qnativesocketengine.cpp

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//#define QNATIVESOCKETENGINE_DEBUG

#include <qabstracteventdispatcher.h>
#include <qsocketnotifier.h>
#include <qnetworkinterface.h>

#include "qnativesocketengine_p.h"
#include <private/qthread_p.h>
#include <private/qobject_p.h>

#if !defined(QT_NO_NETWORKPROXY)
# include "qnetworkproxy.h"
# include "qabstractsocket.h"
# include "qtcpserver.h"
#endif

QT_BEGIN_NAMESPACE

//#define QNATIVESOCKETENGINE_DEBUG

#define Q_VOID

// Common constructs
#define Q_CHECK_VALID_SOCKETLAYER(function, returnValue) do { \
    if (!isValid()) { \
        qWarning(""#function" was called on an uninitialized socket device"); \
        return returnValue; \
    } } while (0)
#define Q_CHECK_INVALID_SOCKETLAYER(function, returnValue) do { \
    if (isValid()) { \
        qWarning(""#function" was called on an already initialized socket device"); \
        return returnValue; \
    } } while (0)
#define Q_CHECK_STATE(function, checkState, returnValue) do { \
    if (d->socketState != (checkState)) { \
        qWarning(""#function" was not called in "#checkState); \
        return (returnValue); \
    } } while (0)
#define Q_CHECK_NOT_STATE(function, checkState, returnValue) do { \
    if (d->socketState == (checkState)) { \
        qWarning(""#function" was called in "#checkState); \
        return (returnValue); \
    } } while (0)
#define Q_CHECK_STATES(function, state1, state2, returnValue) do { \
    if (d->socketState != (state1) && d->socketState != (state2)) { \
        qWarning(""#function" was called" \
                 " not in "#state1" or "#state2); \
        return (returnValue); \
    } } while (0)
#define Q_CHECK_TYPE(function, type, returnValue) do { \
    if (d->socketType != (type)) { \
        qWarning(#function" was called by a" \
                 " socket other than "#type""); \
        return (returnValue); \
    } } while (0)
#define Q_TR(a) QT_TRANSLATE_NOOP(QNativeSocketEngine, a)

QNativeSocketEnginePrivate::QNativeSocketEnginePrivate() :
    socketDescriptor(-1),
    readNotifier(0),
    writeNotifier(0),
    exceptNotifier(0)
{
}

QNativeSocketEnginePrivate::~QNativeSocketEnginePrivate()
{
}

void QNativeSocketEnginePrivate::setError(QAbstractSocket::SocketError error, ErrorString errorString) const
{
    if (hasSetSocketError) {
        // Only set socket errors once for one engine; expect the
        // socket to recreate its engine after an error. Note: There's
        // one exception: SocketError(11) bypasses this as it's purely
        // a temporary internal error condition.
        // Another exception is the way the waitFor*() functions set
        // an error when a timeout occurs. After the call to setError()
        // they reset the hasSetSocketError to false
        return;
    }
    if (error != QAbstractSocket::SocketError(11))
        hasSetSocketError = true;

    socketError = error;

    switch (errorString) {
    case NonBlockingInitFailedErrorString:
        socketErrorString = QNativeSocketEngine::tr("Unable to initialize non-blocking socket");
        break;
    case BroadcastingInitFailedErrorString:
        socketErrorString = QNativeSocketEngine::tr("Unable to initialize broadcast socket");
        break;
    case NoIpV6ErrorString:
        socketErrorString = QNativeSocketEngine::tr("Attempt to use IPv6 socket on a platform with no IPv6 support");
        break;
    case RemoteHostClosedErrorString:
        socketErrorString = QNativeSocketEngine::tr("The remote host closed the connection");
        break;
    case TimeOutErrorString:
        socketErrorString = QNativeSocketEngine::tr("Network operation timed out");
        break;
    case ResourceErrorString:
        socketErrorString = QNativeSocketEngine::tr("Out of resources");
        break;
    case OperationUnsupportedErrorString:
        socketErrorString = QNativeSocketEngine::tr("Unsupported socket operation");
        break;
    case ProtocolUnsupportedErrorString:
        socketErrorString = QNativeSocketEngine::tr("Protocol type not supported");
        break;
    case InvalidSocketErrorString:
        socketErrorString = QNativeSocketEngine::tr("Invalid socket descriptor");
        break;
    case HostUnreachableErrorString:
        socketErrorString = QNativeSocketEngine::tr("Host unreachable");
        break;
    case NetworkUnreachableErrorString:
        socketErrorString = QNativeSocketEngine::tr("Network unreachable");
        break;
    case AccessErrorString:
        socketErrorString = QNativeSocketEngine::tr("Permission denied");
        break;
    case ConnectionTimeOutErrorString:
        socketErrorString = QNativeSocketEngine::tr("Connection timed out");
        break;
    case ConnectionRefusedErrorString:
        socketErrorString = QNativeSocketEngine::tr("Connection refused");
        break;
    case AddressInuseErrorString:
        socketErrorString = QNativeSocketEngine::tr("The bound address is already in use");
        break;
    case AddressNotAvailableErrorString:
        socketErrorString = QNativeSocketEngine::tr("The address is not available");
        break;
    case AddressProtectedErrorString:
        socketErrorString = QNativeSocketEngine::tr("The address is protected");
        break;
    case DatagramTooLargeErrorString:
        socketErrorString = QNativeSocketEngine::tr("Datagram was too large to send");
        break;
    case SendDatagramErrorString:
        socketErrorString = QNativeSocketEngine::tr("Unable to send a message");
        break;
    case ReceiveDatagramErrorString:
        socketErrorString = QNativeSocketEngine::tr("Unable to receive a message");
        break;
    case WriteErrorString:
        socketErrorString = QNativeSocketEngine::tr("Unable to write");
        break;
    case ReadErrorString:
        socketErrorString = QNativeSocketEngine::tr("Network error");
        break;
    case PortInuseErrorString:
        socketErrorString = QNativeSocketEngine::tr("Another socket is already listening on the same port");
        break;
    case NotSocketErrorString:
        socketErrorString = QNativeSocketEngine::tr("Operation on non-socket");
        break;
    case InvalidProxyTypeString:
        socketErrorString = QNativeSocketEngine::tr("The proxy type is invalid for this operation");
        break;
    case UnknownSocketErrorString:
        socketErrorString = QNativeSocketEngine::tr("Unknown error");
        break;
    }
}

bool QNativeSocketEnginePrivate::checkProxy(const QHostAddress &address)
{
    if (address == QHostAddress::LocalHost || address == QHostAddress::LocalHostIPv6)
        return true;

#if !defined(QT_NO_NETWORKPROXY)
    QObject *parent = q_func()->parent();
    QNetworkProxy proxy;
    if (QAbstractSocket *socket = qobject_cast<QAbstractSocket *>(parent)) {
        proxy = socket->proxy();
    } else if (QTcpServer *server = qobject_cast<QTcpServer *>(parent)) {
        proxy = server->proxy();
    } else {
        // no parent -> no proxy
        return true;
    }

    if (proxy.type() == QNetworkProxy::DefaultProxy)
        proxy = QNetworkProxy::applicationProxy();

    if (proxy.type() != QNetworkProxy::DefaultProxy &&
        proxy.type() != QNetworkProxy::NoProxy) {
        // QNativeSocketEngine doesn't do proxies
        setError(QAbstractSocket::UnsupportedSocketOperationError,
                 QNativeSocketEnginePrivate::InvalidProxyTypeString);
        return false;
    }
#endif

    return true;
}

QNativeSocketEngine::QNativeSocketEngine(QObject *parent)
    : QAbstractSocketEngine(*new QNativeSocketEnginePrivate(), parent)
{
}

QNativeSocketEngine::~QNativeSocketEngine()
{
    close();
}

bool QNativeSocketEngine::initialize(QAbstractSocket::SocketType socketType, QAbstractSocket::NetworkLayerProtocol protocol)
{
    Q_D(QNativeSocketEngine);
    if (isValid())
        close();

#if defined(QT_NO_IPV6)
    if (protocol == QAbstractSocket::IPv6Protocol) {
        d->setError(QAbstractSocket::UnsupportedSocketOperationError,
                    QNativeSocketEnginePrivate::NoIpV6ErrorString);
        return false;
    }
#endif

    // Create the socket
    if (!d->createNewSocket(socketType, protocol)) {
#if defined (QNATIVESOCKETENGINE_DEBUG)
        QString typeStr = QLatin1String("UnknownSocketType");
        if (socketType == QAbstractSocket::TcpSocket) typeStr = QLatin1String("TcpSocket");
        else if (socketType == QAbstractSocket::UdpSocket) typeStr = QLatin1String("UdpSocket");
        QString protocolStr = QLatin1String("UnknownProtocol");
        if (protocol == QAbstractSocket::IPv4Protocol) protocolStr = QLatin1String("IPv4Protocol");
        else if (protocol == QAbstractSocket::IPv6Protocol) protocolStr = QLatin1String("IPv6Protocol");
        qDebug("QNativeSocketEngine::initialize(type == %s, protocol == %s) failed: %s",
               typeStr.toLatin1().constData(), protocolStr.toLatin1().constData(), d->socketErrorString.toLatin1().constData());
#endif
        return false;
    }

    // Make the socket nonblocking.
    if (!setOption(NonBlockingSocketOption, 1)) {
        d->setError(QAbstractSocket::UnsupportedSocketOperationError,
                    QNativeSocketEnginePrivate::NonBlockingInitFailedErrorString);
        close();
        return false;
    }

    // Set the broadcasting flag if it's a UDP socket.
    if (socketType == QAbstractSocket::UdpSocket
        && !setOption(BroadcastSocketOption, 1)) {
        d->setError(QAbstractSocket::UnsupportedSocketOperationError,
                    QNativeSocketEnginePrivate::BroadcastingInitFailedErrorString);
        close();
        return false;
    }


    // Make sure we receive out-of-band data
    if (socketType == QAbstractSocket::TcpSocket
        && !setOption(ReceiveOutOfBandData, 1)) {
        qWarning("QNativeSocketEngine::initialize unable to inline out-of-band data");
    }

    // Before Qt 4.6, we always set the send and receive buffer size to 49152 as
    // this was found to be an optimal value. However, modern OS
    // all have some kind of auto tuning for this and we therefore don't set
    // this explictly anymore.
    // If it introduces any performance regressions for Qt 4.6.x (x > 0) then
    // it will be put back in.
    //
    // You can use tests/manual/qhttpnetworkconnection to test HTTP download speed
    // with this.
    //
    // pre-4.6:
    // setReceiveBufferSize(49152);
    // setSendBufferSize(49152);

    d->socketType = socketType;
    d->socketProtocol = protocol;
    return true;
}

bool QNativeSocketEngine::initialize(int socketDescriptor, QAbstractSocket::SocketState socketState)
{
    Q_D(QNativeSocketEngine);

    if (isValid())
        close();

    d->socketDescriptor = socketDescriptor;

    // determine socket type and protocol
    if (!d->fetchConnectionParameters()) {
#if defined (QNATIVESOCKETENGINE_DEBUG)
        qDebug("QNativeSocketEngine::initialize(socketDescriptor == %i) failed: %s",
               socketDescriptor, d->socketErrorString.toLatin1().constData());
#endif
        d->socketDescriptor = -1;
        return false;
    }

    if (d->socketType != QAbstractSocket::UnknownSocketType) {
        // Make the socket nonblocking.
        if (!setOption(NonBlockingSocketOption, 1)) {
            d->setError(QAbstractSocket::UnsupportedSocketOperationError,
                QNativeSocketEnginePrivate::NonBlockingInitFailedErrorString);
            close();
            return false;
        }

        // Set the broadcasting flag if it's a UDP socket.
        if (d->socketType == QAbstractSocket::UdpSocket
            && !setOption(BroadcastSocketOption, 1)) {
            d->setError(QAbstractSocket::UnsupportedSocketOperationError,
                QNativeSocketEnginePrivate::BroadcastingInitFailedErrorString);
            close();
            return false;
        }
    }

    d->socketState = socketState;
    return true;
}

bool QNativeSocketEngine::isValid() const
{
    Q_D(const QNativeSocketEngine);
    return d->socketDescriptor != -1;
}

int QNativeSocketEngine::socketDescriptor() const
{
    Q_D(const QNativeSocketEngine);
    return d->socketDescriptor;
}

bool QNativeSocketEngine::connectToHost(const QHostAddress &address, quint16 port)
{
    Q_D(QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::connectToHost(), false);

#if defined (QT_NO_IPV6)
    if (address.protocol() == QAbstractSocket::IPv6Protocol) {
        d->setError(QAbstractSocket::UnsupportedSocketOperationError,
                    QNativeSocketEnginePrivate::NoIpV6ErrorString);
        return false;
    }
#endif
    if (!d->checkProxy(address))
        return false;

    Q_CHECK_STATES(QNativeSocketEngine::connectToHost(),
                   QAbstractSocket::UnconnectedState, QAbstractSocket::ConnectingState, false);

    d->peerAddress = address;
    d->peerPort = port;
    bool connected = d->nativeConnect(address, port);
    if (connected)
        d->fetchConnectionParameters();

    return connected;
}

void QNativeSocketEngine::connectionNotification()
{
    Q_D(QNativeSocketEngine);
    Q_ASSERT(state() == QAbstractSocket::ConnectingState);

    connectToHost(d->peerAddress, d->peerPort);
    if (state() != QAbstractSocket::ConnectingState) {
        // we changed states
        QAbstractSocketEngine::connectionNotification();
    }
}

bool QNativeSocketEngine::connectToHostByName(const QString &name, quint16 port)
{
    Q_UNUSED(name);
    Q_UNUSED(port);
    Q_D(QNativeSocketEngine);
    d->setError(QAbstractSocket::UnsupportedSocketOperationError,
                QNativeSocketEnginePrivate::OperationUnsupportedErrorString);
    return false;
}

bool QNativeSocketEngine::bind(const QHostAddress &address, quint16 port)
{
    Q_D(QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::bind(), false);

#if defined (QT_NO_IPV6)
    if (address.protocol() == QAbstractSocket::IPv6Protocol) {
        d->setError(QAbstractSocket::UnsupportedSocketOperationError,
                    QNativeSocketEnginePrivate::NoIpV6ErrorString);
        return false;
    }
#endif
    if (!d->checkProxy(address))
        return false;

    Q_CHECK_STATE(QNativeSocketEngine::bind(), QAbstractSocket::UnconnectedState, false);

    if (!d->nativeBind(address, port))
        return false;

    d->fetchConnectionParameters();
    return true;
}

bool QNativeSocketEngine::listen()
{
    Q_D(QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::listen(), false);
    Q_CHECK_STATE(QNativeSocketEngine::listen(), QAbstractSocket::BoundState, false);
    Q_CHECK_TYPE(QNativeSocketEngine::listen(), QAbstractSocket::TcpSocket, false);

    // We're using a backlog of 50. Most modern kernels support TCP
    // syncookies by default, and if they do, the backlog is ignored.
    // When there is no support for TCP syncookies, this value is
    // fine.
    return d->nativeListen(50);
}

int QNativeSocketEngine::accept()
{
    Q_D(QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::accept(), -1);
    Q_CHECK_STATE(QNativeSocketEngine::accept(), QAbstractSocket::ListeningState, false);
    Q_CHECK_TYPE(QNativeSocketEngine::accept(), QAbstractSocket::TcpSocket, false);

    return d->nativeAccept();
}

#ifndef QT_NO_NETWORKINTERFACE

bool QNativeSocketEngine::joinMulticastGroup(const QHostAddress &groupAddress,
                                             const QNetworkInterface &iface)
{
    Q_D(QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::joinMulticastGroup(), false);
    Q_CHECK_STATE(QNativeSocketEngine::joinMulticastGroup(), QAbstractSocket::BoundState, false);
    Q_CHECK_TYPE(QNativeSocketEngine::joinMulticastGroup(), QAbstractSocket::UdpSocket, false);
    return d->nativeJoinMulticastGroup(groupAddress, iface);
}

bool QNativeSocketEngine::leaveMulticastGroup(const QHostAddress &groupAddress,
                                              const QNetworkInterface &iface)
{
    Q_D(QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::leaveMulticastGroup(), false);
    Q_CHECK_STATE(QNativeSocketEngine::leaveMulticastGroup(), QAbstractSocket::BoundState, false);
    Q_CHECK_TYPE(QNativeSocketEngine::leaveMulticastGroup(), QAbstractSocket::UdpSocket, false);
    return d->nativeLeaveMulticastGroup(groupAddress, iface);
}

QNetworkInterface QNativeSocketEngine::multicastInterface() const
{
    Q_D(const QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::multicastInterface(), QNetworkInterface());
    Q_CHECK_TYPE(QNativeSocketEngine::multicastInterface(), QAbstractSocket::UdpSocket, QNetworkInterface());
    return d->nativeMulticastInterface();
}

bool QNativeSocketEngine::setMulticastInterface(const QNetworkInterface &iface)
{
    Q_D(QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::setMulticastInterface(), false);
    Q_CHECK_TYPE(QNativeSocketEngine::setMulticastInterface(), QAbstractSocket::UdpSocket, false);
    return d->nativeSetMulticastInterface(iface);
}

#endif // QT_NO_NETWORKINTERFACE

qint64 QNativeSocketEngine::bytesAvailable() const
{
    Q_D(const QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::bytesAvailable(), -1);
    Q_CHECK_NOT_STATE(QNativeSocketEngine::bytesAvailable(), QAbstractSocket::UnconnectedState, false);

    return d->nativeBytesAvailable();
}

bool QNativeSocketEngine::hasPendingDatagrams() const
{
    Q_D(const QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::hasPendingDatagrams(), false);
    Q_CHECK_NOT_STATE(QNativeSocketEngine::hasPendingDatagrams(), QAbstractSocket::UnconnectedState, false);
    Q_CHECK_TYPE(QNativeSocketEngine::hasPendingDatagrams(), QAbstractSocket::UdpSocket, false);

    return d->nativeHasPendingDatagrams();
}

qint64 QNativeSocketEngine::pendingDatagramSize() const
{
    Q_D(const QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::pendingDatagramSize(), -1);
    Q_CHECK_TYPE(QNativeSocketEngine::pendingDatagramSize(), QAbstractSocket::UdpSocket, false);

    return d->nativePendingDatagramSize();
}

qint64 QNativeSocketEngine::readDatagram(char *data, qint64 maxSize, QHostAddress *address,
                                      quint16 *port)
{
    Q_D(QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::readDatagram(), -1);
    Q_CHECK_TYPE(QNativeSocketEngine::readDatagram(), QAbstractSocket::UdpSocket, false);

    return d->nativeReceiveDatagram(data, maxSize, address, port);
}

qint64 QNativeSocketEngine::writeDatagram(const char *data, qint64 size,
                                       const QHostAddress &host, quint16 port)
{
    Q_D(QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::writeDatagram(), -1);
    Q_CHECK_TYPE(QNativeSocketEngine::writeDatagram(), QAbstractSocket::UdpSocket, -1);
    return d->nativeSendDatagram(data, size, host, port);
}

qint64 QNativeSocketEngine::write(const char *data, qint64 size)
{
    Q_D(QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::write(), -1);
    Q_CHECK_STATE(QNativeSocketEngine::write(), QAbstractSocket::ConnectedState, -1);
    return d->nativeWrite(data, size);
}


qint64 QNativeSocketEngine::bytesToWrite() const
{
    return 0;
}

qint64 QNativeSocketEngine::read(char *data, qint64 maxSize)
{
    Q_D(QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::read(), -1);
    Q_CHECK_STATES(QNativeSocketEngine::read(), QAbstractSocket::ConnectedState, QAbstractSocket::BoundState, -1);

    qint64 readBytes = d->nativeRead(data, maxSize);

    // Handle remote close
    if (readBytes == 0 && d->socketType == QAbstractSocket::TcpSocket) {
        d->setError(QAbstractSocket::RemoteHostClosedError,
                    QNativeSocketEnginePrivate::RemoteHostClosedErrorString);
        close();
        return -1;
    } else if (readBytes == -1) {
        if (!d->hasSetSocketError) {
            d->hasSetSocketError = true;
            d->socketError = QAbstractSocket::NetworkError;
            d->socketErrorString = qt_error_string();
        }
        close();
        return -1;
    }
    return readBytes;
}

void QNativeSocketEngine::close()
{
    Q_D(QNativeSocketEngine);
    if (d->readNotifier)
        d->readNotifier->setEnabled(false);
    if (d->writeNotifier)
        d->writeNotifier->setEnabled(false);
    if (d->exceptNotifier)
        d->exceptNotifier->setEnabled(false);

    if(d->socketDescriptor != -1) {
        d->nativeClose();
        d->socketDescriptor = -1;
    }
    d->socketState = QAbstractSocket::UnconnectedState;
    d->hasSetSocketError = false;
    d->localPort = 0;
    d->localAddress.clear();
    d->peerPort = 0;
    d->peerAddress.clear();
    if (d->readNotifier) {
        qDeleteInEventHandler(d->readNotifier);
        d->readNotifier = 0;
    }
    if (d->writeNotifier) {
        qDeleteInEventHandler(d->writeNotifier);
        d->writeNotifier = 0;
    }
    if (d->exceptNotifier) {
        qDeleteInEventHandler(d->exceptNotifier);
        d->exceptNotifier = 0;
    }
}

bool QNativeSocketEngine::waitForRead(int msecs, bool *timedOut)
{
    Q_D(const QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::waitForRead(), false);
    Q_CHECK_NOT_STATE(QNativeSocketEngine::waitForRead(),
                      QAbstractSocket::UnconnectedState, false);

    if (timedOut)
        *timedOut = false;

    int ret = d->nativeSelect(msecs, true);
    if (ret == 0) {
        if (timedOut)
            *timedOut = true;
        d->setError(QAbstractSocket::SocketTimeoutError,
            QNativeSocketEnginePrivate::TimeOutErrorString);
        d->hasSetSocketError = false; // A timeout error is temporary in waitFor functions
        return false;
    } else if (state() == QAbstractSocket::ConnectingState) {
        connectToHost(d->peerAddress, d->peerPort);
    }

    return ret > 0;
}

bool QNativeSocketEngine::waitForWrite(int msecs, bool *timedOut)
{
    Q_D(QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::waitForWrite(), false);
    Q_CHECK_NOT_STATE(QNativeSocketEngine::waitForWrite(),
                      QAbstractSocket::UnconnectedState, false);

    if (timedOut)
        *timedOut = false;

    int ret = d->nativeSelect(msecs, false);
    // On Windows, the socket is in connected state if a call to
    // select(writable) is successful. In this case we should not
    // issue a second call to WSAConnect()
#if defined (Q_WS_WIN)
    if (ret > 0) {
        setState(QAbstractSocket::ConnectedState);
        d_func()->fetchConnectionParameters();
        return true;
    } else {
        int value = 0;
        int valueSize = sizeof(value);
        if (::getsockopt(d->socketDescriptor, SOL_SOCKET, SO_ERROR, (char *) &value, &valueSize) == 0) {
            if (value == WSAECONNREFUSED) {
                d->setError(QAbstractSocket::ConnectionRefusedError, QNativeSocketEnginePrivate::ConnectionRefusedErrorString);
                d->socketState = QAbstractSocket::UnconnectedState;
                return false;
            } else if (value == WSAETIMEDOUT) {
                d->setError(QAbstractSocket::NetworkError, QNativeSocketEnginePrivate::ConnectionTimeOutErrorString);
                d->socketState = QAbstractSocket::UnconnectedState;
                return false;
            } else if (value == WSAEHOSTUNREACH) {
                d->setError(QAbstractSocket::NetworkError, QNativeSocketEnginePrivate::HostUnreachableErrorString);
                d->socketState = QAbstractSocket::UnconnectedState;
                return false;
            }
        }
    }
#endif

    if (ret == 0) {
        if (timedOut)
            *timedOut = true;
        d->setError(QAbstractSocket::SocketTimeoutError,
                    QNativeSocketEnginePrivate::TimeOutErrorString);
        d->hasSetSocketError = false; // A timeout error is temporary in waitFor functions
        return false;
    } else if (state() == QAbstractSocket::ConnectingState) {
        connectToHost(d->peerAddress, d->peerPort);
    }

    return ret > 0;
}

bool QNativeSocketEngine::waitForReadOrWrite(bool *readyToRead, bool *readyToWrite,
                                      bool checkRead, bool checkWrite,
                                      int msecs, bool *timedOut)
{
    Q_D(QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::waitForWrite(), false);
    Q_CHECK_NOT_STATE(QNativeSocketEngine::waitForReadOrWrite(),
                      QAbstractSocket::UnconnectedState, false);

    int ret = d->nativeSelect(msecs, checkRead, checkWrite, readyToRead, readyToWrite);
    // On Windows, the socket is in connected state if a call to
    // select(writable) is successful. In this case we should not
    // issue a second call to WSAConnect()
#if defined (Q_WS_WIN)
    if (checkWrite && ((readyToWrite && *readyToWrite) || !readyToWrite) && ret > 0) {
        setState(QAbstractSocket::ConnectedState);
        d_func()->fetchConnectionParameters();
        return true;
    } else {
        int value = 0;
        int valueSize = sizeof(value);
        if (::getsockopt(d->socketDescriptor, SOL_SOCKET, SO_ERROR, (char *) &value, &valueSize) == 0) {
            if (value == WSAECONNREFUSED) {
                d->setError(QAbstractSocket::ConnectionRefusedError, QNativeSocketEnginePrivate::ConnectionRefusedErrorString);
                d->socketState = QAbstractSocket::UnconnectedState;
                return false;
            } else if (value == WSAETIMEDOUT) {
                d->setError(QAbstractSocket::NetworkError, QNativeSocketEnginePrivate::ConnectionTimeOutErrorString);
                d->socketState = QAbstractSocket::UnconnectedState;
                return false;
            } else if (value == WSAEHOSTUNREACH) {
                d->setError(QAbstractSocket::NetworkError, QNativeSocketEnginePrivate::HostUnreachableErrorString);
                d->socketState = QAbstractSocket::UnconnectedState;
                return false;
            }
        }
    }
#endif
    if (ret == 0) {
        if (timedOut)
            *timedOut = true;
        d->setError(QAbstractSocket::SocketTimeoutError,
                    QNativeSocketEnginePrivate::TimeOutErrorString);
        d->hasSetSocketError = false; // A timeout error is temporary in waitFor functions
        return false;
    } else if (state() == QAbstractSocket::ConnectingState) {
        connectToHost(d->peerAddress, d->peerPort);
    }

    return ret > 0;
}

qint64 QNativeSocketEngine::receiveBufferSize() const
{
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::receiveBufferSize(), -1);
    return option(ReceiveBufferSocketOption);
}

void QNativeSocketEngine::setReceiveBufferSize(qint64 size)
{
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::setReceiveBufferSize(), Q_VOID);
    setOption(ReceiveBufferSocketOption, size);
}

qint64 QNativeSocketEngine::sendBufferSize() const
{
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::setSendBufferSize(), -1);
    return option(SendBufferSocketOption);
}

void QNativeSocketEngine::setSendBufferSize(qint64 size)
{
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::setSendBufferSize(), Q_VOID);
    setOption(SendBufferSocketOption, size);
}


bool QNativeSocketEngine::setOption(SocketOption option, int value)
{
    Q_D(QNativeSocketEngine);
    return d->setOption(option, value);
}

int QNativeSocketEngine::option(SocketOption socketOption) const
{
    Q_D(const QNativeSocketEngine);
    return d->option(socketOption);
}

bool QNativeSocketEngine::isReadNotificationEnabled() const
{
    Q_D(const QNativeSocketEngine);
    return d->readNotifier && d->readNotifier->isEnabled();
}

/*
  \internal
  \class QReadNotifier
  \brief The QReadNotifer class is used to improve performance.

  QReadNotifier is a private class used for performance reasons vs
  connecting to the QSocketNotifier activated() signal.
 */
class QReadNotifier : public QSocketNotifier
{
public:
    QReadNotifier(int fd, QNativeSocketEngine *parent)
        : QSocketNotifier(fd, QSocketNotifier::Read, parent)
    { engine = parent; }

protected:
    bool event(QEvent *);

    QNativeSocketEngine *engine;
};

bool QReadNotifier::event(QEvent *e)
{
    if (e->type() == QEvent::SockAct) {
        engine->readNotification();
        return true;
    }
    return QSocketNotifier::event(e);
}

/*
  \internal
  \class QWriteNotifier
  \brief The QWriteNotifer class is used to improve performance.

  QWriteNotifier is a private class used for performance reasons vs
  connecting to the QSocketNotifier activated() signal.
 */
class QWriteNotifier : public QSocketNotifier
{
public:
    QWriteNotifier(int fd, QNativeSocketEngine *parent)
        : QSocketNotifier(fd, QSocketNotifier::Write, parent) { engine = parent; }

protected:
    bool event(QEvent *);

    QNativeSocketEngine *engine;
};

bool QWriteNotifier::event(QEvent *e)
{
    if (e->type() == QEvent::SockAct) {
        if (engine->state() == QAbstractSocket::ConnectingState)
            engine->connectionNotification();
        else
            engine->writeNotification();
        return true;
    }
    return QSocketNotifier::event(e);
}

class QExceptionNotifier : public QSocketNotifier
{
public:
    QExceptionNotifier(int fd, QNativeSocketEngine *parent)
        : QSocketNotifier(fd, QSocketNotifier::Exception, parent) { engine = parent; }

protected:
    bool event(QEvent *);

    QNativeSocketEngine *engine;
};

bool QExceptionNotifier::event(QEvent *e)
{
    if (e->type() == QEvent::SockAct) {
        if (engine->state() == QAbstractSocket::ConnectingState)
            engine->connectionNotification();
        else
            engine->exceptionNotification();
        return true;
    }
    return QSocketNotifier::event(e);
}

void QNativeSocketEngine::setReadNotificationEnabled(bool enable)
{
    Q_D(QNativeSocketEngine);
    if (d->readNotifier) {
        d->readNotifier->setEnabled(enable);
    } else if (enable && d->threadData->eventDispatcher) {
        d->readNotifier = new QReadNotifier(d->socketDescriptor, this);
        d->readNotifier->setEnabled(true);
    }
}

bool QNativeSocketEngine::isWriteNotificationEnabled() const
{
    Q_D(const QNativeSocketEngine);
    return d->writeNotifier && d->writeNotifier->isEnabled();
}

void QNativeSocketEngine::setWriteNotificationEnabled(bool enable)
{
    Q_D(QNativeSocketEngine);
    if (d->writeNotifier) {
        d->writeNotifier->setEnabled(enable);
    } else if (enable && d->threadData->eventDispatcher) {
        d->writeNotifier = new QWriteNotifier(d->socketDescriptor, this);
        d->writeNotifier->setEnabled(true);
    }
}

bool QNativeSocketEngine::isExceptionNotificationEnabled() const
{
    Q_D(const QNativeSocketEngine);
    return d->exceptNotifier && d->exceptNotifier->isEnabled();
}

void QNativeSocketEngine::setExceptionNotificationEnabled(bool enable)
{
    Q_D(QNativeSocketEngine);
    if (d->exceptNotifier) {
        d->exceptNotifier->setEnabled(enable);
    } else if (enable && d->threadData->eventDispatcher) {
        d->exceptNotifier = new QExceptionNotifier(d->socketDescriptor, this);
        d->exceptNotifier->setEnabled(true);
    }
}

QT_END_NAMESPACE