NAT44: fix virtual fragmentation reassembly in forwarding mode (VPP-1501)

Change-Id: Id86d8aa8753b9b2ff4c709b11e3901ba8d552918
Signed-off-by: Matus Fabian <matfabia@cisco.com>

diff --git a/src/plugins/nat/out2in.c b/src/plugins/nat/out2in.c
index 9cace08..52f2023 100755 (executable)
--- a/src/plugins/nat/out2in.c
+++ b/src/plugins/nat/out2in.c
@@ -1443,6 +1443,12 @@ nat44_out2in_reass_node_fn (vlib_main_t * vm,
                            node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
                          next0 = SNAT_OUT2IN_NEXT_DROP;
                        }
+                     else
+                       {
+                         reass0->flags |= NAT_REASS_FLAG_ED_DONT_TRANSLATE;
+                         nat_ip4_reass_get_frags (reass0,
+                                                  &fragments_to_loopback);
+                       }
                      goto trace0;
                    }
 
@@ -1474,6 +1480,8 @@ nat44_out2in_reass_node_fn (vlib_main_t * vm,
            }
          else
            {
+             if (reass0->flags & NAT_REASS_FLAG_ED_DONT_TRANSLATE)
+               goto trace0;
              if (PREDICT_FALSE (reass0->sess_index == (u32) ~ 0))
                {
                  if (nat_ip4_reass_add_fragment

diff --git a/test/test_nat.py b/test/test_nat.py
index 22e8903..bc47623 100644 (file)
--- a/test/test_nat.py
+++ b/test/test_nat.py
@@ -3339,6 +3339,32 @@ class TestNAT44(MethodHolder):
         self.frag_in_order(proto=IP_PROTOS.udp)
         self.frag_in_order(proto=IP_PROTOS.icmp)
 
+    def test_frag_forwarding(self):
+        """ NAT44 forwarding fragment test """
+        self.vapi.nat44_add_interface_addr(self.pg1.sw_if_index)
+        self.vapi.nat44_interface_add_del_feature(self.pg0.sw_if_index)
+        self.vapi.nat44_interface_add_del_feature(self.pg1.sw_if_index,
+                                                  is_inside=0)
+        self.vapi.nat44_forwarding_enable_disable(1)
+
+        data = "A" * 16 + "B" * 16 + "C" * 3
+        pkts = self.create_stream_frag(self.pg1,
+                                       self.pg0.remote_ip4,
+                                       4789,
+                                       4789,
+                                       data,
+                                       proto=IP_PROTOS.udp)
+        self.pg1.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        frags = self.pg0.get_capture(len(pkts))
+        p = self.reass_frags_and_verify(frags,
+                                        self.pg1.remote_ip4,
+                                        self.pg0.remote_ip4)
+        self.assertEqual(p[UDP].sport, 4789)
+        self.assertEqual(p[UDP].dport, 4789)
+        self.assertEqual(data, p[Raw].load)
+
     def test_reass_hairpinning(self):
         """ NAT44 fragments hairpinning """