text: /*
   * Copyright (c) 2018 Cisco and/or its affiliates.
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at:
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  /**
   * @file
   * @brief NAT44 endpoint-dependent outside to inside network translation
   */
  
  #include <vlib/vlib.h>
  #include <vnet/vnet.h>
  #include <vnet/pg/pg.h>
  #include <vnet/ip/ip.h>
  #include <vnet/ethernet/ethernet.h>
  #include <vnet/fib/ip4_fib.h>
  #include <vnet/udp/udp.h>
  #include <vppinfra/error.h>
  #include <nat/nat.h>
  #include <nat/nat_ipfix_logging.h>
  #include <nat/nat_reass.h>
  #include <nat/nat_inlines.h>
  #include <nat/nat_syslog.h>
  #include <nat/nat_ha.h>
  
  static char *nat_out2in_ed_error_strings[] = {
  #define _(sym,string) string,
    foreach_nat_out2in_ed_error
  #undef _
  };
  
  typedef struct
  {
    u32 sw_if_index;
    u32 next_index;
    u32 session_index;
    u32 is_slow_path;
  } nat44_ed_out2in_trace_t;
  
  static u8 *
  format_nat44_ed_out2in_trace (u8 * s, va_list * args)
  {
    CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
    CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
    nat44_ed_out2in_trace_t *t = va_arg (*args, nat44_ed_out2in_trace_t *);
    char *tag;
  
    tag =
      t->is_slow_path ? "NAT44_OUT2IN_ED_SLOW_PATH" :
      "NAT44_OUT2IN_ED_FAST_PATH";
  
    s = format (s, "%s: sw_if_index %d, next index %d, session %d", tag,
  	      t->sw_if_index, t->next_index, t->session_index);
  
    return s;
  }
  
  static inline u32
  icmp_out2in_ed_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)
  {
    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 != NAT_NEXT_DROP && s0))
      {
        /* Accounting */
        nat44_session_update_counters (s0, now,
  				     vlib_buffer_length_in_chain
  				     (sm->vlib_main, b0), thread_index);
        /* Per-user LRU list maintenance */
        nat44_session_update_lru (sm, s0, thread_index);
      }
    return next0;
  }
  
  #ifndef CLIB_MARCH_VARIANT
  int
  nat44_o2i_ed_is_idle_session_cb (clib_bihash_kv_16_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;
    nat_ed_ses_key_t ed_key;
    clib_bihash_kv_16_8_t ed_kv;
    int i;
    snat_address_t *a;
    snat_session_key_t key;
    snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
  						       ctx->thread_index);
  
    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)
      {
        ed_key.l_addr = s->in2out.addr;
        ed_key.r_addr = s->ext_host_addr;
        ed_key.fib_index = s->in2out.fib_index;
        if (snat_is_unk_proto_session (s))
  	{
  	  ed_key.proto = s->in2out.port;
  	  ed_key.r_port = 0;
  	  ed_key.l_port = 0;
  	}
        else
  	{
  	  ed_key.proto = snat_proto_to_ip_proto (s->in2out.protocol);
  	  ed_key.l_port = s->in2out.port;
  	  ed_key.r_port = s->ext_host_port;
  	}
        if (is_twice_nat_session (s))
  	{
  	  ed_key.r_addr = s->ext_host_nat_addr;
  	  ed_key.r_port = s->ext_host_nat_port;
  	}
        ed_kv.key[0] = ed_key.as_u64[0];
        ed_kv.key[1] = ed_key.as_u64[1];
        if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &ed_kv, 0))
  	nat_elog_warn ("in2out_ed key del failed");
  
        if (snat_is_unk_proto_session (s))
  	goto delete;
  
        snat_ipfix_logging_nat44_ses_delete (ctx->thread_index,
  					   s->in2out.addr.as_u32,
  					   s->out2in.addr.as_u32,
  					   s->in2out.protocol,
  					   s->in2out.port,
  					   s->out2in.port,
  					   s->in2out.fib_index);
  
        nat_syslog_nat44_sdel (s->user_index, s->in2out.fib_index,
  			     &s->in2out.addr, s->in2out.port,
  			     &s->ext_host_nat_addr, s->ext_host_nat_port,
  			     &s->out2in.addr, s->out2in.port,
  			     &s->ext_host_addr, s->ext_host_port,
  			     s->in2out.protocol, is_twice_nat_session (s));
  
        nat_ha_sdel (&s->out2in.addr, s->out2in.port, &s->ext_host_addr,
  		   s->ext_host_port, s->out2in.protocol, s->out2in.fib_index,
  		   ctx->thread_index);
  
        if (is_twice_nat_session (s))
  	{
  	  for (i = 0; i < vec_len (sm->twice_nat_addresses); i++)
  	    {
  	      key.protocol = s->in2out.protocol;
  	      key.port = s->ext_host_nat_port;
  	      a = sm->twice_nat_addresses + i;
  	      if (a->addr.as_u32 == s->ext_host_nat_addr.as_u32)
  		{
  		  snat_free_outside_address_and_port (sm->twice_nat_addresses,
  						      ctx->thread_index,
  						      &key);
  		  break;
  		}
  	    }
  	}
  
        if (snat_is_session_static (s))
  	goto delete;
  
        snat_free_outside_address_and_port (sm->addresses, ctx->thread_index,
  					  &s->out2in);
      delete:
        nat44_delete_session (sm, s, ctx->thread_index);
        return 1;
      }
  
    return 0;
  }
  #endif
  
  static snat_session_t *
  create_session_for_static_mapping_ed (snat_main_t * sm,
  				      vlib_buffer_t * b,
  				      snat_session_key_t l_key,
  				      snat_session_key_t e_key,
  				      vlib_node_runtime_t * node,
  				      u32 thread_index,
  				      twice_nat_type_t twice_nat,
  				      lb_nat_type_t lb_nat, f64 now)
  {
    snat_session_t *s;
    snat_user_t *u;
    ip4_header_t *ip;
    udp_header_t *udp;
    snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
    clib_bihash_kv_16_8_t kv;
    snat_session_key_t eh_key;
    nat44_is_idle_session_ctx_t ctx;
  
    if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
      {
        b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
        nat_elog_notice ("maximum sessions exceeded");
        return 0;
      }
  
    u = nat_user_get_or_create (sm, &l_key.addr, l_key.fib_index, thread_index);
    if (!u)
      {
        nat_elog_warn ("create NAT user failed");
        return 0;
      }
  
    s = nat_ed_session_alloc (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;
      }
  
    ip = vlib_buffer_get_current (b);
    udp = ip4_next_header (ip);
  
    s->ext_host_addr.as_u32 = ip->src_address.as_u32;
    s->ext_host_port = e_key.protocol == SNAT_PROTOCOL_ICMP ? 0 : udp->src_port;
    s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
    if (lb_nat)
      s->flags |= SNAT_SESSION_FLAG_LOAD_BALANCING;
    if (lb_nat == AFFINITY_LB_NAT)
      s->flags |= SNAT_SESSION_FLAG_AFFINITY;
    s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
    s->out2in = e_key;
    s->in2out = l_key;
    s->in2out.protocol = s->out2in.protocol;
    user_session_increment (sm, u, 1);
  
    /* Add to lookup tables */
    make_ed_kv (&kv, &e_key.addr, &s->ext_host_addr, ip->protocol,
  	      e_key.fib_index, e_key.port, s->ext_host_port);
    kv.value = s - tsm->sessions;
    ctx.now = now;
    ctx.thread_index = thread_index;
    if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->out2in_ed, &kv,
  					       nat44_o2i_ed_is_idle_session_cb,
  					       &ctx))
      nat_elog_notice ("out2in-ed key add failed");
  
    if (twice_nat == TWICE_NAT || (twice_nat == TWICE_NAT_SELF &&
  				 ip->src_address.as_u32 == l_key.addr.as_u32))
      {
        eh_key.protocol = e_key.protocol;
        if (snat_alloc_outside_address_and_port (sm->twice_nat_addresses, 0,
  					       thread_index, &eh_key,
  					       sm->port_per_thread,
  					       tsm->snat_thread_index))
  	{
  	  b->error = node->errors[NAT_OUT2IN_ED_ERROR_OUT_OF_PORTS];
  	  nat44_delete_session (sm, s, thread_index);
  	  if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &kv, 0))
  	    nat_elog_notice ("out2in-ed key del failed");
  	  return 0;
  	}
        s->ext_host_nat_addr.as_u32 = eh_key.addr.as_u32;
        s->ext_host_nat_port = eh_key.port;
        s->flags |= SNAT_SESSION_FLAG_TWICE_NAT;
        make_ed_kv (&kv, &l_key.addr, &s->ext_host_nat_addr, ip->protocol,
  		  l_key.fib_index, l_key.port, s->ext_host_nat_port);
      }
    else
      {
        make_ed_kv (&kv, &l_key.addr, &s->ext_host_addr, ip->protocol,
  		  l_key.fib_index, l_key.port, s->ext_host_port);
      }
    kv.value = s - tsm->sessions;
    if (clib_bihash_add_or_overwrite_stale_16_8 (&tsm->in2out_ed, &kv,
  					       nat44_i2o_ed_is_idle_session_cb,
  					       &ctx))
      nat_elog_notice ("in2out-ed key add failed");
  
    snat_ipfix_logging_nat44_ses_create (thread_index,
  				       s->in2out.addr.as_u32,
  				       s->out2in.addr.as_u32,
  				       s->in2out.protocol,
  				       s->in2out.port,
  				       s->out2in.port, s->in2out.fib_index);
  
    nat_syslog_nat44_sadd (s->user_index, s->in2out.fib_index,
  			 &s->in2out.addr, s->in2out.port,
  			 &s->ext_host_nat_addr, s->ext_host_nat_port,
  			 &s->out2in.addr, s->out2in.port,
  			 &s->ext_host_addr, s->ext_host_port,
  			 s->in2out.protocol, is_twice_nat_session (s));
  
    nat_ha_sadd (&s->in2out.addr, s->in2out.port, &s->out2in.addr,
  	       s->out2in.port, &s->ext_host_addr, s->ext_host_port,
  	       &s->ext_host_nat_addr, s->ext_host_nat_port,
  	       s->in2out.protocol, s->in2out.fib_index, s->flags,
  	       thread_index, 0);
  
    return s;
  }
  
  static int
  next_src_nat (snat_main_t * sm, ip4_header_t * ip, u8 proto, u16 src_port,
  	      u16 dst_port, u32 thread_index, u32 rx_fib_index)
  {
    clib_bihash_kv_16_8_t kv, value;
    snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
  
    make_ed_kv (&kv, &ip->src_address, &ip->dst_address, proto,
  	      rx_fib_index, src_port, dst_port);
    if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
      return 1;
  
    return 0;
  }
  
  static void
  create_bypass_for_fwd (snat_main_t * sm, ip4_header_t * ip, u32 rx_fib_index,
  		       u32 thread_index)
  {
    nat_ed_ses_key_t key;
    clib_bihash_kv_16_8_t kv, value;
    udp_header_t *udp;
    snat_user_t *u;
    snat_session_t *s = 0;
    snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
    f64 now = vlib_time_now (sm->vlib_main);
  
    if (ip->protocol == IP_PROTOCOL_ICMP)
      {
        if (get_icmp_o2i_ed_key (ip, &key))
  	return;
      }
    else if (ip->protocol == IP_PROTOCOL_UDP || ip->protocol == IP_PROTOCOL_TCP)
      {
        udp = ip4_next_header (ip);
        key.r_addr = ip->src_address;
        key.l_addr = ip->dst_address;
        key.proto = ip->protocol;
        key.l_port = udp->dst_port;
        key.r_port = udp->src_port;
      }
    else
      {
        key.r_addr = ip->src_address;
        key.l_addr = ip->dst_address;
        key.proto = ip->protocol;
        key.l_port = key.r_port = 0;
      }
    key.fib_index = 0;
    kv.key[0] = key.as_u64[0];
    kv.key[1] = key.as_u64[1];
  
    if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &kv, &value))
      {
        s = pool_elt_at_index (tsm->sessions, value.value);
      }
    else
      {
        u32 proto;
  
        if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
  	return;
  
        u = nat_user_get_or_create (sm, &ip->dst_address, sm->inside_fib_index,
  				  thread_index);
        if (!u)
  	{
  	  nat_elog_warn ("create NAT user failed");
  	  return;
  	}
  
        s = nat_ed_session_alloc (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;
  	}
  
        proto = ip_proto_to_snat_proto (key.proto);
  
        s->ext_host_addr = key.r_addr;
        s->ext_host_port = key.r_port;
        s->flags |= SNAT_SESSION_FLAG_FWD_BYPASS;
        s->out2in.addr = key.l_addr;
        s->out2in.port = key.l_port;
        s->out2in.protocol = proto;
        if (proto == ~0)
  	{
  	  s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
  	  s->out2in.port = ip->protocol;
  	}
        s->out2in.fib_index = 0;
        s->in2out = s->out2in;
        user_session_increment (sm, u, 0);
  
        kv.value = s - tsm->sessions;
        if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &kv, 1))
  	nat_elog_notice ("in2out_ed key add failed");
      }
  
    if (ip->protocol == IP_PROTOCOL_TCP)
      {
        tcp_header_t *tcp = ip4_next_header (ip);
        if (nat44_set_tcp_session_state_o2i (sm, s, tcp, thread_index))
  	return;
      }
  
    /* Accounting */
    nat44_session_update_counters (s, now, 0, thread_index);
    /* Per-user LRU list maintenance */
    nat44_session_update_lru (sm, s, thread_index);
  }
  
  static inline void
  create_bypass_for_fwd_worker (snat_main_t * sm, ip4_header_t * ip,
  			      u32 rx_fib_index)
  {
    ip4_header_t ip_wkr = {
      .src_address = ip->dst_address,
    };
    u32 thread_index = sm->worker_in2out_cb (&ip_wkr, rx_fib_index, 0);
  
    create_bypass_for_fwd (sm, ip, rx_fib_index, thread_index);
  }
  
  #ifndef CLIB_MARCH_VARIANT
  u32
  icmp_match_out2in_ed (snat_main_t * sm, vlib_node_runtime_t * node,
  		      u32 thread_index, vlib_buffer_t * b, ip4_header_t * ip,
  		      u8 * p_proto, snat_session_key_t * p_value,
  		      u8 * p_dont_translate, void *d, void *e)
  {
    u32 next = ~0, sw_if_index, rx_fib_index;
    icmp46_header_t *icmp;
    nat_ed_ses_key_t key;
    clib_bihash_kv_16_8_t kv, value;
    snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
    snat_session_t *s = 0;
    u8 dont_translate = 0, is_addr_only, identity_nat;
    snat_session_key_t e_key, l_key;
  
    icmp = (icmp46_header_t *) ip4_next_header (ip);
    sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
    rx_fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
  
    if (get_icmp_o2i_ed_key (ip, &key))
      {
        b->error = node->errors[NAT_OUT2IN_ED_ERROR_UNSUPPORTED_PROTOCOL];
        next = NAT_NEXT_DROP;
        goto out;
      }
    key.fib_index = rx_fib_index;
    kv.key[0] = key.as_u64[0];
    kv.key[1] = key.as_u64[1];
  
    if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv, &value))
      {
        /* Try to match static mapping */
        e_key.addr = ip->dst_address;
        e_key.port = key.l_port;
        e_key.protocol = ip_proto_to_snat_proto (key.proto);
        e_key.fib_index = rx_fib_index;
        if (snat_static_mapping_match
  	  (sm, e_key, &l_key, 1, &is_addr_only, 0, 0, 0, &identity_nat))
  	{
  	  if (!sm->forwarding_enabled)
  	    {
  	      /* Don't NAT packet aimed at the intfc address */
  	      if (PREDICT_FALSE (is_interface_addr (sm, node, sw_if_index,
  						    ip->dst_address.as_u32)))
  		{
  		  dont_translate = 1;
  		  goto out;
  		}
  	      b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
  	      next = NAT_NEXT_DROP;
  	      goto out;
  	    }
  	  else
  	    {
  	      dont_translate = 1;
  	      if (next_src_nat (sm, ip, key.proto, key.l_port, key.r_port,
  				thread_index, rx_fib_index))
  		{
  		  next = NAT_NEXT_IN2OUT_ED_FAST_PATH;
  		  goto out;
  		}
  	      if (sm->num_workers > 1)
  		create_bypass_for_fwd_worker (sm, ip, rx_fib_index);
  	      else
  		create_bypass_for_fwd (sm, ip, rx_fib_index, thread_index);
  	      goto out;
  	    }
  	}
  
        if (PREDICT_FALSE (icmp->type != ICMP4_echo_reply &&
  			 (icmp->type != ICMP4_echo_request || !is_addr_only)))
  	{
  	  b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
  	  next = NAT_NEXT_DROP;
  	  goto out;
  	}
  
        if (PREDICT_FALSE (identity_nat))
  	{
  	  dont_translate = 1;
  	  goto out;
  	}
  
        /* Create session initiated by host from external network */
        s = create_session_for_static_mapping_ed (sm, b, l_key, e_key, node,
  						thread_index, 0, 0,
  						vlib_time_now
  						(sm->vlib_main));
  
        if (!s)
  	{
  	  next = NAT_NEXT_DROP;
  	  goto out;
  	}
      }
    else
      {
        if (PREDICT_FALSE (icmp->type != ICMP4_echo_reply &&
  			 icmp->type != ICMP4_echo_request &&
  			 !icmp_is_error_message (icmp)))
  	{
  	  b->error = node->errors[NAT_OUT2IN_ED_ERROR_BAD_ICMP_TYPE];
  	  next = NAT_NEXT_DROP;
  	  goto out;
  	}
  
        s = pool_elt_at_index (tsm->sessions, value.value);
      }
  
    *p_proto = ip_proto_to_snat_proto (key.proto);
  out:
    if (s)
      *p_value = s->in2out;
    *p_dont_translate = dont_translate;
    if (d)
      *(snat_session_t **) d = s;
    return next;
  }
  #endif
  
  static snat_session_t *
  nat44_ed_out2in_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;
    u32 old_addr, new_addr;
    ip_csum_t sum;
    snat_session_t *s;
    snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
    snat_user_t *u;
  
    old_addr = ip->dst_address.as_u32;
  
    make_ed_kv (&s_kv, &ip->dst_address, &ip->src_address, ip->protocol,
  	      rx_fib_index, 0, 0);
  
    if (!clib_bihash_search_16_8 (&tsm->out2in_ed, &s_kv, &s_value))
      {
        s = pool_elt_at_index (tsm->sessions, s_value.value);
        new_addr = ip->dst_address.as_u32 = s->in2out.addr.as_u32;
      }
    else
      {
        if (PREDICT_FALSE (maximum_sessions_exceeded (sm, thread_index)))
  	{
  	  b->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_SESSIONS_EXCEEDED];
  	  nat_elog_notice ("maximum sessions exceeded");
  	  return 0;
  	}
  
        make_sm_kv (&kv, &ip->dst_address, 0, 0, 0);
        if (clib_bihash_search_8_8
  	  (&sm->static_mapping_by_external, &kv, &value))
  	{
  	  b->error = node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
  	  return 0;
  	}
  
        m = pool_elt_at_index (sm->static_mappings, value.value);
  
        new_addr = ip->dst_address.as_u32 = m->local_addr.as_u32;
  
        u = nat_user_get_or_create (sm, &m->local_addr, m->fib_index,
  				  thread_index);
        if (!u)
  	{
  	  nat_elog_warn ("create NAT user failed");
  	  return 0;
  	}
  
        /* Create a new session */
        s = nat_ed_session_alloc (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->ext_host_addr.as_u32 = ip->src_address.as_u32;
        s->flags |= SNAT_SESSION_FLAG_UNKNOWN_PROTO;
        s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING;
        s->flags |= SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT;
        s->out2in.addr.as_u32 = old_addr;
        s->out2in.fib_index = rx_fib_index;
        s->in2out.addr.as_u32 = new_addr;
        s->in2out.fib_index = m->fib_index;
        s->in2out.port = s->out2in.port = ip->protocol;
        user_session_increment (sm, u, 1);
  
        /* Add to lookup tables */
        s_kv.value = s - tsm->sessions;
        if (clib_bihash_add_del_16_8 (&tsm->out2in_ed, &s_kv, 1))
  	nat_elog_notice ("out2in key add failed");
  
        make_ed_kv (&s_kv, &ip->dst_address, &ip->src_address, ip->protocol,
  		  m->fib_index, 0, 0);
        s_kv.value = s - tsm->sessions;
        if (clib_bihash_add_del_16_8 (&tsm->in2out_ed, &s_kv, 1))
  	nat_elog_notice ("in2out key add failed");
      }
  
    /* Update IP checksum */
    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] = s->in2out.fib_index;
  
    /* Accounting */
    nat44_session_update_counters (s, now, vlib_buffer_length_in_chain (vm, b),
  				 thread_index);
    /* Per-user LRU list maintenance */
    nat44_session_update_lru (sm, s, thread_index);
  
    return s;
  }
  
  static inline uword
  nat44_ed_out2in_node_fn_inline (vlib_main_t * vm,
  				vlib_node_runtime_t * node,
  				vlib_frame_t * frame, int is_slow_path)
  {
    u32 n_left_from, *from, *to_next, pkts_processed = 0, stats_node_index;
    nat_next_t next_index;
    snat_main_t *sm = &snat_main;
    f64 now = vlib_time_now (vm);
    u32 thread_index = vm->thread_index;
    snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
    u32 tcp_packets = 0, udp_packets = 0, icmp_packets = 0, other_packets =
      0, fragments = 0;
  
    stats_node_index = is_slow_path ? sm->ed_out2in_slowpath_node_index :
      sm->ed_out2in_node_index;
  
    from = vlib_frame_vector_args (frame);
    n_left_from = frame->n_vectors;
    next_index = node->cached_next_index;
  
    while (n_left_from > 0)
      {
        u32 n_left_to_next;
  
        vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
  
        while (n_left_from >= 4 && n_left_to_next >= 2)
  	{
  	  u32 bi0, bi1;
  	  vlib_buffer_t *b0, *b1;
  	  u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
  	    new_addr0;
  	  u32 next1, sw_if_index1, rx_fib_index1, proto1, old_addr1,
  	    new_addr1;
  	  u16 old_port0, new_port0, old_port1, new_port1;
  	  ip4_header_t *ip0, *ip1;
  	  udp_header_t *udp0, *udp1;
  	  tcp_header_t *tcp0, *tcp1;
  	  icmp46_header_t *icmp0, *icmp1;
  	  snat_session_t *s0 = 0, *s1 = 0;
  	  clib_bihash_kv_16_8_t kv0, value0, kv1, value1;
  	  ip_csum_t sum0, sum1;
  	  snat_session_key_t e_key0, l_key0, e_key1, l_key1;
  	  lb_nat_type_t lb_nat0, lb_nat1;
  	  twice_nat_type_t twice_nat0, twice_nat1;
  	  u8 identity_nat0, identity_nat1;
  
  	  /* Prefetch next iteration. */
  	  {
  	    vlib_buffer_t *p2, *p3;
  
  	    p2 = vlib_get_buffer (vm, from[2]);
  	    p3 = vlib_get_buffer (vm, from[3]);
  
  	    vlib_prefetch_buffer_header (p2, LOAD);
  	    vlib_prefetch_buffer_header (p3, LOAD);
  
  	    CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
  	    CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
  	  }
  
  	  /* speculatively enqueue b0 and b1 to the current next frame */
  	  to_next[0] = bi0 = from[0];
  	  to_next[1] = bi1 = from[1];
  	  from += 2;
  	  to_next += 2;
  	  n_left_from -= 2;
  	  n_left_to_next -= 2;
  
  	  b0 = vlib_get_buffer (vm, bi0);
  	  b1 = vlib_get_buffer (vm, bi1);
  
  	  next0 = nat_buffer_opaque (b0)->arc_next;
  	  next1 = nat_buffer_opaque (b1)->arc_next;
  
  	  vnet_buffer (b0)->snat.flags = 0;
  	  ip0 = vlib_buffer_get_current (b0);
  
  	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
  	  rx_fib_index0 =
  	    fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
  						 sw_if_index0);
  
  	  if (PREDICT_FALSE (ip0->ttl == 1))
  	    {
  	      vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
  	      icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
  					   ICMP4_time_exceeded_ttl_exceeded_in_transit,
  					   0);
  	      next0 = NAT_NEXT_ICMP_ERROR;
  	      goto trace00;
  	    }
  
  	  udp0 = ip4_next_header (ip0);
  	  tcp0 = (tcp_header_t *) udp0;
  	  icmp0 = (icmp46_header_t *) udp0;
  	  proto0 = ip_proto_to_snat_proto (ip0->protocol);
  
  	  if (is_slow_path)
  	    {
  	      if (PREDICT_FALSE (proto0 == ~0))
  		{
  		  s0 =
  		    nat44_ed_out2in_unknown_proto (sm, b0, ip0, rx_fib_index0,
  						   thread_index, now, vm,
  						   node);
  		  other_packets++;
  		  if (!sm->forwarding_enabled)
  		    {
  		      if (!s0)
  			next0 = NAT_NEXT_DROP;
  		      goto trace00;
  		    }
  		}
  
  	      if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
  		{
  		  next0 = icmp_out2in_ed_slow_path
  		    (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
  		     next0, now, thread_index, &s0);
  		  icmp_packets++;
  		  goto trace00;
  		}
  	    }
  	  else
  	    {
  	      if (PREDICT_FALSE (proto0 == ~0))
  		{
  		  next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
  		  goto trace00;
  		}
  
  	      if (ip4_is_fragment (ip0))
  		{
  		  next0 = NAT_NEXT_OUT2IN_ED_REASS;
  		  fragments++;
  		  goto trace00;
  		}
  
  	      if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
  		{
  		  next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
  		  goto trace00;
  		}
  	    }
  
  	  make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
  		      ip0->protocol, rx_fib_index0, udp0->dst_port,
  		      udp0->src_port);
  
  	  if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
  	    {
  	      if (is_slow_path)
  		{
  		  /* Try to match static mapping by external address and port,
  		     destination address and port in packet */
  		  e_key0.addr = ip0->dst_address;
  		  e_key0.port = udp0->dst_port;
  		  e_key0.protocol = proto0;
  		  e_key0.fib_index = rx_fib_index0;
  		  if (snat_static_mapping_match (sm, e_key0, &l_key0, 1, 0,
  						 &twice_nat0, &lb_nat0,
  						 &ip0->src_address,
  						 &identity_nat0))
  		    {
  		      /*
  		       * 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 == SNAT_PROTOCOL_UDP
  					 && (udp0->dst_port ==
  					     clib_host_to_net_u16
  					     (UDP_DST_PORT_dhcp_to_client))))
  			{
  			  goto trace00;
  			}
  
  		      if (!sm->forwarding_enabled)
  			{
  			  b0->error =
  			    node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
  			  next0 = NAT_NEXT_DROP;
  			}
  		      else
  			{
  			  if (next_src_nat (sm, ip0, ip0->protocol,
  					    udp0->src_port, udp0->dst_port,
  					    thread_index, rx_fib_index0))
  			    {
  			      next0 = NAT_NEXT_IN2OUT_ED_FAST_PATH;
  			      goto trace00;
  			    }
  			  if (sm->num_workers > 1)
  			    create_bypass_for_fwd_worker (sm, ip0,
  							  rx_fib_index0);
  			  else
  			    create_bypass_for_fwd (sm, ip0, rx_fib_index0,
  						   thread_index);
  			}
  		      goto trace00;
  		    }
  
  		  if (PREDICT_FALSE (identity_nat0))
  		    goto trace00;
  
  		  if ((proto0 == SNAT_PROTOCOL_TCP) && !tcp_is_init (tcp0))
  		    {
  		      b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
  		      next0 = NAT_NEXT_DROP;
  		      goto trace00;
  		    }
  
  		  /* Create session initiated by host from external network */
  		  s0 = create_session_for_static_mapping_ed (sm, b0, l_key0,
  							     e_key0, node,
  							     thread_index,
  							     twice_nat0,
  							     lb_nat0, now);
  
  		  if (!s0)
  		    {
  		      next0 = NAT_NEXT_DROP;
  		      goto trace00;
  		    }
  		}
  	      else
  		{
  		  next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
  		  goto trace00;
  		}
  	    }
  	  else
  	    {
  	      s0 = pool_elt_at_index (tsm->sessions, value0.value);
  	    }
  
  	  old_addr0 = ip0->dst_address.as_u32;
  	  new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.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);
  	  if (PREDICT_FALSE (is_twice_nat_session (s0)))
  	    sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
  				   s0->ext_host_nat_addr.as_u32, ip4_header_t,
  				   src_address);
  	  ip0->checksum = ip_csum_fold (sum0);
  
  	  old_port0 = udp0->dst_port;
  	  new_port0 = udp0->dst_port = s0->in2out.port;
  
  	  if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
  	    {
  	      sum0 = tcp0->checksum;
  	      sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
  				     dst_address);
  	      sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
  				     length);
  	      if (is_twice_nat_session (s0))
  		{
  		  sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
  					 s0->ext_host_nat_addr.as_u32,
  					 ip4_header_t, dst_address);
  		  sum0 = ip_csum_update (sum0, tcp0->src_port,
  					 s0->ext_host_nat_port, ip4_header_t,
  					 length);
  		  tcp0->src_port = s0->ext_host_nat_port;
  		  ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
  		}
  	      tcp0->checksum = ip_csum_fold (sum0);
  	      tcp_packets++;
  	      if (nat44_set_tcp_session_state_o2i
  		  (sm, s0, tcp0, thread_index))
  		goto trace00;
  	    }
  	  else if (udp0->checksum)
  	    {
  	      sum0 = udp0->checksum;
  	      sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
  				     dst_address);
  	      sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
  				     length);
  	      if (PREDICT_FALSE (is_twice_nat_session (s0)))
  		{
  		  sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
  					 s0->ext_host_nat_addr.as_u32,
  					 ip4_header_t, dst_address);
  		  sum0 = ip_csum_update (sum0, udp0->src_port,
  					 s0->ext_host_nat_port, ip4_header_t,
  					 length);
  		  udp0->src_port = s0->ext_host_nat_port;
  		  ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
  		}
  	      udp0->checksum = ip_csum_fold (sum0);
  	      udp_packets++;
  	    }
  	  else
  	    {
  	      if (PREDICT_FALSE (is_twice_nat_session (s0)))
  		{
  		  udp0->src_port = s0->ext_host_nat_port;
  		  ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
  		}
  	      udp_packets++;
  	    }
  
  	  /* 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)))
  	    {
  	      nat44_ed_out2in_trace_t *t =
  		vlib_add_trace (vm, node, b0, sizeof (*t));
  	      t->is_slow_path = is_slow_path;
  	      t->sw_if_index = sw_if_index0;
  	      t->next_index = next0;
  	      t->session_index = ~0;
  	      if (s0)
  		t->session_index = s0 - tsm->sessions;
  	    }
  
  	  pkts_processed += next0 == nat_buffer_opaque (b0)->arc_next;
  
  	  vnet_buffer (b1)->snat.flags = 0;
  	  ip1 = vlib_buffer_get_current (b1);
  
  	  sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
  	  rx_fib_index1 =
  	    fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
  						 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 = NAT_NEXT_ICMP_ERROR;
  	      goto trace01;
  	    }
  
  	  udp1 = ip4_next_header (ip1);
  	  tcp1 = (tcp_header_t *) udp1;
  	  icmp1 = (icmp46_header_t *) udp1;
  	  proto1 = ip_proto_to_snat_proto (ip1->protocol);
  
  	  if (is_slow_path)
  	    {
  	      if (PREDICT_FALSE (proto1 == ~0))
  		{
  		  s1 =
  		    nat44_ed_out2in_unknown_proto (sm, b1, ip1, rx_fib_index1,
  						   thread_index, now, vm,
  						   node);
  		  other_packets++;
  		  if (!sm->forwarding_enabled)
  		    {
  		      if (!s1)
  			next1 = NAT_NEXT_DROP;
  		      goto trace01;
  		    }
  		}
  
  	      if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
  		{
  		  next1 = icmp_out2in_ed_slow_path
  		    (sm, b1, ip1, icmp1, sw_if_index1, rx_fib_index1, node,
  		     next1, now, thread_index, &s1);
  		  icmp_packets++;
  		  goto trace01;
  		}
  	    }
  	  else
  	    {
  	      if (PREDICT_FALSE (proto1 == ~0))
  		{
  		  next1 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
  		  goto trace01;
  		}
  
  	      if (ip4_is_fragment (ip1))
  		{
  		  next1 = NAT_NEXT_OUT2IN_ED_REASS;
  		  fragments++;
  		  goto trace01;
  		}
  
  	      if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP))
  		{
  		  next1 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
  		  goto trace01;
  		}
  	    }
  
  	  make_ed_kv (&kv1, &ip1->dst_address, &ip1->src_address,
  		      ip1->protocol, rx_fib_index1, udp1->dst_port,
  		      udp1->src_port);
  
  	  if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv1, &value1))
  	    {
  	      if (is_slow_path)
  		{
  		  /* Try to match static mapping by external address and port,
  		     destination address and port in packet */
  		  e_key1.addr = ip1->dst_address;
  		  e_key1.port = udp1->dst_port;
  		  e_key1.protocol = proto1;
  		  e_key1.fib_index = rx_fib_index1;
  		  if (snat_static_mapping_match (sm, e_key1, &l_key1, 1, 0,
  						 &twice_nat1, &lb_nat1,
  						 &ip1->src_address,
  						 &identity_nat1))
  		    {
  		      /*
  		       * 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 == SNAT_PROTOCOL_UDP
  					 && (udp1->dst_port ==
  					     clib_host_to_net_u16
  					     (UDP_DST_PORT_dhcp_to_client))))
  			{
  			  goto trace01;
  			}
  
  		      if (!sm->forwarding_enabled)
  			{
  			  b1->error =
  			    node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
  			  next1 = NAT_NEXT_DROP;
  			}
  		      else
  			{
  			  if (next_src_nat (sm, ip1, ip1->protocol,
  					    udp1->src_port, udp1->dst_port,
  					    thread_index, rx_fib_index1))
  			    {
  			      next1 = NAT_NEXT_IN2OUT_ED_FAST_PATH;
  			      goto trace01;
  			    }
  			  if (sm->num_workers > 1)
  			    create_bypass_for_fwd_worker (sm, ip1,
  							  rx_fib_index1);
  			  else
  			    create_bypass_for_fwd (sm, ip1, rx_fib_index1,
  						   thread_index);
  			}
  		      goto trace01;
  		    }
  
  		  if (PREDICT_FALSE (identity_nat1))
  		    goto trace01;
  
  		  if ((proto1 == SNAT_PROTOCOL_TCP) && !tcp_is_init (tcp1))
  		    {
  		      b1->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
  		      next1 = NAT_NEXT_DROP;
  		      goto trace01;
  		    }
  
  		  /* Create session initiated by host from external network */
  		  s1 = create_session_for_static_mapping_ed (sm, b1, l_key1,
  							     e_key1, node,
  							     thread_index,
  							     twice_nat1,
  							     lb_nat1, now);
  
  		  if (!s1)
  		    {
  		      next1 = NAT_NEXT_DROP;
  		      goto trace01;
  		    }
  		}
  	      else
  		{
  		  next1 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
  		  goto trace01;
  		}
  	    }
  	  else
  	    {
  	      s1 = pool_elt_at_index (tsm->sessions, value1.value);
  	    }
  
  	  old_addr1 = ip1->dst_address.as_u32;
  	  new_addr1 = ip1->dst_address.as_u32 = s1->in2out.addr.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);
  	  if (PREDICT_FALSE (is_twice_nat_session (s1)))
  	    sum1 = ip_csum_update (sum1, ip1->src_address.as_u32,
  				   s1->ext_host_nat_addr.as_u32, ip4_header_t,
  				   src_address);
  	  ip1->checksum = ip_csum_fold (sum1);
  
  	  old_port1 = udp1->dst_port;
  	  new_port1 = udp1->dst_port = s1->in2out.port;
  
  	  if (PREDICT_TRUE (proto1 == SNAT_PROTOCOL_TCP))
  	    {
  	      sum1 = tcp1->checksum;
  	      sum1 = ip_csum_update (sum1, old_addr1, new_addr1, ip4_header_t,
  				     dst_address);
  	      sum1 = ip_csum_update (sum1, old_port1, new_port1, ip4_header_t,
  				     length);
  	      if (is_twice_nat_session (s1))
  		{
  		  sum1 = ip_csum_update (sum1, ip1->src_address.as_u32,
  					 s1->ext_host_nat_addr.as_u32,
  					 ip4_header_t, dst_address);
  		  sum1 = ip_csum_update (sum1, tcp1->src_port,
  					 s1->ext_host_nat_port, ip4_header_t,
  					 length);
  		  tcp1->src_port = s1->ext_host_nat_port;
  		  ip1->src_address.as_u32 = s1->ext_host_nat_addr.as_u32;
  		}
  	      tcp1->checksum = ip_csum_fold (sum1);
  	      tcp_packets++;
  	      if (nat44_set_tcp_session_state_o2i
  		  (sm, s1, tcp1, thread_index))
  		goto trace01;
  	    }
  	  else if (udp1->checksum)
  	    {
  	      sum1 = udp1->checksum;
  	      sum1 = ip_csum_update (sum1, old_addr1, new_addr1, ip4_header_t,
  				     dst_address);
  	      sum1 = ip_csum_update (sum1, old_port1, new_port1, ip4_header_t,
  				     length);
  	      if (PREDICT_FALSE (is_twice_nat_session (s1)))
  		{
  		  sum1 = ip_csum_update (sum1, ip1->src_address.as_u32,
  					 s1->ext_host_nat_addr.as_u32,
  					 ip4_header_t, dst_address);
  		  sum1 = ip_csum_update (sum1, udp1->src_port,
  					 s1->ext_host_nat_port, ip4_header_t,
  					 length);
  		  udp1->src_port = s1->ext_host_nat_port;
  		  ip1->src_address.as_u32 = s1->ext_host_nat_addr.as_u32;
  		}
  	      udp1->checksum = ip_csum_fold (sum1);
  	      udp_packets++;
  	    }
  	  else
  	    {
  	      if (PREDICT_FALSE (is_twice_nat_session (s1)))
  		{
  		  udp1->src_port = s1->ext_host_nat_port;
  		  ip1->src_address.as_u32 = s1->ext_host_nat_addr.as_u32;
  		}
  	      udp_packets++;
  	    }
  
  	  /* 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);
  
  	trace01:
  	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
  			     && (b1->flags & VLIB_BUFFER_IS_TRACED)))
  	    {
  	      nat44_ed_out2in_trace_t *t =
  		vlib_add_trace (vm, node, b1, sizeof (*t));
  	      t->is_slow_path = is_slow_path;
  	      t->sw_if_index = sw_if_index1;
  	      t->next_index = next1;
  	      t->session_index = ~0;
  	      if (s1)
  		t->session_index = s1 - tsm->sessions;
  	    }
  
  	  pkts_processed += next1 == nat_buffer_opaque (b1)->arc_next;
  
  	  /* verify speculative enqueues, maybe switch current next frame */
  	  vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
  					   to_next, n_left_to_next,
  					   bi0, bi1, next0, next1);
  	}
  
        while (n_left_from > 0 && n_left_to_next > 0)
  	{
  	  u32 bi0;
  	  vlib_buffer_t *b0;
  	  u32 next0, sw_if_index0, rx_fib_index0, proto0, old_addr0,
  	    new_addr0;
  	  u16 old_port0, new_port0;
  	  ip4_header_t *ip0;
  	  udp_header_t *udp0;
  	  tcp_header_t *tcp0;
  	  icmp46_header_t *icmp0;
  	  snat_session_t *s0 = 0;
  	  clib_bihash_kv_16_8_t kv0, value0;
  	  ip_csum_t sum0;
  	  snat_session_key_t e_key0, l_key0;
  	  lb_nat_type_t lb_nat0;
  	  twice_nat_type_t twice_nat0;
  	  u8 identity_nat0;
  
  	  /* speculatively enqueue b0 to the current next frame */
  	  bi0 = from[0];
  	  to_next[0] = bi0;
  	  from += 1;
  	  to_next += 1;
  	  n_left_from -= 1;
  	  n_left_to_next -= 1;
  
  	  b0 = vlib_get_buffer (vm, bi0);
  	  next0 = nat_buffer_opaque (b0)->arc_next;
  
  	  vnet_buffer (b0)->snat.flags = 0;
  	  ip0 = vlib_buffer_get_current (b0);
  
  	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
  	  rx_fib_index0 =
  	    fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
  						 sw_if_index0);
  
  	  if (PREDICT_FALSE (ip0->ttl == 1))
  	    {
  	      vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
  	      icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
  					   ICMP4_time_exceeded_ttl_exceeded_in_transit,
  					   0);
  	      next0 = NAT_NEXT_ICMP_ERROR;
  	      goto trace0;
  	    }
  
  	  udp0 = ip4_next_header (ip0);
  	  tcp0 = (tcp_header_t *) udp0;
  	  icmp0 = (icmp46_header_t *) udp0;
  	  proto0 = ip_proto_to_snat_proto (ip0->protocol);
  
  	  if (is_slow_path)
  	    {
  	      if (PREDICT_FALSE (proto0 == ~0))
  		{
  		  s0 =
  		    nat44_ed_out2in_unknown_proto (sm, b0, ip0, rx_fib_index0,
  						   thread_index, now, vm,
  						   node);
  		  other_packets++;
  		  if (!sm->forwarding_enabled)
  		    {
  		      if (!s0)
  			next0 = NAT_NEXT_DROP;
  		      goto trace0;
  		    }
  		}
  
  	      if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
  		{
  		  next0 = icmp_out2in_ed_slow_path
  		    (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
  		     next0, now, thread_index, &s0);
  		  icmp_packets++;
  		  goto trace0;
  		}
  	    }
  	  else
  	    {
  	      if (PREDICT_FALSE (proto0 == ~0))
  		{
  		  next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
  		  goto trace0;
  		}
  
  	      if (ip4_is_fragment (ip0))
  		{
  		  next0 = NAT_NEXT_OUT2IN_ED_REASS;
  		  fragments++;
  		  goto trace0;
  		}
  
  	      if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
  		{
  		  next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
  		  goto trace0;
  		}
  	    }
  
  	  make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
  		      ip0->protocol, rx_fib_index0, udp0->dst_port,
  		      udp0->src_port);
  
  	  if (clib_bihash_search_16_8 (&tsm->out2in_ed, &kv0, &value0))
  	    {
  	      if (is_slow_path)
  		{
  		  /* Try to match static mapping by external address and port,
  		     destination address and port in packet */
  		  e_key0.addr = ip0->dst_address;
  		  e_key0.port = udp0->dst_port;
  		  e_key0.protocol = proto0;
  		  e_key0.fib_index = rx_fib_index0;
  		  if (snat_static_mapping_match (sm, e_key0, &l_key0, 1, 0,
  						 &twice_nat0, &lb_nat0,
  						 &ip0->src_address,
  						 &identity_nat0))
  		    {
  		      /*
  		       * 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 == SNAT_PROTOCOL_UDP
  					 && (udp0->dst_port ==
  					     clib_host_to_net_u16
  					     (UDP_DST_PORT_dhcp_to_client))))
  			{
  			  goto trace0;
  			}
  
  		      if (!sm->forwarding_enabled)
  			{
  			  b0->error =
  			    node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
  			  next0 = NAT_NEXT_DROP;
  			}
  		      else
  			{
  			  if (next_src_nat (sm, ip0, ip0->protocol,
  					    udp0->src_port, udp0->dst_port,
  					    thread_index, rx_fib_index0))
  			    {
  			      next0 = NAT_NEXT_IN2OUT_ED_FAST_PATH;
  			      goto trace0;
  			    }
  			  if (sm->num_workers > 1)
  			    create_bypass_for_fwd_worker (sm, ip0,
  							  rx_fib_index0);
  			  else
  			    create_bypass_for_fwd (sm, ip0, rx_fib_index0,
  						   thread_index);
  			}
  		      goto trace0;
  		    }
  
  		  if (PREDICT_FALSE (identity_nat0))
  		    goto trace0;
  
  		  if ((proto0 == SNAT_PROTOCOL_TCP) && !tcp_is_init (tcp0))
  		    {
  		      b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
  		      next0 = NAT_NEXT_DROP;
  		      goto trace0;
  		    }
  
  		  /* Create session initiated by host from external network */
  		  s0 = create_session_for_static_mapping_ed (sm, b0, l_key0,
  							     e_key0, node,
  							     thread_index,
  							     twice_nat0,
  							     lb_nat0, now);
  
  		  if (!s0)
  		    {
  		      next0 = NAT_NEXT_DROP;
  		      goto trace0;
  		    }
  		}
  	      else
  		{
  		  next0 = NAT_NEXT_OUT2IN_ED_SLOW_PATH;
  		  goto trace0;
  		}
  	    }
  	  else
  	    {
  	      s0 = pool_elt_at_index (tsm->sessions, value0.value);
  	    }
  
  	  old_addr0 = ip0->dst_address.as_u32;
  	  new_addr0 = ip0->dst_address.as_u32 = s0->in2out.addr.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);
  	  if (PREDICT_FALSE (is_twice_nat_session (s0)))
  	    sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
  				   s0->ext_host_nat_addr.as_u32, ip4_header_t,
  				   src_address);
  	  ip0->checksum = ip_csum_fold (sum0);
  
  	  old_port0 = udp0->dst_port;
  	  new_port0 = udp0->dst_port = s0->in2out.port;
  
  	  if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
  	    {
  	      sum0 = tcp0->checksum;
  	      sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
  				     dst_address);
  	      sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
  				     length);
  	      if (is_twice_nat_session (s0))
  		{
  		  sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
  					 s0->ext_host_nat_addr.as_u32,
  					 ip4_header_t, dst_address);
  		  sum0 = ip_csum_update (sum0, tcp0->src_port,
  					 s0->ext_host_nat_port, ip4_header_t,
  					 length);
  		  tcp0->src_port = s0->ext_host_nat_port;
  		  ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
  		}
  	      tcp0->checksum = ip_csum_fold (sum0);
  	      tcp_packets++;
  	      if (nat44_set_tcp_session_state_o2i
  		  (sm, s0, tcp0, thread_index))
  		goto trace0;
  	    }
  	  else if (udp0->checksum)
  	    {
  	      sum0 = udp0->checksum;
  	      sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
  				     dst_address);
  	      sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
  				     length);
  	      if (PREDICT_FALSE (is_twice_nat_session (s0)))
  		{
  		  sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
  					 s0->ext_host_nat_addr.as_u32,
  					 ip4_header_t, dst_address);
  		  sum0 = ip_csum_update (sum0, udp0->src_port,
  					 s0->ext_host_nat_port, ip4_header_t,
  					 length);
  		  udp0->src_port = s0->ext_host_nat_port;
  		  ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
  		}
  	      udp0->checksum = ip_csum_fold (sum0);
  	      udp_packets++;
  	    }
  	  else
  	    {
  	      if (PREDICT_FALSE (is_twice_nat_session (s0)))
  		{
  		  udp0->src_port = s0->ext_host_nat_port;
  		  ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
  		}
  	      udp_packets++;
  	    }
  
  	  /* Accounting */
  	  nat44_session_update_counters (s0, now,
  					 vlib_buffer_length_in_chain (vm, b0),
  					 thread_index);
  	  /* Per-user LRU list maintenance */
  	  nat44_session_update_lru (sm, s0, thread_index);
  
  	trace0:
  	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
  			     && (b0->flags & VLIB_BUFFER_IS_TRACED)))
  	    {
  	      nat44_ed_out2in_trace_t *t =
  		vlib_add_trace (vm, node, b0, sizeof (*t));
  	      t->is_slow_path = is_slow_path;
  	      t->sw_if_index = sw_if_index0;
  	      t->next_index = next0;
  	      t->session_index = ~0;
  	      if (s0)
  		t->session_index = s0 - tsm->sessions;
  	    }
  
  	  pkts_processed += next0 == nat_buffer_opaque (b0)->arc_next;
  	  /* verify speculative enqueue, maybe switch current next frame */
  	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
  					   to_next, n_left_to_next,
  					   bi0, next0);
  	}
  
        vlib_put_next_frame (vm, node, next_index, n_left_to_next);
      }
  
    vlib_node_increment_counter (vm, stats_node_index,
  			       NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
  			       pkts_processed);
    vlib_node_increment_counter (vm, stats_node_index,
  			       NAT_OUT2IN_ED_ERROR_TCP_PACKETS, tcp_packets);
    vlib_node_increment_counter (vm, stats_node_index,
  			       NAT_OUT2IN_ED_ERROR_UDP_PACKETS, udp_packets);
    vlib_node_increment_counter (vm, stats_node_index,
  			       NAT_OUT2IN_ED_ERROR_ICMP_PACKETS,
  			       icmp_packets);
    vlib_node_increment_counter (vm, stats_node_index,
  			       NAT_OUT2IN_ED_ERROR_OTHER_PACKETS,
  			       other_packets);
    vlib_node_increment_counter (vm, stats_node_index,
  			       NAT_OUT2IN_ED_ERROR_FRAGMENTS, fragments);
    return frame->n_vectors;
  }
  
  static inline uword
  nat44_ed_out2in_reass_node_fn_inline (vlib_main_t * vm,
  				      vlib_node_runtime_t * node,
  				      vlib_frame_t * frame)
  {
    u32 n_left_from, *from, *to_next;
    nat_next_t next_index;
    u32 pkts_processed = 0;
    snat_main_t *sm = &snat_main;
    f64 now = vlib_time_now (vm);
    u32 thread_index = vm->thread_index;
    snat_main_per_thread_data_t *per_thread_data =
      &sm->per_thread_data[thread_index];
    u32 *fragments_to_drop = 0;
    u32 *fragments_to_loopback = 0;
  
    from = vlib_frame_vector_args (frame);
    n_left_from = frame->n_vectors;
    next_index = node->cached_next_index;
  
    while (n_left_from > 0)
      {
        u32 n_left_to_next;
  
        vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
  
        while (n_left_from > 0 && n_left_to_next > 0)
  	{
  	  u32 bi0, sw_if_index0, proto0, rx_fib_index0, new_addr0, old_addr0;
  	  vlib_buffer_t *b0;
  	  u32 next0;
  	  u8 cached0 = 0;
  	  ip4_header_t *ip0;
  	  nat_reass_ip4_t *reass0;
  	  udp_header_t *udp0;
  	  tcp_header_t *tcp0;
  	  icmp46_header_t *icmp0;
  	  clib_bihash_kv_16_8_t kv0, value0;
  	  snat_session_t *s0 = 0;
  	  u16 old_port0, new_port0;
  	  ip_csum_t sum0;
  	  snat_session_key_t e_key0, l_key0;
  	  lb_nat_type_t lb0;
  	  twice_nat_type_t twice_nat0;
  	  u8 identity_nat0;
  
  	  /* speculatively enqueue b0 to the current next frame */
  	  bi0 = from[0];
  	  to_next[0] = bi0;
  	  from += 1;
  	  to_next += 1;
  	  n_left_from -= 1;
  	  n_left_to_next -= 1;
  
  	  b0 = vlib_get_buffer (vm, bi0);
  	  next0 = nat_buffer_opaque (b0)->arc_next;
  
  	  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 (nat_reass_is_drop_frag (0)))
  	    {
  	      next0 = NAT_NEXT_DROP;
  	      b0->error = node->errors[NAT_OUT2IN_ED_ERROR_DROP_FRAGMENT];
  	      goto trace0;
  	    }
  
  	  ip0 = (ip4_header_t *) vlib_buffer_get_current (b0);
  	  udp0 = ip4_next_header (ip0);
  	  tcp0 = (tcp_header_t *) udp0;
  	  icmp0 = (icmp46_header_t *) udp0;
  	  proto0 = ip_proto_to_snat_proto (ip0->protocol);
  
  	  reass0 = nat_ip4_reass_find_or_create (ip0->src_address,
  						 ip0->dst_address,
  						 ip0->fragment_id,
  						 ip0->protocol,
  						 1, &fragments_to_drop);
  
  	  if (PREDICT_FALSE (!reass0))
  	    {
  	      next0 = NAT_NEXT_DROP;
  	      b0->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_REASS];
  	      nat_elog_notice ("maximum reassemblies exceeded");
  	      goto trace0;
  	    }
  
  	  if (PREDICT_FALSE (ip4_is_first_fragment (ip0)))
  	    {
  	      if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
  		{
  		  next0 = icmp_out2in_ed_slow_path
  		    (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node,
  		     next0, now, thread_index, &s0);
  
  		  if (PREDICT_TRUE (next0 != NAT_NEXT_DROP))
  		    {
  		      if (s0)
  			reass0->sess_index = s0 - per_thread_data->sessions;
  		      else
  			reass0->flags |= NAT_REASS_FLAG_ED_DONT_TRANSLATE;
  		      reass0->thread_index = thread_index;
  		      nat_ip4_reass_get_frags (reass0,
  					       &fragments_to_loopback);
  		    }
  
  		  goto trace0;
  		}
  
  	      make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address,
  			  ip0->protocol, rx_fib_index0, udp0->dst_port,
  			  udp0->src_port);
  
  	      if (clib_bihash_search_16_8
  		  (&per_thread_data->out2in_ed, &kv0, &value0))
  		{
  		  /* Try to match static mapping by external address and port,
  		     destination address and port in packet */
  		  e_key0.addr = ip0->dst_address;
  		  e_key0.port = udp0->dst_port;
  		  e_key0.protocol = proto0;
  		  e_key0.fib_index = rx_fib_index0;
  		  if (snat_static_mapping_match (sm, e_key0, &l_key0, 1, 0,
  						 &twice_nat0, &lb0, 0,
  						 &identity_nat0))
  		    {
  		      /*
  		       * 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 == SNAT_PROTOCOL_UDP
  					 && (udp0->dst_port
  					     ==
  					     clib_host_to_net_u16
  					     (UDP_DST_PORT_dhcp_to_client))))
  			{
  			  goto trace0;
  			}
  
  		      if (!sm->forwarding_enabled)
  			{
  			  b0->error =
  			    node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
  			  next0 = NAT_NEXT_DROP;
  			}
  		      else
  			{
  			  if (next_src_nat (sm, ip0, ip0->protocol,
  					    udp0->src_port, udp0->dst_port,
  					    thread_index, rx_fib_index0))
  			    {
  			      next0 = NAT_NEXT_IN2OUT_ED_FAST_PATH;
  			      goto trace0;
  			    }
  			  if (sm->num_workers > 1)
  			    create_bypass_for_fwd_worker (sm, ip0,
  							  rx_fib_index0);
  			  else
  			    create_bypass_for_fwd (sm, ip0, rx_fib_index0,
  						   thread_index);
  			  reass0->flags |= NAT_REASS_FLAG_ED_DONT_TRANSLATE;
  			  nat_ip4_reass_get_frags (reass0,
  						   &fragments_to_loopback);
  			}
  		      goto trace0;
  		    }
  
  		  if (PREDICT_FALSE (identity_nat0))
  		    {
  		      reass0->flags |= NAT_REASS_FLAG_ED_DONT_TRANSLATE;
  		      goto trace0;
  		    }
  
  		  if ((proto0 == SNAT_PROTOCOL_TCP) && !tcp_is_init (tcp0))
  		    {
  		      b0->error = node->errors[NAT_OUT2IN_ED_ERROR_NON_SYN];
  		      next0 = NAT_NEXT_DROP;
  		      goto trace0;
  		    }
  
  		  /* Create session initiated by host from external network */
  		  s0 = create_session_for_static_mapping_ed (sm, b0, l_key0,
  							     e_key0, node,
  							     thread_index,
  							     twice_nat0, lb0,
  							     now);
  		  if (!s0)
  		    {
  		      b0->error =
  			node->errors[NAT_OUT2IN_ED_ERROR_NO_TRANSLATION];
  		      next0 = NAT_NEXT_DROP;
  		      goto trace0;
  		    }
  		  reass0->sess_index = s0 - per_thread_data->sessions;
  		  reass0->thread_index = thread_index;
  		}
  	      else
  		{
  		  s0 = pool_elt_at_index (per_thread_data->sessions,
  					  value0.value);
  		  reass0->sess_index = value0.value;
  		}
  	      nat_ip4_reass_get_frags (reass0, &fragments_to_loopback);
  	    }
  	  else
  	    {
  	      if (reass0->flags & NAT_REASS_FLAG_ED_DONT_TRANSLATE)
  		goto trace0;
  	      if (PREDICT_FALSE (reass0->sess_index == (u32) ~ 0))
  		{
  		  if (nat_ip4_reass_add_fragment
  		      (thread_index, reass0, bi0, &fragments_to_drop))
  		    {
  		      b0->error = node->errors[NAT_OUT2IN_ED_ERROR_MAX_FRAG];
  		      nat_elog_notice
  			("maximum fragments per reassembly exceeded");
  		      next0 = NAT_NEXT_DROP;
  		      goto trace0;
  		    }
  		  cached0 = 1;
  		  goto trace0;
  		}
  	      s0 = pool_elt_at_index (per_thread_data->sessions,
  				      reass0->sess_index);
  	    }
  
  	  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 */ );
  	  if (PREDICT_FALSE (is_twice_nat_session (s0)))
  	    sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
  				   s0->ext_host_nat_addr.as_u32, ip4_header_t,
  				   src_address);
  	  ip0->checksum = ip_csum_fold (sum0);
  
  	  if (PREDICT_FALSE (ip4_is_first_fragment (ip0)))
  	    {
  	      old_port0 = udp0->dst_port;
  	      new_port0 = udp0->dst_port = s0->in2out.port;
  
  	      if (PREDICT_TRUE (proto0 == SNAT_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 */ );
  		  if (is_twice_nat_session (s0))
  		    {
  		      sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
  					     s0->ext_host_nat_addr.as_u32,
  					     ip4_header_t, dst_address);
  		      sum0 = ip_csum_update (sum0, tcp0->src_port,
  					     s0->ext_host_nat_port,
  					     ip4_header_t, length);
  		      tcp0->src_port = s0->ext_host_nat_port;
  		      ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
  		    }
  		  tcp0->checksum = ip_csum_fold (sum0);
  		}
  	      else if (udp0->checksum)
  		{
  		  sum0 = udp0->checksum;
  		  sum0 =
  		    ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
  				    dst_address);
  		  sum0 =
  		    ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
  				    length);
  		  if (PREDICT_FALSE (is_twice_nat_session (s0)))
  		    {
  		      sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
  					     s0->ext_host_nat_addr.as_u32,
  					     ip4_header_t, dst_address);
  		      sum0 = ip_csum_update (sum0, udp0->src_port,
  					     s0->ext_host_nat_port,
  					     ip4_header_t, length);
  		      udp0->src_port = s0->ext_host_nat_port;
  		      ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
  		    }
  		  udp0->checksum = ip_csum_fold (sum0);
  		}
  	      else
  		{
  		  if (PREDICT_FALSE (is_twice_nat_session (s0)))
  		    {
  		      udp0->src_port = s0->ext_host_nat_port;
  		      ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
  		    }
  		}
  	    }
  
  	  /* Accounting */
  	  nat44_session_update_counters (s0, now,
  					 vlib_buffer_length_in_chain (vm, b0),
  					 thread_index);
  	  /* Per-user LRU list maintenance */
  	  nat44_session_update_lru (sm, s0, thread_index);
  
  	trace0:
  	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
  			     && (b0->flags & VLIB_BUFFER_IS_TRACED)))
  	    {
  	      nat44_reass_trace_t *t =
  		vlib_add_trace (vm, node, b0, sizeof (*t));
  	      t->cached = cached0;
  	      t->sw_if_index = sw_if_index0;
  	      t->next_index = next0;
  	    }
  
  	  if (cached0)
  	    {
  	      n_left_to_next++;
  	      to_next--;
  	    }
  	  else
  	    {
  	      pkts_processed += next0 != NAT_NEXT_DROP;
  
  	      /* verify speculative enqueue, maybe switch current next frame */
  	      vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
  					       to_next, n_left_to_next,
  					       bi0, next0);
  	    }
  
  	  if (n_left_from == 0 && vec_len (fragments_to_loopback))
  	    {
  	      from = vlib_frame_vector_args (frame);
  	      u32 len = vec_len (fragments_to_loopback);
  	      if (len <= VLIB_FRAME_SIZE)
  		{
  		  clib_memcpy_fast (from, fragments_to_loopback,
  				    sizeof (u32) * len);
  		  n_left_from = len;
  		  vec_reset_length (fragments_to_loopback);
  		}
  	      else
  		{
  		  clib_memcpy_fast (from, fragments_to_loopback +
  				    (len - VLIB_FRAME_SIZE),
  				    sizeof (u32) * VLIB_FRAME_SIZE);
  		  n_left_from = VLIB_FRAME_SIZE;
  		  _vec_len (fragments_to_loopback) = len - VLIB_FRAME_SIZE;
  		}
  	    }
  	}
  
        vlib_put_next_frame (vm, node, next_index, n_left_to_next);
      }
  
    vlib_node_increment_counter (vm, sm->ed_out2in_reass_node_index,
  			       NAT_OUT2IN_ED_ERROR_OUT2IN_PACKETS,
  			       pkts_processed);
  
    nat_send_all_to_node (vm, fragments_to_drop, node,
  			&node->errors[NAT_OUT2IN_ED_ERROR_DROP_FRAGMENT],
  			NAT_NEXT_DROP);
  
    vec_free (fragments_to_drop);
    vec_free (fragments_to_loopback);
    return frame->n_vectors;
  }
  
  VLIB_NODE_FN (nat44_ed_out2in_node) (vlib_main_t * vm,
  				     vlib_node_runtime_t * node,
  				     vlib_frame_t * frame)
  {
    return nat44_ed_out2in_node_fn_inline (vm, node, frame, 0);
  }
  
  /* *INDENT-OFF* */
  VLIB_REGISTER_NODE (nat44_ed_out2in_node) = {
    .name = "nat44-ed-out2in",
    .vector_size = sizeof (u32),
    .sibling_of = "nat-default",
    .format_trace = format_nat44_ed_out2in_trace,
    .type = VLIB_NODE_TYPE_INTERNAL,
    .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
    .error_strings = nat_out2in_ed_error_strings,
    .runtime_data_bytes = sizeof (snat_runtime_t),
  };
  /* *INDENT-ON* */
  
  VLIB_NODE_FN (nat44_ed_out2in_slowpath_node) (vlib_main_t * vm,
  					      vlib_node_runtime_t * node,
  					      vlib_frame_t * frame)
  {
    return nat44_ed_out2in_node_fn_inline (vm, node, frame, 1);
  }
  
  /* *INDENT-OFF* */
  VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = {
    .name = "nat44-ed-out2in-slowpath",
    .vector_size = sizeof (u32),
    .sibling_of = "nat-default",
    .format_trace = format_nat44_ed_out2in_trace,
    .type = VLIB_NODE_TYPE_INTERNAL,
    .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
    .error_strings = nat_out2in_ed_error_strings,
    .runtime_data_bytes = sizeof (snat_runtime_t),
  };
  /* *INDENT-ON* */
  
  VLIB_NODE_FN (nat44_ed_out2in_reass_node) (vlib_main_t * vm,
  					   vlib_node_runtime_t * node,
  					   vlib_frame_t * frame)
  {
    return nat44_ed_out2in_reass_node_fn_inline (vm, node, frame);
  }
  
  /* *INDENT-OFF* */
  VLIB_REGISTER_NODE (nat44_ed_out2in_reass_node) = {
    .name = "nat44-ed-out2in-reass",
    .vector_size = sizeof (u32),
    .sibling_of = "nat-default",
    .format_trace = format_nat44_reass_trace,
    .type = VLIB_NODE_TYPE_INTERNAL,
    .n_errors = ARRAY_LEN(nat_out2in_ed_error_strings),
    .error_strings = nat_out2in_ed_error_strings,
  };
  /* *INDENT-ON* */
  
  static u8 *
  format_nat_pre_trace (u8 * s, va_list * args)
  {
    CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
    CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
    nat_pre_trace_t *t = va_arg (*args, nat_pre_trace_t *);
    return format (s, "out2in next_index %d", t->next_index);
  }
  
  VLIB_NODE_FN (nat_pre_out2in_node) (vlib_main_t * vm,
  				    vlib_node_runtime_t * node,
  				    vlib_frame_t * frame)
  {
    return nat_pre_node_fn_inline (vm, node, frame,
  				 NAT_NEXT_OUT2IN_ED_FAST_PATH);
  }
  
  /* *INDENT-OFF* */
  VLIB_REGISTER_NODE (nat_pre_out2in_node) = {
    .name = "nat-pre-out2in",
    .vector_size = sizeof (u32),
    .sibling_of = "nat-default",
    .format_trace = format_nat_pre_trace,
    .type = VLIB_NODE_TYPE_INTERNAL,
    .n_errors = 0,
   };
  /* *INDENT-ON* */
  
  /*
   * fd.io coding-style-patch-verification: ON
   *
   * Local Variables:
   * eval: (c-set-style "gnu")
   * End:
   */
  