File indexing completed on 2024-05-05 16:05:15

 /*
     SPDX-FileCopyrightText: 2008 Nicola Gigante <nicola.gigante@gmail.com>
     SPDX-FileCopyrightText: 2009-2010 Dario Freddi <drf@kde.org>
     SPDX-FileCopyrightText: 2020 Harald Sitter <sitter@kde.org>
 
     SPDX-License-Identifier: LGPL-2.1-or-later
 */
 
 #include "DBusHelperProxy.h"
 #include "BackendsManager.h"
 #include "kauthdebug.h"
 #include "kf5authadaptor.h"
 
 #include <QDBusConnectionInterface>
 #include <QDBusMessage>
 #include <QMap>
 #include <QMetaMethod>
 #include <QObject>
 #include <QTimer>
 #include <qplugin.h>
 
 #if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
 extern Q_CORE_EXPORT const QtPrivate::QMetaTypeInterface *qMetaTypeGuiHelper;
 #else
 extern Q_CORE_EXPORT const QMetaTypeInterface *qMetaTypeGuiHelper;
 #endif
 
 namespace KAuth
 {
 static void debugMessageReceived(int t, const QString &message);
 
 DBusHelperProxy::DBusHelperProxy()
     : responder(nullptr)
     , m_stopRequest(false)
     , m_busConnection(QDBusConnection::systemBus())
 {
 }
 
 DBusHelperProxy::DBusHelperProxy(const QDBusConnection &busConnection)
     : responder(nullptr)
     , m_stopRequest(false)
     , m_busConnection(busConnection)
 {
 }
 
 DBusHelperProxy::~DBusHelperProxy()
 {
 }
 
 void DBusHelperProxy::stopAction(const QString &action, const QString &helperID)
 {
     QDBusMessage message;
     message = QDBusMessage::createMethodCall(helperID, QLatin1String("/"), QLatin1String("org.kde.kf5auth"), QLatin1String("stopAction"));
 
     QList<QVariant> args;
     args << action;
     message.setArguments(args);
 
     m_busConnection.asyncCall(message);
 }
 
 void DBusHelperProxy::executeAction(const QString &action, const QString &helperID, const DetailsMap &details, const QVariantMap &arguments, int timeout)
 {
     QByteArray blob;
     {
         QDataStream stream(&blob, QIODevice::WriteOnly);
         stream << arguments;
     }
 
     // on unit tests we won't have a service, but the service will already be running
     const auto reply = m_busConnection.interface()->startService(helperID);
     if (!reply.isValid() && !m_busConnection.interface()->isServiceRegistered(helperID)) {
         ActionReply errorReply = ActionReply::DBusErrorReply();
         errorReply.setErrorDescription(tr("DBus Backend error: service start %1 failed: %2").arg(helperID, reply.error().message()));
         Q_EMIT actionPerformed(action, errorReply);
         return;
     }
 
     const bool connected = m_busConnection.connect(helperID,
                                                    QLatin1String("/"),
                                                    QLatin1String("org.kde.kf5auth"),
                                                    QLatin1String("remoteSignal"),
                                                    this,
                                                    SLOT(remoteSignalReceived(int, QString, QByteArray)));
 
     // if already connected reply will be false but we won't have an error or a reason to fail
     if (!connected && m_busConnection.lastError().isValid()) {
         ActionReply errorReply = ActionReply::DBusErrorReply();
         errorReply.setErrorDescription(tr("DBus Backend error: connection to helper failed. %1\n(application: %2 helper: %3)")
                                            .arg(m_busConnection.lastError().message(), qApp->applicationName(), helperID));
         Q_EMIT actionPerformed(action, errorReply);
         return;
     }
 
     QDBusMessage message;
     message = QDBusMessage::createMethodCall(helperID, QLatin1String("/"), QLatin1String("org.kde.kf5auth"), QLatin1String("performAction"));
 
     QList<QVariant> args;
     args << action << BackendsManager::authBackend()->callerID() << BackendsManager::authBackend()->backendDetails(details) << blob;
     message.setArguments(args);
 
     m_actionsInProgress.push_back(action);
 
     QDBusPendingCall pendingCall = m_busConnection.asyncCall(message, timeout);
 
     auto watcher = new QDBusPendingCallWatcher(pendingCall, this);
 
     connect(watcher, &QDBusPendingCallWatcher::finished, this, [=]() mutable {
         watcher->deleteLater();
 
         QDBusMessage reply = watcher->reply();
 
         if (reply.type() == QDBusMessage::ErrorMessage) {
             if (watcher->error().type() == QDBusError::InvalidArgs) {
                 // For backwards compatibility if helper binary was built with older KAuth version.
                 args.removeAt(args.count() - 2); // remove backend details
                 message.setArguments(args);
                 reply = m_busConnection.call(message, QDBus::Block, timeout);
                 if (reply.type() != QDBusMessage::ErrorMessage) {
                     return;
                 }
             }
             ActionReply r = ActionReply::DBusErrorReply();
             r.setErrorDescription(tr("DBus Backend error: could not contact the helper. "
                                      "Connection error: %1. Message error: %2")
                                       .arg(reply.errorMessage(), m_busConnection.lastError().message()));
             qCWarning(KAUTH) << reply.errorMessage();
 
             Q_EMIT actionPerformed(action, r);
         }
     });
 }
 
 bool DBusHelperProxy::initHelper(const QString &name)
 {
     new Kf5authAdaptor(this);
 
     if (!m_busConnection.registerService(name)) {
         qCWarning(KAUTH) << "Error registering helper DBus service" << name << m_busConnection.lastError().message();
         return false;
     }
 
     if (!m_busConnection.registerObject(QLatin1String("/"), this)) {
         qCWarning(KAUTH) << "Error registering helper DBus object:" << m_busConnection.lastError().message();
         return false;
     }
 
     m_name = name;
 
     return true;
 }
 
 void DBusHelperProxy::setHelperResponder(QObject *o)
 {
     responder = o;
 }
 
 void DBusHelperProxy::remoteSignalReceived(int t, const QString &action, QByteArray blob)
 {
     SignalType type = static_cast<SignalType>(t);
     QDataStream stream(&blob, QIODevice::ReadOnly);
 
     if (type == ActionStarted) {
         Q_EMIT actionStarted(action);
     } else if (type == ActionPerformed) {
         ActionReply reply = ActionReply::deserialize(blob);
 
         m_actionsInProgress.removeOne(action);
         Q_EMIT actionPerformed(action, reply);
     } else if (type == DebugMessage) {
         int level;
         QString message;
 
         stream >> level >> message;
 
         debugMessageReceived(level, message);
     } else if (type == ProgressStepIndicator) {
         int step;
         stream >> step;
 
         Q_EMIT progressStep(action, step);
     } else if (type == ProgressStepData) {
         QVariantMap data;
         stream >> data;
         Q_EMIT progressStepData(action, data);
     }
 }
 
 void DBusHelperProxy::stopAction(const QString &action)
 {
     Q_UNUSED(action)
     //#warning FIXME: The stop request should be action-specific rather than global
     m_stopRequest = true;
 }
 
 bool DBusHelperProxy::hasToStopAction()
 {
     QEventLoop loop;
     loop.processEvents(QEventLoop::AllEvents);
 
     return m_stopRequest;
 }
 
 bool DBusHelperProxy::isCallerAuthorized(const QString &action, const QByteArray &callerID, const QVariantMap &details)
 {
     // Check the caller is really who it says it is
     switch (BackendsManager::authBackend()->extraCallerIDVerificationMethod()) {
     case AuthBackend::NoExtraCallerIDVerificationMethod:
         break;
 
     case AuthBackend::VerifyAgainstDBusServiceName:
         if (message().service().toUtf8() != callerID) {
             return false;
         }
         break;
 
     case AuthBackend::VerifyAgainstDBusServicePid:
         if (connection().interface()->servicePid(message().service()).value() != callerID.toUInt()) {
             return false;
         }
         break;
     }
 
     return BackendsManager::authBackend()->isCallerAuthorized(action, callerID, details);
 }
 
 QByteArray DBusHelperProxy::performAction(const QString &action, const QByteArray &callerID, const QVariantMap &details, QByteArray arguments)
 {
     if (!responder) {
         return ActionReply::NoResponderReply().serialized();
     }
 
     if (!m_currentAction.isEmpty()) {
         return ActionReply::HelperBusyReply().serialized();
     }
 
     // Make sure we don't try restoring gui variants, in particular QImage/QPixmap/QIcon are super dangerous
     // since they end up calling the image loaders and thus are a vector for crashing → executing code
     auto origMetaTypeGuiHelper = qMetaTypeGuiHelper;
     qMetaTypeGuiHelper = nullptr;
 
     QVariantMap args;
     QDataStream s(&arguments, QIODevice::ReadOnly);
     s >> args;
 
     qMetaTypeGuiHelper = origMetaTypeGuiHelper;
 
     m_currentAction = action;
     Q_EMIT remoteSignal(ActionStarted, action, QByteArray());
     QEventLoop e;
     e.processEvents(QEventLoop::AllEvents);
 
     ActionReply retVal;
 
     QTimer *timer = responder->property("__KAuth_Helper_Shutdown_Timer").value<QTimer *>();
     timer->stop();
 
     if (isCallerAuthorized(action, callerID, details)) {
         QString slotname = action;
         if (slotname.startsWith(m_name + QLatin1Char('.'))) {
             slotname = slotname.right(slotname.length() - m_name.length() - 1);
         }
 
         slotname.replace(QLatin1Char('.'), QLatin1Char('_'));
 
         // For legacy reasons we could be dealing with ActionReply types (i.e.
         // `using namespace KAuth`). Since Qt type names are verbatim this would
         // mismatch a return type that is called 'KAuth::ActionReply' and
         // vice versa. This effectively required client code to always 'use' the
         // namespace as otherwise we'd not be able to call into it.
         // To support both scenarios we now dynamically determine what kind of return type
         // we deal with and call Q_RETURN_ARG either with or without namespace.
         const auto metaObj = responder->metaObject();
         const QString slotSignature(slotname + QStringLiteral("(QVariantMap)"));
         const QMetaMethod method = metaObj->method(metaObj->indexOfMethod(qPrintable(slotSignature)));
         if (method.isValid()) {
             const auto needle = "KAuth::";
             bool success = false;
             if (strncmp(needle, method.typeName(), strlen(needle)) == 0) {
                 success = method.invoke(responder, Qt::DirectConnection, Q_RETURN_ARG(KAuth::ActionReply, retVal), Q_ARG(QVariantMap, args));
             } else {
                 success = method.invoke(responder, Qt::DirectConnection, Q_RETURN_ARG(ActionReply, retVal), Q_ARG(QVariantMap, args));
             }
             if (!success) {
                 retVal = ActionReply::NoSuchActionReply();
             }
         } else {
             retVal = ActionReply::NoSuchActionReply();
         }
     } else {
         retVal = ActionReply::AuthorizationDeniedReply();
     }
 
     timer->start();
 
     Q_EMIT remoteSignal(ActionPerformed, action, retVal.serialized());
     e.processEvents(QEventLoop::AllEvents);
     m_currentAction.clear();
     m_stopRequest = false;
 
     return retVal.serialized();
 }
 
 void DBusHelperProxy::sendDebugMessage(int level, const char *msg)
 {
     QByteArray blob;
     QDataStream stream(&blob, QIODevice::WriteOnly);
 
     stream << level << QString::fromLocal8Bit(msg);
 
     Q_EMIT remoteSignal(DebugMessage, m_currentAction, blob);
 }
 
 void DBusHelperProxy::sendProgressStep(int step)
 {
     QByteArray blob;
     QDataStream stream(&blob, QIODevice::WriteOnly);
 
     stream << step;
 
     Q_EMIT remoteSignal(ProgressStepIndicator, m_currentAction, blob);
 }
 
 void DBusHelperProxy::sendProgressStepData(const QVariantMap &data)
 {
     QByteArray blob;
     QDataStream stream(&blob, QIODevice::WriteOnly);
 
     stream << data;
 
     Q_EMIT remoteSignal(ProgressStepData, m_currentAction, blob);
 }
 
 void debugMessageReceived(int t, const QString &message)
 {
     QtMsgType type = static_cast<QtMsgType>(t);
     switch (type) {
     case QtDebugMsg:
         qDebug("Debug message from helper: %s", message.toLatin1().data());
         break;
     case QtInfoMsg:
         qInfo("Info message from helper: %s", message.toLatin1().data());
         break;
     case QtWarningMsg:
         qWarning("Warning from helper: %s", message.toLatin1().data());
         break;
     case QtCriticalMsg:
         qCritical("Critical warning from helper: %s", message.toLatin1().data());
         break;
     case QtFatalMsg:
         qFatal("Fatal error from helper: %s", message.toLatin1().data());
         break;
     }
 }
 
 int DBusHelperProxy::callerUid() const
 {
     QDBusConnectionInterface *iface = connection().interface();
     if (!iface) {
         return -1;
     }
     return iface->serviceUid(message().service());
 }
 
 } // namespace Auth
 
 #include "moc_DBusHelperProxy.cpp"