udev/lib/libudev-device.c

   1 /*
   2  * libudev - interface to udev device information
   3  *
   4  * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <stddef.h>
  23 #include <unistd.h>
  24 #include <errno.h>
  25 #include <string.h>
  26 #include <dirent.h>
  27 #include <fcntl.h>
  28 #include <ctype.h>
  29 #include <sys/stat.h>
  30
  31 #include "libudev.h"
  32 #include "libudev-private.h"
  33
  34 struct udev_device {
  35         int refcount;
  36         struct udev *udev;
  37         struct udev_device *parent_device;
  38         char *syspath;
  39         const char *devpath;
  40         char *sysname;
  41         const char *sysnum;
  42         char *devnode;
  43         char *subsystem;
  44         struct udev_list_node devlinks_list;
  45         struct udev_list_node properties_list;
  46         char *envp[128];
  47         int envp_uptodate;
  48         char *driver;
  49         dev_t devnum;
  50         char *action;
  51         int event_timeout;
  52         char *devpath_old;
  53         char *physdevpath;
  54         int timeout;
  55         unsigned long long int seqnum;
  56         int num_fake_partitions;
  57         int devlink_priority;
  58         int ignore_remove;
  59         struct udev_list_node attr_list;
  60         int info_loaded;
  61 };
  62
  63 static size_t devpath_to_db_path(struct udev *udev, const char *devpath, char *filename, size_t len)
  64 {
  65         size_t start;
  66
  67         /* translate to location of db file */
  68         util_strlcpy(filename, udev_get_dev_path(udev), len);
  69         start = util_strlcat(filename, "/.udev/db/", len);
  70         util_strlcat(filename, devpath, len);
  71         return util_path_encode(&filename[start], len - start);
  72 }
  73
  74 static int device_read_db(struct udev_device *udev_device)
  75 {
  76         struct stat stats;
  77         char filename[UTIL_PATH_SIZE];
  78         char line[UTIL_LINE_SIZE];
  79         FILE *f;
  80
  81         devpath_to_db_path(udev_device->udev, udev_device->devpath, filename, sizeof(filename));
  82
  83         if (lstat(filename, &stats) != 0) {
  84                 info(udev_device->udev, "no db file to read %s: %m\n", filename);
  85                 return -1;
  86         }
  87         if ((stats.st_mode & S_IFMT) == S_IFLNK) {
  88                 char target[UTIL_PATH_SIZE];
  89                 char devnode[UTIL_PATH_SIZE];
  90                 int target_len;
  91                 char *next;
  92
  93                 target_len = readlink(filename, target, sizeof(target));
  94                 if (target_len > 0)
  95                         target[target_len] = '\0';
  96                 else {
  97                         info(udev_device->udev, "error reading db link %s: %m\n", filename);
  98                         return -1;
  99                 }
 100
 101                 next = strchr(target, ' ');
 102                 if (next != NULL) {
 103                         next[0] = '\0';
 104                         next = &next[1];
 105                 }
 106                 util_strlcpy(devnode, udev_get_dev_path(udev_device->udev), sizeof(devnode));
 107                 util_strlcat(devnode, "/", sizeof(devnode));
 108                 util_strlcat(devnode, target, sizeof(devnode));
 109                 udev_device_set_devnode(udev_device, devnode);
 110                 while (next != NULL) {
 111                         char devlink[UTIL_PATH_SIZE];
 112                         const char *lnk;
 113
 114                         lnk = next;
 115                         next = strchr(next, ' ');
 116                         if (next != NULL) {
 117                                 next[0] = '\0';
 118                                 next = &next[1];
 119                         }
 120                         util_strlcpy(devlink, udev_get_dev_path(udev_device->udev), sizeof(devlink));
 121                         util_strlcat(devlink, "/", sizeof(devlink));
 122                         util_strlcat(devlink, lnk, sizeof(devlink));
 123                         udev_device_add_devlink(udev_device, devlink);
 124                 }
 125                 info(udev_device->udev, "device %p filled with db symlink data '%s'\n", udev_device, udev_device->devnode);
 126                 return 0;
 127         }
 128
 129         f = fopen(filename, "r");
 130         if (f == NULL) {
 131                 info(udev_device->udev, "error reading db file %s: %m\n", filename);
 132                 return -1;
 133         }
 134         while (fgets(line, sizeof(line), f)) {
 135                 ssize_t len;
 136                 const char *val;
 137
 138                 len = strlen(line);
 139                 if (len < 4)
 140                         break;
 141                 line[len-1] = '\0';
 142                 val = &line[2];
 143                 switch(line[0]) {
 144                 case 'N':
 145                         util_strlcpy(filename, udev_get_dev_path(udev_device->udev), sizeof(filename));
 146                         util_strlcat(filename, "/", sizeof(filename));
 147                         util_strlcat(filename, val, sizeof(filename));
 148                         udev_device_set_devnode(udev_device, filename);
 149                         break;
 150                 case 'S':
 151                         util_strlcpy(filename, udev_get_dev_path(udev_device->udev), sizeof(filename));
 152                         util_strlcat(filename, "/", sizeof(filename));
 153                         util_strlcat(filename, val, sizeof(filename));
 154                         udev_device_add_devlink(udev_device, filename);
 155                         break;
 156                 case 'L':
 157                         udev_device_set_devlink_priority(udev_device, atoi(val));
 158                         break;
 159                 case 'T':
 160                         udev_device_set_event_timeout(udev_device, atoi(val));
 161                         break;
 162                 case 'A':
 163                         udev_device_set_num_fake_partitions(udev_device, atoi(val));
 164                         break;
 165                 case 'R':
 166                         udev_device_set_ignore_remove(udev_device, atoi(val));
 167                         break;
 168                 case 'E':
 169                         udev_device_add_property_from_string(udev_device, val);
 170                         break;
 171                 }
 172         }
 173         fclose(f);
 174
 175         info(udev_device->udev, "device %p filled with db file data\n", udev_device);
 176         return 0;
 177 }
 178
 179 static int device_read_uevent_file(struct udev_device *udev_device)
 180 {
 181         char filename[UTIL_PATH_SIZE];
 182         FILE *f;
 183         char line[UTIL_LINE_SIZE];
 184         int maj = 0;
 185         int min = 0;
 186
 187         util_strlcpy(filename, udev_device->syspath, sizeof(filename));
 188         util_strlcat(filename, "/uevent", sizeof(filename));
 189         f = fopen(filename, "r");
 190         if (f == NULL)
 191                 return -1;
 192
 193         while (fgets(line, sizeof(line), f)) {
 194                 char *pos;
 195
 196                 pos = strchr(line, '\n');
 197                 if (pos == NULL)
 198                         continue;
 199                 pos[0] = '\0';
 200
 201                 if (strncmp(line, "MAJOR=", 6) == 0)
 202                         maj = strtoull(&line[6], NULL, 10);
 203                 else if (strncmp(line, "MINOR=", 6) == 0)
 204                         min = strtoull(&line[6], NULL, 10);
 205
 206                 udev_device_add_property_from_string(udev_device, line);
 207         }
 208
 209         udev_device->devnum = makedev(maj, min);
 210
 211         fclose(f);
 212         return 0;
 213 }
 214
 215 static void device_load_info(struct udev_device *device)
 216 {
 217         device->info_loaded = 1;
 218         device_read_uevent_file(device);
 219         device_read_db(device);
 220 }
 221
 222 void udev_device_set_info_loaded(struct udev_device *device)
 223 {
 224         device->info_loaded = 1;
 225 }
 226
 227 struct udev_device *device_new(struct udev *udev)
 228 {
 229         struct udev_device *udev_device;
 230
 231         if (udev == NULL)
 232                 return NULL;
 233
 234         udev_device = malloc(sizeof(struct udev_device));
 235         if (udev_device == NULL)
 236                 return NULL;
 237         memset(udev_device, 0x00, sizeof(struct udev_device));
 238         udev_device->refcount = 1;
 239         udev_device->udev = udev;
 240         udev_list_init(&udev_device->devlinks_list);
 241         udev_list_init(&udev_device->properties_list);
 242         udev_list_init(&udev_device->attr_list);
 243         udev_device->event_timeout = -1;
 244         info(udev_device->udev, "udev_device: %p created\n", udev_device);
 245         return udev_device;
 246 }
 247
 248 /**
 249  * udev_device_new_from_syspath:
 250  * @udev: udev library context
 251  * @syspath: sys device path including sys directory
 252  *
 253  * Create new udev device, and fill in information from the sys
 254  * device and the udev database entry. The sypath is the absolute
 255  * path to the device, including the sys mount point.
 256  *
 257  * The initial refcount is 1, and needs to be decremented to
 258  * release the ressources of the udev device.
 259  *
 260  * Returns: a new udev device, or #NULL, if it does not exist
 261  **/
 262 struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *syspath)
 263 {
 264         size_t len;
 265         const char *subdir;
 266         char path[UTIL_PATH_SIZE];
 267         char *pos;
 268         struct stat statbuf;
 269         struct udev_device *udev_device;
 270
 271         if (udev == NULL)
 272                 return NULL;
 273         if (syspath == NULL)
 274                 return NULL;
 275
 276         /* path starts in sys */
 277         len = strlen(udev_get_sys_path(udev));
 278         if (strncmp(syspath, udev_get_sys_path(udev), len) != 0) {
 279                 info(udev, "not in sys :%s\n", syspath);
 280                 return NULL;
 281         }
 282
 283         /* path is not a root directory */
 284         subdir = &syspath[len+1];
 285         pos = strrchr(subdir, '/');
 286         if (pos == NULL || pos < &subdir[2]) {
 287                 info(udev, "not a subdir :%s\n", syspath);
 288                 return NULL;
 289         }
 290
 291         /* resolve possible symlink to real path */
 292         util_strlcpy(path, syspath, sizeof(path));
 293         util_resolve_sys_link(udev, path, sizeof(path));
 294
 295         /* try to resolve the silly block layout if needed */
 296         if (strncmp(&path[len], "/block/", 7) == 0) {
 297                 char block[UTIL_PATH_SIZE];
 298                 char part[UTIL_PATH_SIZE];
 299
 300                 util_strlcpy(block, path, sizeof(block));
 301                 pos = strrchr(block, '/');
 302                 if (pos == NULL)
 303                         return NULL;
 304                 util_strlcpy(part, pos, sizeof(part));
 305                 pos[0] = '\0';
 306                 if (util_resolve_sys_link(udev, block, sizeof(block)) == 0) {
 307                         util_strlcpy(path, block, sizeof(path));
 308                         util_strlcat(path, part, sizeof(path));
 309                 }
 310         }
 311
 312         /* path exists in sys */
 313         if (strncmp(&syspath[len], "/devices/", 9) == 0 ||
 314             strncmp(&syspath[len], "/class/", 7) == 0 ||
 315             strncmp(&syspath[len], "/block/", 7) == 0) {
 316                 char file[UTIL_PATH_SIZE];
 317
 318                 /* all "devices" require a "uevent" file */
 319                 util_strlcpy(file, path, sizeof(file));
 320                 util_strlcat(file, "/uevent", sizeof(file));
 321                 if (stat(file, &statbuf) != 0) {
 322                         info(udev, "not a device: %s\n", syspath);
 323                         return NULL;
 324                 }
 325         } else {
 326                 /* everything else just needs to be a directory */
 327                 if (stat(path, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode)) {
 328                         info(udev, "directory not found: %s\n", syspath);
 329                         return NULL;
 330                 }
 331         }
 332
 333         udev_device = device_new(udev);
 334         if (udev_device == NULL)
 335                 return NULL;
 336
 337         udev_device_set_syspath(udev_device, path);
 338         info(udev, "device %p has devpath '%s'\n", udev_device, udev_device_get_devpath(udev_device));
 339
 340         return udev_device;
 341 }
 342
 343 struct udev_device *udev_device_new_from_devnum(struct udev *udev, char type, dev_t devnum)
 344 {
 345         char path[UTIL_PATH_SIZE];
 346         const char *type_str;
 347         struct udev_enumerate *udev_enumerate;
 348         struct udev_list_entry *list_entry;
 349         struct udev_device *device = NULL;
 350
 351         if (type == 'b')
 352                 type_str = "block";
 353         else if (type == 'c')
 354                 type_str = "char";
 355         else
 356                 return NULL;
 357
 358         /* /sys/dev/{block,char}/<maj>:<min> link */
 359         snprintf(path, sizeof(path), "%s/dev/%s/%u:%u", udev_get_sys_path(udev),
 360                  type_str, major(devnum), minor(devnum));
 361         if (util_resolve_sys_link(udev, path, sizeof(path)) == 0)
 362                 return udev_device_new_from_syspath(udev, path);
 363
 364         udev_enumerate = udev_enumerate_new(udev);
 365         if (udev_enumerate == NULL)
 366                 return NULL;
 367
 368         /* fallback to search sys devices for the major/minor */
 369         if (type == 'b')
 370                 udev_enumerate_add_match_subsystem(udev_enumerate, "block");
 371         else if (type == 'c')
 372                 udev_enumerate_add_nomatch_subsystem(udev_enumerate, "block");
 373         udev_enumerate_scan_devices(udev_enumerate);
 374         udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(udev_enumerate)) {
 375                 struct udev_device *device_loop;
 376
 377                 device_loop = udev_device_new_from_syspath(udev, udev_list_entry_get_name(list_entry));
 378                 if (device_loop != NULL) {
 379                         if (udev_device_get_devnum(device_loop) == devnum) {
 380                                 if (type == 'b' && strcmp(udev_device_get_subsystem(device_loop), "block") != 0)
 381                                         continue;
 382                                 if (type == 'c' && strcmp(udev_device_get_subsystem(device_loop), "block") == 0)
 383                                         continue;
 384                                 device = device_loop;
 385                                 break;
 386                         }
 387                         udev_device_unref(device_loop);
 388                 }
 389         }
 390         udev_enumerate_unref(udev_enumerate);
 391         return device;
 392 }
 393
 394 struct udev_device *udev_device_new_from_subsystem_sysname(struct udev *udev, const char *subsystem, const char *sysname)
 395 {
 396         size_t sys_path_len;
 397         char path_full[UTIL_PATH_SIZE];
 398         char *path;
 399         struct stat statbuf;
 400
 401         sys_path_len = util_strlcpy(path_full, udev_get_sys_path(udev), sizeof(path_full));
 402         path = &path_full[sys_path_len];
 403
 404         if (strcmp(subsystem, "subsystem") == 0) {
 405                 util_strlcpy(path, "/subsystem/", sizeof(path_full) - sys_path_len);
 406                 util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
 407                 if (stat(path_full, &statbuf) == 0)
 408                         goto found;
 409
 410                 util_strlcpy(path, "/bus/", sizeof(path_full) - sys_path_len);
 411                 util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
 412                 if (stat(path_full, &statbuf) == 0)
 413                         goto found;
 414
 415                 util_strlcpy(path, "/class/", sizeof(path_full) - sys_path_len);
 416                 util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
 417                 if (stat(path_full, &statbuf) == 0)
 418                         goto found;
 419                 goto out;
 420         }
 421
 422         if (strcmp(subsystem, "module") == 0) {
 423                 util_strlcpy(path, "/module/", sizeof(path_full) - sys_path_len);
 424                 util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
 425                 if (stat(path_full, &statbuf) == 0)
 426                         goto found;
 427                 goto out;
 428         }
 429
 430         if (strcmp(subsystem, "drivers") == 0) {
 431                 char subsys[UTIL_NAME_SIZE];
 432                 char *driver;
 433
 434                 util_strlcpy(subsys, sysname, sizeof(subsys));
 435                 driver = strchr(subsys, ':');
 436                 if (driver != NULL) {
 437                         driver[0] = '\0';
 438                         driver = &driver[1];
 439                         util_strlcpy(path, "/subsystem/", sizeof(path_full) - sys_path_len);
 440                         util_strlcat(path, subsys, sizeof(path_full) - sys_path_len);
 441                         util_strlcat(path, "/drivers/", sizeof(path_full) - sys_path_len);
 442                         util_strlcat(path, driver, sizeof(path_full) - sys_path_len);
 443                         if (stat(path_full, &statbuf) == 0)
 444                                 goto found;
 445
 446                         util_strlcpy(path, "/bus/", sizeof(path_full) - sys_path_len);
 447                         util_strlcat(path, subsys, sizeof(path_full) - sys_path_len);
 448                         util_strlcat(path, "/drivers/", sizeof(path_full) - sys_path_len);
 449                         util_strlcat(path, driver, sizeof(path_full) - sys_path_len);
 450                         if (stat(path_full, &statbuf) == 0)
 451                                 goto found;
 452                 }
 453                 goto out;
 454         }
 455
 456         util_strlcpy(path, "/subsystem/", sizeof(path_full) - sys_path_len);
 457         util_strlcat(path, subsystem, sizeof(path_full) - sys_path_len);
 458         util_strlcat(path, "/devices/", sizeof(path_full) - sys_path_len);
 459         util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
 460         if (stat(path_full, &statbuf) == 0)
 461                 goto found;
 462
 463         util_strlcpy(path, "/bus/", sizeof(path_full) - sys_path_len);
 464         util_strlcat(path, subsystem, sizeof(path_full) - sys_path_len);
 465         util_strlcat(path, "/devices/", sizeof(path_full) - sys_path_len);
 466         util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
 467         if (stat(path_full, &statbuf) == 0)
 468                 goto found;
 469
 470         util_strlcpy(path, "/class/", sizeof(path_full) - sys_path_len);
 471         util_strlcat(path, subsystem, sizeof(path_full) - sys_path_len);
 472         util_strlcat(path, "/", sizeof(path_full) - sys_path_len);
 473         util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
 474         if (stat(path_full, &statbuf) == 0)
 475                 goto found;
 476 out:
 477         return NULL;
 478 found:
 479         return udev_device_new_from_syspath(udev, path_full);
 480 }
 481
 482 static struct udev_device *device_new_from_parent(struct udev_device *udev_device)
 483 {
 484         struct udev_device *udev_device_parent = NULL;
 485         char path[UTIL_PATH_SIZE];
 486         const char *subdir;
 487
 488         /* follow "device" link in deprecated sys layout */
 489         if (strncmp(udev_device->devpath, "/class/", 7) == 0 ||
 490             strncmp(udev_device->devpath, "/block/", 7) == 0) {
 491                 util_strlcpy(path, udev_device->syspath, sizeof(path));
 492                 util_strlcat(path, "/device", sizeof(path));
 493                 if (util_resolve_sys_link(udev_device->udev, path, sizeof(path)) == 0)
 494                         udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
 495                 return udev_device_parent;
 496         }
 497
 498         util_strlcpy(path, udev_device->syspath, sizeof(path));
 499         subdir = &path[strlen(udev_get_sys_path(udev_device->udev))+1];
 500         while (1) {
 501                 char *pos;
 502
 503                 pos = strrchr(subdir, '/');
 504                 if (pos == NULL || pos < &subdir[2])
 505                         break;
 506                 pos[0] = '\0';
 507                 udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
 508                 if (udev_device_parent != NULL)
 509                         return udev_device_parent;
 510         }
 511         return NULL;
 512 }
 513
 514 struct udev_device *udev_device_get_parent(struct udev_device *udev_device)
 515 {
 516         if (udev_device == NULL)
 517                 return NULL;
 518
 519         if (udev_device->parent_device != NULL) {
 520                 info(udev_device->udev, "returning existing parent %p\n", udev_device->parent_device);
 521                 return udev_device->parent_device;
 522         }
 523         udev_device->parent_device = device_new_from_parent(udev_device);
 524         return udev_device->parent_device;
 525 }
 526
 527 struct udev_device *udev_device_get_parent_with_subsystem(struct udev_device *udev_device, const char *subsystem)
 528 {
 529         struct udev_device *parent;
 530
 531         parent = udev_device_get_parent(udev_device);
 532         while (parent != NULL) {
 533                 const char *parent_subsystem;
 534
 535                 parent_subsystem = udev_device_get_subsystem(parent);
 536                 if (parent_subsystem != NULL && strcmp(parent_subsystem, subsystem) == 0)
 537                         break;
 538                 parent = udev_device_get_parent(parent);
 539         }
 540         return parent;
 541 }
 542
 543 /**
 544  * udev_device_get_udev:
 545  * @udev_device: udev device
 546  *
 547  * Retrieve the udev library context the device was created with.
 548  *
 549  * Returns: the udev library context
 550  **/
 551 struct udev *udev_device_get_udev(struct udev_device *udev_device)
 552 {
 553         if (udev_device == NULL)
 554                 return NULL;
 555         return udev_device->udev;
 556 }
 557
 558 /**
 559  * udev_device_ref:
 560  * @udev_device: udev device
 561  *
 562  * Take a reference of a udev device.
 563  *
 564  * Returns: the passed udev device
 565  **/
 566 struct udev_device *udev_device_ref(struct udev_device *udev_device)
 567 {
 568         if (udev_device == NULL)
 569                 return NULL;
 570         udev_device->refcount++;
 571         return udev_device;
 572 }
 573
 574 /**
 575  * udev_device_unref:
 576  * @udev_device: udev device
 577  *
 578  * Drop a reference of a udev device. If the refcount reaches zero,
 579  * the ressources of the device will be released.
 580  *
 581  **/
 582 void udev_device_unref(struct udev_device *udev_device)
 583 {
 584         unsigned int i;
 585
 586         if (udev_device == NULL)
 587                 return;
 588         udev_device->refcount--;
 589         if (udev_device->refcount > 0)
 590                 return;
 591         if (udev_device->parent_device != NULL)
 592                 udev_device_unref(udev_device->parent_device);
 593         free(udev_device->syspath);
 594         free(udev_device->sysname);
 595         free(udev_device->devnode);
 596         free(udev_device->subsystem);
 597         udev_list_cleanup(udev_device->udev, &udev_device->devlinks_list);
 598         udev_list_cleanup(udev_device->udev, &udev_device->properties_list);
 599         free(udev_device->action);
 600         free(udev_device->driver);
 601         free(udev_device->devpath_old);
 602         free(udev_device->physdevpath);
 603         udev_list_cleanup(udev_device->udev, &udev_device->attr_list);
 604         for (i = 0; i < ARRAY_SIZE(udev_device->envp) && udev_device->envp[i] != NULL; i++)
 605                 free(udev_device->envp[i]);
 606         info(udev_device->udev, "udev_device: %p released\n", udev_device);
 607         free(udev_device);
 608 }
 609
 610 /**
 611  * udev_device_get_devpath:
 612  * @udev_device: udev device
 613  *
 614  * Retrieve the kernel devpath value of the udev device. The path
 615  * does not contain the sys mount point, and starts with a '/'.
 616  *
 617  * Returns: the devpath of the udev device
 618  **/
 619 const char *udev_device_get_devpath(struct udev_device *udev_device)
 620 {
 621         if (udev_device == NULL)
 622                 return NULL;
 623         return udev_device->devpath;
 624 }
 625
 626 /**
 627  * udev_device_get_syspath:
 628  * @udev_device: udev device
 629  *
 630  * Retrieve the sys path of the udev device. The path is an
 631  * absolute path and starts with the sys mount point.
 632  *
 633  * Returns: the sys path of the udev device
 634  **/
 635 const char *udev_device_get_syspath(struct udev_device *udev_device)
 636 {
 637         if (udev_device == NULL)
 638                 return NULL;
 639         return udev_device->syspath;
 640 }
 641
 642 const char *udev_device_get_sysname(struct udev_device *udev_device)
 643 {
 644         if (udev_device == NULL)
 645                 return NULL;
 646         return udev_device->sysname;
 647 }
 648
 649 const char *udev_device_get_sysnum(struct udev_device *udev_device)
 650 {
 651         if (udev_device == NULL)
 652                 return NULL;
 653         return udev_device->sysnum;
 654 }
 655
 656 /**
 657  * udev_device_get_devnode:
 658  * @udev_device: udev device
 659  *
 660  * Retrieve the device node file name belonging to the udev device.
 661  * The path is an absolute path, and starts with the device directory.
 662  *
 663  * Returns: the device node file name of the udev device, or #NULL if no device node exists
 664  **/
 665 const char *udev_device_get_devnode(struct udev_device *udev_device)
 666 {
 667         if (udev_device == NULL)
 668                 return NULL;
 669         if (!udev_device->info_loaded)
 670                 device_load_info(udev_device);
 671         return udev_device->devnode;
 672 }
 673
 674 /**
 675  * udev_device_get_subsystem:
 676  * @udev_device: udev device
 677  *
 678  * Retrieve the subsystem string of the udev device. The string does not
 679  * contain any "/".
 680  *
 681  * Returns: the subsystem name of the udev device, or #NULL if it can not be determined
 682  **/
 683 const char *udev_device_get_subsystem(struct udev_device *udev_device)
 684 {
 685         char subsystem[UTIL_NAME_SIZE];
 686
 687         if (udev_device == NULL)
 688                 return NULL;
 689         if (udev_device->subsystem != NULL)
 690                 return udev_device->subsystem;
 691
 692         /* read "subsytem" link */
 693         if (util_get_sys_subsystem(udev_device->udev, udev_device->syspath, subsystem, sizeof(subsystem)) > 0) {
 694                 udev_device->subsystem = strdup(subsystem);
 695                 return udev_device->subsystem;
 696         }
 697
 698         /* implicit names */
 699         if (strncmp(udev_device->devpath, "/module/", 8) == 0) {
 700                 udev_device->subsystem = strdup("module");
 701                 return udev_device->subsystem;
 702         }
 703         if (strstr(udev_device->devpath, "/drivers/") != NULL) {
 704                 udev_device->subsystem = strdup("drivers");
 705                 return udev_device->subsystem;
 706         }
 707         if (strncmp(udev_device->devpath, "/subsystem/", 11) == 0 ||
 708             strncmp(udev_device->devpath, "/class/", 7) == 0 ||
 709             strncmp(udev_device->devpath, "/bus/", 5) == 0) {
 710                 udev_device->subsystem = strdup("subsystem");
 711                 return udev_device->subsystem;
 712         }
 713         return NULL;
 714 }
 715
 716 /**
 717  * udev_device_get_devlinks_list_entry:
 718  * @udev_device: udev device
 719  *
 720  * Retrieve the list of device links pointing to the device file of
 721  * the udev device. The next list entry can be retrieved with
 722  * udev_list_entry_next(), which returns #NULL if no more entries exist.
 723  * The devlink path can be retrieved from the list entry by
 724  * udev_list_entry_get_name(). The path is an absolute path, and starts with
 725  * the device directory.
 726  *
 727  * Returns: the first entry of the device node link list
 728  **/
 729 struct udev_list_entry *udev_device_get_devlinks_list_entry(struct udev_device *udev_device)
 730 {
 731         if (udev_device == NULL)
 732                 return NULL;
 733         if (!udev_device->info_loaded)
 734                 device_load_info(udev_device);
 735         return udev_list_get_entry(&udev_device->devlinks_list);
 736 }
 737
 738 void udev_device_cleanup_devlinks_list(struct udev_device *udev_device)
 739 {
 740         udev_list_cleanup(udev_device->udev, &udev_device->devlinks_list);
 741 }
 742
 743 /**
 744  * udev_device_get_properties_list_entry:
 745  * @udev_device: udev device
 746  *
 747  * Retrieve the list of key/value device properties of the udev
 748  * device. The next list entry can be retrieved with udev_list_entry_next(),
 749  * which returns #NULL if no more entries exist. The property name
 750  * can be retrieved from the list entry by udev_list_get_name(),
 751  * the property value by udev_list_get_value().
 752  *
 753  * Returns: the first entry of the property list
 754  **/
 755 struct udev_list_entry *udev_device_get_properties_list_entry(struct udev_device *udev_device)
 756 {
 757         if (udev_device == NULL)
 758                 return NULL;
 759         if (!udev_device->info_loaded)
 760                 device_load_info(udev_device);
 761         return udev_list_get_entry(&udev_device->properties_list);
 762 }
 763
 764 const char *udev_device_get_driver(struct udev_device *udev_device)
 765 {
 766         char driver[UTIL_NAME_SIZE];
 767
 768         if (udev_device == NULL)
 769                 return NULL;
 770         if (udev_device->driver != NULL)
 771                 return udev_device->driver;
 772         if (util_get_sys_driver(udev_device->udev, udev_device->syspath, driver, sizeof(driver)) < 2)
 773                 return NULL;
 774         udev_device->driver = strdup(driver);
 775         return udev_device->driver;
 776 }
 777
 778 dev_t udev_device_get_devnum(struct udev_device *udev_device)
 779 {
 780         if (udev_device == NULL)
 781                 return makedev(0, 0);
 782         if (!udev_device->info_loaded)
 783                 device_load_info(udev_device);
 784         return udev_device->devnum;
 785 }
 786
 787 const char *udev_device_get_action(struct udev_device *udev_device)
 788 {
 789         if (udev_device == NULL)
 790                 return NULL;
 791         return udev_device->action;
 792 }
 793
 794 unsigned long long int udev_device_get_seqnum(struct udev_device *udev_device)
 795 {
 796         if (udev_device == NULL)
 797                 return 0;
 798         return udev_device->seqnum;
 799 }
 800
 801 const char *udev_device_get_attr_value(struct udev_device *udev_device, const char *attr)
 802 {
 803         struct udev_list_entry *list_entry;
 804         char path[UTIL_PATH_SIZE];
 805         char value[UTIL_NAME_SIZE];
 806         struct stat statbuf;
 807         int fd;
 808         ssize_t size;
 809         const char *val = NULL;
 810
 811         if (udev_device == NULL)
 812                 return NULL;
 813         if (attr == NULL)
 814                 return NULL;
 815
 816         /* look for possibly already cached result */
 817         udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_device->attr_list)) {
 818                 if (strcmp(udev_list_entry_get_name(list_entry), attr) == 0) {
 819                         info(udev_device->udev, "got '%s' (%s) from cache\n",
 820                              attr, udev_list_entry_get_value(list_entry));
 821                         return udev_list_entry_get_value(list_entry);
 822                 }
 823         }
 824
 825         util_strlcpy(path, udev_device_get_syspath(udev_device), sizeof(path));
 826         util_strlcat(path, "/", sizeof(path));
 827         util_strlcat(path, attr, sizeof(path));
 828
 829         if (lstat(path, &statbuf) != 0) {
 830                 info(udev_device->udev, "stat '%s' failed: %m\n", path);
 831                 goto out;
 832         }
 833
 834         if (S_ISLNK(statbuf.st_mode)) {
 835                 /* links return the last element of the target path */
 836                 char target[UTIL_NAME_SIZE];
 837                 int len;
 838                 char *pos;
 839
 840                 len = readlink(path, target, sizeof(target));
 841                 if (len > 0) {
 842                         target[len] = '\0';
 843                         pos = strrchr(target, '/');
 844                         if (pos != NULL) {
 845                                 pos = &pos[1];
 846                                 info(udev_device->udev, "cache '%s' with link value '%s'\n", attr, pos);
 847                                 list_entry = udev_list_entry_add(udev_device->udev, &udev_device->attr_list, attr, pos, 0, 0);
 848                                 val = udev_list_entry_get_value(list_entry);
 849                         }
 850                 }
 851                 goto out;
 852         }
 853
 854         /* skip directories */
 855         if (S_ISDIR(statbuf.st_mode))
 856                 goto out;
 857
 858         /* skip non-readable files */
 859         if ((statbuf.st_mode & S_IRUSR) == 0)
 860                 goto out;
 861
 862         /* read attribute value */
 863         fd = open(path, O_RDONLY);
 864         if (fd < 0) {
 865                 info(udev_device->udev, "attribute '%s' can not be opened\n", path);
 866                 goto out;
 867         }
 868         size = read(fd, value, sizeof(value));
 869         close(fd);
 870         if (size < 0)
 871                 goto out;
 872         if (size == sizeof(value))
 873                 goto out;
 874
 875         /* got a valid value, store it in cache and return it */
 876         value[size] = '\0';
 877         util_remove_trailing_chars(value, '\n');
 878         info(udev_device->udev, "'%s' has attribute value '%s'\n", path, value);
 879         list_entry = udev_list_entry_add(udev_device->udev, &udev_device->attr_list, attr, value, 0, 0);
 880         val = udev_list_entry_get_value(list_entry);
 881 out:
 882         return val;
 883 }
 884
 885 int udev_device_set_syspath(struct udev_device *udev_device, const char *syspath)
 886 {
 887         const char *pos;
 888         size_t len;
 889
 890         free(udev_device->syspath);
 891         udev_device->syspath = strdup(syspath);
 892         if (udev_device->syspath ==  NULL)
 893                 return -ENOMEM;
 894         udev_device->devpath = &udev_device->syspath[strlen(udev_get_sys_path(udev_device->udev))];
 895         udev_device_add_property(udev_device, "DEVPATH", udev_device->devpath);
 896
 897         pos = strrchr(udev_device->syspath, '/');
 898         if (pos == NULL)
 899                 return -EINVAL;
 900         udev_device->sysname = strdup(&pos[1]);
 901         if (udev_device->sysname == NULL)
 902                 return -ENOMEM;
 903
 904         /* some devices have '!' in their name, change that to '/' */
 905         len = 0;
 906         while (udev_device->sysname[len] != '\0') {
 907                 if (udev_device->sysname[len] == '!')
 908                         udev_device->sysname[len] = '/';
 909                 len++;
 910         }
 911
 912         /* trailing number */
 913         while (isdigit(udev_device->sysname[--len]))
 914                 udev_device->sysnum = &udev_device->sysname[len];
 915         return 0;
 916 }
 917
 918 int udev_device_set_subsystem(struct udev_device *udev_device, const char *subsystem)
 919 {
 920         free(udev_device->subsystem);
 921         udev_device->subsystem = strdup(subsystem);
 922         if (udev_device->subsystem == NULL)
 923                 return -ENOMEM;
 924         udev_device_add_property(udev_device, "SUBSYSTEM", udev_device->subsystem);
 925         return 0;
 926 }
 927
 928 int udev_device_set_devnode(struct udev_device *udev_device, const char *devnode)
 929 {
 930         free(udev_device->devnode);
 931         udev_device->devnode = strdup(devnode);
 932         if (udev_device->devnode == NULL)
 933                 return -ENOMEM;
 934         udev_device_add_property(udev_device, "DEVNAME", udev_device->devnode);
 935         return 0;
 936 }
 937
 938 int udev_device_add_devlink(struct udev_device *udev_device, const char *devlink)
 939 {
 940         char symlinks[UTIL_PATH_SIZE];
 941         struct udev_list_entry *list_entry;
 942
 943         if (udev_list_entry_add(udev_device->udev, &udev_device->devlinks_list, devlink, NULL, 1, 0) == NULL)
 944                 return -ENOMEM;
 945         list_entry =  udev_device_get_devlinks_list_entry(udev_device);
 946         util_strlcpy(symlinks, udev_list_entry_get_name(list_entry), sizeof(symlinks));
 947         udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry)) {
 948                 util_strlcat(symlinks, " ", sizeof(symlinks));
 949                 util_strlcat(symlinks, udev_list_entry_get_name(list_entry), sizeof(symlinks));
 950         }
 951         udev_device_add_property(udev_device, "DEVLINKS", symlinks);
 952         return 0;
 953 }
 954
 955 struct udev_list_entry *udev_device_add_property(struct udev_device *udev_device, const char *key, const char *value)
 956 {
 957         udev_device->envp_uptodate = 0;
 958         return udev_list_entry_add(udev_device->udev, &udev_device->properties_list, key, value, 1, 0);
 959 }
 960
 961 struct udev_list_entry *udev_device_add_property_from_string(struct udev_device *udev_device, const char *property)
 962 {
 963         char name[UTIL_PATH_SIZE];
 964         char *val;
 965
 966         strncpy(name, property, sizeof(name));
 967         val = strchr(name, '=');
 968         if (val == NULL)
 969                 return NULL;
 970         val[0] = '\0';
 971         val = &val[1];
 972         if (val[0] == '\0')
 973                 val = NULL;
 974         return udev_device_add_property(udev_device, name, val);
 975 }
 976
 977 char **udev_device_get_properties_envp(struct udev_device *udev_device)
 978 {
 979         if (!udev_device->envp_uptodate) {
 980                 unsigned int i;
 981                 struct udev_list_entry *list_entry;
 982
 983                 for (i = 0; i < ARRAY_SIZE(udev_device->envp) && udev_device->envp[i] != NULL; i++)
 984                         free(udev_device->envp[i]);
 985                 i = 0;
 986                 udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) {
 987                         asprintf(&udev_device->envp[i++], "%s=%s",
 988                                  udev_list_entry_get_name(list_entry),
 989                                  udev_list_entry_get_value(list_entry));
 990                         if (i+1 >= ARRAY_SIZE(udev_device->envp))
 991                                 break;
 992                 }
 993                 udev_device->envp[i] = NULL;
 994                 info(udev_device->udev, "constructed envp from %u properties\n", i);
 995                 udev_device->envp_uptodate = 1;
 996         }
 997         return udev_device->envp;
 998 }
 999
1000 int udev_device_set_action(struct udev_device *udev_device, const char *action)
1001 {
1002         free(udev_device->action);
1003         udev_device->action = strdup(action);
1004         if (udev_device->action == NULL)
1005                 return -ENOMEM;
1006         udev_device_add_property(udev_device, "ACTION", action);
1007         return 0;
1008 }
1009
1010 int udev_device_set_driver(struct udev_device *udev_device, const char *driver)
1011 {
1012         free(udev_device->driver);
1013         udev_device->driver = strdup(driver);
1014         if (udev_device->driver == NULL)
1015                 return -ENOMEM;
1016         return 0;
1017 }
1018
1019 const char *udev_device_get_devpath_old(struct udev_device *udev_device)
1020 {
1021         return udev_device->devpath_old;
1022 }
1023
1024 int udev_device_set_devpath_old(struct udev_device *udev_device, const char *devpath_old)
1025 {
1026         udev_device->devpath_old = strdup(devpath_old);
1027         if (udev_device->devpath_old == NULL)
1028                 return -ENOMEM;
1029         return 0;
1030 }
1031
1032 const char *udev_device_get_physdevpath(struct udev_device *udev_device)
1033 {
1034         return udev_device->physdevpath;
1035 }
1036
1037 int udev_device_set_physdevpath(struct udev_device *udev_device, const char *physdevpath)
1038 {
1039         udev_device->physdevpath = strdup(physdevpath);
1040         if (udev_device->physdevpath == NULL)
1041                 return -ENOMEM;
1042         return 0;
1043 }
1044
1045 int udev_device_get_timeout(struct udev_device *udev_device)
1046 {
1047         return udev_device->timeout;
1048 }
1049
1050 int udev_device_set_timeout(struct udev_device *udev_device, int timeout)
1051 {
1052         udev_device->timeout = timeout;
1053         return 0;
1054 }
1055 int udev_device_get_event_timeout(struct udev_device *udev_device)
1056 {
1057         if (!udev_device->info_loaded)
1058                 device_load_info(udev_device);
1059         return udev_device->event_timeout;
1060 }
1061
1062 int udev_device_set_event_timeout(struct udev_device *udev_device, int event_timeout)
1063 {
1064         udev_device->event_timeout = event_timeout;
1065         return 0;
1066 }
1067
1068 int udev_device_set_seqnum(struct udev_device *udev_device, unsigned long long int seqnum)
1069 {
1070         udev_device->seqnum = seqnum;
1071         return 0;
1072 }
1073
1074 int udev_device_set_devnum(struct udev_device *udev_device, dev_t devnum)
1075 {
1076         udev_device->devnum = devnum;
1077         return 0;
1078 }
1079
1080 int udev_device_get_num_fake_partitions(struct udev_device *udev_device)
1081 {
1082         if (!udev_device->info_loaded)
1083                 device_load_info(udev_device);
1084         return udev_device->num_fake_partitions;
1085 }
1086
1087 int udev_device_set_num_fake_partitions(struct udev_device *udev_device, int num)
1088 {
1089         udev_device->num_fake_partitions = num;
1090         return 0;
1091 }
1092
1093 int udev_device_get_devlink_priority(struct udev_device *udev_device)
1094 {
1095         if (!udev_device->info_loaded)
1096                 device_load_info(udev_device);
1097         return udev_device->devlink_priority;
1098 }
1099
1100 int udev_device_set_devlink_priority(struct udev_device *udev_device, int prio)
1101 {
1102          udev_device->devlink_priority = prio;
1103         return 0;
1104 }
1105
1106 int udev_device_get_ignore_remove(struct udev_device *udev_device)
1107 {
1108         if (!udev_device->info_loaded)
1109                 device_load_info(udev_device);
1110         return udev_device->ignore_remove;
1111 }
1112
1113 int udev_device_set_ignore_remove(struct udev_device *udev_device, int ignore)
1114 {
1115         udev_device->ignore_remove = ignore;
1116         return 0;
1117 }