NAT44: fix ICMP error translation for endpoint dependent sessions (VPP-1150)

[vpp.git] / src / plugins / nat / in2out.c

diff --git a/src/plugins/nat/in2out.c b/src/plugins/nat/in2out.c
index b0dbbc8..a453328 100755 (executable)
--- a/src/plugins/nat/in2out.c
+++ b/src/plugins/nat/in2out.c
@@ -162,7 +162,7 @@ typedef enum {
 /**
  * @brief Check if packet should be translated
  *
- * Packets aimed at outside interface and external addresss with active session
+ * Packets aimed at outside interface and external address with active session
  * should be translated.
  *
  * @param sm            NAT main
@@ -273,6 +273,7 @@ static u32 slow_path (snat_main_t *sm, vlib_buffer_t *b0,
   if (PREDICT_FALSE (maximum_sessions_exceeded(sm, thread_index)))
     {
       b0->error = node->errors[SNAT_IN2OUT_ERROR_MAX_SESSIONS_EXCEEDED];
+      nat_ipfix_logging_max_sessions(sm->max_translations);
       return SNAT_IN2OUT_NEXT_DROP;
     }
 
@@ -294,13 +295,6 @@ static u32 slow_path (snat_main_t *sm, vlib_buffer_t *b0,
       return SNAT_IN2OUT_NEXT_DROP;
     }
 
-  s = nat_session_alloc_or_recycle (sm, u, thread_index);
-  if (!s)
-    {
-      clib_warning ("create NAT session failed");
-      return SNAT_IN2OUT_NEXT_DROP;
-    }
-
   /* First try to match static mapping by local address and port */
   if (snat_static_mapping_match (sm, *key0, &key1, 0, 0, 0))
     {
@@ -319,9 +313,17 @@ static u32 slow_path (snat_main_t *sm, vlib_buffer_t *b0,
   else
     {
       u->nstaticsessions++;
-      s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
     }
 
+  s = nat_session_alloc_or_recycle (sm, u, thread_index);
+  if (!s)
+    {
+      clib_warning ("create NAT session failed");
+      return SNAT_IN2OUT_NEXT_DROP;
+    }
+
+  if (address_index == ~0)
+    s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
   s->outside_address_index = address_index;
   s->in2out = *key0;
   s->out2in = key1;
@@ -400,6 +402,53 @@ snat_in2out_error_t icmp_get_key(ip4_header_t *ip0,
   return -1; /* success */
 }
 
+static_always_inline int
+icmp_get_ed_key(ip4_header_t *ip0, nat_ed_ses_key_t *p_key0)
+{
+  icmp46_header_t *icmp0;
+  nat_ed_ses_key_t key0;
+  icmp_echo_header_t *echo0, *inner_echo0 = 0;
+  ip4_header_t *inner_ip0 = 0;
+  void *l4_header = 0;
+  icmp46_header_t *inner_icmp0;
+
+  icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
+  echo0 = (icmp_echo_header_t *)(icmp0+1);
+
+  if (!icmp_is_error_message (icmp0))
+    {
+      key0.proto = IP_PROTOCOL_ICMP;
+      key0.l_addr = ip0->src_address;
+      key0.r_addr = ip0->dst_address;
+      key0.l_port = key0.r_port = echo0->identifier;
+    }
+  else
+    {
+      inner_ip0 = (ip4_header_t *)(echo0+1);
+      l4_header = ip4_next_header (inner_ip0);
+      key0.proto = inner_ip0->protocol;
+      key0.r_addr = inner_ip0->src_address;
+      key0.l_addr = inner_ip0->dst_address;
+      switch (ip_proto_to_snat_proto (inner_ip0->protocol))
+        {
+        case SNAT_PROTOCOL_ICMP:
+          inner_icmp0 = (icmp46_header_t*)l4_header;
+          inner_echo0 = (icmp_echo_header_t *)(inner_icmp0+1);
+          key0.r_port = key0.l_port = inner_echo0->identifier;
+          break;
+        case SNAT_PROTOCOL_UDP:
+        case SNAT_PROTOCOL_TCP:
+          key0.l_port = ((tcp_udp_header_t*)l4_header)->dst_port;
+          key0.r_port = ((tcp_udp_header_t*)l4_header)->src_port;
+          break;
+        default:
+          return SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL;
+        }
+    }
+  *p_key0 = key0;
+  return 0;
+}
+
 /**
  * Get address and port values to be used for ICMP packet translation
  * and create session if needed
@@ -480,8 +529,34 @@ u32 icmp_match_in2out_slow(snat_main_t *sm, vlib_node_runtime_t *node,
           goto out;
         }
 
-      s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
-                              value0.value);
+      if (PREDICT_FALSE (value0.value == ~0ULL))
+        {
+          nat_ed_ses_key_t key;
+          clib_bihash_kv_16_8_t s_kv, s_value;
+
+          key.as_u64[0] = 0;
+          key.as_u64[1] = 0;
+          if (icmp_get_ed_key (ip0, &key))
+            {
+              b0->error = node->errors[SNAT_IN2OUT_ERROR_UNSUPPORTED_PROTOCOL];
+              next0 = SNAT_IN2OUT_NEXT_DROP;
+              goto out;
+            }
+          key.fib_index = rx_fib_index0;
+          s_kv.key[0] = key.as_u64[0];
+          s_kv.key[1] = key.as_u64[1];
+          if (!clib_bihash_search_16_8 (&sm->in2out_ed, &s_kv, &s_value))
+            s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
+                                    s_value.value);
+          else
+           {
+              next0 = SNAT_IN2OUT_NEXT_DROP;
+              goto out;
+           }
+        }
+      else
+        s0 = pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
+                                value0.value);
     }
 
 out:
@@ -1002,6 +1077,7 @@ snat_in2out_unknown_proto (snat_main_t *sm,
       if (PREDICT_FALSE (maximum_sessions_exceeded(sm, thread_index)))
         {
           b->error = node->errors[SNAT_IN2OUT_ERROR_MAX_SESSIONS_EXCEEDED];
+          nat_ipfix_logging_max_sessions(sm->max_translations);
           return 0;
         }
 
@@ -1189,6 +1265,7 @@ snat_in2out_lb (snat_main_t *sm,
       if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
         {
           b->error = node->errors[SNAT_IN2OUT_ERROR_MAX_SESSIONS_EXCEEDED];
+          nat_ipfix_logging_max_sessions(sm->max_translations);
           return 0;
         }
 
@@ -1463,7 +1540,7 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
                     {
                       s0 = snat_in2out_lb(sm, b0, ip0, rx_fib_index0,
                                           thread_index, now, vm, node);
-                      if (!s0)
+                      if (!s0 && !sm->forwarding_enabled)
                         next0 = SNAT_IN2OUT_NEXT_DROP;
                       goto trace00;
                     }
@@ -1642,7 +1719,7 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
                     {
                       s1 = snat_in2out_lb(sm, b1, ip1, rx_fib_index1,
                                           thread_index, now, vm, node);
-                      if (!s1)
+                      if (!s1 && !sm->forwarding_enabled)
                         next1 = SNAT_IN2OUT_NEXT_DROP;
                       goto trace01;
                     }
@@ -1854,7 +1931,7 @@ snat_in2out_node_fn_inline (vlib_main_t * vm,
                     {
                       s0 = snat_in2out_lb(sm, b0, ip0, rx_fib_index0,
                                           thread_index, now, vm, node);
-                      if (!s0)
+                      if (!s0 && !sm->forwarding_enabled)
                         next0 = SNAT_IN2OUT_NEXT_DROP;
                       goto trace0;
                     }