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
  32
  33 #define SNAT_UDP_TIMEOUT 300
  34 #define SNAT_UDP_TIMEOUT_MIN 120
  35 #define SNAT_TCP_TRANSITORY_TIMEOUT 240
  36 #define SNAT_TCP_ESTABLISHED_TIMEOUT 7440
  37 #define SNAT_TCP_INCOMING_SYN 6
  38 #define SNAT_ICMP_TIMEOUT 60
  39
  40 #define SNAT_FLAG_HAIRPINNING (1 << 0)
  41
  42 /* Key */
  43 typedef struct {
  44   union
  45   {
  46     struct
  47     {
  48       ip4_address_t addr;
  49       u16 port;
  50       u16 protocol:3,
  51         fib_index:13;
  52     };
  53     u64 as_u64;
  54   };
  55 } snat_session_key_t;
  56
  57 typedef struct {
  58   union
  59   {
  60     struct
  61     {
  62       ip4_address_t l_addr;
  63       ip4_address_t r_addr;
  64       u32 proto:8,
  65           fib_index:24;
  66       u16 l_port;
  67       u16 r_port;
  68     };
  69     u64 as_u64[2];
  70   };
  71 } nat_ed_ses_key_t;
  72
  73 typedef struct {
  74   union
  75   {
  76     struct
  77     {
  78       ip4_address_t ext_host_addr;
  79       u16 ext_host_port;
  80       u16 out_port;
  81     };
  82     u64 as_u64;
  83   };
  84 } snat_det_out_key_t;
  85
  86 typedef struct {
  87   union
  88   {
  89     struct
  90     {
  91       ip4_address_t addr;
  92       u32 fib_index;
  93     };
  94     u64 as_u64;
  95   };
  96 } snat_user_key_t;
  97
  98
  99 #define foreach_snat_protocol \
 100   _(UDP, 0, udp, "udp")       \
 101   _(TCP, 1, tcp, "tcp")       \
 102   _(ICMP, 2, icmp, "icmp")
 103
 104 typedef enum {
 105 #define _(N, i, n, s) SNAT_PROTOCOL_##N = i,
 106   foreach_snat_protocol
 107 #undef _
 108 } snat_protocol_t;
 109
 110
 111 #define foreach_snat_session_state          \
 112   _(0, UNKNOWN, "unknown")                 \
 113   _(1, UDP_ACTIVE, "udp-active")           \
 114   _(2, TCP_SYN_SENT, "tcp-syn-sent")       \
 115   _(3, TCP_ESTABLISHED, "tcp-established") \
 116   _(4, TCP_FIN_WAIT, "tcp-fin-wait")       \
 117   _(5, TCP_CLOSE_WAIT, "tcp-close-wait")   \
 118   _(6, TCP_CLOSING, "tcp-closing")         \
 119   _(7, TCP_LAST_ACK, "tcp-last-ack")       \
 120   _(8, TCP_CLOSED, "tcp-closed")           \
 121   _(9, ICMP_ACTIVE, "icmp-active")
 122
 123 typedef enum {
 124 #define _(v, N, s) SNAT_SESSION_##N = v,
 125   foreach_snat_session_state
 126 #undef _
 127 } snat_session_state_t;
 128
 129
 130 #define SNAT_SESSION_FLAG_STATIC_MAPPING       1
 131 #define SNAT_SESSION_FLAG_UNKNOWN_PROTO        2
 132 #define SNAT_SESSION_FLAG_LOAD_BALANCING       4
 133 #define SNAT_SESSION_FLAG_TWICE_NAT            8
 134 #define SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT   16
 135 #define SNAT_SESSION_FLAG_FWD_BYPASS           32
 136
 137 #define NAT_INTERFACE_FLAG_IS_INSIDE 1
 138 #define NAT_INTERFACE_FLAG_IS_OUTSIDE 2
 139
 140 typedef CLIB_PACKED(struct {
 141   snat_session_key_t out2in;    /* 0-15 */
 142
 143   snat_session_key_t in2out;    /* 16-31 */
 144
 145   u32 flags;                    /* 32-35 */
 146
 147   /* per-user translations */
 148   u32 per_user_index;           /* 36-39 */
 149
 150   u32 per_user_list_head_index; /* 40-43 */
 151
 152   /* Last heard timer */
 153   f64 last_heard;               /* 44-51 */
 154
 155   u64 total_bytes;              /* 52-59 */
 156
 157   u32 total_pkts;               /* 60-63 */
 158
 159   /* Outside address */
 160   u32 outside_address_index;    /* 64-67 */
 161
 162   /* External host address and port */
 163   ip4_address_t ext_host_addr;  /* 68-71 */
 164   u16 ext_host_port;            /* 72-73 */
 165
 166   /* External hos address and port after translation */
 167   ip4_address_t ext_host_nat_addr; /* 74-77 */
 168   u16 ext_host_nat_port;           /* 78-79 */
 169
 170   /* TCP session state */
 171   u8 state;
 172 }) snat_session_t;
 173
 174
 175 typedef struct {
 176   ip4_address_t addr;
 177   u32 fib_index;
 178   u32 sessions_per_user_list_head_index;
 179   u32 nsessions;
 180   u32 nstaticsessions;
 181 } snat_user_t;
 182
 183 typedef struct {
 184   ip4_address_t addr;
 185   u32 fib_index;
 186 #define _(N, i, n, s) \
 187   u16 busy_##n##_ports; \
 188   u16 * busy_##n##_ports_per_thread; \
 189   uword * busy_##n##_port_bitmap;
 190   foreach_snat_protocol
 191 #undef _
 192 } snat_address_t;
 193
 194 typedef struct {
 195   u16 in_port;
 196   snat_det_out_key_t out;
 197   u8 state;
 198   u32 expire;
 199 } snat_det_session_t;
 200
 201 typedef struct {
 202   ip4_address_t in_addr;
 203   u8 in_plen;
 204   ip4_address_t out_addr;
 205   u8 out_plen;
 206   u32 sharing_ratio;
 207   u16 ports_per_host;
 208   u32 ses_num;
 209   /* vector of sessions */
 210   snat_det_session_t * sessions;
 211 } snat_det_map_t;
 212
 213 typedef struct {
 214   ip4_address_t addr;
 215   u16 port;
 216   u8 probability;
 217   u8 prefix;
 218 } nat44_lb_addr_port_t;
 219
 220 typedef enum {
 221   TWICE_NAT_DISABLED,
 222   TWICE_NAT,
 223   TWICE_NAT_SELF,
 224 } twice_nat_type_t;
 225
 226 typedef struct {
 227   ip4_address_t local_addr;
 228   ip4_address_t external_addr;
 229   u16 local_port;
 230   u16 external_port;
 231   u8 addr_only;
 232   twice_nat_type_t twice_nat;
 233   u8 out2in_only;
 234   u32 vrf_id;
 235   u32 fib_index;
 236   snat_protocol_t proto;
 237   u32 worker_index;
 238   u8 *tag;
 239   nat44_lb_addr_port_t *locals;
 240 } snat_static_mapping_t;
 241
 242 typedef struct {
 243   u32 sw_if_index;
 244   u8 flags;
 245 } snat_interface_t;
 246
 247 typedef struct {
 248   ip4_address_t l_addr;
 249   u16 l_port;
 250   u16 e_port;
 251   u32 sw_if_index;
 252   u32 vrf_id;
 253   snat_protocol_t proto;
 254   int addr_only;
 255   int twice_nat;
 256   int is_add;
 257   u8 *tag;
 258 } snat_static_map_resolve_t;
 259
 260 typedef struct {
 261   /* Main lookup tables */
 262   clib_bihash_8_8_t out2in;
 263   clib_bihash_8_8_t in2out;
 264
 265   /* Find-a-user => src address lookup */
 266   clib_bihash_8_8_t user_hash;
 267
 268   /* User pool */
 269   snat_user_t * users;
 270
 271   /* Session pool */
 272   snat_session_t * sessions;
 273
 274   /* Pool of doubly-linked list elements */
 275   dlist_elt_t * list_pool;
 276
 277   u32 snat_thread_index;
 278 } snat_main_per_thread_data_t;
 279
 280 struct snat_main_s;
 281
 282 typedef u32 snat_icmp_match_function_t (struct snat_main_s *sm,
 283                                         vlib_node_runtime_t *node,
 284                                         u32 thread_index,
 285                                         vlib_buffer_t *b0,
 286                                         ip4_header_t *ip0,
 287                                         u8 *p_proto,
 288                                         snat_session_key_t *p_value,
 289                                         u8 *p_dont_translate,
 290                                         void *d,
 291                                         void *e);
 292
 293 typedef u32 (snat_get_worker_function_t) (ip4_header_t * ip, u32 rx_fib_index);
 294
 295 typedef int nat_alloc_out_addr_and_port_function_t (snat_address_t * addresses,
 296                                                     u32 fib_index,
 297                                                     u32 thread_index,
 298                                                     snat_session_key_t * k,
 299                                                     u32 * address_indexp,
 300                                                     u16 port_per_thread,
 301                                                     u32 snat_thread_index);
 302
 303 typedef struct snat_main_s {
 304   /* Endpoint address dependent sessions lookup tables */
 305   clib_bihash_16_8_t out2in_ed;
 306   clib_bihash_16_8_t in2out_ed;
 307
 308   snat_icmp_match_function_t * icmp_match_in2out_cb;
 309   snat_icmp_match_function_t * icmp_match_out2in_cb;
 310
 311   u32 num_workers;
 312   u32 first_worker_index;
 313   u32 next_worker;
 314   u32 * workers;
 315   snat_get_worker_function_t * worker_in2out_cb;
 316   snat_get_worker_function_t * worker_out2in_cb;
 317   u16 port_per_thread;
 318   u32 num_snat_thread;
 319
 320   /* Per thread data */
 321   snat_main_per_thread_data_t * per_thread_data;
 322
 323   /* Find a static mapping by local */
 324   clib_bihash_8_8_t static_mapping_by_local;
 325
 326   /* Find a static mapping by external */
 327   clib_bihash_8_8_t static_mapping_by_external;
 328
 329   /* Static mapping pool */
 330   snat_static_mapping_t * static_mappings;
 331
 332   /* Interface pool */
 333   snat_interface_t * interfaces;
 334   snat_interface_t * output_feature_interfaces;
 335
 336   /* Vector of outside addresses */
 337   snat_address_t * addresses;
 338   nat_alloc_out_addr_and_port_function_t *alloc_addr_and_port;
 339   u8 psid_offset;
 340   u8 psid_length;
 341   u16 psid;
 342
 343   /* Vector of twice NAT addresses for extenal hosts */
 344   snat_address_t * twice_nat_addresses;
 345
 346   /* sw_if_indices whose intfc addresses should be auto-added */
 347   u32 * auto_add_sw_if_indices;
 348   u32 * auto_add_sw_if_indices_twice_nat;
 349
 350   /* vector of interface address static mappings to resolve. */
 351   snat_static_map_resolve_t *to_resolve;
 352
 353   /* Randomize port allocation order */
 354   u32 random_seed;
 355
 356   /* Worker handoff index */
 357   u32 fq_in2out_index;
 358   u32 fq_in2out_output_index;
 359   u32 fq_out2in_index;
 360
 361   /* in2out and out2in node index */
 362   u32 in2out_node_index;
 363   u32 in2out_output_node_index;
 364   u32 out2in_node_index;
 365
 366   /* Deterministic NAT */
 367   snat_det_map_t * det_maps;
 368
 369   /* If forwarding is enabled */
 370   u8 forwarding_enabled;
 371
 372   /* Config parameters */
 373   u8 static_mapping_only;
 374   u8 static_mapping_connection_tracking;
 375   u8 deterministic;
 376   u8 out2in_dpo;
 377   u32 translation_buckets;
 378   u32 translation_memory_size;
 379   u32 max_translations;
 380   u32 user_buckets;
 381   u32 user_memory_size;
 382   u32 max_translations_per_user;
 383   u32 outside_vrf_id;
 384   u32 outside_fib_index;
 385   u32 inside_vrf_id;
 386   u32 inside_fib_index;
 387
 388   /* values of various timeouts */
 389   u32 udp_timeout;
 390   u32 tcp_established_timeout;
 391   u32 tcp_transitory_timeout;
 392   u32 icmp_timeout;
 393
 394   /* API message ID base */
 395   u16 msg_id_base;
 396
 397   /* convenience */
 398   vlib_main_t * vlib_main;
 399   vnet_main_t * vnet_main;
 400   ip4_main_t * ip4_main;
 401   ip_lookup_main_t * ip4_lookup_main;
 402   api_main_t * api_main;
 403 } snat_main_t;
 404
 405 extern snat_main_t snat_main;
 406 extern vlib_node_registration_t snat_in2out_node;
 407 extern vlib_node_registration_t snat_in2out_output_node;
 408 extern vlib_node_registration_t snat_out2in_node;
 409 extern vlib_node_registration_t snat_in2out_fast_node;
 410 extern vlib_node_registration_t snat_out2in_fast_node;
 411 extern vlib_node_registration_t snat_in2out_worker_handoff_node;
 412 extern vlib_node_registration_t snat_in2out_output_worker_handoff_node;
 413 extern vlib_node_registration_t snat_out2in_worker_handoff_node;
 414 extern vlib_node_registration_t snat_det_in2out_node;
 415 extern vlib_node_registration_t snat_det_out2in_node;
 416 extern vlib_node_registration_t snat_hairpin_dst_node;
 417 extern vlib_node_registration_t snat_hairpin_src_node;
 418
 419 void snat_free_outside_address_and_port (snat_address_t * addresses,
 420                                          u32 thread_index,
 421                                          snat_session_key_t * k,
 422                                          u32 address_index);
 423
 424 int snat_alloc_outside_address_and_port (snat_address_t * addresses,
 425                                          u32 fib_index,
 426                                          u32 thread_index,
 427                                          snat_session_key_t * k,
 428                                          u32 * address_indexp,
 429                                          u16 port_per_thread,
 430                                          u32 snat_thread_index);
 431
 432 int snat_static_mapping_match (snat_main_t * sm,
 433                                snat_session_key_t match,
 434                                snat_session_key_t * mapping,
 435                                u8 by_external,
 436                                u8 *is_addr_only,
 437                                twice_nat_type_t *twice_nat,
 438                                u8 *lb);
 439
 440 void snat_add_del_addr_to_fib (ip4_address_t * addr,
 441                                u8 p_len,
 442                                u32 sw_if_index,
 443                                int is_add);
 444
 445 format_function_t format_snat_user;
 446 format_function_t format_snat_static_mapping;
 447 format_function_t format_snat_static_map_to_resolve;
 448 format_function_t format_det_map_ses;
 449
 450 typedef struct {
 451   u32 cached_sw_if_index;
 452   u32 cached_ip4_address;
 453 } snat_runtime_t;
 454
 455 /** \brief Check if SNAT session is created from static mapping.
 456     @param s SNAT session
 457     @return 1 if SNAT session is created from static mapping otherwise 0
 458 */
 459 #define snat_is_session_static(s) (s->flags & SNAT_SESSION_FLAG_STATIC_MAPPING)
 460
 461 /** \brief Check if SNAT session for unknown protocol.
 462     @param s SNAT session
 463     @return 1 if SNAT session for unknown protocol otherwise 0
 464 */
 465 #define snat_is_unk_proto_session(s) (s->flags & SNAT_SESSION_FLAG_UNKNOWN_PROTO)
 466
 467 /** \brief Check if NAT session is twice NAT.
 468     @param s NAT session
 469     @return 1 if NAT session is twice NAT
 470 */
 471 #define is_twice_nat_session(s) (s->flags & SNAT_SESSION_FLAG_TWICE_NAT)
 472
 473 /** \brief Check if NAT session is load-balancing.
 474     @param s NAT session
 475     @return 1 if NAT session is load-balancing
 476 */
 477 #define is_lb_session(s) (s->flags & SNAT_SESSION_FLAG_LOAD_BALANCING)
 478
 479 /** \brief Check if NAT session is forwarding bypass.
 480     @param s NAT session
 481     @return 1 if NAT session is load-balancing
 482 */
 483 #define is_fwd_bypass_session(s) (s->flags & SNAT_SESSION_FLAG_FWD_BYPASS)
 484
 485 /** \brief Check if NAT session is endpoint dependent.
 486     @param s NAT session
 487     @return 1 if NAT session is endpoint dependent
 488 */
 489 #define is_ed_session(s) (s->flags & SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT)
 490
 491 #define nat_interface_is_inside(i) i->flags & NAT_INTERFACE_FLAG_IS_INSIDE
 492 #define nat_interface_is_outside(i) i->flags & NAT_INTERFACE_FLAG_IS_OUTSIDE
 493
 494 /*
 495  * Why is this here? Because we don't need to touch this layer to
 496  * simply reply to an icmp. We need to change id to a unique
 497  * value to NAT an echo request/reply.
 498  */
 499
 500 typedef struct {
 501   u16 identifier;
 502   u16 sequence;
 503 } icmp_echo_header_t;
 504
 505 always_inline u32
 506 ip_proto_to_snat_proto (u8 ip_proto)
 507 {
 508   u32 snat_proto = ~0;
 509
 510   snat_proto = (ip_proto == IP_PROTOCOL_UDP) ? SNAT_PROTOCOL_UDP : snat_proto;
 511   snat_proto = (ip_proto == IP_PROTOCOL_TCP) ? SNAT_PROTOCOL_TCP : snat_proto;
 512   snat_proto = (ip_proto == IP_PROTOCOL_ICMP) ? SNAT_PROTOCOL_ICMP : snat_proto;
 513   snat_proto = (ip_proto == IP_PROTOCOL_ICMP6) ? SNAT_PROTOCOL_ICMP : snat_proto;
 514
 515   return snat_proto;
 516 }
 517
 518 always_inline u8
 519 snat_proto_to_ip_proto (snat_protocol_t snat_proto)
 520 {
 521   u8 ip_proto = ~0;
 522
 523   ip_proto = (snat_proto == SNAT_PROTOCOL_UDP) ? IP_PROTOCOL_UDP : ip_proto;
 524   ip_proto = (snat_proto == SNAT_PROTOCOL_TCP) ? IP_PROTOCOL_TCP : ip_proto;
 525   ip_proto = (snat_proto == SNAT_PROTOCOL_ICMP) ? IP_PROTOCOL_ICMP : ip_proto;
 526
 527   return ip_proto;
 528 }
 529
 530 typedef struct {
 531   u16 src_port, dst_port;
 532 } tcp_udp_header_t;
 533
 534 u32 icmp_match_in2out_fast(snat_main_t *sm, vlib_node_runtime_t *node,
 535                            u32 thread_index, vlib_buffer_t *b0,
 536                            ip4_header_t *ip0, u8 *p_proto,
 537                            snat_session_key_t *p_value,
 538                            u8 *p_dont_translate, void *d, void *e);
 539 u32 icmp_match_in2out_slow(snat_main_t *sm, vlib_node_runtime_t *node,
 540                            u32 thread_index, vlib_buffer_t *b0,
 541                            ip4_header_t *ip0, u8 *p_proto,
 542                            snat_session_key_t *p_value,
 543                            u8 *p_dont_translate, void *d, void *e);
 544 u32 icmp_match_in2out_det(snat_main_t *sm, vlib_node_runtime_t *node,
 545                           u32 thread_index, vlib_buffer_t *b0,
 546                           ip4_header_t *ip0, u8 *p_proto,
 547                           snat_session_key_t *p_value,
 548                           u8 *p_dont_translate, void *d, void *e);
 549 u32 icmp_match_out2in_fast(snat_main_t *sm, vlib_node_runtime_t *node,
 550                            u32 thread_index, vlib_buffer_t *b0,
 551                            ip4_header_t *ip0, u8 *p_proto,
 552                            snat_session_key_t *p_value,
 553                            u8 *p_dont_translate, void *d, void *e);
 554 u32 icmp_match_out2in_slow(snat_main_t *sm, vlib_node_runtime_t *node,
 555                            u32 thread_index, vlib_buffer_t *b0,
 556                            ip4_header_t *ip0, u8 *p_proto,
 557                            snat_session_key_t *p_value,
 558                            u8 *p_dont_translate, void *d, void *e);
 559 u32 icmp_match_out2in_det(snat_main_t *sm, vlib_node_runtime_t *node,
 560                           u32 thread_index, vlib_buffer_t *b0,
 561                           ip4_header_t *ip0, u8 *p_proto,
 562                           snat_session_key_t *p_value,
 563                           u8 *p_dont_translate, void *d, void *e);
 564 void increment_v4_address(ip4_address_t * a);
 565 void snat_add_address(snat_main_t *sm, ip4_address_t *addr, u32 vrf_id,
 566                       u8 twice_nat);
 567 int snat_del_address(snat_main_t *sm, ip4_address_t addr, u8 delete_sm,
 568                      u8 twice_nat);
 569 void nat44_add_del_address_dpo (ip4_address_t addr, u8 is_add);
 570 int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
 571                             u16 l_port, u16 e_port, u32 vrf_id, int addr_only,
 572                             u32 sw_if_index, snat_protocol_t proto, int is_add,
 573                             twice_nat_type_t twice_nat, u8 out2in_only,
 574                             u8 *tag);
 575 clib_error_t * snat_api_init(vlib_main_t * vm, snat_main_t * sm);
 576 int snat_set_workers (uword * bitmap);
 577 int snat_interface_add_del(u32 sw_if_index, u8 is_inside, int is_del);
 578 int snat_interface_add_del_output_feature(u32 sw_if_index, u8 is_inside,
 579                                           int is_del);
 580 int snat_add_interface_address(snat_main_t *sm, u32 sw_if_index, int is_del,
 581                                u8 twice_nat);
 582 uword unformat_snat_protocol(unformat_input_t * input, va_list * args);
 583 u8 * format_snat_protocol(u8 * s, va_list * args);
 584 int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
 585                                      snat_protocol_t proto, u32 vrf_id,
 586                                      nat44_lb_addr_port_t *locals, u8 is_add,
 587                                      twice_nat_type_t twice_nat, u8 out2in_only,
 588                                      u8 *tag);
 589 int nat44_del_session (snat_main_t *sm, ip4_address_t *addr, u16 port,
 590                        snat_protocol_t proto, u32 vrf_id, int is_in);
 591 void nat_free_session_data (snat_main_t * sm, snat_session_t * s,
 592                             u32 thread_index);
 593 snat_user_t * nat_user_get_or_create (snat_main_t *sm, ip4_address_t *addr,
 594                                       u32 fib_index, u32 thread_index);
 595 snat_session_t * nat_session_alloc_or_recycle (snat_main_t *sm, snat_user_t *u,
 596                                                u32 thread_index);
 597 void nat_set_alloc_addr_and_port_mape (u16 psid, u16 psid_offset,
 598                                        u16 psid_length);
 599 void nat_set_alloc_addr_and_port_default (void);
 600
 601 static_always_inline u8
 602 icmp_is_error_message (icmp46_header_t * icmp)
 603 {
 604   switch(icmp->type)
 605     {
 606     case ICMP4_destination_unreachable:
 607     case ICMP4_time_exceeded:
 608     case ICMP4_parameter_problem:
 609     case ICMP4_source_quench:
 610     case ICMP4_redirect:
 611     case ICMP4_alternate_host_address:
 612       return 1;
 613     }
 614   return 0;
 615 }
 616
 617 static_always_inline u8
 618 is_interface_addr(snat_main_t *sm, vlib_node_runtime_t *node, u32 sw_if_index0,
 619                   u32 ip4_addr)
 620 {
 621   snat_runtime_t *rt = (snat_runtime_t *) node->runtime_data;
 622   ip4_address_t * first_int_addr;
 623
 624   if (PREDICT_FALSE(rt->cached_sw_if_index != sw_if_index0))
 625     {
 626       first_int_addr =
 627         ip4_interface_first_address (sm->ip4_main, sw_if_index0,
 628                                      0 /* just want the address */);
 629       rt->cached_sw_if_index = sw_if_index0;
 630       if (first_int_addr)
 631         rt->cached_ip4_address = first_int_addr->as_u32;
 632       else
 633         rt->cached_ip4_address = 0;
 634     }
 635
 636   if (PREDICT_FALSE(ip4_addr == rt->cached_ip4_address))
 637     return 1;
 638   else
 639     return 0;
 640 }
 641
 642 always_inline u8
 643 maximum_sessions_exceeded (snat_main_t *sm, u32 thread_index)
 644 {
 645   if (pool_elts (sm->per_thread_data[thread_index].sessions) >= sm->max_translations)
 646     return 1;
 647
 648   return 0;
 649 }
 650
 651 static_always_inline void
 652 nat_send_all_to_node(vlib_main_t *vm, u32 *bi_vector,
 653                      vlib_node_runtime_t *node, vlib_error_t *error, u32 next)
 654 {
 655   u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
 656
 657   from = bi_vector;
 658   n_left_from = vec_len(bi_vector);
 659   next_index = node->cached_next_index;
 660   while (n_left_from > 0) {
 661     vlib_get_next_frame(vm, node, next_index, to_next, n_left_to_next);
 662     while (n_left_from > 0 && n_left_to_next > 0) {
 663       u32 bi0 = to_next[0] = from[0];
 664       from += 1;
 665       n_left_from -= 1;
 666       to_next += 1;
 667       n_left_to_next -= 1;
 668       vlib_buffer_t *p0 = vlib_get_buffer(vm, bi0);
 669       p0->error = *error;
 670       vlib_validate_buffer_enqueue_x1(vm, node, next_index, to_next,
 671                                       n_left_to_next, bi0, next);
 672     }
 673     vlib_put_next_frame(vm, node, next_index, n_left_to_next);
 674   }
 675 }
 676
 677 always_inline void
 678 user_session_increment(snat_main_t *sm, snat_user_t *u, u8 is_static)
 679 {
 680   if (u->nsessions + u->nstaticsessions < sm->max_translations_per_user)
 681     {
 682       if (is_static)
 683         u->nstaticsessions++;
 684       else
 685         u->nsessions++;
 686     }
 687 }
 688
 689 always_inline void
 690 nat44_set_tcp_session_state(snat_main_t * sm, snat_session_t * ses,
 691                             tcp_header_t * tcp, u32 thread_index)
 692 {
 693   if (tcp->flags & TCP_FLAG_FIN && ses->state == SNAT_SESSION_UNKNOWN)
 694     ses->state = SNAT_SESSION_TCP_FIN_WAIT;
 695   else if (tcp->flags & TCP_FLAG_FIN && ses->state == SNAT_SESSION_TCP_FIN_WAIT)
 696     ses->state = SNAT_SESSION_TCP_CLOSING;
 697   else if (tcp->flags & TCP_FLAG_ACK && ses->state == SNAT_SESSION_TCP_FIN_WAIT)
 698     ses->state = SNAT_SESSION_TCP_CLOSE_WAIT;
 699   else if (tcp->flags & TCP_FLAG_FIN && ses->state == SNAT_SESSION_TCP_CLOSE_WAIT)
 700     ses->state = SNAT_SESSION_TCP_LAST_ACK;
 701   else if (tcp->flags & TCP_FLAG_ACK && ses->state == SNAT_SESSION_TCP_CLOSING)
 702     ses->state = SNAT_SESSION_TCP_LAST_ACK;
 703   else if (tcp->flags & TCP_FLAG_ACK && ses->state == SNAT_SESSION_TCP_LAST_ACK)
 704     {
 705       nat_free_session_data (sm, ses, thread_index);
 706       ses->state = SNAT_SESSION_TCP_CLOSED;
 707     }
 708 }
 709
 710 #endif /* __included_snat_h__ */