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 fib_index;
  65       u16 l_port;
  66       u8 proto;
  67       u8 rsvd;
  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 typedef struct {
  99   union
 100   {
 101     struct
 102     {
 103       ip4_address_t addr;
 104       u16 port;
 105       u16 fib_index;
 106     };
 107     u64 as_u64;
 108   };
 109 } snat_worker_key_t;
 110
 111
 112 #define foreach_snat_protocol \
 113   _(UDP, 0, udp, "udp")       \
 114   _(TCP, 1, tcp, "tcp")       \
 115   _(ICMP, 2, icmp, "icmp")
 116
 117 typedef enum {
 118 #define _(N, i, n, s) SNAT_PROTOCOL_##N = i,
 119   foreach_snat_protocol
 120 #undef _
 121 } snat_protocol_t;
 122
 123
 124 #define foreach_snat_session_state          \
 125   _(0, UNKNOWN, "unknown")                 \
 126   _(1, UDP_ACTIVE, "udp-active")           \
 127   _(2, TCP_SYN_SENT, "tcp-syn-sent")       \
 128   _(3, TCP_ESTABLISHED, "tcp-established") \
 129   _(4, TCP_FIN_WAIT, "tcp-fin-wait")       \
 130   _(5, TCP_CLOSE_WAIT, "tcp-close-wait")   \
 131   _(6, TCP_LAST_ACK, "tcp-last-ack")       \
 132   _(7, ICMP_ACTIVE, "icmp-active")
 133
 134 typedef enum {
 135 #define _(v, N, s) SNAT_SESSION_##N = v,
 136   foreach_snat_session_state
 137 #undef _
 138 } snat_session_state_t;
 139
 140
 141 #define SNAT_SESSION_FLAG_STATIC_MAPPING 1
 142 #define SNAT_SESSION_FLAG_UNKNOWN_PROTO  2
 143 #define SNAT_SESSION_FLAG_LOAD_BALANCING 4
 144
 145 typedef CLIB_PACKED(struct {
 146   snat_session_key_t out2in;    /* 0-15 */
 147
 148   snat_session_key_t in2out;    /* 16-31 */
 149
 150   u32 flags;                    /* 32-35 */
 151
 152   /* per-user translations */
 153   u32 per_user_index;           /* 36-39 */
 154
 155   u32 per_user_list_head_index; /* 40-43 */
 156
 157   /* Last heard timer */
 158   f64 last_heard;               /* 44-51 */
 159
 160   u64 total_bytes;              /* 52-59 */
 161
 162   u32 total_pkts;               /* 60-63 */
 163
 164   /* Outside address */
 165   u32 outside_address_index;    /* 64-67 */
 166
 167   /* External host address */
 168   ip4_address_t ext_host_addr;  /* 68-71 */
 169
 170 }) snat_session_t;
 171
 172
 173 typedef struct {
 174   ip4_address_t addr;
 175   u32 fib_index;
 176   u32 sessions_per_user_list_head_index;
 177   u32 nsessions;
 178   u32 nstaticsessions;
 179 } snat_user_t;
 180
 181 typedef struct {
 182   ip4_address_t addr;
 183   u32 fib_index;
 184 #define _(N, i, n, s) \
 185   u16 busy_##n##_ports; \
 186   u16 * busy_##n##_ports_per_thread; \
 187   uword * busy_##n##_port_bitmap;
 188   foreach_snat_protocol
 189 #undef _
 190 } snat_address_t;
 191
 192 typedef struct {
 193   u16 in_port;
 194   snat_det_out_key_t out;
 195   u8 state;
 196   u32 expire;
 197 } snat_det_session_t;
 198
 199 typedef struct {
 200   ip4_address_t in_addr;
 201   u8 in_plen;
 202   ip4_address_t out_addr;
 203   u8 out_plen;
 204   u32 sharing_ratio;
 205   u16 ports_per_host;
 206   u32 ses_num;
 207   /* vector of sessions */
 208   snat_det_session_t * sessions;
 209 } snat_det_map_t;
 210
 211 typedef struct {
 212   ip4_address_t addr;
 213   u16 port;
 214   u8 probability;
 215   u8 prefix;
 216 } nat44_lb_addr_port_t;
 217
 218 typedef struct {
 219   ip4_address_t local_addr;
 220   ip4_address_t external_addr;
 221   u16 local_port;
 222   u16 external_port;
 223   u8 addr_only;
 224   u32 vrf_id;
 225   u32 fib_index;
 226   snat_protocol_t proto;
 227   u32 worker_index;
 228   nat44_lb_addr_port_t *locals;
 229 } snat_static_mapping_t;
 230
 231 typedef struct {
 232   u32 sw_if_index;
 233   u8 is_inside;
 234 } snat_interface_t;
 235
 236 typedef struct {
 237   ip4_address_t l_addr;
 238   u16 l_port;
 239   u16 e_port;
 240   u32 sw_if_index;
 241   u32 vrf_id;
 242   snat_protocol_t proto;
 243   int addr_only;
 244   int is_add;
 245 } snat_static_map_resolve_t;
 246
 247 typedef struct {
 248   /* Main lookup tables */
 249   clib_bihash_8_8_t out2in;
 250   clib_bihash_8_8_t in2out;
 251
 252   /* Find-a-user => src address lookup */
 253   clib_bihash_8_8_t user_hash;
 254
 255   /* User pool */
 256   snat_user_t * users;
 257
 258   /* Session pool */
 259   snat_session_t * sessions;
 260
 261   /* Pool of doubly-linked list elements */
 262   dlist_elt_t * list_pool;
 263
 264   u32 snat_thread_index;
 265 } snat_main_per_thread_data_t;
 266
 267 struct snat_main_s;
 268
 269 typedef u32 snat_icmp_match_function_t (struct snat_main_s *sm,
 270                                         vlib_node_runtime_t *node,
 271                                         u32 thread_index,
 272                                         vlib_buffer_t *b0,
 273                                         u8 *p_proto,
 274                                         snat_session_key_t *p_value,
 275                                         u8 *p_dont_translate,
 276                                         void *d,
 277                                         void *e);
 278
 279 typedef u32 (snat_get_worker_function_t) (ip4_header_t * ip, u32 rx_fib_index);
 280
 281 typedef struct snat_main_s {
 282   /* Endpoint address dependent sessions lookup tables */
 283   clib_bihash_16_8_t out2in_ed;
 284   clib_bihash_16_8_t in2out_ed;
 285
 286   /* Non-translated packets worker lookup => src address + VRF */
 287   clib_bihash_8_8_t worker_by_in;
 288
 289   snat_icmp_match_function_t * icmp_match_in2out_cb;
 290   snat_icmp_match_function_t * icmp_match_out2in_cb;
 291
 292   u32 num_workers;
 293   u32 first_worker_index;
 294   u32 next_worker;
 295   u32 * workers;
 296   snat_get_worker_function_t * worker_in2out_cb;
 297   snat_get_worker_function_t * worker_out2in_cb;
 298   u16 port_per_thread;
 299   u32 num_snat_thread;
 300
 301   /* Per thread data */
 302   snat_main_per_thread_data_t * per_thread_data;
 303
 304   /* Find a static mapping by local */
 305   clib_bihash_8_8_t static_mapping_by_local;
 306
 307   /* Find a static mapping by external */
 308   clib_bihash_8_8_t static_mapping_by_external;
 309
 310   /* Static mapping pool */
 311   snat_static_mapping_t * static_mappings;
 312
 313   /* Interface pool */
 314   snat_interface_t * interfaces;
 315   snat_interface_t * output_feature_interfaces;
 316
 317   /* Vector of outside addresses */
 318   snat_address_t * addresses;
 319
 320   /* sw_if_indices whose intfc addresses should be auto-added */
 321   u32 * auto_add_sw_if_indices;
 322
 323   /* vector of interface address static mappings to resolve. */
 324   snat_static_map_resolve_t *to_resolve;
 325
 326   /* Randomize port allocation order */
 327   u32 random_seed;
 328
 329   /* Worker handoff index */
 330   u32 fq_in2out_index;
 331   u32 fq_in2out_output_index;
 332   u32 fq_out2in_index;
 333
 334   /* in2out and out2in node index */
 335   u32 in2out_node_index;
 336   u32 in2out_output_node_index;
 337   u32 out2in_node_index;
 338
 339   /* Deterministic NAT */
 340   snat_det_map_t * det_maps;
 341
 342   /* Config parameters */
 343   u8 static_mapping_only;
 344   u8 static_mapping_connection_tracking;
 345   u8 deterministic;
 346   u32 translation_buckets;
 347   u32 translation_memory_size;
 348   u32 max_translations;
 349   u32 user_buckets;
 350   u32 user_memory_size;
 351   u32 max_translations_per_user;
 352   u32 outside_vrf_id;
 353   u32 outside_fib_index;
 354   u32 inside_vrf_id;
 355   u32 inside_fib_index;
 356
 357   /* tenant VRF aware address pool activation flag */
 358   u8 vrf_mode;
 359
 360   /* values of various timeouts */
 361   u32 udp_timeout;
 362   u32 tcp_established_timeout;
 363   u32 tcp_transitory_timeout;
 364   u32 icmp_timeout;
 365
 366   /* API message ID base */
 367   u16 msg_id_base;
 368
 369   /* convenience */
 370   vlib_main_t * vlib_main;
 371   vnet_main_t * vnet_main;
 372   ip4_main_t * ip4_main;
 373   ip_lookup_main_t * ip4_lookup_main;
 374   api_main_t * api_main;
 375 } snat_main_t;
 376
 377 extern snat_main_t snat_main;
 378 extern vlib_node_registration_t snat_in2out_node;
 379 extern vlib_node_registration_t snat_in2out_output_node;
 380 extern vlib_node_registration_t snat_out2in_node;
 381 extern vlib_node_registration_t snat_in2out_fast_node;
 382 extern vlib_node_registration_t snat_out2in_fast_node;
 383 extern vlib_node_registration_t snat_in2out_worker_handoff_node;
 384 extern vlib_node_registration_t snat_in2out_output_worker_handoff_node;
 385 extern vlib_node_registration_t snat_out2in_worker_handoff_node;
 386 extern vlib_node_registration_t snat_det_in2out_node;
 387 extern vlib_node_registration_t snat_det_out2in_node;
 388 extern vlib_node_registration_t snat_hairpin_dst_node;
 389 extern vlib_node_registration_t snat_hairpin_src_node;
 390
 391 void snat_free_outside_address_and_port (snat_main_t * sm,
 392                                          u32 thread_index,
 393                                          snat_session_key_t * k,
 394                                          u32 address_index);
 395
 396 int snat_alloc_outside_address_and_port (snat_main_t * sm,
 397                                          u32 fib_index,
 398                                          u32 thread_index,
 399                                          snat_session_key_t * k,
 400                                          u32 * address_indexp);
 401
 402 int snat_static_mapping_match (snat_main_t * sm,
 403                                snat_session_key_t match,
 404                                snat_session_key_t * mapping,
 405                                u8 by_external,
 406                                u8 *is_addr_only);
 407
 408 void snat_add_del_addr_to_fib (ip4_address_t * addr,
 409                                u8 p_len,
 410                                u32 sw_if_index,
 411                                int is_add);
 412
 413 format_function_t format_snat_user;
 414
 415 typedef struct {
 416   u32 cached_sw_if_index;
 417   u32 cached_ip4_address;
 418 } snat_runtime_t;
 419
 420 /** \brief Check if SNAT session is created from static mapping.
 421     @param s SNAT session
 422     @return 1 if SNAT session is created from static mapping otherwise 0
 423 */
 424 #define snat_is_session_static(s) s->flags & SNAT_SESSION_FLAG_STATIC_MAPPING
 425
 426 /** \brief Check if SNAT session for unknown protocol.
 427     @param s SNAT session
 428     @return 1 if SNAT session for unknown protocol otherwise 0
 429 */
 430 #define snat_is_unk_proto_session(s) s->flags & SNAT_SESSION_FLAG_UNKNOWN_PROTO
 431
 432 /*
 433  * Why is this here? Because we don't need to touch this layer to
 434  * simply reply to an icmp. We need to change id to a unique
 435  * value to NAT an echo request/reply.
 436  */
 437
 438 typedef struct {
 439   u16 identifier;
 440   u16 sequence;
 441 } icmp_echo_header_t;
 442
 443 always_inline u32
 444 ip_proto_to_snat_proto (u8 ip_proto)
 445 {
 446   u32 snat_proto = ~0;
 447
 448   snat_proto = (ip_proto == IP_PROTOCOL_UDP) ? SNAT_PROTOCOL_UDP : snat_proto;
 449   snat_proto = (ip_proto == IP_PROTOCOL_TCP) ? SNAT_PROTOCOL_TCP : snat_proto;
 450   snat_proto = (ip_proto == IP_PROTOCOL_ICMP) ? SNAT_PROTOCOL_ICMP : snat_proto;
 451   snat_proto = (ip_proto == IP_PROTOCOL_ICMP6) ? SNAT_PROTOCOL_ICMP : snat_proto;
 452
 453   return snat_proto;
 454 }
 455
 456 always_inline u8
 457 snat_proto_to_ip_proto (snat_protocol_t snat_proto)
 458 {
 459   u8 ip_proto = ~0;
 460
 461   ip_proto = (snat_proto == SNAT_PROTOCOL_UDP) ? IP_PROTOCOL_UDP : ip_proto;
 462   ip_proto = (snat_proto == SNAT_PROTOCOL_TCP) ? IP_PROTOCOL_TCP : ip_proto;
 463   ip_proto = (snat_proto == SNAT_PROTOCOL_ICMP) ? IP_PROTOCOL_ICMP : ip_proto;
 464
 465   return ip_proto;
 466 }
 467
 468 typedef struct {
 469   u16 src_port, dst_port;
 470 } tcp_udp_header_t;
 471
 472 u32 icmp_match_in2out_fast(snat_main_t *sm, vlib_node_runtime_t *node,
 473                            u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
 474                            snat_session_key_t *p_value,
 475                            u8 *p_dont_translate, void *d, void *e);
 476 u32 icmp_match_in2out_slow(snat_main_t *sm, vlib_node_runtime_t *node,
 477                            u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
 478                            snat_session_key_t *p_value,
 479                            u8 *p_dont_translate, void *d, void *e);
 480 u32 icmp_match_in2out_det(snat_main_t *sm, vlib_node_runtime_t *node,
 481                           u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
 482                           snat_session_key_t *p_value,
 483                           u8 *p_dont_translate, void *d, void *e);
 484 u32 icmp_match_out2in_fast(snat_main_t *sm, vlib_node_runtime_t *node,
 485                            u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
 486                            snat_session_key_t *p_value,
 487                            u8 *p_dont_translate, void *d, void *e);
 488 u32 icmp_match_out2in_slow(snat_main_t *sm, vlib_node_runtime_t *node,
 489                            u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
 490                            snat_session_key_t *p_value,
 491                            u8 *p_dont_translate, void *d, void *e);
 492 u32 icmp_match_out2in_det(snat_main_t *sm, vlib_node_runtime_t *node,
 493                           u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
 494                           snat_session_key_t *p_value,
 495                           u8 *p_dont_translate, void *d, void *e);
 496 void increment_v4_address(ip4_address_t * a);
 497 void snat_add_address(snat_main_t *sm, ip4_address_t *addr, u32 vrf_id);
 498 int snat_del_address(snat_main_t *sm, ip4_address_t addr, u8 delete_sm);
 499 int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
 500                             u16 l_port, u16 e_port, u32 vrf_id, int addr_only,
 501                             u32 sw_if_index, snat_protocol_t proto, int is_add);
 502 clib_error_t * snat_api_init(vlib_main_t * vm, snat_main_t * sm);
 503 int snat_set_workers (uword * bitmap);
 504 int snat_interface_add_del(u32 sw_if_index, u8 is_inside, int is_del);
 505 int snat_interface_add_del_output_feature(u32 sw_if_index, u8 is_inside,
 506                                           int is_del);
 507 int snat_add_interface_address(snat_main_t *sm, u32 sw_if_index, int is_del);
 508 uword unformat_snat_protocol(unformat_input_t * input, va_list * args);
 509 u8 * format_snat_protocol(u8 * s, va_list * args);
 510 int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
 511                                      snat_protocol_t proto, u32 vrf_id,
 512                                      nat44_lb_addr_port_t *locals, u8 is_add);
 513
 514 static_always_inline u8
 515 icmp_is_error_message (icmp46_header_t * icmp)
 516 {
 517   switch(icmp->type)
 518     {
 519     case ICMP4_destination_unreachable:
 520     case ICMP4_time_exceeded:
 521     case ICMP4_parameter_problem:
 522     case ICMP4_source_quench:
 523     case ICMP4_redirect:
 524     case ICMP4_alternate_host_address:
 525       return 1;
 526     }
 527   return 0;
 528 }
 529
 530 static_always_inline u8
 531 is_interface_addr(snat_main_t *sm, vlib_node_runtime_t *node, u32 sw_if_index0,
 532                   u32 ip4_addr)
 533 {
 534   snat_runtime_t *rt = (snat_runtime_t *) node->runtime_data;
 535   ip4_address_t * first_int_addr;
 536
 537   if (PREDICT_FALSE(rt->cached_sw_if_index != sw_if_index0))
 538     {
 539       first_int_addr =
 540         ip4_interface_first_address (sm->ip4_main, sw_if_index0,
 541                                      0 /* just want the address */);
 542       rt->cached_sw_if_index = sw_if_index0;
 543       if (first_int_addr)
 544         rt->cached_ip4_address = first_int_addr->as_u32;
 545       else
 546         rt->cached_ip4_address = 0;
 547     }
 548
 549   if (PREDICT_FALSE(ip4_addr == rt->cached_ip4_address))
 550     return 1;
 551   else
 552     return 0;
 553 }
 554
 555 always_inline u8
 556 maximum_sessions_exceeded (snat_main_t *sm, u32 thread_index)
 557 {
 558   if (pool_elts (sm->per_thread_data[thread_index].sessions) >= sm->max_translations)
 559     return 1;
 560
 561   return 0;
 562 }
 563
 564 #endif /* __included_nat_h__ */