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
  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
 132 typedef CLIB_PACKED(struct {
 133   snat_session_key_t out2in;    /* 0-15 */
 134
 135   snat_session_key_t in2out;    /* 16-31 */
 136
 137   u32 flags;                    /* 32-35 */
 138
 139   /* per-user translations */
 140   u32 per_user_index;           /* 36-39 */
 141
 142   u32 per_user_list_head_index; /* 40-43 */
 143
 144   /* Last heard timer */
 145   f64 last_heard;               /* 44-51 */
 146
 147   u64 total_bytes;              /* 52-59 */
 148
 149   u32 total_pkts;               /* 60-63 */
 150
 151   /* Outside address */
 152   u32 outside_address_index;    /* 64-67 */
 153
 154   /* External host address */
 155   ip4_address_t ext_host_addr;  /* 68-71 */
 156
 157 }) snat_session_t;
 158
 159
 160 typedef struct {
 161   ip4_address_t addr;
 162   u32 fib_index;
 163   u32 sessions_per_user_list_head_index;
 164   u32 nsessions;
 165   u32 nstaticsessions;
 166 } snat_user_t;
 167
 168 typedef struct {
 169   ip4_address_t addr;
 170   u32 fib_index;
 171 #define _(N, i, n, s) \
 172   u16 busy_##n##_ports; \
 173   u16 * busy_##n##_ports_per_thread; \
 174   uword * busy_##n##_port_bitmap;
 175   foreach_snat_protocol
 176 #undef _
 177 } snat_address_t;
 178
 179 typedef struct {
 180   u16 in_port;
 181   snat_det_out_key_t out;
 182   u8 state;
 183   u32 expire;
 184 } snat_det_session_t;
 185
 186 typedef struct {
 187   ip4_address_t in_addr;
 188   u8 in_plen;
 189   ip4_address_t out_addr;
 190   u8 out_plen;
 191   u32 sharing_ratio;
 192   u16 ports_per_host;
 193   u32 ses_num;
 194   /* vector of sessions */
 195   snat_det_session_t * sessions;
 196 } snat_det_map_t;
 197
 198 typedef struct {
 199   ip4_address_t addr;
 200   u16 port;
 201   u8 probability;
 202   u8 prefix;
 203 } nat44_lb_addr_port_t;
 204
 205 typedef struct {
 206   ip4_address_t local_addr;
 207   ip4_address_t external_addr;
 208   u16 local_port;
 209   u16 external_port;
 210   u8 addr_only;
 211   u32 vrf_id;
 212   u32 fib_index;
 213   snat_protocol_t proto;
 214   u32 worker_index;
 215   nat44_lb_addr_port_t *locals;
 216 } snat_static_mapping_t;
 217
 218 typedef struct {
 219   u32 sw_if_index;
 220   u8 is_inside;
 221 } snat_interface_t;
 222
 223 typedef struct {
 224   ip4_address_t l_addr;
 225   u16 l_port;
 226   u16 e_port;
 227   u32 sw_if_index;
 228   u32 vrf_id;
 229   snat_protocol_t proto;
 230   int addr_only;
 231   int is_add;
 232 } snat_static_map_resolve_t;
 233
 234 typedef struct {
 235   /* Main lookup tables */
 236   clib_bihash_8_8_t out2in;
 237   clib_bihash_8_8_t in2out;
 238
 239   /* Find-a-user => src address lookup */
 240   clib_bihash_8_8_t user_hash;
 241
 242   /* User pool */
 243   snat_user_t * users;
 244
 245   /* Session pool */
 246   snat_session_t * sessions;
 247
 248   /* Pool of doubly-linked list elements */
 249   dlist_elt_t * list_pool;
 250
 251   u32 snat_thread_index;
 252 } snat_main_per_thread_data_t;
 253
 254 struct snat_main_s;
 255
 256 typedef u32 snat_icmp_match_function_t (struct snat_main_s *sm,
 257                                         vlib_node_runtime_t *node,
 258                                         u32 thread_index,
 259                                         vlib_buffer_t *b0,
 260                                         u8 *p_proto,
 261                                         snat_session_key_t *p_value,
 262                                         u8 *p_dont_translate,
 263                                         void *d,
 264                                         void *e);
 265
 266 typedef u32 (snat_get_worker_function_t) (ip4_header_t * ip, u32 rx_fib_index);
 267
 268 typedef struct snat_main_s {
 269   /* Endpoint address dependent sessions lookup tables */
 270   clib_bihash_16_8_t out2in_ed;
 271   clib_bihash_16_8_t in2out_ed;
 272
 273   snat_icmp_match_function_t * icmp_match_in2out_cb;
 274   snat_icmp_match_function_t * icmp_match_out2in_cb;
 275
 276   u32 num_workers;
 277   u32 first_worker_index;
 278   u32 next_worker;
 279   u32 * workers;
 280   snat_get_worker_function_t * worker_in2out_cb;
 281   snat_get_worker_function_t * worker_out2in_cb;
 282   u16 port_per_thread;
 283   u32 num_snat_thread;
 284
 285   /* Per thread data */
 286   snat_main_per_thread_data_t * per_thread_data;
 287
 288   /* Find a static mapping by local */
 289   clib_bihash_8_8_t static_mapping_by_local;
 290
 291   /* Find a static mapping by external */
 292   clib_bihash_8_8_t static_mapping_by_external;
 293
 294   /* Static mapping pool */
 295   snat_static_mapping_t * static_mappings;
 296
 297   /* Interface pool */
 298   snat_interface_t * interfaces;
 299   snat_interface_t * output_feature_interfaces;
 300
 301   /* Vector of outside addresses */
 302   snat_address_t * addresses;
 303
 304   /* sw_if_indices whose intfc addresses should be auto-added */
 305   u32 * auto_add_sw_if_indices;
 306
 307   /* vector of interface address static mappings to resolve. */
 308   snat_static_map_resolve_t *to_resolve;
 309
 310   /* Randomize port allocation order */
 311   u32 random_seed;
 312
 313   /* Worker handoff index */
 314   u32 fq_in2out_index;
 315   u32 fq_in2out_output_index;
 316   u32 fq_out2in_index;
 317
 318   /* in2out and out2in node index */
 319   u32 in2out_node_index;
 320   u32 in2out_output_node_index;
 321   u32 out2in_node_index;
 322
 323   /* Deterministic NAT */
 324   snat_det_map_t * det_maps;
 325
 326   /* Config parameters */
 327   u8 static_mapping_only;
 328   u8 static_mapping_connection_tracking;
 329   u8 deterministic;
 330   u32 translation_buckets;
 331   u32 translation_memory_size;
 332   u32 max_translations;
 333   u32 user_buckets;
 334   u32 user_memory_size;
 335   u32 max_translations_per_user;
 336   u32 outside_vrf_id;
 337   u32 outside_fib_index;
 338   u32 inside_vrf_id;
 339   u32 inside_fib_index;
 340
 341   /* tenant VRF aware address pool activation flag */
 342   u8 vrf_mode;
 343
 344   /* values of various timeouts */
 345   u32 udp_timeout;
 346   u32 tcp_established_timeout;
 347   u32 tcp_transitory_timeout;
 348   u32 icmp_timeout;
 349
 350   /* API message ID base */
 351   u16 msg_id_base;
 352
 353   /* convenience */
 354   vlib_main_t * vlib_main;
 355   vnet_main_t * vnet_main;
 356   ip4_main_t * ip4_main;
 357   ip_lookup_main_t * ip4_lookup_main;
 358   api_main_t * api_main;
 359 } snat_main_t;
 360
 361 extern snat_main_t snat_main;
 362 extern vlib_node_registration_t snat_in2out_node;
 363 extern vlib_node_registration_t snat_in2out_output_node;
 364 extern vlib_node_registration_t snat_out2in_node;
 365 extern vlib_node_registration_t snat_in2out_fast_node;
 366 extern vlib_node_registration_t snat_out2in_fast_node;
 367 extern vlib_node_registration_t snat_in2out_worker_handoff_node;
 368 extern vlib_node_registration_t snat_in2out_output_worker_handoff_node;
 369 extern vlib_node_registration_t snat_out2in_worker_handoff_node;
 370 extern vlib_node_registration_t snat_det_in2out_node;
 371 extern vlib_node_registration_t snat_det_out2in_node;
 372 extern vlib_node_registration_t snat_hairpin_dst_node;
 373 extern vlib_node_registration_t snat_hairpin_src_node;
 374
 375 void snat_free_outside_address_and_port (snat_main_t * sm,
 376                                          u32 thread_index,
 377                                          snat_session_key_t * k,
 378                                          u32 address_index);
 379
 380 int snat_alloc_outside_address_and_port (snat_main_t * sm,
 381                                          u32 fib_index,
 382                                          u32 thread_index,
 383                                          snat_session_key_t * k,
 384                                          u32 * address_indexp);
 385
 386 int snat_static_mapping_match (snat_main_t * sm,
 387                                snat_session_key_t match,
 388                                snat_session_key_t * mapping,
 389                                u8 by_external,
 390                                u8 *is_addr_only);
 391
 392 void snat_add_del_addr_to_fib (ip4_address_t * addr,
 393                                u8 p_len,
 394                                u32 sw_if_index,
 395                                int is_add);
 396
 397 format_function_t format_snat_user;
 398
 399 typedef struct {
 400   u32 cached_sw_if_index;
 401   u32 cached_ip4_address;
 402 } snat_runtime_t;
 403
 404 /** \brief Check if SNAT session is created from static mapping.
 405     @param s SNAT session
 406     @return 1 if SNAT session is created from static mapping otherwise 0
 407 */
 408 #define snat_is_session_static(s) s->flags & SNAT_SESSION_FLAG_STATIC_MAPPING
 409
 410 /** \brief Check if SNAT session for unknown protocol.
 411     @param s SNAT session
 412     @return 1 if SNAT session for unknown protocol otherwise 0
 413 */
 414 #define snat_is_unk_proto_session(s) s->flags & SNAT_SESSION_FLAG_UNKNOWN_PROTO
 415
 416 /*
 417  * Why is this here? Because we don't need to touch this layer to
 418  * simply reply to an icmp. We need to change id to a unique
 419  * value to NAT an echo request/reply.
 420  */
 421
 422 typedef struct {
 423   u16 identifier;
 424   u16 sequence;
 425 } icmp_echo_header_t;
 426
 427 always_inline u32
 428 ip_proto_to_snat_proto (u8 ip_proto)
 429 {
 430   u32 snat_proto = ~0;
 431
 432   snat_proto = (ip_proto == IP_PROTOCOL_UDP) ? SNAT_PROTOCOL_UDP : snat_proto;
 433   snat_proto = (ip_proto == IP_PROTOCOL_TCP) ? SNAT_PROTOCOL_TCP : snat_proto;
 434   snat_proto = (ip_proto == IP_PROTOCOL_ICMP) ? SNAT_PROTOCOL_ICMP : snat_proto;
 435   snat_proto = (ip_proto == IP_PROTOCOL_ICMP6) ? SNAT_PROTOCOL_ICMP : snat_proto;
 436
 437   return snat_proto;
 438 }
 439
 440 always_inline u8
 441 snat_proto_to_ip_proto (snat_protocol_t snat_proto)
 442 {
 443   u8 ip_proto = ~0;
 444
 445   ip_proto = (snat_proto == SNAT_PROTOCOL_UDP) ? IP_PROTOCOL_UDP : ip_proto;
 446   ip_proto = (snat_proto == SNAT_PROTOCOL_TCP) ? IP_PROTOCOL_TCP : ip_proto;
 447   ip_proto = (snat_proto == SNAT_PROTOCOL_ICMP) ? IP_PROTOCOL_ICMP : ip_proto;
 448
 449   return ip_proto;
 450 }
 451
 452 typedef struct {
 453   u16 src_port, dst_port;
 454 } tcp_udp_header_t;
 455
 456 u32 icmp_match_in2out_fast(snat_main_t *sm, vlib_node_runtime_t *node,
 457                            u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
 458                            snat_session_key_t *p_value,
 459                            u8 *p_dont_translate, void *d, void *e);
 460 u32 icmp_match_in2out_slow(snat_main_t *sm, vlib_node_runtime_t *node,
 461                            u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
 462                            snat_session_key_t *p_value,
 463                            u8 *p_dont_translate, void *d, void *e);
 464 u32 icmp_match_in2out_det(snat_main_t *sm, vlib_node_runtime_t *node,
 465                           u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
 466                           snat_session_key_t *p_value,
 467                           u8 *p_dont_translate, void *d, void *e);
 468 u32 icmp_match_out2in_fast(snat_main_t *sm, vlib_node_runtime_t *node,
 469                            u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
 470                            snat_session_key_t *p_value,
 471                            u8 *p_dont_translate, void *d, void *e);
 472 u32 icmp_match_out2in_slow(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_out2in_det(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 void increment_v4_address(ip4_address_t * a);
 481 void snat_add_address(snat_main_t *sm, ip4_address_t *addr, u32 vrf_id);
 482 int snat_del_address(snat_main_t *sm, ip4_address_t addr, u8 delete_sm);
 483 int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
 484                             u16 l_port, u16 e_port, u32 vrf_id, int addr_only,
 485                             u32 sw_if_index, snat_protocol_t proto, int is_add);
 486 clib_error_t * snat_api_init(vlib_main_t * vm, snat_main_t * sm);
 487 int snat_set_workers (uword * bitmap);
 488 int snat_interface_add_del(u32 sw_if_index, u8 is_inside, int is_del);
 489 int snat_interface_add_del_output_feature(u32 sw_if_index, u8 is_inside,
 490                                           int is_del);
 491 int snat_add_interface_address(snat_main_t *sm, u32 sw_if_index, int is_del);
 492 uword unformat_snat_protocol(unformat_input_t * input, va_list * args);
 493 u8 * format_snat_protocol(u8 * s, va_list * args);
 494 int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
 495                                      snat_protocol_t proto, u32 vrf_id,
 496                                      nat44_lb_addr_port_t *locals, u8 is_add);
 497
 498 static_always_inline u8
 499 icmp_is_error_message (icmp46_header_t * icmp)
 500 {
 501   switch(icmp->type)
 502     {
 503     case ICMP4_destination_unreachable:
 504     case ICMP4_time_exceeded:
 505     case ICMP4_parameter_problem:
 506     case ICMP4_source_quench:
 507     case ICMP4_redirect:
 508     case ICMP4_alternate_host_address:
 509       return 1;
 510     }
 511   return 0;
 512 }
 513
 514 static_always_inline u8
 515 is_interface_addr(snat_main_t *sm, vlib_node_runtime_t *node, u32 sw_if_index0,
 516                   u32 ip4_addr)
 517 {
 518   snat_runtime_t *rt = (snat_runtime_t *) node->runtime_data;
 519   ip4_address_t * first_int_addr;
 520
 521   if (PREDICT_FALSE(rt->cached_sw_if_index != sw_if_index0))
 522     {
 523       first_int_addr =
 524         ip4_interface_first_address (sm->ip4_main, sw_if_index0,
 525                                      0 /* just want the address */);
 526       rt->cached_sw_if_index = sw_if_index0;
 527       if (first_int_addr)
 528         rt->cached_ip4_address = first_int_addr->as_u32;
 529       else
 530         rt->cached_ip4_address = 0;
 531     }
 532
 533   if (PREDICT_FALSE(ip4_addr == rt->cached_ip4_address))
 534     return 1;
 535   else
 536     return 0;
 537 }
 538
 539 always_inline u8
 540 maximum_sessions_exceeded (snat_main_t *sm, u32 thread_index)
 541 {
 542   if (pool_elts (sm->per_thread_data[thread_index].sessions) >= sm->max_translations)
 543     return 1;
 544
 545   return 0;
 546 }
 547
 548 #endif /* __included_nat_h__ */