net: Add Software fallback infrastructure for socket dependent offloads

With socket dependent offloads we rely on the netdev to transform
the transmitted packets before sending them to the wire.
When a packet from an offloaded socket is rerouted to a different
device we need to detect it and do the transformation in software.

Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com>
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/Kconfig b/net/Kconfig
index 6fa1a44..b62089f 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -407,6 +407,9 @@
 	bool
 	default n
 
+config SOCK_VALIDATE_XMIT
+	bool
+
 config NET_DEVLINK
 	tristate "Network physical/parent device Netlink interface"
 	help