mcast-snooping: Add Multicast Listener Discovery support
Add support for MLDv1 and MLDv2. The behavior is not that different from
IGMP. Packets to all-hosts address and queries are always flooded,
reports go to routers, routers are added when a query is observed, and
all MLD packets go through slow path.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@redhat.com>
Cc: Flavio Leitner <fbl@redhat.com>
Cc: Ben Pfaff <blp@nicira.com>
[blp@nicira.com moved an assignment out of an 'if' statement]
Signed-off-by: Ben Pfaff <blp@nicira.com>