source: mainline/uspace/srv/net/socket/socket_client.c@ 1b053ca2

/*
 * Copyright (c) 2009 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 socket
 *  @{
 */

/** @file
 *  Socket application program interface (API) implementation.
 *  @see socket.h for more information.
 *  This is a part of the network application library.
 */

#include <assert.h>
#include <async.h>
#include <fibril_synch.h>
#include <limits.h>
#include <stdlib.h>

#include <ipc/services.h>

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

#include "../include/in.h"
#include "../include/socket.h"
#include "../include/socket_errno.h"

#include "../structures/dynamic_fifo.h"
#include "../structures/int_map.h"

#include "socket_messages.h"

/** Initial received packet queue size.
 */
#define SOCKET_INITIAL_RECEIVED_SIZE    4

/** Maximum received packet queue size.
 */
#define SOCKET_MAX_RECEIVED_SIZE                0

/** Initial waiting sockets queue size.
 */
#define SOCKET_INITIAL_ACCEPTED_SIZE    1

/** Maximum waiting sockets queue size.
 */
#define SOCKET_MAX_ACCEPTED_SIZE                0

/** Default timeout for connections in microseconds.
 */
#define SOCKET_CONNECT_TIMEOUT  ( 1 * 1000 * 1000 )

/** Maximum number of random attempts to find a new socket identifier before switching to the sequence.
 */
#define SOCKET_ID_TRIES                                 100

/** Type definition of the socket specific data.
 *  @see socket
 */
typedef struct socket   socket_t;

/** Type definition of the socket specific data pointer.
 *  @see socket
 */
typedef socket_t *      socket_ref;

/** Socket specific data.
 *  Each socket lock locks only its structure part and any number of them may be locked simultaneously.
 */
struct socket{
        /** Socket identifier.
         */
        int                                     socket_id;
        /** Parent module phone.
         */
        int                                     phone;
        /** Parent module service.
         */
        services_t                      service;
        /** Underlying protocol header size.
         *  Sending and receiving optimalization.
         */
        size_t                          header_size;
        /** Packet data fragment size.
         *  Sending optimalization.
         */
        size_t                          data_fragment_size;
        /** Sending safety lock.
         *  Locks the header_size and data_fragment_size attributes.
         */
        fibril_rwlock_t         sending_lock;
        /** Received packets queue.
         */
        dyn_fifo_t                      received;
        /** Received packets safety lock.
         *  Used for receiving and receive notifications.
         *  Locks the received attribute.
         */
        fibril_mutex_t          receive_lock;
        /** Received packets signaling.
         *  Signaled upon receive notification.
         */
        fibril_condvar_t        receive_signal;
        /** Waiting sockets queue.
         */
        dyn_fifo_t                      accepted;
        /** Waiting sockets safety lock.
         *  Used for accepting and accept notifications.
         *  Locks the accepted attribute.
         */
        fibril_mutex_t          accept_lock;
        /** Waiting sockets signaling.
         *  Signaled upon accept notification.
         */
        fibril_condvar_t        accept_signal;
        /** The number of blocked functions called.
         *  Used while waiting for the received packets or accepted sockets.
         */
        int                                     blocked;
};

/** Sockets map.
 *  Maps socket identifiers to the socket specific data.
 *  @see int_map.h
 */
INT_MAP_DECLARE( sockets, socket_t );

/** Socket client library global data.
 */
static struct socket_client_globals {
        /** TCP module phone.
         */
        int     tcp_phone;
        /** UDP module phone.
         */
        int     udp_phone;
//      /** The last socket identifier.
//       */
//      int last_id;
        /** Active sockets.
         */
        sockets_ref     sockets;
        /** Safety lock.
         *  Write lock is used only for adding or removing sockets.
         *  When locked for writing, no other socket locks need to be locked.
         *  When locked for reading, any other socket locks may be locked.
         *  No socket lock may be locked if this lock is unlocked.
         */
        fibril_rwlock_t lock;
} socket_globals = {
        .tcp_phone = -1,
        .udp_phone = -1,
//      .last_id = 0,
        .sockets = NULL,
        .lock = {
                .readers = 0,
                .writers = 0,
                .waiters = {
                        .prev = & socket_globals.lock.waiters,
                        .next = & socket_globals.lock.waiters
                }
        }
};

INT_MAP_IMPLEMENT( sockets, socket_t );

/** Returns the TCP module phone.
 *  Connects to the TCP module if necessary.
 *  @returns The TCP module phone.
 *  @returns Other error codes as defined for the bind_service_timeout() function.
 */
static int      socket_get_tcp_phone( void );

/** Returns the UDP module phone.
 *  Connects to the UDP module if necessary.
 *  @returns The UDP module phone.
 *  @returns Other error codes as defined for the bind_service_timeout() function.
 */
static int      socket_get_udp_phone( void );

/** Returns the active sockets.
 *  @returns The active sockets.
 */
static sockets_ref      socket_get_sockets( void );

/** Tries to find a new free socket identifier.
 *      @returns The new socket identifier.
 *  @returns ELIMIT if there is no socket identifier available.
 */
static int      socket_generate_new_id( void );

/** Default thread for new connections.
 *  @param[in] iid The initial message identifier.
 *  @param[in] icall The initial message call structure.
 */
void    socket_connection( ipc_callid_t iid, ipc_call_t * icall );

/** Sends message to the socket parent module with specified data.
 *  @param[in] socket_id Socket identifier.
 *  @param[in] message The action message.
 *  @param[in] arg2 The second message parameter.
 *  @param[in] data The data to be sent.
 *  @param[in] datalength The data length.
 *  @returns EOK on success.
 *  @returns ENOTSOCK if the socket is not found.
 *  @returns EBADMEM if the data parameter is NULL.
 *  @returns NO_DATA if the datalength parameter is zero (0).
 *  @returns Other error codes as defined for the spcific message.
 */
int     socket_send_data( int socket_id, ipcarg_t message, ipcarg_t arg2, const void * data, size_t datalength );

/** Initializes a new socket specific data.
 *  @param[in,out] socket The socket to be initialized.
 *  @param[in] socket_id The new socket identifier.
 *  @param[in] phone The parent module phone.
 *  @param[in] service The parent module service.
 */
void    socket_initialize( socket_ref socket, int socket_id, int phone, services_t service );

/** Clears and destroys the socket.
 *  @param[in] socket The socket to be destroyed.
 */
void    socket_destroy( socket_ref socket );

/** Receives data via the socket.
 *  @param[in] message The action message.
 *  @param[in] socket_id Socket identifier.
 *  @param[out] data The data buffer to be filled.
 *  @param[in] datalength The data length.
 *  @param[in] flags Various receive flags.
 *  @param[out] fromaddr The source address. May be NULL for connected sockets.
 *  @param[in,out] addrlen The address length. The maximum address length is read. The actual address length is set. Used only if fromaddr is not NULL.
 *  @returns EOK on success.
 *  @returns ENOTSOCK if the socket is not found.
 *  @returns EBADMEM if the data parameter is NULL.
 *  @returns NO_DATA if the datalength or addrlen parameter is zero (0).
 *  @returns Other error codes as defined for the spcific message.
 */
int     recvfrom_core( ipcarg_t message, int socket_id, void * data, size_t datalength, int flags, struct sockaddr * fromaddr, socklen_t * addrlen );

/** Sends data via the socket to the remote address.
 *  Binds the socket to a free port if not already connected/bound.
 *  @param[in] message The action message.
 *  @param[in] socket_id Socket identifier.
 *  @param[in] data The data to be sent.
 *  @param[in] datalength The data length.
 *  @param[in] flags Various send flags.
 *  @param[in] toaddr The destination address. May be NULL for connected sockets.
 *  @param[in] addrlen The address length. Used only if toaddr is not NULL.
 *  @returns EOK on success.
 *  @returns ENOTSOCK if the socket is not found.
 *  @returns EBADMEM if the data or toaddr parameter is NULL.
 *  @returns NO_DATA if the datalength or the addrlen parameter is zero (0).
 *  @returns Other error codes as defined for the NET_SOCKET_SENDTO message.
 */
int     sendto_core( ipcarg_t message, int socket_id, const void * data, size_t datalength, int flags, const struct sockaddr * toaddr, socklen_t addrlen );

static int socket_get_tcp_phone( void ){
        if( socket_globals.tcp_phone < 0 ){
                socket_globals.tcp_phone = bind_service_timeout( SERVICE_TCP, 0, 0, SERVICE_TCP, socket_connection, SOCKET_CONNECT_TIMEOUT );
        }
        return socket_globals.tcp_phone;
}

static int socket_get_udp_phone( void ){
        if( socket_globals.udp_phone < 0 ){
                socket_globals.udp_phone = bind_service_timeout( SERVICE_UDP, 0, 0, SERVICE_UDP, socket_connection, SOCKET_CONNECT_TIMEOUT );
        }
        return socket_globals.udp_phone;
}

static sockets_ref socket_get_sockets( void ){
        if( ! socket_globals.sockets ){
                socket_globals.sockets = ( sockets_ref ) malloc( sizeof( sockets_t ));
                if( ! socket_globals.sockets ) return NULL;
                if( sockets_initialize( socket_globals.sockets ) != EOK ){
                        free( socket_globals.sockets );
                        socket_globals.sockets = NULL;
                }
                srand( task_get_id());
        }
        return socket_globals.sockets;
}

static int socket_generate_new_id( void ){
        sockets_ref     sockets;
        int                     socket_id;
        int                     count;

        sockets = socket_get_sockets();
        count = 0;
//      socket_id = socket_globals.last_id;
        do{
                if( count < SOCKET_ID_TRIES ){
                        socket_id = rand() % INT_MAX;
                        ++ count;
                }else if( count == SOCKET_ID_TRIES ){
                        socket_id = 1;
                        ++ count;
                // only this branch for last_id
                }else{
                        if( socket_id < INT_MAX ){
                                ++ socket_id;
/*                      }else if( socket_globals.last_id ){
*                               socket_globals.last_id = 0;
*                               socket_id = 1;
*/                      }else{
                                return ELIMIT;
                        }
                }
        }while( sockets_find( sockets, socket_id ));
//      last_id = socket_id
        return socket_id;
}

void socket_initialize( socket_ref socket, int socket_id, int phone, services_t service ){
        socket->socket_id = socket_id;
        socket->phone = phone;
        socket->service = service;
        dyn_fifo_initialize( & socket->received, SOCKET_INITIAL_RECEIVED_SIZE );
        dyn_fifo_initialize( & socket->accepted, SOCKET_INITIAL_ACCEPTED_SIZE );
        fibril_mutex_initialize( & socket->receive_lock );
        fibril_condvar_initialize( & socket->receive_signal );
        fibril_mutex_initialize( & socket->accept_lock );
        fibril_condvar_initialize( & socket->accept_signal );
        fibril_rwlock_initialize( & socket->sending_lock );
}

void socket_connection( ipc_callid_t iid, ipc_call_t * icall ){
        ERROR_DECLARE;

        ipc_callid_t    callid;
        ipc_call_t              call;
        socket_ref              socket;

        while( true ){

                callid = async_get_call( & call );
                switch( IPC_GET_METHOD( call )){
                        case NET_SOCKET_RECEIVED:
                        case NET_SOCKET_ACCEPTED:
                        case NET_SOCKET_DATA_FRAGMENT_SIZE:
                                fibril_rwlock_read_lock( & socket_globals.lock );
                                // find the socket
                                socket = sockets_find( socket_get_sockets(), SOCKET_GET_SOCKET_ID( call ));
                                if( ! socket ){
                                        ERROR_CODE = ENOTSOCK;
                                }else{
                                        switch( IPC_GET_METHOD( call )){
                                                case NET_SOCKET_RECEIVED:
                                                        fibril_mutex_lock( & socket->receive_lock );
                                                        // push the number of received packet fragments
                                                        if( ! ERROR_OCCURRED( dyn_fifo_push( & socket->received, SOCKET_GET_DATA_FRAGMENTS( call ), SOCKET_MAX_RECEIVED_SIZE ))){
                                                                // signal the received packet
                                                                fibril_condvar_signal( & socket->receive_signal );
                                                        }
                                                        fibril_mutex_unlock( & socket->receive_lock );
                                                        break;
                                                case NET_SOCKET_ACCEPTED:
                                                        // push the new socket identifier
                                                        fibril_mutex_lock( & socket->accept_lock );
                                                        if( ERROR_OCCURRED( dyn_fifo_push( & socket->accepted, SOCKET_GET_NEW_SOCKET_ID( call ), SOCKET_MAX_ACCEPTED_SIZE ))){
                                                                sockets_exclude( socket_get_sockets(), SOCKET_GET_NEW_SOCKET_ID( call ));
                                                        }else{
                                                                // signal the accepted socket
                                                                fibril_condvar_signal( & socket->accept_signal );
                                                        }
                                                        fibril_mutex_unlock( & socket->accept_lock );
                                                        break;
                                                default:
                                                        ERROR_CODE = ENOTSUP;
                                        }
                                        if(( SOCKET_GET_DATA_FRAGMENT_SIZE( call ) > 0 )
                                        && ( SOCKET_GET_DATA_FRAGMENT_SIZE( call ) != socket->data_fragment_size )){
                                                fibril_rwlock_write_lock( & socket->sending_lock );
                                                // set the data fragment size
                                                socket->data_fragment_size = SOCKET_GET_DATA_FRAGMENT_SIZE( call );
                                                fibril_rwlock_write_unlock( & socket->sending_lock );
                                        }
                                }
                                fibril_rwlock_read_unlock( & socket_globals.lock );
                        default:
                                ERROR_CODE = ENOTSUP;
                }
                ipc_answer_0( callid, ( ipcarg_t ) ERROR_CODE );
        }
}

int socket( int domain, int type, int protocol ){
        ERROR_DECLARE;

        socket_ref      socket;
        int                     phone;
        int                     socket_id;
        services_t      service;
        int                     count;

        // find the appropriate service
        switch( domain ){
                case PF_INET:
                        switch( type ){
                                case SOCK_STREAM:
                                        if( ! protocol ) protocol = IPPROTO_TCP;
                                        switch( protocol ){
                                                case IPPROTO_TCP:
                                                        phone = socket_get_tcp_phone();
                                                        service = SERVICE_TCP;
                                                        break;
                                                default:
                                                        return EPROTONOSUPPORT;
                                        }
                                        break;
                                case SOCK_DGRAM:
                                        if( ! protocol ) protocol = IPPROTO_UDP;
                                        switch( protocol ){
                                                case IPPROTO_UDP:
                                                        phone = socket_get_udp_phone();
                                                        service = SERVICE_UDP;
                                                        break;
                                                default:
                                                        return EPROTONOSUPPORT;
                                        }
                                        break;
                                case SOCK_RAW:
                                default:
                                        return ESOCKTNOSUPPORT;
                        }
                        break;
                // TODO IPv6
                default:
                        return EPFNOSUPPORT;
        }
        if( phone < 0 ) return phone;
        // create a new socket structure
        socket = ( socket_ref ) malloc( sizeof( socket_t ));
        if( ! socket ) return ENOMEM;
        bzero( socket, sizeof( * socket ));
        count = 0;
        fibril_rwlock_write_lock( & socket_globals.lock );
        // request a new socket
        socket_id = socket_generate_new_id();
        if( socket_id <= 0 ){
                fibril_rwlock_write_unlock( & socket_globals.lock );
                free( socket );
                return socket_id;
        }
        if( ERROR_OCCURRED(( int ) async_req_3_3( phone, NET_SOCKET, socket_id, 0, service, NULL, ( ipcarg_t * ) & socket->data_fragment_size, ( ipcarg_t * ) & socket->header_size ))){
                fibril_rwlock_write_unlock( & socket_globals.lock );
                free( socket );
                return ERROR_CODE;
        }
        // finish the new socket initialization
        socket_initialize( socket, socket_id, phone, service );
        // store the new socket
        ERROR_CODE = sockets_add( socket_get_sockets(), socket_id, socket );
        fibril_rwlock_write_unlock( & socket_globals.lock );
        if( ERROR_CODE < 0 ){
                dyn_fifo_destroy( & socket->received );
                dyn_fifo_destroy( & socket->accepted );
                free( socket );
                async_msg_3( phone, NET_SOCKET_CLOSE, ( ipcarg_t ) socket_id, 0, service );
                return ERROR_CODE;
        }

        return socket_id;
}

int socket_send_data( int socket_id, ipcarg_t message, ipcarg_t arg2, const void * data, size_t datalength ){
        socket_ref              socket;
        aid_t                   message_id;
        ipcarg_t                result;

        if( ! data ) return EBADMEM;
        if( ! datalength ) return NO_DATA;

        fibril_rwlock_read_lock( & socket_globals.lock );
        // find the socket
        socket = sockets_find( socket_get_sockets(), socket_id );
        if( ! socket ){
                fibril_rwlock_read_unlock( & socket_globals.lock );
                return ENOTSOCK;
        }
        // request the message
        message_id = async_send_3( socket->phone, message, ( ipcarg_t ) socket->socket_id, arg2, socket->service, NULL );
        // send the address
        async_data_write_start( socket->phone, data, datalength );
        fibril_rwlock_read_unlock( & socket_globals.lock );
        async_wait_for( message_id, & result );
        return ( int ) result;
}

int bind( int socket_id, const struct sockaddr * my_addr, socklen_t addrlen ){
        if( addrlen <= 0 ) return EINVAL;
        // send the address
        return socket_send_data( socket_id, NET_SOCKET_BIND, 0, my_addr, ( size_t ) addrlen );
}

int listen( int socket_id, int backlog ){
        socket_ref      socket;
        int                     result;

        if( backlog <= 0 ) return EINVAL;
        fibril_rwlock_read_lock( & socket_globals.lock );
        // find the socket
        socket = sockets_find( socket_get_sockets(), socket_id );
        if( ! socket ){
                fibril_rwlock_read_unlock( & socket_globals.lock );
                return ENOTSOCK;
        }
        // request listen backlog change
        result = ( int ) async_req_3_0( socket->phone, NET_SOCKET_LISTEN, ( ipcarg_t ) socket->socket_id, ( ipcarg_t ) backlog, socket->service );
        fibril_rwlock_read_unlock( & socket_globals.lock );
        return result;
}

int accept( int socket_id, struct sockaddr * cliaddr, socklen_t * addrlen ){
        socket_ref              socket;
        socket_ref              new_socket;
        aid_t                   message_id;
        int                             result;
        ipc_call_t              answer;

        if(( ! cliaddr ) || ( ! addrlen )) return EBADMEM;

        fibril_rwlock_write_lock( & socket_globals.lock );
        // find the socket
        socket = sockets_find( socket_get_sockets(), socket_id );
        if( ! socket ){
                fibril_rwlock_write_unlock( & socket_globals.lock );
                return ENOTSOCK;
        }
        fibril_mutex_lock( & socket->accept_lock );
        // wait for an accepted socket
        ++ socket->blocked;
        while( dyn_fifo_value( & socket->accepted ) <= 0 ){
                fibril_rwlock_write_unlock( & socket_globals.lock );
                fibril_condvar_wait( & socket->accept_signal, & socket->accept_lock );
                fibril_rwlock_write_lock( & socket_globals.lock );
        }
        -- socket->blocked;

        // create a new scoket
        new_socket = ( socket_ref ) malloc( sizeof( socket_t ));
        if( ! new_socket ){
                fibril_mutex_unlock( & socket->accept_lock );
                fibril_rwlock_write_unlock( & socket_globals.lock );
                return ENOMEM;
        }
        bzero( new_socket, sizeof( * new_socket ));
        socket_id = socket_generate_new_id();
        if( socket_id <= 0 ){
                fibril_mutex_unlock( & socket->accept_lock );
                fibril_rwlock_write_unlock( & socket_globals.lock );
                free( new_socket );
                return socket_id;
        }
        socket_initialize( new_socket, socket_id, socket->phone, socket->service );
        result = sockets_add( socket_get_sockets(), new_socket->socket_id, new_socket );
        if( result < 0 ){
                fibril_mutex_unlock( & socket->accept_lock );
                fibril_rwlock_write_unlock( & socket_globals.lock );
                free( new_socket );
                return result;
        }

        // request accept
        message_id = async_send_5( socket->phone, NET_SOCKET_ACCEPT, ( ipcarg_t ) socket->socket_id, 0, socket->service, 0, new_socket->socket_id, & answer );
        // read address
        ipc_data_read_start( socket->phone, cliaddr, * addrlen );
        fibril_rwlock_write_unlock( & socket_globals.lock );
        async_wait_for( message_id, ( ipcarg_t * ) & result );
        if( result > 0 ){
                if( result != socket_id ){
                        result = EINVAL;
                }
                // dequeue the accepted socket if successful
                dyn_fifo_pop( & socket->accepted );
                // set address length
                * addrlen = SOCKET_GET_ADDRESS_LENGTH( answer );
                new_socket->data_fragment_size = SOCKET_GET_DATA_FRAGMENT_SIZE( answer );
        }else if( result == ENOTSOCK ){
                // empty the queue if no accepted sockets
                while( dyn_fifo_pop( & socket->accepted ) > 0 );
        }
        fibril_mutex_unlock( & socket->accept_lock );
        return result;
}

int connect( int socket_id, const struct sockaddr * serv_addr, socklen_t addrlen ){
        if( ! serv_addr ) return EDESTADDRREQ;
        if( ! addrlen ) return EDESTADDRREQ;
        // send the address
        return socket_send_data( socket_id, NET_SOCKET_CONNECT, 0, serv_addr, addrlen );
}

int closesocket( int socket_id ){
        ERROR_DECLARE;

        socket_ref              socket;

        fibril_rwlock_write_lock( & socket_globals.lock );
        socket = sockets_find( socket_get_sockets(), socket_id );
        if( ! socket ){
                fibril_rwlock_write_unlock( & socket_globals.lock );
                return ENOTSOCK;
        }
        if( socket->blocked ){
                fibril_rwlock_write_unlock( & socket_globals.lock );
                return EINPROGRESS;
        }
        // request close
        ERROR_PROPAGATE(( int ) async_req_3_0( socket->phone, NET_SOCKET_CLOSE, ( ipcarg_t ) socket->socket_id, 0, socket->service ));
        // free the socket structure
        socket_destroy( socket );
        fibril_rwlock_write_unlock( & socket_globals.lock );
        return EOK;
}

void socket_destroy( socket_ref socket ){
        int     accepted_id;

        // destroy all accepted sockets
        while(( accepted_id = dyn_fifo_pop( & socket->accepted )) >= 0 ){
                socket_destroy( sockets_find( socket_get_sockets(), accepted_id ));
        }
        dyn_fifo_destroy( & socket->received );
        dyn_fifo_destroy( & socket->accepted );
        sockets_exclude( socket_get_sockets(), socket->socket_id );
}

int send( int socket_id, void * data, size_t datalength, int flags ){
        // without the address
        return sendto_core( NET_SOCKET_SEND, socket_id, data, datalength, flags, NULL, 0 );
}

int sendto( int socket_id, const void * data, size_t datalength, int flags, const struct sockaddr * toaddr, socklen_t addrlen ){
        if( ! toaddr ) return EDESTADDRREQ;
        if( ! addrlen ) return EDESTADDRREQ;
        // with the address
        return sendto_core( NET_SOCKET_SENDTO, socket_id, data, datalength, flags, toaddr, addrlen );
}

int sendto_core( ipcarg_t message, int socket_id, const void * data, size_t datalength, int flags, const struct sockaddr * toaddr, socklen_t addrlen ){
        socket_ref              socket;
        aid_t                   message_id;
        ipcarg_t                result;
        size_t                  fragments;
        ipc_call_t              answer;

        if( ! data ) return EBADMEM;
        if( ! datalength ) return NO_DATA;
        fibril_rwlock_read_lock( & socket_globals.lock );
        // find socket
        socket = sockets_find( socket_get_sockets(), socket_id );
        if( ! socket ){
                fibril_rwlock_read_unlock( & socket_globals.lock );
                return ENOTSOCK;
        }
        fibril_rwlock_read_lock( & socket->sending_lock );
        // compute data fragment count
        if( socket->data_fragment_size > 0 ){
                fragments = ( datalength + socket->header_size ) / socket->data_fragment_size;
                if(( datalength + socket->header_size ) % socket->data_fragment_size ) ++ fragments;
        }else{
                fragments = 1;
        }
        // request send
        message_id = async_send_5( socket->phone, message, ( ipcarg_t ) socket->socket_id, ( fragments == 1 ? datalength : socket->data_fragment_size ), socket->service, ( ipcarg_t ) flags, fragments, & answer );
        // send the address if given
        if(( ! toaddr ) || ( async_data_write_start( socket->phone, toaddr, addrlen ) == EOK )){
                if( fragments == 1 ){
                        // send all if only one fragment
                        async_data_write_start( socket->phone, data, datalength );
                }else{
                        // send the first fragment
                        async_data_write_start( socket->phone, data, socket->data_fragment_size - socket->header_size );
                        data = (( const uint8_t * ) data ) + socket->data_fragment_size - socket->header_size;
                        // send the middle fragments
                        while(( -- fragments ) > 1 ){
                                async_data_write_start( socket->phone, data, socket->data_fragment_size );
                                data = (( const uint8_t * ) data ) + socket->data_fragment_size;
                        }
                        // send the last fragment
                        async_data_write_start( socket->phone, data, ( datalength + socket->header_size ) % socket->data_fragment_size );
                }
        }
        async_wait_for( message_id, & result );
        if(( SOCKET_GET_DATA_FRAGMENT_SIZE( answer ) > 0 )
        && ( SOCKET_GET_DATA_FRAGMENT_SIZE( answer ) != socket->data_fragment_size )){
                // set the data fragment size
                socket->data_fragment_size = SOCKET_GET_DATA_FRAGMENT_SIZE( answer );
        }
        fibril_rwlock_read_unlock( & socket->sending_lock );
        fibril_rwlock_read_unlock( & socket_globals.lock );
        return ( int ) result;
}

int recv( int socket_id, void * data, size_t datalength, int flags ){
        // without the address
        return recvfrom_core( NET_SOCKET_RECV, socket_id, data, datalength, flags, NULL, NULL );
}

int recvfrom( int socket_id, void * data, size_t datalength, int flags, struct sockaddr * fromaddr, socklen_t * addrlen ){
        if( ! fromaddr ) return EBADMEM;
        if( ! addrlen ) return NO_DATA;
        // with the address
        return recvfrom_core( NET_SOCKET_RECVFROM, socket_id, data, datalength, flags, fromaddr, addrlen );
}

int recvfrom_core( ipcarg_t message, int socket_id, void * data, size_t datalength, int flags, struct sockaddr * fromaddr, socklen_t * addrlen ){
        socket_ref              socket;
        aid_t                   message_id;
        int                             result;
        size_t                  fragments;
        size_t *                lengths;
        size_t                  index;
        ipc_call_t              answer;

        if( ! data ) return EBADMEM;
        if( ! datalength ) return NO_DATA;
        if( fromaddr && ( ! addrlen )) return EINVAL;
        fibril_rwlock_read_lock( & socket_globals.lock );
        // find the socket
        socket = sockets_find( socket_get_sockets(), socket_id );
        if( ! socket ){
                fibril_rwlock_read_unlock( & socket_globals.lock );
                return ENOTSOCK;
        }
        fibril_mutex_lock( & socket->receive_lock );
        // wait for a received packet
        ++ socket->blocked;
        while(( result = dyn_fifo_value( & socket->received )) <= 0 ){
                fibril_rwlock_read_unlock( & socket_globals.lock );
                fibril_condvar_wait( & socket->receive_signal, & socket->receive_lock );
                fibril_rwlock_read_lock( & socket_globals.lock );
        }
        -- socket->blocked;
        fragments = ( size_t ) result;
        // prepare lengths if more fragments
        if( fragments > 1 ){
                lengths = ( size_t * ) malloc( sizeof( size_t ) * fragments + sizeof( size_t ));
                if( ! lengths ){
                        fibril_mutex_unlock( & socket->receive_lock );
                        fibril_rwlock_read_unlock( & socket_globals.lock );
                        return ENOMEM;
                }
                // request packet data
                message_id = async_send_4( socket->phone, message, ( ipcarg_t ) socket->socket_id, 0, socket->service, ( ipcarg_t ) flags, & answer );
                // read the address if desired
                if(( ! fromaddr ) || ( async_data_read_start( socket->phone, fromaddr, * addrlen ) == EOK )){
                // read the fragment lengths
                        if( async_data_read_start( socket->phone, lengths, sizeof( int ) * ( fragments + 1 )) == EOK ){
                                if( lengths[ fragments ] <= datalength ){
                                        // read all fragments if long enough
                                        for( index = 0; index < fragments; ++ index ){
                                                async_data_read_start( socket->phone, data, lengths[ index ] );
                                                data = (( uint8_t * ) data ) + lengths[ index ];
                                        }
                                }
                        }
                }
                free( lengths );
        }else{
                // request packet data
                message_id = async_send_4( socket->phone, message, ( ipcarg_t ) socket->socket_id, 0, socket->service, ( ipcarg_t ) flags, & answer );
                // read the address if desired
                if(( ! fromaddr ) || ( async_data_read_start( socket->phone, fromaddr, * addrlen ) == EOK )){
                        // read all if only one fragment
                        async_data_read_start( socket->phone, data, datalength );
                }
        }
        async_wait_for( message_id, ( ipcarg_t * ) & result );
        // if successful
        if( result == EOK ){
                // dequeue the received packet
                dyn_fifo_pop( & socket->received );
                // return read data length
                result = SOCKET_GET_READ_DATA_LENGTH( answer );
                // set address length
                if( fromaddr && addrlen ) * addrlen = SOCKET_GET_ADDRESS_LENGTH( answer );
        }
        fibril_mutex_unlock( & socket->receive_lock );
        fibril_rwlock_read_unlock( & socket_globals.lock );
        return result;
}

int getsockopt( int socket_id, int level, int optname, void * value, size_t * optlen ){
        socket_ref              socket;
        aid_t                   message_id;
        ipcarg_t                result;

        if( !( value && optlen )) return EBADMEM;
        if( !( * optlen )) return NO_DATA;
        fibril_rwlock_read_lock( & socket_globals.lock );
        // find the socket
        socket = sockets_find( socket_get_sockets(), socket_id );
        if( ! socket ){
                fibril_rwlock_read_unlock( & socket_globals.lock );
                return ENOTSOCK;
        }
        // request option value
        message_id = async_send_3( socket->phone, NET_SOCKET_GETSOCKOPT, ( ipcarg_t ) socket->socket_id, ( ipcarg_t ) optname, socket->service, NULL );
        // read the length
        if( async_data_read_start( socket->phone, optlen, sizeof( * optlen )) == EOK ){
                // read the value
                async_data_read_start( socket->phone, value, * optlen );
        }
        fibril_rwlock_read_unlock( & socket_globals.lock );
        async_wait_for( message_id, & result );
        return ( int ) result;
}

int setsockopt( int socket_id, int level, int optname, const void * value, size_t optlen ){
        // send the value
        return socket_send_data( socket_id, NET_SOCKET_SETSOCKOPT, ( ipcarg_t ) optname, value, optlen );

}

/** @}
 */