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 <fnmatch.h>
  21 #include <getopt.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24
  25 #include "sd-hwdb.h"
  26
  27 #include "hwdb-util.h"
  28 #include "string-util.h"
  29 #include "udev-util.h"
  30 #include "udev.h"
  31
  32 static sd_hwdb *hwdb;
  33
  34 int udev_builtin_hwdb_lookup(struct udev_device *dev,
  35                              const char *prefix, const char *modalias,
  36                              const char *filter, bool test) {
  37         _cleanup_free_ char *lookup = NULL;
  38         const char *key, *value;
  39         int n = 0;
  40
  41         if (!hwdb)
  42                 return -ENOENT;
  43
  44         if (prefix) {
  45                 lookup = strjoin(prefix, modalias, NULL);
  46                 if (!lookup)
  47                         return -ENOMEM;
  48                 modalias = lookup;
  49         }
  50
  51         SD_HWDB_FOREACH_PROPERTY(hwdb, modalias, key, value) {
  52                 if (filter && fnmatch(filter, key, FNM_NOESCAPE) != 0)
  53                         continue;
  54
  55                 if (udev_builtin_add_property(dev, test, key, value) < 0)
  56                         return -ENOMEM;
  57                 n++;
  58         }
  59         return n;
  60 }
  61
  62 static const char *modalias_usb(struct udev_device *dev, char *s, size_t size) {
  63         const char *v, *p;
  64         int vn, pn;
  65
  66         v = udev_device_get_sysattr_value(dev, "idVendor");
  67         if (!v)
  68                 return NULL;
  69         p = udev_device_get_sysattr_value(dev, "idProduct");
  70         if (!p)
  71                 return NULL;
  72         vn = strtol(v, NULL, 16);
  73         if (vn <= 0)
  74                 return NULL;
  75         pn = strtol(p, NULL, 16);
  76         if (pn <= 0)
  77                 return NULL;
  78         snprintf(s, size, "usb:v%04Xp%04X*", vn, pn);
  79         return s;
  80 }
  81
  82 static int udev_builtin_hwdb_search(struct udev_device *dev, struct udev_device *srcdev,
  83                                     const char *subsystem, const char *prefix,
  84                                     const char *filter, bool test) {
  85         struct udev_device *d;
  86         char s[16];
  87         bool last = false;
  88         int r = 0;
  89
  90         assert(dev);
  91
  92         if (!srcdev)
  93                 srcdev = dev;
  94
  95         for (d = srcdev; d && !last; d = udev_device_get_parent(d)) {
  96                 const char *dsubsys;
  97                 const char *modalias = NULL;
  98
  99                 dsubsys = udev_device_get_subsystem(d);
 100                 if (!dsubsys)
 101                         continue;
 102
 103                 /* look only at devices of a specific subsystem */
 104                 if (subsystem && !streq(dsubsys, subsystem))
 105                         continue;
 106
 107                 modalias = udev_device_get_property_value(d, "MODALIAS");
 108
 109                 if (streq(dsubsys, "usb") && streq_ptr(udev_device_get_devtype(d), "usb_device")) {
 110                         /* if the usb_device does not have a modalias, compose one */
 111                         if (!modalias)
 112                                 modalias = modalias_usb(d, s, sizeof(s));
 113
 114                         /* avoid looking at any parent device, they are usually just a USB hub */
 115                         last = true;
 116                 }
 117
 118                 if (!modalias)
 119                         continue;
 120
 121                 r = udev_builtin_hwdb_lookup(dev, prefix, modalias, filter, test);
 122                 if (r > 0)
 123                         break;
 124         }
 125
 126         return r;
 127 }
 128
 129 static int builtin_hwdb(struct udev_device *dev, int argc, char *argv[], bool test) {
 130         static const struct option options[] = {
 131                 { "filter", required_argument, NULL, 'f' },
 132                 { "device", required_argument, NULL, 'd' },
 133                 { "subsystem", required_argument, NULL, 's' },
 134                 { "lookup-prefix", required_argument, NULL, 'p' },
 135                 {}
 136         };
 137         const char *filter = NULL;
 138         const char *device = NULL;
 139         const char *subsystem = NULL;
 140         const char *prefix = NULL;
 141         _cleanup_udev_device_unref_ struct udev_device *srcdev = NULL;
 142
 143         if (!hwdb)
 144                 return EXIT_FAILURE;
 145
 146         for (;;) {
 147                 int option;
 148
 149                 option = getopt_long(argc, argv, "f:d:s:p:", options, NULL);
 150                 if (option == -1)
 151                         break;
 152
 153                 switch (option) {
 154                 case 'f':
 155                         filter = optarg;
 156                         break;
 157
 158                 case 'd':
 159                         device = optarg;
 160                         break;
 161
 162                 case 's':
 163                         subsystem = optarg;
 164                         break;
 165
 166                 case 'p':
 167                         prefix = optarg;
 168                         break;
 169                 }
 170         }
 171
 172         /* query a specific key given as argument */
 173         if (argv[optind]) {
 174                 if (udev_builtin_hwdb_lookup(dev, prefix, argv[optind], filter, test) > 0)
 175                         return EXIT_SUCCESS;
 176                 return EXIT_FAILURE;
 177         }
 178
 179         /* read data from another device than the device we will store the data */
 180         if (device) {
 181                 srcdev = udev_device_new_from_device_id(udev_device_get_udev(dev), device);
 182                 if (!srcdev)
 183                         return EXIT_FAILURE;
 184         }
 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         int r;
 194
 195         if (hwdb)
 196                 return 0;
 197
 198         r = sd_hwdb_new(&hwdb);
 199         if (r < 0)
 200                 return r;
 201
 202         return 0;
 203 }
 204
 205 /* called on udev shutdown and reload request */
 206 static void builtin_hwdb_exit(struct udev *udev) {
 207         hwdb = sd_hwdb_unref(hwdb);
 208 }
 209
 210 /* called every couple of seconds during event activity; 'true' if config has changed */
 211 static bool builtin_hwdb_validate(struct udev *udev) {
 212         return hwdb_validate(hwdb);
 213 }
 214
 215 const struct udev_builtin udev_builtin_hwdb = {
 216         .name = "hwdb",
 217         .cmd = builtin_hwdb,
 218         .init = builtin_hwdb_init,
 219         .exit = builtin_hwdb_exit,
 220         .validate = builtin_hwdb_validate,
 221         .help = "Hardware database",
 222 };