GRE tests and fixes

Change-Id: I234240e9bdd4b69ad64a17b1449ae1e81c0edaca
Signed-off-by: Neale Ranns <nranns@cisco.com>
diff --git a/test/vpp_gre_interface.py b/test/vpp_gre_interface.py
new file mode 100644
index 0000000..b6a6633
--- /dev/null
+++ b/test/vpp_gre_interface.py
@@ -0,0 +1,34 @@
+
+from vpp_interface import VppInterface
+import socket
+
+
+class VppGreInterface(VppInterface):
+    """
+    VPP GRE interface
+    """
+
+    def __init__(self, test, src_ip, dst_ip, outer_fib_id=0, is_teb=0):
+        """ Create VPP loopback interface """
+        self._test = test
+        self.t_src = src_ip
+        self.t_dst = dst_ip
+        self.t_outer_fib = outer_fib_id
+        self.t_is_teb = is_teb
+
+    def add_vpp_config(self):
+        s = socket.inet_pton(socket.AF_INET, self.t_src)
+        d = socket.inet_pton(socket.AF_INET, self.t_dst)
+        r = self.test.vapi.gre_tunnel_add_del(s, d,
+                                              outer_fib_id=self.t_outer_fib,
+                                              is_teb=self.t_is_teb)
+        self._sw_if_index = r.sw_if_index
+        self.post_init_setup()
+
+    def remove_vpp_config(self):
+        s = socket.inet_pton(socket.AF_INET, self.t_src)
+        d = socket.inet_pton(socket.AF_INET, self.t_dst)
+        self.unconfig()
+        r = self.test.vapi.gre_tunnel_add_del(s, d,
+                                              outer_fib_id=self.t_outer_fib,
+                                              is_add=0)