nat: Final NAT44 EI/ED split patch

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

Type: refactor

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

1 files changed, 0 insertions, 1558 deletions

diff --git a/src/plugins/nat/nat.h b/src/plugins/nat/nat.h
deleted file mode 100644
index c1dc31e8710..00000000000
--- a/src/plugins/nat/nat.h
+++ /dev/null
@@ -1,1558 +0,0 @@
-/*
- * Copyright (c) 2020 Cisco and/or its affiliates.
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at:
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-/**
- * @file nat.c
- * NAT plugin global declarations
- */
-#ifndef __included_nat_h__
-#define __included_nat_h__
-
-#include <vnet/vnet.h>
-#include <vnet/ip/ip.h>
-#include <vnet/ethernet/ethernet.h>
-#include <vnet/ip/icmp46_packet.h>
-#include <vnet/api_errno.h>
-#include <vnet/fib/fib_source.h>
-#include <vppinfra/elog.h>
-#include <vppinfra/bihash_8_8.h>
-#include <vppinfra/bihash_16_8.h>
-#include <vppinfra/dlist.h>
-#include <vppinfra/error.h>
-#include <vlibapi/api.h>
-#include <vlib/log.h>
-#include <vppinfra/bihash_16_8.h>
-#include <nat/lib/lib.h>
-#include <nat/lib/inlines.h>
-
-/* default number of worker handoff frame queue elements */
-#define NAT_FQ_NELTS_DEFAULT 64
-
-/* NAT buffer flags */
-#define SNAT_FLAG_HAIRPINNING (1 << 0)
-
-/* NAT44 API Configuration flags */
-#define foreach_nat44_config_flag  \
-  _(0x00, IS_ENDPOINT_INDEPENDENT) \
-  _(0x01, IS_ENDPOINT_DEPENDENT)   \
-  _(0x02, IS_STATIC_MAPPING_ONLY)  \
-  _(0x04, IS_CONNECTION_TRACKING)  \
-  _(0x08, IS_OUT2IN_DPO)
-
-typedef enum nat44_config_flags_t_
-{
-#define _(n,f) NAT44_API_##f = n,
-  foreach_nat44_config_flag
-#undef _
-} nat44_config_flags_t;
-
-typedef struct
-{
-  /* nat44 plugin features */
-  u8 static_mapping_only;
-  u8 connection_tracking;
-  u8 endpoint_dependent;
-  u8 out2in_dpo;
-
-  u32 inside_vrf;
-  u32 outside_vrf;
-
-  /* maximum number of users */
-  u32 users;
-
-  /* maximum number of sessions */
-  u32 sessions;
-
-  /* maximum number of ssessions per user */
-  u32 user_sessions;
-} nat44_config_t;
-
-typedef enum
-{
-  NAT_NEXT_DROP,
-  NAT_NEXT_ICMP_ERROR,
-  NAT_NEXT_IN2OUT_ED_FAST_PATH,
-  NAT_NEXT_IN2OUT_ED_SLOW_PATH,
-  NAT_NEXT_IN2OUT_ED_OUTPUT_FAST_PATH,
-  NAT_NEXT_IN2OUT_ED_OUTPUT_SLOW_PATH,
-  NAT_NEXT_OUT2IN_ED_FAST_PATH,
-  NAT_NEXT_OUT2IN_ED_SLOW_PATH,
-  NAT_NEXT_IN2OUT_CLASSIFY,
-  NAT_NEXT_OUT2IN_CLASSIFY,
-  NAT_N_NEXT,
-} nat_next_t;
-
-typedef struct
-{
-  u32 next_index;
-  u32 arc_next_index;
-} nat_pre_trace_t;
-
-/* user (internal host) key */
-typedef struct
-{
-  union
-  {
-    struct
-    {
-      ip4_address_t addr;
-      u32 fib_index;
-    };
-    u64 as_u64;
-  };
-} snat_user_key_t;
-
-/* External address and port allocation modes */
-#define foreach_nat_addr_and_port_alloc_alg \
-  _(0, DEFAULT, "default")         \
-  _(1, MAPE, "map-e")              \
-  _(2, RANGE, "port-range")
-
-typedef enum
-{
-#define _(v, N, s) NAT_ADDR_AND_PORT_ALLOC_ALG_##N = v,
-  foreach_nat_addr_and_port_alloc_alg
-#undef _
-} nat_addr_and_port_alloc_alg_t;
-
-/* Session state */
-#define foreach_snat_session_state          \
-  _(0, UNKNOWN, "unknown")                 \
-  _(1, UDP_ACTIVE, "udp-active")           \
-  _(2, TCP_SYN_SENT, "tcp-syn-sent")       \
-  _(3, TCP_ESTABLISHED, "tcp-established") \
-  _(4, TCP_FIN_WAIT, "tcp-fin-wait")       \
-  _(5, TCP_CLOSE_WAIT, "tcp-close-wait")   \
-  _(6, TCP_CLOSING, "tcp-closing")         \
-  _(7, TCP_LAST_ACK, "tcp-last-ack")       \
-  _(8, TCP_CLOSED, "tcp-closed")           \
-  _(9, ICMP_ACTIVE, "icmp-active")
-
-typedef enum
-{
-#define _(v, N, s) SNAT_SESSION_##N = v,
-  foreach_snat_session_state
-#undef _
-} snat_session_state_t;
-
-#define foreach_nat_in2out_ed_error                     \
-_(UNSUPPORTED_PROTOCOL, "unsupported protocol")         \
-_(OUT_OF_PORTS, "out of ports")                         \
-_(BAD_ICMP_TYPE, "unsupported ICMP type")               \
-_(MAX_SESSIONS_EXCEEDED, "maximum sessions exceeded")   \
-_(NON_SYN, "non-SYN packet try to create session")      \
-_(TCP_CLOSED, "drops due to TCP in transitory timeout")
-
-typedef enum
-{
-#define _(sym,str) NAT_IN2OUT_ED_ERROR_##sym,
-  foreach_nat_in2out_ed_error
-#undef _
-    NAT_IN2OUT_ED_N_ERROR,
-} nat_in2out_ed_error_t;
-
-#define foreach_nat_out2in_ed_error                                           \
-  _ (UNSUPPORTED_PROTOCOL, "unsupported protocol")                            \
-  _ (OUT_OF_PORTS, "out of ports")                                            \
-  _ (BAD_ICMP_TYPE, "unsupported ICMP type")                                  \
-  _ (NO_TRANSLATION, "no translation")                                        \
-  _ (MAX_SESSIONS_EXCEEDED, "maximum sessions exceeded")                      \
-  _ (MAX_USER_SESS_EXCEEDED, "max user sessions exceeded")                    \
-  _ (CANNOT_CREATE_USER, "cannot create NAT user")                            \
-  _ (NON_SYN, "non-SYN packet try to create session")                         \
-  _ (TCP_CLOSED, "drops due to TCP in transitory timeout")                    \
-  _ (HASH_ADD_FAILED, "hash table add failed")
-
-typedef enum
-{
-#define _(sym,str) NAT_OUT2IN_ED_ERROR_##sym,
-  foreach_nat_out2in_ed_error
-#undef _
-    NAT_OUT2IN_ED_N_ERROR,
-} nat_out2in_ed_error_t;
-
-
-/* Endpoint dependent TCP session state */
-#define NAT44_SES_I2O_FIN 1
-#define NAT44_SES_O2I_FIN 2
-#define NAT44_SES_I2O_FIN_ACK 4
-#define NAT44_SES_O2I_FIN_ACK 8
-#define NAT44_SES_I2O_SYN 16
-#define NAT44_SES_O2I_SYN 32
-#define NAT44_SES_RST     64
-
-/* Session flags */
-#define SNAT_SESSION_FLAG_STATIC_MAPPING     (1 << 0)
-#define SNAT_SESSION_FLAG_UNKNOWN_PROTO	     (1 << 1)
-#define SNAT_SESSION_FLAG_LOAD_BALANCING     (1 << 2)
-#define SNAT_SESSION_FLAG_TWICE_NAT	     (1 << 3)
-#define SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT (1 << 4)
-#define SNAT_SESSION_FLAG_FWD_BYPASS	     (1 << 5)
-#define SNAT_SESSION_FLAG_AFFINITY	     (1 << 6)
-#define SNAT_SESSION_FLAG_EXACT_ADDRESS	     (1 << 7)
-#define SNAT_SESSION_FLAG_HAIRPINNING	     (1 << 8)
-
-/* NAT interface flags */
-#define NAT_INTERFACE_FLAG_IS_INSIDE 1
-#define NAT_INTERFACE_FLAG_IS_OUTSIDE 2
-
-/* Static mapping flags */
-#define NAT_STATIC_MAPPING_FLAG_ADDR_ONLY      1
-#define NAT_STATIC_MAPPING_FLAG_OUT2IN_ONLY    2
-#define NAT_STATIC_MAPPING_FLAG_IDENTITY_NAT   4
-#define NAT_STATIC_MAPPING_FLAG_LB             8
-#define NAT_STATIC_MAPPING_FLAG_EXACT_ADDRESS  16
-
-/* *INDENT-OFF* */
-typedef CLIB_PACKED(struct
-{
-  // number of sessions in this vrf
-  u32 ses_count;
-
-  u32 rx_fib_index;
-  u32 tx_fib_index;
-
-  // is this vrf expired
-  u8 expired;
-}) per_vrf_sessions_t;
-/* *INDENT-ON* */
-
-typedef struct
-{
-  ip4_address_t saddr, daddr;
-  u32 fib_index;
-  u16 sport, dport;
-  u16 icmp_id;
-  u8 proto;
-} nat_6t_t;
-
-typedef struct
-{
-#define NAT_FLOW_OP_SADDR_REWRITE   (1 << 1)
-#define NAT_FLOW_OP_SPORT_REWRITE   (1 << 2)
-#define NAT_FLOW_OP_DADDR_REWRITE   (1 << 3)
-#define NAT_FLOW_OP_DPORT_REWRITE   (1 << 4)
-#define NAT_FLOW_OP_ICMP_ID_REWRITE (1 << 5)
-#define NAT_FLOW_OP_TXFIB_REWRITE   (1 << 6)
-  int ops;
-  nat_6t_t match;
-  nat_6t_t rewrite;
-  uword l3_csum_delta;
-  uword l4_csum_delta;
-} nat_6t_flow_t;
-
-always_inline void
-nat_6t_flow_saddr_rewrite_set (nat_6t_flow_t *f, u32 saddr)
-{
-  f->ops |= NAT_FLOW_OP_SADDR_REWRITE;
-  f->rewrite.saddr.as_u32 = saddr;
-}
-
-always_inline void
-nat_6t_flow_daddr_rewrite_set (nat_6t_flow_t *f, u32 daddr)
-{
-  f->ops |= NAT_FLOW_OP_DADDR_REWRITE;
-  f->rewrite.daddr.as_u32 = daddr;
-}
-
-always_inline void
-nat_6t_flow_sport_rewrite_set (nat_6t_flow_t *f, u32 sport)
-{
-  f->ops |= NAT_FLOW_OP_SPORT_REWRITE;
-  f->rewrite.sport = sport;
-}
-
-always_inline void
-nat_6t_flow_dport_rewrite_set (nat_6t_flow_t *f, u32 dport)
-{
-  f->ops |= NAT_FLOW_OP_DPORT_REWRITE;
-  f->rewrite.dport = dport;
-}
-
-always_inline void
-nat_6t_flow_txfib_rewrite_set (nat_6t_flow_t *f, u32 tx_fib_index)
-{
-  f->ops |= NAT_FLOW_OP_TXFIB_REWRITE;
-  f->rewrite.fib_index = tx_fib_index;
-}
-
-always_inline void
-nat_6t_flow_icmp_id_rewrite_set (nat_6t_flow_t *f, u16 id)
-{
-  f->ops |= NAT_FLOW_OP_ICMP_ID_REWRITE;
-  f->rewrite.icmp_id = id;
-}
-
-/* *INDENT-OFF* */
-typedef CLIB_PACKED(struct
-{
-  /* Outside network tuple */
-  struct
-  {
-    ip4_address_t addr;
-    u32 fib_index;
-    u16 port;
-  } out2in;
-
-  /* Inside network tuple */
-  struct
-  {
-    ip4_address_t addr;
-    u32 fib_index;
-    u16 port;
-  } in2out;
-
-  nat_protocol_t nat_proto;
-
-  nat_6t_flow_t i2o;
-  nat_6t_flow_t o2i;
-
-  /* Flags */
-  u32 flags;
-
-  /* Per-user translations */
-  u32 per_user_index;
-  u32 per_user_list_head_index;
-
-  /* head of LRU list in which this session is tracked */
-  u32 lru_head_index;
-  /* index in global LRU list */
-  u32 lru_index;
-  f64 last_lru_update;
-
-  /* Last heard timer */
-  f64 last_heard;
-
-  /* Last HA refresh */
-  f64 ha_last_refreshed;
-
-  /* Counters */
-  u64 total_bytes;
-  u32 total_pkts;
-
-  /* External host address and port */
-  ip4_address_t ext_host_addr;
-  u16 ext_host_port;
-
-  /* External host address and port after translation */
-  ip4_address_t ext_host_nat_addr;
-  u16 ext_host_nat_port;
-
-  /* TCP session state */
-  u8 state;
-  u32 i2o_fin_seq;
-  u32 o2i_fin_seq;
-  u64 tcp_closed_timestamp;
-
-  /* user index */
-  u32 user_index;
-
-  /* per vrf sessions index */
-  u32 per_vrf_sessions_index;
-
-}) snat_session_t;
-/* *INDENT-ON* */
-
-typedef struct
-{
-  ip4_address_t addr;
-  u32 fib_index;
-  u32 sessions_per_user_list_head_index;
-  u32 nsessions;
-  u32 nstaticsessions;
-} snat_user_t;
-
-typedef struct
-{
-  ip4_address_t addr;
-  u32 fib_index;
-/* *INDENT-OFF* */
-#define _(N, i, n, s) \
-  u32 busy_##n##_ports; \
-  u32 * busy_##n##_ports_per_thread; \
-  u32 busy_##n##_port_refcounts[65535];
-  foreach_nat_protocol
-#undef _
-/* *INDENT-ON* */
-} snat_address_t;
-
-typedef struct
-{
-  u32 fib_index;
-  u32 ref_count;
-} nat_fib_t;
-
-typedef struct
-{
-  u32 fib_index;
-  u32 refcount;
-} nat_outside_fib_t;
-
-typedef struct
-{
-  /* backend IP address */
-  ip4_address_t addr;
-  /* backend port number */
-  u16 port;
-  /* probability of the backend to be randomly matched */
-  u8 probability;
-  u8 prefix;
-  /* backend FIB table */
-  u32 vrf_id;
-  u32 fib_index;
-} nat44_lb_addr_port_t;
-
-typedef enum
-{
-  /* twice-nat disabled */
-  TWICE_NAT_DISABLED,
-  /* twice-nat enabled */
-  TWICE_NAT,
-  /* twice-nat only when src IP equals dst IP after translation */
-  TWICE_NAT_SELF,
-} twice_nat_type_t;
-
-typedef enum
-{
-  /* no load-balancing */
-  NO_LB_NAT,
-  /* load-balancing */
-  LB_NAT,
-  /* load-balancing with affinity */
-  AFFINITY_LB_NAT,
-} lb_nat_type_t;
-
-typedef struct
-{
-  /* prefered pool address */
-  ip4_address_t pool_addr;
-  /* local IP address */
-  ip4_address_t local_addr;
-  /* external IP address */
-  ip4_address_t external_addr;
-  /* local port */
-  u16 local_port;
-  /* external port */
-  u16 external_port;
-  /* is twice-nat */
-  twice_nat_type_t twice_nat;
-  /* local FIB table */
-  u32 vrf_id;
-  u32 fib_index;
-  /* protocol */
-  nat_protocol_t proto;
-  /* 0 = disabled, otherwise client IP affinity sticky time in seconds */
-  u32 affinity;
-  /* worker threads used by backends/local host */
-  u32 *workers;
-  /* opaque string tag */
-  u8 *tag;
-  /* backends for load-balancing mode */
-  nat44_lb_addr_port_t *locals;
-  /* affinity per service lis */
-  u32 affinity_per_service_list_head_index;
-  /* flags */
-  u32 flags;
-} snat_static_mapping_t;
-
-typedef struct
-{
-  u32 sw_if_index;
-  u8 flags;
-} snat_interface_t;
-
-typedef struct
-{
-  ip4_address_t l_addr;
-  ip4_address_t pool_addr;
-  u16 l_port;
-  u16 e_port;
-  u32 sw_if_index;
-  u32 vrf_id;
-  nat_protocol_t proto;
-  u32 flags;
-  int addr_only;
-  int twice_nat;
-  int out2in_only;
-  int identity_nat;
-  int exact;
-  u8 *tag;
-} snat_static_map_resolve_t;
-
-typedef struct
-{
-  /* Find-a-user => src address lookup */
-  clib_bihash_8_8_t user_hash;
-
-  /* User pool */
-  snat_user_t *users;
-
-  /* Session pool */
-  snat_session_t *sessions;
-
-  /* Pool of doubly-linked list elements */
-  dlist_elt_t *list_pool;
-
-  /* LRU session list - head is stale, tail is fresh */
-  dlist_elt_t *lru_pool;
-  u32 tcp_trans_lru_head_index;
-  u32 tcp_estab_lru_head_index;
-  u32 udp_lru_head_index;
-  u32 icmp_lru_head_index;
-  u32 unk_proto_lru_head_index;
-
-  /* NAT thread index */
-  u32 snat_thread_index;
-
-  /* real thread index */
-  u32 thread_index;
-
-  per_vrf_sessions_t *per_vrf_sessions_vec;
-
-} snat_main_per_thread_data_t;
-
-struct snat_main_s;
-
-/* ICMP session match function */
-typedef u32 (snat_icmp_match_function_t) (
-  struct snat_main_s *sm, vlib_node_runtime_t *node, u32 thread_index,
-  vlib_buffer_t *b0, ip4_header_t *ip0, ip4_address_t *addr, u16 *port,
-  u32 *fib_index, nat_protocol_t *proto, snat_session_t **s_out,
-  u8 *dont_translate);
-
-/* Return worker thread index for given packet */
-typedef u32 (snat_get_worker_in2out_function_t) (ip4_header_t * ip,
-						 u32 rx_fib_index,
-						 u8 is_output);
-
-typedef u32 (snat_get_worker_out2in_function_t) (vlib_buffer_t * b,
-						 ip4_header_t * ip,
-						 u32 rx_fib_index,
-						 u8 is_output);
-
-/* NAT address and port allocation function */
-typedef int (nat_alloc_out_addr_and_port_function_t) (snat_address_t *
-						      addresses,
-						      u32 fib_index,
-						      u32 thread_index,
-						      nat_protocol_t proto,
-						      ip4_address_t * addr,
-						      u16 * port,
-						      u16 port_per_thread,
-						      u32 snat_thread_index);
-
-#define foreach_nat_counter _ (tcp) _ (udp) _ (icmp) _ (other) _ (drops)
-
-typedef struct snat_main_s
-{
-  /* ICMP session match functions */
-  snat_icmp_match_function_t *icmp_match_in2out_cb;
-  snat_icmp_match_function_t *icmp_match_out2in_cb;
-
-  /* Thread settings */
-  u32 num_workers;
-  u32 first_worker_index;
-  u32 *workers;
-  snat_get_worker_in2out_function_t *worker_in2out_cb;
-  snat_get_worker_out2in_function_t *worker_out2in_cb;
-  u16 port_per_thread;
-
-  /* Per thread data */
-  snat_main_per_thread_data_t *per_thread_data;
-
-  /* Find a static mapping by local */
-  clib_bihash_8_8_t static_mapping_by_local;
-
-  /* Find a static mapping by external */
-  clib_bihash_8_8_t static_mapping_by_external;
-
-  /* Static mapping pool */
-  snat_static_mapping_t *static_mappings;
-
-  /* Endpoint independent lookup tables */
-  clib_bihash_8_8_t in2out;
-  clib_bihash_8_8_t out2in;
-
-  /* Endpoint dependent lookup table */
-  clib_bihash_16_8_t flow_hash;
-
-  /* Interface pool */
-  snat_interface_t *interfaces;
-  snat_interface_t *output_feature_interfaces;
-
-  /* Vector of outside addresses */
-  snat_address_t *addresses;
-  /* Address and port allocation function */
-  nat_alloc_out_addr_and_port_function_t *alloc_addr_and_port;
-  /* Address and port allocation type */
-  nat_addr_and_port_alloc_alg_t addr_and_port_alloc_alg;
-  /* Port set parameters (MAP-E) */
-  u8 psid_offset;
-  u8 psid_length;
-  u16 psid;
-  /* Port range parameters */
-  u16 start_port;
-  u16 end_port;
-
-  /* vector of fibs */
-  nat_fib_t *fibs;
-
-  /* vector of outside fibs */
-  nat_outside_fib_t *outside_fibs;
-
-  /* Vector of twice NAT addresses for external hosts */
-  snat_address_t *twice_nat_addresses;
-
-  /* sw_if_indices whose intfc addresses should be auto-added */
-  u32 *auto_add_sw_if_indices;
-  u32 *auto_add_sw_if_indices_twice_nat;
-
-  /* vector of interface address static mappings to resolve. */
-  snat_static_map_resolve_t *to_resolve;
-
-  /* Randomize port allocation order */
-  u32 random_seed;
-
-  /* Worker handoff frame-queue index */
-  u32 fq_in2out_index;
-  u32 fq_in2out_output_index;
-  u32 fq_out2in_index;
-
-  /* node indexes */
-  u32 error_node_index;
-
-  /* handoff fq nodes  */
-  u32 handoff_out2in_index;
-  u32 handoff_in2out_index;
-  u32 handoff_in2out_output_index;
-
-  /* respect feature arc nodes */
-  u32 pre_out2in_node_index;
-  u32 pre_in2out_node_index;
-
-  u32 out2in_node_index;
-  u32 in2out_node_index;
-  u32 in2out_output_node_index;
-
-  u32 in2out_fast_node_index;
-  u32 in2out_slowpath_node_index;
-  u32 in2out_slowpath_output_node_index;
-  u32 out2in_fast_node_index;
-
-  u32 ei_out2in_node_index;
-  u32 ei_in2out_node_index;
-  u32 ei_in2out_output_node_index;
-
-  u32 ed_out2in_node_index;
-  u32 ed_in2out_node_index;
-  u32 ed_in2out_output_node_index;
-
-  u32 ed_in2out_slowpath_node_index;
-  u32 ed_out2in_slowpath_node_index;
-
-  u32 hairpinning_node_index;
-  u32 hairpin_dst_node_index;
-  u32 hairpin_src_node_index;
-
-  nat44_config_t rconfig;
-  //nat44_config_t cconfig;
-
-  /* If forwarding is enabled */
-  u8 forwarding_enabled;
-
-  /* Config parameters */
-  u8 endpoint_dependent;
-
-  u8 out2in_dpo;
-  /* static mapping config */
-  u8 static_mapping_only;
-  u8 static_mapping_connection_tracking;
-
-  /* Is translation memory size calculated or user defined */
-  u8 translation_memory_size_set;
-
-  u32 translation_buckets;
-  u32 max_translations_per_thread;
-  u32 *max_translations_per_fib;
-  u32 max_users_per_thread;
-  u32 user_buckets;
-  u32 max_translations_per_user;
-
-  u32 outside_vrf_id;
-  u32 outside_fib_index;
-  u32 inside_vrf_id;
-  u32 inside_fib_index;
-
-  nat_timeouts_t timeouts;
-
-  /* TCP MSS clamping */
-  u16 mss_clamping;
-
-  /* counters */
-  vlib_simple_counter_main_t total_users;
-  vlib_simple_counter_main_t total_sessions;
-  vlib_simple_counter_main_t user_limit_reached;
-
-#define _(x) vlib_simple_counter_main_t x;
-  struct
-  {
-    struct
-    {
-      struct
-      {
-	foreach_nat_counter;
-      } in2out;
-
-      struct
-      {
-	foreach_nat_counter;
-      } out2in;
-
-      struct
-      {
-	foreach_nat_counter;
-      } in2out_ed;
-
-      struct
-      {
-	foreach_nat_counter;
-      } out2in_ed;
-    } fastpath;
-
-    struct
-    {
-      struct
-      {
-	foreach_nat_counter;
-      } in2out;
-
-      struct
-      {
-	foreach_nat_counter;
-      } out2in;
-
-      struct
-      {
-	foreach_nat_counter;
-      } in2out_ed;
-
-      struct
-      {
-	foreach_nat_counter;
-      } out2in_ed;
-    } slowpath;
-
-    vlib_simple_counter_main_t hairpinning;
-  } counters;
-#undef _
-
-  /* API message ID base */
-  u16 msg_id_base;
-
-  /* log class */
-  vlib_log_class_t log_class;
-  /* logging level */
-  u8 log_level;
-
-  /* convenience */
-  api_main_t *api_main;
-  ip4_main_t *ip4_main;
-  ip_lookup_main_t *ip4_lookup_main;
-
-  fib_source_t fib_src_hi;
-  fib_source_t fib_src_low;
-
-  /* pat - dynamic mapping enabled or conneciton tracking */
-  u8 pat;
-
-  /* number of worker handoff frame queue elements */
-  u32 frame_queue_nelts;
-
-  /* nat44 plugin enabled */
-  u8 enabled;
-
-  vnet_main_t *vnet_main;
-
-  u32 nat44_in2out_hairpinning_finish_ip4_lookup_node_fq_index;
-  u32 nat44_in2out_hairpinning_finish_interface_output_node_fq_index;
-  u32 nat44_hairpinning_fq_index;
-  u32 snat_hairpin_dst_fq_index;
-} snat_main_t;
-
-typedef struct
-{
-  u32 thread_index;
-  f64 now;
-} nat44_is_idle_session_ctx_t;
-
-typedef struct
-{
-  u32 cached_sw_if_index;
-  u32 cached_ip4_address;
-} snat_runtime_t;
-
-extern snat_main_t snat_main;
-
-// nat pre ed next_node feature classification
-extern vlib_node_registration_t nat_default_node;
-extern vlib_node_registration_t nat_pre_in2out_node;
-extern vlib_node_registration_t nat_pre_out2in_node;
-
-extern vlib_node_registration_t snat_in2out_node;
-extern vlib_node_registration_t snat_in2out_output_node;
-extern vlib_node_registration_t snat_out2in_node;
-extern vlib_node_registration_t snat_in2out_worker_handoff_node;
-extern vlib_node_registration_t snat_in2out_output_worker_handoff_node;
-extern vlib_node_registration_t snat_out2in_worker_handoff_node;
-extern vlib_node_registration_t nat44_ed_in2out_node;
-extern vlib_node_registration_t nat44_ed_in2out_output_node;
-extern vlib_node_registration_t nat44_ed_out2in_node;
-
-extern fib_source_t nat_fib_src_hi;
-extern fib_source_t nat_fib_src_low;
-
-/* format functions */
-format_function_t format_snat_user;
-format_function_t format_snat_static_mapping;
-format_function_t format_snat_static_map_to_resolve;
-format_function_t format_snat_session;
-format_function_t format_snat_key;
-format_function_t format_static_mapping_key;
-format_function_t format_nat_protocol;
-format_function_t format_nat_addr_and_port_alloc_alg;
-/* unformat functions */
-unformat_function_t unformat_nat_protocol;
-
-/** \brief Check if SNAT session is created from static mapping.
-    @param s SNAT session
-    @return 1 if SNAT session is created from static mapping otherwise 0
-*/
-#define snat_is_session_static(s) (s->flags & SNAT_SESSION_FLAG_STATIC_MAPPING)
-
-/** \brief Check if SNAT session for unknown protocol.
-    @param s SNAT session
-    @return 1 if SNAT session for unknown protocol otherwise 0
-*/
-#define snat_is_unk_proto_session(s) (s->flags & SNAT_SESSION_FLAG_UNKNOWN_PROTO)
-
-/** \brief Check if NAT session is twice NAT.
-    @param s NAT session
-    @return 1 if NAT session is twice NAT
-*/
-#define is_twice_nat_session(s) (s->flags & SNAT_SESSION_FLAG_TWICE_NAT)
-
-/** \brief Check if NAT session is load-balancing.
-    @param s NAT session
-    @return 1 if NAT session is load-balancing
-*/
-#define is_lb_session(s) (s->flags & SNAT_SESSION_FLAG_LOAD_BALANCING)
-
-/** \brief Check if NAT session is forwarding bypass.
-    @param s NAT session
-    @return 1 if NAT session is load-balancing
-*/
-#define is_fwd_bypass_session(s) (s->flags & SNAT_SESSION_FLAG_FWD_BYPASS)
-
-/** \brief Check if NAT session is endpoint dependent.
-    @param s NAT session
-    @return 1 if NAT session is endpoint dependent
-*/
-#define is_ed_session(s) (s->flags & SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT)
-
-/** \brief Check if NAT session has affinity record.
-    @param s NAT session
-    @return 1 if NAT session has affinity record
-*/
-#define is_affinity_sessions(s) (s->flags & SNAT_SESSION_FLAG_AFFINITY)
-
-/** \brief Check if exact pool address should be used.
-    @param s SNAT session
-    @return 1 if exact pool address or 0
-*/
-#define is_exact_address_session(s) (s->flags & SNAT_SESSION_FLAG_EXACT_ADDRESS)
-
-/** \brief Check if NAT interface is inside.
-    @param i NAT interface
-    @return 1 if inside interface
-*/
-#define nat_interface_is_inside(i) i->flags & NAT_INTERFACE_FLAG_IS_INSIDE
-
-/** \brief Check if NAT interface is outside.
-    @param i NAT interface
-    @return 1 if outside interface
-*/
-#define nat_interface_is_outside(i) i->flags & NAT_INTERFACE_FLAG_IS_OUTSIDE
-
-/** \brief Check if NAT44 endpoint-dependent TCP session is closed.
-    @param s NAT session
-    @return 1 if session is closed
-*/
-#define nat44_is_ses_closed(s) s->state == 0xf
-
-/** \brief Check if NAT static mapping is address only (1:1NAT).
-    @param sm NAT static mapping
-    @return 1 if 1:1NAT, 0 if 1:1NAPT
-*/
-#define is_addr_only_static_mapping(sm) (sm->flags & NAT_STATIC_MAPPING_FLAG_ADDR_ONLY)
-
-/** \brief Check if NAT static mapping match only out2in direction.
-    @param sm NAT static mapping
-    @return 1 if rule match only out2in direction
-*/
-#define is_out2in_only_static_mapping(sm) (sm->flags & NAT_STATIC_MAPPING_FLAG_OUT2IN_ONLY)
-
-/** \brief Check if NAT static mapping is identity NAT.
-    @param sm NAT static mapping
-    @return 1 if identity NAT
-*/
-#define is_identity_static_mapping(sm) (sm->flags & NAT_STATIC_MAPPING_FLAG_IDENTITY_NAT)
-
-/** \brief Check if NAT static mapping is load-balancing.
-    @param sm NAT static mapping
-    @return 1 if load-balancing
-*/
-#define is_lb_static_mapping(sm) (sm->flags & NAT_STATIC_MAPPING_FLAG_LB)
-
-/** \brief Check if exact pool address should be used.
-    @param s SNAT session
-    @return 1 if exact pool address or 0
-*/
-#define is_exact_address(s) (s->flags & NAT_STATIC_MAPPING_FLAG_EXACT_ADDRESS)
-
-/** \brief Check if client initiating TCP connection (received SYN from client)
-    @param t TCP header
-    @return 1 if client initiating TCP connection
-*/
-always_inline bool
-tcp_flags_is_init (u8 f)
-{
-  return (f & TCP_FLAG_SYN) && !(f & TCP_FLAG_ACK);
-}
-
-/* logging */
-#define nat_log_err(...) \
-  vlib_log(VLIB_LOG_LEVEL_ERR, snat_main.log_class, __VA_ARGS__)
-#define nat_log_warn(...) \
-  vlib_log(VLIB_LOG_LEVEL_WARNING, snat_main.log_class, __VA_ARGS__)
-#define nat_log_notice(...) \
-  vlib_log(VLIB_LOG_LEVEL_NOTICE, snat_main.log_class, __VA_ARGS__)
-#define nat_log_info(...) \
-  vlib_log(VLIB_LOG_LEVEL_INFO, snat_main.log_class, __VA_ARGS__)
-#define nat_log_debug(...)\
-  vlib_log(VLIB_LOG_LEVEL_DEBUG, snat_main.log_class, __VA_ARGS__)
-
-/* NAT API Logging Levels */
-#define foreach_nat_log_level \
-  _(0x00, LOG_NONE)           \
-  _(0x01, LOG_ERROR)          \
-  _(0x02, LOG_WARNING)        \
-  _(0x03, LOG_NOTICE)         \
-  _(0x04, LOG_INFO)           \
-  _(0x05, LOG_DEBUG)
-
-typedef enum nat_log_level_t_
-{
-#define _(n,f) SNAT_##f = n,
-  foreach_nat_log_level
-#undef _
-} nat_log_level_t;
-
-#define nat_elog(_level, _str)                           \
-do                                                       \
-  {                                                      \
-    snat_main_t *sm = &snat_main;                        \
-    if (PREDICT_FALSE (sm->log_level >= _level))         \
-      {                                                  \
-        ELOG_TYPE_DECLARE (e) =                          \
-          {                                              \
-            .format = "nat-msg " _str,                   \
-            .format_args = "",                           \
-          };                                             \
-        ELOG_DATA (&vlib_global_main.elog_main, e);      \
-      }                                                  \
-  } while (0);
-
-#define nat_elog_addr(_level, _str, _addr)               \
-do                                                       \
-  {                                                      \
-    if (PREDICT_FALSE (sm->log_level >= _level))         \
-      {                                                  \
-        ELOG_TYPE_DECLARE (e) =                          \
-          {                                              \
-            .format = "nat-msg " _str " %d.%d.%d.%d",    \
-            .format_args = "i1i1i1i1",                   \
-          };                                             \
-        CLIB_PACKED(struct                               \
-          {                                              \
-            u8 oct1;                                     \
-            u8 oct2;                                     \
-            u8 oct3;                                     \
-            u8 oct4;                                     \
-          }) *ed;                                        \
-        ed = ELOG_DATA (&vlib_global_main.elog_main, e); \
-        ed->oct4 = _addr >> 24;                          \
-        ed->oct3 = _addr >> 16;                          \
-        ed->oct2 = _addr >> 8;                           \
-        ed->oct1 = _addr;                                \
-    }                                                    \
-  } while (0);
-
-#define nat_elog_debug_handoff(_str, _tid, _fib, _src, _dst)                \
-do                                                                          \
-  {                                                                         \
-  if (PREDICT_FALSE (sm->log_level >= SNAT_LOG_DEBUG))                      \
-    {                                                                       \
-      ELOG_TYPE_DECLARE (e) =                                               \
-        {                                                                   \
-          .format = "nat-msg " _str " ip src: %d.%d.%d.%d dst: %d.%d.%d.%d" \
-                                    " tid from: %d to: %d fib: %d",         \
-        .format_args = "i1i1i1i1i1i1i1i1i4i4i4",                            \
-      };                                                                    \
-      CLIB_PACKED(struct                                                    \
-        {                                                                   \
-          u8 src_oct1;                                                      \
-          u8 src_oct2;                                                      \
-          u8 src_oct3;                                                      \
-          u8 src_oct4;                                                      \
-          u8 dst_oct1;                                                      \
-          u8 dst_oct2;                                                      \
-          u8 dst_oct3;                                                      \
-          u8 dst_oct4;                                                      \
-          u32 ftid;                                                         \
-          u32 ttid;                                                         \
-          u32 fib;                                                          \
-        }) *ed;                                                             \
-      ed = ELOG_DATA (&vlib_global_main.elog_main, e);                      \
-      ed->src_oct1 = _src >> 24;                                            \
-      ed->src_oct2 = _src >> 16;                                            \
-      ed->src_oct3 = _src >> 8;                                             \
-      ed->src_oct4 = _src;                                                  \
-      ed->dst_oct1 = _dst >> 24;                                            \
-      ed->dst_oct2 = _dst >> 16;                                            \
-      ed->dst_oct3 = _dst >> 8;                                             \
-      ed->dst_oct4 = _dst;                                                  \
-      ed->ftid = vlib_get_thread_index ();                                  \
-      ed->ttid = _tid;                                                      \
-      ed->fib = _fib;                                                       \
-    }                                                                       \
-  } while (0);
-
-#define nat_elog_debug_handoff_v2(_str, _prt, _fib, _src, _dst)              \
-do                                                                           \
-  {                                                                          \
-  if (PREDICT_FALSE (sm->log_level >= SNAT_LOG_DEBUG))                       \
-    {                                                                        \
-      ELOG_TYPE_DECLARE (e) =                                                \
-        {                                                                    \
-          .format = "nat-msg " _str " ip_src:%d.%d.%d.%d ip_dst:%d.%d.%d.%d" \
-                                    " tid:%d prt:%d fib:%d",                 \
-        .format_args = "i1i1i1i1i1i1i1i1i4i4i4",                             \
-      };                                                                     \
-      CLIB_PACKED(struct                                                     \
-        {                                                                    \
-          u8 src_oct1;                                                       \
-          u8 src_oct2;                                                       \
-          u8 src_oct3;                                                       \
-          u8 src_oct4;                                                       \
-          u8 dst_oct1;                                                       \
-          u8 dst_oct2;                                                       \
-          u8 dst_oct3;                                                       \
-          u8 dst_oct4;                                                       \
-          u32 tid;                                                           \
-          u32 prt;                                                           \
-          u32 fib;                                                           \
-        }) *ed;                                                              \
-      ed = ELOG_DATA (&vlib_global_main.elog_main, e);                       \
-      ed->src_oct1 = _src >> 24;                                             \
-      ed->src_oct2 = _src >> 16;                                             \
-      ed->src_oct3 = _src >> 8;                                              \
-      ed->src_oct4 = _src;                                                   \
-      ed->dst_oct1 = _dst >> 24;                                             \
-      ed->dst_oct2 = _dst >> 16;                                             \
-      ed->dst_oct3 = _dst >> 8;                                              \
-      ed->dst_oct4 = _dst;                                                   \
-      ed->tid = vlib_get_thread_index ();                                    \
-      ed->prt = _prt;                                                        \
-      ed->fib = _fib;                                                        \
-    }                                                                        \
-  } while (0);
-
-#define nat_elog_X1(_level, _fmt, _arg, _val1)            \
-do                                                        \
-  {                                                       \
-    snat_main_t *sm = &snat_main;                         \
-    if (PREDICT_FALSE (sm->log_level >= _level))          \
-      {                                                   \
-        ELOG_TYPE_DECLARE (e) =                           \
-          {                                               \
-            .format = "nat-msg " _fmt,                    \
-            .format_args = _arg,                          \
-          };                                              \
-        CLIB_PACKED(struct                                \
-          {                                               \
-            typeof (_val1) val1;                          \
-          }) *ed;                                         \
-        ed = ELOG_DATA (&vlib_global_main.elog_main, e);  \
-        ed->val1 = _val1;                                 \
-      }                                                   \
-  } while (0);
-
-#define nat_elog_notice(nat_elog_str) \
-  nat_elog(SNAT_LOG_INFO, "[notice] " nat_elog_str)
-#define nat_elog_warn(nat_elog_str) \
-  nat_elog(SNAT_LOG_WARNING, "[warning] " nat_elog_str)
-#define nat_elog_err(nat_elog_str) \
-  nat_elog(SNAT_LOG_ERROR, "[error] " nat_elog_str)
-#define nat_elog_debug(nat_elog_str) \
-  nat_elog(SNAT_LOG_DEBUG, "[debug] " nat_elog_str)
-#define nat_elog_info(nat_elog_str) \
-  nat_elog(SNAT_LOG_INFO, "[info] " nat_elog_str)
-
-#define nat_elog_notice_X1(nat_elog_fmt_str, nat_elog_fmt_arg, nat_elog_val1) \
-  nat_elog_X1(SNAT_LOG_NOTICE, "[notice] " nat_elog_fmt_str, nat_elog_fmt_arg, nat_elog_val1)
-#define nat_elog_warn_X1(nat_elog_fmt_str, nat_elog_fmt_arg, nat_elog_val1) \
-  nat_elog_X1(SNAT_LOG_WARNING, "[warning] " nat_elog_fmt_str, nat_elog_fmt_arg, nat_elog_val1)
-#define nat_elog_err_X1(nat_elog_fmt_str, nat_elog_fmt_arg, nat_elog_val1) \
-  nat_elog_X1(SNAT_LOG_ERROR, "[error] " nat_elog_fmt_str, nat_elog_fmt_arg, nat_elog_val1)
-#define nat_elog_debug_X1(nat_elog_fmt_str, nat_elog_fmt_arg, nat_elog_val1) \
-  nat_elog_X1(SNAT_LOG_DEBUG, "[debug] " nat_elog_fmt_str, nat_elog_fmt_arg, nat_elog_val1)
-#define nat_elog_info_X1(nat_elog_fmt_str, nat_elog_fmt_arg, nat_elog_val1) \
-  nat_elog_X1(SNAT_LOG_INFO, "[info] " nat_elog_fmt_str, nat_elog_fmt_arg, nat_elog_val1)
-
-/* ICMP session match functions */
-u32 icmp_match_in2out_fast (snat_main_t *sm, vlib_node_runtime_t *node,
-			    u32 thread_index, vlib_buffer_t *b0,
-			    ip4_header_t *ip0, ip4_address_t *addr, u16 *port,
-			    u32 *fib_index, nat_protocol_t *proto,
-			    snat_session_t **s0, u8 *dont_translate);
-u32 icmp_match_in2out_slow (snat_main_t *sm, vlib_node_runtime_t *node,
-			    u32 thread_index, vlib_buffer_t *b0,
-			    ip4_header_t *ip0, ip4_address_t *addr, u16 *port,
-			    u32 *fib_index, nat_protocol_t *proto,
-			    snat_session_t **s0, u8 *dont_translate);
-u32 icmp_match_out2in_fast (snat_main_t *sm, vlib_node_runtime_t *node,
-			    u32 thread_index, vlib_buffer_t *b0,
-			    ip4_header_t *ip0, ip4_address_t *addr, u16 *port,
-			    u32 *fib_index, nat_protocol_t *proto,
-			    snat_session_t **s0, u8 *dont_translate);
-u32 icmp_match_out2in_slow (snat_main_t *sm, vlib_node_runtime_t *node,
-			    u32 thread_index, vlib_buffer_t *b0,
-			    ip4_header_t *ip0, ip4_address_t *addr, u16 *port,
-			    u32 *fib_index, nat_protocol_t *proto,
-			    snat_session_t **s0, u8 *dont_translate);
-
-/* hairpinning functions */
-u32 snat_icmp_hairpinning (snat_main_t *sm, vlib_buffer_t *b0,
-			   u32 thread_index, ip4_header_t *ip0,
-			   icmp46_header_t *icmp0, u32 *required_thread_index);
-
-void nat_hairpinning_sm_unknown_proto (snat_main_t * sm, vlib_buffer_t * b,
-				       ip4_header_t * ip);
-
-int snat_hairpinning (vlib_main_t *vm, vlib_node_runtime_t *node,
-		      snat_main_t *sm, u32 thread_index, vlib_buffer_t *b0,
-		      ip4_header_t *ip0, udp_header_t *udp0,
-		      tcp_header_t *tcp0, u32 proto0, int do_trace,
-		      u32 *required_thread_index);
-
-/* Call back functions for clib_bihash_add_or_overwrite_stale */
-int nat44_i2o_is_idle_session_cb (clib_bihash_kv_8_8_t * kv, void *arg);
-int nat44_o2i_is_idle_session_cb (clib_bihash_kv_8_8_t * kv, void *arg);
-
-
-/**
- * @brief Enable NAT44 plugin
- *
- * @param c         nat44_config_t
- *
- * @return 0 on success, non-zero value otherwise
- */
-int nat44_plugin_enable (nat44_config_t c);
-
-/**
- * @brief Disable NAT44 plugin
- *
- * @return 0 on success, non-zero value otherwise
- */
-int nat44_plugin_disable ();
-
-/**
- * @brief Add external address to NAT44 pool
- *
- * @param sm        snat global configuration data
- * @param addr      IPv4 address
- * @param vrf_id    VRF id of tenant, ~0 means independent of VRF
- * @param twice_nat 1 if twice NAT address
- *
- * @return 0 on success, non-zero value otherwise
- */
-int snat_add_address (snat_main_t * sm, ip4_address_t * addr, u32 vrf_id,
-		      u8 twice_nat);
-
-/**
- * @brief Delete external address from NAT44 pool
- *
- * @param sm        snat global configuration data
- * @param addr      IPv4 address
- * @param delete_sm 1 if delete static mapping using address
- * @param twice_nat 1 if twice NAT address
- *
- * @return 0 on success, non-zero value otherwise
- */
-int snat_del_address (snat_main_t * sm, ip4_address_t addr, u8 delete_sm,
-		      u8 twice_nat);
-
-/**
- * @brief Add/delete external address to FIB DPO (out2in DPO mode)
- *
- * @param addr   IPv4 address
- * @param is_add 1 = add, 0 = delete
- *
- * @return 0 on success, non-zero value otherwise
- */
-void nat44_add_del_address_dpo (ip4_address_t addr, u8 is_add);
-
-/**
- * @brief Add/delete NAT44 static mapping
- *
- * @param l_addr       local IPv4 address
- * @param e_addr       external IPv4 address
- * @param l_port       local port number
- * @param e_port       external port number
- * @param vrf_id       local VRF ID
- * @param addr_only    1 = 1:1NAT, 0 = 1:1NAPT
- * @param sw_if_index  use interface address as external IPv4 address
- * @param proto        L4 protocol
- * @param is_add       1 = add, 0 = delete
- * @param twice_nat    twice-nat mode
- * @param out2in_only  if 1 rule match only out2in direction
- * @param tag          opaque string tag
- * @param identity_nat identity NAT
- * @param pool_addr    pool IPv4 address
- * @param exact        1 = exact pool address
- *
- * @return 0 on success, non-zero value otherwise
- */
-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,
-			     nat_protocol_t proto, int is_add,
-			     twice_nat_type_t twice_nat, u8 out2in_only,
-			     u8 * tag, u8 identity_nat,
-			     ip4_address_t pool_addr, int exact);
-
-/**
- * @brief Add/delete static mapping with load-balancing (multiple backends)
- *
- * @param e_addr      external IPv4 address
- * @param e_port      external port number
- * @param proto       L4 protocol
- * @param locals      list of local backends
- * @param is_add      1 = add, 0 = delete
- * @param twice_nat   twice-nat mode
- * @param out2in_only if 1 rule match only out2in direction
- * @param tag         opaque string tag
- * @param affinity    0 = disabled, otherwise client IP affinity sticky time
- *
- * @return 0 on success, non-zero value otherwise
- */
-int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
-				     nat_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);
-
-int nat44_lb_static_mapping_add_del_local (ip4_address_t e_addr, u16 e_port,
-					   ip4_address_t l_addr, u16 l_port,
-					   nat_protocol_t proto, u32 vrf_id,
-					   u8 probability, u8 is_add);
-
-clib_error_t *nat44_api_hookup (vlib_main_t * vm);
-
-/**
- * @brief Set NAT plugin workers
- *
- * @param bitmap NAT workers bitmap
- *
- * @return 0 on success, non-zero value otherwise
- */
-int snat_set_workers (uword * bitmap);
-
-/**
- * @brief Set NAT plugin number of frame queue elements
- *
- * @param frame_queue_nelts number of worker handoff frame queue elements
- *
- * @return 0 on success, non-zero value otherwise
- */
-int snat_set_frame_queue_nelts (u32 frame_queue_nelts);
-
-/**
- * @brief Enable/disable NAT44 feature on the interface
- *
- * @param sw_if_index software index of the interface
- * @param is_inside   1 = inside, 0 = outside
- * @param is_del      1 = delete, 0 = add
- *
- * @return 0 on success, non-zero value otherwise
- */
-int snat_interface_add_del (u32 sw_if_index, u8 is_inside, int is_del);
-
-/**
- * @brief Enable/disable NAT44 output feature on the interface (postrouting NAT)
- *
- * @param sw_if_index software index of the interface
- * @param is_inside   1 = inside, 0 = outside
- * @param is_del      1 = delete, 0 = add
- *
- * @return 0 on success, non-zero value otherwise
- */
-int snat_interface_add_del_output_feature (u32 sw_if_index, u8 is_inside,
-					   int is_del);
-
-/**
- * @brief Add/delete NAT44 pool address from specific interface
- *
- * @param sw_if_index software index of the interface
- * @param is_del      1 = delete, 0 = add
- * @param twice_nat   1 = twice NAT address for external hosts
- *
- * @return 0 on success, non-zero value otherwise
- */
-int snat_add_interface_address (snat_main_t * sm, u32 sw_if_index, int is_del,
-				u8 twice_nat);
-
-/**
- * @brief Delete NAT44 endpoint-dependent session
- *
- * @param sm     snat global configuration data
- * @param addr   IPv4 address
- * @param port   L4 port number
- * @param proto  L4 protocol
- * @param vrf_id VRF ID
- * @param is_in  1 = inside network address and port pair, 0 = outside
- *
- * @return 0 on success, non-zero value otherwise
- */
-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);
-
-/**
- * @brief Free NAT44 session data (lookup keys, external address port)
- *
- * @param sm           snat global configuration data
- * @param s            NAT session
- * @param thread_index thread index
- * @param is_ha        is HA event
- */
-void nat_free_session_data (snat_main_t * sm, snat_session_t * s,
-			    u32 thread_index, u8 is_ha);
-
-/**
- * @brief Set NAT44 session limit (session limit, vrf id)
- *
- * @param session_limit Session limit
- * @param vrf_id        VRF id
- * @return 0 on success, non-zero value otherwise
- */
-int nat44_set_session_limit (u32 session_limit, u32 vrf_id);
-
-/**
- * @brief Update NAT44 session limit flushing all data (session limit, vrf id)
- *
- * @param session_limit Session limit
- * @param vrf_id        VRF id
- * @return 0 on success, non-zero value otherwise
- */
-int nat44_update_session_limit (u32 session_limit, u32 vrf_id);
-
-/**
- * @brief Free all NAT44 sessions
- */
-void nat44_sessions_clear ();
-
-/**
- * @brief Find or create NAT user
- *
- * @param sm           snat global configuration data
- * @param addr         IPv4 address
- * @param fib_index    FIB table index
- * @param thread_index thread index
- *
- * @return NAT user data structure on success otherwise zero value
- */
-snat_user_t *nat_user_get_or_create (snat_main_t * sm,
-				     ip4_address_t * addr, u32 fib_index,
-				     u32 thread_index);
-
-/**
- * @brief Allocate new NAT session or recycle last used
- *
- * @param sm           snat global configuration data
- * @param u            NAT user
- * @param thread_index thread index
- * @param now          time now
- *
- * @return session data structure on success otherwise zero value
- */
-snat_session_t *nat_session_alloc_or_recycle (snat_main_t * sm,
-					      snat_user_t * u,
-					      u32 thread_index, f64 now);
-
-/**
- * @brief Free outside address and port pair
- *
- * @param addresses    vector of outside addresses
- * @param thread_index thread index
- * @param key          address, port and protocol
- */
-void
-snat_free_outside_address_and_port (snat_address_t * addresses,
-				    u32 thread_index,
-				    ip4_address_t * addr,
-				    u16 port, nat_protocol_t protocol);
-
-void expire_per_vrf_sessions (u32 fib_index);
-
-/**
- * @brief Match NAT44 static mapping.
- *
- * @param key             address and port to match
- * @param addr            external/local address of the matched mapping
- * @param port            port of the matched mapping
- * @param fib_index       fib index of the matched mapping
- * @param by_external     if 0 match by local address otherwise match by external
- *                        address
- * @param is_addr_only    1 if matched mapping is address only
- * @param twice_nat       matched mapping is twice NAT type
- * @param lb              1 if matched mapping is load-balanced
- * @param ext_host_addr   external host address
- * @param is_identity_nat 1 if indentity mapping
- * @param out             if !=0 set to pointer of the mapping structure
- *
- * @returns 0 if match found otherwise 1.
- */
-int snat_static_mapping_match (snat_main_t * sm,
-			       ip4_address_t match_addr,
-			       u16 match_port,
-			       u32 match_fib_index,
-			       nat_protocol_t match_protocol,
-			       ip4_address_t * mapping_addr,
-			       u16 * mapping_port,
-			       u32 * mapping_fib_index,
-			       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,
-			       snat_static_mapping_t ** out);
-
-/**
- * @brief Add/del NAT address to FIB.
- *
- * Add the external NAT address to the FIB as receive entries. This ensures
- * that VPP will reply to ARP for this address and we don't need to enable
- * proxy ARP on the outside interface.
- *
- * @param addr        IPv4 address
- * @param plen        address prefix length
- * @param sw_if_index software index of the outside interface
- * @param is_add      0 = delete, 1 = add.
- */
-void snat_add_del_addr_to_fib (ip4_address_t * addr,
-			       u8 p_len, u32 sw_if_index, int is_add);
-
-#if 0
-void
-nat_ha_sadd_ed_cb (ip4_address_t * in_addr, u16 in_port,
-		   ip4_address_t * out_addr, u16 out_port,
-		   ip4_address_t * eh_addr, u16 eh_port,
-		   ip4_address_t * ehn_addr, u16 ehn_port, u8 proto,
-		   u32 fib_index, u16 flags, u32 thread_index);
-
-void
-nat_ha_sdel_ed_cb (ip4_address_t * out_addr, u16 out_port,
-		   ip4_address_t * eh_addr, u16 eh_port, u8 proto,
-		   u32 fib_index, u32 ti);
-
-void
-nat_ha_sref_ed_cb (ip4_address_t * out_addr, u16 out_port,
-		   ip4_address_t * eh_addr, u16 eh_port, u8 proto,
-		   u32 fib_index, u32 total_pkts, u64 total_bytes,
-		   u32 thread_index);
-#endif
-
-int nat_set_outside_address_and_port (snat_address_t *addresses,
-				      u32 thread_index, ip4_address_t addr,
-				      u16 port, nat_protocol_t protocol);
-
-/*
- * Why is this here? Because we don't need to touch this layer to
- * simply reply to an icmp. We need to change id to a unique
- * value to NAT an echo request/reply.
- */
-
-typedef struct
-{
-  u16 identifier;
-  u16 sequence;
-} icmp_echo_header_t;
-
-typedef struct
-{
-  u16 src_port, dst_port;
-} tcp_udp_header_t;
-
-u8 *format_user_kvp (u8 * s, va_list * args);
-
-u32 get_thread_idx_by_port (u16 e_port);
-
-u8 *format_static_mapping_kvp (u8 *s, va_list *args);
-
-u8 *format_session_kvp (u8 *s, va_list *args);
-
-u8 *format_user_kvp (u8 *s, va_list *args);
-
-u32 nat_calc_bihash_buckets (u32 n_elts);
-
-void nat44_addresses_free (snat_address_t **addresses);
-
-typedef enum
-{
-  NAT_ED_TRNSL_ERR_SUCCESS = 0,
-  NAT_ED_TRNSL_ERR_TRANSLATION_FAILED = 1,
-  NAT_ED_TRNSL_ERR_FLOW_MISMATCH = 2,
-} nat_translation_error_e;
-
-nat_translation_error_e
-nat_6t_flow_buf_translate (snat_main_t *sm, vlib_buffer_t *b, ip4_header_t *ip,
-			   nat_6t_flow_t *f, nat_protocol_t proto,
-			   int is_output_feature);
-
-void nat_6t_l3_l4_csum_calc (nat_6t_flow_t *f);
-
-format_function_t format_nat_ed_translation_error;
-format_function_t format_nat_6t_flow;
-format_function_t format_ed_session_kvp;
-
-#endif /* __included_nat_h__ */
-/*
- * fd.io coding-style-patch-verification: ON
- *
- * Local Variables:
- * eval: (c-set-style "gnu")
- * End:
- */