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Diffstat (limited to 'extras/gudev/gudevclient.c')
| -rw-r--r-- | extras/gudev/gudevclient.c | 502 |
1 files changed, 502 insertions, 0 deletions
diff --git a/extras/gudev/gudevclient.c b/extras/gudev/gudevclient.c new file mode 100644 index 0000000000..bb6d67326f --- /dev/null +++ b/extras/gudev/gudevclient.c @@ -0,0 +1,502 @@ +/* -*- Mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- + * + * Copyright (C) 2008 David Zeuthen <davidz@redhat.com> + * + * 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, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + * + */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include <stdlib.h> +#include <string.h> + +#include "gudevclient.h" +#include "gudevdevice.h" +#include "gudevmarshal.h" +#include "gudevprivate.h" + +/** + * SECTION:gudevclient + * @short_description: Query devices and listen to uevents + * + * #GUdevClient is used to query information about devices on a Linux + * system from the Linux kernel and the udev device + * manager. + * + * Device information is retrieved from the kernel (through the + * <literal>sysfs</literal> filesystem) and the udev daemon (through a + * <literal>tmpfs</literal> filesystem) and presented through + * #GUdevDevice objects. This means that no blocking IO ever happens + * (in both cases, we are essentially just reading data from kernel + * memory) and as such there are no asynchronous versions of the + * provided methods. + * + * To get information about a device, use + * g_udev_client_query_by_subsystem(), + * g_udev_client_query_by_device_number(), + * g_udev_client_query_by_device_file(), + * g_udev_client_query_by_sysfs_path() or + * g_udev_client_query_by_subsystem_and_name(). + * + * To listen to uevents, connect to the #GUdevClient::uevent signal. + */ + +struct _GUdevClientPrivate +{ + guint watch_id; + struct udev *udev; + struct udev_monitor *monitor; + + gchar **subsystems; +}; + +enum +{ + PROP_0, + PROP_SUBSYSTEMS, +}; + +enum +{ + UEVENT_SIGNAL, + LAST_SIGNAL, +}; + +static guint signals[LAST_SIGNAL] = { 0 }; + +G_DEFINE_TYPE (GUdevClient, g_udev_client, G_TYPE_OBJECT) + +/* ---------------------------------------------------------------------------------------------------- */ + +static gboolean +monitor_event (GIOChannel *source, + GIOCondition condition, + gpointer data) +{ + GUdevClient *client = (GUdevClient *) data; + GUdevDevice *device; + struct udev_device *udevice; + + udevice = udev_monitor_receive_device (client->priv->monitor); + if (udevice == NULL) + goto out; + + device = _g_udev_device_new (udevice); + udev_device_unref (udevice); + g_signal_emit (client, + signals[UEVENT_SIGNAL], + 0, + g_udev_device_get_action (device), + device); + g_object_unref (device); + + out: + return TRUE; +} + +static void +g_udev_client_finalize (GObject *object) +{ + GUdevClient *client = G_UDEV_CLIENT (object); + + if (client->priv->watch_id != 0) + { + g_source_remove (client->priv->watch_id); + client->priv->watch_id = 0; + } + + if (client->priv->monitor != NULL) + { + udev_monitor_unref (client->priv->monitor); + client->priv->monitor = NULL; + } + + if (client->priv->udev != NULL) + { + udev_unref (client->priv->udev); + client->priv->udev = NULL; + } + + g_strfreev (client->priv->subsystems); + + if (G_OBJECT_CLASS (g_udev_client_parent_class)->finalize != NULL) + G_OBJECT_CLASS (g_udev_client_parent_class)->finalize (object); +} + +static void +g_udev_client_set_property (GObject *object, + guint prop_id, + const GValue *value, + GParamSpec *pspec) +{ + GUdevClient *client = G_UDEV_CLIENT (object); + + switch (prop_id) + { + case PROP_SUBSYSTEMS: + if (client->priv->subsystems != NULL) + g_strfreev (client->priv->subsystems); + client->priv->subsystems = g_strdupv (g_value_get_boxed (value)); + break; + + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); + break; + } +} + +static void +g_udev_client_get_property (GObject *object, + guint prop_id, + GValue *value, + GParamSpec *pspec) +{ + GUdevClient *client = G_UDEV_CLIENT (object); + + switch (prop_id) + { + case PROP_SUBSYSTEMS: + g_value_set_boxed (value, client->priv->subsystems); + break; + + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); + break; + } +} + +static void +g_udev_client_constructed (GObject *object) +{ + GUdevClient *client = G_UDEV_CLIENT (object); + GIOChannel *channel; + guint n; + + client->priv->udev = udev_new (); + + /* connect to event source */ + client->priv->monitor = udev_monitor_new_from_netlink (client->priv->udev, "udev"); + + //g_debug ("ss = %p", client->priv->subsystems); + + if (client->priv->subsystems != NULL) + { + /* install subsytem filters to only wake up for certain events */ + for (n = 0; client->priv->subsystems[n] != NULL; n++) + { + gchar *subsystem; + gchar *devtype; + gchar *s; + + subsystem = g_strdup (client->priv->subsystems[n]); + devtype = NULL; + + //g_debug ("s = '%s'", subsystem); + + s = strstr (subsystem, "/"); + if (s != NULL) + { + devtype = s + 1; + *s = '\0'; + } + + udev_monitor_filter_add_match_subsystem_devtype (client->priv->monitor, subsystem, devtype); + + g_free (subsystem); + } + + /* listen to events, and buffer them */ + udev_monitor_enable_receiving (client->priv->monitor); + + channel = g_io_channel_unix_new (udev_monitor_get_fd (client->priv->monitor)); + client->priv->watch_id = g_io_add_watch (channel, G_IO_IN, monitor_event, client); + g_io_channel_unref (channel); + } + + if (G_OBJECT_CLASS (g_udev_client_parent_class)->constructed != NULL) + G_OBJECT_CLASS (g_udev_client_parent_class)->constructed (object); +} + + +static void +g_udev_client_class_init (GUdevClientClass *klass) +{ + GObjectClass *gobject_class = (GObjectClass *) klass; + + gobject_class->constructed = g_udev_client_constructed; + gobject_class->set_property = g_udev_client_set_property; + gobject_class->get_property = g_udev_client_get_property; + gobject_class->finalize = g_udev_client_finalize; + + /** + * GUdevClient:subsystems: + * + * The subsystems to listen for uevents on. + * + * To listen for only a specific DEVTYPE for a given SUBSYSTEM, use + * "subsystem/devtype". For example, to only listen for uevents + * where SUBSYSTEM is usb and DEVTYPE is usb_interface, use + * "usb/usb_interface". + * + * If this property is %NULL, then no events will be reported. If + * it's the empty array, events from all subsystems will be + * reported. + */ + g_object_class_install_property (gobject_class, + PROP_SUBSYSTEMS, + g_param_spec_boxed ("subsystems", + "The subsystems to listen for changes on", + "The subsystems to listen for changes on", + G_TYPE_STRV, + G_PARAM_CONSTRUCT_ONLY | + G_PARAM_READWRITE)); + + /** + * GUdevClient::uevent: + * @client: The #GUdevClient receiving the event. + * @action: The action for the uevent e.g. "add", "remove", "change", "move", etc. + * @device: Details about the #GUdevDevice the event is for. + * + * Emitted when @client receives an uevent. + */ + signals[UEVENT_SIGNAL] = g_signal_new ("uevent", + G_TYPE_FROM_CLASS (klass), + G_SIGNAL_RUN_LAST, + G_STRUCT_OFFSET (GUdevClientClass, uevent), + NULL, + NULL, + g_udev_marshal_VOID__STRING_OBJECT, + G_TYPE_NONE, + 2, + G_TYPE_STRING, + G_UDEV_TYPE_DEVICE); + + g_type_class_add_private (klass, sizeof (GUdevClientPrivate)); +} + +static void +g_udev_client_init (GUdevClient *client) +{ + client->priv = G_TYPE_INSTANCE_GET_PRIVATE (client, + G_UDEV_TYPE_CLIENT, + GUdevClientPrivate); +} + +/** + * g_udev_client_new: + * @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. + * + * Constructs a #GUdevClient object that can be used to query + * information about devices. Connect to the #GUdevClient::uevent + * signal to listen for uevents. + * + * Returns: A new #GUdevClient object. Free with g_object_unref(). + */ +GUdevClient * +g_udev_client_new (const gchar * const *subsystems) +{ + return G_UDEV_CLIENT (g_object_new (G_UDEV_TYPE_CLIENT, "subsystems", subsystems, NULL)); +} + +/** + * g_udev_client_query_by_subsystem: + * @client: A #GUdevClient. + * @subsystem: (allow-none): The subsystem to get devices for or %NULL to get all devices. + * + * Gets all devices belonging to @subsystem. + * + * 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. + */ +GList * +g_udev_client_query_by_subsystem (GUdevClient *client, + const gchar *subsystem) +{ + struct udev_enumerate *enumerate; + struct udev_list_entry *l, *devices; + GList *ret; + + g_return_val_if_fail (G_UDEV_IS_CLIENT (client), NULL); + + ret = NULL; + + /* prepare a device scan */ + enumerate = udev_enumerate_new (client->priv->udev); + + /* filter for subsystem */ + if (subsystem != NULL) + udev_enumerate_add_match_subsystem (enumerate, subsystem); + /* retrieve the list */ + udev_enumerate_scan_devices (enumerate); + + /* add devices to the list */ + devices = udev_enumerate_get_list_entry (enumerate); + for (l = devices; l != NULL; l = udev_list_entry_get_next (l)) + { + struct udev_device *udevice; + GUdevDevice *device; + + udevice = udev_device_new_from_syspath (udev_enumerate_get_udev (enumerate), + udev_list_entry_get_name (l)); + if (udevice == NULL) + continue; + device = _g_udev_device_new (udevice); + udev_device_unref (udevice); + ret = g_list_prepend (ret, device); + } + udev_enumerate_unref (enumerate); + + ret = g_list_reverse (ret); + + return ret; +} + +/** + * g_udev_client_query_by_device_number: + * @client: A #GUdevClient. + * @type: A value from the #GUdevDeviceType enumeration. + * @number: A device number. + * + * Looks up a device for a type and device number. + * + * Returns: A #GUdevDevice object or %NULL if the device was not found. Free with g_object_unref(). + */ +GUdevDevice * +g_udev_client_query_by_device_number (GUdevClient *client, + GUdevDeviceType type, + GUdevDeviceNumber number) +{ + struct udev_device *udevice; + GUdevDevice *device; + + g_return_val_if_fail (G_UDEV_IS_CLIENT (client), NULL); + + device = NULL; + udevice = udev_device_new_from_devnum (client->priv->udev, type, number); + + if (udevice == NULL) + goto out; + + device = _g_udev_device_new (udevice); + udev_device_unref (udevice); + + out: + return device; +} + +/** + * g_udev_client_query_by_device_file: + * @client: A #GUdevClient. + * @device_file: A device file. + * + * Looks up a device for a device file. + * + * Returns: A #GUdevDevice object or %NULL if the device was not found. Free with g_object_unref(). + */ +GUdevDevice * +g_udev_client_query_by_device_file (GUdevClient *client, + const gchar *device_file) +{ + struct stat stat_buf; + GUdevDevice *device; + + g_return_val_if_fail (G_UDEV_IS_CLIENT (client), NULL); + g_return_val_if_fail (device_file != NULL, NULL); + + device = NULL; + + if (stat (device_file, &stat_buf) != 0) + goto out; + + if (stat_buf.st_rdev == 0) + goto out; + + if (S_ISBLK (stat_buf.st_mode)) + device = g_udev_client_query_by_device_number (client, G_UDEV_DEVICE_TYPE_BLOCK, stat_buf.st_rdev); + else if (S_ISCHR (stat_buf.st_mode)) + device = g_udev_client_query_by_device_number (client, G_UDEV_DEVICE_TYPE_CHAR, stat_buf.st_rdev); + + out: + return device; +} + +/** + * g_udev_client_query_by_sysfs_path: + * @client: A #GUdevClient. + * @sysfs_path: A sysfs path. + * + * Looks up a device for a sysfs path. + * + * Returns: A #GUdevDevice object or %NULL if the device was not found. Free with g_object_unref(). + */ +GUdevDevice * +g_udev_client_query_by_sysfs_path (GUdevClient *client, + const gchar *sysfs_path) +{ + struct udev_device *udevice; + GUdevDevice *device; + + g_return_val_if_fail (G_UDEV_IS_CLIENT (client), NULL); + g_return_val_if_fail (sysfs_path != NULL, NULL); + + device = NULL; + udevice = udev_device_new_from_syspath (client->priv->udev, sysfs_path); + if (udevice == NULL) + goto out; + + device = _g_udev_device_new (udevice); + udev_device_unref (udevice); + + out: + return device; +} + +/** + * g_udev_client_query_by_subsystem_and_name: + * @client: A #GUdevClient. + * @subsystem: A subsystem name. + * @name: The name of the device. + * + * Looks up a device for a subsystem and name. + * + * Returns: A #GUdevDevice object or %NULL if the device was not found. Free with g_object_unref(). + */ +GUdevDevice * +g_udev_client_query_by_subsystem_and_name (GUdevClient *client, + const gchar *subsystem, + const gchar *name) +{ + struct udev_device *udevice; + GUdevDevice *device; + + g_return_val_if_fail (G_UDEV_IS_CLIENT (client), NULL); + g_return_val_if_fail (subsystem != NULL, NULL); + g_return_val_if_fail (name != NULL, NULL); + + device = NULL; + udevice = udev_device_new_from_subsystem_sysname (client->priv->udev, subsystem, name); + if (udevice == NULL) + goto out; + + device = _g_udev_device_new (udevice); + udev_device_unref (udevice); + + out: + return device; +} + |