nat: refactor and split fo EI/ED features

This patch is aimed at moving EI features out of NAT44
plugin & split of EI/ED functions.

Type: refactor

Change-Id: I63cf70a264ed2512708fe92665d64f04690783d0
Signed-off-by: Filip Varga <fivarga@cisco.com>

1 files changed, 0 insertions, 1585 deletions

diff --git a/src/plugins/nat/out2in.c b/src/plugins/nat/out2in.c
deleted file mode 100644
index c8c4542ab83..00000000000
--- a/src/plugins/nat/out2in.c
+++ /dev/null
@@ -1,1585 +0,0 @@
-/*
- * Copyright (c) 2016 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/udp/udp_local.h>
-#include <vnet/ethernet/ethernet.h>
-#include <vnet/fib/ip4_fib.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/nat_ha.h>
-
-#include <vppinfra/hash.h>
-#include <vppinfra/error.h>
-#include <vppinfra/elog.h>
-
-typedef struct
-{
-  u32 sw_if_index;
-  u32 next_index;
-  u32 session_index;
-} snat_out2in_trace_t;
-
-/* packet trace format function */
-static u8 *
-format_snat_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 *);
-  snat_out2in_trace_t *t = va_arg (*args, snat_out2in_trace_t *);
-
-  s =
-    format (s,
-	    "NAT44_OUT2IN: sw_if_index %d, next index %d, session index %d",
-	    t->sw_if_index, t->next_index, t->session_index);
-  return s;
-}
-
-static u8 *
-format_snat_out2in_fast_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 *);
-  snat_out2in_trace_t *t = va_arg (*args, snat_out2in_trace_t *);
-
-  s = format (s, "NAT44_OUT2IN_FAST: sw_if_index %d, next index %d",
-	      t->sw_if_index, t->next_index);
-  return s;
-}
-
-#define foreach_snat_out2in_error                       \
-_(UNSUPPORTED_PROTOCOL, "unsupported protocol")         \
-_(OUT_OF_PORTS, "out of ports")                         \
-_(BAD_ICMP_TYPE, "unsupported ICMP type")               \
-_(NO_TRANSLATION, "no translation")                     \
-_(MAX_SESSIONS_EXCEEDED, "maximum sessions exceeded")   \
-_(CANNOT_CREATE_USER, "cannot create NAT user")
-
-typedef enum
-{
-#define _(sym,str) SNAT_OUT2IN_ERROR_##sym,
-  foreach_snat_out2in_error
-#undef _
-    SNAT_OUT2IN_N_ERROR,
-} snat_out2in_error_t;
-
-static char *snat_out2in_error_strings[] = {
-#define _(sym,string) string,
-  foreach_snat_out2in_error
-#undef _
-};
-
-typedef enum
-{
-  SNAT_OUT2IN_NEXT_DROP,
-  SNAT_OUT2IN_NEXT_LOOKUP,
-  SNAT_OUT2IN_NEXT_ICMP_ERROR,
-  SNAT_OUT2IN_N_NEXT,
-} snat_out2in_next_t;
-
-#ifndef CLIB_MARCH_VARIANT
-int
-nat44_o2i_is_idle_session_cb (clib_bihash_kv_8_8_t * kv, void *arg)
-{
-  snat_main_t *sm = &snat_main;
-  nat44_is_idle_session_ctx_t *ctx = arg;
-  snat_session_t *s;
-  u64 sess_timeout_time;
-  snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
-						       ctx->thread_index);
-  clib_bihash_kv_8_8_t s_kv;
-
-  s = pool_elt_at_index (tsm->sessions, kv->value);
-  sess_timeout_time = s->last_heard + (f64) nat44_session_get_timeout (sm, s);
-  if (ctx->now >= sess_timeout_time)
-    {
-      init_nat_i2o_k (&s_kv, s);
-      if (clib_bihash_add_del_8_8 (&tsm->in2out, &s_kv, 0))
-	nat_elog_warn ("out2in key del failed");
-
-      nat_ipfix_logging_nat44_ses_delete (ctx->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_apmdel (s->user_index, s->in2out.fib_index,
-			       &s->in2out.addr, s->in2out.port,
-			       &s->out2in.addr, s->out2in.port, s->nat_proto);
-
-      nat_ha_sdel (&s->out2in.addr, s->out2in.port, &s->ext_host_addr,
-		   s->ext_host_port, s->nat_proto, s->out2in.fib_index,
-		   ctx->thread_index);
-
-      if (!snat_is_session_static (s))
-	snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
-					    &s->out2in.addr, s->out2in.port,
-					    s->nat_proto);
-
-      nat44_delete_session (sm, s, ctx->thread_index);
-      return 1;
-    }
-
-  return 0;
-}
-#endif
-
-/**
- * @brief Create session for static mapping.
- *
- * Create NAT session initiated by host from external network with static
- * mapping.
- *
- * @param sm     NAT main.
- * @param b0     Vlib buffer.
- * @param in2out In2out NAT44 session key.
- * @param out2in Out2in NAT44 session key.
- * @param node   Vlib node.
- *
- * @returns SNAT session if successfully created otherwise 0.
- */
-static inline snat_session_t *
-create_session_for_static_mapping (snat_main_t * sm,
-				   vlib_buffer_t * b0,
-				   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 proto,
-				   vlib_node_runtime_t * node,
-				   u32 thread_index, f64 now)
-{
-  snat_user_t *u;
-  snat_session_t *s;
-  clib_bihash_kv_8_8_t kv0;
-  ip4_header_t *ip0;
-  udp_header_t *udp0;
-  nat44_is_idle_session_ctx_t ctx0;
-
-  if (PREDICT_FALSE (nat44_maximum_sessions_exceeded (sm, thread_index)))
-    {
-      b0->error = node->errors[SNAT_OUT2IN_ERROR_MAX_SESSIONS_EXCEEDED];
-      nat_elog_notice ("maximum sessions exceeded");
-      return 0;
-    }
-
-  ip0 = vlib_buffer_get_current (b0);
-  udp0 = ip4_next_header (ip0);
-
-  u = nat_user_get_or_create (sm, &i2o_addr, i2o_fib_index, thread_index);
-  if (!u)
-    {
-      b0->error = node->errors[SNAT_OUT2IN_ERROR_CANNOT_CREATE_USER];
-      return 0;
-    }
-
-  s = nat_session_alloc_or_recycle (sm, u, thread_index, now);
-  if (!s)
-    {
-      nat44_delete_user_with_no_session (sm, u, thread_index);
-      nat_elog_warn ("create NAT session failed");
-      return 0;
-    }
-
-  s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
-  s->ext_host_addr.as_u32 = ip0->src_address.as_u32;
-  s->ext_host_port = udp0->src_port;
-  user_session_increment (sm, u, 1 /* static */ );
-  s->in2out.addr = i2o_addr;
-  s->in2out.port = i2o_port;
-  s->in2out.fib_index = i2o_fib_index;
-  s->out2in.addr = o2i_addr;
-  s->out2in.port = o2i_port;
-  s->out2in.fib_index = o2i_fib_index;
-  s->nat_proto = proto;
-
-  /* Add to translation hashes */
-  ctx0.now = now;
-  ctx0.thread_index = thread_index;
-  init_nat_i2o_kv (&kv0, s, s - sm->per_thread_data[thread_index].sessions);
-  if (clib_bihash_add_or_overwrite_stale_8_8
-      (&sm->per_thread_data[thread_index].in2out, &kv0,
-       nat44_i2o_is_idle_session_cb, &ctx0))
-    nat_elog_notice ("in2out key add failed");
-
-  init_nat_o2i_kv (&kv0, s, s - sm->per_thread_data[thread_index].sessions);
-  if (clib_bihash_add_or_overwrite_stale_8_8
-      (&sm->per_thread_data[thread_index].out2in, &kv0,
-       nat44_o2i_is_idle_session_cb, &ctx0))
-    nat_elog_notice ("out2in key add failed");
-
-  /* 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_apmadd (s->user_index, s->in2out.fib_index,
-			   &s->in2out.addr, s->in2out.port, &s->out2in.addr,
-			   s->out2in.port, s->nat_proto);
-
-  nat_ha_sadd (&s->in2out.addr, s->in2out.port, &s->out2in.addr,
-	       s->out2in.port, &s->ext_host_addr, s->ext_host_port,
-	       &s->ext_host_nat_addr, s->ext_host_nat_port,
-	       s->nat_proto, s->in2out.fib_index, s->flags, thread_index, 0);
-
-  return s;
-}
-
-#ifndef CLIB_MARCH_VARIANT
-static_always_inline snat_out2in_error_t
-icmp_get_key (vlib_buffer_t * b, ip4_header_t * ip0,
-	      ip4_address_t * addr, u16 * port, nat_protocol_t * nat_proto)
-{
-  icmp46_header_t *icmp0;
-  icmp_echo_header_t *echo0, *inner_echo0 = 0;
-  ip4_header_t *inner_ip0;
-  void *l4_header = 0;
-  icmp46_header_t *inner_icmp0;
-
-  icmp0 = (icmp46_header_t *) ip4_next_header (ip0);
-  echo0 = (icmp_echo_header_t *) (icmp0 + 1);
-
-  if (!icmp_type_is_error_message
-      (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags))
-    {
-      *nat_proto = NAT_PROTOCOL_ICMP;
-      *addr = ip0->dst_address;
-      *port = vnet_buffer (b)->ip.reass.l4_src_port;
-    }
-  else
-    {
-      inner_ip0 = (ip4_header_t *) (echo0 + 1);
-      l4_header = ip4_next_header (inner_ip0);
-      *nat_proto = ip_proto_to_nat_proto (inner_ip0->protocol);
-      *addr = inner_ip0->src_address;
-      switch (*nat_proto)
-	{
-	case NAT_PROTOCOL_ICMP:
-	  inner_icmp0 = (icmp46_header_t *) l4_header;
-	  inner_echo0 = (icmp_echo_header_t *) (inner_icmp0 + 1);
-	  *port = inner_echo0->identifier;
-	  break;
-	case NAT_PROTOCOL_UDP:
-	case NAT_PROTOCOL_TCP:
-	  *port = ((tcp_udp_header_t *) l4_header)->src_port;
-	  break;
-	default:
-	  return SNAT_OUT2IN_ERROR_UNSUPPORTED_PROTOCOL;
-	}
-    }
-  return -1;			/* success */
-}
-
-/**
- * Get address and port values to be used for ICMP packet translation
- * and create session if needed
- *
- * @param[in,out] sm             NAT main
- * @param[in,out] node           NAT node runtime
- * @param[in] thread_index       thread index
- * @param[in,out] b0             buffer containing packet to be translated
- * @param[in,out] ip0            ip header
- * @param[out] p_proto           protocol used for matching
- * @param[out] p_value           address and port after NAT translation
- * @param[out] p_dont_translate  if packet should not be translated
- * @param d                      optional parameter
- * @param e                      optional parameter
- */
-u32
-icmp_match_out2in_slow (snat_main_t * sm, vlib_node_runtime_t * node,
-			u32 thread_index, vlib_buffer_t * b0,
-			ip4_header_t * ip0, ip4_address_t * addr,
-			u16 * port, u32 * fib_index,
-			nat_protocol_t * proto, void *d, void *e,
-			u8 * dont_translate)
-{
-  snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
-  u32 sw_if_index0;
-  snat_session_t *s0 = 0;
-  clib_bihash_kv_8_8_t kv0, value0;
-  u8 is_addr_only;
-  u32 next0 = ~0;
-  int err;
-  u8 identity_nat;
-  vlib_main_t *vm = vlib_get_main ();
-  *dont_translate = 0;
-
-  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
-  *fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
-
-  *proto = 0;
-
-  err = icmp_get_key (b0, ip0, addr, port, proto);
-  if (err != -1)
-    {
-      b0->error = node->errors[SNAT_OUT2IN_ERROR_UNSUPPORTED_PROTOCOL];
-      next0 = SNAT_OUT2IN_NEXT_DROP;
-      goto out;
-    }
-
-  ip4_address_t mapping_addr;
-  u16 mapping_port;
-  u32 mapping_fib_index;
-
-  init_nat_k (&kv0, *addr, *port, *fib_index, *proto);
-  if (clib_bihash_search_8_8 (&tsm->out2in, &kv0, &value0))
-    {
-      /* Try to match static mapping by external address and port,
-         destination address and port in packet */
-      if (snat_static_mapping_match
-	  (sm, *addr, *port, *fib_index, *proto,
-	   &mapping_addr, &mapping_port, &mapping_fib_index, 1, &is_addr_only,
-	   0, 0, 0, &identity_nat, 0))
-	{
-	  if (!sm->forwarding_enabled)
-	    {
-	      /* Don't NAT packet aimed at the intfc address */
-	      if (PREDICT_FALSE (is_interface_addr (sm, node, sw_if_index0,
-						    ip0->dst_address.as_u32)))
-		{
-		  *dont_translate = 1;
-		  goto out;
-		}
-	      b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
-	      next0 = SNAT_OUT2IN_NEXT_DROP;
-	      goto out;
-	    }
-	  else
-	    {
-	      *dont_translate = 1;
-	      goto out;
-	    }
-	}
-
-      if (PREDICT_FALSE
-	  (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
-	   ICMP4_echo_reply
-	   && (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
-	       ICMP4_echo_request || !is_addr_only)))
-	{
-	  b0->error = node->errors[SNAT_OUT2IN_ERROR_BAD_ICMP_TYPE];
-	  next0 = SNAT_OUT2IN_NEXT_DROP;
-	  goto out;
-	}
-
-      if (PREDICT_FALSE (identity_nat))
-	{
-	  *dont_translate = 1;
-	  goto out;
-	}
-      /* Create session initiated by host from external network */
-      s0 =
-	create_session_for_static_mapping (sm, b0, mapping_addr, mapping_port,
-					   mapping_fib_index, *addr, *port,
-					   *fib_index, *proto, node,
-					   thread_index, vlib_time_now (vm));
-
-      if (!s0)
-	{
-	  next0 = SNAT_OUT2IN_NEXT_DROP;
-	  goto out;
-	}
-    }
-  else
-    {
-      if (PREDICT_FALSE
-	  (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
-	   ICMP4_echo_reply
-	   && vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
-	   ICMP4_echo_request
-	   && !icmp_type_is_error_message (vnet_buffer (b0)->ip.
-					   reass.icmp_type_or_tcp_flags)))
-	{
-	  b0->error = node->errors[SNAT_OUT2IN_ERROR_BAD_ICMP_TYPE];
-	  next0 = SNAT_OUT2IN_NEXT_DROP;
-	  goto out;
-	}
-
-      s0 = pool_elt_at_index (tsm->sessions, value0.value);
-    }
-
-out:
-  if (s0)
-    {
-      *addr = s0->in2out.addr;
-      *port = s0->in2out.port;
-      *fib_index = s0->in2out.fib_index;
-    }
-  if (d)
-    *(snat_session_t **) d = s0;
-  return next0;
-}
-#endif
-
-#ifndef CLIB_MARCH_VARIANT
-/**
- * Get address and port values to be used for ICMP packet translation
- *
- * @param[in] sm                 NAT main
- * @param[in,out] node           NAT node runtime
- * @param[in] thread_index       thread index
- * @param[in,out] b0             buffer containing packet to be translated
- * @param[in,out] ip0            ip header
- * @param[out] p_proto           protocol used for matching
- * @param[out] p_value           address and port after NAT translation
- * @param[out] p_dont_translate  if packet should not be translated
- * @param d                      optional parameter
- * @param e                      optional parameter
- */
-u32
-icmp_match_out2in_fast (snat_main_t * sm, vlib_node_runtime_t * node,
-			u32 thread_index, vlib_buffer_t * b0,
-			ip4_header_t * ip0, ip4_address_t * mapping_addr,
-			u16 * mapping_port, u32 * mapping_fib_index,
-			nat_protocol_t * proto, void *d, void *e,
-			u8 * dont_translate)
-{
-  u32 sw_if_index0;
-  u32 rx_fib_index0;
-  u8 is_addr_only;
-  u32 next0 = ~0;
-  int err;
-  ip4_address_t addr;
-  u16 port;
-  *dont_translate = 0;
-
-  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
-  rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
-
-  err = icmp_get_key (b0, ip0, &addr, &port, proto);
-  if (err != -1)
-    {
-      b0->error = node->errors[err];
-      next0 = SNAT_OUT2IN_NEXT_DROP;
-      goto out;
-    }
-  if (snat_static_mapping_match
-      (sm, addr, port, rx_fib_index0, *proto, mapping_addr, mapping_port,
-       mapping_fib_index, 1, &is_addr_only, 0, 0, 0, 0, 0))
-    {
-      /* Don't NAT packet aimed at the intfc address */
-      if (is_interface_addr (sm, node, sw_if_index0, ip0->dst_address.as_u32))
-	{
-	  *dont_translate = 1;
-	  goto out;
-	}
-      b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
-      next0 = SNAT_OUT2IN_NEXT_DROP;
-      goto out;
-    }
-
-  if (PREDICT_FALSE
-      (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags != ICMP4_echo_reply
-       && (vnet_buffer (b0)->ip.reass.icmp_type_or_tcp_flags !=
-	   ICMP4_echo_request || !is_addr_only)
-       && !icmp_type_is_error_message (vnet_buffer (b0)->ip.
-				       reass.icmp_type_or_tcp_flags)))
-    {
-      b0->error = node->errors[SNAT_OUT2IN_ERROR_BAD_ICMP_TYPE];
-      next0 = SNAT_OUT2IN_NEXT_DROP;
-      goto out;
-    }
-
-out:
-  return next0;
-}
-#endif
-
-#ifndef CLIB_MARCH_VARIANT
-u32
-icmp_out2in (snat_main_t * sm,
-	     vlib_buffer_t * b0,
-	     ip4_header_t * ip0,
-	     icmp46_header_t * icmp0,
-	     u32 sw_if_index0,
-	     u32 rx_fib_index0,
-	     vlib_node_runtime_t * node,
-	     u32 next0, u32 thread_index, void *d, void *e)
-{
-  icmp_echo_header_t *echo0, *inner_echo0 = 0;
-  ip4_header_t *inner_ip0 = 0;
-  void *l4_header = 0;
-  icmp46_header_t *inner_icmp0;
-  u8 dont_translate;
-  u32 new_addr0, old_addr0;
-  u16 old_id0, new_id0;
-  ip_csum_t sum0;
-  u16 checksum0;
-  u32 next0_tmp;
-  vlib_main_t *vm = vlib_get_main ();
-  ip4_address_t addr;
-  u16 port;
-  u32 fib_index;
-  nat_protocol_t proto;
-
-  echo0 = (icmp_echo_header_t *) (icmp0 + 1);
-
-  next0_tmp = sm->icmp_match_out2in_cb (sm, node, thread_index, b0, ip0,
-					&addr, &port, &fib_index, &proto,
-					d, e, &dont_translate);
-  if (next0_tmp != ~0)
-    next0 = next0_tmp;
-  if (next0 == SNAT_OUT2IN_NEXT_DROP || dont_translate)
-    goto out;
-
-  if (PREDICT_TRUE (!ip4_is_fragment (ip0)))
-    {
-      sum0 =
-	ip_incremental_checksum_buffer (vm, b0,
-					(u8 *) icmp0 -
-					(u8 *) vlib_buffer_get_current (b0),
-					ntohs (ip0->length) -
-					ip4_header_bytes (ip0), 0);
-      checksum0 = ~ip_csum_fold (sum0);
-      if (checksum0 != 0 && checksum0 != 0xffff)
-	{
-	  next0 = SNAT_OUT2IN_NEXT_DROP;
-	  goto out;
-	}
-    }
-
-  old_addr0 = ip0->dst_address.as_u32;
-  new_addr0 = ip0->dst_address.as_u32 = addr.as_u32;
-  vnet_buffer (b0)->sw_if_index[VLIB_TX] = fib_index;
-
-  sum0 = ip0->checksum;
-  sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
-			 dst_address /* changed member */ );
-  ip0->checksum = ip_csum_fold (sum0);
-
-
-  if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
-    {
-      if (icmp0->checksum == 0)
-	icmp0->checksum = 0xffff;
-
-      if (!icmp_type_is_error_message (icmp0->type))
-	{
-	  new_id0 = port;
-	  if (PREDICT_FALSE (new_id0 != echo0->identifier))
-	    {
-	      old_id0 = echo0->identifier;
-	      new_id0 = port;
-	      echo0->identifier = new_id0;
-
-	      sum0 = icmp0->checksum;
-	      sum0 =
-		ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
-				identifier /* changed member */ );
-	      icmp0->checksum = ip_csum_fold (sum0);
-	    }
-	}
-      else
-	{
-	  inner_ip0 = (ip4_header_t *) (echo0 + 1);
-	  l4_header = ip4_next_header (inner_ip0);
-
-	  if (!ip4_header_checksum_is_valid (inner_ip0))
-	    {
-	      next0 = SNAT_OUT2IN_NEXT_DROP;
-	      goto out;
-	    }
-
-	  old_addr0 = inner_ip0->src_address.as_u32;
-	  inner_ip0->src_address = addr;
-	  new_addr0 = inner_ip0->src_address.as_u32;
-
-	  sum0 = icmp0->checksum;
-	  sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
-				 src_address /* changed member */ );
-	  icmp0->checksum = ip_csum_fold (sum0);
-
-	  switch (proto)
-	    {
-	    case NAT_PROTOCOL_ICMP:
-	      inner_icmp0 = (icmp46_header_t *) l4_header;
-	      inner_echo0 = (icmp_echo_header_t *) (inner_icmp0 + 1);
-
-	      old_id0 = inner_echo0->identifier;
-	      new_id0 = port;
-	      inner_echo0->identifier = new_id0;
-
-	      sum0 = icmp0->checksum;
-	      sum0 =
-		ip_csum_update (sum0, old_id0, new_id0, icmp_echo_header_t,
-				identifier);
-	      icmp0->checksum = ip_csum_fold (sum0);
-	      break;
-	    case NAT_PROTOCOL_UDP:
-	    case NAT_PROTOCOL_TCP:
-	      old_id0 = ((tcp_udp_header_t *) l4_header)->src_port;
-	      new_id0 = port;
-	      ((tcp_udp_header_t *) l4_header)->src_port = new_id0;
-
-	      sum0 = icmp0->checksum;
-	      sum0 = ip_csum_update (sum0, old_id0, new_id0, tcp_udp_header_t,
-				     src_port);
-	      icmp0->checksum = ip_csum_fold (sum0);
-	      break;
-	    default:
-	      ASSERT (0);
-	    }
-	}
-    }
-
-out:
-  return next0;
-}
-#endif
-
-static inline u32
-icmp_out2in_slow_path (snat_main_t * sm,
-		       vlib_buffer_t * b0,
-		       ip4_header_t * ip0,
-		       icmp46_header_t * icmp0,
-		       u32 sw_if_index0,
-		       u32 rx_fib_index0,
-		       vlib_node_runtime_t * node,
-		       u32 next0, f64 now,
-		       u32 thread_index, snat_session_t ** p_s0)
-{
-  vlib_main_t *vm = vlib_get_main ();
-
-  next0 = icmp_out2in (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
-		       next0, thread_index, p_s0, 0);
-  snat_session_t *s0 = *p_s0;
-  if (PREDICT_TRUE (next0 != SNAT_OUT2IN_NEXT_DROP && s0))
-    {
-      /* 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);
-    }
-  return next0;
-}
-
-static int
-nat_out2in_sm_unknown_proto (snat_main_t * sm,
-			     vlib_buffer_t * b,
-			     ip4_header_t * ip, u32 rx_fib_index)
-{
-  clib_bihash_kv_8_8_t kv, value;
-  snat_static_mapping_t *m;
-  u32 old_addr, new_addr;
-  ip_csum_t sum;
-
-  init_nat_k (&kv, ip->dst_address, 0, 0, 0);
-  if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
-    return 1;
-
-  m = pool_elt_at_index (sm->static_mappings, value.value);
-
-  old_addr = ip->dst_address.as_u32;
-  new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
-  sum = ip->checksum;
-  sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
-  ip->checksum = ip_csum_fold (sum);
-
-  vnet_buffer (b)->sw_if_index[VLIB_TX] = m->fib_index;
-  return 0;
-}
-
-VLIB_NODE_FN (snat_out2in_node) (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];
-
-  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 >= 2)
-    {
-      vlib_buffer_t *b0, *b1;
-      u32 next0 = SNAT_OUT2IN_NEXT_LOOKUP;
-      u32 next1 = SNAT_OUT2IN_NEXT_LOOKUP;
-      u32 sw_if_index0, sw_if_index1;
-      ip4_header_t *ip0, *ip1;
-      ip_csum_t sum0, sum1;
-      u32 new_addr0, old_addr0;
-      u16 new_port0, old_port0;
-      u32 new_addr1, old_addr1;
-      u16 new_port1, old_port1;
-      udp_header_t *udp0, *udp1;
-      tcp_header_t *tcp0, *tcp1;
-      icmp46_header_t *icmp0, *icmp1;
-      u32 rx_fib_index0, rx_fib_index1;
-      u32 proto0, proto1;
-      snat_session_t *s0 = 0, *s1 = 0;
-      clib_bihash_kv_8_8_t kv0, kv1, value0, value1;
-      u8 identity_nat0, identity_nat1;
-      ip4_address_t sm_addr0, sm_addr1;
-      u16 sm_port0, sm_port1;
-      u32 sm_fib_index0, sm_fib_index1;
-
-      b0 = *b;
-      b++;
-      b1 = *b;
-      b++;
-
-      /* Prefetch next iteration. */
-      if (PREDICT_TRUE (n_left_from >= 4))
-	{
-	  vlib_buffer_t *p2, *p3;
-
-	  p2 = *b;
-	  p3 = *(b + 1);
-
-	  vlib_prefetch_buffer_header (p2, LOAD);
-	  vlib_prefetch_buffer_header (p3, LOAD);
-
-	  CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, LOAD);
-	  CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, LOAD);
-	}
-
-      vnet_buffer (b0)->snat.flags = 0;
-      vnet_buffer (b1)->snat.flags = 0;
-
-      ip0 = vlib_buffer_get_current (b0);
-      udp0 = ip4_next_header (ip0);
-      tcp0 = (tcp_header_t *) udp0;
-      icmp0 = (icmp46_header_t *) udp0;
-
-      sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
-      rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
-			       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);
-	  next0 = SNAT_OUT2IN_NEXT_ICMP_ERROR;
-	  goto trace0;
-	}
-
-      proto0 = ip_proto_to_nat_proto (ip0->protocol);
-
-      if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
-	{
-	  if (nat_out2in_sm_unknown_proto (sm, b0, ip0, rx_fib_index0))
-	    {
-	      if (!sm->forwarding_enabled)
-		{
-		  b0->error =
-		    node->errors[SNAT_OUT2IN_ERROR_UNSUPPORTED_PROTOCOL];
-		  next0 = SNAT_OUT2IN_NEXT_DROP;
-		}
-	    }
-	  vlib_increment_simple_counter (&sm->counters.slowpath.out2in.other,
-					 thread_index, sw_if_index0, 1);
-
-	  goto trace0;
-	}
-
-      if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
-	{
-	  next0 = icmp_out2in_slow_path
-	    (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
-	     next0, now, thread_index, &s0);
-	  vlib_increment_simple_counter (&sm->counters.slowpath.out2in.icmp,
-					 thread_index, sw_if_index0, 1);
-	  goto trace0;
-	}
-
-      init_nat_k (&kv0, ip0->dst_address,
-		  vnet_buffer (b0)->ip.reass.l4_dst_port, rx_fib_index0,
-		  proto0);
-      if (clib_bihash_search_8_8
-	  (&sm->per_thread_data[thread_index].out2in, &kv0, &value0))
-	{
-	  /* 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_addr0, &sm_port0, &sm_fib_index0, 1, 0, 0, 0,
-	       0, &identity_nat0, 0))
-	    {
-	      /*
-	       * 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))))
-		{
-		  vnet_feature_next (&next0, b0);
-		  goto trace0;
-		}
-
-	      if (!sm->forwarding_enabled)
-		{
-		  b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
-		  next0 = SNAT_OUT2IN_NEXT_DROP;
-		}
-	      goto trace0;
-	    }
-
-	  if (PREDICT_FALSE (identity_nat0))
-	    goto trace0;
-
-	  /* Create session initiated by host from external network */
-	  s0 = create_session_for_static_mapping (sm, b0,
-						  sm_addr0, sm_port0,
-						  sm_fib_index0,
-						  ip0->dst_address,
-						  vnet_buffer (b0)->ip.
-						  reass.l4_dst_port,
-						  rx_fib_index0, proto0, node,
-						  thread_index, now);
-	  if (!s0)
-	    {
-	      next0 = SNAT_OUT2IN_NEXT_DROP;
-	      goto trace0;
-	    }
-	}
-      else
-	s0 = pool_elt_at_index (tsm->sessions, value0.value);
-
-      old_addr0 = ip0->dst_address.as_u32;
-      ip0->dst_address = s0->in2out.addr;
-      new_addr0 = ip0->dst_address.as_u32;
-      vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
-
-      sum0 = ip0->checksum;
-      sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
-			     ip4_header_t, dst_address /* changed member */ );
-      ip0->checksum = ip_csum_fold (sum0);
-
-      if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
-	{
-	  if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
-	    {
-	      old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
-	      new_port0 = udp0->dst_port = s0->in2out.port;
-	      sum0 = tcp0->checksum;
-	      sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
-				     ip4_header_t,
-				     dst_address /* changed member */ );
-
-	      sum0 = ip_csum_update (sum0, old_port0, new_port0,
-				     ip4_header_t /* cheat */ ,
-				     length /* changed member */ );
-	      tcp0->checksum = ip_csum_fold (sum0);
-	    }
-	  vlib_increment_simple_counter (&sm->counters.slowpath.out2in.tcp,
-					 thread_index, sw_if_index0, 1);
-	}
-      else
-	{
-	  if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
-	    {
-	      old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
-	      new_port0 = udp0->dst_port = s0->in2out.port;
-	      if (PREDICT_FALSE (udp0->checksum))
-		{
-		  sum0 = udp0->checksum;
-		  sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t, dst_address	/* changed member */
-		    );
-		  sum0 =
-		    ip_csum_update (sum0, old_port0, new_port0,
-				    ip4_header_t /* cheat */ ,
-				    length /* changed member */ );
-		  udp0->checksum = ip_csum_fold (sum0);
-		}
-	    }
-	  vlib_increment_simple_counter (&sm->counters.slowpath.out2in.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)))
-	{
-	  snat_out2in_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
-	  t->sw_if_index = sw_if_index0;
-	  t->next_index = next0;
-	  t->session_index = ~0;
-	  if (s0)
-	    t->session_index =
-	      s0 - sm->per_thread_data[thread_index].sessions;
-	}
-
-      if (next0 == SNAT_OUT2IN_NEXT_DROP)
-	{
-	  vlib_increment_simple_counter (&sm->counters.slowpath.out2in.drops,
-					 thread_index, sw_if_index0, 1);
-	}
-
-
-      ip1 = vlib_buffer_get_current (b1);
-      udp1 = ip4_next_header (ip1);
-      tcp1 = (tcp_header_t *) udp1;
-      icmp1 = (icmp46_header_t *) udp1;
-
-      sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
-      rx_fib_index1 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
-			       sw_if_index1);
-
-      if (PREDICT_FALSE (ip1->ttl == 1))
-	{
-	  vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
-	  icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded,
-				       ICMP4_time_exceeded_ttl_exceeded_in_transit,
-				       0);
-	  next1 = SNAT_OUT2IN_NEXT_ICMP_ERROR;
-	  goto trace1;
-	}
-
-      proto1 = ip_proto_to_nat_proto (ip1->protocol);
-
-      if (PREDICT_FALSE (proto1 == NAT_PROTOCOL_OTHER))
-	{
-	  if (nat_out2in_sm_unknown_proto (sm, b1, ip1, rx_fib_index1))
-	    {
-	      if (!sm->forwarding_enabled)
-		{
-		  b1->error =
-		    node->errors[SNAT_OUT2IN_ERROR_UNSUPPORTED_PROTOCOL];
-		  next1 = SNAT_OUT2IN_NEXT_DROP;
-		}
-	    }
-	  vlib_increment_simple_counter (&sm->counters.slowpath.out2in.other,
-					 thread_index, sw_if_index1, 1);
-	  goto trace1;
-	}
-
-      if (PREDICT_FALSE (proto1 == NAT_PROTOCOL_ICMP))
-	{
-	  next1 = icmp_out2in_slow_path
-	    (sm, b1, ip1, icmp1, sw_if_index1, rx_fib_index1, node,
-	     next1, now, thread_index, &s1);
-	  vlib_increment_simple_counter (&sm->counters.slowpath.out2in.icmp,
-					 thread_index, sw_if_index1, 1);
-	  goto trace1;
-	}
-
-      init_nat_k (&kv1, ip1->dst_address,
-		  vnet_buffer (b1)->ip.reass.l4_dst_port, rx_fib_index1,
-		  proto1);
-
-      if (clib_bihash_search_8_8
-	  (&sm->per_thread_data[thread_index].out2in, &kv1, &value1))
-	{
-	  /* Try to match static mapping by external address and port,
-	     destination address and port in packet */
-	  if (snat_static_mapping_match
-	      (sm, ip1->dst_address,
-	       vnet_buffer (b1)->ip.reass.l4_dst_port, proto1,
-	       rx_fib_index1, &sm_addr1, &sm_port1, &sm_fib_index1, 1, 0,
-	       0, 0, 0, &identity_nat1, 0))
-	    {
-	      /*
-	       * Send DHCP packets to the ipv4 stack, or we won't
-	       * be able to use dhcp client on the outside interface
-	       */
-	      if (PREDICT_FALSE
-		  (proto1 == NAT_PROTOCOL_UDP
-		   && (vnet_buffer (b1)->ip.reass.l4_dst_port ==
-		       clib_host_to_net_u16 (UDP_DST_PORT_dhcp_to_client))))
-		{
-		  vnet_feature_next (&next1, b1);
-		  goto trace1;
-		}
-
-	      if (!sm->forwarding_enabled)
-		{
-		  b1->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
-		  next1 = SNAT_OUT2IN_NEXT_DROP;
-		}
-	      goto trace1;
-	    }
-
-	  if (PREDICT_FALSE (identity_nat1))
-	    goto trace1;
-
-	  /* Create session initiated by host from external network */
-	  s1 =
-	    create_session_for_static_mapping (sm, b1, sm_addr1, sm_port1,
-					       sm_fib_index1,
-					       ip1->dst_address,
-					       vnet_buffer (b1)->ip.
-					       reass.l4_dst_port,
-					       rx_fib_index1, proto1, node,
-					       thread_index, now);
-	  if (!s1)
-	    {
-	      next1 = SNAT_OUT2IN_NEXT_DROP;
-	      goto trace1;
-	    }
-	}
-      else
-	s1 =
-	  pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
-			     value1.value);
-
-      old_addr1 = ip1->dst_address.as_u32;
-      ip1->dst_address = s1->in2out.addr;
-      new_addr1 = ip1->dst_address.as_u32;
-      vnet_buffer (b1)->sw_if_index[VLIB_TX] = s1->in2out.fib_index;
-
-      sum1 = ip1->checksum;
-      sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
-			     ip4_header_t, dst_address /* changed member */ );
-      ip1->checksum = ip_csum_fold (sum1);
-
-      if (PREDICT_TRUE (proto1 == NAT_PROTOCOL_TCP))
-	{
-	  if (!vnet_buffer (b1)->ip.reass.is_non_first_fragment)
-	    {
-	      old_port1 = vnet_buffer (b1)->ip.reass.l4_dst_port;
-	      new_port1 = udp1->dst_port = s1->in2out.port;
-
-	      sum1 = tcp1->checksum;
-	      sum1 = ip_csum_update (sum1, old_addr1, new_addr1,
-				     ip4_header_t,
-				     dst_address /* changed member */ );
-
-	      sum1 = ip_csum_update (sum1, old_port1, new_port1,
-				     ip4_header_t /* cheat */ ,
-				     length /* changed member */ );
-	      tcp1->checksum = ip_csum_fold (sum1);
-	    }
-	  vlib_increment_simple_counter (&sm->counters.slowpath.out2in.tcp,
-					 thread_index, sw_if_index1, 1);
-	}
-      else
-	{
-	  if (!vnet_buffer (b1)->ip.reass.is_non_first_fragment)
-	    {
-	      old_port1 = vnet_buffer (b1)->ip.reass.l4_dst_port;
-	      new_port1 = udp1->dst_port = s1->in2out.port;
-	      if (PREDICT_FALSE (udp1->checksum))
-		{
-
-		  sum1 = udp1->checksum;
-		  sum1 =
-		    ip_csum_update (sum1, old_addr1, new_addr1,
-				    ip4_header_t,
-				    dst_address /* changed member */ );
-		  sum1 =
-		    ip_csum_update (sum1, old_port1, new_port1,
-				    ip4_header_t /* cheat */ ,
-				    length /* changed member */ );
-		  udp1->checksum = ip_csum_fold (sum1);
-		}
-	    }
-	  vlib_increment_simple_counter (&sm->counters.slowpath.out2in.udp,
-					 thread_index, sw_if_index1, 1);
-	}
-
-      /* Accounting */
-      nat44_session_update_counters (s1, now,
-				     vlib_buffer_length_in_chain (vm, b1),
-				     thread_index);
-      /* Per-user LRU list maintenance */
-      nat44_session_update_lru (sm, s1, thread_index);
-    trace1:
-
-      if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
-			 && (b1->flags & VLIB_BUFFER_IS_TRACED)))
-	{
-	  snat_out2in_trace_t *t = vlib_add_trace (vm, node, b1, sizeof (*t));
-	  t->sw_if_index = sw_if_index1;
-	  t->next_index = next1;
-	  t->session_index = ~0;
-	  if (s1)
-	    t->session_index =
-	      s1 - sm->per_thread_data[thread_index].sessions;
-	}
-
-      if (next1 == SNAT_OUT2IN_NEXT_DROP)
-	{
-	  vlib_increment_simple_counter (&sm->counters.slowpath.out2in.drops,
-					 thread_index, sw_if_index1, 1);
-	}
-
-      n_left_from -= 2;
-      next[0] = next0;
-      next[1] = next1;
-      next += 2;
-    }
-
-  while (n_left_from > 0)
-    {
-      vlib_buffer_t *b0;
-      u32 next0 = SNAT_OUT2IN_NEXT_LOOKUP;
-      u32 sw_if_index0;
-      ip4_header_t *ip0;
-      ip_csum_t sum0;
-      u32 new_addr0, old_addr0;
-      u16 new_port0, old_port0;
-      udp_header_t *udp0;
-      tcp_header_t *tcp0;
-      icmp46_header_t *icmp0;
-      u32 rx_fib_index0;
-      u32 proto0;
-      snat_session_t *s0 = 0;
-      clib_bihash_kv_8_8_t kv0, value0;
-      u8 identity_nat0;
-      ip4_address_t sm_addr0;
-      u16 sm_port0;
-      u32 sm_fib_index0;
-
-      b0 = *b;
-      ++b;
-
-      vnet_buffer (b0)->snat.flags = 0;
-
-      ip0 = vlib_buffer_get_current (b0);
-      udp0 = ip4_next_header (ip0);
-      tcp0 = (tcp_header_t *) udp0;
-      icmp0 = (icmp46_header_t *) udp0;
-
-      sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
-      rx_fib_index0 = vec_elt (sm->ip4_main->fib_index_by_sw_if_index,
-			       sw_if_index0);
-
-      proto0 = ip_proto_to_nat_proto (ip0->protocol);
-
-      if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
-	{
-	  if (nat_out2in_sm_unknown_proto (sm, b0, ip0, rx_fib_index0))
-	    {
-	      if (!sm->forwarding_enabled)
-		{
-		  b0->error =
-		    node->errors[SNAT_OUT2IN_ERROR_UNSUPPORTED_PROTOCOL];
-		  next0 = SNAT_OUT2IN_NEXT_DROP;
-		}
-	    }
-	  vlib_increment_simple_counter (&sm->counters.slowpath.out2in.other,
-					 thread_index, sw_if_index0, 1);
-	  goto trace00;
-	}
-
-      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);
-	  next0 = SNAT_OUT2IN_NEXT_ICMP_ERROR;
-	  goto trace00;
-	}
-
-      if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
-	{
-	  next0 = icmp_out2in_slow_path
-	    (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
-	     next0, now, thread_index, &s0);
-	  vlib_increment_simple_counter (&sm->counters.slowpath.out2in.icmp,
-					 thread_index, sw_if_index0, 1);
-	  goto trace00;
-	}
-
-      init_nat_k (&kv0, ip0->dst_address,
-		  vnet_buffer (b0)->ip.reass.l4_dst_port, rx_fib_index0,
-		  proto0);
-
-      if (clib_bihash_search_8_8
-	  (&sm->per_thread_data[thread_index].out2in, &kv0, &value0))
-	{
-	  /* 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_addr0, &sm_port0, &sm_fib_index0, 1, 0, 0, 0,
-	       0, &identity_nat0, 0))
-	    {
-	      /*
-	       * 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))))
-		{
-		  vnet_feature_next (&next0, b0);
-		  goto trace00;
-		}
-
-	      if (!sm->forwarding_enabled)
-		{
-		  b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
-		  next0 = SNAT_OUT2IN_NEXT_DROP;
-		}
-	      goto trace00;
-	    }
-
-	  if (PREDICT_FALSE (identity_nat0))
-	    goto trace00;
-
-	  /* Create session initiated by host from external network */
-	  s0 = create_session_for_static_mapping (sm, b0,
-						  sm_addr0, sm_port0,
-						  sm_fib_index0,
-						  ip0->dst_address,
-						  vnet_buffer (b0)->ip.
-						  reass.l4_dst_port,
-						  rx_fib_index0, proto0, node,
-						  thread_index, now);
-	  if (!s0)
-	    {
-	      next0 = SNAT_OUT2IN_NEXT_DROP;
-	      goto trace00;
-	    }
-	}
-      else
-	s0 =
-	  pool_elt_at_index (sm->per_thread_data[thread_index].sessions,
-			     value0.value);
-
-      old_addr0 = ip0->dst_address.as_u32;
-      ip0->dst_address = s0->in2out.addr;
-      new_addr0 = ip0->dst_address.as_u32;
-      vnet_buffer (b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index;
-
-      sum0 = ip0->checksum;
-      sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
-			     ip4_header_t, dst_address /* changed member */ );
-      ip0->checksum = ip_csum_fold (sum0);
-
-      if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
-	{
-	  if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
-	    {
-	      old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
-	      new_port0 = udp0->dst_port = s0->in2out.port;
-
-	      sum0 = tcp0->checksum;
-	      sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
-				     ip4_header_t,
-				     dst_address /* changed member */ );
-
-	      sum0 = ip_csum_update (sum0, old_port0, new_port0,
-				     ip4_header_t /* cheat */ ,
-				     length /* changed member */ );
-	      tcp0->checksum = ip_csum_fold (sum0);
-	    }
-	  vlib_increment_simple_counter (&sm->counters.slowpath.out2in.tcp,
-					 thread_index, sw_if_index0, 1);
-	}
-      else
-	{
-	  if (!vnet_buffer (b0)->ip.reass.is_non_first_fragment)
-	    {
-	      old_port0 = vnet_buffer (b0)->ip.reass.l4_dst_port;
-	      new_port0 = udp0->dst_port = s0->in2out.port;
-	      if (PREDICT_FALSE (udp0->checksum))
-		{
-		  sum0 = udp0->checksum;
-		  sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t, dst_address	/* changed member */
-		    );
-		  sum0 =
-		    ip_csum_update (sum0, old_port0, new_port0,
-				    ip4_header_t /* cheat */ ,
-				    length /* changed member */ );
-		  udp0->checksum = ip_csum_fold (sum0);
-		}
-	    }
-	  vlib_increment_simple_counter (&sm->counters.slowpath.out2in.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);
-    trace00:
-
-      if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
-			 && (b0->flags & VLIB_BUFFER_IS_TRACED)))
-	{
-	  snat_out2in_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
-	  t->sw_if_index = sw_if_index0;
-	  t->next_index = next0;
-	  t->session_index = ~0;
-	  if (s0)
-	    t->session_index =
-	      s0 - sm->per_thread_data[thread_index].sessions;
-	}
-
-      if (next0 == SNAT_OUT2IN_NEXT_DROP)
-	{
-	  vlib_increment_simple_counter (&sm->counters.slowpath.out2in.drops,
-					 thread_index, sw_if_index0, 1);
-	}
-
-      n_left_from--;
-      next[0] = next0;
-      next++;
-    }
-
-  vlib_buffer_enqueue_to_next (vm, node, from, (u16 *) nexts,
-			       frame->n_vectors);
-
-  return frame->n_vectors;
-}
-
-/* *INDENT-OFF* */
-VLIB_REGISTER_NODE (snat_out2in_node) = {
-  .name = "nat44-out2in",
-  .vector_size = sizeof (u32),
-  .format_trace = format_snat_out2in_trace,
-  .type = VLIB_NODE_TYPE_INTERNAL,
-
-  .n_errors = ARRAY_LEN(snat_out2in_error_strings),
-  .error_strings = snat_out2in_error_strings,
-
-  .runtime_data_bytes = sizeof (snat_runtime_t),
-
-  .n_next_nodes = SNAT_OUT2IN_N_NEXT,
-
-  /* edit / add dispositions here */
-  .next_nodes = {
-    [SNAT_OUT2IN_NEXT_DROP] = "error-drop",
-    [SNAT_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
-    [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
-  },
-};
-/* *INDENT-ON* */
-
-VLIB_NODE_FN (snat_out2in_fast_node) (vlib_main_t * vm,
-				      vlib_node_runtime_t * node,
-				      vlib_frame_t * frame)
-{
-  u32 n_left_from, *from;
-  snat_main_t *sm = &snat_main;
-
-  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 next0 = SNAT_OUT2IN_NEXT_DROP;
-      u32 sw_if_index0;
-      ip4_header_t *ip0;
-      ip_csum_t sum0;
-      u32 new_addr0, old_addr0;
-      u16 new_port0, old_port0;
-      udp_header_t *udp0;
-      tcp_header_t *tcp0;
-      icmp46_header_t *icmp0;
-      u32 proto0;
-      u32 rx_fib_index0;
-      ip4_address_t sm_addr0;
-      u16 sm_port0;
-      u32 sm_fib_index0;
-
-      b0 = *b;
-      b++;
-
-      ip0 = vlib_buffer_get_current (b0);
-      udp0 = ip4_next_header (ip0);
-      tcp0 = (tcp_header_t *) udp0;
-      icmp0 = (icmp46_header_t *) udp0;
-
-      sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
-      rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
-
-      vnet_feature_next (&next0, b0);
-
-      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);
-	  next0 = SNAT_OUT2IN_NEXT_ICMP_ERROR;
-	  goto trace00;
-	}
-
-      proto0 = ip_proto_to_nat_proto (ip0->protocol);
-
-      if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_OTHER))
-	goto trace00;
-
-      if (PREDICT_FALSE (proto0 == NAT_PROTOCOL_ICMP))
-	{
-	  next0 = icmp_out2in (sm, b0, ip0, icmp0, sw_if_index0,
-			       rx_fib_index0, node, next0, ~0, 0, 0);
-	  goto trace00;
-	}
-
-      if (snat_static_mapping_match
-	  (sm, ip0->dst_address, udp0->dst_port, rx_fib_index0, proto0,
-	   &sm_addr0, &sm_port0, &sm_fib_index0, 1, 0, 0, 0, 0, 0, 0))
-	{
-	  b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION];
-	  goto trace00;
-	}
-
-      new_addr0 = sm_addr0.as_u32;
-      new_port0 = sm_port0;
-      vnet_buffer (b0)->sw_if_index[VLIB_TX] = sm_fib_index0;
-      old_addr0 = ip0->dst_address.as_u32;
-      ip0->dst_address.as_u32 = new_addr0;
-
-      sum0 = ip0->checksum;
-      sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
-			     ip4_header_t, dst_address /* changed member */ );
-      ip0->checksum = ip_csum_fold (sum0);
-
-      if (PREDICT_FALSE (new_port0 != udp0->dst_port))
-	{
-	  old_port0 = udp0->dst_port;
-	  udp0->dst_port = new_port0;
-
-	  if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
-	    {
-	      sum0 = tcp0->checksum;
-	      sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
-				     ip4_header_t,
-				     dst_address /* changed member */ );
-	      sum0 = ip_csum_update (sum0, old_port0, new_port0,
-				     ip4_header_t /* cheat */ ,
-				     length /* changed member */ );
-	      tcp0->checksum = ip_csum_fold (sum0);
-	    }
-	  else if (udp0->checksum)
-	    {
-	      sum0 = udp0->checksum;
-	      sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
-				     ip4_header_t,
-				     dst_address /* changed member */ );
-	      sum0 = ip_csum_update (sum0, old_port0, new_port0,
-				     ip4_header_t /* cheat */ ,
-				     length /* changed member */ );
-	      udp0->checksum = ip_csum_fold (sum0);
-	    }
-	}
-      else
-	{
-	  if (PREDICT_TRUE (proto0 == NAT_PROTOCOL_TCP))
-	    {
-	      sum0 = tcp0->checksum;
-	      sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
-				     ip4_header_t,
-				     dst_address /* changed member */ );
-	      tcp0->checksum = ip_csum_fold (sum0);
-	    }
-	  else if (udp0->checksum)
-	    {
-	      sum0 = udp0->checksum;
-	      sum0 = ip_csum_update (sum0, old_addr0, new_addr0,
-				     ip4_header_t,
-				     dst_address /* changed member */ );
-	      udp0->checksum = ip_csum_fold (sum0);
-	    }
-	}
-
-    trace00:
-
-      if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
-			 && (b0->flags & VLIB_BUFFER_IS_TRACED)))
-	{
-	  snat_out2in_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
-	  t->sw_if_index = sw_if_index0;
-	  t->next_index = next0;
-	}
-
-      if (next0 == SNAT_OUT2IN_NEXT_DROP)
-	{
-	  vlib_increment_simple_counter (&sm->counters.fastpath.out2in.drops,
-					 vm->thread_index, sw_if_index0, 1);
-	}
-
-      n_left_from--;
-      next[0] = next0;
-      next++;
-    }
-
-  vlib_buffer_enqueue_to_next (vm, node, from, (u16 *) nexts,
-			       frame->n_vectors);
-
-  return frame->n_vectors;
-}
-
-/* *INDENT-OFF* */
-VLIB_REGISTER_NODE (snat_out2in_fast_node) = {
-  .name = "nat44-out2in-fast",
-  .vector_size = sizeof (u32),
-  .format_trace = format_snat_out2in_fast_trace,
-  .type = VLIB_NODE_TYPE_INTERNAL,
-
-  .n_errors = ARRAY_LEN(snat_out2in_error_strings),
-  .error_strings = snat_out2in_error_strings,
-
-  .runtime_data_bytes = sizeof (snat_runtime_t),
-
-  .n_next_nodes = SNAT_OUT2IN_N_NEXT,
-
-  /* edit / add dispositions here */
-  .next_nodes = {
-    [SNAT_OUT2IN_NEXT_LOOKUP] = "ip4-lookup",
-    [SNAT_OUT2IN_NEXT_DROP] = "error-drop",
-    [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error",
-  },
-};
-/* *INDENT-ON* */
-
-/*
- * fd.io coding-style-patch-verification: ON
- *
- * Local Variables:
- * eval: (c-set-style "gnu")
- * End:
- */