xfrm: Add support for network devices capable of removing the ESP trailer
In conjunction with crypto offload [1], removing the ESP trailer by
hardware can potentially improve the performance by avoiding (1) a
cache miss incurred by reading the nexthdr field and (2) the necessity
to calculate the csum value of the trailer in order to keep skb->csum
valid.
This patch introduces the changes to the xfrm stack and merely serves
as an infrastructure. Subsequent patch to mlx5 driver will put this to
a good use.
[1] https://www.mail-archive.com/netdev@vger.kernel.org/msg175733.html
Signed-off-by: Yossi Kuperman <yossiku@mellanox.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 9c7b70c..f002a2c 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1019,6 +1019,7 @@
#define CRYPTO_FALLBACK 8
#define XFRM_GSO_SEGMENT 16
#define XFRM_GRO 32
+#define XFRM_ESP_NO_TRAILER 64
__u32 status;
#define CRYPTO_SUCCESS 1