glib/gio/gresolver.c
Philip Withnall 10bac98185 gresolver: Mark GResolver as an abstract class
It only works through its virtual methods, so while it could be
instantiated before (and this is technically an API break), any instance
of it would previously have crashed as soon as any of its methods were
called anyway.

If anybody has any problems with this ABI break, please make them known
during the 2.51 unstable development cycle and it can be reverted.

https://bugzilla.gnome.org/show_bug.cgi?id=772255
2016-10-04 16:02:34 +01:00

934 lines
29 KiB
C

/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* GIO - GLib Input, Output and Streaming Library
*
* Copyright (C) 2008 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <glib.h>
#include "glibintl.h"
#include "gresolver.h"
#include "gnetworkingprivate.h"
#include "gasyncresult.h"
#include "ginetaddress.h"
#include "gtask.h"
#include "gsrvtarget.h"
#include "gthreadedresolver.h"
#ifdef G_OS_UNIX
#include <sys/stat.h>
#endif
#include <stdlib.h>
/**
* SECTION:gresolver
* @short_description: Asynchronous and cancellable DNS resolver
* @include: gio/gio.h
*
* #GResolver provides cancellable synchronous and asynchronous DNS
* resolution, for hostnames (g_resolver_lookup_by_address(),
* g_resolver_lookup_by_name() and their async variants) and SRV
* (service) records (g_resolver_lookup_service()).
*
* #GNetworkAddress and #GNetworkService provide wrappers around
* #GResolver functionality that also implement #GSocketConnectable,
* making it easy to connect to a remote host/service.
*/
enum {
RELOAD,
LAST_SIGNAL
};
static guint signals[LAST_SIGNAL] = { 0 };
struct _GResolverPrivate {
#ifdef G_OS_UNIX
time_t resolv_conf_timestamp;
#else
int dummy;
#endif
};
/**
* GResolver:
*
* The object that handles DNS resolution. Use g_resolver_get_default()
* to get the default resolver.
*
* This is an abstract type; subclasses of it implement different resolvers for
* different platforms and situations.
*/
G_DEFINE_ABSTRACT_TYPE_WITH_CODE (GResolver, g_resolver, G_TYPE_OBJECT,
G_ADD_PRIVATE (GResolver)
g_networking_init ();)
static GList *
srv_records_to_targets (GList *records)
{
const gchar *hostname;
guint16 port, priority, weight;
GSrvTarget *target;
GList *l;
for (l = records; l != NULL; l = g_list_next (l))
{
g_variant_get (l->data, "(qqq&s)", &priority, &weight, &port, &hostname);
target = g_srv_target_new (hostname, port, priority, weight);
g_variant_unref (l->data);
l->data = target;
}
return g_srv_target_list_sort (records);
}
static GList *
g_resolver_real_lookup_service (GResolver *resolver,
const gchar *rrname,
GCancellable *cancellable,
GError **error)
{
GList *records;
records = G_RESOLVER_GET_CLASS (resolver)->lookup_records (resolver,
rrname,
G_RESOLVER_RECORD_SRV,
cancellable,
error);
return srv_records_to_targets (records);
}
static void
g_resolver_real_lookup_service_async (GResolver *resolver,
const gchar *rrname,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
G_RESOLVER_GET_CLASS (resolver)->lookup_records_async (resolver,
rrname,
G_RESOLVER_RECORD_SRV,
cancellable,
callback,
user_data);
}
static GList *
g_resolver_real_lookup_service_finish (GResolver *resolver,
GAsyncResult *result,
GError **error)
{
GList *records;
records = G_RESOLVER_GET_CLASS (resolver)->lookup_records_finish (resolver,
result,
error);
return srv_records_to_targets (records);
}
static void
g_resolver_class_init (GResolverClass *resolver_class)
{
/* Automatically pass these over to the lookup_records methods */
resolver_class->lookup_service = g_resolver_real_lookup_service;
resolver_class->lookup_service_async = g_resolver_real_lookup_service_async;
resolver_class->lookup_service_finish = g_resolver_real_lookup_service_finish;
/**
* GResolver::reload:
* @resolver: a #GResolver
*
* Emitted when the resolver notices that the system resolver
* configuration has changed.
**/
signals[RELOAD] =
g_signal_new (I_("reload"),
G_TYPE_RESOLVER,
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GResolverClass, reload),
NULL, NULL,
g_cclosure_marshal_VOID__VOID,
G_TYPE_NONE, 0);
}
static void
g_resolver_init (GResolver *resolver)
{
#ifdef G_OS_UNIX
struct stat st;
#endif
resolver->priv = g_resolver_get_instance_private (resolver);
#ifdef G_OS_UNIX
if (stat (_PATH_RESCONF, &st) == 0)
resolver->priv->resolv_conf_timestamp = st.st_mtime;
#endif
}
static GResolver *default_resolver;
/**
* g_resolver_get_default:
*
* Gets the default #GResolver. You should unref it when you are done
* with it. #GResolver may use its reference count as a hint about how
* many threads it should allocate for concurrent DNS resolutions.
*
* Returns: (transfer full): the default #GResolver.
*
* Since: 2.22
*/
GResolver *
g_resolver_get_default (void)
{
if (!default_resolver)
default_resolver = g_object_new (G_TYPE_THREADED_RESOLVER, NULL);
return g_object_ref (default_resolver);
}
/**
* g_resolver_set_default:
* @resolver: the new default #GResolver
*
* Sets @resolver to be the application's default resolver (reffing
* @resolver, and unreffing the previous default resolver, if any).
* Future calls to g_resolver_get_default() will return this resolver.
*
* This can be used if an application wants to perform any sort of DNS
* caching or "pinning"; it can implement its own #GResolver that
* calls the original default resolver for DNS operations, and
* implements its own cache policies on top of that, and then set
* itself as the default resolver for all later code to use.
*
* Since: 2.22
*/
void
g_resolver_set_default (GResolver *resolver)
{
if (default_resolver)
g_object_unref (default_resolver);
default_resolver = g_object_ref (resolver);
}
/* Bionic has res_init() but it's not in any header */
#ifdef __BIONIC__
int res_init (void);
#endif
static void
g_resolver_maybe_reload (GResolver *resolver)
{
#ifdef G_OS_UNIX
struct stat st;
if (stat (_PATH_RESCONF, &st) == 0)
{
if (st.st_mtime != resolver->priv->resolv_conf_timestamp)
{
resolver->priv->resolv_conf_timestamp = st.st_mtime;
#ifdef HAVE_RES_INIT
res_init ();
#endif
g_signal_emit (resolver, signals[RELOAD], 0);
}
}
#endif
}
/* filter out duplicates, cf. https://bugzilla.gnome.org/show_bug.cgi?id=631379 */
static void
remove_duplicates (GList *addrs)
{
GList *l;
GList *ll;
GList *lll;
/* TODO: if this is too slow (it's O(n^2) but n is typically really
* small), we can do something more clever but note that we must not
* change the order of elements...
*/
for (l = addrs; l != NULL; l = l->next)
{
GInetAddress *address = G_INET_ADDRESS (l->data);
for (ll = l->next; ll != NULL; ll = lll)
{
GInetAddress *other_address = G_INET_ADDRESS (ll->data);
lll = ll->next;
if (g_inet_address_equal (address, other_address))
{
g_object_unref (other_address);
/* we never return the first element */
g_warn_if_fail (g_list_delete_link (addrs, ll) == addrs);
}
}
}
}
/* Note that this does not follow the "FALSE means @error is set"
* convention. The return value tells the caller whether it should
* return @addrs and @error to the caller right away, or if it should
* continue and trying to resolve the name as a hostname.
*/
static gboolean
handle_ip_address (const char *hostname,
GList **addrs,
GError **error)
{
GInetAddress *addr;
#ifndef G_OS_WIN32
struct in_addr ip4addr;
#endif
addr = g_inet_address_new_from_string (hostname);
if (addr)
{
*addrs = g_list_append (NULL, addr);
return TRUE;
}
*addrs = NULL;
#ifdef G_OS_WIN32
/* Reject IPv6 addresses that have brackets ('[' or ']') and/or port numbers,
* as no valid addresses should contain these at this point.
* Non-standard IPv4 addresses would be rejected during the call to
* getaddrinfo() later.
*/
if (strrchr (hostname, '[') != NULL ||
strrchr (hostname, ']') != NULL)
#else
/* Reject non-standard IPv4 numbers-and-dots addresses.
* g_inet_address_new_from_string() will have accepted any "real" IP
* address, so if inet_aton() succeeds, then it's an address we want
* to reject.
*/
if (inet_aton (hostname, &ip4addr))
#endif
{
g_set_error (error, G_RESOLVER_ERROR, G_RESOLVER_ERROR_NOT_FOUND,
_("Error resolving '%s': %s"),
hostname, gai_strerror (EAI_NONAME));
return TRUE;
}
return FALSE;
}
/**
* g_resolver_lookup_by_name:
* @resolver: a #GResolver
* @hostname: the hostname to look up
* @cancellable: (allow-none): a #GCancellable, or %NULL
* @error: return location for a #GError, or %NULL
*
* Synchronously resolves @hostname to determine its associated IP
* address(es). @hostname may be an ASCII-only or UTF-8 hostname, or
* the textual form of an IP address (in which case this just becomes
* a wrapper around g_inet_address_new_from_string()).
*
* On success, g_resolver_lookup_by_name() will return a non-empty #GList of
* #GInetAddress, sorted in order of preference and guaranteed to not
* contain duplicates. That is, if using the result to connect to
* @hostname, you should attempt to connect to the first address
* first, then the second if the first fails, etc. If you are using
* the result to listen on a socket, it is appropriate to add each
* result using e.g. g_socket_listener_add_address().
*
* If the DNS resolution fails, @error (if non-%NULL) will be set to a
* value from #GResolverError and %NULL will be returned.
*
* If @cancellable is non-%NULL, it can be used to cancel the
* operation, in which case @error (if non-%NULL) will be set to
* %G_IO_ERROR_CANCELLED.
*
* If you are planning to connect to a socket on the resolved IP
* address, it may be easier to create a #GNetworkAddress and use its
* #GSocketConnectable interface.
*
* Returns: (element-type GInetAddress) (transfer full): a non-empty #GList
* of #GInetAddress, or %NULL on error. You
* must unref each of the addresses and free the list when you are
* done with it. (You can use g_resolver_free_addresses() to do this.)
*
* Since: 2.22
*/
GList *
g_resolver_lookup_by_name (GResolver *resolver,
const gchar *hostname,
GCancellable *cancellable,
GError **error)
{
GList *addrs;
gchar *ascii_hostname = NULL;
g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
g_return_val_if_fail (hostname != NULL, NULL);
/* Check if @hostname is just an IP address */
if (handle_ip_address (hostname, &addrs, error))
return addrs;
if (g_hostname_is_non_ascii (hostname))
hostname = ascii_hostname = g_hostname_to_ascii (hostname);
g_resolver_maybe_reload (resolver);
addrs = G_RESOLVER_GET_CLASS (resolver)->
lookup_by_name (resolver, hostname, cancellable, error);
remove_duplicates (addrs);
g_free (ascii_hostname);
return addrs;
}
/**
* g_resolver_lookup_by_name_async:
* @resolver: a #GResolver
* @hostname: the hostname to look up the address of
* @cancellable: (allow-none): a #GCancellable, or %NULL
* @callback: (scope async): callback to call after resolution completes
* @user_data: (closure): data for @callback
*
* Begins asynchronously resolving @hostname to determine its
* associated IP address(es), and eventually calls @callback, which
* must call g_resolver_lookup_by_name_finish() to get the result.
* See g_resolver_lookup_by_name() for more details.
*
* Since: 2.22
*/
void
g_resolver_lookup_by_name_async (GResolver *resolver,
const gchar *hostname,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
gchar *ascii_hostname = NULL;
GList *addrs;
GError *error = NULL;
g_return_if_fail (G_IS_RESOLVER (resolver));
g_return_if_fail (hostname != NULL);
/* Check if @hostname is just an IP address */
if (handle_ip_address (hostname, &addrs, &error))
{
GTask *task;
task = g_task_new (resolver, cancellable, callback, user_data);
g_task_set_source_tag (task, g_resolver_lookup_by_name_async);
if (addrs)
g_task_return_pointer (task, addrs, (GDestroyNotify) g_resolver_free_addresses);
else
g_task_return_error (task, error);
g_object_unref (task);
return;
}
if (g_hostname_is_non_ascii (hostname))
hostname = ascii_hostname = g_hostname_to_ascii (hostname);
g_resolver_maybe_reload (resolver);
G_RESOLVER_GET_CLASS (resolver)->
lookup_by_name_async (resolver, hostname, cancellable, callback, user_data);
g_free (ascii_hostname);
}
/**
* g_resolver_lookup_by_name_finish:
* @resolver: a #GResolver
* @result: the result passed to your #GAsyncReadyCallback
* @error: return location for a #GError, or %NULL
*
* Retrieves the result of a call to
* g_resolver_lookup_by_name_async().
*
* If the DNS resolution failed, @error (if non-%NULL) will be set to
* a value from #GResolverError. If the operation was cancelled,
* @error will be set to %G_IO_ERROR_CANCELLED.
*
* Returns: (element-type GInetAddress) (transfer full): a #GList
* of #GInetAddress, or %NULL on error. See g_resolver_lookup_by_name()
* for more details.
*
* Since: 2.22
*/
GList *
g_resolver_lookup_by_name_finish (GResolver *resolver,
GAsyncResult *result,
GError **error)
{
GList *addrs;
g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
if (g_async_result_legacy_propagate_error (result, error))
return NULL;
else if (g_async_result_is_tagged (result, g_resolver_lookup_by_name_async))
{
/* Handle the stringified-IP-addr case */
return g_task_propagate_pointer (G_TASK (result), error);
}
addrs = G_RESOLVER_GET_CLASS (resolver)->
lookup_by_name_finish (resolver, result, error);
remove_duplicates (addrs);
return addrs;
}
/**
* g_resolver_free_addresses: (skip)
* @addresses: a #GList of #GInetAddress
*
* Frees @addresses (which should be the return value from
* g_resolver_lookup_by_name() or g_resolver_lookup_by_name_finish()).
* (This is a convenience method; you can also simply free the results
* by hand.)
*
* Since: 2.22
*/
void
g_resolver_free_addresses (GList *addresses)
{
GList *a;
for (a = addresses; a; a = a->next)
g_object_unref (a->data);
g_list_free (addresses);
}
/**
* g_resolver_lookup_by_address:
* @resolver: a #GResolver
* @address: the address to reverse-resolve
* @cancellable: (allow-none): a #GCancellable, or %NULL
* @error: return location for a #GError, or %NULL
*
* Synchronously reverse-resolves @address to determine its
* associated hostname.
*
* If the DNS resolution fails, @error (if non-%NULL) will be set to
* a value from #GResolverError.
*
* If @cancellable is non-%NULL, it can be used to cancel the
* operation, in which case @error (if non-%NULL) will be set to
* %G_IO_ERROR_CANCELLED.
*
* Returns: a hostname (either ASCII-only, or in ASCII-encoded
* form), or %NULL on error.
*
* Since: 2.22
*/
gchar *
g_resolver_lookup_by_address (GResolver *resolver,
GInetAddress *address,
GCancellable *cancellable,
GError **error)
{
g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
g_return_val_if_fail (G_IS_INET_ADDRESS (address), NULL);
g_resolver_maybe_reload (resolver);
return G_RESOLVER_GET_CLASS (resolver)->
lookup_by_address (resolver, address, cancellable, error);
}
/**
* g_resolver_lookup_by_address_async:
* @resolver: a #GResolver
* @address: the address to reverse-resolve
* @cancellable: (allow-none): a #GCancellable, or %NULL
* @callback: (scope async): callback to call after resolution completes
* @user_data: (closure): data for @callback
*
* Begins asynchronously reverse-resolving @address to determine its
* associated hostname, and eventually calls @callback, which must
* call g_resolver_lookup_by_address_finish() to get the final result.
*
* Since: 2.22
*/
void
g_resolver_lookup_by_address_async (GResolver *resolver,
GInetAddress *address,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
g_return_if_fail (G_IS_RESOLVER (resolver));
g_return_if_fail (G_IS_INET_ADDRESS (address));
g_resolver_maybe_reload (resolver);
G_RESOLVER_GET_CLASS (resolver)->
lookup_by_address_async (resolver, address, cancellable, callback, user_data);
}
/**
* g_resolver_lookup_by_address_finish:
* @resolver: a #GResolver
* @result: the result passed to your #GAsyncReadyCallback
* @error: return location for a #GError, or %NULL
*
* Retrieves the result of a previous call to
* g_resolver_lookup_by_address_async().
*
* If the DNS resolution failed, @error (if non-%NULL) will be set to
* a value from #GResolverError. If the operation was cancelled,
* @error will be set to %G_IO_ERROR_CANCELLED.
*
* Returns: a hostname (either ASCII-only, or in ASCII-encoded
* form), or %NULL on error.
*
* Since: 2.22
*/
gchar *
g_resolver_lookup_by_address_finish (GResolver *resolver,
GAsyncResult *result,
GError **error)
{
g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
if (g_async_result_legacy_propagate_error (result, error))
return NULL;
return G_RESOLVER_GET_CLASS (resolver)->
lookup_by_address_finish (resolver, result, error);
}
static gchar *
g_resolver_get_service_rrname (const char *service,
const char *protocol,
const char *domain)
{
gchar *rrname, *ascii_domain = NULL;
if (g_hostname_is_non_ascii (domain))
domain = ascii_domain = g_hostname_to_ascii (domain);
rrname = g_strdup_printf ("_%s._%s.%s", service, protocol, domain);
g_free (ascii_domain);
return rrname;
}
/**
* g_resolver_lookup_service:
* @resolver: a #GResolver
* @service: the service type to look up (eg, "ldap")
* @protocol: the networking protocol to use for @service (eg, "tcp")
* @domain: the DNS domain to look up the service in
* @cancellable: (allow-none): a #GCancellable, or %NULL
* @error: return location for a #GError, or %NULL
*
* Synchronously performs a DNS SRV lookup for the given @service and
* @protocol in the given @domain and returns an array of #GSrvTarget.
* @domain may be an ASCII-only or UTF-8 hostname. Note also that the
* @service and @protocol arguments do not include the leading underscore
* that appears in the actual DNS entry.
*
* On success, g_resolver_lookup_service() will return a non-empty #GList of
* #GSrvTarget, sorted in order of preference. (That is, you should
* attempt to connect to the first target first, then the second if
* the first fails, etc.)
*
* If the DNS resolution fails, @error (if non-%NULL) will be set to
* a value from #GResolverError and %NULL will be returned.
*
* If @cancellable is non-%NULL, it can be used to cancel the
* operation, in which case @error (if non-%NULL) will be set to
* %G_IO_ERROR_CANCELLED.
*
* If you are planning to connect to the service, it is usually easier
* to create a #GNetworkService and use its #GSocketConnectable
* interface.
*
* Returns: (element-type GSrvTarget) (transfer full): a non-empty #GList of
* #GSrvTarget, or %NULL on error. You must free each of the targets and the
* list when you are done with it. (You can use g_resolver_free_targets() to do
* this.)
*
* Since: 2.22
*/
GList *
g_resolver_lookup_service (GResolver *resolver,
const gchar *service,
const gchar *protocol,
const gchar *domain,
GCancellable *cancellable,
GError **error)
{
GList *targets;
gchar *rrname;
g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
g_return_val_if_fail (service != NULL, NULL);
g_return_val_if_fail (protocol != NULL, NULL);
g_return_val_if_fail (domain != NULL, NULL);
rrname = g_resolver_get_service_rrname (service, protocol, domain);
g_resolver_maybe_reload (resolver);
targets = G_RESOLVER_GET_CLASS (resolver)->
lookup_service (resolver, rrname, cancellable, error);
g_free (rrname);
return targets;
}
/**
* g_resolver_lookup_service_async:
* @resolver: a #GResolver
* @service: the service type to look up (eg, "ldap")
* @protocol: the networking protocol to use for @service (eg, "tcp")
* @domain: the DNS domain to look up the service in
* @cancellable: (allow-none): a #GCancellable, or %NULL
* @callback: (scope async): callback to call after resolution completes
* @user_data: (closure): data for @callback
*
* Begins asynchronously performing a DNS SRV lookup for the given
* @service and @protocol in the given @domain, and eventually calls
* @callback, which must call g_resolver_lookup_service_finish() to
* get the final result. See g_resolver_lookup_service() for more
* details.
*
* Since: 2.22
*/
void
g_resolver_lookup_service_async (GResolver *resolver,
const gchar *service,
const gchar *protocol,
const gchar *domain,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
gchar *rrname;
g_return_if_fail (G_IS_RESOLVER (resolver));
g_return_if_fail (service != NULL);
g_return_if_fail (protocol != NULL);
g_return_if_fail (domain != NULL);
rrname = g_resolver_get_service_rrname (service, protocol, domain);
g_resolver_maybe_reload (resolver);
G_RESOLVER_GET_CLASS (resolver)->
lookup_service_async (resolver, rrname, cancellable, callback, user_data);
g_free (rrname);
}
/**
* g_resolver_lookup_service_finish:
* @resolver: a #GResolver
* @result: the result passed to your #GAsyncReadyCallback
* @error: return location for a #GError, or %NULL
*
* Retrieves the result of a previous call to
* g_resolver_lookup_service_async().
*
* If the DNS resolution failed, @error (if non-%NULL) will be set to
* a value from #GResolverError. If the operation was cancelled,
* @error will be set to %G_IO_ERROR_CANCELLED.
*
* Returns: (element-type GSrvTarget) (transfer full): a non-empty #GList of
* #GSrvTarget, or %NULL on error. See g_resolver_lookup_service() for more
* details.
*
* Since: 2.22
*/
GList *
g_resolver_lookup_service_finish (GResolver *resolver,
GAsyncResult *result,
GError **error)
{
g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
if (g_async_result_legacy_propagate_error (result, error))
return NULL;
return G_RESOLVER_GET_CLASS (resolver)->
lookup_service_finish (resolver, result, error);
}
/**
* g_resolver_free_targets: (skip)
* @targets: a #GList of #GSrvTarget
*
* Frees @targets (which should be the return value from
* g_resolver_lookup_service() or g_resolver_lookup_service_finish()).
* (This is a convenience method; you can also simply free the
* results by hand.)
*
* Since: 2.22
*/
void
g_resolver_free_targets (GList *targets)
{
GList *t;
for (t = targets; t; t = t->next)
g_srv_target_free (t->data);
g_list_free (targets);
}
/**
* g_resolver_lookup_records:
* @resolver: a #GResolver
* @rrname: the DNS name to lookup the record for
* @record_type: the type of DNS record to lookup
* @cancellable: (allow-none): a #GCancellable, or %NULL
* @error: return location for a #GError, or %NULL
*
* Synchronously performs a DNS record lookup for the given @rrname and returns
* a list of records as #GVariant tuples. See #GResolverRecordType for
* information on what the records contain for each @record_type.
*
* If the DNS resolution fails, @error (if non-%NULL) will be set to
* a value from #GResolverError and %NULL will be returned.
*
* If @cancellable is non-%NULL, it can be used to cancel the
* operation, in which case @error (if non-%NULL) will be set to
* %G_IO_ERROR_CANCELLED.
*
* Returns: (element-type GVariant) (transfer full): a non-empty #GList of
* #GVariant, or %NULL on error. You must free each of the records and the list
* when you are done with it. (You can use g_list_free_full() with
* g_variant_unref() to do this.)
*
* Since: 2.34
*/
GList *
g_resolver_lookup_records (GResolver *resolver,
const gchar *rrname,
GResolverRecordType record_type,
GCancellable *cancellable,
GError **error)
{
GList *records;
g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
g_return_val_if_fail (rrname != NULL, NULL);
g_resolver_maybe_reload (resolver);
records = G_RESOLVER_GET_CLASS (resolver)->
lookup_records (resolver, rrname, record_type, cancellable, error);
return records;
}
/**
* g_resolver_lookup_records_async:
* @resolver: a #GResolver
* @rrname: the DNS name to lookup the record for
* @record_type: the type of DNS record to lookup
* @cancellable: (allow-none): a #GCancellable, or %NULL
* @callback: (scope async): callback to call after resolution completes
* @user_data: (closure): data for @callback
*
* Begins asynchronously performing a DNS lookup for the given
* @rrname, and eventually calls @callback, which must call
* g_resolver_lookup_records_finish() to get the final result. See
* g_resolver_lookup_records() for more details.
*
* Since: 2.34
*/
void
g_resolver_lookup_records_async (GResolver *resolver,
const gchar *rrname,
GResolverRecordType record_type,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
g_return_if_fail (G_IS_RESOLVER (resolver));
g_return_if_fail (rrname != NULL);
g_resolver_maybe_reload (resolver);
G_RESOLVER_GET_CLASS (resolver)->
lookup_records_async (resolver, rrname, record_type, cancellable, callback, user_data);
}
/**
* g_resolver_lookup_records_finish:
* @resolver: a #GResolver
* @result: the result passed to your #GAsyncReadyCallback
* @error: return location for a #GError, or %NULL
*
* Retrieves the result of a previous call to
* g_resolver_lookup_records_async(). Returns a non-empty list of records as
* #GVariant tuples. See #GResolverRecordType for information on what the
* records contain.
*
* If the DNS resolution failed, @error (if non-%NULL) will be set to
* a value from #GResolverError. If the operation was cancelled,
* @error will be set to %G_IO_ERROR_CANCELLED.
*
* Returns: (element-type GVariant) (transfer full): a non-empty #GList of
* #GVariant, or %NULL on error. You must free each of the records and the list
* when you are done with it. (You can use g_list_free_full() with
* g_variant_unref() to do this.)
*
* Since: 2.34
*/
GList *
g_resolver_lookup_records_finish (GResolver *resolver,
GAsyncResult *result,
GError **error)
{
g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
return G_RESOLVER_GET_CLASS (resolver)->
lookup_records_finish (resolver, result, error);
}
guint64
g_resolver_get_serial (GResolver *resolver)
{
g_return_val_if_fail (G_IS_RESOLVER (resolver), 0);
g_resolver_maybe_reload (resolver);
#ifdef G_OS_UNIX
return (guint64) resolver->priv->resolv_conf_timestamp;
#else
return 1;
#endif
}
/**
* g_resolver_error_quark:
*
* Gets the #GResolver Error Quark.
*
* Returns: a #GQuark.
*
* Since: 2.22
*/
G_DEFINE_QUARK (g-resolver-error-quark, g_resolver_error)