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 #define NAT_INTERFACE_FLAG_IS_INSIDE 1
 133 #define NAT_INTERFACE_FLAG_IS_OUTSIDE 2
 134
 135 typedef CLIB_PACKED(struct {
 136   snat_session_key_t out2in;    /* 0-15 */
 137
 138   snat_session_key_t in2out;    /* 16-31 */
 139
 140   u32 flags;                    /* 32-35 */
 141
 142   /* per-user translations */
 143   u32 per_user_index;           /* 36-39 */
 144
 145   u32 per_user_list_head_index; /* 40-43 */
 146
 147   /* Last heard timer */
 148   f64 last_heard;               /* 44-51 */
 149
 150   u64 total_bytes;              /* 52-59 */
 151
 152   u32 total_pkts;               /* 60-63 */
 153
 154   /* Outside address */
 155   u32 outside_address_index;    /* 64-67 */
 156
 157   /* External host address and port */
 158   ip4_address_t ext_host_addr;  /* 68-71 */
 159   u16 ext_host_port;            /* 72-73 */
 160 }) snat_session_t;
 161
 162
 163 typedef struct {
 164   ip4_address_t addr;
 165   u32 fib_index;
 166   u32 sessions_per_user_list_head_index;
 167   u32 nsessions;
 168   u32 nstaticsessions;
 169 } snat_user_t;
 170
 171 typedef struct {
 172   ip4_address_t addr;
 173   u32 fib_index;
 174 #define _(N, i, n, s) \
 175   u16 busy_##n##_ports; \
 176   u16 * busy_##n##_ports_per_thread; \
 177   uword * busy_##n##_port_bitmap;
 178   foreach_snat_protocol
 179 #undef _
 180 } snat_address_t;
 181
 182 typedef struct {
 183   u16 in_port;
 184   snat_det_out_key_t out;
 185   u8 state;
 186   u32 expire;
 187 } snat_det_session_t;
 188
 189 typedef struct {
 190   ip4_address_t in_addr;
 191   u8 in_plen;
 192   ip4_address_t out_addr;
 193   u8 out_plen;
 194   u32 sharing_ratio;
 195   u16 ports_per_host;
 196   u32 ses_num;
 197   /* vector of sessions */
 198   snat_det_session_t * sessions;
 199 } snat_det_map_t;
 200
 201 typedef struct {
 202   ip4_address_t addr;
 203   u16 port;
 204   u8 probability;
 205   u8 prefix;
 206 } nat44_lb_addr_port_t;
 207
 208 typedef struct {
 209   ip4_address_t local_addr;
 210   ip4_address_t external_addr;
 211   u16 local_port;
 212   u16 external_port;
 213   u8 addr_only;
 214   u32 vrf_id;
 215   u32 fib_index;
 216   snat_protocol_t proto;
 217   u32 worker_index;
 218   nat44_lb_addr_port_t *locals;
 219 } snat_static_mapping_t;
 220
 221 typedef struct {
 222   u32 sw_if_index;
 223   u8 flags;
 224 } snat_interface_t;
 225
 226 typedef struct {
 227   ip4_address_t l_addr;
 228   u16 l_port;
 229   u16 e_port;
 230   u32 sw_if_index;
 231   u32 vrf_id;
 232   snat_protocol_t proto;
 233   int addr_only;
 234   int is_add;
 235 } snat_static_map_resolve_t;
 236
 237 typedef struct {
 238   /* Main lookup tables */
 239   clib_bihash_8_8_t out2in;
 240   clib_bihash_8_8_t in2out;
 241
 242   /* Find-a-user => src address lookup */
 243   clib_bihash_8_8_t user_hash;
 244
 245   /* User pool */
 246   snat_user_t * users;
 247
 248   /* Session pool */
 249   snat_session_t * sessions;
 250
 251   /* Pool of doubly-linked list elements */
 252   dlist_elt_t * list_pool;
 253
 254   u32 snat_thread_index;
 255 } snat_main_per_thread_data_t;
 256
 257 struct snat_main_s;
 258
 259 typedef u32 snat_icmp_match_function_t (struct snat_main_s *sm,
 260                                         vlib_node_runtime_t *node,
 261                                         u32 thread_index,
 262                                         vlib_buffer_t *b0,
 263                                         ip4_header_t *ip0,
 264                                         u8 *p_proto,
 265                                         snat_session_key_t *p_value,
 266                                         u8 *p_dont_translate,
 267                                         void *d,
 268                                         void *e);
 269
 270 typedef u32 (snat_get_worker_function_t) (ip4_header_t * ip, u32 rx_fib_index);
 271
 272 typedef int nat_alloc_out_addr_and_port_function_t (snat_address_t * addresses,
 273                                                     u32 fib_index,
 274                                                     u32 thread_index,
 275                                                     snat_session_key_t * k,
 276                                                     u32 * address_indexp,
 277                                                     u16 port_per_thread,
 278                                                     u32 snat_thread_index);
 279
 280 typedef struct snat_main_s {
 281   /* Endpoint address dependent sessions lookup tables */
 282   clib_bihash_16_8_t out2in_ed;
 283   clib_bihash_16_8_t in2out_ed;
 284
 285   snat_icmp_match_function_t * icmp_match_in2out_cb;
 286   snat_icmp_match_function_t * icmp_match_out2in_cb;
 287
 288   u32 num_workers;
 289   u32 first_worker_index;
 290   u32 next_worker;
 291   u32 * workers;
 292   snat_get_worker_function_t * worker_in2out_cb;
 293   snat_get_worker_function_t * worker_out2in_cb;
 294   u16 port_per_thread;
 295   u32 num_snat_thread;
 296
 297   /* Per thread data */
 298   snat_main_per_thread_data_t * per_thread_data;
 299
 300   /* Find a static mapping by local */
 301   clib_bihash_8_8_t static_mapping_by_local;
 302
 303   /* Find a static mapping by external */
 304   clib_bihash_8_8_t static_mapping_by_external;
 305
 306   /* Static mapping pool */
 307   snat_static_mapping_t * static_mappings;
 308
 309   /* Interface pool */
 310   snat_interface_t * interfaces;
 311   snat_interface_t * output_feature_interfaces;
 312
 313   /* Vector of outside addresses */
 314   snat_address_t * addresses;
 315   nat_alloc_out_addr_and_port_function_t *alloc_addr_and_port;
 316   u8 psid_offset;
 317   u8 psid_length;
 318   u16 psid;
 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   /* values of various timeouts */
 358   u32 udp_timeout;
 359   u32 tcp_established_timeout;
 360   u32 tcp_transitory_timeout;
 361   u32 icmp_timeout;
 362
 363   /* API message ID base */
 364   u16 msg_id_base;
 365
 366   /* convenience */
 367   vlib_main_t * vlib_main;
 368   vnet_main_t * vnet_main;
 369   ip4_main_t * ip4_main;
 370   ip_lookup_main_t * ip4_lookup_main;
 371   api_main_t * api_main;
 372 } snat_main_t;
 373
 374 extern snat_main_t snat_main;
 375 extern vlib_node_registration_t snat_in2out_node;
 376 extern vlib_node_registration_t snat_in2out_output_node;
 377 extern vlib_node_registration_t snat_out2in_node;
 378 extern vlib_node_registration_t snat_in2out_fast_node;
 379 extern vlib_node_registration_t snat_out2in_fast_node;
 380 extern vlib_node_registration_t snat_in2out_worker_handoff_node;
 381 extern vlib_node_registration_t snat_in2out_output_worker_handoff_node;
 382 extern vlib_node_registration_t snat_out2in_worker_handoff_node;
 383 extern vlib_node_registration_t snat_det_in2out_node;
 384 extern vlib_node_registration_t snat_det_out2in_node;
 385 extern vlib_node_registration_t snat_hairpin_dst_node;
 386 extern vlib_node_registration_t snat_hairpin_src_node;
 387
 388 void snat_free_outside_address_and_port (snat_address_t * addresses,
 389                                          u32 thread_index,
 390                                          snat_session_key_t * k,
 391                                          u32 address_index);
 392
 393 int snat_alloc_outside_address_and_port (snat_address_t * addresses,
 394                                          u32 fib_index,
 395                                          u32 thread_index,
 396                                          snat_session_key_t * k,
 397                                          u32 * address_indexp,
 398                                          u16 port_per_thread,
 399                                          u32 snat_thread_index);
 400
 401 int snat_static_mapping_match (snat_main_t * sm,
 402                                snat_session_key_t match,
 403                                snat_session_key_t * mapping,
 404                                u8 by_external,
 405                                u8 *is_addr_only);
 406
 407 void snat_add_del_addr_to_fib (ip4_address_t * addr,
 408                                u8 p_len,
 409                                u32 sw_if_index,
 410                                int is_add);
 411
 412 format_function_t format_snat_user;
 413
 414 typedef struct {
 415   u32 cached_sw_if_index;
 416   u32 cached_ip4_address;
 417 } snat_runtime_t;
 418
 419 /** \brief Check if SNAT session is created from static mapping.
 420     @param s SNAT session
 421     @return 1 if SNAT session is created from static mapping otherwise 0
 422 */
 423 #define snat_is_session_static(s) (s->flags & SNAT_SESSION_FLAG_STATIC_MAPPING)
 424
 425 /** \brief Check if SNAT session for unknown protocol.
 426     @param s SNAT session
 427     @return 1 if SNAT session for unknown protocol otherwise 0
 428 */
 429 #define snat_is_unk_proto_session(s) s->flags & SNAT_SESSION_FLAG_UNKNOWN_PROTO
 430
 431 #define nat_interface_is_inside(i) i->flags & NAT_INTERFACE_FLAG_IS_INSIDE
 432 #define nat_interface_is_outside(i) i->flags & NAT_INTERFACE_FLAG_IS_OUTSIDE
 433
 434 /*
 435  * Why is this here? Because we don't need to touch this layer to
 436  * simply reply to an icmp. We need to change id to a unique
 437  * value to NAT an echo request/reply.
 438  */
 439
 440 typedef struct {
 441   u16 identifier;
 442   u16 sequence;
 443 } icmp_echo_header_t;
 444
 445 always_inline u32
 446 ip_proto_to_snat_proto (u8 ip_proto)
 447 {
 448   u32 snat_proto = ~0;
 449
 450   snat_proto = (ip_proto == IP_PROTOCOL_UDP) ? SNAT_PROTOCOL_UDP : snat_proto;
 451   snat_proto = (ip_proto == IP_PROTOCOL_TCP) ? SNAT_PROTOCOL_TCP : snat_proto;
 452   snat_proto = (ip_proto == IP_PROTOCOL_ICMP) ? SNAT_PROTOCOL_ICMP : snat_proto;
 453   snat_proto = (ip_proto == IP_PROTOCOL_ICMP6) ? SNAT_PROTOCOL_ICMP : snat_proto;
 454
 455   return snat_proto;
 456 }
 457
 458 always_inline u8
 459 snat_proto_to_ip_proto (snat_protocol_t snat_proto)
 460 {
 461   u8 ip_proto = ~0;
 462
 463   ip_proto = (snat_proto == SNAT_PROTOCOL_UDP) ? IP_PROTOCOL_UDP : ip_proto;
 464   ip_proto = (snat_proto == SNAT_PROTOCOL_TCP) ? IP_PROTOCOL_TCP : ip_proto;
 465   ip_proto = (snat_proto == SNAT_PROTOCOL_ICMP) ? IP_PROTOCOL_ICMP : ip_proto;
 466
 467   return ip_proto;
 468 }
 469
 470 typedef struct {
 471   u16 src_port, dst_port;
 472 } tcp_udp_header_t;
 473
 474 u32 icmp_match_in2out_fast(snat_main_t *sm, vlib_node_runtime_t *node,
 475                            u32 thread_index, vlib_buffer_t *b0,
 476                            ip4_header_t *ip0, u8 *p_proto,
 477                            snat_session_key_t *p_value,
 478                            u8 *p_dont_translate, void *d, void *e);
 479 u32 icmp_match_in2out_slow(snat_main_t *sm, vlib_node_runtime_t *node,
 480                            u32 thread_index, vlib_buffer_t *b0,
 481                            ip4_header_t *ip0, u8 *p_proto,
 482                            snat_session_key_t *p_value,
 483                            u8 *p_dont_translate, void *d, void *e);
 484 u32 icmp_match_in2out_det(snat_main_t *sm, vlib_node_runtime_t *node,
 485                           u32 thread_index, vlib_buffer_t *b0,
 486                           ip4_header_t *ip0, u8 *p_proto,
 487                           snat_session_key_t *p_value,
 488                           u8 *p_dont_translate, void *d, void *e);
 489 u32 icmp_match_out2in_fast(snat_main_t *sm, vlib_node_runtime_t *node,
 490                            u32 thread_index, vlib_buffer_t *b0,
 491                            ip4_header_t *ip0, u8 *p_proto,
 492                            snat_session_key_t *p_value,
 493                            u8 *p_dont_translate, void *d, void *e);
 494 u32 icmp_match_out2in_slow(snat_main_t *sm, vlib_node_runtime_t *node,
 495                            u32 thread_index, vlib_buffer_t *b0,
 496                            ip4_header_t *ip0, u8 *p_proto,
 497                            snat_session_key_t *p_value,
 498                            u8 *p_dont_translate, void *d, void *e);
 499 u32 icmp_match_out2in_det(snat_main_t *sm, vlib_node_runtime_t *node,
 500                           u32 thread_index, vlib_buffer_t *b0,
 501                           ip4_header_t *ip0, u8 *p_proto,
 502                           snat_session_key_t *p_value,
 503                           u8 *p_dont_translate, void *d, void *e);
 504 void increment_v4_address(ip4_address_t * a);
 505 void snat_add_address(snat_main_t *sm, ip4_address_t *addr, u32 vrf_id);
 506 int snat_del_address(snat_main_t *sm, ip4_address_t addr, u8 delete_sm);
 507 int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
 508                             u16 l_port, u16 e_port, u32 vrf_id, int addr_only,
 509                             u32 sw_if_index, snat_protocol_t proto, int is_add);
 510 clib_error_t * snat_api_init(vlib_main_t * vm, snat_main_t * sm);
 511 int snat_set_workers (uword * bitmap);
 512 int snat_interface_add_del(u32 sw_if_index, u8 is_inside, int is_del);
 513 int snat_interface_add_del_output_feature(u32 sw_if_index, u8 is_inside,
 514                                           int is_del);
 515 int snat_add_interface_address(snat_main_t *sm, u32 sw_if_index, int is_del);
 516 uword unformat_snat_protocol(unformat_input_t * input, va_list * args);
 517 u8 * format_snat_protocol(u8 * s, va_list * args);
 518 int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
 519                                      snat_protocol_t proto, u32 vrf_id,
 520                                      nat44_lb_addr_port_t *locals, u8 is_add);
 521 int nat44_del_session (snat_main_t *sm, ip4_address_t *addr, u16 port,
 522                        snat_protocol_t proto, u32 vrf_id, int is_in);
 523
 524 static_always_inline u8
 525 icmp_is_error_message (icmp46_header_t * icmp)
 526 {
 527   switch(icmp->type)
 528     {
 529     case ICMP4_destination_unreachable:
 530     case ICMP4_time_exceeded:
 531     case ICMP4_parameter_problem:
 532     case ICMP4_source_quench:
 533     case ICMP4_redirect:
 534     case ICMP4_alternate_host_address:
 535       return 1;
 536     }
 537   return 0;
 538 }
 539
 540 static_always_inline u8
 541 is_interface_addr(snat_main_t *sm, vlib_node_runtime_t *node, u32 sw_if_index0,
 542                   u32 ip4_addr)
 543 {
 544   snat_runtime_t *rt = (snat_runtime_t *) node->runtime_data;
 545   ip4_address_t * first_int_addr;
 546
 547   if (PREDICT_FALSE(rt->cached_sw_if_index != sw_if_index0))
 548     {
 549       first_int_addr =
 550         ip4_interface_first_address (sm->ip4_main, sw_if_index0,
 551                                      0 /* just want the address */);
 552       rt->cached_sw_if_index = sw_if_index0;
 553       if (first_int_addr)
 554         rt->cached_ip4_address = first_int_addr->as_u32;
 555       else
 556         rt->cached_ip4_address = 0;
 557     }
 558
 559   if (PREDICT_FALSE(ip4_addr == rt->cached_ip4_address))
 560     return 1;
 561   else
 562     return 0;
 563 }
 564
 565 always_inline u8
 566 maximum_sessions_exceeded (snat_main_t *sm, u32 thread_index)
 567 {
 568   if (pool_elts (sm->per_thread_data[thread_index].sessions) >= sm->max_translations)
 569     return 1;
 570
 571   return 0;
 572 }
 573
 574 static_always_inline void
 575 nat_send_all_to_node(vlib_main_t *vm, u32 *bi_vector,
 576                      vlib_node_runtime_t *node, vlib_error_t *error, u32 next)
 577 {
 578   u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
 579
 580   from = bi_vector;
 581   n_left_from = vec_len(bi_vector);
 582   next_index = node->cached_next_index;
 583   while (n_left_from > 0) {
 584     vlib_get_next_frame(vm, node, next_index, to_next, n_left_to_next);
 585     while (n_left_from > 0 && n_left_to_next > 0) {
 586       u32 bi0 = to_next[0] = from[0];
 587       from += 1;
 588       n_left_from -= 1;
 589       to_next += 1;
 590       n_left_to_next -= 1;
 591       vlib_buffer_t *p0 = vlib_get_buffer(vm, bi0);
 592       p0->error = *error;
 593       vlib_validate_buffer_enqueue_x1(vm, node, next_index, to_next,
 594                                       n_left_to_next, bi0, next);
 595     }
 596     vlib_put_next_frame(vm, node, next_index, n_left_to_next);
 597   }
 598 }
 599
 600 #endif /* __included_snat_h__ */