child-sa: Remove state to track installation of half the SA again
[strongswan.git] / src / libcharon / sa / ikev2 / tasks / child_rekey.c
1 /*
2 * Copyright (C) 2009-2016 Tobias Brunner
3 * Copyright (C) 2005-2007 Martin Willi
4 * Copyright (C) 2005 Jan Hutter
5 * HSR Hochschule fuer Technik Rapperswil
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * for more details.
16 */
17
18 #include "child_rekey.h"
19
20 #include <daemon.h>
21 #include <encoding/payloads/notify_payload.h>
22 #include <sa/ikev2/tasks/child_create.h>
23 #include <sa/ikev2/tasks/child_delete.h>
24 #include <processing/jobs/rekey_child_sa_job.h>
25 #include <processing/jobs/rekey_ike_sa_job.h>
26
27
28 typedef struct private_child_rekey_t private_child_rekey_t;
29
30 /**
31 * Private members of a child_rekey_t task.
32 */
33 struct private_child_rekey_t {
34
35 /**
36 * Public methods and task_t interface.
37 */
38 child_rekey_t public;
39
40 /**
41 * Assigned IKE_SA.
42 */
43 ike_sa_t *ike_sa;
44
45 /**
46 * Are we the initiator?
47 */
48 bool initiator;
49
50 /**
51 * Protocol of CHILD_SA to rekey
52 */
53 protocol_id_t protocol;
54
55 /**
56 * Inbound SPI of CHILD_SA to rekey
57 */
58 uint32_t spi;
59
60 /**
61 * the CHILD_CREATE task which is reused to simplify rekeying
62 */
63 child_create_t *child_create;
64
65 /**
66 * the CHILD_DELETE task to delete rekeyed CHILD_SA
67 */
68 child_delete_t *child_delete;
69
70 /**
71 * CHILD_SA which gets rekeyed
72 */
73 child_sa_t *child_sa;
74
75 /**
76 * colliding task, may be delete or rekey
77 */
78 task_t *collision;
79
80 /**
81 * Indicate that peer destroyed the redundant child from collision.
82 * This happens if a peer's delete notification for the redundant
83 * child gets processed before the rekey job. If so, we must not
84 * touch the child created in the collision since it points to
85 * memory already freed.
86 */
87 bool other_child_destroyed;
88 };
89
90 /**
91 * Schedule a retry if rekeying temporary failed
92 */
93 static void schedule_delayed_rekey(private_child_rekey_t *this)
94 {
95 uint32_t retry;
96 job_t *job;
97
98 retry = RETRY_INTERVAL - (random() % RETRY_JITTER);
99 job = (job_t*)rekey_child_sa_job_create(
100 this->child_sa->get_protocol(this->child_sa),
101 this->child_sa->get_spi(this->child_sa, TRUE),
102 this->ike_sa->get_my_host(this->ike_sa));
103 DBG1(DBG_IKE, "CHILD_SA rekeying failed, trying again in %d seconds", retry);
104 this->child_sa->set_state(this->child_sa, CHILD_INSTALLED);
105 lib->scheduler->schedule_job(lib->scheduler, job, retry);
106 }
107
108 /**
109 * Implementation of task_t.build for initiator, after rekeying
110 */
111 static status_t build_i_delete(private_child_rekey_t *this, message_t *message)
112 {
113 /* update exchange type to INFORMATIONAL for the delete */
114 message->set_exchange_type(message, INFORMATIONAL);
115
116 return this->child_delete->task.build(&this->child_delete->task, message);
117 }
118
119 /**
120 * Implementation of task_t.process for initiator, after rekeying
121 */
122 static status_t process_i_delete(private_child_rekey_t *this, message_t *message)
123 {
124 return this->child_delete->task.process(&this->child_delete->task, message);
125 }
126
127 /**
128 * find a child using the REKEY_SA notify
129 */
130 static void find_child(private_child_rekey_t *this, message_t *message)
131 {
132 notify_payload_t *notify;
133 protocol_id_t protocol;
134 uint32_t spi;
135
136 notify = message->get_notify(message, REKEY_SA);
137 if (notify)
138 {
139 protocol = notify->get_protocol_id(notify);
140 spi = notify->get_spi(notify);
141
142 if (protocol == PROTO_ESP || protocol == PROTO_AH)
143 {
144 this->child_sa = this->ike_sa->get_child_sa(this->ike_sa, protocol,
145 spi, FALSE);
146 }
147 }
148 }
149
150 METHOD(task_t, build_i, status_t,
151 private_child_rekey_t *this, message_t *message)
152 {
153 notify_payload_t *notify;
154 uint32_t reqid;
155 child_cfg_t *config;
156
157 this->child_sa = this->ike_sa->get_child_sa(this->ike_sa, this->protocol,
158 this->spi, TRUE);
159 if (!this->child_sa)
160 { /* check if it is an outbound CHILD_SA */
161 this->child_sa = this->ike_sa->get_child_sa(this->ike_sa, this->protocol,
162 this->spi, FALSE);
163 if (this->child_sa)
164 {
165 /* we work only with the inbound SPI */
166 this->spi = this->child_sa->get_spi(this->child_sa, TRUE);
167 }
168 }
169 if (!this->child_sa ||
170 (!this->child_create &&
171 this->child_sa->get_state(this->child_sa) != CHILD_INSTALLED) ||
172 (this->child_create &&
173 this->child_sa->get_state(this->child_sa) != CHILD_REKEYING))
174 {
175 /* CHILD_SA is gone or in the wrong state, unable to rekey */
176 message->set_exchange_type(message, EXCHANGE_TYPE_UNDEFINED);
177 return SUCCESS;
178 }
179 config = this->child_sa->get_config(this->child_sa);
180
181
182 /* our CHILD_CREATE task does the hard work for us */
183 if (!this->child_create)
184 {
185 this->child_create = child_create_create(this->ike_sa,
186 config->get_ref(config), TRUE, NULL, NULL);
187 }
188 reqid = this->child_sa->get_reqid(this->child_sa);
189 this->child_create->use_reqid(this->child_create, reqid);
190 this->child_create->use_marks(this->child_create,
191 this->child_sa->get_mark(this->child_sa, TRUE).value,
192 this->child_sa->get_mark(this->child_sa, FALSE).value);
193
194 if (this->child_create->task.build(&this->child_create->task,
195 message) != NEED_MORE)
196 {
197 schedule_delayed_rekey(this);
198 return FAILED;
199 }
200 if (message->get_exchange_type(message) == CREATE_CHILD_SA)
201 {
202 /* don't add the notify if the CHILD_CREATE task changed the exchange */
203 notify = notify_payload_create_from_protocol_and_type(PLV2_NOTIFY,
204 this->protocol, REKEY_SA);
205 notify->set_spi(notify, this->spi);
206 message->add_payload(message, (payload_t*)notify);
207 }
208 this->child_sa->set_state(this->child_sa, CHILD_REKEYING);
209
210 return NEED_MORE;
211 }
212
213 METHOD(task_t, process_r, status_t,
214 private_child_rekey_t *this, message_t *message)
215 {
216 /* let the CHILD_CREATE task process the message */
217 this->child_create->task.process(&this->child_create->task, message);
218
219 find_child(this, message);
220
221 return NEED_MORE;
222 }
223
224 METHOD(task_t, build_r, status_t,
225 private_child_rekey_t *this, message_t *message)
226 {
227 child_cfg_t *config;
228 uint32_t reqid;
229 child_sa_state_t state;
230 child_sa_t *child_sa;
231
232 if (!this->child_sa)
233 {
234 DBG1(DBG_IKE, "unable to rekey, CHILD_SA not found");
235 message->add_notify(message, TRUE, CHILD_SA_NOT_FOUND, chunk_empty);
236 return SUCCESS;
237 }
238 if (this->child_sa->get_state(this->child_sa) == CHILD_DELETING)
239 {
240 DBG1(DBG_IKE, "unable to rekey, we are deleting the CHILD_SA");
241 message->add_notify(message, TRUE, TEMPORARY_FAILURE, chunk_empty);
242 return SUCCESS;
243 }
244
245 /* let the CHILD_CREATE task build the response */
246 reqid = this->child_sa->get_reqid(this->child_sa);
247 this->child_create->use_reqid(this->child_create, reqid);
248 this->child_create->use_marks(this->child_create,
249 this->child_sa->get_mark(this->child_sa, TRUE).value,
250 this->child_sa->get_mark(this->child_sa, FALSE).value);
251 config = this->child_sa->get_config(this->child_sa);
252 this->child_create->set_config(this->child_create, config->get_ref(config));
253 this->child_create->task.build(&this->child_create->task, message);
254
255 state = this->child_sa->get_state(this->child_sa);
256 this->child_sa->set_state(this->child_sa, CHILD_REKEYING);
257
258 if (message->get_payload(message, PLV2_SECURITY_ASSOCIATION) == NULL)
259 { /* rekeying failed, reuse old child */
260 this->child_sa->set_state(this->child_sa, state);
261 return SUCCESS;
262 }
263
264 child_sa = this->child_create->get_child(this->child_create);
265 this->child_sa->set_state(this->child_sa, CHILD_REKEYED);
266 this->child_sa->set_rekey_spi(this->child_sa,
267 child_sa->get_spi(child_sa, FALSE));
268
269 /* invoke rekey hook */
270 charon->bus->child_rekey(charon->bus, this->child_sa,
271 this->child_create->get_child(this->child_create));
272 return SUCCESS;
273 }
274
275 /**
276 * Handle a rekey collision
277 */
278 static child_sa_t *handle_collision(private_child_rekey_t *this)
279 {
280 child_sa_t *to_delete;
281
282 if (this->collision->get_type(this->collision) == TASK_CHILD_REKEY)
283 {
284 chunk_t this_nonce, other_nonce;
285 private_child_rekey_t *other = (private_child_rekey_t*)this->collision;
286
287 this_nonce = this->child_create->get_lower_nonce(this->child_create);
288 other_nonce = other->child_create->get_lower_nonce(other->child_create);
289
290 /* if we have the lower nonce, delete rekeyed SA. If not, delete
291 * the redundant. */
292 if (memcmp(this_nonce.ptr, other_nonce.ptr,
293 min(this_nonce.len, other_nonce.len)) > 0)
294 {
295 child_sa_t *child_sa;
296
297 DBG1(DBG_IKE, "CHILD_SA rekey collision won, deleting old child");
298 to_delete = this->child_sa;
299 /* don't touch child other created, it has already been deleted */
300 if (!this->other_child_destroyed)
301 {
302 /* disable close action and updown event for redundant child */
303 child_sa = other->child_create->get_child(other->child_create);
304 if (child_sa)
305 {
306 child_sa->set_close_action(child_sa, ACTION_NONE);
307 if (child_sa->get_state(child_sa) != CHILD_REKEYED)
308 {
309 child_sa->set_state(child_sa, CHILD_REKEYED);
310 }
311 }
312 }
313 }
314 else
315 {
316 DBG1(DBG_IKE, "CHILD_SA rekey collision lost, "
317 "deleting rekeyed child");
318 to_delete = this->child_create->get_child(this->child_create);
319 }
320 }
321 else
322 { /* CHILD_DELETE */
323 child_delete_t *del = (child_delete_t*)this->collision;
324
325 /* we didn't had a chance to compare the nonces, so we delete
326 * the CHILD_SA the other is not deleting. */
327 if (del->get_child(del) != this->child_sa)
328 {
329 DBG1(DBG_IKE, "CHILD_SA rekey/delete collision, "
330 "deleting rekeyed child");
331 to_delete = this->child_sa;
332 }
333 else
334 {
335 DBG1(DBG_IKE, "CHILD_SA rekey/delete collision, "
336 "deleting redundant child");
337 to_delete = this->child_create->get_child(this->child_create);
338 }
339 }
340 return to_delete;
341 }
342
343 METHOD(task_t, process_i, status_t,
344 private_child_rekey_t *this, message_t *message)
345 {
346 protocol_id_t protocol;
347 uint32_t spi;
348 child_sa_t *to_delete;
349
350 if (message->get_notify(message, NO_ADDITIONAL_SAS))
351 {
352 DBG1(DBG_IKE, "peer seems to not support CHILD_SA rekeying, "
353 "starting reauthentication");
354 this->child_sa->set_state(this->child_sa, CHILD_INSTALLED);
355 lib->processor->queue_job(lib->processor,
356 (job_t*)rekey_ike_sa_job_create(
357 this->ike_sa->get_id(this->ike_sa), TRUE));
358 return SUCCESS;
359 }
360 if (message->get_notify(message, CHILD_SA_NOT_FOUND))
361 {
362 child_cfg_t *child_cfg;
363 uint32_t reqid;
364
365 if (this->collision &&
366 this->collision->get_type(this->collision) == TASK_CHILD_DELETE)
367 { /* ignore this error if we already deleted the CHILD_SA on the
368 * peer's behalf (could happen if the other peer does not detect
369 * the collision and did not respond with TEMPORARY_FAILURE) */
370 return SUCCESS;
371 }
372 DBG1(DBG_IKE, "peer didn't find the CHILD_SA we tried to rekey");
373 /* FIXME: according to RFC 7296 we should only create a new CHILD_SA if
374 * it does not exist yet, we currently have no good way of checking for
375 * that (we could go by name, but that might be tricky e.g. due to
376 * narrowing) */
377 spi = this->child_sa->get_spi(this->child_sa, TRUE);
378 reqid = this->child_sa->get_reqid(this->child_sa);
379 protocol = this->child_sa->get_protocol(this->child_sa);
380 child_cfg = this->child_sa->get_config(this->child_sa);
381 child_cfg->get_ref(child_cfg);
382 charon->bus->child_updown(charon->bus, this->child_sa, FALSE);
383 this->ike_sa->destroy_child_sa(this->ike_sa, protocol, spi);
384 return this->ike_sa->initiate(this->ike_sa,
385 child_cfg->get_ref(child_cfg), reqid,
386 NULL, NULL);
387 }
388
389 if (this->child_create->task.process(&this->child_create->task,
390 message) == NEED_MORE)
391 {
392 /* bad DH group while rekeying, retry, or failure requiring deletion */
393 return NEED_MORE;
394 }
395 if (message->get_payload(message, PLV2_SECURITY_ASSOCIATION) == NULL)
396 {
397 /* establishing new child failed, reuse old and try again. but not when
398 * we received a delete in the meantime */
399 if (!this->collision ||
400 this->collision->get_type(this->collision) != TASK_CHILD_DELETE)
401 {
402 schedule_delayed_rekey(this);
403 }
404 return SUCCESS;
405 }
406
407 /* check for rekey collisions */
408 if (this->collision)
409 {
410 to_delete = handle_collision(this);
411 }
412 else
413 {
414 to_delete = this->child_sa;
415 }
416
417 if (to_delete != this->child_create->get_child(this->child_create))
418 { /* invoke rekey hook if rekeying successful */
419 charon->bus->child_rekey(charon->bus, this->child_sa,
420 this->child_create->get_child(this->child_create));
421 }
422
423 if (to_delete == NULL)
424 {
425 return SUCCESS;
426 }
427 /* disable updown event for redundant CHILD_SA */
428 if (to_delete->get_state(to_delete) != CHILD_REKEYED)
429 {
430 to_delete->set_state(to_delete, CHILD_REKEYED);
431 }
432 spi = to_delete->get_spi(to_delete, TRUE);
433 protocol = to_delete->get_protocol(to_delete);
434
435 /* rekeying done, delete the obsolete CHILD_SA using a subtask */
436 this->child_delete = child_delete_create(this->ike_sa, protocol, spi, FALSE);
437 this->public.task.build = (status_t(*)(task_t*,message_t*))build_i_delete;
438 this->public.task.process = (status_t(*)(task_t*,message_t*))process_i_delete;
439
440 return NEED_MORE;
441 }
442
443 METHOD(task_t, get_type, task_type_t,
444 private_child_rekey_t *this)
445 {
446 return TASK_CHILD_REKEY;
447 }
448
449 METHOD(child_rekey_t, is_redundant, bool,
450 private_child_rekey_t *this, child_sa_t *child)
451 {
452 if (this->collision &&
453 this->collision->get_type(this->collision) == TASK_CHILD_REKEY)
454 {
455 private_child_rekey_t *rekey = (private_child_rekey_t*)this->collision;
456 return child == rekey->child_create->get_child(rekey->child_create);
457 }
458 return FALSE;
459 }
460
461 METHOD(child_rekey_t, collide, void,
462 private_child_rekey_t *this, task_t *other)
463 {
464 /* the task manager only detects exchange collision, but not if
465 * the collision is for the same child. we check it here. */
466 if (other->get_type(other) == TASK_CHILD_REKEY)
467 {
468 private_child_rekey_t *rekey = (private_child_rekey_t*)other;
469 child_sa_t *other_child;
470
471 if (rekey->child_sa != this->child_sa)
472 { /* not the same child => no collision */
473 other->destroy(other);
474 return;
475 }
476 /* ignore passive tasks that did not successfully create a CHILD_SA */
477 other_child = rekey->child_create->get_child(rekey->child_create);
478 if (!other_child ||
479 other_child->get_state(other_child) != CHILD_INSTALLED)
480 {
481 other->destroy(other);
482 return;
483 }
484 }
485 else if (other->get_type(other) == TASK_CHILD_DELETE)
486 {
487 child_delete_t *del = (child_delete_t*)other;
488 if (is_redundant(this, del->get_child(del)))
489 {
490 this->other_child_destroyed = TRUE;
491 other->destroy(other);
492 return;
493 }
494 if (del->get_child(del) != this->child_sa)
495 {
496 /* not the same child => no collision */
497 other->destroy(other);
498 return;
499 }
500 }
501 else
502 {
503 /* any other task is not critical for collisions, ignore */
504 other->destroy(other);
505 return;
506 }
507 DBG1(DBG_IKE, "detected %N collision with %N", task_type_names,
508 TASK_CHILD_REKEY, task_type_names, other->get_type(other));
509 DESTROY_IF(this->collision);
510 this->collision = other;
511 }
512
513 METHOD(task_t, migrate, void,
514 private_child_rekey_t *this, ike_sa_t *ike_sa)
515 {
516 if (this->child_create)
517 {
518 this->child_create->task.migrate(&this->child_create->task, ike_sa);
519 }
520 if (this->child_delete)
521 {
522 this->child_delete->task.migrate(&this->child_delete->task, ike_sa);
523 }
524 DESTROY_IF(this->collision);
525
526 this->ike_sa = ike_sa;
527 this->collision = NULL;
528 }
529
530 METHOD(task_t, destroy, void,
531 private_child_rekey_t *this)
532 {
533 if (this->child_create)
534 {
535 this->child_create->task.destroy(&this->child_create->task);
536 }
537 if (this->child_delete)
538 {
539 this->child_delete->task.destroy(&this->child_delete->task);
540 }
541 DESTROY_IF(this->collision);
542 free(this);
543 }
544
545 /*
546 * Described in header.
547 */
548 child_rekey_t *child_rekey_create(ike_sa_t *ike_sa, protocol_id_t protocol,
549 uint32_t spi)
550 {
551 private_child_rekey_t *this;
552
553 INIT(this,
554 .public = {
555 .task = {
556 .get_type = _get_type,
557 .migrate = _migrate,
558 .destroy = _destroy,
559 },
560 .is_redundant = _is_redundant,
561 .collide = _collide,
562 },
563 .ike_sa = ike_sa,
564 .protocol = protocol,
565 .spi = spi,
566 );
567
568 if (protocol != PROTO_NONE)
569 {
570 this->public.task.build = _build_i;
571 this->public.task.process = _process_i;
572 this->initiator = TRUE;
573 this->child_create = NULL;
574 }
575 else
576 {
577 this->public.task.build = _build_r;
578 this->public.task.process = _process_r;
579 this->initiator = FALSE;
580 this->child_create = child_create_create(ike_sa, NULL, TRUE, NULL, NULL);
581 }
582
583 return &this->public;
584 }