xref: /openbmc/linux/net/bridge/br_multicast.c (revision 95e9fd10)
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 of %d "
545 				"reached, disabling snooping: %s\n",
546 				br->hash_max,
547 				port ? port->dev->name : br->dev->name);
548 			err = -E2BIG;
549 disable:
550 			br->multicast_disabled = 1;
551 			goto err;
552 		}
553 	}
554 
555 	if (max > mdb->max || elasticity) {
556 		if (mdb->old) {
557 			if (net_ratelimit())
558 				br_info(br, "Multicast hash table "
559 					"on fire: %s\n",
560 					port ? port->dev->name : br->dev->name);
561 			err = -EEXIST;
562 			goto err;
563 		}
564 
565 		err = br_mdb_rehash(&br->mdb, max, elasticity);
566 		if (err) {
567 			br_warn(br, "Cannot rehash multicast "
568 				"hash table, disabling snooping: %s, %d, %d\n",
569 				port ? port->dev->name : br->dev->name,
570 				mdb->size, err);
571 			goto disable;
572 		}
573 
574 		err = -EAGAIN;
575 		goto err;
576 	}
577 
578 	return NULL;
579 
580 err:
581 	mp = ERR_PTR(err);
582 	return mp;
583 }
584 
585 static struct net_bridge_mdb_entry *br_multicast_new_group(
586 	struct net_bridge *br, struct net_bridge_port *port,
587 	struct br_ip *group)
588 {
589 	struct net_bridge_mdb_htable *mdb;
590 	struct net_bridge_mdb_entry *mp;
591 	int hash;
592 	int err;
593 
594 	mdb = rcu_dereference_protected(br->mdb, 1);
595 	if (!mdb) {
596 		err = br_mdb_rehash(&br->mdb, BR_HASH_SIZE, 0);
597 		if (err)
598 			return ERR_PTR(err);
599 		goto rehash;
600 	}
601 
602 	hash = br_ip_hash(mdb, group);
603 	mp = br_multicast_get_group(br, port, group, hash);
604 	switch (PTR_ERR(mp)) {
605 	case 0:
606 		break;
607 
608 	case -EAGAIN:
609 rehash:
610 		mdb = rcu_dereference_protected(br->mdb, 1);
611 		hash = br_ip_hash(mdb, group);
612 		break;
613 
614 	default:
615 		goto out;
616 	}
617 
618 	mp = kzalloc(sizeof(*mp), GFP_ATOMIC);
619 	if (unlikely(!mp))
620 		return ERR_PTR(-ENOMEM);
621 
622 	mp->br = br;
623 	mp->addr = *group;
624 	setup_timer(&mp->timer, br_multicast_group_expired,
625 		    (unsigned long)mp);
626 
627 	hlist_add_head_rcu(&mp->hlist[mdb->ver], &mdb->mhash[hash]);
628 	mdb->size++;
629 
630 out:
631 	return mp;
632 }
633 
634 static int br_multicast_add_group(struct net_bridge *br,
635 				  struct net_bridge_port *port,
636 				  struct br_ip *group)
637 {
638 	struct net_bridge_mdb_entry *mp;
639 	struct net_bridge_port_group *p;
640 	struct net_bridge_port_group __rcu **pp;
641 	unsigned long now = jiffies;
642 	int err;
643 
644 	spin_lock(&br->multicast_lock);
645 	if (!netif_running(br->dev) ||
646 	    (port && port->state == BR_STATE_DISABLED))
647 		goto out;
648 
649 	mp = br_multicast_new_group(br, port, group);
650 	err = PTR_ERR(mp);
651 	if (IS_ERR(mp))
652 		goto err;
653 
654 	if (!port) {
655 		mp->mglist = true;
656 		mod_timer(&mp->timer, now + br->multicast_membership_interval);
657 		goto out;
658 	}
659 
660 	for (pp = &mp->ports;
661 	     (p = mlock_dereference(*pp, br)) != NULL;
662 	     pp = &p->next) {
663 		if (p->port == port)
664 			goto found;
665 		if ((unsigned long)p->port < (unsigned long)port)
666 			break;
667 	}
668 
669 	p = kzalloc(sizeof(*p), GFP_ATOMIC);
670 	err = -ENOMEM;
671 	if (unlikely(!p))
672 		goto err;
673 
674 	p->addr = *group;
675 	p->port = port;
676 	p->next = *pp;
677 	hlist_add_head(&p->mglist, &port->mglist);
678 	setup_timer(&p->timer, br_multicast_port_group_expired,
679 		    (unsigned long)p);
680 
681 	rcu_assign_pointer(*pp, p);
682 
683 found:
684 	mod_timer(&p->timer, now + br->multicast_membership_interval);
685 out:
686 	err = 0;
687 
688 err:
689 	spin_unlock(&br->multicast_lock);
690 	return err;
691 }
692 
693 static int br_ip4_multicast_add_group(struct net_bridge *br,
694 				      struct net_bridge_port *port,
695 				      __be32 group)
696 {
697 	struct br_ip br_group;
698 
699 	if (ipv4_is_local_multicast(group))
700 		return 0;
701 
702 	br_group.u.ip4 = group;
703 	br_group.proto = htons(ETH_P_IP);
704 
705 	return br_multicast_add_group(br, port, &br_group);
706 }
707 
708 #if IS_ENABLED(CONFIG_IPV6)
709 static int br_ip6_multicast_add_group(struct net_bridge *br,
710 				      struct net_bridge_port *port,
711 				      const struct in6_addr *group)
712 {
713 	struct br_ip br_group;
714 
715 	if (!ipv6_is_transient_multicast(group))
716 		return 0;
717 
718 	br_group.u.ip6 = *group;
719 	br_group.proto = htons(ETH_P_IPV6);
720 
721 	return br_multicast_add_group(br, port, &br_group);
722 }
723 #endif
724 
725 static void br_multicast_router_expired(unsigned long data)
726 {
727 	struct net_bridge_port *port = (void *)data;
728 	struct net_bridge *br = port->br;
729 
730 	spin_lock(&br->multicast_lock);
731 	if (port->multicast_router != 1 ||
732 	    timer_pending(&port->multicast_router_timer) ||
733 	    hlist_unhashed(&port->rlist))
734 		goto out;
735 
736 	hlist_del_init_rcu(&port->rlist);
737 
738 out:
739 	spin_unlock(&br->multicast_lock);
740 }
741 
742 static void br_multicast_local_router_expired(unsigned long data)
743 {
744 }
745 
746 static void br_multicast_querier_expired(unsigned long data)
747 {
748 	struct net_bridge *br = (void *)data;
749 
750 	spin_lock(&br->multicast_lock);
751 	if (!netif_running(br->dev) || br->multicast_disabled)
752 		goto out;
753 
754 	br_multicast_start_querier(br);
755 
756 out:
757 	spin_unlock(&br->multicast_lock);
758 }
759 
760 static void __br_multicast_send_query(struct net_bridge *br,
761 				      struct net_bridge_port *port,
762 				      struct br_ip *ip)
763 {
764 	struct sk_buff *skb;
765 
766 	skb = br_multicast_alloc_query(br, ip);
767 	if (!skb)
768 		return;
769 
770 	if (port) {
771 		__skb_push(skb, sizeof(struct ethhdr));
772 		skb->dev = port->dev;
773 		NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
774 			dev_queue_xmit);
775 	} else
776 		netif_rx(skb);
777 }
778 
779 static void br_multicast_send_query(struct net_bridge *br,
780 				    struct net_bridge_port *port, u32 sent)
781 {
782 	unsigned long time;
783 	struct br_ip br_group;
784 
785 	if (!netif_running(br->dev) || br->multicast_disabled ||
786 	    !br->multicast_querier ||
787 	    timer_pending(&br->multicast_querier_timer))
788 		return;
789 
790 	memset(&br_group.u, 0, sizeof(br_group.u));
791 
792 	br_group.proto = htons(ETH_P_IP);
793 	__br_multicast_send_query(br, port, &br_group);
794 
795 #if IS_ENABLED(CONFIG_IPV6)
796 	br_group.proto = htons(ETH_P_IPV6);
797 	__br_multicast_send_query(br, port, &br_group);
798 #endif
799 
800 	time = jiffies;
801 	time += sent < br->multicast_startup_query_count ?
802 		br->multicast_startup_query_interval :
803 		br->multicast_query_interval;
804 	mod_timer(port ? &port->multicast_query_timer :
805 			 &br->multicast_query_timer, time);
806 }
807 
808 static void br_multicast_port_query_expired(unsigned long data)
809 {
810 	struct net_bridge_port *port = (void *)data;
811 	struct net_bridge *br = port->br;
812 
813 	spin_lock(&br->multicast_lock);
814 	if (port->state == BR_STATE_DISABLED ||
815 	    port->state == BR_STATE_BLOCKING)
816 		goto out;
817 
818 	if (port->multicast_startup_queries_sent <
819 	    br->multicast_startup_query_count)
820 		port->multicast_startup_queries_sent++;
821 
822 	br_multicast_send_query(port->br, port,
823 				port->multicast_startup_queries_sent);
824 
825 out:
826 	spin_unlock(&br->multicast_lock);
827 }
828 
829 void br_multicast_add_port(struct net_bridge_port *port)
830 {
831 	port->multicast_router = 1;
832 
833 	setup_timer(&port->multicast_router_timer, br_multicast_router_expired,
834 		    (unsigned long)port);
835 	setup_timer(&port->multicast_query_timer,
836 		    br_multicast_port_query_expired, (unsigned long)port);
837 }
838 
839 void br_multicast_del_port(struct net_bridge_port *port)
840 {
841 	del_timer_sync(&port->multicast_router_timer);
842 }
843 
844 static void __br_multicast_enable_port(struct net_bridge_port *port)
845 {
846 	port->multicast_startup_queries_sent = 0;
847 
848 	if (try_to_del_timer_sync(&port->multicast_query_timer) >= 0 ||
849 	    del_timer(&port->multicast_query_timer))
850 		mod_timer(&port->multicast_query_timer, jiffies);
851 }
852 
853 void br_multicast_enable_port(struct net_bridge_port *port)
854 {
855 	struct net_bridge *br = port->br;
856 
857 	spin_lock(&br->multicast_lock);
858 	if (br->multicast_disabled || !netif_running(br->dev))
859 		goto out;
860 
861 	__br_multicast_enable_port(port);
862 
863 out:
864 	spin_unlock(&br->multicast_lock);
865 }
866 
867 void br_multicast_disable_port(struct net_bridge_port *port)
868 {
869 	struct net_bridge *br = port->br;
870 	struct net_bridge_port_group *pg;
871 	struct hlist_node *p, *n;
872 
873 	spin_lock(&br->multicast_lock);
874 	hlist_for_each_entry_safe(pg, p, n, &port->mglist, mglist)
875 		br_multicast_del_pg(br, pg);
876 
877 	if (!hlist_unhashed(&port->rlist))
878 		hlist_del_init_rcu(&port->rlist);
879 	del_timer(&port->multicast_router_timer);
880 	del_timer(&port->multicast_query_timer);
881 	spin_unlock(&br->multicast_lock);
882 }
883 
884 static int br_ip4_multicast_igmp3_report(struct net_bridge *br,
885 					 struct net_bridge_port *port,
886 					 struct sk_buff *skb)
887 {
888 	struct igmpv3_report *ih;
889 	struct igmpv3_grec *grec;
890 	int i;
891 	int len;
892 	int num;
893 	int type;
894 	int err = 0;
895 	__be32 group;
896 
897 	if (!pskb_may_pull(skb, sizeof(*ih)))
898 		return -EINVAL;
899 
900 	ih = igmpv3_report_hdr(skb);
901 	num = ntohs(ih->ngrec);
902 	len = sizeof(*ih);
903 
904 	for (i = 0; i < num; i++) {
905 		len += sizeof(*grec);
906 		if (!pskb_may_pull(skb, len))
907 			return -EINVAL;
908 
909 		grec = (void *)(skb->data + len - sizeof(*grec));
910 		group = grec->grec_mca;
911 		type = grec->grec_type;
912 
913 		len += ntohs(grec->grec_nsrcs) * 4;
914 		if (!pskb_may_pull(skb, len))
915 			return -EINVAL;
916 
917 		/* We treat this as an IGMPv2 report for now. */
918 		switch (type) {
919 		case IGMPV3_MODE_IS_INCLUDE:
920 		case IGMPV3_MODE_IS_EXCLUDE:
921 		case IGMPV3_CHANGE_TO_INCLUDE:
922 		case IGMPV3_CHANGE_TO_EXCLUDE:
923 		case IGMPV3_ALLOW_NEW_SOURCES:
924 		case IGMPV3_BLOCK_OLD_SOURCES:
925 			break;
926 
927 		default:
928 			continue;
929 		}
930 
931 		err = br_ip4_multicast_add_group(br, port, group);
932 		if (err)
933 			break;
934 	}
935 
936 	return err;
937 }
938 
939 #if IS_ENABLED(CONFIG_IPV6)
940 static int br_ip6_multicast_mld2_report(struct net_bridge *br,
941 					struct net_bridge_port *port,
942 					struct sk_buff *skb)
943 {
944 	struct icmp6hdr *icmp6h;
945 	struct mld2_grec *grec;
946 	int i;
947 	int len;
948 	int num;
949 	int err = 0;
950 
951 	if (!pskb_may_pull(skb, sizeof(*icmp6h)))
952 		return -EINVAL;
953 
954 	icmp6h = icmp6_hdr(skb);
955 	num = ntohs(icmp6h->icmp6_dataun.un_data16[1]);
956 	len = sizeof(*icmp6h);
957 
958 	for (i = 0; i < num; i++) {
959 		__be16 *nsrcs, _nsrcs;
960 
961 		nsrcs = skb_header_pointer(skb,
962 					   len + offsetof(struct mld2_grec,
963 							  grec_nsrcs),
964 					   sizeof(_nsrcs), &_nsrcs);
965 		if (!nsrcs)
966 			return -EINVAL;
967 
968 		if (!pskb_may_pull(skb,
969 				   len + sizeof(*grec) +
970 				   sizeof(struct in6_addr) * ntohs(*nsrcs)))
971 			return -EINVAL;
972 
973 		grec = (struct mld2_grec *)(skb->data + len);
974 		len += sizeof(*grec) +
975 		       sizeof(struct in6_addr) * ntohs(*nsrcs);
976 
977 		/* We treat these as MLDv1 reports for now. */
978 		switch (grec->grec_type) {
979 		case MLD2_MODE_IS_INCLUDE:
980 		case MLD2_MODE_IS_EXCLUDE:
981 		case MLD2_CHANGE_TO_INCLUDE:
982 		case MLD2_CHANGE_TO_EXCLUDE:
983 		case MLD2_ALLOW_NEW_SOURCES:
984 		case MLD2_BLOCK_OLD_SOURCES:
985 			break;
986 
987 		default:
988 			continue;
989 		}
990 
991 		err = br_ip6_multicast_add_group(br, port, &grec->grec_mca);
992 		if (!err)
993 			break;
994 	}
995 
996 	return err;
997 }
998 #endif
999 
1000 /*
1001  * Add port to rotuer_list
1002  *  list is maintained ordered by pointer value
1003  *  and locked by br->multicast_lock and RCU
1004  */
1005 static void br_multicast_add_router(struct net_bridge *br,
1006 				    struct net_bridge_port *port)
1007 {
1008 	struct net_bridge_port *p;
1009 	struct hlist_node *n, *slot = NULL;
1010 
1011 	hlist_for_each_entry(p, n, &br->router_list, rlist) {
1012 		if ((unsigned long) port >= (unsigned long) p)
1013 			break;
1014 		slot = n;
1015 	}
1016 
1017 	if (slot)
1018 		hlist_add_after_rcu(slot, &port->rlist);
1019 	else
1020 		hlist_add_head_rcu(&port->rlist, &br->router_list);
1021 }
1022 
1023 static void br_multicast_mark_router(struct net_bridge *br,
1024 				     struct net_bridge_port *port)
1025 {
1026 	unsigned long now = jiffies;
1027 
1028 	if (!port) {
1029 		if (br->multicast_router == 1)
1030 			mod_timer(&br->multicast_router_timer,
1031 				  now + br->multicast_querier_interval);
1032 		return;
1033 	}
1034 
1035 	if (port->multicast_router != 1)
1036 		return;
1037 
1038 	if (!hlist_unhashed(&port->rlist))
1039 		goto timer;
1040 
1041 	br_multicast_add_router(br, port);
1042 
1043 timer:
1044 	mod_timer(&port->multicast_router_timer,
1045 		  now + br->multicast_querier_interval);
1046 }
1047 
1048 static void br_multicast_query_received(struct net_bridge *br,
1049 					struct net_bridge_port *port,
1050 					int saddr)
1051 {
1052 	if (saddr)
1053 		mod_timer(&br->multicast_querier_timer,
1054 			  jiffies + br->multicast_querier_interval);
1055 	else if (timer_pending(&br->multicast_querier_timer))
1056 		return;
1057 
1058 	br_multicast_mark_router(br, port);
1059 }
1060 
1061 static int br_ip4_multicast_query(struct net_bridge *br,
1062 				  struct net_bridge_port *port,
1063 				  struct sk_buff *skb)
1064 {
1065 	const struct iphdr *iph = ip_hdr(skb);
1066 	struct igmphdr *ih = igmp_hdr(skb);
1067 	struct net_bridge_mdb_entry *mp;
1068 	struct igmpv3_query *ih3;
1069 	struct net_bridge_port_group *p;
1070 	struct net_bridge_port_group __rcu **pp;
1071 	unsigned long max_delay;
1072 	unsigned long now = jiffies;
1073 	__be32 group;
1074 	int err = 0;
1075 
1076 	spin_lock(&br->multicast_lock);
1077 	if (!netif_running(br->dev) ||
1078 	    (port && port->state == BR_STATE_DISABLED))
1079 		goto out;
1080 
1081 	br_multicast_query_received(br, port, !!iph->saddr);
1082 
1083 	group = ih->group;
1084 
1085 	if (skb->len == sizeof(*ih)) {
1086 		max_delay = ih->code * (HZ / IGMP_TIMER_SCALE);
1087 
1088 		if (!max_delay) {
1089 			max_delay = 10 * HZ;
1090 			group = 0;
1091 		}
1092 	} else {
1093 		if (!pskb_may_pull(skb, sizeof(struct igmpv3_query))) {
1094 			err = -EINVAL;
1095 			goto out;
1096 		}
1097 
1098 		ih3 = igmpv3_query_hdr(skb);
1099 		if (ih3->nsrcs)
1100 			goto out;
1101 
1102 		max_delay = ih3->code ?
1103 			    IGMPV3_MRC(ih3->code) * (HZ / IGMP_TIMER_SCALE) : 1;
1104 	}
1105 
1106 	if (!group)
1107 		goto out;
1108 
1109 	mp = br_mdb_ip4_get(mlock_dereference(br->mdb, br), group);
1110 	if (!mp)
1111 		goto out;
1112 
1113 	max_delay *= br->multicast_last_member_count;
1114 
1115 	if (mp->mglist &&
1116 	    (timer_pending(&mp->timer) ?
1117 	     time_after(mp->timer.expires, now + max_delay) :
1118 	     try_to_del_timer_sync(&mp->timer) >= 0))
1119 		mod_timer(&mp->timer, now + max_delay);
1120 
1121 	for (pp = &mp->ports;
1122 	     (p = mlock_dereference(*pp, br)) != NULL;
1123 	     pp = &p->next) {
1124 		if (timer_pending(&p->timer) ?
1125 		    time_after(p->timer.expires, now + max_delay) :
1126 		    try_to_del_timer_sync(&p->timer) >= 0)
1127 			mod_timer(&p->timer, now + max_delay);
1128 	}
1129 
1130 out:
1131 	spin_unlock(&br->multicast_lock);
1132 	return err;
1133 }
1134 
1135 #if IS_ENABLED(CONFIG_IPV6)
1136 static int br_ip6_multicast_query(struct net_bridge *br,
1137 				  struct net_bridge_port *port,
1138 				  struct sk_buff *skb)
1139 {
1140 	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
1141 	struct mld_msg *mld = (struct mld_msg *) icmp6_hdr(skb);
1142 	struct net_bridge_mdb_entry *mp;
1143 	struct mld2_query *mld2q;
1144 	struct net_bridge_port_group *p;
1145 	struct net_bridge_port_group __rcu **pp;
1146 	unsigned long max_delay;
1147 	unsigned long now = jiffies;
1148 	const struct in6_addr *group = NULL;
1149 	int err = 0;
1150 
1151 	spin_lock(&br->multicast_lock);
1152 	if (!netif_running(br->dev) ||
1153 	    (port && port->state == BR_STATE_DISABLED))
1154 		goto out;
1155 
1156 	br_multicast_query_received(br, port, !ipv6_addr_any(&ip6h->saddr));
1157 
1158 	if (skb->len == sizeof(*mld)) {
1159 		if (!pskb_may_pull(skb, sizeof(*mld))) {
1160 			err = -EINVAL;
1161 			goto out;
1162 		}
1163 		mld = (struct mld_msg *) icmp6_hdr(skb);
1164 		max_delay = msecs_to_jiffies(ntohs(mld->mld_maxdelay));
1165 		if (max_delay)
1166 			group = &mld->mld_mca;
1167 	} else if (skb->len >= sizeof(*mld2q)) {
1168 		if (!pskb_may_pull(skb, sizeof(*mld2q))) {
1169 			err = -EINVAL;
1170 			goto out;
1171 		}
1172 		mld2q = (struct mld2_query *)icmp6_hdr(skb);
1173 		if (!mld2q->mld2q_nsrcs)
1174 			group = &mld2q->mld2q_mca;
1175 		max_delay = mld2q->mld2q_mrc ? MLDV2_MRC(mld2q->mld2q_mrc) : 1;
1176 	}
1177 
1178 	if (!group)
1179 		goto out;
1180 
1181 	mp = br_mdb_ip6_get(mlock_dereference(br->mdb, br), group);
1182 	if (!mp)
1183 		goto out;
1184 
1185 	max_delay *= br->multicast_last_member_count;
1186 	if (mp->mglist &&
1187 	    (timer_pending(&mp->timer) ?
1188 	     time_after(mp->timer.expires, now + max_delay) :
1189 	     try_to_del_timer_sync(&mp->timer) >= 0))
1190 		mod_timer(&mp->timer, now + max_delay);
1191 
1192 	for (pp = &mp->ports;
1193 	     (p = mlock_dereference(*pp, br)) != NULL;
1194 	     pp = &p->next) {
1195 		if (timer_pending(&p->timer) ?
1196 		    time_after(p->timer.expires, now + max_delay) :
1197 		    try_to_del_timer_sync(&p->timer) >= 0)
1198 			mod_timer(&p->timer, now + max_delay);
1199 	}
1200 
1201 out:
1202 	spin_unlock(&br->multicast_lock);
1203 	return err;
1204 }
1205 #endif
1206 
1207 static void br_multicast_leave_group(struct net_bridge *br,
1208 				     struct net_bridge_port *port,
1209 				     struct br_ip *group)
1210 {
1211 	struct net_bridge_mdb_htable *mdb;
1212 	struct net_bridge_mdb_entry *mp;
1213 	struct net_bridge_port_group *p;
1214 	unsigned long now;
1215 	unsigned long time;
1216 
1217 	spin_lock(&br->multicast_lock);
1218 	if (!netif_running(br->dev) ||
1219 	    (port && port->state == BR_STATE_DISABLED) ||
1220 	    timer_pending(&br->multicast_querier_timer))
1221 		goto out;
1222 
1223 	mdb = mlock_dereference(br->mdb, br);
1224 	mp = br_mdb_ip_get(mdb, group);
1225 	if (!mp)
1226 		goto out;
1227 
1228 	now = jiffies;
1229 	time = now + br->multicast_last_member_count *
1230 		     br->multicast_last_member_interval;
1231 
1232 	if (!port) {
1233 		if (mp->mglist &&
1234 		    (timer_pending(&mp->timer) ?
1235 		     time_after(mp->timer.expires, time) :
1236 		     try_to_del_timer_sync(&mp->timer) >= 0)) {
1237 			mod_timer(&mp->timer, time);
1238 		}
1239 
1240 		goto out;
1241 	}
1242 
1243 	for (p = mlock_dereference(mp->ports, br);
1244 	     p != NULL;
1245 	     p = mlock_dereference(p->next, br)) {
1246 		if (p->port != port)
1247 			continue;
1248 
1249 		if (!hlist_unhashed(&p->mglist) &&
1250 		    (timer_pending(&p->timer) ?
1251 		     time_after(p->timer.expires, time) :
1252 		     try_to_del_timer_sync(&p->timer) >= 0)) {
1253 			mod_timer(&p->timer, time);
1254 		}
1255 
1256 		break;
1257 	}
1258 
1259 out:
1260 	spin_unlock(&br->multicast_lock);
1261 }
1262 
1263 static void br_ip4_multicast_leave_group(struct net_bridge *br,
1264 					 struct net_bridge_port *port,
1265 					 __be32 group)
1266 {
1267 	struct br_ip br_group;
1268 
1269 	if (ipv4_is_local_multicast(group))
1270 		return;
1271 
1272 	br_group.u.ip4 = group;
1273 	br_group.proto = htons(ETH_P_IP);
1274 
1275 	br_multicast_leave_group(br, port, &br_group);
1276 }
1277 
1278 #if IS_ENABLED(CONFIG_IPV6)
1279 static void br_ip6_multicast_leave_group(struct net_bridge *br,
1280 					 struct net_bridge_port *port,
1281 					 const struct in6_addr *group)
1282 {
1283 	struct br_ip br_group;
1284 
1285 	if (!ipv6_is_transient_multicast(group))
1286 		return;
1287 
1288 	br_group.u.ip6 = *group;
1289 	br_group.proto = htons(ETH_P_IPV6);
1290 
1291 	br_multicast_leave_group(br, port, &br_group);
1292 }
1293 #endif
1294 
1295 static int br_multicast_ipv4_rcv(struct net_bridge *br,
1296 				 struct net_bridge_port *port,
1297 				 struct sk_buff *skb)
1298 {
1299 	struct sk_buff *skb2 = skb;
1300 	const struct iphdr *iph;
1301 	struct igmphdr *ih;
1302 	unsigned int len;
1303 	unsigned int offset;
1304 	int err;
1305 
1306 	/* We treat OOM as packet loss for now. */
1307 	if (!pskb_may_pull(skb, sizeof(*iph)))
1308 		return -EINVAL;
1309 
1310 	iph = ip_hdr(skb);
1311 
1312 	if (iph->ihl < 5 || iph->version != 4)
1313 		return -EINVAL;
1314 
1315 	if (!pskb_may_pull(skb, ip_hdrlen(skb)))
1316 		return -EINVAL;
1317 
1318 	iph = ip_hdr(skb);
1319 
1320 	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1321 		return -EINVAL;
1322 
1323 	if (iph->protocol != IPPROTO_IGMP) {
1324 		if ((iph->daddr & IGMP_LOCAL_GROUP_MASK) != IGMP_LOCAL_GROUP)
1325 			BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
1326 		return 0;
1327 	}
1328 
1329 	len = ntohs(iph->tot_len);
1330 	if (skb->len < len || len < ip_hdrlen(skb))
1331 		return -EINVAL;
1332 
1333 	if (skb->len > len) {
1334 		skb2 = skb_clone(skb, GFP_ATOMIC);
1335 		if (!skb2)
1336 			return -ENOMEM;
1337 
1338 		err = pskb_trim_rcsum(skb2, len);
1339 		if (err)
1340 			goto err_out;
1341 	}
1342 
1343 	len -= ip_hdrlen(skb2);
1344 	offset = skb_network_offset(skb2) + ip_hdrlen(skb2);
1345 	__skb_pull(skb2, offset);
1346 	skb_reset_transport_header(skb2);
1347 
1348 	err = -EINVAL;
1349 	if (!pskb_may_pull(skb2, sizeof(*ih)))
1350 		goto out;
1351 
1352 	switch (skb2->ip_summed) {
1353 	case CHECKSUM_COMPLETE:
1354 		if (!csum_fold(skb2->csum))
1355 			break;
1356 		/* fall through */
1357 	case CHECKSUM_NONE:
1358 		skb2->csum = 0;
1359 		if (skb_checksum_complete(skb2))
1360 			goto out;
1361 	}
1362 
1363 	err = 0;
1364 
1365 	BR_INPUT_SKB_CB(skb)->igmp = 1;
1366 	ih = igmp_hdr(skb2);
1367 
1368 	switch (ih->type) {
1369 	case IGMP_HOST_MEMBERSHIP_REPORT:
1370 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
1371 		BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
1372 		err = br_ip4_multicast_add_group(br, port, ih->group);
1373 		break;
1374 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
1375 		err = br_ip4_multicast_igmp3_report(br, port, skb2);
1376 		break;
1377 	case IGMP_HOST_MEMBERSHIP_QUERY:
1378 		err = br_ip4_multicast_query(br, port, skb2);
1379 		break;
1380 	case IGMP_HOST_LEAVE_MESSAGE:
1381 		br_ip4_multicast_leave_group(br, port, ih->group);
1382 		break;
1383 	}
1384 
1385 out:
1386 	__skb_push(skb2, offset);
1387 err_out:
1388 	if (skb2 != skb)
1389 		kfree_skb(skb2);
1390 	return err;
1391 }
1392 
1393 #if IS_ENABLED(CONFIG_IPV6)
1394 static int br_multicast_ipv6_rcv(struct net_bridge *br,
1395 				 struct net_bridge_port *port,
1396 				 struct sk_buff *skb)
1397 {
1398 	struct sk_buff *skb2;
1399 	const struct ipv6hdr *ip6h;
1400 	u8 icmp6_type;
1401 	u8 nexthdr;
1402 	__be16 frag_off;
1403 	unsigned int len;
1404 	int offset;
1405 	int err;
1406 
1407 	if (!pskb_may_pull(skb, sizeof(*ip6h)))
1408 		return -EINVAL;
1409 
1410 	ip6h = ipv6_hdr(skb);
1411 
1412 	/*
1413 	 * We're interested in MLD messages only.
1414 	 *  - Version is 6
1415 	 *  - MLD has always Router Alert hop-by-hop option
1416 	 *  - But we do not support jumbrograms.
1417 	 */
1418 	if (ip6h->version != 6 ||
1419 	    ip6h->nexthdr != IPPROTO_HOPOPTS ||
1420 	    ip6h->payload_len == 0)
1421 		return 0;
1422 
1423 	len = ntohs(ip6h->payload_len) + sizeof(*ip6h);
1424 	if (skb->len < len)
1425 		return -EINVAL;
1426 
1427 	nexthdr = ip6h->nexthdr;
1428 	offset = ipv6_skip_exthdr(skb, sizeof(*ip6h), &nexthdr, &frag_off);
1429 
1430 	if (offset < 0 || nexthdr != IPPROTO_ICMPV6)
1431 		return 0;
1432 
1433 	/* Okay, we found ICMPv6 header */
1434 	skb2 = skb_clone(skb, GFP_ATOMIC);
1435 	if (!skb2)
1436 		return -ENOMEM;
1437 
1438 	err = -EINVAL;
1439 	if (!pskb_may_pull(skb2, offset + sizeof(struct icmp6hdr)))
1440 		goto out;
1441 
1442 	len -= offset - skb_network_offset(skb2);
1443 
1444 	__skb_pull(skb2, offset);
1445 	skb_reset_transport_header(skb2);
1446 	skb_postpull_rcsum(skb2, skb_network_header(skb2),
1447 			   skb_network_header_len(skb2));
1448 
1449 	icmp6_type = icmp6_hdr(skb2)->icmp6_type;
1450 
1451 	switch (icmp6_type) {
1452 	case ICMPV6_MGM_QUERY:
1453 	case ICMPV6_MGM_REPORT:
1454 	case ICMPV6_MGM_REDUCTION:
1455 	case ICMPV6_MLD2_REPORT:
1456 		break;
1457 	default:
1458 		err = 0;
1459 		goto out;
1460 	}
1461 
1462 	/* Okay, we found MLD message. Check further. */
1463 	if (skb2->len > len) {
1464 		err = pskb_trim_rcsum(skb2, len);
1465 		if (err)
1466 			goto out;
1467 		err = -EINVAL;
1468 	}
1469 
1470 	ip6h = ipv6_hdr(skb2);
1471 
1472 	switch (skb2->ip_summed) {
1473 	case CHECKSUM_COMPLETE:
1474 		if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, skb2->len,
1475 					IPPROTO_ICMPV6, skb2->csum))
1476 			break;
1477 		/*FALLTHROUGH*/
1478 	case CHECKSUM_NONE:
1479 		skb2->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr,
1480 							&ip6h->daddr,
1481 							skb2->len,
1482 							IPPROTO_ICMPV6, 0));
1483 		if (__skb_checksum_complete(skb2))
1484 			goto out;
1485 	}
1486 
1487 	err = 0;
1488 
1489 	BR_INPUT_SKB_CB(skb)->igmp = 1;
1490 
1491 	switch (icmp6_type) {
1492 	case ICMPV6_MGM_REPORT:
1493 	    {
1494 		struct mld_msg *mld;
1495 		if (!pskb_may_pull(skb2, sizeof(*mld))) {
1496 			err = -EINVAL;
1497 			goto out;
1498 		}
1499 		mld = (struct mld_msg *)skb_transport_header(skb2);
1500 		BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
1501 		err = br_ip6_multicast_add_group(br, port, &mld->mld_mca);
1502 		break;
1503 	    }
1504 	case ICMPV6_MLD2_REPORT:
1505 		err = br_ip6_multicast_mld2_report(br, port, skb2);
1506 		break;
1507 	case ICMPV6_MGM_QUERY:
1508 		err = br_ip6_multicast_query(br, port, skb2);
1509 		break;
1510 	case ICMPV6_MGM_REDUCTION:
1511 	    {
1512 		struct mld_msg *mld;
1513 		if (!pskb_may_pull(skb2, sizeof(*mld))) {
1514 			err = -EINVAL;
1515 			goto out;
1516 		}
1517 		mld = (struct mld_msg *)skb_transport_header(skb2);
1518 		br_ip6_multicast_leave_group(br, port, &mld->mld_mca);
1519 	    }
1520 	}
1521 
1522 out:
1523 	kfree_skb(skb2);
1524 	return err;
1525 }
1526 #endif
1527 
1528 int br_multicast_rcv(struct net_bridge *br, struct net_bridge_port *port,
1529 		     struct sk_buff *skb)
1530 {
1531 	BR_INPUT_SKB_CB(skb)->igmp = 0;
1532 	BR_INPUT_SKB_CB(skb)->mrouters_only = 0;
1533 
1534 	if (br->multicast_disabled)
1535 		return 0;
1536 
1537 	switch (skb->protocol) {
1538 	case htons(ETH_P_IP):
1539 		return br_multicast_ipv4_rcv(br, port, skb);
1540 #if IS_ENABLED(CONFIG_IPV6)
1541 	case htons(ETH_P_IPV6):
1542 		return br_multicast_ipv6_rcv(br, port, skb);
1543 #endif
1544 	}
1545 
1546 	return 0;
1547 }
1548 
1549 static void br_multicast_query_expired(unsigned long data)
1550 {
1551 	struct net_bridge *br = (void *)data;
1552 
1553 	spin_lock(&br->multicast_lock);
1554 	if (br->multicast_startup_queries_sent <
1555 	    br->multicast_startup_query_count)
1556 		br->multicast_startup_queries_sent++;
1557 
1558 	br_multicast_send_query(br, NULL, br->multicast_startup_queries_sent);
1559 
1560 	spin_unlock(&br->multicast_lock);
1561 }
1562 
1563 void br_multicast_init(struct net_bridge *br)
1564 {
1565 	br->hash_elasticity = 4;
1566 	br->hash_max = 512;
1567 
1568 	br->multicast_router = 1;
1569 	br->multicast_querier = 0;
1570 	br->multicast_last_member_count = 2;
1571 	br->multicast_startup_query_count = 2;
1572 
1573 	br->multicast_last_member_interval = HZ;
1574 	br->multicast_query_response_interval = 10 * HZ;
1575 	br->multicast_startup_query_interval = 125 * HZ / 4;
1576 	br->multicast_query_interval = 125 * HZ;
1577 	br->multicast_querier_interval = 255 * HZ;
1578 	br->multicast_membership_interval = 260 * HZ;
1579 
1580 	spin_lock_init(&br->multicast_lock);
1581 	setup_timer(&br->multicast_router_timer,
1582 		    br_multicast_local_router_expired, 0);
1583 	setup_timer(&br->multicast_querier_timer,
1584 		    br_multicast_querier_expired, (unsigned long)br);
1585 	setup_timer(&br->multicast_query_timer, br_multicast_query_expired,
1586 		    (unsigned long)br);
1587 }
1588 
1589 void br_multicast_open(struct net_bridge *br)
1590 {
1591 	br->multicast_startup_queries_sent = 0;
1592 
1593 	if (br->multicast_disabled)
1594 		return;
1595 
1596 	mod_timer(&br->multicast_query_timer, jiffies);
1597 }
1598 
1599 void br_multicast_stop(struct net_bridge *br)
1600 {
1601 	struct net_bridge_mdb_htable *mdb;
1602 	struct net_bridge_mdb_entry *mp;
1603 	struct hlist_node *p, *n;
1604 	u32 ver;
1605 	int i;
1606 
1607 	del_timer_sync(&br->multicast_router_timer);
1608 	del_timer_sync(&br->multicast_querier_timer);
1609 	del_timer_sync(&br->multicast_query_timer);
1610 
1611 	spin_lock_bh(&br->multicast_lock);
1612 	mdb = mlock_dereference(br->mdb, br);
1613 	if (!mdb)
1614 		goto out;
1615 
1616 	br->mdb = NULL;
1617 
1618 	ver = mdb->ver;
1619 	for (i = 0; i < mdb->max; i++) {
1620 		hlist_for_each_entry_safe(mp, p, n, &mdb->mhash[i],
1621 					  hlist[ver]) {
1622 			del_timer(&mp->timer);
1623 			call_rcu_bh(&mp->rcu, br_multicast_free_group);
1624 		}
1625 	}
1626 
1627 	if (mdb->old) {
1628 		spin_unlock_bh(&br->multicast_lock);
1629 		rcu_barrier_bh();
1630 		spin_lock_bh(&br->multicast_lock);
1631 		WARN_ON(mdb->old);
1632 	}
1633 
1634 	mdb->old = mdb;
1635 	call_rcu_bh(&mdb->rcu, br_mdb_free);
1636 
1637 out:
1638 	spin_unlock_bh(&br->multicast_lock);
1639 }
1640 
1641 int br_multicast_set_router(struct net_bridge *br, unsigned long val)
1642 {
1643 	int err = -ENOENT;
1644 
1645 	spin_lock_bh(&br->multicast_lock);
1646 	if (!netif_running(br->dev))
1647 		goto unlock;
1648 
1649 	switch (val) {
1650 	case 0:
1651 	case 2:
1652 		del_timer(&br->multicast_router_timer);
1653 		/* fall through */
1654 	case 1:
1655 		br->multicast_router = val;
1656 		err = 0;
1657 		break;
1658 
1659 	default:
1660 		err = -EINVAL;
1661 		break;
1662 	}
1663 
1664 unlock:
1665 	spin_unlock_bh(&br->multicast_lock);
1666 
1667 	return err;
1668 }
1669 
1670 int br_multicast_set_port_router(struct net_bridge_port *p, unsigned long val)
1671 {
1672 	struct net_bridge *br = p->br;
1673 	int err = -ENOENT;
1674 
1675 	spin_lock(&br->multicast_lock);
1676 	if (!netif_running(br->dev) || p->state == BR_STATE_DISABLED)
1677 		goto unlock;
1678 
1679 	switch (val) {
1680 	case 0:
1681 	case 1:
1682 	case 2:
1683 		p->multicast_router = val;
1684 		err = 0;
1685 
1686 		if (val < 2 && !hlist_unhashed(&p->rlist))
1687 			hlist_del_init_rcu(&p->rlist);
1688 
1689 		if (val == 1)
1690 			break;
1691 
1692 		del_timer(&p->multicast_router_timer);
1693 
1694 		if (val == 0)
1695 			break;
1696 
1697 		br_multicast_add_router(br, p);
1698 		break;
1699 
1700 	default:
1701 		err = -EINVAL;
1702 		break;
1703 	}
1704 
1705 unlock:
1706 	spin_unlock(&br->multicast_lock);
1707 
1708 	return err;
1709 }
1710 
1711 static void br_multicast_start_querier(struct net_bridge *br)
1712 {
1713 	struct net_bridge_port *port;
1714 
1715 	br_multicast_open(br);
1716 
1717 	list_for_each_entry(port, &br->port_list, list) {
1718 		if (port->state == BR_STATE_DISABLED ||
1719 		    port->state == BR_STATE_BLOCKING)
1720 			continue;
1721 
1722 		__br_multicast_enable_port(port);
1723 	}
1724 }
1725 
1726 int br_multicast_toggle(struct net_bridge *br, unsigned long val)
1727 {
1728 	int err = 0;
1729 	struct net_bridge_mdb_htable *mdb;
1730 
1731 	spin_lock_bh(&br->multicast_lock);
1732 	if (br->multicast_disabled == !val)
1733 		goto unlock;
1734 
1735 	br->multicast_disabled = !val;
1736 	if (br->multicast_disabled)
1737 		goto unlock;
1738 
1739 	if (!netif_running(br->dev))
1740 		goto unlock;
1741 
1742 	mdb = mlock_dereference(br->mdb, br);
1743 	if (mdb) {
1744 		if (mdb->old) {
1745 			err = -EEXIST;
1746 rollback:
1747 			br->multicast_disabled = !!val;
1748 			goto unlock;
1749 		}
1750 
1751 		err = br_mdb_rehash(&br->mdb, mdb->max,
1752 				    br->hash_elasticity);
1753 		if (err)
1754 			goto rollback;
1755 	}
1756 
1757 	br_multicast_start_querier(br);
1758 
1759 unlock:
1760 	spin_unlock_bh(&br->multicast_lock);
1761 
1762 	return err;
1763 }
1764 
1765 int br_multicast_set_querier(struct net_bridge *br, unsigned long val)
1766 {
1767 	val = !!val;
1768 
1769 	spin_lock_bh(&br->multicast_lock);
1770 	if (br->multicast_querier == val)
1771 		goto unlock;
1772 
1773 	br->multicast_querier = val;
1774 	if (val)
1775 		br_multicast_start_querier(br);
1776 
1777 unlock:
1778 	spin_unlock_bh(&br->multicast_lock);
1779 
1780 	return 0;
1781 }
1782 
1783 int br_multicast_set_hash_max(struct net_bridge *br, unsigned long val)
1784 {
1785 	int err = -ENOENT;
1786 	u32 old;
1787 	struct net_bridge_mdb_htable *mdb;
1788 
1789 	spin_lock(&br->multicast_lock);
1790 	if (!netif_running(br->dev))
1791 		goto unlock;
1792 
1793 	err = -EINVAL;
1794 	if (!is_power_of_2(val))
1795 		goto unlock;
1796 
1797 	mdb = mlock_dereference(br->mdb, br);
1798 	if (mdb && val < mdb->size)
1799 		goto unlock;
1800 
1801 	err = 0;
1802 
1803 	old = br->hash_max;
1804 	br->hash_max = val;
1805 
1806 	if (mdb) {
1807 		if (mdb->old) {
1808 			err = -EEXIST;
1809 rollback:
1810 			br->hash_max = old;
1811 			goto unlock;
1812 		}
1813 
1814 		err = br_mdb_rehash(&br->mdb, br->hash_max,
1815 				    br->hash_elasticity);
1816 		if (err)
1817 			goto rollback;
1818 	}
1819 
1820 unlock:
1821 	spin_unlock(&br->multicast_lock);
1822 
1823 	return err;
1824 }
1825