libudev/libudev-enumerate.c

   1 /*
   2  * libudev - interface to udev device information
   3  *
   4  * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <stddef.h>
  15 #include <unistd.h>
  16 #include <errno.h>
  17 #include <string.h>
  18 #include <dirent.h>
  19 #include <fnmatch.h>
  20 #include <sys/stat.h>
  21
  22 #include "libudev.h"
  23 #include "libudev-private.h"
  24
  25 static int devices_sort(struct udev_enumerate *udev_enumerate);
  26
  27 struct udev_enumerate {
  28         struct udev *udev;
  29         int refcount;
  30         struct udev_list_node sysattr_match_list;
  31         struct udev_list_node sysattr_nomatch_list;
  32         struct udev_list_node subsystem_match_list;
  33         struct udev_list_node subsystem_nomatch_list;
  34         struct udev_list_node properties_match_list;
  35         struct udev_list_node devices_list;
  36         int devices_sorted;
  37 };
  38
  39 /**
  40  * udev_enumerate_new:
  41  * @udev: udev library context
  42  *
  43  * Returns: an enumeration context
  44  **/
  45 struct udev_enumerate *udev_enumerate_new(struct udev *udev)
  46 {
  47         struct udev_enumerate *udev_enumerate;
  48
  49         udev_enumerate = calloc(1, sizeof(struct udev_enumerate));
  50         if (udev_enumerate == NULL)
  51                 return NULL;
  52         udev_enumerate->refcount = 1;
  53         udev_enumerate->udev = udev;
  54         udev_list_init(&udev_enumerate->devices_list);
  55         udev_list_init(&udev_enumerate->sysattr_match_list);
  56         udev_list_init(&udev_enumerate->sysattr_nomatch_list);
  57         udev_list_init(&udev_enumerate->subsystem_match_list);
  58         udev_list_init(&udev_enumerate->subsystem_nomatch_list);
  59         udev_list_init(&udev_enumerate->properties_match_list);
  60         return udev_enumerate;
  61 }
  62
  63 struct udev_enumerate *udev_enumerate_ref(struct udev_enumerate *udev_enumerate)
  64 {
  65         if (udev_enumerate == NULL)
  66                 return NULL;
  67         udev_enumerate->refcount++;
  68         return udev_enumerate;
  69 }
  70
  71 void udev_enumerate_unref(struct udev_enumerate *udev_enumerate)
  72 {
  73         if (udev_enumerate == NULL)
  74                 return;
  75         udev_enumerate->refcount--;
  76         if (udev_enumerate->refcount > 0)
  77                 return;
  78         udev_list_cleanup_entries(udev_enumerate->udev, &udev_enumerate->devices_list);
  79         udev_list_cleanup_entries(udev_enumerate->udev, &udev_enumerate->sysattr_match_list);
  80         udev_list_cleanup_entries(udev_enumerate->udev, &udev_enumerate->sysattr_nomatch_list);
  81         udev_list_cleanup_entries(udev_enumerate->udev, &udev_enumerate->subsystem_match_list);
  82         udev_list_cleanup_entries(udev_enumerate->udev, &udev_enumerate->subsystem_nomatch_list);
  83         udev_list_cleanup_entries(udev_enumerate->udev, &udev_enumerate->properties_match_list);
  84         free(udev_enumerate);
  85 }
  86
  87 struct udev *udev_enumerate_get_udev(struct udev_enumerate *udev_enumerate)
  88 {
  89         if (udev_enumerate == NULL)
  90                 return NULL;
  91         return udev_enumerate->udev;
  92 }
  93
  94 struct udev_list_entry *udev_enumerate_get_list_entry(struct udev_enumerate *udev_enumerate)
  95 {
  96         if (udev_enumerate == NULL)
  97                 return NULL;
  98         if (!udev_enumerate->devices_sorted)
  99                 devices_sort(udev_enumerate);
 100         return udev_list_get_entry(&udev_enumerate->devices_list);
 101 }
 102
 103 int udev_enumerate_add_match_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
 104 {
 105         if (udev_enumerate == NULL)
 106                 return -EINVAL;
 107         if (subsystem == NULL)
 108                 return 0;
 109         if (udev_list_entry_add(udev_enumerate_get_udev(udev_enumerate),
 110                                 &udev_enumerate->subsystem_match_list, subsystem, NULL, 1, 0) == NULL)
 111                 return -ENOMEM;
 112         return 0;
 113 }
 114
 115 int udev_enumerate_add_nomatch_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
 116 {
 117         if (udev_enumerate == NULL)
 118                 return -EINVAL;
 119         if (subsystem == NULL)
 120                 return 0;
 121         if (udev_list_entry_add(udev_enumerate_get_udev(udev_enumerate),
 122                                 &udev_enumerate->subsystem_nomatch_list, subsystem, NULL, 1, 0) == NULL)
 123                 return -ENOMEM;
 124         return 0;
 125 }
 126
 127 int udev_enumerate_add_match_sysattr(struct udev_enumerate *udev_enumerate, const char *sysattr, const char *value)
 128 {
 129         if (udev_enumerate == NULL)
 130                 return -EINVAL;
 131         if (sysattr == NULL)
 132                 return 0;
 133         if (udev_list_entry_add(udev_enumerate_get_udev(udev_enumerate),
 134                            &udev_enumerate->sysattr_match_list, sysattr, value, 0, 0) == NULL)
 135                 return -ENOMEM;
 136         return 0;
 137 }
 138
 139 int udev_enumerate_add_nomatch_sysattr(struct udev_enumerate *udev_enumerate, const char *sysattr, const char *value)
 140 {
 141         if (udev_enumerate == NULL)
 142                 return -EINVAL;
 143         if (sysattr == NULL)
 144                 return 0;
 145         if (udev_list_entry_add(udev_enumerate_get_udev(udev_enumerate),
 146                            &udev_enumerate->sysattr_nomatch_list, sysattr, value, 0, 0) == NULL)
 147                 return -ENOMEM;
 148         return 0;
 149 }
 150
 151 static int match_sysattr_value(struct udev *udev, const char *syspath, const char *sysattr, const char *match_val)
 152 {
 153         struct udev_device *device;
 154         const char *val = NULL;
 155         int match = 0;
 156
 157         device = udev_device_new_from_syspath(udev, syspath);
 158         if (device == NULL)
 159                 return -EINVAL;
 160         val = udev_device_get_sysattr_value(device, sysattr);
 161         if (val == NULL)
 162                 goto exit;
 163         if (match_val == NULL) {
 164                 match = 1;
 165                 goto exit;
 166         }
 167         if (fnmatch(match_val, val, 0) == 0) {
 168                 match = 1;
 169                 goto exit;
 170         }
 171 exit:
 172         udev_device_unref(device);
 173         return match;
 174 }
 175
 176 int udev_enumerate_add_match_property(struct udev_enumerate *udev_enumerate, const char *property, const char *value)
 177 {
 178         if (udev_enumerate == NULL)
 179                 return -EINVAL;
 180         if (property == NULL)
 181                 return 0;
 182         if (udev_list_entry_add(udev_enumerate_get_udev(udev_enumerate),
 183                                 &udev_enumerate->properties_match_list, property, value, 0, 0) == NULL)
 184                 return -ENOMEM;
 185         return 0;
 186 }
 187
 188 static int match_sysattr(struct udev_enumerate *udev_enumerate, const char *syspath)
 189 {
 190         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 191         struct udev_list_entry *list_entry;
 192
 193         /* skip list */
 194         udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->sysattr_nomatch_list)) {
 195                 if (match_sysattr_value(udev, syspath,
 196                                      udev_list_entry_get_name(list_entry),
 197                                      udev_list_entry_get_value(list_entry)))
 198                         return 0;
 199         }
 200         /* include list */
 201         if (udev_list_get_entry(&udev_enumerate->sysattr_match_list) != NULL) {
 202                 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->sysattr_match_list)) {
 203                         /* anything that does not match, will make it FALSE */
 204                         if (!match_sysattr_value(udev, syspath,
 205                                               udev_list_entry_get_name(list_entry),
 206                                               udev_list_entry_get_value(list_entry)))
 207                                 return 0;
 208                 }
 209                 return 1;
 210         }
 211         return 1;
 212 }
 213
 214 static int match_property(struct udev_enumerate *udev_enumerate, const char *syspath)
 215 {
 216         struct udev_device *dev;
 217         struct udev_list_entry *list_entry;
 218         int match = 0;
 219
 220         /* no match always matches */
 221         if (udev_list_get_entry(&udev_enumerate->properties_match_list) == NULL)
 222                 return 1;
 223
 224         /* no device does not match */
 225         dev = udev_device_new_from_syspath(udev_enumerate->udev, syspath);
 226         if (dev == NULL)
 227                 return 0;
 228
 229         /* loop over matches */
 230         udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->properties_match_list)) {
 231                 const char *match_key = udev_list_entry_get_name(list_entry);
 232                 const char *match_value = udev_list_entry_get_value(list_entry);
 233                 struct udev_list_entry *property_entry;
 234
 235                 /* loop over device properties */
 236                 udev_list_entry_foreach(property_entry, udev_device_get_properties_list_entry(dev)) {
 237                         const char *dev_key = udev_list_entry_get_name(property_entry);
 238                         const char *dev_value = udev_list_entry_get_value(property_entry);
 239
 240                         if (fnmatch(match_key, dev_key, 0) != 0)
 241                                 continue;
 242                         if (match_value == NULL && dev_value == NULL) {
 243                                 match = 1;
 244                                 goto out;
 245                         }
 246                         if (match_value == NULL || dev_value == NULL)
 247                                 continue;
 248                         if (fnmatch(match_value, dev_value, 0) == 0) {
 249                                 match = 1;
 250                                 goto out;
 251                         }
 252                 }
 253         }
 254 out:
 255         udev_device_unref(dev);
 256         return match;
 257 }
 258
 259 static int scan_dir_and_add_devices(struct udev_enumerate *udev_enumerate,
 260                                     const char *basedir, const char *subdir1, const char *subdir2)
 261 {
 262         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 263         char path[UTIL_PATH_SIZE];
 264         size_t l;
 265         char *s;
 266         DIR *dir;
 267         struct dirent *dent;
 268
 269         s = path;
 270         l = util_strpcpyl(&s, sizeof(path), udev_get_sys_path(udev), "/", basedir, NULL);
 271         if (subdir1 != NULL)
 272                 l = util_strpcpyl(&s, l, "/", subdir1, NULL);
 273         if (subdir2 != NULL)
 274                 l = util_strpcpyl(&s, l, "/", subdir2, NULL);
 275         dir = opendir(path);
 276         if (dir == NULL)
 277                 return -1;
 278         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 279                 char syspath[UTIL_PATH_SIZE];
 280                 char filename[UTIL_PATH_SIZE];
 281                 struct stat statbuf;
 282
 283                 if (dent->d_name[0] == '.')
 284                         continue;
 285                 util_strscpyl(syspath, sizeof(syspath), path, "/", dent->d_name, NULL);
 286                 if (lstat(syspath, &statbuf) != 0)
 287                         continue;
 288                 if (S_ISREG(statbuf.st_mode))
 289                         continue;
 290                 if (S_ISLNK(statbuf.st_mode))
 291                         util_resolve_sys_link(udev, syspath, sizeof(syspath));
 292
 293                 util_strscpyl(filename, sizeof(filename), syspath, "/uevent", NULL);
 294                 if (stat(filename, &statbuf) != 0)
 295                         continue;
 296                 if (!match_sysattr(udev_enumerate, syspath))
 297                         continue;
 298                 if (!match_property(udev_enumerate, syspath))
 299                         continue;
 300                 udev_list_entry_add(udev, &udev_enumerate->devices_list, syspath, NULL, 1, 1);
 301         }
 302         closedir(dir);
 303         return 0;
 304 }
 305
 306 static int match_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
 307 {
 308         struct udev_list_entry *list_entry;
 309
 310         udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_nomatch_list)) {
 311                 if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
 312                         return 0;
 313         }
 314         if (udev_list_get_entry(&udev_enumerate->subsystem_match_list) != NULL) {
 315                 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_match_list)) {
 316                         if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
 317                                 return 1;
 318                 }
 319                 return 0;
 320         }
 321         return 1;
 322 }
 323
 324 static int scan_dir(struct udev_enumerate *udev_enumerate, const char *basedir, const char *subdir, const char *subsystem)
 325 {
 326         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 327
 328         char path[UTIL_PATH_SIZE];
 329         DIR *dir;
 330         struct dirent *dent;
 331
 332         util_strscpyl(path, sizeof(path), udev_get_sys_path(udev), "/", basedir, NULL);
 333         dir = opendir(path);
 334         if (dir == NULL)
 335                 return -1;
 336         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 337                 if (dent->d_name[0] == '.')
 338                         continue;
 339                 if (!match_subsystem(udev_enumerate, subsystem != NULL ? subsystem : dent->d_name))
 340                         continue;
 341                 scan_dir_and_add_devices(udev_enumerate, basedir, dent->d_name, subdir);
 342         }
 343         closedir(dir);
 344         return 0;
 345 }
 346
 347 static int devices_delay(struct udev *udev, const char *syspath)
 348 {
 349         static const char *delay_device_list[] = {
 350                 "/block/md",
 351                 "/block/dm-",
 352                 NULL
 353         };
 354         size_t len;
 355         int i;
 356
 357         len = strlen(udev_get_sys_path(udev));
 358         for (i = 0; delay_device_list[i] != NULL; i++) {
 359                 if (strstr(&syspath[len], delay_device_list[i]) != NULL) {
 360                         dbg(udev, "delaying: %s\n", syspath);
 361                         return 1;
 362                 }
 363         }
 364         return 0;
 365 }
 366
 367 /* sort delayed devices to the end of the list */
 368 static int devices_sort(struct udev_enumerate *udev_enumerate)
 369 {
 370         struct udev_list_entry *entry_loop;
 371         struct udev_list_entry *entry_tmp;
 372         struct udev_list_node devices_list;
 373
 374         udev_list_init(&devices_list);
 375         /* move delayed to delay list */
 376         udev_list_entry_foreach_safe(entry_loop, entry_tmp, udev_list_get_entry(&udev_enumerate->devices_list)) {
 377                 if (devices_delay(udev_enumerate->udev, udev_list_entry_get_name(entry_loop))) {
 378                         udev_list_entry_remove(entry_loop);
 379                         udev_list_entry_append(entry_loop, &devices_list);
 380                 }
 381         }
 382         /* move delayed back to end of list */
 383         udev_list_entry_foreach_safe(entry_loop, entry_tmp, udev_list_get_entry(&devices_list)) {
 384                 udev_list_entry_remove(entry_loop);
 385                 udev_list_entry_append(entry_loop, &udev_enumerate->devices_list);
 386         }
 387         udev_enumerate->devices_sorted = 1;
 388         return 0;
 389 }
 390
 391 int udev_enumerate_add_syspath(struct udev_enumerate *udev_enumerate, const char *syspath)
 392 {
 393         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 394         struct udev_device *udev_device;
 395
 396         if (udev_enumerate == NULL)
 397                 return -EINVAL;
 398         if (syspath == NULL)
 399                 return 0;
 400         /* resolve to real syspath */
 401         udev_device = udev_device_new_from_syspath(udev_enumerate->udev, syspath);
 402         if (udev_device == NULL)
 403                 return -EINVAL;
 404         udev_list_entry_add(udev, &udev_enumerate->devices_list,
 405                             udev_device_get_syspath(udev_device), NULL, 1, 1);
 406         udev_device_unref(udev_device);
 407         return 0;
 408 }
 409
 410 /**
 411  * udev_enumerate_scan_devices:
 412  * @udev_enumerate: udev enumeration context
 413  *
 414  * Returns: a negative value on error.
 415  **/
 416 int udev_enumerate_scan_devices(struct udev_enumerate *udev_enumerate)
 417 {
 418         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 419         char base[UTIL_PATH_SIZE];
 420         struct stat statbuf;
 421
 422         if (udev_enumerate == NULL)
 423                 return -EINVAL;
 424         util_strscpyl(base, sizeof(base), udev_get_sys_path(udev), "/subsystem", NULL);
 425         if (stat(base, &statbuf) == 0) {
 426                 /* we have /subsystem/, forget all the old stuff */
 427                 dbg(udev, "searching '/subsystem/*/devices/*' dir\n");
 428                 scan_dir(udev_enumerate, "subsystem", "devices", NULL);
 429         } else {
 430                 dbg(udev, "searching '/bus/*/devices/*' dir\n");
 431                 scan_dir(udev_enumerate, "bus", "devices", NULL);
 432                 dbg(udev, "searching '/class/*' dir\n");
 433                 scan_dir(udev_enumerate, "class", NULL, NULL);
 434                 /* if block isn't a class, scan /block/ */
 435                 util_strscpyl(base, sizeof(base), udev_get_sys_path(udev), "/class/block", NULL);
 436                 if (stat(base, &statbuf) != 0) {
 437                         if (match_subsystem(udev_enumerate, "block")) {
 438                                 dbg(udev, "searching '/block/*' dir\n");
 439                                 /* scan disks */
 440                                 scan_dir_and_add_devices(udev_enumerate, "block", NULL, NULL);
 441                                 /* scan partitions */
 442                                 dbg(udev, "searching '/block/*/*' dir\n");
 443                                 scan_dir(udev_enumerate, "block", NULL, "block");
 444                         }
 445                 }
 446         }
 447         return 0;
 448 }
 449
 450 /**
 451  * udev_enumerate_scan_subsystems:
 452  * @udev_enumerate: udev enumeration context
 453  *
 454  * Returns: a negative value on error.
 455  **/
 456 int udev_enumerate_scan_subsystems(struct udev_enumerate *udev_enumerate)
 457 {
 458         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 459         char base[UTIL_PATH_SIZE];
 460         struct stat statbuf;
 461         const char *subsysdir;
 462
 463         if (udev_enumerate == NULL)
 464                 return -EINVAL;
 465         util_strscpyl(base, sizeof(base), udev_get_sys_path(udev), "/subsystem", NULL);
 466         if (stat(base, &statbuf) == 0)
 467                 subsysdir = "subsystem";
 468         else
 469                 subsysdir = "bus";
 470         if (match_subsystem(udev_enumerate, "subsystem")) {
 471                 dbg(udev, "searching '%s/*' dir\n", subsysdir);
 472                 scan_dir_and_add_devices(udev_enumerate, subsysdir, NULL, NULL);
 473         }
 474         if (match_subsystem(udev_enumerate, "drivers")) {
 475                 dbg(udev, "searching '%s/*/drivers/*' dir\n", subsysdir);
 476                 scan_dir(udev_enumerate, subsysdir, "drivers", "drivers");
 477         }
 478         return 0;
 479 }