ike-rekey: Return TEMPORARY_FAILURE when concurrently creating a CHILD_SA
[strongswan.git] / src / libcharon / sa / ikev2 / tasks / ike_rekey.c
1 /*
2 * Copyright (C) 2015-2016 Tobias Brunner
3 * Copyright (C) 2005-2008 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 "ike_rekey.h"
19
20 #include <daemon.h>
21 #include <encoding/payloads/notify_payload.h>
22 #include <sa/ikev2/tasks/ike_init.h>
23 #include <sa/ikev2/tasks/ike_delete.h>
24 #include <processing/jobs/delete_ike_sa_job.h>
25 #include <processing/jobs/rekey_ike_sa_job.h>
26 #include <processing/jobs/initiate_tasks_job.h>
27
28
29 typedef struct private_ike_rekey_t private_ike_rekey_t;
30
31 /**
32 * Private members of a ike_rekey_t task.
33 */
34 struct private_ike_rekey_t {
35
36 /**
37 * Public methods and task_t interface.
38 */
39 ike_rekey_t public;
40
41 /**
42 * Assigned IKE_SA.
43 */
44 ike_sa_t *ike_sa;
45
46 /**
47 * New IKE_SA which replaces the current one
48 */
49 ike_sa_t *new_sa;
50
51 /**
52 * Are we the initiator?
53 */
54 bool initiator;
55
56 /**
57 * the TASK_IKE_INIT task which is reused to simplify rekeying
58 */
59 ike_init_t *ike_init;
60
61 /**
62 * IKE_DELETE task to delete the old IKE_SA after rekeying was successful
63 */
64 ike_delete_t *ike_delete;
65
66 /**
67 * colliding task detected by the task manager
68 */
69 task_t *collision;
70
71 /**
72 * TRUE if rekeying can't be handled temporarily
73 */
74 bool failed_temporarily;
75 };
76
77 /**
78 * Schedule a retry if rekeying temporary failed
79 */
80 static void schedule_delayed_rekey(private_ike_rekey_t *this)
81 {
82 uint32_t retry;
83 job_t *job;
84
85 retry = RETRY_INTERVAL - (random() % RETRY_JITTER);
86 job = (job_t*)rekey_ike_sa_job_create(
87 this->ike_sa->get_id(this->ike_sa), FALSE);
88 DBG1(DBG_IKE, "IKE_SA rekeying failed, trying again in %d seconds", retry);
89 this->ike_sa->set_state(this->ike_sa, IKE_ESTABLISHED);
90 lib->scheduler->schedule_job(lib->scheduler, job, retry);
91 }
92
93 /**
94 * Check if an IKE_SA has any queued tasks, return initiation job
95 */
96 static job_t* check_queued_tasks(ike_sa_t *ike_sa)
97 {
98 enumerator_t *enumerator;
99 task_t *task;
100 job_t *job = NULL;
101
102 enumerator = ike_sa->create_task_enumerator(ike_sa, TASK_QUEUE_QUEUED);
103 if (enumerator->enumerate(enumerator, &task))
104 {
105 job = (job_t*)initiate_tasks_job_create(ike_sa->get_id(ike_sa));
106 }
107 enumerator->destroy(enumerator);
108 return job;
109 }
110
111 /**
112 * Establish the new replacement IKE_SA
113 */
114 static void establish_new(private_ike_rekey_t *this)
115 {
116 if (this->new_sa)
117 {
118 job_t *job;
119
120 this->new_sa->set_state(this->new_sa, IKE_ESTABLISHED);
121 DBG0(DBG_IKE, "IKE_SA %s[%d] rekeyed between %H[%Y]...%H[%Y]",
122 this->new_sa->get_name(this->new_sa),
123 this->new_sa->get_unique_id(this->new_sa),
124 this->ike_sa->get_my_host(this->ike_sa),
125 this->ike_sa->get_my_id(this->ike_sa),
126 this->ike_sa->get_other_host(this->ike_sa),
127 this->ike_sa->get_other_id(this->ike_sa));
128
129 this->new_sa->inherit_post(this->new_sa, this->ike_sa);
130 charon->bus->ike_rekey(charon->bus, this->ike_sa, this->new_sa);
131 job = check_queued_tasks(this->new_sa);
132 /* don't queue job before checkin(), as the IKE_SA is not yet
133 * registered at the manager */
134 charon->ike_sa_manager->checkin(charon->ike_sa_manager, this->new_sa);
135 if (job)
136 {
137 lib->processor->queue_job(lib->processor, job);
138 }
139 this->new_sa = NULL;
140 charon->bus->set_sa(charon->bus, this->ike_sa);
141
142 this->ike_sa->set_state(this->ike_sa, IKE_REKEYED);
143 }
144 }
145
146 METHOD(task_t, build_i_delete, status_t,
147 private_ike_rekey_t *this, message_t *message)
148 {
149 /* update exchange type to INFORMATIONAL for the delete */
150 message->set_exchange_type(message, INFORMATIONAL);
151
152 return this->ike_delete->task.build(&this->ike_delete->task, message);
153 }
154
155 METHOD(task_t, process_i_delete, status_t,
156 private_ike_rekey_t *this, message_t *message)
157 {
158 return this->ike_delete->task.process(&this->ike_delete->task, message);
159 }
160
161 METHOD(task_t, build_i, status_t,
162 private_ike_rekey_t *this, message_t *message)
163 {
164 ike_version_t version;
165
166 /* create new SA only on first try */
167 if (this->new_sa == NULL)
168 {
169 version = this->ike_sa->get_version(this->ike_sa);
170 this->new_sa = charon->ike_sa_manager->checkout_new(
171 charon->ike_sa_manager, version, TRUE);
172 if (!this->new_sa)
173 { /* shouldn't happen */
174 return FAILED;
175 }
176 this->new_sa->inherit_pre(this->new_sa, this->ike_sa);
177 this->ike_init = ike_init_create(this->new_sa, TRUE, this->ike_sa);
178 this->ike_sa->set_state(this->ike_sa, IKE_REKEYING);
179 }
180 this->ike_init->task.build(&this->ike_init->task, message);
181
182 return NEED_MORE;
183 }
184
185 /**
186 * Check if there are any half-open children
187 */
188 static bool have_half_open_children(private_ike_rekey_t *this)
189 {
190 enumerator_t *enumerator;
191 child_sa_t *child_sa;
192 task_t *task;
193
194 enumerator = this->ike_sa->create_child_sa_enumerator(this->ike_sa);
195 while (enumerator->enumerate(enumerator, (void**)&child_sa))
196 {
197 switch (child_sa->get_state(child_sa))
198 {
199 case CHILD_REKEYING:
200 case CHILD_RETRYING:
201 case CHILD_DELETING:
202 enumerator->destroy(enumerator);
203 return TRUE;
204 default:
205 break;
206 }
207 }
208 enumerator->destroy(enumerator);
209 enumerator = this->ike_sa->create_task_enumerator(this->ike_sa,
210 TASK_QUEUE_ACTIVE);
211 while (enumerator->enumerate(enumerator, (void**)&task))
212 {
213 if (task->get_type(task) == TASK_CHILD_CREATE)
214 {
215 enumerator->destroy(enumerator);
216 return TRUE;
217 }
218 }
219 enumerator->destroy(enumerator);
220 return FALSE;
221 }
222
223 METHOD(task_t, process_r, status_t,
224 private_ike_rekey_t *this, message_t *message)
225 {
226 if (this->ike_sa->get_state(this->ike_sa) == IKE_DELETING)
227 {
228 DBG1(DBG_IKE, "peer initiated rekeying, but we are deleting");
229 this->failed_temporarily = TRUE;
230 return NEED_MORE;
231 }
232 if (have_half_open_children(this))
233 {
234 DBG1(DBG_IKE, "peer initiated rekeying, but a child is half-open");
235 this->failed_temporarily = TRUE;
236 return NEED_MORE;
237 }
238
239 this->new_sa = charon->ike_sa_manager->checkout_new(charon->ike_sa_manager,
240 this->ike_sa->get_version(this->ike_sa), FALSE);
241 if (!this->new_sa)
242 { /* shouldn't happen */
243 return FAILED;
244 }
245 this->new_sa->inherit_pre(this->new_sa, this->ike_sa);
246 this->ike_init = ike_init_create(this->new_sa, FALSE, this->ike_sa);
247 this->ike_init->task.process(&this->ike_init->task, message);
248
249 return NEED_MORE;
250 }
251
252 METHOD(task_t, build_r, status_t,
253 private_ike_rekey_t *this, message_t *message)
254 {
255 if (this->failed_temporarily)
256 {
257 message->add_notify(message, TRUE, TEMPORARY_FAILURE, chunk_empty);
258 return SUCCESS;
259 }
260 if (this->new_sa == NULL)
261 {
262 /* IKE_SA/a CHILD_SA is in an inacceptable state, deny rekeying */
263 message->add_notify(message, TRUE, NO_PROPOSAL_CHOSEN, chunk_empty);
264 return SUCCESS;
265 }
266 if (this->ike_init->task.build(&this->ike_init->task, message) == FAILED)
267 {
268 this->ike_init->task.destroy(&this->ike_init->task);
269 this->ike_init = NULL;
270 charon->bus->set_sa(charon->bus, this->ike_sa);
271 return SUCCESS;
272 }
273 charon->bus->set_sa(charon->bus, this->ike_sa);
274
275 if (this->ike_sa->get_state(this->ike_sa) != IKE_REKEYING)
276 { /* in case of a collision we let the initiating task handle this */
277 establish_new(this);
278 /* make sure the IKE_SA is gone in case the peer fails to delete it */
279 lib->scheduler->schedule_job(lib->scheduler, (job_t*)
280 delete_ike_sa_job_create(this->ike_sa->get_id(this->ike_sa), TRUE),
281 90);
282 }
283 return SUCCESS;
284 }
285
286 /**
287 * Conclude any undetected rekey collision.
288 *
289 * If the peer does not detect the collision it will delete this IKE_SA.
290 * Depending on when our request reaches the peer and we receive the delete
291 * this may get called at different times.
292 *
293 * Returns TRUE if there was a collision, FALSE otherwise.
294 */
295 static bool conclude_undetected_collision(private_ike_rekey_t *this)
296 {
297 if (this->collision &&
298 this->collision->get_type(this->collision) == TASK_IKE_REKEY)
299 {
300 DBG1(DBG_IKE, "peer did not notice IKE_SA rekey collision, abort "
301 "active rekeying");
302 establish_new((private_ike_rekey_t*)this->collision);
303 return TRUE;
304 }
305 return FALSE;
306 }
307
308 METHOD(task_t, process_i, status_t,
309 private_ike_rekey_t *this, message_t *message)
310 {
311 if (message->get_notify(message, NO_ADDITIONAL_SAS))
312 {
313 DBG1(DBG_IKE, "peer seems to not support IKE rekeying, "
314 "starting reauthentication");
315 this->ike_sa->set_state(this->ike_sa, IKE_ESTABLISHED);
316 lib->processor->queue_job(lib->processor,
317 (job_t*)rekey_ike_sa_job_create(
318 this->ike_sa->get_id(this->ike_sa), TRUE));
319 return SUCCESS;
320 }
321
322 switch (this->ike_init->task.process(&this->ike_init->task, message))
323 {
324 case FAILED:
325 /* rekeying failed, fallback to old SA */
326 if (!conclude_undetected_collision(this))
327 {
328 schedule_delayed_rekey(this);
329 }
330 return SUCCESS;
331 case NEED_MORE:
332 /* bad dh group, try again */
333 this->ike_init->task.migrate(&this->ike_init->task, this->new_sa);
334 return NEED_MORE;
335 default:
336 break;
337 }
338
339 /* check for collisions */
340 if (this->collision &&
341 this->collision->get_type(this->collision) == TASK_IKE_REKEY)
342 {
343 private_ike_rekey_t *other = (private_ike_rekey_t*)this->collision;
344 host_t *host;
345 chunk_t this_nonce, other_nonce;
346
347 this_nonce = this->ike_init->get_lower_nonce(this->ike_init);
348 other_nonce = other->ike_init->get_lower_nonce(other->ike_init);
349
350 /* if we have the lower nonce, delete rekeyed SA. If not, delete
351 * the redundant. */
352 if (memcmp(this_nonce.ptr, other_nonce.ptr,
353 min(this_nonce.len, other_nonce.len)) < 0)
354 {
355 DBG1(DBG_IKE, "IKE_SA rekey collision lost, deleting redundant "
356 "IKE_SA %s[%d]", this->new_sa->get_name(this->new_sa),
357 this->new_sa->get_unique_id(this->new_sa));
358 /* apply host for a proper delete */
359 host = this->ike_sa->get_my_host(this->ike_sa);
360 this->new_sa->set_my_host(this->new_sa, host->clone(host));
361 host = this->ike_sa->get_other_host(this->ike_sa);
362 this->new_sa->set_other_host(this->new_sa, host->clone(host));
363 /* IKE_SAs in state IKE_REKEYED are silently deleted, so we use
364 * IKE_REKEYING */
365 this->new_sa->set_state(this->new_sa, IKE_REKEYING);
366 if (this->new_sa->delete(this->new_sa) == DESTROY_ME)
367 {
368 this->new_sa->destroy(this->new_sa);
369 }
370 else
371 {
372 charon->ike_sa_manager->checkin(charon->ike_sa_manager,
373 this->new_sa);
374 }
375 charon->bus->set_sa(charon->bus, this->ike_sa);
376 this->new_sa = NULL;
377 establish_new(other);
378 return SUCCESS;
379 }
380 /* peer should delete this SA. Add a timeout just in case. */
381 job_t *job = (job_t*)delete_ike_sa_job_create(
382 other->new_sa->get_id(other->new_sa), TRUE);
383 lib->scheduler->schedule_job(lib->scheduler, job,
384 HALF_OPEN_IKE_SA_TIMEOUT);
385 DBG1(DBG_IKE, "IKE_SA rekey collision won, waiting for delete for "
386 "redundant IKE_SA %s[%d]", other->new_sa->get_name(other->new_sa),
387 other->new_sa->get_unique_id(other->new_sa));
388 other->new_sa->set_state(other->new_sa, IKE_REKEYED);
389 charon->ike_sa_manager->checkin(charon->ike_sa_manager, other->new_sa);
390 other->new_sa = NULL;
391 charon->bus->set_sa(charon->bus, this->ike_sa);
392 }
393
394 establish_new(this);
395
396 /* rekeying successful, delete the IKE_SA using a subtask */
397 this->ike_delete = ike_delete_create(this->ike_sa, TRUE);
398 this->public.task.build = _build_i_delete;
399 this->public.task.process = _process_i_delete;
400
401 return NEED_MORE;
402 }
403
404 METHOD(task_t, get_type, task_type_t,
405 private_ike_rekey_t *this)
406 {
407 return TASK_IKE_REKEY;
408 }
409
410 METHOD(ike_rekey_t, did_collide, bool,
411 private_ike_rekey_t *this)
412 {
413 return this->collision &&
414 this->collision->get_type(this->collision) == TASK_IKE_REKEY;
415 }
416
417 METHOD(ike_rekey_t, collide, void,
418 private_ike_rekey_t* this, task_t *other)
419 {
420 DBG1(DBG_IKE, "detected %N collision with %N", task_type_names,
421 TASK_IKE_REKEY, task_type_names, other->get_type(other));
422
423 switch (other->get_type(other))
424 {
425 case TASK_IKE_DELETE:
426 conclude_undetected_collision(this);
427 other->destroy(other);
428 return;
429 case TASK_IKE_REKEY:
430 {
431 private_ike_rekey_t *rekey = (private_ike_rekey_t*)other;
432
433 if (!rekey->ike_init)
434 {
435 DBG1(DBG_IKE, "colliding exchange did not result in an IKE_SA, "
436 "ignore");
437 other->destroy(other);
438 return;
439 }
440 break;
441 }
442 default:
443 break;
444 }
445 DESTROY_IF(this->collision);
446 this->collision = other;
447 }
448
449 /**
450 * Cleanup the task
451 */
452 static void cleanup(private_ike_rekey_t *this)
453 {
454 ike_sa_t *cur_sa;
455
456 if (this->ike_init)
457 {
458 this->ike_init->task.destroy(&this->ike_init->task);
459 }
460 if (this->ike_delete)
461 {
462 this->ike_delete->task.destroy(&this->ike_delete->task);
463 }
464 cur_sa = charon->bus->get_sa(charon->bus);
465 DESTROY_IF(this->new_sa);
466 charon->bus->set_sa(charon->bus, cur_sa);
467 DESTROY_IF(this->collision);
468 }
469
470 METHOD(task_t, migrate, void,
471 private_ike_rekey_t *this, ike_sa_t *ike_sa)
472 {
473 cleanup(this);
474 this->collision = NULL;
475 this->ike_sa = ike_sa;
476 this->new_sa = NULL;
477 this->ike_init = NULL;
478 this->ike_delete = NULL;
479 }
480
481 METHOD(task_t, destroy, void,
482 private_ike_rekey_t *this)
483 {
484 cleanup(this);
485 free(this);
486 }
487
488 /*
489 * Described in header.
490 */
491 ike_rekey_t *ike_rekey_create(ike_sa_t *ike_sa, bool initiator)
492 {
493 private_ike_rekey_t *this;
494
495 INIT(this,
496 .public = {
497 .task = {
498 .get_type = _get_type,
499 .build = _build_r,
500 .process = _process_r,
501 .migrate = _migrate,
502 .destroy = _destroy,
503 },
504 .did_collide = _did_collide,
505 .collide = _collide,
506 },
507 .ike_sa = ike_sa,
508 .initiator = initiator,
509 );
510 if (initiator)
511 {
512 this->public.task.build = _build_i;
513 this->public.task.process = _process_i;
514 }
515
516 return &this->public;
517 }