case IFT_GIF:		/* XXX need more cases? */
1842 		break;
1843 	default:
1844 		goto sendpkt;
1845 	}
1846 
1847 	/*
1848 	 * next hop determination. This routine is derived from ether_outpout.
1849 	 */
1850 	if (rt) {
1851 		if ((rt->rt_flags & RTF_UP) == 0) {
1852 			if ((rt0 = rt = rtalloc1((struct sockaddr *)dst, 1)) !=
1853 				NULL)
1854 			{
1855 				rt->rt_refcnt--;
1856 				if (rt->rt_ifp != ifp) {
1857 					/* XXX: loop care? */
1858 					return nd6_output(ifp, origifp, m0,
1859 							  dst, rt);
1860 				}
1861 			} else
1862 				senderr(EHOSTUNREACH);
1863 		}
1864 
1865 		if (rt->rt_flags & RTF_GATEWAY) {
1866 			gw6 = (struct sockaddr_in6 *)rt->rt_gateway;
1867 
1868 			/*
1869 			 * We skip link-layer address resolution and NUD
1870 			 * if the gateway is not a neighbor from ND point
1871 			 * of view, regardless the value of the
1872 			 * 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 == 0)
1891 				goto lookup;
1892 			if (((rt = rt->rt_gwroute)->rt_flags & RTF_UP) == 0) {
1893 				rtfree(rt); rt = rt0;
1894 			lookup:
1895 				rt->rt_gwroute = rtalloc1(rt->rt_gateway, 1);
1896 				if ((rt = rt->rt_gwroute) == 0)
1897 					senderr(EHOSTUNREACH);
1898 				/* the "G" test below also prevents rt == rt0 */
1899 				if ((rt->rt_flags & RTF_GATEWAY) ||
1900 				    (rt->rt_ifp != ifp)) {
1901 					rt->rt_refcnt--;
1902 					rt0->rt_gwroute = 0;
1903 					senderr(EHOSTUNREACH);
1904 				}
1905 			}
1906 		}
1907 	}
1908 
1909 	/*
1910 	 * Address resolution or Neighbor Unreachability Detection
1911 	 * for the next hop.
1912 	 * At this point, the destination of the packet must be a unicast
1913 	 * or an anycast address(i.e. not a multicast).
1914 	 */
1915 
1916 	/* Look up the neighbor cache for the nexthop */
1917 	if (rt && (rt->rt_flags & RTF_LLINFO) != 0)
1918 		ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1919 	else {
1920 		/*
1921 		 * Since nd6_is_addr_neighbor() internally calls nd6_lookup(),
1922 		 * the condition below is not very efficient. But we believe
1923 		 * it is tolerable, because this should be a rare case.
1924 		 */
1925 		if (nd6_is_addr_neighbor(dst, ifp) &&
1926 		    (rt = nd6_lookup(&dst->sin6_addr, 1, ifp)) != NULL)
1927 			ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1928 	}
1929 	if (!ln || !rt) {
1930 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0 &&
1931 		    !(nd_ifinfo[ifp->if_index].flags & ND6_IFF_PERFORMNUD)) {
1932 			log(LOG_DEBUG,
1933 			    "nd6_output: can't allocate llinfo for %s "
1934 			    "(ln=%p, rt=%p)\n",
1935 			    ip6_sprintf(&dst->sin6_addr), ln, rt);
1936 			senderr(EIO);	/* XXX: good error? */
1937 		}
1938 
1939 		goto sendpkt;	/* send anyway */
1940 	}
1941 
1942 	/* We don't have to do link-layer address resolution on a p2p link. */
1943 	if ((ifp->if_flags & IFF_POINTOPOINT) != 0 &&
1944 	    ln->ln_state < ND6_LLINFO_REACHABLE) {
1945 		ln->ln_state = ND6_LLINFO_STALE;
1946 		ln->ln_expire = time_second + nd6_gctimer;
1947 	}
1948 
1949 	/*
1950 	 * The first time we send a packet to a neighbor whose entry is
1951 	 * STALE, we have to change the state to DELAY and a sets a timer to
1952 	 * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do
1953 	 * neighbor unreachability detection on expiration.
1954 	 * (RFC 2461 7.3.3)
1955 	 */
1956 	if (ln->ln_state == ND6_LLINFO_STALE) {
1957 		ln->ln_asked = 0;
1958 		ln->ln_state = ND6_LLINFO_DELAY;
1959 		ln->ln_expire = time_second + nd6_delay;
1960 	}
1961 
1962 	/*
1963 	 * If the neighbor cache entry has a state other than INCOMPLETE
1964 	 * (i.e. its link-layer address is already reloved), just
1965 	 * send the packet.
1966 	 */
1967 	if (ln->ln_state > ND6_LLINFO_INCOMPLETE)
1968 		goto sendpkt;
1969 
1970 	/*
1971 	 * There is a neighbor cache entry, but no ethernet address
1972 	 * response yet. Replace the held mbuf (if any) with this
1973 	 * latest one.
1974 	 *
1975 	 * XXX Does the code conform to rate-limiting rule?
1976 	 * (RFC 2461 7.2.2)
1977 	 */
1978 	if (ln->ln_state == ND6_LLINFO_NOSTATE)
1979 		ln->ln_state = ND6_LLINFO_INCOMPLETE;
1980 	if (ln->ln_hold)
1981 		m_freem(ln->ln_hold);
1982 	ln->ln_hold = m;
1983 	if (ln->ln_expire) {
1984 		if (ln->ln_asked < nd6_mmaxtries &&
1985 		    ln->ln_expire < time_second) {
1986 			ln->ln_asked++;
1987 			ln->ln_expire = time_second +
1988 				nd_ifinfo[ifp->if_index].retrans / 1000;
1989 			nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0);
1990 		}
1991 	}
1992 	return(0);
1993 
1994   sendpkt:
1995 
1996 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
1997 		return((*ifp->if_output)(origifp, m, (struct sockaddr *)dst,
1998 					 rt));
1999 	}
2000 	return((*ifp->if_output)(ifp, m, (struct sockaddr *)dst, rt));
2001 
2002   bad:
2003 	if (m)
2004 		m_freem(m);
2005 	return (error);
2006 }
2007 #undef senderr
2008 
2009 int
2010 nd6_storelladdr(ifp, rt, m, dst, desten)
2011 	struct ifnet *ifp;
2012 	struct rtentry *rt;
2013 	struct mbuf *m;
2014 	struct sockaddr *dst;
2015 	u_char *desten;
2016 {
2017 	struct sockaddr_dl *sdl;
2018 
2019 	if (m->m_flags & M_MCAST) {
2020 		switch (ifp->if_type) {
2021 		case IFT_ETHER:
2022 		case IFT_FDDI:
2023 			ETHER_MAP_IPV6_MULTICAST(&SIN6(dst)->sin6_addr,
2024 						 desten);
2025 			return(1);
2026 		case IFT_IEEE1394:
2027 			bcopy(ifp->if_broadcastaddr, desten, ifp->if_addrlen);
2028 			return(1);
2029 		case IFT_ARCNET:
2030 			*desten = 0;
2031 			return(1);
2032 		default:
2033 			m_freem(m);
2034 			return(0);
2035 		}
2036 	}
2037 
2038 	if (rt == NULL) {
2039 		/* this could happen, if we could not allocate memory */
2040 		m_freem(m);
2041 		return(0);
2042 	}
2043 	if (rt->rt_gateway->sa_family != AF_LINK) {
2044 		printf("nd6_storelladdr: something odd happens\n");
2045 		m_freem(m);
2046 		return(0);
2047 	}
2048 	sdl = SDL(rt->rt_gateway);
2049 	if (sdl->sdl_alen == 0) {
2050 		/* this should be impossible, but we bark here for debugging */
2051 		printf("nd6_storelladdr: sdl_alen == 0\n");
2052 		m_freem(m);
2053 		return(0);
2054 	}
2055 
2056 	bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
2057 	return(1);
2058 }
2059