source: mainline/uspace/srv/net/tl/tcp/tcp.c@ ede63e4

/*
 * Copyright (c) 2008 Lukas Mejdrech
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup tcp
 *  @{
 */

/** @file
 *  TCP module implementation.
 *  @see tcp.h
 */

#include <assert.h>
#include <async.h>
#include <fibril_synch.h>
#include <malloc.h>
//TODO remove stdio
#include <stdio.h>

#include <ipc/ipc.h>
#include <ipc/services.h>

#include "../../err.h"
#include "../../messages.h"
#include "../../modules.h"

#include "../../structures/dynamic_fifo.h"
#include "../../structures/packet/packet_client.h"

#include "../../include/checksum.h"
#include "../../include/in.h"
#include "../../include/in6.h"
#include "../../include/inet.h"
#include "../../include/ip_client.h"
#include "../../include/ip_interface.h"
#include "../../include/ip_protocols.h"
#include "../../include/icmp_client.h"
#include "../../include/icmp_interface.h"
#include "../../include/net_interface.h"
#include "../../include/socket_codes.h"
#include "../../include/socket_errno.h"
#include "../../include/tcp_codes.h"

#include "../../socket/socket_core.h"
#include "../../socket/socket_messages.h"

#include "../tl_common.h"
#include "../tl_messages.h"

#include "tcp.h"
#include "tcp_header.h"
#include "tcp_module.h"

/** The TCP window default value.
 */
#define NET_DEFAULT_TCP_WINDOW  10240

/** Initial timeout for new connections.
 */
#define NET_DEFAULT_TCP_INITIAL_TIMEOUT 3000000L

/** Default timeout for closing.
 */
#define NET_DEFAULT_TCP_TIME_WAIT_TIMEOUT       2000L

/** The initial outgoing sequence number.
 */
#define TCP_INITIAL_SEQUENCE_NUMBER             2999

/** Maximum TCP fragment size.
 */
#define MAX_TCP_FRAGMENT_SIZE   65535

/** Free ports pool start.
 */
#define TCP_FREE_PORTS_START    1025

/** Free ports pool end.
 */
#define TCP_FREE_PORTS_END              65535

/** Timeout for connection initialization, SYN sent.
 */
#define TCP_SYN_SENT_TIMEOUT    1000000L

/** The maximum number of timeouts in a row before singaling connection lost.
 */
#define TCP_MAX_TIMEOUTS                8

/** The number of acknowledgements before retransmit.
 */
#define TCP_FAST_RETRANSMIT_COUNT       3

/** Returns a value indicating whether the value is in the interval respecting the possible overflow.
 *  The high end and/or the value may overflow, be lower than the low value.
 *  @param[in] lower The last value before the interval.
 *  @param[in] value The value to be checked.
 *  @param[in] higher_equal The last value in the interval.
 */
#define IS_IN_INTERVAL_OVERFLOW( lower, value, higher_equal )   (((( lower ) < ( value )) && ((( value ) <= ( higher_equal )) || (( higher_equal ) < ( lower )))) || ((( value ) <= ( higher_equal )) && (( higher_equal ) < ( lower ))))

/** Type definition of the TCP timeout.
 *  @see tcp_timeout
 */
typedef struct tcp_timeout      tcp_timeout_t;

/** Type definition of the TCP timeout pointer.
 *  @see tcp_timeout
 */
typedef tcp_timeout_t * tcp_timeout_ref;

/** TCP reply timeout data.
 *  Used as a timeouting fibril argument.
 *  @see tcp_timeout()
 */
struct tcp_timeout{
        /** TCP global data are going to be read only.
         */
        int                                     globals_read_only;
        /** Socket port.
         */
        int                                     port;
        /** Local sockets.
         */
        socket_cores_ref        local_sockets;
        /** Socket identifier.
         */
        int                                     socket_id;
        /** Socket state.
         */
        tcp_socket_state_t      state;
        /** Sent packet sequence number.
         */
        int                                     sequence_number;
        /** Timeout in microseconds.
         */
        suseconds_t                     timeout;
        /** Port map key.
         */
        char *                          key;
        /** Port map key length.
         */
        size_t                          key_length;
};

/** Releases the packet and returns the result.
 *  @param[in] packet The packet queue to be released.
 *  @param[in] result The result to be returned.
 *  @return The result parameter.
 */
int     tcp_release_and_return( packet_t packet, int result );

void    tcp_prepare_operation_header( socket_core_ref socket, tcp_socket_data_ref socket_data, tcp_header_ref header, int synchronize, int finalize );
int     tcp_prepare_timeout( int ( * timeout_function )( void * tcp_timeout_t ), socket_core_ref socket, tcp_socket_data_ref socket_data, size_t sequence_number, tcp_socket_state_t state, suseconds_t timeout, int globals_read_only );
void    tcp_free_socket_data( socket_core_ref socket );
int     tcp_timeout( void * data );
int     tcp_release_after_timeout( void * data );
int     tcp_process_packet( device_id_t device_id, packet_t packet, services_t error );
int     tcp_connect_core( socket_core_ref socket, socket_cores_ref local_sockets, struct sockaddr * addr, socklen_t addrlen );
int     tcp_queue_prepare_packet( socket_core_ref socket, tcp_socket_data_ref socket_data, packet_t packet, size_t data_length );
int     tcp_queue_packet( socket_core_ref socket, tcp_socket_data_ref socket_data, packet_t packet, size_t data_length );
packet_t        tcp_get_packets_to_send( socket_core_ref socket, tcp_socket_data_ref socket_data );
void    tcp_send_packets( device_id_t device_id, packet_t packet );
void    tcp_process_acknowledgement( socket_core_ref socket, tcp_socket_data_ref socket_data, tcp_header_ref header );
packet_t        tcp_send_prepare_packet( socket_core_ref socket, tcp_socket_data_ref socket_data, packet_t packet, size_t data_length, size_t sequence_number );
packet_t        tcp_prepare_copy( socket_core_ref socket, tcp_socket_data_ref socket_data, packet_t packet, size_t data_length, size_t sequence_number );
void    tcp_retransmit_packet( socket_core_ref socket, tcp_socket_data_ref socket_data, size_t sequence_number );
int     tcp_create_notification_packet( packet_t * packet, socket_core_ref socket, tcp_socket_data_ref socket_data, int synchronize, int finalize );
void    tcp_refresh_socket_data( tcp_socket_data_ref socket_data );
void    tcp_initialize_socket_data( tcp_socket_data_ref socket_data );
int     tcp_process_listen( socket_core_ref listening_socket, tcp_socket_data_ref listening_socket_data, tcp_header_ref header, packet_t packet, struct sockaddr * src, struct sockaddr * dest, size_t addrlen );
int     tcp_process_syn_sent( socket_core_ref socket, tcp_socket_data_ref socket_data, tcp_header_ref header, packet_t packet );
int     tcp_process_syn_received( socket_core_ref socket, tcp_socket_data_ref socket_data, tcp_header_ref header, packet_t packet );
int     tcp_process_established( socket_core_ref socket, tcp_socket_data_ref socket_data, tcp_header_ref header, packet_t packet, int fragments, size_t total_length );
int     tcp_queue_received_packet( socket_core_ref socket, tcp_socket_data_ref socket_data, packet_t packet, int fragments, size_t total_length );

int     tcp_received_msg( device_id_t device_id, packet_t packet, services_t receiver, services_t error );
int     tcp_process_client_messages( ipc_callid_t callid, ipc_call_t call );
int     tcp_listen_message( socket_cores_ref local_sockets, int socket_id, int backlog );
int     tcp_connect_message( socket_cores_ref local_sockets, int socket_id, struct sockaddr * addr, socklen_t addrlen );
int     tcp_recvfrom_message( socket_cores_ref local_sockets, int socket_id, int flags, size_t * addrlen );
int     tcp_send_message( socket_cores_ref local_sockets, int socket_id, int fragments, size_t * data_fragment_size, int flags );
int     tcp_accept_message( socket_cores_ref local_sockets, int socket_id, int new_socket_id, size_t * data_fragment_size, size_t * addrlen );
int tcp_close_message( socket_cores_ref local_sockets, int socket_id );

/** TCP global data.
 */
tcp_globals_t   tcp_globals;

int tcp_initialize( async_client_conn_t client_connection ){
        ERROR_DECLARE;

        assert( client_connection );
        fibril_rwlock_initialize( & tcp_globals.lock );
        fibril_rwlock_write_lock( & tcp_globals.lock );
        tcp_globals.icmp_phone = icmp_connect_module( SERVICE_ICMP, ICMP_CONNECT_TIMEOUT );
        tcp_globals.ip_phone = ip_bind_service( SERVICE_IP, IPPROTO_TCP, SERVICE_TCP, client_connection, tcp_received_msg );
        if( tcp_globals.ip_phone < 0 ){
                return tcp_globals.ip_phone;
        }
        ERROR_PROPAGATE( socket_ports_initialize( & tcp_globals.sockets ));
        if( ERROR_OCCURRED( packet_dimensions_initialize( & tcp_globals.dimensions ))){
                socket_ports_destroy( & tcp_globals.sockets );
                return ERROR_CODE;
        }
        tcp_globals.last_used_port = TCP_FREE_PORTS_START - 1;
        fibril_rwlock_write_unlock( & tcp_globals.lock );
        return EOK;
}

int     tcp_received_msg( device_id_t device_id, packet_t packet, services_t receiver, services_t error ){
        ERROR_DECLARE;

        if( receiver != SERVICE_TCP ) return EREFUSED;
        fibril_rwlock_write_lock( & tcp_globals.lock );
        if( ERROR_OCCURRED( tcp_process_packet( device_id, packet, error ))){
                fibril_rwlock_write_unlock( & tcp_globals.lock );
        }
        printf( "receive %d \n", ERROR_CODE );

        return ERROR_CODE;
}

int tcp_process_packet( device_id_t device_id, packet_t packet, services_t error ){
        ERROR_DECLARE;

        size_t                          length;
        size_t                          offset;
        int                                     result;
        tcp_header_ref          header;
        socket_core_ref         socket;
        tcp_socket_data_ref     socket_data;
        packet_t                        next_packet;
        size_t                          total_length;
        uint32_t                        checksum;
        int                                     fragments;
        icmp_type_t                     type;
        icmp_code_t                     code;
        struct sockaddr *       src;
        struct sockaddr *       dest;
        size_t                          addrlen;

        printf( "p1 \n" );
        if( error ){
                switch( error ){
                        case SERVICE_ICMP:
                                // process error
                                result = icmp_client_process_packet( packet, & type, & code, NULL, NULL );
                                if( result < 0 ){
                                        return tcp_release_and_return( packet, result );
                                }
                                length = ( size_t ) result;
                                if( ERROR_OCCURRED( packet_trim( packet, length, 0 ))){
                                        return tcp_release_and_return( packet, ERROR_CODE );
                                }
                                break;
                        default:
                                return tcp_release_and_return( packet, ENOTSUP );
                }
        }

        // TODO process received ipopts?
        result = ip_client_process_packet( packet, NULL, NULL, NULL, NULL, NULL );
//      printf("ip len %d\n", result );
        if( result < 0 ){
                return tcp_release_and_return( packet, result );
        }
        offset = ( size_t ) result;

        length = packet_get_data_length( packet );
//      printf("packet len %d\n", length );
        if( length <= 0 ){
                return tcp_release_and_return( packet, EINVAL );
        }
        if( length < TCP_HEADER_SIZE + offset ){
                return tcp_release_and_return( packet, NO_DATA );
        }

        // trim all but TCP header
        if( ERROR_OCCURRED( packet_trim( packet, offset, 0 ))){
                return tcp_release_and_return( packet, ERROR_CODE );
        }

        // get tcp header
        header = ( tcp_header_ref ) packet_get_data( packet );
        if( ! header ){
                return tcp_release_and_return( packet, NO_DATA );
        }
//      printf( "header len %d, port %d \n", TCP_HEADER_LENGTH( header ), ntohs( header->destination_port ));

        result = packet_get_addr( packet, ( uint8_t ** ) & src, ( uint8_t ** ) & dest );
        if( result <= 0 ){
                return tcp_release_and_return( packet, result );
        }
        addrlen = ( size_t ) result;

        if( ERROR_OCCURRED( tl_set_address_port( src, addrlen, ntohs( header->source_port )))){
                return tcp_release_and_return( packet, ERROR_CODE );
        }

        // find the destination socket
        socket = socket_port_find( & tcp_globals.sockets, ntohs( header->destination_port ), ( const char * ) src, addrlen );
        if( ! socket ){
//              printf("listening?\n");
                // find the listening destination socket
                socket = socket_port_find( & tcp_globals.sockets, ntohs( header->destination_port ), SOCKET_MAP_KEY_LISTENING, 0 );
                if( ! socket ){
                        if( tl_prepare_icmp_packet( tcp_globals.net_phone, tcp_globals.icmp_phone, packet, error ) == EOK ){
                                icmp_destination_unreachable_msg( tcp_globals.icmp_phone, ICMP_PORT_UNREACH, 0, packet );
                        }
                        return EADDRNOTAVAIL;
                }
        }
        printf("socket id %d\n", socket->socket_id );
        socket_data = ( tcp_socket_data_ref ) socket->specific_data;
        assert( socket_data );

        // some data received, clear the timeout counter
        socket_data->timeout_count = 0;

        // count the received packet fragments
        next_packet = packet;
        fragments = 0;
        checksum = 0;
        total_length = 0;
        do{
                ++ fragments;
                length = packet_get_data_length( next_packet );
                if( length <= 0 ){
                        return tcp_release_and_return( packet, NO_DATA );
                }
                total_length += length;
                // add partial checksum if set
                if( ! error ){
                        checksum = compute_checksum( checksum, packet_get_data( packet ), packet_get_data_length( packet ));
                }
        }while(( next_packet = pq_next( next_packet )));
//      printf( "fragments %d of %d bytes\n", fragments, total_length );

//      printf("lock?\n");
        fibril_rwlock_write_lock( socket_data->local_lock );
//      printf("locked\n");
        if( ! error ){
                if( socket_data->state == TCP_SOCKET_LISTEN ){
                        if( socket_data->pseudo_header ){
                                free( socket_data->pseudo_header );
                                socket_data->pseudo_header = NULL;
                                socket_data->headerlen = 0;
                        }
                        if( ERROR_OCCURRED( ip_client_get_pseudo_header( IPPROTO_TCP, src, addrlen, dest, addrlen, total_length, & socket_data->pseudo_header, & socket_data->headerlen ))){
                                fibril_rwlock_write_unlock( socket_data->local_lock );
                                return tcp_release_and_return( packet, ERROR_CODE );
                        }
                }else if( ERROR_OCCURRED( ip_client_set_pseudo_header_data_length( socket_data->pseudo_header, socket_data->headerlen, total_length ))){
                        fibril_rwlock_write_unlock( socket_data->local_lock );
                        return tcp_release_and_return( packet, ERROR_CODE );
                }
                checksum = compute_checksum( checksum, socket_data->pseudo_header, socket_data->headerlen );
                if( flip_checksum( compact_checksum( checksum ))){
                        printf( "checksum err %x -> %x\n", header->checksum, flip_checksum( compact_checksum( checksum )));
                        fibril_rwlock_write_unlock( socket_data->local_lock );
                        if( ! ERROR_OCCURRED( tl_prepare_icmp_packet( tcp_globals.net_phone, tcp_globals.icmp_phone, packet, error ))){
                                // checksum error ICMP
                                icmp_parameter_problem_msg( tcp_globals.icmp_phone, ICMP_PARAM_POINTER, (( size_t ) (( void * ) & header->checksum )) - (( size_t ) (( void * ) header )), packet );
                        }
                        return EINVAL;
                }
        }

        fibril_rwlock_read_unlock( & tcp_globals.lock );

        // TODO error reporting/handling
//      printf( "st %d\n", socket_data->state );
        switch( socket_data->state ){
                case TCP_SOCKET_LISTEN:
                        ERROR_CODE = tcp_process_listen( socket, socket_data, header, packet, src, dest, addrlen );
                        break;
                case TCP_SOCKET_SYN_RECEIVED:
                        ERROR_CODE = tcp_process_syn_received( socket, socket_data, header, packet );
                        break;
                case TCP_SOCKET_SYN_SENT:
                        ERROR_CODE = tcp_process_syn_sent( socket, socket_data, header, packet );
                        break;
                case TCP_SOCKET_FIN_WAIT_1:
                        // ack changing the state to FIN_WAIT_2 gets processed later
                case TCP_SOCKET_FIN_WAIT_2:
                        // fin changing state to LAST_ACK gets processed later
                case TCP_SOCKET_LAST_ACK:
                        // ack releasing the socket get processed later
                case TCP_SOCKET_CLOSING:
                        // ack releasing the socket gets processed later
                case TCP_SOCKET_ESTABLISHED:
                        ERROR_CODE = tcp_process_established( socket, socket_data, header, packet, fragments, total_length );
                        break;
                default:
                        pq_release( tcp_globals.net_phone, packet_get_id( packet ));
        }

        if( ERROR_CODE != EOK ){
                printf( "process %d\n", ERROR_CODE );
                fibril_rwlock_write_unlock( socket_data->local_lock );
        }
        return EOK;
}

int tcp_process_established( socket_core_ref socket, tcp_socket_data_ref socket_data, tcp_header_ref header, packet_t packet, int fragments, size_t total_length ){
        ERROR_DECLARE;

        packet_t        next_packet;
        packet_t        tmp_packet;
        uint32_t        old_incoming;
        size_t          order;
        uint32_t        sequence_number;
        size_t          length;
        size_t          offset;
        uint32_t        new_sequence_number;

        assert( socket );
        assert( socket_data );
        assert( socket->specific_data == socket_data );
        assert( header );
        assert( packet );

        new_sequence_number = ntohl( header->sequence_number );
        old_incoming = socket_data->next_incoming;

        if( header->finalize ){
                socket_data->fin_incoming = new_sequence_number;
        }

//      printf( "pe %d < %d <= %d\n", new_sequence_number, socket_data->next_incoming, new_sequence_number + total_length );
        // trim begining if containing expected data
        if( IS_IN_INTERVAL_OVERFLOW( new_sequence_number, socket_data->next_incoming, new_sequence_number + total_length )){
                // get the acknowledged offset
                if( socket_data->next_incoming < new_sequence_number ){
                        offset = new_sequence_number - socket_data->next_incoming;
                }else{
                        offset = socket_data->next_incoming - new_sequence_number;
                }
//              printf( "offset %d\n", offset );
                new_sequence_number += offset;
                total_length -= offset;
                length = packet_get_data_length( packet );
                // trim the acknowledged data
                while( length <= offset ){
                        // release the acknowledged packets
                        next_packet = pq_next( packet );
                        pq_release( tcp_globals.net_phone, packet_get_id( packet ));
                        packet = next_packet;
                        offset -= length;
                        length = packet_get_data_length( packet );
                }
                if(( offset > 0 )
                && ( ERROR_OCCURRED( packet_trim( packet, offset, 0 )))){
                        return tcp_release_and_return( packet, ERROR_CODE );
                }
                assert( new_sequence_number == socket_data->next_incoming );
        }

        // release if overflowing the window
//      if( IS_IN_INTERVAL_OVERFLOW( socket_data->next_incoming + socket_data->window, new_sequence_number, new_sequence_number + total_length )){
//              return tcp_release_and_return( packet, EOVERFLOW );
//      }

/*
        // trim end if overflowing the window
        if( IS_IN_INTERVAL_OVERFLOW( new_sequence_number, socket_data->next_incoming + socket_data->window, new_sequence_number + total_length )){
                // get the allowed data length
                if( socket_data->next_incoming + socket_data->window < new_sequence_number ){
                        offset = new_sequence_number - socket_data->next_incoming + socket_data->window;
                }else{
                        offset = socket_data->next_incoming + socket_data->window - new_sequence_number;
                }
                next_packet = packet;
                // trim the overflowing data
                while( next_packet && ( offset > 0 )){
                        length = packet_get_data_length( packet );
                        if( length <= offset ){
                                next_packet = pq_next( next_packet );
                        }else if( ERROR_OCCURRED( packet_trim( next_packet, 0, length - offset ))){
                                return tcp_release_and_return( packet, ERROR_CODE );
                        }
                        offset -= length;
                        total_length -= length - offset;
                }
                // release the overflowing packets
                next_packet = pq_next( next_packet );
                if( next_packet ){
                        tmp_packet = next_packet;
                        next_packet = pq_next( next_packet );
                        pq_insert_after( tmp_packet, next_packet );
                        pq_release( tcp_globals.net_phone, packet_get_id( tmp_packet ));
                }
                assert( new_sequence_number + total_length == socket_data->next_incoming + socket_data->window );
        }
*/
        // the expected one arrived?
        if( new_sequence_number == socket_data->next_incoming ){
                printf("expected\n");
                // process acknowledgement
                tcp_process_acknowledgement( socket, socket_data, header );

                // remove the header
                total_length -= TCP_HEADER_LENGTH( header );
                if( ERROR_OCCURRED( packet_trim( packet, TCP_HEADER_LENGTH( header ), 0 ))){
                        return tcp_release_and_return( packet, ERROR_CODE );
                }

                if( total_length ){
                        ERROR_PROPAGATE( tcp_queue_received_packet( socket, socket_data, packet, fragments, total_length ));
                }else{
                        total_length = 1;
                }
                socket_data->next_incoming = old_incoming + total_length;
                packet = socket_data->incoming;
                while( packet ){
                        if( ERROR_OCCURRED( pq_get_order( socket_data->incoming, & order, NULL ))){
                                // remove the corrupted packet
                                next_packet = pq_detach( packet );
                                if( packet == socket_data->incoming ){
                                        socket_data->incoming = next_packet;
                                }
                                pq_release( tcp_globals.net_phone, packet_get_id( packet ));
                                packet = next_packet;
                                continue;
                        }
                        sequence_number = ( uint32_t ) order;
                        if( IS_IN_INTERVAL_OVERFLOW( sequence_number, old_incoming, socket_data->next_incoming )){
                                // move to the next
                                packet = pq_next( packet );
                        // coninual data?
                        }else if( IS_IN_INTERVAL_OVERFLOW( old_incoming, sequence_number, socket_data->next_incoming )){
                                // detach the packet
                                next_packet = pq_detach( packet );
                                if( packet == socket_data->incoming ){
                                        socket_data->incoming = next_packet;
                                }
                                // get data length
                                length = packet_get_data_length( packet );
                                new_sequence_number = sequence_number + length;
                                if( length <= 0 ){
                                        // remove the empty packet
                                        pq_release( tcp_globals.net_phone, packet_get_id( packet ));
                                        packet = next_packet;
                                        continue;
                                }
                                // exactly following
                                if( sequence_number == socket_data->next_incoming ){
                                        // queue received data
                                        ERROR_PROPAGATE( tcp_queue_received_packet( socket, socket_data, packet, 1, packet_get_data_length( packet )));
                                        socket_data->next_incoming = new_sequence_number;
                                        packet = next_packet;
                                        continue;
                                // at least partly following data?
                                }else if( IS_IN_INTERVAL_OVERFLOW( sequence_number, socket_data->next_incoming, new_sequence_number )){
                                        if( socket_data->next_incoming < new_sequence_number ){
                                                length = new_sequence_number - socket_data->next_incoming;
                                        }else{
                                                length = socket_data->next_incoming - new_sequence_number;
                                        }
                                        if( ! ERROR_OCCURRED( packet_trim( packet, length, 0 ))){
                                                // queue received data
                                                ERROR_PROPAGATE( tcp_queue_received_packet( socket, socket_data, packet, 1, packet_get_data_length( packet )));
                                                socket_data->next_incoming = new_sequence_number;
                                                packet = next_packet;
                                                continue;
                                        }
                                }
                                // remove the duplicit or corrupted packet
                                pq_release( tcp_globals.net_phone, packet_get_id( packet ));
                                packet = next_packet;
                                continue;
                        }else{
                                break;
                        }
                }
        }else if( IS_IN_INTERVAL( socket_data->next_incoming, new_sequence_number, socket_data->next_incoming + socket_data->window )){
                printf("in window\n");
                // process acknowledgement
                tcp_process_acknowledgement( socket, socket_data, header );

                // remove the header
                total_length -= TCP_HEADER_LENGTH( header );
                if( ERROR_OCCURRED( packet_trim( packet, TCP_HEADER_LENGTH( header ), 0 ))){
                        return tcp_release_and_return( packet, ERROR_CODE );
                }

                next_packet = pq_detach( packet );
                length = packet_get_data_length( packet );
                tmp_packet = pq_add( socket_data->incoming, packet, new_sequence_number, length );
                if( ! tmp_packet ){
                        // remove the corrupted packets
                        pq_release( tcp_globals.net_phone, packet_get_id( packet ));
                        pq_release( tcp_globals.net_phone, packet_get_id( next_packet ));
                }else{
                        socket_data->incoming = tmp_packet;
                        while( next_packet ){
                                new_sequence_number += length;
                                tmp_packet = pq_detach( next_packet );
                                length = packet_get_data_length( next_packet );
                                if( ERROR_OCCURRED( pq_set_order( next_packet, new_sequence_number, length ))
                                || ERROR_OCCURRED( pq_insert_after( packet, next_packet ))){
                                        pq_release( tcp_globals.net_phone, packet_get_id( next_packet ));
                                }
                                next_packet = tmp_packet;
                        }
                }
        }else{
                printf("unexpected\n");
                // release duplicite or restricted
                pq_release( tcp_globals.net_phone, packet_get_id( packet ));
        }

        // change state according to the acknowledging incoming fin
        if( IS_IN_INTERVAL_OVERFLOW( old_incoming, socket_data->fin_incoming, socket_data->next_incoming )){
                switch( socket_data->state ){
                        case TCP_SOCKET_FIN_WAIT_1:
                        case TCP_SOCKET_FIN_WAIT_2:
                        case TCP_SOCKET_CLOSING:
                                socket_data->state = TCP_SOCKET_CLOSING;
                                break;
                        //case TCP_ESTABLISHED:
                        default:
                                socket_data->state = TCP_SOCKET_CLOSE_WAIT;
                                break;
                }
        }

        packet = tcp_get_packets_to_send( socket, socket_data );
        if( ! packet ){
                // create the notification packet
                ERROR_PROPAGATE( tcp_create_notification_packet( & packet, socket, socket_data, 0, 0 ));
                ERROR_PROPAGATE( tcp_queue_prepare_packet( socket, socket_data, packet, 1 ));
                packet = tcp_send_prepare_packet( socket, socket_data, packet, 1, socket_data->last_outgoing + 1 );
        }
        fibril_rwlock_write_unlock( socket_data->local_lock );
        // send the packet
        tcp_send_packets( socket_data->device_id, packet );
        return EOK;
}

int tcp_queue_received_packet( socket_core_ref socket, tcp_socket_data_ref socket_data, packet_t packet, int fragments, size_t total_length ){
        ERROR_DECLARE;

        packet_dimension_ref    packet_dimension;

        assert( socket );
        assert( socket_data );
        assert( socket->specific_data == socket_data );
        assert( packet );
        assert( fragments >= 1 );
        assert( socket_data->window > total_length );

        // queue the received packet
        if( ERROR_OCCURRED( dyn_fifo_push( & socket->received, packet_get_id( packet ), SOCKET_MAX_RECEIVED_SIZE ))
        || ERROR_OCCURRED( tl_get_ip_packet_dimension( tcp_globals.ip_phone, & tcp_globals.dimensions, socket_data->device_id, & packet_dimension ))){
                return tcp_release_and_return( packet, ERROR_CODE );
        }

        // decrease the window size
        socket_data->window -= total_length;

        // notify the destination socket
        async_msg_5( socket->phone, NET_SOCKET_RECEIVED, ( ipcarg_t ) socket->socket_id, (( packet_dimension->content < socket_data->data_fragment_size ) ? packet_dimension->content : socket_data->data_fragment_size ), 0, 0, ( ipcarg_t ) fragments );
        return EOK;
}

int tcp_process_syn_sent( socket_core_ref socket, tcp_socket_data_ref socket_data, tcp_header_ref header, packet_t packet ){
        ERROR_DECLARE;

        packet_t        next_packet;

        assert( socket );
        assert( socket_data );
        assert( socket->specific_data == socket_data );
        assert( header );
        assert( packet );

        if( header->synchronize ){
                // process acknowledgement
                tcp_process_acknowledgement( socket, socket_data, header );

                socket_data->next_incoming = ntohl( header->sequence_number ) + 1;
                // release additional packets
                next_packet = pq_detach( packet );
                if( next_packet ){
                        pq_release( tcp_globals.net_phone, packet_get_id( next_packet ));
                }
                // trim if longer than the header
                if(( packet_get_data_length( packet ) > sizeof( * header ))
                && ERROR_OCCURRED( packet_trim( packet, 0, packet_get_data_length( packet ) - sizeof( * header )))){
                        return tcp_release_and_return( packet, ERROR_CODE );
                }
                tcp_prepare_operation_header( socket, socket_data, header, 0, 0 );
                fibril_mutex_lock( & socket_data->operation.mutex );
                socket_data->operation.result = tcp_queue_packet( socket, socket_data, packet, 1 );
                if( socket_data->operation.result == EOK ){
                        socket_data->state = TCP_SOCKET_ESTABLISHED;
                        packet = tcp_get_packets_to_send( socket, socket_data );
                        if( packet ){
                                fibril_rwlock_write_unlock( socket_data->local_lock );
                                // send the packet
                                tcp_send_packets( socket_data->device_id, packet );
                                // signal the result
                                fibril_condvar_signal( & socket_data->operation.condvar );
                                fibril_mutex_unlock( & socket_data->operation.mutex );
                                return EOK;
                        }
                }
                fibril_mutex_unlock( & socket_data->operation.mutex );
        }
        return tcp_release_and_return( packet, EINVAL );
}

int tcp_process_listen( socket_core_ref listening_socket, tcp_socket_data_ref listening_socket_data, tcp_header_ref header, packet_t packet, struct sockaddr * src, struct sockaddr * dest, size_t addrlen ){
        ERROR_DECLARE;

        packet_t                        next_packet;
        socket_core_ref         socket;
        tcp_socket_data_ref     socket_data;
        int                                     socket_id;
        int                                     listening_socket_id = listening_socket->socket_id;
        int                                     listening_port = listening_socket->port;

        assert( listening_socket );
        assert( listening_socket_data );
        assert( listening_socket->specific_data == listening_socket_data );
        assert( header );
        assert( packet );

//      printf( "syn %d\n", header->synchronize );
        if( header->synchronize ){
                socket_data = ( tcp_socket_data_ref ) malloc( sizeof( * socket_data ));
                if( ! socket_data ){
                        return tcp_release_and_return( packet, ENOMEM );
                }else{
                        tcp_initialize_socket_data( socket_data );
                        socket_data->local_lock = listening_socket_data->local_lock;
                        socket_data->local_sockets = listening_socket_data->local_sockets;
                        socket_data->listening_socket_id = listening_socket->socket_id;

                        socket_data->next_incoming = ntohl( header->sequence_number );
                        socket_data->treshold = socket_data->next_incoming + ntohs( header->window );

                        socket_data->addrlen = addrlen;
                        socket_data->addr = malloc( socket_data->addrlen );
                        if( ! socket_data->addr ){
                                free( socket_data );
                                return tcp_release_and_return( packet, ENOMEM );
                        }
                        memcpy( socket_data->addr, src, socket_data->addrlen );

                        socket_data->dest_port = ntohs( header->source_port );
                        if( ERROR_OCCURRED( tl_set_address_port( socket_data->addr, socket_data->addrlen, socket_data->dest_port ))){
                                free( socket_data->addr );
                                free( socket_data );
                                pq_release( tcp_globals.net_phone, packet_get_id( packet ));
                                return ERROR_CODE;
                        }

//                      printf( "addr %p\n", socket_data->addr, socket_data->addrlen );
                        // create a socket
                        socket_id = -1;
                        if( ERROR_OCCURRED( socket_create( socket_data->local_sockets, listening_socket->phone, socket_data, & socket_id ))){
                                free( socket_data->addr );
                                free( socket_data );
                                return tcp_release_and_return( packet, ERROR_CODE );
                        }

                        socket_id *= -1;
                        printf("new_sock %d\n", socket_id);
                        socket_data->pseudo_header = listening_socket_data->pseudo_header;
                        socket_data->headerlen = listening_socket_data->headerlen;
                        listening_socket_data->pseudo_header = NULL;
                        listening_socket_data->headerlen = 0;

                        fibril_rwlock_write_unlock( socket_data->local_lock );
//                      printf("list lg\n");
                        fibril_rwlock_write_lock( & tcp_globals.lock );
//                      printf("list locked\n");
                        // find the destination socket
                        listening_socket = socket_port_find( & tcp_globals.sockets, listening_port, SOCKET_MAP_KEY_LISTENING, 0 );
                        if(( ! listening_socket ) || ( listening_socket->socket_id != listening_socket_id )){
                                fibril_rwlock_write_unlock( & tcp_globals.lock );
                                // a shadow may remain until app hangs up
                                return tcp_release_and_return( packet, EOK/*ENOTSOCK*/ );
                        }
//                      printf("port %d\n", listening_socket->port );
                        listening_socket_data = ( tcp_socket_data_ref ) listening_socket->specific_data;
                        assert( listening_socket_data );

//                      printf("list ll\n");
                        fibril_rwlock_write_lock( listening_socket_data->local_lock );
//                      printf("list locked\n");

                        socket = socket_cores_find( listening_socket_data->local_sockets, socket_id );
                        if( ! socket ){
                                // where is the socket?!?
                                fibril_rwlock_write_unlock( & tcp_globals.lock );
                                return ENOTSOCK;
                        }
                        socket_data = ( tcp_socket_data_ref ) socket->specific_data;
                        assert( socket_data );

//                      uint8_t * data = socket_data->addr;
//                      printf( "addr %d of %x %x %x %x-%x %x %x %x-%x %x %x %x-%x %x %x %x\n", socket_data->addrlen, data[ 0 ], data[ 1 ], data[ 2 ], data[ 3 ], data[ 4 ], data[ 5 ], data[ 6 ], data[ 7 ], data[ 8 ], data[ 9 ], data[ 10 ], data[ 11 ], data[ 12 ], data[ 13 ], data[ 14 ], data[ 15 ] );

                        ERROR_CODE = socket_port_add( & tcp_globals.sockets, listening_port, socket, ( const char * ) socket_data->addr, socket_data->addrlen );
                        assert( socket == socket_port_find( & tcp_globals.sockets, listening_port, ( const char * ) socket_data->addr, socket_data->addrlen ));
                        //ERROR_CODE = socket_bind_free_port( & tcp_globals.sockets, socket, TCP_FREE_PORTS_START, TCP_FREE_PORTS_END, tcp_globals.last_used_port );
                        //tcp_globals.last_used_port = socket->port;
//                      printf("bound %d\n", socket->port );
                        fibril_rwlock_write_unlock( & tcp_globals.lock );
                        if( ERROR_CODE != EOK ){
                                socket_destroy( tcp_globals.net_phone, socket->socket_id, socket_data->local_sockets, & tcp_globals.sockets, tcp_free_socket_data );
                                return tcp_release_and_return( packet, ERROR_CODE );
                        }

                        socket_data->state = TCP_SOCKET_LISTEN;
                        socket_data->next_incoming = ntohl( header->sequence_number ) + 1;
                        // release additional packets
                        next_packet = pq_detach( packet );
                        if( next_packet ){
                                pq_release( tcp_globals.net_phone, packet_get_id( next_packet ));
                        }
                        // trim if longer than the header
                        if(( packet_get_data_length( packet ) > sizeof( * header ))
                        && ERROR_OCCURRED( packet_trim( packet, 0, packet_get_data_length( packet ) - sizeof( * header )))){
                                socket_destroy( tcp_globals.net_phone, socket->socket_id, socket_data->local_sockets, & tcp_globals.sockets, tcp_free_socket_data );
                                return tcp_release_and_return( packet, ERROR_CODE );
                        }
                        tcp_prepare_operation_header( socket, socket_data, header, 1, 0 );
                        if( ERROR_OCCURRED( tcp_queue_packet( socket, socket_data, packet, 1 ))){
                                socket_destroy( tcp_globals.net_phone, socket->socket_id, socket_data->local_sockets, & tcp_globals.sockets, tcp_free_socket_data );
                                return ERROR_CODE;
                        }
                        packet = tcp_get_packets_to_send( socket, socket_data );
//                      printf("send %d\n", packet_get_id( packet ));
                        if( ! packet ){
                                socket_destroy( tcp_globals.net_phone, socket->socket_id, socket_data->local_sockets, & tcp_globals.sockets, tcp_free_socket_data );
                                return EINVAL;
                        }else{
                                socket_data->state = TCP_SOCKET_SYN_RECEIVED;
//                              printf("unlock\n");
                                fibril_rwlock_write_unlock( socket_data->local_lock );
                                // send the packet
                                tcp_send_packets( socket_data->device_id, packet );
                                return EOK;
                        }
                }
        }
        return tcp_release_and_return( packet, EINVAL );
}

int     tcp_process_syn_received( socket_core_ref socket, tcp_socket_data_ref socket_data, tcp_header_ref header, packet_t packet ){
        ERROR_DECLARE;

        socket_core_ref         listening_socket;
        tcp_socket_data_ref     listening_socket_data;

        assert( socket );
        assert( socket_data );
        assert( socket->specific_data == socket_data );
        assert( header );
        assert( packet );

        printf("syn_rec\n");
        if( header->acknowledge ){
                // process acknowledgement
                tcp_process_acknowledgement( socket, socket_data, header );

                socket_data->next_incoming = ntohl( header->sequence_number );// + 1;
                pq_release( tcp_globals.net_phone, packet_get_id( packet ));
                socket_data->state = TCP_SOCKET_ESTABLISHED;
                listening_socket = socket_cores_find( socket_data->local_sockets, socket_data->listening_socket_id );
                if( listening_socket ){
                        listening_socket_data = ( tcp_socket_data_ref ) listening_socket->specific_data;
                        assert( listening_socket_data );

                        // queue the received packet
                        if( ! ERROR_OCCURRED( dyn_fifo_push( & listening_socket->accepted, socket->socket_id, listening_socket_data->backlog ))){
                                // notify the destination socket
                                async_msg_5( socket->phone, NET_SOCKET_ACCEPTED, ( ipcarg_t ) listening_socket->socket_id, socket_data->data_fragment_size, TCP_HEADER_SIZE, 0, ( ipcarg_t ) socket->socket_id );
                                fibril_rwlock_write_unlock( socket_data->local_lock );
                                return EOK;
                        }
                }
                // send FIN
                socket_data->state = TCP_SOCKET_FIN_WAIT_1;

                // create the notification packet
                ERROR_PROPAGATE( tcp_create_notification_packet( & packet, socket, socket_data, 0, 1 ));

                // send the packet
                ERROR_PROPAGATE( tcp_queue_packet( socket, socket_data, packet, 1 ));

                // flush packets
                packet = tcp_get_packets_to_send( socket, socket_data );
                fibril_rwlock_write_unlock( socket_data->local_lock );
                if( packet ){
                        // send the packet
                        tcp_send_packets( socket_data->device_id, packet );
                }
                return EOK;
        }else{
                return tcp_release_and_return( packet, EINVAL );
        }
        return EINVAL;
}

void tcp_process_acknowledgement( socket_core_ref socket, tcp_socket_data_ref socket_data, tcp_header_ref header ){
        size_t          number;
        size_t          length;
        packet_t        packet;
        packet_t        next;
        packet_t        acknowledged = NULL;
        packet_t        first;
        uint32_t        old;

        assert( socket );
        assert( socket_data );
        assert( socket->specific_data == socket_data );
        assert( header );

        if( header->acknowledge ){
                number = ntohl( header->acknowledgement_number );
                // if more data acknowledged
                if( number != socket_data->expected ){
                        old = socket_data->expected;
                        if( IS_IN_INTERVAL_OVERFLOW( old, socket_data->fin_outgoing, number )){
                                switch( socket_data->state ){
                                        case TCP_SOCKET_FIN_WAIT_1:
                                                socket_data->state = TCP_SOCKET_FIN_WAIT_2;
                                                break;
                                        case TCP_SOCKET_LAST_ACK:
                                        case TCP_SOCKET_CLOSING:
                                                // fin acknowledged - release the socket in another fibril
                                                tcp_prepare_timeout( tcp_release_after_timeout, socket, socket_data, 0, TCP_SOCKET_TIME_WAIT, NET_DEFAULT_TCP_TIME_WAIT_TIMEOUT, true );
                                                break;
                                        default:
                                                break;
                                }
                        }
                        // update the treshold if higher than set
                        if( number + ntohs( header->window ) > socket_data->expected + socket_data->treshold ){
                                socket_data->treshold = number + ntohs( header->window ) - socket_data->expected;
                        }
                        // set new expected sequence number
                        socket_data->expected = number;
                        socket_data->expected_count = 1;
                        packet = socket_data->outgoing;
                        while( pq_get_order( packet, & number, & length ) == EOK ){
                                if( IS_IN_INTERVAL_OVERFLOW(( uint32_t ) old, ( uint32_t )( number + length ), ( uint32_t ) socket_data->expected )){
                                        next = pq_detach( packet );
                                        if( packet == socket_data->outgoing ){
                                                socket_data->outgoing = next;
                                        }
                                        // add to acknowledged or release
                                        first = pq_add( acknowledged, packet, 0, 0 );
                                        if( first ){
                                                acknowledged = first;
                                        }else{
                                                pq_release( tcp_globals.net_phone, packet_get_id( packet ));
                                        }
                                        packet = next;
                                }else if( old < socket_data->expected ){
                                        break;
                                }
                        }
                        // release acknowledged
                        if( acknowledged ){
                                pq_release( tcp_globals.net_phone, packet_get_id( acknowledged ));
                        }
                        return;
                // if the same as the previous time
                }else if( number == socket_data->expected ){
                        // increase the counter
                        ++ socket_data->expected_count;
                        if( socket_data->expected_count == TCP_FAST_RETRANSMIT_COUNT ){
                                socket_data->expected_count = 1;
                                // TODO retransmit lock
                                //tcp_retransmit_packet( socket, socket_data, number );
                        }
                }
        }
}

int tcp_message( ipc_callid_t callid, ipc_call_t * call, ipc_call_t * answer, int * answer_count ){
        ERROR_DECLARE;

        packet_t        packet;

        assert( call );
        assert( answer );
        assert( answer_count );

        * answer_count = 0;
        switch( IPC_GET_METHOD( * call )){
                case NET_TL_RECEIVED:
                        //fibril_rwlock_read_lock( & tcp_globals.lock );
                        if( ! ERROR_OCCURRED( packet_translate( tcp_globals.net_phone, & packet, IPC_GET_PACKET( call )))){
                                ERROR_CODE = tcp_received_msg( IPC_GET_DEVICE( call ), packet, SERVICE_TCP, IPC_GET_ERROR( call ));
                        }
                        //fibril_rwlock_read_unlock( & tcp_globals.lock );
                        return ERROR_CODE;
                case IPC_M_CONNECT_TO_ME:
                        return tcp_process_client_messages( callid, * call );
        }
        return ENOTSUP;
}

void tcp_refresh_socket_data( tcp_socket_data_ref socket_data ){
        assert( socket_data );

        bzero( socket_data, sizeof( * socket_data ));
        socket_data->state = TCP_SOCKET_INITIAL;
        socket_data->device_id = DEVICE_INVALID_ID;
        socket_data->window = NET_DEFAULT_TCP_WINDOW;
        socket_data->treshold = socket_data->window;
        socket_data->last_outgoing = TCP_INITIAL_SEQUENCE_NUMBER;
        socket_data->timeout = NET_DEFAULT_TCP_INITIAL_TIMEOUT;
        socket_data->acknowledged = socket_data->last_outgoing;
        socket_data->next_outgoing = socket_data->last_outgoing + 1;
        socket_data->expected = socket_data->next_outgoing;
}

void tcp_initialize_socket_data( tcp_socket_data_ref socket_data ){
        assert( socket_data );

        tcp_refresh_socket_data( socket_data );
        fibril_mutex_initialize( & socket_data->operation.mutex );
        fibril_condvar_initialize( & socket_data->operation.condvar );
        socket_data->data_fragment_size = MAX_TCP_FRAGMENT_SIZE;
}

int tcp_process_client_messages( ipc_callid_t callid, ipc_call_t call ){
        int                                             res;
        bool                                    keep_on_going = true;
        socket_cores_t                  local_sockets;
        int                                             app_phone = IPC_GET_PHONE( & call );
        struct sockaddr *               addr;
        size_t                                  addrlen;
        fibril_rwlock_t                 lock;
        ipc_call_t                              answer;
        int                                             answer_count;
        tcp_socket_data_ref             socket_data;
        socket_core_ref                 socket;
        packet_dimension_ref    packet_dimension;

        /*
         * Accept the connection
         *  - Answer the first IPC_M_CONNECT_ME_TO call.
         */
        ipc_answer_0( callid, EOK );

        socket_cores_initialize( & local_sockets );
        fibril_rwlock_initialize( & lock );

        while( keep_on_going ){
                // refresh data
                refresh_answer( & answer, & answer_count );

                callid = async_get_call( & call );
//              printf( "message %d\n", IPC_GET_METHOD( * call ));

                switch( IPC_GET_METHOD( call )){
                        case IPC_M_PHONE_HUNGUP:
                                keep_on_going = false;
                                res = EOK;
                                break;
                        case NET_SOCKET:
                                socket_data = ( tcp_socket_data_ref ) malloc( sizeof( * socket_data ));
                                if( ! socket_data ){
                                        res = ENOMEM;
                                }else{
                                        tcp_initialize_socket_data( socket_data );
                                        socket_data->local_lock = & lock;
                                        socket_data->local_sockets = & local_sockets;
                                        fibril_rwlock_write_lock( & lock );
                                        * SOCKET_SET_SOCKET_ID( answer ) = SOCKET_GET_SOCKET_ID( call );
                                        res = socket_create( & local_sockets, app_phone, socket_data, SOCKET_SET_SOCKET_ID( answer ));
                                        fibril_rwlock_write_unlock( & lock );
                                        if( res == EOK ){
                                                if( tl_get_ip_packet_dimension( tcp_globals.ip_phone, & tcp_globals.dimensions, DEVICE_INVALID_ID, & packet_dimension ) == EOK ){
                                                        * SOCKET_SET_DATA_FRAGMENT_SIZE( answer ) = (( packet_dimension->content < socket_data->data_fragment_size ) ? packet_dimension->content : socket_data->data_fragment_size );
                                                }
//                                              * SOCKET_SET_DATA_FRAGMENT_SIZE( answer ) = MAX_TCP_FRAGMENT_SIZE;
                                                * SOCKET_SET_HEADER_SIZE( answer ) = TCP_HEADER_SIZE;
                                                answer_count = 3;
                                        }else{
                                                free( socket_data );
                                        }
                                }
                                break;
                        case NET_SOCKET_BIND:
                                res = data_receive(( void ** ) & addr, & addrlen );
                                if( res == EOK ){
                                        fibril_rwlock_write_lock( & tcp_globals.lock );
                                        fibril_rwlock_write_lock( & lock );
                                        res = socket_bind( & local_sockets, & tcp_globals.sockets, SOCKET_GET_SOCKET_ID( call ), addr, addrlen, TCP_FREE_PORTS_START, TCP_FREE_PORTS_END, tcp_globals.last_used_port );
                                        if( res == EOK ){
                                                socket = socket_cores_find( & local_sockets, SOCKET_GET_SOCKET_ID( call ));
                                                if( socket ){
                                                        socket_data = ( tcp_socket_data_ref ) socket->specific_data;
                                                        assert( socket_data );
                                                        socket_data->state = TCP_SOCKET_LISTEN;
                                                }
                                        }
                                        fibril_rwlock_write_unlock( & lock );
                                        fibril_rwlock_write_unlock( & tcp_globals.lock );
                                        free( addr );
                                }
                                break;
                        case NET_SOCKET_LISTEN:
                                fibril_rwlock_read_lock( & tcp_globals.lock );
//                              fibril_rwlock_write_lock( & tcp_globals.lock );
                                fibril_rwlock_write_lock( & lock );
                                res = tcp_listen_message( & local_sockets, SOCKET_GET_SOCKET_ID( call ), SOCKET_GET_BACKLOG( call ));
                                fibril_rwlock_write_unlock( & lock );
//                              fibril_rwlock_write_unlock( & tcp_globals.lock );
                                fibril_rwlock_read_unlock( & tcp_globals.lock );
                                break;
                        case NET_SOCKET_CONNECT:
                                res = data_receive(( void ** ) & addr, & addrlen );
                                if( res == EOK ){
                                        // the global lock may be released in the tcp_connect_message() function
                                        fibril_rwlock_write_lock( & tcp_globals.lock );
                                        fibril_rwlock_write_lock( & lock );
                                        res = tcp_connect_message( & local_sockets, SOCKET_GET_SOCKET_ID( call ), addr, addrlen );
                                        if( res != EOK ){
                                                fibril_rwlock_write_unlock( & lock );
                                                fibril_rwlock_write_unlock( & tcp_globals.lock );
                                                free( addr );
                                        }
                                }
                                break;
                        case NET_SOCKET_ACCEPT:
                                fibril_rwlock_read_lock( & tcp_globals.lock );
                                fibril_rwlock_write_lock( & lock );
                                res = tcp_accept_message( & local_sockets, SOCKET_GET_SOCKET_ID( call ), SOCKET_GET_NEW_SOCKET_ID( call ), SOCKET_SET_DATA_FRAGMENT_SIZE( answer ), & addrlen );
                                fibril_rwlock_write_unlock( & lock );
                                fibril_rwlock_read_unlock( & tcp_globals.lock );
                                if( res > 0 ){
                                        * SOCKET_SET_SOCKET_ID( answer ) = res;
                                        * SOCKET_SET_ADDRESS_LENGTH( answer ) = addrlen;
                                        answer_count = 3;
                                }
                                break;
                        case NET_SOCKET_SEND:
                                fibril_rwlock_read_lock( & tcp_globals.lock );
                                fibril_rwlock_write_lock( & lock );
                                res = tcp_send_message( & local_sockets, SOCKET_GET_SOCKET_ID( call ), SOCKET_GET_DATA_FRAGMENTS( call ), SOCKET_SET_DATA_FRAGMENT_SIZE( answer ), SOCKET_GET_FLAGS( call ));
                                if( res != EOK ){
                                        fibril_rwlock_write_unlock( & lock );
                                        fibril_rwlock_read_unlock( & tcp_globals.lock );
                                }else{
                                        answer_count = 2;
                                }
                                break;
                        case NET_SOCKET_SENDTO:
                                res = data_receive(( void ** ) & addr, & addrlen );
                                if( res == EOK ){
                                        fibril_rwlock_read_lock( & tcp_globals.lock );
                                        fibril_rwlock_write_lock( & lock );
                                        res = tcp_send_message( & local_sockets, SOCKET_GET_SOCKET_ID( call ), SOCKET_GET_DATA_FRAGMENTS( call ), SOCKET_SET_DATA_FRAGMENT_SIZE( answer ), SOCKET_GET_FLAGS( call ));
                                        if( res != EOK ){
                                                fibril_rwlock_write_unlock( & lock );
                                                fibril_rwlock_read_unlock( & tcp_globals.lock );
                                        }else{
                                                answer_count = 2;
                                        }
                                        free( addr );
                                }
                                break;
                        case NET_SOCKET_RECV:
                                fibril_rwlock_read_lock( & tcp_globals.lock );
                                fibril_rwlock_write_lock( & lock );
                                res = tcp_recvfrom_message( & local_sockets, SOCKET_GET_SOCKET_ID( call ), SOCKET_GET_FLAGS( call ), NULL );
                                fibril_rwlock_write_unlock( & lock );
                                fibril_rwlock_read_unlock( & tcp_globals.lock );
                                if( res > 0 ){
                                        * SOCKET_SET_READ_DATA_LENGTH( answer ) = res;
                                        answer_count = 1;
                                        res = EOK;
                                }
                                break;
                        case NET_SOCKET_RECVFROM:
                                fibril_rwlock_read_lock( & tcp_globals.lock );
                                fibril_rwlock_write_lock( & lock );
                                res = tcp_recvfrom_message( & local_sockets, SOCKET_GET_SOCKET_ID( call ), SOCKET_GET_FLAGS( call ), & addrlen );
                                fibril_rwlock_write_unlock( & lock );
                                fibril_rwlock_read_unlock( & tcp_globals.lock );
                                if( res > 0 ){
                                        * SOCKET_SET_READ_DATA_LENGTH( answer ) = res;
                                        * SOCKET_SET_ADDRESS_LENGTH( answer ) = addrlen;
                                        answer_count = 3;
                                        res = EOK;
                                }
                                break;
                        case NET_SOCKET_CLOSE:
                                fibril_rwlock_write_lock( & tcp_globals.lock );
                                fibril_rwlock_write_lock( & lock );
                                res = tcp_close_message( & local_sockets, SOCKET_GET_SOCKET_ID( call ));
                                if( res != EOK ){
                                        fibril_rwlock_write_unlock( & lock );
                                        fibril_rwlock_write_unlock( & tcp_globals.lock );
                                }
                                break;
                        case NET_SOCKET_GETSOCKOPT:
                        case NET_SOCKET_SETSOCKOPT:
                        default:
                                res = ENOTSUP;
                                break;
                }

//              printf( "res = %d\n", res );

                answer_call( callid, res, & answer, answer_count );
        }

        printf("release\n");
        // release all local sockets
        socket_cores_release( tcp_globals.net_phone, & local_sockets, & tcp_globals.sockets, tcp_free_socket_data );

        return EOK;
}

int tcp_timeout( void * data ){
        tcp_timeout_ref         timeout = data;
        int                                     keep_write_lock = false;
        socket_core_ref         socket;
        tcp_socket_data_ref     socket_data;

        assert( timeout );

        // sleep the given timeout
        async_usleep( timeout->timeout );
        // lock the globals
        if( timeout->globals_read_only ){
                fibril_rwlock_read_lock( & tcp_globals.lock );
        }else{
                fibril_rwlock_write_lock( & tcp_globals.lock );
        }
        // find the pending operation socket
        socket = socket_port_find( & tcp_globals.sockets, timeout->port, timeout->key, timeout->key_length );
        if( socket && ( socket->socket_id == timeout->socket_id )){
                socket_data = ( tcp_socket_data_ref ) socket->specific_data;
                assert( socket_data );
                if( socket_data->local_sockets == timeout->local_sockets ){
                        fibril_rwlock_write_lock( socket_data->local_lock );
                        if( timeout->sequence_number ){
                                // increase the timeout counter;
                                ++ socket_data->timeout_count;
                                if( socket_data->timeout_count == TCP_MAX_TIMEOUTS ){
                                        // TODO release as connection lost
                                        //tcp_refresh_socket_data( socket_data );
                                }
                                // retransmit
                                // TODO enable retransmit
                                //tcp_retransmit_packet( socket, socket_data, timeout->sequence_number );
                                fibril_rwlock_write_unlock( socket_data->local_lock );
                        }else{
                                fibril_mutex_lock( & socket_data->operation.mutex );
                                // set the timeout operation result if state not changed
                                if( socket_data->state == timeout->state ){
                                        socket_data->operation.result = ETIMEOUT;
                                        // notify the main fibril
                                        fibril_condvar_signal( & socket_data->operation.condvar );
                                        // keep the global write lock
                                        keep_write_lock = true;
                                }else{
                                        // operation is ok, do nothing
                                        // unlocking from now on, so the unlock order does not matter...
                                        fibril_rwlock_write_unlock( socket_data->local_lock );
                                }
                                fibril_mutex_unlock( & socket_data->operation.mutex );
                        }
                }
        }
        // unlock only if no socket
        if( timeout->globals_read_only ){
                fibril_rwlock_read_unlock( & tcp_globals.lock );
        }else if( ! keep_write_lock ){
                // release if not desired
                fibril_rwlock_write_unlock( & tcp_globals.lock );
        }
        // release the timeout structure
        free( timeout );
        return EOK;
}

int tcp_release_after_timeout( void * data ){
        tcp_timeout_ref         timeout = data;
        socket_core_ref         socket;
        tcp_socket_data_ref     socket_data;
        fibril_rwlock_t *       local_lock;

        assert( timeout );

        // sleep the given timeout
        async_usleep( timeout->timeout );
        // lock the globals
        fibril_rwlock_write_lock( & tcp_globals.lock );
        // find the pending operation socket
        socket = socket_port_find( & tcp_globals.sockets, timeout->port, timeout->key, timeout->key_length );
        if( socket && ( socket->socket_id == timeout->socket_id )){
                socket_data = ( tcp_socket_data_ref ) socket->specific_data;
                assert( socket_data );
                if( socket_data->local_sockets == timeout->local_sockets ){
                        local_lock = socket_data->local_lock;
                        fibril_rwlock_write_lock( local_lock );
                        socket_destroy( tcp_globals.net_phone, timeout->socket_id, timeout->local_sockets, & tcp_globals.sockets, tcp_free_socket_data );
                        fibril_rwlock_write_unlock( local_lock );
                }
        }
        // unlock the globals
        fibril_rwlock_write_unlock( & tcp_globals.lock );
        // release the timeout structure
        free( timeout );
        return EOK;
}

void tcp_retransmit_packet( socket_core_ref socket, tcp_socket_data_ref socket_data, size_t sequence_number ){
        packet_t        packet;
        packet_t        copy;
        size_t          data_length;

        assert( socket );
        assert( socket_data );
        assert( socket->specific_data == socket_data );

        // sent packet?
        packet = pq_find( socket_data->outgoing, sequence_number );
        printf("retransmit %d\n", packet_get_id( packet ));
        if( packet ){
                pq_get_order( packet, NULL, & data_length );
                copy = tcp_prepare_copy( socket, socket_data, packet, data_length, sequence_number );
                fibril_rwlock_write_unlock( socket_data->local_lock );
//              printf( "r send %d\n", packet_get_id( packet ));
                if( copy ){
                        tcp_send_packets( socket_data->device_id, copy );
                }
        }else{
                fibril_rwlock_write_unlock( socket_data->local_lock );
        }
}

int tcp_listen_message( socket_cores_ref local_sockets, int socket_id, int backlog ){
        socket_core_ref         socket;
        tcp_socket_data_ref     socket_data;

        assert( local_sockets );

        if( backlog < 0 ) return EINVAL;
        // find the socket
        socket = socket_cores_find( local_sockets, socket_id );
        if( ! socket ) return ENOTSOCK;
        // get the socket specific data
        socket_data = ( tcp_socket_data_ref ) socket->specific_data;
        assert( socket_data );
        // set the backlog
        socket_data->backlog = backlog;
        return EOK;
}

int tcp_connect_message( socket_cores_ref local_sockets, int socket_id, struct sockaddr * addr, socklen_t addrlen ){
        ERROR_DECLARE;

        socket_core_ref                 socket;

        assert( local_sockets );
        assert( addr );
        assert( addrlen > 0 );

        // find the socket
        socket = socket_cores_find( local_sockets, socket_id );
        if( ! socket ) return ENOTSOCK;
        if( ERROR_OCCURRED( tcp_connect_core( socket, local_sockets, addr, addrlen ))){
                tcp_free_socket_data( socket );
                // unbind if bound
                if( socket->port > 0 ){
                        socket_ports_exclude( & tcp_globals.sockets, socket->port );
                        socket->port = 0;
                }
        }
        return ERROR_CODE;
}

int tcp_connect_core( socket_core_ref socket, socket_cores_ref local_sockets, struct sockaddr * addr, socklen_t addrlen ){
        ERROR_DECLARE;

        tcp_socket_data_ref             socket_data;
        packet_t                                packet;

        assert( socket );
        assert( addr );
        assert( addrlen > 0 );

        // get the socket specific data
        socket_data = ( tcp_socket_data_ref ) socket->specific_data;
        assert( socket_data );
        assert( socket->specific_data == socket_data );
        if(( socket_data->state != TCP_SOCKET_INITIAL )
        && (( socket_data->state != TCP_SOCKET_LISTEN ) || ( socket->port <= 0 ))){
                return EINVAL;
        }
        // get the destination port
        ERROR_PROPAGATE( tl_get_address_port( addr, addrlen, & socket_data->dest_port ));
        if( socket->port <= 0 ){
                // try to find a free port
                ERROR_PROPAGATE( socket_bind_free_port( & tcp_globals.sockets, socket, TCP_FREE_PORTS_START, TCP_FREE_PORTS_END, tcp_globals.last_used_port ));
                // set the next port as the search starting port number
                tcp_globals.last_used_port = socket->port;
        }
        ERROR_PROPAGATE( ip_get_route_req( tcp_globals.ip_phone, IPPROTO_TCP, addr, addrlen, & socket_data->device_id, & socket_data->pseudo_header, & socket_data->headerlen ));

        // create the notification packet
        ERROR_PROPAGATE( tcp_create_notification_packet( & packet, socket, socket_data, 1, 0 ));

        // unlock the globals and wait for an operation
        fibril_rwlock_write_unlock( & tcp_globals.lock );

        socket_data->addr = addr;
        socket_data->addrlen = addrlen;
        // send the packet
        if( ERROR_OCCURRED( tcp_queue_packet( socket, socket_data, packet, 1 ))
        || ERROR_OCCURRED( tcp_prepare_timeout( tcp_timeout, socket, socket_data, 0, TCP_SOCKET_INITIAL, NET_DEFAULT_TCP_INITIAL_TIMEOUT, false ))){
                socket_data->addr = NULL;
                socket_data->addrlen = 0;
                fibril_rwlock_write_lock( & tcp_globals.lock );
        }else{
                packet = tcp_get_packets_to_send( socket, socket_data );
                if( packet ){
                        fibril_mutex_lock( & socket_data->operation.mutex );
                        fibril_rwlock_write_unlock( socket_data->local_lock );
                        // send the packet
                        printf( "connecting %d\n", packet_get_id( packet ));
                        tcp_send_packets( socket_data->device_id, packet );
                        // wait for a reply
                        fibril_condvar_wait( & socket_data->operation.condvar, & socket_data->operation.mutex );
                        ERROR_CODE = socket_data->operation.result;
                        if( ERROR_CODE != EOK ){
                                socket_data->addr = NULL;
                                socket_data->addrlen = 0;
                        }
                }else{
                        socket_data->addr = NULL;
                        socket_data->addrlen = 0;
                        ERROR_CODE = EINTR;
                }
        }

        fibril_mutex_unlock( & socket_data->operation.mutex );

        // return the result
        return ERROR_CODE;
}

int tcp_queue_prepare_packet( socket_core_ref socket, tcp_socket_data_ref socket_data, packet_t packet, size_t data_length ){
        ERROR_DECLARE;

        tcp_header_ref  header;

        assert( socket );
        assert( socket_data );
        assert( socket->specific_data == socket_data );

        // get tcp header
        header = ( tcp_header_ref ) packet_get_data( packet );
        if( ! header ) return NO_DATA;
        header->destination_port = htons( socket_data->dest_port );
        header->source_port = htons( socket->port );
        header->sequence_number = htonl( socket_data->next_outgoing );
        if( ERROR_OCCURRED( packet_set_addr( packet, NULL, ( uint8_t * ) socket_data->addr, socket_data->addrlen ))){
                return tcp_release_and_return( packet, EINVAL );
        }
        // remember the outgoing FIN
        if( header->finalize ){
                socket_data->fin_outgoing = socket_data->next_outgoing;
        }
        return EOK;
}

int     tcp_queue_packet( socket_core_ref socket, tcp_socket_data_ref socket_data, packet_t packet, size_t data_length ){
        ERROR_DECLARE;
        packet_t                first;

        assert( socket );
        assert( socket_data );
        assert( socket->specific_data == socket_data );

        ERROR_PROPAGATE( tcp_queue_prepare_packet( socket, socket_data, packet, data_length ));

        first = pq_add( socket_data->outgoing, packet, socket_data->next_outgoing, data_length );
        if( ! first ){
                return tcp_release_and_return( packet, EINVAL );
        }
        socket_data->outgoing = first;
        socket_data->next_outgoing += data_length;
        return EOK;
}

packet_t tcp_get_packets_to_send( socket_core_ref socket, tcp_socket_data_ref socket_data ){
        ERROR_DECLARE;

        packet_t                packet;
        packet_t                copy;
        packet_t                sending = NULL;
        packet_t                previous = NULL;
        size_t                  data_length;

        assert( socket );
        assert( socket_data );
        assert( socket->specific_data == socket_data );

        packet = pq_find( socket_data->outgoing, socket_data->last_outgoing + 1 );
        while( packet ){
                pq_get_order( packet, NULL, & data_length );
                // send only if fits into the window
                // respecting the possible overflow
                if( IS_IN_INTERVAL_OVERFLOW(( uint32_t ) socket_data->last_outgoing, ( uint32_t )( socket_data->last_outgoing + data_length ), ( uint32_t )( socket_data->expected + socket_data->treshold ))){
                        copy = tcp_prepare_copy( socket, socket_data, packet, data_length, socket_data->last_outgoing + 1 );
                        if( ! copy ){
                                return sending;
                        }
                        if( ! sending ){
                                sending = copy;
                        }else{
                                if( ERROR_OCCURRED( pq_insert_after( previous, copy ))){
                                        pq_release( tcp_globals.net_phone, packet_get_id( copy ));
                                        return sending;
                                }
                        }
                        previous = copy;
                        packet = pq_next( packet );
                        // overflow occurred ?
                        if(( ! packet ) && ( socket_data->last_outgoing > socket_data->next_outgoing )){
                                printf("gpts overflow\n");
                                // continue from the beginning
                                packet = socket_data->outgoing;
                        }
                        socket_data->last_outgoing += data_length;
                }else{
                        break;
                }
        }
        return sending;
}

packet_t tcp_send_prepare_packet( socket_core_ref socket, tcp_socket_data_ref socket_data, packet_t packet, size_t data_length, size_t sequence_number ){
        ERROR_DECLARE;

        tcp_header_ref  header;
        uint32_t                checksum;

        assert( socket );
        assert( socket_data );
        assert( socket->specific_data == socket_data );

        // adjust the pseudo header
        if( ERROR_OCCURRED( ip_client_set_pseudo_header_data_length( socket_data->pseudo_header, socket_data->headerlen, packet_get_data_length( packet )))){
                pq_release( tcp_globals.net_phone, packet_get_id( packet ));
                return NULL;
        }

        // get the header
        header = ( tcp_header_ref ) packet_get_data( packet );
        if( ! header ){
                pq_release( tcp_globals.net_phone, packet_get_id( packet ));
                return NULL;
        }
        assert( ntohl( header->sequence_number ) == sequence_number );

        // adjust the header
        if( socket_data->next_incoming ){
                header->acknowledgement_number = htonl( socket_data->next_incoming );
                header->acknowledge = 1;
        }
        header->window = htons( socket_data->window );

        // checksum
        header->checksum = 0;
        checksum = compute_checksum( 0, socket_data->pseudo_header, socket_data->headerlen );
        checksum = compute_checksum( checksum, ( uint8_t * ) packet_get_data( packet ), packet_get_data_length( packet ));
        header->checksum = htons( flip_checksum( compact_checksum( checksum )));
        // prepare the packet
        if( ERROR_OCCURRED( ip_client_prepare_packet( packet, IPPROTO_TCP, 0, 0, 0, 0 ))
        // prepare the timeout
        || ERROR_OCCURRED( tcp_prepare_timeout( tcp_timeout, socket, socket_data, sequence_number, socket_data->state, socket_data->timeout, true ))){
                pq_release( tcp_globals.net_phone, packet_get_id( packet ));
                return NULL;
        }
        return packet;
}

packet_t tcp_prepare_copy( socket_core_ref socket, tcp_socket_data_ref socket_data, packet_t packet, size_t data_length, size_t sequence_number ){
        packet_t                copy;

        assert( socket );
        assert( socket_data );
        assert( socket->specific_data == socket_data );

        // make a copy of the packet
        copy = packet_get_copy( tcp_globals.net_phone, packet );
        if( ! copy ) return NULL;

        return tcp_send_prepare_packet( socket, socket_data, copy, data_length, sequence_number );
}

void tcp_send_packets( device_id_t device_id, packet_t packet ){
        packet_t        next;

        while( packet ){
                next = pq_detach( packet );
                ip_send_msg( tcp_globals.ip_phone, device_id, packet, SERVICE_TCP, 0 );
                packet = next;
        }
}

void tcp_prepare_operation_header( socket_core_ref socket, tcp_socket_data_ref socket_data, tcp_header_ref header, int synchronize, int finalize ){
        assert( socket );
        assert( socket_data );
        assert( socket->specific_data == socket_data );
        assert( header );

        bzero( header, sizeof( * header ));
        header->source_port = htons( socket->port );
        header->source_port = htons( socket_data->dest_port );
        header->header_length = TCP_COMPUTE_HEADER_LENGTH( sizeof( * header ));
        header->synchronize = synchronize;
        header->finalize = finalize;
}

int tcp_prepare_timeout( int ( * timeout_function )( void * tcp_timeout_t ), socket_core_ref socket, tcp_socket_data_ref socket_data, size_t sequence_number, tcp_socket_state_t state, suseconds_t timeout, int globals_read_only ){
        tcp_timeout_ref operation_timeout;
        fid_t                   fibril;

        assert( socket );
        assert( socket_data );
        assert( socket->specific_data == socket_data );

        // prepare the timeout with key bundle structure
        operation_timeout = malloc( sizeof( * operation_timeout ) + socket->key_length + 1 );
        if( ! operation_timeout ) return ENOMEM;
        bzero( operation_timeout, sizeof( * operation_timeout ));
        operation_timeout->globals_read_only = globals_read_only;
        operation_timeout->port = socket->port;
        operation_timeout->local_sockets = socket_data->local_sockets;
        operation_timeout->socket_id = socket->socket_id;
        operation_timeout->timeout = timeout;
        operation_timeout->sequence_number = sequence_number;
        operation_timeout->state = state;

        // copy the key
        operation_timeout->key = (( char * ) operation_timeout ) + sizeof( * operation_timeout );
        operation_timeout->key_length = socket->key_length;
        memcpy( operation_timeout->key, socket->key, socket->key_length );
        operation_timeout->key[ operation_timeout->key_length ] = '\0';

        // prepare the timeouting thread
        fibril = fibril_create( timeout_function, operation_timeout );
        if( ! fibril ){
                free( operation_timeout );
                return EPARTY;
        }
//      fibril_mutex_lock( & socket_data->operation.mutex );
        // start the timeouting fibril
        fibril_add_ready( fibril );
        //socket_data->state = state;
        return EOK;
}

int tcp_recvfrom_message( socket_cores_ref local_sockets, int socket_id, int flags, size_t * addrlen ){
        ERROR_DECLARE;

        socket_core_ref         socket;
        tcp_socket_data_ref     socket_data;
        int                                     packet_id;
        packet_t                        packet;
        size_t                          length;

        assert( local_sockets );

        // find the socket
        socket = socket_cores_find( local_sockets, socket_id );
        if( ! socket ) return ENOTSOCK;
        // get the socket specific data
        if( ! socket->specific_data ) return NO_DATA;
        socket_data = ( tcp_socket_data_ref ) socket->specific_data;

        // check state
        if(( socket_data->state != TCP_SOCKET_ESTABLISHED ) && ( socket_data->state != TCP_SOCKET_CLOSE_WAIT )){
                return ENOTCONN;
        }

        // send the source address if desired
        if( addrlen ){
                ERROR_PROPAGATE( data_reply( socket_data->addr, socket_data->addrlen ));
                * addrlen = socket_data->addrlen;
        }

        // get the next received packet
        packet_id = dyn_fifo_value( & socket->received );
        if( packet_id < 0 ) return NO_DATA;
        ERROR_PROPAGATE( packet_translate( tcp_globals.net_phone, & packet, packet_id ));

        // reply the packets
        ERROR_PROPAGATE( socket_reply_packets( packet, & length ));

        // release the packet
        dyn_fifo_pop( & socket->received );
        pq_release( tcp_globals.net_phone, packet_get_id( packet ));
        // return the total length
        return ( int ) length;
}

int tcp_send_message( socket_cores_ref local_sockets, int socket_id, int fragments, size_t * data_fragment_size, int flags ){
        ERROR_DECLARE;

        socket_core_ref                 socket;
        tcp_socket_data_ref             socket_data;
        packet_dimension_ref    packet_dimension;
        packet_t                                packet;
        size_t                                  total_length;
        tcp_header_ref                  header;
        int                                             index;
        int                                             result;

        assert( local_sockets );
        assert( data_fragment_size );

        // find the socket
        socket = socket_cores_find( local_sockets, socket_id );
        if( ! socket ) return ENOTSOCK;
        // get the socket specific data
        if( ! socket->specific_data ) return NO_DATA;
        socket_data = ( tcp_socket_data_ref ) socket->specific_data;

        // check state
        if(( socket_data->state != TCP_SOCKET_ESTABLISHED ) && ( socket_data->state != TCP_SOCKET_CLOSE_WAIT )){
                return ENOTCONN;
        }

        ERROR_PROPAGATE( tl_get_ip_packet_dimension( tcp_globals.ip_phone, & tcp_globals.dimensions, socket_data->device_id, & packet_dimension ));

        * data_fragment_size = (( packet_dimension->content < socket_data->data_fragment_size ) ? packet_dimension->content : socket_data->data_fragment_size );

        for( index = 0; index < fragments; ++ index ){
                // read the data fragment
                result = tl_socket_read_packet_data( tcp_globals.net_phone, & packet, TCP_HEADER_SIZE, packet_dimension, socket_data->addr, socket_data->addrlen );
                if( result < 0 ) return result;
                total_length = ( size_t ) result;
                // prefix the tcp header
                header = PACKET_PREFIX( packet, tcp_header_t );
                if( ! header ){
                        return tcp_release_and_return( packet, ENOMEM );
                }
                tcp_prepare_operation_header( socket, socket_data, header, 0, 0 );
                ERROR_PROPAGATE( tcp_queue_packet( socket, socket_data, packet, 0 ));
        }

        // flush packets
        packet = tcp_get_packets_to_send( socket, socket_data );
        fibril_rwlock_write_unlock( socket_data->local_lock );
        fibril_rwlock_read_unlock( & tcp_globals.lock );
        if( packet ){
                // send the packet
                tcp_send_packets( socket_data->device_id, packet );
        }

        return EOK;
}

int tcp_close_message( socket_cores_ref local_sockets, int socket_id ){
        ERROR_DECLARE;

        socket_core_ref                 socket;
        tcp_socket_data_ref             socket_data;
        packet_t                                packet;

        // find the socket
        socket = socket_cores_find( local_sockets, socket_id );
        if( ! socket ) return ENOTSOCK;
        // get the socket specific data
        socket_data = ( tcp_socket_data_ref ) socket->specific_data;
        assert( socket_data );

        // check state
        switch( socket_data->state ){
                case TCP_SOCKET_ESTABLISHED:
                        socket_data->state = TCP_SOCKET_FIN_WAIT_1;
                        break;
                case TCP_SOCKET_CLOSE_WAIT:
                        socket_data->state = TCP_SOCKET_LAST_ACK;
                        break;
//              case TCP_SOCKET_LISTEN:
                default:
                        // just destroy
                        if( ! ERROR_OCCURRED( socket_destroy( tcp_globals.net_phone, socket_id, local_sockets, & tcp_globals.sockets, tcp_free_socket_data ))){
                                fibril_rwlock_write_unlock( socket_data->local_lock );
                                fibril_rwlock_write_unlock( & tcp_globals.lock );
                        }
                        return ERROR_CODE;
        }
        // send FIN
        // TODO should I wait to complete?

        // create the notification packet
        ERROR_PROPAGATE( tcp_create_notification_packet( & packet, socket, socket_data, 0, 1 ));

        // send the packet
        ERROR_PROPAGATE( tcp_queue_packet( socket, socket_data, packet, 1 ));

        // flush packets
        packet = tcp_get_packets_to_send( socket, socket_data );
        fibril_rwlock_write_unlock( socket_data->local_lock );
        fibril_rwlock_write_unlock( & tcp_globals.lock );
        if( packet ){
                // send the packet
                tcp_send_packets( socket_data->device_id, packet );
        }
        return EOK;
}

int tcp_create_notification_packet( packet_t * packet, socket_core_ref socket, tcp_socket_data_ref socket_data, int synchronize, int finalize ){
        ERROR_DECLARE;

        packet_dimension_ref    packet_dimension;
        tcp_header_ref                  header;

        assert( packet );

        // get the device packet dimension
        ERROR_PROPAGATE( tl_get_ip_packet_dimension( tcp_globals.ip_phone, & tcp_globals.dimensions, socket_data->device_id, & packet_dimension ));
        // get a new packet
        * packet = packet_get_4( tcp_globals.net_phone, TCP_HEADER_SIZE, packet_dimension->addr_len, packet_dimension->prefix, packet_dimension->suffix );
        if( ! * packet ) return ENOMEM;
        // allocate space in the packet
        header = PACKET_SUFFIX( * packet, tcp_header_t );
        if( ! header ){
                tcp_release_and_return( * packet, ENOMEM );
        }

        tcp_prepare_operation_header( socket, socket_data, header, synchronize, finalize );
        return EOK;
}

int tcp_accept_message( socket_cores_ref local_sockets, int socket_id, int new_socket_id, size_t * data_fragment_size, size_t * addrlen ){
        ERROR_DECLARE;

        socket_core_ref         accepted;
        socket_core_ref         socket;
        tcp_socket_data_ref     socket_data;
        packet_dimension_ref    packet_dimension;

        assert( local_sockets );
        assert( data_fragment_size );
        assert( addrlen );

        // find the socket
        socket = socket_cores_find( local_sockets, socket_id );
        if( ! socket ) return ENOTSOCK;
        // get the socket specific data
        socket_data = ( tcp_socket_data_ref ) socket->specific_data;
        assert( socket_data );

        // check state
        if( socket_data->state != TCP_SOCKET_LISTEN ){
                return EINVAL;
        }

        do{
                socket_id = dyn_fifo_value( & socket->accepted );
                if( socket_id < 0 ) return ENOTSOCK;

                accepted = socket_cores_find( local_sockets, socket_id );
                if( ! accepted ) return ENOTSOCK;
                // get the socket specific data
                socket_data = ( tcp_socket_data_ref ) accepted->specific_data;
                assert( socket_data );
                // TODO can it be in another state?
                if( socket_data->state == TCP_SOCKET_ESTABLISHED ){
                        ERROR_PROPAGATE( data_reply( socket_data->addr, socket_data->addrlen ));
                        ERROR_PROPAGATE( tl_get_ip_packet_dimension( tcp_globals.ip_phone, & tcp_globals.dimensions, socket_data->device_id, & packet_dimension ));
                        * addrlen = socket_data->addrlen;
                        * data_fragment_size = (( packet_dimension->content < socket_data->data_fragment_size ) ? packet_dimension->content : socket_data->data_fragment_size );
                        if( new_socket_id > 0 ){
                                ERROR_PROPAGATE( socket_cores_update( local_sockets, accepted->socket_id, new_socket_id ));
                                accepted->socket_id = new_socket_id;
                        }
                }
                dyn_fifo_pop( & socket->accepted );
        }while( socket_data->state != TCP_SOCKET_ESTABLISHED );
        printf("ret accept %d\n", accepted->socket_id );
        return accepted->socket_id;
}

void tcp_free_socket_data( socket_core_ref socket ){
        tcp_socket_data_ref             socket_data;

        assert( socket );

        printf( "destroy_socket %d\n", socket->socket_id );

        // get the socket specific data
        socket_data = ( tcp_socket_data_ref ) socket->specific_data;
        assert( socket_data );
        //free the pseudo header
        if( socket_data->pseudo_header ){
                if( socket_data->headerlen ){
                        printf("d pseudo\n");
                        free( socket_data->pseudo_header );
                        socket_data->headerlen = 0;
                }
                socket_data->pseudo_header = NULL;
        }
        socket_data->headerlen = 0;
        // free the address
        if( socket_data->addr ){
                if( socket_data->addrlen ){
                        printf("d addr\n");
                        free( socket_data->addr );
                        socket_data->addrlen = 0;
                }
                socket_data->addr = NULL;
        }
        socket_data->addrlen = 0;
}

int     tcp_release_and_return( packet_t packet, int result ){
        pq_release( tcp_globals.net_phone, packet_get_id( packet ));
        return result;
}

/** @}
 */