NAT44: interface output feature and dst NAT (VPP-1200)

Do not translate packet which go out via nat44-in2out-output and was tranlated
in nat44-out2in before. On way back forward packet to nat44-in2out node.

Change-Id: I934d69856f0178c86ff879bc691c9e074b8485c8
Signed-off-by: Matus Fabian <matfabia@cisco.com>

3 files changed, 137 insertions, 7 deletions

diff --git a/src/plugins/nat/in2out.c b/src/plugins/nat/in2out.c
index 1b7a24bdecf..8748013947c 100755
--- a/src/plugins/nat/in2out.c
+++ b/src/plugins/nat/in2out.c
@@ -254,11 +254,14 @@ snat_not_translate (snat_main_t * sm, vlib_node_runtime_t *node,
 
 static inline int
 nat_not_translate_output_feature (snat_main_t * sm, ip4_header_t * ip0,
-                                  u32 proto0, u16 src_port, u32 thread_index)
+                                  u32 proto0, u16 src_port, u16 dst_port,
+                                  u32 thread_index, u32 sw_if_index)
 {
   snat_session_key_t key0;
   clib_bihash_kv_8_8_t kv0, value0;
+  snat_interface_t *i;
 
+  /* src NAT check */
   key0.addr = ip0->src_address;
   key0.port = src_port;
   key0.protocol = proto0;
@@ -266,8 +269,26 @@ nat_not_translate_output_feature (snat_main_t * sm, ip4_header_t * ip0,
   kv0.key = key0.as_u64;
 
   if (!clib_bihash_search_8_8 (&sm->per_thread_data[thread_index].out2in, &kv0,
-                              &value0))
+                               &value0))
+    return 1;
+
+  /* dst NAT check */
+  key0.addr = ip0->dst_address;
+  key0.port = dst_port;
+  key0.protocol = proto0;
+  key0.fib_index = sm->inside_fib_index;
+  kv0.key = key0.as_u64;
+  if (!clib_bihash_search_8_8 (&sm->per_thread_data[thread_index].in2out, &kv0,
+                               &value0))
+  {
+    /* hairpinning */
+    pool_foreach (i, sm->output_feature_interfaces,
+    ({
+      if ((nat_interface_is_inside(i)) && (sw_if_index == i->sw_if_index))
+        return 0;
+    }));
     return 1;
+  }
 
   return 0;
 }
@@ -561,7 +582,7 @@ u32 icmp_match_in2out_slow(snat_main_t *sm, vlib_node_runtime_t *node,
       if (vnet_buffer(b0)->sw_if_index[VLIB_TX] != ~0)
         {
           if (PREDICT_FALSE(nat_not_translate_output_feature(sm,
-              ip0, SNAT_PROTOCOL_ICMP, key0.port, thread_index)))
+              ip0, SNAT_PROTOCOL_ICMP, key0.port, key0.port, thread_index, sw_if_index0)))
             {
               dont_translate = 1;
               goto out;
@@ -1601,7 +1622,7 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
                   if (is_output_feature)
                     {
                       if (PREDICT_FALSE(nat_not_translate_output_feature(sm,
-                          ip0, proto0, udp0->src_port, thread_index)))
+                          ip0, proto0, udp0->src_port, udp0->dst_port, thread_index, sw_if_index0)))
                         goto trace00;
                     }
                   else
@@ -1793,7 +1814,7 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
                   if (is_output_feature)
                     {
                       if (PREDICT_FALSE(nat_not_translate_output_feature(sm,
-                          ip1, proto1, udp1->src_port, thread_index)))
+                          ip1, proto1, udp1->src_port, udp1->dst_port, thread_index, sw_if_index1)))
                         goto trace01;
                     }
                   else
@@ -2021,7 +2042,7 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
                   if (is_output_feature)
                     {
                       if (PREDICT_FALSE(nat_not_translate_output_feature(sm,
-                          ip0, proto0, udp0->src_port, thread_index)))
+                          ip0, proto0, udp0->src_port, udp0->dst_port, thread_index, sw_if_index0)))
                         goto trace0;
                     }
                   else
diff --git a/src/plugins/nat/out2in.c b/src/plugins/nat/out2in.c
index f6d6a0a102d..7f811d97b59 100755
--- a/src/plugins/nat/out2in.c
+++ b/src/plugins/nat/out2in.c
@@ -133,6 +133,7 @@ typedef enum {
   SNAT_OUT2IN_NEXT_LOOKUP,
   SNAT_OUT2IN_NEXT_ICMP_ERROR,
   SNAT_OUT2IN_NEXT_REASS,
+  SNAT_OUT2IN_NEXT_IN2OUT,
   SNAT_OUT2IN_N_NEXT,
 } snat_out2in_next_t;
 
@@ -311,6 +312,26 @@ icmp_get_ed_key(ip4_header_t *ip0, nat_ed_ses_key_t *p_key0)
   return 0;
 }
 
+static int
+next_src_nat (snat_main_t * sm, ip4_header_t * ip, u32 proto, u16 src_port,
+              u32 thread_index)
+{
+  snat_session_key_t key;
+  clib_bihash_kv_8_8_t kv, value;
+
+  key.addr = ip->src_address;
+  key.port = src_port;
+  key.protocol = proto;
+  key.fib_index = sm->inside_fib_index;
+  kv.key = key.as_u64;
+
+  if (!clib_bihash_search_8_8 (&sm->per_thread_data[thread_index].in2out, &kv,
+                               &value))
+    return 1;
+
+  return 0;
+}
+
 static void
 create_bypass_for_fwd(snat_main_t * sm, ip4_header_t * ip)
 {
@@ -419,8 +440,13 @@ u32 icmp_match_out2in_slow(snat_main_t *sm, vlib_node_runtime_t *node,
             }
           else
             {
-              create_bypass_for_fwd(sm, ip0);
               dont_translate = 1;
+              if (next_src_nat(sm, ip0, key0.protocol, key0.port, thread_index))
+                {
+                  next0 = SNAT_OUT2IN_NEXT_IN2OUT;
+                  goto out;
+                }
+              create_bypass_for_fwd(sm, ip0);
               goto out;
             }
         }
@@ -1156,6 +1182,11 @@ snat_out2in_node_fn (vlib_main_t * vm,
                     }
                   else
                     {
+                      if (next_src_nat(sm, ip0, proto0, udp0->src_port, thread_index))
+                        {
+                          next0 = SNAT_OUT2IN_NEXT_IN2OUT;
+                          goto trace0;
+                        }
                       create_bypass_for_fwd(sm, ip0);
                       goto trace0;
                     }
@@ -1327,6 +1358,11 @@ snat_out2in_node_fn (vlib_main_t * vm,
                     }
                   else
                     {
+                      if (next_src_nat(sm, ip1, proto1, udp1->src_port, thread_index))
+                        {
+                          next1 = SNAT_OUT2IN_NEXT_IN2OUT;
+                          goto trace1;
+                        }
                       create_bypass_for_fwd(sm, ip1);
                       goto trace1;
                     }
@@ -1534,6 +1570,11 @@ snat_out2in_node_fn (vlib_main_t * vm,
                     }
                   else
                     {
+                      if (next_src_nat(sm, ip0, proto0, udp0->src_port, thread_index))
+                        {
+                          next0 = SNAT_OUT2IN_NEXT_IN2OUT;
+                          goto trace00;
+                        }
                       create_bypass_for_fwd(sm, ip0);
                       goto trace00;
                     }
@@ -1661,6 +1702,7 @@ VLIB_REGISTER_NODE (snat_out2in_node) = {
     [SNAT_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
     [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
     [SNAT_OUT2IN_NEXT_REASS] = "nat44-out2in-reass",
+    [SNAT_OUT2IN_NEXT_IN2OUT] = "nat44-in2out",
   },
 };
 VLIB_NODE_FUNCTION_MULTIARCH (snat_out2in_node, snat_out2in_node_fn);
@@ -1781,6 +1823,11 @@ nat44_out2in_reass_node_fn (vlib_main_t * vm,
                         }
                       else
                         {
+                          if (next_src_nat(sm, ip0, proto0, udp0->src_port, thread_index))
+                            {
+                              next0 = SNAT_OUT2IN_NEXT_IN2OUT;
+                              goto trace0;
+                            }
                           create_bypass_for_fwd(sm, ip0);
                           goto trace0;
                         }
@@ -1952,6 +1999,7 @@ VLIB_REGISTER_NODE (nat44_out2in_reass_node) = {
     [SNAT_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
     [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
     [SNAT_OUT2IN_NEXT_REASS] = "nat44-out2in-reass",
+    [SNAT_OUT2IN_NEXT_IN2OUT] = "nat44-in2out",
   },
 };
 VLIB_NODE_FUNCTION_MULTIARCH (nat44_out2in_reass_node,
@@ -2441,6 +2489,7 @@ VLIB_REGISTER_NODE (snat_det_out2in_node) = {
     [SNAT_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
     [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
     [SNAT_OUT2IN_NEXT_REASS] = "nat44-out2in-reass",
+    [SNAT_OUT2IN_NEXT_IN2OUT] = "nat44-in2out",
   },
 };
 VLIB_NODE_FUNCTION_MULTIARCH (snat_det_out2in_node, snat_det_out2in_node_fn);
@@ -2934,6 +2983,7 @@ VLIB_REGISTER_NODE (snat_out2in_fast_node) = {
     [SNAT_OUT2IN_NEXT_DROP] = "error-drop",
     [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
     [SNAT_OUT2IN_NEXT_REASS] = "nat44-out2in-reass",
+    [SNAT_OUT2IN_NEXT_IN2OUT] = "nat44-in2out",
   },
 };
 VLIB_NODE_FUNCTION_MULTIARCH (snat_out2in_fast_node, snat_out2in_fast_node_fn);
diff --git a/test/test_nat.py b/test/test_nat.py
index 344a459cbde..695014fe587 100644
--- a/test/test_nat.py
+++ b/test/test_nat.py
@@ -3418,6 +3418,65 @@ class TestNAT44(MethodHolder):
         self.verify_capture_out(capture, nat_ip=self.pg0.remote_ip4,
                                 same_port=True)
 
+    def test_output_feature_and_service3(self):
+        """ NAT44 interface output feature and DST NAT """
+        external_addr = '1.2.3.4'
+        external_port = 80
+        local_port = 8080
+
+        self.vapi.nat44_forwarding_enable_disable(1)
+        self.nat44_add_address(self.nat_addr)
+        self.nat44_add_static_mapping(self.pg1.remote_ip4, external_addr,
+                                      local_port, external_port,
+                                      proto=IP_PROTOS.tcp, out2in_only=1)
+        self.vapi.nat44_interface_add_del_feature(self.pg0.sw_if_index)
+        self.vapi.nat44_interface_add_del_feature(self.pg0.sw_if_index,
+                                                  is_inside=0)
+        self.vapi.nat44_interface_add_del_output_feature(self.pg1.sw_if_index,
+                                                         is_inside=0)
+
+        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
+             IP(src=self.pg0.remote_ip4, dst=external_addr) /
+             TCP(sport=12345, dport=external_port))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, self.pg0.remote_ip4)
+            self.assertEqual(tcp.sport, 12345)
+            self.assertEqual(ip.dst, self.pg1.remote_ip4)
+            self.assertEqual(tcp.dport, local_port)
+            self.check_tcp_checksum(p)
+            self.check_ip_checksum(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            raise
+
+        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
+             IP(src=self.pg1.remote_ip4, dst=self.pg0.remote_ip4) /
+             TCP(sport=local_port, dport=12345))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, external_addr)
+            self.assertEqual(tcp.sport, external_port)
+            self.assertEqual(ip.dst, self.pg0.remote_ip4)
+            self.assertEqual(tcp.dport, 12345)
+            self.check_tcp_checksum(p)
+            self.check_ip_checksum(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            raise
+
     def test_one_armed_nat44(self):
         """ One armed NAT44 """
         remote_host = self.pg9.remote_hosts[0]