/*** This file is part of systemd. Copyright Tom Gundersen <teg@jklm.no> systemd 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. systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include "libudev-private.h" #include "sd-hwdb.h" #include "hwdb-util.h" /** * SECTION:libudev-hwdb * @short_description: retrieve properties from the hardware database * * Libudev hardware database interface. */ /** * udev_hwdb: * * Opaque object representing the hardware database. */ struct udev_hwdb { struct udev *udev; int refcount; sd_hwdb *hwdb; struct udev_list properties_list; }; /** * udev_hwdb_new: * @udev: udev library context * * Create a hardware database context to query properties for devices. * * Returns: a hwdb context. **/ _public_ struct udev_hwdb *udev_hwdb_new(struct udev *udev) { _cleanup_hwdb_unref_ sd_hwdb *hwdb_internal = NULL; struct udev_hwdb *hwdb; int r; assert_return(udev, NULL); r = sd_hwdb_new(&hwdb_internal); if (r < 0) return NULL; hwdb = new0(struct udev_hwdb, 1); if (!hwdb) return NULL; hwdb->refcount = 1; hwdb->hwdb = hwdb_internal; hwdb_internal = NULL; udev_list_init(udev, &hwdb->properties_list, true); return hwdb; } /** * udev_hwdb_ref: * @hwdb: context * * Take a reference of a hwdb context. * * Returns: the passed enumeration context **/ _public_ struct udev_hwdb *udev_hwdb_ref(struct udev_hwdb *hwdb) { if (!hwdb) return NULL; hwdb->refcount++; return hwdb; } /** * udev_hwdb_unref: * @hwdb: context * * Drop a reference of a hwdb context. If the refcount reaches zero, * all resources of the hwdb context will be released. * * Returns: #NULL **/ _public_ struct udev_hwdb *udev_hwdb_unref(struct udev_hwdb *hwdb) { if (!hwdb) return NULL; hwdb->refcount--; if (hwdb->refcount > 0) return NULL; sd_hwdb_unref(hwdb->hwdb); udev_list_cleanup(&hwdb->properties_list); free(hwdb); return NULL; } /** * udev_hwdb_get_properties_list_entry: * @hwdb: context * @modalias: modalias string * @flags: (unused) * * Lookup a matching device in the hardware database. The lookup key is a * modalias string, whose formats are defined for the Linux kernel modules. * Examples are: pci:v00008086d00001C2D*, usb:v04F2pB221*. The first entry * of a list of retrieved properties is returned. * * Returns: a udev_list_entry. */ _public_ struct udev_list_entry *udev_hwdb_get_properties_list_entry(struct udev_hwdb *hwdb, const char *modalias, unsigned int flags) { const char *key, *value; if (!hwdb || !modalias) { errno = EINVAL; return NULL; } udev_list_cleanup(&hwdb->properties_list); SD_HWDB_FOREACH_PROPERTY(hwdb->hwdb, modalias, key, value) { if (udev_list_entry_add(&hwdb->properties_list, key, value) == NULL) { errno = ENOMEM; return NULL; } } return udev_list_get_entry(&hwdb->properties_list); }