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/actions.c b/net/openvswitch/actions.c
index f7e5891..ceb618c 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c
@@ -564,6 +564,7 @@
 static int output_userspace(struct datapath *dp, struct sk_buff *skb,
 			    struct sw_flow_key *key, const struct nlattr *attr)
 {
+	struct ovs_tunnel_info info;
 	struct dp_upcall_info upcall;
 	const struct nlattr *a;
 	int rem;
@@ -572,6 +573,7 @@
 	upcall.key = key;
 	upcall.userdata = NULL;
 	upcall.portid = 0;
+	upcall.egress_tun_info = NULL;
 
 	for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
 		 a = nla_next(a, &rem)) {
@@ -583,7 +585,24 @@
 		case OVS_USERSPACE_ATTR_PID:
 			upcall.portid = nla_get_u32(a);
 			break;
+
+		case OVS_USERSPACE_ATTR_EGRESS_TUN_PORT: {
+			/* Get out tunnel info. */
+			struct vport *vport;
+
+			vport = ovs_vport_rcu(dp, nla_get_u32(a));
+			if (vport) {
+				int err;
+
+				err = ovs_vport_get_egress_tun_info(vport, skb,
+								    &info);
+				if (!err)
+					upcall.egress_tun_info = &info;
+			}
+			break;
 		}
+
+		} /* End of switch. */
 	}
 
 	return ovs_dp_upcall(dp, skb, &upcall);