src/udev/udev-builtin-hwdb.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2012 Kay Sievers <kay@vrfy.org>
   5
   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.
  10
  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.
  15
  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/>.
  18 ***/
  19
  20 #include <stdio.h>
  21 #include <errno.h>
  22 #include <string.h>
  23 #include <inttypes.h>
  24 #include <ctype.h>
  25 #include <stdlib.h>
  26 #include <getopt.h>
  27
  28 #include "udev.h"
  29
  30 static struct udev_hwdb *hwdb;
  31
  32 static int builtin_hwdb(struct udev_device *dev, int argc, char *argv[], bool test) {
  33         static const struct option options[] = {
  34                 { "subsystem", required_argument, NULL, 's' },
  35                 {}
  36         };
  37         const char *subsys = NULL;
  38         struct udev_device *d;
  39         const char *modalias;
  40         char str[UTIL_NAME_SIZE];
  41         struct udev_list_entry *entry;
  42
  43         if (!hwdb)
  44                 return EXIT_FAILURE;
  45
  46         for (;;) {
  47                 int option;
  48
  49                 option = getopt_long(argc, argv, "s", options, NULL);
  50                 if (option == -1)
  51                         break;
  52
  53                 switch (option) {
  54                 case 's':
  55                         subsys = optarg;
  56                         break;
  57                 }
  58         }
  59
  60         /* search the first parent device with a modalias */
  61         for (d = dev; d; d = udev_device_get_parent(d)) {
  62                 const char *dsubsys = udev_device_get_subsystem(d);
  63
  64                 /* look only at devices of a specific subsystem */
  65                 if (subsys && dsubsys && !streq(dsubsys, subsys))
  66                         continue;
  67
  68                 modalias = udev_device_get_property_value(d, "MODALIAS");
  69                 if (modalias)
  70                         break;
  71
  72                 /* the usb_device does not have modalias, compose one */
  73                 if (dsubsys && streq(dsubsys, "usb")) {
  74                         const char *v, *p;
  75                         int vn, pn;
  76
  77                         v = udev_device_get_sysattr_value(d, "idVendor");
  78                         if (!v)
  79                                 continue;
  80                         p = udev_device_get_sysattr_value(d, "idProduct");
  81                         if (!p)
  82                                 continue;
  83                         vn = strtol(v, NULL, 16);
  84                         if (vn <= 0)
  85                                 continue;
  86                         pn = strtol(p, NULL, 16);
  87                         if (pn <= 0)
  88                                 continue;
  89                         snprintf(str, sizeof(str), "usb:v%04Xp%04X*", vn, pn);
  90                         modalias = str;
  91                         break;
  92                 }
  93         }
  94         if (!modalias)
  95                 return EXIT_FAILURE;
  96
  97         udev_list_entry_foreach(entry, udev_hwdb_get_properties_list_entry(hwdb, modalias, 0))
  98         if (udev_builtin_add_property(dev, test,
  99                                       udev_list_entry_get_name(entry),
 100                                       udev_list_entry_get_value(entry)) < 0)
 101                         return EXIT_FAILURE;
 102         return EXIT_SUCCESS;
 103 }
 104
 105 /* called at udev startup and reload */
 106 static int builtin_hwdb_init(struct udev *udev)
 107 {
 108         if (hwdb)
 109                 return 0;
 110         hwdb = udev_hwdb_new(udev);
 111         if (!hwdb)
 112                 return -ENOMEM;
 113         return 0;
 114 }
 115
 116 /* called on udev shutdown and reload request */
 117 static void builtin_hwdb_exit(struct udev *udev)
 118 {
 119         hwdb = udev_hwdb_unref(hwdb);
 120 }
 121
 122 /* called every couple of seconds during event activity; 'true' if config has changed */
 123 static bool builtin_hwdb_validate(struct udev *udev)
 124 {
 125         return udev_hwdb_validate(hwdb);
 126 }
 127
 128 const struct udev_builtin udev_builtin_hwdb = {
 129         .name = "hwdb",
 130         .cmd = builtin_hwdb,
 131         .init = builtin_hwdb_init,
 132         .exit = builtin_hwdb_exit,
 133         .validate = builtin_hwdb_validate,
 134         .help = "hardware database",
 135 };