nat: session cleanup fix

Ticket: VPP-1795
Type: fix

Change-Id: Ib3b5742119d7013c293a11eb3dd1aadf46b422dd
Signed-off-by: Filip Varga <fivarga@cisco.com>

1 files changed, 95 insertions, 55 deletions

diff --git a/src/plugins/nat/test/test_nat.py b/src/plugins/nat/test/test_nat.py
index 29fd5ca23c5..0daa61042c1 100644
--- a/src/plugins/nat/test/test_nat.py
+++ b/src/plugins/nat/test/test_nat.py
@@ -2606,61 +2606,6 @@ class TestNAT44(MethodHolder):
                 self.logger.error(ppp("Unexpected or invalid packet:", packet))
                 raise
 
-    def test_max_translations_per_user(self):
-        """ MAX translations per user - recycle the least recently used """
-
-        self.nat44_add_address(self.nat_addr)
-        flags = self.config_flags.NAT_IS_INSIDE
-        self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg0.sw_if_index,
-            flags=flags, is_add=1)
-        self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg1.sw_if_index,
-            is_add=1)
-
-        # get maximum number of translations per user
-        nat44_config = self.vapi.nat_show_config()
-
-        # send more than maximum number of translations per user packets
-        pkts_num = nat44_config.max_translations_per_user + 5
-        pkts = []
-        for port in range(0, pkts_num):
-            p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
-                 IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-                 TCP(sport=1025 + port))
-            pkts.append(p)
-        self.pg0.add_stream(pkts)
-        self.pg_enable_capture(self.pg_interfaces)
-        self.pg_start()
-
-        # verify number of translated packet
-        self.pg1.get_capture(pkts_num)
-
-        users = self.vapi.nat44_user_dump()
-        for user in users:
-            if user.ip_address == self.pg0.remote_ip4:
-                self.assertEqual(user.nsessions,
-                                 nat44_config.max_translations_per_user)
-                self.assertEqual(user.nstaticsessions, 0)
-
-        tcp_port = 22
-        self.nat44_add_static_mapping(self.pg0.remote_ip4, self.nat_addr,
-                                      tcp_port, tcp_port,
-                                      proto=IP_PROTOS.tcp)
-        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=tcp_port))
-        self.pg0.add_stream(p)
-        self.pg_enable_capture(self.pg_interfaces)
-        self.pg_start()
-        self.pg1.get_capture(1)
-        users = self.vapi.nat44_user_dump()
-        for user in users:
-            if user.ip_address == self.pg0.remote_ip4:
-                self.assertEqual(user.nsessions,
-                                 nat44_config.max_translations_per_user - 1)
-                self.assertEqual(user.nstaticsessions, 1)
-
     def test_interface_addr(self):
         """ Acquire NAT44 addresses from interface """
         self.vapi.nat44_add_del_interface_addr(
@@ -4386,6 +4331,101 @@ class TestNAT44(MethodHolder):
         self.logger.info(self.vapi.cli("show nat ha"))
 
 
+class TestNAT44EndpointDependent2(MethodHolder):
+    """ Endpoint-Dependent session test cases """
+
+    icmp_timeout = 2
+
+    @classmethod
+    def setUpConstants(cls):
+        super(TestNAT44EndpointDependent2, cls).setUpConstants()
+        cls.vpp_cmdline.extend(["nat", "{", "endpoint-dependent",
+                                "translation", "hash", "buckets", "1",
+                                "icmp", "timeout", str(cls.icmp_timeout), "}"])
+
+    @classmethod
+    def setUpClass(cls):
+        super(TestNAT44EndpointDependent2, cls).setUpClass()
+        try:
+            translation_buckets = 1
+            cls.max_translations = 10 * translation_buckets
+
+            cls.create_pg_interfaces(range(2))
+            cls.interfaces = list(cls.pg_interfaces[0:2])
+
+            for i in cls.interfaces:
+                i.admin_up()
+                i.config_ip4()
+                i.resolve_arp()
+
+            cls.pg0.generate_remote_hosts(1)
+            cls.pg0.configure_ipv4_neighbors()
+
+            cls.pg1.generate_remote_hosts(1)
+            cls.pg1.configure_ipv4_neighbors()
+
+        except Exception:
+            super(TestNAT44EndpointDependent2, cls).tearDownClass()
+            raise
+
+    def create_icmp_stream(self, in_if, out_if, count):
+        """
+        Create ICMP packet stream for inside network
+
+        :param in_if: Inside interface
+        :param out_if: Outside interface
+        :param count: Number of packets
+        """
+
+        self.assertTrue(count > 0)
+        icmp_id = random.randint(0, 65535 - (count - 1))
+
+        pkts = list()
+        for i in range(count):
+            p = (Ether(dst=in_if.local_mac, src=in_if.remote_mac) /
+                 IP(src=in_if.remote_ip4, dst=out_if.remote_ip4, ttl=64) /
+                 ICMP(id=icmp_id + i, type='echo-request'))
+            pkts.append(p)
+        return pkts
+
+    def send_pkts(self, pkts, expected=None):
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        return self.pg1.get_capture(
+                len(pkts) if expected is None else expected)
+
+    def test_session_cleanup(self):
+        """ NAT44 session cleanup test """
+
+        self.nat44_add_address(self.pg1.local_ip4)
+        flags = self.config_flags.NAT_IS_INSIDE
+        self.vapi.nat44_interface_add_del_feature(
+            sw_if_index=self.pg0.sw_if_index,
+            flags=flags, is_add=1)
+        self.vapi.nat44_interface_add_del_feature(
+            sw_if_index=self.pg1.sw_if_index,
+            is_add=1)
+
+        nat_config = self.vapi.nat_show_config()
+        self.assertEqual(1, nat_config.endpoint_dependent)
+
+        pkts = self.create_icmp_stream(self.pg0, self.pg1,
+                                       self.max_translations + 2)
+        sz = len(pkts)
+
+        # positive test
+        self.send_pkts(pkts[0:self.max_translations])
+
+        # false positive test
+        self.send_pkts(pkts[self.max_translations:sz - 1], 0)
+
+        sleep(self.icmp_timeout)
+
+        # positive test
+        self.send_pkts(pkts[self.max_translations + 1:sz])
+
+
 class TestNAT44EndpointDependent(MethodHolder):
     """ Endpoint-Dependent mapping and filtering test cases """