rps: Add flag to skb to indicate rxhash is based on L4 tuple

The l4_rxhash flag was added to the skb structure to indicate
that the rxhash value was computed over the 4 tuple for the
packet which includes the port information in the encapsulated
transport packet.  This is used by the stack to preserve the
rxhash value in __skb_rx_tunnel.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 1c12b8e..b3f2611 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1578,7 +1578,7 @@
 #endif
 
 	if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
-		sock_rps_save_rxhash(sk, skb->rxhash);
+		sock_rps_save_rxhash(sk, skb);
 		if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len)) {
 			rsk = sk;
 			goto reset;
@@ -1595,7 +1595,7 @@
 			goto discard;
 
 		if (nsk != sk) {
-			sock_rps_save_rxhash(nsk, skb->rxhash);
+			sock_rps_save_rxhash(nsk, skb);
 			if (tcp_child_process(sk, nsk, skb)) {
 				rsk = nsk;
 				goto reset;
@@ -1603,7 +1603,7 @@
 			return 0;
 		}
 	} else
-		sock_rps_save_rxhash(sk, skb->rxhash);
+		sock_rps_save_rxhash(sk, skb);
 
 	if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len)) {
 		rsk = sk;