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    41 

    42 #include "q3socketdevice.h"

    43 #ifndef QT_NO_NETWORK

    44 

    45 #include "qwindowdefs.h"

    46 #include <string.h>

    47 

    48 QT_BEGIN_NAMESPACE

    49 

    50 //#define Q3SOCKETDEVICE_DEBUG

    51 

    52 

    53 class Q3SocketDevicePrivate

    54 {

    55 public:

    56     Q3SocketDevicePrivate( Q3SocketDevice::Protocol p )

    57 	: protocol(p)

    58     { }

    59 

    60     Q3SocketDevice::Protocol protocol;

    61 };

    62 

    63 

    64 /*!

    65     \class Q3SocketDevice

    66     \brief The Q3SocketDevice class provides a platform-independent low-level socket API.

    67 

    68     \compat

    69     \reentrant

    70 

    71     This class provides a low level API for working with sockets.  Users of

    72     this class are assumed to have networking experience. For most users the

    73     Q3Socket class provides a much easier and high level alternative, but

    74     certain things (like UDP) can't be done with Q3Socket and if you need a

    75     platform-independent API for those, Q3SocketDevice is the right choice.

    76 

    77     The essential purpose of the class is to provide a QIODevice that

    78     works on sockets, wrapped in a platform-independent API.

    79 

    80     When calling connect() or bind(), Q3SocketDevice detects the

    81     protocol family (IPv4, IPv6) automatically. Passing the protocol

    82     family to Q3SocketDevice's constructor or to setSocket() forces

    83     creation of a socket device of a specific protocol. If not set, the

    84     protocol will be detected at the first call to connect() or bind().

    85 

    86     \sa Q3Socket, QSocketNotifier, QHostAddress

    87 */

    88 

    89 

    90 /*!

    91     \enum Q3SocketDevice::Protocol

    92 

    93     This enum type describes the protocol family of the socket. Possible values

    94     are:

    95 

    96     \value IPv4 The socket is an IPv4 socket.

    97     \value IPv6 The socket is an IPv6 socket.

    98     \value Unknown The protocol family of the socket is not known. This can

    99 	   happen if you use Q3SocketDevice with an already existing socket; it

   100 	   tries to determine the protocol family, but this can fail if the

   101 	   protocol family is not known to Q3SocketDevice.

   102 

   103     \sa protocol() setSocket()

   104 */

   105 

   106 /*!

   107     \enum Q3SocketDevice::Error

   108 

   109     This enum type describes the error states of Q3SocketDevice.

   110 

   111     \value NoError  No error has occurred.

   112 

   113     \value AlreadyBound  The device is already bound, according to bind().

   114 

   115     \value Inaccessible  The operating system or firewall prohibited

   116 			the action.

   117 

   118     \value NoResources  The operating system ran out of a resource.

   119 

   120     \value InternalError  An internal error occurred in Q3SocketDevice.

   121 

   122     \value Impossible  An attempt was made to do something which makes

   123     no sense. For example:

   124     \snippet doc/src/snippets/code/src_qt3support_network_q3socketdevice.cpp 0

   125     The libc ::close() closes the socket, but Q3SocketDevice is not aware

   126     of this. So when you call writeBlock(), the impossible happens.

   127 

   128     \value NoFiles  The operating system will not let Q3SocketDevice open

   129     another file.

   130 

   131     \value ConnectionRefused  A connection attempt was rejected by the

   132     peer.

   133 

   134     \value NetworkFailure  There is a network failure.

   135 

   136     \value UnknownError  The operating system did something

   137     unexpected.

   138 

   139     \omitvalue Bug

   140 */

   141 

   142 /*!

   143     \enum Q3SocketDevice::Type

   144 

   145     This enum type describes the type of the socket:

   146     \value Stream  a stream socket (TCP, usually)

   147     \value Datagram  a datagram socket (UDP, usually)

   148 */

   149 

   150 

   151 /*!

   152     Creates a Q3SocketDevice object for the existing socket \a socket.

   153 

   154     The \a type argument must match the actual socket type; use \c

   155     Q3SocketDevice::Stream for a reliable, connection-oriented TCP

   156     socket, or Q3SocketDevice::Datagram for an unreliable,

   157     connectionless UDP socket.

   158 */

   159 Q3SocketDevice::Q3SocketDevice( int socket, Type type )

   160     : fd( socket ), t( type ), p( 0 ), pp( 0 ), e( NoError ),

   161       d(new Q3SocketDevicePrivate(Unknown))

   162 {

   163 #if defined(Q3SOCKETDEVICE_DEBUG)

   164     qDebug( "Q3SocketDevice: Created Q3SocketDevice %p (socket %x, type %d)",

   165 	   this, socket, type );

   166 #endif

   167     init();

   168     setSocket( socket, type );

   169 }

   170 

   171 /*!

   172     Creates a Q3SocketDevice object for a stream or datagram socket.

   173 

   174     The \a type argument must be either Q3SocketDevice::Stream for a

   175     reliable, connection-oriented TCP socket, or \c

   176     Q3SocketDevice::Datagram for an unreliable UDP socket.

   177 

   178     The socket is created as an IPv4 socket.

   179 

   180     \sa blocking() protocol()

   181 */

   182 Q3SocketDevice::Q3SocketDevice( Type type )

   183     : fd( -1 ), t( type ), p( 0 ), pp( 0 ), e( NoError ),

   184       d(new Q3SocketDevicePrivate(IPv4))

   185 {

   186 #if defined(Q3SOCKETDEVICE_DEBUG)

   187     qDebug( "Q3SocketDevice: Created Q3SocketDevice object %p, type %d",

   188 	    this, type );

   189 #endif

   190     init();

   191     setSocket( createNewSocket(), type );

   192 }

   193 

   194 /*!

   195     Creates a Q3SocketDevice object for a stream or datagram socket.

   196 

   197     The \a type argument must be either Q3SocketDevice::Stream for a

   198     reliable, connection-oriented TCP socket, or \c

   199     Q3SocketDevice::Datagram for an unreliable UDP socket.

   200 

   201     The \a protocol indicates whether the socket should be of type IPv4

   202     or IPv6. Passing \c Unknown is not meaningful in this context and you

   203     should avoid using (it creates an IPv4 socket, but your code is not easily

   204     readable).

   205 

   206     The argument \a dummy is necessary for compatibility with some

   207     compilers.

   208 

   209     \sa blocking() protocol()

   210 */

   211 Q3SocketDevice::Q3SocketDevice( Type type, Protocol protocol, int )

   212     : fd( -1 ), t( type ), p( 0 ), pp( 0 ), e( NoError ),

   213       d(new Q3SocketDevicePrivate(protocol))

   214 {

   215 #if defined(Q3SOCKETDEVICE_DEBUG)

   216     qDebug( "Q3SocketDevice: Created Q3SocketDevice object %p, type %d",

   217 	    this, type );

   218 #endif

   219     init();

   220     setSocket( createNewSocket(), type );

   221 }

   222 

   223 /*!

   224     Destroys the socket device and closes the socket if it is open.

   225 */

   226 Q3SocketDevice::~Q3SocketDevice()

   227 {

   228     close();

   229     delete d;

   230     d = 0;

   231 #if defined(Q3SOCKETDEVICE_DEBUG)

   232     qDebug( "Q3SocketDevice: Destroyed Q3SocketDevice %p", this );

   233 #endif

   234 }

   235 

   236 

   237 /*!

   238     Returns true if this is a valid socket; otherwise returns false.

   239 

   240     \sa socket()

   241 */

   242 bool Q3SocketDevice::isValid() const

   243 {

   244     return fd != -1;

   245 }

   246 

   247 

   248 /*!

   249     \fn Type Q3SocketDevice::type() const

   250 

   251     Returns the socket type which is either Q3SocketDevice::Stream

   252     or Q3SocketDevice::Datagram.

   253 

   254     \sa socket()

   255 */

   256 Q3SocketDevice::Type Q3SocketDevice::type() const

   257 {

   258     return t;

   259 }

   260 

   261 /*!

   262     Returns the socket's protocol family, which is one of \c Unknown, \c IPv4,

   263     or \c IPv6.

   264 

   265     Q3SocketDevice either creates a socket with a well known protocol family or

   266     it uses an already existing socket. In the first case, this function

   267     returns the protocol family it was constructed with. In the second case, it

   268     tries to determine the protocol family of the socket; if this fails, it

   269     returns \c Unknown.

   270 

   271     \sa Protocol setSocket()

   272 */

   273 Q3SocketDevice::Protocol Q3SocketDevice::protocol() const

   274 {

   275     if ( d->protocol == Unknown )

   276 	d->protocol = getProtocol();

   277     return d->protocol;

   278 }

   279 

   280 /*!

   281     Returns the socket number, or -1 if it is an invalid socket.

   282 

   283     \sa isValid(), type()

   284 */

   285 int Q3SocketDevice::socket() const

   286 {

   287     return fd;

   288 }

   289 

   290 

   291 /*!

   292     Sets the socket device to operate on the existing socket \a

   293     socket.

   294 

   295     The \a type argument must match the actual socket type; use \c

   296     Q3SocketDevice::Stream for a reliable, connection-oriented TCP

   297     socket, or Q3SocketDevice::Datagram for an unreliable,

   298     connectionless UDP socket.

   299 

   300     Any existing socket is closed.

   301 

   302     \sa isValid(), close()

   303 */

   304 void Q3SocketDevice::setSocket( int socket, Type type )

   305 {

   306     if ( fd != -1 )			// close any open socket

   307 	close();

   308 #if defined(Q3SOCKETDEVICE_DEBUG)

   309     qDebug( "Q3SocketDevice::setSocket: socket %x, type %d", socket, type );

   310 #endif

   311     t = type;

   312     fd = socket;

   313     d->protocol = Unknown;

   314     e = NoError;

   315     resetStatus();

   316     open( ReadWrite );

   317     fetchConnectionParameters();

   318 }

   319 

   320 

   321 /*!

   322     Opens the socket using the specified QIODevice file \a mode. This

   323     function is called from the Q3SocketDevice constructors and from

   324     the setSocket() function. You should not call it yourself.

   325 

   326     \sa close()

   327 */

   328 bool Q3SocketDevice::open( OpenMode mode )

   329 {

   330     if ( isOpen() || !isValid() )

   331 	return false;

   332 #if defined(Q3SOCKETDEVICE_DEBUG)

   333     qDebug( "Q3SocketDevice::open: mode %x", mode );

   334 #endif

   335     setOpenMode( (mode & ReadWrite) | Unbuffered );

   336     return true;

   337 }

   338 

   339 /*!

   340     \fn bool Q3SocketDevice::open(int mode)

   341     \overload

   342 */

   343 /*!

   344     The current Q3SocketDevice implementation does not buffer at all,

   345     so this is a no-op. This function always returns true.

   346 */

   347 bool Q3SocketDevice::flush()

   348 {

   349     return true;

   350 }

   351 

   352 

   353 /*!

   354     \reimp

   355 

   356     The size is meaningless for a socket, therefore this function returns 0.

   357 */

   358 QIODevice::Offset Q3SocketDevice::size() const

   359 {

   360     return 0;

   361 }

   362 

   363 

   364 /*!

   365     The read/write index is meaningless for a socket, therefore this

   366     function returns 0.

   367 */

   368 QIODevice::Offset Q3SocketDevice::at() const

   369 {

   370     return 0;

   371 }

   372 

   373 

   374 /*!

   375     The read/write index is meaningless for a socket, therefore this

   376     function does nothing and returns true.

   377 

   378     The \a offset parameter is ignored.

   379 */

   380 bool Q3SocketDevice::at( Offset /* offset */ )

   381 {

   382     return true;

   383 }

   384 

   385 

   386 /*!

   387     \reimp

   388 

   389     Returns true if no data is currently available at the socket;

   390     otherwise returns false.

   391 */

   392 bool Q3SocketDevice::atEnd() const

   393 {

   394     return bytesAvailable() <= 0;

   395 }

   396 

   397 /*!

   398     Returns true if the address of this socket can be used by other

   399     sockets at the same time, and false if this socket claims

   400     exclusive ownership.

   401 

   402     \sa setAddressReusable()

   403 */

   404 bool Q3SocketDevice::addressReusable() const

   405 {

   406     return option( ReuseAddress );

   407 }

   408 

   409 

   410 /*!

   411     Sets the address of this socket to be usable by other sockets too

   412     if \a enable is true, and to be used exclusively by this socket if

   413     \a enable is false.

   414 

   415     When a socket is reusable, other sockets can use the same port

   416     number (and IP address), which is generally useful. Of course

   417     other sockets cannot use the same

   418     (address,port,peer-address,peer-port) 4-tuple as this socket, so

   419     there is no risk of confusing the two TCP connections.

   420 

   421     \sa addressReusable()

   422 */

   423 void Q3SocketDevice::setAddressReusable( bool enable )

   424 {

   425     setOption( ReuseAddress, enable );

   426 }

   427 

   428 

   429 /*!

   430     Returns the size of the operating system receive buffer.

   431 

   432     \sa setReceiveBufferSize()

   433 */

   434 int Q3SocketDevice::receiveBufferSize() const

   435 {

   436     return option( ReceiveBuffer );

   437 }

   438 

   439 

   440 /*!

   441     Sets the size of the operating system receive buffer to \a size.

   442 

   443     The operating system receive buffer size effectively limits two

   444     things: how much data can be in transit at any one moment, and how

   445     much data can be received in one iteration of the main event loop.

   446 

   447     The default is operating system-dependent. A socket that receives

   448     large amounts of data is probably best with a buffer size of

   449     49152.

   450 */

   451 void Q3SocketDevice::setReceiveBufferSize( uint size )

   452 {

   453     setOption( ReceiveBuffer, size );

   454 }

   455 

   456 

   457 /*!

   458     Returns the size of the operating system send buffer.

   459 

   460     \sa setSendBufferSize()

   461 */

   462 int Q3SocketDevice::sendBufferSize() const

   463 {

   464     return option( SendBuffer );

   465 }

   466 

   467 

   468 /*!

   469     Sets the size of the operating system send buffer to \a size.

   470 

   471     The operating system send buffer size effectively limits how much

   472     data can be in transit at any one moment.

   473 

   474     The default is operating system-dependent. A socket that sends

   475     large amounts of data is probably best with a buffer size of

   476     49152.

   477 */

   478 void Q3SocketDevice::setSendBufferSize( uint size )

   479 {

   480     setOption( SendBuffer, size );

   481 }

   482 

   483 

   484 /*!

   485     Returns the port number of this socket device. This may be 0 for a

   486     while, but is set to something sensible as soon as a sensible

   487     value is available.

   488 

   489     Note that Qt always uses native byte order, i.e. 67 is 67 in Qt;

   490     there is no need to call htons().

   491 */

   492 quint16 Q3SocketDevice::port() const

   493 {

   494     return p;

   495 }

   496 

   497 

   498 /*!

   499     Returns the address of this socket device. This may be 0.0.0.0 for

   500     a while, but is set to something sensible as soon as a sensible

   501     value is available.

   502 */

   503 QHostAddress Q3SocketDevice::address() const

   504 {

   505     return a;

   506 }

   507 

   508 

   509 /*!

   510     Returns the first error seen.

   511 */

   512 Q3SocketDevice::Error Q3SocketDevice::error() const

   513 {

   514     return e;

   515 }

   516 

   517 

   518 /*!

   519     Allows subclasses to set the error state to \a err.

   520 */

   521 void Q3SocketDevice::setError( Error err )

   522 {

   523     e = err;

   524 }

   525 

   526 /*! \fn Q3SocketDevice::readBlock(char *data, Q_ULONG maxlen)

   527 

   528     Reads \a maxlen bytes from the socket into \a data and returns the

   529     number of bytes read. Returns -1 if an error occurred. Returning 0

   530     is not an error. For Stream sockets, 0 is returned when the remote

   531     host closes the connection. For Datagram sockets, 0 is a valid

   532     datagram size.

   533 */

   534 

   535 /*! \fn Q3SocketDevice::writeBlock(const char *data, Q_ULONG len)

   536 

   537     Writes \a len bytes to the socket from \a data and returns the

   538     number of bytes written. Returns -1 if an error occurred.

   539 

   540     This is used for Q3SocketDevice::Stream sockets.

   541 */

   542 

   543 /*!

   544     \fn Q_LONG Q3SocketDevice::writeBlock( const char * data, Q_ULONG len,

   545         const QHostAddress & host, Q_UINT16 port )

   546     \overload

   547 

   548     Writes \a len bytes to the socket from \a data and returns the

   549     number of bytes written. Returns -1 if an error occurred.

   550 

   551     This is used for Q3SocketDevice::Datagram sockets. You must

   552     specify the \a host and \a port of the destination of the data.

   553 */

   554 

   555 /*!

   556     \fn bool Q3SocketDevice::isSequential() const

   557     \internal

   558 */

   559 

   560 /*!

   561     \fn qint64 Q3SocketDevice::readData( char *data, qint64 maxlen )

   562 

   563     Reads \a maxlen bytes from the socket into \a data and returns the

   564     number of bytes read. Returns -1 if an error occurred.

   565 */

   566 

   567 /*!

   568     \fn int Q3SocketDevice::createNewSocket()

   569 

   570     Creates a new socket identifier. Returns -1 if there is a failure

   571     to create the new identifier; error() explains why.

   572 

   573     \sa setSocket()

   574 */

   575 

   576 /*!

   577     \fn void Q3SocketDevice::close()

   578     \reimp

   579 

   580     Closes the socket and sets the socket identifier to -1 (invalid).

   581 

   582     (This function ignores errors; if there are any then a file

   583     descriptor leakage might result. As far as we know, the only error

   584     that can arise is EBADF, and that would of course not cause

   585     leakage. There may be OS-specific errors that we haven't come

   586     across, however.)

   587 

   588     \sa open()

   589 */

   590 

   591 /*!

   592     \fn bool Q3SocketDevice::blocking() const

   593 

   594     Returns true if the socket is valid and in blocking mode;

   595     otherwise returns false.

   596 

   597     Note that this function does not set error().

   598 

   599     \warning On Windows, this function always returns true since the

   600     ioctlsocket() function is broken.

   601 

   602     \sa setBlocking(), isValid()

   603 */

   604 

   605 /*!

   606     \fn void Q3SocketDevice::setBlocking( bool enable )

   607 

   608     Makes the socket blocking if \a enable is true or nonblocking if

   609     \a enable is false.

   610 

   611     Sockets are blocking by default, but we recommend using

   612     nonblocking socket operations, especially for GUI programs that

   613     need to be responsive.

   614 

   615     \warning On Windows, this function should be used with care since

   616     whenever you use a QSocketNotifier on Windows, the socket is

   617     immediately made nonblocking.

   618 

   619     \sa blocking(), isValid()

   620 */

   621 

   622 /*!

   623     \fn int Q3SocketDevice::option( Option opt ) const

   624 

   625     Returns the value of the socket option \a opt.

   626 */

   627 

   628 /*!

   629     \fn void Q3SocketDevice::setOption( Option opt, int v )

   630 

   631     Sets the socket option \a opt to \a v.

   632 */

   633 

   634 /*!

   635     \fn bool Q3SocketDevice::connect( const QHostAddress &addr, Q_UINT16 port )

   636 

   637     Connects to the IP address and port specified by \a addr and \a

   638     port. Returns true if it establishes a connection; otherwise returns false.

   639     If it returns false, error() explains why.

   640 

   641     Note that error() commonly returns NoError for non-blocking

   642     sockets; this just means that you can call connect() again in a

   643     little while and it'll probably succeed.

   644 */

   645 

   646 /*!

   647     \fn bool Q3SocketDevice::bind( const QHostAddress &address, Q_UINT16 port )

   648 

   649     Assigns a name to an unnamed socket. The name is the host address

   650     \a address and the port number \a port. If the operation succeeds,

   651     bind() returns true; otherwise it returns false without changing

   652     what port() and address() return.

   653 

   654     bind() is used by servers for setting up incoming connections.

   655     Call bind() before listen().

   656 */

   657 

   658 /*!

   659     \fn bool Q3SocketDevice::listen( int backlog )

   660 

   661     Specifies how many pending connections a server socket can have.

   662     Returns true if the operation was successful; otherwise returns

   663     false. A \a backlog value of 50 is quite common.

   664 

   665     The listen() call only applies to sockets where type() is \c

   666     Stream, i.e. not to \c Datagram sockets. listen() must not be

   667     called before bind() or after accept().

   668 

   669     \sa bind(), accept()

   670 */

   671 

   672 /*!

   673     \fn int Q3SocketDevice::accept()

   674 

   675     Extracts the first connection from the queue of pending

   676     connections for this socket and returns a new socket identifier.

   677     Returns -1 if the operation failed.

   678 

   679     \sa bind(), listen()

   680 */

   681 

   682 /*!

   683     \fn qint64 Q3SocketDevice::bytesAvailable() const

   684 

   685     Returns the number of bytes available for reading, or -1 if an

   686     error occurred.

   687 

   688     \warning On Microsoft Windows, we use the ioctlsocket() function

   689     to determine the number of bytes queued on the socket. According

   690     to Microsoft (KB Q125486), ioctlsocket() sometimes returns an

   691     incorrect number. The only safe way to determine the amount of

   692     data on the socket is to read it using readBlock(). QSocket has

   693     workarounds to deal with this problem.

   694 */

   695 

   696 /*!

   697     \fn Q_LONG Q3SocketDevice::waitForMore( int msecs, bool *timeout ) const

   698 

   699     Wait up to \a msecs milliseconds for more data to be available. If

   700     \a msecs is -1 the call will block indefinitely.

   701 

   702     Returns the number of bytes available for reading, or -1 if an

   703     error occurred.

   704 

   705     If \a timeout is non-null and no error occurred (i.e. it does not

   706     return -1): this function sets *\a timeout to true, if the reason

   707     for returning was that the timeout was reached; otherwise it sets

   708     *\a timeout to false. This is useful to find out if the peer

   709     closed the connection.

   710 

   711     \warning This is a blocking call and should be avoided in event

   712     driven applications.

   713 

   714     \sa bytesAvailable()

   715 */

   716 

   717 /*!

   718     \fn qint64 Q3SocketDevice::writeData( const char *data, qint64 len )

   719 

   720     Writes \a len bytes to the socket from \a data and returns the

   721     number of bytes written. Returns -1 if an error occurred.

   722 

   723     This is used for Q3SocketDevice::Stream sockets.

   724 */

   725 

   726 /*!

   727     \fn void Q3SocketDevice::fetchConnectionParameters()

   728 

   729     Fetches information about both ends of the connection: whatever is

   730     available.

   731 */

   732 

   733 /*!

   734     \fn Q_UINT16 Q3SocketDevice::peerPort() const

   735 

   736     Returns the port number of the port this socket device is

   737     connected to. This may be 0 for a while, but is set to something

   738     sensible as soon as a sensible value is available.

   739 

   740     Note that for Datagram sockets, this is the source port of the

   741     last packet received, and that it is in native byte order.

   742 */

   743 

   744 /*!

   745     \fn QHostAddress Q3SocketDevice::peerAddress() const

   746 

   747     Returns the address of the port this socket device is connected

   748     to. This may be 0.0.0.0 for a while, but is set to something

   749     sensible as soon as a sensible value is available.

   750 

   751     Note that for Datagram sockets, this is the source port of the

   752     last packet received.

   753 */

   754 

   755 QT_END_NAMESPACE

   756 

   757 #endif //QT_NO_NETWORK