// 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

// Qt-Security score:significant reason:load-external-library-via-qlibrary

#include "qdbus_symbols_p.h"

#include <QtCore/qlatin1stringview.h>

#if QT_CONFIG(library)

#include <QtCore/qlibrary.h>

#include <QtCore/private/qlocking_p.h>

#endif

#include <QtCore/qmutex.h>

#ifndef QT_NO_DBUS

QT_BEGIN_NAMESPACE

using namespace Qt::StringLiterals;

#if !defined QT_LINKED_LIBDBUS

#if QT_CONFIG(library)

Q_CONSTINIT static QLibrary *qdbus_libdbus = nullptr;

void qdbus_unloadLibDBus()

{

    if (qdbus_libdbus) {

        if (qEnvironmentVariableIsSet("QDBUS_FORCE_SHUTDOWN"))

            qdbus_libdbus->resolve("dbus_shutdown")();

        qdbus_libdbus->unload();

    }

    delete qdbus_libdbus;

    qdbus_libdbus = nullptr;

}

#endif

bool qdbus_loadLibDBus()

{

#if QT_CONFIG(library)

#ifdef QT_BUILD_INTERNAL

    // this is to simulate a library load failure for our autotest suite.

    if (!qEnvironmentVariableIsEmpty("QT_SIMULATE_DBUS_LIBFAIL"))

        return false;

#endif

    Q_CONSTINIT static bool triedToLoadLibrary = false;

    Q_CONSTINIT static QBasicMutex mutex;

    const auto locker = qt_scoped_lock(mutex);

    QLibrary *&lib = qdbus_libdbus;

    if (triedToLoadLibrary)

        return lib && lib->isLoaded();

    lib = new QLibrary;

    lib->setLoadHints(QLibrary::ExportExternalSymbolsHint); // make libdbus symbols available for apps that need more advanced control over the dbus

    triedToLoadLibrary = true;

    static constexpr int majorversions[] = { 3, 2, -1 };

    const QString baseNames[] = {

#ifdef Q_OS_WIN

        "dbus-1"_L1,

#endif

        "libdbus-1"_L1

    };

    lib->unload();

    for (const int majorversion : majorversions) {

        for (const QString &baseName : baseNames) {

#ifdef Q_OS_WIN

            QString suffix;

            if (majorversion != -1)

                suffix = QString::number(- majorversion); // negative so it prepends the dash

            lib->setFileName(baseName + suffix);

#else

            lib->setFileNameAndVersion(baseName, majorversion);

#endif

            if (lib->load() && lib->resolve("dbus_connection_open_private"))

                return true;

            lib->unload();

        }

    }

    delete lib;

    lib = nullptr;

    return false;

#else

    return true;

#endif

}

QFunctionPointer qdbus_resolve_conditionally(const char *name)

{

#if QT_CONFIG(library)

    if (qdbus_loadLibDBus())

        return qdbus_libdbus->resolve(name);

#else

    Q_UNUSED(name);

#endif

    return nullptr;

}

QFunctionPointer qdbus_resolve_me(const char *name)

{

#if QT_CONFIG(library)

    if (Q_UNLIKELY(!qdbus_loadLibDBus()))

        qFatal("Cannot find libdbus-1 in your system to resolve symbol '%s'.", name);

    QFunctionPointer ptr = qdbus_libdbus->resolve(name);

    if (Q_UNLIKELY(!ptr))

        qFatal("Cannot resolve '%s' in your libdbus-1.", name);

    return ptr;

#else

    Q_UNUSED(name);

    return nullptr;

#endif

}

#else

static void qdbus_unloadLibDBus()

{

    if (qEnvironmentVariableIsSet("QDBUS_FORCE_SHUTDOWN"))

        dbus_shutdown();

}

#endif // !QT_LINKED_LIBDBUS

#if defined(QT_LINKED_LIBDBUS) || QT_CONFIG(library)

Q_DESTRUCTOR_FUNCTION(qdbus_unloadLibDBus)

#endif

QT_END_NAMESPACE

#endif // QT_NO_DBUS