c7a8a1342c354d1219a888bf2aa619a76838fce3
[strongswan.git] / src / libcharon / sa / ikev2 / tasks / child_rekey.c
1 /*
2 * Copyright (C) 2005-2007 Martin Willi
3 * Copyright (C) 2005 Jan Hutter
4 * Hochschule fuer Technik Rapperswil
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * for more details.
15 */
16
17 #include "child_rekey.h"
18
19 #include <daemon.h>
20 #include <encoding/payloads/notify_payload.h>
21 #include <sa/ikev2/tasks/child_create.h>
22 #include <sa/ikev2/tasks/child_delete.h>
23 #include <processing/jobs/rekey_child_sa_job.h>
24 #include <processing/jobs/rekey_ike_sa_job.h>
25
26
27 typedef struct private_child_rekey_t private_child_rekey_t;
28
29 /**
30 * Private members of a child_rekey_t task.
31 */
32 struct private_child_rekey_t {
33
34 /**
35 * Public methods and task_t interface.
36 */
37 child_rekey_t public;
38
39 /**
40 * Assigned IKE_SA.
41 */
42 ike_sa_t *ike_sa;
43
44 /**
45 * Are we the initiator?
46 */
47 bool initiator;
48
49 /**
50 * Protocol of CHILD_SA to rekey
51 */
52 protocol_id_t protocol;
53
54 /**
55 * Inbound SPI of CHILD_SA to rekey
56 */
57 u_int32_t spi;
58
59 /**
60 * the CHILD_CREATE task which is reused to simplify rekeying
61 */
62 child_create_t *child_create;
63
64 /**
65 * the CHILD_DELETE task to delete rekeyed CHILD_SA
66 */
67 child_delete_t *child_delete;
68
69 /**
70 * CHILD_SA which gets rekeyed
71 */
72 child_sa_t *child_sa;
73
74 /**
75 * colliding task, may be delete or rekey
76 */
77 task_t *collision;
78
79 /**
80 * Indicate that peer destroyed the redundant child from collision.
81 * This happens if a peer's delete notification for the redundant
82 * child gets processed before the rekey job. If so, we must not
83 * touch the child created in the collision since it points to
84 * memory already freed.
85 */
86 bool other_child_destroyed;
87 };
88
89 /**
90 * Schedule a retry if rekeying temporary failed
91 */
92 static void schedule_delayed_rekey(private_child_rekey_t *this)
93 {
94 u_int32_t retry;
95 job_t *job;
96
97 retry = RETRY_INTERVAL - (random() % RETRY_JITTER);
98 job = (job_t*)rekey_child_sa_job_create(
99 this->child_sa->get_protocol(this->child_sa),
100 this->child_sa->get_spi(this->child_sa, TRUE),
101 this->ike_sa->get_my_host(this->ike_sa));
102 DBG1(DBG_IKE, "CHILD_SA rekeying failed, trying again in %d seconds", retry);
103 this->child_sa->set_state(this->child_sa, CHILD_INSTALLED);
104 lib->scheduler->schedule_job(lib->scheduler, job, retry);
105 }
106
107 /**
108 * Implementation of task_t.build for initiator, after rekeying
109 */
110 static status_t build_i_delete(private_child_rekey_t *this, message_t *message)
111 {
112 /* update exchange type to INFORMATIONAL for the delete */
113 message->set_exchange_type(message, INFORMATIONAL);
114
115 return this->child_delete->task.build(&this->child_delete->task, message);
116 }
117
118 /**
119 * Implementation of task_t.process for initiator, after rekeying
120 */
121 static status_t process_i_delete(private_child_rekey_t *this, message_t *message)
122 {
123 return this->child_delete->task.process(&this->child_delete->task, message);
124 }
125
126 /**
127 * find a child using the REKEY_SA notify
128 */
129 static void find_child(private_child_rekey_t *this, message_t *message)
130 {
131 notify_payload_t *notify;
132 protocol_id_t protocol;
133 u_int32_t spi;
134
135 notify = message->get_notify(message, REKEY_SA);
136 if (notify)
137 {
138 protocol = notify->get_protocol_id(notify);
139 spi = notify->get_spi(notify);
140
141 if (protocol == PROTO_ESP || protocol == PROTO_AH)
142 {
143 this->child_sa = this->ike_sa->get_child_sa(this->ike_sa, protocol,
144 spi, FALSE);
145 }
146 }
147 }
148
149 METHOD(task_t, build_i, status_t,
150 private_child_rekey_t *this, message_t *message)
151 {
152 notify_payload_t *notify;
153 u_int32_t reqid;
154 child_cfg_t *config;
155
156 this->child_sa = this->ike_sa->get_child_sa(this->ike_sa, this->protocol,
157 this->spi, TRUE);
158 if (!this->child_sa)
159 { /* check if it is an outbound CHILD_SA */
160 this->child_sa = this->ike_sa->get_child_sa(this->ike_sa, this->protocol,
161 this->spi, FALSE);
162 if (!this->child_sa)
163 { /* CHILD_SA is gone, unable to rekey. As an empty CREATE_CHILD_SA
164 * exchange is invalid, we fall back to an INFORMATIONAL exchange.*/
165 message->set_exchange_type(message, INFORMATIONAL);
166 return SUCCESS;
167 }
168 /* we work only with the inbound SPI */
169 this->spi = this->child_sa->get_spi(this->child_sa, TRUE);
170 }
171 config = this->child_sa->get_config(this->child_sa);
172
173
174 /* our CHILD_CREATE task does the hard work for us */
175 if (!this->child_create)
176 {
177 this->child_create = child_create_create(this->ike_sa,
178 config->get_ref(config), TRUE, NULL, NULL);
179 }
180 reqid = this->child_sa->get_reqid(this->child_sa);
181 this->child_create->use_reqid(this->child_create, reqid);
182 this->child_create->use_marks(this->child_create,
183 this->child_sa->get_mark(this->child_sa, TRUE).value,
184 this->child_sa->get_mark(this->child_sa, FALSE).value);
185
186 if (this->child_create->task.build(&this->child_create->task,
187 message) != NEED_MORE)
188 {
189 schedule_delayed_rekey(this);
190 return FAILED;
191 }
192 if (message->get_exchange_type(message) == CREATE_CHILD_SA)
193 {
194 /* don't add the notify if the CHILD_CREATE task changed the exchange */
195 notify = notify_payload_create_from_protocol_and_type(PLV2_NOTIFY,
196 this->protocol, REKEY_SA);
197 notify->set_spi(notify, this->spi);
198 message->add_payload(message, (payload_t*)notify);
199 }
200 this->child_sa->set_state(this->child_sa, CHILD_REKEYING);
201
202 return NEED_MORE;
203 }
204
205 METHOD(task_t, process_r, status_t,
206 private_child_rekey_t *this, message_t *message)
207 {
208 /* let the CHILD_CREATE task process the message */
209 this->child_create->task.process(&this->child_create->task, message);
210
211 find_child(this, message);
212
213 return NEED_MORE;
214 }
215
216 METHOD(task_t, build_r, status_t,
217 private_child_rekey_t *this, message_t *message)
218 {
219 child_cfg_t *config;
220 u_int32_t reqid;
221
222 if (this->child_sa == NULL ||
223 this->child_sa->get_state(this->child_sa) == CHILD_DELETING)
224 {
225 DBG1(DBG_IKE, "unable to rekey, CHILD_SA not found");
226 message->add_notify(message, TRUE, NO_PROPOSAL_CHOSEN, chunk_empty);
227 return SUCCESS;
228 }
229
230 /* let the CHILD_CREATE task build the response */
231 reqid = this->child_sa->get_reqid(this->child_sa);
232 this->child_create->use_reqid(this->child_create, reqid);
233 this->child_create->use_marks(this->child_create,
234 this->child_sa->get_mark(this->child_sa, TRUE).value,
235 this->child_sa->get_mark(this->child_sa, FALSE).value);
236 config = this->child_sa->get_config(this->child_sa);
237 this->child_create->set_config(this->child_create, config->get_ref(config));
238 this->child_create->task.build(&this->child_create->task, message);
239
240 if (message->get_payload(message, PLV2_SECURITY_ASSOCIATION) == NULL)
241 {
242 /* rekeying failed, reuse old child */
243 this->child_sa->set_state(this->child_sa, CHILD_INSTALLED);
244 return SUCCESS;
245 }
246
247 this->child_sa->set_state(this->child_sa, CHILD_REKEYING);
248
249 /* invoke rekey hook */
250 charon->bus->child_rekey(charon->bus, this->child_sa,
251 this->child_create->get_child(this->child_create));
252 return SUCCESS;
253 }
254
255 /**
256 * Handle a rekey collision
257 */
258 static child_sa_t *handle_collision(private_child_rekey_t *this)
259 {
260 child_sa_t *to_delete;
261
262 if (this->collision->get_type(this->collision) == TASK_CHILD_REKEY)
263 {
264 chunk_t this_nonce, other_nonce;
265 private_child_rekey_t *other = (private_child_rekey_t*)this->collision;
266
267 this_nonce = this->child_create->get_lower_nonce(this->child_create);
268 other_nonce = other->child_create->get_lower_nonce(other->child_create);
269
270 /* if we have the lower nonce, delete rekeyed SA. If not, delete
271 * the redundant. */
272 if (memcmp(this_nonce.ptr, other_nonce.ptr,
273 min(this_nonce.len, other_nonce.len)) > 0)
274 {
275 child_sa_t *child_sa;
276
277 DBG1(DBG_IKE, "CHILD_SA rekey collision won, deleting old child");
278 to_delete = this->child_sa;
279 /* don't touch child other created, it has already been deleted */
280 if (!this->other_child_destroyed)
281 {
282 /* disable close action for the redundand child */
283 child_sa = other->child_create->get_child(other->child_create);
284 if (child_sa)
285 {
286 child_sa->set_close_action(child_sa, ACTION_NONE);
287 }
288 }
289 }
290 else
291 {
292 DBG1(DBG_IKE, "CHILD_SA rekey collision lost, "
293 "deleting rekeyed child");
294 to_delete = this->child_create->get_child(this->child_create);
295 }
296 }
297 else
298 { /* CHILD_DELETE */
299 child_delete_t *del = (child_delete_t*)this->collision;
300
301 /* we didn't had a chance to compare the nonces, so we delete
302 * the CHILD_SA the other is not deleting. */
303 if (del->get_child(del) != this->child_sa)
304 {
305 DBG1(DBG_IKE, "CHILD_SA rekey/delete collision, "
306 "deleting rekeyed child");
307 to_delete = this->child_sa;
308 }
309 else
310 {
311 DBG1(DBG_IKE, "CHILD_SA rekey/delete collision, "
312 "deleting redundant child");
313 to_delete = this->child_create->get_child(this->child_create);
314 }
315 }
316 return to_delete;
317 }
318
319 METHOD(task_t, process_i, status_t,
320 private_child_rekey_t *this, message_t *message)
321 {
322 protocol_id_t protocol;
323 u_int32_t spi;
324 child_sa_t *to_delete;
325
326 if (message->get_notify(message, NO_ADDITIONAL_SAS))
327 {
328 DBG1(DBG_IKE, "peer seems to not support CHILD_SA rekeying, "
329 "starting reauthentication");
330 this->child_sa->set_state(this->child_sa, CHILD_INSTALLED);
331 lib->processor->queue_job(lib->processor,
332 (job_t*)rekey_ike_sa_job_create(
333 this->ike_sa->get_id(this->ike_sa), TRUE));
334 return SUCCESS;
335 }
336
337 if (this->child_create->task.process(&this->child_create->task,
338 message) == NEED_MORE)
339 {
340 /* bad DH group while rekeying, retry, or failure requiring deletion */
341 return NEED_MORE;
342 }
343 if (message->get_payload(message, PLV2_SECURITY_ASSOCIATION) == NULL)
344 {
345 /* establishing new child failed, reuse old. but not when we
346 * received a delete in the meantime */
347 if (!(this->collision &&
348 this->collision->get_type(this->collision) == TASK_CHILD_DELETE))
349 {
350 schedule_delayed_rekey(this);
351 }
352 return SUCCESS;
353 }
354
355 /* check for rekey collisions */
356 if (this->collision)
357 {
358 to_delete = handle_collision(this);
359 }
360 else
361 {
362 to_delete = this->child_sa;
363 }
364
365 if (to_delete != this->child_create->get_child(this->child_create))
366 { /* invoke rekey hook if rekeying successful */
367 charon->bus->child_rekey(charon->bus, this->child_sa,
368 this->child_create->get_child(this->child_create));
369 }
370
371 if (to_delete == NULL)
372 {
373 return SUCCESS;
374 }
375 spi = to_delete->get_spi(to_delete, TRUE);
376 protocol = to_delete->get_protocol(to_delete);
377
378 /* rekeying done, delete the obsolete CHILD_SA using a subtask */
379 this->child_delete = child_delete_create(this->ike_sa, protocol, spi, FALSE);
380 this->public.task.build = (status_t(*)(task_t*,message_t*))build_i_delete;
381 this->public.task.process = (status_t(*)(task_t*,message_t*))process_i_delete;
382
383 return NEED_MORE;
384 }
385
386 METHOD(task_t, get_type, task_type_t,
387 private_child_rekey_t *this)
388 {
389 return TASK_CHILD_REKEY;
390 }
391
392 METHOD(child_rekey_t, collide, void,
393 private_child_rekey_t *this, task_t *other)
394 {
395 /* the task manager only detects exchange collision, but not if
396 * the collision is for the same child. we check it here. */
397 if (other->get_type(other) == TASK_CHILD_REKEY)
398 {
399 private_child_rekey_t *rekey = (private_child_rekey_t*)other;
400 if (rekey->child_sa != this->child_sa)
401 {
402 /* not the same child => no collision */
403 other->destroy(other);
404 return;
405 }
406 }
407 else if (other->get_type(other) == TASK_CHILD_DELETE)
408 {
409 child_delete_t *del = (child_delete_t*)other;
410 if (this->collision &&
411 this->collision->get_type(this->collision) == TASK_CHILD_REKEY)
412 {
413 private_child_rekey_t *rekey;
414
415 rekey = (private_child_rekey_t*)this->collision;
416 if (del->get_child(del) == rekey->child_create->get_child(rekey->child_create))
417 {
418 /* peer deletes redundant child created in collision */
419 this->other_child_destroyed = TRUE;
420 other->destroy(other);
421 return;
422 }
423 }
424 if (del->get_child(del) != this->child_sa)
425 {
426 /* not the same child => no collision */
427 other->destroy(other);
428 return;
429 }
430 }
431 else
432 {
433 /* any other task is not critical for collisisions, ignore */
434 other->destroy(other);
435 return;
436 }
437 DBG1(DBG_IKE, "detected %N collision with %N", task_type_names,
438 TASK_CHILD_REKEY, task_type_names, other->get_type(other));
439 DESTROY_IF(this->collision);
440 this->collision = other;
441 }
442
443 METHOD(task_t, migrate, void,
444 private_child_rekey_t *this, ike_sa_t *ike_sa)
445 {
446 if (this->child_create)
447 {
448 this->child_create->task.migrate(&this->child_create->task, ike_sa);
449 }
450 if (this->child_delete)
451 {
452 this->child_delete->task.migrate(&this->child_delete->task, ike_sa);
453 }
454 DESTROY_IF(this->collision);
455
456 this->ike_sa = ike_sa;
457 this->collision = NULL;
458 }
459
460 METHOD(task_t, destroy, void,
461 private_child_rekey_t *this)
462 {
463 if (this->child_create)
464 {
465 this->child_create->task.destroy(&this->child_create->task);
466 }
467 if (this->child_delete)
468 {
469 this->child_delete->task.destroy(&this->child_delete->task);
470 }
471 DESTROY_IF(this->collision);
472 free(this);
473 }
474
475 /*
476 * Described in header.
477 */
478 child_rekey_t *child_rekey_create(ike_sa_t *ike_sa, protocol_id_t protocol,
479 u_int32_t spi)
480 {
481 private_child_rekey_t *this;
482
483 INIT(this,
484 .public = {
485 .task = {
486 .get_type = _get_type,
487 .migrate = _migrate,
488 .destroy = _destroy,
489 },
490 .collide = _collide,
491 },
492 .ike_sa = ike_sa,
493 .protocol = protocol,
494 .spi = spi,
495 );
496
497 if (protocol != PROTO_NONE)
498 {
499 this->public.task.build = _build_i;
500 this->public.task.process = _process_i;
501 this->initiator = TRUE;
502 this->child_create = NULL;
503 }
504 else
505 {
506 this->public.task.build = _build_r;
507 this->public.task.process = _process_r;
508 this->initiator = FALSE;
509 this->child_create = child_create_create(ike_sa, NULL, TRUE, NULL, NULL);
510 }
511
512 return &this->public;
513 }