xref: /openbmc/linux/net/ipv6/mcast.c (revision 8bd1369b)
1 /*
2  *	Multicast support for IPv6
3  *	Linux INET6 implementation
4  *
5  *	Authors:
6  *	Pedro Roque		<roque@di.fc.ul.pt>
7  *
8  *	Based on linux/ipv4/igmp.c and linux/ipv4/ip_sockglue.c
9  *
10  *	This program is free software; you can redistribute it and/or
11  *      modify it under the terms of the GNU General Public License
12  *      as published by the Free Software Foundation; either version
13  *      2 of the License, or (at your option) any later version.
14  */
15 
16 /* Changes:
17  *
18  *	yoshfuji	: fix format of router-alert option
19  *	YOSHIFUJI Hideaki @USAGI:
20  *		Fixed source address for MLD message based on
21  *		<draft-ietf-magma-mld-source-05.txt>.
22  *	YOSHIFUJI Hideaki @USAGI:
23  *		- Ignore Queries for invalid addresses.
24  *		- MLD for link-local addresses.
25  *	David L Stevens <dlstevens@us.ibm.com>:
26  *		- MLDv2 support
27  */
28 
29 #include <linux/module.h>
30 #include <linux/errno.h>
31 #include <linux/types.h>
32 #include <linux/string.h>
33 #include <linux/socket.h>
34 #include <linux/sockios.h>
35 #include <linux/jiffies.h>
36 #include <linux/times.h>
37 #include <linux/net.h>
38 #include <linux/in.h>
39 #include <linux/in6.h>
40 #include <linux/netdevice.h>
41 #include <linux/if_arp.h>
42 #include <linux/route.h>
43 #include <linux/init.h>
44 #include <linux/proc_fs.h>
45 #include <linux/seq_file.h>
46 #include <linux/slab.h>
47 #include <linux/pkt_sched.h>
48 #include <net/mld.h>
49 
50 #include <linux/netfilter.h>
51 #include <linux/netfilter_ipv6.h>
52 
53 #include <net/net_namespace.h>
54 #include <net/sock.h>
55 #include <net/snmp.h>
56 
57 #include <net/ipv6.h>
58 #include <net/protocol.h>
59 #include <net/if_inet6.h>
60 #include <net/ndisc.h>
61 #include <net/addrconf.h>
62 #include <net/ip6_route.h>
63 #include <net/inet_common.h>
64 
65 #include <net/ip6_checksum.h>
66 
67 /* Ensure that we have struct in6_addr aligned on 32bit word. */
68 static int __mld2_query_bugs[] __attribute__((__unused__)) = {
69 	BUILD_BUG_ON_ZERO(offsetof(struct mld2_query, mld2q_srcs) % 4),
70 	BUILD_BUG_ON_ZERO(offsetof(struct mld2_report, mld2r_grec) % 4),
71 	BUILD_BUG_ON_ZERO(offsetof(struct mld2_grec, grec_mca) % 4)
72 };
73 
74 static struct in6_addr mld2_all_mcr = MLD2_ALL_MCR_INIT;
75 
76 static void igmp6_join_group(struct ifmcaddr6 *ma);
77 static void igmp6_leave_group(struct ifmcaddr6 *ma);
78 static void igmp6_timer_handler(struct timer_list *t);
79 
80 static void mld_gq_timer_expire(struct timer_list *t);
81 static void mld_ifc_timer_expire(struct timer_list *t);
82 static void mld_ifc_event(struct inet6_dev *idev);
83 static void mld_add_delrec(struct inet6_dev *idev, struct ifmcaddr6 *pmc);
84 static void mld_del_delrec(struct inet6_dev *idev, struct ifmcaddr6 *pmc);
85 static void mld_clear_delrec(struct inet6_dev *idev);
86 static bool mld_in_v1_mode(const struct inet6_dev *idev);
87 static int sf_setstate(struct ifmcaddr6 *pmc);
88 static void sf_markstate(struct ifmcaddr6 *pmc);
89 static void ip6_mc_clear_src(struct ifmcaddr6 *pmc);
90 static int ip6_mc_del_src(struct inet6_dev *idev, const struct in6_addr *pmca,
91 			  int sfmode, int sfcount, const struct in6_addr *psfsrc,
92 			  int delta);
93 static int ip6_mc_add_src(struct inet6_dev *idev, const struct in6_addr *pmca,
94 			  int sfmode, int sfcount, const struct in6_addr *psfsrc,
95 			  int delta);
96 static int ip6_mc_leave_src(struct sock *sk, struct ipv6_mc_socklist *iml,
97 			    struct inet6_dev *idev);
98 static int __ipv6_dev_mc_inc(struct net_device *dev,
99 			     const struct in6_addr *addr, unsigned int mode);
100 
101 #define MLD_QRV_DEFAULT		2
102 /* RFC3810, 9.2. Query Interval */
103 #define MLD_QI_DEFAULT		(125 * HZ)
104 /* RFC3810, 9.3. Query Response Interval */
105 #define MLD_QRI_DEFAULT		(10 * HZ)
106 
107 /* RFC3810, 8.1 Query Version Distinctions */
108 #define MLD_V1_QUERY_LEN	24
109 #define MLD_V2_QUERY_LEN_MIN	28
110 
111 #define IPV6_MLD_MAX_MSF	64
112 
113 int sysctl_mld_max_msf __read_mostly = IPV6_MLD_MAX_MSF;
114 int sysctl_mld_qrv __read_mostly = MLD_QRV_DEFAULT;
115 
116 /*
117  *	socket join on multicast group
118  */
119 
120 #define for_each_pmc_rcu(np, pmc)				\
121 	for (pmc = rcu_dereference(np->ipv6_mc_list);		\
122 	     pmc != NULL;					\
123 	     pmc = rcu_dereference(pmc->next))
124 
125 static int unsolicited_report_interval(struct inet6_dev *idev)
126 {
127 	int iv;
128 
129 	if (mld_in_v1_mode(idev))
130 		iv = idev->cnf.mldv1_unsolicited_report_interval;
131 	else
132 		iv = idev->cnf.mldv2_unsolicited_report_interval;
133 
134 	return iv > 0 ? iv : 1;
135 }
136 
137 static int __ipv6_sock_mc_join(struct sock *sk, int ifindex,
138 			       const struct in6_addr *addr, unsigned int mode)
139 {
140 	struct net_device *dev = NULL;
141 	struct ipv6_mc_socklist *mc_lst;
142 	struct ipv6_pinfo *np = inet6_sk(sk);
143 	struct net *net = sock_net(sk);
144 	int err;
145 
146 	ASSERT_RTNL();
147 
148 	if (!ipv6_addr_is_multicast(addr))
149 		return -EINVAL;
150 
151 	rcu_read_lock();
152 	for_each_pmc_rcu(np, mc_lst) {
153 		if ((ifindex == 0 || mc_lst->ifindex == ifindex) &&
154 		    ipv6_addr_equal(&mc_lst->addr, addr)) {
155 			rcu_read_unlock();
156 			return -EADDRINUSE;
157 		}
158 	}
159 	rcu_read_unlock();
160 
161 	mc_lst = sock_kmalloc(sk, sizeof(struct ipv6_mc_socklist), GFP_KERNEL);
162 
163 	if (!mc_lst)
164 		return -ENOMEM;
165 
166 	mc_lst->next = NULL;
167 	mc_lst->addr = *addr;
168 
169 	if (ifindex == 0) {
170 		struct rt6_info *rt;
171 		rt = rt6_lookup(net, addr, NULL, 0, NULL, 0);
172 		if (rt) {
173 			dev = rt->dst.dev;
174 			ip6_rt_put(rt);
175 		}
176 	} else
177 		dev = __dev_get_by_index(net, ifindex);
178 
179 	if (!dev) {
180 		sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
181 		return -ENODEV;
182 	}
183 
184 	mc_lst->ifindex = dev->ifindex;
185 	mc_lst->sfmode = mode;
186 	rwlock_init(&mc_lst->sflock);
187 	mc_lst->sflist = NULL;
188 
189 	/*
190 	 *	now add/increase the group membership on the device
191 	 */
192 
193 	err = __ipv6_dev_mc_inc(dev, addr, mode);
194 
195 	if (err) {
196 		sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
197 		return err;
198 	}
199 
200 	mc_lst->next = np->ipv6_mc_list;
201 	rcu_assign_pointer(np->ipv6_mc_list, mc_lst);
202 
203 	return 0;
204 }
205 
206 int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
207 {
208 	return __ipv6_sock_mc_join(sk, ifindex, addr, MCAST_EXCLUDE);
209 }
210 EXPORT_SYMBOL(ipv6_sock_mc_join);
211 
212 int ipv6_sock_mc_join_ssm(struct sock *sk, int ifindex,
213 			  const struct in6_addr *addr, unsigned int mode)
214 {
215 	return __ipv6_sock_mc_join(sk, ifindex, addr, mode);
216 }
217 
218 /*
219  *	socket leave on multicast group
220  */
221 int ipv6_sock_mc_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
222 {
223 	struct ipv6_pinfo *np = inet6_sk(sk);
224 	struct ipv6_mc_socklist *mc_lst;
225 	struct ipv6_mc_socklist __rcu **lnk;
226 	struct net *net = sock_net(sk);
227 
228 	ASSERT_RTNL();
229 
230 	if (!ipv6_addr_is_multicast(addr))
231 		return -EINVAL;
232 
233 	for (lnk = &np->ipv6_mc_list;
234 	     (mc_lst = rtnl_dereference(*lnk)) != NULL;
235 	      lnk = &mc_lst->next) {
236 		if ((ifindex == 0 || mc_lst->ifindex == ifindex) &&
237 		    ipv6_addr_equal(&mc_lst->addr, addr)) {
238 			struct net_device *dev;
239 
240 			*lnk = mc_lst->next;
241 
242 			dev = __dev_get_by_index(net, mc_lst->ifindex);
243 			if (dev) {
244 				struct inet6_dev *idev = __in6_dev_get(dev);
245 
246 				(void) ip6_mc_leave_src(sk, mc_lst, idev);
247 				if (idev)
248 					__ipv6_dev_mc_dec(idev, &mc_lst->addr);
249 			} else
250 				(void) ip6_mc_leave_src(sk, mc_lst, NULL);
251 
252 			atomic_sub(sizeof(*mc_lst), &sk->sk_omem_alloc);
253 			kfree_rcu(mc_lst, rcu);
254 			return 0;
255 		}
256 	}
257 
258 	return -EADDRNOTAVAIL;
259 }
260 EXPORT_SYMBOL(ipv6_sock_mc_drop);
261 
262 /* called with rcu_read_lock() */
263 static struct inet6_dev *ip6_mc_find_dev_rcu(struct net *net,
264 					     const struct in6_addr *group,
265 					     int ifindex)
266 {
267 	struct net_device *dev = NULL;
268 	struct inet6_dev *idev = NULL;
269 
270 	if (ifindex == 0) {
271 		struct rt6_info *rt = rt6_lookup(net, group, NULL, 0, NULL, 0);
272 
273 		if (rt) {
274 			dev = rt->dst.dev;
275 			ip6_rt_put(rt);
276 		}
277 	} else
278 		dev = dev_get_by_index_rcu(net, ifindex);
279 
280 	if (!dev)
281 		return NULL;
282 	idev = __in6_dev_get(dev);
283 	if (!idev)
284 		return NULL;
285 	read_lock_bh(&idev->lock);
286 	if (idev->dead) {
287 		read_unlock_bh(&idev->lock);
288 		return NULL;
289 	}
290 	return idev;
291 }
292 
293 void __ipv6_sock_mc_close(struct sock *sk)
294 {
295 	struct ipv6_pinfo *np = inet6_sk(sk);
296 	struct ipv6_mc_socklist *mc_lst;
297 	struct net *net = sock_net(sk);
298 
299 	ASSERT_RTNL();
300 
301 	while ((mc_lst = rtnl_dereference(np->ipv6_mc_list)) != NULL) {
302 		struct net_device *dev;
303 
304 		np->ipv6_mc_list = mc_lst->next;
305 
306 		dev = __dev_get_by_index(net, mc_lst->ifindex);
307 		if (dev) {
308 			struct inet6_dev *idev = __in6_dev_get(dev);
309 
310 			(void) ip6_mc_leave_src(sk, mc_lst, idev);
311 			if (idev)
312 				__ipv6_dev_mc_dec(idev, &mc_lst->addr);
313 		} else
314 			(void) ip6_mc_leave_src(sk, mc_lst, NULL);
315 
316 		atomic_sub(sizeof(*mc_lst), &sk->sk_omem_alloc);
317 		kfree_rcu(mc_lst, rcu);
318 	}
319 }
320 
321 void ipv6_sock_mc_close(struct sock *sk)
322 {
323 	struct ipv6_pinfo *np = inet6_sk(sk);
324 
325 	if (!rcu_access_pointer(np->ipv6_mc_list))
326 		return;
327 	rtnl_lock();
328 	__ipv6_sock_mc_close(sk);
329 	rtnl_unlock();
330 }
331 
332 int ip6_mc_source(int add, int omode, struct sock *sk,
333 	struct group_source_req *pgsr)
334 {
335 	struct in6_addr *source, *group;
336 	struct ipv6_mc_socklist *pmc;
337 	struct inet6_dev *idev;
338 	struct ipv6_pinfo *inet6 = inet6_sk(sk);
339 	struct ip6_sf_socklist *psl;
340 	struct net *net = sock_net(sk);
341 	int i, j, rv;
342 	int leavegroup = 0;
343 	int pmclocked = 0;
344 	int err;
345 
346 	source = &((struct sockaddr_in6 *)&pgsr->gsr_source)->sin6_addr;
347 	group = &((struct sockaddr_in6 *)&pgsr->gsr_group)->sin6_addr;
348 
349 	if (!ipv6_addr_is_multicast(group))
350 		return -EINVAL;
351 
352 	rcu_read_lock();
353 	idev = ip6_mc_find_dev_rcu(net, group, pgsr->gsr_interface);
354 	if (!idev) {
355 		rcu_read_unlock();
356 		return -ENODEV;
357 	}
358 
359 	err = -EADDRNOTAVAIL;
360 
361 	for_each_pmc_rcu(inet6, pmc) {
362 		if (pgsr->gsr_interface && pmc->ifindex != pgsr->gsr_interface)
363 			continue;
364 		if (ipv6_addr_equal(&pmc->addr, group))
365 			break;
366 	}
367 	if (!pmc) {		/* must have a prior join */
368 		err = -EINVAL;
369 		goto done;
370 	}
371 	/* if a source filter was set, must be the same mode as before */
372 	if (pmc->sflist) {
373 		if (pmc->sfmode != omode) {
374 			err = -EINVAL;
375 			goto done;
376 		}
377 	} else if (pmc->sfmode != omode) {
378 		/* allow mode switches for empty-set filters */
379 		ip6_mc_add_src(idev, group, omode, 0, NULL, 0);
380 		ip6_mc_del_src(idev, group, pmc->sfmode, 0, NULL, 0);
381 		pmc->sfmode = omode;
382 	}
383 
384 	write_lock(&pmc->sflock);
385 	pmclocked = 1;
386 
387 	psl = pmc->sflist;
388 	if (!add) {
389 		if (!psl)
390 			goto done;	/* err = -EADDRNOTAVAIL */
391 		rv = !0;
392 		for (i = 0; i < psl->sl_count; i++) {
393 			rv = !ipv6_addr_equal(&psl->sl_addr[i], source);
394 			if (rv == 0)
395 				break;
396 		}
397 		if (rv)		/* source not found */
398 			goto done;	/* err = -EADDRNOTAVAIL */
399 
400 		/* special case - (INCLUDE, empty) == LEAVE_GROUP */
401 		if (psl->sl_count == 1 && omode == MCAST_INCLUDE) {
402 			leavegroup = 1;
403 			goto done;
404 		}
405 
406 		/* update the interface filter */
407 		ip6_mc_del_src(idev, group, omode, 1, source, 1);
408 
409 		for (j = i+1; j < psl->sl_count; j++)
410 			psl->sl_addr[j-1] = psl->sl_addr[j];
411 		psl->sl_count--;
412 		err = 0;
413 		goto done;
414 	}
415 	/* else, add a new source to the filter */
416 
417 	if (psl && psl->sl_count >= sysctl_mld_max_msf) {
418 		err = -ENOBUFS;
419 		goto done;
420 	}
421 	if (!psl || psl->sl_count == psl->sl_max) {
422 		struct ip6_sf_socklist *newpsl;
423 		int count = IP6_SFBLOCK;
424 
425 		if (psl)
426 			count += psl->sl_max;
427 		newpsl = sock_kmalloc(sk, IP6_SFLSIZE(count), GFP_ATOMIC);
428 		if (!newpsl) {
429 			err = -ENOBUFS;
430 			goto done;
431 		}
432 		newpsl->sl_max = count;
433 		newpsl->sl_count = count - IP6_SFBLOCK;
434 		if (psl) {
435 			for (i = 0; i < psl->sl_count; i++)
436 				newpsl->sl_addr[i] = psl->sl_addr[i];
437 			sock_kfree_s(sk, psl, IP6_SFLSIZE(psl->sl_max));
438 		}
439 		pmc->sflist = psl = newpsl;
440 	}
441 	rv = 1;	/* > 0 for insert logic below if sl_count is 0 */
442 	for (i = 0; i < psl->sl_count; i++) {
443 		rv = !ipv6_addr_equal(&psl->sl_addr[i], source);
444 		if (rv == 0) /* There is an error in the address. */
445 			goto done;
446 	}
447 	for (j = psl->sl_count-1; j >= i; j--)
448 		psl->sl_addr[j+1] = psl->sl_addr[j];
449 	psl->sl_addr[i] = *source;
450 	psl->sl_count++;
451 	err = 0;
452 	/* update the interface list */
453 	ip6_mc_add_src(idev, group, omode, 1, source, 1);
454 done:
455 	if (pmclocked)
456 		write_unlock(&pmc->sflock);
457 	read_unlock_bh(&idev->lock);
458 	rcu_read_unlock();
459 	if (leavegroup)
460 		err = ipv6_sock_mc_drop(sk, pgsr->gsr_interface, group);
461 	return err;
462 }
463 
464 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf)
465 {
466 	const struct in6_addr *group;
467 	struct ipv6_mc_socklist *pmc;
468 	struct inet6_dev *idev;
469 	struct ipv6_pinfo *inet6 = inet6_sk(sk);
470 	struct ip6_sf_socklist *newpsl, *psl;
471 	struct net *net = sock_net(sk);
472 	int leavegroup = 0;
473 	int i, err;
474 
475 	group = &((struct sockaddr_in6 *)&gsf->gf_group)->sin6_addr;
476 
477 	if (!ipv6_addr_is_multicast(group))
478 		return -EINVAL;
479 	if (gsf->gf_fmode != MCAST_INCLUDE &&
480 	    gsf->gf_fmode != MCAST_EXCLUDE)
481 		return -EINVAL;
482 
483 	rcu_read_lock();
484 	idev = ip6_mc_find_dev_rcu(net, group, gsf->gf_interface);
485 
486 	if (!idev) {
487 		rcu_read_unlock();
488 		return -ENODEV;
489 	}
490 
491 	err = 0;
492 
493 	if (gsf->gf_fmode == MCAST_INCLUDE && gsf->gf_numsrc == 0) {
494 		leavegroup = 1;
495 		goto done;
496 	}
497 
498 	for_each_pmc_rcu(inet6, pmc) {
499 		if (pmc->ifindex != gsf->gf_interface)
500 			continue;
501 		if (ipv6_addr_equal(&pmc->addr, group))
502 			break;
503 	}
504 	if (!pmc) {		/* must have a prior join */
505 		err = -EINVAL;
506 		goto done;
507 	}
508 	if (gsf->gf_numsrc) {
509 		newpsl = sock_kmalloc(sk, IP6_SFLSIZE(gsf->gf_numsrc),
510 							  GFP_ATOMIC);
511 		if (!newpsl) {
512 			err = -ENOBUFS;
513 			goto done;
514 		}
515 		newpsl->sl_max = newpsl->sl_count = gsf->gf_numsrc;
516 		for (i = 0; i < newpsl->sl_count; ++i) {
517 			struct sockaddr_in6 *psin6;
518 
519 			psin6 = (struct sockaddr_in6 *)&gsf->gf_slist[i];
520 			newpsl->sl_addr[i] = psin6->sin6_addr;
521 		}
522 		err = ip6_mc_add_src(idev, group, gsf->gf_fmode,
523 			newpsl->sl_count, newpsl->sl_addr, 0);
524 		if (err) {
525 			sock_kfree_s(sk, newpsl, IP6_SFLSIZE(newpsl->sl_max));
526 			goto done;
527 		}
528 	} else {
529 		newpsl = NULL;
530 		(void) ip6_mc_add_src(idev, group, gsf->gf_fmode, 0, NULL, 0);
531 	}
532 
533 	write_lock(&pmc->sflock);
534 	psl = pmc->sflist;
535 	if (psl) {
536 		(void) ip6_mc_del_src(idev, group, pmc->sfmode,
537 			psl->sl_count, psl->sl_addr, 0);
538 		sock_kfree_s(sk, psl, IP6_SFLSIZE(psl->sl_max));
539 	} else
540 		(void) ip6_mc_del_src(idev, group, pmc->sfmode, 0, NULL, 0);
541 	pmc->sflist = newpsl;
542 	pmc->sfmode = gsf->gf_fmode;
543 	write_unlock(&pmc->sflock);
544 	err = 0;
545 done:
546 	read_unlock_bh(&idev->lock);
547 	rcu_read_unlock();
548 	if (leavegroup)
549 		err = ipv6_sock_mc_drop(sk, gsf->gf_interface, group);
550 	return err;
551 }
552 
553 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
554 	struct group_filter __user *optval, int __user *optlen)
555 {
556 	int err, i, count, copycount;
557 	const struct in6_addr *group;
558 	struct ipv6_mc_socklist *pmc;
559 	struct inet6_dev *idev;
560 	struct ipv6_pinfo *inet6 = inet6_sk(sk);
561 	struct ip6_sf_socklist *psl;
562 	struct net *net = sock_net(sk);
563 
564 	group = &((struct sockaddr_in6 *)&gsf->gf_group)->sin6_addr;
565 
566 	if (!ipv6_addr_is_multicast(group))
567 		return -EINVAL;
568 
569 	rcu_read_lock();
570 	idev = ip6_mc_find_dev_rcu(net, group, gsf->gf_interface);
571 
572 	if (!idev) {
573 		rcu_read_unlock();
574 		return -ENODEV;
575 	}
576 
577 	err = -EADDRNOTAVAIL;
578 	/* changes to the ipv6_mc_list require the socket lock and
579 	 * rtnl lock. We have the socket lock and rcu read lock,
580 	 * so reading the list is safe.
581 	 */
582 
583 	for_each_pmc_rcu(inet6, pmc) {
584 		if (pmc->ifindex != gsf->gf_interface)
585 			continue;
586 		if (ipv6_addr_equal(group, &pmc->addr))
587 			break;
588 	}
589 	if (!pmc)		/* must have a prior join */
590 		goto done;
591 	gsf->gf_fmode = pmc->sfmode;
592 	psl = pmc->sflist;
593 	count = psl ? psl->sl_count : 0;
594 	read_unlock_bh(&idev->lock);
595 	rcu_read_unlock();
596 
597 	copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
598 	gsf->gf_numsrc = count;
599 	if (put_user(GROUP_FILTER_SIZE(copycount), optlen) ||
600 	    copy_to_user(optval, gsf, GROUP_FILTER_SIZE(0))) {
601 		return -EFAULT;
602 	}
603 	/* changes to psl require the socket lock, and a write lock
604 	 * on pmc->sflock. We have the socket lock so reading here is safe.
605 	 */
606 	for (i = 0; i < copycount; i++) {
607 		struct sockaddr_in6 *psin6;
608 		struct sockaddr_storage ss;
609 
610 		psin6 = (struct sockaddr_in6 *)&ss;
611 		memset(&ss, 0, sizeof(ss));
612 		psin6->sin6_family = AF_INET6;
613 		psin6->sin6_addr = psl->sl_addr[i];
614 		if (copy_to_user(&optval->gf_slist[i], &ss, sizeof(ss)))
615 			return -EFAULT;
616 	}
617 	return 0;
618 done:
619 	read_unlock_bh(&idev->lock);
620 	rcu_read_unlock();
621 	return err;
622 }
623 
624 bool inet6_mc_check(struct sock *sk, const struct in6_addr *mc_addr,
625 		    const struct in6_addr *src_addr)
626 {
627 	struct ipv6_pinfo *np = inet6_sk(sk);
628 	struct ipv6_mc_socklist *mc;
629 	struct ip6_sf_socklist *psl;
630 	bool rv = true;
631 
632 	rcu_read_lock();
633 	for_each_pmc_rcu(np, mc) {
634 		if (ipv6_addr_equal(&mc->addr, mc_addr))
635 			break;
636 	}
637 	if (!mc) {
638 		rcu_read_unlock();
639 		return true;
640 	}
641 	read_lock(&mc->sflock);
642 	psl = mc->sflist;
643 	if (!psl) {
644 		rv = mc->sfmode == MCAST_EXCLUDE;
645 	} else {
646 		int i;
647 
648 		for (i = 0; i < psl->sl_count; i++) {
649 			if (ipv6_addr_equal(&psl->sl_addr[i], src_addr))
650 				break;
651 		}
652 		if (mc->sfmode == MCAST_INCLUDE && i >= psl->sl_count)
653 			rv = false;
654 		if (mc->sfmode == MCAST_EXCLUDE && i < psl->sl_count)
655 			rv = false;
656 	}
657 	read_unlock(&mc->sflock);
658 	rcu_read_unlock();
659 
660 	return rv;
661 }
662 
663 static void igmp6_group_added(struct ifmcaddr6 *mc, unsigned int mode)
664 {
665 	struct net_device *dev = mc->idev->dev;
666 	char buf[MAX_ADDR_LEN];
667 
668 	if (IPV6_ADDR_MC_SCOPE(&mc->mca_addr) <
669 	    IPV6_ADDR_SCOPE_LINKLOCAL)
670 		return;
671 
672 	spin_lock_bh(&mc->mca_lock);
673 	if (!(mc->mca_flags&MAF_LOADED)) {
674 		mc->mca_flags |= MAF_LOADED;
675 		if (ndisc_mc_map(&mc->mca_addr, buf, dev, 0) == 0)
676 			dev_mc_add(dev, buf);
677 	}
678 	spin_unlock_bh(&mc->mca_lock);
679 
680 	if (!(dev->flags & IFF_UP) || (mc->mca_flags & MAF_NOREPORT))
681 		return;
682 
683 	if (mld_in_v1_mode(mc->idev)) {
684 		igmp6_join_group(mc);
685 		return;
686 	}
687 	/* else v2 */
688 
689 	/* Based on RFC3810 6.1, for newly added INCLUDE SSM, we
690 	 * should not send filter-mode change record as the mode
691 	 * should be from IN() to IN(A).
692 	 */
693 	if (mode == MCAST_EXCLUDE)
694 		mc->mca_crcount = mc->idev->mc_qrv;
695 
696 	mld_ifc_event(mc->idev);
697 }
698 
699 static void igmp6_group_dropped(struct ifmcaddr6 *mc)
700 {
701 	struct net_device *dev = mc->idev->dev;
702 	char buf[MAX_ADDR_LEN];
703 
704 	if (IPV6_ADDR_MC_SCOPE(&mc->mca_addr) <
705 	    IPV6_ADDR_SCOPE_LINKLOCAL)
706 		return;
707 
708 	spin_lock_bh(&mc->mca_lock);
709 	if (mc->mca_flags&MAF_LOADED) {
710 		mc->mca_flags &= ~MAF_LOADED;
711 		if (ndisc_mc_map(&mc->mca_addr, buf, dev, 0) == 0)
712 			dev_mc_del(dev, buf);
713 	}
714 
715 	spin_unlock_bh(&mc->mca_lock);
716 	if (mc->mca_flags & MAF_NOREPORT)
717 		return;
718 
719 	if (!mc->idev->dead)
720 		igmp6_leave_group(mc);
721 
722 	spin_lock_bh(&mc->mca_lock);
723 	if (del_timer(&mc->mca_timer))
724 		refcount_dec(&mc->mca_refcnt);
725 	spin_unlock_bh(&mc->mca_lock);
726 }
727 
728 /*
729  * deleted ifmcaddr6 manipulation
730  */
731 static void mld_add_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im)
732 {
733 	struct ifmcaddr6 *pmc;
734 
735 	/* this is an "ifmcaddr6" for convenience; only the fields below
736 	 * are actually used. In particular, the refcnt and users are not
737 	 * used for management of the delete list. Using the same structure
738 	 * for deleted items allows change reports to use common code with
739 	 * non-deleted or query-response MCA's.
740 	 */
741 	pmc = kzalloc(sizeof(*pmc), GFP_ATOMIC);
742 	if (!pmc)
743 		return;
744 
745 	spin_lock_bh(&im->mca_lock);
746 	spin_lock_init(&pmc->mca_lock);
747 	pmc->idev = im->idev;
748 	in6_dev_hold(idev);
749 	pmc->mca_addr = im->mca_addr;
750 	pmc->mca_crcount = idev->mc_qrv;
751 	pmc->mca_sfmode = im->mca_sfmode;
752 	if (pmc->mca_sfmode == MCAST_INCLUDE) {
753 		struct ip6_sf_list *psf;
754 
755 		pmc->mca_tomb = im->mca_tomb;
756 		pmc->mca_sources = im->mca_sources;
757 		im->mca_tomb = im->mca_sources = NULL;
758 		for (psf = pmc->mca_sources; psf; psf = psf->sf_next)
759 			psf->sf_crcount = pmc->mca_crcount;
760 	}
761 	spin_unlock_bh(&im->mca_lock);
762 
763 	spin_lock_bh(&idev->mc_lock);
764 	pmc->next = idev->mc_tomb;
765 	idev->mc_tomb = pmc;
766 	spin_unlock_bh(&idev->mc_lock);
767 }
768 
769 static void mld_del_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im)
770 {
771 	struct ifmcaddr6 *pmc, *pmc_prev;
772 	struct ip6_sf_list *psf;
773 	struct in6_addr *pmca = &im->mca_addr;
774 
775 	spin_lock_bh(&idev->mc_lock);
776 	pmc_prev = NULL;
777 	for (pmc = idev->mc_tomb; pmc; pmc = pmc->next) {
778 		if (ipv6_addr_equal(&pmc->mca_addr, pmca))
779 			break;
780 		pmc_prev = pmc;
781 	}
782 	if (pmc) {
783 		if (pmc_prev)
784 			pmc_prev->next = pmc->next;
785 		else
786 			idev->mc_tomb = pmc->next;
787 	}
788 	spin_unlock_bh(&idev->mc_lock);
789 
790 	spin_lock_bh(&im->mca_lock);
791 	if (pmc) {
792 		im->idev = pmc->idev;
793 		im->mca_sfmode = pmc->mca_sfmode;
794 		if (pmc->mca_sfmode == MCAST_INCLUDE) {
795 			im->mca_tomb = pmc->mca_tomb;
796 			im->mca_sources = pmc->mca_sources;
797 			for (psf = im->mca_sources; psf; psf = psf->sf_next)
798 				psf->sf_crcount = idev->mc_qrv;
799 		} else {
800 			im->mca_crcount = idev->mc_qrv;
801 		}
802 		in6_dev_put(pmc->idev);
803 		kfree(pmc);
804 	}
805 	spin_unlock_bh(&im->mca_lock);
806 }
807 
808 static void mld_clear_delrec(struct inet6_dev *idev)
809 {
810 	struct ifmcaddr6 *pmc, *nextpmc;
811 
812 	spin_lock_bh(&idev->mc_lock);
813 	pmc = idev->mc_tomb;
814 	idev->mc_tomb = NULL;
815 	spin_unlock_bh(&idev->mc_lock);
816 
817 	for (; pmc; pmc = nextpmc) {
818 		nextpmc = pmc->next;
819 		ip6_mc_clear_src(pmc);
820 		in6_dev_put(pmc->idev);
821 		kfree(pmc);
822 	}
823 
824 	/* clear dead sources, too */
825 	read_lock_bh(&idev->lock);
826 	for (pmc = idev->mc_list; pmc; pmc = pmc->next) {
827 		struct ip6_sf_list *psf, *psf_next;
828 
829 		spin_lock_bh(&pmc->mca_lock);
830 		psf = pmc->mca_tomb;
831 		pmc->mca_tomb = NULL;
832 		spin_unlock_bh(&pmc->mca_lock);
833 		for (; psf; psf = psf_next) {
834 			psf_next = psf->sf_next;
835 			kfree(psf);
836 		}
837 	}
838 	read_unlock_bh(&idev->lock);
839 }
840 
841 static void mca_get(struct ifmcaddr6 *mc)
842 {
843 	refcount_inc(&mc->mca_refcnt);
844 }
845 
846 static void ma_put(struct ifmcaddr6 *mc)
847 {
848 	if (refcount_dec_and_test(&mc->mca_refcnt)) {
849 		in6_dev_put(mc->idev);
850 		kfree(mc);
851 	}
852 }
853 
854 static struct ifmcaddr6 *mca_alloc(struct inet6_dev *idev,
855 				   const struct in6_addr *addr,
856 				   unsigned int mode)
857 {
858 	struct ifmcaddr6 *mc;
859 
860 	mc = kzalloc(sizeof(*mc), GFP_ATOMIC);
861 	if (!mc)
862 		return NULL;
863 
864 	timer_setup(&mc->mca_timer, igmp6_timer_handler, 0);
865 
866 	mc->mca_addr = *addr;
867 	mc->idev = idev; /* reference taken by caller */
868 	mc->mca_users = 1;
869 	/* mca_stamp should be updated upon changes */
870 	mc->mca_cstamp = mc->mca_tstamp = jiffies;
871 	refcount_set(&mc->mca_refcnt, 1);
872 	spin_lock_init(&mc->mca_lock);
873 
874 	mc->mca_sfmode = mode;
875 	mc->mca_sfcount[mode] = 1;
876 
877 	if (ipv6_addr_is_ll_all_nodes(&mc->mca_addr) ||
878 	    IPV6_ADDR_MC_SCOPE(&mc->mca_addr) < IPV6_ADDR_SCOPE_LINKLOCAL)
879 		mc->mca_flags |= MAF_NOREPORT;
880 
881 	return mc;
882 }
883 
884 /*
885  *	device multicast group inc (add if not found)
886  */
887 static int __ipv6_dev_mc_inc(struct net_device *dev,
888 			     const struct in6_addr *addr, unsigned int mode)
889 {
890 	struct ifmcaddr6 *mc;
891 	struct inet6_dev *idev;
892 
893 	ASSERT_RTNL();
894 
895 	/* we need to take a reference on idev */
896 	idev = in6_dev_get(dev);
897 
898 	if (!idev)
899 		return -EINVAL;
900 
901 	write_lock_bh(&idev->lock);
902 	if (idev->dead) {
903 		write_unlock_bh(&idev->lock);
904 		in6_dev_put(idev);
905 		return -ENODEV;
906 	}
907 
908 	for (mc = idev->mc_list; mc; mc = mc->next) {
909 		if (ipv6_addr_equal(&mc->mca_addr, addr)) {
910 			mc->mca_users++;
911 			write_unlock_bh(&idev->lock);
912 			ip6_mc_add_src(idev, &mc->mca_addr, mode, 0, NULL, 0);
913 			in6_dev_put(idev);
914 			return 0;
915 		}
916 	}
917 
918 	mc = mca_alloc(idev, addr, mode);
919 	if (!mc) {
920 		write_unlock_bh(&idev->lock);
921 		in6_dev_put(idev);
922 		return -ENOMEM;
923 	}
924 
925 	mc->next = idev->mc_list;
926 	idev->mc_list = mc;
927 
928 	/* Hold this for the code below before we unlock,
929 	 * it is already exposed via idev->mc_list.
930 	 */
931 	mca_get(mc);
932 	write_unlock_bh(&idev->lock);
933 
934 	mld_del_delrec(idev, mc);
935 	igmp6_group_added(mc, mode);
936 	ma_put(mc);
937 	return 0;
938 }
939 
940 int ipv6_dev_mc_inc(struct net_device *dev, const struct in6_addr *addr)
941 {
942 	return __ipv6_dev_mc_inc(dev, addr, MCAST_EXCLUDE);
943 }
944 
945 /*
946  *	device multicast group del
947  */
948 int __ipv6_dev_mc_dec(struct inet6_dev *idev, const struct in6_addr *addr)
949 {
950 	struct ifmcaddr6 *ma, **map;
951 
952 	ASSERT_RTNL();
953 
954 	write_lock_bh(&idev->lock);
955 	for (map = &idev->mc_list; (ma = *map) != NULL; map = &ma->next) {
956 		if (ipv6_addr_equal(&ma->mca_addr, addr)) {
957 			if (--ma->mca_users == 0) {
958 				*map = ma->next;
959 				write_unlock_bh(&idev->lock);
960 
961 				igmp6_group_dropped(ma);
962 				ip6_mc_clear_src(ma);
963 
964 				ma_put(ma);
965 				return 0;
966 			}
967 			write_unlock_bh(&idev->lock);
968 			return 0;
969 		}
970 	}
971 	write_unlock_bh(&idev->lock);
972 
973 	return -ENOENT;
974 }
975 
976 int ipv6_dev_mc_dec(struct net_device *dev, const struct in6_addr *addr)
977 {
978 	struct inet6_dev *idev;
979 	int err;
980 
981 	ASSERT_RTNL();
982 
983 	idev = __in6_dev_get(dev);
984 	if (!idev)
985 		err = -ENODEV;
986 	else
987 		err = __ipv6_dev_mc_dec(idev, addr);
988 
989 	return err;
990 }
991 
992 /*
993  *	check if the interface/address pair is valid
994  */
995 bool ipv6_chk_mcast_addr(struct net_device *dev, const struct in6_addr *group,
996 			 const struct in6_addr *src_addr)
997 {
998 	struct inet6_dev *idev;
999 	struct ifmcaddr6 *mc;
1000 	bool rv = false;
1001 
1002 	rcu_read_lock();
1003 	idev = __in6_dev_get(dev);
1004 	if (idev) {
1005 		read_lock_bh(&idev->lock);
1006 		for (mc = idev->mc_list; mc; mc = mc->next) {
1007 			if (ipv6_addr_equal(&mc->mca_addr, group))
1008 				break;
1009 		}
1010 		if (mc) {
1011 			if (src_addr && !ipv6_addr_any(src_addr)) {
1012 				struct ip6_sf_list *psf;
1013 
1014 				spin_lock_bh(&mc->mca_lock);
1015 				for (psf = mc->mca_sources; psf; psf = psf->sf_next) {
1016 					if (ipv6_addr_equal(&psf->sf_addr, src_addr))
1017 						break;
1018 				}
1019 				if (psf)
1020 					rv = psf->sf_count[MCAST_INCLUDE] ||
1021 						psf->sf_count[MCAST_EXCLUDE] !=
1022 						mc->mca_sfcount[MCAST_EXCLUDE];
1023 				else
1024 					rv = mc->mca_sfcount[MCAST_EXCLUDE] != 0;
1025 				spin_unlock_bh(&mc->mca_lock);
1026 			} else
1027 				rv = true; /* don't filter unspecified source */
1028 		}
1029 		read_unlock_bh(&idev->lock);
1030 	}
1031 	rcu_read_unlock();
1032 	return rv;
1033 }
1034 
1035 static void mld_gq_start_timer(struct inet6_dev *idev)
1036 {
1037 	unsigned long tv = prandom_u32() % idev->mc_maxdelay;
1038 
1039 	idev->mc_gq_running = 1;
1040 	if (!mod_timer(&idev->mc_gq_timer, jiffies+tv+2))
1041 		in6_dev_hold(idev);
1042 }
1043 
1044 static void mld_gq_stop_timer(struct inet6_dev *idev)
1045 {
1046 	idev->mc_gq_running = 0;
1047 	if (del_timer(&idev->mc_gq_timer))
1048 		__in6_dev_put(idev);
1049 }
1050 
1051 static void mld_ifc_start_timer(struct inet6_dev *idev, unsigned long delay)
1052 {
1053 	unsigned long tv = prandom_u32() % delay;
1054 
1055 	if (!mod_timer(&idev->mc_ifc_timer, jiffies+tv+2))
1056 		in6_dev_hold(idev);
1057 }
1058 
1059 static void mld_ifc_stop_timer(struct inet6_dev *idev)
1060 {
1061 	idev->mc_ifc_count = 0;
1062 	if (del_timer(&idev->mc_ifc_timer))
1063 		__in6_dev_put(idev);
1064 }
1065 
1066 static void mld_dad_start_timer(struct inet6_dev *idev, unsigned long delay)
1067 {
1068 	unsigned long tv = prandom_u32() % delay;
1069 
1070 	if (!mod_timer(&idev->mc_dad_timer, jiffies+tv+2))
1071 		in6_dev_hold(idev);
1072 }
1073 
1074 static void mld_dad_stop_timer(struct inet6_dev *idev)
1075 {
1076 	if (del_timer(&idev->mc_dad_timer))
1077 		__in6_dev_put(idev);
1078 }
1079 
1080 /*
1081  *	IGMP handling (alias multicast ICMPv6 messages)
1082  */
1083 
1084 static void igmp6_group_queried(struct ifmcaddr6 *ma, unsigned long resptime)
1085 {
1086 	unsigned long delay = resptime;
1087 
1088 	/* Do not start timer for these addresses */
1089 	if (ipv6_addr_is_ll_all_nodes(&ma->mca_addr) ||
1090 	    IPV6_ADDR_MC_SCOPE(&ma->mca_addr) < IPV6_ADDR_SCOPE_LINKLOCAL)
1091 		return;
1092 
1093 	if (del_timer(&ma->mca_timer)) {
1094 		refcount_dec(&ma->mca_refcnt);
1095 		delay = ma->mca_timer.expires - jiffies;
1096 	}
1097 
1098 	if (delay >= resptime)
1099 		delay = prandom_u32() % resptime;
1100 
1101 	ma->mca_timer.expires = jiffies + delay;
1102 	if (!mod_timer(&ma->mca_timer, jiffies + delay))
1103 		refcount_inc(&ma->mca_refcnt);
1104 	ma->mca_flags |= MAF_TIMER_RUNNING;
1105 }
1106 
1107 /* mark EXCLUDE-mode sources */
1108 static bool mld_xmarksources(struct ifmcaddr6 *pmc, int nsrcs,
1109 			     const struct in6_addr *srcs)
1110 {
1111 	struct ip6_sf_list *psf;
1112 	int i, scount;
1113 
1114 	scount = 0;
1115 	for (psf = pmc->mca_sources; psf; psf = psf->sf_next) {
1116 		if (scount == nsrcs)
1117 			break;
1118 		for (i = 0; i < nsrcs; i++) {
1119 			/* skip inactive filters */
1120 			if (psf->sf_count[MCAST_INCLUDE] ||
1121 			    pmc->mca_sfcount[MCAST_EXCLUDE] !=
1122 			    psf->sf_count[MCAST_EXCLUDE])
1123 				break;
1124 			if (ipv6_addr_equal(&srcs[i], &psf->sf_addr)) {
1125 				scount++;
1126 				break;
1127 			}
1128 		}
1129 	}
1130 	pmc->mca_flags &= ~MAF_GSQUERY;
1131 	if (scount == nsrcs)	/* all sources excluded */
1132 		return false;
1133 	return true;
1134 }
1135 
1136 static bool mld_marksources(struct ifmcaddr6 *pmc, int nsrcs,
1137 			    const struct in6_addr *srcs)
1138 {
1139 	struct ip6_sf_list *psf;
1140 	int i, scount;
1141 
1142 	if (pmc->mca_sfmode == MCAST_EXCLUDE)
1143 		return mld_xmarksources(pmc, nsrcs, srcs);
1144 
1145 	/* mark INCLUDE-mode sources */
1146 
1147 	scount = 0;
1148 	for (psf = pmc->mca_sources; psf; psf = psf->sf_next) {
1149 		if (scount == nsrcs)
1150 			break;
1151 		for (i = 0; i < nsrcs; i++) {
1152 			if (ipv6_addr_equal(&srcs[i], &psf->sf_addr)) {
1153 				psf->sf_gsresp = 1;
1154 				scount++;
1155 				break;
1156 			}
1157 		}
1158 	}
1159 	if (!scount) {
1160 		pmc->mca_flags &= ~MAF_GSQUERY;
1161 		return false;
1162 	}
1163 	pmc->mca_flags |= MAF_GSQUERY;
1164 	return true;
1165 }
1166 
1167 static int mld_force_mld_version(const struct inet6_dev *idev)
1168 {
1169 	/* Normally, both are 0 here. If enforcement to a particular is
1170 	 * being used, individual device enforcement will have a lower
1171 	 * precedence over 'all' device (.../conf/all/force_mld_version).
1172 	 */
1173 
1174 	if (dev_net(idev->dev)->ipv6.devconf_all->force_mld_version != 0)
1175 		return dev_net(idev->dev)->ipv6.devconf_all->force_mld_version;
1176 	else
1177 		return idev->cnf.force_mld_version;
1178 }
1179 
1180 static bool mld_in_v2_mode_only(const struct inet6_dev *idev)
1181 {
1182 	return mld_force_mld_version(idev) == 2;
1183 }
1184 
1185 static bool mld_in_v1_mode_only(const struct inet6_dev *idev)
1186 {
1187 	return mld_force_mld_version(idev) == 1;
1188 }
1189 
1190 static bool mld_in_v1_mode(const struct inet6_dev *idev)
1191 {
1192 	if (mld_in_v2_mode_only(idev))
1193 		return false;
1194 	if (mld_in_v1_mode_only(idev))
1195 		return true;
1196 	if (idev->mc_v1_seen && time_before(jiffies, idev->mc_v1_seen))
1197 		return true;
1198 
1199 	return false;
1200 }
1201 
1202 static void mld_set_v1_mode(struct inet6_dev *idev)
1203 {
1204 	/* RFC3810, relevant sections:
1205 	 *  - 9.1. Robustness Variable
1206 	 *  - 9.2. Query Interval
1207 	 *  - 9.3. Query Response Interval
1208 	 *  - 9.12. Older Version Querier Present Timeout
1209 	 */
1210 	unsigned long switchback;
1211 
1212 	switchback = (idev->mc_qrv * idev->mc_qi) + idev->mc_qri;
1213 
1214 	idev->mc_v1_seen = jiffies + switchback;
1215 }
1216 
1217 static void mld_update_qrv(struct inet6_dev *idev,
1218 			   const struct mld2_query *mlh2)
1219 {
1220 	/* RFC3810, relevant sections:
1221 	 *  - 5.1.8. QRV (Querier's Robustness Variable)
1222 	 *  - 9.1. Robustness Variable
1223 	 */
1224 
1225 	/* The value of the Robustness Variable MUST NOT be zero,
1226 	 * and SHOULD NOT be one. Catch this here if we ever run
1227 	 * into such a case in future.
1228 	 */
1229 	const int min_qrv = min(MLD_QRV_DEFAULT, sysctl_mld_qrv);
1230 	WARN_ON(idev->mc_qrv == 0);
1231 
1232 	if (mlh2->mld2q_qrv > 0)
1233 		idev->mc_qrv = mlh2->mld2q_qrv;
1234 
1235 	if (unlikely(idev->mc_qrv < min_qrv)) {
1236 		net_warn_ratelimited("IPv6: MLD: clamping QRV from %u to %u!\n",
1237 				     idev->mc_qrv, min_qrv);
1238 		idev->mc_qrv = min_qrv;
1239 	}
1240 }
1241 
1242 static void mld_update_qi(struct inet6_dev *idev,
1243 			  const struct mld2_query *mlh2)
1244 {
1245 	/* RFC3810, relevant sections:
1246 	 *  - 5.1.9. QQIC (Querier's Query Interval Code)
1247 	 *  - 9.2. Query Interval
1248 	 *  - 9.12. Older Version Querier Present Timeout
1249 	 *    (the [Query Interval] in the last Query received)
1250 	 */
1251 	unsigned long mc_qqi;
1252 
1253 	if (mlh2->mld2q_qqic < 128) {
1254 		mc_qqi = mlh2->mld2q_qqic;
1255 	} else {
1256 		unsigned long mc_man, mc_exp;
1257 
1258 		mc_exp = MLDV2_QQIC_EXP(mlh2->mld2q_qqic);
1259 		mc_man = MLDV2_QQIC_MAN(mlh2->mld2q_qqic);
1260 
1261 		mc_qqi = (mc_man | 0x10) << (mc_exp + 3);
1262 	}
1263 
1264 	idev->mc_qi = mc_qqi * HZ;
1265 }
1266 
1267 static void mld_update_qri(struct inet6_dev *idev,
1268 			   const struct mld2_query *mlh2)
1269 {
1270 	/* RFC3810, relevant sections:
1271 	 *  - 5.1.3. Maximum Response Code
1272 	 *  - 9.3. Query Response Interval
1273 	 */
1274 	idev->mc_qri = msecs_to_jiffies(mldv2_mrc(mlh2));
1275 }
1276 
1277 static int mld_process_v1(struct inet6_dev *idev, struct mld_msg *mld,
1278 			  unsigned long *max_delay, bool v1_query)
1279 {
1280 	unsigned long mldv1_md;
1281 
1282 	/* Ignore v1 queries */
1283 	if (mld_in_v2_mode_only(idev))
1284 		return -EINVAL;
1285 
1286 	mldv1_md = ntohs(mld->mld_maxdelay);
1287 
1288 	/* When in MLDv1 fallback and a MLDv2 router start-up being
1289 	 * unaware of current MLDv1 operation, the MRC == MRD mapping
1290 	 * only works when the exponential algorithm is not being
1291 	 * used (as MLDv1 is unaware of such things).
1292 	 *
1293 	 * According to the RFC author, the MLDv2 implementations
1294 	 * he's aware of all use a MRC < 32768 on start up queries.
1295 	 *
1296 	 * Thus, should we *ever* encounter something else larger
1297 	 * than that, just assume the maximum possible within our
1298 	 * reach.
1299 	 */
1300 	if (!v1_query)
1301 		mldv1_md = min(mldv1_md, MLDV1_MRD_MAX_COMPAT);
1302 
1303 	*max_delay = max(msecs_to_jiffies(mldv1_md), 1UL);
1304 
1305 	/* MLDv1 router present: we need to go into v1 mode *only*
1306 	 * when an MLDv1 query is received as per section 9.12. of
1307 	 * RFC3810! And we know from RFC2710 section 3.7 that MLDv1
1308 	 * queries MUST be of exactly 24 octets.
1309 	 */
1310 	if (v1_query)
1311 		mld_set_v1_mode(idev);
1312 
1313 	/* cancel MLDv2 report timer */
1314 	mld_gq_stop_timer(idev);
1315 	/* cancel the interface change timer */
1316 	mld_ifc_stop_timer(idev);
1317 	/* clear deleted report items */
1318 	mld_clear_delrec(idev);
1319 
1320 	return 0;
1321 }
1322 
1323 static int mld_process_v2(struct inet6_dev *idev, struct mld2_query *mld,
1324 			  unsigned long *max_delay)
1325 {
1326 	*max_delay = max(msecs_to_jiffies(mldv2_mrc(mld)), 1UL);
1327 
1328 	mld_update_qrv(idev, mld);
1329 	mld_update_qi(idev, mld);
1330 	mld_update_qri(idev, mld);
1331 
1332 	idev->mc_maxdelay = *max_delay;
1333 
1334 	return 0;
1335 }
1336 
1337 /* called with rcu_read_lock() */
1338 int igmp6_event_query(struct sk_buff *skb)
1339 {
1340 	struct mld2_query *mlh2 = NULL;
1341 	struct ifmcaddr6 *ma;
1342 	const struct in6_addr *group;
1343 	unsigned long max_delay;
1344 	struct inet6_dev *idev;
1345 	struct mld_msg *mld;
1346 	int group_type;
1347 	int mark = 0;
1348 	int len, err;
1349 
1350 	if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
1351 		return -EINVAL;
1352 
1353 	/* compute payload length excluding extension headers */
1354 	len = ntohs(ipv6_hdr(skb)->payload_len) + sizeof(struct ipv6hdr);
1355 	len -= skb_network_header_len(skb);
1356 
1357 	/* RFC3810 6.2
1358 	 * Upon reception of an MLD message that contains a Query, the node
1359 	 * checks if the source address of the message is a valid link-local
1360 	 * address, if the Hop Limit is set to 1, and if the Router Alert
1361 	 * option is present in the Hop-By-Hop Options header of the IPv6
1362 	 * packet.  If any of these checks fails, the packet is dropped.
1363 	 */
1364 	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL) ||
1365 	    ipv6_hdr(skb)->hop_limit != 1 ||
1366 	    !(IP6CB(skb)->flags & IP6SKB_ROUTERALERT) ||
1367 	    IP6CB(skb)->ra != htons(IPV6_OPT_ROUTERALERT_MLD))
1368 		return -EINVAL;
1369 
1370 	idev = __in6_dev_get(skb->dev);
1371 	if (!idev)
1372 		return 0;
1373 
1374 	mld = (struct mld_msg *)icmp6_hdr(skb);
1375 	group = &mld->mld_mca;
1376 	group_type = ipv6_addr_type(group);
1377 
1378 	if (group_type != IPV6_ADDR_ANY &&
1379 	    !(group_type&IPV6_ADDR_MULTICAST))
1380 		return -EINVAL;
1381 
1382 	if (len < MLD_V1_QUERY_LEN) {
1383 		return -EINVAL;
1384 	} else if (len == MLD_V1_QUERY_LEN || mld_in_v1_mode(idev)) {
1385 		err = mld_process_v1(idev, mld, &max_delay,
1386 				     len == MLD_V1_QUERY_LEN);
1387 		if (err < 0)
1388 			return err;
1389 	} else if (len >= MLD_V2_QUERY_LEN_MIN) {
1390 		int srcs_offset = sizeof(struct mld2_query) -
1391 				  sizeof(struct icmp6hdr);
1392 
1393 		if (!pskb_may_pull(skb, srcs_offset))
1394 			return -EINVAL;
1395 
1396 		mlh2 = (struct mld2_query *)skb_transport_header(skb);
1397 
1398 		err = mld_process_v2(idev, mlh2, &max_delay);
1399 		if (err < 0)
1400 			return err;
1401 
1402 		if (group_type == IPV6_ADDR_ANY) { /* general query */
1403 			if (mlh2->mld2q_nsrcs)
1404 				return -EINVAL; /* no sources allowed */
1405 
1406 			mld_gq_start_timer(idev);
1407 			return 0;
1408 		}
1409 		/* mark sources to include, if group & source-specific */
1410 		if (mlh2->mld2q_nsrcs != 0) {
1411 			if (!pskb_may_pull(skb, srcs_offset +
1412 			    ntohs(mlh2->mld2q_nsrcs) * sizeof(struct in6_addr)))
1413 				return -EINVAL;
1414 
1415 			mlh2 = (struct mld2_query *)skb_transport_header(skb);
1416 			mark = 1;
1417 		}
1418 	} else {
1419 		return -EINVAL;
1420 	}
1421 
1422 	read_lock_bh(&idev->lock);
1423 	if (group_type == IPV6_ADDR_ANY) {
1424 		for (ma = idev->mc_list; ma; ma = ma->next) {
1425 			spin_lock_bh(&ma->mca_lock);
1426 			igmp6_group_queried(ma, max_delay);
1427 			spin_unlock_bh(&ma->mca_lock);
1428 		}
1429 	} else {
1430 		for (ma = idev->mc_list; ma; ma = ma->next) {
1431 			if (!ipv6_addr_equal(group, &ma->mca_addr))
1432 				continue;
1433 			spin_lock_bh(&ma->mca_lock);
1434 			if (ma->mca_flags & MAF_TIMER_RUNNING) {
1435 				/* gsquery <- gsquery && mark */
1436 				if (!mark)
1437 					ma->mca_flags &= ~MAF_GSQUERY;
1438 			} else {
1439 				/* gsquery <- mark */
1440 				if (mark)
1441 					ma->mca_flags |= MAF_GSQUERY;
1442 				else
1443 					ma->mca_flags &= ~MAF_GSQUERY;
1444 			}
1445 			if (!(ma->mca_flags & MAF_GSQUERY) ||
1446 			    mld_marksources(ma, ntohs(mlh2->mld2q_nsrcs), mlh2->mld2q_srcs))
1447 				igmp6_group_queried(ma, max_delay);
1448 			spin_unlock_bh(&ma->mca_lock);
1449 			break;
1450 		}
1451 	}
1452 	read_unlock_bh(&idev->lock);
1453 
1454 	return 0;
1455 }
1456 
1457 /* called with rcu_read_lock() */
1458 int igmp6_event_report(struct sk_buff *skb)
1459 {
1460 	struct ifmcaddr6 *ma;
1461 	struct inet6_dev *idev;
1462 	struct mld_msg *mld;
1463 	int addr_type;
1464 
1465 	/* Our own report looped back. Ignore it. */
1466 	if (skb->pkt_type == PACKET_LOOPBACK)
1467 		return 0;
1468 
1469 	/* send our report if the MC router may not have heard this report */
1470 	if (skb->pkt_type != PACKET_MULTICAST &&
1471 	    skb->pkt_type != PACKET_BROADCAST)
1472 		return 0;
1473 
1474 	if (!pskb_may_pull(skb, sizeof(*mld) - sizeof(struct icmp6hdr)))
1475 		return -EINVAL;
1476 
1477 	mld = (struct mld_msg *)icmp6_hdr(skb);
1478 
1479 	/* Drop reports with not link local source */
1480 	addr_type = ipv6_addr_type(&ipv6_hdr(skb)->saddr);
1481 	if (addr_type != IPV6_ADDR_ANY &&
1482 	    !(addr_type&IPV6_ADDR_LINKLOCAL))
1483 		return -EINVAL;
1484 
1485 	idev = __in6_dev_get(skb->dev);
1486 	if (!idev)
1487 		return -ENODEV;
1488 
1489 	/*
1490 	 *	Cancel the timer for this group
1491 	 */
1492 
1493 	read_lock_bh(&idev->lock);
1494 	for (ma = idev->mc_list; ma; ma = ma->next) {
1495 		if (ipv6_addr_equal(&ma->mca_addr, &mld->mld_mca)) {
1496 			spin_lock(&ma->mca_lock);
1497 			if (del_timer(&ma->mca_timer))
1498 				refcount_dec(&ma->mca_refcnt);
1499 			ma->mca_flags &= ~(MAF_LAST_REPORTER|MAF_TIMER_RUNNING);
1500 			spin_unlock(&ma->mca_lock);
1501 			break;
1502 		}
1503 	}
1504 	read_unlock_bh(&idev->lock);
1505 	return 0;
1506 }
1507 
1508 static bool is_in(struct ifmcaddr6 *pmc, struct ip6_sf_list *psf, int type,
1509 		  int gdeleted, int sdeleted)
1510 {
1511 	switch (type) {
1512 	case MLD2_MODE_IS_INCLUDE:
1513 	case MLD2_MODE_IS_EXCLUDE:
1514 		if (gdeleted || sdeleted)
1515 			return false;
1516 		if (!((pmc->mca_flags & MAF_GSQUERY) && !psf->sf_gsresp)) {
1517 			if (pmc->mca_sfmode == MCAST_INCLUDE)
1518 				return true;
1519 			/* don't include if this source is excluded
1520 			 * in all filters
1521 			 */
1522 			if (psf->sf_count[MCAST_INCLUDE])
1523 				return type == MLD2_MODE_IS_INCLUDE;
1524 			return pmc->mca_sfcount[MCAST_EXCLUDE] ==
1525 				psf->sf_count[MCAST_EXCLUDE];
1526 		}
1527 		return false;
1528 	case MLD2_CHANGE_TO_INCLUDE:
1529 		if (gdeleted || sdeleted)
1530 			return false;
1531 		return psf->sf_count[MCAST_INCLUDE] != 0;
1532 	case MLD2_CHANGE_TO_EXCLUDE:
1533 		if (gdeleted || sdeleted)
1534 			return false;
1535 		if (pmc->mca_sfcount[MCAST_EXCLUDE] == 0 ||
1536 		    psf->sf_count[MCAST_INCLUDE])
1537 			return false;
1538 		return pmc->mca_sfcount[MCAST_EXCLUDE] ==
1539 			psf->sf_count[MCAST_EXCLUDE];
1540 	case MLD2_ALLOW_NEW_SOURCES:
1541 		if (gdeleted || !psf->sf_crcount)
1542 			return false;
1543 		return (pmc->mca_sfmode == MCAST_INCLUDE) ^ sdeleted;
1544 	case MLD2_BLOCK_OLD_SOURCES:
1545 		if (pmc->mca_sfmode == MCAST_INCLUDE)
1546 			return gdeleted || (psf->sf_crcount && sdeleted);
1547 		return psf->sf_crcount && !gdeleted && !sdeleted;
1548 	}
1549 	return false;
1550 }
1551 
1552 static int
1553 mld_scount(struct ifmcaddr6 *pmc, int type, int gdeleted, int sdeleted)
1554 {
1555 	struct ip6_sf_list *psf;
1556 	int scount = 0;
1557 
1558 	for (psf = pmc->mca_sources; psf; psf = psf->sf_next) {
1559 		if (!is_in(pmc, psf, type, gdeleted, sdeleted))
1560 			continue;
1561 		scount++;
1562 	}
1563 	return scount;
1564 }
1565 
1566 static void ip6_mc_hdr(struct sock *sk, struct sk_buff *skb,
1567 		       struct net_device *dev,
1568 		       const struct in6_addr *saddr,
1569 		       const struct in6_addr *daddr,
1570 		       int proto, int len)
1571 {
1572 	struct ipv6hdr *hdr;
1573 
1574 	skb->protocol = htons(ETH_P_IPV6);
1575 	skb->dev = dev;
1576 
1577 	skb_reset_network_header(skb);
1578 	skb_put(skb, sizeof(struct ipv6hdr));
1579 	hdr = ipv6_hdr(skb);
1580 
1581 	ip6_flow_hdr(hdr, 0, 0);
1582 
1583 	hdr->payload_len = htons(len);
1584 	hdr->nexthdr = proto;
1585 	hdr->hop_limit = inet6_sk(sk)->hop_limit;
1586 
1587 	hdr->saddr = *saddr;
1588 	hdr->daddr = *daddr;
1589 }
1590 
1591 static struct sk_buff *mld_newpack(struct inet6_dev *idev, unsigned int mtu)
1592 {
1593 	struct net_device *dev = idev->dev;
1594 	struct net *net = dev_net(dev);
1595 	struct sock *sk = net->ipv6.igmp_sk;
1596 	struct sk_buff *skb;
1597 	struct mld2_report *pmr;
1598 	struct in6_addr addr_buf;
1599 	const struct in6_addr *saddr;
1600 	int hlen = LL_RESERVED_SPACE(dev);
1601 	int tlen = dev->needed_tailroom;
1602 	unsigned int size = mtu + hlen + tlen;
1603 	int err;
1604 	u8 ra[8] = { IPPROTO_ICMPV6, 0,
1605 		     IPV6_TLV_ROUTERALERT, 2, 0, 0,
1606 		     IPV6_TLV_PADN, 0 };
1607 
1608 	/* we assume size > sizeof(ra) here */
1609 	/* limit our allocations to order-0 page */
1610 	size = min_t(int, size, SKB_MAX_ORDER(0, 0));
1611 	skb = sock_alloc_send_skb(sk, size, 1, &err);
1612 
1613 	if (!skb)
1614 		return NULL;
1615 
1616 	skb->priority = TC_PRIO_CONTROL;
1617 	skb_reserve(skb, hlen);
1618 	skb_tailroom_reserve(skb, mtu, tlen);
1619 
1620 	if (__ipv6_get_lladdr(idev, &addr_buf, IFA_F_TENTATIVE)) {
1621 		/* <draft-ietf-magma-mld-source-05.txt>:
1622 		 * use unspecified address as the source address
1623 		 * when a valid link-local address is not available.
1624 		 */
1625 		saddr = &in6addr_any;
1626 	} else
1627 		saddr = &addr_buf;
1628 
1629 	ip6_mc_hdr(sk, skb, dev, saddr, &mld2_all_mcr, NEXTHDR_HOP, 0);
1630 
1631 	skb_put_data(skb, ra, sizeof(ra));
1632 
1633 	skb_set_transport_header(skb, skb_tail_pointer(skb) - skb->data);
1634 	skb_put(skb, sizeof(*pmr));
1635 	pmr = (struct mld2_report *)skb_transport_header(skb);
1636 	pmr->mld2r_type = ICMPV6_MLD2_REPORT;
1637 	pmr->mld2r_resv1 = 0;
1638 	pmr->mld2r_cksum = 0;
1639 	pmr->mld2r_resv2 = 0;
1640 	pmr->mld2r_ngrec = 0;
1641 	return skb;
1642 }
1643 
1644 static void mld_sendpack(struct sk_buff *skb)
1645 {
1646 	struct ipv6hdr *pip6 = ipv6_hdr(skb);
1647 	struct mld2_report *pmr =
1648 			      (struct mld2_report *)skb_transport_header(skb);
1649 	int payload_len, mldlen;
1650 	struct inet6_dev *idev;
1651 	struct net *net = dev_net(skb->dev);
1652 	int err;
1653 	struct flowi6 fl6;
1654 	struct dst_entry *dst;
1655 
1656 	rcu_read_lock();
1657 	idev = __in6_dev_get(skb->dev);
1658 	IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
1659 
1660 	payload_len = (skb_tail_pointer(skb) - skb_network_header(skb)) -
1661 		sizeof(*pip6);
1662 	mldlen = skb_tail_pointer(skb) - skb_transport_header(skb);
1663 	pip6->payload_len = htons(payload_len);
1664 
1665 	pmr->mld2r_cksum = csum_ipv6_magic(&pip6->saddr, &pip6->daddr, mldlen,
1666 					   IPPROTO_ICMPV6,
1667 					   csum_partial(skb_transport_header(skb),
1668 							mldlen, 0));
1669 
1670 	icmpv6_flow_init(net->ipv6.igmp_sk, &fl6, ICMPV6_MLD2_REPORT,
1671 			 &ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
1672 			 skb->dev->ifindex);
1673 	dst = icmp6_dst_alloc(skb->dev, &fl6);
1674 
1675 	err = 0;
1676 	if (IS_ERR(dst)) {
1677 		err = PTR_ERR(dst);
1678 		dst = NULL;
1679 	}
1680 	skb_dst_set(skb, dst);
1681 	if (err)
1682 		goto err_out;
1683 
1684 	err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
1685 		      net, net->ipv6.igmp_sk, skb, NULL, skb->dev,
1686 		      dst_output);
1687 out:
1688 	if (!err) {
1689 		ICMP6MSGOUT_INC_STATS(net, idev, ICMPV6_MLD2_REPORT);
1690 		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
1691 	} else {
1692 		IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
1693 	}
1694 
1695 	rcu_read_unlock();
1696 	return;
1697 
1698 err_out:
1699 	kfree_skb(skb);
1700 	goto out;
1701 }
1702 
1703 static int grec_size(struct ifmcaddr6 *pmc, int type, int gdel, int sdel)
1704 {
1705 	return sizeof(struct mld2_grec) + 16 * mld_scount(pmc,type,gdel,sdel);
1706 }
1707 
1708 static struct sk_buff *add_grhead(struct sk_buff *skb, struct ifmcaddr6 *pmc,
1709 	int type, struct mld2_grec **ppgr, unsigned int mtu)
1710 {
1711 	struct mld2_report *pmr;
1712 	struct mld2_grec *pgr;
1713 
1714 	if (!skb) {
1715 		skb = mld_newpack(pmc->idev, mtu);
1716 		if (!skb)
1717 			return NULL;
1718 	}
1719 	pgr = skb_put(skb, sizeof(struct mld2_grec));
1720 	pgr->grec_type = type;
1721 	pgr->grec_auxwords = 0;
1722 	pgr->grec_nsrcs = 0;
1723 	pgr->grec_mca = pmc->mca_addr;	/* structure copy */
1724 	pmr = (struct mld2_report *)skb_transport_header(skb);
1725 	pmr->mld2r_ngrec = htons(ntohs(pmr->mld2r_ngrec)+1);
1726 	*ppgr = pgr;
1727 	return skb;
1728 }
1729 
1730 #define AVAILABLE(skb)	((skb) ? skb_availroom(skb) : 0)
1731 
1732 static struct sk_buff *add_grec(struct sk_buff *skb, struct ifmcaddr6 *pmc,
1733 	int type, int gdeleted, int sdeleted, int crsend)
1734 {
1735 	struct inet6_dev *idev = pmc->idev;
1736 	struct net_device *dev = idev->dev;
1737 	struct mld2_report *pmr;
1738 	struct mld2_grec *pgr = NULL;
1739 	struct ip6_sf_list *psf, *psf_next, *psf_prev, **psf_list;
1740 	int scount, stotal, first, isquery, truncate;
1741 	unsigned int mtu;
1742 
1743 	if (pmc->mca_flags & MAF_NOREPORT)
1744 		return skb;
1745 
1746 	mtu = READ_ONCE(dev->mtu);
1747 	if (mtu < IPV6_MIN_MTU)
1748 		return skb;
1749 
1750 	isquery = type == MLD2_MODE_IS_INCLUDE ||
1751 		  type == MLD2_MODE_IS_EXCLUDE;
1752 	truncate = type == MLD2_MODE_IS_EXCLUDE ||
1753 		    type == MLD2_CHANGE_TO_EXCLUDE;
1754 
1755 	stotal = scount = 0;
1756 
1757 	psf_list = sdeleted ? &pmc->mca_tomb : &pmc->mca_sources;
1758 
1759 	if (!*psf_list)
1760 		goto empty_source;
1761 
1762 	pmr = skb ? (struct mld2_report *)skb_transport_header(skb) : NULL;
1763 
1764 	/* EX and TO_EX get a fresh packet, if needed */
1765 	if (truncate) {
1766 		if (pmr && pmr->mld2r_ngrec &&
1767 		    AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) {
1768 			if (skb)
1769 				mld_sendpack(skb);
1770 			skb = mld_newpack(idev, mtu);
1771 		}
1772 	}
1773 	first = 1;
1774 	psf_prev = NULL;
1775 	for (psf = *psf_list; psf; psf = psf_next) {
1776 		struct in6_addr *psrc;
1777 
1778 		psf_next = psf->sf_next;
1779 
1780 		if (!is_in(pmc, psf, type, gdeleted, sdeleted) && !crsend) {
1781 			psf_prev = psf;
1782 			continue;
1783 		}
1784 
1785 		/* Based on RFC3810 6.1. Should not send source-list change
1786 		 * records when there is a filter mode change.
1787 		 */
1788 		if (((gdeleted && pmc->mca_sfmode == MCAST_EXCLUDE) ||
1789 		     (!gdeleted && pmc->mca_crcount)) &&
1790 		    (type == MLD2_ALLOW_NEW_SOURCES ||
1791 		     type == MLD2_BLOCK_OLD_SOURCES) && psf->sf_crcount)
1792 			goto decrease_sf_crcount;
1793 
1794 		/* clear marks on query responses */
1795 		if (isquery)
1796 			psf->sf_gsresp = 0;
1797 
1798 		if (AVAILABLE(skb) < sizeof(*psrc) +
1799 		    first*sizeof(struct mld2_grec)) {
1800 			if (truncate && !first)
1801 				break;	 /* truncate these */
1802 			if (pgr)
1803 				pgr->grec_nsrcs = htons(scount);
1804 			if (skb)
1805 				mld_sendpack(skb);
1806 			skb = mld_newpack(idev, mtu);
1807 			first = 1;
1808 			scount = 0;
1809 		}
1810 		if (first) {
1811 			skb = add_grhead(skb, pmc, type, &pgr, mtu);
1812 			first = 0;
1813 		}
1814 		if (!skb)
1815 			return NULL;
1816 		psrc = skb_put(skb, sizeof(*psrc));
1817 		*psrc = psf->sf_addr;
1818 		scount++; stotal++;
1819 		if ((type == MLD2_ALLOW_NEW_SOURCES ||
1820 		     type == MLD2_BLOCK_OLD_SOURCES) && psf->sf_crcount) {
1821 decrease_sf_crcount:
1822 			psf->sf_crcount--;
1823 			if ((sdeleted || gdeleted) && psf->sf_crcount == 0) {
1824 				if (psf_prev)
1825 					psf_prev->sf_next = psf->sf_next;
1826 				else
1827 					*psf_list = psf->sf_next;
1828 				kfree(psf);
1829 				continue;
1830 			}
1831 		}
1832 		psf_prev = psf;
1833 	}
1834 
1835 empty_source:
1836 	if (!stotal) {
1837 		if (type == MLD2_ALLOW_NEW_SOURCES ||
1838 		    type == MLD2_BLOCK_OLD_SOURCES)
1839 			return skb;
1840 		if (pmc->mca_crcount || isquery || crsend) {
1841 			/* make sure we have room for group header */
1842 			if (skb && AVAILABLE(skb) < sizeof(struct mld2_grec)) {
1843 				mld_sendpack(skb);
1844 				skb = NULL; /* add_grhead will get a new one */
1845 			}
1846 			skb = add_grhead(skb, pmc, type, &pgr, mtu);
1847 		}
1848 	}
1849 	if (pgr)
1850 		pgr->grec_nsrcs = htons(scount);
1851 
1852 	if (isquery)
1853 		pmc->mca_flags &= ~MAF_GSQUERY;	/* clear query state */
1854 	return skb;
1855 }
1856 
1857 static void mld_send_report(struct inet6_dev *idev, struct ifmcaddr6 *pmc)
1858 {
1859 	struct sk_buff *skb = NULL;
1860 	int type;
1861 
1862 	read_lock_bh(&idev->lock);
1863 	if (!pmc) {
1864 		for (pmc = idev->mc_list; pmc; pmc = pmc->next) {
1865 			if (pmc->mca_flags & MAF_NOREPORT)
1866 				continue;
1867 			spin_lock_bh(&pmc->mca_lock);
1868 			if (pmc->mca_sfcount[MCAST_EXCLUDE])
1869 				type = MLD2_MODE_IS_EXCLUDE;
1870 			else
1871 				type = MLD2_MODE_IS_INCLUDE;
1872 			skb = add_grec(skb, pmc, type, 0, 0, 0);
1873 			spin_unlock_bh(&pmc->mca_lock);
1874 		}
1875 	} else {
1876 		spin_lock_bh(&pmc->mca_lock);
1877 		if (pmc->mca_sfcount[MCAST_EXCLUDE])
1878 			type = MLD2_MODE_IS_EXCLUDE;
1879 		else
1880 			type = MLD2_MODE_IS_INCLUDE;
1881 		skb = add_grec(skb, pmc, type, 0, 0, 0);
1882 		spin_unlock_bh(&pmc->mca_lock);
1883 	}
1884 	read_unlock_bh(&idev->lock);
1885 	if (skb)
1886 		mld_sendpack(skb);
1887 }
1888 
1889 /*
1890  * remove zero-count source records from a source filter list
1891  */
1892 static void mld_clear_zeros(struct ip6_sf_list **ppsf)
1893 {
1894 	struct ip6_sf_list *psf_prev, *psf_next, *psf;
1895 
1896 	psf_prev = NULL;
1897 	for (psf = *ppsf; psf; psf = psf_next) {
1898 		psf_next = psf->sf_next;
1899 		if (psf->sf_crcount == 0) {
1900 			if (psf_prev)
1901 				psf_prev->sf_next = psf->sf_next;
1902 			else
1903 				*ppsf = psf->sf_next;
1904 			kfree(psf);
1905 		} else
1906 			psf_prev = psf;
1907 	}
1908 }
1909 
1910 static void mld_send_cr(struct inet6_dev *idev)
1911 {
1912 	struct ifmcaddr6 *pmc, *pmc_prev, *pmc_next;
1913 	struct sk_buff *skb = NULL;
1914 	int type, dtype;
1915 
1916 	read_lock_bh(&idev->lock);
1917 	spin_lock(&idev->mc_lock);
1918 
1919 	/* deleted MCA's */
1920 	pmc_prev = NULL;
1921 	for (pmc = idev->mc_tomb; pmc; pmc = pmc_next) {
1922 		pmc_next = pmc->next;
1923 		if (pmc->mca_sfmode == MCAST_INCLUDE) {
1924 			type = MLD2_BLOCK_OLD_SOURCES;
1925 			dtype = MLD2_BLOCK_OLD_SOURCES;
1926 			skb = add_grec(skb, pmc, type, 1, 0, 0);
1927 			skb = add_grec(skb, pmc, dtype, 1, 1, 0);
1928 		}
1929 		if (pmc->mca_crcount) {
1930 			if (pmc->mca_sfmode == MCAST_EXCLUDE) {
1931 				type = MLD2_CHANGE_TO_INCLUDE;
1932 				skb = add_grec(skb, pmc, type, 1, 0, 0);
1933 			}
1934 			pmc->mca_crcount--;
1935 			if (pmc->mca_crcount == 0) {
1936 				mld_clear_zeros(&pmc->mca_tomb);
1937 				mld_clear_zeros(&pmc->mca_sources);
1938 			}
1939 		}
1940 		if (pmc->mca_crcount == 0 && !pmc->mca_tomb &&
1941 		    !pmc->mca_sources) {
1942 			if (pmc_prev)
1943 				pmc_prev->next = pmc_next;
1944 			else
1945 				idev->mc_tomb = pmc_next;
1946 			in6_dev_put(pmc->idev);
1947 			kfree(pmc);
1948 		} else
1949 			pmc_prev = pmc;
1950 	}
1951 	spin_unlock(&idev->mc_lock);
1952 
1953 	/* change recs */
1954 	for (pmc = idev->mc_list; pmc; pmc = pmc->next) {
1955 		spin_lock_bh(&pmc->mca_lock);
1956 		if (pmc->mca_sfcount[MCAST_EXCLUDE]) {
1957 			type = MLD2_BLOCK_OLD_SOURCES;
1958 			dtype = MLD2_ALLOW_NEW_SOURCES;
1959 		} else {
1960 			type = MLD2_ALLOW_NEW_SOURCES;
1961 			dtype = MLD2_BLOCK_OLD_SOURCES;
1962 		}
1963 		skb = add_grec(skb, pmc, type, 0, 0, 0);
1964 		skb = add_grec(skb, pmc, dtype, 0, 1, 0);	/* deleted sources */
1965 
1966 		/* filter mode changes */
1967 		if (pmc->mca_crcount) {
1968 			if (pmc->mca_sfmode == MCAST_EXCLUDE)
1969 				type = MLD2_CHANGE_TO_EXCLUDE;
1970 			else
1971 				type = MLD2_CHANGE_TO_INCLUDE;
1972 			skb = add_grec(skb, pmc, type, 0, 0, 0);
1973 			pmc->mca_crcount--;
1974 		}
1975 		spin_unlock_bh(&pmc->mca_lock);
1976 	}
1977 	read_unlock_bh(&idev->lock);
1978 	if (!skb)
1979 		return;
1980 	(void) mld_sendpack(skb);
1981 }
1982 
1983 static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
1984 {
1985 	struct net *net = dev_net(dev);
1986 	struct sock *sk = net->ipv6.igmp_sk;
1987 	struct inet6_dev *idev;
1988 	struct sk_buff *skb;
1989 	struct mld_msg *hdr;
1990 	const struct in6_addr *snd_addr, *saddr;
1991 	struct in6_addr addr_buf;
1992 	int hlen = LL_RESERVED_SPACE(dev);
1993 	int tlen = dev->needed_tailroom;
1994 	int err, len, payload_len, full_len;
1995 	u8 ra[8] = { IPPROTO_ICMPV6, 0,
1996 		     IPV6_TLV_ROUTERALERT, 2, 0, 0,
1997 		     IPV6_TLV_PADN, 0 };
1998 	struct flowi6 fl6;
1999 	struct dst_entry *dst;
2000 
2001 	if (type == ICMPV6_MGM_REDUCTION)
2002 		snd_addr = &in6addr_linklocal_allrouters;
2003 	else
2004 		snd_addr = addr;
2005 
2006 	len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
2007 	payload_len = len + sizeof(ra);
2008 	full_len = sizeof(struct ipv6hdr) + payload_len;
2009 
2010 	rcu_read_lock();
2011 	IP6_UPD_PO_STATS(net, __in6_dev_get(dev),
2012 		      IPSTATS_MIB_OUT, full_len);
2013 	rcu_read_unlock();
2014 
2015 	skb = sock_alloc_send_skb(sk, hlen + tlen + full_len, 1, &err);
2016 
2017 	if (!skb) {
2018 		rcu_read_lock();
2019 		IP6_INC_STATS(net, __in6_dev_get(dev),
2020 			      IPSTATS_MIB_OUTDISCARDS);
2021 		rcu_read_unlock();
2022 		return;
2023 	}
2024 	skb->priority = TC_PRIO_CONTROL;
2025 	skb_reserve(skb, hlen);
2026 
2027 	if (ipv6_get_lladdr(dev, &addr_buf, IFA_F_TENTATIVE)) {
2028 		/* <draft-ietf-magma-mld-source-05.txt>:
2029 		 * use unspecified address as the source address
2030 		 * when a valid link-local address is not available.
2031 		 */
2032 		saddr = &in6addr_any;
2033 	} else
2034 		saddr = &addr_buf;
2035 
2036 	ip6_mc_hdr(sk, skb, dev, saddr, snd_addr, NEXTHDR_HOP, payload_len);
2037 
2038 	skb_put_data(skb, ra, sizeof(ra));
2039 
2040 	hdr = skb_put_zero(skb, sizeof(struct mld_msg));
2041 	hdr->mld_type = type;
2042 	hdr->mld_mca = *addr;
2043 
2044 	hdr->mld_cksum = csum_ipv6_magic(saddr, snd_addr, len,
2045 					 IPPROTO_ICMPV6,
2046 					 csum_partial(hdr, len, 0));
2047 
2048 	rcu_read_lock();
2049 	idev = __in6_dev_get(skb->dev);
2050 
2051 	icmpv6_flow_init(sk, &fl6, type,
2052 			 &ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
2053 			 skb->dev->ifindex);
2054 	dst = icmp6_dst_alloc(skb->dev, &fl6);
2055 	if (IS_ERR(dst)) {
2056 		err = PTR_ERR(dst);
2057 		goto err_out;
2058 	}
2059 
2060 	skb_dst_set(skb, dst);
2061 	err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
2062 		      net, sk, skb, NULL, skb->dev,
2063 		      dst_output);
2064 out:
2065 	if (!err) {
2066 		ICMP6MSGOUT_INC_STATS(net, idev, type);
2067 		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
2068 	} else
2069 		IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
2070 
2071 	rcu_read_unlock();
2072 	return;
2073 
2074 err_out:
2075 	kfree_skb(skb);
2076 	goto out;
2077 }
2078 
2079 static void mld_send_initial_cr(struct inet6_dev *idev)
2080 {
2081 	struct sk_buff *skb;
2082 	struct ifmcaddr6 *pmc;
2083 	int type;
2084 
2085 	if (mld_in_v1_mode(idev))
2086 		return;
2087 
2088 	skb = NULL;
2089 	read_lock_bh(&idev->lock);
2090 	for (pmc = idev->mc_list; pmc; pmc = pmc->next) {
2091 		spin_lock_bh(&pmc->mca_lock);
2092 		if (pmc->mca_sfcount[MCAST_EXCLUDE])
2093 			type = MLD2_CHANGE_TO_EXCLUDE;
2094 		else
2095 			type = MLD2_ALLOW_NEW_SOURCES;
2096 		skb = add_grec(skb, pmc, type, 0, 0, 1);
2097 		spin_unlock_bh(&pmc->mca_lock);
2098 	}
2099 	read_unlock_bh(&idev->lock);
2100 	if (skb)
2101 		mld_sendpack(skb);
2102 }
2103 
2104 void ipv6_mc_dad_complete(struct inet6_dev *idev)
2105 {
2106 	idev->mc_dad_count = idev->mc_qrv;
2107 	if (idev->mc_dad_count) {
2108 		mld_send_initial_cr(idev);
2109 		idev->mc_dad_count--;
2110 		if (idev->mc_dad_count)
2111 			mld_dad_start_timer(idev,
2112 					    unsolicited_report_interval(idev));
2113 	}
2114 }
2115 
2116 static void mld_dad_timer_expire(struct timer_list *t)
2117 {
2118 	struct inet6_dev *idev = from_timer(idev, t, mc_dad_timer);
2119 
2120 	mld_send_initial_cr(idev);
2121 	if (idev->mc_dad_count) {
2122 		idev->mc_dad_count--;
2123 		if (idev->mc_dad_count)
2124 			mld_dad_start_timer(idev,
2125 					    unsolicited_report_interval(idev));
2126 	}
2127 	in6_dev_put(idev);
2128 }
2129 
2130 static int ip6_mc_del1_src(struct ifmcaddr6 *pmc, int sfmode,
2131 	const struct in6_addr *psfsrc)
2132 {
2133 	struct ip6_sf_list *psf, *psf_prev;
2134 	int rv = 0;
2135 
2136 	psf_prev = NULL;
2137 	for (psf = pmc->mca_sources; psf; psf = psf->sf_next) {
2138 		if (ipv6_addr_equal(&psf->sf_addr, psfsrc))
2139 			break;
2140 		psf_prev = psf;
2141 	}
2142 	if (!psf || psf->sf_count[sfmode] == 0) {
2143 		/* source filter not found, or count wrong =>  bug */
2144 		return -ESRCH;
2145 	}
2146 	psf->sf_count[sfmode]--;
2147 	if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) {
2148 		struct inet6_dev *idev = pmc->idev;
2149 
2150 		/* no more filters for this source */
2151 		if (psf_prev)
2152 			psf_prev->sf_next = psf->sf_next;
2153 		else
2154 			pmc->mca_sources = psf->sf_next;
2155 		if (psf->sf_oldin && !(pmc->mca_flags & MAF_NOREPORT) &&
2156 		    !mld_in_v1_mode(idev)) {
2157 			psf->sf_crcount = idev->mc_qrv;
2158 			psf->sf_next = pmc->mca_tomb;
2159 			pmc->mca_tomb = psf;
2160 			rv = 1;
2161 		} else
2162 			kfree(psf);
2163 	}
2164 	return rv;
2165 }
2166 
2167 static int ip6_mc_del_src(struct inet6_dev *idev, const struct in6_addr *pmca,
2168 			  int sfmode, int sfcount, const struct in6_addr *psfsrc,
2169 			  int delta)
2170 {
2171 	struct ifmcaddr6 *pmc;
2172 	int	changerec = 0;
2173 	int	i, err;
2174 
2175 	if (!idev)
2176 		return -ENODEV;
2177 	read_lock_bh(&idev->lock);
2178 	for (pmc = idev->mc_list; pmc; pmc = pmc->next) {
2179 		if (ipv6_addr_equal(pmca, &pmc->mca_addr))
2180 			break;
2181 	}
2182 	if (!pmc) {
2183 		/* MCA not found?? bug */
2184 		read_unlock_bh(&idev->lock);
2185 		return -ESRCH;
2186 	}
2187 	spin_lock_bh(&pmc->mca_lock);
2188 	sf_markstate(pmc);
2189 	if (!delta) {
2190 		if (!pmc->mca_sfcount[sfmode]) {
2191 			spin_unlock_bh(&pmc->mca_lock);
2192 			read_unlock_bh(&idev->lock);
2193 			return -EINVAL;
2194 		}
2195 		pmc->mca_sfcount[sfmode]--;
2196 	}
2197 	err = 0;
2198 	for (i = 0; i < sfcount; i++) {
2199 		int rv = ip6_mc_del1_src(pmc, sfmode, &psfsrc[i]);
2200 
2201 		changerec |= rv > 0;
2202 		if (!err && rv < 0)
2203 			err = rv;
2204 	}
2205 	if (pmc->mca_sfmode == MCAST_EXCLUDE &&
2206 	    pmc->mca_sfcount[MCAST_EXCLUDE] == 0 &&
2207 	    pmc->mca_sfcount[MCAST_INCLUDE]) {
2208 		struct ip6_sf_list *psf;
2209 
2210 		/* filter mode change */
2211 		pmc->mca_sfmode = MCAST_INCLUDE;
2212 		pmc->mca_crcount = idev->mc_qrv;
2213 		idev->mc_ifc_count = pmc->mca_crcount;
2214 		for (psf = pmc->mca_sources; psf; psf = psf->sf_next)
2215 			psf->sf_crcount = 0;
2216 		mld_ifc_event(pmc->idev);
2217 	} else if (sf_setstate(pmc) || changerec)
2218 		mld_ifc_event(pmc->idev);
2219 	spin_unlock_bh(&pmc->mca_lock);
2220 	read_unlock_bh(&idev->lock);
2221 	return err;
2222 }
2223 
2224 /*
2225  * Add multicast single-source filter to the interface list
2226  */
2227 static int ip6_mc_add1_src(struct ifmcaddr6 *pmc, int sfmode,
2228 	const struct in6_addr *psfsrc)
2229 {
2230 	struct ip6_sf_list *psf, *psf_prev;
2231 
2232 	psf_prev = NULL;
2233 	for (psf = pmc->mca_sources; psf; psf = psf->sf_next) {
2234 		if (ipv6_addr_equal(&psf->sf_addr, psfsrc))
2235 			break;
2236 		psf_prev = psf;
2237 	}
2238 	if (!psf) {
2239 		psf = kzalloc(sizeof(*psf), GFP_ATOMIC);
2240 		if (!psf)
2241 			return -ENOBUFS;
2242 
2243 		psf->sf_addr = *psfsrc;
2244 		if (psf_prev) {
2245 			psf_prev->sf_next = psf;
2246 		} else
2247 			pmc->mca_sources = psf;
2248 	}
2249 	psf->sf_count[sfmode]++;
2250 	return 0;
2251 }
2252 
2253 static void sf_markstate(struct ifmcaddr6 *pmc)
2254 {
2255 	struct ip6_sf_list *psf;
2256 	int mca_xcount = pmc->mca_sfcount[MCAST_EXCLUDE];
2257 
2258 	for (psf = pmc->mca_sources; psf; psf = psf->sf_next)
2259 		if (pmc->mca_sfcount[MCAST_EXCLUDE]) {
2260 			psf->sf_oldin = mca_xcount ==
2261 				psf->sf_count[MCAST_EXCLUDE] &&
2262 				!psf->sf_count[MCAST_INCLUDE];
2263 		} else
2264 			psf->sf_oldin = psf->sf_count[MCAST_INCLUDE] != 0;
2265 }
2266 
2267 static int sf_setstate(struct ifmcaddr6 *pmc)
2268 {
2269 	struct ip6_sf_list *psf, *dpsf;
2270 	int mca_xcount = pmc->mca_sfcount[MCAST_EXCLUDE];
2271 	int qrv = pmc->idev->mc_qrv;
2272 	int new_in, rv;
2273 
2274 	rv = 0;
2275 	for (psf = pmc->mca_sources; psf; psf = psf->sf_next) {
2276 		if (pmc->mca_sfcount[MCAST_EXCLUDE]) {
2277 			new_in = mca_xcount == psf->sf_count[MCAST_EXCLUDE] &&
2278 				!psf->sf_count[MCAST_INCLUDE];
2279 		} else
2280 			new_in = psf->sf_count[MCAST_INCLUDE] != 0;
2281 		if (new_in) {
2282 			if (!psf->sf_oldin) {
2283 				struct ip6_sf_list *prev = NULL;
2284 
2285 				for (dpsf = pmc->mca_tomb; dpsf;
2286 				     dpsf = dpsf->sf_next) {
2287 					if (ipv6_addr_equal(&dpsf->sf_addr,
2288 					    &psf->sf_addr))
2289 						break;
2290 					prev = dpsf;
2291 				}
2292 				if (dpsf) {
2293 					if (prev)
2294 						prev->sf_next = dpsf->sf_next;
2295 					else
2296 						pmc->mca_tomb = dpsf->sf_next;
2297 					kfree(dpsf);
2298 				}
2299 				psf->sf_crcount = qrv;
2300 				rv++;
2301 			}
2302 		} else if (psf->sf_oldin) {
2303 			psf->sf_crcount = 0;
2304 			/*
2305 			 * add or update "delete" records if an active filter
2306 			 * is now inactive
2307 			 */
2308 			for (dpsf = pmc->mca_tomb; dpsf; dpsf = dpsf->sf_next)
2309 				if (ipv6_addr_equal(&dpsf->sf_addr,
2310 				    &psf->sf_addr))
2311 					break;
2312 			if (!dpsf) {
2313 				dpsf = kmalloc(sizeof(*dpsf), GFP_ATOMIC);
2314 				if (!dpsf)
2315 					continue;
2316 				*dpsf = *psf;
2317 				/* pmc->mca_lock held by callers */
2318 				dpsf->sf_next = pmc->mca_tomb;
2319 				pmc->mca_tomb = dpsf;
2320 			}
2321 			dpsf->sf_crcount = qrv;
2322 			rv++;
2323 		}
2324 	}
2325 	return rv;
2326 }
2327 
2328 /*
2329  * Add multicast source filter list to the interface list
2330  */
2331 static int ip6_mc_add_src(struct inet6_dev *idev, const struct in6_addr *pmca,
2332 			  int sfmode, int sfcount, const struct in6_addr *psfsrc,
2333 			  int delta)
2334 {
2335 	struct ifmcaddr6 *pmc;
2336 	int	isexclude;
2337 	int	i, err;
2338 
2339 	if (!idev)
2340 		return -ENODEV;
2341 	read_lock_bh(&idev->lock);
2342 	for (pmc = idev->mc_list; pmc; pmc = pmc->next) {
2343 		if (ipv6_addr_equal(pmca, &pmc->mca_addr))
2344 			break;
2345 	}
2346 	if (!pmc) {
2347 		/* MCA not found?? bug */
2348 		read_unlock_bh(&idev->lock);
2349 		return -ESRCH;
2350 	}
2351 	spin_lock_bh(&pmc->mca_lock);
2352 
2353 	sf_markstate(pmc);
2354 	isexclude = pmc->mca_sfmode == MCAST_EXCLUDE;
2355 	if (!delta)
2356 		pmc->mca_sfcount[sfmode]++;
2357 	err = 0;
2358 	for (i = 0; i < sfcount; i++) {
2359 		err = ip6_mc_add1_src(pmc, sfmode, &psfsrc[i]);
2360 		if (err)
2361 			break;
2362 	}
2363 	if (err) {
2364 		int j;
2365 
2366 		if (!delta)
2367 			pmc->mca_sfcount[sfmode]--;
2368 		for (j = 0; j < i; j++)
2369 			ip6_mc_del1_src(pmc, sfmode, &psfsrc[j]);
2370 	} else if (isexclude != (pmc->mca_sfcount[MCAST_EXCLUDE] != 0)) {
2371 		struct ip6_sf_list *psf;
2372 
2373 		/* filter mode change */
2374 		if (pmc->mca_sfcount[MCAST_EXCLUDE])
2375 			pmc->mca_sfmode = MCAST_EXCLUDE;
2376 		else if (pmc->mca_sfcount[MCAST_INCLUDE])
2377 			pmc->mca_sfmode = MCAST_INCLUDE;
2378 		/* else no filters; keep old mode for reports */
2379 
2380 		pmc->mca_crcount = idev->mc_qrv;
2381 		idev->mc_ifc_count = pmc->mca_crcount;
2382 		for (psf = pmc->mca_sources; psf; psf = psf->sf_next)
2383 			psf->sf_crcount = 0;
2384 		mld_ifc_event(idev);
2385 	} else if (sf_setstate(pmc))
2386 		mld_ifc_event(idev);
2387 	spin_unlock_bh(&pmc->mca_lock);
2388 	read_unlock_bh(&idev->lock);
2389 	return err;
2390 }
2391 
2392 static void ip6_mc_clear_src(struct ifmcaddr6 *pmc)
2393 {
2394 	struct ip6_sf_list *psf, *nextpsf;
2395 
2396 	for (psf = pmc->mca_tomb; psf; psf = nextpsf) {
2397 		nextpsf = psf->sf_next;
2398 		kfree(psf);
2399 	}
2400 	pmc->mca_tomb = NULL;
2401 	for (psf = pmc->mca_sources; psf; psf = nextpsf) {
2402 		nextpsf = psf->sf_next;
2403 		kfree(psf);
2404 	}
2405 	pmc->mca_sources = NULL;
2406 	pmc->mca_sfmode = MCAST_EXCLUDE;
2407 	pmc->mca_sfcount[MCAST_INCLUDE] = 0;
2408 	pmc->mca_sfcount[MCAST_EXCLUDE] = 1;
2409 }
2410 
2411 
2412 static void igmp6_join_group(struct ifmcaddr6 *ma)
2413 {
2414 	unsigned long delay;
2415 
2416 	if (ma->mca_flags & MAF_NOREPORT)
2417 		return;
2418 
2419 	igmp6_send(&ma->mca_addr, ma->idev->dev, ICMPV6_MGM_REPORT);
2420 
2421 	delay = prandom_u32() % unsolicited_report_interval(ma->idev);
2422 
2423 	spin_lock_bh(&ma->mca_lock);
2424 	if (del_timer(&ma->mca_timer)) {
2425 		refcount_dec(&ma->mca_refcnt);
2426 		delay = ma->mca_timer.expires - jiffies;
2427 	}
2428 
2429 	if (!mod_timer(&ma->mca_timer, jiffies + delay))
2430 		refcount_inc(&ma->mca_refcnt);
2431 	ma->mca_flags |= MAF_TIMER_RUNNING | MAF_LAST_REPORTER;
2432 	spin_unlock_bh(&ma->mca_lock);
2433 }
2434 
2435 static int ip6_mc_leave_src(struct sock *sk, struct ipv6_mc_socklist *iml,
2436 			    struct inet6_dev *idev)
2437 {
2438 	int err;
2439 
2440 	/* callers have the socket lock and rtnl lock
2441 	 * so no other readers or writers of iml or its sflist
2442 	 */
2443 	if (!iml->sflist) {
2444 		/* any-source empty exclude case */
2445 		return ip6_mc_del_src(idev, &iml->addr, iml->sfmode, 0, NULL, 0);
2446 	}
2447 	err = ip6_mc_del_src(idev, &iml->addr, iml->sfmode,
2448 		iml->sflist->sl_count, iml->sflist->sl_addr, 0);
2449 	sock_kfree_s(sk, iml->sflist, IP6_SFLSIZE(iml->sflist->sl_max));
2450 	iml->sflist = NULL;
2451 	return err;
2452 }
2453 
2454 static void igmp6_leave_group(struct ifmcaddr6 *ma)
2455 {
2456 	if (mld_in_v1_mode(ma->idev)) {
2457 		if (ma->mca_flags & MAF_LAST_REPORTER)
2458 			igmp6_send(&ma->mca_addr, ma->idev->dev,
2459 				ICMPV6_MGM_REDUCTION);
2460 	} else {
2461 		mld_add_delrec(ma->idev, ma);
2462 		mld_ifc_event(ma->idev);
2463 	}
2464 }
2465 
2466 static void mld_gq_timer_expire(struct timer_list *t)
2467 {
2468 	struct inet6_dev *idev = from_timer(idev, t, mc_gq_timer);
2469 
2470 	idev->mc_gq_running = 0;
2471 	mld_send_report(idev, NULL);
2472 	in6_dev_put(idev);
2473 }
2474 
2475 static void mld_ifc_timer_expire(struct timer_list *t)
2476 {
2477 	struct inet6_dev *idev = from_timer(idev, t, mc_ifc_timer);
2478 
2479 	mld_send_cr(idev);
2480 	if (idev->mc_ifc_count) {
2481 		idev->mc_ifc_count--;
2482 		if (idev->mc_ifc_count)
2483 			mld_ifc_start_timer(idev,
2484 					    unsolicited_report_interval(idev));
2485 	}
2486 	in6_dev_put(idev);
2487 }
2488 
2489 static void mld_ifc_event(struct inet6_dev *idev)
2490 {
2491 	if (mld_in_v1_mode(idev))
2492 		return;
2493 	idev->mc_ifc_count = idev->mc_qrv;
2494 	mld_ifc_start_timer(idev, 1);
2495 }
2496 
2497 static void igmp6_timer_handler(struct timer_list *t)
2498 {
2499 	struct ifmcaddr6 *ma = from_timer(ma, t, mca_timer);
2500 
2501 	if (mld_in_v1_mode(ma->idev))
2502 		igmp6_send(&ma->mca_addr, ma->idev->dev, ICMPV6_MGM_REPORT);
2503 	else
2504 		mld_send_report(ma->idev, ma);
2505 
2506 	spin_lock(&ma->mca_lock);
2507 	ma->mca_flags |=  MAF_LAST_REPORTER;
2508 	ma->mca_flags &= ~MAF_TIMER_RUNNING;
2509 	spin_unlock(&ma->mca_lock);
2510 	ma_put(ma);
2511 }
2512 
2513 /* Device changing type */
2514 
2515 void ipv6_mc_unmap(struct inet6_dev *idev)
2516 {
2517 	struct ifmcaddr6 *i;
2518 
2519 	/* Install multicast list, except for all-nodes (already installed) */
2520 
2521 	read_lock_bh(&idev->lock);
2522 	for (i = idev->mc_list; i; i = i->next)
2523 		igmp6_group_dropped(i);
2524 	read_unlock_bh(&idev->lock);
2525 }
2526 
2527 void ipv6_mc_remap(struct inet6_dev *idev)
2528 {
2529 	ipv6_mc_up(idev);
2530 }
2531 
2532 /* Device going down */
2533 
2534 void ipv6_mc_down(struct inet6_dev *idev)
2535 {
2536 	struct ifmcaddr6 *i;
2537 
2538 	/* Withdraw multicast list */
2539 
2540 	read_lock_bh(&idev->lock);
2541 
2542 	for (i = idev->mc_list; i; i = i->next)
2543 		igmp6_group_dropped(i);
2544 
2545 	/* Should stop timer after group drop. or we will
2546 	 * start timer again in mld_ifc_event()
2547 	 */
2548 	mld_ifc_stop_timer(idev);
2549 	mld_gq_stop_timer(idev);
2550 	mld_dad_stop_timer(idev);
2551 	read_unlock_bh(&idev->lock);
2552 }
2553 
2554 static void ipv6_mc_reset(struct inet6_dev *idev)
2555 {
2556 	idev->mc_qrv = sysctl_mld_qrv;
2557 	idev->mc_qi = MLD_QI_DEFAULT;
2558 	idev->mc_qri = MLD_QRI_DEFAULT;
2559 	idev->mc_v1_seen = 0;
2560 	idev->mc_maxdelay = unsolicited_report_interval(idev);
2561 }
2562 
2563 /* Device going up */
2564 
2565 void ipv6_mc_up(struct inet6_dev *idev)
2566 {
2567 	struct ifmcaddr6 *i;
2568 
2569 	/* Install multicast list, except for all-nodes (already installed) */
2570 
2571 	read_lock_bh(&idev->lock);
2572 	ipv6_mc_reset(idev);
2573 	for (i = idev->mc_list; i; i = i->next) {
2574 		mld_del_delrec(idev, i);
2575 		igmp6_group_added(i, i->mca_sfmode);
2576 	}
2577 	read_unlock_bh(&idev->lock);
2578 }
2579 
2580 /* IPv6 device initialization. */
2581 
2582 void ipv6_mc_init_dev(struct inet6_dev *idev)
2583 {
2584 	write_lock_bh(&idev->lock);
2585 	spin_lock_init(&idev->mc_lock);
2586 	idev->mc_gq_running = 0;
2587 	timer_setup(&idev->mc_gq_timer, mld_gq_timer_expire, 0);
2588 	idev->mc_tomb = NULL;
2589 	idev->mc_ifc_count = 0;
2590 	timer_setup(&idev->mc_ifc_timer, mld_ifc_timer_expire, 0);
2591 	timer_setup(&idev->mc_dad_timer, mld_dad_timer_expire, 0);
2592 	ipv6_mc_reset(idev);
2593 	write_unlock_bh(&idev->lock);
2594 }
2595 
2596 /*
2597  *	Device is about to be destroyed: clean up.
2598  */
2599 
2600 void ipv6_mc_destroy_dev(struct inet6_dev *idev)
2601 {
2602 	struct ifmcaddr6 *i;
2603 
2604 	/* Deactivate timers */
2605 	ipv6_mc_down(idev);
2606 	mld_clear_delrec(idev);
2607 
2608 	/* Delete all-nodes address. */
2609 	/* We cannot call ipv6_dev_mc_dec() directly, our caller in
2610 	 * addrconf.c has NULL'd out dev->ip6_ptr so in6_dev_get() will
2611 	 * fail.
2612 	 */
2613 	__ipv6_dev_mc_dec(idev, &in6addr_linklocal_allnodes);
2614 
2615 	if (idev->cnf.forwarding)
2616 		__ipv6_dev_mc_dec(idev, &in6addr_linklocal_allrouters);
2617 
2618 	write_lock_bh(&idev->lock);
2619 	while ((i = idev->mc_list) != NULL) {
2620 		idev->mc_list = i->next;
2621 
2622 		write_unlock_bh(&idev->lock);
2623 		ma_put(i);
2624 		write_lock_bh(&idev->lock);
2625 	}
2626 	write_unlock_bh(&idev->lock);
2627 }
2628 
2629 static void ipv6_mc_rejoin_groups(struct inet6_dev *idev)
2630 {
2631 	struct ifmcaddr6 *pmc;
2632 
2633 	ASSERT_RTNL();
2634 
2635 	if (mld_in_v1_mode(idev)) {
2636 		read_lock_bh(&idev->lock);
2637 		for (pmc = idev->mc_list; pmc; pmc = pmc->next)
2638 			igmp6_join_group(pmc);
2639 		read_unlock_bh(&idev->lock);
2640 	} else
2641 		mld_send_report(idev, NULL);
2642 }
2643 
2644 static int ipv6_mc_netdev_event(struct notifier_block *this,
2645 				unsigned long event,
2646 				void *ptr)
2647 {
2648 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
2649 	struct inet6_dev *idev = __in6_dev_get(dev);
2650 
2651 	switch (event) {
2652 	case NETDEV_RESEND_IGMP:
2653 		if (idev)
2654 			ipv6_mc_rejoin_groups(idev);
2655 		break;
2656 	default:
2657 		break;
2658 	}
2659 
2660 	return NOTIFY_DONE;
2661 }
2662 
2663 static struct notifier_block igmp6_netdev_notifier = {
2664 	.notifier_call = ipv6_mc_netdev_event,
2665 };
2666 
2667 #ifdef CONFIG_PROC_FS
2668 struct igmp6_mc_iter_state {
2669 	struct seq_net_private p;
2670 	struct net_device *dev;
2671 	struct inet6_dev *idev;
2672 };
2673 
2674 #define igmp6_mc_seq_private(seq)	((struct igmp6_mc_iter_state *)(seq)->private)
2675 
2676 static inline struct ifmcaddr6 *igmp6_mc_get_first(struct seq_file *seq)
2677 {
2678 	struct ifmcaddr6 *im = NULL;
2679 	struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq);
2680 	struct net *net = seq_file_net(seq);
2681 
2682 	state->idev = NULL;
2683 	for_each_netdev_rcu(net, state->dev) {
2684 		struct inet6_dev *idev;
2685 		idev = __in6_dev_get(state->dev);
2686 		if (!idev)
2687 			continue;
2688 		read_lock_bh(&idev->lock);
2689 		im = idev->mc_list;
2690 		if (im) {
2691 			state->idev = idev;
2692 			break;
2693 		}
2694 		read_unlock_bh(&idev->lock);
2695 	}
2696 	return im;
2697 }
2698 
2699 static struct ifmcaddr6 *igmp6_mc_get_next(struct seq_file *seq, struct ifmcaddr6 *im)
2700 {
2701 	struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq);
2702 
2703 	im = im->next;
2704 	while (!im) {
2705 		if (likely(state->idev))
2706 			read_unlock_bh(&state->idev->lock);
2707 
2708 		state->dev = next_net_device_rcu(state->dev);
2709 		if (!state->dev) {
2710 			state->idev = NULL;
2711 			break;
2712 		}
2713 		state->idev = __in6_dev_get(state->dev);
2714 		if (!state->idev)
2715 			continue;
2716 		read_lock_bh(&state->idev->lock);
2717 		im = state->idev->mc_list;
2718 	}
2719 	return im;
2720 }
2721 
2722 static struct ifmcaddr6 *igmp6_mc_get_idx(struct seq_file *seq, loff_t pos)
2723 {
2724 	struct ifmcaddr6 *im = igmp6_mc_get_first(seq);
2725 	if (im)
2726 		while (pos && (im = igmp6_mc_get_next(seq, im)) != NULL)
2727 			--pos;
2728 	return pos ? NULL : im;
2729 }
2730 
2731 static void *igmp6_mc_seq_start(struct seq_file *seq, loff_t *pos)
2732 	__acquires(RCU)
2733 {
2734 	rcu_read_lock();
2735 	return igmp6_mc_get_idx(seq, *pos);
2736 }
2737 
2738 static void *igmp6_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2739 {
2740 	struct ifmcaddr6 *im = igmp6_mc_get_next(seq, v);
2741 
2742 	++*pos;
2743 	return im;
2744 }
2745 
2746 static void igmp6_mc_seq_stop(struct seq_file *seq, void *v)
2747 	__releases(RCU)
2748 {
2749 	struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq);
2750 
2751 	if (likely(state->idev)) {
2752 		read_unlock_bh(&state->idev->lock);
2753 		state->idev = NULL;
2754 	}
2755 	state->dev = NULL;
2756 	rcu_read_unlock();
2757 }
2758 
2759 static int igmp6_mc_seq_show(struct seq_file *seq, void *v)
2760 {
2761 	struct ifmcaddr6 *im = (struct ifmcaddr6 *)v;
2762 	struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq);
2763 
2764 	seq_printf(seq,
2765 		   "%-4d %-15s %pi6 %5d %08X %ld\n",
2766 		   state->dev->ifindex, state->dev->name,
2767 		   &im->mca_addr,
2768 		   im->mca_users, im->mca_flags,
2769 		   (im->mca_flags&MAF_TIMER_RUNNING) ?
2770 		   jiffies_to_clock_t(im->mca_timer.expires-jiffies) : 0);
2771 	return 0;
2772 }
2773 
2774 static const struct seq_operations igmp6_mc_seq_ops = {
2775 	.start	=	igmp6_mc_seq_start,
2776 	.next	=	igmp6_mc_seq_next,
2777 	.stop	=	igmp6_mc_seq_stop,
2778 	.show	=	igmp6_mc_seq_show,
2779 };
2780 
2781 struct igmp6_mcf_iter_state {
2782 	struct seq_net_private p;
2783 	struct net_device *dev;
2784 	struct inet6_dev *idev;
2785 	struct ifmcaddr6 *im;
2786 };
2787 
2788 #define igmp6_mcf_seq_private(seq)	((struct igmp6_mcf_iter_state *)(seq)->private)
2789 
2790 static inline struct ip6_sf_list *igmp6_mcf_get_first(struct seq_file *seq)
2791 {
2792 	struct ip6_sf_list *psf = NULL;
2793 	struct ifmcaddr6 *im = NULL;
2794 	struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);
2795 	struct net *net = seq_file_net(seq);
2796 
2797 	state->idev = NULL;
2798 	state->im = NULL;
2799 	for_each_netdev_rcu(net, state->dev) {
2800 		struct inet6_dev *idev;
2801 		idev = __in6_dev_get(state->dev);
2802 		if (unlikely(idev == NULL))
2803 			continue;
2804 		read_lock_bh(&idev->lock);
2805 		im = idev->mc_list;
2806 		if (likely(im)) {
2807 			spin_lock_bh(&im->mca_lock);
2808 			psf = im->mca_sources;
2809 			if (likely(psf)) {
2810 				state->im = im;
2811 				state->idev = idev;
2812 				break;
2813 			}
2814 			spin_unlock_bh(&im->mca_lock);
2815 		}
2816 		read_unlock_bh(&idev->lock);
2817 	}
2818 	return psf;
2819 }
2820 
2821 static struct ip6_sf_list *igmp6_mcf_get_next(struct seq_file *seq, struct ip6_sf_list *psf)
2822 {
2823 	struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);
2824 
2825 	psf = psf->sf_next;
2826 	while (!psf) {
2827 		spin_unlock_bh(&state->im->mca_lock);
2828 		state->im = state->im->next;
2829 		while (!state->im) {
2830 			if (likely(state->idev))
2831 				read_unlock_bh(&state->idev->lock);
2832 
2833 			state->dev = next_net_device_rcu(state->dev);
2834 			if (!state->dev) {
2835 				state->idev = NULL;
2836 				goto out;
2837 			}
2838 			state->idev = __in6_dev_get(state->dev);
2839 			if (!state->idev)
2840 				continue;
2841 			read_lock_bh(&state->idev->lock);
2842 			state->im = state->idev->mc_list;
2843 		}
2844 		if (!state->im)
2845 			break;
2846 		spin_lock_bh(&state->im->mca_lock);
2847 		psf = state->im->mca_sources;
2848 	}
2849 out:
2850 	return psf;
2851 }
2852 
2853 static struct ip6_sf_list *igmp6_mcf_get_idx(struct seq_file *seq, loff_t pos)
2854 {
2855 	struct ip6_sf_list *psf = igmp6_mcf_get_first(seq);
2856 	if (psf)
2857 		while (pos && (psf = igmp6_mcf_get_next(seq, psf)) != NULL)
2858 			--pos;
2859 	return pos ? NULL : psf;
2860 }
2861 
2862 static void *igmp6_mcf_seq_start(struct seq_file *seq, loff_t *pos)
2863 	__acquires(RCU)
2864 {
2865 	rcu_read_lock();
2866 	return *pos ? igmp6_mcf_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2867 }
2868 
2869 static void *igmp6_mcf_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2870 {
2871 	struct ip6_sf_list *psf;
2872 	if (v == SEQ_START_TOKEN)
2873 		psf = igmp6_mcf_get_first(seq);
2874 	else
2875 		psf = igmp6_mcf_get_next(seq, v);
2876 	++*pos;
2877 	return psf;
2878 }
2879 
2880 static void igmp6_mcf_seq_stop(struct seq_file *seq, void *v)
2881 	__releases(RCU)
2882 {
2883 	struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);
2884 	if (likely(state->im)) {
2885 		spin_unlock_bh(&state->im->mca_lock);
2886 		state->im = NULL;
2887 	}
2888 	if (likely(state->idev)) {
2889 		read_unlock_bh(&state->idev->lock);
2890 		state->idev = NULL;
2891 	}
2892 	state->dev = NULL;
2893 	rcu_read_unlock();
2894 }
2895 
2896 static int igmp6_mcf_seq_show(struct seq_file *seq, void *v)
2897 {
2898 	struct ip6_sf_list *psf = (struct ip6_sf_list *)v;
2899 	struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);
2900 
2901 	if (v == SEQ_START_TOKEN) {
2902 		seq_puts(seq, "Idx Device                Multicast Address                   Source Address    INC    EXC\n");
2903 	} else {
2904 		seq_printf(seq,
2905 			   "%3d %6.6s %pi6 %pi6 %6lu %6lu\n",
2906 			   state->dev->ifindex, state->dev->name,
2907 			   &state->im->mca_addr,
2908 			   &psf->sf_addr,
2909 			   psf->sf_count[MCAST_INCLUDE],
2910 			   psf->sf_count[MCAST_EXCLUDE]);
2911 	}
2912 	return 0;
2913 }
2914 
2915 static const struct seq_operations igmp6_mcf_seq_ops = {
2916 	.start	=	igmp6_mcf_seq_start,
2917 	.next	=	igmp6_mcf_seq_next,
2918 	.stop	=	igmp6_mcf_seq_stop,
2919 	.show	=	igmp6_mcf_seq_show,
2920 };
2921 
2922 static int __net_init igmp6_proc_init(struct net *net)
2923 {
2924 	int err;
2925 
2926 	err = -ENOMEM;
2927 	if (!proc_create_net("igmp6", 0444, net->proc_net, &igmp6_mc_seq_ops,
2928 			sizeof(struct igmp6_mc_iter_state)))
2929 		goto out;
2930 	if (!proc_create_net("mcfilter6", 0444, net->proc_net,
2931 			&igmp6_mcf_seq_ops,
2932 			sizeof(struct igmp6_mcf_iter_state)))
2933 		goto out_proc_net_igmp6;
2934 
2935 	err = 0;
2936 out:
2937 	return err;
2938 
2939 out_proc_net_igmp6:
2940 	remove_proc_entry("igmp6", net->proc_net);
2941 	goto out;
2942 }
2943 
2944 static void __net_exit igmp6_proc_exit(struct net *net)
2945 {
2946 	remove_proc_entry("mcfilter6", net->proc_net);
2947 	remove_proc_entry("igmp6", net->proc_net);
2948 }
2949 #else
2950 static inline int igmp6_proc_init(struct net *net)
2951 {
2952 	return 0;
2953 }
2954 static inline void igmp6_proc_exit(struct net *net)
2955 {
2956 }
2957 #endif
2958 
2959 static int __net_init igmp6_net_init(struct net *net)
2960 {
2961 	int err;
2962 
2963 	err = inet_ctl_sock_create(&net->ipv6.igmp_sk, PF_INET6,
2964 				   SOCK_RAW, IPPROTO_ICMPV6, net);
2965 	if (err < 0) {
2966 		pr_err("Failed to initialize the IGMP6 control socket (err %d)\n",
2967 		       err);
2968 		goto out;
2969 	}
2970 
2971 	inet6_sk(net->ipv6.igmp_sk)->hop_limit = 1;
2972 
2973 	err = inet_ctl_sock_create(&net->ipv6.mc_autojoin_sk, PF_INET6,
2974 				   SOCK_RAW, IPPROTO_ICMPV6, net);
2975 	if (err < 0) {
2976 		pr_err("Failed to initialize the IGMP6 autojoin socket (err %d)\n",
2977 		       err);
2978 		goto out_sock_create;
2979 	}
2980 
2981 	err = igmp6_proc_init(net);
2982 	if (err)
2983 		goto out_sock_create_autojoin;
2984 
2985 	return 0;
2986 
2987 out_sock_create_autojoin:
2988 	inet_ctl_sock_destroy(net->ipv6.mc_autojoin_sk);
2989 out_sock_create:
2990 	inet_ctl_sock_destroy(net->ipv6.igmp_sk);
2991 out:
2992 	return err;
2993 }
2994 
2995 static void __net_exit igmp6_net_exit(struct net *net)
2996 {
2997 	inet_ctl_sock_destroy(net->ipv6.igmp_sk);
2998 	inet_ctl_sock_destroy(net->ipv6.mc_autojoin_sk);
2999 	igmp6_proc_exit(net);
3000 }
3001 
3002 static struct pernet_operations igmp6_net_ops = {
3003 	.init = igmp6_net_init,
3004 	.exit = igmp6_net_exit,
3005 };
3006 
3007 int __init igmp6_init(void)
3008 {
3009 	return register_pernet_subsys(&igmp6_net_ops);
3010 }
3011 
3012 int __init igmp6_late_init(void)
3013 {
3014 	return register_netdevice_notifier(&igmp6_netdev_notifier);
3015 }
3016 
3017 void igmp6_cleanup(void)
3018 {
3019 	unregister_pernet_subsys(&igmp6_net_ops);
3020 }
3021 
3022 void igmp6_late_cleanup(void)
3023 {
3024 	unregister_netdevice_notifier(&igmp6_netdev_notifier);
3025 }
3026