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>

1 files changed, 8 insertions, 1 deletions

diff --git a/include/net/dst.h b/include/net/dst.h
index 13d507d69ddb..4fb6c4381791 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -325,7 +325,14 @@ static inline void skb_dst_force(struct sk_buff *skb)
 static inline void __skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev)
 {
         skb->dev = dev;
-        skb->rxhash = 0;
+
+        /*
+         * Clear rxhash so that we can recalulate the hash for the
+         * encapsulated packet, unless we have already determine the hash
+         * over the L4 4-tuple.
+         */
+        if (!skb->l4_rxhash)
+                skb->rxhash = 0;
         skb_set_queue_mapping(skb, 0);
         skb_dst_drop(skb);
         nf_reset(skb);