vxlan: allow configuring port range

VXLAN bases source UDP port based on flow to help the
receiver to be able to load balance based on outer header flow.

This patch restricts the port range to the normal UDP local
ports, and allows overriding via configuration.

It also uses jhash of Ethernet header when looking at flows
with out know L3 header.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/if_link.h b/include/linux/if_link.h
index e4dad4d..3265f33 100644
--- a/include/linux/if_link.h
+++ b/include/linux/if_link.h
@@ -284,10 +284,16 @@
 	IFLA_VXLAN_LEARNING,
 	IFLA_VXLAN_AGEING,
 	IFLA_VXLAN_LIMIT,
+	IFLA_VXLAN_PORT_RANGE,
 	__IFLA_VXLAN_MAX
 };
 #define IFLA_VXLAN_MAX	(__IFLA_VXLAN_MAX - 1)
 
+struct ifla_vxlan_port_range {
+	__be16	low;
+	__be16	high;
+};
+
 /* SR-IOV virtual function management section */
 
 enum {