br_multicast.c

/*
 * 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 IS_ENABLED(CONFIG_IPV6)
#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))

static void br_multicast_start_querier(struct net_bridge *br);

#if IS_ENABLED(CONFIG_IPV6)
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 IS_ENABLED(CONFIG_IPV6)
	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 IS_ENABLED(CONFIG_IPV6)
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 IS_ENABLED(CONFIG_IPV6)
	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 IS_ENABLED(CONFIG_IPV6)
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;

	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 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(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--;

	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);
		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 IS_ENABLED(CONFIG_IPV6)
static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
						    const 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_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);
		return NULL;
	}
	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);
	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;
	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 IS_ENABLED(CONFIG_IPV6)
	case htons(ETH_P_IPV6):
		return br_ip6_multicast_alloc_query(br, &addr->u.ip6);
#endif
	}
	return NULL;
}

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 int count = 0;
	unsigned int 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\n",
				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 of %d "
				"reached, disabling snooping: %s\n",
				br->hash_max,
				port ? port->dev->name : br->dev->name);
			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\n",
					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\n",
				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);

	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);

	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 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)
{
	struct br_ip br_group;

	if (!ipv6_is_transient_multicast(group))
		return 0;

	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_querier_expired(unsigned long data)
{
	struct net_bridge *br = (void *)data;

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

	br_multicast_start_querier(br);

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

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 ||
	    !br->multicast_querier ||
	    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 IS_ENABLED(CONFIG_IPV6)
	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 IS_ENABLED(CONFIG_IPV6)
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

/*