glib/gio/gdbusaddress.c
Maciej S. Szmigiero 0e7bf99ec2 Use "e" mode flag in fopen () calls for race-free setting of the close-on-exec flag
All Unix CRTs examined: glibc, musl, BSDs, Apple libc, Android bionic
ignore unknown fopen () mode flags, so this flag can be added
unconditionally for Unix builds.

Only Windows CRT is intolerant of these, so the single case in
g_dbus_address_connect () where the fopen () call is shared between Unix
and Windows needs appropriate platform-specific handling.

Skipped the call sites in libcharset and xdgmime copylibs.
2023-02-21 12:42:55 +00:00

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/* GDBus - GLib D-Bus Library
*
* Copyright (C) 2008-2010 Red Hat, Inc.
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*
* 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 <http://www.gnu.org/licenses/>.
*
* Author: David Zeuthen <davidz@redhat.com>
*/
#include "config.h"
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include "gioerror.h"
#include "gdbusutils.h"
#include "gdbusaddress.h"
#include "gdbuserror.h"
#include "gioenumtypes.h"
#include "glib-private.h"
#include "gnetworkaddress.h"
#include "gsocketclient.h"
#include "giostream.h"
#include "gasyncresult.h"
#include "gtask.h"
#include "glib-private.h"
#include "gdbusprivate.h"
#include "gstdio.h"
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <sys/stat.h>
#include <sys/types.h>
#include <gio/gunixsocketaddress.h>
#ifdef G_OS_WIN32
#include <windows.h>
#endif
#ifdef G_OS_WIN32
#define FO_CLOEXEC ""
#else
#define FO_CLOEXEC "e"
#endif
#include "glibintl.h"
/**
* SECTION:gdbusaddress
* @title: D-Bus Addresses
* @short_description: D-Bus connection endpoints
* @include: gio/gio.h
*
* Routines for working with D-Bus addresses. A D-Bus address is a string
* like `unix:tmpdir=/tmp/my-app-name`. The exact format of addresses
* is explained in detail in the
* [D-Bus specification](http://dbus.freedesktop.org/doc/dbus-specification.html#addresses).
*
* TCP D-Bus connections are supported, but accessing them via a proxy is
* currently not supported.
*
* Since GLib 2.72, `unix:` addresses are supported on Windows with `AF_UNIX`
* support (Windows 10).
*/
static gchar *get_session_address_platform_specific (GError **error);
static gchar *get_session_address_dbus_launch (GError **error);
/* ---------------------------------------------------------------------------------------------------- */
/**
* g_dbus_is_address:
* @string: A string.
*
* Checks if @string is a
* [D-Bus address](https://dbus.freedesktop.org/doc/dbus-specification.html#addresses).
*
* This doesn't check if @string is actually supported by #GDBusServer
* or #GDBusConnection - use g_dbus_is_supported_address() to do more
* checks.
*
* Returns: %TRUE if @string is a valid D-Bus address, %FALSE otherwise.
*
* Since: 2.26
*/
gboolean
g_dbus_is_address (const gchar *string)
{
guint n;
gchar **a;
gboolean ret;
ret = FALSE;
g_return_val_if_fail (string != NULL, FALSE);
a = g_strsplit (string, ";", 0);
if (a[0] == NULL)
goto out;
for (n = 0; a[n] != NULL; n++)
{
if (!_g_dbus_address_parse_entry (a[n],
NULL,
NULL,
NULL))
goto out;
}
ret = TRUE;
out:
g_strfreev (a);
return ret;
}
static gboolean
is_valid_unix (const gchar *address_entry,
GHashTable *key_value_pairs,
GError **error)
{
gboolean ret;
GPtrArray *keys;
const gchar *path;
const gchar *dir;
const gchar *tmpdir;
const gchar *abstract;
ret = FALSE;
path = NULL;
dir = NULL;
tmpdir = NULL;
abstract = NULL;
keys = g_hash_table_get_keys_as_ptr_array (key_value_pairs);
for (guint i = 0; i < keys->len; ++i)
{
const gchar *key = g_ptr_array_index (keys, i);
if (g_strcmp0 (key, "path") == 0)
path = g_hash_table_lookup (key_value_pairs, key);
else if (g_strcmp0 (key, "dir") == 0)
dir = g_hash_table_lookup (key_value_pairs, key);
else if (g_strcmp0 (key, "tmpdir") == 0)
tmpdir = g_hash_table_lookup (key_value_pairs, key);
else if (g_strcmp0 (key, "abstract") == 0)
abstract = g_hash_table_lookup (key_value_pairs, key);
else if (g_strcmp0 (key, "guid") != 0)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Unsupported key “%s” in address entry “%s”"),
key,
address_entry);
goto out;
}
}
/* Exactly one key must be set */
if ((path != NULL) + (dir != NULL) + (tmpdir != NULL) + (abstract != NULL) > 1)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Meaningless key/value pair combination in address entry “%s”"),
address_entry);
goto out;
}
else if (path == NULL && dir == NULL && tmpdir == NULL && abstract == NULL)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Address “%s” is invalid (need exactly one of path, dir, tmpdir, or abstract keys)"),
address_entry);
goto out;
}
ret = TRUE;
out:
g_ptr_array_unref (keys);
return ret;
}
static gboolean
is_valid_nonce_tcp (const gchar *address_entry,
GHashTable *key_value_pairs,
GError **error)
{
gboolean ret;
GPtrArray *keys;
const gchar *host;
const gchar *port;
const gchar *family;
const gchar *nonce_file;
gint port_num;
gchar *endp;
ret = FALSE;
host = NULL;
port = NULL;
family = NULL;
nonce_file = NULL;
keys = g_hash_table_get_keys_as_ptr_array (key_value_pairs);
for (guint i = 0; i < keys->len; ++i)
{
const gchar *key = g_ptr_array_index (keys, i);
if (g_strcmp0 (key, "host") == 0)
host = g_hash_table_lookup (key_value_pairs, key);
else if (g_strcmp0 (key, "port") == 0)
port = g_hash_table_lookup (key_value_pairs, key);
else if (g_strcmp0 (key, "family") == 0)
family = g_hash_table_lookup (key_value_pairs, key);
else if (g_strcmp0 (key, "noncefile") == 0)
nonce_file = g_hash_table_lookup (key_value_pairs, key);
else if (g_strcmp0 (key, "guid") != 0)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Unsupported key “%s” in address entry “%s”"),
key,
address_entry);
goto out;
}
}
if (port != NULL)
{
port_num = strtol (port, &endp, 10);
if ((*port == '\0' || *endp != '\0') || port_num < 0 || port_num >= 65536)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Error in address “%s” — the “%s” attribute is malformed"),
address_entry, "port");
goto out;
}
}
if (family != NULL && !(g_strcmp0 (family, "ipv4") == 0 || g_strcmp0 (family, "ipv6") == 0))
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Error in address “%s” — the “%s” attribute is malformed"),
address_entry, "family");
goto out;
}
if (host != NULL)
{
/* TODO: validate host */
}
if (nonce_file != NULL && *nonce_file == '\0')
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Error in address “%s” — the “%s” attribute is malformed"),
address_entry, "noncefile");
goto out;
}
ret = TRUE;
out:
g_ptr_array_unref (keys);
return ret;
}
static gboolean
is_valid_tcp (const gchar *address_entry,
GHashTable *key_value_pairs,
GError **error)
{
gboolean ret;
GPtrArray *keys;
const gchar *host;
const gchar *port;
const gchar *family;
gint port_num;
gchar *endp;
ret = FALSE;
host = NULL;
port = NULL;
family = NULL;
keys = g_hash_table_get_keys_as_ptr_array (key_value_pairs);
for (guint i = 0; i < keys->len; ++i)
{
const gchar *key = g_ptr_array_index (keys, i);
if (g_strcmp0 (key, "host") == 0)
host = g_hash_table_lookup (key_value_pairs, key);
else if (g_strcmp0 (key, "port") == 0)
port = g_hash_table_lookup (key_value_pairs, key);
else if (g_strcmp0 (key, "family") == 0)
family = g_hash_table_lookup (key_value_pairs, key);
else if (g_strcmp0 (key, "guid") != 0)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Unsupported key “%s” in address entry “%s”"),
key,
address_entry);
goto out;
}
}
if (port != NULL)
{
port_num = strtol (port, &endp, 10);
if ((*port == '\0' || *endp != '\0') || port_num < 0 || port_num >= 65536)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Error in address “%s” — the “%s” attribute is malformed"),
address_entry, "port");
goto out;
}
}
if (family != NULL && !(g_strcmp0 (family, "ipv4") == 0 || g_strcmp0 (family, "ipv6") == 0))
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Error in address “%s” — the “%s” attribute is malformed"),
address_entry, "family");
goto out;
}
if (host != NULL)
{
/* TODO: validate host */
}
ret= TRUE;
out:
g_ptr_array_unref (keys);
return ret;
}
/**
* g_dbus_is_supported_address:
* @string: A string.
* @error: Return location for error or %NULL.
*
* Like g_dbus_is_address() but also checks if the library supports the
* transports in @string and that key/value pairs for each transport
* are valid. See the specification of the
* [D-Bus address format](https://dbus.freedesktop.org/doc/dbus-specification.html#addresses).
*
* Returns: %TRUE if @string is a valid D-Bus address that is
* supported by this library, %FALSE if @error is set.
*
* Since: 2.26
*/
gboolean
g_dbus_is_supported_address (const gchar *string,
GError **error)
{
guint n;
gchar **a;
gboolean ret;
ret = FALSE;
g_return_val_if_fail (string != NULL, FALSE);
g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
a = g_strsplit (string, ";", 0);
for (n = 0; a[n] != NULL; n++)
{
gchar *transport_name;
GHashTable *key_value_pairs;
gboolean supported;
if (!_g_dbus_address_parse_entry (a[n],
&transport_name,
&key_value_pairs,
error))
goto out;
supported = FALSE;
if (g_strcmp0 (transport_name, "unix") == 0)
supported = is_valid_unix (a[n], key_value_pairs, error);
else if (g_strcmp0 (transport_name, "tcp") == 0)
supported = is_valid_tcp (a[n], key_value_pairs, error);
else if (g_strcmp0 (transport_name, "nonce-tcp") == 0)
supported = is_valid_nonce_tcp (a[n], key_value_pairs, error);
else if (g_strcmp0 (a[n], "autolaunch:") == 0)
supported = TRUE;
else
g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
_("Unknown or unsupported transport “%s” for address “%s”"),
transport_name, a[n]);
g_free (transport_name);
g_hash_table_unref (key_value_pairs);
if (!supported)
goto out;
}
ret = TRUE;
out:
g_strfreev (a);
g_assert (ret || (!ret && (error == NULL || *error != NULL)));
return ret;
}
gboolean
_g_dbus_address_parse_entry (const gchar *address_entry,
gchar **out_transport_name,
GHashTable **out_key_value_pairs,
GError **error)
{
gboolean ret;
GHashTable *key_value_pairs;
gchar *transport_name;
gchar **kv_pairs;
const gchar *s;
guint n;
ret = FALSE;
kv_pairs = NULL;
transport_name = NULL;
key_value_pairs = NULL;
s = strchr (address_entry, ':');
if (s == NULL)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Address element “%s” does not contain a colon (:)"),
address_entry);
goto out;
}
else if (s == address_entry)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Transport name in address element “%s” must not be empty"),
address_entry);
goto out;
}
transport_name = g_strndup (address_entry, s - address_entry);
key_value_pairs = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_free);
kv_pairs = g_strsplit (s + 1, ",", 0);
for (n = 0; kv_pairs[n] != NULL; n++)
{
const gchar *kv_pair = kv_pairs[n];
gchar *key;
gchar *value;
s = strchr (kv_pair, '=');
if (s == NULL)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Key/Value pair %d, “%s”, in address element “%s” does not contain an equal sign"),
n,
kv_pair,
address_entry);
goto out;
}
else if (s == kv_pair)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Key/Value pair %d, “%s”, in address element “%s” must not have an empty key"),
n,
kv_pair,
address_entry);
goto out;
}
key = g_uri_unescape_segment (kv_pair, s, NULL);
value = g_uri_unescape_segment (s + 1, kv_pair + strlen (kv_pair), NULL);
if (key == NULL || value == NULL)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Error unescaping key or value in Key/Value pair %d, “%s”, in address element “%s”"),
n,
kv_pair,
address_entry);
g_free (key);
g_free (value);
goto out;
}
g_hash_table_insert (key_value_pairs, key, value);
}
ret = TRUE;
out:
if (ret)
{
if (out_transport_name != NULL)
*out_transport_name = g_steal_pointer (&transport_name);
if (out_key_value_pairs != NULL)
*out_key_value_pairs = g_steal_pointer (&key_value_pairs);
}
g_clear_pointer (&key_value_pairs, g_hash_table_unref);
g_free (transport_name);
g_strfreev (kv_pairs);
return ret;
}
/* ---------------------------------------------------------------------------------------------------- */
static GIOStream *
g_dbus_address_try_connect_one (const gchar *address_entry,
gchar **out_guid,
GCancellable *cancellable,
GError **error);
/* TODO: Declare an extension point called GDBusTransport (or similar)
* and move code below to extensions implementing said extension
* point. That way we can implement a D-Bus transport over X11 without
* making libgio link to libX11...
*/
static GIOStream *
g_dbus_address_connect (const gchar *address_entry,
const gchar *transport_name,
GHashTable *key_value_pairs,
GCancellable *cancellable,
GError **error)
{
GIOStream *ret;
GSocketConnectable *connectable;
const gchar *nonce_file;
connectable = NULL;
ret = NULL;
nonce_file = NULL;
if (g_strcmp0 (transport_name, "unix") == 0)
{
const gchar *path;
const gchar *abstract;
path = g_hash_table_lookup (key_value_pairs, "path");
abstract = g_hash_table_lookup (key_value_pairs, "abstract");
if ((path == NULL && abstract == NULL) || (path != NULL && abstract != NULL))
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Error in address “%s” — the unix transport requires exactly one of the "
"keys “path” or “abstract” to be set"),
address_entry);
}
else if (path != NULL)
{
connectable = G_SOCKET_CONNECTABLE (g_unix_socket_address_new (path));
}
else if (abstract != NULL)
{
connectable = G_SOCKET_CONNECTABLE (g_unix_socket_address_new_with_type (abstract,
-1,
G_UNIX_SOCKET_ADDRESS_ABSTRACT));
}
else
{
g_assert_not_reached ();
}
}
else if (g_strcmp0 (transport_name, "tcp") == 0 || g_strcmp0 (transport_name, "nonce-tcp") == 0)
{
const gchar *s;
const gchar *host;
glong port;
gchar *endp;
gboolean is_nonce;
is_nonce = (g_strcmp0 (transport_name, "nonce-tcp") == 0);
host = g_hash_table_lookup (key_value_pairs, "host");
if (host == NULL)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Error in address “%s” — the host attribute is missing or malformed"),
address_entry);
goto out;
}
s = g_hash_table_lookup (key_value_pairs, "port");
if (s == NULL)
s = "0";
port = strtol (s, &endp, 10);
if ((*s == '\0' || *endp != '\0') || port < 0 || port >= 65536)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Error in address “%s” — the port attribute is missing or malformed"),
address_entry);
goto out;
}
if (is_nonce)
{
nonce_file = g_hash_table_lookup (key_value_pairs, "noncefile");
if (nonce_file == NULL)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Error in address “%s” — the noncefile attribute is missing or malformed"),
address_entry);
goto out;
}
}
/* TODO: deal with family key/value-pair */
connectable = g_network_address_new (host, port);
}
else if (g_strcmp0 (address_entry, "autolaunch:") == 0)
{
gchar *autolaunch_address;
autolaunch_address = get_session_address_dbus_launch (error);
if (autolaunch_address != NULL)
{
ret = g_dbus_address_try_connect_one (autolaunch_address, NULL, cancellable, error);
g_free (autolaunch_address);
goto out;
}
else
{
g_prefix_error (error, _("Error auto-launching: "));
}
}
else
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Unknown or unsupported transport “%s” for address “%s”"),
transport_name,
address_entry);
}
if (connectable != NULL)
{
GSocketClient *client;
GSocketConnection *connection;
g_assert (ret == NULL);
client = g_socket_client_new ();
/* Disable proxy support to prevent a deadlock on startup, since loading a
* proxy resolver causes the GIO modules to be loaded, and there will
* almost certainly be one of them which then tries to use GDBus.
* See: https://bugzilla.gnome.org/show_bug.cgi?id=792499 */
g_socket_client_set_enable_proxy (client, FALSE);
connection = g_socket_client_connect (client,
connectable,
cancellable,
error);
g_object_unref (connectable);
g_object_unref (client);
if (connection == NULL)
goto out;
ret = G_IO_STREAM (connection);
if (nonce_file != NULL)
{
gchar nonce_contents[16 + 1];
size_t num_bytes_read;
FILE *f;
int errsv;
/* be careful to read only 16 bytes - we also check that the file is only 16 bytes long */
f = fopen (nonce_file, "rb" FO_CLOEXEC);
errsv = errno;
if (f == NULL)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Error opening nonce file “%s”: %s"),
nonce_file,
g_strerror (errsv));
g_object_unref (ret);
ret = NULL;
goto out;
}
num_bytes_read = fread (nonce_contents,
sizeof (gchar),
16 + 1,
f);
errsv = errno;
if (num_bytes_read != 16)
{
if (num_bytes_read == 0)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Error reading from nonce file “%s”: %s"),
nonce_file,
g_strerror (errsv));
}
else
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Error reading from nonce file “%s”, expected 16 bytes, got %d"),
nonce_file,
(gint) num_bytes_read);
}
g_object_unref (ret);
ret = NULL;
fclose (f);
goto out;
}
fclose (f);
if (!g_output_stream_write_all (g_io_stream_get_output_stream (ret),
nonce_contents,
16,
NULL,
cancellable,
error))
{
g_prefix_error (error, _("Error writing contents of nonce file “%s” to stream:"), nonce_file);
g_object_unref (ret);
ret = NULL;
goto out;
}
}
}
out:
return ret;
}
static GIOStream *
g_dbus_address_try_connect_one (const gchar *address_entry,
gchar **out_guid,
GCancellable *cancellable,
GError **error)
{
GIOStream *ret;
GHashTable *key_value_pairs;
gchar *transport_name;
const gchar *guid;
ret = NULL;
transport_name = NULL;
key_value_pairs = NULL;
if (!_g_dbus_address_parse_entry (address_entry,
&transport_name,
&key_value_pairs,
error))
goto out;
ret = g_dbus_address_connect (address_entry,
transport_name,
key_value_pairs,
cancellable,
error);
if (ret == NULL)
goto out;
guid = g_hash_table_lookup (key_value_pairs, "guid");
if (guid != NULL && out_guid != NULL)
*out_guid = g_strdup (guid);
out:
g_free (transport_name);
if (key_value_pairs != NULL)
g_hash_table_unref (key_value_pairs);
return ret;
}
/* ---------------------------------------------------------------------------------------------------- */
typedef struct {
gchar *address;
gchar *guid;
} GetStreamData;
static void
get_stream_data_free (GetStreamData *data)
{
g_free (data->address);
g_free (data->guid);
g_free (data);
}
static void
get_stream_thread_func (GTask *task,
gpointer source_object,
gpointer task_data,
GCancellable *cancellable)
{
GetStreamData *data = task_data;
GIOStream *stream;
GError *error = NULL;
stream = g_dbus_address_get_stream_sync (data->address,
&data->guid,
cancellable,
&error);
if (stream)
g_task_return_pointer (task, stream, g_object_unref);
else
g_task_return_error (task, error);
}
/**
* g_dbus_address_get_stream:
* @address: A valid D-Bus address.
* @cancellable: (nullable): A #GCancellable or %NULL.
* @callback: A #GAsyncReadyCallback to call when the request is satisfied.
* @user_data: Data to pass to @callback.
*
* Asynchronously connects to an endpoint specified by @address and
* sets up the connection so it is in a state to run the client-side
* of the D-Bus authentication conversation. @address must be in the
* [D-Bus address format](https://dbus.freedesktop.org/doc/dbus-specification.html#addresses).
*
* When the operation is finished, @callback will be invoked. You can
* then call g_dbus_address_get_stream_finish() to get the result of
* the operation.
*
* This is an asynchronous failable function. See
* g_dbus_address_get_stream_sync() for the synchronous version.
*
* Since: 2.26
*/
void
g_dbus_address_get_stream (const gchar *address,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
GTask *task;
GetStreamData *data;
g_return_if_fail (address != NULL);
data = g_new0 (GetStreamData, 1);
data->address = g_strdup (address);
task = g_task_new (NULL, cancellable, callback, user_data);
g_task_set_source_tag (task, g_dbus_address_get_stream);
g_task_set_task_data (task, data, (GDestroyNotify) get_stream_data_free);
g_task_run_in_thread (task, get_stream_thread_func);
g_object_unref (task);
}
/**
* g_dbus_address_get_stream_finish:
* @res: A #GAsyncResult obtained from the GAsyncReadyCallback passed to g_dbus_address_get_stream().
* @out_guid: (optional) (out) (nullable): %NULL or return location to store the GUID extracted from @address, if any.
* @error: Return location for error or %NULL.
*
* Finishes an operation started with g_dbus_address_get_stream().
*
* A server is not required to set a GUID, so @out_guid may be set to %NULL
* even on success.
*
* Returns: (transfer full): A #GIOStream or %NULL if @error is set.
*
* Since: 2.26
*/
GIOStream *
g_dbus_address_get_stream_finish (GAsyncResult *res,
gchar **out_guid,
GError **error)
{
GTask *task;
GetStreamData *data;
GIOStream *ret;
g_return_val_if_fail (g_task_is_valid (res, NULL), NULL);
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
task = G_TASK (res);
ret = g_task_propagate_pointer (task, error);
if (ret != NULL && out_guid != NULL)
{
data = g_task_get_task_data (task);
*out_guid = data->guid;
data->guid = NULL;
}
return ret;
}
/**
* g_dbus_address_get_stream_sync:
* @address: A valid D-Bus address.
* @out_guid: (optional) (out) (nullable): %NULL or return location to store the GUID extracted from @address, if any.
* @cancellable: (nullable): A #GCancellable or %NULL.
* @error: Return location for error or %NULL.
*
* Synchronously connects to an endpoint specified by @address and
* sets up the connection so it is in a state to run the client-side
* of the D-Bus authentication conversation. @address must be in the
* [D-Bus address format](https://dbus.freedesktop.org/doc/dbus-specification.html#addresses).
*
* A server is not required to set a GUID, so @out_guid may be set to %NULL
* even on success.
*
* This is a synchronous failable function. See
* g_dbus_address_get_stream() for the asynchronous version.
*
* Returns: (transfer full): A #GIOStream or %NULL if @error is set.
*
* Since: 2.26
*/
GIOStream *
g_dbus_address_get_stream_sync (const gchar *address,
gchar **out_guid,
GCancellable *cancellable,
GError **error)
{
GIOStream *ret;
gchar **addr_array;
guint n;
GError *last_error;
g_return_val_if_fail (address != NULL, NULL);
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
ret = NULL;
last_error = NULL;
addr_array = g_strsplit (address, ";", 0);
if (addr_array[0] == NULL)
{
last_error = g_error_new_literal (G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("The given address is empty"));
goto out;
}
for (n = 0; addr_array[n] != NULL; n++)
{
const gchar *addr = addr_array[n];
GError *this_error;
this_error = NULL;
ret = g_dbus_address_try_connect_one (addr,
out_guid,
cancellable,
&this_error);
if (ret != NULL)
{
goto out;
}
else
{
g_assert (this_error != NULL);
if (last_error != NULL)
g_error_free (last_error);
last_error = this_error;
}
}
out:
if (ret != NULL)
{
if (last_error != NULL)
g_error_free (last_error);
}
else
{
g_assert (last_error != NULL);
g_propagate_error (error, last_error);
}
g_strfreev (addr_array);
return ret;
}
/* ---------------------------------------------------------------------------------------------------- */
/*
* Return the address of XDG_RUNTIME_DIR/bus if it exists, belongs to
* us, and is a socket, and we are on Unix.
*/
static gchar *
get_session_address_xdg (void)
{
#ifdef G_OS_UNIX
gchar *ret = NULL;
gchar *bus;
gchar *tmp;
GStatBuf buf;
bus = g_build_filename (g_get_user_runtime_dir (), "bus", NULL);
/* if ENOENT, EPERM, etc., quietly don't use it */
if (g_stat (bus, &buf) < 0)
goto out;
/* if it isn't ours, we have incorrectly inherited someone else's
* XDG_RUNTIME_DIR; silently don't use it
*/
if (buf.st_uid != geteuid ())
goto out;
/* if it isn't a socket, silently don't use it */
if ((buf.st_mode & S_IFMT) != S_IFSOCK)
goto out;
tmp = g_dbus_address_escape_value (bus);
ret = g_strconcat ("unix:path=", tmp, NULL);
g_free (tmp);
out:
g_free (bus);
return ret;
#else
return NULL;
#endif
}
/* ---------------------------------------------------------------------------------------------------- */
#ifdef G_OS_UNIX
static gchar *
get_session_address_dbus_launch (GError **error)
{
gchar *ret;
gchar *machine_id;
gchar *command_line;
gchar *launch_stdout;
gchar *launch_stderr;
gint wait_status;
gchar *old_dbus_verbose;
gboolean restore_dbus_verbose;
ret = NULL;
machine_id = NULL;
command_line = NULL;
launch_stdout = NULL;
launch_stderr = NULL;
restore_dbus_verbose = FALSE;
old_dbus_verbose = NULL;
/* Don't run binaries as root if we're setuid. */
if (GLIB_PRIVATE_CALL (g_check_setuid) ())
{
g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
_("Cannot spawn a message bus when AT_SECURE is set"));
goto out;
}
machine_id = _g_dbus_get_machine_id (error);
if (machine_id == NULL)
{
g_prefix_error (error, _("Cannot spawn a message bus without a machine-id: "));
goto out;
}
if (g_getenv ("DISPLAY") == NULL)
{
g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
_("Cannot autolaunch D-Bus without X11 $DISPLAY"));
goto out;
}
/* We're using private libdbus facilities here. When everything
* (X11, Mac OS X, Windows) is spec'ed out correctly (not even the
* X11 property is correctly documented right now) we should
* consider using the spec instead of dbus-launch.
*
* --autolaunch=MACHINEID
* This option implies that dbus-launch should scan for a previ
* ously-started session and reuse the values found there. If no
* session is found, it will start a new session. The --exit-with-
* session option is implied if --autolaunch is given. This option
* is for the exclusive use of libdbus, you do not want to use it
* manually. It may change in the future.
*/
/* TODO: maybe provide a variable for where to look for the dbus-launch binary? */
command_line = g_strdup_printf ("dbus-launch --autolaunch=%s --binary-syntax --close-stderr", machine_id);
if (G_UNLIKELY (_g_dbus_debug_address ()))
{
_g_dbus_debug_print_lock ();
g_print ("GDBus-debug:Address: Running '%s' to get bus address (possibly autolaunching)\n", command_line);
old_dbus_verbose = g_strdup (g_getenv ("DBUS_VERBOSE"));
restore_dbus_verbose = TRUE;
g_setenv ("DBUS_VERBOSE", "1", TRUE);
_g_dbus_debug_print_unlock ();
}
if (!g_spawn_command_line_sync (command_line,
&launch_stdout,
&launch_stderr,
&wait_status,
error))
{
goto out;
}
if (!g_spawn_check_wait_status (wait_status, error))
{
g_prefix_error (error, _("Error spawning command line “%s”: "), command_line);
goto out;
}
/* From the dbus-launch(1) man page:
*
* --binary-syntax Write to stdout a nul-terminated bus address,
* then the bus PID as a binary integer of size sizeof(pid_t),
* then the bus X window ID as a binary integer of size
* sizeof(long). Integers are in the machine's byte order, not
* network byte order or any other canonical byte order.
*/
ret = g_strdup (launch_stdout);
out:
if (G_UNLIKELY (_g_dbus_debug_address ()))
{
gchar *s;
_g_dbus_debug_print_lock ();
g_print ("GDBus-debug:Address: dbus-launch output:");
if (launch_stdout != NULL)
{
s = _g_dbus_hexdump (launch_stdout, strlen (launch_stdout) + 1 + sizeof (pid_t) + sizeof (long), 2);
g_print ("\n%s", s);
g_free (s);
}
else
{
g_print (" (none)\n");
}
g_print ("GDBus-debug:Address: dbus-launch stderr output:");
if (launch_stderr != NULL)
g_print ("\n%s", launch_stderr);
else
g_print (" (none)\n");
_g_dbus_debug_print_unlock ();
}
g_free (machine_id);
g_free (command_line);
g_free (launch_stdout);
g_free (launch_stderr);
if (G_UNLIKELY (restore_dbus_verbose))
{
if (old_dbus_verbose != NULL)
g_setenv ("DBUS_VERBOSE", old_dbus_verbose, TRUE);
else
g_unsetenv ("DBUS_VERBOSE");
}
g_free (old_dbus_verbose);
return ret;
}
/* end of G_OS_UNIX case */
#elif defined(G_OS_WIN32)
static gchar *
get_session_address_dbus_launch (GError **error)
{
return _g_dbus_win32_get_session_address_dbus_launch (error);
}
#else /* neither G_OS_UNIX nor G_OS_WIN32 */
static gchar *
get_session_address_dbus_launch (GError **error)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
_("Cannot determine session bus address (not implemented for this OS)"));
return NULL;
}
#endif /* neither G_OS_UNIX nor G_OS_WIN32 */
/* ---------------------------------------------------------------------------------------------------- */
static gchar *
get_session_address_platform_specific (GError **error)
{
gchar *ret;
/* Use XDG_RUNTIME_DIR/bus if it exists and is suitable. This is appropriate
* for systems using the "a session is a user-session" model described in
* <http://lists.freedesktop.org/archives/dbus/2015-January/016522.html>,
* and implemented in dbus >= 1.9.14 and sd-bus.
*
* On systems following the more traditional "a session is a login-session"
* model, this will fail and we'll fall through to X11 autolaunching
* (dbus-launch) below.
*/
ret = get_session_address_xdg ();
if (ret != NULL)
return ret;
/* TODO (#694472): try launchd on OS X, like
* _dbus_lookup_session_address_launchd() does, since
* 'dbus-launch --autolaunch' probably won't work there
*/
/* As a last resort, try the "autolaunch:" transport. On Unix this means
* X11 autolaunching; on Windows this means a different autolaunching
* mechanism based on shared memory.
*/
return get_session_address_dbus_launch (error);
}
/* ---------------------------------------------------------------------------------------------------- */
/**
* g_dbus_address_get_for_bus_sync:
* @bus_type: a #GBusType
* @cancellable: (nullable): a #GCancellable or %NULL
* @error: return location for error or %NULL
*
* Synchronously looks up the D-Bus address for the well-known message
* bus instance specified by @bus_type. This may involve using various
* platform specific mechanisms.
*
* The returned address will be in the
* [D-Bus address format](https://dbus.freedesktop.org/doc/dbus-specification.html#addresses).
*
* Returns: (transfer full): a valid D-Bus address string for @bus_type or
* %NULL if @error is set
*
* Since: 2.26
*/
gchar *
g_dbus_address_get_for_bus_sync (GBusType bus_type,
GCancellable *cancellable,
GError **error)
{
gboolean has_elevated_privileges = GLIB_PRIVATE_CALL (g_check_setuid) ();
gchar *ret, *s = NULL;
const gchar *starter_bus;
GError *local_error;
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
ret = NULL;
local_error = NULL;
if (G_UNLIKELY (_g_dbus_debug_address ()))
{
guint n;
_g_dbus_debug_print_lock ();
s = _g_dbus_enum_to_string (G_TYPE_BUS_TYPE, bus_type);
g_print ("GDBus-debug:Address: In g_dbus_address_get_for_bus_sync() for bus type '%s'\n",
s);
g_free (s);
for (n = 0; n < 3; n++)
{
const gchar *k;
const gchar *v;
switch (n)
{
case 0: k = "DBUS_SESSION_BUS_ADDRESS"; break;
case 1: k = "DBUS_SYSTEM_BUS_ADDRESS"; break;
case 2: k = "DBUS_STARTER_BUS_TYPE"; break;
default: g_assert_not_reached ();
}
v = g_getenv (k);
g_print ("GDBus-debug:Address: env var %s", k);
if (v != NULL)
g_print ("='%s'\n", v);
else
g_print (" is not set\n");
}
_g_dbus_debug_print_unlock ();
}
/* Dont load the addresses from the environment if running as setuid, as they
* come from an unprivileged caller. */
switch (bus_type)
{
case G_BUS_TYPE_SYSTEM:
if (has_elevated_privileges)
ret = NULL;
else
ret = g_strdup (g_getenv ("DBUS_SYSTEM_BUS_ADDRESS"));
if (ret == NULL)
{
/* While the D-Bus specification says this must be `/var/run/dbus/system_bus_socket`,
* a footnote allows it to use localstatedir:
* https://dbus.freedesktop.org/doc/dbus-specification.html#ftn.id-1.13.6.4.3.3
* or, on systems where /run is the same as /var/run, runstatedir:
* https://gitlab.freedesktop.org/dbus/dbus/-/merge_requests/209 */
ret = g_strdup ("unix:path=" GLIB_RUNSTATEDIR "/dbus/system_bus_socket");
}
break;
case G_BUS_TYPE_SESSION:
if (has_elevated_privileges)
ret = NULL;
else
ret = g_strdup (g_getenv ("DBUS_SESSION_BUS_ADDRESS"));
if (ret == NULL)
{
ret = get_session_address_platform_specific (&local_error);
}
break;
case G_BUS_TYPE_STARTER:
starter_bus = g_getenv ("DBUS_STARTER_BUS_TYPE");
if (g_strcmp0 (starter_bus, "session") == 0)
{
ret = g_dbus_address_get_for_bus_sync (G_BUS_TYPE_SESSION, cancellable, &local_error);
goto out;
}
else if (g_strcmp0 (starter_bus, "system") == 0)
{
ret = g_dbus_address_get_for_bus_sync (G_BUS_TYPE_SYSTEM, cancellable, &local_error);
goto out;
}
else
{
if (starter_bus != NULL)
{
g_set_error (&local_error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
_("Cannot determine bus address from DBUS_STARTER_BUS_TYPE environment variable"
" — unknown value “%s”"),
starter_bus);
}
else
{
g_set_error_literal (&local_error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
_("Cannot determine bus address because the DBUS_STARTER_BUS_TYPE environment "
"variable is not set"));
}
}
break;
default:
g_set_error (&local_error,
G_IO_ERROR,
G_IO_ERROR_FAILED,
_("Unknown bus type %d"),
bus_type);
break;
}
out:
if (G_UNLIKELY (_g_dbus_debug_address ()))
{
_g_dbus_debug_print_lock ();
s = _g_dbus_enum_to_string (G_TYPE_BUS_TYPE, bus_type);
if (ret != NULL)
{
g_print ("GDBus-debug:Address: Returning address '%s' for bus type '%s'\n",
ret, s);
}
else
{
g_print ("GDBus-debug:Address: Cannot look-up address bus type '%s': %s\n",
s, local_error ? local_error->message : "");
}
g_free (s);
_g_dbus_debug_print_unlock ();
}
if (local_error != NULL)
g_propagate_error (error, local_error);
return ret;
}
/**
* g_dbus_address_escape_value:
* @string: an unescaped string to be included in a D-Bus address
* as the value in a key-value pair
*
* Escape @string so it can appear in a D-Bus address as the value
* part of a key-value pair.
*
* For instance, if @string is `/run/bus-for-:0`,
* this function would return `/run/bus-for-%3A0`,
* which could be used in a D-Bus address like
* `unix:nonce-tcp:host=127.0.0.1,port=42,noncefile=/run/bus-for-%3A0`.
*
* Returns: (transfer full): a copy of @string with all
* non-optionally-escaped bytes escaped
*
* Since: 2.36
*/
gchar *
g_dbus_address_escape_value (const gchar *string)
{
GString *s;
gsize i;
g_return_val_if_fail (string != NULL, NULL);
/* There will often not be anything needing escaping at all. */
s = g_string_sized_new (strlen (string));
/* D-Bus address escaping is mostly the same as URI escaping... */
g_string_append_uri_escaped (s, string, "\\/", FALSE);
/* ... but '~' is an unreserved character in URIs, but a
* non-optionally-escaped character in D-Bus addresses. */
for (i = 0; i < s->len; i++)
{
if (G_UNLIKELY (s->str[i] == '~'))
{
s->str[i] = '%';
g_string_insert (s, i + 1, "7E");
i += 2;
}
}
return g_string_free (s, FALSE);
}