xref: /freebsd/sys/netinet6/nd6.c (revision c1eb4109f3b1d90a9c1538179ea6a52a191899b2)
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_drlist *drl = (struct in6_drlist *)data;
1348 	struct in6_oprlist *oprl = (struct in6_oprlist *)data;
1349 	struct in6_ndireq *ndi = (struct in6_ndireq *)data;
1350 	struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data;
1351 	struct in6_ndifreq *ndif = (struct in6_ndifreq *)data;
1352 	struct nd_defrouter *dr;
1353 	struct nd_prefix *pr;
1354 	int i = 0, error = 0;
1355 
1356 	if (ifp->if_afdata[AF_INET6] == NULL)
1357 		return (EPFNOSUPPORT);
1358 	switch (cmd) {
1359 	case SIOCGDRLST_IN6:
1360 		/*
1361 		 * obsolete API, use sysctl under net.inet6.icmp6
1362 		 */
1363 		bzero(drl, sizeof(*drl));
1364 		TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
1365 			if (i >= DRLSTSIZ)
1366 				break;
1367 			drl->defrouter[i].rtaddr = dr->rtaddr;
1368 			in6_clearscope(&drl->defrouter[i].rtaddr);
1369 
1370 			drl->defrouter[i].flags = dr->flags;
1371 			drl->defrouter[i].rtlifetime = dr->rtlifetime;
1372 			drl->defrouter[i].expire = dr->expire +
1373 			    (time_second - time_uptime);
1374 			drl->defrouter[i].if_index = dr->ifp->if_index;
1375 			i++;
1376 		}
1377 		break;
1378 	case SIOCGPRLST_IN6:
1379 		/*
1380 		 * obsolete API, use sysctl under net.inet6.icmp6
1381 		 *
1382 		 * XXX the structure in6_prlist was changed in backward-
1383 		 * incompatible manner.  in6_oprlist is used for SIOCGPRLST_IN6,
1384 		 * in6_prlist is used for nd6_sysctl() - fill_prlist().
1385 		 */
1386 		/*
1387 		 * XXX meaning of fields, especialy "raflags", is very
1388 		 * differnet between RA prefix list and RR/static prefix list.
1389 		 * how about separating ioctls into two?
1390 		 */
1391 		bzero(oprl, sizeof(*oprl));
1392 		LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
1393 			struct nd_pfxrouter *pfr;
1394 			int j;
1395 
1396 			if (i >= PRLSTSIZ)
1397 				break;
1398 			oprl->prefix[i].prefix = pr->ndpr_prefix.sin6_addr;
1399 			oprl->prefix[i].raflags = pr->ndpr_raf;
1400 			oprl->prefix[i].prefixlen = pr->ndpr_plen;
1401 			oprl->prefix[i].vltime = pr->ndpr_vltime;
1402 			oprl->prefix[i].pltime = pr->ndpr_pltime;
1403 			oprl->prefix[i].if_index = pr->ndpr_ifp->if_index;
1404 			if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME)
1405 				oprl->prefix[i].expire = 0;
1406 			else {
1407 				time_t maxexpire;
1408 
1409 				/* XXX: we assume time_t is signed. */
1410 				maxexpire = (-1) &
1411 				    ~((time_t)1 <<
1412 				    ((sizeof(maxexpire) * 8) - 1));
1413 				if (pr->ndpr_vltime <
1414 				    maxexpire - pr->ndpr_lastupdate) {
1415 					oprl->prefix[i].expire =
1416 					    pr->ndpr_lastupdate +
1417 					    pr->ndpr_vltime +
1418 					    (time_second - time_uptime);
1419 				} else
1420 					oprl->prefix[i].expire = maxexpire;
1421 			}
1422 
1423 			j = 0;
1424 			LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) {
1425 				if (j < DRLSTSIZ) {
1426 #define RTRADDR oprl->prefix[i].advrtr[j]
1427 					RTRADDR = pfr->router->rtaddr;
1428 					in6_clearscope(&RTRADDR);
1429 #undef RTRADDR
1430 				}
1431 				j++;
1432 			}
1433 			oprl->prefix[i].advrtrs = j;
1434 			oprl->prefix[i].origin = PR_ORIG_RA;
1435 
1436 			i++;
1437 		}
1438 
1439 		break;
1440 	case OSIOCGIFINFO_IN6:
1441 #define ND	ndi->ndi
1442 		/* XXX: old ndp(8) assumes a positive value for linkmtu. */
1443 		bzero(&ND, sizeof(ND));
1444 		ND.linkmtu = IN6_LINKMTU(ifp);
1445 		ND.maxmtu = ND_IFINFO(ifp)->maxmtu;
1446 		ND.basereachable = ND_IFINFO(ifp)->basereachable;
1447 		ND.reachable = ND_IFINFO(ifp)->reachable;
1448 		ND.retrans = ND_IFINFO(ifp)->retrans;
1449 		ND.flags = ND_IFINFO(ifp)->flags;
1450 		ND.recalctm = ND_IFINFO(ifp)->recalctm;
1451 		ND.chlim = ND_IFINFO(ifp)->chlim;
1452 		break;
1453 	case SIOCGIFINFO_IN6:
1454 		ND = *ND_IFINFO(ifp);
1455 		break;
1456 	case SIOCSIFINFO_IN6:
1457 		/*
1458 		 * used to change host variables from userland.
1459 		 * intented for a use on router to reflect RA configurations.
1460 		 */
1461 		/* 0 means 'unspecified' */
1462 		if (ND.linkmtu != 0) {
1463 			if (ND.linkmtu < IPV6_MMTU ||
1464 			    ND.linkmtu > IN6_LINKMTU(ifp)) {
1465 				error = EINVAL;
1466 				break;
1467 			}
1468 			ND_IFINFO(ifp)->linkmtu = ND.linkmtu;
1469 		}
1470 
1471 		if (ND.basereachable != 0) {
1472 			int obasereachable = ND_IFINFO(ifp)->basereachable;
1473 
1474 			ND_IFINFO(ifp)->basereachable = ND.basereachable;
1475 			if (ND.basereachable != obasereachable)
1476 				ND_IFINFO(ifp)->reachable =
1477 				    ND_COMPUTE_RTIME(ND.basereachable);
1478 		}
1479 		if (ND.retrans != 0)
1480 			ND_IFINFO(ifp)->retrans = ND.retrans;
1481 		if (ND.chlim != 0)
1482 			ND_IFINFO(ifp)->chlim = ND.chlim;
1483 		/* FALLTHROUGH */
1484 	case SIOCSIFINFO_FLAGS:
1485 	{
1486 		struct ifaddr *ifa;
1487 		struct in6_ifaddr *ia;
1488 
1489 		if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
1490 		    !(ND.flags & ND6_IFF_IFDISABLED)) {
1491 			/* ifdisabled 1->0 transision */
1492 
1493 			/*
1494 			 * If the interface is marked as ND6_IFF_IFDISABLED and
1495 			 * has an link-local address with IN6_IFF_DUPLICATED,
1496 			 * do not clear ND6_IFF_IFDISABLED.
1497 			 * See RFC 4862, Section 5.4.5.
1498 			 */
1499 			int duplicated_linklocal = 0;
1500 
1501 			IF_ADDR_RLOCK(ifp);
1502 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1503 				if (ifa->ifa_addr->sa_family != AF_INET6)
1504 					continue;
1505 				ia = (struct in6_ifaddr *)ifa;
1506 				if ((ia->ia6_flags & IN6_IFF_DUPLICATED) &&
1507 				    IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia))) {
1508 					duplicated_linklocal = 1;
1509 					break;
1510 				}
1511 			}
1512 			IF_ADDR_RUNLOCK(ifp);
1513 
1514 			if (duplicated_linklocal) {
1515 				ND.flags |= ND6_IFF_IFDISABLED;
1516 				log(LOG_ERR, "Cannot enable an interface"
1517 				    " with a link-local address marked"
1518 				    " duplicate.\n");
1519 			} else {
1520 				ND_IFINFO(ifp)->flags &= ~ND6_IFF_IFDISABLED;
1521 				if (ifp->if_flags & IFF_UP)
1522 					in6_if_up(ifp);
1523 			}
1524 		} else if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
1525 			    (ND.flags & ND6_IFF_IFDISABLED)) {
1526 			/* ifdisabled 0->1 transision */
1527 			/* Mark all IPv6 address as tentative. */
1528 
1529 			ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
1530 			IF_ADDR_RLOCK(ifp);
1531 			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1532 				if (ifa->ifa_addr->sa_family != AF_INET6)
1533 					continue;
1534 				ia = (struct in6_ifaddr *)ifa;
1535 				ia->ia6_flags |= IN6_IFF_TENTATIVE;
1536 			}
1537 			IF_ADDR_RUNLOCK(ifp);
1538 		}
1539 
1540 		if (ND.flags & ND6_IFF_AUTO_LINKLOCAL) {
1541 			if (!(ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL)) {
1542 				/* auto_linklocal 0->1 transision */
1543 
1544 				/* If no link-local address on ifp, configure */
1545 				ND_IFINFO(ifp)->flags |= ND6_IFF_AUTO_LINKLOCAL;
1546 				in6_ifattach(ifp, NULL);
1547 			} else if (!(ND.flags & ND6_IFF_IFDISABLED) &&
1548 			    ifp->if_flags & IFF_UP) {
1549 				/*
1550 				 * When the IF already has
1551 				 * ND6_IFF_AUTO_LINKLOCAL, no link-local
1552 				 * address is assigned, and IFF_UP, try to
1553 				 * assign one.
1554 				 */
1555 				int haslinklocal = 0;
1556 
1557 				IF_ADDR_RLOCK(ifp);
1558 				TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1559 					if (ifa->ifa_addr->sa_family != AF_INET6)
1560 						continue;
1561 					ia = (struct in6_ifaddr *)ifa;
1562 					if (IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia))) {
1563 						haslinklocal = 1;
1564 						break;
1565 					}
1566 				}
1567 				IF_ADDR_RUNLOCK(ifp);
1568 				if (!haslinklocal)
1569 					in6_ifattach(ifp, NULL);
1570 			}
1571 		}
1572 	}
1573 		ND_IFINFO(ifp)->flags = ND.flags;
1574 		break;
1575 #undef ND
1576 	case SIOCSNDFLUSH_IN6:	/* XXX: the ioctl name is confusing... */
1577 		/* sync kernel routing table with the default router list */
1578 		defrouter_reset();
1579 		defrouter_select();
1580 		break;
1581 	case SIOCSPFXFLUSH_IN6:
1582 	{
1583 		/* flush all the prefix advertised by routers */
1584 		struct nd_prefix *pr, *next;
1585 
1586 		LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, next) {
1587 			struct in6_ifaddr *ia, *ia_next;
1588 
1589 			if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1590 				continue; /* XXX */
1591 
1592 			/* do we really have to remove addresses as well? */
1593 			/* XXXRW: in6_ifaddrhead locking. */
1594 			TAILQ_FOREACH_SAFE(ia, &V_in6_ifaddrhead, ia_link,
1595 			    ia_next) {
1596 				if ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1597 					continue;
1598 
1599 				if (ia->ia6_ndpr == pr)
1600 					in6_purgeaddr(&ia->ia_ifa);
1601 			}
1602 			prelist_remove(pr);
1603 		}
1604 		break;
1605 	}
1606 	case SIOCSRTRFLUSH_IN6:
1607 	{
1608 		/* flush all the default routers */
1609 		struct nd_defrouter *dr, *next;
1610 
1611 		defrouter_reset();
1612 		TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, next) {
1613 			defrtrlist_del(dr);
1614 		}
1615 		defrouter_select();
1616 		break;
1617 	}
1618 	case SIOCGNBRINFO_IN6:
1619 	{
1620 		struct llentry *ln;
1621 		struct in6_addr nb_addr = nbi->addr; /* make local for safety */
1622 
1623 		if ((error = in6_setscope(&nb_addr, ifp, NULL)) != 0)
1624 			return (error);
1625 
1626 		IF_AFDATA_RLOCK(ifp);
1627 		ln = nd6_lookup(&nb_addr, 0, ifp);
1628 		IF_AFDATA_RUNLOCK(ifp);
1629 
1630 		if (ln == NULL) {
1631 			error = EINVAL;
1632 			break;
1633 		}
1634 		nbi->state = ln->ln_state;
1635 		nbi->asked = ln->la_asked;
1636 		nbi->isrouter = ln->ln_router;
1637 		if (ln->la_expire == 0)
1638 			nbi->expire = 0;
1639 		else
1640 			nbi->expire = ln->la_expire +
1641 			    (time_second - time_uptime);
1642 		LLE_RUNLOCK(ln);
1643 		break;
1644 	}
1645 	case SIOCGDEFIFACE_IN6:	/* XXX: should be implemented as a sysctl? */
1646 		ndif->ifindex = V_nd6_defifindex;
1647 		break;
1648 	case SIOCSDEFIFACE_IN6:	/* XXX: should be implemented as a sysctl? */
1649 		return (nd6_setdefaultiface(ndif->ifindex));
1650 	}
1651 	return (error);
1652 }
1653 
1654 /*
1655  * Create neighbor cache entry and cache link-layer address,
1656  * on reception of inbound ND6 packets.  (RS/RA/NS/redirect)
1657  *
1658  * type - ICMP6 type
1659  * code - type dependent information
1660  *
1661  * XXXXX
1662  *  The caller of this function already acquired the ndp
1663  *  cache table lock because the cache entry is returned.
1664  */
1665 struct llentry *
1666 nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr,
1667     int lladdrlen, int type, int code)
1668 {
1669 	struct llentry *ln = NULL, *ln_tmp;
1670 	int is_newentry;
1671 	int do_update;
1672 	int olladdr;
1673 	int llchange;
1674 	int flags;
1675 	int newstate = 0;
1676 	uint16_t router = 0;
1677 	struct sockaddr_in6 sin6;
1678 	struct mbuf *chain = NULL;
1679 	int static_route = 0;
1680 
1681 	IF_AFDATA_UNLOCK_ASSERT(ifp);
1682 
1683 	KASSERT(ifp != NULL, ("%s: ifp == NULL", __func__));
1684 	KASSERT(from != NULL, ("%s: from == NULL", __func__));
1685 
1686 	/* nothing must be updated for unspecified address */
1687 	if (IN6_IS_ADDR_UNSPECIFIED(from))
1688 		return NULL;
1689 
1690 	/*
1691 	 * Validation about ifp->if_addrlen and lladdrlen must be done in
1692 	 * the caller.
1693 	 *
1694 	 * XXX If the link does not have link-layer adderss, what should
1695 	 * we do? (ifp->if_addrlen == 0)
1696 	 * Spec says nothing in sections for RA, RS and NA.  There's small
1697 	 * description on it in NS section (RFC 2461 7.2.3).
1698 	 */
1699 	flags = lladdr ? ND6_EXCLUSIVE : 0;
1700 	IF_AFDATA_RLOCK(ifp);
1701 	ln = nd6_lookup(from, flags, ifp);
1702 	IF_AFDATA_RUNLOCK(ifp);
1703 	is_newentry = 0;
1704 	if (ln == NULL) {
1705 		flags |= ND6_EXCLUSIVE;
1706 		ln = nd6_alloc(from, 0, ifp);
1707 		if (ln == NULL)
1708 			return (NULL);
1709 		IF_AFDATA_WLOCK(ifp);
1710 		LLE_WLOCK(ln);
1711 		/* Prefer any existing lle over newly-created one */
1712 		ln_tmp = nd6_lookup(from, ND6_EXCLUSIVE, ifp);
1713 		if (ln_tmp == NULL)
1714 			lltable_link_entry(LLTABLE6(ifp), ln);
1715 		IF_AFDATA_WUNLOCK(ifp);
1716 		if (ln_tmp == NULL)
1717 			/* No existing lle, mark as new entry */
1718 			is_newentry = 1;
1719 		else {
1720 			lltable_free_entry(LLTABLE6(ifp), ln);
1721 			ln = ln_tmp;
1722 			ln_tmp = NULL;
1723 		}
1724 	}
1725 	/* do nothing if static ndp is set */
1726 	if ((ln->la_flags & LLE_STATIC)) {
1727 			static_route = 1;
1728 			goto done;
1729 	}
1730 
1731 	olladdr = (ln->la_flags & LLE_VALID) ? 1 : 0;
1732 	if (olladdr && lladdr) {
1733 		llchange = bcmp(lladdr, &ln->ll_addr,
1734 		    ifp->if_addrlen);
1735 	} else
1736 		llchange = 0;
1737 
1738 	/*
1739 	 * newentry olladdr  lladdr  llchange	(*=record)
1740 	 *	0	n	n	--	(1)
1741 	 *	0	y	n	--	(2)
1742 	 *	0	n	y	--	(3) * STALE
1743 	 *	0	y	y	n	(4) *
1744 	 *	0	y	y	y	(5) * STALE
1745 	 *	1	--	n	--	(6)   NOSTATE(= PASSIVE)
1746 	 *	1	--	y	--	(7) * STALE
1747 	 */
1748 
1749 	if (lladdr) {		/* (3-5) and (7) */
1750 		/*
1751 		 * Record source link-layer address
1752 		 * XXX is it dependent to ifp->if_type?
1753 		 */
1754 		bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen);
1755 		ln->la_flags |= LLE_VALID;
1756 		EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
1757 	}
1758 
1759 	if (!is_newentry) {
1760 		if ((!olladdr && lladdr != NULL) ||	/* (3) */
1761 		    (olladdr && lladdr != NULL && llchange)) {	/* (5) */
1762 			do_update = 1;
1763 			newstate = ND6_LLINFO_STALE;
1764 		} else					/* (1-2,4) */
1765 			do_update = 0;
1766 	} else {
1767 		do_update = 1;
1768 		if (lladdr == NULL)			/* (6) */
1769 			newstate = ND6_LLINFO_NOSTATE;
1770 		else					/* (7) */
1771 			newstate = ND6_LLINFO_STALE;
1772 	}
1773 
1774 	if (do_update) {
1775 		/*
1776 		 * Update the state of the neighbor cache.
1777 		 */
1778 		ln->ln_state = newstate;
1779 
1780 		if (ln->ln_state == ND6_LLINFO_STALE) {
1781 			if (ln->la_hold != NULL)
1782 				nd6_grab_holdchain(ln, &chain, &sin6);
1783 		} else if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
1784 			/* probe right away */
1785 			nd6_llinfo_settimer_locked((void *)ln, 0);
1786 		}
1787 	}
1788 
1789 	/*
1790 	 * ICMP6 type dependent behavior.
1791 	 *
1792 	 * NS: clear IsRouter if new entry
1793 	 * RS: clear IsRouter
1794 	 * RA: set IsRouter if there's lladdr
1795 	 * redir: clear IsRouter if new entry
1796 	 *
1797 	 * RA case, (1):
1798 	 * The spec says that we must set IsRouter in the following cases:
1799 	 * - If lladdr exist, set IsRouter.  This means (1-5).
1800 	 * - If it is old entry (!newentry), set IsRouter.  This means (7).
1801 	 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
1802 	 * A quetion arises for (1) case.  (1) case has no lladdr in the
1803 	 * neighbor cache, this is similar to (6).
1804 	 * This case is rare but we figured that we MUST NOT set IsRouter.
1805 	 *
1806 	 * newentry olladdr  lladdr  llchange	    NS  RS  RA	redir
1807 	 *							D R
1808 	 *	0	n	n	--	(1)	c   ?     s
1809 	 *	0	y	n	--	(2)	c   s     s
1810 	 *	0	n	y	--	(3)	c   s     s
1811 	 *	0	y	y	n	(4)	c   s     s
1812 	 *	0	y	y	y	(5)	c   s     s
1813 	 *	1	--	n	--	(6) c	c	c s
1814 	 *	1	--	y	--	(7) c	c   s	c s
1815 	 *
1816 	 *					(c=clear s=set)
1817 	 */
1818 	switch (type & 0xff) {
1819 	case ND_NEIGHBOR_SOLICIT:
1820 		/*
1821 		 * New entry must have is_router flag cleared.
1822 		 */
1823 		if (is_newentry)	/* (6-7) */
1824 			ln->ln_router = 0;
1825 		break;
1826 	case ND_REDIRECT:
1827 		/*
1828 		 * If the icmp is a redirect to a better router, always set the
1829 		 * is_router flag.  Otherwise, if the entry is newly created,
1830 		 * clear the flag.  [RFC 2461, sec 8.3]
1831 		 */
1832 		if (code == ND_REDIRECT_ROUTER)
1833 			ln->ln_router = 1;
1834 		else if (is_newentry) /* (6-7) */
1835 			ln->ln_router = 0;
1836 		break;
1837 	case ND_ROUTER_SOLICIT:
1838 		/*
1839 		 * is_router flag must always be cleared.
1840 		 */
1841 		ln->ln_router = 0;
1842 		break;
1843 	case ND_ROUTER_ADVERT:
1844 		/*
1845 		 * Mark an entry with lladdr as a router.
1846 		 */
1847 		if ((!is_newentry && (olladdr || lladdr)) ||	/* (2-5) */
1848 		    (is_newentry && lladdr)) {			/* (7) */
1849 			ln->ln_router = 1;
1850 		}
1851 		break;
1852 	}
1853 
1854 	if (ln != NULL) {
1855 		static_route = (ln->la_flags & LLE_STATIC);
1856 		router = ln->ln_router;
1857 
1858 		if (flags & ND6_EXCLUSIVE)
1859 			LLE_WUNLOCK(ln);
1860 		else
1861 			LLE_RUNLOCK(ln);
1862 		if (static_route)
1863 			ln = NULL;
1864 	}
1865 	if (chain != NULL)
1866 		nd6_flush_holdchain(ifp, ifp, chain, &sin6);
1867 
1868 	/*
1869 	 * When the link-layer address of a router changes, select the
1870 	 * best router again.  In particular, when the neighbor entry is newly
1871 	 * created, it might affect the selection policy.
1872 	 * Question: can we restrict the first condition to the "is_newentry"
1873 	 * case?
1874 	 * XXX: when we hear an RA from a new router with the link-layer
1875 	 * address option, defrouter_select() is called twice, since
1876 	 * defrtrlist_update called the function as well.  However, I believe
1877 	 * we can compromise the overhead, since it only happens the first
1878 	 * time.
1879 	 * XXX: although defrouter_select() should not have a bad effect
1880 	 * for those are not autoconfigured hosts, we explicitly avoid such
1881 	 * cases for safety.
1882 	 */
1883 	if (do_update && router &&
1884 	    ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
1885 		/*
1886 		 * guaranteed recursion
1887 		 */
1888 		defrouter_select();
1889 	}
1890 
1891 	return (ln);
1892 done:
1893 	if (ln != NULL) {
1894 		if (flags & ND6_EXCLUSIVE)
1895 			LLE_WUNLOCK(ln);
1896 		else
1897 			LLE_RUNLOCK(ln);
1898 		if (static_route)
1899 			ln = NULL;
1900 	}
1901 	return (ln);
1902 }
1903 
1904 static void
1905 nd6_slowtimo(void *arg)
1906 {
1907 	CURVNET_SET((struct vnet *) arg);
1908 	struct nd_ifinfo *nd6if;
1909 	struct ifnet *ifp;
1910 
1911 	callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
1912 	    nd6_slowtimo, curvnet);
1913 	IFNET_RLOCK_NOSLEEP();
1914 	TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
1915 		if (ifp->if_afdata[AF_INET6] == NULL)
1916 			continue;
1917 		nd6if = ND_IFINFO(ifp);
1918 		if (nd6if->basereachable && /* already initialized */
1919 		    (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
1920 			/*
1921 			 * Since reachable time rarely changes by router
1922 			 * advertisements, we SHOULD insure that a new random
1923 			 * value gets recomputed at least once every few hours.
1924 			 * (RFC 2461, 6.3.4)
1925 			 */
1926 			nd6if->recalctm = V_nd6_recalc_reachtm_interval;
1927 			nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable);
1928 		}
1929 	}
1930 	IFNET_RUNLOCK_NOSLEEP();
1931 	CURVNET_RESTORE();
1932 }
1933 
1934 void
1935 nd6_grab_holdchain(struct llentry *ln, struct mbuf **chain,
1936     struct sockaddr_in6 *sin6)
1937 {
1938 
1939 	LLE_WLOCK_ASSERT(ln);
1940 
1941 	*chain = ln->la_hold;
1942 	ln->la_hold = NULL;
1943 	lltable_fill_sa_entry(ln, (struct sockaddr *)sin6);
1944 
1945 	if (ln->ln_state == ND6_LLINFO_STALE) {
1946 
1947 		/*
1948 		 * The first time we send a packet to a
1949 		 * neighbor whose entry is STALE, we have
1950 		 * to change the state to DELAY and a sets
1951 		 * a timer to expire in DELAY_FIRST_PROBE_TIME
1952 		 * seconds to ensure do neighbor unreachability
1953 		 * detection on expiration.
1954 		 * (RFC 2461 7.3.3)
1955 		 */
1956 		ln->la_asked = 0;
1957 		ln->ln_state = ND6_LLINFO_DELAY;
1958 		nd6_llinfo_settimer_locked(ln, (long)V_nd6_delay * hz);
1959 	}
1960 }
1961 
1962 static int
1963 nd6_output_ifp(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
1964     struct sockaddr_in6 *dst)
1965 {
1966 	int error;
1967 	int ip6len;
1968 	struct ip6_hdr *ip6;
1969 	struct m_tag *mtag;
1970 
1971 #ifdef MAC
1972 	mac_netinet6_nd6_send(ifp, m);
1973 #endif
1974 
1975 	/*
1976 	 * If called from nd6_ns_output() (NS), nd6_na_output() (NA),
1977 	 * icmp6_redirect_output() (REDIRECT) or from rip6_output() (RS, RA
1978 	 * as handled by rtsol and rtadvd), mbufs will be tagged for SeND
1979 	 * to be diverted to user space.  When re-injected into the kernel,
1980 	 * send_output() will directly dispatch them to the outgoing interface.
1981 	 */
1982 	if (send_sendso_input_hook != NULL) {
1983 		mtag = m_tag_find(m, PACKET_TAG_ND_OUTGOING, NULL);
1984 		if (mtag != NULL) {
1985 			ip6 = mtod(m, struct ip6_hdr *);
1986 			ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
1987 			/* Use the SEND socket */
1988 			error = send_sendso_input_hook(m, ifp, SND_OUT,
1989 			    ip6len);
1990 			/* -1 == no app on SEND socket */
1991 			if (error == 0 || error != -1)
1992 			    return (error);
1993 		}
1994 	}
1995 
1996 	m_clrprotoflags(m);	/* Avoid confusing lower layers. */
1997 	IP_PROBE(send, NULL, NULL, mtod(m, struct ip6_hdr *), ifp, NULL,
1998 	    mtod(m, struct ip6_hdr *));
1999 
2000 	if ((ifp->if_flags & IFF_LOOPBACK) == 0)
2001 		origifp = ifp;
2002 
2003 	error = (*ifp->if_output)(origifp, m, (struct sockaddr *)dst, NULL);
2004 	return (error);
2005 }
2006 
2007 /*
2008  * IPv6 packet output - light version.
2009  * Checks if destination LLE exists and is in proper state
2010  * (e.g no modification required). If not true, fall back to
2011  * "heavy" version.
2012  */
2013 int
2014 nd6_output(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
2015     struct sockaddr_in6 *dst, struct rtentry *rt0)
2016 {
2017 	struct llentry *ln = NULL;
2018 
2019 	/* discard the packet if IPv6 operation is disabled on the interface */
2020 	if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED)) {
2021 		m_freem(m);
2022 		return (ENETDOWN); /* better error? */
2023 	}
2024 
2025 	if (IN6_IS_ADDR_MULTICAST(&dst->sin6_addr))
2026 		goto sendpkt;
2027 
2028 	if (nd6_need_cache(ifp) == 0)
2029 		goto sendpkt;
2030 
2031 	IF_AFDATA_RLOCK(ifp);
2032 	ln = nd6_lookup(&dst->sin6_addr, 0, ifp);
2033 	IF_AFDATA_RUNLOCK(ifp);
2034 
2035 	/*
2036 	 * Perform fast path for the following cases:
2037 	 * 1) lle state is REACHABLE
2038 	 * 2) lle state is DELAY (NS message sentNS message sent)
2039 	 *
2040 	 * Every other case involves lle modification, so we handle
2041 	 * them separately.
2042 	 */
2043 	if (ln == NULL || (ln->ln_state != ND6_LLINFO_REACHABLE &&
2044 	    ln->ln_state != ND6_LLINFO_DELAY)) {
2045 		/* Fall back to slow processing path */
2046 		if (ln != NULL)
2047 			LLE_RUNLOCK(ln);
2048 		return (nd6_output_lle(ifp, origifp, m, dst));
2049 	}
2050 
2051 sendpkt:
2052 	if (ln != NULL)
2053 		LLE_RUNLOCK(ln);
2054 
2055 	return (nd6_output_ifp(ifp, origifp, m, dst));
2056 }
2057 
2058 
2059 /*
2060  * Output IPv6 packet - heavy version.
2061  * Function assume that either
2062  * 1) destination LLE does not exist, is invalid or stale, so
2063  *   ND6_EXCLUSIVE lock needs to be acquired
2064  * 2) destination lle is provided (with ND6_EXCLUSIVE lock),
2065  *   in that case packets are queued in &chain.
2066  *
2067  */
2068 static int
2069 nd6_output_lle(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
2070     struct sockaddr_in6 *dst)
2071 {
2072 	struct llentry *lle = NULL, *lle_tmp;
2073 
2074 	KASSERT(m != NULL, ("NULL mbuf, nothing to send"));
2075 	/* discard the packet if IPv6 operation is disabled on the interface */
2076 	if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED)) {
2077 		m_freem(m);
2078 		return (ENETDOWN); /* better error? */
2079 	}
2080 
2081 	if (IN6_IS_ADDR_MULTICAST(&dst->sin6_addr))
2082 		goto sendpkt;
2083 
2084 	if (nd6_need_cache(ifp) == 0)
2085 		goto sendpkt;
2086 
2087 	/*
2088 	 * Address resolution or Neighbor Unreachability Detection
2089 	 * for the next hop.
2090 	 * At this point, the destination of the packet must be a unicast
2091 	 * or an anycast address(i.e. not a multicast).
2092 	 */
2093 	if (lle == NULL) {
2094 		IF_AFDATA_RLOCK(ifp);
2095 		lle = nd6_lookup(&dst->sin6_addr, ND6_EXCLUSIVE, ifp);
2096 		IF_AFDATA_RUNLOCK(ifp);
2097 		if ((lle == NULL) && nd6_is_addr_neighbor(dst, ifp))  {
2098 			/*
2099 			 * Since nd6_is_addr_neighbor() internally calls nd6_lookup(),
2100 			 * the condition below is not very efficient.  But we believe
2101 			 * it is tolerable, because this should be a rare case.
2102 			 */
2103 			lle = nd6_alloc(&dst->sin6_addr, 0, ifp);
2104 			if (lle == NULL) {
2105 				char ip6buf[INET6_ADDRSTRLEN];
2106 				log(LOG_DEBUG,
2107 				    "nd6_output: can't allocate llinfo for %s "
2108 				    "(ln=%p)\n",
2109 				    ip6_sprintf(ip6buf, &dst->sin6_addr), lle);
2110 				m_freem(m);
2111 				return (ENOBUFS);
2112 			}
2113 			lle->ln_state = ND6_LLINFO_NOSTATE;
2114 
2115 			IF_AFDATA_WLOCK(ifp);
2116 			LLE_WLOCK(lle);
2117 			/* Prefer any existing entry over newly-created one */
2118 			lle_tmp = nd6_lookup(&dst->sin6_addr, ND6_EXCLUSIVE, ifp);
2119 			if (lle_tmp == NULL)
2120 				lltable_link_entry(LLTABLE6(ifp), lle);
2121 			IF_AFDATA_WUNLOCK(ifp);
2122 			if (lle_tmp != NULL) {
2123 				lltable_free_entry(LLTABLE6(ifp), lle);
2124 				lle = lle_tmp;
2125 				lle_tmp = NULL;
2126 			}
2127 		}
2128 	}
2129 	if (lle == NULL) {
2130 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0 &&
2131 		    !(ND_IFINFO(ifp)->flags & ND6_IFF_PERFORMNUD)) {
2132 			m_freem(m);
2133 			return (ENOBUFS);
2134 		}
2135 		goto sendpkt;	/* send anyway */
2136 	}
2137 
2138 	LLE_WLOCK_ASSERT(lle);
2139 
2140 	/* We don't have to do link-layer address resolution on a p2p link. */
2141 	if ((ifp->if_flags & IFF_POINTOPOINT) != 0 &&
2142 	    lle->ln_state < ND6_LLINFO_REACHABLE) {
2143 		lle->ln_state = ND6_LLINFO_STALE;
2144 		nd6_llinfo_settimer_locked(lle, (long)V_nd6_gctimer * hz);
2145 	}
2146 
2147 	/*
2148 	 * The first time we send a packet to a neighbor whose entry is
2149 	 * STALE, we have to change the state to DELAY and a sets a timer to
2150 	 * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do
2151 	 * neighbor unreachability detection on expiration.
2152 	 * (RFC 2461 7.3.3)
2153 	 */
2154 	if (lle->ln_state == ND6_LLINFO_STALE) {
2155 		lle->la_asked = 0;
2156 		lle->ln_state = ND6_LLINFO_DELAY;
2157 		nd6_llinfo_settimer_locked(lle, (long)V_nd6_delay * hz);
2158 	}
2159 
2160 	/*
2161 	 * If the neighbor cache entry has a state other than INCOMPLETE
2162 	 * (i.e. its link-layer address is already resolved), just
2163 	 * send the packet.
2164 	 */
2165 	if (lle->ln_state > ND6_LLINFO_INCOMPLETE)
2166 		goto sendpkt;
2167 
2168 	/*
2169 	 * There is a neighbor cache entry, but no ethernet address
2170 	 * response yet.  Append this latest packet to the end of the
2171 	 * packet queue in the mbuf, unless the number of the packet
2172 	 * does not exceed nd6_maxqueuelen.  When it exceeds nd6_maxqueuelen,
2173 	 * the oldest packet in the queue will be removed.
2174 	 */
2175 	if (lle->ln_state == ND6_LLINFO_NOSTATE)
2176 		lle->ln_state = ND6_LLINFO_INCOMPLETE;
2177 
2178 	if (lle->la_hold != NULL) {
2179 		struct mbuf *m_hold;
2180 		int i;
2181 
2182 		i = 0;
2183 		for (m_hold = lle->la_hold; m_hold; m_hold = m_hold->m_nextpkt){
2184 			i++;
2185 			if (m_hold->m_nextpkt == NULL) {
2186 				m_hold->m_nextpkt = m;
2187 				break;
2188 			}
2189 		}
2190 		while (i >= V_nd6_maxqueuelen) {
2191 			m_hold = lle->la_hold;
2192 			lle->la_hold = lle->la_hold->m_nextpkt;
2193 			m_freem(m_hold);
2194 			i--;
2195 		}
2196 	} else {
2197 		lle->la_hold = m;
2198 	}
2199 
2200 	/*
2201 	 * If there has been no NS for the neighbor after entering the
2202 	 * INCOMPLETE state, send the first solicitation.
2203 	 */
2204 	if (!ND6_LLINFO_PERMANENT(lle) && lle->la_asked == 0) {
2205 		struct in6_addr src, *psrc;
2206 		lle->la_asked++;
2207 
2208 		nd6_llinfo_settimer_locked(lle,
2209 		    (long)ND_IFINFO(ifp)->retrans * hz / 1000);
2210 		psrc = nd6_llinfo_get_holdsrc(lle, &src);
2211 		LLE_WUNLOCK(lle);
2212 		nd6_ns_output(ifp, psrc, NULL, &dst->sin6_addr, NULL);
2213 	} else {
2214 		/* We did the lookup so we need to do the unlock here. */
2215 		LLE_WUNLOCK(lle);
2216 	}
2217 
2218 	return (0);
2219 
2220   sendpkt:
2221 	if (lle != NULL)
2222 		LLE_WUNLOCK(lle);
2223 
2224 	return (nd6_output_ifp(ifp, origifp, m, dst));
2225 }
2226 
2227 
2228 int
2229 nd6_flush_holdchain(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *chain,
2230     struct sockaddr_in6 *dst)
2231 {
2232 	struct mbuf *m, *m_head;
2233 	struct ifnet *outifp;
2234 	int error = 0;
2235 
2236 	m_head = chain;
2237 	if ((ifp->if_flags & IFF_LOOPBACK) != 0)
2238 		outifp = origifp;
2239 	else
2240 		outifp = ifp;
2241 
2242 	while (m_head) {
2243 		m = m_head;
2244 		m_head = m_head->m_nextpkt;
2245 		error = nd6_output_ifp(ifp, origifp, m, dst);
2246 	}
2247 
2248 	/*
2249 	 * XXX
2250 	 * note that intermediate errors are blindly ignored - but this is
2251 	 * the same convention as used with nd6_output when called by
2252 	 * nd6_cache_lladdr
2253 	 */
2254 	return (error);
2255 }
2256 
2257 
2258 int
2259 nd6_need_cache(struct ifnet *ifp)
2260 {
2261 	/*
2262 	 * XXX: we currently do not make neighbor cache on any interface
2263 	 * other than ARCnet, Ethernet, FDDI and GIF.
2264 	 *
2265 	 * RFC2893 says:
2266 	 * - unidirectional tunnels needs no ND
2267 	 */
2268 	switch (ifp->if_type) {
2269 	case IFT_ARCNET:
2270 	case IFT_ETHER:
2271 	case IFT_FDDI:
2272 	case IFT_IEEE1394:
2273 	case IFT_L2VLAN:
2274 	case IFT_IEEE80211:
2275 	case IFT_INFINIBAND:
2276 	case IFT_BRIDGE:
2277 	case IFT_PROPVIRTUAL:
2278 		return (1);
2279 	default:
2280 		return (0);
2281 	}
2282 }
2283 
2284 /*
2285  * Add pernament ND6 link-layer record for given
2286  * interface address.
2287  *
2288  * Very similar to IPv4 arp_ifinit(), but:
2289  * 1) IPv6 DAD is performed in different place
2290  * 2) It is called by IPv6 protocol stack in contrast to
2291  * arp_ifinit() which is typically called in SIOCSIFADDR
2292  * driver ioctl handler.
2293  *
2294  */
2295 int
2296 nd6_add_ifa_lle(struct in6_ifaddr *ia)
2297 {
2298 	struct ifnet *ifp;
2299 	struct llentry *ln, *ln_tmp;
2300 	struct sockaddr *dst;
2301 
2302 	ifp = ia->ia_ifa.ifa_ifp;
2303 	if (nd6_need_cache(ifp) == 0)
2304 		return (0);
2305 
2306 	ia->ia_ifa.ifa_rtrequest = nd6_rtrequest;
2307 	dst = (struct sockaddr *)&ia->ia_addr;
2308 	ln = lltable_alloc_entry(LLTABLE6(ifp), LLE_IFADDR, dst);
2309 	if (ln == NULL)
2310 		return (ENOBUFS);
2311 
2312 	IF_AFDATA_WLOCK(ifp);
2313 	LLE_WLOCK(ln);
2314 	/* Unlink any entry if exists */
2315 	ln_tmp = lla_lookup(LLTABLE6(ifp), LLE_EXCLUSIVE, dst);
2316 	if (ln_tmp != NULL)
2317 		lltable_unlink_entry(LLTABLE6(ifp), ln_tmp);
2318 	lltable_link_entry(LLTABLE6(ifp), ln);
2319 	IF_AFDATA_WUNLOCK(ifp);
2320 
2321 	if (ln_tmp != NULL)
2322 		EVENTHANDLER_INVOKE(lle_event, ln_tmp, LLENTRY_EXPIRED);
2323 	EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
2324 
2325 	LLE_WUNLOCK(ln);
2326 	if (ln_tmp != NULL)
2327 		llentry_free(ln_tmp);
2328 
2329 	return (0);
2330 }
2331 
2332 /*
2333  * Removes ALL lle records for interface address prefix.
2334  * XXXME: That's probably not we really want to do, we need
2335  * to remove address record only and keep other records
2336  * until we determine if given prefix is really going
2337  * to be removed.
2338  */
2339 void
2340 nd6_rem_ifa_lle(struct in6_ifaddr *ia)
2341 {
2342 	struct sockaddr_in6 mask, addr;
2343 	struct ifnet *ifp;
2344 
2345 	ifp = ia->ia_ifa.ifa_ifp;
2346 	memcpy(&addr, &ia->ia_addr, sizeof(ia->ia_addr));
2347 	memcpy(&mask, &ia->ia_prefixmask, sizeof(ia->ia_prefixmask));
2348 	lltable_prefix_free(AF_INET6, (struct sockaddr *)&addr,
2349 	            (struct sockaddr *)&mask, LLE_STATIC);
2350 }
2351 
2352 /*
2353  * the callers of this function need to be re-worked to drop
2354  * the lle lock, drop here for now
2355  */
2356 int
2357 nd6_storelladdr(struct ifnet *ifp, struct mbuf *m,
2358     const struct sockaddr *dst, u_char *desten, uint32_t *pflags)
2359 {
2360 	struct llentry *ln;
2361 
2362 	if (pflags != NULL)
2363 		*pflags = 0;
2364 	IF_AFDATA_UNLOCK_ASSERT(ifp);
2365 	if (m != NULL && m->m_flags & M_MCAST) {
2366 		switch (ifp->if_type) {
2367 		case IFT_ETHER:
2368 		case IFT_FDDI:
2369 		case IFT_L2VLAN:
2370 		case IFT_IEEE80211:
2371 		case IFT_BRIDGE:
2372 		case IFT_ISO88025:
2373 			ETHER_MAP_IPV6_MULTICAST(&SIN6(dst)->sin6_addr,
2374 						 desten);
2375 			return (0);
2376 		default:
2377 			m_freem(m);
2378 			return (EAFNOSUPPORT);
2379 		}
2380 	}
2381 
2382 
2383 	/*
2384 	 * the entry should have been created in nd6_store_lladdr
2385 	 */
2386 	IF_AFDATA_RLOCK(ifp);
2387 	ln = lla_lookup(LLTABLE6(ifp), 0, dst);
2388 	IF_AFDATA_RUNLOCK(ifp);
2389 	if ((ln == NULL) || !(ln->la_flags & LLE_VALID)) {
2390 		if (ln != NULL)
2391 			LLE_RUNLOCK(ln);
2392 		/* this could happen, if we could not allocate memory */
2393 		m_freem(m);
2394 		return (1);
2395 	}
2396 
2397 	bcopy(&ln->ll_addr, desten, ifp->if_addrlen);
2398 	if (pflags != NULL)
2399 		*pflags = ln->la_flags;
2400 	LLE_RUNLOCK(ln);
2401 	/*
2402 	 * A *small* use after free race exists here
2403 	 */
2404 	return (0);
2405 }
2406 
2407 static void
2408 clear_llinfo_pqueue(struct llentry *ln)
2409 {
2410 	struct mbuf *m_hold, *m_hold_next;
2411 
2412 	for (m_hold = ln->la_hold; m_hold; m_hold = m_hold_next) {
2413 		m_hold_next = m_hold->m_nextpkt;
2414 		m_freem(m_hold);
2415 	}
2416 
2417 	ln->la_hold = NULL;
2418 	return;
2419 }
2420 
2421 static int nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS);
2422 static int nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS);
2423 #ifdef SYSCTL_DECL
2424 SYSCTL_DECL(_net_inet6_icmp6);
2425 #endif
2426 SYSCTL_NODE(_net_inet6_icmp6, ICMPV6CTL_ND6_DRLIST, nd6_drlist,
2427 	CTLFLAG_RD, nd6_sysctl_drlist, "");
2428 SYSCTL_NODE(_net_inet6_icmp6, ICMPV6CTL_ND6_PRLIST, nd6_prlist,
2429 	CTLFLAG_RD, nd6_sysctl_prlist, "");
2430 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_MAXQLEN, nd6_maxqueuelen,
2431 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_maxqueuelen), 1, "");
2432 SYSCTL_INT(_net_inet6_icmp6, OID_AUTO, nd6_gctimer,
2433 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_gctimer), (60 * 60 * 24), "");
2434 
2435 static int
2436 nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS)
2437 {
2438 	struct in6_defrouter d;
2439 	struct nd_defrouter *dr;
2440 	int error;
2441 
2442 	if (req->newptr)
2443 		return (EPERM);
2444 
2445 	bzero(&d, sizeof(d));
2446 	d.rtaddr.sin6_family = AF_INET6;
2447 	d.rtaddr.sin6_len = sizeof(d.rtaddr);
2448 
2449 	/*
2450 	 * XXX locking
2451 	 */
2452 	TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
2453 		d.rtaddr.sin6_addr = dr->rtaddr;
2454 		error = sa6_recoverscope(&d.rtaddr);
2455 		if (error != 0)
2456 			return (error);
2457 		d.flags = dr->flags;
2458 		d.rtlifetime = dr->rtlifetime;
2459 		d.expire = dr->expire + (time_second - time_uptime);
2460 		d.if_index = dr->ifp->if_index;
2461 		error = SYSCTL_OUT(req, &d, sizeof(d));
2462 		if (error != 0)
2463 			return (error);
2464 	}
2465 	return (0);
2466 }
2467 
2468 static int
2469 nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS)
2470 {
2471 	struct in6_prefix p;
2472 	struct sockaddr_in6 s6;
2473 	struct nd_prefix *pr;
2474 	struct nd_pfxrouter *pfr;
2475 	time_t maxexpire;
2476 	int error;
2477 	char ip6buf[INET6_ADDRSTRLEN];
2478 
2479 	if (req->newptr)
2480 		return (EPERM);
2481 
2482 	bzero(&p, sizeof(p));
2483 	p.origin = PR_ORIG_RA;
2484 	bzero(&s6, sizeof(s6));
2485 	s6.sin6_family = AF_INET6;
2486 	s6.sin6_len = sizeof(s6);
2487 
2488 	/*
2489 	 * XXX locking
2490 	 */
2491 	LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
2492 		p.prefix = pr->ndpr_prefix;
2493 		if (sa6_recoverscope(&p.prefix)) {
2494 			log(LOG_ERR, "scope error in prefix list (%s)\n",
2495 			    ip6_sprintf(ip6buf, &p.prefix.sin6_addr));
2496 			/* XXX: press on... */
2497 		}
2498 		p.raflags = pr->ndpr_raf;
2499 		p.prefixlen = pr->ndpr_plen;
2500 		p.vltime = pr->ndpr_vltime;
2501 		p.pltime = pr->ndpr_pltime;
2502 		p.if_index = pr->ndpr_ifp->if_index;
2503 		if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME)
2504 			p.expire = 0;
2505 		else {
2506 			/* XXX: we assume time_t is signed. */
2507 			maxexpire = (-1) &
2508 			    ~((time_t)1 << ((sizeof(maxexpire) * 8) - 1));
2509 			if (pr->ndpr_vltime < maxexpire - pr->ndpr_lastupdate)
2510 				p.expire = pr->ndpr_lastupdate +
2511 				    pr->ndpr_vltime +
2512 				    (time_second - time_uptime);
2513 			else
2514 				p.expire = maxexpire;
2515 		}
2516 		p.refcnt = pr->ndpr_refcnt;
2517 		p.flags = pr->ndpr_stateflags;
2518 		p.advrtrs = 0;
2519 		LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry)
2520 			p.advrtrs++;
2521 		error = SYSCTL_OUT(req, &p, sizeof(p));
2522 		if (error != 0)
2523 			return (error);
2524 		LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) {
2525 			s6.sin6_addr = pfr->router->rtaddr;
2526 			if (sa6_recoverscope(&s6))
2527 				log(LOG_ERR,
2528 				    "scope error in prefix list (%s)\n",
2529 				    ip6_sprintf(ip6buf, &pfr->router->rtaddr));
2530 			error = SYSCTL_OUT(req, &s6, sizeof(s6));
2531 			if (error != 0)
2532 				return (error);
2533 		}
2534 	}
2535 	return (0);
2536 }
2537