vlan: Warn the user if lowerdev has bad vlan features.

Some drivers incorrectly assign vlan acceleration features to
vlan_features thus causing issues for Q-in-Q vlan configurations.
Warn the user of such cases.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index a9591ff2b678..27bfe2f8e2de 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -578,6 +578,9 @@ static int vlan_dev_init(struct net_device *dev)
 
         dev->features |= real_dev->vlan_features | NETIF_F_LLTX;
         dev->gso_max_size = real_dev->gso_max_size;
+        if (dev->features & NETIF_F_VLAN_FEATURES)
+                netdev_warn(real_dev, "VLAN features are set incorrectly.  Q-in-Q configurations may not work correctly.\n");
+
 
         /* ipv6 shared card related stuff */
         dev->dev_id = real_dev->dev_id;