aboutsummaryrefslogtreecommitdiffstats
path: root/src/vnet/ipsec/ipsec_sa.c
blob: 295323b8f7e9eb3b680ef660ea57cdfdc18b63c8 (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
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
/*
 * Copyright (c) 2015 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.
 */

#include <vnet/ipsec/ipsec.h>
#include <vnet/ipsec/esp.h>
#include <vnet/udp/udp_local.h>
#include <vnet/fib/fib_table.h>
#include <vnet/fib/fib_entry_track.h>
#include <vnet/ipsec/ipsec_tun.h>

/**
 * @brief
 * SA packet & bytes counters
 */
vlib_combined_counter_main_t ipsec_sa_counters = {
  .name = "SA",
  .stat_segment_name = "/net/ipsec/sa",
};
vlib_simple_counter_main_t ipsec_sa_lost_counters = {
  .name = "SA-lost",
  .stat_segment_name = "/net/ipsec/sa/lost",
};

ipsec_sa_t *ipsec_sa_pool;

static clib_error_t *
ipsec_call_add_del_callbacks (ipsec_main_t * im, ipsec_sa_t * sa,
			      u32 sa_index, int is_add)
{
  ipsec_ah_backend_t *ab;
  ipsec_esp_backend_t *eb;
  switch (sa->protocol)
    {
    case IPSEC_PROTOCOL_AH:
      ab = pool_elt_at_index (im->ah_backends, im->ah_current_backend);
      if (ab->add_del_sa_sess_cb)
	return ab->add_del_sa_sess_cb (sa_index, is_add);
      break;
    case IPSEC_PROTOCOL_ESP:
      eb = pool_elt_at_index (im->esp_backends, im->esp_current_backend);
      if (eb->add_del_sa_sess_cb)
	return eb->add_del_sa_sess_cb (sa_index, is_add);
      break;
    }
  return 0;
}

void
ipsec_mk_key (ipsec_key_t * key, const u8 * data, u8 len)
{
  memset (key, 0, sizeof (*key));

  if (len > sizeof (key->data))
    key->len = sizeof (key->data);
  else
    key->len = len;

  memcpy (key->data, data, key->len);
}

/**
 * 'stack' (resolve the recursion for) the SA tunnel destination
 */
static void
ipsec_sa_stack (ipsec_sa_t * sa)
{
  ipsec_main_t *im = &ipsec_main;
  dpo_id_t tmp = DPO_INVALID;

  tunnel_contribute_forwarding (&sa->tunnel, &tmp);

  if (IPSEC_PROTOCOL_AH == sa->protocol)
    dpo_stack_from_node ((ipsec_sa_is_set_IS_TUNNEL_V6 (sa) ?
			  im->ah6_encrypt_node_index :
			  im->ah4_encrypt_node_index), &sa->dpo, &tmp);
  else
    dpo_stack_from_node ((ipsec_sa_is_set_IS_TUNNEL_V6 (sa) ?
			  im->esp6_encrypt_node_index :
			  im->esp4_encrypt_node_index), &sa->dpo, &tmp);
  dpo_reset (&tmp);
}

void
ipsec_sa_set_crypto_alg (ipsec_sa_t * sa, ipsec_crypto_alg_t crypto_alg)
{
  ipsec_main_t *im = &ipsec_main;
  sa->crypto_alg = crypto_alg;
  sa->crypto_iv_size = im->crypto_algs[crypto_alg].iv_size;
  sa->esp_block_align = clib_max (4, im->crypto_algs[crypto_alg].block_align);
  sa->sync_op_data.crypto_enc_op_id = im->crypto_algs[crypto_alg].enc_op_id;
  sa->sync_op_data.crypto_dec_op_id = im->crypto_algs[crypto_alg].dec_op_id;
  sa->crypto_calg = im->crypto_algs[crypto_alg].alg;
  ASSERT (sa->crypto_iv_size <= ESP_MAX_IV_SIZE);
  ASSERT (sa->esp_block_align <= ESP_MAX_BLOCK_SIZE);
  if (IPSEC_CRYPTO_ALG_IS_GCM (crypto_alg) ||
      IPSEC_CRYPTO_ALG_CTR_AEAD_OTHERS (crypto_alg))
    {
      sa->integ_icv_size = im->crypto_algs[crypto_alg].icv_size;
      ipsec_sa_set_IS_CTR (sa);
      ipsec_sa_set_IS_AEAD (sa);
    }
  else if (IPSEC_CRYPTO_ALG_IS_CTR (crypto_alg))
    {
      ipsec_sa_set_IS_CTR (sa);
    }
}

void
ipsec_sa_set_integ_alg (ipsec_sa_t * sa, ipsec_integ_alg_t integ_alg)
{
  ipsec_main_t *im = &ipsec_main;
  sa->integ_alg = integ_alg;
  sa->integ_icv_size = im->integ_algs[integ_alg].icv_size;
  sa->sync_op_data.integ_op_id = im->integ_algs[integ_alg].op_id;
  sa->integ_calg = im->integ_algs[integ_alg].alg;
  ASSERT (sa->integ_icv_size <= ESP_MAX_ICV_SIZE);
}

void
ipsec_sa_set_async_op_ids (ipsec_sa_t * sa)
{
  /* *INDENT-OFF* */
  if (ipsec_sa_is_set_USE_ESN (sa))
    {
#define _(n, s, k) \
  if( sa->sync_op_data.crypto_enc_op_id == VNET_CRYPTO_OP_##n##_ENC ) \
    sa->async_op_data.crypto_async_enc_op_id = \
      VNET_CRYPTO_OP_##n##_TAG16_AAD12_ENC; \
  if( sa->sync_op_data.crypto_dec_op_id == VNET_CRYPTO_OP_##n##_DEC ) \
    sa->async_op_data.crypto_async_dec_op_id = \
      VNET_CRYPTO_OP_##n##_TAG16_AAD12_DEC;
    foreach_crypto_aead_alg
#undef _
    }
  else
    {
#define _(n, s, k) \
  if( sa->sync_op_data.crypto_enc_op_id == VNET_CRYPTO_OP_##n##_ENC ) \
    sa->async_op_data.crypto_async_enc_op_id = \
      VNET_CRYPTO_OP_##n##_TAG16_AAD8_ENC; \
  if( sa->sync_op_data.crypto_dec_op_id == VNET_CRYPTO_OP_##n##_DEC ) \
    sa->async_op_data.crypto_async_dec_op_id = \
      VNET_CRYPTO_OP_##n##_TAG16_AAD8_DEC;
    foreach_crypto_aead_alg
#undef _
    }

#define _(c, h, s, k ,d) \
  if( sa->sync_op_data.crypto_enc_op_id == VNET_CRYPTO_OP_##c##_ENC && \
      sa->sync_op_data.integ_op_id == VNET_CRYPTO_OP_##h##_HMAC) \
    sa->async_op_data.crypto_async_enc_op_id = \
      VNET_CRYPTO_OP_##c##_##h##_TAG##d##_ENC; \
  if( sa->sync_op_data.crypto_dec_op_id == VNET_CRYPTO_OP_##c##_DEC && \
      sa->sync_op_data.integ_op_id == VNET_CRYPTO_OP_##h##_HMAC) \
    sa->async_op_data.crypto_async_dec_op_id = \
      VNET_CRYPTO_OP_##c##_##h##_TAG##d##_DEC;
  foreach_crypto_link_async_alg
#undef _
  /* *INDENT-ON* */
}

int
ipsec_sa_update (u32 id, u16 src_port, u16 dst_port, const tunnel_t *tun,
		 bool is_tun)
{
  ipsec_main_t *im = &ipsec_main;
  ipsec_sa_t *sa;
  u32 sa_index;
  uword *p;
  int rv;

  p = hash_get (im->sa_index_by_sa_id, id);
  if (!p)
    return VNET_API_ERROR_NO_SUCH_ENTRY;

  sa = ipsec_sa_get (p[0]);
  sa_index = sa - ipsec_sa_pool;

  if (is_tun && ipsec_sa_is_set_IS_TUNNEL (sa) &&
      (ip_address_cmp (&tun->t_src, &sa->tunnel.t_src) != 0 ||
       ip_address_cmp (&tun->t_dst, &sa->tunnel.t_dst) != 0))
    {
      /* if the source IP is updated for an inbound SA under a tunnel protect,
       we need to update the tun_protect DB with the new src IP */
      if (ipsec_sa_is_set_IS_INBOUND (sa) &&
	  ip_address_cmp (&tun->t_src, &sa->tunnel.t_src) != 0 &&
	  !ip46_address_is_zero (&tun->t_src.ip))
	{
	  if (ip46_address_is_ip4 (&sa->tunnel.t_src.ip))
	    {
	      ipsec4_tunnel_kv_t old_key, new_key;
	      clib_bihash_kv_8_16_t res,
		*bkey = (clib_bihash_kv_8_16_t *) &old_key;

	      ipsec4_tunnel_mk_key (&old_key, &sa->tunnel.t_src.ip.ip4,
				    clib_host_to_net_u32 (sa->spi));
	      ipsec4_tunnel_mk_key (&new_key, &tun->t_src.ip.ip4,
				    clib_host_to_net_u32 (sa->spi));

	      if (!clib_bihash_search_8_16 (&im->tun4_protect_by_key, bkey,
					    &res))
		{
		  clib_bihash_add_del_8_16 (&im->tun4_protect_by_key, &res, 0);
		  res.key = new_key.key;
		  clib_bihash_add_del_8_16 (&im->tun4_protect_by_key, &res, 1);
		}
	    }
	  else
	    {
	      ipsec6_tunnel_kv_t old_key = {
          .key = {
            .remote_ip =  sa->tunnel.t_src.ip.ip6,
            .spi = clib_host_to_net_u32 (sa->spi),
          },
        }, new_key = {
          .key = {
            .remote_ip = tun->t_src.ip.ip6,
            .spi = clib_host_to_net_u32 (sa->spi),
          }};
	      clib_bihash_kv_24_16_t res,
		*bkey = (clib_bihash_kv_24_16_t *) &old_key;

	      if (!clib_bihash_search_24_16 (&im->tun6_protect_by_key, bkey,
					     &res))
		{
		  clib_bihash_add_del_24_16 (&im->tun6_protect_by_key, &res,
					     0);
		  clib_memcpy (&res.key, &new_key.key, 3);
		  clib_bihash_add_del_24_16 (&im->tun6_protect_by_key, &res,
					     1);
		}
	    }
	}
      tunnel_unresolve (&sa->tunnel);
      tunnel_copy (tun, &sa->tunnel);
      if (!ipsec_sa_is_set_IS_INBOUND (sa))
	{
	  dpo_reset (&sa->dpo);

	  sa->tunnel_flags = sa->tunnel.t_encap_decap_flags;

	  rv = tunnel_resolve (&sa->tunnel, FIB_NODE_TYPE_IPSEC_SA, sa_index);

	  if (rv)
	    {
	      hash_unset (im->sa_index_by_sa_id, sa->id);
	      pool_put (ipsec_sa_pool, sa);
	      return rv;
	    }
	  ipsec_sa_stack (sa);
	  /* generate header templates */
	  if (ipsec_sa_is_set_IS_TUNNEL_V6 (sa))
	    {
	      tunnel_build_v6_hdr (&sa->tunnel,
				   (ipsec_sa_is_set_UDP_ENCAP (sa) ?
					    IP_PROTOCOL_UDP :
					    IP_PROTOCOL_IPSEC_ESP),
				   &sa->ip6_hdr);
	    }
	  else
	    {
	      tunnel_build_v4_hdr (&sa->tunnel,
				   (ipsec_sa_is_set_UDP_ENCAP (sa) ?
					    IP_PROTOCOL_UDP :
					    IP_PROTOCOL_IPSEC_ESP),
				   &sa->ip4_hdr);
	    }
	}
    }

  if (ipsec_sa_is_set_UDP_ENCAP (sa))
    {
      if (dst_port != IPSEC_UDP_PORT_NONE &&
	  dst_port != clib_net_to_host_u16 (sa->udp_hdr.dst_port))
	{
	  if (ipsec_sa_is_set_IS_INBOUND (sa))
	    {
	      ipsec_unregister_udp_port (
		clib_net_to_host_u16 (sa->udp_hdr.dst_port),
		!ipsec_sa_is_set_IS_TUNNEL_V6 (sa));
	      ipsec_register_udp_port (dst_port,
				       !ipsec_sa_is_set_IS_TUNNEL_V6 (sa));
	    }
	  sa->udp_hdr.dst_port = clib_host_to_net_u16 (dst_port);
	}
      if (src_port != IPSEC_UDP_PORT_NONE &&
	  src_port != clib_net_to_host_u16 (sa->udp_hdr.src_port))
	sa->udp_hdr.src_port = clib_host_to_net_u16 (src_port);
    }
  return (0);
}

int
ipsec_sa_add_and_lock (u32 id, u32 spi, ipsec_protocol_t proto,
		       ipsec_crypto_alg_t crypto_alg, const ipsec_key_t *ck,
		       ipsec_integ_alg_t integ_alg, const ipsec_key_t *ik,
		       ipsec_sa_flags_t flags, u32 salt, u16 src_port,
		       u16 dst_port, const tunnel_t *tun, u32 *sa_out_index)
{
  vlib_main_t *vm = vlib_get_main ();
  ipsec_main_t *im = &ipsec_main;
  clib_error_t *err;
  ipsec_sa_t *sa;
  u32 sa_index;
  uword *p;
  int rv;

  p = hash_get (im->sa_index_by_sa_id, id);
  if (p)
    return VNET_API_ERROR_ENTRY_ALREADY_EXISTS;

  pool_get_aligned_zero (ipsec_sa_pool, sa, CLIB_CACHE_LINE_BYTES);

  fib_node_init (&sa->node, FIB_NODE_TYPE_IPSEC_SA);
  fib_node_lock (&sa->node);
  sa_index = sa - ipsec_sa_pool;

  vlib_validate_combined_counter (&ipsec_sa_counters, sa_index);
  vlib_zero_combined_counter (&ipsec_sa_counters, sa_index);
  vlib_validate_simple_counter (&ipsec_sa_lost_counters, sa_index);
  vlib_zero_simple_counter (&ipsec_sa_lost_counters, sa_index);

  tunnel_copy (tun, &sa->tunnel);
  sa->id = id;
  sa->spi = spi;
  sa->stat_index = sa_index;
  sa->protocol = proto;
  sa->flags = flags;
  sa->salt = salt;
  sa->thread_index = (vlib_num_workers ()) ? ~0 : 0;
  if (integ_alg != IPSEC_INTEG_ALG_NONE)
    {
      ipsec_sa_set_integ_alg (sa, integ_alg);
      clib_memcpy (&sa->integ_key, ik, sizeof (sa->integ_key));
    }
  ipsec_sa_set_crypto_alg (sa, crypto_alg);
  ipsec_sa_set_async_op_ids (sa);

  clib_memcpy (&sa->crypto_key, ck, sizeof (sa->crypto_key));

  sa->crypto_key_index = vnet_crypto_key_add (vm,
					      im->crypto_algs[crypto_alg].alg,
					      (u8 *) ck->data, ck->len);
  if (~0 == sa->crypto_key_index)
    {
      pool_put (ipsec_sa_pool, sa);
      return VNET_API_ERROR_KEY_LENGTH;
    }

  if (integ_alg != IPSEC_INTEG_ALG_NONE)
    {
      sa->integ_key_index = vnet_crypto_key_add (vm,
						 im->
						 integ_algs[integ_alg].alg,
						 (u8 *) ik->data, ik->len);
      if (~0 == sa->integ_key_index)
	{
	  pool_put (ipsec_sa_pool, sa);
	  return VNET_API_ERROR_KEY_LENGTH;
	}
    }

  if (sa->async_op_data.crypto_async_enc_op_id &&
      !ipsec_sa_is_set_IS_AEAD (sa))
    {				//AES-CBC & HMAC
      sa->async_op_data.linked_key_index =
	vnet_crypto_key_add_linked (vm, sa->crypto_key_index,
				    sa->integ_key_index);
    }

  if (im->async_mode)
    sa->crypto_op_data = sa->async_op_data.data;
  else
    {
      if (ipsec_sa_is_set_IS_ASYNC (sa))
	{
	  vnet_crypto_request_async_mode (1);
	  sa->crypto_op_data = sa->async_op_data.data;
	}
      else
	sa->crypto_op_data = sa->sync_op_data.data;
    }

  err = ipsec_check_support_cb (im, sa);
  if (err)
    {
      clib_warning ("%s", err->what);
      pool_put (ipsec_sa_pool, sa);
      return VNET_API_ERROR_UNIMPLEMENTED;
    }

  err = ipsec_call_add_del_callbacks (im, sa, sa_index, 1);
  if (err)
    {
      pool_put (ipsec_sa_pool, sa);
      return VNET_API_ERROR_SYSCALL_ERROR_1;
    }

  if (ipsec_sa_is_set_IS_TUNNEL (sa) &&
      AF_IP6 == ip_addr_version (&tun->t_src))
    ipsec_sa_set_IS_TUNNEL_V6 (sa);

  if (ipsec_sa_is_set_IS_TUNNEL (sa) && !ipsec_sa_is_set_IS_INBOUND (sa))
    {
      sa->tunnel_flags = sa->tunnel.t_encap_decap_flags;

      rv = tunnel_resolve (&sa->tunnel, FIB_NODE_TYPE_IPSEC_SA, sa_index);

      if (rv)
	{
	  pool_put (ipsec_sa_pool, sa);
	  return rv;
	}
      ipsec_sa_stack (sa);

      /* generate header templates */
      if (ipsec_sa_is_set_IS_TUNNEL_V6 (sa))
	{
	  tunnel_build_v6_hdr (&sa->tunnel,
			       (ipsec_sa_is_set_UDP_ENCAP (sa) ?
				  IP_PROTOCOL_UDP :
				  IP_PROTOCOL_IPSEC_ESP),
			       &sa->ip6_hdr);
	}
      else
	{
	  tunnel_build_v4_hdr (&sa->tunnel,
			       (ipsec_sa_is_set_UDP_ENCAP (sa) ?
				  IP_PROTOCOL_UDP :
				  IP_PROTOCOL_IPSEC_ESP),
			       &sa->ip4_hdr);
	}
    }

  if (ipsec_sa_is_set_UDP_ENCAP (sa))
    {
      if (dst_port == IPSEC_UDP_PORT_NONE)
	sa->udp_hdr.dst_port = clib_host_to_net_u16 (UDP_DST_PORT_ipsec);
      else
	sa->udp_hdr.dst_port = clib_host_to_net_u16 (dst_port);

      if (src_port == IPSEC_UDP_PORT_NONE)
	sa->udp_hdr.src_port = clib_host_to_net_u16 (UDP_DST_PORT_ipsec);
      else
	sa->udp_hdr.src_port = clib_host_to_net_u16 (src_port);

      if (ipsec_sa_is_set_IS_INBOUND (sa))
	ipsec_register_udp_port (clib_host_to_net_u16 (sa->udp_hdr.dst_port),
				 !ipsec_sa_is_set_IS_TUNNEL_V6 (sa));
    }

  hash_set (im->sa_index_by_sa_id, sa->id, sa_index);

  if (sa_out_index)
    *sa_out_index = sa_index;

  return (0);
}

static void
ipsec_sa_del (ipsec_sa_t * sa)
{
  vlib_main_t *vm = vlib_get_main ();
  ipsec_main_t *im = &ipsec_main;
  u32 sa_index;

  sa_index = sa - ipsec_sa_pool;
  hash_unset (im->sa_index_by_sa_id, sa->id);
  tunnel_unresolve (&sa->tunnel);

  /* no recovery possible when deleting an SA */
  (void) ipsec_call_add_del_callbacks (im, sa, sa_index, 0);

  if (ipsec_sa_is_set_IS_ASYNC (sa))
    vnet_crypto_request_async_mode (0);
  if (ipsec_sa_is_set_UDP_ENCAP (sa) && ipsec_sa_is_set_IS_INBOUND (sa))
    ipsec_unregister_udp_port (clib_net_to_host_u16 (sa->udp_hdr.dst_port),
			       !ipsec_sa_is_set_IS_TUNNEL_V6 (sa));

  if (ipsec_sa_is_set_IS_TUNNEL (sa) && !ipsec_sa_is_set_IS_INBOUND (sa))
    dpo_reset (&sa->dpo);
  vnet_crypto_key_del (vm, sa->crypto_key_index);
  if (sa->integ_alg != IPSEC_INTEG_ALG_NONE)
    vnet_crypto_key_del (vm, sa->integ_key_index);
  pool_put (ipsec_sa_pool, sa);
}

void
ipsec_sa_unlock (index_t sai)
{
  ipsec_sa_t *sa;

  if (INDEX_INVALID == sai)
    return;

  sa = ipsec_sa_get (sai);

  fib_node_unlock (&sa->node);
}

void
ipsec_sa_lock (index_t sai)
{
  ipsec_sa_t *sa;

  if (INDEX_INVALID == sai)
    return;

  sa = ipsec_sa_get (sai);

  fib_node_lock (&sa->node);
}

index_t
ipsec_sa_find_and_lock (u32 id)
{
  ipsec_main_t *im = &ipsec_main;
  ipsec_sa_t *sa;
  uword *p;

  p = hash_get (im->sa_index_by_sa_id, id);

  if (!p)
    return INDEX_INVALID;

  sa = ipsec_sa_get (p[0]);

  fib_node_lock (&sa->node);

  return (p[0]);
}

int
ipsec_sa_unlock_id (u32 id)
{
  ipsec_main_t *im = &ipsec_main;
  uword *p;

  p = hash_get (im->sa_index_by_sa_id, id);

  if (!p)
    return VNET_API_ERROR_NO_SUCH_ENTRY;

  ipsec_sa_unlock (p[0]);

  return (0);
}

void
ipsec_sa_clear (index_t sai)
{
  vlib_zero_combined_counter (&ipsec_sa_counters, sai);
  vlib_zero_simple_counter (&ipsec_sa_lost_counters, sai);
}

void
ipsec_sa_walk (ipsec_sa_walk_cb_t cb, void *ctx)
{
  ipsec_sa_t *sa;

  /* *INDENT-OFF* */
  pool_foreach (sa, ipsec_sa_pool)
    {
      if (WALK_CONTINUE != cb (sa, ctx))
	break;
    }
  /* *INDENT-ON* */
}

/**
 * Function definition to get a FIB node from its index
 */
static fib_node_t *
ipsec_sa_fib_node_get (fib_node_index_t index)
{
  ipsec_sa_t *sa;

  sa = ipsec_sa_get (index);

  return (&sa->node);
}

static ipsec_sa_t *
ipsec_sa_from_fib_node (fib_node_t * node)
{
  ASSERT (FIB_NODE_TYPE_IPSEC_SA == node->fn_type);
  return ((ipsec_sa_t *) (((char *) node) -
			  STRUCT_OFFSET_OF (ipsec_sa_t, node)));

}

/**
 * Function definition to inform the FIB node that its last lock has gone.
 */
static void
ipsec_sa_last_lock_gone (fib_node_t * node)
{
  /*
   * The ipsec SA is a root of the graph. As such
   * it never has children and thus is never locked.
   */
  ipsec_sa_del (ipsec_sa_from_fib_node (node));
}

/**
 * Function definition to backwalk a FIB node
 */
static fib_node_back_walk_rc_t
ipsec_sa_back_walk (fib_node_t * node, fib_node_back_walk_ctx_t * ctx)
{
  ipsec_sa_stack (ipsec_sa_from_fib_node (node));

  return (FIB_NODE_BACK_WALK_CONTINUE);
}

/*
 * Virtual function table registered by SAs
 * for participation in the FIB object graph.
 */
const static fib_node_vft_t ipsec_sa_vft = {
  .fnv_get = ipsec_sa_fib_node_get,
  .fnv_last_lock = ipsec_sa_last_lock_gone,
  .fnv_back_walk = ipsec_sa_back_walk,
};

/* force inclusion from application's main.c */
clib_error_t *
ipsec_sa_interface_init (vlib_main_t * vm)
{
  fib_node_register_type (FIB_NODE_TYPE_IPSEC_SA, &ipsec_sa_vft);

  return 0;
}

VLIB_INIT_FUNCTION (ipsec_sa_interface_init);

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