xref: /openbmc/linux/net/ipv6/mcast.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	Multicast support for IPv6
4  *	Linux INET6 implementation
5  *
6  *	Authors:
7  *	Pedro Roque		<roque@di.fc.ul.pt>
8  *
9  *	Based on linux/ipv4/igmp.c and linux/ipv4/ip_sockglue.c
10  */
11 
12 /* Changes:
13  *
14  *	yoshfuji	: fix format of router-alert option
15  *	YOSHIFUJI Hideaki @USAGI:
16  *		Fixed source address for MLD message based on
17  *		<draft-ietf-magma-mld-source-05.txt>.
18  *	YOSHIFUJI Hideaki @USAGI:
19  *		- Ignore Queries for invalid addresses.
20  *		- MLD for link-local addresses.
21  *	David L Stevens <dlstevens@us.ibm.com>:
22  *		- MLDv2 support
23  */
24 
25 #include <linux/module.h>
26 #include <linux/errno.h>
27 #include <linux/types.h>
28 #include <linux/string.h>
29 #include <linux/socket.h>
30 #include <linux/sockios.h>
31 #include <linux/jiffies.h>
32 #include <linux/times.h>
33 #include <linux/net.h>
34 #include <linux/in.h>
35 #include <linux/in6.h>
36 #include <linux/netdevice.h>
37 #include <linux/if_arp.h>
38 #include <linux/route.h>
39 #include <linux/init.h>
40 #include <linux/proc_fs.h>
41 #include <linux/seq_file.h>
42 #include <linux/slab.h>
43 #include <linux/pkt_sched.h>
44 #include <net/mld.h>
45 
46 #include <linux/netfilter.h>
47 #include <linux/netfilter_ipv6.h>
48 
49 #include <net/net_namespace.h>
50 #include <net/sock.h>
51 #include <net/snmp.h>
52 
53 #include <net/ipv6.h>
54 #include <net/protocol.h>
55 #include <net/if_inet6.h>
56 #include <net/ndisc.h>
57 #include <net/addrconf.h>
58 #include <net/ip6_route.h>
59 #include <net/inet_common.h>
60 
61 #include <net/ip6_checksum.h>
62 
63 /* Ensure that we have struct in6_addr aligned on 32bit word. */
64 static int __mld2_query_bugs[] __attribute__((__unused__)) = {
65 	BUILD_BUG_ON_ZERO(offsetof(struct mld2_query, mld2q_srcs) % 4),
66 	BUILD_BUG_ON_ZERO(offsetof(struct mld2_report, mld2r_grec) % 4),
67 	BUILD_BUG_ON_ZERO(offsetof(struct mld2_grec, grec_mca) % 4)
68 };
69 
70 static struct in6_addr mld2_all_mcr = MLD2_ALL_MCR_INIT;
71 
72 static void igmp6_join_group(struct ifmcaddr6 *ma);
73 static void igmp6_leave_group(struct ifmcaddr6 *ma);
74 static void igmp6_timer_handler(struct timer_list *t);
75 
76 static void mld_gq_timer_expire(struct timer_list *t);
77 static void mld_ifc_timer_expire(struct timer_list *t);
78 static void mld_ifc_event(struct inet6_dev *idev);
79 static void mld_add_delrec(struct inet6_dev *idev, struct ifmcaddr6 *pmc);
80 static void mld_del_delrec(struct inet6_dev *idev, struct ifmcaddr6 *pmc);
81 static void mld_clear_delrec(struct inet6_dev *idev);
82 static bool mld_in_v1_mode(const struct inet6_dev *idev);
83 static int sf_setstate(struct ifmcaddr6 *pmc);
84 static void sf_markstate(struct ifmcaddr6 *pmc);
85 static void ip6_mc_clear_src(struct ifmcaddr6 *pmc);
86 static int ip6_mc_del_src(struct inet6_dev *idev, const struct in6_addr *pmca,
87 			  int sfmode, int sfcount, const struct in6_addr *psfsrc,
88 			  int delta);
89 static int ip6_mc_add_src(struct inet6_dev *idev, const struct in6_addr *pmca,
90 			  int sfmode, int sfcount, const struct in6_addr *psfsrc,
91 			  int delta);
92 static int ip6_mc_leave_src(struct sock *sk, struct ipv6_mc_socklist *iml,
93 			    struct inet6_dev *idev);
94 static int __ipv6_dev_mc_inc(struct net_device *dev,
95 			     const struct in6_addr *addr, unsigned int mode);
96 
97 #define MLD_QRV_DEFAULT		2
98 /* RFC3810, 9.2. Query Interval */
99 #define MLD_QI_DEFAULT		(125 * HZ)
100 /* RFC3810, 9.3. Query Response Interval */
101 #define MLD_QRI_DEFAULT		(10 * HZ)
102 
103 /* RFC3810, 8.1 Query Version Distinctions */
104 #define MLD_V1_QUERY_LEN	24
105 #define MLD_V2_QUERY_LEN_MIN	28
106 
107 #define IPV6_MLD_MAX_MSF	64
108 
109 int sysctl_mld_max_msf __read_mostly = IPV6_MLD_MAX_MSF;
110 int sysctl_mld_qrv __read_mostly = MLD_QRV_DEFAULT;
111 
112 /*
113  *	socket join on multicast group
114  */
115 
116 #define for_each_pmc_rcu(np, pmc)				\
117 	for (pmc = rcu_dereference(np->ipv6_mc_list);		\
118 	     pmc != NULL;					\
119 	     pmc = rcu_dereference(pmc->next))
120 
121 static int unsolicited_report_interval(struct inet6_dev *idev)
122 {
123 	int iv;
124 
125 	if (mld_in_v1_mode(idev))
126 		iv = idev->cnf.mldv1_unsolicited_report_interval;
127 	else
128 		iv = idev->cnf.mldv2_unsolicited_report_interval;
129 
130 	return iv > 0 ? iv : 1;
131 }
132 
133 static int __ipv6_sock_mc_join(struct sock *sk, int ifindex,
134 			       const struct in6_addr *addr, unsigned int mode)
135 {
136 	struct net_device *dev = NULL;
137 	struct ipv6_mc_socklist *mc_lst;
138 	struct ipv6_pinfo *np = inet6_sk(sk);
139 	struct net *net = sock_net(sk);
140 	int err;
141 
142 	ASSERT_RTNL();
143 
144 	if (!ipv6_addr_is_multicast(addr))
145 		return -EINVAL;
146 
147 	rcu_read_lock();
148 	for_each_pmc_rcu(np, mc_lst) {
149 		if ((ifindex == 0 || mc_lst->ifindex == ifindex) &&
150 		    ipv6_addr_equal(&mc_lst->addr, addr)) {
151 			rcu_read_unlock();
152 			return -EADDRINUSE;
153 		}
154 	}
155 	rcu_read_unlock();
156 
157 	mc_lst = sock_kmalloc(sk, sizeof(struct ipv6_mc_socklist), GFP_KERNEL);
158 
159 	if (!mc_lst)
160 		return -ENOMEM;
161 
162 	mc_lst->next = NULL;
163 	mc_lst->addr = *addr;
164 
165 	if (ifindex == 0) {
166 		struct rt6_info *rt;
167 		rt = rt6_lookup(net, addr, NULL, 0, NULL, 0);
168 		if (rt) {
169 			dev = rt->dst.dev;
170 			ip6_rt_put(rt);
171 		}
172 	} else
173 		dev = __dev_get_by_index(net, ifindex);
174 
175 	if (!dev) {
176 		sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
177 		return -ENODEV;
178 	}
179 
180 	mc_lst->ifindex = dev->ifindex;
181 	mc_lst->sfmode = mode;
182 	rwlock_init(&mc_lst->sflock);
183 	mc_lst->sflist = NULL;
184 
185 	/*
186 	 *	now add/increase the group membership on the device
187 	 */
188 
189 	err = __ipv6_dev_mc_inc(dev, addr, mode);
190 
191 	if (err) {
192 		sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
193 		return err;
194 	}
195 
196 	mc_lst->next = np->ipv6_mc_list;
197 	rcu_assign_pointer(np->ipv6_mc_list, mc_lst);
198 
199 	return 0;
200 }
201 
202 int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
203 {
204 	return __ipv6_sock_mc_join(sk, ifindex, addr, MCAST_EXCLUDE);
205 }
206 EXPORT_SYMBOL(ipv6_sock_mc_join);
207 
208 int ipv6_sock_mc_join_ssm(struct sock *sk, int ifindex,
209 			  const struct in6_addr *addr, unsigned int mode)
210 {
211 	return __ipv6_sock_mc_join(sk, ifindex, addr, mode);
212 }
213 
214 /*
215  *	socket leave on multicast group
216  */
217 int ipv6_sock_mc_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
218 {
219 	struct ipv6_pinfo *np = inet6_sk(sk);
220 	struct ipv6_mc_socklist *mc_lst;
221 	struct ipv6_mc_socklist __rcu **lnk;
222 	struct net *net = sock_net(sk);
223 
224 	ASSERT_RTNL();
225 
226 	if (!ipv6_addr_is_multicast(addr))
227 		return -EINVAL;
228 
229 	for (lnk = &np->ipv6_mc_list;
230 	     (mc_lst = rtnl_dereference(*lnk)) != NULL;
231 	      lnk = &mc_lst->next) {
232 		if ((ifindex == 0 || mc_lst->ifindex == ifindex) &&
233 		    ipv6_addr_equal(&mc_lst->addr, addr)) {
234 			struct net_device *dev;
235 
236 			*lnk = mc_lst->next;
237 
238 			dev = __dev_get_by_index(net, mc_lst->ifindex);
239 			if (dev) {
240 				struct inet6_dev *idev = __in6_dev_get(dev);
241 
242 				(void) ip6_mc_leave_src(sk, mc_lst, idev);
243 				if (idev)
244 					__ipv6_dev_mc_dec(idev, &mc_lst->addr);
245 			} else
246 				(void) ip6_mc_leave_src(sk, mc_lst, NULL);
247 
248 			atomic_sub(sizeof(*mc_lst), &sk->sk_omem_alloc);
249 			kfree_rcu(mc_lst, rcu);
250 			return 0;
251 		}
252 	}
253 
254 	return -EADDRNOTAVAIL;
255 }
256 EXPORT_SYMBOL(ipv6_sock_mc_drop);
257 
258 /* called with rcu_read_lock() */
259 static struct inet6_dev *ip6_mc_find_dev_rcu(struct net *net,
260 					     const struct in6_addr *group,
261 					     int ifindex)
262 {
263 	struct net_device *dev = NULL;
264 	struct inet6_dev *idev = NULL;
265 
266 	if (ifindex == 0) {
267 		struct rt6_info *rt = rt6_lookup(net, group, NULL, 0, NULL, 0);
268 
269 		if (rt) {
270 			dev = rt->dst.dev;
271 			ip6_rt_put(rt);
272 		}
273 	} else
274 		dev = dev_get_by_index_rcu(net, ifindex);
275 
276 	if (!dev)
277 		return NULL;
278 	idev = __in6_dev_get(dev);
279 	if (!idev)
280 		return NULL;
281 	read_lock_bh(&idev->lock);
282 	if (idev->dead) {
283 		read_unlock_bh(&idev->lock);
284 		return NULL;
285 	}
286 	return idev;
287 }
288 
289 void __ipv6_sock_mc_close(struct sock *sk)
290 {
291 	struct ipv6_pinfo *np = inet6_sk(sk);
292 	struct ipv6_mc_socklist *mc_lst;
293 	struct net *net = sock_net(sk);
294 
295 	ASSERT_RTNL();
296 
297 	while ((mc_lst = rtnl_dereference(np->ipv6_mc_list)) != NULL) {
298 		struct net_device *dev;
299 
300 		np->ipv6_mc_list = mc_lst->next;
301 
302 		dev = __dev_get_by_index(net, mc_lst->ifindex);
303 		if (dev) {
304 			struct inet6_dev *idev = __in6_dev_get(dev);
305 
306 			(void) ip6_mc_leave_src(sk, mc_lst, idev);
307 			if (idev)
308 				__ipv6_dev_mc_dec(idev, &mc_lst->addr);
309 		} else
310 			(void) ip6_mc_leave_src(sk, mc_lst, NULL);
311 
312 		atomic_sub(sizeof(*mc_lst), &sk->sk_omem_alloc);
313 		kfree_rcu(mc_lst, rcu);
314 	}
315 }
316 
317 void ipv6_sock_mc_close(struct sock *sk)
318 {
319 	struct ipv6_pinfo *np = inet6_sk(sk);
320 
321 	if (!rcu_access_pointer(np->ipv6_mc_list))
322 		return;
323 	rtnl_lock();
324 	__ipv6_sock_mc_close(sk);
325 	rtnl_unlock();
326 }
327 
328 int ip6_mc_source(int add, int omode, struct sock *sk,
329 	struct group_source_req *pgsr)
330 {
331 	struct in6_addr *source, *group;
332 	struct ipv6_mc_socklist *pmc;
333 	struct inet6_dev *idev;
334 	struct ipv6_pinfo *inet6 = inet6_sk(sk);
335 	struct ip6_sf_socklist *psl;
336 	struct net *net = sock_net(sk);
337 	int i, j, rv;
338 	int leavegroup = 0;
339 	int pmclocked = 0;
340 	int err;
341 
342 	source = &((struct sockaddr_in6 *)&pgsr->gsr_source)->sin6_addr;
343 	group = &((struct sockaddr_in6 *)&pgsr->gsr_group)->sin6_addr;
344 
345 	if (!ipv6_addr_is_multicast(group))
346 		return -EINVAL;
347 
348 	rcu_read_lock();
349 	idev = ip6_mc_find_dev_rcu(net, group, pgsr->gsr_interface);
350 	if (!idev) {
351 		rcu_read_unlock();
352 		return -ENODEV;
353 	}
354 
355 	err = -EADDRNOTAVAIL;
356 
357 	for_each_pmc_rcu(inet6, pmc) {
358 		if (pgsr->gsr_interface && pmc->ifindex != pgsr->gsr_interface)
359 			continue;
360 		if (ipv6_addr_equal(&pmc->addr, group))
361 			break;
362 	}
363 	if (!pmc) {		/* must have a prior join */
364 		err = -EINVAL;
365 		goto done;
366 	}
367 	/* if a source filter was set, must be the same mode as before */
368 	if (pmc->sflist) {
369 		if (pmc->sfmode != omode) {
370 			err = -EINVAL;
371 			goto done;
372 		}
373 	} else if (pmc->sfmode != omode) {
374 		/* allow mode switches for empty-set filters */
375 		ip6_mc_add_src(idev, group, omode, 0, NULL, 0);
376 		ip6_mc_del_src(idev, group, pmc->sfmode, 0, NULL, 0);
377 		pmc->sfmode = omode;
378 	}
379 
380 	write_lock(&pmc->sflock);
381 	pmclocked = 1;
382 
383 	psl = pmc->sflist;
384 	if (!add) {
385 		if (!psl)
386 			goto done;	/* err = -EADDRNOTAVAIL */
387 		rv = !0;
388 		for (i = 0; i < psl->sl_count; i++) {
389 			rv = !ipv6_addr_equal(&psl->sl_addr[i], source);
390 			if (rv == 0)
391 				break;
392 		}
393 		if (rv)		/* source not found */
394 			goto done;	/* err = -EADDRNOTAVAIL */
395 
396 		/* special case - (INCLUDE, empty) == LEAVE_GROUP */
397 		if (psl->sl_count == 1 && omode == MCAST_INCLUDE) {
398 			leavegroup = 1;
399 			goto done;
400 		}
401 
402 		/* update the interface filter */
403 		ip6_mc_del_src(idev, group, omode, 1, source, 1);
404 
405 		for (j = i+1; j < psl->sl_count; j++)
406 			psl->sl_addr[j-1] = psl->sl_addr[j];
407 		psl->sl_count--;
408 		err = 0;
409 		goto done;
410 	}
411 	/* else, add a new source to the filter */
412 
413 	if (psl && psl->sl_count >= sysctl_mld_max_msf) {
414 		err = -ENOBUFS;
415 		goto done;
416 	}
417 	if (!psl || psl->sl_count == psl->sl_max) {
418 		struct ip6_sf_socklist *newpsl;
419 		int count = IP6_SFBLOCK;
420 
421 		if (psl)
422 			count += psl->sl_max;
423 		newpsl = sock_kmalloc(sk, IP6_SFLSIZE(count), GFP_ATOMIC);
424 		if (!newpsl) {
425 			err = -ENOBUFS;
426 			goto done;
427 		}
428 		newpsl->sl_max = count;
429 		newpsl->sl_count = count - IP6_SFBLOCK;
430 		if (psl) {
431 			for (i = 0; i < psl->sl_count; i++)
432 				newpsl->sl_addr[i] = psl->sl_addr[i];
433 			sock_kfree_s(sk, psl, IP6_SFLSIZE(psl->sl_max));
434 		}
435 		pmc->sflist = psl = newpsl;
436 	}
437 	rv = 1;	/* > 0 for insert logic below if sl_count is 0 */
438 	for (i = 0; i < psl->sl_count; i++) {
439 		rv = !ipv6_addr_equal(&psl->sl_addr[i], source);
440 		if (rv == 0) /* There is an error in the address. */
441 			goto done;
442 	}
443 	for (j = psl->sl_count-1; j >= i; j--)
444 		psl->sl_addr[j+1] = psl->sl_addr[j];
445 	psl->sl_addr[i] = *source;
446 	psl->sl_count++;
447 	err = 0;
448 	/* update the interface list */
449 	ip6_mc_add_src(idev, group, omode, 1, source, 1);
450 done:
451 	if (pmclocked)
452 		write_unlock(&pmc->sflock);
453 	read_unlock_bh(&idev->lock);
454 	rcu_read_unlock();
455 	if (leavegroup)
456 		err = ipv6_sock_mc_drop(sk, pgsr->gsr_interface, group);
457 	return err;
458 }
459 
460 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf)
461 {
462 	const struct in6_addr *group;
463 	struct ipv6_mc_socklist *pmc;
464 	struct inet6_dev *idev;
465 	struct ipv6_pinfo *inet6 = inet6_sk(sk);
466 	struct ip6_sf_socklist *newpsl, *psl;
467 	struct net *net = sock_net(sk);
468 	int leavegroup = 0;
469 	int i, err;
470 
471 	group = &((struct sockaddr_in6 *)&gsf->gf_group)->sin6_addr;
472 
473 	if (!ipv6_addr_is_multicast(group))
474 		return -EINVAL;
475 	if (gsf->gf_fmode != MCAST_INCLUDE &&
476 	    gsf->gf_fmode != MCAST_EXCLUDE)
477 		return -EINVAL;
478 
479 	rcu_read_lock();
480 	idev = ip6_mc_find_dev_rcu(net, group, gsf->gf_interface);
481 
482 	if (!idev) {
483 		rcu_read_unlock();
484 		return -ENODEV;
485 	}
486 
487 	err = 0;
488 
489 	if (gsf->gf_fmode == MCAST_INCLUDE && gsf->gf_numsrc == 0) {
490 		leavegroup = 1;
491 		goto done;
492 	}
493 
494 	for_each_pmc_rcu(inet6, pmc) {
495 		if (pmc->ifindex != gsf->gf_interface)
496 			continue;
497 		if (ipv6_addr_equal(&pmc->addr, group))
498 			break;
499 	}
500 	if (!pmc) {		/* must have a prior join */
501 		err = -EINVAL;
502 		goto done;
503 	}
504 	if (gsf->gf_numsrc) {
505 		newpsl = sock_kmalloc(sk, IP6_SFLSIZE(gsf->gf_numsrc),
506 							  GFP_ATOMIC);
507 		if (!newpsl) {
508 			err = -ENOBUFS;
509 			goto done;
510 		}
511 		newpsl->sl_max = newpsl->sl_count = gsf->gf_numsrc;
512 		for (i = 0; i < newpsl->sl_count; ++i) {
513 			struct sockaddr_in6 *psin6;
514 
515 			psin6 = (struct sockaddr_in6 *)&gsf->gf_slist[i];
516 			newpsl->sl_addr[i] = psin6->sin6_addr;
517 		}
518 		err = ip6_mc_add_src(idev, group, gsf->gf_fmode,
519 			newpsl->sl_count, newpsl->sl_addr, 0);
520 		if (err) {
521 			sock_kfree_s(sk, newpsl, IP6_SFLSIZE(newpsl->sl_max));
522 			goto done;
523 		}
524 	} else {
525 		newpsl = NULL;
526 		(void) ip6_mc_add_src(idev, group, gsf->gf_fmode, 0, NULL, 0);
527 	}
528 
529 	write_lock(&pmc->sflock);
530 	psl = pmc->sflist;
531 	if (psl) {
532 		(void) ip6_mc_del_src(idev, group, pmc->sfmode,
533 			psl->sl_count, psl->sl_addr, 0);
534 		sock_kfree_s(sk, psl, IP6_SFLSIZE(psl->sl_max));
535 	} else
536 		(void) ip6_mc_del_src(idev, group, pmc->sfmode, 0, NULL, 0);
537 	pmc->sflist = newpsl;
538 	pmc->sfmode = gsf->gf_fmode;
539 	write_unlock(&pmc->sflock);
540 	err = 0;
541 done:
542 	read_unlock_bh(&idev->lock);
543 	rcu_read_unlock();
544 	if (leavegroup)
545 		err = ipv6_sock_mc_drop(sk, gsf->gf_interface, group);
546 	return err;
547 }
548 
549 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
550 	struct group_filter __user *optval, int __user *optlen)
551 {
552 	int err, i, count, copycount;
553 	const struct in6_addr *group;
554 	struct ipv6_mc_socklist *pmc;
555 	struct inet6_dev *idev;
556 	struct ipv6_pinfo *inet6 = inet6_sk(sk);
557 	struct ip6_sf_socklist *psl;
558 	struct net *net = sock_net(sk);
559 
560 	group = &((struct sockaddr_in6 *)&gsf->gf_group)->sin6_addr;
561 
562 	if (!ipv6_addr_is_multicast(group))
563 		return -EINVAL;
564 
565 	rcu_read_lock();
566 	idev = ip6_mc_find_dev_rcu(net, group, gsf->gf_interface);
567 
568 	if (!idev) {
569 		rcu_read_unlock();
570 		return -ENODEV;
571 	}
572 
573 	err = -EADDRNOTAVAIL;
574 	/* changes to the ipv6_mc_list require the socket lock and
575 	 * rtnl lock. We have the socket lock and rcu read lock,
576 	 * so reading the list is safe.
577 	 */
578 
579 	for_each_pmc_rcu(inet6, pmc) {
580 		if (pmc->ifindex != gsf->gf_interface)
581 			continue;
582 		if (ipv6_addr_equal(group, &pmc->addr))
583 			break;
584 	}
585 	if (!pmc)		/* must have a prior join */
586 		goto done;
587 	gsf->gf_fmode = pmc->sfmode;
588 	psl = pmc->sflist;
589 	count = psl ? psl->sl_count : 0;
590 	read_unlock_bh(&idev->lock);
591 	rcu_read_unlock();
592 
593 	copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
594 	gsf->gf_numsrc = count;
595 	if (put_user(GROUP_FILTER_SIZE(copycount), optlen) ||
596 	    copy_to_user(optval, gsf, GROUP_FILTER_SIZE(0))) {
597 		return -EFAULT;
598 	}
599 	/* changes to psl require the socket lock, and a write lock
600 	 * on pmc->sflock. We have the socket lock so reading here is safe.
601 	 */
602 	for (i = 0; i < copycount; i++) {
603 		struct sockaddr_in6 *psin6;
604 		struct sockaddr_storage ss;
605 
606 		psin6 = (struct sockaddr_in6 *)&ss;
607 		memset(&ss, 0, sizeof(ss));
608 		psin6->sin6_family = AF_INET6;
609 		psin6->sin6_addr = psl->sl_addr[i];
610 		if (copy_to_user(&optval->gf_slist[i], &ss, sizeof(ss)))
611 			return -EFAULT;
612 	}
613 	return 0;
614 done:
615 	read_unlock_bh(&idev->lock);
616 	rcu_read_unlock();
617 	return err;
618 }
619 
620 bool inet6_mc_check(struct sock *sk, const struct in6_addr *mc_addr,
621 		    const struct in6_addr *src_addr)
622 {
623 	struct ipv6_pinfo *np = inet6_sk(sk);
624 	struct ipv6_mc_socklist *mc;
625 	struct ip6_sf_socklist *psl;
626 	bool rv = true;
627 
628 	rcu_read_lock();
629 	for_each_pmc_rcu(np, mc) {
630 		if (ipv6_addr_equal(&mc->addr, mc_addr))
631 			break;
632 	}
633 	if (!mc) {
634 		rcu_read_unlock();
635 		return np->mc_all;
636 	}
637 	read_lock(&mc->sflock);
638 	psl = mc->sflist;
639 	if (!psl) {
640 		rv = mc->sfmode == MCAST_EXCLUDE;
641 	} else {
642 		int i;
643 
644 		for (i = 0; i < psl->sl_count; i++) {
645 			if (ipv6_addr_equal(&psl->sl_addr[i], src_addr))
646 				break;
647 		}
648 		if (mc->sfmode == MCAST_INCLUDE && i >= psl->sl_count)
649 			rv = false;
650 		if (mc->sfmode == MCAST_EXCLUDE && i < psl->sl_count)
651 			rv = false;
652 	}
653 	read_unlock(&mc->sflock);
654 	rcu_read_unlock();
655 
656 	return rv;
657 }
658 
659 static void igmp6_group_added(struct ifmcaddr6 *mc)
660 {
661 	struct net_device *dev = mc->idev->dev;
662 	char buf[MAX_ADDR_LEN];
663 
664 	if (IPV6_ADDR_MC_SCOPE(&mc->mca_addr) <
665 	    IPV6_ADDR_SCOPE_LINKLOCAL)
666 		return;
667 
668 	spin_lock_bh(&mc->mca_lock);
669 	if (!(mc->mca_flags&MAF_LOADED)) {
670 		mc->mca_flags |= MAF_LOADED;
671 		if (ndisc_mc_map(&mc->mca_addr, buf, dev, 0) == 0)
672 			dev_mc_add(dev, buf);
673 	}
674 	spin_unlock_bh(&mc->mca_lock);
675 
676 	if (!(dev->flags & IFF_UP) || (mc->mca_flags & MAF_NOREPORT))
677 		return;
678 
679 	if (mld_in_v1_mode(mc->idev)) {
680 		igmp6_join_group(mc);
681 		return;
682 	}
683 	/* else v2 */
684 
685 	/* Based on RFC3810 6.1, for newly added INCLUDE SSM, we
686 	 * should not send filter-mode change record as the mode
687 	 * should be from IN() to IN(A).
688 	 */
689 	if (mc->mca_sfmode == MCAST_EXCLUDE)
690 		mc->mca_crcount = mc->idev->mc_qrv;
691 
692 	mld_ifc_event(mc->idev);
693 }
694 
695 static void igmp6_group_dropped(struct ifmcaddr6 *mc)
696 {
697 	struct net_device *dev = mc->idev->dev;
698 	char buf[MAX_ADDR_LEN];
699 
700 	if (IPV6_ADDR_MC_SCOPE(&mc->mca_addr) <
701 	    IPV6_ADDR_SCOPE_LINKLOCAL)
702 		return;
703 
704 	spin_lock_bh(&mc->mca_lock);
705 	if (mc->mca_flags&MAF_LOADED) {
706 		mc->mca_flags &= ~MAF_LOADED;
707 		if (ndisc_mc_map(&mc->mca_addr, buf, dev, 0) == 0)
708 			dev_mc_del(dev, buf);
709 	}
710 
711 	spin_unlock_bh(&mc->mca_lock);
712 	if (mc->mca_flags & MAF_NOREPORT)
713 		return;
714 
715 	if (!mc->idev->dead)
716 		igmp6_leave_group(mc);
717 
718 	spin_lock_bh(&mc->mca_lock);
719 	if (del_timer(&mc->mca_timer))
720 		refcount_dec(&mc->mca_refcnt);
721 	spin_unlock_bh(&mc->mca_lock);
722 }
723 
724 /*
725  * deleted ifmcaddr6 manipulation
726  */
727 static void mld_add_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im)
728 {
729 	struct ifmcaddr6 *pmc;
730 
731 	/* this is an "ifmcaddr6" for convenience; only the fields below
732 	 * are actually used. In particular, the refcnt and users are not
733 	 * used for management of the delete list. Using the same structure
734 	 * for deleted items allows change reports to use common code with
735 	 * non-deleted or query-response MCA's.
736 	 */
737 	pmc = kzalloc(sizeof(*pmc), GFP_ATOMIC);
738 	if (!pmc)
739 		return;
740 
741 	spin_lock_bh(&im->mca_lock);
742 	spin_lock_init(&pmc->mca_lock);
743 	pmc->idev = im->idev;
744 	in6_dev_hold(idev);
745 	pmc->mca_addr = im->mca_addr;
746 	pmc->mca_crcount = idev->mc_qrv;
747 	pmc->mca_sfmode = im->mca_sfmode;
748 	if (pmc->mca_sfmode == MCAST_INCLUDE) {
749 		struct ip6_sf_list *psf;
750 
751 		pmc->mca_tomb = im->mca_tomb;
752 		pmc->mca_sources = im->mca_sources;
753 		im->mca_tomb = im->mca_sources = NULL;
754 		for (psf = pmc->mca_sources; psf; psf = psf->sf_next)
755 			psf->sf_crcount = pmc->mca_crcount;
756 	}
757 	spin_unlock_bh(&im->mca_lock);
758 
759 	spin_lock_bh(&idev->mc_lock);
760 	pmc->next = idev->mc_tomb;
761 	idev->mc_tomb = pmc;
762 	spin_unlock_bh(&idev->mc_lock);
763 }
764 
765 static void mld_del_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im)
766 {
767 	struct ifmcaddr6 *pmc, *pmc_prev;
768 	struct ip6_sf_list *psf;
769 	struct in6_addr *pmca = &im->mca_addr;
770 
771 	spin_lock_bh(&idev->mc_lock);
772 	pmc_prev = NULL;
773 	for (pmc = idev->mc_tomb; pmc; pmc = pmc->next) {
774 		if (ipv6_addr_equal(&pmc->mca_addr, pmca))
775 			break;
776 		pmc_prev = pmc;
777 	}
778 	if (pmc) {
779 		if (pmc_prev)
780 			pmc_prev->next = pmc->next;
781 		else
782 			idev->mc_tomb = pmc->next;
783 	}
784 	spin_unlock_bh(&idev->mc_lock);
785 
786 	spin_lock_bh(&im->mca_lock);
787 	if (pmc) {
788 		im->idev = pmc->idev;
789 		if (im->mca_sfmode == MCAST_INCLUDE) {
790 			swap(im->mca_tomb, pmc->mca_tomb);
791 			swap(im->mca_sources, pmc->mca_sources);
792 			for (psf = im->mca_sources; psf; psf = psf->sf_next)
793 				psf->sf_crcount = idev->mc_qrv;
794 		} else {
795 			im->mca_crcount = idev->mc_qrv;
796 		}
797 		in6_dev_put(pmc->idev);
798 		ip6_mc_clear_src(pmc);
799 		kfree(pmc);
800 	}
801 	spin_unlock_bh(&im->mca_lock);
802 }
803 
804 static void mld_clear_delrec(struct inet6_dev *idev)
805 {
806 	struct ifmcaddr6 *pmc, *nextpmc;
807 
808 	spin_lock_bh(&idev->mc_lock);
809 	pmc = idev->mc_tomb;
810 	idev->mc_tomb = NULL;
811 	spin_unlock_bh(&idev->mc_lock);
812 
813 	for (; pmc; pmc = nextpmc) {
814 		nextpmc = pmc->next;
815 		ip6_mc_clear_src(pmc);
816 		in6_dev_put(pmc->idev);
817 		kfree(pmc);
818 	}
819 
820 	/* clear dead sources, too */
821 	read_lock_bh(&idev->lock);
822 	for (pmc = idev->mc_list; pmc; pmc = pmc->next) {
823 		struct ip6_sf_list *psf, *psf_next;
824 
825 		spin_lock_bh(&pmc->mca_lock);
826 		psf = pmc->mca_tomb;
827 		pmc->mca_tomb = NULL;
828 		spin_unlock_bh(&pmc->mca_lock);
829 		for (; psf; psf = psf_next) {
830 			psf_next = psf->sf_next;
831 			kfree(psf);
832 		}
833 	}
834 	read_unlock_bh(&idev->lock);
835 }
836 
837 static void mca_get(struct ifmcaddr6 *mc)
838 {
839 	refcount_inc(&mc->mca_refcnt);
840 }
841 
842 static void ma_put(struct ifmcaddr6 *mc)
843 {
844 	if (refcount_dec_and_test(&mc->mca_refcnt)) {
845 		in6_dev_put(mc->idev);
846 		kfree(mc);
847 	}
848 }
849 
850 static struct ifmcaddr6 *mca_alloc(struct inet6_dev *idev,
851 				   const struct in6_addr *addr,
852 				   unsigned int mode)
853 {
854 	struct ifmcaddr6 *mc;
855 
856 	mc = kzalloc(sizeof(*mc), GFP_ATOMIC);
857 	if (!mc)
858 		return NULL;
859 
860 	timer_setup(&mc->mca_timer, igmp6_timer_handler, 0);
861 
862 	mc->mca_addr = *addr;
863 	mc->idev = idev; /* reference taken by caller */
864 	mc->mca_users = 1;
865 	/* mca_stamp should be updated upon changes */
866 	mc->mca_cstamp = mc->mca_tstamp = jiffies;
867 	refcount_set(&mc->mca_refcnt, 1);
868 	spin_lock_init(&mc->mca_lock);
869 
870 	mc->mca_sfmode = mode;
871 	mc->mca_sfcount[mode] = 1;
872 
873 	if (ipv6_addr_is_ll_all_nodes(&mc->mca_addr) ||
874 	    IPV6_ADDR_MC_SCOPE(&mc->mca_addr) < IPV6_ADDR_SCOPE_LINKLOCAL)
875 		mc->mca_flags |= MAF_NOREPORT;
876 
877 	return mc;
878 }
879 
880 /*
881  *	device multicast group inc (add if not found)
882  */
883 static int __ipv6_dev_mc_inc(struct net_device *dev,
884 			     const struct in6_addr *addr, unsigned int mode)
885 {
886 	struct ifmcaddr6 *mc;
887 	struct inet6_dev *idev;
888 
889 	ASSERT_RTNL();
890 
891 	/* we need to take a reference on idev */
892 	idev = in6_dev_get(dev);
893 
894 	if (!idev)
895 		return -EINVAL;
896 
897 	write_lock_bh(&idev->lock);
898 	if (idev->dead) {
899 		write_unlock_bh(&idev->lock);
900 		in6_dev_put(idev);
901 		return -ENODEV;
902 	}
903 
904 	for (mc = idev->mc_list; mc; mc = mc->next) {
905 		if (ipv6_addr_equal(&mc->mca_addr, addr)) {
906 			mc->mca_users++;
907 			write_unlock_bh(&idev->lock);
908 			ip6_mc_add_src(idev, &mc->mca_addr, mode, 0, NULL, 0);
909 			in6_dev_put(idev);
910 			return 0;
911 		}
912 	}
913 
914 	mc = mca_alloc(idev, addr, mode);
915 	if (!mc) {
916 		write_unlock_bh(&idev->lock);
917 		in6_dev_put(idev);
918 		return -ENOMEM;
919 	}
920 
921 	mc->next = idev->mc_list;
922 	idev->mc_list = mc;
923 
924 	/* Hold this for the code below before we unlock,
925 	 * it is already exposed via idev->mc_list.
926 	 */
927 	mca_get(mc);
928 	write_unlock_bh(&idev->lock);
929 
930 	mld_del_delrec(idev, mc);
931 	igmp6_group_added(mc);
932 	ma_put(mc);
933 	return 0;
934 }
935 
936 int ipv6_dev_mc_inc(struct net_device *dev, const struct in6_addr *addr)
937 {
938 	return __ipv6_dev_mc_inc(dev, addr, MCAST_EXCLUDE);
939 }
940 EXPORT_SYMBOL(ipv6_dev_mc_inc);
941 
942 /*
943  *	device multicast group del
944  */
945 int __ipv6_dev_mc_dec(struct inet6_dev *idev, const struct in6_addr *addr)
946 {
947 	struct ifmcaddr6 *ma, **map;
948 
949 	ASSERT_RTNL();
950 
951 	write_lock_bh(&idev->lock);
952 	for (map = &idev->mc_list; (ma = *map) != NULL; map = &ma->next) {
953 		if (ipv6_addr_equal(&ma->mca_addr, addr)) {
954 			if (--ma->mca_users == 0) {
955 				*map = ma->next;
956 				write_unlock_bh(&idev->lock);
957 
958 				igmp6_group_dropped(ma);
959 				ip6_mc_clear_src(ma);
960 
961 				ma_put(ma);
962 				return 0;
963 			}
964 			write_unlock_bh(&idev->lock);
965 			return 0;
966 		}
967 	}
968 	write_unlock_bh(&idev->lock);
969 
970 	return -ENOENT;
971 }
972 
973 int ipv6_dev_mc_dec(struct net_device *dev, const struct in6_addr *addr)
974 {
975 	struct inet6_dev *idev;
976 	int err;
977 
978 	ASSERT_RTNL();
979 
980 	idev = __in6_dev_get(dev);
981 	if (!idev)
982 		err = -ENODEV;
983 	else
984 		err = __ipv6_dev_mc_dec(idev, addr);
985 
986 	return err;
987 }
988 EXPORT_SYMBOL(ipv6_dev_mc_dec);
989 
990 /*
991  *	check if the interface/address pair is valid
992  */
993 bool ipv6_chk_mcast_addr(struct net_device *dev, const struct in6_addr *group,
994 			 const struct in6_addr *src_addr)
995 {
996 	struct inet6_dev *idev;
997 	struct ifmcaddr6 *mc;
998 	bool rv = false;
999 
1000 	rcu_read_lock();
1001 	idev = __in6_dev_get(dev);
1002 	if (idev) {
1003 		read_lock_bh(&idev->lock);
1004 		for (mc = idev->mc_list; mc; mc = mc->next) {
1005 			if (ipv6_addr_equal(&mc->mca_addr, group))
1006 				break;
1007 		}
1008 		if (mc) {
1009 			if (src_addr && !ipv6_addr_any(src_addr)) {
1010 				struct ip6_sf_list *psf;
1011 
1012 				spin_lock_bh(&mc->mca_lock);
1013 				for (psf = mc->mca_sources; psf; psf = psf->sf_next) {
1014 					if (ipv6_addr_equal(&psf->sf_addr, src_addr))
1015 						break;
1016 				}
1017 				if (psf)
1018 					rv = psf->sf_count[MCAST_INCLUDE] ||
1019 						psf->sf_count[MCAST_EXCLUDE] !=
1020 						mc->mca_sfcount[MCAST_EXCLUDE];
1021 				else
1022 					rv = mc->mca_sfcount[MCAST_EXCLUDE] != 0;
1023 				spin_unlock_bh(&mc->mca_lock);
1024 			} else
1025 				rv = true; /* don't filter unspecified source */
1026 		}
1027 		read_unlock_bh(&idev->lock);
1028 	}
1029 	rcu_read_unlock();
1030 	return rv;
1031 }
1032 
1033 static void mld_gq_start_timer(struct inet6_dev *idev)
1034 {
1035 	unsigned long tv = prandom_u32() % idev->mc_maxdelay;
1036 
1037 	idev->mc_gq_running = 1;
1038 	if (!mod_timer(&idev->mc_gq_timer, jiffies+tv+2))
1039 		in6_dev_hold(idev);
1040 }
1041 
1042 static void mld_gq_stop_timer(struct inet6_dev *idev)
1043 {
1044 	idev->mc_gq_running = 0;
1045 	if (del_timer(&idev->mc_gq_timer))
1046 		__in6_dev_put(idev);
1047 }
1048 
1049 static void mld_ifc_start_timer(struct inet6_dev *idev, unsigned long delay)
1050 {
1051 	unsigned long tv = prandom_u32() % delay;
1052 
1053 	if (!mod_timer(&idev->mc_ifc_timer, jiffies+tv+2))
1054 		in6_dev_hold(idev);
1055 }
1056 
1057 static void mld_ifc_stop_timer(struct inet6_dev *idev)
1058 {
1059 	idev->mc_ifc_count = 0;
1060 	if (del_timer(&idev->mc_ifc_timer))
1061 		__in6_dev_put(idev);
1062 }
1063 
1064 static void mld_dad_start_timer(struct inet6_dev *idev, unsigned long delay)
1065 {
1066 	unsigned long tv = prandom_u32() % delay;
1067 
1068 	if (!mod_timer(&idev->mc_dad_timer, jiffies+tv+2))
1069 		in6_dev_hold(idev);
1070 }
1071 
1072 static void mld_dad_stop_timer(struct inet6_dev *idev)
1073 {
1074 	if (del_timer(&idev->mc_dad_timer))
1075 		__in6_dev_put(idev);
1076 }
1077 
1078 /*
1079  *	IGMP handling (alias multicast ICMPv6 messages)
1080  */
1081 
1082 static void igmp6_group_queried(struct ifmcaddr6 *ma, unsigned long resptime)
1083 {
1084 	unsigned long delay = resptime;
1085 
1086 	/* Do not start timer for these addresses */
1087 	if (ipv6_addr_is_ll_all_nodes(&ma->mca_addr) ||
1088 	    IPV6_ADDR_MC_SCOPE(&ma->mca_addr) < IPV6_ADDR_SCOPE_LINKLOCAL)
1089 		return;
1090 
1091 	if (del_timer(&ma->mca_timer)) {
1092 		refcount_dec(&ma->mca_refcnt);
1093 		delay = ma->mca_timer.expires - jiffies;
1094 	}
1095 
1096 	if (delay >= resptime)
1097 		delay = prandom_u32() % resptime;
1098 
1099 	ma->mca_timer.expires = jiffies + delay;
1100 	if (!mod_timer(&ma->mca_timer, jiffies + delay))
1101 		refcount_inc(&ma->mca_refcnt);
1102 	ma->mca_flags |= MAF_TIMER_RUNNING;
1103 }
1104 
1105 /* mark EXCLUDE-mode sources */
1106 static bool mld_xmarksources(struct ifmcaddr6 *pmc, int nsrcs,
1107 			     const struct in6_addr *srcs)
1108 {
1109 	struct ip6_sf_list *psf;
1110 	int i, scount;
1111 
1112 	scount = 0;
1113 	for (psf = pmc->mca_sources; psf; psf = psf->sf_next) {
1114 		if (scount == nsrcs)
1115 			break;
1116 		for (i = 0; i < nsrcs; i++) {
1117 			/* skip inactive filters */
1118 			if (psf->sf_count[MCAST_INCLUDE] ||
1119 			    pmc->mca_sfcount[MCAST_EXCLUDE] !=
1120 			    psf->sf_count[MCAST_EXCLUDE])
1121 				break;
1122 			if (ipv6_addr_equal(&srcs[i], &psf->sf_addr)) {
1123 				scount++;
1124 				break;
1125 			}
1126 		}
1127 	}
1128 	pmc->mca_flags &= ~MAF_GSQUERY;
1129 	if (scount == nsrcs)	/* all sources excluded */
1130 		return false;
1131 	return true;
1132 }
1133 
1134 static bool mld_marksources(struct ifmcaddr6 *pmc, int nsrcs,
1135 			    const struct in6_addr *srcs)
1136 {
1137 	struct ip6_sf_list *psf;
1138 	int i, scount;
1139 
1140 	if (pmc->mca_sfmode == MCAST_EXCLUDE)
1141 		return mld_xmarksources(pmc, nsrcs, srcs);
1142 
1143 	/* mark INCLUDE-mode sources */
1144 
1145 	scount = 0;
1146 	for (psf = pmc->mca_sources; psf; psf = psf->sf_next) {
1147 		if (scount == nsrcs)
1148 			break;
1149 		for (i = 0; i < nsrcs; i++) {
1150 			if (ipv6_addr_equal(&srcs[i], &psf->sf_addr)) {
1151 				psf->sf_gsresp = 1;
1152 				scount++;
1153 				break;
1154 			}
1155 		}
1156 	}
1157 	if (!scount) {
1158 		pmc->mca_flags &= ~MAF_GSQUERY;
1159 		return false;
1160 	}
1161 	pmc->mca_flags |= MAF_GSQUERY;
1162 	return true;
1163 }
1164 
1165 static int mld_force_mld_version(const struct inet6_dev *idev)
1166 {
1167 	/* Normally, both are 0 here. If enforcement to a particular is
1168 	 * being used, individual device enforcement will have a lower
1169 	 * precedence over 'all' device (.../conf/all/force_mld_version).
1170 	 */
1171 
1172 	if (dev_net(idev->dev)->ipv6.devconf_all->force_mld_version != 0)
1173 		return dev_net(idev->dev)->ipv6.devconf_all->force_mld_version;
1174 	else
1175 		return idev->cnf.force_mld_version;
1176 }
1177 
1178 static bool mld_in_v2_mode_only(const struct inet6_dev *idev)
1179 {
1180 	return mld_force_mld_version(idev) == 2;
1181 }
1182 
1183 static bool mld_in_v1_mode_only(const struct inet6_dev *idev)
1184 {
1185 	return mld_force_mld_version(idev) == 1;
1186 }
1187 
1188 static bool mld_in_v1_mode(const struct inet6_dev *idev)
1189 {
1190 	if (mld_in_v2_mode_only(idev))
1191 		return false;
1192 	if (mld_in_v1_mode_only(idev))
1193 		return true;
1194 	if (idev->mc_v1_seen && time_before(jiffies, idev->mc_v1_seen))
1195 		return true;
1196 
1197 	return false;
1198 }
1199 
1200 static void mld_set_v1_mode(struct inet6_dev *idev)
1201 {
1202 	/* RFC3810, relevant sections:
1203 	 *  - 9.1. Robustness Variable
1204 	 *  - 9.2. Query Interval
1205 	 *  - 9.3. Query Response Interval
1206 	 *  - 9.12. Older Version Querier Present Timeout
1207 	 */
1208 	unsigned long switchback;
1209 
1210 	switchback = (idev->mc_qrv * idev->mc_qi) + idev->mc_qri;
1211 
1212 	idev->mc_v1_seen = jiffies + switchback;
1213 }
1214 
1215 static void mld_update_qrv(struct inet6_dev *idev,
1216 			   const struct mld2_query *mlh2)
1217 {
1218 	/* RFC3810, relevant sections:
1219 	 *  - 5.1.8. QRV (Querier's Robustness Variable)
1220 	 *  - 9.1. Robustness Variable
1221 	 */
1222 
1223 	/* The value of the Robustness Variable MUST NOT be zero,
1224 	 * and SHOULD NOT be one. Catch this here if we ever run
1225 	 * into such a case in future.
1226 	 */
1227 	const int min_qrv = min(MLD_QRV_DEFAULT, sysctl_mld_qrv);
1228 	WARN_ON(idev->mc_qrv == 0);
1229 
1230 	if (mlh2->mld2q_qrv > 0)
1231 		idev->mc_qrv = mlh2->mld2q_qrv;
1232 
1233 	if (unlikely(idev->mc_qrv < min_qrv)) {
1234 		net_warn_ratelimited("IPv6: MLD: clamping QRV from %u to %u!\n",
1235 				     idev->mc_qrv, min_qrv);
1236 		idev->mc_qrv = min_qrv;
1237 	}
1238 }
1239 
1240 static void mld_update_qi(struct inet6_dev *idev,
1241 			  const struct mld2_query *mlh2)
1242 {
1243 	/* RFC3810, relevant sections:
1244 	 *  - 5.1.9. QQIC (Querier's Query Interval Code)
1245 	 *  - 9.2. Query Interval
1246 	 *  - 9.12. Older Version Querier Present Timeout
1247 	 *    (the [Query Interval] in the last Query received)
1248 	 */
1249 	unsigned long mc_qqi;
1250 
1251 	if (mlh2->mld2q_qqic < 128) {
1252 		mc_qqi = mlh2->mld2q_qqic;
1253 	} else {
1254 		unsigned long mc_man, mc_exp;
1255 
1256 		mc_exp = MLDV2_QQIC_EXP(mlh2->mld2q_qqic);
1257 		mc_man = MLDV2_QQIC_MAN(mlh2->mld2q_qqic);
1258 
1259 		mc_qqi = (mc_man | 0x10) << (mc_exp + 3);
1260 	}
1261 
1262 	idev->mc_qi = mc_qqi * HZ;
1263 }
1264 
1265 static void mld_update_qri(struct inet6_dev *idev,
1266 			   const struct mld2_query *mlh2)
1267 {
1268 	/* RFC3810, relevant sections:
1269 	 *  - 5.1.3. Maximum Response Code
1270 	 *  - 9.3. Query Response Interval
1271 	 */
1272 	idev->mc_qri = msecs_to_jiffies(mldv2_mrc(mlh2));
1273 }
1274 
1275 static int mld_process_v1(struct inet6_dev *idev, struct mld_msg *mld,
1276 			  unsigned long *max_delay, bool v1_query)
1277 {
1278 	unsigned long mldv1_md;
1279 
1280 	/* Ignore v1 queries */
1281 	if (mld_in_v2_mode_only(idev))
1282 		return -EINVAL;
1283 
1284 	mldv1_md = ntohs(mld->mld_maxdelay);
1285 
1286 	/* When in MLDv1 fallback and a MLDv2 router start-up being
1287 	 * unaware of current MLDv1 operation, the MRC == MRD mapping
1288 	 * only works when the exponential algorithm is not being
1289 	 * used (as MLDv1 is unaware of such things).
1290 	 *
1291 	 * According to the RFC author, the MLDv2 implementations
1292 	 * he's aware of all use a MRC < 32768 on start up queries.
1293 	 *
1294 	 * Thus, should we *ever* encounter something else larger
1295 	 * than that, just assume the maximum possible within our
1296 	 * reach.
1297 	 */
1298 	if (!v1_query)
1299 		mldv1_md = min(mldv1_md, MLDV1_MRD_MAX_COMPAT);
1300 
1301 	*max_delay = max(msecs_to_jiffies(mldv1_md), 1UL);
1302 
1303 	/* MLDv1 router present: we need to go into v1 mode *only*
1304 	 * when an MLDv1 query is received as per section 9.12. of
1305 	 * RFC3810! And we know from RFC2710 section 3.7 that MLDv1
1306 	 * queries MUST be of exactly 24 octets.
1307 	 */
1308 	if (v1_query)
1309 		mld_set_v1_mode(idev);
1310 
1311 	/* cancel MLDv2 report timer */
1312 	mld_gq_stop_timer(idev);
1313 	/* cancel the interface change timer */
1314 	mld_ifc_stop_timer(idev);
1315 	/* clear deleted report items */
1316 	mld_clear_delrec(idev);
1317 
1318 	return 0;
1319 }
1320 
1321 static int mld_process_v2(struct inet6_dev *idev, struct mld2_query *mld,
1322 			  unsigned long *max_delay)
1323 {
1324 	*max_delay = max(msecs_to_jiffies(mldv2_mrc(mld)), 1UL);
1325 
1326 	mld_update_qrv(idev, mld);
1327 	mld_update_qi(idev, mld);
1328 	mld_update_qri(idev, mld);
1329 
1330 	idev->mc_maxdelay = *max_delay;
1331 
1332 	return 0;
1333 }
1334 
1335 /* called with rcu_read_lock() */
1336 int igmp6_event_query(struct sk_buff *skb)
1337 {
1338 	struct mld2_query *mlh2 = NULL;
1339 	struct ifmcaddr6 *ma;
1340 	const struct in6_addr *group;
1341 	unsigned long max_delay;
1342 	struct inet6_dev *idev;
1343 	struct mld_msg *mld;
1344 	int group_type;
1345 	int mark = 0;
1346 	int len, err;
1347 
1348 	if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
1349 		return -EINVAL;
1350 
1351 	/* compute payload length excluding extension headers */
1352 	len = ntohs(ipv6_hdr(skb)->payload_len) + sizeof(struct ipv6hdr);
1353 	len -= skb_network_header_len(skb);
1354 
1355 	/* RFC3810 6.2
1356 	 * Upon reception of an MLD message that contains a Query, the node
1357 	 * checks if the source address of the message is a valid link-local
1358 	 * address, if the Hop Limit is set to 1, and if the Router Alert
1359 	 * option is present in the Hop-By-Hop Options header of the IPv6
1360 	 * packet.  If any of these checks fails, the packet is dropped.
1361 	 */
1362 	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL) ||
1363 	    ipv6_hdr(skb)->hop_limit != 1 ||
1364 	    !(IP6CB(skb)->flags & IP6SKB_ROUTERALERT) ||
1365 	    IP6CB(skb)->ra != htons(IPV6_OPT_ROUTERALERT_MLD))
1366 		return -EINVAL;
1367 
1368 	idev = __in6_dev_get(skb->dev);
1369 	if (!idev)
1370 		return 0;
1371 
1372 	mld = (struct mld_msg *)icmp6_hdr(skb);
1373 	group = &mld->mld_mca;
1374 	group_type = ipv6_addr_type(group);
1375 
1376 	if (group_type != IPV6_ADDR_ANY &&
1377 	    !(group_type&IPV6_ADDR_MULTICAST))
1378 		return -EINVAL;
1379 
1380 	if (len < MLD_V1_QUERY_LEN) {
1381 		return -EINVAL;
1382 	} else if (len == MLD_V1_QUERY_LEN || mld_in_v1_mode(idev)) {
1383 		err = mld_process_v1(idev, mld, &max_delay,
1384 				     len == MLD_V1_QUERY_LEN);
1385 		if (err < 0)
1386 			return err;
1387 	} else if (len >= MLD_V2_QUERY_LEN_MIN) {
1388 		int srcs_offset = sizeof(struct mld2_query) -
1389 				  sizeof(struct icmp6hdr);
1390 
1391 		if (!pskb_may_pull(skb, srcs_offset))
1392 			return -EINVAL;
1393 
1394 		mlh2 = (struct mld2_query *)skb_transport_header(skb);
1395 
1396 		err = mld_process_v2(idev, mlh2, &max_delay);
1397 		if (err < 0)
1398 			return err;
1399 
1400 		if (group_type == IPV6_ADDR_ANY) { /* general query */
1401 			if (mlh2->mld2q_nsrcs)
1402 				return -EINVAL; /* no sources allowed */
1403 
1404 			mld_gq_start_timer(idev);
1405 			return 0;
1406 		}
1407 		/* mark sources to include, if group & source-specific */
1408 		if (mlh2->mld2q_nsrcs != 0) {
1409 			if (!pskb_may_pull(skb, srcs_offset +
1410 			    ntohs(mlh2->mld2q_nsrcs) * sizeof(struct in6_addr)))
1411 				return -EINVAL;
1412 
1413 			mlh2 = (struct mld2_query *)skb_transport_header(skb);
1414 			mark = 1;
1415 		}
1416 	} else {
1417 		return -EINVAL;
1418 	}
1419 
1420 	read_lock_bh(&idev->lock);
1421 	if (group_type == IPV6_ADDR_ANY) {
1422 		for (ma = idev->mc_list; ma; ma = ma->next) {
1423 			spin_lock_bh(&ma->mca_lock);
1424 			igmp6_group_queried(ma, max_delay);
1425 			spin_unlock_bh(&ma->mca_lock);
1426 		}
1427 	} else {
1428 		for (ma = idev->mc_list; ma; ma = ma->next) {
1429 			if (!ipv6_addr_equal(group, &ma->mca_addr))
1430 				continue;
1431 			spin_lock_bh(&ma->mca_lock);
1432 			if (ma->mca_flags & MAF_TIMER_RUNNING) {
1433 				/* gsquery <- gsquery && mark */
1434 				if (!mark)
1435 					ma->mca_flags &= ~MAF_GSQUERY;
1436 			} else {
1437 				/* gsquery <- mark */
1438 				if (mark)
1439 					ma->mca_flags |= MAF_GSQUERY;
1440 				else
1441 					ma->mca_flags &= ~MAF_GSQUERY;
1442 			}
1443 			if (!(ma->mca_flags & MAF_GSQUERY) ||
1444 			    mld_marksources(ma, ntohs(mlh2->mld2q_nsrcs), mlh2->mld2q_srcs))
1445 				igmp6_group_queried(ma, max_delay);
1446 			spin_unlock_bh(&ma->mca_lock);
1447 			break;
1448 		}
1449 	}
1450 	read_unlock_bh(&idev->lock);
1451 
1452 	return 0;
1453 }
1454 
1455 /* called with rcu_read_lock() */
1456 int igmp6_event_report(struct sk_buff *skb)
1457 {
1458 	struct ifmcaddr6 *ma;
1459 	struct inet6_dev *idev;
1460 	struct mld_msg *mld;
1461 	int addr_type;
1462 
1463 	/* Our own report looped back. Ignore it. */
1464 	if (skb->pkt_type == PACKET_LOOPBACK)
1465 		return 0;
1466 
1467 	/* send our report if the MC router may not have heard this report */
1468 	if (skb->pkt_type != PACKET_MULTICAST &&
1469 	    skb->pkt_type != PACKET_BROADCAST)
1470 		return 0;
1471 
1472 	if (!pskb_may_pull(skb, sizeof(*mld) - sizeof(struct icmp6hdr)))
1473 		return -EINVAL;
1474 
1475 	mld = (struct mld_msg *)icmp6_hdr(skb);
1476 
1477 	/* Drop reports with not link local source */
1478 	addr_type = ipv6_addr_type(&ipv6_hdr(skb)->saddr);
1479 	if (addr_type != IPV6_ADDR_ANY &&
1480 	    !(addr_type&IPV6_ADDR_LINKLOCAL))
1481 		return -EINVAL;
1482 
1483 	idev = __in6_dev_get(skb->dev);
1484 	if (!idev)
1485 		return -ENODEV;
1486 
1487 	/*
1488 	 *	Cancel the timer for this group
1489 	 */
1490 
1491 	read_lock_bh(&idev->lock);
1492 	for (ma = idev->mc_list; ma; ma = ma->next) {
1493 		if (ipv6_addr_equal(&ma->mca_addr, &mld->mld_mca)) {
1494 			spin_lock(&ma->mca_lock);
1495 			if (del_timer(&ma->mca_timer))
1496 				refcount_dec(&ma->mca_refcnt);
1497 			ma->mca_flags &= ~(MAF_LAST_REPORTER|MAF_TIMER_RUNNING);
1498 			spin_unlock(&ma->mca_lock);
1499 			break;
1500 		}
1501 	}
1502 	read_unlock_bh(&idev->lock);
1503 	return 0;
1504 }
1505 
1506 static bool is_in(struct ifmcaddr6 *pmc, struct ip6_sf_list *psf, int type,
1507 		  int gdeleted, int sdeleted)
1508 {
1509 	switch (type) {
1510 	case MLD2_MODE_IS_INCLUDE:
1511 	case MLD2_MODE_IS_EXCLUDE:
1512 		if (gdeleted || sdeleted)
1513 			return false;
1514 		if (!((pmc->mca_flags & MAF_GSQUERY) && !psf->sf_gsresp)) {
1515 			if (pmc->mca_sfmode == MCAST_INCLUDE)
1516 				return true;
1517 			/* don't include if this source is excluded
1518 			 * in all filters
1519 			 */
1520 			if (psf->sf_count[MCAST_INCLUDE])
1521 				return type == MLD2_MODE_IS_INCLUDE;
1522 			return pmc->mca_sfcount[MCAST_EXCLUDE] ==
1523 				psf->sf_count[MCAST_EXCLUDE];
1524 		}
1525 		return false;
1526 	case MLD2_CHANGE_TO_INCLUDE:
1527 		if (gdeleted || sdeleted)
1528 			return false;
1529 		return psf->sf_count[MCAST_INCLUDE] != 0;
1530 	case MLD2_CHANGE_TO_EXCLUDE:
1531 		if (gdeleted || sdeleted)
1532 			return false;
1533 		if (pmc->mca_sfcount[MCAST_EXCLUDE] == 0 ||
1534 		    psf->sf_count[MCAST_INCLUDE])
1535 			return false;
1536 		return pmc->mca_sfcount[MCAST_EXCLUDE] ==
1537 			psf->sf_count[MCAST_EXCLUDE];
1538 	case MLD2_ALLOW_NEW_SOURCES:
1539 		if (gdeleted || !psf->sf_crcount)
1540 			return false;
1541 		return (pmc->mca_sfmode == MCAST_INCLUDE) ^ sdeleted;
1542 	case MLD2_BLOCK_OLD_SOURCES:
1543 		if (pmc->mca_sfmode == MCAST_INCLUDE)
1544 			return gdeleted || (psf->sf_crcount && sdeleted);
1545 		return psf->sf_crcount && !gdeleted && !sdeleted;
1546 	}
1547 	return false;
1548 }
1549 
1550 static int
1551 mld_scount(struct ifmcaddr6 *pmc, int type, int gdeleted, int sdeleted)
1552 {
1553 	struct ip6_sf_list *psf;
1554 	int scount = 0;
1555 
1556 	for (psf = pmc->mca_sources; psf; psf = psf->sf_next) {
1557 		if (!is_in(pmc, psf, type, gdeleted, sdeleted))
1558 			continue;
1559 		scount++;
1560 	}
1561 	return scount;
1562 }
1563 
1564 static void ip6_mc_hdr(struct sock *sk, struct sk_buff *skb,
1565 		       struct net_device *dev,
1566 		       const struct in6_addr *saddr,
1567 		       const struct in6_addr *daddr,
1568 		       int proto, int len)
1569 {
1570 	struct ipv6hdr *hdr;
1571 
1572 	skb->protocol = htons(ETH_P_IPV6);
1573 	skb->dev = dev;
1574 
1575 	skb_reset_network_header(skb);
1576 	skb_put(skb, sizeof(struct ipv6hdr));
1577 	hdr = ipv6_hdr(skb);
1578 
1579 	ip6_flow_hdr(hdr, 0, 0);
1580 
1581 	hdr->payload_len = htons(len);
1582 	hdr->nexthdr = proto;
1583 	hdr->hop_limit = inet6_sk(sk)->hop_limit;
1584 
1585 	hdr->saddr = *saddr;
1586 	hdr->daddr = *daddr;
1587 }
1588 
1589 static struct sk_buff *mld_newpack(struct inet6_dev *idev, unsigned int mtu)
1590 {
1591 	struct net_device *dev = idev->dev;
1592 	struct net *net = dev_net(dev);
1593 	struct sock *sk = net->ipv6.igmp_sk;
1594 	struct sk_buff *skb;
1595 	struct mld2_report *pmr;
1596 	struct in6_addr addr_buf;
1597 	const struct in6_addr *saddr;
1598 	int hlen = LL_RESERVED_SPACE(dev);
1599 	int tlen = dev->needed_tailroom;
1600 	unsigned int size = mtu + hlen + tlen;
1601 	int err;
1602 	u8 ra[8] = { IPPROTO_ICMPV6, 0,
1603 		     IPV6_TLV_ROUTERALERT, 2, 0, 0,
1604 		     IPV6_TLV_PADN, 0 };
1605 
1606 	/* we assume size > sizeof(ra) here */
1607 	/* limit our allocations to order-0 page */
1608 	size = min_t(int, size, SKB_MAX_ORDER(0, 0));
1609 	skb = sock_alloc_send_skb(sk, size, 1, &err);
1610 
1611 	if (!skb)
1612 		return NULL;
1613 
1614 	skb->priority = TC_PRIO_CONTROL;
1615 	skb_reserve(skb, hlen);
1616 	skb_tailroom_reserve(skb, mtu, tlen);
1617 
1618 	if (__ipv6_get_lladdr(idev, &addr_buf, IFA_F_TENTATIVE)) {
1619 		/* <draft-ietf-magma-mld-source-05.txt>:
1620 		 * use unspecified address as the source address
1621 		 * when a valid link-local address is not available.
1622 		 */
1623 		saddr = &in6addr_any;
1624 	} else
1625 		saddr = &addr_buf;
1626 
1627 	ip6_mc_hdr(sk, skb, dev, saddr, &mld2_all_mcr, NEXTHDR_HOP, 0);
1628 
1629 	skb_put_data(skb, ra, sizeof(ra));
1630 
1631 	skb_set_transport_header(skb, skb_tail_pointer(skb) - skb->data);
1632 	skb_put(skb, sizeof(*pmr));
1633 	pmr = (struct mld2_report *)skb_transport_header(skb);
1634 	pmr->mld2r_type = ICMPV6_MLD2_REPORT;
1635 	pmr->mld2r_resv1 = 0;
1636 	pmr->mld2r_cksum = 0;
1637 	pmr->mld2r_resv2 = 0;
1638 	pmr->mld2r_ngrec = 0;
1639 	return skb;
1640 }
1641 
1642 static void mld_sendpack(struct sk_buff *skb)
1643 {
1644 	struct ipv6hdr *pip6 = ipv6_hdr(skb);
1645 	struct mld2_report *pmr =
1646 			      (struct mld2_report *)skb_transport_header(skb);
1647 	int payload_len, mldlen;
1648 	struct inet6_dev *idev;
1649 	struct net *net = dev_net(skb->dev);
1650 	int err;
1651 	struct flowi6 fl6;
1652 	struct dst_entry *dst;
1653 
1654 	rcu_read_lock();
1655 	idev = __in6_dev_get(skb->dev);
1656 	IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
1657 
1658 	payload_len = (skb_tail_pointer(skb) - skb_network_header(skb)) -
1659 		sizeof(*pip6);
1660 	mldlen = skb_tail_pointer(skb) - skb_transport_header(skb);
1661 	pip6->payload_len = htons(payload_len);
1662 
1663 	pmr->mld2r_cksum = csum_ipv6_magic(&pip6->saddr, &pip6->daddr, mldlen,
1664 					   IPPROTO_ICMPV6,
1665 					   csum_partial(skb_transport_header(skb),
1666 							mldlen, 0));
1667 
1668 	icmpv6_flow_init(net->ipv6.igmp_sk, &fl6, ICMPV6_MLD2_REPORT,
1669 			 &ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
1670 			 skb->dev->ifindex);
1671 	dst = icmp6_dst_alloc(skb->dev, &fl6);
1672 
1673 	err = 0;
1674 	if (IS_ERR(dst)) {
1675 		err = PTR_ERR(dst);
1676 		dst = NULL;
1677 	}
1678 	skb_dst_set(skb, dst);
1679 	if (err)
1680 		goto err_out;
1681 
1682 	err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
1683 		      net, net->ipv6.igmp_sk, skb, NULL, skb->dev,
1684 		      dst_output);
1685 out:
1686 	if (!err) {
1687 		ICMP6MSGOUT_INC_STATS(net, idev, ICMPV6_MLD2_REPORT);
1688 		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
1689 	} else {
1690 		IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
1691 	}
1692 
1693 	rcu_read_unlock();
1694 	return;
1695 
1696 err_out:
1697 	kfree_skb(skb);
1698 	goto out;
1699 }
1700 
1701 static int grec_size(struct ifmcaddr6 *pmc, int type, int gdel, int sdel)
1702 {
1703 	return sizeof(struct mld2_grec) + 16 * mld_scount(pmc,type,gdel,sdel);
1704 }
1705 
1706 static struct sk_buff *add_grhead(struct sk_buff *skb, struct ifmcaddr6 *pmc,
1707 	int type, struct mld2_grec **ppgr, unsigned int mtu)
1708 {
1709 	struct mld2_report *pmr;
1710 	struct mld2_grec *pgr;
1711 
1712 	if (!skb) {
1713 		skb = mld_newpack(pmc->idev, mtu);
1714 		if (!skb)
1715 			return NULL;
1716 	}
1717 	pgr = skb_put(skb, sizeof(struct mld2_grec));
1718 	pgr->grec_type = type;
1719 	pgr->grec_auxwords = 0;
1720 	pgr->grec_nsrcs = 0;
1721 	pgr->grec_mca = pmc->mca_addr;	/* structure copy */
1722 	pmr = (struct mld2_report *)skb_transport_header(skb);
1723 	pmr->mld2r_ngrec = htons(ntohs(pmr->mld2r_ngrec)+1);
1724 	*ppgr = pgr;
1725 	return skb;
1726 }
1727 
1728 #define AVAILABLE(skb)	((skb) ? skb_availroom(skb) : 0)
1729 
1730 static struct sk_buff *add_grec(struct sk_buff *skb, struct ifmcaddr6 *pmc,
1731 	int type, int gdeleted, int sdeleted, int crsend)
1732 {
1733 	struct inet6_dev *idev = pmc->idev;
1734 	struct net_device *dev = idev->dev;
1735 	struct mld2_report *pmr;
1736 	struct mld2_grec *pgr = NULL;
1737 	struct ip6_sf_list *psf, *psf_next, *psf_prev, **psf_list;
1738 	int scount, stotal, first, isquery, truncate;
1739 	unsigned int mtu;
1740 
1741 	if (pmc->mca_flags & MAF_NOREPORT)
1742 		return skb;
1743 
1744 	mtu = READ_ONCE(dev->mtu);
1745 	if (mtu < IPV6_MIN_MTU)
1746 		return skb;
1747 
1748 	isquery = type == MLD2_MODE_IS_INCLUDE ||
1749 		  type == MLD2_MODE_IS_EXCLUDE;
1750 	truncate = type == MLD2_MODE_IS_EXCLUDE ||
1751 		    type == MLD2_CHANGE_TO_EXCLUDE;
1752 
1753 	stotal = scount = 0;
1754 
1755 	psf_list = sdeleted ? &pmc->mca_tomb : &pmc->mca_sources;
1756 
1757 	if (!*psf_list)
1758 		goto empty_source;
1759 
1760 	pmr = skb ? (struct mld2_report *)skb_transport_header(skb) : NULL;
1761 
1762 	/* EX and TO_EX get a fresh packet, if needed */
1763 	if (truncate) {
1764 		if (pmr && pmr->mld2r_ngrec &&
1765 		    AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) {
1766 			if (skb)
1767 				mld_sendpack(skb);
1768 			skb = mld_newpack(idev, mtu);
1769 		}
1770 	}
1771 	first = 1;
1772 	psf_prev = NULL;
1773 	for (psf = *psf_list; psf; psf = psf_next) {
1774 		struct in6_addr *psrc;
1775 
1776 		psf_next = psf->sf_next;
1777 
1778 		if (!is_in(pmc, psf, type, gdeleted, sdeleted) && !crsend) {
1779 			psf_prev = psf;
1780 			continue;
1781 		}
1782 
1783 		/* Based on RFC3810 6.1. Should not send source-list change
1784 		 * records when there is a filter mode change.
1785 		 */
1786 		if (((gdeleted && pmc->mca_sfmode == MCAST_EXCLUDE) ||
1787 		     (!gdeleted && pmc->mca_crcount)) &&
1788 		    (type == MLD2_ALLOW_NEW_SOURCES ||
1789 		     type == MLD2_BLOCK_OLD_SOURCES) && psf->sf_crcount)
1790 			goto decrease_sf_crcount;
1791 
1792 		/* clear marks on query responses */
1793 		if (isquery)
1794 			psf->sf_gsresp = 0;
1795 
1796 		if (AVAILABLE(skb) < sizeof(*psrc) +
1797 		    first*sizeof(struct mld2_grec)) {
1798 			if (truncate && !first)
1799 				break;	 /* truncate these */
1800 			if (pgr)
1801 				pgr->grec_nsrcs = htons(scount);
1802 			if (skb)
1803 				mld_sendpack(skb);
1804 			skb = mld_newpack(idev, mtu);
1805 			first = 1;
1806 			scount = 0;
1807 		}
1808 		if (first) {
1809 			skb = add_grhead(skb, pmc, type, &pgr, mtu);
1810 			first = 0;
1811 		}
1812 		if (!skb)
1813 			return NULL;
1814 		psrc = skb_put(skb, sizeof(*psrc));
1815 		*psrc = psf->sf_addr;
1816 		scount++; stotal++;
1817 		if ((type == MLD2_ALLOW_NEW_SOURCES ||
1818 		     type == MLD2_BLOCK_OLD_SOURCES) && psf->sf_crcount) {
1819 decrease_sf_crcount:
1820 			psf->sf_crcount--;
1821 			if ((sdeleted || gdeleted) && psf->sf_crcount == 0) {
1822 				if (psf_prev)
1823 					psf_prev->sf_next = psf->sf_next;
1824 				else
1825 					*psf_list = psf->sf_next;
1826 				kfree(psf);
1827 				continue;
1828 			}
1829 		}
1830 		psf_prev = psf;
1831 	}
1832 
1833 empty_source:
1834 	if (!stotal) {
1835 		if (type == MLD2_ALLOW_NEW_SOURCES ||
1836 		    type == MLD2_BLOCK_OLD_SOURCES)
1837 			return skb;
1838 		if (pmc->mca_crcount || isquery || crsend) {
1839 			/* make sure we have room for group header */
1840 			if (skb && AVAILABLE(skb) < sizeof(struct mld2_grec)) {
1841 				mld_sendpack(skb);
1842 				skb = NULL; /* add_grhead will get a new one */
1843 			}
1844 			skb = add_grhead(skb, pmc, type, &pgr, mtu);
1845 		}
1846 	}
1847 	if (pgr)
1848 		pgr->grec_nsrcs = htons(scount);
1849 
1850 	if (isquery)
1851 		pmc->mca_flags &= ~MAF_GSQUERY;	/* clear query state */
1852 	return skb;
1853 }
1854 
1855 static void mld_send_report(struct inet6_dev *idev, struct ifmcaddr6 *pmc)
1856 {
1857 	struct sk_buff *skb = NULL;
1858 	int type;
1859 
1860 	read_lock_bh(&idev->lock);
1861 	if (!pmc) {
1862 		for (pmc = idev->mc_list; pmc; pmc = pmc->next) {
1863 			if (pmc->mca_flags & MAF_NOREPORT)
1864 				continue;
1865 			spin_lock_bh(&pmc->mca_lock);
1866 			if (pmc->mca_sfcount[MCAST_EXCLUDE])
1867 				type = MLD2_MODE_IS_EXCLUDE;
1868 			else
1869 				type = MLD2_MODE_IS_INCLUDE;
1870 			skb = add_grec(skb, pmc, type, 0, 0, 0);
1871 			spin_unlock_bh(&pmc->mca_lock);
1872 		}
1873 	} else {
1874 		spin_lock_bh(&pmc->mca_lock);
1875 		if (pmc->mca_sfcount[MCAST_EXCLUDE])
1876 			type = MLD2_MODE_IS_EXCLUDE;
1877 		else
1878 			type = MLD2_MODE_IS_INCLUDE;
1879 		skb = add_grec(skb, pmc, type, 0, 0, 0);
1880 		spin_unlock_bh(&pmc->mca_lock);
1881 	}
1882 	read_unlock_bh(&idev->lock);
1883 	if (skb)
1884 		mld_sendpack(skb);
1885 }
1886 
1887 /*
1888  * remove zero-count source records from a source filter list
1889  */
1890 static void mld_clear_zeros(struct ip6_sf_list **ppsf)
1891 {
1892 	struct ip6_sf_list *psf_prev, *psf_next, *psf;
1893 
1894 	psf_prev = NULL;
1895 	for (psf = *ppsf; psf; psf = psf_next) {
1896 		psf_next = psf->sf_next;
1897 		if (psf->sf_crcount == 0) {
1898 			if (psf_prev)
1899 				psf_prev->sf_next = psf->sf_next;
1900 			else
1901 				*ppsf = psf->sf_next;
1902 			kfree(psf);
1903 		} else
1904 			psf_prev = psf;
1905 	}
1906 }
1907 
1908 static void mld_send_cr(struct inet6_dev *idev)
1909 {
1910 	struct ifmcaddr6 *pmc, *pmc_prev, *pmc_next;
1911 	struct sk_buff *skb = NULL;
1912 	int type, dtype;
1913 
1914 	read_lock_bh(&idev->lock);
1915 	spin_lock(&idev->mc_lock);
1916 
1917 	/* deleted MCA's */
1918 	pmc_prev = NULL;
1919 	for (pmc = idev->mc_tomb; pmc; pmc = pmc_next) {
1920 		pmc_next = pmc->next;
1921 		if (pmc->mca_sfmode == MCAST_INCLUDE) {
1922 			type = MLD2_BLOCK_OLD_SOURCES;
1923 			dtype = MLD2_BLOCK_OLD_SOURCES;
1924 			skb = add_grec(skb, pmc, type, 1, 0, 0);
1925 			skb = add_grec(skb, pmc, dtype, 1, 1, 0);
1926 		}
1927 		if (pmc->mca_crcount) {
1928 			if (pmc->mca_sfmode == MCAST_EXCLUDE) {
1929 				type = MLD2_CHANGE_TO_INCLUDE;
1930 				skb = add_grec(skb, pmc, type, 1, 0, 0);
1931 			}
1932 			pmc->mca_crcount--;
1933 			if (pmc->mca_crcount == 0) {
1934 				mld_clear_zeros(&pmc->mca_tomb);
1935 				mld_clear_zeros(&pmc->mca_sources);
1936 			}
1937 		}
1938 		if (pmc->mca_crcount == 0 && !pmc->mca_tomb &&
1939 		    !pmc->mca_sources) {
1940 			if (pmc_prev)
1941 				pmc_prev->next = pmc_next;
1942 			else
1943 				idev->mc_tomb = pmc_next;
1944 			in6_dev_put(pmc->idev);
1945 			kfree(pmc);
1946 		} else
1947 			pmc_prev = pmc;
1948 	}
1949 	spin_unlock(&idev->mc_lock);
1950 
1951 	/* change recs */
1952 	for (pmc = idev->mc_list; pmc; pmc = pmc->next) {
1953 		spin_lock_bh(&pmc->mca_lock);
1954 		if (pmc->mca_sfcount[MCAST_EXCLUDE]) {
1955 			type = MLD2_BLOCK_OLD_SOURCES;
1956 			dtype = MLD2_ALLOW_NEW_SOURCES;
1957 		} else {
1958 			type = MLD2_ALLOW_NEW_SOURCES;
1959 			dtype = MLD2_BLOCK_OLD_SOURCES;
1960 		}
1961 		skb = add_grec(skb, pmc, type, 0, 0, 0);
1962 		skb = add_grec(skb, pmc, dtype, 0, 1, 0);	/* deleted sources */
1963 
1964 		/* filter mode changes */
1965 		if (pmc->mca_crcount) {
1966 			if (pmc->mca_sfmode == MCAST_EXCLUDE)
1967 				type = MLD2_CHANGE_TO_EXCLUDE;
1968 			else
1969 				type = MLD2_CHANGE_TO_INCLUDE;
1970 			skb = add_grec(skb, pmc, type, 0, 0, 0);
1971 			pmc->mca_crcount--;
1972 		}
1973 		spin_unlock_bh(&pmc->mca_lock);
1974 	}
1975 	read_unlock_bh(&idev->lock);
1976 	if (!skb)
1977 		return;
1978 	(void) mld_sendpack(skb);
1979 }
1980 
1981 static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
1982 {
1983 	struct net *net = dev_net(dev);
1984 	struct sock *sk = net->ipv6.igmp_sk;
1985 	struct inet6_dev *idev;
1986 	struct sk_buff *skb;
1987 	struct mld_msg *hdr;
1988 	const struct in6_addr *snd_addr, *saddr;
1989 	struct in6_addr addr_buf;
1990 	int hlen = LL_RESERVED_SPACE(dev);
1991 	int tlen = dev->needed_tailroom;
1992 	int err, len, payload_len, full_len;
1993 	u8 ra[8] = { IPPROTO_ICMPV6, 0,
1994 		     IPV6_TLV_ROUTERALERT, 2, 0, 0,
1995 		     IPV6_TLV_PADN, 0 };
1996 	struct flowi6 fl6;
1997 	struct dst_entry *dst;
1998 
1999 	if (type == ICMPV6_MGM_REDUCTION)
2000 		snd_addr = &in6addr_linklocal_allrouters;
2001 	else
2002 		snd_addr = addr;
2003 
2004 	len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
2005 	payload_len = len + sizeof(ra);
2006 	full_len = sizeof(struct ipv6hdr) + payload_len;
2007 
2008 	rcu_read_lock();
2009 	IP6_UPD_PO_STATS(net, __in6_dev_get(dev),
2010 		      IPSTATS_MIB_OUT, full_len);
2011 	rcu_read_unlock();
2012 
2013 	skb = sock_alloc_send_skb(sk, hlen + tlen + full_len, 1, &err);
2014 
2015 	if (!skb) {
2016 		rcu_read_lock();
2017 		IP6_INC_STATS(net, __in6_dev_get(dev),
2018 			      IPSTATS_MIB_OUTDISCARDS);
2019 		rcu_read_unlock();
2020 		return;
2021 	}
2022 	skb->priority = TC_PRIO_CONTROL;
2023 	skb_reserve(skb, hlen);
2024 
2025 	if (ipv6_get_lladdr(dev, &addr_buf, IFA_F_TENTATIVE)) {
2026 		/* <draft-ietf-magma-mld-source-05.txt>:
2027 		 * use unspecified address as the source address
2028 		 * when a valid link-local address is not available.
2029 		 */
2030 		saddr = &in6addr_any;
2031 	} else
2032 		saddr = &addr_buf;
2033 
2034 	ip6_mc_hdr(sk, skb, dev, saddr, snd_addr, NEXTHDR_HOP, payload_len);
2035 
2036 	skb_put_data(skb, ra, sizeof(ra));
2037 
2038 	hdr = skb_put_zero(skb, sizeof(struct mld_msg));
2039 	hdr->mld_type = type;
2040 	hdr->mld_mca = *addr;
2041 
2042 	hdr->mld_cksum = csum_ipv6_magic(saddr, snd_addr, len,
2043 					 IPPROTO_ICMPV6,
2044 					 csum_partial(hdr, len, 0));
2045 
2046 	rcu_read_lock();
2047 	idev = __in6_dev_get(skb->dev);
2048 
2049 	icmpv6_flow_init(sk, &fl6, type,
2050 			 &ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
2051 			 skb->dev->ifindex);
2052 	dst = icmp6_dst_alloc(skb->dev, &fl6);
2053 	if (IS_ERR(dst)) {
2054 		err = PTR_ERR(dst);
2055 		goto err_out;
2056 	}
2057 
2058 	skb_dst_set(skb, dst);
2059 	err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
2060 		      net, sk, skb, NULL, skb->dev,
2061 		      dst_output);
2062 out:
2063 	if (!err) {
2064 		ICMP6MSGOUT_INC_STATS(net, idev, type);
2065 		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
2066 	} else
2067 		IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
2068 
2069 	rcu_read_unlock();
2070 	return;
2071 
2072 err_out:
2073 	kfree_skb(skb);
2074 	goto out;
2075 }
2076 
2077 static void mld_send_initial_cr(struct inet6_dev *idev)
2078 {
2079 	struct sk_buff *skb;
2080 	struct ifmcaddr6 *pmc;
2081 	int type;
2082 
2083 	if (mld_in_v1_mode(idev))
2084 		return;
2085 
2086 	skb = NULL;
2087 	read_lock_bh(&idev->lock);
2088 	for (pmc = idev->mc_list; pmc; pmc = pmc->next) {
2089 		spin_lock_bh(&pmc->mca_lock);
2090 		if (pmc->mca_sfcount[MCAST_EXCLUDE])
2091 			type = MLD2_CHANGE_TO_EXCLUDE;
2092 		else
2093 			type = MLD2_ALLOW_NEW_SOURCES;
2094 		skb = add_grec(skb, pmc, type, 0, 0, 1);
2095 		spin_unlock_bh(&pmc->mca_lock);
2096 	}
2097 	read_unlock_bh(&idev->lock);
2098 	if (skb)
2099 		mld_sendpack(skb);
2100 }
2101 
2102 void ipv6_mc_dad_complete(struct inet6_dev *idev)
2103 {
2104 	idev->mc_dad_count = idev->mc_qrv;
2105 	if (idev->mc_dad_count) {
2106 		mld_send_initial_cr(idev);
2107 		idev->mc_dad_count--;
2108 		if (idev->mc_dad_count)
2109 			mld_dad_start_timer(idev,
2110 					    unsolicited_report_interval(idev));
2111 	}
2112 }
2113 
2114 static void mld_dad_timer_expire(struct timer_list *t)
2115 {
2116 	struct inet6_dev *idev = from_timer(idev, t, mc_dad_timer);
2117 
2118 	mld_send_initial_cr(idev);
2119 	if (idev->mc_dad_count) {
2120 		idev->mc_dad_count--;
2121 		if (idev->mc_dad_count)
2122 			mld_dad_start_timer(idev,
2123 					    unsolicited_report_interval(idev));
2124 	}
2125 	in6_dev_put(idev);
2126 }
2127 
2128 static int ip6_mc_del1_src(struct ifmcaddr6 *pmc, int sfmode,
2129 	const struct in6_addr *psfsrc)
2130 {
2131 	struct ip6_sf_list *psf, *psf_prev;
2132 	int rv = 0;
2133 
2134 	psf_prev = NULL;
2135 	for (psf = pmc->mca_sources; psf; psf = psf->sf_next) {
2136 		if (ipv6_addr_equal(&psf->sf_addr, psfsrc))
2137 			break;
2138 		psf_prev = psf;
2139 	}
2140 	if (!psf || psf->sf_count[sfmode] == 0) {
2141 		/* source filter not found, or count wrong =>  bug */
2142 		return -ESRCH;
2143 	}
2144 	psf->sf_count[sfmode]--;
2145 	if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) {
2146 		struct inet6_dev *idev = pmc->idev;
2147 
2148 		/* no more filters for this source */
2149 		if (psf_prev)
2150 			psf_prev->sf_next = psf->sf_next;
2151 		else
2152 			pmc->mca_sources = psf->sf_next;
2153 		if (psf->sf_oldin && !(pmc->mca_flags & MAF_NOREPORT) &&
2154 		    !mld_in_v1_mode(idev)) {
2155 			psf->sf_crcount = idev->mc_qrv;
2156 			psf->sf_next = pmc->mca_tomb;
2157 			pmc->mca_tomb = psf;
2158 			rv = 1;
2159 		} else
2160 			kfree(psf);
2161 	}
2162 	return rv;
2163 }
2164 
2165 static int ip6_mc_del_src(struct inet6_dev *idev, const struct in6_addr *pmca,
2166 			  int sfmode, int sfcount, const struct in6_addr *psfsrc,
2167 			  int delta)
2168 {
2169 	struct ifmcaddr6 *pmc;
2170 	int	changerec = 0;
2171 	int	i, err;
2172 
2173 	if (!idev)
2174 		return -ENODEV;
2175 	read_lock_bh(&idev->lock);
2176 	for (pmc = idev->mc_list; pmc; pmc = pmc->next) {
2177 		if (ipv6_addr_equal(pmca, &pmc->mca_addr))
2178 			break;
2179 	}
2180 	if (!pmc) {
2181 		/* MCA not found?? bug */
2182 		read_unlock_bh(&idev->lock);
2183 		return -ESRCH;
2184 	}
2185 	spin_lock_bh(&pmc->mca_lock);
2186 	sf_markstate(pmc);
2187 	if (!delta) {
2188 		if (!pmc->mca_sfcount[sfmode]) {
2189 			spin_unlock_bh(&pmc->mca_lock);
2190 			read_unlock_bh(&idev->lock);
2191 			return -EINVAL;
2192 		}
2193 		pmc->mca_sfcount[sfmode]--;
2194 	}
2195 	err = 0;
2196 	for (i = 0; i < sfcount; i++) {
2197 		int rv = ip6_mc_del1_src(pmc, sfmode, &psfsrc[i]);
2198 
2199 		changerec |= rv > 0;
2200 		if (!err && rv < 0)
2201 			err = rv;
2202 	}
2203 	if (pmc->mca_sfmode == MCAST_EXCLUDE &&
2204 	    pmc->mca_sfcount[MCAST_EXCLUDE] == 0 &&
2205 	    pmc->mca_sfcount[MCAST_INCLUDE]) {
2206 		struct ip6_sf_list *psf;
2207 
2208 		/* filter mode change */
2209 		pmc->mca_sfmode = MCAST_INCLUDE;
2210 		pmc->mca_crcount = idev->mc_qrv;
2211 		idev->mc_ifc_count = pmc->mca_crcount;
2212 		for (psf = pmc->mca_sources; psf; psf = psf->sf_next)
2213 			psf->sf_crcount = 0;
2214 		mld_ifc_event(pmc->idev);
2215 	} else if (sf_setstate(pmc) || changerec)
2216 		mld_ifc_event(pmc->idev);
2217 	spin_unlock_bh(&pmc->mca_lock);
2218 	read_unlock_bh(&idev->lock);
2219 	return err;
2220 }
2221 
2222 /*
2223  * Add multicast single-source filter to the interface list
2224  */
2225 static int ip6_mc_add1_src(struct ifmcaddr6 *pmc, int sfmode,
2226 	const struct in6_addr *psfsrc)
2227 {
2228 	struct ip6_sf_list *psf, *psf_prev;
2229 
2230 	psf_prev = NULL;
2231 	for (psf = pmc->mca_sources; psf; psf = psf->sf_next) {
2232 		if (ipv6_addr_equal(&psf->sf_addr, psfsrc))
2233 			break;
2234 		psf_prev = psf;
2235 	}
2236 	if (!psf) {
2237 		psf = kzalloc(sizeof(*psf), GFP_ATOMIC);
2238 		if (!psf)
2239 			return -ENOBUFS;
2240 
2241 		psf->sf_addr = *psfsrc;
2242 		if (psf_prev) {
2243 			psf_prev->sf_next = psf;
2244 		} else
2245 			pmc->mca_sources = psf;
2246 	}
2247 	psf->sf_count[sfmode]++;
2248 	return 0;
2249 }
2250 
2251 static void sf_markstate(struct ifmcaddr6 *pmc)
2252 {
2253 	struct ip6_sf_list *psf;
2254 	int mca_xcount = pmc->mca_sfcount[MCAST_EXCLUDE];
2255 
2256 	for (psf = pmc->mca_sources; psf; psf = psf->sf_next)
2257 		if (pmc->mca_sfcount[MCAST_EXCLUDE]) {
2258 			psf->sf_oldin = mca_xcount ==
2259 				psf->sf_count[MCAST_EXCLUDE] &&
2260 				!psf->sf_count[MCAST_INCLUDE];
2261 		} else
2262 			psf->sf_oldin = psf->sf_count[MCAST_INCLUDE] != 0;
2263 }
2264 
2265 static int sf_setstate(struct ifmcaddr6 *pmc)
2266 {
2267 	struct ip6_sf_list *psf, *dpsf;
2268 	int mca_xcount = pmc->mca_sfcount[MCAST_EXCLUDE];
2269 	int qrv = pmc->idev->mc_qrv;
2270 	int new_in, rv;
2271 
2272 	rv = 0;
2273 	for (psf = pmc->mca_sources; psf; psf = psf->sf_next) {
2274 		if (pmc->mca_sfcount[MCAST_EXCLUDE]) {
2275 			new_in = mca_xcount == psf->sf_count[MCAST_EXCLUDE] &&
2276 				!psf->sf_count[MCAST_INCLUDE];
2277 		} else
2278 			new_in = psf->sf_count[MCAST_INCLUDE] != 0;
2279 		if (new_in) {
2280 			if (!psf->sf_oldin) {
2281 				struct ip6_sf_list *prev = NULL;
2282 
2283 				for (dpsf = pmc->mca_tomb; dpsf;
2284 				     dpsf = dpsf->sf_next) {
2285 					if (ipv6_addr_equal(&dpsf->sf_addr,
2286 					    &psf->sf_addr))
2287 						break;
2288 					prev = dpsf;
2289 				}
2290 				if (dpsf) {
2291 					if (prev)
2292 						prev->sf_next = dpsf->sf_next;
2293 					else
2294 						pmc->mca_tomb = dpsf->sf_next;
2295 					kfree(dpsf);
2296 				}
2297 				psf->sf_crcount = qrv;
2298 				rv++;
2299 			}
2300 		} else if (psf->sf_oldin) {
2301 			psf->sf_crcount = 0;
2302 			/*
2303 			 * add or update "delete" records if an active filter
2304 			 * is now inactive
2305 			 */
2306 			for (dpsf = pmc->mca_tomb; dpsf; dpsf = dpsf->sf_next)
2307 				if (ipv6_addr_equal(&dpsf->sf_addr,
2308 				    &psf->sf_addr))
2309 					break;
2310 			if (!dpsf) {
2311 				dpsf = kmalloc(sizeof(*dpsf), GFP_ATOMIC);
2312 				if (!dpsf)
2313 					continue;
2314 				*dpsf = *psf;
2315 				/* pmc->mca_lock held by callers */
2316 				dpsf->sf_next = pmc->mca_tomb;
2317 				pmc->mca_tomb = dpsf;
2318 			}
2319 			dpsf->sf_crcount = qrv;
2320 			rv++;
2321 		}
2322 	}
2323 	return rv;
2324 }
2325 
2326 /*
2327  * Add multicast source filter list to the interface list
2328  */
2329 static int ip6_mc_add_src(struct inet6_dev *idev, const struct in6_addr *pmca,
2330 			  int sfmode, int sfcount, const struct in6_addr *psfsrc,
2331 			  int delta)
2332 {
2333 	struct ifmcaddr6 *pmc;
2334 	int	isexclude;
2335 	int	i, err;
2336 
2337 	if (!idev)
2338 		return -ENODEV;
2339 	read_lock_bh(&idev->lock);
2340 	for (pmc = idev->mc_list; pmc; pmc = pmc->next) {
2341 		if (ipv6_addr_equal(pmca, &pmc->mca_addr))
2342 			break;
2343 	}
2344 	if (!pmc) {
2345 		/* MCA not found?? bug */
2346 		read_unlock_bh(&idev->lock);
2347 		return -ESRCH;
2348 	}
2349 	spin_lock_bh(&pmc->mca_lock);
2350 
2351 	sf_markstate(pmc);
2352 	isexclude = pmc->mca_sfmode == MCAST_EXCLUDE;
2353 	if (!delta)
2354 		pmc->mca_sfcount[sfmode]++;
2355 	err = 0;
2356 	for (i = 0; i < sfcount; i++) {
2357 		err = ip6_mc_add1_src(pmc, sfmode, &psfsrc[i]);
2358 		if (err)
2359 			break;
2360 	}
2361 	if (err) {
2362 		int j;
2363 
2364 		if (!delta)
2365 			pmc->mca_sfcount[sfmode]--;
2366 		for (j = 0; j < i; j++)
2367 			ip6_mc_del1_src(pmc, sfmode, &psfsrc[j]);
2368 	} else if (isexclude != (pmc->mca_sfcount[MCAST_EXCLUDE] != 0)) {
2369 		struct ip6_sf_list *psf;
2370 
2371 		/* filter mode change */
2372 		if (pmc->mca_sfcount[MCAST_EXCLUDE])
2373 			pmc->mca_sfmode = MCAST_EXCLUDE;
2374 		else if (pmc->mca_sfcount[MCAST_INCLUDE])
2375 			pmc->mca_sfmode = MCAST_INCLUDE;
2376 		/* else no filters; keep old mode for reports */
2377 
2378 		pmc->mca_crcount = idev->mc_qrv;
2379 		idev->mc_ifc_count = pmc->mca_crcount;
2380 		for (psf = pmc->mca_sources; psf; psf = psf->sf_next)
2381 			psf->sf_crcount = 0;
2382 		mld_ifc_event(idev);
2383 	} else if (sf_setstate(pmc))
2384 		mld_ifc_event(idev);
2385 	spin_unlock_bh(&pmc->mca_lock);
2386 	read_unlock_bh(&idev->lock);
2387 	return err;
2388 }
2389 
2390 static void ip6_mc_clear_src(struct ifmcaddr6 *pmc)
2391 {
2392 	struct ip6_sf_list *psf, *nextpsf;
2393 
2394 	for (psf = pmc->mca_tomb; psf; psf = nextpsf) {
2395 		nextpsf = psf->sf_next;
2396 		kfree(psf);
2397 	}
2398 	pmc->mca_tomb = NULL;
2399 	for (psf = pmc->mca_sources; psf; psf = nextpsf) {
2400 		nextpsf = psf->sf_next;
2401 		kfree(psf);
2402 	}
2403 	pmc->mca_sources = NULL;
2404 	pmc->mca_sfmode = MCAST_EXCLUDE;
2405 	pmc->mca_sfcount[MCAST_INCLUDE] = 0;
2406 	pmc->mca_sfcount[MCAST_EXCLUDE] = 1;
2407 }
2408 
2409 
2410 static void igmp6_join_group(struct ifmcaddr6 *ma)
2411 {
2412 	unsigned long delay;
2413 
2414 	if (ma->mca_flags & MAF_NOREPORT)
2415 		return;
2416 
2417 	igmp6_send(&ma->mca_addr, ma->idev->dev, ICMPV6_MGM_REPORT);
2418 
2419 	delay = prandom_u32() % unsolicited_report_interval(ma->idev);
2420 
2421 	spin_lock_bh(&ma->mca_lock);
2422 	if (del_timer(&ma->mca_timer)) {
2423 		refcount_dec(&ma->mca_refcnt);
2424 		delay = ma->mca_timer.expires - jiffies;
2425 	}
2426 
2427 	if (!mod_timer(&ma->mca_timer, jiffies + delay))
2428 		refcount_inc(&ma->mca_refcnt);
2429 	ma->mca_flags |= MAF_TIMER_RUNNING | MAF_LAST_REPORTER;
2430 	spin_unlock_bh(&ma->mca_lock);
2431 }
2432 
2433 static int ip6_mc_leave_src(struct sock *sk, struct ipv6_mc_socklist *iml,
2434 			    struct inet6_dev *idev)
2435 {
2436 	int err;
2437 
2438 	write_lock_bh(&iml->sflock);
2439 	if (!iml->sflist) {
2440 		/* any-source empty exclude case */
2441 		err = ip6_mc_del_src(idev, &iml->addr, iml->sfmode, 0, NULL, 0);
2442 	} else {
2443 		err = ip6_mc_del_src(idev, &iml->addr, iml->sfmode,
2444 				iml->sflist->sl_count, iml->sflist->sl_addr, 0);
2445 		sock_kfree_s(sk, iml->sflist, IP6_SFLSIZE(iml->sflist->sl_max));
2446 		iml->sflist = NULL;
2447 	}
2448 	write_unlock_bh(&iml->sflock);
2449 	return err;
2450 }
2451 
2452 static void igmp6_leave_group(struct ifmcaddr6 *ma)
2453 {
2454 	if (mld_in_v1_mode(ma->idev)) {
2455 		if (ma->mca_flags & MAF_LAST_REPORTER)
2456 			igmp6_send(&ma->mca_addr, ma->idev->dev,
2457 				ICMPV6_MGM_REDUCTION);
2458 	} else {
2459 		mld_add_delrec(ma->idev, ma);
2460 		mld_ifc_event(ma->idev);
2461 	}
2462 }
2463 
2464 static void mld_gq_timer_expire(struct timer_list *t)
2465 {
2466 	struct inet6_dev *idev = from_timer(idev, t, mc_gq_timer);
2467 
2468 	idev->mc_gq_running = 0;
2469 	mld_send_report(idev, NULL);
2470 	in6_dev_put(idev);
2471 }
2472 
2473 static void mld_ifc_timer_expire(struct timer_list *t)
2474 {
2475 	struct inet6_dev *idev = from_timer(idev, t, mc_ifc_timer);
2476 
2477 	mld_send_cr(idev);
2478 	if (idev->mc_ifc_count) {
2479 		idev->mc_ifc_count--;
2480 		if (idev->mc_ifc_count)
2481 			mld_ifc_start_timer(idev,
2482 					    unsolicited_report_interval(idev));
2483 	}
2484 	in6_dev_put(idev);
2485 }
2486 
2487 static void mld_ifc_event(struct inet6_dev *idev)
2488 {
2489 	if (mld_in_v1_mode(idev))
2490 		return;
2491 	idev->mc_ifc_count = idev->mc_qrv;
2492 	mld_ifc_start_timer(idev, 1);
2493 }
2494 
2495 static void igmp6_timer_handler(struct timer_list *t)
2496 {
2497 	struct ifmcaddr6 *ma = from_timer(ma, t, mca_timer);
2498 
2499 	if (mld_in_v1_mode(ma->idev))
2500 		igmp6_send(&ma->mca_addr, ma->idev->dev, ICMPV6_MGM_REPORT);
2501 	else
2502 		mld_send_report(ma->idev, ma);
2503 
2504 	spin_lock(&ma->mca_lock);
2505 	ma->mca_flags |=  MAF_LAST_REPORTER;
2506 	ma->mca_flags &= ~MAF_TIMER_RUNNING;
2507 	spin_unlock(&ma->mca_lock);
2508 	ma_put(ma);
2509 }
2510 
2511 /* Device changing type */
2512 
2513 void ipv6_mc_unmap(struct inet6_dev *idev)
2514 {
2515 	struct ifmcaddr6 *i;
2516 
2517 	/* Install multicast list, except for all-nodes (already installed) */
2518 
2519 	read_lock_bh(&idev->lock);
2520 	for (i = idev->mc_list; i; i = i->next)
2521 		igmp6_group_dropped(i);
2522 	read_unlock_bh(&idev->lock);
2523 }
2524 
2525 void ipv6_mc_remap(struct inet6_dev *idev)
2526 {
2527 	ipv6_mc_up(idev);
2528 }
2529 
2530 /* Device going down */
2531 
2532 void ipv6_mc_down(struct inet6_dev *idev)
2533 {
2534 	struct ifmcaddr6 *i;
2535 
2536 	/* Withdraw multicast list */
2537 
2538 	read_lock_bh(&idev->lock);
2539 
2540 	for (i = idev->mc_list; i; i = i->next)
2541 		igmp6_group_dropped(i);
2542 
2543 	/* Should stop timer after group drop. or we will
2544 	 * start timer again in mld_ifc_event()
2545 	 */
2546 	mld_ifc_stop_timer(idev);
2547 	mld_gq_stop_timer(idev);
2548 	mld_dad_stop_timer(idev);
2549 	read_unlock_bh(&idev->lock);
2550 }
2551 
2552 static void ipv6_mc_reset(struct inet6_dev *idev)
2553 {
2554 	idev->mc_qrv = sysctl_mld_qrv;
2555 	idev->mc_qi = MLD_QI_DEFAULT;
2556 	idev->mc_qri = MLD_QRI_DEFAULT;
2557 	idev->mc_v1_seen = 0;
2558 	idev->mc_maxdelay = unsolicited_report_interval(idev);
2559 }
2560 
2561 /* Device going up */
2562 
2563 void ipv6_mc_up(struct inet6_dev *idev)
2564 {
2565 	struct ifmcaddr6 *i;
2566 
2567 	/* Install multicast list, except for all-nodes (already installed) */
2568 
2569 	read_lock_bh(&idev->lock);
2570 	ipv6_mc_reset(idev);
2571 	for (i = idev->mc_list; i; i = i->next) {
2572 		mld_del_delrec(idev, i);
2573 		igmp6_group_added(i);
2574 	}
2575 	read_unlock_bh(&idev->lock);
2576 }
2577 
2578 /* IPv6 device initialization. */
2579 
2580 void ipv6_mc_init_dev(struct inet6_dev *idev)
2581 {
2582 	write_lock_bh(&idev->lock);
2583 	spin_lock_init(&idev->mc_lock);
2584 	idev->mc_gq_running = 0;
2585 	timer_setup(&idev->mc_gq_timer, mld_gq_timer_expire, 0);
2586 	idev->mc_tomb = NULL;
2587 	idev->mc_ifc_count = 0;
2588 	timer_setup(&idev->mc_ifc_timer, mld_ifc_timer_expire, 0);
2589 	timer_setup(&idev->mc_dad_timer, mld_dad_timer_expire, 0);
2590 	ipv6_mc_reset(idev);
2591 	write_unlock_bh(&idev->lock);
2592 }
2593 
2594 /*
2595  *	Device is about to be destroyed: clean up.
2596  */
2597 
2598 void ipv6_mc_destroy_dev(struct inet6_dev *idev)
2599 {
2600 	struct ifmcaddr6 *i;
2601 
2602 	/* Deactivate timers */
2603 	ipv6_mc_down(idev);
2604 	mld_clear_delrec(idev);
2605 
2606 	/* Delete all-nodes address. */
2607 	/* We cannot call ipv6_dev_mc_dec() directly, our caller in
2608 	 * addrconf.c has NULL'd out dev->ip6_ptr so in6_dev_get() will
2609 	 * fail.
2610 	 */
2611 	__ipv6_dev_mc_dec(idev, &in6addr_linklocal_allnodes);
2612 
2613 	if (idev->cnf.forwarding)
2614 		__ipv6_dev_mc_dec(idev, &in6addr_linklocal_allrouters);
2615 
2616 	write_lock_bh(&idev->lock);
2617 	while ((i = idev->mc_list) != NULL) {
2618 		idev->mc_list = i->next;
2619 
2620 		write_unlock_bh(&idev->lock);
2621 		ma_put(i);
2622 		write_lock_bh(&idev->lock);
2623 	}
2624 	write_unlock_bh(&idev->lock);
2625 }
2626 
2627 static void ipv6_mc_rejoin_groups(struct inet6_dev *idev)
2628 {
2629 	struct ifmcaddr6 *pmc;
2630 
2631 	ASSERT_RTNL();
2632 
2633 	if (mld_in_v1_mode(idev)) {
2634 		read_lock_bh(&idev->lock);
2635 		for (pmc = idev->mc_list; pmc; pmc = pmc->next)
2636 			igmp6_join_group(pmc);
2637 		read_unlock_bh(&idev->lock);
2638 	} else
2639 		mld_send_report(idev, NULL);
2640 }
2641 
2642 static int ipv6_mc_netdev_event(struct notifier_block *this,
2643 				unsigned long event,
2644 				void *ptr)
2645 {
2646 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
2647 	struct inet6_dev *idev = __in6_dev_get(dev);
2648 
2649 	switch (event) {
2650 	case NETDEV_RESEND_IGMP:
2651 		if (idev)
2652 			ipv6_mc_rejoin_groups(idev);
2653 		break;
2654 	default:
2655 		break;
2656 	}
2657 
2658 	return NOTIFY_DONE;
2659 }
2660 
2661 static struct notifier_block igmp6_netdev_notifier = {
2662 	.notifier_call = ipv6_mc_netdev_event,
2663 };
2664 
2665 #ifdef CONFIG_PROC_FS
2666 struct igmp6_mc_iter_state {
2667 	struct seq_net_private p;
2668 	struct net_device *dev;
2669 	struct inet6_dev *idev;
2670 };
2671 
2672 #define igmp6_mc_seq_private(seq)	((struct igmp6_mc_iter_state *)(seq)->private)
2673 
2674 static inline struct ifmcaddr6 *igmp6_mc_get_first(struct seq_file *seq)
2675 {
2676 	struct ifmcaddr6 *im = NULL;
2677 	struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq);
2678 	struct net *net = seq_file_net(seq);
2679 
2680 	state->idev = NULL;
2681 	for_each_netdev_rcu(net, state->dev) {
2682 		struct inet6_dev *idev;
2683 		idev = __in6_dev_get(state->dev);
2684 		if (!idev)
2685 			continue;
2686 		read_lock_bh(&idev->lock);
2687 		im = idev->mc_list;
2688 		if (im) {
2689 			state->idev = idev;
2690 			break;
2691 		}
2692 		read_unlock_bh(&idev->lock);
2693 	}
2694 	return im;
2695 }
2696 
2697 static struct ifmcaddr6 *igmp6_mc_get_next(struct seq_file *seq, struct ifmcaddr6 *im)
2698 {
2699 	struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq);
2700 
2701 	im = im->next;
2702 	while (!im) {
2703 		if (likely(state->idev))
2704 			read_unlock_bh(&state->idev->lock);
2705 
2706 		state->dev = next_net_device_rcu(state->dev);
2707 		if (!state->dev) {
2708 			state->idev = NULL;
2709 			break;
2710 		}
2711 		state->idev = __in6_dev_get(state->dev);
2712 		if (!state->idev)
2713 			continue;
2714 		read_lock_bh(&state->idev->lock);
2715 		im = state->idev->mc_list;
2716 	}
2717 	return im;
2718 }
2719 
2720 static struct ifmcaddr6 *igmp6_mc_get_idx(struct seq_file *seq, loff_t pos)
2721 {
2722 	struct ifmcaddr6 *im = igmp6_mc_get_first(seq);
2723 	if (im)
2724 		while (pos && (im = igmp6_mc_get_next(seq, im)) != NULL)
2725 			--pos;
2726 	return pos ? NULL : im;
2727 }
2728 
2729 static void *igmp6_mc_seq_start(struct seq_file *seq, loff_t *pos)
2730 	__acquires(RCU)
2731 {
2732 	rcu_read_lock();
2733 	return igmp6_mc_get_idx(seq, *pos);
2734 }
2735 
2736 static void *igmp6_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2737 {
2738 	struct ifmcaddr6 *im = igmp6_mc_get_next(seq, v);
2739 
2740 	++*pos;
2741 	return im;
2742 }
2743 
2744 static void igmp6_mc_seq_stop(struct seq_file *seq, void *v)
2745 	__releases(RCU)
2746 {
2747 	struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq);
2748 
2749 	if (likely(state->idev)) {
2750 		read_unlock_bh(&state->idev->lock);
2751 		state->idev = NULL;
2752 	}
2753 	state->dev = NULL;
2754 	rcu_read_unlock();
2755 }
2756 
2757 static int igmp6_mc_seq_show(struct seq_file *seq, void *v)
2758 {
2759 	struct ifmcaddr6 *im = (struct ifmcaddr6 *)v;
2760 	struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq);
2761 
2762 	seq_printf(seq,
2763 		   "%-4d %-15s %pi6 %5d %08X %ld\n",
2764 		   state->dev->ifindex, state->dev->name,
2765 		   &im->mca_addr,
2766 		   im->mca_users, im->mca_flags,
2767 		   (im->mca_flags&MAF_TIMER_RUNNING) ?
2768 		   jiffies_to_clock_t(im->mca_timer.expires-jiffies) : 0);
2769 	return 0;
2770 }
2771 
2772 static const struct seq_operations igmp6_mc_seq_ops = {
2773 	.start	=	igmp6_mc_seq_start,
2774 	.next	=	igmp6_mc_seq_next,
2775 	.stop	=	igmp6_mc_seq_stop,
2776 	.show	=	igmp6_mc_seq_show,
2777 };
2778 
2779 struct igmp6_mcf_iter_state {
2780 	struct seq_net_private p;
2781 	struct net_device *dev;
2782 	struct inet6_dev *idev;
2783 	struct ifmcaddr6 *im;
2784 };
2785 
2786 #define igmp6_mcf_seq_private(seq)	((struct igmp6_mcf_iter_state *)(seq)->private)
2787 
2788 static inline struct ip6_sf_list *igmp6_mcf_get_first(struct seq_file *seq)
2789 {
2790 	struct ip6_sf_list *psf = NULL;
2791 	struct ifmcaddr6 *im = NULL;
2792 	struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);
2793 	struct net *net = seq_file_net(seq);
2794 
2795 	state->idev = NULL;
2796 	state->im = NULL;
2797 	for_each_netdev_rcu(net, state->dev) {
2798 		struct inet6_dev *idev;
2799 		idev = __in6_dev_get(state->dev);
2800 		if (unlikely(idev == NULL))
2801 			continue;
2802 		read_lock_bh(&idev->lock);
2803 		im = idev->mc_list;
2804 		if (likely(im)) {
2805 			spin_lock_bh(&im->mca_lock);
2806 			psf = im->mca_sources;
2807 			if (likely(psf)) {
2808 				state->im = im;
2809 				state->idev = idev;
2810 				break;
2811 			}
2812 			spin_unlock_bh(&im->mca_lock);
2813 		}
2814 		read_unlock_bh(&idev->lock);
2815 	}
2816 	return psf;
2817 }
2818 
2819 static struct ip6_sf_list *igmp6_mcf_get_next(struct seq_file *seq, struct ip6_sf_list *psf)
2820 {
2821 	struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);
2822 
2823 	psf = psf->sf_next;
2824 	while (!psf) {
2825 		spin_unlock_bh(&state->im->mca_lock);
2826 		state->im = state->im->next;
2827 		while (!state->im) {
2828 			if (likely(state->idev))
2829 				read_unlock_bh(&state->idev->lock);
2830 
2831 			state->dev = next_net_device_rcu(state->dev);
2832 			if (!state->dev) {
2833 				state->idev = NULL;
2834 				goto out;
2835 			}
2836 			state->idev = __in6_dev_get(state->dev);
2837 			if (!state->idev)
2838 				continue;
2839 			read_lock_bh(&state->idev->lock);
2840 			state->im = state->idev->mc_list;
2841 		}
2842 		if (!state->im)
2843 			break;
2844 		spin_lock_bh(&state->im->mca_lock);
2845 		psf = state->im->mca_sources;
2846 	}
2847 out:
2848 	return psf;
2849 }
2850 
2851 static struct ip6_sf_list *igmp6_mcf_get_idx(struct seq_file *seq, loff_t pos)
2852 {
2853 	struct ip6_sf_list *psf = igmp6_mcf_get_first(seq);
2854 	if (psf)
2855 		while (pos && (psf = igmp6_mcf_get_next(seq, psf)) != NULL)
2856 			--pos;
2857 	return pos ? NULL : psf;
2858 }
2859 
2860 static void *igmp6_mcf_seq_start(struct seq_file *seq, loff_t *pos)
2861 	__acquires(RCU)
2862 {
2863 	rcu_read_lock();
2864 	return *pos ? igmp6_mcf_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2865 }
2866 
2867 static void *igmp6_mcf_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2868 {
2869 	struct ip6_sf_list *psf;
2870 	if (v == SEQ_START_TOKEN)
2871 		psf = igmp6_mcf_get_first(seq);
2872 	else
2873 		psf = igmp6_mcf_get_next(seq, v);
2874 	++*pos;
2875 	return psf;
2876 }
2877 
2878 static void igmp6_mcf_seq_stop(struct seq_file *seq, void *v)
2879 	__releases(RCU)
2880 {
2881 	struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);
2882 	if (likely(state->im)) {
2883 		spin_unlock_bh(&state->im->mca_lock);
2884 		state->im = NULL;
2885 	}
2886 	if (likely(state->idev)) {
2887 		read_unlock_bh(&state->idev->lock);
2888 		state->idev = NULL;
2889 	}
2890 	state->dev = NULL;
2891 	rcu_read_unlock();
2892 }
2893 
2894 static int igmp6_mcf_seq_show(struct seq_file *seq, void *v)
2895 {
2896 	struct ip6_sf_list *psf = (struct ip6_sf_list *)v;
2897 	struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);
2898 
2899 	if (v == SEQ_START_TOKEN) {
2900 		seq_puts(seq, "Idx Device                Multicast Address                   Source Address    INC    EXC\n");
2901 	} else {
2902 		seq_printf(seq,
2903 			   "%3d %6.6s %pi6 %pi6 %6lu %6lu\n",
2904 			   state->dev->ifindex, state->dev->name,
2905 			   &state->im->mca_addr,
2906 			   &psf->sf_addr,
2907 			   psf->sf_count[MCAST_INCLUDE],
2908 			   psf->sf_count[MCAST_EXCLUDE]);
2909 	}
2910 	return 0;
2911 }
2912 
2913 static const struct seq_operations igmp6_mcf_seq_ops = {
2914 	.start	=	igmp6_mcf_seq_start,
2915 	.next	=	igmp6_mcf_seq_next,
2916 	.stop	=	igmp6_mcf_seq_stop,
2917 	.show	=	igmp6_mcf_seq_show,
2918 };
2919 
2920 static int __net_init igmp6_proc_init(struct net *net)
2921 {
2922 	int err;
2923 
2924 	err = -ENOMEM;
2925 	if (!proc_create_net("igmp6", 0444, net->proc_net, &igmp6_mc_seq_ops,
2926 			sizeof(struct igmp6_mc_iter_state)))
2927 		goto out;
2928 	if (!proc_create_net("mcfilter6", 0444, net->proc_net,
2929 			&igmp6_mcf_seq_ops,
2930 			sizeof(struct igmp6_mcf_iter_state)))
2931 		goto out_proc_net_igmp6;
2932 
2933 	err = 0;
2934 out:
2935 	return err;
2936 
2937 out_proc_net_igmp6:
2938 	remove_proc_entry("igmp6", net->proc_net);
2939 	goto out;
2940 }
2941 
2942 static void __net_exit igmp6_proc_exit(struct net *net)
2943 {
2944 	remove_proc_entry("mcfilter6", net->proc_net);
2945 	remove_proc_entry("igmp6", net->proc_net);
2946 }
2947 #else
2948 static inline int igmp6_proc_init(struct net *net)
2949 {
2950 	return 0;
2951 }
2952 static inline void igmp6_proc_exit(struct net *net)
2953 {
2954 }
2955 #endif
2956 
2957 static int __net_init igmp6_net_init(struct net *net)
2958 {
2959 	int err;
2960 
2961 	err = inet_ctl_sock_create(&net->ipv6.igmp_sk, PF_INET6,
2962 				   SOCK_RAW, IPPROTO_ICMPV6, net);
2963 	if (err < 0) {
2964 		pr_err("Failed to initialize the IGMP6 control socket (err %d)\n",
2965 		       err);
2966 		goto out;
2967 	}
2968 
2969 	inet6_sk(net->ipv6.igmp_sk)->hop_limit = 1;
2970 
2971 	err = inet_ctl_sock_create(&net->ipv6.mc_autojoin_sk, PF_INET6,
2972 				   SOCK_RAW, IPPROTO_ICMPV6, net);
2973 	if (err < 0) {
2974 		pr_err("Failed to initialize the IGMP6 autojoin socket (err %d)\n",
2975 		       err);
2976 		goto out_sock_create;
2977 	}
2978 
2979 	err = igmp6_proc_init(net);
2980 	if (err)
2981 		goto out_sock_create_autojoin;
2982 
2983 	return 0;
2984 
2985 out_sock_create_autojoin:
2986 	inet_ctl_sock_destroy(net->ipv6.mc_autojoin_sk);
2987 out_sock_create:
2988 	inet_ctl_sock_destroy(net->ipv6.igmp_sk);
2989 out:
2990 	return err;
2991 }
2992 
2993 static void __net_exit igmp6_net_exit(struct net *net)
2994 {
2995 	inet_ctl_sock_destroy(net->ipv6.igmp_sk);
2996 	inet_ctl_sock_destroy(net->ipv6.mc_autojoin_sk);
2997 	igmp6_proc_exit(net);
2998 }
2999 
3000 static struct pernet_operations igmp6_net_ops = {
3001 	.init = igmp6_net_init,
3002 	.exit = igmp6_net_exit,
3003 };
3004 
3005 int __init igmp6_init(void)
3006 {
3007 	return register_pernet_subsys(&igmp6_net_ops);
3008 }
3009 
3010 int __init igmp6_late_init(void)
3011 {
3012 	return register_netdevice_notifier(&igmp6_netdev_notifier);
3013 }
3014 
3015 void igmp6_cleanup(void)
3016 {
3017 	unregister_pernet_subsys(&igmp6_net_ops);
3018 }
3019 
3020 void igmp6_late_cleanup(void)
3021 {
3022 	unregister_netdevice_notifier(&igmp6_netdev_notifier);
3023 }
3024