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 "alloc-util.h"
  28 #include "hwdb-util.h"
  29 #include "string-util.h"
  30 #include "udev-util.h"
  31 #include "udev.h"
  32
  33 static sd_hwdb *hwdb;
  34
  35 int udev_builtin_hwdb_lookup(struct udev_device *dev,
  36                              const char *prefix, const char *modalias,
  37                              const char *filter, bool test) {
  38         _cleanup_free_ char *lookup = NULL;
  39         const char *key, *value;
  40         int n = 0;
  41
  42         if (!hwdb)
  43                 return -ENOENT;
  44
  45         if (prefix) {
  46                 lookup = strjoin(prefix, modalias, NULL);
  47                 if (!lookup)
  48                         return -ENOMEM;
  49                 modalias = lookup;
  50         }
  51
  52         SD_HWDB_FOREACH_PROPERTY(hwdb, modalias, key, value) {
  53                 if (filter && fnmatch(filter, key, FNM_NOESCAPE) != 0)
  54                         continue;
  55
  56                 if (udev_builtin_add_property(dev, test, key, value) < 0)
  57                         return -ENOMEM;
  58                 n++;
  59         }
  60         return n;
  61 }
  62
  63 static const char *modalias_usb(struct udev_device *dev, char *s, size_t size) {
  64         const char *v, *p;
  65         int vn, pn;
  66
  67         v = udev_device_get_sysattr_value(dev, "idVendor");
  68         if (!v)
  69                 return NULL;
  70         p = udev_device_get_sysattr_value(dev, "idProduct");
  71         if (!p)
  72                 return NULL;
  73         vn = strtol(v, NULL, 16);
  74         if (vn <= 0)
  75                 return NULL;
  76         pn = strtol(p, NULL, 16);
  77         if (pn <= 0)
  78                 return NULL;
  79         snprintf(s, size, "usb:v%04Xp%04X*", vn, pn);
  80         return s;
  81 }
  82
  83 static int udev_builtin_hwdb_search(struct udev_device *dev, struct udev_device *srcdev,
  84                                     const char *subsystem, const char *prefix,
  85                                     const char *filter, bool test) {
  86         struct udev_device *d;
  87         char s[16];
  88         bool last = false;
  89         int r = 0;
  90
  91         assert(dev);
  92
  93         if (!srcdev)
  94                 srcdev = dev;
  95
  96         for (d = srcdev; d && !last; d = udev_device_get_parent(d)) {
  97                 const char *dsubsys;
  98                 const char *modalias = NULL;
  99
 100                 dsubsys = udev_device_get_subsystem(d);
 101                 if (!dsubsys)
 102                         continue;
 103
 104                 /* look only at devices of a specific subsystem */
 105                 if (subsystem && !streq(dsubsys, subsystem))
 106                         continue;
 107
 108                 modalias = udev_device_get_property_value(d, "MODALIAS");
 109
 110                 if (streq(dsubsys, "usb") && streq_ptr(udev_device_get_devtype(d), "usb_device")) {
 111                         /* if the usb_device does not have a modalias, compose one */
 112                         if (!modalias)
 113                                 modalias = modalias_usb(d, s, sizeof(s));
 114
 115                         /* avoid looking at any parent device, they are usually just a USB hub */
 116                         last = true;
 117                 }
 118
 119                 if (!modalias)
 120                         continue;
 121
 122                 r = udev_builtin_hwdb_lookup(dev, prefix, modalias, filter, test);
 123                 if (r > 0)
 124                         break;
 125         }
 126
 127         return r;
 128 }
 129
 130 static int builtin_hwdb(struct udev_device *dev, int argc, char *argv[], bool test) {
 131         static const struct option options[] = {
 132                 { "filter", required_argument, NULL, 'f' },
 133                 { "device", required_argument, NULL, 'd' },
 134                 { "subsystem", required_argument, NULL, 's' },
 135                 { "lookup-prefix", required_argument, NULL, 'p' },
 136                 {}
 137         };
 138         const char *filter = NULL;
 139         const char *device = NULL;
 140         const char *subsystem = NULL;
 141         const char *prefix = NULL;
 142         _cleanup_udev_device_unref_ struct udev_device *srcdev = NULL;
 143
 144         if (!hwdb)
 145                 return EXIT_FAILURE;
 146
 147         for (;;) {
 148                 int option;
 149
 150                 option = getopt_long(argc, argv, "f:d:s:p:", options, NULL);
 151                 if (option == -1)
 152                         break;
 153
 154                 switch (option) {
 155                 case 'f':
 156                         filter = optarg;
 157                         break;
 158
 159                 case 'd':
 160                         device = optarg;
 161                         break;
 162
 163                 case 's':
 164                         subsystem = optarg;
 165                         break;
 166
 167                 case 'p':
 168                         prefix = optarg;
 169                         break;
 170                 }
 171         }
 172
 173         /* query a specific key given as argument */
 174         if (argv[optind]) {
 175                 if (udev_builtin_hwdb_lookup(dev, prefix, argv[optind], filter, test) > 0)
 176                         return EXIT_SUCCESS;
 177                 return EXIT_FAILURE;
 178         }
 179
 180         /* read data from another device than the device we will store the data */
 181         if (device) {
 182                 srcdev = udev_device_new_from_device_id(udev_device_get_udev(dev), device);
 183                 if (!srcdev)
 184                         return EXIT_FAILURE;
 185         }
 186
 187         if (udev_builtin_hwdb_search(dev, srcdev, subsystem, prefix, filter, test) > 0)
 188                 return EXIT_SUCCESS;
 189         return EXIT_FAILURE;
 190 }
 191
 192 /* called at udev startup and reload */
 193 static int builtin_hwdb_init(struct udev *udev) {
 194         int r;
 195
 196         if (hwdb)
 197                 return 0;
 198
 199         r = sd_hwdb_new(&hwdb);
 200         if (r < 0)
 201                 return r;
 202
 203         return 0;
 204 }
 205
 206 /* called on udev shutdown and reload request */
 207 static void builtin_hwdb_exit(struct udev *udev) {
 208         hwdb = sd_hwdb_unref(hwdb);
 209 }
 210
 211 /* called every couple of seconds during event activity; 'true' if config has changed */
 212 static bool builtin_hwdb_validate(struct udev *udev) {
 213         return hwdb_validate(hwdb);
 214 }
 215
 216 const struct udev_builtin udev_builtin_hwdb = {
 217         .name = "hwdb",
 218         .cmd = builtin_hwdb,
 219         .init = builtin_hwdb_init,
 220         .exit = builtin_hwdb_exit,
 221         .validate = builtin_hwdb_validate,
 222         .help = "Hardware database",
 223 };