File indexing completed on 2024-05-19 05:32:51

 /*
     KWin - the KDE window manager
     This file is part of the KDE project.
 
     SPDX-FileCopyrightText: 2018 Roman Gilg <subdiff@gmail.com>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 #include "transfer.h"
 
 #include "databridge.h"
 #include "xwayland.h"
 
 #include "atoms.h"
 #include "wayland/datadevice.h"
 #include "wayland/datasource.h"
 #include "wayland/seat.h"
 #include "wayland_server.h"
 #include "window.h"
 #include "workspace.h"
 
 #include <xcb/xcb_event.h>
 #include <xcb/xfixes.h>
 
 #include <algorithm>
 #include <unistd.h>
 
 #include <xwayland_logging.h>
 
 namespace KWin
 {
 namespace Xwl
 {
 
 // in Bytes: equals 64KB
 static const uint32_t s_incrChunkSize = 63 * 1024;
 
 Transfer::Transfer(xcb_atom_t selection, qint32 fd, xcb_timestamp_t timestamp, QObject *parent)
     : QObject(parent)
     , m_atom(selection)
     , m_fd(fd)
     , m_timestamp(timestamp)
 {
 }
 
 void Transfer::createSocketNotifier(QSocketNotifier::Type type)
 {
     delete m_notifier;
     m_notifier = new QSocketNotifier(m_fd, type, this);
 }
 
 void Transfer::clearSocketNotifier()
 {
     delete m_notifier;
     m_notifier = nullptr;
 }
 
 void Transfer::timeout()
 {
     if (m_timeout) {
         endTransfer();
     }
     m_timeout = true;
 }
 
 void Transfer::endTransfer()
 {
     clearSocketNotifier();
     closeFd();
     Q_EMIT finished();
 }
 
 void Transfer::closeFd()
 {
     if (m_fd < 0) {
         return;
     }
     close(m_fd);
     m_fd = -1;
 }
 
 TransferWltoX::TransferWltoX(xcb_atom_t selection, xcb_selection_request_event_t *request,
                              qint32 fd, QObject *parent)
     : Transfer(selection, fd, 0, parent)
     , m_request(request)
 {
 }
 
 TransferWltoX::~TransferWltoX()
 {
     delete m_request;
     m_request = nullptr;
 }
 
 void TransferWltoX::startTransferFromSource()
 {
     createSocketNotifier(QSocketNotifier::Read);
     connect(socketNotifier(), &QSocketNotifier::activated, this, [this](int socket) {
         readWlSource();
     });
 }
 
 int TransferWltoX::flushSourceData()
 {
     Q_ASSERT(!m_chunks.isEmpty());
     xcb_connection_t *xcbConn = kwinApp()->x11Connection();
 
     xcb_change_property(xcbConn,
                         XCB_PROP_MODE_REPLACE,
                         m_request->requestor,
                         m_request->property,
                         m_request->target,
                         8,
                         m_chunks.first().first.size(),
                         m_chunks.first().first.data());
     xcb_flush(xcbConn);
 
     m_propertyIsSet = true;
     resetTimeout();
 
     const auto rm = m_chunks.takeFirst();
     return rm.first.size();
 }
 
 void TransferWltoX::startIncr()
 {
     Q_ASSERT(m_chunks.size() == 1);
 
     xcb_connection_t *xcbConn = kwinApp()->x11Connection();
 
     uint32_t mask[] = {XCB_EVENT_MASK_PROPERTY_CHANGE};
     xcb_change_window_attributes(xcbConn,
                                  m_request->requestor,
                                  XCB_CW_EVENT_MASK, mask);
 
     // spec says to make the available space larger
     const uint32_t chunkSpace = 1024 + s_incrChunkSize;
     xcb_change_property(xcbConn,
                         XCB_PROP_MODE_REPLACE,
                         m_request->requestor,
                         m_request->property,
                         atoms->incr,
                         32, 1, &chunkSpace);
     xcb_flush(xcbConn);
 
     setIncr(true);
     // first data will be flushed after the property has been deleted
     // again by the requestor
     m_flushPropertyOnDelete = true;
     m_propertyIsSet = true;
     Q_EMIT selectionNotify(m_request, true);
 }
 
 void TransferWltoX::readWlSource()
 {
     if (m_chunks.size() == 0 || m_chunks.last().second == s_incrChunkSize) {
         // append new chunk
         auto next = QPair<QByteArray, int>();
         next.first.resize(s_incrChunkSize);
         next.second = 0;
         m_chunks.append(next);
     }
 
     const auto oldLen = m_chunks.last().second;
     const auto avail = s_incrChunkSize - m_chunks.last().second;
     Q_ASSERT(avail > 0);
 
     ssize_t readLen = read(fd(), m_chunks.last().first.data() + oldLen, avail);
     if (readLen == -1) {
         qCWarning(KWIN_XWL) << "Error reading in Wl data.";
 
         // TODO: cleanup X side?
         endTransfer();
         return;
     }
     m_chunks.last().second = oldLen + readLen;
 
     if (readLen == 0) {
         // at the fd end - complete transfer now
         m_chunks.last().first.resize(m_chunks.last().second);
 
         if (incr()) {
             // incremental transfer is to be completed now
             m_flushPropertyOnDelete = true;
             if (!m_propertyIsSet) {
                 // flush if target's property is not set at the moment
                 flushSourceData();
             }
             clearSocketNotifier();
         } else {
             // non incremental transfer is to be completed now,
             // data can be transferred to X client via a single property set
             flushSourceData();
             Q_EMIT selectionNotify(m_request, true);
             endTransfer();
         }
     } else if (m_chunks.last().second == s_incrChunkSize) {
         // first chunk full, but not yet at fd end -> go incremental
         if (incr()) {
             m_flushPropertyOnDelete = true;
             if (!m_propertyIsSet) {
                 // flush if target's property is not set at the moment
                 flushSourceData();
             }
         } else {
             // starting incremental transfer
             startIncr();
         }
     }
     resetTimeout();
 }
 
 bool TransferWltoX::handlePropertyNotify(xcb_property_notify_event_t *event)
 {
     if (event->window == m_request->requestor) {
         if (event->state == XCB_PROPERTY_DELETE && event->atom == m_request->property) {
             handlePropertyDelete();
         }
         return true;
     }
     return false;
 }
 
 void TransferWltoX::handlePropertyDelete()
 {
     if (!incr()) {
         // non-incremental transfer: nothing to do
         return;
     }
     m_propertyIsSet = false;
 
     if (m_flushPropertyOnDelete) {
         if (!socketNotifier() && m_chunks.isEmpty()) {
             // transfer complete
             xcb_connection_t *xcbConn = kwinApp()->x11Connection();
 
             uint32_t mask[] = {0};
             xcb_change_window_attributes(xcbConn,
                                          m_request->requestor,
                                          XCB_CW_EVENT_MASK, mask);
 
             xcb_change_property(xcbConn,
                                 XCB_PROP_MODE_REPLACE,
                                 m_request->requestor,
                                 m_request->property,
                                 m_request->target,
                                 8, 0, nullptr);
             xcb_flush(xcbConn);
             m_flushPropertyOnDelete = false;
             endTransfer();
         } else if (!m_chunks.isEmpty()) {
             flushSourceData();
         }
     }
 }
 
 TransferXtoWl::TransferXtoWl(xcb_atom_t selection, xcb_atom_t target, qint32 fd,
                              xcb_timestamp_t timestamp, xcb_window_t parentWindow,
                              QObject *parent)
     : Transfer(selection, fd, timestamp, parent)
 {
     // create transfer window
     xcb_connection_t *xcbConn = kwinApp()->x11Connection();
     m_window = xcb_generate_id(xcbConn);
     const uint32_t values[] = {XCB_EVENT_MASK_SUBSTRUCTURE_NOTIFY | XCB_EVENT_MASK_PROPERTY_CHANGE};
     xcb_create_window(xcbConn,
                       XCB_COPY_FROM_PARENT,
                       m_window,
                       parentWindow,
                       0, 0,
                       10, 10,
                       0,
                       XCB_WINDOW_CLASS_INPUT_OUTPUT,
                       XCB_COPY_FROM_PARENT,
                       XCB_CW_EVENT_MASK,
                       values);
     // convert selection
     xcb_convert_selection(xcbConn,
                           m_window,
                           selection,
                           target,
                           atoms->wl_selection,
                           timestamp);
     xcb_flush(xcbConn);
 }
 
 TransferXtoWl::~TransferXtoWl()
 {
     xcb_connection_t *xcbConn = kwinApp()->x11Connection();
     xcb_destroy_window(xcbConn, m_window);
     xcb_flush(xcbConn);
 
     delete m_receiver;
     m_receiver = nullptr;
 }
 
 bool TransferXtoWl::handlePropertyNotify(xcb_property_notify_event_t *event)
 {
     if (event->window == m_window) {
         if (event->state == XCB_PROPERTY_NEW_VALUE && event->atom == atoms->wl_selection) {
             getIncrChunk();
         }
         return true;
     }
     return false;
 }
 
 bool TransferXtoWl::handleSelectionNotify(xcb_selection_notify_event_t *event)
 {
     if (event->requestor != m_window) {
         return false;
     }
     if (event->selection != atom()) {
         return false;
     }
     if (event->property == XCB_ATOM_NONE) {
         qCWarning(KWIN_XWL) << "Incoming X selection conversion failed";
         return true;
     }
     if (event->target == atoms->targets) {
         qCWarning(KWIN_XWL) << "Received targets too late";
         // TODO: or allow it?
         return true;
     }
     if (m_receiver) {
         // second selection notify element - misbehaving source
 
         // TODO: cancel this transfer?
         return true;
     }
 
     m_receiver = new DataReceiver;
 
     startTransfer();
     return true;
 }
 
 void TransferXtoWl::startTransfer()
 {
     xcb_connection_t *xcbConn = kwinApp()->x11Connection();
     auto cookie = xcb_get_property(xcbConn,
                                    1,
                                    m_window,
                                    atoms->wl_selection,
                                    XCB_GET_PROPERTY_TYPE_ANY,
                                    0,
                                    0x1fffffff);
 
     auto *reply = xcb_get_property_reply(xcbConn, cookie, nullptr);
     if (reply == nullptr) {
         qCWarning(KWIN_XWL) << "Can't get selection property.";
         endTransfer();
         return;
     }
 
     if (reply->type == atoms->incr) {
         setIncr(true);
         free(reply);
     } else {
         setIncr(false);
         // reply's ownership is transferred
         m_receiver->transferFromProperty(reply);
         dataSourceWrite();
     }
 }
 
 void TransferXtoWl::getIncrChunk()
 {
     if (!incr()) {
         // source tries to sent incrementally, but did not announce it before
         return;
     }
     if (!m_receiver) {
         // receive mechanism has not yet been setup
         return;
     }
     xcb_connection_t *xcbConn = kwinApp()->x11Connection();
 
     auto cookie = xcb_get_property(xcbConn,
                                    0,
                                    m_window,
                                    atoms->wl_selection,
                                    XCB_GET_PROPERTY_TYPE_ANY,
                                    0,
                                    0x1fffffff);
 
     auto *reply = xcb_get_property_reply(xcbConn, cookie, nullptr);
     if (!reply) {
         qCWarning(KWIN_XWL) << "Can't get selection property.";
         endTransfer();
         return;
     }
 
     if (xcb_get_property_value_length(reply) > 0) {
         // reply's ownership is transferred
         m_receiver->transferFromProperty(reply);
         dataSourceWrite();
     } else {
         // Transfer complete
         free(reply);
         endTransfer();
     }
 }
 
 DataReceiver::~DataReceiver()
 {
     if (m_propertyReply) {
         free(m_propertyReply);
         m_propertyReply = nullptr;
     }
 }
 
 void DataReceiver::transferFromProperty(xcb_get_property_reply_t *reply)
 {
     m_propertyStart = 0;
     m_propertyReply = reply;
 
     setData(static_cast<char *>(xcb_get_property_value(reply)),
             xcb_get_property_value_length(reply));
 }
 
 void DataReceiver::setData(const char *value, int length)
 {
     // simply set data without copy
     m_data = QByteArray::fromRawData(value, length);
 }
 
 QByteArray DataReceiver::data() const
 {
     return QByteArray::fromRawData(m_data.data() + m_propertyStart,
                                    m_data.size() - m_propertyStart);
 }
 
 void DataReceiver::partRead(int length)
 {
     m_propertyStart += length;
     if (m_propertyStart == m_data.size()) {
         Q_ASSERT(m_propertyReply);
         free(m_propertyReply);
         m_propertyReply = nullptr;
     }
 }
 
 void TransferXtoWl::dataSourceWrite()
 {
     QByteArray property = m_receiver->data();
 
     ssize_t len = write(fd(), property.constData(), property.size());
     if (len == -1) {
         qCWarning(KWIN_XWL) << "X11 to Wayland write error on fd:" << fd();
         endTransfer();
         return;
     }
 
     m_receiver->partRead(len);
     if (len == property.size()) {
         // property completely transferred
         if (incr()) {
             clearSocketNotifier();
             xcb_connection_t *xcbConn = kwinApp()->x11Connection();
             xcb_delete_property(xcbConn,
                                 m_window,
                                 atoms->wl_selection);
             xcb_flush(xcbConn);
         } else {
             // transfer complete
             endTransfer();
         }
     } else {
         if (!socketNotifier()) {
             createSocketNotifier(QSocketNotifier::Write);
             connect(socketNotifier(), &QSocketNotifier::activated, this, [this](int socket) {
                 dataSourceWrite();
             });
         }
     }
     resetTimeout();
 }
 
 } // namespace Xwl
 } // namespace KWin
 
 #include "moc_transfer.cpp"