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/*

 * 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_sync.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

/** 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;

	/** 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,

	.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.

 */

static int	socket_get_tcp_phone( void );

/** Returns the UDP module phone.

 *  Connects to the UDP module if necessary.

 *  @returns The UDP module phone.

 */

static int	socket_get_udp_phone( void );

/** Returns the active sockets.

 *  @returns The active sockets.

 */

static sockets_ref	socket_get_sockets( 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( SERVICE_TCP, 0, 0, SERVICE_TCP, socket_connection );

	}

	return socket_globals.tcp_phone;

}

static int socket_get_udp_phone( void ){

	if( socket_globals.udp_phone < 0 ){

		socket_globals.udp_phone = bind_service( SERVICE_UDP, 0, 0, SERVICE_UDP, socket_connection );

	}

	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;

		}

	}

	return socket_globals.sockets;

}

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;

	socket_ref		new_socket;

	while( true ){

		callid = async_get_call( & call );

		switch( IPC_GET_METHOD( call )){

			case NET_SOCKET_RECEIVED:

				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{

					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 );

				}

				fibril_rwlock_read_unlock( & socket_globals.lock );

				break;

			case NET_SOCKET_ACCEPTED:

				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{

					// create a new scoket

					new_socket = ( socket_ref ) malloc( sizeof( socket_t ));

					if( ! new_socket ){

						ERROR_CODE = ENOMEM;

					}else{

						bzero( new_socket, sizeof( * new_socket ));

						socket_initialize( new_socket, SOCKET_GET_NEW_SOCKET_ID( call ), socket->phone, socket->service );

						ERROR_CODE = sockets_add( socket_get_sockets(), new_socket->socket_id, new_socket );

						if( ERROR_CODE < 0 ){

							free( new_socket );

						}else{

							// push the new socket identifier

							fibril_mutex_lock( & socket->accept_lock );

							if( ERROR_OCCURRED( dyn_fifo_push( & socket->accepted, new_socket->socket_id, SOCKET_MAX_ACCEPTED_SIZE ))){

								sockets_exclude( socket_get_sockets(), new_socket->socket_id );

							}else{

								// signal the accepted socket

								fibril_condvar_signal( & socket->accept_signal );

							}

							fibril_mutex_unlock( & socket->accept_lock );

							ERROR_CODE = EOK;

						}

					}

				}

				fibril_rwlock_read_unlock( & socket_globals.lock );

				break;

			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{

					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 );

					ERROR_CODE = EOK;

				}

				fibril_rwlock_read_unlock( & socket_globals.lock );

				break;

			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;

	// 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;

	}

	// create a new socket structure

	socket = ( socket_ref ) malloc( sizeof( socket_t ));

	if( ! socket ) return ENOMEM;

	bzero( socket, sizeof( * socket ));

	// request a new socket

	if( ERROR_OCCURRED(( int ) async_req_3_3( phone, NET_SOCKET, 0, 0, service, ( ipcarg_t * ) & socket_id, ( ipcarg_t * ) & socket->data_fragment_size, ( ipcarg_t * ) & socket->header_size ))){

		free( socket );

		return ERROR_CODE;

	}

	// finish the new socket initialization

	socket_initialize( socket, socket_id, phone, service );

	// store the new socket

	fibril_rwlock_write_lock( & socket_globals.lock );

	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

	ipc_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;

	aid_t			message_id;

	int				result;

	ipc_call_t		answer;

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

	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->accept_lock );

	// wait for an accepted socket

	++ socket->blocked;

	while( dyn_fifo_value( & socket->accepted ) <= 0 ){

		fibril_rwlock_read_unlock( & socket_globals.lock );

		fibril_condvar_wait( & socket->accept_signal, & socket->accept_lock );

		fibril_rwlock_read_lock( & socket_globals.lock );

	}

	-- socket->blocked;

	// request accept

	message_id = async_send_3( socket->phone, NET_SOCKET_ACCEPT, ( ipcarg_t ) socket->socket_id, 0, socket->service, & answer );

	// read address

	ipc_data_read_start( socket->phone, cliaddr, * addrlen );

	fibril_rwlock_read_unlock( & socket_globals.lock );

	async_wait_for( message_id, ( ipcarg_t * ) & result );

	if( result > 0 ){

		// dequeue the accepted socket if successful

		dyn_fifo_pop( & socket->accepted );

		// set address length

		* addrlen = SOCKET_GET_ADDRESS_LENGTH( 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;

	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

	fragments = ( datalength + socket->header_size ) / socket->data_fragment_size;

	if(( datalength + socket->header_size ) % socket->data_fragment_size ) ++ fragments;

	// request send

	message_id = async_send_5( socket->phone, message, ( ipcarg_t ) socket->socket_id, socket->data_fragment_size, socket->service, ( ipcarg_t ) flags, fragments, NULL );

	// send the address if given

	if(( ! toaddr ) || ( ipc_data_write_start( socket->phone, toaddr, addrlen ) == EOK )){

		if( fragments == 1 ){

			// send all if only one fragment

			ipc_data_write_start( socket->phone, data, datalength );

		}else{

			// send the first fragment

			ipc_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 ){

				ipc_data_write_start( socket->phone, data, socket->data_fragment_size );

				data = (( const uint8_t * ) data ) + socket->data_fragment_size;

			}

			// send the last fragment

			ipc_data_write_start( socket->phone, data, ( datalength + socket->header_size ) % socket->data_fragment_size );

		}

	}

	fibril_rwlock_read_unlock( & socket->sending_lock );

	fibril_rwlock_read_unlock( & socket_globals.lock );

	async_wait_for( message_id, & result );

	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 ) || ( ipc_data_read_start( socket->phone, fromaddr, * addrlen ) == EOK )){

		// read the fragment lengths

			if( ipc_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 ){

						ipc_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 ) || ( ipc_data_read_start( socket->phone, fromaddr, * addrlen ) == EOK )){

			// read all if only one fragment

			ipc_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( ipc_data_read_start( socket->phone, optlen, sizeof( * optlen )) == EOK ){

		// read the value

		ipc_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 );

}

/** @}

 */