xref: /freebsd/sys/netinet6/nd6.c (revision 5129159789cc9d7bc514e4546b88e3427695002d)
1 /*
2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the project nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 /*
33  * XXX
34  * KAME 970409 note:
35  * BSD/OS version heavily modifies this code, related to llinfo.
36  * Since we don't have BSD/OS version of net/route.c in our hand,
37  * I left the code mostly as it was in 970310.  -- itojun
38  */
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/malloc.h>
43 #include <sys/mbuf.h>
44 #include <sys/socket.h>
45 #include <sys/sockio.h>
46 #include <sys/time.h>
47 #include <sys/kernel.h>
48 #include <sys/errno.h>
49 #include <sys/syslog.h>
50 #include <sys/queue.h>
51 
52 #include <net/if.h>
53 #include <net/if_dl.h>
54 #include <net/if_types.h>
55 #include <net/if_atm.h>
56 #include <net/route.h>
57 
58 #include <netinet/in.h>
59 #include <netinet/if_ether.h>
60 #include <netinet/if_fddi.h>
61 #include <netinet6/in6_var.h>
62 #include <netinet6/ip6.h>
63 #include <netinet6/ip6_var.h>
64 #include <netinet6/nd6.h>
65 #include <netinet6/in6_prefix.h>
66 #include <netinet6/icmp6.h>
67 
68 #include "loop.h"
69 
70 #include <net/net_osdep.h>
71 
72 #define	ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */
73 #define	ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */
74 
75 #define	SIN6(s) ((struct sockaddr_in6 *)s)
76 #define	SDL(s) ((struct sockaddr_dl *)s)
77 
78 /* timer values */
79 int	nd6_prune	= 1;	/* walk list every 1 seconds */
80 int	nd6_delay	= 5;	/* delay first probe time 5 second */
81 int	nd6_umaxtries	= 3;	/* maximum unicast query */
82 int	nd6_mmaxtries	= 3;	/* maximum multicast query */
83 int	nd6_useloopback = 1;	/* use loopback interface for local traffic */
84 int	nd6_proxyall	= 0;	/* enable Proxy Neighbor Advertisement */
85 
86 /* for debugging? */
87 static int	nd6_inuse, nd6_allocated;
88 
89 struct	llinfo_nd6 llinfo_nd6 = {&llinfo_nd6, &llinfo_nd6};
90 struct	nd_ifinfo *nd_ifinfo = NULL;
91 struct	nd_drhead nd_defrouter = { 0 };
92 struct	nd_prhead nd_prefix = { 0 };
93 
94 int	nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL;
95 static struct	sockaddr_in6 all1_sa;
96 
97 static void	nd6_slowtimo __P((void *));
98 
99 void
100 nd6_init()
101 {
102 	static int nd6_init_done = 0;
103 	int i;
104 
105 	if (nd6_init_done) {
106 		log(LOG_NOTICE, "nd6_init called more than once(ignored)\n");
107 		return;
108 	}
109 
110 	all1_sa.sin6_family = AF_INET6;
111 	all1_sa.sin6_len = sizeof(struct sockaddr_in6);
112 	for (i = 0; i < sizeof(all1_sa.sin6_addr); i++)
113 		all1_sa.sin6_addr.s6_addr[i] = 0xff;
114 
115 	nd6_init_done = 1;
116 
117 	/* start timer */
118 	timeout(nd6_slowtimo, (caddr_t)0, ND6_SLOWTIMER_INTERVAL * hz);
119 }
120 
121 void
122 nd6_ifattach(ifp)
123 	struct ifnet *ifp;
124 {
125 	static size_t if_indexlim = 8;
126 
127 	/*
128 	 * We have some arrays that should be indexed by if_index.
129 	 * since if_index will grow dynamically, they should grow too.
130 	 */
131 	if (nd_ifinfo == NULL || if_index >= if_indexlim) {
132 		size_t n;
133 		caddr_t q;
134 
135 		while (if_index >= if_indexlim)
136 			if_indexlim <<= 1;
137 
138 		/* grow nd_ifinfo */
139 		n = if_indexlim * sizeof(struct nd_ifinfo);
140 		q = (caddr_t)malloc(n, M_IP6NDP, M_WAITOK);
141 		bzero(q, n);
142 		if (nd_ifinfo) {
143 			bcopy((caddr_t)nd_ifinfo, q, n/2);
144 			free((caddr_t)nd_ifinfo, M_IP6NDP);
145 		}
146 		nd_ifinfo = (struct nd_ifinfo *)q;
147 	}
148 
149 #define ND nd_ifinfo[ifp->if_index]
150 	ND.linkmtu = ifindex2ifnet[ifp->if_index]->if_mtu;
151 	ND.chlim = IPV6_DEFHLIM;
152 	ND.basereachable = REACHABLE_TIME;
153 	ND.reachable = ND_COMPUTE_RTIME(ND.basereachable);
154 	ND.retrans = RETRANS_TIMER;
155 	ND.receivedra = 0;
156 	nd6_setmtu(ifp);
157 #undef ND
158 }
159 
160 /*
161  * Reset ND level link MTU. This function is called when the physical MTU
162  * changes, which means we might have to adjust the ND level MTU.
163  */
164 void
165 nd6_setmtu(ifp)
166 	struct ifnet *ifp;
167 {
168 #define MIN(a,b) ((a) < (b) ? (a) : (b))
169 	struct nd_ifinfo *ndi = &nd_ifinfo[ifp->if_index];
170 	u_long oldmaxmtu = ndi->maxmtu;
171 	u_long oldlinkmtu = ndi->linkmtu;
172 
173 	switch(ifp->if_type) {
174 	 case IFT_ARCNET:	/* XXX MTU handling needs more work */
175 		 ndi->maxmtu = MIN(60480, ifp->if_mtu);
176 		 break;
177 	 case IFT_ETHER:
178 		 ndi->maxmtu = MIN(ETHERMTU, ifp->if_mtu);
179 		 break;
180 	 case IFT_FDDI:
181 		 ndi->maxmtu = MIN(FDDIIPMTU, ifp->if_mtu);
182 		 break;
183 	 case IFT_ATM:
184 		 ndi->maxmtu = MIN(ATMMTU, ifp->if_mtu);
185 		 break;
186 	 default:
187 		 ndi->maxmtu = ifp->if_mtu;
188 		 break;
189 	}
190 
191 	if (oldmaxmtu != ndi->maxmtu) {
192 		/*
193 		 * If the ND level MTU is not set yet, or if the maxmtu
194 		 * is reset to a smaller value than the ND level MTU,
195 		 * also reset the ND level MTU.
196 		 */
197 		if (ndi->linkmtu == 0 ||
198 		    ndi->maxmtu < ndi->linkmtu) {
199 			ndi->linkmtu = ndi->maxmtu;
200 			/* also adjust in6_maxmtu if necessary. */
201 			if (oldlinkmtu == 0) {
202 				/*
203 				 * XXX: the case analysis is grotty, but
204 				 * it is not efficient to call in6_setmaxmtu()
205 				 * here when we are during the initialization
206 				 * procedure.
207 				 */
208 				if (in6_maxmtu < ndi->linkmtu)
209 					in6_maxmtu = ndi->linkmtu;
210 			} else
211 				in6_setmaxmtu();
212 		}
213 	}
214 #undef MIN
215 }
216 
217 void
218 nd6_option_init(opt, icmp6len, ndopts)
219 	void *opt;
220 	int icmp6len;
221 	union nd_opts *ndopts;
222 {
223 	bzero(ndopts, sizeof(*ndopts));
224 	ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
225 	ndopts->nd_opts_last
226 		= (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len);
227 
228 	if (icmp6len == 0) {
229 		ndopts->nd_opts_done = 1;
230 		ndopts->nd_opts_search = NULL;
231 	}
232 }
233 
234 /*
235  * Take one ND option.
236  */
237 struct nd_opt_hdr *
238 nd6_option(ndopts)
239 	union nd_opts *ndopts;
240 {
241 	struct nd_opt_hdr *nd_opt;
242 	int olen;
243 
244 	if (!ndopts)
245 		panic("ndopts == NULL in nd6_option\n");
246 	if (!ndopts->nd_opts_last)
247 		panic("uninitialized ndopts in nd6_option\n");
248 	if (!ndopts->nd_opts_search)
249 		return NULL;
250 	if (ndopts->nd_opts_done)
251 		return NULL;
252 
253 	nd_opt = ndopts->nd_opts_search;
254 
255 	olen = nd_opt->nd_opt_len << 3;
256 	if (olen == 0) {
257 		/*
258 		 * Message validation requires that all included
259 		 * options have a length that is greater than zero.
260 		 */
261 		bzero(ndopts, sizeof(*ndopts));
262 		return NULL;
263 	}
264 
265 	ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen);
266 	if (!(ndopts->nd_opts_search < ndopts->nd_opts_last)) {
267 		ndopts->nd_opts_done = 1;
268 		ndopts->nd_opts_search = NULL;
269 	}
270 	return nd_opt;
271 }
272 
273 /*
274  * Parse multiple ND options.
275  * This function is much easier to use, for ND routines that do not need
276  * multiple options of the same type.
277  */
278 int
279 nd6_options(ndopts)
280 	union nd_opts *ndopts;
281 {
282 	struct nd_opt_hdr *nd_opt;
283 	int i = 0;
284 
285 	if (!ndopts)
286 		panic("ndopts == NULL in nd6_options\n");
287 	if (!ndopts->nd_opts_last)
288 		panic("uninitialized ndopts in nd6_options\n");
289 	if (!ndopts->nd_opts_search)
290 		return 0;
291 
292 	while (1) {
293 		nd_opt = nd6_option(ndopts);
294 		if (!nd_opt && !ndopts->nd_opts_last) {
295 			/*
296 			 * Message validation requires that all included
297 			 * options have a length that is greater than zero.
298 			 */
299 			bzero(ndopts, sizeof(*ndopts));
300 			return -1;
301 		}
302 
303 		if (!nd_opt)
304 			goto skip1;
305 
306 		switch (nd_opt->nd_opt_type) {
307 		case ND_OPT_SOURCE_LINKADDR:
308 		case ND_OPT_TARGET_LINKADDR:
309 		case ND_OPT_MTU:
310 		case ND_OPT_REDIRECTED_HEADER:
311 			if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
312 				printf("duplicated ND6 option found "
313 					"(type=%d)\n", nd_opt->nd_opt_type);
314 				/* XXX bark? */
315 			} else {
316 				ndopts->nd_opt_array[nd_opt->nd_opt_type]
317 					= nd_opt;
318 			}
319 			break;
320 		case ND_OPT_PREFIX_INFORMATION:
321 			if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
322 				ndopts->nd_opt_array[nd_opt->nd_opt_type]
323 					= nd_opt;
324 			}
325 			ndopts->nd_opts_pi_end =
326 				(struct nd_opt_prefix_info *)nd_opt;
327 			break;
328 		default:
329 			/*
330 			 * Unknown options must be silently ignored,
331 			 * to accomodate future extension to the protocol.
332 			 */
333 			log(LOG_INFO,
334 			    "nd6_options: unsupported option %d - "
335 			    "option ignored\n", nd_opt->nd_opt_type);
336 		}
337 
338 skip1:
339 		i++;
340 		if (i > 10) {
341 			printf("too many loop in nd opt\n");
342 			break;
343 		}
344 
345 		if (ndopts->nd_opts_done)
346 			break;
347 	}
348 
349 	return 0;
350 }
351 
352 /*
353  * ND6 timer routine to expire default route list and prefix list
354  */
355 void
356 nd6_timer(ignored_arg)
357 	void	*ignored_arg;
358 {
359 	int s;
360 	register struct llinfo_nd6 *ln;
361 	register struct nd_defrouter *dr;
362 	register struct nd_prefix *pr;
363 
364 	s = splnet();
365 	timeout(nd6_timer, (caddr_t)0, nd6_prune * hz);
366 
367 	ln = llinfo_nd6.ln_next;
368 	/* XXX BSD/OS separates this code -- itojun */
369 	while (ln && ln != &llinfo_nd6) {
370 		struct rtentry *rt;
371 		struct ifnet *ifp;
372 		struct sockaddr_in6 *dst;
373 		struct llinfo_nd6 *next = ln->ln_next;
374 
375 		if ((rt = ln->ln_rt) == NULL) {
376 			ln = next;
377 			continue;
378 		}
379 		if ((ifp = rt->rt_ifp) == NULL) {
380 			ln = next;
381 			continue;
382 		}
383 		dst = (struct sockaddr_in6 *)rt_key(rt);
384 
385 		if (ln->ln_expire > time_second) {
386 			ln = next;
387 			continue;
388 		}
389 
390 		/* sanity check */
391 		if (!rt)
392 			panic("rt=0 in nd6_timer(ln=%p)\n", ln);
393 		if (!dst)
394 			panic("dst=0 in nd6_timer(ln=%p)\n", ln);
395 
396 		switch (ln->ln_state) {
397 		case ND6_LLINFO_INCOMPLETE:
398 			if (ln->ln_asked < nd6_mmaxtries) {
399 				ln->ln_asked++;
400 				ln->ln_expire = time_second +
401 					nd_ifinfo[ifp->if_index].retrans / 1000;
402 				nd6_ns_output(ifp, NULL, &dst->sin6_addr,
403 					ln, 0);
404 			} else {
405 				struct mbuf *m = ln->ln_hold;
406 				if (m) {
407 					if (rt->rt_ifp) {
408 						/*
409 						 * Fake rcvif to make ICMP error
410 						 * more helpful in diagnosing
411 						 * for the receiver.
412 						 * XXX: should we consider
413 						 * older rcvif?
414 						 */
415 						m->m_pkthdr.rcvif = rt->rt_ifp;
416 					}
417 					icmp6_error(m, ICMP6_DST_UNREACH,
418 						    ICMP6_DST_UNREACH_ADDR, 0);
419 					ln->ln_hold = NULL;
420 				}
421 				nd6_free(rt);
422 			}
423 			break;
424 		case ND6_LLINFO_REACHABLE:
425 			if (ln->ln_expire) {
426 				ln->ln_state = ND6_LLINFO_STALE;
427 			}
428 			break;
429 		/*
430 		 * ND6_LLINFO_STALE state requires nothing for timer
431 		 * routine.
432 		 */
433 		case ND6_LLINFO_DELAY:
434 			ln->ln_asked = 1;
435 			ln->ln_state = ND6_LLINFO_PROBE;
436 			ln->ln_expire = time_second +
437 				nd_ifinfo[ifp->if_index].retrans / 1000;
438 			nd6_ns_output(ifp, &dst->sin6_addr, &dst->sin6_addr,
439 				ln, 0);
440 			break;
441 
442 		case ND6_LLINFO_PROBE:
443 			if (ln->ln_asked < nd6_umaxtries) {
444 				ln->ln_asked++;
445 				ln->ln_expire = time_second +
446 					nd_ifinfo[ifp->if_index].retrans / 1000;
447 				nd6_ns_output(ifp, &dst->sin6_addr,
448 					       &dst->sin6_addr, ln, 0);
449 			} else {
450 				nd6_free(rt);
451 			}
452 			break;
453 		case ND6_LLINFO_WAITDELETE:
454 			nd6_free(rt);
455 			break;
456 		}
457 		ln = next;
458 	}
459 
460 	/* expire */
461 	dr = LIST_FIRST(&nd_defrouter);
462 	while (dr) {
463 		if (dr->expire && dr->expire < time_second) {
464 			struct nd_defrouter *t;
465 			t = LIST_NEXT(dr, dr_entry);
466 			defrtrlist_del(dr);
467 			dr = t;
468 		} else
469 			dr = LIST_NEXT(dr, dr_entry);
470 	}
471 	pr = LIST_FIRST(&nd_prefix);
472 	while (pr) {
473 		struct in6_ifaddr *ia6;
474 		struct in6_addrlifetime *lt6;
475 
476 		if (IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr))
477 			ia6 = NULL;
478 		else
479 			ia6 = in6ifa_ifpwithaddr(pr->ndpr_ifp, &pr->ndpr_addr);
480 
481 		if (ia6) {
482 			/* check address lifetime */
483 			lt6 = &ia6->ia6_lifetime;
484 			if (lt6->ia6t_preferred && lt6->ia6t_preferred < time_second)
485 				ia6->ia6_flags |= IN6_IFF_DEPRECATED;
486 			if (lt6->ia6t_expire && lt6->ia6t_expire < time_second) {
487 				if (!IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr))
488 					in6_ifdel(pr->ndpr_ifp, &pr->ndpr_addr);
489 				/* xxx ND_OPT_PI_FLAG_ONLINK processing */
490 			}
491 		}
492 
493 		/*
494 		 * check prefix lifetime.
495 		 * since pltime is just for autoconf, pltime processing for
496 		 * prefix is not necessary.
497 		 *
498 		 * we offset expire time by NDPR_KEEP_EXPIRE, so that we
499 		 * can use the old prefix information to validate the
500 		 * next prefix information to come.  See prelist_update()
501 		 * for actual validation.
502 		 */
503 		if (pr->ndpr_expire
504 		 && pr->ndpr_expire + NDPR_KEEP_EXPIRED < time_second) {
505 			struct nd_prefix *t;
506 			t = LIST_NEXT(pr, ndpr_entry);
507 
508 			/*
509 			 * address expiration and prefix expiration are
510 			 * separate.  NEVER perform in6_ifdel here.
511 			 */
512 
513 			prelist_remove(pr);
514 			pr = t;
515 		} else
516 			pr = LIST_NEXT(pr, ndpr_entry);
517 	}
518 	splx(s);
519 }
520 
521 struct rtentry *
522 nd6_lookup(addr6, create, ifp)
523 	struct in6_addr *addr6;
524 	int create;
525 	struct ifnet *ifp;
526 {
527 	struct rtentry *rt;
528 	struct sockaddr_in6 sin6;
529 
530 	bzero(&sin6, sizeof(sin6));
531 	sin6.sin6_len = sizeof(struct sockaddr_in6);
532 	sin6.sin6_family = AF_INET6;
533 	sin6.sin6_addr = *addr6;
534 	rt = rtalloc1((struct sockaddr *)&sin6, create, 0UL);
535 	if (rt && (rt->rt_flags & RTF_LLINFO) == 0) {
536 		/*
537 		 * This is the case for the default route.
538 		 * If we want to create a neighbor cache for the address, we
539 		 * should free the route for the destination and allocate an
540 		 * interface route.
541 		 */
542 		if (create) {
543 			RTFREE(rt);
544 			rt = 0;
545 		}
546 	}
547 	if (!rt) {
548 		if (create && ifp) {
549 			/*
550 			 * If no route is available and create is set,
551 			 * we allocate a host route for the destination
552 			 * and treat it like an interface route.
553 			 * This hack is necessary for a neighbor which can't
554 			 * be covered by our own prefix.
555 			 */
556 			struct ifaddr *ifa =
557 				ifaof_ifpforaddr((struct sockaddr *)&sin6, ifp);
558 			if (ifa == NULL)
559 				return(NULL);
560 
561 			/*
562 			 * Create a new route. RTF_LLINFO is necessary
563 			 * to create a Neighbor Cache entry for the
564 			 * destination in nd6_rtrequest which will be
565 			 * called in rtequest via ifa->ifa_rtrequest.
566 			 */
567 			if (rtrequest(RTM_ADD, (struct sockaddr *)&sin6,
568 				      ifa->ifa_addr,
569 				      (struct sockaddr *)&all1_sa,
570 				      (ifa->ifa_flags |
571 				       RTF_HOST | RTF_LLINFO) & ~RTF_CLONING,
572 				      &rt))
573 				log(LOG_ERR,
574 				    "nd6_lookup: failed to add route for a "
575 				    "neighbor(%s)\n", ip6_sprintf(addr6));
576 			if (rt == NULL)
577 				return(NULL);
578 			if (rt->rt_llinfo) {
579 				struct llinfo_nd6 *ln =
580 					(struct llinfo_nd6 *)rt->rt_llinfo;
581 				ln->ln_state = ND6_LLINFO_NOSTATE;
582 			}
583 		} else
584 			return(NULL);
585 	}
586 	rt->rt_refcnt--;
587 	/*
588 	 * Validation for the entry.
589 	 * XXX: we can't use rt->rt_ifp to check for the interface, since
590 	 *      it might be the loopback interface if the entry is for our
591 	 *      own address on a non-loopback interface. Instead, we should
592 	 *      use rt->rt_ifa->ifa_ifp, which would specify the REAL interface.
593 	 */
594 	if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 ||
595 	    rt->rt_gateway->sa_family != AF_LINK ||
596 	    (ifp && rt->rt_ifa->ifa_ifp != ifp)) {
597 		if (create) {
598 			log(LOG_DEBUG, "nd6_lookup: failed to lookup %s (if = %s)\n",
599 			    ip6_sprintf(addr6), ifp ? if_name(ifp) : "unspec");
600 			/* xxx more logs... kazu */
601 		}
602 		return(0);
603 	}
604 	return(rt);
605 }
606 
607 /*
608  * Detect if a given IPv6 address identifies a neighbor on a given link.
609  * XXX: should take care of the destination of a p2p link?
610  */
611 int
612 nd6_is_addr_neighbor(addr, ifp)
613 	struct in6_addr *addr;
614 	struct ifnet *ifp;
615 {
616 	register struct ifaddr *ifa;
617 	int i;
618 
619 #define IFADDR6(a) ((((struct in6_ifaddr *)(a))->ia_addr).sin6_addr)
620 #define IFMASK6(a) ((((struct in6_ifaddr *)(a))->ia_prefixmask).sin6_addr)
621 
622 	/* A link-local address is always a neighbor. */
623 	if (IN6_IS_ADDR_LINKLOCAL(addr))
624 		return(1);
625 
626 	/*
627 	 * If the address matches one of our addresses,
628 	 * it should be a neighbor.
629 	 */
630 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
631 	{
632 		if (ifa->ifa_addr->sa_family != AF_INET6)
633 			next: continue;
634 
635 		for (i = 0; i < 4; i++) {
636 			if ((IFADDR6(ifa).s6_addr32[i] ^ addr->s6_addr32[i]) &
637 			    IFMASK6(ifa).s6_addr32[i])
638 				goto next;
639 		}
640 		return(1);
641 	}
642 
643 	/*
644 	 * Even if the address matches none of our addresses, it might be
645 	 * in the neighbor cache.
646 	 */
647 	if (nd6_lookup(addr, 0, ifp))
648 		return(1);
649 
650 	return(0);
651 #undef IFADDR6
652 #undef IFMASK6
653 }
654 
655 /*
656  * Free an nd6 llinfo entry.
657  */
658 void
659 nd6_free(rt)
660 	struct rtentry *rt;
661 {
662 	struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo;
663 	struct sockaddr_dl *sdl;
664 
665 	if (ln->ln_router) {
666 		/* remove from default router list */
667 		struct nd_defrouter *dr;
668 		struct in6_addr *in6;
669 		int s;
670 		in6 = &((struct sockaddr_in6 *)rt_key(rt))->sin6_addr;
671 
672 		s = splnet();
673 		dr = defrouter_lookup(&((struct sockaddr_in6 *)rt_key(rt))->
674 				      sin6_addr,
675 				      rt->rt_ifp);
676 		if (dr)
677 			defrtrlist_del(dr);
678 		else if (!ip6_forwarding && ip6_accept_rtadv) {
679 			/*
680 			 * rt6_flush must be called in any case.
681 			 * see the comment in nd6_na_input().
682 			 */
683 			rt6_flush(in6, rt->rt_ifp);
684 		}
685 		splx(s);
686 	}
687 
688 	if (rt->rt_refcnt > 0 && (sdl = SDL(rt->rt_gateway)) &&
689 	   sdl->sdl_family == AF_LINK) {
690 		sdl->sdl_alen = 0;
691 		ln->ln_state = ND6_LLINFO_WAITDELETE;
692 		ln->ln_asked = 0;
693 		rt->rt_flags &= ~RTF_REJECT;
694 		return;
695 	}
696 	rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, rt_mask(rt),
697 		  0, (struct rtentry **)0);
698 }
699 
700 /*
701  * Upper-layer reachability hint for Neighbor Unreachability Detection.
702  *
703  * XXX cost-effective metods?
704  */
705 void
706 nd6_nud_hint(rt, dst6)
707 	struct rtentry *rt;
708 	struct in6_addr *dst6;
709 {
710 	struct llinfo_nd6 *ln;
711 
712 	/*
713 	 * If the caller specified "rt", use that.  Otherwise, resolve the
714 	 * routing table by supplied "dst6".
715 	 */
716 	if (!rt) {
717 		if (!dst6)
718 			return;
719 		if (!(rt = nd6_lookup(dst6, 0, NULL)))
720 			return;
721 	}
722 
723 	if ((rt->rt_flags & RTF_GATEWAY)
724 	 || (rt->rt_flags & RTF_LLINFO) == 0
725 	 || !rt->rt_llinfo
726 	 || !rt->rt_gateway
727 	 || rt->rt_gateway->sa_family != AF_LINK) {
728 		/* This is not a host route. */
729 		return;
730 	}
731 
732 	ln = (struct llinfo_nd6 *)rt->rt_llinfo;
733 	if (ln->ln_state == ND6_LLINFO_INCOMPLETE)
734 		return;
735 
736 	ln->ln_state = ND6_LLINFO_REACHABLE;
737 	if (ln->ln_expire)
738 		ln->ln_expire = time_second +
739 			nd_ifinfo[rt->rt_ifp->if_index].reachable;
740 }
741 
742 void
743 nd6_rtrequest(req, rt, sa)
744 	int	req;
745 	struct rtentry *rt;
746 	struct sockaddr *sa; /* xxx unused */
747 {
748 	struct sockaddr *gate = rt->rt_gateway;
749 	struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo;
750 	static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
751 	struct ifnet *ifp = rt->rt_ifp;
752 	struct ifaddr *ifa;
753 
754 	if (rt->rt_flags & RTF_GATEWAY)
755 		return;
756 
757 	switch (req) {
758 	case RTM_ADD:
759 		/*
760 		 * There is no backward compatibility :)
761 		 *
762 		 * if ((rt->rt_flags & RTF_HOST) == 0 &&
763 		 *     SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff)
764 		 *	   rt->rt_flags |= RTF_CLONING;
765 		 */
766 		if (rt->rt_flags & RTF_CLONING || rt->rt_flags & RTF_LLINFO) {
767 			/*
768 			 * Case 1: This route should come from
769 			 * a route to interface. RTF_LLINFO flag is set
770 			 * for a host route whose destination should be
771 			 * treated as on-link.
772 			 */
773 			rt_setgate(rt, rt_key(rt),
774 				   (struct sockaddr *)&null_sdl);
775 			gate = rt->rt_gateway;
776 			SDL(gate)->sdl_type = ifp->if_type;
777 			SDL(gate)->sdl_index = ifp->if_index;
778 			if (ln)
779 				ln->ln_expire = time_second;
780 			if (ln && ln->ln_expire == 0) {
781 				/* cludge for desktops */
782 				ln->ln_expire = 1;
783 			}
784 			if (rt->rt_flags & RTF_CLONING)
785 				break;
786 		}
787 		/* Announce a new entry if requested. */
788 		if (rt->rt_flags & RTF_ANNOUNCE)
789 			nd6_na_output(ifp,
790 				      &SIN6(rt_key(rt))->sin6_addr,
791 				      &SIN6(rt_key(rt))->sin6_addr,
792 				      ip6_forwarding ? ND_NA_FLAG_ROUTER : 0,
793 				      1);
794 		/* FALLTHROUGH */
795 	case RTM_RESOLVE:
796 		if (gate->sa_family != AF_LINK ||
797 		   gate->sa_len < sizeof(null_sdl)) {
798 			log(LOG_DEBUG, "nd6_rtrequest: bad gateway value\n");
799 			break;
800 		}
801 		SDL(gate)->sdl_type = ifp->if_type;
802 		SDL(gate)->sdl_index = ifp->if_index;
803 		if (ln != 0)
804 			break;	/* This happens on a route change */
805 		/*
806 		 * Case 2: This route may come from cloning, or a manual route
807 		 * add with a LL address.
808 		 */
809 		R_Malloc(ln, struct llinfo_nd6 *, sizeof(*ln));
810 		rt->rt_llinfo = (caddr_t)ln;
811 		if (!ln) {
812 			log(LOG_DEBUG, "nd6_rtrequest: malloc failed\n");
813 			break;
814 		}
815 		nd6_inuse++;
816 		nd6_allocated++;
817 		Bzero(ln, sizeof(*ln));
818 		ln->ln_rt = rt;
819 		/* this is required for "ndp" command. - shin */
820 		if (req == RTM_ADD) {
821 		        /*
822 			 * gate should have some valid AF_LINK entry,
823 			 * and ln->ln_expire should have some lifetime
824 			 * which is specified by ndp command.
825 			 */
826 			ln->ln_state = ND6_LLINFO_REACHABLE;
827 		} else {
828 		        /*
829 			 * When req == RTM_RESOLVE, rt is created and
830 			 * initialized in rtrequest(), so rt_expire is 0.
831 			 */
832 			ln->ln_state = ND6_LLINFO_INCOMPLETE;
833 			ln->ln_expire = time_second;
834 		}
835 		rt->rt_flags |= RTF_LLINFO;
836 		ln->ln_next = llinfo_nd6.ln_next;
837 		llinfo_nd6.ln_next = ln;
838 		ln->ln_prev = &llinfo_nd6;
839 		ln->ln_next->ln_prev = ln;
840 
841 		/*
842 		 * check if rt_key(rt) is one of my address assigned
843 		 * to the interface.
844 		 */
845 		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(rt->rt_ifp,
846 					  &SIN6(rt_key(rt))->sin6_addr);
847 		if (ifa) {
848 			caddr_t macp = nd6_ifptomac(ifp);
849 			ln->ln_expire = 0;
850 			ln->ln_state = ND6_LLINFO_REACHABLE;
851 			if (macp) {
852 				Bcopy(macp, LLADDR(SDL(gate)), ifp->if_addrlen);
853 				SDL(gate)->sdl_alen = ifp->if_addrlen;
854 			}
855 			if (nd6_useloopback) {
856 				rt->rt_ifp = &loif[0];	/*XXX*/
857 				/*
858 				 * Make sure rt_ifa be equal to the ifaddr
859 				 * corresponding to the address.
860 				 * We need this because when we refer
861 				 * rt_ifa->ia6_flags in ip6_input, we assume
862 				 * that the rt_ifa points to the address instead
863 				 * of the loopback address.
864 				 */
865 				if (ifa != rt->rt_ifa) {
866 					rt->rt_ifa->ifa_refcnt--;
867 					ifa->ifa_refcnt++;
868 					rt->rt_ifa = ifa;
869 				}
870 			}
871 		}
872 		break;
873 
874 	case RTM_DELETE:
875 		if (!ln)
876 			break;
877 		nd6_inuse--;
878 		ln->ln_next->ln_prev = ln->ln_prev;
879 		ln->ln_prev->ln_next = ln->ln_next;
880 		ln->ln_prev = NULL;
881 		rt->rt_llinfo = 0;
882 		rt->rt_flags &= ~RTF_LLINFO;
883 		if (ln->ln_hold)
884 			m_freem(ln->ln_hold);
885 		Free((caddr_t)ln);
886 	}
887 }
888 
889 void
890 nd6_p2p_rtrequest(req, rt, sa)
891 	int	req;
892 	struct rtentry *rt;
893 	struct sockaddr *sa; /* xxx unused */
894 {
895 	struct sockaddr *gate = rt->rt_gateway;
896 	static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
897 	struct ifnet *ifp = rt->rt_ifp;
898 	struct ifaddr *ifa;
899 
900 	if (rt->rt_flags & RTF_GATEWAY)
901 		return;
902 
903 	switch (req) {
904 	case RTM_ADD:
905 		/*
906 		 * There is no backward compatibility :)
907 		 *
908 		 * if ((rt->rt_flags & RTF_HOST) == 0 &&
909 		 *     SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff)
910 		 *	   rt->rt_flags |= RTF_CLONING;
911 		 */
912 		if (rt->rt_flags & RTF_CLONING) {
913 			/*
914 			 * Case 1: This route should come from
915 			 * a route to interface.
916 			 */
917 			rt_setgate(rt, rt_key(rt),
918 				   (struct sockaddr *)&null_sdl);
919 			gate = rt->rt_gateway;
920 			SDL(gate)->sdl_type = ifp->if_type;
921 			SDL(gate)->sdl_index = ifp->if_index;
922 			break;
923 		}
924 		/* Announce a new entry if requested. */
925 		if (rt->rt_flags & RTF_ANNOUNCE)
926 			nd6_na_output(ifp,
927 				      &SIN6(rt_key(rt))->sin6_addr,
928 				      &SIN6(rt_key(rt))->sin6_addr,
929 				      ip6_forwarding ? ND_NA_FLAG_ROUTER : 0,
930 				      1);
931 		/* FALLTHROUGH */
932 	case RTM_RESOLVE:
933 		/*
934 		 * check if rt_key(rt) is one of my address assigned
935 		 * to the interface.
936 		 */
937  		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(rt->rt_ifp,
938 					  &SIN6(rt_key(rt))->sin6_addr);
939 		if (ifa) {
940 			if (nd6_useloopback) {
941 				rt->rt_ifp = &loif[0];	/*XXX*/
942 			}
943 		}
944 		break;
945 	}
946 }
947 
948 int
949 nd6_ioctl(cmd, data, ifp)
950 	u_long cmd;
951 	caddr_t	data;
952 	struct ifnet *ifp;
953 {
954 	struct in6_drlist *drl = (struct in6_drlist *)data;
955 	struct in6_prlist *prl = (struct in6_prlist *)data;
956 	struct in6_ndireq *ndi = (struct in6_ndireq *)data;
957 	struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data;
958 	struct nd_defrouter *dr, any;
959 	struct nd_prefix *pr;
960 	struct rtentry *rt;
961 	int i = 0, error = 0;
962 	int s;
963 
964 	switch (cmd) {
965 	case SIOCGDRLST_IN6:
966 		bzero(drl, sizeof(*drl));
967 		s = splnet();
968 		dr = LIST_FIRST(&nd_defrouter);
969 		while (dr && i < DRLSTSIZ) {
970 			drl->defrouter[i].rtaddr = dr->rtaddr;
971 			if (IN6_IS_ADDR_LINKLOCAL(&drl->defrouter[i].rtaddr)) {
972 				/* XXX: need to this hack for KAME stack */
973 				drl->defrouter[i].rtaddr.s6_addr16[1] = 0;
974 			} else
975 				log(LOG_ERR,
976 				    "default router list contains a "
977 				    "non-linklocal address(%s)\n",
978 				    ip6_sprintf(&drl->defrouter[i].rtaddr));
979 
980 			drl->defrouter[i].flags = dr->flags;
981 			drl->defrouter[i].rtlifetime = dr->rtlifetime;
982 			drl->defrouter[i].expire = dr->expire;
983 			drl->defrouter[i].if_index = dr->ifp->if_index;
984 			i++;
985 			dr = LIST_NEXT(dr, dr_entry);
986 		}
987 		splx(s);
988 		break;
989 	case SIOCGPRLST_IN6:
990 		bzero(prl, sizeof(*prl));
991 		s = splnet();
992 		pr = LIST_FIRST(&nd_prefix);
993 		while (pr && i < PRLSTSIZ) {
994 			struct nd_pfxrouter *pfr;
995 			int j;
996 
997 			prl->prefix[i].prefix = pr->ndpr_prefix.sin6_addr;
998 			prl->prefix[i].raflags = pr->ndpr_raf;
999 			prl->prefix[i].prefixlen = pr->ndpr_plen;
1000 			prl->prefix[i].vltime = pr->ndpr_vltime;
1001 			prl->prefix[i].pltime = pr->ndpr_pltime;
1002 			prl->prefix[i].if_index = pr->ndpr_ifp->if_index;
1003 			prl->prefix[i].expire = pr->ndpr_expire;
1004 
1005 			pfr = LIST_FIRST(&pr->ndpr_advrtrs);
1006 			j = 0;
1007 			while(pfr) {
1008 				if (j < DRLSTSIZ) {
1009 #define RTRADDR prl->prefix[i].advrtr[j]
1010 					RTRADDR = pfr->router->rtaddr;
1011 					if (IN6_IS_ADDR_LINKLOCAL(&RTRADDR)) {
1012 						/* XXX: hack for KAME */
1013 						RTRADDR.s6_addr16[1] = 0;
1014 					} else
1015 						log(LOG_ERR,
1016 						    "a router(%s) advertises "
1017 						    "a prefix with "
1018 						    "non-link local address\n",
1019 						    ip6_sprintf(&RTRADDR));
1020 #undef RTRADDR
1021 				}
1022 				j++;
1023 				pfr = LIST_NEXT(pfr, pfr_entry);
1024 			}
1025 			prl->prefix[i].advrtrs = j;
1026 
1027 			i++;
1028 			pr = LIST_NEXT(pr, ndpr_entry);
1029 		}
1030 		splx(s);
1031 	      {
1032 		struct rr_prefix *rpp;
1033 
1034 		for (rpp = LIST_FIRST(&rr_prefix); rpp;
1035 		     rpp = LIST_NEXT(rpp, rp_entry)) {
1036 			if (i >= PRLSTSIZ)
1037 				break;
1038 			prl->prefix[i].prefix = rpp->rp_prefix.sin6_addr;
1039 			prl->prefix[i].raflags = rpp->rp_raf;
1040 			prl->prefix[i].prefixlen = rpp->rp_plen;
1041 			prl->prefix[i].vltime = rpp->rp_vltime;
1042 			prl->prefix[i].pltime = rpp->rp_pltime;
1043 			prl->prefix[i].if_index = rpp->rp_ifp->if_index;
1044 			prl->prefix[i].expire = rpp->rp_expire;
1045 			prl->prefix[i].advrtrs = 0;
1046 			i++;
1047 		}
1048 	      }
1049 
1050 		break;
1051 	case SIOCGIFINFO_IN6:
1052 		ndi->ndi = nd_ifinfo[ifp->if_index];
1053 		break;
1054 	case SIOCSNDFLUSH_IN6:
1055 		/* flush default router list */
1056 		/*
1057 		 * xxx sumikawa: should not delete route if default
1058 		 * route equals to the top of default router list
1059 		 */
1060 		bzero(&any, sizeof(any));
1061 		defrouter_delreq(&any, 0);
1062 		/* xxx sumikawa: flush prefix list */
1063 		break;
1064 	case SIOCSPFXFLUSH_IN6:
1065 	    {
1066 		/* flush all the prefix advertised by routers */
1067 		struct nd_prefix *pr, *next;
1068 
1069 		s = splnet();
1070 		for (pr = LIST_FIRST(&nd_prefix); pr; pr = next) {
1071 			next = LIST_NEXT(pr, ndpr_entry);
1072 			if (!IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr))
1073 				in6_ifdel(pr->ndpr_ifp, &pr->ndpr_addr);
1074 			prelist_remove(pr);
1075 		}
1076 		splx(s);
1077 		break;
1078 	    }
1079 	case SIOCSRTRFLUSH_IN6:
1080 	    {
1081 		/* flush all the default routers */
1082 		struct nd_defrouter *dr, *next;
1083 
1084 		s = splnet();
1085 		if ((dr = LIST_FIRST(&nd_defrouter)) != NULL) {
1086 			/*
1087 			 * The first entry of the list may be stored in
1088 			 * the routing table, so we'll delete it later.
1089 			 */
1090 			for (dr = LIST_NEXT(dr, dr_entry); dr; dr = next) {
1091 				next = LIST_NEXT(dr, dr_entry);
1092 				defrtrlist_del(dr);
1093 			}
1094 			defrtrlist_del(LIST_FIRST(&nd_defrouter));
1095 		}
1096 		splx(s);
1097 		break;
1098 	    }
1099 	case SIOCGNBRINFO_IN6:
1100 	    {
1101 		struct llinfo_nd6 *ln;
1102 		struct in6_addr nb_addr = nbi->addr; /* make local for safety */
1103 
1104 		/*
1105 		 * XXX: KAME specific hack for scoped addresses
1106 		 *      XXXX: for other scopes than link-local?
1107 		 */
1108 		if (IN6_IS_ADDR_LINKLOCAL(&nbi->addr) ||
1109 		    IN6_IS_ADDR_MC_LINKLOCAL(&nbi->addr)) {
1110 			u_int16_t *idp = (u_int16_t *)&nb_addr.s6_addr[2];
1111 
1112 			if (*idp == 0)
1113 				*idp = htons(ifp->if_index);
1114 		}
1115 
1116 		s = splnet();
1117 		if ((rt = nd6_lookup(&nb_addr, 0, ifp)) == NULL) {
1118 			error = EINVAL;
1119 			break;
1120 		}
1121 		ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1122 		nbi->state = ln->ln_state;
1123 		nbi->asked = ln->ln_asked;
1124 		nbi->isrouter = ln->ln_router;
1125 		nbi->expire = ln->ln_expire;
1126 		splx(s);
1127 
1128 		break;
1129 	    }
1130 	}
1131 	return(error);
1132 }
1133 
1134 /*
1135  * Create neighbor cache entry and cache link-layer address,
1136  * on reception of inbound ND6 packets. (RS/RA/NS/redirect)
1137  */
1138 struct rtentry *
1139 nd6_cache_lladdr(ifp, from, lladdr, lladdrlen, type, code)
1140 	struct ifnet *ifp;
1141 	struct in6_addr *from;
1142 	char *lladdr;
1143 	int lladdrlen;
1144 	int type;	/* ICMP6 type */
1145 	int code;	/* type dependent information */
1146 {
1147 	struct rtentry *rt = NULL;
1148 	struct llinfo_nd6 *ln = NULL;
1149 	int is_newentry;
1150 	struct sockaddr_dl *sdl = NULL;
1151 	int do_update;
1152 	int olladdr;
1153 	int llchange;
1154 	int newstate = 0;
1155 
1156 	if (!ifp)
1157 		panic("ifp == NULL in nd6_cache_lladdr");
1158 	if (!from)
1159 		panic("from == NULL in nd6_cache_lladdr");
1160 
1161 	/* nothing must be updated for unspecified address */
1162 	if (IN6_IS_ADDR_UNSPECIFIED(from))
1163 		return NULL;
1164 
1165 	/*
1166 	 * Validation about ifp->if_addrlen and lladdrlen must be done in
1167 	 * the caller.
1168 	 *
1169 	 * XXX If the link does not have link-layer adderss, what should
1170 	 * we do? (ifp->if_addrlen == 0)
1171 	 * Spec says nothing in sections for RA, RS and NA.  There's small
1172 	 * description on it in NS section (RFC 2461 7.2.3).
1173 	 */
1174 
1175 	rt = nd6_lookup(from, 0, ifp);
1176 	if (!rt) {
1177 		rt = nd6_lookup(from, 1, ifp);
1178 		is_newentry = 1;
1179 	} else
1180 		is_newentry = 0;
1181 
1182 	if (!rt)
1183 		return NULL;
1184 	if ((rt->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) != RTF_LLINFO) {
1185 fail:
1186 		nd6_free(rt);
1187 		return NULL;
1188 	}
1189 	ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1190 	if (!ln)
1191 		goto fail;
1192 	if (!rt->rt_gateway)
1193 		goto fail;
1194 	if (rt->rt_gateway->sa_family != AF_LINK)
1195 		goto fail;
1196 	sdl = SDL(rt->rt_gateway);
1197 
1198 	olladdr = (sdl->sdl_alen) ? 1 : 0;
1199 	if (olladdr && lladdr) {
1200 		if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen))
1201 			llchange = 1;
1202 		else
1203 			llchange = 0;
1204 	} else
1205 		llchange = 0;
1206 
1207 	/*
1208 	 * newentry olladdr  lladdr  llchange	(*=record)
1209 	 *	0	n	n	--	(1)
1210 	 *	0	y	n	--	(2)
1211 	 *	0	n	y	--	(3) * STALE
1212 	 *	0	y	y	n	(4) *
1213 	 *	0	y	y	y	(5) * STALE
1214 	 *	1	--	n	--	(6)   NOSTATE(= PASSIVE)
1215 	 *	1	--	y	--	(7) * STALE
1216 	 */
1217 
1218 	if (lladdr) {		/*(3-5) and (7)*/
1219 		/*
1220 		 * Record source link-layer address
1221 		 * XXX is it dependent to ifp->if_type?
1222 		 */
1223 		sdl->sdl_alen = ifp->if_addrlen;
1224 		bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen);
1225 	}
1226 
1227 	if (!is_newentry) {
1228 		if ((!olladdr && lladdr)		/*(3)*/
1229 		 || (olladdr && lladdr && llchange)) {	/*(5)*/
1230 			do_update = 1;
1231 			newstate = ND6_LLINFO_STALE;
1232 		} else					/*(1-2,4)*/
1233 			do_update = 0;
1234 	} else {
1235 		do_update = 1;
1236 		if (!lladdr)				/*(6)*/
1237 			newstate = ND6_LLINFO_NOSTATE;
1238 		else					/*(7)*/
1239 			newstate = ND6_LLINFO_STALE;
1240 	}
1241 
1242 	if (do_update) {
1243 		/*
1244 		 * Update the state of the neighbor cache.
1245 		 */
1246 		ln->ln_state = newstate;
1247 
1248 		if (ln->ln_state == ND6_LLINFO_STALE) {
1249 			rt->rt_flags &= ~RTF_REJECT;
1250 			if (ln->ln_hold) {
1251 				nd6_output(ifp, ln->ln_hold,
1252 					   (struct sockaddr_in6 *)rt_key(rt),
1253 					   rt);
1254 				ln->ln_hold = 0;
1255 			}
1256 		} else if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
1257 			/* probe right away */
1258 			ln->ln_expire = time_second;
1259 		}
1260 	}
1261 
1262 	/*
1263 	 * ICMP6 type dependent behavior.
1264 	 *
1265 	 * NS: clear IsRouter if new entry
1266 	 * RS: clear IsRouter
1267 	 * RA: set IsRouter if there's lladdr
1268 	 * redir: clear IsRouter if new entry
1269 	 *
1270 	 * RA case, (1):
1271 	 * The spec says that we must set IsRouter in the following cases:
1272 	 * - If lladdr exist, set IsRouter.  This means (1-5).
1273 	 * - If it is old entry (!newentry), set IsRouter.  This means (7).
1274 	 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
1275 	 * A quetion arises for (1) case.  (1) case has no lladdr in the
1276 	 * neighbor cache, this is similar to (6).
1277 	 * This case is rare but we figured that we MUST NOT set IsRouter.
1278 	 *
1279 	 * newentry olladdr  lladdr  llchange	    NS  RS  RA	redir
1280 	 *							D R
1281 	 *	0	n	n	--	(1)	c   ?     s
1282 	 *	0	y	n	--	(2)	c   s     s
1283 	 *	0	n	y	--	(3)	c   s     s
1284 	 *	0	y	y	n	(4)	c   s     s
1285 	 *	0	y	y	y	(5)	c   s     s
1286 	 *	1	--	n	--	(6) c	c 	c s
1287 	 *	1	--	y	--	(7) c	c   s	c s
1288 	 *
1289 	 *					(c=clear s=set)
1290 	 */
1291 	switch (type & 0xff) {
1292 	case ND_NEIGHBOR_SOLICIT:
1293 		/*
1294 		 * New entry must have is_router flag cleared.
1295 		 */
1296 		if (is_newentry)	/*(6-7)*/
1297 			ln->ln_router = 0;
1298 		break;
1299 	case ND_REDIRECT:
1300 		/*
1301 		 * If the icmp is a redirect to a better router, always set the
1302 		 * is_router flag. Otherwise, if the entry is newly created,
1303 		 * clear the flag. [RFC 2461, sec 8.3]
1304 		 *
1305 		 */
1306 		if (code == ND_REDIRECT_ROUTER)
1307 			ln->ln_router = 1;
1308 		else if (is_newentry) /*(6-7)*/
1309 			ln->ln_router = 0;
1310 		break;
1311 	case ND_ROUTER_SOLICIT:
1312 		/*
1313 		 * is_router flag must always be cleared.
1314 		 */
1315 		ln->ln_router = 0;
1316 		break;
1317 	case ND_ROUTER_ADVERT:
1318 		/*
1319 		 * Mark an entry with lladdr as a router.
1320 		 */
1321 		if ((!is_newentry && (olladdr || lladdr))	/*(2-5)*/
1322 		 || (is_newentry && lladdr)) {			/*(7)*/
1323 			ln->ln_router = 1;
1324 		}
1325 		break;
1326 	}
1327 
1328 	return rt;
1329 }
1330 
1331 static void
1332 nd6_slowtimo(ignored_arg)
1333     void *ignored_arg;
1334 {
1335 	int s = splnet();
1336 	register int i;
1337 	register struct nd_ifinfo *nd6if;
1338 
1339 	timeout(nd6_slowtimo, (caddr_t)0, ND6_SLOWTIMER_INTERVAL * hz);
1340 	for (i = 1; i < if_index + 1; i++) {
1341 		nd6if = &nd_ifinfo[i];
1342 		if (nd6if->basereachable && /* already initialized */
1343 		    (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
1344 			/*
1345 			 * Since reachable time rarely changes by router
1346 			 * advertisements, we SHOULD insure that a new random
1347 			 * value gets recomputed at least once every few hours.
1348 			 * (RFC 2461, 6.3.4)
1349 			 */
1350 			nd6if->recalctm = nd6_recalc_reachtm_interval;
1351 			nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable);
1352 		}
1353 	}
1354 	splx(s);
1355 }
1356 
1357 #define senderr(e) { error = (e); goto bad;}
1358 int
1359 nd6_output(ifp, m0, dst, rt0)
1360 	register struct ifnet *ifp;
1361 	struct mbuf *m0;
1362 	struct sockaddr_in6 *dst;
1363 	struct rtentry *rt0;
1364 {
1365 	register struct mbuf *m = m0;
1366 	register struct rtentry *rt = rt0;
1367 	struct llinfo_nd6 *ln = NULL;
1368 	int error = 0;
1369 
1370 	if (IN6_IS_ADDR_MULTICAST(&dst->sin6_addr))
1371 		goto sendpkt;
1372 
1373 	/*
1374 	 * XXX: we currently do not make neighbor cache on any interface
1375 	 * other than ARCnet, Ethernet and FDDI.
1376 	 */
1377 	switch (ifp->if_type) {
1378 	case IFT_ARCNET:
1379 	case IFT_ETHER:
1380 	case IFT_FDDI:
1381 		break;
1382 	default:
1383 		goto sendpkt;
1384 	}
1385 
1386 	/*
1387 	 * next hop determination. This routine is derived from ether_outpout.
1388 	 */
1389 	if (rt) {
1390 		if ((rt->rt_flags & RTF_UP) == 0) {
1391 			if ((rt0 = rt = rtalloc1((struct sockaddr *)dst, 1, 0UL)) !=
1392 				NULL)
1393 			{
1394 				rt->rt_refcnt--;
1395 				if (rt->rt_ifp != ifp)
1396 					return nd6_output(ifp, m0, dst, rt); /* XXX: loop care? */
1397 			} else
1398 				senderr(EHOSTUNREACH);
1399 		}
1400 		if (rt->rt_flags & RTF_GATEWAY) {
1401 			if (rt->rt_gwroute == 0)
1402 				goto lookup;
1403 			if (((rt = rt->rt_gwroute)->rt_flags & RTF_UP) == 0) {
1404 				rtfree(rt); rt = rt0;
1405 			lookup: rt->rt_gwroute = rtalloc1(rt->rt_gateway, 1, 0UL);
1406 				if ((rt = rt->rt_gwroute) == 0)
1407 					senderr(EHOSTUNREACH);
1408 			}
1409 		}
1410 		if (rt->rt_flags & RTF_REJECT)
1411 			senderr(rt == rt0 ? EHOSTDOWN : EHOSTUNREACH);
1412 	}
1413 
1414 	/*
1415 	 * Address resolution or Neighbor Unreachability Detection
1416 	 * for the next hop.
1417 	 * At this point, the destination of the packet must be a unicast
1418 	 * or an anycast address(i.e. not a multicast).
1419 	 */
1420 
1421 	/* Look up the neighbor cache for the nexthop */
1422 	if (rt && (rt->rt_flags & RTF_LLINFO) != 0)
1423 		ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1424 	else {
1425 		if ((rt = nd6_lookup(&dst->sin6_addr, 1, ifp)) != NULL)
1426 			ln = (struct llinfo_nd6 *)rt->rt_llinfo;
1427 	}
1428 	if (!ln || !rt) {
1429 		log(LOG_DEBUG, "nd6_output: can't allocate llinfo for %s "
1430 		    "(ln=%p, rt=%p)\n",
1431 		    ip6_sprintf(&dst->sin6_addr), ln, rt);
1432 		senderr(EIO);	/* XXX: good error? */
1433 	}
1434 
1435 
1436 	/*
1437 	 * The first time we send a packet to a neighbor whose entry is
1438 	 * STALE, we have to change the state to DELAY and a sets a timer to
1439 	 * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do
1440 	 * neighbor unreachability detection on expiration.
1441 	 * (RFC 2461 7.3.3)
1442 	 */
1443 	if (ln->ln_state == ND6_LLINFO_STALE) {
1444 		ln->ln_asked = 0;
1445 		ln->ln_state = ND6_LLINFO_DELAY;
1446 		ln->ln_expire = time_second + nd6_delay;
1447 	}
1448 
1449 	/*
1450 	 * If the neighbor cache entry has a state other than INCOMPLETE
1451 	 * (i.e. its link-layer address is already reloved), just
1452 	 * send the packet.
1453 	 */
1454 	if (ln->ln_state > ND6_LLINFO_INCOMPLETE)
1455 		goto sendpkt;
1456 
1457 	/*
1458 	 * There is a neighbor cache entry, but no ethernet address
1459 	 * response yet. Replace the held mbuf (if any) with this
1460 	 * latest one.
1461 	 *
1462 	 * XXX Does the code conform to rate-limiting rule?
1463 	 * (RFC 2461 7.2.2)
1464 	 */
1465 	if (ln->ln_state == ND6_LLINFO_WAITDELETE ||
1466 	    ln->ln_state == ND6_LLINFO_NOSTATE)
1467 		ln->ln_state = ND6_LLINFO_INCOMPLETE;
1468 	if (ln->ln_hold)
1469 		m_freem(ln->ln_hold);
1470 	ln->ln_hold = m;
1471 	if (ln->ln_expire) {
1472 		rt->rt_flags &= ~RTF_REJECT;
1473 		if (ln->ln_asked < nd6_mmaxtries &&
1474 		    ln->ln_expire < time_second) {
1475 			ln->ln_asked++;
1476 			ln->ln_expire = time_second +
1477 				nd_ifinfo[ifp->if_index].retrans / 1000;
1478 			nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0);
1479 		}
1480 	}
1481 	return(0);
1482 
1483   sendpkt:
1484 	return((*ifp->if_output)(ifp, m, (struct sockaddr *)dst, rt));
1485 
1486   bad:
1487 	if (m)
1488 		m_freem(m);
1489 	return (error);
1490 }
1491 #undef senderr
1492 
1493 int
1494 nd6_storelladdr(ifp, rt, m, dst, desten)
1495 	struct ifnet *ifp;
1496 	struct rtentry *rt;
1497 	struct mbuf *m;
1498 	struct sockaddr *dst;
1499 	u_char *desten;
1500 {
1501 	struct sockaddr_dl *sdl;
1502 
1503 	if (m->m_flags & M_MCAST) {
1504 		switch (ifp->if_type) {
1505 		case IFT_ETHER:
1506 		case IFT_FDDI:
1507 			ETHER_MAP_IPV6_MULTICAST(&SIN6(dst)->sin6_addr,
1508 						 desten);
1509 			return(1);
1510 			break;
1511 		case IFT_ARCNET:
1512 			*desten = 0;
1513 			return(1);
1514 		default:
1515 			return(0);
1516 		}
1517 	}
1518 
1519 	if (rt == NULL ||
1520 	    rt->rt_gateway->sa_family != AF_LINK) {
1521 		printf("nd6_storelladdr: something odd happens\n");
1522 		return(0);
1523 	}
1524 	sdl = SDL(rt->rt_gateway);
1525 	if (sdl->sdl_alen != 0)
1526 		bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
1527 
1528 	return(1);
1529 }
1530