src/plugins/nat/nat.h

   1
   2 /*
   3  * nat.h - NAT plugin definitions
   4  *
   5  * Copyright (c) 2016 Cisco and/or its affiliates.
   6  * Licensed under the Apache License, Version 2.0 (the "License");
   7  * you may not use this file except in compliance with the License.
   8  * You may obtain a copy of the License at:
   9  *
  10  *     http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  * Unless required by applicable law or agreed to in writing, software
  13  * distributed under the License is distributed on an "AS IS" BASIS,
  14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  * See the License for the specific language governing permissions and
  16  * limitations under the License.
  17  */
  18 #ifndef __included_nat_h__
  19 #define __included_nat_h__
  20
  21 #include <vnet/vnet.h>
  22 #include <vnet/ip/ip.h>
  23 #include <vnet/ethernet/ethernet.h>
  24 #include <vnet/ip/icmp46_packet.h>
  25 #include <vnet/api_errno.h>
  26 #include <vppinfra/bihash_8_8.h>
  27 #include <vppinfra/bihash_16_8.h>
  28 #include <vppinfra/dlist.h>
  29 #include <vppinfra/error.h>
  30 #include <vlibapi/api.h>
  31 #include <vlib/log.h>
  32
  33
  34 #define SNAT_UDP_TIMEOUT 300
  35 #define SNAT_UDP_TIMEOUT_MIN 120
  36 #define SNAT_TCP_TRANSITORY_TIMEOUT 240
  37 #define SNAT_TCP_ESTABLISHED_TIMEOUT 7440
  38 #define SNAT_TCP_INCOMING_SYN 6
  39 #define SNAT_ICMP_TIMEOUT 60
  40
  41 #define NAT_FQ_NELTS 64
  42
  43 #define SNAT_FLAG_HAIRPINNING (1 << 0)
  44
  45 /* Key */
  46 typedef struct {
  47   union
  48   {
  49     struct
  50     {
  51       ip4_address_t addr;
  52       u16 port;
  53       u16 protocol:3,
  54         fib_index:13;
  55     };
  56     u64 as_u64;
  57   };
  58 } snat_session_key_t;
  59
  60 typedef struct {
  61   union
  62   {
  63     struct
  64     {
  65       ip4_address_t l_addr;
  66       ip4_address_t r_addr;
  67       u32 proto:8,
  68           fib_index:24;
  69       u16 l_port;
  70       u16 r_port;
  71     };
  72     u64 as_u64[2];
  73   };
  74 } nat_ed_ses_key_t;
  75
  76 typedef struct {
  77   union
  78   {
  79     struct
  80     {
  81       ip4_address_t ext_host_addr;
  82       u16 ext_host_port;
  83       u16 out_port;
  84     };
  85     u64 as_u64;
  86   };
  87 } snat_det_out_key_t;
  88
  89 typedef struct {
  90   union
  91   {
  92     struct
  93     {
  94       ip4_address_t addr;
  95       u32 fib_index;
  96     };
  97     u64 as_u64;
  98   };
  99 } snat_user_key_t;
 100
 101
 102 #define foreach_snat_protocol \
 103   _(UDP, 0, udp, "udp")       \
 104   _(TCP, 1, tcp, "tcp")       \
 105   _(ICMP, 2, icmp, "icmp")
 106
 107 typedef enum {
 108 #define _(N, i, n, s) SNAT_PROTOCOL_##N = i,
 109   foreach_snat_protocol
 110 #undef _
 111 } snat_protocol_t;
 112
 113
 114 #define foreach_snat_session_state          \
 115   _(0, UNKNOWN, "unknown")                 \
 116   _(1, UDP_ACTIVE, "udp-active")           \
 117   _(2, TCP_SYN_SENT, "tcp-syn-sent")       \
 118   _(3, TCP_ESTABLISHED, "tcp-established") \
 119   _(4, TCP_FIN_WAIT, "tcp-fin-wait")       \
 120   _(5, TCP_CLOSE_WAIT, "tcp-close-wait")   \
 121   _(6, TCP_CLOSING, "tcp-closing")         \
 122   _(7, TCP_LAST_ACK, "tcp-last-ack")       \
 123   _(8, TCP_CLOSED, "tcp-closed")           \
 124   _(9, ICMP_ACTIVE, "icmp-active")
 125
 126 typedef enum {
 127 #define _(v, N, s) SNAT_SESSION_##N = v,
 128   foreach_snat_session_state
 129 #undef _
 130 } snat_session_state_t;
 131
 132 #define NAT44_SES_I2O_FIN 1
 133 #define NAT44_SES_O2I_FIN 2
 134 #define NAT44_SES_I2O_FIN_ACK 4
 135 #define NAT44_SES_O2I_FIN_ACK 8
 136
 137 #define nat44_is_ses_closed(s) s->state == 0xf
 138
 139 #define SNAT_SESSION_FLAG_STATIC_MAPPING       1
 140 #define SNAT_SESSION_FLAG_UNKNOWN_PROTO        2
 141 #define SNAT_SESSION_FLAG_LOAD_BALANCING       4
 142 #define SNAT_SESSION_FLAG_TWICE_NAT            8
 143 #define SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT   16
 144 #define SNAT_SESSION_FLAG_FWD_BYPASS           32
 145
 146 #define NAT_INTERFACE_FLAG_IS_INSIDE 1
 147 #define NAT_INTERFACE_FLAG_IS_OUTSIDE 2
 148
 149 typedef CLIB_PACKED(struct {
 150   snat_session_key_t out2in;    /* 0-15 */
 151
 152   snat_session_key_t in2out;    /* 16-31 */
 153
 154   u32 flags;                    /* 32-35 */
 155
 156   /* per-user translations */
 157   u32 per_user_index;           /* 36-39 */
 158
 159   u32 per_user_list_head_index; /* 40-43 */
 160
 161   /* Last heard timer */
 162   f64 last_heard;               /* 44-51 */
 163
 164   u64 total_bytes;              /* 52-59 */
 165
 166   u32 total_pkts;               /* 60-63 */
 167
 168   /* Outside address */
 169   u32 outside_address_index;    /* 64-67 */
 170
 171   /* External host address and port */
 172   ip4_address_t ext_host_addr;  /* 68-71 */
 173   u16 ext_host_port;            /* 72-73 */
 174
 175   /* External hos address and port after translation */
 176   ip4_address_t ext_host_nat_addr; /* 74-77 */
 177   u16 ext_host_nat_port;           /* 78-79 */
 178
 179   /* TCP session state */
 180   u8 state;
 181   u32 i2o_fin_seq;
 182   u32 o2i_fin_seq;
 183 }) snat_session_t;
 184
 185
 186 typedef struct {
 187   ip4_address_t addr;
 188   u32 fib_index;
 189   u32 sessions_per_user_list_head_index;
 190   u32 nsessions;
 191   u32 nstaticsessions;
 192 } snat_user_t;
 193
 194 typedef struct {
 195   ip4_address_t addr;
 196   u32 fib_index;
 197 #define _(N, i, n, s) \
 198   u16 busy_##n##_ports; \
 199   u16 * busy_##n##_ports_per_thread; \
 200   uword * busy_##n##_port_bitmap;
 201   foreach_snat_protocol
 202 #undef _
 203 } snat_address_t;
 204
 205 typedef struct {
 206   u32 fib_index;
 207   u32 refcount;
 208 } nat_outside_fib_t;
 209
 210 typedef struct {
 211   u16 in_port;
 212   snat_det_out_key_t out;
 213   u8 state;
 214   u32 expire;
 215 } snat_det_session_t;
 216
 217 typedef struct {
 218   ip4_address_t in_addr;
 219   u8 in_plen;
 220   ip4_address_t out_addr;
 221   u8 out_plen;
 222   u32 sharing_ratio;
 223   u16 ports_per_host;
 224   u32 ses_num;
 225   /* vector of sessions */
 226   snat_det_session_t * sessions;
 227 } snat_det_map_t;
 228
 229 typedef struct {
 230   ip4_address_t addr;
 231   u16 port;
 232   u8 probability;
 233   u8 prefix;
 234 } nat44_lb_addr_port_t;
 235
 236 typedef enum {
 237   TWICE_NAT_DISABLED,
 238   TWICE_NAT,
 239   TWICE_NAT_SELF,
 240 } twice_nat_type_t;
 241
 242 typedef struct {
 243   ip4_address_t local_addr;
 244   ip4_address_t external_addr;
 245   u16 local_port;
 246   u16 external_port;
 247   u8 addr_only;
 248   twice_nat_type_t twice_nat;
 249   u8 out2in_only;
 250   u32 vrf_id;
 251   u32 fib_index;
 252   snat_protocol_t proto;
 253   u32 *workers;
 254   u8 *tag;
 255   nat44_lb_addr_port_t *locals;
 256 } snat_static_mapping_t;
 257
 258 typedef struct {
 259   u32 sw_if_index;
 260   u8 flags;
 261 } snat_interface_t;
 262
 263 typedef struct {
 264   ip4_address_t l_addr;
 265   u16 l_port;
 266   u16 e_port;
 267   u32 sw_if_index;
 268   u32 vrf_id;
 269   snat_protocol_t proto;
 270   int addr_only;
 271   int twice_nat;
 272   int is_add;
 273   u8 *tag;
 274 } snat_static_map_resolve_t;
 275
 276 typedef struct {
 277   /* Main lookup tables */
 278   clib_bihash_8_8_t out2in;
 279   clib_bihash_8_8_t in2out;
 280
 281   /* Endpoint dependent sessions lookup tables */
 282   clib_bihash_16_8_t out2in_ed;
 283   clib_bihash_16_8_t in2out_ed;
 284
 285   /* Find-a-user => src address lookup */
 286   clib_bihash_8_8_t user_hash;
 287
 288   /* User pool */
 289   snat_user_t * users;
 290
 291   /* Session pool */
 292   snat_session_t * sessions;
 293
 294   /* Pool of doubly-linked list elements */
 295   dlist_elt_t * list_pool;
 296
 297   u32 snat_thread_index;
 298 } snat_main_per_thread_data_t;
 299
 300 struct snat_main_s;
 301
 302 typedef u32 snat_icmp_match_function_t (struct snat_main_s *sm,
 303                                         vlib_node_runtime_t *node,
 304                                         u32 thread_index,
 305                                         vlib_buffer_t *b0,
 306                                         ip4_header_t *ip0,
 307                                         u8 *p_proto,
 308                                         snat_session_key_t *p_value,
 309                                         u8 *p_dont_translate,
 310                                         void *d,
 311                                         void *e);
 312
 313 typedef u32 (snat_get_worker_function_t) (ip4_header_t * ip, u32 rx_fib_index);
 314
 315 typedef int nat_alloc_out_addr_and_port_function_t (snat_address_t * addresses,
 316                                                     u32 fib_index,
 317                                                     u32 thread_index,
 318                                                     snat_session_key_t * k,
 319                                                     u32 * address_indexp,
 320                                                     u16 port_per_thread,
 321                                                     u32 snat_thread_index);
 322
 323 typedef struct snat_main_s {
 324   snat_icmp_match_function_t * icmp_match_in2out_cb;
 325   snat_icmp_match_function_t * icmp_match_out2in_cb;
 326
 327   u32 num_workers;
 328   u32 first_worker_index;
 329   u32 * workers;
 330   snat_get_worker_function_t * worker_in2out_cb;
 331   snat_get_worker_function_t * worker_out2in_cb;
 332   u16 port_per_thread;
 333   u32 num_snat_thread;
 334
 335   /* Per thread data */
 336   snat_main_per_thread_data_t * per_thread_data;
 337
 338   /* Find a static mapping by local */
 339   clib_bihash_8_8_t static_mapping_by_local;
 340
 341   /* Find a static mapping by external */
 342   clib_bihash_8_8_t static_mapping_by_external;
 343
 344   /* Static mapping pool */
 345   snat_static_mapping_t * static_mappings;
 346
 347   /* Interface pool */
 348   snat_interface_t * interfaces;
 349   snat_interface_t * output_feature_interfaces;
 350
 351   /* Vector of outside addresses */
 352   snat_address_t * addresses;
 353   nat_alloc_out_addr_and_port_function_t *alloc_addr_and_port;
 354   u8 psid_offset;
 355   u8 psid_length;
 356   u16 psid;
 357
 358   /* vector of outside fibs */
 359   nat_outside_fib_t * outside_fibs;
 360
 361   /* Vector of twice NAT addresses for extenal hosts */
 362   snat_address_t * twice_nat_addresses;
 363
 364   /* sw_if_indices whose intfc addresses should be auto-added */
 365   u32 * auto_add_sw_if_indices;
 366   u32 * auto_add_sw_if_indices_twice_nat;
 367
 368   /* vector of interface address static mappings to resolve. */
 369   snat_static_map_resolve_t *to_resolve;
 370
 371   /* Randomize port allocation order */
 372   u32 random_seed;
 373
 374   /* Worker handoff index */
 375   u32 fq_in2out_index;
 376   u32 fq_in2out_output_index;
 377   u32 fq_out2in_index;
 378
 379   /* in2out and out2in node index */
 380   u32 in2out_node_index;
 381   u32 in2out_output_node_index;
 382   u32 out2in_node_index;
 383   u32 error_node_index;
 384
 385   /* Deterministic NAT */
 386   snat_det_map_t * det_maps;
 387
 388   /* If forwarding is enabled */
 389   u8 forwarding_enabled;
 390
 391   /* Config parameters */
 392   u8 static_mapping_only;
 393   u8 static_mapping_connection_tracking;
 394   u8 deterministic;
 395   u8 out2in_dpo;
 396   u8 endpoint_dependent;
 397   u32 translation_buckets;
 398   u32 translation_memory_size;
 399   u32 max_translations;
 400   u32 user_buckets;
 401   u32 user_memory_size;
 402   u32 max_translations_per_user;
 403   u32 outside_vrf_id;
 404   u32 outside_fib_index;
 405   u32 inside_vrf_id;
 406   u32 inside_fib_index;
 407
 408   /* values of various timeouts */
 409   u32 udp_timeout;
 410   u32 tcp_established_timeout;
 411   u32 tcp_transitory_timeout;
 412   u32 icmp_timeout;
 413
 414   /* API message ID base */
 415   u16 msg_id_base;
 416
 417   /* log class */
 418   vlib_log_class_t log_class;
 419
 420   /* convenience */
 421   vlib_main_t * vlib_main;
 422   vnet_main_t * vnet_main;
 423   ip4_main_t * ip4_main;
 424   ip_lookup_main_t * ip4_lookup_main;
 425   api_main_t * api_main;
 426 } snat_main_t;
 427
 428 extern snat_main_t snat_main;
 429 extern vlib_node_registration_t snat_in2out_node;
 430 extern vlib_node_registration_t snat_in2out_output_node;
 431 extern vlib_node_registration_t snat_out2in_node;
 432 extern vlib_node_registration_t snat_in2out_fast_node;
 433 extern vlib_node_registration_t snat_out2in_fast_node;
 434 extern vlib_node_registration_t snat_in2out_worker_handoff_node;
 435 extern vlib_node_registration_t snat_in2out_output_worker_handoff_node;
 436 extern vlib_node_registration_t snat_out2in_worker_handoff_node;
 437 extern vlib_node_registration_t snat_det_in2out_node;
 438 extern vlib_node_registration_t snat_det_out2in_node;
 439 extern vlib_node_registration_t snat_hairpin_dst_node;
 440 extern vlib_node_registration_t snat_hairpin_src_node;
 441 extern vlib_node_registration_t nat44_ed_in2out_node;
 442 extern vlib_node_registration_t nat44_ed_in2out_output_node;
 443 extern vlib_node_registration_t nat44_ed_out2in_node;
 444 extern vlib_node_registration_t nat44_ed_hairpin_dst_node;
 445 extern vlib_node_registration_t nat44_ed_hairpin_src_node;
 446 extern vlib_node_registration_t nat44_ed_in2out_worker_handoff_node;
 447 extern vlib_node_registration_t nat44_ed_in2out_output_worker_handoff_node;
 448 extern vlib_node_registration_t nat44_ed_out2in_worker_handoff_node;
 449
 450 void snat_free_outside_address_and_port (snat_address_t * addresses,
 451                                          u32 thread_index,
 452                                          snat_session_key_t * k,
 453                                          u32 address_index);
 454
 455 int snat_alloc_outside_address_and_port (snat_address_t * addresses,
 456                                          u32 fib_index,
 457                                          u32 thread_index,
 458                                          snat_session_key_t * k,
 459                                          u32 * address_indexp,
 460                                          u16 port_per_thread,
 461                                          u32 snat_thread_index);
 462
 463 int snat_static_mapping_match (snat_main_t * sm,
 464                                snat_session_key_t match,
 465                                snat_session_key_t * mapping,
 466                                u8 by_external,
 467                                u8 *is_addr_only,
 468                                twice_nat_type_t *twice_nat,
 469                                u8 *lb);
 470
 471 void snat_add_del_addr_to_fib (ip4_address_t * addr,
 472                                u8 p_len,
 473                                u32 sw_if_index,
 474                                int is_add);
 475
 476 format_function_t format_snat_user;
 477 format_function_t format_snat_static_mapping;
 478 format_function_t format_snat_static_map_to_resolve;
 479 format_function_t format_snat_session;
 480 format_function_t format_det_map_ses;
 481
 482 typedef struct {
 483   u32 cached_sw_if_index;
 484   u32 cached_ip4_address;
 485 } snat_runtime_t;
 486
 487 /** \brief Check if SNAT session is created from static mapping.
 488     @param s SNAT session
 489     @return 1 if SNAT session is created from static mapping otherwise 0
 490 */
 491 #define snat_is_session_static(s) (s->flags & SNAT_SESSION_FLAG_STATIC_MAPPING)
 492
 493 /** \brief Check if SNAT session for unknown protocol.
 494     @param s SNAT session
 495     @return 1 if SNAT session for unknown protocol otherwise 0
 496 */
 497 #define snat_is_unk_proto_session(s) (s->flags & SNAT_SESSION_FLAG_UNKNOWN_PROTO)
 498
 499 /** \brief Check if NAT session is twice NAT.
 500     @param s NAT session
 501     @return 1 if NAT session is twice NAT
 502 */
 503 #define is_twice_nat_session(s) (s->flags & SNAT_SESSION_FLAG_TWICE_NAT)
 504
 505 /** \brief Check if NAT session is load-balancing.
 506     @param s NAT session
 507     @return 1 if NAT session is load-balancing
 508 */
 509 #define is_lb_session(s) (s->flags & SNAT_SESSION_FLAG_LOAD_BALANCING)
 510
 511 /** \brief Check if NAT session is forwarding bypass.
 512     @param s NAT session
 513     @return 1 if NAT session is load-balancing
 514 */
 515 #define is_fwd_bypass_session(s) (s->flags & SNAT_SESSION_FLAG_FWD_BYPASS)
 516
 517 /** \brief Check if NAT session is endpoint dependent.
 518     @param s NAT session
 519     @return 1 if NAT session is endpoint dependent
 520 */
 521 #define is_ed_session(s) (s->flags & SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT)
 522
 523 #define nat_interface_is_inside(i) i->flags & NAT_INTERFACE_FLAG_IS_INSIDE
 524 #define nat_interface_is_outside(i) i->flags & NAT_INTERFACE_FLAG_IS_OUTSIDE
 525
 526 #define nat_log_err(...) \
 527   vlib_log(VLIB_LOG_LEVEL_ERR, snat_main.log_class, __VA_ARGS__)
 528 #define nat_log_warn(...) \
 529   vlib_log(VLIB_LOG_LEVEL_WARNING, snat_main.log_class, __VA_ARGS__)
 530 #define nat_log_notice(...) \
 531   vlib_log(VLIB_LOG_LEVEL_NOTICE, snat_main.log_class, __VA_ARGS__)
 532 #define nat_log_info(...) \
 533   vlib_log(VLIB_LOG_LEVEL_INFO, snat_main.log_class, __VA_ARGS__)
 534 #define nat_log_debug(...)\
 535   vlib_log(VLIB_LOG_LEVEL_DEBUG, snat_main.log_class, __VA_ARGS__)
 536
 537 /*
 538  * Why is this here? Because we don't need to touch this layer to
 539  * simply reply to an icmp. We need to change id to a unique
 540  * value to NAT an echo request/reply.
 541  */
 542
 543 typedef struct {
 544   u16 identifier;
 545   u16 sequence;
 546 } icmp_echo_header_t;
 547
 548 typedef struct {
 549   u16 src_port, dst_port;
 550 } tcp_udp_header_t;
 551
 552 u32 icmp_match_in2out_fast(snat_main_t *sm, vlib_node_runtime_t *node,
 553                            u32 thread_index, vlib_buffer_t *b0,
 554                            ip4_header_t *ip0, u8 *p_proto,
 555                            snat_session_key_t *p_value,
 556                            u8 *p_dont_translate, void *d, void *e);
 557 u32 icmp_match_in2out_slow(snat_main_t *sm, vlib_node_runtime_t *node,
 558                            u32 thread_index, vlib_buffer_t *b0,
 559                            ip4_header_t *ip0, u8 *p_proto,
 560                            snat_session_key_t *p_value,
 561                            u8 *p_dont_translate, void *d, void *e);
 562 u32 icmp_match_in2out_det(snat_main_t *sm, vlib_node_runtime_t *node,
 563                           u32 thread_index, vlib_buffer_t *b0,
 564                           ip4_header_t *ip0, u8 *p_proto,
 565                           snat_session_key_t *p_value,
 566                           u8 *p_dont_translate, void *d, void *e);
 567 u32 icmp_match_in2out_ed(snat_main_t *sm, vlib_node_runtime_t *node,
 568                          u32 thread_index, vlib_buffer_t *b0,
 569                          ip4_header_t *ip0, u8 *p_proto,
 570                          snat_session_key_t *p_value,
 571                          u8 *p_dont_translate, void *d, void *e);
 572 u32 icmp_match_out2in_fast(snat_main_t *sm, vlib_node_runtime_t *node,
 573                            u32 thread_index, vlib_buffer_t *b0,
 574                            ip4_header_t *ip0, u8 *p_proto,
 575                            snat_session_key_t *p_value,
 576                            u8 *p_dont_translate, void *d, void *e);
 577 u32 icmp_match_out2in_slow(snat_main_t *sm, vlib_node_runtime_t *node,
 578                            u32 thread_index, vlib_buffer_t *b0,
 579                            ip4_header_t *ip0, u8 *p_proto,
 580                            snat_session_key_t *p_value,
 581                            u8 *p_dont_translate, void *d, void *e);
 582 u32 icmp_match_out2in_det(snat_main_t *sm, vlib_node_runtime_t *node,
 583                           u32 thread_index, vlib_buffer_t *b0,
 584                           ip4_header_t *ip0, u8 *p_proto,
 585                           snat_session_key_t *p_value,
 586                           u8 *p_dont_translate, void *d, void *e);
 587 u32 icmp_match_out2in_ed(snat_main_t *sm, vlib_node_runtime_t *node,
 588                          u32 thread_index, vlib_buffer_t *b0,
 589                          ip4_header_t *ip0, u8 *p_proto,
 590                          snat_session_key_t *p_value,
 591                          u8 *p_dont_translate, void *d, void *e);
 592 void increment_v4_address(ip4_address_t * a);
 593 int snat_add_address(snat_main_t *sm, ip4_address_t *addr, u32 vrf_id,
 594                      u8 twice_nat);
 595 int snat_del_address(snat_main_t *sm, ip4_address_t addr, u8 delete_sm,
 596                      u8 twice_nat);
 597 void nat44_add_del_address_dpo (ip4_address_t addr, u8 is_add);
 598 int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
 599                             u16 l_port, u16 e_port, u32 vrf_id, int addr_only,
 600                             u32 sw_if_index, snat_protocol_t proto, int is_add,
 601                             twice_nat_type_t twice_nat, u8 out2in_only,
 602                             u8 *tag);
 603 clib_error_t * snat_api_init(vlib_main_t * vm, snat_main_t * sm);
 604 int snat_set_workers (uword * bitmap);
 605 int snat_interface_add_del(u32 sw_if_index, u8 is_inside, int is_del);
 606 int snat_interface_add_del_output_feature(u32 sw_if_index, u8 is_inside,
 607                                           int is_del);
 608 int snat_add_interface_address(snat_main_t *sm, u32 sw_if_index, int is_del,
 609                                u8 twice_nat);
 610 uword unformat_snat_protocol(unformat_input_t * input, va_list * args);
 611 u8 * format_snat_protocol(u8 * s, va_list * args);
 612 int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
 613                                      snat_protocol_t proto, u32 vrf_id,
 614                                      nat44_lb_addr_port_t *locals, u8 is_add,
 615                                      twice_nat_type_t twice_nat, u8 out2in_only,
 616                                      u8 *tag);
 617 int nat44_del_session (snat_main_t *sm, ip4_address_t *addr, u16 port,
 618                        snat_protocol_t proto, u32 vrf_id, int is_in);
 619 int nat44_del_ed_session (snat_main_t *sm, ip4_address_t *addr, u16 port,
 620                           ip4_address_t *eh_addr, u16 eh_port, u8 proto,
 621                           u32 vrf_id, int is_in);
 622 void nat_free_session_data (snat_main_t * sm, snat_session_t * s,
 623                             u32 thread_index);
 624 snat_user_t * nat_user_get_or_create (snat_main_t *sm, ip4_address_t *addr,
 625                                       u32 fib_index, u32 thread_index);
 626 snat_session_t * nat_session_alloc_or_recycle (snat_main_t *sm, snat_user_t *u,
 627                                                u32 thread_index);
 628 void nat_set_alloc_addr_and_port_mape (u16 psid, u16 psid_offset,
 629                                        u16 psid_length);
 630 void nat_set_alloc_addr_and_port_default (void);
 631
 632 #endif /* __included_snat_h__ */