src/libudev/libudev-device.c

   1 /*
   2  * libudev - interface to udev device information
   3  *
   4  * Copyright (C) 2008-2010 Kay Sievers <kay.sievers@vrfy.org>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <stddef.h>
  15 #include <unistd.h>
  16 #include <stdbool.h>
  17 #include <errno.h>
  18 #include <string.h>
  19 #include <dirent.h>
  20 #include <fcntl.h>
  21 #include <ctype.h>
  22 #include <net/if.h>
  23 #include <sys/stat.h>
  24 #include <sys/ioctl.h>
  25 #include <sys/socket.h>
  26 #include <linux/sockios.h>
  27
  28 #include "libudev.h"
  29 #include "libudev-private.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 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         struct udev_device *parent_device;
  49         char *syspath;
  50         const char *devpath;
  51         char *sysname;
  52         const char *sysnum;
  53         char *devnode;
  54         mode_t devnode_mode;
  55         char *subsystem;
  56         char *devtype;
  57         char *driver;
  58         char *action;
  59         char *devpath_old;
  60         char *id_filename;
  61         char **envp;
  62         char *monitor_buf;
  63         size_t monitor_buf_len;
  64         struct udev_list devlinks_list;
  65         struct udev_list properties_list;
  66         struct udev_list sysattr_value_list;
  67         struct udev_list sysattr_list;
  68         struct udev_list tags_list;
  69         unsigned long long int seqnum;
  70         unsigned long long int usec_initialized;
  71         int devlink_priority;
  72         int refcount;
  73         dev_t devnum;
  74         int ifindex;
  75         int watch_handle;
  76         int maj, min;
  77         bool parent_set;
  78         bool subsystem_set;
  79         bool devtype_set;
  80         bool devlinks_uptodate;
  81         bool envp_uptodate;
  82         bool tags_uptodate;
  83         bool driver_set;
  84         bool info_loaded;
  85         bool db_loaded;
  86         bool uevent_loaded;
  87         bool is_initialized;
  88         bool sysattr_list_read;
  89         bool db_persist;
  90 };
  91
  92 /**
  93  * udev_device_get_seqnum:
  94  * @udev_device: udev device
  95  *
  96  * This is only valid if the device was received through a monitor. Devices read from
  97  * sys do not have a sequence number.
  98  *
  99  * Returns: the kernel event sequence number, or 0 if there is no sequence number available.
 100  **/
 101 _public_ unsigned long long int udev_device_get_seqnum(struct udev_device *udev_device)
 102 {
 103         if (udev_device == NULL)
 104                 return 0;
 105         return udev_device->seqnum;
 106 }
 107
 108 static int udev_device_set_seqnum(struct udev_device *udev_device, unsigned long long int seqnum)
 109 {
 110         char num[32];
 111
 112         udev_device->seqnum = seqnum;
 113         snprintf(num, sizeof(num), "%llu", seqnum);
 114         udev_device_add_property(udev_device, "SEQNUM", num);
 115         return 0;
 116 }
 117
 118 int udev_device_get_ifindex(struct udev_device *udev_device)
 119 {
 120         if (!udev_device->info_loaded)
 121                 udev_device_read_uevent_file(udev_device);
 122         return udev_device->ifindex;
 123 }
 124
 125 static int udev_device_set_ifindex(struct udev_device *udev_device, int ifindex)
 126 {
 127         char num[32];
 128
 129         udev_device->ifindex = ifindex;
 130         snprintf(num, sizeof(num), "%u", ifindex);
 131         udev_device_add_property(udev_device, "IFINDEX", num);
 132         return 0;
 133 }
 134
 135 /**
 136  * udev_device_get_devnum:
 137  * @udev_device: udev device
 138  *
 139  * Get the device major/minor number.
 140  *
 141  * Returns: the dev_t number.
 142  **/
 143 _public_ dev_t udev_device_get_devnum(struct udev_device *udev_device)
 144 {
 145         if (udev_device == NULL)
 146                 return makedev(0, 0);
 147         if (!udev_device->info_loaded)
 148                 udev_device_read_uevent_file(udev_device);
 149         return udev_device->devnum;
 150 }
 151
 152 static int udev_device_set_devnum(struct udev_device *udev_device, dev_t devnum)
 153 {
 154         char num[32];
 155
 156         udev_device->devnum = devnum;
 157
 158         snprintf(num, sizeof(num), "%u", major(devnum));
 159         udev_device_add_property(udev_device, "MAJOR", num);
 160         snprintf(num, sizeof(num), "%u", minor(devnum));
 161         udev_device_add_property(udev_device, "MINOR", num);
 162         return 0;
 163 }
 164
 165 const char *udev_device_get_devpath_old(struct udev_device *udev_device)
 166 {
 167         return udev_device->devpath_old;
 168 }
 169
 170 static int udev_device_set_devpath_old(struct udev_device *udev_device, const char *devpath_old)
 171 {
 172         const char *pos;
 173
 174         free(udev_device->devpath_old);
 175         udev_device->devpath_old = strdup(devpath_old);
 176         if (udev_device->devpath_old == NULL)
 177                 return -ENOMEM;
 178         udev_device_add_property(udev_device, "DEVPATH_OLD", udev_device->devpath_old);
 179
 180         pos = strrchr(udev_device->devpath_old, '/');
 181         if (pos == NULL)
 182                 return -EINVAL;
 183         return 0;
 184 }
 185
 186 /**
 187  * udev_device_get_driver:
 188  * @udev_device: udev device
 189  *
 190  * Get the kernel driver name.
 191  *
 192  * Returns: the driver name string, or #NULL if there is no driver attached.
 193  **/
 194 _public_ const char *udev_device_get_driver(struct udev_device *udev_device)
 195 {
 196         char driver[UTIL_NAME_SIZE];
 197
 198         if (udev_device == NULL)
 199                 return NULL;
 200         if (!udev_device->driver_set) {
 201                 udev_device->driver_set = true;
 202                 if (util_get_sys_core_link_value(udev_device->udev, "driver", udev_device->syspath, driver, sizeof(driver)) > 0)
 203                         udev_device->driver = strdup(driver);
 204         }
 205         return udev_device->driver;
 206 }
 207
 208 static int udev_device_set_driver(struct udev_device *udev_device, const char *driver)
 209 {
 210         free(udev_device->driver);
 211         udev_device->driver = strdup(driver);
 212         if (udev_device->driver == NULL)
 213                 return -ENOMEM;
 214         udev_device->driver_set = true;
 215         udev_device_add_property(udev_device, "DRIVER", udev_device->driver);
 216         return 0;
 217 }
 218
 219 /**
 220  * udev_device_get_devtype:
 221  * @udev_device: udev device
 222  *
 223  * Retrieve the devtype string of the udev device.
 224  *
 225  * Returns: the devtype name of the udev device, or #NULL if it can not be determined
 226  **/
 227 _public_ const char *udev_device_get_devtype(struct udev_device *udev_device)
 228 {
 229         if (udev_device == NULL)
 230                 return NULL;
 231         if (!udev_device->devtype_set) {
 232                 udev_device->devtype_set = true;
 233                 udev_device_read_uevent_file(udev_device);
 234         }
 235         return udev_device->devtype;
 236 }
 237
 238 static int udev_device_set_devtype(struct udev_device *udev_device, const char *devtype)
 239 {
 240         free(udev_device->devtype);
 241         udev_device->devtype = strdup(devtype);
 242         if (udev_device->devtype == NULL)
 243                 return -ENOMEM;
 244         udev_device->devtype_set = true;
 245         udev_device_add_property(udev_device, "DEVTYPE", udev_device->devtype);
 246         return 0;
 247 }
 248
 249 static int udev_device_set_subsystem(struct udev_device *udev_device, const char *subsystem)
 250 {
 251         free(udev_device->subsystem);
 252         udev_device->subsystem = strdup(subsystem);
 253         if (udev_device->subsystem == NULL)
 254                 return -ENOMEM;
 255         udev_device->subsystem_set = true;
 256         udev_device_add_property(udev_device, "SUBSYSTEM", udev_device->subsystem);
 257         return 0;
 258 }
 259
 260 /**
 261  * udev_device_get_subsystem:
 262  * @udev_device: udev device
 263  *
 264  * Retrieve the subsystem string of the udev device. The string does not
 265  * contain any "/".
 266  *
 267  * Returns: the subsystem name of the udev device, or #NULL if it can not be determined
 268  **/
 269 _public_ const char *udev_device_get_subsystem(struct udev_device *udev_device)
 270 {
 271         char subsystem[UTIL_NAME_SIZE];
 272
 273         if (udev_device == NULL)
 274                 return NULL;
 275         if (!udev_device->subsystem_set) {
 276                 udev_device->subsystem_set = true;
 277                 /* read "subsystem" link */
 278                 if (util_get_sys_core_link_value(udev_device->udev, "subsystem", udev_device->syspath, subsystem, sizeof(subsystem)) > 0) {
 279                         udev_device_set_subsystem(udev_device, subsystem);
 280                         return udev_device->subsystem;
 281                 }
 282                 /* implicit names */
 283                 if (startswith(udev_device->devpath, "/module/")) {
 284                         udev_device_set_subsystem(udev_device, "module");
 285                         return udev_device->subsystem;
 286                 }
 287                 if (strstr(udev_device->devpath, "/drivers/") != NULL) {
 288                         udev_device_set_subsystem(udev_device, "drivers");
 289                         return udev_device->subsystem;
 290                 }
 291                 if (startswith(udev_device->devpath, "/subsystem/") ||
 292                     startswith(udev_device->devpath, "/class/") ||
 293                     startswith(udev_device->devpath, "/bus/")) {
 294                         udev_device_set_subsystem(udev_device, "subsystem");
 295                         return udev_device->subsystem;
 296                 }
 297         }
 298         return udev_device->subsystem;
 299 }
 300
 301 mode_t udev_device_get_devnode_mode(struct udev_device *udev_device)
 302 {
 303         if (!udev_device->info_loaded)
 304                 udev_device_read_uevent_file(udev_device);
 305         return udev_device->devnode_mode;
 306 }
 307
 308 static int udev_device_set_devnode_mode(struct udev_device *udev_device, mode_t mode)
 309 {
 310         char num[32];
 311
 312         udev_device->devnode_mode = mode;
 313         snprintf(num, sizeof(num), "%#o", mode);
 314         udev_device_add_property(udev_device, "DEVMODE", num);
 315         return 0;
 316 }
 317
 318 struct udev_list_entry *udev_device_add_property(struct udev_device *udev_device, const char *key, const char *value)
 319 {
 320         udev_device->envp_uptodate = false;
 321         if (value == NULL) {
 322                 struct udev_list_entry *list_entry;
 323
 324                 list_entry = udev_device_get_properties_list_entry(udev_device);
 325                 list_entry = udev_list_entry_get_by_name(list_entry, key);
 326                 if (list_entry != NULL)
 327                         udev_list_entry_delete(list_entry);
 328                 return NULL;
 329         }
 330         return udev_list_entry_add(&udev_device->properties_list, key, value);
 331 }
 332
 333 static struct udev_list_entry *udev_device_add_property_from_string(struct udev_device *udev_device, const char *property)
 334 {
 335         char name[UTIL_LINE_SIZE];
 336         char *val;
 337
 338         util_strscpy(name, sizeof(name), property);
 339         val = strchr(name, '=');
 340         if (val == NULL)
 341                 return NULL;
 342         val[0] = '\0';
 343         val = &val[1];
 344         if (val[0] == '\0')
 345                 val = NULL;
 346         return udev_device_add_property(udev_device, name, val);
 347 }
 348
 349 /*
 350  * parse property string, and if needed, update internal values accordingly
 351  *
 352  * udev_device_add_property_from_string_parse_finish() needs to be
 353  * called after adding properties, and its return value checked
 354  *
 355  * udev_device_set_info_loaded() needs to be set, to avoid trying
 356  * to use a device without a DEVPATH set
 357  */
 358 void udev_device_add_property_from_string_parse(struct udev_device *udev_device, const char *property)
 359 {
 360         if (startswith(property, "DEVPATH=")) {
 361                 char path[UTIL_PATH_SIZE];
 362
 363                 util_strscpyl(path, sizeof(path), TEST_PREFIX "/sys", &property[8], NULL);
 364                 udev_device_set_syspath(udev_device, path);
 365         } else if (startswith(property, "SUBSYSTEM=")) {
 366                 udev_device_set_subsystem(udev_device, &property[10]);
 367         } else if (startswith(property, "DEVTYPE=")) {
 368                 udev_device_set_devtype(udev_device, &property[8]);
 369         } else if (startswith(property, "DEVNAME=")) {
 370                 udev_device_set_devnode(udev_device, &property[8]);
 371         } else if (startswith(property, "DEVLINKS=")) {
 372                 char devlinks[UTIL_PATH_SIZE];
 373                 char *slink;
 374                 char *next;
 375
 376                 util_strscpy(devlinks, sizeof(devlinks), &property[9]);
 377                 slink = devlinks;
 378                 next = strchr(slink, ' ');
 379                 while (next != NULL) {
 380                         next[0] = '\0';
 381                         udev_device_add_devlink(udev_device, slink, 0);
 382                         slink = &next[1];
 383                         next = strchr(slink, ' ');
 384                 }
 385                 if (slink[0] != '\0')
 386                         udev_device_add_devlink(udev_device, slink, 0);
 387         } else if (startswith(property, "TAGS=")) {
 388                 char tags[UTIL_PATH_SIZE];
 389                 char *next;
 390
 391                 util_strscpy(tags, sizeof(tags), &property[5]);
 392                 next = strchr(tags, ':');
 393                 if (next != NULL) {
 394                         next++;
 395                         while (next[0] != '\0') {
 396                                 char *tag;
 397
 398                                 tag = next;
 399                                 next = strchr(tag, ':');
 400                                 if (next == NULL)
 401                                         break;
 402                                 next[0] = '\0';
 403                                 next++;
 404                                 udev_device_add_tag(udev_device, tag);
 405                         }
 406                 }
 407         } else if (startswith(property, "USEC_INITIALIZED=")) {
 408                 udev_device_set_usec_initialized(udev_device, strtoull(&property[19], NULL, 10));
 409         } else if (startswith(property, "DRIVER=")) {
 410                 udev_device_set_driver(udev_device, &property[7]);
 411         } else if (startswith(property, "ACTION=")) {
 412                 udev_device_set_action(udev_device, &property[7]);
 413         } else if (startswith(property, "MAJOR=")) {
 414                 udev_device->maj = strtoull(&property[6], NULL, 10);
 415         } else if (startswith(property, "MINOR=")) {
 416                 udev_device->min = strtoull(&property[6], NULL, 10);
 417         } else if (startswith(property, "DEVPATH_OLD=")) {
 418                 udev_device_set_devpath_old(udev_device, &property[12]);
 419         } else if (startswith(property, "SEQNUM=")) {
 420                 udev_device_set_seqnum(udev_device, strtoull(&property[7], NULL, 10));
 421         } else if (startswith(property, "IFINDEX=")) {
 422                 udev_device_set_ifindex(udev_device, strtoull(&property[8], NULL, 10));
 423         } else if (startswith(property, "DEVMODE=")) {
 424                 udev_device_set_devnode_mode(udev_device, strtoul(&property[8], NULL, 8));
 425         } else {
 426                 udev_device_add_property_from_string(udev_device, property);
 427         }
 428 }
 429
 430 int udev_device_add_property_from_string_parse_finish(struct udev_device *udev_device)
 431 {
 432         if (udev_device->maj > 0)
 433                 udev_device_set_devnum(udev_device, makedev(udev_device->maj, udev_device->min));
 434         udev_device->maj = 0;
 435         udev_device->min = 0;
 436
 437         if (udev_device->devpath == NULL || udev_device->subsystem == NULL)
 438                 return -EINVAL;
 439         return 0;
 440 }
 441
 442 /**
 443  * udev_device_get_property_value:
 444  * @udev_device: udev device
 445  * @key: property name
 446  *
 447  * Get the value of a given property.
 448  *
 449  * Returns: the property string, or #NULL if there is no such property.
 450  **/
 451 _public_ const char *udev_device_get_property_value(struct udev_device *udev_device, const char *key)
 452 {
 453         struct udev_list_entry *list_entry;
 454
 455         if (udev_device == NULL)
 456                 return NULL;
 457         if (key == NULL)
 458                 return NULL;
 459
 460         list_entry = udev_device_get_properties_list_entry(udev_device);
 461         list_entry = udev_list_entry_get_by_name(list_entry, key);
 462         return udev_list_entry_get_value(list_entry);
 463 }
 464
 465 int udev_device_read_db(struct udev_device *udev_device, const char *dbfile)
 466 {
 467         char filename[UTIL_PATH_SIZE];
 468         char line[UTIL_LINE_SIZE];
 469         FILE *f;
 470
 471         /* providing a database file will always force-load it */
 472         if (dbfile == NULL) {
 473                 const char *id;
 474
 475                 if (udev_device->db_loaded)
 476                         return 0;
 477                 udev_device->db_loaded = true;
 478
 479                 id = udev_device_get_id_filename(udev_device);
 480                 if (id == NULL)
 481                         return -1;
 482                 util_strscpyl(filename, sizeof(filename), TEST_PREFIX "/run/udev/data/", id, NULL);
 483                 dbfile = filename;
 484         }
 485
 486         f = fopen(dbfile, "re");
 487         if (f == NULL) {
 488                 udev_dbg(udev_device->udev, "no db file to read %s: %m\n", dbfile);
 489                 return -1;
 490         }
 491         udev_device->is_initialized = true;
 492
 493         while (fgets(line, sizeof(line), f)) {
 494                 ssize_t len;
 495                 const char *val;
 496                 struct udev_list_entry *entry;
 497
 498                 len = strlen(line);
 499                 if (len < 4)
 500                         break;
 501                 line[len-1] = '\0';
 502                 val = &line[2];
 503                 switch(line[0]) {
 504                 case 'S':
 505                         util_strscpyl(filename, sizeof(filename), TEST_PREFIX "/dev/", val, NULL);
 506                         udev_device_add_devlink(udev_device, filename, 0);
 507                         break;
 508                 case 'L':
 509                         udev_device_set_devlink_priority(udev_device, atoi(val));
 510                         break;
 511                 case 'E':
 512                         entry = udev_device_add_property_from_string(udev_device, val);
 513                         udev_list_entry_set_num(entry, true);
 514                         break;
 515                 case 'G':
 516                         udev_device_add_tag(udev_device, val);
 517                         break;
 518                 case 'W':
 519                         udev_device_set_watch_handle(udev_device, atoi(val));
 520                         break;
 521                 case 'I':
 522                         udev_device_set_usec_initialized(udev_device, strtoull(val, NULL, 10));
 523                         break;
 524                 }
 525         }
 526         fclose(f);
 527
 528         udev_dbg(udev_device->udev, "device %p filled with db file data\n", udev_device);
 529         return 0;
 530 }
 531
 532 int udev_device_read_uevent_file(struct udev_device *udev_device)
 533 {
 534         char filename[UTIL_PATH_SIZE];
 535         FILE *f;
 536         char line[UTIL_LINE_SIZE];
 537         int maj = 0;
 538         int min = 0;
 539
 540         if (udev_device->uevent_loaded)
 541                 return 0;
 542
 543         util_strscpyl(filename, sizeof(filename), udev_device->syspath, "/uevent", NULL);
 544         f = fopen(filename, "re");
 545         if (f == NULL)
 546                 return -1;
 547         udev_device->uevent_loaded = true;
 548
 549         while (fgets(line, sizeof(line), f)) {
 550                 char *pos;
 551
 552                 pos = strchr(line, '\n');
 553                 if (pos == NULL)
 554                         continue;
 555                 pos[0] = '\0';
 556
 557                 if (startswith(line, "DEVTYPE=")) {
 558                         udev_device_set_devtype(udev_device, &line[8]);
 559                         continue;
 560                 }
 561                 if (startswith(line, "IFINDEX=")) {
 562                         udev_device_set_ifindex(udev_device, strtoull(&line[8], NULL, 10));
 563                         continue;
 564                 }
 565                 if (startswith(line, "DEVNAME=")) {
 566                         udev_device_set_devnode(udev_device, &line[8]);
 567                         continue;
 568                 }
 569
 570                 if (startswith(line, "MAJOR="))
 571                         maj = strtoull(&line[6], NULL, 10);
 572                 else if (startswith(line, "MINOR="))
 573                         min = strtoull(&line[6], NULL, 10);
 574                 else if (startswith(line, "DEVMODE="))
 575                         udev_device->devnode_mode = strtoul(&line[8], NULL, 8);
 576
 577                 udev_device_add_property_from_string(udev_device, line);
 578         }
 579
 580         udev_device->devnum = makedev(maj, min);
 581         fclose(f);
 582         return 0;
 583 }
 584
 585 void udev_device_set_info_loaded(struct udev_device *device)
 586 {
 587         device->info_loaded = true;
 588 }
 589
 590 struct udev_device *udev_device_new(struct udev *udev)
 591 {
 592         struct udev_device *udev_device;
 593         struct udev_list_entry *list_entry;
 594
 595         if (udev == NULL)
 596                 return NULL;
 597
 598         udev_device = calloc(1, sizeof(struct udev_device));
 599         if (udev_device == NULL)
 600                 return NULL;
 601         udev_device->refcount = 1;
 602         udev_device->udev = udev;
 603         udev_list_init(udev, &udev_device->devlinks_list, true);
 604         udev_list_init(udev, &udev_device->properties_list, true);
 605         udev_list_init(udev, &udev_device->sysattr_value_list, true);
 606         udev_list_init(udev, &udev_device->sysattr_list, false);
 607         udev_list_init(udev, &udev_device->tags_list, true);
 608         udev_device->watch_handle = -1;
 609         /* copy global properties */
 610         udev_list_entry_foreach(list_entry, udev_get_properties_list_entry(udev))
 611                 udev_device_add_property(udev_device,
 612                                          udev_list_entry_get_name(list_entry),
 613                                          udev_list_entry_get_value(list_entry));
 614         return udev_device;
 615 }
 616
 617 /**
 618  * udev_device_new_from_syspath:
 619  * @udev: udev library context
 620  * @syspath: sys device path including sys directory
 621  *
 622  * Create new udev device, and fill in information from the sys
 623  * device and the udev database entry. The syspath is the absolute
 624  * path to the device, including the sys mount point.
 625  *
 626  * The initial refcount is 1, and needs to be decremented to
 627  * release the resources of the udev device.
 628  *
 629  * Returns: a new udev device, or #NULL, if it does not exist
 630  **/
 631 _public_ struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *syspath)
 632 {
 633         const char *subdir;
 634         char path[UTIL_PATH_SIZE];
 635         char *pos;
 636         struct stat statbuf;
 637         struct udev_device *udev_device;
 638
 639         if (udev == NULL)
 640                 return NULL;
 641         if (syspath == NULL)
 642                 return NULL;
 643
 644         /* path starts in sys */
 645         if (!startswith(syspath, TEST_PREFIX "/sys")) {
 646                 udev_dbg(udev, "not in sys :%s\n", syspath);
 647                 return NULL;
 648         }
 649
 650         /* path is not a root directory */
 651         subdir = syspath + strlen(TEST_PREFIX "/sys");
 652         pos = strrchr(subdir, '/');
 653         if (pos == NULL || pos[1] == '\0' || pos < &subdir[2])
 654                 return NULL;
 655
 656         /* resolve possible symlink to real path */
 657         util_strscpy(path, sizeof(path), syspath);
 658         util_resolve_sys_link(udev, path, sizeof(path));
 659
 660         if (startswith(path + strlen(TEST_PREFIX "/sys"), "/devices/")) {
 661                 char file[UTIL_PATH_SIZE];
 662
 663                 /* all "devices" require a "uevent" file */
 664                 util_strscpyl(file, sizeof(file), path, "/uevent", NULL);
 665                 if (stat(file, &statbuf) != 0)
 666                         return NULL;
 667         } else {
 668                 /* everything else just needs to be a directory */
 669                 if (stat(path, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode))
 670                         return NULL;
 671         }
 672
 673         udev_device = udev_device_new(udev);
 674         if (udev_device == NULL)
 675                 return NULL;
 676
 677         udev_device_set_syspath(udev_device, path);
 678         udev_dbg(udev, "device %p has devpath '%s'\n", udev_device, udev_device_get_devpath(udev_device));
 679
 680         return udev_device;
 681 }
 682
 683 /**
 684  * udev_device_new_from_devnum:
 685  * @udev: udev library context
 686  * @type: char or block device
 687  * @devnum: device major/minor number
 688  *
 689  * Create new udev device, and fill in information from the sys
 690  * device and the udev database entry. The device is looked-up
 691  * by its major/minor number and type. Character and block device
 692  * numbers are not unique across the two types.
 693  *
 694  * The initial refcount is 1, and needs to be decremented to
 695  * release the resources of the udev device.
 696  *
 697  * Returns: a new udev device, or #NULL, if it does not exist
 698  **/
 699 _public_ struct udev_device *udev_device_new_from_devnum(struct udev *udev, char type, dev_t devnum)
 700 {
 701         char path[UTIL_PATH_SIZE];
 702         const char *type_str;
 703
 704         if (type == 'b')
 705                 type_str = "block";
 706         else if (type == 'c')
 707                 type_str = "char";
 708         else
 709                 return NULL;
 710
 711         /* use /sys/dev/{block,char}/<maj>:<min> link */
 712         snprintf(path, sizeof(path), TEST_PREFIX "/sys/dev/%s/%u:%u",
 713                  type_str, major(devnum), minor(devnum));
 714         return udev_device_new_from_syspath(udev, path);
 715 }
 716
 717 struct udev_device *udev_device_new_from_id_filename(struct udev *udev, char *id)
 718 {
 719         char type;
 720         int maj, min;
 721         char subsys[UTIL_PATH_SIZE];
 722         char *sysname;
 723
 724         switch(id[0]) {
 725         case 'b':
 726         case 'c':
 727                 if (sscanf(id, "%c%i:%i", &type, &maj, &min) != 3)
 728                         return NULL;
 729                 return udev_device_new_from_devnum(udev, type, makedev(maj, min));
 730         case 'n': {
 731                 int sk;
 732                 struct ifreq ifr;
 733                 struct udev_device *dev;
 734                 int ifindex;
 735
 736                 ifindex = strtoul(&id[1], NULL, 10);
 737                 if (ifindex <= 0)
 738                         return NULL;
 739
 740                 sk = socket(PF_INET, SOCK_DGRAM, 0);
 741                 if (sk < 0)
 742                         return NULL;
 743                 memset(&ifr, 0x00, sizeof(struct ifreq));
 744                 ifr.ifr_ifindex = ifindex;
 745                 if (ioctl(sk, SIOCGIFNAME, &ifr) != 0) {
 746                         close(sk);
 747                         return NULL;
 748                 }
 749                 close(sk);
 750
 751                 dev = udev_device_new_from_subsystem_sysname(udev, "net", ifr.ifr_name);
 752                 if (dev == NULL)
 753                         return NULL;
 754                 if (udev_device_get_ifindex(dev) == ifindex)
 755                         return dev;
 756                 udev_device_unref(dev);
 757                 return NULL;
 758         }
 759         case '+':
 760                 util_strscpy(subsys, sizeof(subsys), &id[1]);
 761                 sysname = strchr(subsys, ':');
 762                 if (sysname == NULL)
 763                         return NULL;
 764                 sysname[0] = '\0';
 765                 sysname = &sysname[1];
 766                 return udev_device_new_from_subsystem_sysname(udev, subsys, sysname);
 767         default:
 768                 return NULL;
 769         }
 770 }
 771
 772 /**
 773  * udev_device_new_from_subsystem_sysname:
 774  * @udev: udev library context
 775  * @subsystem: the subsystem of the device
 776  * @sysname: the name of the device
 777  *
 778  * Create new udev device, and fill in information from the sys device
 779  * and the udev database entry. The device is looked up by the subsystem
 780  * and name string of the device, like "mem" / "zero", or "block" / "sda".
 781  *
 782  * The initial refcount is 1, and needs to be decremented to
 783  * release the resources of the udev device.
 784  *
 785  * Returns: a new udev device, or #NULL, if it does not exist
 786  **/
 787 _public_ struct udev_device *udev_device_new_from_subsystem_sysname(struct udev *udev, const char *subsystem, const char *sysname)
 788 {
 789         char path[UTIL_PATH_SIZE];
 790         struct stat statbuf;
 791
 792         if (streq(subsystem, "subsystem")) {
 793                 util_strscpyl(path, sizeof(path), TEST_PREFIX "/sys/subsystem/", sysname, NULL);
 794                 if (stat(path, &statbuf) == 0)
 795                         goto found;
 796
 797                 util_strscpyl(path, sizeof(path), TEST_PREFIX "/sys/bus/", sysname, NULL);
 798                 if (stat(path, &statbuf) == 0)
 799                         goto found;
 800
 801                 util_strscpyl(path, sizeof(path), TEST_PREFIX "/sys/class/", sysname, NULL);
 802                 if (stat(path, &statbuf) == 0)
 803                         goto found;
 804                 goto out;
 805         }
 806
 807         if (streq(subsystem, "module")) {
 808                 util_strscpyl(path, sizeof(path), TEST_PREFIX "/sys/module/", sysname, NULL);
 809                 if (stat(path, &statbuf) == 0)
 810                         goto found;
 811                 goto out;
 812         }
 813
 814         if (streq(subsystem, "drivers")) {
 815                 char subsys[UTIL_NAME_SIZE];
 816                 char *driver;
 817
 818                 util_strscpy(subsys, sizeof(subsys), sysname);
 819                 driver = strchr(subsys, ':');
 820                 if (driver != NULL) {
 821                         driver[0] = '\0';
 822                         driver = &driver[1];
 823
 824                         util_strscpyl(path, sizeof(path), TEST_PREFIX "/sys/subsystem/", subsys, "/drivers/", driver, NULL);
 825                         if (stat(path, &statbuf) == 0)
 826                                 goto found;
 827
 828                         util_strscpyl(path, sizeof(path), TEST_PREFIX "/sys/bus/", subsys, "/drivers/", driver, NULL);
 829                         if (stat(path, &statbuf) == 0)
 830                                 goto found;
 831                 }
 832                 goto out;
 833         }
 834
 835         util_strscpyl(path, sizeof(path), TEST_PREFIX "/sys/subsystem/", subsystem, "/devices/", sysname, NULL);
 836         if (stat(path, &statbuf) == 0)
 837                 goto found;
 838
 839         util_strscpyl(path, sizeof(path), TEST_PREFIX "/sys/bus/", subsystem, "/devices/", sysname, NULL);
 840         if (stat(path, &statbuf) == 0)
 841                 goto found;
 842
 843         util_strscpyl(path, sizeof(path), TEST_PREFIX "/sys/class/", subsystem, "/", sysname, NULL);
 844         if (stat(path, &statbuf) == 0)
 845                 goto found;
 846 out:
 847         return NULL;
 848 found:
 849         return udev_device_new_from_syspath(udev, path);
 850 }
 851
 852 /**
 853  * udev_device_new_from_environment
 854  * @udev: udev library context
 855  *
 856  * Create new udev device, and fill in information from the
 857  * current process environment. This only works reliable if
 858  * the process is called from a udev rule. It is usually used
 859  * for tools executed from IMPORT= rules.
 860  *
 861  * The initial refcount is 1, and needs to be decremented to
 862  * release the resources of the udev device.
 863  *
 864  * Returns: a new udev device, or #NULL, if it does not exist
 865  **/
 866 _public_ struct udev_device *udev_device_new_from_environment(struct udev *udev)
 867 {
 868         int i;
 869         struct udev_device *udev_device;
 870
 871         udev_device = udev_device_new(udev);
 872         if (udev_device == NULL)
 873                 return NULL;
 874         udev_device_set_info_loaded(udev_device);
 875
 876         for (i = 0; environ[i] != NULL; i++)
 877                 udev_device_add_property_from_string_parse(udev_device, environ[i]);
 878
 879         if (udev_device_add_property_from_string_parse_finish(udev_device) < 0) {
 880                 udev_dbg(udev, "missing values, invalid device\n");
 881                 udev_device_unref(udev_device);
 882                 udev_device = NULL;
 883         }
 884
 885         return udev_device;
 886 }
 887
 888 static struct udev_device *device_new_from_parent(struct udev_device *udev_device)
 889 {
 890         struct udev_device *udev_device_parent = NULL;
 891         char path[UTIL_PATH_SIZE];
 892         const char *subdir;
 893
 894         util_strscpy(path, sizeof(path), udev_device->syspath);
 895         subdir = path + strlen(TEST_PREFIX "/sys/");
 896         for (;;) {
 897                 char *pos;
 898
 899                 pos = strrchr(subdir, '/');
 900                 if (pos == NULL || pos < &subdir[2])
 901                         break;
 902                 pos[0] = '\0';
 903                 udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
 904                 if (udev_device_parent != NULL)
 905                         return udev_device_parent;
 906         }
 907         return NULL;
 908 }
 909
 910 /**
 911  * udev_device_get_parent:
 912  * @udev_device: the device to start searching from
 913  *
 914  * Find the next parent device, and fill in information from the sys
 915  * device and the udev database entry.
 916  *
 917  * The returned the device is not referenced. It is attached to the
 918  * child device, and will be cleaned up when the child device
 919  * is cleaned up.
 920  *
 921  * It is not necessarily just the upper level directory, empty or not
 922  * recognized sys directories are ignored.
 923  *
 924  * It can be called as many times as needed, without caring about
 925  * references.
 926  *
 927  * Returns: a new udev device, or #NULL, if it no parent exist.
 928  **/
 929 _public_ struct udev_device *udev_device_get_parent(struct udev_device *udev_device)
 930 {
 931         if (udev_device == NULL)
 932                 return NULL;
 933         if (!udev_device->parent_set) {
 934                 udev_device->parent_set = true;
 935                 udev_device->parent_device = device_new_from_parent(udev_device);
 936         }
 937         return udev_device->parent_device;
 938 }
 939
 940 /**
 941  * udev_device_get_parent_with_subsystem_devtype:
 942  * @udev_device: udev device to start searching from
 943  * @subsystem: the subsystem of the device
 944  * @devtype: the type (DEVTYPE) of the device
 945  *
 946  * Find the next parent device, with a matching subsystem and devtype
 947  * value, and fill in information from the sys device and the udev
 948  * database entry.
 949  *
 950  * If devtype is #NULL, only subsystem is checked, and any devtype will
 951  * match.
 952  *
 953  * The returned the device is not referenced. It is attached to the
 954  * child device, and will be cleaned up when the child device
 955  * is cleaned up.
 956  *
 957  * It can be called as many times as needed, without caring about
 958  * references.
 959  *
 960  * Returns: a new udev device, or #NULL if no matching parent exists.
 961  **/
 962 _public_ struct udev_device *udev_device_get_parent_with_subsystem_devtype(struct udev_device *udev_device, const char *subsystem, const char *devtype)
 963 {
 964         struct udev_device *parent;
 965
 966         if (subsystem == NULL)
 967                 return NULL;
 968
 969         parent = udev_device_get_parent(udev_device);
 970         while (parent != NULL) {
 971                 const char *parent_subsystem;
 972                 const char *parent_devtype;
 973
 974                 parent_subsystem = udev_device_get_subsystem(parent);
 975                 if (parent_subsystem != NULL && streq(parent_subsystem, subsystem)) {
 976                         if (devtype == NULL)
 977                                 break;
 978                         parent_devtype = udev_device_get_devtype(parent);
 979                         if (parent_devtype != NULL && streq(parent_devtype, devtype))
 980                                 break;
 981                 }
 982                 parent = udev_device_get_parent(parent);
 983         }
 984         return parent;
 985 }
 986
 987 /**
 988  * udev_device_get_udev:
 989  * @udev_device: udev device
 990  *
 991  * Retrieve the udev library context the device was created with.
 992  *
 993  * Returns: the udev library context
 994  **/
 995 _public_ struct udev *udev_device_get_udev(struct udev_device *udev_device)
 996 {
 997         if (udev_device == NULL)
 998                 return NULL;
 999         return udev_device->udev;
1000 }
1001
1002 /**
1003  * udev_device_ref:
1004  * @udev_device: udev device
1005  *
1006  * Take a reference of a udev device.
1007  *
1008  * Returns: the passed udev device
1009  **/
1010 _public_ struct udev_device *udev_device_ref(struct udev_device *udev_device)
1011 {
1012         if (udev_device == NULL)
1013                 return NULL;
1014         udev_device->refcount++;
1015         return udev_device;
1016 }
1017
1018 /**
1019  * udev_device_unref:
1020  * @udev_device: udev device
1021  *
1022  * Drop a reference of a udev device. If the refcount reaches zero,
1023  * the resources of the device will be released.
1024  *
1025  **/
1026 _public_ void udev_device_unref(struct udev_device *udev_device)
1027 {
1028         if (udev_device == NULL)
1029                 return;
1030         udev_device->refcount--;
1031         if (udev_device->refcount > 0)
1032                 return;
1033         if (udev_device->parent_device != NULL)
1034                 udev_device_unref(udev_device->parent_device);
1035         free(udev_device->syspath);
1036         free(udev_device->sysname);
1037         free(udev_device->devnode);
1038         free(udev_device->subsystem);
1039         free(udev_device->devtype);
1040         udev_list_cleanup(&udev_device->devlinks_list);
1041         udev_list_cleanup(&udev_device->properties_list);
1042         udev_list_cleanup(&udev_device->sysattr_value_list);
1043         udev_list_cleanup(&udev_device->sysattr_list);
1044         udev_list_cleanup(&udev_device->tags_list);
1045         free(udev_device->action);
1046         free(udev_device->driver);
1047         free(udev_device->devpath_old);
1048         free(udev_device->id_filename);
1049         free(udev_device->envp);
1050         free(udev_device->monitor_buf);
1051         free(udev_device);
1052 }
1053
1054 /**
1055  * udev_device_get_devpath:
1056  * @udev_device: udev device
1057  *
1058  * Retrieve the kernel devpath value of the udev device. The path
1059  * does not contain the sys mount point, and starts with a '/'.
1060  *
1061  * Returns: the devpath of the udev device
1062  **/
1063 _public_ const char *udev_device_get_devpath(struct udev_device *udev_device)
1064 {
1065         if (udev_device == NULL)
1066                 return NULL;
1067         return udev_device->devpath;
1068 }
1069
1070 /**
1071  * udev_device_get_syspath:
1072  * @udev_device: udev device
1073  *
1074  * Retrieve the sys path of the udev device. The path is an
1075  * absolute path and starts with the sys mount point.
1076  *
1077  * Returns: the sys path of the udev device
1078  **/
1079 _public_ const char *udev_device_get_syspath(struct udev_device *udev_device)
1080 {
1081         if (udev_device == NULL)
1082                 return NULL;
1083         return udev_device->syspath;
1084 }
1085
1086 /**
1087  * udev_device_get_sysname:
1088  * @udev_device: udev device
1089  *
1090  * Get the kernel device name in /sys.
1091  *
1092  * Returns: the name string of the device device
1093  **/
1094 _public_ const char *udev_device_get_sysname(struct udev_device *udev_device)
1095 {
1096         if (udev_device == NULL)
1097                 return NULL;
1098         return udev_device->sysname;
1099 }
1100
1101 /**
1102  * udev_device_get_sysnum:
1103  * @udev_device: udev device
1104  *
1105  * Get the instance number of the device.
1106  *
1107  * Returns: the trailing number string of of the device name
1108  **/
1109 _public_ const char *udev_device_get_sysnum(struct udev_device *udev_device)
1110 {
1111         if (udev_device == NULL)
1112                 return NULL;
1113         return udev_device->sysnum;
1114 }
1115
1116 /**
1117  * udev_device_get_devnode:
1118  * @udev_device: udev device
1119  *
1120  * Retrieve the device node file name belonging to the udev device.
1121  * The path is an absolute path, and starts with the device directory.
1122  *
1123  * Returns: the device node file name of the udev device, or #NULL if no device node exists
1124  **/
1125 _public_ const char *udev_device_get_devnode(struct udev_device *udev_device)
1126 {
1127         if (udev_device == NULL)
1128                 return NULL;
1129         if (udev_device->devnode != NULL)
1130                 return udev_device->devnode;
1131         if (!udev_device->info_loaded)
1132                 udev_device_read_uevent_file(udev_device);
1133         return udev_device->devnode;
1134 }
1135
1136 /**
1137  * udev_device_get_devlinks_list_entry:
1138  * @udev_device: udev device
1139  *
1140  * Retrieve the list of device links pointing to the device file of
1141  * the udev device. The next list entry can be retrieved with
1142  * udev_list_entry_get_next(), which returns #NULL if no more entries exist.
1143  * The devlink path can be retrieved from the list entry by
1144  * udev_list_entry_get_name(). The path is an absolute path, and starts with
1145  * the device directory.
1146  *
1147  * Returns: the first entry of the device node link list
1148  **/
1149 _public_ struct udev_list_entry *udev_device_get_devlinks_list_entry(struct udev_device *udev_device)
1150 {
1151         if (udev_device == NULL)
1152                 return NULL;
1153         if (!udev_device->info_loaded)
1154                 udev_device_read_db(udev_device, NULL);
1155         return udev_list_get_entry(&udev_device->devlinks_list);
1156 }
1157
1158 void udev_device_cleanup_devlinks_list(struct udev_device *udev_device)
1159 {
1160         udev_device->devlinks_uptodate = false;
1161         udev_list_cleanup(&udev_device->devlinks_list);
1162 }
1163
1164 /**
1165  * udev_device_get_properties_list_entry:
1166  * @udev_device: udev device
1167  *
1168  * Retrieve the list of key/value device properties of the udev
1169  * device. The next list entry can be retrieved with udev_list_entry_get_next(),
1170  * which returns #NULL if no more entries exist. The property name
1171  * can be retrieved from the list entry by udev_list_entry_get_name(),
1172  * the property value by udev_list_entry_get_value().
1173  *
1174  * Returns: the first entry of the property list
1175  **/
1176 _public_ struct udev_list_entry *udev_device_get_properties_list_entry(struct udev_device *udev_device)
1177 {
1178         if (udev_device == NULL)
1179                 return NULL;
1180         if (!udev_device->info_loaded) {
1181                 udev_device_read_uevent_file(udev_device);
1182                 udev_device_read_db(udev_device, NULL);
1183         }
1184         if (!udev_device->devlinks_uptodate) {
1185                 char symlinks[UTIL_PATH_SIZE];
1186                 struct udev_list_entry *list_entry;
1187
1188                 udev_device->devlinks_uptodate = true;
1189                 list_entry = udev_device_get_devlinks_list_entry(udev_device);
1190                 if (list_entry != NULL) {
1191                         char *s;
1192                         size_t l;
1193
1194                         s = symlinks;
1195                         l = util_strpcpyl(&s, sizeof(symlinks), udev_list_entry_get_name(list_entry), NULL);
1196                         udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry))
1197                                 l = util_strpcpyl(&s, l, " ", udev_list_entry_get_name(list_entry), NULL);
1198                         udev_device_add_property(udev_device, "DEVLINKS", symlinks);
1199                 }
1200         }
1201         if (!udev_device->tags_uptodate) {
1202                 udev_device->tags_uptodate = true;
1203                 if (udev_device_get_tags_list_entry(udev_device) != NULL) {
1204                         char tags[UTIL_PATH_SIZE];
1205                         struct udev_list_entry *list_entry;
1206                         char *s;
1207                         size_t l;
1208
1209                         s = tags;
1210                         l = util_strpcpyl(&s, sizeof(tags), ":", NULL);
1211                         udev_list_entry_foreach(list_entry, udev_device_get_tags_list_entry(udev_device))
1212                                 l = util_strpcpyl(&s, l, udev_list_entry_get_name(list_entry), ":", NULL);
1213                         udev_device_add_property(udev_device, "TAGS", tags);
1214                 }
1215         }
1216         return udev_list_get_entry(&udev_device->properties_list);
1217 }
1218
1219 /**
1220  * udev_device_get_action:
1221  * @udev_device: udev device
1222  *
1223  * This is only valid if the device was received through a monitor. Devices read from
1224  * sys do not have an action string. Usual actions are: add, remove, change, online,
1225  * offline.
1226  *
1227  * Returns: the kernel action value, or #NULL if there is no action value available.
1228  **/
1229 _public_ const char *udev_device_get_action(struct udev_device *udev_device)
1230 {
1231         if (udev_device == NULL)
1232                 return NULL;
1233         return udev_device->action;
1234 }
1235
1236 /**
1237  * udev_device_get_usec_since_initialized:
1238  * @udev_device: udev device
1239  *
1240  * Return the number of microseconds passed since udev set up the
1241  * device for the first time.
1242  *
1243  * This is only implemented for devices with need to store properties
1244  * in the udev database. All other devices return 0 here.
1245  *
1246  * Returns: the number of microseconds since the device was first seen.
1247  **/
1248 _public_ unsigned long long int udev_device_get_usec_since_initialized(struct udev_device *udev_device)
1249 {
1250         unsigned long long now_ts;
1251
1252         if (udev_device == NULL)
1253                 return 0;
1254         if (!udev_device->info_loaded)
1255                 udev_device_read_db(udev_device, NULL);
1256         if (udev_device->usec_initialized == 0)
1257                 return 0;
1258         now_ts = now_usec();
1259         if (now_ts == 0)
1260                 return 0;
1261         return now_ts - udev_device->usec_initialized;
1262 }
1263
1264 unsigned long long udev_device_get_usec_initialized(struct udev_device *udev_device)
1265 {
1266         return udev_device->usec_initialized;
1267 }
1268
1269 void udev_device_set_usec_initialized(struct udev_device *udev_device, unsigned long long usec_initialized)
1270 {
1271         char num[32];
1272
1273         udev_device->usec_initialized = usec_initialized;
1274         snprintf(num, sizeof(num), "%llu", usec_initialized);
1275         udev_device_add_property(udev_device, "USEC_INITIALIZED", num);
1276 }
1277
1278 /**
1279  * udev_device_get_sysattr_value:
1280  * @udev_device: udev device
1281  * @sysattr: attribute name
1282  *
1283  * The retrieved value is cached in the device. Repeated calls will return the same
1284  * value and not open the attribute again.
1285  *
1286  * Returns: the content of a sys attribute file, or #NULL if there is no sys attribute value.
1287  **/
1288 _public_ const char *udev_device_get_sysattr_value(struct udev_device *udev_device, const char *sysattr)
1289 {
1290         struct udev_list_entry *list_entry;
1291         char path[UTIL_PATH_SIZE];
1292         char value[4096];
1293         struct stat statbuf;
1294         int fd;
1295         ssize_t size;
1296         const char *val = NULL;
1297
1298         if (udev_device == NULL)
1299                 return NULL;
1300         if (sysattr == NULL)
1301                 return NULL;
1302
1303         /* look for possibly already cached result */
1304         list_entry = udev_list_get_entry(&udev_device->sysattr_value_list);
1305         list_entry = udev_list_entry_get_by_name(list_entry, sysattr);
1306         if (list_entry != NULL)
1307                 return udev_list_entry_get_value(list_entry);
1308
1309         util_strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", sysattr, NULL);
1310         if (lstat(path, &statbuf) != 0) {
1311                 udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, NULL);
1312                 goto out;
1313         }
1314
1315         if (S_ISLNK(statbuf.st_mode)) {
1316                 struct udev_device *dev;
1317
1318                 /*
1319                  * Some core links return only the last element of the target path,
1320                  * these are just values, the paths should not be exposed.
1321                  */
1322                 if (streq(sysattr, "driver") ||
1323                     streq(sysattr, "subsystem") ||
1324                     streq(sysattr, "module")) {
1325                         if (util_get_sys_core_link_value(udev_device->udev, sysattr,
1326                                                          udev_device->syspath, value, sizeof(value)) < 0)
1327                                 return NULL;
1328                         list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, value);
1329                         val = udev_list_entry_get_value(list_entry);
1330                         goto out;
1331                 }
1332
1333                 /* resolve link to a device and return its syspath */
1334                 util_strscpyl(path, sizeof(path), udev_device->syspath, "/", sysattr, NULL);
1335                 dev = udev_device_new_from_syspath(udev_device->udev, path);
1336                 if (dev != NULL) {
1337                         list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr,
1338                                                          udev_device_get_syspath(dev));
1339                         val = udev_list_entry_get_value(list_entry);
1340                         udev_device_unref(dev);
1341                 }
1342
1343                 goto out;
1344         }
1345
1346         /* skip directories */
1347         if (S_ISDIR(statbuf.st_mode))
1348                 goto out;
1349
1350         /* skip non-readable files */
1351         if ((statbuf.st_mode & S_IRUSR) == 0)
1352                 goto out;
1353
1354         /* read attribute value */
1355         fd = open(path, O_RDONLY|O_CLOEXEC);
1356         if (fd < 0)
1357                 goto out;
1358         size = read(fd, value, sizeof(value));
1359         close(fd);
1360         if (size < 0)
1361                 goto out;
1362         if (size == sizeof(value))
1363                 goto out;
1364
1365         /* got a valid value, store it in cache and return it */
1366         value[size] = '\0';
1367         util_remove_trailing_chars(value, '\n');
1368         list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, value);
1369         val = udev_list_entry_get_value(list_entry);
1370 out:
1371         return val;
1372 }
1373
1374 static int udev_device_sysattr_list_read(struct udev_device *udev_device)
1375 {
1376         struct dirent *dent;
1377         DIR *dir;
1378         int num = 0;
1379
1380         if (udev_device == NULL)
1381                 return -1;
1382         if (udev_device->sysattr_list_read)
1383                 return 0;
1384
1385         dir = opendir(udev_device_get_syspath(udev_device));
1386         if (!dir)
1387                 return -1;
1388
1389         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
1390                 char path[UTIL_PATH_SIZE];
1391                 struct stat statbuf;
1392
1393                 /* only handle symlinks and regular files */
1394                 if (dent->d_type != DT_LNK && dent->d_type != DT_REG)
1395                         continue;
1396
1397                 util_strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", dent->d_name, NULL);
1398                 if (lstat(path, &statbuf) != 0)
1399                         continue;
1400                 if ((statbuf.st_mode & S_IRUSR) == 0)
1401                         continue;
1402
1403                 udev_list_entry_add(&udev_device->sysattr_list, dent->d_name, NULL);
1404                 num++;
1405         }
1406
1407         closedir(dir);
1408         udev_device->sysattr_list_read = true;
1409
1410         return num;
1411 }
1412
1413 /**
1414  * udev_device_get_sysattr_list_entry:
1415  * @udev_device: udev device
1416  *
1417  * Retrieve the list of available sysattrs, with value being empty;
1418  * This just return all available sysfs attributes for a particular
1419  * device without reading their values.
1420  *
1421  * Returns: the first entry of the property list
1422  **/
1423 _public_ struct udev_list_entry *udev_device_get_sysattr_list_entry(struct udev_device *udev_device)
1424 {
1425         if (!udev_device->sysattr_list_read) {
1426                 int ret;
1427                 ret = udev_device_sysattr_list_read(udev_device);
1428                 if (0 > ret)
1429                         return NULL;
1430         }
1431
1432         return udev_list_get_entry(&udev_device->sysattr_list);
1433 }
1434
1435 int udev_device_set_syspath(struct udev_device *udev_device, const char *syspath)
1436 {
1437         const char *pos;
1438         size_t len;
1439
1440         free(udev_device->syspath);
1441         udev_device->syspath = strdup(syspath);
1442         if (udev_device->syspath ==  NULL)
1443                 return -ENOMEM;
1444         udev_device->devpath = udev_device->syspath + strlen(TEST_PREFIX "/sys");
1445         udev_device_add_property(udev_device, "DEVPATH", udev_device->devpath);
1446
1447         pos = strrchr(udev_device->syspath, '/');
1448         if (pos == NULL)
1449                 return -EINVAL;
1450         udev_device->sysname = strdup(&pos[1]);
1451         if (udev_device->sysname == NULL)
1452                 return -ENOMEM;
1453
1454         /* some devices have '!' in their name, change that to '/' */
1455         len = 0;
1456         while (udev_device->sysname[len] != '\0') {
1457                 if (udev_device->sysname[len] == '!')
1458                         udev_device->sysname[len] = '/';
1459                 len++;
1460         }
1461
1462         /* trailing number */
1463         while (len > 0 && isdigit(udev_device->sysname[--len]))
1464                 udev_device->sysnum = &udev_device->sysname[len];
1465
1466         /* sysname is completely numeric */
1467         if (len == 0)
1468                 udev_device->sysnum = NULL;
1469
1470         return 0;
1471 }
1472
1473 int udev_device_set_devnode(struct udev_device *udev_device, const char *devnode)
1474 {
1475         free(udev_device->devnode);
1476         if (devnode[0] != '/') {
1477                 if (asprintf(&udev_device->devnode, TEST_PREFIX "/dev/%s", devnode) < 0)
1478                         udev_device->devnode = NULL;
1479         } else {
1480                 udev_device->devnode = strdup(devnode);
1481         }
1482         if (udev_device->devnode == NULL)
1483                 return -ENOMEM;
1484         udev_device_add_property(udev_device, "DEVNAME", udev_device->devnode);
1485         return 0;
1486 }
1487
1488 int udev_device_add_devlink(struct udev_device *udev_device, const char *devlink, int unique)
1489 {
1490         struct udev_list_entry *list_entry;
1491
1492         udev_device->devlinks_uptodate = false;
1493         list_entry = udev_list_entry_add(&udev_device->devlinks_list, devlink, NULL);
1494         if (list_entry == NULL)
1495                 return -ENOMEM;
1496         if (unique)
1497                 udev_list_entry_set_num(list_entry, true);
1498         return 0;
1499 }
1500
1501 const char *udev_device_get_id_filename(struct udev_device *udev_device)
1502 {
1503         if (udev_device->id_filename == NULL) {
1504                 if (udev_device_get_subsystem(udev_device) == NULL)
1505                         return NULL;
1506
1507                 if (major(udev_device_get_devnum(udev_device)) > 0) {
1508                         /* use dev_t -- b259:131072, c254:0 */
1509                         if (asprintf(&udev_device->id_filename, "%c%u:%u",
1510                                      streq(udev_device_get_subsystem(udev_device), "block") ? 'b' : 'c',
1511                                      major(udev_device_get_devnum(udev_device)),
1512                                      minor(udev_device_get_devnum(udev_device))) < 0)
1513                                 udev_device->id_filename = NULL;
1514                 } else if (udev_device_get_ifindex(udev_device) > 0) {
1515                         /* use netdev ifindex -- n3 */
1516                         if (asprintf(&udev_device->id_filename, "n%u", udev_device_get_ifindex(udev_device)) < 0)
1517                                 udev_device->id_filename = NULL;
1518                 } else {
1519                         /*
1520                          * use $subsys:$syname -- pci:0000:00:1f.2
1521                          * sysname() has '!' translated, get it from devpath
1522                          */
1523                         const char *sysname;
1524                         sysname = strrchr(udev_device->devpath, '/');
1525                         if (sysname == NULL)
1526                                 return NULL;
1527                         sysname = &sysname[1];
1528                         if (asprintf(&udev_device->id_filename, "+%s:%s", udev_device_get_subsystem(udev_device), sysname) < 0)
1529                                 udev_device->id_filename = NULL;
1530                 }
1531         }
1532         return udev_device->id_filename;
1533 }
1534
1535 /**
1536  * udev_device_get_is_initialized:
1537  * @udev_device: udev device
1538  *
1539  * Check if udev has already handled the device and has set up
1540  * device node permissions and context, or has renamed a network
1541  * device.
1542  *
1543  * This is only implemented for devices with a device node
1544  * or network interfaces. All other devices return 1 here.
1545  *
1546  * Returns: 1 if the device is set up. 0 otherwise.
1547  **/
1548 _public_ int udev_device_get_is_initialized(struct udev_device *udev_device)
1549 {
1550         if (!udev_device->info_loaded)
1551                 udev_device_read_db(udev_device, NULL);
1552         return udev_device->is_initialized;
1553 }
1554
1555 void udev_device_set_is_initialized(struct udev_device *udev_device)
1556 {
1557         udev_device->is_initialized = true;
1558 }
1559
1560 int udev_device_add_tag(struct udev_device *udev_device, const char *tag)
1561 {
1562         if (strchr(tag, ':') != NULL || strchr(tag, ' ') != NULL)
1563                 return -EINVAL;
1564         udev_device->tags_uptodate = false;
1565         if (udev_list_entry_add(&udev_device->tags_list, tag, NULL) != NULL)
1566                 return 0;
1567         return -ENOMEM;
1568 }
1569
1570 void udev_device_cleanup_tags_list(struct udev_device *udev_device)
1571 {
1572         udev_device->tags_uptodate = false;
1573         udev_list_cleanup(&udev_device->tags_list);
1574 }
1575
1576 /**
1577  * udev_device_get_tags_list_entry:
1578  * @udev_device: udev device
1579  *
1580  * Retrieve the list of tags attached to the udev device. The next
1581  * list entry can be retrieved with udev_list_entry_get_next(),
1582  * which returns #NULL if no more entries exist. The tag string
1583  * can be retrieved from the list entry by udev_list_entry_get_name().
1584  *
1585  * Returns: the first entry of the tag list
1586  **/
1587 _public_ struct udev_list_entry *udev_device_get_tags_list_entry(struct udev_device *udev_device)
1588 {
1589         if (udev_device == NULL)
1590                 return NULL;
1591         if (!udev_device->info_loaded)
1592                 udev_device_read_db(udev_device, NULL);
1593         return udev_list_get_entry(&udev_device->tags_list);
1594 }
1595
1596 /**
1597  * udev_device_has_tag:
1598  * @udev_device: udev device
1599  * @tag: tag name
1600  *
1601  * Check if a given device has a certain tag associated.
1602  *
1603  * Returns: 1 if the tag is found. 0 otherwise.
1604  **/
1605 _public_ int udev_device_has_tag(struct udev_device *udev_device, const char *tag)
1606 {
1607         struct udev_list_entry *list_entry;
1608
1609         if (udev_device == NULL)
1610                 return false;
1611         if (!udev_device->info_loaded)
1612                 udev_device_read_db(udev_device, NULL);
1613         list_entry = udev_device_get_tags_list_entry(udev_device);
1614         if (udev_list_entry_get_by_name(list_entry, tag) != NULL)
1615                 return true;
1616         return false;
1617 }
1618
1619 #define ENVP_SIZE                        128
1620 #define MONITOR_BUF_SIZE                4096
1621 static int update_envp_monitor_buf(struct udev_device *udev_device)
1622 {
1623         struct udev_list_entry *list_entry;
1624         char *s;
1625         size_t l;
1626         unsigned int i;
1627
1628         /* monitor buffer of property strings */
1629         free(udev_device->monitor_buf);
1630         udev_device->monitor_buf_len = 0;
1631         udev_device->monitor_buf = malloc(MONITOR_BUF_SIZE);
1632         if (udev_device->monitor_buf == NULL)
1633                 return -ENOMEM;
1634
1635         /* envp array, strings will point into monitor buffer */
1636         if (udev_device->envp == NULL)
1637                 udev_device->envp = malloc(sizeof(char *) * ENVP_SIZE);
1638         if (udev_device->envp == NULL)
1639                 return -ENOMEM;
1640
1641         i = 0;
1642         s = udev_device->monitor_buf;
1643         l = MONITOR_BUF_SIZE;
1644         udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) {
1645                 const char *key;
1646
1647                 key = udev_list_entry_get_name(list_entry);
1648                 /* skip private variables */
1649                 if (key[0] == '.')
1650                         continue;
1651
1652                 /* add string to envp array */
1653                 udev_device->envp[i++] = s;
1654                 if (i+1 >= ENVP_SIZE)
1655                         return -EINVAL;
1656
1657                 /* add property string to monitor buffer */
1658                 l = util_strpcpyl(&s, l, key, "=", udev_list_entry_get_value(list_entry), NULL);
1659                 if (l == 0)
1660                         return -EINVAL;
1661                 /* advance past the trailing '\0' that util_strpcpyl() guarantees */
1662                 s++;
1663                 l--;
1664         }
1665         udev_device->envp[i] = NULL;
1666         udev_device->monitor_buf_len = s - udev_device->monitor_buf;
1667         udev_device->envp_uptodate = true;
1668         return 0;
1669 }
1670
1671 char **udev_device_get_properties_envp(struct udev_device *udev_device)
1672 {
1673         if (!udev_device->envp_uptodate)
1674                 if (update_envp_monitor_buf(udev_device) != 0)
1675                         return NULL;
1676         return udev_device->envp;
1677 }
1678
1679 ssize_t udev_device_get_properties_monitor_buf(struct udev_device *udev_device, const char **buf)
1680 {
1681         if (!udev_device->envp_uptodate)
1682                 if (update_envp_monitor_buf(udev_device) != 0)
1683                         return -EINVAL;
1684         *buf = udev_device->monitor_buf;
1685         return udev_device->monitor_buf_len;
1686 }
1687
1688 int udev_device_set_action(struct udev_device *udev_device, const char *action)
1689 {
1690         free(udev_device->action);
1691         udev_device->action = strdup(action);
1692         if (udev_device->action == NULL)
1693                 return -ENOMEM;
1694         udev_device_add_property(udev_device, "ACTION", udev_device->action);
1695         return 0;
1696 }
1697
1698 int udev_device_get_devlink_priority(struct udev_device *udev_device)
1699 {
1700         if (!udev_device->info_loaded)
1701                 udev_device_read_db(udev_device, NULL);
1702         return udev_device->devlink_priority;
1703 }
1704
1705 int udev_device_set_devlink_priority(struct udev_device *udev_device, int prio)
1706 {
1707          udev_device->devlink_priority = prio;
1708         return 0;
1709 }
1710
1711 int udev_device_get_watch_handle(struct udev_device *udev_device)
1712 {
1713         if (!udev_device->info_loaded)
1714                 udev_device_read_db(udev_device, NULL);
1715         return udev_device->watch_handle;
1716 }
1717
1718 int udev_device_set_watch_handle(struct udev_device *udev_device, int handle)
1719 {
1720         udev_device->watch_handle = handle;
1721         return 0;
1722 }
1723
1724 bool udev_device_get_db_persist(struct udev_device *udev_device)
1725 {
1726         return udev_device->db_persist;
1727 }
1728
1729 void udev_device_set_db_persist(struct udev_device *udev_device)
1730 {
1731         udev_device->db_persist = true;
1732 }