CGN: Deterministic NAT (VPP-623)

Inside user is statically mapped to a set of outside ports. Support endpoint
dependent mapping to deal with overloading of the outside ports.

Change-Id: I8014438744597a976f8ae459283e8b91f63b7f72
Signed-off-by: Matus Fabian <matfabia@cisco.com>

2 files changed, 100 insertions, 0 deletions

diff --git a/test/test_snat.py b/test/test_snat.py
index f5e6e139..78919a02 100644
--- a/test/test_snat.py
+++ b/test/test_snat.py
@@ -1276,5 +1276,57 @@ class TestSNAT(VppTestCase):
             self.clear_snat()
 
 
+class TestDeterministicNAT(VppTestCase):
+    """ Deterministic NAT Test Cases """
+
+    @classmethod
+    def setUpConstants(cls):
+        super(TestDeterministicNAT, cls).setUpConstants()
+        cls.vpp_cmdline.extend(["snat", "{", "deterministic", "}"])
+
+    @classmethod
+    def setUpClass(cls):
+        super(TestDeterministicNAT, cls).setUpClass()
+
+        try:
+            cls.create_pg_interfaces(range(2))
+            cls.interfaces = list(cls.pg_interfaces)
+
+            for i in cls.interfaces:
+                i.admin_up()
+                i.config_ip4()
+                i.resolve_arp()
+
+        except Exception:
+            super(TestDeterministicNAT, cls).tearDownClass()
+            raise
+
+    def test_deterministic_mode(self):
+        """ S-NAT run deterministic mode """
+        in_addr = '172.16.255.0'
+        out_addr = '172.17.255.50'
+        in_addr_t = '172.16.255.20'
+        in_addr_n = socket.inet_aton(in_addr)
+        out_addr_n = socket.inet_aton(out_addr)
+        in_addr_t_n = socket.inet_aton(in_addr_t)
+        in_plen = 24
+        out_plen = 32
+
+        snat_config = self.vapi.snat_show_config()
+        self.assertEqual(1, snat_config.deterministic)
+
+        self.vapi.snat_add_det_map(in_addr_n, in_plen, out_addr_n, out_plen)
+
+        rep1 = self.vapi.snat_det_forward(in_addr_t_n)
+        self.assertEqual(rep1.out_addr[:4], out_addr_n)
+        rep2 = self.vapi.snat_det_reverse(out_addr_n, rep1.out_port_hi)
+        self.assertEqual(rep2.in_addr[:4], in_addr_t_n)
+
+    def tearDown(self):
+        super(TestDeterministicNAT, self).tearDown()
+        if not self.vpp_dead:
+            self.logger.info(self.vapi.cli("show snat detail"))
+
+
 if __name__ == '__main__':
     unittest.main(testRunner=VppTestRunner)
diff --git a/test/vpp_papi_provider.py b/test/vpp_papi_provider.py
index c7e875f0..b9c4d0c1 100644
--- a/test/vpp_papi_provider.py
+++ b/test/vpp_papi_provider.py
@@ -1123,6 +1123,54 @@ class VppPapiProvider(object):
         """
         return self.api(self.papi.snat_user_dump, {})
 
+    def snat_add_det_map(
+            self,
+            in_addr,
+            in_plen,
+            out_addr,
+            out_plen,
+            is_add=1):
+        """Add/delete S-NAT deterministic mapping
+
+        :param is_add - 1 if add, 0 if delete
+        :param in_addr - inside IP address
+        :param in_plen - inside IP address prefix length
+        :param out_addr - outside IP address
+        :param out_plen - outside IP address prefix length
+        """
+        return self.api(
+            self.papi.snat_add_det_map,
+            {'is_add': is_add,
+             'in_addr': in_addr,
+             'in_plen': in_plen,
+             'out_addr': out_addr,
+             'out_plen': out_plen})
+
+    def snat_det_forward(
+            self,
+            in_addr):
+        """Get outside address and port range from inside address
+
+        :param in_addr - inside IP address
+        """
+        return self.api(
+            self.papi.snat_det_forward,
+            {'in_addr': in_addr})
+
+    def snat_det_reverse(
+            self,
+            out_addr,
+            out_port):
+        """Get inside address from outside address and port
+
+        :param out_addr - outside IP address
+        :param out_port - outside port
+        """
+        return self.api(
+            self.papi.snat_det_reverse,
+            {'out_addr': out_addr,
+             'out_port': out_port})
+
     def control_ping(self):
         self.api(self.papi.control_ping)