Struct DebugControllerDBus

pub struct DebugControllerDBus { /* private fields */ }

Available on crate feature v2_72 only.

GDebugControllerDBus is an implementation of DebugController which exposes debug settings as a D-Bus object.

It is a Initable object, and will register an object at /org/gtk/Debugging on the bus given as connection once it’s initialized. The object will be unregistered when the last reference to the GDebugControllerDBus is dropped.

This D-Bus object can be used by remote processes to enable or disable debug output in this process. Remote processes calling org.gtk.Debugging.SetDebugEnabled() will affect the value of debug-enabled and, by default, log_get_debug_enabled().

By default, no processes are allowed to call SetDebugEnabled() unless a authorize signal handler is installed. This is because the process may be privileged, or might expose sensitive information in its debug output. You may want to restrict the ability to enable debug output to privileged users or processes.

One option is to install a D-Bus security policy which restricts access to SetDebugEnabled(), installing something like the following in $datadir/dbus-1/system.d/:

<?xml version="1.0"?> <!--*-nxml-*-->
<!DOCTYPE busconfig PUBLIC "-//freedesktop//DTD D-BUS Bus Configuration 1.0//EN"
     "http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd">
<busconfig>
  <policy user="root">
    <allow send_destination="com.example.MyService" send_interface="org.gtk.Debugging"/>
  </policy>
  <policy context="default">
    <deny send_destination="com.example.MyService" send_interface="org.gtk.Debugging"/>
  </policy>
</busconfig>

This will prevent the SetDebugEnabled() method from being called by all except root. It will not prevent the DebugEnabled property from being read, as it’s accessed through the org.freedesktop.DBus.Properties interface.

Another option is to use polkit to allow or deny requests on a case-by-case basis, allowing for the possibility of dynamic authorisation. To do this, connect to the authorize signal and query polkit in it:

⚠️ The following code is in c ⚠️

  g_autoptr(GError) child_error = NULL;
  g_autoptr(GDBusConnection) connection = g_bus_get_sync (G_BUS_TYPE_SYSTEM, NULL, NULL);
  gulong debug_controller_authorize_id = 0;

  // Set up the debug controller.
  debug_controller = G_DEBUG_CONTROLLER (g_debug_controller_dbus_new (priv->connection, NULL, &child_error));
  if (debug_controller == NULL)
    {
      g_error ("Could not register debug controller on bus: %s"),
               child_error->message);
    }

  debug_controller_authorize_id = g_signal_connect (debug_controller,
                                                    "authorize",
                                                    G_CALLBACK (debug_controller_authorize_cb),
                                                    self);

  static gboolean
  debug_controller_authorize_cb (GDebugControllerDBus  *debug_controller,
                                 GDBusMethodInvocation *invocation,
                                 gpointer               user_data)
  {
    g_autoptr(PolkitAuthority) authority = NULL;
    g_autoptr(PolkitSubject) subject = NULL;
    g_autoptr(PolkitAuthorizationResult) auth_result = NULL;
    g_autoptr(GError) local_error = NULL;
    GDBusMessage *message;
    GDBusMessageFlags message_flags;
    PolkitCheckAuthorizationFlags flags = POLKIT_CHECK_AUTHORIZATION_FLAGS_NONE;

    message = g_dbus_method_invocation_get_message (invocation);
    message_flags = g_dbus_message_get_flags (message);

    authority = polkit_authority_get_sync (NULL, &local_error);
    if (authority == NULL)
      {
        g_warning ("Failed to get polkit authority: %s", local_error->message);
        return FALSE;
      }

    if (message_flags & G_DBUS_MESSAGE_FLAGS_ALLOW_INTERACTIVE_AUTHORIZATION)
      flags |= POLKIT_CHECK_AUTHORIZATION_FLAGS_ALLOW_USER_INTERACTION;

    subject = polkit_system_bus_name_new (g_dbus_method_invocation_get_sender (invocation));

    auth_result = polkit_authority_check_authorization_sync (authority,
                                                             subject,
                                                             "com.example.MyService.set-debug-enabled",
                                                             NULL,
                                                             flags,
                                                             NULL,
                                                             &local_error);
    if (auth_result == NULL)
      {
        g_warning ("Failed to get check polkit authorization: %s", local_error->message);
        return FALSE;
      }

    return polkit_authorization_result_get_is_authorized (auth_result);
  }

Properties

connection

The D-Bus connection to expose the debugging interface on.

Typically this will be the same connection (to the system or session bus) which the rest of the application or service’s D-Bus objects are registered on.

Readable | Writeable | Construct Only

DebugController

debug-enabled

true if debug output should be exposed (for example by forwarding it to the journal), false otherwise.

Readable | Writeable

Signals

authorize

Emitted when a D-Bus peer is trying to change the debug settings and used to determine if that is authorized.

This signal is emitted in a dedicated worker thread, so handlers are allowed to perform blocking I/O. This means that, for example, it is appropriate to call polkit_authority_check_authorization_sync() to check authorization using polkit.

If false is returned then no further handlers are run and the request to change the debug settings is rejected.

Otherwise, if true is returned, signal emission continues. If no handlers return false, then the debug settings are allowed to be changed.

Signal handlers must not modify @invocation, or cause it to return a value.

The default class handler just returns true.

Implements

DebugControllerDBusExt, [trait@glib::ObjectExt], DebugControllerExt, InitableExt, DebugControllerDBusExtManual

GLib type: GObject with reference counted clone semantics.

Implementations

impl DebugControllerDBus

pub const NONE: Option<&'static DebugControllerDBus> = None

pub fn new( connection: &DBusConnection, cancellable: Option<&impl IsA<Cancellable>>, ) -> Result<Option<DebugControllerDBus>, Error>

Create a new #GDebugControllerDBus and synchronously initialize it.

Initializing the object will export the debug object on @connection. The object will remain registered until the last reference to the #GDebugControllerDBus is dropped.

Initialization may fail if registering the object on @connection fails.

connection

a #GDBusConnection to register the debug object on

cancellable

a #GCancellable, or None

Returns

a new #GDebugControllerDBus, or None on failure

Trait Implementations

impl Clone for DebugControllerDBus

fn clone(&self) -> Self

Makes a clone of this shared reference.

This increments the strong reference count of the object. Dropping the object will decrement it again.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for DebugControllerDBus

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl HasParamSpec for DebugControllerDBus

type ParamSpec = ParamSpecObject

type SetValue = DebugControllerDBus

Preferred value to be used as setter for the associated ParamSpec.

type BuilderFn = fn(_: &str) -> ParamSpecObjectBuilder<'_, DebugControllerDBus>

fn param_spec_builder() -> Self::BuilderFn

impl Hash for DebugControllerDBus

fn hash<H>(&self, state: &mut H)

where H: Hasher,

Hashes the memory address of this object.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for DebugControllerDBus

fn cmp(&self, other: &Self) -> Ordering

Comparison for two GObjects.

Compares the memory addresses of the provided objects.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl ParentClassIs for DebugControllerDBus

type Parent = Object

impl<OT: ObjectType> PartialEq<OT> for DebugControllerDBus

fn eq(&self, other: &OT) -> bool

Equality for two GObjects.

Two GObjects are equal if their memory addresses are equal.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<OT: ObjectType> PartialOrd<OT> for DebugControllerDBus

fn partial_cmp(&self, other: &OT) -> Option<Ordering>

Partial comparison for two GObjects.

Compares the memory addresses of the provided objects.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StaticType for DebugControllerDBus

fn static_type() -> Type

Returns the type identifier of Self.

impl Eq for DebugControllerDBus

impl IsA<DebugController> for DebugControllerDBus

impl IsA<Initable> for DebugControllerDBus