tun: Allow GSO using virtio_net_hdr

Add a IFF_VNET_HDR flag.  This uses the same ABI as virtio_net
(ie. prepending struct virtio_net_hdr to packets) to indicate GSO and
checksum information.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Max Krasnyansky <maxk@qualcomm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h
index 3f0a0995d44..563fae542da 100644
--- a/include/linux/if_tun.h
+++ b/include/linux/if_tun.h
@@ -31,6 +31,7 @@
 #define TUN_NO_PI       0x0040
 #define TUN_ONE_QUEUE   0x0080
 #define TUN_PERSIST     0x0100  
+#define TUN_VNET_HDR    0x0200
 
 /* Ioctl defines */
 #define TUNSETNOCSUM  _IOW('T', 200, int) 
@@ -48,6 +49,7 @@
 #define IFF_TAP         0x0002
 #define IFF_NO_PI       0x1000
 #define IFF_ONE_QUEUE   0x2000
+#define IFF_VNET_HDR    0x4000
 
 /* Features for GSO (TUNSETOFFLOAD). */
 #define TUN_F_CSUM      0x01    /* You can hand me unchecksummed packets. */