remote: support the ConnectToEIS method added in version 2

This is intended to replace the various NotifyFoo dbus methods and
instead connect the application with the implementation of the portal
directly via a shared socket.

libportal/remote.c

@@ -41,6 +41,68 @@ typedef struct {
   guint cancelled_id;
 } CreateCall;
 
+/**
+ * xdp_session_connect_to_eis
+ * @session: a [class@Session]
+ *
+ * Connect this XdpRemoteDesktopSession to an EIS implementation and return the fd.
+ * This fd can be passed into ei_setup_backend_fd(). See the libei
+ * documentation for details.
+ *
+ * This call must be issued before xdp_session_start(). If successful, all input
+ * event emulation must be handled via the EIS connection and calls to
+ * xdp_session_pointer_motion() etc. are silently ignored.
+ *
+ * Returns: the file descriptor to the EIS implementation or a negative errno
+ * on failure.
+ */
+int
+xdp_session_connect_to_eis(XdpSession *session)
+{
+  XdpPortal *portal = session->portal;
+  GVariantBuilder options;
+  g_autoptr(GVariant) ret = NULL;
+  g_autoptr(GError) error = NULL;
+  g_autoptr(GUnixFDList) fd_list = NULL;
+  int fd_out = -1;
+
+  g_return_val_if_fail (session->type == XDP_SESSION_REMOTE_DESKTOP, -EINVAL);
+  g_return_val_if_fail (xdp_session_get_session_state (session) == XDP_SESSION_INITIAL, -EBUSY);
+  g_return_val_if_fail (!session->uses_eis, -EALREADY);
+
+  if (portal->remote_desktop_interface_version < 2)
+    return -ENOTSUP;
+
+  g_variant_builder_init (&options, G_VARIANT_TYPE_VARDICT);
+
+  ret = g_dbus_connection_call_with_unix_fd_list_sync (portal->bus,
+                                                       PORTAL_BUS_NAME,
+                                                       PORTAL_OBJECT_PATH,
+                                                       "org.freedesktop.portal.RemoteDesktop",
+                                                       "ConnectToEIS",
+                                                       g_variant_new ("(oa{sv})",
+                                                                      session->id,
+                                                                      &options),
+                                                       NULL,
+                                                       G_DBUS_CALL_FLAGS_NONE,
+                                                       -1,
+                                                       NULL,
+                                                       &fd_list,
+                                                       NULL,
+                                                       &error);
+  if (!ret)
+    {
+      g_warning ("Failed to ConnectToEIS: %s", error->message);
+      return -ENODEV;
+    }
+
+  session->uses_eis = TRUE;
+
+  g_variant_get (ret, "(h)", &fd_out);
+
+  return g_unix_fd_list_get (fd_list, fd_out, NULL);
+}
+
 static void
 create_call_free (CreateCall *call)
 {
@@ -899,6 +961,7 @@ is_active_remotedesktop_session (XdpSession    *session,
   return XDP_IS_SESSION (session) &&
          session->type == XDP_SESSION_REMOTE_DESKTOP &&
          session->state == XDP_SESSION_ACTIVE &&
+         !session->uses_eis &&
          (session->devices & required_device) != 0;
 }
 

libportal/remote.h

@@ -199,6 +199,9 @@ XdpDeviceType   xdp_session_get_devices       (XdpSession *session);
 XDP_PUBLIC
 GVariant *      xdp_session_get_streams       (XdpSession *session);
 
+XDP_PUBLIC
+int       xdp_session_connect_to_eis    (XdpSession *session);
+
 XDP_PUBLIC
 void      xdp_session_pointer_motion    (XdpSession *session,
                                          double      dx,

libportal/session-private.h

@@ -33,6 +33,7 @@ struct _XdpSession {
 
   XdpPersistMode persist_mode;
   char *restore_token;
+  gboolean uses_eis;
 
   guint signal_id;
 };

tests/pyportaltest/templates/remotedesktop.py

@@ -26,7 +26,7 @@ def load(mock, parameters):
 
     params = MockParams.get(mock, MAIN_IFACE)
     params.delay = 500
-    params.version = parameters.get("version", 1)
+    params.version = parameters.get("version", 2)
     params.response = parameters.get("response", 0)
     params.devices = parameters.get("devices", 0b111)
     params.sessions: Dict[str, Session] = {}
@@ -245,3 +245,24 @@ def NotifyTouchUp(self, session_handle, options, slot):
         logger.debug(f"NotifyTouchMotion: {session_handle} {options} {slot}")
     except Exception as e:
         logger.critical(e)
+
+
+@dbus.service.method(
+    MAIN_IFACE,
+    in_signature="oa{sv}",
+    out_signature="h",
+)
+def ConnectToEIS(self, session_handle, options):
+    try:
+        logger.debug(f"ConnectToEIS: {session_handle} {options}")
+        import socket
+
+        sockets = socket.socketpair()
+        # Write some random data down so it'll break anything that actually
+        # expects the socket to be a real EIS socket
+        sockets[0].send(b"VANILLA")
+        fd = sockets[1]
+        logger.debug(f"ConnectToEIS with fd {fd.fileno()}")
+        return dbus.types.UnixFd(fd)
+    except Exception as e:
+        logger.critical(e)

tests/pyportaltest/test_remotedesktop.py

@@ -4,6 +4,7 @@
 
 from . import PortalTest
 
+import errno
 import dbus
 import gi
 import logging
@@ -33,7 +34,7 @@ class SessionSetup(NamedTuple):
 
 class TestRemoteDesktop(PortalTest):
     def test_version(self):
-        self.assert_version_eq(1)
+        self.assert_version_eq(2)
 
     def short_mainloop(self):
         """
@@ -414,6 +415,46 @@ def test_notify_touch(self):
         session_handle, options, slot = args
         assert slot == 10
 
+    def test_connect_to_eis_v1(self):
+        params = {"version": 1}
+        setup = self.create_session(params=params, start_session=False)
+        session = setup.session
+
+        err = session.connect_to_eis()
+        assert err == -errno.ENOTSUP
+
+    def test_connect_to_eis(self):
+        setup = self.create_session(start_session=False)
+        session = setup.session
+        handle = session.connect_to_eis()
+        assert handle
+
+        fd = os.fdopen(handle)
+        buf = fd.read()
+        assert buf == "VANILLA"  # template sends this by default
+
+        method_calls = self.mock_interface.GetMethodCalls("ConnectToEIS")
+        assert len(method_calls) == 1
+        _, args = method_calls.pop(0)
+        session_handle, options = args
+        assert "handle_token" not in options  # this is not a Request
+        assert list(options.keys()) == []
+
+    def test_connect_to_eis_fail_reconnect(self):
+        setup = self.create_session(start_session=False)
+        session = setup.session
+        handle = session.connect_to_eis()
+        assert handle
+
+        err = session.connect_to_eis()
+        assert err == -errno.EALREADY
+
+    def test_connect_to_eis_fail_connect_after_start(self):
+        setup = self.create_session(start_session=True)
+        session = setup.session
+        err = session.connect_to_eis()
+        assert err == -errno.EBUSY
+
     def test_close_session(self):
         """
         Ensure that closing our session explicitly closes the session on DBus