diff options
Diffstat (limited to 'net/bridge/br_multicast.c')
| -rw-r--r-- | net/bridge/br_multicast.c | 1780 |
1 files changed, 1780 insertions, 0 deletions
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c new file mode 100644 index 00000000..27ca25ed --- /dev/null +++ b/net/bridge/br_multicast.c @@ -0,0 +1,1780 @@ +/* + * 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)) + +#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_PAD0; /* Pad0 */ + hopopt[7] = IPV6_TLV_PAD0; /* Pad0 */ + + skb_put(skb, sizeof(*ip6h) + 8); + + /* ICMPv6 */ + skb_set_transport_header(skb, skb->len); + mldq = (struct mld_msg *) icmp6_hdr(skb); + + interval = ipv6_addr_any(group) ? br->multicast_last_member_interval : + br->multicast_query_response_interval; + + mldq->mld_type = ICMPV6_MGM_QUERY; + mldq->mld_code = 0; + mldq->mld_cksum = 0; + mldq->mld_maxdelay = htons((u16)jiffies_to_msecs(interval)); + mldq->mld_reserved = 0; + 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 count = 0; + unsigned max; + int elasticity; + int err; + + mdb = rcu_dereference_protected(br->mdb, 1); + hlist_for_each_entry(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) { + count++; + if (unlikely(br_ip_equal(group, &mp->addr))) + return mp; + } + + elasticity = 0; + max = mdb->max; + + if (unlikely(count > br->hash_elasticity && count)) { + if (net_ratelimit()) + br_info(br, "Multicast hash table " + "chain limit reached: %s\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 " + "reached, disabling snooping: %s, %d\n", + port ? port->dev->name : br->dev->name, max); + err = -E2BIG; +disable: + br->multicast_disabled = 1; + goto err; + } + } + + if (max > mdb->max || elasticity) { + if (mdb->old) { + if (net_ratelimit()) + br_info(br, "Multicast hash table " + "on fire: %s\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_send_query(struct net_bridge *br, + struct net_bridge_port *port, + struct br_ip *ip) +{ + struct sk_buff *skb; + + skb = br_multicast_alloc_query(br, ip); + if (!skb) + return; + + if (port) { + __skb_push(skb, sizeof(struct ethhdr)); + skb->dev = port->dev; + NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev, + dev_queue_xmit); + } else + netif_rx(skb); +} + +static void br_multicast_send_query(struct net_bridge *br, + struct net_bridge_port *port, u32 sent) +{ + unsigned long time; + struct br_ip br_group; + + if (!netif_running(br->dev) || br->multicast_disabled || + timer_pending(&br->multicast_querier_timer)) + return; + + memset(&br_group.u, 0, sizeof(br_group.u)); + + br_group.proto = htons(ETH_P_IP); + __br_multicast_send_query(br, port, &br_group); + +#if 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 + +/* + * Add port to rotuer_list + * list is maintained ordered by pointer value + * and locked by br->multicast_lock and RCU + */ +static void br_multicast_add_router(struct net_bridge *br, + struct net_bridge_port *port) +{ + struct net_bridge_port *p; + struct hlist_node *n, *slot = NULL; + + hlist_for_each_entry(p, n, &br->router_list, rlist) { + if ((unsigned long) port >= (unsigned long) p) + break; + slot = n; + } + + if (slot) + hlist_add_after_rcu(slot, &port->rlist); + else + hlist_add_head_rcu(&port->rlist, &br->router_list); +} + +static void br_multicast_mark_router(struct net_bridge *br, + struct net_bridge_port *port) +{ + unsigned long now = jiffies; + + if (!port) { + if (br->multicast_router == 1) + mod_timer(&br->multicast_router_timer, + now + br->multicast_querier_interval); + return; + } + + if (port->multicast_router != 1) + return; + + if (!hlist_unhashed(&port->rlist)) + goto timer; + + br_multicast_add_router(br, port); + +timer: + mod_timer(&port->multicast_router_timer, + now + br->multicast_querier_interval); +} + +static void br_multicast_query_received(struct net_bridge *br, + struct net_bridge_port *port, + int saddr) +{ + if (saddr) + mod_timer(&br->multicast_querier_timer, + jiffies + br->multicast_querier_interval); + else if (timer_pending(&br->multicast_querier_timer)) + return; + + br_multicast_mark_router(br, port); +} + +static int br_ip4_multicast_query(struct net_bridge *br, + struct net_bridge_port *port, + struct sk_buff *skb) +{ + 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; + unsigned long max_delay; + unsigned long now = jiffies; + __be32 group; + int err = 0; + + spin_lock(&br->multicast_lock); + if (!netif_running(br->dev) || + (port && port->state == BR_STATE_DISABLED)) + goto out; + + br_multicast_query_received(br, port, !!iph->saddr); + + group = ih->group; + + if (skb->len == sizeof(*ih)) { + max_delay = ih->code * (HZ / IGMP_TIMER_SCALE); + + if (!max_delay) { + max_delay = 10 * HZ; + group = 0; + } + } else { + if (!pskb_may_pull(skb, sizeof(struct igmpv3_query))) { + err = -EINVAL; + goto out; + } + + ih3 = igmpv3_query_hdr(skb); + if (ih3->nsrcs) + goto out; + + max_delay = ih3->code ? + IGMPV3_MRC(ih3->code) * (HZ / IGMP_TIMER_SCALE) : 1; + } + + if (!group) + goto out; + + mp = br_mdb_ip4_get(mlock_dereference(br->mdb, br), group); + if (!mp) + goto out; + + max_delay *= br->multicast_last_member_count; + + if (mp->mglist && + (timer_pending(&mp->timer) ? + time_after(mp->timer.expires, now + max_delay) : + try_to_del_timer_sync(&mp->timer) >= 0)) + mod_timer(&mp->timer, now + max_delay); + + for (pp = &mp->ports; + (p = mlock_dereference(*pp, br)) != NULL; + pp = &p->next) { + if (timer_pending(&p->timer) ? + time_after(p->timer.expires, now + max_delay) : + try_to_del_timer_sync(&p->timer) >= 0) + mod_timer(&p->timer, now + max_delay); + } + +out: + spin_unlock(&br->multicast_lock); + return err; +} + +#if IS_ENABLED(CONFIG_IPV6) +static int br_ip6_multicast_query(struct net_bridge *br, + struct net_bridge_port *port, + struct sk_buff *skb) +{ + const struct ipv6hdr *ip6h = ipv6_hdr(skb); + struct mld_msg *mld = (struct mld_msg *) icmp6_hdr(skb); + struct net_bridge_mdb_entry *mp; + struct mld2_query *mld2q; + struct net_bridge_port_group *p; + struct net_bridge_port_group __rcu **pp; + unsigned long max_delay; + unsigned long now = jiffies; + const struct in6_addr *group = NULL; + int err = 0; + + spin_lock(&br->multicast_lock); + if (!netif_running(br->dev) || + (port && port->state == BR_STATE_DISABLED)) + goto out; + + br_multicast_query_received(br, port, !ipv6_addr_any(&ip6h->saddr)); + + if (skb->len == sizeof(*mld)) { + if (!pskb_may_pull(skb, sizeof(*mld))) { + err = -EINVAL; + goto out; + } + mld = (struct mld_msg *) icmp6_hdr(skb); + max_delay = msecs_to_jiffies(htons(mld->mld_maxdelay)); + if (max_delay) + group = &mld->mld_mca; + } else if (skb->len >= sizeof(*mld2q)) { + if (!pskb_may_pull(skb, sizeof(*mld2q))) { + err = -EINVAL; + goto out; + } + mld2q = (struct mld2_query *)icmp6_hdr(skb); + if (!mld2q->mld2q_nsrcs) + group = &mld2q->mld2q_mca; + max_delay = mld2q->mld2q_mrc ? MLDV2_MRC(mld2q->mld2q_mrc) : 1; + } + + if (!group) + goto out; + + mp = br_mdb_ip6_get(mlock_dereference(br->mdb, br), group); + if (!mp) + goto out; + + max_delay *= br->multicast_last_member_count; + if (mp->mglist && + (timer_pending(&mp->timer) ? + time_after(mp->timer.expires, now + max_delay) : + try_to_del_timer_sync(&mp->timer) >= 0)) + mod_timer(&mp->timer, now + max_delay); + + for (pp = &mp->ports; + (p = mlock_dereference(*pp, br)) != NULL; + pp = &p->next) { + if (timer_pending(&p->timer) ? + time_after(p->timer.expires, now + max_delay) : + try_to_del_timer_sync(&p->timer) >= 0) + mod_timer(&p->timer, now + max_delay); + } + +out: + spin_unlock(&br->multicast_lock); + return err; +} +#endif + +static void br_multicast_leave_group(struct net_bridge *br, + struct net_bridge_port *port, + struct br_ip *group) +{ + struct net_bridge_mdb_htable *mdb; + struct net_bridge_mdb_entry *mp; + struct net_bridge_port_group *p; + unsigned long now; + unsigned long time; + + spin_lock(&br->multicast_lock); + if (!netif_running(br->dev) || + (port && port->state == BR_STATE_DISABLED) || + timer_pending(&br->multicast_querier_timer)) + goto out; + + mdb = mlock_dereference(br->mdb, br); + mp = br_mdb_ip_get(mdb, group); + if (!mp) + goto out; + + now = jiffies; + time = now + br->multicast_last_member_count * + br->multicast_last_member_interval; + + if (!port) { + if (mp->mglist && + (timer_pending(&mp->timer) ? + time_after(mp->timer.expires, time) : + try_to_del_timer_sync(&mp->timer) >= 0)) { + mod_timer(&mp->timer, time); + } + + 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) +{ + struct br_ip br_group; + + if (ipv4_is_local_multicast(group)) + return; + + br_group.u.ip4 = group; + br_group.proto = htons(ETH_P_IP); + + br_multicast_leave_group(br, port, &br_group); +} + +#if 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) +{ + struct br_ip br_group; + + if (!ipv6_is_transient_multicast(group)) + return; + + br_group.u.ip6 = *group; + br_group.proto = htons(ETH_P_IPV6); + + br_multicast_leave_group(br, port, &br_group); +} +#endif + +static int br_multicast_ipv4_rcv(struct net_bridge *br, + struct net_bridge_port *port, + struct sk_buff *skb) +{ + struct sk_buff *skb2 = skb; + const struct iphdr *iph; + struct igmphdr *ih; + unsigned len; + unsigned offset; + int err; + + /* We treat OOM as packet loss for now. */ + if (!pskb_may_pull(skb, sizeof(*iph))) + return -EINVAL; + + iph = ip_hdr(skb); + + if (iph->ihl < 5 || iph->version != 4) + return -EINVAL; + + if (!pskb_may_pull(skb, ip_hdrlen(skb))) + return -EINVAL; + + iph = ip_hdr(skb); + + if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl))) + return -EINVAL; + + if (iph->protocol != IPPROTO_IGMP) { + if ((iph->daddr & IGMP_LOCAL_GROUP_MASK) != IGMP_LOCAL_GROUP) + 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); + break; + case IGMPV3_HOST_MEMBERSHIP_REPORT: + err = br_ip4_multicast_igmp3_report(br, port, skb2); + break; + case IGMP_HOST_MEMBERSHIP_QUERY: + err = br_ip4_multicast_query(br, port, skb2); + break; + case IGMP_HOST_LEAVE_MESSAGE: + br_ip4_multicast_leave_group(br, port, ih->group); + break; + } + +out: + __skb_push(skb2, offset); +err_out: + if (skb2 != skb) + kfree_skb(skb2); + return err; +} + +#if IS_ENABLED(CONFIG_IPV6) +static int br_multicast_ipv6_rcv(struct net_bridge *br, + struct net_bridge_port *port, + struct sk_buff *skb) +{ + struct sk_buff *skb2; + const struct ipv6hdr *ip6h; + u8 icmp6_type; + u8 nexthdr; + __be16 frag_off; + unsigned len; + int offset; + int err; + + if (!pskb_may_pull(skb, sizeof(*ip6h))) + return -EINVAL; + + ip6h = ipv6_hdr(skb); + + /* + * We're interested in MLD messages only. + * - Version is 6 + * - MLD has always Router Alert hop-by-hop option + * - But we do not support jumbrograms. + */ + if (ip6h->version != 6 || + ip6h->nexthdr != IPPROTO_HOPOPTS || + ip6h->payload_len == 0) + return 0; + + len = ntohs(ip6h->payload_len) + 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); + break; + } + case ICMPV6_MLD2_REPORT: + err = br_ip6_multicast_mld2_report(br, port, skb2); + break; + case ICMPV6_MGM_QUERY: + err = br_ip6_multicast_query(br, port, skb2); + break; + case ICMPV6_MGM_REDUCTION: + { + struct mld_msg *mld; + if (!pskb_may_pull(skb2, sizeof(*mld))) { + err = -EINVAL; + goto out; + } + mld = (struct mld_msg *)skb_transport_header(skb2); + br_ip6_multicast_leave_group(br, port, &mld->mld_mca); + } + } + +out: + kfree_skb(skb2); + return err; +} +#endif + +int br_multicast_rcv(struct net_bridge *br, struct net_bridge_port *port, + struct sk_buff *skb) +{ + BR_INPUT_SKB_CB(skb)->igmp = 0; + BR_INPUT_SKB_CB(skb)->mrouters_only = 0; + + if (br->multicast_disabled) + return 0; + + switch (skb->protocol) { + case htons(ETH_P_IP): + return br_multicast_ipv4_rcv(br, port, skb); +#if IS_ENABLED(CONFIG_IPV6) + case htons(ETH_P_IPV6): + return br_multicast_ipv6_rcv(br, port, skb); +#endif + } + + return 0; +} + +static void br_multicast_query_expired(unsigned long data) +{ + struct net_bridge *br = (void *)data; + + spin_lock(&br->multicast_lock); + if (br->multicast_startup_queries_sent < + br->multicast_startup_query_count) + br->multicast_startup_queries_sent++; + + br_multicast_send_query(br, NULL, br->multicast_startup_queries_sent); + + spin_unlock(&br->multicast_lock); +} + +void br_multicast_init(struct net_bridge *br) +{ + br->hash_elasticity = 4; + br->hash_max = 512; + + br->multicast_router = 1; + br->multicast_last_member_count = 2; + br->multicast_startup_query_count = 2; + + br->multicast_last_member_interval = HZ; + br->multicast_query_response_interval = 10 * HZ; + br->multicast_startup_query_interval = 125 * HZ / 4; + br->multicast_query_interval = 125 * HZ; + br->multicast_querier_interval = 255 * HZ; + br->multicast_membership_interval = 260 * HZ; + + spin_lock_init(&br->multicast_lock); + setup_timer(&br->multicast_router_timer, + br_multicast_local_router_expired, 0); + setup_timer(&br->multicast_querier_timer, + br_multicast_local_router_expired, 0); + setup_timer(&br->multicast_query_timer, br_multicast_query_expired, + (unsigned long)br); +} + +void br_multicast_open(struct net_bridge *br) +{ + br->multicast_startup_queries_sent = 0; + + if (br->multicast_disabled) + return; + + mod_timer(&br->multicast_query_timer, jiffies); +} + +void br_multicast_stop(struct net_bridge *br) +{ + struct net_bridge_mdb_htable *mdb; + struct net_bridge_mdb_entry *mp; + struct hlist_node *p, *n; + u32 ver; + int i; + + del_timer_sync(&br->multicast_router_timer); + del_timer_sync(&br->multicast_querier_timer); + del_timer_sync(&br->multicast_query_timer); + + spin_lock_bh(&br->multicast_lock); + mdb = mlock_dereference(br->mdb, br); + if (!mdb) + goto out; + + br->mdb = NULL; + + ver = mdb->ver; + for (i = 0; i < mdb->max; i++) { + hlist_for_each_entry_safe(mp, p, n, &mdb->mhash[i], + hlist[ver]) { + del_timer(&mp->timer); + call_rcu_bh(&mp->rcu, br_multicast_free_group); + } + } + + if (mdb->old) { + spin_unlock_bh(&br->multicast_lock); + rcu_barrier_bh(); + spin_lock_bh(&br->multicast_lock); + WARN_ON(mdb->old); + } + + mdb->old = mdb; + call_rcu_bh(&mdb->rcu, br_mdb_free); + +out: + spin_unlock_bh(&br->multicast_lock); +} + +int br_multicast_set_router(struct net_bridge *br, unsigned long val) +{ + int err = -ENOENT; + + spin_lock_bh(&br->multicast_lock); + if (!netif_running(br->dev)) + goto unlock; + + switch (val) { + case 0: + case 2: + del_timer(&br->multicast_router_timer); + /* fall through */ + case 1: + br->multicast_router = val; + err = 0; + break; + + default: + err = -EINVAL; + break; + } + +unlock: + spin_unlock_bh(&br->multicast_lock); + + return err; +} + +int br_multicast_set_port_router(struct net_bridge_port *p, unsigned long val) +{ + struct net_bridge *br = p->br; + int err = -ENOENT; + + spin_lock(&br->multicast_lock); + if (!netif_running(br->dev) || p->state == BR_STATE_DISABLED) + goto unlock; + + switch (val) { + case 0: + case 1: + case 2: + p->multicast_router = val; + err = 0; + + if (val < 2 && !hlist_unhashed(&p->rlist)) + hlist_del_init_rcu(&p->rlist); + + if (val == 1) + break; + + del_timer(&p->multicast_router_timer); + + if (val == 0) + break; + + br_multicast_add_router(br, p); + break; + + default: + err = -EINVAL; + break; + } + +unlock: + spin_unlock(&br->multicast_lock); + + return err; +} + +int br_multicast_toggle(struct net_bridge *br, unsigned long val) +{ + struct net_bridge_port *port; + int err = 0; + struct net_bridge_mdb_htable *mdb; + + spin_lock_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_open(br); + list_for_each_entry(port, &br->port_list, list) { + if (port->state == BR_STATE_DISABLED || + port->state == BR_STATE_BLOCKING) + continue; + + __br_multicast_enable_port(port); + } + +unlock: + spin_unlock_bh(&br->multicast_lock); + + return err; +} + +int br_multicast_set_hash_max(struct net_bridge *br, unsigned long val) +{ + int err = -ENOENT; + u32 old; + struct net_bridge_mdb_htable *mdb; + + spin_lock(&br->multicast_lock); + if (!netif_running(br->dev)) + goto unlock; + + err = -EINVAL; + if (!is_power_of_2(val)) + goto unlock; + + mdb = mlock_dereference(br->mdb, br); + if (mdb && val < mdb->size) + goto unlock; + + err = 0; + + old = br->hash_max; + br->hash_max = val; + + if (mdb) { + if (mdb->old) { + err = -EEXIST; +rollback: + br->hash_max = old; + goto unlock; + } + + err = br_mdb_rehash(&br->mdb, br->hash_max, + br->hash_elasticity); + if (err) + goto rollback; + } + +unlock: + spin_unlock(&br->multicast_lock); + + return err; +} |