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