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                                                     u8 vrf_mode,
 278                                                     u16 port_per_thread,
 279                                                     u32 snat_thread_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   snat_icmp_match_function_t * icmp_match_in2out_cb;
 287   snat_icmp_match_function_t * icmp_match_out2in_cb;
 288
 289   u32 num_workers;
 290   u32 first_worker_index;
 291   u32 next_worker;
 292   u32 * workers;
 293   snat_get_worker_function_t * worker_in2out_cb;
 294   snat_get_worker_function_t * worker_out2in_cb;
 295   u16 port_per_thread;
 296   u32 num_snat_thread;
 297
 298   /* Per thread data */
 299   snat_main_per_thread_data_t * per_thread_data;
 300
 301   /* Find a static mapping by local */
 302   clib_bihash_8_8_t static_mapping_by_local;
 303
 304   /* Find a static mapping by external */
 305   clib_bihash_8_8_t static_mapping_by_external;
 306
 307   /* Static mapping pool */
 308   snat_static_mapping_t * static_mappings;
 309
 310   /* Interface pool */
 311   snat_interface_t * interfaces;
 312   snat_interface_t * output_feature_interfaces;
 313
 314   /* Vector of outside addresses */
 315   snat_address_t * addresses;
 316   nat_alloc_out_addr_and_port_function_t *alloc_addr_and_port;
 317   u8 psid_offset;
 318   u8 psid_length;
 319   u16 psid;
 320
 321   /* sw_if_indices whose intfc addresses should be auto-added */
 322   u32 * auto_add_sw_if_indices;
 323
 324   /* vector of interface address static mappings to resolve. */
 325   snat_static_map_resolve_t *to_resolve;
 326
 327   /* Randomize port allocation order */
 328   u32 random_seed;
 329
 330   /* Worker handoff index */
 331   u32 fq_in2out_index;
 332   u32 fq_in2out_output_index;
 333   u32 fq_out2in_index;
 334
 335   /* in2out and out2in node index */
 336   u32 in2out_node_index;
 337   u32 in2out_output_node_index;
 338   u32 out2in_node_index;
 339
 340   /* Deterministic NAT */
 341   snat_det_map_t * det_maps;
 342
 343   /* Config parameters */
 344   u8 static_mapping_only;
 345   u8 static_mapping_connection_tracking;
 346   u8 deterministic;
 347   u32 translation_buckets;
 348   u32 translation_memory_size;
 349   u32 max_translations;
 350   u32 user_buckets;
 351   u32 user_memory_size;
 352   u32 max_translations_per_user;
 353   u32 outside_vrf_id;
 354   u32 outside_fib_index;
 355   u32 inside_vrf_id;
 356   u32 inside_fib_index;
 357
 358   /* tenant VRF aware address pool activation flag */
 359   u8 vrf_mode;
 360
 361   /* values of various timeouts */
 362   u32 udp_timeout;
 363   u32 tcp_established_timeout;
 364   u32 tcp_transitory_timeout;
 365   u32 icmp_timeout;
 366
 367   /* API message ID base */
 368   u16 msg_id_base;
 369
 370   /* convenience */
 371   vlib_main_t * vlib_main;
 372   vnet_main_t * vnet_main;
 373   ip4_main_t * ip4_main;
 374   ip_lookup_main_t * ip4_lookup_main;
 375   api_main_t * api_main;
 376 } snat_main_t;
 377
 378 extern snat_main_t snat_main;
 379 extern vlib_node_registration_t snat_in2out_node;
 380 extern vlib_node_registration_t snat_in2out_output_node;
 381 extern vlib_node_registration_t snat_out2in_node;
 382 extern vlib_node_registration_t snat_in2out_fast_node;
 383 extern vlib_node_registration_t snat_out2in_fast_node;
 384 extern vlib_node_registration_t snat_in2out_worker_handoff_node;
 385 extern vlib_node_registration_t snat_in2out_output_worker_handoff_node;
 386 extern vlib_node_registration_t snat_out2in_worker_handoff_node;
 387 extern vlib_node_registration_t snat_det_in2out_node;
 388 extern vlib_node_registration_t snat_det_out2in_node;
 389 extern vlib_node_registration_t snat_hairpin_dst_node;
 390 extern vlib_node_registration_t snat_hairpin_src_node;
 391
 392 void snat_free_outside_address_and_port (snat_address_t * addresses,
 393                                          u32 thread_index,
 394                                          snat_session_key_t * k,
 395                                          u32 address_index);
 396
 397 int snat_alloc_outside_address_and_port (snat_address_t * addresses,
 398                                          u32 fib_index,
 399                                          u32 thread_index,
 400                                          snat_session_key_t * k,
 401                                          u32 * address_indexp,
 402                                          u8 vrf_mode,
 403                                          u16 port_per_thread,
 404                                          u32 snat_thread_index);
 405
 406 int snat_static_mapping_match (snat_main_t * sm,
 407                                snat_session_key_t match,
 408                                snat_session_key_t * mapping,
 409                                u8 by_external,
 410                                u8 *is_addr_only);
 411
 412 void snat_add_del_addr_to_fib (ip4_address_t * addr,
 413                                u8 p_len,
 414                                u32 sw_if_index,
 415                                int is_add);
 416
 417 format_function_t format_snat_user;
 418
 419 typedef struct {
 420   u32 cached_sw_if_index;
 421   u32 cached_ip4_address;
 422 } snat_runtime_t;
 423
 424 /** \brief Check if SNAT session is created from static mapping.
 425     @param s SNAT session
 426     @return 1 if SNAT session is created from static mapping otherwise 0
 427 */
 428 #define snat_is_session_static(s) (s->flags & SNAT_SESSION_FLAG_STATIC_MAPPING)
 429
 430 /** \brief Check if SNAT session for unknown protocol.
 431     @param s SNAT session
 432     @return 1 if SNAT session for unknown protocol otherwise 0
 433 */
 434 #define snat_is_unk_proto_session(s) s->flags & SNAT_SESSION_FLAG_UNKNOWN_PROTO
 435
 436 #define nat_interface_is_inside(i) i->flags & NAT_INTERFACE_FLAG_IS_INSIDE
 437 #define nat_interface_is_outside(i) i->flags & NAT_INTERFACE_FLAG_IS_OUTSIDE
 438
 439 /*
 440  * Why is this here? Because we don't need to touch this layer to
 441  * simply reply to an icmp. We need to change id to a unique
 442  * value to NAT an echo request/reply.
 443  */
 444
 445 typedef struct {
 446   u16 identifier;
 447   u16 sequence;
 448 } icmp_echo_header_t;
 449
 450 always_inline u32
 451 ip_proto_to_snat_proto (u8 ip_proto)
 452 {
 453   u32 snat_proto = ~0;
 454
 455   snat_proto = (ip_proto == IP_PROTOCOL_UDP) ? SNAT_PROTOCOL_UDP : snat_proto;
 456   snat_proto = (ip_proto == IP_PROTOCOL_TCP) ? SNAT_PROTOCOL_TCP : snat_proto;
 457   snat_proto = (ip_proto == IP_PROTOCOL_ICMP) ? SNAT_PROTOCOL_ICMP : snat_proto;
 458   snat_proto = (ip_proto == IP_PROTOCOL_ICMP6) ? SNAT_PROTOCOL_ICMP : snat_proto;
 459
 460   return snat_proto;
 461 }
 462
 463 always_inline u8
 464 snat_proto_to_ip_proto (snat_protocol_t snat_proto)
 465 {
 466   u8 ip_proto = ~0;
 467
 468   ip_proto = (snat_proto == SNAT_PROTOCOL_UDP) ? IP_PROTOCOL_UDP : ip_proto;
 469   ip_proto = (snat_proto == SNAT_PROTOCOL_TCP) ? IP_PROTOCOL_TCP : ip_proto;
 470   ip_proto = (snat_proto == SNAT_PROTOCOL_ICMP) ? IP_PROTOCOL_ICMP : ip_proto;
 471
 472   return ip_proto;
 473 }
 474
 475 typedef struct {
 476   u16 src_port, dst_port;
 477 } tcp_udp_header_t;
 478
 479 u32 icmp_match_in2out_fast(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_slow(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_in2out_det(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_fast(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_slow(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 u32 icmp_match_out2in_det(snat_main_t *sm, vlib_node_runtime_t *node,
 505                           u32 thread_index, vlib_buffer_t *b0,
 506                           ip4_header_t *ip0, u8 *p_proto,
 507                           snat_session_key_t *p_value,
 508                           u8 *p_dont_translate, void *d, void *e);
 509 void increment_v4_address(ip4_address_t * a);
 510 void snat_add_address(snat_main_t *sm, ip4_address_t *addr, u32 vrf_id);
 511 int snat_del_address(snat_main_t *sm, ip4_address_t addr, u8 delete_sm);
 512 int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
 513                             u16 l_port, u16 e_port, u32 vrf_id, int addr_only,
 514                             u32 sw_if_index, snat_protocol_t proto, int is_add);
 515 clib_error_t * snat_api_init(vlib_main_t * vm, snat_main_t * sm);
 516 int snat_set_workers (uword * bitmap);
 517 int snat_interface_add_del(u32 sw_if_index, u8 is_inside, int is_del);
 518 int snat_interface_add_del_output_feature(u32 sw_if_index, u8 is_inside,
 519                                           int is_del);
 520 int snat_add_interface_address(snat_main_t *sm, u32 sw_if_index, int is_del);
 521 uword unformat_snat_protocol(unformat_input_t * input, va_list * args);
 522 u8 * format_snat_protocol(u8 * s, va_list * args);
 523 int nat44_add_del_lb_static_mapping (ip4_address_t e_addr, u16 e_port,
 524                                      snat_protocol_t proto, u32 vrf_id,
 525                                      nat44_lb_addr_port_t *locals, u8 is_add);
 526 int nat44_del_session (snat_main_t *sm, ip4_address_t *addr, u16 port,
 527                        snat_protocol_t proto, u32 vrf_id, int is_in);
 528
 529 static_always_inline u8
 530 icmp_is_error_message (icmp46_header_t * icmp)
 531 {
 532   switch(icmp->type)
 533     {
 534     case ICMP4_destination_unreachable:
 535     case ICMP4_time_exceeded:
 536     case ICMP4_parameter_problem:
 537     case ICMP4_source_quench:
 538     case ICMP4_redirect:
 539     case ICMP4_alternate_host_address:
 540       return 1;
 541     }
 542   return 0;
 543 }
 544
 545 static_always_inline u8
 546 is_interface_addr(snat_main_t *sm, vlib_node_runtime_t *node, u32 sw_if_index0,
 547                   u32 ip4_addr)
 548 {
 549   snat_runtime_t *rt = (snat_runtime_t *) node->runtime_data;
 550   ip4_address_t * first_int_addr;
 551
 552   if (PREDICT_FALSE(rt->cached_sw_if_index != sw_if_index0))
 553     {
 554       first_int_addr =
 555         ip4_interface_first_address (sm->ip4_main, sw_if_index0,
 556                                      0 /* just want the address */);
 557       rt->cached_sw_if_index = sw_if_index0;
 558       if (first_int_addr)
 559         rt->cached_ip4_address = first_int_addr->as_u32;
 560       else
 561         rt->cached_ip4_address = 0;
 562     }
 563
 564   if (PREDICT_FALSE(ip4_addr == rt->cached_ip4_address))
 565     return 1;
 566   else
 567     return 0;
 568 }
 569
 570 always_inline u8
 571 maximum_sessions_exceeded (snat_main_t *sm, u32 thread_index)
 572 {
 573   if (pool_elts (sm->per_thread_data[thread_index].sessions) >= sm->max_translations)
 574     return 1;
 575
 576   return 0;
 577 }
 578
 579 static_always_inline void
 580 nat_send_all_to_node(vlib_main_t *vm, u32 *bi_vector,
 581                      vlib_node_runtime_t *node, vlib_error_t *error, u32 next)
 582 {
 583   u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
 584
 585   from = bi_vector;
 586   n_left_from = vec_len(bi_vector);
 587   next_index = node->cached_next_index;
 588   while (n_left_from > 0) {
 589     vlib_get_next_frame(vm, node, next_index, to_next, n_left_to_next);
 590     while (n_left_from > 0 && n_left_to_next > 0) {
 591       u32 bi0 = to_next[0] = from[0];
 592       from += 1;
 593       n_left_from -= 1;
 594       to_next += 1;
 595       n_left_to_next -= 1;
 596       vlib_buffer_t *p0 = vlib_get_buffer(vm, bi0);
 597       p0->error = *error;
 598       vlib_validate_buffer_enqueue_x1(vm, node, next_index, to_next,
 599                                       n_left_to_next, bi0, next);
 600     }
 601     vlib_put_next_frame(vm, node, next_index, n_left_to_next);
 602   }
 603 }
 604
 605 #endif /* __included_snat_h__ */