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 #define NAT44_SES_I2O_FIN 1
 130 #define NAT44_SES_O2I_FIN 2
 131 #define NAT44_SES_I2O_FIN_ACK 4
 132 #define NAT44_SES_O2I_FIN_ACK 8
 133
 134 #define nat44_is_ses_closed(s) (s->state == 0xf)
 135
 136 #define SNAT_SESSION_FLAG_STATIC_MAPPING       1
 137 #define SNAT_SESSION_FLAG_UNKNOWN_PROTO        2
 138 #define SNAT_SESSION_FLAG_LOAD_BALANCING       4
 139 #define SNAT_SESSION_FLAG_TWICE_NAT            8
 140 #define SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT   16
 141 #define SNAT_SESSION_FLAG_FWD_BYPASS           32
 142
 143 #define NAT_INTERFACE_FLAG_IS_INSIDE 1
 144 #define NAT_INTERFACE_FLAG_IS_OUTSIDE 2
 145
 146 typedef CLIB_PACKED(struct {
 147   snat_session_key_t out2in;    /* 0-15 */
 148
 149   snat_session_key_t in2out;    /* 16-31 */
 150
 151   u32 flags;                    /* 32-35 */
 152
 153   /* per-user translations */
 154   u32 per_user_index;           /* 36-39 */
 155
 156   u32 per_user_list_head_index; /* 40-43 */
 157
 158   /* Last heard timer */
 159   f64 last_heard;               /* 44-51 */
 160
 161   u64 total_bytes;              /* 52-59 */
 162
 163   u32 total_pkts;               /* 60-63 */
 164
 165   /* Outside address */
 166   u32 outside_address_index;    /* 64-67 */
 167
 168   /* External host address and port */
 169   ip4_address_t ext_host_addr;  /* 68-71 */
 170   u16 ext_host_port;            /* 72-73 */
 171
 172   /* External hos address and port after translation */
 173   ip4_address_t ext_host_nat_addr; /* 74-77 */
 174   u16 ext_host_nat_port;           /* 78-79 */
 175
 176   /* TCP session state */
 177   u8 state;
 178   u32 i2o_fin_seq;
 179   u32 o2i_fin_seq;
 180 }) snat_session_t;
 181
 182
 183 typedef struct {
 184   ip4_address_t addr;
 185   u32 fib_index;
 186   u32 sessions_per_user_list_head_index;
 187   u32 nsessions;
 188   u32 nstaticsessions;
 189 } snat_user_t;
 190
 191 typedef struct {
 192   ip4_address_t addr;
 193   u32 fib_index;
 194 #define _(N, i, n, s) \
 195   u16 busy_##n##_ports; \
 196   u16 * busy_##n##_ports_per_thread; \
 197   uword * busy_##n##_port_bitmap;
 198   foreach_snat_protocol
 199 #undef _
 200 } snat_address_t;
 201
 202 typedef struct {
 203   u16 in_port;
 204   snat_det_out_key_t out;
 205   u8 state;
 206   u32 expire;
 207 } snat_det_session_t;
 208
 209 typedef struct {
 210   ip4_address_t in_addr;
 211   u8 in_plen;
 212   ip4_address_t out_addr;
 213   u8 out_plen;
 214   u32 sharing_ratio;
 215   u16 ports_per_host;
 216   u32 ses_num;
 217   /* vector of sessions */
 218   snat_det_session_t * sessions;
 219 } snat_det_map_t;
 220
 221 typedef struct {
 222   ip4_address_t addr;
 223   u16 port;
 224   u8 probability;
 225   u8 prefix;
 226 } nat44_lb_addr_port_t;
 227
 228 typedef enum {
 229   TWICE_NAT_DISABLED,
 230   TWICE_NAT,
 231   TWICE_NAT_SELF,
 232 } twice_nat_type_t;
 233
 234 typedef struct {
 235   ip4_address_t local_addr;
 236   ip4_address_t external_addr;
 237   u16 local_port;
 238   u16 external_port;
 239   u8 addr_only;
 240   twice_nat_type_t twice_nat;
 241   u8 out2in_only;
 242   u32 vrf_id;
 243   u32 fib_index;
 244   snat_protocol_t proto;
 245   u32 worker_index;
 246   u8 *tag;
 247   nat44_lb_addr_port_t *locals;
 248 } snat_static_mapping_t;
 249
 250 typedef struct {
 251   u32 sw_if_index;
 252   u8 flags;
 253 } snat_interface_t;
 254
 255 typedef struct {
 256   ip4_address_t l_addr;
 257   u16 l_port;
 258   u16 e_port;
 259   u32 sw_if_index;
 260   u32 vrf_id;
 261   snat_protocol_t proto;
 262   int addr_only;
 263   int twice_nat;
 264   int is_add;
 265   u8 *tag;
 266 } snat_static_map_resolve_t;
 267
 268 typedef struct {
 269   /* Main lookup tables */
 270   clib_bihash_8_8_t out2in;
 271   clib_bihash_8_8_t in2out;
 272
 273   /* Find-a-user => src address lookup */
 274   clib_bihash_8_8_t user_hash;
 275
 276   /* User pool */
 277   snat_user_t * users;
 278
 279   /* Session pool */
 280   snat_session_t * sessions;
 281
 282   /* Pool of doubly-linked list elements */
 283   dlist_elt_t * list_pool;
 284
 285   u32 snat_thread_index;
 286 } snat_main_per_thread_data_t;
 287
 288 struct snat_main_s;
 289
 290 typedef u32 snat_icmp_match_function_t (struct snat_main_s *sm,
 291                                         vlib_node_runtime_t *node,
 292                                         u32 thread_index,
 293                                         vlib_buffer_t *b0,
 294                                         ip4_header_t *ip0,
 295                                         u8 *p_proto,
 296                                         snat_session_key_t *p_value,
 297                                         u8 *p_dont_translate,
 298                                         void *d,
 299                                         void *e);
 300
 301 typedef u32 (snat_get_worker_function_t) (ip4_header_t * ip, u32 rx_fib_index);
 302
 303 typedef int nat_alloc_out_addr_and_port_function_t (snat_address_t * addresses,
 304                                                     u32 fib_index,
 305                                                     u32 thread_index,
 306                                                     snat_session_key_t * k,
 307                                                     u32 * address_indexp,
 308                                                     u16 port_per_thread,
 309                                                     u32 snat_thread_index);
 310
 311 typedef struct snat_main_s {
 312   /* Endpoint address dependent sessions lookup tables */
 313   clib_bihash_16_8_t out2in_ed;
 314   clib_bihash_16_8_t in2out_ed;
 315
 316   snat_icmp_match_function_t * icmp_match_in2out_cb;
 317   snat_icmp_match_function_t * icmp_match_out2in_cb;
 318
 319   u32 num_workers;
 320   u32 first_worker_index;
 321   u32 next_worker;
 322   u32 * workers;
 323   snat_get_worker_function_t * worker_in2out_cb;
 324   snat_get_worker_function_t * worker_out2in_cb;
 325   u16 port_per_thread;
 326   u32 num_snat_thread;
 327
 328   /* Per thread data */
 329   snat_main_per_thread_data_t * per_thread_data;
 330
 331   /* Find a static mapping by local */
 332   clib_bihash_8_8_t static_mapping_by_local;
 333
 334   /* Find a static mapping by external */
 335   clib_bihash_8_8_t static_mapping_by_external;
 336
 337   /* Static mapping pool */
 338   snat_static_mapping_t * static_mappings;
 339
 340   /* Interface pool */
 341   snat_interface_t * interfaces;
 342   snat_interface_t * output_feature_interfaces;
 343
 344   /* Vector of outside addresses */
 345   snat_address_t * addresses;
 346   nat_alloc_out_addr_and_port_function_t *alloc_addr_and_port;
 347   u8 psid_offset;
 348   u8 psid_length;
 349   u16 psid;
 350
 351   /* Vector of twice NAT addresses for extenal hosts */
 352   snat_address_t * twice_nat_addresses;
 353
 354   /* sw_if_indices whose intfc addresses should be auto-added */
 355   u32 * auto_add_sw_if_indices;
 356   u32 * auto_add_sw_if_indices_twice_nat;
 357
 358   /* vector of interface address static mappings to resolve. */
 359   snat_static_map_resolve_t *to_resolve;
 360
 361   /* Randomize port allocation order */
 362   u32 random_seed;
 363
 364   /* Worker handoff index */
 365   u32 fq_in2out_index;
 366   u32 fq_in2out_output_index;
 367   u32 fq_out2in_index;
 368
 369   /* in2out and out2in node index */
 370   u32 in2out_node_index;
 371   u32 in2out_output_node_index;
 372   u32 out2in_node_index;
 373
 374   /* Deterministic NAT */
 375   snat_det_map_t * det_maps;
 376
 377   /* If forwarding is enabled */
 378   u8 forwarding_enabled;
 379
 380   /* Config parameters */
 381   u8 static_mapping_only;
 382   u8 static_mapping_connection_tracking;
 383   u8 deterministic;
 384   u8 out2in_dpo;
 385   u32 translation_buckets;
 386   u32 translation_memory_size;
 387   u32 max_translations;
 388   u32 user_buckets;
 389   u32 user_memory_size;
 390   u32 max_translations_per_user;
 391   u32 outside_vrf_id;
 392   u32 outside_fib_index;
 393   u32 inside_vrf_id;
 394   u32 inside_fib_index;
 395
 396   /* values of various timeouts */
 397   u32 udp_timeout;
 398   u32 tcp_established_timeout;
 399   u32 tcp_transitory_timeout;
 400   u32 icmp_timeout;
 401
 402   /* API message ID base */
 403   u16 msg_id_base;
 404
 405   /* convenience */
 406   vlib_main_t * vlib_main;
 407   vnet_main_t * vnet_main;
 408   ip4_main_t * ip4_main;
 409   ip_lookup_main_t * ip4_lookup_main;
 410   api_main_t * api_main;
 411 } snat_main_t;
 412
 413 extern snat_main_t snat_main;
 414 extern vlib_node_registration_t snat_in2out_node;
 415 extern vlib_node_registration_t snat_in2out_output_node;
 416 extern vlib_node_registration_t snat_out2in_node;
 417 extern vlib_node_registration_t snat_in2out_fast_node;
 418 extern vlib_node_registration_t snat_out2in_fast_node;
 419 extern vlib_node_registration_t snat_in2out_worker_handoff_node;
 420 extern vlib_node_registration_t snat_in2out_output_worker_handoff_node;
 421 extern vlib_node_registration_t snat_out2in_worker_handoff_node;
 422 extern vlib_node_registration_t snat_det_in2out_node;
 423 extern vlib_node_registration_t snat_det_out2in_node;
 424 extern vlib_node_registration_t snat_hairpin_dst_node;
 425 extern vlib_node_registration_t snat_hairpin_src_node;
 426
 427 void snat_free_outside_address_and_port (snat_address_t * addresses,
 428                                          u32 thread_index,
 429                                          snat_session_key_t * k,
 430                                          u32 address_index);
 431
 432 int snat_alloc_outside_address_and_port (snat_address_t * addresses,
 433                                          u32 fib_index,
 434                                          u32 thread_index,
 435                                          snat_session_key_t * k,
 436                                          u32 * address_indexp,
 437                                          u16 port_per_thread,
 438                                          u32 snat_thread_index);
 439
 440 int snat_static_mapping_match (snat_main_t * sm,
 441                                snat_session_key_t match,
 442                                snat_session_key_t * mapping,
 443                                u8 by_external,
 444                                u8 *is_addr_only,
 445                                twice_nat_type_t *twice_nat,
 446                                u8 *lb);
 447
 448 void snat_add_del_addr_to_fib (ip4_address_t * addr,
 449                                u8 p_len,
 450                                u32 sw_if_index,
 451                                int is_add);
 452
 453 format_function_t format_snat_user;
 454 format_function_t format_snat_static_mapping;
 455 format_function_t format_snat_static_map_to_resolve;
 456 format_function_t format_det_map_ses;
 457
 458 typedef struct {
 459   u32 cached_sw_if_index;
 460   u32 cached_ip4_address;
 461 } snat_runtime_t;
 462
 463 /** \brief Check if SNAT session is created from static mapping.
 464     @param s SNAT session
 465     @return 1 if SNAT session is created from static mapping otherwise 0
 466 */
 467 #define snat_is_session_static(s) (s->flags & SNAT_SESSION_FLAG_STATIC_MAPPING)
 468
 469 /** \brief Check if SNAT session for unknown protocol.
 470     @param s SNAT session
 471     @return 1 if SNAT session for unknown protocol otherwise 0
 472 */
 473 #define snat_is_unk_proto_session(s) (s->flags & SNAT_SESSION_FLAG_UNKNOWN_PROTO)
 474
 475 /** \brief Check if NAT session is twice NAT.
 476     @param s NAT session
 477     @return 1 if NAT session is twice NAT
 478 */
 479 #define is_twice_nat_session(s) (s->flags & SNAT_SESSION_FLAG_TWICE_NAT)
 480
 481 /** \brief Check if NAT session is load-balancing.
 482     @param s NAT session
 483     @return 1 if NAT session is load-balancing
 484 */
 485 #define is_lb_session(s) (s->flags & SNAT_SESSION_FLAG_LOAD_BALANCING)
 486
 487 /** \brief Check if NAT session is forwarding bypass.
 488     @param s NAT session
 489     @return 1 if NAT session is load-balancing
 490 */
 491 #define is_fwd_bypass_session(s) (s->flags & SNAT_SESSION_FLAG_FWD_BYPASS)
 492
 493 /** \brief Check if NAT session is endpoint dependent.
 494     @param s NAT session
 495     @return 1 if NAT session is endpoint dependent
 496 */
 497 #define is_ed_session(s) (s->flags & SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT)
 498
 499 #define nat_interface_is_inside(i) i->flags & NAT_INTERFACE_FLAG_IS_INSIDE
 500 #define nat_interface_is_outside(i) i->flags & NAT_INTERFACE_FLAG_IS_OUTSIDE
 501
 502 /*
 503  * Why is this here? Because we don't need to touch this layer to
 504  * simply reply to an icmp. We need to change id to a unique
 505  * value to NAT an echo request/reply.
 506  */
 507
 508 typedef struct {
 509   u16 identifier;
 510   u16 sequence;
 511 } icmp_echo_header_t;
 512
 513 always_inline u32
 514 ip_proto_to_snat_proto (u8 ip_proto)
 515 {
 516   u32 snat_proto = ~0;
 517
 518   snat_proto = (ip_proto == IP_PROTOCOL_UDP) ? SNAT_PROTOCOL_UDP : snat_proto;
 519   snat_proto = (ip_proto == IP_PROTOCOL_TCP) ? SNAT_PROTOCOL_TCP : snat_proto;
 520   snat_proto = (ip_proto == IP_PROTOCOL_ICMP) ? SNAT_PROTOCOL_ICMP : snat_proto;
 521   snat_proto = (ip_proto == IP_PROTOCOL_ICMP6) ? SNAT_PROTOCOL_ICMP : snat_proto;
 522
 523   return snat_proto;
 524 }
 525
 526 always_inline u8
 527 snat_proto_to_ip_proto (snat_protocol_t snat_proto)
 528 {
 529   u8 ip_proto = ~0;
 530
 531   ip_proto = (snat_proto == SNAT_PROTOCOL_UDP) ? IP_PROTOCOL_UDP : ip_proto;
 532   ip_proto = (snat_proto == SNAT_PROTOCOL_TCP) ? IP_PROTOCOL_TCP : ip_proto;
 533   ip_proto = (snat_proto == SNAT_PROTOCOL_ICMP) ? IP_PROTOCOL_ICMP : ip_proto;
 534
 535   return ip_proto;
 536 }
 537
 538 typedef struct {
 539   u16 src_port, dst_port;
 540 } tcp_udp_header_t;
 541
 542 u32 icmp_match_in2out_fast(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_in2out_slow(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 u32 icmp_match_in2out_det(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_out2in_fast(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_out2in_slow(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_out2in_det(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 void increment_v4_address(ip4_address_t * a);
 573 void snat_add_address(snat_main_t *sm, ip4_address_t *addr, u32 vrf_id,
 574                       u8 twice_nat);
 575 int snat_del_address(snat_main_t *sm, ip4_address_t addr, u8 delete_sm,
 576                      u8 twice_nat);
 577 void nat44_add_del_address_dpo (ip4_address_t addr, u8 is_add);
 578 int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
 579                             u16 l_port, u16 e_port, u32 vrf_id, int addr_only,
 580                             u32 sw_if_index, snat_protocol_t proto, int is_add,
 581                             twice_nat_type_t twice_nat, u8 out2in_only,
 582                             u8 *tag);
 583 clib_error_t * snat_api_init(vlib_main_t * vm, snat_main_t * sm);
 584 int snat_set_workers (uword * bitmap);
 585 int snat_interface_add_del(u32 sw_if_index, u8 is_inside, int is_del);
 586 int snat_interface_add_del_output_feature(u32 sw_if_index, u8 is_inside,
 587                                           int is_del);
 588 int snat_add_interface_address(snat_main_t *sm, u32 sw_if_index, int is_del,
 589                                u8 twice_nat);
 590 uword unformat_snat_protocol(unformat_input_t * input, va_list * args);
 591 u8 * format_snat_protocol(u8 * s, va_list * args);
 592 int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
 593                                      snat_protocol_t proto, u32 vrf_id,
 594                                      nat44_lb_addr_port_t *locals, u8 is_add,
 595                                      twice_nat_type_t twice_nat, u8 out2in_only,
 596                                      u8 *tag);
 597 int nat44_del_session (snat_main_t *sm, ip4_address_t *addr, u16 port,
 598                        snat_protocol_t proto, u32 vrf_id, int is_in);
 599 int nat44_del_ed_session (snat_main_t *sm, ip4_address_t *addr, u16 port,
 600                           ip4_address_t *eh_addr, u16 eh_port, u8 proto,
 601                           u32 vrf_id, int is_in);
 602 void nat_free_session_data (snat_main_t * sm, snat_session_t * s,
 603                             u32 thread_index);
 604 snat_user_t * nat_user_get_or_create (snat_main_t *sm, ip4_address_t *addr,
 605                                       u32 fib_index, u32 thread_index);
 606 snat_session_t * nat_session_alloc_or_recycle (snat_main_t *sm, snat_user_t *u,
 607                                                u32 thread_index);
 608 void nat_set_alloc_addr_and_port_mape (u16 psid, u16 psid_offset,
 609                                        u16 psid_length);
 610 void nat_set_alloc_addr_and_port_default (void);
 611
 612 static_always_inline u8
 613 icmp_is_error_message (icmp46_header_t * icmp)
 614 {
 615   switch(icmp->type)
 616     {
 617     case ICMP4_destination_unreachable:
 618     case ICMP4_time_exceeded:
 619     case ICMP4_parameter_problem:
 620     case ICMP4_source_quench:
 621     case ICMP4_redirect:
 622     case ICMP4_alternate_host_address:
 623       return 1;
 624     }
 625   return 0;
 626 }
 627
 628 static_always_inline u8
 629 is_interface_addr(snat_main_t *sm, vlib_node_runtime_t *node, u32 sw_if_index0,
 630                   u32 ip4_addr)
 631 {
 632   snat_runtime_t *rt = (snat_runtime_t *) node->runtime_data;
 633   ip4_address_t * first_int_addr;
 634
 635   if (PREDICT_FALSE(rt->cached_sw_if_index != sw_if_index0))
 636     {
 637       first_int_addr =
 638         ip4_interface_first_address (sm->ip4_main, sw_if_index0,
 639                                      0 /* just want the address */);
 640       rt->cached_sw_if_index = sw_if_index0;
 641       if (first_int_addr)
 642         rt->cached_ip4_address = first_int_addr->as_u32;
 643       else
 644         rt->cached_ip4_address = 0;
 645     }
 646
 647   if (PREDICT_FALSE(ip4_addr == rt->cached_ip4_address))
 648     return 1;
 649   else
 650     return 0;
 651 }
 652
 653 always_inline u8
 654 maximum_sessions_exceeded (snat_main_t *sm, u32 thread_index)
 655 {
 656   if (pool_elts (sm->per_thread_data[thread_index].sessions) >= sm->max_translations)
 657     return 1;
 658
 659   return 0;
 660 }
 661
 662 static_always_inline void
 663 nat_send_all_to_node(vlib_main_t *vm, u32 *bi_vector,
 664                      vlib_node_runtime_t *node, vlib_error_t *error, u32 next)
 665 {
 666   u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
 667
 668   from = bi_vector;
 669   n_left_from = vec_len(bi_vector);
 670   next_index = node->cached_next_index;
 671   while (n_left_from > 0) {
 672     vlib_get_next_frame(vm, node, next_index, to_next, n_left_to_next);
 673     while (n_left_from > 0 && n_left_to_next > 0) {
 674       u32 bi0 = to_next[0] = from[0];
 675       from += 1;
 676       n_left_from -= 1;
 677       to_next += 1;
 678       n_left_to_next -= 1;
 679       vlib_buffer_t *p0 = vlib_get_buffer(vm, bi0);
 680       p0->error = *error;
 681       vlib_validate_buffer_enqueue_x1(vm, node, next_index, to_next,
 682                                       n_left_to_next, bi0, next);
 683     }
 684     vlib_put_next_frame(vm, node, next_index, n_left_to_next);
 685   }
 686 }
 687
 688 always_inline void
 689 user_session_increment(snat_main_t *sm, snat_user_t *u, u8 is_static)
 690 {
 691   if (u->nsessions + u->nstaticsessions < sm->max_translations_per_user)
 692     {
 693       if (is_static)
 694         u->nstaticsessions++;
 695       else
 696         u->nsessions++;
 697     }
 698 }
 699
 700 always_inline void
 701 nat44_delete_session(snat_main_t * sm, snat_session_t * ses, u32 thread_index)
 702 {
 703   snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
 704                                                        thread_index);
 705   clib_bihash_kv_8_8_t kv, value;
 706   snat_user_key_t u_key;
 707   snat_user_t *u;
 708   u_key.addr = ses->in2out.addr;
 709   u_key.fib_index = ses->in2out.fib_index;
 710   kv.key = u_key.as_u64;
 711   if (!clib_bihash_search_8_8 (&tsm->user_hash, &kv, &value))
 712     {
 713       u = pool_elt_at_index (tsm->users, value.value);
 714       if (snat_is_session_static(ses))
 715         u->nstaticsessions--;
 716       else
 717         u->nsessions--;
 718     }
 719   clib_dlist_remove (tsm->list_pool, ses->per_user_index);
 720   pool_put_index (tsm->list_pool, ses->per_user_index);
 721   pool_put (tsm->sessions, ses);
 722 }
 723
 724 /** \brief Set TCP session state.
 725     @return 1 if session was closed, otherwise 0
 726 */
 727 always_inline int
 728 nat44_set_tcp_session_state_i2o(snat_main_t * sm, snat_session_t * ses,
 729                                 tcp_header_t * tcp, u32 thread_index)
 730 {
 731   if (tcp->flags & TCP_FLAG_FIN)
 732     {
 733       ses->i2o_fin_seq = clib_net_to_host_u32 (tcp->seq_number);
 734       ses->state |= NAT44_SES_I2O_FIN;
 735     }
 736   if ((tcp->flags & TCP_FLAG_ACK) && (ses->state & NAT44_SES_O2I_FIN))
 737     {
 738       if (clib_net_to_host_u32 (tcp->ack_number) > ses->o2i_fin_seq)
 739         ses->state |= NAT44_SES_O2I_FIN_ACK;
 740     }
 741   if (nat44_is_ses_closed (ses))
 742     {
 743       nat_free_session_data (sm, ses, thread_index);
 744       nat44_delete_session (sm, ses, thread_index);
 745       return 1;
 746     }
 747   return 0;
 748 }
 749
 750 always_inline int
 751 nat44_set_tcp_session_state_o2i(snat_main_t * sm, snat_session_t * ses,
 752                                 tcp_header_t * tcp, u32 thread_index)
 753 {
 754   if (tcp->flags & TCP_FLAG_FIN)
 755     {
 756       ses->o2i_fin_seq = clib_net_to_host_u32 (tcp->seq_number);
 757       ses->state |= NAT44_SES_O2I_FIN;
 758     }
 759   if ((tcp->flags & TCP_FLAG_ACK) && (ses->state & NAT44_SES_I2O_FIN))
 760     {
 761       if (clib_net_to_host_u32 (tcp->ack_number) > ses->i2o_fin_seq)
 762         ses->state |= NAT44_SES_I2O_FIN_ACK;
 763     }
 764   if (nat44_is_ses_closed (ses))
 765     {
 766       nat_free_session_data (sm, ses, thread_index);
 767       nat44_delete_session (sm, ses, thread_index);
 768       return 1;
 769     }
 770   return 0;
 771 }
 772
 773 #endif /* __included_snat_h__ */