Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / net / bridge / br_multicast.c
diff --git a/kernel/net/bridge/br_multicast.c b/kernel/net/bridge/br_multicast.c
new file mode 100644 (file)
index 0000000..ff667e1
--- /dev/null
@@ -0,0 +1,2301 @@
+/*
+ * 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/export.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 <linux/inetdevice.h>
+#include <net/ip.h>
+#if IS_ENABLED(CONFIG_IPV6)
+#include <net/ipv6.h>
+#include <net/mld.h>
+#include <net/ip6_checksum.h>
+#include <net/addrconf.h>
+#endif
+
+#include "br_private.h"
+
+static void br_multicast_start_querier(struct net_bridge *br,
+                                      struct bridge_mcast_own_query *query);
+unsigned int br_mdb_rehash_seq;
+
+static inline int br_ip_equal(const struct br_ip *a, const struct br_ip *b)
+{
+       if (a->proto != b->proto)
+               return 0;
+       if (a->vid != b->vid)
+               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,
+                               __u16 vid)
+{
+       return jhash_2words((__force u32)ip, vid, mdb->secret) & (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,
+                               __u16 vid)
+{
+       return jhash_2words(ipv6_addr_hash(ip), vid,
+                           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, ip->vid);
+#if IS_ENABLED(CONFIG_IPV6)
+       case htons(ETH_P_IPV6):
+               return __br_ip6_hash(mdb, &ip->u.ip6, ip->vid);
+#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;
+
+       hlist_for_each_entry_rcu(mp, &mdb->mhash[hash], hlist[mdb->ver]) {
+               if (br_ip_equal(&mp->addr, dst))
+                       return mp;
+       }
+
+       return NULL;
+}
+
+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, __u16 vid)
+{
+       struct br_ip br_dst;
+
+       br_dst.u.ip4 = dst;
+       br_dst.proto = htons(ETH_P_IP);
+       br_dst.vid = vid;
+
+       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,
+       __u16 vid)
+{
+       struct br_ip br_dst;
+
+       br_dst.u.ip6 = *dst;
+       br_dst.proto = htons(ETH_P_IPV6);
+       br_dst.vid = vid;
+
+       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, u16 vid)
+{
+       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;
+       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(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;
+       int maxlen;
+       int len;
+       int i;
+
+       for (i = 0; i < old->max; i++)
+               hlist_for_each_entry(mp, &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, &new->mhash[i], hlist[new->ver])
+                       len++;
+               if (len > maxlen)
+                       maxlen = len;
+       }
+
+       return maxlen > elasticity ? -EINVAL : 0;
+}
+
+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) || pg->state & MDB_PERMANENT)
+               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;
+       }
+
+       br_mdb_rehash_seq++;
+       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);
+
+       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) + sizeof(*ih) + 4);
+       iph->id = 0;
+       iph->frag_off = htons(IP_DF);
+       iph->ttl = 1;
+       iph->protocol = IPPROTO_IGMP;
+       iph->saddr = br->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);
+       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);
+
+       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 + 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_query_response_interval :
+                       br->multicast_last_member_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;
+       unsigned int count = 0;
+       unsigned int max;
+       int elasticity;
+       int err;
+
+       mdb = rcu_dereference_protected(br->mdb, 1);
+       hlist_for_each_entry(mp, &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;
+}
+
+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;
+}
+
+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 state)
+{
+       struct net_bridge_port_group *p;
+
+       p = kzalloc(sizeof(*p), GFP_ATOMIC);
+       if (unlikely(!p))
+               return NULL;
+
+       p->addr = *group;
+       p->port = port;
+       p->state = state;
+       rcu_assign_pointer(p->next, next);
+       hlist_add_head(&p->mglist, &port->mglist);
+       setup_timer(&p->timer, br_multicast_port_group_expired,
+                   (unsigned long)p);
+       return p;
+}
+
+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 = br_multicast_new_port_group(port, group, *pp, MDB_TEMPORARY);
+       if (unlikely(!p))
+               goto err;
+       rcu_assign_pointer(*pp, p);
+       br_mdb_notify(br->dev, port, group, RTM_NEWMDB);
+
+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)
+{
+       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);
+       br_group.vid = vid;
+
+       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,
+                                     __u16 vid)
+{
+       struct br_ip br_group;
+
+       if (ipv6_addr_is_ll_all_nodes(group))
+               return 0;
+
+       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);
+}
+#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(struct net_bridge *br,
+                                        struct bridge_mcast_own_query *query)
+{
+       spin_lock(&br->multicast_lock);
+       if (!netif_running(br->dev) || br->multicast_disabled)
+               goto out;
+
+       br_multicast_start_querier(br, query);
+
+out:
+       spin_unlock(&br->multicast_lock);
+}
+
+static void br_ip4_multicast_querier_expired(unsigned long data)
+{
+       struct net_bridge *br = (void *)data;
+
+       br_multicast_querier_expired(br, &br->ip4_own_query);
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static void br_ip6_multicast_querier_expired(unsigned long data)
+{
+       struct net_bridge *br = (void *)data;
+
+       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;
+
+       skb = br_multicast_alloc_query(br, ip);
+       if (!skb)
+               return;
+
+       if (port) {
+               skb->dev = port->dev;
+               NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, NULL, skb,
+                       NULL, skb->dev,
+                       br_dev_queue_push_xmit);
+       } else {
+               br_multicast_select_own_querier(br, ip, skb);
+               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)
+{
+       unsigned long time;
+       struct br_ip br_group;
+       struct bridge_mcast_other_query *other_query = NULL;
+
+       if (!netif_running(br->dev) || br->multicast_disabled ||
+           !br->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(unsigned long data)
+{
+       struct net_bridge_port *port = (void *)data;
+
+       br_multicast_port_query_expired(port, &port->ip4_own_query);
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static void br_ip6_multicast_port_query_expired(unsigned long data)
+{
+       struct net_bridge_port *port = (void *)data;
+
+       br_multicast_port_query_expired(port, &port->ip6_own_query);
+}
+#endif
+
+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->ip4_own_query.timer,
+                   br_ip4_multicast_port_query_expired, (unsigned long)port);
+#if IS_ENABLED(CONFIG_IPV6)
+       setup_timer(&port->ip6_own_query.timer,
+                   br_ip6_multicast_port_query_expired, (unsigned long)port);
+#endif
+}
+
+void br_multicast_del_port(struct net_bridge_port *port)
+{
+       del_timer_sync(&port->multicast_router_timer);
+}
+
+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);
+}
+
+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->ip4_own_query);
+#if IS_ENABLED(CONFIG_IPV6)
+       br_multicast_enable(&port->ip6_own_query);
+#endif
+
+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 *n;
+
+       spin_lock(&br->multicast_lock);
+       hlist_for_each_entry_safe(pg, 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->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)
+{
+       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, vid);
+               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)
+{
+       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,
+                                                vid);
+               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);
+}
+
+/*
+ * 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);
+}
+
+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;
+
+       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 int br_ip4_multicast_query(struct net_bridge *br,
+                                 struct net_bridge_port *port,
+                                 struct sk_buff *skb,
+                                 u16 vid)
+{
+       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;
+       int err = 0;
+
+       spin_lock(&br->multicast_lock);
+       if (!netif_running(br->dev) ||
+           (port && port->state == BR_STATE_DISABLED))
+               goto out;
+
+       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;
+       }
+
+       /* RFC2236+RFC3376 (IGMPv2+IGMPv3) require the multicast link layer
+        * all-systems destination addresses (224.0.0.1) for general queries
+        */
+       if (!group && iph->daddr != htonl(INADDR_ALLHOSTS_GROUP)) {
+               err = -EINVAL;
+               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(mlock_dereference(br->mdb, br), group, vid);
+       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 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)
+{
+       const struct ipv6hdr *ip6h = ipv6_hdr(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;
+       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;
+
+       /* RFC2710+RFC3810 (MLDv1+MLDv2) require link-local source addresses */
+       if (!(ipv6_addr_type(&ip6h->saddr) & IPV6_ADDR_LINKLOCAL)) {
+               err = -EINVAL;
+               goto out;
+       }
+
+       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(ntohs(mld->mld_maxdelay));
+               if (max_delay)
+                       group = &mld->mld_mca;
+       } else {
+               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 = max(msecs_to_jiffies(mldv2_mrc(mld2q)), 1UL);
+       }
+
+       is_general_query = group && ipv6_addr_any(group);
+
+       /* RFC2710+RFC3810 (MLDv1+MLDv2) require the multicast link layer
+        * all-nodes destination address (ff02::1) for general queries
+        */
+       if (is_general_query && !ipv6_addr_is_ll_all_nodes(&ip6h->daddr)) {
+               err = -EINVAL;
+               goto out;
+       }
+
+       if (is_general_query) {
+               saddr.proto = htons(ETH_P_IPV6);
+               saddr.u.ip6 = ip6h->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(mlock_dereference(br->mdb, br), group, vid);
+       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 bridge_mcast_other_query *other_query,
+                        struct bridge_mcast_own_query *own_query)
+{
+       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(&other_query->timer))
+               goto out;
+
+       mdb = mlock_dereference(br->mdb, br);
+       mp = br_mdb_ip_get(mdb, group);
+       if (!mp)
+               goto out;
+
+       if (br->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 (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;
+               }
+       }
+
+       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 (p->port != port)
+                               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);
+                       br_mdb_notify(br->dev, port, group, RTM_DELMDB);
+
+                       if (!mp->ports && !mp->mglist &&
+                           netif_running(br->dev))
+                               mod_timer(&mp->timer, jiffies);
+               }
+               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);
+               }
+
+               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)
+{
+       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;
+
+       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);
+}
+
+#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)
+{
+       struct br_ip br_group;
+       struct bridge_mcast_own_query *own_query;
+
+       if (ipv6_addr_is_ll_all_nodes(group))
+               return;
+
+       own_query = port ? &port->ip6_own_query : &br->ip6_own_query;
+
+       br_group.u.ip6 = *group;
+       br_group.proto = htons(ETH_P_IPV6);
+       br_group.vid = vid;
+
+       br_multicast_leave_group(br, port, &br_group, &br->ip6_other_query,
+                                own_query);
+}
+#endif
+
+static int br_multicast_ipv4_rcv(struct net_bridge *br,
+                                struct net_bridge_port *port,
+                                struct sk_buff *skb,
+                                u16 vid)
+{
+       struct sk_buff *skb2 = skb;
+       const struct iphdr *iph;
+       struct igmphdr *ih;
+       unsigned int len;
+       unsigned int 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) {
+               if (!ipv4_is_local_multicast(iph->daddr))
+                       BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
+               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(skb)->mrouters_only = 1;
+               err = br_ip4_multicast_add_group(br, port, ih->group, vid);
+               break;
+       case IGMPV3_HOST_MEMBERSHIP_REPORT:
+               err = br_ip4_multicast_igmp3_report(br, port, skb2, vid);
+               break;
+       case IGMP_HOST_MEMBERSHIP_QUERY:
+               err = br_ip4_multicast_query(br, port, skb2, vid);
+               break;
+       case IGMP_HOST_LEAVE_MESSAGE:
+               br_ip4_multicast_leave_group(br, port, ih->group, vid);
+               break;
+       }
+
+out:
+       __skb_push(skb2, offset);
+err_out:
+       if (skb2 != skb)
+               kfree_skb(skb2);
+       return err;
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static int br_multicast_ipv6_rcv(struct net_bridge *br,
+                                struct net_bridge_port *port,
+                                struct sk_buff *skb,
+                                u16 vid)
+{
+       struct sk_buff *skb2;
+       const struct ipv6hdr *ip6h;
+       u8 icmp6_type;
+       u8 nexthdr;
+       __be16 frag_off;
+       unsigned int 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)
+               return 0;
+
+       /* Prevent flooding this packet if there is no listener present */
+       if (!ipv6_addr_is_ll_all_nodes(&ip6h->daddr))
+               BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
+
+       if (ip6h->nexthdr != IPPROTO_HOPOPTS ||
+           ip6h->payload_len == 0)
+               return 0;
+
+       len = ntohs(ip6h->payload_len) + sizeof(*ip6h);
+       if (skb->len < len)
+               return -EINVAL;
+
+       nexthdr = ip6h->nexthdr;
+       offset = ipv6_skip_exthdr(skb, sizeof(*ip6h), &nexthdr, &frag_off);
+
+       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);
+       skb_postpull_rcsum(skb2, skb_network_header(skb2),
+                          skb_network_header_len(skb2));
+
+       icmp6_type = icmp6_hdr(skb2)->icmp6_type;
+
+       switch (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;
+               err = -EINVAL;
+       }
+
+       ip6h = ipv6_hdr(skb2);
+
+       switch (skb2->ip_summed) {
+       case CHECKSUM_COMPLETE:
+               if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, skb2->len,
+                                       IPPROTO_ICMPV6, skb2->csum))
+                       break;
+               /*FALLTHROUGH*/
+       case CHECKSUM_NONE:
+               skb2->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr,
+                                                       &ip6h->daddr,
+                                                       skb2->len,
+                                                       IPPROTO_ICMPV6, 0));
+               if (__skb_checksum_complete(skb2))
+                       goto out;
+       }
+
+       err = 0;
+
+       BR_INPUT_SKB_CB(skb)->igmp = 1;
+
+       switch (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(skb)->mrouters_only = 1;
+               err = br_ip6_multicast_add_group(br, port, &mld->mld_mca, vid);
+               break;
+           }
+       case ICMPV6_MLD2_REPORT:
+               err = br_ip6_multicast_mld2_report(br, port, skb2, vid);
+               break;
+       case ICMPV6_MGM_QUERY:
+               err = br_ip6_multicast_query(br, port, skb2, vid);
+               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, vid);
+           }
+       }
+
+out:
+       kfree_skb(skb2);
+       return err;
+}
+#endif
+
+int br_multicast_rcv(struct net_bridge *br, struct net_bridge_port *port,
+                    struct sk_buff *skb, u16 vid)
+{
+       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, vid);
+#if IS_ENABLED(CONFIG_IPV6)
+       case htons(ETH_P_IPV6):
+               return br_multicast_ipv6_rcv(br, port, skb, vid);
+#endif
+       }
+
+       return 0;
+}
+
+static void br_multicast_query_expired(struct net_bridge *br,
+                                      struct bridge_mcast_own_query *query,
+                                      struct bridge_mcast_querier *querier)
+{
+       spin_lock(&br->multicast_lock);
+       if (query->startup_sent < br->multicast_startup_query_count)
+               query->startup_sent++;
+
+       RCU_INIT_POINTER(querier->port, NULL);
+       br_multicast_send_query(br, NULL, query);
+       spin_unlock(&br->multicast_lock);
+}
+
+static void br_ip4_multicast_query_expired(unsigned long data)
+{
+       struct net_bridge *br = (void *)data;
+
+       br_multicast_query_expired(br, &br->ip4_own_query, &br->ip4_querier);
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static void br_ip6_multicast_query_expired(unsigned long data)
+{
+       struct net_bridge *br = (void *)data;
+
+       br_multicast_query_expired(br, &br->ip6_own_query, &br->ip6_querier);
+}
+#endif
+
+void br_multicast_init(struct net_bridge *br)
+{
+       br->hash_elasticity = 4;
+       br->hash_max = 512;
+
+       br->multicast_router = 1;
+       br->multicast_querier = 0;
+       br->multicast_query_use_ifaddr = 0;
+       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;
+
+       br->ip4_other_query.delay_time = 0;
+       br->ip4_querier.port = NULL;
+#if IS_ENABLED(CONFIG_IPV6)
+       br->ip6_other_query.delay_time = 0;
+       br->ip6_querier.port = NULL;
+#endif
+
+       spin_lock_init(&br->multicast_lock);
+       setup_timer(&br->multicast_router_timer,
+                   br_multicast_local_router_expired, 0);
+       setup_timer(&br->ip4_other_query.timer,
+                   br_ip4_multicast_querier_expired, (unsigned long)br);
+       setup_timer(&br->ip4_own_query.timer, br_ip4_multicast_query_expired,
+                   (unsigned long)br);
+#if IS_ENABLED(CONFIG_IPV6)
+       setup_timer(&br->ip6_other_query.timer,
+                   br_ip6_multicast_querier_expired, (unsigned long)br);
+       setup_timer(&br->ip6_own_query.timer, br_ip6_multicast_query_expired,
+                   (unsigned long)br);
+#endif
+}
+
+static void __br_multicast_open(struct net_bridge *br,
+                               struct bridge_mcast_own_query *query)
+{
+       query->startup_sent = 0;
+
+       if (br->multicast_disabled)
+               return;
+
+       mod_timer(&query->timer, jiffies);
+}
+
+void br_multicast_open(struct net_bridge *br)
+{
+       __br_multicast_open(br, &br->ip4_own_query);
+#if IS_ENABLED(CONFIG_IPV6)
+       __br_multicast_open(br, &br->ip6_own_query);
+#endif
+}
+
+void br_multicast_stop(struct net_bridge *br)
+{
+       struct net_bridge_mdb_htable *mdb;
+       struct net_bridge_mdb_entry *mp;
+       struct hlist_node *n;
+       u32 ver;
+       int i;
+
+       del_timer_sync(&br->multicast_router_timer);
+       del_timer_sync(&br->ip4_other_query.timer);
+       del_timer_sync(&br->ip4_own_query.timer);
+#if IS_ENABLED(CONFIG_IPV6)
+       del_timer_sync(&br->ip6_other_query.timer);
+       del_timer_sync(&br->ip6_own_query.timer);
+#endif
+
+       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, n, &mdb->mhash[i],
+                                         hlist[ver]) {
+                       del_timer(&mp->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;
+}
+
+static void br_multicast_start_querier(struct net_bridge *br,
+                                      struct bridge_mcast_own_query *query)
+{
+       struct net_bridge_port *port;
+
+       __br_multicast_open(br, query);
+
+       list_for_each_entry(port, &br->port_list, list) {
+               if (port->state == BR_STATE_DISABLED ||
+                   port->state == BR_STATE_BLOCKING)
+                       continue;
+
+               if (query == &br->ip4_own_query)
+                       br_multicast_enable(&port->ip4_own_query);
+#if IS_ENABLED(CONFIG_IPV6)
+               else
+                       br_multicast_enable(&port->ip6_own_query);
+#endif
+       }
+}
+
+int br_multicast_toggle(struct net_bridge *br, unsigned long val)
+{
+       int err = 0;
+       struct net_bridge_mdb_htable *mdb;
+
+       spin_lock_bh(&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_start_querier(br, &br->ip4_own_query);
+#if IS_ENABLED(CONFIG_IPV6)
+       br_multicast_start_querier(br, &br->ip6_own_query);
+#endif
+
+unlock:
+       spin_unlock_bh(&br->multicast_lock);
+
+       return err;
+}
+
+int br_multicast_set_querier(struct net_bridge *br, unsigned long val)
+{
+       unsigned long max_delay;
+
+       val = !!val;
+
+       spin_lock_bh(&br->multicast_lock);
+       if (br->multicast_querier == val)
+               goto unlock;
+
+       br->multicast_querier = val;
+       if (!val)
+               goto unlock;
+
+       max_delay = br->multicast_query_response_interval;
+
+       if (!timer_pending(&br->ip4_other_query.timer))
+               br->ip4_other_query.delay_time = jiffies + max_delay;
+
+       br_multicast_start_querier(br, &br->ip4_own_query);
+
+#if IS_ENABLED(CONFIG_IPV6)
+       if (!timer_pending(&br->ip6_other_query.timer))
+               br->ip6_other_query.delay_time = jiffies + max_delay;
+
+       br_multicast_start_querier(br, &br->ip6_own_query);
+#endif
+
+unlock:
+       spin_unlock_bh(&br->multicast_lock);
+
+       return 0;
+}
+
+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_bh(&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_bh(&br->multicast_lock);
+
+       return err;
+}
+
+/**
+ * br_multicast_list_adjacent - Returns snooped multicast addresses
+ * @dev:       The bridge port adjacent to which to retrieve addresses
+ * @br_ip_list:        The list to store found, snooped multicast IP addresses in
+ *
+ * Creates a list of IP addresses (struct br_ip_list) sensed by the multicast
+ * snooping feature on all bridge ports of dev's bridge device, excluding
+ * the addresses from dev itself.
+ *
+ * Returns the number of items added to br_ip_list.
+ *
+ * Notes:
+ * - br_ip_list needs to be initialized by caller
+ * - br_ip_list might contain duplicates in the end
+ *   (needs to be taken care of by caller)
+ * - br_ip_list needs to be freed by caller
+ */
+int br_multicast_list_adjacent(struct net_device *dev,
+                              struct list_head *br_ip_list)
+{
+       struct net_bridge *br;
+       struct net_bridge_port *port;
+       struct net_bridge_port_group *group;
+       struct br_ip_list *entry;
+       int count = 0;
+
+       rcu_read_lock();
+       if (!br_ip_list || !br_port_exists(dev))
+               goto unlock;
+
+       port = br_port_get_rcu(dev);
+       if (!port || !port->br)
+               goto unlock;
+
+       br = port->br;
+
+       list_for_each_entry_rcu(port, &br->port_list, list) {
+               if (!port->dev || port->dev == dev)
+                       continue;
+
+               hlist_for_each_entry_rcu(group, &port->mglist, mglist) {
+                       entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
+                       if (!entry)
+                               goto unlock;
+
+                       entry->addr = group->addr;
+                       list_add(&entry->list, br_ip_list);
+                       count++;
+               }
+       }
+
+unlock:
+       rcu_read_unlock();
+       return count;
+}
+EXPORT_SYMBOL_GPL(br_multicast_list_adjacent);
+
+/**
+ * br_multicast_has_querier_anywhere - Checks for a querier on a bridge
+ * @dev: The bridge port providing the bridge on which to check for a querier
+ * @proto: The protocol family to check for: IGMP -> ETH_P_IP, MLD -> ETH_P_IPV6
+ *
+ * Checks whether the given interface has a bridge on top and if so returns
+ * true if a valid querier exists anywhere on the bridged link layer.
+ * Otherwise returns false.
+ */
+bool br_multicast_has_querier_anywhere(struct net_device *dev, int proto)
+{
+       struct net_bridge *br;
+       struct net_bridge_port *port;
+       struct ethhdr eth;
+       bool ret = false;
+
+       rcu_read_lock();
+       if (!br_port_exists(dev))
+               goto unlock;
+
+       port = br_port_get_rcu(dev);
+       if (!port || !port->br)
+               goto unlock;
+
+       br = port->br;
+
+       memset(&eth, 0, sizeof(eth));
+       eth.h_proto = htons(proto);
+
+       ret = br_multicast_querier_exists(br, &eth);
+
+unlock:
+       rcu_read_unlock();
+       return ret;
+}
+EXPORT_SYMBOL_GPL(br_multicast_has_querier_anywhere);
+
+/**
+ * br_multicast_has_querier_adjacent - Checks for a querier behind a bridge port
+ * @dev: The bridge port adjacent to which to check for a querier
+ * @proto: The protocol family to check for: IGMP -> ETH_P_IP, MLD -> ETH_P_IPV6
+ *
+ * Checks whether the given interface has a bridge on top and if so returns
+ * true if a selected querier is behind one of the other ports of this
+ * bridge. Otherwise returns false.
+ */
+bool br_multicast_has_querier_adjacent(struct net_device *dev, int proto)
+{
+       struct net_bridge *br;
+       struct net_bridge_port *port;
+       bool ret = false;
+
+       rcu_read_lock();
+       if (!br_port_exists(dev))
+               goto unlock;
+
+       port = br_port_get_rcu(dev);
+       if (!port || !port->br)
+               goto unlock;
+
+       br = port->br;
+
+       switch (proto) {
+       case ETH_P_IP:
+               if (!timer_pending(&br->ip4_other_query.timer) ||
+                   rcu_dereference(br->ip4_querier.port) == port)
+                       goto unlock;
+               break;
+#if IS_ENABLED(CONFIG_IPV6)
+       case ETH_P_IPV6:
+               if (!timer_pending(&br->ip6_other_query.timer) ||
+                   rcu_dereference(br->ip6_querier.port) == port)
+                       goto unlock;
+               break;
+#endif
+       default:
+               goto unlock;
+       }
+
+       ret = true;
+unlock:
+       rcu_read_unlock();
+       return ret;
+}
+EXPORT_SYMBOL_GPL(br_multicast_has_querier_adjacent);