nat: respect arc features (multi worker)
[vpp.git] / src / plugins / nat / in2out_ed.c
index 31977ac..733e4f0 100644 (file)
 #include <nat/nat_ipfix_logging.h>
 #include <nat/nat_reass.h>
 #include <nat/nat_inlines.h>
-
-#define foreach_nat_in2out_ed_error                       \
-_(UNSUPPORTED_PROTOCOL, "Unsupported protocol")         \
-_(IN2OUT_PACKETS, "Good in2out packets processed")      \
-_(OUT_OF_PORTS, "Out of ports")                         \
-_(BAD_ICMP_TYPE, "unsupported ICMP type")               \
-_(MAX_SESSIONS_EXCEEDED, "Maximum sessions exceeded")   \
-_(DROP_FRAGMENT, "Drop fragment")                       \
-_(MAX_REASS, "Maximum reassemblies exceeded")           \
-_(MAX_FRAG, "Maximum fragments per reassembly exceeded")
-
-typedef enum
-{
-#define _(sym,str) NAT_IN2OUT_ED_ERROR_##sym,
-  foreach_nat_in2out_ed_error
-#undef _
-    NAT_IN2OUT_ED_N_ERROR,
-} nat_in2out_ed_error_t;
+#include <nat/nat_syslog.h>
+#include <nat/nat_ha.h>
 
 static char *nat_in2out_ed_error_strings[] = {
 #define _(sym,string) string,
@@ -53,16 +37,6 @@ static char *nat_in2out_ed_error_strings[] = {
 #undef _
 };
 
-typedef enum
-{
-  NAT_IN2OUT_ED_NEXT_LOOKUP,
-  NAT_IN2OUT_ED_NEXT_DROP,
-  NAT_IN2OUT_ED_NEXT_ICMP_ERROR,
-  NAT_IN2OUT_ED_NEXT_SLOW_PATH,
-  NAT_IN2OUT_ED_NEXT_REASS,
-  NAT_IN2OUT_ED_N_NEXT,
-} nat_in2out_ed_next_t;
-
 typedef struct
 {
   u32 sw_if_index;
@@ -71,12 +45,6 @@ typedef struct
   u32 is_slow_path;
 } nat_in2out_ed_trace_t;
 
-vlib_node_registration_t nat44_ed_in2out_node;
-vlib_node_registration_t nat44_ed_in2out_slowpath_node;
-vlib_node_registration_t nat44_ed_in2out_output_node;
-vlib_node_registration_t nat44_ed_in2out_output_slowpath_node;
-vlib_node_registration_t nat44_ed_in2out_reass_node;
-
 static u8 *
 format_nat_in2out_ed_trace (u8 * s, va_list * args)
 {
@@ -95,55 +63,7 @@ format_nat_in2out_ed_trace (u8 * s, va_list * args)
   return s;
 }
 
-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 = echo0->identifier;
-      key0.r_port = 0;
-    }
-  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 = 0;
-         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 NAT_IN2OUT_ED_ERROR_UNSUPPORTED_PROTOCOL;
-       }
-    }
-  *p_key0 = key0;
-  return 0;
-}
-
+#ifndef CLIB_MARCH_VARIANT
 int
 nat44_i2o_ed_is_idle_session_cb (clib_bihash_kv_16_8_t * kv, void *arg)
 {
@@ -184,18 +104,30 @@ nat44_i2o_ed_is_idle_session_cb (clib_bihash_kv_16_8_t * kv, void *arg)
       ed_kv.key[0] = ed_key.as_u64[0];
       ed_kv.key[1] = ed_key.as_u64[1];
       if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &ed_kv, 0))
-       nat_log_warn ("out2in_ed key del failed");
+       nat_elog_warn ("out2in_ed key del failed");
 
       if (snat_is_unk_proto_session (s))
        goto delete;
 
-      snat_ipfix_logging_nat44_ses_delete (s->in2out.addr.as_u32,
+      snat_ipfix_logging_nat44_ses_delete (ctx->thread_index,
+                                          s->in2out.addr.as_u32,
                                           s->out2in.addr.as_u32,
                                           s->in2out.protocol,
                                           s->in2out.port,
                                           s->out2in.port,
                                           s->in2out.fib_index);
 
+      nat_syslog_nat44_sdel (s->user_index, s->in2out.fib_index,
+                            &s->in2out.addr, s->in2out.port,
+                            &s->ext_host_nat_addr, s->ext_host_nat_port,
+                            &s->out2in.addr, s->out2in.port,
+                            &s->ext_host_addr, s->ext_host_port,
+                            s->in2out.protocol, is_twice_nat_session (s));
+
+      nat_ha_sdel (&s->out2in.addr, s->out2in.port, &s->ext_host_addr,
+                  s->ext_host_port, s->out2in.protocol, s->out2in.fib_index,
+                  ctx->thread_index);
+
       if (is_twice_nat_session (s))
        {
          for (i = 0; i < vec_len (sm->twice_nat_addresses); i++)
@@ -225,6 +157,7 @@ nat44_i2o_ed_is_idle_session_cb (clib_bihash_kv_16_8_t * kv, void *arg)
 
   return 0;
 }
+#endif
 
 static inline u32
 icmp_in2out_ed_slow_path (snat_main_t * sm, vlib_buffer_t * b0,
@@ -236,12 +169,14 @@ icmp_in2out_ed_slow_path (snat_main_t * sm, vlib_buffer_t * b0,
   next0 = icmp_in2out (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
                       next0, thread_index, p_s0, 0);
   snat_session_t *s0 = *p_s0;
-  if (PREDICT_TRUE (next0 != NAT_IN2OUT_ED_NEXT_DROP && s0))
+  if (PREDICT_TRUE (next0 != NAT_NEXT_DROP && s0))
     {
       /* Accounting */
       nat44_session_update_counters (s0, now,
                                     vlib_buffer_length_in_chain
-                                    (sm->vlib_main, b0));
+                                    (sm->vlib_main, b0), thread_index);
+      /* Per-user LRU list maintenance */
+      nat44_session_update_lru (sm, s0, thread_index);
     }
   return next0;
 }
@@ -252,9 +187,10 @@ slow_path_ed (snat_main_t * sm,
              u32 rx_fib_index,
              clib_bihash_kv_16_8_t * kv,
              snat_session_t ** sessionp,
-             vlib_node_runtime_t * node, u32 next, u32 thread_index, f64 now)
+             vlib_node_runtime_t * node, u32 next, u32 thread_index, f64 now,
+             tcp_header_t * tcp)
 {
-  snat_session_t *s;
+  snat_session_t *s = 0;
   snat_user_t *u;
   snat_session_key_t key0, key1;
   lb_nat_type_t lb = 0, is_sm = 0;
@@ -263,6 +199,7 @@ slow_path_ed (snat_main_t * sm,
   u32 proto = ip_proto_to_snat_proto (key->proto);
   nat_outside_fib_t *outside_fib;
   fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
+  u8 identity_nat;
   fib_prefix_t pfx = {
     .fp_proto = FIB_PROTOCOL_IP4,
     .fp_len = 32,
@@ -275,9 +212,9 @@ slow_path_ed (snat_main_t * sm,
   if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
     {
       b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_SESSIONS_EXCEEDED];
-      nat_ipfix_logging_max_sessions (sm->max_translations);
-      nat_log_notice ("maximum sessions exceeded");
-      return NAT_IN2OUT_ED_NEXT_DROP;
+      nat_ipfix_logging_max_sessions (thread_index, sm->max_translations);
+      nat_elog_notice ("maximum sessions exceeded");
+      return NAT_NEXT_DROP;
     }
 
   key0.addr = key->l_addr;
@@ -286,7 +223,8 @@ slow_path_ed (snat_main_t * sm,
   key0.fib_index = rx_fib_index;
   key1.fib_index = sm->outside_fib_index;
   /* First try to match static mapping by local address and port */
-  if (snat_static_mapping_match (sm, key0, &key1, 0, 0, 0, &lb, 0))
+  if (snat_static_mapping_match
+      (sm, key0, &key1, 0, 0, 0, &lb, 0, &identity_nat))
     {
       /* Try to create dynamic translation */
       if (snat_alloc_outside_address_and_port (sm->addresses, rx_fib_index,
@@ -294,33 +232,50 @@ slow_path_ed (snat_main_t * sm,
                                               sm->port_per_thread,
                                               tsm->snat_thread_index))
        {
-         nat_log_notice ("addresses exhausted");
+         nat_elog_notice ("addresses exhausted");
          b->error = node->errors[NAT_IN2OUT_ED_ERROR_OUT_OF_PORTS];
-         return NAT_IN2OUT_ED_NEXT_DROP;
+         return NAT_NEXT_DROP;
        }
     }
   else
-    is_sm = 1;
+    {
+      if (PREDICT_FALSE (identity_nat))
+       {
+         *sessionp = s;
+         return next;
+       }
+
+      is_sm = 1;
+    }
+
+  if (proto == SNAT_PROTOCOL_TCP)
+    {
+      if (!tcp_is_init (tcp))
+       {
+         b->error = node->errors[NAT_IN2OUT_ED_ERROR_NON_SYN];
+         return NAT_NEXT_DROP;
+       }
+    }
 
   u = nat_user_get_or_create (sm, &key->l_addr, rx_fib_index, thread_index);
   if (!u)
     {
-      nat_log_warn ("create NAT user failed");
+      nat_elog_warn ("create NAT user failed");
       if (!is_sm)
        snat_free_outside_address_and_port (sm->addresses,
                                            thread_index, &key1);
-      return NAT_IN2OUT_ED_NEXT_DROP;
+      return NAT_NEXT_DROP;
     }
 
   s = nat_ed_session_alloc (sm, u, thread_index, now);
   if (!s)
     {
       nat44_delete_user_with_no_session (sm, u, thread_index);
-      nat_log_warn ("create NAT session failed");
+      nat_elog_warn ("create NAT session failed");
       if (!is_sm)
        snat_free_outside_address_and_port (sm->addresses,
                                            thread_index, &key1);
-      return NAT_IN2OUT_ED_NEXT_DROP;
+      return NAT_NEXT_DROP;
     }
 
   user_session_increment (sm, u, is_sm);
@@ -368,7 +323,7 @@ slow_path_ed (snat_main_t * sm,
   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->in2out_ed, kv,
                                               nat44_i2o_ed_is_idle_session_cb,
                                               &ctx))
-    nat_log_notice ("in2out-ed key add failed");
+    nat_elog_notice ("in2out-ed key add failed");
 
   make_ed_kv (kv, &key1.addr, &key->r_addr, key->proto, s->out2in.fib_index,
              key1.port, key->r_port);
@@ -376,16 +331,31 @@ slow_path_ed (snat_main_t * sm,
   if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->out2in_ed, kv,
                                               nat44_o2i_ed_is_idle_session_cb,
                                               &ctx))
-    nat_log_notice ("out2in-ed key add failed");
+    nat_elog_notice ("out2in-ed key add failed");
 
   *sessionp = s;
 
   /* log NAT event */
-  snat_ipfix_logging_nat44_ses_create (s->in2out.addr.as_u32,
+  snat_ipfix_logging_nat44_ses_create (thread_index,
+                                      s->in2out.addr.as_u32,
                                       s->out2in.addr.as_u32,
                                       s->in2out.protocol,
                                       s->in2out.port,
                                       s->out2in.port, s->in2out.fib_index);
+
+  nat_syslog_nat44_sadd (s->user_index, s->in2out.fib_index,
+                        &s->in2out.addr, s->in2out.port,
+                        &s->ext_host_nat_addr, s->ext_host_nat_port,
+                        &s->out2in.addr, s->out2in.port,
+                        &s->ext_host_addr, s->ext_host_port,
+                        s->in2out.protocol, 0);
+
+  nat_ha_sadd (&s->in2out.addr, s->in2out.port, &s->out2in.addr,
+              s->out2in.port, &s->ext_host_addr, s->ext_host_port,
+              &s->ext_host_nat_addr, s->ext_host_nat_port,
+              s->in2out.protocol, s->in2out.fib_index, s->flags,
+              thread_index, 0);
+
   return next;
 }
 
@@ -411,7 +381,7 @@ nat44_ed_not_translate (snat_main_t * sm, vlib_node_runtime_t * node,
       key0.protocol = proto;
       key0.fib_index = sm->outside_fib_index;
       /* or is static mappings */
-      if (!snat_static_mapping_match (sm, key0, &key1, 1, 0, 0, 0, 0))
+      if (!snat_static_mapping_match (sm, key0, &key1, 1, 0, 0, 0, 0, 0))
        return 0;
     }
   else
@@ -441,7 +411,7 @@ nat_not_translate_output_feature_fwd (snat_main_t * sm, ip4_header_t * ip,
   if (ip->protocol == IP_PROTOCOL_ICMP)
     {
       key.as_u64[0] = key.as_u64[1] = 0;
-      if (icmp_get_ed_key (ip, &key))
+      if (get_icmp_i2o_ed_key (ip, &key))
        return 0;
       key.fib_index = 0;
       kv.key[0] = key.as_u64[0];
@@ -472,7 +442,10 @@ nat_not_translate_output_feature_fwd (snat_main_t * sm, ip4_header_t * ip,
            }
          /* Accounting */
          nat44_session_update_counters (s, now,
-                                        vlib_buffer_length_in_chain (vm, b));
+                                        vlib_buffer_length_in_chain (vm, b),
+                                        thread_index);
+         /* Per-user LRU list maintenance */
+         nat44_session_update_lru (sm, s, thread_index);
          return 1;
        }
       else
@@ -499,7 +472,17 @@ nat44_ed_not_translate_output_feature (snat_main_t * sm, ip4_header_t * ip,
   make_ed_kv (&kv, &ip->src_address, &ip->dst_address, proto, tx_fib_index,
              src_port, dst_port);
   if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &kv, &value))
-    return 1;
+    {
+      s = pool_elt_at_index (tsm->sessions, value.value);
+      if (nat44_is_ses_closed (s))
+       {
+         nat_free_session_data (sm, s, thread_index, 0);
+         nat44_delete_session (sm, s, thread_index);
+       }
+      else
+       s->flags |= SNAT_SESSION_FLAG_OUTPUT_FEATURE;
+      return 1;
+    }
 
   /* dst NAT check */
   make_ed_kv (&kv, &ip->dst_address, &ip->src_address, proto, rx_fib_index,
@@ -524,6 +507,7 @@ nat44_ed_not_translate_output_feature (snat_main_t * sm, ip4_header_t * ip,
   return 0;
 }
 
+#ifndef CLIB_MARCH_VARIANT
 u32
 icmp_match_in2out_ed (snat_main_t * sm, vlib_node_runtime_t * node,
                      u32 thread_index, vlib_buffer_t * b, ip4_header_t * ip,
@@ -546,11 +530,11 @@ icmp_match_in2out_ed (snat_main_t * sm, vlib_node_runtime_t * node,
   rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
 
   key.as_u64[0] = key.as_u64[1] = 0;
-  err = icmp_get_ed_key (ip, &key);
+  err = get_icmp_i2o_ed_key (ip, &key);
   if (err != 0)
     {
       b->error = node->errors[err];
-      next = NAT_IN2OUT_ED_NEXT_DROP;
+      next = NAT_NEXT_DROP;
       goto out;
     }
   key.fib_index = rx_fib_index;
@@ -594,15 +578,21 @@ icmp_match_in2out_ed (snat_main_t * sm, vlib_node_runtime_t * node,
       if (PREDICT_FALSE (icmp_is_error_message (icmp)))
        {
          b->error = node->errors[NAT_IN2OUT_ED_ERROR_BAD_ICMP_TYPE];
-         next = NAT_IN2OUT_ED_NEXT_DROP;
+         next = NAT_NEXT_DROP;
          goto out;
        }
 
       next = slow_path_ed (sm, b, rx_fib_index, &kv, &s, node, next,
-                          thread_index, vlib_time_now (sm->vlib_main));
+                          thread_index, vlib_time_now (sm->vlib_main), 0);
 
-      if (PREDICT_FALSE (next == NAT_IN2OUT_ED_NEXT_DROP))
+      if (PREDICT_FALSE (next == NAT_NEXT_DROP))
        goto out;
+
+      if (!s)
+       {
+         dont_translate = 1;
+         goto out;
+       }
     }
   else
     {
@@ -611,7 +601,7 @@ icmp_match_in2out_ed (snat_main_t * sm, vlib_node_runtime_t * node,
                         !icmp_is_error_message (icmp)))
        {
          b->error = node->errors[NAT_IN2OUT_ED_ERROR_BAD_ICMP_TYPE];
-         next = NAT_IN2OUT_ED_NEXT_DROP;
+         next = NAT_NEXT_DROP;
          goto out;
        }
 
@@ -627,6 +617,7 @@ out:
     *(snat_session_t **) d = s;
   return next;
 }
+#endif
 
 static snat_session_t *
 nat44_ed_in2out_unknown_proto (snat_main_t * sm,
@@ -700,8 +691,8 @@ nat44_ed_in2out_unknown_proto (snat_main_t * sm,
       if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
        {
          b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_SESSIONS_EXCEEDED];
-         nat_ipfix_logging_max_sessions (sm->max_translations);
-         nat_log_notice ("maximum sessions exceeded");
+         nat_ipfix_logging_max_sessions (thread_index, sm->max_translations);
+         nat_elog_notice ("maximum sessions exceeded");
          return 0;
        }
 
@@ -709,7 +700,7 @@ nat44_ed_in2out_unknown_proto (snat_main_t * sm,
                                  thread_index);
       if (!u)
        {
-         nat_log_warn ("create NAT user failed");
+         nat_elog_warn ("create NAT user failed");
          return 0;
        }
 
@@ -778,7 +769,7 @@ nat44_ed_in2out_unknown_proto (snat_main_t * sm,
       if (!s)
        {
          nat44_delete_user_with_no_session (sm, u, thread_index);
-         nat_log_warn ("create NAT session failed");
+         nat_elog_warn ("create NAT session failed");
          return 0;
        }
 
@@ -799,13 +790,13 @@ nat44_ed_in2out_unknown_proto (snat_main_t * sm,
                  rx_fib_index, 0, 0);
       s_kv.value = s - tsm->sessions;
       if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &s_kv, 1))
-       nat_log_notice ("in2out key add failed");
+       nat_elog_notice ("in2out key add failed");
 
       make_ed_kv (&s_kv, &s->out2in.addr, &ip->dst_address, ip->protocol,
                  outside_fib_index, 0, 0);
       s_kv.value = s - tsm->sessions;
       if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &s_kv, 1))
-       nat_log_notice ("out2in key add failed");
+       nat_elog_notice ("out2in key add failed");
     }
 
   /* Update IP checksum */
@@ -814,7 +805,10 @@ nat44_ed_in2out_unknown_proto (snat_main_t * sm,
   ip->checksum = ip_csum_fold (sum);
 
   /* Accounting */
-  nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b));
+  nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
+                                thread_index);
+  /* Per-user LRU list maintenance */
+  nat44_session_update_lru (sm, s, thread_index);
 
   /* Hairpinning */
   if (vnet_buffer (b)->sw_if_index[VLIB_TX] == ~0)
@@ -833,14 +827,22 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
                                int is_output_feature)
 {
   u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
-  nat_in2out_ed_next_t next_index;
+  nat_next_t next_index;
   snat_main_t *sm = &snat_main;
   f64 now = vlib_time_now (vm);
   u32 thread_index = vm->thread_index;
   snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
+  u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
+    0, fragments = 0, def_slow, def_reass;
+
+  def_slow = is_output_feature ? NAT_NEXT_IN2OUT_ED_OUTPUT_SLOW_PATH :
+    NAT_NEXT_IN2OUT_ED_SLOW_PATH;
+
+  def_reass = is_output_feature ? NAT_NEXT_IN2OUT_ED_OUTPUT_REASS :
+    NAT_NEXT_IN2OUT_ED_REASS;
 
-  stats_node_index = is_slow_path ? nat44_ed_in2out_slowpath_node.index :
-    nat44_ed_in2out_node.index;
+  stats_node_index = is_slow_path ? sm->ed_in2out_slowpath_node_index :
+    sm->ed_in2out_node_index;
 
   from = vlib_frame_vector_args (frame);
   n_left_from = frame->n_vectors;
@@ -894,10 +896,22 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
          b0 = vlib_get_buffer (vm, bi0);
          b1 = vlib_get_buffer (vm, bi1);
 
-         next0 = NAT_IN2OUT_ED_NEXT_LOOKUP;
-
          if (is_output_feature)
-           iph_offset0 = vnet_buffer (b0)->ip.save_rewrite_length;
+           {
+             // output feature fast path is enabled on the arc
+             // we need new arc_next feature
+             if (PREDICT_TRUE (!is_slow_path))
+               {
+                 vnet_feature_next (&nat_buffer_opaque (b0)->arc_next, b0);
+                 vnet_feature_next (&nat_buffer_opaque (b1)->arc_next, b1);
+               }
+
+             iph_offset0 = vnet_buffer (b0)->ip.save_rewrite_length;
+             iph_offset1 = vnet_buffer (b1)->ip.save_rewrite_length;
+           }
+
+         next0 = nat_buffer_opaque (b0)->arc_next;
+         next1 = nat_buffer_opaque (b1)->arc_next;
 
          ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
                                  iph_offset0);
@@ -913,7 +927,7 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
              icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
                                           ICMP4_time_exceeded_ttl_exceeded_in_transit,
                                           0);
-             next0 = NAT_IN2OUT_ED_NEXT_ICMP_ERROR;
+             next0 = NAT_NEXT_ICMP_ERROR;
              goto trace00;
            }
 
@@ -931,7 +945,8 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
                                                      thread_index, now, vm,
                                                      node);
                  if (!s0)
-                   next0 = NAT_IN2OUT_ED_NEXT_DROP;
+                   next0 = NAT_NEXT_DROP;
+                 other_packets++;
                  goto trace00;
                }
 
@@ -940,6 +955,7 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
                  next0 = icmp_in2out_ed_slow_path
                    (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
                     next0, now, thread_index, &s0);
+                 icmp_packets++;
                  goto trace00;
                }
            }
@@ -947,13 +963,14 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
            {
              if (PREDICT_FALSE (proto0 == ~0))
                {
-                 next0 = NAT_IN2OUT_ED_NEXT_SLOW_PATH;
+                 next0 = def_slow;
                  goto trace00;
                }
 
              if (ip4_is_fragment (ip0))
                {
-                 next0 = NAT_IN2OUT_ED_NEXT_REASS;
+                 next0 = def_reass;
+                 fragments++;
                  goto trace00;
                }
 
@@ -967,7 +984,7 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
 
              if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
                {
-                 next0 = NAT_IN2OUT_ED_NEXT_SLOW_PATH;
+                 next0 = def_slow;
                  goto trace00;
                }
            }
@@ -1001,14 +1018,17 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
 
                  next0 =
                    slow_path_ed (sm, b0, rx_fib_index0, &kv0, &s0, node,
-                                 next0, thread_index, now);
+                                 next0, thread_index, now, tcp0);
+
+                 if (PREDICT_FALSE (next0 == NAT_NEXT_DROP))
+                   goto trace00;
 
-                 if (PREDICT_FALSE (next0 == NAT_IN2OUT_ED_NEXT_DROP))
+                 if (PREDICT_FALSE (!s0))
                    goto trace00;
                }
              else
                {
-                 next0 = NAT_IN2OUT_ED_NEXT_SLOW_PATH;
+                 next0 = def_slow;
                  goto trace00;
                }
            }
@@ -1033,11 +1053,11 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
                                   dst_address);
          ip0->checksum = ip_csum_fold (sum0);
 
+         old_port0 = udp0->src_port;
+         new_port0 = udp0->src_port = s0->out2in.port;
+
          if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
            {
-             old_port0 = tcp0->src_port;
-             new_port0 = tcp0->src_port = s0->out2in.port;
-
              sum0 = tcp0->checksum;
              sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
                                     dst_address);
@@ -1056,25 +1076,49 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
                }
              mss_clamping (sm, tcp0, &sum0);
              tcp0->checksum = ip_csum_fold (sum0);
+             tcp_packets++;
              if (nat44_set_tcp_session_state_i2o
                  (sm, s0, tcp0, thread_index))
                goto trace00;
            }
+         else if (udp0->checksum)
+           {
+             sum0 = udp0->checksum;
+             sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
+                                    dst_address);
+             sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
+                                    length);
+             if (PREDICT_FALSE (is_twice_nat_session (s0)))
+               {
+                 sum0 = ip_csum_update (sum0, ip0->dst_address.as_u32,
+                                        s0->ext_host_addr.as_u32,
+                                        ip4_header_t, dst_address);
+                 sum0 = ip_csum_update (sum0, tcp0->dst_port,
+                                        s0->ext_host_port, ip4_header_t,
+                                        length);
+                 udp0->dst_port = s0->ext_host_port;
+                 ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
+               }
+             udp0->checksum = ip_csum_fold (sum0);
+             udp_packets++;
+           }
          else
            {
-             udp0->src_port = s0->out2in.port;
-             udp0->checksum = 0;
              if (PREDICT_FALSE (is_twice_nat_session (s0)))
                {
                  udp0->dst_port = s0->ext_host_port;
                  ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
                }
+             udp_packets++;
            }
 
          /* Accounting */
          nat44_session_update_counters (s0, now,
                                         vlib_buffer_length_in_chain (vm,
-                                                                     b0));
+                                                                     b0),
+                                        thread_index);
+         /* Per-user LRU list maintenance */
+         nat44_session_update_lru (sm, s0, thread_index);
 
        trace00:
          if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
@@ -1090,13 +1134,7 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
                t->session_index = s0 - tsm->sessions;
            }
 
-         pkts_processed += next0 != NAT_IN2OUT_ED_NEXT_DROP;
-
-
-         next1 = NAT_IN2OUT_ED_NEXT_LOOKUP;
-
-         if (is_output_feature)
-           iph_offset1 = vnet_buffer (b1)->ip.save_rewrite_length;
+         pkts_processed += next0 == nat_buffer_opaque (b0)->arc_next;
 
          ip1 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b1) +
                                  iph_offset1);
@@ -1112,7 +1150,7 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
              icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded,
                                           ICMP4_time_exceeded_ttl_exceeded_in_transit,
                                           0);
-             next1 = NAT_IN2OUT_ED_NEXT_ICMP_ERROR;
+             next1 = NAT_NEXT_ICMP_ERROR;
              goto trace01;
            }
 
@@ -1130,7 +1168,8 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
                                                      thread_index, now, vm,
                                                      node);
                  if (!s1)
-                   next1 = NAT_IN2OUT_ED_NEXT_DROP;
+                   next1 = NAT_NEXT_DROP;
+                 other_packets++;
                  goto trace01;
                }
 
@@ -1139,6 +1178,7 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
                  next1 = icmp_in2out_ed_slow_path
                    (sm, b1, ip1, icmp1, sw_if_index1, rx_fib_index1, node,
                     next1, now, thread_index, &s1);
+                 icmp_packets++;
                  goto trace01;
                }
            }
@@ -1146,13 +1186,14 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
            {
              if (PREDICT_FALSE (proto1 == ~0))
                {
-                 next1 = NAT_IN2OUT_ED_NEXT_SLOW_PATH;
+                 next1 = def_slow;
                  goto trace01;
                }
 
              if (ip4_is_fragment (ip1))
                {
-                 next1 = NAT_IN2OUT_ED_NEXT_REASS;
+                 next1 = def_reass;
+                 fragments++;
                  goto trace01;
                }
 
@@ -1166,7 +1207,7 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
 
              if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
                {
-                 next1 = NAT_IN2OUT_ED_NEXT_SLOW_PATH;
+                 next1 = def_slow;
                  goto trace01;
                }
            }
@@ -1200,14 +1241,17 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
 
                  next1 =
                    slow_path_ed (sm, b1, rx_fib_index1, &kv1, &s1, node,
-                                 next1, thread_index, now);
+                                 next1, thread_index, now, tcp1);
+
+                 if (PREDICT_FALSE (next1 == NAT_NEXT_DROP))
+                   goto trace01;
 
-                 if (PREDICT_FALSE (next1 == NAT_IN2OUT_ED_NEXT_DROP))
+                 if (PREDICT_FALSE (!s1))
                    goto trace01;
                }
              else
                {
-                 next1 = NAT_IN2OUT_ED_NEXT_SLOW_PATH;
+                 next1 = def_slow;
                  goto trace01;
                }
            }
@@ -1232,11 +1276,11 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
                                   dst_address);
          ip1->checksum = ip_csum_fold (sum1);
 
+         old_port1 = udp1->src_port;
+         new_port1 = udp1->src_port = s1->out2in.port;
+
          if (PREDICT_TRUE (proto1 == SNAT_PROTOCOL_TCP))
            {
-             old_port1 = tcp1->src_port;
-             new_port1 = tcp1->src_port = s1->out2in.port;
-
              sum1 = tcp1->checksum;
              sum1 = ip_csum_update (sum1, old_addr1, new_addr1, ip4_header_t,
                                     dst_address);
@@ -1255,25 +1299,49 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
                }
              tcp1->checksum = ip_csum_fold (sum1);
              mss_clamping (sm, tcp1, &sum1);
+             tcp_packets++;
              if (nat44_set_tcp_session_state_i2o
                  (sm, s1, tcp1, thread_index))
                goto trace01;
            }
+         else if (udp1->checksum)
+           {
+             sum1 = udp1->checksum;
+             sum1 = ip_csum_update (sum1, old_addr1, new_addr1, ip4_header_t,
+                                    dst_address);
+             sum1 = ip_csum_update (sum1, old_port1, new_port1, ip4_header_t,
+                                    length);
+
+             if (PREDICT_FALSE (is_twice_nat_session (s1)))
+               {
+                 sum1 = ip_csum_update (sum1, ip1->dst_address.as_u32,
+                                        s1->ext_host_addr.as_u32,
+                                        ip4_header_t, dst_address);
+                 sum1 = ip_csum_update (sum1, tcp1->dst_port,
+                                        s1->ext_host_port, ip4_header_t,
+                                        length);
+                 udp1->dst_port = s1->ext_host_port;
+                 ip1->dst_address.as_u32 = s1->ext_host_addr.as_u32;
+               }
+             udp1->checksum = ip_csum_fold (sum1);
+             udp_packets++;
+           }
          else
            {
-             udp1->src_port = s1->out2in.port;
-             udp1->checksum = 0;
              if (PREDICT_FALSE (is_twice_nat_session (s1)))
                {
                  udp1->dst_port = s1->ext_host_port;
                  ip1->dst_address.as_u32 = s1->ext_host_addr.as_u32;
                }
+             udp_packets++;
            }
 
          /* Accounting */
          nat44_session_update_counters (s1, now,
-                                        vlib_buffer_length_in_chain (vm,
-                                                                     b1));
+                                        vlib_buffer_length_in_chain (vm, b1),
+                                        thread_index);
+         /* Per-user LRU list maintenance */
+         nat44_session_update_lru (sm, s1, thread_index);
 
        trace01:
          if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
@@ -1289,7 +1357,8 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
                t->session_index = s1 - tsm->sessions;
            }
 
-         pkts_processed += next1 != NAT_IN2OUT_ED_NEXT_DROP;
+         pkts_processed += next1 == nat_buffer_opaque (b1)->arc_next;
+
 
          /* verify speculative enqueues, maybe switch current next frame */
          vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
@@ -1321,10 +1390,18 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
          n_left_to_next -= 1;
 
          b0 = vlib_get_buffer (vm, bi0);
-         next0 = NAT_IN2OUT_ED_NEXT_LOOKUP;
 
          if (is_output_feature)
-           iph_offset0 = vnet_buffer (b0)->ip.save_rewrite_length;
+           {
+             // output feature fast path is enabled on the arc
+             // we need new arc_next feature
+             if (PREDICT_TRUE (!is_slow_path))
+               vnet_feature_next (&nat_buffer_opaque (b0)->arc_next, b0);
+
+             iph_offset0 = vnet_buffer (b0)->ip.save_rewrite_length;
+           }
+
+         next0 = nat_buffer_opaque (b0)->arc_next;
 
          ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
                                  iph_offset0);
@@ -1340,7 +1417,7 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
              icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
                                           ICMP4_time_exceeded_ttl_exceeded_in_transit,
                                           0);
-             next0 = NAT_IN2OUT_ED_NEXT_ICMP_ERROR;
+             next0 = NAT_NEXT_ICMP_ERROR;
              goto trace0;
            }
 
@@ -1358,7 +1435,8 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
                                                      thread_index, now, vm,
                                                      node);
                  if (!s0)
-                   next0 = NAT_IN2OUT_ED_NEXT_DROP;
+                   next0 = NAT_NEXT_DROP;
+                 other_packets++;
                  goto trace0;
                }
 
@@ -1367,6 +1445,7 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
                  next0 = icmp_in2out_ed_slow_path
                    (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
                     next0, now, thread_index, &s0);
+                 icmp_packets++;
                  goto trace0;
                }
            }
@@ -1374,13 +1453,14 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
            {
              if (PREDICT_FALSE (proto0 == ~0))
                {
-                 next0 = NAT_IN2OUT_ED_NEXT_SLOW_PATH;
+                 next0 = def_slow;
                  goto trace0;
                }
 
              if (ip4_is_fragment (ip0))
                {
-                 next0 = NAT_IN2OUT_ED_NEXT_REASS;
+                 next0 = def_reass;
+                 fragments++;
                  goto trace0;
                }
 
@@ -1394,7 +1474,7 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
 
              if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
                {
-                 next0 = NAT_IN2OUT_ED_NEXT_SLOW_PATH;
+                 next0 = def_slow;
                  goto trace0;
                }
            }
@@ -1428,14 +1508,17 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
 
                  next0 =
                    slow_path_ed (sm, b0, rx_fib_index0, &kv0, &s0, node,
-                                 next0, thread_index, now);
+                                 next0, thread_index, now, tcp0);
 
-                 if (PREDICT_FALSE (next0 == NAT_IN2OUT_ED_NEXT_DROP))
+                 if (PREDICT_FALSE (next0 == NAT_NEXT_DROP))
+                   goto trace0;
+
+                 if (PREDICT_FALSE (!s0))
                    goto trace0;
                }
              else
                {
-                 next0 = NAT_IN2OUT_ED_NEXT_SLOW_PATH;
+                 next0 = def_slow;
                  goto trace0;
                }
            }
@@ -1460,11 +1543,11 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
                                   dst_address);
          ip0->checksum = ip_csum_fold (sum0);
 
+         old_port0 = udp0->src_port;
+         new_port0 = udp0->src_port = s0->out2in.port;
+
          if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
            {
-             old_port0 = tcp0->src_port;
-             new_port0 = tcp0->src_port = s0->out2in.port;
-
              sum0 = tcp0->checksum;
              sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
                                     dst_address);
@@ -1483,25 +1566,48 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
                }
              mss_clamping (sm, tcp0, &sum0);
              tcp0->checksum = ip_csum_fold (sum0);
+             tcp_packets++;
              if (nat44_set_tcp_session_state_i2o
                  (sm, s0, tcp0, thread_index))
                goto trace0;
            }
+         else if (udp0->checksum)
+           {
+             sum0 = udp0->checksum;
+             sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
+                                    dst_address);
+             sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
+                                    length);
+             if (PREDICT_FALSE (is_twice_nat_session (s0)))
+               {
+                 sum0 = ip_csum_update (sum0, ip0->dst_address.as_u32,
+                                        s0->ext_host_addr.as_u32,
+                                        ip4_header_t, dst_address);
+                 sum0 = ip_csum_update (sum0, tcp0->dst_port,
+                                        s0->ext_host_port, ip4_header_t,
+                                        length);
+                 udp0->dst_port = s0->ext_host_port;
+                 ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
+               }
+             udp0->checksum = ip_csum_fold (sum0);
+             udp_packets++;
+           }
          else
            {
-             udp0->src_port = s0->out2in.port;
-             udp0->checksum = 0;
              if (PREDICT_FALSE (is_twice_nat_session (s0)))
                {
                  udp0->dst_port = s0->ext_host_port;
                  ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
                }
+             udp_packets++;
            }
 
          /* Accounting */
          nat44_session_update_counters (s0, now,
-                                        vlib_buffer_length_in_chain (vm,
-                                                                     b0));
+                                        vlib_buffer_length_in_chain (vm, b0),
+                                        thread_index);
+         /* Per-user LRU list maintenance */
+         nat44_session_update_lru (sm, s0, thread_index);
 
        trace0:
          if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
@@ -1517,7 +1623,7 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
                t->session_index = s0 - tsm->sessions;
            }
 
-         pkts_processed += next0 != NAT_IN2OUT_ED_NEXT_DROP;
+         pkts_processed += next0 == nat_buffer_opaque (b0)->arc_next;
 
          /* verify speculative enqueue, maybe switch current next frame */
          vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
@@ -1531,137 +1637,22 @@ nat44_ed_in2out_node_fn_inline (vlib_main_t * vm,
   vlib_node_increment_counter (vm, stats_node_index,
                               NAT_IN2OUT_ED_ERROR_IN2OUT_PACKETS,
                               pkts_processed);
-  return frame->n_vectors;
-}
-
-static uword
-nat44_ed_in2out_fast_path_fn (vlib_main_t * vm,
-                             vlib_node_runtime_t * node,
-                             vlib_frame_t * frame)
-{
-  return nat44_ed_in2out_node_fn_inline (vm, node, frame, 0, 0);
-}
-
-/* *INDENT-OFF* */
-VLIB_REGISTER_NODE (nat44_ed_in2out_node) = {
-  .function = nat44_ed_in2out_fast_path_fn,
-  .name = "nat44-ed-in2out",
-  .vector_size = sizeof (u32),
-  .format_trace = format_nat_in2out_ed_trace,
-  .type = VLIB_NODE_TYPE_INTERNAL,
-  .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
-  .error_strings = nat_in2out_ed_error_strings,
-  .runtime_data_bytes = sizeof (snat_runtime_t),
-  .n_next_nodes = NAT_IN2OUT_ED_N_NEXT,
-  .next_nodes = {
-    [NAT_IN2OUT_ED_NEXT_DROP] = "error-drop",
-    [NAT_IN2OUT_ED_NEXT_LOOKUP] = "ip4-lookup",
-    [NAT_IN2OUT_ED_NEXT_SLOW_PATH] = "nat44-ed-in2out-slowpath",
-    [NAT_IN2OUT_ED_NEXT_ICMP_ERROR] = "ip4-icmp-error",
-    [NAT_IN2OUT_ED_NEXT_REASS] = "nat44-ed-in2out-reass",
-  },
-};
-/* *INDENT-ON* */
-
-VLIB_NODE_FUNCTION_MULTIARCH (nat44_ed_in2out_node,
-                             nat44_ed_in2out_fast_path_fn);
-
-static uword
-nat44_ed_in2out_output_fast_path_fn (vlib_main_t * vm,
-                                    vlib_node_runtime_t * node,
-                                    vlib_frame_t * frame)
-{
-  return nat44_ed_in2out_node_fn_inline (vm, node, frame, 0, 1);
-}
-
-/* *INDENT-OFF* */
-VLIB_REGISTER_NODE (nat44_ed_in2out_output_node) = {
-  .function = nat44_ed_in2out_output_fast_path_fn,
-  .name = "nat44-ed-in2out-output",
-  .vector_size = sizeof (u32),
-  .format_trace = format_nat_in2out_ed_trace,
-  .type = VLIB_NODE_TYPE_INTERNAL,
-  .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
-  .error_strings = nat_in2out_ed_error_strings,
-  .runtime_data_bytes = sizeof (snat_runtime_t),
-  .n_next_nodes = NAT_IN2OUT_ED_N_NEXT,
-  .next_nodes = {
-    [NAT_IN2OUT_ED_NEXT_DROP] = "error-drop",
-    [NAT_IN2OUT_ED_NEXT_LOOKUP] = "interface-output",
-    [NAT_IN2OUT_ED_NEXT_SLOW_PATH] = "nat44-ed-in2out-output-slowpath",
-    [NAT_IN2OUT_ED_NEXT_ICMP_ERROR] = "ip4-icmp-error",
-    [NAT_IN2OUT_ED_NEXT_REASS] = "nat44-ed-in2out-reass-output",
-  },
-};
-/* *INDENT-ON* */
-
-VLIB_NODE_FUNCTION_MULTIARCH (nat44_ed_in2out_output_node,
-                             nat44_ed_in2out_output_fast_path_fn);
-
-static uword
-nat44_ed_in2out_slow_path_fn (vlib_main_t * vm,
-                             vlib_node_runtime_t * node,
-                             vlib_frame_t * frame)
-{
-  return nat44_ed_in2out_node_fn_inline (vm, node, frame, 1, 0);
-}
-
-/* *INDENT-OFF* */
-VLIB_REGISTER_NODE (nat44_ed_in2out_slowpath_node) = {
-  .function = nat44_ed_in2out_slow_path_fn,
-  .name = "nat44-ed-in2out-slowpath",
-  .vector_size = sizeof (u32),
-  .format_trace = format_nat_in2out_ed_trace,
-  .type = VLIB_NODE_TYPE_INTERNAL,
-  .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
-  .error_strings = nat_in2out_ed_error_strings,
-  .runtime_data_bytes = sizeof (snat_runtime_t),
-  .n_next_nodes = NAT_IN2OUT_ED_N_NEXT,
-  .next_nodes = {
-    [NAT_IN2OUT_ED_NEXT_DROP] = "error-drop",
-    [NAT_IN2OUT_ED_NEXT_LOOKUP] = "ip4-lookup",
-    [NAT_IN2OUT_ED_NEXT_SLOW_PATH] = "nat44-ed-in2out-slowpath",
-    [NAT_IN2OUT_ED_NEXT_ICMP_ERROR] = "ip4-icmp-error",
-    [NAT_IN2OUT_ED_NEXT_REASS] = "nat44-ed-in2out-reass",
-  },
-};
-/* *INDENT-ON* */
-
-VLIB_NODE_FUNCTION_MULTIARCH (nat44_ed_in2out_slowpath_node,
-                             nat44_ed_in2out_slow_path_fn);
+  vlib_node_increment_counter (vm, stats_node_index,
+                              NAT_IN2OUT_ED_ERROR_TCP_PACKETS, tcp_packets);
+  vlib_node_increment_counter (vm, stats_node_index,
+                              NAT_IN2OUT_ED_ERROR_UDP_PACKETS, udp_packets);
+  vlib_node_increment_counter (vm, stats_node_index,
+                              NAT_IN2OUT_ED_ERROR_ICMP_PACKETS,
+                              icmp_packets);
+  vlib_node_increment_counter (vm, stats_node_index,
+                              NAT_IN2OUT_ED_ERROR_OTHER_PACKETS,
+                              other_packets);
+  vlib_node_increment_counter (vm, stats_node_index,
+                              NAT_IN2OUT_ED_ERROR_FRAGMENTS, fragments);
 
-static uword
-nat44_ed_in2out_output_slow_path_fn (vlib_main_t * vm,
-                                    vlib_node_runtime_t * node,
-                                    vlib_frame_t * frame)
-{
-  return nat44_ed_in2out_node_fn_inline (vm, node, frame, 1, 1);
+  return frame->n_vectors;
 }
 
-/* *INDENT-OFF* */
-VLIB_REGISTER_NODE (nat44_ed_in2out_output_slowpath_node) = {
-  .function = nat44_ed_in2out_output_slow_path_fn,
-  .name = "nat44-ed-in2out-output-slowpath",
-  .vector_size = sizeof (u32),
-  .format_trace = format_nat_in2out_ed_trace,
-  .type = VLIB_NODE_TYPE_INTERNAL,
-  .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
-  .error_strings = nat_in2out_ed_error_strings,
-  .runtime_data_bytes = sizeof (snat_runtime_t),
-  .n_next_nodes = NAT_IN2OUT_ED_N_NEXT,
-  .next_nodes = {
-    [NAT_IN2OUT_ED_NEXT_DROP] = "error-drop",
-    [NAT_IN2OUT_ED_NEXT_LOOKUP] = "interface-output",
-    [NAT_IN2OUT_ED_NEXT_SLOW_PATH] = "nat44-ed-in2out-output-slowpath",
-    [NAT_IN2OUT_ED_NEXT_ICMP_ERROR] = "ip4-icmp-error",
-    [NAT_IN2OUT_ED_NEXT_REASS] = "nat44-ed-in2out-reass",
-  },
-};
-/* *INDENT-ON* */
-
-VLIB_NODE_FUNCTION_MULTIARCH (nat44_ed_in2out_output_slowpath_node,
-                             nat44_ed_in2out_output_slow_path_fn);
-
 static inline uword
 nat44_ed_in2out_reass_node_fn_inline (vlib_main_t * vm,
                                      vlib_node_runtime_t * node,
@@ -1669,8 +1660,8 @@ nat44_ed_in2out_reass_node_fn_inline (vlib_main_t * vm,
                                      int is_output_feature)
 {
   u32 n_left_from, *from, *to_next;
-  nat_in2out_ed_next_t next_index;
-  u32 pkts_processed = 0;
+  nat_next_t next_index;
+  u32 pkts_processed = 0, cached_fragments = 0;
   snat_main_t *sm = &snat_main;
   f64 now = vlib_time_now (vm);
   u32 thread_index = vm->thread_index;
@@ -1716,7 +1707,7 @@ nat44_ed_in2out_reass_node_fn_inline (vlib_main_t * vm,
 
          b0 = vlib_get_buffer (vm, bi0);
 
-         next0 = NAT_IN2OUT_ED_NEXT_LOOKUP;
+         next0 = nat_buffer_opaque (b0)->arc_next;
 
          sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
          rx_fib_index0 =
@@ -1725,7 +1716,7 @@ nat44_ed_in2out_reass_node_fn_inline (vlib_main_t * vm,
 
          if (PREDICT_FALSE (nat_reass_is_drop_frag (0)))
            {
-             next0 = NAT_IN2OUT_ED_NEXT_DROP;
+             next0 = NAT_NEXT_DROP;
              b0->error = node->errors[NAT_IN2OUT_ED_ERROR_DROP_FRAGMENT];
              goto trace0;
            }
@@ -1749,9 +1740,9 @@ nat44_ed_in2out_reass_node_fn_inline (vlib_main_t * vm,
 
          if (PREDICT_FALSE (!reass0))
            {
-             next0 = NAT_IN2OUT_ED_NEXT_DROP;
+             next0 = NAT_NEXT_DROP;
              b0->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_REASS];
-             nat_log_notice ("maximum reassemblies exceeded");
+             nat_elog_notice ("maximum reassemblies exceeded");
              goto trace0;
            }
 
@@ -1772,7 +1763,7 @@ nat44_ed_in2out_reass_node_fn_inline (vlib_main_t * vm,
                    (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
                     next0, now, thread_index, &s0);
 
-                 if (PREDICT_TRUE (next0 != NAT_IN2OUT_ED_NEXT_DROP))
+                 if (PREDICT_TRUE (next0 != NAT_NEXT_DROP))
                    {
                      if (s0)
                        reass0->sess_index = s0 - per_thread_data->sessions;
@@ -1822,11 +1813,18 @@ nat44_ed_in2out_reass_node_fn_inline (vlib_main_t * vm,
                    }
 
                  next0 = slow_path_ed (sm, b0, rx_fib_index0, &kv0,
-                                       &s0, node, next0, thread_index, now);
+                                       &s0, node, next0, thread_index, now,
+                                       tcp0);
 
-                 if (PREDICT_FALSE (next0 == NAT_IN2OUT_ED_NEXT_DROP))
+                 if (PREDICT_FALSE (next0 == NAT_NEXT_DROP))
                    goto trace0;
 
+                 if (PREDICT_FALSE (!s0))
+                   {
+                     reass0->flags |= NAT_REASS_FLAG_ED_DONT_TRANSLATE;
+                     goto trace0;
+                   }
+
                  reass0->sess_index = s0 - per_thread_data->sessions;
                }
              else
@@ -1844,12 +1842,12 @@ nat44_ed_in2out_reass_node_fn_inline (vlib_main_t * vm,
              if (PREDICT_FALSE (reass0->sess_index == (u32) ~ 0))
                {
                  if (nat_ip4_reass_add_fragment
-                     (reass0, bi0, &fragments_to_drop))
+                     (thread_index, reass0, bi0, &fragments_to_drop))
                    {
                      b0->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_FRAG];
-                     nat_log_notice
+                     nat_elog_notice
                        ("maximum fragments per reassembly exceeded");
-                     next0 = NAT_IN2OUT_ED_NEXT_DROP;
+                     next0 = NAT_NEXT_DROP;
                      goto trace0;
                    }
                  cached0 = 1;
@@ -1877,12 +1875,11 @@ nat44_ed_in2out_reass_node_fn_inline (vlib_main_t * vm,
 
          if (PREDICT_FALSE (ip4_is_first_fragment (ip0)))
            {
+             old_port0 = udp0->src_port;
+             new_port0 = udp0->src_port = s0->out2in.port;
+
              if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
                {
-                 old_port0 = tcp0->src_port;
-                 tcp0->src_port = s0->out2in.port;
-                 new_port0 = tcp0->src_port;
-
                  sum0 = tcp0->checksum;
                  sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
                                         ip4_header_t,
@@ -1903,11 +1900,30 @@ nat44_ed_in2out_reass_node_fn_inline (vlib_main_t * vm,
                    }
                  tcp0->checksum = ip_csum_fold (sum0);
                }
+             else if (udp0->checksum)
+               {
+                 sum0 = udp0->checksum;
+                 sum0 =
+                   ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
+                                   dst_address);
+                 sum0 =
+                   ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
+                                   length);
+                 if (PREDICT_FALSE (is_twice_nat_session (s0)))
+                   {
+                     sum0 = ip_csum_update (sum0, ip0->dst_address.as_u32,
+                                            s0->ext_host_addr.as_u32,
+                                            ip4_header_t, dst_address);
+                     sum0 = ip_csum_update (sum0, tcp0->dst_port,
+                                            s0->ext_host_port, ip4_header_t,
+                                            length);
+                     udp0->dst_port = s0->ext_host_port;
+                     ip0->dst_address.as_u32 = s0->ext_host_addr.as_u32;
+                   }
+                 udp0->checksum = ip_csum_fold (sum0);
+               }
              else
                {
-                 old_port0 = udp0->src_port;
-                 udp0->src_port = s0->out2in.port;
-                 udp0->checksum = 0;
                  if (PREDICT_FALSE (is_twice_nat_session (s0)))
                    {
                      udp0->dst_port = s0->ext_host_port;
@@ -1917,16 +1933,15 @@ nat44_ed_in2out_reass_node_fn_inline (vlib_main_t * vm,
            }
 
          /* Hairpinning */
-         if (PREDICT_TRUE (proto0 != SNAT_PROTOCOL_ICMP))
-           nat44_reass_hairpinning (sm, b0, ip0, s0->out2in.port,
-                                    s0->ext_host_port, proto0, 1);
-         else
-           snat_icmp_hairpinning (sm, b0, ip0, icmp0, 1);
+         nat44_reass_hairpinning (sm, b0, ip0, s0->out2in.port,
+                                  s0->ext_host_port, proto0, 1);
 
          /* Accounting */
          nat44_session_update_counters (s0, now,
-                                        vlib_buffer_length_in_chain (vm,
-                                                                     b0));
+                                        vlib_buffer_length_in_chain (vm, b0),
+                                        thread_index);
+         /* Per-user LRU list maintenance */
+         nat44_session_update_lru (sm, s0, thread_index);
 
        trace0:
          if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
@@ -1943,10 +1958,11 @@ nat44_ed_in2out_reass_node_fn_inline (vlib_main_t * vm,
            {
              n_left_to_next++;
              to_next--;
+             cached_fragments++;
            }
          else
            {
-             pkts_processed += next0 != NAT_IN2OUT_ED_NEXT_DROP;
+             pkts_processed += next0 == nat_buffer_opaque (b0)->arc_next;
 
              /* verify speculative enqueue, maybe switch current next frame */
              vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
@@ -1960,17 +1976,16 @@ nat44_ed_in2out_reass_node_fn_inline (vlib_main_t * vm,
              u32 len = vec_len (fragments_to_loopback);
              if (len <= VLIB_FRAME_SIZE)
                {
-                 clib_memcpy (from, fragments_to_loopback,
-                              sizeof (u32) * len);
+                 clib_memcpy_fast (from, fragments_to_loopback,
+                                   sizeof (u32) * len);
                  n_left_from = len;
                  vec_reset_length (fragments_to_loopback);
                }
              else
                {
-                 clib_memcpy (from,
-                              fragments_to_loopback + (len -
-                                                       VLIB_FRAME_SIZE),
-                              sizeof (u32) * VLIB_FRAME_SIZE);
+                 clib_memcpy_fast (from, fragments_to_loopback +
+                                   (len - VLIB_FRAME_SIZE),
+                                   sizeof (u32) * VLIB_FRAME_SIZE);
                  n_left_from = VLIB_FRAME_SIZE;
                  _vec_len (fragments_to_loopback) = len - VLIB_FRAME_SIZE;
                }
@@ -1980,80 +1995,169 @@ nat44_ed_in2out_reass_node_fn_inline (vlib_main_t * vm,
       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
     }
 
-  vlib_node_increment_counter (vm, nat44_ed_in2out_reass_node.index,
-                              NAT_IN2OUT_ED_ERROR_IN2OUT_PACKETS,
+  vlib_node_increment_counter (vm, sm->ed_in2out_reass_node_index,
+                              NAT_IN2OUT_ED_ERROR_PROCESSED_FRAGMENTS,
                               pkts_processed);
+  vlib_node_increment_counter (vm, sm->ed_in2out_reass_node_index,
+                              NAT_IN2OUT_ED_ERROR_CACHED_FRAGMENTS,
+                              cached_fragments);
 
   nat_send_all_to_node (vm, fragments_to_drop, node,
                        &node->errors[NAT_IN2OUT_ED_ERROR_DROP_FRAGMENT],
-                       NAT_IN2OUT_ED_NEXT_DROP);
+                       NAT_NEXT_DROP);
 
   vec_free (fragments_to_drop);
   vec_free (fragments_to_loopback);
   return frame->n_vectors;
 }
 
-static uword
-nat44_ed_in2out_reass_node_fn (vlib_main_t * vm,
-                              vlib_node_runtime_t * node,
-                              vlib_frame_t * frame)
+VLIB_NODE_FN (nat44_ed_in2out_node) (vlib_main_t * vm,
+                                    vlib_node_runtime_t * node,
+                                    vlib_frame_t * frame)
+{
+  return nat44_ed_in2out_node_fn_inline (vm, node, frame, 0, 0);
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (nat44_ed_in2out_node) = {
+  .name = "nat44-ed-in2out",
+  .vector_size = sizeof (u32),
+  .sibling_of = "nat-default",
+  .format_trace = format_nat_in2out_ed_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
+  .error_strings = nat_in2out_ed_error_strings,
+  .runtime_data_bytes = sizeof (snat_runtime_t),
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FN (nat44_ed_in2out_output_node) (vlib_main_t * vm,
+                                           vlib_node_runtime_t * node,
+                                           vlib_frame_t * frame)
+{
+  return nat44_ed_in2out_node_fn_inline (vm, node, frame, 0, 1);
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (nat44_ed_in2out_output_node) = {
+  .name = "nat44-ed-in2out-output",
+  .vector_size = sizeof (u32),
+  .sibling_of = "nat-default",
+  .format_trace = format_nat_in2out_ed_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
+  .error_strings = nat_in2out_ed_error_strings,
+  .runtime_data_bytes = sizeof (snat_runtime_t),
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FN (nat44_ed_in2out_slowpath_node) (vlib_main_t * vm,
+                                             vlib_node_runtime_t * node,
+                                             vlib_frame_t * frame)
+{
+  return nat44_ed_in2out_node_fn_inline (vm, node, frame, 1, 0);
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (nat44_ed_in2out_slowpath_node) = {
+  .name = "nat44-ed-in2out-slowpath",
+  .vector_size = sizeof (u32),
+  .sibling_of = "nat-default",
+  .format_trace = format_nat_in2out_ed_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
+  .error_strings = nat_in2out_ed_error_strings,
+  .runtime_data_bytes = sizeof (snat_runtime_t),
+};
+/* *INDENT-ON* */
+
+VLIB_NODE_FN (nat44_ed_in2out_output_slowpath_node) (vlib_main_t * vm,
+                                                    vlib_node_runtime_t *
+                                                    node,
+                                                    vlib_frame_t * frame)
+{
+  return nat44_ed_in2out_node_fn_inline (vm, node, frame, 1, 1);
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (nat44_ed_in2out_output_slowpath_node) = {
+  .name = "nat44-ed-in2out-output-slowpath",
+  .vector_size = sizeof (u32),
+  .sibling_of = "nat-default",
+  .format_trace = format_nat_in2out_ed_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
+  .error_strings = nat_in2out_ed_error_strings,
+  .runtime_data_bytes = sizeof (snat_runtime_t),
+};
+/* *INDENT-ON* */
+
+
+VLIB_NODE_FN (nat44_ed_in2out_reass_node) (vlib_main_t * vm,
+                                          vlib_node_runtime_t * node,
+                                          vlib_frame_t * frame)
 {
   return nat44_ed_in2out_reass_node_fn_inline (vm, node, frame, 0);
 }
 
 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (nat44_ed_in2out_reass_node) = {
-  .function = nat44_ed_in2out_reass_node_fn,
   .name = "nat44-ed-in2out-reass",
   .vector_size = sizeof (u32),
+  .sibling_of = "nat-default",
   .format_trace = format_nat44_reass_trace,
   .type = VLIB_NODE_TYPE_INTERNAL,
   .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
   .error_strings = nat_in2out_ed_error_strings,
-  .n_next_nodes = NAT_IN2OUT_ED_N_NEXT,
-  .next_nodes = {
-    [NAT_IN2OUT_ED_NEXT_DROP] = "error-drop",
-    [NAT_IN2OUT_ED_NEXT_LOOKUP] = "ip4-lookup",
-    [NAT_IN2OUT_ED_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
-    [NAT_IN2OUT_ED_NEXT_ICMP_ERROR] = "ip4-icmp-error",
-    [NAT_IN2OUT_ED_NEXT_REASS] = "nat44-ed-in2out-reass",
-  },
 };
 /* *INDENT-ON* */
 
-VLIB_NODE_FUNCTION_MULTIARCH (nat44_ed_in2out_reass_node,
-                             nat44_ed_in2out_reass_node_fn);
-
-static uword
-nat44_ed_in2out_reass_output_node_fn (vlib_main_t * vm,
-                                     vlib_node_runtime_t * node,
-                                     vlib_frame_t * frame)
+VLIB_NODE_FN (nat44_ed_in2out_reass_output_node) (vlib_main_t * vm,
+                                                 vlib_node_runtime_t * node,
+                                                 vlib_frame_t * frame)
 {
   return nat44_ed_in2out_reass_node_fn_inline (vm, node, frame, 1);
 }
 
 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (nat44_ed_in2out_reass_output_node) = {
-  .function = nat44_ed_in2out_reass_output_node_fn,
   .name = "nat44-ed-in2out-reass-output",
   .vector_size = sizeof (u32),
+  .sibling_of = "nat-default",
   .format_trace = format_nat44_reass_trace,
   .type = VLIB_NODE_TYPE_INTERNAL,
   .n_errors = ARRAY_LEN (nat_in2out_ed_error_strings),
   .error_strings = nat_in2out_ed_error_strings,
-  .n_next_nodes = NAT_IN2OUT_ED_N_NEXT,
-  .next_nodes = {
-    [NAT_IN2OUT_ED_NEXT_DROP] = "error-drop",
-    [NAT_IN2OUT_ED_NEXT_LOOKUP] = "interface-output",
-    [NAT_IN2OUT_ED_NEXT_SLOW_PATH] = "nat44-in2out-slowpath",
-    [NAT_IN2OUT_ED_NEXT_ICMP_ERROR] = "ip4-icmp-error",
-    [NAT_IN2OUT_ED_NEXT_REASS] = "nat44-ed-in2out-reass",
-  },
 };
 /* *INDENT-ON* */
 
-VLIB_NODE_FUNCTION_MULTIARCH (nat44_ed_in2out_reass_output_node,
-                             nat44_ed_in2out_reass_output_node_fn);
+static u8 *
+format_nat_pre_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
+  return format (s, "in2out next_index %d", t->next_index);
+}
+
+VLIB_NODE_FN (nat_pre_in2out_node) (vlib_main_t * vm,
+                                   vlib_node_runtime_t * node,
+                                   vlib_frame_t * frame)
+{
+  return nat_pre_node_fn_inline (vm, node, frame,
+                                NAT_NEXT_IN2OUT_ED_FAST_PATH);
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (nat_pre_in2out_node) = {
+  .name = "nat-pre-in2out",
+  .vector_size = sizeof (u32),
+  .sibling_of = "nat-default",
+  .format_trace = format_nat_pre_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = 0,
+};
+/* *INDENT-ON* */
 
 /*
  * fd.io coding-style-patch-verification: ON