mld6.c revision 174510
1/*-
2 * Copyright (C) 1998 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 *	$KAME: mld6.c,v 1.27 2001/04/04 05:17:30 itojun Exp $
30 */
31
32/*-
33 * Copyright (c) 1988 Stephen Deering.
34 * Copyright (c) 1992, 1993
35 *	The Regents of the University of California.  All rights reserved.
36 *
37 * This code is derived from software contributed to Berkeley by
38 * Stephen Deering of Stanford University.
39 *
40 * Redistribution and use in source and binary forms, with or without
41 * modification, are permitted provided that the following conditions
42 * are met:
43 * 1. Redistributions of source code must retain the above copyright
44 *    notice, this list of conditions and the following disclaimer.
45 * 2. Redistributions in binary form must reproduce the above copyright
46 *    notice, this list of conditions and the following disclaimer in the
47 *    documentation and/or other materials provided with the distribution.
48 * 4. Neither the name of the University nor the names of its contributors
49 *    may be used to endorse or promote products derived from this software
50 *    without specific prior written permission.
51 *
52 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
53 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
54 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
55 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
56 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
57 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
58 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
59 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
60 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
61 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
62 * SUCH DAMAGE.
63 *
64 *	@(#)igmp.c	8.1 (Berkeley) 7/19/93
65 */
66
67#include <sys/cdefs.h>
68__FBSDID("$FreeBSD: head/sys/netinet6/mld6.c 174510 2007-12-10 16:03:40Z obrien $");
69
70#include "opt_inet.h"
71#include "opt_inet6.h"
72
73#include <sys/param.h>
74#include <sys/systm.h>
75#include <sys/mbuf.h>
76#include <sys/socket.h>
77#include <sys/protosw.h>
78#include <sys/syslog.h>
79#include <sys/kernel.h>
80#include <sys/callout.h>
81#include <sys/malloc.h>
82
83#include <net/if.h>
84
85#include <netinet/in.h>
86#include <netinet/in_var.h>
87#include <netinet6/in6_var.h>
88#include <netinet/ip6.h>
89#include <netinet6/ip6_var.h>
90#include <netinet6/scope6_var.h>
91#include <netinet/icmp6.h>
92#include <netinet6/mld6_var.h>
93
94/*
95 * Protocol constants
96 */
97
98/* denotes that the MLD max response delay field specifies time in milliseconds */
99#define MLD_TIMER_SCALE	1000
100/*
101 * time between repetitions of a node's initial report of interest in a
102 * multicast address(in seconds)
103 */
104#define MLD_UNSOLICITED_REPORT_INTERVAL	10
105
106static struct ip6_pktopts ip6_opts;
107
108static void mld6_sendpkt(struct in6_multi *, int, const struct in6_addr *);
109static void mld_starttimer(struct in6_multi *);
110static void mld_stoptimer(struct in6_multi *);
111static void mld_timeo(struct in6_multi *);
112static u_long mld_timerresid(struct in6_multi *);
113
114void
115mld6_init(void)
116{
117	static u_int8_t hbh_buf[8];
118	struct ip6_hbh *hbh = (struct ip6_hbh *)hbh_buf;
119	u_int16_t rtalert_code = htons((u_int16_t)IP6OPT_RTALERT_MLD);
120
121	/* ip6h_nxt will be fill in later */
122	hbh->ip6h_len = 0;	/* (8 >> 3) - 1 */
123
124	/* XXX: grotty hard coding... */
125	hbh_buf[2] = IP6OPT_PADN;	/* 2 byte padding */
126	hbh_buf[3] = 0;
127	hbh_buf[4] = IP6OPT_ROUTER_ALERT;
128	hbh_buf[5] = IP6OPT_RTALERT_LEN - 2;
129	bcopy((caddr_t)&rtalert_code, &hbh_buf[6], sizeof(u_int16_t));
130
131	ip6_initpktopts(&ip6_opts);
132	ip6_opts.ip6po_hbh = hbh;
133}
134
135static void
136mld_starttimer(struct in6_multi *in6m)
137{
138	struct timeval now;
139
140	microtime(&now);
141	in6m->in6m_timer_expire.tv_sec = now.tv_sec + in6m->in6m_timer / hz;
142	in6m->in6m_timer_expire.tv_usec = now.tv_usec +
143	    (in6m->in6m_timer % hz) * (1000000 / hz);
144	if (in6m->in6m_timer_expire.tv_usec > 1000000) {
145		in6m->in6m_timer_expire.tv_sec++;
146		in6m->in6m_timer_expire.tv_usec -= 1000000;
147	}
148
149	/* start or restart the timer */
150	callout_reset(in6m->in6m_timer_ch, in6m->in6m_timer,
151	    (void (*) __P((void *)))mld_timeo, in6m);
152}
153
154static void
155mld_stoptimer(struct in6_multi *in6m)
156{
157	if (in6m->in6m_timer == IN6M_TIMER_UNDEF)
158		return;
159
160	callout_stop(in6m->in6m_timer_ch);
161	in6m->in6m_timer = IN6M_TIMER_UNDEF;
162}
163
164static void
165mld_timeo(struct in6_multi *in6m)
166{
167	int s = splnet();
168
169	in6m->in6m_timer = IN6M_TIMER_UNDEF;
170
171	callout_stop(in6m->in6m_timer_ch);
172
173	switch (in6m->in6m_state) {
174	case MLD_REPORTPENDING:
175		mld6_start_listening(in6m);
176		break;
177	default:
178		mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
179		break;
180	}
181
182	splx(s);
183}
184
185static u_long
186mld_timerresid(struct in6_multi *in6m)
187{
188	struct timeval now, diff;
189
190	microtime(&now);
191
192	if (now.tv_sec > in6m->in6m_timer_expire.tv_sec ||
193	    (now.tv_sec == in6m->in6m_timer_expire.tv_sec &&
194	    now.tv_usec > in6m->in6m_timer_expire.tv_usec)) {
195		return (0);
196	}
197	diff = in6m->in6m_timer_expire;
198	diff.tv_sec -= now.tv_sec;
199	diff.tv_usec -= now.tv_usec;
200	if (diff.tv_usec < 0) {
201		diff.tv_sec--;
202		diff.tv_usec += 1000000;
203	}
204
205	/* return the remaining time in milliseconds */
206	return (((u_long)(diff.tv_sec * 1000000 + diff.tv_usec)) / 1000);
207}
208
209void
210mld6_start_listening(struct in6_multi *in6m)
211{
212	struct in6_addr all_in6;
213	int s = splnet();
214
215	/*
216	 * RFC2710 page 10:
217	 * The node never sends a Report or Done for the link-scope all-nodes
218	 * address.
219	 * MLD messages are never sent for multicast addresses whose scope is 0
220	 * (reserved) or 1 (node-local).
221	 */
222	all_in6 = in6addr_linklocal_allnodes;
223	if (in6_setscope(&all_in6, in6m->in6m_ifp, NULL)) {
224		/* XXX: this should not happen! */
225		in6m->in6m_timer = 0;
226		in6m->in6m_state = MLD_OTHERLISTENER;
227	}
228	if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &all_in6) ||
229	    IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
230	    IPV6_ADDR_SCOPE_LINKLOCAL) {
231		in6m->in6m_timer = 0;
232		in6m->in6m_state = MLD_OTHERLISTENER;
233	} else {
234		mld6_sendpkt(in6m, MLD_LISTENER_REPORT, NULL);
235		in6m->in6m_timer = arc4random() %
236			MLD_UNSOLICITED_REPORT_INTERVAL * hz;
237		in6m->in6m_state = MLD_IREPORTEDLAST;
238
239		mld_starttimer(in6m);
240	}
241	splx(s);
242}
243
244void
245mld6_stop_listening(struct in6_multi *in6m)
246{
247	struct in6_addr allnode, allrouter;
248
249	allnode = in6addr_linklocal_allnodes;
250	if (in6_setscope(&allnode, in6m->in6m_ifp, NULL)) {
251		/* XXX: this should not happen! */
252		return;
253	}
254	allrouter = in6addr_linklocal_allrouters;
255	if (in6_setscope(&allrouter, in6m->in6m_ifp, NULL)) {
256		/* XXX impossible */
257		return;
258	}
259	if (in6m->in6m_state == MLD_IREPORTEDLAST &&
260	    !IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &allnode) &&
261	    IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) >
262	    IPV6_ADDR_SCOPE_INTFACELOCAL) {
263		mld6_sendpkt(in6m, MLD_LISTENER_DONE, &allrouter);
264	}
265}
266
267void
268mld6_input(struct mbuf *m, int off)
269{
270	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
271	struct mld_hdr *mldh;
272	struct ifnet *ifp = m->m_pkthdr.rcvif;
273	struct in6_multi *in6m;
274	struct in6_addr mld_addr, all_in6;
275	struct in6_ifaddr *ia;
276	struct ifmultiaddr *ifma;
277	int timer;		/* timer value in the MLD query header */
278
279#ifndef PULLDOWN_TEST
280	IP6_EXTHDR_CHECK(m, off, sizeof(*mldh),);
281	mldh = (struct mld_hdr *)(mtod(m, caddr_t) + off);
282#else
283	IP6_EXTHDR_GET(mldh, struct mld_hdr *, m, off, sizeof(*mldh));
284	if (mldh == NULL) {
285		icmp6stat.icp6s_tooshort++;
286		return;
287	}
288#endif
289
290	/* source address validation */
291	ip6 = mtod(m, struct ip6_hdr *); /* in case mpullup */
292	if (!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
293		char ip6bufs[INET6_ADDRSTRLEN], ip6bufg[INET6_ADDRSTRLEN];
294		log(LOG_ERR,
295		    "mld6_input: src %s is not link-local (grp=%s)\n",
296		    ip6_sprintf(ip6bufs, &ip6->ip6_src),
297		    ip6_sprintf(ip6bufg, &mldh->mld_addr));
298		/*
299		 * spec (RFC2710) does not explicitly
300		 * specify to discard the packet from a non link-local
301		 * source address. But we believe it's expected to do so.
302		 * XXX: do we have to allow :: as source?
303		 */
304		m_freem(m);
305		return;
306	}
307
308	/*
309	 * make a copy for local work (in6_setscope() may modify the 1st arg)
310	 */
311	mld_addr = mldh->mld_addr;
312	if (in6_setscope(&mld_addr, ifp, NULL)) {
313		/* XXX: this should not happen! */
314		m_free(m);
315		return;
316	}
317
318	/*
319	 * In the MLD6 specification, there are 3 states and a flag.
320	 *
321	 * In Non-Listener state, we simply don't have a membership record.
322	 * In Delaying Listener state, our timer is running (in6m->in6m_timer)
323	 * In Idle Listener state, our timer is not running
324	 * (in6m->in6m_timer==IN6M_TIMER_UNDEF)
325	 *
326	 * The flag is in6m->in6m_state, it is set to MLD_OTHERLISTENER if
327	 * we have heard a report from another member, or MLD_IREPORTEDLAST
328	 * if we sent the last report.
329	 */
330	switch(mldh->mld_type) {
331	case MLD_LISTENER_QUERY:
332		if (ifp->if_flags & IFF_LOOPBACK)
333			break;
334
335		if (!IN6_IS_ADDR_UNSPECIFIED(&mld_addr) &&
336		    !IN6_IS_ADDR_MULTICAST(&mld_addr))
337			break;	/* print error or log stat? */
338
339		all_in6 = in6addr_linklocal_allnodes;
340		if (in6_setscope(&all_in6, ifp, NULL)) {
341			/* XXX: this should not happen! */
342			break;
343		}
344
345		/*
346		 * - Start the timers in all of our membership records
347		 *   that the query applies to for the interface on
348		 *   which the query arrived excl. those that belong
349		 *   to the "all-nodes" group (ff02::1).
350		 * - Restart any timer that is already running but has
351		 *   A value longer than the requested timeout.
352		 * - Use the value specified in the query message as
353		 *   the maximum timeout.
354		 */
355		timer = ntohs(mldh->mld_maxdelay);
356
357		IFP_TO_IA6(ifp, ia);
358		if (ia == NULL)
359			break;
360
361		/*
362		 * XXX: System timer resolution is too low to handle Max
363		 * Response Delay, so set 1 to the internal timer even if
364		 * the calculated value equals to zero when Max Response
365		 * Delay is positive.
366		 */
367		timer = ntohs(mldh->mld_maxdelay) * PR_FASTHZ / MLD_TIMER_SCALE;
368		if (timer == 0 && mldh->mld_maxdelay)
369			timer = 1;
370
371		IF_ADDR_LOCK(ifp);
372		TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
373			if (ifma->ifma_addr->sa_family != AF_INET6)
374				continue;
375			in6m = (struct in6_multi *)ifma->ifma_protospec;
376
377			if (IN6_ARE_ADDR_EQUAL(&in6m->in6m_addr, &all_in6) ||
378			    IPV6_ADDR_MC_SCOPE(&in6m->in6m_addr) <
379			    IPV6_ADDR_SCOPE_LINKLOCAL)
380				continue;
381
382			if (IN6_IS_ADDR_UNSPECIFIED(&mld_addr) ||
383			    IN6_ARE_ADDR_EQUAL(&mld_addr, &in6m->in6m_addr)) {
384				if (timer == 0) {
385					/* send a report immediately */
386					mld_stoptimer(in6m);
387					mld6_sendpkt(in6m, MLD_LISTENER_REPORT,
388						NULL);
389					in6m->in6m_timer = 0; /* reset timer */
390					in6m->in6m_state = MLD_IREPORTEDLAST;
391				}
392				else if (in6m->in6m_timer == IN6M_TIMER_UNDEF ||
393				    mld_timerresid(in6m) > (u_long)timer) {
394					in6m->in6m_timer = arc4random() %
395					    (int)((long)(timer * hz) / 1000);
396					mld_starttimer(in6m);
397				}
398			}
399		}
400		IF_ADDR_UNLOCK(ifp);
401		break;
402
403	case MLD_LISTENER_REPORT:
404		/*
405		 * For fast leave to work, we have to know that we are the
406		 * last person to send a report for this group.  Reports
407		 * can potentially get looped back if we are a multicast
408		 * router, so discard reports sourced by me.
409		 * Note that it is impossible to check IFF_LOOPBACK flag of
410		 * ifp for this purpose, since ip6_mloopback pass the physical
411		 * interface to looutput.
412		 */
413		if (m->m_flags & M_LOOP) /* XXX: grotty flag, but efficient */
414			break;
415
416		if (!IN6_IS_ADDR_MULTICAST(&mld_addr))
417			break;
418
419		/*
420		 * If we belong to the group being reported, stop
421		 * our timer for that group.
422		 */
423		IN6_LOOKUP_MULTI(mld_addr, ifp, in6m);
424		if (in6m) {
425			in6m->in6m_timer = 0; /* transit to idle state */
426			in6m->in6m_state = MLD_OTHERLISTENER; /* clear flag */
427		}
428		break;
429	default:		/* this is impossible */
430		log(LOG_ERR, "mld6_input: illegal type(%d)", mldh->mld_type);
431		break;
432	}
433
434	m_freem(m);
435}
436
437static void
438mld6_sendpkt(struct in6_multi *in6m, int type, const struct in6_addr *dst)
439{
440	struct mbuf *mh, *md;
441	struct mld_hdr *mldh;
442	struct ip6_hdr *ip6;
443	struct ip6_moptions im6o;
444	struct in6_ifaddr *ia;
445	struct ifnet *ifp = in6m->in6m_ifp;
446	struct ifnet *outif = NULL;
447
448	/*
449	 * At first, find a link local address on the outgoing interface
450	 * to use as the source address of the MLD packet.
451	 */
452	if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST))
453	    == NULL)
454		return;
455
456	/*
457	 * Allocate mbufs to store ip6 header and MLD header.
458	 * We allocate 2 mbufs and make chain in advance because
459	 * it is more convenient when inserting the hop-by-hop option later.
460	 */
461	MGETHDR(mh, M_DONTWAIT, MT_HEADER);
462	if (mh == NULL)
463		return;
464	MGET(md, M_DONTWAIT, MT_DATA);
465	if (md == NULL) {
466		m_free(mh);
467		return;
468	}
469	mh->m_next = md;
470
471	mh->m_pkthdr.rcvif = NULL;
472	mh->m_pkthdr.len = sizeof(struct ip6_hdr) + sizeof(struct mld_hdr);
473	mh->m_len = sizeof(struct ip6_hdr);
474	MH_ALIGN(mh, sizeof(struct ip6_hdr));
475
476	/* fill in the ip6 header */
477	ip6 = mtod(mh, struct ip6_hdr *);
478	ip6->ip6_flow = 0;
479	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
480	ip6->ip6_vfc |= IPV6_VERSION;
481	/* ip6_plen will be set later */
482	ip6->ip6_nxt = IPPROTO_ICMPV6;
483	/* ip6_hlim will be set by im6o.im6o_multicast_hlim */
484	ip6->ip6_src = ia->ia_addr.sin6_addr;
485	ip6->ip6_dst = dst ? *dst : in6m->in6m_addr;
486
487	/* fill in the MLD header */
488	md->m_len = sizeof(struct mld_hdr);
489	mldh = mtod(md, struct mld_hdr *);
490	mldh->mld_type = type;
491	mldh->mld_code = 0;
492	mldh->mld_cksum = 0;
493	/* XXX: we assume the function will not be called for query messages */
494	mldh->mld_maxdelay = 0;
495	mldh->mld_reserved = 0;
496	mldh->mld_addr = in6m->in6m_addr;
497	in6_clearscope(&mldh->mld_addr); /* XXX */
498	mldh->mld_cksum = in6_cksum(mh, IPPROTO_ICMPV6, sizeof(struct ip6_hdr),
499				    sizeof(struct mld_hdr));
500
501	/* construct multicast option */
502	bzero(&im6o, sizeof(im6o));
503	im6o.im6o_multicast_ifp = ifp;
504	im6o.im6o_multicast_hlim = 1;
505
506	/*
507	 * Request loopback of the report if we are acting as a multicast
508	 * router, so that the process-level routing daemon can hear it.
509	 */
510	im6o.im6o_multicast_loop = (ip6_mrouter != NULL);
511
512	/* increment output statictics */
513	icmp6stat.icp6s_outhist[type]++;
514
515	ip6_output(mh, &ip6_opts, NULL, 0, &im6o, &outif, NULL);
516	if (outif) {
517		icmp6_ifstat_inc(outif, ifs6_out_msg);
518		switch (type) {
519		case MLD_LISTENER_QUERY:
520			icmp6_ifstat_inc(outif, ifs6_out_mldquery);
521			break;
522		case MLD_LISTENER_REPORT:
523			icmp6_ifstat_inc(outif, ifs6_out_mldreport);
524			break;
525		case MLD_LISTENER_DONE:
526			icmp6_ifstat_inc(outif, ifs6_out_mlddone);
527			break;
528		}
529	}
530}
531
532/*
533 * Add an address to the list of IP6 multicast addresses for a given interface.
534 * Add source addresses to the list also, if upstream router is MLDv2 capable
535 * and the number of source is not 0.
536 */
537struct in6_multi *
538in6_addmulti(struct in6_addr *maddr6, struct ifnet *ifp,
539    int *errorp, int delay)
540{
541	struct in6_multi *in6m;
542
543	*errorp = 0;
544	in6m = NULL;
545
546	IFF_LOCKGIANT(ifp);
547	/*IN6_MULTI_LOCK();*/
548
549	IN6_LOOKUP_MULTI(*maddr6, ifp, in6m);
550	if (in6m != NULL) {
551		/*
552		 * If we already joined this group, just bump the
553		 * refcount and return it.
554		 */
555		KASSERT(in6m->in6m_refcount >= 1,
556		    ("%s: bad refcount %d", __func__, in6m->in6m_refcount));
557		++in6m->in6m_refcount;
558	} else do {
559		struct in6_multi *nin6m;
560		struct ifmultiaddr *ifma;
561		struct sockaddr_in6 sa6;
562
563		bzero(&sa6, sizeof(sa6));
564		sa6.sin6_family = AF_INET6;
565		sa6.sin6_len = sizeof(struct sockaddr_in6);
566		sa6.sin6_addr = *maddr6;
567
568		*errorp = if_addmulti(ifp, (struct sockaddr *)&sa6, &ifma);
569		if (*errorp)
570			break;
571
572		/*
573		 * If ifma->ifma_protospec is null, then if_addmulti() created
574		 * a new record.  Otherwise, bump refcount, and we are done.
575		 */
576		if (ifma->ifma_protospec != NULL) {
577			in6m = ifma->ifma_protospec;
578			++in6m->in6m_refcount;
579			break;
580		}
581
582		nin6m = malloc(sizeof(*nin6m), M_IP6MADDR, M_NOWAIT | M_ZERO);
583		if (nin6m == NULL) {
584			if_delmulti_ifma(ifma);
585			break;
586		}
587
588		nin6m->in6m_addr = *maddr6;
589		nin6m->in6m_ifp = ifp;
590		nin6m->in6m_refcount = 1;
591		nin6m->in6m_ifma = ifma;
592		ifma->ifma_protospec = nin6m;
593
594		nin6m->in6m_timer_ch = malloc(sizeof(*nin6m->in6m_timer_ch),
595		    M_IP6MADDR, M_NOWAIT);
596		if (nin6m->in6m_timer_ch == NULL) {
597			free(nin6m, M_IP6MADDR);
598			if_delmulti_ifma(ifma);
599			break;
600		}
601
602		LIST_INSERT_HEAD(&in6_multihead, nin6m, in6m_entry);
603
604		callout_init(nin6m->in6m_timer_ch, 0);
605		nin6m->in6m_timer = delay;
606		if (nin6m->in6m_timer > 0) {
607			nin6m->in6m_state = MLD_REPORTPENDING;
608			mld_starttimer(nin6m);
609		}
610
611		mld6_start_listening(nin6m);
612
613		in6m = nin6m;
614
615	} while (0);
616
617	/*IN6_MULTI_UNLOCK();*/
618	IFF_UNLOCKGIANT(ifp);
619
620	return (in6m);
621}
622
623/*
624 * Delete a multicast address record.
625 *
626 * TODO: Locking, as per netinet.
627 */
628void
629in6_delmulti(struct in6_multi *in6m)
630{
631	struct ifmultiaddr *ifma;
632
633	KASSERT(in6m->in6m_refcount >= 1, ("%s: freeing freed in6m", __func__));
634
635	if (--in6m->in6m_refcount == 0) {
636		mld_stoptimer(in6m);
637		mld6_stop_listening(in6m);
638
639		ifma = in6m->in6m_ifma;
640		KASSERT(ifma->ifma_protospec == in6m,
641		    ("%s: ifma_protospec != in6m", __func__));
642		ifma->ifma_protospec = NULL;
643
644		LIST_REMOVE(in6m, in6m_entry);
645		free(in6m->in6m_timer_ch, M_IP6MADDR);
646		free(in6m, M_IP6MADDR);
647
648		if_delmulti_ifma(ifma);
649	}
650}
651