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/core/dev.c b/net/core/dev.c
index e01c21a..8944e1e 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3112,6 +3112,10 @@ static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device
 	if (unlikely(!skb))
 		goto out_null;
 
+	skb = sk_validate_xmit_skb(skb, dev);
+	if (unlikely(!skb))
+		goto out_null;
+
 	if (netif_needs_gso(skb, features)) {
 		struct sk_buff *segs;