src/libsystemd/sd-device/device-private.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <ctype.h>
   4 #include <net/if.h>
   5 #include <sys/types.h>
   6
   7 #include "sd-device.h"
   8
   9 #include "alloc-util.h"
  10 #include "device-internal.h"
  11 #include "device-private.h"
  12 #include "device-util.h"
  13 #include "fd-util.h"
  14 #include "fileio.h"
  15 #include "fs-util.h"
  16 #include "hashmap.h"
  17 #include "macro.h"
  18 #include "mkdir.h"
  19 #include "parse-util.h"
  20 #include "path-util.h"
  21 #include "set.h"
  22 #include "string-table.h"
  23 #include "string-util.h"
  24 #include "strv.h"
  25 #include "strxcpyx.h"
  26 #include "tmpfile-util.h"
  27 #include "user-util.h"
  28 #include "util.h"
  29
  30 int device_add_property(sd_device *device, const char *key, const char *value) {
  31         int r;
  32
  33         assert(device);
  34         assert(key);
  35
  36         r = device_add_property_aux(device, key, value, false);
  37         if (r < 0)
  38                 return r;
  39
  40         if (key[0] != '.') {
  41                 r = device_add_property_aux(device, key, value, true);
  42                 if (r < 0)
  43                         return r;
  44         }
  45
  46         return 0;
  47 }
  48
  49 void device_set_devlink_priority(sd_device *device, int priority) {
  50         assert(device);
  51
  52         device->devlink_priority = priority;
  53 }
  54
  55 void device_set_is_initialized(sd_device *device) {
  56         assert(device);
  57
  58         device->is_initialized = true;
  59 }
  60
  61 int device_ensure_usec_initialized(sd_device *device, sd_device *device_old) {
  62         usec_t when;
  63
  64         assert(device);
  65
  66         if (device_old && device_old->usec_initialized > 0)
  67                 when = device_old->usec_initialized;
  68         else
  69                 when = now(CLOCK_MONOTONIC);
  70
  71         return device_set_usec_initialized(device, when);
  72 }
  73
  74 uint64_t device_get_properties_generation(sd_device *device) {
  75         assert(device);
  76
  77         return device->properties_generation;
  78 }
  79
  80 uint64_t device_get_tags_generation(sd_device *device) {
  81         assert(device);
  82
  83         return device->tags_generation;
  84 }
  85
  86 uint64_t device_get_devlinks_generation(sd_device *device) {
  87         assert(device);
  88
  89         return device->devlinks_generation;
  90 }
  91
  92 int device_get_devnode_mode(sd_device *device, mode_t *mode) {
  93         int r;
  94
  95         assert(device);
  96
  97         r = device_read_db(device);
  98         if (r < 0)
  99                 return r;
 100
 101         if (device->devmode == (mode_t) -1)
 102                 return -ENOENT;
 103
 104         if (mode)
 105                 *mode = device->devmode;
 106
 107         return 0;
 108 }
 109
 110 int device_get_devnode_uid(sd_device *device, uid_t *uid) {
 111         int r;
 112
 113         assert(device);
 114
 115         r = device_read_db(device);
 116         if (r < 0)
 117                 return r;
 118
 119         if (device->devuid == (uid_t) -1)
 120                 return -ENOENT;
 121
 122         if (uid)
 123                 *uid = device->devuid;
 124
 125         return 0;
 126 }
 127
 128 static int device_set_devuid(sd_device *device, const char *uid) {
 129         unsigned u;
 130         int r;
 131
 132         assert(device);
 133         assert(uid);
 134
 135         r = safe_atou(uid, &u);
 136         if (r < 0)
 137                 return r;
 138
 139         r = device_add_property_internal(device, "DEVUID", uid);
 140         if (r < 0)
 141                 return r;
 142
 143         device->devuid = u;
 144
 145         return 0;
 146 }
 147
 148 int device_get_devnode_gid(sd_device *device, gid_t *gid) {
 149         int r;
 150
 151         assert(device);
 152
 153         r = device_read_db(device);
 154         if (r < 0)
 155                 return r;
 156
 157         if (device->devgid == (gid_t) -1)
 158                 return -ENOENT;
 159
 160         if (gid)
 161                 *gid = device->devgid;
 162
 163         return 0;
 164 }
 165
 166 static int device_set_devgid(sd_device *device, const char *gid) {
 167         unsigned g;
 168         int r;
 169
 170         assert(device);
 171         assert(gid);
 172
 173         r = safe_atou(gid, &g);
 174         if (r < 0)
 175                 return r;
 176
 177         r = device_add_property_internal(device, "DEVGID", gid);
 178         if (r < 0)
 179                 return r;
 180
 181         device->devgid = g;
 182
 183         return 0;
 184 }
 185
 186 static int device_amend(sd_device *device, const char *key, const char *value) {
 187         int r;
 188
 189         assert(device);
 190         assert(key);
 191         assert(value);
 192
 193         if (streq(key, "DEVPATH")) {
 194                 char *path;
 195
 196                 path = strjoina("/sys", value);
 197
 198                 /* the caller must verify or trust this data (e.g., if it comes from the kernel) */
 199                 r = device_set_syspath(device, path, false);
 200                 if (r < 0)
 201                         return log_device_debug_errno(device, r, "sd-device: Failed to set syspath to '%s': %m", path);
 202         } else if (streq(key, "SUBSYSTEM")) {
 203                 r = device_set_subsystem(device, value);
 204                 if (r < 0)
 205                         return log_device_debug_errno(device, r, "sd-device: Failed to set subsystem to '%s': %m", value);
 206         } else if (streq(key, "DEVTYPE")) {
 207                 r = device_set_devtype(device, value);
 208                 if (r < 0)
 209                         return log_device_debug_errno(device, r, "sd-device: Failed to set devtype to '%s': %m", value);
 210         } else if (streq(key, "DEVNAME")) {
 211                 r = device_set_devname(device, value);
 212                 if (r < 0)
 213                         return log_device_debug_errno(device, r, "sd-device: Failed to set devname to '%s': %m", value);
 214         } else if (streq(key, "USEC_INITIALIZED")) {
 215                 usec_t t;
 216
 217                 r = safe_atou64(value, &t);
 218                 if (r < 0)
 219                         return log_device_debug_errno(device, r, "sd-device: Failed to parse timestamp '%s': %m", value);
 220
 221                 r = device_set_usec_initialized(device, t);
 222                 if (r < 0)
 223                         return log_device_debug_errno(device, r, "sd-device: Failed to set usec-initialized to '%s': %m", value);
 224         } else if (streq(key, "DRIVER")) {
 225                 r = device_set_driver(device, value);
 226                 if (r < 0)
 227                         return log_device_debug_errno(device, r, "sd-device: Failed to set driver to '%s': %m", value);
 228         } else if (streq(key, "IFINDEX")) {
 229                 r = device_set_ifindex(device, value);
 230                 if (r < 0)
 231                         return log_device_debug_errno(device, r, "sd-device: Failed to set ifindex to '%s': %m", value);
 232         } else if (streq(key, "DEVMODE")) {
 233                 r = device_set_devmode(device, value);
 234                 if (r < 0)
 235                         return log_device_debug_errno(device, r, "sd-device: Failed to set devmode to '%s': %m", value);
 236         } else if (streq(key, "DEVUID")) {
 237                 r = device_set_devuid(device, value);
 238                 if (r < 0)
 239                         return log_device_debug_errno(device, r, "sd-device: Failed to set devuid to '%s': %m", value);
 240         } else if (streq(key, "DEVGID")) {
 241                 r = device_set_devgid(device, value);
 242                 if (r < 0)
 243                         return log_device_debug_errno(device, r, "sd-device: Failed to set devgid to '%s': %m", value);
 244         } else if (streq(key, "DEVLINKS")) {
 245                 const char *word, *state;
 246                 size_t l;
 247
 248                 FOREACH_WORD(word, l, value, state) {
 249                         char devlink[l + 1];
 250
 251                         strncpy(devlink, word, l);
 252                         devlink[l] = '\0';
 253
 254                         r = device_add_devlink(device, devlink);
 255                         if (r < 0)
 256                                 return log_device_debug_errno(device, r, "sd-device: Failed to add devlink '%s': %m", devlink);
 257                 }
 258         } else if (streq(key, "TAGS")) {
 259                 const char *word, *state;
 260                 size_t l;
 261
 262                 FOREACH_WORD_SEPARATOR(word, l, value, ":", state) {
 263                         char tag[l + 1];
 264
 265                         (void) strncpy(tag, word, l);
 266                         tag[l] = '\0';
 267
 268                         r = device_add_tag(device, tag);
 269                         if (r < 0)
 270                                 return log_device_debug_errno(device, r, "sd-device: Failed to add tag '%s': %m", tag);
 271                 }
 272         } else {
 273                 r = device_add_property_internal(device, key, value);
 274                 if (r < 0)
 275                         return log_device_debug_errno(device, r, "sd-device: Failed to add property '%s=%s': %m", key, value);
 276         }
 277
 278         return 0;
 279 }
 280
 281 static const char* const device_action_table[_DEVICE_ACTION_MAX] = {
 282         [DEVICE_ACTION_ADD] = "add",
 283         [DEVICE_ACTION_REMOVE] = "remove",
 284         [DEVICE_ACTION_CHANGE] = "change",
 285         [DEVICE_ACTION_MOVE] = "move",
 286         [DEVICE_ACTION_ONLINE] = "online",
 287         [DEVICE_ACTION_OFFLINE] = "offline",
 288         [DEVICE_ACTION_BIND] = "bind",
 289         [DEVICE_ACTION_UNBIND] = "unbind",
 290 };
 291
 292 DEFINE_STRING_TABLE_LOOKUP(device_action, DeviceAction);
 293
 294 static int device_append(sd_device *device, char *key, const char **_major, const char **_minor, uint64_t *_seqnum,
 295                          DeviceAction *_action) {
 296         DeviceAction action = _DEVICE_ACTION_INVALID;
 297         uint64_t seqnum = 0;
 298         const char *major = NULL, *minor = NULL;
 299         char *value;
 300         int r;
 301
 302         assert(device);
 303         assert(key);
 304         assert(_major);
 305         assert(_minor);
 306         assert(_seqnum);
 307         assert(_action);
 308
 309         value = strchr(key, '=');
 310         if (!value) {
 311                 log_device_debug(device, "sd-device: Not a key-value pair: '%s'", key);
 312                 return -EINVAL;
 313         }
 314
 315         *value = '\0';
 316
 317         value++;
 318
 319         if (streq(key, "MAJOR"))
 320                 major = value;
 321         else if (streq(key, "MINOR"))
 322                 minor = value;
 323         else {
 324                 if (streq(key, "ACTION")) {
 325                         action = device_action_from_string(value);
 326                         if (action == _DEVICE_ACTION_INVALID)
 327                                 return -EINVAL;
 328                 } else if (streq(key, "SEQNUM")) {
 329                         r = safe_atou64(value, &seqnum);
 330                         if (r < 0)
 331                                 return r;
 332                         else if (seqnum == 0)
 333                                  /* kernel only sends seqnum > 0 */
 334                                 return -EINVAL;
 335                 }
 336
 337                 r = device_amend(device, key, value);
 338                 if (r < 0)
 339                         return r;
 340         }
 341
 342         if (major != 0)
 343                 *_major = major;
 344
 345         if (minor != 0)
 346                 *_minor = minor;
 347
 348         if (action != _DEVICE_ACTION_INVALID)
 349                 *_action = action;
 350
 351         if (seqnum > 0)
 352                 *_seqnum = seqnum;
 353
 354         return 0;
 355 }
 356
 357 void device_seal(sd_device *device) {
 358         assert(device);
 359
 360         device->sealed = true;
 361 }
 362
 363 static int device_verify(sd_device *device, DeviceAction action, uint64_t seqnum) {
 364         assert(device);
 365
 366         if (!device->devpath || !device->subsystem || action == _DEVICE_ACTION_INVALID || seqnum == 0) {
 367                 log_device_debug(device, "sd-device: Device created from strv or nulstr lacks devpath, subsystem, action or seqnum.");
 368                 return -EINVAL;
 369         }
 370
 371         device->sealed = true;
 372
 373         return 0;
 374 }
 375
 376 int device_new_from_strv(sd_device **ret, char **strv) {
 377         _cleanup_(sd_device_unrefp) sd_device *device = NULL;
 378         char **key;
 379         const char *major = NULL, *minor = NULL;
 380         DeviceAction action = _DEVICE_ACTION_INVALID;
 381         uint64_t seqnum = 0;
 382         int r;
 383
 384         assert(ret);
 385         assert(strv);
 386
 387         r = device_new_aux(&device);
 388         if (r < 0)
 389                 return r;
 390
 391         STRV_FOREACH(key, strv) {
 392                 r = device_append(device, *key, &major, &minor, &seqnum, &action);
 393                 if (r < 0)
 394                         return r;
 395         }
 396
 397         if (major) {
 398                 r = device_set_devnum(device, major, minor);
 399                 if (r < 0)
 400                         return log_device_debug_errno(device, r, "sd-device: Failed to set devnum %s:%s: %m", major, minor);
 401         }
 402
 403         r = device_verify(device, action, seqnum);
 404         if (r < 0)
 405                 return r;
 406
 407         *ret = TAKE_PTR(device);
 408
 409         return 0;
 410 }
 411
 412 int device_new_from_nulstr(sd_device **ret, uint8_t *nulstr, size_t len) {
 413         _cleanup_(sd_device_unrefp) sd_device *device = NULL;
 414         const char *major = NULL, *minor = NULL;
 415         DeviceAction action = _DEVICE_ACTION_INVALID;
 416         uint64_t seqnum = 0;
 417         unsigned i = 0;
 418         int r;
 419
 420         assert(ret);
 421         assert(nulstr);
 422         assert(len);
 423
 424         r = device_new_aux(&device);
 425         if (r < 0)
 426                 return r;
 427
 428         while (i < len) {
 429                 char *key;
 430                 const char *end;
 431
 432                 key = (char*)&nulstr[i];
 433                 end = memchr(key, '\0', len - i);
 434                 if (!end) {
 435                         log_device_debug(device, "sd-device: Failed to parse nulstr");
 436                         return -EINVAL;
 437                 }
 438                 i += end - key + 1;
 439
 440                 r = device_append(device, key, &major, &minor, &seqnum, &action);
 441                 if (r < 0)
 442                         return r;
 443         }
 444
 445         if (major) {
 446                 r = device_set_devnum(device, major, minor);
 447                 if (r < 0)
 448                         return log_device_debug_errno(device, r, "sd-device: Failed to set devnum %s:%s: %m", major, minor);
 449         }
 450
 451         r = device_verify(device, action, seqnum);
 452         if (r < 0)
 453                 return r;
 454
 455         *ret = TAKE_PTR(device);
 456
 457         return 0;
 458 }
 459
 460 static int device_update_properties_bufs(sd_device *device) {
 461         const char *val, *prop;
 462         _cleanup_free_ char **buf_strv = NULL;
 463         _cleanup_free_ uint8_t *buf_nulstr = NULL;
 464         size_t allocated_nulstr = 0;
 465         size_t nulstr_len = 0, num = 0, i = 0;
 466
 467         assert(device);
 468
 469         if (!device->properties_buf_outdated)
 470                 return 0;
 471
 472         FOREACH_DEVICE_PROPERTY(device, prop, val) {
 473                 size_t len = 0;
 474
 475                 len = strlen(prop) + 1 + strlen(val);
 476
 477                 buf_nulstr = GREEDY_REALLOC0(buf_nulstr, allocated_nulstr, nulstr_len + len + 2);
 478                 if (!buf_nulstr)
 479                         return -ENOMEM;
 480
 481                 strscpyl((char *)buf_nulstr + nulstr_len, len + 1, prop, "=", val, NULL);
 482                 nulstr_len += len + 1;
 483                 ++num;
 484         }
 485
 486         /* build buf_strv from buf_nulstr */
 487         buf_strv = new0(char *, num + 1);
 488         if (!buf_strv)
 489                 return -ENOMEM;
 490
 491         NULSTR_FOREACH(val, (char*) buf_nulstr) {
 492                 buf_strv[i] = (char *) val;
 493                 assert(i < num);
 494                 i++;
 495         }
 496
 497         free_and_replace(device->properties_nulstr, buf_nulstr);
 498         device->properties_nulstr_len = nulstr_len;
 499         free_and_replace(device->properties_strv, buf_strv);
 500
 501         device->properties_buf_outdated = false;
 502
 503         return 0;
 504 }
 505
 506 int device_get_properties_nulstr(sd_device *device, const uint8_t **nulstr, size_t *len) {
 507         int r;
 508
 509         assert(device);
 510         assert(nulstr);
 511         assert(len);
 512
 513         r = device_update_properties_bufs(device);
 514         if (r < 0)
 515                 return r;
 516
 517         *nulstr = device->properties_nulstr;
 518         *len = device->properties_nulstr_len;
 519
 520         return 0;
 521 }
 522
 523 int device_get_properties_strv(sd_device *device, char ***strv) {
 524         int r;
 525
 526         assert(device);
 527         assert(strv);
 528
 529         r = device_update_properties_bufs(device);
 530         if (r < 0)
 531                 return r;
 532
 533         *strv = device->properties_strv;
 534
 535         return 0;
 536 }
 537
 538 int device_get_devlink_priority(sd_device *device, int *priority) {
 539         int r;
 540
 541         assert(device);
 542         assert(priority);
 543
 544         r = device_read_db(device);
 545         if (r < 0)
 546                 return r;
 547
 548         *priority = device->devlink_priority;
 549
 550         return 0;
 551 }
 552
 553 int device_get_watch_handle(sd_device *device, int *handle) {
 554         int r;
 555
 556         assert(device);
 557
 558         r = device_read_db(device);
 559         if (r < 0)
 560                 return r;
 561
 562         if (device->watch_handle < 0)
 563                 return -ENOENT;
 564
 565         if (handle)
 566                 *handle = device->watch_handle;
 567
 568         return 0;
 569 }
 570
 571 void device_set_watch_handle(sd_device *device, int handle) {
 572         assert(device);
 573
 574         device->watch_handle = handle;
 575 }
 576
 577 int device_rename(sd_device *device, const char *name) {
 578         _cleanup_free_ char *dirname = NULL;
 579         char *new_syspath;
 580         const char *interface;
 581         int r;
 582
 583         assert(device);
 584         assert(name);
 585
 586         dirname = dirname_malloc(device->syspath);
 587         if (!dirname)
 588                 return -ENOMEM;
 589
 590         new_syspath = strjoina(dirname, "/", name);
 591
 592         /* the user must trust that the new name is correct */
 593         r = device_set_syspath(device, new_syspath, false);
 594         if (r < 0)
 595                 return r;
 596
 597         r = sd_device_get_property_value(device, "INTERFACE", &interface);
 598         if (r >= 0) {
 599                 /* like DEVPATH_OLD, INTERFACE_OLD is not saved to the db, but only stays around for the current event */
 600                 r = device_add_property_internal(device, "INTERFACE_OLD", interface);
 601                 if (r < 0)
 602                         return r;
 603
 604                 r = device_add_property_internal(device, "INTERFACE", name);
 605                 if (r < 0)
 606                         return r;
 607         } else if (r != -ENOENT)
 608                 return r;
 609
 610         return 0;
 611 }
 612
 613 int device_shallow_clone(sd_device *old_device, sd_device **new_device) {
 614         _cleanup_(sd_device_unrefp) sd_device *ret = NULL;
 615         int r;
 616
 617         assert(old_device);
 618         assert(new_device);
 619
 620         r = device_new_aux(&ret);
 621         if (r < 0)
 622                 return r;
 623
 624         r = device_set_syspath(ret, old_device->syspath, false);
 625         if (r < 0)
 626                 return r;
 627
 628         r = device_set_subsystem(ret, old_device->subsystem);
 629         if (r < 0)
 630                 return r;
 631
 632         ret->devnum = old_device->devnum;
 633
 634         *new_device = TAKE_PTR(ret);
 635
 636         return 0;
 637 }
 638
 639 int device_clone_with_db(sd_device *old_device, sd_device **new_device) {
 640         _cleanup_(sd_device_unrefp) sd_device *ret = NULL;
 641         int r;
 642
 643         assert(old_device);
 644         assert(new_device);
 645
 646         r = device_shallow_clone(old_device, &ret);
 647         if (r < 0)
 648                 return r;
 649
 650         r = device_read_db(ret);
 651         if (r < 0)
 652                 return r;
 653
 654         ret->sealed = true;
 655
 656         *new_device = TAKE_PTR(ret);
 657
 658         return 0;
 659 }
 660
 661 int device_new_from_synthetic_event(sd_device **new_device, const char *syspath, const char *action) {
 662         _cleanup_(sd_device_unrefp) sd_device *ret = NULL;
 663         int r;
 664
 665         assert(new_device);
 666         assert(syspath);
 667         assert(action);
 668
 669         r = sd_device_new_from_syspath(&ret, syspath);
 670         if (r < 0)
 671                 return r;
 672
 673         r = device_read_uevent_file(ret);
 674         if (r < 0)
 675                 return r;
 676
 677         r = device_add_property_internal(ret, "ACTION", action);
 678         if (r < 0)
 679                 return r;
 680
 681         *new_device = TAKE_PTR(ret);
 682
 683         return 0;
 684 }
 685
 686 int device_new_from_stat_rdev(sd_device **ret, const struct stat *st) {
 687         char type;
 688
 689         assert(ret);
 690         assert(st);
 691
 692         if (S_ISBLK(st->st_mode))
 693                 type = 'b';
 694         else if (S_ISCHR(st->st_mode))
 695                 type = 'c';
 696         else
 697                 return -ENOTTY;
 698
 699         return sd_device_new_from_devnum(ret, type, st->st_rdev);
 700 }
 701
 702 int device_copy_properties(sd_device *device_dst, sd_device *device_src) {
 703         const char *property, *value;
 704         Iterator i;
 705         int r;
 706
 707         assert(device_dst);
 708         assert(device_src);
 709
 710         r = device_properties_prepare(device_src);
 711         if (r < 0)
 712                 return r;
 713
 714         ORDERED_HASHMAP_FOREACH_KEY(value, property, device_src->properties_db, i) {
 715                 r = device_add_property_aux(device_dst, property, value, true);
 716                 if (r < 0)
 717                         return r;
 718         }
 719
 720         ORDERED_HASHMAP_FOREACH_KEY(value, property, device_src->properties, i) {
 721                 r = device_add_property_aux(device_dst, property, value, false);
 722                 if (r < 0)
 723                         return r;
 724         }
 725
 726         return 0;
 727 }
 728
 729 void device_cleanup_tags(sd_device *device) {
 730         assert(device);
 731
 732         set_free_free(device->tags);
 733         device->tags = NULL;
 734         device->property_tags_outdated = true;
 735         device->tags_generation++;
 736 }
 737
 738 void device_cleanup_devlinks(sd_device *device) {
 739         assert(device);
 740
 741         set_free_free(device->devlinks);
 742         device->devlinks = NULL;
 743         device->property_devlinks_outdated = true;
 744         device->devlinks_generation++;
 745 }
 746
 747 void device_remove_tag(sd_device *device, const char *tag) {
 748         assert(device);
 749         assert(tag);
 750
 751         free(set_remove(device->tags, tag));
 752         device->property_tags_outdated = true;
 753         device->tags_generation++;
 754 }
 755
 756 static int device_tag(sd_device *device, const char *tag, bool add) {
 757         const char *id;
 758         char *path;
 759         int r;
 760
 761         assert(device);
 762         assert(tag);
 763
 764         r = device_get_id_filename(device, &id);
 765         if (r < 0)
 766                 return r;
 767
 768         path = strjoina("/run/udev/tags/", tag, "/", id);
 769
 770         if (add) {
 771                 r = touch_file(path, true, USEC_INFINITY, UID_INVALID, GID_INVALID, 0444);
 772                 if (r < 0)
 773                         return r;
 774         } else {
 775                 r = unlink(path);
 776                 if (r < 0 && errno != ENOENT)
 777                         return -errno;
 778         }
 779
 780         return 0;
 781 }
 782
 783 int device_tag_index(sd_device *device, sd_device *device_old, bool add) {
 784         const char *tag;
 785         int r = 0, k;
 786
 787         if (add && device_old) {
 788                 /* delete possible left-over tags */
 789                 FOREACH_DEVICE_TAG(device_old, tag) {
 790                         if (!sd_device_has_tag(device, tag)) {
 791                                 k = device_tag(device_old, tag, false);
 792                                 if (r >= 0 && k < 0)
 793                                         r = k;
 794                         }
 795                 }
 796         }
 797
 798         FOREACH_DEVICE_TAG(device, tag) {
 799                 k = device_tag(device, tag, add);
 800                 if (r >= 0 && k < 0)
 801                         r = k;
 802         }
 803
 804         return r;
 805 }
 806
 807 static bool device_has_info(sd_device *device) {
 808         assert(device);
 809
 810         if (!set_isempty(device->devlinks))
 811                 return true;
 812
 813         if (device->devlink_priority != 0)
 814                 return true;
 815
 816         if (!ordered_hashmap_isempty(device->properties_db))
 817                 return true;
 818
 819         if (!set_isempty(device->tags))
 820                 return true;
 821
 822         if (device->watch_handle >= 0)
 823                 return true;
 824
 825         return false;
 826 }
 827
 828 void device_set_db_persist(sd_device *device) {
 829         assert(device);
 830
 831         device->db_persist = true;
 832 }
 833
 834 int device_update_db(sd_device *device) {
 835         const char *id;
 836         char *path;
 837         _cleanup_fclose_ FILE *f = NULL;
 838         _cleanup_free_ char *path_tmp = NULL;
 839         bool has_info;
 840         int r;
 841
 842         assert(device);
 843
 844         has_info = device_has_info(device);
 845
 846         r = device_get_id_filename(device, &id);
 847         if (r < 0)
 848                 return r;
 849
 850         path = strjoina("/run/udev/data/", id);
 851
 852         /* do not store anything for otherwise empty devices */
 853         if (!has_info && major(device->devnum) == 0 && device->ifindex == 0) {
 854                 r = unlink(path);
 855                 if (r < 0 && errno != ENOENT)
 856                         return -errno;
 857
 858                 return 0;
 859         }
 860
 861         /* write a database file */
 862         r = mkdir_parents(path, 0755);
 863         if (r < 0)
 864                 return r;
 865
 866         r = fopen_temporary(path, &f, &path_tmp);
 867         if (r < 0)
 868                 return r;
 869
 870         /*
 871          * set 'sticky' bit to indicate that we should not clean the
 872          * database when we transition from initramfs to the real root
 873          */
 874         if (device->db_persist) {
 875                 r = fchmod(fileno(f), 01644);
 876                 if (r < 0) {
 877                         r = -errno;
 878                         goto fail;
 879                 }
 880         } else {
 881                 r = fchmod(fileno(f), 0644);
 882                 if (r < 0) {
 883                         r = -errno;
 884                         goto fail;
 885                 }
 886         }
 887
 888         if (has_info) {
 889                 const char *property, *value, *tag;
 890                 Iterator i;
 891
 892                 if (major(device->devnum) > 0) {
 893                         const char *devlink;
 894
 895                         FOREACH_DEVICE_DEVLINK(device, devlink)
 896                                 fprintf(f, "S:%s\n", devlink + STRLEN("/dev/"));
 897
 898                         if (device->devlink_priority != 0)
 899                                 fprintf(f, "L:%i\n", device->devlink_priority);
 900
 901                         if (device->watch_handle >= 0)
 902                                 fprintf(f, "W:%i\n", device->watch_handle);
 903                 }
 904
 905                 if (device->usec_initialized > 0)
 906                         fprintf(f, "I:"USEC_FMT"\n", device->usec_initialized);
 907
 908                 ORDERED_HASHMAP_FOREACH_KEY(value, property, device->properties_db, i)
 909                         fprintf(f, "E:%s=%s\n", property, value);
 910
 911                 FOREACH_DEVICE_TAG(device, tag)
 912                         fprintf(f, "G:%s\n", tag);
 913         }
 914
 915         r = fflush_and_check(f);
 916         if (r < 0)
 917                 goto fail;
 918
 919         r = rename(path_tmp, path);
 920         if (r < 0) {
 921                 r = -errno;
 922                 goto fail;
 923         }
 924
 925         log_device_debug(device, "sd-device: Created %s file '%s' for '%s'", has_info ? "db" : "empty",
 926                          path, device->devpath);
 927
 928         return 0;
 929
 930 fail:
 931         (void) unlink(path);
 932         (void) unlink(path_tmp);
 933
 934         return log_device_debug_errno(device, r, "sd-device: Failed to create %s file '%s' for '%s'", has_info ? "db" : "empty", path, device->devpath);
 935 }
 936
 937 int device_delete_db(sd_device *device) {
 938         const char *id;
 939         char *path;
 940         int r;
 941
 942         assert(device);
 943
 944         r = device_get_id_filename(device, &id);
 945         if (r < 0)
 946                 return r;
 947
 948         path = strjoina("/run/udev/data/", id);
 949
 950         r = unlink(path);
 951         if (r < 0 && errno != ENOENT)
 952                 return -errno;
 953
 954         return 0;
 955 }