packet: Add GSO/csum offload support.
This patch adds GSO/checksum offload to af_packet sockets using
virtio_net_hdr. Based on Rusty's patch to add this support to tun.
It allows GSO/checksum offload to be enabled when using raw socket
backend with virtio_net.
Adds PACKET_VNET_HDR socket option to prepend virtio_net_hdr in the
receive path and process/skip virtio_net_hdr in the send path. This
option is only allowed with SOCK_RAW sockets attached to ethernet
type devices.
v2 updates
----------
Michael's Comments
- Perform length check in packet_snd() when GSO is off even when
vnet_hdr is present.
- Check for SKB_GSO_FCOE type and return -EINVAL
- don't allow tx/rx ring when vnet_hdr is enabled.
Herbert's Comments
- Removed ethernet specific code.
- protocol value is assumed to be passed in by the caller.
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/if_packet.h b/include/linux/if_packet.h
index 4021d47..aa57a5f 100644
--- a/include/linux/if_packet.h
+++ b/include/linux/if_packet.h
@@ -46,6 +46,7 @@
#define PACKET_RESERVE 12
#define PACKET_TX_RING 13
#define PACKET_LOSS 14
+#define PACKET_VNET_HDR 15
struct tpacket_stats {
unsigned int tp_packets;