src/plugins/snat/snat.h

   1
   2 /*
   3  * snat.h - simple nat 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_snat_h__
  19 #define __included_snat_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/dlist.h>
  28 #include <vppinfra/error.h>
  29 #include <vlibapi/api.h>
  30
  31
  32 #define SNAT_UDP_TIMEOUT 300
  33 #define SNAT_UDP_TIMEOUT_MIN 120
  34 #define SNAT_TCP_TRANSITORY_TIMEOUT 240
  35 #define SNAT_TCP_ESTABLISHED_TIMEOUT 7440
  36 #define SNAT_TCP_INCOMING_SYN 6
  37 #define SNAT_ICMP_TIMEOUT 60
  38
  39 /* Key */
  40 typedef struct {
  41   union
  42   {
  43     struct
  44     {
  45       ip4_address_t addr;
  46       u16 port;
  47       u16 protocol:3,
  48         fib_index:13;
  49     };
  50     u64 as_u64;
  51   };
  52 } snat_session_key_t;
  53
  54 typedef struct {
  55   union
  56   {
  57     struct
  58     {
  59       ip4_address_t ext_host_addr;
  60       u16 ext_host_port;
  61       u16 out_port;
  62     };
  63     u64 as_u64;
  64   };
  65 } snat_det_out_key_t;
  66
  67 typedef struct {
  68   union
  69   {
  70     struct
  71     {
  72       ip4_address_t addr;
  73       u32 fib_index;
  74     };
  75     u64 as_u64;
  76   };
  77 } snat_user_key_t;
  78
  79 typedef struct {
  80   union
  81   {
  82     struct
  83     {
  84       ip4_address_t addr;
  85       u16 port;
  86       u16 fib_index;
  87     };
  88     u64 as_u64;
  89   };
  90 } snat_worker_key_t;
  91
  92
  93 #define foreach_snat_protocol \
  94   _(UDP, 0, udp, "udp")       \
  95   _(TCP, 1, tcp, "tcp")       \
  96   _(ICMP, 2, icmp, "icmp")
  97
  98 typedef enum {
  99 #define _(N, i, n, s) SNAT_PROTOCOL_##N = i,
 100   foreach_snat_protocol
 101 #undef _
 102 } snat_protocol_t;
 103
 104
 105 #define foreach_snat_session_state          \
 106   _(0, UNKNOWN, "unknown")                 \
 107   _(1, UDP_ACTIVE, "udp-active")           \
 108   _(2, TCP_SYN_SENT, "tcp-syn-sent")       \
 109   _(3, TCP_ESTABLISHED, "tcp-established") \
 110   _(4, TCP_FIN_WAIT, "tcp-fin-wait")       \
 111   _(5, TCP_CLOSE_WAIT, "tcp-close-wait")   \
 112   _(6, TCP_LAST_ACK, "tcp-last-ack")       \
 113   _(7, ICMP_ACTIVE, "icmp-active")
 114
 115 typedef enum {
 116 #define _(v, N, s) SNAT_SESSION_##N = v,
 117   foreach_snat_session_state
 118 #undef _
 119 } snat_session_state_t;
 120
 121
 122 #define SNAT_SESSION_FLAG_STATIC_MAPPING 1
 123
 124 typedef CLIB_PACKED(struct {
 125   snat_session_key_t out2in;    /* 0-15 */
 126
 127   snat_session_key_t in2out;    /* 16-31 */
 128
 129   u32 flags;                    /* 32-35 */
 130
 131   /* per-user translations */
 132   u32 per_user_index;           /* 36-39 */
 133
 134   u32 per_user_list_head_index; /* 40-43 */
 135
 136   /* Last heard timer */
 137   f64 last_heard;               /* 44-51 */
 138
 139   u64 total_bytes;              /* 52-59 */
 140
 141   u32 total_pkts;               /* 60-63 */
 142
 143   /* Outside address */
 144   u32 outside_address_index;    /* 64-67 */
 145
 146 }) snat_session_t;
 147
 148
 149 typedef struct {
 150   ip4_address_t addr;
 151   u32 fib_index;
 152   u32 sessions_per_user_list_head_index;
 153   u32 nsessions;
 154   u32 nstaticsessions;
 155 } snat_user_t;
 156
 157 typedef struct {
 158   ip4_address_t addr;
 159   u32 fib_index;
 160 #define _(N, i, n, s) \
 161   u32 busy_##n##_ports; \
 162   uword * busy_##n##_port_bitmap;
 163   foreach_snat_protocol
 164 #undef _
 165 } snat_address_t;
 166
 167 typedef struct {
 168   u16 in_port;
 169   snat_det_out_key_t out;
 170   u8 state;
 171   u32 expire;
 172 } snat_det_session_t;
 173
 174 typedef struct {
 175   ip4_address_t in_addr;
 176   u8 in_plen;
 177   ip4_address_t out_addr;
 178   u8 out_plen;
 179   u32 sharing_ratio;
 180   u16 ports_per_host;
 181   u32 ses_num;
 182   /* vector of sessions */
 183   snat_det_session_t * sessions;
 184 } snat_det_map_t;
 185
 186 typedef struct {
 187   ip4_address_t local_addr;
 188   ip4_address_t external_addr;
 189   u16 local_port;
 190   u16 external_port;
 191   u8 addr_only;
 192   u32 vrf_id;
 193   u32 fib_index;
 194   snat_protocol_t proto;
 195 } snat_static_mapping_t;
 196
 197 typedef struct {
 198   u32 sw_if_index;
 199   u8 is_inside;
 200 } snat_interface_t;
 201
 202 typedef struct {
 203   ip4_address_t l_addr;
 204   u16 l_port;
 205   u16 e_port;
 206   u32 sw_if_index;
 207   u32 vrf_id;
 208   snat_protocol_t proto;
 209   int addr_only;
 210   int is_add;
 211 } snat_static_map_resolve_t;
 212
 213 typedef struct {
 214   /* User pool */
 215   snat_user_t * users;
 216
 217   /* Session pool */
 218   snat_session_t * sessions;
 219
 220   /* Pool of doubly-linked list elements */
 221   dlist_elt_t * list_pool;
 222 } snat_main_per_thread_data_t;
 223
 224 struct snat_main_s;
 225
 226 typedef u32 snat_icmp_match_function_t (struct snat_main_s *sm,
 227                                         vlib_node_runtime_t *node,
 228                                         u32 thread_index,
 229                                         vlib_buffer_t *b0,
 230                                         u8 *p_proto,
 231                                         snat_session_key_t *p_value,
 232                                         u8 *p_dont_translate,
 233                                         void *d,
 234                                         void *e);
 235
 236 typedef u32 (snat_get_worker_function_t) (ip4_header_t * ip, u32 rx_fib_index);
 237
 238 typedef struct snat_main_s {
 239   /* Main lookup tables */
 240   clib_bihash_8_8_t out2in;
 241   clib_bihash_8_8_t in2out;
 242
 243   /* Find-a-user => src address lookup */
 244   clib_bihash_8_8_t user_hash;
 245
 246   /* Non-translated packets worker lookup => src address + VRF */
 247   clib_bihash_8_8_t worker_by_in;
 248
 249   /* Translated packets worker lookup => IP address + port number */
 250   clib_bihash_8_8_t worker_by_out;
 251
 252   snat_icmp_match_function_t * icmp_match_in2out_cb;
 253   snat_icmp_match_function_t * icmp_match_out2in_cb;
 254
 255   u32 num_workers;
 256   u32 first_worker_index;
 257   u32 next_worker;
 258   u32 * workers;
 259   snat_get_worker_function_t * worker_in2out_cb;
 260   snat_get_worker_function_t * worker_out2in_cb;
 261
 262   /* Per thread data */
 263   snat_main_per_thread_data_t * per_thread_data;
 264
 265   /* Find a static mapping by local */
 266   clib_bihash_8_8_t static_mapping_by_local;
 267
 268   /* Find a static mapping by external */
 269   clib_bihash_8_8_t static_mapping_by_external;
 270
 271   /* Static mapping pool */
 272   snat_static_mapping_t * static_mappings;
 273
 274   /* Interface pool */
 275   snat_interface_t * interfaces;
 276
 277   /* Vector of outside addresses */
 278   snat_address_t * addresses;
 279
 280   /* sw_if_indices whose intfc addresses should be auto-added */
 281   u32 * auto_add_sw_if_indices;
 282
 283   /* vector of interface address static mappings to resolve. */
 284   snat_static_map_resolve_t *to_resolve;
 285
 286   /* Randomize port allocation order */
 287   u32 random_seed;
 288
 289   /* Worker handoff index */
 290   u32 fq_in2out_index;
 291   u32 fq_out2in_index;
 292
 293   /* in2out and out2in node index */
 294   u32 in2out_node_index;
 295   u32 out2in_node_index;
 296
 297   /* Deterministic NAT */
 298   snat_det_map_t * det_maps;
 299
 300   /* Config parameters */
 301   u8 static_mapping_only;
 302   u8 static_mapping_connection_tracking;
 303   u8 deterministic;
 304   u32 translation_buckets;
 305   u32 translation_memory_size;
 306   u32 user_buckets;
 307   u32 user_memory_size;
 308   u32 max_translations_per_user;
 309   u32 outside_vrf_id;
 310   u32 outside_fib_index;
 311   u32 inside_vrf_id;
 312   u32 inside_fib_index;
 313
 314   /* tenant VRF aware address pool activation flag */
 315   u8 vrf_mode;
 316
 317   /* values of various timeouts */
 318   u32 udp_timeout;
 319   u32 tcp_established_timeout;
 320   u32 tcp_transitory_timeout;
 321   u32 icmp_timeout;
 322
 323   /* API message ID base */
 324   u16 msg_id_base;
 325
 326   /* convenience */
 327   vlib_main_t * vlib_main;
 328   vnet_main_t * vnet_main;
 329   ip4_main_t * ip4_main;
 330   ip_lookup_main_t * ip4_lookup_main;
 331   api_main_t * api_main;
 332 } snat_main_t;
 333
 334 extern snat_main_t snat_main;
 335 extern vlib_node_registration_t snat_in2out_node;
 336 extern vlib_node_registration_t snat_out2in_node;
 337 extern vlib_node_registration_t snat_in2out_fast_node;
 338 extern vlib_node_registration_t snat_out2in_fast_node;
 339 extern vlib_node_registration_t snat_in2out_worker_handoff_node;
 340 extern vlib_node_registration_t snat_out2in_worker_handoff_node;
 341 extern vlib_node_registration_t snat_det_in2out_node;
 342 extern vlib_node_registration_t snat_det_out2in_node;
 343
 344 void snat_free_outside_address_and_port (snat_main_t * sm,
 345                                          snat_session_key_t * k,
 346                                          u32 address_index);
 347
 348 int snat_alloc_outside_address_and_port (snat_main_t * sm,
 349                                          u32 fib_index,
 350                                          snat_session_key_t * k,
 351                                          u32 * address_indexp);
 352
 353 int snat_static_mapping_match (snat_main_t * sm,
 354                                snat_session_key_t match,
 355                                snat_session_key_t * mapping,
 356                                u8 by_external,
 357                                u8 *is_addr_only);
 358
 359 void snat_add_del_addr_to_fib (ip4_address_t * addr,
 360                                u8 p_len,
 361                                u32 sw_if_index,
 362                                int is_add);
 363
 364 format_function_t format_snat_user;
 365
 366 typedef struct {
 367   u32 cached_sw_if_index;
 368   u32 cached_ip4_address;
 369 } snat_runtime_t;
 370
 371 /** \brief Check if SNAT session is created from static mapping.
 372     @param s SNAT session
 373     @return 1 if SNAT session is created from static mapping otherwise 0
 374 */
 375 #define snat_is_session_static(s) s->flags & SNAT_SESSION_FLAG_STATIC_MAPPING
 376
 377 /*
 378  * Why is this here? Because we don't need to touch this layer to
 379  * simply reply to an icmp. We need to change id to a unique
 380  * value to NAT an echo request/reply.
 381  */
 382
 383 typedef struct {
 384   u16 identifier;
 385   u16 sequence;
 386 } icmp_echo_header_t;
 387
 388 always_inline u32
 389 ip_proto_to_snat_proto (u8 ip_proto)
 390 {
 391   u32 snat_proto = ~0;
 392
 393   snat_proto = (ip_proto == IP_PROTOCOL_UDP) ? SNAT_PROTOCOL_UDP : snat_proto;
 394   snat_proto = (ip_proto == IP_PROTOCOL_TCP) ? SNAT_PROTOCOL_TCP : snat_proto;
 395   snat_proto = (ip_proto == IP_PROTOCOL_ICMP) ? SNAT_PROTOCOL_ICMP : snat_proto;
 396   snat_proto = (ip_proto == IP_PROTOCOL_ICMP6) ? SNAT_PROTOCOL_ICMP : snat_proto;
 397
 398   return snat_proto;
 399 }
 400
 401 always_inline u8
 402 snat_proto_to_ip_proto (snat_protocol_t snat_proto)
 403 {
 404   u8 ip_proto = ~0;
 405
 406   ip_proto = (snat_proto == SNAT_PROTOCOL_UDP) ? IP_PROTOCOL_UDP : ip_proto;
 407   ip_proto = (snat_proto == SNAT_PROTOCOL_TCP) ? IP_PROTOCOL_TCP : ip_proto;
 408   ip_proto = (snat_proto == SNAT_PROTOCOL_ICMP) ? IP_PROTOCOL_ICMP : ip_proto;
 409
 410   return ip_proto;
 411 }
 412
 413 typedef struct {
 414   u16 src_port, dst_port;
 415 } tcp_udp_header_t;
 416
 417 u32 icmp_match_in2out_fast(snat_main_t *sm, vlib_node_runtime_t *node,
 418                            u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
 419                            snat_session_key_t *p_value,
 420                            u8 *p_dont_translate, void *d, void *e);
 421 u32 icmp_match_in2out_slow(snat_main_t *sm, vlib_node_runtime_t *node,
 422                            u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
 423                            snat_session_key_t *p_value,
 424                            u8 *p_dont_translate, void *d, void *e);
 425 u32 icmp_match_in2out_det(snat_main_t *sm, vlib_node_runtime_t *node,
 426                           u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
 427                           snat_session_key_t *p_value,
 428                           u8 *p_dont_translate, void *d, void *e);
 429 u32 icmp_match_out2in_fast(snat_main_t *sm, vlib_node_runtime_t *node,
 430                            u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
 431                            snat_session_key_t *p_value,
 432                            u8 *p_dont_translate, void *d, void *e);
 433 u32 icmp_match_out2in_slow(snat_main_t *sm, vlib_node_runtime_t *node,
 434                            u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
 435                            snat_session_key_t *p_value,
 436                            u8 *p_dont_translate, void *d, void *e);
 437 u32 icmp_match_out2in_det(snat_main_t *sm, vlib_node_runtime_t *node,
 438                           u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
 439                           snat_session_key_t *p_value,
 440                           u8 *p_dont_translate, void *d, void *e);
 441 void increment_v4_address(ip4_address_t * a);
 442 void snat_add_address(snat_main_t *sm, ip4_address_t *addr, u32 vrf_id);
 443 int snat_del_address(snat_main_t *sm, ip4_address_t addr, u8 delete_sm);
 444 int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
 445                             u16 l_port, u16 e_port, u32 vrf_id, int addr_only,
 446                             u32 sw_if_index, snat_protocol_t proto, int is_add);
 447 clib_error_t * snat_api_init(vlib_main_t * vm, snat_main_t * sm);
 448 int snat_set_workers (uword * bitmap);
 449 int snat_interface_add_del(u32 sw_if_index, u8 is_inside, int is_del);
 450 int snat_add_interface_address(snat_main_t *sm, u32 sw_if_index, int is_del);
 451 uword unformat_snat_protocol(unformat_input_t * input, va_list * args);
 452 u8 * format_snat_protocol(u8 * s, va_list * args);
 453
 454 static_always_inline u8
 455 icmp_is_error_message (icmp46_header_t * icmp)
 456 {
 457   switch(icmp->type)
 458     {
 459     case ICMP4_destination_unreachable:
 460     case ICMP4_time_exceeded:
 461     case ICMP4_parameter_problem:
 462     case ICMP4_source_quench:
 463     case ICMP4_redirect:
 464     case ICMP4_alternate_host_address:
 465       return 1;
 466     }
 467   return 0;
 468 }
 469
 470 static_always_inline u8
 471 is_interface_addr(snat_main_t *sm, vlib_node_runtime_t *node, u32 sw_if_index0,
 472                   u32 ip4_addr)
 473 {
 474   snat_runtime_t *rt = (snat_runtime_t *) node->runtime_data;
 475   ip4_address_t * first_int_addr;
 476
 477   if (PREDICT_FALSE(rt->cached_sw_if_index != sw_if_index0))
 478     {
 479       first_int_addr =
 480         ip4_interface_first_address (sm->ip4_main, sw_if_index0,
 481                                      0 /* just want the address */);
 482       rt->cached_sw_if_index = sw_if_index0;
 483       if (first_int_addr)
 484         rt->cached_ip4_address = first_int_addr->as_u32;
 485       else
 486         rt->cached_ip4_address = 0;
 487     }
 488
 489   if (PREDICT_FALSE(ip4_addr == rt->cached_ip4_address))
 490     return 1;
 491   else
 492     return 0;
 493 }
 494
 495 #endif /* __included_snat_h__ */