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#include <string.h>
25
26#include "gdbuserror.h"
27#include "gioenums.h"
28#include "gioenumtypes.h"
29#include "gioerror.h"
30#include "gdbusprivate.h"
31
32#include "glibintl.h"
33
34/**
35 * SECTION:gdbuserror
36 * @title: GDBusError
37 * @short_description: Mapping D-Bus errors to and from GError
38 * @include: gio/gio.h
39 *
40 * All facilities that return errors from remote methods (such as
41 * g_dbus_connection_call_sync()) use #GError to represent both D-Bus
42 * errors (e.g. errors returned from the other peer) and locally
43 * in-process generated errors.
44 *
45 * To check if a returned #GError is an error from a remote peer, use
46 * g_dbus_error_is_remote_error(). To get the actual D-Bus error name,
47 * use g_dbus_error_get_remote_error(). Before presenting an error,
48 * always use g_dbus_error_strip_remote_error().
49 *
50 * In addition, facilities used to return errors to a remote peer also
51 * use #GError. See g_dbus_method_invocation_return_error() for
52 * discussion about how the D-Bus error name is set.
53 *
54 * Applications can associate a #GError error domain with a set of D-Bus errors in order to
55 * automatically map from D-Bus errors to #GError and back. This
56 * is typically done in the function returning the #GQuark for the
57 * error domain:
58 * |[<!-- language="C" -->
59 * // foo-bar-error.h:
60 *
61 * #define FOO_BAR_ERROR (foo_bar_error_quark ())
62 * GQuark foo_bar_error_quark (void);
63 *
64 * typedef enum
65 * {
66 * FOO_BAR_ERROR_FAILED,
67 * FOO_BAR_ERROR_ANOTHER_ERROR,
68 * FOO_BAR_ERROR_SOME_THIRD_ERROR,
69 * FOO_BAR_N_ERRORS / *< skip >* /
70 * } FooBarError;
71 *
72 * // foo-bar-error.c:
73 *
74 * static const GDBusErrorEntry foo_bar_error_entries[] =
75 * {
76 * {FOO_BAR_ERROR_FAILED, "org.project.Foo.Bar.Error.Failed"},
77 * {FOO_BAR_ERROR_ANOTHER_ERROR, "org.project.Foo.Bar.Error.AnotherError"},
78 * {FOO_BAR_ERROR_SOME_THIRD_ERROR, "org.project.Foo.Bar.Error.SomeThirdError"},
79 * };
80 *
81 * // Ensure that every error code has an associated D-Bus error name
82 * G_STATIC_ASSERT (G_N_ELEMENTS (foo_bar_error_entries) == FOO_BAR_N_ERRORS);
83 *
84 * GQuark
85 * foo_bar_error_quark (void)
86 * {
87 * static gsize quark = 0;
88 * g_dbus_error_register_error_domain ("foo-bar-error-quark",
89 * &quark,
90 * foo_bar_error_entries,
91 * G_N_ELEMENTS (foo_bar_error_entries));
92 * return (GQuark) quark;
93 * }
94 * ]|
95 * With this setup, a D-Bus peer can transparently pass e.g. %FOO_BAR_ERROR_ANOTHER_ERROR and
96 * other peers will see the D-Bus error name org.project.Foo.Bar.Error.AnotherError.
97 *
98 * If the other peer is using GDBus, and has registered the association with
99 * g_dbus_error_register_error_domain() in advance (e.g. by invoking the %FOO_BAR_ERROR quark
100 * generation itself in the previous example) the peer will see also %FOO_BAR_ERROR_ANOTHER_ERROR instead
101 * of %G_IO_ERROR_DBUS_ERROR. Note that GDBus clients can still recover
102 * org.project.Foo.Bar.Error.AnotherError using g_dbus_error_get_remote_error().
103 *
104 * Note that the %G_DBUS_ERROR error domain is intended only
105 * for returning errors from a remote message bus process. Errors
106 * generated locally in-process by e.g. #GDBusConnection should use the
107 * %G_IO_ERROR domain.
108 */
109
110static const GDBusErrorEntry g_dbus_error_entries[] =
111{
112 {G_DBUS_ERROR_FAILED, "org.freedesktop.DBus.Error.Failed"},
113 {G_DBUS_ERROR_NO_MEMORY, "org.freedesktop.DBus.Error.NoMemory"},
114 {G_DBUS_ERROR_SERVICE_UNKNOWN, "org.freedesktop.DBus.Error.ServiceUnknown"},
115 {G_DBUS_ERROR_NAME_HAS_NO_OWNER, "org.freedesktop.DBus.Error.NameHasNoOwner"},
116 {G_DBUS_ERROR_NO_REPLY, "org.freedesktop.DBus.Error.NoReply"},
117 {G_DBUS_ERROR_IO_ERROR, "org.freedesktop.DBus.Error.IOError"},
118 {G_DBUS_ERROR_BAD_ADDRESS, "org.freedesktop.DBus.Error.BadAddress"},
119 {G_DBUS_ERROR_NOT_SUPPORTED, "org.freedesktop.DBus.Error.NotSupported"},
120 {G_DBUS_ERROR_LIMITS_EXCEEDED, "org.freedesktop.DBus.Error.LimitsExceeded"},
121 {G_DBUS_ERROR_ACCESS_DENIED, "org.freedesktop.DBus.Error.AccessDenied"},
122 {G_DBUS_ERROR_AUTH_FAILED, "org.freedesktop.DBus.Error.AuthFailed"},
123 {G_DBUS_ERROR_NO_SERVER, "org.freedesktop.DBus.Error.NoServer"},
124 {G_DBUS_ERROR_TIMEOUT, "org.freedesktop.DBus.Error.Timeout"},
125 {G_DBUS_ERROR_NO_NETWORK, "org.freedesktop.DBus.Error.NoNetwork"},
126 {G_DBUS_ERROR_ADDRESS_IN_USE, "org.freedesktop.DBus.Error.AddressInUse"},
127 {G_DBUS_ERROR_DISCONNECTED, "org.freedesktop.DBus.Error.Disconnected"},
128 {G_DBUS_ERROR_INVALID_ARGS, "org.freedesktop.DBus.Error.InvalidArgs"},
129 {G_DBUS_ERROR_FILE_NOT_FOUND, "org.freedesktop.DBus.Error.FileNotFound"},
130 {G_DBUS_ERROR_FILE_EXISTS, "org.freedesktop.DBus.Error.FileExists"},
131 {G_DBUS_ERROR_UNKNOWN_METHOD, "org.freedesktop.DBus.Error.UnknownMethod"},
132 {G_DBUS_ERROR_TIMED_OUT, "org.freedesktop.DBus.Error.TimedOut"},
133 {G_DBUS_ERROR_MATCH_RULE_NOT_FOUND, "org.freedesktop.DBus.Error.MatchRuleNotFound"},
134 {G_DBUS_ERROR_MATCH_RULE_INVALID, "org.freedesktop.DBus.Error.MatchRuleInvalid"},
135 {G_DBUS_ERROR_SPAWN_EXEC_FAILED, "org.freedesktop.DBus.Error.Spawn.ExecFailed"},
136 {G_DBUS_ERROR_SPAWN_FORK_FAILED, "org.freedesktop.DBus.Error.Spawn.ForkFailed"},
137 {G_DBUS_ERROR_SPAWN_CHILD_EXITED, "org.freedesktop.DBus.Error.Spawn.ChildExited"},
138 {G_DBUS_ERROR_SPAWN_CHILD_SIGNALED, "org.freedesktop.DBus.Error.Spawn.ChildSignaled"},
139 {G_DBUS_ERROR_SPAWN_FAILED, "org.freedesktop.DBus.Error.Spawn.Failed"},
140 {G_DBUS_ERROR_SPAWN_SETUP_FAILED, "org.freedesktop.DBus.Error.Spawn.FailedToSetup"},
141 {G_DBUS_ERROR_SPAWN_CONFIG_INVALID, "org.freedesktop.DBus.Error.Spawn.ConfigInvalid"},
142 {G_DBUS_ERROR_SPAWN_SERVICE_INVALID, "org.freedesktop.DBus.Error.Spawn.ServiceNotValid"},
143 {G_DBUS_ERROR_SPAWN_SERVICE_NOT_FOUND, "org.freedesktop.DBus.Error.Spawn.ServiceNotFound"},
144 {G_DBUS_ERROR_SPAWN_PERMISSIONS_INVALID, "org.freedesktop.DBus.Error.Spawn.PermissionsInvalid"},
145 {G_DBUS_ERROR_SPAWN_FILE_INVALID, "org.freedesktop.DBus.Error.Spawn.FileInvalid"},
146 {G_DBUS_ERROR_SPAWN_NO_MEMORY, "org.freedesktop.DBus.Error.Spawn.NoMemory"},
147 {G_DBUS_ERROR_UNIX_PROCESS_ID_UNKNOWN, "org.freedesktop.DBus.Error.UnixProcessIdUnknown"},
148 {G_DBUS_ERROR_INVALID_SIGNATURE, "org.freedesktop.DBus.Error.InvalidSignature"},
149 {G_DBUS_ERROR_INVALID_FILE_CONTENT, "org.freedesktop.DBus.Error.InvalidFileContent"},
150 {G_DBUS_ERROR_SELINUX_SECURITY_CONTEXT_UNKNOWN, "org.freedesktop.DBus.Error.SELinuxSecurityContextUnknown"},
151 {G_DBUS_ERROR_ADT_AUDIT_DATA_UNKNOWN, "org.freedesktop.DBus.Error.AdtAuditDataUnknown"},
152 {G_DBUS_ERROR_OBJECT_PATH_IN_USE, "org.freedesktop.DBus.Error.ObjectPathInUse"},
153 {G_DBUS_ERROR_UNKNOWN_OBJECT, "org.freedesktop.DBus.Error.UnknownObject"},
154 {G_DBUS_ERROR_UNKNOWN_INTERFACE, "org.freedesktop.DBus.Error.UnknownInterface"},
155 {G_DBUS_ERROR_UNKNOWN_PROPERTY, "org.freedesktop.DBus.Error.UnknownProperty"},
156 {G_DBUS_ERROR_PROPERTY_READ_ONLY, "org.freedesktop.DBus.Error.PropertyReadOnly"},
157};
158
159GQuark
160g_dbus_error_quark (void)
161{
162 G_STATIC_ASSERT (G_N_ELEMENTS (g_dbus_error_entries) - 1 == G_DBUS_ERROR_PROPERTY_READ_ONLY);
163 static gsize quark = 0;
164 g_dbus_error_register_error_domain (error_domain_quark_name: "g-dbus-error-quark",
165 quark_volatile: &quark,
166 entries: g_dbus_error_entries,
167 G_N_ELEMENTS (g_dbus_error_entries));
168 return (GQuark) quark;
169}
170
171/**
172 * g_dbus_error_register_error_domain:
173 * @error_domain_quark_name: The error domain name.
174 * @quark_volatile: A pointer where to store the #GQuark.
175 * @entries: (array length=num_entries): A pointer to @num_entries #GDBusErrorEntry struct items.
176 * @num_entries: Number of items to register.
177 *
178 * Helper function for associating a #GError error domain with D-Bus error names.
179 *
180 * While @quark_volatile has a `volatile` qualifier, this is a historical
181 * artifact and the argument passed to it should not be `volatile`.
182 *
183 * Since: 2.26
184 */
185void
186g_dbus_error_register_error_domain (const gchar *error_domain_quark_name,
187 volatile gsize *quark_volatile,
188 const GDBusErrorEntry *entries,
189 guint num_entries)
190{
191 gsize *quark;
192
193 g_return_if_fail (error_domain_quark_name != NULL);
194 g_return_if_fail (quark_volatile != NULL);
195 g_return_if_fail (entries != NULL);
196 g_return_if_fail (num_entries > 0);
197
198 /* Drop the volatile qualifier, which should never have been on the argument
199 * in the first place. */
200 quark = (gsize *) quark_volatile;
201
202 if (g_once_init_enter (quark))
203 {
204 guint n;
205 GQuark new_quark;
206
207 new_quark = g_quark_from_static_string (string: error_domain_quark_name);
208
209 for (n = 0; n < num_entries; n++)
210 {
211 g_warn_if_fail (g_dbus_error_register_error (new_quark,
212 entries[n].error_code,
213 entries[n].dbus_error_name));
214 }
215 g_once_init_leave (quark, new_quark);
216 }
217}
218
219static gboolean
220_g_dbus_error_decode_gerror (const gchar *dbus_name,
221 GQuark *out_error_domain,
222 gint *out_error_code)
223{
224 gboolean ret;
225 guint n;
226 GString *s;
227 gchar *domain_quark_string;
228
229 ret = FALSE;
230 s = NULL;
231
232 if (g_str_has_prefix (str: dbus_name, prefix: "org.gtk.GDBus.UnmappedGError.Quark._"))
233 {
234 s = g_string_new (NULL);
235
236 for (n = sizeof "org.gtk.GDBus.UnmappedGError.Quark._" - 1;
237 dbus_name[n] != '.' && dbus_name[n] != '\0';
238 n++)
239 {
240 if (g_ascii_isalnum (dbus_name[n]))
241 {
242 g_string_append_c (s, dbus_name[n]);
243 }
244 else if (dbus_name[n] == '_')
245 {
246 guint nibble_top;
247 guint nibble_bottom;
248
249 n++;
250
251 nibble_top = dbus_name[n];
252 if (nibble_top >= '0' && nibble_top <= '9')
253 nibble_top -= '0';
254 else if (nibble_top >= 'a' && nibble_top <= 'f')
255 nibble_top -= ('a' - 10);
256 else
257 goto not_mapped;
258
259 n++;
260
261 nibble_bottom = dbus_name[n];
262 if (nibble_bottom >= '0' && nibble_bottom <= '9')
263 nibble_bottom -= '0';
264 else if (nibble_bottom >= 'a' && nibble_bottom <= 'f')
265 nibble_bottom -= ('a' - 10);
266 else
267 goto not_mapped;
268
269 g_string_append_c (s, (nibble_top<<4) | nibble_bottom);
270 }
271 else
272 {
273 goto not_mapped;
274 }
275 }
276
277 if (!g_str_has_prefix (str: dbus_name + n, prefix: ".Code"))
278 goto not_mapped;
279
280 domain_quark_string = g_string_free (string: s, FALSE);
281 s = NULL;
282
283 if (out_error_domain != NULL)
284 *out_error_domain = g_quark_from_string (string: domain_quark_string);
285 g_free (mem: domain_quark_string);
286
287 if (out_error_code != NULL)
288 *out_error_code = atoi (nptr: dbus_name + n + sizeof ".Code" - 1);
289
290 ret = TRUE;
291 }
292
293 not_mapped:
294
295 if (s != NULL)
296 g_string_free (string: s, TRUE);
297
298 return ret;
299}
300
301/* ---------------------------------------------------------------------------------------------------- */
302
303typedef struct
304{
305 GQuark error_domain;
306 gint error_code;
307} QuarkCodePair;
308
309static guint
310quark_code_pair_hash_func (const QuarkCodePair *pair)
311{
312 gint val;
313 val = pair->error_domain + pair->error_code;
314 return g_int_hash (v: &val);
315}
316
317static gboolean
318quark_code_pair_equal_func (const QuarkCodePair *a,
319 const QuarkCodePair *b)
320{
321 return (a->error_domain == b->error_domain) && (a->error_code == b->error_code);
322}
323
324typedef struct
325{
326 QuarkCodePair pair;
327 gchar *dbus_error_name;
328} RegisteredError;
329
330static void
331registered_error_free (RegisteredError *re)
332{
333 g_free (mem: re->dbus_error_name);
334 g_free (mem: re);
335}
336
337G_LOCK_DEFINE_STATIC (error_lock);
338
339/* maps from QuarkCodePair* -> RegisteredError* */
340static GHashTable *quark_code_pair_to_re = NULL;
341
342/* maps from gchar* -> RegisteredError* */
343static GHashTable *dbus_error_name_to_re = NULL;
344
345/**
346 * g_dbus_error_register_error:
347 * @error_domain: A #GQuark for an error domain.
348 * @error_code: An error code.
349 * @dbus_error_name: A D-Bus error name.
350 *
351 * Creates an association to map between @dbus_error_name and
352 * #GErrors specified by @error_domain and @error_code.
353 *
354 * This is typically done in the routine that returns the #GQuark for
355 * an error domain.
356 *
357 * Returns: %TRUE if the association was created, %FALSE if it already
358 * exists.
359 *
360 * Since: 2.26
361 */
362gboolean
363g_dbus_error_register_error (GQuark error_domain,
364 gint error_code,
365 const gchar *dbus_error_name)
366{
367 gboolean ret;
368 QuarkCodePair pair;
369 RegisteredError *re;
370
371 g_return_val_if_fail (dbus_error_name != NULL, FALSE);
372
373 ret = FALSE;
374
375 G_LOCK (error_lock);
376
377 if (quark_code_pair_to_re == NULL)
378 {
379 g_assert (dbus_error_name_to_re == NULL); /* check invariant */
380 quark_code_pair_to_re = g_hash_table_new (hash_func: (GHashFunc) quark_code_pair_hash_func,
381 key_equal_func: (GEqualFunc) quark_code_pair_equal_func);
382 dbus_error_name_to_re = g_hash_table_new_full (hash_func: g_str_hash,
383 key_equal_func: g_str_equal,
384 NULL,
385 value_destroy_func: (GDestroyNotify) registered_error_free);
386 }
387
388 if (g_hash_table_lookup (hash_table: dbus_error_name_to_re, key: dbus_error_name) != NULL)
389 goto out;
390
391 pair.error_domain = error_domain;
392 pair.error_code = error_code;
393
394 if (g_hash_table_lookup (hash_table: quark_code_pair_to_re, key: &pair) != NULL)
395 goto out;
396
397 re = g_new0 (RegisteredError, 1);
398 re->pair = pair;
399 re->dbus_error_name = g_strdup (str: dbus_error_name);
400
401 g_hash_table_insert (hash_table: quark_code_pair_to_re, key: &(re->pair), value: re);
402 g_hash_table_insert (hash_table: dbus_error_name_to_re, key: re->dbus_error_name, value: re);
403
404 ret = TRUE;
405
406 out:
407 G_UNLOCK (error_lock);
408 return ret;
409}
410
411/**
412 * g_dbus_error_unregister_error:
413 * @error_domain: A #GQuark for an error domain.
414 * @error_code: An error code.
415 * @dbus_error_name: A D-Bus error name.
416 *
417 * Destroys an association previously set up with g_dbus_error_register_error().
418 *
419 * Returns: %TRUE if the association was destroyed, %FALSE if it wasn't found.
420 *
421 * Since: 2.26
422 */
423gboolean
424g_dbus_error_unregister_error (GQuark error_domain,
425 gint error_code,
426 const gchar *dbus_error_name)
427{
428 gboolean ret;
429 RegisteredError *re;
430 guint hash_size;
431
432 g_return_val_if_fail (dbus_error_name != NULL, FALSE);
433
434 ret = FALSE;
435
436 G_LOCK (error_lock);
437
438 if (dbus_error_name_to_re == NULL)
439 {
440 g_assert (quark_code_pair_to_re == NULL); /* check invariant */
441 goto out;
442 }
443
444 re = g_hash_table_lookup (hash_table: dbus_error_name_to_re, key: dbus_error_name);
445 if (re == NULL)
446 {
447 QuarkCodePair pair;
448 pair.error_domain = error_domain;
449 pair.error_code = error_code;
450 g_warn_if_fail (g_hash_table_lookup (quark_code_pair_to_re, &pair) == NULL); /* check invariant */
451 goto out;
452 }
453
454 ret = TRUE;
455
456 g_warn_if_fail (g_hash_table_lookup (quark_code_pair_to_re, &(re->pair)) == re); /* check invariant */
457
458 g_warn_if_fail (g_hash_table_remove (quark_code_pair_to_re, &(re->pair)));
459 g_warn_if_fail (g_hash_table_remove (dbus_error_name_to_re, re->dbus_error_name));
460
461 /* destroy hashes if empty */
462 hash_size = g_hash_table_size (hash_table: dbus_error_name_to_re);
463 if (hash_size == 0)
464 {
465 g_warn_if_fail (g_hash_table_size (quark_code_pair_to_re) == 0); /* check invariant */
466
467 g_hash_table_unref (hash_table: dbus_error_name_to_re);
468 dbus_error_name_to_re = NULL;
469 g_hash_table_unref (hash_table: quark_code_pair_to_re);
470 quark_code_pair_to_re = NULL;
471 }
472 else
473 {
474 g_warn_if_fail (g_hash_table_size (quark_code_pair_to_re) == hash_size); /* check invariant */
475 }
476
477 out:
478 G_UNLOCK (error_lock);
479 return ret;
480}
481
482/* ---------------------------------------------------------------------------------------------------- */
483
484/**
485 * g_dbus_error_is_remote_error:
486 * @error: A #GError.
487 *
488 * Checks if @error represents an error received via D-Bus from a remote peer. If so,
489 * use g_dbus_error_get_remote_error() to get the name of the error.
490 *
491 * Returns: %TRUE if @error represents an error from a remote peer,
492 * %FALSE otherwise.
493 *
494 * Since: 2.26
495 */
496gboolean
497g_dbus_error_is_remote_error (const GError *error)
498{
499 g_return_val_if_fail (error != NULL, FALSE);
500 return g_str_has_prefix (str: error->message, prefix: "GDBus.Error:");
501}
502
503
504/**
505 * g_dbus_error_get_remote_error:
506 * @error: a #GError
507 *
508 * Gets the D-Bus error name used for @error, if any.
509 *
510 * This function is guaranteed to return a D-Bus error name for all
511 * #GErrors returned from functions handling remote method calls
512 * (e.g. g_dbus_connection_call_finish()) unless
513 * g_dbus_error_strip_remote_error() has been used on @error.
514 *
515 * Returns: (nullable) (transfer full): an allocated string or %NULL if the
516 * D-Bus error name could not be found. Free with g_free().
517 *
518 * Since: 2.26
519 */
520gchar *
521g_dbus_error_get_remote_error (const GError *error)
522{
523 RegisteredError *re;
524 gchar *ret;
525
526 g_return_val_if_fail (error != NULL, NULL);
527
528 /* Ensure that e.g. G_DBUS_ERROR is registered using g_dbus_error_register_error() */
529 _g_dbus_initialize ();
530
531 ret = NULL;
532
533 G_LOCK (error_lock);
534
535 re = NULL;
536 if (quark_code_pair_to_re != NULL)
537 {
538 QuarkCodePair pair;
539 pair.error_domain = error->domain;
540 pair.error_code = error->code;
541 g_assert (dbus_error_name_to_re != NULL); /* check invariant */
542 re = g_hash_table_lookup (hash_table: quark_code_pair_to_re, key: &pair);
543 }
544
545 if (re != NULL)
546 {
547 ret = g_strdup (str: re->dbus_error_name);
548 }
549 else
550 {
551 if (g_str_has_prefix (str: error->message, prefix: "GDBus.Error:"))
552 {
553 const gchar *begin;
554 const gchar *end;
555 begin = error->message + sizeof ("GDBus.Error:") -1;
556 end = strstr (haystack: begin, needle: ":");
557 if (end != NULL && end[1] == ' ')
558 {
559 ret = g_strndup (str: begin, n: end - begin);
560 }
561 }
562 }
563
564 G_UNLOCK (error_lock);
565
566 return ret;
567}
568
569/* ---------------------------------------------------------------------------------------------------- */
570
571/**
572 * g_dbus_error_new_for_dbus_error:
573 * @dbus_error_name: D-Bus error name.
574 * @dbus_error_message: D-Bus error message.
575 *
576 * Creates a #GError based on the contents of @dbus_error_name and
577 * @dbus_error_message.
578 *
579 * Errors registered with g_dbus_error_register_error() will be looked
580 * up using @dbus_error_name and if a match is found, the error domain
581 * and code is used. Applications can use g_dbus_error_get_remote_error()
582 * to recover @dbus_error_name.
583 *
584 * If a match against a registered error is not found and the D-Bus
585 * error name is in a form as returned by g_dbus_error_encode_gerror()
586 * the error domain and code encoded in the name is used to
587 * create the #GError. Also, @dbus_error_name is added to the error message
588 * such that it can be recovered with g_dbus_error_get_remote_error().
589 *
590 * Otherwise, a #GError with the error code %G_IO_ERROR_DBUS_ERROR
591 * in the #G_IO_ERROR error domain is returned. Also, @dbus_error_name is
592 * added to the error message such that it can be recovered with
593 * g_dbus_error_get_remote_error().
594 *
595 * In all three cases, @dbus_error_name can always be recovered from the
596 * returned #GError using the g_dbus_error_get_remote_error() function
597 * (unless g_dbus_error_strip_remote_error() hasn't been used on the returned error).
598 *
599 * This function is typically only used in object mappings to prepare
600 * #GError instances for applications. Regular applications should not use
601 * it.
602 *
603 * Returns: (transfer full): An allocated #GError. Free with g_error_free().
604 *
605 * Since: 2.26
606 */
607GError *
608g_dbus_error_new_for_dbus_error (const gchar *dbus_error_name,
609 const gchar *dbus_error_message)
610{
611 GError *error;
612 RegisteredError *re;
613
614 g_return_val_if_fail (dbus_error_name != NULL, NULL);
615 g_return_val_if_fail (dbus_error_message != NULL, NULL);
616
617 /* Ensure that e.g. G_DBUS_ERROR is registered using g_dbus_error_register_error() */
618 _g_dbus_initialize ();
619
620 G_LOCK (error_lock);
621
622 re = NULL;
623 if (dbus_error_name_to_re != NULL)
624 {
625 g_assert (quark_code_pair_to_re != NULL); /* check invariant */
626 re = g_hash_table_lookup (hash_table: dbus_error_name_to_re, key: dbus_error_name);
627 }
628
629 if (re != NULL)
630 {
631 error = g_error_new (domain: re->pair.error_domain,
632 code: re->pair.error_code,
633 format: "GDBus.Error:%s: %s",
634 dbus_error_name,
635 dbus_error_message);
636 }
637 else
638 {
639 GQuark error_domain = 0;
640 gint error_code = 0;
641
642 if (_g_dbus_error_decode_gerror (dbus_name: dbus_error_name,
643 out_error_domain: &error_domain,
644 out_error_code: &error_code))
645 {
646 error = g_error_new (domain: error_domain,
647 code: error_code,
648 format: "GDBus.Error:%s: %s",
649 dbus_error_name,
650 dbus_error_message);
651 }
652 else
653 {
654 error = g_error_new (G_IO_ERROR,
655 code: G_IO_ERROR_DBUS_ERROR,
656 format: "GDBus.Error:%s: %s",
657 dbus_error_name,
658 dbus_error_message);
659 }
660 }
661
662 G_UNLOCK (error_lock);
663 return error;
664}
665
666/**
667 * g_dbus_error_set_dbus_error:
668 * @error: A pointer to a #GError or %NULL.
669 * @dbus_error_name: D-Bus error name.
670 * @dbus_error_message: D-Bus error message.
671 * @format: (nullable): printf()-style format to prepend to @dbus_error_message or %NULL.
672 * @...: Arguments for @format.
673 *
674 * Does nothing if @error is %NULL. Otherwise sets *@error to
675 * a new #GError created with g_dbus_error_new_for_dbus_error()
676 * with @dbus_error_message prepend with @format (unless %NULL).
677 *
678 * Since: 2.26
679 */
680void
681g_dbus_error_set_dbus_error (GError **error,
682 const gchar *dbus_error_name,
683 const gchar *dbus_error_message,
684 const gchar *format,
685 ...)
686{
687 g_return_if_fail (error == NULL || *error == NULL);
688 g_return_if_fail (dbus_error_name != NULL);
689 g_return_if_fail (dbus_error_message != NULL);
690
691 if (error == NULL)
692 return;
693
694 if (format == NULL)
695 {
696 *error = g_dbus_error_new_for_dbus_error (dbus_error_name, dbus_error_message);
697 }
698 else
699 {
700 va_list var_args;
701 va_start (var_args, format);
702 g_dbus_error_set_dbus_error_valist (error,
703 dbus_error_name,
704 dbus_error_message,
705 format,
706 var_args);
707 va_end (var_args);
708 }
709}
710
711/**
712 * g_dbus_error_set_dbus_error_valist:
713 * @error: A pointer to a #GError or %NULL.
714 * @dbus_error_name: D-Bus error name.
715 * @dbus_error_message: D-Bus error message.
716 * @format: (nullable): printf()-style format to prepend to @dbus_error_message or %NULL.
717 * @var_args: Arguments for @format.
718 *
719 * Like g_dbus_error_set_dbus_error() but intended for language bindings.
720 *
721 * Since: 2.26
722 */
723void
724g_dbus_error_set_dbus_error_valist (GError **error,
725 const gchar *dbus_error_name,
726 const gchar *dbus_error_message,
727 const gchar *format,
728 va_list var_args)
729{
730 g_return_if_fail (error == NULL || *error == NULL);
731 g_return_if_fail (dbus_error_name != NULL);
732 g_return_if_fail (dbus_error_message != NULL);
733
734 if (error == NULL)
735 return;
736
737 if (format != NULL)
738 {
739 gchar *message;
740 gchar *s;
741 message = g_strdup_vprintf (format, args: var_args);
742 s = g_strdup_printf (format: "%s: %s", message, dbus_error_message);
743 *error = g_dbus_error_new_for_dbus_error (dbus_error_name, dbus_error_message: s);
744 g_free (mem: s);
745 g_free (mem: message);
746 }
747 else
748 {
749 *error = g_dbus_error_new_for_dbus_error (dbus_error_name, dbus_error_message);
750 }
751}
752
753/**
754 * g_dbus_error_strip_remote_error:
755 * @error: A #GError.
756 *
757 * Looks for extra information in the error message used to recover
758 * the D-Bus error name and strips it if found. If stripped, the
759 * message field in @error will correspond exactly to what was
760 * received on the wire.
761 *
762 * This is typically used when presenting errors to the end user.
763 *
764 * Returns: %TRUE if information was stripped, %FALSE otherwise.
765 *
766 * Since: 2.26
767 */
768gboolean
769g_dbus_error_strip_remote_error (GError *error)
770{
771 gboolean ret;
772
773 g_return_val_if_fail (error != NULL, FALSE);
774
775 ret = FALSE;
776
777 if (g_str_has_prefix (str: error->message, prefix: "GDBus.Error:"))
778 {
779 const gchar *begin;
780 const gchar *end;
781 gchar *new_message;
782
783 begin = error->message + sizeof ("GDBus.Error:") -1;
784 end = strstr (haystack: begin, needle: ":");
785 if (end != NULL && end[1] == ' ')
786 {
787 new_message = g_strdup (str: end + 2);
788 g_free (mem: error->message);
789 error->message = new_message;
790 ret = TRUE;
791 }
792 }
793
794 return ret;
795}
796
797/**
798 * g_dbus_error_encode_gerror:
799 * @error: A #GError.
800 *
801 * Creates a D-Bus error name to use for @error. If @error matches
802 * a registered error (cf. g_dbus_error_register_error()), the corresponding
803 * D-Bus error name will be returned.
804 *
805 * Otherwise the a name of the form
806 * `org.gtk.GDBus.UnmappedGError.Quark._ESCAPED_QUARK_NAME.Code_ERROR_CODE`
807 * will be used. This allows other GDBus applications to map the error
808 * on the wire back to a #GError using g_dbus_error_new_for_dbus_error().
809 *
810 * This function is typically only used in object mappings to put a
811 * #GError on the wire. Regular applications should not use it.
812 *
813 * Returns: (transfer full) (not nullable): A D-Bus error name (never %NULL).
814 * Free with g_free().
815 *
816 * Since: 2.26
817 */
818gchar *
819g_dbus_error_encode_gerror (const GError *error)
820{
821 RegisteredError *re;
822 gchar *error_name;
823
824 g_return_val_if_fail (error != NULL, NULL);
825
826 /* Ensure that e.g. G_DBUS_ERROR is registered using g_dbus_error_register_error() */
827 _g_dbus_initialize ();
828
829 error_name = NULL;
830
831 G_LOCK (error_lock);
832 re = NULL;
833 if (quark_code_pair_to_re != NULL)
834 {
835 QuarkCodePair pair;
836 pair.error_domain = error->domain;
837 pair.error_code = error->code;
838 g_assert (dbus_error_name_to_re != NULL); /* check invariant */
839 re = g_hash_table_lookup (hash_table: quark_code_pair_to_re, key: &pair);
840 }
841 if (re != NULL)
842 {
843 error_name = g_strdup (str: re->dbus_error_name);
844 G_UNLOCK (error_lock);
845 }
846 else
847 {
848 const gchar *domain_as_string;
849 GString *s;
850 guint n;
851
852 G_UNLOCK (error_lock);
853
854 /* We can't make a lot of assumptions about what domain_as_string
855 * looks like and D-Bus is extremely picky about error names so
856 * hex-encode it for transport across the wire.
857 */
858 domain_as_string = g_quark_to_string (quark: error->domain);
859
860 /* 0 is not a domain; neither are non-quark integers */
861 g_return_val_if_fail (domain_as_string != NULL, NULL);
862
863 s = g_string_new (init: "org.gtk.GDBus.UnmappedGError.Quark._");
864 for (n = 0; domain_as_string[n] != 0; n++)
865 {
866 gint c = domain_as_string[n];
867 if (g_ascii_isalnum (c))
868 {
869 g_string_append_c (s, c);
870 }
871 else
872 {
873 guint nibble_top;
874 guint nibble_bottom;
875 g_string_append_c (s, '_');
876 nibble_top = ((int) domain_as_string[n]) >> 4;
877 nibble_bottom = ((int) domain_as_string[n]) & 0x0f;
878 if (nibble_top < 10)
879 nibble_top += '0';
880 else
881 nibble_top += 'a' - 10;
882 if (nibble_bottom < 10)
883 nibble_bottom += '0';
884 else
885 nibble_bottom += 'a' - 10;
886 g_string_append_c (s, nibble_top);
887 g_string_append_c (s, nibble_bottom);
888 }
889 }
890 g_string_append_printf (string: s, format: ".Code%d", error->code);
891 error_name = g_string_free (string: s, FALSE);
892 }
893
894 return error_name;
895}
896

source code of gtk/subprojects/glib/gio/gdbuserror.c