Annotation of embedaddon/strongswan/src/libcharon/sa/task_manager.h, revision 1.1.1.1
1.1 misho 1: /*
2: * Copyright (C) 2013-2018 Tobias Brunner
3: * Copyright (C) 2006 Martin Willi
4: * HSR 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: /**
18: * @defgroup task_manager task_manager
19: * @{ @ingroup sa
20: */
21:
22: #ifndef TASK_MANAGER_H_
23: #define TASK_MANAGER_H_
24:
25: typedef struct task_manager_t task_manager_t;
26: typedef enum task_queue_t task_queue_t;
27:
28: #include <limits.h>
29:
30: #include <library.h>
31: #include <encoding/message.h>
32: #include <sa/ike_sa.h>
33: #include <sa/task.h>
34:
35: /**
36: * First retransmit timeout in seconds.
37: */
38: #define RETRANSMIT_TIMEOUT 4.0
39:
40: /**
41: * Base which is raised to the power of the retransmission try.
42: */
43: #define RETRANSMIT_BASE 1.8
44:
45: /**
46: * Number of retransmits done before giving up.
47: */
48: #define RETRANSMIT_TRIES 5
49:
50: /**
51: * Maximum jitter in percent.
52: */
53: #define RETRANSMIT_JITTER_MAX 20
54:
55: /**
56: * Interval for mobike routability checks in ms.
57: */
58: #define ROUTABILITY_CHECK_INTERVAL 2500
59:
60: /**
61: * Number of routability checks before giving up
62: */
63: #define ROUTABILITY_CHECK_TRIES 10
64:
65: /**
66: * Type of task queues the task manager uses to handle tasks
67: */
68: enum task_queue_t {
69: /** tasks currently active, initiated by us */
70: TASK_QUEUE_ACTIVE,
71: /** passive tasks initiated by the remote peer */
72: TASK_QUEUE_PASSIVE,
73: /** tasks queued for initiated, but not yet activated */
74: TASK_QUEUE_QUEUED,
75: };
76:
77: /**
78: * The task manager, juggles task and handles message exchanges.
79: *
80: * On incoming requests, the task manager creates new tasks on demand and
81: * juggles the request through all available tasks. Each task inspects the
82: * request and adds payloads as necessary to the response.
83: * On outgoing requests, the task manager delivers the request through the tasks
84: * to build it, the response gets processed by each task to complete.
85: * The task manager has an internal Queue to store task which should get
86: * completed.
87: * For the initial IKE_SA setup, several tasks are queued: One for the
88: * unauthenticated IKE_SA setup, one for authentication, one for CHILD_SA setup
89: * and maybe one for virtual IP assignment.
90: * The task manager is also responsible for retransmission. It uses a backoff
91: * algorithm. The timeout is calculated using
92: * RETRANSMIT_TIMEOUT * (RETRANSMIT_BASE ** try).
93: * When try reaches RETRANSMIT_TRIES, retransmission is given up.
94: *
95: * Using an initial TIMEOUT of 4s, a BASE of 1.8, and 5 TRIES gives us:
96: * @verbatim
97: | relative | absolute
98: ---------------------------------------------------------
99: 4s * (1.8 ** 0) = 4s 4s
100: 4s * (1.8 ** 1) = 7s 11s
101: 4s * (1.8 ** 2) = 13s 24s
102: 4s * (1.8 ** 3) = 23s 47s
103: 4s * (1.8 ** 4) = 42s 89s
104: 4s * (1.8 ** 5) = 76s 165s
105:
106: @endverbatim
107: * The peer is considered dead after 2min 45s when no reply comes in.
108: */
109: struct task_manager_t {
110:
111: /**
112: * Process an incoming message.
113: *
114: * @param message message to add payloads to
115: * @return
116: * - DESTROY_ME if IKE_SA must be closed
117: * - SUCCESS otherwise
118: */
119: status_t (*process_message) (task_manager_t *this, message_t *message);
120:
121: /**
122: * Initiate an exchange with the currently queued tasks.
123: */
124: status_t (*initiate) (task_manager_t *this);
125:
126: /**
127: * Queue a task in the manager.
128: *
129: * @param task task to queue
130: */
131: void (*queue_task)(task_manager_t *this, task_t *task);
132:
133: /**
134: * Queue a task in the manager, but delay its initiation for at least the
135: * given number of seconds.
136: *
137: * @param task task to queue
138: * @param delay minimum delay in s before initiating the task
139: */
140: void (*queue_task_delayed)(task_manager_t *this, task_t *task,
141: uint32_t delay);
142:
143: /**
144: * Queue IKE_SA establishing tasks.
145: */
146: void (*queue_ike)(task_manager_t *this);
147:
148: /**
149: * Queue IKE_SA rekey tasks.
150: */
151: void (*queue_ike_rekey)(task_manager_t *this);
152:
153: /**
154: * Queue IKE_SA reauth tasks.
155: */
156: void (*queue_ike_reauth)(task_manager_t *this);
157:
158: /**
159: * Queue MOBIKE task
160: *
161: * @param roam TRUE to switch to new address
162: * @param address TRUE to include address list update
163: */
164: void (*queue_mobike)(task_manager_t *this, bool roam, bool address);
165:
166: /**
167: * Queue IKE_SA delete tasks.
168: */
169: void (*queue_ike_delete)(task_manager_t *this);
170:
171: /**
172: * Queue CHILD_SA establishing tasks.
173: *
174: * @param cfg CHILD_SA config to establish
175: * @param reqid reqid to use for CHILD_SA
176: * @param tsi initiator traffic selector, if packet-triggered
177: * @param tsr responder traffic selector, if packet-triggered
178: */
179: void (*queue_child)(task_manager_t *this, child_cfg_t *cfg, uint32_t reqid,
180: traffic_selector_t *tsi, traffic_selector_t *tsr);
181:
182: /**
183: * Queue CHILD_SA rekeying tasks.
184: *
185: * @param protocol CHILD_SA protocol, AH|ESP
186: * @param spi CHILD_SA SPI to rekey
187: */
188: void (*queue_child_rekey)(task_manager_t *this, protocol_id_t protocol,
189: uint32_t spi);
190:
191: /**
192: * Queue CHILD_SA delete tasks.
193: *
194: * @param protocol CHILD_SA protocol, AH|ESP
195: * @param spi CHILD_SA SPI to rekey
196: * @param expired TRUE if SA already expired
197: */
198: void (*queue_child_delete)(task_manager_t *this, protocol_id_t protocol,
199: uint32_t spi, bool expired);
200:
201: /**
202: * Queue liveness checking tasks.
203: */
204: void (*queue_dpd)(task_manager_t *this);
205:
206: /**
207: * Retransmit a request if it hasn't been acknowledged yet.
208: *
209: * A return value of INVALID_STATE means that the message was already
210: * acknowledged and has not to be retransmitted. A return value of SUCCESS
211: * means retransmission was required and the message has been resent.
212: *
213: * @param message_id ID of the message to retransmit
214: * @return
215: * - INVALID_STATE if retransmission not required
216: * - SUCCESS if retransmission sent
217: */
218: status_t (*retransmit) (task_manager_t *this, uint32_t message_id);
219:
220: /**
221: * Migrate all queued tasks from other to this.
222: *
223: * To rekey or reestablish an IKE_SA completely, all queued or active
224: * tasks should get migrated to the new IKE_SA.
225: *
226: * @param other manager which gives away its tasks
227: */
228: void (*adopt_tasks) (task_manager_t *this, task_manager_t *other);
229:
230: /**
231: * Increment a message ID counter, in- or outbound.
232: *
233: * If a message is processed outside of the manager, this call increments
234: * the message ID counters of the task manager.
235: *
236: * @param initiate TRUE to increment the initiating ID
237: */
238: void (*incr_mid)(task_manager_t *this, bool initiate);
239:
240: /**
241: * Get the current message ID counter, in- or outbound.
242: *
243: * @param initiate TRUE to get the initiating ID
244: * @return current message ID
245: */
246: uint32_t (*get_mid)(task_manager_t *this, bool initiate);
247:
248: /**
249: * Reset message ID counters of the task manager.
250: *
251: * The IKEv2 protocol requires to restart exchanges with message IDs
252: * reset to zero (INVALID_KE_PAYLOAD, COOKIES, ...). The reset() method
253: * resets the message IDs and resets all active tasks using the migrate()
254: * method.
255: * Use a value of UINT_MAX to keep the current message ID.
256: * For IKEv1, the arguments do not set the message ID, but the DPD sequence
257: * number counters.
258: *
259: * @param initiate message ID / DPD seq to initiate exchanges (send)
260: * @param respond message ID / DPD seq to respond to exchanges (expect)
261: */
262: void (*reset)(task_manager_t *this, uint32_t initiate, uint32_t respond);
263:
264: /**
265: * Check if we are currently waiting for a reply.
266: *
267: * @return TRUE if we are waiting, FALSE otherwise
268: */
269: bool (*busy) (task_manager_t *this);
270:
271: /**
272: * Create an enumerator over tasks in a specific queue.
273: *
274: * @param queue queue to create an enumerator over
275: * @return enumerator over task_t
276: */
277: enumerator_t* (*create_task_enumerator)(task_manager_t *this,
278: task_queue_t queue);
279:
280: /**
281: * Remove the task the given enumerator points to.
282: *
283: * @note This should be used with caution, in particular, for tasks in the
284: * active and passive queues.
285: *
286: * @param enumerator enumerator created with the method above
287: */
288: void (*remove_task)(task_manager_t *this, enumerator_t *enumerator);
289:
290: /**
291: * Flush all tasks, regardless of the queue.
292: */
293: void (*flush)(task_manager_t *this);
294:
295: /**
296: * Flush a queue, cancelling all tasks.
297: *
298: * @param queue queue to flush
299: */
300: void (*flush_queue)(task_manager_t *this, task_queue_t queue);
301:
302: /**
303: * Destroy the task_manager_t.
304: */
305: void (*destroy) (task_manager_t *this);
306: };
307:
308: /**
309: * Calculate total timeout of the retransmission mechanism.
310: *
311: * This is affected by modifications of retransmit_base, retransmit_timeout,
312: * retransmit_limit or retransmit_tries. The resulting value can then be used
313: * e.g. in kernel plugins to set the system's acquire timeout properly.
314: *
315: * @return calculated total retransmission timeout in seconds
316: */
317: u_int task_manager_total_retransmit_timeout();
318:
319: /**
320: * Create a task manager instance for the correct IKE version.
321: *
322: * @param ike_sa IKE_SA to create a task manager for
323: * @return task manager implementation for IKE version
324: */
325: task_manager_t *task_manager_create(ike_sa_t *ike_sa);
326:
327: #endif /** TASK_MANAGER_H_ @}*/
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