openvswitch: Extend packet attribute for egress tunnel info

OVS vswitch has extended IPFIX exporter to export tunnel headers
to improve network visibility.
To export this information userspace needs to know egress tunnel
for given packet. By extending packet attributes datapath can
export egress tunnel info for given packet. So that userspace
can ask for egress tunnel info in userspace action. This
information is used to build IPFIX data for given flow.

Signed-off-by: Wenyu Zhang <wenyuz@vmware.com>
Acked-by: Romain Lenglet <rlenglet@vmware.com>
Acked-by: Ben Pfaff <blp@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
diff --git a/net/openvswitch/datapath.h b/net/openvswitch/datapath.h
index 1c56a80..2bc577b 100644
--- a/net/openvswitch/datapath.h
+++ b/net/openvswitch/datapath.h
@@ -114,12 +114,14 @@
  * @pid: Netlink PID to which packet should be sent.  If @pid is 0 then no
  * packet is sent and the packet is accounted in the datapath's @n_lost
  * counter.
+ * @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.
  */
 struct dp_upcall_info {
 	u8 cmd;
 	const struct sw_flow_key *key;
 	const struct nlattr *userdata;
 	u32 portid;
+	const struct ovs_tunnel_info *egress_tun_info;
 };
 
 /**