File indexing completed on 2024-05-12 09:01:26

 /* This file is part of the KDE project
    Copyright (C) 2018-2021 Jan Grulich <jgrulich@redhat.com>
    Copyright (C) 2018 Oleg Chernovskiy <kanedias@xaker.ru>
 
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public
    License as published by the Free Software Foundation; either
    version 3 of the License, or (at your option) any later version.
 */
 
 #include "config-krfb.h"
 
 // system
 #include <sys/mman.h>
 #include <cstring>
 
 // Qt
 #include <QCoreApplication>
 #include <QGuiApplication>
 #include <QScreen>
 #include <QSocketNotifier>
 #include <QDebug>
 #include <QRandomGenerator>
 
 #include <KWayland/Client/connection_thread.h>
 #include <KWayland/Client/registry.h>
 
 // pipewire
 #include <climits>
 
 #include "pw_framebuffer.h"
 #include "xdp_dbus_screencast_interface.h"
 #include "xdp_dbus_remotedesktop_interface.h"
 #include "krfb_fb_pipewire_debug.h"
 #include "screencasting.h"
 #include <PipeWireSourceStream>
 #include <kpipewire_version.h>
 #include <DmaBufHandler>
 
 static const int BYTES_PER_PIXEL = 4;
 static const uint MIN_SUPPORTED_XDP_KDE_SC_VERSION = 1;
 
 Q_DECLARE_METATYPE(PWFrameBuffer::Stream);
 Q_DECLARE_METATYPE(PWFrameBuffer::Streams);
 
 const QDBusArgument &operator >> (const QDBusArgument &arg, PWFrameBuffer::Stream &stream)
 {
     arg.beginStructure();
     arg >> stream.nodeId;
 
     arg.beginMap();
     while (!arg.atEnd()) {
         QString key;
         QVariant map;
         arg.beginMapEntry();
         arg >> key >> map;
         arg.endMapEntry();
         stream.map.insert(key, map);
     }
     arg.endMap();
     arg.endStructure();
 
     return arg;
 }
 
 /**
  * @brief The PWFrameBuffer::Private class - private counterpart of PWFramebuffer class. This is the entity where
  *        whole logic resides, for more info search for "d-pointer pattern" information.
  */
 class PWFrameBuffer::Private {
 public:
     Private(PWFrameBuffer *q);
     ~Private();
 
 private:
     friend class PWFrameBuffer;
 
     void initDbus();
 
     // dbus handling
     void handleSessionCreated(quint32 code, const QVariantMap &results);
     void handleDevicesSelected(quint32 code, const QVariantMap &results);
     void handleSourcesSelected(quint32 code, const QVariantMap &results);
     void handleRemoteDesktopStarted(quint32 code, const QVariantMap &results);
     void setVideoSize(const QSize &size);
 
     // pw handling
     void handleFrame(const PipeWireFrame &frame);
 
     // link to public interface
     PWFrameBuffer *q;
 
     // requests a session from XDG Desktop Portal
     // auto-generated and compiled from xdp_dbus_interface.xml file
     QScopedPointer<OrgFreedesktopPortalScreenCastInterface> dbusXdpScreenCastService;
     QScopedPointer<OrgFreedesktopPortalRemoteDesktopInterface> dbusXdpRemoteDesktopService;
 
     // XDP screencast session handle
     QDBusObjectPath sessionPath;
 
     // screen geometry holder
     QSize videoSize;
 
     // sanity indicator
     bool isValid = true;
     std::unique_ptr<PipeWireSourceStream> stream;
     std::optional<PipeWireCursor> cursor;
     DmaBufHandler m_dmabufHandler;
 };
 
 PWFrameBuffer::Private::Private(PWFrameBuffer *q)
     : q(q)
     , stream(new PipeWireSourceStream(q))
 {
     QObject::connect(stream.get(), &PipeWireSourceStream::frameReceived, q, [this] (const PipeWireFrame &frame) {
         handleFrame(frame);
     });
 }
 
 /**
  * @brief PWFrameBuffer::Private::initDbus - initialize D-Bus connectivity with XDG Desktop Portal.
  *        Based on XDG_CURRENT_DESKTOP environment variable it will give us implementation that we need,
  *        in case of KDE it is xdg-desktop-portal-kde binary.
  */
 void PWFrameBuffer::Private::initDbus()
 {
     qInfo() << "Initializing D-Bus connectivity with XDG Desktop Portal";
     dbusXdpScreenCastService.reset(new OrgFreedesktopPortalScreenCastInterface(QStringLiteral("org.freedesktop.portal.Desktop"),
                                                                      QStringLiteral("/org/freedesktop/portal/desktop"),
                                                                      QDBusConnection::sessionBus()));
     dbusXdpRemoteDesktopService.reset(new OrgFreedesktopPortalRemoteDesktopInterface(QStringLiteral("org.freedesktop.portal.Desktop"),
                                                                      QStringLiteral("/org/freedesktop/portal/desktop"),
                                                                      QDBusConnection::sessionBus()));
     auto version = dbusXdpScreenCastService->version();
     if (version < MIN_SUPPORTED_XDP_KDE_SC_VERSION) {
         qCWarning(KRFB_FB_PIPEWIRE) << "Unsupported XDG Portal screencast interface version:" << version;
         isValid = false;
         return;
     }
 
     // create session
     auto sessionParameters = QVariantMap {
         { QStringLiteral("session_handle_token"), QStringLiteral("krfb%1").arg(QRandomGenerator::global()->generate()) },
         { QStringLiteral("handle_token"), QStringLiteral("krfb%1").arg(QRandomGenerator::global()->generate()) }
     };
     auto sessionReply = dbusXdpRemoteDesktopService->CreateSession(sessionParameters);
     sessionReply.waitForFinished();
     if (!sessionReply.isValid()) {
         qWarning("Couldn't initialize XDP-KDE screencast session");
         isValid = false;
         return;
     }
 
     qInfo() << "DBus session created: " << sessionReply.value().path();
     QDBusConnection::sessionBus().connect(QString(),
                                           sessionReply.value().path(),
                                           QStringLiteral("org.freedesktop.portal.Request"),
                                           QStringLiteral("Response"),
                                           this->q,
                                           SLOT(handleXdpSessionCreated(uint, QVariantMap)));
 }
 
 void PWFrameBuffer::handleXdpSessionCreated(quint32 code, const QVariantMap &results)
 {
     d->handleSessionCreated(code, results);
 }
 
 /**
  * @brief PWFrameBuffer::Private::handleSessionCreated - handle creation of ScreenCast session.
  *        XDG Portal answers with session path if it was able to successfully create the screencast.
  *
  * @param code return code for dbus call. Zero is success, non-zero means error
  * @param results map with results of call.
  */
 void PWFrameBuffer::Private::handleSessionCreated(quint32 code, const QVariantMap &results)
 {
     if (code != 0) {
         qCWarning(KRFB_FB_PIPEWIRE) << "Failed to create session: " << code;
         isValid = false;
         return;
     }
 
     sessionPath = QDBusObjectPath(results.value(QStringLiteral("session_handle")).toString());
 
     // select sources for the session
     auto selectionOptions = QVariantMap {
         // We have to specify it's an uint, otherwise xdg-desktop-portal will not forward it to backend implementation
         { QStringLiteral("types"), QVariant::fromValue<uint>(7) }, // request all (KeyBoard, Pointer, TouchScreen)
         { QStringLiteral("handle_token"), QStringLiteral("krfb%1").arg(QRandomGenerator::global()->generate()) }
     };
     auto selectorReply = dbusXdpRemoteDesktopService->SelectDevices(sessionPath, selectionOptions);
     selectorReply.waitForFinished();
     if (!selectorReply.isValid()) {
         qCWarning(KRFB_FB_PIPEWIRE) << "Couldn't select devices for the remote-desktop session";
         isValid = false;
         return;
     }
     QDBusConnection::sessionBus().connect(QString(),
                                           selectorReply.value().path(),
                                           QStringLiteral("org.freedesktop.portal.Request"),
                                           QStringLiteral("Response"),
                                           this->q,
                                           SLOT(handleXdpDevicesSelected(uint, QVariantMap)));
 }
 
 void PWFrameBuffer::handleXdpDevicesSelected(quint32 code, const QVariantMap &results)
 {
     d->handleDevicesSelected(code, results);
 }
 
 /**
  * @brief PWFrameBuffer::Private::handleDevicesCreated - handle selection of devices we want to use for remote desktop
  *
  * @param code return code for dbus call. Zero is success, non-zero means error
  * @param results map with results of call.
  */
 void PWFrameBuffer::Private::handleDevicesSelected(quint32 code, const QVariantMap &results)
 {
     Q_UNUSED(results)
     if (code != 0) {
         qCWarning(KRFB_FB_PIPEWIRE) << "Failed to select devices: " << code;
         isValid = false;
         return;
     }
 
     // select sources for the session
     auto selectionOptions = QVariantMap {
         { QStringLiteral("types"), QVariant::fromValue<uint>(1) }, // only MONITOR is supported
         { QStringLiteral("multiple"), false },
         { QStringLiteral("handle_token"), QStringLiteral("krfb%1").arg(QRandomGenerator::global()->generate()) }
     };
     auto selectorReply = dbusXdpScreenCastService->SelectSources(sessionPath, selectionOptions);
     selectorReply.waitForFinished();
     if (!selectorReply.isValid()) {
         qCWarning(KRFB_FB_PIPEWIRE) << "Couldn't select sources for the screen-casting session";
         isValid = false;
         return;
     }
     QDBusConnection::sessionBus().connect(QString(),
                                           selectorReply.value().path(),
                                           QStringLiteral("org.freedesktop.portal.Request"),
                                           QStringLiteral("Response"),
                                           this->q,
                                           SLOT(handleXdpSourcesSelected(uint, QVariantMap)));
 }
 
 void PWFrameBuffer::handleXdpSourcesSelected(quint32 code, const QVariantMap &results)
 {
     d->handleSourcesSelected(code, results);
 }
 
 /**
  * @brief PWFrameBuffer::Private::handleSourcesSelected - handle Screencast sources selection.
  *        XDG Portal shows a dialog at this point which allows you to select monitor from the list.
  *        This function is called after you make a selection.
  *
  * @param code return code for dbus call. Zero is success, non-zero means error
  * @param results map with results of call.
  */
 void PWFrameBuffer::Private::handleSourcesSelected(quint32 code, const QVariantMap &)
 {
     if (code != 0) {
         qCWarning(KRFB_FB_PIPEWIRE) << "Failed to select sources: " << code;
         isValid = false;
         return;
     }
 
     // start session
     auto startParameters = QVariantMap {
         { QStringLiteral("handle_token"), QStringLiteral("krfb%1").arg(QRandomGenerator::global()->generate()) }
     };
     auto startReply = dbusXdpRemoteDesktopService->Start(sessionPath, QString(), startParameters);
     startReply.waitForFinished();
     QDBusConnection::sessionBus().connect(QString(),
                                           startReply.value().path(),
                                           QStringLiteral("org.freedesktop.portal.Request"),
                                           QStringLiteral("Response"),
                                           this->q,
                                           SLOT(handleXdpRemoteDesktopStarted(uint, QVariantMap)));
 }
 
 
 void PWFrameBuffer::handleXdpRemoteDesktopStarted(quint32 code, const QVariantMap &results)
 {
     d->handleRemoteDesktopStarted(code, results);
 }
 
 /**
  * @brief PWFrameBuffer::Private::handleScreencastStarted - handle Screencast start.
  *        At this point there shall be ready pipewire stream to consume.
  *
  * @param code return code for dbus call. Zero is success, non-zero means error
  * @param results map with results of call.
  */
 void PWFrameBuffer::Private::handleRemoteDesktopStarted(quint32 code, const QVariantMap &results)
 {
     if (code != 0) {
         qCWarning(KRFB_FB_PIPEWIRE) << "Failed to start screencast: " << code;
         isValid = false;
         return;
     }
 
     if (results.value(QStringLiteral("devices")).toUInt() == 0) {
         qCWarning(KRFB_FB_PIPEWIRE) << "No devices were granted" << results;
         isValid = false;
         return;
     }
 
     // there should be only one stream
     const Streams streams = qdbus_cast<Streams>(results.value(QStringLiteral("streams")));
     if (streams.isEmpty()) {
         // maybe we should check deeper with qdbus_cast but this suffices for now
         qCWarning(KRFB_FB_PIPEWIRE) << "Failed to get screencast streams";
         isValid = false;
         return;
     }
 
     auto streamReply = dbusXdpScreenCastService->OpenPipeWireRemote(sessionPath, QVariantMap());
     streamReply.waitForFinished();
     if (!streamReply.isValid()) {
         qCWarning(KRFB_FB_PIPEWIRE) << "Couldn't open pipewire remote for the screen-casting session";
         isValid = false;
         return;
     }
 
     QDBusUnixFileDescriptor pipewireFd = streamReply.value();
     if (!pipewireFd.isValid()) {
         qCWarning(KRFB_FB_PIPEWIRE) << "Couldn't get pipewire connection file descriptor";
         isValid = false;
         return;
     }
 
     if (!stream->createStream(streams.first().nodeId, pipewireFd.takeFileDescriptor())) {
         qCWarning(KRFB_FB_PIPEWIRE) << "Couldn't create the pipewire stream";
         isValid = false;
         return;
     }
     setVideoSize(qdbus_cast<QSize>(streams.first().map[QStringLiteral("size")].value<QDBusArgument>()));
 }
 
 void PWFrameBuffer::Private::handleFrame(const PipeWireFrame &frame)
 {
     cursor = frame.cursor;
 
 #if KPIPEWIRE_VERSION < QT_VERSION_CHECK(6, 0, 70)
     if (!frame.dmabuf && !frame.image) {
 #else
     if (!frame.dmabuf && !frame.dataFrame) {
 #endif
         qCDebug(KRFB_FB_PIPEWIRE) << "Got empty buffer. The buffer possibly carried only "
                                      "information about the mouse cursor.";
         return;
     }
 
 #if KPIPEWIRE_VERSION < QT_VERSION_CHECK(6, 0, 70)
     if (frame.image) {
         memcpy(q->fb, frame.image->constBits(), frame.image->sizeInBytes());
         setVideoSize(frame.image->size());
     }
 #else
     if (frame.dataFrame) {
         memcpy(q->fb, frame.dataFrame->data, frame.dataFrame->size.width() * frame.dataFrame->stride);
         setVideoSize(frame.dataFrame->size);
     }
 #endif
     else if (frame.dmabuf) {
         QImage src((uchar*) q->fb, videoSize.width(), videoSize.height(), QImage::Format_RGB32);
         if (!m_dmabufHandler.downloadFrame(src, frame)) {
             stream->renegotiateModifierFailed(frame.format, frame.dmabuf->modifier);
             qCDebug(KRFB_FB_PIPEWIRE) << "Failed to download frame.";
             return;
         }
         setVideoSize(src.size());
     } else {
         qCDebug(KRFB_FB_PIPEWIRE) << "Unknown kind of frame";
     }
 
     if (auto damage = frame.damage) {
         for (const auto &rect : *damage) {
             q->tiles.append(rect);
         }
     } else {
         q->tiles.append(QRect(0, 0, videoSize.width(), videoSize.height()));
     }
 }
 
 void PWFrameBuffer::Private::setVideoSize(const QSize &size)
 {
     if (q->fb && videoSize == size) {
         return;
     }
 
     free(q->fb);
     q->fb = static_cast<char*>(malloc(size.width() * size.height() * BYTES_PER_PIXEL));
     if (!q->fb) {
         qCWarning(KRFB_FB_PIPEWIRE) << "Failed to allocate buffer";
         isValid = false;
         return;
     }
     videoSize = size;
 
     Q_EMIT q->frameBufferChanged();
 }
 
 PWFrameBuffer::Private::~Private()
 {
 }
 
 PWFrameBuffer::PWFrameBuffer(QObject *parent)
     : FrameBuffer (parent),
       d(new Private(this))
 {
 }
 
 PWFrameBuffer::~PWFrameBuffer()
 {
     free(fb);
     fb = nullptr;
 }
 
 void PWFrameBuffer::initDBus()
 {
     d->initDbus();
 }
 
 void PWFrameBuffer::startVirtualMonitor(const QString& name, const QSize& resolution, qreal dpr)
 {
     d->videoSize = resolution * dpr;
     using namespace KWayland::Client;
     auto connection = ConnectionThread::fromApplication(this);
     if (!connection) {
         qWarning() << "Failed getting Wayland connection from QPA";
         QCoreApplication::exit(1);
         return;
     }
 
     auto registry = new Registry(this);
     connect(registry, &KWayland::Client::Registry::interfaceAnnounced, this, [this, registry, name, dpr, resolution] (const QByteArray &interfaceName, quint32 wlname, quint32 version) {
         if (interfaceName != "zkde_screencast_unstable_v1")
             return;
 
         auto screencasting = new Screencasting(registry, wlname, version, this);
         auto r = screencasting->createVirtualMonitorStream(name, resolution, dpr, Screencasting::Metadata);
         connect(r, &ScreencastingStream::created, this, [this] (quint32 nodeId) {
             d->stream->createStream(nodeId, 0);
         });
     });
     registry->create(connection);
     registry->setup();
 }
 
 int PWFrameBuffer::depth()
 {
     return 32;
 }
 
 int PWFrameBuffer::height()
 {
     if (!d->videoSize.isValid()) {
         return 0;
     }
     return d->videoSize.height();
 }
 
 int PWFrameBuffer::width()
 {
     if (!d->videoSize.isValid()) {
         return 0;
     }
     return d->videoSize.width();
 }
 
 int PWFrameBuffer::paddedWidth()
 {
     return width() * 4;
 }
 
 void PWFrameBuffer::getServerFormat(rfbPixelFormat &format)
 {
     format.bitsPerPixel = 32;
     format.depth = 32;
     format.trueColour = true;
     format.bigEndian = false;
 }
 
 void PWFrameBuffer::startMonitor()
 {
 
 }
 
 void PWFrameBuffer::stopMonitor()
 {
 
 }
 
 QVariant PWFrameBuffer::customProperty(const QString &property) const
 {
     if (property == QLatin1String("stream_node_id")) {
         return QVariant::fromValue<uint>(d->stream->nodeId());
     } if (property == QLatin1String("session_handle")) {
         return QVariant::fromValue<QDBusObjectPath>(d->sessionPath);
     }
 
     return FrameBuffer::customProperty(property);
 }
 
 bool PWFrameBuffer::isValid() const
 {
     return d->isValid;
 }
 
 QPoint PWFrameBuffer::cursorPosition()
 {
     return d->cursor->position;
 }