[people/ms/strongswan.git] / src / charon / charon / sa / ike_sa_manager.c

/**
 * @file ike_sa_manager.c
 *
 * @brief Implementation of ike_sa_mananger_t.
 *
 */

/*
 * Copyright (C) 2005 Jan Hutter, 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.
 */

#include <pthread.h>
#include <string.h>

#include "ike_sa_manager.h"

#include <daemon.h>
#include <sa/ike_sa_id.h>
#include <utils/logger.h>
#include <utils/logger_manager.h>
#include <utils/linked_list.h>

typedef struct ike_sa_entry_t ike_sa_entry_t;

/**
 * An entry in the linked list, contains IKE_SA, locking and lookup data.
 */
struct ike_sa_entry_t {
        /**
         * Destructor, also destroys associated ike_sa_t object.
         */
        status_t (*destroy) (ike_sa_entry_t *this);
        
        /**
         * Number of threads waiting for this ike_sa_t object.
         */
        int waiting_threads;
        
        /**
         * Condvar where threads can wait until ike_sa_t object is free for use again.
         */
        pthread_cond_t condvar;
        
        /**
         * Is this ike_sa currently checked out?
         */
        bool checked_out;
        
        /**
         * Does this SA drives out new threads?
         */
        bool driveout_new_threads;
        
        /**
         * Does this SA drives out waiting threads?
         */
        bool driveout_waiting_threads;
        
        /**
         * Identifiaction of an IKE_SA (SPIs).
         */
        ike_sa_id_t *ike_sa_id;
        
        /**
         * The contained ike_sa_t object.
         */
        ike_sa_t *ike_sa;
};

/**
 * Implementation of ike_sa_entry_t.destroy.
 */
static status_t ike_sa_entry_destroy(ike_sa_entry_t *this)
{
        /* also destroy IKE SA */
        this->ike_sa->destroy(this->ike_sa);
        this->ike_sa_id->destroy(this->ike_sa_id);
        free(this);
        return SUCCESS;
}

/**
 * @brief Creates a new entry for the ike_sa_t list.
 *
 * This constructor additionaly creates a new and empty SA.
 *
 * @param ike_sa_id             The associated ike_sa_id_t, will be cloned
 * @return                              ike_sa_entry_t object
 */
static ike_sa_entry_t *ike_sa_entry_create(ike_sa_id_t *ike_sa_id)
{
        ike_sa_entry_t *this = malloc_thing(ike_sa_entry_t);

        /* destroy function */
        this->destroy = ike_sa_entry_destroy;
        
        this->waiting_threads = 0;
        pthread_cond_init(&(this->condvar), NULL);
        
        /* we set checkout flag when we really give it out */
        this->checked_out = FALSE;
        this->driveout_new_threads = FALSE;
        this->driveout_waiting_threads = FALSE;
        
        /* ike_sa_id is always cloned */
        this->ike_sa_id = ike_sa_id->clone(ike_sa_id);

        /* create new ike_sa */
        this->ike_sa = ike_sa_create(ike_sa_id);

        return this;
}


typedef struct private_ike_sa_manager_t private_ike_sa_manager_t;

/**
 * Additional private members of ike_sa_manager_t.
 */
struct private_ike_sa_manager_t {
        /**
         * Public interface of ike_sa_manager_t.
         */
         ike_sa_manager_t public;

        /**
         * @brief Get next spi.
         *
         * We give out SPIs incremental starting at 1.
         * 
         * @param this                  the ike_sa_manager
         * @return                              the next spi
         */
        u_int64_t (*get_next_spi) (private_ike_sa_manager_t *this);

        /**
         * @brief Find the ike_sa_entry_t object in the list by SPIs.
         *
         * This function simply iterates over the linked list. A hash-table
         * would be more efficient when storing a lot of IKE_SAs...
         *
         * @param this                  calling object
         * @param ike_sa_id             id of the ike_sa, containing SPIs
         * @param[out] entry    pointer to set to the found entry
         * @return                              
         *                                              - SUCCESS when found,
         *                                              - NOT_FOUND when no such ike_sa_id in list
         */
         status_t (*get_entry_by_id) (private_ike_sa_manager_t *this, ike_sa_id_t *ike_sa_id, ike_sa_entry_t **entry);

         /**
         * @brief Find the ike_sa_entry_t in the list by pointer to SA.
         *
         * This function simply iterates over the linked list. A hash-table
         * would be more efficient when storing a lot of IKE_SAs...
         *
         * @param this                  calling object
         * @param ike_sa                pointer to the ike_sa
         * @param[out] entry    pointer to set to the found entry
         * @return                              
         *                                              - SUCCESS when found,
         *                                              - NOT_FOUND when no such ike_sa_id in list
         */
         status_t (*get_entry_by_sa) (private_ike_sa_manager_t *this, ike_sa_t *ike_sa, ike_sa_entry_t **entry);
         
         /**
          * @brief Felete an entry from the linked list.
          *
          * @param this                 calling object
          * @param entry                entry to delete
          * @return                             
          *                                     - SUCCESS when found,
          *                                     - NOT_FOUND when no such ike_sa_id in list
          */
         status_t (*delete_entry) (private_ike_sa_manager_t *this, ike_sa_entry_t *entry);

         /**
          * Lock for exclusivly accessing the manager.
          */
         pthread_mutex_t mutex;

         /**
          * Logger used for this IKE SA Manager.
          */
         logger_t *logger;

         /**
          * Linked list with entries for the ike_sa_t objects.
          */
         linked_list_t *ike_sa_list;
         
         /**
          * A randomizer, to get random SPIs for our side
          */
         randomizer_t *randomizer;
};

/**
 * Implementation of private_ike_sa_manager_t.get_entry_by_id.
 */
static status_t get_entry_by_id(private_ike_sa_manager_t *this, ike_sa_id_t *ike_sa_id, ike_sa_entry_t **entry)
{
        linked_list_t *list = this->ike_sa_list;
        iterator_t *iterator;
        status_t status;
        
        /* create iterator over list of ike_sa's */
        iterator = list->create_iterator(list, TRUE);

        /* default status */
        status = NOT_FOUND;
        
        while (iterator->has_next(iterator))
        {
                ike_sa_entry_t *current;
                
                iterator->current(iterator, (void**)&current);
                if (current->ike_sa_id->get_responder_spi(current->ike_sa_id) == 0)
                {
                        /* seems to be a half ready ike_sa */
                        if ((current->ike_sa_id->get_initiator_spi(current->ike_sa_id) == ike_sa_id->get_initiator_spi(ike_sa_id))
                                && (ike_sa_id->is_initiator(ike_sa_id) == current->ike_sa_id->is_initiator(current->ike_sa_id)))
                        {
                                this->logger->log(this->logger,CONTROL | LEVEL2,"Found entry by initiator spi %d",ike_sa_id->get_initiator_spi(ike_sa_id));
                                *entry = current;
                                status = SUCCESS;
                                break;
                        }
                }
                else if (ike_sa_id->get_responder_spi(ike_sa_id) == 0)
                {
                        if ((current->ike_sa_id->get_initiator_spi(current->ike_sa_id) == ike_sa_id->get_initiator_spi(ike_sa_id))
                                && (ike_sa_id->is_initiator(ike_sa_id) == current->ike_sa_id->is_initiator(current->ike_sa_id)))
                        {
                                this->logger->log(this->logger,CONTROL | LEVEL2,"Found entry by initiator spi %d",ike_sa_id->get_initiator_spi(ike_sa_id));
                                *entry = current;
                                status = SUCCESS;
                                break;
                        }                       
                }
                if (current->ike_sa_id->equals(current->ike_sa_id, ike_sa_id))
                {
                        this->logger->log(this->logger,CONTROL | LEVEL2,"Found entry by full ID");
                        *entry = current;
                        status = SUCCESS;
                        break;
                }
        }
        
        iterator->destroy(iterator);
        return status;
}

/**
 * Implementation of private_ike_sa_manager_t.get_entry_by_sa.
 */
static status_t get_entry_by_sa(private_ike_sa_manager_t *this, ike_sa_t *ike_sa, ike_sa_entry_t **entry)
{
        linked_list_t *list = this->ike_sa_list;
        iterator_t *iterator;
        status_t status;
        
        iterator = list->create_iterator(list, TRUE);
        
        /* default status */
        status = NOT_FOUND;
        
        while (iterator->has_next(iterator))
        {
                ike_sa_entry_t *current;
                iterator->current(iterator, (void**)&current);
                /* only pointers are compared */
                if (current->ike_sa == ike_sa)
                {
                        this->logger->log(this->logger,CONTROL | LEVEL2,"Found entry by pointer");
                        *entry = current;
                        status = SUCCESS;
                        break;
                }
        }
        iterator->destroy(iterator);
        
        return status;
}

/**
 * Implementation of private_ike_sa_manager_s.delete_entry.
 */
static status_t delete_entry(private_ike_sa_manager_t *this, ike_sa_entry_t *entry)
{
        linked_list_t *list = this->ike_sa_list;
        iterator_t *iterator;
        status_t status;
        
        iterator = list->create_iterator(list, TRUE);

        status = NOT_FOUND;     
        
        while (iterator->has_next(iterator))
        {
                ike_sa_entry_t *current;
                iterator->current(iterator, (void**)&current);
                if (current == entry) 
                {
                        this->logger->log(this->logger,CONTROL | LEVEL2,"Found entry by pointer. Going to delete it.");
                        iterator->remove(iterator);
                        entry->destroy(entry);
                        status = SUCCESS;
                        break;
                }
        }
        iterator->destroy(iterator);
        return status;  
}


/**
 * Implementation of private_ike_sa_manager_t.get_next_spi.
 */
static u_int64_t get_next_spi(private_ike_sa_manager_t *this)
{
        u_int64_t spi;
        
        this->randomizer->get_pseudo_random_bytes(this->randomizer, 8, (u_int8_t*)&spi);
        
        return spi;
}

/**
 * Implementation of of ike_sa_manager.create_and_checkout.
 */
static void create_and_checkout(private_ike_sa_manager_t *this,ike_sa_t **ike_sa)
{
        u_int64_t initiator_spi;
        ike_sa_entry_t *new_ike_sa_entry;
        ike_sa_id_t *new_ike_sa_id;

        initiator_spi = this->get_next_spi(this);
        new_ike_sa_id = ike_sa_id_create(0, 0, TRUE);
        new_ike_sa_id->set_initiator_spi(new_ike_sa_id, initiator_spi);

        /* create entry */
        new_ike_sa_entry = ike_sa_entry_create(new_ike_sa_id);
        new_ike_sa_id->destroy(new_ike_sa_id);

        /* each access is locked */
        pthread_mutex_lock(&(this->mutex));
        
        this->ike_sa_list->insert_last(this->ike_sa_list, new_ike_sa_entry);

        /* check ike_sa out */
        this->logger->log(this->logger,CONTROL | LEVEL1 ,"New IKE_SA created and added to list of known IKE_SA's");
        new_ike_sa_entry->checked_out = TRUE;
        *ike_sa = new_ike_sa_entry->ike_sa;

        pthread_mutex_unlock(&(this->mutex));
}

/**
 * Implementation of of ike_sa_manager.checkout.
 */
static status_t checkout(private_ike_sa_manager_t *this, ike_sa_id_t *ike_sa_id, ike_sa_t **ike_sa)
{
        bool responder_spi_set;
        bool initiator_spi_set;
        bool original_initiator;
        status_t retval;
        
        /* each access is locked */
        pthread_mutex_lock(&(this->mutex));
        
        responder_spi_set = (FALSE != ike_sa_id->get_responder_spi(ike_sa_id));
        initiator_spi_set = (FALSE != ike_sa_id->get_initiator_spi(ike_sa_id));
        original_initiator = ike_sa_id->is_initiator(ike_sa_id);
        
        if ((initiator_spi_set && responder_spi_set) ||
                ((initiator_spi_set && !responder_spi_set) && (original_initiator)))
        {
                /* we SHOULD have an IKE_SA for these SPIs in the list,
                 * if not, we can't handle the request...
                 */
                 ike_sa_entry_t *entry;
                 /* look for the entry */
                 if (this->get_entry_by_id(this, ike_sa_id, &entry) == SUCCESS)
                 {
                        /* can we give this ike_sa out to new requesters?*/
                        if (entry->driveout_new_threads)
                        {
                                this->logger->log(this->logger,CONTROL|LEVEL1,"Drive out new thread for existing IKE_SA");
                                /* no we can't */
                                retval = NOT_FOUND;
                        }
                        else
                        {
                                /* is this IKE_SA already checked out ?? 
                                 * are we welcome to get this SA ? */
                                while (entry->checked_out && !entry->driveout_waiting_threads)  
                                { 
                                        /* so wait until we can get it for us.
                                         * we register us as waiting.
                                         */
                                        entry->waiting_threads++;
                                        pthread_cond_wait(&(entry->condvar), &(this->mutex));
                                        entry->waiting_threads--;
                                }
                                
                                /* hm, a deletion request forbids us to get this SA, go home */
                                if (entry->driveout_waiting_threads)
                                {
                                        /* we must signal here, others are interested that we leave */
                                        pthread_cond_signal(&(entry->condvar));
                                        this->logger->log(this->logger,CONTROL|LEVEL1,"Drive out waiting thread for existing IKE_SA");
                                        retval = NOT_FOUND;
                                }
                                else
                                {
                                        this->logger->log(this->logger,CONTROL|LEVEL2,"IKE SA successfully checked out");
                                        /* ok, this IKE_SA is finally ours */
                                        entry->checked_out = TRUE;
                                        *ike_sa = entry->ike_sa;
                                        /* DON'T use return, we must unlock the mutex! */
                                        retval = SUCCESS; 
                                }
                        }
                }
                else
                {
                        this->logger->log(this->logger,ERROR | LEVEL1,"IKE SA not stored in known IKE_SA list");
                        /* looks like there is no such IKE_SA, better luck next time... */
                        /* DON'T use return, we must unlock the mutex! */
                        retval = NOT_FOUND;
                }
        }
        else if ((initiator_spi_set && !responder_spi_set) && (!original_initiator))
        {
                /* an IKE_SA_INIT from an another endpoint,
                 * he is the initiator.
                 * For simplicity, we do NOT check for retransmitted
                 * IKE_SA_INIT-Requests here, so EVERY single IKE_SA_INIT-
                 * Request (even a retransmitted one) will result in a
                 * IKE_SA. This could be improved...
                 */
                u_int64_t responder_spi;
                ike_sa_entry_t *new_ike_sa_entry;
                
                
                /* set SPIs, we are the responder */
                responder_spi = this->get_next_spi(this);
                
                /* we also set arguments spi, so its still valid */
                ike_sa_id->set_responder_spi(ike_sa_id, responder_spi);
                
                /* create entry */
                new_ike_sa_entry = ike_sa_entry_create(ike_sa_id);
                
                this->ike_sa_list->insert_last(this->ike_sa_list, new_ike_sa_entry);
                
                /* check ike_sa out */
                this->logger->log(this->logger,CONTROL | LEVEL1 ,"IKE_SA added to list of known IKE_SA's");
                new_ike_sa_entry->checked_out = TRUE;
                *ike_sa = new_ike_sa_entry->ike_sa;
                
                retval = CREATED;
        }
        else
        {
                /* responder set, initiator not: here is something seriously wrong! */
                this->logger->log(this->logger,ERROR | LEVEL1, "Invalid IKE_SA SPI's");
                /* DON'T use return, we must unlock the mutex! */
                retval = INVALID_ARG;
        }

        pthread_mutex_unlock(&(this->mutex));
        /* OK, unlocked... */
        return retval;
}

/**
 * Implementation of of ike_sa_manager.checkout_by_hosts.
 */
static status_t checkout_by_hosts(private_ike_sa_manager_t *this, host_t *me, host_t *other, ike_sa_t **ike_sa)
{
        iterator_t *iterator;
        ike_sa_id_t *ike_sa_id = NULL;
        
        pthread_mutex_lock(&(this->mutex));
        
        iterator = this->ike_sa_list->create_iterator(this->ike_sa_list, TRUE);
        while (iterator->has_next(iterator))
        {
                ike_sa_entry_t *current;
                host_t *sa_me, *sa_other;
                
                iterator->current(iterator, (void**)&current);
                sa_me = current->ike_sa->get_my_host(current->ike_sa);
                sa_other = current->ike_sa->get_other_host(current->ike_sa);
                
                /* one end may be default/any, but not both */
                if (me->is_default_route(me))
                {
                        if (other->is_default_route(other))
                        {
                                break;
                        }
                        if (other->equals(other, sa_other))
                        {
                                /* other matches */
                                ike_sa_id = current->ike_sa_id;
                        }
                }
                else if (other->is_default_route(other))
                {
                        if (me->equals(me, sa_me))
                        {
                                /* ME matches */
                                ike_sa_id = current->ike_sa_id;
                        }
                }
                else
                {
                        if (me->equals(me, sa_me) && other->equals(other, sa_other))
                        {
                                /* both matches */
                                ike_sa_id = current->ike_sa_id;
                        }
                }
        }
        iterator->destroy(iterator);
        pthread_mutex_unlock(&(this->mutex));
        
        if (ike_sa_id)
        {
                /* checkout is done in the checkout function, since its rather complex */
                return checkout(this, ike_sa_id, ike_sa);
        }
        return NOT_FOUND;
}

/**
 * Implementation of ike_sa_manager_t.get_ike_sa_list.
 */
linked_list_t *get_ike_sa_list(private_ike_sa_manager_t* this)
{
        linked_list_t *list;
        iterator_t *iterator;
        
        pthread_mutex_lock(&(this->mutex));
        
        list = linked_list_create();
        iterator = this->ike_sa_list->create_iterator(this->ike_sa_list, TRUE);
        while (iterator->has_next(iterator))
        {
                ike_sa_entry_t *entry;
                iterator->current(iterator, (void**)&entry);
                list->insert_last(list, (void*)entry->ike_sa_id->clone(entry->ike_sa_id));
        }
        iterator->destroy(iterator);
        
        pthread_mutex_unlock(&(this->mutex));
        return list;
}

/**
 * Implementation of ike_sa_manager_t.get_ike_sa_list_by_name.
 */
linked_list_t *get_ike_sa_list_by_name(private_ike_sa_manager_t* this, const char *name)
{
        linked_list_t *list;
        iterator_t *iterator;
        
        pthread_mutex_lock(&(this->mutex));
        
        list = linked_list_create();
        iterator = this->ike_sa_list->create_iterator(this->ike_sa_list, TRUE);
        while (iterator->has_next(iterator))
        {
                ike_sa_entry_t *entry;
                connection_t *connection;
                
                iterator->current(iterator, (void**)&entry);
                connection = entry->ike_sa->get_connection(entry->ike_sa);
                if (strcmp(name, connection->get_name(connection)) == 0)
                {
                        list->insert_last(list, (void*)entry->ike_sa_id->clone(entry->ike_sa_id));
                }
        }
        iterator->destroy(iterator);
        
        pthread_mutex_unlock(&(this->mutex));
        return list;
}

/**
 * Implementation of ike_sa_manager_t.log_status.
 */
static void log_status(private_ike_sa_manager_t* this, logger_t* logger, char* name)
{
        iterator_t *iterator;
        
        pthread_mutex_lock(&(this->mutex));
        
        iterator = this->ike_sa_list->create_iterator(this->ike_sa_list, TRUE);
        while (iterator->has_next(iterator))
        {
                ike_sa_entry_t *entry;
                iterator->current(iterator, (void**)&entry);
                entry->ike_sa->log_status(entry->ike_sa, logger, name);
        }
        iterator->destroy(iterator);
        
        pthread_mutex_unlock(&(this->mutex));
}

/**
 * Implementation of ike_sa_manager_t.checkin.
 */
static status_t checkin(private_ike_sa_manager_t *this, ike_sa_t *ike_sa)
{
        /* to check the SA back in, we look for the pointer of the ike_sa
         * in all entries.
         * We can't search by SPI's since the MAY have changed (e.g. on reception
         * of a IKE_SA_INIT response). Updating of the SPI MAY be necessary...
         */
        status_t retval;
        ike_sa_entry_t *entry;
        
        pthread_mutex_lock(&(this->mutex));

        /* look for the entry */
        if (this->get_entry_by_sa(this, ike_sa, &entry) == SUCCESS)
        {
                /* ike_sa_id must be updated */
                entry->ike_sa_id->replace_values(entry->ike_sa_id, ike_sa->get_id(ike_sa));
                /* signal waiting threads */
                entry->checked_out = FALSE;
                this->logger->log(this->logger,CONTROL | LEVEL1,"Checkin of IKE_SA successful.");
                pthread_cond_signal(&(entry->condvar));
                retval = SUCCESS;
        }
        else
        {
                this->logger->log(this->logger,ERROR,"Fatal Error: Tried to checkin nonexisting IKE_SA");
                /* this SA is no more, this REALLY should not happen */
                retval = NOT_FOUND;
        }
        pthread_mutex_unlock(&(this->mutex));
        return retval;
}


/**
 * Implementation of ike_sa_manager_t.checkin_and_delete.
 */
static status_t checkin_and_delete(private_ike_sa_manager_t *this, ike_sa_t *ike_sa)
{
        /* deletion is a bit complex, we must garant that no thread is waiting for
         * this SA.
         * We take this SA from the list, and start signaling while threads
         * are in the condvar.
         */
        ike_sa_entry_t *entry;
        status_t retval;

        pthread_mutex_lock(&(this->mutex));

        if (this->get_entry_by_sa(this, ike_sa, &entry) == SUCCESS)
        {
                /* mark it, so now new threads can acquire this SA */
                entry->driveout_new_threads = TRUE;
                /* additionaly, drive out waiting threads */
                entry->driveout_waiting_threads = TRUE;

                /* wait until all workers have done their work */
                while (entry->waiting_threads > 0)
                {
                        /* let the other threads do some work*/
                        pthread_cond_signal(&(entry->condvar));
                        /* and the nice thing, they will wake us again when their work is done */
                        pthread_cond_wait(&(entry->condvar), &(this->mutex));
                }
                /* ok, we are alone now, no threads waiting in the entry's condvar */
                this->delete_entry(this, entry);
                this->logger->log(this->logger,CONTROL | LEVEL1,"Checkin and delete of IKE_SA successful");
                retval = SUCCESS;
        }
        else
        {
                this->logger->log(this->logger,ERROR,"Fatal Error: Tried to checkin and delete nonexisting IKE_SA");
                retval = NOT_FOUND;
        }
        
        pthread_mutex_unlock(&(this->mutex));
        return retval;
}

/**
 * Implementation of ike_sa_manager_t.delete.
 */
static status_t delete(private_ike_sa_manager_t *this, ike_sa_id_t *ike_sa_id)
{
        /* deletion is a bit complex, we must garant that no thread is waiting for
         * this SA.
         * We take this SA from the list, and start signaling while threads
         * are in the condvar.
         */
        ike_sa_entry_t *entry;
        status_t retval;

        pthread_mutex_lock(&(this->mutex));

        if (this->get_entry_by_id(this, ike_sa_id, &entry) == SUCCESS)
        {
                /* mark it, so now new threads can acquire this SA */
                entry->driveout_new_threads = TRUE;

                /* wait until all workers have done their work */
                while (entry->waiting_threads)
                {
                        /* wake up all */
                        pthread_cond_signal(&(entry->condvar));
                        /* and the nice thing, they will wake us again when their work is done */
                        pthread_cond_wait(&(entry->condvar), &(this->mutex));
                }
                /* ok, we are alone now, no threads waiting in the entry's condvar */
                this->delete_entry(this, entry);
                this->logger->log(this->logger,CONTROL | LEVEL1,"Delete of IKE_SA successful");
                retval = SUCCESS;
        }
        else
        {
                this->logger->log(this->logger,ERROR,"Fatal Error: Tried to delete nonexisting IKE_SA");
                retval = NOT_FOUND;
        }

        pthread_mutex_unlock(&(this->mutex));
        return retval;
}

/**
 * Implementation of ike_sa_manager_t.destroy.
 */
static void destroy(private_ike_sa_manager_t *this)
{
        /* destroy all list entries */
        linked_list_t *list = this->ike_sa_list;
        iterator_t *iterator;
        ike_sa_entry_t *entry;
        
        pthread_mutex_lock(&(this->mutex));
        
        this->logger->log(this->logger,CONTROL | LEVEL1,"Going to destroy IKE_SA manager and all managed IKE_SA's");
        
        /* Step 1: drive out all waiting threads  */
        iterator = list->create_iterator(list, TRUE);

        this->logger->log(this->logger,CONTROL | LEVEL2,"Set driveout flags for all stored IKE_SA's");
        while (iterator->has_next(iterator))
        {
                iterator->current(iterator, (void**)&entry);
                /* do not accept new threads, drive out waiting threads */
                entry->driveout_new_threads = TRUE;
                entry->driveout_waiting_threads = TRUE; 
        }

        this->logger->log(this->logger,CONTROL | LEVEL2,"Wait for all threads to leave IKE_SA's");
        /* Step 2: wait until all are gone */
        iterator->reset(iterator);
        while (iterator->has_next(iterator))
        {
                iterator->current(iterator, (void**)&entry);
                while (entry->waiting_threads)
                {
                        /* wake up all */
                        pthread_cond_signal(&(entry->condvar));
                        /* go sleeping until they are gone */
                        pthread_cond_wait(&(entry->condvar), &(this->mutex));           
                }
        }
        this->logger->log(this->logger,CONTROL | LEVEL2,"Delete all IKE_SA's");
        /* Step 3: delete all entries */
        iterator->destroy(iterator);

        while (list->get_count(list) > 0)
        {
                list->get_first(list, (void**)&entry);
                this->delete_entry(this, entry);
        }
        list->destroy(list);
        this->logger->log(this->logger,CONTROL | LEVEL2,"IKE_SA's deleted");
        pthread_mutex_unlock(&(this->mutex));
        
        this->randomizer->destroy(this->randomizer);
        
        free(this);
}

/*
 * Described in header.
 */
ike_sa_manager_t *ike_sa_manager_create()
{
        private_ike_sa_manager_t *this = malloc_thing(private_ike_sa_manager_t);

        /* assign public functions */
        this->public.destroy = (void(*)(ike_sa_manager_t*))destroy;
        this->public.create_and_checkout = (void(*)(ike_sa_manager_t*,ike_sa_t**))create_and_checkout;
        this->public.checkout = (status_t(*)(ike_sa_manager_t*, ike_sa_id_t*,ike_sa_t**))checkout;
        this->public.checkout_by_hosts = (status_t(*)(ike_sa_manager_t*,host_t*,host_t*,ike_sa_t**))checkout_by_hosts;
        this->public.get_ike_sa_list = (linked_list_t*(*)(ike_sa_manager_t*))get_ike_sa_list;
        this->public.get_ike_sa_list_by_name = (linked_list_t*(*)(ike_sa_manager_t*,const char*))get_ike_sa_list_by_name;
        this->public.log_status = (void(*)(ike_sa_manager_t*,logger_t*,char*))log_status;
        this->public.checkin = (status_t(*)(ike_sa_manager_t*,ike_sa_t*))checkin;
        this->public.delete = (status_t(*)(ike_sa_manager_t*,ike_sa_id_t*))delete;
        this->public.checkin_and_delete = (status_t(*)(ike_sa_manager_t*,ike_sa_t*))checkin_and_delete;

        /* initialize private functions */
        this->get_next_spi = get_next_spi;
        this->get_entry_by_sa = get_entry_by_sa;
        this->get_entry_by_id = get_entry_by_id;
        this->delete_entry = delete_entry;

        /* initialize private variables */
        this->logger = logger_manager->get_logger(logger_manager, IKE_SA_MANAGER);
        
        this->ike_sa_list = linked_list_create();

        pthread_mutex_init(&(this->mutex), NULL);

        this->randomizer = randomizer_create();

        return (ike_sa_manager_t*)this;
}