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, 1531 deletions

diff --git a/src/plugins/nat/in2out_ed.c b/src/plugins/nat/in2out_ed.c
deleted file mode 100644
index 9dc68576fd4..00000000000
--- a/src/plugins/nat/in2out_ed.c
+++ /dev/null
@@ -1,1531 +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 inside to outside 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>
-#include <nat/lib/nat_inlines.h>
-
-/* number of attempts to get a port for ED overloading algorithm, if rolling
- * a dice this many times doesn't produce a free port, it's treated
- * as if there were no free ports available to conserve resources */
-#define ED_PORT_ALLOC_ATTEMPTS (10)
-
-static char *nat_in2out_ed_error_strings[] = {
-#define _(sym,string) string,
-  foreach_nat_in2out_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;
-} nat_in2out_ed_trace_t;
-
-static u8 *
-format_nat_in2out_ed_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_in2out_ed_trace_t *t = va_arg (*args, nat_in2out_ed_trace_t *);
-  char *tag;
-
-  tag =
-    t->is_slow_path ? "NAT44_IN2OUT_ED_SLOW_PATH" :
-    "NAT44_IN2OUT_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
-nat_ed_alloc_addr_and_port (snat_main_t *sm, u32 rx_fib_index, u32 nat_proto,
-			    u32 thread_index, ip4_address_t r_addr, u16 r_port,
-			    u8 proto, u16 port_per_thread,
-			    u32 snat_thread_index, snat_session_t *s,
-			    ip4_address_t *outside_addr, u16 *outside_port)
-{
-  int i;
-  snat_address_t *a, *ga = 0;
-
-  const u16 port_thread_offset = (port_per_thread * snat_thread_index) + 1024;
-
-  for (i = 0; i < vec_len (sm->addresses); i++)
-    {
-      a = sm->addresses + i;
-      switch (nat_proto)
-	{
-#define _(N, j, n, unused)                                                    \
-  case NAT_PROTOCOL_##N:                                                      \
-    if (a->fib_index == rx_fib_index)                                         \
-      {                                                                       \
-	s->o2i.match.daddr = a->addr;                                         \
-	/* first try port suggested by caller */                              \
-	u16 port = clib_net_to_host_u16 (*outside_port);                      \
-	u16 port_offset = port - port_thread_offset;                          \
-	if (port <= port_thread_offset ||                                     \
-	    port > port_thread_offset + port_per_thread)                      \
-	  {                                                                   \
-	    /* need to pick a different port, suggested port doesn't fit in   \
-	     * this thread's port range */                                    \
-	    port_offset = snat_random_port (0, port_per_thread - 1);          \
-	    port = port_thread_offset + port_offset;                          \
-	  }                                                                   \
-	u16 attempts = ED_PORT_ALLOC_ATTEMPTS;                                \
-	do                                                                    \
-	  {                                                                   \
-	    if (NAT_PROTOCOL_ICMP == nat_proto)                               \
-	      {                                                               \
-		s->o2i.match.sport = clib_host_to_net_u16 (port);             \
-	      }                                                               \
-	    s->o2i.match.dport = clib_host_to_net_u16 (port);                 \
-	    if (0 ==                                                          \
-		nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 2))    \
-	      {                                                               \
-		++a->busy_##n##_port_refcounts[port];                         \
-		a->busy_##n##_ports_per_thread[thread_index]++;               \
-		a->busy_##n##_ports++;                                        \
-		*outside_addr = a->addr;                                      \
-		*outside_port = clib_host_to_net_u16 (port);                  \
-		return 0;                                                     \
-	      }                                                               \
-	    port_offset = snat_random_port (0, port_per_thread - 1);          \
-	    port = port_thread_offset + port_offset;                          \
-	    --attempts;                                                       \
-	  }                                                                   \
-	while (attempts > 0);                                                 \
-      }                                                                       \
-    else if (a->fib_index == ~0)                                              \
-      {                                                                       \
-	ga = a;                                                               \
-      }                                                                       \
-    break;
-
-	  foreach_nat_protocol;
-	default:
-	  nat_elog_info ("unknown protocol");
-	  return 1;
-	}
-    }
-
-  if (ga)
-    {
-      /* fake fib_index to reuse macro */
-      rx_fib_index = ~0;
-      a = ga;
-      switch (nat_proto)
-	{
-	  foreach_nat_protocol;
-	default:
-	  nat_elog_info ("unknown protocol");
-	  return 1;
-	}
-    }
-
-#undef _
-
-  /* Totally out of translations to use... */
-  nat_ipfix_logging_addresses_exhausted (thread_index, 0);
-  return 1;
-}
-
-static_always_inline u32
-nat_outside_fib_index_lookup (snat_main_t * sm, ip4_address_t addr)
-{
-  fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
-  nat_outside_fib_t *outside_fib;
-  fib_prefix_t pfx = {
-    .fp_proto = FIB_PROTOCOL_IP4,
-    .fp_len = 32,
-    .fp_addr = {.ip4.as_u32 = addr.as_u32,}
-    ,
-  };
-  // TODO: multiple vrfs none can resolve addr
-  /* *INDENT-OFF* */
-  vec_foreach (outside_fib, sm->outside_fibs)
-    {
-      fei = fib_table_lookup (outside_fib->fib_index, &pfx);
-      if (FIB_NODE_INDEX_INVALID != fei)
-        {
-          if (fib_entry_get_resolving_interface (fei) != ~0)
-            {
-              return outside_fib->fib_index;
-            }
-        }
-    }
-  /* *INDENT-ON* */
-  return ~0;
-}
-
-static_always_inline int
-nat44_ed_external_sm_lookup (snat_main_t *sm, ip4_address_t match_addr,
-			     u16 match_port, nat_protocol_t match_protocol,
-			     u32 match_fib_index, ip4_address_t *daddr,
-			     u16 *dport)
-{
-  clib_bihash_kv_8_8_t kv, value;
-  init_nat_k (&kv, match_addr, match_port, match_fib_index, match_protocol);
-  if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
-    {
-      /* Try address only mapping */
-      init_nat_k (&kv, match_addr, 0, 0, 0);
-      if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv,
-				  &value))
-	return 0;
-    }
-
-  snat_static_mapping_t *m =
-    pool_elt_at_index (sm->static_mappings, value.value);
-  *daddr = m->local_addr;
-  if (dport)
-    {
-      /* Address only mapping doesn't change port */
-      *dport = is_addr_only_static_mapping (m) ? match_port : m->local_port;
-    }
-  return 1;
-}
-
-static u32
-slow_path_ed (snat_main_t *sm, vlib_buffer_t *b, ip4_address_t l_addr,
-	      ip4_address_t r_addr, u16 l_port, u16 r_port, u8 proto,
-	      u32 rx_fib_index, snat_session_t **sessionp,
-	      vlib_node_runtime_t *node, u32 next, u32 thread_index, f64 now)
-{
-  snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
-  ip4_address_t outside_addr;
-  u16 outside_port;
-  u32 outside_fib_index;
-  u8 is_identity_nat;
-
-  u32 nat_proto = ip_proto_to_nat_proto (proto);
-  snat_session_t *s = NULL;
-  lb_nat_type_t lb = 0;
-  ip4_address_t daddr = r_addr;
-  u16 dport = r_port;
-
-  if (PREDICT_TRUE (nat_proto == NAT_PROTOCOL_TCP))
-    {
-      if (PREDICT_FALSE
-	  (!tcp_flags_is_init
-	   (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags)))
-	{
-	  b->error = node->errors[NAT_IN2OUT_ED_ERROR_NON_SYN];
-	  return NAT_NEXT_DROP;
-	}
-    }
-
-  if (PREDICT_FALSE
-      (nat44_ed_maximum_sessions_exceeded (sm, rx_fib_index, thread_index)))
-    {
-      if (!nat_lru_free_one (sm, thread_index, now))
-	{
-	  b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_SESSIONS_EXCEEDED];
-	  nat_ipfix_logging_max_sessions (thread_index,
-					  sm->max_translations_per_thread);
-	  nat_elog_notice ("maximum sessions exceeded");
-	  return NAT_NEXT_DROP;
-	}
-    }
-
-  outside_fib_index = sm->outside_fib_index;
-
-  switch (vec_len (sm->outside_fibs))
-    {
-    case 0:
-      outside_fib_index = sm->outside_fib_index;
-      break;
-    case 1:
-      outside_fib_index = sm->outside_fibs[0].fib_index;
-      break;
-    default:
-      outside_fib_index = nat_outside_fib_index_lookup (sm, r_addr);
-      break;
-    }
-
-  ip4_address_t sm_addr;
-  u16 sm_port;
-  u32 sm_fib_index;
-  /* First try to match static mapping by local address and port */
-  int is_sm;
-  if (snat_static_mapping_match (sm, l_addr, l_port, rx_fib_index, nat_proto,
-				 &sm_addr, &sm_port, &sm_fib_index, 0, 0, 0,
-				 &lb, 0, &is_identity_nat, 0))
-    {
-      is_sm = 0;
-    }
-  else
-    {
-      is_sm = 1;
-    }
-
-  if (PREDICT_FALSE (is_sm && is_identity_nat))
-    {
-      *sessionp = NULL;
-      return next;
-    }
-
-  s = nat_ed_session_alloc (sm, thread_index, now, proto);
-  ASSERT (s);
-
-  if (!is_sm)
-    {
-      s->in2out.addr = l_addr;
-      s->in2out.port = l_port;
-      s->nat_proto = nat_proto;
-      s->in2out.fib_index = rx_fib_index;
-      s->out2in.fib_index = outside_fib_index;
-
-      // suggest using local port to allocation function
-      outside_port = l_port;
-
-      // hairpinning?
-      int is_hairpinning = nat44_ed_external_sm_lookup (
-	sm, r_addr, r_port, nat_proto, outside_fib_index, &daddr, &dport);
-      s->flags |= is_hairpinning * SNAT_SESSION_FLAG_HAIRPINNING;
-
-      // destination addr/port updated with real values in
-      // nat_ed_alloc_addr_and_port
-      nat_6t_o2i_flow_init (sm, thread_index, s, daddr, dport, daddr, 0,
-			    s->out2in.fib_index, proto);
-      nat_6t_flow_daddr_rewrite_set (&s->o2i, l_addr.as_u32);
-      if (NAT_PROTOCOL_ICMP == nat_proto)
-	{
-	  nat_6t_flow_icmp_id_rewrite_set (&s->o2i, l_port);
-	}
-      else
-	{
-	  nat_6t_flow_dport_rewrite_set (&s->o2i, l_port);
-	}
-      nat_6t_flow_txfib_rewrite_set (&s->o2i, rx_fib_index);
-
-      if (nat_ed_alloc_addr_and_port (
-	    sm, rx_fib_index, nat_proto, thread_index, daddr, dport, proto,
-	    sm->port_per_thread, tsm->snat_thread_index, s, &outside_addr,
-	    &outside_port))
-	{
-	  nat_elog_notice ("addresses exhausted");
-	  b->error = node->errors[NAT_IN2OUT_ED_ERROR_OUT_OF_PORTS];
-	  nat_ed_session_delete (sm, s, thread_index, 1);
-	  return NAT_NEXT_DROP;
-	}
-      s->out2in.addr = outside_addr;
-      s->out2in.port = outside_port;
-    }
-  else
-    {
-      // static mapping
-      s->out2in.addr = outside_addr = sm_addr;
-      s->out2in.port = outside_port = sm_port;
-      s->in2out.addr = l_addr;
-      s->in2out.port = l_port;
-      s->nat_proto = nat_proto;
-      s->in2out.fib_index = rx_fib_index;
-      s->out2in.fib_index = outside_fib_index;
-      s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
-
-      // hairpinning?
-      int is_hairpinning = nat44_ed_external_sm_lookup (
-	sm, r_addr, r_port, nat_proto, outside_fib_index, &daddr, &dport);
-      s->flags |= is_hairpinning * SNAT_SESSION_FLAG_HAIRPINNING;
-
-      if (NAT_PROTOCOL_ICMP == nat_proto)
-	{
-	  nat_6t_o2i_flow_init (sm, thread_index, s, daddr, sm_port, sm_addr,
-				sm_port, s->out2in.fib_index, proto);
-	  nat_6t_flow_icmp_id_rewrite_set (&s->o2i, l_port);
-	}
-      else
-	{
-	  nat_6t_o2i_flow_init (sm, thread_index, s, daddr, dport, sm_addr,
-				sm_port, s->out2in.fib_index, proto);
-	  nat_6t_flow_dport_rewrite_set (&s->o2i, l_port);
-	}
-      nat_6t_flow_daddr_rewrite_set (&s->o2i, l_addr.as_u32);
-      nat_6t_flow_txfib_rewrite_set (&s->o2i, rx_fib_index);
-      if (nat_ed_ses_o2i_flow_hash_add_del (sm, thread_index, s, 2))
-	{
-	  nat_elog_notice ("out2in key add failed");
-	  goto error;
-	}
-    }
-
-  if (lb)
-    s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
-  s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
-  s->ext_host_addr = r_addr;
-  s->ext_host_port = r_port;
-
-  nat_6t_i2o_flow_init (sm, thread_index, s, l_addr, l_port, r_addr, r_port,
-			rx_fib_index, proto);
-  nat_6t_flow_saddr_rewrite_set (&s->i2o, outside_addr.as_u32);
-  nat_6t_flow_daddr_rewrite_set (&s->i2o, daddr.as_u32);
-  if (NAT_PROTOCOL_ICMP == nat_proto)
-    {
-      nat_6t_flow_icmp_id_rewrite_set (&s->i2o, outside_port);
-    }
-  else
-    {
-      nat_6t_flow_sport_rewrite_set (&s->i2o, outside_port);
-      nat_6t_flow_dport_rewrite_set (&s->i2o, dport);
-    }
-  nat_6t_flow_txfib_rewrite_set (&s->i2o, outside_fib_index);
-
-  if (nat_ed_ses_i2o_flow_hash_add_del (sm, thread_index, s, 1))
-    {
-      nat_elog_notice ("in2out key add failed");
-      goto error;
-    }
-
-  /* log NAT event */
-  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,
-			 0);
-
-  per_vrf_sessions_register_session (s, thread_index);
-
-  *sessionp = s;
-  return next;
-error:
-  if (s)
-    {
-      if (!is_sm)
-	{
-	  snat_free_outside_address_and_port (sm->addresses, thread_index,
-					      &outside_addr, outside_port,
-					      nat_proto);
-	}
-      nat_ed_session_delete (sm, s, thread_index, 1);
-    }
-  *sessionp = s = NULL;
-  return NAT_NEXT_DROP;
-}
-
-static_always_inline int
-nat44_ed_not_translate (snat_main_t * sm, vlib_node_runtime_t * node,
-			u32 sw_if_index, ip4_header_t * ip, u32 proto,
-			u32 rx_fib_index, u32 thread_index)
-{
-  udp_header_t *udp = ip4_next_header (ip);
-  clib_bihash_kv_16_8_t kv, value;
-
-  init_ed_k (&kv, ip->dst_address, udp->dst_port, ip->src_address,
-	     udp->src_port, sm->outside_fib_index, ip->protocol);
-
-  /* NAT packet aimed at external address if has active sessions */
-  if (clib_bihash_search_16_8 (&sm->flow_hash, &kv, &value))
-    {
-      /* or is static mappings */
-      ip4_address_t placeholder_addr;
-      u16 placeholder_port;
-      u32 placeholder_fib_index;
-      if (!snat_static_mapping_match
-	  (sm, ip->dst_address, udp->dst_port, sm->outside_fib_index, proto,
-	   &placeholder_addr, &placeholder_port, &placeholder_fib_index, 1, 0,
-	   0, 0, 0, 0, 0))
-	return 0;
-    }
-  else
-    return 0;
-
-  if (sm->forwarding_enabled)
-    return 1;
-
-  return snat_not_translate_fast (sm, node, sw_if_index, ip, proto,
-				  rx_fib_index);
-}
-
-static_always_inline int
-nat_not_translate_output_feature_fwd (snat_main_t * sm, ip4_header_t * ip,
-				      u32 thread_index, f64 now,
-				      vlib_main_t * vm, vlib_buffer_t * b)
-{
-  clib_bihash_kv_16_8_t kv, value;
-  snat_session_t *s = 0;
-  snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
-
-  if (!sm->forwarding_enabled)
-    return 0;
-
-  if (ip->protocol == IP_PROTOCOL_ICMP)
-    {
-      ip4_address_t lookup_saddr, lookup_daddr;
-      u16 lookup_sport, lookup_dport;
-      u8 lookup_protocol;
-      if (nat_get_icmp_session_lookup_values (b, ip, &lookup_saddr,
-					      &lookup_sport, &lookup_daddr,
-					      &lookup_dport, &lookup_protocol))
-	return 0;
-      init_ed_k (&kv, lookup_saddr, lookup_sport, lookup_daddr, lookup_dport,
-		 0, lookup_protocol);
-    }
-  else if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
-    {
-      init_ed_k (&kv, ip->src_address, vnet_buffer (b)->ip.reass.l4_src_port,
-		 ip->dst_address, vnet_buffer (b)->ip.reass.l4_dst_port, 0,
-		 ip->protocol);
-    }
-  else
-    {
-      init_ed_k (&kv, ip->src_address, 0, ip->dst_address, 0, 0,
-		 ip->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));
-
-      if (is_fwd_bypass_session (s))
-	{
-	  if (ip->protocol == IP_PROTOCOL_TCP)
-	    {
-	      nat44_set_tcp_session_state_i2o (sm, now, s, b, 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 1;
-	}
-      else
-	return 0;
-    }
-
-  return 0;
-}
-
-static_always_inline int
-nat44_ed_not_translate_output_feature (snat_main_t * sm, ip4_header_t * ip,
-				       u16 src_port, u16 dst_port,
-				       u32 thread_index, u32 rx_sw_if_index,
-				       u32 tx_sw_if_index, f64 now)
-{
-  clib_bihash_kv_16_8_t kv, value;
-  snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
-  snat_interface_t *i;
-  snat_session_t *s;
-  u32 rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (rx_sw_if_index);
-  u32 tx_fib_index = ip4_fib_table_get_index_for_sw_if_index (tx_sw_if_index);
-
-  /* src NAT check */
-  init_ed_k (&kv, ip->src_address, src_port, ip->dst_address, dst_port,
-	     tx_fib_index, ip->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));
-      if (nat44_is_ses_closed (s)
-	  && (!s->tcp_closed_timestamp || now >= s->tcp_closed_timestamp))
-	{
-	  nat_free_session_data (sm, s, thread_index, 0);
-	  nat_ed_session_delete (sm, s, thread_index, 1);
-	}
-      return 1;
-    }
-
-  /* dst NAT check */
-  init_ed_k (&kv, ip->dst_address, dst_port, ip->src_address, src_port,
-	     rx_fib_index, ip->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));
-
-      if (is_fwd_bypass_session (s))
-	return 0;
-
-      /* hairpinning */
-      /* *INDENT-OFF* */
-      pool_foreach (i, sm->output_feature_interfaces)
-       {
-        if ((nat_interface_is_inside (i)) && (rx_sw_if_index == i->sw_if_index))
-           return 0;
-      }
-      /* *INDENT-ON* */
-      return 1;
-    }
-
-  return 0;
-}
-
-static inline u32
-icmp_in2out_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,
-			  nat_protocol_t nat_proto, snat_session_t **s_p)
-{
-  vlib_main_t *vm = vlib_get_main ();
-  u16 checksum;
-  int err;
-  snat_session_t *s = NULL;
-  u8 lookup_protocol = ip->protocol;
-  u16 lookup_sport, lookup_dport;
-  ip4_address_t lookup_saddr, lookup_daddr;
-
-  err = nat_get_icmp_session_lookup_values (b, ip, &lookup_saddr,
-					    &lookup_sport, &lookup_daddr,
-					    &lookup_dport, &lookup_protocol);
-  if (err != 0)
-    {
-      b->error = node->errors[err];
-      return NAT_NEXT_DROP;
-    }
-
-  if (vnet_buffer (b)->sw_if_index[VLIB_TX] != ~0)
-    {
-      if (PREDICT_FALSE (nat44_ed_not_translate_output_feature (
-	    sm, ip, lookup_sport, lookup_dport, thread_index, sw_if_index,
-	    vnet_buffer (b)->sw_if_index[VLIB_TX], now)))
-	{
-	  return next;
-	}
-    }
-  else
-    {
-      if (PREDICT_FALSE (nat44_ed_not_translate (sm, node, sw_if_index, ip,
-						 NAT_PROTOCOL_ICMP,
-						 rx_fib_index, thread_index)))
-	{
-	  return next;
-	}
-    }
-
-  if (PREDICT_FALSE (icmp_type_is_error_message (
-	vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags)))
-    {
-      b->error = node->errors[NAT_IN2OUT_ED_ERROR_BAD_ICMP_TYPE];
-      return NAT_NEXT_DROP;
-    }
-
-  next = slow_path_ed (sm, b, ip->src_address, ip->dst_address, lookup_sport,
-		       lookup_dport, ip->protocol, rx_fib_index, &s, node,
-		       next, thread_index, vlib_time_now (vm));
-
-  if (NAT_NEXT_DROP == next)
-    goto out;
-
-  if (PREDICT_TRUE (!ip4_is_fragment (ip)))
-    {
-      ip_csum_t 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 (PREDICT_FALSE (checksum != 0 && checksum != 0xffff))
-	{
-	  next = NAT_NEXT_DROP;
-	  goto out;
-	}
-    }
-
-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);
-    }
-  *s_p = s;
-  return next;
-}
-
-static snat_session_t *
-nat44_ed_in2out_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;
-  clib_bihash_kv_16_8_t s_kv, s_value;
-  snat_static_mapping_t *m = NULL;
-  snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
-  snat_session_t *s = NULL;
-  u32 outside_fib_index = sm->outside_fib_index;
-  int i;
-  ip4_address_t new_src_addr = { 0 };
-  ip4_address_t new_dst_addr = ip->dst_address;
-
-  if (PREDICT_FALSE (
-	nat44_ed_maximum_sessions_exceeded (sm, rx_fib_index, thread_index)))
-    {
-      b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_SESSIONS_EXCEEDED];
-      nat_ipfix_logging_max_sessions (thread_index,
-				      sm->max_translations_per_thread);
-      nat_elog_notice ("maximum sessions exceeded");
-      return 0;
-    }
-
-  switch (vec_len (sm->outside_fibs))
-    {
-    case 0:
-      outside_fib_index = sm->outside_fib_index;
-      break;
-    case 1:
-      outside_fib_index = sm->outside_fibs[0].fib_index;
-      break;
-    default:
-      outside_fib_index = nat_outside_fib_index_lookup (sm, ip->dst_address);
-      break;
-    }
-
-  init_nat_k (&kv, ip->src_address, 0, rx_fib_index, 0);
-
-  /* Try to find static mapping first */
-  if (!clib_bihash_search_8_8 (&sm->static_mapping_by_local, &kv, &value))
-    {
-      m = pool_elt_at_index (sm->static_mappings, value.value);
-      new_src_addr = m->external_addr;
-    }
-  else
-    {
-      pool_foreach (s, tsm->sessions)
-	{
-	  if (s->ext_host_addr.as_u32 == ip->dst_address.as_u32)
-	    {
-	      init_ed_k (&s_kv, s->out2in.addr, 0, ip->dst_address, 0,
-			 outside_fib_index, ip->protocol);
-	      if (clib_bihash_search_16_8 (&sm->flow_hash, &s_kv, &s_value))
-		{
-		  new_src_addr = s->out2in.addr;
-		}
-	      break;
-	    }
-	}
-
-      if (!new_src_addr.as_u32)
-	{
-	  for (i = 0; i < vec_len (sm->addresses); i++)
-	    {
-	      init_ed_k (&s_kv, sm->addresses[i].addr, 0, ip->dst_address, 0,
-			 outside_fib_index, ip->protocol);
-	      if (clib_bihash_search_16_8 (&sm->flow_hash, &s_kv, &s_value))
-		{
-		  new_src_addr = sm->addresses[i].addr;
-		}
-	    }
-	}
-    }
-
-  if (!new_src_addr.as_u32)
-    {
-      // could not allocate address for translation ...
-      return 0;
-    }
-
-  s = nat_ed_session_alloc (sm, thread_index, now, ip->protocol);
-  if (!s)
-    {
-      b->error = node->errors[NAT_IN2OUT_ED_ERROR_MAX_SESSIONS_EXCEEDED];
-      nat_elog_warn ("create NAT session failed");
-      return 0;
-    }
-
-  nat_6t_i2o_flow_init (sm, thread_index, s, ip->src_address, 0,
-			ip->dst_address, 0, rx_fib_index, ip->protocol);
-  nat_6t_flow_saddr_rewrite_set (&s->i2o, new_src_addr.as_u32);
-  nat_6t_flow_txfib_rewrite_set (&s->i2o, outside_fib_index);
-
-  // hairpinning?
-  int is_hairpinning =
-    nat44_ed_external_sm_lookup (sm, ip->dst_address, 0, NAT_PROTOCOL_OTHER,
-				 outside_fib_index, &new_dst_addr, NULL);
-  s->flags |= is_hairpinning * SNAT_SESSION_FLAG_HAIRPINNING;
-
-  nat_6t_flow_daddr_rewrite_set (&s->i2o, new_dst_addr.as_u32);
-  nat_6t_flow_txfib_rewrite_set (&s->i2o, outside_fib_index);
-
-  nat_6t_o2i_flow_init (sm, thread_index, s, new_dst_addr, 0, new_src_addr, 0,
-			outside_fib_index, ip->protocol);
-  nat_6t_flow_saddr_rewrite_set (&s->o2i, ip->dst_address.as_u32);
-  nat_6t_flow_daddr_rewrite_set (&s->o2i, ip->src_address.as_u32);
-  nat_6t_flow_txfib_rewrite_set (&s->o2i, rx_fib_index);
-
-  s->ext_host_addr.as_u32 = ip->dst_address.as_u32;
-  s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
-  s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
-  s->out2in.addr.as_u32 = new_src_addr.as_u32;
-  s->out2in.fib_index = outside_fib_index;
-  s->in2out.addr.as_u32 = ip->src_address.as_u32;
-  s->in2out.fib_index = rx_fib_index;
-  s->in2out.port = s->out2in.port = ip->protocol;
-  if (m)
-    s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
-
-  if (nat_ed_ses_i2o_flow_hash_add_del (sm, thread_index, s, 1))
-    {
-      nat_elog_notice ("in2out flow hash add failed");
-      nat_ed_session_delete (sm, s, thread_index, 1);
-      return NULL;
-    }
-
-  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_in2out_fast_path_node_fn_inline (vlib_main_t * vm,
-					  vlib_node_runtime_t * node,
-					  vlib_frame_t * frame,
-					  int is_output_feature)
-{
-  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];
-  u32 def_slow = is_output_feature ? NAT_NEXT_IN2OUT_ED_OUTPUT_SLOW_PATH
-    : NAT_NEXT_IN2OUT_ED_SLOW_PATH;
-
-  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, iph_offset0 = 0;
-      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++;
-
-      /* 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);
-	}
-
-      if (is_output_feature)
-	{
-	  iph_offset0 = vnet_buffer (b0)->ip.reass.save_rewrite_length;
-	}
-
-      next[0] = vnet_buffer2 (b0)->nat.arc_next;
-
-      ip0 =
-	(ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) + iph_offset0);
-
-      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 (is_output_feature)
-	{
-	  if (PREDICT_FALSE
-	      (nat_not_translate_output_feature_fwd
-	       (sm, ip0, thread_index, now, vm, b0)))
-	    goto trace0;
-	}
-
-      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_IN2OUT_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_protocol = ip0->protocol;
-	  lookup_saddr = ip0->src_address;
-	  lookup_daddr = ip0->dst_address;
-	  lookup_sport = vnet_buffer (b0)->ip.reass.l4_src_port;
-	  lookup_dport = vnet_buffer (b0)->ip.reass.l4_dst_port;
-	}
-
-      /* 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->i2o, b0, lookup_saddr, lookup_sport,
-				   lookup_daddr, lookup_dport, lookup_protocol,
-				   rx_fib_index0)
-		// for some hairpinning cases there are two "i2i" flows instead
-		// of i2o and o2i as both hosts are on inside
-		|| (s0->flags & SNAT_SESSION_FLAG_HAIRPINNING &&
-		    nat_6t_flow_match (
-		      &s0->o2i, 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, ip0->src_address, lookup_sport, ip0->dst_address,
-		 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] = def_slow;
-	  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] = def_slow;
-	    }
-	  else
-	    {
-	      // session in transitory timeout, drop
-	      b0->error = node->errors[NAT_IN2OUT_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)
-	{
-	  nat_free_session_data (sm, s0, thread_index, 0);
-	  nat_ed_session_delete (sm, s0, thread_index, 1);
-	  // session is closed, go slow path
-	  next[0] = def_slow;
-	  goto trace0;
-	}
-
-      b0->flags |= VNET_BUFFER_F_IS_NATED;
-
-      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 if (s0->flags & SNAT_SESSION_FLAG_HAIRPINNING &&
-	       nat_6t_flow_match (&s0->o2i, b0, lookup_saddr, lookup_sport,
-				  lookup_daddr, lookup_dport, lookup_protocol,
-				  rx_fib_index0))
-	{
-	  f = &s0->o2i;
-	}
-      else
-	{
-	  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, is_output_feature)))
-	{
-	  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;
-	}
-
-      switch (proto0)
-	{
-	case NAT_PROTOCOL_TCP:
-	  vlib_increment_simple_counter (&sm->counters.fastpath.in2out_ed.tcp,
-					 thread_index, sw_if_index0, 1);
-	  nat44_set_tcp_session_state_i2o (sm, now, s0, b0, thread_index);
-	  break;
-	case NAT_PROTOCOL_UDP:
-	  vlib_increment_simple_counter (&sm->counters.fastpath.in2out_ed.udp,
-					 thread_index, sw_if_index0, 1);
-	  break;
-	case NAT_PROTOCOL_ICMP:
-	  vlib_increment_simple_counter (&sm->counters.fastpath.in2out_ed.icmp,
-					 thread_index, sw_if_index0, 1);
-	  break;
-	case NAT_PROTOCOL_OTHER:
-	  vlib_increment_simple_counter (
-	    &sm->counters.fastpath.in2out_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)))
-	{
-	  nat_in2out_ed_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;
-	  t->lookup_skipped = lookup_skipped;
-	  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));
-	      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.
-					 in2out_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_in2out_slow_path_node_fn_inline (vlib_main_t * vm,
-					  vlib_node_runtime_t * node,
-					  vlib_frame_t * frame,
-					  int is_output_feature)
-{
-  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, iph_offset0 = 0;
-      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;
-      int translation_error = NAT_ED_TRNSL_ERR_SUCCESS;
-
-      b0 = *b;
-
-      if (is_output_feature)
-	iph_offset0 = vnet_buffer (b0)->ip.reass.save_rewrite_length;
-
-      next[0] = vnet_buffer2 (b0)->nat.arc_next;
-
-      ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
-			      iph_offset0);
-
-      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_in2out_slowpath_unknown_proto (
-	    sm, b0, ip0, rx_fib_index0, thread_index, now, vm, node);
-	  if (!s0)
-	    next[0] = NAT_NEXT_DROP;
-
-	  if (NAT_ED_TRNSL_ERR_SUCCESS !=
-	      (translation_error = nat_6t_flow_buf_translate (
-		 sm, b0, ip0, &s0->i2o, proto0, is_output_feature)))
-	    {
-	      goto trace0;
-	    }
-
-	  vlib_increment_simple_counter (&sm->counters.slowpath.
-					 in2out_ed.other, thread_index,
-					 sw_if_index0, 1);
-	  goto trace0;
-	}
-
-      if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
-	{
-	  next[0] = icmp_in2out_ed_slow_path (sm, b0, ip0, icmp0, sw_if_index0,
-					      rx_fib_index0, node, next[0],
-					      now, thread_index, proto0, &s0);
-	  if (NAT_NEXT_DROP != next[0] && s0 &&
-	      NAT_ED_TRNSL_ERR_SUCCESS !=
-		(translation_error = nat_6t_flow_buf_translate (
-		   sm, b0, ip0, &s0->i2o, proto0, is_output_feature)))
-	    {
-	      goto trace0;
-	    }
-
-	  vlib_increment_simple_counter (&sm->counters.slowpath.
-					 in2out_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);
-      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)
-	{
-	  if (is_output_feature)
-	    {
-	      if (PREDICT_FALSE
-		  (nat44_ed_not_translate_output_feature
-		   (sm, ip0, vnet_buffer (b0)->ip.reass.l4_src_port,
-		    vnet_buffer (b0)->ip.reass.l4_dst_port, thread_index,
-		    sw_if_index0, vnet_buffer (b0)->sw_if_index[VLIB_TX],
-		    now)))
-		goto trace0;
-
-	      /*
-	       * 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_server))
-		   && ip0->dst_address.as_u32 == 0xffffffff))
-		goto trace0;
-	    }
-	  else
-	    {
-	      if (PREDICT_FALSE
-		  (nat44_ed_not_translate
-		   (sm, node, sw_if_index0, ip0, proto0, rx_fib_index0,
-		    thread_index)))
-		goto trace0;
-	    }
-
-	  next[0] =
-	    slow_path_ed (sm, b0, ip0->src_address, ip0->dst_address,
-			  vnet_buffer (b0)->ip.reass.l4_src_port,
-			  vnet_buffer (b0)->ip.reass.l4_dst_port,
-			  ip0->protocol, rx_fib_index0, &s0, node, next[0],
-			  thread_index, now);
-
-	  if (PREDICT_FALSE (next[0] == NAT_NEXT_DROP))
-	    goto trace0;
-
-	  if (PREDICT_FALSE (!s0))
-	    goto trace0;
-
-	}
-
-      b0->flags |= VNET_BUFFER_F_IS_NATED;
-
-      if (NAT_ED_TRNSL_ERR_SUCCESS !=
-	  (translation_error = nat_6t_flow_buf_translate (
-	     sm, b0, ip0, &s0->i2o, proto0, is_output_feature)))
-	{
-	  nat_free_session_data (sm, s0, thread_index, 0);
-	  nat_ed_session_delete (sm, s0, thread_index, 1);
-	  s0 = NULL;
-	  goto trace0;
-	}
-
-      if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
-	{
-	  vlib_increment_simple_counter (&sm->counters.slowpath.in2out_ed.tcp,
-					 thread_index, sw_if_index0, 1);
-	  nat44_set_tcp_session_state_i2o (sm, now, s0, b0, thread_index);
-	}
-      else
-	{
-	  vlib_increment_simple_counter (&sm->counters.slowpath.in2out_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)))
-	{
-	  nat_in2out_ed_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));
-	      t->translation_via_i2of = 1;
-	    }
-
-	  else
-	    {
-	      t->session_index = ~0;
-	    }
-	}
-
-      if (next[0] == NAT_NEXT_DROP)
-	{
-	  vlib_increment_simple_counter (&sm->counters.slowpath.
-					 in2out_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_in2out_node) (vlib_main_t * vm,
-				     vlib_node_runtime_t * node,
-				     vlib_frame_t * frame)
-{
-  return nat44_ed_in2out_fast_path_node_fn_inline (vm, node, frame, 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_fast_path_node_fn_inline (vm, node, frame, 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_slow_path_node_fn_inline (vm, node, frame, 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_slow_path_node_fn_inline (vm, node, frame, 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* */
-
-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 arc_next_index %d", t->next_index,
-		 t->arc_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);
-}
-
-VLIB_NODE_FN (nat_pre_in2out_output_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_OUTPUT_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,
-};
-
-VLIB_REGISTER_NODE (nat_pre_in2out_output_node) = {
-  .name = "nat-pre-in2out-output",
-  .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:
- */