src/libudev/libudev-device.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 /* Make sure the net/if.h header is included before any linux/ one */
   4 #include <net/if.h>
   5 #include <ctype.h>
   6 #include <dirent.h>
   7 #include <errno.h>
   8 #include <fcntl.h>
   9 #include <linux/sockios.h>
  10 #include <stdbool.h>
  11 #include <stddef.h>
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <string.h>
  15 #include <sys/ioctl.h>
  16 #include <sys/socket.h>
  17 #include <sys/stat.h>
  18 #include <unistd.h>
  19
  20 #include "libudev.h"
  21 #include "sd-device.h"
  22
  23 #include "alloc-util.h"
  24 #include "device-private.h"
  25 #include "device-util.h"
  26 #include "libudev-device-internal.h"
  27 #include "libudev-list-internal.h"
  28 #include "parse-util.h"
  29 #include "time-util.h"
  30
  31 /**
  32  * SECTION:libudev-device
  33  * @short_description: kernel sys devices
  34  *
  35  * Representation of kernel sys devices. Devices are uniquely identified
  36  * by their syspath, every device has exactly one path in the kernel sys
  37  * filesystem. Devices usually belong to a kernel subsystem, and have
  38  * a unique name inside that subsystem.
  39  */
  40
  41 /**
  42  * udev_device:
  43  *
  44  * Opaque object representing one kernel sys device.
  45  */
  46 struct udev_device {
  47         struct udev *udev;
  48
  49         /* real device object */
  50         sd_device *device;
  51
  52         /* legacy */
  53         unsigned n_ref;
  54
  55         struct udev_device *parent;
  56         bool parent_set;
  57
  58         struct udev_list *properties;
  59         uint64_t properties_generation;
  60         struct udev_list *all_tags, *current_tags;
  61         uint64_t all_tags_generation, current_tags_generation;
  62         struct udev_list *devlinks;
  63         uint64_t devlinks_generation;
  64         bool properties_read:1;
  65         bool all_tags_read:1;
  66         bool current_tags_read:1;
  67         bool devlinks_read:1;
  68         struct udev_list *sysattrs;
  69         bool sysattrs_read;
  70 };
  71
  72 /**
  73  * udev_device_get_seqnum:
  74  * @udev_device: udev device
  75  *
  76  * This is only valid if the device was received through a monitor. Devices read from
  77  * sys do not have a sequence number.
  78  *
  79  * Returns: the kernel event sequence number, or 0 if there is no sequence number available.
  80  **/
  81 _public_ unsigned long long udev_device_get_seqnum(struct udev_device *udev_device) {
  82         uint64_t seqnum;
  83
  84         assert_return_errno(udev_device, 0, EINVAL);
  85
  86         if (sd_device_get_seqnum(udev_device->device, &seqnum) < 0)
  87                 return 0;
  88
  89         return seqnum;
  90 }
  91
  92 /**
  93  * udev_device_get_devnum:
  94  * @udev_device: udev device
  95  *
  96  * Get the device major/minor number.
  97  *
  98  * Returns: the dev_t number.
  99  **/
 100 _public_ dev_t udev_device_get_devnum(struct udev_device *udev_device) {
 101         dev_t devnum;
 102         int r;
 103
 104         assert_return_errno(udev_device, makedev(0, 0), EINVAL);
 105
 106         r = sd_device_get_devnum(udev_device->device, &devnum);
 107         if (r == -ENOENT)
 108                 return makedev(0, 0);
 109         if (r < 0)
 110                 return_with_errno(makedev(0, 0), r);
 111
 112         return devnum;
 113 }
 114
 115 /**
 116  * udev_device_get_driver:
 117  * @udev_device: udev device
 118  *
 119  * Get the kernel driver name.
 120  *
 121  * Returns: the driver name string, or #NULL if there is no driver attached.
 122  **/
 123 _public_ const char *udev_device_get_driver(struct udev_device *udev_device) {
 124         const char *driver;
 125         int r;
 126
 127         assert_return_errno(udev_device, NULL, EINVAL);
 128
 129         r = sd_device_get_driver(udev_device->device, &driver);
 130         if (r < 0)
 131                 return_with_errno(NULL, r);
 132
 133         return driver;
 134 }
 135
 136 /**
 137  * udev_device_get_devtype:
 138  * @udev_device: udev device
 139  *
 140  * Retrieve the devtype string of the udev device.
 141  *
 142  * Returns: the devtype name of the udev device, or #NULL if it cannot be determined
 143  **/
 144 _public_ const char *udev_device_get_devtype(struct udev_device *udev_device) {
 145         const char *devtype;
 146         int r;
 147
 148         assert_return_errno(udev_device, NULL, EINVAL);
 149
 150         r = sd_device_get_devtype(udev_device->device, &devtype);
 151         if (r == -ENOENT)
 152                 return NULL;
 153         if (r < 0)
 154                 return_with_errno(NULL, r);
 155
 156         return devtype;
 157 }
 158
 159 /**
 160  * udev_device_get_subsystem:
 161  * @udev_device: udev device
 162  *
 163  * Retrieve the subsystem string of the udev device. The string does not
 164  * contain any "/".
 165  *
 166  * Returns: the subsystem name of the udev device, or #NULL if it cannot be determined
 167  **/
 168 _public_ const char *udev_device_get_subsystem(struct udev_device *udev_device) {
 169         const char *subsystem;
 170         int r;
 171
 172         assert_return_errno(udev_device, NULL, EINVAL);
 173
 174         r = sd_device_get_subsystem(udev_device->device, &subsystem);
 175         if (r < 0)
 176                 return_with_errno(NULL, r);
 177
 178         return subsystem;
 179 }
 180
 181 /**
 182  * udev_device_get_property_value:
 183  * @udev_device: udev device
 184  * @key: property name
 185  *
 186  * Get the value of a given property.
 187  *
 188  * Returns: the property string, or #NULL if there is no such property.
 189  **/
 190 _public_ const char *udev_device_get_property_value(struct udev_device *udev_device, const char *key) {
 191         const char *value;
 192         int r;
 193
 194         assert_return_errno(udev_device && key, NULL, EINVAL);
 195
 196         r = sd_device_get_property_value(udev_device->device, key, &value);
 197         if (r < 0)
 198                 return_with_errno(NULL, r);
 199
 200         return value;
 201 }
 202
 203 struct udev_device *udev_device_new(struct udev *udev, sd_device *device) {
 204         _cleanup_(udev_list_freep) struct udev_list *properties = NULL, *all_tags = NULL, *current_tags = NULL, *sysattrs = NULL, *devlinks = NULL;
 205         struct udev_device *udev_device;
 206
 207         assert(device);
 208
 209         properties = udev_list_new(true);
 210         if (!properties)
 211                 return_with_errno(NULL, ENOMEM);
 212         all_tags = udev_list_new(true);
 213         if (!all_tags)
 214                 return_with_errno(NULL, ENOMEM);
 215         current_tags = udev_list_new(true);
 216         if (!current_tags)
 217                 return_with_errno(NULL, ENOMEM);
 218         sysattrs = udev_list_new(true);
 219         if (!sysattrs)
 220                 return_with_errno(NULL, ENOMEM);
 221         devlinks = udev_list_new(true);
 222         if (!devlinks)
 223                 return_with_errno(NULL, ENOMEM);
 224
 225         udev_device = new(struct udev_device, 1);
 226         if (!udev_device)
 227                 return_with_errno(NULL, ENOMEM);
 228
 229         *udev_device = (struct udev_device) {
 230                 .n_ref = 1,
 231                 .udev = udev,
 232                 .device = sd_device_ref(device),
 233                 .properties = TAKE_PTR(properties),
 234                 .all_tags = TAKE_PTR(all_tags),
 235                 .current_tags = TAKE_PTR(current_tags),
 236                 .sysattrs = TAKE_PTR(sysattrs),
 237                 .devlinks = TAKE_PTR(devlinks),
 238         };
 239
 240         return udev_device;
 241 }
 242
 243 /**
 244  * udev_device_new_from_syspath:
 245  * @udev: udev library context
 246  * @syspath: sys device path including sys directory
 247  *
 248  * Create new udev device, and fill in information from the sys
 249  * device and the udev database entry. The syspath is the absolute
 250  * path to the device, including the sys mount point.
 251  *
 252  * The initial refcount is 1, and needs to be decremented to
 253  * release the resources of the udev device.
 254  *
 255  * Returns: a new udev device, or #NULL, if it does not exist
 256  **/
 257 _public_ struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *syspath) {
 258         _cleanup_(sd_device_unrefp) sd_device *device = NULL;
 259         int r;
 260
 261         r = sd_device_new_from_syspath(&device, syspath);
 262         if (r < 0)
 263                 return_with_errno(NULL, r);
 264
 265         return udev_device_new(udev, device);
 266 }
 267
 268 /**
 269  * udev_device_new_from_devnum:
 270  * @udev: udev library context
 271  * @type: char or block device
 272  * @devnum: device major/minor number
 273  *
 274  * Create new udev device, and fill in information from the sys
 275  * device and the udev database entry. The device is looked-up
 276  * by its major/minor number and type. Character and block device
 277  * numbers are not unique across the two types.
 278  *
 279  * The initial refcount is 1, and needs to be decremented to
 280  * release the resources of the udev device.
 281  *
 282  * Returns: a new udev device, or #NULL, if it does not exist
 283  **/
 284 _public_ struct udev_device *udev_device_new_from_devnum(struct udev *udev, char type, dev_t devnum) {
 285         _cleanup_(sd_device_unrefp) sd_device *device = NULL;
 286         int r;
 287
 288         r = sd_device_new_from_devnum(&device, type, devnum);
 289         if (r < 0)
 290                 return_with_errno(NULL, r);
 291
 292         return udev_device_new(udev, device);
 293 }
 294
 295 /**
 296  * udev_device_new_from_device_id:
 297  * @udev: udev library context
 298  * @id: text string identifying a kernel device
 299  *
 300  * Create new udev device, and fill in information from the sys
 301  * device and the udev database entry. The device is looked-up
 302  * by a special string:
 303  *   b8:2          - block device major:minor
 304  *   c128:1        - char device major:minor
 305  *   n3            - network device ifindex
 306  *   +sound:card29 - kernel driver core subsystem:device name
 307  *
 308  * The initial refcount is 1, and needs to be decremented to
 309  * release the resources of the udev device.
 310  *
 311  * Returns: a new udev device, or #NULL, if it does not exist
 312  **/
 313 _public_ struct udev_device *udev_device_new_from_device_id(struct udev *udev, const char *id) {
 314         _cleanup_(sd_device_unrefp) sd_device *device = NULL;
 315         int r;
 316
 317         r = sd_device_new_from_device_id(&device, id);
 318         if (r < 0)
 319                 return_with_errno(NULL, r);
 320
 321         return udev_device_new(udev, device);
 322 }
 323
 324 /**
 325  * udev_device_new_from_subsystem_sysname:
 326  * @udev: udev library context
 327  * @subsystem: the subsystem of the device
 328  * @sysname: the name of the device
 329  *
 330  * Create new udev device, and fill in information from the sys device
 331  * and the udev database entry. The device is looked up by the subsystem
 332  * and name string of the device, like "mem" / "zero", or "block" / "sda".
 333  *
 334  * The initial refcount is 1, and needs to be decremented to
 335  * release the resources of the udev device.
 336  *
 337  * Returns: a new udev device, or #NULL, if it does not exist
 338  **/
 339 _public_ struct udev_device *udev_device_new_from_subsystem_sysname(struct udev *udev, const char *subsystem, const char *sysname) {
 340         _cleanup_(sd_device_unrefp) sd_device *device = NULL;
 341         int r;
 342
 343         r = sd_device_new_from_subsystem_sysname(&device, subsystem, sysname);
 344         if (r < 0)
 345                 return_with_errno(NULL, r);
 346
 347         return udev_device_new(udev, device);
 348 }
 349
 350 /**
 351  * udev_device_new_from_environment
 352  * @udev: udev library context
 353  *
 354  * Create new udev device, and fill in information from the
 355  * current process environment. This only works reliably if
 356  * the process is called from a udev rule. It is usually used
 357  * for tools executed from IMPORT= rules.
 358  *
 359  * The initial refcount is 1, and needs to be decremented to
 360  * release the resources of the udev device.
 361  *
 362  * Returns: a new udev device, or #NULL, if it does not exist
 363  **/
 364 _public_ struct udev_device *udev_device_new_from_environment(struct udev *udev) {
 365         _cleanup_(sd_device_unrefp) sd_device *device = NULL;
 366         int r;
 367
 368         r = device_new_from_strv(&device, environ);
 369         if (r < 0)
 370                 return_with_errno(NULL, r);
 371
 372         return udev_device_new(udev, device);
 373 }
 374
 375 static struct udev_device *device_new_from_parent(struct udev_device *child) {
 376         sd_device *parent;
 377         int r;
 378
 379         assert_return_errno(child, NULL, EINVAL);
 380
 381         r = sd_device_get_parent(child->device, &parent);
 382         if (r < 0)
 383                 return_with_errno(NULL, r);
 384
 385         return udev_device_new(child->udev, parent);
 386 }
 387
 388 /**
 389  * udev_device_get_parent:
 390  * @udev_device: the device to start searching from
 391  *
 392  * Find the next parent device, and fill in information from the sys
 393  * device and the udev database entry.
 394  *
 395  * Returned device is not referenced. It is attached to the child
 396  * device, and will be cleaned up when the child device is cleaned up.
 397  *
 398  * It is not necessarily just the upper level directory, empty or not
 399  * recognized sys directories are ignored.
 400  *
 401  * It can be called as many times as needed, without caring about
 402  * references.
 403  *
 404  * Returns: a new udev device, or #NULL, if it no parent exist.
 405  **/
 406 _public_ struct udev_device *udev_device_get_parent(struct udev_device *udev_device) {
 407         assert_return_errno(udev_device, NULL, EINVAL);
 408
 409         if (!udev_device->parent_set) {
 410                 udev_device->parent_set = true;
 411                 udev_device->parent = device_new_from_parent(udev_device);
 412         }
 413
 414         /* TODO: errno will differ here in case parent == NULL */
 415         return udev_device->parent;
 416 }
 417
 418 /**
 419  * udev_device_get_parent_with_subsystem_devtype:
 420  * @udev_device: udev device to start searching from
 421  * @subsystem: the subsystem of the device
 422  * @devtype: the type (DEVTYPE) of the device
 423  *
 424  * Find the next parent device, with a matching subsystem and devtype
 425  * value, and fill in information from the sys device and the udev
 426  * database entry.
 427  *
 428  * If devtype is #NULL, only subsystem is checked, and any devtype will
 429  * match.
 430  *
 431  * Returned device is not referenced. It is attached to the child
 432  * device, and will be cleaned up when the child device is cleaned up.
 433  *
 434  * It can be called as many times as needed, without caring about
 435  * references.
 436  *
 437  * Returns: a new udev device, or #NULL if no matching parent exists.
 438  **/
 439 _public_ struct udev_device *udev_device_get_parent_with_subsystem_devtype(struct udev_device *udev_device, const char *subsystem, const char *devtype) {
 440         sd_device *parent;
 441         int r;
 442
 443         assert_return_errno(udev_device, NULL, EINVAL);
 444
 445         /* this relies on the fact that finding the subdevice of a parent or the
 446            parent of a subdevice commute */
 447
 448         /* first find the correct sd_device */
 449         r = sd_device_get_parent_with_subsystem_devtype(udev_device->device, subsystem, devtype, &parent);
 450         if (r < 0)
 451                 return_with_errno(NULL, r);
 452
 453         /* then walk the chain of udev_device parents until the corresponding
 454            one is found */
 455         while ((udev_device = udev_device_get_parent(udev_device)))
 456                 if (udev_device->device == parent)
 457                         return udev_device;
 458
 459         return_with_errno(NULL, ENOENT);
 460 }
 461
 462 /**
 463  * udev_device_get_udev:
 464  * @udev_device: udev device
 465  *
 466  * Retrieve the udev library context the device was created with.
 467  *
 468  * Returns: the udev library context
 469  **/
 470 _public_ struct udev *udev_device_get_udev(struct udev_device *udev_device) {
 471         assert_return_errno(udev_device, NULL, EINVAL);
 472
 473         return udev_device->udev;
 474 }
 475
 476 static struct udev_device *udev_device_free(struct udev_device *udev_device) {
 477         assert(udev_device);
 478
 479         sd_device_unref(udev_device->device);
 480         udev_device_unref(udev_device->parent);
 481
 482         udev_list_free(udev_device->properties);
 483         udev_list_free(udev_device->sysattrs);
 484         udev_list_free(udev_device->all_tags);
 485         udev_list_free(udev_device->current_tags);
 486         udev_list_free(udev_device->devlinks);
 487
 488         return mfree(udev_device);
 489 }
 490
 491 /**
 492  * udev_device_ref:
 493  * @udev_device: udev device
 494  *
 495  * Take a reference of a udev device.
 496  *
 497  * Returns: the passed udev device
 498  **/
 499
 500 /**
 501  * udev_device_unref:
 502  * @udev_device: udev device
 503  *
 504  * Drop a reference of a udev device. If the refcount reaches zero,
 505  * the resources of the device will be released.
 506  *
 507  * Returns: #NULL
 508  **/
 509 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(struct udev_device, udev_device, udev_device_free);
 510
 511 /**
 512  * udev_device_get_devpath:
 513  * @udev_device: udev device
 514  *
 515  * Retrieve the kernel devpath value of the udev device. The path
 516  * does not contain the sys mount point, and starts with a '/'.
 517  *
 518  * Returns: the devpath of the udev device
 519  **/
 520 _public_ const char *udev_device_get_devpath(struct udev_device *udev_device) {
 521         const char *devpath;
 522         int r;
 523
 524         assert_return_errno(udev_device, NULL, EINVAL);
 525
 526         r = sd_device_get_devpath(udev_device->device, &devpath);
 527         if (r < 0)
 528                 return_with_errno(NULL, r);
 529
 530         return devpath;
 531 }
 532
 533 /**
 534  * udev_device_get_syspath:
 535  * @udev_device: udev device
 536  *
 537  * Retrieve the sys path of the udev device. The path is an
 538  * absolute path and starts with the sys mount point.
 539  *
 540  * Returns: the sys path of the udev device
 541  **/
 542 _public_ const char *udev_device_get_syspath(struct udev_device *udev_device) {
 543         const char *syspath;
 544         int r;
 545
 546         assert_return_errno(udev_device, NULL, EINVAL);
 547
 548         r = sd_device_get_syspath(udev_device->device, &syspath);
 549         if (r < 0)
 550                 return_with_errno(NULL, r);
 551
 552         return syspath;
 553 }
 554
 555 /**
 556  * udev_device_get_sysname:
 557  * @udev_device: udev device
 558  *
 559  * Get the kernel device name in /sys.
 560  *
 561  * Returns: the name string of the device
 562  **/
 563 _public_ const char *udev_device_get_sysname(struct udev_device *udev_device) {
 564         const char *sysname;
 565         int r;
 566
 567         assert_return_errno(udev_device, NULL, EINVAL);
 568
 569         r = sd_device_get_sysname(udev_device->device, &sysname);
 570         if (r < 0)
 571                 return_with_errno(NULL, r);
 572
 573         return sysname;
 574 }
 575
 576 /**
 577  * udev_device_get_sysnum:
 578  * @udev_device: udev device
 579  *
 580  * Get the instance number of the device.
 581  *
 582  * Returns: the trailing number string of the device name
 583  **/
 584 _public_ const char *udev_device_get_sysnum(struct udev_device *udev_device) {
 585         const char *sysnum;
 586         int r;
 587
 588         assert_return_errno(udev_device, NULL, EINVAL);
 589
 590         r = sd_device_get_sysnum(udev_device->device, &sysnum);
 591         if (r == -ENOENT)
 592                 return NULL;
 593         if (r < 0)
 594                 return_with_errno(NULL, r);
 595
 596         return sysnum;
 597 }
 598
 599 /**
 600  * udev_device_get_devnode:
 601  * @udev_device: udev device
 602  *
 603  * Retrieve the device node file name belonging to the udev device.
 604  * The path is an absolute path, and starts with the device directory.
 605  *
 606  * Returns: the device node file name of the udev device, or #NULL if no device node exists
 607  **/
 608 _public_ const char *udev_device_get_devnode(struct udev_device *udev_device) {
 609         const char *devnode;
 610         int r;
 611
 612         assert_return_errno(udev_device, NULL, EINVAL);
 613
 614         r = sd_device_get_devname(udev_device->device, &devnode);
 615         if (r < 0)
 616                 return_with_errno(NULL, r);
 617
 618         return devnode;
 619 }
 620
 621 /**
 622  * udev_device_get_devlinks_list_entry:
 623  * @udev_device: udev device
 624  *
 625  * Retrieve the list of device links pointing to the device file of
 626  * the udev device. The next list entry can be retrieved with
 627  * udev_list_entry_get_next(), which returns #NULL if no more entries exist.
 628  * The devlink path can be retrieved from the list entry by
 629  * udev_list_entry_get_name(). The path is an absolute path, and starts with
 630  * the device directory.
 631  *
 632  * Returns: the first entry of the device node link list
 633  **/
 634 _public_ struct udev_list_entry *udev_device_get_devlinks_list_entry(struct udev_device *udev_device) {
 635         assert_return_errno(udev_device, NULL, EINVAL);
 636
 637         if (device_get_devlinks_generation(udev_device->device) != udev_device->devlinks_generation ||
 638             !udev_device->devlinks_read) {
 639                 udev_list_cleanup(udev_device->devlinks);
 640
 641                 FOREACH_DEVICE_DEVLINK(udev_device->device, devlink)
 642                         if (!udev_list_entry_add(udev_device->devlinks, devlink, NULL))
 643                                 return_with_errno(NULL, ENOMEM);
 644
 645                 udev_device->devlinks_read = true;
 646                 udev_device->devlinks_generation = device_get_devlinks_generation(udev_device->device);
 647         }
 648
 649         return udev_list_get_entry(udev_device->devlinks);
 650 }
 651
 652 /**
 653  * udev_device_get_event_properties_entry:
 654  * @udev_device: udev device
 655  *
 656  * Retrieve the list of key/value device properties of the udev
 657  * device. The next list entry can be retrieved with udev_list_entry_get_next(),
 658  * which returns #NULL if no more entries exist. The property name
 659  * can be retrieved from the list entry by udev_list_entry_get_name(),
 660  * the property value by udev_list_entry_get_value().
 661  *
 662  * Returns: the first entry of the property list
 663  **/
 664 _public_ struct udev_list_entry *udev_device_get_properties_list_entry(struct udev_device *udev_device) {
 665         assert_return_errno(udev_device, NULL, EINVAL);
 666
 667         if (device_get_properties_generation(udev_device->device) != udev_device->properties_generation ||
 668             !udev_device->properties_read) {
 669                 udev_list_cleanup(udev_device->properties);
 670
 671                 FOREACH_DEVICE_PROPERTY(udev_device->device, key, value)
 672                         if (!udev_list_entry_add(udev_device->properties, key, value))
 673                                 return_with_errno(NULL, ENOMEM);
 674
 675                 udev_device->properties_read = true;
 676                 udev_device->properties_generation = device_get_properties_generation(udev_device->device);
 677         }
 678
 679         return udev_list_get_entry(udev_device->properties);
 680 }
 681
 682 /**
 683  * udev_device_get_action:
 684  * @udev_device: udev device
 685  *
 686  * This is only valid if the device was received through a monitor. Devices read from
 687  * sys do not have an action string. Usual actions are: add, remove, change, move,
 688  * online, offline.
 689  *
 690  * Returns: the kernel action value, or #NULL if there is no action value available.
 691  **/
 692 _public_ const char *udev_device_get_action(struct udev_device *udev_device) {
 693         sd_device_action_t action;
 694
 695         assert_return_errno(udev_device, NULL, EINVAL);
 696
 697         if (sd_device_get_action(udev_device->device, &action) < 0)
 698                 return NULL;
 699
 700         return device_action_to_string(action);
 701 }
 702
 703 /**
 704  * udev_device_get_usec_since_initialized:
 705  * @udev_device: udev device
 706  *
 707  * Return the number of microseconds passed since udev set up the
 708  * device for the first time.
 709  *
 710  * This is only implemented for devices with need to store properties
 711  * in the udev database. All other devices return 0 here.
 712  *
 713  * Returns: the number of microseconds since the device was first seen.
 714  **/
 715 _public_ unsigned long long int udev_device_get_usec_since_initialized(struct udev_device *udev_device) {
 716         usec_t ts;
 717         int r;
 718
 719         assert_return(udev_device, -EINVAL);
 720
 721         r = sd_device_get_usec_since_initialized(udev_device->device, &ts);
 722         if (r < 0)
 723                 return_with_errno(0, r);
 724
 725         return ts;
 726 }
 727
 728 /**
 729  * udev_device_get_sysattr_value:
 730  * @udev_device: udev device
 731  * @sysattr: attribute name
 732  *
 733  * The retrieved value is cached in the device. Repeated calls will return the same
 734  * value and not open the attribute again.
 735  *
 736  * Returns: the content of a sys attribute file, or #NULL if there is no sys attribute value.
 737  **/
 738 _public_ const char *udev_device_get_sysattr_value(struct udev_device *udev_device, const char *sysattr) {
 739         const char *value;
 740         int r;
 741
 742         assert_return_errno(udev_device, NULL, EINVAL);
 743
 744         r = sd_device_get_sysattr_value(udev_device->device, sysattr, &value);
 745         if (r < 0)
 746                 return_with_errno(NULL, r);
 747
 748         return value;
 749 }
 750
 751 /**
 752  * udev_device_set_sysattr_value:
 753  * @udev_device: udev device
 754  * @sysattr: attribute name
 755  * @value: new value to be set
 756  *
 757  * Update the contents of the sys attribute and the cached value of the device.
 758  *
 759  * Returns: Negative error code on failure or 0 on success.
 760  **/
 761 _public_ int udev_device_set_sysattr_value(struct udev_device *udev_device, const char *sysattr, const char *value) {
 762         int r;
 763
 764         assert_return(udev_device, -EINVAL);
 765
 766         r = sd_device_set_sysattr_value(udev_device->device, sysattr, value);
 767         if (r < 0)
 768                 return r;
 769
 770         return 0;
 771 }
 772
 773 /**
 774  * udev_device_get_sysattr_list_entry:
 775  * @udev_device: udev device
 776  *
 777  * Retrieve the list of available sysattrs, with value being empty;
 778  * This just return all available sysfs attributes for a particular
 779  * device without reading their values.
 780  *
 781  * Returns: the first entry of the property list
 782  **/
 783 _public_ struct udev_list_entry *udev_device_get_sysattr_list_entry(struct udev_device *udev_device) {
 784         assert_return_errno(udev_device, NULL, EINVAL);
 785
 786         if (!udev_device->sysattrs_read) {
 787                 udev_list_cleanup(udev_device->sysattrs);
 788
 789                 FOREACH_DEVICE_SYSATTR(udev_device->device, sysattr)
 790                         if (!udev_list_entry_add(udev_device->sysattrs, sysattr, NULL))
 791                                 return_with_errno(NULL, ENOMEM);
 792
 793                 udev_device->sysattrs_read = true;
 794         }
 795
 796         return udev_list_get_entry(udev_device->sysattrs);
 797 }
 798
 799 /**
 800  * udev_device_get_is_initialized:
 801  * @udev_device: udev device
 802  *
 803  * Check if udev has already handled the device and has set up
 804  * device node permissions and context, or has renamed a network
 805  * device.
 806  *
 807  * This is only implemented for devices with a device node
 808  * or network interfaces. All other devices return 1 here.
 809  *
 810  * Returns: 1 if the device is set up. 0 otherwise.
 811  **/
 812 _public_ int udev_device_get_is_initialized(struct udev_device *udev_device) {
 813         int r;
 814
 815         assert_return(udev_device, -EINVAL);
 816
 817         r = sd_device_get_is_initialized(udev_device->device);
 818         if (r < 0)
 819                 return_with_errno(0, r);
 820
 821         return r;
 822 }
 823
 824 /**
 825  * udev_device_get_tags_list_entry:
 826  * @udev_device: udev device
 827  *
 828  * Retrieve the list of tags attached to the udev device. The next
 829  * list entry can be retrieved with udev_list_entry_get_next(),
 830  * which returns #NULL if no more entries exist. The tag string
 831  * can be retrieved from the list entry by udev_list_entry_get_name().
 832  *
 833  * Returns: the first entry of the tag list
 834  **/
 835 _public_ struct udev_list_entry *udev_device_get_tags_list_entry(struct udev_device *udev_device) {
 836         assert_return_errno(udev_device, NULL, EINVAL);
 837
 838         if (device_get_tags_generation(udev_device->device) != udev_device->all_tags_generation ||
 839             !udev_device->all_tags_read) {
 840                 udev_list_cleanup(udev_device->all_tags);
 841
 842                 FOREACH_DEVICE_TAG(udev_device->device, tag)
 843                         if (!udev_list_entry_add(udev_device->all_tags, tag, NULL))
 844                                 return_with_errno(NULL, ENOMEM);
 845
 846                 udev_device->all_tags_read = true;
 847                 udev_device->all_tags_generation = device_get_tags_generation(udev_device->device);
 848         }
 849
 850         return udev_list_get_entry(udev_device->all_tags);
 851 }
 852
 853 _public_ struct udev_list_entry *udev_device_get_current_tags_list_entry(struct udev_device *udev_device) {
 854         assert_return_errno(udev_device, NULL, EINVAL);
 855
 856         if (device_get_tags_generation(udev_device->device) != udev_device->current_tags_generation ||
 857             !udev_device->current_tags_read) {
 858                 udev_list_cleanup(udev_device->current_tags);
 859
 860                 FOREACH_DEVICE_CURRENT_TAG(udev_device->device, tag)
 861                         if (!udev_list_entry_add(udev_device->current_tags, tag, NULL))
 862                                 return_with_errno(NULL, ENOMEM);
 863
 864                 udev_device->current_tags_read = true;
 865                 udev_device->current_tags_generation = device_get_tags_generation(udev_device->device);
 866         }
 867
 868         return udev_list_get_entry(udev_device->current_tags);
 869 }
 870
 871 /**
 872  * udev_device_has_tag:
 873  * @udev_device: udev device
 874  * @tag: tag name
 875  *
 876  * Check if a given device has a certain tag associated.
 877  *
 878  * Returns: 1 if the tag is found. 0 otherwise.
 879  **/
 880 _public_ int udev_device_has_tag(struct udev_device *udev_device, const char *tag) {
 881         assert_return(udev_device, 0);
 882
 883         return sd_device_has_tag(udev_device->device, tag) > 0;
 884 }
 885
 886 _public_ int udev_device_has_current_tag(struct udev_device *udev_device, const char *tag) {
 887         assert_return(udev_device, 0);
 888
 889         return sd_device_has_current_tag(udev_device->device, tag) > 0;
 890 }
 891
 892 sd_device *udev_device_get_sd_device(struct udev_device *udev_device) {
 893         assert(udev_device);
 894
 895         return udev_device->device;
 896 }