rps: Infrastructure in __skb_get_rxhash for deep inspection

Basics for looking for ports in encapsulated packets in tunnels.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/dev.c

@@ -133,6 +133,7 @@
 #include <linux/pci.h>
 #include <linux/inetdevice.h>
 #include <linux/cpu_rmap.h>
+#include <linux/if_tunnel.h>
 
 #include "net-sysfs.h"
 
@@ -2539,6 +2540,7 @@ void __skb_get_rxhash(struct sk_buff *skb)
 	nhoff = skb_network_offset(skb);
 	proto = skb->protocol;
 
+again:
 	switch (proto) {
 	case __constant_htons(ETH_P_IP):
 		if (!pskb_may_pull(skb, sizeof(*ip) + nhoff))
@@ -2567,6 +2569,11 @@ void __skb_get_rxhash(struct sk_buff *skb)
 		goto done;
 	}
 
+	switch (ip_proto) {
+	default:
+		break;
+	}
+
 	ports.v32 = 0;
 	poff = proto_ports_offset(ip_proto);
 	if (poff >= 0) {