source: mainline/uspace/srv/net/tl/udp/udp.c@ 918e9910

/*
 * 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 udp
 *  @{
 */

/** @file
 *  UDP module implementation.
 *  @see udp.h
 */

#include <async.h>
#include <fibril_synch.h>
#include <malloc.h>
#include <stdio.h>

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

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

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

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

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

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

#include "udp.h"
#include "udp_header.h"
#include "udp_module.h"

/** Default UDP checksum computing.
 */
#define NET_DEFAULT_UDP_CHECKSUM_COMPUTING      true

/** Default UDP autobind when sending via unbound sockets.
 */
#define NET_DEFAULT_UDP_AUTOBINDING     true

/** Maximum UDP fragment size.
 */
#define MAX_UDP_FRAGMENT_SIZE   65535

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

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

/** Processes the received UDP packet queue.
 *  Is used as an entry point from the underlying IP module.
 *  Locks the global lock and calls udp_process_packet() function.
 *  @param[in] device_id The receiving device identifier.
 *  @param[in,out] packet The received packet queue.
 *  @param receiver The target service. Ignored parameter.
 *  @param[in] error The packet error reporting service. Prefixes the received packet.
 *  @returns EOK on success.
 *  @returns Other error codes as defined for the udp_process_packet() function.
 */
int     udp_received_msg( device_id_t device_id, packet_t packet, services_t receiver, services_t error );

/** Processes the received UDP packet queue.
 *  Notifies the destination socket application.
 *  Releases the packet on error or sends an ICMP error notification..
 *  @param[in] device_id The receiving device identifier.
 *  @param[in,out] packet The received packet queue.
 *  @param[in] error The packet error reporting service. Prefixes the received packet.
 *  @returns EOK on success.
 *  @returns EINVAL if the packet is not valid.
 *  @returns EINVAL if the stored packet address is not the an_addr_t.
 *  @returns EINVAL if the packet does not contain any data.
 *  @returns NO_DATA if the packet content is shorter than the user datagram header.
 *  @returns ENOMEM if there is not enough memory left.
 *  @returns EADDRNOTAVAIL if the destination socket does not exist.
 *  @returns Other error codes as defined for the ip_client_process_packet() function.
 */
int udp_process_packet( device_id_t device_id, packet_t packet, services_t error );

/** 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     udp_release_and_return( packet_t packet, int result );

/** @name Socket messages processing functions
 */
/*@{*/

/** Processes the socket client messages.
 *  Runs until the client module disconnects.
 *  @param[in] callid The message identifier.
 *  @param[in] call The message parameters.
 *  @returns EOK on success.
 *  @see socket.h
 */
int udp_process_client_messages( ipc_callid_t callid, ipc_call_t call );

/** Sends data from the socket to the remote address.
 *  Binds the socket to a free port if not already connected/bound.
 *  Handles the NET_SOCKET_SENDTO message.
 *  Supports AF_INET and AF_INET6 address families.
 *  @param[in,out] local_sockets The application local sockets.
 *  @param[in] socket_id Socket identifier.
 *  @param[in] addr The destination address.
 *  @param[in] addrlen The address length.
 *  @param[in] fragments The number of data fragments.
 *  @param[out] data_fragment_size The data fragment size in bytes.
 *  @param[in] flags Various send flags.
 *  @returns EOK on success.
 *  @returns EAFNOTSUPPORT if the address family is not supported.
 *  @returns ENOTSOCK if the socket is not found.
 *  @returns EINVAL if the address is invalid.
 *  @returns ENOTCONN if the sending socket is not and cannot be bound.
 *  @returns ENOMEM if there is not enough memory left.
 *  @returns Other error codes as defined for the socket_read_packet_data() function.
 *  @returns Other error codes as defined for the ip_client_prepare_packet() function.
 *  @returns Other error codes as defined for the ip_send_msg() function.
 */
int udp_sendto_message( socket_cores_ref local_sockets, int socket_id, const struct sockaddr * addr, socklen_t addrlen, int fragments, size_t * data_fragment_size, int flags );

/** Receives data to the socket.
 *  Handles the NET_SOCKET_RECVFROM message.
 *  Replies the source address as well.
 *  @param[in] local_sockets The application local sockets.
 *  @param[in] socket_id Socket identifier.
 *  @param[in] flags Various receive flags.
 *  @param[out] addrlen The source address length.
 *  @returns The number of bytes received.
 *  @returns ENOTSOCK if the socket is not found.
 *  @returns NO_DATA if there are no received packets or data.
 *  @returns ENOMEM if there is not enough memory left.
 *  @returns EINVAL if the received address is not an IP address.
 *  @returns Other error codes as defined for the packet_translate() function.
 *  @returns Other error codes as defined for the data_reply() function.
 */
int     udp_recvfrom_message( socket_cores_ref local_sockets, int socket_id, int flags, size_t * addrlen );

/*@}*/

/** UDP global data.
 */
udp_globals_t   udp_globals;

int udp_initialize( async_client_conn_t client_connection ){
        ERROR_DECLARE;

        measured_string_t       names[] = {{ "UDP_CHECKSUM_COMPUTING", 22 }, { "UDP_AUTOBINDING", 15 }};
        measured_string_ref     configuration;
        size_t                          count = sizeof( names ) / sizeof( measured_string_t );
        char *                          data;

        fibril_rwlock_initialize( & udp_globals.lock );
        fibril_rwlock_write_lock( & udp_globals.lock );
        udp_globals.icmp_phone = icmp_connect_module( SERVICE_ICMP, ICMP_CONNECT_TIMEOUT );
        udp_globals.ip_phone = ip_bind_service( SERVICE_IP, IPPROTO_UDP, SERVICE_UDP, client_connection, udp_received_msg );
        if( udp_globals.ip_phone < 0 ){
                return udp_globals.ip_phone;
        }
        // read default packet dimensions
        ERROR_PROPAGATE( ip_packet_size_req( udp_globals.ip_phone, -1, & udp_globals.packet_dimension.addr_len, & udp_globals.packet_dimension.prefix, & udp_globals.packet_dimension.content, & udp_globals.packet_dimension.suffix ));
        ERROR_PROPAGATE( socket_ports_initialize( & udp_globals.sockets ));
        if( ERROR_OCCURRED( packet_dimensions_initialize( & udp_globals.dimensions ))){
                socket_ports_destroy( & udp_globals.sockets );
                return ERROR_CODE;
        }
        udp_globals.packet_dimension.prefix += sizeof( udp_header_t );
        udp_globals.packet_dimension.content -= sizeof( udp_header_t );
        udp_globals.last_used_port = UDP_FREE_PORTS_START - 1;
        // get configuration
        udp_globals.checksum_computing = NET_DEFAULT_UDP_CHECKSUM_COMPUTING;
        udp_globals.autobinding = NET_DEFAULT_UDP_AUTOBINDING;
        configuration = & names[ 0 ];
        ERROR_PROPAGATE( net_get_conf_req( udp_globals.net_phone, & configuration, count, & data ));
        if( configuration ){
                if( configuration[ 0 ].value ){
                        udp_globals.checksum_computing = ( configuration[ 0 ].value[ 0 ] == 'y' );
                }
                if( configuration[ 1 ].value ){
                        udp_globals.autobinding = ( configuration[ 1 ].value[ 0 ] == 'y' );
                }
                net_free_settings( configuration, data );
        }
        fibril_rwlock_write_unlock( & udp_globals.lock );
        return EOK;
}

int     udp_received_msg( device_id_t device_id, packet_t packet, services_t receiver, services_t error ){
        int     result;

        fibril_rwlock_write_lock( & udp_globals.lock );
        result = udp_process_packet( device_id, packet, error );
        if( result != EOK ){
                fibril_rwlock_write_unlock( & udp_globals.lock );
        }

        return result;
}

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

        size_t                  length;
        size_t                  offset;
        int                             result;
        udp_header_ref  header;
        socket_core_ref socket;
        packet_t                next_packet;
        size_t                  total_length;
        uint32_t                checksum;
        int                             fragments;
        packet_t                tmp_packet;
        icmp_type_t             type;
        icmp_code_t             code;
        ip_pseudo_header_ref    ip_header;
        struct sockaddr *               src;
        struct sockaddr *               dest;
        packet_dimension_ref    packet_dimension;

        if( error ){
                switch( error ){
                        case SERVICE_ICMP:
                                // ignore error
                                // length = icmp_client_header_length( packet );
                                // process error
                                result = icmp_client_process_packet( packet, & type, & code, NULL, NULL );
                                if( result < 0 ){
                                        return udp_release_and_return( packet, result );
                                }
                                length = ( size_t ) result;
                                if( ERROR_OCCURRED( packet_trim( packet, length, 0 ))){
                                        return udp_release_and_return( packet, ERROR_CODE );
                                }
                                break;
                        default:
                                return udp_release_and_return( packet, ENOTSUP );
                }
        }
        // TODO process received ipopts?
        result = ip_client_process_packet( packet, NULL, NULL, NULL, NULL, NULL );
        if( result < 0 ){
                return udp_release_and_return( packet, result );
        }
        offset = ( size_t ) result;

        length = packet_get_data_length( packet );
        if( length <= 0 ){
                return udp_release_and_return( packet, EINVAL );
        }
        if( length < UDP_HEADER_SIZE + offset ){
                return udp_release_and_return( packet, NO_DATA );
        }

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

        // get udp header
        header = ( udp_header_ref ) packet_get_data( packet );
        if( ! header ){
                return udp_release_and_return( packet, NO_DATA );
        }
        // find the destination socket
        socket = socket_port_find( & udp_globals.sockets, ntohs( header->destination_port ), SOCKET_MAP_KEY_LISTENING, 0 );
        if( ! socket ){
                if( tl_prepare_icmp_packet( udp_globals.net_phone, udp_globals.icmp_phone, packet, error ) == EOK ){
                        icmp_destination_unreachable_msg( udp_globals.icmp_phone, ICMP_PORT_UNREACH, 0, packet );
                }
                return EADDRNOTAVAIL;
        }

        // count the received packet fragments
        next_packet = packet;
        fragments = 0;
        total_length = ntohs( header->total_length );
        // compute header checksum if set
        if( header->checksum && ( ! error )){
                result = packet_get_addr( packet, ( uint8_t ** ) & src, ( uint8_t ** ) & dest );
                if( result <= 0 ){
                        return udp_release_and_return( packet, result );
                }
                if( ERROR_OCCURRED( ip_client_get_pseudo_header( IPPROTO_UDP, src, result, dest, result, total_length, & ip_header, & length ))){
                        return udp_release_and_return( packet, ERROR_CODE );
                }else{
                        checksum = compute_checksum( 0, ip_header, length );
                        // the udp header checksum will be added with the first fragment later
                        free( ip_header );
                }
        }else{
                header->checksum = 0;
                checksum = 0;
        }

        do{
                ++ fragments;
                length = packet_get_data_length( next_packet );
                if( length <= 0 ){
                        return udp_release_and_return( packet, NO_DATA );
                }
                if( total_length < length ){
                        if( ERROR_OCCURRED( packet_trim( next_packet, 0, length - total_length ))){
                                return udp_release_and_return( packet, ERROR_CODE );
                        }
                        // add partial checksum if set
                        if( header->checksum ){
                                checksum = compute_checksum( checksum, packet_get_data( packet ), packet_get_data_length( packet ));
                        }
                        // relese the rest of the packet fragments
                        tmp_packet = pq_next( next_packet );
                        while( tmp_packet ){
                                next_packet = pq_detach( tmp_packet );
                                pq_release( udp_globals.net_phone, packet_get_id( tmp_packet ));
                                tmp_packet = next_packet;
                        }
                        // exit the loop
                        break;
                }
                total_length -= length;
                // add partial checksum if set
                if( header->checksum ){
                        checksum = compute_checksum( checksum, packet_get_data( packet ), packet_get_data_length( packet ));
                }
        }while(( next_packet = pq_next( next_packet )) && ( total_length > 0 ));

        // check checksum
        if( header->checksum ){
                if( flip_checksum( compact_checksum( checksum )) != IP_CHECKSUM_ZERO ){
                        if( tl_prepare_icmp_packet( udp_globals.net_phone, udp_globals.icmp_phone, packet, error ) == EOK ){
                                // checksum error ICMP
                                icmp_parameter_problem_msg( udp_globals.icmp_phone, ICMP_PARAM_POINTER, (( size_t ) (( void * ) & header->checksum )) - (( size_t ) (( void * ) header )), packet );
                        }
                        return EINVAL;
                }
        }

        // 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( udp_globals.ip_phone, & udp_globals.dimensions, device_id, & packet_dimension ))){
                return udp_release_and_return( packet, ERROR_CODE );
        }

        // notify the destination socket
        fibril_rwlock_write_unlock( & udp_globals.lock );
        async_msg_5( socket->phone, NET_SOCKET_RECEIVED, ( ipcarg_t ) socket->socket_id, packet_dimension->content, 0, 0, ( ipcarg_t ) fragments );
/*      fibril_rwlock_write_unlock( & udp_globals.lock );
        async_msg_5( socket->phone, NET_SOCKET_RECEIVED, ( ipcarg_t ) socket->socket_id, 0, 0, 0, ( ipcarg_t ) fragments );
*/      return EOK;
}

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

        packet_t        packet;

        * answer_count = 0;
        switch( IPC_GET_METHOD( * call )){
                case NET_TL_RECEIVED:
                        if( ! ERROR_OCCURRED( packet_translate( udp_globals.net_phone, & packet, IPC_GET_PACKET( call )))){
                                ERROR_CODE = udp_received_msg( IPC_GET_DEVICE( call ), packet, SERVICE_UDP, IPC_GET_ERROR( call ));
                        }
                        return ERROR_CODE;
                case IPC_M_CONNECT_TO_ME:
                        return udp_process_client_messages( callid, * call );
        }
        return ENOTSUP;
}

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

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

        // The client connection is only in one fibril and therefore no additional locks are needed.

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

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

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

                switch( IPC_GET_METHOD( call )){
                        case IPC_M_PHONE_HUNGUP:
                                keep_on_going = false;
                                res = EOK;
                                break;
                        case NET_SOCKET:
                                fibril_rwlock_write_lock( & lock );
                                * SOCKET_SET_SOCKET_ID( answer ) = SOCKET_GET_SOCKET_ID( call );
                                res = socket_create( & local_sockets, app_phone, NULL, SOCKET_SET_SOCKET_ID( answer ));
                                fibril_rwlock_write_unlock( & lock );
                                if( res == EOK ){
                                        if( tl_get_ip_packet_dimension( udp_globals.ip_phone, & udp_globals.dimensions, DEVICE_INVALID_ID, & packet_dimension ) == EOK ){
                                                * SOCKET_SET_DATA_FRAGMENT_SIZE( answer ) = packet_dimension->content;
                                        }
//                                      * SOCKET_SET_DATA_FRAGMENT_SIZE( answer ) = MAX_UDP_FRAGMENT_SIZE;
                                        * SOCKET_SET_HEADER_SIZE( answer ) = UDP_HEADER_SIZE;
                                        answer_count = 3;
                                }
                                break;
                        case NET_SOCKET_BIND:
                                res = data_receive(( void ** ) & addr, & addrlen );
                                if( res == EOK ){
                                        fibril_rwlock_read_lock( & lock );
                                        fibril_rwlock_write_lock( & udp_globals.lock );
                                        res = socket_bind( & local_sockets, & udp_globals.sockets, SOCKET_GET_SOCKET_ID( call ), addr, addrlen, UDP_FREE_PORTS_START, UDP_FREE_PORTS_END, udp_globals.last_used_port );
                                        fibril_rwlock_write_unlock( & udp_globals.lock );
                                        fibril_rwlock_read_unlock( & lock );
                                        free( addr );
                                }
                                break;
                        case NET_SOCKET_SENDTO:
                                res = data_receive(( void ** ) & addr, & addrlen );
                                if( res == EOK ){
                                        fibril_rwlock_read_lock( & lock );
                                        fibril_rwlock_write_lock( & udp_globals.lock );
                                        res = udp_sendto_message( & local_sockets, SOCKET_GET_SOCKET_ID( call ), addr, addrlen, SOCKET_GET_DATA_FRAGMENTS( call ), SOCKET_SET_DATA_FRAGMENT_SIZE( answer ), SOCKET_GET_FLAGS( call ));
                                        if( res != EOK ){
                                                fibril_rwlock_write_unlock( & udp_globals.lock );
                                        }else{
                                                answer_count = 2;
                                        }
                                        fibril_rwlock_read_unlock( & lock );
                                        free( addr );
                                }
                                break;
                        case NET_SOCKET_RECVFROM:
                                fibril_rwlock_read_lock( & lock );
                                fibril_rwlock_write_lock( & udp_globals.lock );
                                res = udp_recvfrom_message( & local_sockets, SOCKET_GET_SOCKET_ID( call ), SOCKET_GET_FLAGS( call ), & addrlen );
                                fibril_rwlock_write_unlock( & udp_globals.lock );
                                fibril_rwlock_read_unlock( & 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( & lock );
                                fibril_rwlock_write_lock( & udp_globals.lock );
                                res = socket_destroy( udp_globals.net_phone, SOCKET_GET_SOCKET_ID( call ), & local_sockets, & udp_globals.sockets, NULL );
                                fibril_rwlock_write_unlock( & udp_globals.lock );
                                fibril_rwlock_write_unlock( & lock );
                                break;
                        case NET_SOCKET_GETSOCKOPT:
                        case NET_SOCKET_SETSOCKOPT:
                        default:
                                res = ENOTSUP;
                                break;
                }

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

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

        // release all local sockets
        socket_cores_release( udp_globals.net_phone, & local_sockets, & udp_globals.sockets, NULL );

        return EOK;
}

int udp_sendto_message( socket_cores_ref local_sockets, int socket_id, const struct sockaddr * addr, socklen_t addrlen, int fragments, size_t * data_fragment_size, int flags ){
        ERROR_DECLARE;

        socket_core_ref                 socket;
        packet_t                                packet;
        packet_t                                next_packet;
        udp_header_ref                  header;
        int                                             index;
        size_t                                  total_length;
        int                                             result;
        uint16_t                                dest_port;
        uint32_t                                checksum;
        ip_pseudo_header_ref    ip_header;
        size_t                                  headerlen;
        device_id_t                             device_id;
        packet_dimension_ref    packet_dimension;

        ERROR_PROPAGATE( tl_get_address_port( addr, addrlen, & dest_port ));

        socket = socket_cores_find( local_sockets, socket_id );
        if( ! socket ) return ENOTSOCK;

        if(( socket->port <= 0 ) && udp_globals.autobinding ){
                // bind the socket to a random free port if not bound
//              do{
                        // try to find a free port
//                      fibril_rwlock_read_unlock( & udp_globals.lock );
//                      fibril_rwlock_write_lock( & udp_globals.lock );
                        // might be changed in the meantime
//                      if( socket->port <= 0 ){
                                if( ERROR_OCCURRED( socket_bind_free_port( & udp_globals.sockets, socket, UDP_FREE_PORTS_START, UDP_FREE_PORTS_END, udp_globals.last_used_port ))){
//                                      fibril_rwlock_write_unlock( & udp_globals.lock );
//                                      fibril_rwlock_read_lock( & udp_globals.lock );
                                        return ERROR_CODE;
                                }
                                // set the next port as the search starting port number
                                udp_globals.last_used_port = socket->port;
//                      }
//                      fibril_rwlock_write_unlock( & udp_globals.lock );
//                      fibril_rwlock_read_lock( & udp_globals.lock );
                        // might be changed in the meantime
//              }while( socket->port <= 0 );
        }

        if( udp_globals.checksum_computing ){
                if( ERROR_OCCURRED( ip_get_route_req( udp_globals.ip_phone, IPPROTO_UDP, addr, addrlen, & device_id, & ip_header, & headerlen ))){
                        return udp_release_and_return( packet, ERROR_CODE );
                }
                // get the device packet dimension
//              ERROR_PROPAGATE( tl_get_ip_packet_dimension( udp_globals.ip_phone, & udp_globals.dimensions, device_id, & packet_dimension ));
        }
//      }else{
                // do not ask all the time
                ERROR_PROPAGATE( ip_packet_size_req( udp_globals.ip_phone, -1, & udp_globals.packet_dimension.addr_len, & udp_globals.packet_dimension.prefix, & udp_globals.packet_dimension.content, & udp_globals.packet_dimension.suffix ));
                packet_dimension = & udp_globals.packet_dimension;
//      }

        // read the first packet fragment
        result = tl_socket_read_packet_data( udp_globals.net_phone, & packet, UDP_HEADER_SIZE, packet_dimension, addr, addrlen );
        if( result < 0 ) return result;
        total_length = ( size_t ) result;
        if( udp_globals.checksum_computing ){
                checksum = compute_checksum( 0, packet_get_data( packet ), packet_get_data_length( packet ));
        }else{
                checksum = 0;
        }
        // prefix the udp header
        header = PACKET_PREFIX( packet, udp_header_t );
        if( ! header ){
                return udp_release_and_return( packet, ENOMEM );
        }
        bzero( header, sizeof( * header ));
        // read the rest of the packet fragments
        for( index = 1; index < fragments; ++ index ){
                result = tl_socket_read_packet_data( udp_globals.net_phone, & next_packet, 0, packet_dimension, addr, addrlen );
                if( result < 0 ){
                        return udp_release_and_return( packet, result );
                }
                packet = pq_add( packet, next_packet, index, 0 );
                total_length += ( size_t ) result;
                if( udp_globals.checksum_computing ){
                        checksum = compute_checksum( checksum, packet_get_data( next_packet ), packet_get_data_length( next_packet ));
                }
        }
        // set the udp header
        header->source_port = htons(( socket->port > 0 ) ? socket->port : 0 );
        header->destination_port = htons( dest_port );
        header->total_length = htons( total_length + sizeof( * header ));
        header->checksum = 0;
        if( udp_globals.checksum_computing ){
//              if( ERROR_OCCURRED( ip_get_route_req( udp_globals.ip_phone, IPPROTO_UDP, addr, addrlen, & device_id, & ip_header, & headerlen ))){
//                      return udp_release_and_return( packet, ERROR_CODE );
//              }
                if( ERROR_OCCURRED( ip_client_set_pseudo_header_data_length( ip_header, headerlen, total_length + UDP_HEADER_SIZE))){
                        free( ip_header );
                        return udp_release_and_return( packet, ERROR_CODE );
                }
                checksum = compute_checksum( checksum, ip_header, headerlen );
                checksum = compute_checksum( checksum, ( uint8_t * ) header, sizeof( * header ));
                header->checksum = htons( flip_checksum( compact_checksum( checksum )));
                free( ip_header );
        }else{
                device_id = DEVICE_INVALID_ID;
        }
        // prepare the first packet fragment
        if( ERROR_OCCURRED( ip_client_prepare_packet( packet, IPPROTO_UDP, 0, 0, 0, 0 ))){
                return udp_release_and_return( packet, ERROR_CODE );
        }
        // send the packet
        fibril_rwlock_write_unlock( & udp_globals.lock );
        ip_send_msg( udp_globals.ip_phone, device_id, packet, SERVICE_UDP, 0 );
        return EOK;
}

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

        socket_core_ref socket;
        int                             packet_id;
        packet_t                packet;
        udp_header_ref  header;
        struct sockaddr *       addr;
        size_t                  length;
        uint8_t *               data;
        int                             result;

        // find the socket
        socket = socket_cores_find( local_sockets, socket_id );
        if( ! socket ) return ENOTSOCK;
        // get the next received packet
        packet_id = dyn_fifo_value( & socket->received );
        if( packet_id < 0 ) return NO_DATA;
        ERROR_PROPAGATE( packet_translate( udp_globals.net_phone, & packet, packet_id ));
        // get udp header
        data = packet_get_data( packet );
        if( ! data ){
                pq_release( udp_globals.net_phone, packet_id );
                return NO_DATA;
        }
        header = ( udp_header_ref ) data;

        // set the source address port
        result = packet_get_addr( packet, ( uint8_t ** ) & addr, NULL );
        if( ERROR_OCCURRED( tl_set_address_port( addr, result, ntohs( header->source_port )))){
                pq_release( udp_globals.net_phone, packet_id );
                return ERROR_CODE;
        }
        * addrlen = ( size_t ) result;
        // send the source address
        ERROR_PROPAGATE( data_reply( addr, * addrlen ));

        // trim the header
        ERROR_PROPAGATE( packet_trim( packet, UDP_HEADER_SIZE, 0 ));

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

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

int     udp_release_and_return( packet_t packet, int result ){
        pq_release( udp_globals.net_phone, packet_get_id( packet ));
        return result;
}

/** @}
 */