src/network/socket/qudpsocket.cpp
changeset 0 1918ee327afb
child 4 3b1da2848fc7
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/network/socket/qudpsocket.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,447 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtNetwork module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//#define QUDPSOCKET_DEBUG
+
+/*! \class QUdpSocket
+
+    \reentrant
+    \brief The QUdpSocket class provides a UDP socket.
+
+    \ingroup network
+    \inmodule QtNetwork
+
+    UDP (User Datagram Protocol) is a lightweight, unreliable,
+    datagram-oriented, connectionless protocol. It can be used when
+    reliability isn't important. QUdpSocket is a subclass of
+    QAbstractSocket that allows you to send and receive UDP
+    datagrams.
+
+    The most common way to use this class is to bind to an address and port
+    using bind(), then call writeDatagram() and readDatagram() to transfer
+    data. If you want to use the standard QIODevice functions read(),
+    readLine(), write(), etc., you must first connect the socket directly to a
+    peer by calling connectToHost().
+
+    The socket emits the bytesWritten() signal every time a datagram
+    is written to the network. If you just want to send datagrams,
+    you don't need to call bind().
+
+    The readyRead() signal is emitted whenever datagrams arrive. In
+    that case, hasPendingDatagrams() returns true. Call
+    pendingDatagramSize() to obtain the size of the first pending
+    datagram, and readDatagram() to read it.
+
+    \note An incoming datagram should be read when you receive the readyRead()
+    signal, otherwise this signal will not be emitted for the next datagram.
+
+    Example:
+
+    \snippet doc/src/snippets/code/src_network_socket_qudpsocket.cpp 0
+
+    With QUdpSocket, you can also establish a virtual connection to a
+    UDP server using connectToHost() and then use read() and write()
+    to exchange datagrams without specifying the receiver for each
+    datagram.
+
+    The \l{network/broadcastsender}{Broadcast Sender} and
+    \l{network/broadcastreceiver}{Broadcast Receiver} examples
+    illustrate how to use QUdpSocket in applications.
+
+    \sa QTcpSocket
+*/
+
+/*! \enum QUdpSocket::BindFlag
+    \since 4.1
+
+    This enum describes the different flags you can pass to modify the
+    behavior of QUdpSocket::bind().
+
+    \note On Symbian OS bind flags behaviour depends on process capabilties.
+    If process has NetworkControl capability, the bind attempt with
+    ReuseAddressHint will always succeed even if the address and port is already
+    bound by another socket with any flags. If process does not have
+    NetworkControl capability, the bind attempt to address and port already
+    bound by another socket will always fail.
+
+    \value ShareAddress Allow other services to bind to the same address
+    and port. This is useful when multiple processes share
+    the load of a single service by listening to the same address and port
+    (e.g., a web server with several pre-forked listeners can greatly
+    improve response time). However, because any service is allowed to
+    rebind, this option is subject to certain security considerations.
+    Note that by combining this option with ReuseAddressHint, you will
+    also allow your service to rebind an existing shared address. On
+    Unix, this is equivalent to the SO_REUSEADDR socket option. On Windows,
+    this option is ignored.
+
+    \value DontShareAddress Bind the address and port exclusively, so that
+    no other services are allowed to rebind. By passing this option to
+    QUdpSocket::bind(), you are guaranteed that on successs, your service
+    is the only one that listens to the address and port. No services are
+    allowed to rebind, even if they pass ReuseAddressHint. This option
+    provides more security than ShareAddress, but on certain operating
+    systems, it requires you to run the server with administrator privileges.
+    On Unix and Mac OS X, not sharing is the default behavior for binding
+    an address and port, so this option is ignored. On Windows, this
+    option uses the SO_EXCLUSIVEADDRUSE socket option.
+
+    \value ReuseAddressHint Provides a hint to QUdpSocket that it should try
+    to rebind the service even if the address and port are already bound by
+    another socket. On Windows, this is equivalent to the SO_REUSEADDR
+    socket option. On Unix, this option is ignored.
+
+    \value DefaultForPlatform The default option for the current platform.
+    On Unix and Mac OS X, this is equivalent to (DontShareAddress
+    + ReuseAddressHint), and on Windows, its equivalent to ShareAddress.
+*/
+
+#include "qhostaddress.h"
+#include "qabstractsocket_p.h"
+#include "qudpsocket.h"
+
+QT_BEGIN_NAMESPACE
+
+#ifndef QT_NO_UDPSOCKET
+
+#define QT_CHECK_BOUND(function, a) do { \
+    if (!isValid()) { \
+        qWarning(function" called on a QUdpSocket when not in QUdpSocket::BoundState"); \
+        return (a); \
+    } } while (0)
+
+class QUdpSocketPrivate : public QAbstractSocketPrivate
+{
+    Q_DECLARE_PUBLIC(QUdpSocket)
+
+    bool doEnsureInitialized(const QHostAddress &bindAddress, quint16 bindPort,
+                             const QHostAddress &remoteAddress);
+public:
+    inline bool ensureInitialized(const QHostAddress &bindAddress, quint16 bindPort)
+    { return doEnsureInitialized(bindAddress, bindPort, QHostAddress()); }
+
+    inline bool ensureInitialized(const QHostAddress &remoteAddress)
+    { return doEnsureInitialized(QHostAddress(), 0, remoteAddress); }
+};
+
+bool QUdpSocketPrivate::doEnsureInitialized(const QHostAddress &bindAddress, quint16 bindPort,
+                                            const QHostAddress &remoteAddress)
+{
+    const QHostAddress *address = &bindAddress;
+    QAbstractSocket::NetworkLayerProtocol proto = address->protocol();
+    if (proto == QUdpSocket::UnknownNetworkLayerProtocol) {
+        address = &remoteAddress;
+        proto = address->protocol();
+    }
+
+#if defined(QT_NO_IPV6)
+    Q_Q(QUdpSocket);
+    if (proto == QUdpSocket::IPv6Protocol) {
+        socketError = QUdpSocket::UnsupportedSocketOperationError;
+        q->setErrorString(QUdpSocket::tr("This platform does not support IPv6"));
+        return false;
+    }
+#endif
+
+    // now check if the socket engine is initialized and to the right type
+    if (!socketEngine || !socketEngine->isValid() || socketEngine->protocol() != proto) {
+        resolveProxy(remoteAddress.toString(), bindPort);
+        if (!initSocketLayer(address->protocol()))
+            return false;
+    }
+
+    return true;
+}
+
+/*!
+    Creates a QUdpSocket object.
+
+    \a parent is passed to the QObject constructor.
+
+    \sa socketType()
+*/
+QUdpSocket::QUdpSocket(QObject *parent)
+    : QAbstractSocket(UdpSocket, *new QUdpSocketPrivate, parent)
+{
+    d_func()->isBuffered = false;
+}
+
+/*!
+    Destroys the socket, closing the connection if necessary.
+
+    \sa close()
+*/
+QUdpSocket::~QUdpSocket()
+{
+}
+
+/*!
+    Binds this socket to the address \a address and the port \a port.
+    When bound, the signal readyRead() is emitted whenever a UDP
+    datagram arrives on the specified address and port. This function
+    is useful to write UDP servers.
+
+    On success, the functions returns true and the socket enters
+    BoundState; otherwise it returns false.
+
+    The socket is bound using the DefaultForPlatform BindMode.
+
+    \sa readDatagram()
+*/
+bool QUdpSocket::bind(const QHostAddress &address, quint16 port)
+{
+    Q_D(QUdpSocket);
+    if (!d->ensureInitialized(address, port))
+        return false;
+
+    bool result = d_func()->socketEngine->bind(address, port);
+    d->cachedSocketDescriptor = d->socketEngine->socketDescriptor();
+
+    if (!result) {
+        d->socketError = d_func()->socketEngine->error();
+        setErrorString(d_func()->socketEngine->errorString());
+        emit error(d_func()->socketError);
+        return false;
+    }
+
+    d->state = BoundState;
+    d->localAddress = d->socketEngine->localAddress();
+    d->localPort = d->socketEngine->localPort();
+
+    emit stateChanged(d_func()->state);
+    d_func()->socketEngine->setReadNotificationEnabled(true);
+    return true;
+}
+
+/*!
+    \since 4.1
+    \overload
+
+    Binds to \a address on port \a port, using the BindMode \a mode.
+*/
+bool QUdpSocket::bind(const QHostAddress &address, quint16 port, BindMode mode)
+{
+    Q_D(QUdpSocket);
+    if (!d->ensureInitialized(address, port))
+        return false;
+
+#ifdef Q_OS_UNIX
+    if ((mode & ShareAddress) || (mode & ReuseAddressHint))
+        d->socketEngine->setOption(QAbstractSocketEngine::AddressReusable, 1);
+    else
+        d->socketEngine->setOption(QAbstractSocketEngine::AddressReusable, 0);
+#endif
+#ifdef Q_OS_WIN
+    if (mode & ReuseAddressHint)
+        d->socketEngine->setOption(QAbstractSocketEngine::AddressReusable, 1);
+    else
+        d->socketEngine->setOption(QAbstractSocketEngine::AddressReusable, 0);
+    if (mode & DontShareAddress)
+        d->socketEngine->setOption(QAbstractSocketEngine::BindExclusively, 1);
+    else
+        d->socketEngine->setOption(QAbstractSocketEngine::BindExclusively, 0);
+#endif
+    bool result = d_func()->socketEngine->bind(address, port);
+    d->cachedSocketDescriptor = d->socketEngine->socketDescriptor();
+
+    if (!result) {
+        d->socketError = d_func()->socketEngine->error();
+        setErrorString(d_func()->socketEngine->errorString());
+        emit error(d_func()->socketError);
+        return false;
+    }
+
+    d->state = BoundState;
+    d->localAddress = d->socketEngine->localAddress();
+    d->localPort = d->socketEngine->localPort();
+
+    emit stateChanged(d_func()->state);
+    d_func()->socketEngine->setReadNotificationEnabled(true);
+    return true;
+}
+
+/*! \overload
+
+    Binds to QHostAddress:Any on port \a port.
+*/
+bool QUdpSocket::bind(quint16 port)
+{
+    return bind(QHostAddress::Any, port);
+}
+
+/*!
+    \since 4.1
+    \overload
+
+    Binds to QHostAddress:Any on port \a port, using the BindMode \a mode.
+*/
+bool QUdpSocket::bind(quint16 port, BindMode mode)
+{
+    return bind(QHostAddress::Any, port, mode);
+}
+
+/*!
+    Returns true if at least one datagram is waiting to be read;
+    otherwise returns false.
+
+    \sa pendingDatagramSize(), readDatagram()
+*/
+bool QUdpSocket::hasPendingDatagrams() const
+{
+    QT_CHECK_BOUND("QUdpSocket::hasPendingDatagrams()", false);
+    return d_func()->socketEngine->hasPendingDatagrams();
+}
+
+/*!
+    Returns the size of the first pending UDP datagram. If there is
+    no datagram available, this function returns -1.
+
+    \sa hasPendingDatagrams(), readDatagram()
+*/
+qint64 QUdpSocket::pendingDatagramSize() const
+{
+    QT_CHECK_BOUND("QUdpSocket::pendingDatagramSize()", -1);
+    return d_func()->socketEngine->pendingDatagramSize();
+}
+
+/*!
+    Sends the datagram at \a data of size \a size to the host
+    address \a address at port \a port. Returns the number of
+    bytes sent on success; otherwise returns -1.
+
+    Datagrams are always written as one block. The maximum size of a
+    datagram is highly platform-dependent, but can be as low as 8192
+    bytes. If the datagram is too large, this function will return -1
+    and error() will return DatagramTooLargeError.
+
+    Sending datagrams larger than 512 bytes is in general disadvised,
+    as even if they are sent successfully, they are likely to be
+    fragmented by the IP layer before arriving at their final
+    destination.
+
+    \warning In S60 5.0 and earlier versions, the writeDatagram return
+    value is not reliable for large datagrams.
+
+    \warning Calling this function on a connected UDP socket may
+    result in an error and no packet being sent. If you are using a
+    connected socket, use write() to send datagrams.
+
+    \sa readDatagram(), write()
+*/
+qint64 QUdpSocket::writeDatagram(const char *data, qint64 size, const QHostAddress &address,
+                                  quint16 port)
+{
+    Q_D(QUdpSocket);
+#if defined QUDPSOCKET_DEBUG
+    qDebug("QUdpSocket::writeDatagram(%p, %llu, \"%s\", %i)", data, size,
+           address.toString().toLatin1().constData(), port);
+#endif
+    if (!d->ensureInitialized(address))
+        return -1;
+
+    qint64 sent = d->socketEngine->writeDatagram(data, size, address, port);
+#ifdef Q_OS_SYMBIAN
+    if( QSysInfo::s60Version() <= QSysInfo::SV_S60_5_0 ) {
+        // This is evil hack, but for some reason native RSocket::SendTo returns 0,
+        // for large datagrams (such as 600 bytes). Based on comments from Open C team
+        // this should happen only in platforms <= S60 5.0.
+        // As an workaround, we just set sent = size
+        if( sent == 0 )
+            sent = size;
+    }
+#endif
+    d->cachedSocketDescriptor = d->socketEngine->socketDescriptor();
+
+    if (sent >= 0) {
+        emit bytesWritten(sent);
+    } else {
+        d->socketError = d->socketEngine->error();
+        setErrorString(d->socketEngine->errorString());
+        emit error(d->socketError);
+    }
+    return sent;
+}
+
+/*!
+    \fn qint64 QUdpSocket::writeDatagram(const QByteArray &datagram,
+                                             const QHostAddress &host, quint16 port)
+    \overload
+
+    Sends the datagram \a datagram to the host address \a host and at
+    port \a port.
+*/
+
+/*!
+    Receives a datagram no larger than \a maxSize bytes and stores
+    it in \a data. The sender's host address and port is stored in
+    *\a address and *\a port (unless the pointers are 0).
+
+    Returns the size of the datagram on success; otherwise returns
+    -1.
+
+    If \a maxSize is too small, the rest of the datagram will be
+    lost. To avoid loss of data, call pendingDatagramSize() to
+    determine the size of the pending datagram before attempting to
+    read it. If \a maxSize is 0, the datagram will be discarded.
+
+    \sa writeDatagram(), hasPendingDatagrams(), pendingDatagramSize()
+*/
+qint64 QUdpSocket::readDatagram(char *data, qint64 maxSize, QHostAddress *address,
+                                    quint16 *port)
+{
+    Q_D(QUdpSocket);
+
+#if defined QUDPSOCKET_DEBUG
+    qDebug("QUdpSocket::readDatagram(%p, %llu, %p, %p)", data, maxSize, address, port);
+#endif
+    QT_CHECK_BOUND("QUdpSocket::readDatagram()", -1);
+    qint64 readBytes = d->socketEngine->readDatagram(data, maxSize, address, port);
+    d_func()->socketEngine->setReadNotificationEnabled(true);
+    if (readBytes < 0) {
+        d->socketError = d->socketEngine->error();
+        setErrorString(d->socketEngine->errorString());
+        emit error(d->socketError);
+    }
+    return readBytes;
+}
+#endif // QT_NO_UDPSOCKET
+
+QT_END_NAMESPACE