WSL2-Linux-Kernel/net/bridge/br_multicast.c

1813 строки
39 KiB
C

/*
* Bridge multicast support.
*
* Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
*/
#include <linux/err.h>
#include <linux/if_ether.h>
#include <linux/igmp.h>
#include <linux/jhash.h>
#include <linux/kernel.h>
#include <linux/log2.h>
#include <linux/netdevice.h>
#include <linux/netfilter_bridge.h>
#include <linux/random.h>
#include <linux/rculist.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/timer.h>
#include <net/ip.h>
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
#include <net/ipv6.h>
#include <net/mld.h>
#include <net/addrconf.h>
#include <net/ip6_checksum.h>
#endif
#include "br_private.h"
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
static inline int ipv6_is_local_multicast(const struct in6_addr *addr)
{
if (ipv6_addr_is_multicast(addr) &&
IPV6_ADDR_MC_SCOPE(addr) <= IPV6_ADDR_SCOPE_LINKLOCAL)
return 1;
return 0;
}
#endif
static inline int br_ip_equal(const struct br_ip *a, const struct br_ip *b)
{
if (a->proto != b->proto)
return 0;
switch (a->proto) {
case htons(ETH_P_IP):
return a->u.ip4 == b->u.ip4;
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
case htons(ETH_P_IPV6):
return ipv6_addr_equal(&a->u.ip6, &b->u.ip6);
#endif
}
return 0;
}
static inline int __br_ip4_hash(struct net_bridge_mdb_htable *mdb, __be32 ip)
{
return jhash_1word(mdb->secret, (__force u32)ip) & (mdb->max - 1);
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
static inline int __br_ip6_hash(struct net_bridge_mdb_htable *mdb,
const struct in6_addr *ip)
{
return jhash2((__force u32 *)ip->s6_addr32, 4, mdb->secret) & (mdb->max - 1);
}
#endif
static inline int br_ip_hash(struct net_bridge_mdb_htable *mdb,
struct br_ip *ip)
{
switch (ip->proto) {
case htons(ETH_P_IP):
return __br_ip4_hash(mdb, ip->u.ip4);
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
case htons(ETH_P_IPV6):
return __br_ip6_hash(mdb, &ip->u.ip6);
#endif
}
return 0;
}
static struct net_bridge_mdb_entry *__br_mdb_ip_get(
struct net_bridge_mdb_htable *mdb, struct br_ip *dst, int hash)
{
struct net_bridge_mdb_entry *mp;
struct hlist_node *p;
hlist_for_each_entry_rcu(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) {
if (br_ip_equal(&mp->addr, dst))
return mp;
}
return NULL;
}
static struct net_bridge_mdb_entry *br_mdb_ip_get(
struct net_bridge_mdb_htable *mdb, struct br_ip *dst)
{
if (!mdb)
return NULL;
return __br_mdb_ip_get(mdb, dst, br_ip_hash(mdb, dst));
}
static struct net_bridge_mdb_entry *br_mdb_ip4_get(
struct net_bridge_mdb_htable *mdb, __be32 dst)
{
struct br_ip br_dst;
br_dst.u.ip4 = dst;
br_dst.proto = htons(ETH_P_IP);
return br_mdb_ip_get(mdb, &br_dst);
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
static struct net_bridge_mdb_entry *br_mdb_ip6_get(
struct net_bridge_mdb_htable *mdb, const struct in6_addr *dst)
{
struct br_ip br_dst;
ipv6_addr_copy(&br_dst.u.ip6, dst);
br_dst.proto = htons(ETH_P_IPV6);
return br_mdb_ip_get(mdb, &br_dst);
}
#endif
struct net_bridge_mdb_entry *br_mdb_get(struct net_bridge *br,
struct sk_buff *skb)
{
struct net_bridge_mdb_htable *mdb = br->mdb;
struct br_ip ip;
if (br->multicast_disabled)
return NULL;
if (BR_INPUT_SKB_CB(skb)->igmp)
return NULL;
ip.proto = skb->protocol;
switch (skb->protocol) {
case htons(ETH_P_IP):
ip.u.ip4 = ip_hdr(skb)->daddr;
break;
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
case htons(ETH_P_IPV6):
ipv6_addr_copy(&ip.u.ip6, &ipv6_hdr(skb)->daddr);
break;
#endif
default:
return NULL;
}
return br_mdb_ip_get(mdb, &ip);
}
static void br_mdb_free(struct rcu_head *head)
{
struct net_bridge_mdb_htable *mdb =
container_of(head, struct net_bridge_mdb_htable, rcu);
struct net_bridge_mdb_htable *old = mdb->old;
mdb->old = NULL;
kfree(old->mhash);
kfree(old);
}
static int br_mdb_copy(struct net_bridge_mdb_htable *new,
struct net_bridge_mdb_htable *old,
int elasticity)
{
struct net_bridge_mdb_entry *mp;
struct hlist_node *p;
int maxlen;
int len;
int i;
for (i = 0; i < old->max; i++)
hlist_for_each_entry(mp, p, &old->mhash[i], hlist[old->ver])
hlist_add_head(&mp->hlist[new->ver],
&new->mhash[br_ip_hash(new, &mp->addr)]);
if (!elasticity)
return 0;
maxlen = 0;
for (i = 0; i < new->max; i++) {
len = 0;
hlist_for_each_entry(mp, p, &new->mhash[i], hlist[new->ver])
len++;
if (len > maxlen)
maxlen = len;
}
return maxlen > elasticity ? -EINVAL : 0;
}
static void br_multicast_free_pg(struct rcu_head *head)
{
struct net_bridge_port_group *p =
container_of(head, struct net_bridge_port_group, rcu);
kfree(p);
}
static void br_multicast_free_group(struct rcu_head *head)
{
struct net_bridge_mdb_entry *mp =
container_of(head, struct net_bridge_mdb_entry, rcu);
kfree(mp);
}
static void br_multicast_group_expired(unsigned long data)
{
struct net_bridge_mdb_entry *mp = (void *)data;
struct net_bridge *br = mp->br;
struct net_bridge_mdb_htable *mdb;
spin_lock(&br->multicast_lock);
if (!netif_running(br->dev) || timer_pending(&mp->timer))
goto out;
if (!hlist_unhashed(&mp->mglist))
hlist_del_init(&mp->mglist);
if (mp->ports)
goto out;
mdb = br->mdb;
hlist_del_rcu(&mp->hlist[mdb->ver]);
mdb->size--;
del_timer(&mp->query_timer);
call_rcu_bh(&mp->rcu, br_multicast_free_group);
out:
spin_unlock(&br->multicast_lock);
}
static void br_multicast_del_pg(struct net_bridge *br,
struct net_bridge_port_group *pg)
{
struct net_bridge_mdb_htable *mdb = br->mdb;
struct net_bridge_mdb_entry *mp;
struct net_bridge_port_group *p;
struct net_bridge_port_group **pp;
mp = br_mdb_ip_get(mdb, &pg->addr);
if (WARN_ON(!mp))
return;
for (pp = &mp->ports; (p = *pp); pp = &p->next) {
if (p != pg)
continue;
rcu_assign_pointer(*pp, p->next);
hlist_del_init(&p->mglist);
del_timer(&p->timer);
del_timer(&p->query_timer);
call_rcu_bh(&p->rcu, br_multicast_free_pg);
if (!mp->ports && hlist_unhashed(&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 **mdbp, int max,
int elasticity)
{
struct net_bridge_mdb_htable *old = *mdbp;
struct net_bridge_mdb_htable *mdb;
int err;
mdb = kmalloc(sizeof(*mdb), GFP_ATOMIC);
if (!mdb)
return -ENOMEM;
mdb->max = max;
mdb->old = old;
mdb->mhash = kzalloc(max * sizeof(*mdb->mhash), GFP_ATOMIC);
if (!mdb->mhash) {
kfree(mdb);
return -ENOMEM;
}
mdb->size = old ? old->size : 0;
mdb->ver = old ? old->ver ^ 1 : 0;
if (!old || elasticity)
get_random_bytes(&mdb->secret, sizeof(mdb->secret));
else
mdb->secret = old->secret;
if (!old)
goto out;
err = br_mdb_copy(mdb, old, elasticity);
if (err) {
kfree(mdb->mhash);
kfree(mdb);
return err;
}
call_rcu_bh(&mdb->rcu, br_mdb_free);
out:
rcu_assign_pointer(*mdbp, mdb);
return 0;
}
static struct sk_buff *br_ip4_multicast_alloc_query(struct net_bridge *br,
__be32 group)
{
struct sk_buff *skb;
struct igmphdr *ih;
struct ethhdr *eth;
struct iphdr *iph;
skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*iph) +
sizeof(*ih) + 4);
if (!skb)
goto out;
skb->protocol = htons(ETH_P_IP);
skb_reset_mac_header(skb);
eth = eth_hdr(skb);
memcpy(eth->h_source, br->dev->dev_addr, 6);
eth->h_dest[0] = 1;
eth->h_dest[1] = 0;
eth->h_dest[2] = 0x5e;
eth->h_dest[3] = 0;
eth->h_dest[4] = 0;
eth->h_dest[5] = 1;
eth->h_proto = htons(ETH_P_IP);
skb_put(skb, sizeof(*eth));
skb_set_network_header(skb, skb->len);
iph = ip_hdr(skb);
iph->version = 4;
iph->ihl = 6;
iph->tos = 0xc0;
iph->tot_len = htons(sizeof(*iph) + sizeof(*ih) + 4);
iph->id = 0;
iph->frag_off = htons(IP_DF);
iph->ttl = 1;
iph->protocol = IPPROTO_IGMP;
iph->saddr = 0;
iph->daddr = htonl(INADDR_ALLHOSTS_GROUP);
((u8 *)&iph[1])[0] = IPOPT_RA;
((u8 *)&iph[1])[1] = 4;
((u8 *)&iph[1])[2] = 0;
((u8 *)&iph[1])[3] = 0;
ip_send_check(iph);
skb_put(skb, 24);
skb_set_transport_header(skb, skb->len);
ih = igmp_hdr(skb);
ih->type = IGMP_HOST_MEMBERSHIP_QUERY;
ih->code = (group ? br->multicast_last_member_interval :
br->multicast_query_response_interval) /
(HZ / IGMP_TIMER_SCALE);
ih->group = group;
ih->csum = 0;
ih->csum = ip_compute_csum((void *)ih, sizeof(struct igmphdr));
skb_put(skb, sizeof(*ih));
__skb_pull(skb, sizeof(*eth));
out:
return skb;
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
struct in6_addr *group)
{
struct sk_buff *skb;
struct ipv6hdr *ip6h;
struct mld_msg *mldq;
struct ethhdr *eth;
u8 *hopopt;
unsigned long interval;
skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*ip6h) +
8 + sizeof(*mldq));
if (!skb)
goto out;
skb->protocol = htons(ETH_P_IPV6);
/* Ethernet header */
skb_reset_mac_header(skb);
eth = eth_hdr(skb);
memcpy(eth->h_source, br->dev->dev_addr, 6);
ipv6_eth_mc_map(group, eth->h_dest);
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 = 8 + sizeof(*mldq);
ip6h->nexthdr = IPPROTO_HOPOPTS;
ip6h->hop_limit = 1;
ipv6_addr_set(&ip6h->saddr, 0, 0, 0, 0);
ipv6_addr_set(&ip6h->daddr, htonl(0xff020000), 0, 0, htonl(1));
hopopt = (u8 *)(ip6h + 1);
hopopt[0] = IPPROTO_ICMPV6; /* next hdr */
hopopt[1] = 0; /* length of HbH */
hopopt[2] = IPV6_TLV_ROUTERALERT; /* Router Alert */
hopopt[3] = 2; /* Length of RA Option */
hopopt[4] = 0; /* Type = 0x0000 (MLD) */
hopopt[5] = 0;
hopopt[6] = IPV6_TLV_PAD0; /* Pad0 */
hopopt[7] = IPV6_TLV_PAD0; /* Pad0 */
skb_put(skb, sizeof(*ip6h) + 8);
/* ICMPv6 */
skb_set_transport_header(skb, skb->len);
mldq = (struct mld_msg *) icmp6_hdr(skb);
interval = ipv6_addr_any(group) ? br->multicast_last_member_interval :
br->multicast_query_response_interval;
mldq->mld_type = ICMPV6_MGM_QUERY;
mldq->mld_code = 0;
mldq->mld_cksum = 0;
mldq->mld_maxdelay = htons((u16)jiffies_to_msecs(interval));
mldq->mld_reserved = 0;
ipv6_addr_copy(&mldq->mld_mca, group);
/* checksum */
mldq->mld_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
sizeof(*mldq), IPPROTO_ICMPV6,
csum_partial(mldq,
sizeof(*mldq), 0));
skb_put(skb, sizeof(*mldq));
__skb_pull(skb, sizeof(*eth));
out:
return skb;
}
#endif
static struct sk_buff *br_multicast_alloc_query(struct net_bridge *br,
struct br_ip *addr)
{
switch (addr->proto) {
case htons(ETH_P_IP):
return br_ip4_multicast_alloc_query(br, addr->u.ip4);
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
case htons(ETH_P_IPV6):
return br_ip6_multicast_alloc_query(br, &addr->u.ip6);
#endif
}
return NULL;
}
static void br_multicast_send_group_query(struct net_bridge_mdb_entry *mp)
{
struct net_bridge *br = mp->br;
struct sk_buff *skb;
skb = br_multicast_alloc_query(br, &mp->addr);
if (!skb)
goto timer;
netif_rx(skb);
timer:
if (++mp->queries_sent < br->multicast_last_member_count)
mod_timer(&mp->query_timer,
jiffies + br->multicast_last_member_interval);
}
static void br_multicast_group_query_expired(unsigned long data)
{
struct net_bridge_mdb_entry *mp = (void *)data;
struct net_bridge *br = mp->br;
spin_lock(&br->multicast_lock);
if (!netif_running(br->dev) || hlist_unhashed(&mp->mglist) ||
mp->queries_sent >= br->multicast_last_member_count)
goto out;
br_multicast_send_group_query(mp);
out:
spin_unlock(&br->multicast_lock);
}
static void br_multicast_send_port_group_query(struct net_bridge_port_group *pg)
{
struct net_bridge_port *port = pg->port;
struct net_bridge *br = port->br;
struct sk_buff *skb;
skb = br_multicast_alloc_query(br, &pg->addr);
if (!skb)
goto timer;
br_deliver(port, skb);
timer:
if (++pg->queries_sent < br->multicast_last_member_count)
mod_timer(&pg->query_timer,
jiffies + br->multicast_last_member_interval);
}
static void br_multicast_port_group_query_expired(unsigned long data)
{
struct net_bridge_port_group *pg = (void *)data;
struct net_bridge_port *port = pg->port;
struct net_bridge *br = port->br;
spin_lock(&br->multicast_lock);
if (!netif_running(br->dev) || hlist_unhashed(&pg->mglist) ||
pg->queries_sent >= br->multicast_last_member_count)
goto out;
br_multicast_send_port_group_query(pg);
out:
spin_unlock(&br->multicast_lock);
}
static struct net_bridge_mdb_entry *br_multicast_get_group(
struct net_bridge *br, struct net_bridge_port *port,
struct br_ip *group, int hash)
{
struct net_bridge_mdb_htable *mdb = br->mdb;
struct net_bridge_mdb_entry *mp;
struct hlist_node *p;
unsigned count = 0;
unsigned max;
int elasticity;
int err;
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 = br->mdb;
struct net_bridge_mdb_entry *mp;
int hash;
if (!mdb) {
if (br_mdb_rehash(&br->mdb, BR_HASH_SIZE, 0))
return NULL;
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 = br->mdb;
hash = br_ip_hash(mdb, group);
break;
default:
goto out;
}
mp = kzalloc(sizeof(*mp), GFP_ATOMIC);
if (unlikely(!mp))
goto out;
mp->br = br;
mp->addr = *group;
setup_timer(&mp->timer, br_multicast_group_expired,
(unsigned long)mp);
setup_timer(&mp->query_timer, br_multicast_group_query_expired,
(unsigned long)mp);
hlist_add_head_rcu(&mp->hlist[mdb->ver], &mdb->mhash[hash]);
mdb->size++;
out:
return mp;
}
static int br_multicast_add_group(struct net_bridge *br,
struct net_bridge_port *port,
struct br_ip *group)
{
struct net_bridge_mdb_entry *mp;
struct net_bridge_port_group *p;
struct net_bridge_port_group **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 (unlikely(IS_ERR(mp) || !mp))
goto err;
if (!port) {
hlist_add_head(&mp->mglist, &br->mglist);
mod_timer(&mp->timer, now + br->multicast_membership_interval);
goto out;
}
for (pp = &mp->ports; (p = *pp); pp = &p->next) {
if (p->port == port)
goto found;
if ((unsigned long)p->port < (unsigned long)port)
break;
}
p = kzalloc(sizeof(*p), GFP_ATOMIC);
err = -ENOMEM;
if (unlikely(!p))
goto err;
p->addr = *group;
p->port = port;
p->next = *pp;
hlist_add_head(&p->mglist, &port->mglist);
setup_timer(&p->timer, br_multicast_port_group_expired,
(unsigned long)p);
setup_timer(&p->query_timer, br_multicast_port_group_query_expired,
(unsigned long)p);
rcu_assign_pointer(*pp, p);
found:
mod_timer(&p->timer, now + br->multicast_membership_interval);
out:
err = 0;
err:
spin_unlock(&br->multicast_lock);
return err;
}
static int br_ip4_multicast_add_group(struct net_bridge *br,
struct net_bridge_port *port,
__be32 group)
{
struct br_ip br_group;
if (ipv4_is_local_multicast(group))
return 0;
br_group.u.ip4 = group;
br_group.proto = htons(ETH_P_IP);
return br_multicast_add_group(br, port, &br_group);
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
static int br_ip6_multicast_add_group(struct net_bridge *br,
struct net_bridge_port *port,
const struct in6_addr *group)
{
struct br_ip br_group;
if (ipv6_is_local_multicast(group))
return 0;
ipv6_addr_copy(&br_group.u.ip6, group);
br_group.proto = htons(ETH_P_IP);
return br_multicast_add_group(br, port, &br_group);
}
#endif
static void br_multicast_router_expired(unsigned long data)
{
struct net_bridge_port *port = (void *)data;
struct net_bridge *br = port->br;
spin_lock(&br->multicast_lock);
if (port->multicast_router != 1 ||
timer_pending(&port->multicast_router_timer) ||
hlist_unhashed(&port->rlist))
goto out;
hlist_del_init_rcu(&port->rlist);
out:
spin_unlock(&br->multicast_lock);
}
static void br_multicast_local_router_expired(unsigned long data)
{
}
static void __br_multicast_send_query(struct net_bridge *br,
struct net_bridge_port *port,
struct br_ip *ip)
{
struct sk_buff *skb;
skb = br_multicast_alloc_query(br, ip);
if (!skb)
return;
if (port) {
__skb_push(skb, sizeof(struct ethhdr));
skb->dev = port->dev;
NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
dev_queue_xmit);
} else
netif_rx(skb);
}
static void br_multicast_send_query(struct net_bridge *br,
struct net_bridge_port *port, u32 sent)
{
unsigned long time;
struct br_ip br_group;
if (!netif_running(br->dev) || br->multicast_disabled ||
timer_pending(&br->multicast_querier_timer))
return;
memset(&br_group.u, 0, sizeof(br_group.u));
br_group.proto = htons(ETH_P_IP);
__br_multicast_send_query(br, port, &br_group);
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
br_group.proto = htons(ETH_P_IPV6);
__br_multicast_send_query(br, port, &br_group);
#endif
time = jiffies;
time += sent < br->multicast_startup_query_count ?
br->multicast_startup_query_interval :
br->multicast_query_interval;
mod_timer(port ? &port->multicast_query_timer :
&br->multicast_query_timer, time);
}
static void br_multicast_port_query_expired(unsigned long data)
{
struct net_bridge_port *port = (void *)data;
struct net_bridge *br = port->br;
spin_lock(&br->multicast_lock);
if (port->state == BR_STATE_DISABLED ||
port->state == BR_STATE_BLOCKING)
goto out;
if (port->multicast_startup_queries_sent <
br->multicast_startup_query_count)
port->multicast_startup_queries_sent++;
br_multicast_send_query(port->br, port,
port->multicast_startup_queries_sent);
out:
spin_unlock(&br->multicast_lock);
}
void br_multicast_add_port(struct net_bridge_port *port)
{
port->multicast_router = 1;
setup_timer(&port->multicast_router_timer, br_multicast_router_expired,
(unsigned long)port);
setup_timer(&port->multicast_query_timer,
br_multicast_port_query_expired, (unsigned long)port);
}
void br_multicast_del_port(struct net_bridge_port *port)
{
del_timer_sync(&port->multicast_router_timer);
}
static void __br_multicast_enable_port(struct net_bridge_port *port)
{
port->multicast_startup_queries_sent = 0;
if (try_to_del_timer_sync(&port->multicast_query_timer) >= 0 ||
del_timer(&port->multicast_query_timer))
mod_timer(&port->multicast_query_timer, jiffies);
}
void br_multicast_enable_port(struct net_bridge_port *port)
{
struct net_bridge *br = port->br;
spin_lock(&br->multicast_lock);
if (br->multicast_disabled || !netif_running(br->dev))
goto out;
__br_multicast_enable_port(port);
out:
spin_unlock(&br->multicast_lock);
}
void br_multicast_disable_port(struct net_bridge_port *port)
{
struct net_bridge *br = port->br;
struct net_bridge_port_group *pg;
struct hlist_node *p, *n;
spin_lock(&br->multicast_lock);
hlist_for_each_entry_safe(pg, p, n, &port->mglist, mglist)
br_multicast_del_pg(br, pg);
if (!hlist_unhashed(&port->rlist))
hlist_del_init_rcu(&port->rlist);
del_timer(&port->multicast_router_timer);
del_timer(&port->multicast_query_timer);
spin_unlock(&br->multicast_lock);
}
static int br_ip4_multicast_igmp3_report(struct net_bridge *br,
struct net_bridge_port *port,
struct sk_buff *skb)
{
struct igmpv3_report *ih;
struct igmpv3_grec *grec;
int i;
int len;
int num;
int type;
int err = 0;
__be32 group;
if (!pskb_may_pull(skb, sizeof(*ih)))
return -EINVAL;
ih = igmpv3_report_hdr(skb);
num = ntohs(ih->ngrec);
len = sizeof(*ih);
for (i = 0; i < num; i++) {
len += sizeof(*grec);
if (!pskb_may_pull(skb, len))
return -EINVAL;
grec = (void *)(skb->data + len - sizeof(*grec));
group = grec->grec_mca;
type = grec->grec_type;
len += ntohs(grec->grec_nsrcs) * 4;
if (!pskb_may_pull(skb, len))
return -EINVAL;
/* We treat this as an IGMPv2 report for now. */
switch (type) {
case IGMPV3_MODE_IS_INCLUDE:
case IGMPV3_MODE_IS_EXCLUDE:
case IGMPV3_CHANGE_TO_INCLUDE:
case IGMPV3_CHANGE_TO_EXCLUDE:
case IGMPV3_ALLOW_NEW_SOURCES:
case IGMPV3_BLOCK_OLD_SOURCES:
break;
default:
continue;
}
err = br_ip4_multicast_add_group(br, port, group);
if (err)
break;
}
return err;
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
static int br_ip6_multicast_mld2_report(struct net_bridge *br,
struct net_bridge_port *port,
struct sk_buff *skb)
{
struct icmp6hdr *icmp6h;
struct mld2_grec *grec;
int i;
int len;
int num;
int err = 0;
if (!pskb_may_pull(skb, sizeof(*icmp6h)))
return -EINVAL;
icmp6h = icmp6_hdr(skb);
num = ntohs(icmp6h->icmp6_dataun.un_data16[1]);
len = sizeof(*icmp6h);
for (i = 0; i < num; i++) {
__be16 *nsrcs, _nsrcs;
nsrcs = skb_header_pointer(skb,
len + offsetof(struct mld2_grec,
grec_mca),
sizeof(_nsrcs), &_nsrcs);
if (!nsrcs)
return -EINVAL;
if (!pskb_may_pull(skb,
len + sizeof(*grec) +
sizeof(struct in6_addr) * (*nsrcs)))
return -EINVAL;
grec = (struct mld2_grec *)(skb->data + len);
len += sizeof(*grec) + sizeof(struct in6_addr) * (*nsrcs);
/* We treat these as MLDv1 reports for now. */
switch (grec->grec_type) {
case MLD2_MODE_IS_INCLUDE:
case MLD2_MODE_IS_EXCLUDE:
case MLD2_CHANGE_TO_INCLUDE:
case MLD2_CHANGE_TO_EXCLUDE:
case MLD2_ALLOW_NEW_SOURCES:
case MLD2_BLOCK_OLD_SOURCES:
break;
default:
continue;
}
err = br_ip6_multicast_add_group(br, port, &grec->grec_mca);
if (!err)
break;
}
return err;
}
#endif
/*
* Add port to rotuer_list
* list is maintained ordered by pointer value
* and locked by br->multicast_lock and RCU
*/
static void br_multicast_add_router(struct net_bridge *br,
struct net_bridge_port *port)
{
struct net_bridge_port *p;
struct hlist_node *n, *slot = NULL;
hlist_for_each_entry(p, n, &br->router_list, rlist) {
if ((unsigned long) port >= (unsigned long) p)
break;
slot = n;
}
if (slot)
hlist_add_after_rcu(slot, &port->rlist);
else
hlist_add_head_rcu(&port->rlist, &br->router_list);
}
static void br_multicast_mark_router(struct net_bridge *br,
struct net_bridge_port *port)
{
unsigned long now = jiffies;
if (!port) {
if (br->multicast_router == 1)
mod_timer(&br->multicast_router_timer,
now + br->multicast_querier_interval);
return;
}
if (port->multicast_router != 1)
return;
if (!hlist_unhashed(&port->rlist))
goto timer;
br_multicast_add_router(br, port);
timer:
mod_timer(&port->multicast_router_timer,
now + br->multicast_querier_interval);
}
static void br_multicast_query_received(struct net_bridge *br,
struct net_bridge_port *port,
int saddr)
{
if (saddr)
mod_timer(&br->multicast_querier_timer,
jiffies + br->multicast_querier_interval);
else if (timer_pending(&br->multicast_querier_timer))
return;
br_multicast_mark_router(br, port);
}
static int br_ip4_multicast_query(struct net_bridge *br,
struct net_bridge_port *port,
struct sk_buff *skb)
{
struct iphdr *iph = ip_hdr(skb);
struct igmphdr *ih = igmp_hdr(skb);
struct net_bridge_mdb_entry *mp;
struct igmpv3_query *ih3;
struct net_bridge_port_group *p;
struct net_bridge_port_group **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(br->mdb, group);
if (!mp)
goto out;
max_delay *= br->multicast_last_member_count;
if (!hlist_unhashed(&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 = *pp); 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(&mp->timer, now + max_delay);
}
out:
spin_unlock(&br->multicast_lock);
return err;
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
static int br_ip6_multicast_query(struct net_bridge *br,
struct net_bridge_port *port,
struct sk_buff *skb)
{
struct ipv6hdr *ip6h = ipv6_hdr(skb);
struct mld_msg *mld = (struct mld_msg *) icmp6_hdr(skb);
struct net_bridge_mdb_entry *mp;
struct mld2_query *mld2q;
struct net_bridge_port_group *p, **pp;
unsigned long max_delay;
unsigned long now = jiffies;
struct in6_addr *group = NULL;
int err = 0;
spin_lock(&br->multicast_lock);
if (!netif_running(br->dev) ||
(port && port->state == BR_STATE_DISABLED))
goto out;
br_multicast_query_received(br, port, !ipv6_addr_any(&ip6h->saddr));
if (skb->len == sizeof(*mld)) {
if (!pskb_may_pull(skb, sizeof(*mld))) {
err = -EINVAL;
goto out;
}
mld = (struct mld_msg *) icmp6_hdr(skb);
max_delay = msecs_to_jiffies(htons(mld->mld_maxdelay));
if (max_delay)
group = &mld->mld_mca;
} else if (skb->len >= sizeof(*mld2q)) {
if (!pskb_may_pull(skb, sizeof(*mld2q))) {
err = -EINVAL;
goto out;
}
mld2q = (struct mld2_query *)icmp6_hdr(skb);
if (!mld2q->mld2q_nsrcs)
group = &mld2q->mld2q_mca;
max_delay = mld2q->mld2q_mrc ? MLDV2_MRC(mld2q->mld2q_mrc) : 1;
}
if (!group)
goto out;
mp = br_mdb_ip6_get(br->mdb, group);
if (!mp)
goto out;
max_delay *= br->multicast_last_member_count;
if (!hlist_unhashed(&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 = *pp); 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(&mp->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 = br->mdb;
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 (!hlist_unhashed(&mp->mglist) &&
(timer_pending(&mp->timer) ?
time_after(mp->timer.expires, time) :
try_to_del_timer_sync(&mp->timer) >= 0)) {
mod_timer(&mp->timer, time);
mp->queries_sent = 0;
mod_timer(&mp->query_timer, now);
}
goto out;
}
for (p = mp->ports; p; p = p->next) {
if (p->port != port)
continue;
if (!hlist_unhashed(&p->mglist) &&
(timer_pending(&p->timer) ?
time_after(p->timer.expires, time) :
try_to_del_timer_sync(&p->timer) >= 0)) {
mod_timer(&p->timer, time);
p->queries_sent = 0;
mod_timer(&p->query_timer, now);
}
break;
}
out:
spin_unlock(&br->multicast_lock);
}
static void br_ip4_multicast_leave_group(struct net_bridge *br,
struct net_bridge_port *port,
__be32 group)
{
struct br_ip br_group;
if (ipv4_is_local_multicast(group))
return;
br_group.u.ip4 = group;
br_group.proto = htons(ETH_P_IP);
br_multicast_leave_group(br, port, &br_group);
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
static void br_ip6_multicast_leave_group(struct net_bridge *br,
struct net_bridge_port *port,
const struct in6_addr *group)
{
struct br_ip br_group;
if (ipv6_is_local_multicast(group))
return;
ipv6_addr_copy(&br_group.u.ip6, group);
br_group.proto = htons(ETH_P_IPV6);
br_multicast_leave_group(br, port, &br_group);
}
#endif
static int br_multicast_ipv4_rcv(struct net_bridge *br,
struct net_bridge_port *port,
struct sk_buff *skb)
{
struct sk_buff *skb2 = skb;
struct iphdr *iph;
struct igmphdr *ih;
unsigned len;
unsigned offset;
int err;
/* We treat OOM as packet loss for now. */
if (!pskb_may_pull(skb, sizeof(*iph)))
return -EINVAL;
iph = ip_hdr(skb);
if (iph->ihl < 5 || iph->version != 4)
return -EINVAL;
if (!pskb_may_pull(skb, ip_hdrlen(skb)))
return -EINVAL;
iph = ip_hdr(skb);
if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
return -EINVAL;
if (iph->protocol != IPPROTO_IGMP)
return 0;
len = ntohs(iph->tot_len);
if (skb->len < len || len < ip_hdrlen(skb))
return -EINVAL;
if (skb->len > len) {
skb2 = skb_clone(skb, GFP_ATOMIC);
if (!skb2)
return -ENOMEM;
err = pskb_trim_rcsum(skb2, len);
if (err)
goto err_out;
}
len -= ip_hdrlen(skb2);
offset = skb_network_offset(skb2) + ip_hdrlen(skb2);
__skb_pull(skb2, offset);
skb_reset_transport_header(skb2);
err = -EINVAL;
if (!pskb_may_pull(skb2, sizeof(*ih)))
goto out;
switch (skb2->ip_summed) {
case CHECKSUM_COMPLETE:
if (!csum_fold(skb2->csum))
break;
/* fall through */
case CHECKSUM_NONE:
skb2->csum = 0;
if (skb_checksum_complete(skb2))
goto out;
}
err = 0;
BR_INPUT_SKB_CB(skb)->igmp = 1;
ih = igmp_hdr(skb2);
switch (ih->type) {
case IGMP_HOST_MEMBERSHIP_REPORT:
case IGMPV2_HOST_MEMBERSHIP_REPORT:
BR_INPUT_SKB_CB(skb2)->mrouters_only = 1;
err = br_ip4_multicast_add_group(br, port, ih->group);
break;
case IGMPV3_HOST_MEMBERSHIP_REPORT:
err = br_ip4_multicast_igmp3_report(br, port, skb2);
break;
case IGMP_HOST_MEMBERSHIP_QUERY:
err = br_ip4_multicast_query(br, port, skb2);
break;
case IGMP_HOST_LEAVE_MESSAGE:
br_ip4_multicast_leave_group(br, port, ih->group);
break;
}
out:
__skb_push(skb2, offset);
err_out:
if (skb2 != skb)
kfree_skb(skb2);
return err;
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
static int br_multicast_ipv6_rcv(struct net_bridge *br,
struct net_bridge_port *port,
struct sk_buff *skb)
{
struct sk_buff *skb2 = skb;
struct ipv6hdr *ip6h;
struct icmp6hdr *icmp6h;
u8 nexthdr;
unsigned len;
unsigned offset;
int err;
if (!pskb_may_pull(skb, sizeof(*ip6h)))
return -EINVAL;
ip6h = ipv6_hdr(skb);
/*
* We're interested in MLD messages only.
* - Version is 6
* - MLD has always Router Alert hop-by-hop option
* - But we do not support jumbrograms.
*/
if (ip6h->version != 6 ||
ip6h->nexthdr != IPPROTO_HOPOPTS ||
ip6h->payload_len == 0)
return 0;
len = ntohs(ip6h->payload_len);
if (skb->len < len)
return -EINVAL;
nexthdr = ip6h->nexthdr;
offset = ipv6_skip_exthdr(skb, sizeof(*ip6h), &nexthdr);
if (offset < 0 || nexthdr != IPPROTO_ICMPV6)
return 0;
/* Okay, we found ICMPv6 header */
skb2 = skb_clone(skb, GFP_ATOMIC);
if (!skb2)
return -ENOMEM;
len -= offset - skb_network_offset(skb2);
__skb_pull(skb2, offset);
skb_reset_transport_header(skb2);
err = -EINVAL;
if (!pskb_may_pull(skb2, sizeof(*icmp6h)))
goto out;
icmp6h = icmp6_hdr(skb2);
switch (icmp6h->icmp6_type) {
case ICMPV6_MGM_QUERY:
case ICMPV6_MGM_REPORT:
case ICMPV6_MGM_REDUCTION:
case ICMPV6_MLD2_REPORT:
break;
default:
err = 0;
goto out;
}
/* Okay, we found MLD message. Check further. */
if (skb2->len > len) {
err = pskb_trim_rcsum(skb2, len);
if (err)
goto out;
}
switch (skb2->ip_summed) {
case CHECKSUM_COMPLETE:
if (!csum_fold(skb2->csum))
break;
/*FALLTHROUGH*/
case CHECKSUM_NONE:
skb2->csum = 0;
if (skb_checksum_complete(skb2))
goto out;
}
err = 0;
BR_INPUT_SKB_CB(skb)->igmp = 1;
switch (icmp6h->icmp6_type) {
case ICMPV6_MGM_REPORT:
{
struct mld_msg *mld = (struct mld_msg *)icmp6h;
BR_INPUT_SKB_CB(skb2)->mrouters_only = 1;
err = br_ip6_multicast_add_group(br, port, &mld->mld_mca);
break;
}
case ICMPV6_MLD2_REPORT:
err = br_ip6_multicast_mld2_report(br, port, skb2);
break;
case ICMPV6_MGM_QUERY:
err = br_ip6_multicast_query(br, port, skb2);
break;
case ICMPV6_MGM_REDUCTION:
{
struct mld_msg *mld = (struct mld_msg *)icmp6h;
br_ip6_multicast_leave_group(br, port, &mld->mld_mca);
}
}
out:
__skb_push(skb2, offset);
if (skb2 != skb)
kfree_skb(skb2);
return err;
}
#endif
int br_multicast_rcv(struct net_bridge *br, struct net_bridge_port *port,
struct sk_buff *skb)
{
BR_INPUT_SKB_CB(skb)->igmp = 0;
BR_INPUT_SKB_CB(skb)->mrouters_only = 0;
if (br->multicast_disabled)
return 0;
switch (skb->protocol) {
case htons(ETH_P_IP):
return br_multicast_ipv4_rcv(br, port, skb);
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
case htons(ETH_P_IPV6):
return br_multicast_ipv6_rcv(br, port, skb);
#endif
}
return 0;
}
static void br_multicast_query_expired(unsigned long data)
{
struct net_bridge *br = (void *)data;
spin_lock(&br->multicast_lock);
if (br->multicast_startup_queries_sent <
br->multicast_startup_query_count)
br->multicast_startup_queries_sent++;
br_multicast_send_query(br, NULL, br->multicast_startup_queries_sent);
spin_unlock(&br->multicast_lock);
}
void br_multicast_init(struct net_bridge *br)
{
br->hash_elasticity = 4;
br->hash_max = 512;
br->multicast_router = 1;
br->multicast_last_member_count = 2;
br->multicast_startup_query_count = 2;
br->multicast_last_member_interval = HZ;
br->multicast_query_response_interval = 10 * HZ;
br->multicast_startup_query_interval = 125 * HZ / 4;
br->multicast_query_interval = 125 * HZ;
br->multicast_querier_interval = 255 * HZ;
br->multicast_membership_interval = 260 * HZ;
spin_lock_init(&br->multicast_lock);
setup_timer(&br->multicast_router_timer,
br_multicast_local_router_expired, 0);
setup_timer(&br->multicast_querier_timer,
br_multicast_local_router_expired, 0);
setup_timer(&br->multicast_query_timer, br_multicast_query_expired,
(unsigned long)br);
}
void br_multicast_open(struct net_bridge *br)
{
br->multicast_startup_queries_sent = 0;
if (br->multicast_disabled)
return;
mod_timer(&br->multicast_query_timer, jiffies);
}
void br_multicast_stop(struct net_bridge *br)
{
struct net_bridge_mdb_htable *mdb;
struct net_bridge_mdb_entry *mp;
struct hlist_node *p, *n;
u32 ver;
int i;
del_timer_sync(&br->multicast_router_timer);
del_timer_sync(&br->multicast_querier_timer);
del_timer_sync(&br->multicast_query_timer);
spin_lock_bh(&br->multicast_lock);
mdb = br->mdb;
if (!mdb)
goto out;
br->mdb = NULL;
ver = mdb->ver;
for (i = 0; i < mdb->max; i++) {
hlist_for_each_entry_safe(mp, p, n, &mdb->mhash[i],
hlist[ver]) {
del_timer(&mp->timer);
del_timer(&mp->query_timer);
call_rcu_bh(&mp->rcu, br_multicast_free_group);
}
}
if (mdb->old) {
spin_unlock_bh(&br->multicast_lock);
rcu_barrier_bh();
spin_lock_bh(&br->multicast_lock);
WARN_ON(mdb->old);
}
mdb->old = mdb;
call_rcu_bh(&mdb->rcu, br_mdb_free);
out:
spin_unlock_bh(&br->multicast_lock);
}
int br_multicast_set_router(struct net_bridge *br, unsigned long val)
{
int err = -ENOENT;
spin_lock_bh(&br->multicast_lock);
if (!netif_running(br->dev))
goto unlock;
switch (val) {
case 0:
case 2:
del_timer(&br->multicast_router_timer);
/* fall through */
case 1:
br->multicast_router = val;
err = 0;
break;
default:
err = -EINVAL;
break;
}
unlock:
spin_unlock_bh(&br->multicast_lock);
return err;
}
int br_multicast_set_port_router(struct net_bridge_port *p, unsigned long val)
{
struct net_bridge *br = p->br;
int err = -ENOENT;
spin_lock(&br->multicast_lock);
if (!netif_running(br->dev) || p->state == BR_STATE_DISABLED)
goto unlock;
switch (val) {
case 0:
case 1:
case 2:
p->multicast_router = val;
err = 0;
if (val < 2 && !hlist_unhashed(&p->rlist))
hlist_del_init_rcu(&p->rlist);
if (val == 1)
break;
del_timer(&p->multicast_router_timer);
if (val == 0)
break;
br_multicast_add_router(br, p);
break;
default:
err = -EINVAL;
break;
}
unlock:
spin_unlock(&br->multicast_lock);
return err;
}
int br_multicast_toggle(struct net_bridge *br, unsigned long val)
{
struct net_bridge_port *port;
int err = -ENOENT;
spin_lock(&br->multicast_lock);
if (!netif_running(br->dev))
goto unlock;
err = 0;
if (br->multicast_disabled == !val)
goto unlock;
br->multicast_disabled = !val;
if (br->multicast_disabled)
goto unlock;
if (br->mdb) {
if (br->mdb->old) {
err = -EEXIST;
rollback:
br->multicast_disabled = !!val;
goto unlock;
}
err = br_mdb_rehash(&br->mdb, br->mdb->max,
br->hash_elasticity);
if (err)
goto rollback;
}
br_multicast_open(br);
list_for_each_entry(port, &br->port_list, list) {
if (port->state == BR_STATE_DISABLED ||
port->state == BR_STATE_BLOCKING)
continue;
__br_multicast_enable_port(port);
}
unlock:
spin_unlock(&br->multicast_lock);
return err;
}
int br_multicast_set_hash_max(struct net_bridge *br, unsigned long val)
{
int err = -ENOENT;
u32 old;
spin_lock(&br->multicast_lock);
if (!netif_running(br->dev))
goto unlock;
err = -EINVAL;
if (!is_power_of_2(val))
goto unlock;
if (br->mdb && val < br->mdb->size)
goto unlock;
err = 0;
old = br->hash_max;
br->hash_max = val;
if (br->mdb) {
if (br->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;
}