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

[ Upstream commit d6ddef9e641d1229d4ec841dc75ae703171c3e92 ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 0f335c67eb8..be29337ea39 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -433,6 +433,10 @@ 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;
 }