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