xref: /freebsd/sys/netinet/igmp.c (revision a521f2116473fbd8c09db395518f060a27d02334)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 2007-2009 Bruce Simpson.
5  * Copyright (c) 1988 Stephen Deering.
6  * Copyright (c) 1992, 1993
7  *	The Regents of the University of California.  All rights reserved.
8  *
9  * This code is derived from software contributed to Berkeley by
10  * Stephen Deering of Stanford University.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	@(#)igmp.c	8.1 (Berkeley) 7/19/93
37  */
38 
39 /*
40  * Internet Group Management Protocol (IGMP) routines.
41  * [RFC1112, RFC2236, RFC3376]
42  *
43  * Written by Steve Deering, Stanford, May 1988.
44  * Modified by Rosen Sharma, Stanford, Aug 1994.
45  * Modified by Bill Fenner, Xerox PARC, Feb 1995.
46  * Modified to fully comply to IGMPv2 by Bill Fenner, Oct 1995.
47  * Significantly rewritten for IGMPv3, VIMAGE, and SMP by Bruce Simpson.
48  *
49  * MULTICAST Revision: 3.5.1.4
50  */
51 
52 #include <sys/cdefs.h>
53 __FBSDID("$FreeBSD$");
54 
55 #include "opt_ddb.h"
56 
57 #include <sys/param.h>
58 #include <sys/systm.h>
59 #include <sys/module.h>
60 #include <sys/malloc.h>
61 #include <sys/mbuf.h>
62 #include <sys/socket.h>
63 #include <sys/protosw.h>
64 #include <sys/kernel.h>
65 #include <sys/lock.h>
66 #include <sys/rmlock.h>
67 #include <sys/sysctl.h>
68 #include <sys/ktr.h>
69 #include <sys/condvar.h>
70 
71 #ifdef DDB
72 #include <ddb/ddb.h>
73 #endif
74 
75 #include <net/if.h>
76 #include <net/if_var.h>
77 #include <net/netisr.h>
78 #include <net/vnet.h>
79 
80 #include <netinet/in.h>
81 #include <netinet/in_var.h>
82 #include <netinet/in_systm.h>
83 #include <netinet/ip.h>
84 #include <netinet/ip_var.h>
85 #include <netinet/ip_options.h>
86 #include <netinet/igmp.h>
87 #include <netinet/igmp_var.h>
88 
89 #include <machine/in_cksum.h>
90 
91 #include <security/mac/mac_framework.h>
92 
93 #ifndef KTR_IGMPV3
94 #define KTR_IGMPV3 KTR_INET
95 #endif
96 
97 static struct igmp_ifsoftc *
98 		igi_alloc_locked(struct ifnet *);
99 static void	igi_delete_locked(const struct ifnet *);
100 static void	igmp_dispatch_queue(struct mbufq *, int, const int);
101 static void	igmp_fasttimo_vnet(void);
102 static void	igmp_final_leave(struct in_multi *, struct igmp_ifsoftc *);
103 static int	igmp_handle_state_change(struct in_multi *,
104 		    struct igmp_ifsoftc *);
105 static int	igmp_initial_join(struct in_multi *, struct igmp_ifsoftc *);
106 static int	igmp_input_v1_query(struct ifnet *, const struct ip *,
107 		    const struct igmp *);
108 static int	igmp_input_v2_query(struct ifnet *, const struct ip *,
109 		    const struct igmp *);
110 static int	igmp_input_v3_query(struct ifnet *, const struct ip *,
111 		    /*const*/ struct igmpv3 *);
112 static int	igmp_input_v3_group_query(struct in_multi *,
113 		    struct igmp_ifsoftc *, int, /*const*/ struct igmpv3 *);
114 static int	igmp_input_v1_report(struct ifnet *, /*const*/ struct ip *,
115 		    /*const*/ struct igmp *);
116 static int	igmp_input_v2_report(struct ifnet *, /*const*/ struct ip *,
117 		    /*const*/ struct igmp *);
118 static void	igmp_intr(struct mbuf *);
119 static int	igmp_isgroupreported(const struct in_addr);
120 static struct mbuf *
121 		igmp_ra_alloc(void);
122 #ifdef KTR
123 static char *	igmp_rec_type_to_str(const int);
124 #endif
125 static void	igmp_set_version(struct igmp_ifsoftc *, const int);
126 static void	igmp_slowtimo_vnet(void);
127 static int	igmp_v1v2_queue_report(struct in_multi *, const int);
128 static void	igmp_v1v2_process_group_timer(struct in_multi *, const int);
129 static void	igmp_v1v2_process_querier_timers(struct igmp_ifsoftc *);
130 static void	igmp_v2_update_group(struct in_multi *, const int);
131 static void	igmp_v3_cancel_link_timers(struct igmp_ifsoftc *);
132 static void	igmp_v3_dispatch_general_query(struct igmp_ifsoftc *);
133 static struct mbuf *
134 		igmp_v3_encap_report(struct ifnet *, struct mbuf *);
135 static int	igmp_v3_enqueue_group_record(struct mbufq *,
136 		    struct in_multi *, const int, const int, const int);
137 static int	igmp_v3_enqueue_filter_change(struct mbufq *,
138 		    struct in_multi *);
139 static void	igmp_v3_process_group_timers(struct in_multi_head *,
140 		    struct mbufq *, struct mbufq *, struct in_multi *,
141 		    const int);
142 static int	igmp_v3_merge_state_changes(struct in_multi *,
143 		    struct mbufq *);
144 static void	igmp_v3_suppress_group_record(struct in_multi *);
145 static int	sysctl_igmp_default_version(SYSCTL_HANDLER_ARGS);
146 static int	sysctl_igmp_gsr(SYSCTL_HANDLER_ARGS);
147 static int	sysctl_igmp_ifinfo(SYSCTL_HANDLER_ARGS);
148 static int	sysctl_igmp_stat(SYSCTL_HANDLER_ARGS);
149 
150 static const struct netisr_handler igmp_nh = {
151 	.nh_name = "igmp",
152 	.nh_handler = igmp_intr,
153 	.nh_proto = NETISR_IGMP,
154 	.nh_policy = NETISR_POLICY_SOURCE,
155 };
156 
157 /*
158  * System-wide globals.
159  *
160  * Unlocked access to these is OK, except for the global IGMP output
161  * queue. The IGMP subsystem lock ends up being system-wide for the moment,
162  * because all VIMAGEs have to share a global output queue, as netisrs
163  * themselves are not virtualized.
164  *
165  * Locking:
166  *  * The permitted lock order is: IN_MULTI_LIST_LOCK, IGMP_LOCK, IF_ADDR_LOCK.
167  *    Any may be taken independently; if any are held at the same
168  *    time, the above lock order must be followed.
169  *  * All output is delegated to the netisr.
170  *    Now that Giant has been eliminated, the netisr may be inlined.
171  *  * IN_MULTI_LIST_LOCK covers in_multi.
172  *  * IGMP_LOCK covers igmp_ifsoftc and any global variables in this file,
173  *    including the output queue.
174  *  * IF_ADDR_LOCK covers if_multiaddrs, which is used for a variety of
175  *    per-link state iterators.
176  *  * igmp_ifsoftc is valid as long as PF_INET is attached to the interface,
177  *    therefore it is not refcounted.
178  *    We allow unlocked reads of igmp_ifsoftc when accessed via in_multi.
179  *
180  * Reference counting
181  *  * IGMP acquires its own reference every time an in_multi is passed to
182  *    it and the group is being joined for the first time.
183  *  * IGMP releases its reference(s) on in_multi in a deferred way,
184  *    because the operations which process the release run as part of
185  *    a loop whose control variables are directly affected by the release
186  *    (that, and not recursing on the IF_ADDR_LOCK).
187  *
188  * VIMAGE: Each in_multi corresponds to an ifp, and each ifp corresponds
189  * to a vnet in ifp->if_vnet.
190  *
191  * SMPng: XXX We may potentially race operations on ifma_protospec.
192  * The problem is that we currently lack a clean way of taking the
193  * IF_ADDR_LOCK() between the ifnet and in layers w/o recursing,
194  * as anything which modifies ifma needs to be covered by that lock.
195  * So check for ifma_protospec being NULL before proceeding.
196  */
197 struct mtx		 igmp_mtx;
198 
199 struct mbuf		*m_raopt;		 /* Router Alert option */
200 static MALLOC_DEFINE(M_IGMP, "igmp", "igmp state");
201 
202 /*
203  * VIMAGE-wide globals.
204  *
205  * The IGMPv3 timers themselves need to run per-image, however,
206  * protosw timers run globally (see tcp).
207  * An ifnet can only be in one vimage at a time, and the loopback
208  * ifnet, loif, is itself virtualized.
209  * It would otherwise be possible to seriously hose IGMP state,
210  * and create inconsistencies in upstream multicast routing, if you have
211  * multiple VIMAGEs running on the same link joining different multicast
212  * groups, UNLESS the "primary IP address" is different. This is because
213  * IGMP for IPv4 does not force link-local addresses to be used for each
214  * node, unlike MLD for IPv6.
215  * Obviously the IGMPv3 per-interface state has per-vimage granularity
216  * also as a result.
217  *
218  * FUTURE: Stop using IFP_TO_IA/INADDR_ANY, and use source address selection
219  * policy to control the address used by IGMP on the link.
220  */
221 VNET_DEFINE_STATIC(int, interface_timers_running);	/* IGMPv3 general
222 							 * query response */
223 VNET_DEFINE_STATIC(int, state_change_timers_running);	/* IGMPv3 state-change
224 							 * retransmit */
225 VNET_DEFINE_STATIC(int, current_state_timers_running);	/* IGMPv1/v2 host
226 							 * report; IGMPv3 g/sg
227 							 * query response */
228 
229 #define	V_interface_timers_running	VNET(interface_timers_running)
230 #define	V_state_change_timers_running	VNET(state_change_timers_running)
231 #define	V_current_state_timers_running	VNET(current_state_timers_running)
232 
233 VNET_PCPUSTAT_DEFINE(struct igmpstat, igmpstat);
234 VNET_PCPUSTAT_SYSINIT(igmpstat);
235 VNET_PCPUSTAT_SYSUNINIT(igmpstat);
236 
237 VNET_DEFINE_STATIC(LIST_HEAD(, igmp_ifsoftc), igi_head) =
238     LIST_HEAD_INITIALIZER(igi_head);
239 VNET_DEFINE_STATIC(struct timeval, igmp_gsrdelay) = {10, 0};
240 
241 #define	V_igi_head			VNET(igi_head)
242 #define	V_igmp_gsrdelay			VNET(igmp_gsrdelay)
243 
244 VNET_DEFINE_STATIC(int, igmp_recvifkludge) = 1;
245 VNET_DEFINE_STATIC(int, igmp_sendra) = 1;
246 VNET_DEFINE_STATIC(int, igmp_sendlocal) = 1;
247 VNET_DEFINE_STATIC(int, igmp_v1enable) = 1;
248 VNET_DEFINE_STATIC(int, igmp_v2enable) = 1;
249 VNET_DEFINE_STATIC(int, igmp_legacysupp);
250 VNET_DEFINE_STATIC(int, igmp_default_version) = IGMP_VERSION_3;
251 
252 #define	V_igmp_recvifkludge		VNET(igmp_recvifkludge)
253 #define	V_igmp_sendra			VNET(igmp_sendra)
254 #define	V_igmp_sendlocal		VNET(igmp_sendlocal)
255 #define	V_igmp_v1enable			VNET(igmp_v1enable)
256 #define	V_igmp_v2enable			VNET(igmp_v2enable)
257 #define	V_igmp_legacysupp		VNET(igmp_legacysupp)
258 #define	V_igmp_default_version		VNET(igmp_default_version)
259 
260 /*
261  * Virtualized sysctls.
262  */
263 SYSCTL_PROC(_net_inet_igmp, IGMPCTL_STATS, stats,
264     CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_RW | CTLFLAG_MPSAFE,
265     &VNET_NAME(igmpstat), 0, sysctl_igmp_stat, "S,igmpstat",
266     "IGMP statistics (struct igmpstat, netinet/igmp_var.h)");
267 SYSCTL_INT(_net_inet_igmp, OID_AUTO, recvifkludge, CTLFLAG_VNET | CTLFLAG_RW,
268     &VNET_NAME(igmp_recvifkludge), 0,
269     "Rewrite IGMPv1/v2 reports from 0.0.0.0 to contain subnet address");
270 SYSCTL_INT(_net_inet_igmp, OID_AUTO, sendra, CTLFLAG_VNET | CTLFLAG_RW,
271     &VNET_NAME(igmp_sendra), 0,
272     "Send IP Router Alert option in IGMPv2/v3 messages");
273 SYSCTL_INT(_net_inet_igmp, OID_AUTO, sendlocal, CTLFLAG_VNET | CTLFLAG_RW,
274     &VNET_NAME(igmp_sendlocal), 0,
275     "Send IGMP membership reports for 224.0.0.0/24 groups");
276 SYSCTL_INT(_net_inet_igmp, OID_AUTO, v1enable, CTLFLAG_VNET | CTLFLAG_RW,
277     &VNET_NAME(igmp_v1enable), 0,
278     "Enable backwards compatibility with IGMPv1");
279 SYSCTL_INT(_net_inet_igmp, OID_AUTO, v2enable, CTLFLAG_VNET | CTLFLAG_RW,
280     &VNET_NAME(igmp_v2enable), 0,
281     "Enable backwards compatibility with IGMPv2");
282 SYSCTL_INT(_net_inet_igmp, OID_AUTO, legacysupp, CTLFLAG_VNET | CTLFLAG_RW,
283     &VNET_NAME(igmp_legacysupp), 0,
284     "Allow v1/v2 reports to suppress v3 group responses");
285 SYSCTL_PROC(_net_inet_igmp, OID_AUTO, default_version,
286     CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
287     &VNET_NAME(igmp_default_version), 0, sysctl_igmp_default_version, "I",
288     "Default version of IGMP to run on each interface");
289 SYSCTL_PROC(_net_inet_igmp, OID_AUTO, gsrdelay,
290     CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
291     &VNET_NAME(igmp_gsrdelay.tv_sec), 0, sysctl_igmp_gsr, "I",
292     "Rate limit for IGMPv3 Group-and-Source queries in seconds");
293 
294 /*
295  * Non-virtualized sysctls.
296  */
297 static SYSCTL_NODE(_net_inet_igmp, OID_AUTO, ifinfo,
298     CTLFLAG_RD | CTLFLAG_MPSAFE, sysctl_igmp_ifinfo,
299     "Per-interface IGMPv3 state");
300 
301 static __inline void
302 igmp_save_context(struct mbuf *m, struct ifnet *ifp)
303 {
304 
305 #ifdef VIMAGE
306 	m->m_pkthdr.PH_loc.ptr = ifp->if_vnet;
307 #endif /* VIMAGE */
308 	m->m_pkthdr.rcvif = ifp;
309 	m->m_pkthdr.flowid = ifp->if_index;
310 }
311 
312 static __inline void
313 igmp_scrub_context(struct mbuf *m)
314 {
315 
316 	m->m_pkthdr.PH_loc.ptr = NULL;
317 	m->m_pkthdr.flowid = 0;
318 }
319 
320 /*
321  * Restore context from a queued IGMP output chain.
322  * Return saved ifindex.
323  *
324  * VIMAGE: The assertion is there to make sure that we
325  * actually called CURVNET_SET() with what's in the mbuf chain.
326  */
327 static __inline uint32_t
328 igmp_restore_context(struct mbuf *m)
329 {
330 
331 #ifdef notyet
332 #if defined(VIMAGE) && defined(INVARIANTS)
333 	KASSERT(curvnet == (m->m_pkthdr.PH_loc.ptr),
334 	    ("%s: called when curvnet was not restored", __func__));
335 #endif
336 #endif
337 	return (m->m_pkthdr.flowid);
338 }
339 
340 /*
341  * IGMP statistics.
342  */
343 static int
344 sysctl_igmp_stat(SYSCTL_HANDLER_ARGS)
345 {
346 	struct igmpstat igps0;
347 	int error;
348 	char *p;
349 
350 	error = sysctl_wire_old_buffer(req, sizeof(struct igmpstat));
351 	if (error)
352 		return (error);
353 
354 	if (req->oldptr != NULL) {
355 		if (req->oldlen < sizeof(struct igmpstat))
356 			error = ENOMEM;
357 		else {
358 			/*
359 			 * Copy the counters, and explicitly set the struct's
360 			 * version and length fields.
361 			 */
362 			COUNTER_ARRAY_COPY(VNET(igmpstat), &igps0,
363 			    sizeof(struct igmpstat) / sizeof(uint64_t));
364 			igps0.igps_version = IGPS_VERSION_3;
365 			igps0.igps_len = IGPS_VERSION3_LEN;
366 			error = SYSCTL_OUT(req, &igps0,
367 			    sizeof(struct igmpstat));
368 		}
369 	} else
370 		req->validlen = sizeof(struct igmpstat);
371 	if (error)
372 		goto out;
373 	if (req->newptr != NULL) {
374 		if (req->newlen < sizeof(struct igmpstat))
375 			error = ENOMEM;
376 		else
377 			error = SYSCTL_IN(req, &igps0,
378 			    sizeof(igps0));
379 		if (error)
380 			goto out;
381 		/*
382 		 * igps0 must be "all zero".
383 		 */
384 		p = (char *)&igps0;
385 		while (*p == '\0' && p < (char *)&igps0 + sizeof(igps0))
386 			p++;
387 		if (p != (char *)&igps0 + sizeof(igps0)) {
388 			error = EINVAL;
389 			goto out;
390 		}
391 		COUNTER_ARRAY_ZERO(VNET(igmpstat),
392 		    sizeof(struct igmpstat) / sizeof(uint64_t));
393 	}
394 out:
395 	return (error);
396 }
397 
398 /*
399  * Retrieve or set default IGMP version.
400  *
401  * VIMAGE: Assume curvnet set by caller.
402  * SMPng: NOTE: Serialized by IGMP lock.
403  */
404 static int
405 sysctl_igmp_default_version(SYSCTL_HANDLER_ARGS)
406 {
407 	int	 error;
408 	int	 new;
409 
410 	error = sysctl_wire_old_buffer(req, sizeof(int));
411 	if (error)
412 		return (error);
413 
414 	IGMP_LOCK();
415 
416 	new = V_igmp_default_version;
417 
418 	error = sysctl_handle_int(oidp, &new, 0, req);
419 	if (error || !req->newptr)
420 		goto out_locked;
421 
422 	if (new < IGMP_VERSION_1 || new > IGMP_VERSION_3) {
423 		error = EINVAL;
424 		goto out_locked;
425 	}
426 
427 	CTR2(KTR_IGMPV3, "change igmp_default_version from %d to %d",
428 	     V_igmp_default_version, new);
429 
430 	V_igmp_default_version = new;
431 
432 out_locked:
433 	IGMP_UNLOCK();
434 	return (error);
435 }
436 
437 /*
438  * Retrieve or set threshold between group-source queries in seconds.
439  *
440  * VIMAGE: Assume curvnet set by caller.
441  * SMPng: NOTE: Serialized by IGMP lock.
442  */
443 static int
444 sysctl_igmp_gsr(SYSCTL_HANDLER_ARGS)
445 {
446 	int error;
447 	int i;
448 
449 	error = sysctl_wire_old_buffer(req, sizeof(int));
450 	if (error)
451 		return (error);
452 
453 	IGMP_LOCK();
454 
455 	i = V_igmp_gsrdelay.tv_sec;
456 
457 	error = sysctl_handle_int(oidp, &i, 0, req);
458 	if (error || !req->newptr)
459 		goto out_locked;
460 
461 	if (i < -1 || i >= 60) {
462 		error = EINVAL;
463 		goto out_locked;
464 	}
465 
466 	CTR2(KTR_IGMPV3, "change igmp_gsrdelay from %d to %d",
467 	     V_igmp_gsrdelay.tv_sec, i);
468 	V_igmp_gsrdelay.tv_sec = i;
469 
470 out_locked:
471 	IGMP_UNLOCK();
472 	return (error);
473 }
474 
475 /*
476  * Expose struct igmp_ifsoftc to userland, keyed by ifindex.
477  * For use by ifmcstat(8).
478  *
479  * SMPng: NOTE: Does an unlocked ifindex space read.
480  * VIMAGE: Assume curvnet set by caller. The node handler itself
481  * is not directly virtualized.
482  */
483 static int
484 sysctl_igmp_ifinfo(SYSCTL_HANDLER_ARGS)
485 {
486 	int			*name;
487 	int			 error;
488 	u_int			 namelen;
489 	struct ifnet		*ifp;
490 	struct igmp_ifsoftc	*igi;
491 
492 	name = (int *)arg1;
493 	namelen = arg2;
494 
495 	if (req->newptr != NULL)
496 		return (EPERM);
497 
498 	if (namelen != 1)
499 		return (EINVAL);
500 
501 	error = sysctl_wire_old_buffer(req, sizeof(struct igmp_ifinfo));
502 	if (error)
503 		return (error);
504 
505 	IN_MULTI_LIST_LOCK();
506 	IGMP_LOCK();
507 
508 	if (name[0] <= 0 || name[0] > V_if_index) {
509 		error = ENOENT;
510 		goto out_locked;
511 	}
512 
513 	error = ENOENT;
514 
515 	ifp = ifnet_byindex(name[0]);
516 	if (ifp == NULL)
517 		goto out_locked;
518 
519 	LIST_FOREACH(igi, &V_igi_head, igi_link) {
520 		if (ifp == igi->igi_ifp) {
521 			struct igmp_ifinfo info;
522 
523 			info.igi_version = igi->igi_version;
524 			info.igi_v1_timer = igi->igi_v1_timer;
525 			info.igi_v2_timer = igi->igi_v2_timer;
526 			info.igi_v3_timer = igi->igi_v3_timer;
527 			info.igi_flags = igi->igi_flags;
528 			info.igi_rv = igi->igi_rv;
529 			info.igi_qi = igi->igi_qi;
530 			info.igi_qri = igi->igi_qri;
531 			info.igi_uri = igi->igi_uri;
532 			error = SYSCTL_OUT(req, &info, sizeof(info));
533 			break;
534 		}
535 	}
536 
537 out_locked:
538 	IGMP_UNLOCK();
539 	IN_MULTI_LIST_UNLOCK();
540 	return (error);
541 }
542 
543 /*
544  * Dispatch an entire queue of pending packet chains
545  * using the netisr.
546  * VIMAGE: Assumes the vnet pointer has been set.
547  */
548 static void
549 igmp_dispatch_queue(struct mbufq *mq, int limit, const int loop)
550 {
551 	struct epoch_tracker et;
552 	struct mbuf *m;
553 
554 	NET_EPOCH_ENTER(et);
555 	while ((m = mbufq_dequeue(mq)) != NULL) {
556 		CTR3(KTR_IGMPV3, "%s: dispatch %p from %p", __func__, mq, m);
557 		if (loop)
558 			m->m_flags |= M_IGMP_LOOP;
559 		netisr_dispatch(NETISR_IGMP, m);
560 		if (--limit == 0)
561 			break;
562 	}
563 	NET_EPOCH_EXIT(et);
564 }
565 
566 /*
567  * Filter outgoing IGMP report state by group.
568  *
569  * Reports are ALWAYS suppressed for ALL-HOSTS (224.0.0.1).
570  * If the net.inet.igmp.sendlocal sysctl is 0, then IGMP reports are
571  * disabled for all groups in the 224.0.0.0/24 link-local scope. However,
572  * this may break certain IGMP snooping switches which rely on the old
573  * report behaviour.
574  *
575  * Return zero if the given group is one for which IGMP reports
576  * should be suppressed, or non-zero if reports should be issued.
577  */
578 static __inline int
579 igmp_isgroupreported(const struct in_addr addr)
580 {
581 
582 	if (in_allhosts(addr) ||
583 	    ((!V_igmp_sendlocal && IN_LOCAL_GROUP(ntohl(addr.s_addr)))))
584 		return (0);
585 
586 	return (1);
587 }
588 
589 /*
590  * Construct a Router Alert option to use in outgoing packets.
591  */
592 static struct mbuf *
593 igmp_ra_alloc(void)
594 {
595 	struct mbuf	*m;
596 	struct ipoption	*p;
597 
598 	m = m_get(M_WAITOK, MT_DATA);
599 	p = mtod(m, struct ipoption *);
600 	p->ipopt_dst.s_addr = INADDR_ANY;
601 	p->ipopt_list[0] = (char)IPOPT_RA;	/* Router Alert Option */
602 	p->ipopt_list[1] = 0x04;		/* 4 bytes long */
603 	p->ipopt_list[2] = IPOPT_EOL;		/* End of IP option list */
604 	p->ipopt_list[3] = 0x00;		/* pad byte */
605 	m->m_len = sizeof(p->ipopt_dst) + p->ipopt_list[1];
606 
607 	return (m);
608 }
609 
610 /*
611  * Attach IGMP when PF_INET is attached to an interface.
612  */
613 struct igmp_ifsoftc *
614 igmp_domifattach(struct ifnet *ifp)
615 {
616 	struct igmp_ifsoftc *igi;
617 
618 	CTR3(KTR_IGMPV3, "%s: called for ifp %p(%s)",
619 	    __func__, ifp, ifp->if_xname);
620 
621 	IGMP_LOCK();
622 
623 	igi = igi_alloc_locked(ifp);
624 	if (!(ifp->if_flags & IFF_MULTICAST))
625 		igi->igi_flags |= IGIF_SILENT;
626 
627 	IGMP_UNLOCK();
628 
629 	return (igi);
630 }
631 
632 /*
633  * VIMAGE: assume curvnet set by caller.
634  */
635 static struct igmp_ifsoftc *
636 igi_alloc_locked(/*const*/ struct ifnet *ifp)
637 {
638 	struct igmp_ifsoftc *igi;
639 
640 	IGMP_LOCK_ASSERT();
641 
642 	igi = malloc(sizeof(struct igmp_ifsoftc), M_IGMP, M_NOWAIT|M_ZERO);
643 	if (igi == NULL)
644 		goto out;
645 
646 	igi->igi_ifp = ifp;
647 	igi->igi_version = V_igmp_default_version;
648 	igi->igi_flags = 0;
649 	igi->igi_rv = IGMP_RV_INIT;
650 	igi->igi_qi = IGMP_QI_INIT;
651 	igi->igi_qri = IGMP_QRI_INIT;
652 	igi->igi_uri = IGMP_URI_INIT;
653 	mbufq_init(&igi->igi_gq, IGMP_MAX_RESPONSE_PACKETS);
654 
655 	LIST_INSERT_HEAD(&V_igi_head, igi, igi_link);
656 
657 	CTR2(KTR_IGMPV3, "allocate igmp_ifsoftc for ifp %p(%s)",
658 	     ifp, ifp->if_xname);
659 
660 out:
661 	return (igi);
662 }
663 
664 /*
665  * Hook for ifdetach.
666  *
667  * NOTE: Some finalization tasks need to run before the protocol domain
668  * is detached, but also before the link layer does its cleanup.
669  *
670  * SMPNG: igmp_ifdetach() needs to take IF_ADDR_LOCK().
671  * XXX This is also bitten by unlocked ifma_protospec access.
672  */
673 void
674 igmp_ifdetach(struct ifnet *ifp)
675 {
676 	struct igmp_ifsoftc	*igi;
677 	struct ifmultiaddr	*ifma, *next;
678 	struct in_multi		*inm;
679 	struct in_multi_head inm_free_tmp;
680 	CTR3(KTR_IGMPV3, "%s: called for ifp %p(%s)", __func__, ifp,
681 	    ifp->if_xname);
682 
683 	SLIST_INIT(&inm_free_tmp);
684 	IGMP_LOCK();
685 
686 	igi = ((struct in_ifinfo *)ifp->if_afdata[AF_INET])->ii_igmp;
687 	if (igi->igi_version == IGMP_VERSION_3) {
688 		IF_ADDR_WLOCK(ifp);
689 	restart:
690 		CK_STAILQ_FOREACH_SAFE(ifma, &ifp->if_multiaddrs, ifma_link, next) {
691 			if (ifma->ifma_addr->sa_family != AF_INET ||
692 			    ifma->ifma_protospec == NULL)
693 				continue;
694 			inm = (struct in_multi *)ifma->ifma_protospec;
695 			if (inm->inm_state == IGMP_LEAVING_MEMBER)
696 				inm_rele_locked(&inm_free_tmp, inm);
697 			inm_clear_recorded(inm);
698 			if (__predict_false(ifma_restart)) {
699 				ifma_restart = false;
700 				goto restart;
701 			}
702 		}
703 		IF_ADDR_WUNLOCK(ifp);
704 		inm_release_list_deferred(&inm_free_tmp);
705 	}
706 	IGMP_UNLOCK();
707 
708 }
709 
710 /*
711  * Hook for domifdetach.
712  */
713 void
714 igmp_domifdetach(struct ifnet *ifp)
715 {
716 
717 	CTR3(KTR_IGMPV3, "%s: called for ifp %p(%s)",
718 	    __func__, ifp, ifp->if_xname);
719 
720 	IGMP_LOCK();
721 	igi_delete_locked(ifp);
722 	IGMP_UNLOCK();
723 }
724 
725 static void
726 igi_delete_locked(const struct ifnet *ifp)
727 {
728 	struct igmp_ifsoftc *igi, *tigi;
729 
730 	CTR3(KTR_IGMPV3, "%s: freeing igmp_ifsoftc for ifp %p(%s)",
731 	    __func__, ifp, ifp->if_xname);
732 
733 	IGMP_LOCK_ASSERT();
734 
735 	LIST_FOREACH_SAFE(igi, &V_igi_head, igi_link, tigi) {
736 		if (igi->igi_ifp == ifp) {
737 			/*
738 			 * Free deferred General Query responses.
739 			 */
740 			mbufq_drain(&igi->igi_gq);
741 
742 			LIST_REMOVE(igi, igi_link);
743 			free(igi, M_IGMP);
744 			return;
745 		}
746 	}
747 }
748 
749 /*
750  * Process a received IGMPv1 query.
751  * Return non-zero if the message should be dropped.
752  *
753  * VIMAGE: The curvnet pointer is derived from the input ifp.
754  */
755 static int
756 igmp_input_v1_query(struct ifnet *ifp, const struct ip *ip,
757     const struct igmp *igmp)
758 {
759 	struct ifmultiaddr	*ifma;
760 	struct igmp_ifsoftc	*igi;
761 	struct in_multi		*inm;
762 
763 	NET_EPOCH_ASSERT();
764 
765 	/*
766 	 * IGMPv1 Host Mmembership Queries SHOULD always be addressed to
767 	 * 224.0.0.1. They are always treated as General Queries.
768 	 * igmp_group is always ignored. Do not drop it as a userland
769 	 * daemon may wish to see it.
770 	 * XXX SMPng: unlocked increments in igmpstat assumed atomic.
771 	 */
772 	if (!in_allhosts(ip->ip_dst) || !in_nullhost(igmp->igmp_group)) {
773 		IGMPSTAT_INC(igps_rcv_badqueries);
774 		return (0);
775 	}
776 	IGMPSTAT_INC(igps_rcv_gen_queries);
777 
778 	IN_MULTI_LIST_LOCK();
779 	IGMP_LOCK();
780 
781 	igi = ((struct in_ifinfo *)ifp->if_afdata[AF_INET])->ii_igmp;
782 	KASSERT(igi != NULL, ("%s: no igmp_ifsoftc for ifp %p", __func__, ifp));
783 
784 	if (igi->igi_flags & IGIF_LOOPBACK) {
785 		CTR2(KTR_IGMPV3, "ignore v1 query on IGIF_LOOPBACK ifp %p(%s)",
786 		    ifp, ifp->if_xname);
787 		goto out_locked;
788 	}
789 
790 	/*
791 	 * Switch to IGMPv1 host compatibility mode.
792 	 */
793 	igmp_set_version(igi, IGMP_VERSION_1);
794 
795 	CTR2(KTR_IGMPV3, "process v1 query on ifp %p(%s)", ifp, ifp->if_xname);
796 
797 	/*
798 	 * Start the timers in all of our group records
799 	 * for the interface on which the query arrived,
800 	 * except those which are already running.
801 	 */
802 	CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
803 		if (ifma->ifma_addr->sa_family != AF_INET ||
804 		    ifma->ifma_protospec == NULL)
805 			continue;
806 		inm = (struct in_multi *)ifma->ifma_protospec;
807 		if (inm->inm_timer != 0)
808 			continue;
809 		switch (inm->inm_state) {
810 		case IGMP_NOT_MEMBER:
811 		case IGMP_SILENT_MEMBER:
812 			break;
813 		case IGMP_G_QUERY_PENDING_MEMBER:
814 		case IGMP_SG_QUERY_PENDING_MEMBER:
815 		case IGMP_REPORTING_MEMBER:
816 		case IGMP_IDLE_MEMBER:
817 		case IGMP_LAZY_MEMBER:
818 		case IGMP_SLEEPING_MEMBER:
819 		case IGMP_AWAKENING_MEMBER:
820 			inm->inm_state = IGMP_REPORTING_MEMBER;
821 			inm->inm_timer = IGMP_RANDOM_DELAY(
822 			    IGMP_V1V2_MAX_RI * PR_FASTHZ);
823 			V_current_state_timers_running = 1;
824 			break;
825 		case IGMP_LEAVING_MEMBER:
826 			break;
827 		}
828 	}
829 
830 out_locked:
831 	IGMP_UNLOCK();
832 	IN_MULTI_LIST_UNLOCK();
833 
834 	return (0);
835 }
836 
837 /*
838  * Process a received IGMPv2 general or group-specific query.
839  */
840 static int
841 igmp_input_v2_query(struct ifnet *ifp, const struct ip *ip,
842     const struct igmp *igmp)
843 {
844 	struct ifmultiaddr	*ifma;
845 	struct igmp_ifsoftc	*igi;
846 	struct in_multi		*inm;
847 	int			 is_general_query;
848 	uint16_t		 timer;
849 
850 	NET_EPOCH_ASSERT();
851 
852 	is_general_query = 0;
853 
854 	/*
855 	 * Validate address fields upfront.
856 	 * XXX SMPng: unlocked increments in igmpstat assumed atomic.
857 	 */
858 	if (in_nullhost(igmp->igmp_group)) {
859 		/*
860 		 * IGMPv2 General Query.
861 		 * If this was not sent to the all-hosts group, ignore it.
862 		 */
863 		if (!in_allhosts(ip->ip_dst))
864 			return (0);
865 		IGMPSTAT_INC(igps_rcv_gen_queries);
866 		is_general_query = 1;
867 	} else {
868 		/* IGMPv2 Group-Specific Query. */
869 		IGMPSTAT_INC(igps_rcv_group_queries);
870 	}
871 
872 	IN_MULTI_LIST_LOCK();
873 	IGMP_LOCK();
874 
875 	igi = ((struct in_ifinfo *)ifp->if_afdata[AF_INET])->ii_igmp;
876 	KASSERT(igi != NULL, ("%s: no igmp_ifsoftc for ifp %p", __func__, ifp));
877 
878 	if (igi->igi_flags & IGIF_LOOPBACK) {
879 		CTR2(KTR_IGMPV3, "ignore v2 query on IGIF_LOOPBACK ifp %p(%s)",
880 		    ifp, ifp->if_xname);
881 		goto out_locked;
882 	}
883 
884 	/*
885 	 * Ignore v2 query if in v1 Compatibility Mode.
886 	 */
887 	if (igi->igi_version == IGMP_VERSION_1)
888 		goto out_locked;
889 
890 	igmp_set_version(igi, IGMP_VERSION_2);
891 
892 	timer = igmp->igmp_code * PR_FASTHZ / IGMP_TIMER_SCALE;
893 	if (timer == 0)
894 		timer = 1;
895 
896 	if (is_general_query) {
897 		/*
898 		 * For each reporting group joined on this
899 		 * interface, kick the report timer.
900 		 */
901 		CTR2(KTR_IGMPV3, "process v2 general query on ifp %p(%s)",
902 		    ifp, ifp->if_xname);
903 		CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
904 			if (ifma->ifma_addr->sa_family != AF_INET ||
905 			    ifma->ifma_protospec == NULL)
906 				continue;
907 			inm = (struct in_multi *)ifma->ifma_protospec;
908 			igmp_v2_update_group(inm, timer);
909 		}
910 	} else {
911 		/*
912 		 * Group-specific IGMPv2 query, we need only
913 		 * look up the single group to process it.
914 		 */
915 		inm = inm_lookup(ifp, igmp->igmp_group);
916 		if (inm != NULL) {
917 			CTR3(KTR_IGMPV3,
918 			    "process v2 query 0x%08x on ifp %p(%s)",
919 			    ntohl(igmp->igmp_group.s_addr), ifp, ifp->if_xname);
920 			igmp_v2_update_group(inm, timer);
921 		}
922 	}
923 
924 out_locked:
925 	IGMP_UNLOCK();
926 	IN_MULTI_LIST_UNLOCK();
927 
928 	return (0);
929 }
930 
931 /*
932  * Update the report timer on a group in response to an IGMPv2 query.
933  *
934  * If we are becoming the reporting member for this group, start the timer.
935  * If we already are the reporting member for this group, and timer is
936  * below the threshold, reset it.
937  *
938  * We may be updating the group for the first time since we switched
939  * to IGMPv3. If we are, then we must clear any recorded source lists,
940  * and transition to REPORTING state; the group timer is overloaded
941  * for group and group-source query responses.
942  *
943  * Unlike IGMPv3, the delay per group should be jittered
944  * to avoid bursts of IGMPv2 reports.
945  */
946 static void
947 igmp_v2_update_group(struct in_multi *inm, const int timer)
948 {
949 
950 	CTR4(KTR_IGMPV3, "0x%08x: %s/%s timer=%d", __func__,
951 	    ntohl(inm->inm_addr.s_addr), inm->inm_ifp->if_xname, timer);
952 
953 	IN_MULTI_LIST_LOCK_ASSERT();
954 
955 	switch (inm->inm_state) {
956 	case IGMP_NOT_MEMBER:
957 	case IGMP_SILENT_MEMBER:
958 		break;
959 	case IGMP_REPORTING_MEMBER:
960 		if (inm->inm_timer != 0 &&
961 		    inm->inm_timer <= timer) {
962 			CTR1(KTR_IGMPV3, "%s: REPORTING and timer running, "
963 			    "skipping.", __func__);
964 			break;
965 		}
966 		/* FALLTHROUGH */
967 	case IGMP_SG_QUERY_PENDING_MEMBER:
968 	case IGMP_G_QUERY_PENDING_MEMBER:
969 	case IGMP_IDLE_MEMBER:
970 	case IGMP_LAZY_MEMBER:
971 	case IGMP_AWAKENING_MEMBER:
972 		CTR1(KTR_IGMPV3, "%s: ->REPORTING", __func__);
973 		inm->inm_state = IGMP_REPORTING_MEMBER;
974 		inm->inm_timer = IGMP_RANDOM_DELAY(timer);
975 		V_current_state_timers_running = 1;
976 		break;
977 	case IGMP_SLEEPING_MEMBER:
978 		CTR1(KTR_IGMPV3, "%s: ->AWAKENING", __func__);
979 		inm->inm_state = IGMP_AWAKENING_MEMBER;
980 		break;
981 	case IGMP_LEAVING_MEMBER:
982 		break;
983 	}
984 }
985 
986 /*
987  * Process a received IGMPv3 general, group-specific or
988  * group-and-source-specific query.
989  * Assumes m has already been pulled up to the full IGMP message length.
990  * Return 0 if successful, otherwise an appropriate error code is returned.
991  */
992 static int
993 igmp_input_v3_query(struct ifnet *ifp, const struct ip *ip,
994     /*const*/ struct igmpv3 *igmpv3)
995 {
996 	struct igmp_ifsoftc	*igi;
997 	struct in_multi		*inm;
998 	int			 is_general_query;
999 	uint32_t		 maxresp, nsrc, qqi;
1000 	uint16_t		 timer;
1001 	uint8_t			 qrv;
1002 
1003 	is_general_query = 0;
1004 
1005 	CTR2(KTR_IGMPV3, "process v3 query on ifp %p(%s)", ifp, ifp->if_xname);
1006 
1007 	maxresp = igmpv3->igmp_code;	/* in 1/10ths of a second */
1008 	if (maxresp >= 128) {
1009 		maxresp = IGMP_MANT(igmpv3->igmp_code) <<
1010 			  (IGMP_EXP(igmpv3->igmp_code) + 3);
1011 	}
1012 
1013 	/*
1014 	 * Robustness must never be less than 2 for on-wire IGMPv3.
1015 	 * FUTURE: Check if ifp has IGIF_LOOPBACK set, as we will make
1016 	 * an exception for interfaces whose IGMPv3 state changes
1017 	 * are redirected to loopback (e.g. MANET).
1018 	 */
1019 	qrv = IGMP_QRV(igmpv3->igmp_misc);
1020 	if (qrv < 2) {
1021 		CTR3(KTR_IGMPV3, "%s: clamping qrv %d to %d", __func__,
1022 		    qrv, IGMP_RV_INIT);
1023 		qrv = IGMP_RV_INIT;
1024 	}
1025 
1026 	qqi = igmpv3->igmp_qqi;
1027 	if (qqi >= 128) {
1028 		qqi = IGMP_MANT(igmpv3->igmp_qqi) <<
1029 		     (IGMP_EXP(igmpv3->igmp_qqi) + 3);
1030 	}
1031 
1032 	timer = maxresp * PR_FASTHZ / IGMP_TIMER_SCALE;
1033 	if (timer == 0)
1034 		timer = 1;
1035 
1036 	nsrc = ntohs(igmpv3->igmp_numsrc);
1037 
1038 	/*
1039 	 * Validate address fields and versions upfront before
1040 	 * accepting v3 query.
1041 	 * XXX SMPng: Unlocked access to igmpstat counters here.
1042 	 */
1043 	if (in_nullhost(igmpv3->igmp_group)) {
1044 		/*
1045 		 * IGMPv3 General Query.
1046 		 *
1047 		 * General Queries SHOULD be directed to 224.0.0.1.
1048 		 * A general query with a source list has undefined
1049 		 * behaviour; discard it.
1050 		 */
1051 		IGMPSTAT_INC(igps_rcv_gen_queries);
1052 		if (!in_allhosts(ip->ip_dst) || nsrc > 0) {
1053 			IGMPSTAT_INC(igps_rcv_badqueries);
1054 			return (0);
1055 		}
1056 		is_general_query = 1;
1057 	} else {
1058 		/* Group or group-source specific query. */
1059 		if (nsrc == 0)
1060 			IGMPSTAT_INC(igps_rcv_group_queries);
1061 		else
1062 			IGMPSTAT_INC(igps_rcv_gsr_queries);
1063 	}
1064 
1065 	IN_MULTI_LIST_LOCK();
1066 	IGMP_LOCK();
1067 
1068 	igi = ((struct in_ifinfo *)ifp->if_afdata[AF_INET])->ii_igmp;
1069 	KASSERT(igi != NULL, ("%s: no igmp_ifsoftc for ifp %p", __func__, ifp));
1070 
1071 	if (igi->igi_flags & IGIF_LOOPBACK) {
1072 		CTR2(KTR_IGMPV3, "ignore v3 query on IGIF_LOOPBACK ifp %p(%s)",
1073 		    ifp, ifp->if_xname);
1074 		goto out_locked;
1075 	}
1076 
1077 	/*
1078 	 * Discard the v3 query if we're in Compatibility Mode.
1079 	 * The RFC is not obviously worded that hosts need to stay in
1080 	 * compatibility mode until the Old Version Querier Present
1081 	 * timer expires.
1082 	 */
1083 	if (igi->igi_version != IGMP_VERSION_3) {
1084 		CTR3(KTR_IGMPV3, "ignore v3 query in v%d mode on ifp %p(%s)",
1085 		    igi->igi_version, ifp, ifp->if_xname);
1086 		goto out_locked;
1087 	}
1088 
1089 	igmp_set_version(igi, IGMP_VERSION_3);
1090 	igi->igi_rv = qrv;
1091 	igi->igi_qi = qqi;
1092 	igi->igi_qri = maxresp;
1093 
1094 	CTR4(KTR_IGMPV3, "%s: qrv %d qi %d qri %d", __func__, qrv, qqi,
1095 	    maxresp);
1096 
1097 	if (is_general_query) {
1098 		/*
1099 		 * Schedule a current-state report on this ifp for
1100 		 * all groups, possibly containing source lists.
1101 		 * If there is a pending General Query response
1102 		 * scheduled earlier than the selected delay, do
1103 		 * not schedule any other reports.
1104 		 * Otherwise, reset the interface timer.
1105 		 */
1106 		CTR2(KTR_IGMPV3, "process v3 general query on ifp %p(%s)",
1107 		    ifp, ifp->if_xname);
1108 		if (igi->igi_v3_timer == 0 || igi->igi_v3_timer >= timer) {
1109 			igi->igi_v3_timer = IGMP_RANDOM_DELAY(timer);
1110 			V_interface_timers_running = 1;
1111 		}
1112 	} else {
1113 		/*
1114 		 * Group-source-specific queries are throttled on
1115 		 * a per-group basis to defeat denial-of-service attempts.
1116 		 * Queries for groups we are not a member of on this
1117 		 * link are simply ignored.
1118 		 */
1119 		inm = inm_lookup(ifp, igmpv3->igmp_group);
1120 		if (inm == NULL)
1121 			goto out_locked;
1122 		if (nsrc > 0) {
1123 			if (!ratecheck(&inm->inm_lastgsrtv,
1124 			    &V_igmp_gsrdelay)) {
1125 				CTR1(KTR_IGMPV3, "%s: GS query throttled.",
1126 				    __func__);
1127 				IGMPSTAT_INC(igps_drop_gsr_queries);
1128 				goto out_locked;
1129 			}
1130 		}
1131 		CTR3(KTR_IGMPV3, "process v3 0x%08x query on ifp %p(%s)",
1132 		     ntohl(igmpv3->igmp_group.s_addr), ifp, ifp->if_xname);
1133 		/*
1134 		 * If there is a pending General Query response
1135 		 * scheduled sooner than the selected delay, no
1136 		 * further report need be scheduled.
1137 		 * Otherwise, prepare to respond to the
1138 		 * group-specific or group-and-source query.
1139 		 */
1140 		if (igi->igi_v3_timer == 0 || igi->igi_v3_timer >= timer)
1141 			igmp_input_v3_group_query(inm, igi, timer, igmpv3);
1142 	}
1143 
1144 out_locked:
1145 	IGMP_UNLOCK();
1146 	IN_MULTI_LIST_UNLOCK();
1147 
1148 	return (0);
1149 }
1150 
1151 /*
1152  * Process a received IGMPv3 group-specific or group-and-source-specific
1153  * query.
1154  * Return <0 if any error occurred. Currently this is ignored.
1155  */
1156 static int
1157 igmp_input_v3_group_query(struct in_multi *inm, struct igmp_ifsoftc *igi,
1158     int timer, /*const*/ struct igmpv3 *igmpv3)
1159 {
1160 	int			 retval;
1161 	uint16_t		 nsrc;
1162 
1163 	IN_MULTI_LIST_LOCK_ASSERT();
1164 	IGMP_LOCK_ASSERT();
1165 
1166 	retval = 0;
1167 
1168 	switch (inm->inm_state) {
1169 	case IGMP_NOT_MEMBER:
1170 	case IGMP_SILENT_MEMBER:
1171 	case IGMP_SLEEPING_MEMBER:
1172 	case IGMP_LAZY_MEMBER:
1173 	case IGMP_AWAKENING_MEMBER:
1174 	case IGMP_IDLE_MEMBER:
1175 	case IGMP_LEAVING_MEMBER:
1176 		return (retval);
1177 		break;
1178 	case IGMP_REPORTING_MEMBER:
1179 	case IGMP_G_QUERY_PENDING_MEMBER:
1180 	case IGMP_SG_QUERY_PENDING_MEMBER:
1181 		break;
1182 	}
1183 
1184 	nsrc = ntohs(igmpv3->igmp_numsrc);
1185 
1186 	/*
1187 	 * Deal with group-specific queries upfront.
1188 	 * If any group query is already pending, purge any recorded
1189 	 * source-list state if it exists, and schedule a query response
1190 	 * for this group-specific query.
1191 	 */
1192 	if (nsrc == 0) {
1193 		if (inm->inm_state == IGMP_G_QUERY_PENDING_MEMBER ||
1194 		    inm->inm_state == IGMP_SG_QUERY_PENDING_MEMBER) {
1195 			inm_clear_recorded(inm);
1196 			timer = min(inm->inm_timer, timer);
1197 		}
1198 		inm->inm_state = IGMP_G_QUERY_PENDING_MEMBER;
1199 		inm->inm_timer = IGMP_RANDOM_DELAY(timer);
1200 		V_current_state_timers_running = 1;
1201 		return (retval);
1202 	}
1203 
1204 	/*
1205 	 * Deal with the case where a group-and-source-specific query has
1206 	 * been received but a group-specific query is already pending.
1207 	 */
1208 	if (inm->inm_state == IGMP_G_QUERY_PENDING_MEMBER) {
1209 		timer = min(inm->inm_timer, timer);
1210 		inm->inm_timer = IGMP_RANDOM_DELAY(timer);
1211 		V_current_state_timers_running = 1;
1212 		return (retval);
1213 	}
1214 
1215 	/*
1216 	 * Finally, deal with the case where a group-and-source-specific
1217 	 * query has been received, where a response to a previous g-s-r
1218 	 * query exists, or none exists.
1219 	 * In this case, we need to parse the source-list which the Querier
1220 	 * has provided us with and check if we have any source list filter
1221 	 * entries at T1 for these sources. If we do not, there is no need
1222 	 * schedule a report and the query may be dropped.
1223 	 * If we do, we must record them and schedule a current-state
1224 	 * report for those sources.
1225 	 * FIXME: Handling source lists larger than 1 mbuf requires that
1226 	 * we pass the mbuf chain pointer down to this function, and use
1227 	 * m_getptr() to walk the chain.
1228 	 */
1229 	if (inm->inm_nsrc > 0) {
1230 		const struct in_addr	*ap;
1231 		int			 i, nrecorded;
1232 
1233 		ap = (const struct in_addr *)(igmpv3 + 1);
1234 		nrecorded = 0;
1235 		for (i = 0; i < nsrc; i++, ap++) {
1236 			retval = inm_record_source(inm, ap->s_addr);
1237 			if (retval < 0)
1238 				break;
1239 			nrecorded += retval;
1240 		}
1241 		if (nrecorded > 0) {
1242 			CTR1(KTR_IGMPV3,
1243 			    "%s: schedule response to SG query", __func__);
1244 			inm->inm_state = IGMP_SG_QUERY_PENDING_MEMBER;
1245 			inm->inm_timer = IGMP_RANDOM_DELAY(timer);
1246 			V_current_state_timers_running = 1;
1247 		}
1248 	}
1249 
1250 	return (retval);
1251 }
1252 
1253 /*
1254  * Process a received IGMPv1 host membership report.
1255  *
1256  * NOTE: 0.0.0.0 workaround breaks const correctness.
1257  */
1258 static int
1259 igmp_input_v1_report(struct ifnet *ifp, /*const*/ struct ip *ip,
1260     /*const*/ struct igmp *igmp)
1261 {
1262 	struct rm_priotracker in_ifa_tracker;
1263 	struct in_ifaddr *ia;
1264 	struct in_multi *inm;
1265 
1266 	IGMPSTAT_INC(igps_rcv_reports);
1267 
1268 	if (ifp->if_flags & IFF_LOOPBACK)
1269 		return (0);
1270 
1271 	if (!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr)) ||
1272 	    !in_hosteq(igmp->igmp_group, ip->ip_dst)) {
1273 		IGMPSTAT_INC(igps_rcv_badreports);
1274 		return (EINVAL);
1275 	}
1276 
1277 	/*
1278 	 * RFC 3376, Section 4.2.13, 9.2, 9.3:
1279 	 * Booting clients may use the source address 0.0.0.0. Some
1280 	 * IGMP daemons may not know how to use IP_RECVIF to determine
1281 	 * the interface upon which this message was received.
1282 	 * Replace 0.0.0.0 with the subnet address if told to do so.
1283 	 */
1284 	if (V_igmp_recvifkludge && in_nullhost(ip->ip_src)) {
1285 		IFP_TO_IA(ifp, ia, &in_ifa_tracker);
1286 		if (ia != NULL)
1287 			ip->ip_src.s_addr = htonl(ia->ia_subnet);
1288 	}
1289 
1290 	CTR3(KTR_IGMPV3, "process v1 report 0x%08x on ifp %p(%s)",
1291 	     ntohl(igmp->igmp_group.s_addr), ifp, ifp->if_xname);
1292 
1293 	/*
1294 	 * IGMPv1 report suppression.
1295 	 * If we are a member of this group, and our membership should be
1296 	 * reported, stop our group timer and transition to the 'lazy' state.
1297 	 */
1298 	IN_MULTI_LIST_LOCK();
1299 	inm = inm_lookup(ifp, igmp->igmp_group);
1300 	if (inm != NULL) {
1301 		struct igmp_ifsoftc *igi;
1302 
1303 		igi = inm->inm_igi;
1304 		if (igi == NULL) {
1305 			KASSERT(igi != NULL,
1306 			    ("%s: no igi for ifp %p", __func__, ifp));
1307 			goto out_locked;
1308 		}
1309 
1310 		IGMPSTAT_INC(igps_rcv_ourreports);
1311 
1312 		/*
1313 		 * If we are in IGMPv3 host mode, do not allow the
1314 		 * other host's IGMPv1 report to suppress our reports
1315 		 * unless explicitly configured to do so.
1316 		 */
1317 		if (igi->igi_version == IGMP_VERSION_3) {
1318 			if (V_igmp_legacysupp)
1319 				igmp_v3_suppress_group_record(inm);
1320 			goto out_locked;
1321 		}
1322 
1323 		inm->inm_timer = 0;
1324 
1325 		switch (inm->inm_state) {
1326 		case IGMP_NOT_MEMBER:
1327 		case IGMP_SILENT_MEMBER:
1328 			break;
1329 		case IGMP_IDLE_MEMBER:
1330 		case IGMP_LAZY_MEMBER:
1331 		case IGMP_AWAKENING_MEMBER:
1332 			CTR3(KTR_IGMPV3,
1333 			    "report suppressed for 0x%08x on ifp %p(%s)",
1334 			    ntohl(igmp->igmp_group.s_addr), ifp,
1335 			    ifp->if_xname);
1336 		case IGMP_SLEEPING_MEMBER:
1337 			inm->inm_state = IGMP_SLEEPING_MEMBER;
1338 			break;
1339 		case IGMP_REPORTING_MEMBER:
1340 			CTR3(KTR_IGMPV3,
1341 			    "report suppressed for 0x%08x on ifp %p(%s)",
1342 			    ntohl(igmp->igmp_group.s_addr), ifp,
1343 			    ifp->if_xname);
1344 			if (igi->igi_version == IGMP_VERSION_1)
1345 				inm->inm_state = IGMP_LAZY_MEMBER;
1346 			else if (igi->igi_version == IGMP_VERSION_2)
1347 				inm->inm_state = IGMP_SLEEPING_MEMBER;
1348 			break;
1349 		case IGMP_G_QUERY_PENDING_MEMBER:
1350 		case IGMP_SG_QUERY_PENDING_MEMBER:
1351 		case IGMP_LEAVING_MEMBER:
1352 			break;
1353 		}
1354 	}
1355 
1356 out_locked:
1357 	IN_MULTI_LIST_UNLOCK();
1358 
1359 	return (0);
1360 }
1361 
1362 /*
1363  * Process a received IGMPv2 host membership report.
1364  *
1365  * NOTE: 0.0.0.0 workaround breaks const correctness.
1366  */
1367 static int
1368 igmp_input_v2_report(struct ifnet *ifp, /*const*/ struct ip *ip,
1369     /*const*/ struct igmp *igmp)
1370 {
1371 	struct rm_priotracker in_ifa_tracker;
1372 	struct in_ifaddr *ia;
1373 	struct in_multi *inm;
1374 
1375 	/*
1376 	 * Make sure we don't hear our own membership report.  Fast
1377 	 * leave requires knowing that we are the only member of a
1378 	 * group.
1379 	 */
1380 	IFP_TO_IA(ifp, ia, &in_ifa_tracker);
1381 	if (ia != NULL && in_hosteq(ip->ip_src, IA_SIN(ia)->sin_addr)) {
1382 		return (0);
1383 	}
1384 
1385 	IGMPSTAT_INC(igps_rcv_reports);
1386 
1387 	if (ifp->if_flags & IFF_LOOPBACK) {
1388 		return (0);
1389 	}
1390 
1391 	if (!IN_MULTICAST(ntohl(igmp->igmp_group.s_addr)) ||
1392 	    !in_hosteq(igmp->igmp_group, ip->ip_dst)) {
1393 		IGMPSTAT_INC(igps_rcv_badreports);
1394 		return (EINVAL);
1395 	}
1396 
1397 	/*
1398 	 * RFC 3376, Section 4.2.13, 9.2, 9.3:
1399 	 * Booting clients may use the source address 0.0.0.0. Some
1400 	 * IGMP daemons may not know how to use IP_RECVIF to determine
1401 	 * the interface upon which this message was received.
1402 	 * Replace 0.0.0.0 with the subnet address if told to do so.
1403 	 */
1404 	if (V_igmp_recvifkludge && in_nullhost(ip->ip_src)) {
1405 		if (ia != NULL)
1406 			ip->ip_src.s_addr = htonl(ia->ia_subnet);
1407 	}
1408 
1409 	CTR3(KTR_IGMPV3, "process v2 report 0x%08x on ifp %p(%s)",
1410 	     ntohl(igmp->igmp_group.s_addr), ifp, ifp->if_xname);
1411 
1412 	/*
1413 	 * IGMPv2 report suppression.
1414 	 * If we are a member of this group, and our membership should be
1415 	 * reported, and our group timer is pending or about to be reset,
1416 	 * stop our group timer by transitioning to the 'lazy' state.
1417 	 */
1418 	IN_MULTI_LIST_LOCK();
1419 	inm = inm_lookup(ifp, igmp->igmp_group);
1420 	if (inm != NULL) {
1421 		struct igmp_ifsoftc *igi;
1422 
1423 		igi = inm->inm_igi;
1424 		KASSERT(igi != NULL, ("%s: no igi for ifp %p", __func__, ifp));
1425 
1426 		IGMPSTAT_INC(igps_rcv_ourreports);
1427 
1428 		/*
1429 		 * If we are in IGMPv3 host mode, do not allow the
1430 		 * other host's IGMPv1 report to suppress our reports
1431 		 * unless explicitly configured to do so.
1432 		 */
1433 		if (igi->igi_version == IGMP_VERSION_3) {
1434 			if (V_igmp_legacysupp)
1435 				igmp_v3_suppress_group_record(inm);
1436 			goto out_locked;
1437 		}
1438 
1439 		inm->inm_timer = 0;
1440 
1441 		switch (inm->inm_state) {
1442 		case IGMP_NOT_MEMBER:
1443 		case IGMP_SILENT_MEMBER:
1444 		case IGMP_SLEEPING_MEMBER:
1445 			break;
1446 		case IGMP_REPORTING_MEMBER:
1447 		case IGMP_IDLE_MEMBER:
1448 		case IGMP_AWAKENING_MEMBER:
1449 			CTR3(KTR_IGMPV3,
1450 			    "report suppressed for 0x%08x on ifp %p(%s)",
1451 			    ntohl(igmp->igmp_group.s_addr), ifp, ifp->if_xname);
1452 		case IGMP_LAZY_MEMBER:
1453 			inm->inm_state = IGMP_LAZY_MEMBER;
1454 			break;
1455 		case IGMP_G_QUERY_PENDING_MEMBER:
1456 		case IGMP_SG_QUERY_PENDING_MEMBER:
1457 		case IGMP_LEAVING_MEMBER:
1458 			break;
1459 		}
1460 	}
1461 
1462 out_locked:
1463 	IN_MULTI_LIST_UNLOCK();
1464 
1465 	return (0);
1466 }
1467 
1468 int
1469 igmp_input(struct mbuf **mp, int *offp, int proto)
1470 {
1471 	int iphlen;
1472 	struct ifnet *ifp;
1473 	struct igmp *igmp;
1474 	struct ip *ip;
1475 	struct mbuf *m;
1476 	int igmplen;
1477 	int minlen;
1478 	int queryver;
1479 
1480 	CTR3(KTR_IGMPV3, "%s: called w/mbuf (%p,%d)", __func__, *mp, *offp);
1481 
1482 	m = *mp;
1483 	ifp = m->m_pkthdr.rcvif;
1484 	*mp = NULL;
1485 
1486 	IGMPSTAT_INC(igps_rcv_total);
1487 
1488 	ip = mtod(m, struct ip *);
1489 	iphlen = *offp;
1490 	igmplen = ntohs(ip->ip_len) - iphlen;
1491 
1492 	/*
1493 	 * Validate lengths.
1494 	 */
1495 	if (igmplen < IGMP_MINLEN) {
1496 		IGMPSTAT_INC(igps_rcv_tooshort);
1497 		m_freem(m);
1498 		return (IPPROTO_DONE);
1499 	}
1500 
1501 	/*
1502 	 * Always pullup to the minimum size for v1/v2 or v3
1503 	 * to amortize calls to m_pullup().
1504 	 */
1505 	minlen = iphlen;
1506 	if (igmplen >= IGMP_V3_QUERY_MINLEN)
1507 		minlen += IGMP_V3_QUERY_MINLEN;
1508 	else
1509 		minlen += IGMP_MINLEN;
1510 	if ((!M_WRITABLE(m) || m->m_len < minlen) &&
1511 	    (m = m_pullup(m, minlen)) == NULL) {
1512 		IGMPSTAT_INC(igps_rcv_tooshort);
1513 		return (IPPROTO_DONE);
1514 	}
1515 	ip = mtod(m, struct ip *);
1516 
1517 	/*
1518 	 * Validate checksum.
1519 	 */
1520 	m->m_data += iphlen;
1521 	m->m_len -= iphlen;
1522 	igmp = mtod(m, struct igmp *);
1523 	if (in_cksum(m, igmplen)) {
1524 		IGMPSTAT_INC(igps_rcv_badsum);
1525 		m_freem(m);
1526 		return (IPPROTO_DONE);
1527 	}
1528 	m->m_data -= iphlen;
1529 	m->m_len += iphlen;
1530 
1531 	/*
1532 	 * IGMP control traffic is link-scope, and must have a TTL of 1.
1533 	 * DVMRP traffic (e.g. mrinfo, mtrace) is an exception;
1534 	 * probe packets may come from beyond the LAN.
1535 	 */
1536 	if (igmp->igmp_type != IGMP_DVMRP && ip->ip_ttl != 1) {
1537 		IGMPSTAT_INC(igps_rcv_badttl);
1538 		m_freem(m);
1539 		return (IPPROTO_DONE);
1540 	}
1541 
1542 	switch (igmp->igmp_type) {
1543 	case IGMP_HOST_MEMBERSHIP_QUERY:
1544 		if (igmplen == IGMP_MINLEN) {
1545 			if (igmp->igmp_code == 0)
1546 				queryver = IGMP_VERSION_1;
1547 			else
1548 				queryver = IGMP_VERSION_2;
1549 		} else if (igmplen >= IGMP_V3_QUERY_MINLEN) {
1550 			queryver = IGMP_VERSION_3;
1551 		} else {
1552 			IGMPSTAT_INC(igps_rcv_tooshort);
1553 			m_freem(m);
1554 			return (IPPROTO_DONE);
1555 		}
1556 
1557 		switch (queryver) {
1558 		case IGMP_VERSION_1:
1559 			IGMPSTAT_INC(igps_rcv_v1v2_queries);
1560 			if (!V_igmp_v1enable)
1561 				break;
1562 			if (igmp_input_v1_query(ifp, ip, igmp) != 0) {
1563 				m_freem(m);
1564 				return (IPPROTO_DONE);
1565 			}
1566 			break;
1567 
1568 		case IGMP_VERSION_2:
1569 			IGMPSTAT_INC(igps_rcv_v1v2_queries);
1570 			if (!V_igmp_v2enable)
1571 				break;
1572 			if (igmp_input_v2_query(ifp, ip, igmp) != 0) {
1573 				m_freem(m);
1574 				return (IPPROTO_DONE);
1575 			}
1576 			break;
1577 
1578 		case IGMP_VERSION_3: {
1579 				struct igmpv3 *igmpv3;
1580 				uint16_t igmpv3len;
1581 				uint16_t nsrc;
1582 
1583 				IGMPSTAT_INC(igps_rcv_v3_queries);
1584 				igmpv3 = (struct igmpv3 *)igmp;
1585 				/*
1586 				 * Validate length based on source count.
1587 				 */
1588 				nsrc = ntohs(igmpv3->igmp_numsrc);
1589 				if (nsrc * sizeof(in_addr_t) >
1590 				    UINT16_MAX - iphlen - IGMP_V3_QUERY_MINLEN) {
1591 					IGMPSTAT_INC(igps_rcv_tooshort);
1592 					return (IPPROTO_DONE);
1593 				}
1594 				/*
1595 				 * m_pullup() may modify m, so pullup in
1596 				 * this scope.
1597 				 */
1598 				igmpv3len = iphlen + IGMP_V3_QUERY_MINLEN +
1599 				   sizeof(struct in_addr) * nsrc;
1600 				if ((!M_WRITABLE(m) ||
1601 				     m->m_len < igmpv3len) &&
1602 				    (m = m_pullup(m, igmpv3len)) == NULL) {
1603 					IGMPSTAT_INC(igps_rcv_tooshort);
1604 					return (IPPROTO_DONE);
1605 				}
1606 				igmpv3 = (struct igmpv3 *)(mtod(m, uint8_t *)
1607 				    + iphlen);
1608 				if (igmp_input_v3_query(ifp, ip, igmpv3) != 0) {
1609 					m_freem(m);
1610 					return (IPPROTO_DONE);
1611 				}
1612 			}
1613 			break;
1614 		}
1615 		break;
1616 
1617 	case IGMP_v1_HOST_MEMBERSHIP_REPORT:
1618 		if (!V_igmp_v1enable)
1619 			break;
1620 		if (igmp_input_v1_report(ifp, ip, igmp) != 0) {
1621 			m_freem(m);
1622 			return (IPPROTO_DONE);
1623 		}
1624 		break;
1625 
1626 	case IGMP_v2_HOST_MEMBERSHIP_REPORT:
1627 		if (!V_igmp_v2enable)
1628 			break;
1629 		if (!ip_checkrouteralert(m))
1630 			IGMPSTAT_INC(igps_rcv_nora);
1631 		if (igmp_input_v2_report(ifp, ip, igmp) != 0) {
1632 			m_freem(m);
1633 			return (IPPROTO_DONE);
1634 		}
1635 		break;
1636 
1637 	case IGMP_v3_HOST_MEMBERSHIP_REPORT:
1638 		/*
1639 		 * Hosts do not need to process IGMPv3 membership reports,
1640 		 * as report suppression is no longer required.
1641 		 */
1642 		if (!ip_checkrouteralert(m))
1643 			IGMPSTAT_INC(igps_rcv_nora);
1644 		break;
1645 
1646 	default:
1647 		break;
1648 	}
1649 
1650 	/*
1651 	 * Pass all valid IGMP packets up to any process(es) listening on a
1652 	 * raw IGMP socket.
1653 	 */
1654 	*mp = m;
1655 	return (rip_input(mp, offp, proto));
1656 }
1657 
1658 /*
1659  * Fast timeout handler (global).
1660  * VIMAGE: Timeout handlers are expected to service all vimages.
1661  */
1662 void
1663 igmp_fasttimo(void)
1664 {
1665 	VNET_ITERATOR_DECL(vnet_iter);
1666 
1667 	VNET_LIST_RLOCK_NOSLEEP();
1668 	VNET_FOREACH(vnet_iter) {
1669 		CURVNET_SET(vnet_iter);
1670 		igmp_fasttimo_vnet();
1671 		CURVNET_RESTORE();
1672 	}
1673 	VNET_LIST_RUNLOCK_NOSLEEP();
1674 }
1675 
1676 /*
1677  * Fast timeout handler (per-vnet).
1678  * Sends are shuffled off to a netisr to deal with Giant.
1679  *
1680  * VIMAGE: Assume caller has set up our curvnet.
1681  */
1682 static void
1683 igmp_fasttimo_vnet(void)
1684 {
1685 	struct mbufq		 scq;	/* State-change packets */
1686 	struct mbufq		 qrq;	/* Query response packets */
1687 	struct ifnet		*ifp;
1688 	struct igmp_ifsoftc	*igi;
1689 	struct ifmultiaddr	*ifma, *next;
1690 	struct in_multi		*inm;
1691 	struct in_multi_head inm_free_tmp;
1692 	int			 loop, uri_fasthz;
1693 
1694 	loop = 0;
1695 	uri_fasthz = 0;
1696 
1697 	/*
1698 	 * Quick check to see if any work needs to be done, in order to
1699 	 * minimize the overhead of fasttimo processing.
1700 	 * SMPng: XXX Unlocked reads.
1701 	 */
1702 	if (!V_current_state_timers_running &&
1703 	    !V_interface_timers_running &&
1704 	    !V_state_change_timers_running)
1705 		return;
1706 
1707 	SLIST_INIT(&inm_free_tmp);
1708 	IN_MULTI_LIST_LOCK();
1709 	IGMP_LOCK();
1710 
1711 	/*
1712 	 * IGMPv3 General Query response timer processing.
1713 	 */
1714 	if (V_interface_timers_running) {
1715 		CTR1(KTR_IGMPV3, "%s: interface timers running", __func__);
1716 
1717 		V_interface_timers_running = 0;
1718 		LIST_FOREACH(igi, &V_igi_head, igi_link) {
1719 			if (igi->igi_v3_timer == 0) {
1720 				/* Do nothing. */
1721 			} else if (--igi->igi_v3_timer == 0) {
1722 				igmp_v3_dispatch_general_query(igi);
1723 			} else {
1724 				V_interface_timers_running = 1;
1725 			}
1726 		}
1727 	}
1728 
1729 	if (!V_current_state_timers_running &&
1730 	    !V_state_change_timers_running)
1731 		goto out_locked;
1732 
1733 	V_current_state_timers_running = 0;
1734 	V_state_change_timers_running = 0;
1735 
1736 	CTR1(KTR_IGMPV3, "%s: state change timers running", __func__);
1737 
1738 	/*
1739 	 * IGMPv1/v2/v3 host report and state-change timer processing.
1740 	 * Note: Processing a v3 group timer may remove a node.
1741 	 */
1742 	LIST_FOREACH(igi, &V_igi_head, igi_link) {
1743 		ifp = igi->igi_ifp;
1744 
1745 		if (igi->igi_version == IGMP_VERSION_3) {
1746 			loop = (igi->igi_flags & IGIF_LOOPBACK) ? 1 : 0;
1747 			uri_fasthz = IGMP_RANDOM_DELAY(igi->igi_uri *
1748 			    PR_FASTHZ);
1749 			mbufq_init(&qrq, IGMP_MAX_G_GS_PACKETS);
1750 			mbufq_init(&scq, IGMP_MAX_STATE_CHANGE_PACKETS);
1751 		}
1752 
1753 		IF_ADDR_WLOCK(ifp);
1754 	restart:
1755 		CK_STAILQ_FOREACH_SAFE(ifma, &ifp->if_multiaddrs, ifma_link, next) {
1756 			if (ifma->ifma_addr->sa_family != AF_INET ||
1757 			    ifma->ifma_protospec == NULL)
1758 				continue;
1759 			inm = (struct in_multi *)ifma->ifma_protospec;
1760 			switch (igi->igi_version) {
1761 			case IGMP_VERSION_1:
1762 			case IGMP_VERSION_2:
1763 				igmp_v1v2_process_group_timer(inm,
1764 				    igi->igi_version);
1765 				break;
1766 			case IGMP_VERSION_3:
1767 				igmp_v3_process_group_timers(&inm_free_tmp, &qrq,
1768 				    &scq, inm, uri_fasthz);
1769 				break;
1770 			}
1771 			if (__predict_false(ifma_restart)) {
1772 				ifma_restart = false;
1773 				goto restart;
1774 			}
1775 		}
1776 		IF_ADDR_WUNLOCK(ifp);
1777 
1778 		if (igi->igi_version == IGMP_VERSION_3) {
1779 			igmp_dispatch_queue(&qrq, 0, loop);
1780 			igmp_dispatch_queue(&scq, 0, loop);
1781 
1782 			/*
1783 			 * Free the in_multi reference(s) for this
1784 			 * IGMP lifecycle.
1785 			 */
1786 			inm_release_list_deferred(&inm_free_tmp);
1787 		}
1788 	}
1789 
1790 out_locked:
1791 	IGMP_UNLOCK();
1792 	IN_MULTI_LIST_UNLOCK();
1793 }
1794 
1795 /*
1796  * Update host report group timer for IGMPv1/v2.
1797  * Will update the global pending timer flags.
1798  */
1799 static void
1800 igmp_v1v2_process_group_timer(struct in_multi *inm, const int version)
1801 {
1802 	int report_timer_expired;
1803 
1804 	IN_MULTI_LIST_LOCK_ASSERT();
1805 	IGMP_LOCK_ASSERT();
1806 
1807 	if (inm->inm_timer == 0) {
1808 		report_timer_expired = 0;
1809 	} else if (--inm->inm_timer == 0) {
1810 		report_timer_expired = 1;
1811 	} else {
1812 		V_current_state_timers_running = 1;
1813 		return;
1814 	}
1815 
1816 	switch (inm->inm_state) {
1817 	case IGMP_NOT_MEMBER:
1818 	case IGMP_SILENT_MEMBER:
1819 	case IGMP_IDLE_MEMBER:
1820 	case IGMP_LAZY_MEMBER:
1821 	case IGMP_SLEEPING_MEMBER:
1822 	case IGMP_AWAKENING_MEMBER:
1823 		break;
1824 	case IGMP_REPORTING_MEMBER:
1825 		if (report_timer_expired) {
1826 			inm->inm_state = IGMP_IDLE_MEMBER;
1827 			(void)igmp_v1v2_queue_report(inm,
1828 			    (version == IGMP_VERSION_2) ?
1829 			     IGMP_v2_HOST_MEMBERSHIP_REPORT :
1830 			     IGMP_v1_HOST_MEMBERSHIP_REPORT);
1831 		}
1832 		break;
1833 	case IGMP_G_QUERY_PENDING_MEMBER:
1834 	case IGMP_SG_QUERY_PENDING_MEMBER:
1835 	case IGMP_LEAVING_MEMBER:
1836 		break;
1837 	}
1838 }
1839 
1840 /*
1841  * Update a group's timers for IGMPv3.
1842  * Will update the global pending timer flags.
1843  * Note: Unlocked read from igi.
1844  */
1845 static void
1846 igmp_v3_process_group_timers(struct in_multi_head *inmh,
1847     struct mbufq *qrq, struct mbufq *scq,
1848     struct in_multi *inm, const int uri_fasthz)
1849 {
1850 	int query_response_timer_expired;
1851 	int state_change_retransmit_timer_expired;
1852 
1853 	IN_MULTI_LIST_LOCK_ASSERT();
1854 	IGMP_LOCK_ASSERT();
1855 
1856 	query_response_timer_expired = 0;
1857 	state_change_retransmit_timer_expired = 0;
1858 
1859 	/*
1860 	 * During a transition from v1/v2 compatibility mode back to v3,
1861 	 * a group record in REPORTING state may still have its group
1862 	 * timer active. This is a no-op in this function; it is easier
1863 	 * to deal with it here than to complicate the slow-timeout path.
1864 	 */
1865 	if (inm->inm_timer == 0) {
1866 		query_response_timer_expired = 0;
1867 	} else if (--inm->inm_timer == 0) {
1868 		query_response_timer_expired = 1;
1869 	} else {
1870 		V_current_state_timers_running = 1;
1871 	}
1872 
1873 	if (inm->inm_sctimer == 0) {
1874 		state_change_retransmit_timer_expired = 0;
1875 	} else if (--inm->inm_sctimer == 0) {
1876 		state_change_retransmit_timer_expired = 1;
1877 	} else {
1878 		V_state_change_timers_running = 1;
1879 	}
1880 
1881 	/* We are in fasttimo, so be quick about it. */
1882 	if (!state_change_retransmit_timer_expired &&
1883 	    !query_response_timer_expired)
1884 		return;
1885 
1886 	switch (inm->inm_state) {
1887 	case IGMP_NOT_MEMBER:
1888 	case IGMP_SILENT_MEMBER:
1889 	case IGMP_SLEEPING_MEMBER:
1890 	case IGMP_LAZY_MEMBER:
1891 	case IGMP_AWAKENING_MEMBER:
1892 	case IGMP_IDLE_MEMBER:
1893 		break;
1894 	case IGMP_G_QUERY_PENDING_MEMBER:
1895 	case IGMP_SG_QUERY_PENDING_MEMBER:
1896 		/*
1897 		 * Respond to a previously pending Group-Specific
1898 		 * or Group-and-Source-Specific query by enqueueing
1899 		 * the appropriate Current-State report for
1900 		 * immediate transmission.
1901 		 */
1902 		if (query_response_timer_expired) {
1903 			int retval __unused;
1904 
1905 			retval = igmp_v3_enqueue_group_record(qrq, inm, 0, 1,
1906 			    (inm->inm_state == IGMP_SG_QUERY_PENDING_MEMBER));
1907 			CTR2(KTR_IGMPV3, "%s: enqueue record = %d",
1908 			    __func__, retval);
1909 			inm->inm_state = IGMP_REPORTING_MEMBER;
1910 			/* XXX Clear recorded sources for next time. */
1911 			inm_clear_recorded(inm);
1912 		}
1913 		/* FALLTHROUGH */
1914 	case IGMP_REPORTING_MEMBER:
1915 	case IGMP_LEAVING_MEMBER:
1916 		if (state_change_retransmit_timer_expired) {
1917 			/*
1918 			 * State-change retransmission timer fired.
1919 			 * If there are any further pending retransmissions,
1920 			 * set the global pending state-change flag, and
1921 			 * reset the timer.
1922 			 */
1923 			if (--inm->inm_scrv > 0) {
1924 				inm->inm_sctimer = uri_fasthz;
1925 				V_state_change_timers_running = 1;
1926 			}
1927 			/*
1928 			 * Retransmit the previously computed state-change
1929 			 * report. If there are no further pending
1930 			 * retransmissions, the mbuf queue will be consumed.
1931 			 * Update T0 state to T1 as we have now sent
1932 			 * a state-change.
1933 			 */
1934 			(void)igmp_v3_merge_state_changes(inm, scq);
1935 
1936 			inm_commit(inm);
1937 			CTR3(KTR_IGMPV3, "%s: T1 -> T0 for 0x%08x/%s", __func__,
1938 			    ntohl(inm->inm_addr.s_addr),
1939 			    inm->inm_ifp->if_xname);
1940 
1941 			/*
1942 			 * If we are leaving the group for good, make sure
1943 			 * we release IGMP's reference to it.
1944 			 * This release must be deferred using a SLIST,
1945 			 * as we are called from a loop which traverses
1946 			 * the in_ifmultiaddr TAILQ.
1947 			 */
1948 			if (inm->inm_state == IGMP_LEAVING_MEMBER &&
1949 			    inm->inm_scrv == 0) {
1950 				inm->inm_state = IGMP_NOT_MEMBER;
1951 				inm_rele_locked(inmh, inm);
1952 			}
1953 		}
1954 		break;
1955 	}
1956 }
1957 
1958 /*
1959  * Suppress a group's pending response to a group or source/group query.
1960  *
1961  * Do NOT suppress state changes. This leads to IGMPv3 inconsistency.
1962  * Do NOT update ST1/ST0 as this operation merely suppresses
1963  * the currently pending group record.
1964  * Do NOT suppress the response to a general query. It is possible but
1965  * it would require adding another state or flag.
1966  */
1967 static void
1968 igmp_v3_suppress_group_record(struct in_multi *inm)
1969 {
1970 
1971 	IN_MULTI_LIST_LOCK_ASSERT();
1972 
1973 	KASSERT(inm->inm_igi->igi_version == IGMP_VERSION_3,
1974 		("%s: not IGMPv3 mode on link", __func__));
1975 
1976 	if (inm->inm_state != IGMP_G_QUERY_PENDING_MEMBER ||
1977 	    inm->inm_state != IGMP_SG_QUERY_PENDING_MEMBER)
1978 		return;
1979 
1980 	if (inm->inm_state == IGMP_SG_QUERY_PENDING_MEMBER)
1981 		inm_clear_recorded(inm);
1982 
1983 	inm->inm_timer = 0;
1984 	inm->inm_state = IGMP_REPORTING_MEMBER;
1985 }
1986 
1987 /*
1988  * Switch to a different IGMP version on the given interface,
1989  * as per Section 7.2.1.
1990  */
1991 static void
1992 igmp_set_version(struct igmp_ifsoftc *igi, const int version)
1993 {
1994 	int old_version_timer;
1995 
1996 	IGMP_LOCK_ASSERT();
1997 
1998 	CTR4(KTR_IGMPV3, "%s: switching to v%d on ifp %p(%s)", __func__,
1999 	    version, igi->igi_ifp, igi->igi_ifp->if_xname);
2000 
2001 	if (version == IGMP_VERSION_1 || version == IGMP_VERSION_2) {
2002 		/*
2003 		 * Compute the "Older Version Querier Present" timer as per
2004 		 * Section 8.12.
2005 		 */
2006 		old_version_timer = igi->igi_rv * igi->igi_qi + igi->igi_qri;
2007 		old_version_timer *= PR_SLOWHZ;
2008 
2009 		if (version == IGMP_VERSION_1) {
2010 			igi->igi_v1_timer = old_version_timer;
2011 			igi->igi_v2_timer = 0;
2012 		} else if (version == IGMP_VERSION_2) {
2013 			igi->igi_v1_timer = 0;
2014 			igi->igi_v2_timer = old_version_timer;
2015 		}
2016 	}
2017 
2018 	if (igi->igi_v1_timer == 0 && igi->igi_v2_timer > 0) {
2019 		if (igi->igi_version != IGMP_VERSION_2) {
2020 			igi->igi_version = IGMP_VERSION_2;
2021 			igmp_v3_cancel_link_timers(igi);
2022 		}
2023 	} else if (igi->igi_v1_timer > 0) {
2024 		if (igi->igi_version != IGMP_VERSION_1) {
2025 			igi->igi_version = IGMP_VERSION_1;
2026 			igmp_v3_cancel_link_timers(igi);
2027 		}
2028 	}
2029 }
2030 
2031 /*
2032  * Cancel pending IGMPv3 timers for the given link and all groups
2033  * joined on it; state-change, general-query, and group-query timers.
2034  *
2035  * Only ever called on a transition from v3 to Compatibility mode. Kill
2036  * the timers stone dead (this may be expensive for large N groups), they
2037  * will be restarted if Compatibility Mode deems that they must be due to
2038  * query processing.
2039  */
2040 static void
2041 igmp_v3_cancel_link_timers(struct igmp_ifsoftc *igi)
2042 {
2043 	struct ifmultiaddr	*ifma, *ifmatmp;
2044 	struct ifnet		*ifp;
2045 	struct in_multi		*inm;
2046 	struct in_multi_head inm_free_tmp;
2047 
2048 	CTR3(KTR_IGMPV3, "%s: cancel v3 timers on ifp %p(%s)", __func__,
2049 	    igi->igi_ifp, igi->igi_ifp->if_xname);
2050 
2051 	IN_MULTI_LIST_LOCK_ASSERT();
2052 	IGMP_LOCK_ASSERT();
2053 	NET_EPOCH_ASSERT();
2054 
2055 	SLIST_INIT(&inm_free_tmp);
2056 
2057 	/*
2058 	 * Stop the v3 General Query Response on this link stone dead.
2059 	 * If fasttimo is woken up due to V_interface_timers_running,
2060 	 * the flag will be cleared if there are no pending link timers.
2061 	 */
2062 	igi->igi_v3_timer = 0;
2063 
2064 	/*
2065 	 * Now clear the current-state and state-change report timers
2066 	 * for all memberships scoped to this link.
2067 	 */
2068 	ifp = igi->igi_ifp;
2069 	IF_ADDR_WLOCK(ifp);
2070 	CK_STAILQ_FOREACH_SAFE(ifma, &ifp->if_multiaddrs, ifma_link, ifmatmp) {
2071 		if (ifma->ifma_addr->sa_family != AF_INET ||
2072 		    ifma->ifma_protospec == NULL)
2073 			continue;
2074 		inm = (struct in_multi *)ifma->ifma_protospec;
2075 		switch (inm->inm_state) {
2076 		case IGMP_NOT_MEMBER:
2077 		case IGMP_SILENT_MEMBER:
2078 		case IGMP_IDLE_MEMBER:
2079 		case IGMP_LAZY_MEMBER:
2080 		case IGMP_SLEEPING_MEMBER:
2081 		case IGMP_AWAKENING_MEMBER:
2082 			/*
2083 			 * These states are either not relevant in v3 mode,
2084 			 * or are unreported. Do nothing.
2085 			 */
2086 			break;
2087 		case IGMP_LEAVING_MEMBER:
2088 			/*
2089 			 * If we are leaving the group and switching to
2090 			 * compatibility mode, we need to release the final
2091 			 * reference held for issuing the INCLUDE {}, and
2092 			 * transition to REPORTING to ensure the host leave
2093 			 * message is sent upstream to the old querier --
2094 			 * transition to NOT would lose the leave and race.
2095 			 */
2096 			inm_rele_locked(&inm_free_tmp, inm);
2097 			/* FALLTHROUGH */
2098 		case IGMP_G_QUERY_PENDING_MEMBER:
2099 		case IGMP_SG_QUERY_PENDING_MEMBER:
2100 			inm_clear_recorded(inm);
2101 			/* FALLTHROUGH */
2102 		case IGMP_REPORTING_MEMBER:
2103 			inm->inm_state = IGMP_REPORTING_MEMBER;
2104 			break;
2105 		}
2106 		/*
2107 		 * Always clear state-change and group report timers.
2108 		 * Free any pending IGMPv3 state-change records.
2109 		 */
2110 		inm->inm_sctimer = 0;
2111 		inm->inm_timer = 0;
2112 		mbufq_drain(&inm->inm_scq);
2113 	}
2114 	IF_ADDR_WUNLOCK(ifp);
2115 
2116 	inm_release_list_deferred(&inm_free_tmp);
2117 }
2118 
2119 /*
2120  * Update the Older Version Querier Present timers for a link.
2121  * See Section 7.2.1 of RFC 3376.
2122  */
2123 static void
2124 igmp_v1v2_process_querier_timers(struct igmp_ifsoftc *igi)
2125 {
2126 
2127 	IGMP_LOCK_ASSERT();
2128 
2129 	if (igi->igi_v1_timer == 0 && igi->igi_v2_timer == 0) {
2130 		/*
2131 		 * IGMPv1 and IGMPv2 Querier Present timers expired.
2132 		 *
2133 		 * Revert to IGMPv3.
2134 		 */
2135 		if (igi->igi_version != IGMP_VERSION_3) {
2136 			CTR5(KTR_IGMPV3,
2137 			    "%s: transition from v%d -> v%d on %p(%s)",
2138 			    __func__, igi->igi_version, IGMP_VERSION_3,
2139 			    igi->igi_ifp, igi->igi_ifp->if_xname);
2140 			igi->igi_version = IGMP_VERSION_3;
2141 		}
2142 	} else if (igi->igi_v1_timer == 0 && igi->igi_v2_timer > 0) {
2143 		/*
2144 		 * IGMPv1 Querier Present timer expired,
2145 		 * IGMPv2 Querier Present timer running.
2146 		 * If IGMPv2 was disabled since last timeout,
2147 		 * revert to IGMPv3.
2148 		 * If IGMPv2 is enabled, revert to IGMPv2.
2149 		 */
2150 		if (!V_igmp_v2enable) {
2151 			CTR5(KTR_IGMPV3,
2152 			    "%s: transition from v%d -> v%d on %p(%s)",
2153 			    __func__, igi->igi_version, IGMP_VERSION_3,
2154 			    igi->igi_ifp, igi->igi_ifp->if_xname);
2155 			igi->igi_v2_timer = 0;
2156 			igi->igi_version = IGMP_VERSION_3;
2157 		} else {
2158 			--igi->igi_v2_timer;
2159 			if (igi->igi_version != IGMP_VERSION_2) {
2160 				CTR5(KTR_IGMPV3,
2161 				    "%s: transition from v%d -> v%d on %p(%s)",
2162 				    __func__, igi->igi_version, IGMP_VERSION_2,
2163 				    igi->igi_ifp, igi->igi_ifp->if_xname);
2164 				igi->igi_version = IGMP_VERSION_2;
2165 				igmp_v3_cancel_link_timers(igi);
2166 			}
2167 		}
2168 	} else if (igi->igi_v1_timer > 0) {
2169 		/*
2170 		 * IGMPv1 Querier Present timer running.
2171 		 * Stop IGMPv2 timer if running.
2172 		 *
2173 		 * If IGMPv1 was disabled since last timeout,
2174 		 * revert to IGMPv3.
2175 		 * If IGMPv1 is enabled, reset IGMPv2 timer if running.
2176 		 */
2177 		if (!V_igmp_v1enable) {
2178 			CTR5(KTR_IGMPV3,
2179 			    "%s: transition from v%d -> v%d on %p(%s)",
2180 			    __func__, igi->igi_version, IGMP_VERSION_3,
2181 			    igi->igi_ifp, igi->igi_ifp->if_xname);
2182 			igi->igi_v1_timer = 0;
2183 			igi->igi_version = IGMP_VERSION_3;
2184 		} else {
2185 			--igi->igi_v1_timer;
2186 		}
2187 		if (igi->igi_v2_timer > 0) {
2188 			CTR3(KTR_IGMPV3,
2189 			    "%s: cancel v2 timer on %p(%s)",
2190 			    __func__, igi->igi_ifp, igi->igi_ifp->if_xname);
2191 			igi->igi_v2_timer = 0;
2192 		}
2193 	}
2194 }
2195 
2196 /*
2197  * Global slowtimo handler.
2198  * VIMAGE: Timeout handlers are expected to service all vimages.
2199  */
2200 void
2201 igmp_slowtimo(void)
2202 {
2203 	VNET_ITERATOR_DECL(vnet_iter);
2204 
2205 	VNET_LIST_RLOCK_NOSLEEP();
2206 	VNET_FOREACH(vnet_iter) {
2207 		CURVNET_SET(vnet_iter);
2208 		igmp_slowtimo_vnet();
2209 		CURVNET_RESTORE();
2210 	}
2211 	VNET_LIST_RUNLOCK_NOSLEEP();
2212 }
2213 
2214 /*
2215  * Per-vnet slowtimo handler.
2216  */
2217 static void
2218 igmp_slowtimo_vnet(void)
2219 {
2220 	struct igmp_ifsoftc *igi;
2221 
2222 	IGMP_LOCK();
2223 
2224 	LIST_FOREACH(igi, &V_igi_head, igi_link) {
2225 		igmp_v1v2_process_querier_timers(igi);
2226 	}
2227 
2228 	IGMP_UNLOCK();
2229 }
2230 
2231 /*
2232  * Dispatch an IGMPv1/v2 host report or leave message.
2233  * These are always small enough to fit inside a single mbuf.
2234  */
2235 static int
2236 igmp_v1v2_queue_report(struct in_multi *inm, const int type)
2237 {
2238 	struct epoch_tracker 	et;
2239 	struct ifnet		*ifp;
2240 	struct igmp		*igmp;
2241 	struct ip		*ip;
2242 	struct mbuf		*m;
2243 
2244 	IN_MULTI_LIST_LOCK_ASSERT();
2245 	IGMP_LOCK_ASSERT();
2246 
2247 	ifp = inm->inm_ifp;
2248 
2249 	m = m_gethdr(M_NOWAIT, MT_DATA);
2250 	if (m == NULL)
2251 		return (ENOMEM);
2252 	M_ALIGN(m, sizeof(struct ip) + sizeof(struct igmp));
2253 
2254 	m->m_pkthdr.len = sizeof(struct ip) + sizeof(struct igmp);
2255 
2256 	m->m_data += sizeof(struct ip);
2257 	m->m_len = sizeof(struct igmp);
2258 
2259 	igmp = mtod(m, struct igmp *);
2260 	igmp->igmp_type = type;
2261 	igmp->igmp_code = 0;
2262 	igmp->igmp_group = inm->inm_addr;
2263 	igmp->igmp_cksum = 0;
2264 	igmp->igmp_cksum = in_cksum(m, sizeof(struct igmp));
2265 
2266 	m->m_data -= sizeof(struct ip);
2267 	m->m_len += sizeof(struct ip);
2268 
2269 	ip = mtod(m, struct ip *);
2270 	ip->ip_tos = 0;
2271 	ip->ip_len = htons(sizeof(struct ip) + sizeof(struct igmp));
2272 	ip->ip_off = 0;
2273 	ip->ip_p = IPPROTO_IGMP;
2274 	ip->ip_src.s_addr = INADDR_ANY;
2275 
2276 	if (type == IGMP_HOST_LEAVE_MESSAGE)
2277 		ip->ip_dst.s_addr = htonl(INADDR_ALLRTRS_GROUP);
2278 	else
2279 		ip->ip_dst = inm->inm_addr;
2280 
2281 	igmp_save_context(m, ifp);
2282 
2283 	m->m_flags |= M_IGMPV2;
2284 	if (inm->inm_igi->igi_flags & IGIF_LOOPBACK)
2285 		m->m_flags |= M_IGMP_LOOP;
2286 
2287 	CTR2(KTR_IGMPV3, "%s: netisr_dispatch(NETISR_IGMP, %p)", __func__, m);
2288 	NET_EPOCH_ENTER(et);
2289 	netisr_dispatch(NETISR_IGMP, m);
2290 	NET_EPOCH_EXIT(et);
2291 
2292 	return (0);
2293 }
2294 
2295 /*
2296  * Process a state change from the upper layer for the given IPv4 group.
2297  *
2298  * Each socket holds a reference on the in_multi in its own ip_moptions.
2299  * The socket layer will have made the necessary updates to.the group
2300  * state, it is now up to IGMP to issue a state change report if there
2301  * has been any change between T0 (when the last state-change was issued)
2302  * and T1 (now).
2303  *
2304  * We use the IGMPv3 state machine at group level. The IGMP module
2305  * however makes the decision as to which IGMP protocol version to speak.
2306  * A state change *from* INCLUDE {} always means an initial join.
2307  * A state change *to* INCLUDE {} always means a final leave.
2308  *
2309  * FUTURE: If IGIF_V3LITE is enabled for this interface, then we can
2310  * save ourselves a bunch of work; any exclusive mode groups need not
2311  * compute source filter lists.
2312  *
2313  * VIMAGE: curvnet should have been set by caller, as this routine
2314  * is called from the socket option handlers.
2315  */
2316 int
2317 igmp_change_state(struct in_multi *inm)
2318 {
2319 	struct igmp_ifsoftc *igi;
2320 	struct ifnet *ifp;
2321 	int error;
2322 
2323 	error = 0;
2324 	IN_MULTI_LOCK_ASSERT();
2325 	/*
2326 	 * Try to detect if the upper layer just asked us to change state
2327 	 * for an interface which has now gone away.
2328 	 */
2329 	KASSERT(inm->inm_ifma != NULL, ("%s: no ifma", __func__));
2330 	ifp = inm->inm_ifma->ifma_ifp;
2331 	/*
2332 	 * Sanity check that netinet's notion of ifp is the
2333 	 * same as net's.
2334 	 */
2335 	KASSERT(inm->inm_ifp == ifp, ("%s: bad ifp", __func__));
2336 
2337 	IGMP_LOCK();
2338 
2339 	igi = ((struct in_ifinfo *)ifp->if_afdata[AF_INET])->ii_igmp;
2340 	KASSERT(igi != NULL, ("%s: no igmp_ifsoftc for ifp %p", __func__, ifp));
2341 
2342 	/*
2343 	 * If we detect a state transition to or from MCAST_UNDEFINED
2344 	 * for this group, then we are starting or finishing an IGMP
2345 	 * life cycle for this group.
2346 	 */
2347 	if (inm->inm_st[1].iss_fmode != inm->inm_st[0].iss_fmode) {
2348 		CTR3(KTR_IGMPV3, "%s: inm transition %d -> %d", __func__,
2349 		    inm->inm_st[0].iss_fmode, inm->inm_st[1].iss_fmode);
2350 		if (inm->inm_st[0].iss_fmode == MCAST_UNDEFINED) {
2351 			CTR1(KTR_IGMPV3, "%s: initial join", __func__);
2352 			error = igmp_initial_join(inm, igi);
2353 			goto out_locked;
2354 		} else if (inm->inm_st[1].iss_fmode == MCAST_UNDEFINED) {
2355 			CTR1(KTR_IGMPV3, "%s: final leave", __func__);
2356 			igmp_final_leave(inm, igi);
2357 			goto out_locked;
2358 		}
2359 	} else {
2360 		CTR1(KTR_IGMPV3, "%s: filter set change", __func__);
2361 	}
2362 
2363 	error = igmp_handle_state_change(inm, igi);
2364 
2365 out_locked:
2366 	IGMP_UNLOCK();
2367 	return (error);
2368 }
2369 
2370 /*
2371  * Perform the initial join for an IGMP group.
2372  *
2373  * When joining a group:
2374  *  If the group should have its IGMP traffic suppressed, do nothing.
2375  *  IGMPv1 starts sending IGMPv1 host membership reports.
2376  *  IGMPv2 starts sending IGMPv2 host membership reports.
2377  *  IGMPv3 will schedule an IGMPv3 state-change report containing the
2378  *  initial state of the membership.
2379  */
2380 static int
2381 igmp_initial_join(struct in_multi *inm, struct igmp_ifsoftc *igi)
2382 {
2383 	struct ifnet		*ifp;
2384 	struct mbufq		*mq;
2385 	int			 error, retval, syncstates;
2386 
2387 	CTR4(KTR_IGMPV3, "%s: initial join 0x%08x on ifp %p(%s)", __func__,
2388 	    ntohl(inm->inm_addr.s_addr), inm->inm_ifp, inm->inm_ifp->if_xname);
2389 
2390 	error = 0;
2391 	syncstates = 1;
2392 
2393 	ifp = inm->inm_ifp;
2394 
2395 	IN_MULTI_LOCK_ASSERT();
2396 	IGMP_LOCK_ASSERT();
2397 
2398 	KASSERT(igi && igi->igi_ifp == ifp, ("%s: inconsistent ifp", __func__));
2399 
2400 	/*
2401 	 * Groups joined on loopback or marked as 'not reported',
2402 	 * e.g. 224.0.0.1, enter the IGMP_SILENT_MEMBER state and
2403 	 * are never reported in any IGMP protocol exchanges.
2404 	 * All other groups enter the appropriate IGMP state machine
2405 	 * for the version in use on this link.
2406 	 * A link marked as IGIF_SILENT causes IGMP to be completely
2407 	 * disabled for the link.
2408 	 */
2409 	if ((ifp->if_flags & IFF_LOOPBACK) ||
2410 	    (igi->igi_flags & IGIF_SILENT) ||
2411 	    !igmp_isgroupreported(inm->inm_addr)) {
2412 		CTR1(KTR_IGMPV3,
2413 "%s: not kicking state machine for silent group", __func__);
2414 		inm->inm_state = IGMP_SILENT_MEMBER;
2415 		inm->inm_timer = 0;
2416 	} else {
2417 		/*
2418 		 * Deal with overlapping in_multi lifecycle.
2419 		 * If this group was LEAVING, then make sure
2420 		 * we drop the reference we picked up to keep the
2421 		 * group around for the final INCLUDE {} enqueue.
2422 		 */
2423 		if (igi->igi_version == IGMP_VERSION_3 &&
2424 		    inm->inm_state == IGMP_LEAVING_MEMBER) {
2425 			MPASS(inm->inm_refcount > 1);
2426 			inm_rele_locked(NULL, inm);
2427 		}
2428 		inm->inm_state = IGMP_REPORTING_MEMBER;
2429 
2430 		switch (igi->igi_version) {
2431 		case IGMP_VERSION_1:
2432 		case IGMP_VERSION_2:
2433 			inm->inm_state = IGMP_IDLE_MEMBER;
2434 			error = igmp_v1v2_queue_report(inm,
2435 			    (igi->igi_version == IGMP_VERSION_2) ?
2436 			     IGMP_v2_HOST_MEMBERSHIP_REPORT :
2437 			     IGMP_v1_HOST_MEMBERSHIP_REPORT);
2438 			if (error == 0) {
2439 				inm->inm_timer = IGMP_RANDOM_DELAY(
2440 				    IGMP_V1V2_MAX_RI * PR_FASTHZ);
2441 				V_current_state_timers_running = 1;
2442 			}
2443 			break;
2444 
2445 		case IGMP_VERSION_3:
2446 			/*
2447 			 * Defer update of T0 to T1, until the first copy
2448 			 * of the state change has been transmitted.
2449 			 */
2450 			syncstates = 0;
2451 
2452 			/*
2453 			 * Immediately enqueue a State-Change Report for
2454 			 * this interface, freeing any previous reports.
2455 			 * Don't kick the timers if there is nothing to do,
2456 			 * or if an error occurred.
2457 			 */
2458 			mq = &inm->inm_scq;
2459 			mbufq_drain(mq);
2460 			retval = igmp_v3_enqueue_group_record(mq, inm, 1,
2461 			    0, 0);
2462 			CTR2(KTR_IGMPV3, "%s: enqueue record = %d",
2463 			    __func__, retval);
2464 			if (retval <= 0) {
2465 				error = retval * -1;
2466 				break;
2467 			}
2468 
2469 			/*
2470 			 * Schedule transmission of pending state-change
2471 			 * report up to RV times for this link. The timer
2472 			 * will fire at the next igmp_fasttimo (~200ms),
2473 			 * giving us an opportunity to merge the reports.
2474 			 */
2475 			if (igi->igi_flags & IGIF_LOOPBACK) {
2476 				inm->inm_scrv = 1;
2477 			} else {
2478 				KASSERT(igi->igi_rv > 1,
2479 				   ("%s: invalid robustness %d", __func__,
2480 				    igi->igi_rv));
2481 				inm->inm_scrv = igi->igi_rv;
2482 			}
2483 			inm->inm_sctimer = 1;
2484 			V_state_change_timers_running = 1;
2485 
2486 			error = 0;
2487 			break;
2488 		}
2489 	}
2490 
2491 	/*
2492 	 * Only update the T0 state if state change is atomic,
2493 	 * i.e. we don't need to wait for a timer to fire before we
2494 	 * can consider the state change to have been communicated.
2495 	 */
2496 	if (syncstates) {
2497 		inm_commit(inm);
2498 		CTR3(KTR_IGMPV3, "%s: T1 -> T0 for 0x%08x/%s", __func__,
2499 		    ntohl(inm->inm_addr.s_addr), inm->inm_ifp->if_xname);
2500 	}
2501 
2502 	return (error);
2503 }
2504 
2505 /*
2506  * Issue an intermediate state change during the IGMP life-cycle.
2507  */
2508 static int
2509 igmp_handle_state_change(struct in_multi *inm, struct igmp_ifsoftc *igi)
2510 {
2511 	struct ifnet		*ifp;
2512 	int			 retval;
2513 
2514 	CTR4(KTR_IGMPV3, "%s: state change for 0x%08x on ifp %p(%s)", __func__,
2515 	    ntohl(inm->inm_addr.s_addr), inm->inm_ifp, inm->inm_ifp->if_xname);
2516 
2517 	ifp = inm->inm_ifp;
2518 
2519 	IN_MULTI_LIST_LOCK_ASSERT();
2520 	IGMP_LOCK_ASSERT();
2521 
2522 	KASSERT(igi && igi->igi_ifp == ifp, ("%s: inconsistent ifp", __func__));
2523 
2524 	if ((ifp->if_flags & IFF_LOOPBACK) ||
2525 	    (igi->igi_flags & IGIF_SILENT) ||
2526 	    !igmp_isgroupreported(inm->inm_addr) ||
2527 	    (igi->igi_version != IGMP_VERSION_3)) {
2528 		if (!igmp_isgroupreported(inm->inm_addr)) {
2529 			CTR1(KTR_IGMPV3,
2530 "%s: not kicking state machine for silent group", __func__);
2531 		}
2532 		CTR1(KTR_IGMPV3, "%s: nothing to do", __func__);
2533 		inm_commit(inm);
2534 		CTR3(KTR_IGMPV3, "%s: T1 -> T0 for 0x%08x/%s", __func__,
2535 		    ntohl(inm->inm_addr.s_addr), inm->inm_ifp->if_xname);
2536 		return (0);
2537 	}
2538 
2539 	mbufq_drain(&inm->inm_scq);
2540 
2541 	retval = igmp_v3_enqueue_group_record(&inm->inm_scq, inm, 1, 0, 0);
2542 	CTR2(KTR_IGMPV3, "%s: enqueue record = %d", __func__, retval);
2543 	if (retval <= 0)
2544 		return (-retval);
2545 
2546 	/*
2547 	 * If record(s) were enqueued, start the state-change
2548 	 * report timer for this group.
2549 	 */
2550 	inm->inm_scrv = ((igi->igi_flags & IGIF_LOOPBACK) ? 1 : igi->igi_rv);
2551 	inm->inm_sctimer = 1;
2552 	V_state_change_timers_running = 1;
2553 
2554 	return (0);
2555 }
2556 
2557 /*
2558  * Perform the final leave for an IGMP group.
2559  *
2560  * When leaving a group:
2561  *  IGMPv1 does nothing.
2562  *  IGMPv2 sends a host leave message, if and only if we are the reporter.
2563  *  IGMPv3 enqueues a state-change report containing a transition
2564  *  to INCLUDE {} for immediate transmission.
2565  */
2566 static void
2567 igmp_final_leave(struct in_multi *inm, struct igmp_ifsoftc *igi)
2568 {
2569 	int syncstates;
2570 
2571 	syncstates = 1;
2572 
2573 	CTR4(KTR_IGMPV3, "%s: final leave 0x%08x on ifp %p(%s)",
2574 	    __func__, ntohl(inm->inm_addr.s_addr), inm->inm_ifp,
2575 	    inm->inm_ifp->if_xname);
2576 
2577 	IN_MULTI_LIST_LOCK_ASSERT();
2578 	IGMP_LOCK_ASSERT();
2579 
2580 	switch (inm->inm_state) {
2581 	case IGMP_NOT_MEMBER:
2582 	case IGMP_SILENT_MEMBER:
2583 	case IGMP_LEAVING_MEMBER:
2584 		/* Already leaving or left; do nothing. */
2585 		CTR1(KTR_IGMPV3,
2586 "%s: not kicking state machine for silent group", __func__);
2587 		break;
2588 	case IGMP_REPORTING_MEMBER:
2589 	case IGMP_IDLE_MEMBER:
2590 	case IGMP_G_QUERY_PENDING_MEMBER:
2591 	case IGMP_SG_QUERY_PENDING_MEMBER:
2592 		if (igi->igi_version == IGMP_VERSION_2) {
2593 #ifdef INVARIANTS
2594 			if (inm->inm_state == IGMP_G_QUERY_PENDING_MEMBER ||
2595 			    inm->inm_state == IGMP_SG_QUERY_PENDING_MEMBER)
2596 			panic("%s: IGMPv3 state reached, not IGMPv3 mode",
2597 			     __func__);
2598 #endif
2599 			igmp_v1v2_queue_report(inm, IGMP_HOST_LEAVE_MESSAGE);
2600 			inm->inm_state = IGMP_NOT_MEMBER;
2601 		} else if (igi->igi_version == IGMP_VERSION_3) {
2602 			/*
2603 			 * Stop group timer and all pending reports.
2604 			 * Immediately enqueue a state-change report
2605 			 * TO_IN {} to be sent on the next fast timeout,
2606 			 * giving us an opportunity to merge reports.
2607 			 */
2608 			mbufq_drain(&inm->inm_scq);
2609 			inm->inm_timer = 0;
2610 			if (igi->igi_flags & IGIF_LOOPBACK) {
2611 				inm->inm_scrv = 1;
2612 			} else {
2613 				inm->inm_scrv = igi->igi_rv;
2614 			}
2615 			CTR4(KTR_IGMPV3, "%s: Leaving 0x%08x/%s with %d "
2616 			    "pending retransmissions.", __func__,
2617 			    ntohl(inm->inm_addr.s_addr),
2618 			    inm->inm_ifp->if_xname, inm->inm_scrv);
2619 			if (inm->inm_scrv == 0) {
2620 				inm->inm_state = IGMP_NOT_MEMBER;
2621 				inm->inm_sctimer = 0;
2622 			} else {
2623 				int retval __unused;
2624 
2625 				inm_acquire_locked(inm);
2626 
2627 				retval = igmp_v3_enqueue_group_record(
2628 				    &inm->inm_scq, inm, 1, 0, 0);
2629 				KASSERT(retval != 0,
2630 				    ("%s: enqueue record = %d", __func__,
2631 				     retval));
2632 
2633 				inm->inm_state = IGMP_LEAVING_MEMBER;
2634 				inm->inm_sctimer = 1;
2635 				V_state_change_timers_running = 1;
2636 				syncstates = 0;
2637 			}
2638 			break;
2639 		}
2640 		break;
2641 	case IGMP_LAZY_MEMBER:
2642 	case IGMP_SLEEPING_MEMBER:
2643 	case IGMP_AWAKENING_MEMBER:
2644 		/* Our reports are suppressed; do nothing. */
2645 		break;
2646 	}
2647 
2648 	if (syncstates) {
2649 		inm_commit(inm);
2650 		CTR3(KTR_IGMPV3, "%s: T1 -> T0 for 0x%08x/%s", __func__,
2651 		    ntohl(inm->inm_addr.s_addr), inm->inm_ifp->if_xname);
2652 		inm->inm_st[1].iss_fmode = MCAST_UNDEFINED;
2653 		CTR3(KTR_IGMPV3, "%s: T1 now MCAST_UNDEFINED for 0x%08x/%s",
2654 		    __func__, ntohl(inm->inm_addr.s_addr),
2655 		    inm->inm_ifp->if_xname);
2656 	}
2657 }
2658 
2659 /*
2660  * Enqueue an IGMPv3 group record to the given output queue.
2661  *
2662  * XXX This function could do with having the allocation code
2663  * split out, and the multiple-tree-walks coalesced into a single
2664  * routine as has been done in igmp_v3_enqueue_filter_change().
2665  *
2666  * If is_state_change is zero, a current-state record is appended.
2667  * If is_state_change is non-zero, a state-change report is appended.
2668  *
2669  * If is_group_query is non-zero, an mbuf packet chain is allocated.
2670  * If is_group_query is zero, and if there is a packet with free space
2671  * at the tail of the queue, it will be appended to providing there
2672  * is enough free space.
2673  * Otherwise a new mbuf packet chain is allocated.
2674  *
2675  * If is_source_query is non-zero, each source is checked to see if
2676  * it was recorded for a Group-Source query, and will be omitted if
2677  * it is not both in-mode and recorded.
2678  *
2679  * The function will attempt to allocate leading space in the packet
2680  * for the IP/IGMP header to be prepended without fragmenting the chain.
2681  *
2682  * If successful the size of all data appended to the queue is returned,
2683  * otherwise an error code less than zero is returned, or zero if
2684  * no record(s) were appended.
2685  */
2686 static int
2687 igmp_v3_enqueue_group_record(struct mbufq *mq, struct in_multi *inm,
2688     const int is_state_change, const int is_group_query,
2689     const int is_source_query)
2690 {
2691 	struct igmp_grouprec	 ig;
2692 	struct igmp_grouprec	*pig;
2693 	struct ifnet		*ifp;
2694 	struct ip_msource	*ims, *nims;
2695 	struct mbuf		*m0, *m, *md;
2696 	int			 is_filter_list_change;
2697 	int			 minrec0len, m0srcs, msrcs, nbytes, off;
2698 	int			 record_has_sources;
2699 	int			 now;
2700 	int			 type;
2701 	in_addr_t		 naddr;
2702 	uint8_t			 mode;
2703 
2704 	IN_MULTI_LIST_LOCK_ASSERT();
2705 
2706 	ifp = inm->inm_ifp;
2707 	is_filter_list_change = 0;
2708 	m = NULL;
2709 	m0 = NULL;
2710 	m0srcs = 0;
2711 	msrcs = 0;
2712 	nbytes = 0;
2713 	nims = NULL;
2714 	record_has_sources = 1;
2715 	pig = NULL;
2716 	type = IGMP_DO_NOTHING;
2717 	mode = inm->inm_st[1].iss_fmode;
2718 
2719 	/*
2720 	 * If we did not transition out of ASM mode during t0->t1,
2721 	 * and there are no source nodes to process, we can skip
2722 	 * the generation of source records.
2723 	 */
2724 	if (inm->inm_st[0].iss_asm > 0 && inm->inm_st[1].iss_asm > 0 &&
2725 	    inm->inm_nsrc == 0)
2726 		record_has_sources = 0;
2727 
2728 	if (is_state_change) {
2729 		/*
2730 		 * Queue a state change record.
2731 		 * If the mode did not change, and there are non-ASM
2732 		 * listeners or source filters present,
2733 		 * we potentially need to issue two records for the group.
2734 		 * If we are transitioning to MCAST_UNDEFINED, we need
2735 		 * not send any sources.
2736 		 * If there are ASM listeners, and there was no filter
2737 		 * mode transition of any kind, do nothing.
2738 		 */
2739 		if (mode != inm->inm_st[0].iss_fmode) {
2740 			if (mode == MCAST_EXCLUDE) {
2741 				CTR1(KTR_IGMPV3, "%s: change to EXCLUDE",
2742 				    __func__);
2743 				type = IGMP_CHANGE_TO_EXCLUDE_MODE;
2744 			} else {
2745 				CTR1(KTR_IGMPV3, "%s: change to INCLUDE",
2746 				    __func__);
2747 				type = IGMP_CHANGE_TO_INCLUDE_MODE;
2748 				if (mode == MCAST_UNDEFINED)
2749 					record_has_sources = 0;
2750 			}
2751 		} else {
2752 			if (record_has_sources) {
2753 				is_filter_list_change = 1;
2754 			} else {
2755 				type = IGMP_DO_NOTHING;
2756 			}
2757 		}
2758 	} else {
2759 		/*
2760 		 * Queue a current state record.
2761 		 */
2762 		if (mode == MCAST_EXCLUDE) {
2763 			type = IGMP_MODE_IS_EXCLUDE;
2764 		} else if (mode == MCAST_INCLUDE) {
2765 			type = IGMP_MODE_IS_INCLUDE;
2766 			KASSERT(inm->inm_st[1].iss_asm == 0,
2767 			    ("%s: inm %p is INCLUDE but ASM count is %d",
2768 			     __func__, inm, inm->inm_st[1].iss_asm));
2769 		}
2770 	}
2771 
2772 	/*
2773 	 * Generate the filter list changes using a separate function.
2774 	 */
2775 	if (is_filter_list_change)
2776 		return (igmp_v3_enqueue_filter_change(mq, inm));
2777 
2778 	if (type == IGMP_DO_NOTHING) {
2779 		CTR3(KTR_IGMPV3, "%s: nothing to do for 0x%08x/%s", __func__,
2780 		    ntohl(inm->inm_addr.s_addr), inm->inm_ifp->if_xname);
2781 		return (0);
2782 	}
2783 
2784 	/*
2785 	 * If any sources are present, we must be able to fit at least
2786 	 * one in the trailing space of the tail packet's mbuf,
2787 	 * ideally more.
2788 	 */
2789 	minrec0len = sizeof(struct igmp_grouprec);
2790 	if (record_has_sources)
2791 		minrec0len += sizeof(in_addr_t);
2792 
2793 	CTR4(KTR_IGMPV3, "%s: queueing %s for 0x%08x/%s", __func__,
2794 	    igmp_rec_type_to_str(type), ntohl(inm->inm_addr.s_addr),
2795 	    inm->inm_ifp->if_xname);
2796 
2797 	/*
2798 	 * Check if we have a packet in the tail of the queue for this
2799 	 * group into which the first group record for this group will fit.
2800 	 * Otherwise allocate a new packet.
2801 	 * Always allocate leading space for IP+RA_OPT+IGMP+REPORT.
2802 	 * Note: Group records for G/GSR query responses MUST be sent
2803 	 * in their own packet.
2804 	 */
2805 	m0 = mbufq_last(mq);
2806 	if (!is_group_query &&
2807 	    m0 != NULL &&
2808 	    (m0->m_pkthdr.PH_vt.vt_nrecs + 1 <= IGMP_V3_REPORT_MAXRECS) &&
2809 	    (m0->m_pkthdr.len + minrec0len) <
2810 	     (ifp->if_mtu - IGMP_LEADINGSPACE)) {
2811 		m0srcs = (ifp->if_mtu - m0->m_pkthdr.len -
2812 			    sizeof(struct igmp_grouprec)) / sizeof(in_addr_t);
2813 		m = m0;
2814 		CTR1(KTR_IGMPV3, "%s: use existing packet", __func__);
2815 	} else {
2816 		if (mbufq_full(mq)) {
2817 			CTR1(KTR_IGMPV3, "%s: outbound queue full", __func__);
2818 			return (-ENOMEM);
2819 		}
2820 		m = NULL;
2821 		m0srcs = (ifp->if_mtu - IGMP_LEADINGSPACE -
2822 		    sizeof(struct igmp_grouprec)) / sizeof(in_addr_t);
2823 		if (!is_state_change && !is_group_query) {
2824 			m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2825 			if (m)
2826 				m->m_data += IGMP_LEADINGSPACE;
2827 		}
2828 		if (m == NULL) {
2829 			m = m_gethdr(M_NOWAIT, MT_DATA);
2830 			if (m)
2831 				M_ALIGN(m, IGMP_LEADINGSPACE);
2832 		}
2833 		if (m == NULL)
2834 			return (-ENOMEM);
2835 
2836 		igmp_save_context(m, ifp);
2837 
2838 		CTR1(KTR_IGMPV3, "%s: allocated first packet", __func__);
2839 	}
2840 
2841 	/*
2842 	 * Append group record.
2843 	 * If we have sources, we don't know how many yet.
2844 	 */
2845 	ig.ig_type = type;
2846 	ig.ig_datalen = 0;
2847 	ig.ig_numsrc = 0;
2848 	ig.ig_group = inm->inm_addr;
2849 	if (!m_append(m, sizeof(struct igmp_grouprec), (void *)&ig)) {
2850 		if (m != m0)
2851 			m_freem(m);
2852 		CTR1(KTR_IGMPV3, "%s: m_append() failed.", __func__);
2853 		return (-ENOMEM);
2854 	}
2855 	nbytes += sizeof(struct igmp_grouprec);
2856 
2857 	/*
2858 	 * Append as many sources as will fit in the first packet.
2859 	 * If we are appending to a new packet, the chain allocation
2860 	 * may potentially use clusters; use m_getptr() in this case.
2861 	 * If we are appending to an existing packet, we need to obtain
2862 	 * a pointer to the group record after m_append(), in case a new
2863 	 * mbuf was allocated.
2864 	 * Only append sources which are in-mode at t1. If we are
2865 	 * transitioning to MCAST_UNDEFINED state on the group, do not
2866 	 * include source entries.
2867 	 * Only report recorded sources in our filter set when responding
2868 	 * to a group-source query.
2869 	 */
2870 	if (record_has_sources) {
2871 		if (m == m0) {
2872 			md = m_last(m);
2873 			pig = (struct igmp_grouprec *)(mtod(md, uint8_t *) +
2874 			    md->m_len - nbytes);
2875 		} else {
2876 			md = m_getptr(m, 0, &off);
2877 			pig = (struct igmp_grouprec *)(mtod(md, uint8_t *) +
2878 			    off);
2879 		}
2880 		msrcs = 0;
2881 		RB_FOREACH_SAFE(ims, ip_msource_tree, &inm->inm_srcs, nims) {
2882 			CTR2(KTR_IGMPV3, "%s: visit node 0x%08x", __func__,
2883 			    ims->ims_haddr);
2884 			now = ims_get_mode(inm, ims, 1);
2885 			CTR2(KTR_IGMPV3, "%s: node is %d", __func__, now);
2886 			if ((now != mode) ||
2887 			    (now == mode && mode == MCAST_UNDEFINED)) {
2888 				CTR1(KTR_IGMPV3, "%s: skip node", __func__);
2889 				continue;
2890 			}
2891 			if (is_source_query && ims->ims_stp == 0) {
2892 				CTR1(KTR_IGMPV3, "%s: skip unrecorded node",
2893 				    __func__);
2894 				continue;
2895 			}
2896 			CTR1(KTR_IGMPV3, "%s: append node", __func__);
2897 			naddr = htonl(ims->ims_haddr);
2898 			if (!m_append(m, sizeof(in_addr_t), (void *)&naddr)) {
2899 				if (m != m0)
2900 					m_freem(m);
2901 				CTR1(KTR_IGMPV3, "%s: m_append() failed.",
2902 				    __func__);
2903 				return (-ENOMEM);
2904 			}
2905 			nbytes += sizeof(in_addr_t);
2906 			++msrcs;
2907 			if (msrcs == m0srcs)
2908 				break;
2909 		}
2910 		CTR2(KTR_IGMPV3, "%s: msrcs is %d this packet", __func__,
2911 		    msrcs);
2912 		pig->ig_numsrc = htons(msrcs);
2913 		nbytes += (msrcs * sizeof(in_addr_t));
2914 	}
2915 
2916 	if (is_source_query && msrcs == 0) {
2917 		CTR1(KTR_IGMPV3, "%s: no recorded sources to report", __func__);
2918 		if (m != m0)
2919 			m_freem(m);
2920 		return (0);
2921 	}
2922 
2923 	/*
2924 	 * We are good to go with first packet.
2925 	 */
2926 	if (m != m0) {
2927 		CTR1(KTR_IGMPV3, "%s: enqueueing first packet", __func__);
2928 		m->m_pkthdr.PH_vt.vt_nrecs = 1;
2929 		mbufq_enqueue(mq, m);
2930 	} else
2931 		m->m_pkthdr.PH_vt.vt_nrecs++;
2932 
2933 	/*
2934 	 * No further work needed if no source list in packet(s).
2935 	 */
2936 	if (!record_has_sources)
2937 		return (nbytes);
2938 
2939 	/*
2940 	 * Whilst sources remain to be announced, we need to allocate
2941 	 * a new packet and fill out as many sources as will fit.
2942 	 * Always try for a cluster first.
2943 	 */
2944 	while (nims != NULL) {
2945 		if (mbufq_full(mq)) {
2946 			CTR1(KTR_IGMPV3, "%s: outbound queue full", __func__);
2947 			return (-ENOMEM);
2948 		}
2949 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2950 		if (m)
2951 			m->m_data += IGMP_LEADINGSPACE;
2952 		if (m == NULL) {
2953 			m = m_gethdr(M_NOWAIT, MT_DATA);
2954 			if (m)
2955 				M_ALIGN(m, IGMP_LEADINGSPACE);
2956 		}
2957 		if (m == NULL)
2958 			return (-ENOMEM);
2959 		igmp_save_context(m, ifp);
2960 		md = m_getptr(m, 0, &off);
2961 		pig = (struct igmp_grouprec *)(mtod(md, uint8_t *) + off);
2962 		CTR1(KTR_IGMPV3, "%s: allocated next packet", __func__);
2963 
2964 		if (!m_append(m, sizeof(struct igmp_grouprec), (void *)&ig)) {
2965 			if (m != m0)
2966 				m_freem(m);
2967 			CTR1(KTR_IGMPV3, "%s: m_append() failed.", __func__);
2968 			return (-ENOMEM);
2969 		}
2970 		m->m_pkthdr.PH_vt.vt_nrecs = 1;
2971 		nbytes += sizeof(struct igmp_grouprec);
2972 
2973 		m0srcs = (ifp->if_mtu - IGMP_LEADINGSPACE -
2974 		    sizeof(struct igmp_grouprec)) / sizeof(in_addr_t);
2975 
2976 		msrcs = 0;
2977 		RB_FOREACH_FROM(ims, ip_msource_tree, nims) {
2978 			CTR2(KTR_IGMPV3, "%s: visit node 0x%08x", __func__,
2979 			    ims->ims_haddr);
2980 			now = ims_get_mode(inm, ims, 1);
2981 			if ((now != mode) ||
2982 			    (now == mode && mode == MCAST_UNDEFINED)) {
2983 				CTR1(KTR_IGMPV3, "%s: skip node", __func__);
2984 				continue;
2985 			}
2986 			if (is_source_query && ims->ims_stp == 0) {
2987 				CTR1(KTR_IGMPV3, "%s: skip unrecorded node",
2988 				    __func__);
2989 				continue;
2990 			}
2991 			CTR1(KTR_IGMPV3, "%s: append node", __func__);
2992 			naddr = htonl(ims->ims_haddr);
2993 			if (!m_append(m, sizeof(in_addr_t), (void *)&naddr)) {
2994 				if (m != m0)
2995 					m_freem(m);
2996 				CTR1(KTR_IGMPV3, "%s: m_append() failed.",
2997 				    __func__);
2998 				return (-ENOMEM);
2999 			}
3000 			++msrcs;
3001 			if (msrcs == m0srcs)
3002 				break;
3003 		}
3004 		pig->ig_numsrc = htons(msrcs);
3005 		nbytes += (msrcs * sizeof(in_addr_t));
3006 
3007 		CTR1(KTR_IGMPV3, "%s: enqueueing next packet", __func__);
3008 		mbufq_enqueue(mq, m);
3009 	}
3010 
3011 	return (nbytes);
3012 }
3013 
3014 /*
3015  * Type used to mark record pass completion.
3016  * We exploit the fact we can cast to this easily from the
3017  * current filter modes on each ip_msource node.
3018  */
3019 typedef enum {
3020 	REC_NONE = 0x00,	/* MCAST_UNDEFINED */
3021 	REC_ALLOW = 0x01,	/* MCAST_INCLUDE */
3022 	REC_BLOCK = 0x02,	/* MCAST_EXCLUDE */
3023 	REC_FULL = REC_ALLOW | REC_BLOCK
3024 } rectype_t;
3025 
3026 /*
3027  * Enqueue an IGMPv3 filter list change to the given output queue.
3028  *
3029  * Source list filter state is held in an RB-tree. When the filter list
3030  * for a group is changed without changing its mode, we need to compute
3031  * the deltas between T0 and T1 for each source in the filter set,
3032  * and enqueue the appropriate ALLOW_NEW/BLOCK_OLD records.
3033  *
3034  * As we may potentially queue two record types, and the entire R-B tree
3035  * needs to be walked at once, we break this out into its own function
3036  * so we can generate a tightly packed queue of packets.
3037  *
3038  * XXX This could be written to only use one tree walk, although that makes
3039  * serializing into the mbuf chains a bit harder. For now we do two walks
3040  * which makes things easier on us, and it may or may not be harder on
3041  * the L2 cache.
3042  *
3043  * If successful the size of all data appended to the queue is returned,
3044  * otherwise an error code less than zero is returned, or zero if
3045  * no record(s) were appended.
3046  */
3047 static int
3048 igmp_v3_enqueue_filter_change(struct mbufq *mq, struct in_multi *inm)
3049 {
3050 	static const int MINRECLEN =
3051 	    sizeof(struct igmp_grouprec) + sizeof(in_addr_t);
3052 	struct ifnet		*ifp;
3053 	struct igmp_grouprec	 ig;
3054 	struct igmp_grouprec	*pig;
3055 	struct ip_msource	*ims, *nims;
3056 	struct mbuf		*m, *m0, *md;
3057 	in_addr_t		 naddr;
3058 	int			 m0srcs, nbytes, npbytes, off, rsrcs, schanged;
3059 	int			 nallow, nblock;
3060 	uint8_t			 mode, now, then;
3061 	rectype_t		 crt, drt, nrt;
3062 
3063 	IN_MULTI_LIST_LOCK_ASSERT();
3064 
3065 	if (inm->inm_nsrc == 0 ||
3066 	    (inm->inm_st[0].iss_asm > 0 && inm->inm_st[1].iss_asm > 0))
3067 		return (0);
3068 
3069 	ifp = inm->inm_ifp;			/* interface */
3070 	mode = inm->inm_st[1].iss_fmode;	/* filter mode at t1 */
3071 	crt = REC_NONE;	/* current group record type */
3072 	drt = REC_NONE;	/* mask of completed group record types */
3073 	nrt = REC_NONE;	/* record type for current node */
3074 	m0srcs = 0;	/* # source which will fit in current mbuf chain */
3075 	nbytes = 0;	/* # of bytes appended to group's state-change queue */
3076 	npbytes = 0;	/* # of bytes appended this packet */
3077 	rsrcs = 0;	/* # sources encoded in current record */
3078 	schanged = 0;	/* # nodes encoded in overall filter change */
3079 	nallow = 0;	/* # of source entries in ALLOW_NEW */
3080 	nblock = 0;	/* # of source entries in BLOCK_OLD */
3081 	nims = NULL;	/* next tree node pointer */
3082 
3083 	/*
3084 	 * For each possible filter record mode.
3085 	 * The first kind of source we encounter tells us which
3086 	 * is the first kind of record we start appending.
3087 	 * If a node transitioned to UNDEFINED at t1, its mode is treated
3088 	 * as the inverse of the group's filter mode.
3089 	 */
3090 	while (drt != REC_FULL) {
3091 		do {
3092 			m0 = mbufq_last(mq);
3093 			if (m0 != NULL &&
3094 			    (m0->m_pkthdr.PH_vt.vt_nrecs + 1 <=
3095 			     IGMP_V3_REPORT_MAXRECS) &&
3096 			    (m0->m_pkthdr.len + MINRECLEN) <
3097 			     (ifp->if_mtu - IGMP_LEADINGSPACE)) {
3098 				m = m0;
3099 				m0srcs = (ifp->if_mtu - m0->m_pkthdr.len -
3100 					    sizeof(struct igmp_grouprec)) /
3101 				    sizeof(in_addr_t);
3102 				CTR1(KTR_IGMPV3,
3103 				    "%s: use previous packet", __func__);
3104 			} else {
3105 				m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
3106 				if (m)
3107 					m->m_data += IGMP_LEADINGSPACE;
3108 				if (m == NULL) {
3109 					m = m_gethdr(M_NOWAIT, MT_DATA);
3110 					if (m)
3111 						M_ALIGN(m, IGMP_LEADINGSPACE);
3112 				}
3113 				if (m == NULL) {
3114 					CTR1(KTR_IGMPV3,
3115 					    "%s: m_get*() failed", __func__);
3116 					return (-ENOMEM);
3117 				}
3118 				m->m_pkthdr.PH_vt.vt_nrecs = 0;
3119 				igmp_save_context(m, ifp);
3120 				m0srcs = (ifp->if_mtu - IGMP_LEADINGSPACE -
3121 				    sizeof(struct igmp_grouprec)) /
3122 				    sizeof(in_addr_t);
3123 				npbytes = 0;
3124 				CTR1(KTR_IGMPV3,
3125 				    "%s: allocated new packet", __func__);
3126 			}
3127 			/*
3128 			 * Append the IGMP group record header to the
3129 			 * current packet's data area.
3130 			 * Recalculate pointer to free space for next
3131 			 * group record, in case m_append() allocated
3132 			 * a new mbuf or cluster.
3133 			 */
3134 			memset(&ig, 0, sizeof(ig));
3135 			ig.ig_group = inm->inm_addr;
3136 			if (!m_append(m, sizeof(ig), (void *)&ig)) {
3137 				if (m != m0)
3138 					m_freem(m);
3139 				CTR1(KTR_IGMPV3,
3140 				    "%s: m_append() failed", __func__);
3141 				return (-ENOMEM);
3142 			}
3143 			npbytes += sizeof(struct igmp_grouprec);
3144 			if (m != m0) {
3145 				/* new packet; offset in c hain */
3146 				md = m_getptr(m, npbytes -
3147 				    sizeof(struct igmp_grouprec), &off);
3148 				pig = (struct igmp_grouprec *)(mtod(md,
3149 				    uint8_t *) + off);
3150 			} else {
3151 				/* current packet; offset from last append */
3152 				md = m_last(m);
3153 				pig = (struct igmp_grouprec *)(mtod(md,
3154 				    uint8_t *) + md->m_len -
3155 				    sizeof(struct igmp_grouprec));
3156 			}
3157 			/*
3158 			 * Begin walking the tree for this record type
3159 			 * pass, or continue from where we left off
3160 			 * previously if we had to allocate a new packet.
3161 			 * Only report deltas in-mode at t1.
3162 			 * We need not report included sources as allowed
3163 			 * if we are in inclusive mode on the group,
3164 			 * however the converse is not true.
3165 			 */
3166 			rsrcs = 0;
3167 			if (nims == NULL)
3168 				nims = RB_MIN(ip_msource_tree, &inm->inm_srcs);
3169 			RB_FOREACH_FROM(ims, ip_msource_tree, nims) {
3170 				CTR2(KTR_IGMPV3, "%s: visit node 0x%08x",
3171 				    __func__, ims->ims_haddr);
3172 				now = ims_get_mode(inm, ims, 1);
3173 				then = ims_get_mode(inm, ims, 0);
3174 				CTR3(KTR_IGMPV3, "%s: mode: t0 %d, t1 %d",
3175 				    __func__, then, now);
3176 				if (now == then) {
3177 					CTR1(KTR_IGMPV3,
3178 					    "%s: skip unchanged", __func__);
3179 					continue;
3180 				}
3181 				if (mode == MCAST_EXCLUDE &&
3182 				    now == MCAST_INCLUDE) {
3183 					CTR1(KTR_IGMPV3,
3184 					    "%s: skip IN src on EX group",
3185 					    __func__);
3186 					continue;
3187 				}
3188 				nrt = (rectype_t)now;
3189 				if (nrt == REC_NONE)
3190 					nrt = (rectype_t)(~mode & REC_FULL);
3191 				if (schanged++ == 0) {
3192 					crt = nrt;
3193 				} else if (crt != nrt)
3194 					continue;
3195 				naddr = htonl(ims->ims_haddr);
3196 				if (!m_append(m, sizeof(in_addr_t),
3197 				    (void *)&naddr)) {
3198 					if (m != m0)
3199 						m_freem(m);
3200 					CTR1(KTR_IGMPV3,
3201 					    "%s: m_append() failed", __func__);
3202 					return (-ENOMEM);
3203 				}
3204 				nallow += !!(crt == REC_ALLOW);
3205 				nblock += !!(crt == REC_BLOCK);
3206 				if (++rsrcs == m0srcs)
3207 					break;
3208 			}
3209 			/*
3210 			 * If we did not append any tree nodes on this
3211 			 * pass, back out of allocations.
3212 			 */
3213 			if (rsrcs == 0) {
3214 				npbytes -= sizeof(struct igmp_grouprec);
3215 				if (m != m0) {
3216 					CTR1(KTR_IGMPV3,
3217 					    "%s: m_free(m)", __func__);
3218 					m_freem(m);
3219 				} else {
3220 					CTR1(KTR_IGMPV3,
3221 					    "%s: m_adj(m, -ig)", __func__);
3222 					m_adj(m, -((int)sizeof(
3223 					    struct igmp_grouprec)));
3224 				}
3225 				continue;
3226 			}
3227 			npbytes += (rsrcs * sizeof(in_addr_t));
3228 			if (crt == REC_ALLOW)
3229 				pig->ig_type = IGMP_ALLOW_NEW_SOURCES;
3230 			else if (crt == REC_BLOCK)
3231 				pig->ig_type = IGMP_BLOCK_OLD_SOURCES;
3232 			pig->ig_numsrc = htons(rsrcs);
3233 			/*
3234 			 * Count the new group record, and enqueue this
3235 			 * packet if it wasn't already queued.
3236 			 */
3237 			m->m_pkthdr.PH_vt.vt_nrecs++;
3238 			if (m != m0)
3239 				mbufq_enqueue(mq, m);
3240 			nbytes += npbytes;
3241 		} while (nims != NULL);
3242 		drt |= crt;
3243 		crt = (~crt & REC_FULL);
3244 	}
3245 
3246 	CTR3(KTR_IGMPV3, "%s: queued %d ALLOW_NEW, %d BLOCK_OLD", __func__,
3247 	    nallow, nblock);
3248 
3249 	return (nbytes);
3250 }
3251 
3252 static int
3253 igmp_v3_merge_state_changes(struct in_multi *inm, struct mbufq *scq)
3254 {
3255 	struct mbufq	*gq;
3256 	struct mbuf	*m;		/* pending state-change */
3257 	struct mbuf	*m0;		/* copy of pending state-change */
3258 	struct mbuf	*mt;		/* last state-change in packet */
3259 	int		 docopy, domerge;
3260 	u_int		 recslen;
3261 
3262 	docopy = 0;
3263 	domerge = 0;
3264 	recslen = 0;
3265 
3266 	IN_MULTI_LIST_LOCK_ASSERT();
3267 	IGMP_LOCK_ASSERT();
3268 
3269 	/*
3270 	 * If there are further pending retransmissions, make a writable
3271 	 * copy of each queued state-change message before merging.
3272 	 */
3273 	if (inm->inm_scrv > 0)
3274 		docopy = 1;
3275 
3276 	gq = &inm->inm_scq;
3277 #ifdef KTR
3278 	if (mbufq_first(gq) == NULL) {
3279 		CTR2(KTR_IGMPV3, "%s: WARNING: queue for inm %p is empty",
3280 		    __func__, inm);
3281 	}
3282 #endif
3283 
3284 	m = mbufq_first(gq);
3285 	while (m != NULL) {
3286 		/*
3287 		 * Only merge the report into the current packet if
3288 		 * there is sufficient space to do so; an IGMPv3 report
3289 		 * packet may only contain 65,535 group records.
3290 		 * Always use a simple mbuf chain concatentation to do this,
3291 		 * as large state changes for single groups may have
3292 		 * allocated clusters.
3293 		 */
3294 		domerge = 0;
3295 		mt = mbufq_last(scq);
3296 		if (mt != NULL) {
3297 			recslen = m_length(m, NULL);
3298 
3299 			if ((mt->m_pkthdr.PH_vt.vt_nrecs +
3300 			    m->m_pkthdr.PH_vt.vt_nrecs <=
3301 			    IGMP_V3_REPORT_MAXRECS) &&
3302 			    (mt->m_pkthdr.len + recslen <=
3303 			    (inm->inm_ifp->if_mtu - IGMP_LEADINGSPACE)))
3304 				domerge = 1;
3305 		}
3306 
3307 		if (!domerge && mbufq_full(gq)) {
3308 			CTR2(KTR_IGMPV3,
3309 			    "%s: outbound queue full, skipping whole packet %p",
3310 			    __func__, m);
3311 			mt = m->m_nextpkt;
3312 			if (!docopy)
3313 				m_freem(m);
3314 			m = mt;
3315 			continue;
3316 		}
3317 
3318 		if (!docopy) {
3319 			CTR2(KTR_IGMPV3, "%s: dequeueing %p", __func__, m);
3320 			m0 = mbufq_dequeue(gq);
3321 			m = m0->m_nextpkt;
3322 		} else {
3323 			CTR2(KTR_IGMPV3, "%s: copying %p", __func__, m);
3324 			m0 = m_dup(m, M_NOWAIT);
3325 			if (m0 == NULL)
3326 				return (ENOMEM);
3327 			m0->m_nextpkt = NULL;
3328 			m = m->m_nextpkt;
3329 		}
3330 
3331 		if (!domerge) {
3332 			CTR3(KTR_IGMPV3, "%s: queueing %p to scq %p)",
3333 			    __func__, m0, scq);
3334 			mbufq_enqueue(scq, m0);
3335 		} else {
3336 			struct mbuf *mtl;	/* last mbuf of packet mt */
3337 
3338 			CTR3(KTR_IGMPV3, "%s: merging %p with scq tail %p)",
3339 			    __func__, m0, mt);
3340 
3341 			mtl = m_last(mt);
3342 			m0->m_flags &= ~M_PKTHDR;
3343 			mt->m_pkthdr.len += recslen;
3344 			mt->m_pkthdr.PH_vt.vt_nrecs +=
3345 			    m0->m_pkthdr.PH_vt.vt_nrecs;
3346 
3347 			mtl->m_next = m0;
3348 		}
3349 	}
3350 
3351 	return (0);
3352 }
3353 
3354 /*
3355  * Respond to a pending IGMPv3 General Query.
3356  */
3357 static void
3358 igmp_v3_dispatch_general_query(struct igmp_ifsoftc *igi)
3359 {
3360 	struct ifmultiaddr	*ifma;
3361 	struct ifnet		*ifp;
3362 	struct in_multi		*inm;
3363 	int			 retval __unused, loop;
3364 
3365 	IN_MULTI_LIST_LOCK_ASSERT();
3366 	IGMP_LOCK_ASSERT();
3367 	NET_EPOCH_ASSERT();
3368 
3369 	KASSERT(igi->igi_version == IGMP_VERSION_3,
3370 	    ("%s: called when version %d", __func__, igi->igi_version));
3371 
3372 	/*
3373 	 * Check that there are some packets queued. If so, send them first.
3374 	 * For large number of groups the reply to general query can take
3375 	 * many packets, we should finish sending them before starting of
3376 	 * queuing the new reply.
3377 	 */
3378 	if (mbufq_len(&igi->igi_gq) != 0)
3379 		goto send;
3380 
3381 	ifp = igi->igi_ifp;
3382 
3383 	CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
3384 		if (ifma->ifma_addr->sa_family != AF_INET ||
3385 		    ifma->ifma_protospec == NULL)
3386 			continue;
3387 
3388 		inm = (struct in_multi *)ifma->ifma_protospec;
3389 		KASSERT(ifp == inm->inm_ifp,
3390 		    ("%s: inconsistent ifp", __func__));
3391 
3392 		switch (inm->inm_state) {
3393 		case IGMP_NOT_MEMBER:
3394 		case IGMP_SILENT_MEMBER:
3395 			break;
3396 		case IGMP_REPORTING_MEMBER:
3397 		case IGMP_IDLE_MEMBER:
3398 		case IGMP_LAZY_MEMBER:
3399 		case IGMP_SLEEPING_MEMBER:
3400 		case IGMP_AWAKENING_MEMBER:
3401 			inm->inm_state = IGMP_REPORTING_MEMBER;
3402 			retval = igmp_v3_enqueue_group_record(&igi->igi_gq,
3403 			    inm, 0, 0, 0);
3404 			CTR2(KTR_IGMPV3, "%s: enqueue record = %d",
3405 			    __func__, retval);
3406 			break;
3407 		case IGMP_G_QUERY_PENDING_MEMBER:
3408 		case IGMP_SG_QUERY_PENDING_MEMBER:
3409 		case IGMP_LEAVING_MEMBER:
3410 			break;
3411 		}
3412 	}
3413 
3414 send:
3415 	loop = (igi->igi_flags & IGIF_LOOPBACK) ? 1 : 0;
3416 	igmp_dispatch_queue(&igi->igi_gq, IGMP_MAX_RESPONSE_BURST, loop);
3417 
3418 	/*
3419 	 * Slew transmission of bursts over 500ms intervals.
3420 	 */
3421 	if (mbufq_first(&igi->igi_gq) != NULL) {
3422 		igi->igi_v3_timer = 1 + IGMP_RANDOM_DELAY(
3423 		    IGMP_RESPONSE_BURST_INTERVAL);
3424 		V_interface_timers_running = 1;
3425 	}
3426 }
3427 
3428 /*
3429  * Transmit the next pending IGMP message in the output queue.
3430  *
3431  * We get called from netisr_processqueue(). A mutex private to igmpoq
3432  * will be acquired and released around this routine.
3433  *
3434  * VIMAGE: Needs to store/restore vnet pointer on a per-mbuf-chain basis.
3435  * MRT: Nothing needs to be done, as IGMP traffic is always local to
3436  * a link and uses a link-scope multicast address.
3437  */
3438 static void
3439 igmp_intr(struct mbuf *m)
3440 {
3441 	struct ip_moptions	 imo;
3442 	struct ifnet		*ifp;
3443 	struct mbuf		*ipopts, *m0;
3444 	int			 error;
3445 	uint32_t		 ifindex;
3446 
3447 	CTR2(KTR_IGMPV3, "%s: transmit %p", __func__, m);
3448 
3449 	/*
3450 	 * Set VNET image pointer from enqueued mbuf chain
3451 	 * before doing anything else. Whilst we use interface
3452 	 * indexes to guard against interface detach, they are
3453 	 * unique to each VIMAGE and must be retrieved.
3454 	 */
3455 	CURVNET_SET((struct vnet *)(m->m_pkthdr.PH_loc.ptr));
3456 	ifindex = igmp_restore_context(m);
3457 
3458 	/*
3459 	 * Check if the ifnet still exists. This limits the scope of
3460 	 * any race in the absence of a global ifp lock for low cost
3461 	 * (an array lookup).
3462 	 */
3463 	ifp = ifnet_byindex(ifindex);
3464 	if (ifp == NULL) {
3465 		CTR3(KTR_IGMPV3, "%s: dropped %p as ifindex %u went away.",
3466 		    __func__, m, ifindex);
3467 		m_freem(m);
3468 		IPSTAT_INC(ips_noroute);
3469 		goto out;
3470 	}
3471 
3472 	ipopts = V_igmp_sendra ? m_raopt : NULL;
3473 
3474 	imo.imo_multicast_ttl  = 1;
3475 	imo.imo_multicast_vif  = -1;
3476 	imo.imo_multicast_loop = (V_ip_mrouter != NULL);
3477 
3478 	/*
3479 	 * If the user requested that IGMP traffic be explicitly
3480 	 * redirected to the loopback interface (e.g. they are running a
3481 	 * MANET interface and the routing protocol needs to see the
3482 	 * updates), handle this now.
3483 	 */
3484 	if (m->m_flags & M_IGMP_LOOP)
3485 		imo.imo_multicast_ifp = V_loif;
3486 	else
3487 		imo.imo_multicast_ifp = ifp;
3488 
3489 	if (m->m_flags & M_IGMPV2) {
3490 		m0 = m;
3491 	} else {
3492 		m0 = igmp_v3_encap_report(ifp, m);
3493 		if (m0 == NULL) {
3494 			CTR2(KTR_IGMPV3, "%s: dropped %p", __func__, m);
3495 			m_freem(m);
3496 			IPSTAT_INC(ips_odropped);
3497 			goto out;
3498 		}
3499 	}
3500 
3501 	igmp_scrub_context(m0);
3502 	m_clrprotoflags(m);
3503 	m0->m_pkthdr.rcvif = V_loif;
3504 #ifdef MAC
3505 	mac_netinet_igmp_send(ifp, m0);
3506 #endif
3507 	error = ip_output(m0, ipopts, NULL, 0, &imo, NULL);
3508 	if (error) {
3509 		CTR3(KTR_IGMPV3, "%s: ip_output(%p) = %d", __func__, m0, error);
3510 		goto out;
3511 	}
3512 
3513 	IGMPSTAT_INC(igps_snd_reports);
3514 
3515 out:
3516 	/*
3517 	 * We must restore the existing vnet pointer before
3518 	 * continuing as we are run from netisr context.
3519 	 */
3520 	CURVNET_RESTORE();
3521 }
3522 
3523 /*
3524  * Encapsulate an IGMPv3 report.
3525  *
3526  * The internal mbuf flag M_IGMPV3_HDR is used to indicate that the mbuf
3527  * chain has already had its IP/IGMPv3 header prepended. In this case
3528  * the function will not attempt to prepend; the lengths and checksums
3529  * will however be re-computed.
3530  *
3531  * Returns a pointer to the new mbuf chain head, or NULL if the
3532  * allocation failed.
3533  */
3534 static struct mbuf *
3535 igmp_v3_encap_report(struct ifnet *ifp, struct mbuf *m)
3536 {
3537 	struct rm_priotracker	in_ifa_tracker;
3538 	struct igmp_report	*igmp;
3539 	struct ip		*ip;
3540 	int			 hdrlen, igmpreclen;
3541 
3542 	KASSERT((m->m_flags & M_PKTHDR),
3543 	    ("%s: mbuf chain %p is !M_PKTHDR", __func__, m));
3544 
3545 	igmpreclen = m_length(m, NULL);
3546 	hdrlen = sizeof(struct ip) + sizeof(struct igmp_report);
3547 
3548 	if (m->m_flags & M_IGMPV3_HDR) {
3549 		igmpreclen -= hdrlen;
3550 	} else {
3551 		M_PREPEND(m, hdrlen, M_NOWAIT);
3552 		if (m == NULL)
3553 			return (NULL);
3554 		m->m_flags |= M_IGMPV3_HDR;
3555 	}
3556 
3557 	CTR2(KTR_IGMPV3, "%s: igmpreclen is %d", __func__, igmpreclen);
3558 
3559 	m->m_data += sizeof(struct ip);
3560 	m->m_len -= sizeof(struct ip);
3561 
3562 	igmp = mtod(m, struct igmp_report *);
3563 	igmp->ir_type = IGMP_v3_HOST_MEMBERSHIP_REPORT;
3564 	igmp->ir_rsv1 = 0;
3565 	igmp->ir_rsv2 = 0;
3566 	igmp->ir_numgrps = htons(m->m_pkthdr.PH_vt.vt_nrecs);
3567 	igmp->ir_cksum = 0;
3568 	igmp->ir_cksum = in_cksum(m, sizeof(struct igmp_report) + igmpreclen);
3569 	m->m_pkthdr.PH_vt.vt_nrecs = 0;
3570 
3571 	m->m_data -= sizeof(struct ip);
3572 	m->m_len += sizeof(struct ip);
3573 
3574 	ip = mtod(m, struct ip *);
3575 	ip->ip_tos = IPTOS_PREC_INTERNETCONTROL;
3576 	ip->ip_len = htons(hdrlen + igmpreclen);
3577 	ip->ip_off = htons(IP_DF);
3578 	ip->ip_p = IPPROTO_IGMP;
3579 	ip->ip_sum = 0;
3580 
3581 	ip->ip_src.s_addr = INADDR_ANY;
3582 
3583 	if (m->m_flags & M_IGMP_LOOP) {
3584 		struct in_ifaddr *ia;
3585 
3586 		IFP_TO_IA(ifp, ia, &in_ifa_tracker);
3587 		if (ia != NULL)
3588 			ip->ip_src = ia->ia_addr.sin_addr;
3589 	}
3590 
3591 	ip->ip_dst.s_addr = htonl(INADDR_ALLRPTS_GROUP);
3592 
3593 	return (m);
3594 }
3595 
3596 #ifdef KTR
3597 static char *
3598 igmp_rec_type_to_str(const int type)
3599 {
3600 
3601 	switch (type) {
3602 		case IGMP_CHANGE_TO_EXCLUDE_MODE:
3603 			return "TO_EX";
3604 			break;
3605 		case IGMP_CHANGE_TO_INCLUDE_MODE:
3606 			return "TO_IN";
3607 			break;
3608 		case IGMP_MODE_IS_EXCLUDE:
3609 			return "MODE_EX";
3610 			break;
3611 		case IGMP_MODE_IS_INCLUDE:
3612 			return "MODE_IN";
3613 			break;
3614 		case IGMP_ALLOW_NEW_SOURCES:
3615 			return "ALLOW_NEW";
3616 			break;
3617 		case IGMP_BLOCK_OLD_SOURCES:
3618 			return "BLOCK_OLD";
3619 			break;
3620 		default:
3621 			break;
3622 	}
3623 	return "unknown";
3624 }
3625 #endif
3626 
3627 #ifdef VIMAGE
3628 static void
3629 vnet_igmp_init(const void *unused __unused)
3630 {
3631 
3632 	netisr_register_vnet(&igmp_nh);
3633 }
3634 VNET_SYSINIT(vnet_igmp_init, SI_SUB_PROTO_MC, SI_ORDER_ANY,
3635     vnet_igmp_init, NULL);
3636 
3637 static void
3638 vnet_igmp_uninit(const void *unused __unused)
3639 {
3640 
3641 	/* This can happen when we shutdown the entire network stack. */
3642 	CTR1(KTR_IGMPV3, "%s: tearing down", __func__);
3643 
3644 	netisr_unregister_vnet(&igmp_nh);
3645 }
3646 VNET_SYSUNINIT(vnet_igmp_uninit, SI_SUB_PROTO_MC, SI_ORDER_ANY,
3647     vnet_igmp_uninit, NULL);
3648 #endif
3649 
3650 #ifdef DDB
3651 DB_SHOW_COMMAND(igi_list, db_show_igi_list)
3652 {
3653 	struct igmp_ifsoftc *igi, *tigi;
3654 	LIST_HEAD(_igi_list, igmp_ifsoftc) *igi_head;
3655 
3656 	if (!have_addr) {
3657 		db_printf("usage: show igi_list <addr>\n");
3658 		return;
3659 	}
3660 	igi_head = (struct _igi_list *)addr;
3661 
3662 	LIST_FOREACH_SAFE(igi, igi_head, igi_link, tigi) {
3663 		db_printf("igmp_ifsoftc %p:\n", igi);
3664 		db_printf("    ifp %p\n", igi->igi_ifp);
3665 		db_printf("    version %u\n", igi->igi_version);
3666 		db_printf("    v1_timer %u\n", igi->igi_v1_timer);
3667 		db_printf("    v2_timer %u\n", igi->igi_v2_timer);
3668 		db_printf("    v3_timer %u\n", igi->igi_v3_timer);
3669 		db_printf("    flags %#x\n", igi->igi_flags);
3670 		db_printf("    rv %u\n", igi->igi_rv);
3671 		db_printf("    qi %u\n", igi->igi_qi);
3672 		db_printf("    qri %u\n", igi->igi_qri);
3673 		db_printf("    uri %u\n", igi->igi_uri);
3674 		/* struct mbufq    igi_gq; */
3675 		db_printf("\n");
3676 	}
3677 }
3678 #endif
3679 
3680 static int
3681 igmp_modevent(module_t mod, int type, void *unused __unused)
3682 {
3683 
3684 	switch (type) {
3685 	case MOD_LOAD:
3686 		CTR1(KTR_IGMPV3, "%s: initializing", __func__);
3687 		IGMP_LOCK_INIT();
3688 		m_raopt = igmp_ra_alloc();
3689 		netisr_register(&igmp_nh);
3690 		break;
3691 	case MOD_UNLOAD:
3692 		CTR1(KTR_IGMPV3, "%s: tearing down", __func__);
3693 		netisr_unregister(&igmp_nh);
3694 		m_free(m_raopt);
3695 		m_raopt = NULL;
3696 		IGMP_LOCK_DESTROY();
3697 		break;
3698 	default:
3699 		return (EOPNOTSUPP);
3700 	}
3701 	return (0);
3702 }
3703 
3704 static moduledata_t igmp_mod = {
3705     "igmp",
3706     igmp_modevent,
3707     0
3708 };
3709 DECLARE_MODULE(igmp, igmp_mod, SI_SUB_PROTO_MC, SI_ORDER_MIDDLE);
3710