src/udev/udev-builtin-hwdb.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4 #include <fnmatch.h>
   5 #include <getopt.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8
   9 #include "sd-hwdb.h"
  10
  11 #include "alloc-util.h"
  12 #include "device-util.h"
  13 #include "hwdb-util.h"
  14 #include "parse-util.h"
  15 #include "string-util.h"
  16 #include "udev-builtin.h"
  17
  18 static sd_hwdb *hwdb;
  19
  20 int udev_builtin_hwdb_lookup(sd_device *dev,
  21                              const char *prefix, const char *modalias,
  22                              const char *filter, bool test) {
  23         _cleanup_free_ char *lookup = NULL;
  24         const char *key, *value;
  25         int n = 0, r;
  26
  27         if (!hwdb)
  28                 return -ENOENT;
  29
  30         if (prefix) {
  31                 lookup = strjoin(prefix, modalias);
  32                 if (!lookup)
  33                         return -ENOMEM;
  34                 modalias = lookup;
  35         }
  36
  37         SD_HWDB_FOREACH_PROPERTY(hwdb, modalias, key, value) {
  38                 if (filter && fnmatch(filter, key, FNM_NOESCAPE) != 0)
  39                         continue;
  40
  41                 r = udev_builtin_add_property(dev, test, key, value);
  42                 if (r < 0)
  43                         return r;
  44                 n++;
  45         }
  46         return n;
  47 }
  48
  49 static const char *modalias_usb(sd_device *dev, char *s, size_t size) {
  50         const char *v, *p;
  51         uint16_t vn, pn;
  52
  53         if (sd_device_get_sysattr_value(dev, "idVendor", &v) < 0)
  54                 return NULL;
  55         if (sd_device_get_sysattr_value(dev, "idProduct", &p) < 0)
  56                 return NULL;
  57         if (safe_atoux16(v, &vn) < 0)
  58                 return NULL;
  59         if (safe_atoux16(p, &pn) < 0)
  60                 return NULL;
  61         snprintf(s, size, "usb:v%04Xp%04X*", vn, pn);
  62         return s;
  63 }
  64
  65 static int udev_builtin_hwdb_search(sd_device *dev, sd_device *srcdev,
  66                                     const char *subsystem, const char *prefix,
  67                                     const char *filter, bool test) {
  68         sd_device *d;
  69         char s[16];
  70         bool last = false;
  71         int r = 0;
  72
  73         assert(dev);
  74
  75         if (!srcdev)
  76                 srcdev = dev;
  77
  78         for (d = srcdev; d; ) {
  79                 const char *dsubsys, *devtype, *modalias = NULL;
  80
  81                 if (sd_device_get_subsystem(d, &dsubsys) < 0)
  82                         goto next;
  83
  84                 /* look only at devices of a specific subsystem */
  85                 if (subsystem && !streq(dsubsys, subsystem))
  86                         goto next;
  87
  88                 (void) sd_device_get_property_value(d, "MODALIAS", &modalias);
  89
  90                 if (streq(dsubsys, "usb") &&
  91                     sd_device_get_devtype(d, &devtype) >= 0 &&
  92                     streq(devtype, "usb_device")) {
  93                         /* if the usb_device does not have a modalias, compose one */
  94                         if (!modalias)
  95                                 modalias = modalias_usb(d, s, sizeof(s));
  96
  97                         /* avoid looking at any parent device, they are usually just a USB hub */
  98                         last = true;
  99                 }
 100
 101                 if (!modalias)
 102                         goto next;
 103
 104                 r = udev_builtin_hwdb_lookup(dev, prefix, modalias, filter, test);
 105                 if (r > 0)
 106                         break;
 107
 108                 if (last)
 109                         break;
 110 next:
 111                 if (sd_device_get_parent(d, &d) < 0)
 112                         break;
 113         }
 114
 115         return r;
 116 }
 117
 118 static int builtin_hwdb(sd_device *dev, int argc, char *argv[], bool test) {
 119         static const struct option options[] = {
 120                 { "filter", required_argument, NULL, 'f' },
 121                 { "device", required_argument, NULL, 'd' },
 122                 { "subsystem", required_argument, NULL, 's' },
 123                 { "lookup-prefix", required_argument, NULL, 'p' },
 124                 {}
 125         };
 126         const char *filter = NULL;
 127         const char *device = NULL;
 128         const char *subsystem = NULL;
 129         const char *prefix = NULL;
 130         _cleanup_(sd_device_unrefp) sd_device *srcdev = NULL;
 131         int r;
 132
 133         if (!hwdb)
 134                 return -EINVAL;
 135
 136         for (;;) {
 137                 int option;
 138
 139                 option = getopt_long(argc, argv, "f:d:s:p:", options, NULL);
 140                 if (option == -1)
 141                         break;
 142
 143                 switch (option) {
 144                 case 'f':
 145                         filter = optarg;
 146                         break;
 147
 148                 case 'd':
 149                         device = optarg;
 150                         break;
 151
 152                 case 's':
 153                         subsystem = optarg;
 154                         break;
 155
 156                 case 'p':
 157                         prefix = optarg;
 158                         break;
 159                 }
 160         }
 161
 162         /* query a specific key given as argument */
 163         if (argv[optind]) {
 164                 r = udev_builtin_hwdb_lookup(dev, prefix, argv[optind], filter, test);
 165                 if (r < 0)
 166                         return log_device_debug_errno(dev, r, "Failed to lookup hwdb: %m");
 167                 if (r == 0)
 168                         return log_device_debug_errno(dev, SYNTHETIC_ERRNO(ENODATA), "No entry found from hwdb.");
 169                 return r;
 170         }
 171
 172         /* read data from another device than the device we will store the data */
 173         if (device) {
 174                 r = sd_device_new_from_device_id(&srcdev, device);
 175                 if (r < 0)
 176                         return log_device_debug_errno(dev, r, "Failed to create sd_device object '%s': %m", device);
 177         }
 178
 179         r = udev_builtin_hwdb_search(dev, srcdev, subsystem, prefix, filter, test);
 180         if (r < 0)
 181                 return log_device_debug_errno(dev, r, "Failed to lookup hwdb: %m");
 182         if (r == 0)
 183                 return log_device_debug_errno(dev, SYNTHETIC_ERRNO(ENODATA), "No entry found from hwdb.");
 184         return r;
 185 }
 186
 187 /* called at udev startup and reload */
 188 static int builtin_hwdb_init(void) {
 189         int r;
 190
 191         if (hwdb)
 192                 return 0;
 193
 194         r = sd_hwdb_new(&hwdb);
 195         if (r < 0)
 196                 return r;
 197
 198         return 0;
 199 }
 200
 201 /* called on udev shutdown and reload request */
 202 static void builtin_hwdb_exit(void) {
 203         hwdb = sd_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(void) {
 208         return 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 };