xref: /freebsd/sys/netinet6/mld6.c (revision 3b8f08459569bf0faa21473e5cec2491e95c9349)
1 /*-
2  * Copyright (c) 2009 Bruce Simpson.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  * 3. The name of the author may not be used to endorse or promote
13  *    products derived from this software without specific prior written
14  *    permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  *	$KAME: mld6.c,v 1.27 2001/04/04 05:17:30 itojun Exp $
29  */
30 
31 /*-
32  * Copyright (c) 1988 Stephen Deering.
33  * Copyright (c) 1992, 1993
34  *	The Regents of the University of California.  All rights reserved.
35  *
36  * This code is derived from software contributed to Berkeley by
37  * Stephen Deering of Stanford University.
38  *
39  * Redistribution and use in source and binary forms, with or without
40  * modification, are permitted provided that the following conditions
41  * are met:
42  * 1. Redistributions of source code must retain the above copyright
43  *    notice, this list of conditions and the following disclaimer.
44  * 2. Redistributions in binary form must reproduce the above copyright
45  *    notice, this list of conditions and the following disclaimer in the
46  *    documentation and/or other materials provided with the distribution.
47  * 4. Neither the name of the University nor the names of its contributors
48  *    may be used to endorse or promote products derived from this software
49  *    without specific prior written permission.
50  *
51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
61  * SUCH DAMAGE.
62  *
63  *	@(#)igmp.c	8.1 (Berkeley) 7/19/93
64  */
65 
66 #include <sys/cdefs.h>
67 __FBSDID("$FreeBSD$");
68 
69 #include "opt_inet.h"
70 #include "opt_inet6.h"
71 
72 #include <sys/param.h>
73 #include <sys/systm.h>
74 #include <sys/mbuf.h>
75 #include <sys/socket.h>
76 #include <sys/protosw.h>
77 #include <sys/sysctl.h>
78 #include <sys/kernel.h>
79 #include <sys/callout.h>
80 #include <sys/malloc.h>
81 #include <sys/module.h>
82 #include <sys/ktr.h>
83 
84 #include <net/if.h>
85 #include <net/if_var.h>
86 #include <net/route.h>
87 #include <net/vnet.h>
88 
89 #include <netinet/in.h>
90 #include <netinet/in_var.h>
91 #include <netinet6/in6_var.h>
92 #include <netinet/ip6.h>
93 #include <netinet6/ip6_var.h>
94 #include <netinet6/scope6_var.h>
95 #include <netinet/icmp6.h>
96 #include <netinet6/mld6.h>
97 #include <netinet6/mld6_var.h>
98 
99 #include <security/mac/mac_framework.h>
100 
101 #ifndef KTR_MLD
102 #define KTR_MLD KTR_INET6
103 #endif
104 
105 static struct mld_ifinfo *
106 		mli_alloc_locked(struct ifnet *);
107 static void	mli_delete_locked(const struct ifnet *);
108 static void	mld_dispatch_packet(struct mbuf *);
109 static void	mld_dispatch_queue(struct ifqueue *, int);
110 static void	mld_final_leave(struct in6_multi *, struct mld_ifinfo *);
111 static void	mld_fasttimo_vnet(void);
112 static int	mld_handle_state_change(struct in6_multi *,
113 		    struct mld_ifinfo *);
114 static int	mld_initial_join(struct in6_multi *, struct mld_ifinfo *,
115 		    const int);
116 #ifdef KTR
117 static char *	mld_rec_type_to_str(const int);
118 #endif
119 static void	mld_set_version(struct mld_ifinfo *, const int);
120 static void	mld_slowtimo_vnet(void);
121 static int	mld_v1_input_query(struct ifnet *, const struct ip6_hdr *,
122 		    /*const*/ struct mld_hdr *);
123 static int	mld_v1_input_report(struct ifnet *, const struct ip6_hdr *,
124 		    /*const*/ struct mld_hdr *);
125 static void	mld_v1_process_group_timer(struct mld_ifinfo *,
126 		    struct in6_multi *);
127 static void	mld_v1_process_querier_timers(struct mld_ifinfo *);
128 static int	mld_v1_transmit_report(struct in6_multi *, const int);
129 static void	mld_v1_update_group(struct in6_multi *, const int);
130 static void	mld_v2_cancel_link_timers(struct mld_ifinfo *);
131 static void	mld_v2_dispatch_general_query(struct mld_ifinfo *);
132 static struct mbuf *
133 		mld_v2_encap_report(struct ifnet *, struct mbuf *);
134 static int	mld_v2_enqueue_filter_change(struct ifqueue *,
135 		    struct in6_multi *);
136 static int	mld_v2_enqueue_group_record(struct ifqueue *,
137 		    struct in6_multi *, const int, const int, const int,
138 		    const int);
139 static int	mld_v2_input_query(struct ifnet *, const struct ip6_hdr *,
140 		    struct mbuf *, const int, const int);
141 static int	mld_v2_merge_state_changes(struct in6_multi *,
142 		    struct ifqueue *);
143 static void	mld_v2_process_group_timers(struct mld_ifinfo *,
144 		    struct ifqueue *, struct ifqueue *,
145 		    struct in6_multi *, const int);
146 static int	mld_v2_process_group_query(struct in6_multi *,
147 		    struct mld_ifinfo *mli, int, struct mbuf *, const int);
148 static int	sysctl_mld_gsr(SYSCTL_HANDLER_ARGS);
149 static int	sysctl_mld_ifinfo(SYSCTL_HANDLER_ARGS);
150 
151 /*
152  * Normative references: RFC 2710, RFC 3590, RFC 3810.
153  *
154  * Locking:
155  *  * The MLD subsystem lock ends up being system-wide for the moment,
156  *    but could be per-VIMAGE later on.
157  *  * The permitted lock order is: IN6_MULTI_LOCK, MLD_LOCK, IF_ADDR_LOCK.
158  *    Any may be taken independently; if any are held at the same
159  *    time, the above lock order must be followed.
160  *  * IN6_MULTI_LOCK covers in_multi.
161  *  * MLD_LOCK covers per-link state and any global variables in this file.
162  *  * IF_ADDR_LOCK covers if_multiaddrs, which is used for a variety of
163  *    per-link state iterators.
164  *
165  *  XXX LOR PREVENTION
166  *  A special case for IPv6 is the in6_setscope() routine. ip6_output()
167  *  will not accept an ifp; it wants an embedded scope ID, unlike
168  *  ip_output(), which happily takes the ifp given to it. The embedded
169  *  scope ID is only used by MLD to select the outgoing interface.
170  *
171  *  During interface attach and detach, MLD will take MLD_LOCK *after*
172  *  the IF_AFDATA_LOCK.
173  *  As in6_setscope() takes IF_AFDATA_LOCK then SCOPE_LOCK, we can't call
174  *  it with MLD_LOCK held without triggering an LOR. A netisr with indirect
175  *  dispatch could work around this, but we'd rather not do that, as it
176  *  can introduce other races.
177  *
178  *  As such, we exploit the fact that the scope ID is just the interface
179  *  index, and embed it in the IPv6 destination address accordingly.
180  *  This is potentially NOT VALID for MLDv1 reports, as they
181  *  are always sent to the multicast group itself; as MLDv2
182  *  reports are always sent to ff02::16, this is not an issue
183  *  when MLDv2 is in use.
184  *
185  *  This does not however eliminate the LOR when ip6_output() itself
186  *  calls in6_setscope() internally whilst MLD_LOCK is held. This will
187  *  trigger a LOR warning in WITNESS when the ifnet is detached.
188  *
189  *  The right answer is probably to make IF_AFDATA_LOCK an rwlock, given
190  *  how it's used across the network stack. Here we're simply exploiting
191  *  the fact that MLD runs at a similar layer in the stack to scope6.c.
192  *
193  * VIMAGE:
194  *  * Each in6_multi corresponds to an ifp, and each ifp corresponds
195  *    to a vnet in ifp->if_vnet.
196  */
197 static struct mtx		 mld_mtx;
198 static MALLOC_DEFINE(M_MLD, "mld", "mld state");
199 
200 #define	MLD_EMBEDSCOPE(pin6, zoneid)					\
201 	if (IN6_IS_SCOPE_LINKLOCAL(pin6) ||				\
202 	    IN6_IS_ADDR_MC_INTFACELOCAL(pin6))				\
203 		(pin6)->s6_addr16[1] = htons((zoneid) & 0xFFFF)		\
204 
205 /*
206  * VIMAGE-wide globals.
207  */
208 static VNET_DEFINE(struct timeval, mld_gsrdelay) = {10, 0};
209 static VNET_DEFINE(LIST_HEAD(, mld_ifinfo), mli_head);
210 static VNET_DEFINE(int, interface_timers_running6);
211 static VNET_DEFINE(int, state_change_timers_running6);
212 static VNET_DEFINE(int, current_state_timers_running6);
213 
214 #define	V_mld_gsrdelay			VNET(mld_gsrdelay)
215 #define	V_mli_head			VNET(mli_head)
216 #define	V_interface_timers_running6	VNET(interface_timers_running6)
217 #define	V_state_change_timers_running6	VNET(state_change_timers_running6)
218 #define	V_current_state_timers_running6	VNET(current_state_timers_running6)
219 
220 SYSCTL_DECL(_net_inet6);	/* Note: Not in any common header. */
221 
222 SYSCTL_NODE(_net_inet6, OID_AUTO, mld, CTLFLAG_RW, 0,
223     "IPv6 Multicast Listener Discovery");
224 
225 /*
226  * Virtualized sysctls.
227  */
228 SYSCTL_VNET_PROC(_net_inet6_mld, OID_AUTO, gsrdelay,
229     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
230     &VNET_NAME(mld_gsrdelay.tv_sec), 0, sysctl_mld_gsr, "I",
231     "Rate limit for MLDv2 Group-and-Source queries in seconds");
232 
233 /*
234  * Non-virtualized sysctls.
235  */
236 static SYSCTL_NODE(_net_inet6_mld, OID_AUTO, ifinfo,
237     CTLFLAG_RD | CTLFLAG_MPSAFE, sysctl_mld_ifinfo,
238     "Per-interface MLDv2 state");
239 
240 static int	mld_v1enable = 1;
241 SYSCTL_INT(_net_inet6_mld, OID_AUTO, v1enable, CTLFLAG_RW,
242     &mld_v1enable, 0, "Enable fallback to MLDv1");
243 TUNABLE_INT("net.inet6.mld.v1enable", &mld_v1enable);
244 
245 static int	mld_use_allow = 1;
246 SYSCTL_INT(_net_inet6_mld, OID_AUTO, use_allow, CTLFLAG_RW,
247     &mld_use_allow, 0, "Use ALLOW/BLOCK for RFC 4604 SSM joins/leaves");
248 TUNABLE_INT("net.inet6.mld.use_allow", &mld_use_allow);
249 
250 /*
251  * Packed Router Alert option structure declaration.
252  */
253 struct mld_raopt {
254 	struct ip6_hbh		hbh;
255 	struct ip6_opt		pad;
256 	struct ip6_opt_router	ra;
257 } __packed;
258 
259 /*
260  * Router Alert hop-by-hop option header.
261  */
262 static struct mld_raopt mld_ra = {
263 	.hbh = { 0, 0 },
264 	.pad = { .ip6o_type = IP6OPT_PADN, 0 },
265 	.ra = {
266 	    .ip6or_type = IP6OPT_ROUTER_ALERT,
267 	    .ip6or_len = IP6OPT_RTALERT_LEN - 2,
268 	    .ip6or_value[0] = ((IP6OPT_RTALERT_MLD >> 8) & 0xFF),
269 	    .ip6or_value[1] = (IP6OPT_RTALERT_MLD & 0xFF)
270 	}
271 };
272 static struct ip6_pktopts mld_po;
273 
274 static __inline void
275 mld_save_context(struct mbuf *m, struct ifnet *ifp)
276 {
277 
278 #ifdef VIMAGE
279 	m->m_pkthdr.PH_loc.ptr = ifp->if_vnet;
280 #endif /* VIMAGE */
281 	m->m_pkthdr.flowid = ifp->if_index;
282 }
283 
284 static __inline void
285 mld_scrub_context(struct mbuf *m)
286 {
287 
288 	m->m_pkthdr.PH_loc.ptr = NULL;
289 	m->m_pkthdr.flowid = 0;
290 }
291 
292 /*
293  * Restore context from a queued output chain.
294  * Return saved ifindex.
295  *
296  * VIMAGE: The assertion is there to make sure that we
297  * actually called CURVNET_SET() with what's in the mbuf chain.
298  */
299 static __inline uint32_t
300 mld_restore_context(struct mbuf *m)
301 {
302 
303 #if defined(VIMAGE) && defined(INVARIANTS)
304 	KASSERT(curvnet == m->m_pkthdr.PH_loc.ptr,
305 	    ("%s: called when curvnet was not restored", __func__));
306 #endif
307 	return (m->m_pkthdr.flowid);
308 }
309 
310 /*
311  * Retrieve or set threshold between group-source queries in seconds.
312  *
313  * VIMAGE: Assume curvnet set by caller.
314  * SMPng: NOTE: Serialized by MLD lock.
315  */
316 static int
317 sysctl_mld_gsr(SYSCTL_HANDLER_ARGS)
318 {
319 	int error;
320 	int i;
321 
322 	error = sysctl_wire_old_buffer(req, sizeof(int));
323 	if (error)
324 		return (error);
325 
326 	MLD_LOCK();
327 
328 	i = V_mld_gsrdelay.tv_sec;
329 
330 	error = sysctl_handle_int(oidp, &i, 0, req);
331 	if (error || !req->newptr)
332 		goto out_locked;
333 
334 	if (i < -1 || i >= 60) {
335 		error = EINVAL;
336 		goto out_locked;
337 	}
338 
339 	CTR2(KTR_MLD, "change mld_gsrdelay from %d to %d",
340 	     V_mld_gsrdelay.tv_sec, i);
341 	V_mld_gsrdelay.tv_sec = i;
342 
343 out_locked:
344 	MLD_UNLOCK();
345 	return (error);
346 }
347 
348 /*
349  * Expose struct mld_ifinfo to userland, keyed by ifindex.
350  * For use by ifmcstat(8).
351  *
352  * SMPng: NOTE: Does an unlocked ifindex space read.
353  * VIMAGE: Assume curvnet set by caller. The node handler itself
354  * is not directly virtualized.
355  */
356 static int
357 sysctl_mld_ifinfo(SYSCTL_HANDLER_ARGS)
358 {
359 	int			*name;
360 	int			 error;
361 	u_int			 namelen;
362 	struct ifnet		*ifp;
363 	struct mld_ifinfo	*mli;
364 
365 	name = (int *)arg1;
366 	namelen = arg2;
367 
368 	if (req->newptr != NULL)
369 		return (EPERM);
370 
371 	if (namelen != 1)
372 		return (EINVAL);
373 
374 	error = sysctl_wire_old_buffer(req, sizeof(struct mld_ifinfo));
375 	if (error)
376 		return (error);
377 
378 	IN6_MULTI_LOCK();
379 	MLD_LOCK();
380 
381 	if (name[0] <= 0 || name[0] > V_if_index) {
382 		error = ENOENT;
383 		goto out_locked;
384 	}
385 
386 	error = ENOENT;
387 
388 	ifp = ifnet_byindex(name[0]);
389 	if (ifp == NULL)
390 		goto out_locked;
391 
392 	LIST_FOREACH(mli, &V_mli_head, mli_link) {
393 		if (ifp == mli->mli_ifp) {
394 			error = SYSCTL_OUT(req, mli,
395 			    sizeof(struct mld_ifinfo));
396 			break;
397 		}
398 	}
399 
400 out_locked:
401 	MLD_UNLOCK();
402 	IN6_MULTI_UNLOCK();
403 	return (error);
404 }
405 
406 /*
407  * Dispatch an entire queue of pending packet chains.
408  * VIMAGE: Assumes the vnet pointer has been set.
409  */
410 static void
411 mld_dispatch_queue(struct ifqueue *ifq, int limit)
412 {
413 	struct mbuf *m;
414 
415 	for (;;) {
416 		_IF_DEQUEUE(ifq, m);
417 		if (m == NULL)
418 			break;
419 		CTR3(KTR_MLD, "%s: dispatch %p from %p", __func__, ifq, m);
420 		mld_dispatch_packet(m);
421 		if (--limit == 0)
422 			break;
423 	}
424 }
425 
426 /*
427  * Filter outgoing MLD report state by group.
428  *
429  * Reports are ALWAYS suppressed for ALL-HOSTS (ff02::1)
430  * and node-local addresses. However, kernel and socket consumers
431  * always embed the KAME scope ID in the address provided, so strip it
432  * when performing comparison.
433  * Note: This is not the same as the *multicast* scope.
434  *
435  * Return zero if the given group is one for which MLD reports
436  * should be suppressed, or non-zero if reports should be issued.
437  */
438 static __inline int
439 mld_is_addr_reported(const struct in6_addr *addr)
440 {
441 
442 	KASSERT(IN6_IS_ADDR_MULTICAST(addr), ("%s: not multicast", __func__));
443 
444 	if (IPV6_ADDR_MC_SCOPE(addr) == IPV6_ADDR_SCOPE_NODELOCAL)
445 		return (0);
446 
447 	if (IPV6_ADDR_MC_SCOPE(addr) == IPV6_ADDR_SCOPE_LINKLOCAL) {
448 		struct in6_addr tmp = *addr;
449 		in6_clearscope(&tmp);
450 		if (IN6_ARE_ADDR_EQUAL(&tmp, &in6addr_linklocal_allnodes))
451 			return (0);
452 	}
453 
454 	return (1);
455 }
456 
457 /*
458  * Attach MLD when PF_INET6 is attached to an interface.
459  *
460  * SMPng: Normally called with IF_AFDATA_LOCK held.
461  */
462 struct mld_ifinfo *
463 mld_domifattach(struct ifnet *ifp)
464 {
465 	struct mld_ifinfo *mli;
466 
467 	CTR3(KTR_MLD, "%s: called for ifp %p(%s)",
468 	    __func__, ifp, if_name(ifp));
469 
470 	MLD_LOCK();
471 
472 	mli = mli_alloc_locked(ifp);
473 	if (!(ifp->if_flags & IFF_MULTICAST))
474 		mli->mli_flags |= MLIF_SILENT;
475 	if (mld_use_allow)
476 		mli->mli_flags |= MLIF_USEALLOW;
477 
478 	MLD_UNLOCK();
479 
480 	return (mli);
481 }
482 
483 /*
484  * VIMAGE: assume curvnet set by caller.
485  */
486 static struct mld_ifinfo *
487 mli_alloc_locked(/*const*/ struct ifnet *ifp)
488 {
489 	struct mld_ifinfo *mli;
490 
491 	MLD_LOCK_ASSERT();
492 
493 	mli = malloc(sizeof(struct mld_ifinfo), M_MLD, M_NOWAIT|M_ZERO);
494 	if (mli == NULL)
495 		goto out;
496 
497 	mli->mli_ifp = ifp;
498 	mli->mli_version = MLD_VERSION_2;
499 	mli->mli_flags = 0;
500 	mli->mli_rv = MLD_RV_INIT;
501 	mli->mli_qi = MLD_QI_INIT;
502 	mli->mli_qri = MLD_QRI_INIT;
503 	mli->mli_uri = MLD_URI_INIT;
504 
505 	SLIST_INIT(&mli->mli_relinmhead);
506 
507 	/*
508 	 * Responses to general queries are subject to bounds.
509 	 */
510 	IFQ_SET_MAXLEN(&mli->mli_gq, MLD_MAX_RESPONSE_PACKETS);
511 
512 	LIST_INSERT_HEAD(&V_mli_head, mli, mli_link);
513 
514 	CTR2(KTR_MLD, "allocate mld_ifinfo for ifp %p(%s)",
515 	     ifp, if_name(ifp));
516 
517 out:
518 	return (mli);
519 }
520 
521 /*
522  * Hook for ifdetach.
523  *
524  * NOTE: Some finalization tasks need to run before the protocol domain
525  * is detached, but also before the link layer does its cleanup.
526  * Run before link-layer cleanup; cleanup groups, but do not free MLD state.
527  *
528  * SMPng: Caller must hold IN6_MULTI_LOCK().
529  * Must take IF_ADDR_LOCK() to cover if_multiaddrs iterator.
530  * XXX This routine is also bitten by unlocked ifma_protospec access.
531  */
532 void
533 mld_ifdetach(struct ifnet *ifp)
534 {
535 	struct mld_ifinfo	*mli;
536 	struct ifmultiaddr	*ifma;
537 	struct in6_multi	*inm, *tinm;
538 
539 	CTR3(KTR_MLD, "%s: called for ifp %p(%s)", __func__, ifp,
540 	    if_name(ifp));
541 
542 	IN6_MULTI_LOCK_ASSERT();
543 	MLD_LOCK();
544 
545 	mli = MLD_IFINFO(ifp);
546 	if (mli->mli_version == MLD_VERSION_2) {
547 		IF_ADDR_RLOCK(ifp);
548 		TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
549 			if (ifma->ifma_addr->sa_family != AF_INET6 ||
550 			    ifma->ifma_protospec == NULL)
551 				continue;
552 			inm = (struct in6_multi *)ifma->ifma_protospec;
553 			if (inm->in6m_state == MLD_LEAVING_MEMBER) {
554 				SLIST_INSERT_HEAD(&mli->mli_relinmhead,
555 				    inm, in6m_nrele);
556 			}
557 			in6m_clear_recorded(inm);
558 		}
559 		IF_ADDR_RUNLOCK(ifp);
560 		SLIST_FOREACH_SAFE(inm, &mli->mli_relinmhead, in6m_nrele,
561 		    tinm) {
562 			SLIST_REMOVE_HEAD(&mli->mli_relinmhead, in6m_nrele);
563 			in6m_release_locked(inm);
564 		}
565 	}
566 
567 	MLD_UNLOCK();
568 }
569 
570 /*
571  * Hook for domifdetach.
572  * Runs after link-layer cleanup; free MLD state.
573  *
574  * SMPng: Normally called with IF_AFDATA_LOCK held.
575  */
576 void
577 mld_domifdetach(struct ifnet *ifp)
578 {
579 
580 	CTR3(KTR_MLD, "%s: called for ifp %p(%s)",
581 	    __func__, ifp, if_name(ifp));
582 
583 	MLD_LOCK();
584 	mli_delete_locked(ifp);
585 	MLD_UNLOCK();
586 }
587 
588 static void
589 mli_delete_locked(const struct ifnet *ifp)
590 {
591 	struct mld_ifinfo *mli, *tmli;
592 
593 	CTR3(KTR_MLD, "%s: freeing mld_ifinfo for ifp %p(%s)",
594 	    __func__, ifp, if_name(ifp));
595 
596 	MLD_LOCK_ASSERT();
597 
598 	LIST_FOREACH_SAFE(mli, &V_mli_head, mli_link, tmli) {
599 		if (mli->mli_ifp == ifp) {
600 			/*
601 			 * Free deferred General Query responses.
602 			 */
603 			_IF_DRAIN(&mli->mli_gq);
604 
605 			LIST_REMOVE(mli, mli_link);
606 
607 			KASSERT(SLIST_EMPTY(&mli->mli_relinmhead),
608 			    ("%s: there are dangling in_multi references",
609 			    __func__));
610 
611 			free(mli, M_MLD);
612 			return;
613 		}
614 	}
615 #ifdef INVARIANTS
616 	panic("%s: mld_ifinfo not found for ifp %p\n", __func__,  ifp);
617 #endif
618 }
619 
620 /*
621  * Process a received MLDv1 general or address-specific query.
622  * Assumes that the query header has been pulled up to sizeof(mld_hdr).
623  *
624  * NOTE: Can't be fully const correct as we temporarily embed scope ID in
625  * mld_addr. This is OK as we own the mbuf chain.
626  */
627 static int
628 mld_v1_input_query(struct ifnet *ifp, const struct ip6_hdr *ip6,
629     /*const*/ struct mld_hdr *mld)
630 {
631 	struct ifmultiaddr	*ifma;
632 	struct mld_ifinfo	*mli;
633 	struct in6_multi	*inm;
634 	int			 is_general_query;
635 	uint16_t		 timer;
636 #ifdef KTR
637 	char			 ip6tbuf[INET6_ADDRSTRLEN];
638 #endif
639 
640 	is_general_query = 0;
641 
642 	if (!mld_v1enable) {
643 		CTR3(KTR_MLD, "ignore v1 query %s on ifp %p(%s)",
644 		    ip6_sprintf(ip6tbuf, &mld->mld_addr),
645 		    ifp, if_name(ifp));
646 		return (0);
647 	}
648 
649 	/*
650 	 * RFC3810 Section 6.2: MLD queries must originate from
651 	 * a router's link-local address.
652 	 */
653 	if (!IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
654 		CTR3(KTR_MLD, "ignore v1 query src %s on ifp %p(%s)",
655 		    ip6_sprintf(ip6tbuf, &ip6->ip6_src),
656 		    ifp, if_name(ifp));
657 		return (0);
658 	}
659 
660 	/*
661 	 * Do address field validation upfront before we accept
662 	 * the query.
663 	 */
664 	if (IN6_IS_ADDR_UNSPECIFIED(&mld->mld_addr)) {
665 		/*
666 		 * MLDv1 General Query.
667 		 * If this was not sent to the all-nodes group, ignore it.
668 		 */
669 		struct in6_addr		 dst;
670 
671 		dst = ip6->ip6_dst;
672 		in6_clearscope(&dst);
673 		if (!IN6_ARE_ADDR_EQUAL(&dst, &in6addr_linklocal_allnodes))
674 			return (EINVAL);
675 		is_general_query = 1;
676 	} else {
677 		/*
678 		 * Embed scope ID of receiving interface in MLD query for
679 		 * lookup whilst we don't hold other locks.
680 		 */
681 		in6_setscope(&mld->mld_addr, ifp, NULL);
682 	}
683 
684 	IN6_MULTI_LOCK();
685 	MLD_LOCK();
686 
687 	/*
688 	 * Switch to MLDv1 host compatibility mode.
689 	 */
690 	mli = MLD_IFINFO(ifp);
691 	KASSERT(mli != NULL, ("%s: no mld_ifinfo for ifp %p", __func__, ifp));
692 	mld_set_version(mli, MLD_VERSION_1);
693 
694 	timer = (ntohs(mld->mld_maxdelay) * PR_FASTHZ) / MLD_TIMER_SCALE;
695 	if (timer == 0)
696 		timer = 1;
697 
698 	IF_ADDR_RLOCK(ifp);
699 	if (is_general_query) {
700 		/*
701 		 * For each reporting group joined on this
702 		 * interface, kick the report timer.
703 		 */
704 		CTR2(KTR_MLD, "process v1 general query on ifp %p(%s)",
705 		    ifp, if_name(ifp));
706 		TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
707 			if (ifma->ifma_addr->sa_family != AF_INET6 ||
708 			    ifma->ifma_protospec == NULL)
709 				continue;
710 			inm = (struct in6_multi *)ifma->ifma_protospec;
711 			mld_v1_update_group(inm, timer);
712 		}
713 	} else {
714 		/*
715 		 * MLDv1 Group-Specific Query.
716 		 * If this is a group-specific MLDv1 query, we need only
717 		 * look up the single group to process it.
718 		 */
719 		inm = in6m_lookup_locked(ifp, &mld->mld_addr);
720 		if (inm != NULL) {
721 			CTR3(KTR_MLD, "process v1 query %s on ifp %p(%s)",
722 			    ip6_sprintf(ip6tbuf, &mld->mld_addr),
723 			    ifp, if_name(ifp));
724 			mld_v1_update_group(inm, timer);
725 		}
726 		/* XXX Clear embedded scope ID as userland won't expect it. */
727 		in6_clearscope(&mld->mld_addr);
728 	}
729 
730 	IF_ADDR_RUNLOCK(ifp);
731 	MLD_UNLOCK();
732 	IN6_MULTI_UNLOCK();
733 
734 	return (0);
735 }
736 
737 /*
738  * Update the report timer on a group in response to an MLDv1 query.
739  *
740  * If we are becoming the reporting member for this group, start the timer.
741  * If we already are the reporting member for this group, and timer is
742  * below the threshold, reset it.
743  *
744  * We may be updating the group for the first time since we switched
745  * to MLDv2. If we are, then we must clear any recorded source lists,
746  * and transition to REPORTING state; the group timer is overloaded
747  * for group and group-source query responses.
748  *
749  * Unlike MLDv2, the delay per group should be jittered
750  * to avoid bursts of MLDv1 reports.
751  */
752 static void
753 mld_v1_update_group(struct in6_multi *inm, const int timer)
754 {
755 #ifdef KTR
756 	char			 ip6tbuf[INET6_ADDRSTRLEN];
757 #endif
758 
759 	CTR4(KTR_MLD, "%s: %s/%s timer=%d", __func__,
760 	    ip6_sprintf(ip6tbuf, &inm->in6m_addr),
761 	    if_name(inm->in6m_ifp), timer);
762 
763 	IN6_MULTI_LOCK_ASSERT();
764 
765 	switch (inm->in6m_state) {
766 	case MLD_NOT_MEMBER:
767 	case MLD_SILENT_MEMBER:
768 		break;
769 	case MLD_REPORTING_MEMBER:
770 		if (inm->in6m_timer != 0 &&
771 		    inm->in6m_timer <= timer) {
772 			CTR1(KTR_MLD, "%s: REPORTING and timer running, "
773 			    "skipping.", __func__);
774 			break;
775 		}
776 		/* FALLTHROUGH */
777 	case MLD_SG_QUERY_PENDING_MEMBER:
778 	case MLD_G_QUERY_PENDING_MEMBER:
779 	case MLD_IDLE_MEMBER:
780 	case MLD_LAZY_MEMBER:
781 	case MLD_AWAKENING_MEMBER:
782 		CTR1(KTR_MLD, "%s: ->REPORTING", __func__);
783 		inm->in6m_state = MLD_REPORTING_MEMBER;
784 		inm->in6m_timer = MLD_RANDOM_DELAY(timer);
785 		V_current_state_timers_running6 = 1;
786 		break;
787 	case MLD_SLEEPING_MEMBER:
788 		CTR1(KTR_MLD, "%s: ->AWAKENING", __func__);
789 		inm->in6m_state = MLD_AWAKENING_MEMBER;
790 		break;
791 	case MLD_LEAVING_MEMBER:
792 		break;
793 	}
794 }
795 
796 /*
797  * Process a received MLDv2 general, group-specific or
798  * group-and-source-specific query.
799  *
800  * Assumes that the query header has been pulled up to sizeof(mldv2_query).
801  *
802  * Return 0 if successful, otherwise an appropriate error code is returned.
803  */
804 static int
805 mld_v2_input_query(struct ifnet *ifp, const struct ip6_hdr *ip6,
806     struct mbuf *m, const int off, const int icmp6len)
807 {
808 	struct mld_ifinfo	*mli;
809 	struct mldv2_query	*mld;
810 	struct in6_multi	*inm;
811 	uint32_t		 maxdelay, nsrc, qqi;
812 	int			 is_general_query;
813 	uint16_t		 timer;
814 	uint8_t			 qrv;
815 #ifdef KTR
816 	char			 ip6tbuf[INET6_ADDRSTRLEN];
817 #endif
818 
819 	is_general_query = 0;
820 
821 	/*
822 	 * RFC3810 Section 6.2: MLD queries must originate from
823 	 * a router's link-local address.
824 	 */
825 	if (!IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
826 		CTR3(KTR_MLD, "ignore v1 query src %s on ifp %p(%s)",
827 		    ip6_sprintf(ip6tbuf, &ip6->ip6_src),
828 		    ifp, if_name(ifp));
829 		return (0);
830 	}
831 
832 	CTR2(KTR_MLD, "input v2 query on ifp %p(%s)", ifp, if_name(ifp));
833 
834 	mld = (struct mldv2_query *)(mtod(m, uint8_t *) + off);
835 
836 	maxdelay = ntohs(mld->mld_maxdelay);	/* in 1/10ths of a second */
837 	if (maxdelay >= 32768) {
838 		maxdelay = (MLD_MRC_MANT(maxdelay) | 0x1000) <<
839 			   (MLD_MRC_EXP(maxdelay) + 3);
840 	}
841 	timer = (maxdelay * PR_FASTHZ) / MLD_TIMER_SCALE;
842 	if (timer == 0)
843 		timer = 1;
844 
845 	qrv = MLD_QRV(mld->mld_misc);
846 	if (qrv < 2) {
847 		CTR3(KTR_MLD, "%s: clamping qrv %d to %d", __func__,
848 		    qrv, MLD_RV_INIT);
849 		qrv = MLD_RV_INIT;
850 	}
851 
852 	qqi = mld->mld_qqi;
853 	if (qqi >= 128) {
854 		qqi = MLD_QQIC_MANT(mld->mld_qqi) <<
855 		     (MLD_QQIC_EXP(mld->mld_qqi) + 3);
856 	}
857 
858 	nsrc = ntohs(mld->mld_numsrc);
859 	if (nsrc > MLD_MAX_GS_SOURCES)
860 		return (EMSGSIZE);
861 	if (icmp6len < sizeof(struct mldv2_query) +
862 	    (nsrc * sizeof(struct in6_addr)))
863 		return (EMSGSIZE);
864 
865 	/*
866 	 * Do further input validation upfront to avoid resetting timers
867 	 * should we need to discard this query.
868 	 */
869 	if (IN6_IS_ADDR_UNSPECIFIED(&mld->mld_addr)) {
870 		/*
871 		 * A general query with a source list has undefined
872 		 * behaviour; discard it.
873 		 */
874 		if (nsrc > 0)
875 			return (EINVAL);
876 		is_general_query = 1;
877 	} else {
878 		/*
879 		 * Embed scope ID of receiving interface in MLD query for
880 		 * lookup whilst we don't hold other locks (due to KAME
881 		 * locking lameness). We own this mbuf chain just now.
882 		 */
883 		in6_setscope(&mld->mld_addr, ifp, NULL);
884 	}
885 
886 	IN6_MULTI_LOCK();
887 	MLD_LOCK();
888 
889 	mli = MLD_IFINFO(ifp);
890 	KASSERT(mli != NULL, ("%s: no mld_ifinfo for ifp %p", __func__, ifp));
891 
892 	/*
893 	 * Discard the v2 query if we're in Compatibility Mode.
894 	 * The RFC is pretty clear that hosts need to stay in MLDv1 mode
895 	 * until the Old Version Querier Present timer expires.
896 	 */
897 	if (mli->mli_version != MLD_VERSION_2)
898 		goto out_locked;
899 
900 	mld_set_version(mli, MLD_VERSION_2);
901 	mli->mli_rv = qrv;
902 	mli->mli_qi = qqi;
903 	mli->mli_qri = maxdelay;
904 
905 	CTR4(KTR_MLD, "%s: qrv %d qi %d maxdelay %d", __func__, qrv, qqi,
906 	    maxdelay);
907 
908 	if (is_general_query) {
909 		/*
910 		 * MLDv2 General Query.
911 		 *
912 		 * Schedule a current-state report on this ifp for
913 		 * all groups, possibly containing source lists.
914 		 *
915 		 * If there is a pending General Query response
916 		 * scheduled earlier than the selected delay, do
917 		 * not schedule any other reports.
918 		 * Otherwise, reset the interface timer.
919 		 */
920 		CTR2(KTR_MLD, "process v2 general query on ifp %p(%s)",
921 		    ifp, if_name(ifp));
922 		if (mli->mli_v2_timer == 0 || mli->mli_v2_timer >= timer) {
923 			mli->mli_v2_timer = MLD_RANDOM_DELAY(timer);
924 			V_interface_timers_running6 = 1;
925 		}
926 	} else {
927 		/*
928 		 * MLDv2 Group-specific or Group-and-source-specific Query.
929 		 *
930 		 * Group-source-specific queries are throttled on
931 		 * a per-group basis to defeat denial-of-service attempts.
932 		 * Queries for groups we are not a member of on this
933 		 * link are simply ignored.
934 		 */
935 		IF_ADDR_RLOCK(ifp);
936 		inm = in6m_lookup_locked(ifp, &mld->mld_addr);
937 		if (inm == NULL) {
938 			IF_ADDR_RUNLOCK(ifp);
939 			goto out_locked;
940 		}
941 		if (nsrc > 0) {
942 			if (!ratecheck(&inm->in6m_lastgsrtv,
943 			    &V_mld_gsrdelay)) {
944 				CTR1(KTR_MLD, "%s: GS query throttled.",
945 				    __func__);
946 				IF_ADDR_RUNLOCK(ifp);
947 				goto out_locked;
948 			}
949 		}
950 		CTR2(KTR_MLD, "process v2 group query on ifp %p(%s)",
951 		     ifp, if_name(ifp));
952 		/*
953 		 * If there is a pending General Query response
954 		 * scheduled sooner than the selected delay, no
955 		 * further report need be scheduled.
956 		 * Otherwise, prepare to respond to the
957 		 * group-specific or group-and-source query.
958 		 */
959 		if (mli->mli_v2_timer == 0 || mli->mli_v2_timer >= timer)
960 			mld_v2_process_group_query(inm, mli, timer, m, off);
961 
962 		/* XXX Clear embedded scope ID as userland won't expect it. */
963 		in6_clearscope(&mld->mld_addr);
964 		IF_ADDR_RUNLOCK(ifp);
965 	}
966 
967 out_locked:
968 	MLD_UNLOCK();
969 	IN6_MULTI_UNLOCK();
970 
971 	return (0);
972 }
973 
974 /*
975  * Process a recieved MLDv2 group-specific or group-and-source-specific
976  * query.
977  * Return <0 if any error occured. Currently this is ignored.
978  */
979 static int
980 mld_v2_process_group_query(struct in6_multi *inm, struct mld_ifinfo *mli,
981     int timer, struct mbuf *m0, const int off)
982 {
983 	struct mldv2_query	*mld;
984 	int			 retval;
985 	uint16_t		 nsrc;
986 
987 	IN6_MULTI_LOCK_ASSERT();
988 	MLD_LOCK_ASSERT();
989 
990 	retval = 0;
991 	mld = (struct mldv2_query *)(mtod(m0, uint8_t *) + off);
992 
993 	switch (inm->in6m_state) {
994 	case MLD_NOT_MEMBER:
995 	case MLD_SILENT_MEMBER:
996 	case MLD_SLEEPING_MEMBER:
997 	case MLD_LAZY_MEMBER:
998 	case MLD_AWAKENING_MEMBER:
999 	case MLD_IDLE_MEMBER:
1000 	case MLD_LEAVING_MEMBER:
1001 		return (retval);
1002 		break;
1003 	case MLD_REPORTING_MEMBER:
1004 	case MLD_G_QUERY_PENDING_MEMBER:
1005 	case MLD_SG_QUERY_PENDING_MEMBER:
1006 		break;
1007 	}
1008 
1009 	nsrc = ntohs(mld->mld_numsrc);
1010 
1011 	/*
1012 	 * Deal with group-specific queries upfront.
1013 	 * If any group query is already pending, purge any recorded
1014 	 * source-list state if it exists, and schedule a query response
1015 	 * for this group-specific query.
1016 	 */
1017 	if (nsrc == 0) {
1018 		if (inm->in6m_state == MLD_G_QUERY_PENDING_MEMBER ||
1019 		    inm->in6m_state == MLD_SG_QUERY_PENDING_MEMBER) {
1020 			in6m_clear_recorded(inm);
1021 			timer = min(inm->in6m_timer, timer);
1022 		}
1023 		inm->in6m_state = MLD_G_QUERY_PENDING_MEMBER;
1024 		inm->in6m_timer = MLD_RANDOM_DELAY(timer);
1025 		V_current_state_timers_running6 = 1;
1026 		return (retval);
1027 	}
1028 
1029 	/*
1030 	 * Deal with the case where a group-and-source-specific query has
1031 	 * been received but a group-specific query is already pending.
1032 	 */
1033 	if (inm->in6m_state == MLD_G_QUERY_PENDING_MEMBER) {
1034 		timer = min(inm->in6m_timer, timer);
1035 		inm->in6m_timer = MLD_RANDOM_DELAY(timer);
1036 		V_current_state_timers_running6 = 1;
1037 		return (retval);
1038 	}
1039 
1040 	/*
1041 	 * Finally, deal with the case where a group-and-source-specific
1042 	 * query has been received, where a response to a previous g-s-r
1043 	 * query exists, or none exists.
1044 	 * In this case, we need to parse the source-list which the Querier
1045 	 * has provided us with and check if we have any source list filter
1046 	 * entries at T1 for these sources. If we do not, there is no need
1047 	 * schedule a report and the query may be dropped.
1048 	 * If we do, we must record them and schedule a current-state
1049 	 * report for those sources.
1050 	 */
1051 	if (inm->in6m_nsrc > 0) {
1052 		struct mbuf		*m;
1053 		uint8_t			*sp;
1054 		int			 i, nrecorded;
1055 		int			 soff;
1056 
1057 		m = m0;
1058 		soff = off + sizeof(struct mldv2_query);
1059 		nrecorded = 0;
1060 		for (i = 0; i < nsrc; i++) {
1061 			sp = mtod(m, uint8_t *) + soff;
1062 			retval = in6m_record_source(inm,
1063 			    (const struct in6_addr *)sp);
1064 			if (retval < 0)
1065 				break;
1066 			nrecorded += retval;
1067 			soff += sizeof(struct in6_addr);
1068 			if (soff >= m->m_len) {
1069 				soff = soff - m->m_len;
1070 				m = m->m_next;
1071 				if (m == NULL)
1072 					break;
1073 			}
1074 		}
1075 		if (nrecorded > 0) {
1076 			CTR1(KTR_MLD,
1077 			    "%s: schedule response to SG query", __func__);
1078 			inm->in6m_state = MLD_SG_QUERY_PENDING_MEMBER;
1079 			inm->in6m_timer = MLD_RANDOM_DELAY(timer);
1080 			V_current_state_timers_running6 = 1;
1081 		}
1082 	}
1083 
1084 	return (retval);
1085 }
1086 
1087 /*
1088  * Process a received MLDv1 host membership report.
1089  * Assumes mld points to mld_hdr in pulled up mbuf chain.
1090  *
1091  * NOTE: Can't be fully const correct as we temporarily embed scope ID in
1092  * mld_addr. This is OK as we own the mbuf chain.
1093  */
1094 static int
1095 mld_v1_input_report(struct ifnet *ifp, const struct ip6_hdr *ip6,
1096     /*const*/ struct mld_hdr *mld)
1097 {
1098 	struct in6_addr		 src, dst;
1099 	struct in6_ifaddr	*ia;
1100 	struct in6_multi	*inm;
1101 #ifdef KTR
1102 	char			 ip6tbuf[INET6_ADDRSTRLEN];
1103 #endif
1104 
1105 	if (!mld_v1enable) {
1106 		CTR3(KTR_MLD, "ignore v1 report %s on ifp %p(%s)",
1107 		    ip6_sprintf(ip6tbuf, &mld->mld_addr),
1108 		    ifp, if_name(ifp));
1109 		return (0);
1110 	}
1111 
1112 	if (ifp->if_flags & IFF_LOOPBACK)
1113 		return (0);
1114 
1115 	/*
1116 	 * MLDv1 reports must originate from a host's link-local address,
1117 	 * or the unspecified address (when booting).
1118 	 */
1119 	src = ip6->ip6_src;
1120 	in6_clearscope(&src);
1121 	if (!IN6_IS_SCOPE_LINKLOCAL(&src) && !IN6_IS_ADDR_UNSPECIFIED(&src)) {
1122 		CTR3(KTR_MLD, "ignore v1 query src %s on ifp %p(%s)",
1123 		    ip6_sprintf(ip6tbuf, &ip6->ip6_src),
1124 		    ifp, if_name(ifp));
1125 		return (EINVAL);
1126 	}
1127 
1128 	/*
1129 	 * RFC2710 Section 4: MLDv1 reports must pertain to a multicast
1130 	 * group, and must be directed to the group itself.
1131 	 */
1132 	dst = ip6->ip6_dst;
1133 	in6_clearscope(&dst);
1134 	if (!IN6_IS_ADDR_MULTICAST(&mld->mld_addr) ||
1135 	    !IN6_ARE_ADDR_EQUAL(&mld->mld_addr, &dst)) {
1136 		CTR3(KTR_MLD, "ignore v1 query dst %s on ifp %p(%s)",
1137 		    ip6_sprintf(ip6tbuf, &ip6->ip6_dst),
1138 		    ifp, if_name(ifp));
1139 		return (EINVAL);
1140 	}
1141 
1142 	/*
1143 	 * Make sure we don't hear our own membership report, as fast
1144 	 * leave requires knowing that we are the only member of a
1145 	 * group. Assume we used the link-local address if available,
1146 	 * otherwise look for ::.
1147 	 *
1148 	 * XXX Note that scope ID comparison is needed for the address
1149 	 * returned by in6ifa_ifpforlinklocal(), but SHOULD NOT be
1150 	 * performed for the on-wire address.
1151 	 */
1152 	ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
1153 	if ((ia && IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, IA6_IN6(ia))) ||
1154 	    (ia == NULL && IN6_IS_ADDR_UNSPECIFIED(&src))) {
1155 		if (ia != NULL)
1156 			ifa_free(&ia->ia_ifa);
1157 		return (0);
1158 	}
1159 	if (ia != NULL)
1160 		ifa_free(&ia->ia_ifa);
1161 
1162 	CTR3(KTR_MLD, "process v1 report %s on ifp %p(%s)",
1163 	    ip6_sprintf(ip6tbuf, &mld->mld_addr), ifp, if_name(ifp));
1164 
1165 	/*
1166 	 * Embed scope ID of receiving interface in MLD query for lookup
1167 	 * whilst we don't hold other locks (due to KAME locking lameness).
1168 	 */
1169 	if (!IN6_IS_ADDR_UNSPECIFIED(&mld->mld_addr))
1170 		in6_setscope(&mld->mld_addr, ifp, NULL);
1171 
1172 	IN6_MULTI_LOCK();
1173 	MLD_LOCK();
1174 	IF_ADDR_RLOCK(ifp);
1175 
1176 	/*
1177 	 * MLDv1 report suppression.
1178 	 * If we are a member of this group, and our membership should be
1179 	 * reported, and our group timer is pending or about to be reset,
1180 	 * stop our group timer by transitioning to the 'lazy' state.
1181 	 */
1182 	inm = in6m_lookup_locked(ifp, &mld->mld_addr);
1183 	if (inm != NULL) {
1184 		struct mld_ifinfo *mli;
1185 
1186 		mli = inm->in6m_mli;
1187 		KASSERT(mli != NULL,
1188 		    ("%s: no mli for ifp %p", __func__, ifp));
1189 
1190 		/*
1191 		 * If we are in MLDv2 host mode, do not allow the
1192 		 * other host's MLDv1 report to suppress our reports.
1193 		 */
1194 		if (mli->mli_version == MLD_VERSION_2)
1195 			goto out_locked;
1196 
1197 		inm->in6m_timer = 0;
1198 
1199 		switch (inm->in6m_state) {
1200 		case MLD_NOT_MEMBER:
1201 		case MLD_SILENT_MEMBER:
1202 		case MLD_SLEEPING_MEMBER:
1203 			break;
1204 		case MLD_REPORTING_MEMBER:
1205 		case MLD_IDLE_MEMBER:
1206 		case MLD_AWAKENING_MEMBER:
1207 			CTR3(KTR_MLD,
1208 			    "report suppressed for %s on ifp %p(%s)",
1209 			    ip6_sprintf(ip6tbuf, &mld->mld_addr),
1210 			    ifp, if_name(ifp));
1211 		case MLD_LAZY_MEMBER:
1212 			inm->in6m_state = MLD_LAZY_MEMBER;
1213 			break;
1214 		case MLD_G_QUERY_PENDING_MEMBER:
1215 		case MLD_SG_QUERY_PENDING_MEMBER:
1216 		case MLD_LEAVING_MEMBER:
1217 			break;
1218 		}
1219 	}
1220 
1221 out_locked:
1222 	IF_ADDR_RUNLOCK(ifp);
1223 	MLD_UNLOCK();
1224 	IN6_MULTI_UNLOCK();
1225 
1226 	/* XXX Clear embedded scope ID as userland won't expect it. */
1227 	in6_clearscope(&mld->mld_addr);
1228 
1229 	return (0);
1230 }
1231 
1232 /*
1233  * MLD input path.
1234  *
1235  * Assume query messages which fit in a single ICMPv6 message header
1236  * have been pulled up.
1237  * Assume that userland will want to see the message, even if it
1238  * otherwise fails kernel input validation; do not free it.
1239  * Pullup may however free the mbuf chain m if it fails.
1240  *
1241  * Return IPPROTO_DONE if we freed m. Otherwise, return 0.
1242  */
1243 int
1244 mld_input(struct mbuf *m, int off, int icmp6len)
1245 {
1246 	struct ifnet	*ifp;
1247 	struct ip6_hdr	*ip6;
1248 	struct mld_hdr	*mld;
1249 	int		 mldlen;
1250 
1251 	CTR3(KTR_MLD, "%s: called w/mbuf (%p,%d)", __func__, m, off);
1252 
1253 	ifp = m->m_pkthdr.rcvif;
1254 
1255 	ip6 = mtod(m, struct ip6_hdr *);
1256 
1257 	/* Pullup to appropriate size. */
1258 	mld = (struct mld_hdr *)(mtod(m, uint8_t *) + off);
1259 	if (mld->mld_type == MLD_LISTENER_QUERY &&
1260 	    icmp6len >= sizeof(struct mldv2_query)) {
1261 		mldlen = sizeof(struct mldv2_query);
1262 	} else {
1263 		mldlen = sizeof(struct mld_hdr);
1264 	}
1265 	IP6_EXTHDR_GET(mld, struct mld_hdr *, m, off, mldlen);
1266 	if (mld == NULL) {
1267 		ICMP6STAT_INC(icp6s_badlen);
1268 		return (IPPROTO_DONE);
1269 	}
1270 
1271 	/*
1272 	 * Userland needs to see all of this traffic for implementing
1273 	 * the endpoint discovery portion of multicast routing.
1274 	 */
1275 	switch (mld->mld_type) {
1276 	case MLD_LISTENER_QUERY:
1277 		icmp6_ifstat_inc(ifp, ifs6_in_mldquery);
1278 		if (icmp6len == sizeof(struct mld_hdr)) {
1279 			if (mld_v1_input_query(ifp, ip6, mld) != 0)
1280 				return (0);
1281 		} else if (icmp6len >= sizeof(struct mldv2_query)) {
1282 			if (mld_v2_input_query(ifp, ip6, m, off,
1283 			    icmp6len) != 0)
1284 				return (0);
1285 		}
1286 		break;
1287 	case MLD_LISTENER_REPORT:
1288 		icmp6_ifstat_inc(ifp, ifs6_in_mldreport);
1289 		if (mld_v1_input_report(ifp, ip6, mld) != 0)
1290 			return (0);
1291 		break;
1292 	case MLDV2_LISTENER_REPORT:
1293 		icmp6_ifstat_inc(ifp, ifs6_in_mldreport);
1294 		break;
1295 	case MLD_LISTENER_DONE:
1296 		icmp6_ifstat_inc(ifp, ifs6_in_mlddone);
1297 		break;
1298 	default:
1299 		break;
1300 	}
1301 
1302 	return (0);
1303 }
1304 
1305 /*
1306  * Fast timeout handler (global).
1307  * VIMAGE: Timeout handlers are expected to service all vimages.
1308  */
1309 void
1310 mld_fasttimo(void)
1311 {
1312 	VNET_ITERATOR_DECL(vnet_iter);
1313 
1314 	VNET_LIST_RLOCK_NOSLEEP();
1315 	VNET_FOREACH(vnet_iter) {
1316 		CURVNET_SET(vnet_iter);
1317 		mld_fasttimo_vnet();
1318 		CURVNET_RESTORE();
1319 	}
1320 	VNET_LIST_RUNLOCK_NOSLEEP();
1321 }
1322 
1323 /*
1324  * Fast timeout handler (per-vnet).
1325  *
1326  * VIMAGE: Assume caller has set up our curvnet.
1327  */
1328 static void
1329 mld_fasttimo_vnet(void)
1330 {
1331 	struct ifqueue		 scq;	/* State-change packets */
1332 	struct ifqueue		 qrq;	/* Query response packets */
1333 	struct ifnet		*ifp;
1334 	struct mld_ifinfo	*mli;
1335 	struct ifmultiaddr	*ifma;
1336 	struct in6_multi	*inm, *tinm;
1337 	int			 uri_fasthz;
1338 
1339 	uri_fasthz = 0;
1340 
1341 	/*
1342 	 * Quick check to see if any work needs to be done, in order to
1343 	 * minimize the overhead of fasttimo processing.
1344 	 * SMPng: XXX Unlocked reads.
1345 	 */
1346 	if (!V_current_state_timers_running6 &&
1347 	    !V_interface_timers_running6 &&
1348 	    !V_state_change_timers_running6)
1349 		return;
1350 
1351 	IN6_MULTI_LOCK();
1352 	MLD_LOCK();
1353 
1354 	/*
1355 	 * MLDv2 General Query response timer processing.
1356 	 */
1357 	if (V_interface_timers_running6) {
1358 		CTR1(KTR_MLD, "%s: interface timers running", __func__);
1359 
1360 		V_interface_timers_running6 = 0;
1361 		LIST_FOREACH(mli, &V_mli_head, mli_link) {
1362 			if (mli->mli_v2_timer == 0) {
1363 				/* Do nothing. */
1364 			} else if (--mli->mli_v2_timer == 0) {
1365 				mld_v2_dispatch_general_query(mli);
1366 			} else {
1367 				V_interface_timers_running6 = 1;
1368 			}
1369 		}
1370 	}
1371 
1372 	if (!V_current_state_timers_running6 &&
1373 	    !V_state_change_timers_running6)
1374 		goto out_locked;
1375 
1376 	V_current_state_timers_running6 = 0;
1377 	V_state_change_timers_running6 = 0;
1378 
1379 	CTR1(KTR_MLD, "%s: state change timers running", __func__);
1380 
1381 	/*
1382 	 * MLD host report and state-change timer processing.
1383 	 * Note: Processing a v2 group timer may remove a node.
1384 	 */
1385 	LIST_FOREACH(mli, &V_mli_head, mli_link) {
1386 		ifp = mli->mli_ifp;
1387 
1388 		if (mli->mli_version == MLD_VERSION_2) {
1389 			uri_fasthz = MLD_RANDOM_DELAY(mli->mli_uri *
1390 			    PR_FASTHZ);
1391 
1392 			memset(&qrq, 0, sizeof(struct ifqueue));
1393 			IFQ_SET_MAXLEN(&qrq, MLD_MAX_G_GS_PACKETS);
1394 
1395 			memset(&scq, 0, sizeof(struct ifqueue));
1396 			IFQ_SET_MAXLEN(&scq, MLD_MAX_STATE_CHANGE_PACKETS);
1397 		}
1398 
1399 		IF_ADDR_RLOCK(ifp);
1400 		TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
1401 			if (ifma->ifma_addr->sa_family != AF_INET6 ||
1402 			    ifma->ifma_protospec == NULL)
1403 				continue;
1404 			inm = (struct in6_multi *)ifma->ifma_protospec;
1405 			switch (mli->mli_version) {
1406 			case MLD_VERSION_1:
1407 				mld_v1_process_group_timer(mli, inm);
1408 				break;
1409 			case MLD_VERSION_2:
1410 				mld_v2_process_group_timers(mli, &qrq,
1411 				    &scq, inm, uri_fasthz);
1412 				break;
1413 			}
1414 		}
1415 		IF_ADDR_RUNLOCK(ifp);
1416 
1417 		switch (mli->mli_version) {
1418 		case MLD_VERSION_1:
1419 			/*
1420 			 * Transmit reports for this lifecycle.  This
1421 			 * is done while not holding IF_ADDR_LOCK
1422 			 * since this can call
1423 			 * in6ifa_ifpforlinklocal() which locks
1424 			 * IF_ADDR_LOCK internally as well as
1425 			 * ip6_output() to transmit a packet.
1426 			 */
1427 			SLIST_FOREACH_SAFE(inm, &mli->mli_relinmhead,
1428 			    in6m_nrele, tinm) {
1429 				SLIST_REMOVE_HEAD(&mli->mli_relinmhead,
1430 				    in6m_nrele);
1431 				(void)mld_v1_transmit_report(inm,
1432 				    MLD_LISTENER_REPORT);
1433 			}
1434 			break;
1435 		case MLD_VERSION_2:
1436 			mld_dispatch_queue(&qrq, 0);
1437 			mld_dispatch_queue(&scq, 0);
1438 
1439 			/*
1440 			 * Free the in_multi reference(s) for
1441 			 * this lifecycle.
1442 			 */
1443 			SLIST_FOREACH_SAFE(inm, &mli->mli_relinmhead,
1444 			    in6m_nrele, tinm) {
1445 				SLIST_REMOVE_HEAD(&mli->mli_relinmhead,
1446 				    in6m_nrele);
1447 				in6m_release_locked(inm);
1448 			}
1449 			break;
1450 		}
1451 	}
1452 
1453 out_locked:
1454 	MLD_UNLOCK();
1455 	IN6_MULTI_UNLOCK();
1456 }
1457 
1458 /*
1459  * Update host report group timer.
1460  * Will update the global pending timer flags.
1461  */
1462 static void
1463 mld_v1_process_group_timer(struct mld_ifinfo *mli, struct in6_multi *inm)
1464 {
1465 	int report_timer_expired;
1466 
1467 	IN6_MULTI_LOCK_ASSERT();
1468 	MLD_LOCK_ASSERT();
1469 
1470 	if (inm->in6m_timer == 0) {
1471 		report_timer_expired = 0;
1472 	} else if (--inm->in6m_timer == 0) {
1473 		report_timer_expired = 1;
1474 	} else {
1475 		V_current_state_timers_running6 = 1;
1476 		return;
1477 	}
1478 
1479 	switch (inm->in6m_state) {
1480 	case MLD_NOT_MEMBER:
1481 	case MLD_SILENT_MEMBER:
1482 	case MLD_IDLE_MEMBER:
1483 	case MLD_LAZY_MEMBER:
1484 	case MLD_SLEEPING_MEMBER:
1485 	case MLD_AWAKENING_MEMBER:
1486 		break;
1487 	case MLD_REPORTING_MEMBER:
1488 		if (report_timer_expired) {
1489 			inm->in6m_state = MLD_IDLE_MEMBER;
1490 			SLIST_INSERT_HEAD(&mli->mli_relinmhead, inm,
1491 			    in6m_nrele);
1492 		}
1493 		break;
1494 	case MLD_G_QUERY_PENDING_MEMBER:
1495 	case MLD_SG_QUERY_PENDING_MEMBER:
1496 	case MLD_LEAVING_MEMBER:
1497 		break;
1498 	}
1499 }
1500 
1501 /*
1502  * Update a group's timers for MLDv2.
1503  * Will update the global pending timer flags.
1504  * Note: Unlocked read from mli.
1505  */
1506 static void
1507 mld_v2_process_group_timers(struct mld_ifinfo *mli,
1508     struct ifqueue *qrq, struct ifqueue *scq,
1509     struct in6_multi *inm, const int uri_fasthz)
1510 {
1511 	int query_response_timer_expired;
1512 	int state_change_retransmit_timer_expired;
1513 #ifdef KTR
1514 	char ip6tbuf[INET6_ADDRSTRLEN];
1515 #endif
1516 
1517 	IN6_MULTI_LOCK_ASSERT();
1518 	MLD_LOCK_ASSERT();
1519 
1520 	query_response_timer_expired = 0;
1521 	state_change_retransmit_timer_expired = 0;
1522 
1523 	/*
1524 	 * During a transition from compatibility mode back to MLDv2,
1525 	 * a group record in REPORTING state may still have its group
1526 	 * timer active. This is a no-op in this function; it is easier
1527 	 * to deal with it here than to complicate the slow-timeout path.
1528 	 */
1529 	if (inm->in6m_timer == 0) {
1530 		query_response_timer_expired = 0;
1531 	} else if (--inm->in6m_timer == 0) {
1532 		query_response_timer_expired = 1;
1533 	} else {
1534 		V_current_state_timers_running6 = 1;
1535 	}
1536 
1537 	if (inm->in6m_sctimer == 0) {
1538 		state_change_retransmit_timer_expired = 0;
1539 	} else if (--inm->in6m_sctimer == 0) {
1540 		state_change_retransmit_timer_expired = 1;
1541 	} else {
1542 		V_state_change_timers_running6 = 1;
1543 	}
1544 
1545 	/* We are in fasttimo, so be quick about it. */
1546 	if (!state_change_retransmit_timer_expired &&
1547 	    !query_response_timer_expired)
1548 		return;
1549 
1550 	switch (inm->in6m_state) {
1551 	case MLD_NOT_MEMBER:
1552 	case MLD_SILENT_MEMBER:
1553 	case MLD_SLEEPING_MEMBER:
1554 	case MLD_LAZY_MEMBER:
1555 	case MLD_AWAKENING_MEMBER:
1556 	case MLD_IDLE_MEMBER:
1557 		break;
1558 	case MLD_G_QUERY_PENDING_MEMBER:
1559 	case MLD_SG_QUERY_PENDING_MEMBER:
1560 		/*
1561 		 * Respond to a previously pending Group-Specific
1562 		 * or Group-and-Source-Specific query by enqueueing
1563 		 * the appropriate Current-State report for
1564 		 * immediate transmission.
1565 		 */
1566 		if (query_response_timer_expired) {
1567 			int retval;
1568 
1569 			retval = mld_v2_enqueue_group_record(qrq, inm, 0, 1,
1570 			    (inm->in6m_state == MLD_SG_QUERY_PENDING_MEMBER),
1571 			    0);
1572 			CTR2(KTR_MLD, "%s: enqueue record = %d",
1573 			    __func__, retval);
1574 			inm->in6m_state = MLD_REPORTING_MEMBER;
1575 			in6m_clear_recorded(inm);
1576 		}
1577 		/* FALLTHROUGH */
1578 	case MLD_REPORTING_MEMBER:
1579 	case MLD_LEAVING_MEMBER:
1580 		if (state_change_retransmit_timer_expired) {
1581 			/*
1582 			 * State-change retransmission timer fired.
1583 			 * If there are any further pending retransmissions,
1584 			 * set the global pending state-change flag, and
1585 			 * reset the timer.
1586 			 */
1587 			if (--inm->in6m_scrv > 0) {
1588 				inm->in6m_sctimer = uri_fasthz;
1589 				V_state_change_timers_running6 = 1;
1590 			}
1591 			/*
1592 			 * Retransmit the previously computed state-change
1593 			 * report. If there are no further pending
1594 			 * retransmissions, the mbuf queue will be consumed.
1595 			 * Update T0 state to T1 as we have now sent
1596 			 * a state-change.
1597 			 */
1598 			(void)mld_v2_merge_state_changes(inm, scq);
1599 
1600 			in6m_commit(inm);
1601 			CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
1602 			    ip6_sprintf(ip6tbuf, &inm->in6m_addr),
1603 			    if_name(inm->in6m_ifp));
1604 
1605 			/*
1606 			 * If we are leaving the group for good, make sure
1607 			 * we release MLD's reference to it.
1608 			 * This release must be deferred using a SLIST,
1609 			 * as we are called from a loop which traverses
1610 			 * the in_ifmultiaddr TAILQ.
1611 			 */
1612 			if (inm->in6m_state == MLD_LEAVING_MEMBER &&
1613 			    inm->in6m_scrv == 0) {
1614 				inm->in6m_state = MLD_NOT_MEMBER;
1615 				SLIST_INSERT_HEAD(&mli->mli_relinmhead,
1616 				    inm, in6m_nrele);
1617 			}
1618 		}
1619 		break;
1620 	}
1621 }
1622 
1623 /*
1624  * Switch to a different version on the given interface,
1625  * as per Section 9.12.
1626  */
1627 static void
1628 mld_set_version(struct mld_ifinfo *mli, const int version)
1629 {
1630 	int old_version_timer;
1631 
1632 	MLD_LOCK_ASSERT();
1633 
1634 	CTR4(KTR_MLD, "%s: switching to v%d on ifp %p(%s)", __func__,
1635 	    version, mli->mli_ifp, if_name(mli->mli_ifp));
1636 
1637 	if (version == MLD_VERSION_1) {
1638 		/*
1639 		 * Compute the "Older Version Querier Present" timer as per
1640 		 * Section 9.12.
1641 		 */
1642 		old_version_timer = (mli->mli_rv * mli->mli_qi) + mli->mli_qri;
1643 		old_version_timer *= PR_SLOWHZ;
1644 		mli->mli_v1_timer = old_version_timer;
1645 	}
1646 
1647 	if (mli->mli_v1_timer > 0 && mli->mli_version != MLD_VERSION_1) {
1648 		mli->mli_version = MLD_VERSION_1;
1649 		mld_v2_cancel_link_timers(mli);
1650 	}
1651 }
1652 
1653 /*
1654  * Cancel pending MLDv2 timers for the given link and all groups
1655  * joined on it; state-change, general-query, and group-query timers.
1656  */
1657 static void
1658 mld_v2_cancel_link_timers(struct mld_ifinfo *mli)
1659 {
1660 	struct ifmultiaddr	*ifma;
1661 	struct ifnet		*ifp;
1662 	struct in6_multi	*inm, *tinm;
1663 
1664 	CTR3(KTR_MLD, "%s: cancel v2 timers on ifp %p(%s)", __func__,
1665 	    mli->mli_ifp, if_name(mli->mli_ifp));
1666 
1667 	IN6_MULTI_LOCK_ASSERT();
1668 	MLD_LOCK_ASSERT();
1669 
1670 	/*
1671 	 * Fast-track this potentially expensive operation
1672 	 * by checking all the global 'timer pending' flags.
1673 	 */
1674 	if (!V_interface_timers_running6 &&
1675 	    !V_state_change_timers_running6 &&
1676 	    !V_current_state_timers_running6)
1677 		return;
1678 
1679 	mli->mli_v2_timer = 0;
1680 
1681 	ifp = mli->mli_ifp;
1682 
1683 	IF_ADDR_RLOCK(ifp);
1684 	TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
1685 		if (ifma->ifma_addr->sa_family != AF_INET6)
1686 			continue;
1687 		inm = (struct in6_multi *)ifma->ifma_protospec;
1688 		switch (inm->in6m_state) {
1689 		case MLD_NOT_MEMBER:
1690 		case MLD_SILENT_MEMBER:
1691 		case MLD_IDLE_MEMBER:
1692 		case MLD_LAZY_MEMBER:
1693 		case MLD_SLEEPING_MEMBER:
1694 		case MLD_AWAKENING_MEMBER:
1695 			break;
1696 		case MLD_LEAVING_MEMBER:
1697 			/*
1698 			 * If we are leaving the group and switching
1699 			 * version, we need to release the final
1700 			 * reference held for issuing the INCLUDE {}.
1701 			 */
1702 			SLIST_INSERT_HEAD(&mli->mli_relinmhead, inm,
1703 			    in6m_nrele);
1704 			/* FALLTHROUGH */
1705 		case MLD_G_QUERY_PENDING_MEMBER:
1706 		case MLD_SG_QUERY_PENDING_MEMBER:
1707 			in6m_clear_recorded(inm);
1708 			/* FALLTHROUGH */
1709 		case MLD_REPORTING_MEMBER:
1710 			inm->in6m_sctimer = 0;
1711 			inm->in6m_timer = 0;
1712 			inm->in6m_state = MLD_REPORTING_MEMBER;
1713 			/*
1714 			 * Free any pending MLDv2 state-change records.
1715 			 */
1716 			_IF_DRAIN(&inm->in6m_scq);
1717 			break;
1718 		}
1719 	}
1720 	IF_ADDR_RUNLOCK(ifp);
1721 	SLIST_FOREACH_SAFE(inm, &mli->mli_relinmhead, in6m_nrele, tinm) {
1722 		SLIST_REMOVE_HEAD(&mli->mli_relinmhead, in6m_nrele);
1723 		in6m_release_locked(inm);
1724 	}
1725 }
1726 
1727 /*
1728  * Global slowtimo handler.
1729  * VIMAGE: Timeout handlers are expected to service all vimages.
1730  */
1731 void
1732 mld_slowtimo(void)
1733 {
1734 	VNET_ITERATOR_DECL(vnet_iter);
1735 
1736 	VNET_LIST_RLOCK_NOSLEEP();
1737 	VNET_FOREACH(vnet_iter) {
1738 		CURVNET_SET(vnet_iter);
1739 		mld_slowtimo_vnet();
1740 		CURVNET_RESTORE();
1741 	}
1742 	VNET_LIST_RUNLOCK_NOSLEEP();
1743 }
1744 
1745 /*
1746  * Per-vnet slowtimo handler.
1747  */
1748 static void
1749 mld_slowtimo_vnet(void)
1750 {
1751 	struct mld_ifinfo *mli;
1752 
1753 	MLD_LOCK();
1754 
1755 	LIST_FOREACH(mli, &V_mli_head, mli_link) {
1756 		mld_v1_process_querier_timers(mli);
1757 	}
1758 
1759 	MLD_UNLOCK();
1760 }
1761 
1762 /*
1763  * Update the Older Version Querier Present timers for a link.
1764  * See Section 9.12 of RFC 3810.
1765  */
1766 static void
1767 mld_v1_process_querier_timers(struct mld_ifinfo *mli)
1768 {
1769 
1770 	MLD_LOCK_ASSERT();
1771 
1772 	if (mli->mli_version != MLD_VERSION_2 && --mli->mli_v1_timer == 0) {
1773 		/*
1774 		 * MLDv1 Querier Present timer expired; revert to MLDv2.
1775 		 */
1776 		CTR5(KTR_MLD,
1777 		    "%s: transition from v%d -> v%d on %p(%s)",
1778 		    __func__, mli->mli_version, MLD_VERSION_2,
1779 		    mli->mli_ifp, if_name(mli->mli_ifp));
1780 		mli->mli_version = MLD_VERSION_2;
1781 	}
1782 }
1783 
1784 /*
1785  * Transmit an MLDv1 report immediately.
1786  */
1787 static int
1788 mld_v1_transmit_report(struct in6_multi *in6m, const int type)
1789 {
1790 	struct ifnet		*ifp;
1791 	struct in6_ifaddr	*ia;
1792 	struct ip6_hdr		*ip6;
1793 	struct mbuf		*mh, *md;
1794 	struct mld_hdr		*mld;
1795 
1796 	IN6_MULTI_LOCK_ASSERT();
1797 	MLD_LOCK_ASSERT();
1798 
1799 	ifp = in6m->in6m_ifp;
1800 	ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
1801 	/* ia may be NULL if link-local address is tentative. */
1802 
1803 	mh = m_gethdr(M_NOWAIT, MT_DATA);
1804 	if (mh == NULL) {
1805 		if (ia != NULL)
1806 			ifa_free(&ia->ia_ifa);
1807 		return (ENOMEM);
1808 	}
1809 	md = m_get(M_NOWAIT, MT_DATA);
1810 	if (md == NULL) {
1811 		m_free(mh);
1812 		if (ia != NULL)
1813 			ifa_free(&ia->ia_ifa);
1814 		return (ENOMEM);
1815 	}
1816 	mh->m_next = md;
1817 
1818 	/*
1819 	 * FUTURE: Consider increasing alignment by ETHER_HDR_LEN, so
1820 	 * that ether_output() does not need to allocate another mbuf
1821 	 * for the header in the most common case.
1822 	 */
1823 	MH_ALIGN(mh, sizeof(struct ip6_hdr));
1824 	mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr);
1825 	mh->m_len = sizeof(struct ip6_hdr);
1826 
1827 	ip6 = mtod(mh, struct ip6_hdr *);
1828 	ip6->ip6_flow = 0;
1829 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
1830 	ip6->ip6_vfc |= IPV6_VERSION;
1831 	ip6->ip6_nxt = IPPROTO_ICMPV6;
1832 	ip6->ip6_src = ia ? ia->ia_addr.sin6_addr : in6addr_any;
1833 	ip6->ip6_dst = in6m->in6m_addr;
1834 
1835 	md->m_len = sizeof(struct mld_hdr);
1836 	mld = mtod(md, struct mld_hdr *);
1837 	mld->mld_type = type;
1838 	mld->mld_code = 0;
1839 	mld->mld_cksum = 0;
1840 	mld->mld_maxdelay = 0;
1841 	mld->mld_reserved = 0;
1842 	mld->mld_addr = in6m->in6m_addr;
1843 	in6_clearscope(&mld->mld_addr);
1844 	mld->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6,
1845 	    sizeof(struct ip6_hdr), sizeof(struct mld_hdr));
1846 
1847 	mld_save_context(mh, ifp);
1848 	mh->m_flags |= M_MLDV1;
1849 
1850 	mld_dispatch_packet(mh);
1851 
1852 	if (ia != NULL)
1853 		ifa_free(&ia->ia_ifa);
1854 	return (0);
1855 }
1856 
1857 /*
1858  * Process a state change from the upper layer for the given IPv6 group.
1859  *
1860  * Each socket holds a reference on the in_multi in its own ip_moptions.
1861  * The socket layer will have made the necessary updates to.the group
1862  * state, it is now up to MLD to issue a state change report if there
1863  * has been any change between T0 (when the last state-change was issued)
1864  * and T1 (now).
1865  *
1866  * We use the MLDv2 state machine at group level. The MLd module
1867  * however makes the decision as to which MLD protocol version to speak.
1868  * A state change *from* INCLUDE {} always means an initial join.
1869  * A state change *to* INCLUDE {} always means a final leave.
1870  *
1871  * If delay is non-zero, and the state change is an initial multicast
1872  * join, the state change report will be delayed by 'delay' ticks
1873  * in units of PR_FASTHZ if MLDv1 is active on the link; otherwise
1874  * the initial MLDv2 state change report will be delayed by whichever
1875  * is sooner, a pending state-change timer or delay itself.
1876  *
1877  * VIMAGE: curvnet should have been set by caller, as this routine
1878  * is called from the socket option handlers.
1879  */
1880 int
1881 mld_change_state(struct in6_multi *inm, const int delay)
1882 {
1883 	struct mld_ifinfo *mli;
1884 	struct ifnet *ifp;
1885 	int error;
1886 
1887 	IN6_MULTI_LOCK_ASSERT();
1888 
1889 	error = 0;
1890 
1891 	/*
1892 	 * Try to detect if the upper layer just asked us to change state
1893 	 * for an interface which has now gone away.
1894 	 */
1895 	KASSERT(inm->in6m_ifma != NULL, ("%s: no ifma", __func__));
1896 	ifp = inm->in6m_ifma->ifma_ifp;
1897 	if (ifp != NULL) {
1898 		/*
1899 		 * Sanity check that netinet6's notion of ifp is the
1900 		 * same as net's.
1901 		 */
1902 		KASSERT(inm->in6m_ifp == ifp, ("%s: bad ifp", __func__));
1903 	}
1904 
1905 	MLD_LOCK();
1906 
1907 	mli = MLD_IFINFO(ifp);
1908 	KASSERT(mli != NULL, ("%s: no mld_ifinfo for ifp %p", __func__, ifp));
1909 
1910 	/*
1911 	 * If we detect a state transition to or from MCAST_UNDEFINED
1912 	 * for this group, then we are starting or finishing an MLD
1913 	 * life cycle for this group.
1914 	 */
1915 	if (inm->in6m_st[1].iss_fmode != inm->in6m_st[0].iss_fmode) {
1916 		CTR3(KTR_MLD, "%s: inm transition %d -> %d", __func__,
1917 		    inm->in6m_st[0].iss_fmode, inm->in6m_st[1].iss_fmode);
1918 		if (inm->in6m_st[0].iss_fmode == MCAST_UNDEFINED) {
1919 			CTR1(KTR_MLD, "%s: initial join", __func__);
1920 			error = mld_initial_join(inm, mli, delay);
1921 			goto out_locked;
1922 		} else if (inm->in6m_st[1].iss_fmode == MCAST_UNDEFINED) {
1923 			CTR1(KTR_MLD, "%s: final leave", __func__);
1924 			mld_final_leave(inm, mli);
1925 			goto out_locked;
1926 		}
1927 	} else {
1928 		CTR1(KTR_MLD, "%s: filter set change", __func__);
1929 	}
1930 
1931 	error = mld_handle_state_change(inm, mli);
1932 
1933 out_locked:
1934 	MLD_UNLOCK();
1935 	return (error);
1936 }
1937 
1938 /*
1939  * Perform the initial join for an MLD group.
1940  *
1941  * When joining a group:
1942  *  If the group should have its MLD traffic suppressed, do nothing.
1943  *  MLDv1 starts sending MLDv1 host membership reports.
1944  *  MLDv2 will schedule an MLDv2 state-change report containing the
1945  *  initial state of the membership.
1946  *
1947  * If the delay argument is non-zero, then we must delay sending the
1948  * initial state change for delay ticks (in units of PR_FASTHZ).
1949  */
1950 static int
1951 mld_initial_join(struct in6_multi *inm, struct mld_ifinfo *mli,
1952     const int delay)
1953 {
1954 	struct ifnet		*ifp;
1955 	struct ifqueue		*ifq;
1956 	int			 error, retval, syncstates;
1957 	int			 odelay;
1958 #ifdef KTR
1959 	char			 ip6tbuf[INET6_ADDRSTRLEN];
1960 #endif
1961 
1962 	CTR4(KTR_MLD, "%s: initial join %s on ifp %p(%s)",
1963 	    __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
1964 	    inm->in6m_ifp, if_name(inm->in6m_ifp));
1965 
1966 	error = 0;
1967 	syncstates = 1;
1968 
1969 	ifp = inm->in6m_ifp;
1970 
1971 	IN6_MULTI_LOCK_ASSERT();
1972 	MLD_LOCK_ASSERT();
1973 
1974 	KASSERT(mli && mli->mli_ifp == ifp, ("%s: inconsistent ifp", __func__));
1975 
1976 	/*
1977 	 * Groups joined on loopback or marked as 'not reported',
1978 	 * enter the MLD_SILENT_MEMBER state and
1979 	 * are never reported in any protocol exchanges.
1980 	 * All other groups enter the appropriate state machine
1981 	 * for the version in use on this link.
1982 	 * A link marked as MLIF_SILENT causes MLD to be completely
1983 	 * disabled for the link.
1984 	 */
1985 	if ((ifp->if_flags & IFF_LOOPBACK) ||
1986 	    (mli->mli_flags & MLIF_SILENT) ||
1987 	    !mld_is_addr_reported(&inm->in6m_addr)) {
1988 		CTR1(KTR_MLD,
1989 "%s: not kicking state machine for silent group", __func__);
1990 		inm->in6m_state = MLD_SILENT_MEMBER;
1991 		inm->in6m_timer = 0;
1992 	} else {
1993 		/*
1994 		 * Deal with overlapping in_multi lifecycle.
1995 		 * If this group was LEAVING, then make sure
1996 		 * we drop the reference we picked up to keep the
1997 		 * group around for the final INCLUDE {} enqueue.
1998 		 */
1999 		if (mli->mli_version == MLD_VERSION_2 &&
2000 		    inm->in6m_state == MLD_LEAVING_MEMBER)
2001 			in6m_release_locked(inm);
2002 
2003 		inm->in6m_state = MLD_REPORTING_MEMBER;
2004 
2005 		switch (mli->mli_version) {
2006 		case MLD_VERSION_1:
2007 			/*
2008 			 * If a delay was provided, only use it if
2009 			 * it is greater than the delay normally
2010 			 * used for an MLDv1 state change report,
2011 			 * and delay sending the initial MLDv1 report
2012 			 * by not transitioning to the IDLE state.
2013 			 */
2014 			odelay = MLD_RANDOM_DELAY(MLD_V1_MAX_RI * PR_FASTHZ);
2015 			if (delay) {
2016 				inm->in6m_timer = max(delay, odelay);
2017 				V_current_state_timers_running6 = 1;
2018 			} else {
2019 				inm->in6m_state = MLD_IDLE_MEMBER;
2020 				error = mld_v1_transmit_report(inm,
2021 				     MLD_LISTENER_REPORT);
2022 				if (error == 0) {
2023 					inm->in6m_timer = odelay;
2024 					V_current_state_timers_running6 = 1;
2025 				}
2026 			}
2027 			break;
2028 
2029 		case MLD_VERSION_2:
2030 			/*
2031 			 * Defer update of T0 to T1, until the first copy
2032 			 * of the state change has been transmitted.
2033 			 */
2034 			syncstates = 0;
2035 
2036 			/*
2037 			 * Immediately enqueue a State-Change Report for
2038 			 * this interface, freeing any previous reports.
2039 			 * Don't kick the timers if there is nothing to do,
2040 			 * or if an error occurred.
2041 			 */
2042 			ifq = &inm->in6m_scq;
2043 			_IF_DRAIN(ifq);
2044 			retval = mld_v2_enqueue_group_record(ifq, inm, 1,
2045 			    0, 0, (mli->mli_flags & MLIF_USEALLOW));
2046 			CTR2(KTR_MLD, "%s: enqueue record = %d",
2047 			    __func__, retval);
2048 			if (retval <= 0) {
2049 				error = retval * -1;
2050 				break;
2051 			}
2052 
2053 			/*
2054 			 * Schedule transmission of pending state-change
2055 			 * report up to RV times for this link. The timer
2056 			 * will fire at the next mld_fasttimo (~200ms),
2057 			 * giving us an opportunity to merge the reports.
2058 			 *
2059 			 * If a delay was provided to this function, only
2060 			 * use this delay if sooner than the existing one.
2061 			 */
2062 			KASSERT(mli->mli_rv > 1,
2063 			   ("%s: invalid robustness %d", __func__,
2064 			    mli->mli_rv));
2065 			inm->in6m_scrv = mli->mli_rv;
2066 			if (delay) {
2067 				if (inm->in6m_sctimer > 1) {
2068 					inm->in6m_sctimer =
2069 					    min(inm->in6m_sctimer, delay);
2070 				} else
2071 					inm->in6m_sctimer = delay;
2072 			} else
2073 				inm->in6m_sctimer = 1;
2074 			V_state_change_timers_running6 = 1;
2075 
2076 			error = 0;
2077 			break;
2078 		}
2079 	}
2080 
2081 	/*
2082 	 * Only update the T0 state if state change is atomic,
2083 	 * i.e. we don't need to wait for a timer to fire before we
2084 	 * can consider the state change to have been communicated.
2085 	 */
2086 	if (syncstates) {
2087 		in6m_commit(inm);
2088 		CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
2089 		    ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2090 		    if_name(inm->in6m_ifp));
2091 	}
2092 
2093 	return (error);
2094 }
2095 
2096 /*
2097  * Issue an intermediate state change during the life-cycle.
2098  */
2099 static int
2100 mld_handle_state_change(struct in6_multi *inm, struct mld_ifinfo *mli)
2101 {
2102 	struct ifnet		*ifp;
2103 	int			 retval;
2104 #ifdef KTR
2105 	char			 ip6tbuf[INET6_ADDRSTRLEN];
2106 #endif
2107 
2108 	CTR4(KTR_MLD, "%s: state change for %s on ifp %p(%s)",
2109 	    __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2110 	    inm->in6m_ifp, if_name(inm->in6m_ifp));
2111 
2112 	ifp = inm->in6m_ifp;
2113 
2114 	IN6_MULTI_LOCK_ASSERT();
2115 	MLD_LOCK_ASSERT();
2116 
2117 	KASSERT(mli && mli->mli_ifp == ifp,
2118 	    ("%s: inconsistent ifp", __func__));
2119 
2120 	if ((ifp->if_flags & IFF_LOOPBACK) ||
2121 	    (mli->mli_flags & MLIF_SILENT) ||
2122 	    !mld_is_addr_reported(&inm->in6m_addr) ||
2123 	    (mli->mli_version != MLD_VERSION_2)) {
2124 		if (!mld_is_addr_reported(&inm->in6m_addr)) {
2125 			CTR1(KTR_MLD,
2126 "%s: not kicking state machine for silent group", __func__);
2127 		}
2128 		CTR1(KTR_MLD, "%s: nothing to do", __func__);
2129 		in6m_commit(inm);
2130 		CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
2131 		    ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2132 		    if_name(inm->in6m_ifp));
2133 		return (0);
2134 	}
2135 
2136 	_IF_DRAIN(&inm->in6m_scq);
2137 
2138 	retval = mld_v2_enqueue_group_record(&inm->in6m_scq, inm, 1, 0, 0,
2139 	    (mli->mli_flags & MLIF_USEALLOW));
2140 	CTR2(KTR_MLD, "%s: enqueue record = %d", __func__, retval);
2141 	if (retval <= 0)
2142 		return (-retval);
2143 
2144 	/*
2145 	 * If record(s) were enqueued, start the state-change
2146 	 * report timer for this group.
2147 	 */
2148 	inm->in6m_scrv = mli->mli_rv;
2149 	inm->in6m_sctimer = 1;
2150 	V_state_change_timers_running6 = 1;
2151 
2152 	return (0);
2153 }
2154 
2155 /*
2156  * Perform the final leave for a multicast address.
2157  *
2158  * When leaving a group:
2159  *  MLDv1 sends a DONE message, if and only if we are the reporter.
2160  *  MLDv2 enqueues a state-change report containing a transition
2161  *  to INCLUDE {} for immediate transmission.
2162  */
2163 static void
2164 mld_final_leave(struct in6_multi *inm, struct mld_ifinfo *mli)
2165 {
2166 	int syncstates;
2167 #ifdef KTR
2168 	char ip6tbuf[INET6_ADDRSTRLEN];
2169 #endif
2170 
2171 	syncstates = 1;
2172 
2173 	CTR4(KTR_MLD, "%s: final leave %s on ifp %p(%s)",
2174 	    __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2175 	    inm->in6m_ifp, if_name(inm->in6m_ifp));
2176 
2177 	IN6_MULTI_LOCK_ASSERT();
2178 	MLD_LOCK_ASSERT();
2179 
2180 	switch (inm->in6m_state) {
2181 	case MLD_NOT_MEMBER:
2182 	case MLD_SILENT_MEMBER:
2183 	case MLD_LEAVING_MEMBER:
2184 		/* Already leaving or left; do nothing. */
2185 		CTR1(KTR_MLD,
2186 "%s: not kicking state machine for silent group", __func__);
2187 		break;
2188 	case MLD_REPORTING_MEMBER:
2189 	case MLD_IDLE_MEMBER:
2190 	case MLD_G_QUERY_PENDING_MEMBER:
2191 	case MLD_SG_QUERY_PENDING_MEMBER:
2192 		if (mli->mli_version == MLD_VERSION_1) {
2193 #ifdef INVARIANTS
2194 			if (inm->in6m_state == MLD_G_QUERY_PENDING_MEMBER ||
2195 			    inm->in6m_state == MLD_SG_QUERY_PENDING_MEMBER)
2196 			panic("%s: MLDv2 state reached, not MLDv2 mode",
2197 			     __func__);
2198 #endif
2199 			mld_v1_transmit_report(inm, MLD_LISTENER_DONE);
2200 			inm->in6m_state = MLD_NOT_MEMBER;
2201 			V_current_state_timers_running6 = 1;
2202 		} else if (mli->mli_version == MLD_VERSION_2) {
2203 			/*
2204 			 * Stop group timer and all pending reports.
2205 			 * Immediately enqueue a state-change report
2206 			 * TO_IN {} to be sent on the next fast timeout,
2207 			 * giving us an opportunity to merge reports.
2208 			 */
2209 			_IF_DRAIN(&inm->in6m_scq);
2210 			inm->in6m_timer = 0;
2211 			inm->in6m_scrv = mli->mli_rv;
2212 			CTR4(KTR_MLD, "%s: Leaving %s/%s with %d "
2213 			    "pending retransmissions.", __func__,
2214 			    ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2215 			    if_name(inm->in6m_ifp), inm->in6m_scrv);
2216 			if (inm->in6m_scrv == 0) {
2217 				inm->in6m_state = MLD_NOT_MEMBER;
2218 				inm->in6m_sctimer = 0;
2219 			} else {
2220 				int retval;
2221 
2222 				in6m_acquire_locked(inm);
2223 
2224 				retval = mld_v2_enqueue_group_record(
2225 				    &inm->in6m_scq, inm, 1, 0, 0,
2226 				    (mli->mli_flags & MLIF_USEALLOW));
2227 				KASSERT(retval != 0,
2228 				    ("%s: enqueue record = %d", __func__,
2229 				     retval));
2230 
2231 				inm->in6m_state = MLD_LEAVING_MEMBER;
2232 				inm->in6m_sctimer = 1;
2233 				V_state_change_timers_running6 = 1;
2234 				syncstates = 0;
2235 			}
2236 			break;
2237 		}
2238 		break;
2239 	case MLD_LAZY_MEMBER:
2240 	case MLD_SLEEPING_MEMBER:
2241 	case MLD_AWAKENING_MEMBER:
2242 		/* Our reports are suppressed; do nothing. */
2243 		break;
2244 	}
2245 
2246 	if (syncstates) {
2247 		in6m_commit(inm);
2248 		CTR3(KTR_MLD, "%s: T1 -> T0 for %s/%s", __func__,
2249 		    ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2250 		    if_name(inm->in6m_ifp));
2251 		inm->in6m_st[1].iss_fmode = MCAST_UNDEFINED;
2252 		CTR3(KTR_MLD, "%s: T1 now MCAST_UNDEFINED for %p/%s",
2253 		    __func__, &inm->in6m_addr, if_name(inm->in6m_ifp));
2254 	}
2255 }
2256 
2257 /*
2258  * Enqueue an MLDv2 group record to the given output queue.
2259  *
2260  * If is_state_change is zero, a current-state record is appended.
2261  * If is_state_change is non-zero, a state-change report is appended.
2262  *
2263  * If is_group_query is non-zero, an mbuf packet chain is allocated.
2264  * If is_group_query is zero, and if there is a packet with free space
2265  * at the tail of the queue, it will be appended to providing there
2266  * is enough free space.
2267  * Otherwise a new mbuf packet chain is allocated.
2268  *
2269  * If is_source_query is non-zero, each source is checked to see if
2270  * it was recorded for a Group-Source query, and will be omitted if
2271  * it is not both in-mode and recorded.
2272  *
2273  * If use_block_allow is non-zero, state change reports for initial join
2274  * and final leave, on an inclusive mode group with a source list, will be
2275  * rewritten to use the ALLOW_NEW and BLOCK_OLD record types, respectively.
2276  *
2277  * The function will attempt to allocate leading space in the packet
2278  * for the IPv6+ICMP headers to be prepended without fragmenting the chain.
2279  *
2280  * If successful the size of all data appended to the queue is returned,
2281  * otherwise an error code less than zero is returned, or zero if
2282  * no record(s) were appended.
2283  */
2284 static int
2285 mld_v2_enqueue_group_record(struct ifqueue *ifq, struct in6_multi *inm,
2286     const int is_state_change, const int is_group_query,
2287     const int is_source_query, const int use_block_allow)
2288 {
2289 	struct mldv2_record	 mr;
2290 	struct mldv2_record	*pmr;
2291 	struct ifnet		*ifp;
2292 	struct ip6_msource	*ims, *nims;
2293 	struct mbuf		*m0, *m, *md;
2294 	int			 error, is_filter_list_change;
2295 	int			 minrec0len, m0srcs, msrcs, nbytes, off;
2296 	int			 record_has_sources;
2297 	int			 now;
2298 	int			 type;
2299 	uint8_t			 mode;
2300 #ifdef KTR
2301 	char			 ip6tbuf[INET6_ADDRSTRLEN];
2302 #endif
2303 
2304 	IN6_MULTI_LOCK_ASSERT();
2305 
2306 	error = 0;
2307 	ifp = inm->in6m_ifp;
2308 	is_filter_list_change = 0;
2309 	m = NULL;
2310 	m0 = NULL;
2311 	m0srcs = 0;
2312 	msrcs = 0;
2313 	nbytes = 0;
2314 	nims = NULL;
2315 	record_has_sources = 1;
2316 	pmr = NULL;
2317 	type = MLD_DO_NOTHING;
2318 	mode = inm->in6m_st[1].iss_fmode;
2319 
2320 	/*
2321 	 * If we did not transition out of ASM mode during t0->t1,
2322 	 * and there are no source nodes to process, we can skip
2323 	 * the generation of source records.
2324 	 */
2325 	if (inm->in6m_st[0].iss_asm > 0 && inm->in6m_st[1].iss_asm > 0 &&
2326 	    inm->in6m_nsrc == 0)
2327 		record_has_sources = 0;
2328 
2329 	if (is_state_change) {
2330 		/*
2331 		 * Queue a state change record.
2332 		 * If the mode did not change, and there are non-ASM
2333 		 * listeners or source filters present,
2334 		 * we potentially need to issue two records for the group.
2335 		 * If there are ASM listeners, and there was no filter
2336 		 * mode transition of any kind, do nothing.
2337 		 *
2338 		 * If we are transitioning to MCAST_UNDEFINED, we need
2339 		 * not send any sources. A transition to/from this state is
2340 		 * considered inclusive with some special treatment.
2341 		 *
2342 		 * If we are rewriting initial joins/leaves to use
2343 		 * ALLOW/BLOCK, and the group's membership is inclusive,
2344 		 * we need to send sources in all cases.
2345 		 */
2346 		if (mode != inm->in6m_st[0].iss_fmode) {
2347 			if (mode == MCAST_EXCLUDE) {
2348 				CTR1(KTR_MLD, "%s: change to EXCLUDE",
2349 				    __func__);
2350 				type = MLD_CHANGE_TO_EXCLUDE_MODE;
2351 			} else {
2352 				CTR1(KTR_MLD, "%s: change to INCLUDE",
2353 				    __func__);
2354 				if (use_block_allow) {
2355 					/*
2356 					 * XXX
2357 					 * Here we're interested in state
2358 					 * edges either direction between
2359 					 * MCAST_UNDEFINED and MCAST_INCLUDE.
2360 					 * Perhaps we should just check
2361 					 * the group state, rather than
2362 					 * the filter mode.
2363 					 */
2364 					if (mode == MCAST_UNDEFINED) {
2365 						type = MLD_BLOCK_OLD_SOURCES;
2366 					} else {
2367 						type = MLD_ALLOW_NEW_SOURCES;
2368 					}
2369 				} else {
2370 					type = MLD_CHANGE_TO_INCLUDE_MODE;
2371 					if (mode == MCAST_UNDEFINED)
2372 						record_has_sources = 0;
2373 				}
2374 			}
2375 		} else {
2376 			if (record_has_sources) {
2377 				is_filter_list_change = 1;
2378 			} else {
2379 				type = MLD_DO_NOTHING;
2380 			}
2381 		}
2382 	} else {
2383 		/*
2384 		 * Queue a current state record.
2385 		 */
2386 		if (mode == MCAST_EXCLUDE) {
2387 			type = MLD_MODE_IS_EXCLUDE;
2388 		} else if (mode == MCAST_INCLUDE) {
2389 			type = MLD_MODE_IS_INCLUDE;
2390 			KASSERT(inm->in6m_st[1].iss_asm == 0,
2391 			    ("%s: inm %p is INCLUDE but ASM count is %d",
2392 			     __func__, inm, inm->in6m_st[1].iss_asm));
2393 		}
2394 	}
2395 
2396 	/*
2397 	 * Generate the filter list changes using a separate function.
2398 	 */
2399 	if (is_filter_list_change)
2400 		return (mld_v2_enqueue_filter_change(ifq, inm));
2401 
2402 	if (type == MLD_DO_NOTHING) {
2403 		CTR3(KTR_MLD, "%s: nothing to do for %s/%s",
2404 		    __func__, ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2405 		    if_name(inm->in6m_ifp));
2406 		return (0);
2407 	}
2408 
2409 	/*
2410 	 * If any sources are present, we must be able to fit at least
2411 	 * one in the trailing space of the tail packet's mbuf,
2412 	 * ideally more.
2413 	 */
2414 	minrec0len = sizeof(struct mldv2_record);
2415 	if (record_has_sources)
2416 		minrec0len += sizeof(struct in6_addr);
2417 
2418 	CTR4(KTR_MLD, "%s: queueing %s for %s/%s", __func__,
2419 	    mld_rec_type_to_str(type),
2420 	    ip6_sprintf(ip6tbuf, &inm->in6m_addr),
2421 	    if_name(inm->in6m_ifp));
2422 
2423 	/*
2424 	 * Check if we have a packet in the tail of the queue for this
2425 	 * group into which the first group record for this group will fit.
2426 	 * Otherwise allocate a new packet.
2427 	 * Always allocate leading space for IP6+RA+ICMPV6+REPORT.
2428 	 * Note: Group records for G/GSR query responses MUST be sent
2429 	 * in their own packet.
2430 	 */
2431 	m0 = ifq->ifq_tail;
2432 	if (!is_group_query &&
2433 	    m0 != NULL &&
2434 	    (m0->m_pkthdr.PH_vt.vt_nrecs + 1 <= MLD_V2_REPORT_MAXRECS) &&
2435 	    (m0->m_pkthdr.len + minrec0len) <
2436 	     (ifp->if_mtu - MLD_MTUSPACE)) {
2437 		m0srcs = (ifp->if_mtu - m0->m_pkthdr.len -
2438 			    sizeof(struct mldv2_record)) /
2439 			    sizeof(struct in6_addr);
2440 		m = m0;
2441 		CTR1(KTR_MLD, "%s: use existing packet", __func__);
2442 	} else {
2443 		if (_IF_QFULL(ifq)) {
2444 			CTR1(KTR_MLD, "%s: outbound queue full", __func__);
2445 			return (-ENOMEM);
2446 		}
2447 		m = NULL;
2448 		m0srcs = (ifp->if_mtu - MLD_MTUSPACE -
2449 		    sizeof(struct mldv2_record)) / sizeof(struct in6_addr);
2450 		if (!is_state_change && !is_group_query)
2451 			m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2452 		if (m == NULL)
2453 			m = m_gethdr(M_NOWAIT, MT_DATA);
2454 		if (m == NULL)
2455 			return (-ENOMEM);
2456 
2457 		mld_save_context(m, ifp);
2458 
2459 		CTR1(KTR_MLD, "%s: allocated first packet", __func__);
2460 	}
2461 
2462 	/*
2463 	 * Append group record.
2464 	 * If we have sources, we don't know how many yet.
2465 	 */
2466 	mr.mr_type = type;
2467 	mr.mr_datalen = 0;
2468 	mr.mr_numsrc = 0;
2469 	mr.mr_addr = inm->in6m_addr;
2470 	in6_clearscope(&mr.mr_addr);
2471 	if (!m_append(m, sizeof(struct mldv2_record), (void *)&mr)) {
2472 		if (m != m0)
2473 			m_freem(m);
2474 		CTR1(KTR_MLD, "%s: m_append() failed.", __func__);
2475 		return (-ENOMEM);
2476 	}
2477 	nbytes += sizeof(struct mldv2_record);
2478 
2479 	/*
2480 	 * Append as many sources as will fit in the first packet.
2481 	 * If we are appending to a new packet, the chain allocation
2482 	 * may potentially use clusters; use m_getptr() in this case.
2483 	 * If we are appending to an existing packet, we need to obtain
2484 	 * a pointer to the group record after m_append(), in case a new
2485 	 * mbuf was allocated.
2486 	 *
2487 	 * Only append sources which are in-mode at t1. If we are
2488 	 * transitioning to MCAST_UNDEFINED state on the group, and
2489 	 * use_block_allow is zero, do not include source entries.
2490 	 * Otherwise, we need to include this source in the report.
2491 	 *
2492 	 * Only report recorded sources in our filter set when responding
2493 	 * to a group-source query.
2494 	 */
2495 	if (record_has_sources) {
2496 		if (m == m0) {
2497 			md = m_last(m);
2498 			pmr = (struct mldv2_record *)(mtod(md, uint8_t *) +
2499 			    md->m_len - nbytes);
2500 		} else {
2501 			md = m_getptr(m, 0, &off);
2502 			pmr = (struct mldv2_record *)(mtod(md, uint8_t *) +
2503 			    off);
2504 		}
2505 		msrcs = 0;
2506 		RB_FOREACH_SAFE(ims, ip6_msource_tree, &inm->in6m_srcs,
2507 		    nims) {
2508 			CTR2(KTR_MLD, "%s: visit node %s", __func__,
2509 			    ip6_sprintf(ip6tbuf, &ims->im6s_addr));
2510 			now = im6s_get_mode(inm, ims, 1);
2511 			CTR2(KTR_MLD, "%s: node is %d", __func__, now);
2512 			if ((now != mode) ||
2513 			    (now == mode &&
2514 			     (!use_block_allow && mode == MCAST_UNDEFINED))) {
2515 				CTR1(KTR_MLD, "%s: skip node", __func__);
2516 				continue;
2517 			}
2518 			if (is_source_query && ims->im6s_stp == 0) {
2519 				CTR1(KTR_MLD, "%s: skip unrecorded node",
2520 				    __func__);
2521 				continue;
2522 			}
2523 			CTR1(KTR_MLD, "%s: append node", __func__);
2524 			if (!m_append(m, sizeof(struct in6_addr),
2525 			    (void *)&ims->im6s_addr)) {
2526 				if (m != m0)
2527 					m_freem(m);
2528 				CTR1(KTR_MLD, "%s: m_append() failed.",
2529 				    __func__);
2530 				return (-ENOMEM);
2531 			}
2532 			nbytes += sizeof(struct in6_addr);
2533 			++msrcs;
2534 			if (msrcs == m0srcs)
2535 				break;
2536 		}
2537 		CTR2(KTR_MLD, "%s: msrcs is %d this packet", __func__,
2538 		    msrcs);
2539 		pmr->mr_numsrc = htons(msrcs);
2540 		nbytes += (msrcs * sizeof(struct in6_addr));
2541 	}
2542 
2543 	if (is_source_query && msrcs == 0) {
2544 		CTR1(KTR_MLD, "%s: no recorded sources to report", __func__);
2545 		if (m != m0)
2546 			m_freem(m);
2547 		return (0);
2548 	}
2549 
2550 	/*
2551 	 * We are good to go with first packet.
2552 	 */
2553 	if (m != m0) {
2554 		CTR1(KTR_MLD, "%s: enqueueing first packet", __func__);
2555 		m->m_pkthdr.PH_vt.vt_nrecs = 1;
2556 		_IF_ENQUEUE(ifq, m);
2557 	} else
2558 		m->m_pkthdr.PH_vt.vt_nrecs++;
2559 
2560 	/*
2561 	 * No further work needed if no source list in packet(s).
2562 	 */
2563 	if (!record_has_sources)
2564 		return (nbytes);
2565 
2566 	/*
2567 	 * Whilst sources remain to be announced, we need to allocate
2568 	 * a new packet and fill out as many sources as will fit.
2569 	 * Always try for a cluster first.
2570 	 */
2571 	while (nims != NULL) {
2572 		if (_IF_QFULL(ifq)) {
2573 			CTR1(KTR_MLD, "%s: outbound queue full", __func__);
2574 			return (-ENOMEM);
2575 		}
2576 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2577 		if (m == NULL)
2578 			m = m_gethdr(M_NOWAIT, MT_DATA);
2579 		if (m == NULL)
2580 			return (-ENOMEM);
2581 		mld_save_context(m, ifp);
2582 		md = m_getptr(m, 0, &off);
2583 		pmr = (struct mldv2_record *)(mtod(md, uint8_t *) + off);
2584 		CTR1(KTR_MLD, "%s: allocated next packet", __func__);
2585 
2586 		if (!m_append(m, sizeof(struct mldv2_record), (void *)&mr)) {
2587 			if (m != m0)
2588 				m_freem(m);
2589 			CTR1(KTR_MLD, "%s: m_append() failed.", __func__);
2590 			return (-ENOMEM);
2591 		}
2592 		m->m_pkthdr.PH_vt.vt_nrecs = 1;
2593 		nbytes += sizeof(struct mldv2_record);
2594 
2595 		m0srcs = (ifp->if_mtu - MLD_MTUSPACE -
2596 		    sizeof(struct mldv2_record)) / sizeof(struct in6_addr);
2597 
2598 		msrcs = 0;
2599 		RB_FOREACH_FROM(ims, ip6_msource_tree, nims) {
2600 			CTR2(KTR_MLD, "%s: visit node %s",
2601 			    __func__, ip6_sprintf(ip6tbuf, &ims->im6s_addr));
2602 			now = im6s_get_mode(inm, ims, 1);
2603 			if ((now != mode) ||
2604 			    (now == mode &&
2605 			     (!use_block_allow && mode == MCAST_UNDEFINED))) {
2606 				CTR1(KTR_MLD, "%s: skip node", __func__);
2607 				continue;
2608 			}
2609 			if (is_source_query && ims->im6s_stp == 0) {
2610 				CTR1(KTR_MLD, "%s: skip unrecorded node",
2611 				    __func__);
2612 				continue;
2613 			}
2614 			CTR1(KTR_MLD, "%s: append node", __func__);
2615 			if (!m_append(m, sizeof(struct in6_addr),
2616 			    (void *)&ims->im6s_addr)) {
2617 				if (m != m0)
2618 					m_freem(m);
2619 				CTR1(KTR_MLD, "%s: m_append() failed.",
2620 				    __func__);
2621 				return (-ENOMEM);
2622 			}
2623 			++msrcs;
2624 			if (msrcs == m0srcs)
2625 				break;
2626 		}
2627 		pmr->mr_numsrc = htons(msrcs);
2628 		nbytes += (msrcs * sizeof(struct in6_addr));
2629 
2630 		CTR1(KTR_MLD, "%s: enqueueing next packet", __func__);
2631 		_IF_ENQUEUE(ifq, m);
2632 	}
2633 
2634 	return (nbytes);
2635 }
2636 
2637 /*
2638  * Type used to mark record pass completion.
2639  * We exploit the fact we can cast to this easily from the
2640  * current filter modes on each ip_msource node.
2641  */
2642 typedef enum {
2643 	REC_NONE = 0x00,	/* MCAST_UNDEFINED */
2644 	REC_ALLOW = 0x01,	/* MCAST_INCLUDE */
2645 	REC_BLOCK = 0x02,	/* MCAST_EXCLUDE */
2646 	REC_FULL = REC_ALLOW | REC_BLOCK
2647 } rectype_t;
2648 
2649 /*
2650  * Enqueue an MLDv2 filter list change to the given output queue.
2651  *
2652  * Source list filter state is held in an RB-tree. When the filter list
2653  * for a group is changed without changing its mode, we need to compute
2654  * the deltas between T0 and T1 for each source in the filter set,
2655  * and enqueue the appropriate ALLOW_NEW/BLOCK_OLD records.
2656  *
2657  * As we may potentially queue two record types, and the entire R-B tree
2658  * needs to be walked at once, we break this out into its own function
2659  * so we can generate a tightly packed queue of packets.
2660  *
2661  * XXX This could be written to only use one tree walk, although that makes
2662  * serializing into the mbuf chains a bit harder. For now we do two walks
2663  * which makes things easier on us, and it may or may not be harder on
2664  * the L2 cache.
2665  *
2666  * If successful the size of all data appended to the queue is returned,
2667  * otherwise an error code less than zero is returned, or zero if
2668  * no record(s) were appended.
2669  */
2670 static int
2671 mld_v2_enqueue_filter_change(struct ifqueue *ifq, struct in6_multi *inm)
2672 {
2673 	static const int MINRECLEN =
2674 	    sizeof(struct mldv2_record) + sizeof(struct in6_addr);
2675 	struct ifnet		*ifp;
2676 	struct mldv2_record	 mr;
2677 	struct mldv2_record	*pmr;
2678 	struct ip6_msource	*ims, *nims;
2679 	struct mbuf		*m, *m0, *md;
2680 	int			 m0srcs, nbytes, npbytes, off, rsrcs, schanged;
2681 	int			 nallow, nblock;
2682 	uint8_t			 mode, now, then;
2683 	rectype_t		 crt, drt, nrt;
2684 #ifdef KTR
2685 	char			 ip6tbuf[INET6_ADDRSTRLEN];
2686 #endif
2687 
2688 	IN6_MULTI_LOCK_ASSERT();
2689 
2690 	if (inm->in6m_nsrc == 0 ||
2691 	    (inm->in6m_st[0].iss_asm > 0 && inm->in6m_st[1].iss_asm > 0))
2692 		return (0);
2693 
2694 	ifp = inm->in6m_ifp;			/* interface */
2695 	mode = inm->in6m_st[1].iss_fmode;	/* filter mode at t1 */
2696 	crt = REC_NONE;	/* current group record type */
2697 	drt = REC_NONE;	/* mask of completed group record types */
2698 	nrt = REC_NONE;	/* record type for current node */
2699 	m0srcs = 0;	/* # source which will fit in current mbuf chain */
2700 	npbytes = 0;	/* # of bytes appended this packet */
2701 	nbytes = 0;	/* # of bytes appended to group's state-change queue */
2702 	rsrcs = 0;	/* # sources encoded in current record */
2703 	schanged = 0;	/* # nodes encoded in overall filter change */
2704 	nallow = 0;	/* # of source entries in ALLOW_NEW */
2705 	nblock = 0;	/* # of source entries in BLOCK_OLD */
2706 	nims = NULL;	/* next tree node pointer */
2707 
2708 	/*
2709 	 * For each possible filter record mode.
2710 	 * The first kind of source we encounter tells us which
2711 	 * is the first kind of record we start appending.
2712 	 * If a node transitioned to UNDEFINED at t1, its mode is treated
2713 	 * as the inverse of the group's filter mode.
2714 	 */
2715 	while (drt != REC_FULL) {
2716 		do {
2717 			m0 = ifq->ifq_tail;
2718 			if (m0 != NULL &&
2719 			    (m0->m_pkthdr.PH_vt.vt_nrecs + 1 <=
2720 			     MLD_V2_REPORT_MAXRECS) &&
2721 			    (m0->m_pkthdr.len + MINRECLEN) <
2722 			     (ifp->if_mtu - MLD_MTUSPACE)) {
2723 				m = m0;
2724 				m0srcs = (ifp->if_mtu - m0->m_pkthdr.len -
2725 					    sizeof(struct mldv2_record)) /
2726 					    sizeof(struct in6_addr);
2727 				CTR1(KTR_MLD,
2728 				    "%s: use previous packet", __func__);
2729 			} else {
2730 				m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2731 				if (m == NULL)
2732 					m = m_gethdr(M_NOWAIT, MT_DATA);
2733 				if (m == NULL) {
2734 					CTR1(KTR_MLD,
2735 					    "%s: m_get*() failed", __func__);
2736 					return (-ENOMEM);
2737 				}
2738 				m->m_pkthdr.PH_vt.vt_nrecs = 0;
2739 				mld_save_context(m, ifp);
2740 				m0srcs = (ifp->if_mtu - MLD_MTUSPACE -
2741 				    sizeof(struct mldv2_record)) /
2742 				    sizeof(struct in6_addr);
2743 				npbytes = 0;
2744 				CTR1(KTR_MLD,
2745 				    "%s: allocated new packet", __func__);
2746 			}
2747 			/*
2748 			 * Append the MLD group record header to the
2749 			 * current packet's data area.
2750 			 * Recalculate pointer to free space for next
2751 			 * group record, in case m_append() allocated
2752 			 * a new mbuf or cluster.
2753 			 */
2754 			memset(&mr, 0, sizeof(mr));
2755 			mr.mr_addr = inm->in6m_addr;
2756 			in6_clearscope(&mr.mr_addr);
2757 			if (!m_append(m, sizeof(mr), (void *)&mr)) {
2758 				if (m != m0)
2759 					m_freem(m);
2760 				CTR1(KTR_MLD,
2761 				    "%s: m_append() failed", __func__);
2762 				return (-ENOMEM);
2763 			}
2764 			npbytes += sizeof(struct mldv2_record);
2765 			if (m != m0) {
2766 				/* new packet; offset in chain */
2767 				md = m_getptr(m, npbytes -
2768 				    sizeof(struct mldv2_record), &off);
2769 				pmr = (struct mldv2_record *)(mtod(md,
2770 				    uint8_t *) + off);
2771 			} else {
2772 				/* current packet; offset from last append */
2773 				md = m_last(m);
2774 				pmr = (struct mldv2_record *)(mtod(md,
2775 				    uint8_t *) + md->m_len -
2776 				    sizeof(struct mldv2_record));
2777 			}
2778 			/*
2779 			 * Begin walking the tree for this record type
2780 			 * pass, or continue from where we left off
2781 			 * previously if we had to allocate a new packet.
2782 			 * Only report deltas in-mode at t1.
2783 			 * We need not report included sources as allowed
2784 			 * if we are in inclusive mode on the group,
2785 			 * however the converse is not true.
2786 			 */
2787 			rsrcs = 0;
2788 			if (nims == NULL) {
2789 				nims = RB_MIN(ip6_msource_tree,
2790 				    &inm->in6m_srcs);
2791 			}
2792 			RB_FOREACH_FROM(ims, ip6_msource_tree, nims) {
2793 				CTR2(KTR_MLD, "%s: visit node %s", __func__,
2794 				    ip6_sprintf(ip6tbuf, &ims->im6s_addr));
2795 				now = im6s_get_mode(inm, ims, 1);
2796 				then = im6s_get_mode(inm, ims, 0);
2797 				CTR3(KTR_MLD, "%s: mode: t0 %d, t1 %d",
2798 				    __func__, then, now);
2799 				if (now == then) {
2800 					CTR1(KTR_MLD,
2801 					    "%s: skip unchanged", __func__);
2802 					continue;
2803 				}
2804 				if (mode == MCAST_EXCLUDE &&
2805 				    now == MCAST_INCLUDE) {
2806 					CTR1(KTR_MLD,
2807 					    "%s: skip IN src on EX group",
2808 					    __func__);
2809 					continue;
2810 				}
2811 				nrt = (rectype_t)now;
2812 				if (nrt == REC_NONE)
2813 					nrt = (rectype_t)(~mode & REC_FULL);
2814 				if (schanged++ == 0) {
2815 					crt = nrt;
2816 				} else if (crt != nrt)
2817 					continue;
2818 				if (!m_append(m, sizeof(struct in6_addr),
2819 				    (void *)&ims->im6s_addr)) {
2820 					if (m != m0)
2821 						m_freem(m);
2822 					CTR1(KTR_MLD,
2823 					    "%s: m_append() failed", __func__);
2824 					return (-ENOMEM);
2825 				}
2826 				nallow += !!(crt == REC_ALLOW);
2827 				nblock += !!(crt == REC_BLOCK);
2828 				if (++rsrcs == m0srcs)
2829 					break;
2830 			}
2831 			/*
2832 			 * If we did not append any tree nodes on this
2833 			 * pass, back out of allocations.
2834 			 */
2835 			if (rsrcs == 0) {
2836 				npbytes -= sizeof(struct mldv2_record);
2837 				if (m != m0) {
2838 					CTR1(KTR_MLD,
2839 					    "%s: m_free(m)", __func__);
2840 					m_freem(m);
2841 				} else {
2842 					CTR1(KTR_MLD,
2843 					    "%s: m_adj(m, -mr)", __func__);
2844 					m_adj(m, -((int)sizeof(
2845 					    struct mldv2_record)));
2846 				}
2847 				continue;
2848 			}
2849 			npbytes += (rsrcs * sizeof(struct in6_addr));
2850 			if (crt == REC_ALLOW)
2851 				pmr->mr_type = MLD_ALLOW_NEW_SOURCES;
2852 			else if (crt == REC_BLOCK)
2853 				pmr->mr_type = MLD_BLOCK_OLD_SOURCES;
2854 			pmr->mr_numsrc = htons(rsrcs);
2855 			/*
2856 			 * Count the new group record, and enqueue this
2857 			 * packet if it wasn't already queued.
2858 			 */
2859 			m->m_pkthdr.PH_vt.vt_nrecs++;
2860 			if (m != m0)
2861 				_IF_ENQUEUE(ifq, m);
2862 			nbytes += npbytes;
2863 		} while (nims != NULL);
2864 		drt |= crt;
2865 		crt = (~crt & REC_FULL);
2866 	}
2867 
2868 	CTR3(KTR_MLD, "%s: queued %d ALLOW_NEW, %d BLOCK_OLD", __func__,
2869 	    nallow, nblock);
2870 
2871 	return (nbytes);
2872 }
2873 
2874 static int
2875 mld_v2_merge_state_changes(struct in6_multi *inm, struct ifqueue *ifscq)
2876 {
2877 	struct ifqueue	*gq;
2878 	struct mbuf	*m;		/* pending state-change */
2879 	struct mbuf	*m0;		/* copy of pending state-change */
2880 	struct mbuf	*mt;		/* last state-change in packet */
2881 	int		 docopy, domerge;
2882 	u_int		 recslen;
2883 
2884 	docopy = 0;
2885 	domerge = 0;
2886 	recslen = 0;
2887 
2888 	IN6_MULTI_LOCK_ASSERT();
2889 	MLD_LOCK_ASSERT();
2890 
2891 	/*
2892 	 * If there are further pending retransmissions, make a writable
2893 	 * copy of each queued state-change message before merging.
2894 	 */
2895 	if (inm->in6m_scrv > 0)
2896 		docopy = 1;
2897 
2898 	gq = &inm->in6m_scq;
2899 #ifdef KTR
2900 	if (gq->ifq_head == NULL) {
2901 		CTR2(KTR_MLD, "%s: WARNING: queue for inm %p is empty",
2902 		    __func__, inm);
2903 	}
2904 #endif
2905 
2906 	m = gq->ifq_head;
2907 	while (m != NULL) {
2908 		/*
2909 		 * Only merge the report into the current packet if
2910 		 * there is sufficient space to do so; an MLDv2 report
2911 		 * packet may only contain 65,535 group records.
2912 		 * Always use a simple mbuf chain concatentation to do this,
2913 		 * as large state changes for single groups may have
2914 		 * allocated clusters.
2915 		 */
2916 		domerge = 0;
2917 		mt = ifscq->ifq_tail;
2918 		if (mt != NULL) {
2919 			recslen = m_length(m, NULL);
2920 
2921 			if ((mt->m_pkthdr.PH_vt.vt_nrecs +
2922 			    m->m_pkthdr.PH_vt.vt_nrecs <=
2923 			    MLD_V2_REPORT_MAXRECS) &&
2924 			    (mt->m_pkthdr.len + recslen <=
2925 			    (inm->in6m_ifp->if_mtu - MLD_MTUSPACE)))
2926 				domerge = 1;
2927 		}
2928 
2929 		if (!domerge && _IF_QFULL(gq)) {
2930 			CTR2(KTR_MLD,
2931 			    "%s: outbound queue full, skipping whole packet %p",
2932 			    __func__, m);
2933 			mt = m->m_nextpkt;
2934 			if (!docopy)
2935 				m_freem(m);
2936 			m = mt;
2937 			continue;
2938 		}
2939 
2940 		if (!docopy) {
2941 			CTR2(KTR_MLD, "%s: dequeueing %p", __func__, m);
2942 			_IF_DEQUEUE(gq, m0);
2943 			m = m0->m_nextpkt;
2944 		} else {
2945 			CTR2(KTR_MLD, "%s: copying %p", __func__, m);
2946 			m0 = m_dup(m, M_NOWAIT);
2947 			if (m0 == NULL)
2948 				return (ENOMEM);
2949 			m0->m_nextpkt = NULL;
2950 			m = m->m_nextpkt;
2951 		}
2952 
2953 		if (!domerge) {
2954 			CTR3(KTR_MLD, "%s: queueing %p to ifscq %p)",
2955 			    __func__, m0, ifscq);
2956 			_IF_ENQUEUE(ifscq, m0);
2957 		} else {
2958 			struct mbuf *mtl;	/* last mbuf of packet mt */
2959 
2960 			CTR3(KTR_MLD, "%s: merging %p with ifscq tail %p)",
2961 			    __func__, m0, mt);
2962 
2963 			mtl = m_last(mt);
2964 			m0->m_flags &= ~M_PKTHDR;
2965 			mt->m_pkthdr.len += recslen;
2966 			mt->m_pkthdr.PH_vt.vt_nrecs +=
2967 			    m0->m_pkthdr.PH_vt.vt_nrecs;
2968 
2969 			mtl->m_next = m0;
2970 		}
2971 	}
2972 
2973 	return (0);
2974 }
2975 
2976 /*
2977  * Respond to a pending MLDv2 General Query.
2978  */
2979 static void
2980 mld_v2_dispatch_general_query(struct mld_ifinfo *mli)
2981 {
2982 	struct ifmultiaddr	*ifma;
2983 	struct ifnet		*ifp;
2984 	struct in6_multi	*inm;
2985 	int			 retval;
2986 
2987 	IN6_MULTI_LOCK_ASSERT();
2988 	MLD_LOCK_ASSERT();
2989 
2990 	KASSERT(mli->mli_version == MLD_VERSION_2,
2991 	    ("%s: called when version %d", __func__, mli->mli_version));
2992 
2993 	ifp = mli->mli_ifp;
2994 
2995 	IF_ADDR_RLOCK(ifp);
2996 	TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
2997 		if (ifma->ifma_addr->sa_family != AF_INET6 ||
2998 		    ifma->ifma_protospec == NULL)
2999 			continue;
3000 
3001 		inm = (struct in6_multi *)ifma->ifma_protospec;
3002 		KASSERT(ifp == inm->in6m_ifp,
3003 		    ("%s: inconsistent ifp", __func__));
3004 
3005 		switch (inm->in6m_state) {
3006 		case MLD_NOT_MEMBER:
3007 		case MLD_SILENT_MEMBER:
3008 			break;
3009 		case MLD_REPORTING_MEMBER:
3010 		case MLD_IDLE_MEMBER:
3011 		case MLD_LAZY_MEMBER:
3012 		case MLD_SLEEPING_MEMBER:
3013 		case MLD_AWAKENING_MEMBER:
3014 			inm->in6m_state = MLD_REPORTING_MEMBER;
3015 			retval = mld_v2_enqueue_group_record(&mli->mli_gq,
3016 			    inm, 0, 0, 0, 0);
3017 			CTR2(KTR_MLD, "%s: enqueue record = %d",
3018 			    __func__, retval);
3019 			break;
3020 		case MLD_G_QUERY_PENDING_MEMBER:
3021 		case MLD_SG_QUERY_PENDING_MEMBER:
3022 		case MLD_LEAVING_MEMBER:
3023 			break;
3024 		}
3025 	}
3026 	IF_ADDR_RUNLOCK(ifp);
3027 
3028 	mld_dispatch_queue(&mli->mli_gq, MLD_MAX_RESPONSE_BURST);
3029 
3030 	/*
3031 	 * Slew transmission of bursts over 500ms intervals.
3032 	 */
3033 	if (mli->mli_gq.ifq_head != NULL) {
3034 		mli->mli_v2_timer = 1 + MLD_RANDOM_DELAY(
3035 		    MLD_RESPONSE_BURST_INTERVAL);
3036 		V_interface_timers_running6 = 1;
3037 	}
3038 }
3039 
3040 /*
3041  * Transmit the next pending message in the output queue.
3042  *
3043  * VIMAGE: Needs to store/restore vnet pointer on a per-mbuf-chain basis.
3044  * MRT: Nothing needs to be done, as MLD traffic is always local to
3045  * a link and uses a link-scope multicast address.
3046  */
3047 static void
3048 mld_dispatch_packet(struct mbuf *m)
3049 {
3050 	struct ip6_moptions	 im6o;
3051 	struct ifnet		*ifp;
3052 	struct ifnet		*oifp;
3053 	struct mbuf		*m0;
3054 	struct mbuf		*md;
3055 	struct ip6_hdr		*ip6;
3056 	struct mld_hdr		*mld;
3057 	int			 error;
3058 	int			 off;
3059 	int			 type;
3060 	uint32_t		 ifindex;
3061 
3062 	CTR2(KTR_MLD, "%s: transmit %p", __func__, m);
3063 
3064 	/*
3065 	 * Set VNET image pointer from enqueued mbuf chain
3066 	 * before doing anything else. Whilst we use interface
3067 	 * indexes to guard against interface detach, they are
3068 	 * unique to each VIMAGE and must be retrieved.
3069 	 */
3070 	ifindex = mld_restore_context(m);
3071 
3072 	/*
3073 	 * Check if the ifnet still exists. This limits the scope of
3074 	 * any race in the absence of a global ifp lock for low cost
3075 	 * (an array lookup).
3076 	 */
3077 	ifp = ifnet_byindex(ifindex);
3078 	if (ifp == NULL) {
3079 		CTR3(KTR_MLD, "%s: dropped %p as ifindex %u went away.",
3080 		    __func__, m, ifindex);
3081 		m_freem(m);
3082 		IP6STAT_INC(ip6s_noroute);
3083 		goto out;
3084 	}
3085 
3086 	im6o.im6o_multicast_hlim  = 1;
3087 	im6o.im6o_multicast_loop = (V_ip6_mrouter != NULL);
3088 	im6o.im6o_multicast_ifp = ifp;
3089 
3090 	if (m->m_flags & M_MLDV1) {
3091 		m0 = m;
3092 	} else {
3093 		m0 = mld_v2_encap_report(ifp, m);
3094 		if (m0 == NULL) {
3095 			CTR2(KTR_MLD, "%s: dropped %p", __func__, m);
3096 			IP6STAT_INC(ip6s_odropped);
3097 			goto out;
3098 		}
3099 	}
3100 
3101 	mld_scrub_context(m0);
3102 	m_clrprotoflags(m);
3103 	m0->m_pkthdr.rcvif = V_loif;
3104 
3105 	ip6 = mtod(m0, struct ip6_hdr *);
3106 #if 0
3107 	(void)in6_setscope(&ip6->ip6_dst, ifp, NULL);	/* XXX LOR */
3108 #else
3109 	/*
3110 	 * XXX XXX Break some KPI rules to prevent an LOR which would
3111 	 * occur if we called in6_setscope() at transmission.
3112 	 * See comments at top of file.
3113 	 */
3114 	MLD_EMBEDSCOPE(&ip6->ip6_dst, ifp->if_index);
3115 #endif
3116 
3117 	/*
3118 	 * Retrieve the ICMPv6 type before handoff to ip6_output(),
3119 	 * so we can bump the stats.
3120 	 */
3121 	md = m_getptr(m0, sizeof(struct ip6_hdr), &off);
3122 	mld = (struct mld_hdr *)(mtod(md, uint8_t *) + off);
3123 	type = mld->mld_type;
3124 
3125 	error = ip6_output(m0, &mld_po, NULL, IPV6_UNSPECSRC, &im6o,
3126 	    &oifp, NULL);
3127 	if (error) {
3128 		CTR3(KTR_MLD, "%s: ip6_output(%p) = %d", __func__, m0, error);
3129 		goto out;
3130 	}
3131 	ICMP6STAT_INC(icp6s_outhist[type]);
3132 	if (oifp != NULL) {
3133 		icmp6_ifstat_inc(oifp, ifs6_out_msg);
3134 		switch (type) {
3135 		case MLD_LISTENER_REPORT:
3136 		case MLDV2_LISTENER_REPORT:
3137 			icmp6_ifstat_inc(oifp, ifs6_out_mldreport);
3138 			break;
3139 		case MLD_LISTENER_DONE:
3140 			icmp6_ifstat_inc(oifp, ifs6_out_mlddone);
3141 			break;
3142 		}
3143 	}
3144 out:
3145 	return;
3146 }
3147 
3148 /*
3149  * Encapsulate an MLDv2 report.
3150  *
3151  * KAME IPv6 requires that hop-by-hop options be passed separately,
3152  * and that the IPv6 header be prepended in a separate mbuf.
3153  *
3154  * Returns a pointer to the new mbuf chain head, or NULL if the
3155  * allocation failed.
3156  */
3157 static struct mbuf *
3158 mld_v2_encap_report(struct ifnet *ifp, struct mbuf *m)
3159 {
3160 	struct mbuf		*mh;
3161 	struct mldv2_report	*mld;
3162 	struct ip6_hdr		*ip6;
3163 	struct in6_ifaddr	*ia;
3164 	int			 mldreclen;
3165 
3166 	KASSERT(ifp != NULL, ("%s: null ifp", __func__));
3167 	KASSERT((m->m_flags & M_PKTHDR),
3168 	    ("%s: mbuf chain %p is !M_PKTHDR", __func__, m));
3169 
3170 	/*
3171 	 * RFC3590: OK to send as :: or tentative during DAD.
3172 	 */
3173 	ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
3174 	if (ia == NULL)
3175 		CTR1(KTR_MLD, "%s: warning: ia is NULL", __func__);
3176 
3177 	mh = m_gethdr(M_NOWAIT, MT_DATA);
3178 	if (mh == NULL) {
3179 		if (ia != NULL)
3180 			ifa_free(&ia->ia_ifa);
3181 		m_freem(m);
3182 		return (NULL);
3183 	}
3184 	MH_ALIGN(mh, sizeof(struct ip6_hdr) + sizeof(struct mldv2_report));
3185 
3186 	mldreclen = m_length(m, NULL);
3187 	CTR2(KTR_MLD, "%s: mldreclen is %d", __func__, mldreclen);
3188 
3189 	mh->m_len = sizeof(struct ip6_hdr) + sizeof(struct mldv2_report);
3190 	mh->m_pkthdr.len = sizeof(struct ip6_hdr) +
3191 	    sizeof(struct mldv2_report) + mldreclen;
3192 
3193 	ip6 = mtod(mh, struct ip6_hdr *);
3194 	ip6->ip6_flow = 0;
3195 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
3196 	ip6->ip6_vfc |= IPV6_VERSION;
3197 	ip6->ip6_nxt = IPPROTO_ICMPV6;
3198 	ip6->ip6_src = ia ? ia->ia_addr.sin6_addr : in6addr_any;
3199 	if (ia != NULL)
3200 		ifa_free(&ia->ia_ifa);
3201 	ip6->ip6_dst = in6addr_linklocal_allv2routers;
3202 	/* scope ID will be set in netisr */
3203 
3204 	mld = (struct mldv2_report *)(ip6 + 1);
3205 	mld->mld_type = MLDV2_LISTENER_REPORT;
3206 	mld->mld_code = 0;
3207 	mld->mld_cksum = 0;
3208 	mld->mld_v2_reserved = 0;
3209 	mld->mld_v2_numrecs = htons(m->m_pkthdr.PH_vt.vt_nrecs);
3210 	m->m_pkthdr.PH_vt.vt_nrecs = 0;
3211 
3212 	mh->m_next = m;
3213 	mld->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6,
3214 	    sizeof(struct ip6_hdr), sizeof(struct mldv2_report) + mldreclen);
3215 	return (mh);
3216 }
3217 
3218 #ifdef KTR
3219 static char *
3220 mld_rec_type_to_str(const int type)
3221 {
3222 
3223 	switch (type) {
3224 		case MLD_CHANGE_TO_EXCLUDE_MODE:
3225 			return "TO_EX";
3226 			break;
3227 		case MLD_CHANGE_TO_INCLUDE_MODE:
3228 			return "TO_IN";
3229 			break;
3230 		case MLD_MODE_IS_EXCLUDE:
3231 			return "MODE_EX";
3232 			break;
3233 		case MLD_MODE_IS_INCLUDE:
3234 			return "MODE_IN";
3235 			break;
3236 		case MLD_ALLOW_NEW_SOURCES:
3237 			return "ALLOW_NEW";
3238 			break;
3239 		case MLD_BLOCK_OLD_SOURCES:
3240 			return "BLOCK_OLD";
3241 			break;
3242 		default:
3243 			break;
3244 	}
3245 	return "unknown";
3246 }
3247 #endif
3248 
3249 static void
3250 mld_init(void *unused __unused)
3251 {
3252 
3253 	CTR1(KTR_MLD, "%s: initializing", __func__);
3254 	MLD_LOCK_INIT();
3255 
3256 	ip6_initpktopts(&mld_po);
3257 	mld_po.ip6po_hlim = 1;
3258 	mld_po.ip6po_hbh = &mld_ra.hbh;
3259 	mld_po.ip6po_prefer_tempaddr = IP6PO_TEMPADDR_NOTPREFER;
3260 	mld_po.ip6po_flags = IP6PO_DONTFRAG;
3261 }
3262 SYSINIT(mld_init, SI_SUB_PSEUDO, SI_ORDER_MIDDLE, mld_init, NULL);
3263 
3264 static void
3265 mld_uninit(void *unused __unused)
3266 {
3267 
3268 	CTR1(KTR_MLD, "%s: tearing down", __func__);
3269 	MLD_LOCK_DESTROY();
3270 }
3271 SYSUNINIT(mld_uninit, SI_SUB_PSEUDO, SI_ORDER_MIDDLE, mld_uninit, NULL);
3272 
3273 static void
3274 vnet_mld_init(const void *unused __unused)
3275 {
3276 
3277 	CTR1(KTR_MLD, "%s: initializing", __func__);
3278 
3279 	LIST_INIT(&V_mli_head);
3280 }
3281 VNET_SYSINIT(vnet_mld_init, SI_SUB_PSEUDO, SI_ORDER_ANY, vnet_mld_init,
3282     NULL);
3283 
3284 static void
3285 vnet_mld_uninit(const void *unused __unused)
3286 {
3287 
3288 	CTR1(KTR_MLD, "%s: tearing down", __func__);
3289 
3290 	KASSERT(LIST_EMPTY(&V_mli_head),
3291 	    ("%s: mli list not empty; ifnets not detached?", __func__));
3292 }
3293 VNET_SYSUNINIT(vnet_mld_uninit, SI_SUB_PSEUDO, SI_ORDER_ANY, vnet_mld_uninit,
3294     NULL);
3295 
3296 static int
3297 mld_modevent(module_t mod, int type, void *unused __unused)
3298 {
3299 
3300     switch (type) {
3301     case MOD_LOAD:
3302     case MOD_UNLOAD:
3303 	break;
3304     default:
3305 	return (EOPNOTSUPP);
3306     }
3307     return (0);
3308 }
3309 
3310 static moduledata_t mld_mod = {
3311     "mld",
3312     mld_modevent,
3313     0
3314 };
3315 DECLARE_MODULE(mld, mld_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
3316