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Diffstat (limited to 'src/libcharon/sa/task_manager.h')
| -rw-r--r-- | src/libcharon/sa/task_manager.h | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/src/libcharon/sa/task_manager.h b/src/libcharon/sa/task_manager.h new file mode 100644 index 000000000..731ed4898 --- /dev/null +++ b/src/libcharon/sa/task_manager.h @@ -0,0 +1,173 @@ +/* + * Copyright (C) 2006 Martin Willi + * Hochschule fuer Technik Rapperswil + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + */ + +/** + * @defgroup task_manager task_manager + * @{ @ingroup sa + */ + +#ifndef TASK_MANAGER_H_ +#define TASK_MANAGER_H_ + +typedef struct task_manager_t task_manager_t; + +#include <limits.h> + +#include <library.h> +#include <encoding/message.h> +#include <sa/ike_sa.h> +#include <sa/tasks/task.h> + +/** + * First retransmit timeout in seconds. + */ +#define RETRANSMIT_TIMEOUT 4.0 + +/** + * Base which is raised to the power of the retransmission try. + */ +#define RETRANSMIT_BASE 1.8 + +/** + * Number of retransmits done before giving up. + */ +#define RETRANSMIT_TRIES 5 + +/** + * Interval for mobike routability checks in ms. + */ +#define ROUTEABILITY_CHECK_INTERVAL 2500 + +/** + * Number of routability checks before giving up + */ +#define ROUTEABILITY_CHECK_TRIES 10 + + +/** + * The task manager, juggles task and handles message exchanges. + * + * On incoming requests, the task manager creates new tasks on demand and + * juggles the request through all available tasks. Each task inspects the + * request and adds payloads as necessary to the response. + * On outgoing requests, the task manager delivers the request through the tasks + * to build it, the response gets processed by each task to complete. + * The task manager has an internal Queue to store task which should get + * completed. + * For the initial IKE_SA setup, several tasks are queued: One for the + * unauthenticated IKE_SA setup, one for authentication, one for CHILD_SA setup + * and maybe one for virtual IP assignement. + * The task manager is also responsible for retransmission. It uses a backoff + * algorithm. The timeout is calculated using + * RETRANSMIT_TIMEOUT * (RETRANSMIT_BASE ** try). + * When try reaches RETRANSMIT_TRIES, retransmission is given up. + * + * Using an initial TIMEOUT of 4s, a BASE of 1.8, and 5 TRIES gives us: + * @verbatim + | relative | absolute + --------------------------------------------------------- + 4s * (1.8 ** 0) = 4s 4s + 4s * (1.8 ** 1) = 7s 11s + 4s * (1.8 ** 2) = 13s 24s + 4s * (1.8 ** 3) = 23s 47s + 4s * (1.8 ** 4) = 42s 89s + 4s * (1.8 ** 5) = 76s 165s + + @endverbatim + * The peer is considered dead after 2min 45s when no reply comes in. + */ +struct task_manager_t { + + /** + * Process an incoming message. + * + * @param message message to add payloads to + * @return + * - DESTROY_ME if IKE_SA must be closed + * - SUCCESS otherwise + */ + status_t (*process_message) (task_manager_t *this, message_t *message); + + /** + * Initiate an exchange with the currently queued tasks. + */ + status_t (*initiate) (task_manager_t *this); + + /** + * Queue a task in the manager. + * + * @param task task to queue + */ + void (*queue_task) (task_manager_t *this, task_t *task); + + /** + * Retransmit a request if it hasn't been acknowledged yet. + * + * A return value of INVALID_STATE means that the message was already + * acknowledged and has not to be retransmitted. A return value of SUCCESS + * means retransmission was required and the message has been resent. + * + * @param message_id ID of the message to retransmit + * @return + * - INVALID_STATE if retransmission not required + * - SUCCESS if retransmission sent + */ + status_t (*retransmit) (task_manager_t *this, u_int32_t message_id); + + /** + * Migrate all tasks from other to this. + * + * To rekey or reestablish an IKE_SA completely, all queued or active + * tasks should get migrated to the new IKE_SA. + * + * @param other manager which gives away its tasks + */ + void (*adopt_tasks) (task_manager_t *this, task_manager_t *other); + + /** + * Reset message ID counters of the task manager. + * + * The IKEv2 protocol requires to restart exchanges with message IDs + * reset to zero (INVALID_KE_PAYLOAD, COOKIES, ...). The reset() method + * resets the message IDs and resets all active tasks using the migrate() + * method. + * Use a value of UINT_MAX to keep the current message ID. + * + * @param initiate message ID to initiate exchanges (send) + * @param respond message ID to respond to exchanges (expect) + */ + void (*reset) (task_manager_t *this, u_int32_t initiate, u_int32_t respond); + + /** + * Check if we are currently waiting for a reply. + * + * @return TRUE if we are waiting, FALSE otherwise + */ + bool (*busy) (task_manager_t *this); + + /** + * Destroy the task_manager_t. + */ + void (*destroy) (task_manager_t *this); +}; + +/** + * Create an instance of the task manager. + * + * @param ike_sa IKE_SA to manage. + */ +task_manager_t *task_manager_create(ike_sa_t *ike_sa); + +#endif /** TASK_MANAGER_H_ @}*/ |