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authorCong Wang <amwang@redhat.com>2012-12-10 02:15:35 +0000
committerDavid S. Miller <davem@davemloft.net>2012-12-11 13:44:09 -0500
commit2ce297fc24d1f0b70c756d1f593e7a089a2d888d (patch)
treec29d8d8f76ff8c8d574e70a9c28aa06a0a4b4211
parent2925f6c0c7af32720dcbadc586463aeceb6baa22 (diff)
bridge: fix seq check in br_mdb_dump()
In case of rehashing, introduce a global variable 'br_mdb_rehash_seq' which gets increased every time when rehashing, and assign net->dev_base_seq + br_mdb_rehash_seq to cb->seq. In theory cb->seq could be wrapped to zero, but this is not easy to fix, as net->dev_base_seq is not visible inside br_mdb_rehash(). In practice, this is rare. Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Stephen Hemminger <shemminger@vyatta.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Graf <tgraf@suug.ch> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Cong Wang <amwang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/bridge/br_mdb.c6
-rw-r--r--net/bridge/br_multicast.c2
-rw-r--r--net/bridge/br_private.h1
3 files changed, 5 insertions, 4 deletions
diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c
index edc0d731f6b2..ccc43a9bff80 100644
--- a/net/bridge/br_mdb.c
+++ b/net/bridge/br_mdb.c
@@ -117,10 +117,8 @@ static int br_mdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
rcu_read_lock();
- /* TODO: in case of rehashing, we need to check
- * consistency for dumping.
- */
- cb->seq = net->dev_base_seq;
+ /* In theory this could be wrapped to 0... */
+ cb->seq = net->dev_base_seq + br_mdb_rehash_seq;
for_each_netdev_rcu(net, dev) {
if (dev->priv_flags & IFF_EBRIDGE) {
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 68e375ac93bd..847b98a1d5e0 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -37,6 +37,7 @@
rcu_dereference_protected(X, lockdep_is_held(&br->multicast_lock))
static void br_multicast_start_querier(struct net_bridge *br);
+unsigned int br_mdb_rehash_seq;
#if IS_ENABLED(CONFIG_IPV6)
static inline int ipv6_is_transient_multicast(const struct in6_addr *addr)
@@ -338,6 +339,7 @@ static int br_mdb_rehash(struct net_bridge_mdb_htable __rcu **mdbp, int max,
return err;
}
+ br_mdb_rehash_seq++;
call_rcu_bh(&mdb->rcu, br_mdb_free);
out:
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index ae0a6ec0a702..f95b766c7a98 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -411,6 +411,7 @@ extern int br_ioctl_deviceless_stub(struct net *net, unsigned int cmd, void __us
/* br_multicast.c */
#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
+extern unsigned int br_mdb_rehash_seq;
extern int br_multicast_rcv(struct net_bridge *br,
struct net_bridge_port *port,
struct sk_buff *skb);