1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
3 /* GIO - GLib Input, Output and Streaming Library
5 * Copyright (C) 2008 Red Hat, Inc.
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General
18 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
25 #include "gresolver.h"
26 #include "gnetworkingprivate.h"
27 #include "gasyncresult.h"
28 #include "ginetaddress.h"
30 #include "gsrvtarget.h"
31 #include "gthreadedresolver.h"
42 * @short_description: Asynchronous and cancellable DNS resolver
45 * #GResolver provides cancellable synchronous and asynchronous DNS
46 * resolution, for hostnames (g_resolver_lookup_by_address(),
47 * g_resolver_lookup_by_name() and their async variants) and SRV
48 * (service) records (g_resolver_lookup_service()).
50 * #GNetworkAddress and #GNetworkService provide wrappers around
51 * #GResolver functionality that also implement #GSocketConnectable,
52 * making it easy to connect to a remote host/service.
60 static guint signals[LAST_SIGNAL] = { 0 };
62 struct _GResolverPrivate {
64 time_t resolv_conf_timestamp;
73 * The object that handles DNS resolution. Use g_resolver_get_default()
74 * to get the default resolver.
76 * This is an abstract type; subclasses of it implement different resolvers for
77 * different platforms and situations.
79 G_DEFINE_ABSTRACT_TYPE_WITH_CODE (GResolver, g_resolver, G_TYPE_OBJECT,
80 G_ADD_PRIVATE (GResolver)
81 g_networking_init ();)
84 srv_records_to_targets (GList *records)
86 const gchar *hostname;
87 guint16 port, priority, weight;
91 for (l = records; l != NULL; l = g_list_next (l))
93 g_variant_get (l->data, "(qqq&s)", &priority, &weight, &port, &hostname);
94 target = g_srv_target_new (hostname, port, priority, weight);
95 g_variant_unref (l->data);
99 return g_srv_target_list_sort (records);
103 g_resolver_real_lookup_service (GResolver *resolver,
105 GCancellable *cancellable,
110 records = G_RESOLVER_GET_CLASS (resolver)->lookup_records (resolver,
112 G_RESOLVER_RECORD_SRV,
116 return srv_records_to_targets (records);
120 g_resolver_real_lookup_service_async (GResolver *resolver,
122 GCancellable *cancellable,
123 GAsyncReadyCallback callback,
126 G_RESOLVER_GET_CLASS (resolver)->lookup_records_async (resolver,
128 G_RESOLVER_RECORD_SRV,
135 g_resolver_real_lookup_service_finish (GResolver *resolver,
136 GAsyncResult *result,
141 records = G_RESOLVER_GET_CLASS (resolver)->lookup_records_finish (resolver,
145 return srv_records_to_targets (records);
149 g_resolver_class_init (GResolverClass *resolver_class)
151 /* Automatically pass these over to the lookup_records methods */
152 resolver_class->lookup_service = g_resolver_real_lookup_service;
153 resolver_class->lookup_service_async = g_resolver_real_lookup_service_async;
154 resolver_class->lookup_service_finish = g_resolver_real_lookup_service_finish;
158 * @resolver: a #GResolver
160 * Emitted when the resolver notices that the system resolver
161 * configuration has changed.
164 g_signal_new (I_("reload"),
167 G_STRUCT_OFFSET (GResolverClass, reload),
169 g_cclosure_marshal_VOID__VOID,
174 g_resolver_init (GResolver *resolver)
180 resolver->priv = g_resolver_get_instance_private (resolver);
183 if (stat (_PATH_RESCONF, &st) == 0)
184 resolver->priv->resolv_conf_timestamp = st.st_mtime;
188 static GResolver *default_resolver;
191 * g_resolver_get_default:
193 * Gets the default #GResolver. You should unref it when you are done
194 * with it. #GResolver may use its reference count as a hint about how
195 * many threads it should allocate for concurrent DNS resolutions.
197 * Returns: (transfer full): the default #GResolver.
202 g_resolver_get_default (void)
204 if (!default_resolver)
205 default_resolver = g_object_new (G_TYPE_THREADED_RESOLVER, NULL);
207 return g_object_ref (default_resolver);
211 * g_resolver_set_default:
212 * @resolver: the new default #GResolver
214 * Sets @resolver to be the application's default resolver (reffing
215 * @resolver, and unreffing the previous default resolver, if any).
216 * Future calls to g_resolver_get_default() will return this resolver.
218 * This can be used if an application wants to perform any sort of DNS
219 * caching or "pinning"; it can implement its own #GResolver that
220 * calls the original default resolver for DNS operations, and
221 * implements its own cache policies on top of that, and then set
222 * itself as the default resolver for all later code to use.
227 g_resolver_set_default (GResolver *resolver)
229 if (default_resolver)
230 g_object_unref (default_resolver);
231 default_resolver = g_object_ref (resolver);
234 /* Bionic has res_init() but it's not in any header */
240 g_resolver_maybe_reload (GResolver *resolver)
245 if (stat (_PATH_RESCONF, &st) == 0)
247 if (st.st_mtime != resolver->priv->resolv_conf_timestamp)
249 resolver->priv->resolv_conf_timestamp = st.st_mtime;
253 g_signal_emit (resolver, signals[RELOAD], 0);
259 /* filter out duplicates, cf. https://bugzilla.gnome.org/show_bug.cgi?id=631379 */
261 remove_duplicates (GList *addrs)
267 /* TODO: if this is too slow (it's O(n^2) but n is typically really
268 * small), we can do something more clever but note that we must not
269 * change the order of elements...
271 for (l = addrs; l != NULL; l = l->next)
273 GInetAddress *address = G_INET_ADDRESS (l->data);
274 for (ll = l->next; ll != NULL; ll = lll)
276 GInetAddress *other_address = G_INET_ADDRESS (ll->data);
278 if (g_inet_address_equal (address, other_address))
280 g_object_unref (other_address);
281 /* we never return the first element */
282 g_warn_if_fail (g_list_delete_link (addrs, ll) == addrs);
288 /* Note that this does not follow the "FALSE means @error is set"
289 * convention. The return value tells the caller whether it should
290 * return @addrs and @error to the caller right away, or if it should
291 * continue and trying to resolve the name as a hostname.
294 handle_ip_address (const char *hostname,
301 struct in_addr ip4addr;
304 addr = g_inet_address_new_from_string (hostname);
307 *addrs = g_list_append (NULL, addr);
315 /* Reject IPv6 addresses that have brackets ('[' or ']') and/or port numbers,
316 * as no valid addresses should contain these at this point.
317 * Non-standard IPv4 addresses would be rejected during the call to
318 * getaddrinfo() later.
320 if (strrchr (hostname, '[') != NULL ||
321 strrchr (hostname, ']') != NULL)
324 /* Reject non-standard IPv4 numbers-and-dots addresses.
325 * g_inet_address_new_from_string() will have accepted any "real" IP
326 * address, so if inet_aton() succeeds, then it's an address we want
329 if (inet_aton (hostname, &ip4addr))
332 g_set_error (error, G_RESOLVER_ERROR, G_RESOLVER_ERROR_NOT_FOUND,
333 _("Error resolving '%s': %s"),
334 hostname, gai_strerror (EAI_NONAME));
342 * g_resolver_lookup_by_name:
343 * @resolver: a #GResolver
344 * @hostname: the hostname to look up
345 * @cancellable: (allow-none): a #GCancellable, or %NULL
346 * @error: return location for a #GError, or %NULL
348 * Synchronously resolves @hostname to determine its associated IP
349 * address(es). @hostname may be an ASCII-only or UTF-8 hostname, or
350 * the textual form of an IP address (in which case this just becomes
351 * a wrapper around g_inet_address_new_from_string()).
353 * On success, g_resolver_lookup_by_name() will return a non-empty #GList of
354 * #GInetAddress, sorted in order of preference and guaranteed to not
355 * contain duplicates. That is, if using the result to connect to
356 * @hostname, you should attempt to connect to the first address
357 * first, then the second if the first fails, etc. If you are using
358 * the result to listen on a socket, it is appropriate to add each
359 * result using e.g. g_socket_listener_add_address().
361 * If the DNS resolution fails, @error (if non-%NULL) will be set to a
362 * value from #GResolverError and %NULL will be returned.
364 * If @cancellable is non-%NULL, it can be used to cancel the
365 * operation, in which case @error (if non-%NULL) will be set to
366 * %G_IO_ERROR_CANCELLED.
368 * If you are planning to connect to a socket on the resolved IP
369 * address, it may be easier to create a #GNetworkAddress and use its
370 * #GSocketConnectable interface.
372 * Returns: (element-type GInetAddress) (transfer full): a non-empty #GList
373 * of #GInetAddress, or %NULL on error. You
374 * must unref each of the addresses and free the list when you are
375 * done with it. (You can use g_resolver_free_addresses() to do this.)
380 g_resolver_lookup_by_name (GResolver *resolver,
381 const gchar *hostname,
382 GCancellable *cancellable,
386 gchar *ascii_hostname = NULL;
388 g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
389 g_return_val_if_fail (hostname != NULL, NULL);
391 /* Check if @hostname is just an IP address */
392 if (handle_ip_address (hostname, &addrs, error))
395 if (g_hostname_is_non_ascii (hostname))
396 hostname = ascii_hostname = g_hostname_to_ascii (hostname);
398 g_resolver_maybe_reload (resolver);
399 addrs = G_RESOLVER_GET_CLASS (resolver)->
400 lookup_by_name (resolver, hostname, cancellable, error);
402 remove_duplicates (addrs);
404 g_free (ascii_hostname);
409 * g_resolver_lookup_by_name_async:
410 * @resolver: a #GResolver
411 * @hostname: the hostname to look up the address of
412 * @cancellable: (allow-none): a #GCancellable, or %NULL
413 * @callback: (scope async): callback to call after resolution completes
414 * @user_data: (closure): data for @callback
416 * Begins asynchronously resolving @hostname to determine its
417 * associated IP address(es), and eventually calls @callback, which
418 * must call g_resolver_lookup_by_name_finish() to get the result.
419 * See g_resolver_lookup_by_name() for more details.
424 g_resolver_lookup_by_name_async (GResolver *resolver,
425 const gchar *hostname,
426 GCancellable *cancellable,
427 GAsyncReadyCallback callback,
430 gchar *ascii_hostname = NULL;
432 GError *error = NULL;
434 g_return_if_fail (G_IS_RESOLVER (resolver));
435 g_return_if_fail (hostname != NULL);
437 /* Check if @hostname is just an IP address */
438 if (handle_ip_address (hostname, &addrs, &error))
442 task = g_task_new (resolver, cancellable, callback, user_data);
443 g_task_set_source_tag (task, g_resolver_lookup_by_name_async);
445 g_task_return_pointer (task, addrs, (GDestroyNotify) g_resolver_free_addresses);
447 g_task_return_error (task, error);
448 g_object_unref (task);
452 if (g_hostname_is_non_ascii (hostname))
453 hostname = ascii_hostname = g_hostname_to_ascii (hostname);
455 g_resolver_maybe_reload (resolver);
456 G_RESOLVER_GET_CLASS (resolver)->
457 lookup_by_name_async (resolver, hostname, cancellable, callback, user_data);
459 g_free (ascii_hostname);
463 * g_resolver_lookup_by_name_finish:
464 * @resolver: a #GResolver
465 * @result: the result passed to your #GAsyncReadyCallback
466 * @error: return location for a #GError, or %NULL
468 * Retrieves the result of a call to
469 * g_resolver_lookup_by_name_async().
471 * If the DNS resolution failed, @error (if non-%NULL) will be set to
472 * a value from #GResolverError. If the operation was cancelled,
473 * @error will be set to %G_IO_ERROR_CANCELLED.
475 * Returns: (element-type GInetAddress) (transfer full): a #GList
476 * of #GInetAddress, or %NULL on error. See g_resolver_lookup_by_name()
482 g_resolver_lookup_by_name_finish (GResolver *resolver,
483 GAsyncResult *result,
488 g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
490 if (g_async_result_legacy_propagate_error (result, error))
492 else if (g_async_result_is_tagged (result, g_resolver_lookup_by_name_async))
494 /* Handle the stringified-IP-addr case */
495 return g_task_propagate_pointer (G_TASK (result), error);
498 addrs = G_RESOLVER_GET_CLASS (resolver)->
499 lookup_by_name_finish (resolver, result, error);
501 remove_duplicates (addrs);
507 * g_resolver_free_addresses: (skip)
508 * @addresses: a #GList of #GInetAddress
510 * Frees @addresses (which should be the return value from
511 * g_resolver_lookup_by_name() or g_resolver_lookup_by_name_finish()).
512 * (This is a convenience method; you can also simply free the results
518 g_resolver_free_addresses (GList *addresses)
522 for (a = addresses; a; a = a->next)
523 g_object_unref (a->data);
524 g_list_free (addresses);
528 * g_resolver_lookup_by_address:
529 * @resolver: a #GResolver
530 * @address: the address to reverse-resolve
531 * @cancellable: (allow-none): a #GCancellable, or %NULL
532 * @error: return location for a #GError, or %NULL
534 * Synchronously reverse-resolves @address to determine its
535 * associated hostname.
537 * If the DNS resolution fails, @error (if non-%NULL) will be set to
538 * a value from #GResolverError.
540 * If @cancellable is non-%NULL, it can be used to cancel the
541 * operation, in which case @error (if non-%NULL) will be set to
542 * %G_IO_ERROR_CANCELLED.
544 * Returns: a hostname (either ASCII-only, or in ASCII-encoded
545 * form), or %NULL on error.
550 g_resolver_lookup_by_address (GResolver *resolver,
551 GInetAddress *address,
552 GCancellable *cancellable,
555 g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
556 g_return_val_if_fail (G_IS_INET_ADDRESS (address), NULL);
558 g_resolver_maybe_reload (resolver);
559 return G_RESOLVER_GET_CLASS (resolver)->
560 lookup_by_address (resolver, address, cancellable, error);
564 * g_resolver_lookup_by_address_async:
565 * @resolver: a #GResolver
566 * @address: the address to reverse-resolve
567 * @cancellable: (allow-none): a #GCancellable, or %NULL
568 * @callback: (scope async): callback to call after resolution completes
569 * @user_data: (closure): data for @callback
571 * Begins asynchronously reverse-resolving @address to determine its
572 * associated hostname, and eventually calls @callback, which must
573 * call g_resolver_lookup_by_address_finish() to get the final result.
578 g_resolver_lookup_by_address_async (GResolver *resolver,
579 GInetAddress *address,
580 GCancellable *cancellable,
581 GAsyncReadyCallback callback,
584 g_return_if_fail (G_IS_RESOLVER (resolver));
585 g_return_if_fail (G_IS_INET_ADDRESS (address));
587 g_resolver_maybe_reload (resolver);
588 G_RESOLVER_GET_CLASS (resolver)->
589 lookup_by_address_async (resolver, address, cancellable, callback, user_data);
593 * g_resolver_lookup_by_address_finish:
594 * @resolver: a #GResolver
595 * @result: the result passed to your #GAsyncReadyCallback
596 * @error: return location for a #GError, or %NULL
598 * Retrieves the result of a previous call to
599 * g_resolver_lookup_by_address_async().
601 * If the DNS resolution failed, @error (if non-%NULL) will be set to
602 * a value from #GResolverError. If the operation was cancelled,
603 * @error will be set to %G_IO_ERROR_CANCELLED.
605 * Returns: a hostname (either ASCII-only, or in ASCII-encoded
606 * form), or %NULL on error.
611 g_resolver_lookup_by_address_finish (GResolver *resolver,
612 GAsyncResult *result,
615 g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
617 if (g_async_result_legacy_propagate_error (result, error))
620 return G_RESOLVER_GET_CLASS (resolver)->
621 lookup_by_address_finish (resolver, result, error);
625 g_resolver_get_service_rrname (const char *service,
626 const char *protocol,
629 gchar *rrname, *ascii_domain = NULL;
631 if (g_hostname_is_non_ascii (domain))
632 domain = ascii_domain = g_hostname_to_ascii (domain);
634 rrname = g_strdup_printf ("_%s._%s.%s", service, protocol, domain);
636 g_free (ascii_domain);
641 * g_resolver_lookup_service:
642 * @resolver: a #GResolver
643 * @service: the service type to look up (eg, "ldap")
644 * @protocol: the networking protocol to use for @service (eg, "tcp")
645 * @domain: the DNS domain to look up the service in
646 * @cancellable: (allow-none): a #GCancellable, or %NULL
647 * @error: return location for a #GError, or %NULL
649 * Synchronously performs a DNS SRV lookup for the given @service and
650 * @protocol in the given @domain and returns an array of #GSrvTarget.
651 * @domain may be an ASCII-only or UTF-8 hostname. Note also that the
652 * @service and @protocol arguments do not include the leading underscore
653 * that appears in the actual DNS entry.
655 * On success, g_resolver_lookup_service() will return a non-empty #GList of
656 * #GSrvTarget, sorted in order of preference. (That is, you should
657 * attempt to connect to the first target first, then the second if
658 * the first fails, etc.)
660 * If the DNS resolution fails, @error (if non-%NULL) will be set to
661 * a value from #GResolverError and %NULL will be returned.
663 * If @cancellable is non-%NULL, it can be used to cancel the
664 * operation, in which case @error (if non-%NULL) will be set to
665 * %G_IO_ERROR_CANCELLED.
667 * If you are planning to connect to the service, it is usually easier
668 * to create a #GNetworkService and use its #GSocketConnectable
671 * Returns: (element-type GSrvTarget) (transfer full): a non-empty #GList of
672 * #GSrvTarget, or %NULL on error. You must free each of the targets and the
673 * list when you are done with it. (You can use g_resolver_free_targets() to do
679 g_resolver_lookup_service (GResolver *resolver,
680 const gchar *service,
681 const gchar *protocol,
683 GCancellable *cancellable,
689 g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
690 g_return_val_if_fail (service != NULL, NULL);
691 g_return_val_if_fail (protocol != NULL, NULL);
692 g_return_val_if_fail (domain != NULL, NULL);
694 rrname = g_resolver_get_service_rrname (service, protocol, domain);
696 g_resolver_maybe_reload (resolver);
697 targets = G_RESOLVER_GET_CLASS (resolver)->
698 lookup_service (resolver, rrname, cancellable, error);
705 * g_resolver_lookup_service_async:
706 * @resolver: a #GResolver
707 * @service: the service type to look up (eg, "ldap")
708 * @protocol: the networking protocol to use for @service (eg, "tcp")
709 * @domain: the DNS domain to look up the service in
710 * @cancellable: (allow-none): a #GCancellable, or %NULL
711 * @callback: (scope async): callback to call after resolution completes
712 * @user_data: (closure): data for @callback
714 * Begins asynchronously performing a DNS SRV lookup for the given
715 * @service and @protocol in the given @domain, and eventually calls
716 * @callback, which must call g_resolver_lookup_service_finish() to
717 * get the final result. See g_resolver_lookup_service() for more
723 g_resolver_lookup_service_async (GResolver *resolver,
724 const gchar *service,
725 const gchar *protocol,
727 GCancellable *cancellable,
728 GAsyncReadyCallback callback,
733 g_return_if_fail (G_IS_RESOLVER (resolver));
734 g_return_if_fail (service != NULL);
735 g_return_if_fail (protocol != NULL);
736 g_return_if_fail (domain != NULL);
738 rrname = g_resolver_get_service_rrname (service, protocol, domain);
740 g_resolver_maybe_reload (resolver);
741 G_RESOLVER_GET_CLASS (resolver)->
742 lookup_service_async (resolver, rrname, cancellable, callback, user_data);
748 * g_resolver_lookup_service_finish:
749 * @resolver: a #GResolver
750 * @result: the result passed to your #GAsyncReadyCallback
751 * @error: return location for a #GError, or %NULL
753 * Retrieves the result of a previous call to
754 * g_resolver_lookup_service_async().
756 * If the DNS resolution failed, @error (if non-%NULL) will be set to
757 * a value from #GResolverError. If the operation was cancelled,
758 * @error will be set to %G_IO_ERROR_CANCELLED.
760 * Returns: (element-type GSrvTarget) (transfer full): a non-empty #GList of
761 * #GSrvTarget, or %NULL on error. See g_resolver_lookup_service() for more
767 g_resolver_lookup_service_finish (GResolver *resolver,
768 GAsyncResult *result,
771 g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
773 if (g_async_result_legacy_propagate_error (result, error))
776 return G_RESOLVER_GET_CLASS (resolver)->
777 lookup_service_finish (resolver, result, error);
781 * g_resolver_free_targets: (skip)
782 * @targets: a #GList of #GSrvTarget
784 * Frees @targets (which should be the return value from
785 * g_resolver_lookup_service() or g_resolver_lookup_service_finish()).
786 * (This is a convenience method; you can also simply free the
792 g_resolver_free_targets (GList *targets)
796 for (t = targets; t; t = t->next)
797 g_srv_target_free (t->data);
798 g_list_free (targets);
802 * g_resolver_lookup_records:
803 * @resolver: a #GResolver
804 * @rrname: the DNS name to lookup the record for
805 * @record_type: the type of DNS record to lookup
806 * @cancellable: (allow-none): a #GCancellable, or %NULL
807 * @error: return location for a #GError, or %NULL
809 * Synchronously performs a DNS record lookup for the given @rrname and returns
810 * a list of records as #GVariant tuples. See #GResolverRecordType for
811 * information on what the records contain for each @record_type.
813 * If the DNS resolution fails, @error (if non-%NULL) will be set to
814 * a value from #GResolverError and %NULL will be returned.
816 * If @cancellable is non-%NULL, it can be used to cancel the
817 * operation, in which case @error (if non-%NULL) will be set to
818 * %G_IO_ERROR_CANCELLED.
820 * Returns: (element-type GVariant) (transfer full): a non-empty #GList of
821 * #GVariant, or %NULL on error. You must free each of the records and the list
822 * when you are done with it. (You can use g_list_free_full() with
823 * g_variant_unref() to do this.)
828 g_resolver_lookup_records (GResolver *resolver,
830 GResolverRecordType record_type,
831 GCancellable *cancellable,
836 g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
837 g_return_val_if_fail (rrname != NULL, NULL);
839 g_resolver_maybe_reload (resolver);
840 records = G_RESOLVER_GET_CLASS (resolver)->
841 lookup_records (resolver, rrname, record_type, cancellable, error);
847 * g_resolver_lookup_records_async:
848 * @resolver: a #GResolver
849 * @rrname: the DNS name to lookup the record for
850 * @record_type: the type of DNS record to lookup
851 * @cancellable: (allow-none): a #GCancellable, or %NULL
852 * @callback: (scope async): callback to call after resolution completes
853 * @user_data: (closure): data for @callback
855 * Begins asynchronously performing a DNS lookup for the given
856 * @rrname, and eventually calls @callback, which must call
857 * g_resolver_lookup_records_finish() to get the final result. See
858 * g_resolver_lookup_records() for more details.
863 g_resolver_lookup_records_async (GResolver *resolver,
865 GResolverRecordType record_type,
866 GCancellable *cancellable,
867 GAsyncReadyCallback callback,
870 g_return_if_fail (G_IS_RESOLVER (resolver));
871 g_return_if_fail (rrname != NULL);
873 g_resolver_maybe_reload (resolver);
874 G_RESOLVER_GET_CLASS (resolver)->
875 lookup_records_async (resolver, rrname, record_type, cancellable, callback, user_data);
879 * g_resolver_lookup_records_finish:
880 * @resolver: a #GResolver
881 * @result: the result passed to your #GAsyncReadyCallback
882 * @error: return location for a #GError, or %NULL
884 * Retrieves the result of a previous call to
885 * g_resolver_lookup_records_async(). Returns a non-empty list of records as
886 * #GVariant tuples. See #GResolverRecordType for information on what the
889 * If the DNS resolution failed, @error (if non-%NULL) will be set to
890 * a value from #GResolverError. If the operation was cancelled,
891 * @error will be set to %G_IO_ERROR_CANCELLED.
893 * Returns: (element-type GVariant) (transfer full): a non-empty #GList of
894 * #GVariant, or %NULL on error. You must free each of the records and the list
895 * when you are done with it. (You can use g_list_free_full() with
896 * g_variant_unref() to do this.)
901 g_resolver_lookup_records_finish (GResolver *resolver,
902 GAsyncResult *result,
905 g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
906 return G_RESOLVER_GET_CLASS (resolver)->
907 lookup_records_finish (resolver, result, error);
911 g_resolver_get_serial (GResolver *resolver)
913 g_return_val_if_fail (G_IS_RESOLVER (resolver), 0);
915 g_resolver_maybe_reload (resolver);
918 return (guint64) resolver->priv->resolv_conf_timestamp;
925 * g_resolver_error_quark:
927 * Gets the #GResolver Error Quark.
929 * Returns: a #GQuark.
933 G_DEFINE_QUARK (g-resolver-error-quark, g_resolver_error)