File indexing completed on 2025-03-16 11:21:58

 /*
     KWin - the KDE window manager
     This file is part of the KDE project.
 
     SPDX-FileCopyrightText: 2014 Martin Gräßlin <mgraesslin@kde.org>
     SPDX-FileCopyrightText: 2019 Roman Gilg <subdiff@gmail.com>
     SPDX-FileCopyrightText: 2020 Vlad Zahorodnii <vlad.zahorodnii@kde.org>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 #include "xwayland.h"
 
 #include <config-kwin.h>
 
 #include "databridge.h"
 #include "dnd.h"
 #include "window.h"
 #include "xwaylandlauncher.h"
 #include "xwldrophandler.h"
 
 #include "core/output.h"
 #include "input_event_spy.h"
 #include "keyboard_input.h"
 #include "main_wayland.h"
 #include "utils/common.h"
 #include "utils/xcbutils.h"
 #include "wayland_server.h"
 #include "waylandwindow.h"
 #include "workspace.h"
 #include "x11eventfilter.h"
 #include "xkb.h"
 #include "xwayland_logging.h"
 
 #include <KSelectionOwner>
 #include <wayland/keyboard_interface.h>
 #include <wayland/seat_interface.h>
 #include <wayland/surface_interface.h>
 
 #include <QAbstractEventDispatcher>
 #include <QDataStream>
 #include <QFile>
 #include <QHostInfo>
 #include <QRandomGenerator>
 #include <QScopeGuard>
 #include <QSocketNotifier>
 #include <QTimer>
 #include <QtConcurrentRun>
 
 #include <cerrno>
 #include <cstring>
 #include <input_event.h>
 #include <sys/socket.h>
 #include <unistd.h>
 #include <xkbcommon/xkbcommon-keysyms.h>
 
 namespace KWin
 {
 namespace Xwl
 {
 
 class XrandrEventFilter : public X11EventFilter
 {
 public:
     explicit XrandrEventFilter(Xwayland *backend);
 
     bool event(xcb_generic_event_t *event) override;
 
 private:
     Xwayland *const m_backend;
 };
 
 XrandrEventFilter::XrandrEventFilter(Xwayland *backend)
     : X11EventFilter(Xcb::Extensions::self()->randrNotifyEvent())
     , m_backend(backend)
 {
 }
 
 bool XrandrEventFilter::event(xcb_generic_event_t *event)
 {
     Q_ASSERT((event->response_type & ~0x80) == Xcb::Extensions::self()->randrNotifyEvent());
     m_backend->updatePrimary();
     return false;
 }
 
 class XwaylandInputSpy : public QObject, public KWin::InputEventSpy
 {
 public:
     XwaylandInputSpy()
     {
         connect(waylandServer()->seat(), &KWaylandServer::SeatInterface::focusedKeyboardSurfaceAboutToChange,
                 this, [this](KWaylandServer::SurfaceInterface *newSurface) {
                     auto keyboard = waylandServer()->seat()->keyboard();
                     if (!newSurface) {
                         return;
                     }
 
                     if (waylandServer()->xWaylandConnection() == newSurface->client()) {
                         // Since this is a spy but the keyboard interface gets its normal sendKey calls through filters,
                         // there can be a mismatch in both states.
                         // This loop makes sure all key press events are reset before we switch back to the
                         // Xwayland client and the state is correctly restored.
                         for (auto it = m_states.constBegin(); it != m_states.constEnd(); ++it) {
                             if (it.value() == KWaylandServer::KeyboardKeyState::Pressed) {
                                 keyboard->sendKey(it.key(), KWaylandServer::KeyboardKeyState::Released, waylandServer()->xWaylandConnection());
                             }
                         }
                         m_states.clear();
                     }
                 });
     }
 
     void setMode(XwaylandEavesdropsMode mode)
     {
         static const QSet<quint32> modifierKeys = {
             Qt::Key_Control,
             Qt::Key_Shift,
             Qt::Key_Alt,
             Qt::Key_Meta,
         };
 
         switch (mode) {
         case None:
             m_filter = {};
             break;
         case Modifiers:
             m_filter = [](int key, Qt::KeyboardModifiers) {
                 return modifierKeys.contains(key);
             };
             break;
         case Combinations:
             m_filter = [](int key, Qt::KeyboardModifiers m) {
                 return m != Qt::NoModifier || modifierKeys.contains(key);
             };
             break;
         case All:
             m_filter = [](int, Qt::KeyboardModifiers) {
                 return true;
             };
             break;
         }
     }
 
     void keyEvent(KWin::KeyEvent *event) override
     {
         if (event->isAutoRepeat()) {
             return;
         }
 
         Window *window = workspace()->activeWindow();
         if (!m_filter || !m_filter(event->key(), event->modifiers()) || (window && window->isLockScreen())) {
             return;
         }
 
         auto keyboard = waylandServer()->seat()->keyboard();
         auto surface = keyboard->focusedSurface();
         if (!surface) {
             return;
         }
 
         auto client = surface->client();
         if (waylandServer()->xWaylandConnection() != client) {
             KWaylandServer::KeyboardKeyState state{event->type() == QEvent::KeyPress};
             if (!updateKey(event->nativeScanCode(), state)) {
                 return;
             }
 
             auto xkb = input()->keyboard()->xkb();
             keyboard->sendModifiers(xkb->modifierState().depressed,
                                     xkb->modifierState().latched,
                                     xkb->modifierState().locked,
                                     xkb->currentLayout());
 
             waylandServer()->seat()->keyboard()->sendKey(event->nativeScanCode(), state, waylandServer()->xWaylandConnection());
         }
     }
 
     bool updateKey(quint32 key, KWaylandServer::KeyboardKeyState state)
     {
         auto it = m_states.find(key);
         if (it == m_states.end()) {
             m_states.insert(key, state);
             return true;
         }
         if (it.value() == state) {
             return false;
         }
         it.value() = state;
         return true;
     }
 
     QHash<quint32, KWaylandServer::KeyboardKeyState> m_states;
     std::function<bool(int key, Qt::KeyboardModifiers)> m_filter;
 };
 
 Xwayland::Xwayland(Application *app)
     : m_app(app)
     , m_launcher(new XwaylandLauncher(this))
 {
     connect(m_launcher, &XwaylandLauncher::started, this, &Xwayland::handleXwaylandReady);
     connect(m_launcher, &XwaylandLauncher::finished, this, &Xwayland::handleXwaylandFinished);
     connect(m_launcher, &XwaylandLauncher::errorOccurred, this, &Xwayland::errorOccurred);
 }
 
 Xwayland::~Xwayland()
 {
     m_launcher->stop();
 }
 
 void Xwayland::start()
 {
     m_launcher->start();
 }
 
 XwaylandLauncher *Xwayland::xwaylandLauncher() const
 {
     return m_launcher;
 }
 
 void Xwayland::dispatchEvents(DispatchEventsMode mode)
 {
     xcb_connection_t *connection = kwinApp()->x11Connection();
     if (!connection) {
         qCWarning(KWIN_XWL, "Attempting to dispatch X11 events with no connection");
         return;
     }
 
     const int connectionError = xcb_connection_has_error(connection);
     if (connectionError) {
         qCWarning(KWIN_XWL, "The X11 connection broke (error %d)", connectionError);
         m_launcher->stop();
         return;
     }
 
     auto pollEventFunc = mode == DispatchEventsMode::Poll ? xcb_poll_for_event : xcb_poll_for_queued_event;
 
     while (xcb_generic_event_t *event = pollEventFunc(connection)) {
 #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
         long result = 0;
 #else
         qintptr result = 0;
 #endif
 
         QAbstractEventDispatcher *dispatcher = QCoreApplication::eventDispatcher();
         dispatcher->filterNativeEvent(QByteArrayLiteral("xcb_generic_event_t"), event, &result);
         free(event);
     }
 
     xcb_flush(connection);
 }
 
 void Xwayland::installSocketNotifier()
 {
     const int fileDescriptor = xcb_get_file_descriptor(kwinApp()->x11Connection());
 
     m_socketNotifier = new QSocketNotifier(fileDescriptor, QSocketNotifier::Read, this);
     connect(m_socketNotifier, &QSocketNotifier::activated, this, [this]() {
         dispatchEvents(DispatchEventsMode::Poll);
     });
 
     QAbstractEventDispatcher *dispatcher = QCoreApplication::eventDispatcher();
     connect(dispatcher, &QAbstractEventDispatcher::aboutToBlock, this, [this]() {
         dispatchEvents(DispatchEventsMode::EventQueue);
     });
     connect(dispatcher, &QAbstractEventDispatcher::awake, this, [this]() {
         dispatchEvents(DispatchEventsMode::EventQueue);
     });
 }
 
 void Xwayland::uninstallSocketNotifier()
 {
     QAbstractEventDispatcher *dispatcher = QCoreApplication::eventDispatcher();
     disconnect(dispatcher, nullptr, this, nullptr);
 
     delete m_socketNotifier;
     m_socketNotifier = nullptr;
 }
 
 void Xwayland::handleXwaylandFinished()
 {
     disconnect(workspace(), &Workspace::outputOrderChanged, this, &Xwayland::updatePrimary);
 
     delete m_xrandrEventsFilter;
     m_xrandrEventsFilter = nullptr;
 
     // If Xwayland has crashed, we must deactivate the socket notifier and ensure that no X11
     // events will be dispatched before blocking; otherwise we will simply hang...
     uninstallSocketNotifier();
 
     m_dataBridge.reset();
     m_selectionOwner.reset();
 
     destroyX11Connection();
 }
 
 void Xwayland::handleXwaylandReady()
 {
     if (!createX11Connection()) {
         Q_EMIT errorOccurred();
         return;
     }
 
     qCInfo(KWIN_XWL) << "Xwayland server started on display" << m_launcher->displayName();
 
     // create selection owner for WM_S0 - magic X display number expected by XWayland
     m_selectionOwner.reset(new KSelectionOwner("WM_S0", kwinApp()->x11Connection(), kwinApp()->x11RootWindow()));
     connect(m_selectionOwner.get(), &KSelectionOwner::lostOwnership,
             this, &Xwayland::handleSelectionLostOwnership);
     connect(m_selectionOwner.get(), &KSelectionOwner::claimedOwnership,
             this, &Xwayland::handleSelectionClaimedOwnership);
     connect(m_selectionOwner.get(), &KSelectionOwner::failedToClaimOwnership,
             this, &Xwayland::handleSelectionFailedToClaimOwnership);
     m_selectionOwner->claim(true);
 
     m_dataBridge = std::make_unique<DataBridge>();
 
     auto env = m_app->processStartupEnvironment();
     env.insert(QStringLiteral("DISPLAY"), m_launcher->displayName());
     env.insert(QStringLiteral("XAUTHORITY"), m_launcher->xauthority());
     qputenv("DISPLAY", m_launcher->displayName().toLatin1());
     qputenv("XAUTHORITY", m_launcher->xauthority().toLatin1());
     m_app->setProcessStartupEnvironment(env);
 
     connect(workspace(), &Workspace::outputOrderChanged, this, &Xwayland::updatePrimary);
     updatePrimary();
 
     Xcb::sync(); // Trigger possible errors, there's still a chance to abort
 
     delete m_xrandrEventsFilter;
     m_xrandrEventsFilter = new XrandrEventFilter(this);
 
     refreshEavesdropping();
     connect(options, &Options::xwaylandEavesdropsChanged, this, &Xwayland::refreshEavesdropping);
 }
 
 void Xwayland::refreshEavesdropping()
 {
     if (!waylandServer()->seat()->keyboard()) {
         return;
     }
 
     const bool enabled = options->xwaylandEavesdrops() != None;
     if (enabled == bool(m_inputSpy)) {
         if (m_inputSpy) {
             m_inputSpy->setMode(options->xwaylandEavesdrops());
         }
         return;
     }
 
     if (enabled) {
         m_inputSpy.reset(new XwaylandInputSpy);
         input()->installInputEventSpy(m_inputSpy.get());
         m_inputSpy->setMode(options->xwaylandEavesdrops());
     } else {
         input()->uninstallInputEventSpy(m_inputSpy.get());
         m_inputSpy.reset();
     }
 }
 
 void Xwayland::updatePrimary()
 {
     if (workspace()->outputOrder().empty()) {
         return;
     }
     Xcb::RandR::ScreenResources resources(kwinApp()->x11RootWindow());
     xcb_randr_crtc_t *crtcs = resources.crtcs();
     if (!crtcs) {
         return;
     }
 
     Output *const primaryOutput = workspace()->outputOrder().front();
     for (int i = 0; i < resources->num_crtcs; ++i) {
         Xcb::RandR::CrtcInfo crtcInfo(crtcs[i], resources->config_timestamp);
         const QRect geometry = crtcInfo.rect();
         if (geometry.topLeft() == primaryOutput->geometry().topLeft()) {
             auto outputs = crtcInfo.outputs();
             if (outputs && crtcInfo->num_outputs > 0) {
                 qCDebug(KWIN_XWL) << "Setting primary" << primaryOutput << outputs[0];
                 xcb_randr_set_output_primary(kwinApp()->x11Connection(), kwinApp()->x11RootWindow(), outputs[0]);
                 break;
             }
         }
     }
 }
 
 void Xwayland::handleSelectionLostOwnership()
 {
     qCWarning(KWIN_XWL) << "Somebody else claimed ownership of WM_S0. This should never happen!";
     m_launcher->stop();
 }
 
 void Xwayland::handleSelectionFailedToClaimOwnership()
 {
     qCWarning(KWIN_XWL) << "Failed to claim ownership of WM_S0. This should never happen!";
     m_launcher->stop();
 }
 
 void Xwayland::handleSelectionClaimedOwnership()
 {
     Q_EMIT started();
 }
 
 bool Xwayland::createX11Connection()
 {
     xcb_connection_t *connection = xcb_connect_to_fd(m_launcher->xcbConnectionFd(), nullptr);
 
     const int errorCode = xcb_connection_has_error(connection);
     if (errorCode) {
         qCDebug(KWIN_XWL, "Failed to establish the XCB connection (error %d)", errorCode);
         return false;
     }
 
     xcb_screen_t *screen = xcb_setup_roots_iterator(xcb_get_setup(connection)).data;
     Q_ASSERT(screen);
 
     m_app->setX11Connection(connection);
     m_app->setX11RootWindow(screen->root);
 
     m_app->createAtoms();
     m_app->installNativeX11EventFilter();
 
     installSocketNotifier();
 
     // Note that it's very important to have valid x11RootWindow(), and atoms when the
     // rest of kwin is notified about the new X11 connection.
     Q_EMIT m_app->x11ConnectionChanged();
 
     return true;
 }
 
 void Xwayland::destroyX11Connection()
 {
     if (!m_app->x11Connection()) {
         return;
     }
 
     Q_EMIT m_app->x11ConnectionAboutToBeDestroyed();
 
     Xcb::setInputFocus(XCB_INPUT_FOCUS_POINTER_ROOT);
     m_app->destroyAtoms();
     m_app->removeNativeX11EventFilter();
 
     xcb_disconnect(m_app->x11Connection());
 
     m_app->setX11Connection(nullptr);
     m_app->setX11RootWindow(XCB_WINDOW_NONE);
 
     Q_EMIT m_app->x11ConnectionChanged();
 }
 
 DragEventReply Xwayland::dragMoveFilter(Window *target, const QPoint &pos)
 {
     if (m_dataBridge) {
         return m_dataBridge->dragMoveFilter(target, pos);
     } else {
         return DragEventReply::Wayland;
     }
 }
 
 KWaylandServer::AbstractDropHandler *Xwayland::xwlDropHandler()
 {
     if (m_dataBridge) {
         return m_dataBridge->dnd()->dropHandler();
     } else {
         return nullptr;
     }
 }
 
 } // namespace Xwl
 } // namespace KWin