xref: /freebsd/sys/netinet6/nd6.c (revision 9034852c84a13f0e3b5527e1c886ca94b2863b2b)
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  *	$KAME: nd6.c,v 1.144 2001/05/24 07:44:00 itojun Exp $
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include "opt_inet.h"
36 #include "opt_inet6.h"
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/callout.h>
41 #include <sys/malloc.h>
42 #include <sys/mbuf.h>
43 #include <sys/socket.h>
44 #include <sys/sockio.h>
45 #include <sys/time.h>
46 #include <sys/kernel.h>
47 #include <sys/protosw.h>
48 #include <sys/errno.h>
49 #include <sys/syslog.h>
50 #include <sys/lock.h>
51 #include <sys/rwlock.h>
52 #include <sys/queue.h>
53 #include <sys/sdt.h>
54 #include <sys/sysctl.h>
55 
56 #include <net/if.h>
57 #include <net/if_var.h>
58 #include <net/if_arc.h>
59 #include <net/if_dl.h>
60 #include <net/if_types.h>
61 #include <net/iso88025.h>
62 #include <net/fddi.h>
63 #include <net/route.h>
64 #include <net/vnet.h>
65 
66 #include <netinet/in.h>
67 #include <netinet/in_kdtrace.h>
68 #include <net/if_llatbl.h>
69 #include <netinet/if_ether.h>
70 #include <netinet6/in6_var.h>
71 #include <netinet/ip6.h>
72 #include <netinet6/ip6_var.h>
73 #include <netinet6/scope6_var.h>
74 #include <netinet6/nd6.h>
75 #include <netinet6/in6_ifattach.h>
76 #include <netinet/icmp6.h>
77 #include <netinet6/send.h>
78 
79 #include <sys/limits.h>
80 
81 #include <security/mac/mac_framework.h>
82 
83 #define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */
84 #define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */
85 
86 #define SIN6(s) ((const struct sockaddr_in6 *)(s))
87 
88 /* timer values */
89 VNET_DEFINE(int, nd6_prune)	= 1;	/* walk list every 1 seconds */
90 VNET_DEFINE(int, nd6_delay)	= 5;	/* delay first probe time 5 second */
91 VNET_DEFINE(int, nd6_umaxtries)	= 3;	/* maximum unicast query */
92 VNET_DEFINE(int, nd6_mmaxtries)	= 3;	/* maximum multicast query */
93 VNET_DEFINE(int, nd6_useloopback) = 1;	/* use loopback interface for
94 					 * local traffic */
95 VNET_DEFINE(int, nd6_gctimer)	= (60 * 60 * 24); /* 1 day: garbage
96 					 * collection timer */
97 
98 /* preventing too many loops in ND option parsing */
99 static VNET_DEFINE(int, nd6_maxndopt) = 10; /* max # of ND options allowed */
100 
101 VNET_DEFINE(int, nd6_maxnudhint) = 0;	/* max # of subsequent upper
102 					 * layer hints */
103 static VNET_DEFINE(int, nd6_maxqueuelen) = 1; /* max pkts cached in unresolved
104 					 * ND entries */
105 #define	V_nd6_maxndopt			VNET(nd6_maxndopt)
106 #define	V_nd6_maxqueuelen		VNET(nd6_maxqueuelen)
107 
108 #ifdef ND6_DEBUG
109 VNET_DEFINE(int, nd6_debug) = 1;
110 #else
111 VNET_DEFINE(int, nd6_debug) = 0;
112 #endif
113 
114 static eventhandler_tag lle_event_eh;
115 
116 /* for debugging? */
117 #if 0
118 static int nd6_inuse, nd6_allocated;
119 #endif
120 
121 VNET_DEFINE(struct nd_drhead, nd_defrouter);
122 VNET_DEFINE(struct nd_prhead, nd_prefix);
123 
124 VNET_DEFINE(int, nd6_recalc_reachtm_interval) = ND6_RECALC_REACHTM_INTERVAL;
125 #define	V_nd6_recalc_reachtm_interval	VNET(nd6_recalc_reachtm_interval)
126 
127 int	(*send_sendso_input_hook)(struct mbuf *, struct ifnet *, int, int);
128 
129 static int nd6_is_new_addr_neighbor(const struct sockaddr_in6 *,
130 	struct ifnet *);
131 static void nd6_setmtu0(struct ifnet *, struct nd_ifinfo *);
132 static void nd6_slowtimo(void *);
133 static int regen_tmpaddr(struct in6_ifaddr *);
134 static void nd6_free(struct llentry *, int);
135 static void nd6_free_redirect(const struct llentry *);
136 static void nd6_llinfo_timer(void *);
137 static void nd6_llinfo_settimer_locked(struct llentry *, long);
138 static void clear_llinfo_pqueue(struct llentry *);
139 static void nd6_rtrequest(int, struct rtentry *, struct rt_addrinfo *);
140 static int nd6_resolve_slow(struct ifnet *, struct mbuf *,
141     const struct sockaddr_in6 *, u_char *, uint32_t *);
142 static int nd6_need_cache(struct ifnet *);
143 
144 
145 static VNET_DEFINE(struct callout, nd6_slowtimo_ch);
146 #define	V_nd6_slowtimo_ch		VNET(nd6_slowtimo_ch)
147 
148 VNET_DEFINE(struct callout, nd6_timer_ch);
149 
150 static void
151 nd6_lle_event(void *arg __unused, struct llentry *lle, int evt)
152 {
153 	struct rt_addrinfo rtinfo;
154 	struct sockaddr_in6 dst;
155 	struct sockaddr_dl gw;
156 	struct ifnet *ifp;
157 	int type;
158 
159 	LLE_WLOCK_ASSERT(lle);
160 
161 	if (lltable_get_af(lle->lle_tbl) != AF_INET6)
162 		return;
163 
164 	switch (evt) {
165 	case LLENTRY_RESOLVED:
166 		type = RTM_ADD;
167 		KASSERT(lle->la_flags & LLE_VALID,
168 		    ("%s: %p resolved but not valid?", __func__, lle));
169 		break;
170 	case LLENTRY_EXPIRED:
171 		type = RTM_DELETE;
172 		break;
173 	default:
174 		return;
175 	}
176 
177 	ifp = lltable_get_ifp(lle->lle_tbl);
178 
179 	bzero(&dst, sizeof(dst));
180 	bzero(&gw, sizeof(gw));
181 	bzero(&rtinfo, sizeof(rtinfo));
182 	lltable_fill_sa_entry(lle, (struct sockaddr *)&dst);
183 	dst.sin6_scope_id = in6_getscopezone(ifp,
184 	    in6_addrscope(&dst.sin6_addr));
185 	gw.sdl_len = sizeof(struct sockaddr_dl);
186 	gw.sdl_family = AF_LINK;
187 	gw.sdl_alen = ifp->if_addrlen;
188 	gw.sdl_index = ifp->if_index;
189 	gw.sdl_type = ifp->if_type;
190 	if (evt == LLENTRY_RESOLVED)
191 		bcopy(&lle->ll_addr, gw.sdl_data, ifp->if_addrlen);
192 	rtinfo.rti_info[RTAX_DST] = (struct sockaddr *)&dst;
193 	rtinfo.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&gw;
194 	rtinfo.rti_addrs = RTA_DST | RTA_GATEWAY;
195 	rt_missmsg_fib(type, &rtinfo, RTF_HOST | RTF_LLDATA | (
196 	    type == RTM_ADD ? RTF_UP: 0), 0, RT_DEFAULT_FIB);
197 }
198 
199 void
200 nd6_init(void)
201 {
202 
203 	LIST_INIT(&V_nd_prefix);
204 
205 	/* initialization of the default router list */
206 	TAILQ_INIT(&V_nd_defrouter);
207 
208 	/* start timer */
209 	callout_init(&V_nd6_slowtimo_ch, 0);
210 	callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
211 	    nd6_slowtimo, curvnet);
212 
213 	nd6_dad_init();
214 	if (IS_DEFAULT_VNET(curvnet))
215 		lle_event_eh = EVENTHANDLER_REGISTER(lle_event, nd6_lle_event,
216 		    NULL, EVENTHANDLER_PRI_ANY);
217 }
218 
219 #ifdef VIMAGE
220 void
221 nd6_destroy()
222 {
223 
224 	callout_drain(&V_nd6_slowtimo_ch);
225 	callout_drain(&V_nd6_timer_ch);
226 	if (IS_DEFAULT_VNET(curvnet))
227 		EVENTHANDLER_DEREGISTER(lle_event, lle_event_eh);
228 }
229 #endif
230 
231 struct nd_ifinfo *
232 nd6_ifattach(struct ifnet *ifp)
233 {
234 	struct nd_ifinfo *nd;
235 
236 	nd = (struct nd_ifinfo *)malloc(sizeof(*nd), M_IP6NDP, M_WAITOK|M_ZERO);
237 	nd->initialized = 1;
238 
239 	nd->chlim = IPV6_DEFHLIM;
240 	nd->basereachable = REACHABLE_TIME;
241 	nd->reachable = ND_COMPUTE_RTIME(nd->basereachable);
242 	nd->retrans = RETRANS_TIMER;
243 
244 	nd->flags = ND6_IFF_PERFORMNUD;
245 
246 	/* A loopback interface always has ND6_IFF_AUTO_LINKLOCAL.
247 	 * XXXHRS: Clear ND6_IFF_AUTO_LINKLOCAL on an IFT_BRIDGE interface by
248 	 * default regardless of the V_ip6_auto_linklocal configuration to
249 	 * give a reasonable default behavior.
250 	 */
251 	if ((V_ip6_auto_linklocal && ifp->if_type != IFT_BRIDGE) ||
252 	    (ifp->if_flags & IFF_LOOPBACK))
253 		nd->flags |= ND6_IFF_AUTO_LINKLOCAL;
254 	/*
255 	 * A loopback interface does not need to accept RTADV.
256 	 * XXXHRS: Clear ND6_IFF_ACCEPT_RTADV on an IFT_BRIDGE interface by
257 	 * default regardless of the V_ip6_accept_rtadv configuration to
258 	 * prevent the interface from accepting RA messages arrived
259 	 * on one of the member interfaces with ND6_IFF_ACCEPT_RTADV.
260 	 */
261 	if (V_ip6_accept_rtadv &&
262 	    !(ifp->if_flags & IFF_LOOPBACK) &&
263 	    (ifp->if_type != IFT_BRIDGE))
264 			nd->flags |= ND6_IFF_ACCEPT_RTADV;
265 	if (V_ip6_no_radr && !(ifp->if_flags & IFF_LOOPBACK))
266 		nd->flags |= ND6_IFF_NO_RADR;
267 
268 	/* XXX: we cannot call nd6_setmtu since ifp is not fully initialized */
269 	nd6_setmtu0(ifp, nd);
270 
271 	return nd;
272 }
273 
274 void
275 nd6_ifdetach(struct nd_ifinfo *nd)
276 {
277 
278 	free(nd, M_IP6NDP);
279 }
280 
281 /*
282  * Reset ND level link MTU. This function is called when the physical MTU
283  * changes, which means we might have to adjust the ND level MTU.
284  */
285 void
286 nd6_setmtu(struct ifnet *ifp)
287 {
288 
289 	nd6_setmtu0(ifp, ND_IFINFO(ifp));
290 }
291 
292 /* XXX todo: do not maintain copy of ifp->if_mtu in ndi->maxmtu */
293 void
294 nd6_setmtu0(struct ifnet *ifp, struct nd_ifinfo *ndi)
295 {
296 	u_int32_t omaxmtu;
297 
298 	omaxmtu = ndi->maxmtu;
299 
300 	switch (ifp->if_type) {
301 	case IFT_ARCNET:
302 		ndi->maxmtu = MIN(ARC_PHDS_MAXMTU, ifp->if_mtu); /* RFC2497 */
303 		break;
304 	case IFT_FDDI:
305 		ndi->maxmtu = MIN(FDDIIPMTU, ifp->if_mtu); /* RFC2467 */
306 		break;
307 	case IFT_ISO88025:
308 		 ndi->maxmtu = MIN(ISO88025_MAX_MTU, ifp->if_mtu);
309 		 break;
310 	default:
311 		ndi->maxmtu = ifp->if_mtu;
312 		break;
313 	}
314 
315 	/*
316 	 * Decreasing the interface MTU under IPV6 minimum MTU may cause
317 	 * undesirable situation.  We thus notify the operator of the change
318 	 * explicitly.  The check for omaxmtu is necessary to restrict the
319 	 * log to the case of changing the MTU, not initializing it.
320 	 */
321 	if (omaxmtu >= IPV6_MMTU && ndi->maxmtu < IPV6_MMTU) {
322 		log(LOG_NOTICE, "nd6_setmtu0: "
323 		    "new link MTU on %s (%lu) is too small for IPv6\n",
324 		    if_name(ifp), (unsigned long)ndi->maxmtu);
325 	}
326 
327 	if (ndi->maxmtu > V_in6_maxmtu)
328 		in6_setmaxmtu(); /* check all interfaces just in case */
329 
330 }
331 
332 void
333 nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts)
334 {
335 
336 	bzero(ndopts, sizeof(*ndopts));
337 	ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
338 	ndopts->nd_opts_last
339 		= (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len);
340 
341 	if (icmp6len == 0) {
342 		ndopts->nd_opts_done = 1;
343 		ndopts->nd_opts_search = NULL;
344 	}
345 }
346 
347 /*
348  * Take one ND option.
349  */
350 struct nd_opt_hdr *
351 nd6_option(union nd_opts *ndopts)
352 {
353 	struct nd_opt_hdr *nd_opt;
354 	int olen;
355 
356 	KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__));
357 	KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts",
358 	    __func__));
359 	if (ndopts->nd_opts_search == NULL)
360 		return NULL;
361 	if (ndopts->nd_opts_done)
362 		return NULL;
363 
364 	nd_opt = ndopts->nd_opts_search;
365 
366 	/* make sure nd_opt_len is inside the buffer */
367 	if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) {
368 		bzero(ndopts, sizeof(*ndopts));
369 		return NULL;
370 	}
371 
372 	olen = nd_opt->nd_opt_len << 3;
373 	if (olen == 0) {
374 		/*
375 		 * Message validation requires that all included
376 		 * options have a length that is greater than zero.
377 		 */
378 		bzero(ndopts, sizeof(*ndopts));
379 		return NULL;
380 	}
381 
382 	ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen);
383 	if (ndopts->nd_opts_search > ndopts->nd_opts_last) {
384 		/* option overruns the end of buffer, invalid */
385 		bzero(ndopts, sizeof(*ndopts));
386 		return NULL;
387 	} else if (ndopts->nd_opts_search == ndopts->nd_opts_last) {
388 		/* reached the end of options chain */
389 		ndopts->nd_opts_done = 1;
390 		ndopts->nd_opts_search = NULL;
391 	}
392 	return nd_opt;
393 }
394 
395 /*
396  * Parse multiple ND options.
397  * This function is much easier to use, for ND routines that do not need
398  * multiple options of the same type.
399  */
400 int
401 nd6_options(union nd_opts *ndopts)
402 {
403 	struct nd_opt_hdr *nd_opt;
404 	int i = 0;
405 
406 	KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__));
407 	KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts",
408 	    __func__));
409 	if (ndopts->nd_opts_search == NULL)
410 		return 0;
411 
412 	while (1) {
413 		nd_opt = nd6_option(ndopts);
414 		if (nd_opt == NULL && ndopts->nd_opts_last == NULL) {
415 			/*
416 			 * Message validation requires that all included
417 			 * options have a length that is greater than zero.
418 			 */
419 			ICMP6STAT_INC(icp6s_nd_badopt);
420 			bzero(ndopts, sizeof(*ndopts));
421 			return -1;
422 		}
423 
424 		if (nd_opt == NULL)
425 			goto skip1;
426 
427 		switch (nd_opt->nd_opt_type) {
428 		case ND_OPT_SOURCE_LINKADDR:
429 		case ND_OPT_TARGET_LINKADDR:
430 		case ND_OPT_MTU:
431 		case ND_OPT_REDIRECTED_HEADER:
432 		case ND_OPT_NONCE:
433 			if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
434 				nd6log((LOG_INFO,
435 				    "duplicated ND6 option found (type=%d)\n",
436 				    nd_opt->nd_opt_type));
437 				/* XXX bark? */
438 			} else {
439 				ndopts->nd_opt_array[nd_opt->nd_opt_type]
440 					= nd_opt;
441 			}
442 			break;
443 		case ND_OPT_PREFIX_INFORMATION:
444 			if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
445 				ndopts->nd_opt_array[nd_opt->nd_opt_type]
446 					= nd_opt;
447 			}
448 			ndopts->nd_opts_pi_end =
449 				(struct nd_opt_prefix_info *)nd_opt;
450 			break;
451 		/* What about ND_OPT_ROUTE_INFO? RFC 4191 */
452 		case ND_OPT_RDNSS:	/* RFC 6106 */
453 		case ND_OPT_DNSSL:	/* RFC 6106 */
454 			/*
455 			 * Silently ignore options we know and do not care about
456 			 * in the kernel.
457 			 */
458 			break;
459 		default:
460 			/*
461 			 * Unknown options must be silently ignored,
462 			 * to accomodate future extension to the protocol.
463 			 */
464 			nd6log((LOG_DEBUG,
465 			    "nd6_options: unsupported option %d - "
466 			    "option ignored\n", nd_opt->nd_opt_type));
467 		}
468 
469 skip1:
470 		i++;
471 		if (i > V_nd6_maxndopt) {
472 			ICMP6STAT_INC(icp6s_nd_toomanyopt);
473 			nd6log((LOG_INFO, "too many loop in nd opt\n"));
474 			break;
475 		}
476 
477 		if (ndopts->nd_opts_done)
478 			break;
479 	}
480 
481 	return 0;
482 }
483 
484 /*
485  * ND6 timer routine to handle ND6 entries
486  */
487 static void
488 nd6_llinfo_settimer_locked(struct llentry *ln, long tick)
489 {
490 	int canceled;
491 
492 	LLE_WLOCK_ASSERT(ln);
493 
494 	if (tick < 0) {
495 		ln->la_expire = 0;
496 		ln->ln_ntick = 0;
497 		canceled = callout_stop(&ln->lle_timer);
498 	} else {
499 		ln->la_expire = time_uptime + tick / hz;
500 		LLE_ADDREF(ln);
501 		if (tick > INT_MAX) {
502 			ln->ln_ntick = tick - INT_MAX;
503 			canceled = callout_reset(&ln->lle_timer, INT_MAX,
504 			    nd6_llinfo_timer, ln);
505 		} else {
506 			ln->ln_ntick = 0;
507 			canceled = callout_reset(&ln->lle_timer, tick,
508 			    nd6_llinfo_timer, ln);
509 		}
510 	}
511 	if (canceled)
512 		LLE_REMREF(ln);
513 }
514 
515 /*
516  * Gets source address of the first packet in hold queue
517  * and stores it in @src.
518  * Returns pointer to @src (if hold queue is not empty) or NULL.
519  *
520  * Set noinline to be dtrace-friendly
521  */
522 static __noinline struct in6_addr *
523 nd6_llinfo_get_holdsrc(struct llentry *ln, struct in6_addr *src)
524 {
525 	struct ip6_hdr hdr;
526 	struct mbuf *m;
527 
528 	if (ln->la_hold == NULL)
529 		return (NULL);
530 
531 	/*
532 	 * assume every packet in la_hold has the same IP header
533 	 */
534 	m = ln->la_hold;
535 	if (sizeof(hdr) > m->m_len)
536 		return (NULL);
537 
538 	m_copydata(m, 0, sizeof(hdr), (caddr_t)&hdr);
539 	*src = hdr.ip6_src;
540 
541 	return (src);
542 }
543 
544 /*
545  * Switch @lle state to new state optionally arming timers.
546  *
547  * Set noinline to be dtrace-friendly
548  */
549 __noinline void
550 nd6_llinfo_setstate(struct llentry *lle, int newstate)
551 {
552 	struct ifnet *ifp;
553 	long delay;
554 
555 	delay = 0;
556 
557 	switch (newstate) {
558 	case ND6_LLINFO_INCOMPLETE:
559 		ifp = lle->lle_tbl->llt_ifp;
560 		delay = (long)ND_IFINFO(ifp)->retrans * hz / 1000;
561 		break;
562 	case ND6_LLINFO_REACHABLE:
563 		if (!ND6_LLINFO_PERMANENT(lle)) {
564 			ifp = lle->lle_tbl->llt_ifp;
565 			delay = (long)ND_IFINFO(ifp)->reachable * hz;
566 		}
567 		break;
568 	case ND6_LLINFO_STALE:
569 		delay = (long)V_nd6_gctimer * hz;
570 		break;
571 	case ND6_LLINFO_DELAY:
572 		lle->la_asked = 0;
573 		delay = (long)V_nd6_delay * hz;
574 		break;
575 	}
576 
577 	if (delay > 0)
578 		nd6_llinfo_settimer_locked(lle, delay);
579 
580 	lle->ln_state = newstate;
581 }
582 
583 /*
584  * Timer-dependent part of nd state machine.
585  *
586  * Set noinline to be dtrace-friendly
587  */
588 static __noinline void
589 nd6_llinfo_timer(void *arg)
590 {
591 	struct llentry *ln;
592 	struct in6_addr *dst, *pdst, *psrc, src;
593 	struct ifnet *ifp;
594 	struct nd_ifinfo *ndi = NULL;
595 	int send_ns;
596 
597 	KASSERT(arg != NULL, ("%s: arg NULL", __func__));
598 	ln = (struct llentry *)arg;
599 	LLE_WLOCK(ln);
600 	if (callout_pending(&ln->lle_timer)) {
601 		/*
602 		 * Here we are a bit odd here in the treatment of
603 		 * active/pending. If the pending bit is set, it got
604 		 * rescheduled before I ran. The active
605 		 * bit we ignore, since if it was stopped
606 		 * in ll_tablefree() and was currently running
607 		 * it would have return 0 so the code would
608 		 * not have deleted it since the callout could
609 		 * not be stopped so we want to go through
610 		 * with the delete here now. If the callout
611 		 * was restarted, the pending bit will be back on and
612 		 * we just want to bail since the callout_reset would
613 		 * return 1 and our reference would have been removed
614 		 * by nd6_llinfo_settimer_locked above since canceled
615 		 * would have been 1.
616 		 */
617 		LLE_WUNLOCK(ln);
618 		return;
619 	}
620 	ifp = ln->lle_tbl->llt_ifp;
621 	CURVNET_SET(ifp->if_vnet);
622 	ndi = ND_IFINFO(ifp);
623 	send_ns = 0;
624 	dst = &ln->r_l3addr.addr6;
625 	pdst = dst;
626 
627 	if (ln->ln_ntick > 0) {
628 		if (ln->ln_ntick > INT_MAX) {
629 			ln->ln_ntick -= INT_MAX;
630 			nd6_llinfo_settimer_locked(ln, INT_MAX);
631 		} else {
632 			ln->ln_ntick = 0;
633 			nd6_llinfo_settimer_locked(ln, ln->ln_ntick);
634 		}
635 		goto done;
636 	}
637 
638 	if (ln->la_flags & LLE_STATIC) {
639 		goto done;
640 	}
641 
642 	if (ln->la_flags & LLE_DELETED) {
643 		nd6_free(ln, 0);
644 		ln = NULL;
645 		goto done;
646 	}
647 
648 	switch (ln->ln_state) {
649 	case ND6_LLINFO_INCOMPLETE:
650 		if (ln->la_asked < V_nd6_mmaxtries) {
651 			ln->la_asked++;
652 			send_ns = 1;
653 			/* Send NS to multicast address */
654 			pdst = NULL;
655 		} else {
656 			struct mbuf *m = ln->la_hold;
657 			if (m) {
658 				struct mbuf *m0;
659 
660 				/*
661 				 * assuming every packet in la_hold has the
662 				 * same IP header.  Send error after unlock.
663 				 */
664 				m0 = m->m_nextpkt;
665 				m->m_nextpkt = NULL;
666 				ln->la_hold = m0;
667 				clear_llinfo_pqueue(ln);
668 			}
669 			EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_TIMEDOUT);
670 			nd6_free(ln, 0);
671 			ln = NULL;
672 			if (m != NULL)
673 				icmp6_error2(m, ICMP6_DST_UNREACH,
674 				    ICMP6_DST_UNREACH_ADDR, 0, ifp);
675 		}
676 		break;
677 	case ND6_LLINFO_REACHABLE:
678 		if (!ND6_LLINFO_PERMANENT(ln))
679 			nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
680 		break;
681 
682 	case ND6_LLINFO_STALE:
683 		/* Garbage Collection(RFC 2461 5.3) */
684 		if (!ND6_LLINFO_PERMANENT(ln)) {
685 			EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_EXPIRED);
686 			nd6_free(ln, 1);
687 			ln = NULL;
688 		}
689 		break;
690 
691 	case ND6_LLINFO_DELAY:
692 		if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) {
693 			/* We need NUD */
694 			ln->la_asked = 1;
695 			nd6_llinfo_setstate(ln, ND6_LLINFO_PROBE);
696 			send_ns = 1;
697 		} else
698 			nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); /* XXX */
699 		break;
700 	case ND6_LLINFO_PROBE:
701 		if (ln->la_asked < V_nd6_umaxtries) {
702 			ln->la_asked++;
703 			send_ns = 1;
704 		} else {
705 			EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_EXPIRED);
706 			nd6_free(ln, 0);
707 			ln = NULL;
708 		}
709 		break;
710 	default:
711 		panic("%s: paths in a dark night can be confusing: %d",
712 		    __func__, ln->ln_state);
713 	}
714 done:
715 	if (send_ns != 0) {
716 		nd6_llinfo_settimer_locked(ln, (long)ndi->retrans * hz / 1000);
717 		psrc = nd6_llinfo_get_holdsrc(ln, &src);
718 		LLE_FREE_LOCKED(ln);
719 		ln = NULL;
720 		nd6_ns_output(ifp, psrc, pdst, dst, NULL);
721 	}
722 
723 	if (ln != NULL)
724 		LLE_FREE_LOCKED(ln);
725 	CURVNET_RESTORE();
726 }
727 
728 
729 /*
730  * ND6 timer routine to expire default route list and prefix list
731  */
732 void
733 nd6_timer(void *arg)
734 {
735 	CURVNET_SET((struct vnet *) arg);
736 	struct nd_defrouter *dr, *ndr;
737 	struct nd_prefix *pr, *npr;
738 	struct in6_ifaddr *ia6, *nia6;
739 
740 	callout_reset(&V_nd6_timer_ch, V_nd6_prune * hz,
741 	    nd6_timer, curvnet);
742 
743 	/* expire default router list */
744 	TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr) {
745 		if (dr->expire && dr->expire < time_uptime)
746 			defrtrlist_del(dr);
747 	}
748 
749 	/*
750 	 * expire interface addresses.
751 	 * in the past the loop was inside prefix expiry processing.
752 	 * However, from a stricter speci-confrmance standpoint, we should
753 	 * rather separate address lifetimes and prefix lifetimes.
754 	 *
755 	 * XXXRW: in6_ifaddrhead locking.
756 	 */
757   addrloop:
758 	TAILQ_FOREACH_SAFE(ia6, &V_in6_ifaddrhead, ia_link, nia6) {
759 		/* check address lifetime */
760 		if (IFA6_IS_INVALID(ia6)) {
761 			int regen = 0;
762 
763 			/*
764 			 * If the expiring address is temporary, try
765 			 * regenerating a new one.  This would be useful when
766 			 * we suspended a laptop PC, then turned it on after a
767 			 * period that could invalidate all temporary
768 			 * addresses.  Although we may have to restart the
769 			 * loop (see below), it must be after purging the
770 			 * address.  Otherwise, we'd see an infinite loop of
771 			 * regeneration.
772 			 */
773 			if (V_ip6_use_tempaddr &&
774 			    (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
775 				if (regen_tmpaddr(ia6) == 0)
776 					regen = 1;
777 			}
778 
779 			in6_purgeaddr(&ia6->ia_ifa);
780 
781 			if (regen)
782 				goto addrloop; /* XXX: see below */
783 		} else if (IFA6_IS_DEPRECATED(ia6)) {
784 			int oldflags = ia6->ia6_flags;
785 
786 			ia6->ia6_flags |= IN6_IFF_DEPRECATED;
787 
788 			/*
789 			 * If a temporary address has just become deprecated,
790 			 * regenerate a new one if possible.
791 			 */
792 			if (V_ip6_use_tempaddr &&
793 			    (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
794 			    (oldflags & IN6_IFF_DEPRECATED) == 0) {
795 
796 				if (regen_tmpaddr(ia6) == 0) {
797 					/*
798 					 * A new temporary address is
799 					 * generated.
800 					 * XXX: this means the address chain
801 					 * has changed while we are still in
802 					 * the loop.  Although the change
803 					 * would not cause disaster (because
804 					 * it's not a deletion, but an
805 					 * addition,) we'd rather restart the
806 					 * loop just for safety.  Or does this
807 					 * significantly reduce performance??
808 					 */
809 					goto addrloop;
810 				}
811 			}
812 		} else if ((ia6->ia6_flags & IN6_IFF_TENTATIVE) != 0) {
813 			/*
814 			 * Schedule DAD for a tentative address.  This happens
815 			 * if the interface was down or not running
816 			 * when the address was configured.
817 			 */
818 			int delay;
819 
820 			delay = arc4random() %
821 			    (MAX_RTR_SOLICITATION_DELAY * hz);
822 			nd6_dad_start((struct ifaddr *)ia6, delay);
823 		} else {
824 			/*
825 			 * Check status of the interface.  If it is down,
826 			 * mark the address as tentative for future DAD.
827 			 */
828 			if ((ia6->ia_ifp->if_flags & IFF_UP) == 0 ||
829 			    (ia6->ia_ifp->if_drv_flags & IFF_DRV_RUNNING)
830 				== 0 ||
831 			    (ND_IFINFO(ia6->ia_ifp)->flags &
832 				ND6_IFF_IFDISABLED) != 0) {
833 				ia6->ia6_flags &= ~IN6_IFF_DUPLICATED;
834 				ia6->ia6_flags |= IN6_IFF_TENTATIVE;
835 			}
836 			/*
837 			 * A new RA might have made a deprecated address
838 			 * preferred.
839 			 */
840 			ia6->ia6_flags &= ~IN6_IFF_DEPRECATED;
841 		}
842 	}
843 
844 	/* expire prefix list */
845 	LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
846 		/*
847 		 * check prefix lifetime.
848 		 * since pltime is just for autoconf, pltime processing for
849 		 * prefix is not necessary.
850 		 */
851 		if (pr->ndpr_vltime != ND6_INFINITE_LIFETIME &&
852 		    time_uptime - pr->ndpr_lastupdate > pr->ndpr_vltime) {
853 
854 			/*
855 			 * address expiration and prefix expiration are
856 			 * separate.  NEVER perform in6_purgeaddr here.
857 			 */
858 			prelist_remove(pr);
859 		}
860 	}
861 	CURVNET_RESTORE();
862 }
863 
864 /*
865  * ia6 - deprecated/invalidated temporary address
866  */
867 static int
868 regen_tmpaddr(struct in6_ifaddr *ia6)
869 {
870 	struct ifaddr *ifa;
871 	struct ifnet *ifp;
872 	struct in6_ifaddr *public_ifa6 = NULL;
873 
874 	ifp = ia6->ia_ifa.ifa_ifp;
875 	IF_ADDR_RLOCK(ifp);
876 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
877 		struct in6_ifaddr *it6;
878 
879 		if (ifa->ifa_addr->sa_family != AF_INET6)
880 			continue;
881 
882 		it6 = (struct in6_ifaddr *)ifa;
883 
884 		/* ignore no autoconf addresses. */
885 		if ((it6->ia6_flags & IN6_IFF_AUTOCONF) == 0)
886 			continue;
887 
888 		/* ignore autoconf addresses with different prefixes. */
889 		if (it6->ia6_ndpr == NULL || it6->ia6_ndpr != ia6->ia6_ndpr)
890 			continue;
891 
892 		/*
893 		 * Now we are looking at an autoconf address with the same
894 		 * prefix as ours.  If the address is temporary and is still
895 		 * preferred, do not create another one.  It would be rare, but
896 		 * could happen, for example, when we resume a laptop PC after
897 		 * a long period.
898 		 */
899 		if ((it6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
900 		    !IFA6_IS_DEPRECATED(it6)) {
901 			public_ifa6 = NULL;
902 			break;
903 		}
904 
905 		/*
906 		 * This is a public autoconf address that has the same prefix
907 		 * as ours.  If it is preferred, keep it.  We can't break the
908 		 * loop here, because there may be a still-preferred temporary
909 		 * address with the prefix.
910 		 */
911 		if (!IFA6_IS_DEPRECATED(it6))
912 			public_ifa6 = it6;
913 	}
914 	if (public_ifa6 != NULL)
915 		ifa_ref(&public_ifa6->ia_ifa);
916 	IF_ADDR_RUNLOCK(ifp);
917 
918 	if (public_ifa6 != NULL) {
919 		int e;
920 
921 		if ((e = in6_tmpifadd(public_ifa6, 0, 0)) != 0) {
922 			ifa_free(&public_ifa6->ia_ifa);
923 			log(LOG_NOTICE, "regen_tmpaddr: failed to create a new"
924 			    " tmp addr,errno=%d\n", e);
925 			return (-1);
926 		}
927 		ifa_free(&public_ifa6->ia_ifa);
928 		return (0);
929 	}
930 
931 	return (-1);
932 }
933 
934 /*
935  * Nuke neighbor cache/prefix/default router management table, right before
936  * ifp goes away.
937  */
938 void
939 nd6_purge(struct ifnet *ifp)
940 {
941 	struct nd_defrouter *dr, *ndr;
942 	struct nd_prefix *pr, *npr;
943 
944 	/*
945 	 * Nuke default router list entries toward ifp.
946 	 * We defer removal of default router list entries that is installed
947 	 * in the routing table, in order to keep additional side effects as
948 	 * small as possible.
949 	 */
950 	TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr) {
951 		if (dr->installed)
952 			continue;
953 
954 		if (dr->ifp == ifp)
955 			defrtrlist_del(dr);
956 	}
957 
958 	TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr) {
959 		if (!dr->installed)
960 			continue;
961 
962 		if (dr->ifp == ifp)
963 			defrtrlist_del(dr);
964 	}
965 
966 	/* Nuke prefix list entries toward ifp */
967 	LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
968 		if (pr->ndpr_ifp == ifp) {
969 			/*
970 			 * Because if_detach() does *not* release prefixes
971 			 * while purging addresses the reference count will
972 			 * still be above zero. We therefore reset it to
973 			 * make sure that the prefix really gets purged.
974 			 */
975 			pr->ndpr_refcnt = 0;
976 
977 			/*
978 			 * Previously, pr->ndpr_addr is removed as well,
979 			 * but I strongly believe we don't have to do it.
980 			 * nd6_purge() is only called from in6_ifdetach(),
981 			 * which removes all the associated interface addresses
982 			 * by itself.
983 			 * (jinmei@kame.net 20010129)
984 			 */
985 			prelist_remove(pr);
986 		}
987 	}
988 
989 	/* cancel default outgoing interface setting */
990 	if (V_nd6_defifindex == ifp->if_index)
991 		nd6_setdefaultiface(0);
992 
993 	if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
994 		/* Refresh default router list. */
995 		defrouter_select();
996 	}
997 
998 	/* XXXXX
999 	 * We do not nuke the neighbor cache entries here any more
1000 	 * because the neighbor cache is kept in if_afdata[AF_INET6].
1001 	 * nd6_purge() is invoked by in6_ifdetach() which is called
1002 	 * from if_detach() where everything gets purged. So let
1003 	 * in6_domifdetach() do the actual L2 table purging work.
1004 	 */
1005 }
1006 
1007 /*
1008  * the caller acquires and releases the lock on the lltbls
1009  * Returns the llentry locked
1010  */
1011 struct llentry *
1012 nd6_lookup(const struct in6_addr *addr6, int flags, struct ifnet *ifp)
1013 {
1014 	struct sockaddr_in6 sin6;
1015 	struct llentry *ln;
1016 
1017 	bzero(&sin6, sizeof(sin6));
1018 	sin6.sin6_len = sizeof(struct sockaddr_in6);
1019 	sin6.sin6_family = AF_INET6;
1020 	sin6.sin6_addr = *addr6;
1021 
1022 	IF_AFDATA_LOCK_ASSERT(ifp);
1023 
1024 	ln = lla_lookup(LLTABLE6(ifp), flags, (struct sockaddr *)&sin6);
1025 
1026 	return (ln);
1027 }
1028 
1029 struct llentry *
1030 nd6_alloc(const struct in6_addr *addr6, int flags, struct ifnet *ifp)
1031 {
1032 	struct sockaddr_in6 sin6;
1033 	struct llentry *ln;
1034 
1035 	bzero(&sin6, sizeof(sin6));
1036 	sin6.sin6_len = sizeof(struct sockaddr_in6);
1037 	sin6.sin6_family = AF_INET6;
1038 	sin6.sin6_addr = *addr6;
1039 
1040 	ln = lltable_alloc_entry(LLTABLE6(ifp), 0, (struct sockaddr *)&sin6);
1041 	if (ln != NULL)
1042 		ln->ln_state = ND6_LLINFO_NOSTATE;
1043 
1044 	return (ln);
1045 }
1046 
1047 /*
1048  * Test whether a given IPv6 address is a neighbor or not, ignoring
1049  * the actual neighbor cache.  The neighbor cache is ignored in order
1050  * to not reenter the routing code from within itself.
1051  */
1052 static int
1053 nd6_is_new_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp)
1054 {
1055 	struct nd_prefix *pr;
1056 	struct ifaddr *dstaddr;
1057 
1058 	/*
1059 	 * A link-local address is always a neighbor.
1060 	 * XXX: a link does not necessarily specify a single interface.
1061 	 */
1062 	if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) {
1063 		struct sockaddr_in6 sin6_copy;
1064 		u_int32_t zone;
1065 
1066 		/*
1067 		 * We need sin6_copy since sa6_recoverscope() may modify the
1068 		 * content (XXX).
1069 		 */
1070 		sin6_copy = *addr;
1071 		if (sa6_recoverscope(&sin6_copy))
1072 			return (0); /* XXX: should be impossible */
1073 		if (in6_setscope(&sin6_copy.sin6_addr, ifp, &zone))
1074 			return (0);
1075 		if (sin6_copy.sin6_scope_id == zone)
1076 			return (1);
1077 		else
1078 			return (0);
1079 	}
1080 
1081 	/*
1082 	 * If the address matches one of our addresses,
1083 	 * it should be a neighbor.
1084 	 * If the address matches one of our on-link prefixes, it should be a
1085 	 * neighbor.
1086 	 */
1087 	LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
1088 		if (pr->ndpr_ifp != ifp)
1089 			continue;
1090 
1091 		if (!(pr->ndpr_stateflags & NDPRF_ONLINK)) {
1092 			struct rtentry *rt;
1093 
1094 			/* Always use the default FIB here. */
1095 			rt = in6_rtalloc1((struct sockaddr *)&pr->ndpr_prefix,
1096 			    0, 0, RT_DEFAULT_FIB);
1097 			if (rt == NULL)
1098 				continue;
1099 			/*
1100 			 * This is the case where multiple interfaces
1101 			 * have the same prefix, but only one is installed
1102 			 * into the routing table and that prefix entry
1103 			 * is not the one being examined here. In the case
1104 			 * where RADIX_MPATH is enabled, multiple route
1105 			 * entries (of the same rt_key value) will be
1106 			 * installed because the interface addresses all
1107 			 * differ.
1108 			 */
1109 			if (!IN6_ARE_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
1110 			       &((struct sockaddr_in6 *)rt_key(rt))->sin6_addr)) {
1111 				RTFREE_LOCKED(rt);
1112 				continue;
1113 			}
1114 			RTFREE_LOCKED(rt);
1115 		}
1116 
1117 		if (IN6_ARE_MASKED_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
1118 		    &addr->sin6_addr, &pr->ndpr_mask))
1119 			return (1);
1120 	}
1121 
1122 	/*
1123 	 * If the address is assigned on the node of the other side of
1124 	 * a p2p interface, the address should be a neighbor.
1125 	 */
1126 	dstaddr = ifa_ifwithdstaddr((const struct sockaddr *)addr, RT_ALL_FIBS);
1127 	if (dstaddr != NULL) {
1128 		if (dstaddr->ifa_ifp == ifp) {
1129 			ifa_free(dstaddr);
1130 			return (1);
1131 		}
1132 		ifa_free(dstaddr);
1133 	}
1134 
1135 	/*
1136 	 * If the default router list is empty, all addresses are regarded
1137 	 * as on-link, and thus, as a neighbor.
1138 	 */
1139 	if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV &&
1140 	    TAILQ_EMPTY(&V_nd_defrouter) &&
1141 	    V_nd6_defifindex == ifp->if_index) {
1142 		return (1);
1143 	}
1144 
1145 	return (0);
1146 }
1147 
1148 
1149 /*
1150  * Detect if a given IPv6 address identifies a neighbor on a given link.
1151  * XXX: should take care of the destination of a p2p link?
1152  */
1153 int
1154 nd6_is_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp)
1155 {
1156 	struct llentry *lle;
1157 	int rc = 0;
1158 
1159 	IF_AFDATA_UNLOCK_ASSERT(ifp);
1160 	if (nd6_is_new_addr_neighbor(addr, ifp))
1161 		return (1);
1162 
1163 	/*
1164 	 * Even if the address matches none of our addresses, it might be
1165 	 * in the neighbor cache.
1166 	 */
1167 	IF_AFDATA_RLOCK(ifp);
1168 	if ((lle = nd6_lookup(&addr->sin6_addr, 0, ifp)) != NULL) {
1169 		LLE_RUNLOCK(lle);
1170 		rc = 1;
1171 	}
1172 	IF_AFDATA_RUNLOCK(ifp);
1173 	return (rc);
1174 }
1175 
1176 /*
1177  * Free an nd6 llinfo entry.
1178  * Since the function would cause significant changes in the kernel, DO NOT
1179  * make it global, unless you have a strong reason for the change, and are sure
1180  * that the change is safe.
1181  *
1182  * Set noinline to be dtrace-friendly
1183  */
1184 static __noinline void
1185 nd6_free(struct llentry *ln, int gc)
1186 {
1187 	struct nd_defrouter *dr;
1188 	struct ifnet *ifp;
1189 
1190 	LLE_WLOCK_ASSERT(ln);
1191 
1192 	/*
1193 	 * we used to have pfctlinput(PRC_HOSTDEAD) here.
1194 	 * even though it is not harmful, it was not really necessary.
1195 	 */
1196 
1197 	/* cancel timer */
1198 	nd6_llinfo_settimer_locked(ln, -1);
1199 
1200 	ifp = ln->lle_tbl->llt_ifp;
1201 
1202 	if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
1203 		dr = defrouter_lookup(&ln->r_l3addr.addr6, ifp);
1204 
1205 		if (dr != NULL && dr->expire &&
1206 		    ln->ln_state == ND6_LLINFO_STALE && gc) {
1207 			/*
1208 			 * If the reason for the deletion is just garbage
1209 			 * collection, and the neighbor is an active default
1210 			 * router, do not delete it.  Instead, reset the GC
1211 			 * timer using the router's lifetime.
1212 			 * Simply deleting the entry would affect default
1213 			 * router selection, which is not necessarily a good
1214 			 * thing, especially when we're using router preference
1215 			 * values.
1216 			 * XXX: the check for ln_state would be redundant,
1217 			 *      but we intentionally keep it just in case.
1218 			 */
1219 			if (dr->expire > time_uptime)
1220 				nd6_llinfo_settimer_locked(ln,
1221 				    (dr->expire - time_uptime) * hz);
1222 			else
1223 				nd6_llinfo_settimer_locked(ln,
1224 				    (long)V_nd6_gctimer * hz);
1225 
1226 			LLE_REMREF(ln);
1227 			LLE_WUNLOCK(ln);
1228 			return;
1229 		}
1230 
1231 		if (dr) {
1232 			/*
1233 			 * Unreachablity of a router might affect the default
1234 			 * router selection and on-link detection of advertised
1235 			 * prefixes.
1236 			 */
1237 
1238 			/*
1239 			 * Temporarily fake the state to choose a new default
1240 			 * router and to perform on-link determination of
1241 			 * prefixes correctly.
1242 			 * Below the state will be set correctly,
1243 			 * or the entry itself will be deleted.
1244 			 */
1245 			ln->ln_state = ND6_LLINFO_INCOMPLETE;
1246 		}
1247 
1248 		if (ln->ln_router || dr) {
1249 
1250 			/*
1251 			 * We need to unlock to avoid a LOR with rt6_flush() with the
1252 			 * rnh and for the calls to pfxlist_onlink_check() and
1253 			 * defrouter_select() in the block further down for calls
1254 			 * into nd6_lookup().  We still hold a ref.
1255 			 */
1256 			LLE_WUNLOCK(ln);
1257 
1258 			/*
1259 			 * rt6_flush must be called whether or not the neighbor
1260 			 * is in the Default Router List.
1261 			 * See a corresponding comment in nd6_na_input().
1262 			 */
1263 			rt6_flush(&ln->r_l3addr.addr6, ifp);
1264 		}
1265 
1266 		if (dr) {
1267 			/*
1268 			 * Since defrouter_select() does not affect the
1269 			 * on-link determination and MIP6 needs the check
1270 			 * before the default router selection, we perform
1271 			 * the check now.
1272 			 */
1273 			pfxlist_onlink_check();
1274 
1275 			/*
1276 			 * Refresh default router list.
1277 			 */
1278 			defrouter_select();
1279 		}
1280 
1281 		/*
1282 		 * If this entry was added by an on-link redirect, remove the
1283 		 * corresponding host route.
1284 		 */
1285 		if (ln->la_flags & LLE_REDIRECT)
1286 			nd6_free_redirect(ln);
1287 
1288 		if (ln->ln_router || dr)
1289 			LLE_WLOCK(ln);
1290 	}
1291 
1292 	/*
1293 	 * Save to unlock. We still hold an extra reference and will not
1294 	 * free(9) in llentry_free() if someone else holds one as well.
1295 	 */
1296 	LLE_WUNLOCK(ln);
1297 	IF_AFDATA_LOCK(ifp);
1298 	LLE_WLOCK(ln);
1299 	/* Guard against race with other llentry_free(). */
1300 	if (ln->la_flags & LLE_LINKED) {
1301 		/* Remove callout reference */
1302 		LLE_REMREF(ln);
1303 		lltable_unlink_entry(ln->lle_tbl, ln);
1304 	}
1305 	IF_AFDATA_UNLOCK(ifp);
1306 
1307 	llentry_free(ln);
1308 }
1309 
1310 /*
1311  * Remove the rtentry for the given llentry,
1312  * both of which were installed by a redirect.
1313  */
1314 static void
1315 nd6_free_redirect(const struct llentry *ln)
1316 {
1317 	int fibnum;
1318 	struct rtentry *rt;
1319 	struct radix_node_head *rnh;
1320 	struct sockaddr_in6 sin6;
1321 
1322 	lltable_fill_sa_entry(ln, (struct sockaddr *)&sin6);
1323 	for (fibnum = 0; fibnum < rt_numfibs; fibnum++) {
1324 		rnh = rt_tables_get_rnh(fibnum, AF_INET6);
1325 		if (rnh == NULL)
1326 			continue;
1327 
1328 		RADIX_NODE_HEAD_LOCK(rnh);
1329 		rt = in6_rtalloc1((struct sockaddr *)&sin6, 0,
1330 		    RTF_RNH_LOCKED, fibnum);
1331 		if (rt) {
1332 			if (rt->rt_flags == (RTF_UP | RTF_HOST | RTF_DYNAMIC))
1333 				rt_expunge(rnh, rt);
1334 			RTFREE_LOCKED(rt);
1335 		}
1336 		RADIX_NODE_HEAD_UNLOCK(rnh);
1337 	}
1338 }
1339 
1340 /*
1341  * Rejuvenate this function for routing operations related
1342  * processing.
1343  */
1344 void
1345 nd6_rtrequest(int req, struct rtentry *rt, struct rt_addrinfo *info)
1346 {
1347 	struct sockaddr_in6 *gateway;
1348 	struct nd_defrouter *dr;
1349 	struct ifnet *ifp;
1350 
1351 	gateway = (struct sockaddr_in6 *)rt->rt_gateway;
1352 	ifp = rt->rt_ifp;
1353 
1354 	switch (req) {
1355 	case RTM_ADD:
1356 		break;
1357 
1358 	case RTM_DELETE:
1359 		if (!ifp)
1360 			return;
1361 		/*
1362 		 * Only indirect routes are interesting.
1363 		 */
1364 		if ((rt->rt_flags & RTF_GATEWAY) == 0)
1365 			return;
1366 		/*
1367 		 * check for default route
1368 		 */
1369 		if (IN6_ARE_ADDR_EQUAL(&in6addr_any,
1370 				       &SIN6(rt_key(rt))->sin6_addr)) {
1371 
1372 			dr = defrouter_lookup(&gateway->sin6_addr, ifp);
1373 			if (dr != NULL)
1374 				dr->installed = 0;
1375 		}
1376 		break;
1377 	}
1378 }
1379 
1380 
1381 int
1382 nd6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp)
1383 {
1384 	struct in6_ndireq *ndi = (struct in6_ndireq *)data;
1385 	struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data;
1386 	struct in6_ndifreq *ndif = (struct in6_ndifreq *)data;
1387 	int error = 0;
1388 
1389 	if (ifp->if_afdata[AF_INET6] == NULL)
1390 		return (EPFNOSUPPORT);
1391 	switch (cmd) {
1392 	case OSIOCGIFINFO_IN6:
1393 #define ND	ndi->ndi
1394 		/* XXX: old ndp(8) assumes a positive value for linkmtu. */
1395 		bzero(&ND, sizeof(ND));
1396 		ND.linkmtu = IN6_LINKMTU(ifp);
1397 		ND.maxmtu = ND_IFINFO(ifp)->maxmtu;
1398 		ND.basereachable = ND_IFINFO(ifp)->basereachable;
1399 		ND.reachable = ND_IFINFO(ifp)->reachable;
1400 		ND.retrans = ND_IFINFO(ifp)->retrans;
1401 		ND.flags = ND_IFINFO(ifp)->flags;
1402 		ND.recalctm = ND_IFINFO(ifp)->recalctm;
1403 		ND.chlim = ND_IFINFO(ifp)->chlim;
1404 		break;
1405 	case SIOCGIFINFO_IN6:
1406 		ND = *ND_IFINFO(ifp);
1407 		break;
1408 	case SIOCSIFINFO_IN6:
1409 		/*
1410 		 * used to change host variables from userland.
1411 		 * intented for a use on router to reflect RA configurations.
1412 		 */
1413 		/* 0 means 'unspecified' */
1414 		if (ND.linkmtu != 0) {
1415 			if (ND.linkmtu < IPV6_MMTU ||
1416 			    ND.linkmtu > IN6_LINKMTU(ifp)) {
1417 				error = EINVAL;
1418 				break;
1419 			}
1420 			ND_IFINFO(ifp)->linkmtu = ND.linkmtu;
1421 		}
1422 
1423 		if (ND.basereachable != 0) {
1424 			int obasereachable = ND_IFINFO(ifp)->basereachable;
1425 
1426 			ND_IFINFO(ifp)->basereachable = ND.basereachable;
1427 			if (ND.basereachable != obasereachable)
1428 				ND_IFINFO(ifp)->reachable =
1429 				    ND_COMPUTE_RTIME(ND.basereachable);
1430 		}
1431 		if (ND.retrans != 0)
1432 			ND_IFINFO(ifp)->retrans = ND.retrans;
1433 		if (ND.chlim != 0)
1434 			ND_IFINFO(ifp)->chlim = ND.chlim;
1435 		/* FALLTHROUGH */
1436 	case SIOCSIFINFO_FLAGS:
1437 	{
1438 		struct ifaddr *ifa;
1439 		struct in6_ifaddr *ia;
1440 
1441 		if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
1442 		    !(ND.flags & ND6_IFF_IFDISABLED)) {
1443 			/* ifdisabled 1->0 transision */
1444 
1445 			/*
1446 			 * If the interface is marked as ND6_IFF_IFDISABLED and
1447 			 * has an link-local address with IN6_IFF_DUPLICATED,
1448 			 * do not clear ND6_IFF_IFDISABLED.
1449 			 * See RFC 4862, Section 5.4.5.
1450 			 */
1451 			IF_ADDR_RLOCK(ifp);
1452 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1453 				if (ifa->ifa_addr->sa_family != AF_INET6)
1454 					continue;
1455 				ia = (struct in6_ifaddr *)ifa;
1456 				if ((ia->ia6_flags & IN6_IFF_DUPLICATED) &&
1457 				    IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia)))
1458 					break;
1459 			}
1460 			IF_ADDR_RUNLOCK(ifp);
1461 
1462 			if (ifa != NULL) {
1463 				/* LLA is duplicated. */
1464 				ND.flags |= ND6_IFF_IFDISABLED;
1465 				log(LOG_ERR, "Cannot enable an interface"
1466 				    " with a link-local address marked"
1467 				    " duplicate.\n");
1468 			} else {
1469 				ND_IFINFO(ifp)->flags &= ~ND6_IFF_IFDISABLED;
1470 				if (ifp->if_flags & IFF_UP)
1471 					in6_if_up(ifp);
1472 			}
1473 		} else if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
1474 			    (ND.flags & ND6_IFF_IFDISABLED)) {
1475 			/* ifdisabled 0->1 transision */
1476 			/* Mark all IPv6 address as tentative. */
1477 
1478 			ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
1479 			if (V_ip6_dad_count > 0 &&
1480 			    (ND_IFINFO(ifp)->flags & ND6_IFF_NO_DAD) == 0) {
1481 				IF_ADDR_RLOCK(ifp);
1482 				TAILQ_FOREACH(ifa, &ifp->if_addrhead,
1483 				    ifa_link) {
1484 					if (ifa->ifa_addr->sa_family !=
1485 					    AF_INET6)
1486 						continue;
1487 					ia = (struct in6_ifaddr *)ifa;
1488 					ia->ia6_flags |= IN6_IFF_TENTATIVE;
1489 				}
1490 				IF_ADDR_RUNLOCK(ifp);
1491 			}
1492 		}
1493 
1494 		if (ND.flags & ND6_IFF_AUTO_LINKLOCAL) {
1495 			if (!(ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL)) {
1496 				/* auto_linklocal 0->1 transision */
1497 
1498 				/* If no link-local address on ifp, configure */
1499 				ND_IFINFO(ifp)->flags |= ND6_IFF_AUTO_LINKLOCAL;
1500 				in6_ifattach(ifp, NULL);
1501 			} else if (!(ND.flags & ND6_IFF_IFDISABLED) &&
1502 			    ifp->if_flags & IFF_UP) {
1503 				/*
1504 				 * When the IF already has
1505 				 * ND6_IFF_AUTO_LINKLOCAL, no link-local
1506 				 * address is assigned, and IFF_UP, try to
1507 				 * assign one.
1508 				 */
1509 				IF_ADDR_RLOCK(ifp);
1510 				TAILQ_FOREACH(ifa, &ifp->if_addrhead,
1511 				    ifa_link) {
1512 					if (ifa->ifa_addr->sa_family !=
1513 					    AF_INET6)
1514 						continue;
1515 					ia = (struct in6_ifaddr *)ifa;
1516 					if (IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia)))
1517 						break;
1518 				}
1519 				IF_ADDR_RUNLOCK(ifp);
1520 				if (ifa != NULL)
1521 					/* No LLA is configured. */
1522 					in6_ifattach(ifp, NULL);
1523 			}
1524 		}
1525 	}
1526 		ND_IFINFO(ifp)->flags = ND.flags;
1527 		break;
1528 #undef ND
1529 	case SIOCSNDFLUSH_IN6:	/* XXX: the ioctl name is confusing... */
1530 		/* sync kernel routing table with the default router list */
1531 		defrouter_reset();
1532 		defrouter_select();
1533 		break;
1534 	case SIOCSPFXFLUSH_IN6:
1535 	{
1536 		/* flush all the prefix advertised by routers */
1537 		struct nd_prefix *pr, *next;
1538 
1539 		LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, next) {
1540 			struct in6_ifaddr *ia, *ia_next;
1541 
1542 			if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1543 				continue; /* XXX */
1544 
1545 			/* do we really have to remove addresses as well? */
1546 			/* XXXRW: in6_ifaddrhead locking. */
1547 			TAILQ_FOREACH_SAFE(ia, &V_in6_ifaddrhead, ia_link,
1548 			    ia_next) {
1549 				if ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1550 					continue;
1551 
1552 				if (ia->ia6_ndpr == pr)
1553 					in6_purgeaddr(&ia->ia_ifa);
1554 			}
1555 			prelist_remove(pr);
1556 		}
1557 		break;
1558 	}
1559 	case SIOCSRTRFLUSH_IN6:
1560 	{
1561 		/* flush all the default routers */
1562 		struct nd_defrouter *dr, *next;
1563 
1564 		defrouter_reset();
1565 		TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, next) {
1566 			defrtrlist_del(dr);
1567 		}
1568 		defrouter_select();
1569 		break;
1570 	}
1571 	case SIOCGNBRINFO_IN6:
1572 	{
1573 		struct llentry *ln;
1574 		struct in6_addr nb_addr = nbi->addr; /* make local for safety */
1575 
1576 		if ((error = in6_setscope(&nb_addr, ifp, NULL)) != 0)
1577 			return (error);
1578 
1579 		IF_AFDATA_RLOCK(ifp);
1580 		ln = nd6_lookup(&nb_addr, 0, ifp);
1581 		IF_AFDATA_RUNLOCK(ifp);
1582 
1583 		if (ln == NULL) {
1584 			error = EINVAL;
1585 			break;
1586 		}
1587 		nbi->state = ln->ln_state;
1588 		nbi->asked = ln->la_asked;
1589 		nbi->isrouter = ln->ln_router;
1590 		if (ln->la_expire == 0)
1591 			nbi->expire = 0;
1592 		else
1593 			nbi->expire = ln->la_expire +
1594 			    (time_second - time_uptime);
1595 		LLE_RUNLOCK(ln);
1596 		break;
1597 	}
1598 	case SIOCGDEFIFACE_IN6:	/* XXX: should be implemented as a sysctl? */
1599 		ndif->ifindex = V_nd6_defifindex;
1600 		break;
1601 	case SIOCSDEFIFACE_IN6:	/* XXX: should be implemented as a sysctl? */
1602 		return (nd6_setdefaultiface(ndif->ifindex));
1603 	}
1604 	return (error);
1605 }
1606 
1607 /*
1608  * Calculates new isRouter value based on provided parameters and
1609  * returns it.
1610  */
1611 static int
1612 nd6_is_router(int type, int code, int is_new, int old_addr, int new_addr,
1613     int ln_router)
1614 {
1615 
1616 	/*
1617 	 * ICMP6 type dependent behavior.
1618 	 *
1619 	 * NS: clear IsRouter if new entry
1620 	 * RS: clear IsRouter
1621 	 * RA: set IsRouter if there's lladdr
1622 	 * redir: clear IsRouter if new entry
1623 	 *
1624 	 * RA case, (1):
1625 	 * The spec says that we must set IsRouter in the following cases:
1626 	 * - If lladdr exist, set IsRouter.  This means (1-5).
1627 	 * - If it is old entry (!newentry), set IsRouter.  This means (7).
1628 	 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
1629 	 * A quetion arises for (1) case.  (1) case has no lladdr in the
1630 	 * neighbor cache, this is similar to (6).
1631 	 * This case is rare but we figured that we MUST NOT set IsRouter.
1632 	 *
1633 	 *   is_new  old_addr new_addr 	    NS  RS  RA	redir
1634 	 *							D R
1635 	 *	0	n	n	(1)	c   ?     s
1636 	 *	0	y	n	(2)	c   s     s
1637 	 *	0	n	y	(3)	c   s     s
1638 	 *	0	y	y	(4)	c   s     s
1639 	 *	0	y	y	(5)	c   s     s
1640 	 *	1	--	n	(6) c	c	c s
1641 	 *	1	--	y	(7) c	c   s	c s
1642 	 *
1643 	 *					(c=clear s=set)
1644 	 */
1645 	switch (type & 0xff) {
1646 	case ND_NEIGHBOR_SOLICIT:
1647 		/*
1648 		 * New entry must have is_router flag cleared.
1649 		 */
1650 		if (is_new)					/* (6-7) */
1651 			ln_router = 0;
1652 		break;
1653 	case ND_REDIRECT:
1654 		/*
1655 		 * If the icmp is a redirect to a better router, always set the
1656 		 * is_router flag.  Otherwise, if the entry is newly created,
1657 		 * clear the flag.  [RFC 2461, sec 8.3]
1658 		 */
1659 		if (code == ND_REDIRECT_ROUTER)
1660 			ln_router = 1;
1661 		else {
1662 			if (is_new)				/* (6-7) */
1663 				ln_router = 0;
1664 		}
1665 		break;
1666 	case ND_ROUTER_SOLICIT:
1667 		/*
1668 		 * is_router flag must always be cleared.
1669 		 */
1670 		ln_router = 0;
1671 		break;
1672 	case ND_ROUTER_ADVERT:
1673 		/*
1674 		 * Mark an entry with lladdr as a router.
1675 		 */
1676 		if ((!is_new && (old_addr || new_addr)) ||	/* (2-5) */
1677 		    (is_new && new_addr)) {			/* (7) */
1678 			ln_router = 1;
1679 		}
1680 		break;
1681 	}
1682 
1683 	return (ln_router);
1684 }
1685 
1686 /*
1687  * Create neighbor cache entry and cache link-layer address,
1688  * on reception of inbound ND6 packets.  (RS/RA/NS/redirect)
1689  *
1690  * type - ICMP6 type
1691  * code - type dependent information
1692  *
1693  */
1694 void
1695 nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr,
1696     int lladdrlen, int type, int code)
1697 {
1698 	struct llentry *ln = NULL, *ln_tmp;
1699 	int is_newentry;
1700 	int do_update;
1701 	int olladdr;
1702 	int llchange;
1703 	int flags;
1704 	uint16_t router = 0;
1705 	struct sockaddr_in6 sin6;
1706 	struct mbuf *chain = NULL;
1707 
1708 	IF_AFDATA_UNLOCK_ASSERT(ifp);
1709 
1710 	KASSERT(ifp != NULL, ("%s: ifp == NULL", __func__));
1711 	KASSERT(from != NULL, ("%s: from == NULL", __func__));
1712 
1713 	/* nothing must be updated for unspecified address */
1714 	if (IN6_IS_ADDR_UNSPECIFIED(from))
1715 		return;
1716 
1717 	/*
1718 	 * Validation about ifp->if_addrlen and lladdrlen must be done in
1719 	 * the caller.
1720 	 *
1721 	 * XXX If the link does not have link-layer adderss, what should
1722 	 * we do? (ifp->if_addrlen == 0)
1723 	 * Spec says nothing in sections for RA, RS and NA.  There's small
1724 	 * description on it in NS section (RFC 2461 7.2.3).
1725 	 */
1726 	flags = lladdr ? LLE_EXCLUSIVE : 0;
1727 	IF_AFDATA_RLOCK(ifp);
1728 	ln = nd6_lookup(from, flags, ifp);
1729 	IF_AFDATA_RUNLOCK(ifp);
1730 	is_newentry = 0;
1731 	if (ln == NULL) {
1732 		flags |= LLE_EXCLUSIVE;
1733 		ln = nd6_alloc(from, 0, ifp);
1734 		if (ln == NULL)
1735 			return;
1736 
1737 		/*
1738 		 * Since we already know all the data for the new entry,
1739 		 * fill it before insertion.
1740 		 */
1741 		if (lladdr != NULL) {
1742 			bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen);
1743 			ln->la_flags |= LLE_VALID;
1744 		}
1745 		IF_AFDATA_WLOCK(ifp);
1746 		LLE_WLOCK(ln);
1747 		/* Prefer any existing lle over newly-created one */
1748 		ln_tmp = nd6_lookup(from, LLE_EXCLUSIVE, ifp);
1749 		if (ln_tmp == NULL)
1750 			lltable_link_entry(LLTABLE6(ifp), ln);
1751 		IF_AFDATA_WUNLOCK(ifp);
1752 		if (ln_tmp == NULL) {
1753 			/* No existing lle, mark as new entry (6,7) */
1754 			is_newentry = 1;
1755 			nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
1756 			if (lladdr != NULL)	/* (7) */
1757 				EVENTHANDLER_INVOKE(lle_event, ln,
1758 				    LLENTRY_RESOLVED);
1759 		} else {
1760 			lltable_free_entry(LLTABLE6(ifp), ln);
1761 			ln = ln_tmp;
1762 			ln_tmp = NULL;
1763 		}
1764 	}
1765 	/* do nothing if static ndp is set */
1766 	if ((ln->la_flags & LLE_STATIC)) {
1767 		if (flags & LLE_EXCLUSIVE)
1768 			LLE_WUNLOCK(ln);
1769 		else
1770 			LLE_RUNLOCK(ln);
1771 		return;
1772 	}
1773 
1774 	olladdr = (ln->la_flags & LLE_VALID) ? 1 : 0;
1775 	if (olladdr && lladdr) {
1776 		llchange = bcmp(lladdr, &ln->ll_addr,
1777 		    ifp->if_addrlen);
1778 	} else if (!olladdr && lladdr)
1779 		llchange = 1;
1780 	else
1781 		llchange = 0;
1782 
1783 	/*
1784 	 * newentry olladdr  lladdr  llchange	(*=record)
1785 	 *	0	n	n	--	(1)
1786 	 *	0	y	n	--	(2)
1787 	 *	0	n	y	y	(3) * STALE
1788 	 *	0	y	y	n	(4) *
1789 	 *	0	y	y	y	(5) * STALE
1790 	 *	1	--	n	--	(6)   NOSTATE(= PASSIVE)
1791 	 *	1	--	y	--	(7) * STALE
1792 	 */
1793 
1794 	do_update = 0;
1795 	if (is_newentry == 0 && llchange != 0) {
1796 		do_update = 1;	/* (3,5) */
1797 
1798 		/*
1799 		 * Record source link-layer address
1800 		 * XXX is it dependent to ifp->if_type?
1801 		 */
1802 		bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen);
1803 		ln->la_flags |= LLE_VALID;
1804 		nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
1805 
1806 		EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
1807 
1808 		if (ln->la_hold != NULL)
1809 			nd6_grab_holdchain(ln, &chain, &sin6);
1810 	}
1811 
1812 	/* Calculates new router status */
1813 	router = nd6_is_router(type, code, is_newentry, olladdr,
1814 	    lladdr != NULL ? 1 : 0, ln->ln_router);
1815 
1816 	ln->ln_router = router;
1817 	/* Mark non-router redirects with special flag */
1818 	if ((type & 0xFF) == ND_REDIRECT && code != ND_REDIRECT_ROUTER)
1819 		ln->la_flags |= LLE_REDIRECT;
1820 
1821 	if (flags & LLE_EXCLUSIVE)
1822 		LLE_WUNLOCK(ln);
1823 	else
1824 		LLE_RUNLOCK(ln);
1825 
1826 	if (chain != NULL)
1827 		nd6_flush_holdchain(ifp, ifp, chain, &sin6);
1828 
1829 	/*
1830 	 * When the link-layer address of a router changes, select the
1831 	 * best router again.  In particular, when the neighbor entry is newly
1832 	 * created, it might affect the selection policy.
1833 	 * Question: can we restrict the first condition to the "is_newentry"
1834 	 * case?
1835 	 * XXX: when we hear an RA from a new router with the link-layer
1836 	 * address option, defrouter_select() is called twice, since
1837 	 * defrtrlist_update called the function as well.  However, I believe
1838 	 * we can compromise the overhead, since it only happens the first
1839 	 * time.
1840 	 * XXX: although defrouter_select() should not have a bad effect
1841 	 * for those are not autoconfigured hosts, we explicitly avoid such
1842 	 * cases for safety.
1843 	 */
1844 	if ((do_update || is_newentry) && router &&
1845 	    ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
1846 		/*
1847 		 * guaranteed recursion
1848 		 */
1849 		defrouter_select();
1850 	}
1851 }
1852 
1853 static void
1854 nd6_slowtimo(void *arg)
1855 {
1856 	CURVNET_SET((struct vnet *) arg);
1857 	struct nd_ifinfo *nd6if;
1858 	struct ifnet *ifp;
1859 
1860 	callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
1861 	    nd6_slowtimo, curvnet);
1862 	IFNET_RLOCK_NOSLEEP();
1863 	TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
1864 		if (ifp->if_afdata[AF_INET6] == NULL)
1865 			continue;
1866 		nd6if = ND_IFINFO(ifp);
1867 		if (nd6if->basereachable && /* already initialized */
1868 		    (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
1869 			/*
1870 			 * Since reachable time rarely changes by router
1871 			 * advertisements, we SHOULD insure that a new random
1872 			 * value gets recomputed at least once every few hours.
1873 			 * (RFC 2461, 6.3.4)
1874 			 */
1875 			nd6if->recalctm = V_nd6_recalc_reachtm_interval;
1876 			nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable);
1877 		}
1878 	}
1879 	IFNET_RUNLOCK_NOSLEEP();
1880 	CURVNET_RESTORE();
1881 }
1882 
1883 void
1884 nd6_grab_holdchain(struct llentry *ln, struct mbuf **chain,
1885     struct sockaddr_in6 *sin6)
1886 {
1887 
1888 	LLE_WLOCK_ASSERT(ln);
1889 
1890 	*chain = ln->la_hold;
1891 	ln->la_hold = NULL;
1892 	lltable_fill_sa_entry(ln, (struct sockaddr *)sin6);
1893 
1894 	if (ln->ln_state == ND6_LLINFO_STALE) {
1895 
1896 		/*
1897 		 * The first time we send a packet to a
1898 		 * neighbor whose entry is STALE, we have
1899 		 * to change the state to DELAY and a sets
1900 		 * a timer to expire in DELAY_FIRST_PROBE_TIME
1901 		 * seconds to ensure do neighbor unreachability
1902 		 * detection on expiration.
1903 		 * (RFC 2461 7.3.3)
1904 		 */
1905 		nd6_llinfo_setstate(ln, ND6_LLINFO_DELAY);
1906 	}
1907 }
1908 
1909 int
1910 nd6_output_ifp(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
1911     struct sockaddr_in6 *dst)
1912 {
1913 	int error;
1914 	int ip6len;
1915 	struct ip6_hdr *ip6;
1916 	struct m_tag *mtag;
1917 
1918 #ifdef MAC
1919 	mac_netinet6_nd6_send(ifp, m);
1920 #endif
1921 
1922 	/*
1923 	 * If called from nd6_ns_output() (NS), nd6_na_output() (NA),
1924 	 * icmp6_redirect_output() (REDIRECT) or from rip6_output() (RS, RA
1925 	 * as handled by rtsol and rtadvd), mbufs will be tagged for SeND
1926 	 * to be diverted to user space.  When re-injected into the kernel,
1927 	 * send_output() will directly dispatch them to the outgoing interface.
1928 	 */
1929 	if (send_sendso_input_hook != NULL) {
1930 		mtag = m_tag_find(m, PACKET_TAG_ND_OUTGOING, NULL);
1931 		if (mtag != NULL) {
1932 			ip6 = mtod(m, struct ip6_hdr *);
1933 			ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
1934 			/* Use the SEND socket */
1935 			error = send_sendso_input_hook(m, ifp, SND_OUT,
1936 			    ip6len);
1937 			/* -1 == no app on SEND socket */
1938 			if (error == 0 || error != -1)
1939 			    return (error);
1940 		}
1941 	}
1942 
1943 	m_clrprotoflags(m);	/* Avoid confusing lower layers. */
1944 	IP_PROBE(send, NULL, NULL, mtod(m, struct ip6_hdr *), ifp, NULL,
1945 	    mtod(m, struct ip6_hdr *));
1946 
1947 	if ((ifp->if_flags & IFF_LOOPBACK) == 0)
1948 		origifp = ifp;
1949 
1950 	error = (*ifp->if_output)(origifp, m, (struct sockaddr *)dst, NULL);
1951 	return (error);
1952 }
1953 
1954 /*
1955  * Do L2 address resolution for @sa_dst address. Stores found
1956  * address in @desten buffer. Copy of lle ln_flags can be also
1957  * saved in @pflags if @pflags is non-NULL.
1958  *
1959  * If destination LLE does not exists or lle state modification
1960  * is required, call "slow" version.
1961  *
1962  * Return values:
1963  * - 0 on success (address copied to buffer).
1964  * - EWOULDBLOCK (no local error, but address is still unresolved)
1965  * - other errors (alloc failure, etc)
1966  */
1967 int
1968 nd6_resolve(struct ifnet *ifp, int is_gw, struct mbuf *m,
1969     const struct sockaddr *sa_dst, u_char *desten, uint32_t *pflags)
1970 {
1971 	struct llentry *ln = NULL;
1972 	const struct sockaddr_in6 *dst6;
1973 
1974 	if (pflags != NULL)
1975 		*pflags = 0;
1976 
1977 	dst6 = (const struct sockaddr_in6 *)sa_dst;
1978 
1979 	/* discard the packet if IPv6 operation is disabled on the interface */
1980 	if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED)) {
1981 		m_freem(m);
1982 		return (ENETDOWN); /* better error? */
1983 	}
1984 
1985 	if (m != NULL && m->m_flags & M_MCAST) {
1986 		switch (ifp->if_type) {
1987 		case IFT_ETHER:
1988 		case IFT_FDDI:
1989 		case IFT_L2VLAN:
1990 		case IFT_IEEE80211:
1991 		case IFT_BRIDGE:
1992 		case IFT_ISO88025:
1993 			ETHER_MAP_IPV6_MULTICAST(&dst6->sin6_addr,
1994 						 desten);
1995 			return (0);
1996 		default:
1997 			m_freem(m);
1998 			return (EAFNOSUPPORT);
1999 		}
2000 	}
2001 
2002 	IF_AFDATA_RLOCK(ifp);
2003 	ln = nd6_lookup(&dst6->sin6_addr, 0, ifp);
2004 	IF_AFDATA_RUNLOCK(ifp);
2005 
2006 	/*
2007 	 * Perform fast path for the following cases:
2008 	 * 1) lle state is REACHABLE
2009 	 * 2) lle state is DELAY (NS message sent)
2010 	 *
2011 	 * Every other case involves lle modification, so we handle
2012 	 * them separately.
2013 	 */
2014 	if (ln == NULL || (ln->ln_state != ND6_LLINFO_REACHABLE &&
2015 	    ln->ln_state != ND6_LLINFO_DELAY)) {
2016 		/* Fall back to slow processing path */
2017 		if (ln != NULL)
2018 			LLE_RUNLOCK(ln);
2019 		return (nd6_resolve_slow(ifp, m, dst6, desten, pflags));
2020 	}
2021 
2022 
2023 	bcopy(&ln->ll_addr, desten, ifp->if_addrlen);
2024 	if (pflags != NULL)
2025 		*pflags = ln->la_flags;
2026 	LLE_RUNLOCK(ln);
2027 	return (0);
2028 }
2029 
2030 
2031 /*
2032  * Do L2 address resolution for @sa_dst address. Stores found
2033  * address in @desten buffer. Copy of lle ln_flags can be also
2034  * saved in @pflags if @pflags is non-NULL.
2035  *
2036  * Heavy version.
2037  * Function assume that destination LLE does not exist,
2038  * is invalid or stale, so LLE_EXCLUSIVE lock needs to be acquired.
2039  *
2040  * Set noinline to be dtrace-friendly
2041  */
2042 static __noinline int
2043 nd6_resolve_slow(struct ifnet *ifp, struct mbuf *m,
2044     const struct sockaddr_in6 *dst, u_char *desten, uint32_t *pflags)
2045 {
2046 	struct llentry *lle = NULL, *lle_tmp;
2047 	struct in6_addr *psrc, src;
2048 	int send_ns;
2049 
2050 	/*
2051 	 * Address resolution or Neighbor Unreachability Detection
2052 	 * for the next hop.
2053 	 * At this point, the destination of the packet must be a unicast
2054 	 * or an anycast address(i.e. not a multicast).
2055 	 */
2056 	if (lle == NULL) {
2057 		IF_AFDATA_RLOCK(ifp);
2058 		lle = nd6_lookup(&dst->sin6_addr, LLE_EXCLUSIVE, ifp);
2059 		IF_AFDATA_RUNLOCK(ifp);
2060 		if ((lle == NULL) && nd6_is_addr_neighbor(dst, ifp))  {
2061 			/*
2062 			 * Since nd6_is_addr_neighbor() internally calls nd6_lookup(),
2063 			 * the condition below is not very efficient.  But we believe
2064 			 * it is tolerable, because this should be a rare case.
2065 			 */
2066 			lle = nd6_alloc(&dst->sin6_addr, 0, ifp);
2067 			if (lle == NULL) {
2068 				char ip6buf[INET6_ADDRSTRLEN];
2069 				log(LOG_DEBUG,
2070 				    "nd6_output: can't allocate llinfo for %s "
2071 				    "(ln=%p)\n",
2072 				    ip6_sprintf(ip6buf, &dst->sin6_addr), lle);
2073 				m_freem(m);
2074 				return (ENOBUFS);
2075 			}
2076 
2077 			IF_AFDATA_WLOCK(ifp);
2078 			LLE_WLOCK(lle);
2079 			/* Prefer any existing entry over newly-created one */
2080 			lle_tmp = nd6_lookup(&dst->sin6_addr, LLE_EXCLUSIVE, ifp);
2081 			if (lle_tmp == NULL)
2082 				lltable_link_entry(LLTABLE6(ifp), lle);
2083 			IF_AFDATA_WUNLOCK(ifp);
2084 			if (lle_tmp != NULL) {
2085 				lltable_free_entry(LLTABLE6(ifp), lle);
2086 				lle = lle_tmp;
2087 				lle_tmp = NULL;
2088 			}
2089 		}
2090 	}
2091 	if (lle == NULL) {
2092 		if (!(ND_IFINFO(ifp)->flags & ND6_IFF_PERFORMNUD)) {
2093 			m_freem(m);
2094 			return (ENOBUFS);
2095 		}
2096 
2097 		if (m != NULL)
2098 			m_freem(m);
2099 		return (ENOBUFS);
2100 	}
2101 
2102 	LLE_WLOCK_ASSERT(lle);
2103 
2104 	/*
2105 	 * The first time we send a packet to a neighbor whose entry is
2106 	 * STALE, we have to change the state to DELAY and a sets a timer to
2107 	 * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do
2108 	 * neighbor unreachability detection on expiration.
2109 	 * (RFC 2461 7.3.3)
2110 	 */
2111 	if (lle->ln_state == ND6_LLINFO_STALE)
2112 		nd6_llinfo_setstate(lle, ND6_LLINFO_DELAY);
2113 
2114 	/*
2115 	 * If the neighbor cache entry has a state other than INCOMPLETE
2116 	 * (i.e. its link-layer address is already resolved), just
2117 	 * send the packet.
2118 	 */
2119 	if (lle->ln_state > ND6_LLINFO_INCOMPLETE) {
2120 		bcopy(&lle->ll_addr, desten, ifp->if_addrlen);
2121 		if (pflags != NULL)
2122 			*pflags = lle->la_flags;
2123 		LLE_WUNLOCK(lle);
2124 		return (0);
2125 	}
2126 
2127 	/*
2128 	 * There is a neighbor cache entry, but no ethernet address
2129 	 * response yet.  Append this latest packet to the end of the
2130 	 * packet queue in the mbuf, unless the number of the packet
2131 	 * does not exceed nd6_maxqueuelen.  When it exceeds nd6_maxqueuelen,
2132 	 * the oldest packet in the queue will be removed.
2133 	 */
2134 
2135 	if (lle->la_hold != NULL) {
2136 		struct mbuf *m_hold;
2137 		int i;
2138 
2139 		i = 0;
2140 		for (m_hold = lle->la_hold; m_hold; m_hold = m_hold->m_nextpkt){
2141 			i++;
2142 			if (m_hold->m_nextpkt == NULL) {
2143 				m_hold->m_nextpkt = m;
2144 				break;
2145 			}
2146 		}
2147 		while (i >= V_nd6_maxqueuelen) {
2148 			m_hold = lle->la_hold;
2149 			lle->la_hold = lle->la_hold->m_nextpkt;
2150 			m_freem(m_hold);
2151 			i--;
2152 		}
2153 	} else {
2154 		lle->la_hold = m;
2155 	}
2156 
2157 	/*
2158 	 * If there has been no NS for the neighbor after entering the
2159 	 * INCOMPLETE state, send the first solicitation.
2160 	 * Note that for newly-created lle la_asked will be 0,
2161 	 * so we will transition from ND6_LLINFO_NOSTATE to
2162 	 * ND6_LLINFO_INCOMPLETE state here.
2163 	 */
2164 	psrc = NULL;
2165 	send_ns = 0;
2166 	if (lle->la_asked == 0) {
2167 		lle->la_asked++;
2168 		send_ns = 1;
2169 		psrc = nd6_llinfo_get_holdsrc(lle, &src);
2170 
2171 		nd6_llinfo_setstate(lle, ND6_LLINFO_INCOMPLETE);
2172 	}
2173 	LLE_WUNLOCK(lle);
2174 	if (send_ns != 0)
2175 		nd6_ns_output(ifp, psrc, NULL, &dst->sin6_addr, NULL);
2176 
2177 	return (EWOULDBLOCK);
2178 }
2179 
2180 
2181 int
2182 nd6_flush_holdchain(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *chain,
2183     struct sockaddr_in6 *dst)
2184 {
2185 	struct mbuf *m, *m_head;
2186 	struct ifnet *outifp;
2187 	int error = 0;
2188 
2189 	m_head = chain;
2190 	if ((ifp->if_flags & IFF_LOOPBACK) != 0)
2191 		outifp = origifp;
2192 	else
2193 		outifp = ifp;
2194 
2195 	while (m_head) {
2196 		m = m_head;
2197 		m_head = m_head->m_nextpkt;
2198 		error = nd6_output_ifp(ifp, origifp, m, dst);
2199 	}
2200 
2201 	/*
2202 	 * XXX
2203 	 * note that intermediate errors are blindly ignored
2204 	 */
2205 	return (error);
2206 }
2207 
2208 static int
2209 nd6_need_cache(struct ifnet *ifp)
2210 {
2211 	/*
2212 	 * XXX: we currently do not make neighbor cache on any interface
2213 	 * other than ARCnet, Ethernet, FDDI and GIF.
2214 	 *
2215 	 * RFC2893 says:
2216 	 * - unidirectional tunnels needs no ND
2217 	 */
2218 	switch (ifp->if_type) {
2219 	case IFT_ARCNET:
2220 	case IFT_ETHER:
2221 	case IFT_FDDI:
2222 	case IFT_IEEE1394:
2223 	case IFT_L2VLAN:
2224 	case IFT_IEEE80211:
2225 	case IFT_INFINIBAND:
2226 	case IFT_BRIDGE:
2227 	case IFT_PROPVIRTUAL:
2228 		return (1);
2229 	default:
2230 		return (0);
2231 	}
2232 }
2233 
2234 /*
2235  * Add pernament ND6 link-layer record for given
2236  * interface address.
2237  *
2238  * Very similar to IPv4 arp_ifinit(), but:
2239  * 1) IPv6 DAD is performed in different place
2240  * 2) It is called by IPv6 protocol stack in contrast to
2241  * arp_ifinit() which is typically called in SIOCSIFADDR
2242  * driver ioctl handler.
2243  *
2244  */
2245 int
2246 nd6_add_ifa_lle(struct in6_ifaddr *ia)
2247 {
2248 	struct ifnet *ifp;
2249 	struct llentry *ln, *ln_tmp;
2250 	struct sockaddr *dst;
2251 
2252 	ifp = ia->ia_ifa.ifa_ifp;
2253 	if (nd6_need_cache(ifp) == 0)
2254 		return (0);
2255 
2256 	ia->ia_ifa.ifa_rtrequest = nd6_rtrequest;
2257 	dst = (struct sockaddr *)&ia->ia_addr;
2258 	ln = lltable_alloc_entry(LLTABLE6(ifp), LLE_IFADDR, dst);
2259 	if (ln == NULL)
2260 		return (ENOBUFS);
2261 
2262 	IF_AFDATA_WLOCK(ifp);
2263 	LLE_WLOCK(ln);
2264 	/* Unlink any entry if exists */
2265 	ln_tmp = lla_lookup(LLTABLE6(ifp), LLE_EXCLUSIVE, dst);
2266 	if (ln_tmp != NULL)
2267 		lltable_unlink_entry(LLTABLE6(ifp), ln_tmp);
2268 	lltable_link_entry(LLTABLE6(ifp), ln);
2269 	IF_AFDATA_WUNLOCK(ifp);
2270 
2271 	if (ln_tmp != NULL)
2272 		EVENTHANDLER_INVOKE(lle_event, ln_tmp, LLENTRY_EXPIRED);
2273 	EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
2274 
2275 	LLE_WUNLOCK(ln);
2276 	if (ln_tmp != NULL)
2277 		llentry_free(ln_tmp);
2278 
2279 	return (0);
2280 }
2281 
2282 /*
2283  * Removes either all lle entries for given @ia, or lle
2284  * corresponding to @ia address.
2285  */
2286 void
2287 nd6_rem_ifa_lle(struct in6_ifaddr *ia, int all)
2288 {
2289 	struct sockaddr_in6 mask, addr;
2290 	struct sockaddr *saddr, *smask;
2291 	struct ifnet *ifp;
2292 
2293 	ifp = ia->ia_ifa.ifa_ifp;
2294 	memcpy(&addr, &ia->ia_addr, sizeof(ia->ia_addr));
2295 	memcpy(&mask, &ia->ia_prefixmask, sizeof(ia->ia_prefixmask));
2296 	saddr = (struct sockaddr *)&addr;
2297 	smask = (struct sockaddr *)&mask;
2298 
2299 	if (all != 0)
2300 		lltable_prefix_free(AF_INET6, saddr, smask, LLE_STATIC);
2301 	else
2302 		lltable_delete_addr(LLTABLE6(ifp), LLE_IFADDR, saddr);
2303 }
2304 
2305 static void
2306 clear_llinfo_pqueue(struct llentry *ln)
2307 {
2308 	struct mbuf *m_hold, *m_hold_next;
2309 
2310 	for (m_hold = ln->la_hold; m_hold; m_hold = m_hold_next) {
2311 		m_hold_next = m_hold->m_nextpkt;
2312 		m_freem(m_hold);
2313 	}
2314 
2315 	ln->la_hold = NULL;
2316 	return;
2317 }
2318 
2319 static int nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS);
2320 static int nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS);
2321 #ifdef SYSCTL_DECL
2322 SYSCTL_DECL(_net_inet6_icmp6);
2323 #endif
2324 SYSCTL_NODE(_net_inet6_icmp6, ICMPV6CTL_ND6_DRLIST, nd6_drlist,
2325 	CTLFLAG_RD, nd6_sysctl_drlist, "");
2326 SYSCTL_NODE(_net_inet6_icmp6, ICMPV6CTL_ND6_PRLIST, nd6_prlist,
2327 	CTLFLAG_RD, nd6_sysctl_prlist, "");
2328 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_MAXQLEN, nd6_maxqueuelen,
2329 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_maxqueuelen), 1, "");
2330 SYSCTL_INT(_net_inet6_icmp6, OID_AUTO, nd6_gctimer,
2331 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_gctimer), (60 * 60 * 24), "");
2332 
2333 static int
2334 nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS)
2335 {
2336 	struct in6_defrouter d;
2337 	struct nd_defrouter *dr;
2338 	int error;
2339 
2340 	if (req->newptr)
2341 		return (EPERM);
2342 
2343 	bzero(&d, sizeof(d));
2344 	d.rtaddr.sin6_family = AF_INET6;
2345 	d.rtaddr.sin6_len = sizeof(d.rtaddr);
2346 
2347 	/*
2348 	 * XXX locking
2349 	 */
2350 	TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
2351 		d.rtaddr.sin6_addr = dr->rtaddr;
2352 		error = sa6_recoverscope(&d.rtaddr);
2353 		if (error != 0)
2354 			return (error);
2355 		d.flags = dr->flags;
2356 		d.rtlifetime = dr->rtlifetime;
2357 		d.expire = dr->expire + (time_second - time_uptime);
2358 		d.if_index = dr->ifp->if_index;
2359 		error = SYSCTL_OUT(req, &d, sizeof(d));
2360 		if (error != 0)
2361 			return (error);
2362 	}
2363 	return (0);
2364 }
2365 
2366 static int
2367 nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS)
2368 {
2369 	struct in6_prefix p;
2370 	struct sockaddr_in6 s6;
2371 	struct nd_prefix *pr;
2372 	struct nd_pfxrouter *pfr;
2373 	time_t maxexpire;
2374 	int error;
2375 	char ip6buf[INET6_ADDRSTRLEN];
2376 
2377 	if (req->newptr)
2378 		return (EPERM);
2379 
2380 	bzero(&p, sizeof(p));
2381 	p.origin = PR_ORIG_RA;
2382 	bzero(&s6, sizeof(s6));
2383 	s6.sin6_family = AF_INET6;
2384 	s6.sin6_len = sizeof(s6);
2385 
2386 	/*
2387 	 * XXX locking
2388 	 */
2389 	LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
2390 		p.prefix = pr->ndpr_prefix;
2391 		if (sa6_recoverscope(&p.prefix)) {
2392 			log(LOG_ERR, "scope error in prefix list (%s)\n",
2393 			    ip6_sprintf(ip6buf, &p.prefix.sin6_addr));
2394 			/* XXX: press on... */
2395 		}
2396 		p.raflags = pr->ndpr_raf;
2397 		p.prefixlen = pr->ndpr_plen;
2398 		p.vltime = pr->ndpr_vltime;
2399 		p.pltime = pr->ndpr_pltime;
2400 		p.if_index = pr->ndpr_ifp->if_index;
2401 		if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME)
2402 			p.expire = 0;
2403 		else {
2404 			/* XXX: we assume time_t is signed. */
2405 			maxexpire = (-1) &
2406 			    ~((time_t)1 << ((sizeof(maxexpire) * 8) - 1));
2407 			if (pr->ndpr_vltime < maxexpire - pr->ndpr_lastupdate)
2408 				p.expire = pr->ndpr_lastupdate +
2409 				    pr->ndpr_vltime +
2410 				    (time_second - time_uptime);
2411 			else
2412 				p.expire = maxexpire;
2413 		}
2414 		p.refcnt = pr->ndpr_refcnt;
2415 		p.flags = pr->ndpr_stateflags;
2416 		p.advrtrs = 0;
2417 		LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry)
2418 			p.advrtrs++;
2419 		error = SYSCTL_OUT(req, &p, sizeof(p));
2420 		if (error != 0)
2421 			return (error);
2422 		LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) {
2423 			s6.sin6_addr = pfr->router->rtaddr;
2424 			if (sa6_recoverscope(&s6))
2425 				log(LOG_ERR,
2426 				    "scope error in prefix list (%s)\n",
2427 				    ip6_sprintf(ip6buf, &pfr->router->rtaddr));
2428 			error = SYSCTL_OUT(req, &s6, sizeof(s6));
2429 			if (error != 0)
2430 				return (error);
2431 		}
2432 	}
2433 	return (0);
2434 }
2435