NAT44: interface output feature and service host direct access (VPP-1176)

forwarding mode:
session initiaded from service host - translate
session initiaded from remote host - do not translate

Change-Id: I48170ee8e4ad14d3d3083ee31a40ef8d10d6ff32
Signed-off-by: Matus Fabian <matfabia@cisco.com>
diff --git a/test/test_nat.py b/test/test_nat.py
index 7ff3f85..ec2009e 100644
--- a/test/test_nat.py
+++ b/test/test_nat.py
@@ -3369,6 +3369,50 @@
             self.logger.error(ppp("Unexpected or invalid packet:", p))
             raise
 
+    def test_output_feature_and_service2(self):
+        """ NAT44 interface output feature and service host direct access """
+        self.vapi.nat44_forwarding_enable_disable(1)
+        self.nat44_add_address(self.nat_addr)
+        self.vapi.nat44_interface_add_del_output_feature(self.pg1.sw_if_index,
+                                                         is_inside=0)
+
+        # session initiaded from service host - translate
+        pkts = self.create_stream_in(self.pg0, self.pg1)
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(len(pkts))
+        self.verify_capture_out(capture)
+
+        pkts = self.create_stream_out(self.pg1)
+        self.pg1.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(len(pkts))
+        self.verify_capture_in(capture, self.pg0)
+
+        tcp_port_out = self.tcp_port_out
+        udp_port_out = self.udp_port_out
+        icmp_id_out = self.icmp_id_out
+
+        # session initiaded from remote host - do not translate
+        pkts = self.create_stream_out(self.pg1,
+                                      self.pg0.remote_ip4,
+                                      use_inside_ports=True)
+        self.pg1.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(len(pkts))
+        self.verify_capture_in(capture, self.pg0)
+
+        pkts = self.create_stream_in(self.pg0, self.pg1)
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(len(pkts))
+        self.verify_capture_out(capture, nat_ip=self.pg0.remote_ip4,
+                                same_port=True)
+
     def test_one_armed_nat44(self):
         """ One armed NAT44 """
         remote_host = self.pg9.remote_hosts[0]