SNAT: Add outbound addresses to FIB (VPP-613)

Add the external NAT address to the FIB as receive entries.
This ensures that VPP will reply to ARP for these addresses and we don't need
to enable proxy ARP on the outside interface.

Change-Id: I1db153373c43fec4808845449a17085509ca588c
Signed-off-by: Matus Fabian <matfabia@cisco.com>

1 files changed, 63 insertions, 4 deletions

diff --git a/test/test_snat.py b/test/test_snat.py
index b6cc1c9a17f..a67deede7a5 100644
--- a/test/test_snat.py
+++ b/test/test_snat.py
@@ -6,7 +6,7 @@ import struct
 
 from framework import VppTestCase, VppTestRunner
 from scapy.layers.inet import IP, TCP, UDP, ICMP
-from scapy.layers.l2 import Ether
+from scapy.layers.l2 import Ether, ARP
 from scapy.data import IP_PROTOS
 from util import ppp
 from ipfix import IPFIX, Set, Template, Data, IPFIXDecoder
@@ -524,9 +524,7 @@ class TestSNAT(VppTestCase):
         self.pg3.assert_nothing_captured()
 
     def test_multiple_inside_interfaces(self):
-        """
-        SNAT multiple inside interfaces with non-overlapping address space
-        """
+        """ SNAT multiple inside interfaces (non-overlapping address space) """
 
         self.snat_add_address(self.snat_addr)
         self.vapi.snat_interface_add_del_feature(self.pg0.sw_if_index)
@@ -862,6 +860,67 @@ class TestSNAT(VppTestCase):
                 data = ipfix.decode_data_set(p.getlayer(Set))
                 self.verify_ipfix_addr_exhausted(data)
 
+    def test_pool_addr_fib(self):
+        """ S-NAT add pool addresses to FIB """
+        static_addr = '10.0.0.10'
+        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)
+        self.snat_add_static_mapping(self.pg0.remote_ip4, static_addr)
+
+        # SNAT address
+        p = (Ether(src=self.pg1.remote_mac, dst='ff:ff:ff:ff:ff:ff') /
+             ARP(op=ARP.who_has, pdst=self.snat_addr,
+                 psrc=self.pg1.remote_ip4, hwsrc=self.pg1.remote_mac))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(1)
+        self.assertTrue(capture[0].haslayer(ARP))
+        self.assertTrue(capture[0][ARP].op, ARP.is_at)
+
+        # 1:1 NAT address
+        p = (Ether(src=self.pg1.remote_mac, dst='ff:ff:ff:ff:ff:ff') /
+             ARP(op=ARP.who_has, pdst=static_addr,
+                 psrc=self.pg1.remote_ip4, hwsrc=self.pg1.remote_mac))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(1)
+        self.assertTrue(capture[0].haslayer(ARP))
+        self.assertTrue(capture[0][ARP].op, ARP.is_at)
+
+        # send ARP to non-SNAT interface
+        p = (Ether(src=self.pg2.remote_mac, dst='ff:ff:ff:ff:ff:ff') /
+             ARP(op=ARP.who_has, pdst=self.snat_addr,
+                 psrc=self.pg2.remote_ip4, hwsrc=self.pg2.remote_mac))
+        self.pg2.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(0)
+
+        # remove addresses and verify
+        self.snat_add_address(self.snat_addr, is_add=0)
+        self.snat_add_static_mapping(self.pg0.remote_ip4, static_addr,
+                                     is_add=0)
+
+        p = (Ether(src=self.pg1.remote_mac, dst='ff:ff:ff:ff:ff:ff') /
+             ARP(op=ARP.who_has, pdst=self.snat_addr,
+                 psrc=self.pg1.remote_ip4, hwsrc=self.pg1.remote_mac))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(0)
+
+        p = (Ether(src=self.pg1.remote_mac, dst='ff:ff:ff:ff:ff:ff') /
+             ARP(op=ARP.who_has, pdst=static_addr,
+                 psrc=self.pg1.remote_ip4, hwsrc=self.pg1.remote_mac))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(0)
+
     def tearDown(self):
         super(TestSNAT, self).tearDown()
         if not self.vpp_dead: