child-sa: Replace reqid based marks by "unique" marks
[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_reqid(this->child_sa),
100 this->child_sa->get_protocol(this->child_sa),
101 this->child_sa->get_spi(this->child_sa, TRUE));
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 /* we just need the rekey notify ... */
174 notify = notify_payload_create_from_protocol_and_type(PLV2_NOTIFY,
175 this->protocol, REKEY_SA);
176 notify->set_spi(notify, this->spi);
177 message->add_payload(message, (payload_t*)notify);
178
179 /* ... our CHILD_CREATE task does the hard work for us. */
180 if (!this->child_create)
181 {
182 this->child_create = child_create_create(this->ike_sa,
183 config->get_ref(config), TRUE, NULL, NULL);
184 }
185 reqid = this->child_sa->get_reqid(this->child_sa);
186 this->child_create->use_reqid(this->child_create, reqid);
187 this->child_create->use_marks(this->child_create,
188 this->child_sa->get_mark(this->child_sa, TRUE).value,
189 this->child_sa->get_mark(this->child_sa, FALSE).value);
190
191 if (this->child_create->task.build(&this->child_create->task,
192 message) != NEED_MORE)
193 {
194 schedule_delayed_rekey(this);
195 return FAILED;
196 }
197 this->child_sa->set_state(this->child_sa, CHILD_REKEYING);
198
199 return NEED_MORE;
200 }
201
202 METHOD(task_t, process_r, status_t,
203 private_child_rekey_t *this, message_t *message)
204 {
205 /* let the CHILD_CREATE task process the message */
206 this->child_create->task.process(&this->child_create->task, message);
207
208 find_child(this, message);
209
210 return NEED_MORE;
211 }
212
213 METHOD(task_t, build_r, status_t,
214 private_child_rekey_t *this, message_t *message)
215 {
216 child_cfg_t *config;
217 u_int32_t reqid;
218
219 if (this->child_sa == NULL ||
220 this->child_sa->get_state(this->child_sa) == CHILD_DELETING)
221 {
222 DBG1(DBG_IKE, "unable to rekey, CHILD_SA not found");
223 message->add_notify(message, TRUE, NO_PROPOSAL_CHOSEN, chunk_empty);
224 return SUCCESS;
225 }
226
227 /* let the CHILD_CREATE task build the response */
228 reqid = this->child_sa->get_reqid(this->child_sa);
229 this->child_create->use_reqid(this->child_create, reqid);
230 this->child_create->use_marks(this->child_create,
231 this->child_sa->get_mark(this->child_sa, TRUE).value,
232 this->child_sa->get_mark(this->child_sa, FALSE).value);
233 config = this->child_sa->get_config(this->child_sa);
234 this->child_create->set_config(this->child_create, config->get_ref(config));
235 this->child_create->task.build(&this->child_create->task, message);
236
237 if (message->get_payload(message, PLV2_SECURITY_ASSOCIATION) == NULL)
238 {
239 /* rekeying failed, reuse old child */
240 this->child_sa->set_state(this->child_sa, CHILD_INSTALLED);
241 return SUCCESS;
242 }
243
244 this->child_sa->set_state(this->child_sa, CHILD_REKEYING);
245
246 /* invoke rekey hook */
247 charon->bus->child_rekey(charon->bus, this->child_sa,
248 this->child_create->get_child(this->child_create));
249 return SUCCESS;
250 }
251
252 /**
253 * Handle a rekey collision
254 */
255 static child_sa_t *handle_collision(private_child_rekey_t *this)
256 {
257 child_sa_t *to_delete;
258
259 if (this->collision->get_type(this->collision) == TASK_CHILD_REKEY)
260 {
261 chunk_t this_nonce, other_nonce;
262 private_child_rekey_t *other = (private_child_rekey_t*)this->collision;
263
264 this_nonce = this->child_create->get_lower_nonce(this->child_create);
265 other_nonce = other->child_create->get_lower_nonce(other->child_create);
266
267 /* if we have the lower nonce, delete rekeyed SA. If not, delete
268 * the redundant. */
269 if (memcmp(this_nonce.ptr, other_nonce.ptr,
270 min(this_nonce.len, other_nonce.len)) > 0)
271 {
272 child_sa_t *child_sa;
273
274 DBG1(DBG_IKE, "CHILD_SA rekey collision won, deleting old child");
275 to_delete = this->child_sa;
276 /* don't touch child other created, it has already been deleted */
277 if (!this->other_child_destroyed)
278 {
279 /* disable close action for the redundand child */
280 child_sa = other->child_create->get_child(other->child_create);
281 if (child_sa)
282 {
283 child_sa->set_close_action(child_sa, ACTION_NONE);
284 }
285 }
286 }
287 else
288 {
289 DBG1(DBG_IKE, "CHILD_SA rekey collision lost, "
290 "deleting rekeyed child");
291 to_delete = this->child_create->get_child(this->child_create);
292 }
293 }
294 else
295 { /* CHILD_DELETE */
296 child_delete_t *del = (child_delete_t*)this->collision;
297
298 /* we didn't had a chance to compare the nonces, so we delete
299 * the CHILD_SA the other is not deleting. */
300 if (del->get_child(del) != this->child_sa)
301 {
302 DBG1(DBG_IKE, "CHILD_SA rekey/delete collision, "
303 "deleting rekeyed child");
304 to_delete = this->child_sa;
305 }
306 else
307 {
308 DBG1(DBG_IKE, "CHILD_SA rekey/delete collision, "
309 "deleting redundant child");
310 to_delete = this->child_create->get_child(this->child_create);
311 }
312 }
313 return to_delete;
314 }
315
316 METHOD(task_t, process_i, status_t,
317 private_child_rekey_t *this, message_t *message)
318 {
319 protocol_id_t protocol;
320 u_int32_t spi;
321 child_sa_t *to_delete;
322
323 if (message->get_notify(message, NO_ADDITIONAL_SAS))
324 {
325 DBG1(DBG_IKE, "peer seems to not support CHILD_SA rekeying, "
326 "starting reauthentication");
327 this->child_sa->set_state(this->child_sa, CHILD_INSTALLED);
328 lib->processor->queue_job(lib->processor,
329 (job_t*)rekey_ike_sa_job_create(
330 this->ike_sa->get_id(this->ike_sa), TRUE));
331 return SUCCESS;
332 }
333
334 if (this->child_create->task.process(&this->child_create->task,
335 message) == NEED_MORE)
336 {
337 /* bad DH group while rekeying, try again */
338 this->child_create->task.migrate(&this->child_create->task, this->ike_sa);
339 return NEED_MORE;
340 }
341 if (message->get_payload(message, PLV2_SECURITY_ASSOCIATION) == NULL)
342 {
343 /* establishing new child failed, reuse old. but not when we
344 * received a delete in the meantime */
345 if (!(this->collision &&
346 this->collision->get_type(this->collision) == TASK_CHILD_DELETE))
347 {
348 schedule_delayed_rekey(this);
349 }
350 return SUCCESS;
351 }
352
353 /* check for rekey collisions */
354 if (this->collision)
355 {
356 to_delete = handle_collision(this);
357 }
358 else
359 {
360 to_delete = this->child_sa;
361 }
362
363 if (to_delete != this->child_create->get_child(this->child_create))
364 { /* invoke rekey hook if rekeying successful */
365 charon->bus->child_rekey(charon->bus, this->child_sa,
366 this->child_create->get_child(this->child_create));
367 }
368
369 if (to_delete == NULL)
370 {
371 return SUCCESS;
372 }
373 spi = to_delete->get_spi(to_delete, TRUE);
374 protocol = to_delete->get_protocol(to_delete);
375
376 /* rekeying done, delete the obsolete CHILD_SA using a subtask */
377 this->child_delete = child_delete_create(this->ike_sa, protocol, spi, FALSE);
378 this->public.task.build = (status_t(*)(task_t*,message_t*))build_i_delete;
379 this->public.task.process = (status_t(*)(task_t*,message_t*))process_i_delete;
380
381 return NEED_MORE;
382 }
383
384 METHOD(task_t, get_type, task_type_t,
385 private_child_rekey_t *this)
386 {
387 return TASK_CHILD_REKEY;
388 }
389
390 METHOD(child_rekey_t, collide, void,
391 private_child_rekey_t *this, task_t *other)
392 {
393 /* the task manager only detects exchange collision, but not if
394 * the collision is for the same child. we check it here. */
395 if (other->get_type(other) == TASK_CHILD_REKEY)
396 {
397 private_child_rekey_t *rekey = (private_child_rekey_t*)other;
398 if (rekey->child_sa != this->child_sa)
399 {
400 /* not the same child => no collision */
401 other->destroy(other);
402 return;
403 }
404 }
405 else if (other->get_type(other) == TASK_CHILD_DELETE)
406 {
407 child_delete_t *del = (child_delete_t*)other;
408 if (this->collision &&
409 this->collision->get_type(this->collision) == TASK_CHILD_REKEY)
410 {
411 private_child_rekey_t *rekey;
412
413 rekey = (private_child_rekey_t*)this->collision;
414 if (del->get_child(del) == rekey->child_create->get_child(rekey->child_create))
415 {
416 /* peer deletes redundant child created in collision */
417 this->other_child_destroyed = TRUE;
418 other->destroy(other);
419 return;
420 }
421 }
422 if (del->get_child(del) != this->child_sa)
423 {
424 /* not the same child => no collision */
425 other->destroy(other);
426 return;
427 }
428 }
429 else
430 {
431 /* any other task is not critical for collisisions, ignore */
432 other->destroy(other);
433 return;
434 }
435 DBG1(DBG_IKE, "detected %N collision with %N", task_type_names,
436 TASK_CHILD_REKEY, task_type_names, other->get_type(other));
437 DESTROY_IF(this->collision);
438 this->collision = other;
439 }
440
441 METHOD(task_t, migrate, void,
442 private_child_rekey_t *this, ike_sa_t *ike_sa)
443 {
444 if (this->child_create)
445 {
446 this->child_create->task.migrate(&this->child_create->task, ike_sa);
447 }
448 if (this->child_delete)
449 {
450 this->child_delete->task.migrate(&this->child_delete->task, ike_sa);
451 }
452 DESTROY_IF(this->collision);
453
454 this->ike_sa = ike_sa;
455 this->collision = NULL;
456 }
457
458 METHOD(task_t, destroy, void,
459 private_child_rekey_t *this)
460 {
461 if (this->child_create)
462 {
463 this->child_create->task.destroy(&this->child_create->task);
464 }
465 if (this->child_delete)
466 {
467 this->child_delete->task.destroy(&this->child_delete->task);
468 }
469 DESTROY_IF(this->collision);
470 free(this);
471 }
472
473 /*
474 * Described in header.
475 */
476 child_rekey_t *child_rekey_create(ike_sa_t *ike_sa, protocol_id_t protocol,
477 u_int32_t spi)
478 {
479 private_child_rekey_t *this;
480
481 INIT(this,
482 .public = {
483 .task = {
484 .get_type = _get_type,
485 .migrate = _migrate,
486 .destroy = _destroy,
487 },
488 .collide = _collide,
489 },
490 .ike_sa = ike_sa,
491 .protocol = protocol,
492 .spi = spi,
493 );
494
495 if (protocol != PROTO_NONE)
496 {
497 this->public.task.build = _build_i;
498 this->public.task.process = _process_i;
499 this->initiator = TRUE;
500 this->child_create = NULL;
501 }
502 else
503 {
504 this->public.task.build = _build_r;
505 this->public.task.process = _process_r;
506 this->initiator = FALSE;
507 this->child_create = child_create_create(ike_sa, NULL, TRUE, NULL, NULL);
508 }
509
510 return &this->public;
511 }