/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* GIO - GLib Input, Output and Streaming Library
*
* Copyright (C) 2008 Red Hat, Inc.
* Copyright (C) 2018 Igalia S.L.
*
* 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 2.1 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 .
*/
#include "config.h"
#include
#include "glibintl.h"
#include "gresolver.h"
#include "gnetworkingprivate.h"
#include "gasyncresult.h"
#include "ginetaddress.h"
#include "gtask.h"
#include "gsrvtarget.h"
#include "gthreadedresolver.h"
#include "gioerror.h"
#include "gcancellable.h"
#ifdef G_OS_UNIX
#include
#endif
#include
/**
* 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
GMutex mutex;
time_t resolv_conf_timestamp; /* protected by @mutex */
#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_finalize (GObject *object)
{
#ifdef G_OS_UNIX
GResolver *resolver = G_RESOLVER (object);
g_mutex_clear (&resolver->priv->mutex);
#endif
G_OBJECT_CLASS (g_resolver_parent_class)->finalize (object);
}
static void
g_resolver_class_init (GResolverClass *resolver_class)
{
GObjectClass *object_class = G_OBJECT_CLASS (resolver_class);
object_class->finalize = g_resolver_finalize;
/* 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,
NULL,
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;
g_mutex_init (&resolver->priv->mutex);
#endif
}
G_LOCK_DEFINE_STATIC (default_resolver);
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)
{
GResolver *ret;
G_LOCK (default_resolver);
if (!default_resolver)
default_resolver = g_object_new (G_TYPE_THREADED_RESOLVER, NULL);
ret = g_object_ref (default_resolver);
G_UNLOCK (default_resolver);
return ret;
}
/**
* 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)
{
G_LOCK (default_resolver);
if (default_resolver)
g_object_unref (default_resolver);
default_resolver = g_object_ref (resolver);
G_UNLOCK (default_resolver);
}
static void
maybe_emit_reload (GResolver *resolver)
{
#ifdef G_OS_UNIX
struct stat st;
if (stat (_PATH_RESCONF, &st) == 0)
{
g_mutex_lock (&resolver->priv->mutex);
if (st.st_mtime != resolver->priv->resolv_conf_timestamp)
{
resolver->priv->resolv_conf_timestamp = st.st_mtime;
g_mutex_unlock (&resolver->priv->mutex);
g_signal_emit (resolver, signals[RELOAD], 0);
}
else
g_mutex_unlock (&resolver->priv->mutex);
}
#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);
}
}
}
}
static gboolean
hostname_is_localhost (const char *hostname)
{
size_t len = strlen (hostname);
const char *p;
/* Match "localhost", "localhost.", "*.localhost" and "*.localhost." */
if (len < strlen ("localhost"))
return FALSE;
if (hostname[len - 1] == '.')
len--;
/* Scan backwards in @hostname to find the right-most dot (excluding the final dot, if it exists, as it was chopped off above).
* We can’t use strrchr() because because we need to operate with string lengths.
* End with @p pointing to the character after the right-most dot. */
p = hostname + len - 1;
while (p >= hostname)
{
if (*p == '.')
{
p++;
break;
}
else if (p == hostname)
break;
p--;
}
len -= p - hostname;
return g_ascii_strncasecmp (p, "localhost", MAX (len, strlen ("localhost"))) == 0;
}
/* 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_or_localhost (const char *hostname,
GList **addrs,
GResolverNameLookupFlags flags,
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
{
#ifdef G_OS_WIN32
gchar *error_message = g_win32_error_message (WSAHOST_NOT_FOUND);
#else
gchar *error_message = g_locale_to_utf8 (gai_strerror (EAI_NONAME), -1, NULL, NULL, NULL);
if (error_message == NULL)
error_message = g_strdup ("[Invalid UTF-8]");
#endif
g_set_error (error, G_RESOLVER_ERROR, G_RESOLVER_ERROR_NOT_FOUND,
_("Error resolving “%s”: %s"),
hostname, error_message);
g_free (error_message);
return TRUE;
}
/* Always resolve localhost to a loopback address so it can be reliably considered secure.
This behavior is being adopted by browsers:
- https://w3c.github.io/webappsec-secure-contexts/
- https://groups.google.com/a/chromium.org/forum/#!msg/blink-dev/RC9dSw-O3fE/E3_0XaT0BAAJ
- https://chromium.googlesource.com/chromium/src.git/+/8da2a80724a9b896890602ff77ef2216cb951399
- https://bugs.webkit.org/show_bug.cgi?id=171934
- https://tools.ietf.org/html/draft-west-let-localhost-be-localhost-06
*/
if (hostname_is_localhost (hostname))
{
if (flags & G_RESOLVER_NAME_LOOKUP_FLAGS_IPV6_ONLY)
*addrs = g_list_append (*addrs, g_inet_address_new_loopback (G_SOCKET_FAMILY_IPV6));
if (flags & G_RESOLVER_NAME_LOOKUP_FLAGS_IPV4_ONLY)
*addrs = g_list_append (*addrs, g_inet_address_new_loopback (G_SOCKET_FAMILY_IPV4));
if (*addrs == NULL)
{
*addrs = g_list_append (*addrs, g_inet_address_new_loopback (G_SOCKET_FAMILY_IPV6));
*addrs = g_list_append (*addrs, g_inet_address_new_loopback (G_SOCKET_FAMILY_IPV4));
}
return TRUE;
}
return FALSE;
}
static GList *
lookup_by_name_real (GResolver *resolver,
const gchar *hostname,
GResolverNameLookupFlags flags,
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);
g_return_val_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable), NULL);
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
/* Check if @hostname is just an IP address */
if (handle_ip_address_or_localhost (hostname, &addrs, flags, error))
return addrs;
if (g_hostname_is_non_ascii (hostname))
hostname = ascii_hostname = g_hostname_to_ascii (hostname);
if (!hostname)
{
g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_FAILED,
_("Invalid hostname"));
return NULL;
}
maybe_emit_reload (resolver);
if (flags != G_RESOLVER_NAME_LOOKUP_FLAGS_DEFAULT)
{
if (!G_RESOLVER_GET_CLASS (resolver)->lookup_by_name_with_flags)
{
g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
/* Translators: The placeholder is for a function name. */
_("%s not implemented"), "lookup_by_name_with_flags");
g_free (ascii_hostname);
return NULL;
}
addrs = G_RESOLVER_GET_CLASS (resolver)->
lookup_by_name_with_flags (resolver, hostname, flags, cancellable, error);
}
else
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:
* @resolver: a #GResolver
* @hostname: the hostname to look up
* @cancellable: (nullable): 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)
{
return lookup_by_name_real (resolver,
hostname,
G_RESOLVER_NAME_LOOKUP_FLAGS_DEFAULT,
cancellable,
error);
}
/**
* g_resolver_lookup_by_name_with_flags:
* @resolver: a #GResolver
* @hostname: the hostname to look up
* @flags: extra #GResolverNameLookupFlags for the lookup
* @cancellable: (nullable): a #GCancellable, or %NULL
* @error: (nullable): return location for a #GError, or %NULL
*
* This differs from g_resolver_lookup_by_name() in that you can modify
* the lookup behavior with @flags. For example this can be used to limit
* results with %G_RESOLVER_NAME_LOOKUP_FLAGS_IPV4_ONLY.
*
* 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: 2.60
*/
GList *
g_resolver_lookup_by_name_with_flags (GResolver *resolver,
const gchar *hostname,
GResolverNameLookupFlags flags,
GCancellable *cancellable,
GError **error)
{
return lookup_by_name_real (resolver,
hostname,
flags,
cancellable,
error);
}
static void
lookup_by_name_async_real (GResolver *resolver,
const gchar *hostname,
GResolverNameLookupFlags flags,
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);
g_return_if_fail (!(flags & G_RESOLVER_NAME_LOOKUP_FLAGS_IPV4_ONLY && flags & G_RESOLVER_NAME_LOOKUP_FLAGS_IPV6_ONLY));
/* Check if @hostname is just an IP address */
if (handle_ip_address_or_localhost (hostname, &addrs, flags, &error))
{
GTask *task;
task = g_task_new (resolver, cancellable, callback, user_data);
g_task_set_source_tag (task, lookup_by_name_async_real);
g_task_set_name (task, "[gio] resolver lookup");
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);
if (!hostname)
{
GTask *task;
g_set_error_literal (&error, G_IO_ERROR, G_IO_ERROR_FAILED,
_("Invalid hostname"));
task = g_task_new (resolver, cancellable, callback, user_data);
g_task_set_source_tag (task, lookup_by_name_async_real);
g_task_set_name (task, "[gio] resolver lookup");
g_task_return_error (task, error);
g_object_unref (task);
return;
}
maybe_emit_reload (resolver);
if (flags != G_RESOLVER_NAME_LOOKUP_FLAGS_DEFAULT)
{
if (G_RESOLVER_GET_CLASS (resolver)->lookup_by_name_with_flags_async == NULL)
{
GTask *task;
g_set_error (&error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
/* Translators: The placeholder is for a function name. */
_("%s not implemented"), "lookup_by_name_with_flags_async");
task = g_task_new (resolver, cancellable, callback, user_data);
g_task_set_source_tag (task, lookup_by_name_async_real);
g_task_set_name (task, "[gio] resolver lookup");
g_task_return_error (task, error);
g_object_unref (task);
}
else
G_RESOLVER_GET_CLASS (resolver)->
lookup_by_name_with_flags_async (resolver, hostname, flags, cancellable, callback, user_data);
}
else
G_RESOLVER_GET_CLASS (resolver)->
lookup_by_name_async (resolver, hostname, cancellable, callback, user_data);
g_free (ascii_hostname);
}
static GList *
lookup_by_name_finish_real (GResolver *resolver,
GAsyncResult *result,
GError **error,
gboolean with_flags)
{
GList *addrs;
g_return_val_if_fail (G_IS_RESOLVER (resolver), NULL);
g_return_val_if_fail (G_IS_ASYNC_RESULT (result), NULL);
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
if (g_async_result_legacy_propagate_error (result, error))
return NULL;
else if (g_async_result_is_tagged (result, lookup_by_name_async_real))
{
/* Handle the stringified-IP-addr case */
return g_task_propagate_pointer (G_TASK (result), error);
}
if (with_flags)
{
g_assert (G_RESOLVER_GET_CLASS (resolver)->lookup_by_name_with_flags_finish != NULL);
addrs = G_RESOLVER_GET_CLASS (resolver)->
lookup_by_name_with_flags_finish (resolver, result, error);
}
else
addrs = G_RESOLVER_GET_CLASS (resolver)->
lookup_by_name_finish (resolver, result, error);
remove_duplicates (addrs);
return addrs;
}
/**
* g_resolver_lookup_by_name_with_flags_async:
* @resolver: a #GResolver
* @hostname: the hostname to look up the address of
* @flags: extra #GResolverNameLookupFlags for the lookup
* @cancellable: (nullable): 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_with_flags_finish() to get the result.
* See g_resolver_lookup_by_name() for more details.
*
* Since: 2.60
*/
void
g_resolver_lookup_by_name_with_flags_async (GResolver *resolver,
const gchar *hostname,
GResolverNameLookupFlags flags,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
lookup_by_name_async_real (resolver,
hostname,
flags,
cancellable,
callback,
user_data);
}
/**
* g_resolver_lookup_by_name_async:
* @resolver: a #GResolver
* @hostname: the hostname to look up the address of
* @cancellable: (nullable): 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)
{
lookup_by_name_async_real (resolver,
hostname,
0,
cancellable,
callback,
user_data);
}
/**
* 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)
{
return lookup_by_name_finish_real (resolver,
result,
error,
FALSE);
}
/**
* g_resolver_lookup_by_name_with_flags_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_with_flags_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: 2.60
*/
GList *
g_resolver_lookup_by_name_with_flags_finish (GResolver *resolver,
GAsyncResult *result,
GError **error)
{
return lookup_by_name_finish_real (resolver,
result,
error,
TRUE);
}
/**
* 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: (nullable): 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);
maybe_emit_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: (nullable): 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));
maybe_emit_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);
if (!domain)
return NULL;
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: (nullable): 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);
if (!rrname)
{
g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_FAILED,
_("Invalid domain"));
return NULL;
}
maybe_emit_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: (nullable): 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);
if (!rrname)
{
g_task_report_new_error (resolver, callback, user_data,
g_resolver_lookup_service_async,
G_IO_ERROR, G_IO_ERROR_FAILED,
_("Invalid domain"));
return;
}
maybe_emit_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 look up the record for
* @record_type: the type of DNS record to look up
* @cancellable: (nullable): 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);
maybe_emit_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 look up the record for
* @record_type: the type of DNS record to look up
* @cancellable: (nullable): 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);
maybe_emit_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)
{
guint64 result;
g_return_val_if_fail (G_IS_RESOLVER (resolver), 0);
maybe_emit_reload (resolver);
#ifdef G_OS_UNIX
g_mutex_lock (&resolver->priv->mutex);
result = resolver->priv->resolv_conf_timestamp;
g_mutex_unlock (&resolver->priv->mutex);
#else
result = 1;
#endif
return result;
}
/**
* 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)