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 <fnmatch.h>
  27 #include <getopt.h>
  28
  29 #include "udev.h"
  30
  31 static struct udev_hwdb *hwdb;
  32
  33 int udev_builtin_hwdb_lookup(struct udev_device *dev,
  34                              const char *prefix, const char *modalias,
  35                              const char *filter, bool test) {
  36         struct udev_list_entry *list;
  37         struct udev_list_entry *entry;
  38         int n = 0;
  39
  40         if (!hwdb)
  41                 return -ENOENT;
  42
  43         if (prefix) {
  44                 _cleanup_free_ const char *lookup;
  45
  46                 lookup = strjoin(prefix, modalias, NULL);
  47                 if (!lookup)
  48                         return -ENOMEM;
  49                 list = udev_hwdb_get_properties_list_entry(hwdb, lookup, 0);
  50         } else
  51                 list = udev_hwdb_get_properties_list_entry(hwdb, modalias, 0);
  52
  53         udev_list_entry_foreach(entry, list) {
  54                 if (filter && fnmatch(filter, udev_list_entry_get_name(entry), FNM_NOESCAPE) != 0)
  55                         continue;
  56
  57                 if (udev_builtin_add_property(dev, test,
  58                                               udev_list_entry_get_name(entry),
  59                                               udev_list_entry_get_value(entry)) < 0)
  60                         return -ENOMEM;
  61                 n++;
  62         }
  63         return n;
  64 }
  65
  66 static const char *modalias_usb(struct udev_device *dev, char *s, size_t size) {
  67         const char *v, *p;
  68         int vn, pn;
  69
  70         v = udev_device_get_sysattr_value(dev, "idVendor");
  71         if (!v)
  72                 return NULL;
  73         p = udev_device_get_sysattr_value(dev, "idProduct");
  74         if (!p)
  75                 return NULL;
  76         vn = strtol(v, NULL, 16);
  77         if (vn <= 0)
  78                 return NULL;
  79         pn = strtol(p, NULL, 16);
  80         if (pn <= 0)
  81                 return NULL;
  82         snprintf(s, size, "usb:v%04Xp%04X*", vn, pn);
  83         return s;
  84 }
  85
  86 static int udev_builtin_hwdb_search(struct udev_device *dev, struct udev_device *srcdev,
  87                                     const char *subsystem, const char *prefix,
  88                                     const char *filter, bool test) {
  89         struct udev_device *d;
  90         char s[16];
  91         bool last = false;
  92         int r = 0;
  93
  94         for (d = srcdev; d && !last; d = udev_device_get_parent(d)) {
  95                 const char *dsubsys;
  96                 const char *modalias = NULL;
  97
  98                 dsubsys = udev_device_get_subsystem(d);
  99                 if (!dsubsys)
 100                         continue;
 101
 102                 /* look only at devices of a specific subsystem */
 103                 if (subsystem && !streq(dsubsys, subsystem))
 104                         continue;
 105
 106                 modalias = udev_device_get_property_value(d, "MODALIAS");
 107
 108                 if (streq(dsubsys, "usb") && streq_ptr(udev_device_get_devtype(d), "usb_device")) {
 109                         /* if the usb_device does not have a modalias, compose one */
 110                         if (!modalias)
 111                                 modalias = modalias_usb(d, s, sizeof(s));
 112
 113                         /* avoid looking at any parent device, they are usually just a USB hub */
 114                         last = true;
 115                 }
 116
 117                 if (!modalias)
 118                         continue;
 119
 120                 r = udev_builtin_hwdb_lookup(dev, prefix, modalias, filter, test);
 121                 if (r > 0)
 122                         break;
 123         }
 124
 125         return r;
 126 }
 127
 128 static int builtin_hwdb(struct udev_device *dev, int argc, char *argv[], bool test) {
 129         static const struct option options[] = {
 130                 { "filter", required_argument, NULL, 'f' },
 131                 { "device", required_argument, NULL, 'd' },
 132                 { "subsystem", required_argument, NULL, 's' },
 133                 { "lookup-prefix", required_argument, NULL, 'p' },
 134                 {}
 135         };
 136         const char *filter = NULL;
 137         const char *device = NULL;
 138         const char *subsystem = NULL;
 139         const char *prefix = NULL;
 140         struct udev_device *srcdev;
 141
 142         if (!hwdb)
 143                 return EXIT_FAILURE;
 144
 145         for (;;) {
 146                 int option;
 147
 148                 option = getopt_long(argc, argv, "f:d:s:p:", options, NULL);
 149                 if (option == -1)
 150                         break;
 151
 152                 switch (option) {
 153                 case 'f':
 154                         filter = optarg;
 155                         break;
 156
 157                 case 'd':
 158                         device = optarg;
 159                         break;
 160
 161                 case 's':
 162                         subsystem = optarg;
 163                         break;
 164
 165                 case 'p':
 166                         prefix = optarg;
 167                         break;
 168                 }
 169         }
 170
 171         /* query a specific key given as argument */
 172         if (argv[optind]) {
 173                 if (udev_builtin_hwdb_lookup(dev, prefix, argv[optind], filter, test) > 0)
 174                         return EXIT_SUCCESS;
 175                 return EXIT_FAILURE;
 176         }
 177
 178         /* read data from another device than the device we will store the data */
 179         if (device) {
 180                 srcdev = udev_device_new_from_device_id(udev_device_get_udev(dev), device);
 181                 if (!srcdev)
 182                         return EXIT_FAILURE;
 183         } else
 184                 srcdev = dev;
 185
 186         if (udev_builtin_hwdb_search(dev, srcdev, subsystem, prefix, filter, test) > 0)
 187                 return EXIT_SUCCESS;
 188         return EXIT_FAILURE;
 189 }
 190
 191 /* called at udev startup and reload */
 192 static int builtin_hwdb_init(struct udev *udev) {
 193         if (hwdb)
 194                 return 0;
 195         hwdb = udev_hwdb_new(udev);
 196         if (!hwdb)
 197                 return -ENOMEM;
 198         return 0;
 199 }
 200
 201 /* called on udev shutdown and reload request */
 202 static void builtin_hwdb_exit(struct udev *udev) {
 203         hwdb = udev_hwdb_unref(hwdb);
 204 }
 205
 206 /* called every couple of seconds during event activity; 'true' if config has changed */
 207 static bool builtin_hwdb_validate(struct udev *udev) {
 208         return udev_hwdb_validate(hwdb);
 209 }
 210
 211 const struct udev_builtin udev_builtin_hwdb = {
 212         .name = "hwdb",
 213         .cmd = builtin_hwdb,
 214         .init = builtin_hwdb_init,
 215         .exit = builtin_hwdb_exit,
 216         .validate = builtin_hwdb_validate,
 217         .help = "hardware database",
 218 };