xref: /linux/net/bridge/br_multicast.c (revision 26b0d14106954ae46d2f4f7eec3481828a210f7d)
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 static void br_multicast_start_querier(struct net_bridge *br);
40 
41 #if IS_ENABLED(CONFIG_IPV6)
42 static inline int ipv6_is_transient_multicast(const struct in6_addr *addr)
43 {
44 	if (ipv6_addr_is_multicast(addr) && IPV6_ADDR_MC_FLAG_TRANSIENT(addr))
45 		return 1;
46 	return 0;
47 }
48 #endif
49 
50 static inline int br_ip_equal(const struct br_ip *a, const struct br_ip *b)
51 {
52 	if (a->proto != b->proto)
53 		return 0;
54 	switch (a->proto) {
55 	case htons(ETH_P_IP):
56 		return a->u.ip4 == b->u.ip4;
57 #if IS_ENABLED(CONFIG_IPV6)
58 	case htons(ETH_P_IPV6):
59 		return ipv6_addr_equal(&a->u.ip6, &b->u.ip6);
60 #endif
61 	}
62 	return 0;
63 }
64 
65 static inline int __br_ip4_hash(struct net_bridge_mdb_htable *mdb, __be32 ip)
66 {
67 	return jhash_1word(mdb->secret, (__force u32)ip) & (mdb->max - 1);
68 }
69 
70 #if IS_ENABLED(CONFIG_IPV6)
71 static inline int __br_ip6_hash(struct net_bridge_mdb_htable *mdb,
72 				const struct in6_addr *ip)
73 {
74 	return jhash2((__force u32 *)ip->s6_addr32, 4, mdb->secret) & (mdb->max - 1);
75 }
76 #endif
77 
78 static inline int br_ip_hash(struct net_bridge_mdb_htable *mdb,
79 			     struct br_ip *ip)
80 {
81 	switch (ip->proto) {
82 	case htons(ETH_P_IP):
83 		return __br_ip4_hash(mdb, ip->u.ip4);
84 #if IS_ENABLED(CONFIG_IPV6)
85 	case htons(ETH_P_IPV6):
86 		return __br_ip6_hash(mdb, &ip->u.ip6);
87 #endif
88 	}
89 	return 0;
90 }
91 
92 static struct net_bridge_mdb_entry *__br_mdb_ip_get(
93 	struct net_bridge_mdb_htable *mdb, struct br_ip *dst, int hash)
94 {
95 	struct net_bridge_mdb_entry *mp;
96 	struct hlist_node *p;
97 
98 	hlist_for_each_entry_rcu(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) {
99 		if (br_ip_equal(&mp->addr, dst))
100 			return mp;
101 	}
102 
103 	return NULL;
104 }
105 
106 static struct net_bridge_mdb_entry *br_mdb_ip_get(
107 	struct net_bridge_mdb_htable *mdb, struct br_ip *dst)
108 {
109 	if (!mdb)
110 		return NULL;
111 
112 	return __br_mdb_ip_get(mdb, dst, br_ip_hash(mdb, dst));
113 }
114 
115 static struct net_bridge_mdb_entry *br_mdb_ip4_get(
116 	struct net_bridge_mdb_htable *mdb, __be32 dst)
117 {
118 	struct br_ip br_dst;
119 
120 	br_dst.u.ip4 = dst;
121 	br_dst.proto = htons(ETH_P_IP);
122 
123 	return br_mdb_ip_get(mdb, &br_dst);
124 }
125 
126 #if IS_ENABLED(CONFIG_IPV6)
127 static struct net_bridge_mdb_entry *br_mdb_ip6_get(
128 	struct net_bridge_mdb_htable *mdb, const struct in6_addr *dst)
129 {
130 	struct br_ip br_dst;
131 
132 	br_dst.u.ip6 = *dst;
133 	br_dst.proto = htons(ETH_P_IPV6);
134 
135 	return br_mdb_ip_get(mdb, &br_dst);
136 }
137 #endif
138 
139 struct net_bridge_mdb_entry *br_mdb_get(struct net_bridge *br,
140 					struct sk_buff *skb)
141 {
142 	struct net_bridge_mdb_htable *mdb = rcu_dereference(br->mdb);
143 	struct br_ip ip;
144 
145 	if (br->multicast_disabled)
146 		return NULL;
147 
148 	if (BR_INPUT_SKB_CB(skb)->igmp)
149 		return NULL;
150 
151 	ip.proto = skb->protocol;
152 
153 	switch (skb->protocol) {
154 	case htons(ETH_P_IP):
155 		ip.u.ip4 = ip_hdr(skb)->daddr;
156 		break;
157 #if IS_ENABLED(CONFIG_IPV6)
158 	case htons(ETH_P_IPV6):
159 		ip.u.ip6 = ipv6_hdr(skb)->daddr;
160 		break;
161 #endif
162 	default:
163 		return NULL;
164 	}
165 
166 	return br_mdb_ip_get(mdb, &ip);
167 }
168 
169 static void br_mdb_free(struct rcu_head *head)
170 {
171 	struct net_bridge_mdb_htable *mdb =
172 		container_of(head, struct net_bridge_mdb_htable, rcu);
173 	struct net_bridge_mdb_htable *old = mdb->old;
174 
175 	mdb->old = NULL;
176 	kfree(old->mhash);
177 	kfree(old);
178 }
179 
180 static int br_mdb_copy(struct net_bridge_mdb_htable *new,
181 		       struct net_bridge_mdb_htable *old,
182 		       int elasticity)
183 {
184 	struct net_bridge_mdb_entry *mp;
185 	struct hlist_node *p;
186 	int maxlen;
187 	int len;
188 	int i;
189 
190 	for (i = 0; i < old->max; i++)
191 		hlist_for_each_entry(mp, p, &old->mhash[i], hlist[old->ver])
192 			hlist_add_head(&mp->hlist[new->ver],
193 				       &new->mhash[br_ip_hash(new, &mp->addr)]);
194 
195 	if (!elasticity)
196 		return 0;
197 
198 	maxlen = 0;
199 	for (i = 0; i < new->max; i++) {
200 		len = 0;
201 		hlist_for_each_entry(mp, p, &new->mhash[i], hlist[new->ver])
202 			len++;
203 		if (len > maxlen)
204 			maxlen = len;
205 	}
206 
207 	return maxlen > elasticity ? -EINVAL : 0;
208 }
209 
210 static void br_multicast_free_pg(struct rcu_head *head)
211 {
212 	struct net_bridge_port_group *p =
213 		container_of(head, struct net_bridge_port_group, rcu);
214 
215 	kfree(p);
216 }
217 
218 static void br_multicast_free_group(struct rcu_head *head)
219 {
220 	struct net_bridge_mdb_entry *mp =
221 		container_of(head, struct net_bridge_mdb_entry, rcu);
222 
223 	kfree(mp);
224 }
225 
226 static void br_multicast_group_expired(unsigned long data)
227 {
228 	struct net_bridge_mdb_entry *mp = (void *)data;
229 	struct net_bridge *br = mp->br;
230 	struct net_bridge_mdb_htable *mdb;
231 
232 	spin_lock(&br->multicast_lock);
233 	if (!netif_running(br->dev) || timer_pending(&mp->timer))
234 		goto out;
235 
236 	mp->mglist = false;
237 
238 	if (mp->ports)
239 		goto out;
240 
241 	mdb = mlock_dereference(br->mdb, br);
242 
243 	hlist_del_rcu(&mp->hlist[mdb->ver]);
244 	mdb->size--;
245 
246 	call_rcu_bh(&mp->rcu, br_multicast_free_group);
247 
248 out:
249 	spin_unlock(&br->multicast_lock);
250 }
251 
252 static void br_multicast_del_pg(struct net_bridge *br,
253 				struct net_bridge_port_group *pg)
254 {
255 	struct net_bridge_mdb_htable *mdb;
256 	struct net_bridge_mdb_entry *mp;
257 	struct net_bridge_port_group *p;
258 	struct net_bridge_port_group __rcu **pp;
259 
260 	mdb = mlock_dereference(br->mdb, br);
261 
262 	mp = br_mdb_ip_get(mdb, &pg->addr);
263 	if (WARN_ON(!mp))
264 		return;
265 
266 	for (pp = &mp->ports;
267 	     (p = mlock_dereference(*pp, br)) != NULL;
268 	     pp = &p->next) {
269 		if (p != pg)
270 			continue;
271 
272 		rcu_assign_pointer(*pp, p->next);
273 		hlist_del_init(&p->mglist);
274 		del_timer(&p->timer);
275 		call_rcu_bh(&p->rcu, br_multicast_free_pg);
276 
277 		if (!mp->ports && !mp->mglist &&
278 		    netif_running(br->dev))
279 			mod_timer(&mp->timer, jiffies);
280 
281 		return;
282 	}
283 
284 	WARN_ON(1);
285 }
286 
287 static void br_multicast_port_group_expired(unsigned long data)
288 {
289 	struct net_bridge_port_group *pg = (void *)data;
290 	struct net_bridge *br = pg->port->br;
291 
292 	spin_lock(&br->multicast_lock);
293 	if (!netif_running(br->dev) || timer_pending(&pg->timer) ||
294 	    hlist_unhashed(&pg->mglist))
295 		goto out;
296 
297 	br_multicast_del_pg(br, pg);
298 
299 out:
300 	spin_unlock(&br->multicast_lock);
301 }
302 
303 static int br_mdb_rehash(struct net_bridge_mdb_htable __rcu **mdbp, int max,
304 			 int elasticity)
305 {
306 	struct net_bridge_mdb_htable *old = rcu_dereference_protected(*mdbp, 1);
307 	struct net_bridge_mdb_htable *mdb;
308 	int err;
309 
310 	mdb = kmalloc(sizeof(*mdb), GFP_ATOMIC);
311 	if (!mdb)
312 		return -ENOMEM;
313 
314 	mdb->max = max;
315 	mdb->old = old;
316 
317 	mdb->mhash = kzalloc(max * sizeof(*mdb->mhash), GFP_ATOMIC);
318 	if (!mdb->mhash) {
319 		kfree(mdb);
320 		return -ENOMEM;
321 	}
322 
323 	mdb->size = old ? old->size : 0;
324 	mdb->ver = old ? old->ver ^ 1 : 0;
325 
326 	if (!old || elasticity)
327 		get_random_bytes(&mdb->secret, sizeof(mdb->secret));
328 	else
329 		mdb->secret = old->secret;
330 
331 	if (!old)
332 		goto out;
333 
334 	err = br_mdb_copy(mdb, old, elasticity);
335 	if (err) {
336 		kfree(mdb->mhash);
337 		kfree(mdb);
338 		return err;
339 	}
340 
341 	call_rcu_bh(&mdb->rcu, br_mdb_free);
342 
343 out:
344 	rcu_assign_pointer(*mdbp, mdb);
345 
346 	return 0;
347 }
348 
349 static struct sk_buff *br_ip4_multicast_alloc_query(struct net_bridge *br,
350 						    __be32 group)
351 {
352 	struct sk_buff *skb;
353 	struct igmphdr *ih;
354 	struct ethhdr *eth;
355 	struct iphdr *iph;
356 
357 	skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*iph) +
358 						 sizeof(*ih) + 4);
359 	if (!skb)
360 		goto out;
361 
362 	skb->protocol = htons(ETH_P_IP);
363 
364 	skb_reset_mac_header(skb);
365 	eth = eth_hdr(skb);
366 
367 	memcpy(eth->h_source, br->dev->dev_addr, 6);
368 	eth->h_dest[0] = 1;
369 	eth->h_dest[1] = 0;
370 	eth->h_dest[2] = 0x5e;
371 	eth->h_dest[3] = 0;
372 	eth->h_dest[4] = 0;
373 	eth->h_dest[5] = 1;
374 	eth->h_proto = htons(ETH_P_IP);
375 	skb_put(skb, sizeof(*eth));
376 
377 	skb_set_network_header(skb, skb->len);
378 	iph = ip_hdr(skb);
379 
380 	iph->version = 4;
381 	iph->ihl = 6;
382 	iph->tos = 0xc0;
383 	iph->tot_len = htons(sizeof(*iph) + sizeof(*ih) + 4);
384 	iph->id = 0;
385 	iph->frag_off = htons(IP_DF);
386 	iph->ttl = 1;
387 	iph->protocol = IPPROTO_IGMP;
388 	iph->saddr = 0;
389 	iph->daddr = htonl(INADDR_ALLHOSTS_GROUP);
390 	((u8 *)&iph[1])[0] = IPOPT_RA;
391 	((u8 *)&iph[1])[1] = 4;
392 	((u8 *)&iph[1])[2] = 0;
393 	((u8 *)&iph[1])[3] = 0;
394 	ip_send_check(iph);
395 	skb_put(skb, 24);
396 
397 	skb_set_transport_header(skb, skb->len);
398 	ih = igmp_hdr(skb);
399 	ih->type = IGMP_HOST_MEMBERSHIP_QUERY;
400 	ih->code = (group ? br->multicast_last_member_interval :
401 			    br->multicast_query_response_interval) /
402 		   (HZ / IGMP_TIMER_SCALE);
403 	ih->group = group;
404 	ih->csum = 0;
405 	ih->csum = ip_compute_csum((void *)ih, sizeof(struct igmphdr));
406 	skb_put(skb, sizeof(*ih));
407 
408 	__skb_pull(skb, sizeof(*eth));
409 
410 out:
411 	return skb;
412 }
413 
414 #if IS_ENABLED(CONFIG_IPV6)
415 static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
416 						    const struct in6_addr *group)
417 {
418 	struct sk_buff *skb;
419 	struct ipv6hdr *ip6h;
420 	struct mld_msg *mldq;
421 	struct ethhdr *eth;
422 	u8 *hopopt;
423 	unsigned long interval;
424 
425 	skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*ip6h) +
426 						 8 + sizeof(*mldq));
427 	if (!skb)
428 		goto out;
429 
430 	skb->protocol = htons(ETH_P_IPV6);
431 
432 	/* Ethernet header */
433 	skb_reset_mac_header(skb);
434 	eth = eth_hdr(skb);
435 
436 	memcpy(eth->h_source, br->dev->dev_addr, 6);
437 	eth->h_proto = htons(ETH_P_IPV6);
438 	skb_put(skb, sizeof(*eth));
439 
440 	/* IPv6 header + HbH option */
441 	skb_set_network_header(skb, skb->len);
442 	ip6h = ipv6_hdr(skb);
443 
444 	*(__force __be32 *)ip6h = htonl(0x60000000);
445 	ip6h->payload_len = htons(8 + sizeof(*mldq));
446 	ip6h->nexthdr = IPPROTO_HOPOPTS;
447 	ip6h->hop_limit = 1;
448 	ipv6_addr_set(&ip6h->daddr, htonl(0xff020000), 0, 0, htonl(1));
449 	if (ipv6_dev_get_saddr(dev_net(br->dev), br->dev, &ip6h->daddr, 0,
450 			       &ip6h->saddr)) {
451 		kfree_skb(skb);
452 		return NULL;
453 	}
454 	ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
455 
456 	hopopt = (u8 *)(ip6h + 1);
457 	hopopt[0] = IPPROTO_ICMPV6;		/* next hdr */
458 	hopopt[1] = 0;				/* length of HbH */
459 	hopopt[2] = IPV6_TLV_ROUTERALERT;	/* Router Alert */
460 	hopopt[3] = 2;				/* Length of RA Option */
461 	hopopt[4] = 0;				/* Type = 0x0000 (MLD) */
462 	hopopt[5] = 0;
463 	hopopt[6] = IPV6_TLV_PAD1;		/* Pad1 */
464 	hopopt[7] = IPV6_TLV_PAD1;		/* Pad1 */
465 
466 	skb_put(skb, sizeof(*ip6h) + 8);
467 
468 	/* ICMPv6 */
469 	skb_set_transport_header(skb, skb->len);
470 	mldq = (struct mld_msg *) icmp6_hdr(skb);
471 
472 	interval = ipv6_addr_any(group) ? br->multicast_last_member_interval :
473 					  br->multicast_query_response_interval;
474 
475 	mldq->mld_type = ICMPV6_MGM_QUERY;
476 	mldq->mld_code = 0;
477 	mldq->mld_cksum = 0;
478 	mldq->mld_maxdelay = htons((u16)jiffies_to_msecs(interval));
479 	mldq->mld_reserved = 0;
480 	mldq->mld_mca = *group;
481 
482 	/* checksum */
483 	mldq->mld_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
484 					  sizeof(*mldq), IPPROTO_ICMPV6,
485 					  csum_partial(mldq,
486 						       sizeof(*mldq), 0));
487 	skb_put(skb, sizeof(*mldq));
488 
489 	__skb_pull(skb, sizeof(*eth));
490 
491 out:
492 	return skb;
493 }
494 #endif
495 
496 static struct sk_buff *br_multicast_alloc_query(struct net_bridge *br,
497 						struct br_ip *addr)
498 {
499 	switch (addr->proto) {
500 	case htons(ETH_P_IP):
501 		return br_ip4_multicast_alloc_query(br, addr->u.ip4);
502 #if IS_ENABLED(CONFIG_IPV6)
503 	case htons(ETH_P_IPV6):
504 		return br_ip6_multicast_alloc_query(br, &addr->u.ip6);
505 #endif
506 	}
507 	return NULL;
508 }
509 
510 static struct net_bridge_mdb_entry *br_multicast_get_group(
511 	struct net_bridge *br, struct net_bridge_port *port,
512 	struct br_ip *group, int hash)
513 {
514 	struct net_bridge_mdb_htable *mdb;
515 	struct net_bridge_mdb_entry *mp;
516 	struct hlist_node *p;
517 	unsigned int count = 0;
518 	unsigned int max;
519 	int elasticity;
520 	int err;
521 
522 	mdb = rcu_dereference_protected(br->mdb, 1);
523 	hlist_for_each_entry(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) {
524 		count++;
525 		if (unlikely(br_ip_equal(group, &mp->addr)))
526 			return mp;
527 	}
528 
529 	elasticity = 0;
530 	max = mdb->max;
531 
532 	if (unlikely(count > br->hash_elasticity && count)) {
533 		if (net_ratelimit())
534 			br_info(br, "Multicast hash table "
535 				"chain limit reached: %s\n",
536 				port ? port->dev->name : br->dev->name);
537 
538 		elasticity = br->hash_elasticity;
539 	}
540 
541 	if (mdb->size >= max) {
542 		max *= 2;
543 		if (unlikely(max >= br->hash_max)) {
544 			br_warn(br, "Multicast hash table maximum "
545 				"reached, disabling snooping: %s, %d\n",
546 				port ? port->dev->name : br->dev->name, max);
547 			err = -E2BIG;
548 disable:
549 			br->multicast_disabled = 1;
550 			goto err;
551 		}
552 	}
553 
554 	if (max > mdb->max || elasticity) {
555 		if (mdb->old) {
556 			if (net_ratelimit())
557 				br_info(br, "Multicast hash table "
558 					"on fire: %s\n",
559 					port ? port->dev->name : br->dev->name);
560 			err = -EEXIST;
561 			goto err;
562 		}
563 
564 		err = br_mdb_rehash(&br->mdb, max, elasticity);
565 		if (err) {
566 			br_warn(br, "Cannot rehash multicast "
567 				"hash table, disabling snooping: %s, %d, %d\n",
568 				port ? port->dev->name : br->dev->name,
569 				mdb->size, err);
570 			goto disable;
571 		}
572 
573 		err = -EAGAIN;
574 		goto err;
575 	}
576 
577 	return NULL;
578 
579 err:
580 	mp = ERR_PTR(err);
581 	return mp;
582 }
583 
584 static struct net_bridge_mdb_entry *br_multicast_new_group(
585 	struct net_bridge *br, struct net_bridge_port *port,
586 	struct br_ip *group)
587 {
588 	struct net_bridge_mdb_htable *mdb;
589 	struct net_bridge_mdb_entry *mp;
590 	int hash;
591 	int err;
592 
593 	mdb = rcu_dereference_protected(br->mdb, 1);
594 	if (!mdb) {
595 		err = br_mdb_rehash(&br->mdb, BR_HASH_SIZE, 0);
596 		if (err)
597 			return ERR_PTR(err);
598 		goto rehash;
599 	}
600 
601 	hash = br_ip_hash(mdb, group);
602 	mp = br_multicast_get_group(br, port, group, hash);
603 	switch (PTR_ERR(mp)) {
604 	case 0:
605 		break;
606 
607 	case -EAGAIN:
608 rehash:
609 		mdb = rcu_dereference_protected(br->mdb, 1);
610 		hash = br_ip_hash(mdb, group);
611 		break;
612 
613 	default:
614 		goto out;
615 	}
616 
617 	mp = kzalloc(sizeof(*mp), GFP_ATOMIC);
618 	if (unlikely(!mp))
619 		return ERR_PTR(-ENOMEM);
620 
621 	mp->br = br;
622 	mp->addr = *group;
623 	setup_timer(&mp->timer, br_multicast_group_expired,
624 		    (unsigned long)mp);
625 
626 	hlist_add_head_rcu(&mp->hlist[mdb->ver], &mdb->mhash[hash]);
627 	mdb->size++;
628 
629 out:
630 	return mp;
631 }
632 
633 static int br_multicast_add_group(struct net_bridge *br,
634 				  struct net_bridge_port *port,
635 				  struct br_ip *group)
636 {
637 	struct net_bridge_mdb_entry *mp;
638 	struct net_bridge_port_group *p;
639 	struct net_bridge_port_group __rcu **pp;
640 	unsigned long now = jiffies;
641 	int err;
642 
643 	spin_lock(&br->multicast_lock);
644 	if (!netif_running(br->dev) ||
645 	    (port && port->state == BR_STATE_DISABLED))
646 		goto out;
647 
648 	mp = br_multicast_new_group(br, port, group);
649 	err = PTR_ERR(mp);
650 	if (IS_ERR(mp))
651 		goto err;
652 
653 	if (!port) {
654 		mp->mglist = true;
655 		mod_timer(&mp->timer, now + br->multicast_membership_interval);
656 		goto out;
657 	}
658 
659 	for (pp = &mp->ports;
660 	     (p = mlock_dereference(*pp, br)) != NULL;
661 	     pp = &p->next) {
662 		if (p->port == port)
663 			goto found;
664 		if ((unsigned long)p->port < (unsigned long)port)
665 			break;
666 	}
667 
668 	p = kzalloc(sizeof(*p), GFP_ATOMIC);
669 	err = -ENOMEM;
670 	if (unlikely(!p))
671 		goto err;
672 
673 	p->addr = *group;
674 	p->port = port;
675 	p->next = *pp;
676 	hlist_add_head(&p->mglist, &port->mglist);
677 	setup_timer(&p->timer, br_multicast_port_group_expired,
678 		    (unsigned long)p);
679 
680 	rcu_assign_pointer(*pp, p);
681 
682 found:
683 	mod_timer(&p->timer, now + br->multicast_membership_interval);
684 out:
685 	err = 0;
686 
687 err:
688 	spin_unlock(&br->multicast_lock);
689 	return err;
690 }
691 
692 static int br_ip4_multicast_add_group(struct net_bridge *br,
693 				      struct net_bridge_port *port,
694 				      __be32 group)
695 {
696 	struct br_ip br_group;
697 
698 	if (ipv4_is_local_multicast(group))
699 		return 0;
700 
701 	br_group.u.ip4 = group;
702 	br_group.proto = htons(ETH_P_IP);
703 
704 	return br_multicast_add_group(br, port, &br_group);
705 }
706 
707 #if IS_ENABLED(CONFIG_IPV6)
708 static int br_ip6_multicast_add_group(struct net_bridge *br,
709 				      struct net_bridge_port *port,
710 				      const struct in6_addr *group)
711 {
712 	struct br_ip br_group;
713 
714 	if (!ipv6_is_transient_multicast(group))
715 		return 0;
716 
717 	br_group.u.ip6 = *group;
718 	br_group.proto = htons(ETH_P_IPV6);
719 
720 	return br_multicast_add_group(br, port, &br_group);
721 }
722 #endif
723 
724 static void br_multicast_router_expired(unsigned long data)
725 {
726 	struct net_bridge_port *port = (void *)data;
727 	struct net_bridge *br = port->br;
728 
729 	spin_lock(&br->multicast_lock);
730 	if (port->multicast_router != 1 ||
731 	    timer_pending(&port->multicast_router_timer) ||
732 	    hlist_unhashed(&port->rlist))
733 		goto out;
734 
735 	hlist_del_init_rcu(&port->rlist);
736 
737 out:
738 	spin_unlock(&br->multicast_lock);
739 }
740 
741 static void br_multicast_local_router_expired(unsigned long data)
742 {
743 }
744 
745 static void br_multicast_querier_expired(unsigned long data)
746 {
747 	struct net_bridge *br = (void *)data;
748 
749 	spin_lock(&br->multicast_lock);
750 	if (!netif_running(br->dev) || br->multicast_disabled)
751 		goto out;
752 
753 	br_multicast_start_querier(br);
754 
755 out:
756 	spin_unlock(&br->multicast_lock);
757 }
758 
759 static void __br_multicast_send_query(struct net_bridge *br,
760 				      struct net_bridge_port *port,
761 				      struct br_ip *ip)
762 {
763 	struct sk_buff *skb;
764 
765 	skb = br_multicast_alloc_query(br, ip);
766 	if (!skb)
767 		return;
768 
769 	if (port) {
770 		__skb_push(skb, sizeof(struct ethhdr));
771 		skb->dev = port->dev;
772 		NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
773 			dev_queue_xmit);
774 	} else
775 		netif_rx(skb);
776 }
777 
778 static void br_multicast_send_query(struct net_bridge *br,
779 				    struct net_bridge_port *port, u32 sent)
780 {
781 	unsigned long time;
782 	struct br_ip br_group;
783 
784 	if (!netif_running(br->dev) || br->multicast_disabled ||
785 	    !br->multicast_querier ||
786 	    timer_pending(&br->multicast_querier_timer))
787 		return;
788 
789 	memset(&br_group.u, 0, sizeof(br_group.u));
790 
791 	br_group.proto = htons(ETH_P_IP);
792 	__br_multicast_send_query(br, port, &br_group);
793 
794 #if IS_ENABLED(CONFIG_IPV6)
795 	br_group.proto = htons(ETH_P_IPV6);
796 	__br_multicast_send_query(br, port, &br_group);
797 #endif
798 
799 	time = jiffies;
800 	time += sent < br->multicast_startup_query_count ?
801 		br->multicast_startup_query_interval :
802 		br->multicast_query_interval;
803 	mod_timer(port ? &port->multicast_query_timer :
804 			 &br->multicast_query_timer, time);
805 }
806 
807 static void br_multicast_port_query_expired(unsigned long data)
808 {
809 	struct net_bridge_port *port = (void *)data;
810 	struct net_bridge *br = port->br;
811 
812 	spin_lock(&br->multicast_lock);
813 	if (port->state == BR_STATE_DISABLED ||
814 	    port->state == BR_STATE_BLOCKING)
815 		goto out;
816 
817 	if (port->multicast_startup_queries_sent <
818 	    br->multicast_startup_query_count)
819 		port->multicast_startup_queries_sent++;
820 
821 	br_multicast_send_query(port->br, port,
822 				port->multicast_startup_queries_sent);
823 
824 out:
825 	spin_unlock(&br->multicast_lock);
826 }
827 
828 void br_multicast_add_port(struct net_bridge_port *port)
829 {
830 	port->multicast_router = 1;
831 
832 	setup_timer(&port->multicast_router_timer, br_multicast_router_expired,
833 		    (unsigned long)port);
834 	setup_timer(&port->multicast_query_timer,
835 		    br_multicast_port_query_expired, (unsigned long)port);
836 }
837 
838 void br_multicast_del_port(struct net_bridge_port *port)
839 {
840 	del_timer_sync(&port->multicast_router_timer);
841 }
842 
843 static void __br_multicast_enable_port(struct net_bridge_port *port)
844 {
845 	port->multicast_startup_queries_sent = 0;
846 
847 	if (try_to_del_timer_sync(&port->multicast_query_timer) >= 0 ||
848 	    del_timer(&port->multicast_query_timer))
849 		mod_timer(&port->multicast_query_timer, jiffies);
850 }
851 
852 void br_multicast_enable_port(struct net_bridge_port *port)
853 {
854 	struct net_bridge *br = port->br;
855 
856 	spin_lock(&br->multicast_lock);
857 	if (br->multicast_disabled || !netif_running(br->dev))
858 		goto out;
859 
860 	__br_multicast_enable_port(port);
861 
862 out:
863 	spin_unlock(&br->multicast_lock);
864 }
865 
866 void br_multicast_disable_port(struct net_bridge_port *port)
867 {
868 	struct net_bridge *br = port->br;
869 	struct net_bridge_port_group *pg;
870 	struct hlist_node *p, *n;
871 
872 	spin_lock(&br->multicast_lock);
873 	hlist_for_each_entry_safe(pg, p, n, &port->mglist, mglist)
874 		br_multicast_del_pg(br, pg);
875 
876 	if (!hlist_unhashed(&port->rlist))
877 		hlist_del_init_rcu(&port->rlist);
878 	del_timer(&port->multicast_router_timer);
879 	del_timer(&port->multicast_query_timer);
880 	spin_unlock(&br->multicast_lock);
881 }
882 
883 static int br_ip4_multicast_igmp3_report(struct net_bridge *br,
884 					 struct net_bridge_port *port,
885 					 struct sk_buff *skb)
886 {
887 	struct igmpv3_report *ih;
888 	struct igmpv3_grec *grec;
889 	int i;
890 	int len;
891 	int num;
892 	int type;
893 	int err = 0;
894 	__be32 group;
895 
896 	if (!pskb_may_pull(skb, sizeof(*ih)))
897 		return -EINVAL;
898 
899 	ih = igmpv3_report_hdr(skb);
900 	num = ntohs(ih->ngrec);
901 	len = sizeof(*ih);
902 
903 	for (i = 0; i < num; i++) {
904 		len += sizeof(*grec);
905 		if (!pskb_may_pull(skb, len))
906 			return -EINVAL;
907 
908 		grec = (void *)(skb->data + len - sizeof(*grec));
909 		group = grec->grec_mca;
910 		type = grec->grec_type;
911 
912 		len += ntohs(grec->grec_nsrcs) * 4;
913 		if (!pskb_may_pull(skb, len))
914 			return -EINVAL;
915 
916 		/* We treat this as an IGMPv2 report for now. */
917 		switch (type) {
918 		case IGMPV3_MODE_IS_INCLUDE:
919 		case IGMPV3_MODE_IS_EXCLUDE:
920 		case IGMPV3_CHANGE_TO_INCLUDE:
921 		case IGMPV3_CHANGE_TO_EXCLUDE:
922 		case IGMPV3_ALLOW_NEW_SOURCES:
923 		case IGMPV3_BLOCK_OLD_SOURCES:
924 			break;
925 
926 		default:
927 			continue;
928 		}
929 
930 		err = br_ip4_multicast_add_group(br, port, group);
931 		if (err)
932 			break;
933 	}
934 
935 	return err;
936 }
937 
938 #if IS_ENABLED(CONFIG_IPV6)
939 static int br_ip6_multicast_mld2_report(struct net_bridge *br,
940 					struct net_bridge_port *port,
941 					struct sk_buff *skb)
942 {
943 	struct icmp6hdr *icmp6h;
944 	struct mld2_grec *grec;
945 	int i;
946 	int len;
947 	int num;
948 	int err = 0;
949 
950 	if (!pskb_may_pull(skb, sizeof(*icmp6h)))
951 		return -EINVAL;
952 
953 	icmp6h = icmp6_hdr(skb);
954 	num = ntohs(icmp6h->icmp6_dataun.un_data16[1]);
955 	len = sizeof(*icmp6h);
956 
957 	for (i = 0; i < num; i++) {
958 		__be16 *nsrcs, _nsrcs;
959 
960 		nsrcs = skb_header_pointer(skb,
961 					   len + offsetof(struct mld2_grec,
962 							  grec_nsrcs),
963 					   sizeof(_nsrcs), &_nsrcs);
964 		if (!nsrcs)
965 			return -EINVAL;
966 
967 		if (!pskb_may_pull(skb,
968 				   len + sizeof(*grec) +
969 				   sizeof(struct in6_addr) * ntohs(*nsrcs)))
970 			return -EINVAL;
971 
972 		grec = (struct mld2_grec *)(skb->data + len);
973 		len += sizeof(*grec) +
974 		       sizeof(struct in6_addr) * ntohs(*nsrcs);
975 
976 		/* We treat these as MLDv1 reports for now. */
977 		switch (grec->grec_type) {
978 		case MLD2_MODE_IS_INCLUDE:
979 		case MLD2_MODE_IS_EXCLUDE:
980 		case MLD2_CHANGE_TO_INCLUDE:
981 		case MLD2_CHANGE_TO_EXCLUDE:
982 		case MLD2_ALLOW_NEW_SOURCES:
983 		case MLD2_BLOCK_OLD_SOURCES:
984 			break;
985 
986 		default:
987 			continue;
988 		}
989 
990 		err = br_ip6_multicast_add_group(br, port, &grec->grec_mca);
991 		if (!err)
992 			break;
993 	}
994 
995 	return err;
996 }
997 #endif
998 
999 /*
1000  * Add port to rotuer_list
1001  *  list is maintained ordered by pointer value
1002  *  and locked by br->multicast_lock and RCU
1003  */
1004 static void br_multicast_add_router(struct net_bridge *br,
1005 				    struct net_bridge_port *port)
1006 {
1007 	struct net_bridge_port *p;
1008 	struct hlist_node *n, *slot = NULL;
1009 
1010 	hlist_for_each_entry(p, n, &br->router_list, rlist) {
1011 		if ((unsigned long) port >= (unsigned long) p)
1012 			break;
1013 		slot = n;
1014 	}
1015 
1016 	if (slot)
1017 		hlist_add_after_rcu(slot, &port->rlist);
1018 	else
1019 		hlist_add_head_rcu(&port->rlist, &br->router_list);
1020 }
1021 
1022 static void br_multicast_mark_router(struct net_bridge *br,
1023 				     struct net_bridge_port *port)
1024 {
1025 	unsigned long now = jiffies;
1026 
1027 	if (!port) {
1028 		if (br->multicast_router == 1)
1029 			mod_timer(&br->multicast_router_timer,
1030 				  now + br->multicast_querier_interval);
1031 		return;
1032 	}
1033 
1034 	if (port->multicast_router != 1)
1035 		return;
1036 
1037 	if (!hlist_unhashed(&port->rlist))
1038 		goto timer;
1039 
1040 	br_multicast_add_router(br, port);
1041 
1042 timer:
1043 	mod_timer(&port->multicast_router_timer,
1044 		  now + br->multicast_querier_interval);
1045 }
1046 
1047 static void br_multicast_query_received(struct net_bridge *br,
1048 					struct net_bridge_port *port,
1049 					int saddr)
1050 {
1051 	if (saddr)
1052 		mod_timer(&br->multicast_querier_timer,
1053 			  jiffies + br->multicast_querier_interval);
1054 	else if (timer_pending(&br->multicast_querier_timer))
1055 		return;
1056 
1057 	br_multicast_mark_router(br, port);
1058 }
1059 
1060 static int br_ip4_multicast_query(struct net_bridge *br,
1061 				  struct net_bridge_port *port,
1062 				  struct sk_buff *skb)
1063 {
1064 	const struct iphdr *iph = ip_hdr(skb);
1065 	struct igmphdr *ih = igmp_hdr(skb);
1066 	struct net_bridge_mdb_entry *mp;
1067 	struct igmpv3_query *ih3;
1068 	struct net_bridge_port_group *p;
1069 	struct net_bridge_port_group __rcu **pp;
1070 	unsigned long max_delay;
1071 	unsigned long now = jiffies;
1072 	__be32 group;
1073 	int err = 0;
1074 
1075 	spin_lock(&br->multicast_lock);
1076 	if (!netif_running(br->dev) ||
1077 	    (port && port->state == BR_STATE_DISABLED))
1078 		goto out;
1079 
1080 	br_multicast_query_received(br, port, !!iph->saddr);
1081 
1082 	group = ih->group;
1083 
1084 	if (skb->len == sizeof(*ih)) {
1085 		max_delay = ih->code * (HZ / IGMP_TIMER_SCALE);
1086 
1087 		if (!max_delay) {
1088 			max_delay = 10 * HZ;
1089 			group = 0;
1090 		}
1091 	} else {
1092 		if (!pskb_may_pull(skb, sizeof(struct igmpv3_query))) {
1093 			err = -EINVAL;
1094 			goto out;
1095 		}
1096 
1097 		ih3 = igmpv3_query_hdr(skb);
1098 		if (ih3->nsrcs)
1099 			goto out;
1100 
1101 		max_delay = ih3->code ?
1102 			    IGMPV3_MRC(ih3->code) * (HZ / IGMP_TIMER_SCALE) : 1;
1103 	}
1104 
1105 	if (!group)
1106 		goto out;
1107 
1108 	mp = br_mdb_ip4_get(mlock_dereference(br->mdb, br), group);
1109 	if (!mp)
1110 		goto out;
1111 
1112 	max_delay *= br->multicast_last_member_count;
1113 
1114 	if (mp->mglist &&
1115 	    (timer_pending(&mp->timer) ?
1116 	     time_after(mp->timer.expires, now + max_delay) :
1117 	     try_to_del_timer_sync(&mp->timer) >= 0))
1118 		mod_timer(&mp->timer, now + max_delay);
1119 
1120 	for (pp = &mp->ports;
1121 	     (p = mlock_dereference(*pp, br)) != NULL;
1122 	     pp = &p->next) {
1123 		if (timer_pending(&p->timer) ?
1124 		    time_after(p->timer.expires, now + max_delay) :
1125 		    try_to_del_timer_sync(&p->timer) >= 0)
1126 			mod_timer(&p->timer, now + max_delay);
1127 	}
1128 
1129 out:
1130 	spin_unlock(&br->multicast_lock);
1131 	return err;
1132 }
1133 
1134 #if IS_ENABLED(CONFIG_IPV6)
1135 static int br_ip6_multicast_query(struct net_bridge *br,
1136 				  struct net_bridge_port *port,
1137 				  struct sk_buff *skb)
1138 {
1139 	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
1140 	struct mld_msg *mld = (struct mld_msg *) icmp6_hdr(skb);
1141 	struct net_bridge_mdb_entry *mp;
1142 	struct mld2_query *mld2q;
1143 	struct net_bridge_port_group *p;
1144 	struct net_bridge_port_group __rcu **pp;
1145 	unsigned long max_delay;
1146 	unsigned long now = jiffies;
1147 	const struct in6_addr *group = NULL;
1148 	int err = 0;
1149 
1150 	spin_lock(&br->multicast_lock);
1151 	if (!netif_running(br->dev) ||
1152 	    (port && port->state == BR_STATE_DISABLED))
1153 		goto out;
1154 
1155 	br_multicast_query_received(br, port, !ipv6_addr_any(&ip6h->saddr));
1156 
1157 	if (skb->len == sizeof(*mld)) {
1158 		if (!pskb_may_pull(skb, sizeof(*mld))) {
1159 			err = -EINVAL;
1160 			goto out;
1161 		}
1162 		mld = (struct mld_msg *) icmp6_hdr(skb);
1163 		max_delay = msecs_to_jiffies(htons(mld->mld_maxdelay));
1164 		if (max_delay)
1165 			group = &mld->mld_mca;
1166 	} else if (skb->len >= sizeof(*mld2q)) {
1167 		if (!pskb_may_pull(skb, sizeof(*mld2q))) {
1168 			err = -EINVAL;
1169 			goto out;
1170 		}
1171 		mld2q = (struct mld2_query *)icmp6_hdr(skb);
1172 		if (!mld2q->mld2q_nsrcs)
1173 			group = &mld2q->mld2q_mca;
1174 		max_delay = mld2q->mld2q_mrc ? MLDV2_MRC(mld2q->mld2q_mrc) : 1;
1175 	}
1176 
1177 	if (!group)
1178 		goto out;
1179 
1180 	mp = br_mdb_ip6_get(mlock_dereference(br->mdb, br), group);
1181 	if (!mp)
1182 		goto out;
1183 
1184 	max_delay *= br->multicast_last_member_count;
1185 	if (mp->mglist &&
1186 	    (timer_pending(&mp->timer) ?
1187 	     time_after(mp->timer.expires, now + max_delay) :
1188 	     try_to_del_timer_sync(&mp->timer) >= 0))
1189 		mod_timer(&mp->timer, now + max_delay);
1190 
1191 	for (pp = &mp->ports;
1192 	     (p = mlock_dereference(*pp, br)) != NULL;
1193 	     pp = &p->next) {
1194 		if (timer_pending(&p->timer) ?
1195 		    time_after(p->timer.expires, now + max_delay) :
1196 		    try_to_del_timer_sync(&p->timer) >= 0)
1197 			mod_timer(&p->timer, now + max_delay);
1198 	}
1199 
1200 out:
1201 	spin_unlock(&br->multicast_lock);
1202 	return err;
1203 }
1204 #endif
1205 
1206 static void br_multicast_leave_group(struct net_bridge *br,
1207 				     struct net_bridge_port *port,
1208 				     struct br_ip *group)
1209 {
1210 	struct net_bridge_mdb_htable *mdb;
1211 	struct net_bridge_mdb_entry *mp;
1212 	struct net_bridge_port_group *p;
1213 	unsigned long now;
1214 	unsigned long time;
1215 
1216 	spin_lock(&br->multicast_lock);
1217 	if (!netif_running(br->dev) ||
1218 	    (port && port->state == BR_STATE_DISABLED) ||
1219 	    timer_pending(&br->multicast_querier_timer))
1220 		goto out;
1221 
1222 	mdb = mlock_dereference(br->mdb, br);
1223 	mp = br_mdb_ip_get(mdb, group);
1224 	if (!mp)
1225 		goto out;
1226 
1227 	now = jiffies;
1228 	time = now + br->multicast_last_member_count *
1229 		     br->multicast_last_member_interval;
1230 
1231 	if (!port) {
1232 		if (mp->mglist &&
1233 		    (timer_pending(&mp->timer) ?
1234 		     time_after(mp->timer.expires, time) :
1235 		     try_to_del_timer_sync(&mp->timer) >= 0)) {
1236 			mod_timer(&mp->timer, time);
1237 		}
1238 
1239 		goto out;
1240 	}
1241 
1242 	for (p = mlock_dereference(mp->ports, br);
1243 	     p != NULL;
1244 	     p = mlock_dereference(p->next, br)) {
1245 		if (p->port != port)
1246 			continue;
1247 
1248 		if (!hlist_unhashed(&p->mglist) &&
1249 		    (timer_pending(&p->timer) ?
1250 		     time_after(p->timer.expires, time) :
1251 		     try_to_del_timer_sync(&p->timer) >= 0)) {
1252 			mod_timer(&p->timer, time);
1253 		}
1254 
1255 		break;
1256 	}
1257 
1258 out:
1259 	spin_unlock(&br->multicast_lock);
1260 }
1261 
1262 static void br_ip4_multicast_leave_group(struct net_bridge *br,
1263 					 struct net_bridge_port *port,
1264 					 __be32 group)
1265 {
1266 	struct br_ip br_group;
1267 
1268 	if (ipv4_is_local_multicast(group))
1269 		return;
1270 
1271 	br_group.u.ip4 = group;
1272 	br_group.proto = htons(ETH_P_IP);
1273 
1274 	br_multicast_leave_group(br, port, &br_group);
1275 }
1276 
1277 #if IS_ENABLED(CONFIG_IPV6)
1278 static void br_ip6_multicast_leave_group(struct net_bridge *br,
1279 					 struct net_bridge_port *port,
1280 					 const struct in6_addr *group)
1281 {
1282 	struct br_ip br_group;
1283 
1284 	if (!ipv6_is_transient_multicast(group))
1285 		return;
1286 
1287 	br_group.u.ip6 = *group;
1288 	br_group.proto = htons(ETH_P_IPV6);
1289 
1290 	br_multicast_leave_group(br, port, &br_group);
1291 }
1292 #endif
1293 
1294 static int br_multicast_ipv4_rcv(struct net_bridge *br,
1295 				 struct net_bridge_port *port,
1296 				 struct sk_buff *skb)
1297 {
1298 	struct sk_buff *skb2 = skb;
1299 	const struct iphdr *iph;
1300 	struct igmphdr *ih;
1301 	unsigned int len;
1302 	unsigned int offset;
1303 	int err;
1304 
1305 	/* We treat OOM as packet loss for now. */
1306 	if (!pskb_may_pull(skb, sizeof(*iph)))
1307 		return -EINVAL;
1308 
1309 	iph = ip_hdr(skb);
1310 
1311 	if (iph->ihl < 5 || iph->version != 4)
1312 		return -EINVAL;
1313 
1314 	if (!pskb_may_pull(skb, ip_hdrlen(skb)))
1315 		return -EINVAL;
1316 
1317 	iph = ip_hdr(skb);
1318 
1319 	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1320 		return -EINVAL;
1321 
1322 	if (iph->protocol != IPPROTO_IGMP) {
1323 		if ((iph->daddr & IGMP_LOCAL_GROUP_MASK) != IGMP_LOCAL_GROUP)
1324 			BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
1325 		return 0;
1326 	}
1327 
1328 	len = ntohs(iph->tot_len);
1329 	if (skb->len < len || len < ip_hdrlen(skb))
1330 		return -EINVAL;
1331 
1332 	if (skb->len > len) {
1333 		skb2 = skb_clone(skb, GFP_ATOMIC);
1334 		if (!skb2)
1335 			return -ENOMEM;
1336 
1337 		err = pskb_trim_rcsum(skb2, len);
1338 		if (err)
1339 			goto err_out;
1340 	}
1341 
1342 	len -= ip_hdrlen(skb2);
1343 	offset = skb_network_offset(skb2) + ip_hdrlen(skb2);
1344 	__skb_pull(skb2, offset);
1345 	skb_reset_transport_header(skb2);
1346 
1347 	err = -EINVAL;
1348 	if (!pskb_may_pull(skb2, sizeof(*ih)))
1349 		goto out;
1350 
1351 	switch (skb2->ip_summed) {
1352 	case CHECKSUM_COMPLETE:
1353 		if (!csum_fold(skb2->csum))
1354 			break;
1355 		/* fall through */
1356 	case CHECKSUM_NONE:
1357 		skb2->csum = 0;
1358 		if (skb_checksum_complete(skb2))
1359 			goto out;
1360 	}
1361 
1362 	err = 0;
1363 
1364 	BR_INPUT_SKB_CB(skb)->igmp = 1;
1365 	ih = igmp_hdr(skb2);
1366 
1367 	switch (ih->type) {
1368 	case IGMP_HOST_MEMBERSHIP_REPORT:
1369 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
1370 		BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
1371 		err = br_ip4_multicast_add_group(br, port, ih->group);
1372 		break;
1373 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
1374 		err = br_ip4_multicast_igmp3_report(br, port, skb2);
1375 		break;
1376 	case IGMP_HOST_MEMBERSHIP_QUERY:
1377 		err = br_ip4_multicast_query(br, port, skb2);
1378 		break;
1379 	case IGMP_HOST_LEAVE_MESSAGE:
1380 		br_ip4_multicast_leave_group(br, port, ih->group);
1381 		break;
1382 	}
1383 
1384 out:
1385 	__skb_push(skb2, offset);
1386 err_out:
1387 	if (skb2 != skb)
1388 		kfree_skb(skb2);
1389 	return err;
1390 }
1391 
1392 #if IS_ENABLED(CONFIG_IPV6)
1393 static int br_multicast_ipv6_rcv(struct net_bridge *br,
1394 				 struct net_bridge_port *port,
1395 				 struct sk_buff *skb)
1396 {
1397 	struct sk_buff *skb2;
1398 	const struct ipv6hdr *ip6h;
1399 	u8 icmp6_type;
1400 	u8 nexthdr;
1401 	__be16 frag_off;
1402 	unsigned int len;
1403 	int offset;
1404 	int err;
1405 
1406 	if (!pskb_may_pull(skb, sizeof(*ip6h)))
1407 		return -EINVAL;
1408 
1409 	ip6h = ipv6_hdr(skb);
1410 
1411 	/*
1412 	 * We're interested in MLD messages only.
1413 	 *  - Version is 6
1414 	 *  - MLD has always Router Alert hop-by-hop option
1415 	 *  - But we do not support jumbrograms.
1416 	 */
1417 	if (ip6h->version != 6 ||
1418 	    ip6h->nexthdr != IPPROTO_HOPOPTS ||
1419 	    ip6h->payload_len == 0)
1420 		return 0;
1421 
1422 	len = ntohs(ip6h->payload_len) + sizeof(*ip6h);
1423 	if (skb->len < len)
1424 		return -EINVAL;
1425 
1426 	nexthdr = ip6h->nexthdr;
1427 	offset = ipv6_skip_exthdr(skb, sizeof(*ip6h), &nexthdr, &frag_off);
1428 
1429 	if (offset < 0 || nexthdr != IPPROTO_ICMPV6)
1430 		return 0;
1431 
1432 	/* Okay, we found ICMPv6 header */
1433 	skb2 = skb_clone(skb, GFP_ATOMIC);
1434 	if (!skb2)
1435 		return -ENOMEM;
1436 
1437 	err = -EINVAL;
1438 	if (!pskb_may_pull(skb2, offset + sizeof(struct icmp6hdr)))
1439 		goto out;
1440 
1441 	len -= offset - skb_network_offset(skb2);
1442 
1443 	__skb_pull(skb2, offset);
1444 	skb_reset_transport_header(skb2);
1445 	skb_postpull_rcsum(skb2, skb_network_header(skb2),
1446 			   skb_network_header_len(skb2));
1447 
1448 	icmp6_type = icmp6_hdr(skb2)->icmp6_type;
1449 
1450 	switch (icmp6_type) {
1451 	case ICMPV6_MGM_QUERY:
1452 	case ICMPV6_MGM_REPORT:
1453 	case ICMPV6_MGM_REDUCTION:
1454 	case ICMPV6_MLD2_REPORT:
1455 		break;
1456 	default:
1457 		err = 0;
1458 		goto out;
1459 	}
1460 
1461 	/* Okay, we found MLD message. Check further. */
1462 	if (skb2->len > len) {
1463 		err = pskb_trim_rcsum(skb2, len);
1464 		if (err)
1465 			goto out;
1466 		err = -EINVAL;
1467 	}
1468 
1469 	ip6h = ipv6_hdr(skb2);
1470 
1471 	switch (skb2->ip_summed) {
1472 	case CHECKSUM_COMPLETE:
1473 		if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, skb2->len,
1474 					IPPROTO_ICMPV6, skb2->csum))
1475 			break;
1476 		/*FALLTHROUGH*/
1477 	case CHECKSUM_NONE:
1478 		skb2->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr,
1479 							&ip6h->daddr,
1480 							skb2->len,
1481 							IPPROTO_ICMPV6, 0));
1482 		if (__skb_checksum_complete(skb2))
1483 			goto out;
1484 	}
1485 
1486 	err = 0;
1487 
1488 	BR_INPUT_SKB_CB(skb)->igmp = 1;
1489 
1490 	switch (icmp6_type) {
1491 	case ICMPV6_MGM_REPORT:
1492 	    {
1493 		struct mld_msg *mld;
1494 		if (!pskb_may_pull(skb2, sizeof(*mld))) {
1495 			err = -EINVAL;
1496 			goto out;
1497 		}
1498 		mld = (struct mld_msg *)skb_transport_header(skb2);
1499 		BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
1500 		err = br_ip6_multicast_add_group(br, port, &mld->mld_mca);
1501 		break;
1502 	    }
1503 	case ICMPV6_MLD2_REPORT:
1504 		err = br_ip6_multicast_mld2_report(br, port, skb2);
1505 		break;
1506 	case ICMPV6_MGM_QUERY:
1507 		err = br_ip6_multicast_query(br, port, skb2);
1508 		break;
1509 	case ICMPV6_MGM_REDUCTION:
1510 	    {
1511 		struct mld_msg *mld;
1512 		if (!pskb_may_pull(skb2, sizeof(*mld))) {
1513 			err = -EINVAL;
1514 			goto out;
1515 		}
1516 		mld = (struct mld_msg *)skb_transport_header(skb2);
1517 		br_ip6_multicast_leave_group(br, port, &mld->mld_mca);
1518 	    }
1519 	}
1520 
1521 out:
1522 	kfree_skb(skb2);
1523 	return err;
1524 }
1525 #endif
1526 
1527 int br_multicast_rcv(struct net_bridge *br, struct net_bridge_port *port,
1528 		     struct sk_buff *skb)
1529 {
1530 	BR_INPUT_SKB_CB(skb)->igmp = 0;
1531 	BR_INPUT_SKB_CB(skb)->mrouters_only = 0;
1532 
1533 	if (br->multicast_disabled)
1534 		return 0;
1535 
1536 	switch (skb->protocol) {
1537 	case htons(ETH_P_IP):
1538 		return br_multicast_ipv4_rcv(br, port, skb);
1539 #if IS_ENABLED(CONFIG_IPV6)
1540 	case htons(ETH_P_IPV6):
1541 		return br_multicast_ipv6_rcv(br, port, skb);
1542 #endif
1543 	}
1544 
1545 	return 0;
1546 }
1547 
1548 static void br_multicast_query_expired(unsigned long data)
1549 {
1550 	struct net_bridge *br = (void *)data;
1551 
1552 	spin_lock(&br->multicast_lock);
1553 	if (br->multicast_startup_queries_sent <
1554 	    br->multicast_startup_query_count)
1555 		br->multicast_startup_queries_sent++;
1556 
1557 	br_multicast_send_query(br, NULL, br->multicast_startup_queries_sent);
1558 
1559 	spin_unlock(&br->multicast_lock);
1560 }
1561 
1562 void br_multicast_init(struct net_bridge *br)
1563 {
1564 	br->hash_elasticity = 4;
1565 	br->hash_max = 512;
1566 
1567 	br->multicast_router = 1;
1568 	br->multicast_querier = 0;
1569 	br->multicast_last_member_count = 2;
1570 	br->multicast_startup_query_count = 2;
1571 
1572 	br->multicast_last_member_interval = HZ;
1573 	br->multicast_query_response_interval = 10 * HZ;
1574 	br->multicast_startup_query_interval = 125 * HZ / 4;
1575 	br->multicast_query_interval = 125 * HZ;
1576 	br->multicast_querier_interval = 255 * HZ;
1577 	br->multicast_membership_interval = 260 * HZ;
1578 
1579 	spin_lock_init(&br->multicast_lock);
1580 	setup_timer(&br->multicast_router_timer,
1581 		    br_multicast_local_router_expired, 0);
1582 	setup_timer(&br->multicast_querier_timer,
1583 		    br_multicast_querier_expired, (unsigned long)br);
1584 	setup_timer(&br->multicast_query_timer, br_multicast_query_expired,
1585 		    (unsigned long)br);
1586 }
1587 
1588 void br_multicast_open(struct net_bridge *br)
1589 {
1590 	br->multicast_startup_queries_sent = 0;
1591 
1592 	if (br->multicast_disabled)
1593 		return;
1594 
1595 	mod_timer(&br->multicast_query_timer, jiffies);
1596 }
1597 
1598 void br_multicast_stop(struct net_bridge *br)
1599 {
1600 	struct net_bridge_mdb_htable *mdb;
1601 	struct net_bridge_mdb_entry *mp;
1602 	struct hlist_node *p, *n;
1603 	u32 ver;
1604 	int i;
1605 
1606 	del_timer_sync(&br->multicast_router_timer);
1607 	del_timer_sync(&br->multicast_querier_timer);
1608 	del_timer_sync(&br->multicast_query_timer);
1609 
1610 	spin_lock_bh(&br->multicast_lock);
1611 	mdb = mlock_dereference(br->mdb, br);
1612 	if (!mdb)
1613 		goto out;
1614 
1615 	br->mdb = NULL;
1616 
1617 	ver = mdb->ver;
1618 	for (i = 0; i < mdb->max; i++) {
1619 		hlist_for_each_entry_safe(mp, p, n, &mdb->mhash[i],
1620 					  hlist[ver]) {
1621 			del_timer(&mp->timer);
1622 			call_rcu_bh(&mp->rcu, br_multicast_free_group);
1623 		}
1624 	}
1625 
1626 	if (mdb->old) {
1627 		spin_unlock_bh(&br->multicast_lock);
1628 		rcu_barrier_bh();
1629 		spin_lock_bh(&br->multicast_lock);
1630 		WARN_ON(mdb->old);
1631 	}
1632 
1633 	mdb->old = mdb;
1634 	call_rcu_bh(&mdb->rcu, br_mdb_free);
1635 
1636 out:
1637 	spin_unlock_bh(&br->multicast_lock);
1638 }
1639 
1640 int br_multicast_set_router(struct net_bridge *br, unsigned long val)
1641 {
1642 	int err = -ENOENT;
1643 
1644 	spin_lock_bh(&br->multicast_lock);
1645 	if (!netif_running(br->dev))
1646 		goto unlock;
1647 
1648 	switch (val) {
1649 	case 0:
1650 	case 2:
1651 		del_timer(&br->multicast_router_timer);
1652 		/* fall through */
1653 	case 1:
1654 		br->multicast_router = val;
1655 		err = 0;
1656 		break;
1657 
1658 	default:
1659 		err = -EINVAL;
1660 		break;
1661 	}
1662 
1663 unlock:
1664 	spin_unlock_bh(&br->multicast_lock);
1665 
1666 	return err;
1667 }
1668 
1669 int br_multicast_set_port_router(struct net_bridge_port *p, unsigned long val)
1670 {
1671 	struct net_bridge *br = p->br;
1672 	int err = -ENOENT;
1673 
1674 	spin_lock(&br->multicast_lock);
1675 	if (!netif_running(br->dev) || p->state == BR_STATE_DISABLED)
1676 		goto unlock;
1677 
1678 	switch (val) {
1679 	case 0:
1680 	case 1:
1681 	case 2:
1682 		p->multicast_router = val;
1683 		err = 0;
1684 
1685 		if (val < 2 && !hlist_unhashed(&p->rlist))
1686 			hlist_del_init_rcu(&p->rlist);
1687 
1688 		if (val == 1)
1689 			break;
1690 
1691 		del_timer(&p->multicast_router_timer);
1692 
1693 		if (val == 0)
1694 			break;
1695 
1696 		br_multicast_add_router(br, p);
1697 		break;
1698 
1699 	default:
1700 		err = -EINVAL;
1701 		break;
1702 	}
1703 
1704 unlock:
1705 	spin_unlock(&br->multicast_lock);
1706 
1707 	return err;
1708 }
1709 
1710 static void br_multicast_start_querier(struct net_bridge *br)
1711 {
1712 	struct net_bridge_port *port;
1713 
1714 	br_multicast_open(br);
1715 
1716 	list_for_each_entry(port, &br->port_list, list) {
1717 		if (port->state == BR_STATE_DISABLED ||
1718 		    port->state == BR_STATE_BLOCKING)
1719 			continue;
1720 
1721 		__br_multicast_enable_port(port);
1722 	}
1723 }
1724 
1725 int br_multicast_toggle(struct net_bridge *br, unsigned long val)
1726 {
1727 	int err = 0;
1728 	struct net_bridge_mdb_htable *mdb;
1729 
1730 	spin_lock_bh(&br->multicast_lock);
1731 	if (br->multicast_disabled == !val)
1732 		goto unlock;
1733 
1734 	br->multicast_disabled = !val;
1735 	if (br->multicast_disabled)
1736 		goto unlock;
1737 
1738 	if (!netif_running(br->dev))
1739 		goto unlock;
1740 
1741 	mdb = mlock_dereference(br->mdb, br);
1742 	if (mdb) {
1743 		if (mdb->old) {
1744 			err = -EEXIST;
1745 rollback:
1746 			br->multicast_disabled = !!val;
1747 			goto unlock;
1748 		}
1749 
1750 		err = br_mdb_rehash(&br->mdb, mdb->max,
1751 				    br->hash_elasticity);
1752 		if (err)
1753 			goto rollback;
1754 	}
1755 
1756 	br_multicast_start_querier(br);
1757 
1758 unlock:
1759 	spin_unlock_bh(&br->multicast_lock);
1760 
1761 	return err;
1762 }
1763 
1764 int br_multicast_set_querier(struct net_bridge *br, unsigned long val)
1765 {
1766 	val = !!val;
1767 
1768 	spin_lock_bh(&br->multicast_lock);
1769 	if (br->multicast_querier == val)
1770 		goto unlock;
1771 
1772 	br->multicast_querier = val;
1773 	if (val)
1774 		br_multicast_start_querier(br);
1775 
1776 unlock:
1777 	spin_unlock_bh(&br->multicast_lock);
1778 
1779 	return 0;
1780 }
1781 
1782 int br_multicast_set_hash_max(struct net_bridge *br, unsigned long val)
1783 {
1784 	int err = -ENOENT;
1785 	u32 old;
1786 	struct net_bridge_mdb_htable *mdb;
1787 
1788 	spin_lock(&br->multicast_lock);
1789 	if (!netif_running(br->dev))
1790 		goto unlock;
1791 
1792 	err = -EINVAL;
1793 	if (!is_power_of_2(val))
1794 		goto unlock;
1795 
1796 	mdb = mlock_dereference(br->mdb, br);
1797 	if (mdb && val < mdb->size)
1798 		goto unlock;
1799 
1800 	err = 0;
1801 
1802 	old = br->hash_max;
1803 	br->hash_max = val;
1804 
1805 	if (mdb) {
1806 		if (mdb->old) {
1807 			err = -EEXIST;
1808 rollback:
1809 			br->hash_max = old;
1810 			goto unlock;
1811 		}
1812 
1813 		err = br_mdb_rehash(&br->mdb, br->hash_max,
1814 				    br->hash_elasticity);
1815 		if (err)
1816 			goto rollback;
1817 	}
1818 
1819 unlock:
1820 	spin_unlock(&br->multicast_lock);
1821 
1822 	return err;
1823 }
1824