net: Resend IGMP memberships upon peer notification.

[ Upstream commit 37c343b4f4e70e9dc328ab04903c0ec8d154c1a4 ]

When we notify peers of potential changes,  it's also good to update
IGMP memberships.  For example, during VM migration, updating IGMP
memberships will redirect existing multicast streams to the VM at the
new location.

Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>

diff --git a/net/core/dev.c b/net/core/dev.c
index 33674208d3256ae4d2ee8db5674f5195a15bf50f..4d4213b6f7f668d2622215a9b380f700cdde9c8b 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1268,6 +1268,7 @@ void netdev_notify_peers(struct net_device *dev)
 {
        rtnl_lock();
        call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
+       call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev);
        rtnl_unlock();
 }
 EXPORT_SYMBOL(netdev_notify_peers);