gio/gdbusmethodinvocation.c

   1 /* GDBus - GLib D-Bus Library
   2  *
   3  * Copyright (C) 2008-2010 Red Hat, Inc.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2.1 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General
  16  * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
  17  *
  18  * Author: David Zeuthen <davidz@redhat.com>
  19  */
  20
  21 #include "config.h"
  22
  23 #include <stdlib.h>
  24
  25 #include "gdbusutils.h"
  26 #include "gdbusconnection.h"
  27 #include "gdbusmessage.h"
  28 #include "gdbusmethodinvocation.h"
  29 #include "gdbusintrospection.h"
  30 #include "gdbuserror.h"
  31 #include "gdbusprivate.h"
  32 #include "gioerror.h"
  33
  34 #ifdef G_OS_UNIX
  35 #include "gunixfdlist.h"
  36 #endif
  37
  38 #include "glibintl.h"
  39
  40 /**
  41  * SECTION:gdbusmethodinvocation
  42  * @short_description: Object for handling remote calls
  43  * @include: gio/gio.h
  44  *
  45  * Instances of the #GDBusMethodInvocation class are used when
  46  * handling D-Bus method calls. It provides a way to asynchronously
  47  * return results and errors.
  48  *
  49  * The normal way to obtain a #GDBusMethodInvocation object is to receive
  50  * it as an argument to the handle_method_call() function in a
  51  * #GDBusInterfaceVTable that was passed to g_dbus_connection_register_object().
  52  */
  53
  54 typedef struct _GDBusMethodInvocationClass GDBusMethodInvocationClass;
  55
  56 /**
  57  * GDBusMethodInvocationClass:
  58  *
  59  * Class structure for #GDBusMethodInvocation.
  60  *
  61  * Since: 2.26
  62  */
  63 struct _GDBusMethodInvocationClass
  64 {
  65   /*< private >*/
  66   GObjectClass parent_class;
  67 };
  68
  69 /**
  70  * GDBusMethodInvocation:
  71  *
  72  * The #GDBusMethodInvocation structure contains only private data and
  73  * should only be accessed using the provided API.
  74  *
  75  * Since: 2.26
  76  */
  77 struct _GDBusMethodInvocation
  78 {
  79   /*< private >*/
  80   GObject parent_instance;
  81
  82   /* construct-only properties */
  83   gchar           *sender;
  84   gchar           *object_path;
  85   gchar           *interface_name;
  86   gchar           *method_name;
  87   GDBusMethodInfo *method_info;
  88   GDBusPropertyInfo *property_info;
  89   GDBusConnection *connection;
  90   GDBusMessage    *message;
  91   GVariant        *parameters;
  92   gpointer         user_data;
  93 };
  94
  95 G_DEFINE_TYPE (GDBusMethodInvocation, g_dbus_method_invocation, G_TYPE_OBJECT)
  96
  97 static void
  98 g_dbus_method_invocation_finalize (GObject *object)
  99 {
 100   GDBusMethodInvocation *invocation = G_DBUS_METHOD_INVOCATION (object);
 101
 102   g_free (invocation->sender);
 103   g_free (invocation->object_path);
 104   g_free (invocation->interface_name);
 105   g_free (invocation->method_name);
 106   if (invocation->method_info)
 107       g_dbus_method_info_unref (invocation->method_info);
 108   if (invocation->property_info)
 109       g_dbus_property_info_unref (invocation->property_info);
 110   g_object_unref (invocation->connection);
 111   g_object_unref (invocation->message);
 112   g_variant_unref (invocation->parameters);
 113
 114   G_OBJECT_CLASS (g_dbus_method_invocation_parent_class)->finalize (object);
 115 }
 116
 117 static void
 118 g_dbus_method_invocation_class_init (GDBusMethodInvocationClass *klass)
 119 {
 120   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 121
 122   gobject_class->finalize = g_dbus_method_invocation_finalize;
 123 }
 124
 125 static void
 126 g_dbus_method_invocation_init (GDBusMethodInvocation *invocation)
 127 {
 128 }
 129
 130 /**
 131  * g_dbus_method_invocation_get_sender:
 132  * @invocation: A #GDBusMethodInvocation.
 133  *
 134  * Gets the bus name that invoked the method.
 135  *
 136  * Returns: A string. Do not free, it is owned by @invocation.
 137  *
 138  * Since: 2.26
 139  */
 140 const gchar *
 141 g_dbus_method_invocation_get_sender (GDBusMethodInvocation *invocation)
 142 {
 143   g_return_val_if_fail (G_IS_DBUS_METHOD_INVOCATION (invocation), NULL);
 144   return invocation->sender;
 145 }
 146
 147 /**
 148  * g_dbus_method_invocation_get_object_path:
 149  * @invocation: A #GDBusMethodInvocation.
 150  *
 151  * Gets the object path the method was invoked on.
 152  *
 153  * Returns: A string. Do not free, it is owned by @invocation.
 154  *
 155  * Since: 2.26
 156  */
 157 const gchar *
 158 g_dbus_method_invocation_get_object_path (GDBusMethodInvocation *invocation)
 159 {
 160   g_return_val_if_fail (G_IS_DBUS_METHOD_INVOCATION (invocation), NULL);
 161   return invocation->object_path;
 162 }
 163
 164 /**
 165  * g_dbus_method_invocation_get_interface_name:
 166  * @invocation: A #GDBusMethodInvocation.
 167  *
 168  * Gets the name of the D-Bus interface the method was invoked on.
 169  *
 170  * If this method call is a property Get, Set or GetAll call that has
 171  * been redirected to the method call handler then
 172  * "org.freedesktop.DBus.Properties" will be returned.  See
 173  * #GDBusInterfaceVTable for more information.
 174  *
 175  * Returns: A string. Do not free, it is owned by @invocation.
 176  *
 177  * Since: 2.26
 178  */
 179 const gchar *
 180 g_dbus_method_invocation_get_interface_name (GDBusMethodInvocation *invocation)
 181 {
 182   g_return_val_if_fail (G_IS_DBUS_METHOD_INVOCATION (invocation), NULL);
 183   return invocation->interface_name;
 184 }
 185
 186 /**
 187  * g_dbus_method_invocation_get_method_info:
 188  * @invocation: A #GDBusMethodInvocation.
 189  *
 190  * Gets information about the method call, if any.
 191  *
 192  * If this method invocation is a property Get, Set or GetAll call that
 193  * has been redirected to the method call handler then %NULL will be
 194  * returned.  See g_dbus_method_invocation_get_property_info() and
 195  * #GDBusInterfaceVTable for more information.
 196  *
 197  * Returns: A #GDBusMethodInfo or %NULL. Do not free, it is owned by @invocation.
 198  *
 199  * Since: 2.26
 200  */
 201 const GDBusMethodInfo *
 202 g_dbus_method_invocation_get_method_info (GDBusMethodInvocation *invocation)
 203 {
 204   g_return_val_if_fail (G_IS_DBUS_METHOD_INVOCATION (invocation), NULL);
 205   return invocation->method_info;
 206 }
 207
 208 /**
 209  * g_dbus_method_invocation_get_property_info:
 210  * @invocation: A #GDBusMethodInvocation
 211  *
 212  * Gets information about the property that this method call is for, if
 213  * any.
 214  *
 215  * This will only be set in the case of an invocation in response to a
 216  * property Get or Set call that has been directed to the method call
 217  * handler for an object on account of its property_get() or
 218  * property_set() vtable pointers being unset.
 219  *
 220  * See #GDBusInterfaceVTable for more information.
 221  *
 222  * If the call was GetAll, %NULL will be returned.
 223  *
 224  * Returns: (transfer none): a #GDBusPropertyInfo or %NULL
 225  *
 226  * Since: 2.38
 227  */
 228 const GDBusPropertyInfo *
 229 g_dbus_method_invocation_get_property_info (GDBusMethodInvocation *invocation)
 230 {
 231   g_return_val_if_fail (G_IS_DBUS_METHOD_INVOCATION (invocation), NULL);
 232   return invocation->property_info;
 233 }
 234
 235 /**
 236  * g_dbus_method_invocation_get_method_name:
 237  * @invocation: A #GDBusMethodInvocation.
 238  *
 239  * Gets the name of the method that was invoked.
 240  *
 241  * Returns: A string. Do not free, it is owned by @invocation.
 242  *
 243  * Since: 2.26
 244  */
 245 const gchar *
 246 g_dbus_method_invocation_get_method_name (GDBusMethodInvocation *invocation)
 247 {
 248   g_return_val_if_fail (G_IS_DBUS_METHOD_INVOCATION (invocation), NULL);
 249   return invocation->method_name;
 250 }
 251
 252 /**
 253  * g_dbus_method_invocation_get_connection:
 254  * @invocation: A #GDBusMethodInvocation.
 255  *
 256  * Gets the #GDBusConnection the method was invoked on.
 257  *
 258  * Returns: (transfer none):A #GDBusConnection. Do not free, it is owned by @invocation.
 259  *
 260  * Since: 2.26
 261  */
 262 GDBusConnection *
 263 g_dbus_method_invocation_get_connection (GDBusMethodInvocation *invocation)
 264 {
 265   g_return_val_if_fail (G_IS_DBUS_METHOD_INVOCATION (invocation), NULL);
 266   return invocation->connection;
 267 }
 268
 269 /**
 270  * g_dbus_method_invocation_get_message:
 271  * @invocation: A #GDBusMethodInvocation.
 272  *
 273  * Gets the #GDBusMessage for the method invocation. This is useful if
 274  * you need to use low-level protocol features, such as UNIX file
 275  * descriptor passing, that cannot be properly expressed in the
 276  * #GVariant API.
 277  *
 278  * See this [server][gdbus-server] and [client][gdbus-unix-fd-client]
 279  * for an example of how to use this low-level API to send and receive
 280  * UNIX file descriptors.
 281  *
 282  * Returns: (transfer none): #GDBusMessage. Do not free, it is owned by @invocation.
 283  *
 284  * Since: 2.26
 285  */
 286 GDBusMessage *
 287 g_dbus_method_invocation_get_message (GDBusMethodInvocation *invocation)
 288 {
 289   g_return_val_if_fail (G_IS_DBUS_METHOD_INVOCATION (invocation), NULL);
 290   return invocation->message;
 291 }
 292
 293 /**
 294  * g_dbus_method_invocation_get_parameters:
 295  * @invocation: A #GDBusMethodInvocation.
 296  *
 297  * Gets the parameters of the method invocation. If there are no input
 298  * parameters then this will return a GVariant with 0 children rather than NULL.
 299  *
 300  * Returns: (transfer none): A #GVariant tuple. Do not unref this because it is owned by @invocation.
 301  *
 302  * Since: 2.26
 303  */
 304 GVariant *
 305 g_dbus_method_invocation_get_parameters (GDBusMethodInvocation *invocation)
 306 {
 307   g_return_val_if_fail (G_IS_DBUS_METHOD_INVOCATION (invocation), NULL);
 308   return invocation->parameters;
 309 }
 310
 311 /**
 312  * g_dbus_method_invocation_get_user_data: (skip)
 313  * @invocation: A #GDBusMethodInvocation.
 314  *
 315  * Gets the @user_data #gpointer passed to g_dbus_connection_register_object().
 316  *
 317  * Returns: A #gpointer.
 318  *
 319  * Since: 2.26
 320  */
 321 gpointer
 322 g_dbus_method_invocation_get_user_data (GDBusMethodInvocation *invocation)
 323 {
 324   g_return_val_if_fail (G_IS_DBUS_METHOD_INVOCATION (invocation), NULL);
 325   return invocation->user_data;
 326 }
 327
 328 /* < internal >
 329  * _g_dbus_method_invocation_new:
 330  * @sender: (nullable): The bus name that invoked the method or %NULL if @connection is not a bus connection.
 331  * @object_path: The object path the method was invoked on.
 332  * @interface_name: The name of the D-Bus interface the method was invoked on.
 333  * @method_name: The name of the method that was invoked.
 334  * @method_info: (nullable): Information about the method call or %NULL.
 335  * @property_info: (nullable): Information about the property or %NULL.
 336  * @connection: The #GDBusConnection the method was invoked on.
 337  * @message: The D-Bus message as a #GDBusMessage.
 338  * @parameters: The parameters as a #GVariant tuple.
 339  * @user_data: The @user_data #gpointer passed to g_dbus_connection_register_object().
 340  *
 341  * Creates a new #GDBusMethodInvocation object.
 342  *
 343  * Returns: A #GDBusMethodInvocation. Free with g_object_unref().
 344  *
 345  * Since: 2.26
 346  */
 347 GDBusMethodInvocation *
 348 _g_dbus_method_invocation_new (const gchar             *sender,
 349                                const gchar             *object_path,
 350                                const gchar             *interface_name,
 351                                const gchar             *method_name,
 352                                const GDBusMethodInfo   *method_info,
 353                                const GDBusPropertyInfo *property_info,
 354                                GDBusConnection         *connection,
 355                                GDBusMessage            *message,
 356                                GVariant                *parameters,
 357                                gpointer                 user_data)
 358 {
 359   GDBusMethodInvocation *invocation;
 360
 361   g_return_val_if_fail (sender == NULL || g_dbus_is_name (sender), NULL);
 362   g_return_val_if_fail (g_variant_is_object_path (object_path), NULL);
 363   g_return_val_if_fail (interface_name == NULL || g_dbus_is_interface_name (interface_name), NULL);
 364   g_return_val_if_fail (g_dbus_is_member_name (method_name), NULL);
 365   g_return_val_if_fail (G_IS_DBUS_CONNECTION (connection), NULL);
 366   g_return_val_if_fail (G_IS_DBUS_MESSAGE (message), NULL);
 367   g_return_val_if_fail (g_variant_is_of_type (parameters, G_VARIANT_TYPE_TUPLE), NULL);
 368
 369   invocation = G_DBUS_METHOD_INVOCATION (g_object_new (G_TYPE_DBUS_METHOD_INVOCATION, NULL));
 370   invocation->sender = g_strdup (sender);
 371   invocation->object_path = g_strdup (object_path);
 372   invocation->interface_name = g_strdup (interface_name);
 373   invocation->method_name = g_strdup (method_name);
 374   if (method_info)
 375     invocation->method_info = g_dbus_method_info_ref ((GDBusMethodInfo *)method_info);
 376   if (property_info)
 377     invocation->property_info = g_dbus_property_info_ref ((GDBusPropertyInfo *)property_info);
 378   invocation->connection = g_object_ref (connection);
 379   invocation->message = g_object_ref (message);
 380   invocation->parameters = g_variant_ref (parameters);
 381   invocation->user_data = user_data;
 382
 383   return invocation;
 384 }
 385
 386 /* ---------------------------------------------------------------------------------------------------- */
 387
 388 static void
 389 g_dbus_method_invocation_return_value_internal (GDBusMethodInvocation *invocation,
 390                                                 GVariant              *parameters,
 391                                                 GUnixFDList           *fd_list)
 392 {
 393   GDBusMessage *reply;
 394   GError *error;
 395
 396   g_return_if_fail (G_IS_DBUS_METHOD_INVOCATION (invocation));
 397   g_return_if_fail ((parameters == NULL) || g_variant_is_of_type (parameters, G_VARIANT_TYPE_TUPLE));
 398
 399   if (g_dbus_message_get_flags (invocation->message) & G_DBUS_MESSAGE_FLAGS_NO_REPLY_EXPECTED)
 400     {
 401       if (parameters != NULL)
 402         {
 403           g_variant_ref_sink (parameters);
 404           g_variant_unref (parameters);
 405         }
 406       goto out;
 407     }
 408
 409   if (parameters == NULL)
 410     parameters = g_variant_new_tuple (NULL, 0);
 411
 412   /* if we have introspection data, check that the signature of @parameters is correct */
 413   if (invocation->method_info != NULL)
 414     {
 415       GVariantType *type;
 416
 417       type = _g_dbus_compute_complete_signature (invocation->method_info->out_args);
 418
 419       if (!g_variant_is_of_type (parameters, type))
 420         {
 421           gchar *type_string = g_variant_type_dup_string (type);
 422
 423           g_warning ("Type of return value is incorrect: expected '%s', got '%s''",
 424                      type_string, g_variant_get_type_string (parameters));
 425           g_variant_type_free (type);
 426           g_free (type_string);
 427           goto out;
 428         }
 429       g_variant_type_free (type);
 430     }
 431
 432   /* property_info is only non-NULL if set that way from
 433    * GDBusConnection, so this must be the case of async property
 434    * handling on either 'Get', 'Set' or 'GetAll'.
 435    */
 436   if (invocation->property_info != NULL)
 437     {
 438       if (g_str_equal (invocation->method_name, "Get"))
 439         {
 440           GVariant *nested;
 441
 442           if (!g_variant_is_of_type (parameters, G_VARIANT_TYPE ("(v)")))
 443             {
 444               g_warning ("Type of return value for property 'Get' call should be '(v)' but got '%s'",
 445                          g_variant_get_type_string (parameters));
 446               goto out;
 447             }
 448
 449           /* Go deeper and make sure that the value inside of the
 450            * variant matches the property type.
 451            */
 452           g_variant_get (parameters, "(v)", &nested);
 453           if (!g_str_equal (g_variant_get_type_string (nested), invocation->property_info->signature))
 454             {
 455               g_warning ("Value returned from property 'Get' call for '%s' should be '%s' but is '%s'",
 456                          invocation->property_info->name, invocation->property_info->signature,
 457                          g_variant_get_type_string (nested));
 458               g_variant_unref (nested);
 459               goto out;
 460             }
 461           g_variant_unref (nested);
 462         }
 463
 464       else if (g_str_equal (invocation->method_name, "GetAll"))
 465         {
 466           if (!g_variant_is_of_type (parameters, G_VARIANT_TYPE ("(a{sv})")))
 467             {
 468               g_warning ("Type of return value for property 'GetAll' call should be '(a{sv})' but got '%s'",
 469                          g_variant_get_type_string (parameters));
 470               goto out;
 471             }
 472
 473           /* Could iterate the list of properties and make sure that all
 474            * of them are actually on the interface and with the correct
 475            * types, but let's not do that for now...
 476            */
 477         }
 478
 479       else if (g_str_equal (invocation->method_name, "Set"))
 480         {
 481           if (!g_variant_is_of_type (parameters, G_VARIANT_TYPE_UNIT))
 482             {
 483               g_warning ("Type of return value for property 'Set' call should be '()' but got '%s'",
 484                          g_variant_get_type_string (parameters));
 485               goto out;
 486             }
 487         }
 488
 489       else
 490         g_assert_not_reached ();
 491     }
 492
 493   if (G_UNLIKELY (_g_dbus_debug_return ()))
 494     {
 495       _g_dbus_debug_print_lock ();
 496       g_print ("========================================================================\n"
 497                "GDBus-debug:Return:\n"
 498                " >>>> METHOD RETURN\n"
 499                "      in response to %s.%s()\n"
 500                "      on object %s\n"
 501                "      to name %s\n"
 502                "      reply-serial %d\n",
 503                invocation->interface_name, invocation->method_name,
 504                invocation->object_path,
 505                invocation->sender,
 506                g_dbus_message_get_serial (invocation->message));
 507       _g_dbus_debug_print_unlock ();
 508     }
 509
 510   reply = g_dbus_message_new_method_reply (invocation->message);
 511   g_dbus_message_set_body (reply, parameters);
 512
 513 #ifdef G_OS_UNIX
 514   if (fd_list != NULL)
 515     g_dbus_message_set_unix_fd_list (reply, fd_list);
 516 #endif
 517
 518   error = NULL;
 519   if (!g_dbus_connection_send_message (g_dbus_method_invocation_get_connection (invocation), reply, G_DBUS_SEND_MESSAGE_FLAGS_NONE, NULL, &error))
 520     {
 521       if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CLOSED))
 522         g_warning ("Error sending message: %s", error->message);
 523       g_error_free (error);
 524     }
 525   g_object_unref (reply);
 526
 527  out:
 528   g_object_unref (invocation);
 529 }
 530
 531 /**
 532  * g_dbus_method_invocation_return_value:
 533  * @invocation: (transfer full): A #GDBusMethodInvocation.
 534  * @parameters: (nullable): A #GVariant tuple with out parameters for the method or %NULL if not passing any parameters.
 535  *
 536  * Finishes handling a D-Bus method call by returning @parameters.
 537  * If the @parameters GVariant is floating, it is consumed.
 538  *
 539  * It is an error if @parameters is not of the right format: it must be a tuple
 540  * containing the out-parameters of the D-Bus method. Even if the method has a
 541  * single out-parameter, it must be contained in a tuple. If the method has no
 542  * out-parameters, @parameters may be %NULL or an empty tuple.
 543  *
 544  * |[<!-- language="C" -->
 545  * GDBusMethodInvocation *invocation = some_invocation;
 546  * g_autofree gchar *result_string = NULL;
 547  * g_autoptr (GError) error = NULL;
 548  *
 549  * result_string = calculate_result (&error);
 550  *
 551  * if (error != NULL)
 552  *   g_dbus_method_invocation_return_gerror (invocation, error);
 553  * else
 554  *   g_dbus_method_invocation_return_value (invocation,
 555  *                                          g_variant_new ("(s)", result_string));
 556  *
 557  * /<!-- -->* Do not free @invocation here; returning a value does that *<!-- -->/
 558  * ]|
 559  *
 560  * This method will take ownership of @invocation. See
 561  * #GDBusInterfaceVTable for more information about the ownership of
 562  * @invocation.
 563  *
 564  * Since 2.48, if the method call requested for a reply not to be sent
 565  * then this call will sink @parameters and free @invocation, but
 566  * otherwise do nothing (as per the recommendations of the D-Bus
 567  * specification).
 568  *
 569  * Since: 2.26
 570  */
 571 void
 572 g_dbus_method_invocation_return_value (GDBusMethodInvocation *invocation,
 573                                        GVariant              *parameters)
 574 {
 575   g_dbus_method_invocation_return_value_internal (invocation, parameters, NULL);
 576 }
 577
 578 #ifdef G_OS_UNIX
 579 /**
 580  * g_dbus_method_invocation_return_value_with_unix_fd_list:
 581  * @invocation: (transfer full): A #GDBusMethodInvocation.
 582  * @parameters: (nullable): A #GVariant tuple with out parameters for the method or %NULL if not passing any parameters.
 583  * @fd_list: (nullable): A #GUnixFDList or %NULL.
 584  *
 585  * Like g_dbus_method_invocation_return_value() but also takes a #GUnixFDList.
 586  *
 587  * This method is only available on UNIX.
 588  *
 589  * This method will take ownership of @invocation. See
 590  * #GDBusInterfaceVTable for more information about the ownership of
 591  * @invocation.
 592  *
 593  * Since: 2.30
 594  */
 595 void
 596 g_dbus_method_invocation_return_value_with_unix_fd_list (GDBusMethodInvocation *invocation,
 597                                                          GVariant              *parameters,
 598                                                          GUnixFDList           *fd_list)
 599 {
 600   g_dbus_method_invocation_return_value_internal (invocation, parameters, fd_list);
 601 }
 602 #endif
 603
 604 /* ---------------------------------------------------------------------------------------------------- */
 605
 606 /**
 607  * g_dbus_method_invocation_return_error:
 608  * @invocation: (transfer full): A #GDBusMethodInvocation.
 609  * @domain: A #GQuark for the #GError error domain.
 610  * @code: The error code.
 611  * @format: printf()-style format.
 612  * @...: Parameters for @format.
 613  *
 614  * Finishes handling a D-Bus method call by returning an error.
 615  *
 616  * See g_dbus_error_encode_gerror() for details about what error name
 617  * will be returned on the wire. In a nutshell, if the given error is
 618  * registered using g_dbus_error_register_error() the name given
 619  * during registration is used. Otherwise, a name of the form
 620  * `org.gtk.GDBus.UnmappedGError.Quark...` is used. This provides
 621  * transparent mapping of #GError between applications using GDBus.
 622  *
 623  * If you are writing an application intended to be portable,
 624  * always register errors with g_dbus_error_register_error()
 625  * or use g_dbus_method_invocation_return_dbus_error().
 626  *
 627  * This method will take ownership of @invocation. See
 628  * #GDBusInterfaceVTable for more information about the ownership of
 629  * @invocation.
 630  *
 631  * Since 2.48, if the method call requested for a reply not to be sent
 632  * then this call will free @invocation but otherwise do nothing (as per
 633  * the recommendations of the D-Bus specification).
 634  *
 635  * Since: 2.26
 636  */
 637 void
 638 g_dbus_method_invocation_return_error (GDBusMethodInvocation *invocation,
 639                                        GQuark                 domain,
 640                                        gint                   code,
 641                                        const gchar           *format,
 642                                        ...)
 643 {
 644   va_list var_args;
 645
 646   g_return_if_fail (G_IS_DBUS_METHOD_INVOCATION (invocation));
 647   g_return_if_fail (format != NULL);
 648
 649   va_start (var_args, format);
 650   g_dbus_method_invocation_return_error_valist (invocation,
 651                                                 domain,
 652                                                 code,
 653                                                 format,
 654                                                 var_args);
 655   va_end (var_args);
 656 }
 657
 658 /**
 659  * g_dbus_method_invocation_return_error_valist:
 660  * @invocation: (transfer full): A #GDBusMethodInvocation.
 661  * @domain: A #GQuark for the #GError error domain.
 662  * @code: The error code.
 663  * @format: printf()-style format.
 664  * @var_args: #va_list of parameters for @format.
 665  *
 666  * Like g_dbus_method_invocation_return_error() but intended for
 667  * language bindings.
 668  *
 669  * This method will take ownership of @invocation. See
 670  * #GDBusInterfaceVTable for more information about the ownership of
 671  * @invocation.
 672  *
 673  * Since: 2.26
 674  */
 675 void
 676 g_dbus_method_invocation_return_error_valist (GDBusMethodInvocation *invocation,
 677                                               GQuark                 domain,
 678                                               gint                   code,
 679                                               const gchar           *format,
 680                                               va_list                var_args)
 681 {
 682   gchar *literal_message;
 683
 684   g_return_if_fail (G_IS_DBUS_METHOD_INVOCATION (invocation));
 685   g_return_if_fail (format != NULL);
 686
 687   literal_message = g_strdup_vprintf (format, var_args);
 688   g_dbus_method_invocation_return_error_literal (invocation,
 689                                                  domain,
 690                                                  code,
 691                                                  literal_message);
 692   g_free (literal_message);
 693 }
 694
 695 /**
 696  * g_dbus_method_invocation_return_error_literal:
 697  * @invocation: (transfer full): A #GDBusMethodInvocation.
 698  * @domain: A #GQuark for the #GError error domain.
 699  * @code: The error code.
 700  * @message: The error message.
 701  *
 702  * Like g_dbus_method_invocation_return_error() but without printf()-style formatting.
 703  *
 704  * This method will take ownership of @invocation. See
 705  * #GDBusInterfaceVTable for more information about the ownership of
 706  * @invocation.
 707  *
 708  * Since: 2.26
 709  */
 710 void
 711 g_dbus_method_invocation_return_error_literal (GDBusMethodInvocation *invocation,
 712                                                GQuark                 domain,
 713                                                gint                   code,
 714                                                const gchar           *message)
 715 {
 716   GError *error;
 717
 718   g_return_if_fail (G_IS_DBUS_METHOD_INVOCATION (invocation));
 719   g_return_if_fail (message != NULL);
 720
 721   error = g_error_new_literal (domain, code, message);
 722   g_dbus_method_invocation_return_gerror (invocation, error);
 723   g_error_free (error);
 724 }
 725
 726 /**
 727  * g_dbus_method_invocation_return_gerror:
 728  * @invocation: (transfer full): A #GDBusMethodInvocation.
 729  * @error: A #GError.
 730  *
 731  * Like g_dbus_method_invocation_return_error() but takes a #GError
 732  * instead of the error domain, error code and message.
 733  *
 734  * This method will take ownership of @invocation. See
 735  * #GDBusInterfaceVTable for more information about the ownership of
 736  * @invocation.
 737  *
 738  * Since: 2.26
 739  */
 740 void
 741 g_dbus_method_invocation_return_gerror (GDBusMethodInvocation *invocation,
 742                                         const GError          *error)
 743 {
 744   gchar *dbus_error_name;
 745
 746   g_return_if_fail (G_IS_DBUS_METHOD_INVOCATION (invocation));
 747   g_return_if_fail (error != NULL);
 748
 749   dbus_error_name = g_dbus_error_encode_gerror (error);
 750
 751   g_dbus_method_invocation_return_dbus_error (invocation,
 752                                               dbus_error_name,
 753                                               error->message);
 754   g_free (dbus_error_name);
 755 }
 756
 757 /**
 758  * g_dbus_method_invocation_take_error: (skip)
 759  * @invocation: (transfer full): A #GDBusMethodInvocation.
 760  * @error: (transfer full): A #GError.
 761  *
 762  * Like g_dbus_method_invocation_return_gerror() but takes ownership
 763  * of @error so the caller does not need to free it.
 764  *
 765  * This method will take ownership of @invocation. See
 766  * #GDBusInterfaceVTable for more information about the ownership of
 767  * @invocation.
 768  *
 769  * Since: 2.30
 770  */
 771 void
 772 g_dbus_method_invocation_take_error (GDBusMethodInvocation *invocation,
 773                                      GError                *error)
 774 {
 775   g_return_if_fail (G_IS_DBUS_METHOD_INVOCATION (invocation));
 776   g_return_if_fail (error != NULL);
 777   g_dbus_method_invocation_return_gerror (invocation, error);
 778   g_error_free (error);
 779 }
 780
 781 /**
 782  * g_dbus_method_invocation_return_dbus_error:
 783  * @invocation: (transfer full): A #GDBusMethodInvocation.
 784  * @error_name: A valid D-Bus error name.
 785  * @error_message: A valid D-Bus error message.
 786  *
 787  * Finishes handling a D-Bus method call by returning an error.
 788  *
 789  * This method will take ownership of @invocation. See
 790  * #GDBusInterfaceVTable for more information about the ownership of
 791  * @invocation.
 792  *
 793  * Since: 2.26
 794  */
 795 void
 796 g_dbus_method_invocation_return_dbus_error (GDBusMethodInvocation *invocation,
 797                                             const gchar           *error_name,
 798                                             const gchar           *error_message)
 799 {
 800   GDBusMessage *reply;
 801
 802   g_return_if_fail (G_IS_DBUS_METHOD_INVOCATION (invocation));
 803   g_return_if_fail (error_name != NULL && g_dbus_is_name (error_name));
 804   g_return_if_fail (error_message != NULL);
 805
 806   if (g_dbus_message_get_flags (invocation->message) & G_DBUS_MESSAGE_FLAGS_NO_REPLY_EXPECTED)
 807     goto out;
 808
 809   if (G_UNLIKELY (_g_dbus_debug_return ()))
 810     {
 811       _g_dbus_debug_print_lock ();
 812       g_print ("========================================================================\n"
 813                "GDBus-debug:Return:\n"
 814                " >>>> METHOD ERROR %s\n"
 815                "      message '%s'\n"
 816                "      in response to %s.%s()\n"
 817                "      on object %s\n"
 818                "      to name %s\n"
 819                "      reply-serial %d\n",
 820                error_name,
 821                error_message,
 822                invocation->interface_name, invocation->method_name,
 823                invocation->object_path,
 824                invocation->sender,
 825                g_dbus_message_get_serial (invocation->message));
 826       _g_dbus_debug_print_unlock ();
 827     }
 828
 829   reply = g_dbus_message_new_method_error_literal (invocation->message,
 830                                                    error_name,
 831                                                    error_message);
 832   g_dbus_connection_send_message (g_dbus_method_invocation_get_connection (invocation), reply, G_DBUS_SEND_MESSAGE_FLAGS_NONE, NULL, NULL);
 833   g_object_unref (reply);
 834
 835 out:
 836   g_object_unref (invocation);
 837 }