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, write to the
19 * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
20 * Boston, MA 02111-1307, USA.
27 #include "gresolver.h"
28 #include "gnetworkingprivate.h"
29 #include "gasyncresult.h"
30 #include "ginetaddress.h"
31 #include "ginetsocketaddress.h"
32 #include "gsimpleasyncresult.h"
33 #include "gsrvtarget.h"
36 #include "gunixresolver.h"
39 #include "gwin32resolver.h"
48 * @short_description: Asynchronous and cancellable DNS resolver
51 * #GResolver provides cancellable synchronous and asynchronous DNS
52 * resolution, for hostnames (g_resolver_lookup_by_address(),
53 * g_resolver_lookup_by_name() and their async variants) and SRV
54 * (service) records (g_resolver_lookup_service()).
56 * #GNetworkAddress and #GNetworkService provide wrappers around
57 * #GResolver functionality that also implement #GSocketConnectable,
58 * making it easy to connect to a remote host/service.
64 * The object that handles DNS resolution. Use g_resolver_get_default()
65 * to get the default resolver.
67 G_DEFINE_TYPE (GResolver, g_resolver, G_TYPE_OBJECT)
70 g_resolver_class_init (GResolverClass *resolver_class)
72 /* Make sure _g_networking_init() has been called */
73 (void) g_inet_address_get_type ();
75 /* Initialize _g_resolver_addrinfo_hints */
77 _g_resolver_addrinfo_hints.ai_flags |= AI_ADDRCONFIG;
79 /* These two don't actually matter, they just get copied into the
80 * returned addrinfo structures (and then we ignore them). But if
81 * we leave them unset, we'll get back duplicate answers.
83 _g_resolver_addrinfo_hints.ai_socktype = SOCK_STREAM;
84 _g_resolver_addrinfo_hints.ai_protocol = IPPROTO_TCP;
88 g_resolver_init (GResolver *resolver)
93 static GResolver *default_resolver;
96 * g_resolver_get_default:
98 * Gets the default #GResolver. You should unref it when you are done
99 * with it. #GResolver may use its reference count as a hint about how
100 * many threads/processes, etc it should allocate for concurrent DNS
103 * Return value: the #GResolver.
108 g_resolver_get_default (void)
110 if (!default_resolver)
112 if (g_thread_supported ())
113 default_resolver = g_object_new (G_TYPE_THREADED_RESOLVER, NULL);
116 #if defined(G_OS_UNIX)
117 default_resolver = g_object_new (G_TYPE_UNIX_RESOLVER, NULL);
118 #elif defined(G_OS_WIN32)
119 default_resolver = g_object_new (G_TYPE_WIN32_RESOLVER, NULL);
124 return g_object_ref (default_resolver);
128 * g_resolver_set_default:
129 * @resolver: the new default #GResolver
131 * Sets @resolver to be the application's default resolver (reffing
132 * @resolver, and unreffing the previous default resolver, if any).
133 * Future calls to g_resolver_get_default() will return this resolver.
135 * This can be used if an application wants to perform any sort of DNS
136 * caching or "pinning"; it can implement its own #GResolver that
137 * calls the original default resolver for DNS operations, and
138 * implements its own cache policies on top of that, and then set
139 * itself as the default resolver for all later code to use.
144 g_resolver_set_default (GResolver *resolver)
146 if (default_resolver)
147 g_object_unref (default_resolver);
148 default_resolver = g_object_ref (resolver);
153 * g_resolver_lookup_by_name:
154 * @resolver: a #GResolver
155 * @hostname: the hostname to look up
156 * @cancellable: a #GCancellable, or %NULL
157 * @error: return location for a #GError, or %NULL
159 * Synchronously resolves @hostname to determine its associated IP
160 * address(es). @hostname may be an ASCII-only or UTF-8 hostname, or
161 * the textual form of an IP address (in which case this just becomes
162 * a wrapper around g_inet_address_new_from_string()).
164 * On success, g_resolver_lookup_by_name() will return a #GList of
165 * #GInetAddress, sorted in order of preference. (That is, you should
166 * attempt to connect to the first address first, then the second if
167 * the first fails, etc.)
169 * If the DNS resolution fails, @error (if non-%NULL) will be set to a
170 * value from #GResolverError.
172 * If @cancellable is non-%NULL, it can be used to cancel the
173 * operation, in which case @error (if non-%NULL) will be set to
174 * %G_IO_ERROR_CANCELLED.
176 * If you are planning to connect to a socket on the resolved IP
177 * address, it may be easier to create a #GNetworkAddress and use its
178 * #GSocketConnectable interface.
180 * Return value: a #GList of #GInetAddress, or %NULL on error. You
181 * must unref each of the addresses and free the list when you are
182 * done with it. (You can use g_resolver_free_addresses() to do this.)
187 g_resolver_lookup_by_name (GResolver *resolver,
188 const gchar *hostname,
189 GCancellable *cancellable,
194 gchar *ascii_hostname = NULL;
196 g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
197 g_return_val_if_fail (hostname != NULL, NULL);
199 /* Check if @hostname is just an IP address */
200 addr = g_inet_address_new_from_string (hostname);
202 return g_list_append (NULL, addr);
204 if (g_hostname_is_non_ascii (hostname))
205 hostname = ascii_hostname = g_hostname_to_ascii (hostname);
207 addrs = G_RESOLVER_GET_CLASS (resolver)->
208 lookup_by_name (resolver, hostname, cancellable, error);
210 g_free (ascii_hostname);
215 * g_resolver_lookup_by_name_async:
216 * @resolver: a #GResolver
217 * @hostname: the hostname to look up the address of
218 * @cancellable: a #GCancellable, or %NULL
219 * @callback: callback to call after resolution completes
220 * @user_data: data for @callback
222 * Begins asynchronously resolving @hostname to determine its
223 * associated IP address(es), and eventually calls @callback, which
224 * must call g_resolver_lookup_by_name_finish() to get the result. See
225 * g_resolver_lookup_by_name() for more details.
230 g_resolver_lookup_by_name_async (GResolver *resolver,
231 const gchar *hostname,
232 GCancellable *cancellable,
233 GAsyncReadyCallback callback,
237 gchar *ascii_hostname = NULL;
239 g_return_if_fail (G_IS_RESOLVER (resolver));
240 g_return_if_fail (hostname != NULL);
242 /* Check if @hostname is just an IP address */
243 addr = g_inet_address_new_from_string (hostname);
246 GSimpleAsyncResult *simple;
249 simple = g_simple_async_result_new (G_OBJECT (resolver),
251 g_resolver_lookup_by_name_async);
253 addrs = g_list_append (NULL, addr);
254 g_simple_async_result_set_op_res_gpointer (simple, addrs, (GDestroyNotify)g_resolver_free_addresses);
255 g_simple_async_result_complete_in_idle (simple);
256 g_object_unref (simple);
260 if (g_hostname_is_non_ascii (hostname))
261 hostname = ascii_hostname = g_hostname_to_ascii (hostname);
263 G_RESOLVER_GET_CLASS (resolver)->
264 lookup_by_name_async (resolver, hostname, cancellable, callback, user_data);
266 g_free (ascii_hostname);
270 * g_resolver_lookup_by_name_finish:
271 * @resolver: a #GResolver
272 * @result: the result passed to your #GAsyncReadyCallback
273 * @error: return location for a #GError, or %NULL
275 * Retrieves the result of a call to
276 * g_resolver_lookup_by_name_async().
278 * If the DNS resolution failed, @error (if non-%NULL) will be set to
279 * a value from #GResolverError. If the operation was cancelled,
280 * @error will be set to %G_IO_ERROR_CANCELLED.
282 * Return value: a #GList of #GInetAddress, or %NULL on error. See
283 * g_resolver_lookup_by_name() for more details.
288 g_resolver_lookup_by_name_finish (GResolver *resolver,
289 GAsyncResult *result,
292 g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
294 if (G_IS_SIMPLE_ASYNC_RESULT (result))
296 GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
298 if (g_simple_async_result_propagate_error (simple, error))
301 /* Handle the stringified-IP-addr case */
302 if (g_simple_async_result_get_source_tag (simple) == g_resolver_lookup_by_name_async)
306 addrs = g_simple_async_result_get_op_res_gpointer (simple);
307 g_simple_async_result_set_op_res_gpointer (simple, NULL, NULL);
312 return G_RESOLVER_GET_CLASS (resolver)->
313 lookup_by_name_finish (resolver, result, error);
317 * g_resolver_free_addresses:
318 * @addresses: a #GList of #GInetAddress
320 * Frees @addresses (which should be the return value from
321 * g_resolver_lookup_by_name() or g_resolver_lookup_by_name_finish()).
322 * (This is a convenience method; you can also simply free the results
328 g_resolver_free_addresses (GList *addresses)
332 for (a = addresses; a; a = a->next)
333 g_object_unref (a->data);
334 g_list_free (addresses);
338 * g_resolver_lookup_by_address:
339 * @resolver: a #GResolver
340 * @address: the address to reverse-resolve
341 * @cancellable: a #GCancellable, or %NULL
342 * @error: return location for a #GError, or %NULL
344 * Synchronously reverse-resolves @address to determine its
345 * associated hostname.
347 * If the DNS resolution fails, @error (if non-%NULL) will be set to
348 * a value from #GResolverError.
350 * If @cancellable is non-%NULL, it can be used to cancel the
351 * operation, in which case @error (if non-%NULL) will be set to
352 * %G_IO_ERROR_CANCELLED.
354 * Return value: a hostname (either ASCII-only, or in ASCII-encoded
355 * form), or %NULL on error.
360 g_resolver_lookup_by_address (GResolver *resolver,
361 GInetAddress *address,
362 GCancellable *cancellable,
365 g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
366 g_return_val_if_fail (G_IS_INET_ADDRESS (address), NULL);
368 return G_RESOLVER_GET_CLASS (resolver)->
369 lookup_by_address (resolver, address, cancellable, error);
373 * g_resolver_lookup_by_address_async:
374 * @resolver: a #GResolver
375 * @address: the address to reverse-resolve
376 * @cancellable: a #GCancellable, or %NULL
377 * @callback: callback to call after resolution completes
378 * @user_data: data for @callback
380 * Begins asynchronously reverse-resolving @address to determine its
381 * associated hostname, and eventually calls @callback, which must
382 * call g_resolver_lookup_by_address_finish() to get the final result.
387 g_resolver_lookup_by_address_async (GResolver *resolver,
388 GInetAddress *address,
389 GCancellable *cancellable,
390 GAsyncReadyCallback callback,
393 g_return_if_fail (G_IS_RESOLVER (resolver));
394 g_return_if_fail (G_IS_INET_ADDRESS (address));
396 G_RESOLVER_GET_CLASS (resolver)->
397 lookup_by_address_async (resolver, address, cancellable, callback, user_data);
401 * g_resolver_lookup_by_address_finish:
402 * @resolver: a #GResolver
403 * @result: the result passed to your #GAsyncReadyCallback
404 * @error: return location for a #GError, or %NULL
406 * Retrieves the result of a previous call to
407 * g_resolver_lookup_by_address_async().
409 * If the DNS resolution failed, @error (if non-%NULL) will be set to
410 * a value from #GResolverError. If the operation was cancelled,
411 * @error will be set to %G_IO_ERROR_CANCELLED.
413 * Return value: a hostname (either ASCII-only, or in ASCII-encoded
414 * form), or %NULL on error.
419 g_resolver_lookup_by_address_finish (GResolver *resolver,
420 GAsyncResult *result,
423 g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
425 if (G_IS_SIMPLE_ASYNC_RESULT (result))
427 GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
429 if (g_simple_async_result_propagate_error (simple, error))
433 return G_RESOLVER_GET_CLASS (resolver)->
434 lookup_by_address_finish (resolver, result, error);
438 g_resolver_get_service_rrname (const char *service,
439 const char *protocol,
442 gchar *rrname, *ascii_domain = NULL;
444 if (g_hostname_is_non_ascii (domain))
445 domain = ascii_domain = g_hostname_to_ascii (domain);
447 rrname = g_strdup_printf ("_%s._%s.%s", service, protocol, domain);
449 g_free (ascii_domain);
454 * g_resolver_lookup_service:
455 * @resolver: a #GResolver
456 * @service: the service type to look up (eg, "ldap")
457 * @protocol: the networking protocol to use for @service (eg, "tcp")
458 * @domain: the DNS domain to look up the service in
459 * @cancellable: a #GCancellable, or %NULL
460 * @error: return location for a #GError, or %NULL
462 * Synchronously performs a DNS SRV lookup for the given @service and
463 * @protocol in the given @domain and returns an array of #GSrvTarget.
464 * @domain may be an ASCII-only or UTF-8 hostname. Note also that the
465 * @service and @protocol arguments <emphasis>do not</emphasis>
466 * include the leading underscore that appears in the actual DNS
469 * On success, g_resolver_lookup_service() will return a #GList of
470 * #GSrvTarget, sorted in order of preference. (That is, you should
471 * attempt to connect to the first target first, then the second if
472 * the first fails, etc.)
474 * If the DNS resolution fails, @error (if non-%NULL) will be set to
475 * a value from #GResolverError.
477 * If @cancellable is non-%NULL, it can be used to cancel the
478 * operation, in which case @error (if non-%NULL) will be set to
479 * %G_IO_ERROR_CANCELLED.
481 * If you are planning to connect to the service, it is usually easier
482 * to create a #GNetworkService and use its #GSocketConnectable
485 * Return value: a #GList of #GSrvTarget, or %NULL on error. You must
486 * free each of the targets and the list when you are done with it.
487 * (You can use g_resolver_free_targets() to do this.)
492 g_resolver_lookup_service (GResolver *resolver,
493 const gchar *service,
494 const gchar *protocol,
496 GCancellable *cancellable,
502 g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
503 g_return_val_if_fail (service != NULL, NULL);
504 g_return_val_if_fail (protocol != NULL, NULL);
505 g_return_val_if_fail (domain != NULL, NULL);
507 rrname = g_resolver_get_service_rrname (service, protocol, domain);
509 targets = G_RESOLVER_GET_CLASS (resolver)->
510 lookup_service (resolver, rrname, cancellable, error);
517 * g_resolver_lookup_service_async:
518 * @resolver: a #GResolver
519 * @service: the service type to look up (eg, "ldap")
520 * @protocol: the networking protocol to use for @service (eg, "tcp")
521 * @domain: the DNS domain to look up the service in
522 * @cancellable: a #GCancellable, or %NULL
523 * @callback: callback to call after resolution completes
524 * @user_data: data for @callback
526 * Begins asynchronously performing a DNS SRV lookup for the given
527 * @service and @protocol in the given @domain, and eventually calls
528 * @callback, which must call g_resolver_lookup_service_finish() to
529 * get the final result. See g_resolver_lookup_service() for more
535 g_resolver_lookup_service_async (GResolver *resolver,
536 const gchar *service,
537 const gchar *protocol,
539 GCancellable *cancellable,
540 GAsyncReadyCallback callback,
545 g_return_if_fail (G_IS_RESOLVER (resolver));
546 g_return_if_fail (service != NULL);
547 g_return_if_fail (protocol != NULL);
548 g_return_if_fail (domain != NULL);
550 rrname = g_resolver_get_service_rrname (service, protocol, domain);
552 G_RESOLVER_GET_CLASS (resolver)->
553 lookup_service_async (resolver, rrname, cancellable, callback, user_data);
559 * g_resolver_lookup_service_finish:
560 * @resolver: a #GResolver
561 * @result: the result passed to your #GAsyncReadyCallback
562 * @error: return location for a #GError, or %NULL
564 * Retrieves the result of a previous call to
565 * g_resolver_lookup_service_async().
567 * If the DNS resolution failed, @error (if non-%NULL) will be set to
568 * a value from #GResolverError. If the operation was cancelled,
569 * @error will be set to %G_IO_ERROR_CANCELLED.
571 * Return value: a #GList of #GSrvTarget, or %NULL on error. See
572 * g_resolver_lookup_service() for more details.
577 g_resolver_lookup_service_finish (GResolver *resolver,
578 GAsyncResult *result,
581 g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
583 if (G_IS_SIMPLE_ASYNC_RESULT (result))
585 GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (result);
587 if (g_simple_async_result_propagate_error (simple, error))
591 return G_RESOLVER_GET_CLASS (resolver)->
592 lookup_service_finish (resolver, result, error);
596 * g_resolver_free_targets:
597 * @targets: a #GList of #GSrvTarget
599 * Frees @targets (which should be the return value from
600 * g_resolver_lookup_service() or g_resolver_lookup_service_finish()).
601 * (This is a convenience method; you can also simply free the
607 g_resolver_free_targets (GList *targets)
611 for (t = targets; t; t = t->next)
612 g_srv_target_free (t->data);
613 g_list_free (targets);
617 * g_resolver_error_quark:
619 * Gets the #GResolver Error Quark.
621 * Return value: a #GQuark.
626 g_resolver_error_quark (void)
628 return g_quark_from_static_string ("g-resolver-error-quark");
632 static GResolverError
633 g_resolver_error_from_addrinfo_error (gint err)
640 return G_RESOLVER_ERROR_NOT_FOUND;
643 return G_RESOLVER_ERROR_TEMPORARY_FAILURE;
646 return G_RESOLVER_ERROR_INTERNAL;
650 struct addrinfo _g_resolver_addrinfo_hints;
652 /* Private method to process a getaddrinfo() response. */
654 _g_resolver_addresses_from_addrinfo (const char *hostname,
655 struct addrinfo *res,
660 GSocketAddress *sockaddr;
666 g_set_error (error, G_RESOLVER_ERROR,
667 g_resolver_error_from_addrinfo_error (gai_retval),
668 _("Error resolving '%s': %s"),
669 hostname, gai_strerror (gai_retval));
673 g_return_val_if_fail (res != NULL, NULL);
676 for (ai = res; ai; ai = ai->ai_next)
678 sockaddr = g_socket_address_new_from_native (ai->ai_addr, ai->ai_addrlen);
679 if (!sockaddr || !G_IS_INET_SOCKET_ADDRESS (sockaddr))
682 addr = g_object_ref (g_inet_socket_address_get_address ((GInetSocketAddress *)sockaddr));
683 addrs = g_list_prepend (addrs, addr);
684 g_object_unref (sockaddr);
687 return g_list_reverse (addrs);
690 /* Private method to set up a getnameinfo() request */
692 _g_resolver_address_to_sockaddr (GInetAddress *address,
693 struct sockaddr_storage *sa,
696 GSocketAddress *sockaddr;
698 sockaddr = g_inet_socket_address_new (address, 0);
699 g_socket_address_to_native (sockaddr, (struct sockaddr *)sa, sizeof (*sa));
700 *sa_len = g_socket_address_get_native_size (sockaddr);
701 g_object_unref (sockaddr);
704 /* Private method to process a getnameinfo() response. */
706 _g_resolver_name_from_nameinfo (GInetAddress *address,
715 phys = g_inet_address_to_string (address);
716 g_set_error (error, G_RESOLVER_ERROR,
717 g_resolver_error_from_addrinfo_error (gni_retval),
718 _("Error reverse-resolving '%s': %s"),
719 phys ? phys : "(unknown)", gai_strerror (gni_retval));
724 return g_strdup (name);
727 #if defined(G_OS_UNIX)
728 /* Private method to process a res_query response into GSrvTargets */
730 _g_resolver_targets_from_res_query (const gchar *rrname,
739 guint16 type, qclass, rdlength, priority, weight, port;
747 GResolverError errnum;
750 if (len == 0 || herr == HOST_NOT_FOUND || herr == NO_DATA)
752 errnum = G_RESOLVER_ERROR_NOT_FOUND;
753 format = _("No service record for '%s'");
755 else if (herr == TRY_AGAIN)
757 errnum = G_RESOLVER_ERROR_TEMPORARY_FAILURE;
758 format = _("Temporarily unable to resolve '%s'");
762 errnum = G_RESOLVER_ERROR_INTERNAL;
763 format = _("Error resolving '%s'");
766 g_set_error (error, G_RESOLVER_ERROR, errnum, format, rrname);
772 header = (HEADER *)answer;
773 p = answer + sizeof (HEADER);
777 count = ntohs (header->qdcount);
778 while (count-- && p < end)
780 p += dn_expand (answer, end, p, namebuf, sizeof (namebuf));
785 count = ntohs (header->ancount);
786 while (count-- && p < end)
788 p += dn_expand (answer, end, p, namebuf, sizeof (namebuf));
790 GETSHORT (qclass, p);
792 GETSHORT (rdlength, p);
794 if (type != T_SRV || qclass != C_IN)
800 GETSHORT (priority, p);
801 GETSHORT (weight, p);
803 p += dn_expand (answer, end, p, namebuf, sizeof (namebuf));
805 target = g_srv_target_new (namebuf, port, priority, weight);
806 targets = g_list_prepend (targets, target);
809 return g_srv_target_list_sort (targets);
811 #elif defined(G_OS_WIN32)
812 /* Private method to process a DnsQuery response into GSrvTargets */
814 _g_resolver_targets_from_DnsQuery (const gchar *rrname,
823 if (status != ERROR_SUCCESS)
825 GResolverError errnum;
828 if (status == DNS_ERROR_RCODE_NAME_ERROR)
830 errnum = G_RESOLVER_ERROR_NOT_FOUND;
831 format = _("No service record for '%s'");
833 else if (status == DNS_ERROR_RCODE_SERVER_FAILURE)
835 errnum = G_RESOLVER_ERROR_TEMPORARY_FAILURE;
836 format = _("Temporarily unable to resolve '%s'");
840 errnum = G_RESOLVER_ERROR_INTERNAL;
841 format = _("Error resolving '%s'");
844 g_set_error (error, G_RESOLVER_ERROR, errnum, format, rrname);
849 for (rec = results; rec; rec = rec->pNext)
851 if (rec->wType != DNS_TYPE_SRV)
854 target = g_srv_target_new (rec->Data.SRV.pNameTarget,
856 rec->Data.SRV.wPriority,
857 rec->Data.SRV.wWeight);
858 targets = g_list_prepend (targets, target);
861 return g_srv_target_list_sort (targets);
866 #define __G_RESOLVER_C__
867 #include "gioaliasdef.c"