Fix IP feature ordering.

Drop comes before lookup when enabled. is_first_or_last is not required when setting a feature, the anchor is added in find_config_with_features().
Don't make the PG interfaces automatically L3 enabled, this way we can have tests that check the L3 protocol disbaled behaviour.

Change-Id: Icef22a920b27ff9cec6ab2da6b05f05c532cb60f
Signed-off-by: Neale Ranns <nranns@cisco.com>

test/test_mpls.py

@@ -738,5 +738,88 @@ class TestMPLS(VppTestCase):
         route_35_eos.remove_vpp_config()
         route_34_eos.remove_vpp_config()
 
+
+class TestMPLSDisabled(VppTestCase):
+    """ MPLS disabled """
+
+    def setUp(self):
+        super(TestMPLSDisabled, self).setUp()
+
+        # create 2 pg interfaces
+        self.create_pg_interfaces(range(2))
+
+        # PG0 is MPLS enalbed
+        self.pg0.admin_up()
+        self.pg0.config_ip4()
+        self.pg0.resolve_arp()
+        self.pg0.enable_mpls()
+
+        # PG 1 is not MPLS enabled
+        self.pg1.admin_up()
+
+    def tearDown(self):
+        super(TestMPLSDisabled, self).tearDown()
+        for i in self.pg_interfaces:
+            i.unconfig_ip4()
+            i.admin_down()
+
+    def send_and_assert_no_replies(self, intf, pkts, remark):
+        intf.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        for i in self.pg_interfaces:
+            i.get_capture(0)
+            i.assert_nothing_captured(remark=remark)
+
+    def test_mpls_disabled(self):
+        """ MPLS Disabled """
+
+        tx = (Ether(src=self.pg1.remote_mac,
+                    dst=self.pg1.local_mac) /
+              MPLS(label=32, ttl=64) /
+              IPv6(src="2001::1", dst=self.pg0.remote_ip6) /
+              UDP(sport=1234, dport=1234) /
+              Raw('\xa5' * 100))
+
+        #
+        # A simple MPLS xconnect - eos label in label out
+        #
+        route_32_eos = VppMplsRoute(self, 32, 1,
+                                    [VppRoutePath(self.pg0.remote_ip4,
+                                                  self.pg0.sw_if_index,
+                                                  labels=[33])])
+        route_32_eos.add_vpp_config()
+
+        #
+        # PG1 does not forward IP traffic
+        #
+        self.send_and_assert_no_replies(self.pg1, tx, "MPLS disabled")
+
+        #
+        # MPLS enable PG1
+        #
+        self.pg1.enable_mpls()
+
+        #
+        # Now we get packets through
+        #
+        self.pg1.add_stream(tx)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+
+        rx = self.pg0.get_capture(1)
+
+        #
+        # Disable PG1
+        #
+        self.pg1.disable_mpls()
+
+        #
+        # PG1 does not forward IP traffic
+        #
+        self.send_and_assert_no_replies(self.pg1, tx, "IPv6 disabled")
+        self.send_and_assert_no_replies(self.pg1, tx, "IPv6 disabled")
+
+
 if __name__ == '__main__':
     unittest.main(testRunner=VppTestRunner)