udev/lib/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, 1, 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, 1, 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, 1, 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                 struct udev_list_entry *property_entry;
 232
 233                 /* loop over device properties */
 234                 udev_list_entry_foreach(property_entry, udev_device_get_properties_list_entry(dev)) {
 235                         if (fnmatch(udev_list_entry_get_name(list_entry), udev_list_entry_get_name(property_entry), 0) == 0) {
 236                                 const char *match_value;
 237                                 const char *dev_value;
 238
 239                                 match_value = udev_list_entry_get_value(list_entry);
 240                                 dev_value = udev_list_entry_get_value(property_entry);
 241                                 if (match_value == NULL && dev_value == NULL) {
 242                                         match = 1;
 243                                         goto out;
 244                                 }
 245                                 if (match_value == NULL || dev_value == NULL)
 246                                         continue;
 247                                 if (fnmatch(match_value, dev_value, 0) == 0) {
 248                                         match = 1;
 249                                         goto out;
 250                                 }
 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         DIR *dir;
 265         struct dirent *dent;
 266
 267         util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
 268         util_strlcat(path, "/", sizeof(path));
 269         util_strlcat(path, basedir, sizeof(path));
 270         if (subdir1 != NULL) {
 271                 util_strlcat(path, "/", sizeof(path));
 272                 util_strlcat(path, subdir1, sizeof(path));
 273         }
 274         if (subdir2 != NULL) {
 275                 util_strlcat(path, "/", sizeof(path));
 276                 util_strlcat(path, subdir2, sizeof(path));
 277         }
 278         dir = opendir(path);
 279         if (dir == NULL)
 280                 return -1;
 281         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 282                 char syspath[UTIL_PATH_SIZE];
 283                 char filename[UTIL_PATH_SIZE];
 284                 struct stat statbuf;
 285
 286                 if (dent->d_name[0] == '.')
 287                         continue;
 288                 util_strlcpy(syspath, path, sizeof(syspath));
 289                 util_strlcat(syspath, "/", sizeof(syspath));
 290                 util_strlcat(syspath, dent->d_name, sizeof(syspath));
 291                 if (lstat(syspath, &statbuf) != 0)
 292                         continue;
 293                 if (S_ISREG(statbuf.st_mode))
 294                         continue;
 295                 if (S_ISLNK(statbuf.st_mode))
 296                         util_resolve_sys_link(udev, syspath, sizeof(syspath));
 297                 util_strlcpy(filename, syspath, sizeof(filename));
 298                 util_strlcat(filename, "/uevent", sizeof(filename));
 299                 if (stat(filename, &statbuf) != 0)
 300                         continue;
 301                 if (!match_sysattr(udev_enumerate, syspath))
 302                         continue;
 303                 if (!match_property(udev_enumerate, syspath))
 304                         continue;
 305                 udev_list_entry_add(udev, &udev_enumerate->devices_list, syspath, NULL, 1, 1);
 306         }
 307         closedir(dir);
 308         return 0;
 309 }
 310
 311 static int match_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
 312 {
 313         struct udev_list_entry *list_entry;
 314
 315         udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_nomatch_list)) {
 316                 if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
 317                         return 0;
 318         }
 319         if (udev_list_get_entry(&udev_enumerate->subsystem_match_list) != NULL) {
 320                 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_match_list)) {
 321                         if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
 322                                 return 1;
 323                 }
 324                 return 0;
 325         }
 326         return 1;
 327 }
 328
 329 static int scan_dir(struct udev_enumerate *udev_enumerate, const char *basedir, const char *subdir, const char *subsystem)
 330 {
 331         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 332
 333         char path[UTIL_PATH_SIZE];
 334         DIR *dir;
 335         struct dirent *dent;
 336
 337         util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
 338         util_strlcat(path, "/", sizeof(path));
 339         util_strlcat(path, basedir, sizeof(path));
 340         dir = opendir(path);
 341         if (dir == NULL)
 342                 return -1;
 343         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 344                 if (dent->d_name[0] == '.')
 345                         continue;
 346                 if (!match_subsystem(udev_enumerate, subsystem != NULL ? subsystem : dent->d_name))
 347                         continue;
 348                 scan_dir_and_add_devices(udev_enumerate, basedir, dent->d_name, subdir);
 349         }
 350         closedir(dir);
 351         return 0;
 352 }
 353
 354 static int devices_delay(struct udev *udev, const char *syspath)
 355 {
 356         static const char *delay_device_list[] = {
 357                 "/block/md",
 358                 "/block/dm-",
 359                 NULL
 360         };
 361         size_t len;
 362         int i;
 363
 364         len = strlen(udev_get_sys_path(udev));
 365         for (i = 0; delay_device_list[i] != NULL; i++) {
 366                 if (strstr(&syspath[len], delay_device_list[i]) != NULL) {
 367                         dbg(udev, "delaying: %s\n", syspath);
 368                         return 1;
 369                 }
 370         }
 371         return 0;
 372 }
 373
 374 /* sort delayed devices to the end of the list */
 375 static int devices_sort(struct udev_enumerate *udev_enumerate)
 376 {
 377         struct udev_list_entry *entry_loop;
 378         struct udev_list_entry *entry_tmp;
 379         struct udev_list_node devices_list;
 380
 381         udev_list_init(&devices_list);
 382         /* move delayed to delay list */
 383         udev_list_entry_foreach_safe(entry_loop, entry_tmp, udev_list_get_entry(&udev_enumerate->devices_list)) {
 384                 if (devices_delay(udev_enumerate->udev, udev_list_entry_get_name(entry_loop))) {
 385                         udev_list_entry_remove(entry_loop);
 386                         udev_list_entry_append(entry_loop, &devices_list);
 387                 }
 388         }
 389         /* move delayed back to end of list */
 390         udev_list_entry_foreach_safe(entry_loop, entry_tmp, udev_list_get_entry(&devices_list)) {
 391                 udev_list_entry_remove(entry_loop);
 392                 udev_list_entry_append(entry_loop, &udev_enumerate->devices_list);
 393         }
 394         udev_enumerate->devices_sorted = 1;
 395         return 0;
 396 }
 397
 398 int udev_enumerate_add_syspath(struct udev_enumerate *udev_enumerate, const char *syspath)
 399 {
 400         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 401         struct udev_device *udev_device;
 402
 403         if (udev_enumerate == NULL)
 404                 return -EINVAL;
 405         if (syspath == NULL)
 406                 return 0;
 407         /* resolve to real syspath */
 408         udev_device = udev_device_new_from_syspath(udev_enumerate->udev, syspath);
 409         if (udev_device == NULL)
 410                 return -EINVAL;
 411         udev_list_entry_add(udev, &udev_enumerate->devices_list,
 412                             udev_device_get_syspath(udev_device), NULL, 1, 1);
 413         udev_device_unref(udev_device);
 414         return 0;
 415 }
 416
 417 /**
 418  * udev_enumerate_scan_devices:
 419  * @udev_enumerate: udev enumeration context
 420  *
 421  * Returns: a negative value on error.
 422  **/
 423 int udev_enumerate_scan_devices(struct udev_enumerate *udev_enumerate)
 424 {
 425         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 426         char base[UTIL_PATH_SIZE];
 427         struct stat statbuf;
 428
 429         if (udev_enumerate == NULL)
 430                 return -EINVAL;
 431         util_strlcpy(base, udev_get_sys_path(udev), sizeof(base));
 432         util_strlcat(base, "/subsystem", sizeof(base));
 433         if (stat(base, &statbuf) == 0) {
 434                 /* we have /subsystem/, forget all the old stuff */
 435                 dbg(udev, "searching '/subsystem/*/devices/*' dir\n");
 436                 scan_dir(udev_enumerate, "subsystem", "devices", NULL);
 437         } else {
 438                 dbg(udev, "searching '/bus/*/devices/*' dir\n");
 439                 scan_dir(udev_enumerate, "bus", "devices", NULL);
 440                 dbg(udev, "searching '/class/*' dir\n");
 441                 scan_dir(udev_enumerate, "class", NULL, NULL);
 442                 /* if block isn't a class, scan /block/ */
 443                 util_strlcpy(base, udev_get_sys_path(udev), sizeof(base));
 444                 util_strlcat(base, "/class/block", sizeof(base));
 445                 if (stat(base, &statbuf) != 0) {
 446                         if (match_subsystem(udev_enumerate, "block")) {
 447                                 dbg(udev, "searching '/block/*' dir\n");
 448                                 /* scan disks */
 449                                 scan_dir_and_add_devices(udev_enumerate, "block", NULL, NULL);
 450                                 /* scan partitions */
 451                                 dbg(udev, "searching '/block/*/*' dir\n");
 452                                 scan_dir(udev_enumerate, "block", NULL, "block");
 453                         }
 454                 }
 455         }
 456         return 0;
 457 }
 458
 459 /**
 460  * udev_enumerate_scan_subsystems:
 461  * @udev_enumerate: udev enumeration context
 462  *
 463  * Returns: a negative value on error.
 464  **/
 465 int udev_enumerate_scan_subsystems(struct udev_enumerate *udev_enumerate)
 466 {
 467         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 468         char base[UTIL_PATH_SIZE];
 469         struct stat statbuf;
 470         const char *subsysdir;
 471
 472         if (udev_enumerate == NULL)
 473                 return -EINVAL;
 474         util_strlcpy(base, udev_get_sys_path(udev), sizeof(base));
 475         util_strlcat(base, "/subsystem", sizeof(base));
 476         if (stat(base, &statbuf) == 0)
 477                 subsysdir = "subsystem";
 478         else
 479                 subsysdir = "bus";
 480         if (match_subsystem(udev_enumerate, "subsystem")) {
 481                 dbg(udev, "searching '%s/*' dir\n", subsysdir);
 482                 scan_dir_and_add_devices(udev_enumerate, subsysdir, NULL, NULL);
 483         }
 484         if (match_subsystem(udev_enumerate, "drivers")) {
 485                 dbg(udev, "searching '%s/*/drivers/*' dir\n", subsysdir);
 486                 scan_dir(udev_enumerate, subsysdir, "drivers", "drivers");
 487         }
 488         return 0;
 489 }