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 *knodename;
  61         char *id_filename;
  62         char **envp;
  63         char *monitor_buf;
  64         size_t monitor_buf_len;
  65         struct udev_list devlinks_list;
  66         struct udev_list properties_list;
  67         struct udev_list sysattr_value_list;
  68         struct udev_list sysattr_list;
  69         struct udev_list tags_list;
  70         unsigned long long int seqnum;
  71         unsigned long long int usec_initialized;
  72         int timeout;
  73         int devlink_priority;
  74         int refcount;
  75         dev_t devnum;
  76         int ifindex;
  77         int watch_handle;
  78         int maj, min;
  79         bool parent_set;
  80         bool subsystem_set;
  81         bool devtype_set;
  82         bool devlinks_uptodate;
  83         bool envp_uptodate;
  84         bool tags_uptodate;
  85         bool driver_set;
  86         bool info_loaded;
  87         bool db_loaded;
  88         bool uevent_loaded;
  89         bool is_initialized;
  90         bool sysattr_list_read;
  91         bool db_persist;
  92 };
  93
  94 /**
  95  * udev_device_get_devnum:
  96  * @udev_device: udev device
  97  *
  98  * This is only valid if the device was received through a monitor. Devices read from
  99  * sys do not have a sequence number.
 100  *
 101  * Returns: the kernel event sequence number, or 0 if there is no sequence number available.
 102  **/
 103 UDEV_EXPORT unsigned long long int udev_device_get_seqnum(struct udev_device *udev_device)
 104 {
 105         if (udev_device == NULL)
 106                 return 0;
 107         return udev_device->seqnum;
 108 }
 109
 110 static int udev_device_set_seqnum(struct udev_device *udev_device, unsigned long long int seqnum)
 111 {
 112         char num[32];
 113
 114         udev_device->seqnum = seqnum;
 115         snprintf(num, sizeof(num), "%llu", seqnum);
 116         udev_device_add_property(udev_device, "SEQNUM", num);
 117         return 0;
 118 }
 119
 120 int udev_device_get_ifindex(struct udev_device *udev_device)
 121 {
 122         if (!udev_device->info_loaded)
 123                 udev_device_read_uevent_file(udev_device);
 124         return udev_device->ifindex;
 125 }
 126
 127 static int udev_device_set_ifindex(struct udev_device *udev_device, int ifindex)
 128 {
 129         char num[32];
 130
 131         udev_device->ifindex = ifindex;
 132         snprintf(num, sizeof(num), "%u", ifindex);
 133         udev_device_add_property(udev_device, "IFINDEX", num);
 134         return 0;
 135 }
 136
 137 /**
 138  * udev_device_get_devnum:
 139  * @udev_device: udev device
 140  *
 141  * Returns: the device major/minor number.
 142  **/
 143 UDEV_EXPORT 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 int udev_device_get_timeout(struct udev_device *udev_device)
 166 {
 167         return udev_device->timeout;
 168 }
 169
 170 static int udev_device_set_timeout(struct udev_device *udev_device, int timeout)
 171 {
 172         char num[32];
 173
 174         udev_device->timeout = timeout;
 175         snprintf(num, sizeof(num), "%u", timeout);
 176         udev_device_add_property(udev_device, "TIMEOUT", num);
 177         return 0;
 178 }
 179
 180 const char *udev_device_get_knodename(struct udev_device *udev_device)
 181 {
 182         return udev_device->knodename;
 183 }
 184
 185 static int udev_device_set_knodename(struct udev_device *udev_device, const char *knodename)
 186 {
 187         free(udev_device->knodename);
 188         udev_device->knodename = strdup(knodename);
 189         if (udev_device->knodename == NULL)
 190                 return -ENOMEM;
 191         /* do not overwrite the udev property with the kernel property */
 192         if (udev_device->devnode == NULL)
 193                 udev_device_add_property(udev_device, "DEVNAME", udev_device->knodename);
 194         return 0;
 195 }
 196
 197 const char *udev_device_get_devpath_old(struct udev_device *udev_device)
 198 {
 199         return udev_device->devpath_old;
 200 }
 201
 202 static int udev_device_set_devpath_old(struct udev_device *udev_device, const char *devpath_old)
 203 {
 204         const char *pos;
 205
 206         free(udev_device->devpath_old);
 207         udev_device->devpath_old = strdup(devpath_old);
 208         if (udev_device->devpath_old == NULL)
 209                 return -ENOMEM;
 210         udev_device_add_property(udev_device, "DEVPATH_OLD", udev_device->devpath_old);
 211
 212         pos = strrchr(udev_device->devpath_old, '/');
 213         if (pos == NULL)
 214                 return -EINVAL;
 215         return 0;
 216 }
 217
 218 /**
 219  * udev_device_get_driver:
 220  * @udev_device: udev device
 221  *
 222  * Returns: the driver string, or #NULL if there is no driver attached.
 223  **/
 224 UDEV_EXPORT const char *udev_device_get_driver(struct udev_device *udev_device)
 225 {
 226         char driver[UTIL_NAME_SIZE];
 227
 228         if (udev_device == NULL)
 229                 return NULL;
 230         if (!udev_device->driver_set) {
 231                 udev_device->driver_set = true;
 232                 if (util_get_sys_driver(udev_device->udev, udev_device->syspath, driver, sizeof(driver)) > 0)
 233                         udev_device->driver = strdup(driver);
 234         }
 235         return udev_device->driver;
 236 }
 237
 238 static int udev_device_set_driver(struct udev_device *udev_device, const char *driver)
 239 {
 240         free(udev_device->driver);
 241         udev_device->driver = strdup(driver);
 242         if (udev_device->driver == NULL)
 243                 return -ENOMEM;
 244         udev_device->driver_set = true;
 245         udev_device_add_property(udev_device, "DRIVER", udev_device->driver);
 246         return 0;
 247 }
 248
 249 /**
 250  * udev_device_get_devtype:
 251  * @udev_device: udev device
 252  *
 253  * Retrieve the devtype string of the udev device.
 254  *
 255  * Returns: the devtype name of the udev device, or #NULL if it can not be determined
 256  **/
 257 UDEV_EXPORT const char *udev_device_get_devtype(struct udev_device *udev_device)
 258 {
 259         if (udev_device == NULL)
 260                 return NULL;
 261         if (!udev_device->devtype_set) {
 262                 udev_device->devtype_set = true;
 263                 udev_device_read_uevent_file(udev_device);
 264         }
 265         return udev_device->devtype;
 266 }
 267
 268 static int udev_device_set_devtype(struct udev_device *udev_device, const char *devtype)
 269 {
 270         free(udev_device->devtype);
 271         udev_device->devtype = strdup(devtype);
 272         if (udev_device->devtype == NULL)
 273                 return -ENOMEM;
 274         udev_device->devtype_set = true;
 275         udev_device_add_property(udev_device, "DEVTYPE", udev_device->devtype);
 276         return 0;
 277 }
 278
 279 static int udev_device_set_subsystem(struct udev_device *udev_device, const char *subsystem)
 280 {
 281         free(udev_device->subsystem);
 282         udev_device->subsystem = strdup(subsystem);
 283         if (udev_device->subsystem == NULL)
 284                 return -ENOMEM;
 285         udev_device->subsystem_set = true;
 286         udev_device_add_property(udev_device, "SUBSYSTEM", udev_device->subsystem);
 287         return 0;
 288 }
 289
 290 /**
 291  * udev_device_get_subsystem:
 292  * @udev_device: udev device
 293  *
 294  * Retrieve the subsystem string of the udev device. The string does not
 295  * contain any "/".
 296  *
 297  * Returns: the subsystem name of the udev device, or #NULL if it can not be determined
 298  **/
 299 UDEV_EXPORT const char *udev_device_get_subsystem(struct udev_device *udev_device)
 300 {
 301         char subsystem[UTIL_NAME_SIZE];
 302
 303         if (udev_device == NULL)
 304                 return NULL;
 305         if (!udev_device->subsystem_set) {
 306                 udev_device->subsystem_set = true;
 307                 /* read "subsystem" link */
 308                 if (util_get_sys_subsystem(udev_device->udev, udev_device->syspath, subsystem, sizeof(subsystem)) > 0) {
 309                         udev_device_set_subsystem(udev_device, subsystem);
 310                         return udev_device->subsystem;
 311                 }
 312                 /* implicit names */
 313                 if (strncmp(udev_device->devpath, "/module/", 8) == 0) {
 314                         udev_device_set_subsystem(udev_device, "module");
 315                         return udev_device->subsystem;
 316                 }
 317                 if (strstr(udev_device->devpath, "/drivers/") != NULL) {
 318                         udev_device_set_subsystem(udev_device, "drivers");
 319                         return udev_device->subsystem;
 320                 }
 321                 if (strncmp(udev_device->devpath, "/subsystem/", 11) == 0 ||
 322                     strncmp(udev_device->devpath, "/class/", 7) == 0 ||
 323                     strncmp(udev_device->devpath, "/bus/", 5) == 0) {
 324                         udev_device_set_subsystem(udev_device, "subsystem");
 325                         return udev_device->subsystem;
 326                 }
 327         }
 328         return udev_device->subsystem;
 329 }
 330
 331 mode_t udev_device_get_devnode_mode(struct udev_device *udev_device)
 332 {
 333         if (!udev_device->info_loaded)
 334                 udev_device_read_uevent_file(udev_device);
 335         return udev_device->devnode_mode;
 336 }
 337
 338 static int udev_device_set_devnode_mode(struct udev_device *udev_device, mode_t mode)
 339 {
 340         char num[32];
 341
 342         udev_device->devnode_mode = mode;
 343         snprintf(num, sizeof(num), "%#o", mode);
 344         udev_device_add_property(udev_device, "DEVMODE", num);
 345         return 0;
 346 }
 347
 348 struct udev_list_entry *udev_device_add_property(struct udev_device *udev_device, const char *key, const char *value)
 349 {
 350         udev_device->envp_uptodate = false;
 351         if (value == NULL) {
 352                 struct udev_list_entry *list_entry;
 353
 354                 list_entry = udev_device_get_properties_list_entry(udev_device);
 355                 list_entry = udev_list_entry_get_by_name(list_entry, key);
 356                 if (list_entry != NULL)
 357                         udev_list_entry_delete(list_entry);
 358                 return NULL;
 359         }
 360         return udev_list_entry_add(&udev_device->properties_list, key, value);
 361 }
 362
 363 static struct udev_list_entry *udev_device_add_property_from_string(struct udev_device *udev_device, const char *property)
 364 {
 365         char name[UTIL_LINE_SIZE];
 366         char *val;
 367
 368         util_strscpy(name, sizeof(name), property);
 369         val = strchr(name, '=');
 370         if (val == NULL)
 371                 return NULL;
 372         val[0] = '\0';
 373         val = &val[1];
 374         if (val[0] == '\0')
 375                 val = NULL;
 376         return udev_device_add_property(udev_device, name, val);
 377 }
 378
 379 /*
 380  * parse property string, and if needed, update internal values accordingly
 381  *
 382  * udev_device_add_property_from_string_parse_finish() needs to be
 383  * called after adding properties, and its return value checked
 384  *
 385  * udev_device_set_info_loaded() needs to be set, to avoid trying
 386  * to use a device without a DEVPATH set
 387  */
 388 void udev_device_add_property_from_string_parse(struct udev_device *udev_device, const char *property)
 389 {
 390         if (strncmp(property, "DEVPATH=", 8) == 0) {
 391                 char path[UTIL_PATH_SIZE];
 392
 393                 util_strscpyl(path, sizeof(path), udev_get_sys_path(udev_device->udev), &property[8], NULL);
 394                 udev_device_set_syspath(udev_device, path);
 395         } else if (strncmp(property, "SUBSYSTEM=", 10) == 0) {
 396                 udev_device_set_subsystem(udev_device, &property[10]);
 397         } else if (strncmp(property, "DEVTYPE=", 8) == 0) {
 398                 udev_device_set_devtype(udev_device, &property[8]);
 399         } else if (strncmp(property, "DEVNAME=", 8) == 0) {
 400                 if (property[8] == '/')
 401                         udev_device_set_devnode(udev_device, &property[8]);
 402                 else
 403                         udev_device_set_knodename(udev_device, &property[8]);
 404         } else if (strncmp(property, "DEVLINKS=", 9) == 0) {
 405                 char devlinks[UTIL_PATH_SIZE];
 406                 char *slink;
 407                 char *next;
 408
 409                 util_strscpy(devlinks, sizeof(devlinks), &property[9]);
 410                 slink = devlinks;
 411                 next = strchr(slink, ' ');
 412                 while (next != NULL) {
 413                         next[0] = '\0';
 414                         udev_device_add_devlink(udev_device, slink, 0);
 415                         slink = &next[1];
 416                         next = strchr(slink, ' ');
 417                 }
 418                 if (slink[0] != '\0')
 419                         udev_device_add_devlink(udev_device, slink, 0);
 420         } else if (strncmp(property, "TAGS=", 5) == 0) {
 421                 char tags[UTIL_PATH_SIZE];
 422                 char *next;
 423
 424                 util_strscpy(tags, sizeof(tags), &property[5]);
 425                 next = strchr(tags, ':');
 426                 if (next != NULL) {
 427                         next++;
 428                         while (next[0] != '\0') {
 429                                 char *tag;
 430
 431                                 tag = next;
 432                                 next = strchr(tag, ':');
 433                                 if (next == NULL)
 434                                         break;
 435                                 next[0] = '\0';
 436                                 next++;
 437                                 udev_device_add_tag(udev_device, tag);
 438                         }
 439                 }
 440         } else if (strncmp(property, "DRIVER=", 7) == 0) {
 441                 udev_device_set_driver(udev_device, &property[7]);
 442         } else if (strncmp(property, "ACTION=", 7) == 0) {
 443                 udev_device_set_action(udev_device, &property[7]);
 444         } else if (strncmp(property, "MAJOR=", 6) == 0) {
 445                 udev_device->maj = strtoull(&property[6], NULL, 10);
 446         } else if (strncmp(property, "MINOR=", 6) == 0) {
 447                 udev_device->min = strtoull(&property[6], NULL, 10);
 448         } else if (strncmp(property, "DEVPATH_OLD=", 12) == 0) {
 449                 udev_device_set_devpath_old(udev_device, &property[12]);
 450         } else if (strncmp(property, "SEQNUM=", 7) == 0) {
 451                 udev_device_set_seqnum(udev_device, strtoull(&property[7], NULL, 10));
 452         } else if (strncmp(property, "TIMEOUT=", 8) == 0) {
 453                 udev_device_set_timeout(udev_device, strtoull(&property[8], NULL, 10));
 454         } else if (strncmp(property, "IFINDEX=", 8) == 0) {
 455                 udev_device_set_ifindex(udev_device, strtoull(&property[8], NULL, 10));
 456         } else if (strncmp(property, "DEVMODE=", 8) == 0) {
 457                 udev_device_set_devnode_mode(udev_device, strtoul(&property[8], NULL, 8));
 458         } else {
 459                 udev_device_add_property_from_string(udev_device, property);
 460         }
 461 }
 462
 463 int udev_device_add_property_from_string_parse_finish(struct udev_device *udev_device)
 464 {
 465         if (udev_device->maj > 0)
 466                 udev_device_set_devnum(udev_device, makedev(udev_device->maj, udev_device->min));
 467         udev_device->maj = 0;
 468         udev_device->min = 0;
 469
 470         if (udev_device->devpath == NULL || udev_device->subsystem == NULL)
 471                 return -EINVAL;
 472         return 0;
 473 }
 474
 475 /**
 476  * udev_device_get_property_value:
 477  * @udev_device: udev device
 478  * @key: property name
 479  *
 480  * Returns: the value of a device property, or #NULL if there is no such property.
 481  **/
 482 UDEV_EXPORT const char *udev_device_get_property_value(struct udev_device *udev_device, const char *key)
 483 {
 484         struct udev_list_entry *list_entry;
 485
 486         if (udev_device == NULL)
 487                 return NULL;
 488         if (key == NULL)
 489                 return NULL;
 490
 491         list_entry = udev_device_get_properties_list_entry(udev_device);
 492         list_entry = udev_list_entry_get_by_name(list_entry, key);
 493         return udev_list_entry_get_value(list_entry);
 494 }
 495
 496 int udev_device_read_db(struct udev_device *udev_device, const char *dbfile)
 497 {
 498         char filename[UTIL_PATH_SIZE];
 499         char line[UTIL_LINE_SIZE];
 500         FILE *f;
 501
 502         /* providing a database file will always force-load it */
 503         if (dbfile == NULL) {
 504                 const char *id;
 505
 506                 if (udev_device->db_loaded)
 507                         return 0;
 508                 udev_device->db_loaded = true;
 509
 510                 id = udev_device_get_id_filename(udev_device);
 511                 if (id == NULL)
 512                         return -1;
 513                 util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev_device->udev), "/data/", id, NULL);
 514                 dbfile = filename;
 515         }
 516
 517         f = fopen(dbfile, "re");
 518         if (f == NULL) {
 519                 info(udev_device->udev, "no db file to read %s: %m\n", dbfile);
 520                 return -1;
 521         }
 522         udev_device->is_initialized = true;
 523
 524         while (fgets(line, sizeof(line), f)) {
 525                 ssize_t len;
 526                 const char *val;
 527                 struct udev_list_entry *entry;
 528
 529                 len = strlen(line);
 530                 if (len < 4)
 531                         break;
 532                 line[len-1] = '\0';
 533                 val = &line[2];
 534                 switch(line[0]) {
 535                 case 'N':
 536                         util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev_device->udev), "/", val, NULL);
 537                         udev_device_set_devnode(udev_device, filename);
 538                         break;
 539                 case 'S':
 540                         util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev_device->udev), "/", val, NULL);
 541                         udev_device_add_devlink(udev_device, filename, 0);
 542                         break;
 543                 case 'L':
 544                         udev_device_set_devlink_priority(udev_device, atoi(val));
 545                         break;
 546                 case 'E':
 547                         entry = udev_device_add_property_from_string(udev_device, val);
 548                         udev_list_entry_set_num(entry, true);
 549                         break;
 550                 case 'G':
 551                         udev_device_add_tag(udev_device, val);
 552                         break;
 553                 case 'W':
 554                         udev_device_set_watch_handle(udev_device, atoi(val));
 555                         break;
 556                 case 'I':
 557                         udev_device_set_usec_initialized(udev_device, strtoull(val, NULL, 10));
 558                         break;
 559                 }
 560         }
 561         fclose(f);
 562
 563         info(udev_device->udev, "device %p filled with db file data\n", udev_device);
 564         return 0;
 565 }
 566
 567 int udev_device_read_uevent_file(struct udev_device *udev_device)
 568 {
 569         char filename[UTIL_PATH_SIZE];
 570         FILE *f;
 571         char line[UTIL_LINE_SIZE];
 572         int maj = 0;
 573         int min = 0;
 574
 575         if (udev_device->uevent_loaded)
 576                 return 0;
 577
 578         util_strscpyl(filename, sizeof(filename), udev_device->syspath, "/uevent", NULL);
 579         f = fopen(filename, "re");
 580         if (f == NULL)
 581                 return -1;
 582         udev_device->uevent_loaded = true;
 583
 584         while (fgets(line, sizeof(line), f)) {
 585                 char *pos;
 586
 587                 pos = strchr(line, '\n');
 588                 if (pos == NULL)
 589                         continue;
 590                 pos[0] = '\0';
 591
 592                 if (strncmp(line, "DEVTYPE=", 8) == 0)
 593                         udev_device_set_devtype(udev_device, &line[8]);
 594                 else if (strncmp(line, "MAJOR=", 6) == 0)
 595                         maj = strtoull(&line[6], NULL, 10);
 596                 else if (strncmp(line, "MINOR=", 6) == 0)
 597                         min = strtoull(&line[6], NULL, 10);
 598                 else if (strncmp(line, "IFINDEX=", 8) == 0)
 599                         udev_device_set_ifindex(udev_device, strtoull(&line[8], NULL, 10));
 600                 else if (strncmp(line, "DEVNAME=", 8) == 0)
 601                         udev_device_set_knodename(udev_device, &line[8]);
 602                 else if (strncmp(line, "DEVMODE=", 8) == 0)
 603                         udev_device->devnode_mode = strtoul(&line[8], NULL, 8);
 604
 605                 udev_device_add_property_from_string(udev_device, line);
 606         }
 607
 608         udev_device->devnum = makedev(maj, min);
 609         fclose(f);
 610         return 0;
 611 }
 612
 613 void udev_device_set_info_loaded(struct udev_device *device)
 614 {
 615         device->info_loaded = true;
 616 }
 617
 618 struct udev_device *udev_device_new(struct udev *udev)
 619 {
 620         struct udev_device *udev_device;
 621         struct udev_list_entry *list_entry;
 622
 623         if (udev == NULL)
 624                 return NULL;
 625
 626         udev_device = calloc(1, sizeof(struct udev_device));
 627         if (udev_device == NULL)
 628                 return NULL;
 629         udev_device->refcount = 1;
 630         udev_device->udev = udev;
 631         udev_list_init(udev, &udev_device->devlinks_list, true);
 632         udev_list_init(udev, &udev_device->properties_list, true);
 633         udev_list_init(udev, &udev_device->sysattr_value_list, true);
 634         udev_list_init(udev, &udev_device->sysattr_list, false);
 635         udev_list_init(udev, &udev_device->tags_list, true);
 636         udev_device->timeout = -1;
 637         udev_device->watch_handle = -1;
 638         /* copy global properties */
 639         udev_list_entry_foreach(list_entry, udev_get_properties_list_entry(udev))
 640                 udev_device_add_property(udev_device,
 641                                          udev_list_entry_get_name(list_entry),
 642                                          udev_list_entry_get_value(list_entry));
 643         dbg(udev_device->udev, "udev_device: %p created\n", udev_device);
 644         return udev_device;
 645 }
 646
 647 /**
 648  * udev_device_new_from_syspath:
 649  * @udev: udev library context
 650  * @syspath: sys device path including sys directory
 651  *
 652  * Create new udev device, and fill in information from the sys
 653  * device and the udev database entry. The syspath is the absolute
 654  * path to the device, including the sys mount point.
 655  *
 656  * The initial refcount is 1, and needs to be decremented to
 657  * release the resources of the udev device.
 658  *
 659  * Returns: a new udev device, or #NULL, if it does not exist
 660  **/
 661 UDEV_EXPORT struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *syspath)
 662 {
 663         size_t len;
 664         const char *subdir;
 665         char path[UTIL_PATH_SIZE];
 666         char *pos;
 667         struct stat statbuf;
 668         struct udev_device *udev_device;
 669
 670         if (udev == NULL)
 671                 return NULL;
 672         if (syspath == NULL)
 673                 return NULL;
 674
 675         /* path starts in sys */
 676         len = strlen(udev_get_sys_path(udev));
 677         if (strncmp(syspath, udev_get_sys_path(udev), len) != 0) {
 678                 info(udev, "not in sys :%s\n", syspath);
 679                 return NULL;
 680         }
 681
 682         /* path is not a root directory */
 683         subdir = &syspath[len+1];
 684         pos = strrchr(subdir, '/');
 685         if (pos == NULL || pos[1] == '\0' || pos < &subdir[2]) {
 686                 dbg(udev, "not a subdir :%s\n", syspath);
 687                 return NULL;
 688         }
 689
 690         /* resolve possible symlink to real path */
 691         util_strscpy(path, sizeof(path), syspath);
 692         util_resolve_sys_link(udev, path, sizeof(path));
 693
 694         if (strncmp(&path[len], "/devices/", 9) == 0) {
 695                 char file[UTIL_PATH_SIZE];
 696
 697                 /* all "devices" require a "uevent" file */
 698                 util_strscpyl(file, sizeof(file), path, "/uevent", NULL);
 699                 if (stat(file, &statbuf) != 0) {
 700                         dbg(udev, "not a device: %s\n", syspath);
 701                         return NULL;
 702                 }
 703         } else {
 704                 /* everything else just needs to be a directory */
 705                 if (stat(path, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode)) {
 706                         dbg(udev, "directory not found: %s\n", syspath);
 707                         return NULL;
 708                 }
 709         }
 710
 711         udev_device = udev_device_new(udev);
 712         if (udev_device == NULL)
 713                 return NULL;
 714
 715         udev_device_set_syspath(udev_device, path);
 716         info(udev, "device %p has devpath '%s'\n", udev_device, udev_device_get_devpath(udev_device));
 717
 718         return udev_device;
 719 }
 720
 721 /**
 722  * udev_device_new_from_devnum:
 723  * @udev: udev library context
 724  * @type: char or block device
 725  * @devnum: device major/minor number
 726  *
 727  * Create new udev device, and fill in information from the sys
 728  * device and the udev database entry. The device is looked-up
 729  * by its major/minor number and type. Character and block device
 730  * numbers are not unique across the two types.
 731  *
 732  * The initial refcount is 1, and needs to be decremented to
 733  * release the resources of the udev device.
 734  *
 735  * Returns: a new udev device, or #NULL, if it does not exist
 736  **/
 737 UDEV_EXPORT struct udev_device *udev_device_new_from_devnum(struct udev *udev, char type, dev_t devnum)
 738 {
 739         char path[UTIL_PATH_SIZE];
 740         const char *type_str;
 741
 742         if (type == 'b')
 743                 type_str = "block";
 744         else if (type == 'c')
 745                 type_str = "char";
 746         else
 747                 return NULL;
 748
 749         /* use /sys/dev/{block,char}/<maj>:<min> link */
 750         snprintf(path, sizeof(path), "%s/dev/%s/%u:%u",
 751                  udev_get_sys_path(udev), type_str, major(devnum), minor(devnum));
 752         return udev_device_new_from_syspath(udev, path);
 753 }
 754
 755 struct udev_device *udev_device_new_from_id_filename(struct udev *udev, char *id)
 756 {
 757         char type;
 758         int maj, min;
 759         char subsys[UTIL_PATH_SIZE];
 760         char *sysname;
 761
 762         switch(id[0]) {
 763         case 'b':
 764         case 'c':
 765                 if (sscanf(id, "%c%i:%i", &type, &maj, &min) != 3)
 766                         return NULL;
 767                 return udev_device_new_from_devnum(udev, type, makedev(maj, min));
 768         case 'n': {
 769                 int sk;
 770                 struct ifreq ifr;
 771                 struct udev_device *dev;
 772                 int ifindex;
 773
 774                 ifindex = strtoul(&id[1], NULL, 10);
 775                 if (ifindex <= 0)
 776                         return NULL;
 777
 778                 sk = socket(PF_INET, SOCK_DGRAM, 0);
 779                 if (sk < 0)
 780                         return NULL;
 781                 memset(&ifr, 0x00, sizeof(struct ifreq));
 782                 ifr.ifr_ifindex = ifindex;
 783                 if (ioctl(sk, SIOCGIFNAME, &ifr) != 0) {
 784                         close(sk);
 785                         return NULL;
 786                 }
 787                 close(sk);
 788
 789                 dev = udev_device_new_from_subsystem_sysname(udev, "net", ifr.ifr_name);
 790                 if (dev == NULL)
 791                         return NULL;
 792                 if (udev_device_get_ifindex(dev) == ifindex)
 793                         return dev;
 794                 udev_device_unref(dev);
 795                 return NULL;
 796         }
 797         case '+':
 798                 util_strscpy(subsys, sizeof(subsys), &id[1]);
 799                 sysname = strchr(subsys, ':');
 800                 if (sysname == NULL)
 801                         return NULL;
 802                 sysname[0] = '\0';
 803                 sysname = &sysname[1];
 804                 return udev_device_new_from_subsystem_sysname(udev, subsys, sysname);
 805         default:
 806                 return NULL;
 807         }
 808 }
 809
 810 /**
 811  * udev_device_new_from_subsystem_sysname:
 812  * @udev: udev library context
 813  * @subsystem: the subsystem of the device
 814  * @sysname: the name of the device
 815  *
 816  * Create new udev device, and fill in information from the sys device
 817  * and the udev database entry. The device is looked up by the subsystem
 818  * and name string of the device, like "mem" / "zero", or "block" / "sda".
 819  *
 820  * The initial refcount is 1, and needs to be decremented to
 821  * release the resources of the udev device.
 822  *
 823  * Returns: a new udev device, or #NULL, if it does not exist
 824  **/
 825 UDEV_EXPORT struct udev_device *udev_device_new_from_subsystem_sysname(struct udev *udev, const char *subsystem, const char *sysname)
 826 {
 827         char path_full[UTIL_PATH_SIZE];
 828         char *path;
 829         size_t l;
 830         struct stat statbuf;
 831
 832         path = path_full;
 833         l = util_strpcpyl(&path, sizeof(path_full), udev_get_sys_path(udev), NULL);
 834
 835         if (strcmp(subsystem, "subsystem") == 0) {
 836                 util_strscpyl(path, l, "/subsystem/", sysname, NULL);
 837                 if (stat(path_full, &statbuf) == 0)
 838                         goto found;
 839
 840                 util_strscpyl(path, l, "/bus/", sysname, NULL);
 841                 if (stat(path_full, &statbuf) == 0)
 842                         goto found;
 843
 844                 util_strscpyl(path, l, "/class/", sysname, NULL);
 845                 if (stat(path_full, &statbuf) == 0)
 846                         goto found;
 847                 goto out;
 848         }
 849
 850         if (strcmp(subsystem, "module") == 0) {
 851                 util_strscpyl(path, l, "/module/", sysname, NULL);
 852                 if (stat(path_full, &statbuf) == 0)
 853                         goto found;
 854                 goto out;
 855         }
 856
 857         if (strcmp(subsystem, "drivers") == 0) {
 858                 char subsys[UTIL_NAME_SIZE];
 859                 char *driver;
 860
 861                 util_strscpy(subsys, sizeof(subsys), sysname);
 862                 driver = strchr(subsys, ':');
 863                 if (driver != NULL) {
 864                         driver[0] = '\0';
 865                         driver = &driver[1];
 866
 867                         util_strscpyl(path, l, "/subsystem/", subsys, "/drivers/", driver, NULL);
 868                         if (stat(path_full, &statbuf) == 0)
 869                                 goto found;
 870
 871                         util_strscpyl(path, l, "/bus/", subsys, "/drivers/", driver, NULL);
 872                         if (stat(path_full, &statbuf) == 0)
 873                                 goto found;
 874                 }
 875                 goto out;
 876         }
 877
 878         util_strscpyl(path, l, "/subsystem/", subsystem, "/devices/", sysname, NULL);
 879         if (stat(path_full, &statbuf) == 0)
 880                 goto found;
 881
 882         util_strscpyl(path, l, "/bus/", subsystem, "/devices/", sysname, NULL);
 883         if (stat(path_full, &statbuf) == 0)
 884                 goto found;
 885
 886         util_strscpyl(path, l, "/class/", subsystem, "/", sysname, NULL);
 887         if (stat(path_full, &statbuf) == 0)
 888                 goto found;
 889 out:
 890         return NULL;
 891 found:
 892         return udev_device_new_from_syspath(udev, path_full);
 893 }
 894
 895 /**
 896  * udev_device_new_from_environment
 897  * @udev: udev library context
 898  *
 899  * Create new udev device, and fill in information from the
 900  * current process environment. This only works reliable if
 901  * the process is called from a udev rule. It is usually used
 902  * for tools executed from IMPORT= rules.
 903  *
 904  * The initial refcount is 1, and needs to be decremented to
 905  * release the resources of the udev device.
 906  *
 907  * Returns: a new udev device, or #NULL, if it does not exist
 908  **/
 909 UDEV_EXPORT struct udev_device *udev_device_new_from_environment(struct udev *udev)
 910 {
 911         int i;
 912         struct udev_device *udev_device;
 913
 914         udev_device = udev_device_new(udev);
 915         if (udev_device == NULL)
 916                 return NULL;
 917         udev_device_set_info_loaded(udev_device);
 918
 919         for (i = 0; environ[i] != NULL; i++)
 920                 udev_device_add_property_from_string_parse(udev_device, environ[i]);
 921
 922         if (udev_device_add_property_from_string_parse_finish(udev_device) < 0) {
 923                 info(udev, "missing values, invalid device\n");
 924                 udev_device_unref(udev_device);
 925                 udev_device = NULL;
 926         }
 927
 928         return udev_device;
 929 }
 930
 931 static struct udev_device *device_new_from_parent(struct udev_device *udev_device)
 932 {
 933         struct udev_device *udev_device_parent = NULL;
 934         char path[UTIL_PATH_SIZE];
 935         const char *subdir;
 936
 937         util_strscpy(path, sizeof(path), udev_device->syspath);
 938         subdir = &path[strlen(udev_get_sys_path(udev_device->udev))+1];
 939         for (;;) {
 940                 char *pos;
 941
 942                 pos = strrchr(subdir, '/');
 943                 if (pos == NULL || pos < &subdir[2])
 944                         break;
 945                 pos[0] = '\0';
 946                 udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
 947                 if (udev_device_parent != NULL)
 948                         return udev_device_parent;
 949         }
 950         return NULL;
 951 }
 952
 953 /**
 954  * udev_device_get_parent:
 955  * @udev_device: the device to start searching from
 956  *
 957  * Find the next parent device, and fill in information from the sys
 958  * device and the udev database entry.
 959  *
 960  * The returned the device is not referenced. It is attached to the
 961  * child device, and will be cleaned up when the child device
 962  * is cleaned up.
 963  *
 964  * It is not necessarily just the upper level directory, empty or not
 965  * recognized sys directories are ignored.
 966  *
 967  * It can be called as many times as needed, without caring about
 968  * references.
 969  *
 970  * Returns: a new udev device, or #NULL, if it no parent exist.
 971  **/
 972 UDEV_EXPORT struct udev_device *udev_device_get_parent(struct udev_device *udev_device)
 973 {
 974         if (udev_device == NULL)
 975                 return NULL;
 976         if (!udev_device->parent_set) {
 977                 udev_device->parent_set = true;
 978                 udev_device->parent_device = device_new_from_parent(udev_device);
 979         }
 980         if (udev_device->parent_device != NULL)
 981                 dbg(udev_device->udev, "returning existing parent %p\n", udev_device->parent_device);
 982         return udev_device->parent_device;
 983 }
 984
 985 /**
 986  * udev_device_get_parent_with_subsystem_devtype:
 987  * @udev_device: udev device to start searching from
 988  * @subsystem: the subsystem of the device
 989  * @devtype: the type (DEVTYPE) of the device
 990  *
 991  * Find the next parent device, with a matching subsystem and devtype
 992  * value, and fill in information from the sys device and the udev
 993  * database entry.
 994  *
 995  * If devtype is #NULL, only subsystem is checked, and any devtype will
 996  * match.
 997  *
 998  * The returned the device is not referenced. It is attached to the
 999  * child device, and will be cleaned up when the child device
1000  * is cleaned up.
1001  *
1002  * It can be called as many times as needed, without caring about
1003  * references.
1004  *
1005  * Returns: a new udev device, or #NULL if no matching parent exists.
1006  **/
1007 UDEV_EXPORT struct udev_device *udev_device_get_parent_with_subsystem_devtype(struct udev_device *udev_device, const char *subsystem, const char *devtype)
1008 {
1009         struct udev_device *parent;
1010
1011         if (subsystem == NULL)
1012                 return NULL;
1013
1014         parent = udev_device_get_parent(udev_device);
1015         while (parent != NULL) {
1016                 const char *parent_subsystem;
1017                 const char *parent_devtype;
1018
1019                 parent_subsystem = udev_device_get_subsystem(parent);
1020                 if (parent_subsystem != NULL && strcmp(parent_subsystem, subsystem) == 0) {
1021                         if (devtype == NULL)
1022                                 break;
1023                         parent_devtype = udev_device_get_devtype(parent);
1024                         if (parent_devtype != NULL && strcmp(parent_devtype, devtype) == 0)
1025                                 break;
1026                 }
1027                 parent = udev_device_get_parent(parent);
1028         }
1029         return parent;
1030 }
1031
1032 /**
1033  * udev_device_get_udev:
1034  * @udev_device: udev device
1035  *
1036  * Retrieve the udev library context the device was created with.
1037  *
1038  * Returns: the udev library context
1039  **/
1040 UDEV_EXPORT struct udev *udev_device_get_udev(struct udev_device *udev_device)
1041 {
1042         if (udev_device == NULL)
1043                 return NULL;
1044         return udev_device->udev;
1045 }
1046
1047 /**
1048  * udev_device_ref:
1049  * @udev_device: udev device
1050  *
1051  * Take a reference of a udev device.
1052  *
1053  * Returns: the passed udev device
1054  **/
1055 UDEV_EXPORT struct udev_device *udev_device_ref(struct udev_device *udev_device)
1056 {
1057         if (udev_device == NULL)
1058                 return NULL;
1059         udev_device->refcount++;
1060         return udev_device;
1061 }
1062
1063 /**
1064  * udev_device_unref:
1065  * @udev_device: udev device
1066  *
1067  * Drop a reference of a udev device. If the refcount reaches zero,
1068  * the resources of the device will be released.
1069  *
1070  **/
1071 UDEV_EXPORT void udev_device_unref(struct udev_device *udev_device)
1072 {
1073         if (udev_device == NULL)
1074                 return;
1075         udev_device->refcount--;
1076         if (udev_device->refcount > 0)
1077                 return;
1078         if (udev_device->parent_device != NULL)
1079                 udev_device_unref(udev_device->parent_device);
1080         free(udev_device->syspath);
1081         free(udev_device->sysname);
1082         free(udev_device->devnode);
1083         free(udev_device->subsystem);
1084         free(udev_device->devtype);
1085         udev_list_cleanup(&udev_device->devlinks_list);
1086         udev_list_cleanup(&udev_device->properties_list);
1087         udev_list_cleanup(&udev_device->sysattr_value_list);
1088         udev_list_cleanup(&udev_device->sysattr_list);
1089         udev_list_cleanup(&udev_device->tags_list);
1090         free(udev_device->action);
1091         free(udev_device->driver);
1092         free(udev_device->devpath_old);
1093         free(udev_device->knodename);
1094         free(udev_device->id_filename);
1095         free(udev_device->envp);
1096         free(udev_device->monitor_buf);
1097         dbg(udev_device->udev, "udev_device: %p released\n", udev_device);
1098         free(udev_device);
1099 }
1100
1101 /**
1102  * udev_device_get_devpath:
1103  * @udev_device: udev device
1104  *
1105  * Retrieve the kernel devpath value of the udev device. The path
1106  * does not contain the sys mount point, and starts with a '/'.
1107  *
1108  * Returns: the devpath of the udev device
1109  **/
1110 UDEV_EXPORT const char *udev_device_get_devpath(struct udev_device *udev_device)
1111 {
1112         if (udev_device == NULL)
1113                 return NULL;
1114         return udev_device->devpath;
1115 }
1116
1117 /**
1118  * udev_device_get_syspath:
1119  * @udev_device: udev device
1120  *
1121  * Retrieve the sys path of the udev device. The path is an
1122  * absolute path and starts with the sys mount point.
1123  *
1124  * Returns: the sys path of the udev device
1125  **/
1126 UDEV_EXPORT const char *udev_device_get_syspath(struct udev_device *udev_device)
1127 {
1128         if (udev_device == NULL)
1129                 return NULL;
1130         return udev_device->syspath;
1131 }
1132
1133 /**
1134  * udev_device_get_sysname:
1135  * @udev_device: udev device
1136  *
1137  * Returns: the sys name of the device device
1138  **/
1139 UDEV_EXPORT const char *udev_device_get_sysname(struct udev_device *udev_device)
1140 {
1141         if (udev_device == NULL)
1142                 return NULL;
1143         return udev_device->sysname;
1144 }
1145
1146 /**
1147  * udev_device_get_sysnum:
1148  * @udev_device: udev device
1149  *
1150  * Returns: the trailing number of of the device name
1151  **/
1152 UDEV_EXPORT const char *udev_device_get_sysnum(struct udev_device *udev_device)
1153 {
1154         if (udev_device == NULL)
1155                 return NULL;
1156         return udev_device->sysnum;
1157 }
1158
1159 /**
1160  * udev_device_get_devnode:
1161  * @udev_device: udev device
1162  *
1163  * Retrieve the device node file name belonging to the udev device.
1164  * The path is an absolute path, and starts with the device directory.
1165  *
1166  * Returns: the device node file name of the udev device, or #NULL if no device node exists
1167  **/
1168 UDEV_EXPORT const char *udev_device_get_devnode(struct udev_device *udev_device)
1169 {
1170         if (udev_device == NULL)
1171                 return NULL;
1172         if (!udev_device->info_loaded) {
1173                 udev_device_read_uevent_file(udev_device);
1174                 udev_device_read_db(udev_device, NULL);
1175         }
1176
1177         /* we might get called before we handled an event and have a db, use the kernel-provided name */
1178         if (udev_device->devnode == NULL && udev_device_get_knodename(udev_device) != NULL) {
1179                 char filename[UTIL_NAME_SIZE];
1180
1181                 util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev_device->udev), "/",
1182                               udev_device_get_knodename(udev_device), NULL);
1183                 udev_device_set_devnode(udev_device, filename);
1184                 return udev_device->devnode;
1185         }
1186
1187         return udev_device->devnode;
1188 }
1189
1190 /**
1191  * udev_device_get_devlinks_list_entry:
1192  * @udev_device: udev device
1193  *
1194  * Retrieve the list of device links pointing to the device file of
1195  * the udev device. The next list entry can be retrieved with
1196  * udev_list_entry_next(), which returns #NULL if no more entries exist.
1197  * The devlink path can be retrieved from the list entry by
1198  * udev_list_entry_get_name(). The path is an absolute path, and starts with
1199  * the device directory.
1200  *
1201  * Returns: the first entry of the device node link list
1202  **/
1203 UDEV_EXPORT struct udev_list_entry *udev_device_get_devlinks_list_entry(struct udev_device *udev_device)
1204 {
1205         if (udev_device == NULL)
1206                 return NULL;
1207         if (!udev_device->info_loaded)
1208                 udev_device_read_db(udev_device, NULL);
1209         return udev_list_get_entry(&udev_device->devlinks_list);
1210 }
1211
1212 void udev_device_cleanup_devlinks_list(struct udev_device *udev_device)
1213 {
1214         udev_device->devlinks_uptodate = false;
1215         udev_list_cleanup(&udev_device->devlinks_list);
1216 }
1217
1218 /**
1219  * udev_device_get_properties_list_entry:
1220  * @udev_device: udev device
1221  *
1222  * Retrieve the list of key/value device properties of the udev
1223  * device. The next list entry can be retrieved with udev_list_entry_next(),
1224  * which returns #NULL if no more entries exist. The property name
1225  * can be retrieved from the list entry by udev_list_get_name(),
1226  * the property value by udev_list_get_value().
1227  *
1228  * Returns: the first entry of the property list
1229  **/
1230 UDEV_EXPORT struct udev_list_entry *udev_device_get_properties_list_entry(struct udev_device *udev_device)
1231 {
1232         if (udev_device == NULL)
1233                 return NULL;
1234         if (!udev_device->info_loaded) {
1235                 udev_device_read_uevent_file(udev_device);
1236                 udev_device_read_db(udev_device, NULL);
1237         }
1238         if (!udev_device->devlinks_uptodate) {
1239                 char symlinks[UTIL_PATH_SIZE];
1240                 struct udev_list_entry *list_entry;
1241
1242                 udev_device->devlinks_uptodate = true;
1243                 list_entry = udev_device_get_devlinks_list_entry(udev_device);
1244                 if (list_entry != NULL) {
1245                         char *s;
1246                         size_t l;
1247
1248                         s = symlinks;
1249                         l = util_strpcpyl(&s, sizeof(symlinks), udev_list_entry_get_name(list_entry), NULL);
1250                         udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry))
1251                                 l = util_strpcpyl(&s, l, " ", udev_list_entry_get_name(list_entry), NULL);
1252                         udev_device_add_property(udev_device, "DEVLINKS", symlinks);
1253                 }
1254         }
1255         if (!udev_device->tags_uptodate) {
1256                 udev_device->tags_uptodate = true;
1257                 if (udev_device_get_tags_list_entry(udev_device) != NULL) {
1258                         char tags[UTIL_PATH_SIZE];
1259                         struct udev_list_entry *list_entry;
1260                         char *s;
1261                         size_t l;
1262
1263                         s = tags;
1264                         l = util_strpcpyl(&s, sizeof(tags), ":", NULL);
1265                         udev_list_entry_foreach(list_entry, udev_device_get_tags_list_entry(udev_device))
1266                                 l = util_strpcpyl(&s, l, udev_list_entry_get_name(list_entry), ":", NULL);
1267                         udev_device_add_property(udev_device, "TAGS", tags);
1268                 }
1269         }
1270         return udev_list_get_entry(&udev_device->properties_list);
1271 }
1272
1273 /**
1274  * udev_device_get_action:
1275  * @udev_device: udev device
1276  *
1277  * This is only valid if the device was received through a monitor. Devices read from
1278  * sys do not have an action string. Usual actions are: add, remove, change, online,
1279  * offline.
1280  *
1281  * Returns: the kernel action value, or #NULL if there is no action value available.
1282  **/
1283 UDEV_EXPORT const char *udev_device_get_action(struct udev_device *udev_device)
1284 {
1285         if (udev_device == NULL)
1286                 return NULL;
1287         return udev_device->action;
1288 }
1289
1290 /**
1291  * udev_device_get_usec_since_initialized:
1292  * @udev_device: udev device
1293  *
1294  * Return the number of microseconds passed since udev set up the
1295  * device for the first time.
1296  *
1297  * This is only implemented for devices with need to store properties
1298  * in the udev database. All other devices return 0 here.
1299  *
1300  * Returns: the number of microseconds since the device was first seen.
1301  **/
1302 UDEV_EXPORT unsigned long long int udev_device_get_usec_since_initialized(struct udev_device *udev_device)
1303 {
1304         unsigned long long now;
1305
1306         if (udev_device == NULL)
1307                 return 0;
1308         if (!udev_device->info_loaded)
1309                 udev_device_read_db(udev_device, NULL);
1310         if (udev_device->usec_initialized == 0)
1311                 return 0;
1312         now = now_usec();
1313         if (now == 0)
1314                 return 0;
1315         return now - udev_device->usec_initialized;
1316 }
1317
1318 unsigned long long udev_device_get_usec_initialized(struct udev_device *udev_device)
1319 {
1320         return udev_device->usec_initialized;
1321 }
1322
1323 void udev_device_set_usec_initialized(struct udev_device *udev_device, unsigned long long usec_initialized)
1324 {
1325         udev_device->usec_initialized = usec_initialized;
1326 }
1327
1328 /**
1329  * udev_device_get_sysattr_value:
1330  * @udev_device: udev device
1331  * @sysattr: attribute name
1332  *
1333  * The retrieved value is cached in the device. Repeated calls will return the same
1334  * value and not open the attribute again.
1335  *
1336  * Returns: the content of a sys attribute file, or #NULL if there is no sys attribute value.
1337  **/
1338 UDEV_EXPORT const char *udev_device_get_sysattr_value(struct udev_device *udev_device, const char *sysattr)
1339 {
1340         struct udev_list_entry *list_entry;
1341         char path[UTIL_PATH_SIZE];
1342         char value[4096];
1343         struct stat statbuf;
1344         int fd;
1345         ssize_t size;
1346         const char *val = NULL;
1347
1348         if (udev_device == NULL)
1349                 return NULL;
1350         if (sysattr == NULL)
1351                 return NULL;
1352
1353         /* look for possibly already cached result */
1354         list_entry = udev_list_get_entry(&udev_device->sysattr_value_list);
1355         list_entry = udev_list_entry_get_by_name(list_entry, sysattr);
1356         if (list_entry != NULL) {
1357                 dbg(udev_device->udev, "got '%s' (%s) from cache\n",
1358                     sysattr, udev_list_entry_get_value(list_entry));
1359                 return udev_list_entry_get_value(list_entry);
1360         }
1361
1362         util_strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", sysattr, NULL);
1363         if (lstat(path, &statbuf) != 0) {
1364                 dbg(udev_device->udev, "no attribute '%s', keep negative entry\n", path);
1365                 udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, NULL);
1366                 goto out;
1367         }
1368
1369         if (S_ISLNK(statbuf.st_mode)) {
1370                 char target[UTIL_NAME_SIZE];
1371                 int len;
1372                 char *pos;
1373
1374                 /* some core links return the last element of the target path */
1375                 if (strcmp(sysattr, "driver") != 0 &&
1376                     strcmp(sysattr, "subsystem") != 0 &&
1377                     strcmp(sysattr, "module") != 0)
1378                         goto out;
1379
1380                 len = readlink(path, target, sizeof(target));
1381                 if (len <= 0 || len == sizeof(target))
1382                         goto out;
1383                 target[len] = '\0';
1384
1385                 pos = strrchr(target, '/');
1386                 if (pos != NULL) {
1387                         pos = &pos[1];
1388                         dbg(udev_device->udev, "cache '%s' with link value '%s'\n", sysattr, pos);
1389                         list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, pos);
1390                         val = udev_list_entry_get_value(list_entry);
1391                 }
1392
1393                 goto out;
1394         }
1395
1396         /* skip directories */
1397         if (S_ISDIR(statbuf.st_mode))
1398                 goto out;
1399
1400         /* skip non-readable files */
1401         if ((statbuf.st_mode & S_IRUSR) == 0)
1402                 goto out;
1403
1404         /* read attribute value */
1405         fd = open(path, O_RDONLY|O_CLOEXEC);
1406         if (fd < 0) {
1407                 dbg(udev_device->udev, "attribute '%s' can not be opened\n", path);
1408                 goto out;
1409         }
1410         size = read(fd, value, sizeof(value));
1411         close(fd);
1412         if (size < 0)
1413                 goto out;
1414         if (size == sizeof(value))
1415                 goto out;
1416
1417         /* got a valid value, store it in cache and return it */
1418         value[size] = '\0';
1419         util_remove_trailing_chars(value, '\n');
1420         dbg(udev_device->udev, "'%s' has attribute value '%s'\n", path, value);
1421         list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, value);
1422         val = udev_list_entry_get_value(list_entry);
1423 out:
1424         return val;
1425 }
1426
1427 static int udev_device_sysattr_list_read(struct udev_device *udev_device)
1428 {
1429         struct dirent *dent;
1430         DIR *dir;
1431         int num = 0;
1432
1433         if (udev_device == NULL)
1434                 return -1;
1435         if (udev_device->sysattr_list_read)
1436                 return 0;
1437
1438         dir = opendir(udev_device_get_syspath(udev_device));
1439         if (!dir) {
1440                 dbg(udev_device->udev, "sysfs dir '%s' can not be opened\n",
1441                                 udev_device_get_syspath(udev_device));
1442                 return -1;
1443         }
1444
1445         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
1446                 char path[UTIL_PATH_SIZE];
1447                 struct stat statbuf;
1448
1449                 /* only handle symlinks and regular files */
1450                 if (dent->d_type != DT_LNK && dent->d_type != DT_REG)
1451                         continue;
1452
1453                 util_strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", dent->d_name, NULL);
1454                 if (lstat(path, &statbuf) != 0)
1455                         continue;
1456                 if ((statbuf.st_mode & S_IRUSR) == 0)
1457                         continue;
1458
1459                 udev_list_entry_add(&udev_device->sysattr_list, dent->d_name, NULL);
1460                 num++;
1461         }
1462
1463         closedir(dir);
1464         dbg(udev_device->udev, "found %d sysattrs for '%s'\n", num, udev_device_get_syspath(udev_device));
1465         udev_device->sysattr_list_read = true;
1466
1467         return num;
1468 }
1469
1470 /**
1471  * udev_device_get_sysattr_list_entry:
1472  * @udev_device: udev device
1473  *
1474  * Retrieve the list of available sysattrs, with value being empty;
1475  * This just return all available sysfs attributes for a particular
1476  * device without reading their values.
1477  *
1478  * Returns: the first entry of the property list
1479  **/
1480 UDEV_EXPORT struct udev_list_entry *udev_device_get_sysattr_list_entry(struct udev_device *udev_device)
1481 {
1482         if (!udev_device->sysattr_list_read) {
1483                 int ret;
1484                 ret = udev_device_sysattr_list_read(udev_device);
1485                 if (0 > ret)
1486                         return NULL;
1487         }
1488
1489         return udev_list_get_entry(&udev_device->sysattr_list);
1490 }
1491
1492 int udev_device_set_syspath(struct udev_device *udev_device, const char *syspath)
1493 {
1494         const char *pos;
1495         size_t len;
1496
1497         free(udev_device->syspath);
1498         udev_device->syspath = strdup(syspath);
1499         if (udev_device->syspath ==  NULL)
1500                 return -ENOMEM;
1501         udev_device->devpath = &udev_device->syspath[strlen(udev_get_sys_path(udev_device->udev))];
1502         udev_device_add_property(udev_device, "DEVPATH", udev_device->devpath);
1503
1504         pos = strrchr(udev_device->syspath, '/');
1505         if (pos == NULL)
1506                 return -EINVAL;
1507         udev_device->sysname = strdup(&pos[1]);
1508         if (udev_device->sysname == NULL)
1509                 return -ENOMEM;
1510
1511         /* some devices have '!' in their name, change that to '/' */
1512         len = 0;
1513         while (udev_device->sysname[len] != '\0') {
1514                 if (udev_device->sysname[len] == '!')
1515                         udev_device->sysname[len] = '/';
1516                 len++;
1517         }
1518
1519         /* trailing number */
1520         while (len > 0 && isdigit(udev_device->sysname[--len]))
1521                 udev_device->sysnum = &udev_device->sysname[len];
1522
1523         /* sysname is completely numeric */
1524         if (len == 0)
1525                 udev_device->sysnum = NULL;
1526
1527         return 0;
1528 }
1529
1530 int udev_device_set_devnode(struct udev_device *udev_device, const char *devnode)
1531 {
1532         free(udev_device->devnode);
1533         udev_device->devnode = strdup(devnode);
1534         if (udev_device->devnode == NULL)
1535                 return -ENOMEM;
1536         udev_device_add_property(udev_device, "DEVNAME", udev_device->devnode);
1537         return 0;
1538 }
1539
1540 int udev_device_add_devlink(struct udev_device *udev_device, const char *devlink, int unique)
1541 {
1542         struct udev_list_entry *list_entry;
1543
1544         udev_device->devlinks_uptodate = false;
1545         list_entry = udev_list_entry_add(&udev_device->devlinks_list, devlink, NULL);
1546         if (list_entry == NULL)
1547                 return -ENOMEM;
1548         if (unique)
1549                 udev_list_entry_set_num(list_entry, true);
1550         return 0;
1551 }
1552
1553 const char *udev_device_get_id_filename(struct udev_device *udev_device)
1554 {
1555         if (udev_device->id_filename == NULL) {
1556                 if (udev_device_get_subsystem(udev_device) == NULL)
1557                         return NULL;
1558
1559                 if (major(udev_device_get_devnum(udev_device)) > 0) {
1560                         /* use dev_t -- b259:131072, c254:0 */
1561                         if (asprintf(&udev_device->id_filename, "%c%u:%u",
1562                                      strcmp(udev_device_get_subsystem(udev_device), "block") == 0 ? 'b' : 'c',
1563                                      major(udev_device_get_devnum(udev_device)),
1564                                      minor(udev_device_get_devnum(udev_device))) < 0)
1565                                 udev_device->id_filename = NULL;
1566                 } else if (udev_device_get_ifindex(udev_device) > 0) {
1567                         /* use netdev ifindex -- n3 */
1568                         if (asprintf(&udev_device->id_filename, "n%u", udev_device_get_ifindex(udev_device)) < 0)
1569                                 udev_device->id_filename = NULL;
1570                 } else {
1571                         /*
1572                          * use $subsys:$syname -- pci:0000:00:1f.2
1573                          * sysname() has '!' translated, get it from devpath
1574                          */
1575                         const char *sysname;
1576                         sysname = strrchr(udev_device->devpath, '/');
1577                         if (sysname == NULL)
1578                                 return NULL;
1579                         sysname = &sysname[1];
1580                         if (asprintf(&udev_device->id_filename, "+%s:%s", udev_device_get_subsystem(udev_device), sysname) < 0)
1581                                 udev_device->id_filename = NULL;
1582                 }
1583         }
1584         return udev_device->id_filename;
1585 }
1586
1587 /**
1588  * udev_device_get_is_initialized:
1589  * @udev_device: udev device
1590  *
1591  * Check if udev has already handled the device and has set up
1592  * device node permissions and context, or has renamed a network
1593  * device.
1594  *
1595  * This is only implemented for devices with a device node
1596  * or network interfaces. All other devices return 1 here.
1597  *
1598  * Returns: 1 if the device is set up. 0 otherwise.
1599  **/
1600 UDEV_EXPORT int udev_device_get_is_initialized(struct udev_device *udev_device)
1601 {
1602         if (!udev_device->info_loaded)
1603                 udev_device_read_db(udev_device, NULL);
1604         return udev_device->is_initialized;
1605 }
1606
1607 void udev_device_set_is_initialized(struct udev_device *udev_device)
1608 {
1609         udev_device->is_initialized = true;
1610 }
1611
1612 int udev_device_add_tag(struct udev_device *udev_device, const char *tag)
1613 {
1614         if (strchr(tag, ':') != NULL || strchr(tag, ' ') != NULL)
1615                 return -EINVAL;
1616         udev_device->tags_uptodate = false;
1617         if (udev_list_entry_add(&udev_device->tags_list, tag, NULL) != NULL)
1618                 return 0;
1619         return -ENOMEM;
1620 }
1621
1622 void udev_device_cleanup_tags_list(struct udev_device *udev_device)
1623 {
1624         udev_device->tags_uptodate = false;
1625         udev_list_cleanup(&udev_device->tags_list);
1626 }
1627
1628 /**
1629  * udev_device_get_tags_list_entry:
1630  * @udev_device: udev device
1631  *
1632  * Retrieve the list of tags attached to the udev device. The next
1633  * list entry can be retrieved with udev_list_entry_next(),
1634  * which returns #NULL if no more entries exist. The tag string
1635  * can be retrieved from the list entry by udev_list_get_name().
1636  *
1637  * Returns: the first entry of the tag list
1638  **/
1639 UDEV_EXPORT struct udev_list_entry *udev_device_get_tags_list_entry(struct udev_device *udev_device)
1640 {
1641         if (udev_device == NULL)
1642                 return NULL;
1643         if (!udev_device->info_loaded)
1644                 udev_device_read_db(udev_device, NULL);
1645         return udev_list_get_entry(&udev_device->tags_list);
1646 }
1647
1648 UDEV_EXPORT int udev_device_has_tag(struct udev_device *udev_device, const char *tag)
1649 {
1650         struct udev_list_entry *list_entry;
1651
1652         if (udev_device == NULL)
1653                 return false;
1654         if (!udev_device->info_loaded)
1655                 udev_device_read_db(udev_device, NULL);
1656         list_entry = udev_device_get_tags_list_entry(udev_device);
1657         if (udev_list_entry_get_by_name(list_entry, tag) != NULL)
1658                 return true;
1659         return false;
1660 }
1661
1662 #define ENVP_SIZE                       128
1663 #define MONITOR_BUF_SIZE                4096
1664 static int update_envp_monitor_buf(struct udev_device *udev_device)
1665 {
1666         struct udev_list_entry *list_entry;
1667         char *s;
1668         size_t l;
1669         unsigned int i;
1670
1671         /* monitor buffer of property strings */
1672         free(udev_device->monitor_buf);
1673         udev_device->monitor_buf_len = 0;
1674         udev_device->monitor_buf = malloc(MONITOR_BUF_SIZE);
1675         if (udev_device->monitor_buf == NULL)
1676                 return -ENOMEM;
1677
1678         /* envp array, strings will point into monitor buffer */
1679         if (udev_device->envp == NULL)
1680                 udev_device->envp = malloc(sizeof(char *) * ENVP_SIZE);
1681         if (udev_device->envp == NULL)
1682                 return -ENOMEM;
1683
1684         i = 0;
1685         s = udev_device->monitor_buf;
1686         l = MONITOR_BUF_SIZE;
1687         udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) {
1688                 const char *key;
1689
1690                 key = udev_list_entry_get_name(list_entry);
1691                 /* skip private variables */
1692                 if (key[0] == '.')
1693                         continue;
1694
1695                 /* add string to envp array */
1696                 udev_device->envp[i++] = s;
1697                 if (i+1 >= ENVP_SIZE)
1698                         return -EINVAL;
1699
1700                 /* add property string to monitor buffer */
1701                 l = util_strpcpyl(&s, l, key, "=", udev_list_entry_get_value(list_entry), NULL);
1702                 if (l == 0)
1703                         return -EINVAL;
1704                 /* advance past the trailing '\0' that util_strpcpyl() guarantees */
1705                 s++;
1706                 l--;
1707         }
1708         udev_device->envp[i] = NULL;
1709         udev_device->monitor_buf_len = s - udev_device->monitor_buf;
1710         udev_device->envp_uptodate = true;
1711         dbg(udev_device->udev, "filled envp/monitor buffer, %u properties, %zu bytes\n",
1712             i, udev_device->monitor_buf_len);
1713         return 0;
1714 }
1715
1716 char **udev_device_get_properties_envp(struct udev_device *udev_device)
1717 {
1718         if (!udev_device->envp_uptodate)
1719                 if (update_envp_monitor_buf(udev_device) != 0)
1720                         return NULL;
1721         return udev_device->envp;
1722 }
1723
1724 ssize_t udev_device_get_properties_monitor_buf(struct udev_device *udev_device, const char **buf)
1725 {
1726         if (!udev_device->envp_uptodate)
1727                 if (update_envp_monitor_buf(udev_device) != 0)
1728                         return -EINVAL;
1729         *buf = udev_device->monitor_buf;
1730         return udev_device->monitor_buf_len;
1731 }
1732
1733 int udev_device_set_action(struct udev_device *udev_device, const char *action)
1734 {
1735         free(udev_device->action);
1736         udev_device->action = strdup(action);
1737         if (udev_device->action == NULL)
1738                 return -ENOMEM;
1739         udev_device_add_property(udev_device, "ACTION", udev_device->action);
1740         return 0;
1741 }
1742
1743 int udev_device_get_devlink_priority(struct udev_device *udev_device)
1744 {
1745         if (!udev_device->info_loaded)
1746                 udev_device_read_db(udev_device, NULL);
1747         return udev_device->devlink_priority;
1748 }
1749
1750 int udev_device_set_devlink_priority(struct udev_device *udev_device, int prio)
1751 {
1752          udev_device->devlink_priority = prio;
1753         return 0;
1754 }
1755
1756 int udev_device_get_watch_handle(struct udev_device *udev_device)
1757 {
1758         if (!udev_device->info_loaded)
1759                 udev_device_read_db(udev_device, NULL);
1760         return udev_device->watch_handle;
1761 }
1762
1763 int udev_device_set_watch_handle(struct udev_device *udev_device, int handle)
1764 {
1765         udev_device->watch_handle = handle;
1766         return 0;
1767 }
1768
1769 bool udev_device_get_db_persist(struct udev_device *udev_device)
1770 {
1771         return udev_device->db_persist;
1772 }
1773
1774 void udev_device_set_db_persist(struct udev_device *udev_device)
1775 {
1776         udev_device->db_persist = true;
1777 }