source: mainline/uspace/srv/net/tl/tcp/tcp.c@ a8a13d0

/*
 * 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)) != IP_CHECKSUM_ZERO){
                        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);
                if(ERROR_OCCURRED(pq_add(&socket_data->incoming, packet, new_sequence_number, length))){
                        // 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{
                        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);
                        }

                        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, (-1 * 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;
        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
                                        if(pq_add(&acknowledged, packet, 0, 0) != EOK){
                                                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.
         */
        res = EOK;
        answer_count = 0;

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

        while(keep_on_going){

                // answer the call
                answer_call(callid, res, &answer, answer_count);

                // refresh data
                refresh_answer(&answer, &answer_count);

                // get the next call
                callid = async_get_call(&call);

                // process the call
                switch(IPC_GET_METHOD(call)){
                        case IPC_M_PHONE_HUNGUP:
                                keep_on_going = false;
                                res = EHANGUP;
                                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;
                }
        }

        // release the application phone
        ipc_hangup(app_phone);

        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);
                                        fibril_rwlock_write_unlock(socket_data->local_lock);
                                }else{
                                        // 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;

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

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

        if(ERROR_OCCURRED(pq_add(&socket_data->outgoing, packet, socket_data->next_outgoing, data_length))){
                return tcp_release_and_return(packet, ERROR_CODE);
        }
        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;
                }
                socket_id *= -1;

                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;
}

/** @}
 */