text: /*
   * snat.c - simple nat plugin
   *
   * 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.
   */
  
  #include <vnet/vnet.h>
  #include <vnet/ip/ip.h>
  #include <vnet/ip/ip4.h>
  #include <vnet/plugin/plugin.h>
  #include <nat/nat.h>
  #include <nat/nat_dpo.h>
  #include <nat/nat_ipfix_logging.h>
  #include <nat/nat_det.h>
  #include <nat/nat64.h>
  #include <nat/nat66.h>
  #include <nat/dslite.h>
  #include <nat/nat_reass.h>
  #include <nat/nat_inlines.h>
  #include <nat/nat_affinity.h>
  #include <vnet/fib/fib_table.h>
  #include <vnet/fib/ip4_fib.h>
  
  #include <vpp/app/version.h>
  
  snat_main_t snat_main;
  
  /* *INDENT-OFF* */
  
  /* Hook up input features */
  VNET_FEATURE_INIT (ip4_snat_in2out, static) = {
    .arc_name = "ip4-unicast",
    .node_name = "nat44-in2out",
    .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa"),
  };
  VNET_FEATURE_INIT (ip4_snat_out2in, static) = {
    .arc_name = "ip4-unicast",
    .node_name = "nat44-out2in",
    .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa",
                                 "ip4-dhcp-client-detect"),
  };
  VNET_FEATURE_INIT (ip4_nat_classify, static) = {
    .arc_name = "ip4-unicast",
    .node_name = "nat44-classify",
    .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa"),
  };
  VNET_FEATURE_INIT (ip4_snat_det_in2out, static) = {
    .arc_name = "ip4-unicast",
    .node_name = "nat44-det-in2out",
    .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa"),
  };
  VNET_FEATURE_INIT (ip4_snat_det_out2in, static) = {
    .arc_name = "ip4-unicast",
    .node_name = "nat44-det-out2in",
    .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa",
                                 "ip4-dhcp-client-detect"),
  };
  VNET_FEATURE_INIT (ip4_nat_det_classify, static) = {
    .arc_name = "ip4-unicast",
    .node_name = "nat44-det-classify",
    .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa"),
  };
  VNET_FEATURE_INIT (ip4_nat44_ed_in2out, static) = {
    .arc_name = "ip4-unicast",
    .node_name = "nat44-ed-in2out",
    .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa"),
  };
  VNET_FEATURE_INIT (ip4_nat44_ed_out2in, static) = {
    .arc_name = "ip4-unicast",
    .node_name = "nat44-ed-out2in",
    .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa",
                                 "ip4-dhcp-client-detect"),
  };
  VNET_FEATURE_INIT (ip4_nat44_ed_classify, static) = {
    .arc_name = "ip4-unicast",
    .node_name = "nat44-ed-classify",
    .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa"),
  };
  VNET_FEATURE_INIT (ip4_snat_in2out_worker_handoff, static) = {
    .arc_name = "ip4-unicast",
    .node_name = "nat44-in2out-worker-handoff",
    .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa"),
  };
  VNET_FEATURE_INIT (ip4_snat_out2in_worker_handoff, static) = {
    .arc_name = "ip4-unicast",
    .node_name = "nat44-out2in-worker-handoff",
    .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa",
                                 "ip4-dhcp-client-detect"),
  };
  VNET_FEATURE_INIT (ip4_nat_handoff_classify, static) = {
    .arc_name = "ip4-unicast",
    .node_name = "nat44-handoff-classify",
    .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa"),
  };
  VNET_FEATURE_INIT (ip4_snat_in2out_fast, static) = {
    .arc_name = "ip4-unicast",
    .node_name = "nat44-in2out-fast",
    .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa"),
  };
  VNET_FEATURE_INIT (ip4_snat_out2in_fast, static) = {
    .arc_name = "ip4-unicast",
    .node_name = "nat44-out2in-fast",
    .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa",
                                 "ip4-dhcp-client-detect"),
  };
  VNET_FEATURE_INIT (ip4_snat_hairpin_dst, static) = {
    .arc_name = "ip4-unicast",
    .node_name = "nat44-hairpin-dst",
    .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa"),
  };
  VNET_FEATURE_INIT (ip4_nat44_ed_hairpin_dst, static) = {
    .arc_name = "ip4-unicast",
    .node_name = "nat44-ed-hairpin-dst",
    .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa"),
  };
  
  /* Hook up output features */
  VNET_FEATURE_INIT (ip4_snat_in2out_output, static) = {
    .arc_name = "ip4-output",
    .node_name = "nat44-in2out-output",
    .runs_after = VNET_FEATURES ("acl-plugin-out-ip4-fa"),
  };
  VNET_FEATURE_INIT (ip4_snat_in2out_output_worker_handoff, static) = {
    .arc_name = "ip4-output",
    .node_name = "nat44-in2out-output-worker-handoff",
    .runs_after = VNET_FEATURES ("acl-plugin-out-ip4-fa"),
  };
  VNET_FEATURE_INIT (ip4_snat_hairpin_src, static) = {
    .arc_name = "ip4-output",
    .node_name = "nat44-hairpin-src",
    .runs_after = VNET_FEATURES ("acl-plugin-out-ip4-fa"),
  };
  VNET_FEATURE_INIT (ip4_nat44_ed_in2out_output, static) = {
    .arc_name = "ip4-output",
    .node_name = "nat44-ed-in2out-output",
    .runs_after = VNET_FEATURES ("acl-plugin-out-ip4-fa"),
  };
  VNET_FEATURE_INIT (ip4_nat44_ed_hairpin_src, static) = {
    .arc_name = "ip4-output",
    .node_name = "nat44-ed-hairpin-src",
    .runs_after = VNET_FEATURES ("acl-plugin-out-ip4-fa"),
  };
  
  /* Hook up ip4-local features */
  VNET_FEATURE_INIT (ip4_nat_hairpinning, static) =
  {
    .arc_name = "ip4-local",
    .node_name = "nat44-hairpinning",
    .runs_before = VNET_FEATURES("ip4-local-end-of-arc"),
  };
  VNET_FEATURE_INIT (ip4_nat44_ed_hairpinning, static) =
  {
    .arc_name = "ip4-local",
    .node_name = "nat44-ed-hairpinning",
    .runs_before = VNET_FEATURES("ip4-local-end-of-arc"),
  };
  
  
  VLIB_PLUGIN_REGISTER () = {
      .version = VPP_BUILD_VER,
      .description = "Network Address Translation",
  };
  /* *INDENT-ON* */
  
  void
  nat_free_session_data (snat_main_t * sm, snat_session_t * s, u32 thread_index)
  {
    snat_session_key_t key;
    clib_bihash_kv_8_8_t kv;
    nat_ed_ses_key_t ed_key;
    clib_bihash_kv_16_8_t ed_kv;
    snat_main_per_thread_data_t *tsm =
      vec_elt_at_index (sm->per_thread_data, thread_index);
  
    if (is_fwd_bypass_session (s))
      {
        ed_key.l_addr = s->in2out.addr;
        ed_key.r_addr = s->ext_host_addr;
        ed_key.l_port = s->in2out.port;
        ed_key.r_port = s->ext_host_port;
        ed_key.proto = snat_proto_to_ip_proto (s->in2out.protocol);
        ed_key.fib_index = 0;
        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_log_warn ("in2out_ed key del failed");
        return;
      }
  
    /* session lookup tables */
    if (is_ed_session (s))
      {
        if (is_affinity_sessions (s))
  	nat_affinity_unlock (s->ext_host_addr, s->out2in.addr,
  			     s->in2out.protocol, s->out2in.port);
        ed_key.l_addr = s->out2in.addr;
        ed_key.r_addr = s->ext_host_addr;
        ed_key.fib_index = s->out2in.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->out2in.port;
  	  ed_key.r_port = s->ext_host_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->out2in_ed, &ed_kv, 0))
  	nat_log_warn ("out2in_ed key del failed");
        ed_key.l_addr = s->in2out.addr;
        ed_key.fib_index = s->in2out.fib_index;
        if (!snat_is_unk_proto_session (s))
  	ed_key.l_port = s->in2out.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_log_warn ("in2out_ed key del failed");
      }
    else
      {
        kv.key = s->in2out.as_u64;
        if (clib_bihash_add_del_8_8 (&tsm->in2out, &kv, 0))
  	nat_log_warn ("in2out key del failed");
        kv.key = s->out2in.as_u64;
        if (clib_bihash_add_del_8_8 (&tsm->out2in, &kv, 0))
  	nat_log_warn ("out2in key del failed");
      }
  
    if (snat_is_unk_proto_session (s))
      return;
  
    /* log NAT event */
    snat_ipfix_logging_nat44_ses_delete (s->in2out.addr.as_u32,
  				       s->out2in.addr.as_u32,
  				       s->in2out.protocol,
  				       s->in2out.port,
  				       s->out2in.port, s->in2out.fib_index);
  
    /* Twice NAT address and port for external host */
    if (is_twice_nat_session (s))
      {
        key.protocol = s->in2out.protocol;
        key.port = s->ext_host_nat_port;
        key.addr.as_u32 = s->ext_host_nat_addr.as_u32;
        snat_free_outside_address_and_port (sm->twice_nat_addresses,
  					  thread_index, &key);
      }
  
    if (snat_is_session_static (s))
      return;
  
    snat_free_outside_address_and_port (sm->addresses, thread_index,
  				      &s->out2in);
  }
  
  snat_user_t *
  nat_user_get_or_create (snat_main_t * sm, ip4_address_t * addr, u32 fib_index,
  			u32 thread_index)
  {
    snat_user_t *u = 0;
    snat_user_key_t user_key;
    clib_bihash_kv_8_8_t kv, value;
    snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
    dlist_elt_t *per_user_list_head_elt;
  
    user_key.addr.as_u32 = addr->as_u32;
    user_key.fib_index = fib_index;
    kv.key = user_key.as_u64;
  
    /* Ever heard of the "user" = src ip4 address before? */
    if (clib_bihash_search_8_8 (&tsm->user_hash, &kv, &value))
      {
        /* no, make a new one */
        pool_get (tsm->users, u);
        clib_memset (u, 0, sizeof (*u));
        u->addr.as_u32 = addr->as_u32;
        u->fib_index = fib_index;
  
        pool_get (tsm->list_pool, per_user_list_head_elt);
  
        u->sessions_per_user_list_head_index = per_user_list_head_elt -
  	tsm->list_pool;
  
        clib_dlist_init (tsm->list_pool, u->sessions_per_user_list_head_index);
  
        kv.value = u - tsm->users;
  
        /* add user */
        if (clib_bihash_add_del_8_8 (&tsm->user_hash, &kv, 1))
  	nat_log_warn ("user_hash keay add failed");
      }
    else
      {
        u = pool_elt_at_index (tsm->users, value.value);
      }
  
    return u;
  }
  
  snat_session_t *
  nat_session_alloc_or_recycle (snat_main_t * sm, snat_user_t * u,
  			      u32 thread_index)
  {
    snat_session_t *s;
    snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
    u32 oldest_per_user_translation_list_index, session_index;
    dlist_elt_t *oldest_per_user_translation_list_elt;
    dlist_elt_t *per_user_translation_list_elt;
  
    /* Over quota? Recycle the least recently used translation */
    if ((u->nsessions + u->nstaticsessions) >= sm->max_translations_per_user)
      {
        oldest_per_user_translation_list_index =
  	clib_dlist_remove_head (tsm->list_pool,
  				u->sessions_per_user_list_head_index);
  
        ASSERT (oldest_per_user_translation_list_index != ~0);
  
        /* Add it back to the end of the LRU list */
        clib_dlist_addtail (tsm->list_pool,
  			  u->sessions_per_user_list_head_index,
  			  oldest_per_user_translation_list_index);
        /* Get the list element */
        oldest_per_user_translation_list_elt =
  	pool_elt_at_index (tsm->list_pool,
  			   oldest_per_user_translation_list_index);
  
        /* Get the session index from the list element */
        session_index = oldest_per_user_translation_list_elt->value;
  
        /* Get the session */
        s = pool_elt_at_index (tsm->sessions, session_index);
        nat_free_session_data (sm, s, thread_index);
        if (snat_is_session_static (s))
  	u->nstaticsessions--;
        else
  	u->nsessions--;
        s->flags = 0;
        s->total_bytes = 0;
        s->total_pkts = 0;
        s->state = 0;
        s->ext_host_addr.as_u32 = 0;
        s->ext_host_port = 0;
        s->ext_host_nat_addr.as_u32 = 0;
        s->ext_host_nat_port = 0;
      }
    else
      {
        pool_get (tsm->sessions, s);
        clib_memset (s, 0, sizeof (*s));
  
        /* Create list elts */
        pool_get (tsm->list_pool, per_user_translation_list_elt);
        clib_dlist_init (tsm->list_pool,
  		       per_user_translation_list_elt - tsm->list_pool);
  
        per_user_translation_list_elt->value = s - tsm->sessions;
        s->per_user_index = per_user_translation_list_elt - tsm->list_pool;
        s->per_user_list_head_index = u->sessions_per_user_list_head_index;
  
        clib_dlist_addtail (tsm->list_pool,
  			  s->per_user_list_head_index,
  			  per_user_translation_list_elt - tsm->list_pool);
      }
  
    return s;
  }
  
  snat_session_t *
  nat_ed_session_alloc (snat_main_t * sm, snat_user_t * u, u32 thread_index,
  		      f64 now)
  {
    snat_session_t *s;
    snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
    dlist_elt_t *per_user_translation_list_elt, *oldest_elt;
    u32 oldest_index;
    u64 sess_timeout_time;
  
    if (PREDICT_FALSE (!(u->nsessions) && !(u->nstaticsessions)))
      goto alloc_new;
  
    oldest_index =
      clib_dlist_remove_head (tsm->list_pool,
  			    u->sessions_per_user_list_head_index);
    oldest_elt = pool_elt_at_index (tsm->list_pool, oldest_index);
    s = pool_elt_at_index (tsm->sessions, oldest_elt->value);
    sess_timeout_time = s->last_heard + (f64) nat44_session_get_timeout (sm, s);
    if (now >= sess_timeout_time)
      {
        clib_dlist_addtail (tsm->list_pool,
  			  u->sessions_per_user_list_head_index, oldest_index);
        nat_free_session_data (sm, s, thread_index);
        if (snat_is_session_static (s))
  	u->nstaticsessions--;
        else
  	u->nsessions--;
        s->flags = 0;
        s->total_bytes = 0;
        s->total_pkts = 0;
        s->state = 0;
        s->ext_host_addr.as_u32 = 0;
        s->ext_host_port = 0;
        s->ext_host_nat_addr.as_u32 = 0;
        s->ext_host_nat_port = 0;
      }
    else
      {
        clib_dlist_addhead (tsm->list_pool,
  			  u->sessions_per_user_list_head_index, oldest_index);
        if ((u->nsessions + u->nstaticsessions) >=
  	  sm->max_translations_per_user)
  	{
  	  nat_log_warn ("max translations per user %U", format_ip4_address,
  			&u->addr);
  	  snat_ipfix_logging_max_entries_per_user
  	    (sm->max_translations_per_user, u->addr.as_u32);
  	  return 0;
  	}
        else
  	{
  	alloc_new:
  	  pool_get (tsm->sessions, s);
  	  clib_memset (s, 0, sizeof (*s));
  
  	  /* Create list elts */
  	  pool_get (tsm->list_pool, per_user_translation_list_elt);
  	  clib_dlist_init (tsm->list_pool,
  			   per_user_translation_list_elt - tsm->list_pool);
  
  	  per_user_translation_list_elt->value = s - tsm->sessions;
  	  s->per_user_index = per_user_translation_list_elt - tsm->list_pool;
  	  s->per_user_list_head_index = u->sessions_per_user_list_head_index;
  
  	  clib_dlist_addtail (tsm->list_pool,
  			      s->per_user_list_head_index,
  			      per_user_translation_list_elt - tsm->list_pool);
  	}
      }
  
    return s;
  }
  
  void
  snat_add_del_addr_to_fib (ip4_address_t * addr, u8 p_len, u32 sw_if_index,
  			  int is_add)
  {
    fib_prefix_t prefix = {
      .fp_len = p_len,
      .fp_proto = FIB_PROTOCOL_IP4,
      .fp_addr = {
  		.ip4.as_u32 = addr->as_u32,
  		},
    };
    u32 fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
  
    if (is_add)
      fib_table_entry_update_one_path (fib_index,
  				     &prefix,
  				     FIB_SOURCE_PLUGIN_LOW,
  				     (FIB_ENTRY_FLAG_CONNECTED |
  				      FIB_ENTRY_FLAG_LOCAL |
  				      FIB_ENTRY_FLAG_EXCLUSIVE),
  				     DPO_PROTO_IP4,
  				     NULL,
  				     sw_if_index,
  				     ~0, 1, NULL, FIB_ROUTE_PATH_FLAG_NONE);
    else
      fib_table_entry_delete (fib_index, &prefix, FIB_SOURCE_PLUGIN_LOW);
  }
  
  int
  snat_add_address (snat_main_t * sm, ip4_address_t * addr, u32 vrf_id,
  		  u8 twice_nat)
  {
    snat_address_t *ap;
    snat_interface_t *i;
    vlib_thread_main_t *tm = vlib_get_thread_main ();
  
    if (twice_nat && !sm->endpoint_dependent)
      return VNET_API_ERROR_FEATURE_DISABLED;
  
    /* Check if address already exists */
    /* *INDENT-OFF* */
    vec_foreach (ap, twice_nat ? sm->twice_nat_addresses : sm->addresses)
      {
        if (ap->addr.as_u32 == addr->as_u32)
          return VNET_API_ERROR_VALUE_EXIST;
      }
    /* *INDENT-ON* */
  
    if (twice_nat)
      vec_add2 (sm->twice_nat_addresses, ap, 1);
    else
      vec_add2 (sm->addresses, ap, 1);
  
    ap->addr = *addr;
    if (vrf_id != ~0)
      ap->fib_index =
        fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4, vrf_id,
  					 FIB_SOURCE_PLUGIN_LOW);
    else
      ap->fib_index = ~0;
  #define _(N, i, n, s) \
    clib_bitmap_alloc (ap->busy_##n##_port_bitmap, 65535); \
    ap->busy_##n##_ports = 0; \
    ap->busy_##n##_ports_per_thread = 0;\
    vec_validate_init_empty (ap->busy_##n##_ports_per_thread, tm->n_vlib_mains - 1, 0);
    foreach_snat_protocol
  #undef _
      if (twice_nat)
      return 0;
  
    /* Add external address to FIB */
    /* *INDENT-OFF* */
    pool_foreach (i, sm->interfaces,
    ({
      if (nat_interface_is_inside(i) || sm->out2in_dpo)
        continue;
  
      snat_add_del_addr_to_fib(addr, 32, i->sw_if_index, 1);
      break;
    }));
    pool_foreach (i, sm->output_feature_interfaces,
    ({
      if (nat_interface_is_inside(i) || sm->out2in_dpo)
        continue;
  
      snat_add_del_addr_to_fib(addr, 32, i->sw_if_index, 1);
      break;
    }));
    /* *INDENT-ON* */
  
    return 0;
  }
  
  static int
  is_snat_address_used_in_static_mapping (snat_main_t * sm, ip4_address_t addr)
  {
    snat_static_mapping_t *m;
    /* *INDENT-OFF* */
    pool_foreach (m, sm->static_mappings,
    ({
        if (is_addr_only_static_mapping (m) ||
            is_out2in_only_static_mapping (m) ||
            is_identity_static_mapping (m))
          continue;
        if (m->external_addr.as_u32 == addr.as_u32)
          return 1;
    }));
    /* *INDENT-ON* */
  
    return 0;
  }
  
  void
  increment_v4_address (ip4_address_t * a)
  {
    u32 v;
  
    v = clib_net_to_host_u32 (a->as_u32) + 1;
    a->as_u32 = clib_host_to_net_u32 (v);
  }
  
  static void
  snat_add_static_mapping_when_resolved (snat_main_t * sm,
  				       ip4_address_t l_addr,
  				       u16 l_port,
  				       u32 sw_if_index,
  				       u16 e_port,
  				       u32 vrf_id,
  				       snat_protocol_t proto,
  				       int addr_only, int is_add, u8 * tag,
  				       int twice_nat, int out2in_only,
  				       int identity_nat)
  {
    snat_static_map_resolve_t *rp;
  
    vec_add2 (sm->to_resolve, rp, 1);
    rp->l_addr.as_u32 = l_addr.as_u32;
    rp->l_port = l_port;
    rp->sw_if_index = sw_if_index;
    rp->e_port = e_port;
    rp->vrf_id = vrf_id;
    rp->proto = proto;
    rp->addr_only = addr_only;
    rp->is_add = is_add;
    rp->twice_nat = twice_nat;
    rp->out2in_only = out2in_only;
    rp->identity_nat = identity_nat;
    rp->tag = vec_dup (tag);
  }
  
  static u32
  get_thread_idx_by_port (u16 e_port)
  {
    snat_main_t *sm = &snat_main;
    u32 thread_idx = sm->num_workers;
    if (sm->num_workers > 1)
      {
        thread_idx =
  	sm->first_worker_index +
  	sm->workers[(e_port - 1024) / sm->port_per_thread];
      }
    return thread_idx;
  }
  
  int
  snat_add_static_mapping (ip4_address_t l_addr, ip4_address_t e_addr,
  			 u16 l_port, u16 e_port, u32 vrf_id, int addr_only,
  			 u32 sw_if_index, snat_protocol_t proto, int is_add,
  			 twice_nat_type_t twice_nat, u8 out2in_only, u8 * tag,
  			 u8 identity_nat)
  {
    snat_main_t *sm = &snat_main;
    snat_static_mapping_t *m;
    snat_session_key_t m_key;
    clib_bihash_kv_8_8_t kv, value;
    snat_address_t *a = 0;
    u32 fib_index = ~0;
    snat_interface_t *interface;
    int i;
    snat_main_per_thread_data_t *tsm;
    snat_user_key_t u_key;
    snat_user_t *u;
    dlist_elt_t *head, *elt;
    u32 elt_index, head_index;
    u32 ses_index;
    u64 user_index;
    snat_session_t *s;
    snat_static_map_resolve_t *rp, *rp_match = 0;
    nat44_lb_addr_port_t *local;
    u8 find = 0;
  
    if (!sm->endpoint_dependent)
      {
        if (twice_nat || out2in_only)
  	return VNET_API_ERROR_FEATURE_DISABLED;
      }
  
    /* If the external address is a specific interface address */
    if (sw_if_index != ~0)
      {
        ip4_address_t *first_int_addr;
  
        for (i = 0; i < vec_len (sm->to_resolve); i++)
  	{
  	  rp = sm->to_resolve + i;
  	  if (rp->sw_if_index != sw_if_index ||
  	      rp->l_addr.as_u32 != l_addr.as_u32 ||
  	      rp->vrf_id != vrf_id || rp->addr_only != addr_only)
  	    continue;
  
  	  if (!addr_only)
  	    {
  	      if (rp->l_port != l_port || rp->e_port != e_port
  		  || rp->proto != proto)
  		continue;
  	    }
  
  	  rp_match = rp;
  	  break;
  	}
  
        /* Might be already set... */
        first_int_addr = ip4_interface_first_address
  	(sm->ip4_main, sw_if_index, 0 /* just want the address */ );
  
        if (is_add)
  	{
  	  if (rp_match)
  	    return VNET_API_ERROR_VALUE_EXIST;
  
  	  snat_add_static_mapping_when_resolved
  	    (sm, l_addr, l_port, sw_if_index, e_port, vrf_id, proto,
  	     addr_only, is_add, tag, twice_nat, out2in_only, identity_nat);
  
  	  /* DHCP resolution required? */
  	  if (first_int_addr == 0)
  	    {
  	      return 0;
  	    }
  	  else
  	    {
  	      e_addr.as_u32 = first_int_addr->as_u32;
  	      /* Identity mapping? */
  	      if (l_addr.as_u32 == 0)
  		l_addr.as_u32 = e_addr.as_u32;
  	    }
  	}
        else
  	{
  	  if (!rp_match)
  	    return VNET_API_ERROR_NO_SUCH_ENTRY;
  
  	  vec_del1 (sm->to_resolve, i);
  
  	  if (first_int_addr)
  	    {
  	      e_addr.as_u32 = first_int_addr->as_u32;
  	      /* Identity mapping? */
  	      if (l_addr.as_u32 == 0)
  		l_addr.as_u32 = e_addr.as_u32;
  	    }
  	  else
  	    return 0;
  	}
      }
  
    m_key.addr = e_addr;
    m_key.port = addr_only ? 0 : e_port;
    m_key.protocol = addr_only ? 0 : proto;
    m_key.fib_index = 0;
    kv.key = m_key.as_u64;
    if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
      m = 0;
    else
      m = pool_elt_at_index (sm->static_mappings, value.value);
  
    if (is_add)
      {
        if (m)
  	{
  	  if (is_identity_static_mapping (m))
  	    {
                /* *INDENT-OFF* */
                vec_foreach (local, m->locals)
                  {
                    if (local->vrf_id == vrf_id)
                      return VNET_API_ERROR_VALUE_EXIST;
                  }
                /* *INDENT-ON* */
  	      vec_add2 (m->locals, local, 1);
  	      local->vrf_id = vrf_id;
  	      local->fib_index =
  		fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4, vrf_id,
  						   FIB_SOURCE_PLUGIN_LOW);
  	      m_key.addr = m->local_addr;
  	      m_key.port = m->local_port;
  	      m_key.protocol = m->proto;
  	      m_key.fib_index = local->fib_index;
  	      kv.key = m_key.as_u64;
  	      kv.value = m - sm->static_mappings;
  	      clib_bihash_add_del_8_8 (&sm->static_mapping_by_local, &kv, 1);
  	      return 0;
  	    }
  	  else
  	    return VNET_API_ERROR_VALUE_EXIST;
  	}
  
        if (twice_nat && addr_only)
  	return VNET_API_ERROR_UNSUPPORTED;
  
        /* Convert VRF id to FIB index */
        if (vrf_id != ~0)
  	fib_index =
  	  fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4, vrf_id,
  					     FIB_SOURCE_PLUGIN_LOW);
        /* If not specified use inside VRF id from SNAT plugin startup config */
        else
  	{
  	  fib_index = sm->inside_fib_index;
  	  vrf_id = sm->inside_vrf_id;
  	}
  
        if (!(out2in_only || identity_nat))
  	{
  	  m_key.addr = l_addr;
  	  m_key.port = addr_only ? 0 : l_port;
  	  m_key.protocol = addr_only ? 0 : proto;
  	  m_key.fib_index = fib_index;
  	  kv.key = m_key.as_u64;
  	  if (!clib_bihash_search_8_8
  	      (&sm->static_mapping_by_local, &kv, &value))
  	    return VNET_API_ERROR_VALUE_EXIST;
  	}
  
        /* Find external address in allocated addresses and reserve port for
           address and port pair mapping when dynamic translations enabled */
        if (!(addr_only || sm->static_mapping_only || out2in_only))
  	{
  	  for (i = 0; i < vec_len (sm->addresses); i++)
  	    {
  	      if (sm->addresses[i].addr.as_u32 == e_addr.as_u32)
  		{
  		  a = sm->addresses + i;
  		  /* External port must be unused */
  		  switch (proto)
  		    {
  #define _(N, j, n, s) \
                      case SNAT_PROTOCOL_##N: \
                        if (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, e_port)) \
                          return VNET_API_ERROR_INVALID_VALUE; \
                        clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, e_port, 1); \
                        if (e_port > 1024) \
                          { \
                            a->busy_##n##_ports++; \
                            a->busy_##n##_ports_per_thread[get_thread_idx_by_port(e_port)]++; \
                          } \
                        break;
  		      foreach_snat_protocol
  #undef _
  		    default:
  		      nat_log_info ("unknown protocol");
  		      return VNET_API_ERROR_INVALID_VALUE_2;
  		    }
  		  break;
  		}
  	    }
  	  /* External address must be allocated */
  	  if (!a && (l_addr.as_u32 != e_addr.as_u32))
  	    {
  	      if (sw_if_index != ~0)
  		{
  		  for (i = 0; i < vec_len (sm->to_resolve); i++)
  		    {
  		      rp = sm->to_resolve + i;
  		      if (rp->addr_only)
  			continue;
  		      if (rp->sw_if_index != sw_if_index &&
  			  rp->l_addr.as_u32 != l_addr.as_u32 &&
  			  rp->vrf_id != vrf_id && rp->l_port != l_port &&
  			  rp->e_port != e_port && rp->proto != proto)
  			continue;
  
  		      vec_del1 (sm->to_resolve, i);
  		      break;
  		    }
  		}
  	      return VNET_API_ERROR_NO_SUCH_ENTRY;
  	    }
  	}
  
        pool_get (sm->static_mappings, m);
        clib_memset (m, 0, sizeof (*m));
        m->tag = vec_dup (tag);
        m->local_addr = l_addr;
        m->external_addr = e_addr;
        m->twice_nat = twice_nat;
        if (out2in_only)
  	m->flags |= NAT_STATIC_MAPPING_FLAG_OUT2IN_ONLY;
        if (addr_only)
  	m->flags |= NAT_STATIC_MAPPING_FLAG_ADDR_ONLY;
        if (identity_nat)
  	{
  	  m->flags |= NAT_STATIC_MAPPING_FLAG_IDENTITY_NAT;
  	  vec_add2 (m->locals, local, 1);
  	  local->vrf_id = vrf_id;
  	  local->fib_index = fib_index;
  	}
        else
  	{
  	  m->vrf_id = vrf_id;
  	  m->fib_index = fib_index;
  	}
        if (!addr_only)
  	{
  	  m->local_port = l_port;
  	  m->external_port = e_port;
  	  m->proto = proto;
  	}
  
        if (sm->num_workers > 1)
  	{
  	  ip4_header_t ip = {
  	    .src_address = m->local_addr,
  	  };
  	  vec_add1 (m->workers, sm->worker_in2out_cb (&ip, m->fib_index));
  	  tsm = vec_elt_at_index (sm->per_thread_data, m->workers[0]);
  	}
        else
  	tsm = vec_elt_at_index (sm->per_thread_data, sm->num_workers);
  
        m_key.addr = m->local_addr;
        m_key.port = m->local_port;
        m_key.protocol = m->proto;
        m_key.fib_index = fib_index;
        kv.key = m_key.as_u64;
        kv.value = m - sm->static_mappings;
        if (!out2in_only)
  	clib_bihash_add_del_8_8 (&sm->static_mapping_by_local, &kv, 1);
  
        m_key.addr = m->external_addr;
        m_key.port = m->external_port;
        m_key.fib_index = 0;
        kv.key = m_key.as_u64;
        kv.value = m - sm->static_mappings;
        clib_bihash_add_del_8_8 (&sm->static_mapping_by_external, &kv, 1);
  
        /* Delete dynamic sessions matching local address (+ local port) */
        if (!(sm->static_mapping_only))
  	{
  	  u_key.addr = m->local_addr;
  	  u_key.fib_index = m->fib_index;
  	  kv.key = u_key.as_u64;
  	  if (!clib_bihash_search_8_8 (&tsm->user_hash, &kv, &value))
  	    {
  	      user_index = value.value;
  	      u = pool_elt_at_index (tsm->users, user_index);
  	      if (u->nsessions)
  		{
  		  head_index = u->sessions_per_user_list_head_index;
  		  head = pool_elt_at_index (tsm->list_pool, head_index);
  		  elt_index = head->next;
  		  elt = pool_elt_at_index (tsm->list_pool, elt_index);
  		  ses_index = elt->value;
  		  while (ses_index != ~0)
  		    {
  		      s = pool_elt_at_index (tsm->sessions, ses_index);
  		      elt = pool_elt_at_index (tsm->list_pool, elt->next);
  		      ses_index = elt->value;
  
  		      if (snat_is_session_static (s))
  			continue;
  
  		      if (!addr_only
  			  && (clib_net_to_host_u16 (s->in2out.port) !=
  			      m->local_port))
  			continue;
  
  		      nat_free_session_data (sm, s,
  					     tsm - sm->per_thread_data);
  		      nat44_delete_session (sm, s, tsm - sm->per_thread_data);
  
  		      if (!addr_only && !sm->endpoint_dependent)
  			break;
  		    }
  		}
  	    }
  	}
      }
    else
      {
        if (!m)
  	{
  	  if (sw_if_index != ~0)
  	    return 0;
  	  else
  	    return VNET_API_ERROR_NO_SUCH_ENTRY;
  	}
  
        if (identity_nat)
  	{
  	  if (vrf_id == ~0)
  	    vrf_id = sm->inside_vrf_id;
  
  	  for (i = 0; i < vec_len (m->locals); i++)
  	    {
  	      if (m->locals[i].vrf_id == vrf_id)
  		{
  		  find = 1;
  		  break;
  		}
  	    }
  	  if (!find)
  	    return VNET_API_ERROR_NO_SUCH_ENTRY;
  
  	  fib_index = m->locals[i].fib_index;
  	  vec_del1 (m->locals, i);
  	}
        else
  	fib_index = m->fib_index;
  
        /* Free external address port */
        if (!(addr_only || sm->static_mapping_only || out2in_only))
  	{
  	  for (i = 0; i < vec_len (sm->addresses); i++)
  	    {
  	      if (sm->addresses[i].addr.as_u32 == e_addr.as_u32)
  		{
  		  a = sm->addresses + i;
  		  switch (proto)
  		    {
  #define _(N, j, n, s) \
                      case SNAT_PROTOCOL_##N: \
                        clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, e_port, 0); \
                        if (e_port > 1024) \
                          { \
                            a->busy_##n##_ports--; \
                            a->busy_##n##_ports_per_thread[get_thread_idx_by_port(e_port)]--; \
                          } \
                        break;
  		      foreach_snat_protocol
  #undef _
  		    default:
  		      nat_log_info ("unknown protocol");
  		      return VNET_API_ERROR_INVALID_VALUE_2;
  		    }
  		  break;
  		}
  	    }
  	}
  
        if (sm->num_workers > 1)
  	tsm = vec_elt_at_index (sm->per_thread_data, m->workers[0]);
        else
  	tsm = vec_elt_at_index (sm->per_thread_data, sm->num_workers);
  
        m_key.addr = m->local_addr;
        m_key.port = m->local_port;
        m_key.protocol = m->proto;
        m_key.fib_index = fib_index;
        kv.key = m_key.as_u64;
        if (!out2in_only)
  	clib_bihash_add_del_8_8 (&sm->static_mapping_by_local, &kv, 0);
  
        /* Delete session(s) for static mapping if exist */
        if (!(sm->static_mapping_only) ||
  	  (sm->static_mapping_only && sm->static_mapping_connection_tracking))
  	{
  	  u_key.addr = m->local_addr;
  	  u_key.fib_index = fib_index;
  	  kv.key = u_key.as_u64;
  	  if (!clib_bihash_search_8_8 (&tsm->user_hash, &kv, &value))
  	    {
  	      user_index = value.value;
  	      u = pool_elt_at_index (tsm->users, user_index);
  	      if (u->nstaticsessions)
  		{
  		  head_index = u->sessions_per_user_list_head_index;
  		  head = pool_elt_at_index (tsm->list_pool, head_index);
  		  elt_index = head->next;
  		  elt = pool_elt_at_index (tsm->list_pool, elt_index);
  		  ses_index = elt->value;
  		  while (ses_index != ~0)
  		    {
  		      s = pool_elt_at_index (tsm->sessions, ses_index);
  		      elt = pool_elt_at_index (tsm->list_pool, elt->next);
  		      ses_index = elt->value;
  
  		      if (!addr_only)
  			{
  			  if ((s->out2in.addr.as_u32 != e_addr.as_u32) ||
  			      (clib_net_to_host_u16 (s->out2in.port) !=
  			       e_port))
  			    continue;
  			}
  
  		      if (is_lb_session (s))
  			continue;
  
  		      if (!snat_is_session_static (s))
  			continue;
  
  		      nat_free_session_data (sm, s,
  					     tsm - sm->per_thread_data);
  		      nat44_delete_session (sm, s, tsm - sm->per_thread_data);
  
  		      if (!addr_only && !sm->endpoint_dependent)
  			break;
  		    }
  		}
  	    }
  	}
  
        fib_table_unlock (fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_PLUGIN_LOW);
        if (vec_len (m->locals))
  	return 0;
  
        m_key.addr = m->external_addr;
        m_key.port = m->external_port;
        m_key.fib_index = 0;
        kv.key = m_key.as_u64;
        clib_bihash_add_del_8_8 (&sm->static_mapping_by_external, &kv, 0);
  
        vec_free (m->tag);
        vec_free (m->workers);
        /* Delete static mapping from pool */
        pool_put (sm->static_mappings, m);
      }
  
    if (!addr_only || (l_addr.as_u32 == e_addr.as_u32))
      return 0;
  
    /* Add/delete external address to FIB */
    /* *INDENT-OFF* */
    pool_foreach (interface, sm->interfaces,
    ({
      if (nat_interface_is_inside(interface) || sm->out2in_dpo)
        continue;
  
      snat_add_del_addr_to_fib(&e_addr, 32, interface->sw_if_index, is_add);
      break;
    }));
    pool_foreach (interface, sm->output_feature_interfaces,
    ({
      if (nat_interface_is_inside(interface) || sm->out2in_dpo)
        continue;
  
      snat_add_del_addr_to_fib(&e_addr, 32, interface->sw_if_index, is_add);
      break;
    }));
    /* *INDENT-ON* */
  
    return 0;
  }
  
  int
  nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
  				 snat_protocol_t proto,
  				 nat44_lb_addr_port_t * locals, u8 is_add,
  				 twice_nat_type_t twice_nat, u8 out2in_only,
  				 u8 * tag, u32 affinity)
  {
    snat_main_t *sm = &snat_main;
    snat_static_mapping_t *m;
    snat_session_key_t m_key;
    clib_bihash_kv_8_8_t kv, value;
    snat_address_t *a = 0;
    int i;
    nat44_lb_addr_port_t *local;
    u32 elt_index, head_index, ses_index;
    snat_main_per_thread_data_t *tsm;
    snat_user_key_t u_key;
    snat_user_t *u;
    snat_session_t *s;
    dlist_elt_t *head, *elt;
    uword *bitmap = 0;
  
    if (!sm->endpoint_dependent)
      return VNET_API_ERROR_FEATURE_DISABLED;
  
    m_key.addr = e_addr;
    m_key.port = e_port;
    m_key.protocol = proto;
    m_key.fib_index = 0;
    kv.key = m_key.as_u64;
    if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
      m = 0;
    else
      m = pool_elt_at_index (sm->static_mappings, value.value);
  
    if (is_add)
      {
        if (m)
  	return VNET_API_ERROR_VALUE_EXIST;
  
        if (vec_len (locals) < 2)
  	return VNET_API_ERROR_INVALID_VALUE;
  
        /* Find external address in allocated addresses and reserve port for
           address and port pair mapping when dynamic translations enabled */
        if (!(sm->static_mapping_only || out2in_only))
  	{
  	  for (i = 0; i < vec_len (sm->addresses); i++)
  	    {
  	      if (sm->addresses[i].addr.as_u32 == e_addr.as_u32)
  		{
  		  a = sm->addresses + i;
  		  /* External port must be unused */
  		  switch (proto)
  		    {
  #define _(N, j, n, s) \
                      case SNAT_PROTOCOL_##N: \
                        if (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, e_port)) \
                          return VNET_API_ERROR_INVALID_VALUE; \
                        clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, e_port, 1); \
                        if (e_port > 1024) \
                          { \
                            a->busy_##n##_ports++; \
                            a->busy_##n##_ports_per_thread[get_thread_idx_by_port(e_port)]++; \
                          } \
                        break;
  		      foreach_snat_protocol
  #undef _
  		    default:
  		      nat_log_info ("unknown protocol");
  		      return VNET_API_ERROR_INVALID_VALUE_2;
  		    }
  		  break;
  		}
  	    }
  	  /* External address must be allocated */
  	  if (!a)
  	    return VNET_API_ERROR_NO_SUCH_ENTRY;
  	}
  
        pool_get (sm->static_mappings, m);
        clib_memset (m, 0, sizeof (*m));
        m->tag = vec_dup (tag);
        m->external_addr = e_addr;
        m->external_port = e_port;
        m->proto = proto;
        m->twice_nat = twice_nat;
        m->flags |= NAT_STATIC_MAPPING_FLAG_LB;
        if (out2in_only)
  	m->flags |= NAT_STATIC_MAPPING_FLAG_OUT2IN_ONLY;
        m->affinity = affinity;
  
        if (affinity)
  	m->affinity_per_service_list_head_index =
  	  nat_affinity_get_per_service_list_head_index ();
        else
  	m->affinity_per_service_list_head_index = ~0;
  
        m_key.addr = m->external_addr;
        m_key.port = m->external_port;
        m_key.protocol = m->proto;
        m_key.fib_index = 0;
        kv.key = m_key.as_u64;
        kv.value = m - sm->static_mappings;
        if (clib_bihash_add_del_8_8 (&sm->static_mapping_by_external, &kv, 1))
  	{
  	  nat_log_err ("static_mapping_by_external key add failed");
  	  return VNET_API_ERROR_UNSPECIFIED;
  	}
  
        m_key.fib_index = m->fib_index;
        for (i = 0; i < vec_len (locals); i++)
  	{
  	  locals[i].fib_index =
  	    fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
  					       locals[i].vrf_id,
  					       FIB_SOURCE_PLUGIN_LOW);
  	  m_key.addr = locals[i].addr;
  	  m_key.fib_index = locals[i].fib_index;
  	  if (!out2in_only)
  	    {
  	      m_key.port = locals[i].port;
  	      kv.key = m_key.as_u64;
  	      kv.value = m - sm->static_mappings;
  	      clib_bihash_add_del_8_8 (&sm->static_mapping_by_local, &kv, 1);
  	    }
  	  locals[i].prefix = (i == 0) ? locals[i].probability :
  	    (locals[i - 1].prefix + locals[i].probability);
  	  vec_add1 (m->locals, locals[i]);
  	  if (sm->num_workers > 1)
  	    {
  	      ip4_header_t ip = {
  		.src_address = locals[i].addr,
  	      };
  	      bitmap =
  		clib_bitmap_set (bitmap,
  				 sm->worker_in2out_cb (&ip, m->fib_index), 1);
  	    }
  	}
  
        /* Assign workers */
        if (sm->num_workers > 1)
  	{
            /* *INDENT-OFF* */
            clib_bitmap_foreach (i, bitmap,
              ({
                 vec_add1(m->workers, i);
              }));
            /* *INDENT-ON* */
  	}
      }
    else
      {
        if (!m)
  	return VNET_API_ERROR_NO_SUCH_ENTRY;
  
        if (!is_lb_static_mapping (m))
  	return VNET_API_ERROR_INVALID_VALUE;
  
        /* Free external address port */
        if (!(sm->static_mapping_only || out2in_only))
  	{
  	  for (i = 0; i < vec_len (sm->addresses); i++)
  	    {
  	      if (sm->addresses[i].addr.as_u32 == e_addr.as_u32)
  		{
  		  a = sm->addresses + i;
  		  switch (proto)
  		    {
  #define _(N, j, n, s) \
                      case SNAT_PROTOCOL_##N: \
                        clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, e_port, 0); \
                        if (e_port > 1024) \
                          { \
                            a->busy_##n##_ports--; \
                            a->busy_##n##_ports_per_thread[get_thread_idx_by_port(e_port)]--; \
                          } \
                        break;
  		      foreach_snat_protocol
  #undef _
  		    default:
  		      nat_log_info ("unknown protocol");
  		      return VNET_API_ERROR_INVALID_VALUE_2;
  		    }
  		  break;
  		}
  	    }
  	}
  
        m_key.addr = m->external_addr;
        m_key.port = m->external_port;
        m_key.protocol = m->proto;
        m_key.fib_index = 0;
        kv.key = m_key.as_u64;
        if (clib_bihash_add_del_8_8 (&sm->static_mapping_by_external, &kv, 0))
  	{
  	  nat_log_err ("static_mapping_by_external key del failed");
  	  return VNET_API_ERROR_UNSPECIFIED;
  	}
  
        /* *INDENT-OFF* */
        vec_foreach (local, m->locals)
          {
            fib_table_unlock (local->fib_index, FIB_PROTOCOL_IP4,
                              FIB_SOURCE_PLUGIN_LOW);
            m_key.addr = local->addr;
            if (!out2in_only)
              {
                m_key.port = local->port;
                m_key.fib_index = local->fib_index;
                kv.key = m_key.as_u64;
                if (clib_bihash_add_del_8_8(&sm->static_mapping_by_local, &kv, 0))
                  {
                    nat_log_err ("static_mapping_by_local key del failed");
                    return VNET_API_ERROR_UNSPECIFIED;
                  }
              }
  
            if (sm->num_workers > 1)
              {
                ip4_header_t ip = {
                  .src_address = local->addr,
                };
                tsm = vec_elt_at_index (sm->per_thread_data,
                                        sm->worker_in2out_cb (&ip, m->fib_index));
              }
            else
              tsm = vec_elt_at_index (sm->per_thread_data, sm->num_workers);
  
            /* Delete sessions */
            u_key.addr = local->addr;
            u_key.fib_index = m->fib_index;
            kv.key = u_key.as_u64;
            if (!clib_bihash_search_8_8 (&tsm->user_hash, &kv, &value))
              {
                u = pool_elt_at_index (tsm->users, value.value);
                if (u->nstaticsessions)
                  {
                    head_index = u->sessions_per_user_list_head_index;
                    head = pool_elt_at_index (tsm->list_pool, head_index);
                    elt_index = head->next;
                    elt = pool_elt_at_index (tsm->list_pool, elt_index);
                    ses_index = elt->value;
                    while (ses_index != ~0)
                      {
                        s =  pool_elt_at_index (tsm->sessions, ses_index);
                        elt = pool_elt_at_index (tsm->list_pool, elt->next);
                        ses_index = elt->value;
  
                        if (!(is_lb_session (s)))
                          continue;
  
                        if ((s->in2out.addr.as_u32 != local->addr.as_u32) ||
                            (clib_net_to_host_u16 (s->in2out.port) != local->port))
                          continue;
  
                        nat_free_session_data (sm, s, tsm - sm->per_thread_data);
                        nat44_delete_session (sm, s, tsm - sm->per_thread_data);
                      }
                  }
              }
          }
        /* *INDENT-ON* */
        if (m->affinity)
  	nat_affinity_flush_service (m->affinity_per_service_list_head_index);
        vec_free (m->locals);
        vec_free (m->tag);
        vec_free (m->workers);
  
        pool_put (sm->static_mappings, m);
      }
  
    return 0;
  }
  
  int
  snat_del_address (snat_main_t * sm, ip4_address_t addr, u8 delete_sm,
  		  u8 twice_nat)
  {
    snat_address_t *a = 0;
    snat_session_t *ses;
    u32 *ses_to_be_removed = 0, *ses_index;
    snat_main_per_thread_data_t *tsm;
    snat_static_mapping_t *m;
    snat_interface_t *interface;
    int i;
    snat_address_t *addresses =
      twice_nat ? sm->twice_nat_addresses : sm->addresses;
  
    /* Find SNAT address */
    for (i = 0; i < vec_len (addresses); i++)
      {
        if (addresses[i].addr.as_u32 == addr.as_u32)
  	{
  	  a = addresses + i;
  	  break;
  	}
      }
    if (!a)
      return VNET_API_ERROR_NO_SUCH_ENTRY;
  
    if (delete_sm)
      {
        /* *INDENT-OFF* */
        pool_foreach (m, sm->static_mappings,
        ({
            if (m->external_addr.as_u32 == addr.as_u32)
              (void) snat_add_static_mapping (m->local_addr, m->external_addr,
                                              m->local_port, m->external_port,
                                              m->vrf_id, is_addr_only_static_mapping(m), ~0,
                                              m->proto, 0, m->twice_nat,
                                              is_out2in_only_static_mapping(m), m->tag, is_identity_static_mapping(m));
        }));
        /* *INDENT-ON* */
      }
    else
      {
        /* Check if address is used in some static mapping */
        if (is_snat_address_used_in_static_mapping (sm, addr))
  	{
  	  nat_log_notice ("address used in static mapping");
  	  return VNET_API_ERROR_UNSPECIFIED;
  	}
      }
  
    if (a->fib_index != ~0)
      fib_table_unlock (a->fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_PLUGIN_LOW);
  
    /* Delete sessions using address */
    if (a->busy_tcp_ports || a->busy_udp_ports || a->busy_icmp_ports)
      {
        /* *INDENT-OFF* */
        vec_foreach (tsm, sm->per_thread_data)
          {
            pool_foreach (ses, tsm->sessions, ({
              if (ses->out2in.addr.as_u32 == addr.as_u32)
                {
                  nat_free_session_data (sm, ses, tsm - sm->per_thread_data);
                  vec_add1 (ses_to_be_removed, ses - tsm->sessions);
                }
            }));
  
            vec_foreach (ses_index, ses_to_be_removed)
              {
                ses = pool_elt_at_index (tsm->sessions, ses_index[0]);
                nat44_delete_session (sm, ses, tsm - sm->per_thread_data);
              }
  
            vec_free (ses_to_be_removed);
          }
        /* *INDENT-ON* */
      }
  
  #define _(N, i, n, s) \
    clib_bitmap_free (a->busy_##n##_port_bitmap); \
    vec_free (a->busy_##n##_ports_per_thread);
    foreach_snat_protocol
  #undef _
      if (twice_nat)
      {
        vec_del1 (sm->twice_nat_addresses, i);
        return 0;
      }
    else
      vec_del1 (sm->addresses, i);
  
    /* Delete external address from FIB */
    /* *INDENT-OFF* */
    pool_foreach (interface, sm->interfaces,
    ({
      if (nat_interface_is_inside(interface) || sm->out2in_dpo)
        continue;
  
      snat_add_del_addr_to_fib(&addr, 32, interface->sw_if_index, 0);
      break;
    }));
    pool_foreach (interface, sm->output_feature_interfaces,
    ({
      if (nat_interface_is_inside(interface) || sm->out2in_dpo)
        continue;
  
      snat_add_del_addr_to_fib(&addr, 32, interface->sw_if_index, 0);
      break;
    }));
    /* *INDENT-ON* */
  
    return 0;
  }
  
  int
  snat_interface_add_del (u32 sw_if_index, u8 is_inside, int is_del)
  {
    snat_main_t *sm = &snat_main;
    snat_interface_t *i;
    const char *feature_name, *del_feature_name;
    snat_address_t *ap;
    snat_static_mapping_t *m;
    snat_det_map_t *dm;
    nat_outside_fib_t *outside_fib;
    u32 fib_index = fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
  						       sw_if_index);
  
    if (sm->out2in_dpo && !is_inside)
      return VNET_API_ERROR_UNSUPPORTED;
  
    /* *INDENT-OFF* */
    pool_foreach (i, sm->output_feature_interfaces,
    ({
      if (i->sw_if_index == sw_if_index)
        return VNET_API_ERROR_VALUE_EXIST;
    }));
    /* *INDENT-ON* */
  
    if (sm->static_mapping_only && !(sm->static_mapping_connection_tracking))
      feature_name = is_inside ? "nat44-in2out-fast" : "nat44-out2in-fast";
    else
      {
        if (sm->num_workers > 1 && !sm->deterministic)
  	feature_name =
  	  is_inside ? "nat44-in2out-worker-handoff" :
  	  "nat44-out2in-worker-handoff";
        else if (sm->deterministic)
  	feature_name = is_inside ? "nat44-det-in2out" : "nat44-det-out2in";
        else if (sm->endpoint_dependent)
  	feature_name = is_inside ? "nat44-ed-in2out" : "nat44-ed-out2in";
        else
  	feature_name = is_inside ? "nat44-in2out" : "nat44-out2in";
      }
  
    if (sm->fq_in2out_index == ~0 && !sm->deterministic && sm->num_workers > 1)
      sm->fq_in2out_index = vlib_frame_queue_main_init (sm->in2out_node_index,
  						      NAT_FQ_NELTS);
  
    if (sm->fq_out2in_index == ~0 && !sm->deterministic && sm->num_workers > 1)
      sm->fq_out2in_index = vlib_frame_queue_main_init (sm->out2in_node_index,
  						      NAT_FQ_NELTS);
  
    if (!is_inside)
      {
        /* *INDENT-OFF* */
        vec_foreach (outside_fib, sm->outside_fibs)
          {
            if (outside_fib->fib_index == fib_index)
              {
                if (is_del)
                  {
                    outside_fib->refcount--;
                    if (!outside_fib->refcount)
                      vec_del1 (sm->outside_fibs, outside_fib - sm->outside_fibs);
                  }
                else
                  outside_fib->refcount++;
                goto feature_set;
              }
          }
        /* *INDENT-ON* */
        if (!is_del)
  	{
  	  vec_add2 (sm->outside_fibs, outside_fib, 1);
  	  outside_fib->refcount = 1;
  	  outside_fib->fib_index = fib_index;
  	}
      }
  feature_set:
    /* *INDENT-OFF* */
    pool_foreach (i, sm->interfaces,
    ({
      if (i->sw_if_index == sw_if_index)
        {
          if (is_del)
            {
              if (nat_interface_is_inside(i) && nat_interface_is_outside(i))
                {
                  if (is_inside)
                    i->flags &= ~NAT_INTERFACE_FLAG_IS_INSIDE;
                  else
                    i->flags &= ~NAT_INTERFACE_FLAG_IS_OUTSIDE;
  
                  if (sm->num_workers > 1 && !sm->deterministic)
                    {
                      del_feature_name = "nat44-handoff-classify";
                      feature_name = !is_inside ?  "nat44-in2out-worker-handoff" :
                                                   "nat44-out2in-worker-handoff";
                    }
                  else if (sm->deterministic)
                    {
                      del_feature_name = "nat44-det-classify";
                      feature_name = !is_inside ?  "nat44-det-in2out" :
                                                   "nat44-det-out2in";
                    }
                  else if (sm->endpoint_dependent)
                    {
                      del_feature_name = "nat44-ed-classify";
                      feature_name = !is_inside ?  "nat44-ed-in2out" :
                                                   "nat44-ed-out2in";
                    }
                  else
                    {
                      del_feature_name = "nat44-classify";
                      feature_name = !is_inside ?  "nat44-in2out" : "nat44-out2in";
                    }
  
                  vnet_feature_enable_disable ("ip4-unicast", del_feature_name,
                                               sw_if_index, 0, 0, 0);
                  vnet_feature_enable_disable ("ip4-unicast", feature_name,
                                               sw_if_index, 1, 0, 0);
                  if (!is_inside)
                    {
                      if (sm->endpoint_dependent)
                        vnet_feature_enable_disable ("ip4-local",
                                                     "nat44-ed-hairpinning",
                                                     sw_if_index, 1, 0, 0);
                      else if (!sm->deterministic)
                        vnet_feature_enable_disable ("ip4-local",
                                                     "nat44-hairpinning",
                                                     sw_if_index, 1, 0, 0);
                    }
                }
              else
                {
                  vnet_feature_enable_disable ("ip4-unicast", feature_name,
                                               sw_if_index, 0, 0, 0);
                  pool_put (sm->interfaces, i);
                  if (is_inside)
                    {
                      if (sm->endpoint_dependent)
                        vnet_feature_enable_disable ("ip4-local",
                                                     "nat44-ed-hairpinning",
                                                     sw_if_index, 0, 0, 0);
                      else if (!sm->deterministic)
                        vnet_feature_enable_disable ("ip4-local",
                                                     "nat44-hairpinning",
                                                     sw_if_index, 0, 0, 0);
                    }
                }
            }
          else
            {
              if ((nat_interface_is_inside(i) && is_inside) ||
                  (nat_interface_is_outside(i) && !is_inside))
                return 0;
  
              if (sm->num_workers > 1 && !sm->deterministic)
                {
                  del_feature_name = !is_inside ?  "nat44-in2out-worker-handoff" :
                                                   "nat44-out2in-worker-handoff";
                  feature_name = "nat44-handoff-classify";
                }
              else if (sm->deterministic)
                {
                  del_feature_name = !is_inside ?  "nat44-det-in2out" :
                                                   "nat44-det-out2in";
                  feature_name = "nat44-det-classify";
                }
              else if (sm->endpoint_dependent)
                {
                  del_feature_name = !is_inside ?  "nat44-ed-in2out" :
                                                   "nat44-ed-out2in";
                  feature_name = "nat44-ed-classify";
                }
              else
                {
                  del_feature_name = !is_inside ?  "nat44-in2out" : "nat44-out2in";
                  feature_name = "nat44-classify";
                }
  
              vnet_feature_enable_disable ("ip4-unicast", del_feature_name,
                                           sw_if_index, 0, 0, 0);
              vnet_feature_enable_disable ("ip4-unicast", feature_name,
                                           sw_if_index, 1, 0, 0);
              if (!is_inside)
                {
                  if (sm->endpoint_dependent)
                    vnet_feature_enable_disable ("ip4-local", "nat44-ed-hairpinning",
                                                 sw_if_index, 0, 0, 0);
                  else if (!sm->deterministic)
                    vnet_feature_enable_disable ("ip4-local", "nat44-hairpinning",
                                                 sw_if_index, 0, 0, 0);
                }
              goto set_flags;
            }
  
          goto fib;
        }
    }));
    /* *INDENT-ON* */
  
    if (is_del)
      return VNET_API_ERROR_NO_SUCH_ENTRY;
  
    pool_get (sm->interfaces, i);
    i->sw_if_index = sw_if_index;
    i->flags = 0;
    vnet_feature_enable_disable ("ip4-unicast", feature_name, sw_if_index, 1, 0,
  			       0);
  
    if (is_inside && !sm->out2in_dpo)
      {
        if (sm->endpoint_dependent)
  	vnet_feature_enable_disable ("ip4-local", "nat44-ed-hairpinning",
  				     sw_if_index, 1, 0, 0);
        else if (!sm->deterministic)
  	vnet_feature_enable_disable ("ip4-local", "nat44-hairpinning",
  				     sw_if_index, 1, 0, 0);
      }
  
  set_flags:
    if (is_inside)
      {
        i->flags |= NAT_INTERFACE_FLAG_IS_INSIDE;
        return 0;
      }
    else
      i->flags |= NAT_INTERFACE_FLAG_IS_OUTSIDE;
  
    /* Add/delete external addresses to FIB */
  fib:
    /* *INDENT-OFF* */
    vec_foreach (ap, sm->addresses)
      snat_add_del_addr_to_fib(&ap->addr, 32, sw_if_index, !is_del);
  
    pool_foreach (m, sm->static_mappings,
    ({
      if (!(is_addr_only_static_mapping(m)) || (m->local_addr.as_u32 == m->external_addr.as_u32))
        continue;
  
      snat_add_del_addr_to_fib(&m->external_addr, 32, sw_if_index, !is_del);
    }));
  
    pool_foreach (dm, sm->det_maps,
    ({
      snat_add_del_addr_to_fib(&dm->out_addr, dm->out_plen, sw_if_index, !is_del);
    }));
    /* *INDENT-ON* */
  
    return 0;
  }
  
  int
  snat_interface_add_del_output_feature (u32 sw_if_index,
  				       u8 is_inside, int is_del)
  {
    snat_main_t *sm = &snat_main;
    snat_interface_t *i;
    snat_address_t *ap;
    snat_static_mapping_t *m;
  
    if (sm->deterministic ||
        (sm->static_mapping_only && !(sm->static_mapping_connection_tracking)))
      return VNET_API_ERROR_UNSUPPORTED;
  
    /* *INDENT-OFF* */
    pool_foreach (i, sm->interfaces,
    ({
      if (i->sw_if_index == sw_if_index)
        return VNET_API_ERROR_VALUE_EXIST;
    }));
    /* *INDENT-ON* */
  
    if (is_inside)
      {
        if (sm->endpoint_dependent)
  	{
  	  vnet_feature_enable_disable ("ip4-unicast", "nat44-ed-hairpin-dst",
  				       sw_if_index, !is_del, 0, 0);
  	  vnet_feature_enable_disable ("ip4-output", "nat44-ed-hairpin-src",
  				       sw_if_index, !is_del, 0, 0);
  	}
        else
  	{
  	  vnet_feature_enable_disable ("ip4-unicast", "nat44-hairpin-dst",
  				       sw_if_index, !is_del, 0, 0);
  	  vnet_feature_enable_disable ("ip4-output", "nat44-hairpin-src",
  				       sw_if_index, !is_del, 0, 0);
  	}
        goto fq;
      }
  
    if (sm->num_workers > 1)
      {
        vnet_feature_enable_disable ("ip4-unicast",
  				   "nat44-out2in-worker-handoff",
  				   sw_if_index, !is_del, 0, 0);
        vnet_feature_enable_disable ("ip4-output",
  				   "nat44-in2out-output-worker-handoff",
  				   sw_if_index, !is_del, 0, 0);
      }
    else
      {
        if (sm->endpoint_dependent)
  	{
  	  vnet_feature_enable_disable ("ip4-unicast", "nat44-ed-out2in",
  				       sw_if_index, !is_del, 0, 0);
  	  vnet_feature_enable_disable ("ip4-output", "nat44-ed-in2out-output",
  				       sw_if_index, !is_del, 0, 0);
  	}
        else
  	{
  	  vnet_feature_enable_disable ("ip4-unicast", "nat44-out2in",
  				       sw_if_index, !is_del, 0, 0);
  	  vnet_feature_enable_disable ("ip4-output", "nat44-in2out-output",
  				       sw_if_index, !is_del, 0, 0);
  	}
      }
  
  fq:
    if (sm->fq_in2out_output_index == ~0 && sm->num_workers > 1)
      sm->fq_in2out_output_index =
        vlib_frame_queue_main_init (sm->in2out_output_node_index, 0);
  
    if (sm->fq_out2in_index == ~0 && sm->num_workers > 1)
      sm->fq_out2in_index =
        vlib_frame_queue_main_init (sm->out2in_node_index, 0);
  
    /* *INDENT-OFF* */
    pool_foreach (i, sm->output_feature_interfaces,
    ({
      if (i->sw_if_index == sw_if_index)
        {
          if (is_del)
            pool_put (sm->output_feature_interfaces, i);
          else
            return VNET_API_ERROR_VALUE_EXIST;
  
          goto fib;
        }
    }));
    /* *INDENT-ON* */
  
    if (is_del)
      return VNET_API_ERROR_NO_SUCH_ENTRY;
  
    pool_get (sm->output_feature_interfaces, i);
    i->sw_if_index = sw_if_index;
    i->flags = 0;
    if (is_inside)
      i->flags |= NAT_INTERFACE_FLAG_IS_INSIDE;
    else
      i->flags |= NAT_INTERFACE_FLAG_IS_OUTSIDE;
  
    /* Add/delete external addresses to FIB */
  fib:
    if (is_inside)
      return 0;
  
    /* *INDENT-OFF* */
    vec_foreach (ap, sm->addresses)
      snat_add_del_addr_to_fib(&ap->addr, 32, sw_if_index, !is_del);
  
    pool_foreach (m, sm->static_mappings,
    ({
      if (!((is_addr_only_static_mapping(m)))  || (m->local_addr.as_u32 == m->external_addr.as_u32))
        continue;
  
      snat_add_del_addr_to_fib(&m->external_addr, 32, sw_if_index, !is_del);
    }));
    /* *INDENT-ON* */
  
    return 0;
  }
  
  int
  snat_set_workers (uword * bitmap)
  {
    snat_main_t *sm = &snat_main;
    int i, j = 0;
  
    if (sm->num_workers < 2)
      return VNET_API_ERROR_FEATURE_DISABLED;
  
    if (clib_bitmap_last_set (bitmap) >= sm->num_workers)
      return VNET_API_ERROR_INVALID_WORKER;
  
    vec_free (sm->workers);
    /* *INDENT-OFF* */
    clib_bitmap_foreach (i, bitmap,
      ({
        vec_add1(sm->workers, i);
        sm->per_thread_data[sm->first_worker_index + i].snat_thread_index = j;
        j++;
      }));
    /* *INDENT-ON* */
  
    sm->port_per_thread = (0xffff - 1024) / _vec_len (sm->workers);
    sm->num_snat_thread = _vec_len (sm->workers);
  
    return 0;
  }
  
  
  static void
  snat_ip4_add_del_interface_address_cb (ip4_main_t * im,
  				       uword opaque,
  				       u32 sw_if_index,
  				       ip4_address_t * address,
  				       u32 address_length,
  				       u32 if_address_index, u32 is_delete);
  
  static void
  nat_ip4_add_del_addr_only_sm_cb (ip4_main_t * im,
  				 uword opaque,
  				 u32 sw_if_index,
  				 ip4_address_t * address,
  				 u32 address_length,
  				 u32 if_address_index, u32 is_delete);
  
  static int
  nat_alloc_addr_and_port_default (snat_address_t * addresses,
  				 u32 fib_index,
  				 u32 thread_index,
  				 snat_session_key_t * k,
  				 u16 port_per_thread, u32 snat_thread_index);
  
  static clib_error_t *
  snat_init (vlib_main_t * vm)
  {
    snat_main_t *sm = &snat_main;
    clib_error_t *error = 0;
    ip4_main_t *im = &ip4_main;
    ip_lookup_main_t *lm = &im->lookup_main;
    uword *p;
    vlib_thread_registration_t *tr;
    vlib_thread_main_t *tm = vlib_get_thread_main ();
    uword *bitmap = 0;
    u32 i;
    ip4_add_del_interface_address_callback_t cb4;
    vlib_node_t *error_drop_node;
  
    sm->vlib_main = vm;
    sm->vnet_main = vnet_get_main ();
    sm->ip4_main = im;
    sm->ip4_lookup_main = lm;
    sm->api_main = &api_main;
    sm->first_worker_index = 0;
    sm->num_workers = 0;
    sm->num_snat_thread = 1;
    sm->workers = 0;
    sm->port_per_thread = 0xffff - 1024;
    sm->fq_in2out_index = ~0;
    sm->fq_out2in_index = ~0;
    sm->udp_timeout = SNAT_UDP_TIMEOUT;
    sm->tcp_established_timeout = SNAT_TCP_ESTABLISHED_TIMEOUT;
    sm->tcp_transitory_timeout = SNAT_TCP_TRANSITORY_TIMEOUT;
    sm->icmp_timeout = SNAT_ICMP_TIMEOUT;
    sm->alloc_addr_and_port = nat_alloc_addr_and_port_default;
    sm->addr_and_port_alloc_alg = NAT_ADDR_AND_PORT_ALLOC_ALG_DEFAULT;
    sm->forwarding_enabled = 0;
    sm->log_class = vlib_log_register_class ("nat", 0);
    error_drop_node = vlib_get_node_by_name (vm, (u8 *) "error-drop");
    sm->error_node_index = error_drop_node->index;
    sm->mss_clamping = 0;
  
    p = hash_get_mem (tm->thread_registrations_by_name, "workers");
    if (p)
      {
        tr = (vlib_thread_registration_t *) p[0];
        if (tr)
  	{
  	  sm->num_workers = tr->count;
  	  sm->first_worker_index = tr->first_index;
  	}
      }
  
    vec_validate (sm->per_thread_data, tm->n_vlib_mains - 1);
  
    /* Use all available workers by default */
    if (sm->num_workers > 1)
      {
        for (i = 0; i < sm->num_workers; i++)
  	bitmap = clib_bitmap_set (bitmap, i, 1);
        snat_set_workers (bitmap);
        clib_bitmap_free (bitmap);
      }
    else
      {
        sm->per_thread_data[0].snat_thread_index = 0;
      }
  
    error = snat_api_init (vm, sm);
    if (error)
      return error;
  
    /* Set up the interface address add/del callback */
    cb4.function = snat_ip4_add_del_interface_address_cb;
    cb4.function_opaque = 0;
  
    vec_add1 (im->add_del_interface_address_callbacks, cb4);
  
    cb4.function = nat_ip4_add_del_addr_only_sm_cb;
    cb4.function_opaque = 0;
  
    vec_add1 (im->add_del_interface_address_callbacks, cb4);
  
    nat_dpo_module_init ();
  
    /* Init IPFIX logging */
    snat_ipfix_logging_init (vm);
  
    /* Init NAT64 */
    error = nat64_init (vm);
    if (error)
      return error;
  
    dslite_init (vm);
  
    nat66_init ();
  
    /* Init virtual fragmenentation reassembly */
    return nat_reass_init (vm);
  }
  
  VLIB_INIT_FUNCTION (snat_init);
  
  void
  snat_free_outside_address_and_port (snat_address_t * addresses,
  				    u32 thread_index, snat_session_key_t * k)
  {
    snat_address_t *a;
    u32 address_index;
    u16 port_host_byte_order = clib_net_to_host_u16 (k->port);
  
    for (address_index = 0; address_index < vec_len (addresses);
         address_index++)
      {
        if (addresses[address_index].addr.as_u32 == k->addr.as_u32)
  	break;
      }
  
    ASSERT (address_index < vec_len (addresses));
  
    a = addresses + address_index;
  
    switch (k->protocol)
      {
  #define _(N, i, n, s) \
      case SNAT_PROTOCOL_##N: \
        ASSERT (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, \
          port_host_byte_order) == 1); \
        clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, \
          port_host_byte_order, 0); \
        a->busy_##n##_ports--; \
        a->busy_##n##_ports_per_thread[thread_index]--; \
        break;
        foreach_snat_protocol
  #undef _
      default:
        nat_log_info ("unknown protocol");
        return;
      }
  }
  
  int
  snat_static_mapping_match (snat_main_t * sm,
  			   snat_session_key_t match,
  			   snat_session_key_t * mapping,
  			   u8 by_external,
  			   u8 * is_addr_only,
  			   twice_nat_type_t * twice_nat,
  			   lb_nat_type_t * lb, ip4_address_t * ext_host_addr,
  			   u8 * is_identity_nat)
  {
    clib_bihash_kv_8_8_t kv, value;
    snat_static_mapping_t *m;
    snat_session_key_t m_key;
    clib_bihash_8_8_t *mapping_hash = &sm->static_mapping_by_local;
    u32 rand, lo = 0, hi, mid;
    u8 backend_index;
  
    m_key.fib_index = match.fib_index;
    if (by_external)
      {
        mapping_hash = &sm->static_mapping_by_external;
        m_key.fib_index = 0;
      }
  
    m_key.addr = match.addr;
    m_key.port = clib_net_to_host_u16 (match.port);
    m_key.protocol = match.protocol;
  
    kv.key = m_key.as_u64;
  
    if (clib_bihash_search_8_8 (mapping_hash, &kv, &value))
      {
        /* Try address only mapping */
        m_key.port = 0;
        m_key.protocol = 0;
        kv.key = m_key.as_u64;
        if (clib_bihash_search_8_8 (mapping_hash, &kv, &value))
  	return 1;
      }
  
    m = pool_elt_at_index (sm->static_mappings, value.value);
  
    if (by_external)
      {
        if (is_lb_static_mapping (m))
  	{
  	  if (PREDICT_FALSE (lb != 0))
  	    *lb = m->affinity ? AFFINITY_LB_NAT : LB_NAT;
  	  if (m->affinity)
  	    {
  	      if (nat_affinity_find_and_lock (ext_host_addr[0], match.addr,
  					      match.protocol, match.port,
  					      &backend_index))
  		goto get_local;
  
  	      mapping->addr = m->locals[backend_index].addr;
  	      mapping->port =
  		clib_host_to_net_u16 (m->locals[backend_index].port);
  	      mapping->fib_index = m->locals[backend_index].fib_index;
  	      goto end;
  	    }
  	get_local:
  	  hi = vec_len (m->locals) - 1;
  	  rand = 1 + (random_u32 (&sm->random_seed) % m->locals[hi].prefix);
  	  while (lo < hi)
  	    {
  	      mid = ((hi - lo) >> 1) + lo;
  	      (rand > m->locals[mid].prefix) ? (lo = mid + 1) : (hi = mid);
  	    }
  	  if (!(m->locals[lo].prefix >= rand))
  	    return 1;
  	  if (PREDICT_FALSE (sm->num_workers > 1))
  	    {
  	      ip4_header_t ip = {
  		.src_address = m->locals[lo].addr,
  	      };
  	      if (sm->worker_in2out_cb (&ip, m->fib_index) !=
  		  vlib_get_thread_index ())
  		goto get_local;
  	    }
  	  mapping->addr = m->locals[lo].addr;
  	  mapping->port = clib_host_to_net_u16 (m->locals[lo].port);
  	  mapping->fib_index = m->locals[lo].fib_index;
  	  if (m->affinity)
  	    {
  	      if (nat_affinity_create_and_lock (ext_host_addr[0], match.addr,
  						match.protocol, match.port,
  						lo, m->affinity,
  						m->affinity_per_service_list_head_index))
  		nat_log_info ("create affinity record failed");
  	    }
  	}
        else
  	{
  	  if (PREDICT_FALSE (lb != 0))
  	    *lb = NO_LB_NAT;
  	  mapping->fib_index = m->fib_index;
  	  mapping->addr = m->local_addr;
  	  /* Address only mapping doesn't change port */
  	  mapping->port = is_addr_only_static_mapping (m) ? match.port
  	    : clib_host_to_net_u16 (m->local_port);
  	}
        mapping->protocol = m->proto;
      }
    else
      {
        mapping->addr = m->external_addr;
        /* Address only mapping doesn't change port */
        mapping->port = is_addr_only_static_mapping (m) ? match.port
  	: clib_host_to_net_u16 (m->external_port);
        mapping->fib_index = sm->outside_fib_index;
      }
  
  end:
    if (PREDICT_FALSE (is_addr_only != 0))
      *is_addr_only = is_addr_only_static_mapping (m);
  
    if (PREDICT_FALSE (twice_nat != 0))
      *twice_nat = m->twice_nat;
  
    if (PREDICT_FALSE (is_identity_nat != 0))
      *is_identity_nat = is_identity_static_mapping (m);
  
    return 0;
  }
  
  static_always_inline u16
  snat_random_port (u16 min, u16 max)
  {
    snat_main_t *sm = &snat_main;
    return min + random_u32 (&sm->random_seed) /
      (random_u32_max () / (max - min + 1) + 1);
  }
  
  int
  snat_alloc_outside_address_and_port (snat_address_t * addresses,
  				     u32 fib_index,
  				     u32 thread_index,
  				     snat_session_key_t * k,
  				     u16 port_per_thread,
  				     u32 snat_thread_index)
  {
    snat_main_t *sm = &snat_main;
  
    return sm->alloc_addr_and_port (addresses, fib_index, thread_index, k,
  				  port_per_thread, snat_thread_index);
  }
  
  static int
  nat_alloc_addr_and_port_default (snat_address_t * addresses,
  				 u32 fib_index,
  				 u32 thread_index,
  				 snat_session_key_t * k,
  				 u16 port_per_thread, u32 snat_thread_index)
  {
    int i;
    snat_address_t *a, *ga = 0;
    u32 portnum;
  
    for (i = 0; i < vec_len (addresses); i++)
      {
        a = addresses + i;
        switch (k->protocol)
  	{
  #define _(N, j, n, s) \
          case SNAT_PROTOCOL_##N: \
            if (a->busy_##n##_ports_per_thread[thread_index] < port_per_thread) \
              { \
                if (a->fib_index == fib_index) \
                  { \
                    while (1) \
                      { \
                        portnum = (port_per_thread * \
                          snat_thread_index) + \
                          snat_random_port(1, port_per_thread) + 1024; \
                        if (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, portnum)) \
                          continue; \
                        clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, portnum, 1); \
                        a->busy_##n##_ports_per_thread[thread_index]++; \
                        a->busy_##n##_ports++; \
                        k->addr = a->addr; \
                        k->port = clib_host_to_net_u16(portnum); \
                        return 0; \
                      } \
                  } \
                else if (a->fib_index == ~0) \
                  { \
                    ga = a; \
                  } \
              } \
            break;
  	  foreach_snat_protocol
  #undef _
  	default:
  	  nat_log_info ("unknown protocol");
  	  return 1;
  	}
  
      }
  
    if (ga)
      {
        a = ga;
        switch (k->protocol)
  	{
  #define _(N, j, n, s) \
          case SNAT_PROTOCOL_##N: \
            while (1) \
              { \
                portnum = (port_per_thread * \
                  snat_thread_index) + \
                  snat_random_port(1, port_per_thread) + 1024; \
                if (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, portnum)) \
                  continue; \
                clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, portnum, 1); \
                a->busy_##n##_ports_per_thread[thread_index]++; \
                a->busy_##n##_ports++; \
                k->addr = a->addr; \
                k->port = clib_host_to_net_u16(portnum); \
                return 0; \
              }
  	  break;
  	  foreach_snat_protocol
  #undef _
  	default:
  	  nat_log_info ("unknown protocol");
  	  return 1;
  	}
      }
  
    /* Totally out of translations to use... */
    snat_ipfix_logging_addresses_exhausted (0);
    return 1;
  }
  
  static int
  nat_alloc_addr_and_port_mape (snat_address_t * addresses,
  			      u32 fib_index,
  			      u32 thread_index,
  			      snat_session_key_t * k,
  			      u16 port_per_thread, u32 snat_thread_index)
  {
    snat_main_t *sm = &snat_main;
    snat_address_t *a = addresses;
    u16 m, ports, portnum, A, j;
    m = 16 - (sm->psid_offset + sm->psid_length);
    ports = (1 << (16 - sm->psid_length)) - (1 << m);
  
    if (!vec_len (addresses))
      goto exhausted;
  
    switch (k->protocol)
      {
  #define _(N, i, n, s) \
      case SNAT_PROTOCOL_##N: \
        if (a->busy_##n##_ports < ports) \
          { \
            while (1) \
              { \
                A = snat_random_port(1, pow2_mask(sm->psid_offset)); \
                j = snat_random_port(0, pow2_mask(m)); \
                portnum = A | (sm->psid << sm->psid_offset) | (j << (16 - m)); \
                if (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, portnum)) \
                  continue; \
                clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, portnum, 1); \
                a->busy_##n##_ports++; \
                k->addr = a->addr; \
                k->port = clib_host_to_net_u16 (portnum); \
                return 0; \
              } \
          } \
        break;
        foreach_snat_protocol
  #undef _
      default:
        nat_log_info ("unknown protocol");
        return 1;
      }
  
  exhausted:
    /* Totally out of translations to use... */
    snat_ipfix_logging_addresses_exhausted (0);
    return 1;
  }
  
  static int
  nat_alloc_addr_and_port_range (snat_address_t * addresses,
  			       u32 fib_index,
  			       u32 thread_index,
  			       snat_session_key_t * k,
  			       u16 port_per_thread, u32 snat_thread_index)
  {
    snat_main_t *sm = &snat_main;
    snat_address_t *a = addresses;
    u16 portnum, ports;
  
    ports = sm->end_port - sm->start_port + 1;
  
    if (!vec_len (addresses))
      goto exhausted;
  
    switch (k->protocol)
      {
  #define _(N, i, n, s) \
      case SNAT_PROTOCOL_##N: \
        if (a->busy_##n##_ports < ports) \
          { \
            while (1) \
              { \
                portnum = snat_random_port(sm->start_port, sm->end_port); \
                if (clib_bitmap_get_no_check (a->busy_##n##_port_bitmap, portnum)) \
                  continue; \
                clib_bitmap_set_no_check (a->busy_##n##_port_bitmap, portnum, 1); \
                a->busy_##n##_ports++; \
                k->addr = a->addr; \
                k->port = clib_host_to_net_u16 (portnum); \
                return 0; \
              } \
          } \
        break;
        foreach_snat_protocol
  #undef _
      default:
        nat_log_info ("unknown protocol");
        return 1;
      }
  
  exhausted:
    /* Totally out of translations to use... */
    snat_ipfix_logging_addresses_exhausted (0);
    return 1;
  }
  
  void
  nat44_add_del_address_dpo (ip4_address_t addr, u8 is_add)
  {
    dpo_id_t dpo_v4 = DPO_INVALID;
    fib_prefix_t pfx = {
      .fp_proto = FIB_PROTOCOL_IP4,
      .fp_len = 32,
      .fp_addr.ip4.as_u32 = addr.as_u32,
    };
  
    if (is_add)
      {
        nat_dpo_create (DPO_PROTO_IP4, 0, &dpo_v4);
        fib_table_entry_special_dpo_add (0, &pfx, FIB_SOURCE_PLUGIN_HI,
  				       FIB_ENTRY_FLAG_EXCLUSIVE, &dpo_v4);
        dpo_reset (&dpo_v4);
      }
    else
      {
        fib_table_entry_special_remove (0, &pfx, FIB_SOURCE_PLUGIN_HI);
      }
  }
  
  u8 *
  format_session_kvp (u8 * s, va_list * args)
  {
    clib_bihash_kv_8_8_t *v = va_arg (*args, clib_bihash_kv_8_8_t *);
    snat_session_key_t k;
  
    k.as_u64 = v->key;
  
    s = format (s, "%U session-index %llu", format_snat_key, &k, v->value);
  
    return s;
  }
  
  u8 *
  format_static_mapping_kvp (u8 * s, va_list * args)
  {
    clib_bihash_kv_8_8_t *v = va_arg (*args, clib_bihash_kv_8_8_t *);
    snat_session_key_t k;
  
    k.as_u64 = v->key;
  
    s = format (s, "%U static-mapping-index %llu",
  	      format_static_mapping_key, &k, v->value);
  
    return s;
  }
  
  u8 *
  format_user_kvp (u8 * s, va_list * args)
  {
    clib_bihash_kv_8_8_t *v = va_arg (*args, clib_bihash_kv_8_8_t *);
    snat_user_key_t k;
  
    k.as_u64 = v->key;
  
    s = format (s, "%U fib %d user-index %llu", format_ip4_address, &k.addr,
  	      k.fib_index, v->value);
  
    return s;
  }
  
  u8 *
  format_ed_session_kvp (u8 * s, va_list * args)
  {
    clib_bihash_kv_16_8_t *v = va_arg (*args, clib_bihash_kv_16_8_t *);
    nat_ed_ses_key_t k;
  
    k.as_u64[0] = v->key[0];
    k.as_u64[1] = v->key[1];
  
    s =
      format (s, "local %U:%d remote %U:%d proto %U fib %d session-index %llu",
  	    format_ip4_address, &k.l_addr, clib_net_to_host_u16 (k.l_port),
  	    format_ip4_address, &k.r_addr, clib_net_to_host_u16 (k.r_port),
  	    format_ip_protocol, k.proto, k.fib_index, v->value);
  
    return s;
  }
  
  static u32
  snat_get_worker_in2out_cb (ip4_header_t * ip0, u32 rx_fib_index0)
  {
    snat_main_t *sm = &snat_main;
    u32 next_worker_index = 0;
    u32 hash;
  
    next_worker_index = sm->first_worker_index;
    hash = ip0->src_address.as_u32 + (ip0->src_address.as_u32 >> 8) +
      (ip0->src_address.as_u32 >> 16) + (ip0->src_address.as_u32 >> 24);
  
    if (PREDICT_TRUE (is_pow2 (_vec_len (sm->workers))))
      next_worker_index += sm->workers[hash & (_vec_len (sm->workers) - 1)];
    else
      next_worker_index += sm->workers[hash % _vec_len (sm->workers)];
  
    return next_worker_index;
  }
  
  static u32
  snat_get_worker_out2in_cb (ip4_header_t * ip0, u32 rx_fib_index0)
  {
    snat_main_t *sm = &snat_main;
    udp_header_t *udp;
    u16 port;
    snat_session_key_t m_key;
    clib_bihash_kv_8_8_t kv, value;
    snat_static_mapping_t *m;
    u32 proto;
    u32 next_worker_index = 0;
  
    /* first try static mappings without port */
    if (PREDICT_FALSE (pool_elts (sm->static_mappings)))
      {
        m_key.addr = ip0->dst_address;
        m_key.port = 0;
        m_key.protocol = 0;
        m_key.fib_index = rx_fib_index0;
        kv.key = m_key.as_u64;
        if (!clib_bihash_search_8_8
  	  (&sm->static_mapping_by_external, &kv, &value))
  	{
  	  m = pool_elt_at_index (sm->static_mappings, value.value);
  	  return m->workers[0];
  	}
      }
  
    proto = ip_proto_to_snat_proto (ip0->protocol);
    udp = ip4_next_header (ip0);
    port = udp->dst_port;
  
    if (PREDICT_FALSE (ip4_is_fragment (ip0)))
      {
        if (PREDICT_FALSE (nat_reass_is_drop_frag (0)))
  	return vlib_get_thread_index ();
  
        if (PREDICT_TRUE (!ip4_is_first_fragment (ip0)))
  	{
  	  nat_reass_ip4_t *reass;
  
  	  reass = nat_ip4_reass_find (ip0->src_address, ip0->dst_address,
  				      ip0->fragment_id, ip0->protocol);
  
  	  if (reass && (reass->thread_index != (u32) ~ 0))
  	    return reass->thread_index;
  	  else
  	    return vlib_get_thread_index ();
  	}
      }
  
    /* unknown protocol */
    if (PREDICT_FALSE (proto == ~0))
      {
        /* use current thread */
        return vlib_get_thread_index ();
      }
  
    if (PREDICT_FALSE (ip0->protocol == IP_PROTOCOL_ICMP))
      {
        icmp46_header_t *icmp = (icmp46_header_t *) udp;
        icmp_echo_header_t *echo = (icmp_echo_header_t *) (icmp + 1);
        if (!icmp_is_error_message (icmp))
  	port = echo->identifier;
        else
  	{
  	  ip4_header_t *inner_ip = (ip4_header_t *) (echo + 1);
  	  proto = ip_proto_to_snat_proto (inner_ip->protocol);
  	  void *l4_header = ip4_next_header (inner_ip);
  	  switch (proto)
  	    {
  	    case SNAT_PROTOCOL_ICMP:
  	      icmp = (icmp46_header_t *) l4_header;
  	      echo = (icmp_echo_header_t *) (icmp + 1);
  	      port = echo->identifier;
  	      break;
  	    case SNAT_PROTOCOL_UDP:
  	    case SNAT_PROTOCOL_TCP:
  	      port = ((tcp_udp_header_t *) l4_header)->src_port;
  	      break;
  	    default:
  	      return vlib_get_thread_index ();
  	    }
  	}
      }
  
    /* try static mappings with port */
    if (PREDICT_FALSE (pool_elts (sm->static_mappings)))
      {
        m_key.addr = ip0->dst_address;
        m_key.port = clib_net_to_host_u16 (port);
        m_key.protocol = proto;
        m_key.fib_index = rx_fib_index0;
        kv.key = m_key.as_u64;
        if (!clib_bihash_search_8_8
  	  (&sm->static_mapping_by_external, &kv, &value))
  	{
  	  m = pool_elt_at_index (sm->static_mappings, value.value);
  	  return m->workers[0];
  	}
      }
  
    /* worker by outside port */
    next_worker_index = sm->first_worker_index;
    next_worker_index +=
      sm->workers[(clib_net_to_host_u16 (port) - 1024) / sm->port_per_thread];
    return next_worker_index;
  }
  
  static u32
  nat44_ed_get_worker_out2in_cb (ip4_header_t * ip, u32 rx_fib_index)
  {
    snat_main_t *sm = &snat_main;
    clib_bihash_kv_8_8_t kv, value;
    u32 proto, next_worker_index = 0;
    udp_header_t *udp;
    u16 port;
    snat_static_mapping_t *m;
    u32 hash;
  
    /* first try static mappings without port */
    if (PREDICT_FALSE (pool_elts (sm->static_mappings)))
      {
        make_sm_kv (&kv, &ip->dst_address, 0, rx_fib_index, 0);
        if (!clib_bihash_search_8_8
  	  (&sm->static_mapping_by_external, &kv, &value))
  	{
  	  m = pool_elt_at_index (sm->static_mappings, value.value);
  	  return m->workers[0];
  	}
      }
  
    proto = ip_proto_to_snat_proto (ip->protocol);
  
    /* unknown protocol */
    if (PREDICT_FALSE (proto == ~0))
      {
        /* use current thread */
        return vlib_get_thread_index ();
      }
  
    udp = ip4_next_header (ip);
    port = udp->dst_port;
  
    if (PREDICT_FALSE (ip->protocol == IP_PROTOCOL_ICMP))
      {
        icmp46_header_t *icmp = (icmp46_header_t *) udp;
        icmp_echo_header_t *echo = (icmp_echo_header_t *) (icmp + 1);
        if (!icmp_is_error_message (icmp))
  	port = echo->identifier;
        else
  	{
  	  ip4_header_t *inner_ip = (ip4_header_t *) (echo + 1);
  	  proto = ip_proto_to_snat_proto (inner_ip->protocol);
  	  void *l4_header = ip4_next_header (inner_ip);
  	  switch (proto)
  	    {
  	    case SNAT_PROTOCOL_ICMP:
  	      icmp = (icmp46_header_t *) l4_header;
  	      echo = (icmp_echo_header_t *) (icmp + 1);
  	      port = echo->identifier;
  	      break;
  	    case SNAT_PROTOCOL_UDP:
  	    case SNAT_PROTOCOL_TCP:
  	      port = ((tcp_udp_header_t *) l4_header)->src_port;
  	      break;
  	    default:
  	      return vlib_get_thread_index ();
  	    }
  	}
      }
  
    /* try static mappings with port */
    if (PREDICT_FALSE (pool_elts (sm->static_mappings)))
      {
        make_sm_kv (&kv, &ip->dst_address, proto, rx_fib_index,
  		  clib_net_to_host_u16 (port));
        if (!clib_bihash_search_8_8
  	  (&sm->static_mapping_by_external, &kv, &value))
  	{
  	  m = pool_elt_at_index (sm->static_mappings, value.value);
  	  if (!is_lb_static_mapping (m))
  	    return m->workers[0];
  
  	  hash = ip->src_address.as_u32 + (ip->src_address.as_u32 >> 8) +
  	    (ip->src_address.as_u32 >> 16) + (ip->src_address.as_u32 >> 24);
  
  	  if (PREDICT_TRUE (is_pow2 (_vec_len (m->workers))))
  	    return m->workers[hash & (_vec_len (m->workers) - 1)];
  	  else
  	    return m->workers[hash % _vec_len (m->workers)];
  	}
      }
  
    /* worker by outside port */
    next_worker_index = sm->first_worker_index;
    next_worker_index +=
      sm->workers[(clib_net_to_host_u16 (port) - 1024) / sm->port_per_thread];
  
    return next_worker_index;
  }
  
  static clib_error_t *
  snat_config (vlib_main_t * vm, unformat_input_t * input)
  {
    snat_main_t *sm = &snat_main;
    nat66_main_t *nm = &nat66_main;
    u32 translation_buckets = 1024;
    u32 translation_memory_size = 128 << 20;
    u32 user_buckets = 128;
    u32 user_memory_size = 64 << 20;
    u32 max_translations_per_user = 100;
    u32 outside_vrf_id = 0;
    u32 outside_ip6_vrf_id = 0;
    u32 inside_vrf_id = 0;
    u32 static_mapping_buckets = 1024;
    u32 static_mapping_memory_size = 64 << 20;
    u32 nat64_bib_buckets = 1024;
    u32 nat64_bib_memory_size = 128 << 20;
    u32 nat64_st_buckets = 2048;
    u32 nat64_st_memory_size = 256 << 20;
    u8 static_mapping_only = 0;
    u8 static_mapping_connection_tracking = 0;
    snat_main_per_thread_data_t *tsm;
    dslite_main_t *dm = &dslite_main;
  
    sm->deterministic = 0;
    sm->out2in_dpo = 0;
    sm->endpoint_dependent = 0;
  
    while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
      {
        if (unformat
  	  (input, "translation hash buckets %d", &translation_buckets))
  	;
        else if (unformat (input, "translation hash memory %d",
  			 &translation_memory_size));
        else if (unformat (input, "user hash buckets %d", &user_buckets))
  	;
        else if (unformat (input, "user hash memory %d", &user_memory_size))
  	;
        else if (unformat (input, "max translations per user %d",
  			 &max_translations_per_user))
  	;
        else if (unformat (input, "outside VRF id %d", &outside_vrf_id))
  	;
        else if (unformat (input, "outside ip6 VRF id %d", &outside_ip6_vrf_id))
  	;
        else if (unformat (input, "inside VRF id %d", &inside_vrf_id))
  	;
        else if (unformat (input, "static mapping only"))
  	{
  	  static_mapping_only = 1;
  	  if (unformat (input, "connection tracking"))
  	    static_mapping_connection_tracking = 1;
  	}
        else if (unformat (input, "deterministic"))
  	sm->deterministic = 1;
        else if (unformat (input, "nat64 bib hash buckets %d",
  			 &nat64_bib_buckets))
  	;
        else if (unformat (input, "nat64 bib hash memory %d",
  			 &nat64_bib_memory_size))
  	;
        else
  	if (unformat (input, "nat64 st hash buckets %d", &nat64_st_buckets))
  	;
        else if (unformat (input, "nat64 st hash memory %d",
  			 &nat64_st_memory_size))
  	;
        else if (unformat (input, "out2in dpo"))
  	sm->out2in_dpo = 1;
        else if (unformat (input, "dslite ce"))
  	dslite_set_ce (dm, 1);
        else if (unformat (input, "endpoint-dependent"))
  	sm->endpoint_dependent = 1;
        else
  	return clib_error_return (0, "unknown input '%U'",
  				  format_unformat_error, input);
      }
  
    if (sm->deterministic && sm->endpoint_dependent)
      return clib_error_return (0,
  			      "deterministic and endpoint-dependent modes are mutually exclusive");
  
    if (static_mapping_only && (sm->deterministic || sm->endpoint_dependent))
      return clib_error_return (0,
  			      "static mapping only mode available only for simple nat");
  
    if (sm->out2in_dpo && (sm->deterministic || sm->endpoint_dependent))
      return clib_error_return (0,
  			      "out2in dpo mode available only for simple nat");
  
    /* for show commands, etc. */
    sm->translation_buckets = translation_buckets;
    sm->translation_memory_size = translation_memory_size;
    /* do not exceed load factor 10 */
    sm->max_translations = 10 * translation_buckets;
    sm->user_buckets = user_buckets;
    sm->user_memory_size = user_memory_size;
    sm->max_translations_per_user = max_translations_per_user;
    sm->outside_vrf_id = outside_vrf_id;
    sm->outside_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
  							     outside_vrf_id,
  							     FIB_SOURCE_PLUGIN_HI);
    nm->outside_vrf_id = outside_ip6_vrf_id;
    nm->outside_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP6,
  							     outside_ip6_vrf_id,
  							     FIB_SOURCE_PLUGIN_HI);
    sm->inside_vrf_id = inside_vrf_id;
    sm->inside_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
  							    inside_vrf_id,
  							    FIB_SOURCE_PLUGIN_HI);
    sm->static_mapping_only = static_mapping_only;
    sm->static_mapping_connection_tracking = static_mapping_connection_tracking;
  
    nat64_set_hash (nat64_bib_buckets, nat64_bib_memory_size, nat64_st_buckets,
  		  nat64_st_memory_size);
  
    if (sm->deterministic)
      {
        sm->in2out_node_index = snat_det_in2out_node.index;
        sm->in2out_output_node_index = ~0;
        sm->out2in_node_index = snat_det_out2in_node.index;
        sm->icmp_match_in2out_cb = icmp_match_in2out_det;
        sm->icmp_match_out2in_cb = icmp_match_out2in_det;
      }
    else
      {
        if (sm->endpoint_dependent)
  	{
  	  sm->worker_in2out_cb = snat_get_worker_in2out_cb;
  	  sm->worker_out2in_cb = nat44_ed_get_worker_out2in_cb;
  	  sm->in2out_node_index = nat44_ed_in2out_node.index;
  	  sm->in2out_output_node_index = nat44_ed_in2out_output_node.index;
  	  sm->out2in_node_index = nat44_ed_out2in_node.index;
  	  sm->icmp_match_in2out_cb = icmp_match_in2out_ed;
  	  sm->icmp_match_out2in_cb = icmp_match_out2in_ed;
  	  nat_affinity_init (vm);
  	}
        else
  	{
  	  sm->worker_in2out_cb = snat_get_worker_in2out_cb;
  	  sm->worker_out2in_cb = snat_get_worker_out2in_cb;
  	  sm->in2out_node_index = snat_in2out_node.index;
  	  sm->in2out_output_node_index = snat_in2out_output_node.index;
  	  sm->out2in_node_index = snat_out2in_node.index;
  	  sm->icmp_match_in2out_cb = icmp_match_in2out_slow;
  	  sm->icmp_match_out2in_cb = icmp_match_out2in_slow;
  	}
        if (!static_mapping_only ||
  	  (static_mapping_only && static_mapping_connection_tracking))
  	{
            /* *INDENT-OFF* */
            vec_foreach (tsm, sm->per_thread_data)
              {
                if (sm->endpoint_dependent)
                  {
                    clib_bihash_init_16_8 (&tsm->in2out_ed, "in2out-ed",
                                           translation_buckets,
                                           translation_memory_size);
                    clib_bihash_set_kvp_format_fn_16_8 (&tsm->in2out_ed,
                                                        format_ed_session_kvp);
  
                    clib_bihash_init_16_8 (&tsm->out2in_ed, "out2in-ed",
                                           translation_buckets,
                                           translation_memory_size);
                    clib_bihash_set_kvp_format_fn_16_8 (&tsm->out2in_ed,
                                                        format_ed_session_kvp);
                  }
                else
                  {
                    clib_bihash_init_8_8 (&tsm->in2out, "in2out",
                                          translation_buckets,
                                          translation_memory_size);
                    clib_bihash_set_kvp_format_fn_8_8 (&tsm->in2out,
                                                       format_session_kvp);
  
                    clib_bihash_init_8_8 (&tsm->out2in, "out2in",
                                          translation_buckets,
                                          translation_memory_size);
                    clib_bihash_set_kvp_format_fn_8_8 (&tsm->out2in,
                                                       format_session_kvp);
                  }
  
                clib_bihash_init_8_8 (&tsm->user_hash, "users", user_buckets,
                                      user_memory_size);
                clib_bihash_set_kvp_format_fn_8_8 (&tsm->user_hash,
                                                   format_user_kvp);
              }
            /* *INDENT-ON* */
  
  	}
        else
  	{
  	  sm->icmp_match_in2out_cb = icmp_match_in2out_fast;
  	  sm->icmp_match_out2in_cb = icmp_match_out2in_fast;
  	}
        clib_bihash_init_8_8 (&sm->static_mapping_by_local,
  			    "static_mapping_by_local", static_mapping_buckets,
  			    static_mapping_memory_size);
        clib_bihash_set_kvp_format_fn_8_8 (&sm->static_mapping_by_local,
  					 format_static_mapping_kvp);
  
        clib_bihash_init_8_8 (&sm->static_mapping_by_external,
  			    "static_mapping_by_external",
  			    static_mapping_buckets,
  			    static_mapping_memory_size);
        clib_bihash_set_kvp_format_fn_8_8 (&sm->static_mapping_by_external,
  					 format_static_mapping_kvp);
      }
  
    return 0;
  }
  
  VLIB_CONFIG_FUNCTION (snat_config, "nat");
  
  static void
  nat_ip4_add_del_addr_only_sm_cb (ip4_main_t * im,
  				 uword opaque,
  				 u32 sw_if_index,
  				 ip4_address_t * address,
  				 u32 address_length,
  				 u32 if_address_index, u32 is_delete)
  {
    snat_main_t *sm = &snat_main;
    snat_static_map_resolve_t *rp;
    snat_static_mapping_t *m;
    snat_session_key_t m_key;
    clib_bihash_kv_8_8_t kv, value;
    int i, rv;
    ip4_address_t l_addr;
  
    for (i = 0; i < vec_len (sm->to_resolve); i++)
      {
        rp = sm->to_resolve + i;
        if (rp->addr_only == 0)
  	continue;
        if (rp->sw_if_index == sw_if_index)
  	goto match;
      }
  
    return;
  
  match:
    m_key.addr.as_u32 = address->as_u32;
    m_key.port = rp->addr_only ? 0 : rp->e_port;
    m_key.protocol = rp->addr_only ? 0 : rp->proto;
    m_key.fib_index = sm->outside_fib_index;
    kv.key = m_key.as_u64;
    if (clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv, &value))
      m = 0;
    else
      m = pool_elt_at_index (sm->static_mappings, value.value);
  
    if (!is_delete)
      {
        /* Don't trip over lease renewal, static config */
        if (m)
  	return;
      }
    else
      {
        if (!m)
  	return;
      }
  
    /* Indetity mapping? */
    if (rp->l_addr.as_u32 == 0)
      l_addr.as_u32 = address[0].as_u32;
    else
      l_addr.as_u32 = rp->l_addr.as_u32;
    /* Add the static mapping */
    rv = snat_add_static_mapping (l_addr,
  				address[0],
  				rp->l_port,
  				rp->e_port,
  				rp->vrf_id,
  				rp->addr_only, ~0 /* sw_if_index */ ,
  				rp->proto, !is_delete, rp->twice_nat,
  				rp->out2in_only, rp->tag, rp->identity_nat);
    if (rv)
      nat_log_notice ("snat_add_static_mapping returned %d", rv);
  }
  
  static void
  snat_ip4_add_del_interface_address_cb (ip4_main_t * im,
  				       uword opaque,
  				       u32 sw_if_index,
  				       ip4_address_t * address,
  				       u32 address_length,
  				       u32 if_address_index, u32 is_delete)
  {
    snat_main_t *sm = &snat_main;
    snat_static_map_resolve_t *rp;
    ip4_address_t l_addr;
    int i, j;
    int rv;
    u8 twice_nat = 0;
    snat_address_t *addresses = sm->addresses;
  
    for (i = 0; i < vec_len (sm->auto_add_sw_if_indices); i++)
      {
        if (sw_if_index == sm->auto_add_sw_if_indices[i])
  	goto match;
      }
  
    for (i = 0; i < vec_len (sm->auto_add_sw_if_indices_twice_nat); i++)
      {
        twice_nat = 1;
        addresses = sm->twice_nat_addresses;
        if (sw_if_index == sm->auto_add_sw_if_indices_twice_nat[i])
  	goto match;
      }
  
    return;
  
  match:
    if (!is_delete)
      {
        /* Don't trip over lease renewal, static config */
        for (j = 0; j < vec_len (addresses); j++)
  	if (addresses[j].addr.as_u32 == address->as_u32)
  	  return;
  
        (void) snat_add_address (sm, address, ~0, twice_nat);
        /* Scan static map resolution vector */
        for (j = 0; j < vec_len (sm->to_resolve); j++)
  	{
  	  rp = sm->to_resolve + j;
  	  if (rp->addr_only)
  	    continue;
  	  /* On this interface? */
  	  if (rp->sw_if_index == sw_if_index)
  	    {
  	      /* Indetity mapping? */
  	      if (rp->l_addr.as_u32 == 0)
  		l_addr.as_u32 = address[0].as_u32;
  	      else
  		l_addr.as_u32 = rp->l_addr.as_u32;
  	      /* Add the static mapping */
  	      rv = snat_add_static_mapping (l_addr,
  					    address[0],
  					    rp->l_port,
  					    rp->e_port,
  					    rp->vrf_id,
  					    rp->addr_only,
  					    ~0 /* sw_if_index */ ,
  					    rp->proto,
  					    rp->is_add, rp->twice_nat,
  					    rp->out2in_only, rp->tag,
  					    rp->identity_nat);
  	      if (rv)
  		nat_log_notice ("snat_add_static_mapping returned %d", rv);
  	    }
  	}
        return;
      }
    else
      {
        (void) snat_del_address (sm, address[0], 1, twice_nat);
        return;
      }
  }
  
  
  int
  snat_add_interface_address (snat_main_t * sm, u32 sw_if_index, int is_del,
  			    u8 twice_nat)
  {
    ip4_main_t *ip4_main = sm->ip4_main;
    ip4_address_t *first_int_addr;
    snat_static_map_resolve_t *rp;
    u32 *indices_to_delete = 0;
    int i, j;
    u32 *auto_add_sw_if_indices =
      twice_nat ? sm->
      auto_add_sw_if_indices_twice_nat : sm->auto_add_sw_if_indices;
  
    first_int_addr = ip4_interface_first_address (ip4_main, sw_if_index, 0	/* just want the address */
      );
  
    for (i = 0; i < vec_len (auto_add_sw_if_indices); i++)
      {
        if (auto_add_sw_if_indices[i] == sw_if_index)
  	{
  	  if (is_del)
  	    {
  	      /* if have address remove it */
  	      if (first_int_addr)
  		(void) snat_del_address (sm, first_int_addr[0], 1, twice_nat);
  	      else
  		{
  		  for (j = 0; j < vec_len (sm->to_resolve); j++)
  		    {
  		      rp = sm->to_resolve + j;
  		      if (rp->sw_if_index == sw_if_index)
  			vec_add1 (indices_to_delete, j);
  		    }
  		  if (vec_len (indices_to_delete))
  		    {
  		      for (j = vec_len (indices_to_delete) - 1; j >= 0; j--)
  			vec_del1 (sm->to_resolve, j);
  		      vec_free (indices_to_delete);
  		    }
  		}
  	      if (twice_nat)
  		vec_del1 (sm->auto_add_sw_if_indices_twice_nat, i);
  	      else
  		vec_del1 (sm->auto_add_sw_if_indices, i);
  	    }
  	  else
  	    return VNET_API_ERROR_VALUE_EXIST;
  
  	  return 0;
  	}
      }
  
    if (is_del)
      return VNET_API_ERROR_NO_SUCH_ENTRY;
  
    /* add to the auto-address list */
    if (twice_nat)
      vec_add1 (sm->auto_add_sw_if_indices_twice_nat, sw_if_index);
    else
      vec_add1 (sm->auto_add_sw_if_indices, sw_if_index);
  
    /* If the address is already bound - or static - add it now */
    if (first_int_addr)
      (void) snat_add_address (sm, first_int_addr, ~0, twice_nat);
  
    return 0;
  }
  
  int
  nat44_del_session (snat_main_t * sm, ip4_address_t * addr, u16 port,
  		   snat_protocol_t proto, u32 vrf_id, int is_in)
  {
    snat_main_per_thread_data_t *tsm;
    clib_bihash_kv_8_8_t kv, value;
    ip4_header_t ip;
    u32 fib_index = fib_table_find (FIB_PROTOCOL_IP4, vrf_id);
    snat_session_key_t key;
    snat_session_t *s;
    clib_bihash_8_8_t *t;
  
    if (sm->endpoint_dependent)
      return VNET_API_ERROR_UNSUPPORTED;
  
    ip.dst_address.as_u32 = ip.src_address.as_u32 = addr->as_u32;
    if (sm->num_workers > 1)
      tsm =
        vec_elt_at_index (sm->per_thread_data,
  			sm->worker_in2out_cb (&ip, fib_index));
    else
      tsm = vec_elt_at_index (sm->per_thread_data, sm->num_workers);
  
    key.addr.as_u32 = addr->as_u32;
    key.port = clib_host_to_net_u16 (port);
    key.protocol = proto;
    key.fib_index = fib_index;
    kv.key = key.as_u64;
    t = is_in ? &tsm->in2out : &tsm->out2in;
    if (!clib_bihash_search_8_8 (t, &kv, &value))
      {
        if (pool_is_free_index (tsm->sessions, value.value))
  	return VNET_API_ERROR_UNSPECIFIED;
  
        s = pool_elt_at_index (tsm->sessions, value.value);
        nat_free_session_data (sm, s, tsm - sm->per_thread_data);
        nat44_delete_session (sm, s, tsm - sm->per_thread_data);
        return 0;
      }
  
    return VNET_API_ERROR_NO_SUCH_ENTRY;
  }
  
  int
  nat44_del_ed_session (snat_main_t * sm, ip4_address_t * addr, u16 port,
  		      ip4_address_t * eh_addr, u16 eh_port, u8 proto,
  		      u32 vrf_id, int is_in)
  {
    ip4_header_t ip;
    clib_bihash_16_8_t *t;
    nat_ed_ses_key_t key;
    clib_bihash_kv_16_8_t kv, value;
    u32 fib_index = fib_table_find (FIB_PROTOCOL_IP4, vrf_id);
    snat_session_t *s;
    snat_main_per_thread_data_t *tsm;
  
    if (!sm->endpoint_dependent)
      return VNET_API_ERROR_FEATURE_DISABLED;
  
    ip.dst_address.as_u32 = ip.src_address.as_u32 = addr->as_u32;
    if (sm->num_workers > 1)
      tsm =
        vec_elt_at_index (sm->per_thread_data,
  			sm->worker_in2out_cb (&ip, fib_index));
    else
      tsm = vec_elt_at_index (sm->per_thread_data, sm->num_workers);
  
    t = is_in ? &tsm->in2out_ed : &tsm->out2in_ed;
    key.l_addr.as_u32 = addr->as_u32;
    key.r_addr.as_u32 = eh_addr->as_u32;
    key.l_port = clib_host_to_net_u16 (port);
    key.r_port = clib_host_to_net_u16 (eh_port);
    key.proto = proto;
    key.fib_index = fib_index;
    kv.key[0] = key.as_u64[0];
    kv.key[1] = key.as_u64[1];
    if (clib_bihash_search_16_8 (t, &kv, &value))
      return VNET_API_ERROR_NO_SUCH_ENTRY;
  
    if (pool_is_free_index (tsm->sessions, value.value))
      return VNET_API_ERROR_UNSPECIFIED;
    s = pool_elt_at_index (tsm->sessions, value.value);
    nat_free_session_data (sm, s, tsm - sm->per_thread_data);
    nat44_delete_session (sm, s, tsm - sm->per_thread_data);
    return 0;
  }
  
  void
  nat_set_alloc_addr_and_port_mape (u16 psid, u16 psid_offset, u16 psid_length)
  {
    snat_main_t *sm = &snat_main;
  
    sm->addr_and_port_alloc_alg = NAT_ADDR_AND_PORT_ALLOC_ALG_MAPE;
    sm->alloc_addr_and_port = nat_alloc_addr_and_port_mape;
    sm->psid = psid;
    sm->psid_offset = psid_offset;
    sm->psid_length = psid_length;
  }
  
  void
  nat_set_alloc_addr_and_port_range (u16 start_port, u16 end_port)
  {
    snat_main_t *sm = &snat_main;
  
    sm->addr_and_port_alloc_alg = NAT_ADDR_AND_PORT_ALLOC_ALG_RANGE;
    sm->alloc_addr_and_port = nat_alloc_addr_and_port_range;
    sm->start_port = start_port;
    sm->end_port = end_port;
  }
  
  void
  nat_set_alloc_addr_and_port_default (void)
  {
    snat_main_t *sm = &snat_main;
  
    sm->addr_and_port_alloc_alg = NAT_ADDR_AND_PORT_ALLOC_ALG_DEFAULT;
    sm->alloc_addr_and_port = nat_alloc_addr_and_port_default;
  }
  
  /*
   * fd.io coding-style-patch-verification: ON
   *
   * Local Variables:
   * eval: (c-set-style "gnu")
   * End:
   */
  