KNetwork::KServerSocket Class Reference

A server socket for accepting connections. More...

#include <kserversocket.h>

Inheritance diagram for KNetwork::KServerSocket:


Signals
void	bound (const KResolverEntry &local)
void	closed ()
void	gotError (int code)
void	hostFound ()
void	readyAccept ()
Public Member Functions
virtual KActiveSocketBase *	accept ()
virtual bool	bind (const KResolverEntry &address)
virtual bool	bind ()
virtual bool	bind (const QString &service)
virtual bool	bind (const QString &node, const QString &service)
virtual void	close ()
virtual KSocketAddress	externalAddress () const
	KServerSocket (const QString &node, const QString &service, QObject parent=0L, const char name=0L)
	KServerSocket (const QString &service, QObject parent=0L, const char name=0L)
	KServerSocket (QObject parent=0L, const char name=0L)
virtual bool	listen (int backlog=5)
virtual KSocketAddress	localAddress () const
virtual bool	lookup ()
KResolver &	resolver () const
const KResolverResults &	resolverResults () const
void	setAcceptBuffered (bool enable)
void	setAddress (const QString &node, const QString &service)
void	setAddress (const QString &service)
void	setFamily (int families)
void	setResolutionEnabled (bool enable)
void	setTimeout (int msecs)
	~KServerSocket ()
Protected Member Functions
void	copyError ()
virtual bool	setSocketOptions (int opts)

Detailed Description

A server socket for accepting connections.

This class provides functionality for creating a socket to listen for incoming connections and subsequently accept them.

To use this class, you must first set the parameters for the listening socket's address, then place it in listening mode.

A typical example would look like:

   QString service = "http";
   KServerSocket *ss = new KServerSocket(service);
   connect(ss, SIGNAL(readyAccept()), this, SLOT(slotReadyAccept()));
   connect(ss, SIGNAL(gotError(int)), this, SLOT(slotSocketError(int)));
   ss->listen();

In this case, this class will place the socket into listening mode on the service pointed to by service and will emit the readyAccept signal when a connection is ready for accepting. The called slot is responsible for calling accept.

The location of the services file (where service is looked up) is defined by _PATH_SERVICES in /usr/include/netdb.h. This is usually set to /etc/services. See RFC 1700 for more information on services. You can specify service as a port number directly, rather than as a service name. This is discouraged as it prevents the end user from easily modifying the port number.

For another example of usage, this below code attempts to make a connection on any port within a range:

   KServerSocket *ss = new KServerSocket();
   ss->setFamily(KResolver::InetFamily);
   bool found = false;
   for( unsigned int port = firstport; port <= lastport; ++port) {
     ss->setAddress( QString::number( port ) );
     bool success = ss->listen();
     if( found = ( success && ss->error() == 
                              KSocketBase::NoError ) )
       break;
     ss->close();
   }
   if( !found ) {
     // Couldn't connect to any port.
   } else {
     connect(ss, SIGNAL(readyAccept()), this, SLOT(slotReadyAccept()));
     connect(ss, SIGNAL(gotError(int)), this, SLOT(slotSocketError(int)));
     ss->listen();
   }

The called slot slotReadyAccept() is responsible for calling accept.

It is important to note that accept can return either an object of type KNetwork::KStreamSocket or KNetwork::KBufferedSocket (default). If you want to accept a non-buffered socket, you must first call setAcceptBuffered.

Warning:: If you use KServerSocket in an auxiliary (non-GUI) thread, you need to accept only KNetwork::KStreamSocket objects.

See also:: KNetwork::KStreamSocket, KNetwork::KBufferedSocket

Author:: Thiago Macieira <thiago@kde.org>

Definition at line 107 of file kserversocket.h.

Constructor & Destructor Documentation

KServerSocket::KServerSocket	(	QObject *	parent = `0L`,
		const char *	name = `0L`
	)

Default constructor.

If the binding address isn't changed by setAddress, this socket will bind to all interfaces on this node and the port will be selected by the operating system.

Parameters:

	parent	the parent QObject object
	name	the name of this object

Definition at line 61 of file kserversocket.cpp.

KServerSocket::KServerSocket	(	const QString &	service,
		QObject *	parent = `0L`,
		const char *	name = `0L`
	)

Construct this object specifying the service to listen on.

If the binding address isn't changed by setAddress, this socket will bind to all interfaces and will listen on the port specified by service. This is either a service name (e.g. 'www') or a port number (e.g. '80').

The location of the services file (where service is looked up) is defined by _PATH_SERVICES in /usr/include/netdb.h. This is usually set to /etc/services. See RFC 1700 for more information on services.

Parameters:

	service	the service name to listen on
	parent	the parent QObject object
	name	the name of this object

Definition at line 68 of file kserversocket.cpp.

KServerSocket::KServerSocket	(	const QString &	node,
		const QString &	service,
		QObject *	parent = `0L`,
		const char *	name = `0L`
	)

Construct this object specifying the node and service names to listen on.

If the binding address isn't changed by setAddress, this socket will bind to the interface specified by node and the port specified by service. This is either a service name (e.g. 'www') or a port number (e.g. '80').

The location of the services file (where service is looked up) is defined by _PATH_SERVICES in /usr/include/netdb.h. This is usually set to /etc/services. See RFC 1700 for more information on services.

Parameters:

	node	the node to bind to
	service	the service port to listen on
	parent	the parent QObject object
	name	the name of this object

Definition at line 76 of file kserversocket.cpp.

KServerSocket::~KServerSocket ( )

Destructor.

This will close the socket, if open.

Note, however, that accepted sockets do not get closed when this object closes.

Definition at line 85 of file kserversocket.cpp.

Member Function Documentation

KActiveSocketBase * KServerSocket::accept ( ) [virtual]

Accepts one incoming connection and return the associated, open socket.

If this function cannot accept a new connection, it will return NULL. The specific object class returned by this function may vary according to the implementation: derived classes may return specialised objects descended from KStreamSocket.

Note:: This function should return a KStreamSocket object, but compiler deficiencies prevent such an adjustment. Therefore, we return the base class for active sockets, but it is guaranteed that the object will be a KStreamSocket or derived from it.

See also:: KBufferedSocket
setAcceptBuffered

Implements KNetwork::KPassiveSocketBase.

Definition at line 283 of file kserversocket.cpp.

bool KServerSocket::bind ( const KResolverEntry & address ) [virtual]

Connect this socket to this specific address.

Reimplemented from KSocketBase.

Unlike bind(const QString&, const QString&) above, this function really does bind the socket. No lookup is performed. The bound signal will be emitted.

Implements KNetwork::KPassiveSocketBase.

Definition at line 182 of file kserversocket.cpp.

bool KServerSocket::bind ( ) [virtual]

Binds the socket to the addresses previously set with setAddress.

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 208 of file kserversocket.cpp.

bool KServerSocket::bind ( const QString & service ) [virtual]

Binds the socket to the given service name.

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters:

service

the service

Definition at line 202 of file kserversocket.cpp.

bool KServerSocket::bind	(	const QString &	node,
		const QString &	service
	)			`[virtual]`

Binds this socket to the given nodename and service, or use the default ones if none are given.

Upon successful binding, the bound signal will be emitted. If an error is found, the gotError signal will be emitted.

This function returns true on success.

Parameters:

	node	the nodename
	service	the service

Definition at line 196 of file kserversocket.cpp.

void KNetwork::KServerSocket::bound ( const KResolverEntry & local ) [signal]

This signal is emitted when the socket successfully binds to an address.

Parameters:

local

the local address we bound to

void KServerSocket::close ( ) [virtual]

Closes this socket.

Implements KNetwork::KPassiveSocketBase.

Definition at line 269 of file kserversocket.cpp.

void KNetwork::KServerSocket::closed ( ) [signal]

This signal is emitted when the socket completes the closing/shut down process.

void KServerSocket::copyError ( ) [protected]

Convenience function to set this object's error code to match that of the socket device.

Definition at line 370 of file kserversocket.cpp.

KSocketAddress KServerSocket::externalAddress ( ) const [virtual]

Returns this socket's externally-visible address if know.

Implements KNetwork::KPassiveSocketBase.

Definition at line 342 of file kserversocket.cpp.

void KNetwork::KServerSocket::gotError ( int code ) [signal]

This signal is emitted when this object finds an error.

The code parameter contains the error code that can also be found by calling error.

void KNetwork::KServerSocket::hostFound ( ) [signal]

This signal is emitted when the lookup is successfully completed.

bool KServerSocket::listen ( int backlog = 5 ) [virtual]

Puts this socket into listening mode.

Reimplemented from KPassiveSocketBase.

Placing a socket into listening mode means it will be able to receive incoming connections through the accept method.

If you do not call this method but call accept directly, the socket will be placed into listening mode automatically.

Parameters:

backlog

the number of connection the system is to queue without accept being called

Returns:: true if the socket is now in listening mode.

Implements KNetwork::KPassiveSocketBase.

Definition at line 232 of file kserversocket.cpp.

KSocketAddress KServerSocket::localAddress ( ) const [virtual]

Returns this socket's local address.

Implements KNetwork::KPassiveSocketBase.

Definition at line 337 of file kserversocket.cpp.

bool KServerSocket::lookup ( ) [virtual]

Starts the lookup for peer and local hostnames as well as their services.

If the blocking mode for this object is on, this function will wait for the lookup results to be available (by calling the KResolver::wait method on the resolver objects).

When the lookup is done, the signal hostFound will be emitted (only once, even if we're doing a double lookup). If the lookup failed (for any of the two lookups) the gotError signal will be emitted with the appropriate error condition (see KSocketBase::SocketError).

This function returns true on success and false on error. Note that this is not the lookup result!

Definition at line 146 of file kserversocket.cpp.

void KNetwork::KServerSocket::readyAccept ( ) [signal]

This signal is emitted whenever the socket is ready for accepting -- i.e., there is at least one connection waiting to be accepted.

KResolver & KServerSocket::resolver ( ) const

Returns the internal KResolver object used for looking up the host name and service.

This can be used to set extra options to the lookup process other than the default values, as well as obtaining the error codes in case of lookup failure.

Definition at line 100 of file kserversocket.cpp.

const KResolverResults & KServerSocket::resolverResults ( ) const

Returns the internal list of resolved results for the binding address.

Definition at line 105 of file kserversocket.cpp.

void KServerSocket::setAcceptBuffered ( bool enable )

Toggles whether the accepted socket will be buffered or not.

That is, the accept function will always return a KStreamSocket object or descended from it. If buffering is enabled, the class to be returned will be KBufferedSocket.

By default, this flag is set to true.

Parameters:

enable

whether to set the accepted socket to buffered mode

Definition at line 278 of file kserversocket.cpp.

void KServerSocket::setAddress	(	const QString &	node,
		const QString &	service
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Sets the address on which we will listen.

This will cause the socket to listen only on the interface given by node and on the port given by service. service can either be a service name (e.g. 'www') or a port number (e.g. '80').

The location of the services file (where service is looked up) is defined by _PATH_SERVICES in /usr/include/netdb.h. This is usually set to /etc/services. See RFC 1700 for more information on services.

Parameters:

	node	the node to bind to
	service	the service port to listen on

Definition at line 132 of file kserversocket.cpp.

void KServerSocket::setAddress ( const QString & service )

Sets the address on which we will listen.

The port to listen on is given by service, and we will bind to all interfaces. To let the operating system choose a port, set the service to "0". service can either be a service name (e.g. 'www') or a port number (e.g. '80').

The location of the services file (where service is looked up) is defined by _PATH_SERVICES in /usr/include/netdb.h. This is usually set to /etc/services. See RFC 1700 for more information on services.

Parameters:

service

the service name to listen on

Definition at line 123 of file kserversocket.cpp.

void KServerSocket::setFamily ( int families )

Sets the allowed families for the resolutions.

Parameters:

families

the families that we want/accept

See also:: KResolver::SocketFamilies for possible values

Definition at line 118 of file kserversocket.cpp.

void KServerSocket::setResolutionEnabled ( bool enable )

Enables or disables name resolution.

If this flag is set to true, the bind operation will trigger name lookup operations (i.e., converting a hostname into its binary form). If the flag is set to false, those operations will instead try to convert a string representation of an address without attempting name resolution.

This is useful, for instance, when IP addresses are in their string representation (such as "1.2.3.4") or come from other sources like KSocketAddress.

Parameters:

enable

whether to enable

Definition at line 110 of file kserversocket.cpp.

bool KServerSocket::setSocketOptions ( int opts ) [protected, virtual]

Sets the socket options.

Reimplemented from KSocketBase.

Reimplemented from KNetwork::KSocketBase.

Definition at line 91 of file kserversocket.cpp.

void KServerSocket::setTimeout ( int msecs )

Sets the timeout for accepting.

When you call accept, it will wait at most msecs milliseconds or return with an error (returning a NULL object).

Parameters:

msecs

the time in milliseconds to wait, 0 to wait forever

Definition at line 141 of file kserversocket.cpp.

The documentation for this class was generated from the following files:

KDECore

KNetwork::KServerSocket Class Reference

Signals

Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

KDECore

API Reference