xref: /linux/net/ipv6/mcast.c (revision 1ea2f885a76bc261c5b81c4a01477eacf8025e30)
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/net.h>
33 #include <linux/in.h>
34 #include <linux/in6.h>
35 #include <linux/netdevice.h>
36 #include <linux/if_addr.h>
37 #include <linux/if_arp.h>
38 #include <linux/route.h>
39 #include <linux/rtnetlink.h>
40 #include <linux/init.h>
41 #include <linux/proc_fs.h>
42 #include <linux/seq_file.h>
43 #include <linux/slab.h>
44 #include <linux/pkt_sched.h>
45 #include <net/mld.h>
46 #include <linux/workqueue.h>
47 
48 #include <linux/netfilter.h>
49 #include <linux/netfilter_ipv6.h>
50 
51 #include <net/net_namespace.h>
52 #include <net/netlink.h>
53 #include <net/sock.h>
54 #include <net/snmp.h>
55 
56 #include <net/ipv6.h>
57 #include <net/protocol.h>
58 #include <net/if_inet6.h>
59 #include <net/ndisc.h>
60 #include <net/addrconf.h>
61 #include <net/ip6_route.h>
62 #include <net/inet_common.h>
63 
64 #include <net/ip6_checksum.h>
65 
66 /* Ensure that we have struct in6_addr aligned on 32bit word. */
67 static int __mld2_query_bugs[] __attribute__((__unused__)) = {
68 	BUILD_BUG_ON_ZERO(offsetof(struct mld2_query, mld2q_srcs) % 4),
69 	BUILD_BUG_ON_ZERO(offsetof(struct mld2_report, mld2r_grec) % 4),
70 	BUILD_BUG_ON_ZERO(offsetof(struct mld2_grec, grec_mca) % 4)
71 };
72 
73 static struct workqueue_struct *mld_wq;
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 mld_mca_work(struct work_struct *work);
79 
80 static void mld_ifc_event(struct inet6_dev *idev);
81 static bool mld_in_v1_mode(const struct inet6_dev *idev);
82 static int sf_setstate(struct ifmcaddr6 *pmc);
83 static void sf_markstate(struct ifmcaddr6 *pmc);
84 static void ip6_mc_clear_src(struct ifmcaddr6 *pmc);
85 static int ip6_mc_del_src(struct inet6_dev *idev, const struct in6_addr *pmca,
86 			  int sfmode, int sfcount, const struct in6_addr *psfsrc,
87 			  int delta);
88 static int ip6_mc_add_src(struct inet6_dev *idev, const struct in6_addr *pmca,
89 			  int sfmode, int sfcount, const struct in6_addr *psfsrc,
90 			  int delta);
91 static int ip6_mc_leave_src(struct sock *sk, struct ipv6_mc_socklist *iml,
92 			    struct inet6_dev *idev);
93 static int __ipv6_dev_mc_inc(struct net_device *dev,
94 			     const struct in6_addr *addr, unsigned int mode);
95 
96 #define MLD_QRV_DEFAULT		2
97 /* RFC3810, 9.2. Query Interval */
98 #define MLD_QI_DEFAULT		(125 * HZ)
99 /* RFC3810, 9.3. Query Response Interval */
100 #define MLD_QRI_DEFAULT		(10 * HZ)
101 
102 /* RFC3810, 8.1 Query Version Distinctions */
103 #define MLD_V1_QUERY_LEN	24
104 #define MLD_V2_QUERY_LEN_MIN	28
105 
106 #define IPV6_MLD_MAX_MSF	64
107 
108 int sysctl_mld_max_msf __read_mostly = IPV6_MLD_MAX_MSF;
109 int sysctl_mld_qrv __read_mostly = MLD_QRV_DEFAULT;
110 
111 #define mc_assert_locked(idev)			\
112 	lockdep_assert_held(&(idev)->mc_lock)
113 
114 #define mc_dereference(e, idev) \
115 	rcu_dereference_protected(e, lockdep_is_held(&(idev)->mc_lock))
116 
117 #define sock_dereference(e, sk) \
118 	rcu_dereference_protected(e, lockdep_sock_is_held(sk))
119 
120 #define for_each_pmc_socklock(np, sk, pmc)			\
121 	for (pmc = sock_dereference((np)->ipv6_mc_list, sk);	\
122 	     pmc;						\
123 	     pmc = sock_dereference(pmc->next, sk))
124 
125 #define for_each_pmc_rcu(np, pmc)				\
126 	for (pmc = rcu_dereference((np)->ipv6_mc_list);		\
127 	     pmc;						\
128 	     pmc = rcu_dereference(pmc->next))
129 
130 #define for_each_psf_mclock(mc, psf)				\
131 	for (psf = mc_dereference((mc)->mca_sources, mc->idev);	\
132 	     psf;						\
133 	     psf = mc_dereference(psf->sf_next, mc->idev))
134 
135 #define for_each_psf_rcu(mc, psf)				\
136 	for (psf = rcu_dereference((mc)->mca_sources);		\
137 	     psf;						\
138 	     psf = rcu_dereference(psf->sf_next))
139 
140 #define for_each_psf_tomb(mc, psf)				\
141 	for (psf = mc_dereference((mc)->mca_tomb, mc->idev);	\
142 	     psf;						\
143 	     psf = mc_dereference(psf->sf_next, mc->idev))
144 
145 #define for_each_mc_mclock(idev, mc)				\
146 	for (mc = mc_dereference((idev)->mc_list, idev);	\
147 	     mc;						\
148 	     mc = mc_dereference(mc->next, idev))
149 
150 #define for_each_mc_rcu(idev, mc)				\
151 	for (mc = rcu_dereference((idev)->mc_list);             \
152 	     mc;                                                \
153 	     mc = rcu_dereference(mc->next))
154 
155 #define for_each_mc_tomb(idev, mc)				\
156 	for (mc = mc_dereference((idev)->mc_tomb, idev);	\
157 	     mc;						\
158 	     mc = mc_dereference(mc->next, idev))
159 
160 static int unsolicited_report_interval(struct inet6_dev *idev)
161 {
162 	int iv;
163 
164 	if (mld_in_v1_mode(idev))
165 		iv = READ_ONCE(idev->cnf.mldv1_unsolicited_report_interval);
166 	else
167 		iv = READ_ONCE(idev->cnf.mldv2_unsolicited_report_interval);
168 
169 	return iv > 0 ? iv : 1;
170 }
171 
172 static struct net_device *ip6_mc_find_dev(struct net *net,
173 					  const struct in6_addr *group,
174 					  int ifindex)
175 {
176 	struct net_device *dev = NULL;
177 	struct rt6_info *rt;
178 
179 	if (ifindex == 0) {
180 		rcu_read_lock();
181 		rt = rt6_lookup(net, group, NULL, 0, NULL, 0);
182 		if (rt) {
183 			dev = dst_dev_rcu(&rt->dst);
184 			dev_hold(dev);
185 			ip6_rt_put(rt);
186 		}
187 		rcu_read_unlock();
188 	} else {
189 		dev = dev_get_by_index(net, ifindex);
190 	}
191 
192 	return dev;
193 }
194 
195 /*
196  *	socket join on multicast group
197  */
198 static int __ipv6_sock_mc_join(struct sock *sk, int ifindex,
199 			       const struct in6_addr *addr, unsigned int mode)
200 {
201 	struct ipv6_pinfo *np = inet6_sk(sk);
202 	struct ipv6_mc_socklist *mc_lst;
203 	struct net *net = sock_net(sk);
204 	struct net_device *dev = NULL;
205 	int err;
206 
207 	if (!ipv6_addr_is_multicast(addr))
208 		return -EINVAL;
209 
210 	for_each_pmc_socklock(np, sk, mc_lst) {
211 		if ((ifindex == 0 || mc_lst->ifindex == ifindex) &&
212 		    ipv6_addr_equal(&mc_lst->addr, addr))
213 			return -EADDRINUSE;
214 	}
215 
216 	mc_lst = sock_kmalloc(sk, sizeof(struct ipv6_mc_socklist), GFP_KERNEL);
217 	if (!mc_lst)
218 		return -ENOMEM;
219 
220 	mc_lst->next = NULL;
221 	mc_lst->addr = *addr;
222 
223 	dev = ip6_mc_find_dev(net, addr, ifindex);
224 	if (!dev) {
225 		sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
226 		return -ENODEV;
227 	}
228 
229 	mc_lst->ifindex = dev->ifindex;
230 	mc_lst->sfmode = mode;
231 	RCU_INIT_POINTER(mc_lst->sflist, NULL);
232 
233 	/* now add/increase the group membership on the device */
234 	err = __ipv6_dev_mc_inc(dev, addr, mode);
235 
236 	dev_put(dev);
237 
238 	if (err) {
239 		sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
240 		return err;
241 	}
242 
243 	mc_lst->next = np->ipv6_mc_list;
244 	rcu_assign_pointer(np->ipv6_mc_list, mc_lst);
245 
246 	return 0;
247 }
248 
249 int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
250 {
251 	return __ipv6_sock_mc_join(sk, ifindex, addr, MCAST_EXCLUDE);
252 }
253 EXPORT_SYMBOL(ipv6_sock_mc_join);
254 
255 int ipv6_sock_mc_join_ssm(struct sock *sk, int ifindex,
256 			  const struct in6_addr *addr, unsigned int mode)
257 {
258 	return __ipv6_sock_mc_join(sk, ifindex, addr, mode);
259 }
260 
261 /*
262  *	socket leave on multicast group
263  */
264 static void __ipv6_sock_mc_drop(struct sock *sk, struct ipv6_mc_socklist *mc_lst)
265 {
266 	struct net *net = sock_net(sk);
267 	struct net_device *dev;
268 
269 	dev = dev_get_by_index(net, mc_lst->ifindex);
270 	if (dev) {
271 		struct inet6_dev *idev = in6_dev_get(dev);
272 
273 		ip6_mc_leave_src(sk, mc_lst, idev);
274 
275 		if (idev) {
276 			__ipv6_dev_mc_dec(idev, &mc_lst->addr);
277 			in6_dev_put(idev);
278 		}
279 
280 		dev_put(dev);
281 	} else {
282 		ip6_mc_leave_src(sk, mc_lst, NULL);
283 	}
284 
285 	atomic_sub(sizeof(*mc_lst), &sk->sk_omem_alloc);
286 	kfree_rcu(mc_lst, rcu);
287 }
288 
289 int ipv6_sock_mc_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
290 {
291 	struct ipv6_pinfo *np = inet6_sk(sk);
292 	struct ipv6_mc_socklist __rcu **lnk;
293 	struct ipv6_mc_socklist *mc_lst;
294 
295 	if (!ipv6_addr_is_multicast(addr))
296 		return -EINVAL;
297 
298 	for (lnk = &np->ipv6_mc_list;
299 	     (mc_lst = sock_dereference(*lnk, sk)) != NULL;
300 	      lnk = &mc_lst->next) {
301 		if ((ifindex == 0 || mc_lst->ifindex == ifindex) &&
302 		    ipv6_addr_equal(&mc_lst->addr, addr)) {
303 			*lnk = mc_lst->next;
304 			__ipv6_sock_mc_drop(sk, mc_lst);
305 			return 0;
306 		}
307 	}
308 
309 	return -EADDRNOTAVAIL;
310 }
311 EXPORT_SYMBOL(ipv6_sock_mc_drop);
312 
313 static struct inet6_dev *ip6_mc_find_idev(struct net *net,
314 					  const struct in6_addr *group,
315 					  int ifindex)
316 {
317 	struct net_device *dev;
318 	struct inet6_dev *idev;
319 
320 	dev = ip6_mc_find_dev(net, group, ifindex);
321 	if (!dev)
322 		return NULL;
323 
324 	idev = in6_dev_get(dev);
325 	dev_put(dev);
326 
327 	return idev;
328 }
329 
330 void __ipv6_sock_mc_close(struct sock *sk)
331 {
332 	struct ipv6_pinfo *np = inet6_sk(sk);
333 	struct ipv6_mc_socklist *mc_lst;
334 
335 	while ((mc_lst = sock_dereference(np->ipv6_mc_list, sk)) != NULL) {
336 		np->ipv6_mc_list = mc_lst->next;
337 		__ipv6_sock_mc_drop(sk, mc_lst);
338 	}
339 }
340 
341 void ipv6_sock_mc_close(struct sock *sk)
342 {
343 	struct ipv6_pinfo *np = inet6_sk(sk);
344 
345 	if (!rcu_access_pointer(np->ipv6_mc_list))
346 		return;
347 
348 	lock_sock(sk);
349 	__ipv6_sock_mc_close(sk);
350 	release_sock(sk);
351 }
352 
353 int ip6_mc_source(int add, int omode, struct sock *sk,
354 		  struct group_source_req *pgsr)
355 {
356 	struct ipv6_pinfo *inet6 = inet6_sk(sk);
357 	struct in6_addr *source, *group;
358 	struct net *net = sock_net(sk);
359 	struct ipv6_mc_socklist *pmc;
360 	struct ip6_sf_socklist *psl;
361 	struct inet6_dev *idev;
362 	int leavegroup = 0;
363 	int i, j, rv;
364 	int err;
365 
366 	source = &((struct sockaddr_in6 *)&pgsr->gsr_source)->sin6_addr;
367 	group = &((struct sockaddr_in6 *)&pgsr->gsr_group)->sin6_addr;
368 
369 	if (!ipv6_addr_is_multicast(group))
370 		return -EINVAL;
371 
372 	idev = ip6_mc_find_idev(net, group, pgsr->gsr_interface);
373 	if (!idev)
374 		return -ENODEV;
375 
376 	mutex_lock(&idev->mc_lock);
377 
378 	if (idev->dead) {
379 		err = -ENODEV;
380 		goto done;
381 	}
382 
383 	err = -EADDRNOTAVAIL;
384 
385 	for_each_pmc_socklock(inet6, sk, pmc) {
386 		if (pgsr->gsr_interface && pmc->ifindex != pgsr->gsr_interface)
387 			continue;
388 		if (ipv6_addr_equal(&pmc->addr, group))
389 			break;
390 	}
391 	if (!pmc) {		/* must have a prior join */
392 		err = -EINVAL;
393 		goto done;
394 	}
395 	/* if a source filter was set, must be the same mode as before */
396 	if (rcu_access_pointer(pmc->sflist)) {
397 		if (pmc->sfmode != omode) {
398 			err = -EINVAL;
399 			goto done;
400 		}
401 	} else if (pmc->sfmode != omode) {
402 		/* allow mode switches for empty-set filters */
403 		ip6_mc_add_src(idev, group, omode, 0, NULL, 0);
404 		ip6_mc_del_src(idev, group, pmc->sfmode, 0, NULL, 0);
405 		pmc->sfmode = omode;
406 	}
407 
408 	psl = sock_dereference(pmc->sflist, sk);
409 	if (!add) {
410 		if (!psl)
411 			goto done;	/* err = -EADDRNOTAVAIL */
412 		rv = !0;
413 		for (i = 0; i < psl->sl_count; i++) {
414 			rv = !ipv6_addr_equal(&psl->sl_addr[i], source);
415 			if (rv == 0)
416 				break;
417 		}
418 		if (rv)		/* source not found */
419 			goto done;	/* err = -EADDRNOTAVAIL */
420 
421 		/* special case - (INCLUDE, empty) == LEAVE_GROUP */
422 		if (psl->sl_count == 1 && omode == MCAST_INCLUDE) {
423 			leavegroup = 1;
424 			goto done;
425 		}
426 
427 		/* update the interface filter */
428 		ip6_mc_del_src(idev, group, omode, 1, source, 1);
429 
430 		for (j = i+1; j < psl->sl_count; j++)
431 			psl->sl_addr[j-1] = psl->sl_addr[j];
432 		psl->sl_count--;
433 		err = 0;
434 		goto done;
435 	}
436 	/* else, add a new source to the filter */
437 
438 	if (psl && psl->sl_count >= sysctl_mld_max_msf) {
439 		err = -ENOBUFS;
440 		goto done;
441 	}
442 	if (!psl || psl->sl_count == psl->sl_max) {
443 		struct ip6_sf_socklist *newpsl;
444 		int count = IP6_SFBLOCK;
445 
446 		if (psl)
447 			count += psl->sl_max;
448 		newpsl = sock_kmalloc(sk, struct_size(newpsl, sl_addr, count),
449 				      GFP_KERNEL);
450 		if (!newpsl) {
451 			err = -ENOBUFS;
452 			goto done;
453 		}
454 		newpsl->sl_max = count;
455 		newpsl->sl_count = count - IP6_SFBLOCK;
456 		if (psl) {
457 			for (i = 0; i < psl->sl_count; i++)
458 				newpsl->sl_addr[i] = psl->sl_addr[i];
459 			atomic_sub(struct_size(psl, sl_addr, psl->sl_max),
460 				   &sk->sk_omem_alloc);
461 		}
462 		rcu_assign_pointer(pmc->sflist, newpsl);
463 		kfree_rcu(psl, rcu);
464 		psl = newpsl;
465 	}
466 	rv = 1;	/* > 0 for insert logic below if sl_count is 0 */
467 	for (i = 0; i < psl->sl_count; i++) {
468 		rv = !ipv6_addr_equal(&psl->sl_addr[i], source);
469 		if (rv == 0) /* There is an error in the address. */
470 			goto done;
471 	}
472 	for (j = psl->sl_count-1; j >= i; j--)
473 		psl->sl_addr[j+1] = psl->sl_addr[j];
474 	psl->sl_addr[i] = *source;
475 	psl->sl_count++;
476 	err = 0;
477 	/* update the interface list */
478 	ip6_mc_add_src(idev, group, omode, 1, source, 1);
479 done:
480 	mutex_unlock(&idev->mc_lock);
481 	in6_dev_put(idev);
482 	if (leavegroup)
483 		err = ipv6_sock_mc_drop(sk, pgsr->gsr_interface, group);
484 	return err;
485 }
486 
487 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf,
488 		    struct sockaddr_storage *list)
489 {
490 	struct ipv6_pinfo *inet6 = inet6_sk(sk);
491 	struct ip6_sf_socklist *newpsl, *psl;
492 	struct net *net = sock_net(sk);
493 	const struct in6_addr *group;
494 	struct ipv6_mc_socklist *pmc;
495 	struct inet6_dev *idev;
496 	int leavegroup = 0;
497 	int i, err;
498 
499 	group = &((struct sockaddr_in6 *)&gsf->gf_group)->sin6_addr;
500 
501 	if (!ipv6_addr_is_multicast(group))
502 		return -EINVAL;
503 	if (gsf->gf_fmode != MCAST_INCLUDE &&
504 	    gsf->gf_fmode != MCAST_EXCLUDE)
505 		return -EINVAL;
506 
507 	idev = ip6_mc_find_idev(net, group, gsf->gf_interface);
508 	if (!idev)
509 		return -ENODEV;
510 
511 	mutex_lock(&idev->mc_lock);
512 
513 	if (idev->dead) {
514 		err = -ENODEV;
515 		goto done;
516 	}
517 
518 	err = 0;
519 
520 	if (gsf->gf_fmode == MCAST_INCLUDE && gsf->gf_numsrc == 0) {
521 		leavegroup = 1;
522 		goto done;
523 	}
524 
525 	for_each_pmc_socklock(inet6, sk, pmc) {
526 		if (pmc->ifindex != gsf->gf_interface)
527 			continue;
528 		if (ipv6_addr_equal(&pmc->addr, group))
529 			break;
530 	}
531 	if (!pmc) {		/* must have a prior join */
532 		err = -EINVAL;
533 		goto done;
534 	}
535 	if (gsf->gf_numsrc) {
536 		newpsl = sock_kmalloc(sk, struct_size(newpsl, sl_addr,
537 						      gsf->gf_numsrc),
538 				      GFP_KERNEL);
539 		if (!newpsl) {
540 			err = -ENOBUFS;
541 			goto done;
542 		}
543 		newpsl->sl_max = newpsl->sl_count = gsf->gf_numsrc;
544 		for (i = 0; i < newpsl->sl_count; ++i, ++list) {
545 			struct sockaddr_in6 *psin6;
546 
547 			psin6 = (struct sockaddr_in6 *)list;
548 			newpsl->sl_addr[i] = psin6->sin6_addr;
549 		}
550 
551 		err = ip6_mc_add_src(idev, group, gsf->gf_fmode,
552 				     newpsl->sl_count, newpsl->sl_addr, 0);
553 		if (err) {
554 			sock_kfree_s(sk, newpsl, struct_size(newpsl, sl_addr,
555 							     newpsl->sl_max));
556 			goto done;
557 		}
558 	} else {
559 		newpsl = NULL;
560 		ip6_mc_add_src(idev, group, gsf->gf_fmode, 0, NULL, 0);
561 	}
562 
563 	psl = sock_dereference(pmc->sflist, sk);
564 	if (psl) {
565 		ip6_mc_del_src(idev, group, pmc->sfmode,
566 			       psl->sl_count, psl->sl_addr, 0);
567 		atomic_sub(struct_size(psl, sl_addr, psl->sl_max),
568 			   &sk->sk_omem_alloc);
569 	} else {
570 		ip6_mc_del_src(idev, group, pmc->sfmode, 0, NULL, 0);
571 	}
572 
573 	rcu_assign_pointer(pmc->sflist, newpsl);
574 	kfree_rcu(psl, rcu);
575 	pmc->sfmode = gsf->gf_fmode;
576 	err = 0;
577 done:
578 	mutex_unlock(&idev->mc_lock);
579 	in6_dev_put(idev);
580 	if (leavegroup)
581 		err = ipv6_sock_mc_drop(sk, gsf->gf_interface, group);
582 	return err;
583 }
584 
585 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
586 		  sockptr_t optval, size_t ss_offset)
587 {
588 	struct ipv6_pinfo *inet6 = inet6_sk(sk);
589 	const struct in6_addr *group;
590 	struct ipv6_mc_socklist *pmc;
591 	struct ip6_sf_socklist *psl;
592 	unsigned int count;
593 	int i, copycount;
594 
595 	group = &((struct sockaddr_in6 *)&gsf->gf_group)->sin6_addr;
596 
597 	if (!ipv6_addr_is_multicast(group))
598 		return -EINVAL;
599 
600 	for_each_pmc_socklock(inet6, sk, pmc) {
601 		if (pmc->ifindex != gsf->gf_interface)
602 			continue;
603 		if (ipv6_addr_equal(group, &pmc->addr))
604 			break;
605 	}
606 	if (!pmc)		/* must have a prior join */
607 		return -EADDRNOTAVAIL;
608 
609 	gsf->gf_fmode = pmc->sfmode;
610 	psl = sock_dereference(pmc->sflist, sk);
611 	count = psl ? psl->sl_count : 0;
612 
613 	copycount = min(count, gsf->gf_numsrc);
614 	gsf->gf_numsrc = count;
615 	for (i = 0; i < copycount; i++) {
616 		struct sockaddr_in6 *psin6;
617 		struct sockaddr_storage ss;
618 
619 		psin6 = (struct sockaddr_in6 *)&ss;
620 		memset(&ss, 0, sizeof(ss));
621 		psin6->sin6_family = AF_INET6;
622 		psin6->sin6_addr = psl->sl_addr[i];
623 		if (copy_to_sockptr_offset(optval, ss_offset, &ss, sizeof(ss)))
624 			return -EFAULT;
625 		ss_offset += sizeof(ss);
626 	}
627 	return 0;
628 }
629 
630 bool inet6_mc_check(const struct sock *sk, const struct in6_addr *mc_addr,
631 		    const struct in6_addr *src_addr)
632 {
633 	const struct ipv6_pinfo *np = inet6_sk(sk);
634 	const struct ipv6_mc_socklist *mc;
635 	const struct ip6_sf_socklist *psl;
636 	bool rv = true;
637 
638 	rcu_read_lock();
639 	for_each_pmc_rcu(np, mc) {
640 		if (ipv6_addr_equal(&mc->addr, mc_addr))
641 			break;
642 	}
643 	if (!mc) {
644 		rcu_read_unlock();
645 		return inet6_test_bit(MC6_ALL, sk);
646 	}
647 	psl = rcu_dereference(mc->sflist);
648 	if (!psl) {
649 		rv = mc->sfmode == MCAST_EXCLUDE;
650 	} else {
651 		int i;
652 
653 		for (i = 0; i < psl->sl_count; i++) {
654 			if (ipv6_addr_equal(&psl->sl_addr[i], src_addr))
655 				break;
656 		}
657 		if (mc->sfmode == MCAST_INCLUDE && i >= psl->sl_count)
658 			rv = false;
659 		if (mc->sfmode == MCAST_EXCLUDE && i < psl->sl_count)
660 			rv = false;
661 	}
662 	rcu_read_unlock();
663 
664 	return rv;
665 }
666 
667 static void igmp6_group_added(struct ifmcaddr6 *mc)
668 {
669 	struct net_device *dev = mc->idev->dev;
670 	char buf[MAX_ADDR_LEN];
671 
672 	mc_assert_locked(mc->idev);
673 
674 	if (IPV6_ADDR_MC_SCOPE(&mc->mca_addr) <
675 	    IPV6_ADDR_SCOPE_LINKLOCAL)
676 		return;
677 
678 	if (!(mc->mca_flags&MAF_LOADED)) {
679 		WRITE_ONCE(mc->mca_flags, mc->mca_flags | MAF_LOADED);
680 		if (ndisc_mc_map(&mc->mca_addr, buf, dev, 0) == 0)
681 			dev_mc_add(dev, buf);
682 	}
683 
684 	if (!(dev->flags & IFF_UP) || (mc->mca_flags & MAF_NOREPORT))
685 		return;
686 
687 	if (mld_in_v1_mode(mc->idev)) {
688 		igmp6_join_group(mc);
689 		return;
690 	}
691 	/* else v2 */
692 
693 	/* Based on RFC3810 6.1, for newly added INCLUDE SSM, we
694 	 * should not send filter-mode change record as the mode
695 	 * should be from IN() to IN(A).
696 	 */
697 	if (mc->mca_sfmode == MCAST_EXCLUDE)
698 		mc->mca_crcount = mc->idev->mc_qrv;
699 
700 	mld_ifc_event(mc->idev);
701 }
702 
703 static void igmp6_group_dropped(struct ifmcaddr6 *mc)
704 {
705 	struct net_device *dev = mc->idev->dev;
706 	char buf[MAX_ADDR_LEN];
707 
708 	mc_assert_locked(mc->idev);
709 
710 	if (IPV6_ADDR_MC_SCOPE(&mc->mca_addr) <
711 	    IPV6_ADDR_SCOPE_LINKLOCAL)
712 		return;
713 
714 	if (mc->mca_flags&MAF_LOADED) {
715 		WRITE_ONCE(mc->mca_flags, mc->mca_flags & ~MAF_LOADED);
716 		if (ndisc_mc_map(&mc->mca_addr, buf, dev, 0) == 0)
717 			dev_mc_del(dev, buf);
718 	}
719 
720 	if (mc->mca_flags & MAF_NOREPORT)
721 		return;
722 
723 	if (!mc->idev->dead)
724 		igmp6_leave_group(mc);
725 
726 	if (cancel_delayed_work(&mc->mca_work))
727 		refcount_dec(&mc->mca_refcnt);
728 }
729 
730 /* deleted ifmcaddr6 manipulation */
731 static void mld_add_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im)
732 {
733 	struct ifmcaddr6 *pmc;
734 
735 	mc_assert_locked(idev);
736 
737 	/* this is an "ifmcaddr6" for convenience; only the fields below
738 	 * are actually used. In particular, the refcnt and users are not
739 	 * used for management of the delete list. Using the same structure
740 	 * for deleted items allows change reports to use common code with
741 	 * non-deleted or query-response MCA's.
742 	 */
743 	pmc = kzalloc_obj(*pmc);
744 	if (!pmc)
745 		return;
746 
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 		rcu_assign_pointer(pmc->mca_tomb,
756 				   mc_dereference(im->mca_tomb, idev));
757 		rcu_assign_pointer(pmc->mca_sources,
758 				   mc_dereference(im->mca_sources, idev));
759 		RCU_INIT_POINTER(im->mca_tomb, NULL);
760 		RCU_INIT_POINTER(im->mca_sources, NULL);
761 
762 		for_each_psf_mclock(pmc, psf)
763 			psf->sf_crcount = pmc->mca_crcount;
764 	}
765 
766 	rcu_assign_pointer(pmc->next, idev->mc_tomb);
767 	rcu_assign_pointer(idev->mc_tomb, pmc);
768 }
769 
770 static void mld_del_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im)
771 {
772 	struct ip6_sf_list *psf, *sources, *tomb;
773 	struct in6_addr *pmca = &im->mca_addr;
774 	struct ifmcaddr6 *pmc, *pmc_prev;
775 
776 	mc_assert_locked(idev);
777 
778 	pmc_prev = NULL;
779 	for_each_mc_tomb(idev, pmc) {
780 		if (ipv6_addr_equal(&pmc->mca_addr, pmca))
781 			break;
782 		pmc_prev = pmc;
783 	}
784 	if (!pmc)
785 		return;
786 	if (pmc_prev)
787 		rcu_assign_pointer(pmc_prev->next, pmc->next);
788 	else
789 		rcu_assign_pointer(idev->mc_tomb, pmc->next);
790 
791 	im->idev = pmc->idev;
792 	if (im->mca_sfmode == MCAST_INCLUDE) {
793 		tomb = rcu_replace_pointer(im->mca_tomb,
794 					   mc_dereference(pmc->mca_tomb, pmc->idev),
795 					   lockdep_is_held(&im->idev->mc_lock));
796 		rcu_assign_pointer(pmc->mca_tomb, tomb);
797 
798 		sources = rcu_replace_pointer(im->mca_sources,
799 					      mc_dereference(pmc->mca_sources, pmc->idev),
800 					      lockdep_is_held(&im->idev->mc_lock));
801 		rcu_assign_pointer(pmc->mca_sources, sources);
802 		for_each_psf_mclock(im, psf)
803 			psf->sf_crcount = idev->mc_qrv;
804 	} else {
805 		im->mca_crcount = idev->mc_qrv;
806 	}
807 	ip6_mc_clear_src(pmc);
808 	in6_dev_put(pmc->idev);
809 	kfree_rcu(pmc, rcu);
810 }
811 
812 static void mld_clear_delrec(struct inet6_dev *idev)
813 {
814 	struct ifmcaddr6 *pmc, *nextpmc;
815 
816 	mc_assert_locked(idev);
817 
818 	pmc = mc_dereference(idev->mc_tomb, idev);
819 	RCU_INIT_POINTER(idev->mc_tomb, NULL);
820 
821 	for (; pmc; pmc = nextpmc) {
822 		nextpmc = mc_dereference(pmc->next, idev);
823 		ip6_mc_clear_src(pmc);
824 		in6_dev_put(pmc->idev);
825 		kfree_rcu(pmc, rcu);
826 	}
827 
828 	/* clear dead sources, too */
829 	for_each_mc_mclock(idev, pmc) {
830 		struct ip6_sf_list *psf, *psf_next;
831 
832 		psf = mc_dereference(pmc->mca_tomb, idev);
833 		RCU_INIT_POINTER(pmc->mca_tomb, NULL);
834 		for (; psf; psf = psf_next) {
835 			psf_next = mc_dereference(psf->sf_next, idev);
836 			kfree_rcu(psf, rcu);
837 		}
838 	}
839 }
840 
841 static void mld_clear_query(struct inet6_dev *idev)
842 {
843 	spin_lock_bh(&idev->mc_query_lock);
844 	__skb_queue_purge(&idev->mc_query_queue);
845 	spin_unlock_bh(&idev->mc_query_lock);
846 }
847 
848 static void mld_clear_report(struct inet6_dev *idev)
849 {
850 	spin_lock_bh(&idev->mc_report_lock);
851 	__skb_queue_purge(&idev->mc_report_queue);
852 	spin_unlock_bh(&idev->mc_report_lock);
853 }
854 
855 static void ma_put(struct ifmcaddr6 *mc)
856 {
857 	if (refcount_dec_and_test(&mc->mca_refcnt)) {
858 		in6_dev_put(mc->idev);
859 		kfree_rcu(mc, rcu);
860 	}
861 }
862 
863 static struct ifmcaddr6 *mca_alloc(struct inet6_dev *idev,
864 				   const struct in6_addr *addr,
865 				   unsigned int mode)
866 {
867 	struct ifmcaddr6 *mc;
868 
869 	mc_assert_locked(idev);
870 
871 	mc = kzalloc_obj(*mc);
872 	if (!mc)
873 		return NULL;
874 
875 	INIT_DELAYED_WORK(&mc->mca_work, mld_mca_work);
876 
877 	mc->mca_addr = *addr;
878 	mc->idev = idev; /* reference taken by caller */
879 	WRITE_ONCE(mc->mca_users, 1);
880 	/* mca_stamp should be updated upon changes */
881 	mc->mca_cstamp = mc->mca_tstamp = jiffies;
882 	refcount_set(&mc->mca_refcnt, 1);
883 
884 	mc->mca_sfmode = mode;
885 	mc->mca_sfcount[mode] = 1;
886 
887 	if (ipv6_addr_is_ll_all_nodes(&mc->mca_addr) ||
888 	    IPV6_ADDR_MC_SCOPE(&mc->mca_addr) < IPV6_ADDR_SCOPE_LINKLOCAL)
889 		WRITE_ONCE(mc->mca_flags, mc->mca_flags | MAF_NOREPORT);
890 
891 	return mc;
892 }
893 
894 static void inet6_ifmcaddr_notify(struct net_device *dev,
895 				  const struct ifmcaddr6 *ifmca, int event)
896 {
897 	struct inet6_fill_args fillargs = {
898 		.portid = 0,
899 		.seq = 0,
900 		.event = event,
901 		.flags = 0,
902 		.netnsid = -1,
903 		.force_rt_scope_universe = true,
904 	};
905 	struct net *net = dev_net(dev);
906 	struct sk_buff *skb;
907 	int err = -ENOMEM;
908 
909 	skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct ifaddrmsg)) +
910 			nla_total_size(sizeof(struct in6_addr)) +
911 			nla_total_size(sizeof(struct ifa_cacheinfo)),
912 			GFP_KERNEL);
913 	if (!skb)
914 		goto error;
915 
916 	err = inet6_fill_ifmcaddr(skb, ifmca, &fillargs);
917 	if (err < 0) {
918 		WARN_ON_ONCE(err == -EMSGSIZE);
919 		nlmsg_free(skb);
920 		goto error;
921 	}
922 
923 	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_MCADDR, NULL, GFP_KERNEL);
924 	return;
925 error:
926 	rtnl_set_sk_err(net, RTNLGRP_IPV6_MCADDR, err);
927 }
928 
929 /*
930  *	device multicast group inc (add if not found)
931  */
932 static int __ipv6_dev_mc_inc(struct net_device *dev,
933 			     const struct in6_addr *addr, unsigned int mode)
934 {
935 	struct inet6_dev *idev;
936 	struct ifmcaddr6 *mc;
937 
938 	/* we need to take a reference on idev */
939 	idev = in6_dev_get(dev);
940 	if (!idev)
941 		return -EINVAL;
942 
943 	mutex_lock(&idev->mc_lock);
944 
945 	if (READ_ONCE(idev->dead)) {
946 		mutex_unlock(&idev->mc_lock);
947 		in6_dev_put(idev);
948 		return -ENODEV;
949 	}
950 
951 	for_each_mc_mclock(idev, mc) {
952 		if (ipv6_addr_equal(&mc->mca_addr, addr)) {
953 			WRITE_ONCE(mc->mca_users, mc->mca_users + 1);
954 			ip6_mc_add_src(idev, &mc->mca_addr, mode, 0, NULL, 0);
955 			mutex_unlock(&idev->mc_lock);
956 			in6_dev_put(idev);
957 			return 0;
958 		}
959 	}
960 
961 	mc = mca_alloc(idev, addr, mode);
962 	if (!mc) {
963 		mutex_unlock(&idev->mc_lock);
964 		in6_dev_put(idev);
965 		return -ENOMEM;
966 	}
967 
968 	rcu_assign_pointer(mc->next, idev->mc_list);
969 	rcu_assign_pointer(idev->mc_list, mc);
970 
971 	mld_del_delrec(idev, mc);
972 	igmp6_group_added(mc);
973 	inet6_ifmcaddr_notify(dev, mc, RTM_NEWMULTICAST);
974 	mutex_unlock(&idev->mc_lock);
975 
976 	return 0;
977 }
978 
979 int ipv6_dev_mc_inc(struct net_device *dev, const struct in6_addr *addr)
980 {
981 	return __ipv6_dev_mc_inc(dev, addr, MCAST_EXCLUDE);
982 }
983 EXPORT_SYMBOL(ipv6_dev_mc_inc);
984 
985 /*
986  * device multicast group del
987  */
988 int __ipv6_dev_mc_dec(struct inet6_dev *idev, const struct in6_addr *addr)
989 {
990 	struct ifmcaddr6 *ma, __rcu **map;
991 
992 	mutex_lock(&idev->mc_lock);
993 
994 	for (map = &idev->mc_list;
995 	     (ma = mc_dereference(*map, idev));
996 	     map = &ma->next) {
997 		if (ipv6_addr_equal(&ma->mca_addr, addr)) {
998 			int new_users = ma->mca_users - 1;
999 
1000 			WRITE_ONCE(ma->mca_users, new_users);
1001 			if (new_users == 0) {
1002 				*map = ma->next;
1003 
1004 				igmp6_group_dropped(ma);
1005 				inet6_ifmcaddr_notify(idev->dev, ma,
1006 						      RTM_DELMULTICAST);
1007 				ip6_mc_clear_src(ma);
1008 				mutex_unlock(&idev->mc_lock);
1009 
1010 				ma_put(ma);
1011 				return 0;
1012 			}
1013 			mutex_unlock(&idev->mc_lock);
1014 			return 0;
1015 		}
1016 	}
1017 
1018 	mutex_unlock(&idev->mc_lock);
1019 	return -ENOENT;
1020 }
1021 
1022 int ipv6_dev_mc_dec(struct net_device *dev, const struct in6_addr *addr)
1023 {
1024 	struct inet6_dev *idev;
1025 	int err;
1026 
1027 	idev = in6_dev_get(dev);
1028 	if (!idev)
1029 		return -ENODEV;
1030 
1031 	err = __ipv6_dev_mc_dec(idev, addr);
1032 	in6_dev_put(idev);
1033 
1034 	return err;
1035 }
1036 EXPORT_SYMBOL(ipv6_dev_mc_dec);
1037 
1038 /*
1039  *	check if the interface/address pair is valid
1040  */
1041 bool ipv6_chk_mcast_addr(struct net_device *dev, const struct in6_addr *group,
1042 			 const struct in6_addr *src_addr)
1043 {
1044 	struct inet6_dev *idev;
1045 	struct ifmcaddr6 *mc;
1046 	bool rv = false;
1047 
1048 	rcu_read_lock();
1049 	idev = __in6_dev_get(dev);
1050 	if (!idev)
1051 		goto unlock;
1052 	for_each_mc_rcu(idev, mc) {
1053 		if (ipv6_addr_equal(&mc->mca_addr, group))
1054 			break;
1055 	}
1056 	if (!mc)
1057 		goto unlock;
1058 	if (src_addr && !ipv6_addr_any(src_addr)) {
1059 		struct ip6_sf_list *psf;
1060 
1061 		for_each_psf_rcu(mc, psf) {
1062 			if (ipv6_addr_equal(&psf->sf_addr, src_addr))
1063 				break;
1064 		}
1065 		if (psf)
1066 			rv = READ_ONCE(psf->sf_count[MCAST_INCLUDE]) ||
1067 				READ_ONCE(psf->sf_count[MCAST_EXCLUDE]) !=
1068 				READ_ONCE(mc->mca_sfcount[MCAST_EXCLUDE]);
1069 		else
1070 			rv = READ_ONCE(mc->mca_sfcount[MCAST_EXCLUDE]) != 0;
1071 	} else {
1072 		rv = true; /* don't filter unspecified source */
1073 	}
1074 unlock:
1075 	rcu_read_unlock();
1076 	return rv;
1077 }
1078 
1079 static void mld_gq_start_work(struct inet6_dev *idev)
1080 {
1081 	unsigned long tv = get_random_u32_below(idev->mc_maxdelay);
1082 
1083 	mc_assert_locked(idev);
1084 
1085 	idev->mc_gq_running = 1;
1086 	if (!mod_delayed_work(mld_wq, &idev->mc_gq_work, tv + 2))
1087 		in6_dev_hold(idev);
1088 }
1089 
1090 static void mld_gq_stop_work(struct inet6_dev *idev)
1091 {
1092 	mc_assert_locked(idev);
1093 
1094 	idev->mc_gq_running = 0;
1095 	if (cancel_delayed_work(&idev->mc_gq_work))
1096 		__in6_dev_put(idev);
1097 }
1098 
1099 static void mld_ifc_start_work(struct inet6_dev *idev, unsigned long delay)
1100 {
1101 	unsigned long tv = get_random_u32_below(delay);
1102 
1103 	mc_assert_locked(idev);
1104 
1105 	if (!mod_delayed_work(mld_wq, &idev->mc_ifc_work, tv + 2))
1106 		in6_dev_hold(idev);
1107 }
1108 
1109 static void mld_ifc_stop_work(struct inet6_dev *idev)
1110 {
1111 	mc_assert_locked(idev);
1112 
1113 	idev->mc_ifc_count = 0;
1114 	if (cancel_delayed_work(&idev->mc_ifc_work))
1115 		__in6_dev_put(idev);
1116 }
1117 
1118 static void mld_dad_start_work(struct inet6_dev *idev, unsigned long delay)
1119 {
1120 	unsigned long tv = get_random_u32_below(delay);
1121 
1122 	mc_assert_locked(idev);
1123 
1124 	if (!mod_delayed_work(mld_wq, &idev->mc_dad_work, tv + 2))
1125 		in6_dev_hold(idev);
1126 }
1127 
1128 static void mld_dad_stop_work(struct inet6_dev *idev)
1129 {
1130 	if (cancel_delayed_work(&idev->mc_dad_work))
1131 		__in6_dev_put(idev);
1132 }
1133 
1134 static void mld_query_stop_work(struct inet6_dev *idev)
1135 {
1136 	spin_lock_bh(&idev->mc_query_lock);
1137 	if (cancel_delayed_work(&idev->mc_query_work))
1138 		__in6_dev_put(idev);
1139 	spin_unlock_bh(&idev->mc_query_lock);
1140 }
1141 
1142 static void mld_report_stop_work(struct inet6_dev *idev)
1143 {
1144 	if (cancel_delayed_work_sync(&idev->mc_report_work))
1145 		__in6_dev_put(idev);
1146 }
1147 
1148 /* IGMP handling (alias multicast ICMPv6 messages) */
1149 static void igmp6_group_queried(struct ifmcaddr6 *ma, unsigned long resptime)
1150 {
1151 	unsigned long delay = resptime;
1152 
1153 	mc_assert_locked(ma->idev);
1154 
1155 	/* Do not start work for these addresses */
1156 	if (ipv6_addr_is_ll_all_nodes(&ma->mca_addr) ||
1157 	    IPV6_ADDR_MC_SCOPE(&ma->mca_addr) < IPV6_ADDR_SCOPE_LINKLOCAL)
1158 		return;
1159 
1160 	if (cancel_delayed_work(&ma->mca_work)) {
1161 		refcount_dec(&ma->mca_refcnt);
1162 		delay = ma->mca_work.timer.expires - jiffies;
1163 	}
1164 
1165 	if (delay >= resptime)
1166 		delay = get_random_u32_below(resptime);
1167 
1168 	if (!mod_delayed_work(mld_wq, &ma->mca_work, delay))
1169 		refcount_inc(&ma->mca_refcnt);
1170 	WRITE_ONCE(ma->mca_flags, ma->mca_flags | MAF_TIMER_RUNNING);
1171 }
1172 
1173 /* mark EXCLUDE-mode sources */
1174 static bool mld_xmarksources(struct ifmcaddr6 *pmc, int nsrcs,
1175 			     const struct in6_addr *srcs)
1176 {
1177 	struct ip6_sf_list *psf;
1178 	int i, scount;
1179 
1180 	mc_assert_locked(pmc->idev);
1181 
1182 	scount = 0;
1183 	for_each_psf_mclock(pmc, psf) {
1184 		if (scount == nsrcs)
1185 			break;
1186 		for (i = 0; i < nsrcs; i++) {
1187 			/* skip inactive filters */
1188 			if (psf->sf_count[MCAST_INCLUDE] ||
1189 			    pmc->mca_sfcount[MCAST_EXCLUDE] !=
1190 			    psf->sf_count[MCAST_EXCLUDE])
1191 				break;
1192 			if (ipv6_addr_equal(&srcs[i], &psf->sf_addr)) {
1193 				scount++;
1194 				break;
1195 			}
1196 		}
1197 	}
1198 	WRITE_ONCE(pmc->mca_flags, pmc->mca_flags & ~MAF_GSQUERY);
1199 	if (scount == nsrcs)	/* all sources excluded */
1200 		return false;
1201 	return true;
1202 }
1203 
1204 static bool mld_marksources(struct ifmcaddr6 *pmc, int nsrcs,
1205 			    const struct in6_addr *srcs)
1206 {
1207 	struct ip6_sf_list *psf;
1208 	int i, scount;
1209 
1210 	mc_assert_locked(pmc->idev);
1211 
1212 	if (pmc->mca_sfmode == MCAST_EXCLUDE)
1213 		return mld_xmarksources(pmc, nsrcs, srcs);
1214 
1215 	/* mark INCLUDE-mode sources */
1216 
1217 	scount = 0;
1218 	for_each_psf_mclock(pmc, psf) {
1219 		if (scount == nsrcs)
1220 			break;
1221 		for (i = 0; i < nsrcs; i++) {
1222 			if (ipv6_addr_equal(&srcs[i], &psf->sf_addr)) {
1223 				psf->sf_gsresp = 1;
1224 				scount++;
1225 				break;
1226 			}
1227 		}
1228 	}
1229 	if (!scount) {
1230 		WRITE_ONCE(pmc->mca_flags, pmc->mca_flags & ~MAF_GSQUERY);
1231 		return false;
1232 	}
1233 	WRITE_ONCE(pmc->mca_flags, pmc->mca_flags | MAF_GSQUERY);
1234 	return true;
1235 }
1236 
1237 static int mld_force_mld_version(const struct inet6_dev *idev)
1238 {
1239 	const struct net *net = dev_net(idev->dev);
1240 	int all_force;
1241 
1242 	all_force = READ_ONCE(net->ipv6.devconf_all->force_mld_version);
1243 	/* Normally, both are 0 here. If enforcement to a particular is
1244 	 * being used, individual device enforcement will have a lower
1245 	 * precedence over 'all' device (.../conf/all/force_mld_version).
1246 	 */
1247 	return all_force ?: READ_ONCE(idev->cnf.force_mld_version);
1248 }
1249 
1250 static bool mld_in_v2_mode_only(const struct inet6_dev *idev)
1251 {
1252 	return mld_force_mld_version(idev) == 2;
1253 }
1254 
1255 static bool mld_in_v1_mode_only(const struct inet6_dev *idev)
1256 {
1257 	return mld_force_mld_version(idev) == 1;
1258 }
1259 
1260 static bool mld_in_v1_mode(const struct inet6_dev *idev)
1261 {
1262 	if (mld_in_v2_mode_only(idev))
1263 		return false;
1264 	if (mld_in_v1_mode_only(idev))
1265 		return true;
1266 	if (idev->mc_v1_seen && time_before(jiffies, idev->mc_v1_seen))
1267 		return true;
1268 
1269 	return false;
1270 }
1271 
1272 static void mld_set_v1_mode(struct inet6_dev *idev)
1273 {
1274 	/* RFC3810, relevant sections:
1275 	 *  - 9.1. Robustness Variable
1276 	 *  - 9.2. Query Interval
1277 	 *  - 9.3. Query Response Interval
1278 	 *  - 9.12. Older Version Querier Present Timeout
1279 	 */
1280 	unsigned long switchback;
1281 
1282 	switchback = (idev->mc_qrv * idev->mc_qi) + idev->mc_qri;
1283 
1284 	idev->mc_v1_seen = jiffies + switchback;
1285 }
1286 
1287 static void mld_update_qrv(struct inet6_dev *idev,
1288 			   const struct mld2_query *mlh2)
1289 {
1290 	/* RFC3810, relevant sections:
1291 	 *  - 5.1.8. QRV (Querier's Robustness Variable)
1292 	 *  - 9.1. Robustness Variable
1293 	 */
1294 
1295 	/* The value of the Robustness Variable MUST NOT be zero,
1296 	 * and SHOULD NOT be one. Catch this here if we ever run
1297 	 * into such a case in future.
1298 	 */
1299 	const int min_qrv = min(MLD_QRV_DEFAULT, sysctl_mld_qrv);
1300 	WARN_ON(idev->mc_qrv == 0);
1301 
1302 	if (mlh2->mld2q_qrv > 0)
1303 		idev->mc_qrv = mlh2->mld2q_qrv;
1304 
1305 	if (unlikely(idev->mc_qrv < min_qrv)) {
1306 		net_warn_ratelimited("IPv6: MLD: clamping QRV from %u to %u!\n",
1307 				     idev->mc_qrv, min_qrv);
1308 		idev->mc_qrv = min_qrv;
1309 	}
1310 }
1311 
1312 static void mld_update_qi(struct inet6_dev *idev,
1313 			  const struct mld2_query *mlh2)
1314 {
1315 	/* RFC3810, relevant sections:
1316 	 *  - 5.1.9. QQIC (Querier's Query Interval Code)
1317 	 *  - 9.2. Query Interval
1318 	 *  - 9.12. Older Version Querier Present Timeout
1319 	 *    (the [Query Interval] in the last Query received)
1320 	 */
1321 	idev->mc_qi = mldv2_qqi(mlh2) * HZ;
1322 }
1323 
1324 static void mld_update_qri(struct inet6_dev *idev,
1325 			   const struct mld2_query *mlh2)
1326 {
1327 	/* RFC3810, relevant sections:
1328 	 *  - 5.1.3. Maximum Response Code
1329 	 *  - 9.3. Query Response Interval
1330 	 */
1331 	idev->mc_qri = msecs_to_jiffies(mldv2_mrd(mlh2));
1332 }
1333 
1334 static int mld_process_v1(struct inet6_dev *idev, struct mld_msg *mld,
1335 			  unsigned long *max_delay, bool v1_query)
1336 {
1337 	unsigned long mldv1_md;
1338 
1339 	/* Ignore v1 queries */
1340 	if (mld_in_v2_mode_only(idev))
1341 		return -EINVAL;
1342 
1343 	mldv1_md = ntohs(mld->mld_maxdelay);
1344 
1345 	/* When in MLDv1 fallback and a MLDv2 router start-up being
1346 	 * unaware of current MLDv1 operation, the MRC == MRD mapping
1347 	 * only works when the exponential algorithm is not being
1348 	 * used (as MLDv1 is unaware of such things).
1349 	 *
1350 	 * According to the RFC author, the MLDv2 implementations
1351 	 * he's aware of all use a MRC < 32768 on start up queries.
1352 	 *
1353 	 * Thus, should we *ever* encounter something else larger
1354 	 * than that, just assume the maximum possible within our
1355 	 * reach.
1356 	 */
1357 	if (!v1_query)
1358 		mldv1_md = min(mldv1_md, MLDV1_MRD_MAX_COMPAT);
1359 
1360 	*max_delay = max(msecs_to_jiffies(mldv1_md), 1UL);
1361 
1362 	/* MLDv1 router present: we need to go into v1 mode *only*
1363 	 * when an MLDv1 query is received as per section 9.12. of
1364 	 * RFC3810! And we know from RFC2710 section 3.7 that MLDv1
1365 	 * queries MUST be of exactly 24 octets.
1366 	 */
1367 	if (v1_query)
1368 		mld_set_v1_mode(idev);
1369 
1370 	/* cancel MLDv2 report work */
1371 	mld_gq_stop_work(idev);
1372 	/* cancel the interface change work */
1373 	mld_ifc_stop_work(idev);
1374 	/* clear deleted report items */
1375 	mld_clear_delrec(idev);
1376 
1377 	return 0;
1378 }
1379 
1380 static void mld_process_v2(struct inet6_dev *idev, struct mld2_query *mld,
1381 			   unsigned long *max_delay)
1382 {
1383 	*max_delay = max(msecs_to_jiffies(mldv2_mrd(mld)), 1UL);
1384 
1385 	mld_update_qrv(idev, mld);
1386 	mld_update_qi(idev, mld);
1387 	mld_update_qri(idev, mld);
1388 
1389 	idev->mc_maxdelay = *max_delay;
1390 
1391 	return;
1392 }
1393 
1394 /* called with rcu_read_lock() */
1395 void igmp6_event_query(struct sk_buff *skb)
1396 {
1397 	struct inet6_dev *idev = __in6_dev_get(skb->dev);
1398 
1399 	if (!idev || idev->dead)
1400 		goto out;
1401 
1402 	spin_lock_bh(&idev->mc_query_lock);
1403 	if (skb_queue_len(&idev->mc_query_queue) < MLD_MAX_SKBS) {
1404 		__skb_queue_tail(&idev->mc_query_queue, skb);
1405 		if (!mod_delayed_work(mld_wq, &idev->mc_query_work, 0))
1406 			in6_dev_hold(idev);
1407 		skb = NULL;
1408 	}
1409 	spin_unlock_bh(&idev->mc_query_lock);
1410 out:
1411 	kfree_skb(skb);
1412 }
1413 
1414 static void __mld_query_work(struct sk_buff *skb)
1415 {
1416 	struct mld2_query *mlh2 = NULL;
1417 	unsigned long max_delay;
1418 	struct inet6_dev *idev;
1419 	struct in6_addr group;
1420 	struct ifmcaddr6 *ma;
1421 	struct mld_msg *mld;
1422 	int group_type;
1423 	int mark = 0;
1424 	int len, err;
1425 
1426 	if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
1427 		goto kfree_skb;
1428 
1429 	/* compute payload length excluding extension headers */
1430 	len = ntohs(ipv6_hdr(skb)->payload_len) + sizeof(struct ipv6hdr);
1431 	len -= skb_network_header_len(skb);
1432 
1433 	/* RFC3810 6.2
1434 	 * Upon reception of an MLD message that contains a Query, the node
1435 	 * checks if the source address of the message is a valid link-local
1436 	 * address, if the Hop Limit is set to 1, and if the Router Alert
1437 	 * option is present in the Hop-By-Hop Options header of the IPv6
1438 	 * packet.  If any of these checks fails, the packet is dropped.
1439 	 */
1440 	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL) ||
1441 	    ipv6_hdr(skb)->hop_limit != 1 ||
1442 	    !(IP6CB(skb)->flags & IP6SKB_ROUTERALERT) ||
1443 	    IP6CB(skb)->ra != htons(IPV6_OPT_ROUTERALERT_MLD))
1444 		goto kfree_skb;
1445 
1446 	idev = in6_dev_get(skb->dev);
1447 	if (!idev)
1448 		goto kfree_skb;
1449 
1450 	mld = (struct mld_msg *)icmp6_hdr(skb);
1451 	group = mld->mld_mca;
1452 	group_type = ipv6_addr_type(&group);
1453 
1454 	if (group_type != IPV6_ADDR_ANY &&
1455 	    !(group_type&IPV6_ADDR_MULTICAST))
1456 		goto out;
1457 
1458 	if (len < MLD_V1_QUERY_LEN) {
1459 		goto out;
1460 	} else if (len == MLD_V1_QUERY_LEN || mld_in_v1_mode(idev)) {
1461 		err = mld_process_v1(idev, mld, &max_delay,
1462 				     len == MLD_V1_QUERY_LEN);
1463 		if (err < 0)
1464 			goto out;
1465 	} else if (len >= MLD_V2_QUERY_LEN_MIN) {
1466 		int srcs_offset = sizeof(struct mld2_query) -
1467 				  sizeof(struct icmp6hdr);
1468 
1469 		if (!pskb_may_pull(skb, srcs_offset))
1470 			goto out;
1471 
1472 		mlh2 = (struct mld2_query *)skb_transport_header(skb);
1473 
1474 		mld_process_v2(idev, mlh2, &max_delay);
1475 
1476 		if (group_type == IPV6_ADDR_ANY) { /* general query */
1477 			if (mlh2->mld2q_nsrcs)
1478 				goto out; /* no sources allowed */
1479 
1480 			mld_gq_start_work(idev);
1481 			goto out;
1482 		}
1483 		/* mark sources to include, if group & source-specific */
1484 		if (mlh2->mld2q_nsrcs != 0) {
1485 			if (!pskb_may_pull(skb, srcs_offset +
1486 			    ntohs(mlh2->mld2q_nsrcs) * sizeof(struct in6_addr)))
1487 				goto out;
1488 
1489 			mlh2 = (struct mld2_query *)skb_transport_header(skb);
1490 			mark = 1;
1491 		}
1492 	} else {
1493 		goto out;
1494 	}
1495 
1496 	if (group_type == IPV6_ADDR_ANY) {
1497 		for_each_mc_mclock(idev, ma) {
1498 			igmp6_group_queried(ma, max_delay);
1499 		}
1500 	} else {
1501 		for_each_mc_mclock(idev, ma) {
1502 			unsigned int flags;
1503 
1504 			if (!ipv6_addr_equal(&group, &ma->mca_addr))
1505 				continue;
1506 			flags = ma->mca_flags;
1507 
1508 			if (flags & MAF_TIMER_RUNNING) {
1509 				/* gsquery <- gsquery && mark */
1510 				if (!mark)
1511 					WRITE_ONCE(ma->mca_flags,
1512 						   flags & ~MAF_GSQUERY);
1513 			} else {
1514 				/* gsquery <- mark */
1515 				if (mark)
1516 					WRITE_ONCE(ma->mca_flags,
1517 						   flags | MAF_GSQUERY);
1518 				else
1519 					WRITE_ONCE(ma->mca_flags,
1520 						   flags & ~MAF_GSQUERY);
1521 			}
1522 			if (!(ma->mca_flags & MAF_GSQUERY) ||
1523 			    mld_marksources(ma, ntohs(mlh2->mld2q_nsrcs), mlh2->mld2q_srcs))
1524 				igmp6_group_queried(ma, max_delay);
1525 			break;
1526 		}
1527 	}
1528 
1529 out:
1530 	in6_dev_put(idev);
1531 kfree_skb:
1532 	consume_skb(skb);
1533 }
1534 
1535 static void mld_query_work(struct work_struct *work)
1536 {
1537 	struct inet6_dev *idev = container_of(to_delayed_work(work),
1538 					      struct inet6_dev,
1539 					      mc_query_work);
1540 	struct sk_buff_head q;
1541 	struct sk_buff *skb;
1542 	bool rework = false;
1543 	int cnt = 0;
1544 
1545 	skb_queue_head_init(&q);
1546 
1547 	spin_lock_bh(&idev->mc_query_lock);
1548 	while ((skb = __skb_dequeue(&idev->mc_query_queue))) {
1549 		__skb_queue_tail(&q, skb);
1550 
1551 		if (++cnt >= MLD_MAX_QUEUE) {
1552 			rework = true;
1553 			break;
1554 		}
1555 	}
1556 	spin_unlock_bh(&idev->mc_query_lock);
1557 
1558 	mutex_lock(&idev->mc_lock);
1559 	while ((skb = __skb_dequeue(&q)))
1560 		__mld_query_work(skb);
1561 	mutex_unlock(&idev->mc_lock);
1562 
1563 	if (rework && queue_delayed_work(mld_wq, &idev->mc_query_work, 0))
1564 		return;
1565 
1566 	in6_dev_put(idev);
1567 }
1568 
1569 /* called with rcu_read_lock() */
1570 void igmp6_event_report(struct sk_buff *skb)
1571 {
1572 	struct inet6_dev *idev = __in6_dev_get(skb->dev);
1573 
1574 	if (!idev || idev->dead)
1575 		goto out;
1576 
1577 	spin_lock_bh(&idev->mc_report_lock);
1578 	if (skb_queue_len(&idev->mc_report_queue) < MLD_MAX_SKBS) {
1579 		__skb_queue_tail(&idev->mc_report_queue, skb);
1580 		if (!mod_delayed_work(mld_wq, &idev->mc_report_work, 0))
1581 			in6_dev_hold(idev);
1582 		skb = NULL;
1583 	}
1584 	spin_unlock_bh(&idev->mc_report_lock);
1585 out:
1586 	kfree_skb(skb);
1587 }
1588 
1589 static void __mld_report_work(struct sk_buff *skb)
1590 {
1591 	struct inet6_dev *idev;
1592 	struct ifmcaddr6 *ma;
1593 	struct mld_msg *mld;
1594 	int addr_type;
1595 
1596 	/* Our own report looped back. Ignore it. */
1597 	if (skb->pkt_type == PACKET_LOOPBACK)
1598 		goto kfree_skb;
1599 
1600 	/* send our report if the MC router may not have heard this report */
1601 	if (skb->pkt_type != PACKET_MULTICAST &&
1602 	    skb->pkt_type != PACKET_BROADCAST)
1603 		goto kfree_skb;
1604 
1605 	if (!pskb_may_pull(skb, sizeof(*mld) - sizeof(struct icmp6hdr)))
1606 		goto kfree_skb;
1607 
1608 	mld = (struct mld_msg *)icmp6_hdr(skb);
1609 
1610 	/* Drop reports with not link local source */
1611 	addr_type = ipv6_addr_type(&ipv6_hdr(skb)->saddr);
1612 	if (addr_type != IPV6_ADDR_ANY &&
1613 	    !(addr_type&IPV6_ADDR_LINKLOCAL))
1614 		goto kfree_skb;
1615 
1616 	idev = in6_dev_get(skb->dev);
1617 	if (!idev)
1618 		goto kfree_skb;
1619 
1620 	/*
1621 	 *	Cancel the work for this group
1622 	 */
1623 
1624 	for_each_mc_mclock(idev, ma) {
1625 		if (ipv6_addr_equal(&ma->mca_addr, &mld->mld_mca)) {
1626 			if (cancel_delayed_work(&ma->mca_work))
1627 				refcount_dec(&ma->mca_refcnt);
1628 			WRITE_ONCE(ma->mca_flags,
1629 				   ma->mca_flags & ~(MAF_LAST_REPORTER |
1630 						     MAF_TIMER_RUNNING));
1631 			break;
1632 		}
1633 	}
1634 
1635 	in6_dev_put(idev);
1636 kfree_skb:
1637 	consume_skb(skb);
1638 }
1639 
1640 static void mld_report_work(struct work_struct *work)
1641 {
1642 	struct inet6_dev *idev = container_of(to_delayed_work(work),
1643 					      struct inet6_dev,
1644 					      mc_report_work);
1645 	struct sk_buff_head q;
1646 	struct sk_buff *skb;
1647 	bool rework = false;
1648 	int cnt = 0;
1649 
1650 	skb_queue_head_init(&q);
1651 	spin_lock_bh(&idev->mc_report_lock);
1652 	while ((skb = __skb_dequeue(&idev->mc_report_queue))) {
1653 		__skb_queue_tail(&q, skb);
1654 
1655 		if (++cnt >= MLD_MAX_QUEUE) {
1656 			rework = true;
1657 			break;
1658 		}
1659 	}
1660 	spin_unlock_bh(&idev->mc_report_lock);
1661 
1662 	mutex_lock(&idev->mc_lock);
1663 	while ((skb = __skb_dequeue(&q)))
1664 		__mld_report_work(skb);
1665 	mutex_unlock(&idev->mc_lock);
1666 
1667 	if (rework && queue_delayed_work(mld_wq, &idev->mc_report_work, 0))
1668 		return;
1669 
1670 	in6_dev_put(idev);
1671 }
1672 
1673 static bool is_in(struct ifmcaddr6 *pmc, struct ip6_sf_list *psf, int type,
1674 		  int gdeleted, int sdeleted)
1675 {
1676 	switch (type) {
1677 	case MLD2_MODE_IS_INCLUDE:
1678 	case MLD2_MODE_IS_EXCLUDE:
1679 		if (gdeleted || sdeleted)
1680 			return false;
1681 		if (!((pmc->mca_flags & MAF_GSQUERY) && !psf->sf_gsresp)) {
1682 			if (pmc->mca_sfmode == MCAST_INCLUDE)
1683 				return true;
1684 			/* don't include if this source is excluded
1685 			 * in all filters
1686 			 */
1687 			if (psf->sf_count[MCAST_INCLUDE])
1688 				return type == MLD2_MODE_IS_INCLUDE;
1689 			return pmc->mca_sfcount[MCAST_EXCLUDE] ==
1690 				psf->sf_count[MCAST_EXCLUDE];
1691 		}
1692 		return false;
1693 	case MLD2_CHANGE_TO_INCLUDE:
1694 		if (gdeleted || sdeleted)
1695 			return false;
1696 		return psf->sf_count[MCAST_INCLUDE] != 0;
1697 	case MLD2_CHANGE_TO_EXCLUDE:
1698 		if (gdeleted || sdeleted)
1699 			return false;
1700 		if (pmc->mca_sfcount[MCAST_EXCLUDE] == 0 ||
1701 		    psf->sf_count[MCAST_INCLUDE])
1702 			return false;
1703 		return pmc->mca_sfcount[MCAST_EXCLUDE] ==
1704 			psf->sf_count[MCAST_EXCLUDE];
1705 	case MLD2_ALLOW_NEW_SOURCES:
1706 		if (gdeleted || !psf->sf_crcount)
1707 			return false;
1708 		return (pmc->mca_sfmode == MCAST_INCLUDE) ^ sdeleted;
1709 	case MLD2_BLOCK_OLD_SOURCES:
1710 		if (pmc->mca_sfmode == MCAST_INCLUDE)
1711 			return gdeleted || (psf->sf_crcount && sdeleted);
1712 		return psf->sf_crcount && !gdeleted && !sdeleted;
1713 	}
1714 	return false;
1715 }
1716 
1717 static int
1718 mld_scount(struct ifmcaddr6 *pmc, int type, int gdeleted, int sdeleted)
1719 {
1720 	struct ip6_sf_list *psf;
1721 	int scount = 0;
1722 
1723 	for_each_psf_mclock(pmc, psf) {
1724 		if (!is_in(pmc, psf, type, gdeleted, sdeleted))
1725 			continue;
1726 		scount++;
1727 	}
1728 	return scount;
1729 }
1730 
1731 static void ip6_mc_hdr(const struct sock *sk, struct sk_buff *skb,
1732 		       struct net_device *dev, const struct in6_addr *saddr,
1733 		       const struct in6_addr *daddr, int proto, int len)
1734 {
1735 	struct ipv6hdr *hdr;
1736 
1737 	skb->protocol = htons(ETH_P_IPV6);
1738 	skb->dev = dev;
1739 
1740 	skb_reset_network_header(skb);
1741 	skb_put(skb, sizeof(struct ipv6hdr));
1742 	hdr = ipv6_hdr(skb);
1743 
1744 	ip6_flow_hdr(hdr, 0, 0);
1745 
1746 	hdr->payload_len = htons(len);
1747 	hdr->nexthdr = proto;
1748 	hdr->hop_limit = READ_ONCE(inet6_sk(sk)->hop_limit);
1749 
1750 	hdr->saddr = *saddr;
1751 	hdr->daddr = *daddr;
1752 }
1753 
1754 static struct sk_buff *mld_newpack(struct inet6_dev *idev, unsigned int mtu)
1755 {
1756 	u8 ra[8] = { IPPROTO_ICMPV6, 0, IPV6_TLV_ROUTERALERT,
1757 		     2, 0, 0, IPV6_TLV_PADN, 0 };
1758 	struct net_device *dev = idev->dev;
1759 	int hlen = LL_RESERVED_SPACE(dev);
1760 	int tlen = dev->needed_tailroom;
1761 	const struct in6_addr *saddr;
1762 	struct in6_addr addr_buf;
1763 	struct mld2_report *pmr;
1764 	struct sk_buff *skb;
1765 	unsigned int size;
1766 	struct sock *sk;
1767 	struct net *net;
1768 
1769 	/* we assume size > sizeof(ra) here
1770 	 * Also try to not allocate high-order pages for big MTU
1771 	 */
1772 	size = min_t(int, mtu, PAGE_SIZE / 2) + hlen + tlen;
1773 	skb = alloc_skb(size, GFP_KERNEL);
1774 	if (!skb)
1775 		return NULL;
1776 
1777 	skb->priority = TC_PRIO_CONTROL;
1778 	skb_reserve(skb, hlen);
1779 	skb_tailroom_reserve(skb, mtu, tlen);
1780 
1781 	rcu_read_lock();
1782 
1783 	net = dev_net_rcu(dev);
1784 	sk = net->ipv6.igmp_sk;
1785 	skb_set_owner_w(skb, sk);
1786 
1787 	if (ipv6_get_lladdr(dev, &addr_buf, IFA_F_TENTATIVE)) {
1788 		/* <draft-ietf-magma-mld-source-05.txt>:
1789 		 * use unspecified address as the source address
1790 		 * when a valid link-local address is not available.
1791 		 */
1792 		saddr = &in6addr_any;
1793 	} else
1794 		saddr = &addr_buf;
1795 
1796 	ip6_mc_hdr(sk, skb, dev, saddr, &mld2_all_mcr, NEXTHDR_HOP, 0);
1797 
1798 	rcu_read_unlock();
1799 
1800 	skb_put_data(skb, ra, sizeof(ra));
1801 
1802 	skb_set_transport_header(skb, skb_tail_pointer(skb) - skb->data);
1803 	skb_put(skb, sizeof(*pmr));
1804 	pmr = (struct mld2_report *)skb_transport_header(skb);
1805 	pmr->mld2r_type = ICMPV6_MLD2_REPORT;
1806 	pmr->mld2r_resv1 = 0;
1807 	pmr->mld2r_cksum = 0;
1808 	pmr->mld2r_resv2 = 0;
1809 	pmr->mld2r_ngrec = 0;
1810 	return skb;
1811 }
1812 
1813 static void mld_sendpack(struct sk_buff *skb)
1814 {
1815 	struct ipv6hdr *pip6 = ipv6_hdr(skb);
1816 	struct mld2_report *pmr =
1817 			      (struct mld2_report *)skb_transport_header(skb);
1818 	int payload_len, mldlen;
1819 	struct inet6_dev *idev;
1820 	struct net *net = dev_net(skb->dev);
1821 	int err;
1822 	struct flowi6 fl6;
1823 	struct dst_entry *dst;
1824 
1825 	rcu_read_lock();
1826 	idev = __in6_dev_get(skb->dev);
1827 	IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS);
1828 
1829 	payload_len = (skb_tail_pointer(skb) - skb_network_header(skb)) -
1830 		sizeof(*pip6);
1831 	mldlen = skb_tail_pointer(skb) - skb_transport_header(skb);
1832 	pip6->payload_len = htons(payload_len);
1833 
1834 	pmr->mld2r_cksum = csum_ipv6_magic(&pip6->saddr, &pip6->daddr, mldlen,
1835 					   IPPROTO_ICMPV6,
1836 					   csum_partial(skb_transport_header(skb),
1837 							mldlen, 0));
1838 
1839 	icmpv6_flow_init(net->ipv6.igmp_sk, &fl6, ICMPV6_MLD2_REPORT,
1840 			 &ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
1841 			 skb->dev->ifindex);
1842 	dst = icmp6_dst_alloc(skb->dev, &fl6);
1843 
1844 	err = 0;
1845 	if (IS_ERR(dst)) {
1846 		err = PTR_ERR(dst);
1847 		dst = NULL;
1848 	}
1849 	skb_dst_set(skb, dst);
1850 	if (err)
1851 		goto err_out;
1852 
1853 	err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
1854 		      net, net->ipv6.igmp_sk, skb, NULL, skb->dev,
1855 		      dst_output);
1856 out:
1857 	if (!err) {
1858 		ICMP6MSGOUT_INC_STATS(net, idev, ICMPV6_MLD2_REPORT);
1859 		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
1860 	} else {
1861 		IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
1862 	}
1863 
1864 	rcu_read_unlock();
1865 	return;
1866 
1867 err_out:
1868 	kfree_skb(skb);
1869 	goto out;
1870 }
1871 
1872 static int grec_size(struct ifmcaddr6 *pmc, int type, int gdel, int sdel)
1873 {
1874 	return sizeof(struct mld2_grec) + 16 * mld_scount(pmc,type,gdel,sdel);
1875 }
1876 
1877 static struct sk_buff *add_grhead(struct sk_buff *skb, struct ifmcaddr6 *pmc,
1878 	int type, struct mld2_grec **ppgr, unsigned int mtu)
1879 {
1880 	struct mld2_report *pmr;
1881 	struct mld2_grec *pgr;
1882 
1883 	if (!skb) {
1884 		skb = mld_newpack(pmc->idev, mtu);
1885 		if (!skb)
1886 			return NULL;
1887 	}
1888 	pgr = skb_put(skb, sizeof(struct mld2_grec));
1889 	pgr->grec_type = type;
1890 	pgr->grec_auxwords = 0;
1891 	pgr->grec_nsrcs = 0;
1892 	pgr->grec_mca = pmc->mca_addr;	/* structure copy */
1893 	pmr = (struct mld2_report *)skb_transport_header(skb);
1894 	pmr->mld2r_ngrec = htons(ntohs(pmr->mld2r_ngrec)+1);
1895 	*ppgr = pgr;
1896 	return skb;
1897 }
1898 
1899 #define AVAILABLE(skb)	((skb) ? skb_availroom(skb) : 0)
1900 
1901 static struct sk_buff *add_grec(struct sk_buff *skb, struct ifmcaddr6 *pmc,
1902 				int type, int gdeleted, int sdeleted,
1903 				int crsend)
1904 {
1905 	struct ip6_sf_list *psf, *psf_prev, *psf_next;
1906 	int scount, stotal, first, isquery, truncate;
1907 	struct ip6_sf_list __rcu **psf_list;
1908 	struct inet6_dev *idev = pmc->idev;
1909 	struct net_device *dev = idev->dev;
1910 	struct mld2_grec *pgr = NULL;
1911 	struct mld2_report *pmr;
1912 	unsigned int mtu;
1913 
1914 	mc_assert_locked(idev);
1915 
1916 	if (pmc->mca_flags & MAF_NOREPORT)
1917 		return skb;
1918 
1919 	mtu = READ_ONCE(dev->mtu);
1920 	if (mtu < IPV6_MIN_MTU)
1921 		return skb;
1922 
1923 	isquery = type == MLD2_MODE_IS_INCLUDE ||
1924 		  type == MLD2_MODE_IS_EXCLUDE;
1925 	truncate = type == MLD2_MODE_IS_EXCLUDE ||
1926 		    type == MLD2_CHANGE_TO_EXCLUDE;
1927 
1928 	stotal = scount = 0;
1929 
1930 	psf_list = sdeleted ? &pmc->mca_tomb : &pmc->mca_sources;
1931 
1932 	if (!rcu_access_pointer(*psf_list))
1933 		goto empty_source;
1934 
1935 	pmr = skb ? (struct mld2_report *)skb_transport_header(skb) : NULL;
1936 
1937 	/* EX and TO_EX get a fresh packet, if needed */
1938 	if (truncate) {
1939 		if (pmr && pmr->mld2r_ngrec &&
1940 		    AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) {
1941 			if (skb)
1942 				mld_sendpack(skb);
1943 			skb = mld_newpack(idev, mtu);
1944 		}
1945 	}
1946 	first = 1;
1947 	psf_prev = NULL;
1948 	for (psf = mc_dereference(*psf_list, idev);
1949 	     psf;
1950 	     psf = psf_next) {
1951 		struct in6_addr *psrc;
1952 
1953 		psf_next = mc_dereference(psf->sf_next, idev);
1954 
1955 		if (!is_in(pmc, psf, type, gdeleted, sdeleted) && !crsend) {
1956 			psf_prev = psf;
1957 			continue;
1958 		}
1959 
1960 		/* Based on RFC3810 6.1. Should not send source-list change
1961 		 * records when there is a filter mode change.
1962 		 */
1963 		if (((gdeleted && pmc->mca_sfmode == MCAST_EXCLUDE) ||
1964 		     (!gdeleted && pmc->mca_crcount)) &&
1965 		    (type == MLD2_ALLOW_NEW_SOURCES ||
1966 		     type == MLD2_BLOCK_OLD_SOURCES) && psf->sf_crcount)
1967 			goto decrease_sf_crcount;
1968 
1969 		/* clear marks on query responses */
1970 		if (isquery)
1971 			psf->sf_gsresp = 0;
1972 
1973 		if (AVAILABLE(skb) < sizeof(*psrc) +
1974 		    first*sizeof(struct mld2_grec)) {
1975 			if (truncate && !first)
1976 				break;	 /* truncate these */
1977 			if (pgr)
1978 				pgr->grec_nsrcs = htons(scount);
1979 			if (skb)
1980 				mld_sendpack(skb);
1981 			skb = mld_newpack(idev, mtu);
1982 			first = 1;
1983 			scount = 0;
1984 		}
1985 		if (first) {
1986 			skb = add_grhead(skb, pmc, type, &pgr, mtu);
1987 			first = 0;
1988 		}
1989 		if (!skb)
1990 			return NULL;
1991 		psrc = skb_put(skb, sizeof(*psrc));
1992 		*psrc = psf->sf_addr;
1993 		scount++; stotal++;
1994 		if ((type == MLD2_ALLOW_NEW_SOURCES ||
1995 		     type == MLD2_BLOCK_OLD_SOURCES) && psf->sf_crcount) {
1996 decrease_sf_crcount:
1997 			psf->sf_crcount--;
1998 			if ((sdeleted || gdeleted) && psf->sf_crcount == 0) {
1999 				if (psf_prev)
2000 					rcu_assign_pointer(psf_prev->sf_next,
2001 							   mc_dereference(psf->sf_next, idev));
2002 				else
2003 					rcu_assign_pointer(*psf_list,
2004 							   mc_dereference(psf->sf_next, idev));
2005 				kfree_rcu(psf, rcu);
2006 				continue;
2007 			}
2008 		}
2009 		psf_prev = psf;
2010 	}
2011 
2012 empty_source:
2013 	if (!stotal) {
2014 		if (type == MLD2_ALLOW_NEW_SOURCES ||
2015 		    type == MLD2_BLOCK_OLD_SOURCES)
2016 			return skb;
2017 		if (pmc->mca_crcount || isquery || crsend) {
2018 			/* make sure we have room for group header */
2019 			if (skb && AVAILABLE(skb) < sizeof(struct mld2_grec)) {
2020 				mld_sendpack(skb);
2021 				skb = NULL; /* add_grhead will get a new one */
2022 			}
2023 			skb = add_grhead(skb, pmc, type, &pgr, mtu);
2024 		}
2025 	}
2026 	if (pgr)
2027 		pgr->grec_nsrcs = htons(scount);
2028 
2029 	if (isquery) {
2030 		/* clear query state */
2031 		WRITE_ONCE(pmc->mca_flags, pmc->mca_flags & ~MAF_GSQUERY);
2032 	}
2033 	return skb;
2034 }
2035 
2036 static void mld_send_report(struct inet6_dev *idev, struct ifmcaddr6 *pmc)
2037 {
2038 	struct sk_buff *skb = NULL;
2039 	int type;
2040 
2041 	mc_assert_locked(idev);
2042 
2043 	if (!pmc) {
2044 		for_each_mc_mclock(idev, pmc) {
2045 			if (pmc->mca_flags & MAF_NOREPORT)
2046 				continue;
2047 			if (pmc->mca_sfcount[MCAST_EXCLUDE])
2048 				type = MLD2_MODE_IS_EXCLUDE;
2049 			else
2050 				type = MLD2_MODE_IS_INCLUDE;
2051 			skb = add_grec(skb, pmc, type, 0, 0, 0);
2052 		}
2053 	} else {
2054 		if (pmc->mca_sfcount[MCAST_EXCLUDE])
2055 			type = MLD2_MODE_IS_EXCLUDE;
2056 		else
2057 			type = MLD2_MODE_IS_INCLUDE;
2058 		skb = add_grec(skb, pmc, type, 0, 0, 0);
2059 	}
2060 	if (skb)
2061 		mld_sendpack(skb);
2062 }
2063 
2064 /* remove zero-count source records from a source filter list */
2065 static void mld_clear_zeros(struct ip6_sf_list __rcu **ppsf, struct inet6_dev *idev)
2066 {
2067 	struct ip6_sf_list *psf_prev, *psf_next, *psf;
2068 
2069 	psf_prev = NULL;
2070 	for (psf = mc_dereference(*ppsf, idev);
2071 	     psf;
2072 	     psf = psf_next) {
2073 		psf_next = mc_dereference(psf->sf_next, idev);
2074 		if (psf->sf_crcount == 0) {
2075 			if (psf_prev)
2076 				rcu_assign_pointer(psf_prev->sf_next,
2077 						   mc_dereference(psf->sf_next, idev));
2078 			else
2079 				rcu_assign_pointer(*ppsf,
2080 						   mc_dereference(psf->sf_next, idev));
2081 			kfree_rcu(psf, rcu);
2082 		} else {
2083 			psf_prev = psf;
2084 		}
2085 	}
2086 }
2087 
2088 static void mld_send_cr(struct inet6_dev *idev)
2089 {
2090 	struct ifmcaddr6 *pmc, *pmc_prev, *pmc_next;
2091 	struct sk_buff *skb = NULL;
2092 	int type, dtype;
2093 
2094 	/* deleted MCA's */
2095 	pmc_prev = NULL;
2096 	for (pmc = mc_dereference(idev->mc_tomb, idev);
2097 	     pmc;
2098 	     pmc = pmc_next) {
2099 		pmc_next = mc_dereference(pmc->next, idev);
2100 		if (pmc->mca_sfmode == MCAST_INCLUDE) {
2101 			type = MLD2_BLOCK_OLD_SOURCES;
2102 			dtype = MLD2_BLOCK_OLD_SOURCES;
2103 			skb = add_grec(skb, pmc, type, 1, 0, 0);
2104 			skb = add_grec(skb, pmc, dtype, 1, 1, 0);
2105 		}
2106 		if (pmc->mca_crcount) {
2107 			if (pmc->mca_sfmode == MCAST_EXCLUDE) {
2108 				type = MLD2_CHANGE_TO_INCLUDE;
2109 				skb = add_grec(skb, pmc, type, 1, 0, 0);
2110 			}
2111 			pmc->mca_crcount--;
2112 			if (pmc->mca_crcount == 0) {
2113 				mld_clear_zeros(&pmc->mca_tomb, idev);
2114 				mld_clear_zeros(&pmc->mca_sources, idev);
2115 			}
2116 		}
2117 		if (pmc->mca_crcount == 0 &&
2118 		    !rcu_access_pointer(pmc->mca_tomb) &&
2119 		    !rcu_access_pointer(pmc->mca_sources)) {
2120 			if (pmc_prev)
2121 				rcu_assign_pointer(pmc_prev->next, pmc_next);
2122 			else
2123 				rcu_assign_pointer(idev->mc_tomb, pmc_next);
2124 			in6_dev_put(pmc->idev);
2125 			kfree_rcu(pmc, rcu);
2126 		} else
2127 			pmc_prev = pmc;
2128 	}
2129 
2130 	/* change recs */
2131 	for_each_mc_mclock(idev, pmc) {
2132 		if (pmc->mca_sfcount[MCAST_EXCLUDE]) {
2133 			type = MLD2_BLOCK_OLD_SOURCES;
2134 			dtype = MLD2_ALLOW_NEW_SOURCES;
2135 		} else {
2136 			type = MLD2_ALLOW_NEW_SOURCES;
2137 			dtype = MLD2_BLOCK_OLD_SOURCES;
2138 		}
2139 		skb = add_grec(skb, pmc, type, 0, 0, 0);
2140 		skb = add_grec(skb, pmc, dtype, 0, 1, 0);	/* deleted sources */
2141 
2142 		/* filter mode changes */
2143 		if (pmc->mca_crcount) {
2144 			if (pmc->mca_sfmode == MCAST_EXCLUDE)
2145 				type = MLD2_CHANGE_TO_EXCLUDE;
2146 			else
2147 				type = MLD2_CHANGE_TO_INCLUDE;
2148 			skb = add_grec(skb, pmc, type, 0, 0, 0);
2149 			pmc->mca_crcount--;
2150 		}
2151 	}
2152 	if (!skb)
2153 		return;
2154 	(void) mld_sendpack(skb);
2155 }
2156 
2157 static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
2158 {
2159 	const struct in6_addr *snd_addr, *saddr;
2160 	int err, len, payload_len, full_len;
2161 	struct in6_addr addr_buf;
2162 	struct inet6_dev *idev;
2163 	struct sk_buff *skb;
2164 	struct mld_msg *hdr;
2165 	int hlen = LL_RESERVED_SPACE(dev);
2166 	int tlen = dev->needed_tailroom;
2167 	u8 ra[8] = { IPPROTO_ICMPV6, 0,
2168 		     IPV6_TLV_ROUTERALERT, 2, 0, 0,
2169 		     IPV6_TLV_PADN, 0 };
2170 	struct dst_entry *dst;
2171 	struct flowi6 fl6;
2172 	struct net *net;
2173 	struct sock *sk;
2174 
2175 	if (type == ICMPV6_MGM_REDUCTION)
2176 		snd_addr = &in6addr_linklocal_allrouters;
2177 	else
2178 		snd_addr = addr;
2179 
2180 	len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
2181 	payload_len = len + sizeof(ra);
2182 	full_len = sizeof(struct ipv6hdr) + payload_len;
2183 
2184 	skb = alloc_skb(hlen + tlen + full_len, GFP_KERNEL);
2185 
2186 	rcu_read_lock();
2187 
2188 	net = dev_net_rcu(dev);
2189 	idev = __in6_dev_get(dev);
2190 	IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS);
2191 	if (!skb) {
2192 		IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
2193 		rcu_read_unlock();
2194 		return;
2195 	}
2196 	sk = net->ipv6.igmp_sk;
2197 	skb_set_owner_w(skb, sk);
2198 
2199 	skb->priority = TC_PRIO_CONTROL;
2200 	skb_reserve(skb, hlen);
2201 
2202 	if (ipv6_get_lladdr(dev, &addr_buf, IFA_F_TENTATIVE)) {
2203 		/* <draft-ietf-magma-mld-source-05.txt>:
2204 		 * use unspecified address as the source address
2205 		 * when a valid link-local address is not available.
2206 		 */
2207 		saddr = &in6addr_any;
2208 	} else
2209 		saddr = &addr_buf;
2210 
2211 	ip6_mc_hdr(sk, skb, dev, saddr, snd_addr, NEXTHDR_HOP, payload_len);
2212 
2213 	skb_put_data(skb, ra, sizeof(ra));
2214 
2215 	hdr = skb_put_zero(skb, sizeof(struct mld_msg));
2216 	hdr->mld_type = type;
2217 	hdr->mld_mca = *addr;
2218 
2219 	hdr->mld_cksum = csum_ipv6_magic(saddr, snd_addr, len,
2220 					 IPPROTO_ICMPV6,
2221 					 csum_partial(hdr, len, 0));
2222 
2223 	icmpv6_flow_init(sk, &fl6, type,
2224 			 &ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
2225 			 skb->dev->ifindex);
2226 	dst = icmp6_dst_alloc(skb->dev, &fl6);
2227 	if (IS_ERR(dst)) {
2228 		err = PTR_ERR(dst);
2229 		goto err_out;
2230 	}
2231 
2232 	skb_dst_set(skb, dst);
2233 	err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
2234 		      net, sk, skb, NULL, skb->dev,
2235 		      dst_output);
2236 out:
2237 	if (!err) {
2238 		ICMP6MSGOUT_INC_STATS(net, idev, type);
2239 		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
2240 	} else
2241 		IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
2242 
2243 	rcu_read_unlock();
2244 	return;
2245 
2246 err_out:
2247 	kfree_skb(skb);
2248 	goto out;
2249 }
2250 
2251 static void mld_send_initial_cr(struct inet6_dev *idev)
2252 {
2253 	struct ifmcaddr6 *pmc;
2254 	struct sk_buff *skb;
2255 	int type;
2256 
2257 	mc_assert_locked(idev);
2258 
2259 	if (mld_in_v1_mode(idev))
2260 		return;
2261 
2262 	skb = NULL;
2263 	for_each_mc_mclock(idev, pmc) {
2264 		if (pmc->mca_sfcount[MCAST_EXCLUDE])
2265 			type = MLD2_CHANGE_TO_EXCLUDE;
2266 		else
2267 			type = MLD2_ALLOW_NEW_SOURCES;
2268 		skb = add_grec(skb, pmc, type, 0, 0, 1);
2269 	}
2270 	if (skb)
2271 		mld_sendpack(skb);
2272 }
2273 
2274 void ipv6_mc_dad_complete(struct inet6_dev *idev)
2275 {
2276 	mutex_lock(&idev->mc_lock);
2277 	idev->mc_dad_count = idev->mc_qrv;
2278 	if (idev->mc_dad_count) {
2279 		mld_send_initial_cr(idev);
2280 		idev->mc_dad_count--;
2281 		if (idev->mc_dad_count)
2282 			mld_dad_start_work(idev,
2283 					   unsolicited_report_interval(idev));
2284 	}
2285 	mutex_unlock(&idev->mc_lock);
2286 }
2287 
2288 static void mld_dad_work(struct work_struct *work)
2289 {
2290 	struct inet6_dev *idev = container_of(to_delayed_work(work),
2291 					      struct inet6_dev,
2292 					      mc_dad_work);
2293 	mutex_lock(&idev->mc_lock);
2294 	mld_send_initial_cr(idev);
2295 	if (idev->mc_dad_count) {
2296 		idev->mc_dad_count--;
2297 		if (idev->mc_dad_count)
2298 			mld_dad_start_work(idev,
2299 					   unsolicited_report_interval(idev));
2300 	}
2301 	mutex_unlock(&idev->mc_lock);
2302 	in6_dev_put(idev);
2303 }
2304 
2305 static int ip6_mc_del1_src(struct ifmcaddr6 *pmc, int sfmode,
2306 			   const struct in6_addr *psfsrc)
2307 {
2308 	struct ip6_sf_list *psf, *psf_prev;
2309 	int rv = 0;
2310 
2311 	mc_assert_locked(pmc->idev);
2312 
2313 	psf_prev = NULL;
2314 	for_each_psf_mclock(pmc, psf) {
2315 		if (ipv6_addr_equal(&psf->sf_addr, psfsrc))
2316 			break;
2317 		psf_prev = psf;
2318 	}
2319 	if (!psf || psf->sf_count[sfmode] == 0) {
2320 		/* source filter not found, or count wrong =>  bug */
2321 		return -ESRCH;
2322 	}
2323 	WRITE_ONCE(psf->sf_count[sfmode], psf->sf_count[sfmode] - 1);
2324 	if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) {
2325 		struct inet6_dev *idev = pmc->idev;
2326 
2327 		/* no more filters for this source */
2328 		if (psf_prev)
2329 			rcu_assign_pointer(psf_prev->sf_next,
2330 					   mc_dereference(psf->sf_next, idev));
2331 		else
2332 			rcu_assign_pointer(pmc->mca_sources,
2333 					   mc_dereference(psf->sf_next, idev));
2334 
2335 		if (psf->sf_oldin && !(pmc->mca_flags & MAF_NOREPORT) &&
2336 		    !mld_in_v1_mode(idev)) {
2337 			psf->sf_crcount = idev->mc_qrv;
2338 			rcu_assign_pointer(psf->sf_next,
2339 					   mc_dereference(pmc->mca_tomb, idev));
2340 			rcu_assign_pointer(pmc->mca_tomb, psf);
2341 			rv = 1;
2342 		} else {
2343 			kfree_rcu(psf, rcu);
2344 		}
2345 	}
2346 	return rv;
2347 }
2348 
2349 static int ip6_mc_del_src(struct inet6_dev *idev, const struct in6_addr *pmca,
2350 			  int sfmode, int sfcount, const struct in6_addr *psfsrc,
2351 			  int delta)
2352 {
2353 	struct ifmcaddr6 *pmc;
2354 	int	changerec = 0;
2355 	int	i, err;
2356 
2357 	if (!idev)
2358 		return -ENODEV;
2359 
2360 	mc_assert_locked(idev);
2361 
2362 	for_each_mc_mclock(idev, pmc) {
2363 		if (ipv6_addr_equal(pmca, &pmc->mca_addr))
2364 			break;
2365 	}
2366 	if (!pmc)
2367 		return -ESRCH;
2368 
2369 	sf_markstate(pmc);
2370 	if (!delta) {
2371 		if (!pmc->mca_sfcount[sfmode])
2372 			return -EINVAL;
2373 
2374 		pmc->mca_sfcount[sfmode]--;
2375 	}
2376 	err = 0;
2377 	for (i = 0; i < sfcount; i++) {
2378 		int rv = ip6_mc_del1_src(pmc, sfmode, &psfsrc[i]);
2379 
2380 		changerec |= rv > 0;
2381 		if (!err && rv < 0)
2382 			err = rv;
2383 	}
2384 	if (pmc->mca_sfmode == MCAST_EXCLUDE &&
2385 	    pmc->mca_sfcount[MCAST_EXCLUDE] == 0 &&
2386 	    pmc->mca_sfcount[MCAST_INCLUDE]) {
2387 		struct ip6_sf_list *psf;
2388 
2389 		/* filter mode change */
2390 		pmc->mca_sfmode = MCAST_INCLUDE;
2391 		pmc->mca_crcount = idev->mc_qrv;
2392 		idev->mc_ifc_count = pmc->mca_crcount;
2393 		for_each_psf_mclock(pmc, psf)
2394 			psf->sf_crcount = 0;
2395 		mld_ifc_event(pmc->idev);
2396 	} else if (sf_setstate(pmc) || changerec) {
2397 		mld_ifc_event(pmc->idev);
2398 	}
2399 
2400 	return err;
2401 }
2402 
2403 /* Add multicast single-source filter to the interface list */
2404 static int ip6_mc_add1_src(struct ifmcaddr6 *pmc, int sfmode,
2405 			   const struct in6_addr *psfsrc)
2406 {
2407 	struct ip6_sf_list *psf, *psf_prev;
2408 
2409 	mc_assert_locked(pmc->idev);
2410 
2411 	psf_prev = NULL;
2412 	for_each_psf_mclock(pmc, psf) {
2413 		if (ipv6_addr_equal(&psf->sf_addr, psfsrc))
2414 			break;
2415 		psf_prev = psf;
2416 	}
2417 	if (!psf) {
2418 		psf = kzalloc_obj(*psf);
2419 		if (!psf)
2420 			return -ENOBUFS;
2421 
2422 		psf->sf_addr = *psfsrc;
2423 		if (psf_prev) {
2424 			rcu_assign_pointer(psf_prev->sf_next, psf);
2425 		} else {
2426 			rcu_assign_pointer(pmc->mca_sources, psf);
2427 		}
2428 	}
2429 	WRITE_ONCE(psf->sf_count[sfmode], psf->sf_count[sfmode] + 1);
2430 	return 0;
2431 }
2432 
2433 static void sf_markstate(struct ifmcaddr6 *pmc)
2434 {
2435 	int mca_xcount = pmc->mca_sfcount[MCAST_EXCLUDE];
2436 	struct ip6_sf_list *psf;
2437 
2438 	mc_assert_locked(pmc->idev);
2439 
2440 	for_each_psf_mclock(pmc, psf) {
2441 		if (pmc->mca_sfcount[MCAST_EXCLUDE]) {
2442 			psf->sf_oldin = mca_xcount ==
2443 				psf->sf_count[MCAST_EXCLUDE] &&
2444 				!psf->sf_count[MCAST_INCLUDE];
2445 		} else {
2446 			psf->sf_oldin = psf->sf_count[MCAST_INCLUDE] != 0;
2447 		}
2448 	}
2449 }
2450 
2451 static int sf_setstate(struct ifmcaddr6 *pmc)
2452 {
2453 	int mca_xcount = pmc->mca_sfcount[MCAST_EXCLUDE];
2454 	struct ip6_sf_list *psf, *dpsf;
2455 	int qrv = pmc->idev->mc_qrv;
2456 	int new_in, rv;
2457 
2458 	mc_assert_locked(pmc->idev);
2459 
2460 	rv = 0;
2461 	for_each_psf_mclock(pmc, psf) {
2462 		if (pmc->mca_sfcount[MCAST_EXCLUDE]) {
2463 			new_in = mca_xcount == psf->sf_count[MCAST_EXCLUDE] &&
2464 				!psf->sf_count[MCAST_INCLUDE];
2465 		} else
2466 			new_in = psf->sf_count[MCAST_INCLUDE] != 0;
2467 		if (new_in) {
2468 			if (!psf->sf_oldin) {
2469 				struct ip6_sf_list *prev = NULL;
2470 
2471 				for_each_psf_tomb(pmc, dpsf) {
2472 					if (ipv6_addr_equal(&dpsf->sf_addr,
2473 					    &psf->sf_addr))
2474 						break;
2475 					prev = dpsf;
2476 				}
2477 				if (dpsf) {
2478 					if (prev)
2479 						rcu_assign_pointer(prev->sf_next,
2480 								   mc_dereference(dpsf->sf_next,
2481 										  pmc->idev));
2482 					else
2483 						rcu_assign_pointer(pmc->mca_tomb,
2484 								   mc_dereference(dpsf->sf_next,
2485 										  pmc->idev));
2486 					kfree_rcu(dpsf, rcu);
2487 				}
2488 				psf->sf_crcount = qrv;
2489 				rv++;
2490 			}
2491 		} else if (psf->sf_oldin) {
2492 			psf->sf_crcount = 0;
2493 			/*
2494 			 * add or update "delete" records if an active filter
2495 			 * is now inactive
2496 			 */
2497 
2498 			for_each_psf_tomb(pmc, dpsf)
2499 				if (ipv6_addr_equal(&dpsf->sf_addr,
2500 				    &psf->sf_addr))
2501 					break;
2502 			if (!dpsf) {
2503 				dpsf = kmalloc_obj(*dpsf);
2504 				if (!dpsf)
2505 					continue;
2506 				*dpsf = *psf;
2507 				rcu_assign_pointer(dpsf->sf_next,
2508 						   mc_dereference(pmc->mca_tomb, pmc->idev));
2509 				rcu_assign_pointer(pmc->mca_tomb, dpsf);
2510 			}
2511 			dpsf->sf_crcount = qrv;
2512 			rv++;
2513 		}
2514 	}
2515 	return rv;
2516 }
2517 
2518 /* Add multicast source filter list to the interface list */
2519 static int ip6_mc_add_src(struct inet6_dev *idev, const struct in6_addr *pmca,
2520 			  int sfmode, int sfcount, const struct in6_addr *psfsrc,
2521 			  int delta)
2522 {
2523 	struct ifmcaddr6 *pmc;
2524 	int	isexclude;
2525 	int	i, err;
2526 
2527 	if (!idev)
2528 		return -ENODEV;
2529 
2530 	mc_assert_locked(idev);
2531 
2532 	for_each_mc_mclock(idev, pmc) {
2533 		if (ipv6_addr_equal(pmca, &pmc->mca_addr))
2534 			break;
2535 	}
2536 	if (!pmc)
2537 		return -ESRCH;
2538 
2539 	sf_markstate(pmc);
2540 	isexclude = pmc->mca_sfmode == MCAST_EXCLUDE;
2541 	if (!delta)
2542 		WRITE_ONCE(pmc->mca_sfcount[sfmode],
2543 			   pmc->mca_sfcount[sfmode] + 1);
2544 	err = 0;
2545 	for (i = 0; i < sfcount; i++) {
2546 		err = ip6_mc_add1_src(pmc, sfmode, &psfsrc[i]);
2547 		if (err)
2548 			break;
2549 	}
2550 	if (err) {
2551 		int j;
2552 
2553 		if (!delta)
2554 			WRITE_ONCE(pmc->mca_sfcount[sfmode],
2555 				   pmc->mca_sfcount[sfmode] - 1);
2556 		for (j = 0; j < i; j++)
2557 			ip6_mc_del1_src(pmc, sfmode, &psfsrc[j]);
2558 	} else if (isexclude != (pmc->mca_sfcount[MCAST_EXCLUDE] != 0)) {
2559 		struct ip6_sf_list *psf;
2560 
2561 		/* filter mode change */
2562 		if (pmc->mca_sfcount[MCAST_EXCLUDE])
2563 			pmc->mca_sfmode = MCAST_EXCLUDE;
2564 		else if (pmc->mca_sfcount[MCAST_INCLUDE])
2565 			pmc->mca_sfmode = MCAST_INCLUDE;
2566 		/* else no filters; keep old mode for reports */
2567 
2568 		pmc->mca_crcount = idev->mc_qrv;
2569 		idev->mc_ifc_count = pmc->mca_crcount;
2570 		for_each_psf_mclock(pmc, psf)
2571 			psf->sf_crcount = 0;
2572 		mld_ifc_event(idev);
2573 	} else if (sf_setstate(pmc)) {
2574 		mld_ifc_event(idev);
2575 	}
2576 	return err;
2577 }
2578 
2579 static void ip6_mc_clear_src(struct ifmcaddr6 *pmc)
2580 {
2581 	struct ip6_sf_list *psf, *nextpsf;
2582 
2583 	mc_assert_locked(pmc->idev);
2584 
2585 	for (psf = mc_dereference(pmc->mca_tomb, pmc->idev);
2586 	     psf;
2587 	     psf = nextpsf) {
2588 		nextpsf = mc_dereference(psf->sf_next, pmc->idev);
2589 		kfree_rcu(psf, rcu);
2590 	}
2591 	RCU_INIT_POINTER(pmc->mca_tomb, NULL);
2592 	for (psf = mc_dereference(pmc->mca_sources, pmc->idev);
2593 	     psf;
2594 	     psf = nextpsf) {
2595 		nextpsf = mc_dereference(psf->sf_next, pmc->idev);
2596 		kfree_rcu(psf, rcu);
2597 	}
2598 	RCU_INIT_POINTER(pmc->mca_sources, NULL);
2599 	pmc->mca_sfmode = MCAST_EXCLUDE;
2600 	pmc->mca_sfcount[MCAST_INCLUDE] = 0;
2601 	/* Paired with the READ_ONCE() from ipv6_chk_mcast_addr() */
2602 	WRITE_ONCE(pmc->mca_sfcount[MCAST_EXCLUDE], 1);
2603 }
2604 
2605 static void igmp6_join_group(struct ifmcaddr6 *ma)
2606 {
2607 	unsigned long delay;
2608 
2609 	mc_assert_locked(ma->idev);
2610 
2611 	if (ma->mca_flags & MAF_NOREPORT)
2612 		return;
2613 
2614 	igmp6_send(&ma->mca_addr, ma->idev->dev, ICMPV6_MGM_REPORT);
2615 
2616 	delay = get_random_u32_below(unsolicited_report_interval(ma->idev));
2617 
2618 	if (cancel_delayed_work(&ma->mca_work)) {
2619 		refcount_dec(&ma->mca_refcnt);
2620 		delay = ma->mca_work.timer.expires - jiffies;
2621 	}
2622 
2623 	if (!mod_delayed_work(mld_wq, &ma->mca_work, delay))
2624 		refcount_inc(&ma->mca_refcnt);
2625 	WRITE_ONCE(ma->mca_flags, ma->mca_flags |
2626 		   MAF_TIMER_RUNNING | MAF_LAST_REPORTER);
2627 }
2628 
2629 static int ip6_mc_leave_src(struct sock *sk, struct ipv6_mc_socklist *iml,
2630 			    struct inet6_dev *idev)
2631 {
2632 	struct ip6_sf_socklist *psl;
2633 	int err;
2634 
2635 	psl = sock_dereference(iml->sflist, sk);
2636 
2637 	if (idev)
2638 		mutex_lock(&idev->mc_lock);
2639 
2640 	if (!psl) {
2641 		/* any-source empty exclude case */
2642 		err = ip6_mc_del_src(idev, &iml->addr, iml->sfmode, 0, NULL, 0);
2643 	} else {
2644 		err = ip6_mc_del_src(idev, &iml->addr, iml->sfmode,
2645 				     psl->sl_count, psl->sl_addr, 0);
2646 		RCU_INIT_POINTER(iml->sflist, NULL);
2647 		atomic_sub(struct_size(psl, sl_addr, psl->sl_max),
2648 			   &sk->sk_omem_alloc);
2649 		kfree_rcu(psl, rcu);
2650 	}
2651 
2652 	if (idev)
2653 		mutex_unlock(&idev->mc_lock);
2654 
2655 	return err;
2656 }
2657 
2658 static void igmp6_leave_group(struct ifmcaddr6 *ma)
2659 {
2660 	mc_assert_locked(ma->idev);
2661 
2662 	if (mld_in_v1_mode(ma->idev)) {
2663 		if (ma->mca_flags & MAF_LAST_REPORTER) {
2664 			igmp6_send(&ma->mca_addr, ma->idev->dev,
2665 				ICMPV6_MGM_REDUCTION);
2666 		}
2667 	} else {
2668 		mld_add_delrec(ma->idev, ma);
2669 		mld_ifc_event(ma->idev);
2670 	}
2671 }
2672 
2673 static void mld_gq_work(struct work_struct *work)
2674 {
2675 	struct inet6_dev *idev = container_of(to_delayed_work(work),
2676 					      struct inet6_dev,
2677 					      mc_gq_work);
2678 
2679 	mutex_lock(&idev->mc_lock);
2680 	mld_send_report(idev, NULL);
2681 	idev->mc_gq_running = 0;
2682 	mutex_unlock(&idev->mc_lock);
2683 
2684 	in6_dev_put(idev);
2685 }
2686 
2687 static void mld_ifc_work(struct work_struct *work)
2688 {
2689 	struct inet6_dev *idev = container_of(to_delayed_work(work),
2690 					      struct inet6_dev,
2691 					      mc_ifc_work);
2692 
2693 	mutex_lock(&idev->mc_lock);
2694 	mld_send_cr(idev);
2695 
2696 	if (idev->mc_ifc_count) {
2697 		idev->mc_ifc_count--;
2698 		if (idev->mc_ifc_count)
2699 			mld_ifc_start_work(idev,
2700 					   unsolicited_report_interval(idev));
2701 	}
2702 	mutex_unlock(&idev->mc_lock);
2703 	in6_dev_put(idev);
2704 }
2705 
2706 static void mld_ifc_event(struct inet6_dev *idev)
2707 {
2708 	mc_assert_locked(idev);
2709 
2710 	if (mld_in_v1_mode(idev))
2711 		return;
2712 
2713 	idev->mc_ifc_count = idev->mc_qrv;
2714 	mld_ifc_start_work(idev, 1);
2715 }
2716 
2717 static void mld_mca_work(struct work_struct *work)
2718 {
2719 	struct ifmcaddr6 *ma = container_of(to_delayed_work(work),
2720 					    struct ifmcaddr6, mca_work);
2721 
2722 	mutex_lock(&ma->idev->mc_lock);
2723 	if (mld_in_v1_mode(ma->idev))
2724 		igmp6_send(&ma->mca_addr, ma->idev->dev, ICMPV6_MGM_REPORT);
2725 	else
2726 		mld_send_report(ma->idev, ma);
2727 	WRITE_ONCE(ma->mca_flags, (ma->mca_flags | MAF_LAST_REPORTER) &
2728 		   ~MAF_TIMER_RUNNING);
2729 	mutex_unlock(&ma->idev->mc_lock);
2730 
2731 	ma_put(ma);
2732 }
2733 
2734 /* Device changing type */
2735 
2736 void ipv6_mc_unmap(struct inet6_dev *idev)
2737 {
2738 	struct ifmcaddr6 *i;
2739 
2740 	/* Install multicast list, except for all-nodes (already installed) */
2741 
2742 	mutex_lock(&idev->mc_lock);
2743 	for_each_mc_mclock(idev, i)
2744 		igmp6_group_dropped(i);
2745 	mutex_unlock(&idev->mc_lock);
2746 }
2747 
2748 void ipv6_mc_remap(struct inet6_dev *idev)
2749 {
2750 	ipv6_mc_up(idev);
2751 }
2752 
2753 /* Device going down */
2754 void ipv6_mc_down(struct inet6_dev *idev)
2755 {
2756 	struct ifmcaddr6 *i;
2757 
2758 	mutex_lock(&idev->mc_lock);
2759 	/* Withdraw multicast list */
2760 	for_each_mc_mclock(idev, i)
2761 		igmp6_group_dropped(i);
2762 	mutex_unlock(&idev->mc_lock);
2763 
2764 	/* Should stop work after group drop. or we will
2765 	 * start work again in mld_ifc_event()
2766 	 */
2767 	mld_query_stop_work(idev);
2768 	mld_report_stop_work(idev);
2769 
2770 	mutex_lock(&idev->mc_lock);
2771 	mld_ifc_stop_work(idev);
2772 	mld_gq_stop_work(idev);
2773 	mutex_unlock(&idev->mc_lock);
2774 
2775 	mld_dad_stop_work(idev);
2776 }
2777 
2778 static void ipv6_mc_reset(struct inet6_dev *idev)
2779 {
2780 	idev->mc_qrv = sysctl_mld_qrv;
2781 	idev->mc_qi = MLD_QI_DEFAULT;
2782 	idev->mc_qri = MLD_QRI_DEFAULT;
2783 	idev->mc_v1_seen = 0;
2784 	idev->mc_maxdelay = unsolicited_report_interval(idev);
2785 }
2786 
2787 /* Device going up */
2788 
2789 void ipv6_mc_up(struct inet6_dev *idev)
2790 {
2791 	struct ifmcaddr6 *i;
2792 
2793 	/* Install multicast list, except for all-nodes (already installed) */
2794 
2795 	ipv6_mc_reset(idev);
2796 	mutex_lock(&idev->mc_lock);
2797 	for_each_mc_mclock(idev, i) {
2798 		mld_del_delrec(idev, i);
2799 		igmp6_group_added(i);
2800 	}
2801 	mutex_unlock(&idev->mc_lock);
2802 }
2803 
2804 /* IPv6 device initialization. */
2805 
2806 void ipv6_mc_init_dev(struct inet6_dev *idev)
2807 {
2808 	idev->mc_gq_running = 0;
2809 	INIT_DELAYED_WORK(&idev->mc_gq_work, mld_gq_work);
2810 	RCU_INIT_POINTER(idev->mc_tomb, NULL);
2811 	idev->mc_ifc_count = 0;
2812 	INIT_DELAYED_WORK(&idev->mc_ifc_work, mld_ifc_work);
2813 	INIT_DELAYED_WORK(&idev->mc_dad_work, mld_dad_work);
2814 	INIT_DELAYED_WORK(&idev->mc_query_work, mld_query_work);
2815 	INIT_DELAYED_WORK(&idev->mc_report_work, mld_report_work);
2816 	skb_queue_head_init(&idev->mc_query_queue);
2817 	skb_queue_head_init(&idev->mc_report_queue);
2818 	spin_lock_init(&idev->mc_query_lock);
2819 	spin_lock_init(&idev->mc_report_lock);
2820 	mutex_init(&idev->mc_lock);
2821 	ipv6_mc_reset(idev);
2822 }
2823 
2824 /*
2825  *	Device is about to be destroyed: clean up.
2826  */
2827 
2828 void ipv6_mc_destroy_dev(struct inet6_dev *idev)
2829 {
2830 	struct ifmcaddr6 *i;
2831 
2832 	/* Deactivate works */
2833 	ipv6_mc_down(idev);
2834 	mutex_lock(&idev->mc_lock);
2835 	mld_clear_delrec(idev);
2836 	mutex_unlock(&idev->mc_lock);
2837 	mld_clear_query(idev);
2838 	mld_clear_report(idev);
2839 
2840 	/* Delete all-nodes address. */
2841 	/* We cannot call ipv6_dev_mc_dec() directly, our caller in
2842 	 * addrconf.c has NULL'd out dev->ip6_ptr so in6_dev_get() will
2843 	 * fail.
2844 	 */
2845 	__ipv6_dev_mc_dec(idev, &in6addr_linklocal_allnodes);
2846 
2847 	if (idev->cnf.forwarding)
2848 		__ipv6_dev_mc_dec(idev, &in6addr_linklocal_allrouters);
2849 
2850 	mutex_lock(&idev->mc_lock);
2851 	while ((i = mc_dereference(idev->mc_list, idev))) {
2852 		rcu_assign_pointer(idev->mc_list, mc_dereference(i->next, idev));
2853 
2854 		ip6_mc_clear_src(i);
2855 		ma_put(i);
2856 	}
2857 	mutex_unlock(&idev->mc_lock);
2858 }
2859 
2860 static void ipv6_mc_rejoin_groups(struct inet6_dev *idev)
2861 {
2862 	struct ifmcaddr6 *pmc;
2863 
2864 	mutex_lock(&idev->mc_lock);
2865 	if (mld_in_v1_mode(idev)) {
2866 		for_each_mc_mclock(idev, pmc)
2867 			igmp6_join_group(pmc);
2868 	} else {
2869 		mld_send_report(idev, NULL);
2870 	}
2871 	mutex_unlock(&idev->mc_lock);
2872 }
2873 
2874 static int ipv6_mc_netdev_event(struct notifier_block *this,
2875 				unsigned long event,
2876 				void *ptr)
2877 {
2878 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
2879 	struct inet6_dev *idev = __in6_dev_get(dev);
2880 
2881 	switch (event) {
2882 	case NETDEV_RESEND_IGMP:
2883 		if (idev)
2884 			ipv6_mc_rejoin_groups(idev);
2885 		break;
2886 	default:
2887 		break;
2888 	}
2889 
2890 	return NOTIFY_DONE;
2891 }
2892 
2893 static struct notifier_block igmp6_netdev_notifier = {
2894 	.notifier_call = ipv6_mc_netdev_event,
2895 };
2896 
2897 #ifdef CONFIG_PROC_FS
2898 struct igmp6_mc_iter_state {
2899 	struct seq_net_private p;
2900 	struct net_device *dev;
2901 	struct inet6_dev *idev;
2902 };
2903 
2904 #define igmp6_mc_seq_private(seq)	((struct igmp6_mc_iter_state *)(seq)->private)
2905 
2906 static inline struct ifmcaddr6 *igmp6_mc_get_first(struct seq_file *seq)
2907 {
2908 	struct ifmcaddr6 *im = NULL;
2909 	struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq);
2910 	struct net *net = seq_file_net(seq);
2911 
2912 	state->idev = NULL;
2913 	for_each_netdev_rcu(net, state->dev) {
2914 		struct inet6_dev *idev;
2915 		idev = __in6_dev_get(state->dev);
2916 		if (!idev)
2917 			continue;
2918 
2919 		im = rcu_dereference(idev->mc_list);
2920 		if (im) {
2921 			state->idev = idev;
2922 			break;
2923 		}
2924 	}
2925 	return im;
2926 }
2927 
2928 static struct ifmcaddr6 *igmp6_mc_get_next(struct seq_file *seq, struct ifmcaddr6 *im)
2929 {
2930 	struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq);
2931 
2932 	im = rcu_dereference(im->next);
2933 	while (!im) {
2934 		state->dev = next_net_device_rcu(state->dev);
2935 		if (!state->dev) {
2936 			state->idev = NULL;
2937 			break;
2938 		}
2939 		state->idev = __in6_dev_get(state->dev);
2940 		if (!state->idev)
2941 			continue;
2942 		im = rcu_dereference(state->idev->mc_list);
2943 	}
2944 	return im;
2945 }
2946 
2947 static struct ifmcaddr6 *igmp6_mc_get_idx(struct seq_file *seq, loff_t pos)
2948 {
2949 	struct ifmcaddr6 *im = igmp6_mc_get_first(seq);
2950 	if (im)
2951 		while (pos && (im = igmp6_mc_get_next(seq, im)) != NULL)
2952 			--pos;
2953 	return pos ? NULL : im;
2954 }
2955 
2956 static void *igmp6_mc_seq_start(struct seq_file *seq, loff_t *pos)
2957 	__acquires(RCU)
2958 {
2959 	rcu_read_lock();
2960 	return igmp6_mc_get_idx(seq, *pos);
2961 }
2962 
2963 static void *igmp6_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2964 {
2965 	struct ifmcaddr6 *im = igmp6_mc_get_next(seq, v);
2966 
2967 	++*pos;
2968 	return im;
2969 }
2970 
2971 static void igmp6_mc_seq_stop(struct seq_file *seq, void *v)
2972 	__releases(RCU)
2973 {
2974 	struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq);
2975 
2976 	if (likely(state->idev))
2977 		state->idev = NULL;
2978 	state->dev = NULL;
2979 	rcu_read_unlock();
2980 }
2981 
2982 static int igmp6_mc_seq_show(struct seq_file *seq, void *v)
2983 {
2984 	struct ifmcaddr6 *im = (struct ifmcaddr6 *)v;
2985 	struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq);
2986 	unsigned int mca_flags = READ_ONCE(im->mca_flags);
2987 	unsigned long expires = READ_ONCE(im->mca_work.timer.expires);
2988 
2989 	seq_printf(seq,
2990 		   "%-4d %-15s %pi6 %5d %08X %ld\n",
2991 		   state->dev->ifindex, state->dev->name,
2992 		   &im->mca_addr,
2993 		   READ_ONCE(im->mca_users), mca_flags,
2994 		   (mca_flags & MAF_TIMER_RUNNING) ?
2995 		   jiffies_to_clock_t(expires - jiffies) : 0);
2996 	return 0;
2997 }
2998 
2999 static const struct seq_operations igmp6_mc_seq_ops = {
3000 	.start	=	igmp6_mc_seq_start,
3001 	.next	=	igmp6_mc_seq_next,
3002 	.stop	=	igmp6_mc_seq_stop,
3003 	.show	=	igmp6_mc_seq_show,
3004 };
3005 
3006 struct igmp6_mcf_iter_state {
3007 	struct seq_net_private p;
3008 	struct net_device *dev;
3009 	struct inet6_dev *idev;
3010 	struct ifmcaddr6 *im;
3011 };
3012 
3013 #define igmp6_mcf_seq_private(seq)	((struct igmp6_mcf_iter_state *)(seq)->private)
3014 
3015 static inline struct ip6_sf_list *igmp6_mcf_get_first(struct seq_file *seq)
3016 {
3017 	struct ip6_sf_list *psf = NULL;
3018 	struct ifmcaddr6 *im = NULL;
3019 	struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);
3020 	struct net *net = seq_file_net(seq);
3021 
3022 	state->idev = NULL;
3023 	state->im = NULL;
3024 	for_each_netdev_rcu(net, state->dev) {
3025 		struct inet6_dev *idev;
3026 		idev = __in6_dev_get(state->dev);
3027 		if (unlikely(idev == NULL))
3028 			continue;
3029 
3030 		im = rcu_dereference(idev->mc_list);
3031 		if (likely(im)) {
3032 			psf = rcu_dereference(im->mca_sources);
3033 			if (likely(psf)) {
3034 				state->im = im;
3035 				state->idev = idev;
3036 				break;
3037 			}
3038 		}
3039 	}
3040 	return psf;
3041 }
3042 
3043 static struct ip6_sf_list *igmp6_mcf_get_next(struct seq_file *seq, struct ip6_sf_list *psf)
3044 {
3045 	struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);
3046 
3047 	psf = rcu_dereference(psf->sf_next);
3048 	while (!psf) {
3049 		state->im = rcu_dereference(state->im->next);
3050 		while (!state->im) {
3051 			state->dev = next_net_device_rcu(state->dev);
3052 			if (!state->dev) {
3053 				state->idev = NULL;
3054 				goto out;
3055 			}
3056 			state->idev = __in6_dev_get(state->dev);
3057 			if (!state->idev)
3058 				continue;
3059 			state->im = rcu_dereference(state->idev->mc_list);
3060 		}
3061 		psf = rcu_dereference(state->im->mca_sources);
3062 	}
3063 out:
3064 	return psf;
3065 }
3066 
3067 static struct ip6_sf_list *igmp6_mcf_get_idx(struct seq_file *seq, loff_t pos)
3068 {
3069 	struct ip6_sf_list *psf = igmp6_mcf_get_first(seq);
3070 	if (psf)
3071 		while (pos && (psf = igmp6_mcf_get_next(seq, psf)) != NULL)
3072 			--pos;
3073 	return pos ? NULL : psf;
3074 }
3075 
3076 static void *igmp6_mcf_seq_start(struct seq_file *seq, loff_t *pos)
3077 	__acquires(RCU)
3078 {
3079 	rcu_read_lock();
3080 	return *pos ? igmp6_mcf_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
3081 }
3082 
3083 static void *igmp6_mcf_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3084 {
3085 	struct ip6_sf_list *psf;
3086 	if (v == SEQ_START_TOKEN)
3087 		psf = igmp6_mcf_get_first(seq);
3088 	else
3089 		psf = igmp6_mcf_get_next(seq, v);
3090 	++*pos;
3091 	return psf;
3092 }
3093 
3094 static void igmp6_mcf_seq_stop(struct seq_file *seq, void *v)
3095 	__releases(RCU)
3096 {
3097 	struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);
3098 
3099 	if (likely(state->im))
3100 		state->im = NULL;
3101 	if (likely(state->idev))
3102 		state->idev = NULL;
3103 
3104 	state->dev = NULL;
3105 	rcu_read_unlock();
3106 }
3107 
3108 static int igmp6_mcf_seq_show(struct seq_file *seq, void *v)
3109 {
3110 	struct ip6_sf_list *psf = (struct ip6_sf_list *)v;
3111 	struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);
3112 
3113 	if (v == SEQ_START_TOKEN) {
3114 		seq_puts(seq, "Idx Device                Multicast Address                   Source Address    INC    EXC\n");
3115 	} else {
3116 		seq_printf(seq,
3117 			   "%3d %6.6s %pi6 %pi6 %6lu %6lu\n",
3118 			   state->dev->ifindex, state->dev->name,
3119 			   &state->im->mca_addr,
3120 			   &psf->sf_addr,
3121 			   READ_ONCE(psf->sf_count[MCAST_INCLUDE]),
3122 			   READ_ONCE(psf->sf_count[MCAST_EXCLUDE]));
3123 	}
3124 	return 0;
3125 }
3126 
3127 static const struct seq_operations igmp6_mcf_seq_ops = {
3128 	.start	=	igmp6_mcf_seq_start,
3129 	.next	=	igmp6_mcf_seq_next,
3130 	.stop	=	igmp6_mcf_seq_stop,
3131 	.show	=	igmp6_mcf_seq_show,
3132 };
3133 
3134 static int __net_init igmp6_proc_init(struct net *net)
3135 {
3136 	int err;
3137 
3138 	err = -ENOMEM;
3139 	if (!proc_create_net("igmp6", 0444, net->proc_net, &igmp6_mc_seq_ops,
3140 			sizeof(struct igmp6_mc_iter_state)))
3141 		goto out;
3142 	if (!proc_create_net("mcfilter6", 0444, net->proc_net,
3143 			&igmp6_mcf_seq_ops,
3144 			sizeof(struct igmp6_mcf_iter_state)))
3145 		goto out_proc_net_igmp6;
3146 
3147 	err = 0;
3148 out:
3149 	return err;
3150 
3151 out_proc_net_igmp6:
3152 	remove_proc_entry("igmp6", net->proc_net);
3153 	goto out;
3154 }
3155 
3156 static void __net_exit igmp6_proc_exit(struct net *net)
3157 {
3158 	remove_proc_entry("mcfilter6", net->proc_net);
3159 	remove_proc_entry("igmp6", net->proc_net);
3160 }
3161 #else
3162 static inline int igmp6_proc_init(struct net *net)
3163 {
3164 	return 0;
3165 }
3166 static inline void igmp6_proc_exit(struct net *net)
3167 {
3168 }
3169 #endif
3170 
3171 static int __net_init igmp6_net_init(struct net *net)
3172 {
3173 	int err;
3174 
3175 	err = inet_ctl_sock_create(&net->ipv6.igmp_sk, PF_INET6,
3176 				   SOCK_RAW, IPPROTO_ICMPV6, net);
3177 	if (err < 0) {
3178 		pr_err("Failed to initialize the IGMP6 control socket (err %d)\n",
3179 		       err);
3180 		goto out;
3181 	}
3182 
3183 	inet6_sk(net->ipv6.igmp_sk)->hop_limit = 1;
3184 	net->ipv6.igmp_sk->sk_allocation = GFP_KERNEL;
3185 
3186 	err = inet_ctl_sock_create(&net->ipv6.mc_autojoin_sk, PF_INET6,
3187 				   SOCK_RAW, IPPROTO_ICMPV6, net);
3188 	if (err < 0) {
3189 		pr_err("Failed to initialize the IGMP6 autojoin socket (err %d)\n",
3190 		       err);
3191 		goto out_sock_create;
3192 	}
3193 
3194 	err = igmp6_proc_init(net);
3195 	if (err)
3196 		goto out_sock_create_autojoin;
3197 
3198 	return 0;
3199 
3200 out_sock_create_autojoin:
3201 	inet_ctl_sock_destroy(net->ipv6.mc_autojoin_sk);
3202 out_sock_create:
3203 	inet_ctl_sock_destroy(net->ipv6.igmp_sk);
3204 out:
3205 	return err;
3206 }
3207 
3208 static void __net_exit igmp6_net_exit(struct net *net)
3209 {
3210 	inet_ctl_sock_destroy(net->ipv6.igmp_sk);
3211 	inet_ctl_sock_destroy(net->ipv6.mc_autojoin_sk);
3212 	igmp6_proc_exit(net);
3213 }
3214 
3215 static struct pernet_operations igmp6_net_ops = {
3216 	.init = igmp6_net_init,
3217 	.exit = igmp6_net_exit,
3218 };
3219 
3220 int __init igmp6_init(void)
3221 {
3222 	int err;
3223 
3224 	err = register_pernet_subsys(&igmp6_net_ops);
3225 	if (err)
3226 		return err;
3227 
3228 	mld_wq = create_workqueue("mld");
3229 	if (!mld_wq) {
3230 		unregister_pernet_subsys(&igmp6_net_ops);
3231 		return -ENOMEM;
3232 	}
3233 
3234 	return err;
3235 }
3236 
3237 int __init igmp6_late_init(void)
3238 {
3239 	return register_netdevice_notifier(&igmp6_netdev_notifier);
3240 }
3241 
3242 void igmp6_cleanup(void)
3243 {
3244 	unregister_pernet_subsys(&igmp6_net_ops);
3245 	destroy_workqueue(mld_wq);
3246 }
3247 
3248 void igmp6_late_cleanup(void)
3249 {
3250 	unregister_netdevice_notifier(&igmp6_netdev_notifier);
3251 }
3252