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/*
* Copyright (C) 2005-2006 Martin Willi
* Copyright (C) 2005 Jan Hutter
* 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.
*
* $Id: ike_sa_manager.h 4624 2008-11-11 13:11:44Z tobias $
*/
/**
* @defgroup ike_sa_manager ike_sa_manager
* @{ @ingroup sa
*/
#ifndef IKE_SA_MANAGER_H_
#define IKE_SA_MANAGER_H_
typedef struct ike_sa_manager_t ike_sa_manager_t;
#include <library.h>
#include <sa/ike_sa.h>
#include <encoding/message.h>
#include <config/peer_cfg.h>
/**
* The IKE_SA-Manager is responsible for managing all initiated and responded IKE_SA's.
*
* To avoid access from multiple threads, IKE_SAs must be checked out from
* the manager, and checked in after usage.
* The manager also handles deletion of SAs.
*
* @todo checking of double-checkouts from the same threads would be nice.
* This could be done by comparing thread-ids via pthread_self()...
*
* @todo Managing of ike_sa_t objects in a hash table instead of linked list.
*/
struct ike_sa_manager_t {
/**
* Checkout an existing IKE_SA.
*
* @param ike_sa_id the SA identifier, will be updated
* @returns
* - checked out IKE_SA if found
* - NULL, if specified IKE_SA is not found.
*/
ike_sa_t* (*checkout) (ike_sa_manager_t* this, ike_sa_id_t *sa_id);
/**
* Create and check out a new IKE_SA.
*
* @param initiator TRUE for initiator, FALSE otherwise
* @returns created and checked out IKE_SA
*/
ike_sa_t* (*checkout_new) (ike_sa_manager_t* this, bool initiator);
/**
* Checkout an IKE_SA by a message.
*
* In some situations, it is necessary that the manager knows the
* message to use for the checkout. This has the following reasons:
*
* 1. If the targeted IKE_SA is already processing a message, we do not
* check it out if the message ID is the same.
* 2. If it is an IKE_SA_INIT request, we have to check if it is a
* retransmission. If so, we have to drop the message, we would
* create another unneeded IKE_SA for each retransmitted packet.
*
* A call to checkout_by_message() returns a (maybe new created) IKE_SA.
* If processing the message does not make sense (for the reasons above),
* NULL is returned.
*
* @param ike_sa_id the SA identifier, will be updated
* @returns
* - checked out/created IKE_SA
* - NULL to not process message further
*/
ike_sa_t* (*checkout_by_message) (ike_sa_manager_t* this, message_t *message);
/**
* Checkout an IKE_SA for initiation by a peer_config.
*
* To initiate, a CHILD_SA may be established within an existing IKE_SA.
* This call checks for an existing IKE_SA by comparing the configuration.
* If the CHILD_SA can be created in an existing IKE_SA, the matching SA
* is returned.
* If no IKE_SA is found, a new one is created. This is also the case when
* the found IKE_SA is in the DELETING state.
*
* @param peer_cfg configuration used to find an existing IKE_SA
* @return checked out/created IKE_SA
*/
ike_sa_t* (*checkout_by_config) (ike_sa_manager_t* this,
peer_cfg_t *peer_cfg);
/**
* Check out a duplicate if ike_sa to do uniqueness tests.
*
* @param ike_sa ike_sa to get a duplicate from
* @return checked out duplicate
*/
ike_sa_t* (*checkout_duplicate)(ike_sa_manager_t *this, ike_sa_t *ike_sa);
/**
* Check out an IKE_SA a unique ID.
*
* Every IKE_SA and every CHILD_SA is uniquely identified by an ID.
* These checkout function uses, depending
* on the child parameter, the unique ID of the IKE_SA or the reqid
* of one of a IKE_SAs CHILD_SA.
*
* @param id unique ID of the object
* @param child TRUE to use CHILD, FALSE to use IKE_SA
* @return
* - checked out IKE_SA, if found
* - NULL, if not found
*/
ike_sa_t* (*checkout_by_id) (ike_sa_manager_t* this, u_int32_t id,
bool child);
/**
* Check out an IKE_SA by the policy/connection name.
*
* Check out the IKE_SA by the connections name or by a CHILD_SAs policy
* name.
*
* @param name name of the connection/policy
* @param child TRUE to use policy name, FALSE to use conn name
* @return
* - checked out IKE_SA, if found
* - NULL, if not found
*/
ike_sa_t* (*checkout_by_name) (ike_sa_manager_t* this, char *name,
bool child);
/**
* Create an enumerator over all stored IKE_SAs.
*
* The avoid synchronization issues, the enumerator locks access
* to the manager exclusively, until it gets destroyed.
*
* @return enumerator over all IKE_SAs.
*/
enumerator_t *(*create_enumerator) (ike_sa_manager_t* this);
/**
* Checkin the SA after usage.
*
* @warning the SA pointer MUST NOT be used after checkin!
* The SA must be checked out again!
*
* @param ike_sa_id the SA identifier, will be updated
* @param ike_sa checked out SA
* @returns
* - SUCCESS if checked in
* - NOT_FOUND when not found (shouldn't happen!)
*/
status_t (*checkin) (ike_sa_manager_t* this, ike_sa_t *ike_sa);
/**
* Destroy a checked out SA.
*
* The IKE SA is destroyed without notification of the remote peer.
* Use this only if the other peer doesn't respond or behaves not
* as predicted.
* Checking in and destruction is an atomic operation (for the IKE_SA),
* so this can be called if the SA is in a "unclean" state, without the
* risk that another thread can get the SA.
*
* @param ike_sa SA to delete
* @returns
* - SUCCESS if found
* - NOT_FOUND when no such SA is available
*/
status_t (*checkin_and_destroy) (ike_sa_manager_t* this, ike_sa_t *ike_sa);
/**
* Get the number of IKE_SAs which are in the connecting state.
*
* To prevent the server from resource exhaustion, cookies and other
* mechanisms are used. The number of half open IKE_SAs is a good
* indicator to see if a peer is flooding the server.
* If a host is supplied, only the number of half open IKE_SAs initiated
* from this IP are counted.
* Only SAs for which we are the responder are counted.
*
* @param ip NULL for all, IP for half open IKE_SAs with IP
* @return number of half open IKE_SAs
*/
int (*get_half_open_count) (ike_sa_manager_t *this, host_t *ip);
/**
* Delete all existing IKE_SAs and destroy them immediately.
*
* Threads will be driven out, so all SAs can be deleted cleanly.
*/
void (*flush)(ike_sa_manager_t *this);
/**
* Destroys the manager with all associated SAs.
*
* A call to flush() is required before calling destroy.
*/
void (*destroy) (ike_sa_manager_t *this);
};
/**
* Create a manager.
*
* @returns ike_sa_manager_t object, NULL if initialization fails
*/
ike_sa_manager_t *ike_sa_manager_create(void);
#endif /*IKE_SA_MANAGER_H_ @} */
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