qnativesocketengine.cpp

Go to the documentation of this file.

// Copyright (C) 2016 The Qt Company Ltd.
// Copyright (C) 2016 Intel Corporation.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
//#define QNATIVESOCKETENGINE_DEBUG
 
#include "qnativesocketengine_p_p.h"
 
#include <qabstracteventdispatcher.h>
#include <qsocketnotifier.h>
#include <qnetworkinterface.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
 
#if !defined(QT_NO_SCTP)
# include "qsctpserver.h"
#endif
 
QT_BEGIN_NAMESPACE
 
using namespace Qt::StringLiterals;
 
//#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_STATES3(function, state1, state2, state3, returnValue) do { \
    if (d->socketState != (state1) && d->socketState != (state2) && d->socketState != (state3)) { \
        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_CHECK_TYPES(function, type1, type2, returnValue) do { \
    if (d->socketType != (type1) && d->socketType != (type2)) { \
        qWarning(#function" was called by a" \
                 " socket other than "#type1" or "#type2); \
        return (returnValue); \
    } } while (0)
#define Q_TR(a) QT_TRANSLATE_NOOP(QNativeSocketEngine, a)
 
QNativeSocketEnginePrivate::QNativeSocketEnginePrivate() :
    socketDescriptor(-1),
    readNotifier(nullptr),
    writeNotifier(nullptr),
    exceptNotifier(nullptr)
{
#if defined(Q_OS_WIN)
    QSysInfo::machineHostName();        // this initializes ws2_32.dll
#endif
}
 
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;
    // should not happen anymore
    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 TemporaryErrorString:
        socketErrorString = QNativeSocketEngine::tr("Temporary error");
        break;
    case NetworkDroppedConnectionErrorString:
        socketErrorString = QNativeSocketEngine::tr("Network dropped connection on reset");
        break;
    case ConnectionResetErrorString:
        socketErrorString = QNativeSocketEngine::tr("Connection reset by peer");
        break;
    case UnknownSocketErrorString:
        socketErrorString = QNativeSocketEngine::tr("Unknown error");
        break;
    }
}
 
QHostAddress QNativeSocketEnginePrivate::adjustAddressProtocol(const QHostAddress &address) const
{
    QAbstractSocket::NetworkLayerProtocol targetProtocol = socketProtocol;
    if (Q_LIKELY(targetProtocol == QAbstractSocket::UnknownNetworkLayerProtocol))
        return address;
 
    QAbstractSocket::NetworkLayerProtocol sourceProtocol = address.protocol();
 
    if (targetProtocol == QAbstractSocket::AnyIPProtocol)
        targetProtocol = QAbstractSocket::IPv6Protocol;
    if (targetProtocol == QAbstractSocket::IPv6Protocol && sourceProtocol == QAbstractSocket::IPv4Protocol) {
        // convert to IPv6 v4-mapped address. This always works
        return QHostAddress(address.toIPv6Address());
    }
 
    if (targetProtocol == QAbstractSocket::IPv4Protocol && sourceProtocol == QAbstractSocket::IPv6Protocol) {
        // convert to IPv4 if the source is a v4-mapped address
        quint32 ip4 = address.toIPv4Address();
        if (ip4)
            return QHostAddress(ip4);
    }
 
    return address;
}
 
bool QNativeSocketEnginePrivate::checkProxy(const QHostAddress &address)
{
    if (address.isLoopback())
        return true;
 
#if !defined(QT_NO_NETWORKPROXY)
    QObject *parent = q_func()->parent();
    QNetworkProxy proxy;
    QNetworkProxyQuery::QueryType queryType = QNetworkProxyQuery::TcpSocket;
    if (QAbstractSocket *socket = qobject_cast<QAbstractSocket *>(parent)) {
        proxy = socket->proxy();
        switch (socket->socketType()) {
        case QAbstractSocket::UdpSocket:
            queryType = QNetworkProxyQuery::UdpSocket;
            break;
        case QAbstractSocket::SctpSocket:
            queryType = QNetworkProxyQuery::SctpSocket;
            break;
        case QAbstractSocket::TcpSocket:
        case QAbstractSocket::UnknownSocketType:
            queryType = QNetworkProxyQuery::TcpSocket;
        }
    } else if (QTcpServer *server = qobject_cast<QTcpServer *>(parent)) {
        proxy = server->proxy();
        queryType = QNetworkProxyQuery::TcpServer;
#ifndef QT_NO_SCTP
        if (qobject_cast<QSctpServer *>(server))
            queryType = QNetworkProxyQuery::SctpServer;
#endif
    } else {
        // no parent -> no proxy
        return true;
    }
 
    if (proxy.type() == QNetworkProxy::DefaultProxy) {
        // This is similar to what we have in QNetworkProxy::applicationProxy,
        // the only difference is that we provide the correct query type instead of
        // always using TcpSocket unconditionally (this is the default type for
        // QNetworkProxyQuery).
        QNetworkProxyQuery query;
        query.setQueryType(queryType);
        proxy = QNetworkProxyFactory::proxyForQuery(query).constFirst();
    }
 
    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();
 
    // Create the socket
    if (!d->createNewSocket(socketType, protocol)) {
#if defined (QNATIVESOCKETENGINE_DEBUG)
        QString typeStr = "UnknownSocketType"_L1;
        if (socketType == QAbstractSocket::TcpSocket) typeStr = "TcpSocket"_L1;
        else if (socketType == QAbstractSocket::UdpSocket) typeStr = "UdpSocket"_L1;
        else if (socketType == QAbstractSocket::SctpSocket) typeStr = "SctpSocket"_L1;
        QString protocolStr = "UnknownProtocol"_L1;
        if (protocol == QAbstractSocket::IPv4Protocol) protocolStr = "IPv4Protocol"_L1;
        else if (protocol == QAbstractSocket::IPv6Protocol) protocolStr = "IPv6Protocol"_L1;
        qDebug("QNativeSocketEngine::initialize(type == %s, protocol == %s) failed: %s",
               typeStr.toLatin1().constData(), protocolStr.toLatin1().constData(), d->socketErrorString.toLatin1().constData());
#endif
        return false;
    }
 
    if (socketType == QAbstractSocket::UdpSocket) {
        // Set the broadcasting flag if it's a UDP socket.
        if (!setOption(BroadcastSocketOption, 1)) {
            d->setError(QAbstractSocket::UnsupportedSocketOperationError,
                        QNativeSocketEnginePrivate::BroadcastingInitFailedErrorString);
            close();
            return false;
        }
 
        // Set some extra flags that are interesting to us, but accept failure
        setOption(ReceivePacketInformation, 1);
        setOption(ReceiveHopLimit, 1);
    }
 
 
#ifndef Q_OS_WASM
    // 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");
    }
#endif
 
    // 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 explicitly 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);
 
    return true;
}
 
bool QNativeSocketEngine::initialize(qintptr 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) failed:"
                 << socketDescriptor << d->socketErrorString;
#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;
}
 
qintptr 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 (!d->checkProxy(address))
        return false;
 
    Q_CHECK_STATES3(QNativeSocketEngine::connectToHost(), QAbstractSocket::BoundState,
                   QAbstractSocket::UnconnectedState, QAbstractSocket::ConnectingState, false);
 
    d->peerAddress = address;
    d->peerPort = port;
    bool connected = d->nativeConnect(d->adjustAddressProtocol(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 (!d->checkProxy(address))
        return false;
 
    Q_CHECK_STATE(QNativeSocketEngine::bind(), QAbstractSocket::UnconnectedState, false);
 
    if (!d->nativeBind(d->adjustAddressProtocol(address), port))
        return false;
 
    d->fetchConnectionParameters();
    return true;
}
 
bool QNativeSocketEngine::listen(int backlog)
{
    Q_D(QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::listen(), false);
    Q_CHECK_STATE(QNativeSocketEngine::listen(), QAbstractSocket::BoundState, false);
#ifndef QT_NO_SCTP
    Q_CHECK_TYPES(QNativeSocketEngine::listen(), QAbstractSocket::TcpSocket,
                  QAbstractSocket::SctpSocket, false);
#else
    Q_CHECK_TYPE(QNativeSocketEngine::listen(), QAbstractSocket::TcpSocket, false);
#endif
 
    return d->nativeListen(backlog);
}
 
qintptr QNativeSocketEngine::accept()
{
    Q_D(QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::accept(), -1);
    Q_CHECK_STATE(QNativeSocketEngine::accept(), QAbstractSocket::ListeningState, -1);
#ifndef QT_NO_SCTP
    Q_CHECK_TYPES(QNativeSocketEngine::accept(), QAbstractSocket::TcpSocket,
                  QAbstractSocket::SctpSocket, -1);
#else
    Q_CHECK_TYPE(QNativeSocketEngine::accept(), QAbstractSocket::TcpSocket, -1);
#endif
 
    return d->nativeAccept();
}
 
qint64 QNativeSocketEngine::bytesAvailable() const
{
    Q_D(const QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::bytesAvailable(), -1);
    Q_CHECK_NOT_STATE(QNativeSocketEngine::bytesAvailable(), QAbstractSocket::UnconnectedState, -1);
 
    return d->nativeBytesAvailable();
}
 
#ifndef QT_NO_UDPSOCKET
#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);
 
    // if the user binds a socket to an IPv6 address (or QHostAddress::Any) and
    // then attempts to join an IPv4 multicast group, this won't work on
    // Windows. In order to make this cross-platform, we warn & fail on all
    // platforms.
    if (groupAddress.protocol() == QAbstractSocket::IPv4Protocol &&
        (d->socketProtocol == QAbstractSocket::IPv6Protocol ||
         d->socketProtocol == QAbstractSocket::AnyIPProtocol)) {
        qWarning("QAbstractSocket: cannot bind to QHostAddress::Any (or an IPv6 address) and join an IPv4 multicast group;"
                 " bind to QHostAddress::AnyIPv4 instead if you want to do this");
        return 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
 
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, -1);
 
    return d->nativePendingDatagramSize();
}
#endif // QT_NO_UDPSOCKET
 
qint64 QNativeSocketEngine::readDatagram(char *data, qint64 maxSize, QIpPacketHeader *header,
                                         PacketHeaderOptions options)
{
    Q_D(QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::readDatagram(), -1);
    Q_CHECK_STATES(QNativeSocketEngine::readDatagram(), QAbstractSocket::BoundState,
                   QAbstractSocket::ConnectedState, -1);
 
    return d->nativeReceiveDatagram(data, maxSize, header, options);
}
 
qint64 QNativeSocketEngine::writeDatagram(const char *data, qint64 size, const QIpPacketHeader &header)
{
    Q_D(QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::writeDatagram(), -1);
    Q_CHECK_STATES(QNativeSocketEngine::writeDatagram(), QAbstractSocket::BoundState,
                   QAbstractSocket::ConnectedState, -1);
 
    return d->nativeSendDatagram(data, size, header);
}
 
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
#ifndef QT_NO_SCTP
        || d->socketType == QAbstractSocket::SctpSocket
#endif
        )) {
        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();
    d->inboundStreamCount = d->outboundStreamCount = 0;
    if (d->readNotifier) {
        delete d->readNotifier;
        d->readNotifier = nullptr;
    }
    if (d->writeNotifier) {
        delete d->writeNotifier;
        d->writeNotifier = nullptr;
    }
    if (d->exceptNotifier) {
        delete d->exceptNotifier;
        d->exceptNotifier = nullptr;
    }
}
 
bool QNativeSocketEngine::waitForRead(QDeadlineTimer deadline, 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(deadline, 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(QDeadlineTimer deadline, 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(deadline, 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_OS_WIN)
    if (state() == QAbstractSocket::ConnectingState) {
        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 || (state() == QAbstractSocket::BoundState && d->socketDescriptor != -1)) {
        connectToHost(d->peerAddress, d->peerPort);
    }
 
    return ret > 0;
}
 
bool QNativeSocketEngine::waitForReadOrWrite(bool *readyToRead, bool *readyToWrite,
                                      bool checkRead, bool checkWrite,
                                      QDeadlineTimer deadline, bool *timedOut)
{
    Q_D(QNativeSocketEngine);
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::waitForReadOrWrite(), false);
    Q_CHECK_NOT_STATE(QNativeSocketEngine::waitForReadOrWrite(),
                      QAbstractSocket::UnconnectedState, false);
 
    int ret = d->nativeSelect(deadline, 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_OS_WIN)
    if (state() == QAbstractSocket::ConnectingState) {
        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;
}
 
#if 0   // currently unused
/*
    Returns the size of the operating system's socket receive
    buffer. Depending on the operating system, this size may be
    different from what has been set earlier with
    setReceiveBufferSize().
*/
qint64 QNativeSocketEngine::receiveBufferSize() const
{
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::receiveBufferSize(), -1);
    return option(ReceiveBufferSocketOption);
}
 
/*
    Sets the size of the operating system receive buffer to \a size.
 
    For clients, this should be set before connectToHost() is called;
    otherwise it will have no effect. For servers, it should be called
    before listen().
 
    The operating system receive buffer size effectively limits two
    things: how much data can be in transit at any one moment, and how
    much data can be received in one iteration of the main event loop.
    Setting the size of the receive buffer may have an impact on the
    socket's performance.
 
    The default value is operating system-dependent.
*/
void QNativeSocketEngine::setReceiveBufferSize(qint64 size)
{
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::setReceiveBufferSize(), Q_VOID);
    setOption(ReceiveBufferSocketOption, size);
}
 
/*
    Returns the size of the operating system send buffer. Depending on
    the operating system, this size may be different from what has
    been set earlier with setSendBufferSize().
*/
qint64 QNativeSocketEngine::sendBufferSize() const
{
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::setSendBufferSize(), -1);
    return option(SendBufferSocketOption);
}
 
/*
    Sets the size of the operating system send buffer to \a size.
 
    The operating system send buffer size effectively limits how much
    data can be in transit at any one moment. Setting the size of the
    send buffer may have an impact on the socket's performance.
 
    The default value is operating system-dependent.
*/
void QNativeSocketEngine::setSendBufferSize(qint64 size)
{
    Q_CHECK_VALID_SOCKETLAYER(QNativeSocketEngine::setSendBufferSize(), Q_VOID);
    setOption(SendBufferSocketOption, size);
}
#endif
 
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(qintptr fd, QNativeSocketEngine *parent)
        : QSocketNotifier(fd, QSocketNotifier::Read, parent)
    { engine = parent; }
 
protected:
    bool event(QEvent *) override;
 
    QNativeSocketEngine *engine;
};
 
bool QReadNotifier::event(QEvent *e)
{
    if (e->type() == QEvent::SockAct) {
        engine->readNotification();
        return true;
    } else if (e->type() == QEvent::SockClose) {
        engine->closeNotification();
        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(qintptr fd, QNativeSocketEngine *parent)
        : QSocketNotifier(fd, QSocketNotifier::Write, parent) { engine = parent; }
 
protected:
    bool event(QEvent *) override;
 
    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(qintptr fd, QNativeSocketEngine *parent)
        : QSocketNotifier(fd, QSocketNotifier::Exception, parent) { engine = parent; }
 
protected:
    bool event(QEvent *) override;
 
    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.loadRelaxed()->hasEventDispatcher()) {
        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.loadRelaxed()->hasEventDispatcher()) {
        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.loadRelaxed()->hasEventDispatcher()) {
        d->exceptNotifier = new QExceptionNotifier(d->socketDescriptor, this);
        d->exceptNotifier->setEnabled(true);
    }
}
 
QT_END_NAMESPACE
 
#include "moc_qnativesocketengine_p.cpp"