adding new virtual ip before deleting old one to keep IP on reauthentication

[strongswan.git] / src / charon / sa / ike_sa.c

/**
 * @file ike_sa.c
 *
 * @brief Implementation of ike_sa_t.
 *
 */

/*
 * Copyright (C) 2006-2007 Tobias Brunner
 * Copyright (C) 2006 Daniel Roethlisberger
 * 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.
 */

#include <sys/time.h>
#include <string.h>
#include <printf.h>
#include <sys/stat.h>
#include <errno.h>

#include "ike_sa.h"

#include <library.h>
#include <daemon.h>
#include <utils/linked_list.h>
#include <utils/lexparser.h>
#include <crypto/diffie_hellman.h>
#include <crypto/prf_plus.h>
#include <crypto/crypters/crypter.h>
#include <crypto/hashers/hasher.h>
#include <encoding/payloads/sa_payload.h>
#include <encoding/payloads/nonce_payload.h>
#include <encoding/payloads/ke_payload.h>
#include <encoding/payloads/delete_payload.h>
#include <encoding/payloads/transform_substructure.h>
#include <encoding/payloads/transform_attribute.h>
#include <encoding/payloads/ts_payload.h>
#include <sa/task_manager.h>
#include <sa/tasks/ike_init.h>
#include <sa/tasks/ike_natd.h>
#include <sa/tasks/ike_mobike.h>
#include <sa/tasks/ike_auth.h>
#include <sa/tasks/ike_config.h>
#include <sa/tasks/ike_cert.h>
#include <sa/tasks/ike_rekey.h>
#include <sa/tasks/ike_reauth.h>
#include <sa/tasks/ike_delete.h>
#include <sa/tasks/ike_dpd.h>
#include <sa/tasks/child_create.h>
#include <sa/tasks/child_delete.h>
#include <sa/tasks/child_rekey.h>
#include <processing/jobs/retransmit_job.h>
#include <processing/jobs/delete_ike_sa_job.h>
#include <processing/jobs/send_dpd_job.h>
#include <processing/jobs/send_keepalive_job.h>
#include <processing/jobs/rekey_ike_sa_job.h>

#ifdef P2P
#include <sa/tasks/ike_p2p.h>
#endif

#ifndef RESOLV_CONF
#define RESOLV_CONF "/etc/resolv.conf"
#endif

ENUM(ike_sa_state_names, IKE_CREATED, IKE_DELETING,
        "CREATED",
        "CONNECTING",
        "ESTABLISHED",
        "REKEYING",
        "DELETING",
);

typedef struct private_ike_sa_t private_ike_sa_t;

/**
 * Private data of an ike_sa_t object.
 */
struct private_ike_sa_t {

        /**
         * Public members
         */
        ike_sa_t public;

        /**
         * Identifier for the current IKE_SA.
         */
        ike_sa_id_t *ike_sa_id;
        
        /**
         * unique numerical ID for this IKE_SA.
         */
        u_int32_t unique_id;
        
        /**
         * Current state of the IKE_SA
         */
        ike_sa_state_t state;   
        
        /**
         * IKE configuration used to set up this IKE_SA
         */
        ike_cfg_t *ike_cfg;
        
        /**
         * Peer and authentication information to establish IKE_SA.
         */
        peer_cfg_t *peer_cfg;
        
        /**
         * Juggles tasks to process messages
         */
        task_manager_t *task_manager;
        
        /**
         * Address of local host
         */
        host_t *my_host;
        
        /**
         * Address of remote host
         */
        host_t *other_host;
        
#ifdef P2P      
        /**
         * Server reflexive host
         */
        host_t *server_reflexive_host;
#endif /* P2P */
                
        /**
         * Identification used for us
         */
        identification_t *my_id;
        
        /**
         * Identification used for other
         */
        identification_t *other_id;
        
        /**
         * CA that issued the certificate of other
         */
        ca_info_t *other_ca;
        
        /**
         * set of extensions the peer supports
         */
        ike_extension_t extensions;
        
        /**
         * set of condition flags currently enabled for this IKE_SA
         */
        ike_condition_t conditions;

        /**
         * Linked List containing the child sa's of the current IKE_SA.
         */
        linked_list_t *child_sas;
        
        /**
         * crypter for inbound traffic
         */
        crypter_t *crypter_in;
        
        /**
         * crypter for outbound traffic
         */
        crypter_t *crypter_out;
        
        /**
         * Signer for inbound traffic
         */
        signer_t *signer_in;
        
        /**
         * Signer for outbound traffic
         */
        signer_t *signer_out;
        
        /**
         * Multi purpose prf, set key, use it, forget it
         */
        prf_t *prf;
        
        /**
         * Prf function for derivating keymat child SAs
         */
        prf_t *child_prf;
        
        /**
         * Key to build outging authentication data (SKp)
         */
        chunk_t skp_build;

        /**
         * Key to verify incoming authentication data (SKp)
         */
        chunk_t skp_verify;
        
        /**
         * Virtual IP on local host, if any
         */
        host_t *my_virtual_ip;
        
        /**
         * Virtual IP on remote host, if any
         */
        host_t *other_virtual_ip;
        
        /**
         * List of DNS servers installed by us
         */
        linked_list_t *dns_servers;
        
        /**
         * list of peers additional addresses, transmitted via MOBIKE
         */
        linked_list_t *additional_addresses;
        
        /**
         * number pending UPDATE_SA_ADDRESS (MOBIKE)
         */
        u_int32_t pending_updates;

        /**
         * Timestamps for this IKE_SA
         */
        struct {
                /** last IKE message received */
                u_int32_t inbound;
                /** last IKE message sent */
                u_int32_t outbound;
                /** when IKE_SA became established */
                u_int32_t established;
                /** when IKE_SA gets rekeyed */
                u_int32_t rekey;
                /** when IKE_SA gets deleted */
                u_int32_t delete;
        } time;
        
        /**
         * how many times we have retried so far (keyingtries)
         */
        u_int32_t keyingtry;
};

/**
 * get the time of the latest traffic processed by the kernel
 */
static time_t get_use_time(private_ike_sa_t* this, bool inbound)
{
        iterator_t *iterator;
        child_sa_t *child_sa;
        time_t latest = 0, use_time;
        
        iterator = this->child_sas->create_iterator(this->child_sas, TRUE);
        while (iterator->iterate(iterator, (void**)&child_sa))
        {
                if (child_sa->get_use_time(child_sa, inbound, &use_time) == SUCCESS)
                {
                        latest = max(latest, use_time);
                }
        }
        iterator->destroy(iterator);
        
        if (inbound)
        {
                return max(this->time.inbound, latest);
        }
        else
        {
                return max(this->time.outbound, latest);
        }
}

/**
 * Implementation of ike_sa_t.get_unique_id
 */
static u_int32_t get_unique_id(private_ike_sa_t *this)
{
        return this->unique_id;
}

/**
 * Implementation of ike_sa_t.get_name.
 */
static char *get_name(private_ike_sa_t *this)
{
        if (this->peer_cfg)
        {
                return this->peer_cfg->get_name(this->peer_cfg);
        }
        return "(unnamed)";
}

        
/**
 * Implementation of ike_sa_t.get_stats.
 */
static void get_stats(private_ike_sa_t *this, u_int32_t *next_rekeying)
{
        if (next_rekeying)
        {
                *next_rekeying = this->time.rekey;
        }
}

/**
 * Implementation of ike_sa_t.get_my_host.
 */
static host_t *get_my_host(private_ike_sa_t *this)
{
        return this->my_host;
}

/**
 * Implementation of ike_sa_t.set_my_host.
 */
static void set_my_host(private_ike_sa_t *this, host_t *me)
{
        DESTROY_IF(this->my_host);
        this->my_host = me;
}

/**
 * Implementation of ike_sa_t.get_other_host.
 */
static host_t *get_other_host(private_ike_sa_t *this)
{
        return this->other_host;
}

/**
 * Implementation of ike_sa_t.set_other_host.
 */
static void set_other_host(private_ike_sa_t *this, host_t *other)
{
        DESTROY_IF(this->other_host);
        this->other_host = other;
}

/**
 * Implementation of ike_sa_t.get_peer_cfg
 */
static peer_cfg_t* get_peer_cfg(private_ike_sa_t *this)
{
        return this->peer_cfg;
}

/**
 * Implementation of ike_sa_t.set_peer_cfg
 */
static void set_peer_cfg(private_ike_sa_t *this, peer_cfg_t *peer_cfg)
{
        peer_cfg->get_ref(peer_cfg);
        this->peer_cfg = peer_cfg;

        if (this->ike_cfg == NULL)
        {
                this->ike_cfg = peer_cfg->get_ike_cfg(peer_cfg);
                this->ike_cfg->get_ref(this->ike_cfg);
        }
        
        /* apply values, so we are ready to initate/acquire */
        if (this->my_host->is_anyaddr(this->my_host))
        {
                host_t *me = this->ike_cfg->get_my_host(this->ike_cfg);
                set_my_host(this, me->clone(me));
        }
        if (this->other_host->is_anyaddr(this->other_host))
        {
                host_t *other = this->ike_cfg->get_other_host(this->ike_cfg);
                set_other_host(this, other->clone(other));
        }
        /* apply IDs if they are not already set */
        if (this->my_id->contains_wildcards(this->my_id))
        {
                DESTROY_IF(this->my_id);
                this->my_id = this->peer_cfg->get_my_id(this->peer_cfg);
                this->my_id = this->my_id->clone(this->my_id);
        }
        if (this->other_id->contains_wildcards(this->other_id))
        {
                DESTROY_IF(this->other_id);
                this->other_id = this->peer_cfg->get_other_id(this->peer_cfg);
                this->other_id = this->other_id->clone(this->other_id);
        }
}

/**
 * Implementation of ike_sa_t.send_keepalive
 */
static void send_keepalive(private_ike_sa_t *this)
{
        send_keepalive_job_t *job;
        time_t last_out, now, diff;
        
        if (!(this->conditions & COND_NAT_HERE))
        {       /* disable keep alives if we are not NATed anymore */
                return;
        }
        
        last_out = get_use_time(this, FALSE);
        now = time(NULL);
        
        diff = now - last_out;
        
        if (diff >= KEEPALIVE_INTERVAL)
        {
                packet_t *packet;
                chunk_t data;
                
                packet = packet_create();
                packet->set_source(packet, this->my_host->clone(this->my_host));
                packet->set_destination(packet, this->other_host->clone(this->other_host));
                data.ptr = malloc(1);
                data.ptr[0] = 0xFF;
                data.len = 1;
                packet->set_data(packet, data);
                DBG1(DBG_IKE, "sending keep alive");
                charon->sender->send(charon->sender, packet);
                diff = 0;
        }
        job = send_keepalive_job_create(this->ike_sa_id);
        charon->scheduler->schedule_job(charon->scheduler, (job_t*)job,
                                                                        (KEEPALIVE_INTERVAL - diff) * 1000);
}

/**
 * Implementation of ike_sa_t.get_ike_cfg
 */
static ike_cfg_t *get_ike_cfg(private_ike_sa_t *this)
{
        return this->ike_cfg;
}

/**
 * Implementation of ike_sa_t.set_ike_cfg
 */
static void set_ike_cfg(private_ike_sa_t *this, ike_cfg_t *ike_cfg)
{
        ike_cfg->get_ref(ike_cfg);
        this->ike_cfg = ike_cfg;
}
/**
 * Implementation of ike_sa_t.enable_extension.
 */
static void enable_extension(private_ike_sa_t *this, ike_extension_t extension)
{
        this->extensions |= extension;
}

/**
 * Implementation of ike_sa_t.has_extension.
 */
static bool supports_extension(private_ike_sa_t *this, ike_extension_t extension)
{
        return (this->extensions & extension) != FALSE;
}

/**
 * Implementation of ike_sa_t.has_condition.
 */
static bool has_condition(private_ike_sa_t *this, ike_condition_t condition)
{
        return (this->conditions & condition) != FALSE;
}

/**
 * Implementation of ike_sa_t.enable_condition.
 */
static void set_condition(private_ike_sa_t *this, ike_condition_t condition,
                                                  bool enable)
{
        if (has_condition(this, condition) != enable)
        {
                if (enable)
                {
                        this->conditions |= condition;
                        switch (condition)
                        {
                                case COND_STALE:
                                        DBG1(DBG_IKE, "no route to %H, setting IKE_SA to stale",
                                                 this->other_host);
                                        break;
                                case COND_NAT_HERE:
                                        DBG1(DBG_IKE, "local host is behind NAT, sending keep alives");
                                        this->conditions |= COND_NAT_ANY;
                                        send_keepalive(this);
                                        break;
                                case COND_NAT_THERE:
                                        DBG1(DBG_IKE, "remote host is behind NAT");
                                        this->conditions |= COND_NAT_ANY;
                                        break;
                                case COND_NAT_FAKE:
                                        DBG1(DBG_IKE, "faking NAT situation to enforce UDP encapsulation");
                                        this->conditions |= COND_NAT_ANY;
                                        break;
                                default:
                                        break;
                        }
                }
                else
                {
                        this->conditions &= ~condition;
                        switch (condition)
                        {
                                case COND_STALE:
                                        DBG1(DBG_IKE, "new route to %H found", this->other_host);
                                        break;
                                case COND_NAT_HERE:
                                case COND_NAT_FAKE:
                                case COND_NAT_THERE:
                                        set_condition(this, COND_NAT_ANY,
                                                                  has_condition(this, COND_NAT_HERE) ||
                                                                  has_condition(this, COND_NAT_THERE) ||
                                                                  has_condition(this, COND_NAT_FAKE));
                                        break;
                                default:
                                        break;
                        }
                }
        }
}

/**
 * Implementation of ike_sa_t.send_dpd
 */
static status_t send_dpd(private_ike_sa_t *this)
{
        send_dpd_job_t *job;
        time_t diff, delay;
        
        delay = this->peer_cfg->get_dpd_delay(this->peer_cfg);
        
        if (delay == 0)
        {
                /* DPD disabled */
                return SUCCESS;
        }
        
        if (this->task_manager->busy(this->task_manager))
        {
                /* an exchange is in the air, no need to start a DPD check */
                diff = 0;
        }
        else
        {
                /* check if there was any inbound traffic */
                time_t last_in, now;
                last_in = get_use_time(this, TRUE);
                now = time(NULL);
                diff = now - last_in;
                if (diff >= delay)
                {
                        /* to long ago, initiate dead peer detection */
                        task_t *task;
                        
                        task = (task_t*)ike_dpd_create(TRUE);
                        diff = 0;
                        DBG1(DBG_IKE, "sending DPD request");
                        
                        this->task_manager->queue_task(this->task_manager, task);
                        this->task_manager->initiate(this->task_manager);
                }
        }
        /* recheck in "interval" seconds */
        job = send_dpd_job_create(this->ike_sa_id);
        charon->scheduler->schedule_job(charon->scheduler, (job_t*)job,
                                                                        (delay - diff) * 1000);
        return SUCCESS;
}

/**
 * Implementation of ike_sa_t.get_state.
 */
static ike_sa_state_t get_state(private_ike_sa_t *this)
{
        return this->state;
}

/**
 * Implementation of ike_sa_t.set_state.
 */
static void set_state(private_ike_sa_t *this, ike_sa_state_t state)
{
        DBG1(DBG_IKE, "IKE_SA '%s' state change: %N => %N",
                 get_name(this),
                 ike_sa_state_names, this->state,
                 ike_sa_state_names, state);
        
        switch (state)
        {
                case IKE_ESTABLISHED:
                {
                        if (this->state == IKE_CONNECTING)
                        {
                                job_t *job;
                                u_int32_t now = time(NULL);
                                u_int32_t soft, hard;
                                bool reauth;
                        
                                this->time.established = now;
                                /* start DPD checks */
                                send_dpd(this);
                                
                                /* schedule rekeying/reauthentication */
                                soft = this->peer_cfg->get_lifetime(this->peer_cfg, TRUE);
                                hard = this->peer_cfg->get_lifetime(this->peer_cfg, FALSE);
                                reauth = this->peer_cfg->use_reauth(this->peer_cfg);
                                DBG1(DBG_IKE, "scheduling %s in %ds, maximum lifetime %ds",
                                         reauth ? "reauthentication": "rekeying", soft, hard);
                                         
                                if (soft)
                                {
                                        this->time.rekey = now + soft;
                                        job = (job_t*)rekey_ike_sa_job_create(this->ike_sa_id, reauth);
                                        charon->scheduler->schedule_job(charon->scheduler, job,
                                                                                                        soft * 1000);
                                }
                                
                                if (hard)
                                {
                                        this->time.delete = now + hard;
                                        job = (job_t*)delete_ike_sa_job_create(this->ike_sa_id, TRUE);
                                        charon->scheduler->schedule_job(charon->scheduler, job,
                                                                                                        hard * 1000);
                                }
                        }
                        break;
                }
                case IKE_DELETING:
                {
                        /* delete may fail if a packet gets lost, so set a timeout */
                        job_t *job = (job_t*)delete_ike_sa_job_create(this->ike_sa_id, TRUE);
                        charon->scheduler->schedule_job(charon->scheduler, job, 
                                                                                        HALF_OPEN_IKE_SA_TIMEOUT);
                        break;
                }
                default:
                        break;
        }
        
        this->state = state;
}

/**
 * Implementation of ike_sa_t.reset
 */
static void reset(private_ike_sa_t *this)
{
        /*  the responder ID is reset, as peer may choose another one */
        if (this->ike_sa_id->is_initiator(this->ike_sa_id))
        {
                this->ike_sa_id->set_responder_spi(this->ike_sa_id, 0);
        }
        
        set_state(this, IKE_CREATED);
        
        this->task_manager->reset(this->task_manager);
}

/**
 * Implementation of ike_sa_t.set_virtual_ip
 */
static void set_virtual_ip(private_ike_sa_t *this, bool local, host_t *ip)
{
        if (local)
        {
                DBG1(DBG_IKE, "installing new virtual IP %H", ip);
                if (charon->kernel_interface->add_ip(charon->kernel_interface, ip,
                                                                                         this->my_host) == SUCCESS)
                {
                        if (this->my_virtual_ip)
                        {
                                DBG1(DBG_IKE, "removing old virtual IP %H", this->my_virtual_ip);
                                charon->kernel_interface->del_ip(charon->kernel_interface,
                                                                                                 this->my_virtual_ip);
                        }
                        DESTROY_IF(this->my_virtual_ip);
                        this->my_virtual_ip = ip->clone(ip);
                }
                else
                {
                        DBG1(DBG_IKE, "installing virtual IP %H failed", ip);
                        this->my_virtual_ip = NULL;
                }
        }
        else
        {
                DESTROY_IF(this->other_virtual_ip);
                this->other_virtual_ip = ip->clone(ip);
        }
}

/**
 * Implementation of ike_sa_t.get_virtual_ip
 */
static host_t* get_virtual_ip(private_ike_sa_t *this, bool local)
{
        if (local)
        {
                return this->my_virtual_ip;
        }
        else
        {
                return this->other_virtual_ip;
        }
}

/**
 * Implementation of ike_sa_t.add_additional_address.
 */
static void add_additional_address(private_ike_sa_t *this, host_t *host)
{
        this->additional_addresses->insert_last(this->additional_addresses, host);
}
        
/**
 * Implementation of ike_sa_t.create_additional_address_iterator.
 */
static iterator_t* create_additional_address_iterator(private_ike_sa_t *this)
{
        return this->additional_addresses->create_iterator(
                                                                                        this->additional_addresses, TRUE);
}
        
/**
 * Implementation of ike_sa_t.set_pending_updates.
 */
static void set_pending_updates(private_ike_sa_t *this, u_int32_t updates)
{
        this->pending_updates = updates;
}

/**
 * Implementation of ike_sa_t.get_pending_updates.
 */
static u_int32_t get_pending_updates(private_ike_sa_t *this)
{
        return this->pending_updates;
}

/**
 * Update hosts, as addresses may change (NAT)
 */
static void update_hosts(private_ike_sa_t *this, host_t *me, host_t *other)
{
        bool update = FALSE;
        
        if (supports_extension(this, EXT_MOBIKE))
        {       /* if peer speaks mobike, address updates are explicit only */
                return;
        }
        
        if (me == NULL)
        {
                me = this->my_host;
        }
        if (other == NULL)
        {
                other = this->other_host;
        }
        
        /* apply hosts on first received message */
        if (this->my_host->is_anyaddr(this->my_host) ||
                this->other_host->is_anyaddr(this->other_host))
        {
                set_my_host(this, me->clone(me));
                set_other_host(this, other->clone(other));
                update = TRUE;
        }
        else
        {
                /* update our address in any case */
                if (!me->equals(me, this->my_host))
                {
                        set_my_host(this, me->clone(me));
                        update = TRUE;
                }
                
                if (!other->equals(other, this->other_host))
                {
                        /* update others adress if we are NOT NATed,
                         * and allow port changes if we are NATed */
                        if (!has_condition(this, COND_NAT_HERE) ||
                                other->ip_equals(other, this->other_host))
                        {
                                set_other_host(this, other->clone(other));
                                update = TRUE;
                        }
                }
        }
        
        /* update all associated CHILD_SAs, if required */
        if (update)
        {
                iterator_t *iterator;
                child_sa_t *child_sa;
        
                iterator = this->child_sas->create_iterator(this->child_sas, TRUE);
                while (iterator->iterate(iterator, (void**)&child_sa))
                {
                        child_sa->update_hosts(child_sa, this->my_host, this->other_host,
                                                                   has_condition(this, COND_NAT_ANY));
                }
                iterator->destroy(iterator);
        }
}

/**
 * Implementation of ike_sa_t.generate
 */
static status_t generate_message(private_ike_sa_t *this, message_t *message,
                                                                 packet_t **packet)
{
        this->time.outbound = time(NULL);
        message->set_ike_sa_id(message, this->ike_sa_id);
        return message->generate(message, this->crypter_out, this->signer_out, packet);
}

/**
 * send a notify back to the sender
 */
static void send_notify_response(private_ike_sa_t *this, message_t *request,
                                                                 notify_type_t type)
{
        message_t *response;
        packet_t *packet;
        
        response = message_create();
        response->set_exchange_type(response, request->get_exchange_type(request));
        response->set_request(response, FALSE);
        response->set_message_id(response, request->get_message_id(request));
        response->add_notify(response, FALSE, type, chunk_empty);
        if (this->my_host->is_anyaddr(this->my_host))
        {
                this->my_host->destroy(this->my_host);
                this->my_host = request->get_destination(request);
                this->my_host = this->my_host->clone(this->my_host);
        }
        if (this->other_host->is_anyaddr(this->other_host))
        {
                this->other_host->destroy(this->other_host);
                this->other_host = request->get_source(request);
                this->other_host = this->other_host->clone(this->other_host);
        }
        if (generate_message(this, response, &packet) == SUCCESS)
        {
                charon->sender->send(charon->sender, packet);
        }
        response->destroy(response);
}

#ifdef P2P
/**
 * Implementation of ike_sa_t.get_server_reflexive_host.
 */
static host_t *get_server_reflexive_host(private_ike_sa_t *this)
{
        return this->server_reflexive_host;
}

/**
 * Implementation of ike_sa_t.set_server_reflexive_host.
 */
static void set_server_reflexive_host(private_ike_sa_t *this, host_t *host)
{
        DESTROY_IF(this->server_reflexive_host);
        this->server_reflexive_host = host;
}

/**
 * Implementation of ike_sa_t.respond
 */
static status_t respond(private_ike_sa_t *this, identification_t *peer_id,
                chunk_t session_id)
{
        ike_p2p_t *task = ike_p2p_create(&this->public, TRUE);
        task->respond(task, peer_id, session_id);
        this->task_manager->queue_task(this->task_manager, (task_t*)task);
        return this->task_manager->initiate(this->task_manager);
}

/**
 * Implementation of ike_sa_t.callback
 */
static status_t callback(private_ike_sa_t *this, identification_t *peer_id)
{
        ike_p2p_t *task = ike_p2p_create(&this->public, TRUE);
        task->callback(task, peer_id);
        this->task_manager->queue_task(this->task_manager, (task_t*)task);
        return this->task_manager->initiate(this->task_manager);
}

/**
 * Implementation of ike_sa_t.relay
 */
static status_t relay(private_ike_sa_t *this, identification_t *requester,
                        chunk_t session_id, chunk_t session_key, linked_list_t *endpoints, bool response)
{
        ike_p2p_t *task = ike_p2p_create(&this->public, TRUE);
        task->relay(task, requester, session_id, session_key, endpoints, response);
        this->task_manager->queue_task(this->task_manager, (task_t*)task);
        return this->task_manager->initiate(this->task_manager);
}

/**
 * Implementation of ike_sa_t.initiate_mediation
 */
static status_t initiate_mediation(private_ike_sa_t *this, peer_cfg_t *mediated_cfg)
{
        ike_p2p_t *task = ike_p2p_create(&this->public, TRUE);
        task->connect(task, mediated_cfg->get_peer_id(mediated_cfg));
        this->task_manager->queue_task(this->task_manager, (task_t*)task);
        return this->task_manager->initiate(this->task_manager);
}

/**
 * Implementation of ike_sa_t.initiate_mediated
 */
static status_t initiate_mediated(private_ike_sa_t *this, host_t *me, host_t *other,
                linked_list_t *childs)
{
        this->my_host = me->clone(me);
        this->other_host = other->clone(other);
        
        task_t *task;
        child_cfg_t *child_cfg; 
        iterator_t *iterator = childs->create_iterator(childs, TRUE);
        while (iterator->iterate(iterator, (void**)&child_cfg))
        {
                task = (task_t*)child_create_create(&this->public, child_cfg);
                this->task_manager->queue_task(this->task_manager, task);
        }
        iterator->destroy(iterator);
        return this->task_manager->initiate(this->task_manager);
}
#endif /* P2P */

/**
 * Implementation of ike_sa_t.initiate.
 */
static status_t initiate(private_ike_sa_t *this, child_cfg_t *child_cfg)
{
        task_t *task;
        
        if (this->state == IKE_CREATED)
        {
                if (this->other_host->is_anyaddr(this->other_host)
#ifdef P2P
                        && !this->peer_cfg->get_mediated_by(this->peer_cfg)
#endif /* P2P */
                        )
                {
                        child_cfg->destroy(child_cfg);
                        SIG(IKE_UP_START, "initiating IKE_SA");
                        SIG(IKE_UP_FAILED, "unable to initiate to %%any");
                        return DESTROY_ME;
                }
                
                task = (task_t*)ike_init_create(&this->public, TRUE, NULL);
                this->task_manager->queue_task(this->task_manager, task);
                task = (task_t*)ike_natd_create(&this->public, TRUE);
                this->task_manager->queue_task(this->task_manager, task);
                task = (task_t*)ike_cert_create(&this->public, TRUE);
                this->task_manager->queue_task(this->task_manager, task);
                task = (task_t*)ike_auth_create(&this->public, TRUE);
                this->task_manager->queue_task(this->task_manager, task);
                task = (task_t*)ike_config_create(&this->public, TRUE);
                this->task_manager->queue_task(this->task_manager, task);
                if (this->peer_cfg->use_mobike(this->peer_cfg))
                {
                        task = (task_t*)ike_mobike_create(&this->public, TRUE);
                        this->task_manager->queue_task(this->task_manager, task);
                }
#ifdef P2P
                task = (task_t*)ike_p2p_create(&this->public, TRUE);
                this->task_manager->queue_task(this->task_manager, task);
#endif /* P2P */
        }

#ifdef P2P
        if (this->peer_cfg->get_mediated_by(this->peer_cfg))
        {
                // mediated connection, initiate mediation process
                job_t *job = (job_t*)initiate_mediation_job_create(this->ike_sa_id, child_cfg);
                child_cfg->destroy(child_cfg);
                charon->processor->queue_job(charon->processor, job);
                return SUCCESS;
        }
        else if (this->peer_cfg->is_mediation(this->peer_cfg))
        {
                if (this->state == IKE_ESTABLISHED)
                {// FIXME: we should try to find a better solution to this
                        SIG(CHILD_UP_SUCCESS, "mediation connection is already up and running");
                }
        }
        else
#endif /* P2P */
        {
                // normal IKE_SA with CHILD_SA
                task = (task_t*)child_create_create(&this->public, child_cfg);
                child_cfg->destroy(child_cfg);
                this->task_manager->queue_task(this->task_manager, task);
        }
        
        return this->task_manager->initiate(this->task_manager);
}

/**
 * Implementation of ike_sa_t.acquire.
 */
static status_t acquire(private_ike_sa_t *this, u_int32_t reqid)
{// FIXME: P2P-NAT-T
        child_cfg_t *child_cfg;
        iterator_t *iterator;
        child_sa_t *current, *child_sa = NULL;
        task_t *task;
        child_create_t *child_create;
        
        if (this->state == IKE_DELETING)
        {
                SIG(CHILD_UP_START, "acquiring CHILD_SA on kernel request");
                SIG(CHILD_UP_FAILED, "acquiring CHILD_SA (reqid %d) failed: "
                        "IKE_SA is deleting", reqid);
                return FAILED;
        }
        
        /* find CHILD_SA */
        iterator = this->child_sas->create_iterator(this->child_sas, TRUE);
        while (iterator->iterate(iterator, (void**)&current))
        {
                if (current->get_reqid(current) == reqid)
                {
                        child_sa = current;
                        break;
                }
        }
        iterator->destroy(iterator);
        if (!child_sa)
        {
                SIG(CHILD_UP_START, "acquiring CHILD_SA on kernel request");
                SIG(CHILD_UP_FAILED, "acquiring CHILD_SA (reqid %d) failed: "
                        "CHILD_SA not found", reqid);
                return FAILED;
        }
        
        
        if (this->state == IKE_CREATED)
        {
                task = (task_t*)ike_init_create(&this->public, TRUE, NULL);
                this->task_manager->queue_task(this->task_manager, task);
                task = (task_t*)ike_natd_create(&this->public, TRUE);
                this->task_manager->queue_task(this->task_manager, task);
                task = (task_t*)ike_cert_create(&this->public, TRUE);
                this->task_manager->queue_task(this->task_manager, task);
                task = (task_t*)ike_auth_create(&this->public, TRUE);
                this->task_manager->queue_task(this->task_manager, task);
                task = (task_t*)ike_config_create(&this->public, TRUE);
                this->task_manager->queue_task(this->task_manager, task);
                if (this->peer_cfg->use_mobike(this->peer_cfg))
                {
                        task = (task_t*)ike_mobike_create(&this->public, TRUE);
                        this->task_manager->queue_task(this->task_manager, task);
                }
        }
        
        child_cfg = child_sa->get_config(child_sa);
        child_create = child_create_create(&this->public, child_cfg);
        child_create->use_reqid(child_create, reqid);
        this->task_manager->queue_task(this->task_manager, (task_t*)child_create);
        
        return this->task_manager->initiate(this->task_manager);
}

/**
 * Implementation of ike_sa_t.route.
 */
static status_t route(private_ike_sa_t *this, child_cfg_t *child_cfg)
{
        child_sa_t *child_sa;
        iterator_t *iterator;
        linked_list_t *my_ts, *other_ts;
        host_t *me, *other;
        status_t status;
        
        SIG(CHILD_ROUTE_START, "routing CHILD_SA");
        
        /* check if not already routed*/
        iterator = this->child_sas->create_iterator(this->child_sas, TRUE);
        while (iterator->iterate(iterator, (void**)&child_sa))
        {
                if (child_sa->get_state(child_sa) == CHILD_ROUTED &&
                        streq(child_sa->get_name(child_sa), child_cfg->get_name(child_cfg)))
                {
                        iterator->destroy(iterator);
                        SIG(CHILD_ROUTE_FAILED, "CHILD_SA with such a config already routed");
                        return FAILED;
                }
        }
        iterator->destroy(iterator);
        
        switch (this->state)
        {
                case IKE_DELETING:
                case IKE_REKEYING:
                        SIG(CHILD_ROUTE_FAILED,
                                "unable to route CHILD_SA, as its IKE_SA gets deleted");
                        return FAILED;
                case IKE_CREATED:
                case IKE_CONNECTING:
                case IKE_ESTABLISHED:
                default:
                        break;
        }

        /* install kernel policies */
        child_sa = child_sa_create(this->my_host, this->other_host, this->my_id,
                                                           this->other_id, child_cfg, FALSE, 0);
        me = this->my_host;
        if (this->my_virtual_ip)
        {
                me = this->my_virtual_ip;
        }
        other = this->other_host;
        if (this->other_virtual_ip)
        {
                other = this->other_virtual_ip;
        }
        
        my_ts = child_cfg->get_traffic_selectors(child_cfg, TRUE, NULL, me);
        other_ts = child_cfg->get_traffic_selectors(child_cfg, FALSE, NULL, other);
        status = child_sa->add_policies(child_sa, my_ts, other_ts,
                                                                        child_cfg->get_mode(child_cfg));
        my_ts->destroy_offset(my_ts, offsetof(traffic_selector_t, destroy));
        other_ts->destroy_offset(other_ts, offsetof(traffic_selector_t, destroy));
        if (status == SUCCESS)
        {
                this->child_sas->insert_last(this->child_sas, child_sa);
                SIG(CHILD_ROUTE_SUCCESS, "CHILD_SA routed");
        }
        else
        {
                SIG(CHILD_ROUTE_FAILED, "routing CHILD_SA failed");
        }
        return status;
}

/**
 * Implementation of ike_sa_t.unroute.
 */
static status_t unroute(private_ike_sa_t *this, u_int32_t reqid)
{
        iterator_t *iterator;
        child_sa_t *child_sa;
        bool found = FALSE;
        
        SIG(CHILD_UNROUTE_START, "unrouting CHILD_SA");
        
        /* find CHILD_SA in ROUTED state */
        iterator = this->child_sas->create_iterator(this->child_sas, TRUE);
        while (iterator->iterate(iterator, (void**)&child_sa))
        {
                if (child_sa->get_state(child_sa) == CHILD_ROUTED &&
                        child_sa->get_reqid(child_sa) == reqid)
                {
                        iterator->remove(iterator);
                        SIG(CHILD_UNROUTE_SUCCESS, "CHILD_SA unrouted");
                        child_sa->destroy(child_sa);
                        found = TRUE;
                        break;
                }
        }
        iterator->destroy(iterator);
        
        if (!found)
        {
                SIG(CHILD_UNROUTE_FAILED, "CHILD_SA to unroute not found");
                return FAILED;
        }
        /* if we are not established, and we have no more routed childs, remove whole SA */
        if (this->state == IKE_CREATED &&
                this->child_sas->get_count(this->child_sas) == 0)
        {
                return DESTROY_ME;
        }
        return SUCCESS;
}
/**
 * Implementation of ike_sa_t.process_message.
 */
static status_t process_message(private_ike_sa_t *this, message_t *message)
{
        status_t status;
        bool is_request;
        
        is_request = message->get_request(message);
        
        status = message->parse_body(message, this->crypter_in, this->signer_in);
        if (status != SUCCESS)
        {
                
                if (is_request)
                {
                        switch (status)
                        {
                                case NOT_SUPPORTED:
                                        DBG1(DBG_IKE, "ciritcal unknown payloads found");
                                        if (is_request)
                                        {
                                                send_notify_response(this, message, UNSUPPORTED_CRITICAL_PAYLOAD);
                                        }
                                        break;
                                case PARSE_ERROR:
                                        DBG1(DBG_IKE, "message parsing failed");
                                        if (is_request)
                                        {
                                                send_notify_response(this, message, INVALID_SYNTAX);
                                        }
                                        break;
                                case VERIFY_ERROR:
                                        DBG1(DBG_IKE, "message verification failed");
                                        if (is_request)
                                        {
                                                send_notify_response(this, message, INVALID_SYNTAX);
                                        }
                                        break;
                                case FAILED:
                                        DBG1(DBG_IKE, "integrity check failed");
                                        /* ignored */
                                        break;
                                case INVALID_STATE:
                                        DBG1(DBG_IKE, "found encrypted message, but no keys available");
                                        if (is_request)
                                        {
                                                send_notify_response(this, message, INVALID_SYNTAX);
                                        }
                                default:
                                        break;
                        }
                }
                DBG1(DBG_IKE, "%N %s with message ID %d processing failed",
                         exchange_type_names, message->get_exchange_type(message),
                         message->get_request(message) ? "request" : "response",
                         message->get_message_id(message));
                return status;
        }
        else
        {
                host_t *me, *other;
                private_ike_sa_t *new;
                iterator_t *iterator;
                child_sa_t *child;
                bool has_routed = FALSE;
                
                me = message->get_destination(message);
                other = message->get_source(message);
        
                /* if this IKE_SA is virgin, we check for a config */
                if (this->ike_cfg == NULL)
                {
                        job_t *job;
                        this->ike_cfg = charon->backends->get_ike_cfg(charon->backends,
                                                                                                                  me, other);
                        if (this->ike_cfg == NULL)
                        {
                                /* no config found for these hosts, destroy */
                                DBG1(DBG_IKE, "no IKE config found for %H...%H, sending %N",
                                         me, other, notify_type_names, NO_PROPOSAL_CHOSEN);
                                send_notify_response(this, message, NO_PROPOSAL_CHOSEN);
                                return DESTROY_ME;
                        }
                        /* add a timeout if peer does not establish it completely */
                        job = (job_t*)delete_ike_sa_job_create(this->ike_sa_id, FALSE);
                        charon->scheduler->schedule_job(charon->scheduler, job,
                                                                                        HALF_OPEN_IKE_SA_TIMEOUT);
                }
                
                /* check if message is trustworthy, and update host information */
                if (this->state == IKE_CREATED || this->state == IKE_CONNECTING ||
                        message->get_exchange_type(message) != IKE_SA_INIT)
                {
                        update_hosts(this, me, other);
                        this->time.inbound = time(NULL);
                }
                status = this->task_manager->process_message(this->task_manager, message);
                if (status != DESTROY_ME)
                {
                        return status;
                }
                /* if IKE_SA gets closed for any reasons, reroute routed children */
                iterator = this->child_sas->create_iterator(this->child_sas, TRUE);
                while (iterator->iterate(iterator, (void**)&child))
                {
                        if (child->get_state(child) == CHILD_ROUTED)
                        {
                                has_routed = TRUE;
                                break;
                        }
                }
                iterator->destroy(iterator);
                if (!has_routed)
                {
                        return status;
                }
                /* move routed children to a new IKE_SA, apply connection info */
                new = (private_ike_sa_t*)charon->ike_sa_manager->checkout_new(
                                                                                        charon->ike_sa_manager, TRUE);
                set_peer_cfg(new, this->peer_cfg);
                new->other_host->destroy(new->other_host);
                new->other_host = this->other_host->clone(this->other_host);
                if (!has_condition(this, COND_NAT_THERE))
                {
                        new->other_host->set_port(new->other_host, IKEV2_UDP_PORT);
                }
                if (this->my_virtual_ip)
                {
                        set_virtual_ip(new, TRUE, this->my_virtual_ip);
                }
                iterator = this->child_sas->create_iterator(this->child_sas, TRUE);
                while (iterator->iterate(iterator, (void**)&child))
                {
                        if (child->get_state(child) == CHILD_ROUTED)
                        {
                                route(new, child->get_config(child));
                        }
                }
                iterator->destroy(iterator);
                charon->ike_sa_manager->checkin(charon->ike_sa_manager, &new->public);
                return status;
        }
}

/**
 * Implementation of ike_sa_t.retransmit.
 */
static status_t retransmit(private_ike_sa_t *this, u_int32_t message_id)
{// FIXME: P2P-NAT-T
        this->time.outbound = time(NULL);
        if (this->task_manager->retransmit(this->task_manager, message_id) != SUCCESS)
        {
                child_cfg_t *child_cfg;
                child_sa_t* child_sa;
                linked_list_t *to_route, *to_restart;
                iterator_t *iterator;
                
                /* send a proper signal to brief interested bus listeners */
                switch (this->state)
                {
                        case IKE_CONNECTING:
                        {
                                /* retry IKE_SA_INIT if we have multiple keyingtries */
                                u_int32_t tries = this->peer_cfg->get_keyingtries(this->peer_cfg);
                                this->keyingtry++;
                                if (tries == 0 || tries > this->keyingtry)
                                {
                                        SIG(IKE_UP_FAILED, "peer not responding, trying again "
                                                "(%d/%d) in background ", this->keyingtry + 1, tries);
                                        reset(this);
                                        return this->task_manager->initiate(this->task_manager);
                                }
                                SIG(IKE_UP_FAILED, "establishing IKE_SA failed, peer not responding");
                                break;
                        }
                        case IKE_REKEYING:
                                SIG(IKE_REKEY_FAILED, "rekeying IKE_SA failed, peer not responding");
                                break;
                        case IKE_DELETING:
                                SIG(IKE_DOWN_FAILED, "proper IKE_SA delete failed, peer not responding");
                                break;
                        default:
                                break;
                }
                
                /* summarize how we have to handle each child */
                to_route = linked_list_create();
                to_restart = linked_list_create();
                iterator = this->child_sas->create_iterator(this->child_sas, TRUE);
                while (iterator->iterate(iterator, (void**)&child_sa))
                {
                        child_cfg = child_sa->get_config(child_sa);
                        
                        if (child_sa->get_state(child_sa) == CHILD_ROUTED)
                        {
                                /* reroute routed CHILD_SAs */
                                to_route->insert_last(to_route, child_cfg);
                        }
                        else
                        {
                                /* use DPD action for established CHILD_SAs */
                                switch (this->peer_cfg->get_dpd_action(this->peer_cfg))
                                {
                                        case DPD_ROUTE:
                                                to_route->insert_last(to_route, child_cfg);
                                                break;
                                        case DPD_RESTART:
                                                to_restart->insert_last(to_restart, child_cfg);
                                                break;
                                        default:
                                                break;
                                }
                        }
                }
                iterator->destroy(iterator);
                
                /* create a new IKE_SA if we have to route or to restart */
                if (to_route->get_count(to_route) || to_restart->get_count(to_restart))
                {
                        private_ike_sa_t *new;
                        task_t *task;
                        
                        new = (private_ike_sa_t*)charon->ike_sa_manager->checkout_new(
                                                                                                charon->ike_sa_manager, TRUE);
                        
                        set_peer_cfg(new, this->peer_cfg);
                        /* use actual used host, not the wildcarded one in config */
                        new->other_host->destroy(new->other_host);
                        new->other_host = this->other_host->clone(this->other_host);
                        /* reset port to 500, but only if peer is not NATed */
                        if (!has_condition(this, COND_NAT_THERE))
                        {
                                new->other_host->set_port(new->other_host, IKEV2_UDP_PORT);
                        }
                        /* take over virtual ip, as we need it for a proper route */
                        if (this->my_virtual_ip)
                        {
                                set_virtual_ip(new, TRUE, this->my_virtual_ip);
                        }
                        
                        /* install routes */
                        while (to_route->remove_last(to_route, (void**)&child_cfg) == SUCCESS)
                        {
                                route(new, child_cfg);
                        }
                        
                        /* restart children */
                        if (to_restart->get_count(to_restart))
                        {
                                task = (task_t*)ike_init_create(&new->public, TRUE, NULL);
                                new->task_manager->queue_task(new->task_manager, task);
                                task = (task_t*)ike_natd_create(&new->public, TRUE);
                                new->task_manager->queue_task(new->task_manager, task);
                                task = (task_t*)ike_cert_create(&new->public, TRUE);
                                new->task_manager->queue_task(new->task_manager, task);
                                task = (task_t*)ike_config_create(&new->public, TRUE);
                                new->task_manager->queue_task(new->task_manager, task);
                                task = (task_t*)ike_auth_create(&new->public, TRUE);
                                new->task_manager->queue_task(new->task_manager, task);
                                
                                while (to_restart->remove_last(to_restart, (void**)&child_cfg) == SUCCESS)
                                {
                                        task = (task_t*)child_create_create(&new->public, child_cfg);
                                        new->task_manager->queue_task(new->task_manager, task);
                                }               
                                if (this->peer_cfg->use_mobike(this->peer_cfg))
                                {
                                        task = (task_t*)ike_mobike_create(&new->public, TRUE);
                                        new->task_manager->queue_task(new->task_manager, task);
                                }
                                new->task_manager->initiate(new->task_manager);
                        }
                        charon->ike_sa_manager->checkin(charon->ike_sa_manager, &new->public);
                }
                to_route->destroy(to_route);
                to_restart->destroy(to_restart);
                return DESTROY_ME;
        }
        return SUCCESS;
}

/**
 * Implementation of ike_sa_t.get_prf.
 */
static prf_t *get_prf(private_ike_sa_t *this)
{
        return this->prf;
}

/**
 * Implementation of ike_sa_t.get_prf.
 */
static prf_t *get_child_prf(private_ike_sa_t *this)
{
        return this->child_prf;
}

/**
 * Implementation of ike_sa_t.get_skp_bild
 */
static chunk_t get_skp_build(private_ike_sa_t *this)
{
        return this->skp_build;
}

/**
 * Implementation of ike_sa_t.get_skp_verify
 */
static chunk_t get_skp_verify(private_ike_sa_t *this)
{
        return this->skp_verify;
}

/**
 * Implementation of ike_sa_t.get_id.
 */
static ike_sa_id_t* get_id(private_ike_sa_t *this)
{
        return this->ike_sa_id;
}

/**
 * Implementation of ike_sa_t.get_my_id.
 */
static identification_t* get_my_id(private_ike_sa_t *this)
{
        return this->my_id;
}

/**
 * Implementation of ike_sa_t.set_my_id.
 */
static void set_my_id(private_ike_sa_t *this, identification_t *me)
{
        DESTROY_IF(this->my_id);
        this->my_id = me;
}

/**
 * Implementation of ike_sa_t.get_other_id.
 */
static identification_t* get_other_id(private_ike_sa_t *this)
{
        return this->other_id;
}

/**
 * Implementation of ike_sa_t.set_other_id.
 */
static void set_other_id(private_ike_sa_t *this, identification_t *other)
{
        DESTROY_IF(this->other_id);
        this->other_id = other;
}

/**
 * Implementation of ike_sa_t.get_other_ca.
 */
static ca_info_t* get_other_ca(private_ike_sa_t *this)
{
        return this->other_ca;
}

/**
 * Implementation of ike_sa_t.set_other_ca.
 */
static void set_other_ca(private_ike_sa_t *this, ca_info_t *other_ca)
{
        this->other_ca = other_ca;
}

/**
 * Implementation of ike_sa_t.derive_keys.
 */
static status_t derive_keys(private_ike_sa_t *this,
                                                        proposal_t *proposal, chunk_t secret,
                                                        chunk_t nonce_i, chunk_t nonce_r,
                                                        bool initiator, prf_t *child_prf, prf_t *old_prf)
{
        prf_plus_t *prf_plus;
        chunk_t skeyseed, key, nonces, prf_plus_seed;
        algorithm_t *algo;
        size_t key_size;
        crypter_t *crypter_i, *crypter_r;
        signer_t *signer_i, *signer_r;
        u_int8_t spi_i_buf[sizeof(u_int64_t)], spi_r_buf[sizeof(u_int64_t)];
        chunk_t spi_i = chunk_from_buf(spi_i_buf);
        chunk_t spi_r = chunk_from_buf(spi_r_buf);
        
        /* Create SAs general purpose PRF first, we may use it here */
        if (!proposal->get_algorithm(proposal, PSEUDO_RANDOM_FUNCTION, &algo))
        {
                DBG1(DBG_IKE, "key derivation failed: no PSEUDO_RANDOM_FUNCTION");;
                return FAILED;
        }
        this->prf = prf_create(algo->algorithm);
        if (this->prf == NULL)
        {
                DBG1(DBG_IKE, "key derivation failed: PSEUDO_RANDOM_FUNCTION "
                         "%N not supported!", pseudo_random_function_names, algo->algorithm);
                return FAILED;
        }
        
        DBG4(DBG_IKE, "shared Diffie Hellman secret %B", &secret);
        nonces = chunk_cat("cc", nonce_i, nonce_r);
        *((u_int64_t*)spi_i.ptr) = this->ike_sa_id->get_initiator_spi(this->ike_sa_id);
        *((u_int64_t*)spi_r.ptr) = this->ike_sa_id->get_responder_spi(this->ike_sa_id);
        prf_plus_seed = chunk_cat("ccc", nonces, spi_i, spi_r);
        
        /* KEYMAT = prf+ (SKEYSEED, Ni | Nr | SPIi | SPIr) 
         *
         * if we are rekeying, SKEYSEED is built on another way
         */
        if (child_prf == NULL) /* not rekeying */
        {
                /* SKEYSEED = prf(Ni | Nr, g^ir) */
                this->prf->set_key(this->prf, nonces);
                this->prf->allocate_bytes(this->prf, secret, &skeyseed);
                DBG4(DBG_IKE, "SKEYSEED %B", &skeyseed);
                this->prf->set_key(this->prf, skeyseed);
                chunk_free(&skeyseed);
                chunk_free(&secret);
                prf_plus = prf_plus_create(this->prf, prf_plus_seed);
        }
        else
        {
                /* SKEYSEED = prf(SK_d (old), [g^ir (new)] | Ni | Nr) 
                 * use OLD SAs PRF functions for both prf_plus and prf */
                secret = chunk_cat("mc", secret, nonces);
                child_prf->allocate_bytes(child_prf, secret, &skeyseed);
                DBG4(DBG_IKE, "SKEYSEED %B", &skeyseed);
                old_prf->set_key(old_prf, skeyseed);
                chunk_free(&skeyseed);
                chunk_free(&secret);
                prf_plus = prf_plus_create(old_prf, prf_plus_seed);
        }
        chunk_free(&nonces);
        chunk_free(&prf_plus_seed);
        
        /* KEYMAT = SK_d | SK_ai | SK_ar | SK_ei | SK_er | SK_pi | SK_pr */
        
        /* SK_d is used for generating CHILD_SA key mat => child_prf */
        proposal->get_algorithm(proposal, PSEUDO_RANDOM_FUNCTION, &algo);
        this->child_prf = prf_create(algo->algorithm);
        key_size = this->child_prf->get_key_size(this->child_prf);
        prf_plus->allocate_bytes(prf_plus, key_size, &key);
        DBG4(DBG_IKE, "Sk_d secret %B", &key);
        this->child_prf->set_key(this->child_prf, key);
        chunk_free(&key);
        
        /* SK_ai/SK_ar used for integrity protection => signer_in/signer_out */
        if (!proposal->get_algorithm(proposal, INTEGRITY_ALGORITHM, &algo))
        {
                DBG1(DBG_IKE, "key derivation failed: no INTEGRITY_ALGORITHM");
                return FAILED;
        }
        signer_i = signer_create(algo->algorithm);
        signer_r = signer_create(algo->algorithm);
        if (signer_i == NULL || signer_r == NULL)
        {
                DBG1(DBG_IKE, "key derivation failed: INTEGRITY_ALGORITHM "
                        "%N not supported!", integrity_algorithm_names ,algo->algorithm);
                return FAILED;
        }
        key_size = signer_i->get_key_size(signer_i);
        
        prf_plus->allocate_bytes(prf_plus, key_size, &key);
        DBG4(DBG_IKE, "Sk_ai secret %B", &key);
        signer_i->set_key(signer_i, key);
        chunk_free(&key);
        
        prf_plus->allocate_bytes(prf_plus, key_size, &key);
        DBG4(DBG_IKE, "Sk_ar secret %B", &key);
        signer_r->set_key(signer_r, key);
        chunk_free(&key);
        
        if (initiator)
        {
                this->signer_in = signer_r;
                this->signer_out = signer_i;
        }
        else
        {
                this->signer_in = signer_i;
                this->signer_out = signer_r;
        }
        
        /* SK_ei/SK_er used for encryption => crypter_in/crypter_out */
        if (!proposal->get_algorithm(proposal, ENCRYPTION_ALGORITHM, &algo))
        {
                DBG1(DBG_IKE, "key derivation failed: no ENCRYPTION_ALGORITHM");
                return FAILED;
        }
        crypter_i = crypter_create(algo->algorithm, algo->key_size / 8);
        crypter_r = crypter_create(algo->algorithm, algo->key_size / 8);
        if (crypter_i == NULL || crypter_r == NULL)
        {
                DBG1(DBG_IKE, "key derivation failed: ENCRYPTION_ALGORITHM "
                        "%N (key size %d) not supported!",
                        encryption_algorithm_names, algo->algorithm, algo->key_size);
                return FAILED;
        }
        key_size = crypter_i->get_key_size(crypter_i);
        
        prf_plus->allocate_bytes(prf_plus, key_size, &key);
        DBG4(DBG_IKE, "Sk_ei secret %B", &key);
        crypter_i->set_key(crypter_i, key);
        chunk_free(&key);
        
        prf_plus->allocate_bytes(prf_plus, key_size, &key);
        DBG4(DBG_IKE, "Sk_er secret %B", &key);
        crypter_r->set_key(crypter_r, key);
        chunk_free(&key);
        
        if (initiator)
        {
                this->crypter_in = crypter_r;
                this->crypter_out = crypter_i;
        }
        else
        {
                this->crypter_in = crypter_i;
                this->crypter_out = crypter_r;
        }
        
        /* SK_pi/SK_pr used for authentication => stored for later */   
        key_size = this->prf->get_key_size(this->prf);
        prf_plus->allocate_bytes(prf_plus, key_size, &key);
        DBG4(DBG_IKE, "Sk_pi secret %B", &key);
        if (initiator)
        {
                this->skp_build = key;
        }
        else
        {
                this->skp_verify = key;
        }
        prf_plus->allocate_bytes(prf_plus, key_size, &key);
        DBG4(DBG_IKE, "Sk_pr secret %B", &key);
        if (initiator)
        {
                this->skp_verify = key;
        }
        else
        {
                this->skp_build = key;
        }
        
        /* all done, prf_plus not needed anymore */
        prf_plus->destroy(prf_plus);
        
        return SUCCESS;
}

/**
 * Implementation of ike_sa_t.add_child_sa.
 */
static void add_child_sa(private_ike_sa_t *this, child_sa_t *child_sa)
{
        this->child_sas->insert_last(this->child_sas, child_sa);
}

/**
 * Implementation of ike_sa_t.get_child_sa.
 */
static child_sa_t* get_child_sa(private_ike_sa_t *this, protocol_id_t protocol,
                                                                u_int32_t spi, bool inbound)
{
        iterator_t *iterator;
        child_sa_t *current, *found = NULL;
        
        iterator = this->child_sas->create_iterator(this->child_sas, TRUE);
        while (iterator->iterate(iterator, (void**)&current))
        {
                if (current->get_spi(current, inbound) == spi &&
                        current->get_protocol(current) == protocol)
                {
                        found = current;
                }
        }
        iterator->destroy(iterator);
        return found;
}

/**
 * Implementation of ike_sa_t.create_child_sa_iterator.
 */
static iterator_t* create_child_sa_iterator(private_ike_sa_t *this)
{
        return this->child_sas->create_iterator(this->child_sas, TRUE);
}

/**
 * Implementation of ike_sa_t.rekey_child_sa.
 */
static status_t rekey_child_sa(private_ike_sa_t *this, protocol_id_t protocol, u_int32_t spi)
{
        child_sa_t *child_sa;
        child_rekey_t *child_rekey;
        
        child_sa = get_child_sa(this, protocol, spi, TRUE);
        if (child_sa)
        {
                child_rekey = child_rekey_create(&this->public, child_sa);
                this->task_manager->queue_task(this->task_manager, &child_rekey->task);
                return this->task_manager->initiate(this->task_manager);
        }
        return FAILED;
}

/**
 * Implementation of ike_sa_t.delete_child_sa.
 */
static status_t delete_child_sa(private_ike_sa_t *this, protocol_id_t protocol, u_int32_t spi)
{
        child_sa_t *child_sa;
        child_delete_t *child_delete;
        
        child_sa = get_child_sa(this, protocol, spi, TRUE);
        if (child_sa)
        {
                child_delete = child_delete_create(&this->public, child_sa);
                this->task_manager->queue_task(this->task_manager, &child_delete->task);
                return this->task_manager->initiate(this->task_manager);
        }
        return FAILED;
}

/**
 * Implementation of ike_sa_t.destroy_child_sa.
 */
static status_t destroy_child_sa(private_ike_sa_t *this, protocol_id_t protocol,
                                                                 u_int32_t spi)
{
        iterator_t *iterator;
        child_sa_t *child_sa;
        status_t status = NOT_FOUND;
        
        iterator = this->child_sas->create_iterator(this->child_sas, TRUE);
        while (iterator->iterate(iterator, (void**)&child_sa))
        {
                if (child_sa->get_protocol(child_sa) == protocol &&
                        child_sa->get_spi(child_sa, TRUE) == spi)
                {
                        child_sa->destroy(child_sa);
                        iterator->remove(iterator);
                        status = SUCCESS;
                        break;
                }
        }
        iterator->destroy(iterator);
        return status;
}

/**
 * Implementation of public_ike_sa_t.delete.
 */
static status_t delete_(private_ike_sa_t *this)
{
        ike_delete_t *ike_delete;

        switch (this->state)
        {
                case IKE_ESTABLISHED:
                case IKE_REKEYING:
                        ike_delete = ike_delete_create(&this->public, TRUE);
                        this->task_manager->queue_task(this->task_manager, &ike_delete->task);
                        return this->task_manager->initiate(this->task_manager);
                case IKE_CREATED:
                        SIG(IKE_DOWN_SUCCESS, "deleting unestablished IKE_SA");
                        break;
                default:
                        SIG(IKE_DOWN_SUCCESS, "destroying IKE_SA in state %N "
                                "without notification", ike_sa_state_names, this->state);
                        break;
        }
        return DESTROY_ME;
}

/**
 * Implementation of ike_sa_t.rekey.
 */
static status_t rekey(private_ike_sa_t *this)
{
        ike_rekey_t *ike_rekey;
        
        ike_rekey = ike_rekey_create(&this->public, TRUE);
        
        this->task_manager->queue_task(this->task_manager, &ike_rekey->task);
        return this->task_manager->initiate(this->task_manager);
}

/**
 * Implementation of ike_sa_t.reestablish
 */
static status_t reestablish(private_ike_sa_t *this)
{
        task_t *task;
        
        task = (task_t*)ike_reauth_create(&this->public);
        this->task_manager->queue_task(this->task_manager, task);
        
        return this->task_manager->initiate(this->task_manager);
}

/**
 * Implementation of ike_sa_t.roam.
 */
static status_t roam(private_ike_sa_t *this, bool address)
{
        host_t *me, *other;
        ike_mobike_t *mobike;
        
        /* responder just updates the peer about changed address config */
        if (!this->ike_sa_id->is_initiator(this->ike_sa_id))
        {
                if (supports_extension(this, EXT_MOBIKE) && address)
                {
                        DBG1(DBG_IKE, "sending address list update using MOBIKE");
                        mobike = ike_mobike_create(&this->public, TRUE);
                        this->task_manager->queue_task(this->task_manager, (task_t*)mobike);
                        return this->task_manager->initiate(this->task_manager);
                }
                return SUCCESS;
        }
        
        /* get best address pair to use */
        other = this->other_host;
        me = charon->kernel_interface->get_source_addr(charon->kernel_interface,
                                                                                                   other);
        
        set_condition(this, COND_STALE, FALSE);
        if (me)
        {
                if (me->ip_equals(me, this->my_host) &&
                        other->ip_equals(other, this->other_host))
                {
                        DBG2(DBG_IKE, "keeping connection path %H - %H", this->other_host, me);
                        me->destroy(me);
                        return SUCCESS;
                }
                me->destroy(me);
        }
        
        /* update addresses with mobike, if supported ... */
        if (supports_extension(this, EXT_MOBIKE))
        {
                DBG1(DBG_IKE, "requesting address change using MOBIKE");
                mobike = ike_mobike_create(&this->public, TRUE);
                mobike->roam(mobike, address);
                this->task_manager->queue_task(this->task_manager, (task_t*)mobike);
                return this->task_manager->initiate(this->task_manager);
        }
        DBG1(DBG_IKE, "reestablishing IKE_SA due address change");
        /* ... reestablish if not */
        return reestablish(this);
}

/**
 * Implementation of ike_sa_t.inherit.
 */
static status_t inherit(private_ike_sa_t *this, private_ike_sa_t *other)
{
        child_sa_t *child_sa;
        host_t *ip;
        
        /* apply hosts and ids */
        this->my_host->destroy(this->my_host);
        this->other_host->destroy(this->other_host);
        this->my_id->destroy(this->my_id);
        this->other_id->destroy(this->other_id);
        this->my_host = other->my_host->clone(other->my_host);
        this->other_host = other->other_host->clone(other->other_host);
        this->my_id = other->my_id->clone(other->my_id);
        this->other_id = other->other_id->clone(other->other_id);
        
        /* apply virtual assigned IPs... */
        if (other->my_virtual_ip)
        {
                this->my_virtual_ip = other->my_virtual_ip;
                other->my_virtual_ip = NULL;
        }
        if (other->other_virtual_ip)
        {
                this->other_virtual_ip = other->other_virtual_ip;
                other->other_virtual_ip = NULL;
        }
        
        /* ... and DNS servers */
        while (other->dns_servers->remove_last(other->dns_servers, 
                                                                                   (void**)&ip) == SUCCESS)
        {
                this->dns_servers->insert_first(this->dns_servers, ip);
        }
        
        /* adopt all children */
        while (other->child_sas->remove_last(other->child_sas,
                                                                                 (void**)&child_sa) == SUCCESS)
        {
                this->child_sas->insert_first(this->child_sas, (void*)child_sa);
        }
        
        /* move pending tasks to the new IKE_SA */
        this->task_manager->adopt_tasks(this->task_manager, other->task_manager);
        
        /* we have to initate here, there may be new tasks to handle */
        return this->task_manager->initiate(this->task_manager);
}

/**
 * Implementation of ike_sa_t.remove_dns_server
 */
static void remove_dns_servers(private_ike_sa_t *this)
{
        FILE *file;
        struct stat stats;
        chunk_t contents, line, orig_line, token;
        char string[INET6_ADDRSTRLEN];
        host_t *ip;
        iterator_t *iterator;
        
        if (this->dns_servers->get_count(this->dns_servers) == 0)
        {
                /* don't touch anything if we have no nameservers installed */
                return;
        }
        
        file = fopen(RESOLV_CONF, "r");
        if (file == NULL || stat(RESOLV_CONF, &stats) != 0)
        {
                DBG1(DBG_IKE, "unable to open DNS configuration file %s: %s",
                         RESOLV_CONF, strerror(errno));
                return;
        }
        
        contents = chunk_alloca((size_t)stats.st_size);
        
        if (fread(contents.ptr, 1, contents.len, file) != contents.len)
        {
                DBG1(DBG_IKE, "unable to read DNS configuration file: %s", strerror(errno));
                fclose(file);
                return;
        }
        
        fclose(file);
        file = fopen(RESOLV_CONF, "w");
        if (file == NULL)
        {
                DBG1(DBG_IKE, "unable to open DNS configuration file %s: %s",
                         RESOLV_CONF, strerror(errno));
                return;
        }
        
        iterator = this->dns_servers->create_iterator(this->dns_servers, TRUE);
        while (fetchline(&contents, &line))
        {
                bool found = FALSE;
                orig_line = line;
                if (extract_token(&token, ' ', &line) &&
                        strncasecmp(token.ptr, "nameserver", token.len) == 0)
                {
                        if (!extract_token(&token, ' ', &line))
                        {
                                token = line;
                        }
                        iterator->reset(iterator);
                        while (iterator->iterate(iterator, (void**)&ip))
                        {
                                snprintf(string, sizeof(string), "%H", ip);
                                if (strlen(string) == token.len &&
                                        strncmp(token.ptr, string, token.len) == 0)
                                {
                                        iterator->remove(iterator);
                                        ip->destroy(ip);
                                        found = TRUE;
                                        break;
                                }
                        }
                }               
                
                if (!found)
                {       
                        /* write line untouched back to file */
                        fwrite(orig_line.ptr, orig_line.len, 1, file);
                        fprintf(file, "\n");
                }
        }
        iterator->destroy(iterator);
        fclose(file);
}

/**
 * Implementation of ike_sa_t.add_dns_server
 */
static void add_dns_server(private_ike_sa_t *this, host_t *dns)
{
        FILE *file;
        struct stat stats;
        chunk_t contents;

        DBG1(DBG_IKE, "installing DNS server %H", dns);
        
        file = fopen(RESOLV_CONF, "a+");
        if (file == NULL || stat(RESOLV_CONF, &stats) != 0)
        {
                DBG1(DBG_IKE, "unable to open DNS configuration file %s: %s",
                         RESOLV_CONF, strerror(errno));
                return;
        }

        contents = chunk_alloca(stats.st_size);
        
        if (fread(contents.ptr, 1, contents.len, file) != contents.len)
        {
                DBG1(DBG_IKE, "unable to read DNS configuration file: %s", strerror(errno));
                fclose(file);
                return;
        }
        
        fclose(file);
        file = fopen(RESOLV_CONF, "w");
        if (file == NULL)
        {
                DBG1(DBG_IKE, "unable to open DNS configuration file %s: %s",
                         RESOLV_CONF, strerror(errno));
                return;
        }
        
        if (fprintf(file, "nameserver %H   # added by strongSwan, assigned by %D\n",
                dns, this->other_id) < 0)
        {
                DBG1(DBG_IKE, "unable to write DNS configuration: %s", strerror(errno));
        }
        else
        {
                this->dns_servers->insert_last(this->dns_servers, dns->clone(dns));
        }
        fwrite(contents.ptr, contents.len, 1, file);
        
        fclose(file);   
}

/**
 * Implementation of ike_sa_t.destroy.
 */
static void destroy(private_ike_sa_t *this)
{
        this->child_sas->destroy_offset(this->child_sas, offsetof(child_sa_t, destroy));
        
        DESTROY_IF(this->crypter_in);
        DESTROY_IF(this->crypter_out);
        DESTROY_IF(this->signer_in);
        DESTROY_IF(this->signer_out);
        DESTROY_IF(this->prf);
        DESTROY_IF(this->child_prf);
        chunk_free(&this->skp_verify);
        chunk_free(&this->skp_build);
        
        if (this->my_virtual_ip)
        {
                charon->kernel_interface->del_ip(charon->kernel_interface,
                                                                                 this->my_virtual_ip);
                this->my_virtual_ip->destroy(this->my_virtual_ip);
        }
        DESTROY_IF(this->other_virtual_ip);
        
        remove_dns_servers(this);
        this->dns_servers->destroy_offset(this->dns_servers,
                                                                                                        offsetof(host_t, destroy));
        this->additional_addresses->destroy_offset(this->additional_addresses,
                                                                                                        offsetof(host_t, destroy));
#ifdef P2P      
        if (this->peer_cfg && this->peer_cfg->is_mediation(this->peer_cfg) &&
                        !this->ike_sa_id->is_initiator(this->ike_sa_id))
        {
                // mediation server
                charon->mediation_manager->remove(charon->mediation_manager, this->ike_sa_id);
        }
        DESTROY_IF(this->server_reflexive_host);
#endif /* P2P */
        
        DESTROY_IF(this->my_host);
        DESTROY_IF(this->other_host);
        DESTROY_IF(this->my_id);
        DESTROY_IF(this->other_id);
        
        DESTROY_IF(this->ike_cfg);
        DESTROY_IF(this->peer_cfg);
        
        this->ike_sa_id->destroy(this->ike_sa_id);
        this->task_manager->destroy(this->task_manager);
        free(this);
}

/*
 * Described in header.
 */
ike_sa_t * ike_sa_create(ike_sa_id_t *ike_sa_id)
{
        private_ike_sa_t *this = malloc_thing(private_ike_sa_t);
        static u_int32_t unique_id = 0;
        
        /* Public functions */
        this->public.get_state = (ike_sa_state_t (*)(ike_sa_t*)) get_state;
        this->public.set_state = (void (*)(ike_sa_t*,ike_sa_state_t)) set_state;
        this->public.get_stats = (void (*)(ike_sa_t*,u_int32_t*))get_stats;
        this->public.get_name = (char* (*)(ike_sa_t*))get_name;
        this->public.process_message = (status_t (*)(ike_sa_t*, message_t*)) process_message;
        this->public.initiate = (status_t (*)(ike_sa_t*,child_cfg_t*)) initiate;
        this->public.route = (status_t (*)(ike_sa_t*,child_cfg_t*)) route;
        this->public.unroute = (status_t (*)(ike_sa_t*,u_int32_t)) unroute;
        this->public.acquire = (status_t (*)(ike_sa_t*,u_int32_t)) acquire;
        this->public.get_ike_cfg = (ike_cfg_t* (*)(ike_sa_t*))get_ike_cfg;
        this->public.set_ike_cfg = (void (*)(ike_sa_t*,ike_cfg_t*))set_ike_cfg;
        this->public.get_peer_cfg = (peer_cfg_t* (*)(ike_sa_t*))get_peer_cfg;
        this->public.set_peer_cfg = (void (*)(ike_sa_t*,peer_cfg_t*))set_peer_cfg;
        this->public.get_id = (ike_sa_id_t* (*)(ike_sa_t*)) get_id;
        this->public.get_my_host = (host_t* (*)(ike_sa_t*)) get_my_host;
        this->public.set_my_host = (void (*)(ike_sa_t*,host_t*)) set_my_host;
        this->public.get_other_host = (host_t* (*)(ike_sa_t*)) get_other_host;
        this->public.set_other_host = (void (*)(ike_sa_t*,host_t*)) set_other_host;
        this->public.update_hosts = (void(*)(ike_sa_t*, host_t *me, host_t *other))update_hosts;
        this->public.get_my_id = (identification_t* (*)(ike_sa_t*)) get_my_id;
        this->public.set_my_id = (void (*)(ike_sa_t*,identification_t*)) set_my_id;
        this->public.get_other_id = (identification_t* (*)(ike_sa_t*)) get_other_id;
        this->public.set_other_id = (void (*)(ike_sa_t*,identification_t*)) set_other_id;
        this->public.get_other_ca = (ca_info_t* (*)(ike_sa_t*)) get_other_ca;
        this->public.set_other_ca = (void (*)(ike_sa_t*,ca_info_t*)) set_other_ca;
        this->public.enable_extension = (void(*)(ike_sa_t*, ike_extension_t extension))enable_extension;
        this->public.supports_extension = (bool(*)(ike_sa_t*, ike_extension_t extension))supports_extension;
        this->public.set_condition = (void (*)(ike_sa_t*, ike_condition_t,bool)) set_condition;
        this->public.has_condition = (bool (*)(ike_sa_t*,ike_condition_t)) has_condition;
        this->public.set_pending_updates = (void(*)(ike_sa_t*, u_int32_t updates))set_pending_updates;
        this->public.get_pending_updates = (u_int32_t(*)(ike_sa_t*))get_pending_updates;
        this->public.create_additional_address_iterator = (iterator_t*(*)(ike_sa_t*))create_additional_address_iterator;
        this->public.add_additional_address = (void(*)(ike_sa_t*, host_t *host))add_additional_address;
        this->public.retransmit = (status_t (*)(ike_sa_t *, u_int32_t)) retransmit;
        this->public.delete = (status_t (*)(ike_sa_t*))delete_;
        this->public.destroy = (void (*)(ike_sa_t*))destroy;
        this->public.send_dpd = (status_t (*)(ike_sa_t*)) send_dpd;
        this->public.send_keepalive = (void (*)(ike_sa_t*)) send_keepalive;
        this->public.get_prf = (prf_t* (*)(ike_sa_t*)) get_prf;
        this->public.get_child_prf = (prf_t* (*)(ike_sa_t *)) get_child_prf;
        this->public.get_skp_verify = (chunk_t (*)(ike_sa_t *)) get_skp_verify;
        this->public.get_skp_build = (chunk_t (*)(ike_sa_t *)) get_skp_build;
        this->public.derive_keys = (status_t (*)(ike_sa_t *,proposal_t*,chunk_t,chunk_t,chunk_t,bool,prf_t*,prf_t*)) derive_keys;
        this->public.add_child_sa = (void (*)(ike_sa_t*,child_sa_t*)) add_child_sa;
        this->public.get_child_sa = (child_sa_t* (*)(ike_sa_t*,protocol_id_t,u_int32_t,bool)) get_child_sa;
        this->public.create_child_sa_iterator = (iterator_t* (*)(ike_sa_t*)) create_child_sa_iterator;
        this->public.rekey_child_sa = (status_t (*)(ike_sa_t*,protocol_id_t,u_int32_t)) rekey_child_sa;
        this->public.delete_child_sa = (status_t (*)(ike_sa_t*,protocol_id_t,u_int32_t)) delete_child_sa;
        this->public.destroy_child_sa = (status_t (*)(ike_sa_t*,protocol_id_t,u_int32_t))destroy_child_sa;
        this->public.rekey = (status_t (*)(ike_sa_t*))rekey;
        this->public.reestablish = (status_t (*)(ike_sa_t*))reestablish;
        this->public.roam = (status_t(*)(ike_sa_t*,bool))roam;
        this->public.inherit = (status_t (*)(ike_sa_t*,ike_sa_t*))inherit;
        this->public.generate_message = (status_t (*)(ike_sa_t*,message_t*,packet_t**))generate_message;
        this->public.reset = (void (*)(ike_sa_t*))reset;
        this->public.get_unique_id = (u_int32_t (*)(ike_sa_t*))get_unique_id;
        this->public.set_virtual_ip = (void (*)(ike_sa_t*,bool,host_t*))set_virtual_ip;
        this->public.get_virtual_ip = (host_t* (*)(ike_sa_t*,bool))get_virtual_ip;
        this->public.add_dns_server = (void (*)(ike_sa_t*,host_t*))add_dns_server;
#ifdef P2P
        this->public.get_server_reflexive_host = (host_t* (*)(ike_sa_t*)) get_server_reflexive_host;
        this->public.set_server_reflexive_host = (void (*)(ike_sa_t*,host_t*)) set_server_reflexive_host;
        this->public.initiate_mediation = (status_t (*)(ike_sa_t*,peer_cfg_t*)) initiate_mediation;
        this->public.initiate_mediated = (status_t (*)(ike_sa_t*,host_t*,host_t*,linked_list_t*)) initiate_mediated;
        this->public.relay = (status_t (*)(ike_sa_t*,identification_t*,chunk_t,chunk_t,linked_list_t*,bool)) relay;
        this->public.callback = (status_t (*)(ike_sa_t*,identification_t*)) callback;
        this->public.respond = (status_t (*)(ike_sa_t*,identification_t*,chunk_t)) respond;
#endif /* P2P */
        
        /* initialize private fields */
        this->ike_sa_id = ike_sa_id->clone(ike_sa_id);
        this->child_sas = linked_list_create();
        this->my_host = host_create_any(AF_INET);
        this->other_host = host_create_any(AF_INET);
        this->my_id = identification_create_from_encoding(ID_ANY, chunk_empty);
        this->other_id = identification_create_from_encoding(ID_ANY, chunk_empty);
        this->other_ca = NULL;
        this->extensions = 0;
        this->conditions = 0;
        this->crypter_in = NULL;
        this->crypter_out = NULL;
        this->signer_in = NULL;
        this->signer_out = NULL;
        this->prf = NULL;
        this->skp_verify = chunk_empty;
        this->skp_build = chunk_empty;
        this->child_prf = NULL;
        this->state = IKE_CREATED;
        this->time.inbound = this->time.outbound = time(NULL);
        this->time.established = 0;
        this->time.rekey = 0;
        this->time.delete = 0;
        this->ike_cfg = NULL;
        this->peer_cfg = NULL;
        this->task_manager = task_manager_create(&this->public);
        this->unique_id = ++unique_id;
        this->my_virtual_ip = NULL;
        this->other_virtual_ip = NULL;
        this->dns_servers = linked_list_create();
        this->additional_addresses = linked_list_create();
        this->pending_updates = 0;
        this->keyingtry = 0;
#ifdef P2P
        this->server_reflexive_host = NULL;
#endif /* P2P */
        
        return &this->public;
}