src/udev/udev-builtin-hwdb.c

	udev-builtin-hwdb.c revision 2001208c2ab631a69896d1f670c26846b70d1fb7
/***
  This file is part of systemd.

  Copyright 2012 Kay Sievers <kay.sievers@vrfy.org>

  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 <stdio.h>
#include <errno.h>
#include <string.h>
#include <inttypes.h>
#include <ctype.h>
#include <stdlib.h>
#include <getopt.h>

#include "udev.h"

static struct udev_hwdb *hwdb;

static int builtin_hwdb(struct udev_device *dev, int argc, char *argv[], bool test) {
        static const struct option options[] = {
                { "subsystem", required_argument, NULL, 's' },
                {}
        };
        const char *subsys = NULL;
        struct udev_device *d;
        const char *modalias;
        char str[UTIL_NAME_SIZE];
        struct udev_list_entry *entry;

        if (!hwdb)
                return EXIT_FAILURE;

        for (;;) {
                int option;

                option = getopt_long(argc, argv, "s", options, NULL);
                if (option == -1)
                        break;

                switch (option) {
                case 's':
                        subsys = optarg;
                        break;
                }
        }

        /* search the first parent device with a modalias */
        for (d = dev; d; d = udev_device_get_parent(d)) {
                const char *dsubsys = udev_device_get_subsystem(d);

                /* look only at devices of a specific subsystem */
                if (subsys && dsubsys && !streq(dsubsys, subsys))
                        continue;

                modalias = udev_device_get_property_value(d, "MODALIAS");
                if (modalias)
                        break;

                /* the usb_device does not have modalias, compose one */
                if (dsubsys && streq(dsubsys, "usb")) {
                        const char *v, *p;
                        int vn, pn;

                        v = udev_device_get_sysattr_value(d, "idVendor");
                        if (!v)
                                continue;
                        p = udev_device_get_sysattr_value(d, "idProduct");
                        if (!p)
                                continue;
                        vn = strtol(v, NULL, 16);
                        if (vn <= 0)
                                continue;
                        pn = strtol(p, NULL, 16);
                        if (pn <= 0)
                                continue;
                        snprintf(str, sizeof(str), "usb:v%04Xp%04X*", vn, pn);
                        modalias = str;
                        break;
                }
        }
        if (!modalias)
                return EXIT_FAILURE;

        udev_list_entry_foreach(entry, udev_hwdb_get_properties_list_entry(hwdb, modalias, 0))
        if (udev_builtin_add_property(dev, test,
                                      udev_list_entry_get_name(entry),
                                      udev_list_entry_get_value(entry)) < 0)
                        return EXIT_FAILURE;
        return EXIT_SUCCESS;
}

/* called at udev startup and reload */
static int builtin_hwdb_init(struct udev *udev)
{
        if (hwdb)
                return 0;
        hwdb = udev_hwdb_new(udev);
        if (!hwdb)
                return -ENOMEM;
        return 0;
}

/* called on udev shutdown and reload request */
static void builtin_hwdb_exit(struct udev *udev)
{
        hwdb = udev_hwdb_unref(hwdb);
}

/* called every couple of seconds during event activity; 'true' if config has changed */
static bool builtin_hwdb_validate(struct udev *udev)
{
        return udev_hwdb_validate(hwdb);
}

const struct udev_builtin udev_builtin_hwdb = {
        .name = "hwdb",
        .cmd = builtin_hwdb,
        .init = builtin_hwdb_init,
        .exit = builtin_hwdb_exit,
        .validate = builtin_hwdb_validate,
        .help = "hardware database",
};