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