IPv6: Fix not join all-router mcast group when forwarding set.

When forwarding was set and a new net device is register,
we need add this device to the all-router mcast group.

Signed-off-by: Li Wei <lw@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 0 deletions

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index c02280a4d126..6b8ebc5da0e1 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -434,6 +434,10 @@ static struct inet6_dev * ipv6_add_dev(struct net_device *dev)
         /* Join all-node multicast group */
         ipv6_dev_mc_inc(dev, &in6addr_linklocal_allnodes);
 
+        /* Join all-router multicast group if forwarding is set */
+        if (ndev->cnf.forwarding && dev && (dev->flags & IFF_MULTICAST))
+                ipv6_dev_mc_inc(dev, &in6addr_linklocal_allrouters);
+
         return ndev;
 }