xref: /openbmc/linux/net/bridge/br_multicast.c (revision 9d749629)
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/ip6_checksum.h>
31 #endif
32 
33 #include "br_private.h"
34 
35 static void br_multicast_start_querier(struct net_bridge *br);
36 unsigned int br_mdb_rehash_seq;
37 
38 static inline int br_ip_equal(const struct br_ip *a, const struct br_ip *b)
39 {
40 	if (a->proto != b->proto)
41 		return 0;
42 	if (a->vid != b->vid)
43 		return 0;
44 	switch (a->proto) {
45 	case htons(ETH_P_IP):
46 		return a->u.ip4 == b->u.ip4;
47 #if IS_ENABLED(CONFIG_IPV6)
48 	case htons(ETH_P_IPV6):
49 		return ipv6_addr_equal(&a->u.ip6, &b->u.ip6);
50 #endif
51 	}
52 	return 0;
53 }
54 
55 static inline int __br_ip4_hash(struct net_bridge_mdb_htable *mdb, __be32 ip,
56 				__u16 vid)
57 {
58 	return jhash_2words((__force u32)ip, vid, mdb->secret) & (mdb->max - 1);
59 }
60 
61 #if IS_ENABLED(CONFIG_IPV6)
62 static inline int __br_ip6_hash(struct net_bridge_mdb_htable *mdb,
63 				const struct in6_addr *ip,
64 				__u16 vid)
65 {
66 	return jhash_2words(ipv6_addr_hash(ip), vid,
67 			    mdb->secret) & (mdb->max - 1);
68 }
69 #endif
70 
71 static inline int br_ip_hash(struct net_bridge_mdb_htable *mdb,
72 			     struct br_ip *ip)
73 {
74 	switch (ip->proto) {
75 	case htons(ETH_P_IP):
76 		return __br_ip4_hash(mdb, ip->u.ip4, ip->vid);
77 #if IS_ENABLED(CONFIG_IPV6)
78 	case htons(ETH_P_IPV6):
79 		return __br_ip6_hash(mdb, &ip->u.ip6, ip->vid);
80 #endif
81 	}
82 	return 0;
83 }
84 
85 static struct net_bridge_mdb_entry *__br_mdb_ip_get(
86 	struct net_bridge_mdb_htable *mdb, struct br_ip *dst, int hash)
87 {
88 	struct net_bridge_mdb_entry *mp;
89 	struct hlist_node *p;
90 
91 	hlist_for_each_entry_rcu(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) {
92 		if (br_ip_equal(&mp->addr, dst))
93 			return mp;
94 	}
95 
96 	return NULL;
97 }
98 
99 struct net_bridge_mdb_entry *br_mdb_ip_get(struct net_bridge_mdb_htable *mdb,
100 					   struct br_ip *dst)
101 {
102 	if (!mdb)
103 		return NULL;
104 
105 	return __br_mdb_ip_get(mdb, dst, br_ip_hash(mdb, dst));
106 }
107 
108 static struct net_bridge_mdb_entry *br_mdb_ip4_get(
109 	struct net_bridge_mdb_htable *mdb, __be32 dst, __u16 vid)
110 {
111 	struct br_ip br_dst;
112 
113 	br_dst.u.ip4 = dst;
114 	br_dst.proto = htons(ETH_P_IP);
115 	br_dst.vid = vid;
116 
117 	return br_mdb_ip_get(mdb, &br_dst);
118 }
119 
120 #if IS_ENABLED(CONFIG_IPV6)
121 static struct net_bridge_mdb_entry *br_mdb_ip6_get(
122 	struct net_bridge_mdb_htable *mdb, const struct in6_addr *dst,
123 	__u16 vid)
124 {
125 	struct br_ip br_dst;
126 
127 	br_dst.u.ip6 = *dst;
128 	br_dst.proto = htons(ETH_P_IPV6);
129 	br_dst.vid = vid;
130 
131 	return br_mdb_ip_get(mdb, &br_dst);
132 }
133 #endif
134 
135 struct net_bridge_mdb_entry *br_mdb_get(struct net_bridge *br,
136 					struct sk_buff *skb)
137 {
138 	struct net_bridge_mdb_htable *mdb = rcu_dereference(br->mdb);
139 	struct br_ip ip;
140 
141 	if (br->multicast_disabled)
142 		return NULL;
143 
144 	if (BR_INPUT_SKB_CB(skb)->igmp)
145 		return NULL;
146 
147 	ip.proto = skb->protocol;
148 
149 	switch (skb->protocol) {
150 	case htons(ETH_P_IP):
151 		ip.u.ip4 = ip_hdr(skb)->daddr;
152 		break;
153 #if IS_ENABLED(CONFIG_IPV6)
154 	case htons(ETH_P_IPV6):
155 		ip.u.ip6 = ipv6_hdr(skb)->daddr;
156 		break;
157 #endif
158 	default:
159 		return NULL;
160 	}
161 
162 	return br_mdb_ip_get(mdb, &ip);
163 }
164 
165 static void br_mdb_free(struct rcu_head *head)
166 {
167 	struct net_bridge_mdb_htable *mdb =
168 		container_of(head, struct net_bridge_mdb_htable, rcu);
169 	struct net_bridge_mdb_htable *old = mdb->old;
170 
171 	mdb->old = NULL;
172 	kfree(old->mhash);
173 	kfree(old);
174 }
175 
176 static int br_mdb_copy(struct net_bridge_mdb_htable *new,
177 		       struct net_bridge_mdb_htable *old,
178 		       int elasticity)
179 {
180 	struct net_bridge_mdb_entry *mp;
181 	struct hlist_node *p;
182 	int maxlen;
183 	int len;
184 	int i;
185 
186 	for (i = 0; i < old->max; i++)
187 		hlist_for_each_entry(mp, p, &old->mhash[i], hlist[old->ver])
188 			hlist_add_head(&mp->hlist[new->ver],
189 				       &new->mhash[br_ip_hash(new, &mp->addr)]);
190 
191 	if (!elasticity)
192 		return 0;
193 
194 	maxlen = 0;
195 	for (i = 0; i < new->max; i++) {
196 		len = 0;
197 		hlist_for_each_entry(mp, p, &new->mhash[i], hlist[new->ver])
198 			len++;
199 		if (len > maxlen)
200 			maxlen = len;
201 	}
202 
203 	return maxlen > elasticity ? -EINVAL : 0;
204 }
205 
206 void br_multicast_free_pg(struct rcu_head *head)
207 {
208 	struct net_bridge_port_group *p =
209 		container_of(head, struct net_bridge_port_group, rcu);
210 
211 	kfree(p);
212 }
213 
214 static void br_multicast_free_group(struct rcu_head *head)
215 {
216 	struct net_bridge_mdb_entry *mp =
217 		container_of(head, struct net_bridge_mdb_entry, rcu);
218 
219 	kfree(mp);
220 }
221 
222 static void br_multicast_group_expired(unsigned long data)
223 {
224 	struct net_bridge_mdb_entry *mp = (void *)data;
225 	struct net_bridge *br = mp->br;
226 	struct net_bridge_mdb_htable *mdb;
227 
228 	spin_lock(&br->multicast_lock);
229 	if (!netif_running(br->dev) || timer_pending(&mp->timer))
230 		goto out;
231 
232 	mp->mglist = false;
233 
234 	if (mp->ports)
235 		goto out;
236 
237 	mdb = mlock_dereference(br->mdb, br);
238 
239 	hlist_del_rcu(&mp->hlist[mdb->ver]);
240 	mdb->size--;
241 
242 	call_rcu_bh(&mp->rcu, br_multicast_free_group);
243 
244 out:
245 	spin_unlock(&br->multicast_lock);
246 }
247 
248 static void br_multicast_del_pg(struct net_bridge *br,
249 				struct net_bridge_port_group *pg)
250 {
251 	struct net_bridge_mdb_htable *mdb;
252 	struct net_bridge_mdb_entry *mp;
253 	struct net_bridge_port_group *p;
254 	struct net_bridge_port_group __rcu **pp;
255 
256 	mdb = mlock_dereference(br->mdb, br);
257 
258 	mp = br_mdb_ip_get(mdb, &pg->addr);
259 	if (WARN_ON(!mp))
260 		return;
261 
262 	for (pp = &mp->ports;
263 	     (p = mlock_dereference(*pp, br)) != NULL;
264 	     pp = &p->next) {
265 		if (p != pg)
266 			continue;
267 
268 		rcu_assign_pointer(*pp, p->next);
269 		hlist_del_init(&p->mglist);
270 		del_timer(&p->timer);
271 		call_rcu_bh(&p->rcu, br_multicast_free_pg);
272 
273 		if (!mp->ports && !mp->mglist &&
274 		    netif_running(br->dev))
275 			mod_timer(&mp->timer, jiffies);
276 
277 		return;
278 	}
279 
280 	WARN_ON(1);
281 }
282 
283 static void br_multicast_port_group_expired(unsigned long data)
284 {
285 	struct net_bridge_port_group *pg = (void *)data;
286 	struct net_bridge *br = pg->port->br;
287 
288 	spin_lock(&br->multicast_lock);
289 	if (!netif_running(br->dev) || timer_pending(&pg->timer) ||
290 	    hlist_unhashed(&pg->mglist) || pg->state & MDB_PERMANENT)
291 		goto out;
292 
293 	br_multicast_del_pg(br, pg);
294 
295 out:
296 	spin_unlock(&br->multicast_lock);
297 }
298 
299 static int br_mdb_rehash(struct net_bridge_mdb_htable __rcu **mdbp, int max,
300 			 int elasticity)
301 {
302 	struct net_bridge_mdb_htable *old = rcu_dereference_protected(*mdbp, 1);
303 	struct net_bridge_mdb_htable *mdb;
304 	int err;
305 
306 	mdb = kmalloc(sizeof(*mdb), GFP_ATOMIC);
307 	if (!mdb)
308 		return -ENOMEM;
309 
310 	mdb->max = max;
311 	mdb->old = old;
312 
313 	mdb->mhash = kzalloc(max * sizeof(*mdb->mhash), GFP_ATOMIC);
314 	if (!mdb->mhash) {
315 		kfree(mdb);
316 		return -ENOMEM;
317 	}
318 
319 	mdb->size = old ? old->size : 0;
320 	mdb->ver = old ? old->ver ^ 1 : 0;
321 
322 	if (!old || elasticity)
323 		get_random_bytes(&mdb->secret, sizeof(mdb->secret));
324 	else
325 		mdb->secret = old->secret;
326 
327 	if (!old)
328 		goto out;
329 
330 	err = br_mdb_copy(mdb, old, elasticity);
331 	if (err) {
332 		kfree(mdb->mhash);
333 		kfree(mdb);
334 		return err;
335 	}
336 
337 	br_mdb_rehash_seq++;
338 	call_rcu_bh(&mdb->rcu, br_mdb_free);
339 
340 out:
341 	rcu_assign_pointer(*mdbp, mdb);
342 
343 	return 0;
344 }
345 
346 static struct sk_buff *br_ip4_multicast_alloc_query(struct net_bridge *br,
347 						    __be32 group)
348 {
349 	struct sk_buff *skb;
350 	struct igmphdr *ih;
351 	struct ethhdr *eth;
352 	struct iphdr *iph;
353 
354 	skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*iph) +
355 						 sizeof(*ih) + 4);
356 	if (!skb)
357 		goto out;
358 
359 	skb->protocol = htons(ETH_P_IP);
360 
361 	skb_reset_mac_header(skb);
362 	eth = eth_hdr(skb);
363 
364 	memcpy(eth->h_source, br->dev->dev_addr, 6);
365 	eth->h_dest[0] = 1;
366 	eth->h_dest[1] = 0;
367 	eth->h_dest[2] = 0x5e;
368 	eth->h_dest[3] = 0;
369 	eth->h_dest[4] = 0;
370 	eth->h_dest[5] = 1;
371 	eth->h_proto = htons(ETH_P_IP);
372 	skb_put(skb, sizeof(*eth));
373 
374 	skb_set_network_header(skb, skb->len);
375 	iph = ip_hdr(skb);
376 
377 	iph->version = 4;
378 	iph->ihl = 6;
379 	iph->tos = 0xc0;
380 	iph->tot_len = htons(sizeof(*iph) + sizeof(*ih) + 4);
381 	iph->id = 0;
382 	iph->frag_off = htons(IP_DF);
383 	iph->ttl = 1;
384 	iph->protocol = IPPROTO_IGMP;
385 	iph->saddr = 0;
386 	iph->daddr = htonl(INADDR_ALLHOSTS_GROUP);
387 	((u8 *)&iph[1])[0] = IPOPT_RA;
388 	((u8 *)&iph[1])[1] = 4;
389 	((u8 *)&iph[1])[2] = 0;
390 	((u8 *)&iph[1])[3] = 0;
391 	ip_send_check(iph);
392 	skb_put(skb, 24);
393 
394 	skb_set_transport_header(skb, skb->len);
395 	ih = igmp_hdr(skb);
396 	ih->type = IGMP_HOST_MEMBERSHIP_QUERY;
397 	ih->code = (group ? br->multicast_last_member_interval :
398 			    br->multicast_query_response_interval) /
399 		   (HZ / IGMP_TIMER_SCALE);
400 	ih->group = group;
401 	ih->csum = 0;
402 	ih->csum = ip_compute_csum((void *)ih, sizeof(struct igmphdr));
403 	skb_put(skb, sizeof(*ih));
404 
405 	__skb_pull(skb, sizeof(*eth));
406 
407 out:
408 	return skb;
409 }
410 
411 #if IS_ENABLED(CONFIG_IPV6)
412 static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
413 						    const struct in6_addr *group)
414 {
415 	struct sk_buff *skb;
416 	struct ipv6hdr *ip6h;
417 	struct mld_msg *mldq;
418 	struct ethhdr *eth;
419 	u8 *hopopt;
420 	unsigned long interval;
421 
422 	skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*ip6h) +
423 						 8 + sizeof(*mldq));
424 	if (!skb)
425 		goto out;
426 
427 	skb->protocol = htons(ETH_P_IPV6);
428 
429 	/* Ethernet header */
430 	skb_reset_mac_header(skb);
431 	eth = eth_hdr(skb);
432 
433 	memcpy(eth->h_source, br->dev->dev_addr, 6);
434 	eth->h_proto = htons(ETH_P_IPV6);
435 	skb_put(skb, sizeof(*eth));
436 
437 	/* IPv6 header + HbH option */
438 	skb_set_network_header(skb, skb->len);
439 	ip6h = ipv6_hdr(skb);
440 
441 	*(__force __be32 *)ip6h = htonl(0x60000000);
442 	ip6h->payload_len = htons(8 + sizeof(*mldq));
443 	ip6h->nexthdr = IPPROTO_HOPOPTS;
444 	ip6h->hop_limit = 1;
445 	ipv6_addr_set(&ip6h->daddr, htonl(0xff020000), 0, 0, htonl(1));
446 	if (ipv6_dev_get_saddr(dev_net(br->dev), br->dev, &ip6h->daddr, 0,
447 			       &ip6h->saddr)) {
448 		kfree_skb(skb);
449 		return NULL;
450 	}
451 	ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
452 
453 	hopopt = (u8 *)(ip6h + 1);
454 	hopopt[0] = IPPROTO_ICMPV6;		/* next hdr */
455 	hopopt[1] = 0;				/* length of HbH */
456 	hopopt[2] = IPV6_TLV_ROUTERALERT;	/* Router Alert */
457 	hopopt[3] = 2;				/* Length of RA Option */
458 	hopopt[4] = 0;				/* Type = 0x0000 (MLD) */
459 	hopopt[5] = 0;
460 	hopopt[6] = IPV6_TLV_PAD1;		/* Pad1 */
461 	hopopt[7] = IPV6_TLV_PAD1;		/* Pad1 */
462 
463 	skb_put(skb, sizeof(*ip6h) + 8);
464 
465 	/* ICMPv6 */
466 	skb_set_transport_header(skb, skb->len);
467 	mldq = (struct mld_msg *) icmp6_hdr(skb);
468 
469 	interval = ipv6_addr_any(group) ? br->multicast_last_member_interval :
470 					  br->multicast_query_response_interval;
471 
472 	mldq->mld_type = ICMPV6_MGM_QUERY;
473 	mldq->mld_code = 0;
474 	mldq->mld_cksum = 0;
475 	mldq->mld_maxdelay = htons((u16)jiffies_to_msecs(interval));
476 	mldq->mld_reserved = 0;
477 	mldq->mld_mca = *group;
478 
479 	/* checksum */
480 	mldq->mld_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
481 					  sizeof(*mldq), IPPROTO_ICMPV6,
482 					  csum_partial(mldq,
483 						       sizeof(*mldq), 0));
484 	skb_put(skb, sizeof(*mldq));
485 
486 	__skb_pull(skb, sizeof(*eth));
487 
488 out:
489 	return skb;
490 }
491 #endif
492 
493 static struct sk_buff *br_multicast_alloc_query(struct net_bridge *br,
494 						struct br_ip *addr)
495 {
496 	switch (addr->proto) {
497 	case htons(ETH_P_IP):
498 		return br_ip4_multicast_alloc_query(br, addr->u.ip4);
499 #if IS_ENABLED(CONFIG_IPV6)
500 	case htons(ETH_P_IPV6):
501 		return br_ip6_multicast_alloc_query(br, &addr->u.ip6);
502 #endif
503 	}
504 	return NULL;
505 }
506 
507 static struct net_bridge_mdb_entry *br_multicast_get_group(
508 	struct net_bridge *br, struct net_bridge_port *port,
509 	struct br_ip *group, int hash)
510 {
511 	struct net_bridge_mdb_htable *mdb;
512 	struct net_bridge_mdb_entry *mp;
513 	struct hlist_node *p;
514 	unsigned int count = 0;
515 	unsigned int max;
516 	int elasticity;
517 	int err;
518 
519 	mdb = rcu_dereference_protected(br->mdb, 1);
520 	hlist_for_each_entry(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) {
521 		count++;
522 		if (unlikely(br_ip_equal(group, &mp->addr)))
523 			return mp;
524 	}
525 
526 	elasticity = 0;
527 	max = mdb->max;
528 
529 	if (unlikely(count > br->hash_elasticity && count)) {
530 		if (net_ratelimit())
531 			br_info(br, "Multicast hash table "
532 				"chain limit reached: %s\n",
533 				port ? port->dev->name : br->dev->name);
534 
535 		elasticity = br->hash_elasticity;
536 	}
537 
538 	if (mdb->size >= max) {
539 		max *= 2;
540 		if (unlikely(max > br->hash_max)) {
541 			br_warn(br, "Multicast hash table maximum of %d "
542 				"reached, disabling snooping: %s\n",
543 				br->hash_max,
544 				port ? port->dev->name : br->dev->name);
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 struct net_bridge_mdb_entry *br_multicast_new_group(struct net_bridge *br,
583 	struct net_bridge_port *port, struct br_ip *group)
584 {
585 	struct net_bridge_mdb_htable *mdb;
586 	struct net_bridge_mdb_entry *mp;
587 	int hash;
588 	int err;
589 
590 	mdb = rcu_dereference_protected(br->mdb, 1);
591 	if (!mdb) {
592 		err = br_mdb_rehash(&br->mdb, BR_HASH_SIZE, 0);
593 		if (err)
594 			return ERR_PTR(err);
595 		goto rehash;
596 	}
597 
598 	hash = br_ip_hash(mdb, group);
599 	mp = br_multicast_get_group(br, port, group, hash);
600 	switch (PTR_ERR(mp)) {
601 	case 0:
602 		break;
603 
604 	case -EAGAIN:
605 rehash:
606 		mdb = rcu_dereference_protected(br->mdb, 1);
607 		hash = br_ip_hash(mdb, group);
608 		break;
609 
610 	default:
611 		goto out;
612 	}
613 
614 	mp = kzalloc(sizeof(*mp), GFP_ATOMIC);
615 	if (unlikely(!mp))
616 		return ERR_PTR(-ENOMEM);
617 
618 	mp->br = br;
619 	mp->addr = *group;
620 	setup_timer(&mp->timer, br_multicast_group_expired,
621 		    (unsigned long)mp);
622 
623 	hlist_add_head_rcu(&mp->hlist[mdb->ver], &mdb->mhash[hash]);
624 	mdb->size++;
625 
626 out:
627 	return mp;
628 }
629 
630 struct net_bridge_port_group *br_multicast_new_port_group(
631 			struct net_bridge_port *port,
632 			struct br_ip *group,
633 			struct net_bridge_port_group __rcu *next,
634 			unsigned char state)
635 {
636 	struct net_bridge_port_group *p;
637 
638 	p = kzalloc(sizeof(*p), GFP_ATOMIC);
639 	if (unlikely(!p))
640 		return NULL;
641 
642 	p->addr = *group;
643 	p->port = port;
644 	p->state = state;
645 	rcu_assign_pointer(p->next, next);
646 	hlist_add_head(&p->mglist, &port->mglist);
647 	setup_timer(&p->timer, br_multicast_port_group_expired,
648 		    (unsigned long)p);
649 	return p;
650 }
651 
652 static int br_multicast_add_group(struct net_bridge *br,
653 				  struct net_bridge_port *port,
654 				  struct br_ip *group)
655 {
656 	struct net_bridge_mdb_entry *mp;
657 	struct net_bridge_port_group *p;
658 	struct net_bridge_port_group __rcu **pp;
659 	unsigned long now = jiffies;
660 	int err;
661 
662 	spin_lock(&br->multicast_lock);
663 	if (!netif_running(br->dev) ||
664 	    (port && port->state == BR_STATE_DISABLED))
665 		goto out;
666 
667 	mp = br_multicast_new_group(br, port, group);
668 	err = PTR_ERR(mp);
669 	if (IS_ERR(mp))
670 		goto err;
671 
672 	if (!port) {
673 		mp->mglist = true;
674 		mod_timer(&mp->timer, now + br->multicast_membership_interval);
675 		goto out;
676 	}
677 
678 	for (pp = &mp->ports;
679 	     (p = mlock_dereference(*pp, br)) != NULL;
680 	     pp = &p->next) {
681 		if (p->port == port)
682 			goto found;
683 		if ((unsigned long)p->port < (unsigned long)port)
684 			break;
685 	}
686 
687 	p = br_multicast_new_port_group(port, group, *pp, MDB_TEMPORARY);
688 	if (unlikely(!p))
689 		goto err;
690 	rcu_assign_pointer(*pp, p);
691 	br_mdb_notify(br->dev, port, group, RTM_NEWMDB);
692 
693 found:
694 	mod_timer(&p->timer, now + br->multicast_membership_interval);
695 out:
696 	err = 0;
697 
698 err:
699 	spin_unlock(&br->multicast_lock);
700 	return err;
701 }
702 
703 static int br_ip4_multicast_add_group(struct net_bridge *br,
704 				      struct net_bridge_port *port,
705 				      __be32 group,
706 				      __u16 vid)
707 {
708 	struct br_ip br_group;
709 
710 	if (ipv4_is_local_multicast(group))
711 		return 0;
712 
713 	br_group.u.ip4 = group;
714 	br_group.proto = htons(ETH_P_IP);
715 	br_group.vid = vid;
716 
717 	return br_multicast_add_group(br, port, &br_group);
718 }
719 
720 #if IS_ENABLED(CONFIG_IPV6)
721 static int br_ip6_multicast_add_group(struct net_bridge *br,
722 				      struct net_bridge_port *port,
723 				      const struct in6_addr *group,
724 				      __u16 vid)
725 {
726 	struct br_ip br_group;
727 
728 	if (!ipv6_is_transient_multicast(group))
729 		return 0;
730 
731 	br_group.u.ip6 = *group;
732 	br_group.proto = htons(ETH_P_IPV6);
733 	br_group.vid = vid;
734 
735 	return br_multicast_add_group(br, port, &br_group);
736 }
737 #endif
738 
739 static void br_multicast_router_expired(unsigned long data)
740 {
741 	struct net_bridge_port *port = (void *)data;
742 	struct net_bridge *br = port->br;
743 
744 	spin_lock(&br->multicast_lock);
745 	if (port->multicast_router != 1 ||
746 	    timer_pending(&port->multicast_router_timer) ||
747 	    hlist_unhashed(&port->rlist))
748 		goto out;
749 
750 	hlist_del_init_rcu(&port->rlist);
751 
752 out:
753 	spin_unlock(&br->multicast_lock);
754 }
755 
756 static void br_multicast_local_router_expired(unsigned long data)
757 {
758 }
759 
760 static void br_multicast_querier_expired(unsigned long data)
761 {
762 	struct net_bridge *br = (void *)data;
763 
764 	spin_lock(&br->multicast_lock);
765 	if (!netif_running(br->dev) || br->multicast_disabled)
766 		goto out;
767 
768 	br_multicast_start_querier(br);
769 
770 out:
771 	spin_unlock(&br->multicast_lock);
772 }
773 
774 static void __br_multicast_send_query(struct net_bridge *br,
775 				      struct net_bridge_port *port,
776 				      struct br_ip *ip)
777 {
778 	struct sk_buff *skb;
779 
780 	skb = br_multicast_alloc_query(br, ip);
781 	if (!skb)
782 		return;
783 
784 	if (port) {
785 		__skb_push(skb, sizeof(struct ethhdr));
786 		skb->dev = port->dev;
787 		NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
788 			dev_queue_xmit);
789 	} else
790 		netif_rx(skb);
791 }
792 
793 static void br_multicast_send_query(struct net_bridge *br,
794 				    struct net_bridge_port *port, u32 sent)
795 {
796 	unsigned long time;
797 	struct br_ip br_group;
798 
799 	if (!netif_running(br->dev) || br->multicast_disabled ||
800 	    !br->multicast_querier ||
801 	    timer_pending(&br->multicast_querier_timer))
802 		return;
803 
804 	memset(&br_group.u, 0, sizeof(br_group.u));
805 
806 	br_group.proto = htons(ETH_P_IP);
807 	__br_multicast_send_query(br, port, &br_group);
808 
809 #if IS_ENABLED(CONFIG_IPV6)
810 	br_group.proto = htons(ETH_P_IPV6);
811 	__br_multicast_send_query(br, port, &br_group);
812 #endif
813 
814 	time = jiffies;
815 	time += sent < br->multicast_startup_query_count ?
816 		br->multicast_startup_query_interval :
817 		br->multicast_query_interval;
818 	mod_timer(port ? &port->multicast_query_timer :
819 			 &br->multicast_query_timer, time);
820 }
821 
822 static void br_multicast_port_query_expired(unsigned long data)
823 {
824 	struct net_bridge_port *port = (void *)data;
825 	struct net_bridge *br = port->br;
826 
827 	spin_lock(&br->multicast_lock);
828 	if (port->state == BR_STATE_DISABLED ||
829 	    port->state == BR_STATE_BLOCKING)
830 		goto out;
831 
832 	if (port->multicast_startup_queries_sent <
833 	    br->multicast_startup_query_count)
834 		port->multicast_startup_queries_sent++;
835 
836 	br_multicast_send_query(port->br, port,
837 				port->multicast_startup_queries_sent);
838 
839 out:
840 	spin_unlock(&br->multicast_lock);
841 }
842 
843 void br_multicast_add_port(struct net_bridge_port *port)
844 {
845 	port->multicast_router = 1;
846 
847 	setup_timer(&port->multicast_router_timer, br_multicast_router_expired,
848 		    (unsigned long)port);
849 	setup_timer(&port->multicast_query_timer,
850 		    br_multicast_port_query_expired, (unsigned long)port);
851 }
852 
853 void br_multicast_del_port(struct net_bridge_port *port)
854 {
855 	del_timer_sync(&port->multicast_router_timer);
856 }
857 
858 static void __br_multicast_enable_port(struct net_bridge_port *port)
859 {
860 	port->multicast_startup_queries_sent = 0;
861 
862 	if (try_to_del_timer_sync(&port->multicast_query_timer) >= 0 ||
863 	    del_timer(&port->multicast_query_timer))
864 		mod_timer(&port->multicast_query_timer, jiffies);
865 }
866 
867 void br_multicast_enable_port(struct net_bridge_port *port)
868 {
869 	struct net_bridge *br = port->br;
870 
871 	spin_lock(&br->multicast_lock);
872 	if (br->multicast_disabled || !netif_running(br->dev))
873 		goto out;
874 
875 	__br_multicast_enable_port(port);
876 
877 out:
878 	spin_unlock(&br->multicast_lock);
879 }
880 
881 void br_multicast_disable_port(struct net_bridge_port *port)
882 {
883 	struct net_bridge *br = port->br;
884 	struct net_bridge_port_group *pg;
885 	struct hlist_node *p, *n;
886 
887 	spin_lock(&br->multicast_lock);
888 	hlist_for_each_entry_safe(pg, p, n, &port->mglist, mglist)
889 		br_multicast_del_pg(br, pg);
890 
891 	if (!hlist_unhashed(&port->rlist))
892 		hlist_del_init_rcu(&port->rlist);
893 	del_timer(&port->multicast_router_timer);
894 	del_timer(&port->multicast_query_timer);
895 	spin_unlock(&br->multicast_lock);
896 }
897 
898 static int br_ip4_multicast_igmp3_report(struct net_bridge *br,
899 					 struct net_bridge_port *port,
900 					 struct sk_buff *skb)
901 {
902 	struct igmpv3_report *ih;
903 	struct igmpv3_grec *grec;
904 	int i;
905 	int len;
906 	int num;
907 	int type;
908 	int err = 0;
909 	__be32 group;
910 	u16 vid = 0;
911 
912 	if (!pskb_may_pull(skb, sizeof(*ih)))
913 		return -EINVAL;
914 
915 	br_vlan_get_tag(skb, &vid);
916 	ih = igmpv3_report_hdr(skb);
917 	num = ntohs(ih->ngrec);
918 	len = sizeof(*ih);
919 
920 	for (i = 0; i < num; i++) {
921 		len += sizeof(*grec);
922 		if (!pskb_may_pull(skb, len))
923 			return -EINVAL;
924 
925 		grec = (void *)(skb->data + len - sizeof(*grec));
926 		group = grec->grec_mca;
927 		type = grec->grec_type;
928 
929 		len += ntohs(grec->grec_nsrcs) * 4;
930 		if (!pskb_may_pull(skb, len))
931 			return -EINVAL;
932 
933 		/* We treat this as an IGMPv2 report for now. */
934 		switch (type) {
935 		case IGMPV3_MODE_IS_INCLUDE:
936 		case IGMPV3_MODE_IS_EXCLUDE:
937 		case IGMPV3_CHANGE_TO_INCLUDE:
938 		case IGMPV3_CHANGE_TO_EXCLUDE:
939 		case IGMPV3_ALLOW_NEW_SOURCES:
940 		case IGMPV3_BLOCK_OLD_SOURCES:
941 			break;
942 
943 		default:
944 			continue;
945 		}
946 
947 		err = br_ip4_multicast_add_group(br, port, group, vid);
948 		if (err)
949 			break;
950 	}
951 
952 	return err;
953 }
954 
955 #if IS_ENABLED(CONFIG_IPV6)
956 static int br_ip6_multicast_mld2_report(struct net_bridge *br,
957 					struct net_bridge_port *port,
958 					struct sk_buff *skb)
959 {
960 	struct icmp6hdr *icmp6h;
961 	struct mld2_grec *grec;
962 	int i;
963 	int len;
964 	int num;
965 	int err = 0;
966 	u16 vid = 0;
967 
968 	if (!pskb_may_pull(skb, sizeof(*icmp6h)))
969 		return -EINVAL;
970 
971 	br_vlan_get_tag(skb, &vid);
972 	icmp6h = icmp6_hdr(skb);
973 	num = ntohs(icmp6h->icmp6_dataun.un_data16[1]);
974 	len = sizeof(*icmp6h);
975 
976 	for (i = 0; i < num; i++) {
977 		__be16 *nsrcs, _nsrcs;
978 
979 		nsrcs = skb_header_pointer(skb,
980 					   len + offsetof(struct mld2_grec,
981 							  grec_nsrcs),
982 					   sizeof(_nsrcs), &_nsrcs);
983 		if (!nsrcs)
984 			return -EINVAL;
985 
986 		if (!pskb_may_pull(skb,
987 				   len + sizeof(*grec) +
988 				   sizeof(struct in6_addr) * ntohs(*nsrcs)))
989 			return -EINVAL;
990 
991 		grec = (struct mld2_grec *)(skb->data + len);
992 		len += sizeof(*grec) +
993 		       sizeof(struct in6_addr) * ntohs(*nsrcs);
994 
995 		/* We treat these as MLDv1 reports for now. */
996 		switch (grec->grec_type) {
997 		case MLD2_MODE_IS_INCLUDE:
998 		case MLD2_MODE_IS_EXCLUDE:
999 		case MLD2_CHANGE_TO_INCLUDE:
1000 		case MLD2_CHANGE_TO_EXCLUDE:
1001 		case MLD2_ALLOW_NEW_SOURCES:
1002 		case MLD2_BLOCK_OLD_SOURCES:
1003 			break;
1004 
1005 		default:
1006 			continue;
1007 		}
1008 
1009 		err = br_ip6_multicast_add_group(br, port, &grec->grec_mca,
1010 						 vid);
1011 		if (!err)
1012 			break;
1013 	}
1014 
1015 	return err;
1016 }
1017 #endif
1018 
1019 /*
1020  * Add port to rotuer_list
1021  *  list is maintained ordered by pointer value
1022  *  and locked by br->multicast_lock and RCU
1023  */
1024 static void br_multicast_add_router(struct net_bridge *br,
1025 				    struct net_bridge_port *port)
1026 {
1027 	struct net_bridge_port *p;
1028 	struct hlist_node *n, *slot = NULL;
1029 
1030 	hlist_for_each_entry(p, n, &br->router_list, rlist) {
1031 		if ((unsigned long) port >= (unsigned long) p)
1032 			break;
1033 		slot = n;
1034 	}
1035 
1036 	if (slot)
1037 		hlist_add_after_rcu(slot, &port->rlist);
1038 	else
1039 		hlist_add_head_rcu(&port->rlist, &br->router_list);
1040 }
1041 
1042 static void br_multicast_mark_router(struct net_bridge *br,
1043 				     struct net_bridge_port *port)
1044 {
1045 	unsigned long now = jiffies;
1046 
1047 	if (!port) {
1048 		if (br->multicast_router == 1)
1049 			mod_timer(&br->multicast_router_timer,
1050 				  now + br->multicast_querier_interval);
1051 		return;
1052 	}
1053 
1054 	if (port->multicast_router != 1)
1055 		return;
1056 
1057 	if (!hlist_unhashed(&port->rlist))
1058 		goto timer;
1059 
1060 	br_multicast_add_router(br, port);
1061 
1062 timer:
1063 	mod_timer(&port->multicast_router_timer,
1064 		  now + br->multicast_querier_interval);
1065 }
1066 
1067 static void br_multicast_query_received(struct net_bridge *br,
1068 					struct net_bridge_port *port,
1069 					int saddr)
1070 {
1071 	if (saddr)
1072 		mod_timer(&br->multicast_querier_timer,
1073 			  jiffies + br->multicast_querier_interval);
1074 	else if (timer_pending(&br->multicast_querier_timer))
1075 		return;
1076 
1077 	br_multicast_mark_router(br, port);
1078 }
1079 
1080 static int br_ip4_multicast_query(struct net_bridge *br,
1081 				  struct net_bridge_port *port,
1082 				  struct sk_buff *skb)
1083 {
1084 	const struct iphdr *iph = ip_hdr(skb);
1085 	struct igmphdr *ih = igmp_hdr(skb);
1086 	struct net_bridge_mdb_entry *mp;
1087 	struct igmpv3_query *ih3;
1088 	struct net_bridge_port_group *p;
1089 	struct net_bridge_port_group __rcu **pp;
1090 	unsigned long max_delay;
1091 	unsigned long now = jiffies;
1092 	__be32 group;
1093 	int err = 0;
1094 	u16 vid = 0;
1095 
1096 	spin_lock(&br->multicast_lock);
1097 	if (!netif_running(br->dev) ||
1098 	    (port && port->state == BR_STATE_DISABLED))
1099 		goto out;
1100 
1101 	br_multicast_query_received(br, port, !!iph->saddr);
1102 
1103 	group = ih->group;
1104 
1105 	if (skb->len == sizeof(*ih)) {
1106 		max_delay = ih->code * (HZ / IGMP_TIMER_SCALE);
1107 
1108 		if (!max_delay) {
1109 			max_delay = 10 * HZ;
1110 			group = 0;
1111 		}
1112 	} else {
1113 		if (!pskb_may_pull(skb, sizeof(struct igmpv3_query))) {
1114 			err = -EINVAL;
1115 			goto out;
1116 		}
1117 
1118 		ih3 = igmpv3_query_hdr(skb);
1119 		if (ih3->nsrcs)
1120 			goto out;
1121 
1122 		max_delay = ih3->code ?
1123 			    IGMPV3_MRC(ih3->code) * (HZ / IGMP_TIMER_SCALE) : 1;
1124 	}
1125 
1126 	if (!group)
1127 		goto out;
1128 
1129 	br_vlan_get_tag(skb, &vid);
1130 	mp = br_mdb_ip4_get(mlock_dereference(br->mdb, br), group, vid);
1131 	if (!mp)
1132 		goto out;
1133 
1134 	max_delay *= br->multicast_last_member_count;
1135 
1136 	if (mp->mglist &&
1137 	    (timer_pending(&mp->timer) ?
1138 	     time_after(mp->timer.expires, now + max_delay) :
1139 	     try_to_del_timer_sync(&mp->timer) >= 0))
1140 		mod_timer(&mp->timer, now + max_delay);
1141 
1142 	for (pp = &mp->ports;
1143 	     (p = mlock_dereference(*pp, br)) != NULL;
1144 	     pp = &p->next) {
1145 		if (timer_pending(&p->timer) ?
1146 		    time_after(p->timer.expires, now + max_delay) :
1147 		    try_to_del_timer_sync(&p->timer) >= 0)
1148 			mod_timer(&p->timer, now + max_delay);
1149 	}
1150 
1151 out:
1152 	spin_unlock(&br->multicast_lock);
1153 	return err;
1154 }
1155 
1156 #if IS_ENABLED(CONFIG_IPV6)
1157 static int br_ip6_multicast_query(struct net_bridge *br,
1158 				  struct net_bridge_port *port,
1159 				  struct sk_buff *skb)
1160 {
1161 	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
1162 	struct mld_msg *mld;
1163 	struct net_bridge_mdb_entry *mp;
1164 	struct mld2_query *mld2q;
1165 	struct net_bridge_port_group *p;
1166 	struct net_bridge_port_group __rcu **pp;
1167 	unsigned long max_delay;
1168 	unsigned long now = jiffies;
1169 	const struct in6_addr *group = NULL;
1170 	int err = 0;
1171 	u16 vid = 0;
1172 
1173 	spin_lock(&br->multicast_lock);
1174 	if (!netif_running(br->dev) ||
1175 	    (port && port->state == BR_STATE_DISABLED))
1176 		goto out;
1177 
1178 	br_multicast_query_received(br, port, !ipv6_addr_any(&ip6h->saddr));
1179 
1180 	if (skb->len == sizeof(*mld)) {
1181 		if (!pskb_may_pull(skb, sizeof(*mld))) {
1182 			err = -EINVAL;
1183 			goto out;
1184 		}
1185 		mld = (struct mld_msg *) icmp6_hdr(skb);
1186 		max_delay = msecs_to_jiffies(ntohs(mld->mld_maxdelay));
1187 		if (max_delay)
1188 			group = &mld->mld_mca;
1189 	} else if (skb->len >= sizeof(*mld2q)) {
1190 		if (!pskb_may_pull(skb, sizeof(*mld2q))) {
1191 			err = -EINVAL;
1192 			goto out;
1193 		}
1194 		mld2q = (struct mld2_query *)icmp6_hdr(skb);
1195 		if (!mld2q->mld2q_nsrcs)
1196 			group = &mld2q->mld2q_mca;
1197 		max_delay = mld2q->mld2q_mrc ? MLDV2_MRC(ntohs(mld2q->mld2q_mrc)) : 1;
1198 	}
1199 
1200 	if (!group)
1201 		goto out;
1202 
1203 	br_vlan_get_tag(skb, &vid);
1204 	mp = br_mdb_ip6_get(mlock_dereference(br->mdb, br), group, vid);
1205 	if (!mp)
1206 		goto out;
1207 
1208 	max_delay *= br->multicast_last_member_count;
1209 	if (mp->mglist &&
1210 	    (timer_pending(&mp->timer) ?
1211 	     time_after(mp->timer.expires, now + max_delay) :
1212 	     try_to_del_timer_sync(&mp->timer) >= 0))
1213 		mod_timer(&mp->timer, now + max_delay);
1214 
1215 	for (pp = &mp->ports;
1216 	     (p = mlock_dereference(*pp, br)) != NULL;
1217 	     pp = &p->next) {
1218 		if (timer_pending(&p->timer) ?
1219 		    time_after(p->timer.expires, now + max_delay) :
1220 		    try_to_del_timer_sync(&p->timer) >= 0)
1221 			mod_timer(&p->timer, now + max_delay);
1222 	}
1223 
1224 out:
1225 	spin_unlock(&br->multicast_lock);
1226 	return err;
1227 }
1228 #endif
1229 
1230 static void br_multicast_leave_group(struct net_bridge *br,
1231 				     struct net_bridge_port *port,
1232 				     struct br_ip *group)
1233 {
1234 	struct net_bridge_mdb_htable *mdb;
1235 	struct net_bridge_mdb_entry *mp;
1236 	struct net_bridge_port_group *p;
1237 	unsigned long now;
1238 	unsigned long time;
1239 
1240 	spin_lock(&br->multicast_lock);
1241 	if (!netif_running(br->dev) ||
1242 	    (port && port->state == BR_STATE_DISABLED) ||
1243 	    timer_pending(&br->multicast_querier_timer))
1244 		goto out;
1245 
1246 	mdb = mlock_dereference(br->mdb, br);
1247 	mp = br_mdb_ip_get(mdb, group);
1248 	if (!mp)
1249 		goto out;
1250 
1251 	if (port && (port->flags & BR_MULTICAST_FAST_LEAVE)) {
1252 		struct net_bridge_port_group __rcu **pp;
1253 
1254 		for (pp = &mp->ports;
1255 		     (p = mlock_dereference(*pp, br)) != NULL;
1256 		     pp = &p->next) {
1257 			if (p->port != port)
1258 				continue;
1259 
1260 			rcu_assign_pointer(*pp, p->next);
1261 			hlist_del_init(&p->mglist);
1262 			del_timer(&p->timer);
1263 			call_rcu_bh(&p->rcu, br_multicast_free_pg);
1264 			br_mdb_notify(br->dev, port, group, RTM_DELMDB);
1265 
1266 			if (!mp->ports && !mp->mglist &&
1267 			    netif_running(br->dev))
1268 				mod_timer(&mp->timer, jiffies);
1269 		}
1270 		goto out;
1271 	}
1272 
1273 	now = jiffies;
1274 	time = now + br->multicast_last_member_count *
1275 		     br->multicast_last_member_interval;
1276 
1277 	if (!port) {
1278 		if (mp->mglist &&
1279 		    (timer_pending(&mp->timer) ?
1280 		     time_after(mp->timer.expires, time) :
1281 		     try_to_del_timer_sync(&mp->timer) >= 0)) {
1282 			mod_timer(&mp->timer, time);
1283 		}
1284 
1285 		goto out;
1286 	}
1287 
1288 	for (p = mlock_dereference(mp->ports, br);
1289 	     p != NULL;
1290 	     p = mlock_dereference(p->next, br)) {
1291 		if (p->port != port)
1292 			continue;
1293 
1294 		if (!hlist_unhashed(&p->mglist) &&
1295 		    (timer_pending(&p->timer) ?
1296 		     time_after(p->timer.expires, time) :
1297 		     try_to_del_timer_sync(&p->timer) >= 0)) {
1298 			mod_timer(&p->timer, time);
1299 		}
1300 
1301 		break;
1302 	}
1303 
1304 out:
1305 	spin_unlock(&br->multicast_lock);
1306 }
1307 
1308 static void br_ip4_multicast_leave_group(struct net_bridge *br,
1309 					 struct net_bridge_port *port,
1310 					 __be32 group,
1311 					 __u16 vid)
1312 {
1313 	struct br_ip br_group;
1314 
1315 	if (ipv4_is_local_multicast(group))
1316 		return;
1317 
1318 	br_group.u.ip4 = group;
1319 	br_group.proto = htons(ETH_P_IP);
1320 	br_group.vid = vid;
1321 
1322 	br_multicast_leave_group(br, port, &br_group);
1323 }
1324 
1325 #if IS_ENABLED(CONFIG_IPV6)
1326 static void br_ip6_multicast_leave_group(struct net_bridge *br,
1327 					 struct net_bridge_port *port,
1328 					 const struct in6_addr *group,
1329 					 __u16 vid)
1330 {
1331 	struct br_ip br_group;
1332 
1333 	if (!ipv6_is_transient_multicast(group))
1334 		return;
1335 
1336 	br_group.u.ip6 = *group;
1337 	br_group.proto = htons(ETH_P_IPV6);
1338 	br_group.vid = vid;
1339 
1340 	br_multicast_leave_group(br, port, &br_group);
1341 }
1342 #endif
1343 
1344 static int br_multicast_ipv4_rcv(struct net_bridge *br,
1345 				 struct net_bridge_port *port,
1346 				 struct sk_buff *skb)
1347 {
1348 	struct sk_buff *skb2 = skb;
1349 	const struct iphdr *iph;
1350 	struct igmphdr *ih;
1351 	unsigned int len;
1352 	unsigned int offset;
1353 	int err;
1354 	u16 vid = 0;
1355 
1356 	/* We treat OOM as packet loss for now. */
1357 	if (!pskb_may_pull(skb, sizeof(*iph)))
1358 		return -EINVAL;
1359 
1360 	iph = ip_hdr(skb);
1361 
1362 	if (iph->ihl < 5 || iph->version != 4)
1363 		return -EINVAL;
1364 
1365 	if (!pskb_may_pull(skb, ip_hdrlen(skb)))
1366 		return -EINVAL;
1367 
1368 	iph = ip_hdr(skb);
1369 
1370 	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1371 		return -EINVAL;
1372 
1373 	if (iph->protocol != IPPROTO_IGMP) {
1374 		if ((iph->daddr & IGMP_LOCAL_GROUP_MASK) != IGMP_LOCAL_GROUP)
1375 			BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
1376 		return 0;
1377 	}
1378 
1379 	len = ntohs(iph->tot_len);
1380 	if (skb->len < len || len < ip_hdrlen(skb))
1381 		return -EINVAL;
1382 
1383 	if (skb->len > len) {
1384 		skb2 = skb_clone(skb, GFP_ATOMIC);
1385 		if (!skb2)
1386 			return -ENOMEM;
1387 
1388 		err = pskb_trim_rcsum(skb2, len);
1389 		if (err)
1390 			goto err_out;
1391 	}
1392 
1393 	len -= ip_hdrlen(skb2);
1394 	offset = skb_network_offset(skb2) + ip_hdrlen(skb2);
1395 	__skb_pull(skb2, offset);
1396 	skb_reset_transport_header(skb2);
1397 
1398 	err = -EINVAL;
1399 	if (!pskb_may_pull(skb2, sizeof(*ih)))
1400 		goto out;
1401 
1402 	switch (skb2->ip_summed) {
1403 	case CHECKSUM_COMPLETE:
1404 		if (!csum_fold(skb2->csum))
1405 			break;
1406 		/* fall through */
1407 	case CHECKSUM_NONE:
1408 		skb2->csum = 0;
1409 		if (skb_checksum_complete(skb2))
1410 			goto out;
1411 	}
1412 
1413 	err = 0;
1414 
1415 	br_vlan_get_tag(skb2, &vid);
1416 	BR_INPUT_SKB_CB(skb)->igmp = 1;
1417 	ih = igmp_hdr(skb2);
1418 
1419 	switch (ih->type) {
1420 	case IGMP_HOST_MEMBERSHIP_REPORT:
1421 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
1422 		BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
1423 		err = br_ip4_multicast_add_group(br, port, ih->group, vid);
1424 		break;
1425 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
1426 		err = br_ip4_multicast_igmp3_report(br, port, skb2);
1427 		break;
1428 	case IGMP_HOST_MEMBERSHIP_QUERY:
1429 		err = br_ip4_multicast_query(br, port, skb2);
1430 		break;
1431 	case IGMP_HOST_LEAVE_MESSAGE:
1432 		br_ip4_multicast_leave_group(br, port, ih->group, vid);
1433 		break;
1434 	}
1435 
1436 out:
1437 	__skb_push(skb2, offset);
1438 err_out:
1439 	if (skb2 != skb)
1440 		kfree_skb(skb2);
1441 	return err;
1442 }
1443 
1444 #if IS_ENABLED(CONFIG_IPV6)
1445 static int br_multicast_ipv6_rcv(struct net_bridge *br,
1446 				 struct net_bridge_port *port,
1447 				 struct sk_buff *skb)
1448 {
1449 	struct sk_buff *skb2;
1450 	const struct ipv6hdr *ip6h;
1451 	u8 icmp6_type;
1452 	u8 nexthdr;
1453 	__be16 frag_off;
1454 	unsigned int len;
1455 	int offset;
1456 	int err;
1457 	u16 vid = 0;
1458 
1459 	if (!pskb_may_pull(skb, sizeof(*ip6h)))
1460 		return -EINVAL;
1461 
1462 	ip6h = ipv6_hdr(skb);
1463 
1464 	/*
1465 	 * We're interested in MLD messages only.
1466 	 *  - Version is 6
1467 	 *  - MLD has always Router Alert hop-by-hop option
1468 	 *  - But we do not support jumbrograms.
1469 	 */
1470 	if (ip6h->version != 6 ||
1471 	    ip6h->nexthdr != IPPROTO_HOPOPTS ||
1472 	    ip6h->payload_len == 0)
1473 		return 0;
1474 
1475 	len = ntohs(ip6h->payload_len) + sizeof(*ip6h);
1476 	if (skb->len < len)
1477 		return -EINVAL;
1478 
1479 	nexthdr = ip6h->nexthdr;
1480 	offset = ipv6_skip_exthdr(skb, sizeof(*ip6h), &nexthdr, &frag_off);
1481 
1482 	if (offset < 0 || nexthdr != IPPROTO_ICMPV6)
1483 		return 0;
1484 
1485 	/* Okay, we found ICMPv6 header */
1486 	skb2 = skb_clone(skb, GFP_ATOMIC);
1487 	if (!skb2)
1488 		return -ENOMEM;
1489 
1490 	err = -EINVAL;
1491 	if (!pskb_may_pull(skb2, offset + sizeof(struct icmp6hdr)))
1492 		goto out;
1493 
1494 	len -= offset - skb_network_offset(skb2);
1495 
1496 	__skb_pull(skb2, offset);
1497 	skb_reset_transport_header(skb2);
1498 	skb_postpull_rcsum(skb2, skb_network_header(skb2),
1499 			   skb_network_header_len(skb2));
1500 
1501 	icmp6_type = icmp6_hdr(skb2)->icmp6_type;
1502 
1503 	switch (icmp6_type) {
1504 	case ICMPV6_MGM_QUERY:
1505 	case ICMPV6_MGM_REPORT:
1506 	case ICMPV6_MGM_REDUCTION:
1507 	case ICMPV6_MLD2_REPORT:
1508 		break;
1509 	default:
1510 		err = 0;
1511 		goto out;
1512 	}
1513 
1514 	/* Okay, we found MLD message. Check further. */
1515 	if (skb2->len > len) {
1516 		err = pskb_trim_rcsum(skb2, len);
1517 		if (err)
1518 			goto out;
1519 		err = -EINVAL;
1520 	}
1521 
1522 	ip6h = ipv6_hdr(skb2);
1523 
1524 	switch (skb2->ip_summed) {
1525 	case CHECKSUM_COMPLETE:
1526 		if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, skb2->len,
1527 					IPPROTO_ICMPV6, skb2->csum))
1528 			break;
1529 		/*FALLTHROUGH*/
1530 	case CHECKSUM_NONE:
1531 		skb2->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr,
1532 							&ip6h->daddr,
1533 							skb2->len,
1534 							IPPROTO_ICMPV6, 0));
1535 		if (__skb_checksum_complete(skb2))
1536 			goto out;
1537 	}
1538 
1539 	err = 0;
1540 
1541 	br_vlan_get_tag(skb, &vid);
1542 	BR_INPUT_SKB_CB(skb)->igmp = 1;
1543 
1544 	switch (icmp6_type) {
1545 	case ICMPV6_MGM_REPORT:
1546 	    {
1547 		struct mld_msg *mld;
1548 		if (!pskb_may_pull(skb2, sizeof(*mld))) {
1549 			err = -EINVAL;
1550 			goto out;
1551 		}
1552 		mld = (struct mld_msg *)skb_transport_header(skb2);
1553 		BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
1554 		err = br_ip6_multicast_add_group(br, port, &mld->mld_mca, vid);
1555 		break;
1556 	    }
1557 	case ICMPV6_MLD2_REPORT:
1558 		err = br_ip6_multicast_mld2_report(br, port, skb2);
1559 		break;
1560 	case ICMPV6_MGM_QUERY:
1561 		err = br_ip6_multicast_query(br, port, skb2);
1562 		break;
1563 	case ICMPV6_MGM_REDUCTION:
1564 	    {
1565 		struct mld_msg *mld;
1566 		if (!pskb_may_pull(skb2, sizeof(*mld))) {
1567 			err = -EINVAL;
1568 			goto out;
1569 		}
1570 		mld = (struct mld_msg *)skb_transport_header(skb2);
1571 		br_ip6_multicast_leave_group(br, port, &mld->mld_mca, vid);
1572 	    }
1573 	}
1574 
1575 out:
1576 	kfree_skb(skb2);
1577 	return err;
1578 }
1579 #endif
1580 
1581 int br_multicast_rcv(struct net_bridge *br, struct net_bridge_port *port,
1582 		     struct sk_buff *skb)
1583 {
1584 	BR_INPUT_SKB_CB(skb)->igmp = 0;
1585 	BR_INPUT_SKB_CB(skb)->mrouters_only = 0;
1586 
1587 	if (br->multicast_disabled)
1588 		return 0;
1589 
1590 	switch (skb->protocol) {
1591 	case htons(ETH_P_IP):
1592 		return br_multicast_ipv4_rcv(br, port, skb);
1593 #if IS_ENABLED(CONFIG_IPV6)
1594 	case htons(ETH_P_IPV6):
1595 		return br_multicast_ipv6_rcv(br, port, skb);
1596 #endif
1597 	}
1598 
1599 	return 0;
1600 }
1601 
1602 static void br_multicast_query_expired(unsigned long data)
1603 {
1604 	struct net_bridge *br = (void *)data;
1605 
1606 	spin_lock(&br->multicast_lock);
1607 	if (br->multicast_startup_queries_sent <
1608 	    br->multicast_startup_query_count)
1609 		br->multicast_startup_queries_sent++;
1610 
1611 	br_multicast_send_query(br, NULL, br->multicast_startup_queries_sent);
1612 
1613 	spin_unlock(&br->multicast_lock);
1614 }
1615 
1616 void br_multicast_init(struct net_bridge *br)
1617 {
1618 	br->hash_elasticity = 4;
1619 	br->hash_max = 512;
1620 
1621 	br->multicast_router = 1;
1622 	br->multicast_querier = 0;
1623 	br->multicast_last_member_count = 2;
1624 	br->multicast_startup_query_count = 2;
1625 
1626 	br->multicast_last_member_interval = HZ;
1627 	br->multicast_query_response_interval = 10 * HZ;
1628 	br->multicast_startup_query_interval = 125 * HZ / 4;
1629 	br->multicast_query_interval = 125 * HZ;
1630 	br->multicast_querier_interval = 255 * HZ;
1631 	br->multicast_membership_interval = 260 * HZ;
1632 
1633 	spin_lock_init(&br->multicast_lock);
1634 	setup_timer(&br->multicast_router_timer,
1635 		    br_multicast_local_router_expired, 0);
1636 	setup_timer(&br->multicast_querier_timer,
1637 		    br_multicast_querier_expired, (unsigned long)br);
1638 	setup_timer(&br->multicast_query_timer, br_multicast_query_expired,
1639 		    (unsigned long)br);
1640 }
1641 
1642 void br_multicast_open(struct net_bridge *br)
1643 {
1644 	br->multicast_startup_queries_sent = 0;
1645 
1646 	if (br->multicast_disabled)
1647 		return;
1648 
1649 	mod_timer(&br->multicast_query_timer, jiffies);
1650 }
1651 
1652 void br_multicast_stop(struct net_bridge *br)
1653 {
1654 	struct net_bridge_mdb_htable *mdb;
1655 	struct net_bridge_mdb_entry *mp;
1656 	struct hlist_node *p, *n;
1657 	u32 ver;
1658 	int i;
1659 
1660 	del_timer_sync(&br->multicast_router_timer);
1661 	del_timer_sync(&br->multicast_querier_timer);
1662 	del_timer_sync(&br->multicast_query_timer);
1663 
1664 	spin_lock_bh(&br->multicast_lock);
1665 	mdb = mlock_dereference(br->mdb, br);
1666 	if (!mdb)
1667 		goto out;
1668 
1669 	br->mdb = NULL;
1670 
1671 	ver = mdb->ver;
1672 	for (i = 0; i < mdb->max; i++) {
1673 		hlist_for_each_entry_safe(mp, p, n, &mdb->mhash[i],
1674 					  hlist[ver]) {
1675 			del_timer(&mp->timer);
1676 			call_rcu_bh(&mp->rcu, br_multicast_free_group);
1677 		}
1678 	}
1679 
1680 	if (mdb->old) {
1681 		spin_unlock_bh(&br->multicast_lock);
1682 		rcu_barrier_bh();
1683 		spin_lock_bh(&br->multicast_lock);
1684 		WARN_ON(mdb->old);
1685 	}
1686 
1687 	mdb->old = mdb;
1688 	call_rcu_bh(&mdb->rcu, br_mdb_free);
1689 
1690 out:
1691 	spin_unlock_bh(&br->multicast_lock);
1692 }
1693 
1694 int br_multicast_set_router(struct net_bridge *br, unsigned long val)
1695 {
1696 	int err = -ENOENT;
1697 
1698 	spin_lock_bh(&br->multicast_lock);
1699 	if (!netif_running(br->dev))
1700 		goto unlock;
1701 
1702 	switch (val) {
1703 	case 0:
1704 	case 2:
1705 		del_timer(&br->multicast_router_timer);
1706 		/* fall through */
1707 	case 1:
1708 		br->multicast_router = val;
1709 		err = 0;
1710 		break;
1711 
1712 	default:
1713 		err = -EINVAL;
1714 		break;
1715 	}
1716 
1717 unlock:
1718 	spin_unlock_bh(&br->multicast_lock);
1719 
1720 	return err;
1721 }
1722 
1723 int br_multicast_set_port_router(struct net_bridge_port *p, unsigned long val)
1724 {
1725 	struct net_bridge *br = p->br;
1726 	int err = -ENOENT;
1727 
1728 	spin_lock(&br->multicast_lock);
1729 	if (!netif_running(br->dev) || p->state == BR_STATE_DISABLED)
1730 		goto unlock;
1731 
1732 	switch (val) {
1733 	case 0:
1734 	case 1:
1735 	case 2:
1736 		p->multicast_router = val;
1737 		err = 0;
1738 
1739 		if (val < 2 && !hlist_unhashed(&p->rlist))
1740 			hlist_del_init_rcu(&p->rlist);
1741 
1742 		if (val == 1)
1743 			break;
1744 
1745 		del_timer(&p->multicast_router_timer);
1746 
1747 		if (val == 0)
1748 			break;
1749 
1750 		br_multicast_add_router(br, p);
1751 		break;
1752 
1753 	default:
1754 		err = -EINVAL;
1755 		break;
1756 	}
1757 
1758 unlock:
1759 	spin_unlock(&br->multicast_lock);
1760 
1761 	return err;
1762 }
1763 
1764 static void br_multicast_start_querier(struct net_bridge *br)
1765 {
1766 	struct net_bridge_port *port;
1767 
1768 	br_multicast_open(br);
1769 
1770 	list_for_each_entry(port, &br->port_list, list) {
1771 		if (port->state == BR_STATE_DISABLED ||
1772 		    port->state == BR_STATE_BLOCKING)
1773 			continue;
1774 
1775 		__br_multicast_enable_port(port);
1776 	}
1777 }
1778 
1779 int br_multicast_toggle(struct net_bridge *br, unsigned long val)
1780 {
1781 	int err = 0;
1782 	struct net_bridge_mdb_htable *mdb;
1783 
1784 	spin_lock_bh(&br->multicast_lock);
1785 	if (br->multicast_disabled == !val)
1786 		goto unlock;
1787 
1788 	br->multicast_disabled = !val;
1789 	if (br->multicast_disabled)
1790 		goto unlock;
1791 
1792 	if (!netif_running(br->dev))
1793 		goto unlock;
1794 
1795 	mdb = mlock_dereference(br->mdb, br);
1796 	if (mdb) {
1797 		if (mdb->old) {
1798 			err = -EEXIST;
1799 rollback:
1800 			br->multicast_disabled = !!val;
1801 			goto unlock;
1802 		}
1803 
1804 		err = br_mdb_rehash(&br->mdb, mdb->max,
1805 				    br->hash_elasticity);
1806 		if (err)
1807 			goto rollback;
1808 	}
1809 
1810 	br_multicast_start_querier(br);
1811 
1812 unlock:
1813 	spin_unlock_bh(&br->multicast_lock);
1814 
1815 	return err;
1816 }
1817 
1818 int br_multicast_set_querier(struct net_bridge *br, unsigned long val)
1819 {
1820 	val = !!val;
1821 
1822 	spin_lock_bh(&br->multicast_lock);
1823 	if (br->multicast_querier == val)
1824 		goto unlock;
1825 
1826 	br->multicast_querier = val;
1827 	if (val)
1828 		br_multicast_start_querier(br);
1829 
1830 unlock:
1831 	spin_unlock_bh(&br->multicast_lock);
1832 
1833 	return 0;
1834 }
1835 
1836 int br_multicast_set_hash_max(struct net_bridge *br, unsigned long val)
1837 {
1838 	int err = -ENOENT;
1839 	u32 old;
1840 	struct net_bridge_mdb_htable *mdb;
1841 
1842 	spin_lock(&br->multicast_lock);
1843 	if (!netif_running(br->dev))
1844 		goto unlock;
1845 
1846 	err = -EINVAL;
1847 	if (!is_power_of_2(val))
1848 		goto unlock;
1849 
1850 	mdb = mlock_dereference(br->mdb, br);
1851 	if (mdb && val < mdb->size)
1852 		goto unlock;
1853 
1854 	err = 0;
1855 
1856 	old = br->hash_max;
1857 	br->hash_max = val;
1858 
1859 	if (mdb) {
1860 		if (mdb->old) {
1861 			err = -EEXIST;
1862 rollback:
1863 			br->hash_max = old;
1864 			goto unlock;
1865 		}
1866 
1867 		err = br_mdb_rehash(&br->mdb, br->hash_max,
1868 				    br->hash_elasticity);
1869 		if (err)
1870 			goto rollback;
1871 	}
1872 
1873 unlock:
1874 	spin_unlock(&br->multicast_lock);
1875 
1876 	return err;
1877 }
1878