deskflow/src/lib/platform/PortalRemoteDesktop.cpp

/*
 * Deskflow -- mouse and keyboard sharing utility
 * SPDX-FileCopyrightText: (C) 2024 Symless Ltd.
 * SPDX-FileCopyrightText: (C) 2022 Red Hat, Inc.
 * SPDX-License-Identifier: GPL-2.0-only WITH LicenseRef-OpenSSL-Exception
 */

#include "platform/PortalRemoteDesktop.h"
#include "base/Log.h"
#include "base/TMethodJob.h"

#include <sys/socket.h> // for EIS fd hack, remove
#include <sys/un.h>     // for EIS fd hack, remove

namespace deskflow {

PortalRemoteDesktop::PortalRemoteDesktop(EiScreen *screen, IEventQueue *events)
    : screen_(screen),
      events_(events),
      portal_(xdp_portal_new())
{
  glib_main_loop_ = g_main_loop_new(nullptr, true);
  glib_thread_ = new Thread(new TMethodJob<PortalRemoteDesktop>(this, &PortalRemoteDesktop::glib_thread));

  reconnect(0);
}

PortalRemoteDesktop::~PortalRemoteDesktop()
{
  if (g_main_loop_is_running(glib_main_loop_))
    g_main_loop_quit(glib_main_loop_);

  if (glib_thread_ != nullptr) {
    glib_thread_->cancel();
    glib_thread_->wait();
    delete glib_thread_;
    glib_thread_ = nullptr;

    g_main_loop_unref(glib_main_loop_);
    glib_main_loop_ = nullptr;
  }

  if (session_signal_id_)
    g_signal_handler_disconnect(session_, session_signal_id_);
  if (session_ != nullptr)
    g_object_unref(session_);
  g_object_unref(portal_);

  free(session_restore_token_);
}

gboolean PortalRemoteDesktop::timeout_handler()
{
  return true; // keep re-triggering
}

void PortalRemoteDesktop::reconnect(unsigned int timeout)
{
  auto init_cb = [](gpointer data) -> gboolean {
    return reinterpret_cast<PortalRemoteDesktop *>(data)->init_remote_desktop_session();
  };

  if (timeout > 0)
    g_timeout_add(timeout, init_cb, this);
  else
    g_idle_add(init_cb, this);
}

void PortalRemoteDesktop::cb_session_closed(XdpSession *session)
{
  LOG_ERR("portal remote desktop session was closed, reconnecting");
  g_signal_handler_disconnect(session, session_signal_id_);
  session_signal_id_ = 0;
  events_->addEvent(Event(events_->forEi().sessionClosed(), screen_->getEventTarget()));

  // gcc warning "Suspicious usage of 'sizeof(A*)'" can be ignored
  g_clear_object(&session_);

  reconnect(1000);
}

void PortalRemoteDesktop::cb_session_started(GObject *object, GAsyncResult *res)
{
  g_autoptr(GError) error = nullptr;
  auto session = XDP_SESSION(object);
  auto success = xdp_session_start_finish(session, res, &error);
  if (!success) {
    LOG_ERR("failed to start portal remote desktop session, quitting: %s", error->message);
    g_main_loop_quit(glib_main_loop_);
    events_->addEvent(Event::kQuit);
    return;
  }

  session_restore_token_ = xdp_session_get_restore_token(session);

  // ConnectToEIS requires version 2 of the xdg-desktop-portal (and the same
  // version in the impl.portal), i.e. you'll need an updated compositor on
  // top of everything...
  auto fd = -1;
  fd = xdp_session_connect_to_eis(session, &error);
  if (fd < 0) {
    g_main_loop_quit(glib_main_loop_);
    events_->addEvent(Event::kQuit);
    return;
  }

  // Socket ownership is transferred to the EiScreen
  events_->addEvent(Event(events_->forEi().connected(), screen_->getEventTarget(), EiScreen::EiConnectInfo::alloc(fd)));
}

void PortalRemoteDesktop::cb_init_remote_desktop_session(GObject *object, GAsyncResult *res)
{
  LOG_DEBUG("portal remote desktop session initialized");
  g_autoptr(GError) error = nullptr;

  auto session = xdp_portal_create_remote_desktop_session_finish(XDP_PORTAL(object), res, &error);
  if (!session) {
    LOG_ERR("failed to initialize remote desktop session: %s", error->message);
    // This was the first attempt to connect to the RD portal - quit if that
    // fails.
    if (session_iteration_ == 0) {
      g_main_loop_quit(glib_main_loop_);
      events_->addEvent(Event::kQuit);
    } else {
      this->reconnect(1000);
    }
    return;
  }

  session_ = session;
  ++session_iteration_;

  // FIXME: the lambda trick doesn't work here for unknown reasons, we need
  // the static function
  session_signal_id_ = g_signal_connect(G_OBJECT(session), "closed", G_CALLBACK(cb_session_closed_cb), this);

  LOG_DEBUG("portal remote desktop session starting");
  xdp_session_start(
      session,
      nullptr, // parent
      nullptr, // cancellable
      [](GObject *obj, GAsyncResult *res, gpointer data) {
        reinterpret_cast<PortalRemoteDesktop *>(data)->cb_session_started(obj, res);
      },
      this
  );
}

gboolean PortalRemoteDesktop::init_remote_desktop_session()
{
  LOG_DEBUG("setting up remote desktop session with restore token %s", session_restore_token_);
  xdp_portal_create_remote_desktop_session_full(
      portal_, static_cast<XdpDeviceType>(XDP_DEVICE_POINTER | XDP_DEVICE_KEYBOARD), XDP_OUTPUT_NONE,
      XDP_REMOTE_DESKTOP_FLAG_NONE, XDP_CURSOR_MODE_HIDDEN, XDP_PERSIST_MODE_TRANSIENT, session_restore_token_,
      nullptr, // cancellable
      [](GObject *obj, GAsyncResult *res, gpointer data) {
        reinterpret_cast<PortalRemoteDesktop *>(data)->cb_init_remote_desktop_session(obj, res);
      },
      this
  );

  return false; // don't reschedule
}

void PortalRemoteDesktop::glib_thread(void *)
{
  auto context = g_main_loop_get_context(glib_main_loop_);

  while (g_main_loop_is_running(glib_main_loop_)) {
    Thread::testCancel();
    g_main_context_iteration(context, true);
  }
}

} // namespace deskflow