Use get_notify() to look up single notifies
[strongswan.git] / src / charon / sa / 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/tasks/child_create.h>
22 #include <sa/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 /**
81 * Implementation of task_t.build for initiator, after rekeying
82 */
83 static status_t build_i_delete(private_child_rekey_t *this, message_t *message)
84 {
85 /* update exchange type to INFORMATIONAL for the delete */
86 message->set_exchange_type(message, INFORMATIONAL);
87
88 return this->child_delete->task.build(&this->child_delete->task, message);
89 }
90
91 /**
92 * Implementation of task_t.process for initiator, after rekeying
93 */
94 static status_t process_i_delete(private_child_rekey_t *this, message_t *message)
95 {
96 return this->child_delete->task.process(&this->child_delete->task, message);
97 }
98
99 /**
100 * find a child using the REKEY_SA notify
101 */
102 static void find_child(private_child_rekey_t *this, message_t *message)
103 {
104 notify_payload_t *notify;
105 protocol_id_t protocol;
106 u_int32_t spi;
107
108 notify = message->get_notify(message, REKEY_SA);
109 if (notify)
110 {
111 protocol = notify->get_protocol_id(notify);
112 spi = notify->get_spi(notify);
113
114 if (protocol == PROTO_ESP || protocol == PROTO_AH)
115 {
116 this->child_sa = this->ike_sa->get_child_sa(this->ike_sa, protocol,
117 spi, FALSE);
118 }
119 }
120 }
121
122 /**
123 * Implementation of task_t.build for initiator
124 */
125 static status_t build_i(private_child_rekey_t *this, message_t *message)
126 {
127 notify_payload_t *notify;
128 u_int32_t reqid;
129 child_cfg_t *config;
130
131 this->child_sa = this->ike_sa->get_child_sa(this->ike_sa, this->protocol,
132 this->spi, TRUE);
133 if (!this->child_sa)
134 { /* check if it is an outbound CHILD_SA */
135 this->child_sa = this->ike_sa->get_child_sa(this->ike_sa, this->protocol,
136 this->spi, FALSE);
137 if (!this->child_sa)
138 { /* CHILD_SA is gone, unable to rekey */
139 return SUCCESS;
140 }
141 /* we work only with the inbound SPI */
142 this->spi = this->child_sa->get_spi(this->child_sa, TRUE);
143 }
144 config = this->child_sa->get_config(this->child_sa);
145
146 /* we just need the rekey notify ... */
147 notify = notify_payload_create_from_protocol_and_type(this->protocol,
148 REKEY_SA);
149 notify->set_spi(notify, this->spi);
150 message->add_payload(message, (payload_t*)notify);
151
152 /* ... our CHILD_CREATE task does the hard work for us. */
153 reqid = this->child_sa->get_reqid(this->child_sa);
154 this->child_create = child_create_create(this->ike_sa, config, TRUE,
155 NULL, NULL);
156 this->child_create->use_reqid(this->child_create, reqid);
157 this->child_create->task.build(&this->child_create->task, message);
158
159 this->child_sa->set_state(this->child_sa, CHILD_REKEYING);
160
161 return NEED_MORE;
162 }
163
164 /**
165 * Implementation of task_t.process for initiator
166 */
167 static status_t process_r(private_child_rekey_t *this, message_t *message)
168 {
169 /* let the CHILD_CREATE task process the message */
170 this->child_create->task.process(&this->child_create->task, message);
171
172 find_child(this, message);
173
174 return NEED_MORE;
175 }
176
177 /**
178 * Implementation of task_t.build for responder
179 */
180 static status_t build_r(private_child_rekey_t *this, message_t *message)
181 {
182 u_int32_t reqid;
183
184 if (this->child_sa == NULL ||
185 this->child_sa->get_state(this->child_sa) == CHILD_DELETING)
186 {
187 DBG1(DBG_IKE, "unable to rekey, CHILD_SA not found");
188 message->add_notify(message, TRUE, NO_PROPOSAL_CHOSEN, chunk_empty);
189 return SUCCESS;
190 }
191
192 /* let the CHILD_CREATE task build the response */
193 reqid = this->child_sa->get_reqid(this->child_sa);
194 this->child_create->use_reqid(this->child_create, reqid);
195 this->child_create->task.build(&this->child_create->task, message);
196
197 if (message->get_payload(message, SECURITY_ASSOCIATION) == NULL)
198 {
199 /* rekeying failed, reuse old child */
200 this->child_sa->set_state(this->child_sa, CHILD_INSTALLED);
201 return SUCCESS;
202 }
203
204 this->child_sa->set_state(this->child_sa, CHILD_REKEYING);
205
206 /* invoke rekey hook */
207 charon->bus->child_rekey(charon->bus, this->child_sa,
208 this->child_create->get_child(this->child_create));
209 return SUCCESS;
210 }
211
212 /**
213 * Implementation of task_t.process for initiator
214 */
215 static status_t process_i(private_child_rekey_t *this, message_t *message)
216 {
217 protocol_id_t protocol;
218 u_int32_t spi;
219 child_sa_t *to_delete;
220
221 if (message->get_notify(message, NO_ADDITIONAL_SAS))
222 {
223 DBG1(DBG_IKE, "peer seems to not support CHILD_SA rekeying, "
224 "starting reauthentication");
225 this->child_sa->set_state(this->child_sa, CHILD_INSTALLED);
226 charon->processor->queue_job(charon->processor,
227 (job_t*)rekey_ike_sa_job_create(
228 this->ike_sa->get_id(this->ike_sa), TRUE));
229 return SUCCESS;
230 }
231
232 if (this->child_create->task.process(&this->child_create->task,
233 message) == NEED_MORE)
234 {
235 /* bad DH group while rekeying, try again */
236 this->child_create->task.migrate(&this->child_create->task, this->ike_sa);
237 return NEED_MORE;
238 }
239 if (message->get_payload(message, SECURITY_ASSOCIATION) == NULL)
240 {
241 /* establishing new child failed, reuse old. but not when we
242 * recieved a delete in the meantime */
243 if (!(this->collision &&
244 this->collision->get_type(this->collision) == CHILD_DELETE))
245 {
246 job_t *job;
247 u_int32_t retry = RETRY_INTERVAL - (random() % RETRY_JITTER);
248
249 job = (job_t*)rekey_child_sa_job_create(
250 this->child_sa->get_reqid(this->child_sa),
251 this->child_sa->get_protocol(this->child_sa),
252 this->child_sa->get_spi(this->child_sa, TRUE));
253 DBG1(DBG_IKE, "CHILD_SA rekeying failed, "
254 "trying again in %d seconds", retry);
255 this->child_sa->set_state(this->child_sa, CHILD_INSTALLED);
256 charon->scheduler->schedule_job(charon->scheduler, job, retry);
257 }
258 return SUCCESS;
259 }
260
261 to_delete = this->child_sa;
262
263 /* check for rekey collisions */
264 if (this->collision &&
265 this->collision->get_type(this->collision) == CHILD_REKEY)
266 {
267 chunk_t this_nonce, other_nonce;
268 private_child_rekey_t *other = (private_child_rekey_t*)this->collision;
269
270 this_nonce = this->child_create->get_lower_nonce(this->child_create);
271 other_nonce = other->child_create->get_lower_nonce(other->child_create);
272
273 /* if we have the lower nonce, delete rekeyed SA. If not, delete
274 * the redundant. */
275 if (memcmp(this_nonce.ptr, other_nonce.ptr,
276 min(this_nonce.len, other_nonce.len)) < 0)
277 {
278 DBG1(DBG_IKE, "CHILD_SA rekey collision won, deleting rekeyed child");
279 }
280 else
281 {
282 DBG1(DBG_IKE, "CHILD_SA rekey collision lost, deleting redundant child");
283 to_delete = this->child_create->get_child(this->child_create);
284 if (to_delete == NULL)
285 {
286 /* ooops, should not happen, fallback */
287 to_delete = this->child_sa;
288 }
289 }
290 }
291
292 if (to_delete != this->child_create->get_child(this->child_create))
293 { /* invoke rekey hook if rekeying successful */
294 charon->bus->child_rekey(charon->bus, this->child_sa,
295 this->child_create->get_child(this->child_create));
296 }
297
298 spi = to_delete->get_spi(to_delete, TRUE);
299 protocol = to_delete->get_protocol(to_delete);
300
301 /* rekeying done, delete the obsolete CHILD_SA using a subtask */
302 this->child_delete = child_delete_create(this->ike_sa, protocol, spi);
303 this->public.task.build = (status_t(*)(task_t*,message_t*))build_i_delete;
304 this->public.task.process = (status_t(*)(task_t*,message_t*))process_i_delete;
305
306 return NEED_MORE;
307 }
308
309 /**
310 * Implementation of task_t.get_type
311 */
312 static task_type_t get_type(private_child_rekey_t *this)
313 {
314 return CHILD_REKEY;
315 }
316
317 /**
318 * Implementation of child_rekey_t.collide
319 */
320 static void collide(private_child_rekey_t *this, task_t *other)
321 {
322 /* the task manager only detects exchange collision, but not if
323 * the collision is for the same child. we check it here. */
324 if (other->get_type(other) == CHILD_REKEY)
325 {
326 private_child_rekey_t *rekey = (private_child_rekey_t*)other;
327 if (rekey == NULL || rekey->child_sa != this->child_sa)
328 {
329 /* not the same child => no collision */
330 return;
331 }
332 }
333 else if (other->get_type(other) == CHILD_DELETE)
334 {
335 child_delete_t *del = (child_delete_t*)other;
336 if (del == NULL || del->get_child(del) != this->child_sa)
337 {
338 /* not the same child => no collision */
339 return;
340 }
341 }
342 else
343 {
344 /* any other task is not critical for collisisions, ignore */
345 return;
346 }
347 DESTROY_IF(this->collision);
348 this->collision = other;
349 }
350
351 /**
352 * Implementation of task_t.migrate
353 */
354 static void migrate(private_child_rekey_t *this, ike_sa_t *ike_sa)
355 {
356 if (this->child_create)
357 {
358 this->child_create->task.migrate(&this->child_create->task, ike_sa);
359 }
360 if (this->child_delete)
361 {
362 this->child_delete->task.migrate(&this->child_delete->task, ike_sa);
363 }
364 DESTROY_IF(this->collision);
365
366 this->ike_sa = ike_sa;
367 this->collision = NULL;
368 }
369
370 /**
371 * Implementation of task_t.destroy
372 */
373 static void destroy(private_child_rekey_t *this)
374 {
375 if (this->child_create)
376 {
377 this->child_create->task.destroy(&this->child_create->task);
378 }
379 if (this->child_delete)
380 {
381 this->child_delete->task.destroy(&this->child_delete->task);
382 }
383 DESTROY_IF(this->collision);
384 free(this);
385 }
386
387 /*
388 * Described in header.
389 */
390 child_rekey_t *child_rekey_create(ike_sa_t *ike_sa, protocol_id_t protocol,
391 u_int32_t spi)
392 {
393 private_child_rekey_t *this = malloc_thing(private_child_rekey_t);
394
395 this->public.collide = (void (*)(child_rekey_t*,task_t*))collide;
396 this->public.task.get_type = (task_type_t(*)(task_t*))get_type;
397 this->public.task.migrate = (void(*)(task_t*,ike_sa_t*))migrate;
398 this->public.task.destroy = (void(*)(task_t*))destroy;
399 if (protocol != PROTO_NONE)
400 {
401 this->public.task.build = (status_t(*)(task_t*,message_t*))build_i;
402 this->public.task.process = (status_t(*)(task_t*,message_t*))process_i;
403 this->initiator = TRUE;
404 this->child_create = NULL;
405 }
406 else
407 {
408 this->public.task.build = (status_t(*)(task_t*,message_t*))build_r;
409 this->public.task.process = (status_t(*)(task_t*,message_t*))process_r;
410 this->initiator = FALSE;
411 this->child_create = child_create_create(ike_sa, NULL, TRUE, NULL, NULL);
412 }
413
414 this->ike_sa = ike_sa;
415 this->child_sa = NULL;
416 this->protocol = protocol;
417 this->spi = spi;
418 this->collision = NULL;
419 this->child_delete = NULL;
420
421 return &this->public;
422 }