summaryrefslogtreecommitdiffstats
path: root/src/plugins/nat/det44/det44.c
blob: a8aea28d94831dbe02e791b578af87fbe31923ce (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
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
/*
 * det44.c - deterministic NAT
 *
 * Copyright (c) 2020 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.
 */
/**
 * @file
 * @brief deterministic NAT (CGN)
 */

#include <vnet/vnet.h>
#include <vnet/ip/ip.h>
#include <vnet/ip/ip4.h>
#include <vpp/app/version.h>
#include <vnet/plugin/plugin.h>

#include <nat/det44/det44.h>

det44_main_t det44_main;

/* *INDENT-OFF* */
VNET_FEATURE_INIT (ip4_det44_in2out, static) = {
  .arc_name = "ip4-unicast",
  .node_name = "det44-in2out",
  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa",
                               "ip4-sv-reassembly-feature"),
};
VNET_FEATURE_INIT (ip4_det44_out2in, static) = {
  .arc_name = "ip4-unicast",
  .node_name = "det44-out2in",
  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa",
                               "ip4-sv-reassembly-feature",
                               "ip4-dhcp-client-detect"),
};
VLIB_PLUGIN_REGISTER () = {
    .version = VPP_BUILD_VER,
    .description = "Deterministic NAT (CGN)",
};
/* *INDENT-ON* */

void
det44_add_del_addr_to_fib (ip4_address_t * addr, u8 p_len, u32 sw_if_index,
			   int is_add)
{
  det44_main_t *dm = &det44_main;
  fib_prefix_t prefix = {
    .fp_len = p_len,
    .fp_proto = FIB_PROTOCOL_IP4,
    .fp_addr = {
		.ip4.as_u32 = addr->as_u32,
		},
  };
  u32 fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);

  if (is_add)
    {
      fib_table_entry_update_one_path (fib_index,
				       &prefix,
				       dm->fib_src_low,
				       (FIB_ENTRY_FLAG_CONNECTED |
					FIB_ENTRY_FLAG_LOCAL |
					FIB_ENTRY_FLAG_EXCLUSIVE),
				       DPO_PROTO_IP4,
				       NULL,
				       sw_if_index,
				       ~0, 1, NULL, FIB_ROUTE_PATH_FLAG_NONE);
    }
  else
    {
      fib_table_entry_delete (fib_index, &prefix, dm->fib_src_low);
    }
}

/**
 * @brief Add/delete deterministic NAT mapping.
 *
 * Create bijective mapping of inside address to outside address and port range
 * pairs, with the purpose of enabling deterministic NAT to reduce logging in
 * CGN deployments.
 *
 * @param in_addr  Inside network address.
 * @param in_plen  Inside network prefix length.
 * @param out_addr Outside network address.
 * @param out_plen Outside network prefix length.
 * @param is_add   If 0 delete, otherwise add.
 */
int
snat_det_add_map (ip4_address_t * in_addr, u8 in_plen,
		  ip4_address_t * out_addr, u8 out_plen, int is_add)
{
  static snat_det_session_t empty_snat_det_session = { 0 };
  det44_main_t *dm = &det44_main;
  ip4_address_t in_cmp, out_cmp;
  det44_interface_t *i;
  snat_det_map_t *mp;
  u8 found = 0;

  in_cmp.as_u32 = in_addr->as_u32 & ip4_main.fib_masks[in_plen];
  out_cmp.as_u32 = out_addr->as_u32 & ip4_main.fib_masks[out_plen];
  vec_foreach (mp, dm->det_maps)
  {
    /* Checking for overlapping addresses to be added here */
    if (mp->in_addr.as_u32 == in_cmp.as_u32 &&
	mp->in_plen == in_plen &&
	mp->out_addr.as_u32 == out_cmp.as_u32 && mp->out_plen == out_plen)
      {
	found = 1;
	break;
      }
  }

  /* If found, don't add again */
  if (found && is_add)
    return VNET_API_ERROR_VALUE_EXIST;

  /* If not found, don't delete */
  if (!found && !is_add)
    return VNET_API_ERROR_NO_SUCH_ENTRY;

  if (is_add)
    {
      pool_get (dm->det_maps, mp);
      clib_memset (mp, 0, sizeof (*mp));
      mp->in_addr.as_u32 = in_cmp.as_u32;
      mp->in_plen = in_plen;
      mp->out_addr.as_u32 = out_cmp.as_u32;
      mp->out_plen = out_plen;
      mp->sharing_ratio = (1 << (32 - in_plen)) / (1 << (32 - out_plen));
      mp->ports_per_host = (65535 - 1023) / mp->sharing_ratio;

      vec_validate_init_empty (mp->sessions,
			       DET44_SES_PER_USER * (1 << (32 - in_plen)) -
			       1, empty_snat_det_session);
    }
  else
    {
      vec_free (mp->sessions);
      vec_del1 (dm->det_maps, mp - dm->det_maps);
    }

  /* Add/del external address range to FIB */
  /* *INDENT-OFF* */
  pool_foreach (i, dm->interfaces)  {
    if (det44_interface_is_inside(i))
      continue;
    det44_add_del_addr_to_fib(out_addr, out_plen, i->sw_if_index, is_add);
    goto out;
  }
  /* *INDENT-ON* */
out:
  return 0;
}

int
det44_set_timeouts (nat_timeouts_t * timeouts)
{
  det44_main_t *dm = &det44_main;
  if (timeouts->udp)
    dm->timeouts.udp = timeouts->udp;
  if (timeouts->tcp.established)
    dm->timeouts.tcp.established = timeouts->tcp.established;
  if (timeouts->tcp.transitory)
    dm->timeouts.tcp.transitory = timeouts->tcp.transitory;
  if (timeouts->icmp)
    dm->timeouts.icmp = timeouts->icmp;
  return 0;
}

nat_timeouts_t
det44_get_timeouts ()
{
  det44_main_t *dm = &det44_main;
  return dm->timeouts;
}

void
det44_reset_timeouts ()
{
  det44_main_t *dm = &det44_main;
  nat_reset_timeouts (&dm->timeouts);
}

int
det44_interface_add_del (u32 sw_if_index, u8 is_inside, int is_del)
{
  det44_main_t *dm = &det44_main;
  det44_interface_t *tmp, *i = 0;
  const char *feature_name;
  int rv;

  // TODO: if plugin is not enabled do not register nodes on interfaces
  // rather make a structure and when enable call is used
  // then register nodes

  /* *INDENT-OFF* */
  pool_foreach (tmp, dm->interfaces)  {
    if (tmp->sw_if_index == sw_if_index)
      {
        i = tmp;
        goto out;
      }
  }
  /* *INDENT-ON* */
out:

  feature_name = is_inside ? "det44-in2out" : "det44-out2in";

  if (is_del)
    {
      if (!i)
	{
	  det44_log_err ("det44 is not enabled on this interface");
	  return VNET_API_ERROR_INVALID_VALUE;
	}

      rv = ip4_sv_reass_enable_disable_with_refcnt (sw_if_index, 0);
      if (rv)
	return rv;

      rv = vnet_feature_enable_disable ("ip4-unicast", feature_name,
					sw_if_index, 1, 0, 0);
      if (rv)
	return rv;

      pool_put (dm->interfaces, i);
    }
  else
    {
      if (i)
	{
	  det44_log_err ("det44 is already enabled on this interface");
	  return VNET_API_ERROR_INVALID_VALUE;
	}

      rv = ip4_sv_reass_enable_disable_with_refcnt (sw_if_index, 1);
      if (rv)
	return rv;

      rv = vnet_feature_enable_disable ("ip4-unicast", feature_name,
					sw_if_index, 1, 0, 0);
      if (rv)
	return rv;

      pool_get (dm->interfaces, i);
      clib_memset (i, 0, sizeof (*i));

      i->sw_if_index = sw_if_index;

      if (is_inside)
	i->flags |= DET44_INTERFACE_FLAG_IS_INSIDE;
      else
	i->flags |= DET44_INTERFACE_FLAG_IS_OUTSIDE;
    }

  if (!is_inside)
    {
      u32 fib_index = fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
							   sw_if_index);
      // add/del outside interface fib to registry
      u8 found = 0;
      det44_fib_t *outside_fib;
      /* *INDENT-OFF* */
      vec_foreach (outside_fib, dm->outside_fibs)
        {
          if (outside_fib->fib_index == fib_index)
            {
              if (!is_del)
                {
                  outside_fib->refcount++;
                }
              else
                {
                  outside_fib->refcount--;
                  if (!outside_fib->refcount)
                    {
                      vec_del1 (dm->outside_fibs,
                                outside_fib - dm->outside_fibs);
                    }
                }
              found = 1;
              break;
            }
        }
      /* *INDENT-ON* */
      if (!is_del && !found)
	{
	  vec_add2 (dm->outside_fibs, outside_fib, 1);
	  outside_fib->fib_index = fib_index;
	  outside_fib->refcount = 1;
	}
      // add/del outside address to FIB
      snat_det_map_t *mp;
      /* *INDENT-OFF* */
      pool_foreach (mp, dm->det_maps)  {
        det44_add_del_addr_to_fib(&mp->out_addr,
                                  mp->out_plen, sw_if_index, !is_del);
      }
      /* *INDENT-ON* */
    }
  return 0;
}

/**
 * @brief The 'det44-expire-walk' process's main loop.
 *
 * Check expire time for active sessions.
 */
static uword
det44_expire_walk_fn (vlib_main_t * vm, vlib_node_runtime_t * rt,
		      vlib_frame_t * f)
{
  det44_main_t *dm = &det44_main;
  snat_det_session_t *ses;
  snat_det_map_t *mp;

  while (1)
    {
      vlib_process_wait_for_event_or_clock (vm, 10.0);
      vlib_process_get_events (vm, NULL);
      u32 now = (u32) vlib_time_now (vm);

      if (!plugin_enabled ())
	{
	  continue;
	}

      pool_foreach (mp, dm->det_maps)
	{
	  vec_foreach (ses, mp->sessions)
	    {
	      // close expired sessions
	      if (ses->in_port && (ses->expire < now))
		{
		  snat_det_ses_close (mp, ses);
		}
	    }
	}
    }
  return 0;
}

void
det44_create_expire_walk_process ()
{
  det44_main_t *dm = &det44_main;

  if (dm->expire_walk_node_index)
    return;

  dm->expire_walk_node_index = vlib_process_create (vlib_get_main (),
						    "det44-expire-walk",
						    det44_expire_walk_fn,
						    16 /* stack_bytes */ );
}

int
det44_plugin_enable (det44_config_t c)
{
  det44_main_t *dm = &det44_main;

  if (plugin_enabled () == 1)
    {
      det44_log_err ("plugin already enabled!");
      return 1;
    }

  det44_log_err ("inside %u, outside %u", c.inside_vrf_id, c.outside_vrf_id);

  dm->outside_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
							     c.outside_vrf_id,
							     dm->fib_src_hi);
  dm->inside_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
							    c.inside_vrf_id,
							    dm->fib_src_hi);

  dm->mss_clamping = 0;
  dm->config = c;
  dm->enabled = 1;

  det44_create_expire_walk_process ();
  return 0;
}

int
det44_plugin_disable ()
{
  det44_main_t *dm = &det44_main;
  det44_interface_t *i, *interfaces;
  snat_det_map_t *mp;
  int rv = 0;

  if (plugin_enabled () == 0)
    {
      det44_log_err ("plugin already disabled!");
      return 1;
    }

  dm->enabled = 0;

  // DET44 cleanup (order dependent)
  // 1) remove interfaces (det44_interface_add_del) removes map ranges from fib
  // 2) free sessions
  // 3) free maps

  interfaces = vec_dup (dm->interfaces);
  vec_foreach (i, interfaces)
  {
    vnet_main_t *vnm = vnet_get_main ();

    if (i->flags & DET44_INTERFACE_FLAG_IS_INSIDE)
      {
	rv = det44_interface_add_del (i->sw_if_index, i->flags, 1);
	if (rv)
	  {
	    det44_log_err ("inside interface %U del failed",
			   unformat_vnet_sw_interface, vnm, i->sw_if_index);
	  }
      }

    if (i->flags & DET44_INTERFACE_FLAG_IS_OUTSIDE)
      {
	rv = det44_interface_add_del (i->sw_if_index, i->flags, 1);
	if (rv)
	  {
	    det44_log_err ("outside interface %U del failed",
			   unformat_vnet_sw_interface, vnm, i->sw_if_index);
	  }

      }
  }
  vec_free (interfaces);

  /* *INDENT-OFF* */
  pool_foreach (mp, dm->det_maps)
   {
    vec_free (mp->sessions);
  }
  /* *INDENT-ON* */

  det44_reset_timeouts ();

  pool_free (dm->interfaces);
  pool_free (dm->det_maps);

  return rv;
}

static void
det44_update_outside_fib (ip4_main_t * im,
			  uword opaque,
			  u32 sw_if_index, u32 new_fib_index,
			  u32 old_fib_index)
{
  det44_main_t *dm = &det44_main;

  det44_fib_t *outside_fib;
  det44_interface_t *i;

  u8 is_add = 1;
  u8 match = 0;

  if (plugin_enabled () == 0)
    return;

  if (new_fib_index == old_fib_index)
    return;

  if (!vec_len (dm->outside_fibs))
    return;

  /* *INDENT-OFF* */
  pool_foreach (i, dm->interfaces)
     {
      if (i->sw_if_index == sw_if_index)
        {
          if (!(det44_interface_is_outside (i)))
	    return;
          match = 1;
        }
    }
  /* *INDENT-ON* */

  if (!match)
    return;

  vec_foreach (outside_fib, dm->outside_fibs)
  {
    if (outside_fib->fib_index == old_fib_index)
      {
	outside_fib->refcount--;
	if (!outside_fib->refcount)
	  vec_del1 (dm->outside_fibs, outside_fib - dm->outside_fibs);
	break;
      }
  }

  vec_foreach (outside_fib, dm->outside_fibs)
  {
    if (outside_fib->fib_index == new_fib_index)
      {
	outside_fib->refcount++;
	is_add = 0;
	break;
      }
  }

  if (is_add)
    {
      vec_add2 (dm->outside_fibs, outside_fib, 1);
      outside_fib->refcount = 1;
      outside_fib->fib_index = new_fib_index;
    }
}

static clib_error_t *
det44_init (vlib_main_t * vm)
{
  det44_main_t *dm = &det44_main;
  ip4_table_bind_callback_t cb;
  vlib_node_t *node;

  clib_memset (dm, 0, sizeof (*dm));

  dm->ip4_main = &ip4_main;
  dm->log_class = vlib_log_register_class ("det44", 0);

  node = vlib_get_node_by_name (vm, (u8 *) "det44-in2out");
  dm->in2out_node_index = node->index;
  node = vlib_get_node_by_name (vm, (u8 *) "det44-out2in");
  dm->out2in_node_index = node->index;

  dm->fib_src_hi = fib_source_allocate ("det44-hi",
					FIB_SOURCE_PRIORITY_HI,
					FIB_SOURCE_BH_SIMPLE);
  dm->fib_src_low = fib_source_allocate ("det44-low",
					 FIB_SOURCE_PRIORITY_LOW,
					 FIB_SOURCE_BH_SIMPLE);

  cb.function = det44_update_outside_fib;
  cb.function_opaque = 0;
  vec_add1 (dm->ip4_main->table_bind_callbacks, cb);

  det44_reset_timeouts ();
  return det44_api_hookup (vm);
}

VLIB_INIT_FUNCTION (det44_init);

u8 *
format_det44_session_state (u8 * s, va_list * args)
{
  u32 i = va_arg (*args, u32);
  u8 *t = 0;

  switch (i)
    {
#define _(v, N, str) case DET44_SESSION_##N: t = (u8 *) str; break;
      foreach_det44_session_state
#undef _
    default:
      t = format (t, "unknown");
    }
  s = format (s, "%s", t);
  return s;
}

u8 *
format_det_map_ses (u8 * s, va_list * args)
{
  snat_det_map_t *det_map = va_arg (*args, snat_det_map_t *);
  ip4_address_t in_addr, out_addr;
  u32 in_offset, out_offset;
  snat_det_session_t *ses = va_arg (*args, snat_det_session_t *);
  u32 *i = va_arg (*args, u32 *);

  u32 user_index = *i / DET44_SES_PER_USER;
  in_addr.as_u32 =
    clib_host_to_net_u32 (clib_net_to_host_u32 (det_map->in_addr.as_u32) +
			  user_index);
  in_offset =
    clib_net_to_host_u32 (in_addr.as_u32) -
    clib_net_to_host_u32 (det_map->in_addr.as_u32);
  out_offset = in_offset / det_map->sharing_ratio;
  out_addr.as_u32 =
    clib_host_to_net_u32 (clib_net_to_host_u32 (det_map->out_addr.as_u32) +
			  out_offset);
  s =
    format (s,
	    "in %U:%d out %U:%d external host %U:%d state: %U expire: %d\n",
	    format_ip4_address, &in_addr, clib_net_to_host_u16 (ses->in_port),
	    format_ip4_address, &out_addr,
	    clib_net_to_host_u16 (ses->out.out_port), format_ip4_address,
	    &ses->out.ext_host_addr,
	    clib_net_to_host_u16 (ses->out.ext_host_port),
	    format_det44_session_state, ses->state, ses->expire);

  return s;
}

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */