xref: /freebsd/sys/netinet6/nd6.c (revision 5d06879adb95ac922703072a28fc11048d809a4b)
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(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 struct llentry *nd6_free(struct llentry *, int);
135 static void nd6_llinfo_timer(void *);
136 static void clear_llinfo_pqueue(struct llentry *);
137 static void nd6_rtrequest(int, struct rtentry *, struct rt_addrinfo *);
138 static int nd6_output_lle(struct ifnet *, struct ifnet *, struct mbuf *,
139 	struct sockaddr_in6 *);
140 static int nd6_output_ifp(struct ifnet *, struct ifnet *, struct mbuf *,
141     struct sockaddr_in6 *);
142 
143 static VNET_DEFINE(struct callout, nd6_slowtimo_ch);
144 #define	V_nd6_slowtimo_ch		VNET(nd6_slowtimo_ch)
145 
146 VNET_DEFINE(struct callout, nd6_timer_ch);
147 
148 static void
149 nd6_lle_event(void *arg __unused, struct llentry *lle, int evt)
150 {
151 	struct rt_addrinfo rtinfo;
152 	struct sockaddr_in6 dst;
153 	struct sockaddr_dl gw;
154 	struct ifnet *ifp;
155 	int type;
156 
157 	LLE_WLOCK_ASSERT(lle);
158 
159 	if (lltable_get_af(lle->lle_tbl) != AF_INET6)
160 		return;
161 
162 	switch (evt) {
163 	case LLENTRY_RESOLVED:
164 		type = RTM_ADD;
165 		KASSERT(lle->la_flags & LLE_VALID,
166 		    ("%s: %p resolved but not valid?", __func__, lle));
167 		break;
168 	case LLENTRY_EXPIRED:
169 		type = RTM_DELETE;
170 		break;
171 	default:
172 		return;
173 	}
174 
175 	ifp = lltable_get_ifp(lle->lle_tbl);
176 
177 	bzero(&dst, sizeof(dst));
178 	bzero(&gw, sizeof(gw));
179 	bzero(&rtinfo, sizeof(rtinfo));
180 	lltable_fill_sa_entry(lle, (struct sockaddr *)&dst);
181 	dst.sin6_scope_id = in6_getscopezone(ifp,
182 	    in6_addrscope(&dst.sin6_addr));
183 	gw.sdl_len = sizeof(struct sockaddr_dl);
184 	gw.sdl_family = AF_LINK;
185 	gw.sdl_alen = ifp->if_addrlen;
186 	gw.sdl_index = ifp->if_index;
187 	gw.sdl_type = ifp->if_type;
188 	if (evt == LLENTRY_RESOLVED)
189 		bcopy(&lle->ll_addr, gw.sdl_data, ifp->if_addrlen);
190 	rtinfo.rti_info[RTAX_DST] = (struct sockaddr *)&dst;
191 	rtinfo.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&gw;
192 	rtinfo.rti_addrs = RTA_DST | RTA_GATEWAY;
193 	rt_missmsg_fib(type, &rtinfo, RTF_HOST | RTF_LLDATA | (
194 	    type == RTM_ADD ? RTF_UP: 0), 0, RT_DEFAULT_FIB);
195 }
196 
197 void
198 nd6_init(void)
199 {
200 
201 	LIST_INIT(&V_nd_prefix);
202 
203 	/* initialization of the default router list */
204 	TAILQ_INIT(&V_nd_defrouter);
205 
206 	/* start timer */
207 	callout_init(&V_nd6_slowtimo_ch, 0);
208 	callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
209 	    nd6_slowtimo, curvnet);
210 
211 	nd6_dad_init();
212 	if (IS_DEFAULT_VNET(curvnet))
213 		lle_event_eh = EVENTHANDLER_REGISTER(lle_event, nd6_lle_event,
214 		    NULL, EVENTHANDLER_PRI_ANY);
215 }
216 
217 #ifdef VIMAGE
218 void
219 nd6_destroy()
220 {
221 
222 	callout_drain(&V_nd6_slowtimo_ch);
223 	callout_drain(&V_nd6_timer_ch);
224 	if (IS_DEFAULT_VNET(curvnet))
225 		EVENTHANDLER_DEREGISTER(lle_event, lle_event_eh);
226 }
227 #endif
228 
229 struct nd_ifinfo *
230 nd6_ifattach(struct ifnet *ifp)
231 {
232 	struct nd_ifinfo *nd;
233 
234 	nd = (struct nd_ifinfo *)malloc(sizeof(*nd), M_IP6NDP, M_WAITOK|M_ZERO);
235 	nd->initialized = 1;
236 
237 	nd->chlim = IPV6_DEFHLIM;
238 	nd->basereachable = REACHABLE_TIME;
239 	nd->reachable = ND_COMPUTE_RTIME(nd->basereachable);
240 	nd->retrans = RETRANS_TIMER;
241 
242 	nd->flags = ND6_IFF_PERFORMNUD;
243 
244 	/* A loopback interface always has ND6_IFF_AUTO_LINKLOCAL.
245 	 * XXXHRS: Clear ND6_IFF_AUTO_LINKLOCAL on an IFT_BRIDGE interface by
246 	 * default regardless of the V_ip6_auto_linklocal configuration to
247 	 * give a reasonable default behavior.
248 	 */
249 	if ((V_ip6_auto_linklocal && ifp->if_type != IFT_BRIDGE) ||
250 	    (ifp->if_flags & IFF_LOOPBACK))
251 		nd->flags |= ND6_IFF_AUTO_LINKLOCAL;
252 	/*
253 	 * A loopback interface does not need to accept RTADV.
254 	 * XXXHRS: Clear ND6_IFF_ACCEPT_RTADV on an IFT_BRIDGE interface by
255 	 * default regardless of the V_ip6_accept_rtadv configuration to
256 	 * prevent the interface from accepting RA messages arrived
257 	 * on one of the member interfaces with ND6_IFF_ACCEPT_RTADV.
258 	 */
259 	if (V_ip6_accept_rtadv &&
260 	    !(ifp->if_flags & IFF_LOOPBACK) &&
261 	    (ifp->if_type != IFT_BRIDGE))
262 			nd->flags |= ND6_IFF_ACCEPT_RTADV;
263 	if (V_ip6_no_radr && !(ifp->if_flags & IFF_LOOPBACK))
264 		nd->flags |= ND6_IFF_NO_RADR;
265 
266 	/* XXX: we cannot call nd6_setmtu since ifp is not fully initialized */
267 	nd6_setmtu0(ifp, nd);
268 
269 	return nd;
270 }
271 
272 void
273 nd6_ifdetach(struct nd_ifinfo *nd)
274 {
275 
276 	free(nd, M_IP6NDP);
277 }
278 
279 /*
280  * Reset ND level link MTU. This function is called when the physical MTU
281  * changes, which means we might have to adjust the ND level MTU.
282  */
283 void
284 nd6_setmtu(struct ifnet *ifp)
285 {
286 
287 	nd6_setmtu0(ifp, ND_IFINFO(ifp));
288 }
289 
290 /* XXX todo: do not maintain copy of ifp->if_mtu in ndi->maxmtu */
291 void
292 nd6_setmtu0(struct ifnet *ifp, struct nd_ifinfo *ndi)
293 {
294 	u_int32_t omaxmtu;
295 
296 	omaxmtu = ndi->maxmtu;
297 
298 	switch (ifp->if_type) {
299 	case IFT_ARCNET:
300 		ndi->maxmtu = MIN(ARC_PHDS_MAXMTU, ifp->if_mtu); /* RFC2497 */
301 		break;
302 	case IFT_FDDI:
303 		ndi->maxmtu = MIN(FDDIIPMTU, ifp->if_mtu); /* RFC2467 */
304 		break;
305 	case IFT_ISO88025:
306 		 ndi->maxmtu = MIN(ISO88025_MAX_MTU, ifp->if_mtu);
307 		 break;
308 	default:
309 		ndi->maxmtu = ifp->if_mtu;
310 		break;
311 	}
312 
313 	/*
314 	 * Decreasing the interface MTU under IPV6 minimum MTU may cause
315 	 * undesirable situation.  We thus notify the operator of the change
316 	 * explicitly.  The check for omaxmtu is necessary to restrict the
317 	 * log to the case of changing the MTU, not initializing it.
318 	 */
319 	if (omaxmtu >= IPV6_MMTU && ndi->maxmtu < IPV6_MMTU) {
320 		log(LOG_NOTICE, "nd6_setmtu0: "
321 		    "new link MTU on %s (%lu) is too small for IPv6\n",
322 		    if_name(ifp), (unsigned long)ndi->maxmtu);
323 	}
324 
325 	if (ndi->maxmtu > V_in6_maxmtu)
326 		in6_setmaxmtu(); /* check all interfaces just in case */
327 
328 }
329 
330 void
331 nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts)
332 {
333 
334 	bzero(ndopts, sizeof(*ndopts));
335 	ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
336 	ndopts->nd_opts_last
337 		= (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len);
338 
339 	if (icmp6len == 0) {
340 		ndopts->nd_opts_done = 1;
341 		ndopts->nd_opts_search = NULL;
342 	}
343 }
344 
345 /*
346  * Take one ND option.
347  */
348 struct nd_opt_hdr *
349 nd6_option(union nd_opts *ndopts)
350 {
351 	struct nd_opt_hdr *nd_opt;
352 	int olen;
353 
354 	KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__));
355 	KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts",
356 	    __func__));
357 	if (ndopts->nd_opts_search == NULL)
358 		return NULL;
359 	if (ndopts->nd_opts_done)
360 		return NULL;
361 
362 	nd_opt = ndopts->nd_opts_search;
363 
364 	/* make sure nd_opt_len is inside the buffer */
365 	if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) {
366 		bzero(ndopts, sizeof(*ndopts));
367 		return NULL;
368 	}
369 
370 	olen = nd_opt->nd_opt_len << 3;
371 	if (olen == 0) {
372 		/*
373 		 * Message validation requires that all included
374 		 * options have a length that is greater than zero.
375 		 */
376 		bzero(ndopts, sizeof(*ndopts));
377 		return NULL;
378 	}
379 
380 	ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen);
381 	if (ndopts->nd_opts_search > ndopts->nd_opts_last) {
382 		/* option overruns the end of buffer, invalid */
383 		bzero(ndopts, sizeof(*ndopts));
384 		return NULL;
385 	} else if (ndopts->nd_opts_search == ndopts->nd_opts_last) {
386 		/* reached the end of options chain */
387 		ndopts->nd_opts_done = 1;
388 		ndopts->nd_opts_search = NULL;
389 	}
390 	return nd_opt;
391 }
392 
393 /*
394  * Parse multiple ND options.
395  * This function is much easier to use, for ND routines that do not need
396  * multiple options of the same type.
397  */
398 int
399 nd6_options(union nd_opts *ndopts)
400 {
401 	struct nd_opt_hdr *nd_opt;
402 	int i = 0;
403 
404 	KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__));
405 	KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts",
406 	    __func__));
407 	if (ndopts->nd_opts_search == NULL)
408 		return 0;
409 
410 	while (1) {
411 		nd_opt = nd6_option(ndopts);
412 		if (nd_opt == NULL && ndopts->nd_opts_last == NULL) {
413 			/*
414 			 * Message validation requires that all included
415 			 * options have a length that is greater than zero.
416 			 */
417 			ICMP6STAT_INC(icp6s_nd_badopt);
418 			bzero(ndopts, sizeof(*ndopts));
419 			return -1;
420 		}
421 
422 		if (nd_opt == NULL)
423 			goto skip1;
424 
425 		switch (nd_opt->nd_opt_type) {
426 		case ND_OPT_SOURCE_LINKADDR:
427 		case ND_OPT_TARGET_LINKADDR:
428 		case ND_OPT_MTU:
429 		case ND_OPT_REDIRECTED_HEADER:
430 		case ND_OPT_NONCE:
431 			if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
432 				nd6log((LOG_INFO,
433 				    "duplicated ND6 option found (type=%d)\n",
434 				    nd_opt->nd_opt_type));
435 				/* XXX bark? */
436 			} else {
437 				ndopts->nd_opt_array[nd_opt->nd_opt_type]
438 					= nd_opt;
439 			}
440 			break;
441 		case ND_OPT_PREFIX_INFORMATION:
442 			if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
443 				ndopts->nd_opt_array[nd_opt->nd_opt_type]
444 					= nd_opt;
445 			}
446 			ndopts->nd_opts_pi_end =
447 				(struct nd_opt_prefix_info *)nd_opt;
448 			break;
449 		/* What about ND_OPT_ROUTE_INFO? RFC 4191 */
450 		case ND_OPT_RDNSS:	/* RFC 6106 */
451 		case ND_OPT_DNSSL:	/* RFC 6106 */
452 			/*
453 			 * Silently ignore options we know and do not care about
454 			 * in the kernel.
455 			 */
456 			break;
457 		default:
458 			/*
459 			 * Unknown options must be silently ignored,
460 			 * to accomodate future extension to the protocol.
461 			 */
462 			nd6log((LOG_DEBUG,
463 			    "nd6_options: unsupported option %d - "
464 			    "option ignored\n", nd_opt->nd_opt_type));
465 		}
466 
467 skip1:
468 		i++;
469 		if (i > V_nd6_maxndopt) {
470 			ICMP6STAT_INC(icp6s_nd_toomanyopt);
471 			nd6log((LOG_INFO, "too many loop in nd opt\n"));
472 			break;
473 		}
474 
475 		if (ndopts->nd_opts_done)
476 			break;
477 	}
478 
479 	return 0;
480 }
481 
482 /*
483  * ND6 timer routine to handle ND6 entries
484  */
485 void
486 nd6_llinfo_settimer_locked(struct llentry *ln, long tick)
487 {
488 	int canceled;
489 
490 	LLE_WLOCK_ASSERT(ln);
491 
492 	if (tick < 0) {
493 		ln->la_expire = 0;
494 		ln->ln_ntick = 0;
495 		canceled = callout_stop(&ln->lle_timer);
496 	} else {
497 		ln->la_expire = time_uptime + tick / hz;
498 		LLE_ADDREF(ln);
499 		if (tick > INT_MAX) {
500 			ln->ln_ntick = tick - INT_MAX;
501 			canceled = callout_reset(&ln->lle_timer, INT_MAX,
502 			    nd6_llinfo_timer, ln);
503 		} else {
504 			ln->ln_ntick = 0;
505 			canceled = callout_reset(&ln->lle_timer, tick,
506 			    nd6_llinfo_timer, ln);
507 		}
508 	}
509 	if (canceled)
510 		LLE_REMREF(ln);
511 }
512 
513 /*
514 * Gets source address of the first packet in hold queue
515 * and stores it in @src.
516 * Returns pointer to @src (if hold queue is not empty) or NULL.
517 *
518 */
519 static struct in6_addr *
520 nd6_llinfo_get_holdsrc(struct llentry *ln, struct in6_addr *src)
521 {
522 	struct ip6_hdr hdr;
523 	struct mbuf *m;
524 
525 	if (ln->la_hold == NULL)
526 		return (NULL);
527 
528 	/*
529 	 * assume every packet in la_hold has the same IP header
530 	 */
531 	m = ln->la_hold;
532 	if (sizeof(hdr) < m->m_len)
533 		return (NULL);
534 
535 	m_copydata(m, 0, sizeof(hdr), (caddr_t)&hdr);
536 	*src = hdr.ip6_src;
537 
538 	return (src);
539 }
540 
541 void
542 nd6_llinfo_settimer(struct llentry *ln, long tick)
543 {
544 
545 	LLE_WLOCK(ln);
546 	nd6_llinfo_settimer_locked(ln, tick);
547 	LLE_WUNLOCK(ln);
548 }
549 
550 static void
551 nd6_llinfo_timer(void *arg)
552 {
553 	struct llentry *ln;
554 	struct in6_addr *dst, *pdst, *psrc, src;
555 	struct ifnet *ifp;
556 	struct nd_ifinfo *ndi = NULL;
557 	int send_ns;
558 
559 	KASSERT(arg != NULL, ("%s: arg NULL", __func__));
560 	ln = (struct llentry *)arg;
561 	LLE_WLOCK(ln);
562 	if (callout_pending(&ln->lle_timer)) {
563 		/*
564 		 * Here we are a bit odd here in the treatment of
565 		 * active/pending. If the pending bit is set, it got
566 		 * rescheduled before I ran. The active
567 		 * bit we ignore, since if it was stopped
568 		 * in ll_tablefree() and was currently running
569 		 * it would have return 0 so the code would
570 		 * not have deleted it since the callout could
571 		 * not be stopped so we want to go through
572 		 * with the delete here now. If the callout
573 		 * was restarted, the pending bit will be back on and
574 		 * we just want to bail since the callout_reset would
575 		 * return 1 and our reference would have been removed
576 		 * by nd6_llinfo_settimer_locked above since canceled
577 		 * would have been 1.
578 		 */
579 		LLE_WUNLOCK(ln);
580 		return;
581 	}
582 	ifp = ln->lle_tbl->llt_ifp;
583 	CURVNET_SET(ifp->if_vnet);
584 	ndi = ND_IFINFO(ifp);
585 	send_ns = 0;
586 	dst = &ln->r_l3addr.addr6;
587 	pdst = dst;
588 
589 	if (ln->ln_ntick > 0) {
590 		if (ln->ln_ntick > INT_MAX) {
591 			ln->ln_ntick -= INT_MAX;
592 			nd6_llinfo_settimer_locked(ln, INT_MAX);
593 		} else {
594 			ln->ln_ntick = 0;
595 			nd6_llinfo_settimer_locked(ln, ln->ln_ntick);
596 		}
597 		goto done;
598 	}
599 
600 	if (ln->la_flags & LLE_STATIC) {
601 		goto done;
602 	}
603 
604 	if (ln->la_flags & LLE_DELETED) {
605 		(void)nd6_free(ln, 0);
606 		ln = NULL;
607 		goto done;
608 	}
609 
610 	switch (ln->ln_state) {
611 	case ND6_LLINFO_INCOMPLETE:
612 		if (ln->la_asked < V_nd6_mmaxtries) {
613 			ln->la_asked++;
614 			send_ns = 1;
615 			/* Send NS to multicast address */
616 			pdst = NULL;
617 		} else {
618 			struct mbuf *m = ln->la_hold;
619 			if (m) {
620 				struct mbuf *m0;
621 
622 				/*
623 				 * assuming every packet in la_hold has the
624 				 * same IP header.  Send error after unlock.
625 				 */
626 				m0 = m->m_nextpkt;
627 				m->m_nextpkt = NULL;
628 				ln->la_hold = m0;
629 				clear_llinfo_pqueue(ln);
630 			}
631 			EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_TIMEDOUT);
632 			(void)nd6_free(ln, 0);
633 			ln = NULL;
634 			if (m != NULL)
635 				icmp6_error2(m, ICMP6_DST_UNREACH,
636 				    ICMP6_DST_UNREACH_ADDR, 0, ifp);
637 		}
638 		break;
639 	case ND6_LLINFO_REACHABLE:
640 		if (!ND6_LLINFO_PERMANENT(ln)) {
641 			ln->ln_state = ND6_LLINFO_STALE;
642 			nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz);
643 		}
644 		break;
645 
646 	case ND6_LLINFO_STALE:
647 		/* Garbage Collection(RFC 2461 5.3) */
648 		if (!ND6_LLINFO_PERMANENT(ln)) {
649 			EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_EXPIRED);
650 			(void)nd6_free(ln, 1);
651 			ln = NULL;
652 		}
653 		break;
654 
655 	case ND6_LLINFO_DELAY:
656 		if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) {
657 			/* We need NUD */
658 			ln->la_asked = 1;
659 			ln->ln_state = ND6_LLINFO_PROBE;
660 			send_ns = 1;
661 		} else {
662 			ln->ln_state = ND6_LLINFO_STALE; /* XXX */
663 			nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz);
664 		}
665 		break;
666 	case ND6_LLINFO_PROBE:
667 		if (ln->la_asked < V_nd6_umaxtries) {
668 			ln->la_asked++;
669 			send_ns = 1;
670 		} else {
671 			EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_EXPIRED);
672 			(void)nd6_free(ln, 0);
673 			ln = NULL;
674 		}
675 		break;
676 	default:
677 		panic("%s: paths in a dark night can be confusing: %d",
678 		    __func__, ln->ln_state);
679 	}
680 done:
681 	if (send_ns != 0) {
682 		nd6_llinfo_settimer_locked(ln, (long)ndi->retrans * hz / 1000);
683 		psrc = nd6_llinfo_get_holdsrc(ln, &src);
684 		LLE_FREE_LOCKED(ln);
685 		ln = NULL;
686 		nd6_ns_output(ifp, psrc, pdst, dst, NULL);
687 	}
688 
689 	if (ln != NULL)
690 		LLE_FREE_LOCKED(ln);
691 	CURVNET_RESTORE();
692 }
693 
694 
695 /*
696  * ND6 timer routine to expire default route list and prefix list
697  */
698 void
699 nd6_timer(void *arg)
700 {
701 	CURVNET_SET((struct vnet *) arg);
702 	struct nd_defrouter *dr, *ndr;
703 	struct nd_prefix *pr, *npr;
704 	struct in6_ifaddr *ia6, *nia6;
705 
706 	callout_reset(&V_nd6_timer_ch, V_nd6_prune * hz,
707 	    nd6_timer, curvnet);
708 
709 	/* expire default router list */
710 	TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr) {
711 		if (dr->expire && dr->expire < time_uptime)
712 			defrtrlist_del(dr);
713 	}
714 
715 	/*
716 	 * expire interface addresses.
717 	 * in the past the loop was inside prefix expiry processing.
718 	 * However, from a stricter speci-confrmance standpoint, we should
719 	 * rather separate address lifetimes and prefix lifetimes.
720 	 *
721 	 * XXXRW: in6_ifaddrhead locking.
722 	 */
723   addrloop:
724 	TAILQ_FOREACH_SAFE(ia6, &V_in6_ifaddrhead, ia_link, nia6) {
725 		/* check address lifetime */
726 		if (IFA6_IS_INVALID(ia6)) {
727 			int regen = 0;
728 
729 			/*
730 			 * If the expiring address is temporary, try
731 			 * regenerating a new one.  This would be useful when
732 			 * we suspended a laptop PC, then turned it on after a
733 			 * period that could invalidate all temporary
734 			 * addresses.  Although we may have to restart the
735 			 * loop (see below), it must be after purging the
736 			 * address.  Otherwise, we'd see an infinite loop of
737 			 * regeneration.
738 			 */
739 			if (V_ip6_use_tempaddr &&
740 			    (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
741 				if (regen_tmpaddr(ia6) == 0)
742 					regen = 1;
743 			}
744 
745 			in6_purgeaddr(&ia6->ia_ifa);
746 
747 			if (regen)
748 				goto addrloop; /* XXX: see below */
749 		} else if (IFA6_IS_DEPRECATED(ia6)) {
750 			int oldflags = ia6->ia6_flags;
751 
752 			ia6->ia6_flags |= IN6_IFF_DEPRECATED;
753 
754 			/*
755 			 * If a temporary address has just become deprecated,
756 			 * regenerate a new one if possible.
757 			 */
758 			if (V_ip6_use_tempaddr &&
759 			    (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
760 			    (oldflags & IN6_IFF_DEPRECATED) == 0) {
761 
762 				if (regen_tmpaddr(ia6) == 0) {
763 					/*
764 					 * A new temporary address is
765 					 * generated.
766 					 * XXX: this means the address chain
767 					 * has changed while we are still in
768 					 * the loop.  Although the change
769 					 * would not cause disaster (because
770 					 * it's not a deletion, but an
771 					 * addition,) we'd rather restart the
772 					 * loop just for safety.  Or does this
773 					 * significantly reduce performance??
774 					 */
775 					goto addrloop;
776 				}
777 			}
778 		} else {
779 			/*
780 			 * A new RA might have made a deprecated address
781 			 * preferred.
782 			 */
783 			ia6->ia6_flags &= ~IN6_IFF_DEPRECATED;
784 		}
785 	}
786 
787 	/* expire prefix list */
788 	LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
789 		/*
790 		 * check prefix lifetime.
791 		 * since pltime is just for autoconf, pltime processing for
792 		 * prefix is not necessary.
793 		 */
794 		if (pr->ndpr_vltime != ND6_INFINITE_LIFETIME &&
795 		    time_uptime - pr->ndpr_lastupdate > pr->ndpr_vltime) {
796 
797 			/*
798 			 * address expiration and prefix expiration are
799 			 * separate.  NEVER perform in6_purgeaddr here.
800 			 */
801 			prelist_remove(pr);
802 		}
803 	}
804 	CURVNET_RESTORE();
805 }
806 
807 /*
808  * ia6 - deprecated/invalidated temporary address
809  */
810 static int
811 regen_tmpaddr(struct in6_ifaddr *ia6)
812 {
813 	struct ifaddr *ifa;
814 	struct ifnet *ifp;
815 	struct in6_ifaddr *public_ifa6 = NULL;
816 
817 	ifp = ia6->ia_ifa.ifa_ifp;
818 	IF_ADDR_RLOCK(ifp);
819 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
820 		struct in6_ifaddr *it6;
821 
822 		if (ifa->ifa_addr->sa_family != AF_INET6)
823 			continue;
824 
825 		it6 = (struct in6_ifaddr *)ifa;
826 
827 		/* ignore no autoconf addresses. */
828 		if ((it6->ia6_flags & IN6_IFF_AUTOCONF) == 0)
829 			continue;
830 
831 		/* ignore autoconf addresses with different prefixes. */
832 		if (it6->ia6_ndpr == NULL || it6->ia6_ndpr != ia6->ia6_ndpr)
833 			continue;
834 
835 		/*
836 		 * Now we are looking at an autoconf address with the same
837 		 * prefix as ours.  If the address is temporary and is still
838 		 * preferred, do not create another one.  It would be rare, but
839 		 * could happen, for example, when we resume a laptop PC after
840 		 * a long period.
841 		 */
842 		if ((it6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
843 		    !IFA6_IS_DEPRECATED(it6)) {
844 			public_ifa6 = NULL;
845 			break;
846 		}
847 
848 		/*
849 		 * This is a public autoconf address that has the same prefix
850 		 * as ours.  If it is preferred, keep it.  We can't break the
851 		 * loop here, because there may be a still-preferred temporary
852 		 * address with the prefix.
853 		 */
854 		if (!IFA6_IS_DEPRECATED(it6))
855 			public_ifa6 = it6;
856 	}
857 	if (public_ifa6 != NULL)
858 		ifa_ref(&public_ifa6->ia_ifa);
859 	IF_ADDR_RUNLOCK(ifp);
860 
861 	if (public_ifa6 != NULL) {
862 		int e;
863 
864 		if ((e = in6_tmpifadd(public_ifa6, 0, 0)) != 0) {
865 			ifa_free(&public_ifa6->ia_ifa);
866 			log(LOG_NOTICE, "regen_tmpaddr: failed to create a new"
867 			    " tmp addr,errno=%d\n", e);
868 			return (-1);
869 		}
870 		ifa_free(&public_ifa6->ia_ifa);
871 		return (0);
872 	}
873 
874 	return (-1);
875 }
876 
877 /*
878  * Nuke neighbor cache/prefix/default router management table, right before
879  * ifp goes away.
880  */
881 void
882 nd6_purge(struct ifnet *ifp)
883 {
884 	struct nd_defrouter *dr, *ndr;
885 	struct nd_prefix *pr, *npr;
886 
887 	/*
888 	 * Nuke default router list entries toward ifp.
889 	 * We defer removal of default router list entries that is installed
890 	 * in the routing table, in order to keep additional side effects as
891 	 * small as possible.
892 	 */
893 	TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr) {
894 		if (dr->installed)
895 			continue;
896 
897 		if (dr->ifp == ifp)
898 			defrtrlist_del(dr);
899 	}
900 
901 	TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr) {
902 		if (!dr->installed)
903 			continue;
904 
905 		if (dr->ifp == ifp)
906 			defrtrlist_del(dr);
907 	}
908 
909 	/* Nuke prefix list entries toward ifp */
910 	LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
911 		if (pr->ndpr_ifp == ifp) {
912 			/*
913 			 * Because if_detach() does *not* release prefixes
914 			 * while purging addresses the reference count will
915 			 * still be above zero. We therefore reset it to
916 			 * make sure that the prefix really gets purged.
917 			 */
918 			pr->ndpr_refcnt = 0;
919 
920 			/*
921 			 * Previously, pr->ndpr_addr is removed as well,
922 			 * but I strongly believe we don't have to do it.
923 			 * nd6_purge() is only called from in6_ifdetach(),
924 			 * which removes all the associated interface addresses
925 			 * by itself.
926 			 * (jinmei@kame.net 20010129)
927 			 */
928 			prelist_remove(pr);
929 		}
930 	}
931 
932 	/* cancel default outgoing interface setting */
933 	if (V_nd6_defifindex == ifp->if_index)
934 		nd6_setdefaultiface(0);
935 
936 	if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
937 		/* Refresh default router list. */
938 		defrouter_select();
939 	}
940 
941 	/* XXXXX
942 	 * We do not nuke the neighbor cache entries here any more
943 	 * because the neighbor cache is kept in if_afdata[AF_INET6].
944 	 * nd6_purge() is invoked by in6_ifdetach() which is called
945 	 * from if_detach() where everything gets purged. So let
946 	 * in6_domifdetach() do the actual L2 table purging work.
947 	 */
948 }
949 
950 /*
951  * the caller acquires and releases the lock on the lltbls
952  * Returns the llentry locked
953  */
954 struct llentry *
955 nd6_lookup(struct in6_addr *addr6, int flags, struct ifnet *ifp)
956 {
957 	struct sockaddr_in6 sin6;
958 	struct llentry *ln;
959 	int llflags;
960 
961 	bzero(&sin6, sizeof(sin6));
962 	sin6.sin6_len = sizeof(struct sockaddr_in6);
963 	sin6.sin6_family = AF_INET6;
964 	sin6.sin6_addr = *addr6;
965 
966 	IF_AFDATA_LOCK_ASSERT(ifp);
967 
968 	llflags = (flags & ND6_EXCLUSIVE) ? LLE_EXCLUSIVE : 0;
969 	ln = lla_lookup(LLTABLE6(ifp), llflags, (struct sockaddr *)&sin6);
970 
971 	return (ln);
972 }
973 
974 struct llentry *
975 nd6_alloc(struct in6_addr *addr6, int flags, struct ifnet *ifp)
976 {
977 	struct sockaddr_in6 sin6;
978 	struct llentry *ln;
979 
980 	bzero(&sin6, sizeof(sin6));
981 	sin6.sin6_len = sizeof(struct sockaddr_in6);
982 	sin6.sin6_family = AF_INET6;
983 	sin6.sin6_addr = *addr6;
984 
985 	ln = lltable_alloc_entry(LLTABLE6(ifp), 0, (struct sockaddr *)&sin6);
986 	if (ln != NULL)
987 		ln->ln_state = ND6_LLINFO_NOSTATE;
988 
989 	return (ln);
990 }
991 
992 /*
993  * Test whether a given IPv6 address is a neighbor or not, ignoring
994  * the actual neighbor cache.  The neighbor cache is ignored in order
995  * to not reenter the routing code from within itself.
996  */
997 static int
998 nd6_is_new_addr_neighbor(struct sockaddr_in6 *addr, struct ifnet *ifp)
999 {
1000 	struct nd_prefix *pr;
1001 	struct ifaddr *dstaddr;
1002 
1003 	/*
1004 	 * A link-local address is always a neighbor.
1005 	 * XXX: a link does not necessarily specify a single interface.
1006 	 */
1007 	if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) {
1008 		struct sockaddr_in6 sin6_copy;
1009 		u_int32_t zone;
1010 
1011 		/*
1012 		 * We need sin6_copy since sa6_recoverscope() may modify the
1013 		 * content (XXX).
1014 		 */
1015 		sin6_copy = *addr;
1016 		if (sa6_recoverscope(&sin6_copy))
1017 			return (0); /* XXX: should be impossible */
1018 		if (in6_setscope(&sin6_copy.sin6_addr, ifp, &zone))
1019 			return (0);
1020 		if (sin6_copy.sin6_scope_id == zone)
1021 			return (1);
1022 		else
1023 			return (0);
1024 	}
1025 
1026 	/*
1027 	 * If the address matches one of our addresses,
1028 	 * it should be a neighbor.
1029 	 * If the address matches one of our on-link prefixes, it should be a
1030 	 * neighbor.
1031 	 */
1032 	LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
1033 		if (pr->ndpr_ifp != ifp)
1034 			continue;
1035 
1036 		if (!(pr->ndpr_stateflags & NDPRF_ONLINK)) {
1037 			struct rtentry *rt;
1038 
1039 			/* Always use the default FIB here. */
1040 			rt = in6_rtalloc1((struct sockaddr *)&pr->ndpr_prefix,
1041 			    0, 0, RT_DEFAULT_FIB);
1042 			if (rt == NULL)
1043 				continue;
1044 			/*
1045 			 * This is the case where multiple interfaces
1046 			 * have the same prefix, but only one is installed
1047 			 * into the routing table and that prefix entry
1048 			 * is not the one being examined here. In the case
1049 			 * where RADIX_MPATH is enabled, multiple route
1050 			 * entries (of the same rt_key value) will be
1051 			 * installed because the interface addresses all
1052 			 * differ.
1053 			 */
1054 			if (!IN6_ARE_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
1055 			       &((struct sockaddr_in6 *)rt_key(rt))->sin6_addr)) {
1056 				RTFREE_LOCKED(rt);
1057 				continue;
1058 			}
1059 			RTFREE_LOCKED(rt);
1060 		}
1061 
1062 		if (IN6_ARE_MASKED_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
1063 		    &addr->sin6_addr, &pr->ndpr_mask))
1064 			return (1);
1065 	}
1066 
1067 	/*
1068 	 * If the address is assigned on the node of the other side of
1069 	 * a p2p interface, the address should be a neighbor.
1070 	 */
1071 	dstaddr = ifa_ifwithdstaddr((struct sockaddr *)addr, RT_ALL_FIBS);
1072 	if (dstaddr != NULL) {
1073 		if (dstaddr->ifa_ifp == ifp) {
1074 			ifa_free(dstaddr);
1075 			return (1);
1076 		}
1077 		ifa_free(dstaddr);
1078 	}
1079 
1080 	/*
1081 	 * If the default router list is empty, all addresses are regarded
1082 	 * as on-link, and thus, as a neighbor.
1083 	 */
1084 	if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV &&
1085 	    TAILQ_EMPTY(&V_nd_defrouter) &&
1086 	    V_nd6_defifindex == ifp->if_index) {
1087 		return (1);
1088 	}
1089 
1090 	return (0);
1091 }
1092 
1093 
1094 /*
1095  * Detect if a given IPv6 address identifies a neighbor on a given link.
1096  * XXX: should take care of the destination of a p2p link?
1097  */
1098 int
1099 nd6_is_addr_neighbor(struct sockaddr_in6 *addr, struct ifnet *ifp)
1100 {
1101 	struct llentry *lle;
1102 	int rc = 0;
1103 
1104 	IF_AFDATA_UNLOCK_ASSERT(ifp);
1105 	if (nd6_is_new_addr_neighbor(addr, ifp))
1106 		return (1);
1107 
1108 	/*
1109 	 * Even if the address matches none of our addresses, it might be
1110 	 * in the neighbor cache.
1111 	 */
1112 	IF_AFDATA_RLOCK(ifp);
1113 	if ((lle = nd6_lookup(&addr->sin6_addr, 0, ifp)) != NULL) {
1114 		LLE_RUNLOCK(lle);
1115 		rc = 1;
1116 	}
1117 	IF_AFDATA_RUNLOCK(ifp);
1118 	return (rc);
1119 }
1120 
1121 /*
1122  * Free an nd6 llinfo entry.
1123  * Since the function would cause significant changes in the kernel, DO NOT
1124  * make it global, unless you have a strong reason for the change, and are sure
1125  * that the change is safe.
1126  */
1127 static struct llentry *
1128 nd6_free(struct llentry *ln, int gc)
1129 {
1130         struct llentry *next;
1131 	struct nd_defrouter *dr;
1132 	struct ifnet *ifp;
1133 
1134 	LLE_WLOCK_ASSERT(ln);
1135 
1136 	/*
1137 	 * we used to have pfctlinput(PRC_HOSTDEAD) here.
1138 	 * even though it is not harmful, it was not really necessary.
1139 	 */
1140 
1141 	/* cancel timer */
1142 	nd6_llinfo_settimer_locked(ln, -1);
1143 
1144 	ifp = ln->lle_tbl->llt_ifp;
1145 
1146 	if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
1147 		dr = defrouter_lookup(&ln->r_l3addr.addr6, ifp);
1148 
1149 		if (dr != NULL && dr->expire &&
1150 		    ln->ln_state == ND6_LLINFO_STALE && gc) {
1151 			/*
1152 			 * If the reason for the deletion is just garbage
1153 			 * collection, and the neighbor is an active default
1154 			 * router, do not delete it.  Instead, reset the GC
1155 			 * timer using the router's lifetime.
1156 			 * Simply deleting the entry would affect default
1157 			 * router selection, which is not necessarily a good
1158 			 * thing, especially when we're using router preference
1159 			 * values.
1160 			 * XXX: the check for ln_state would be redundant,
1161 			 *      but we intentionally keep it just in case.
1162 			 */
1163 			if (dr->expire > time_uptime)
1164 				nd6_llinfo_settimer_locked(ln,
1165 				    (dr->expire - time_uptime) * hz);
1166 			else
1167 				nd6_llinfo_settimer_locked(ln,
1168 				    (long)V_nd6_gctimer * hz);
1169 
1170 			next = LIST_NEXT(ln, lle_next);
1171 			LLE_REMREF(ln);
1172 			LLE_WUNLOCK(ln);
1173 			return (next);
1174 		}
1175 
1176 		if (dr) {
1177 			/*
1178 			 * Unreachablity of a router might affect the default
1179 			 * router selection and on-link detection of advertised
1180 			 * prefixes.
1181 			 */
1182 
1183 			/*
1184 			 * Temporarily fake the state to choose a new default
1185 			 * router and to perform on-link determination of
1186 			 * prefixes correctly.
1187 			 * Below the state will be set correctly,
1188 			 * or the entry itself will be deleted.
1189 			 */
1190 			ln->ln_state = ND6_LLINFO_INCOMPLETE;
1191 		}
1192 
1193 		if (ln->ln_router || dr) {
1194 
1195 			/*
1196 			 * We need to unlock to avoid a LOR with rt6_flush() with the
1197 			 * rnh and for the calls to pfxlist_onlink_check() and
1198 			 * defrouter_select() in the block further down for calls
1199 			 * into nd6_lookup().  We still hold a ref.
1200 			 */
1201 			LLE_WUNLOCK(ln);
1202 
1203 			/*
1204 			 * rt6_flush must be called whether or not the neighbor
1205 			 * is in the Default Router List.
1206 			 * See a corresponding comment in nd6_na_input().
1207 			 */
1208 			rt6_flush(&ln->r_l3addr.addr6, ifp);
1209 		}
1210 
1211 		if (dr) {
1212 			/*
1213 			 * Since defrouter_select() does not affect the
1214 			 * on-link determination and MIP6 needs the check
1215 			 * before the default router selection, we perform
1216 			 * the check now.
1217 			 */
1218 			pfxlist_onlink_check();
1219 
1220 			/*
1221 			 * Refresh default router list.
1222 			 */
1223 			defrouter_select();
1224 		}
1225 
1226 		if (ln->ln_router || dr)
1227 			LLE_WLOCK(ln);
1228 	}
1229 
1230 	/*
1231 	 * Before deleting the entry, remember the next entry as the
1232 	 * return value.  We need this because pfxlist_onlink_check() above
1233 	 * might have freed other entries (particularly the old next entry) as
1234 	 * a side effect (XXX).
1235 	 */
1236 	next = LIST_NEXT(ln, lle_next);
1237 
1238 	/*
1239 	 * Save to unlock. We still hold an extra reference and will not
1240 	 * free(9) in llentry_free() if someone else holds one as well.
1241 	 */
1242 	LLE_WUNLOCK(ln);
1243 	IF_AFDATA_LOCK(ifp);
1244 	LLE_WLOCK(ln);
1245 
1246 	/* Guard against race with other llentry_free(). */
1247 	if (ln->la_flags & LLE_LINKED) {
1248 		LLE_REMREF(ln);
1249 		llentry_free(ln);
1250 	} else
1251 		LLE_FREE_LOCKED(ln);
1252 
1253 	IF_AFDATA_UNLOCK(ifp);
1254 
1255 	return (next);
1256 }
1257 
1258 /*
1259  * Upper-layer reachability hint for Neighbor Unreachability Detection.
1260  *
1261  * XXX cost-effective methods?
1262  */
1263 void
1264 nd6_nud_hint(struct rtentry *rt, struct in6_addr *dst6, int force)
1265 {
1266 	struct llentry *ln;
1267 	struct ifnet *ifp;
1268 
1269 	if ((dst6 == NULL) || (rt == NULL))
1270 		return;
1271 
1272 	ifp = rt->rt_ifp;
1273 	IF_AFDATA_RLOCK(ifp);
1274 	ln = nd6_lookup(dst6, ND6_EXCLUSIVE, NULL);
1275 	IF_AFDATA_RUNLOCK(ifp);
1276 	if (ln == NULL)
1277 		return;
1278 
1279 	if (ln->ln_state < ND6_LLINFO_REACHABLE)
1280 		goto done;
1281 
1282 	/*
1283 	 * if we get upper-layer reachability confirmation many times,
1284 	 * it is possible we have false information.
1285 	 */
1286 	if (!force) {
1287 		ln->ln_byhint++;
1288 		if (ln->ln_byhint > V_nd6_maxnudhint) {
1289 			goto done;
1290 		}
1291 	}
1292 
1293  	ln->ln_state = ND6_LLINFO_REACHABLE;
1294 	if (!ND6_LLINFO_PERMANENT(ln)) {
1295 		nd6_llinfo_settimer_locked(ln,
1296 		    (long)ND_IFINFO(rt->rt_ifp)->reachable * hz);
1297 	}
1298 done:
1299 	LLE_WUNLOCK(ln);
1300 }
1301 
1302 
1303 /*
1304  * Rejuvenate this function for routing operations related
1305  * processing.
1306  */
1307 void
1308 nd6_rtrequest(int req, struct rtentry *rt, struct rt_addrinfo *info)
1309 {
1310 	struct sockaddr_in6 *gateway;
1311 	struct nd_defrouter *dr;
1312 	struct ifnet *ifp;
1313 
1314 	gateway = (struct sockaddr_in6 *)rt->rt_gateway;
1315 	ifp = rt->rt_ifp;
1316 
1317 	switch (req) {
1318 	case RTM_ADD:
1319 		break;
1320 
1321 	case RTM_DELETE:
1322 		if (!ifp)
1323 			return;
1324 		/*
1325 		 * Only indirect routes are interesting.
1326 		 */
1327 		if ((rt->rt_flags & RTF_GATEWAY) == 0)
1328 			return;
1329 		/*
1330 		 * check for default route
1331 		 */
1332 		if (IN6_ARE_ADDR_EQUAL(&in6addr_any,
1333 				       &SIN6(rt_key(rt))->sin6_addr)) {
1334 
1335 			dr = defrouter_lookup(&gateway->sin6_addr, ifp);
1336 			if (dr != NULL)
1337 				dr->installed = 0;
1338 		}
1339 		break;
1340 	}
1341 }
1342 
1343 
1344 int
1345 nd6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp)
1346 {
1347 	struct in6_ndireq *ndi = (struct in6_ndireq *)data;
1348 	struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data;
1349 	struct in6_ndifreq *ndif = (struct in6_ndifreq *)data;
1350 	int error = 0;
1351 
1352 	if (ifp->if_afdata[AF_INET6] == NULL)
1353 		return (EPFNOSUPPORT);
1354 	switch (cmd) {
1355 	case OSIOCGIFINFO_IN6:
1356 #define ND	ndi->ndi
1357 		/* XXX: old ndp(8) assumes a positive value for linkmtu. */
1358 		bzero(&ND, sizeof(ND));
1359 		ND.linkmtu = IN6_LINKMTU(ifp);
1360 		ND.maxmtu = ND_IFINFO(ifp)->maxmtu;
1361 		ND.basereachable = ND_IFINFO(ifp)->basereachable;
1362 		ND.reachable = ND_IFINFO(ifp)->reachable;
1363 		ND.retrans = ND_IFINFO(ifp)->retrans;
1364 		ND.flags = ND_IFINFO(ifp)->flags;
1365 		ND.recalctm = ND_IFINFO(ifp)->recalctm;
1366 		ND.chlim = ND_IFINFO(ifp)->chlim;
1367 		break;
1368 	case SIOCGIFINFO_IN6:
1369 		ND = *ND_IFINFO(ifp);
1370 		break;
1371 	case SIOCSIFINFO_IN6:
1372 		/*
1373 		 * used to change host variables from userland.
1374 		 * intented for a use on router to reflect RA configurations.
1375 		 */
1376 		/* 0 means 'unspecified' */
1377 		if (ND.linkmtu != 0) {
1378 			if (ND.linkmtu < IPV6_MMTU ||
1379 			    ND.linkmtu > IN6_LINKMTU(ifp)) {
1380 				error = EINVAL;
1381 				break;
1382 			}
1383 			ND_IFINFO(ifp)->linkmtu = ND.linkmtu;
1384 		}
1385 
1386 		if (ND.basereachable != 0) {
1387 			int obasereachable = ND_IFINFO(ifp)->basereachable;
1388 
1389 			ND_IFINFO(ifp)->basereachable = ND.basereachable;
1390 			if (ND.basereachable != obasereachable)
1391 				ND_IFINFO(ifp)->reachable =
1392 				    ND_COMPUTE_RTIME(ND.basereachable);
1393 		}
1394 		if (ND.retrans != 0)
1395 			ND_IFINFO(ifp)->retrans = ND.retrans;
1396 		if (ND.chlim != 0)
1397 			ND_IFINFO(ifp)->chlim = ND.chlim;
1398 		/* FALLTHROUGH */
1399 	case SIOCSIFINFO_FLAGS:
1400 	{
1401 		struct ifaddr *ifa;
1402 		struct in6_ifaddr *ia;
1403 
1404 		if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
1405 		    !(ND.flags & ND6_IFF_IFDISABLED)) {
1406 			/* ifdisabled 1->0 transision */
1407 
1408 			/*
1409 			 * If the interface is marked as ND6_IFF_IFDISABLED and
1410 			 * has an link-local address with IN6_IFF_DUPLICATED,
1411 			 * do not clear ND6_IFF_IFDISABLED.
1412 			 * See RFC 4862, Section 5.4.5.
1413 			 */
1414 			IF_ADDR_RLOCK(ifp);
1415 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1416 				if (ifa->ifa_addr->sa_family != AF_INET6)
1417 					continue;
1418 				ia = (struct in6_ifaddr *)ifa;
1419 				if ((ia->ia6_flags & IN6_IFF_DUPLICATED) &&
1420 				    IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia)))
1421 					break;
1422 			}
1423 			IF_ADDR_RUNLOCK(ifp);
1424 
1425 			if (ifa != NULL) {
1426 				/* LLA is duplicated. */
1427 				ND.flags |= ND6_IFF_IFDISABLED;
1428 				log(LOG_ERR, "Cannot enable an interface"
1429 				    " with a link-local address marked"
1430 				    " duplicate.\n");
1431 			} else {
1432 				ND_IFINFO(ifp)->flags &= ~ND6_IFF_IFDISABLED;
1433 				if (ifp->if_flags & IFF_UP)
1434 					in6_if_up(ifp);
1435 			}
1436 		} else if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
1437 			    (ND.flags & ND6_IFF_IFDISABLED)) {
1438 			/* ifdisabled 0->1 transision */
1439 			/* Mark all IPv6 address as tentative. */
1440 
1441 			ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
1442 			if ((ND_IFINFO(ifp)->flags & ND6_IFF_NO_DAD) == 0) {
1443 				IF_ADDR_RLOCK(ifp);
1444 				TAILQ_FOREACH(ifa, &ifp->if_addrhead,
1445 				    ifa_link) {
1446 					if (ifa->ifa_addr->sa_family !=
1447 					    AF_INET6)
1448 						continue;
1449 					ia = (struct in6_ifaddr *)ifa;
1450 					ia->ia6_flags |= IN6_IFF_TENTATIVE;
1451 				}
1452 				IF_ADDR_RUNLOCK(ifp);
1453 			}
1454 		}
1455 
1456 		if (ND.flags & ND6_IFF_AUTO_LINKLOCAL) {
1457 			if (!(ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL)) {
1458 				/* auto_linklocal 0->1 transision */
1459 
1460 				/* If no link-local address on ifp, configure */
1461 				ND_IFINFO(ifp)->flags |= ND6_IFF_AUTO_LINKLOCAL;
1462 				in6_ifattach(ifp, NULL);
1463 			} else if (!(ND.flags & ND6_IFF_IFDISABLED) &&
1464 			    ifp->if_flags & IFF_UP) {
1465 				/*
1466 				 * When the IF already has
1467 				 * ND6_IFF_AUTO_LINKLOCAL, no link-local
1468 				 * address is assigned, and IFF_UP, try to
1469 				 * assign one.
1470 				 */
1471 				IF_ADDR_RLOCK(ifp);
1472 				TAILQ_FOREACH(ifa, &ifp->if_addrhead,
1473 				    ifa_link) {
1474 					if (ifa->ifa_addr->sa_family !=
1475 					    AF_INET6)
1476 						continue;
1477 					ia = (struct in6_ifaddr *)ifa;
1478 					if (IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia)))
1479 						break;
1480 				}
1481 				IF_ADDR_RUNLOCK(ifp);
1482 				if (ifa != NULL)
1483 					/* No LLA is configured. */
1484 					in6_ifattach(ifp, NULL);
1485 			}
1486 		}
1487 	}
1488 		ND_IFINFO(ifp)->flags = ND.flags;
1489 		break;
1490 #undef ND
1491 	case SIOCSNDFLUSH_IN6:	/* XXX: the ioctl name is confusing... */
1492 		/* sync kernel routing table with the default router list */
1493 		defrouter_reset();
1494 		defrouter_select();
1495 		break;
1496 	case SIOCSPFXFLUSH_IN6:
1497 	{
1498 		/* flush all the prefix advertised by routers */
1499 		struct nd_prefix *pr, *next;
1500 
1501 		LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, next) {
1502 			struct in6_ifaddr *ia, *ia_next;
1503 
1504 			if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1505 				continue; /* XXX */
1506 
1507 			/* do we really have to remove addresses as well? */
1508 			/* XXXRW: in6_ifaddrhead locking. */
1509 			TAILQ_FOREACH_SAFE(ia, &V_in6_ifaddrhead, ia_link,
1510 			    ia_next) {
1511 				if ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1512 					continue;
1513 
1514 				if (ia->ia6_ndpr == pr)
1515 					in6_purgeaddr(&ia->ia_ifa);
1516 			}
1517 			prelist_remove(pr);
1518 		}
1519 		break;
1520 	}
1521 	case SIOCSRTRFLUSH_IN6:
1522 	{
1523 		/* flush all the default routers */
1524 		struct nd_defrouter *dr, *next;
1525 
1526 		defrouter_reset();
1527 		TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, next) {
1528 			defrtrlist_del(dr);
1529 		}
1530 		defrouter_select();
1531 		break;
1532 	}
1533 	case SIOCGNBRINFO_IN6:
1534 	{
1535 		struct llentry *ln;
1536 		struct in6_addr nb_addr = nbi->addr; /* make local for safety */
1537 
1538 		if ((error = in6_setscope(&nb_addr, ifp, NULL)) != 0)
1539 			return (error);
1540 
1541 		IF_AFDATA_RLOCK(ifp);
1542 		ln = nd6_lookup(&nb_addr, 0, ifp);
1543 		IF_AFDATA_RUNLOCK(ifp);
1544 
1545 		if (ln == NULL) {
1546 			error = EINVAL;
1547 			break;
1548 		}
1549 		nbi->state = ln->ln_state;
1550 		nbi->asked = ln->la_asked;
1551 		nbi->isrouter = ln->ln_router;
1552 		if (ln->la_expire == 0)
1553 			nbi->expire = 0;
1554 		else
1555 			nbi->expire = ln->la_expire +
1556 			    (time_second - time_uptime);
1557 		LLE_RUNLOCK(ln);
1558 		break;
1559 	}
1560 	case SIOCGDEFIFACE_IN6:	/* XXX: should be implemented as a sysctl? */
1561 		ndif->ifindex = V_nd6_defifindex;
1562 		break;
1563 	case SIOCSDEFIFACE_IN6:	/* XXX: should be implemented as a sysctl? */
1564 		return (nd6_setdefaultiface(ndif->ifindex));
1565 	}
1566 	return (error);
1567 }
1568 
1569 /*
1570  * Create neighbor cache entry and cache link-layer address,
1571  * on reception of inbound ND6 packets.  (RS/RA/NS/redirect)
1572  *
1573  * type - ICMP6 type
1574  * code - type dependent information
1575  *
1576  * XXXXX
1577  *  The caller of this function already acquired the ndp
1578  *  cache table lock because the cache entry is returned.
1579  */
1580 struct llentry *
1581 nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr,
1582     int lladdrlen, int type, int code)
1583 {
1584 	struct llentry *ln = NULL, *ln_tmp;
1585 	int is_newentry;
1586 	int do_update;
1587 	int olladdr;
1588 	int llchange;
1589 	int flags;
1590 	int newstate = 0;
1591 	uint16_t router = 0;
1592 	struct sockaddr_in6 sin6;
1593 	struct mbuf *chain = NULL;
1594 	int static_route = 0;
1595 
1596 	IF_AFDATA_UNLOCK_ASSERT(ifp);
1597 
1598 	KASSERT(ifp != NULL, ("%s: ifp == NULL", __func__));
1599 	KASSERT(from != NULL, ("%s: from == NULL", __func__));
1600 
1601 	/* nothing must be updated for unspecified address */
1602 	if (IN6_IS_ADDR_UNSPECIFIED(from))
1603 		return NULL;
1604 
1605 	/*
1606 	 * Validation about ifp->if_addrlen and lladdrlen must be done in
1607 	 * the caller.
1608 	 *
1609 	 * XXX If the link does not have link-layer adderss, what should
1610 	 * we do? (ifp->if_addrlen == 0)
1611 	 * Spec says nothing in sections for RA, RS and NA.  There's small
1612 	 * description on it in NS section (RFC 2461 7.2.3).
1613 	 */
1614 	flags = lladdr ? ND6_EXCLUSIVE : 0;
1615 	IF_AFDATA_RLOCK(ifp);
1616 	ln = nd6_lookup(from, flags, ifp);
1617 	IF_AFDATA_RUNLOCK(ifp);
1618 	is_newentry = 0;
1619 	if (ln == NULL) {
1620 		flags |= ND6_EXCLUSIVE;
1621 		ln = nd6_alloc(from, 0, ifp);
1622 		if (ln == NULL)
1623 			return (NULL);
1624 		IF_AFDATA_WLOCK(ifp);
1625 		LLE_WLOCK(ln);
1626 		/* Prefer any existing lle over newly-created one */
1627 		ln_tmp = nd6_lookup(from, ND6_EXCLUSIVE, ifp);
1628 		if (ln_tmp == NULL)
1629 			lltable_link_entry(LLTABLE6(ifp), ln);
1630 		IF_AFDATA_WUNLOCK(ifp);
1631 		if (ln_tmp == NULL)
1632 			/* No existing lle, mark as new entry */
1633 			is_newentry = 1;
1634 		else {
1635 			lltable_free_entry(LLTABLE6(ifp), ln);
1636 			ln = ln_tmp;
1637 			ln_tmp = NULL;
1638 		}
1639 	}
1640 	/* do nothing if static ndp is set */
1641 	if ((ln->la_flags & LLE_STATIC)) {
1642 			static_route = 1;
1643 			goto done;
1644 	}
1645 
1646 	olladdr = (ln->la_flags & LLE_VALID) ? 1 : 0;
1647 	if (olladdr && lladdr) {
1648 		llchange = bcmp(lladdr, &ln->ll_addr,
1649 		    ifp->if_addrlen);
1650 	} else
1651 		llchange = 0;
1652 
1653 	/*
1654 	 * newentry olladdr  lladdr  llchange	(*=record)
1655 	 *	0	n	n	--	(1)
1656 	 *	0	y	n	--	(2)
1657 	 *	0	n	y	--	(3) * STALE
1658 	 *	0	y	y	n	(4) *
1659 	 *	0	y	y	y	(5) * STALE
1660 	 *	1	--	n	--	(6)   NOSTATE(= PASSIVE)
1661 	 *	1	--	y	--	(7) * STALE
1662 	 */
1663 
1664 	if (lladdr) {		/* (3-5) and (7) */
1665 		/*
1666 		 * Record source link-layer address
1667 		 * XXX is it dependent to ifp->if_type?
1668 		 */
1669 		bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen);
1670 		ln->la_flags |= LLE_VALID;
1671 		EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
1672 	}
1673 
1674 	if (!is_newentry) {
1675 		if ((!olladdr && lladdr != NULL) ||	/* (3) */
1676 		    (olladdr && lladdr != NULL && llchange)) {	/* (5) */
1677 			do_update = 1;
1678 			newstate = ND6_LLINFO_STALE;
1679 		} else					/* (1-2,4) */
1680 			do_update = 0;
1681 	} else {
1682 		do_update = 1;
1683 		if (lladdr == NULL)			/* (6) */
1684 			newstate = ND6_LLINFO_NOSTATE;
1685 		else					/* (7) */
1686 			newstate = ND6_LLINFO_STALE;
1687 	}
1688 
1689 	if (do_update) {
1690 		/*
1691 		 * Update the state of the neighbor cache.
1692 		 */
1693 		ln->ln_state = newstate;
1694 
1695 		if (ln->ln_state == ND6_LLINFO_STALE) {
1696 			if (ln->la_hold != NULL)
1697 				nd6_grab_holdchain(ln, &chain, &sin6);
1698 		} else if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
1699 			/* probe right away */
1700 			nd6_llinfo_settimer_locked((void *)ln, 0);
1701 		}
1702 	}
1703 
1704 	/*
1705 	 * ICMP6 type dependent behavior.
1706 	 *
1707 	 * NS: clear IsRouter if new entry
1708 	 * RS: clear IsRouter
1709 	 * RA: set IsRouter if there's lladdr
1710 	 * redir: clear IsRouter if new entry
1711 	 *
1712 	 * RA case, (1):
1713 	 * The spec says that we must set IsRouter in the following cases:
1714 	 * - If lladdr exist, set IsRouter.  This means (1-5).
1715 	 * - If it is old entry (!newentry), set IsRouter.  This means (7).
1716 	 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
1717 	 * A quetion arises for (1) case.  (1) case has no lladdr in the
1718 	 * neighbor cache, this is similar to (6).
1719 	 * This case is rare but we figured that we MUST NOT set IsRouter.
1720 	 *
1721 	 * newentry olladdr  lladdr  llchange	    NS  RS  RA	redir
1722 	 *							D R
1723 	 *	0	n	n	--	(1)	c   ?     s
1724 	 *	0	y	n	--	(2)	c   s     s
1725 	 *	0	n	y	--	(3)	c   s     s
1726 	 *	0	y	y	n	(4)	c   s     s
1727 	 *	0	y	y	y	(5)	c   s     s
1728 	 *	1	--	n	--	(6) c	c	c s
1729 	 *	1	--	y	--	(7) c	c   s	c s
1730 	 *
1731 	 *					(c=clear s=set)
1732 	 */
1733 	switch (type & 0xff) {
1734 	case ND_NEIGHBOR_SOLICIT:
1735 		/*
1736 		 * New entry must have is_router flag cleared.
1737 		 */
1738 		if (is_newentry)	/* (6-7) */
1739 			ln->ln_router = 0;
1740 		break;
1741 	case ND_REDIRECT:
1742 		/*
1743 		 * If the icmp is a redirect to a better router, always set the
1744 		 * is_router flag.  Otherwise, if the entry is newly created,
1745 		 * clear the flag.  [RFC 2461, sec 8.3]
1746 		 */
1747 		if (code == ND_REDIRECT_ROUTER)
1748 			ln->ln_router = 1;
1749 		else if (is_newentry) /* (6-7) */
1750 			ln->ln_router = 0;
1751 		break;
1752 	case ND_ROUTER_SOLICIT:
1753 		/*
1754 		 * is_router flag must always be cleared.
1755 		 */
1756 		ln->ln_router = 0;
1757 		break;
1758 	case ND_ROUTER_ADVERT:
1759 		/*
1760 		 * Mark an entry with lladdr as a router.
1761 		 */
1762 		if ((!is_newentry && (olladdr || lladdr)) ||	/* (2-5) */
1763 		    (is_newentry && lladdr)) {			/* (7) */
1764 			ln->ln_router = 1;
1765 		}
1766 		break;
1767 	}
1768 
1769 	if (ln != NULL) {
1770 		static_route = (ln->la_flags & LLE_STATIC);
1771 		router = ln->ln_router;
1772 
1773 		if (flags & ND6_EXCLUSIVE)
1774 			LLE_WUNLOCK(ln);
1775 		else
1776 			LLE_RUNLOCK(ln);
1777 		if (static_route)
1778 			ln = NULL;
1779 	}
1780 	if (chain != NULL)
1781 		nd6_flush_holdchain(ifp, ifp, chain, &sin6);
1782 
1783 	/*
1784 	 * When the link-layer address of a router changes, select the
1785 	 * best router again.  In particular, when the neighbor entry is newly
1786 	 * created, it might affect the selection policy.
1787 	 * Question: can we restrict the first condition to the "is_newentry"
1788 	 * case?
1789 	 * XXX: when we hear an RA from a new router with the link-layer
1790 	 * address option, defrouter_select() is called twice, since
1791 	 * defrtrlist_update called the function as well.  However, I believe
1792 	 * we can compromise the overhead, since it only happens the first
1793 	 * time.
1794 	 * XXX: although defrouter_select() should not have a bad effect
1795 	 * for those are not autoconfigured hosts, we explicitly avoid such
1796 	 * cases for safety.
1797 	 */
1798 	if (do_update && router &&
1799 	    ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
1800 		/*
1801 		 * guaranteed recursion
1802 		 */
1803 		defrouter_select();
1804 	}
1805 
1806 	return (ln);
1807 done:
1808 	if (ln != NULL) {
1809 		if (flags & ND6_EXCLUSIVE)
1810 			LLE_WUNLOCK(ln);
1811 		else
1812 			LLE_RUNLOCK(ln);
1813 		if (static_route)
1814 			ln = NULL;
1815 	}
1816 	return (ln);
1817 }
1818 
1819 static void
1820 nd6_slowtimo(void *arg)
1821 {
1822 	CURVNET_SET((struct vnet *) arg);
1823 	struct nd_ifinfo *nd6if;
1824 	struct ifnet *ifp;
1825 
1826 	callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
1827 	    nd6_slowtimo, curvnet);
1828 	IFNET_RLOCK_NOSLEEP();
1829 	TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
1830 		if (ifp->if_afdata[AF_INET6] == NULL)
1831 			continue;
1832 		nd6if = ND_IFINFO(ifp);
1833 		if (nd6if->basereachable && /* already initialized */
1834 		    (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
1835 			/*
1836 			 * Since reachable time rarely changes by router
1837 			 * advertisements, we SHOULD insure that a new random
1838 			 * value gets recomputed at least once every few hours.
1839 			 * (RFC 2461, 6.3.4)
1840 			 */
1841 			nd6if->recalctm = V_nd6_recalc_reachtm_interval;
1842 			nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable);
1843 		}
1844 	}
1845 	IFNET_RUNLOCK_NOSLEEP();
1846 	CURVNET_RESTORE();
1847 }
1848 
1849 void
1850 nd6_grab_holdchain(struct llentry *ln, struct mbuf **chain,
1851     struct sockaddr_in6 *sin6)
1852 {
1853 
1854 	LLE_WLOCK_ASSERT(ln);
1855 
1856 	*chain = ln->la_hold;
1857 	ln->la_hold = NULL;
1858 	lltable_fill_sa_entry(ln, (struct sockaddr *)sin6);
1859 
1860 	if (ln->ln_state == ND6_LLINFO_STALE) {
1861 
1862 		/*
1863 		 * The first time we send a packet to a
1864 		 * neighbor whose entry is STALE, we have
1865 		 * to change the state to DELAY and a sets
1866 		 * a timer to expire in DELAY_FIRST_PROBE_TIME
1867 		 * seconds to ensure do neighbor unreachability
1868 		 * detection on expiration.
1869 		 * (RFC 2461 7.3.3)
1870 		 */
1871 		ln->la_asked = 0;
1872 		ln->ln_state = ND6_LLINFO_DELAY;
1873 		nd6_llinfo_settimer_locked(ln, (long)V_nd6_delay * hz);
1874 	}
1875 }
1876 
1877 static int
1878 nd6_output_ifp(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
1879     struct sockaddr_in6 *dst)
1880 {
1881 	int error;
1882 	int ip6len;
1883 	struct ip6_hdr *ip6;
1884 	struct m_tag *mtag;
1885 
1886 #ifdef MAC
1887 	mac_netinet6_nd6_send(ifp, m);
1888 #endif
1889 
1890 	/*
1891 	 * If called from nd6_ns_output() (NS), nd6_na_output() (NA),
1892 	 * icmp6_redirect_output() (REDIRECT) or from rip6_output() (RS, RA
1893 	 * as handled by rtsol and rtadvd), mbufs will be tagged for SeND
1894 	 * to be diverted to user space.  When re-injected into the kernel,
1895 	 * send_output() will directly dispatch them to the outgoing interface.
1896 	 */
1897 	if (send_sendso_input_hook != NULL) {
1898 		mtag = m_tag_find(m, PACKET_TAG_ND_OUTGOING, NULL);
1899 		if (mtag != NULL) {
1900 			ip6 = mtod(m, struct ip6_hdr *);
1901 			ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
1902 			/* Use the SEND socket */
1903 			error = send_sendso_input_hook(m, ifp, SND_OUT,
1904 			    ip6len);
1905 			/* -1 == no app on SEND socket */
1906 			if (error == 0 || error != -1)
1907 			    return (error);
1908 		}
1909 	}
1910 
1911 	m_clrprotoflags(m);	/* Avoid confusing lower layers. */
1912 	IP_PROBE(send, NULL, NULL, mtod(m, struct ip6_hdr *), ifp, NULL,
1913 	    mtod(m, struct ip6_hdr *));
1914 
1915 	if ((ifp->if_flags & IFF_LOOPBACK) == 0)
1916 		origifp = ifp;
1917 
1918 	error = (*ifp->if_output)(origifp, m, (struct sockaddr *)dst, NULL);
1919 	return (error);
1920 }
1921 
1922 /*
1923  * IPv6 packet output - light version.
1924  * Checks if destination LLE exists and is in proper state
1925  * (e.g no modification required). If not true, fall back to
1926  * "heavy" version.
1927  */
1928 int
1929 nd6_output(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
1930     struct sockaddr_in6 *dst, struct rtentry *rt0)
1931 {
1932 	struct llentry *ln = NULL;
1933 
1934 	/* discard the packet if IPv6 operation is disabled on the interface */
1935 	if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED)) {
1936 		m_freem(m);
1937 		return (ENETDOWN); /* better error? */
1938 	}
1939 
1940 	if (IN6_IS_ADDR_MULTICAST(&dst->sin6_addr))
1941 		goto sendpkt;
1942 
1943 	if (nd6_need_cache(ifp) == 0)
1944 		goto sendpkt;
1945 
1946 	IF_AFDATA_RLOCK(ifp);
1947 	ln = nd6_lookup(&dst->sin6_addr, 0, ifp);
1948 	IF_AFDATA_RUNLOCK(ifp);
1949 
1950 	/*
1951 	 * Perform fast path for the following cases:
1952 	 * 1) lle state is REACHABLE
1953 	 * 2) lle state is DELAY (NS message sentNS message sent)
1954 	 *
1955 	 * Every other case involves lle modification, so we handle
1956 	 * them separately.
1957 	 */
1958 	if (ln == NULL || (ln->ln_state != ND6_LLINFO_REACHABLE &&
1959 	    ln->ln_state != ND6_LLINFO_DELAY)) {
1960 		/* Fall back to slow processing path */
1961 		if (ln != NULL)
1962 			LLE_RUNLOCK(ln);
1963 		return (nd6_output_lle(ifp, origifp, m, dst));
1964 	}
1965 
1966 sendpkt:
1967 	if (ln != NULL)
1968 		LLE_RUNLOCK(ln);
1969 
1970 	return (nd6_output_ifp(ifp, origifp, m, dst));
1971 }
1972 
1973 
1974 /*
1975  * Output IPv6 packet - heavy version.
1976  * Function assume that either
1977  * 1) destination LLE does not exist, is invalid or stale, so
1978  *   ND6_EXCLUSIVE lock needs to be acquired
1979  * 2) destination lle is provided (with ND6_EXCLUSIVE lock),
1980  *   in that case packets are queued in &chain.
1981  *
1982  */
1983 static int
1984 nd6_output_lle(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
1985     struct sockaddr_in6 *dst)
1986 {
1987 	struct llentry *lle = NULL, *lle_tmp;
1988 
1989 	KASSERT(m != NULL, ("NULL mbuf, nothing to send"));
1990 	/* discard the packet if IPv6 operation is disabled on the interface */
1991 	if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED)) {
1992 		m_freem(m);
1993 		return (ENETDOWN); /* better error? */
1994 	}
1995 
1996 	if (IN6_IS_ADDR_MULTICAST(&dst->sin6_addr))
1997 		goto sendpkt;
1998 
1999 	if (nd6_need_cache(ifp) == 0)
2000 		goto sendpkt;
2001 
2002 	/*
2003 	 * Address resolution or Neighbor Unreachability Detection
2004 	 * for the next hop.
2005 	 * At this point, the destination of the packet must be a unicast
2006 	 * or an anycast address(i.e. not a multicast).
2007 	 */
2008 	if (lle == NULL) {
2009 		IF_AFDATA_RLOCK(ifp);
2010 		lle = nd6_lookup(&dst->sin6_addr, ND6_EXCLUSIVE, ifp);
2011 		IF_AFDATA_RUNLOCK(ifp);
2012 		if ((lle == NULL) && nd6_is_addr_neighbor(dst, ifp))  {
2013 			/*
2014 			 * Since nd6_is_addr_neighbor() internally calls nd6_lookup(),
2015 			 * the condition below is not very efficient.  But we believe
2016 			 * it is tolerable, because this should be a rare case.
2017 			 */
2018 			lle = nd6_alloc(&dst->sin6_addr, 0, ifp);
2019 			if (lle == NULL) {
2020 				char ip6buf[INET6_ADDRSTRLEN];
2021 				log(LOG_DEBUG,
2022 				    "nd6_output: can't allocate llinfo for %s "
2023 				    "(ln=%p)\n",
2024 				    ip6_sprintf(ip6buf, &dst->sin6_addr), lle);
2025 				m_freem(m);
2026 				return (ENOBUFS);
2027 			}
2028 			lle->ln_state = ND6_LLINFO_NOSTATE;
2029 
2030 			IF_AFDATA_WLOCK(ifp);
2031 			LLE_WLOCK(lle);
2032 			/* Prefer any existing entry over newly-created one */
2033 			lle_tmp = nd6_lookup(&dst->sin6_addr, ND6_EXCLUSIVE, ifp);
2034 			if (lle_tmp == NULL)
2035 				lltable_link_entry(LLTABLE6(ifp), lle);
2036 			IF_AFDATA_WUNLOCK(ifp);
2037 			if (lle_tmp != NULL) {
2038 				lltable_free_entry(LLTABLE6(ifp), lle);
2039 				lle = lle_tmp;
2040 				lle_tmp = NULL;
2041 			}
2042 		}
2043 	}
2044 	if (lle == NULL) {
2045 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0 &&
2046 		    !(ND_IFINFO(ifp)->flags & ND6_IFF_PERFORMNUD)) {
2047 			m_freem(m);
2048 			return (ENOBUFS);
2049 		}
2050 		goto sendpkt;	/* send anyway */
2051 	}
2052 
2053 	LLE_WLOCK_ASSERT(lle);
2054 
2055 	/* We don't have to do link-layer address resolution on a p2p link. */
2056 	if ((ifp->if_flags & IFF_POINTOPOINT) != 0 &&
2057 	    lle->ln_state < ND6_LLINFO_REACHABLE) {
2058 		lle->ln_state = ND6_LLINFO_STALE;
2059 		nd6_llinfo_settimer_locked(lle, (long)V_nd6_gctimer * hz);
2060 	}
2061 
2062 	/*
2063 	 * The first time we send a packet to a neighbor whose entry is
2064 	 * STALE, we have to change the state to DELAY and a sets a timer to
2065 	 * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do
2066 	 * neighbor unreachability detection on expiration.
2067 	 * (RFC 2461 7.3.3)
2068 	 */
2069 	if (lle->ln_state == ND6_LLINFO_STALE) {
2070 		lle->la_asked = 0;
2071 		lle->ln_state = ND6_LLINFO_DELAY;
2072 		nd6_llinfo_settimer_locked(lle, (long)V_nd6_delay * hz);
2073 	}
2074 
2075 	/*
2076 	 * If the neighbor cache entry has a state other than INCOMPLETE
2077 	 * (i.e. its link-layer address is already resolved), just
2078 	 * send the packet.
2079 	 */
2080 	if (lle->ln_state > ND6_LLINFO_INCOMPLETE)
2081 		goto sendpkt;
2082 
2083 	/*
2084 	 * There is a neighbor cache entry, but no ethernet address
2085 	 * response yet.  Append this latest packet to the end of the
2086 	 * packet queue in the mbuf, unless the number of the packet
2087 	 * does not exceed nd6_maxqueuelen.  When it exceeds nd6_maxqueuelen,
2088 	 * the oldest packet in the queue will be removed.
2089 	 */
2090 	if (lle->ln_state == ND6_LLINFO_NOSTATE)
2091 		lle->ln_state = ND6_LLINFO_INCOMPLETE;
2092 
2093 	if (lle->la_hold != NULL) {
2094 		struct mbuf *m_hold;
2095 		int i;
2096 
2097 		i = 0;
2098 		for (m_hold = lle->la_hold; m_hold; m_hold = m_hold->m_nextpkt){
2099 			i++;
2100 			if (m_hold->m_nextpkt == NULL) {
2101 				m_hold->m_nextpkt = m;
2102 				break;
2103 			}
2104 		}
2105 		while (i >= V_nd6_maxqueuelen) {
2106 			m_hold = lle->la_hold;
2107 			lle->la_hold = lle->la_hold->m_nextpkt;
2108 			m_freem(m_hold);
2109 			i--;
2110 		}
2111 	} else {
2112 		lle->la_hold = m;
2113 	}
2114 
2115 	/*
2116 	 * If there has been no NS for the neighbor after entering the
2117 	 * INCOMPLETE state, send the first solicitation.
2118 	 */
2119 	if (!ND6_LLINFO_PERMANENT(lle) && lle->la_asked == 0) {
2120 		struct in6_addr src, *psrc;
2121 		lle->la_asked++;
2122 
2123 		nd6_llinfo_settimer_locked(lle,
2124 		    (long)ND_IFINFO(ifp)->retrans * hz / 1000);
2125 		psrc = nd6_llinfo_get_holdsrc(lle, &src);
2126 		LLE_WUNLOCK(lle);
2127 		nd6_ns_output(ifp, psrc, NULL, &dst->sin6_addr, NULL);
2128 	} else {
2129 		/* We did the lookup so we need to do the unlock here. */
2130 		LLE_WUNLOCK(lle);
2131 	}
2132 
2133 	return (0);
2134 
2135   sendpkt:
2136 	if (lle != NULL)
2137 		LLE_WUNLOCK(lle);
2138 
2139 	return (nd6_output_ifp(ifp, origifp, m, dst));
2140 }
2141 
2142 
2143 int
2144 nd6_flush_holdchain(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *chain,
2145     struct sockaddr_in6 *dst)
2146 {
2147 	struct mbuf *m, *m_head;
2148 	struct ifnet *outifp;
2149 	int error = 0;
2150 
2151 	m_head = chain;
2152 	if ((ifp->if_flags & IFF_LOOPBACK) != 0)
2153 		outifp = origifp;
2154 	else
2155 		outifp = ifp;
2156 
2157 	while (m_head) {
2158 		m = m_head;
2159 		m_head = m_head->m_nextpkt;
2160 		error = nd6_output_ifp(ifp, origifp, m, dst);
2161 	}
2162 
2163 	/*
2164 	 * XXX
2165 	 * note that intermediate errors are blindly ignored - but this is
2166 	 * the same convention as used with nd6_output when called by
2167 	 * nd6_cache_lladdr
2168 	 */
2169 	return (error);
2170 }
2171 
2172 
2173 int
2174 nd6_need_cache(struct ifnet *ifp)
2175 {
2176 	/*
2177 	 * XXX: we currently do not make neighbor cache on any interface
2178 	 * other than ARCnet, Ethernet, FDDI and GIF.
2179 	 *
2180 	 * RFC2893 says:
2181 	 * - unidirectional tunnels needs no ND
2182 	 */
2183 	switch (ifp->if_type) {
2184 	case IFT_ARCNET:
2185 	case IFT_ETHER:
2186 	case IFT_FDDI:
2187 	case IFT_IEEE1394:
2188 	case IFT_L2VLAN:
2189 	case IFT_IEEE80211:
2190 	case IFT_INFINIBAND:
2191 	case IFT_BRIDGE:
2192 	case IFT_PROPVIRTUAL:
2193 		return (1);
2194 	default:
2195 		return (0);
2196 	}
2197 }
2198 
2199 /*
2200  * Add pernament ND6 link-layer record for given
2201  * interface address.
2202  *
2203  * Very similar to IPv4 arp_ifinit(), but:
2204  * 1) IPv6 DAD is performed in different place
2205  * 2) It is called by IPv6 protocol stack in contrast to
2206  * arp_ifinit() which is typically called in SIOCSIFADDR
2207  * driver ioctl handler.
2208  *
2209  */
2210 int
2211 nd6_add_ifa_lle(struct in6_ifaddr *ia)
2212 {
2213 	struct ifnet *ifp;
2214 	struct llentry *ln, *ln_tmp;
2215 	struct sockaddr *dst;
2216 
2217 	ifp = ia->ia_ifa.ifa_ifp;
2218 	if (nd6_need_cache(ifp) == 0)
2219 		return (0);
2220 
2221 	ia->ia_ifa.ifa_rtrequest = nd6_rtrequest;
2222 	dst = (struct sockaddr *)&ia->ia_addr;
2223 	ln = lltable_alloc_entry(LLTABLE6(ifp), LLE_IFADDR, dst);
2224 	if (ln == NULL)
2225 		return (ENOBUFS);
2226 
2227 	IF_AFDATA_WLOCK(ifp);
2228 	LLE_WLOCK(ln);
2229 	/* Unlink any entry if exists */
2230 	ln_tmp = lla_lookup(LLTABLE6(ifp), LLE_EXCLUSIVE, dst);
2231 	if (ln_tmp != NULL)
2232 		lltable_unlink_entry(LLTABLE6(ifp), ln_tmp);
2233 	lltable_link_entry(LLTABLE6(ifp), ln);
2234 	IF_AFDATA_WUNLOCK(ifp);
2235 
2236 	if (ln_tmp != NULL)
2237 		EVENTHANDLER_INVOKE(lle_event, ln_tmp, LLENTRY_EXPIRED);
2238 	EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
2239 
2240 	LLE_WUNLOCK(ln);
2241 	if (ln_tmp != NULL)
2242 		llentry_free(ln_tmp);
2243 
2244 	return (0);
2245 }
2246 
2247 /*
2248  * Removes ALL lle records for interface address prefix.
2249  * XXXME: That's probably not we really want to do, we need
2250  * to remove address record only and keep other records
2251  * until we determine if given prefix is really going
2252  * to be removed.
2253  */
2254 void
2255 nd6_rem_ifa_lle(struct in6_ifaddr *ia)
2256 {
2257 	struct sockaddr_in6 mask, addr;
2258 	struct ifnet *ifp;
2259 
2260 	ifp = ia->ia_ifa.ifa_ifp;
2261 	memcpy(&addr, &ia->ia_addr, sizeof(ia->ia_addr));
2262 	memcpy(&mask, &ia->ia_prefixmask, sizeof(ia->ia_prefixmask));
2263 	lltable_prefix_free(AF_INET6, (struct sockaddr *)&addr,
2264 	            (struct sockaddr *)&mask, LLE_STATIC);
2265 }
2266 
2267 /*
2268  * the callers of this function need to be re-worked to drop
2269  * the lle lock, drop here for now
2270  */
2271 int
2272 nd6_storelladdr(struct ifnet *ifp, struct mbuf *m,
2273     const struct sockaddr *dst, u_char *desten, uint32_t *pflags)
2274 {
2275 	struct llentry *ln;
2276 
2277 	if (pflags != NULL)
2278 		*pflags = 0;
2279 	IF_AFDATA_UNLOCK_ASSERT(ifp);
2280 	if (m != NULL && m->m_flags & M_MCAST) {
2281 		switch (ifp->if_type) {
2282 		case IFT_ETHER:
2283 		case IFT_FDDI:
2284 		case IFT_L2VLAN:
2285 		case IFT_IEEE80211:
2286 		case IFT_BRIDGE:
2287 		case IFT_ISO88025:
2288 			ETHER_MAP_IPV6_MULTICAST(&SIN6(dst)->sin6_addr,
2289 						 desten);
2290 			return (0);
2291 		default:
2292 			m_freem(m);
2293 			return (EAFNOSUPPORT);
2294 		}
2295 	}
2296 
2297 
2298 	/*
2299 	 * the entry should have been created in nd6_store_lladdr
2300 	 */
2301 	IF_AFDATA_RLOCK(ifp);
2302 	ln = lla_lookup(LLTABLE6(ifp), 0, dst);
2303 	IF_AFDATA_RUNLOCK(ifp);
2304 	if ((ln == NULL) || !(ln->la_flags & LLE_VALID)) {
2305 		if (ln != NULL)
2306 			LLE_RUNLOCK(ln);
2307 		/* this could happen, if we could not allocate memory */
2308 		m_freem(m);
2309 		return (1);
2310 	}
2311 
2312 	bcopy(&ln->ll_addr, desten, ifp->if_addrlen);
2313 	if (pflags != NULL)
2314 		*pflags = ln->la_flags;
2315 	LLE_RUNLOCK(ln);
2316 	/*
2317 	 * A *small* use after free race exists here
2318 	 */
2319 	return (0);
2320 }
2321 
2322 static void
2323 clear_llinfo_pqueue(struct llentry *ln)
2324 {
2325 	struct mbuf *m_hold, *m_hold_next;
2326 
2327 	for (m_hold = ln->la_hold; m_hold; m_hold = m_hold_next) {
2328 		m_hold_next = m_hold->m_nextpkt;
2329 		m_freem(m_hold);
2330 	}
2331 
2332 	ln->la_hold = NULL;
2333 	return;
2334 }
2335 
2336 static int nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS);
2337 static int nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS);
2338 #ifdef SYSCTL_DECL
2339 SYSCTL_DECL(_net_inet6_icmp6);
2340 #endif
2341 SYSCTL_NODE(_net_inet6_icmp6, ICMPV6CTL_ND6_DRLIST, nd6_drlist,
2342 	CTLFLAG_RD, nd6_sysctl_drlist, "");
2343 SYSCTL_NODE(_net_inet6_icmp6, ICMPV6CTL_ND6_PRLIST, nd6_prlist,
2344 	CTLFLAG_RD, nd6_sysctl_prlist, "");
2345 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_MAXQLEN, nd6_maxqueuelen,
2346 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_maxqueuelen), 1, "");
2347 SYSCTL_INT(_net_inet6_icmp6, OID_AUTO, nd6_gctimer,
2348 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_gctimer), (60 * 60 * 24), "");
2349 
2350 static int
2351 nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS)
2352 {
2353 	struct in6_defrouter d;
2354 	struct nd_defrouter *dr;
2355 	int error;
2356 
2357 	if (req->newptr)
2358 		return (EPERM);
2359 
2360 	bzero(&d, sizeof(d));
2361 	d.rtaddr.sin6_family = AF_INET6;
2362 	d.rtaddr.sin6_len = sizeof(d.rtaddr);
2363 
2364 	/*
2365 	 * XXX locking
2366 	 */
2367 	TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
2368 		d.rtaddr.sin6_addr = dr->rtaddr;
2369 		error = sa6_recoverscope(&d.rtaddr);
2370 		if (error != 0)
2371 			return (error);
2372 		d.flags = dr->flags;
2373 		d.rtlifetime = dr->rtlifetime;
2374 		d.expire = dr->expire + (time_second - time_uptime);
2375 		d.if_index = dr->ifp->if_index;
2376 		error = SYSCTL_OUT(req, &d, sizeof(d));
2377 		if (error != 0)
2378 			return (error);
2379 	}
2380 	return (0);
2381 }
2382 
2383 static int
2384 nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS)
2385 {
2386 	struct in6_prefix p;
2387 	struct sockaddr_in6 s6;
2388 	struct nd_prefix *pr;
2389 	struct nd_pfxrouter *pfr;
2390 	time_t maxexpire;
2391 	int error;
2392 	char ip6buf[INET6_ADDRSTRLEN];
2393 
2394 	if (req->newptr)
2395 		return (EPERM);
2396 
2397 	bzero(&p, sizeof(p));
2398 	p.origin = PR_ORIG_RA;
2399 	bzero(&s6, sizeof(s6));
2400 	s6.sin6_family = AF_INET6;
2401 	s6.sin6_len = sizeof(s6);
2402 
2403 	/*
2404 	 * XXX locking
2405 	 */
2406 	LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
2407 		p.prefix = pr->ndpr_prefix;
2408 		if (sa6_recoverscope(&p.prefix)) {
2409 			log(LOG_ERR, "scope error in prefix list (%s)\n",
2410 			    ip6_sprintf(ip6buf, &p.prefix.sin6_addr));
2411 			/* XXX: press on... */
2412 		}
2413 		p.raflags = pr->ndpr_raf;
2414 		p.prefixlen = pr->ndpr_plen;
2415 		p.vltime = pr->ndpr_vltime;
2416 		p.pltime = pr->ndpr_pltime;
2417 		p.if_index = pr->ndpr_ifp->if_index;
2418 		if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME)
2419 			p.expire = 0;
2420 		else {
2421 			/* XXX: we assume time_t is signed. */
2422 			maxexpire = (-1) &
2423 			    ~((time_t)1 << ((sizeof(maxexpire) * 8) - 1));
2424 			if (pr->ndpr_vltime < maxexpire - pr->ndpr_lastupdate)
2425 				p.expire = pr->ndpr_lastupdate +
2426 				    pr->ndpr_vltime +
2427 				    (time_second - time_uptime);
2428 			else
2429 				p.expire = maxexpire;
2430 		}
2431 		p.refcnt = pr->ndpr_refcnt;
2432 		p.flags = pr->ndpr_stateflags;
2433 		p.advrtrs = 0;
2434 		LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry)
2435 			p.advrtrs++;
2436 		error = SYSCTL_OUT(req, &p, sizeof(p));
2437 		if (error != 0)
2438 			return (error);
2439 		LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) {
2440 			s6.sin6_addr = pfr->router->rtaddr;
2441 			if (sa6_recoverscope(&s6))
2442 				log(LOG_ERR,
2443 				    "scope error in prefix list (%s)\n",
2444 				    ip6_sprintf(ip6buf, &pfr->router->rtaddr));
2445 			error = SYSCTL_OUT(req, &s6, sizeof(s6));
2446 			if (error != 0)
2447 				return (error);
2448 		}
2449 	}
2450 	return (0);
2451 }
2452