tree 37e01659d8e8974706ecc4042fff98bba274a59a
parent 9ed973cc40c588abeaa58aea0683ea665132d11d
author Linus Lüssing <linus.luessing@web.de> 1394486725 +0100
committer David S. Miller <davem@davemloft.net> 1394594530 -0400

bridge: multicast: enable snooping on general queries only

Without this check someone could easily create a denial of service
by injecting multicast-specific queries to enable the bridge
snooping part if no real querier issuing periodic general queries
is present on the link which would result in the bridge wrongly
shutting down ports for multicast traffic as the bridge did not learn
about these listeners.

With this patch the snooping code is enabled upon receiving valid,
general queries only.

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>