/*
   * Bridge multicast support.
   *
   * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License as published by the Free
   * Software Foundation; either version 2 of the License, or (at your option)
   * any later version.
   *
   */
  
  #include <linux/err.h>
  #include <linux/if_ether.h>
  #include <linux/igmp.h>
  #include <linux/jhash.h>
  #include <linux/kernel.h>

  #include <linux/log2.h>

  #include <linux/netdevice.h>
  #include <linux/netfilter_bridge.h>
  #include <linux/random.h>
  #include <linux/rculist.h>
  #include <linux/skbuff.h>
  #include <linux/slab.h>
  #include <linux/timer.h>
  #include <net/ip.h>

  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  #include <net/ipv6.h>
  #include <net/mld.h>
  #include <net/addrconf.h>

  #include <net/ip6_checksum.h>

  #endif

  
  #include "br_private.h"

  #define mlock_dereference(X, br) \
  	rcu_dereference_protected(X, lockdep_is_held(&br->multicast_lock))

  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)

  static inline int ipv6_is_transient_multicast(const struct in6_addr *addr)

  {

  	if (ipv6_addr_is_multicast(addr) && IPV6_ADDR_MC_FLAG_TRANSIENT(addr))

  		return 1;
  	return 0;
  }
  #endif

  static inline int br_ip_equal(const struct br_ip *a, const struct br_ip *b)
  {
  	if (a->proto != b->proto)
  		return 0;
  	switch (a->proto) {
  	case htons(ETH_P_IP):
  		return a->u.ip4 == b->u.ip4;

  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  	case htons(ETH_P_IPV6):
  		return ipv6_addr_equal(&a->u.ip6, &b->u.ip6);
  #endif

  	}
  	return 0;
  }
  
  static inline int __br_ip4_hash(struct net_bridge_mdb_htable *mdb, __be32 ip)

  {

  	return jhash_1word(mdb->secret, (__force u32)ip) & (mdb->max - 1);

  }

  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  static inline int __br_ip6_hash(struct net_bridge_mdb_htable *mdb,
  				const struct in6_addr *ip)
  {
  	return jhash2((__force u32 *)ip->s6_addr32, 4, mdb->secret) & (mdb->max - 1);
  }
  #endif

  static inline int br_ip_hash(struct net_bridge_mdb_htable *mdb,
  			     struct br_ip *ip)
  {
  	switch (ip->proto) {
  	case htons(ETH_P_IP):
  		return __br_ip4_hash(mdb, ip->u.ip4);

  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  	case htons(ETH_P_IPV6):
  		return __br_ip6_hash(mdb, &ip->u.ip6);
  #endif

  	}
  	return 0;

  }
  
  static struct net_bridge_mdb_entry *__br_mdb_ip_get(

  	struct net_bridge_mdb_htable *mdb, struct br_ip *dst, int hash)

  {
  	struct net_bridge_mdb_entry *mp;
  	struct hlist_node *p;

  	hlist_for_each_entry_rcu(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) {

  		if (br_ip_equal(&mp->addr, dst))

  			return mp;
  	}
  
  	return NULL;
  }

  static struct net_bridge_mdb_entry *br_mdb_ip_get(
  	struct net_bridge_mdb_htable *mdb, struct br_ip *dst)
  {
  	if (!mdb)
  		return NULL;
  
  	return __br_mdb_ip_get(mdb, dst, br_ip_hash(mdb, dst));
  }

  static struct net_bridge_mdb_entry *br_mdb_ip4_get(

  	struct net_bridge_mdb_htable *mdb, __be32 dst)
  {

  	struct br_ip br_dst;
  
  	br_dst.u.ip4 = dst;
  	br_dst.proto = htons(ETH_P_IP);

  	return br_mdb_ip_get(mdb, &br_dst);

  }

  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  static struct net_bridge_mdb_entry *br_mdb_ip6_get(
  	struct net_bridge_mdb_htable *mdb, const struct in6_addr *dst)
  {
  	struct br_ip br_dst;

  	ipv6_addr_copy(&br_dst.u.ip6, dst);
  	br_dst.proto = htons(ETH_P_IPV6);

  	return br_mdb_ip_get(mdb, &br_dst);

  }
  #endif

  struct net_bridge_mdb_entry *br_mdb_get(struct net_bridge *br,
  					struct sk_buff *skb)
  {

  	struct net_bridge_mdb_htable *mdb = rcu_dereference(br->mdb);

  	struct br_ip ip;

  	if (br->multicast_disabled)

  		return NULL;

  	if (BR_INPUT_SKB_CB(skb)->igmp)

  		return NULL;

  	ip.proto = skb->protocol;

  	switch (skb->protocol) {
  	case htons(ETH_P_IP):

  		ip.u.ip4 = ip_hdr(skb)->daddr;
  		break;

  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  	case htons(ETH_P_IPV6):
  		ipv6_addr_copy(&ip.u.ip6, &ipv6_hdr(skb)->daddr);
  		break;
  #endif

  	default:
  		return NULL;

  	}

  	return br_mdb_ip_get(mdb, &ip);

  }
  
  static void br_mdb_free(struct rcu_head *head)
  {
  	struct net_bridge_mdb_htable *mdb =
  		container_of(head, struct net_bridge_mdb_htable, rcu);
  	struct net_bridge_mdb_htable *old = mdb->old;
  
  	mdb->old = NULL;
  	kfree(old->mhash);
  	kfree(old);
  }
  
  static int br_mdb_copy(struct net_bridge_mdb_htable *new,
  		       struct net_bridge_mdb_htable *old,
  		       int elasticity)
  {
  	struct net_bridge_mdb_entry *mp;
  	struct hlist_node *p;
  	int maxlen;
  	int len;
  	int i;
  
  	for (i = 0; i < old->max; i++)
  		hlist_for_each_entry(mp, p, &old->mhash[i], hlist[old->ver])
  			hlist_add_head(&mp->hlist[new->ver],

  				       &new->mhash[br_ip_hash(new, &mp->addr)]);

  
  	if (!elasticity)
  		return 0;
  
  	maxlen = 0;
  	for (i = 0; i < new->max; i++) {
  		len = 0;
  		hlist_for_each_entry(mp, p, &new->mhash[i], hlist[new->ver])
  			len++;
  		if (len > maxlen)
  			maxlen = len;
  	}
  
  	return maxlen > elasticity ? -EINVAL : 0;
  }
  
  static void br_multicast_free_pg(struct rcu_head *head)
  {
  	struct net_bridge_port_group *p =
  		container_of(head, struct net_bridge_port_group, rcu);
  
  	kfree(p);
  }
  
  static void br_multicast_free_group(struct rcu_head *head)
  {
  	struct net_bridge_mdb_entry *mp =
  		container_of(head, struct net_bridge_mdb_entry, rcu);
  
  	kfree(mp);
  }
  
  static void br_multicast_group_expired(unsigned long data)
  {
  	struct net_bridge_mdb_entry *mp = (void *)data;
  	struct net_bridge *br = mp->br;
  	struct net_bridge_mdb_htable *mdb;
  
  	spin_lock(&br->multicast_lock);
  	if (!netif_running(br->dev) || timer_pending(&mp->timer))
  		goto out;

  	mp->mglist = false;

  
  	if (mp->ports)
  		goto out;

  	mdb = mlock_dereference(br->mdb, br);

  	hlist_del_rcu(&mp->hlist[mdb->ver]);
  	mdb->size--;
  
  	del_timer(&mp->query_timer);
  	call_rcu_bh(&mp->rcu, br_multicast_free_group);
  
  out:
  	spin_unlock(&br->multicast_lock);
  }
  
  static void br_multicast_del_pg(struct net_bridge *br,
  				struct net_bridge_port_group *pg)
  {

  	struct net_bridge_mdb_htable *mdb;

  	struct net_bridge_mdb_entry *mp;
  	struct net_bridge_port_group *p;

  	struct net_bridge_port_group __rcu **pp;
  
  	mdb = mlock_dereference(br->mdb, br);

  	mp = br_mdb_ip_get(mdb, &pg->addr);

  	if (WARN_ON(!mp))
  		return;

  	for (pp = &mp->ports;
  	     (p = mlock_dereference(*pp, br)) != NULL;
  	     pp = &p->next) {

  		if (p != pg)
  			continue;

  		rcu_assign_pointer(*pp, p->next);

  		hlist_del_init(&p->mglist);
  		del_timer(&p->timer);
  		del_timer(&p->query_timer);
  		call_rcu_bh(&p->rcu, br_multicast_free_pg);

  		if (!mp->ports && !mp->mglist &&

  		    netif_running(br->dev))
  			mod_timer(&mp->timer, jiffies);
  
  		return;
  	}
  
  	WARN_ON(1);
  }
  
  static void br_multicast_port_group_expired(unsigned long data)
  {
  	struct net_bridge_port_group *pg = (void *)data;
  	struct net_bridge *br = pg->port->br;
  
  	spin_lock(&br->multicast_lock);
  	if (!netif_running(br->dev) || timer_pending(&pg->timer) ||
  	    hlist_unhashed(&pg->mglist))
  		goto out;
  
  	br_multicast_del_pg(br, pg);
  
  out:
  	spin_unlock(&br->multicast_lock);
  }

  static int br_mdb_rehash(struct net_bridge_mdb_htable __rcu **mdbp, int max,

  			 int elasticity)
  {

  	struct net_bridge_mdb_htable *old = rcu_dereference_protected(*mdbp, 1);

  	struct net_bridge_mdb_htable *mdb;
  	int err;
  
  	mdb = kmalloc(sizeof(*mdb), GFP_ATOMIC);
  	if (!mdb)
  		return -ENOMEM;
  
  	mdb->max = max;
  	mdb->old = old;
  
  	mdb->mhash = kzalloc(max * sizeof(*mdb->mhash), GFP_ATOMIC);
  	if (!mdb->mhash) {
  		kfree(mdb);
  		return -ENOMEM;
  	}
  
  	mdb->size = old ? old->size : 0;
  	mdb->ver = old ? old->ver ^ 1 : 0;
  
  	if (!old || elasticity)
  		get_random_bytes(&mdb->secret, sizeof(mdb->secret));
  	else
  		mdb->secret = old->secret;
  
  	if (!old)
  		goto out;
  
  	err = br_mdb_copy(mdb, old, elasticity);
  	if (err) {
  		kfree(mdb->mhash);
  		kfree(mdb);
  		return err;
  	}
  
  	call_rcu_bh(&mdb->rcu, br_mdb_free);
  
  out:
  	rcu_assign_pointer(*mdbp, mdb);
  
  	return 0;
  }

  static struct sk_buff *br_ip4_multicast_alloc_query(struct net_bridge *br,
  						    __be32 group)

  {
  	struct sk_buff *skb;
  	struct igmphdr *ih;
  	struct ethhdr *eth;
  	struct iphdr *iph;
  
  	skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*iph) +
  						 sizeof(*ih) + 4);
  	if (!skb)
  		goto out;
  
  	skb->protocol = htons(ETH_P_IP);
  
  	skb_reset_mac_header(skb);
  	eth = eth_hdr(skb);
  
  	memcpy(eth->h_source, br->dev->dev_addr, 6);
  	eth->h_dest[0] = 1;
  	eth->h_dest[1] = 0;
  	eth->h_dest[2] = 0x5e;
  	eth->h_dest[3] = 0;
  	eth->h_dest[4] = 0;
  	eth->h_dest[5] = 1;
  	eth->h_proto = htons(ETH_P_IP);
  	skb_put(skb, sizeof(*eth));
  
  	skb_set_network_header(skb, skb->len);
  	iph = ip_hdr(skb);
  
  	iph->version = 4;
  	iph->ihl = 6;
  	iph->tos = 0xc0;
  	iph->tot_len = htons(sizeof(*iph) + sizeof(*ih) + 4);
  	iph->id = 0;
  	iph->frag_off = htons(IP_DF);
  	iph->ttl = 1;
  	iph->protocol = IPPROTO_IGMP;
  	iph->saddr = 0;
  	iph->daddr = htonl(INADDR_ALLHOSTS_GROUP);
  	((u8 *)&iph[1])[0] = IPOPT_RA;
  	((u8 *)&iph[1])[1] = 4;
  	((u8 *)&iph[1])[2] = 0;
  	((u8 *)&iph[1])[3] = 0;
  	ip_send_check(iph);
  	skb_put(skb, 24);
  
  	skb_set_transport_header(skb, skb->len);
  	ih = igmp_hdr(skb);
  	ih->type = IGMP_HOST_MEMBERSHIP_QUERY;
  	ih->code = (group ? br->multicast_last_member_interval :
  			    br->multicast_query_response_interval) /
  		   (HZ / IGMP_TIMER_SCALE);
  	ih->group = group;
  	ih->csum = 0;
  	ih->csum = ip_compute_csum((void *)ih, sizeof(struct igmphdr));
  	skb_put(skb, sizeof(*ih));
  
  	__skb_pull(skb, sizeof(*eth));
  
  out:
  	return skb;
  }

  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
  						    struct in6_addr *group)
  {
  	struct sk_buff *skb;
  	struct ipv6hdr *ip6h;
  	struct mld_msg *mldq;
  	struct ethhdr *eth;
  	u8 *hopopt;
  	unsigned long interval;
  
  	skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*ip6h) +
  						 8 + sizeof(*mldq));
  	if (!skb)
  		goto out;
  
  	skb->protocol = htons(ETH_P_IPV6);
  
  	/* Ethernet header */
  	skb_reset_mac_header(skb);
  	eth = eth_hdr(skb);
  
  	memcpy(eth->h_source, br->dev->dev_addr, 6);

  	eth->h_proto = htons(ETH_P_IPV6);
  	skb_put(skb, sizeof(*eth));
  
  	/* IPv6 header + HbH option */
  	skb_set_network_header(skb, skb->len);
  	ip6h = ipv6_hdr(skb);
  
  	*(__force __be32 *)ip6h = htonl(0x60000000);

  	ip6h->payload_len = htons(8 + sizeof(*mldq));

  	ip6h->nexthdr = IPPROTO_HOPOPTS;
  	ip6h->hop_limit = 1;

  	ipv6_dev_get_saddr(dev_net(br->dev), br->dev, &ip6h->daddr, 0,
  			   &ip6h->saddr);

  	ipv6_addr_set(&ip6h->daddr, htonl(0xff020000), 0, 0, htonl(1));

  	ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);

  
  	hopopt = (u8 *)(ip6h + 1);
  	hopopt[0] = IPPROTO_ICMPV6;		/* next hdr */
  	hopopt[1] = 0;				/* length of HbH */
  	hopopt[2] = IPV6_TLV_ROUTERALERT;	/* Router Alert */
  	hopopt[3] = 2;				/* Length of RA Option */
  	hopopt[4] = 0;				/* Type = 0x0000 (MLD) */
  	hopopt[5] = 0;
  	hopopt[6] = IPV6_TLV_PAD0;		/* Pad0 */
  	hopopt[7] = IPV6_TLV_PAD0;		/* Pad0 */
  
  	skb_put(skb, sizeof(*ip6h) + 8);
  
  	/* ICMPv6 */
  	skb_set_transport_header(skb, skb->len);
  	mldq = (struct mld_msg *) icmp6_hdr(skb);
  
  	interval = ipv6_addr_any(group) ? br->multicast_last_member_interval :
  					  br->multicast_query_response_interval;
  
  	mldq->mld_type = ICMPV6_MGM_QUERY;
  	mldq->mld_code = 0;
  	mldq->mld_cksum = 0;
  	mldq->mld_maxdelay = htons((u16)jiffies_to_msecs(interval));
  	mldq->mld_reserved = 0;
  	ipv6_addr_copy(&mldq->mld_mca, group);
  
  	/* checksum */
  	mldq->mld_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
  					  sizeof(*mldq), IPPROTO_ICMPV6,
  					  csum_partial(mldq,
  						       sizeof(*mldq), 0));
  	skb_put(skb, sizeof(*mldq));
  
  	__skb_pull(skb, sizeof(*eth));
  
  out:
  	return skb;
  }
  #endif

  static struct sk_buff *br_multicast_alloc_query(struct net_bridge *br,
  						struct br_ip *addr)
  {
  	switch (addr->proto) {
  	case htons(ETH_P_IP):
  		return br_ip4_multicast_alloc_query(br, addr->u.ip4);

  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  	case htons(ETH_P_IPV6):
  		return br_ip6_multicast_alloc_query(br, &addr->u.ip6);
  #endif

  	}
  	return NULL;
  }

  static void br_multicast_send_group_query(struct net_bridge_mdb_entry *mp)
  {
  	struct net_bridge *br = mp->br;
  	struct sk_buff *skb;

  	skb = br_multicast_alloc_query(br, &mp->addr);

  	if (!skb)
  		goto timer;
  
  	netif_rx(skb);
  
  timer:
  	if (++mp->queries_sent < br->multicast_last_member_count)
  		mod_timer(&mp->query_timer,
  			  jiffies + br->multicast_last_member_interval);
  }
  
  static void br_multicast_group_query_expired(unsigned long data)
  {
  	struct net_bridge_mdb_entry *mp = (void *)data;
  	struct net_bridge *br = mp->br;
  
  	spin_lock(&br->multicast_lock);

  	if (!netif_running(br->dev) || !mp->mglist ||

  	    mp->queries_sent >= br->multicast_last_member_count)
  		goto out;
  
  	br_multicast_send_group_query(mp);
  
  out:
  	spin_unlock(&br->multicast_lock);
  }
  
  static void br_multicast_send_port_group_query(struct net_bridge_port_group *pg)
  {
  	struct net_bridge_port *port = pg->port;
  	struct net_bridge *br = port->br;
  	struct sk_buff *skb;

  	skb = br_multicast_alloc_query(br, &pg->addr);

  	if (!skb)
  		goto timer;
  
  	br_deliver(port, skb);
  
  timer:
  	if (++pg->queries_sent < br->multicast_last_member_count)
  		mod_timer(&pg->query_timer,
  			  jiffies + br->multicast_last_member_interval);
  }
  
  static void br_multicast_port_group_query_expired(unsigned long data)
  {
  	struct net_bridge_port_group *pg = (void *)data;
  	struct net_bridge_port *port = pg->port;
  	struct net_bridge *br = port->br;
  
  	spin_lock(&br->multicast_lock);
  	if (!netif_running(br->dev) || hlist_unhashed(&pg->mglist) ||
  	    pg->queries_sent >= br->multicast_last_member_count)
  		goto out;
  
  	br_multicast_send_port_group_query(pg);
  
  out:
  	spin_unlock(&br->multicast_lock);
  }
  
  static struct net_bridge_mdb_entry *br_multicast_get_group(

  	struct net_bridge *br, struct net_bridge_port *port,
  	struct br_ip *group, int hash)

  {

  	struct net_bridge_mdb_htable *mdb;

  	struct net_bridge_mdb_entry *mp;
  	struct hlist_node *p;
  	unsigned count = 0;
  	unsigned max;
  	int elasticity;
  	int err;

  	mdb = rcu_dereference_protected(br->mdb, 1);

  	hlist_for_each_entry(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) {
  		count++;

  		if (unlikely(br_ip_equal(group, &mp->addr)))

  			return mp;

  	}
  
  	elasticity = 0;
  	max = mdb->max;
  
  	if (unlikely(count > br->hash_elasticity && count)) {
  		if (net_ratelimit())

  			br_info(br, "Multicast hash table "
  				"chain limit reached: %s
  ",
  				port ? port->dev->name : br->dev->name);

  
  		elasticity = br->hash_elasticity;
  	}
  
  	if (mdb->size >= max) {
  		max *= 2;
  		if (unlikely(max >= br->hash_max)) {

  			br_warn(br, "Multicast hash table maximum "
  				"reached, disabling snooping: %s, %d
  ",
  				port ? port->dev->name : br->dev->name, max);

  			err = -E2BIG;
  disable:
  			br->multicast_disabled = 1;
  			goto err;
  		}
  	}
  
  	if (max > mdb->max || elasticity) {
  		if (mdb->old) {
  			if (net_ratelimit())

  				br_info(br, "Multicast hash table "
  					"on fire: %s
  ",
  					port ? port->dev->name : br->dev->name);

  			err = -EEXIST;
  			goto err;
  		}
  
  		err = br_mdb_rehash(&br->mdb, max, elasticity);
  		if (err) {

  			br_warn(br, "Cannot rehash multicast "
  				"hash table, disabling snooping: %s, %d, %d
  ",
  				port ? port->dev->name : br->dev->name,
  				mdb->size, err);

  			goto disable;
  		}
  
  		err = -EAGAIN;
  		goto err;
  	}
  
  	return NULL;
  
  err:
  	mp = ERR_PTR(err);
  	return mp;
  }
  
  static struct net_bridge_mdb_entry *br_multicast_new_group(

  	struct net_bridge *br, struct net_bridge_port *port,
  	struct br_ip *group)

  {

  	struct net_bridge_mdb_htable *mdb;

  	struct net_bridge_mdb_entry *mp;
  	int hash;

  	int err;

  	mdb = rcu_dereference_protected(br->mdb, 1);

  	if (!mdb) {

  		err = br_mdb_rehash(&br->mdb, BR_HASH_SIZE, 0);
  		if (err)
  			return ERR_PTR(err);

  		goto rehash;
  	}
  
  	hash = br_ip_hash(mdb, group);
  	mp = br_multicast_get_group(br, port, group, hash);
  	switch (PTR_ERR(mp)) {
  	case 0:
  		break;
  
  	case -EAGAIN:
  rehash:

  		mdb = rcu_dereference_protected(br->mdb, 1);

  		hash = br_ip_hash(mdb, group);
  		break;
  
  	default:
  		goto out;
  	}
  
  	mp = kzalloc(sizeof(*mp), GFP_ATOMIC);
  	if (unlikely(!mp))

  		return ERR_PTR(-ENOMEM);

  
  	mp->br = br;

  	mp->addr = *group;

  	setup_timer(&mp->timer, br_multicast_group_expired,
  		    (unsigned long)mp);
  	setup_timer(&mp->query_timer, br_multicast_group_query_expired,
  		    (unsigned long)mp);
  
  	hlist_add_head_rcu(&mp->hlist[mdb->ver], &mdb->mhash[hash]);
  	mdb->size++;
  
  out:
  	return mp;
  }
  
  static int br_multicast_add_group(struct net_bridge *br,

  				  struct net_bridge_port *port,
  				  struct br_ip *group)

  {
  	struct net_bridge_mdb_entry *mp;
  	struct net_bridge_port_group *p;

  	struct net_bridge_port_group __rcu **pp;

  	unsigned long now = jiffies;
  	int err;

  	spin_lock(&br->multicast_lock);
  	if (!netif_running(br->dev) ||
  	    (port && port->state == BR_STATE_DISABLED))
  		goto out;
  
  	mp = br_multicast_new_group(br, port, group);
  	err = PTR_ERR(mp);

  	if (IS_ERR(mp))

  		goto err;
  
  	if (!port) {

  		mp->mglist = true;

  		mod_timer(&mp->timer, now + br->multicast_membership_interval);
  		goto out;
  	}

  	for (pp = &mp->ports;
  	     (p = mlock_dereference(*pp, br)) != NULL;
  	     pp = &p->next) {

  		if (p->port == port)
  			goto found;
  		if ((unsigned long)p->port < (unsigned long)port)
  			break;
  	}
  
  	p = kzalloc(sizeof(*p), GFP_ATOMIC);
  	err = -ENOMEM;
  	if (unlikely(!p))
  		goto err;

  	p->addr = *group;

  	p->port = port;
  	p->next = *pp;
  	hlist_add_head(&p->mglist, &port->mglist);
  	setup_timer(&p->timer, br_multicast_port_group_expired,
  		    (unsigned long)p);
  	setup_timer(&p->query_timer, br_multicast_port_group_query_expired,
  		    (unsigned long)p);
  
  	rcu_assign_pointer(*pp, p);
  
  found:
  	mod_timer(&p->timer, now + br->multicast_membership_interval);
  out:
  	err = 0;
  
  err:
  	spin_unlock(&br->multicast_lock);
  	return err;
  }

  static int br_ip4_multicast_add_group(struct net_bridge *br,
  				      struct net_bridge_port *port,
  				      __be32 group)
  {
  	struct br_ip br_group;
  
  	if (ipv4_is_local_multicast(group))
  		return 0;
  
  	br_group.u.ip4 = group;
  	br_group.proto = htons(ETH_P_IP);
  
  	return br_multicast_add_group(br, port, &br_group);
  }

  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  static int br_ip6_multicast_add_group(struct net_bridge *br,
  				      struct net_bridge_port *port,
  				      const struct in6_addr *group)
  {
  	struct br_ip br_group;

  	if (!ipv6_is_transient_multicast(group))

  		return 0;
  
  	ipv6_addr_copy(&br_group.u.ip6, group);

  	br_group.proto = htons(ETH_P_IPV6);

  
  	return br_multicast_add_group(br, port, &br_group);
  }
  #endif

  static void br_multicast_router_expired(unsigned long data)
  {
  	struct net_bridge_port *port = (void *)data;
  	struct net_bridge *br = port->br;
  
  	spin_lock(&br->multicast_lock);
  	if (port->multicast_router != 1 ||
  	    timer_pending(&port->multicast_router_timer) ||
  	    hlist_unhashed(&port->rlist))
  		goto out;
  
  	hlist_del_init_rcu(&port->rlist);
  
  out:
  	spin_unlock(&br->multicast_lock);
  }
  
  static void br_multicast_local_router_expired(unsigned long data)
  {
  }

  static void __br_multicast_send_query(struct net_bridge *br,
  				      struct net_bridge_port *port,
  				      struct br_ip *ip)

  {

  	struct sk_buff *skb;

  	skb = br_multicast_alloc_query(br, ip);

  	if (!skb)

  		return;

  
  	if (port) {
  		__skb_push(skb, sizeof(struct ethhdr));
  		skb->dev = port->dev;

  		NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,

  			dev_queue_xmit);
  	} else
  		netif_rx(skb);

  }
  
  static void br_multicast_send_query(struct net_bridge *br,
  				    struct net_bridge_port *port, u32 sent)
  {
  	unsigned long time;
  	struct br_ip br_group;
  
  	if (!netif_running(br->dev) || br->multicast_disabled ||
  	    timer_pending(&br->multicast_querier_timer))
  		return;

  	memset(&br_group.u, 0, sizeof(br_group.u));

  	br_group.proto = htons(ETH_P_IP);

  	__br_multicast_send_query(br, port, &br_group);

  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  	br_group.proto = htons(ETH_P_IPV6);

  	__br_multicast_send_query(br, port, &br_group);

  #endif

  	time = jiffies;
  	time += sent < br->multicast_startup_query_count ?
  		br->multicast_startup_query_interval :
  		br->multicast_query_interval;
  	mod_timer(port ? &port->multicast_query_timer :
  			 &br->multicast_query_timer, time);
  }
  
  static void br_multicast_port_query_expired(unsigned long data)
  {
  	struct net_bridge_port *port = (void *)data;
  	struct net_bridge *br = port->br;
  
  	spin_lock(&br->multicast_lock);

  	if (port->state == BR_STATE_DISABLED ||
  	    port->state == BR_STATE_BLOCKING)

  		goto out;
  
  	if (port->multicast_startup_queries_sent <
  	    br->multicast_startup_query_count)
  		port->multicast_startup_queries_sent++;
  
  	br_multicast_send_query(port->br, port,
  				port->multicast_startup_queries_sent);
  
  out:
  	spin_unlock(&br->multicast_lock);
  }
  
  void br_multicast_add_port(struct net_bridge_port *port)
  {
  	port->multicast_router = 1;
  
  	setup_timer(&port->multicast_router_timer, br_multicast_router_expired,
  		    (unsigned long)port);
  	setup_timer(&port->multicast_query_timer,
  		    br_multicast_port_query_expired, (unsigned long)port);
  }
  
  void br_multicast_del_port(struct net_bridge_port *port)
  {
  	del_timer_sync(&port->multicast_router_timer);
  }

  static void __br_multicast_enable_port(struct net_bridge_port *port)
  {
  	port->multicast_startup_queries_sent = 0;
  
  	if (try_to_del_timer_sync(&port->multicast_query_timer) >= 0 ||
  	    del_timer(&port->multicast_query_timer))
  		mod_timer(&port->multicast_query_timer, jiffies);
  }

  void br_multicast_enable_port(struct net_bridge_port *port)
  {
  	struct net_bridge *br = port->br;
  
  	spin_lock(&br->multicast_lock);
  	if (br->multicast_disabled || !netif_running(br->dev))
  		goto out;

  	__br_multicast_enable_port(port);

  
  out:
  	spin_unlock(&br->multicast_lock);
  }
  
  void br_multicast_disable_port(struct net_bridge_port *port)
  {
  	struct net_bridge *br = port->br;
  	struct net_bridge_port_group *pg;
  	struct hlist_node *p, *n;
  
  	spin_lock(&br->multicast_lock);
  	hlist_for_each_entry_safe(pg, p, n, &port->mglist, mglist)
  		br_multicast_del_pg(br, pg);
  
  	if (!hlist_unhashed(&port->rlist))
  		hlist_del_init_rcu(&port->rlist);
  	del_timer(&port->multicast_router_timer);
  	del_timer(&port->multicast_query_timer);
  	spin_unlock(&br->multicast_lock);
  }

  static int br_ip4_multicast_igmp3_report(struct net_bridge *br,
  					 struct net_bridge_port *port,
  					 struct sk_buff *skb)

  {
  	struct igmpv3_report *ih;
  	struct igmpv3_grec *grec;
  	int i;
  	int len;
  	int num;
  	int type;
  	int err = 0;
  	__be32 group;
  
  	if (!pskb_may_pull(skb, sizeof(*ih)))
  		return -EINVAL;
  
  	ih = igmpv3_report_hdr(skb);
  	num = ntohs(ih->ngrec);
  	len = sizeof(*ih);
  
  	for (i = 0; i < num; i++) {
  		len += sizeof(*grec);
  		if (!pskb_may_pull(skb, len))
  			return -EINVAL;

  		grec = (void *)(skb->data + len - sizeof(*grec));

  		group = grec->grec_mca;
  		type = grec->grec_type;

  		len += ntohs(grec->grec_nsrcs) * 4;

  		if (!pskb_may_pull(skb, len))
  			return -EINVAL;
  
  		/* We treat this as an IGMPv2 report for now. */
  		switch (type) {
  		case IGMPV3_MODE_IS_INCLUDE:
  		case IGMPV3_MODE_IS_EXCLUDE:
  		case IGMPV3_CHANGE_TO_INCLUDE:
  		case IGMPV3_CHANGE_TO_EXCLUDE:
  		case IGMPV3_ALLOW_NEW_SOURCES:
  		case IGMPV3_BLOCK_OLD_SOURCES:
  			break;
  
  		default:
  			continue;
  		}

  		err = br_ip4_multicast_add_group(br, port, group);

  		if (err)
  			break;
  	}
  
  	return err;
  }

  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  static int br_ip6_multicast_mld2_report(struct net_bridge *br,
  					struct net_bridge_port *port,
  					struct sk_buff *skb)
  {
  	struct icmp6hdr *icmp6h;
  	struct mld2_grec *grec;
  	int i;
  	int len;
  	int num;
  	int err = 0;
  
  	if (!pskb_may_pull(skb, sizeof(*icmp6h)))
  		return -EINVAL;
  
  	icmp6h = icmp6_hdr(skb);
  	num = ntohs(icmp6h->icmp6_dataun.un_data16[1]);
  	len = sizeof(*icmp6h);
  
  	for (i = 0; i < num; i++) {
  		__be16 *nsrcs, _nsrcs;
  
  		nsrcs = skb_header_pointer(skb,
  					   len + offsetof(struct mld2_grec,

  							  grec_nsrcs),

  					   sizeof(_nsrcs), &_nsrcs);
  		if (!nsrcs)
  			return -EINVAL;
  
  		if (!pskb_may_pull(skb,
  				   len + sizeof(*grec) +

  				   sizeof(struct in6_addr) * ntohs(*nsrcs)))

  			return -EINVAL;
  
  		grec = (struct mld2_grec *)(skb->data + len);

  		len += sizeof(*grec) +
  		       sizeof(struct in6_addr) * ntohs(*nsrcs);

  
  		/* We treat these as MLDv1 reports for now. */
  		switch (grec->grec_type) {
  		case MLD2_MODE_IS_INCLUDE:
  		case MLD2_MODE_IS_EXCLUDE:
  		case MLD2_CHANGE_TO_INCLUDE:
  		case MLD2_CHANGE_TO_EXCLUDE:
  		case MLD2_ALLOW_NEW_SOURCES:
  		case MLD2_BLOCK_OLD_SOURCES:
  			break;
  
  		default:
  			continue;
  		}
  
  		err = br_ip6_multicast_add_group(br, port, &grec->grec_mca);
  		if (!err)
  			break;
  	}
  
  	return err;
  }
  #endif

  /*
   * Add port to rotuer_list
   *  list is maintained ordered by pointer value
   *  and locked by br->multicast_lock and RCU
   */

  static void br_multicast_add_router(struct net_bridge *br,
  				    struct net_bridge_port *port)
  {

  	struct net_bridge_port *p;

  	struct hlist_node *n, *slot = NULL;

  	hlist_for_each_entry(p, n, &br->router_list, rlist) {

  		if ((unsigned long) port >= (unsigned long) p)
  			break;
  		slot = n;

  	}

  	if (slot)
  		hlist_add_after_rcu(slot, &port->rlist);

  	else
  		hlist_add_head_rcu(&port->rlist, &br->router_list);

  }

  static void br_multicast_mark_router(struct net_bridge *br,
  				     struct net_bridge_port *port)
  {
  	unsigned long now = jiffies;

  
  	if (!port) {
  		if (br->multicast_router == 1)
  			mod_timer(&br->multicast_router_timer,
  				  now + br->multicast_querier_interval);
  		return;
  	}
  
  	if (port->multicast_router != 1)
  		return;
  
  	if (!hlist_unhashed(&port->rlist))
  		goto timer;

  	br_multicast_add_router(br, port);

  
  timer:
  	mod_timer(&port->multicast_router_timer,
  		  now + br->multicast_querier_interval);
  }
  
  static void br_multicast_query_received(struct net_bridge *br,
  					struct net_bridge_port *port,

  					int saddr)

  {
  	if (saddr)
  		mod_timer(&br->multicast_querier_timer,
  			  jiffies + br->multicast_querier_interval);
  	else if (timer_pending(&br->multicast_querier_timer))
  		return;
  
  	br_multicast_mark_router(br, port);
  }

  static int br_ip4_multicast_query(struct net_bridge *br,
  				  struct net_bridge_port *port,
  				  struct sk_buff *skb)

  {
  	struct iphdr *iph = ip_hdr(skb);
  	struct igmphdr *ih = igmp_hdr(skb);
  	struct net_bridge_mdb_entry *mp;
  	struct igmpv3_query *ih3;
  	struct net_bridge_port_group *p;

  	struct net_bridge_port_group __rcu **pp;

  	unsigned long max_delay;
  	unsigned long now = jiffies;
  	__be32 group;

  	int err = 0;

  
  	spin_lock(&br->multicast_lock);
  	if (!netif_running(br->dev) ||
  	    (port && port->state == BR_STATE_DISABLED))
  		goto out;

  	br_multicast_query_received(br, port, !!iph->saddr);

  
  	group = ih->group;
  
  	if (skb->len == sizeof(*ih)) {
  		max_delay = ih->code * (HZ / IGMP_TIMER_SCALE);
  
  		if (!max_delay) {
  			max_delay = 10 * HZ;
  			group = 0;
  		}
  	} else {

  		if (!pskb_may_pull(skb, sizeof(struct igmpv3_query))) {
  			err = -EINVAL;
  			goto out;
  		}

  
  		ih3 = igmpv3_query_hdr(skb);
  		if (ih3->nsrcs)

  			goto out;

  		max_delay = ih3->code ?
  			    IGMPV3_MRC(ih3->code) * (HZ / IGMP_TIMER_SCALE) : 1;

  	}
  
  	if (!group)
  		goto out;

  	mp = br_mdb_ip4_get(mlock_dereference(br->mdb, br), group);

  	if (!mp)
  		goto out;
  
  	max_delay *= br->multicast_last_member_count;

  	if (mp->mglist &&

  	    (timer_pending(&mp->timer) ?
  	     time_after(mp->timer.expires, now + max_delay) :
  	     try_to_del_timer_sync(&mp->timer) >= 0))
  		mod_timer(&mp->timer, now + max_delay);

  	for (pp = &mp->ports;
  	     (p = mlock_dereference(*pp, br)) != NULL;
  	     pp = &p->next) {

  		if (timer_pending(&p->timer) ?
  		    time_after(p->timer.expires, now + max_delay) :
  		    try_to_del_timer_sync(&p->timer) >= 0)

  			mod_timer(&p->timer, now + max_delay);

  	}
  
  out:
  	spin_unlock(&br->multicast_lock);

  	return err;

  }

  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  static int br_ip6_multicast_query(struct net_bridge *br,
  				  struct net_bridge_port *port,
  				  struct sk_buff *skb)
  {
  	struct ipv6hdr *ip6h = ipv6_hdr(skb);
  	struct mld_msg *mld = (struct mld_msg *) icmp6_hdr(skb);
  	struct net_bridge_mdb_entry *mp;
  	struct mld2_query *mld2q;

  	struct net_bridge_port_group *p;
  	struct net_bridge_port_group __rcu **pp;

  	unsigned long max_delay;
  	unsigned long now = jiffies;
  	struct in6_addr *group = NULL;
  	int err = 0;
  
  	spin_lock(&br->multicast_lock);
  	if (!netif_running(br->dev) ||
  	    (port && port->state == BR_STATE_DISABLED))
  		goto out;
  
  	br_multicast_query_received(br, port, !ipv6_addr_any(&ip6h->saddr));
  
  	if (skb->len == sizeof(*mld)) {
  		if (!pskb_may_pull(skb, sizeof(*mld))) {
  			err = -EINVAL;
  			goto out;
  		}
  		mld = (struct mld_msg *) icmp6_hdr(skb);
  		max_delay = msecs_to_jiffies(htons(mld->mld_maxdelay));
  		if (max_delay)
  			group = &mld->mld_mca;
  	} else if (skb->len >= sizeof(*mld2q)) {
  		if (!pskb_may_pull(skb, sizeof(*mld2q))) {
  			err = -EINVAL;
  			goto out;
  		}
  		mld2q = (struct mld2_query *)icmp6_hdr(skb);
  		if (!mld2q->mld2q_nsrcs)
  			group = &mld2q->mld2q_mca;
  		max_delay = mld2q->mld2q_mrc ? MLDV2_MRC(mld2q->mld2q_mrc) : 1;
  	}
  
  	if (!group)
  		goto out;

  	mp = br_mdb_ip6_get(mlock_dereference(br->mdb, br), group);

  	if (!mp)
  		goto out;
  
  	max_delay *= br->multicast_last_member_count;

  	if (mp->mglist &&

  	    (timer_pending(&mp->timer) ?
  	     time_after(mp->timer.expires, now + max_delay) :
  	     try_to_del_timer_sync(&mp->timer) >= 0))
  		mod_timer(&mp->timer, now + max_delay);

  	for (pp = &mp->ports;
  	     (p = mlock_dereference(*pp, br)) != NULL;
  	     pp = &p->next) {

  		if (timer_pending(&p->timer) ?
  		    time_after(p->timer.expires, now + max_delay) :
  		    try_to_del_timer_sync(&p->timer) >= 0)

  			mod_timer(&p->timer, now + max_delay);

  	}
  
  out:
  	spin_unlock(&br->multicast_lock);
  	return err;
  }
  #endif

  static void br_multicast_leave_group(struct net_bridge *br,
  				     struct net_bridge_port *port,

  				     struct br_ip *group)

  {
  	struct net_bridge_mdb_htable *mdb;
  	struct net_bridge_mdb_entry *mp;
  	struct net_bridge_port_group *p;
  	unsigned long now;
  	unsigned long time;

  	spin_lock(&br->multicast_lock);
  	if (!netif_running(br->dev) ||
  	    (port && port->state == BR_STATE_DISABLED) ||
  	    timer_pending(&br->multicast_querier_timer))
  		goto out;

  	mdb = mlock_dereference(br->mdb, br);

  	mp = br_mdb_ip_get(mdb, group);
  	if (!mp)
  		goto out;
  
  	now = jiffies;
  	time = now + br->multicast_last_member_count *
  		     br->multicast_last_member_interval;
  
  	if (!port) {

  		if (mp->mglist &&

  		    (timer_pending(&mp->timer) ?
  		     time_after(mp->timer.expires, time) :
  		     try_to_del_timer_sync(&mp->timer) >= 0)) {
  			mod_timer(&mp->timer, time);
  
  			mp->queries_sent = 0;
  			mod_timer(&mp->query_timer, now);
  		}
  
  		goto out;
  	}

  	for (p = mlock_dereference(mp->ports, br);
  	     p != NULL;
  	     p = mlock_dereference(p->next, br)) {

  		if (p->port != port)
  			continue;
  
  		if (!hlist_unhashed(&p->mglist) &&
  		    (timer_pending(&p->timer) ?
  		     time_after(p->timer.expires, time) :
  		     try_to_del_timer_sync(&p->timer) >= 0)) {
  			mod_timer(&p->timer, time);
  
  			p->queries_sent = 0;
  			mod_timer(&p->query_timer, now);
  		}
  
  		break;
  	}
  
  out:
  	spin_unlock(&br->multicast_lock);
  }

  static void br_ip4_multicast_leave_group(struct net_bridge *br,
  					 struct net_bridge_port *port,
  					 __be32 group)
  {
  	struct br_ip br_group;
  
  	if (ipv4_is_local_multicast(group))
  		return;
  
  	br_group.u.ip4 = group;
  	br_group.proto = htons(ETH_P_IP);
  
  	br_multicast_leave_group(br, port, &br_group);
  }

  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  static void br_ip6_multicast_leave_group(struct net_bridge *br,
  					 struct net_bridge_port *port,
  					 const struct in6_addr *group)
  {
  	struct br_ip br_group;

  	if (!ipv6_is_transient_multicast(group))

  		return;
  
  	ipv6_addr_copy(&br_group.u.ip6, group);
  	br_group.proto = htons(ETH_P_IPV6);
  
  	br_multicast_leave_group(br, port, &br_group);
  }
  #endif

  static int br_multicast_ipv4_rcv(struct net_bridge *br,
  				 struct net_bridge_port *port,
  				 struct sk_buff *skb)
  {
  	struct sk_buff *skb2 = skb;
  	struct iphdr *iph;
  	struct igmphdr *ih;
  	unsigned len;
  	unsigned offset;
  	int err;

  	/* We treat OOM as packet loss for now. */
  	if (!pskb_may_pull(skb, sizeof(*iph)))
  		return -EINVAL;
  
  	iph = ip_hdr(skb);
  
  	if (iph->ihl < 5 || iph->version != 4)
  		return -EINVAL;
  
  	if (!pskb_may_pull(skb, ip_hdrlen(skb)))
  		return -EINVAL;
  
  	iph = ip_hdr(skb);
  
  	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
  		return -EINVAL;
  
  	if (iph->protocol != IPPROTO_IGMP)
  		return 0;
  
  	len = ntohs(iph->tot_len);
  	if (skb->len < len || len < ip_hdrlen(skb))
  		return -EINVAL;
  
  	if (skb->len > len) {
  		skb2 = skb_clone(skb, GFP_ATOMIC);
  		if (!skb2)
  			return -ENOMEM;
  
  		err = pskb_trim_rcsum(skb2, len);
  		if (err)

  			goto err_out;

  	}
  
  	len -= ip_hdrlen(skb2);
  	offset = skb_network_offset(skb2) + ip_hdrlen(skb2);
  	__skb_pull(skb2, offset);
  	skb_reset_transport_header(skb2);
  
  	err = -EINVAL;
  	if (!pskb_may_pull(skb2, sizeof(*ih)))
  		goto out;

  	switch (skb2->ip_summed) {
  	case CHECKSUM_COMPLETE:
  		if (!csum_fold(skb2->csum))
  			break;
  		/* fall through */
  	case CHECKSUM_NONE:
  		skb2->csum = 0;
  		if (skb_checksum_complete(skb2))

  			goto out;

  	}
  
  	err = 0;
  
  	BR_INPUT_SKB_CB(skb)->igmp = 1;
  	ih = igmp_hdr(skb2);
  
  	switch (ih->type) {
  	case IGMP_HOST_MEMBERSHIP_REPORT:
  	case IGMPV2_HOST_MEMBERSHIP_REPORT:
  		BR_INPUT_SKB_CB(skb2)->mrouters_only = 1;

  		err = br_ip4_multicast_add_group(br, port, ih->group);

  		break;
  	case IGMPV3_HOST_MEMBERSHIP_REPORT:

  		err = br_ip4_multicast_igmp3_report(br, port, skb2);

  		break;
  	case IGMP_HOST_MEMBERSHIP_QUERY:

  		err = br_ip4_multicast_query(br, port, skb2);

  		break;
  	case IGMP_HOST_LEAVE_MESSAGE:

  		br_ip4_multicast_leave_group(br, port, ih->group);

  		break;
  	}
  
  out:
  	__skb_push(skb2, offset);

  err_out:

  	if (skb2 != skb)
  		kfree_skb(skb2);
  	return err;
  }

  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  static int br_multicast_ipv6_rcv(struct net_bridge *br,
  				 struct net_bridge_port *port,
  				 struct sk_buff *skb)
  {

  	struct sk_buff *skb2;

  	struct ipv6hdr *ip6h;
  	struct icmp6hdr *icmp6h;
  	u8 nexthdr;
  	unsigned len;

  	int offset;

  	int err;

  	if (!pskb_may_pull(skb, sizeof(*ip6h)))
  		return -EINVAL;
  
  	ip6h = ipv6_hdr(skb);
  
  	/*
  	 * We're interested in MLD messages only.
  	 *  - Version is 6
  	 *  - MLD has always Router Alert hop-by-hop option
  	 *  - But we do not support jumbrograms.
  	 */
  	if (ip6h->version != 6 ||
  	    ip6h->nexthdr != IPPROTO_HOPOPTS ||
  	    ip6h->payload_len == 0)
  		return 0;
  
  	len = ntohs(ip6h->payload_len);
  	if (skb->len < len)
  		return -EINVAL;
  
  	nexthdr = ip6h->nexthdr;
  	offset = ipv6_skip_exthdr(skb, sizeof(*ip6h), &nexthdr);
  
  	if (offset < 0 || nexthdr != IPPROTO_ICMPV6)
  		return 0;
  
  	/* Okay, we found ICMPv6 header */
  	skb2 = skb_clone(skb, GFP_ATOMIC);
  	if (!skb2)
  		return -ENOMEM;

  	err = -EINVAL;
  	if (!pskb_may_pull(skb2, offset + sizeof(struct icmp6hdr)))
  		goto out;

  	len -= offset - skb_network_offset(skb2);
  
  	__skb_pull(skb2, offset);
  	skb_reset_transport_header(skb2);

  	icmp6h = icmp6_hdr(skb2);
  
  	switch (icmp6h->icmp6_type) {
  	case ICMPV6_MGM_QUERY:
  	case ICMPV6_MGM_REPORT:
  	case ICMPV6_MGM_REDUCTION:
  	case ICMPV6_MLD2_REPORT:
  		break;
  	default:
  		err = 0;
  		goto out;
  	}
  
  	/* Okay, we found MLD message. Check further. */
  	if (skb2->len > len) {
  		err = pskb_trim_rcsum(skb2, len);
  		if (err)
  			goto out;
  	}
  
  	switch (skb2->ip_summed) {
  	case CHECKSUM_COMPLETE:
  		if (!csum_fold(skb2->csum))
  			break;
  		/*FALLTHROUGH*/
  	case CHECKSUM_NONE:
  		skb2->csum = 0;
  		if (skb_checksum_complete(skb2))
  			goto out;
  	}
  
  	err = 0;
  
  	BR_INPUT_SKB_CB(skb)->igmp = 1;
  
  	switch (icmp6h->icmp6_type) {
  	case ICMPV6_MGM_REPORT:
  	    {

  		struct mld_msg *mld;
  		if (!pskb_may_pull(skb2, sizeof(*mld))) {
  			err = -EINVAL;
  			goto out;
  		}
  		mld = (struct mld_msg *)skb_transport_header(skb2);

  		BR_INPUT_SKB_CB(skb2)->mrouters_only = 1;
  		err = br_ip6_multicast_add_group(br, port, &mld->mld_mca);
  		break;
  	    }
  	case ICMPV6_MLD2_REPORT:
  		err = br_ip6_multicast_mld2_report(br, port, skb2);
  		break;
  	case ICMPV6_MGM_QUERY:
  		err = br_ip6_multicast_query(br, port, skb2);
  		break;
  	case ICMPV6_MGM_REDUCTION:
  	    {

  		struct mld_msg *mld;
  		if (!pskb_may_pull(skb2, sizeof(*mld))) {
  			err = -EINVAL;
  			goto out;
  		}
  		mld = (struct mld_msg *)skb_transport_header(skb2);

  		br_ip6_multicast_leave_group(br, port, &mld->mld_mca);
  	    }
  	}
  
  out:

  	kfree_skb(skb2);

  	return err;
  }
  #endif

  int br_multicast_rcv(struct net_bridge *br, struct net_bridge_port *port,
  		     struct sk_buff *skb)
  {

  	BR_INPUT_SKB_CB(skb)->igmp = 0;
  	BR_INPUT_SKB_CB(skb)->mrouters_only = 0;

  	if (br->multicast_disabled)
  		return 0;
  
  	switch (skb->protocol) {
  	case htons(ETH_P_IP):
  		return br_multicast_ipv4_rcv(br, port, skb);

  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  	case htons(ETH_P_IPV6):
  		return br_multicast_ipv6_rcv(br, port, skb);
  #endif

  	}
  
  	return 0;
  }
  
  static void br_multicast_query_expired(unsigned long data)
  {
  	struct net_bridge *br = (void *)data;
  
  	spin_lock(&br->multicast_lock);
  	if (br->multicast_startup_queries_sent <
  	    br->multicast_startup_query_count)
  		br->multicast_startup_queries_sent++;
  
  	br_multicast_send_query(br, NULL, br->multicast_startup_queries_sent);
  
  	spin_unlock(&br->multicast_lock);
  }
  
  void br_multicast_init(struct net_bridge *br)
  {
  	br->hash_elasticity = 4;
  	br->hash_max = 512;
  
  	br->multicast_router = 1;
  	br->multicast_last_member_count = 2;
  	br->multicast_startup_query_count = 2;
  
  	br->multicast_last_member_interval = HZ;
  	br->multicast_query_response_interval = 10 * HZ;
  	br->multicast_startup_query_interval = 125 * HZ / 4;
  	br->multicast_query_interval = 125 * HZ;
  	br->multicast_querier_interval = 255 * HZ;
  	br->multicast_membership_interval = 260 * HZ;
  
  	spin_lock_init(&br->multicast_lock);
  	setup_timer(&br->multicast_router_timer,
  		    br_multicast_local_router_expired, 0);
  	setup_timer(&br->multicast_querier_timer,
  		    br_multicast_local_router_expired, 0);
  	setup_timer(&br->multicast_query_timer, br_multicast_query_expired,
  		    (unsigned long)br);
  }
  
  void br_multicast_open(struct net_bridge *br)
  {
  	br->multicast_startup_queries_sent = 0;
  
  	if (br->multicast_disabled)
  		return;
  
  	mod_timer(&br->multicast_query_timer, jiffies);
  }
  
  void br_multicast_stop(struct net_bridge *br)
  {
  	struct net_bridge_mdb_htable *mdb;
  	struct net_bridge_mdb_entry *mp;
  	struct hlist_node *p, *n;
  	u32 ver;
  	int i;
  
  	del_timer_sync(&br->multicast_router_timer);
  	del_timer_sync(&br->multicast_querier_timer);
  	del_timer_sync(&br->multicast_query_timer);
  
  	spin_lock_bh(&br->multicast_lock);

  	mdb = mlock_dereference(br->mdb, br);

  	if (!mdb)
  		goto out;
  
  	br->mdb = NULL;
  
  	ver = mdb->ver;
  	for (i = 0; i < mdb->max; i++) {
  		hlist_for_each_entry_safe(mp, p, n, &mdb->mhash[i],
  					  hlist[ver]) {
  			del_timer(&mp->timer);
  			del_timer(&mp->query_timer);
  			call_rcu_bh(&mp->rcu, br_multicast_free_group);
  		}
  	}
  
  	if (mdb->old) {
  		spin_unlock_bh(&br->multicast_lock);

  		rcu_barrier_bh();

  		spin_lock_bh(&br->multicast_lock);
  		WARN_ON(mdb->old);
  	}
  
  	mdb->old = mdb;
  	call_rcu_bh(&mdb->rcu, br_mdb_free);
  
  out:
  	spin_unlock_bh(&br->multicast_lock);
  }

  
  int br_multicast_set_router(struct net_bridge *br, unsigned long val)
  {
  	int err = -ENOENT;
  
  	spin_lock_bh(&br->multicast_lock);
  	if (!netif_running(br->dev))
  		goto unlock;
  
  	switch (val) {
  	case 0:
  	case 2:
  		del_timer(&br->multicast_router_timer);
  		/* fall through */
  	case 1:
  		br->multicast_router = val;
  		err = 0;
  		break;
  
  	default:
  		err = -EINVAL;
  		break;
  	}
  
  unlock:
  	spin_unlock_bh(&br->multicast_lock);
  
  	return err;
  }
  
  int br_multicast_set_port_router(struct net_bridge_port *p, unsigned long val)
  {
  	struct net_bridge *br = p->br;
  	int err = -ENOENT;
  
  	spin_lock(&br->multicast_lock);
  	if (!netif_running(br->dev) || p->state == BR_STATE_DISABLED)
  		goto unlock;
  
  	switch (val) {
  	case 0:
  	case 1:
  	case 2:
  		p->multicast_router = val;
  		err = 0;
  
  		if (val < 2 && !hlist_unhashed(&p->rlist))
  			hlist_del_init_rcu(&p->rlist);
  
  		if (val == 1)
  			break;
  
  		del_timer(&p->multicast_router_timer);
  
  		if (val == 0)
  			break;
  
  		br_multicast_add_router(br, p);
  		break;
  
  	default:
  		err = -EINVAL;
  		break;
  	}
  
  unlock:
  	spin_unlock(&br->multicast_lock);
  
  	return err;
  }

  
  int br_multicast_toggle(struct net_bridge *br, unsigned long val)
  {
  	struct net_bridge_port *port;

  	int err = 0;

  	struct net_bridge_mdb_htable *mdb;

  
  	spin_lock(&br->multicast_lock);

  	if (br->multicast_disabled == !val)
  		goto unlock;
  
  	br->multicast_disabled = !val;
  	if (br->multicast_disabled)
  		goto unlock;

  	if (!netif_running(br->dev))
  		goto unlock;

  	mdb = mlock_dereference(br->mdb, br);
  	if (mdb) {
  		if (mdb->old) {

  			err = -EEXIST;
  rollback:
  			br->multicast_disabled = !!val;
  			goto unlock;
  		}

  		err = br_mdb_rehash(&br->mdb, mdb->max,

  				    br->hash_elasticity);
  		if (err)
  			goto rollback;
  	}
  
  	br_multicast_open(br);
  	list_for_each_entry(port, &br->port_list, list) {
  		if (port->state == BR_STATE_DISABLED ||
  		    port->state == BR_STATE_BLOCKING)
  			continue;
  
  		__br_multicast_enable_port(port);
  	}
  
  unlock:
  	spin_unlock(&br->multicast_lock);
  
  	return err;
  }

  
  int br_multicast_set_hash_max(struct net_bridge *br, unsigned long val)
  {
  	int err = -ENOENT;
  	u32 old;

  	struct net_bridge_mdb_htable *mdb;

  
  	spin_lock(&br->multicast_lock);
  	if (!netif_running(br->dev))
  		goto unlock;
  
  	err = -EINVAL;
  	if (!is_power_of_2(val))
  		goto unlock;

  
  	mdb = mlock_dereference(br->mdb, br);
  	if (mdb && val < mdb->size)

  		goto unlock;
  
  	err = 0;
  
  	old = br->hash_max;
  	br->hash_max = val;

  	if (mdb) {
  		if (mdb->old) {

  			err = -EEXIST;
  rollback:
  			br->hash_max = old;
  			goto unlock;
  		}
  
  		err = br_mdb_rehash(&br->mdb, br->hash_max,
  				    br->hash_elasticity);
  		if (err)
  			goto rollback;
  	}
  
  unlock:
  	spin_unlock(&br->multicast_lock);
  
  	return err;
  }