xref: /openbmc/linux/net/bridge/br_multicast.c (revision 63dc02bd)
1 /*
2  * Bridge multicast support.
3  *
4  * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License as published by the Free
8  * Software Foundation; either version 2 of the License, or (at your option)
9  * any later version.
10  *
11  */
12 
13 #include <linux/err.h>
14 #include <linux/if_ether.h>
15 #include <linux/igmp.h>
16 #include <linux/jhash.h>
17 #include <linux/kernel.h>
18 #include <linux/log2.h>
19 #include <linux/netdevice.h>
20 #include <linux/netfilter_bridge.h>
21 #include <linux/random.h>
22 #include <linux/rculist.h>
23 #include <linux/skbuff.h>
24 #include <linux/slab.h>
25 #include <linux/timer.h>
26 #include <net/ip.h>
27 #if IS_ENABLED(CONFIG_IPV6)
28 #include <net/ipv6.h>
29 #include <net/mld.h>
30 #include <net/addrconf.h>
31 #include <net/ip6_checksum.h>
32 #endif
33 
34 #include "br_private.h"
35 
36 #define mlock_dereference(X, br) \
37 	rcu_dereference_protected(X, lockdep_is_held(&br->multicast_lock))
38 
39 #if IS_ENABLED(CONFIG_IPV6)
40 static inline int ipv6_is_transient_multicast(const struct in6_addr *addr)
41 {
42 	if (ipv6_addr_is_multicast(addr) && IPV6_ADDR_MC_FLAG_TRANSIENT(addr))
43 		return 1;
44 	return 0;
45 }
46 #endif
47 
48 static inline int br_ip_equal(const struct br_ip *a, const struct br_ip *b)
49 {
50 	if (a->proto != b->proto)
51 		return 0;
52 	switch (a->proto) {
53 	case htons(ETH_P_IP):
54 		return a->u.ip4 == b->u.ip4;
55 #if IS_ENABLED(CONFIG_IPV6)
56 	case htons(ETH_P_IPV6):
57 		return ipv6_addr_equal(&a->u.ip6, &b->u.ip6);
58 #endif
59 	}
60 	return 0;
61 }
62 
63 static inline int __br_ip4_hash(struct net_bridge_mdb_htable *mdb, __be32 ip)
64 {
65 	return jhash_1word(mdb->secret, (__force u32)ip) & (mdb->max - 1);
66 }
67 
68 #if IS_ENABLED(CONFIG_IPV6)
69 static inline int __br_ip6_hash(struct net_bridge_mdb_htable *mdb,
70 				const struct in6_addr *ip)
71 {
72 	return jhash2((__force u32 *)ip->s6_addr32, 4, mdb->secret) & (mdb->max - 1);
73 }
74 #endif
75 
76 static inline int br_ip_hash(struct net_bridge_mdb_htable *mdb,
77 			     struct br_ip *ip)
78 {
79 	switch (ip->proto) {
80 	case htons(ETH_P_IP):
81 		return __br_ip4_hash(mdb, ip->u.ip4);
82 #if IS_ENABLED(CONFIG_IPV6)
83 	case htons(ETH_P_IPV6):
84 		return __br_ip6_hash(mdb, &ip->u.ip6);
85 #endif
86 	}
87 	return 0;
88 }
89 
90 static struct net_bridge_mdb_entry *__br_mdb_ip_get(
91 	struct net_bridge_mdb_htable *mdb, struct br_ip *dst, int hash)
92 {
93 	struct net_bridge_mdb_entry *mp;
94 	struct hlist_node *p;
95 
96 	hlist_for_each_entry_rcu(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) {
97 		if (br_ip_equal(&mp->addr, dst))
98 			return mp;
99 	}
100 
101 	return NULL;
102 }
103 
104 static struct net_bridge_mdb_entry *br_mdb_ip_get(
105 	struct net_bridge_mdb_htable *mdb, struct br_ip *dst)
106 {
107 	if (!mdb)
108 		return NULL;
109 
110 	return __br_mdb_ip_get(mdb, dst, br_ip_hash(mdb, dst));
111 }
112 
113 static struct net_bridge_mdb_entry *br_mdb_ip4_get(
114 	struct net_bridge_mdb_htable *mdb, __be32 dst)
115 {
116 	struct br_ip br_dst;
117 
118 	br_dst.u.ip4 = dst;
119 	br_dst.proto = htons(ETH_P_IP);
120 
121 	return br_mdb_ip_get(mdb, &br_dst);
122 }
123 
124 #if IS_ENABLED(CONFIG_IPV6)
125 static struct net_bridge_mdb_entry *br_mdb_ip6_get(
126 	struct net_bridge_mdb_htable *mdb, const struct in6_addr *dst)
127 {
128 	struct br_ip br_dst;
129 
130 	br_dst.u.ip6 = *dst;
131 	br_dst.proto = htons(ETH_P_IPV6);
132 
133 	return br_mdb_ip_get(mdb, &br_dst);
134 }
135 #endif
136 
137 struct net_bridge_mdb_entry *br_mdb_get(struct net_bridge *br,
138 					struct sk_buff *skb)
139 {
140 	struct net_bridge_mdb_htable *mdb = rcu_dereference(br->mdb);
141 	struct br_ip ip;
142 
143 	if (br->multicast_disabled)
144 		return NULL;
145 
146 	if (BR_INPUT_SKB_CB(skb)->igmp)
147 		return NULL;
148 
149 	ip.proto = skb->protocol;
150 
151 	switch (skb->protocol) {
152 	case htons(ETH_P_IP):
153 		ip.u.ip4 = ip_hdr(skb)->daddr;
154 		break;
155 #if IS_ENABLED(CONFIG_IPV6)
156 	case htons(ETH_P_IPV6):
157 		ip.u.ip6 = ipv6_hdr(skb)->daddr;
158 		break;
159 #endif
160 	default:
161 		return NULL;
162 	}
163 
164 	return br_mdb_ip_get(mdb, &ip);
165 }
166 
167 static void br_mdb_free(struct rcu_head *head)
168 {
169 	struct net_bridge_mdb_htable *mdb =
170 		container_of(head, struct net_bridge_mdb_htable, rcu);
171 	struct net_bridge_mdb_htable *old = mdb->old;
172 
173 	mdb->old = NULL;
174 	kfree(old->mhash);
175 	kfree(old);
176 }
177 
178 static int br_mdb_copy(struct net_bridge_mdb_htable *new,
179 		       struct net_bridge_mdb_htable *old,
180 		       int elasticity)
181 {
182 	struct net_bridge_mdb_entry *mp;
183 	struct hlist_node *p;
184 	int maxlen;
185 	int len;
186 	int i;
187 
188 	for (i = 0; i < old->max; i++)
189 		hlist_for_each_entry(mp, p, &old->mhash[i], hlist[old->ver])
190 			hlist_add_head(&mp->hlist[new->ver],
191 				       &new->mhash[br_ip_hash(new, &mp->addr)]);
192 
193 	if (!elasticity)
194 		return 0;
195 
196 	maxlen = 0;
197 	for (i = 0; i < new->max; i++) {
198 		len = 0;
199 		hlist_for_each_entry(mp, p, &new->mhash[i], hlist[new->ver])
200 			len++;
201 		if (len > maxlen)
202 			maxlen = len;
203 	}
204 
205 	return maxlen > elasticity ? -EINVAL : 0;
206 }
207 
208 static void br_multicast_free_pg(struct rcu_head *head)
209 {
210 	struct net_bridge_port_group *p =
211 		container_of(head, struct net_bridge_port_group, rcu);
212 
213 	kfree(p);
214 }
215 
216 static void br_multicast_free_group(struct rcu_head *head)
217 {
218 	struct net_bridge_mdb_entry *mp =
219 		container_of(head, struct net_bridge_mdb_entry, rcu);
220 
221 	kfree(mp);
222 }
223 
224 static void br_multicast_group_expired(unsigned long data)
225 {
226 	struct net_bridge_mdb_entry *mp = (void *)data;
227 	struct net_bridge *br = mp->br;
228 	struct net_bridge_mdb_htable *mdb;
229 
230 	spin_lock(&br->multicast_lock);
231 	if (!netif_running(br->dev) || timer_pending(&mp->timer))
232 		goto out;
233 
234 	mp->mglist = false;
235 
236 	if (mp->ports)
237 		goto out;
238 
239 	mdb = mlock_dereference(br->mdb, br);
240 
241 	hlist_del_rcu(&mp->hlist[mdb->ver]);
242 	mdb->size--;
243 
244 	call_rcu_bh(&mp->rcu, br_multicast_free_group);
245 
246 out:
247 	spin_unlock(&br->multicast_lock);
248 }
249 
250 static void br_multicast_del_pg(struct net_bridge *br,
251 				struct net_bridge_port_group *pg)
252 {
253 	struct net_bridge_mdb_htable *mdb;
254 	struct net_bridge_mdb_entry *mp;
255 	struct net_bridge_port_group *p;
256 	struct net_bridge_port_group __rcu **pp;
257 
258 	mdb = mlock_dereference(br->mdb, br);
259 
260 	mp = br_mdb_ip_get(mdb, &pg->addr);
261 	if (WARN_ON(!mp))
262 		return;
263 
264 	for (pp = &mp->ports;
265 	     (p = mlock_dereference(*pp, br)) != NULL;
266 	     pp = &p->next) {
267 		if (p != pg)
268 			continue;
269 
270 		rcu_assign_pointer(*pp, p->next);
271 		hlist_del_init(&p->mglist);
272 		del_timer(&p->timer);
273 		call_rcu_bh(&p->rcu, br_multicast_free_pg);
274 
275 		if (!mp->ports && !mp->mglist &&
276 		    netif_running(br->dev))
277 			mod_timer(&mp->timer, jiffies);
278 
279 		return;
280 	}
281 
282 	WARN_ON(1);
283 }
284 
285 static void br_multicast_port_group_expired(unsigned long data)
286 {
287 	struct net_bridge_port_group *pg = (void *)data;
288 	struct net_bridge *br = pg->port->br;
289 
290 	spin_lock(&br->multicast_lock);
291 	if (!netif_running(br->dev) || timer_pending(&pg->timer) ||
292 	    hlist_unhashed(&pg->mglist))
293 		goto out;
294 
295 	br_multicast_del_pg(br, pg);
296 
297 out:
298 	spin_unlock(&br->multicast_lock);
299 }
300 
301 static int br_mdb_rehash(struct net_bridge_mdb_htable __rcu **mdbp, int max,
302 			 int elasticity)
303 {
304 	struct net_bridge_mdb_htable *old = rcu_dereference_protected(*mdbp, 1);
305 	struct net_bridge_mdb_htable *mdb;
306 	int err;
307 
308 	mdb = kmalloc(sizeof(*mdb), GFP_ATOMIC);
309 	if (!mdb)
310 		return -ENOMEM;
311 
312 	mdb->max = max;
313 	mdb->old = old;
314 
315 	mdb->mhash = kzalloc(max * sizeof(*mdb->mhash), GFP_ATOMIC);
316 	if (!mdb->mhash) {
317 		kfree(mdb);
318 		return -ENOMEM;
319 	}
320 
321 	mdb->size = old ? old->size : 0;
322 	mdb->ver = old ? old->ver ^ 1 : 0;
323 
324 	if (!old || elasticity)
325 		get_random_bytes(&mdb->secret, sizeof(mdb->secret));
326 	else
327 		mdb->secret = old->secret;
328 
329 	if (!old)
330 		goto out;
331 
332 	err = br_mdb_copy(mdb, old, elasticity);
333 	if (err) {
334 		kfree(mdb->mhash);
335 		kfree(mdb);
336 		return err;
337 	}
338 
339 	call_rcu_bh(&mdb->rcu, br_mdb_free);
340 
341 out:
342 	rcu_assign_pointer(*mdbp, mdb);
343 
344 	return 0;
345 }
346 
347 static struct sk_buff *br_ip4_multicast_alloc_query(struct net_bridge *br,
348 						    __be32 group)
349 {
350 	struct sk_buff *skb;
351 	struct igmphdr *ih;
352 	struct ethhdr *eth;
353 	struct iphdr *iph;
354 
355 	skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*iph) +
356 						 sizeof(*ih) + 4);
357 	if (!skb)
358 		goto out;
359 
360 	skb->protocol = htons(ETH_P_IP);
361 
362 	skb_reset_mac_header(skb);
363 	eth = eth_hdr(skb);
364 
365 	memcpy(eth->h_source, br->dev->dev_addr, 6);
366 	eth->h_dest[0] = 1;
367 	eth->h_dest[1] = 0;
368 	eth->h_dest[2] = 0x5e;
369 	eth->h_dest[3] = 0;
370 	eth->h_dest[4] = 0;
371 	eth->h_dest[5] = 1;
372 	eth->h_proto = htons(ETH_P_IP);
373 	skb_put(skb, sizeof(*eth));
374 
375 	skb_set_network_header(skb, skb->len);
376 	iph = ip_hdr(skb);
377 
378 	iph->version = 4;
379 	iph->ihl = 6;
380 	iph->tos = 0xc0;
381 	iph->tot_len = htons(sizeof(*iph) + sizeof(*ih) + 4);
382 	iph->id = 0;
383 	iph->frag_off = htons(IP_DF);
384 	iph->ttl = 1;
385 	iph->protocol = IPPROTO_IGMP;
386 	iph->saddr = 0;
387 	iph->daddr = htonl(INADDR_ALLHOSTS_GROUP);
388 	((u8 *)&iph[1])[0] = IPOPT_RA;
389 	((u8 *)&iph[1])[1] = 4;
390 	((u8 *)&iph[1])[2] = 0;
391 	((u8 *)&iph[1])[3] = 0;
392 	ip_send_check(iph);
393 	skb_put(skb, 24);
394 
395 	skb_set_transport_header(skb, skb->len);
396 	ih = igmp_hdr(skb);
397 	ih->type = IGMP_HOST_MEMBERSHIP_QUERY;
398 	ih->code = (group ? br->multicast_last_member_interval :
399 			    br->multicast_query_response_interval) /
400 		   (HZ / IGMP_TIMER_SCALE);
401 	ih->group = group;
402 	ih->csum = 0;
403 	ih->csum = ip_compute_csum((void *)ih, sizeof(struct igmphdr));
404 	skb_put(skb, sizeof(*ih));
405 
406 	__skb_pull(skb, sizeof(*eth));
407 
408 out:
409 	return skb;
410 }
411 
412 #if IS_ENABLED(CONFIG_IPV6)
413 static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
414 						    const struct in6_addr *group)
415 {
416 	struct sk_buff *skb;
417 	struct ipv6hdr *ip6h;
418 	struct mld_msg *mldq;
419 	struct ethhdr *eth;
420 	u8 *hopopt;
421 	unsigned long interval;
422 
423 	skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*ip6h) +
424 						 8 + sizeof(*mldq));
425 	if (!skb)
426 		goto out;
427 
428 	skb->protocol = htons(ETH_P_IPV6);
429 
430 	/* Ethernet header */
431 	skb_reset_mac_header(skb);
432 	eth = eth_hdr(skb);
433 
434 	memcpy(eth->h_source, br->dev->dev_addr, 6);
435 	eth->h_proto = htons(ETH_P_IPV6);
436 	skb_put(skb, sizeof(*eth));
437 
438 	/* IPv6 header + HbH option */
439 	skb_set_network_header(skb, skb->len);
440 	ip6h = ipv6_hdr(skb);
441 
442 	*(__force __be32 *)ip6h = htonl(0x60000000);
443 	ip6h->payload_len = htons(8 + sizeof(*mldq));
444 	ip6h->nexthdr = IPPROTO_HOPOPTS;
445 	ip6h->hop_limit = 1;
446 	ipv6_addr_set(&ip6h->daddr, htonl(0xff020000), 0, 0, htonl(1));
447 	if (ipv6_dev_get_saddr(dev_net(br->dev), br->dev, &ip6h->daddr, 0,
448 			       &ip6h->saddr)) {
449 		kfree_skb(skb);
450 		return NULL;
451 	}
452 	ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
453 
454 	hopopt = (u8 *)(ip6h + 1);
455 	hopopt[0] = IPPROTO_ICMPV6;		/* next hdr */
456 	hopopt[1] = 0;				/* length of HbH */
457 	hopopt[2] = IPV6_TLV_ROUTERALERT;	/* Router Alert */
458 	hopopt[3] = 2;				/* Length of RA Option */
459 	hopopt[4] = 0;				/* Type = 0x0000 (MLD) */
460 	hopopt[5] = 0;
461 	hopopt[6] = IPV6_TLV_PAD0;		/* Pad0 */
462 	hopopt[7] = IPV6_TLV_PAD0;		/* Pad0 */
463 
464 	skb_put(skb, sizeof(*ip6h) + 8);
465 
466 	/* ICMPv6 */
467 	skb_set_transport_header(skb, skb->len);
468 	mldq = (struct mld_msg *) icmp6_hdr(skb);
469 
470 	interval = ipv6_addr_any(group) ? br->multicast_last_member_interval :
471 					  br->multicast_query_response_interval;
472 
473 	mldq->mld_type = ICMPV6_MGM_QUERY;
474 	mldq->mld_code = 0;
475 	mldq->mld_cksum = 0;
476 	mldq->mld_maxdelay = htons((u16)jiffies_to_msecs(interval));
477 	mldq->mld_reserved = 0;
478 	mldq->mld_mca = *group;
479 
480 	/* checksum */
481 	mldq->mld_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
482 					  sizeof(*mldq), IPPROTO_ICMPV6,
483 					  csum_partial(mldq,
484 						       sizeof(*mldq), 0));
485 	skb_put(skb, sizeof(*mldq));
486 
487 	__skb_pull(skb, sizeof(*eth));
488 
489 out:
490 	return skb;
491 }
492 #endif
493 
494 static struct sk_buff *br_multicast_alloc_query(struct net_bridge *br,
495 						struct br_ip *addr)
496 {
497 	switch (addr->proto) {
498 	case htons(ETH_P_IP):
499 		return br_ip4_multicast_alloc_query(br, addr->u.ip4);
500 #if IS_ENABLED(CONFIG_IPV6)
501 	case htons(ETH_P_IPV6):
502 		return br_ip6_multicast_alloc_query(br, &addr->u.ip6);
503 #endif
504 	}
505 	return NULL;
506 }
507 
508 static struct net_bridge_mdb_entry *br_multicast_get_group(
509 	struct net_bridge *br, struct net_bridge_port *port,
510 	struct br_ip *group, int hash)
511 {
512 	struct net_bridge_mdb_htable *mdb;
513 	struct net_bridge_mdb_entry *mp;
514 	struct hlist_node *p;
515 	unsigned count = 0;
516 	unsigned max;
517 	int elasticity;
518 	int err;
519 
520 	mdb = rcu_dereference_protected(br->mdb, 1);
521 	hlist_for_each_entry(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) {
522 		count++;
523 		if (unlikely(br_ip_equal(group, &mp->addr)))
524 			return mp;
525 	}
526 
527 	elasticity = 0;
528 	max = mdb->max;
529 
530 	if (unlikely(count > br->hash_elasticity && count)) {
531 		if (net_ratelimit())
532 			br_info(br, "Multicast hash table "
533 				"chain limit reached: %s\n",
534 				port ? port->dev->name : br->dev->name);
535 
536 		elasticity = br->hash_elasticity;
537 	}
538 
539 	if (mdb->size >= max) {
540 		max *= 2;
541 		if (unlikely(max >= br->hash_max)) {
542 			br_warn(br, "Multicast hash table maximum "
543 				"reached, disabling snooping: %s, %d\n",
544 				port ? port->dev->name : br->dev->name, max);
545 			err = -E2BIG;
546 disable:
547 			br->multicast_disabled = 1;
548 			goto err;
549 		}
550 	}
551 
552 	if (max > mdb->max || elasticity) {
553 		if (mdb->old) {
554 			if (net_ratelimit())
555 				br_info(br, "Multicast hash table "
556 					"on fire: %s\n",
557 					port ? port->dev->name : br->dev->name);
558 			err = -EEXIST;
559 			goto err;
560 		}
561 
562 		err = br_mdb_rehash(&br->mdb, max, elasticity);
563 		if (err) {
564 			br_warn(br, "Cannot rehash multicast "
565 				"hash table, disabling snooping: %s, %d, %d\n",
566 				port ? port->dev->name : br->dev->name,
567 				mdb->size, err);
568 			goto disable;
569 		}
570 
571 		err = -EAGAIN;
572 		goto err;
573 	}
574 
575 	return NULL;
576 
577 err:
578 	mp = ERR_PTR(err);
579 	return mp;
580 }
581 
582 static struct net_bridge_mdb_entry *br_multicast_new_group(
583 	struct net_bridge *br, struct net_bridge_port *port,
584 	struct br_ip *group)
585 {
586 	struct net_bridge_mdb_htable *mdb;
587 	struct net_bridge_mdb_entry *mp;
588 	int hash;
589 	int err;
590 
591 	mdb = rcu_dereference_protected(br->mdb, 1);
592 	if (!mdb) {
593 		err = br_mdb_rehash(&br->mdb, BR_HASH_SIZE, 0);
594 		if (err)
595 			return ERR_PTR(err);
596 		goto rehash;
597 	}
598 
599 	hash = br_ip_hash(mdb, group);
600 	mp = br_multicast_get_group(br, port, group, hash);
601 	switch (PTR_ERR(mp)) {
602 	case 0:
603 		break;
604 
605 	case -EAGAIN:
606 rehash:
607 		mdb = rcu_dereference_protected(br->mdb, 1);
608 		hash = br_ip_hash(mdb, group);
609 		break;
610 
611 	default:
612 		goto out;
613 	}
614 
615 	mp = kzalloc(sizeof(*mp), GFP_ATOMIC);
616 	if (unlikely(!mp))
617 		return ERR_PTR(-ENOMEM);
618 
619 	mp->br = br;
620 	mp->addr = *group;
621 	setup_timer(&mp->timer, br_multicast_group_expired,
622 		    (unsigned long)mp);
623 
624 	hlist_add_head_rcu(&mp->hlist[mdb->ver], &mdb->mhash[hash]);
625 	mdb->size++;
626 
627 out:
628 	return mp;
629 }
630 
631 static int br_multicast_add_group(struct net_bridge *br,
632 				  struct net_bridge_port *port,
633 				  struct br_ip *group)
634 {
635 	struct net_bridge_mdb_entry *mp;
636 	struct net_bridge_port_group *p;
637 	struct net_bridge_port_group __rcu **pp;
638 	unsigned long now = jiffies;
639 	int err;
640 
641 	spin_lock(&br->multicast_lock);
642 	if (!netif_running(br->dev) ||
643 	    (port && port->state == BR_STATE_DISABLED))
644 		goto out;
645 
646 	mp = br_multicast_new_group(br, port, group);
647 	err = PTR_ERR(mp);
648 	if (IS_ERR(mp))
649 		goto err;
650 
651 	if (!port) {
652 		mp->mglist = true;
653 		mod_timer(&mp->timer, now + br->multicast_membership_interval);
654 		goto out;
655 	}
656 
657 	for (pp = &mp->ports;
658 	     (p = mlock_dereference(*pp, br)) != NULL;
659 	     pp = &p->next) {
660 		if (p->port == port)
661 			goto found;
662 		if ((unsigned long)p->port < (unsigned long)port)
663 			break;
664 	}
665 
666 	p = kzalloc(sizeof(*p), GFP_ATOMIC);
667 	err = -ENOMEM;
668 	if (unlikely(!p))
669 		goto err;
670 
671 	p->addr = *group;
672 	p->port = port;
673 	p->next = *pp;
674 	hlist_add_head(&p->mglist, &port->mglist);
675 	setup_timer(&p->timer, br_multicast_port_group_expired,
676 		    (unsigned long)p);
677 
678 	rcu_assign_pointer(*pp, p);
679 
680 found:
681 	mod_timer(&p->timer, now + br->multicast_membership_interval);
682 out:
683 	err = 0;
684 
685 err:
686 	spin_unlock(&br->multicast_lock);
687 	return err;
688 }
689 
690 static int br_ip4_multicast_add_group(struct net_bridge *br,
691 				      struct net_bridge_port *port,
692 				      __be32 group)
693 {
694 	struct br_ip br_group;
695 
696 	if (ipv4_is_local_multicast(group))
697 		return 0;
698 
699 	br_group.u.ip4 = group;
700 	br_group.proto = htons(ETH_P_IP);
701 
702 	return br_multicast_add_group(br, port, &br_group);
703 }
704 
705 #if IS_ENABLED(CONFIG_IPV6)
706 static int br_ip6_multicast_add_group(struct net_bridge *br,
707 				      struct net_bridge_port *port,
708 				      const struct in6_addr *group)
709 {
710 	struct br_ip br_group;
711 
712 	if (!ipv6_is_transient_multicast(group))
713 		return 0;
714 
715 	br_group.u.ip6 = *group;
716 	br_group.proto = htons(ETH_P_IPV6);
717 
718 	return br_multicast_add_group(br, port, &br_group);
719 }
720 #endif
721 
722 static void br_multicast_router_expired(unsigned long data)
723 {
724 	struct net_bridge_port *port = (void *)data;
725 	struct net_bridge *br = port->br;
726 
727 	spin_lock(&br->multicast_lock);
728 	if (port->multicast_router != 1 ||
729 	    timer_pending(&port->multicast_router_timer) ||
730 	    hlist_unhashed(&port->rlist))
731 		goto out;
732 
733 	hlist_del_init_rcu(&port->rlist);
734 
735 out:
736 	spin_unlock(&br->multicast_lock);
737 }
738 
739 static void br_multicast_local_router_expired(unsigned long data)
740 {
741 }
742 
743 static void __br_multicast_send_query(struct net_bridge *br,
744 				      struct net_bridge_port *port,
745 				      struct br_ip *ip)
746 {
747 	struct sk_buff *skb;
748 
749 	skb = br_multicast_alloc_query(br, ip);
750 	if (!skb)
751 		return;
752 
753 	if (port) {
754 		__skb_push(skb, sizeof(struct ethhdr));
755 		skb->dev = port->dev;
756 		NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
757 			dev_queue_xmit);
758 	} else
759 		netif_rx(skb);
760 }
761 
762 static void br_multicast_send_query(struct net_bridge *br,
763 				    struct net_bridge_port *port, u32 sent)
764 {
765 	unsigned long time;
766 	struct br_ip br_group;
767 
768 	if (!netif_running(br->dev) || br->multicast_disabled ||
769 	    timer_pending(&br->multicast_querier_timer))
770 		return;
771 
772 	memset(&br_group.u, 0, sizeof(br_group.u));
773 
774 	br_group.proto = htons(ETH_P_IP);
775 	__br_multicast_send_query(br, port, &br_group);
776 
777 #if IS_ENABLED(CONFIG_IPV6)
778 	br_group.proto = htons(ETH_P_IPV6);
779 	__br_multicast_send_query(br, port, &br_group);
780 #endif
781 
782 	time = jiffies;
783 	time += sent < br->multicast_startup_query_count ?
784 		br->multicast_startup_query_interval :
785 		br->multicast_query_interval;
786 	mod_timer(port ? &port->multicast_query_timer :
787 			 &br->multicast_query_timer, time);
788 }
789 
790 static void br_multicast_port_query_expired(unsigned long data)
791 {
792 	struct net_bridge_port *port = (void *)data;
793 	struct net_bridge *br = port->br;
794 
795 	spin_lock(&br->multicast_lock);
796 	if (port->state == BR_STATE_DISABLED ||
797 	    port->state == BR_STATE_BLOCKING)
798 		goto out;
799 
800 	if (port->multicast_startup_queries_sent <
801 	    br->multicast_startup_query_count)
802 		port->multicast_startup_queries_sent++;
803 
804 	br_multicast_send_query(port->br, port,
805 				port->multicast_startup_queries_sent);
806 
807 out:
808 	spin_unlock(&br->multicast_lock);
809 }
810 
811 void br_multicast_add_port(struct net_bridge_port *port)
812 {
813 	port->multicast_router = 1;
814 
815 	setup_timer(&port->multicast_router_timer, br_multicast_router_expired,
816 		    (unsigned long)port);
817 	setup_timer(&port->multicast_query_timer,
818 		    br_multicast_port_query_expired, (unsigned long)port);
819 }
820 
821 void br_multicast_del_port(struct net_bridge_port *port)
822 {
823 	del_timer_sync(&port->multicast_router_timer);
824 }
825 
826 static void __br_multicast_enable_port(struct net_bridge_port *port)
827 {
828 	port->multicast_startup_queries_sent = 0;
829 
830 	if (try_to_del_timer_sync(&port->multicast_query_timer) >= 0 ||
831 	    del_timer(&port->multicast_query_timer))
832 		mod_timer(&port->multicast_query_timer, jiffies);
833 }
834 
835 void br_multicast_enable_port(struct net_bridge_port *port)
836 {
837 	struct net_bridge *br = port->br;
838 
839 	spin_lock(&br->multicast_lock);
840 	if (br->multicast_disabled || !netif_running(br->dev))
841 		goto out;
842 
843 	__br_multicast_enable_port(port);
844 
845 out:
846 	spin_unlock(&br->multicast_lock);
847 }
848 
849 void br_multicast_disable_port(struct net_bridge_port *port)
850 {
851 	struct net_bridge *br = port->br;
852 	struct net_bridge_port_group *pg;
853 	struct hlist_node *p, *n;
854 
855 	spin_lock(&br->multicast_lock);
856 	hlist_for_each_entry_safe(pg, p, n, &port->mglist, mglist)
857 		br_multicast_del_pg(br, pg);
858 
859 	if (!hlist_unhashed(&port->rlist))
860 		hlist_del_init_rcu(&port->rlist);
861 	del_timer(&port->multicast_router_timer);
862 	del_timer(&port->multicast_query_timer);
863 	spin_unlock(&br->multicast_lock);
864 }
865 
866 static int br_ip4_multicast_igmp3_report(struct net_bridge *br,
867 					 struct net_bridge_port *port,
868 					 struct sk_buff *skb)
869 {
870 	struct igmpv3_report *ih;
871 	struct igmpv3_grec *grec;
872 	int i;
873 	int len;
874 	int num;
875 	int type;
876 	int err = 0;
877 	__be32 group;
878 
879 	if (!pskb_may_pull(skb, sizeof(*ih)))
880 		return -EINVAL;
881 
882 	ih = igmpv3_report_hdr(skb);
883 	num = ntohs(ih->ngrec);
884 	len = sizeof(*ih);
885 
886 	for (i = 0; i < num; i++) {
887 		len += sizeof(*grec);
888 		if (!pskb_may_pull(skb, len))
889 			return -EINVAL;
890 
891 		grec = (void *)(skb->data + len - sizeof(*grec));
892 		group = grec->grec_mca;
893 		type = grec->grec_type;
894 
895 		len += ntohs(grec->grec_nsrcs) * 4;
896 		if (!pskb_may_pull(skb, len))
897 			return -EINVAL;
898 
899 		/* We treat this as an IGMPv2 report for now. */
900 		switch (type) {
901 		case IGMPV3_MODE_IS_INCLUDE:
902 		case IGMPV3_MODE_IS_EXCLUDE:
903 		case IGMPV3_CHANGE_TO_INCLUDE:
904 		case IGMPV3_CHANGE_TO_EXCLUDE:
905 		case IGMPV3_ALLOW_NEW_SOURCES:
906 		case IGMPV3_BLOCK_OLD_SOURCES:
907 			break;
908 
909 		default:
910 			continue;
911 		}
912 
913 		err = br_ip4_multicast_add_group(br, port, group);
914 		if (err)
915 			break;
916 	}
917 
918 	return err;
919 }
920 
921 #if IS_ENABLED(CONFIG_IPV6)
922 static int br_ip6_multicast_mld2_report(struct net_bridge *br,
923 					struct net_bridge_port *port,
924 					struct sk_buff *skb)
925 {
926 	struct icmp6hdr *icmp6h;
927 	struct mld2_grec *grec;
928 	int i;
929 	int len;
930 	int num;
931 	int err = 0;
932 
933 	if (!pskb_may_pull(skb, sizeof(*icmp6h)))
934 		return -EINVAL;
935 
936 	icmp6h = icmp6_hdr(skb);
937 	num = ntohs(icmp6h->icmp6_dataun.un_data16[1]);
938 	len = sizeof(*icmp6h);
939 
940 	for (i = 0; i < num; i++) {
941 		__be16 *nsrcs, _nsrcs;
942 
943 		nsrcs = skb_header_pointer(skb,
944 					   len + offsetof(struct mld2_grec,
945 							  grec_nsrcs),
946 					   sizeof(_nsrcs), &_nsrcs);
947 		if (!nsrcs)
948 			return -EINVAL;
949 
950 		if (!pskb_may_pull(skb,
951 				   len + sizeof(*grec) +
952 				   sizeof(struct in6_addr) * ntohs(*nsrcs)))
953 			return -EINVAL;
954 
955 		grec = (struct mld2_grec *)(skb->data + len);
956 		len += sizeof(*grec) +
957 		       sizeof(struct in6_addr) * ntohs(*nsrcs);
958 
959 		/* We treat these as MLDv1 reports for now. */
960 		switch (grec->grec_type) {
961 		case MLD2_MODE_IS_INCLUDE:
962 		case MLD2_MODE_IS_EXCLUDE:
963 		case MLD2_CHANGE_TO_INCLUDE:
964 		case MLD2_CHANGE_TO_EXCLUDE:
965 		case MLD2_ALLOW_NEW_SOURCES:
966 		case MLD2_BLOCK_OLD_SOURCES:
967 			break;
968 
969 		default:
970 			continue;
971 		}
972 
973 		err = br_ip6_multicast_add_group(br, port, &grec->grec_mca);
974 		if (!err)
975 			break;
976 	}
977 
978 	return err;
979 }
980 #endif
981 
982 /*
983  * Add port to rotuer_list
984  *  list is maintained ordered by pointer value
985  *  and locked by br->multicast_lock and RCU
986  */
987 static void br_multicast_add_router(struct net_bridge *br,
988 				    struct net_bridge_port *port)
989 {
990 	struct net_bridge_port *p;
991 	struct hlist_node *n, *slot = NULL;
992 
993 	hlist_for_each_entry(p, n, &br->router_list, rlist) {
994 		if ((unsigned long) port >= (unsigned long) p)
995 			break;
996 		slot = n;
997 	}
998 
999 	if (slot)
1000 		hlist_add_after_rcu(slot, &port->rlist);
1001 	else
1002 		hlist_add_head_rcu(&port->rlist, &br->router_list);
1003 }
1004 
1005 static void br_multicast_mark_router(struct net_bridge *br,
1006 				     struct net_bridge_port *port)
1007 {
1008 	unsigned long now = jiffies;
1009 
1010 	if (!port) {
1011 		if (br->multicast_router == 1)
1012 			mod_timer(&br->multicast_router_timer,
1013 				  now + br->multicast_querier_interval);
1014 		return;
1015 	}
1016 
1017 	if (port->multicast_router != 1)
1018 		return;
1019 
1020 	if (!hlist_unhashed(&port->rlist))
1021 		goto timer;
1022 
1023 	br_multicast_add_router(br, port);
1024 
1025 timer:
1026 	mod_timer(&port->multicast_router_timer,
1027 		  now + br->multicast_querier_interval);
1028 }
1029 
1030 static void br_multicast_query_received(struct net_bridge *br,
1031 					struct net_bridge_port *port,
1032 					int saddr)
1033 {
1034 	if (saddr)
1035 		mod_timer(&br->multicast_querier_timer,
1036 			  jiffies + br->multicast_querier_interval);
1037 	else if (timer_pending(&br->multicast_querier_timer))
1038 		return;
1039 
1040 	br_multicast_mark_router(br, port);
1041 }
1042 
1043 static int br_ip4_multicast_query(struct net_bridge *br,
1044 				  struct net_bridge_port *port,
1045 				  struct sk_buff *skb)
1046 {
1047 	const struct iphdr *iph = ip_hdr(skb);
1048 	struct igmphdr *ih = igmp_hdr(skb);
1049 	struct net_bridge_mdb_entry *mp;
1050 	struct igmpv3_query *ih3;
1051 	struct net_bridge_port_group *p;
1052 	struct net_bridge_port_group __rcu **pp;
1053 	unsigned long max_delay;
1054 	unsigned long now = jiffies;
1055 	__be32 group;
1056 	int err = 0;
1057 
1058 	spin_lock(&br->multicast_lock);
1059 	if (!netif_running(br->dev) ||
1060 	    (port && port->state == BR_STATE_DISABLED))
1061 		goto out;
1062 
1063 	br_multicast_query_received(br, port, !!iph->saddr);
1064 
1065 	group = ih->group;
1066 
1067 	if (skb->len == sizeof(*ih)) {
1068 		max_delay = ih->code * (HZ / IGMP_TIMER_SCALE);
1069 
1070 		if (!max_delay) {
1071 			max_delay = 10 * HZ;
1072 			group = 0;
1073 		}
1074 	} else {
1075 		if (!pskb_may_pull(skb, sizeof(struct igmpv3_query))) {
1076 			err = -EINVAL;
1077 			goto out;
1078 		}
1079 
1080 		ih3 = igmpv3_query_hdr(skb);
1081 		if (ih3->nsrcs)
1082 			goto out;
1083 
1084 		max_delay = ih3->code ?
1085 			    IGMPV3_MRC(ih3->code) * (HZ / IGMP_TIMER_SCALE) : 1;
1086 	}
1087 
1088 	if (!group)
1089 		goto out;
1090 
1091 	mp = br_mdb_ip4_get(mlock_dereference(br->mdb, br), group);
1092 	if (!mp)
1093 		goto out;
1094 
1095 	max_delay *= br->multicast_last_member_count;
1096 
1097 	if (mp->mglist &&
1098 	    (timer_pending(&mp->timer) ?
1099 	     time_after(mp->timer.expires, now + max_delay) :
1100 	     try_to_del_timer_sync(&mp->timer) >= 0))
1101 		mod_timer(&mp->timer, now + max_delay);
1102 
1103 	for (pp = &mp->ports;
1104 	     (p = mlock_dereference(*pp, br)) != NULL;
1105 	     pp = &p->next) {
1106 		if (timer_pending(&p->timer) ?
1107 		    time_after(p->timer.expires, now + max_delay) :
1108 		    try_to_del_timer_sync(&p->timer) >= 0)
1109 			mod_timer(&p->timer, now + max_delay);
1110 	}
1111 
1112 out:
1113 	spin_unlock(&br->multicast_lock);
1114 	return err;
1115 }
1116 
1117 #if IS_ENABLED(CONFIG_IPV6)
1118 static int br_ip6_multicast_query(struct net_bridge *br,
1119 				  struct net_bridge_port *port,
1120 				  struct sk_buff *skb)
1121 {
1122 	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
1123 	struct mld_msg *mld = (struct mld_msg *) icmp6_hdr(skb);
1124 	struct net_bridge_mdb_entry *mp;
1125 	struct mld2_query *mld2q;
1126 	struct net_bridge_port_group *p;
1127 	struct net_bridge_port_group __rcu **pp;
1128 	unsigned long max_delay;
1129 	unsigned long now = jiffies;
1130 	const struct in6_addr *group = NULL;
1131 	int err = 0;
1132 
1133 	spin_lock(&br->multicast_lock);
1134 	if (!netif_running(br->dev) ||
1135 	    (port && port->state == BR_STATE_DISABLED))
1136 		goto out;
1137 
1138 	br_multicast_query_received(br, port, !ipv6_addr_any(&ip6h->saddr));
1139 
1140 	if (skb->len == sizeof(*mld)) {
1141 		if (!pskb_may_pull(skb, sizeof(*mld))) {
1142 			err = -EINVAL;
1143 			goto out;
1144 		}
1145 		mld = (struct mld_msg *) icmp6_hdr(skb);
1146 		max_delay = msecs_to_jiffies(htons(mld->mld_maxdelay));
1147 		if (max_delay)
1148 			group = &mld->mld_mca;
1149 	} else if (skb->len >= sizeof(*mld2q)) {
1150 		if (!pskb_may_pull(skb, sizeof(*mld2q))) {
1151 			err = -EINVAL;
1152 			goto out;
1153 		}
1154 		mld2q = (struct mld2_query *)icmp6_hdr(skb);
1155 		if (!mld2q->mld2q_nsrcs)
1156 			group = &mld2q->mld2q_mca;
1157 		max_delay = mld2q->mld2q_mrc ? MLDV2_MRC(mld2q->mld2q_mrc) : 1;
1158 	}
1159 
1160 	if (!group)
1161 		goto out;
1162 
1163 	mp = br_mdb_ip6_get(mlock_dereference(br->mdb, br), group);
1164 	if (!mp)
1165 		goto out;
1166 
1167 	max_delay *= br->multicast_last_member_count;
1168 	if (mp->mglist &&
1169 	    (timer_pending(&mp->timer) ?
1170 	     time_after(mp->timer.expires, now + max_delay) :
1171 	     try_to_del_timer_sync(&mp->timer) >= 0))
1172 		mod_timer(&mp->timer, now + max_delay);
1173 
1174 	for (pp = &mp->ports;
1175 	     (p = mlock_dereference(*pp, br)) != NULL;
1176 	     pp = &p->next) {
1177 		if (timer_pending(&p->timer) ?
1178 		    time_after(p->timer.expires, now + max_delay) :
1179 		    try_to_del_timer_sync(&p->timer) >= 0)
1180 			mod_timer(&p->timer, now + max_delay);
1181 	}
1182 
1183 out:
1184 	spin_unlock(&br->multicast_lock);
1185 	return err;
1186 }
1187 #endif
1188 
1189 static void br_multicast_leave_group(struct net_bridge *br,
1190 				     struct net_bridge_port *port,
1191 				     struct br_ip *group)
1192 {
1193 	struct net_bridge_mdb_htable *mdb;
1194 	struct net_bridge_mdb_entry *mp;
1195 	struct net_bridge_port_group *p;
1196 	unsigned long now;
1197 	unsigned long time;
1198 
1199 	spin_lock(&br->multicast_lock);
1200 	if (!netif_running(br->dev) ||
1201 	    (port && port->state == BR_STATE_DISABLED) ||
1202 	    timer_pending(&br->multicast_querier_timer))
1203 		goto out;
1204 
1205 	mdb = mlock_dereference(br->mdb, br);
1206 	mp = br_mdb_ip_get(mdb, group);
1207 	if (!mp)
1208 		goto out;
1209 
1210 	now = jiffies;
1211 	time = now + br->multicast_last_member_count *
1212 		     br->multicast_last_member_interval;
1213 
1214 	if (!port) {
1215 		if (mp->mglist &&
1216 		    (timer_pending(&mp->timer) ?
1217 		     time_after(mp->timer.expires, time) :
1218 		     try_to_del_timer_sync(&mp->timer) >= 0)) {
1219 			mod_timer(&mp->timer, time);
1220 		}
1221 
1222 		goto out;
1223 	}
1224 
1225 	for (p = mlock_dereference(mp->ports, br);
1226 	     p != NULL;
1227 	     p = mlock_dereference(p->next, br)) {
1228 		if (p->port != port)
1229 			continue;
1230 
1231 		if (!hlist_unhashed(&p->mglist) &&
1232 		    (timer_pending(&p->timer) ?
1233 		     time_after(p->timer.expires, time) :
1234 		     try_to_del_timer_sync(&p->timer) >= 0)) {
1235 			mod_timer(&p->timer, time);
1236 		}
1237 
1238 		break;
1239 	}
1240 
1241 out:
1242 	spin_unlock(&br->multicast_lock);
1243 }
1244 
1245 static void br_ip4_multicast_leave_group(struct net_bridge *br,
1246 					 struct net_bridge_port *port,
1247 					 __be32 group)
1248 {
1249 	struct br_ip br_group;
1250 
1251 	if (ipv4_is_local_multicast(group))
1252 		return;
1253 
1254 	br_group.u.ip4 = group;
1255 	br_group.proto = htons(ETH_P_IP);
1256 
1257 	br_multicast_leave_group(br, port, &br_group);
1258 }
1259 
1260 #if IS_ENABLED(CONFIG_IPV6)
1261 static void br_ip6_multicast_leave_group(struct net_bridge *br,
1262 					 struct net_bridge_port *port,
1263 					 const struct in6_addr *group)
1264 {
1265 	struct br_ip br_group;
1266 
1267 	if (!ipv6_is_transient_multicast(group))
1268 		return;
1269 
1270 	br_group.u.ip6 = *group;
1271 	br_group.proto = htons(ETH_P_IPV6);
1272 
1273 	br_multicast_leave_group(br, port, &br_group);
1274 }
1275 #endif
1276 
1277 static int br_multicast_ipv4_rcv(struct net_bridge *br,
1278 				 struct net_bridge_port *port,
1279 				 struct sk_buff *skb)
1280 {
1281 	struct sk_buff *skb2 = skb;
1282 	const struct iphdr *iph;
1283 	struct igmphdr *ih;
1284 	unsigned len;
1285 	unsigned offset;
1286 	int err;
1287 
1288 	/* We treat OOM as packet loss for now. */
1289 	if (!pskb_may_pull(skb, sizeof(*iph)))
1290 		return -EINVAL;
1291 
1292 	iph = ip_hdr(skb);
1293 
1294 	if (iph->ihl < 5 || iph->version != 4)
1295 		return -EINVAL;
1296 
1297 	if (!pskb_may_pull(skb, ip_hdrlen(skb)))
1298 		return -EINVAL;
1299 
1300 	iph = ip_hdr(skb);
1301 
1302 	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1303 		return -EINVAL;
1304 
1305 	if (iph->protocol != IPPROTO_IGMP) {
1306 		if ((iph->daddr & IGMP_LOCAL_GROUP_MASK) != IGMP_LOCAL_GROUP)
1307 			BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
1308 		return 0;
1309 	}
1310 
1311 	len = ntohs(iph->tot_len);
1312 	if (skb->len < len || len < ip_hdrlen(skb))
1313 		return -EINVAL;
1314 
1315 	if (skb->len > len) {
1316 		skb2 = skb_clone(skb, GFP_ATOMIC);
1317 		if (!skb2)
1318 			return -ENOMEM;
1319 
1320 		err = pskb_trim_rcsum(skb2, len);
1321 		if (err)
1322 			goto err_out;
1323 	}
1324 
1325 	len -= ip_hdrlen(skb2);
1326 	offset = skb_network_offset(skb2) + ip_hdrlen(skb2);
1327 	__skb_pull(skb2, offset);
1328 	skb_reset_transport_header(skb2);
1329 
1330 	err = -EINVAL;
1331 	if (!pskb_may_pull(skb2, sizeof(*ih)))
1332 		goto out;
1333 
1334 	switch (skb2->ip_summed) {
1335 	case CHECKSUM_COMPLETE:
1336 		if (!csum_fold(skb2->csum))
1337 			break;
1338 		/* fall through */
1339 	case CHECKSUM_NONE:
1340 		skb2->csum = 0;
1341 		if (skb_checksum_complete(skb2))
1342 			goto out;
1343 	}
1344 
1345 	err = 0;
1346 
1347 	BR_INPUT_SKB_CB(skb)->igmp = 1;
1348 	ih = igmp_hdr(skb2);
1349 
1350 	switch (ih->type) {
1351 	case IGMP_HOST_MEMBERSHIP_REPORT:
1352 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
1353 		BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
1354 		err = br_ip4_multicast_add_group(br, port, ih->group);
1355 		break;
1356 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
1357 		err = br_ip4_multicast_igmp3_report(br, port, skb2);
1358 		break;
1359 	case IGMP_HOST_MEMBERSHIP_QUERY:
1360 		err = br_ip4_multicast_query(br, port, skb2);
1361 		break;
1362 	case IGMP_HOST_LEAVE_MESSAGE:
1363 		br_ip4_multicast_leave_group(br, port, ih->group);
1364 		break;
1365 	}
1366 
1367 out:
1368 	__skb_push(skb2, offset);
1369 err_out:
1370 	if (skb2 != skb)
1371 		kfree_skb(skb2);
1372 	return err;
1373 }
1374 
1375 #if IS_ENABLED(CONFIG_IPV6)
1376 static int br_multicast_ipv6_rcv(struct net_bridge *br,
1377 				 struct net_bridge_port *port,
1378 				 struct sk_buff *skb)
1379 {
1380 	struct sk_buff *skb2;
1381 	const struct ipv6hdr *ip6h;
1382 	u8 icmp6_type;
1383 	u8 nexthdr;
1384 	__be16 frag_off;
1385 	unsigned len;
1386 	int offset;
1387 	int err;
1388 
1389 	if (!pskb_may_pull(skb, sizeof(*ip6h)))
1390 		return -EINVAL;
1391 
1392 	ip6h = ipv6_hdr(skb);
1393 
1394 	/*
1395 	 * We're interested in MLD messages only.
1396 	 *  - Version is 6
1397 	 *  - MLD has always Router Alert hop-by-hop option
1398 	 *  - But we do not support jumbrograms.
1399 	 */
1400 	if (ip6h->version != 6 ||
1401 	    ip6h->nexthdr != IPPROTO_HOPOPTS ||
1402 	    ip6h->payload_len == 0)
1403 		return 0;
1404 
1405 	len = ntohs(ip6h->payload_len) + sizeof(*ip6h);
1406 	if (skb->len < len)
1407 		return -EINVAL;
1408 
1409 	nexthdr = ip6h->nexthdr;
1410 	offset = ipv6_skip_exthdr(skb, sizeof(*ip6h), &nexthdr, &frag_off);
1411 
1412 	if (offset < 0 || nexthdr != IPPROTO_ICMPV6)
1413 		return 0;
1414 
1415 	/* Okay, we found ICMPv6 header */
1416 	skb2 = skb_clone(skb, GFP_ATOMIC);
1417 	if (!skb2)
1418 		return -ENOMEM;
1419 
1420 	err = -EINVAL;
1421 	if (!pskb_may_pull(skb2, offset + sizeof(struct icmp6hdr)))
1422 		goto out;
1423 
1424 	len -= offset - skb_network_offset(skb2);
1425 
1426 	__skb_pull(skb2, offset);
1427 	skb_reset_transport_header(skb2);
1428 	skb_postpull_rcsum(skb2, skb_network_header(skb2),
1429 			   skb_network_header_len(skb2));
1430 
1431 	icmp6_type = icmp6_hdr(skb2)->icmp6_type;
1432 
1433 	switch (icmp6_type) {
1434 	case ICMPV6_MGM_QUERY:
1435 	case ICMPV6_MGM_REPORT:
1436 	case ICMPV6_MGM_REDUCTION:
1437 	case ICMPV6_MLD2_REPORT:
1438 		break;
1439 	default:
1440 		err = 0;
1441 		goto out;
1442 	}
1443 
1444 	/* Okay, we found MLD message. Check further. */
1445 	if (skb2->len > len) {
1446 		err = pskb_trim_rcsum(skb2, len);
1447 		if (err)
1448 			goto out;
1449 		err = -EINVAL;
1450 	}
1451 
1452 	ip6h = ipv6_hdr(skb2);
1453 
1454 	switch (skb2->ip_summed) {
1455 	case CHECKSUM_COMPLETE:
1456 		if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, skb2->len,
1457 					IPPROTO_ICMPV6, skb2->csum))
1458 			break;
1459 		/*FALLTHROUGH*/
1460 	case CHECKSUM_NONE:
1461 		skb2->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr,
1462 							&ip6h->daddr,
1463 							skb2->len,
1464 							IPPROTO_ICMPV6, 0));
1465 		if (__skb_checksum_complete(skb2))
1466 			goto out;
1467 	}
1468 
1469 	err = 0;
1470 
1471 	BR_INPUT_SKB_CB(skb)->igmp = 1;
1472 
1473 	switch (icmp6_type) {
1474 	case ICMPV6_MGM_REPORT:
1475 	    {
1476 		struct mld_msg *mld;
1477 		if (!pskb_may_pull(skb2, sizeof(*mld))) {
1478 			err = -EINVAL;
1479 			goto out;
1480 		}
1481 		mld = (struct mld_msg *)skb_transport_header(skb2);
1482 		BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
1483 		err = br_ip6_multicast_add_group(br, port, &mld->mld_mca);
1484 		break;
1485 	    }
1486 	case ICMPV6_MLD2_REPORT:
1487 		err = br_ip6_multicast_mld2_report(br, port, skb2);
1488 		break;
1489 	case ICMPV6_MGM_QUERY:
1490 		err = br_ip6_multicast_query(br, port, skb2);
1491 		break;
1492 	case ICMPV6_MGM_REDUCTION:
1493 	    {
1494 		struct mld_msg *mld;
1495 		if (!pskb_may_pull(skb2, sizeof(*mld))) {
1496 			err = -EINVAL;
1497 			goto out;
1498 		}
1499 		mld = (struct mld_msg *)skb_transport_header(skb2);
1500 		br_ip6_multicast_leave_group(br, port, &mld->mld_mca);
1501 	    }
1502 	}
1503 
1504 out:
1505 	kfree_skb(skb2);
1506 	return err;
1507 }
1508 #endif
1509 
1510 int br_multicast_rcv(struct net_bridge *br, struct net_bridge_port *port,
1511 		     struct sk_buff *skb)
1512 {
1513 	BR_INPUT_SKB_CB(skb)->igmp = 0;
1514 	BR_INPUT_SKB_CB(skb)->mrouters_only = 0;
1515 
1516 	if (br->multicast_disabled)
1517 		return 0;
1518 
1519 	switch (skb->protocol) {
1520 	case htons(ETH_P_IP):
1521 		return br_multicast_ipv4_rcv(br, port, skb);
1522 #if IS_ENABLED(CONFIG_IPV6)
1523 	case htons(ETH_P_IPV6):
1524 		return br_multicast_ipv6_rcv(br, port, skb);
1525 #endif
1526 	}
1527 
1528 	return 0;
1529 }
1530 
1531 static void br_multicast_query_expired(unsigned long data)
1532 {
1533 	struct net_bridge *br = (void *)data;
1534 
1535 	spin_lock(&br->multicast_lock);
1536 	if (br->multicast_startup_queries_sent <
1537 	    br->multicast_startup_query_count)
1538 		br->multicast_startup_queries_sent++;
1539 
1540 	br_multicast_send_query(br, NULL, br->multicast_startup_queries_sent);
1541 
1542 	spin_unlock(&br->multicast_lock);
1543 }
1544 
1545 void br_multicast_init(struct net_bridge *br)
1546 {
1547 	br->hash_elasticity = 4;
1548 	br->hash_max = 512;
1549 
1550 	br->multicast_router = 1;
1551 	br->multicast_last_member_count = 2;
1552 	br->multicast_startup_query_count = 2;
1553 
1554 	br->multicast_last_member_interval = HZ;
1555 	br->multicast_query_response_interval = 10 * HZ;
1556 	br->multicast_startup_query_interval = 125 * HZ / 4;
1557 	br->multicast_query_interval = 125 * HZ;
1558 	br->multicast_querier_interval = 255 * HZ;
1559 	br->multicast_membership_interval = 260 * HZ;
1560 
1561 	spin_lock_init(&br->multicast_lock);
1562 	setup_timer(&br->multicast_router_timer,
1563 		    br_multicast_local_router_expired, 0);
1564 	setup_timer(&br->multicast_querier_timer,
1565 		    br_multicast_local_router_expired, 0);
1566 	setup_timer(&br->multicast_query_timer, br_multicast_query_expired,
1567 		    (unsigned long)br);
1568 }
1569 
1570 void br_multicast_open(struct net_bridge *br)
1571 {
1572 	br->multicast_startup_queries_sent = 0;
1573 
1574 	if (br->multicast_disabled)
1575 		return;
1576 
1577 	mod_timer(&br->multicast_query_timer, jiffies);
1578 }
1579 
1580 void br_multicast_stop(struct net_bridge *br)
1581 {
1582 	struct net_bridge_mdb_htable *mdb;
1583 	struct net_bridge_mdb_entry *mp;
1584 	struct hlist_node *p, *n;
1585 	u32 ver;
1586 	int i;
1587 
1588 	del_timer_sync(&br->multicast_router_timer);
1589 	del_timer_sync(&br->multicast_querier_timer);
1590 	del_timer_sync(&br->multicast_query_timer);
1591 
1592 	spin_lock_bh(&br->multicast_lock);
1593 	mdb = mlock_dereference(br->mdb, br);
1594 	if (!mdb)
1595 		goto out;
1596 
1597 	br->mdb = NULL;
1598 
1599 	ver = mdb->ver;
1600 	for (i = 0; i < mdb->max; i++) {
1601 		hlist_for_each_entry_safe(mp, p, n, &mdb->mhash[i],
1602 					  hlist[ver]) {
1603 			del_timer(&mp->timer);
1604 			call_rcu_bh(&mp->rcu, br_multicast_free_group);
1605 		}
1606 	}
1607 
1608 	if (mdb->old) {
1609 		spin_unlock_bh(&br->multicast_lock);
1610 		rcu_barrier_bh();
1611 		spin_lock_bh(&br->multicast_lock);
1612 		WARN_ON(mdb->old);
1613 	}
1614 
1615 	mdb->old = mdb;
1616 	call_rcu_bh(&mdb->rcu, br_mdb_free);
1617 
1618 out:
1619 	spin_unlock_bh(&br->multicast_lock);
1620 }
1621 
1622 int br_multicast_set_router(struct net_bridge *br, unsigned long val)
1623 {
1624 	int err = -ENOENT;
1625 
1626 	spin_lock_bh(&br->multicast_lock);
1627 	if (!netif_running(br->dev))
1628 		goto unlock;
1629 
1630 	switch (val) {
1631 	case 0:
1632 	case 2:
1633 		del_timer(&br->multicast_router_timer);
1634 		/* fall through */
1635 	case 1:
1636 		br->multicast_router = val;
1637 		err = 0;
1638 		break;
1639 
1640 	default:
1641 		err = -EINVAL;
1642 		break;
1643 	}
1644 
1645 unlock:
1646 	spin_unlock_bh(&br->multicast_lock);
1647 
1648 	return err;
1649 }
1650 
1651 int br_multicast_set_port_router(struct net_bridge_port *p, unsigned long val)
1652 {
1653 	struct net_bridge *br = p->br;
1654 	int err = -ENOENT;
1655 
1656 	spin_lock(&br->multicast_lock);
1657 	if (!netif_running(br->dev) || p->state == BR_STATE_DISABLED)
1658 		goto unlock;
1659 
1660 	switch (val) {
1661 	case 0:
1662 	case 1:
1663 	case 2:
1664 		p->multicast_router = val;
1665 		err = 0;
1666 
1667 		if (val < 2 && !hlist_unhashed(&p->rlist))
1668 			hlist_del_init_rcu(&p->rlist);
1669 
1670 		if (val == 1)
1671 			break;
1672 
1673 		del_timer(&p->multicast_router_timer);
1674 
1675 		if (val == 0)
1676 			break;
1677 
1678 		br_multicast_add_router(br, p);
1679 		break;
1680 
1681 	default:
1682 		err = -EINVAL;
1683 		break;
1684 	}
1685 
1686 unlock:
1687 	spin_unlock(&br->multicast_lock);
1688 
1689 	return err;
1690 }
1691 
1692 int br_multicast_toggle(struct net_bridge *br, unsigned long val)
1693 {
1694 	struct net_bridge_port *port;
1695 	int err = 0;
1696 	struct net_bridge_mdb_htable *mdb;
1697 
1698 	spin_lock_bh(&br->multicast_lock);
1699 	if (br->multicast_disabled == !val)
1700 		goto unlock;
1701 
1702 	br->multicast_disabled = !val;
1703 	if (br->multicast_disabled)
1704 		goto unlock;
1705 
1706 	if (!netif_running(br->dev))
1707 		goto unlock;
1708 
1709 	mdb = mlock_dereference(br->mdb, br);
1710 	if (mdb) {
1711 		if (mdb->old) {
1712 			err = -EEXIST;
1713 rollback:
1714 			br->multicast_disabled = !!val;
1715 			goto unlock;
1716 		}
1717 
1718 		err = br_mdb_rehash(&br->mdb, mdb->max,
1719 				    br->hash_elasticity);
1720 		if (err)
1721 			goto rollback;
1722 	}
1723 
1724 	br_multicast_open(br);
1725 	list_for_each_entry(port, &br->port_list, list) {
1726 		if (port->state == BR_STATE_DISABLED ||
1727 		    port->state == BR_STATE_BLOCKING)
1728 			continue;
1729 
1730 		__br_multicast_enable_port(port);
1731 	}
1732 
1733 unlock:
1734 	spin_unlock_bh(&br->multicast_lock);
1735 
1736 	return err;
1737 }
1738 
1739 int br_multicast_set_hash_max(struct net_bridge *br, unsigned long val)
1740 {
1741 	int err = -ENOENT;
1742 	u32 old;
1743 	struct net_bridge_mdb_htable *mdb;
1744 
1745 	spin_lock(&br->multicast_lock);
1746 	if (!netif_running(br->dev))
1747 		goto unlock;
1748 
1749 	err = -EINVAL;
1750 	if (!is_power_of_2(val))
1751 		goto unlock;
1752 
1753 	mdb = mlock_dereference(br->mdb, br);
1754 	if (mdb && val < mdb->size)
1755 		goto unlock;
1756 
1757 	err = 0;
1758 
1759 	old = br->hash_max;
1760 	br->hash_max = val;
1761 
1762 	if (mdb) {
1763 		if (mdb->old) {
1764 			err = -EEXIST;
1765 rollback:
1766 			br->hash_max = old;
1767 			goto unlock;
1768 		}
1769 
1770 		err = br_mdb_rehash(&br->mdb, br->hash_max,
1771 				    br->hash_elasticity);
1772 		if (err)
1773 			goto rollback;
1774 	}
1775 
1776 unlock:
1777 	spin_unlock(&br->multicast_lock);
1778 
1779 	return err;
1780 }
1781