1 /* -*- Mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
3 * Copyright (C) 2008 David Zeuthen <davidz@redhat.com>
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 * Boston, MA 02111-1307, USA.
29 #include "gudevclient.h"
30 #include "gudevdevice.h"
31 #include "gudevmarshal.h"
32 #include "gudevprivate.h"
36 * @short_description: Query devices and listen to uevents
38 * #GUdevClient is used to query information about devices on a Linux
39 * system from the Linux kernel and the udev device
42 * Device information is retrieved from the kernel (through the
43 * <literal>sysfs</literal> filesystem) and the udev daemon (through a
44 * <literal>tmpfs</literal> filesystem) and presented through
45 * #GUdevDevice objects. This means that no blocking IO ever happens
46 * (in both cases, we are essentially just reading data from kernel
47 * memory) and as such there are no asynchronous versions of the
50 * To get information about a device, use
51 * g_udev_client_query_by_subsystem(),
52 * g_udev_client_query_by_device_number(),
53 * g_udev_client_query_by_device_file(),
54 * g_udev_client_query_by_sysfs_path() or
55 * g_udev_client_query_by_subsystem_and_name().
57 * To listen to uevents, connect to the #GUdevClient::uevent signal.
60 struct _GUdevClientPrivate
64 struct udev_monitor *monitor;
81 static guint signals[LAST_SIGNAL] = { 0 };
83 G_DEFINE_TYPE (GUdevClient, g_udev_client, G_TYPE_OBJECT)
85 /* ---------------------------------------------------------------------------------------------------- */
88 monitor_event (GIOChannel *source,
89 GIOCondition condition,
92 GUdevClient *client = (GUdevClient *) data;
94 struct udev_device *udevice;
96 udevice = udev_monitor_receive_device (client->priv->monitor);
100 device = _g_udev_device_new (udevice);
101 udev_device_unref (udevice);
102 g_signal_emit (client,
103 signals[UEVENT_SIGNAL],
105 g_udev_device_get_action (device),
107 g_object_unref (device);
114 g_udev_client_finalize (GObject *object)
116 GUdevClient *client = G_UDEV_CLIENT (object);
118 if (client->priv->watch_id != 0)
120 g_source_remove (client->priv->watch_id);
121 client->priv->watch_id = 0;
124 if (client->priv->monitor != NULL)
126 udev_monitor_unref (client->priv->monitor);
127 client->priv->monitor = NULL;
130 if (client->priv->udev != NULL)
132 udev_unref (client->priv->udev);
133 client->priv->udev = NULL;
136 g_strfreev (client->priv->subsystems);
138 if (G_OBJECT_CLASS (g_udev_client_parent_class)->finalize != NULL)
139 G_OBJECT_CLASS (g_udev_client_parent_class)->finalize (object);
143 g_udev_client_set_property (GObject *object,
148 GUdevClient *client = G_UDEV_CLIENT (object);
152 case PROP_SUBSYSTEMS:
153 if (client->priv->subsystems != NULL)
154 g_strfreev (client->priv->subsystems);
155 client->priv->subsystems = g_strdupv (g_value_get_boxed (value));
159 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
165 g_udev_client_get_property (GObject *object,
170 GUdevClient *client = G_UDEV_CLIENT (object);
174 case PROP_SUBSYSTEMS:
175 g_value_set_boxed (value, client->priv->subsystems);
179 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
185 g_udev_client_constructed (GObject *object)
187 GUdevClient *client = G_UDEV_CLIENT (object);
191 client->priv->udev = udev_new ();
193 /* connect to event source */
194 client->priv->monitor = udev_monitor_new_from_netlink (client->priv->udev, "udev");
196 //g_debug ("ss = %p", client->priv->subsystems);
198 if (client->priv->subsystems != NULL)
200 /* install subsystem filters to only wake up for certain events */
201 for (n = 0; client->priv->subsystems[n] != NULL; n++)
207 subsystem = g_strdup (client->priv->subsystems[n]);
210 //g_debug ("s = '%s'", subsystem);
212 s = strstr (subsystem, "/");
219 udev_monitor_filter_add_match_subsystem_devtype (client->priv->monitor, subsystem, devtype);
224 /* listen to events, and buffer them */
225 udev_monitor_enable_receiving (client->priv->monitor);
227 channel = g_io_channel_unix_new (udev_monitor_get_fd (client->priv->monitor));
228 client->priv->watch_id = g_io_add_watch (channel, G_IO_IN, monitor_event, client);
229 g_io_channel_unref (channel);
232 if (G_OBJECT_CLASS (g_udev_client_parent_class)->constructed != NULL)
233 G_OBJECT_CLASS (g_udev_client_parent_class)->constructed (object);
238 g_udev_client_class_init (GUdevClientClass *klass)
240 GObjectClass *gobject_class = (GObjectClass *) klass;
242 gobject_class->constructed = g_udev_client_constructed;
243 gobject_class->set_property = g_udev_client_set_property;
244 gobject_class->get_property = g_udev_client_get_property;
245 gobject_class->finalize = g_udev_client_finalize;
248 * GUdevClient:subsystems:
250 * The subsystems to listen for uevents on.
252 * To listen for only a specific DEVTYPE for a given SUBSYSTEM, use
253 * "subsystem/devtype". For example, to only listen for uevents
254 * where SUBSYSTEM is usb and DEVTYPE is usb_interface, use
255 * "usb/usb_interface".
257 * If this property is %NULL, then no events will be reported. If
258 * it's the empty array, events from all subsystems will be
261 g_object_class_install_property (gobject_class,
263 g_param_spec_boxed ("subsystems",
264 "The subsystems to listen for changes on",
265 "The subsystems to listen for changes on",
267 G_PARAM_CONSTRUCT_ONLY |
271 * GUdevClient::uevent:
272 * @client: The #GUdevClient receiving the event.
273 * @action: The action for the uevent e.g. "add", "remove", "change", "move", etc.
274 * @device: Details about the #GUdevDevice the event is for.
276 * Emitted when @client receives an uevent.
278 signals[UEVENT_SIGNAL] = g_signal_new ("uevent",
279 G_TYPE_FROM_CLASS (klass),
281 G_STRUCT_OFFSET (GUdevClientClass, uevent),
284 g_udev_marshal_VOID__STRING_OBJECT,
290 g_type_class_add_private (klass, sizeof (GUdevClientPrivate));
294 g_udev_client_init (GUdevClient *client)
296 client->priv = G_TYPE_INSTANCE_GET_PRIVATE (client,
303 * @subsystems: (allow-none): A %NULL terminated string array of subsystems to listen for uevents on, %NULL to not listen on uevents at all, or an empty array to listen to uevents on all subsystems. See the documentation for the #GUdevClient:subsystems property for details on this parameter.
305 * Constructs a #GUdevClient object that can be used to query
306 * information about devices. Connect to the #GUdevClient::uevent
307 * signal to listen for uevents.
309 * Returns: A new #GUdevClient object. Free with g_object_unref().
312 g_udev_client_new (const gchar * const *subsystems)
314 return G_UDEV_CLIENT (g_object_new (G_UDEV_TYPE_CLIENT, "subsystems", subsystems, NULL));
318 * g_udev_client_query_by_subsystem:
319 * @client: A #GUdevClient.
320 * @subsystem: (allow-none): The subsystem to get devices for or %NULL to get all devices.
322 * Gets all devices belonging to @subsystem.
324 * Returns: (element-type GUdevDevice): A list of #GUdevDevice objects. The caller should free the result by using g_object_unref() on each element in the list and then g_list_free() on the list.
327 g_udev_client_query_by_subsystem (GUdevClient *client,
328 const gchar *subsystem)
330 struct udev_enumerate *enumerate;
331 struct udev_list_entry *l, *devices;
334 g_return_val_if_fail (G_UDEV_IS_CLIENT (client), NULL);
338 /* prepare a device scan */
339 enumerate = udev_enumerate_new (client->priv->udev);
341 /* filter for subsystem */
342 if (subsystem != NULL)
343 udev_enumerate_add_match_subsystem (enumerate, subsystem);
344 /* retrieve the list */
345 udev_enumerate_scan_devices (enumerate);
347 /* add devices to the list */
348 devices = udev_enumerate_get_list_entry (enumerate);
349 for (l = devices; l != NULL; l = udev_list_entry_get_next (l))
351 struct udev_device *udevice;
354 udevice = udev_device_new_from_syspath (udev_enumerate_get_udev (enumerate),
355 udev_list_entry_get_name (l));
358 device = _g_udev_device_new (udevice);
359 udev_device_unref (udevice);
360 ret = g_list_prepend (ret, device);
362 udev_enumerate_unref (enumerate);
364 ret = g_list_reverse (ret);
370 * g_udev_client_query_by_device_number:
371 * @client: A #GUdevClient.
372 * @type: A value from the #GUdevDeviceType enumeration.
373 * @number: A device number.
375 * Looks up a device for a type and device number.
377 * Returns: A #GUdevDevice object or %NULL if the device was not found. Free with g_object_unref().
380 g_udev_client_query_by_device_number (GUdevClient *client,
381 GUdevDeviceType type,
382 GUdevDeviceNumber number)
384 struct udev_device *udevice;
387 g_return_val_if_fail (G_UDEV_IS_CLIENT (client), NULL);
390 udevice = udev_device_new_from_devnum (client->priv->udev, type, number);
395 device = _g_udev_device_new (udevice);
396 udev_device_unref (udevice);
403 * g_udev_client_query_by_device_file:
404 * @client: A #GUdevClient.
405 * @device_file: A device file.
407 * Looks up a device for a device file.
409 * Returns: A #GUdevDevice object or %NULL if the device was not found. Free with g_object_unref().
412 g_udev_client_query_by_device_file (GUdevClient *client,
413 const gchar *device_file)
415 struct stat stat_buf;
418 g_return_val_if_fail (G_UDEV_IS_CLIENT (client), NULL);
419 g_return_val_if_fail (device_file != NULL, NULL);
423 if (stat (device_file, &stat_buf) != 0)
426 if (stat_buf.st_rdev == 0)
429 if (S_ISBLK (stat_buf.st_mode))
430 device = g_udev_client_query_by_device_number (client, G_UDEV_DEVICE_TYPE_BLOCK, stat_buf.st_rdev);
431 else if (S_ISCHR (stat_buf.st_mode))
432 device = g_udev_client_query_by_device_number (client, G_UDEV_DEVICE_TYPE_CHAR, stat_buf.st_rdev);
439 * g_udev_client_query_by_sysfs_path:
440 * @client: A #GUdevClient.
441 * @sysfs_path: A sysfs path.
443 * Looks up a device for a sysfs path.
445 * Returns: A #GUdevDevice object or %NULL if the device was not found. Free with g_object_unref().
448 g_udev_client_query_by_sysfs_path (GUdevClient *client,
449 const gchar *sysfs_path)
451 struct udev_device *udevice;
454 g_return_val_if_fail (G_UDEV_IS_CLIENT (client), NULL);
455 g_return_val_if_fail (sysfs_path != NULL, NULL);
458 udevice = udev_device_new_from_syspath (client->priv->udev, sysfs_path);
462 device = _g_udev_device_new (udevice);
463 udev_device_unref (udevice);
470 * g_udev_client_query_by_subsystem_and_name:
471 * @client: A #GUdevClient.
472 * @subsystem: A subsystem name.
473 * @name: The name of the device.
475 * Looks up a device for a subsystem and name.
477 * Returns: A #GUdevDevice object or %NULL if the device was not found. Free with g_object_unref().
480 g_udev_client_query_by_subsystem_and_name (GUdevClient *client,
481 const gchar *subsystem,
484 struct udev_device *udevice;
487 g_return_val_if_fail (G_UDEV_IS_CLIENT (client), NULL);
488 g_return_val_if_fail (subsystem != NULL, NULL);
489 g_return_val_if_fail (name != NULL, NULL);
492 udevice = udev_device_new_from_subsystem_sysname (client->priv->udev, subsystem, name);
496 device = _g_udev_device_new (udevice);
497 udev_device_unref (udevice);