// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   * Bridge multicast support.
   *
   * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>

   */
  
  #include <linux/err.h>

  #include <linux/export.h>

  #include <linux/if_ether.h>
  #include <linux/igmp.h>

  #include <linux/in.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 <linux/inetdevice.h>

  #include <linux/mroute.h>

  #include <net/ip.h>

  #include <net/switchdev.h>

  #if IS_ENABLED(CONFIG_IPV6)

  #include <linux/icmpv6.h>

  #include <net/ipv6.h>
  #include <net/mld.h>

  #include <net/ip6_checksum.h>

  #include <net/addrconf.h>

  #endif

  
  #include "br_private.h"

  static const struct rhashtable_params br_mdb_rht_params = {
  	.head_offset = offsetof(struct net_bridge_mdb_entry, rhnode),
  	.key_offset = offsetof(struct net_bridge_mdb_entry, addr),
  	.key_len = sizeof(struct br_ip),
  	.automatic_shrinking = true,

  };

  static void br_multicast_start_querier(struct net_bridge *br,

  				       struct bridge_mcast_own_query *query);

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

  static void br_ip4_multicast_leave_group(struct net_bridge *br,
  					 struct net_bridge_port *port,
  					 __be32 group,

  					 __u16 vid,
  					 const unsigned char *src);

  static void __del_port_router(struct net_bridge_port *p);

  #if IS_ENABLED(CONFIG_IPV6)
  static void br_ip6_multicast_leave_group(struct net_bridge *br,
  					 struct net_bridge_port *port,
  					 const struct in6_addr *group,

  					 __u16 vid, const unsigned char *src);

  #endif

  static struct net_bridge_mdb_entry *br_mdb_ip_get_rcu(struct net_bridge *br,
  						      struct br_ip *dst)

  {

  	return rhashtable_lookup(&br->mdb_hash_tbl, dst, br_mdb_rht_params);

  }

  struct net_bridge_mdb_entry *br_mdb_ip_get(struct net_bridge *br,
  					   struct br_ip *dst)

  {

  	struct net_bridge_mdb_entry *ent;

  	lockdep_assert_held_once(&br->multicast_lock);

  	rcu_read_lock();
  	ent = rhashtable_lookup(&br->mdb_hash_tbl, dst, br_mdb_rht_params);
  	rcu_read_unlock();

  	return ent;

  }

  static struct net_bridge_mdb_entry *br_mdb_ip4_get(struct net_bridge *br,
  						   __be32 dst, __u16 vid)

  {

  	struct br_ip br_dst;

  	memset(&br_dst, 0, sizeof(br_dst));

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

  	br_dst.vid = vid;

  	return br_mdb_ip_get(br, &br_dst);

  }

  #if IS_ENABLED(CONFIG_IPV6)

  static struct net_bridge_mdb_entry *br_mdb_ip6_get(struct net_bridge *br,
  						   const struct in6_addr *dst,
  						   __u16 vid)

  {
  	struct br_ip br_dst;

  	memset(&br_dst, 0, sizeof(br_dst));

  	br_dst.u.ip6 = *dst;

  	br_dst.proto = htons(ETH_P_IPV6);

  	br_dst.vid = vid;

  	return br_mdb_ip_get(br, &br_dst);

  }
  #endif

  struct net_bridge_mdb_entry *br_mdb_get(struct net_bridge *br,

  					struct sk_buff *skb, u16 vid)

  {

  	struct br_ip ip;

  	if (!br_opt_get(br, BROPT_MULTICAST_ENABLED))

  		return NULL;

  	if (BR_INPUT_SKB_CB(skb)->igmp)

  		return NULL;

  	memset(&ip, 0, sizeof(ip));

  	ip.proto = skb->protocol;

  	ip.vid = vid;

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

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

  #if IS_ENABLED(CONFIG_IPV6)

  	case htons(ETH_P_IPV6):

  		ip.u.ip6 = ipv6_hdr(skb)->daddr;

  		break;
  #endif

  	default:
  		return NULL;

  	}

  	return br_mdb_ip_get_rcu(br, &ip);

  }

  static void br_multicast_group_expired(struct timer_list *t)

  {

  	struct net_bridge_mdb_entry *mp = from_timer(mp, t, timer);

  	struct net_bridge *br = mp->br;

  
  	spin_lock(&br->multicast_lock);
  	if (!netif_running(br->dev) || timer_pending(&mp->timer))
  		goto out;

  	br_multicast_host_leave(mp, true);

  
  	if (mp->ports)
  		goto out;

  	rhashtable_remove_fast(&br->mdb_hash_tbl, &mp->rhnode,
  			       br_mdb_rht_params);
  	hlist_del_rcu(&mp->mdb_node);

  	kfree_rcu(mp, rcu);

  
  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_entry *mp;
  	struct net_bridge_port_group *p;

  	struct net_bridge_port_group __rcu **pp;

  	mp = br_mdb_ip_get(br, &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);

  		br_mdb_notify(br->dev, p->port, &pg->addr, RTM_DELMDB,
  			      p->flags);

  		kfree_rcu(p, rcu);

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

  		    netif_running(br->dev))
  			mod_timer(&mp->timer, jiffies);
  
  		return;
  	}
  
  	WARN_ON(1);
  }

  static void br_multicast_port_group_expired(struct timer_list *t)

  {

  	struct net_bridge_port_group *pg = from_timer(pg, t, timer);

  	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) || pg->flags & MDB_PG_FLAGS_PERMANENT)

  		goto out;
  
  	br_multicast_del_pg(br, pg);
  
  out:
  	spin_unlock(&br->multicast_lock);
  }

  static struct sk_buff *br_ip4_multicast_alloc_query(struct net_bridge *br,

  						    __be32 group,
  						    u8 *igmp_type)

  {

  	struct igmpv3_query *ihv3;
  	size_t igmp_hdr_size;

  	struct sk_buff *skb;
  	struct igmphdr *ih;
  	struct ethhdr *eth;
  	struct iphdr *iph;

  	igmp_hdr_size = sizeof(*ih);
  	if (br->multicast_igmp_version == 3)
  		igmp_hdr_size = sizeof(*ihv3);

  	skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*iph) +

  						 igmp_hdr_size + 4);

  	if (!skb)
  		goto out;
  
  	skb->protocol = htons(ETH_P_IP);
  
  	skb_reset_mac_header(skb);
  	eth = eth_hdr(skb);

  	ether_addr_copy(eth->h_source, br->dev->dev_addr);

  	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) + igmp_hdr_size + 4);

  	iph->id = 0;
  	iph->frag_off = htons(IP_DF);
  	iph->ttl = 1;
  	iph->protocol = IPPROTO_IGMP;

  	iph->saddr = br_opt_get(br, BROPT_MULTICAST_QUERY_USE_IFADDR) ?

  		     inet_select_addr(br->dev, 0, RT_SCOPE_LINK) : 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);

  	*igmp_type = IGMP_HOST_MEMBERSHIP_QUERY;

  	switch (br->multicast_igmp_version) {
  	case 2:
  		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(*ih));
  		break;
  	case 3:
  		ihv3 = igmpv3_query_hdr(skb);
  		ihv3->type = IGMP_HOST_MEMBERSHIP_QUERY;
  		ihv3->code = (group ? br->multicast_last_member_interval :
  				      br->multicast_query_response_interval) /
  			     (HZ / IGMP_TIMER_SCALE);
  		ihv3->group = group;
  		ihv3->qqic = br->multicast_query_interval / HZ;
  		ihv3->nsrcs = 0;
  		ihv3->resv = 0;
  		ihv3->suppress = 0;
  		ihv3->qrv = 2;
  		ihv3->csum = 0;
  		ihv3->csum = ip_compute_csum((void *)ihv3, sizeof(*ihv3));
  		break;
  	}
  
  	skb_put(skb, igmp_hdr_size);

  	__skb_pull(skb, sizeof(*eth));
  
  out:
  	return skb;
  }

  #if IS_ENABLED(CONFIG_IPV6)

  static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,

  						    const struct in6_addr *grp,
  						    u8 *igmp_type)

  {

  	struct mld2_query *mld2q;
  	unsigned long interval;

  	struct ipv6hdr *ip6h;
  	struct mld_msg *mldq;

  	size_t mld_hdr_size;
  	struct sk_buff *skb;

  	struct ethhdr *eth;
  	u8 *hopopt;

  	mld_hdr_size = sizeof(*mldq);
  	if (br->multicast_mld_version == 2)
  		mld_hdr_size = sizeof(*mld2q);

  	skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*ip6h) +

  						 8 + mld_hdr_size);

  	if (!skb)
  		goto out;
  
  	skb->protocol = htons(ETH_P_IPV6);
  
  	/* Ethernet header */
  	skb_reset_mac_header(skb);
  	eth = eth_hdr(skb);

  	ether_addr_copy(eth->h_source, br->dev->dev_addr);

  	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 + mld_hdr_size);

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

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

  	if (ipv6_dev_get_saddr(dev_net(br->dev), br->dev, &ip6h->daddr, 0,
  			       &ip6h->saddr)) {
  		kfree_skb(skb);

  		br_opt_toggle(br, BROPT_HAS_IPV6_ADDR, false);

  		return NULL;
  	}

  	br_opt_toggle(br, BROPT_HAS_IPV6_ADDR, true);

  	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_PAD1;		/* Pad1 */
  	hopopt[7] = IPV6_TLV_PAD1;		/* Pad1 */

  
  	skb_put(skb, sizeof(*ip6h) + 8);
  
  	/* ICMPv6 */
  	skb_set_transport_header(skb, skb->len);

  	interval = ipv6_addr_any(grp) ?

  			br->multicast_query_response_interval :
  			br->multicast_last_member_interval;

  	*igmp_type = ICMPV6_MGM_QUERY;

  	switch (br->multicast_mld_version) {
  	case 1:
  		mldq = (struct mld_msg *)icmp6_hdr(skb);
  		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;
  		mldq->mld_mca = *grp;
  		mldq->mld_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
  						  sizeof(*mldq), IPPROTO_ICMPV6,
  						  csum_partial(mldq,
  							       sizeof(*mldq),
  							       0));
  		break;
  	case 2:
  		mld2q = (struct mld2_query *)icmp6_hdr(skb);

  		mld2q->mld2q_mrc = htons((u16)jiffies_to_msecs(interval));

  		mld2q->mld2q_type = ICMPV6_MGM_QUERY;
  		mld2q->mld2q_code = 0;
  		mld2q->mld2q_cksum = 0;
  		mld2q->mld2q_resv1 = 0;
  		mld2q->mld2q_resv2 = 0;
  		mld2q->mld2q_suppress = 0;
  		mld2q->mld2q_qrv = 2;
  		mld2q->mld2q_nsrcs = 0;
  		mld2q->mld2q_qqic = br->multicast_query_interval / HZ;
  		mld2q->mld2q_mca = *grp;
  		mld2q->mld2q_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
  						     sizeof(*mld2q),
  						     IPPROTO_ICMPV6,
  						     csum_partial(mld2q,
  								  sizeof(*mld2q),
  								  0));
  		break;
  	}
  	skb_put(skb, mld_hdr_size);

  
  	__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,
  						u8 *igmp_type)

  {
  	switch (addr->proto) {
  	case htons(ETH_P_IP):

  		return br_ip4_multicast_alloc_query(br, addr->u.ip4, igmp_type);

  #if IS_ENABLED(CONFIG_IPV6)

  	case htons(ETH_P_IPV6):

  		return br_ip6_multicast_alloc_query(br, &addr->u.ip6,
  						    igmp_type);

  #endif

  	}
  	return NULL;
  }

  struct net_bridge_mdb_entry *br_multicast_new_group(struct net_bridge *br,

  						    struct br_ip *group)

  {

  	struct net_bridge_mdb_entry *mp;

  	int err;

  	mp = br_mdb_ip_get(br, group);
  	if (mp)
  		return mp;

  	if (atomic_read(&br->mdb_hash_tbl.nelems) >= br->hash_max) {
  		br_opt_toggle(br, BROPT_MULTICAST_ENABLED, false);
  		return ERR_PTR(-E2BIG);

  	}
  
  	mp = kzalloc(sizeof(*mp), GFP_ATOMIC);
  	if (unlikely(!mp))

  		return ERR_PTR(-ENOMEM);

  
  	mp->br = br;

  	mp->addr = *group;

  	timer_setup(&mp->timer, br_multicast_group_expired, 0);

  	err = rhashtable_lookup_insert_fast(&br->mdb_hash_tbl, &mp->rhnode,
  					    br_mdb_rht_params);
  	if (err) {
  		kfree(mp);
  		mp = ERR_PTR(err);
  	} else {
  		hlist_add_head_rcu(&mp->mdb_node, &br->mdb_list);
  	}

  	return mp;
  }

  struct net_bridge_port_group *br_multicast_new_port_group(
  			struct net_bridge_port *port,
  			struct br_ip *group,

  			struct net_bridge_port_group __rcu *next,

  			unsigned char flags,
  			const unsigned char *src)

  {
  	struct net_bridge_port_group *p;
  
  	p = kzalloc(sizeof(*p), GFP_ATOMIC);
  	if (unlikely(!p))
  		return NULL;
  
  	p->addr = *group;
  	p->port = port;

  	p->flags = flags;

  	rcu_assign_pointer(p->next, next);

  	hlist_add_head(&p->mglist, &port->mglist);

  	timer_setup(&p->timer, br_multicast_port_group_expired, 0);

  
  	if (src)
  		memcpy(p->eth_addr, src, ETH_ALEN);
  	else

  		eth_broadcast_addr(p->eth_addr);

  	return p;
  }

  static bool br_port_group_equal(struct net_bridge_port_group *p,
  				struct net_bridge_port *port,
  				const unsigned char *src)
  {
  	if (p->port != port)
  		return false;
  
  	if (!(port->flags & BR_MULTICAST_TO_UNICAST))
  		return true;
  
  	return ether_addr_equal(src, p->eth_addr);
  }

  void br_multicast_host_join(struct net_bridge_mdb_entry *mp, bool notify)
  {
  	if (!mp->host_joined) {
  		mp->host_joined = true;
  		if (notify)
  			br_mdb_notify(mp->br->dev, NULL, &mp->addr,
  				      RTM_NEWMDB, 0);
  	}
  	mod_timer(&mp->timer, jiffies + mp->br->multicast_membership_interval);
  }
  
  void br_multicast_host_leave(struct net_bridge_mdb_entry *mp, bool notify)
  {
  	if (!mp->host_joined)
  		return;
  
  	mp->host_joined = false;
  	if (notify)
  		br_mdb_notify(mp->br->dev, NULL, &mp->addr, RTM_DELMDB, 0);
  }

  static int br_multicast_add_group(struct net_bridge *br,

  				  struct net_bridge_port *port,

  				  struct br_ip *group,
  				  const unsigned char *src)

  {

  	struct net_bridge_port_group __rcu **pp;

  	struct net_bridge_port_group *p;
  	struct net_bridge_mdb_entry *mp;

  	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, group);

  	err = PTR_ERR(mp);

  	if (IS_ERR(mp))

  		goto err;
  
  	if (!port) {

  		br_multicast_host_join(mp, true);

  		goto out;
  	}

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

  		if (br_port_group_equal(p, port, src))

  			goto found;

  		if ((unsigned long)p->port < (unsigned long)port)
  			break;
  	}

  	p = br_multicast_new_port_group(port, group, *pp, 0, src);

  	if (unlikely(!p))
  		goto err;

  	rcu_assign_pointer(*pp, p);

  	br_mdb_notify(br->dev, port, group, RTM_NEWMDB, 0);

  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,

  				      __u16 vid,
  				      const unsigned char *src)

  {
  	struct br_ip br_group;
  
  	if (ipv4_is_local_multicast(group))
  		return 0;

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

  	br_group.u.ip4 = group;
  	br_group.proto = htons(ETH_P_IP);

  	br_group.vid = vid;

  	return br_multicast_add_group(br, port, &br_group, src);

  }

  #if IS_ENABLED(CONFIG_IPV6)

  static int br_ip6_multicast_add_group(struct net_bridge *br,
  				      struct net_bridge_port *port,

  				      const struct in6_addr *group,

  				      __u16 vid,
  				      const unsigned char *src)

  {
  	struct br_ip br_group;

  	if (ipv6_addr_is_ll_all_nodes(group))

  		return 0;

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

  	br_group.u.ip6 = *group;

  	br_group.proto = htons(ETH_P_IPV6);

  	br_group.vid = vid;

  	return br_multicast_add_group(br, port, &br_group, src);

  }
  #endif

  static void br_multicast_router_expired(struct timer_list *t)

  {

  	struct net_bridge_port *port =
  			from_timer(port, t, multicast_router_timer);

  	struct net_bridge *br = port->br;
  
  	spin_lock(&br->multicast_lock);

  	if (port->multicast_router == MDB_RTR_TYPE_DISABLED ||
  	    port->multicast_router == MDB_RTR_TYPE_PERM ||

  	    timer_pending(&port->multicast_router_timer))

  		goto out;

  	__del_port_router(port);

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

  static void br_mc_router_state_change(struct net_bridge *p,
  				      bool is_mc_router)
  {
  	struct switchdev_attr attr = {
  		.orig_dev = p->dev,
  		.id = SWITCHDEV_ATTR_ID_BRIDGE_MROUTER,
  		.flags = SWITCHDEV_F_DEFER,
  		.u.mrouter = is_mc_router,
  	};
  
  	switchdev_port_attr_set(p->dev, &attr);
  }

  static void br_multicast_local_router_expired(struct timer_list *t)

  {

  	struct net_bridge *br = from_timer(br, t, multicast_router_timer);

  
  	spin_lock(&br->multicast_lock);
  	if (br->multicast_router == MDB_RTR_TYPE_DISABLED ||
  	    br->multicast_router == MDB_RTR_TYPE_PERM ||
  	    timer_pending(&br->multicast_router_timer))
  		goto out;
  
  	br_mc_router_state_change(br, false);
  out:
  	spin_unlock(&br->multicast_lock);

  }

  static void br_multicast_querier_expired(struct net_bridge *br,

  					 struct bridge_mcast_own_query *query)

  {

  	spin_lock(&br->multicast_lock);

  	if (!netif_running(br->dev) || !br_opt_get(br, BROPT_MULTICAST_ENABLED))

  		goto out;

  	br_multicast_start_querier(br, query);

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

  static void br_ip4_multicast_querier_expired(struct timer_list *t)

  {

  	struct net_bridge *br = from_timer(br, t, ip4_other_query.timer);

  	br_multicast_querier_expired(br, &br->ip4_own_query);

  }
  
  #if IS_ENABLED(CONFIG_IPV6)

  static void br_ip6_multicast_querier_expired(struct timer_list *t)

  {

  	struct net_bridge *br = from_timer(br, t, ip6_other_query.timer);

  	br_multicast_querier_expired(br, &br->ip6_own_query);

  }
  #endif

  static void br_multicast_select_own_querier(struct net_bridge *br,
  					    struct br_ip *ip,
  					    struct sk_buff *skb)
  {
  	if (ip->proto == htons(ETH_P_IP))
  		br->ip4_querier.addr.u.ip4 = ip_hdr(skb)->saddr;
  #if IS_ENABLED(CONFIG_IPV6)
  	else
  		br->ip6_querier.addr.u.ip6 = ipv6_hdr(skb)->saddr;
  #endif
  }

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

  {

  	struct sk_buff *skb;

  	u8 igmp_type;

  	skb = br_multicast_alloc_query(br, ip, &igmp_type);

  	if (!skb)

  		return;

  
  	if (port) {

  		skb->dev = port->dev;

  		br_multicast_count(br, port, skb, igmp_type,

  				   BR_MCAST_DIR_TX);

  		NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT,
  			dev_net(port->dev), NULL, skb, NULL, skb->dev,

  			br_dev_queue_push_xmit);

  	} else {
  		br_multicast_select_own_querier(br, ip, skb);

  		br_multicast_count(br, port, skb, igmp_type,

  				   BR_MCAST_DIR_RX);

  		netif_rx(skb);

  	}

  }
  
  static void br_multicast_send_query(struct net_bridge *br,

  				    struct net_bridge_port *port,

  				    struct bridge_mcast_own_query *own_query)

  {

  	struct bridge_mcast_other_query *other_query = NULL;

  	struct br_ip br_group;
  	unsigned long time;

  	if (!netif_running(br->dev) ||
  	    !br_opt_get(br, BROPT_MULTICAST_ENABLED) ||

  	    !br_opt_get(br, BROPT_MULTICAST_QUERIER))

  		return;

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

  	if (port ? (own_query == &port->ip4_own_query) :
  		   (own_query == &br->ip4_own_query)) {
  		other_query = &br->ip4_other_query;

  		br_group.proto = htons(ETH_P_IP);

  #if IS_ENABLED(CONFIG_IPV6)

  	} else {

  		other_query = &br->ip6_other_query;

  		br_group.proto = htons(ETH_P_IPV6);

  #endif

  	}

  	if (!other_query || timer_pending(&other_query->timer))

  		return;
  
  	__br_multicast_send_query(br, port, &br_group);

  	time = jiffies;

  	time += own_query->startup_sent < br->multicast_startup_query_count ?

  		br->multicast_startup_query_interval :
  		br->multicast_query_interval;

  	mod_timer(&own_query->timer, time);

  }

  static void
  br_multicast_port_query_expired(struct net_bridge_port *port,
  				struct bridge_mcast_own_query *query)

  {

  	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 (query->startup_sent < br->multicast_startup_query_count)
  		query->startup_sent++;

  	br_multicast_send_query(port->br, port, query);

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

  static void br_ip4_multicast_port_query_expired(struct timer_list *t)

  {

  	struct net_bridge_port *port = from_timer(port, t, ip4_own_query.timer);

  	br_multicast_port_query_expired(port, &port->ip4_own_query);

  }
  
  #if IS_ENABLED(CONFIG_IPV6)

  static void br_ip6_multicast_port_query_expired(struct timer_list *t)

  {

  	struct net_bridge_port *port = from_timer(port, t, ip6_own_query.timer);

  	br_multicast_port_query_expired(port, &port->ip6_own_query);

  }
  #endif

  static void br_mc_disabled_update(struct net_device *dev, bool value)
  {
  	struct switchdev_attr attr = {
  		.orig_dev = dev,
  		.id = SWITCHDEV_ATTR_ID_BRIDGE_MC_DISABLED,
  		.flags = SWITCHDEV_F_DEFER,

  		.u.mc_disabled = !value,

  	};
  
  	switchdev_port_attr_set(dev, &attr);
  }

  int br_multicast_add_port(struct net_bridge_port *port)

  {

  	port->multicast_router = MDB_RTR_TYPE_TEMP_QUERY;

  	timer_setup(&port->multicast_router_timer,
  		    br_multicast_router_expired, 0);
  	timer_setup(&port->ip4_own_query.timer,
  		    br_ip4_multicast_port_query_expired, 0);

  #if IS_ENABLED(CONFIG_IPV6)

  	timer_setup(&port->ip6_own_query.timer,
  		    br_ip6_multicast_port_query_expired, 0);

  #endif

  	br_mc_disabled_update(port->dev,
  			      br_opt_get(port->br, BROPT_MULTICAST_ENABLED));

  	port->mcast_stats = netdev_alloc_pcpu_stats(struct bridge_mcast_stats);
  	if (!port->mcast_stats)
  		return -ENOMEM;
  
  	return 0;

  }
  
  void br_multicast_del_port(struct net_bridge_port *port)
  {

  	struct net_bridge *br = port->br;
  	struct net_bridge_port_group *pg;
  	struct hlist_node *n;
  
  	/* Take care of the remaining groups, only perm ones should be left */
  	spin_lock_bh(&br->multicast_lock);
  	hlist_for_each_entry_safe(pg, n, &port->mglist, mglist)
  		br_multicast_del_pg(br, pg);
  	spin_unlock_bh(&br->multicast_lock);

  	del_timer_sync(&port->multicast_router_timer);

  	free_percpu(port->mcast_stats);

  }

  static void br_multicast_enable(struct bridge_mcast_own_query *query)

  {

  	query->startup_sent = 0;

  	if (try_to_del_timer_sync(&query->timer) >= 0 ||
  	    del_timer(&query->timer))
  		mod_timer(&query->timer, jiffies);

  }

  static void __br_multicast_enable_port(struct net_bridge_port *port)

  {
  	struct net_bridge *br = port->br;

  	if (!br_opt_get(br, BROPT_MULTICAST_ENABLED) || !netif_running(br->dev))

  		return;

  	br_multicast_enable(&port->ip4_own_query);

  #if IS_ENABLED(CONFIG_IPV6)

  	br_multicast_enable(&port->ip6_own_query);

  #endif

  	if (port->multicast_router == MDB_RTR_TYPE_PERM &&
  	    hlist_unhashed(&port->rlist))

  		br_multicast_add_router(br, port);

  }

  void br_multicast_enable_port(struct net_bridge_port *port)
  {
  	struct net_bridge *br = port->br;
  
  	spin_lock(&br->multicast_lock);
  	__br_multicast_enable_port(port);

  	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 *n;

  
  	spin_lock(&br->multicast_lock);

  	hlist_for_each_entry_safe(pg, n, &port->mglist, mglist)

  		if (!(pg->flags & MDB_PG_FLAGS_PERMANENT))

  			br_multicast_del_pg(br, pg);

  	__del_port_router(port);

  	del_timer(&port->multicast_router_timer);

  	del_timer(&port->ip4_own_query.timer);

  #if IS_ENABLED(CONFIG_IPV6)

  	del_timer(&port->ip6_own_query.timer);

  #endif

  	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,
  					 u16 vid)

  {

  	const unsigned char *src;

  	struct igmpv3_report *ih;
  	struct igmpv3_grec *grec;
  	int i;
  	int len;
  	int num;
  	int type;
  	int err = 0;
  	__be32 group;

  	u16 nsrcs;

  	ih = igmpv3_report_hdr(skb);
  	num = ntohs(ih->ngrec);

  	len = skb_transport_offset(skb) + sizeof(*ih);

  
  	for (i = 0; i < num; i++) {
  		len += sizeof(*grec);

  		if (!ip_mc_may_pull(skb, len))

  			return -EINVAL;

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

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

  		nsrcs = ntohs(grec->grec_nsrcs);

  		len += nsrcs * 4;

  		if (!ip_mc_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;
  		}

  		src = eth_hdr(skb)->h_source;

  		if ((type == IGMPV3_CHANGE_TO_INCLUDE ||
  		     type == IGMPV3_MODE_IS_INCLUDE) &&

  		    nsrcs == 0) {

  			br_ip4_multicast_leave_group(br, port, group, vid, src);

  		} else {

  			err = br_ip4_multicast_add_group(br, port, group, vid,
  							 src);

  			if (err)
  				break;
  		}

  	}
  
  	return err;
  }

  #if IS_ENABLED(CONFIG_IPV6)

  static int br_ip6_multicast_mld2_report(struct net_bridge *br,
  					struct net_bridge_port *port,

  					struct sk_buff *skb,
  					u16 vid)

  {

  	unsigned int nsrcs_offset;

  	const unsigned char *src;

  	struct icmp6hdr *icmp6h;
  	struct mld2_grec *grec;

  	unsigned int grec_len;

  	int i;
  	int len;
  	int num;
  	int err = 0;

  	if (!ipv6_mc_may_pull(skb, sizeof(*icmp6h)))

  		return -EINVAL;
  
  	icmp6h = icmp6_hdr(skb);
  	num = ntohs(icmp6h->icmp6_dataun.un_data16[1]);

  	len = skb_transport_offset(skb) + sizeof(*icmp6h);

  
  	for (i = 0; i < num; i++) {

  		__be16 *_nsrcs, __nsrcs;
  		u16 nsrcs;

  		nsrcs_offset = len + offsetof(struct mld2_grec, grec_nsrcs);
  
  		if (skb_transport_offset(skb) + ipv6_transport_len(skb) <

  		    nsrcs_offset + sizeof(__nsrcs))

  			return -EINVAL;

  		_nsrcs = skb_header_pointer(skb, nsrcs_offset,
  					    sizeof(__nsrcs), &__nsrcs);
  		if (!_nsrcs)

  			return -EINVAL;

  		nsrcs = ntohs(*_nsrcs);
  		grec_len = struct_size(grec, grec_src, nsrcs);

  
  		if (!ipv6_mc_may_pull(skb, len + grec_len))

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

  		len += grec_len;

  
  		/* 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;
  		}

  		src = eth_hdr(skb)->h_source;

  		if ((grec->grec_type == MLD2_CHANGE_TO_INCLUDE ||
  		     grec->grec_type == MLD2_MODE_IS_INCLUDE) &&

  		    nsrcs == 0) {

  			br_ip6_multicast_leave_group(br, port, &grec->grec_mca,

  						     vid, src);

  		} else {
  			err = br_ip6_multicast_add_group(br, port,

  							 &grec->grec_mca, vid,
  							 src);

  			if (err)

  				break;
  		}

  	}
  
  	return err;
  }
  #endif

  static bool br_ip4_multicast_select_querier(struct net_bridge *br,

  					    struct net_bridge_port *port,

  					    __be32 saddr)
  {
  	if (!timer_pending(&br->ip4_own_query.timer) &&
  	    !timer_pending(&br->ip4_other_query.timer))
  		goto update;
  
  	if (!br->ip4_querier.addr.u.ip4)
  		goto update;
  
  	if (ntohl(saddr) <= ntohl(br->ip4_querier.addr.u.ip4))
  		goto update;
  
  	return false;
  
  update:
  	br->ip4_querier.addr.u.ip4 = saddr;

  	/* update protected by general multicast_lock by caller */
  	rcu_assign_pointer(br->ip4_querier.port, port);

  	return true;
  }
  
  #if IS_ENABLED(CONFIG_IPV6)
  static bool br_ip6_multicast_select_querier(struct net_bridge *br,

  					    struct net_bridge_port *port,

  					    struct in6_addr *saddr)
  {
  	if (!timer_pending(&br->ip6_own_query.timer) &&
  	    !timer_pending(&br->ip6_other_query.timer))
  		goto update;
  
  	if (ipv6_addr_cmp(saddr, &br->ip6_querier.addr.u.ip6) <= 0)
  		goto update;
  
  	return false;
  
  update:
  	br->ip6_querier.addr.u.ip6 = *saddr;

  	/* update protected by general multicast_lock by caller */
  	rcu_assign_pointer(br->ip6_querier.port, port);

  	return true;
  }
  #endif
  
  static bool br_multicast_select_querier(struct net_bridge *br,

  					struct net_bridge_port *port,

  					struct br_ip *saddr)
  {
  	switch (saddr->proto) {
  	case htons(ETH_P_IP):

  		return br_ip4_multicast_select_querier(br, port, saddr->u.ip4);

  #if IS_ENABLED(CONFIG_IPV6)
  	case htons(ETH_P_IPV6):

  		return br_ip6_multicast_select_querier(br, port, &saddr->u.ip6);

  #endif
  	}
  
  	return false;
  }

  static void

  br_multicast_update_query_timer(struct net_bridge *br,
  				struct bridge_mcast_other_query *query,
  				unsigned long max_delay)

  {

  	if (!timer_pending(&query->timer))
  		query->delay_time = jiffies + max_delay;

  	mod_timer(&query->timer, jiffies + br->multicast_querier_interval);

  }

  static void br_port_mc_router_state_change(struct net_bridge_port *p,
  					   bool is_mc_router)
  {
  	struct switchdev_attr attr = {
  		.orig_dev = p->dev,
  		.id = SWITCHDEV_ATTR_ID_PORT_MROUTER,
  		.flags = SWITCHDEV_F_DEFER,
  		.u.mrouter = is_mc_router,
  	};
  
  	switchdev_port_attr_set(p->dev, &attr);
  }

  /*

   * Add port to router_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 *slot = NULL;

  	if (!hlist_unhashed(&port->rlist))
  		return;

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

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

  		slot = &p->rlist;

  	}

  	if (slot)

  		hlist_add_behind_rcu(&port->rlist, slot);

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

  	br_rtr_notify(br->dev, port, RTM_NEWMDB);

  	br_port_mc_router_state_change(port, true);

  }

  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 == MDB_RTR_TYPE_TEMP_QUERY) {
  			if (!timer_pending(&br->multicast_router_timer))
  				br_mc_router_state_change(br, true);

  			mod_timer(&br->multicast_router_timer,
  				  now + br->multicast_querier_interval);

  		}

  		return;
  	}

  	if (port->multicast_router == MDB_RTR_TYPE_DISABLED ||
  	    port->multicast_router == MDB_RTR_TYPE_PERM)

  		return;

  	br_multicast_add_router(br, port);

  	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,

  					struct bridge_mcast_other_query *query,

  					struct br_ip *saddr,

  					unsigned long max_delay)

  {

  	if (!br_multicast_select_querier(br, port, saddr))

  		return;

  	br_multicast_update_query_timer(br, query, max_delay);

  	br_multicast_mark_router(br, port);

  }

  static void br_ip4_multicast_query(struct net_bridge *br,
  				   struct net_bridge_port *port,
  				   struct sk_buff *skb,
  				   u16 vid)

  {

  	unsigned int transport_len = ip_transport_len(skb);

  	const 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;

  	struct br_ip saddr;

  	unsigned long max_delay;
  	unsigned long now = jiffies;
  	__be32 group;
  
  	spin_lock(&br->multicast_lock);
  	if (!netif_running(br->dev) ||
  	    (port && port->state == BR_STATE_DISABLED))
  		goto out;

  	group = ih->group;

  	if (transport_len == sizeof(*ih)) {

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

  	} else if (transport_len >= sizeof(*ih3)) {

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

  			goto out;

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

  	} else {

  		goto out;
  	}

  	if (!group) {
  		saddr.proto = htons(ETH_P_IP);
  		saddr.u.ip4 = iph->saddr;

  		br_multicast_query_received(br, port, &br->ip4_other_query,
  					    &saddr, max_delay);

  		goto out;

  	}

  	mp = br_mdb_ip4_get(br, group, vid);

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

  	if (mp->host_joined &&

  	    (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);

  }

  #if IS_ENABLED(CONFIG_IPV6)

  static int br_ip6_multicast_query(struct net_bridge *br,
  				  struct net_bridge_port *port,

  				  struct sk_buff *skb,
  				  u16 vid)

  {

  	unsigned int transport_len = ipv6_transport_len(skb);

  	struct mld_msg *mld;

  	struct net_bridge_mdb_entry *mp;
  	struct mld2_query *mld2q;

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

  	struct br_ip saddr;

  	unsigned long max_delay;
  	unsigned long now = jiffies;

  	unsigned int offset = skb_transport_offset(skb);

  	const struct in6_addr *group = NULL;

  	bool is_general_query;

  	int err = 0;
  
  	spin_lock(&br->multicast_lock);
  	if (!netif_running(br->dev) ||
  	    (port && port->state == BR_STATE_DISABLED))
  		goto out;

  	if (transport_len == sizeof(*mld)) {

  		if (!pskb_may_pull(skb, offset + sizeof(*mld))) {

  			err = -EINVAL;
  			goto out;
  		}
  		mld = (struct mld_msg *) icmp6_hdr(skb);

  		max_delay = msecs_to_jiffies(ntohs(mld->mld_maxdelay));

  		if (max_delay)
  			group = &mld->mld_mca;

  	} else {

  		if (!pskb_may_pull(skb, offset + sizeof(*mld2q))) {

  			err = -EINVAL;
  			goto out;
  		}
  		mld2q = (struct mld2_query *)icmp6_hdr(skb);
  		if (!mld2q->mld2q_nsrcs)
  			group = &mld2q->mld2q_mca;

  
  		max_delay = max(msecs_to_jiffies(mldv2_mrc(mld2q)), 1UL);

  	}

  	is_general_query = group && ipv6_addr_any(group);

  	if (is_general_query) {
  		saddr.proto = htons(ETH_P_IPV6);

  		saddr.u.ip6 = ipv6_hdr(skb)->saddr;

  		br_multicast_query_received(br, port, &br->ip6_other_query,
  					    &saddr, max_delay);

  		goto out;

  	} else if (!group) {
  		goto out;

  	}

  	mp = br_mdb_ip6_get(br, group, vid);

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

  	if (mp->host_joined &&

  	    (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 bridge_mcast_other_query *other_query,

  			 struct bridge_mcast_own_query *own_query,
  			 const unsigned char *src)

  {

  	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))

  		goto out;

  	mp = br_mdb_ip_get(br, group);

  	if (!mp)
  		goto out;

  	if (port && (port->flags & BR_MULTICAST_FAST_LEAVE)) {
  		struct net_bridge_port_group __rcu **pp;
  
  		for (pp = &mp->ports;
  		     (p = mlock_dereference(*pp, br)) != NULL;
  		     pp = &p->next) {

  			if (!br_port_group_equal(p, port, src))

  				continue;

  			if (p->flags & MDB_PG_FLAGS_PERMANENT)
  				break;

  			rcu_assign_pointer(*pp, p->next);
  			hlist_del_init(&p->mglist);
  			del_timer(&p->timer);

  			kfree_rcu(p, rcu);

  			br_mdb_notify(br->dev, port, group, RTM_DELMDB,

  				      p->flags | MDB_PG_FLAGS_FAST_LEAVE);

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

  			    netif_running(br->dev))
  				mod_timer(&mp->timer, jiffies);
  		}
  		goto out;
  	}
  
  	if (timer_pending(&other_query->timer))
  		goto out;

  	if (br_opt_get(br, BROPT_MULTICAST_QUERIER)) {

  		__br_multicast_send_query(br, port, &mp->addr);
  
  		time = jiffies + br->multicast_last_member_count *
  				 br->multicast_last_member_interval;

  		mod_timer(&own_query->timer, time);

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

  			if (!br_port_group_equal(p, port, src))

  				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);
  			}
  
  			break;
  		}
  	}

  	now = jiffies;
  	time = now + br->multicast_last_member_count *
  		     br->multicast_last_member_interval;
  
  	if (!port) {

  		if (mp->host_joined &&

  		    (timer_pending(&mp->timer) ?
  		     time_after(mp->timer.expires, time) :
  		     try_to_del_timer_sync(&mp->timer) >= 0)) {
  			mod_timer(&mp->timer, time);

  		}

  
  		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);
  		}
  
  		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,

  					 __u16 vid,
  					 const unsigned char *src)

  {
  	struct br_ip br_group;

  	struct bridge_mcast_own_query *own_query;

  
  	if (ipv4_is_local_multicast(group))
  		return;

  	own_query = port ? &port->ip4_own_query : &br->ip4_own_query;

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

  	br_group.u.ip4 = group;
  	br_group.proto = htons(ETH_P_IP);

  	br_group.vid = vid;

  	br_multicast_leave_group(br, port, &br_group, &br->ip4_other_query,

  				 own_query, src);