openvswitch: refactor ovs flow extract API.

OVS flow extract is called on packet receive or packet
execute code path.  Following patch defines separate API
for extracting flow-key in packet execute code path.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Andy Zhou <azhou@nicira.com>
diff --git a/net/openvswitch/datapath.h b/net/openvswitch/datapath.h
index b576483..2b982fa 100644
--- a/net/openvswitch/datapath.h
+++ b/net/openvswitch/datapath.h
@@ -97,10 +97,13 @@
  * @flow: The flow associated with this packet.  May be %NULL if no flow.
  * @tun_key: Key for the tunnel that encapsulated this packet. NULL if the
  * packet is not being tunneled.
+ * @input_vport: The original vport packet came in on. This value is cached
+ * when a packet is received by OVS.
  */
 struct ovs_skb_cb {
 	struct sw_flow		*flow;
 	struct ovs_key_ipv4_tunnel  *tun_key;
+	struct vport		*input_vport;
 };
 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
 
@@ -181,7 +184,7 @@
 extern struct notifier_block ovs_dp_device_notifier;
 extern struct genl_family dp_vport_genl_family;
 
-void ovs_dp_process_received_packet(struct vport *, struct sk_buff *);
+void ovs_dp_process_received_packet(struct sk_buff *);
 void ovs_dp_detach_port(struct vport *);
 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
 		  const struct dp_upcall_info *);