aboutsummaryrefslogtreecommitdiffstats
path: root/src/plugins/snat/snat.h
blob: 92b2f7eae80ea4f5d1b0fdf8df2bb6ecc128266d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
/*
 * snat.h - simple nat definitions
 *
 * Copyright (c) 2016 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#ifndef __included_snat_h__
#define __included_snat_h__

#include <vnet/vnet.h>
#include <vnet/ip/ip.h>
#include <vnet/ethernet/ethernet.h>
#include <vnet/ip/icmp46_packet.h>
#include <vnet/api_errno.h>
#include <vppinfra/bihash_8_8.h>
#include <vppinfra/dlist.h>
#include <vppinfra/error.h>
#include <vlibapi/api.h>


#define SNAT_UDP_TIMEOUT 300
#define SNAT_TCP_TRANSITORY_TIMEOUT 240
#define SNAT_TCP_ESTABLISHED_TIMEOUT 7440

/* Key */
typedef struct {
  union 
  {
    struct 
    {
      ip4_address_t addr;
      u16 port;
      u16 protocol:3,
        fib_index:13;
    };
    u64 as_u64;
  };
} snat_session_key_t;

typedef struct {
  union
  {
    struct
    {
      ip4_address_t ext_host_addr;
      u16 ext_host_port;
      u16 out_port;
    };
    u64 as_u64;
  };
} snat_det_out_key_t;

typedef struct {
  union
  {
    struct
    {
      ip4_address_t addr;
      u32 fib_index;
    };
    u64 as_u64;
  };
} snat_user_key_t;

typedef struct {
  union
  {
    struct
    {
      ip4_address_t addr;
      u16 port;
      u16 fib_index;
    };
    u64 as_u64;
  };
} snat_worker_key_t;


#define foreach_snat_protocol \
  _(UDP, 0, udp, "udp")       \
  _(TCP, 1, tcp, "tcp")       \
  _(ICMP, 2, icmp, "icmp")

typedef enum {
#define _(N, i, n, s) SNAT_PROTOCOL_##N = i,
  foreach_snat_protocol
#undef _
} snat_protocol_t;


#define foreach_snat_session_state          \
  _(0, UNKNOWN, "unknown")                 \
  _(1, UDP_ACTIVE, "udp-active")           \
  _(2, TCP_SYN_SENT, "tcp-syn-sent")       \
  _(3, TCP_ESTABLISHED, "tcp-established") \
  _(4, TCP_FIN_WAIT, "tcp-fin-wait")       \
  _(5, TCP_CLOSE_WAIT, "tcp-close-wait")   \
  _(6, TCP_LAST_ACK, "tcp-last-ack")

typedef enum {
#define _(v, N, s) SNAT_SESSION_##N = v,
  foreach_snat_session_state
#undef _
} snat_session_state_t;


#define SNAT_SESSION_FLAG_STATIC_MAPPING 1

typedef CLIB_PACKED(struct {
  snat_session_key_t out2in;    /* 0-15 */

  snat_session_key_t in2out;    /* 16-31 */

  u32 flags;                    /* 32-35 */

  /* per-user translations */
  u32 per_user_index;           /* 36-39 */

  u32 per_user_list_head_index; /* 40-43 */

  /* Last heard timer */
  f64 last_heard;               /* 44-51 */

  u64 total_bytes;              /* 52-59 */
  
  u32 total_pkts;               /* 60-63 */

  /* Outside address */
  u32 outside_address_index;    /* 64-67 */

}) snat_session_t;


typedef struct {
  ip4_address_t addr;
  u32 fib_index;
  u32 sessions_per_user_list_head_index;
  u32 nsessions;
  u32 nstaticsessions;
} snat_user_t;

typedef struct {
  ip4_address_t addr;
  u32 fib_index;
#define _(N, i, n, s) \
  u32 busy_##n##_ports; \
  uword * busy_##n##_port_bitmap;
  foreach_snat_protocol
#undef _
} snat_address_t;

typedef struct {
  u16 in_port;
  snat_det_out_key_t out;
  u8 state;
  u32 expire;
} snat_det_session_t;

typedef struct {
  ip4_address_t in_addr;
  u8 in_plen;
  ip4_address_t out_addr;
  u8 out_plen;
  u32 sharing_ratio;
  u16 ports_per_host;
  u32 ses_num;
  /* vector of sessions */
  snat_det_session_t * sessions;
} snat_det_map_t;

typedef struct {
  ip4_address_t local_addr;
  ip4_address_t external_addr;
  u16 local_port;
  u16 external_port;
  u8 addr_only;
  u32 vrf_id;
  u32 fib_index;
  snat_protocol_t proto;
} snat_static_mapping_t;

typedef struct {
  u32 sw_if_index;
  u8 is_inside;
} snat_interface_t;

typedef struct {
  ip4_address_t l_addr;
  u16 l_port;
  u16 e_port;
  u32 sw_if_index;
  u32 vrf_id;
  snat_protocol_t proto;
  int addr_only;
  int is_add;
} snat_static_map_resolve_t;

typedef struct {
  /* User pool */
  snat_user_t * users;

  /* Session pool */
  snat_session_t * sessions;

  /* Pool of doubly-linked list elements */
  dlist_elt_t * list_pool;
} snat_main_per_thread_data_t;

struct snat_main_s;

typedef u32 snat_icmp_match_function_t (struct snat_main_s *sm,
                                        vlib_node_runtime_t *node,
                                        u32 thread_index,
                                        vlib_buffer_t *b0,
                                        u8 *p_proto,
                                        snat_session_key_t *p_value,
                                        u8 *p_dont_translate,
                                        void *d);

typedef u32 (snat_get_worker_function_t) (ip4_header_t * ip, u32 rx_fib_index);

typedef struct snat_main_s {
  /* Main lookup tables */
  clib_bihash_8_8_t out2in;
  clib_bihash_8_8_t in2out;

  /* Find-a-user => src address lookup */
  clib_bihash_8_8_t user_hash;

  /* Non-translated packets worker lookup => src address + VRF */
  clib_bihash_8_8_t worker_by_in;

  /* Translated packets worker lookup => IP address + port number */
  clib_bihash_8_8_t worker_by_out;

  snat_icmp_match_function_t * icmp_match_in2out_cb;
  snat_icmp_match_function_t * icmp_match_out2in_cb;

  u32 num_workers;
  u32 first_worker_index;
  u32 next_worker;
  u32 * workers;
  snat_get_worker_function_t * worker_in2out_cb;
  snat_get_worker_function_t * worker_out2in_cb;

  /* Per thread data */
  snat_main_per_thread_data_t * per_thread_data;

  /* Find a static mapping by local */
  clib_bihash_8_8_t static_mapping_by_local;

  /* Find a static mapping by external */
  clib_bihash_8_8_t static_mapping_by_external;

  /* Static mapping pool */
  snat_static_mapping_t * static_mappings;

  /* Interface pool */
  snat_interface_t * interfaces;

  /* Vector of outside addresses */
  snat_address_t * addresses;

  /* sw_if_indices whose intfc addresses should be auto-added */
  u32 * auto_add_sw_if_indices;

  /* vector of interface address static mappings to resolve. */
  snat_static_map_resolve_t *to_resolve;

  /* Randomize port allocation order */
  u32 random_seed;

  /* Worker handoff index */
  u32 fq_in2out_index;
  u32 fq_out2in_index;

  /* in2out and out2in node index */
  u32 in2out_node_index;
  u32 out2in_node_index;

  /* Deterministic NAT */
  snat_det_map_t * det_maps;

  /* Config parameters */
  u8 static_mapping_only;
  u8 static_mapping_connection_tracking;
  u8 deterministic;
  u32 translation_buckets;
  u32 translation_memory_size;
  u32 user_buckets;
  u32 user_memory_size;
  u32 max_translations_per_user;
  u32 outside_vrf_id;
  u32 outside_fib_index;
  u32 inside_vrf_id;
  u32 inside_fib_index;

  /* tenant VRF aware address pool activation flag */
  u8 vrf_mode;

  /* API message ID base */
  u16 msg_id_base;

  /* convenience */
  vlib_main_t * vlib_main;
  vnet_main_t * vnet_main;
  ip4_main_t * ip4_main;
  ip_lookup_main_t * ip4_lookup_main;
  api_main_t * api_main;
} snat_main_t;

extern snat_main_t snat_main;
extern vlib_node_registration_t snat_in2out_node;
extern vlib_node_registration_t snat_out2in_node;
extern vlib_node_registration_t snat_in2out_fast_node;
extern vlib_node_registration_t snat_out2in_fast_node;
extern vlib_node_registration_t snat_in2out_worker_handoff_node;
extern vlib_node_registration_t snat_out2in_worker_handoff_node;
extern vlib_node_registration_t snat_det_in2out_node;
extern vlib_node_registration_t snat_det_out2in_node;

void snat_free_outside_address_and_port (snat_main_t * sm, 
                                         snat_session_key_t * k, 
                                         u32 address_index);

int snat_alloc_outside_address_and_port (snat_main_t * sm, 
                                         u32 fib_index,
                                         snat_session_key_t * k,
                                         u32 * address_indexp);

int snat_static_mapping_match (snat_main_t * sm,
                               snat_session_key_t match,
                               snat_session_key_t * mapping,
                               u8 by_external);

void snat_add_del_addr_to_fib (ip4_address_t * addr,
                               u8 p_len,
                               u32 sw_if_index,
                               int is_add);

format_function_t format_snat_user;

typedef struct {
  u32 cached_sw_if_index;
  u32 cached_ip4_address;
} snat_runtime_t;

/** \brief Check if SNAT session is created from static mapping.
    @param s SNAT session
    @return 1 if SNAT session is created from static mapping otherwise 0
*/
#define snat_is_session_static(s) s->flags & SNAT_SESSION_FLAG_STATIC_MAPPING

/* 
 * Why is this here? Because we don't need to touch this layer to
 * simply reply to an icmp. We need to change id to a unique
 * value to NAT an echo request/reply.
 */
   
typedef struct {
  u16 identifier;
  u16 sequence;
} icmp_echo_header_t;

always_inline snat_protocol_t
ip_proto_to_snat_proto (u8 ip_proto)
{
  snat_protocol_t snat_proto = ~0;

  snat_proto = (ip_proto == IP_PROTOCOL_UDP) ? SNAT_PROTOCOL_UDP : snat_proto;
  snat_proto = (ip_proto == IP_PROTOCOL_TCP) ? SNAT_PROTOCOL_TCP : snat_proto;
  snat_proto = (ip_proto == IP_PROTOCOL_ICMP) ? SNAT_PROTOCOL_ICMP : snat_proto;

  return snat_proto;
}

always_inline u8
snat_proto_to_ip_proto (snat_protocol_t snat_proto)
{
  u8 ip_proto = ~0;

  ip_proto = (snat_proto == SNAT_PROTOCOL_UDP) ? IP_PROTOCOL_UDP : ip_proto;
  ip_proto = (snat_proto == SNAT_PROTOCOL_TCP) ? IP_PROTOCOL_TCP : ip_proto;
  ip_proto = (snat_proto == SNAT_PROTOCOL_ICMP) ? IP_PROTOCOL_ICMP : ip_proto;

  return ip_proto;
}

typedef struct {
  u16 src_port, dst_port;
} tcp_udp_header_t;

u32 icmp_match_in2out_fast(snat_main_t *sm, vlib_node_runtime_t *node,
                           u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
                           snat_session_key_t *p_value,
                           u8 *p_dont_translate, void *d);
u32 icmp_match_in2out_slow(snat_main_t *sm, vlib_node_runtime_t *node,
                           u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
                           snat_session_key_t *p_value,
                           u8 *p_dont_translate, void *d);
u32 icmp_match_out2in_fast(snat_main_t *sm, vlib_node_runtime_t *node,
                           u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
                           snat_session_key_t *p_value,
                           u8 *p_dont_translate, void *d);
u32 icmp_match_out2in_slow(snat_main_t *sm, vlib_node_runtime_t *node,
                           u32 thread_index, vlib_buffer_t *b0, u8 *p_proto,
                           snat_session_key_t *p_value,
                           u8 *p_dont_translate, void *d);

static_always_inline u8
icmp_is_error_message (icmp46_header_t * icmp)
{
  switch(icmp->type)
    {
    case ICMP4_destination_unreachable:
    case ICMP4_time_exceeded:
    case ICMP4_parameter_problem:
    case ICMP4_source_quench:
    case ICMP4_redirect:
    case ICMP4_alternate_host_address:
      return 1;
    }
  return 0;
}

static_always_inline u8
is_interface_addr(snat_main_t *sm, vlib_node_runtime_t *node, u32 sw_if_index0,
                  u32 ip4_addr)
{
  snat_runtime_t *rt = (snat_runtime_t *) node->runtime_data;
  ip4_address_t * first_int_addr;

  if (PREDICT_FALSE(rt->cached_sw_if_index != sw_if_index0))
    {
      first_int_addr =
        ip4_interface_first_address (sm->ip4_main, sw_if_index0,
                                     0 /* just want the address */);
      rt->cached_sw_if_index = sw_if_index0;
      if (first_int_addr)
        rt->cached_ip4_address = first_int_addr->as_u32;
      else
        rt->cached_ip4_address = 0;
    }

  if (PREDICT_FALSE(ip4_addr == rt->cached_ip4_address))
    return 1;
  else
    return 0;
}

#endif /* __included_snat_h__ */