SNAT: fix ICMP hairpinning

Change-Id: I9d63133bd1db72917571ade868040c4597c896a1
Signed-off-by: Matus Fabian <matfabia@cisco.com>

1 files changed, 164 insertions, 2 deletions

diff --git a/test/test_snat.py b/test/test_snat.py
index 8d384384..0eceaab2 100644
--- a/test/test_snat.py
+++ b/test/test_snat.py
@@ -324,7 +324,7 @@ class TestSNAT(MethodHolder):
                 i.config_ip4()
                 i.resolve_arp()
 
-            cls.pg0.generate_remote_hosts(2)
+            cls.pg0.generate_remote_hosts(3)
             cls.pg0.configure_ipv4_neighbors()
 
             cls.overlapping_interfaces = list(list(cls.pg_interfaces[4:7]))
@@ -1016,7 +1016,7 @@ class TestSNAT(MethodHolder):
                              self.icmp_id_in])
 
     def test_hairpinning(self):
-        """ SNAT hairpinning """
+        """ SNAT hairpinning - 1:1 NAT with port"""
 
         host = self.pg0.remote_hosts[0]
         server = self.pg0.remote_hosts[1]
@@ -1075,6 +1075,168 @@ class TestSNAT(MethodHolder):
             self.logger.error(ppp("Unexpected or invalid packet:"), p)
             raise
 
+    def test_hairpinning2(self):
+        """ SNAT hairpinning - 1:1 NAT"""
+
+        server1_nat_ip = "10.0.0.10"
+        server2_nat_ip = "10.0.0.11"
+        host = self.pg0.remote_hosts[0]
+        server1 = self.pg0.remote_hosts[1]
+        server2 = self.pg0.remote_hosts[2]
+        server_tcp_port = 22
+        server_udp_port = 20
+
+        self.snat_add_address(self.snat_addr)
+        self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
+        self.vapi.snat_interface_add_del_feature(self.pg1.sw_if_index,
+                                                 is_inside=0)
+
+        # add static mapping for servers
+        self.snat_add_static_mapping(server1.ip4, server1_nat_ip)
+        self.snat_add_static_mapping(server2.ip4, server2_nat_ip)
+
+        # host to server1
+        pkts = []
+        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
+             IP(src=host.ip4, dst=server1_nat_ip) /
+             TCP(sport=self.tcp_port_in, dport=server_tcp_port))
+        pkts.append(p)
+        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
+             IP(src=host.ip4, dst=server1_nat_ip) /
+             UDP(sport=self.udp_port_in, dport=server_udp_port))
+        pkts.append(p)
+        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
+             IP(src=host.ip4, dst=server1_nat_ip) /
+             ICMP(id=self.icmp_id_in, type='echo-request'))
+        pkts.append(p)
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(len(pkts))
+        for packet in capture:
+            try:
+                self.assertEqual(packet[IP].src, self.snat_addr)
+                self.assertEqual(packet[IP].dst, server1.ip4)
+                if packet.haslayer(TCP):
+                    self.assertNotEqual(packet[TCP].sport, self.tcp_port_in)
+                    self.assertEqual(packet[TCP].dport, server_tcp_port)
+                    self.tcp_port_out = packet[TCP].sport
+                elif packet.haslayer(UDP):
+                    self.assertNotEqual(packet[UDP].sport, self.udp_port_in)
+                    self.assertEqual(packet[UDP].dport, server_udp_port)
+                    self.udp_port_out = packet[UDP].sport
+                else:
+                    self.assertNotEqual(packet[ICMP].id, self.icmp_id_in)
+                    self.icmp_id_out = packet[ICMP].id
+            except:
+                self.logger.error(ppp("Unexpected or invalid packet:", packet))
+                raise
+
+        # server1 to host
+        pkts = []
+        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
+             IP(src=server1.ip4, dst=self.snat_addr) /
+             TCP(sport=server_tcp_port, dport=self.tcp_port_out))
+        pkts.append(p)
+        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
+             IP(src=server1.ip4, dst=self.snat_addr) /
+             UDP(sport=server_udp_port, dport=self.udp_port_out))
+        pkts.append(p)
+        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
+             IP(src=server1.ip4, dst=self.snat_addr) /
+             ICMP(id=self.icmp_id_out, type='echo-reply'))
+        pkts.append(p)
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(len(pkts))
+        for packet in capture:
+            try:
+                self.assertEqual(packet[IP].src, server1_nat_ip)
+                self.assertEqual(packet[IP].dst, host.ip4)
+                if packet.haslayer(TCP):
+                    self.assertEqual(packet[TCP].dport, self.tcp_port_in)
+                    self.assertEqual(packet[TCP].sport, server_tcp_port)
+                elif packet.haslayer(UDP):
+                    self.assertEqual(packet[UDP].dport, self.udp_port_in)
+                    self.assertEqual(packet[UDP].sport, server_udp_port)
+                else:
+                    self.assertEqual(packet[ICMP].id, self.icmp_id_in)
+            except:
+                self.logger.error(ppp("Unexpected or invalid packet:", packet))
+                raise
+
+        # server2 to server1
+        pkts = []
+        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
+             IP(src=server2.ip4, dst=server1_nat_ip) /
+             TCP(sport=self.tcp_port_in, dport=server_tcp_port))
+        pkts.append(p)
+        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
+             IP(src=server2.ip4, dst=server1_nat_ip) /
+             UDP(sport=self.udp_port_in, dport=server_udp_port))
+        pkts.append(p)
+        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
+             IP(src=server2.ip4, dst=server1_nat_ip) /
+             ICMP(id=self.icmp_id_in, type='echo-request'))
+        pkts.append(p)
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(len(pkts))
+        for packet in capture:
+            try:
+                self.assertEqual(packet[IP].src, server2_nat_ip)
+                self.assertEqual(packet[IP].dst, server1.ip4)
+                if packet.haslayer(TCP):
+                    self.assertEqual(packet[TCP].sport, self.tcp_port_in)
+                    self.assertEqual(packet[TCP].dport, server_tcp_port)
+                    self.tcp_port_out = packet[TCP].sport
+                elif packet.haslayer(UDP):
+                    self.assertEqual(packet[UDP].sport, self.udp_port_in)
+                    self.assertEqual(packet[UDP].dport, server_udp_port)
+                    self.udp_port_out = packet[UDP].sport
+                else:
+                    self.assertEqual(packet[ICMP].id, self.icmp_id_in)
+                    self.icmp_id_out = packet[ICMP].id
+            except:
+                self.logger.error(ppp("Unexpected or invalid packet:", packet))
+                raise
+
+        # server1 to server2
+        pkts = []
+        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
+             IP(src=server1.ip4, dst=server2_nat_ip) /
+             TCP(sport=server_tcp_port, dport=self.tcp_port_out))
+        pkts.append(p)
+        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
+             IP(src=server1.ip4, dst=server2_nat_ip) /
+             UDP(sport=server_udp_port, dport=self.udp_port_out))
+        pkts.append(p)
+        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
+             IP(src=server1.ip4, dst=server2_nat_ip) /
+             ICMP(id=self.icmp_id_out, type='echo-reply'))
+        pkts.append(p)
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(len(pkts))
+        for packet in capture:
+            try:
+                self.assertEqual(packet[IP].src, server1_nat_ip)
+                self.assertEqual(packet[IP].dst, server2.ip4)
+                if packet.haslayer(TCP):
+                    self.assertEqual(packet[TCP].dport, self.tcp_port_in)
+                    self.assertEqual(packet[TCP].sport, server_tcp_port)
+                elif packet.haslayer(UDP):
+                    self.assertEqual(packet[UDP].dport, self.udp_port_in)
+                    self.assertEqual(packet[UDP].sport, server_udp_port)
+                else:
+                    self.assertEqual(packet[ICMP].id, self.icmp_id_in)
+            except:
+                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 """