155 lines
3.9 KiB
C
155 lines
3.9 KiB
C
/* SPDX-License-Identifier: LGPL-2.1+ */
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/***
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This file is part of systemd.
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Copyright Tom Gundersen <teg@jklm.no>
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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#include "sd-hwdb.h"
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#include "alloc-util.h"
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#include "hwdb-util.h"
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#include "libudev-private.h"
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/**
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* SECTION:libudev-hwdb
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* @short_description: retrieve properties from the hardware database
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*
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* Libudev hardware database interface.
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*/
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/**
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* udev_hwdb:
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*
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* Opaque object representing the hardware database.
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*/
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struct udev_hwdb {
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struct udev *udev;
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int refcount;
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sd_hwdb *hwdb;
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struct udev_list properties_list;
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};
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/**
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* udev_hwdb_new:
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* @udev: udev library context
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*
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* Create a hardware database context to query properties for devices.
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*
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* Returns: a hwdb context.
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**/
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_public_ struct udev_hwdb *udev_hwdb_new(struct udev *udev) {
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_cleanup_(sd_hwdb_unrefp) sd_hwdb *hwdb_internal = NULL;
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struct udev_hwdb *hwdb;
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int r;
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assert_return_errno(udev, NULL, EINVAL);
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r = sd_hwdb_new(&hwdb_internal);
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if (r < 0) {
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errno = -r;
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return NULL;
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}
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hwdb = new0(struct udev_hwdb, 1);
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if (!hwdb) {
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errno = ENOMEM;
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return NULL;
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}
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hwdb->refcount = 1;
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hwdb->hwdb = TAKE_PTR(hwdb_internal);
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udev_list_init(udev, &hwdb->properties_list, true);
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return hwdb;
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}
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/**
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* udev_hwdb_ref:
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* @hwdb: context
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*
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* Take a reference of a hwdb context.
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*
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* Returns: the passed enumeration context
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**/
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_public_ struct udev_hwdb *udev_hwdb_ref(struct udev_hwdb *hwdb) {
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if (!hwdb)
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return NULL;
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hwdb->refcount++;
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return hwdb;
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}
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/**
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* udev_hwdb_unref:
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* @hwdb: context
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*
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* Drop a reference of a hwdb context. If the refcount reaches zero,
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* all resources of the hwdb context will be released.
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*
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* Returns: #NULL
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**/
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_public_ struct udev_hwdb *udev_hwdb_unref(struct udev_hwdb *hwdb) {
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if (!hwdb)
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return NULL;
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hwdb->refcount--;
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if (hwdb->refcount > 0)
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return NULL;
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sd_hwdb_unref(hwdb->hwdb);
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udev_list_cleanup(&hwdb->properties_list);
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return mfree(hwdb);
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}
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/**
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* udev_hwdb_get_properties_list_entry:
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* @hwdb: context
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* @modalias: modalias string
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* @flags: (unused)
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*
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* Lookup a matching device in the hardware database. The lookup key is a
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* modalias string, whose formats are defined for the Linux kernel modules.
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* Examples are: pci:v00008086d00001C2D*, usb:v04F2pB221*. The first entry
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* of a list of retrieved properties is returned.
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*
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* Returns: a udev_list_entry.
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*/
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_public_ struct udev_list_entry *udev_hwdb_get_properties_list_entry(struct udev_hwdb *hwdb, const char *modalias, unsigned int flags) {
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const char *key, *value;
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struct udev_list_entry *e;
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if (!hwdb || !modalias) {
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errno = EINVAL;
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return NULL;
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}
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udev_list_cleanup(&hwdb->properties_list);
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SD_HWDB_FOREACH_PROPERTY(hwdb->hwdb, modalias, key, value) {
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if (udev_list_entry_add(&hwdb->properties_list, key, value) == NULL) {
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errno = ENOMEM;
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return NULL;
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}
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}
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e = udev_list_get_entry(&hwdb->properties_list);
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if (!e)
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errno = ENODATA;
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return e;
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}
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