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