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 int udev_builtin_hwdb_lookup(struct udev_device *dev, const char *modalias, bool test) {
  33         struct udev_list_entry *entry;
  34         int n = 0;
  35
  36         if (!hwdb)
  37                 return -ENOENT;
  38
  39         udev_list_entry_foreach(entry, udev_hwdb_get_properties_list_entry(hwdb, modalias, 0)) {
  40                 if (udev_builtin_add_property(dev, test,
  41                                               udev_list_entry_get_name(entry),
  42                                               udev_list_entry_get_value(entry)) < 0)
  43                         return -ENOMEM;
  44                 n++;
  45         }
  46         return n;
  47 }
  48
  49 static const char *modalias_usb(struct udev_device *dev, char *s, size_t size) {
  50         const char *v, *p;
  51         int vn, pn;
  52
  53         v = udev_device_get_sysattr_value(dev, "idVendor");
  54         if (!v)
  55                 return NULL;
  56         p = udev_device_get_sysattr_value(dev, "idProduct");
  57         if (!p)
  58                 return NULL;
  59         vn = strtol(v, NULL, 16);
  60         if (vn <= 0)
  61                 return NULL;
  62         pn = strtol(p, NULL, 16);
  63         if (pn <= 0)
  64                 return NULL;
  65         snprintf(s, size, "usb:v%04Xp%04X*", vn, pn);
  66         return s;
  67 }
  68
  69 static int udev_builtin_hwdb_search(struct udev_device *dev, const char *subsystem, bool test) {
  70         struct udev_device *d;
  71         char s[16];
  72         int n = 0;
  73
  74         for (d = dev; d; d = udev_device_get_parent(d)) {
  75                 const char *dsubsys;
  76                 const char *modalias = NULL;
  77
  78                 dsubsys = udev_device_get_subsystem(d);
  79                 if (!dsubsys)
  80                         continue;
  81
  82                 /* look only at devices of a specific subsystem */
  83                 if (subsystem && !streq(dsubsys, subsystem))
  84                         continue;
  85
  86                 /* the usb_device does not have a modalias, compose one */
  87                 if (streq(dsubsys, "usb"))
  88                         modalias = modalias_usb(dev, s, sizeof(s));
  89
  90                 if (!modalias)
  91                         modalias = udev_device_get_property_value(d, "MODALIAS");
  92
  93                 if (!modalias)
  94                         continue;
  95                 n = udev_builtin_hwdb_lookup(dev, modalias, test);
  96                 if (n > 0)
  97                         break;
  98         }
  99
 100         return n;
 101 }
 102
 103 static int builtin_hwdb(struct udev_device *dev, int argc, char *argv[], bool test) {
 104         static const struct option options[] = {
 105                 { "subsystem", required_argument, NULL, 's' },
 106                 {}
 107         };
 108         const char *subsystem = NULL;
 109
 110         if (!hwdb)
 111                 return EXIT_FAILURE;
 112
 113         for (;;) {
 114                 int option;
 115
 116                 option = getopt_long(argc, argv, "s", options, NULL);
 117                 if (option == -1)
 118                         break;
 119
 120                 switch (option) {
 121                 case 's':
 122                         subsystem = optarg;
 123                         break;
 124                 }
 125         }
 126
 127         if (udev_builtin_hwdb_search(dev, subsystem, test) < 0)
 128                 return EXIT_FAILURE;
 129         return EXIT_SUCCESS;
 130 }
 131
 132 /* called at udev startup and reload */
 133 static int builtin_hwdb_init(struct udev *udev)
 134 {
 135         if (hwdb)
 136                 return 0;
 137         hwdb = udev_hwdb_new(udev);
 138         if (!hwdb)
 139                 return -ENOMEM;
 140         return 0;
 141 }
 142
 143 /* called on udev shutdown and reload request */
 144 static void builtin_hwdb_exit(struct udev *udev)
 145 {
 146         hwdb = udev_hwdb_unref(hwdb);
 147 }
 148
 149 /* called every couple of seconds during event activity; 'true' if config has changed */
 150 static bool builtin_hwdb_validate(struct udev *udev)
 151 {
 152         return udev_hwdb_validate(hwdb);
 153 }
 154
 155 const struct udev_builtin udev_builtin_hwdb = {
 156         .name = "hwdb",
 157         .cmd = builtin_hwdb,
 158         .init = builtin_hwdb_init,
 159         .exit = builtin_hwdb_exit,
 160         .validate = builtin_hwdb_validate,
 161         .help = "hardware database",
 162 };