xref: /linux/net/bridge/br_multicast.c (revision e190bfe56841551b1ad5abb42ebd0c4798cc8c01)
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 defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
37 static inline int ipv6_is_local_multicast(const struct in6_addr *addr)
38 {
39 	if (ipv6_addr_is_multicast(addr) &&
40 	    IPV6_ADDR_MC_SCOPE(addr) <= IPV6_ADDR_SCOPE_LINKLOCAL)
41 		return 1;
42 	return 0;
43 }
44 #endif
45 
46 static inline int br_ip_equal(const struct br_ip *a, const struct br_ip *b)
47 {
48 	if (a->proto != b->proto)
49 		return 0;
50 	switch (a->proto) {
51 	case htons(ETH_P_IP):
52 		return a->u.ip4 == b->u.ip4;
53 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
54 	case htons(ETH_P_IPV6):
55 		return ipv6_addr_equal(&a->u.ip6, &b->u.ip6);
56 #endif
57 	}
58 	return 0;
59 }
60 
61 static inline int __br_ip4_hash(struct net_bridge_mdb_htable *mdb, __be32 ip)
62 {
63 	return jhash_1word(mdb->secret, (__force u32)ip) & (mdb->max - 1);
64 }
65 
66 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
67 static inline int __br_ip6_hash(struct net_bridge_mdb_htable *mdb,
68 				const struct in6_addr *ip)
69 {
70 	return jhash2((__force u32 *)ip->s6_addr32, 4, mdb->secret) & (mdb->max - 1);
71 }
72 #endif
73 
74 static inline int br_ip_hash(struct net_bridge_mdb_htable *mdb,
75 			     struct br_ip *ip)
76 {
77 	switch (ip->proto) {
78 	case htons(ETH_P_IP):
79 		return __br_ip4_hash(mdb, ip->u.ip4);
80 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
81 	case htons(ETH_P_IPV6):
82 		return __br_ip6_hash(mdb, &ip->u.ip6);
83 #endif
84 	}
85 	return 0;
86 }
87 
88 static struct net_bridge_mdb_entry *__br_mdb_ip_get(
89 	struct net_bridge_mdb_htable *mdb, struct br_ip *dst, int hash)
90 {
91 	struct net_bridge_mdb_entry *mp;
92 	struct hlist_node *p;
93 
94 	hlist_for_each_entry_rcu(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) {
95 		if (br_ip_equal(&mp->addr, dst))
96 			return mp;
97 	}
98 
99 	return NULL;
100 }
101 
102 static struct net_bridge_mdb_entry *br_mdb_ip4_get(
103 	struct net_bridge_mdb_htable *mdb, __be32 dst)
104 {
105 	struct br_ip br_dst;
106 
107 	br_dst.u.ip4 = dst;
108 	br_dst.proto = htons(ETH_P_IP);
109 
110 	return __br_mdb_ip_get(mdb, &br_dst, __br_ip4_hash(mdb, dst));
111 }
112 
113 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
114 static struct net_bridge_mdb_entry *br_mdb_ip6_get(
115 	struct net_bridge_mdb_htable *mdb, const struct in6_addr *dst)
116 {
117 	struct br_ip br_dst;
118 
119 	ipv6_addr_copy(&br_dst.u.ip6, dst);
120 	br_dst.proto = htons(ETH_P_IPV6);
121 
122 	return __br_mdb_ip_get(mdb, &br_dst, __br_ip6_hash(mdb, dst));
123 }
124 #endif
125 
126 static struct net_bridge_mdb_entry *br_mdb_ip_get(
127 	struct net_bridge_mdb_htable *mdb, struct br_ip *dst)
128 {
129 	return __br_mdb_ip_get(mdb, dst, br_ip_hash(mdb, dst));
130 }
131 
132 struct net_bridge_mdb_entry *br_mdb_get(struct net_bridge *br,
133 					struct sk_buff *skb)
134 {
135 	struct net_bridge_mdb_htable *mdb = br->mdb;
136 	struct br_ip ip;
137 
138 	if (!mdb || br->multicast_disabled)
139 		return NULL;
140 
141 	if (BR_INPUT_SKB_CB(skb)->igmp)
142 		return NULL;
143 
144 	ip.proto = skb->protocol;
145 
146 	switch (skb->protocol) {
147 	case htons(ETH_P_IP):
148 		ip.u.ip4 = ip_hdr(skb)->daddr;
149 		break;
150 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
151 	case htons(ETH_P_IPV6):
152 		ipv6_addr_copy(&ip.u.ip6, &ipv6_hdr(skb)->daddr);
153 		break;
154 #endif
155 	default:
156 		return NULL;
157 	}
158 
159 	return br_mdb_ip_get(mdb, &ip);
160 }
161 
162 static void br_mdb_free(struct rcu_head *head)
163 {
164 	struct net_bridge_mdb_htable *mdb =
165 		container_of(head, struct net_bridge_mdb_htable, rcu);
166 	struct net_bridge_mdb_htable *old = mdb->old;
167 
168 	mdb->old = NULL;
169 	kfree(old->mhash);
170 	kfree(old);
171 }
172 
173 static int br_mdb_copy(struct net_bridge_mdb_htable *new,
174 		       struct net_bridge_mdb_htable *old,
175 		       int elasticity)
176 {
177 	struct net_bridge_mdb_entry *mp;
178 	struct hlist_node *p;
179 	int maxlen;
180 	int len;
181 	int i;
182 
183 	for (i = 0; i < old->max; i++)
184 		hlist_for_each_entry(mp, p, &old->mhash[i], hlist[old->ver])
185 			hlist_add_head(&mp->hlist[new->ver],
186 				       &new->mhash[br_ip_hash(new, &mp->addr)]);
187 
188 	if (!elasticity)
189 		return 0;
190 
191 	maxlen = 0;
192 	for (i = 0; i < new->max; i++) {
193 		len = 0;
194 		hlist_for_each_entry(mp, p, &new->mhash[i], hlist[new->ver])
195 			len++;
196 		if (len > maxlen)
197 			maxlen = len;
198 	}
199 
200 	return maxlen > elasticity ? -EINVAL : 0;
201 }
202 
203 static void br_multicast_free_pg(struct rcu_head *head)
204 {
205 	struct net_bridge_port_group *p =
206 		container_of(head, struct net_bridge_port_group, rcu);
207 
208 	kfree(p);
209 }
210 
211 static void br_multicast_free_group(struct rcu_head *head)
212 {
213 	struct net_bridge_mdb_entry *mp =
214 		container_of(head, struct net_bridge_mdb_entry, rcu);
215 
216 	kfree(mp);
217 }
218 
219 static void br_multicast_group_expired(unsigned long data)
220 {
221 	struct net_bridge_mdb_entry *mp = (void *)data;
222 	struct net_bridge *br = mp->br;
223 	struct net_bridge_mdb_htable *mdb;
224 
225 	spin_lock(&br->multicast_lock);
226 	if (!netif_running(br->dev) || timer_pending(&mp->timer))
227 		goto out;
228 
229 	if (!hlist_unhashed(&mp->mglist))
230 		hlist_del_init(&mp->mglist);
231 
232 	if (mp->ports)
233 		goto out;
234 
235 	mdb = br->mdb;
236 	hlist_del_rcu(&mp->hlist[mdb->ver]);
237 	mdb->size--;
238 
239 	del_timer(&mp->query_timer);
240 	call_rcu_bh(&mp->rcu, br_multicast_free_group);
241 
242 out:
243 	spin_unlock(&br->multicast_lock);
244 }
245 
246 static void br_multicast_del_pg(struct net_bridge *br,
247 				struct net_bridge_port_group *pg)
248 {
249 	struct net_bridge_mdb_htable *mdb = br->mdb;
250 	struct net_bridge_mdb_entry *mp;
251 	struct net_bridge_port_group *p;
252 	struct net_bridge_port_group **pp;
253 
254 	mp = br_mdb_ip_get(mdb, &pg->addr);
255 	if (WARN_ON(!mp))
256 		return;
257 
258 	for (pp = &mp->ports; (p = *pp); pp = &p->next) {
259 		if (p != pg)
260 			continue;
261 
262 		rcu_assign_pointer(*pp, p->next);
263 		hlist_del_init(&p->mglist);
264 		del_timer(&p->timer);
265 		del_timer(&p->query_timer);
266 		call_rcu_bh(&p->rcu, br_multicast_free_pg);
267 
268 		if (!mp->ports && hlist_unhashed(&mp->mglist) &&
269 		    netif_running(br->dev))
270 			mod_timer(&mp->timer, jiffies);
271 
272 		return;
273 	}
274 
275 	WARN_ON(1);
276 }
277 
278 static void br_multicast_port_group_expired(unsigned long data)
279 {
280 	struct net_bridge_port_group *pg = (void *)data;
281 	struct net_bridge *br = pg->port->br;
282 
283 	spin_lock(&br->multicast_lock);
284 	if (!netif_running(br->dev) || timer_pending(&pg->timer) ||
285 	    hlist_unhashed(&pg->mglist))
286 		goto out;
287 
288 	br_multicast_del_pg(br, pg);
289 
290 out:
291 	spin_unlock(&br->multicast_lock);
292 }
293 
294 static int br_mdb_rehash(struct net_bridge_mdb_htable **mdbp, int max,
295 			 int elasticity)
296 {
297 	struct net_bridge_mdb_htable *old = *mdbp;
298 	struct net_bridge_mdb_htable *mdb;
299 	int err;
300 
301 	mdb = kmalloc(sizeof(*mdb), GFP_ATOMIC);
302 	if (!mdb)
303 		return -ENOMEM;
304 
305 	mdb->max = max;
306 	mdb->old = old;
307 
308 	mdb->mhash = kzalloc(max * sizeof(*mdb->mhash), GFP_ATOMIC);
309 	if (!mdb->mhash) {
310 		kfree(mdb);
311 		return -ENOMEM;
312 	}
313 
314 	mdb->size = old ? old->size : 0;
315 	mdb->ver = old ? old->ver ^ 1 : 0;
316 
317 	if (!old || elasticity)
318 		get_random_bytes(&mdb->secret, sizeof(mdb->secret));
319 	else
320 		mdb->secret = old->secret;
321 
322 	if (!old)
323 		goto out;
324 
325 	err = br_mdb_copy(mdb, old, elasticity);
326 	if (err) {
327 		kfree(mdb->mhash);
328 		kfree(mdb);
329 		return err;
330 	}
331 
332 	call_rcu_bh(&mdb->rcu, br_mdb_free);
333 
334 out:
335 	rcu_assign_pointer(*mdbp, mdb);
336 
337 	return 0;
338 }
339 
340 static struct sk_buff *br_ip4_multicast_alloc_query(struct net_bridge *br,
341 						    __be32 group)
342 {
343 	struct sk_buff *skb;
344 	struct igmphdr *ih;
345 	struct ethhdr *eth;
346 	struct iphdr *iph;
347 
348 	skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*iph) +
349 						 sizeof(*ih) + 4);
350 	if (!skb)
351 		goto out;
352 
353 	skb->protocol = htons(ETH_P_IP);
354 
355 	skb_reset_mac_header(skb);
356 	eth = eth_hdr(skb);
357 
358 	memcpy(eth->h_source, br->dev->dev_addr, 6);
359 	eth->h_dest[0] = 1;
360 	eth->h_dest[1] = 0;
361 	eth->h_dest[2] = 0x5e;
362 	eth->h_dest[3] = 0;
363 	eth->h_dest[4] = 0;
364 	eth->h_dest[5] = 1;
365 	eth->h_proto = htons(ETH_P_IP);
366 	skb_put(skb, sizeof(*eth));
367 
368 	skb_set_network_header(skb, skb->len);
369 	iph = ip_hdr(skb);
370 
371 	iph->version = 4;
372 	iph->ihl = 6;
373 	iph->tos = 0xc0;
374 	iph->tot_len = htons(sizeof(*iph) + sizeof(*ih) + 4);
375 	iph->id = 0;
376 	iph->frag_off = htons(IP_DF);
377 	iph->ttl = 1;
378 	iph->protocol = IPPROTO_IGMP;
379 	iph->saddr = 0;
380 	iph->daddr = htonl(INADDR_ALLHOSTS_GROUP);
381 	((u8 *)&iph[1])[0] = IPOPT_RA;
382 	((u8 *)&iph[1])[1] = 4;
383 	((u8 *)&iph[1])[2] = 0;
384 	((u8 *)&iph[1])[3] = 0;
385 	ip_send_check(iph);
386 	skb_put(skb, 24);
387 
388 	skb_set_transport_header(skb, skb->len);
389 	ih = igmp_hdr(skb);
390 	ih->type = IGMP_HOST_MEMBERSHIP_QUERY;
391 	ih->code = (group ? br->multicast_last_member_interval :
392 			    br->multicast_query_response_interval) /
393 		   (HZ / IGMP_TIMER_SCALE);
394 	ih->group = group;
395 	ih->csum = 0;
396 	ih->csum = ip_compute_csum((void *)ih, sizeof(struct igmphdr));
397 	skb_put(skb, sizeof(*ih));
398 
399 	__skb_pull(skb, sizeof(*eth));
400 
401 out:
402 	return skb;
403 }
404 
405 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
406 static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
407 						    struct in6_addr *group)
408 {
409 	struct sk_buff *skb;
410 	struct ipv6hdr *ip6h;
411 	struct mld_msg *mldq;
412 	struct ethhdr *eth;
413 	u8 *hopopt;
414 	unsigned long interval;
415 
416 	skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*ip6h) +
417 						 8 + sizeof(*mldq));
418 	if (!skb)
419 		goto out;
420 
421 	skb->protocol = htons(ETH_P_IPV6);
422 
423 	/* Ethernet header */
424 	skb_reset_mac_header(skb);
425 	eth = eth_hdr(skb);
426 
427 	memcpy(eth->h_source, br->dev->dev_addr, 6);
428 	ipv6_eth_mc_map(group, eth->h_dest);
429 	eth->h_proto = htons(ETH_P_IPV6);
430 	skb_put(skb, sizeof(*eth));
431 
432 	/* IPv6 header + HbH option */
433 	skb_set_network_header(skb, skb->len);
434 	ip6h = ipv6_hdr(skb);
435 
436 	*(__force __be32 *)ip6h = htonl(0x60000000);
437 	ip6h->payload_len = 8 + sizeof(*mldq);
438 	ip6h->nexthdr = IPPROTO_HOPOPTS;
439 	ip6h->hop_limit = 1;
440 	ipv6_addr_set(&ip6h->saddr, 0, 0, 0, 0);
441 	ipv6_addr_set(&ip6h->daddr, htonl(0xff020000), 0, 0, htonl(1));
442 
443 	hopopt = (u8 *)(ip6h + 1);
444 	hopopt[0] = IPPROTO_ICMPV6;		/* next hdr */
445 	hopopt[1] = 0;				/* length of HbH */
446 	hopopt[2] = IPV6_TLV_ROUTERALERT;	/* Router Alert */
447 	hopopt[3] = 2;				/* Length of RA Option */
448 	hopopt[4] = 0;				/* Type = 0x0000 (MLD) */
449 	hopopt[5] = 0;
450 	hopopt[6] = IPV6_TLV_PAD0;		/* Pad0 */
451 	hopopt[7] = IPV6_TLV_PAD0;		/* Pad0 */
452 
453 	skb_put(skb, sizeof(*ip6h) + 8);
454 
455 	/* ICMPv6 */
456 	skb_set_transport_header(skb, skb->len);
457 	mldq = (struct mld_msg *) icmp6_hdr(skb);
458 
459 	interval = ipv6_addr_any(group) ? br->multicast_last_member_interval :
460 					  br->multicast_query_response_interval;
461 
462 	mldq->mld_type = ICMPV6_MGM_QUERY;
463 	mldq->mld_code = 0;
464 	mldq->mld_cksum = 0;
465 	mldq->mld_maxdelay = htons((u16)jiffies_to_msecs(interval));
466 	mldq->mld_reserved = 0;
467 	ipv6_addr_copy(&mldq->mld_mca, group);
468 
469 	/* checksum */
470 	mldq->mld_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
471 					  sizeof(*mldq), IPPROTO_ICMPV6,
472 					  csum_partial(mldq,
473 						       sizeof(*mldq), 0));
474 	skb_put(skb, sizeof(*mldq));
475 
476 	__skb_pull(skb, sizeof(*eth));
477 
478 out:
479 	return skb;
480 }
481 #endif
482 
483 static struct sk_buff *br_multicast_alloc_query(struct net_bridge *br,
484 						struct br_ip *addr)
485 {
486 	switch (addr->proto) {
487 	case htons(ETH_P_IP):
488 		return br_ip4_multicast_alloc_query(br, addr->u.ip4);
489 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
490 	case htons(ETH_P_IPV6):
491 		return br_ip6_multicast_alloc_query(br, &addr->u.ip6);
492 #endif
493 	}
494 	return NULL;
495 }
496 
497 static void br_multicast_send_group_query(struct net_bridge_mdb_entry *mp)
498 {
499 	struct net_bridge *br = mp->br;
500 	struct sk_buff *skb;
501 
502 	skb = br_multicast_alloc_query(br, &mp->addr);
503 	if (!skb)
504 		goto timer;
505 
506 	netif_rx(skb);
507 
508 timer:
509 	if (++mp->queries_sent < br->multicast_last_member_count)
510 		mod_timer(&mp->query_timer,
511 			  jiffies + br->multicast_last_member_interval);
512 }
513 
514 static void br_multicast_group_query_expired(unsigned long data)
515 {
516 	struct net_bridge_mdb_entry *mp = (void *)data;
517 	struct net_bridge *br = mp->br;
518 
519 	spin_lock(&br->multicast_lock);
520 	if (!netif_running(br->dev) || hlist_unhashed(&mp->mglist) ||
521 	    mp->queries_sent >= br->multicast_last_member_count)
522 		goto out;
523 
524 	br_multicast_send_group_query(mp);
525 
526 out:
527 	spin_unlock(&br->multicast_lock);
528 }
529 
530 static void br_multicast_send_port_group_query(struct net_bridge_port_group *pg)
531 {
532 	struct net_bridge_port *port = pg->port;
533 	struct net_bridge *br = port->br;
534 	struct sk_buff *skb;
535 
536 	skb = br_multicast_alloc_query(br, &pg->addr);
537 	if (!skb)
538 		goto timer;
539 
540 	br_deliver(port, skb);
541 
542 timer:
543 	if (++pg->queries_sent < br->multicast_last_member_count)
544 		mod_timer(&pg->query_timer,
545 			  jiffies + br->multicast_last_member_interval);
546 }
547 
548 static void br_multicast_port_group_query_expired(unsigned long data)
549 {
550 	struct net_bridge_port_group *pg = (void *)data;
551 	struct net_bridge_port *port = pg->port;
552 	struct net_bridge *br = port->br;
553 
554 	spin_lock(&br->multicast_lock);
555 	if (!netif_running(br->dev) || hlist_unhashed(&pg->mglist) ||
556 	    pg->queries_sent >= br->multicast_last_member_count)
557 		goto out;
558 
559 	br_multicast_send_port_group_query(pg);
560 
561 out:
562 	spin_unlock(&br->multicast_lock);
563 }
564 
565 static struct net_bridge_mdb_entry *br_multicast_get_group(
566 	struct net_bridge *br, struct net_bridge_port *port,
567 	struct br_ip *group, int hash)
568 {
569 	struct net_bridge_mdb_htable *mdb = br->mdb;
570 	struct net_bridge_mdb_entry *mp;
571 	struct hlist_node *p;
572 	unsigned count = 0;
573 	unsigned max;
574 	int elasticity;
575 	int err;
576 
577 	hlist_for_each_entry(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) {
578 		count++;
579 		if (unlikely(br_ip_equal(group, &mp->addr)))
580 			return mp;
581 	}
582 
583 	elasticity = 0;
584 	max = mdb->max;
585 
586 	if (unlikely(count > br->hash_elasticity && count)) {
587 		if (net_ratelimit())
588 			br_info(br, "Multicast hash table "
589 				"chain limit reached: %s\n",
590 				port ? port->dev->name : br->dev->name);
591 
592 		elasticity = br->hash_elasticity;
593 	}
594 
595 	if (mdb->size >= max) {
596 		max *= 2;
597 		if (unlikely(max >= br->hash_max)) {
598 			br_warn(br, "Multicast hash table maximum "
599 				"reached, disabling snooping: %s, %d\n",
600 				port ? port->dev->name : br->dev->name, max);
601 			err = -E2BIG;
602 disable:
603 			br->multicast_disabled = 1;
604 			goto err;
605 		}
606 	}
607 
608 	if (max > mdb->max || elasticity) {
609 		if (mdb->old) {
610 			if (net_ratelimit())
611 				br_info(br, "Multicast hash table "
612 					"on fire: %s\n",
613 					port ? port->dev->name : br->dev->name);
614 			err = -EEXIST;
615 			goto err;
616 		}
617 
618 		err = br_mdb_rehash(&br->mdb, max, elasticity);
619 		if (err) {
620 			br_warn(br, "Cannot rehash multicast "
621 				"hash table, disabling snooping: %s, %d, %d\n",
622 				port ? port->dev->name : br->dev->name,
623 				mdb->size, err);
624 			goto disable;
625 		}
626 
627 		err = -EAGAIN;
628 		goto err;
629 	}
630 
631 	return NULL;
632 
633 err:
634 	mp = ERR_PTR(err);
635 	return mp;
636 }
637 
638 static struct net_bridge_mdb_entry *br_multicast_new_group(
639 	struct net_bridge *br, struct net_bridge_port *port,
640 	struct br_ip *group)
641 {
642 	struct net_bridge_mdb_htable *mdb = br->mdb;
643 	struct net_bridge_mdb_entry *mp;
644 	int hash;
645 
646 	if (!mdb) {
647 		if (br_mdb_rehash(&br->mdb, BR_HASH_SIZE, 0))
648 			return NULL;
649 		goto rehash;
650 	}
651 
652 	hash = br_ip_hash(mdb, group);
653 	mp = br_multicast_get_group(br, port, group, hash);
654 	switch (PTR_ERR(mp)) {
655 	case 0:
656 		break;
657 
658 	case -EAGAIN:
659 rehash:
660 		mdb = br->mdb;
661 		hash = br_ip_hash(mdb, group);
662 		break;
663 
664 	default:
665 		goto out;
666 	}
667 
668 	mp = kzalloc(sizeof(*mp), GFP_ATOMIC);
669 	if (unlikely(!mp))
670 		goto out;
671 
672 	mp->br = br;
673 	mp->addr = *group;
674 	setup_timer(&mp->timer, br_multicast_group_expired,
675 		    (unsigned long)mp);
676 	setup_timer(&mp->query_timer, br_multicast_group_query_expired,
677 		    (unsigned long)mp);
678 
679 	hlist_add_head_rcu(&mp->hlist[mdb->ver], &mdb->mhash[hash]);
680 	mdb->size++;
681 
682 out:
683 	return mp;
684 }
685 
686 static int br_multicast_add_group(struct net_bridge *br,
687 				  struct net_bridge_port *port,
688 				  struct br_ip *group)
689 {
690 	struct net_bridge_mdb_entry *mp;
691 	struct net_bridge_port_group *p;
692 	struct net_bridge_port_group **pp;
693 	unsigned long now = jiffies;
694 	int err;
695 
696 	spin_lock(&br->multicast_lock);
697 	if (!netif_running(br->dev) ||
698 	    (port && port->state == BR_STATE_DISABLED))
699 		goto out;
700 
701 	mp = br_multicast_new_group(br, port, group);
702 	err = PTR_ERR(mp);
703 	if (unlikely(IS_ERR(mp) || !mp))
704 		goto err;
705 
706 	if (!port) {
707 		hlist_add_head(&mp->mglist, &br->mglist);
708 		mod_timer(&mp->timer, now + br->multicast_membership_interval);
709 		goto out;
710 	}
711 
712 	for (pp = &mp->ports; (p = *pp); pp = &p->next) {
713 		if (p->port == port)
714 			goto found;
715 		if ((unsigned long)p->port < (unsigned long)port)
716 			break;
717 	}
718 
719 	p = kzalloc(sizeof(*p), GFP_ATOMIC);
720 	err = -ENOMEM;
721 	if (unlikely(!p))
722 		goto err;
723 
724 	p->addr = *group;
725 	p->port = port;
726 	p->next = *pp;
727 	hlist_add_head(&p->mglist, &port->mglist);
728 	setup_timer(&p->timer, br_multicast_port_group_expired,
729 		    (unsigned long)p);
730 	setup_timer(&p->query_timer, br_multicast_port_group_query_expired,
731 		    (unsigned long)p);
732 
733 	rcu_assign_pointer(*pp, p);
734 
735 found:
736 	mod_timer(&p->timer, now + br->multicast_membership_interval);
737 out:
738 	err = 0;
739 
740 err:
741 	spin_unlock(&br->multicast_lock);
742 	return err;
743 }
744 
745 static int br_ip4_multicast_add_group(struct net_bridge *br,
746 				      struct net_bridge_port *port,
747 				      __be32 group)
748 {
749 	struct br_ip br_group;
750 
751 	if (ipv4_is_local_multicast(group))
752 		return 0;
753 
754 	br_group.u.ip4 = group;
755 	br_group.proto = htons(ETH_P_IP);
756 
757 	return br_multicast_add_group(br, port, &br_group);
758 }
759 
760 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
761 static int br_ip6_multicast_add_group(struct net_bridge *br,
762 				      struct net_bridge_port *port,
763 				      const struct in6_addr *group)
764 {
765 	struct br_ip br_group;
766 
767 	if (ipv6_is_local_multicast(group))
768 		return 0;
769 
770 	ipv6_addr_copy(&br_group.u.ip6, group);
771 	br_group.proto = htons(ETH_P_IP);
772 
773 	return br_multicast_add_group(br, port, &br_group);
774 }
775 #endif
776 
777 static void br_multicast_router_expired(unsigned long data)
778 {
779 	struct net_bridge_port *port = (void *)data;
780 	struct net_bridge *br = port->br;
781 
782 	spin_lock(&br->multicast_lock);
783 	if (port->multicast_router != 1 ||
784 	    timer_pending(&port->multicast_router_timer) ||
785 	    hlist_unhashed(&port->rlist))
786 		goto out;
787 
788 	hlist_del_init_rcu(&port->rlist);
789 
790 out:
791 	spin_unlock(&br->multicast_lock);
792 }
793 
794 static void br_multicast_local_router_expired(unsigned long data)
795 {
796 }
797 
798 static void __br_multicast_send_query(struct net_bridge *br,
799 				      struct net_bridge_port *port,
800 				      struct br_ip *ip)
801 {
802 	struct sk_buff *skb;
803 
804 	skb = br_multicast_alloc_query(br, ip);
805 	if (!skb)
806 		return;
807 
808 	if (port) {
809 		__skb_push(skb, sizeof(struct ethhdr));
810 		skb->dev = port->dev;
811 		NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
812 			dev_queue_xmit);
813 	} else
814 		netif_rx(skb);
815 }
816 
817 static void br_multicast_send_query(struct net_bridge *br,
818 				    struct net_bridge_port *port, u32 sent)
819 {
820 	unsigned long time;
821 	struct br_ip br_group;
822 
823 	if (!netif_running(br->dev) || br->multicast_disabled ||
824 	    timer_pending(&br->multicast_querier_timer))
825 		return;
826 
827 	memset(&br_group.u, 0, sizeof(br_group.u));
828 
829 	br_group.proto = htons(ETH_P_IP);
830 	__br_multicast_send_query(br, port, &br_group);
831 
832 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
833 	br_group.proto = htons(ETH_P_IPV6);
834 	__br_multicast_send_query(br, port, &br_group);
835 #endif
836 
837 	time = jiffies;
838 	time += sent < br->multicast_startup_query_count ?
839 		br->multicast_startup_query_interval :
840 		br->multicast_query_interval;
841 	mod_timer(port ? &port->multicast_query_timer :
842 			 &br->multicast_query_timer, time);
843 }
844 
845 static void br_multicast_port_query_expired(unsigned long data)
846 {
847 	struct net_bridge_port *port = (void *)data;
848 	struct net_bridge *br = port->br;
849 
850 	spin_lock(&br->multicast_lock);
851 	if (port->state == BR_STATE_DISABLED ||
852 	    port->state == BR_STATE_BLOCKING)
853 		goto out;
854 
855 	if (port->multicast_startup_queries_sent <
856 	    br->multicast_startup_query_count)
857 		port->multicast_startup_queries_sent++;
858 
859 	br_multicast_send_query(port->br, port,
860 				port->multicast_startup_queries_sent);
861 
862 out:
863 	spin_unlock(&br->multicast_lock);
864 }
865 
866 void br_multicast_add_port(struct net_bridge_port *port)
867 {
868 	port->multicast_router = 1;
869 
870 	setup_timer(&port->multicast_router_timer, br_multicast_router_expired,
871 		    (unsigned long)port);
872 	setup_timer(&port->multicast_query_timer,
873 		    br_multicast_port_query_expired, (unsigned long)port);
874 }
875 
876 void br_multicast_del_port(struct net_bridge_port *port)
877 {
878 	del_timer_sync(&port->multicast_router_timer);
879 }
880 
881 static void __br_multicast_enable_port(struct net_bridge_port *port)
882 {
883 	port->multicast_startup_queries_sent = 0;
884 
885 	if (try_to_del_timer_sync(&port->multicast_query_timer) >= 0 ||
886 	    del_timer(&port->multicast_query_timer))
887 		mod_timer(&port->multicast_query_timer, jiffies);
888 }
889 
890 void br_multicast_enable_port(struct net_bridge_port *port)
891 {
892 	struct net_bridge *br = port->br;
893 
894 	spin_lock(&br->multicast_lock);
895 	if (br->multicast_disabled || !netif_running(br->dev))
896 		goto out;
897 
898 	__br_multicast_enable_port(port);
899 
900 out:
901 	spin_unlock(&br->multicast_lock);
902 }
903 
904 void br_multicast_disable_port(struct net_bridge_port *port)
905 {
906 	struct net_bridge *br = port->br;
907 	struct net_bridge_port_group *pg;
908 	struct hlist_node *p, *n;
909 
910 	spin_lock(&br->multicast_lock);
911 	hlist_for_each_entry_safe(pg, p, n, &port->mglist, mglist)
912 		br_multicast_del_pg(br, pg);
913 
914 	if (!hlist_unhashed(&port->rlist))
915 		hlist_del_init_rcu(&port->rlist);
916 	del_timer(&port->multicast_router_timer);
917 	del_timer(&port->multicast_query_timer);
918 	spin_unlock(&br->multicast_lock);
919 }
920 
921 static int br_ip4_multicast_igmp3_report(struct net_bridge *br,
922 					 struct net_bridge_port *port,
923 					 struct sk_buff *skb)
924 {
925 	struct igmpv3_report *ih;
926 	struct igmpv3_grec *grec;
927 	int i;
928 	int len;
929 	int num;
930 	int type;
931 	int err = 0;
932 	__be32 group;
933 
934 	if (!pskb_may_pull(skb, sizeof(*ih)))
935 		return -EINVAL;
936 
937 	ih = igmpv3_report_hdr(skb);
938 	num = ntohs(ih->ngrec);
939 	len = sizeof(*ih);
940 
941 	for (i = 0; i < num; i++) {
942 		len += sizeof(*grec);
943 		if (!pskb_may_pull(skb, len))
944 			return -EINVAL;
945 
946 		grec = (void *)(skb->data + len - sizeof(*grec));
947 		group = grec->grec_mca;
948 		type = grec->grec_type;
949 
950 		len += ntohs(grec->grec_nsrcs) * 4;
951 		if (!pskb_may_pull(skb, len))
952 			return -EINVAL;
953 
954 		/* We treat this as an IGMPv2 report for now. */
955 		switch (type) {
956 		case IGMPV3_MODE_IS_INCLUDE:
957 		case IGMPV3_MODE_IS_EXCLUDE:
958 		case IGMPV3_CHANGE_TO_INCLUDE:
959 		case IGMPV3_CHANGE_TO_EXCLUDE:
960 		case IGMPV3_ALLOW_NEW_SOURCES:
961 		case IGMPV3_BLOCK_OLD_SOURCES:
962 			break;
963 
964 		default:
965 			continue;
966 		}
967 
968 		err = br_ip4_multicast_add_group(br, port, group);
969 		if (err)
970 			break;
971 	}
972 
973 	return err;
974 }
975 
976 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
977 static int br_ip6_multicast_mld2_report(struct net_bridge *br,
978 					struct net_bridge_port *port,
979 					struct sk_buff *skb)
980 {
981 	struct icmp6hdr *icmp6h;
982 	struct mld2_grec *grec;
983 	int i;
984 	int len;
985 	int num;
986 	int err = 0;
987 
988 	if (!pskb_may_pull(skb, sizeof(*icmp6h)))
989 		return -EINVAL;
990 
991 	icmp6h = icmp6_hdr(skb);
992 	num = ntohs(icmp6h->icmp6_dataun.un_data16[1]);
993 	len = sizeof(*icmp6h);
994 
995 	for (i = 0; i < num; i++) {
996 		__be16 *nsrcs, _nsrcs;
997 
998 		nsrcs = skb_header_pointer(skb,
999 					   len + offsetof(struct mld2_grec,
1000 							  grec_mca),
1001 					   sizeof(_nsrcs), &_nsrcs);
1002 		if (!nsrcs)
1003 			return -EINVAL;
1004 
1005 		if (!pskb_may_pull(skb,
1006 				   len + sizeof(*grec) +
1007 				   sizeof(struct in6_addr) * (*nsrcs)))
1008 			return -EINVAL;
1009 
1010 		grec = (struct mld2_grec *)(skb->data + len);
1011 		len += sizeof(*grec) + sizeof(struct in6_addr) * (*nsrcs);
1012 
1013 		/* We treat these as MLDv1 reports for now. */
1014 		switch (grec->grec_type) {
1015 		case MLD2_MODE_IS_INCLUDE:
1016 		case MLD2_MODE_IS_EXCLUDE:
1017 		case MLD2_CHANGE_TO_INCLUDE:
1018 		case MLD2_CHANGE_TO_EXCLUDE:
1019 		case MLD2_ALLOW_NEW_SOURCES:
1020 		case MLD2_BLOCK_OLD_SOURCES:
1021 			break;
1022 
1023 		default:
1024 			continue;
1025 		}
1026 
1027 		err = br_ip6_multicast_add_group(br, port, &grec->grec_mca);
1028 		if (!err)
1029 			break;
1030 	}
1031 
1032 	return err;
1033 }
1034 #endif
1035 
1036 /*
1037  * Add port to rotuer_list
1038  *  list is maintained ordered by pointer value
1039  *  and locked by br->multicast_lock and RCU
1040  */
1041 static void br_multicast_add_router(struct net_bridge *br,
1042 				    struct net_bridge_port *port)
1043 {
1044 	struct net_bridge_port *p;
1045 	struct hlist_node *n, *slot = NULL;
1046 
1047 	hlist_for_each_entry(p, n, &br->router_list, rlist) {
1048 		if ((unsigned long) port >= (unsigned long) p)
1049 			break;
1050 		slot = n;
1051 	}
1052 
1053 	if (slot)
1054 		hlist_add_after_rcu(slot, &port->rlist);
1055 	else
1056 		hlist_add_head_rcu(&port->rlist, &br->router_list);
1057 }
1058 
1059 static void br_multicast_mark_router(struct net_bridge *br,
1060 				     struct net_bridge_port *port)
1061 {
1062 	unsigned long now = jiffies;
1063 
1064 	if (!port) {
1065 		if (br->multicast_router == 1)
1066 			mod_timer(&br->multicast_router_timer,
1067 				  now + br->multicast_querier_interval);
1068 		return;
1069 	}
1070 
1071 	if (port->multicast_router != 1)
1072 		return;
1073 
1074 	if (!hlist_unhashed(&port->rlist))
1075 		goto timer;
1076 
1077 	br_multicast_add_router(br, port);
1078 
1079 timer:
1080 	mod_timer(&port->multicast_router_timer,
1081 		  now + br->multicast_querier_interval);
1082 }
1083 
1084 static void br_multicast_query_received(struct net_bridge *br,
1085 					struct net_bridge_port *port,
1086 					int saddr)
1087 {
1088 	if (saddr)
1089 		mod_timer(&br->multicast_querier_timer,
1090 			  jiffies + br->multicast_querier_interval);
1091 	else if (timer_pending(&br->multicast_querier_timer))
1092 		return;
1093 
1094 	br_multicast_mark_router(br, port);
1095 }
1096 
1097 static int br_ip4_multicast_query(struct net_bridge *br,
1098 				  struct net_bridge_port *port,
1099 				  struct sk_buff *skb)
1100 {
1101 	struct iphdr *iph = ip_hdr(skb);
1102 	struct igmphdr *ih = igmp_hdr(skb);
1103 	struct net_bridge_mdb_entry *mp;
1104 	struct igmpv3_query *ih3;
1105 	struct net_bridge_port_group *p;
1106 	struct net_bridge_port_group **pp;
1107 	unsigned long max_delay;
1108 	unsigned long now = jiffies;
1109 	__be32 group;
1110 	int err = 0;
1111 
1112 	spin_lock(&br->multicast_lock);
1113 	if (!netif_running(br->dev) ||
1114 	    (port && port->state == BR_STATE_DISABLED))
1115 		goto out;
1116 
1117 	br_multicast_query_received(br, port, !!iph->saddr);
1118 
1119 	group = ih->group;
1120 
1121 	if (skb->len == sizeof(*ih)) {
1122 		max_delay = ih->code * (HZ / IGMP_TIMER_SCALE);
1123 
1124 		if (!max_delay) {
1125 			max_delay = 10 * HZ;
1126 			group = 0;
1127 		}
1128 	} else {
1129 		if (!pskb_may_pull(skb, sizeof(struct igmpv3_query))) {
1130 			err = -EINVAL;
1131 			goto out;
1132 		}
1133 
1134 		ih3 = igmpv3_query_hdr(skb);
1135 		if (ih3->nsrcs)
1136 			goto out;
1137 
1138 		max_delay = ih3->code ?
1139 			    IGMPV3_MRC(ih3->code) * (HZ / IGMP_TIMER_SCALE) : 1;
1140 	}
1141 
1142 	if (!group)
1143 		goto out;
1144 
1145 	mp = br_mdb_ip4_get(br->mdb, group);
1146 	if (!mp)
1147 		goto out;
1148 
1149 	max_delay *= br->multicast_last_member_count;
1150 
1151 	if (!hlist_unhashed(&mp->mglist) &&
1152 	    (timer_pending(&mp->timer) ?
1153 	     time_after(mp->timer.expires, now + max_delay) :
1154 	     try_to_del_timer_sync(&mp->timer) >= 0))
1155 		mod_timer(&mp->timer, now + max_delay);
1156 
1157 	for (pp = &mp->ports; (p = *pp); pp = &p->next) {
1158 		if (timer_pending(&p->timer) ?
1159 		    time_after(p->timer.expires, now + max_delay) :
1160 		    try_to_del_timer_sync(&p->timer) >= 0)
1161 			mod_timer(&mp->timer, now + max_delay);
1162 	}
1163 
1164 out:
1165 	spin_unlock(&br->multicast_lock);
1166 	return err;
1167 }
1168 
1169 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1170 static int br_ip6_multicast_query(struct net_bridge *br,
1171 				  struct net_bridge_port *port,
1172 				  struct sk_buff *skb)
1173 {
1174 	struct ipv6hdr *ip6h = ipv6_hdr(skb);
1175 	struct mld_msg *mld = (struct mld_msg *) icmp6_hdr(skb);
1176 	struct net_bridge_mdb_entry *mp;
1177 	struct mld2_query *mld2q;
1178 	struct net_bridge_port_group *p, **pp;
1179 	unsigned long max_delay;
1180 	unsigned long now = jiffies;
1181 	struct in6_addr *group = NULL;
1182 	int err = 0;
1183 
1184 	spin_lock(&br->multicast_lock);
1185 	if (!netif_running(br->dev) ||
1186 	    (port && port->state == BR_STATE_DISABLED))
1187 		goto out;
1188 
1189 	br_multicast_query_received(br, port, !ipv6_addr_any(&ip6h->saddr));
1190 
1191 	if (skb->len == sizeof(*mld)) {
1192 		if (!pskb_may_pull(skb, sizeof(*mld))) {
1193 			err = -EINVAL;
1194 			goto out;
1195 		}
1196 		mld = (struct mld_msg *) icmp6_hdr(skb);
1197 		max_delay = msecs_to_jiffies(htons(mld->mld_maxdelay));
1198 		if (max_delay)
1199 			group = &mld->mld_mca;
1200 	} else if (skb->len >= sizeof(*mld2q)) {
1201 		if (!pskb_may_pull(skb, sizeof(*mld2q))) {
1202 			err = -EINVAL;
1203 			goto out;
1204 		}
1205 		mld2q = (struct mld2_query *)icmp6_hdr(skb);
1206 		if (!mld2q->mld2q_nsrcs)
1207 			group = &mld2q->mld2q_mca;
1208 		max_delay = mld2q->mld2q_mrc ? MLDV2_MRC(mld2q->mld2q_mrc) : 1;
1209 	}
1210 
1211 	if (!group)
1212 		goto out;
1213 
1214 	mp = br_mdb_ip6_get(br->mdb, group);
1215 	if (!mp)
1216 		goto out;
1217 
1218 	max_delay *= br->multicast_last_member_count;
1219 	if (!hlist_unhashed(&mp->mglist) &&
1220 	    (timer_pending(&mp->timer) ?
1221 	     time_after(mp->timer.expires, now + max_delay) :
1222 	     try_to_del_timer_sync(&mp->timer) >= 0))
1223 		mod_timer(&mp->timer, now + max_delay);
1224 
1225 	for (pp = &mp->ports; (p = *pp); pp = &p->next) {
1226 		if (timer_pending(&p->timer) ?
1227 		    time_after(p->timer.expires, now + max_delay) :
1228 		    try_to_del_timer_sync(&p->timer) >= 0)
1229 			mod_timer(&mp->timer, now + max_delay);
1230 	}
1231 
1232 out:
1233 	spin_unlock(&br->multicast_lock);
1234 	return err;
1235 }
1236 #endif
1237 
1238 static void br_multicast_leave_group(struct net_bridge *br,
1239 				     struct net_bridge_port *port,
1240 				     struct br_ip *group)
1241 {
1242 	struct net_bridge_mdb_htable *mdb;
1243 	struct net_bridge_mdb_entry *mp;
1244 	struct net_bridge_port_group *p;
1245 	unsigned long now;
1246 	unsigned long time;
1247 
1248 	spin_lock(&br->multicast_lock);
1249 	if (!netif_running(br->dev) ||
1250 	    (port && port->state == BR_STATE_DISABLED) ||
1251 	    timer_pending(&br->multicast_querier_timer))
1252 		goto out;
1253 
1254 	mdb = br->mdb;
1255 	mp = br_mdb_ip_get(mdb, group);
1256 	if (!mp)
1257 		goto out;
1258 
1259 	now = jiffies;
1260 	time = now + br->multicast_last_member_count *
1261 		     br->multicast_last_member_interval;
1262 
1263 	if (!port) {
1264 		if (!hlist_unhashed(&mp->mglist) &&
1265 		    (timer_pending(&mp->timer) ?
1266 		     time_after(mp->timer.expires, time) :
1267 		     try_to_del_timer_sync(&mp->timer) >= 0)) {
1268 			mod_timer(&mp->timer, time);
1269 
1270 			mp->queries_sent = 0;
1271 			mod_timer(&mp->query_timer, now);
1272 		}
1273 
1274 		goto out;
1275 	}
1276 
1277 	for (p = mp->ports; p; p = p->next) {
1278 		if (p->port != port)
1279 			continue;
1280 
1281 		if (!hlist_unhashed(&p->mglist) &&
1282 		    (timer_pending(&p->timer) ?
1283 		     time_after(p->timer.expires, time) :
1284 		     try_to_del_timer_sync(&p->timer) >= 0)) {
1285 			mod_timer(&p->timer, time);
1286 
1287 			p->queries_sent = 0;
1288 			mod_timer(&p->query_timer, now);
1289 		}
1290 
1291 		break;
1292 	}
1293 
1294 out:
1295 	spin_unlock(&br->multicast_lock);
1296 }
1297 
1298 static void br_ip4_multicast_leave_group(struct net_bridge *br,
1299 					 struct net_bridge_port *port,
1300 					 __be32 group)
1301 {
1302 	struct br_ip br_group;
1303 
1304 	if (ipv4_is_local_multicast(group))
1305 		return;
1306 
1307 	br_group.u.ip4 = group;
1308 	br_group.proto = htons(ETH_P_IP);
1309 
1310 	br_multicast_leave_group(br, port, &br_group);
1311 }
1312 
1313 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1314 static void br_ip6_multicast_leave_group(struct net_bridge *br,
1315 					 struct net_bridge_port *port,
1316 					 const struct in6_addr *group)
1317 {
1318 	struct br_ip br_group;
1319 
1320 	if (ipv6_is_local_multicast(group))
1321 		return;
1322 
1323 	ipv6_addr_copy(&br_group.u.ip6, group);
1324 	br_group.proto = htons(ETH_P_IPV6);
1325 
1326 	br_multicast_leave_group(br, port, &br_group);
1327 }
1328 #endif
1329 
1330 static int br_multicast_ipv4_rcv(struct net_bridge *br,
1331 				 struct net_bridge_port *port,
1332 				 struct sk_buff *skb)
1333 {
1334 	struct sk_buff *skb2 = skb;
1335 	struct iphdr *iph;
1336 	struct igmphdr *ih;
1337 	unsigned len;
1338 	unsigned offset;
1339 	int err;
1340 
1341 	/* We treat OOM as packet loss for now. */
1342 	if (!pskb_may_pull(skb, sizeof(*iph)))
1343 		return -EINVAL;
1344 
1345 	iph = ip_hdr(skb);
1346 
1347 	if (iph->ihl < 5 || iph->version != 4)
1348 		return -EINVAL;
1349 
1350 	if (!pskb_may_pull(skb, ip_hdrlen(skb)))
1351 		return -EINVAL;
1352 
1353 	iph = ip_hdr(skb);
1354 
1355 	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1356 		return -EINVAL;
1357 
1358 	if (iph->protocol != IPPROTO_IGMP)
1359 		return 0;
1360 
1361 	len = ntohs(iph->tot_len);
1362 	if (skb->len < len || len < ip_hdrlen(skb))
1363 		return -EINVAL;
1364 
1365 	if (skb->len > len) {
1366 		skb2 = skb_clone(skb, GFP_ATOMIC);
1367 		if (!skb2)
1368 			return -ENOMEM;
1369 
1370 		err = pskb_trim_rcsum(skb2, len);
1371 		if (err)
1372 			goto err_out;
1373 	}
1374 
1375 	len -= ip_hdrlen(skb2);
1376 	offset = skb_network_offset(skb2) + ip_hdrlen(skb2);
1377 	__skb_pull(skb2, offset);
1378 	skb_reset_transport_header(skb2);
1379 
1380 	err = -EINVAL;
1381 	if (!pskb_may_pull(skb2, sizeof(*ih)))
1382 		goto out;
1383 
1384 	switch (skb2->ip_summed) {
1385 	case CHECKSUM_COMPLETE:
1386 		if (!csum_fold(skb2->csum))
1387 			break;
1388 		/* fall through */
1389 	case CHECKSUM_NONE:
1390 		skb2->csum = 0;
1391 		if (skb_checksum_complete(skb2))
1392 			goto out;
1393 	}
1394 
1395 	err = 0;
1396 
1397 	BR_INPUT_SKB_CB(skb)->igmp = 1;
1398 	ih = igmp_hdr(skb2);
1399 
1400 	switch (ih->type) {
1401 	case IGMP_HOST_MEMBERSHIP_REPORT:
1402 	case IGMPV2_HOST_MEMBERSHIP_REPORT:
1403 		BR_INPUT_SKB_CB(skb2)->mrouters_only = 1;
1404 		err = br_ip4_multicast_add_group(br, port, ih->group);
1405 		break;
1406 	case IGMPV3_HOST_MEMBERSHIP_REPORT:
1407 		err = br_ip4_multicast_igmp3_report(br, port, skb2);
1408 		break;
1409 	case IGMP_HOST_MEMBERSHIP_QUERY:
1410 		err = br_ip4_multicast_query(br, port, skb2);
1411 		break;
1412 	case IGMP_HOST_LEAVE_MESSAGE:
1413 		br_ip4_multicast_leave_group(br, port, ih->group);
1414 		break;
1415 	}
1416 
1417 out:
1418 	__skb_push(skb2, offset);
1419 err_out:
1420 	if (skb2 != skb)
1421 		kfree_skb(skb2);
1422 	return err;
1423 }
1424 
1425 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1426 static int br_multicast_ipv6_rcv(struct net_bridge *br,
1427 				 struct net_bridge_port *port,
1428 				 struct sk_buff *skb)
1429 {
1430 	struct sk_buff *skb2 = skb;
1431 	struct ipv6hdr *ip6h;
1432 	struct icmp6hdr *icmp6h;
1433 	u8 nexthdr;
1434 	unsigned len;
1435 	unsigned offset;
1436 	int err;
1437 
1438 	if (!pskb_may_pull(skb, sizeof(*ip6h)))
1439 		return -EINVAL;
1440 
1441 	ip6h = ipv6_hdr(skb);
1442 
1443 	/*
1444 	 * We're interested in MLD messages only.
1445 	 *  - Version is 6
1446 	 *  - MLD has always Router Alert hop-by-hop option
1447 	 *  - But we do not support jumbrograms.
1448 	 */
1449 	if (ip6h->version != 6 ||
1450 	    ip6h->nexthdr != IPPROTO_HOPOPTS ||
1451 	    ip6h->payload_len == 0)
1452 		return 0;
1453 
1454 	len = ntohs(ip6h->payload_len);
1455 	if (skb->len < len)
1456 		return -EINVAL;
1457 
1458 	nexthdr = ip6h->nexthdr;
1459 	offset = ipv6_skip_exthdr(skb, sizeof(*ip6h), &nexthdr);
1460 
1461 	if (offset < 0 || nexthdr != IPPROTO_ICMPV6)
1462 		return 0;
1463 
1464 	/* Okay, we found ICMPv6 header */
1465 	skb2 = skb_clone(skb, GFP_ATOMIC);
1466 	if (!skb2)
1467 		return -ENOMEM;
1468 
1469 	len -= offset - skb_network_offset(skb2);
1470 
1471 	__skb_pull(skb2, offset);
1472 	skb_reset_transport_header(skb2);
1473 
1474 	err = -EINVAL;
1475 	if (!pskb_may_pull(skb2, sizeof(*icmp6h)))
1476 		goto out;
1477 
1478 	icmp6h = icmp6_hdr(skb2);
1479 
1480 	switch (icmp6h->icmp6_type) {
1481 	case ICMPV6_MGM_QUERY:
1482 	case ICMPV6_MGM_REPORT:
1483 	case ICMPV6_MGM_REDUCTION:
1484 	case ICMPV6_MLD2_REPORT:
1485 		break;
1486 	default:
1487 		err = 0;
1488 		goto out;
1489 	}
1490 
1491 	/* Okay, we found MLD message. Check further. */
1492 	if (skb2->len > len) {
1493 		err = pskb_trim_rcsum(skb2, len);
1494 		if (err)
1495 			goto out;
1496 	}
1497 
1498 	switch (skb2->ip_summed) {
1499 	case CHECKSUM_COMPLETE:
1500 		if (!csum_fold(skb2->csum))
1501 			break;
1502 		/*FALLTHROUGH*/
1503 	case CHECKSUM_NONE:
1504 		skb2->csum = 0;
1505 		if (skb_checksum_complete(skb2))
1506 			goto out;
1507 	}
1508 
1509 	err = 0;
1510 
1511 	BR_INPUT_SKB_CB(skb)->igmp = 1;
1512 
1513 	switch (icmp6h->icmp6_type) {
1514 	case ICMPV6_MGM_REPORT:
1515 	    {
1516 		struct mld_msg *mld = (struct mld_msg *)icmp6h;
1517 		BR_INPUT_SKB_CB(skb2)->mrouters_only = 1;
1518 		err = br_ip6_multicast_add_group(br, port, &mld->mld_mca);
1519 		break;
1520 	    }
1521 	case ICMPV6_MLD2_REPORT:
1522 		err = br_ip6_multicast_mld2_report(br, port, skb2);
1523 		break;
1524 	case ICMPV6_MGM_QUERY:
1525 		err = br_ip6_multicast_query(br, port, skb2);
1526 		break;
1527 	case ICMPV6_MGM_REDUCTION:
1528 	    {
1529 		struct mld_msg *mld = (struct mld_msg *)icmp6h;
1530 		br_ip6_multicast_leave_group(br, port, &mld->mld_mca);
1531 	    }
1532 	}
1533 
1534 out:
1535 	__skb_push(skb2, offset);
1536 	if (skb2 != skb)
1537 		kfree_skb(skb2);
1538 	return err;
1539 }
1540 #endif
1541 
1542 int br_multicast_rcv(struct net_bridge *br, struct net_bridge_port *port,
1543 		     struct sk_buff *skb)
1544 {
1545 	BR_INPUT_SKB_CB(skb)->igmp = 0;
1546 	BR_INPUT_SKB_CB(skb)->mrouters_only = 0;
1547 
1548 	if (br->multicast_disabled)
1549 		return 0;
1550 
1551 	switch (skb->protocol) {
1552 	case htons(ETH_P_IP):
1553 		return br_multicast_ipv4_rcv(br, port, skb);
1554 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1555 	case htons(ETH_P_IPV6):
1556 		return br_multicast_ipv6_rcv(br, port, skb);
1557 #endif
1558 	}
1559 
1560 	return 0;
1561 }
1562 
1563 static void br_multicast_query_expired(unsigned long data)
1564 {
1565 	struct net_bridge *br = (void *)data;
1566 
1567 	spin_lock(&br->multicast_lock);
1568 	if (br->multicast_startup_queries_sent <
1569 	    br->multicast_startup_query_count)
1570 		br->multicast_startup_queries_sent++;
1571 
1572 	br_multicast_send_query(br, NULL, br->multicast_startup_queries_sent);
1573 
1574 	spin_unlock(&br->multicast_lock);
1575 }
1576 
1577 void br_multicast_init(struct net_bridge *br)
1578 {
1579 	br->hash_elasticity = 4;
1580 	br->hash_max = 512;
1581 
1582 	br->multicast_router = 1;
1583 	br->multicast_last_member_count = 2;
1584 	br->multicast_startup_query_count = 2;
1585 
1586 	br->multicast_last_member_interval = HZ;
1587 	br->multicast_query_response_interval = 10 * HZ;
1588 	br->multicast_startup_query_interval = 125 * HZ / 4;
1589 	br->multicast_query_interval = 125 * HZ;
1590 	br->multicast_querier_interval = 255 * HZ;
1591 	br->multicast_membership_interval = 260 * HZ;
1592 
1593 	spin_lock_init(&br->multicast_lock);
1594 	setup_timer(&br->multicast_router_timer,
1595 		    br_multicast_local_router_expired, 0);
1596 	setup_timer(&br->multicast_querier_timer,
1597 		    br_multicast_local_router_expired, 0);
1598 	setup_timer(&br->multicast_query_timer, br_multicast_query_expired,
1599 		    (unsigned long)br);
1600 }
1601 
1602 void br_multicast_open(struct net_bridge *br)
1603 {
1604 	br->multicast_startup_queries_sent = 0;
1605 
1606 	if (br->multicast_disabled)
1607 		return;
1608 
1609 	mod_timer(&br->multicast_query_timer, jiffies);
1610 }
1611 
1612 void br_multicast_stop(struct net_bridge *br)
1613 {
1614 	struct net_bridge_mdb_htable *mdb;
1615 	struct net_bridge_mdb_entry *mp;
1616 	struct hlist_node *p, *n;
1617 	u32 ver;
1618 	int i;
1619 
1620 	del_timer_sync(&br->multicast_router_timer);
1621 	del_timer_sync(&br->multicast_querier_timer);
1622 	del_timer_sync(&br->multicast_query_timer);
1623 
1624 	spin_lock_bh(&br->multicast_lock);
1625 	mdb = br->mdb;
1626 	if (!mdb)
1627 		goto out;
1628 
1629 	br->mdb = NULL;
1630 
1631 	ver = mdb->ver;
1632 	for (i = 0; i < mdb->max; i++) {
1633 		hlist_for_each_entry_safe(mp, p, n, &mdb->mhash[i],
1634 					  hlist[ver]) {
1635 			del_timer(&mp->timer);
1636 			del_timer(&mp->query_timer);
1637 			call_rcu_bh(&mp->rcu, br_multicast_free_group);
1638 		}
1639 	}
1640 
1641 	if (mdb->old) {
1642 		spin_unlock_bh(&br->multicast_lock);
1643 		rcu_barrier_bh();
1644 		spin_lock_bh(&br->multicast_lock);
1645 		WARN_ON(mdb->old);
1646 	}
1647 
1648 	mdb->old = mdb;
1649 	call_rcu_bh(&mdb->rcu, br_mdb_free);
1650 
1651 out:
1652 	spin_unlock_bh(&br->multicast_lock);
1653 }
1654 
1655 int br_multicast_set_router(struct net_bridge *br, unsigned long val)
1656 {
1657 	int err = -ENOENT;
1658 
1659 	spin_lock_bh(&br->multicast_lock);
1660 	if (!netif_running(br->dev))
1661 		goto unlock;
1662 
1663 	switch (val) {
1664 	case 0:
1665 	case 2:
1666 		del_timer(&br->multicast_router_timer);
1667 		/* fall through */
1668 	case 1:
1669 		br->multicast_router = val;
1670 		err = 0;
1671 		break;
1672 
1673 	default:
1674 		err = -EINVAL;
1675 		break;
1676 	}
1677 
1678 unlock:
1679 	spin_unlock_bh(&br->multicast_lock);
1680 
1681 	return err;
1682 }
1683 
1684 int br_multicast_set_port_router(struct net_bridge_port *p, unsigned long val)
1685 {
1686 	struct net_bridge *br = p->br;
1687 	int err = -ENOENT;
1688 
1689 	spin_lock(&br->multicast_lock);
1690 	if (!netif_running(br->dev) || p->state == BR_STATE_DISABLED)
1691 		goto unlock;
1692 
1693 	switch (val) {
1694 	case 0:
1695 	case 1:
1696 	case 2:
1697 		p->multicast_router = val;
1698 		err = 0;
1699 
1700 		if (val < 2 && !hlist_unhashed(&p->rlist))
1701 			hlist_del_init_rcu(&p->rlist);
1702 
1703 		if (val == 1)
1704 			break;
1705 
1706 		del_timer(&p->multicast_router_timer);
1707 
1708 		if (val == 0)
1709 			break;
1710 
1711 		br_multicast_add_router(br, p);
1712 		break;
1713 
1714 	default:
1715 		err = -EINVAL;
1716 		break;
1717 	}
1718 
1719 unlock:
1720 	spin_unlock(&br->multicast_lock);
1721 
1722 	return err;
1723 }
1724 
1725 int br_multicast_toggle(struct net_bridge *br, unsigned long val)
1726 {
1727 	struct net_bridge_port *port;
1728 	int err = -ENOENT;
1729 
1730 	spin_lock(&br->multicast_lock);
1731 	if (!netif_running(br->dev))
1732 		goto unlock;
1733 
1734 	err = 0;
1735 	if (br->multicast_disabled == !val)
1736 		goto unlock;
1737 
1738 	br->multicast_disabled = !val;
1739 	if (br->multicast_disabled)
1740 		goto unlock;
1741 
1742 	if (br->mdb) {
1743 		if (br->mdb->old) {
1744 			err = -EEXIST;
1745 rollback:
1746 			br->multicast_disabled = !!val;
1747 			goto unlock;
1748 		}
1749 
1750 		err = br_mdb_rehash(&br->mdb, br->mdb->max,
1751 				    br->hash_elasticity);
1752 		if (err)
1753 			goto rollback;
1754 	}
1755 
1756 	br_multicast_open(br);
1757 	list_for_each_entry(port, &br->port_list, list) {
1758 		if (port->state == BR_STATE_DISABLED ||
1759 		    port->state == BR_STATE_BLOCKING)
1760 			continue;
1761 
1762 		__br_multicast_enable_port(port);
1763 	}
1764 
1765 unlock:
1766 	spin_unlock(&br->multicast_lock);
1767 
1768 	return err;
1769 }
1770 
1771 int br_multicast_set_hash_max(struct net_bridge *br, unsigned long val)
1772 {
1773 	int err = -ENOENT;
1774 	u32 old;
1775 
1776 	spin_lock(&br->multicast_lock);
1777 	if (!netif_running(br->dev))
1778 		goto unlock;
1779 
1780 	err = -EINVAL;
1781 	if (!is_power_of_2(val))
1782 		goto unlock;
1783 	if (br->mdb && val < br->mdb->size)
1784 		goto unlock;
1785 
1786 	err = 0;
1787 
1788 	old = br->hash_max;
1789 	br->hash_max = val;
1790 
1791 	if (br->mdb) {
1792 		if (br->mdb->old) {
1793 			err = -EEXIST;
1794 rollback:
1795 			br->hash_max = old;
1796 			goto unlock;
1797 		}
1798 
1799 		err = br_mdb_rehash(&br->mdb, br->hash_max,
1800 				    br->hash_elasticity);
1801 		if (err)
1802 			goto rollback;
1803 	}
1804 
1805 unlock:
1806 	spin_unlock(&br->multicast_lock);
1807 
1808 	return err;
1809 }
1810