2 This file is part of systemd.
4 Copyright Tom Gundersen <teg@jklm.no>
6 systemd is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as published by
8 the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version.
11 systemd is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public License
17 along with systemd; If not, see <http://www.gnu.org/licenses/>.
20 #include "libudev-private.h"
22 #include "hwdb-util.h"
25 * SECTION:libudev-hwdb
26 * @short_description: retrieve properties from the hardware database
28 * Libudev hardware database interface.
34 * Opaque object representing the hardware database.
42 struct udev_list properties_list;
47 * @udev: udev library context
49 * Create a hardware database context to query properties for devices.
51 * Returns: a hwdb context.
53 _public_ struct udev_hwdb *udev_hwdb_new(struct udev *udev) {
54 _cleanup_hwdb_unref_ sd_hwdb *hwdb_internal = NULL;
55 struct udev_hwdb *hwdb;
58 assert_return(udev, NULL);
60 r = sd_hwdb_new(&hwdb_internal);
64 hwdb = new0(struct udev_hwdb, 1);
69 hwdb->hwdb = hwdb_internal;
72 udev_list_init(udev, &hwdb->properties_list, true);
81 * Take a reference of a hwdb context.
83 * Returns: the passed enumeration context
85 _public_ struct udev_hwdb *udev_hwdb_ref(struct udev_hwdb *hwdb) {
96 * Drop a reference of a hwdb context. If the refcount reaches zero,
97 * all resources of the hwdb context will be released.
101 _public_ struct udev_hwdb *udev_hwdb_unref(struct udev_hwdb *hwdb) {
105 if (hwdb->refcount > 0)
107 sd_hwdb_unref(hwdb->hwdb);
108 udev_list_cleanup(&hwdb->properties_list);
114 * udev_hwdb_get_properties_list_entry:
116 * @modalias: modalias string
119 * Lookup a matching device in the hardware database. The lookup key is a
120 * modalias string, whose formats are defined for the Linux kernel modules.
121 * Examples are: pci:v00008086d00001C2D*, usb:v04F2pB221*. The first entry
122 * of a list of retrieved properties is returned.
124 * Returns: a udev_list_entry.
126 _public_ struct udev_list_entry *udev_hwdb_get_properties_list_entry(struct udev_hwdb *hwdb, const char *modalias, unsigned int flags) {
127 const char *key, *value;
129 if (!hwdb || !modalias) {
134 udev_list_cleanup(&hwdb->properties_list);
136 SD_HWDB_FOREACH_PROPERTY(hwdb->hwdb, modalias, key, value) {
137 if (udev_list_entry_add(&hwdb->properties_list, key, value) == NULL) {
143 return udev_list_get_entry(&hwdb->properties_list);