source: mainline/uspace/srv/net/tl/tcp/tcp.c@ 46ae62c

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

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

#include <ipc/ipc.h>
#include <ipc/services.h>
#include <ipc/net.h>
#include <ipc/tl.h>
#include <ipc/socket.h>

#include <net/socket_codes.h>
#include <net/ip_protocols.h>
#include <net/in.h>
#include <net/in6.h>
#include <net/inet.h>
#include <net/modules.h>

#include <adt/dynamic_fifo.h>
#include <packet_client.h>
#include <packet_remote.h>
#include <net_checksum.h>
#include <ip_client.h>
#include <ip_interface.h>
#include <icmp_client.h>
#include <icmp_interface.h>
#include <net_interface.h>
#include <socket_core.h>
#include <tl_common.h>
#include <tl_local.h>
#include <tl_interface.h>

/** TCP module name. */
#define NAME    "TCP protocol"

/** 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;
};

static int tcp_release_and_return(packet_t, int);
static void tcp_prepare_operation_header(socket_core_ref, tcp_socket_data_ref,
    tcp_header_ref, int synchronize, int);
static int tcp_prepare_timeout(int (*)(void *), socket_core_ref,
    tcp_socket_data_ref, size_t, tcp_socket_state_t, suseconds_t, int);
static void tcp_free_socket_data(socket_core_ref);

static int tcp_timeout(void *);

static int tcp_release_after_timeout(void *);

static int tcp_process_packet(device_id_t, packet_t, services_t);
static int tcp_connect_core(socket_core_ref, socket_cores_ref,
    struct sockaddr *, socklen_t);
static int tcp_queue_prepare_packet(socket_core_ref, tcp_socket_data_ref,
    packet_t, size_t);
static int tcp_queue_packet(socket_core_ref, tcp_socket_data_ref, packet_t,
    size_t);
static packet_t tcp_get_packets_to_send(socket_core_ref, tcp_socket_data_ref);
static void tcp_send_packets(device_id_t, packet_t);

static void tcp_process_acknowledgement(socket_core_ref, tcp_socket_data_ref,
    tcp_header_ref);
static packet_t tcp_send_prepare_packet(socket_core_ref, tcp_socket_data_ref,
    packet_t, size_t, size_t);
static packet_t tcp_prepare_copy(socket_core_ref, tcp_socket_data_ref, packet_t,
    size_t, size_t);
/* static */ void tcp_retransmit_packet(socket_core_ref, tcp_socket_data_ref,
    size_t);
static int tcp_create_notification_packet(packet_t *, socket_core_ref,
    tcp_socket_data_ref, int, int);
static void tcp_refresh_socket_data(tcp_socket_data_ref);

static void tcp_initialize_socket_data(tcp_socket_data_ref);

static int tcp_process_listen(socket_core_ref, tcp_socket_data_ref,
    tcp_header_ref, packet_t, struct sockaddr *, struct sockaddr *, size_t);
static int tcp_process_syn_sent(socket_core_ref, tcp_socket_data_ref,
    tcp_header_ref, packet_t);
static int tcp_process_syn_received(socket_core_ref, tcp_socket_data_ref,
    tcp_header_ref, packet_t);
static int tcp_process_established(socket_core_ref, tcp_socket_data_ref,
    tcp_header_ref, packet_t, int, size_t);
static int tcp_queue_received_packet(socket_core_ref, tcp_socket_data_ref,
    packet_t, int, size_t);

static int tcp_received_msg(device_id_t, packet_t, services_t, services_t);
static int tcp_process_client_messages(ipc_callid_t, ipc_call_t);

static int tcp_listen_message(socket_cores_ref, int, int);
static int tcp_connect_message(socket_cores_ref, int, struct sockaddr *,
    socklen_t);
static int tcp_recvfrom_message(socket_cores_ref, int, int, size_t *);
static int tcp_send_message(socket_cores_ref, int, int, size_t *, int);
static int tcp_accept_message(socket_cores_ref, int, int, size_t *, size_t *);
static int tcp_close_message(socket_cores_ref, int);

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

/** Initializes the TCP module.
 *
 * @param[in] client_connection The client connection processing function. The
 *                      module skeleton propagates its own one.
 * @returns             EOK on success.
 * @returns             ENOMEM if there is not enough memory left.
 */
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);
        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;

        switch (error) {
        case SERVICE_NONE:
                break;
        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);
        if (result < 0)
                return tcp_release_and_return(packet, result);

        offset = (size_t) result;

        length = packet_get_data_length(packet);
        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) {
                // 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)));

        fibril_rwlock_write_lock(socket_data->local_lock);

        if (error)
                goto has_error_service;
        
        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_NONE(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;
        }

has_error_service:
        fibril_rwlock_read_unlock(&tcp_globals.lock);

        // TODO error reporting/handling
        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_remote(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;

        // 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;
                }

                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_remote(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_remote(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_remote(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_remote(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?
                                }
                                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_NONE(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_remote(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_remote(tcp_globals.net_phone,
                            packet_get_id(packet));
                        pq_release_remote(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_remote(tcp_globals.net_phone,
                                            packet_get_id(next_packet));
                                }
                                next_packet = tmp_packet;
                        }
                }
        } else {
                printf("unexpected\n");
                // release duplicite or restricted
                pq_release_remote(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)
                return tcp_release_and_return(packet, EINVAL);
        
        // 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_remote(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);

        if (!header->synchronize)
                return tcp_release_and_return(packet, EINVAL);

        socket_data = (tcp_socket_data_ref) malloc(sizeof(*socket_data));
        if (!socket_data)
                return tcp_release_and_return(packet, ENOMEM);

        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_remote(tcp_globals.net_phone, packet_get_id(packet));
                return ERROR_CODE;
        }

        // 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);
        fibril_rwlock_write_lock(&tcp_globals.lock);

        // 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*/);
        }
        listening_socket_data =
            (tcp_socket_data_ref) listening_socket->specific_data;
        assert(listening_socket_data);

        fibril_rwlock_write_lock(listening_socket_data->local_lock);

        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);

        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;
        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_remote(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);
        if (!packet) {
                socket_destroy(tcp_globals.net_phone, socket->socket_id,
                    socket_data->local_sockets, &tcp_globals.sockets,
                    tcp_free_socket_data);
                return EINVAL;
        }

        socket_data->state = TCP_SOCKET_SYN_RECEIVED;
        fibril_rwlock_write_unlock(socket_data->local_lock);

        // send the packet
        tcp_send_packets(socket_data->device_id, packet);

        return EOK;
}

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);

        if (!header->acknowledge)
                return tcp_release_and_return(packet, EINVAL);

        // process acknowledgement
        tcp_process_acknowledgement(socket, socket_data, header);

        socket_data->next_incoming = ntohl(header->sequence_number);    // + 1;
        pq_release_remote(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_NONE(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;
}

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)
                return;

        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_remote(tcp_globals.net_phone,
                                            packet_get_id(packet));
                                packet = next;
                        } else if (old < socket_data->expected)
                                break;
                }
                // release acknowledged
                if (acknowledged) {
                        pq_release_remote(tcp_globals.net_phone,
                            packet_get_id(acknowledged));
                }
                return;
                // if the same as the previous time
        }
        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);
                }
        }
}

/** Processes the TCP message.
 *
 * @param[in] callid    The message identifier.
 * @param[in] call      The message parameters.
 * @param[out] answer   The message answer parameters.
 * @param[out] answer_count The last parameter for the actual answer in the
 *                      answer parameter.
 * @returns             EOK on success.
 * @returns             ENOTSUP if the message is not known.
 *
 * @see tcp_interface.h
 * @see IS_NET_TCP_MESSAGE()
 */
int
tcp_message_standalone(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_NONE(packet_translate_remote(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;
        int socket_id;
        size_t addrlen;
        size_t size;
        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;
                                break;
                        }
                        
                        tcp_initialize_socket_data(socket_data);
                        socket_data->local_lock = &lock;
                        socket_data->local_sockets = &local_sockets;
                        fibril_rwlock_write_lock(&lock);
                        socket_id = SOCKET_GET_SOCKET_ID(call);
                        res = socket_create(&local_sockets, app_phone,
                            socket_data, &socket_id);
                        SOCKET_SET_SOCKET_ID(answer, socket_id);
                        fibril_rwlock_write_unlock(&lock);
                        if (res != EOK) {
                                free(socket_data);
                                break;
                        }
                        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;
                        break;

                case NET_SOCKET_BIND:
                        res = data_receive((void **) &addr, &addrlen);
                        if (res != EOK)
                                break;
                        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)
                                break;
                        // 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), &size, &addrlen);
                        SOCKET_SET_DATA_FRAGMENT_SIZE(answer, size);
                        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), &size,
                            SOCKET_GET_FLAGS(call));
                        SOCKET_SET_DATA_FRAGMENT_SIZE(answer, size);
                        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)
                                break;
                        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), &size,
                            SOCKET_GET_FLAGS(call));
                        SOCKET_SET_DATA_FRAGMENT_SIZE(answer, size);
                        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))
                goto out;
        
        socket_data = (tcp_socket_data_ref) socket->specific_data;
        assert(socket_data);
        if (socket_data->local_sockets != timeout->local_sockets)
                goto out;
        
        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 unlocki
                        // order does not matter...
                        fibril_rwlock_write_unlock(socket_data->local_lock);
                }
                fibril_mutex_unlock(&socket_data->operation.mutex);
        }

out:
        // 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)))
                        break;

                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_remote(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;
        }

        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_remote(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_remote(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)) || ERROR_OCCURRED(tcp_prepare_timeout(tcp_timeout, socket,
            socket_data, sequence_number, socket_data->state,
            socket_data->timeout, true))) {
                pq_release_remote(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;  /* FIXME: use another EC */
        }
//      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_remote(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_remote(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_NONE(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_remote(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;
}

/** 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)
{
        pq_release_remote(tcp_globals.net_phone, packet_get_id(packet));
        return result;
}

/** Default thread for new connections.
 *
 * @param[in] iid       The initial message identifier.
 * @param[in] icall     The initial message call structure.
 *
 */
static void tl_client_connection(ipc_callid_t iid, ipc_call_t * icall)
{
        /*
         * Accept the connection
         *  - Answer the first IPC_M_CONNECT_ME_TO call.
         */
        ipc_answer_0(iid, EOK);

        while (true) {
                ipc_call_t answer;
                int answer_count;

                /* Clear the answer structure */
                refresh_answer(&answer, &answer_count);

                /* Fetch the next message */
                ipc_call_t call;
                ipc_callid_t callid = async_get_call(&call);

                /* Process the message */
                int res = tl_module_message_standalone(callid, &call, &answer,
                    &answer_count);

                /*
                 * End if told to either by the message or the processing
                 * result.
                 */
                if ((IPC_GET_METHOD(call) == IPC_M_PHONE_HUNGUP) ||
                    (res == EHANGUP))
                        return;

                /*
                   Answer the message 
                 */
                answer_call(callid, res, &answer, answer_count);
        }
}

/** Starts the module.
 *
 * @returns             EOK on success.
 * @returns             Other error codes as defined for each specific module
 *                      start function.
 */
int
main(int argc, char *argv[])
{
        ERROR_DECLARE;

        /*
           Start the module 
         */
        if (ERROR_OCCURRED(tl_module_start_standalone(tl_client_connection)))
                return ERROR_CODE;

        return EOK;
}

/** @}
 */