/* GDBus - GLib D-Bus Library

 *

 * Copyright (C) 2008-2010 Red Hat, Inc.

 *

 * SPDX-License-Identifier: LGPL-2.1-or-later

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General

 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.

 *

 * Author: David Zeuthen <davidz@redhat.com>

 */

#include "config.h"

#include "gdbusinterface.h"

#include "gdbusinterfaceskeleton.h"

#include "gdbusobjectskeleton.h"

#include "gioenumtypes.h"

#include "gdbusprivate.h"

#include "gdbusmethodinvocation.h"

#include "gdbusconnection.h"

#include "gmarshal-internal.h"

#include "gtask.h"

#include "gioerror.h"

#include "glibintl.h"

/**

 * GDBusInterfaceSkeleton:

 *

 * Abstract base class for D-Bus interfaces on the service side.

 *

 * Since: 2.30

 */

struct _GDBusInterfaceSkeletonPrivate

{

  GMutex                      lock;

  GDBusObject                *object;

  GDBusInterfaceSkeletonFlags flags;

  GSList                     *connections;   /* List of ConnectionData */

  gchar                      *object_path;   /* The object path for this skeleton */

  GDBusInterfaceVTable       *hooked_vtable;

};

typedef struct

{

  GDBusConnection *connection;

  guint            registration_id;

} ConnectionData;

enum

{

  G_AUTHORIZE_METHOD_SIGNAL,

  LAST_SIGNAL

};

enum

{

  PROP_0,

  PROP_G_FLAGS

};

static guint signals[LAST_SIGNAL] = {0};

static void     dbus_interface_interface_init                      (GDBusInterfaceIface    *iface);

static void     set_object_path_locked                             (GDBusInterfaceSkeleton *interface_,

                                                                    const gchar            *object_path);

static void     remove_connection_locked                           (GDBusInterfaceSkeleton *interface_,

                                                                    GDBusConnection        *connection);

static void     skeleton_intercept_handle_method_call              (GDBusConnection        *connection,

                                                                    const gchar            *sender,

                                                                    const gchar            *object_path,

                                                                    const gchar            *interface_name,

                                                                    const gchar            *method_name,

                                                                    GVariant               *parameters,

                                                                    GDBusMethodInvocation  *invocation,

                                                                    gpointer                user_data);

static void g_dbus_interface_skeleton_method_dispatch_real         (GDBusInterfaceSkeleton       *interface,

                                                                    GDBusInterfaceMethodCallFunc  method_call_func,

                                                                    GDBusMethodInvocation        *invocation,

                                                                    GDBusInterfaceSkeletonFlags   flags,

                                                                    GDBusObject                  *object);

G_DEFINE_ABSTRACT_TYPE_WITH_CODE (GDBusInterfaceSkeleton, g_dbus_interface_skeleton, G_TYPE_OBJECT,

                                  G_ADD_PRIVATE (GDBusInterfaceSkeleton)

                                  G_IMPLEMENT_INTERFACE (G_TYPE_DBUS_INTERFACE, dbus_interface_interface_init))

static void

g_dbus_interface_skeleton_finalize (GObject *object)

{

  GDBusInterfaceSkeleton *interface = G_DBUS_INTERFACE_SKELETON (object);

  /* Hold the lock just in case any code we call verifies that the lock is held */

  g_mutex_lock (&interface->priv->lock);

  /* unexport from all connections if we're exported anywhere */

  while (interface->priv->connections != NULL)

    {

      ConnectionData *data = interface->priv->connections->data;

      remove_connection_locked (interface, data->connection);

    }

  set_object_path_locked (interface, NULL);

  g_mutex_unlock (&interface->priv->lock);

  g_free (interface->priv->hooked_vtable);

  if (interface->priv->object != NULL)

    g_object_remove_weak_pointer (G_OBJECT (interface->priv->object), (gpointer *) &interface->priv->object);

  g_mutex_clear (&interface->priv->lock);

  G_OBJECT_CLASS (g_dbus_interface_skeleton_parent_class)->finalize (object);

}

static void

g_dbus_interface_skeleton_get_property (GObject      *object,

                                        guint         prop_id,

                                        GValue       *value,

                                        GParamSpec   *pspec)

{

  GDBusInterfaceSkeleton *interface = G_DBUS_INTERFACE_SKELETON (object);

  switch (prop_id)

    {

    case PROP_G_FLAGS:

      g_value_set_flags (value, g_dbus_interface_skeleton_get_flags (interface));

      break;

    default:

      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

      break;

    }

}

static void

g_dbus_interface_skeleton_set_property (GObject      *object,

                                        guint         prop_id,

                                        const GValue *value,

                                        GParamSpec   *pspec)

{

  GDBusInterfaceSkeleton *interface = G_DBUS_INTERFACE_SKELETON (object);

  switch (prop_id)

    {

    case PROP_G_FLAGS:

      g_dbus_interface_skeleton_set_flags (interface, g_value_get_flags (value));

      break;

    default:

      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

      break;

    }

}

static gboolean

g_dbus_interface_skeleton_g_authorize_method_default (GDBusInterfaceSkeleton    *interface,

                                                      GDBusMethodInvocation *invocation)

{

  return TRUE;

}

static void

g_dbus_interface_skeleton_class_init (GDBusInterfaceSkeletonClass *klass)

{

  GObjectClass *gobject_class;

  gobject_class = G_OBJECT_CLASS (klass);

  gobject_class->finalize     = g_dbus_interface_skeleton_finalize;

  gobject_class->set_property = g_dbus_interface_skeleton_set_property;

  gobject_class->get_property = g_dbus_interface_skeleton_get_property;

  klass->g_authorize_method = g_dbus_interface_skeleton_g_authorize_method_default;

  klass->method_dispatch = g_dbus_interface_skeleton_method_dispatch_real;

  /**

   * GDBusInterfaceSkeleton:g-flags:

   *

   * Flags from the #GDBusInterfaceSkeletonFlags enumeration.

   *

   * Since: 2.30

   */

  g_object_class_install_property (gobject_class,

                                   PROP_G_FLAGS,

                                   g_param_spec_flags ("g-flags", NULL, NULL,

                                                       G_TYPE_DBUS_INTERFACE_SKELETON_FLAGS,

                                                       G_DBUS_INTERFACE_SKELETON_FLAGS_NONE,

                                                       G_PARAM_READABLE |

                                                       G_PARAM_WRITABLE |

                                                       G_PARAM_STATIC_STRINGS));

  /**

   * GDBusInterfaceSkeleton::g-authorize-method:

   * @interface: The #GDBusInterfaceSkeleton emitting the signal.

   * @invocation: A #GDBusMethodInvocation.

   *

   * Emitted when a method is invoked by a remote caller and used to

   * determine if the method call is authorized.

   *

   * Note that this signal is emitted in a thread dedicated to

   * handling the method call so handlers are allowed to perform

   * blocking IO. This means that it is appropriate to call e.g.

   * [polkit_authority_check_authorization_sync()](http://hal.freedesktop.org/docs/polkit/PolkitAuthority.html#polkit-authority-check-authorization-sync)

   * with the

   * [POLKIT_CHECK_AUTHORIZATION_FLAGS_ALLOW_USER_INTERACTION](http://hal.freedesktop.org/docs/polkit/PolkitAuthority.html#POLKIT-CHECK-AUTHORIZATION-FLAGS-ALLOW-USER-INTERACTION:CAPS)

   * flag set.

   *

   * If %FALSE is returned then no further handlers are run and the

   * signal handler must take a reference to @invocation and finish

   * handling the call (e.g. return an error via

   * g_dbus_method_invocation_return_error()).

   *

   * Otherwise, if %TRUE is returned, signal emission continues. If no

   * handlers return %FALSE, then the method is dispatched. If

   * @interface has an enclosing #GDBusObjectSkeleton, then the

   * #GDBusObjectSkeleton::authorize-method signal handlers run before

   * the handlers for this signal.

   *

   * The default class handler just returns %TRUE.

   *

   * Please note that the common case is optimized: if no signals

   * handlers are connected and the default class handler isn't

   * overridden (for both @interface and the enclosing

   * #GDBusObjectSkeleton, if any) and #GDBusInterfaceSkeleton:g-flags does

   * not have the

   * %G_DBUS_INTERFACE_SKELETON_FLAGS_HANDLE_METHOD_INVOCATIONS_IN_THREAD

   * flags set, no dedicated thread is ever used and the call will be

   * handled in the same thread as the object that @interface belongs

   * to was exported in.

   *

   * Returns: %TRUE if the call is authorized, %FALSE otherwise.

   *

   * Since: 2.30

   */

  signals[G_AUTHORIZE_METHOD_SIGNAL] =

    g_signal_new (I_("g-authorize-method"),

                  G_TYPE_DBUS_INTERFACE_SKELETON,

                  G_SIGNAL_RUN_LAST,

                  G_STRUCT_OFFSET (GDBusInterfaceSkeletonClass, g_authorize_method),

                  _g_signal_accumulator_false_handled,

                  NULL,

                  _g_cclosure_marshal_BOOLEAN__OBJECT,

                  G_TYPE_BOOLEAN,

                  1,

                  G_TYPE_DBUS_METHOD_INVOCATION);

  g_signal_set_va_marshaller (signals[G_AUTHORIZE_METHOD_SIGNAL],

                              G_TYPE_FROM_CLASS (klass),

                              _g_cclosure_marshal_BOOLEAN__OBJECTv);

}

static void

g_dbus_interface_skeleton_init (GDBusInterfaceSkeleton *interface)

{

  interface->priv = g_dbus_interface_skeleton_get_instance_private (interface);

  g_mutex_init (&interface->priv->lock);

}

/* ---------------------------------------------------------------------------------------------------- */

/**

 * g_dbus_interface_skeleton_get_flags:

 * @interface_: A #GDBusInterfaceSkeleton.

 *

 * Gets the #GDBusInterfaceSkeletonFlags that describes what the behavior

 * of @interface_

 *

 * Returns: One or more flags from the #GDBusInterfaceSkeletonFlags enumeration.

 *

 * Since: 2.30

 */

GDBusInterfaceSkeletonFlags

g_dbus_interface_skeleton_get_flags (GDBusInterfaceSkeleton  *interface_)

{

  g_return_val_if_fail (G_IS_DBUS_INTERFACE_SKELETON (interface_), G_DBUS_INTERFACE_SKELETON_FLAGS_NONE);

  return interface_->priv->flags;

}

/**

 * g_dbus_interface_skeleton_set_flags:

 * @interface_: A #GDBusInterfaceSkeleton.

 * @flags: Flags from the #GDBusInterfaceSkeletonFlags enumeration.

 *

 * Sets flags describing what the behavior of @skeleton should be.

 *

 * Since: 2.30

 */

void

g_dbus_interface_skeleton_set_flags (GDBusInterfaceSkeleton      *interface_,

                                     GDBusInterfaceSkeletonFlags  flags)

{

  g_return_if_fail (G_IS_DBUS_INTERFACE_SKELETON (interface_));

  g_mutex_lock (&interface_->priv->lock);

  if (interface_->priv->flags != flags)

    {

      interface_->priv->flags = flags;

      g_mutex_unlock (&interface_->priv->lock);

      g_object_notify (G_OBJECT (interface_), "g-flags");

    }

  else

    {

      g_mutex_unlock (&interface_->priv->lock);

    }

}

/**

 * g_dbus_interface_skeleton_get_info:

 * @interface_: A #GDBusInterfaceSkeleton.

 *

 * Gets D-Bus introspection information for the D-Bus interface

 * implemented by @interface_.

 *

 * Returns: (transfer none): A #GDBusInterfaceInfo (never %NULL). Do not free.

 *

 * Since: 2.30

 */

GDBusInterfaceInfo *

g_dbus_interface_skeleton_get_info (GDBusInterfaceSkeleton *interface_)

{

  GDBusInterfaceInfo *ret;

  g_return_val_if_fail (G_IS_DBUS_INTERFACE_SKELETON (interface_), NULL);

  ret = G_DBUS_INTERFACE_SKELETON_GET_CLASS (interface_)->get_info (interface_);

  g_warn_if_fail (ret != NULL);

  return ret;

}

/**

 * g_dbus_interface_skeleton_get_vtable:

 * @interface_: A #GDBusInterfaceSkeleton.

 *

 * Gets the interface vtable for the D-Bus interface implemented by

 * @interface_. The returned function pointers should expect @interface_

 * itself to be passed as @user_data.

 *

 * Returns: (not nullable) (transfer none): the vtable of the D-Bus interface implemented by the skeleton

 *

 * Since: 2.30

 */

GDBusInterfaceVTable *

g_dbus_interface_skeleton_get_vtable (GDBusInterfaceSkeleton *interface_)

{

  GDBusInterfaceVTable *ret;

  g_return_val_if_fail (G_IS_DBUS_INTERFACE_SKELETON (interface_), NULL);

  ret = G_DBUS_INTERFACE_SKELETON_GET_CLASS (interface_)->get_vtable (interface_);

  g_warn_if_fail (ret != NULL);

  return ret;

}

/**

 * g_dbus_interface_skeleton_get_properties:

 * @interface_: A #GDBusInterfaceSkeleton.

 *

 * Gets all D-Bus properties for @interface_.

 *

 * Returns: (transfer full): A #GVariant of type

 * ['a{sv}'](../glib/gvariant-text-format.html#dictionaries-and-dictionary-entries).

 * Free with g_variant_unref().

 *

 * Since: 2.30

 */

GVariant *

g_dbus_interface_skeleton_get_properties (GDBusInterfaceSkeleton *interface_)

{

  GVariant *ret;

  g_return_val_if_fail (G_IS_DBUS_INTERFACE_SKELETON (interface_), NULL);

  ret = G_DBUS_INTERFACE_SKELETON_GET_CLASS (interface_)->get_properties (interface_);

  return g_variant_take_ref (ret);

}

/**

 * g_dbus_interface_skeleton_flush:

 * @interface_: A #GDBusInterfaceSkeleton.

 *

 * If @interface_ has outstanding changes, request for these changes to be

 * emitted immediately.

 *

 * For example, an exported D-Bus interface may queue up property

 * changes and emit the

 * `org.freedesktop.DBus.Properties.PropertiesChanged`

 * signal later (e.g. in an idle handler). This technique is useful

 * for collapsing multiple property changes into one.

 *

 * Since: 2.30

 */

void

g_dbus_interface_skeleton_flush (GDBusInterfaceSkeleton *interface_)

{

  g_return_if_fail (G_IS_DBUS_INTERFACE_SKELETON (interface_));

  G_DBUS_INTERFACE_SKELETON_GET_CLASS (interface_)->flush (interface_);

}

/* ---------------------------------------------------------------------------------------------------- */

static GDBusInterfaceInfo *

_g_dbus_interface_skeleton_get_info (GDBusInterface *interface_)

{

  GDBusInterfaceSkeleton *interface = G_DBUS_INTERFACE_SKELETON (interface_);

  return g_dbus_interface_skeleton_get_info (interface);

}

static GDBusObject *

g_dbus_interface_skeleton_get_object (GDBusInterface *interface_)

{

  GDBusInterfaceSkeleton *interface = G_DBUS_INTERFACE_SKELETON (interface_);

  GDBusObject *ret;

  g_mutex_lock (&interface->priv->lock);

  ret = interface->priv->object;

  g_mutex_unlock (&interface->priv->lock);

  return ret;

}

static GDBusObject *

g_dbus_interface_skeleton_dup_object (GDBusInterface *interface_)

{

  GDBusInterfaceSkeleton *interface = G_DBUS_INTERFACE_SKELETON (interface_);

  GDBusObject *ret;

  g_mutex_lock (&interface->priv->lock);

  ret = interface->priv->object;

  if (ret != NULL)

    g_object_ref (ret);

  g_mutex_unlock (&interface->priv->lock);

  return ret;

}

static void

g_dbus_interface_skeleton_set_object (GDBusInterface *interface_,

                                      GDBusObject    *object)

{

  GDBusInterfaceSkeleton *interface = G_DBUS_INTERFACE_SKELETON (interface_);

  g_mutex_lock (&interface->priv->lock);

  if (interface->priv->object != NULL)

    g_object_remove_weak_pointer (G_OBJECT (interface->priv->object), (gpointer *) &interface->priv->object);

  interface->priv->object = object;

  if (object != NULL)

    g_object_add_weak_pointer (G_OBJECT (interface->priv->object), (gpointer *) &interface->priv->object);

  g_mutex_unlock (&interface->priv->lock);

}

static void

dbus_interface_interface_init (GDBusInterfaceIface *iface)

{

  iface->get_info    = _g_dbus_interface_skeleton_get_info;

  iface->get_object  = g_dbus_interface_skeleton_get_object;

  iface->dup_object  = g_dbus_interface_skeleton_dup_object;

  iface->set_object  = g_dbus_interface_skeleton_set_object;

}

/* ---------------------------------------------------------------------------------------------------- */

typedef struct

{

  gint ref_count;  /* (atomic) */

  GDBusInterfaceMethodCallFunc  method_call_func;

  GDBusMethodInvocation        *invocation;  /* (owned) */

} DispatchData;

static void

dispatch_data_unref (DispatchData *data)

{

  if (g_atomic_int_dec_and_test (&data->ref_count))

    {

      g_clear_object (&data->invocation);

      g_slice_free (DispatchData, data);

    }

}

static DispatchData *

dispatch_data_ref (DispatchData *data)

{

  g_atomic_int_inc (&data->ref_count);

  return data;

}

static gboolean

dispatch_invoke_in_context_func (gpointer user_data)

{

  DispatchData *data = user_data;

  data->method_call_func (g_dbus_method_invocation_get_connection (data->invocation),

                          g_dbus_method_invocation_get_sender (data->invocation),

                          g_dbus_method_invocation_get_object_path (data->invocation),

                          g_dbus_method_invocation_get_interface_name (data->invocation),

                          g_dbus_method_invocation_get_method_name (data->invocation),

                          g_dbus_method_invocation_get_parameters (data->invocation),

                          data->invocation,

                          g_dbus_method_invocation_get_user_data (data->invocation));

  return FALSE;

}

static void

dispatch_in_thread_func (GTask        *task,

                         gpointer      source_object,

                         gpointer      task_data,

                         GCancellable *cancellable)

{

  DispatchData *data = task_data;

  GDBusInterfaceSkeleton *interface = g_task_get_source_object (task);

  GDBusInterfaceSkeletonFlags flags;

  GDBusObject *object;

  gboolean authorized;

  g_mutex_lock (&interface->priv->lock);

  flags = interface->priv->flags;

  object = interface->priv->object;

  if (object != NULL)

    g_object_ref (object);

  g_mutex_unlock (&interface->priv->lock);

  /* first check on the enclosing object (if any), then the interface */

  authorized = TRUE;

  if (object != NULL)

    {

      g_signal_emit_by_name (object,

                             "authorize-method",

                             interface,

                             data->invocation,

                             &authorized);

    }

  if (authorized)

    {

      g_signal_emit (interface,

                     signals[G_AUTHORIZE_METHOD_SIGNAL],

                     0,

                     data->invocation,

                     &authorized);

    }

  if (authorized)

    {

      gboolean run_in_thread;

      run_in_thread = (flags & G_DBUS_INTERFACE_SKELETON_FLAGS_HANDLE_METHOD_INVOCATIONS_IN_THREAD);

      if (run_in_thread)

        {

          /* might as well just re-use the existing thread */

          data->method_call_func (g_dbus_method_invocation_get_connection (data->invocation),

                                  g_dbus_method_invocation_get_sender (data->invocation),

                                  g_dbus_method_invocation_get_object_path (data->invocation),

                                  g_dbus_method_invocation_get_interface_name (data->invocation),

                                  g_dbus_method_invocation_get_method_name (data->invocation),

                                  g_dbus_method_invocation_get_parameters (data->invocation),

                                  data->invocation,

                                  g_dbus_method_invocation_get_user_data (data->invocation));

        }

      else

        {

          /* bah, back to original context */

          g_main_context_invoke_full (g_task_get_context (task),

                                      g_task_get_priority (task),

                                      dispatch_invoke_in_context_func,

                                      dispatch_data_ref (data),

                                      (GDestroyNotify) dispatch_data_unref);

        }

    }

  else

    {

      /* do nothing */

    }

  if (object != NULL)

    g_object_unref (object);

  g_task_return_boolean (task, TRUE);

}

static void

g_dbus_interface_skeleton_method_dispatch_real (GDBusInterfaceSkeleton       *interface,

                                                GDBusInterfaceMethodCallFunc  method_call_func,

                                                GDBusMethodInvocation        *invocation,

                                                GDBusInterfaceSkeletonFlags   flags,

                                                GDBusObject                  *object)

{

  gboolean has_handlers;

  gboolean has_default_class_handler;

  gboolean emit_authorized_signal;

  gboolean run_in_thread;

  g_return_if_fail (G_IS_DBUS_INTERFACE_SKELETON (interface));

  g_return_if_fail (method_call_func != NULL);

  g_return_if_fail (G_IS_DBUS_METHOD_INVOCATION (invocation));

  /* optimization for the common case where

   *

   *  a) no handler is connected and class handler is not overridden (both interface and object); and

   *  b) method calls are not dispatched in a thread

   */

  has_handlers = g_signal_has_handler_pending (interface,

                                               signals[G_AUTHORIZE_METHOD_SIGNAL],

                                               0,

                                               TRUE);

  has_default_class_handler = (G_DBUS_INTERFACE_SKELETON_GET_CLASS (interface)->g_authorize_method ==

                               g_dbus_interface_skeleton_g_authorize_method_default);

  emit_authorized_signal = (has_handlers || !has_default_class_handler);

  if (!emit_authorized_signal)

    {

      if (object != NULL)

        emit_authorized_signal = _g_dbus_object_skeleton_has_authorize_method_handlers (G_DBUS_OBJECT_SKELETON (object));

    }

  run_in_thread = (flags & G_DBUS_INTERFACE_SKELETON_FLAGS_HANDLE_METHOD_INVOCATIONS_IN_THREAD);

  if (!emit_authorized_signal && !run_in_thread)

    {

      method_call_func (g_dbus_method_invocation_get_connection (invocation),

                        g_dbus_method_invocation_get_sender (invocation),

                        g_dbus_method_invocation_get_object_path (invocation),

                        g_dbus_method_invocation_get_interface_name (invocation),

                        g_dbus_method_invocation_get_method_name (invocation),

                        g_dbus_method_invocation_get_parameters (invocation),

                        invocation,

                        g_dbus_method_invocation_get_user_data (invocation));

    }

  else

    {

      GTask *task;

      DispatchData *data;

      data = g_slice_new0 (DispatchData);

      data->method_call_func = method_call_func;

      data->invocation = g_object_ref (invocation);

      data->ref_count = 1;

      task = g_task_new (interface, NULL, NULL, NULL);

      g_task_set_source_tag (task, g_dbus_interface_skeleton_method_dispatch_real);

      g_task_set_name (task, "[gio] D-Bus interface method dispatch");

      g_task_set_task_data (task, data, (GDestroyNotify) dispatch_data_unref);

      g_task_run_in_thread (task, dispatch_in_thread_func);

      g_object_unref (task);

    }

}

static void

skeleton_intercept_handle_method_call (GDBusConnection       *connection,

                                       const gchar           *sender,

                                       const gchar           *object_path,

                                       const gchar           *interface_name,

                                       const gchar           *method_name,

                                       GVariant              *parameters,

                                       GDBusMethodInvocation *invocation,

                                       gpointer               user_data)

{

  GDBusInterfaceSkeleton *interface = G_DBUS_INTERFACE_SKELETON (user_data);

  GDBusInterfaceSkeletonFlags flags;

  GDBusObject *object = NULL;

  g_mutex_lock (&interface->priv->lock);

  flags = interface->priv->flags;

  g_set_object (&object, interface->priv->object);

  g_mutex_unlock (&interface->priv->lock);

  G_DBUS_INTERFACE_SKELETON_GET_CLASS (interface)->method_dispatch (

      interface,

      g_dbus_interface_skeleton_get_vtable (interface)->method_call,

      invocation,

      flags,

      object);

  g_clear_object (&object);

}

/* ---------------------------------------------------------------------------------------------------- */

static ConnectionData *

new_connection (GDBusConnection *connection,

                guint            registration_id)

{

  ConnectionData *data;

  data = g_slice_new0 (ConnectionData);

  data->connection      = g_object_ref (connection);

  data->registration_id = registration_id;

  return data;

}

static void

free_connection (ConnectionData *data)

{

  if (data != NULL)

    {

      g_object_unref (data->connection);

      g_slice_free (ConnectionData, data);

    }

}

static gboolean

add_connection_locked (GDBusInterfaceSkeleton *interface_,

                       GDBusConnection        *connection,

                       GError                **error)

{

  ConnectionData *data;

  guint registration_id;

  gboolean ret = FALSE;

  if (interface_->priv->hooked_vtable == NULL)

    {

      /* Hook the vtable since we need to intercept method calls for

       * ::g-authorize-method and for dispatching in thread vs

       * context

       *

       * We need to wait until subclasses have had time to initialize

       * properly before building the hooked_vtable, so we create it

       * once at the last minute.

       */

      interface_->priv->hooked_vtable = g_memdup2 (g_dbus_interface_skeleton_get_vtable (interface_), sizeof (GDBusInterfaceVTable));

      interface_->priv->hooked_vtable->method_call = skeleton_intercept_handle_method_call;

    }

  registration_id = g_dbus_connection_register_object (connection,

                                                       interface_->priv->object_path,

                                                       g_dbus_interface_skeleton_get_info (interface_),

                                                       interface_->priv->hooked_vtable,

                                                       interface_,

                                                       NULL, /* user_data_free_func */

                                                       error);

  if (registration_id > 0)

    {

      data = new_connection (connection, registration_id);

      interface_->priv->connections = g_slist_append (interface_->priv->connections, data);

      ret = TRUE;

    }

  return ret;

}

static void

remove_connection_locked (GDBusInterfaceSkeleton *interface_,

                          GDBusConnection        *connection)

{

  ConnectionData *data;

  GSList *l;

  /* Get the connection in the list and unregister ... */

  for (l = interface_->priv->connections; l != NULL; l = l->next)

    {

      data = l->data;

      if (data->connection == connection)

        {

          g_warn_if_fail (g_dbus_connection_unregister_object (data->connection, data->registration_id));

          free_connection (data);

          interface_->priv->connections = g_slist_delete_link (interface_->priv->connections, l);

          /* we are guaranteed that the connection is only added once, so bail out early */

          goto out;

        }

    }

 out:

  ;

}

static void

set_object_path_locked (GDBusInterfaceSkeleton *interface_,

                        const gchar            *object_path)

{

  if (g_strcmp0 (interface_->priv->object_path, object_path) != 0)

    {

      g_free (interface_->priv->object_path);

      interface_->priv->object_path = g_strdup (object_path);

    }

}

/* ---------------------------------------------------------------------------------------------------- */

/**

 * g_dbus_interface_skeleton_get_connection:

 * @interface_: A #GDBusInterfaceSkeleton.

 *

 * Gets the first connection that @interface_ is exported on, if any.

 *

 * Returns: (nullable) (transfer none): A #GDBusConnection or %NULL if @interface_ is

 * not exported anywhere. Do not free, the object belongs to @interface_.

 *

 * Since: 2.30

 */

GDBusConnection *

g_dbus_interface_skeleton_get_connection (GDBusInterfaceSkeleton *interface_)

{

  ConnectionData  *data;

  GDBusConnection *ret;

  g_return_val_if_fail (G_IS_DBUS_INTERFACE_SKELETON (interface_), NULL);

  g_mutex_lock (&interface_->priv->lock);

  ret = NULL;

  if (interface_->priv->connections != NULL)

    {

      data = interface_->priv->connections->data;

      if (data != NULL)

        ret = data->connection;

    }

  g_mutex_unlock (&interface_->priv->lock);

  return ret;

}

/**

 * g_dbus_interface_skeleton_get_connections:

 * @interface_: A #GDBusInterfaceSkeleton.

 *

 * Gets a list of the connections that @interface_ is exported on.

 *

 * Returns: (element-type GDBusConnection) (transfer full): A list of

 *   all the connections that @interface_ is exported on. The returned

 *   list should be freed with g_list_free() after each element has

 *   been freed with g_object_unref().

 *

 * Since: 2.32

 */

GList *

g_dbus_interface_skeleton_get_connections (GDBusInterfaceSkeleton *interface_)

{

  GList           *connections;

  GSList          *l;

  ConnectionData  *data;

  g_return_val_if_fail (G_IS_DBUS_INTERFACE_SKELETON (interface_), NULL);

  g_mutex_lock (&interface_->priv->lock);

  connections = NULL;

  for (l = interface_->priv->connections; l != NULL; l = l->next)

    {

      data        = l->data;

      connections = g_list_prepend (connections,

                                    /* Return a reference to each connection */

                                    g_object_ref (data->connection));

    }

  g_mutex_unlock (&interface_->priv->lock);

  return g_list_reverse (connections);

}

/**

 * g_dbus_interface_skeleton_has_connection:

 * @interface_: A #GDBusInterfaceSkeleton.

 * @connection: A #GDBusConnection.

 *

 * Checks if @interface_ is exported on @connection.

 *

 * Returns: %TRUE if @interface_ is exported on @connection, %FALSE otherwise.

 *

 * Since: 2.32

 */

gboolean

g_dbus_interface_skeleton_has_connection (GDBusInterfaceSkeleton     *interface_,

                                          GDBusConnection            *connection)

{

  GSList *l;

  gboolean ret = FALSE;

  g_return_val_if_fail (G_IS_DBUS_INTERFACE_SKELETON (interface_), FALSE);

  g_return_val_if_fail (G_IS_DBUS_CONNECTION (connection), FALSE);

  g_mutex_lock (&interface_->priv->lock);

  for (l = interface_->priv->connections; l != NULL; l = l->next)

    {

      ConnectionData *data = l->data;

      if (data->connection == connection)

        {

          ret = TRUE;

          goto out;

        }

    }

 out:

  g_mutex_unlock (&interface_->priv->lock);

  return ret;

}

/**

 * g_dbus_interface_skeleton_get_object_path:

 * @interface_: A #GDBusInterfaceSkeleton.

 *

 * Gets the object path that @interface_ is exported on, if any.

 *

 * Returns: (nullable): A string owned by @interface_ or %NULL if @interface_ is not exported

 * anywhere. Do not free, the string belongs to @interface_.

 *

 * Since: 2.30

 */

const gchar *

g_dbus_interface_skeleton_get_object_path (GDBusInterfaceSkeleton *interface_)

{

  const gchar *ret;

  g_return_val_if_fail (G_IS_DBUS_INTERFACE_SKELETON (interface_), NULL);

  g_mutex_lock (&interface_->priv->lock);

  ret = interface_->priv->object_path;

  g_mutex_unlock (&interface_->priv->lock);

  return ret;

}

/**

 * g_dbus_interface_skeleton_export:

 * @interface_: The D-Bus interface to export.

 * @connection: A #GDBusConnection to export @interface_ on.

 * @object_path: The path to export the interface at.

 * @error: Return location for error or %NULL.

 *

 * Exports @interface_ at @object_path on @connection.

 *

 * This can be called multiple times to export the same @interface_

 * onto multiple connections however the @object_path provided must be

 * the same for all connections.

 *

 * Use g_dbus_interface_skeleton_unexport() to unexport the object.

 *

 * Returns: %TRUE if the interface was exported on @connection, otherwise %FALSE with

 * @error set.

 *

 * Since: 2.30

 */

gboolean

g_dbus_interface_skeleton_export (GDBusInterfaceSkeleton  *interface_,

                                  GDBusConnection         *connection,

                                  const gchar             *object_path,

                                  GError                 **error)

{

  gboolean ret = FALSE;

  g_return_val_if_fail (G_IS_DBUS_INTERFACE_SKELETON (interface_), FALSE);

  g_return_val_if_fail (G_IS_DBUS_CONNECTION (connection), FALSE);

  g_return_val_if_fail (g_variant_is_object_path (object_path), FALSE);

  g_return_val_if_fail (error == NULL || *error == NULL, FALSE);

  /* Assert that the object path is the same for multiple connections here */

  g_return_val_if_fail (interface_->priv->object_path == NULL ||

                        g_strcmp0 (interface_->priv->object_path, object_path) == 0, FALSE);

  g_mutex_lock (&interface_->priv->lock);

  /* Set the object path */

  set_object_path_locked (interface_, object_path);

  /* Add the connection */

  ret = add_connection_locked (interface_, connection, error);

  g_mutex_unlock (&interface_->priv->lock);

  return ret;

}

/**

 * g_dbus_interface_skeleton_unexport:

 * @interface_: A #GDBusInterfaceSkeleton.

 *

 * Stops exporting @interface_ on all connections it is exported on.

 *

 * To unexport @interface_ from only a single connection, use

 * g_dbus_interface_skeleton_unexport_from_connection()

 *