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         int subsystem_set;
  45         struct udev_list_node devlinks_list;
  46         int devlinks_uptodate;
  47         struct udev_list_node properties_list;
  48         char *envp[128];
  49         int envp_uptodate;
  50         char *driver;
  51         int driver_set;
  52         dev_t devnum;
  53         char *action;
  54         int event_timeout;
  55         char *devpath_old;
  56         char *physdevpath;
  57         int timeout;
  58         unsigned long long int seqnum;
  59         int num_fake_partitions;
  60         int devlink_priority;
  61         int ignore_remove;
  62         struct udev_list_node attr_list;
  63         int info_loaded;
  64 };
  65
  66 static size_t devpath_to_db_path(struct udev *udev, const char *devpath, char *filename, size_t len)
  67 {
  68         size_t start;
  69
  70         /* translate to location of db file */
  71         util_strlcpy(filename, udev_get_dev_path(udev), len);
  72         start = util_strlcat(filename, "/.udev/db/", len);
  73         util_strlcat(filename, devpath, len);
  74         return util_path_encode(&filename[start], len - start);
  75 }
  76
  77 static int device_read_db(struct udev_device *udev_device)
  78 {
  79         struct stat stats;
  80         char filename[UTIL_PATH_SIZE];
  81         char line[UTIL_LINE_SIZE];
  82         FILE *f;
  83
  84         devpath_to_db_path(udev_device->udev, udev_device->devpath, filename, sizeof(filename));
  85
  86         if (lstat(filename, &stats) != 0) {
  87                 info(udev_device->udev, "no db file to read %s: %m\n", filename);
  88                 return -1;
  89         }
  90         if ((stats.st_mode & S_IFMT) == S_IFLNK) {
  91                 char target[UTIL_PATH_SIZE];
  92                 char devnode[UTIL_PATH_SIZE];
  93                 int target_len;
  94                 char *next;
  95
  96                 target_len = readlink(filename, target, sizeof(target));
  97                 if (target_len > 0)
  98                         target[target_len] = '\0';
  99                 else {
 100                         info(udev_device->udev, "error reading db link %s: %m\n", filename);
 101                         return -1;
 102                 }
 103
 104                 next = strchr(target, ' ');
 105                 if (next != NULL) {
 106                         next[0] = '\0';
 107                         next = &next[1];
 108                 }
 109                 util_strlcpy(devnode, udev_get_dev_path(udev_device->udev), sizeof(devnode));
 110                 util_strlcat(devnode, "/", sizeof(devnode));
 111                 util_strlcat(devnode, target, sizeof(devnode));
 112                 udev_device_set_devnode(udev_device, devnode);
 113                 while (next != NULL) {
 114                         char devlink[UTIL_PATH_SIZE];
 115                         const char *lnk;
 116
 117                         lnk = next;
 118                         next = strchr(next, ' ');
 119                         if (next != NULL) {
 120                                 next[0] = '\0';
 121                                 next = &next[1];
 122                         }
 123                         util_strlcpy(devlink, udev_get_dev_path(udev_device->udev), sizeof(devlink));
 124                         util_strlcat(devlink, "/", sizeof(devlink));
 125                         util_strlcat(devlink, lnk, sizeof(devlink));
 126                         udev_device_add_devlink(udev_device, devlink);
 127                 }
 128                 info(udev_device->udev, "device %p filled with db symlink data '%s'\n", udev_device, udev_device->devnode);
 129                 return 0;
 130         }
 131
 132         f = fopen(filename, "r");
 133         if (f == NULL) {
 134                 info(udev_device->udev, "error reading db file %s: %m\n", filename);
 135                 return -1;
 136         }
 137         while (fgets(line, sizeof(line), f)) {
 138                 ssize_t len;
 139                 const char *val;
 140
 141                 len = strlen(line);
 142                 if (len < 4)
 143                         break;
 144                 line[len-1] = '\0';
 145                 val = &line[2];
 146                 switch(line[0]) {
 147                 case 'N':
 148                         util_strlcpy(filename, udev_get_dev_path(udev_device->udev), sizeof(filename));
 149                         util_strlcat(filename, "/", sizeof(filename));
 150                         util_strlcat(filename, val, sizeof(filename));
 151                         udev_device_set_devnode(udev_device, filename);
 152                         break;
 153                 case 'S':
 154                         util_strlcpy(filename, udev_get_dev_path(udev_device->udev), sizeof(filename));
 155                         util_strlcat(filename, "/", sizeof(filename));
 156                         util_strlcat(filename, val, sizeof(filename));
 157                         udev_device_add_devlink(udev_device, filename);
 158                         break;
 159                 case 'L':
 160                         udev_device_set_devlink_priority(udev_device, atoi(val));
 161                         break;
 162                 case 'T':
 163                         udev_device_set_event_timeout(udev_device, atoi(val));
 164                         break;
 165                 case 'A':
 166                         udev_device_set_num_fake_partitions(udev_device, atoi(val));
 167                         break;
 168                 case 'R':
 169                         udev_device_set_ignore_remove(udev_device, atoi(val));
 170                         break;
 171                 case 'E':
 172                         udev_device_add_property_from_string(udev_device, val);
 173                         break;
 174                 }
 175         }
 176         fclose(f);
 177
 178         info(udev_device->udev, "device %p filled with db file data\n", udev_device);
 179         return 0;
 180 }
 181
 182 int udev_device_read_uevent_file(struct udev_device *udev_device)
 183 {
 184         char filename[UTIL_PATH_SIZE];
 185         FILE *f;
 186         char line[UTIL_LINE_SIZE];
 187         int maj = 0;
 188         int min = 0;
 189
 190         util_strlcpy(filename, udev_device->syspath, sizeof(filename));
 191         util_strlcat(filename, "/uevent", sizeof(filename));
 192         f = fopen(filename, "r");
 193         if (f == NULL)
 194                 return -1;
 195
 196         while (fgets(line, sizeof(line), f)) {
 197                 char *pos;
 198
 199                 pos = strchr(line, '\n');
 200                 if (pos == NULL)
 201                         continue;
 202                 pos[0] = '\0';
 203
 204                 if (strncmp(line, "MAJOR=", 6) == 0)
 205                         maj = strtoull(&line[6], NULL, 10);
 206                 else if (strncmp(line, "MINOR=", 6) == 0)
 207                         min = strtoull(&line[6], NULL, 10);
 208
 209                 udev_device_add_property_from_string(udev_device, line);
 210         }
 211
 212         udev_device->devnum = makedev(maj, min);
 213
 214         fclose(f);
 215         return 0;
 216 }
 217
 218 static void device_load_info(struct udev_device *device)
 219 {
 220         device->info_loaded = 1;
 221         udev_device_read_uevent_file(device);
 222         device_read_db(device);
 223 }
 224
 225 void udev_device_set_info_loaded(struct udev_device *device)
 226 {
 227         device->info_loaded = 1;
 228 }
 229
 230 struct udev_device *device_new(struct udev *udev)
 231 {
 232         struct udev_device *udev_device;
 233
 234         if (udev == NULL)
 235                 return NULL;
 236
 237         udev_device = malloc(sizeof(struct udev_device));
 238         if (udev_device == NULL)
 239                 return NULL;
 240         memset(udev_device, 0x00, sizeof(struct udev_device));
 241         udev_device->refcount = 1;
 242         udev_device->udev = udev;
 243         udev_list_init(&udev_device->devlinks_list);
 244         udev_list_init(&udev_device->properties_list);
 245         udev_list_init(&udev_device->attr_list);
 246         udev_device->event_timeout = -1;
 247         info(udev_device->udev, "udev_device: %p created\n", udev_device);
 248         return udev_device;
 249 }
 250
 251 /**
 252  * udev_device_new_from_syspath:
 253  * @udev: udev library context
 254  * @syspath: sys device path including sys directory
 255  *
 256  * Create new udev device, and fill in information from the sys
 257  * device and the udev database entry. The sypath is the absolute
 258  * path to the device, including the sys mount point.
 259  *
 260  * The initial refcount is 1, and needs to be decremented to
 261  * release the ressources of the udev device.
 262  *
 263  * Returns: a new udev device, or #NULL, if it does not exist
 264  **/
 265 struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *syspath)
 266 {
 267         size_t len;
 268         const char *subdir;
 269         char path[UTIL_PATH_SIZE];
 270         char *pos;
 271         struct stat statbuf;
 272         struct udev_device *udev_device;
 273
 274         if (udev == NULL)
 275                 return NULL;
 276         if (syspath == NULL)
 277                 return NULL;
 278
 279         /* path starts in sys */
 280         len = strlen(udev_get_sys_path(udev));
 281         if (strncmp(syspath, udev_get_sys_path(udev), len) != 0) {
 282                 info(udev, "not in sys :%s\n", syspath);
 283                 return NULL;
 284         }
 285
 286         /* path is not a root directory */
 287         subdir = &syspath[len+1];
 288         pos = strrchr(subdir, '/');
 289         if (pos == NULL || pos < &subdir[2]) {
 290                 info(udev, "not a subdir :%s\n", syspath);
 291                 return NULL;
 292         }
 293
 294         /* resolve possible symlink to real path */
 295         util_strlcpy(path, syspath, sizeof(path));
 296         util_resolve_sys_link(udev, path, sizeof(path));
 297
 298         /* try to resolve the silly block layout if needed */
 299         if (strncmp(&path[len], "/block/", 7) == 0) {
 300                 char block[UTIL_PATH_SIZE];
 301                 char part[UTIL_PATH_SIZE];
 302
 303                 util_strlcpy(block, path, sizeof(block));
 304                 pos = strrchr(block, '/');
 305                 if (pos == NULL)
 306                         return NULL;
 307                 util_strlcpy(part, pos, sizeof(part));
 308                 pos[0] = '\0';
 309                 if (util_resolve_sys_link(udev, block, sizeof(block)) == 0) {
 310                         util_strlcpy(path, block, sizeof(path));
 311                         util_strlcat(path, part, sizeof(path));
 312                 }
 313         }
 314
 315         /* path exists in sys */
 316         if (strncmp(&syspath[len], "/devices/", 9) == 0 ||
 317             strncmp(&syspath[len], "/class/", 7) == 0 ||
 318             strncmp(&syspath[len], "/block/", 7) == 0) {
 319                 char file[UTIL_PATH_SIZE];
 320
 321                 /* all "devices" require a "uevent" file */
 322                 util_strlcpy(file, path, sizeof(file));
 323                 util_strlcat(file, "/uevent", sizeof(file));
 324                 if (stat(file, &statbuf) != 0) {
 325                         info(udev, "not a device: %s\n", syspath);
 326                         return NULL;
 327                 }
 328         } else {
 329                 /* everything else just needs to be a directory */
 330                 if (stat(path, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode)) {
 331                         info(udev, "directory not found: %s\n", syspath);
 332                         return NULL;
 333                 }
 334         }
 335
 336         udev_device = device_new(udev);
 337         if (udev_device == NULL)
 338                 return NULL;
 339
 340         udev_device_set_syspath(udev_device, path);
 341         info(udev, "device %p has devpath '%s'\n", udev_device, udev_device_get_devpath(udev_device));
 342
 343         return udev_device;
 344 }
 345
 346 struct udev_device *udev_device_new_from_devnum(struct udev *udev, char type, dev_t devnum)
 347 {
 348         char path[UTIL_PATH_SIZE];
 349         const char *type_str;
 350         struct udev_enumerate *udev_enumerate;
 351         struct udev_list_entry *list_entry;
 352         struct udev_device *device = NULL;
 353
 354         if (type == 'b')
 355                 type_str = "block";
 356         else if (type == 'c')
 357                 type_str = "char";
 358         else
 359                 return NULL;
 360
 361         /* /sys/dev/{block,char}/<maj>:<min> link */
 362         snprintf(path, sizeof(path), "%s/dev/%s/%u:%u", udev_get_sys_path(udev),
 363                  type_str, major(devnum), minor(devnum));
 364         if (util_resolve_sys_link(udev, path, sizeof(path)) == 0)
 365                 return udev_device_new_from_syspath(udev, path);
 366
 367         udev_enumerate = udev_enumerate_new(udev);
 368         if (udev_enumerate == NULL)
 369                 return NULL;
 370
 371         /* fallback to search sys devices for the major/minor */
 372         if (type == 'b')
 373                 udev_enumerate_add_match_subsystem(udev_enumerate, "block");
 374         else if (type == 'c')
 375                 udev_enumerate_add_nomatch_subsystem(udev_enumerate, "block");
 376         udev_enumerate_scan_devices(udev_enumerate);
 377         udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(udev_enumerate)) {
 378                 struct udev_device *device_loop;
 379
 380                 device_loop = udev_device_new_from_syspath(udev, udev_list_entry_get_name(list_entry));
 381                 if (device_loop != NULL) {
 382                         if (udev_device_get_devnum(device_loop) == devnum) {
 383                                 if (type == 'b' && strcmp(udev_device_get_subsystem(device_loop), "block") != 0)
 384                                         continue;
 385                                 if (type == 'c' && strcmp(udev_device_get_subsystem(device_loop), "block") == 0)
 386                                         continue;
 387                                 device = device_loop;
 388                                 break;
 389                         }
 390                         udev_device_unref(device_loop);
 391                 }
 392         }
 393         udev_enumerate_unref(udev_enumerate);
 394         return device;
 395 }
 396
 397 struct udev_device *udev_device_new_from_subsystem_sysname(struct udev *udev, const char *subsystem, const char *sysname)
 398 {
 399         size_t sys_path_len;
 400         char path_full[UTIL_PATH_SIZE];
 401         char *path;
 402         struct stat statbuf;
 403
 404         sys_path_len = util_strlcpy(path_full, udev_get_sys_path(udev), sizeof(path_full));
 405         path = &path_full[sys_path_len];
 406
 407         if (strcmp(subsystem, "subsystem") == 0) {
 408                 util_strlcpy(path, "/subsystem/", sizeof(path_full) - sys_path_len);
 409                 util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
 410                 if (stat(path_full, &statbuf) == 0)
 411                         goto found;
 412
 413                 util_strlcpy(path, "/bus/", sizeof(path_full) - sys_path_len);
 414                 util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
 415                 if (stat(path_full, &statbuf) == 0)
 416                         goto found;
 417
 418                 util_strlcpy(path, "/class/", sizeof(path_full) - sys_path_len);
 419                 util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
 420                 if (stat(path_full, &statbuf) == 0)
 421                         goto found;
 422                 goto out;
 423         }
 424
 425         if (strcmp(subsystem, "module") == 0) {
 426                 util_strlcpy(path, "/module/", sizeof(path_full) - sys_path_len);
 427                 util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
 428                 if (stat(path_full, &statbuf) == 0)
 429                         goto found;
 430                 goto out;
 431         }
 432
 433         if (strcmp(subsystem, "drivers") == 0) {
 434                 char subsys[UTIL_NAME_SIZE];
 435                 char *driver;
 436
 437                 util_strlcpy(subsys, sysname, sizeof(subsys));
 438                 driver = strchr(subsys, ':');
 439                 if (driver != NULL) {
 440                         driver[0] = '\0';
 441                         driver = &driver[1];
 442                         util_strlcpy(path, "/subsystem/", sizeof(path_full) - sys_path_len);
 443                         util_strlcat(path, subsys, sizeof(path_full) - sys_path_len);
 444                         util_strlcat(path, "/drivers/", sizeof(path_full) - sys_path_len);
 445                         util_strlcat(path, driver, sizeof(path_full) - sys_path_len);
 446                         if (stat(path_full, &statbuf) == 0)
 447                                 goto found;
 448
 449                         util_strlcpy(path, "/bus/", sizeof(path_full) - sys_path_len);
 450                         util_strlcat(path, subsys, sizeof(path_full) - sys_path_len);
 451                         util_strlcat(path, "/drivers/", sizeof(path_full) - sys_path_len);
 452                         util_strlcat(path, driver, sizeof(path_full) - sys_path_len);
 453                         if (stat(path_full, &statbuf) == 0)
 454                                 goto found;
 455                 }
 456                 goto out;
 457         }
 458
 459         util_strlcpy(path, "/subsystem/", sizeof(path_full) - sys_path_len);
 460         util_strlcat(path, subsystem, sizeof(path_full) - sys_path_len);
 461         util_strlcat(path, "/devices/", sizeof(path_full) - sys_path_len);
 462         util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
 463         if (stat(path_full, &statbuf) == 0)
 464                 goto found;
 465
 466         util_strlcpy(path, "/bus/", sizeof(path_full) - sys_path_len);
 467         util_strlcat(path, subsystem, sizeof(path_full) - sys_path_len);
 468         util_strlcat(path, "/devices/", sizeof(path_full) - sys_path_len);
 469         util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
 470         if (stat(path_full, &statbuf) == 0)
 471                 goto found;
 472
 473         util_strlcpy(path, "/class/", sizeof(path_full) - sys_path_len);
 474         util_strlcat(path, subsystem, sizeof(path_full) - sys_path_len);
 475         util_strlcat(path, "/", sizeof(path_full) - sys_path_len);
 476         util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
 477         if (stat(path_full, &statbuf) == 0)
 478                 goto found;
 479 out:
 480         return NULL;
 481 found:
 482         return udev_device_new_from_syspath(udev, path_full);
 483 }
 484
 485 static struct udev_device *device_new_from_parent(struct udev_device *udev_device)
 486 {
 487         struct udev_device *udev_device_parent = NULL;
 488         char path[UTIL_PATH_SIZE];
 489         const char *subdir;
 490
 491         /* follow "device" link in deprecated sys layout */
 492         if (strncmp(udev_device->devpath, "/class/", 7) == 0 ||
 493             strncmp(udev_device->devpath, "/block/", 7) == 0) {
 494                 util_strlcpy(path, udev_device->syspath, sizeof(path));
 495                 util_strlcat(path, "/device", sizeof(path));
 496                 if (util_resolve_sys_link(udev_device->udev, path, sizeof(path)) == 0)
 497                         udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
 498                 return udev_device_parent;
 499         }
 500
 501         util_strlcpy(path, udev_device->syspath, sizeof(path));
 502         subdir = &path[strlen(udev_get_sys_path(udev_device->udev))+1];
 503         while (1) {
 504                 char *pos;
 505
 506                 pos = strrchr(subdir, '/');
 507                 if (pos == NULL || pos < &subdir[2])
 508                         break;
 509                 pos[0] = '\0';
 510                 udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
 511                 if (udev_device_parent != NULL)
 512                         return udev_device_parent;
 513         }
 514         return NULL;
 515 }
 516
 517 struct udev_device *udev_device_get_parent(struct udev_device *udev_device)
 518 {
 519         if (udev_device == NULL)
 520                 return NULL;
 521
 522         if (udev_device->parent_device != NULL) {
 523                 info(udev_device->udev, "returning existing parent %p\n", udev_device->parent_device);
 524                 return udev_device->parent_device;
 525         }
 526         udev_device->parent_device = device_new_from_parent(udev_device);
 527         return udev_device->parent_device;
 528 }
 529
 530 struct udev_device *udev_device_get_parent_with_subsystem(struct udev_device *udev_device, const char *subsystem)
 531 {
 532         struct udev_device *parent;
 533
 534         parent = udev_device_get_parent(udev_device);
 535         while (parent != NULL) {
 536                 const char *parent_subsystem;
 537
 538                 parent_subsystem = udev_device_get_subsystem(parent);
 539                 if (parent_subsystem != NULL && strcmp(parent_subsystem, subsystem) == 0)
 540                         break;
 541                 parent = udev_device_get_parent(parent);
 542         }
 543         return parent;
 544 }
 545
 546 /**
 547  * udev_device_get_udev:
 548  * @udev_device: udev device
 549  *
 550  * Retrieve the udev library context the device was created with.
 551  *
 552  * Returns: the udev library context
 553  **/
 554 struct udev *udev_device_get_udev(struct udev_device *udev_device)
 555 {
 556         if (udev_device == NULL)
 557                 return NULL;
 558         return udev_device->udev;
 559 }
 560
 561 /**
 562  * udev_device_ref:
 563  * @udev_device: udev device
 564  *
 565  * Take a reference of a udev device.
 566  *
 567  * Returns: the passed udev device
 568  **/
 569 struct udev_device *udev_device_ref(struct udev_device *udev_device)
 570 {
 571         if (udev_device == NULL)
 572                 return NULL;
 573         udev_device->refcount++;
 574         return udev_device;
 575 }
 576
 577 /**
 578  * udev_device_unref:
 579  * @udev_device: udev device
 580  *
 581  * Drop a reference of a udev device. If the refcount reaches zero,
 582  * the ressources of the device will be released.
 583  *
 584  **/
 585 void udev_device_unref(struct udev_device *udev_device)
 586 {
 587         unsigned int i;
 588
 589         if (udev_device == NULL)
 590                 return;
 591         udev_device->refcount--;
 592         if (udev_device->refcount > 0)
 593                 return;
 594         if (udev_device->parent_device != NULL)
 595                 udev_device_unref(udev_device->parent_device);
 596         free(udev_device->syspath);
 597         free(udev_device->sysname);
 598         free(udev_device->devnode);
 599         free(udev_device->subsystem);
 600         udev_list_cleanup(udev_device->udev, &udev_device->devlinks_list);
 601         udev_list_cleanup(udev_device->udev, &udev_device->properties_list);
 602         free(udev_device->action);
 603         free(udev_device->driver);
 604         free(udev_device->devpath_old);
 605         free(udev_device->physdevpath);
 606         udev_list_cleanup(udev_device->udev, &udev_device->attr_list);
 607         for (i = 0; i < ARRAY_SIZE(udev_device->envp) && udev_device->envp[i] != NULL; i++)
 608                 free(udev_device->envp[i]);
 609         info(udev_device->udev, "udev_device: %p released\n", udev_device);
 610         free(udev_device);
 611 }
 612
 613 /**
 614  * udev_device_get_devpath:
 615  * @udev_device: udev device
 616  *
 617  * Retrieve the kernel devpath value of the udev device. The path
 618  * does not contain the sys mount point, and starts with a '/'.
 619  *
 620  * Returns: the devpath of the udev device
 621  **/
 622 const char *udev_device_get_devpath(struct udev_device *udev_device)
 623 {
 624         if (udev_device == NULL)
 625                 return NULL;
 626         return udev_device->devpath;
 627 }
 628
 629 /**
 630  * udev_device_get_syspath:
 631  * @udev_device: udev device
 632  *
 633  * Retrieve the sys path of the udev device. The path is an
 634  * absolute path and starts with the sys mount point.
 635  *
 636  * Returns: the sys path of the udev device
 637  **/
 638 const char *udev_device_get_syspath(struct udev_device *udev_device)
 639 {
 640         if (udev_device == NULL)
 641                 return NULL;
 642         return udev_device->syspath;
 643 }
 644
 645 const char *udev_device_get_sysname(struct udev_device *udev_device)
 646 {
 647         if (udev_device == NULL)
 648                 return NULL;
 649         return udev_device->sysname;
 650 }
 651
 652 const char *udev_device_get_sysnum(struct udev_device *udev_device)
 653 {
 654         if (udev_device == NULL)
 655                 return NULL;
 656         return udev_device->sysnum;
 657 }
 658
 659 /**
 660  * udev_device_get_devnode:
 661  * @udev_device: udev device
 662  *
 663  * Retrieve the device node file name belonging to the udev device.
 664  * The path is an absolute path, and starts with the device directory.
 665  *
 666  * Returns: the device node file name of the udev device, or #NULL if no device node exists
 667  **/
 668 const char *udev_device_get_devnode(struct udev_device *udev_device)
 669 {
 670         if (udev_device == NULL)
 671                 return NULL;
 672         if (!udev_device->info_loaded)
 673                 device_load_info(udev_device);
 674         return udev_device->devnode;
 675 }
 676
 677 /**
 678  * udev_device_get_subsystem:
 679  * @udev_device: udev device
 680  *
 681  * Retrieve the subsystem string of the udev device. The string does not
 682  * contain any "/".
 683  *
 684  * Returns: the subsystem name of the udev device, or #NULL if it can not be determined
 685  **/
 686 const char *udev_device_get_subsystem(struct udev_device *udev_device)
 687 {
 688         char subsystem[UTIL_NAME_SIZE];
 689
 690         if (udev_device == NULL)
 691                 return NULL;
 692         if (!udev_device->subsystem_set) {
 693                 udev_device->subsystem_set = 1;
 694                 /* read "subsytem" link */
 695                 if (util_get_sys_subsystem(udev_device->udev, udev_device->syspath, subsystem, sizeof(subsystem)) > 0) {
 696                         udev_device_set_subsystem(udev_device, subsystem);
 697                         return udev_device->subsystem;
 698                 }
 699                 /* implicit names */
 700                 if (strncmp(udev_device->devpath, "/module/", 8) == 0) {
 701                         udev_device_set_subsystem(udev_device, "module");
 702                         return udev_device->subsystem;
 703                 }
 704                 if (strstr(udev_device->devpath, "/drivers/") != NULL) {
 705                         udev_device_set_subsystem(udev_device, "drivers");
 706                         return udev_device->subsystem;
 707                 }
 708                 if (strncmp(udev_device->devpath, "/subsystem/", 11) == 0 ||
 709                     strncmp(udev_device->devpath, "/class/", 7) == 0 ||
 710                     strncmp(udev_device->devpath, "/bus/", 5) == 0) {
 711                         udev_device_set_subsystem(udev_device, "subsystem");
 712                         return udev_device->subsystem;
 713                 }
 714         }
 715         return udev_device->subsystem;
 716 }
 717
 718 /**
 719  * udev_device_get_devlinks_list_entry:
 720  * @udev_device: udev device
 721  *
 722  * Retrieve the list of device links pointing to the device file of
 723  * the udev device. The next list entry can be retrieved with
 724  * udev_list_entry_next(), which returns #NULL if no more entries exist.
 725  * The devlink path can be retrieved from the list entry by
 726  * udev_list_entry_get_name(). The path is an absolute path, and starts with
 727  * the device directory.
 728  *
 729  * Returns: the first entry of the device node link list
 730  **/
 731 struct udev_list_entry *udev_device_get_devlinks_list_entry(struct udev_device *udev_device)
 732 {
 733         if (udev_device == NULL)
 734                 return NULL;
 735         if (!udev_device->info_loaded)
 736                 device_load_info(udev_device);
 737         return udev_list_get_entry(&udev_device->devlinks_list);
 738 }
 739
 740 void udev_device_cleanup_devlinks_list(struct udev_device *udev_device)
 741 {
 742         udev_device->devlinks_uptodate = 0;
 743         udev_list_cleanup(udev_device->udev, &udev_device->devlinks_list);
 744 }
 745
 746 /**
 747  * udev_device_get_properties_list_entry:
 748  * @udev_device: udev device
 749  *
 750  * Retrieve the list of key/value device properties of the udev
 751  * device. The next list entry can be retrieved with udev_list_entry_next(),
 752  * which returns #NULL if no more entries exist. The property name
 753  * can be retrieved from the list entry by udev_list_get_name(),
 754  * the property value by udev_list_get_value().
 755  *
 756  * Returns: the first entry of the property list
 757  **/
 758 struct udev_list_entry *udev_device_get_properties_list_entry(struct udev_device *udev_device)
 759 {
 760         if (udev_device == NULL)
 761                 return NULL;
 762         if (!udev_device->info_loaded)
 763                 device_load_info(udev_device);
 764         if (!udev_device->devlinks_uptodate) {
 765                 char symlinks[UTIL_PATH_SIZE];
 766                 struct udev_list_entry *list_entry;
 767
 768                 udev_device->devlinks_uptodate = 1;
 769                 list_entry = udev_device_get_devlinks_list_entry(udev_device);
 770                 if (list_entry != NULL) {
 771                         util_strlcpy(symlinks, udev_list_entry_get_name(list_entry), sizeof(symlinks));
 772                         udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry)) {
 773                                 util_strlcat(symlinks, " ", sizeof(symlinks));
 774                                 util_strlcat(symlinks, udev_list_entry_get_name(list_entry), sizeof(symlinks));
 775                         }
 776                         udev_device_add_property(udev_device, "DEVLINKS", symlinks);
 777                 }
 778         }
 779         return udev_list_get_entry(&udev_device->properties_list);
 780 }
 781
 782 const char *udev_device_get_driver(struct udev_device *udev_device)
 783 {
 784         char driver[UTIL_NAME_SIZE];
 785
 786         if (udev_device == NULL)
 787                 return NULL;
 788         if (!udev_device->driver_set) {
 789                 udev_device->driver_set = 1;
 790                 if (util_get_sys_driver(udev_device->udev, udev_device->syspath, driver, sizeof(driver)) > 0)
 791                         udev_device->driver = strdup(driver);
 792         }
 793         return udev_device->driver;
 794 }
 795
 796 dev_t udev_device_get_devnum(struct udev_device *udev_device)
 797 {
 798         if (udev_device == NULL)
 799                 return makedev(0, 0);
 800         if (!udev_device->info_loaded)
 801                 device_load_info(udev_device);
 802         return udev_device->devnum;
 803 }
 804
 805 const char *udev_device_get_action(struct udev_device *udev_device)
 806 {
 807         if (udev_device == NULL)
 808                 return NULL;
 809         return udev_device->action;
 810 }
 811
 812 unsigned long long int udev_device_get_seqnum(struct udev_device *udev_device)
 813 {
 814         if (udev_device == NULL)
 815                 return 0;
 816         return udev_device->seqnum;
 817 }
 818
 819 const char *udev_device_get_attr_value(struct udev_device *udev_device, const char *attr)
 820 {
 821         struct udev_list_entry *list_entry;
 822         char path[UTIL_PATH_SIZE];
 823         char value[UTIL_NAME_SIZE];
 824         struct stat statbuf;
 825         int fd;
 826         ssize_t size;
 827         const char *val = NULL;
 828
 829         if (udev_device == NULL)
 830                 return NULL;
 831         if (attr == NULL)
 832                 return NULL;
 833
 834         /* look for possibly already cached result */
 835         udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_device->attr_list)) {
 836                 if (strcmp(udev_list_entry_get_name(list_entry), attr) == 0) {
 837                         info(udev_device->udev, "got '%s' (%s) from cache\n",
 838                              attr, udev_list_entry_get_value(list_entry));
 839                         return udev_list_entry_get_value(list_entry);
 840                 }
 841         }
 842
 843         util_strlcpy(path, udev_device_get_syspath(udev_device), sizeof(path));
 844         util_strlcat(path, "/", sizeof(path));
 845         util_strlcat(path, attr, sizeof(path));
 846
 847         if (lstat(path, &statbuf) != 0) {
 848                 info(udev_device->udev, "no attribute '%s', keep negative entry\n", path);
 849                 udev_list_entry_add(udev_device->udev, &udev_device->attr_list, attr, NULL, 0, 0);
 850                 goto out;
 851         }
 852
 853         if (S_ISLNK(statbuf.st_mode)) {
 854                 /* links return the last element of the target path */
 855                 char target[UTIL_NAME_SIZE];
 856                 int len;
 857                 char *pos;
 858
 859                 len = readlink(path, target, sizeof(target));
 860                 if (len > 0) {
 861                         target[len] = '\0';
 862                         pos = strrchr(target, '/');
 863                         if (pos != NULL) {
 864                                 pos = &pos[1];
 865                                 info(udev_device->udev, "cache '%s' with link value '%s'\n", attr, pos);
 866                                 list_entry = udev_list_entry_add(udev_device->udev, &udev_device->attr_list, attr, pos, 0, 0);
 867                                 val = udev_list_entry_get_value(list_entry);
 868                         }
 869                 }
 870                 goto out;
 871         }
 872
 873         /* skip directories */
 874         if (S_ISDIR(statbuf.st_mode))
 875                 goto out;
 876
 877         /* skip non-readable files */
 878         if ((statbuf.st_mode & S_IRUSR) == 0)
 879                 goto out;
 880
 881         /* read attribute value */
 882         fd = open(path, O_RDONLY);
 883         if (fd < 0) {
 884                 info(udev_device->udev, "attribute '%s' can not be opened\n", path);
 885                 goto out;
 886         }
 887         size = read(fd, value, sizeof(value));
 888         close(fd);
 889         if (size < 0)
 890                 goto out;
 891         if (size == sizeof(value))
 892                 goto out;
 893
 894         /* got a valid value, store it in cache and return it */
 895         value[size] = '\0';
 896         util_remove_trailing_chars(value, '\n');
 897         info(udev_device->udev, "'%s' has attribute value '%s'\n", path, value);
 898         list_entry = udev_list_entry_add(udev_device->udev, &udev_device->attr_list, attr, value, 0, 0);
 899         val = udev_list_entry_get_value(list_entry);
 900 out:
 901         return val;
 902 }
 903
 904 int udev_device_set_syspath(struct udev_device *udev_device, const char *syspath)
 905 {
 906         const char *pos;
 907         size_t len;
 908
 909         free(udev_device->syspath);
 910         udev_device->syspath = strdup(syspath);
 911         if (udev_device->syspath ==  NULL)
 912                 return -ENOMEM;
 913         udev_device->devpath = &udev_device->syspath[strlen(udev_get_sys_path(udev_device->udev))];
 914         udev_device_add_property(udev_device, "DEVPATH", udev_device->devpath);
 915
 916         pos = strrchr(udev_device->syspath, '/');
 917         if (pos == NULL)
 918                 return -EINVAL;
 919         udev_device->sysname = strdup(&pos[1]);
 920         if (udev_device->sysname == NULL)
 921                 return -ENOMEM;
 922
 923         /* some devices have '!' in their name, change that to '/' */
 924         len = 0;
 925         while (udev_device->sysname[len] != '\0') {
 926                 if (udev_device->sysname[len] == '!')
 927                         udev_device->sysname[len] = '/';
 928                 len++;
 929         }
 930
 931         /* trailing number */
 932         while (isdigit(udev_device->sysname[--len]))
 933                 udev_device->sysnum = &udev_device->sysname[len];
 934         return 0;
 935 }
 936
 937 int udev_device_set_subsystem(struct udev_device *udev_device, const char *subsystem)
 938 {
 939         free(udev_device->subsystem);
 940         udev_device->subsystem = strdup(subsystem);
 941         if (udev_device->subsystem == NULL)
 942                 return -ENOMEM;
 943         udev_device->subsystem_set = 1;
 944         udev_device_add_property(udev_device, "SUBSYSTEM", udev_device->subsystem);
 945         return 0;
 946 }
 947
 948 int udev_device_set_devnode(struct udev_device *udev_device, const char *devnode)
 949 {
 950         free(udev_device->devnode);
 951         udev_device->devnode = strdup(devnode);
 952         if (devnode == NULL)
 953                 return 0;
 954         if (udev_device->devnode == NULL)
 955                 return -ENOMEM;
 956         udev_device_add_property(udev_device, "DEVNAME", udev_device->devnode);
 957         return 0;
 958 }
 959
 960 int udev_device_add_devlink(struct udev_device *udev_device, const char *devlink)
 961 {
 962         udev_device->devlinks_uptodate = 0;
 963         if (udev_list_entry_add(udev_device->udev, &udev_device->devlinks_list, devlink, NULL, 1, 0) == NULL)
 964                 return -ENOMEM;
 965         return 0;
 966 }
 967
 968 struct udev_list_entry *udev_device_add_property(struct udev_device *udev_device, const char *key, const char *value)
 969 {
 970         udev_device->envp_uptodate = 0;
 971         return udev_list_entry_add(udev_device->udev, &udev_device->properties_list, key, value, 1, 0);
 972 }
 973
 974 struct udev_list_entry *udev_device_add_property_from_string(struct udev_device *udev_device, const char *property)
 975 {
 976         char name[UTIL_PATH_SIZE];
 977         char *val;
 978
 979         strncpy(name, property, sizeof(name));
 980         val = strchr(name, '=');
 981         if (val == NULL)
 982                 return NULL;
 983         val[0] = '\0';
 984         val = &val[1];
 985         if (val[0] == '\0')
 986                 val = NULL;
 987         return udev_device_add_property(udev_device, name, val);
 988 }
 989
 990 char **udev_device_get_properties_envp(struct udev_device *udev_device)
 991 {
 992         if (!udev_device->envp_uptodate) {
 993                 unsigned int i;
 994                 struct udev_list_entry *list_entry;
 995
 996                 for (i = 0; i < ARRAY_SIZE(udev_device->envp) && udev_device->envp[i] != NULL; i++)
 997                         free(udev_device->envp[i]);
 998                 i = 0;
 999                 udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) {
1000                         asprintf(&udev_device->envp[i++], "%s=%s",
1001                                  udev_list_entry_get_name(list_entry),
1002                                  udev_list_entry_get_value(list_entry));
1003                         if (i+1 >= ARRAY_SIZE(udev_device->envp))
1004                                 break;
1005                 }
1006                 udev_device->envp[i] = NULL;
1007                 info(udev_device->udev, "constructed envp from %u properties\n", i);
1008                 udev_device->envp_uptodate = 1;
1009         }
1010         return udev_device->envp;
1011 }
1012
1013 int udev_device_set_action(struct udev_device *udev_device, const char *action)
1014 {
1015         free(udev_device->action);
1016         udev_device->action = strdup(action);
1017         if (udev_device->action == NULL)
1018                 return -ENOMEM;
1019         udev_device_add_property(udev_device, "ACTION", action);
1020         return 0;
1021 }
1022
1023 int udev_device_set_driver(struct udev_device *udev_device, const char *driver)
1024 {
1025         free(udev_device->driver);
1026         udev_device->driver = strdup(driver);
1027         if (udev_device->driver == NULL)
1028                 return -ENOMEM;
1029         udev_device->driver_set = 1;
1030         return 0;
1031 }
1032
1033 const char *udev_device_get_devpath_old(struct udev_device *udev_device)
1034 {
1035         return udev_device->devpath_old;
1036 }
1037
1038 int udev_device_set_devpath_old(struct udev_device *udev_device, const char *devpath_old)
1039 {
1040         udev_device->devpath_old = strdup(devpath_old);
1041         if (udev_device->devpath_old == NULL)
1042                 return -ENOMEM;
1043         return 0;
1044 }
1045
1046 const char *udev_device_get_physdevpath(struct udev_device *udev_device)
1047 {
1048         return udev_device->physdevpath;
1049 }
1050
1051 int udev_device_set_physdevpath(struct udev_device *udev_device, const char *physdevpath)
1052 {
1053         udev_device->physdevpath = strdup(physdevpath);
1054         if (udev_device->physdevpath == NULL)
1055                 return -ENOMEM;
1056         return 0;
1057 }
1058
1059 int udev_device_get_timeout(struct udev_device *udev_device)
1060 {
1061         return udev_device->timeout;
1062 }
1063
1064 int udev_device_set_timeout(struct udev_device *udev_device, int timeout)
1065 {
1066         udev_device->timeout = timeout;
1067         return 0;
1068 }
1069 int udev_device_get_event_timeout(struct udev_device *udev_device)
1070 {
1071         if (!udev_device->info_loaded)
1072                 device_load_info(udev_device);
1073         return udev_device->event_timeout;
1074 }
1075
1076 int udev_device_set_event_timeout(struct udev_device *udev_device, int event_timeout)
1077 {
1078         udev_device->event_timeout = event_timeout;
1079         return 0;
1080 }
1081
1082 int udev_device_set_seqnum(struct udev_device *udev_device, unsigned long long int seqnum)
1083 {
1084         udev_device->seqnum = seqnum;
1085         return 0;
1086 }
1087
1088 int udev_device_set_devnum(struct udev_device *udev_device, dev_t devnum)
1089 {
1090         udev_device->devnum = devnum;
1091         return 0;
1092 }
1093
1094 int udev_device_get_num_fake_partitions(struct udev_device *udev_device)
1095 {
1096         if (!udev_device->info_loaded)
1097                 device_load_info(udev_device);
1098         return udev_device->num_fake_partitions;
1099 }
1100
1101 int udev_device_set_num_fake_partitions(struct udev_device *udev_device, int num)
1102 {
1103         udev_device->num_fake_partitions = num;
1104         return 0;
1105 }
1106
1107 int udev_device_get_devlink_priority(struct udev_device *udev_device)
1108 {
1109         if (!udev_device->info_loaded)
1110                 device_load_info(udev_device);
1111         return udev_device->devlink_priority;
1112 }
1113
1114 int udev_device_set_devlink_priority(struct udev_device *udev_device, int prio)
1115 {
1116          udev_device->devlink_priority = prio;
1117         return 0;
1118 }
1119
1120 int udev_device_get_ignore_remove(struct udev_device *udev_device)
1121 {
1122         if (!udev_device->info_loaded)
1123                 device_load_info(udev_device);
1124         return udev_device->ignore_remove;
1125 }
1126
1127 int udev_device_set_ignore_remove(struct udev_device *udev_device, int ignore)
1128 {
1129         udev_device->ignore_remove = ignore;
1130         return 0;
1131 }