nat: Final NAT44 EI/ED split patch

This patch achieves complete separation of
endpoint-dependent and endpoint-independent IPv4 NAT
features. Some common stuff is also moved to NAT
library.

Type: refactor

Change-Id: I52468b7e2b5ac28958a2baf8e2ea01787322e801
Signed-off-by: Filip Varga <fivarga@cisco.com>

1 files changed, 0 insertions, 1448 deletions

diff --git a/src/plugins/nat/out2in_ed.c b/src/plugins/nat/out2in_ed.c
deleted file mode 100644
index d6beadc61bc..00000000000
--- a/src/plugins/nat/out2in_ed.c
+++ /dev/null
@@ -1,1448 +0,0 @@
-/*
- * Copyright (c) 2018 Cisco and/or its affiliates.
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at:
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-/**
- * @file
- * @brief NAT44 endpoint-dependent outside to inside network translation
- */
-
-#include <vlib/vlib.h>
-#include <vnet/vnet.h>
-#include <vnet/ip/ip.h>
-#include <vnet/ethernet/ethernet.h>
-#include <vnet/fib/ip4_fib.h>
-#include <vnet/udp/udp_local.h>
-#include <vppinfra/error.h>
-#include <nat/nat.h>
-#include <nat/lib/ipfix_logging.h>
-#include <nat/nat_inlines.h>
-#include <nat/nat44/inlines.h>
-#include <nat/lib/nat_syslog.h>
-#include <nat/nat44/ed_inlines.h>
-
-static char *nat_out2in_ed_error_strings[] = {
-#define _(sym,string) string,
-  foreach_nat_out2in_ed_error
-#undef _
-};
-
-typedef struct
-{
-  u32 sw_if_index;
-  u32 next_index;
-  u32 session_index;
-  nat_translation_error_e translation_error;
-  nat_6t_flow_t i2of;
-  nat_6t_flow_t o2if;
-  clib_bihash_kv_16_8_t search_key;
-  u8 is_slow_path;
-  u8 translation_via_i2of;
-  u8 lookup_skipped;
-} nat44_ed_out2in_trace_t;
-
-static u8 *
-format_nat44_ed_out2in_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 *);
-  nat44_ed_out2in_trace_t *t = va_arg (*args, nat44_ed_out2in_trace_t *);
-  char *tag;
-
-  tag =
-    t->is_slow_path ? "NAT44_OUT2IN_ED_SLOW_PATH" :
-    "NAT44_OUT2IN_ED_FAST_PATH";
-
-  s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
-	      t->sw_if_index, t->next_index, t->session_index);
-  if (~0 != t->session_index)
-    {
-      s = format (s, ", translation result '%U' via %s",
-		  format_nat_ed_translation_error, t->translation_error,
-		  t->translation_via_i2of ? "i2of" : "o2if");
-      s = format (s, "\n  i2of %U", format_nat_6t_flow, &t->i2of);
-      s = format (s, "\n  o2if %U", format_nat_6t_flow, &t->o2if);
-    }
-  if (!t->is_slow_path)
-    {
-      if (t->lookup_skipped)
-	{
-	  s = format (s, "\n lookup skipped - cached session index used");
-	}
-      else
-	{
-	  s = format (s, "\n  search key %U", format_ed_session_kvp,
-		      &t->search_key);
-	}
-    }
-
-  return s;
-}
-
-static int
-next_src_nat (snat_main_t *sm, ip4_header_t *ip, u16 src_port, u16 dst_port,
-	      u32 thread_index, u32 rx_fib_index)
-{
-  clib_bihash_kv_16_8_t kv, value;
-
-  init_ed_k (&kv, ip->src_address, src_port, ip->dst_address, dst_port,
-	     rx_fib_index, ip->protocol);
-  if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv, &value))
-    return 1;
-
-  return 0;
-}
-
-static void create_bypass_for_fwd (snat_main_t *sm, vlib_buffer_t *b,
-				   snat_session_t *s, ip4_header_t *ip,
-				   u32 rx_fib_index, u32 thread_index);
-
-static snat_session_t *create_session_for_static_mapping_ed (
-  snat_main_t *sm, vlib_buffer_t *b, ip4_address_t i2o_addr, u16 i2o_port,
-  u32 i2o_fib_index, ip4_address_t o2i_addr, u16 o2i_port, u32 o2i_fib_index,
-  nat_protocol_t nat_proto, vlib_node_runtime_t *node, u32 rx_fib_index,
-  u32 thread_index, twice_nat_type_t twice_nat, lb_nat_type_t lb_nat, f64 now,
-  snat_static_mapping_t *mapping);
-
-static inline u32
-icmp_out2in_ed_slow_path (snat_main_t *sm, vlib_buffer_t *b, ip4_header_t *ip,
-			  icmp46_header_t *icmp, u32 sw_if_index,
-			  u32 rx_fib_index, vlib_node_runtime_t *node,
-			  u32 next, f64 now, u32 thread_index,
-			  snat_session_t **s_p)
-{
-  vlib_main_t *vm = vlib_get_main ();
-
-  ip_csum_t sum;
-  u16 checksum;
-
-  snat_session_t *s = 0;
-  u8 is_addr_only, identity_nat;
-  ip4_address_t sm_addr;
-  u16 sm_port;
-  u32 sm_fib_index;
-  snat_static_mapping_t *m;
-  u8 lookup_protocol;
-  ip4_address_t lookup_saddr, lookup_daddr;
-  u16 lookup_sport, lookup_dport;
-
-  sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
-  rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
-
-  if (nat_get_icmp_session_lookup_values (b, ip, &lookup_saddr, &lookup_sport,
-					  &lookup_daddr, &lookup_dport,
-					  &lookup_protocol))
-    {
-      b->error = node->errors[NAT_OUT2IN_ED_ERROR_UNSUPPORTED_PROTOCOL];
-      next = NAT_NEXT_DROP;
-      goto out;
-    }
-
-  if (snat_static_mapping_match (
-	sm, ip->dst_address, lookup_sport, rx_fib_index,
-	ip_proto_to_nat_proto (ip->protocol), &sm_addr, &sm_port,
-	&sm_fib_index, 1, &is_addr_only, 0, 0, 0, &identity_nat, &m))
-    {
-      // static mapping not matched
-      if (!sm->forwarding_enabled)
-	{
-	  /* Don't NAT packet aimed at the intfc address */
-	  if (!is_interface_addr (sm, node, sw_if_index,
-				  ip->dst_address.as_u32))
-	    {
-	      b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
-	      next = NAT_NEXT_DROP;
-	    }
-	}
-      else
-	{
-	  if (next_src_nat (sm, ip, lookup_sport, lookup_dport, thread_index,
-			    rx_fib_index))
-	    {
-	      next = NAT_NEXT_IN2OUT_ED_FAST_PATH;
-	    }
-	  else
-	    {
-	      create_bypass_for_fwd (sm, b, s, ip, rx_fib_index, thread_index);
-	    }
-	}
-      goto out;
-    }
-
-  if (PREDICT_FALSE (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
-		       ICMP4_echo_reply &&
-		     (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags !=
-			ICMP4_echo_request ||
-		      !is_addr_only)))
-    {
-      b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
-      next = NAT_NEXT_DROP;
-      goto out;
-    }
-
-  if (PREDICT_FALSE (identity_nat))
-    {
-      goto out;
-    }
-
-  /* Create session initiated by host from external network */
-  s = create_session_for_static_mapping_ed (
-    sm, b, sm_addr, sm_port, sm_fib_index, ip->dst_address, lookup_sport,
-    rx_fib_index, ip_proto_to_nat_proto (lookup_protocol), node, rx_fib_index,
-    thread_index, 0, 0, vlib_time_now (vm), m);
-  if (!s)
-    next = NAT_NEXT_DROP;
-
-  if (PREDICT_TRUE (!ip4_is_fragment (ip)))
-    {
-      sum = ip_incremental_checksum_buffer (
-	vm, b, (u8 *) icmp - (u8 *) vlib_buffer_get_current (b),
-	ntohs (ip->length) - ip4_header_bytes (ip), 0);
-      checksum = ~ip_csum_fold (sum);
-      if (checksum != 0 && checksum != 0xffff)
-	{
-	  next = NAT_NEXT_DROP;
-	  goto out;
-	}
-    }
-
-  if (PREDICT_TRUE (next != NAT_NEXT_DROP && s))
-    {
-      /* Accounting */
-      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);
-    }
-out:
-  if (NAT_NEXT_DROP == next && s)
-    {
-      nat_ed_session_delete (sm, s, thread_index, 1);
-      s = 0;
-    }
-  *s_p = s;
-  return next;
-}
-
-// allocate exact address based on preference
-static_always_inline int
-nat_alloc_addr_and_port_exact (snat_address_t * a,
-			       u32 thread_index,
-			       nat_protocol_t proto,
-			       ip4_address_t * addr,
-			       u16 * port,
-			       u16 port_per_thread, u32 snat_thread_index)
-{
-  u32 portnum;
-
-  switch (proto)
-    {
-#define _(N, j, n, s) \
-    case NAT_PROTOCOL_##N: \
-      if (a->busy_##n##_ports_per_thread[thread_index] < port_per_thread) \
-        { \
-          while (1) \
-            { \
-              portnum = (port_per_thread * \
-                snat_thread_index) + \
-                snat_random_port(0, port_per_thread - 1) + 1024; \
-              if (a->busy_##n##_port_refcounts[portnum]) \
-                continue; \
-	      --a->busy_##n##_port_refcounts[portnum]; \
-              a->busy_##n##_ports_per_thread[thread_index]++; \
-              a->busy_##n##_ports++; \
-              *addr = a->addr; \
-              *port = clib_host_to_net_u16(portnum); \
-              return 0; \
-            } \
-        } \
-      break;
-      foreach_nat_protocol
-#undef _
-    default:
-      nat_elog_info ("unknown protocol");
-      return 1;
-    }
-
-  /* Totally out of translations to use... */
-  nat_ipfix_logging_addresses_exhausted (thread_index, 0);
-  return 1;
-}
-
-static_always_inline int
-nat44_ed_alloc_outside_addr_and_port (snat_address_t *addresses, u32 fib_index,
-				      u32 thread_index, nat_protocol_t proto,
-				      ip4_address_t *addr, u16 *port,
-				      u16 port_per_thread,
-				      u32 snat_thread_index)
-{
-  int i;
-  snat_address_t *a, *ga = 0;
-  u32 portnum;
-
-  for (i = 0; i < vec_len (addresses); i++)
-    {
-      a = addresses + i;
-      switch (proto)
-	{
-#define _(N, j, n, s)                                                         \
-  case NAT_PROTOCOL_##N:                                                      \
-    if (a->busy_##n##_ports_per_thread[thread_index] < port_per_thread)       \
-      {                                                                       \
-	if (a->fib_index == fib_index)                                        \
-	  {                                                                   \
-	    while (1)                                                         \
-	      {                                                               \
-		portnum = (port_per_thread * snat_thread_index) +             \
-			  snat_random_port (0, port_per_thread - 1) + 1024;   \
-		if (a->busy_##n##_port_refcounts[portnum])                    \
-		  continue;                                                   \
-		--a->busy_##n##_port_refcounts[portnum];                      \
-		a->busy_##n##_ports_per_thread[thread_index]++;               \
-		a->busy_##n##_ports++;                                        \
-		*addr = a->addr;                                              \
-		*port = clib_host_to_net_u16 (portnum);                       \
-		return 0;                                                     \
-	      }                                                               \
-	  }                                                                   \
-	else if (a->fib_index == ~0)                                          \
-	  {                                                                   \
-	    ga = a;                                                           \
-	  }                                                                   \
-      }                                                                       \
-    break;
-	  foreach_nat_protocol
-#undef _
-	    default : nat_elog_info ("unknown protocol");
-	  return 1;
-	}
-    }
-
-  if (ga)
-    {
-      a = ga;
-      switch (proto)
-	{
-#define _(N, j, n, s)                                                         \
-  case NAT_PROTOCOL_##N:                                                      \
-    while (1)                                                                 \
-      {                                                                       \
-	portnum = (port_per_thread * snat_thread_index) +                     \
-		  snat_random_port (0, port_per_thread - 1) + 1024;           \
-	if (a->busy_##n##_port_refcounts[portnum])                            \
-	  continue;                                                           \
-	++a->busy_##n##_port_refcounts[portnum];                              \
-	a->busy_##n##_ports_per_thread[thread_index]++;                       \
-	a->busy_##n##_ports++;                                                \
-	*addr = a->addr;                                                      \
-	*port = clib_host_to_net_u16 (portnum);                               \
-	return 0;                                                             \
-      }
-	  break;
-	  foreach_nat_protocol
-#undef _
-	    default : nat_elog_info ("unknown protocol");
-	  return 1;
-	}
-    }
-
-  /* Totally out of translations to use... */
-  nat_ipfix_logging_addresses_exhausted (thread_index, 0);
-  return 1;
-}
-
-static snat_session_t *
-create_session_for_static_mapping_ed (
-  snat_main_t *sm, vlib_buffer_t *b, ip4_address_t i2o_addr, u16 i2o_port,
-  u32 i2o_fib_index, ip4_address_t o2i_addr, u16 o2i_port, u32 o2i_fib_index,
-  nat_protocol_t nat_proto, vlib_node_runtime_t *node, u32 rx_fib_index,
-  u32 thread_index, twice_nat_type_t twice_nat, lb_nat_type_t lb_nat, f64 now,
-  snat_static_mapping_t *mapping)
-{
-  snat_session_t *s;
-  ip4_header_t *ip;
-  udp_header_t *udp;
-  snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
-
-  if (PREDICT_FALSE
-      (nat44_ed_maximum_sessions_exceeded (sm, rx_fib_index, thread_index)))
-    {
-      b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
-      nat_elog_notice ("maximum sessions exceeded");
-      return 0;
-    }
-
-  s = nat_ed_session_alloc (sm, thread_index, now, nat_proto);
-  if (!s)
-    {
-      b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_USER_SESS_EXCEEDED];
-      nat_elog_warn ("create NAT session failed");
-      return 0;
-    }
-
-  ip = vlib_buffer_get_current (b);
-  udp = ip4_next_header (ip);
-
-  s->ext_host_addr.as_u32 = ip->src_address.as_u32;
-  s->ext_host_port = nat_proto == NAT_PROTOCOL_ICMP ? 0 : udp->src_port;
-  s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
-  if (lb_nat)
-    s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
-  if (lb_nat == AFFINITY_LB_NAT)
-    s->flags |= SNAT_SESSION_FLAG_AFFINITY;
-  s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
-  s->out2in.addr = o2i_addr;
-  s->out2in.port = o2i_port;
-  s->out2in.fib_index = o2i_fib_index;
-  s->in2out.addr = i2o_addr;
-  s->in2out.port = i2o_port;
-  s->in2out.fib_index = i2o_fib_index;
-  s->nat_proto = nat_proto;
-
-  if (NAT_PROTOCOL_ICMP == nat_proto)
-    {
-      nat_6t_o2i_flow_init (sm, thread_index, s, s->ext_host_addr, o2i_port,
-			    o2i_addr, o2i_port, o2i_fib_index, ip->protocol);
-      nat_6t_flow_icmp_id_rewrite_set (&s->o2i, i2o_port);
-    }
-  else
-    {
-      nat_6t_o2i_flow_init (sm, thread_index, s, s->ext_host_addr,
-			    s->ext_host_port, o2i_addr, o2i_port,
-			    o2i_fib_index, ip->protocol);
-      nat_6t_flow_dport_rewrite_set (&s->o2i, i2o_port);
-    }
-  nat_6t_flow_daddr_rewrite_set (&s->o2i, i2o_addr.as_u32);
-  nat_6t_flow_txfib_rewrite_set (&s->o2i, i2o_fib_index);
-
-  if (nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 1))
-    {
-      b->error = node->errors[NAT_OUT2IN_ED_ERROR_HASH_ADD_FAILED];
-      nat_ed_session_delete (sm, s, thread_index, 1);
-      nat_elog_warn ("out2in flow hash add failed");
-      return 0;
-    }
-
-  if (twice_nat == TWICE_NAT || (twice_nat == TWICE_NAT_SELF &&
-				 ip->src_address.as_u32 == i2o_addr.as_u32))
-    {
-      int rc = 0;
-      snat_address_t *filter = 0;
-
-      // if exact address is specified use this address
-      if (is_exact_address (mapping))
-	{
-	  snat_address_t *ap;
-	  vec_foreach (ap, sm->twice_nat_addresses)
-	  {
-	    if (mapping->pool_addr.as_u32 == ap->addr.as_u32)
-	      {
-		filter = ap;
-		break;
-	      }
-	  }
-	}
-
-      if (filter)
-	{
-	  rc = nat_alloc_addr_and_port_exact (filter,
-					      thread_index,
-					      nat_proto,
-					      &s->ext_host_nat_addr,
-					      &s->ext_host_nat_port,
-					      sm->port_per_thread,
-					      tsm->snat_thread_index);
-	  s->flags |= SNAT_SESSION_FLAG_EXACT_ADDRESS;
-	}
-      else
-	{
-	  rc = nat44_ed_alloc_outside_addr_and_port (
-	    sm->twice_nat_addresses, 0, thread_index, nat_proto,
-	    &s->ext_host_nat_addr, &s->ext_host_nat_port, sm->port_per_thread,
-	    tsm->snat_thread_index);
-	}
-
-      if (rc)
-	{
-	  b->error = node->errors[NAT_OUT2IN_ED_ERROR_OUT_OF_PORTS];
-	  if (nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 0))
-	    {
-	      nat_elog_warn ("out2in flow hash del failed");
-	    }
-	  snat_free_outside_address_and_port (
-	    sm->twice_nat_addresses, thread_index, &s->ext_host_nat_addr,
-	    s->ext_host_nat_port, s->nat_proto);
-	  nat_ed_session_delete (sm, s, thread_index, 1);
-	  return 0;
-	}
-
-      s->flags |= SNAT_SESSION_FLAG_TWICE_NAT;
-
-      nat_6t_flow_saddr_rewrite_set (&s->o2i, s->ext_host_nat_addr.as_u32);
-      if (NAT_PROTOCOL_ICMP == nat_proto)
-	{
-	  nat_6t_flow_icmp_id_rewrite_set (&s->o2i, s->ext_host_nat_port);
-	}
-      else
-	{
-	  nat_6t_flow_sport_rewrite_set (&s->o2i, s->ext_host_nat_port);
-	}
-
-      nat_6t_l3_l4_csum_calc (&s->o2i);
-
-      nat_6t_i2o_flow_init (sm, thread_index, s, i2o_addr, i2o_port,
-			    s->ext_host_nat_addr, s->ext_host_nat_port,
-			    i2o_fib_index, ip->protocol);
-      nat_6t_flow_daddr_rewrite_set (&s->i2o, s->ext_host_addr.as_u32);
-      if (NAT_PROTOCOL_ICMP == nat_proto)
-	{
-	  nat_6t_flow_icmp_id_rewrite_set (&s->i2o, s->ext_host_port);
-	}
-      else
-	{
-	  nat_6t_flow_dport_rewrite_set (&s->i2o, s->ext_host_port);
-	}
-    }
-  else
-    {
-      if (NAT_PROTOCOL_ICMP == nat_proto)
-	{
-	  nat_6t_i2o_flow_init (sm, thread_index, s, i2o_addr, i2o_port,
-				s->ext_host_addr, i2o_port, i2o_fib_index,
-				ip->protocol);
-	}
-      else
-	{
-	  nat_6t_i2o_flow_init (sm, thread_index, s, i2o_addr, i2o_port,
-				s->ext_host_addr, s->ext_host_port,
-				i2o_fib_index, ip->protocol);
-	}
-    }
-
-  nat_6t_flow_saddr_rewrite_set (&s->i2o, o2i_addr.as_u32);
-  if (NAT_PROTOCOL_ICMP == nat_proto)
-    {
-      nat_6t_flow_icmp_id_rewrite_set (&s->i2o, o2i_port);
-    }
-  else
-    {
-      nat_6t_flow_sport_rewrite_set (&s->i2o, o2i_port);
-    }
-
-  if (nat_ed_ses_i2o_flow_hash_add_del (sm, thread_index, s, 1))
-    {
-      nat_elog_notice ("in2out flow hash add failed");
-      if (nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 0))
-	{
-	  nat_elog_warn ("out2in flow hash del failed");
-	}
-      nat_ed_session_delete (sm, s, thread_index, 1);
-      return 0;
-    }
-
-  nat_ipfix_logging_nat44_ses_create (thread_index,
-				      s->in2out.addr.as_u32,
-				      s->out2in.addr.as_u32,
-				      s->nat_proto,
-				      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->nat_proto, is_twice_nat_session (s));
-
-  per_vrf_sessions_register_session (s, thread_index);
-
-  return s;
-}
-
-static void
-create_bypass_for_fwd (snat_main_t *sm, vlib_buffer_t *b, snat_session_t *s,
-		       ip4_header_t *ip, u32 rx_fib_index, u32 thread_index)
-{
-  clib_bihash_kv_16_8_t kv, value;
-  udp_header_t *udp;
-  snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
-  vlib_main_t *vm = vlib_get_main ();
-  f64 now = vlib_time_now (vm);
-  u16 lookup_sport, lookup_dport;
-  u8 lookup_protocol;
-  ip4_address_t lookup_saddr, lookup_daddr;
-
-  if (ip->protocol == IP_PROTOCOL_ICMP)
-    {
-      if (nat_get_icmp_session_lookup_values (b, ip, &lookup_saddr,
-					      &lookup_sport, &lookup_daddr,
-					      &lookup_dport, &lookup_protocol))
-	return;
-    }
-  else
-    {
-      if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
-	{
-	  udp = ip4_next_header (ip);
-	  lookup_sport = udp->dst_port;
-	  lookup_dport = udp->src_port;
-	}
-      else
-	{
-	  lookup_sport = 0;
-	  lookup_dport = 0;
-	}
-      lookup_saddr.as_u32 = ip->dst_address.as_u32;
-      lookup_daddr.as_u32 = ip->src_address.as_u32;
-      lookup_protocol = ip->protocol;
-    }
-
-  init_ed_k (&kv, lookup_saddr, lookup_sport, lookup_daddr, lookup_dport,
-	     rx_fib_index, lookup_protocol);
-
-  if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv, &value))
-    {
-      ASSERT (thread_index == ed_value_get_thread_index (&value));
-      s =
-	pool_elt_at_index (tsm->sessions,
-			   ed_value_get_session_index (&value));
-    }
-  else if (ip->protocol == IP_PROTOCOL_ICMP &&
-	   icmp_type_is_error_message
-	   (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags))
-    {
-      return;
-    }
-  else
-    {
-      u32 proto;
-
-      if (PREDICT_FALSE
-	  (nat44_ed_maximum_sessions_exceeded
-	   (sm, rx_fib_index, thread_index)))
-	return;
-
-      s = nat_ed_session_alloc (sm, thread_index, now, ip->protocol);
-      if (!s)
-	{
-	  nat_elog_warn ("create NAT session failed");
-	  return;
-	}
-
-      proto = ip_proto_to_nat_proto (ip->protocol);
-
-      s->ext_host_addr = ip->src_address;
-      s->ext_host_port = lookup_dport;
-      s->flags |= SNAT_SESSION_FLAG_FWD_BYPASS;
-      s->out2in.addr = ip->dst_address;
-      s->out2in.port = lookup_sport;
-      s->nat_proto = proto;
-      if (proto == NAT_PROTOCOL_OTHER)
-	{
-	  s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
-	  s->out2in.port = ip->protocol;
-	}
-      s->out2in.fib_index = rx_fib_index;
-      s->in2out.addr = s->out2in.addr;
-      s->in2out.port = s->out2in.port;
-      s->in2out.fib_index = s->out2in.fib_index;
-
-      nat_6t_i2o_flow_init (sm, thread_index, s, ip->dst_address, lookup_sport,
-			    ip->src_address, lookup_dport, rx_fib_index,
-			    ip->protocol);
-      nat_6t_flow_txfib_rewrite_set (&s->i2o, rx_fib_index);
-      if (nat_ed_ses_i2o_flow_hash_add_del (sm, thread_index, s, 1))
-	{
-	  nat_elog_notice ("in2out flow add failed");
-	  nat_ed_session_delete (sm, s, thread_index, 1);
-	  return;
-	}
-
-      per_vrf_sessions_register_session (s, thread_index);
-    }
-
-  if (ip->protocol == IP_PROTOCOL_TCP)
-    {
-      tcp_header_t *tcp = ip4_next_header (ip);
-      nat44_set_tcp_session_state_o2i (sm, now, s, tcp->flags,
-				       tcp->ack_number, tcp->seq_number,
-				       thread_index);
-    }
-
-  /* Accounting */
-  nat44_session_update_counters (s, now, 0, thread_index);
-  /* Per-user LRU list maintenance */
-  nat44_session_update_lru (sm, s, thread_index);
-}
-
-static snat_session_t *
-nat44_ed_out2in_slowpath_unknown_proto (snat_main_t *sm, vlib_buffer_t *b,
-					ip4_header_t *ip, u32 rx_fib_index,
-					u32 thread_index, f64 now,
-					vlib_main_t *vm,
-					vlib_node_runtime_t *node)
-{
-  clib_bihash_kv_8_8_t kv, value;
-  snat_static_mapping_t *m;
-  snat_session_t *s;
-
-  if (PREDICT_FALSE (
-	nat44_ed_maximum_sessions_exceeded (sm, rx_fib_index, thread_index)))
-    {
-      b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
-      nat_elog_notice ("maximum sessions exceeded");
-      return 0;
-    }
-
-  init_nat_k (&kv, ip->dst_address, 0, 0, 0);
-  if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
-    {
-      b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
-      return 0;
-    }
-
-  m = pool_elt_at_index (sm->static_mappings, value.value);
-
-  /* Create a new session */
-  s = nat_ed_session_alloc (sm, thread_index, now, ip->protocol);
-  if (!s)
-    {
-      b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_USER_SESS_EXCEEDED];
-      nat_elog_warn ("create NAT session failed");
-      return 0;
-    }
-
-  s->ext_host_addr.as_u32 = ip->src_address.as_u32;
-  s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
-  s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
-  s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
-  s->out2in.addr.as_u32 = ip->dst_address.as_u32;
-  s->out2in.fib_index = rx_fib_index;
-  s->in2out.addr.as_u32 = m->local_addr.as_u32;
-  s->in2out.fib_index = m->fib_index;
-  s->in2out.port = s->out2in.port = ip->protocol;
-
-  nat_6t_o2i_flow_init (sm, thread_index, s, ip->dst_address, 0,
-			ip->src_address, 0, m->fib_index, ip->protocol);
-  nat_6t_flow_saddr_rewrite_set (&s->i2o, ip->dst_address.as_u32);
-  if (nat_ed_ses_i2o_flow_hash_add_del (sm, thread_index, s, 1))
-    {
-      nat_elog_notice ("in2out key add failed");
-      nat_ed_session_delete (sm, s, thread_index, 1);
-      return NULL;
-    }
-
-  nat_6t_o2i_flow_init (sm, thread_index, s, ip->src_address, 0,
-			ip->dst_address, 0, rx_fib_index, ip->protocol);
-  nat_6t_flow_daddr_rewrite_set (&s->o2i, m->local_addr.as_u32);
-  nat_6t_flow_txfib_rewrite_set (&s->o2i, m->fib_index);
-  if (nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 1))
-    {
-      nat_elog_notice ("out2in flow hash add failed");
-      nat_ed_session_delete (sm, s, thread_index, 1);
-      return NULL;
-    }
-
-  per_vrf_sessions_register_session (s, thread_index);
-
-  /* Accounting */
-  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);
-
-  return s;
-}
-
-static inline uword
-nat44_ed_out2in_fast_path_node_fn_inline (vlib_main_t * vm,
-					  vlib_node_runtime_t * node,
-					  vlib_frame_t * frame,
-					  int is_multi_worker)
-{
-  u32 n_left_from, *from;
-  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];
-
-  from = vlib_frame_vector_args (frame);
-  n_left_from = frame->n_vectors;
-
-  vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
-  u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
-  vlib_get_buffers (vm, from, b, n_left_from);
-
-  while (n_left_from > 0)
-    {
-      vlib_buffer_t *b0;
-      u32 sw_if_index0, rx_fib_index0;
-      nat_protocol_t proto0;
-      ip4_header_t *ip0;
-      snat_session_t *s0 = 0;
-      clib_bihash_kv_16_8_t kv0, value0;
-      nat_translation_error_e translation_error = NAT_ED_TRNSL_ERR_SUCCESS;
-      nat_6t_flow_t *f = 0;
-      ip4_address_t lookup_saddr, lookup_daddr;
-      u16 lookup_sport, lookup_dport;
-      u8 lookup_protocol;
-      int lookup_skipped = 0;
-
-      b0 = *b;
-      b++;
-
-      lookup_sport = vnet_buffer (b0)->ip.reass.l4_src_port;
-      lookup_dport = vnet_buffer (b0)->ip.reass.l4_dst_port;
-
-      /* Prefetch next iteration. */
-      if (PREDICT_TRUE (n_left_from >= 2))
-	{
-	  vlib_buffer_t *p2;
-
-	  p2 = *b;
-
-	  vlib_prefetch_buffer_header (p2, LOAD);
-
-	  CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, LOAD);
-	}
-
-      next[0] = vnet_buffer2 (b0)->nat.arc_next;
-
-      vnet_buffer (b0)->snat.flags = 0;
-      ip0 = vlib_buffer_get_current (b0);
-
-      sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
-      rx_fib_index0 =
-	fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4, sw_if_index0);
-
-      if (PREDICT_FALSE (ip0->ttl == 1))
-	{
-	  vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
-	  icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
-				       ICMP4_time_exceeded_ttl_exceeded_in_transit,
-				       0);
-	  next[0] = NAT_NEXT_ICMP_ERROR;
-	  goto trace0;
-	}
-
-      proto0 = ip_proto_to_nat_proto (ip0->protocol);
-
-      if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
-	{
-	  if (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
-		ICMP4_echo_request &&
-	      vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
-		ICMP4_echo_reply &&
-	      !icmp_type_is_error_message (
-		vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags))
-	    {
-	      b0->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
-	      next[0] = NAT_NEXT_DROP;
-	      goto trace0;
-	    }
-	  int err = nat_get_icmp_session_lookup_values (
-	    b0, ip0, &lookup_saddr, &lookup_sport, &lookup_daddr,
-	    &lookup_dport, &lookup_protocol);
-	  if (err != 0)
-	    {
-	      b0->error = node->errors[err];
-	      next[0] = NAT_NEXT_DROP;
-	      goto trace0;
-	    }
-	}
-      else
-	{
-	  lookup_saddr.as_u32 = ip0->src_address.as_u32;
-	  lookup_daddr.as_u32 = ip0->dst_address.as_u32;
-	  lookup_protocol = ip0->protocol;
-	}
-
-      /* there might be a stashed index in vnet_buffer2 from handoff or
-       * classify node, see if it can be used */
-      if (!pool_is_free_index (tsm->sessions,
-			       vnet_buffer2 (b0)->nat.cached_session_index))
-	{
-	  s0 = pool_elt_at_index (tsm->sessions,
-				  vnet_buffer2 (b0)->nat.cached_session_index);
-	  if (PREDICT_TRUE (
-		nat_6t_flow_match (&s0->o2i, b0, lookup_saddr, lookup_sport,
-				   lookup_daddr, lookup_dport, lookup_protocol,
-				   rx_fib_index0) ||
-		(s0->flags & SNAT_SESSION_FLAG_TWICE_NAT &&
-		 nat_6t_flow_match (&s0->i2o, b0, lookup_saddr, lookup_sport,
-				    lookup_daddr, lookup_dport,
-				    lookup_protocol, rx_fib_index0))))
-	    {
-	      /* yes, this is the droid we're looking for */
-	      lookup_skipped = 1;
-	      goto skip_lookup;
-	    }
-	  s0 = NULL;
-	}
-
-      init_ed_k (&kv0, lookup_saddr, lookup_sport, lookup_daddr, lookup_dport,
-		 rx_fib_index0, lookup_protocol);
-
-      // lookup flow
-      if (clib_bihash_search_16_8 (&sm->flow_hash, &kv0, &value0))
-	{
-	  // flow does not exist go slow path
-	  next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
-	  goto trace0;
-	}
-      ASSERT (thread_index == ed_value_get_thread_index (&value0));
-      s0 =
-	pool_elt_at_index (tsm->sessions,
-			   ed_value_get_session_index (&value0));
-    skip_lookup:
-
-      if (PREDICT_FALSE (per_vrf_sessions_is_expired (s0, thread_index)))
-	{
-	  // session is closed, go slow path
-	  nat_free_session_data (sm, s0, thread_index, 0);
-	  nat_ed_session_delete (sm, s0, thread_index, 1);
-	  next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
-	  goto trace0;
-	}
-
-      if (s0->tcp_closed_timestamp)
-	{
-	  if (now >= s0->tcp_closed_timestamp)
-	    {
-	      // session is closed, go slow path, freed in slow path
-	      next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
-	    }
-	  else
-	    {
-	      // session in transitory timeout, drop
-	      b0->error = node->errors[NAT_OUT2IN_ED_ERROR_TCP_CLOSED];
-	      next[0] = NAT_NEXT_DROP;
-	    }
-	  goto trace0;
-	}
-
-      // drop if session expired
-      u64 sess_timeout_time;
-      sess_timeout_time =
-	s0->last_heard + (f64) nat44_session_get_timeout (sm, s0);
-      if (now >= sess_timeout_time)
-	{
-	  // session is closed, go slow path
-	  nat_free_session_data (sm, s0, thread_index, 0);
-	  nat_ed_session_delete (sm, s0, thread_index, 1);
-	  next[0] = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
-	  goto trace0;
-	}
-
-      if (nat_6t_flow_match (&s0->o2i, b0, lookup_saddr, lookup_sport,
-			     lookup_daddr, lookup_dport, lookup_protocol,
-			     rx_fib_index0))
-	{
-	  f = &s0->o2i;
-	}
-      else if (s0->flags & SNAT_SESSION_FLAG_TWICE_NAT &&
-	       nat_6t_flow_match (&s0->i2o, b0, lookup_saddr, lookup_sport,
-				  lookup_daddr, lookup_dport, lookup_protocol,
-				  rx_fib_index0))
-	{
-	  f = &s0->i2o;
-	}
-      else
-	{
-	  /*
-	   * Send DHCP packets to the ipv4 stack, or we won't
-	   * be able to use dhcp client on the outside interface
-	   */
-	  if (PREDICT_FALSE (
-		proto0 == NAT_PROTOCOL_UDP &&
-		(vnet_buffer (b0)->ip.reass.l4_dst_port ==
-		 clib_host_to_net_u16 (UDP_DST_PORT_dhcp_to_client))))
-	    {
-	      goto trace0;
-	    }
-
-	  if (!sm->forwarding_enabled)
-	    {
-	      b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
-	      next[0] = NAT_NEXT_DROP;
-	      goto trace0;
-	    }
-	  else
-	    {
-	      if (nat_6t_flow_match (&s0->i2o, b0, lookup_saddr, lookup_sport,
-				     lookup_daddr, lookup_dport,
-				     lookup_protocol, rx_fib_index0))
-		{
-		  f = &s0->i2o;
-		}
-	      else
-		{
-		  // FIXME TODO bypass ???
-		  //  create_bypass_for_fwd (sm, b0, s0, ip0, rx_fib_index0,
-		  //                       thread_index);
-		  translation_error = NAT_ED_TRNSL_ERR_FLOW_MISMATCH;
-		  nat_free_session_data (sm, s0, thread_index, 0);
-		  nat_ed_session_delete (sm, s0, thread_index, 1);
-		  next[0] = NAT_NEXT_DROP;
-		  goto trace0;
-		}
-	    }
-	}
-
-      if (NAT_ED_TRNSL_ERR_SUCCESS !=
-	  (translation_error = nat_6t_flow_buf_translate (
-	     sm, b0, ip0, f, proto0, 0 /* is_output_feature */)))
-	{
-	  next[0] = NAT_NEXT_DROP;
-	  goto trace0;
-	}
-
-      switch (proto0)
-	{
-	case NAT_PROTOCOL_TCP:
-	  vlib_increment_simple_counter (&sm->counters.fastpath.out2in_ed.tcp,
-					 thread_index, sw_if_index0, 1);
-	  nat44_set_tcp_session_state_o2i (sm, now, s0,
-					   vnet_buffer (b0)->ip.
-					   reass.icmp_type_or_tcp_flags,
-					   vnet_buffer (b0)->ip.
-					   reass.tcp_ack_number,
-					   vnet_buffer (b0)->ip.
-					   reass.tcp_seq_number,
-					   thread_index);
-	  break;
-	case NAT_PROTOCOL_UDP:
-	  vlib_increment_simple_counter (&sm->counters.fastpath.out2in_ed.udp,
-					 thread_index, sw_if_index0, 1);
-	  break;
-	case NAT_PROTOCOL_ICMP:
-	  vlib_increment_simple_counter (&sm->counters.fastpath.out2in_ed.icmp,
-					 thread_index, sw_if_index0, 1);
-	  break;
-	case NAT_PROTOCOL_OTHER:
-	  vlib_increment_simple_counter (
-	    &sm->counters.fastpath.out2in_ed.other, thread_index, sw_if_index0,
-	    1);
-	  break;
-	}
-
-      /* Accounting */
-      nat44_session_update_counters (s0, now,
-				     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)
-			 && (b0->flags & VLIB_BUFFER_IS_TRACED)))
-	{
-	  nat44_ed_out2in_trace_t *t =
-	    vlib_add_trace (vm, node, b0, sizeof (*t));
-	  t->sw_if_index = sw_if_index0;
-	  t->next_index = next[0];
-	  t->is_slow_path = 0;
-	  t->translation_error = translation_error;
-	  clib_memcpy (&t->search_key, &kv0, sizeof (t->search_key));
-	  t->lookup_skipped = lookup_skipped;
-
-	  if (s0)
-	    {
-	      t->session_index = s0 - tsm->sessions;
-	      clib_memcpy (&t->i2of, &s0->i2o, sizeof (t->i2of));
-	      clib_memcpy (&t->o2if, &s0->o2i, sizeof (t->o2if));
-	      t->translation_via_i2of = (&s0->i2o == f);
-	    }
-	  else
-	    {
-	      t->session_index = ~0;
-	    }
-	}
-
-      if (next[0] == NAT_NEXT_DROP)
-	{
-	  vlib_increment_simple_counter (&sm->counters.fastpath.
-					 out2in_ed.drops, thread_index,
-					 sw_if_index0, 1);
-	}
-
-      n_left_from--;
-      next++;
-    }
-
-  vlib_buffer_enqueue_to_next (vm, node, from, (u16 *) nexts,
-			       frame->n_vectors);
-  return frame->n_vectors;
-}
-
-static inline uword
-nat44_ed_out2in_slow_path_node_fn_inline (vlib_main_t * vm,
-					  vlib_node_runtime_t * node,
-					  vlib_frame_t * frame)
-{
-  u32 n_left_from, *from;
-  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];
-  snat_static_mapping_t *m;
-
-  from = vlib_frame_vector_args (frame);
-  n_left_from = frame->n_vectors;
-
-  vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
-  u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
-  vlib_get_buffers (vm, from, b, n_left_from);
-
-  while (n_left_from > 0)
-    {
-      vlib_buffer_t *b0;
-      u32 sw_if_index0, rx_fib_index0;
-      nat_protocol_t proto0;
-      ip4_header_t *ip0;
-      udp_header_t *udp0;
-      icmp46_header_t *icmp0;
-      snat_session_t *s0 = 0;
-      clib_bihash_kv_16_8_t kv0, value0;
-      lb_nat_type_t lb_nat0;
-      twice_nat_type_t twice_nat0;
-      u8 identity_nat0;
-      ip4_address_t sm_addr;
-      u16 sm_port;
-      u32 sm_fib_index;
-      nat_translation_error_e translation_error = NAT_ED_TRNSL_ERR_SUCCESS;
-
-      b0 = *b;
-      next[0] = vnet_buffer2 (b0)->nat.arc_next;
-
-      vnet_buffer (b0)->snat.flags = 0;
-      ip0 = vlib_buffer_get_current (b0);
-
-      sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
-      rx_fib_index0 =
-	fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4, sw_if_index0);
-
-      if (PREDICT_FALSE (ip0->ttl == 1))
-	{
-	  vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
-	  icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
-				       ICMP4_time_exceeded_ttl_exceeded_in_transit,
-				       0);
-	  next[0] = NAT_NEXT_ICMP_ERROR;
-	  goto trace0;
-	}
-
-      udp0 = ip4_next_header (ip0);
-      icmp0 = (icmp46_header_t *) udp0;
-      proto0 = ip_proto_to_nat_proto (ip0->protocol);
-
-      if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
-	{
-	  s0 = nat44_ed_out2in_slowpath_unknown_proto (
-	    sm, b0, ip0, rx_fib_index0, thread_index, now, vm, node);
-	  if (!sm->forwarding_enabled)
-	    {
-	      if (!s0)
-		next[0] = NAT_NEXT_DROP;
-	    }
-	  if (NAT_NEXT_DROP != next[0] &&
-	      NAT_ED_TRNSL_ERR_SUCCESS !=
-		(translation_error = nat_6t_flow_buf_translate (
-		   sm, b0, ip0, &s0->o2i, proto0, 0 /* is_output_feature */)))
-	    {
-	      goto trace0;
-	    }
-
-	  vlib_increment_simple_counter (&sm->counters.slowpath.
-					 out2in_ed.other, thread_index,
-					 sw_if_index0, 1);
-	  goto trace0;
-	}
-
-      if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
-	{
-	  next[0] = icmp_out2in_ed_slow_path
-	    (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
-	     next[0], now, thread_index, &s0);
-
-	  if (NAT_NEXT_DROP != next[0] && s0 &&
-	      NAT_ED_TRNSL_ERR_SUCCESS !=
-		(translation_error = nat_6t_flow_buf_translate (
-		   sm, b0, ip0, &s0->o2i, proto0, 0 /* is_output_feature */)))
-	    {
-	      goto trace0;
-	    }
-
-	  vlib_increment_simple_counter (&sm->counters.slowpath.
-					 out2in_ed.icmp, thread_index,
-					 sw_if_index0, 1);
-	  goto trace0;
-	}
-
-      init_ed_k (&kv0, ip0->src_address,
-		 vnet_buffer (b0)->ip.reass.l4_src_port, ip0->dst_address,
-		 vnet_buffer (b0)->ip.reass.l4_dst_port, rx_fib_index0,
-		 ip0->protocol);
-
-      s0 = NULL;
-      if (!clib_bihash_search_16_8 (&sm->flow_hash, &kv0, &value0))
-	{
-	  ASSERT (thread_index == ed_value_get_thread_index (&value0));
-	  s0 =
-	    pool_elt_at_index (tsm->sessions,
-			       ed_value_get_session_index (&value0));
-
-	  if (s0->tcp_closed_timestamp && now >= s0->tcp_closed_timestamp)
-	    {
-	      nat_free_session_data (sm, s0, thread_index, 0);
-	      nat_ed_session_delete (sm, s0, thread_index, 1);
-	      s0 = NULL;
-	    }
-	}
-
-      if (!s0)
-	{
-	  /* Try to match static mapping by external address and port,
-	     destination address and port in packet */
-
-	  if (snat_static_mapping_match
-	      (sm, ip0->dst_address,
-	       vnet_buffer (b0)->ip.reass.l4_dst_port, rx_fib_index0,
-	       proto0, &sm_addr, &sm_port, &sm_fib_index, 1, 0,
-	       &twice_nat0, &lb_nat0, &ip0->src_address, &identity_nat0, &m))
-	    {
-	      /*
-	       * Send DHCP packets to the ipv4 stack, or we won't
-	       * be able to use dhcp client on the outside interface
-	       */
-	      if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_UDP
-				 && (vnet_buffer (b0)->ip.reass.l4_dst_port ==
-				     clib_host_to_net_u16
-				     (UDP_DST_PORT_dhcp_to_client))))
-		{
-		  goto trace0;
-		}
-
-	      if (!sm->forwarding_enabled)
-		{
-		  b0->error =
-		    node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
-		  next[0] = NAT_NEXT_DROP;
-		}
-	      else
-		{
-		  if (next_src_nat
-		      (sm, ip0, vnet_buffer (b0)->ip.reass.l4_src_port,
-		       vnet_buffer (b0)->ip.reass.l4_dst_port,
-		       thread_index, rx_fib_index0))
-		    {
-		      next[0] = NAT_NEXT_IN2OUT_ED_FAST_PATH;
-		    }
-		  else
-		    {
-		      create_bypass_for_fwd (sm, b0, s0, ip0, rx_fib_index0,
-					     thread_index);
-		    }
-		}
-	      goto trace0;
-	    }
-
-	  if (PREDICT_FALSE (identity_nat0))
-	    goto trace0;
-
-	  if ((proto0 == NAT_PROTOCOL_TCP)
-	      && !tcp_flags_is_init (vnet_buffer (b0)->ip.
-				     reass.icmp_type_or_tcp_flags))
-	    {
-	      b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
-	      next[0] = NAT_NEXT_DROP;
-	      goto trace0;
-	    }
-
-	  /* Create session initiated by host from external network */
-	  s0 = create_session_for_static_mapping_ed (sm, b0,
-						     sm_addr, sm_port,
-						     sm_fib_index,
-						     ip0->dst_address,
-						     vnet_buffer (b0)->
-						     ip.reass.l4_dst_port,
-						     rx_fib_index0, proto0,
-						     node, rx_fib_index0,
-						     thread_index, twice_nat0,
-						     lb_nat0, now, m);
-	  if (!s0)
-	    {
-	      next[0] = NAT_NEXT_DROP;
-	      goto trace0;
-	    }
-	}
-
-      if (NAT_ED_TRNSL_ERR_SUCCESS !=
-	  (translation_error = nat_6t_flow_buf_translate (
-	     sm, b0, ip0, &s0->o2i, proto0, 0 /* is_output_feature */)))
-	{
-	  next[0] = NAT_NEXT_DROP;
-	  goto trace0;
-	}
-
-      if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
-	{
-	  vlib_increment_simple_counter (&sm->counters.slowpath.out2in_ed.tcp,
-					 thread_index, sw_if_index0, 1);
-	  nat44_set_tcp_session_state_o2i (sm, now, s0,
-					   vnet_buffer (b0)->ip.
-					   reass.icmp_type_or_tcp_flags,
-					   vnet_buffer (b0)->ip.
-					   reass.tcp_ack_number,
-					   vnet_buffer (b0)->ip.
-					   reass.tcp_seq_number,
-					   thread_index);
-	}
-      else
-	{
-	  vlib_increment_simple_counter (&sm->counters.slowpath.out2in_ed.udp,
-					 thread_index, sw_if_index0, 1);
-	}
-
-      /* Accounting */
-      nat44_session_update_counters (s0, now,
-				     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)
-			 && (b0->flags & VLIB_BUFFER_IS_TRACED)))
-	{
-	  nat44_ed_out2in_trace_t *t =
-	    vlib_add_trace (vm, node, b0, sizeof (*t));
-	  t->sw_if_index = sw_if_index0;
-	  t->next_index = next[0];
-	  t->is_slow_path = 1;
-	  t->translation_error = translation_error;
-	  clib_memcpy (&t->search_key, &kv0, sizeof (t->search_key));
-
-	  if (s0)
-	    {
-	      t->session_index = s0 - tsm->sessions;
-	      clib_memcpy (&t->i2of, &s0->i2o, sizeof (t->i2of));
-	      clib_memcpy (&t->o2if, &s0->o2i, sizeof (t->o2if));
-	    }
-	  else
-	    {
-	      t->session_index = ~0;
-	    }
-	}
-
-      if (next[0] == NAT_NEXT_DROP)
-	{
-	  vlib_increment_simple_counter (&sm->counters.slowpath.
-					 out2in_ed.drops, thread_index,
-					 sw_if_index0, 1);
-	}
-
-      n_left_from--;
-      next++;
-      b++;
-    }
-
-  vlib_buffer_enqueue_to_next (vm, node, from, (u16 *) nexts,
-			       frame->n_vectors);
-
-  return frame->n_vectors;
-}
-
-VLIB_NODE_FN (nat44_ed_out2in_node) (vlib_main_t * vm,
-				     vlib_node_runtime_t * node,
-				     vlib_frame_t * frame)
-{
-  if (snat_main.num_workers > 1)
-    {
-      return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame, 1);
-    }
-  else
-    {
-      return nat44_ed_out2in_fast_path_node_fn_inline (vm, node, frame, 0);
-    }
-}
-
-/* *INDENT-OFF* */
-VLIB_REGISTER_NODE (nat44_ed_out2in_node) = {
-  .name = "nat44-ed-out2in",
-  .vector_size = sizeof (u32),
-  .sibling_of = "nat-default",
-  .format_trace = format_nat44_ed_out2in_trace,
-  .type = VLIB_NODE_TYPE_INTERNAL,
-  .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
-  .error_strings = nat_out2in_ed_error_strings,
-  .runtime_data_bytes = sizeof (snat_runtime_t),
-};
-/* *INDENT-ON* */
-
-VLIB_NODE_FN (nat44_ed_out2in_slowpath_node) (vlib_main_t * vm,
-					      vlib_node_runtime_t * node,
-					      vlib_frame_t * frame)
-{
-  return nat44_ed_out2in_slow_path_node_fn_inline (vm, node, frame);
-}
-
-/* *INDENT-OFF* */
-VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = {
-  .name = "nat44-ed-out2in-slowpath",
-  .vector_size = sizeof (u32),
-  .sibling_of = "nat-default",
-  .format_trace = format_nat44_ed_out2in_trace,
-  .type = VLIB_NODE_TYPE_INTERNAL,
-  .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
-  .error_strings = nat_out2in_ed_error_strings,
-  .runtime_data_bytes = sizeof (snat_runtime_t),
-};
-/* *INDENT-ON* */
-
-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, "out2in next_index %d arc_next_index %d", t->next_index,
-		 t->arc_next_index);
-}
-
-VLIB_NODE_FN (nat_pre_out2in_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_OUT2IN_ED_FAST_PATH);
-}
-
-/* *INDENT-OFF* */
-VLIB_REGISTER_NODE (nat_pre_out2in_node) = {
-  .name = "nat-pre-out2in",
-  .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
- *
- * Local Variables:
- * eval: (c-set-style "gnu")
- * End:
- */