net: bridge: mcast: don't delete permanent entries when fast leave is enabled

BugLink: https://bugs.launchpad.net/bugs/1840378
[ Upstream commit 5c725b6b65067909548ac9ca9bc777098ec9883d ]

When permanent entries were introduced by the commit below, they were
exempt from timing out and thus igmp leave wouldn't affect them unless
fast leave was enabled on the port which was added before permanent
entries existed. It shouldn't matter if fast leave is enabled or not
if the user added a permanent entry it shouldn't be deleted on igmp
leave.

Before:
$ echo 1 > /sys/class/net/eth4/brport/multicast_fast_leave
$ bridge mdb add dev br0 port eth4 grp 229.1.1.1 permanent
$ bridge mdb show
dev br0 port eth4 grp 229.1.1.1 permanent

< join and leave 229.1.1.1 on eth4 >

$ bridge mdb show
$

After:
$ echo 1 > /sys/class/net/eth4/brport/multicast_fast_leave
$ bridge mdb add dev br0 port eth4 grp 229.1.1.1 permanent
$ bridge mdb show
dev br0 port eth4 grp 229.1.1.1 permanent

< join and leave 229.1.1.1 on eth4 >

$ bridge mdb show
dev br0 port eth4 grp 229.1.1.1 permanent

Fixes: ccb1c31a7a87 ("bridge: add flags to distinguish permanent mdb entires")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 0e2cf76d0d72cec7b168f4d1faa9f8ea29b5fbcf..229e081d31128221004834080ab91492cb859ea1 100644 (file)
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -1623,6 +1623,9 @@ br_multicast_leave_group(struct net_bridge *br,
                        if (!br_port_group_equal(p, port, src))
                                continue;
 
+                       if (p->flags & MDB_PG_FLAGS_PERMANENT)
+                               break;
+
                        rcu_assign_pointer(*pp, p->next);
                        hlist_del_init(&p->mglist);
                        del_timer(&p->timer);