vlan: support "loose binding" to the underlying network device

Currently the UP/DOWN state of VLANs is synchronized to the state of the
underlying device, meaning all VLANs are set down once the underlying
device is set down. This causes all routes to the VLAN devices to vanish.

Add a flag to specify a "loose binding" mode, in which only the operstate
is transfered, but the VLAN device state is independant.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index 153f6b9e722c..3d870fda8c4f 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -339,6 +339,7 @@ enum vlan_ioctl_cmds {
 enum vlan_flags {
         VLAN_FLAG_REORDER_HDR   = 0x1,
         VLAN_FLAG_GVRP          = 0x2,
+        VLAN_FLAG_LOOSE_BINDING = 0x4,
 };
 
 enum vlan_name_types {