src/libudev/libudev-device.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2008-2012 Kay Sievers <kay@vrfy.org>
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <stddef.h>
  23 #include <unistd.h>
  24 #include <stdbool.h>
  25 #include <errno.h>
  26 #include <string.h>
  27 #include <dirent.h>
  28 #include <fcntl.h>
  29 #include <ctype.h>
  30 #include <net/if.h>
  31 #include <sys/stat.h>
  32 #include <sys/ioctl.h>
  33 #include <sys/socket.h>
  34 #include <linux/sockios.h>
  35
  36 #include "libudev.h"
  37 #include "libudev-private.h"
  38
  39 static int udev_device_set_devnode(struct udev_device *udev_device, const char *devnode);
  40
  41 /**
  42  * SECTION:libudev-device
  43  * @short_description: kernel sys devices
  44  *
  45  * Representation of kernel sys devices. Devices are uniquely identified
  46  * by their syspath, every device has exactly one path in the kernel sys
  47  * filesystem. Devices usually belong to a kernel subsystem, and have
  48  * a unique name inside that subsystem.
  49  */
  50
  51 /**
  52  * udev_device:
  53  *
  54  * Opaque object representing one kernel sys device.
  55  */
  56 struct udev_device {
  57         struct udev *udev;
  58         struct udev_device *parent_device;
  59         char *syspath;
  60         const char *devpath;
  61         char *sysname;
  62         const char *sysnum;
  63         char *devnode;
  64         mode_t devnode_mode;
  65         uid_t devnode_uid;
  66         gid_t devnode_gid;
  67         char *subsystem;
  68         char *devtype;
  69         char *driver;
  70         char *action;
  71         char *devpath_old;
  72         char *id_filename;
  73         char **envp;
  74         char *monitor_buf;
  75         size_t monitor_buf_len;
  76         struct udev_list devlinks_list;
  77         struct udev_list properties_list;
  78         struct udev_list sysattr_value_list;
  79         struct udev_list sysattr_list;
  80         struct udev_list tags_list;
  81         unsigned long long int seqnum;
  82         usec_t usec_initialized;
  83         int devlink_priority;
  84         int refcount;
  85         dev_t devnum;
  86         int ifindex;
  87         int watch_handle;
  88         int maj, min;
  89         bool parent_set;
  90         bool subsystem_set;
  91         bool devtype_set;
  92         bool devlinks_uptodate;
  93         bool envp_uptodate;
  94         bool tags_uptodate;
  95         bool driver_set;
  96         bool info_loaded;
  97         bool db_loaded;
  98         bool uevent_loaded;
  99         bool is_initialized;
 100         bool sysattr_list_read;
 101         bool db_persist;
 102 };
 103
 104 /**
 105  * udev_device_get_seqnum:
 106  * @udev_device: udev device
 107  *
 108  * This is only valid if the device was received through a monitor. Devices read from
 109  * sys do not have a sequence number.
 110  *
 111  * Returns: the kernel event sequence number, or 0 if there is no sequence number available.
 112  **/
 113 _public_ unsigned long long int udev_device_get_seqnum(struct udev_device *udev_device)
 114 {
 115         if (udev_device == NULL)
 116                 return 0;
 117         return udev_device->seqnum;
 118 }
 119
 120 static int udev_device_set_seqnum(struct udev_device *udev_device, unsigned long long int seqnum)
 121 {
 122         char num[32];
 123
 124         udev_device->seqnum = seqnum;
 125         snprintf(num, sizeof(num), "%llu", seqnum);
 126         udev_device_add_property(udev_device, "SEQNUM", num);
 127         return 0;
 128 }
 129
 130 int udev_device_get_ifindex(struct udev_device *udev_device)
 131 {
 132         if (!udev_device->info_loaded)
 133                 udev_device_read_uevent_file(udev_device);
 134         return udev_device->ifindex;
 135 }
 136
 137 static int udev_device_set_ifindex(struct udev_device *udev_device, int ifindex)
 138 {
 139         char num[32];
 140
 141         udev_device->ifindex = ifindex;
 142         snprintf(num, sizeof(num), "%u", ifindex);
 143         udev_device_add_property(udev_device, "IFINDEX", num);
 144         return 0;
 145 }
 146
 147 /**
 148  * udev_device_get_devnum:
 149  * @udev_device: udev device
 150  *
 151  * Get the device major/minor number.
 152  *
 153  * Returns: the dev_t number.
 154  **/
 155 _public_ dev_t udev_device_get_devnum(struct udev_device *udev_device)
 156 {
 157         if (udev_device == NULL)
 158                 return makedev(0, 0);
 159         if (!udev_device->info_loaded)
 160                 udev_device_read_uevent_file(udev_device);
 161         return udev_device->devnum;
 162 }
 163
 164 int udev_device_set_devnum(struct udev_device *udev_device, dev_t devnum)
 165 {
 166         char num[32];
 167
 168         udev_device->devnum = devnum;
 169
 170         snprintf(num, sizeof(num), "%u", major(devnum));
 171         udev_device_add_property(udev_device, "MAJOR", num);
 172         snprintf(num, sizeof(num), "%u", minor(devnum));
 173         udev_device_add_property(udev_device, "MINOR", num);
 174         return 0;
 175 }
 176
 177 const char *udev_device_get_devpath_old(struct udev_device *udev_device)
 178 {
 179         return udev_device->devpath_old;
 180 }
 181
 182 static int udev_device_set_devpath_old(struct udev_device *udev_device, const char *devpath_old)
 183 {
 184         const char *pos;
 185
 186         free(udev_device->devpath_old);
 187         udev_device->devpath_old = strdup(devpath_old);
 188         if (udev_device->devpath_old == NULL)
 189                 return -ENOMEM;
 190         udev_device_add_property(udev_device, "DEVPATH_OLD", udev_device->devpath_old);
 191
 192         pos = strrchr(udev_device->devpath_old, '/');
 193         if (pos == NULL)
 194                 return -EINVAL;
 195         return 0;
 196 }
 197
 198 /**
 199  * udev_device_get_driver:
 200  * @udev_device: udev device
 201  *
 202  * Get the kernel driver name.
 203  *
 204  * Returns: the driver name string, or #NULL if there is no driver attached.
 205  **/
 206 _public_ const char *udev_device_get_driver(struct udev_device *udev_device)
 207 {
 208         char driver[UTIL_NAME_SIZE];
 209
 210         if (udev_device == NULL)
 211                 return NULL;
 212         if (!udev_device->driver_set) {
 213                 udev_device->driver_set = true;
 214                 if (util_get_sys_core_link_value(udev_device->udev, "driver", udev_device->syspath, driver, sizeof(driver)) > 0)
 215                         udev_device->driver = strdup(driver);
 216         }
 217         return udev_device->driver;
 218 }
 219
 220 static int udev_device_set_driver(struct udev_device *udev_device, const char *driver)
 221 {
 222         free(udev_device->driver);
 223         udev_device->driver = strdup(driver);
 224         if (udev_device->driver == NULL)
 225                 return -ENOMEM;
 226         udev_device->driver_set = true;
 227         udev_device_add_property(udev_device, "DRIVER", udev_device->driver);
 228         return 0;
 229 }
 230
 231 /**
 232  * udev_device_get_devtype:
 233  * @udev_device: udev device
 234  *
 235  * Retrieve the devtype string of the udev device.
 236  *
 237  * Returns: the devtype name of the udev device, or #NULL if it can not be determined
 238  **/
 239 _public_ const char *udev_device_get_devtype(struct udev_device *udev_device)
 240 {
 241         if (udev_device == NULL)
 242                 return NULL;
 243         if (!udev_device->devtype_set) {
 244                 udev_device->devtype_set = true;
 245                 udev_device_read_uevent_file(udev_device);
 246         }
 247         return udev_device->devtype;
 248 }
 249
 250 static int udev_device_set_devtype(struct udev_device *udev_device, const char *devtype)
 251 {
 252         free(udev_device->devtype);
 253         udev_device->devtype = strdup(devtype);
 254         if (udev_device->devtype == NULL)
 255                 return -ENOMEM;
 256         udev_device->devtype_set = true;
 257         udev_device_add_property(udev_device, "DEVTYPE", udev_device->devtype);
 258         return 0;
 259 }
 260
 261 int udev_device_set_subsystem(struct udev_device *udev_device, const char *subsystem)
 262 {
 263         free(udev_device->subsystem);
 264         udev_device->subsystem = strdup(subsystem);
 265         if (udev_device->subsystem == NULL)
 266                 return -ENOMEM;
 267         udev_device->subsystem_set = true;
 268         udev_device_add_property(udev_device, "SUBSYSTEM", udev_device->subsystem);
 269         return 0;
 270 }
 271
 272 /**
 273  * udev_device_get_subsystem:
 274  * @udev_device: udev device
 275  *
 276  * Retrieve the subsystem string of the udev device. The string does not
 277  * contain any "/".
 278  *
 279  * Returns: the subsystem name of the udev device, or #NULL if it can not be determined
 280  **/
 281 _public_ const char *udev_device_get_subsystem(struct udev_device *udev_device)
 282 {
 283         char subsystem[UTIL_NAME_SIZE];
 284
 285         if (udev_device == NULL)
 286                 return NULL;
 287         if (!udev_device->subsystem_set) {
 288                 udev_device->subsystem_set = true;
 289                 /* read "subsystem" link */
 290                 if (util_get_sys_core_link_value(udev_device->udev, "subsystem", udev_device->syspath, subsystem, sizeof(subsystem)) > 0) {
 291                         udev_device_set_subsystem(udev_device, subsystem);
 292                         return udev_device->subsystem;
 293                 }
 294                 /* implicit names */
 295                 if (startswith(udev_device->devpath, "/module/")) {
 296                         udev_device_set_subsystem(udev_device, "module");
 297                         return udev_device->subsystem;
 298                 }
 299                 if (strstr(udev_device->devpath, "/drivers/") != NULL) {
 300                         udev_device_set_subsystem(udev_device, "drivers");
 301                         return udev_device->subsystem;
 302                 }
 303                 if (startswith(udev_device->devpath, "/subsystem/") ||
 304                     startswith(udev_device->devpath, "/class/") ||
 305                     startswith(udev_device->devpath, "/bus/")) {
 306                         udev_device_set_subsystem(udev_device, "subsystem");
 307                         return udev_device->subsystem;
 308                 }
 309         }
 310         return udev_device->subsystem;
 311 }
 312
 313 mode_t udev_device_get_devnode_mode(struct udev_device *udev_device)
 314 {
 315         if (!udev_device->info_loaded)
 316                 udev_device_read_uevent_file(udev_device);
 317         return udev_device->devnode_mode;
 318 }
 319
 320 static int udev_device_set_devnode_mode(struct udev_device *udev_device, mode_t mode)
 321 {
 322         char num[32];
 323
 324         udev_device->devnode_mode = mode;
 325         snprintf(num, sizeof(num), "%#o", mode);
 326         udev_device_add_property(udev_device, "DEVMODE", num);
 327         return 0;
 328 }
 329
 330 uid_t udev_device_get_devnode_uid(struct udev_device *udev_device)
 331 {
 332         if (!udev_device->info_loaded)
 333                 udev_device_read_uevent_file(udev_device);
 334         return udev_device->devnode_uid;
 335 }
 336
 337 static int udev_device_set_devnode_uid(struct udev_device *udev_device, uid_t uid)
 338 {
 339         char num[32];
 340
 341         udev_device->devnode_uid = uid;
 342         snprintf(num, sizeof(num), "%u", uid);
 343         udev_device_add_property(udev_device, "DEVUID", num);
 344         return 0;
 345 }
 346
 347 gid_t udev_device_get_devnode_gid(struct udev_device *udev_device)
 348 {
 349         if (!udev_device->info_loaded)
 350                 udev_device_read_uevent_file(udev_device);
 351         return udev_device->devnode_gid;
 352 }
 353
 354 static int udev_device_set_devnode_gid(struct udev_device *udev_device, gid_t gid)
 355 {
 356         char num[32];
 357
 358         udev_device->devnode_gid = gid;
 359         snprintf(num, sizeof(num), "%u", gid);
 360         udev_device_add_property(udev_device, "DEVGID", num);
 361         return 0;
 362 }
 363
 364 struct udev_list_entry *udev_device_add_property(struct udev_device *udev_device, const char *key, const char *value)
 365 {
 366         udev_device->envp_uptodate = false;
 367         if (value == NULL) {
 368                 struct udev_list_entry *list_entry;
 369
 370                 list_entry = udev_device_get_properties_list_entry(udev_device);
 371                 list_entry = udev_list_entry_get_by_name(list_entry, key);
 372                 if (list_entry != NULL)
 373                         udev_list_entry_delete(list_entry);
 374                 return NULL;
 375         }
 376         return udev_list_entry_add(&udev_device->properties_list, key, value);
 377 }
 378
 379 static struct udev_list_entry *udev_device_add_property_from_string(struct udev_device *udev_device, const char *property)
 380 {
 381         char name[UTIL_LINE_SIZE];
 382         char *val;
 383
 384         strscpy(name, sizeof(name), property);
 385         val = strchr(name, '=');
 386         if (val == NULL)
 387                 return NULL;
 388         val[0] = '\0';
 389         val = &val[1];
 390         if (val[0] == '\0')
 391                 val = NULL;
 392         return udev_device_add_property(udev_device, name, val);
 393 }
 394
 395 /*
 396  * parse property string, and if needed, update internal values accordingly
 397  *
 398  * udev_device_add_property_from_string_parse_finish() needs to be
 399  * called after adding properties, and its return value checked
 400  *
 401  * udev_device_set_info_loaded() needs to be set, to avoid trying
 402  * to use a device without a DEVPATH set
 403  */
 404 void udev_device_add_property_from_string_parse(struct udev_device *udev_device, const char *property)
 405 {
 406         if (startswith(property, "DEVPATH=")) {
 407                 char path[UTIL_PATH_SIZE];
 408
 409                 strscpyl(path, sizeof(path), "/sys", &property[8], NULL);
 410                 udev_device_set_syspath(udev_device, path);
 411         } else if (startswith(property, "SUBSYSTEM=")) {
 412                 udev_device_set_subsystem(udev_device, &property[10]);
 413         } else if (startswith(property, "DEVTYPE=")) {
 414                 udev_device_set_devtype(udev_device, &property[8]);
 415         } else if (startswith(property, "DEVNAME=")) {
 416                 udev_device_set_devnode(udev_device, &property[8]);
 417         } else if (startswith(property, "DEVLINKS=")) {
 418                 char devlinks[UTIL_PATH_SIZE];
 419                 char *slink;
 420                 char *next;
 421
 422                 strscpy(devlinks, sizeof(devlinks), &property[9]);
 423                 slink = devlinks;
 424                 next = strchr(slink, ' ');
 425                 while (next != NULL) {
 426                         next[0] = '\0';
 427                         udev_device_add_devlink(udev_device, slink);
 428                         slink = &next[1];
 429                         next = strchr(slink, ' ');
 430                 }
 431                 if (slink[0] != '\0')
 432                         udev_device_add_devlink(udev_device, slink);
 433         } else if (startswith(property, "TAGS=")) {
 434                 char tags[UTIL_PATH_SIZE];
 435                 char *next;
 436
 437                 strscpy(tags, sizeof(tags), &property[5]);
 438                 next = strchr(tags, ':');
 439                 if (next != NULL) {
 440                         next++;
 441                         while (next[0] != '\0') {
 442                                 char *tag;
 443
 444                                 tag = next;
 445                                 next = strchr(tag, ':');
 446                                 if (next == NULL)
 447                                         break;
 448                                 next[0] = '\0';
 449                                 next++;
 450                                 udev_device_add_tag(udev_device, tag);
 451                         }
 452                 }
 453         } else if (startswith(property, "USEC_INITIALIZED=")) {
 454                 udev_device_set_usec_initialized(udev_device, strtoull(&property[19], NULL, 10));
 455         } else if (startswith(property, "DRIVER=")) {
 456                 udev_device_set_driver(udev_device, &property[7]);
 457         } else if (startswith(property, "ACTION=")) {
 458                 udev_device_set_action(udev_device, &property[7]);
 459         } else if (startswith(property, "MAJOR=")) {
 460                 udev_device->maj = strtoull(&property[6], NULL, 10);
 461         } else if (startswith(property, "MINOR=")) {
 462                 udev_device->min = strtoull(&property[6], NULL, 10);
 463         } else if (startswith(property, "DEVPATH_OLD=")) {
 464                 udev_device_set_devpath_old(udev_device, &property[12]);
 465         } else if (startswith(property, "SEQNUM=")) {
 466                 udev_device_set_seqnum(udev_device, strtoull(&property[7], NULL, 10));
 467         } else if (startswith(property, "IFINDEX=")) {
 468                 udev_device_set_ifindex(udev_device, strtoull(&property[8], NULL, 10));
 469         } else if (startswith(property, "DEVMODE=")) {
 470                 udev_device_set_devnode_mode(udev_device, strtoul(&property[8], NULL, 8));
 471         } else if (startswith(property, "DEVUID=")) {
 472                 udev_device_set_devnode_uid(udev_device, strtoul(&property[7], NULL, 10));
 473         } else if (startswith(property, "DEVGID=")) {
 474                 udev_device_set_devnode_gid(udev_device, strtoul(&property[7], NULL, 10));
 475         } else {
 476                 udev_device_add_property_from_string(udev_device, property);
 477         }
 478 }
 479
 480 int udev_device_add_property_from_string_parse_finish(struct udev_device *udev_device)
 481 {
 482         if (udev_device->maj > 0)
 483                 udev_device_set_devnum(udev_device, makedev(udev_device->maj, udev_device->min));
 484         udev_device->maj = 0;
 485         udev_device->min = 0;
 486
 487         if (udev_device->devpath == NULL || udev_device->subsystem == NULL)
 488                 return -EINVAL;
 489         return 0;
 490 }
 491
 492 /**
 493  * udev_device_get_property_value:
 494  * @udev_device: udev device
 495  * @key: property name
 496  *
 497  * Get the value of a given property.
 498  *
 499  * Returns: the property string, or #NULL if there is no such property.
 500  **/
 501 _public_ const char *udev_device_get_property_value(struct udev_device *udev_device, const char *key)
 502 {
 503         struct udev_list_entry *list_entry;
 504
 505         if (udev_device == NULL)
 506                 return NULL;
 507         if (key == NULL)
 508                 return NULL;
 509
 510         list_entry = udev_device_get_properties_list_entry(udev_device);
 511         list_entry = udev_list_entry_get_by_name(list_entry, key);
 512         return udev_list_entry_get_value(list_entry);
 513 }
 514
 515 int udev_device_read_db(struct udev_device *udev_device, const char *dbfile)
 516 {
 517         char filename[UTIL_PATH_SIZE];
 518         char line[UTIL_LINE_SIZE];
 519         FILE *f;
 520
 521         /* providing a database file will always force-load it */
 522         if (dbfile == NULL) {
 523                 const char *id;
 524
 525                 if (udev_device->db_loaded)
 526                         return 0;
 527                 udev_device->db_loaded = true;
 528
 529                 id = udev_device_get_id_filename(udev_device);
 530                 if (id == NULL)
 531                         return -1;
 532                 strscpyl(filename, sizeof(filename), "/run/udev/data/", id, NULL);
 533                 dbfile = filename;
 534         }
 535
 536         f = fopen(dbfile, "re");
 537         if (f == NULL) {
 538                 log_debug("no db file to read %s: %m\n", dbfile);
 539                 return -errno;
 540         }
 541
 542         /* devices with a database entry are initialized */
 543         udev_device->is_initialized = true;
 544
 545         while (fgets(line, sizeof(line), f)) {
 546                 ssize_t len;
 547                 const char *val;
 548                 struct udev_list_entry *entry;
 549
 550                 len = strlen(line);
 551                 if (len < 4)
 552                         break;
 553                 line[len-1] = '\0';
 554                 val = &line[2];
 555                 switch(line[0]) {
 556                 case 'S':
 557                         strscpyl(filename, sizeof(filename), "/dev/", val, NULL);
 558                         udev_device_add_devlink(udev_device, filename);
 559                         break;
 560                 case 'L':
 561                         udev_device_set_devlink_priority(udev_device, atoi(val));
 562                         break;
 563                 case 'E':
 564                         entry = udev_device_add_property_from_string(udev_device, val);
 565                         udev_list_entry_set_num(entry, true);
 566                         break;
 567                 case 'G':
 568                         udev_device_add_tag(udev_device, val);
 569                         break;
 570                 case 'W':
 571                         udev_device_set_watch_handle(udev_device, atoi(val));
 572                         break;
 573                 case 'I':
 574                         udev_device_set_usec_initialized(udev_device, strtoull(val, NULL, 10));
 575                         break;
 576                 }
 577         }
 578         fclose(f);
 579
 580         log_debug("device %p filled with db file data\n", udev_device);
 581         return 0;
 582 }
 583
 584 int udev_device_read_uevent_file(struct udev_device *udev_device)
 585 {
 586         char filename[UTIL_PATH_SIZE];
 587         FILE *f;
 588         char line[UTIL_LINE_SIZE];
 589         int maj = 0;
 590         int min = 0;
 591
 592         if (udev_device->uevent_loaded)
 593                 return 0;
 594
 595         strscpyl(filename, sizeof(filename), udev_device->syspath, "/uevent", NULL);
 596         f = fopen(filename, "re");
 597         if (f == NULL)
 598                 return -errno;
 599         udev_device->uevent_loaded = true;
 600
 601         while (fgets(line, sizeof(line), f)) {
 602                 char *pos;
 603
 604                 pos = strchr(line, '\n');
 605                 if (pos == NULL)
 606                         continue;
 607                 pos[0] = '\0';
 608
 609                 if (startswith(line, "DEVTYPE=")) {
 610                         udev_device_set_devtype(udev_device, &line[8]);
 611                         continue;
 612                 }
 613                 if (startswith(line, "IFINDEX=")) {
 614                         udev_device_set_ifindex(udev_device, strtoull(&line[8], NULL, 10));
 615                         continue;
 616                 }
 617                 if (startswith(line, "DEVNAME=")) {
 618                         udev_device_set_devnode(udev_device, &line[8]);
 619                         continue;
 620                 }
 621
 622                 if (startswith(line, "MAJOR="))
 623                         maj = strtoull(&line[6], NULL, 10);
 624                 else if (startswith(line, "MINOR="))
 625                         min = strtoull(&line[6], NULL, 10);
 626                 else if (startswith(line, "DEVMODE="))
 627                         udev_device->devnode_mode = strtoul(&line[8], NULL, 8);
 628
 629                 udev_device_add_property_from_string(udev_device, line);
 630         }
 631
 632         udev_device->devnum = makedev(maj, min);
 633         fclose(f);
 634         return 0;
 635 }
 636
 637 void udev_device_set_info_loaded(struct udev_device *device)
 638 {
 639         device->info_loaded = true;
 640 }
 641
 642 struct udev_device *udev_device_new(struct udev *udev)
 643 {
 644         struct udev_device *udev_device;
 645
 646         if (udev == NULL) {
 647                 errno = EINVAL;
 648                 return NULL;
 649         }
 650
 651         udev_device = new0(struct udev_device, 1);
 652         if (udev_device == NULL) {
 653                 errno = ENOMEM;
 654                 return NULL;
 655         }
 656         udev_device->refcount = 1;
 657         udev_device->udev = udev;
 658         udev_list_init(udev, &udev_device->devlinks_list, true);
 659         udev_list_init(udev, &udev_device->properties_list, true);
 660         udev_list_init(udev, &udev_device->sysattr_value_list, true);
 661         udev_list_init(udev, &udev_device->sysattr_list, false);
 662         udev_list_init(udev, &udev_device->tags_list, true);
 663         udev_device->watch_handle = -1;
 664
 665         return udev_device;
 666 }
 667
 668 /**
 669  * udev_device_new_from_syspath:
 670  * @udev: udev library context
 671  * @syspath: sys device path including sys directory
 672  *
 673  * Create new udev device, and fill in information from the sys
 674  * device and the udev database entry. The syspath is the absolute
 675  * path to the device, including the sys mount point.
 676  *
 677  * The initial refcount is 1, and needs to be decremented to
 678  * release the resources of the udev device.
 679  *
 680  * Returns: a new udev device, or #NULL, if it does not exist
 681  **/
 682 _public_ struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *syspath)
 683 {
 684         const char *subdir;
 685         char path[UTIL_PATH_SIZE];
 686         char *pos;
 687         struct stat statbuf;
 688         struct udev_device *udev_device;
 689
 690         if (udev == NULL) {
 691                 errno = EINVAL;
 692                 return NULL;
 693         }
 694
 695         if (syspath == NULL) {
 696                 errno = EINVAL;
 697                 return NULL;
 698         }
 699
 700         /* path starts in sys */
 701         if (!startswith(syspath, "/sys")) {
 702                 log_debug("not in sys :%s\n", syspath);
 703                 errno = EINVAL;
 704                 return NULL;
 705         }
 706
 707         /* path is not a root directory */
 708         subdir = syspath + strlen("/sys");
 709         pos = strrchr(subdir, '/');
 710         if (pos == NULL || pos[1] == '\0' || pos < &subdir[2]) {
 711                 errno = EINVAL;
 712                 return NULL;
 713         }
 714
 715         /* resolve possible symlink to real path */
 716         strscpy(path, sizeof(path), syspath);
 717         util_resolve_sys_link(udev, path, sizeof(path));
 718
 719         if (startswith(path + strlen("/sys"), "/devices/")) {
 720                 char file[UTIL_PATH_SIZE];
 721
 722                 /* all "devices" require a "uevent" file */
 723                 strscpyl(file, sizeof(file), path, "/uevent", NULL);
 724                 if (stat(file, &statbuf) != 0)
 725                         return NULL;
 726         } else {
 727                 /* everything else just needs to be a directory */
 728                 if (stat(path, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode))
 729                         return NULL;
 730         }
 731
 732         udev_device = udev_device_new(udev);
 733         if (udev_device == NULL)
 734                 return NULL;
 735
 736         udev_device_set_syspath(udev_device, path);
 737         log_debug("device %p has devpath '%s'\n", udev_device, udev_device_get_devpath(udev_device));
 738
 739         return udev_device;
 740 }
 741
 742 /**
 743  * udev_device_new_from_devnum:
 744  * @udev: udev library context
 745  * @type: char or block device
 746  * @devnum: device major/minor number
 747  *
 748  * Create new udev device, and fill in information from the sys
 749  * device and the udev database entry. The device is looked-up
 750  * by its major/minor number and type. Character and block device
 751  * numbers are not unique across the two types.
 752  *
 753  * The initial refcount is 1, and needs to be decremented to
 754  * release the resources of the udev device.
 755  *
 756  * Returns: a new udev device, or #NULL, if it does not exist
 757  **/
 758 _public_ struct udev_device *udev_device_new_from_devnum(struct udev *udev, char type, dev_t devnum)
 759 {
 760         char path[UTIL_PATH_SIZE];
 761         const char *type_str;
 762
 763         if (type == 'b')
 764                 type_str = "block";
 765         else if (type == 'c')
 766                 type_str = "char";
 767         else {
 768                 errno = EINVAL;
 769                 return NULL;
 770         }
 771
 772         /* use /sys/dev/{block,char}/<maj>:<min> link */
 773         snprintf(path, sizeof(path), "/sys/dev/%s/%u:%u",
 774                  type_str, major(devnum), minor(devnum));
 775         return udev_device_new_from_syspath(udev, path);
 776 }
 777
 778 /**
 779  * udev_device_new_from_device_id:
 780  * @udev: udev library context
 781  * @id: text string identifying a kernel device
 782  *
 783  * Create new udev device, and fill in information from the sys
 784  * device and the udev database entry. The device is looked-up
 785  * by a special string:
 786  *   b8:2          - block device major:minor
 787  *   c128:1        - char device major:minor
 788  *   n3            - network device ifindex
 789  *   +sound:card29 - kernel driver core subsystem:device name
 790  *
 791  * The initial refcount is 1, and needs to be decremented to
 792  * release the resources of the udev device.
 793  *
 794  * Returns: a new udev device, or #NULL, if it does not exist
 795  **/
 796 _public_ struct udev_device *udev_device_new_from_device_id(struct udev *udev, const char *id)
 797 {
 798         char type;
 799         int maj, min;
 800         char subsys[UTIL_PATH_SIZE];
 801         char *sysname;
 802
 803         switch(id[0]) {
 804         case 'b':
 805         case 'c':
 806                 if (sscanf(id, "%c%i:%i", &type, &maj, &min) != 3)
 807                         return NULL;
 808                 return udev_device_new_from_devnum(udev, type, makedev(maj, min));
 809         case 'n': {
 810                 int sk;
 811                 struct ifreq ifr;
 812                 struct udev_device *dev;
 813                 int ifindex;
 814
 815                 ifindex = strtoul(&id[1], NULL, 10);
 816                 if (ifindex <= 0) {
 817                         errno = EINVAL;
 818                         return NULL;
 819                 }
 820
 821                 sk = socket(PF_INET, SOCK_DGRAM, 0);
 822                 if (sk < 0)
 823                         return NULL;
 824                 memzero(&ifr, sizeof(struct ifreq));
 825                 ifr.ifr_ifindex = ifindex;
 826                 if (ioctl(sk, SIOCGIFNAME, &ifr) != 0) {
 827                         close(sk);
 828                         return NULL;
 829                 }
 830                 close(sk);
 831
 832                 dev = udev_device_new_from_subsystem_sysname(udev, "net", ifr.ifr_name);
 833                 if (dev == NULL)
 834                         return NULL;
 835                 if (udev_device_get_ifindex(dev) == ifindex)
 836                         return dev;
 837
 838                 /* this is racy, so we may end up with the wrong device */
 839                 udev_device_unref(dev);
 840                 errno = ENODEV;
 841                 return NULL;
 842         }
 843         case '+':
 844                 strscpy(subsys, sizeof(subsys), &id[1]);
 845                 sysname = strchr(subsys, ':');
 846                 if (sysname == NULL) {
 847                         errno = EINVAL;
 848                         return NULL;
 849                 }
 850                 sysname[0] = '\0';
 851                 sysname = &sysname[1];
 852                 return udev_device_new_from_subsystem_sysname(udev, subsys, sysname);
 853         default:
 854                 errno = EINVAL;
 855                 return NULL;
 856         }
 857 }
 858
 859 /**
 860  * udev_device_new_from_subsystem_sysname:
 861  * @udev: udev library context
 862  * @subsystem: the subsystem of the device
 863  * @sysname: the name of the device
 864  *
 865  * Create new udev device, and fill in information from the sys device
 866  * and the udev database entry. The device is looked up by the subsystem
 867  * and name string of the device, like "mem" / "zero", or "block" / "sda".
 868  *
 869  * The initial refcount is 1, and needs to be decremented to
 870  * release the resources of the udev device.
 871  *
 872  * Returns: a new udev device, or #NULL, if it does not exist
 873  **/
 874 _public_ struct udev_device *udev_device_new_from_subsystem_sysname(struct udev *udev, const char *subsystem, const char *sysname)
 875 {
 876         char path[UTIL_PATH_SIZE];
 877         struct stat statbuf;
 878
 879         if (streq(subsystem, "subsystem")) {
 880                 strscpyl(path, sizeof(path), "/sys/subsystem/", sysname, NULL);
 881                 if (stat(path, &statbuf) == 0)
 882                         goto found;
 883
 884                 strscpyl(path, sizeof(path), "/sys/bus/", sysname, NULL);
 885                 if (stat(path, &statbuf) == 0)
 886                         goto found;
 887
 888                 strscpyl(path, sizeof(path), "/sys/class/", sysname, NULL);
 889                 if (stat(path, &statbuf) == 0)
 890                         goto found;
 891                 goto out;
 892         }
 893
 894         if (streq(subsystem, "module")) {
 895                 strscpyl(path, sizeof(path), "/sys/module/", sysname, NULL);
 896                 if (stat(path, &statbuf) == 0)
 897                         goto found;
 898                 goto out;
 899         }
 900
 901         if (streq(subsystem, "drivers")) {
 902                 char subsys[UTIL_NAME_SIZE];
 903                 char *driver;
 904
 905                 strscpy(subsys, sizeof(subsys), sysname);
 906                 driver = strchr(subsys, ':');
 907                 if (driver != NULL) {
 908                         driver[0] = '\0';
 909                         driver = &driver[1];
 910
 911                         strscpyl(path, sizeof(path), "/sys/subsystem/", subsys, "/drivers/", driver, NULL);
 912                         if (stat(path, &statbuf) == 0)
 913                                 goto found;
 914
 915                         strscpyl(path, sizeof(path), "/sys/bus/", subsys, "/drivers/", driver, NULL);
 916                         if (stat(path, &statbuf) == 0)
 917                                 goto found;
 918                 } else
 919                         errno = EINVAL;
 920
 921                 goto out;
 922         }
 923
 924         strscpyl(path, sizeof(path), "/sys/subsystem/", subsystem, "/devices/", sysname, NULL);
 925         if (stat(path, &statbuf) == 0)
 926                 goto found;
 927
 928         strscpyl(path, sizeof(path), "/sys/bus/", subsystem, "/devices/", sysname, NULL);
 929         if (stat(path, &statbuf) == 0)
 930                 goto found;
 931
 932         strscpyl(path, sizeof(path), "/sys/class/", subsystem, "/", sysname, NULL);
 933         if (stat(path, &statbuf) == 0)
 934                 goto found;
 935 out:
 936         return NULL;
 937 found:
 938         return udev_device_new_from_syspath(udev, path);
 939 }
 940
 941 /**
 942  * udev_device_new_from_environment
 943  * @udev: udev library context
 944  *
 945  * Create new udev device, and fill in information from the
 946  * current process environment. This only works reliable if
 947  * the process is called from a udev rule. It is usually used
 948  * for tools executed from IMPORT= rules.
 949  *
 950  * The initial refcount is 1, and needs to be decremented to
 951  * release the resources of the udev device.
 952  *
 953  * Returns: a new udev device, or #NULL, if it does not exist
 954  **/
 955 _public_ struct udev_device *udev_device_new_from_environment(struct udev *udev)
 956 {
 957         int i;
 958         struct udev_device *udev_device;
 959
 960         udev_device = udev_device_new(udev);
 961         if (udev_device == NULL)
 962                 return NULL;
 963         udev_device_set_info_loaded(udev_device);
 964
 965         for (i = 0; environ[i] != NULL; i++)
 966                 udev_device_add_property_from_string_parse(udev_device, environ[i]);
 967
 968         if (udev_device_add_property_from_string_parse_finish(udev_device) < 0) {
 969                 log_debug("missing values, invalid device\n");
 970                 udev_device_unref(udev_device);
 971                 udev_device = NULL;
 972         }
 973
 974         return udev_device;
 975 }
 976
 977 static struct udev_device *device_new_from_parent(struct udev_device *udev_device)
 978 {
 979         struct udev_device *udev_device_parent = NULL;
 980         char path[UTIL_PATH_SIZE];
 981         const char *subdir;
 982
 983         strscpy(path, sizeof(path), udev_device->syspath);
 984         subdir = path + strlen("/sys/");
 985         for (;;) {
 986                 char *pos;
 987
 988                 pos = strrchr(subdir, '/');
 989                 if (pos == NULL || pos < &subdir[2])
 990                         break;
 991                 pos[0] = '\0';
 992                 udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
 993                 if (udev_device_parent != NULL)
 994                         return udev_device_parent;
 995         }
 996
 997         errno = ENOENT;
 998         return NULL;
 999 }
1000
1001 /**
1002  * udev_device_get_parent:
1003  * @udev_device: the device to start searching from
1004  *
1005  * Find the next parent device, and fill in information from the sys
1006  * device and the udev database entry.
1007  *
1008  * Returned device is not referenced. It is attached to the child
1009  * device, and will be cleaned up when the child device is cleaned up.
1010  *
1011  * It is not necessarily just the upper level directory, empty or not
1012  * recognized sys directories are ignored.
1013  *
1014  * It can be called as many times as needed, without caring about
1015  * references.
1016  *
1017  * Returns: a new udev device, or #NULL, if it no parent exist.
1018  **/
1019 _public_ struct udev_device *udev_device_get_parent(struct udev_device *udev_device)
1020 {
1021         if (udev_device == NULL) {
1022                 errno = EINVAL;
1023                 return NULL;
1024         }
1025         if (!udev_device->parent_set) {
1026                 udev_device->parent_set = true;
1027                 udev_device->parent_device = device_new_from_parent(udev_device);
1028         }
1029         return udev_device->parent_device;
1030 }
1031
1032 /**
1033  * udev_device_get_parent_with_subsystem_devtype:
1034  * @udev_device: udev device to start searching from
1035  * @subsystem: the subsystem of the device
1036  * @devtype: the type (DEVTYPE) of the device
1037  *
1038  * Find the next parent device, with a matching subsystem and devtype
1039  * value, and fill in information from the sys device and the udev
1040  * database entry.
1041  *
1042  * If devtype is #NULL, only subsystem is checked, and any devtype will
1043  * match.
1044  *
1045  * Returned device is not referenced. It is attached to the child
1046  * device, and will be cleaned up when the child device is cleaned up.
1047  *
1048  * It can be called as many times as needed, without caring about
1049  * references.
1050  *
1051  * Returns: a new udev device, or #NULL if no matching parent exists.
1052  **/
1053 _public_ struct udev_device *udev_device_get_parent_with_subsystem_devtype(struct udev_device *udev_device, const char *subsystem, const char *devtype)
1054 {
1055         struct udev_device *parent;
1056
1057         if (subsystem == NULL) {
1058                 errno = EINVAL;
1059                 return NULL;
1060         }
1061
1062         parent = udev_device_get_parent(udev_device);
1063         while (parent != NULL) {
1064                 const char *parent_subsystem;
1065                 const char *parent_devtype;
1066
1067                 parent_subsystem = udev_device_get_subsystem(parent);
1068                 if (parent_subsystem != NULL && streq(parent_subsystem, subsystem)) {
1069                         if (devtype == NULL)
1070                                 break;
1071                         parent_devtype = udev_device_get_devtype(parent);
1072                         if (parent_devtype != NULL && streq(parent_devtype, devtype))
1073                                 break;
1074                 }
1075                 parent = udev_device_get_parent(parent);
1076         }
1077
1078         if (!parent)
1079                 errno = ENOENT;
1080
1081         return parent;
1082 }
1083
1084 /**
1085  * udev_device_get_udev:
1086  * @udev_device: udev device
1087  *
1088  * Retrieve the udev library context the device was created with.
1089  *
1090  * Returns: the udev library context
1091  **/
1092 _public_ struct udev *udev_device_get_udev(struct udev_device *udev_device)
1093 {
1094         if (udev_device == NULL)
1095                 return NULL;
1096         return udev_device->udev;
1097 }
1098
1099 /**
1100  * udev_device_ref:
1101  * @udev_device: udev device
1102  *
1103  * Take a reference of a udev device.
1104  *
1105  * Returns: the passed udev device
1106  **/
1107 _public_ struct udev_device *udev_device_ref(struct udev_device *udev_device)
1108 {
1109         if (udev_device == NULL)
1110                 return NULL;
1111         udev_device->refcount++;
1112         return udev_device;
1113 }
1114
1115 /**
1116  * udev_device_unref:
1117  * @udev_device: udev device
1118  *
1119  * Drop a reference of a udev device. If the refcount reaches zero,
1120  * the resources of the device will be released.
1121  *
1122  * Returns: #NULL
1123  **/
1124 _public_ struct udev_device *udev_device_unref(struct udev_device *udev_device)
1125 {
1126         if (udev_device == NULL)
1127                 return NULL;
1128         udev_device->refcount--;
1129         if (udev_device->refcount > 0)
1130                 return NULL;
1131         if (udev_device->parent_device != NULL)
1132                 udev_device_unref(udev_device->parent_device);
1133         free(udev_device->syspath);
1134         free(udev_device->sysname);
1135         free(udev_device->devnode);
1136         free(udev_device->subsystem);
1137         free(udev_device->devtype);
1138         udev_list_cleanup(&udev_device->devlinks_list);
1139         udev_list_cleanup(&udev_device->properties_list);
1140         udev_list_cleanup(&udev_device->sysattr_value_list);
1141         udev_list_cleanup(&udev_device->sysattr_list);
1142         udev_list_cleanup(&udev_device->tags_list);
1143         free(udev_device->action);
1144         free(udev_device->driver);
1145         free(udev_device->devpath_old);
1146         free(udev_device->id_filename);
1147         free(udev_device->envp);
1148         free(udev_device->monitor_buf);
1149         free(udev_device);
1150         return NULL;
1151 }
1152
1153 /**
1154  * udev_device_get_devpath:
1155  * @udev_device: udev device
1156  *
1157  * Retrieve the kernel devpath value of the udev device. The path
1158  * does not contain the sys mount point, and starts with a '/'.
1159  *
1160  * Returns: the devpath of the udev device
1161  **/
1162 _public_ const char *udev_device_get_devpath(struct udev_device *udev_device)
1163 {
1164         if (udev_device == NULL)
1165                 return NULL;
1166         return udev_device->devpath;
1167 }
1168
1169 /**
1170  * udev_device_get_syspath:
1171  * @udev_device: udev device
1172  *
1173  * Retrieve the sys path of the udev device. The path is an
1174  * absolute path and starts with the sys mount point.
1175  *
1176  * Returns: the sys path of the udev device
1177  **/
1178 _public_ const char *udev_device_get_syspath(struct udev_device *udev_device)
1179 {
1180         if (udev_device == NULL)
1181                 return NULL;
1182         return udev_device->syspath;
1183 }
1184
1185 /**
1186  * udev_device_get_sysname:
1187  * @udev_device: udev device
1188  *
1189  * Get the kernel device name in /sys.
1190  *
1191  * Returns: the name string of the device device
1192  **/
1193 _public_ const char *udev_device_get_sysname(struct udev_device *udev_device)
1194 {
1195         if (udev_device == NULL)
1196                 return NULL;
1197         return udev_device->sysname;
1198 }
1199
1200 /**
1201  * udev_device_get_sysnum:
1202  * @udev_device: udev device
1203  *
1204  * Get the instance number of the device.
1205  *
1206  * Returns: the trailing number string of the device name
1207  **/
1208 _public_ const char *udev_device_get_sysnum(struct udev_device *udev_device)
1209 {
1210         if (udev_device == NULL)
1211                 return NULL;
1212         return udev_device->sysnum;
1213 }
1214
1215 /**
1216  * udev_device_get_devnode:
1217  * @udev_device: udev device
1218  *
1219  * Retrieve the device node file name belonging to the udev device.
1220  * The path is an absolute path, and starts with the device directory.
1221  *
1222  * Returns: the device node file name of the udev device, or #NULL if no device node exists
1223  **/
1224 _public_ const char *udev_device_get_devnode(struct udev_device *udev_device)
1225 {
1226         if (udev_device == NULL)
1227                 return NULL;
1228         if (udev_device->devnode != NULL)
1229                 return udev_device->devnode;
1230         if (!udev_device->info_loaded)
1231                 udev_device_read_uevent_file(udev_device);
1232         return udev_device->devnode;
1233 }
1234
1235 /**
1236  * udev_device_get_devlinks_list_entry:
1237  * @udev_device: udev device
1238  *
1239  * Retrieve the list of device links pointing to the device file of
1240  * the udev device. The next list entry can be retrieved with
1241  * udev_list_entry_get_next(), which returns #NULL if no more entries exist.
1242  * The devlink path can be retrieved from the list entry by
1243  * udev_list_entry_get_name(). The path is an absolute path, and starts with
1244  * the device directory.
1245  *
1246  * Returns: the first entry of the device node link list
1247  **/
1248 _public_ struct udev_list_entry *udev_device_get_devlinks_list_entry(struct udev_device *udev_device)
1249 {
1250         if (udev_device == NULL)
1251                 return NULL;
1252         if (!udev_device->info_loaded)
1253                 udev_device_read_db(udev_device, NULL);
1254         return udev_list_get_entry(&udev_device->devlinks_list);
1255 }
1256
1257 void udev_device_cleanup_devlinks_list(struct udev_device *udev_device)
1258 {
1259         udev_device->devlinks_uptodate = false;
1260         udev_list_cleanup(&udev_device->devlinks_list);
1261 }
1262
1263 /**
1264  * udev_device_get_properties_list_entry:
1265  * @udev_device: udev device
1266  *
1267  * Retrieve the list of key/value device properties of the udev
1268  * device. The next list entry can be retrieved with udev_list_entry_get_next(),
1269  * which returns #NULL if no more entries exist. The property name
1270  * can be retrieved from the list entry by udev_list_entry_get_name(),
1271  * the property value by udev_list_entry_get_value().
1272  *
1273  * Returns: the first entry of the property list
1274  **/
1275 _public_ struct udev_list_entry *udev_device_get_properties_list_entry(struct udev_device *udev_device)
1276 {
1277         if (udev_device == NULL)
1278                 return NULL;
1279         if (!udev_device->info_loaded) {
1280                 udev_device_read_uevent_file(udev_device);
1281                 udev_device_read_db(udev_device, NULL);
1282         }
1283         if (!udev_device->devlinks_uptodate) {
1284                 char symlinks[UTIL_PATH_SIZE];
1285                 struct udev_list_entry *list_entry;
1286
1287                 udev_device->devlinks_uptodate = true;
1288                 list_entry = udev_device_get_devlinks_list_entry(udev_device);
1289                 if (list_entry != NULL) {
1290                         char *s;
1291                         size_t l;
1292
1293                         s = symlinks;
1294                         l = strpcpyl(&s, sizeof(symlinks), udev_list_entry_get_name(list_entry), NULL);
1295                         udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry))
1296                                 l = strpcpyl(&s, l, " ", udev_list_entry_get_name(list_entry), NULL);
1297                         udev_device_add_property(udev_device, "DEVLINKS", symlinks);
1298                 }
1299         }
1300         if (!udev_device->tags_uptodate) {
1301                 udev_device->tags_uptodate = true;
1302                 if (udev_device_get_tags_list_entry(udev_device) != NULL) {
1303                         char tags[UTIL_PATH_SIZE];
1304                         struct udev_list_entry *list_entry;
1305                         char *s;
1306                         size_t l;
1307
1308                         s = tags;
1309                         l = strpcpyl(&s, sizeof(tags), ":", NULL);
1310                         udev_list_entry_foreach(list_entry, udev_device_get_tags_list_entry(udev_device))
1311                                 l = strpcpyl(&s, l, udev_list_entry_get_name(list_entry), ":", NULL);
1312                         udev_device_add_property(udev_device, "TAGS", tags);
1313                 }
1314         }
1315         return udev_list_get_entry(&udev_device->properties_list);
1316 }
1317
1318 /**
1319  * udev_device_get_action:
1320  * @udev_device: udev device
1321  *
1322  * This is only valid if the device was received through a monitor. Devices read from
1323  * sys do not have an action string. Usual actions are: add, remove, change, online,
1324  * offline.
1325  *
1326  * Returns: the kernel action value, or #NULL if there is no action value available.
1327  **/
1328 _public_ const char *udev_device_get_action(struct udev_device *udev_device)
1329 {
1330         if (udev_device == NULL)
1331                 return NULL;
1332         return udev_device->action;
1333 }
1334
1335 /**
1336  * udev_device_get_usec_since_initialized:
1337  * @udev_device: udev device
1338  *
1339  * Return the number of microseconds passed since udev set up the
1340  * device for the first time.
1341  *
1342  * This is only implemented for devices with need to store properties
1343  * in the udev database. All other devices return 0 here.
1344  *
1345  * Returns: the number of microseconds since the device was first seen.
1346  **/
1347 _public_ unsigned long long int udev_device_get_usec_since_initialized(struct udev_device *udev_device)
1348 {
1349         usec_t now_ts;
1350
1351         if (udev_device == NULL)
1352                 return 0;
1353         if (!udev_device->info_loaded)
1354                 udev_device_read_db(udev_device, NULL);
1355         if (udev_device->usec_initialized == 0)
1356                 return 0;
1357         now_ts = now(CLOCK_MONOTONIC);
1358         if (now_ts == 0)
1359                 return 0;
1360         return now_ts - udev_device->usec_initialized;
1361 }
1362
1363 usec_t udev_device_get_usec_initialized(struct udev_device *udev_device)
1364 {
1365         return udev_device->usec_initialized;
1366 }
1367
1368 void udev_device_set_usec_initialized(struct udev_device *udev_device, usec_t usec_initialized)
1369 {
1370         char num[32];
1371
1372         udev_device->usec_initialized = usec_initialized;
1373         snprintf(num, sizeof(num), USEC_FMT, usec_initialized);
1374         udev_device_add_property(udev_device, "USEC_INITIALIZED", num);
1375 }
1376
1377 /**
1378  * udev_device_get_sysattr_value:
1379  * @udev_device: udev device
1380  * @sysattr: attribute name
1381  *
1382  * The retrieved value is cached in the device. Repeated calls will return the same
1383  * value and not open the attribute again.
1384  *
1385  * Returns: the content of a sys attribute file, or #NULL if there is no sys attribute value.
1386  **/
1387 _public_ const char *udev_device_get_sysattr_value(struct udev_device *udev_device, const char *sysattr)
1388 {
1389         struct udev_list_entry *list_entry;
1390         char path[UTIL_PATH_SIZE];
1391         char value[4096];
1392         struct stat statbuf;
1393         int fd;
1394         ssize_t size;
1395         const char *val = NULL;
1396
1397         if (udev_device == NULL)
1398                 return NULL;
1399         if (sysattr == NULL)
1400                 return NULL;
1401
1402         /* look for possibly already cached result */
1403         list_entry = udev_list_get_entry(&udev_device->sysattr_value_list);
1404         list_entry = udev_list_entry_get_by_name(list_entry, sysattr);
1405         if (list_entry != NULL)
1406                 return udev_list_entry_get_value(list_entry);
1407
1408         strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", sysattr, NULL);
1409         if (lstat(path, &statbuf) != 0) {
1410                 udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, NULL);
1411                 goto out;
1412         }
1413
1414         if (S_ISLNK(statbuf.st_mode)) {
1415                 /*
1416                  * Some core links return only the last element of the target path,
1417                  * these are just values, the paths should not be exposed.
1418                  */
1419                 if (streq(sysattr, "driver") ||
1420                     streq(sysattr, "subsystem") ||
1421                     streq(sysattr, "module")) {
1422                         if (util_get_sys_core_link_value(udev_device->udev, sysattr,
1423                                                          udev_device->syspath, value, sizeof(value)) < 0)
1424                                 return NULL;
1425                         list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, value);
1426                         val = udev_list_entry_get_value(list_entry);
1427                         goto out;
1428                 }
1429
1430                 goto out;
1431         }
1432
1433         /* skip directories */
1434         if (S_ISDIR(statbuf.st_mode))
1435                 goto out;
1436
1437         /* skip non-readable files */
1438         if ((statbuf.st_mode & S_IRUSR) == 0)
1439                 goto out;
1440
1441         /* read attribute value */
1442         fd = open(path, O_RDONLY|O_CLOEXEC);
1443         if (fd < 0)
1444                 goto out;
1445         size = read(fd, value, sizeof(value));
1446         close(fd);
1447         if (size < 0)
1448                 goto out;
1449         if (size == sizeof(value))
1450                 goto out;
1451
1452         /* got a valid value, store it in cache and return it */
1453         value[size] = '\0';
1454         util_remove_trailing_chars(value, '\n');
1455         list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, value);
1456         val = udev_list_entry_get_value(list_entry);
1457 out:
1458         return val;
1459 }
1460
1461 /**
1462  * udev_device_set_sysattr_value:
1463  * @udev_device: udev device
1464  * @sysattr: attribute name
1465  * @value: new value to be set
1466  *
1467  * Update the contents of the sys attribute and the cached value of the device.
1468  *
1469  * Returns: Negative error code on failure or 0 on success.
1470  **/
1471 _public_ int udev_device_set_sysattr_value(struct udev_device *udev_device, const char *sysattr, char *value)
1472 {
1473         struct udev_device *dev;
1474         char path[UTIL_PATH_SIZE];
1475         struct stat statbuf;
1476         int fd;
1477         ssize_t size, value_len;
1478         int ret = 0;
1479
1480         if (udev_device == NULL)
1481                 return -EINVAL;
1482         dev = udev_device;
1483         if (sysattr == NULL)
1484                 return -EINVAL;
1485         if (value == NULL)
1486                 value_len = 0;
1487         else
1488                 value_len = strlen(value);
1489
1490         strscpyl(path, sizeof(path), udev_device_get_syspath(dev), "/", sysattr, NULL);
1491         if (lstat(path, &statbuf) != 0) {
1492                 udev_list_entry_add(&dev->sysattr_value_list, sysattr, NULL);
1493                 ret = -ENXIO;
1494                 goto out;
1495         }
1496
1497         if (S_ISLNK(statbuf.st_mode)) {
1498                 ret = -EINVAL;
1499                 goto out;
1500         }
1501
1502         /* skip directories */
1503         if (S_ISDIR(statbuf.st_mode)) {
1504                 ret = -EISDIR;
1505                 goto out;
1506         }
1507
1508         /* skip non-readable files */
1509         if ((statbuf.st_mode & S_IRUSR) == 0) {
1510                 ret = -EACCES;
1511                 goto out;
1512         }
1513
1514         /* Value is limited to 4k */
1515         if (value_len > 4096) {
1516                 ret = -EINVAL;
1517                 goto out;
1518         }
1519         util_remove_trailing_chars(value, '\n');
1520
1521         /* write attribute value */
1522         fd = open(path, O_WRONLY|O_CLOEXEC);
1523         if (fd < 0) {
1524                 ret = -errno;
1525                 goto out;
1526         }
1527         size = write(fd, value, value_len);
1528         close(fd);
1529         if (size < 0) {
1530                 ret = -errno;
1531                 goto out;
1532         }
1533         if (size < value_len) {
1534                 ret = -EIO;
1535                 goto out;
1536         }
1537
1538         /* wrote a valid value, store it in cache and return it */
1539         udev_list_entry_add(&dev->sysattr_value_list, sysattr, value);
1540 out:
1541         if (dev != udev_device)
1542                 udev_device_unref(dev);
1543         return ret;
1544 }
1545
1546 static int udev_device_sysattr_list_read(struct udev_device *udev_device)
1547 {
1548         struct dirent *dent;
1549         DIR *dir;
1550         int num = 0;
1551
1552         if (udev_device == NULL)
1553                 return -EINVAL;
1554         if (udev_device->sysattr_list_read)
1555                 return 0;
1556
1557         dir = opendir(udev_device_get_syspath(udev_device));
1558         if (!dir)
1559                 return -errno;
1560
1561         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
1562                 char path[UTIL_PATH_SIZE];
1563                 struct stat statbuf;
1564
1565                 /* only handle symlinks and regular files */
1566                 if (dent->d_type != DT_LNK && dent->d_type != DT_REG)
1567                         continue;
1568
1569                 strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", dent->d_name, NULL);
1570                 if (lstat(path, &statbuf) != 0)
1571                         continue;
1572                 if ((statbuf.st_mode & S_IRUSR) == 0)
1573                         continue;
1574
1575                 udev_list_entry_add(&udev_device->sysattr_list, dent->d_name, NULL);
1576                 num++;
1577         }
1578
1579         closedir(dir);
1580         udev_device->sysattr_list_read = true;
1581
1582         return num;
1583 }
1584
1585 /**
1586  * udev_device_get_sysattr_list_entry:
1587  * @udev_device: udev device
1588  *
1589  * Retrieve the list of available sysattrs, with value being empty;
1590  * This just return all available sysfs attributes for a particular
1591  * device without reading their values.
1592  *
1593  * Returns: the first entry of the property list
1594  **/
1595 _public_ struct udev_list_entry *udev_device_get_sysattr_list_entry(struct udev_device *udev_device)
1596 {
1597         if (!udev_device->sysattr_list_read) {
1598                 int ret;
1599                 ret = udev_device_sysattr_list_read(udev_device);
1600                 if (0 > ret)
1601                         return NULL;
1602         }
1603
1604         return udev_list_get_entry(&udev_device->sysattr_list);
1605 }
1606
1607 int udev_device_set_syspath(struct udev_device *udev_device, const char *syspath)
1608 {
1609         const char *pos;
1610         size_t len;
1611
1612         free(udev_device->syspath);
1613         udev_device->syspath = strdup(syspath);
1614         if (udev_device->syspath ==  NULL)
1615                 return -ENOMEM;
1616         udev_device->devpath = udev_device->syspath + strlen("/sys");
1617         udev_device_add_property(udev_device, "DEVPATH", udev_device->devpath);
1618
1619         pos = strrchr(udev_device->syspath, '/');
1620         if (pos == NULL)
1621                 return -EINVAL;
1622         udev_device->sysname = strdup(&pos[1]);
1623         if (udev_device->sysname == NULL)
1624                 return -ENOMEM;
1625
1626         /* some devices have '!' in their name, change that to '/' */
1627         len = 0;
1628         while (udev_device->sysname[len] != '\0') {
1629                 if (udev_device->sysname[len] == '!')
1630                         udev_device->sysname[len] = '/';
1631                 len++;
1632         }
1633
1634         /* trailing number */
1635         while (len > 0 && isdigit(udev_device->sysname[--len]))
1636                 udev_device->sysnum = &udev_device->sysname[len];
1637
1638         /* sysname is completely numeric */
1639         if (len == 0)
1640                 udev_device->sysnum = NULL;
1641
1642         return 0;
1643 }
1644
1645 static int udev_device_set_devnode(struct udev_device *udev_device, const char *devnode)
1646 {
1647         free(udev_device->devnode);
1648         if (devnode[0] != '/') {
1649                 if (asprintf(&udev_device->devnode, "/dev/%s", devnode) < 0)
1650                         udev_device->devnode = NULL;
1651         } else {
1652                 udev_device->devnode = strdup(devnode);
1653         }
1654         if (udev_device->devnode == NULL)
1655                 return -ENOMEM;
1656         udev_device_add_property(udev_device, "DEVNAME", udev_device->devnode);
1657         return 0;
1658 }
1659
1660 int udev_device_add_devlink(struct udev_device *udev_device, const char *devlink)
1661 {
1662         struct udev_list_entry *list_entry;
1663
1664         udev_device->devlinks_uptodate = false;
1665         list_entry = udev_list_entry_add(&udev_device->devlinks_list, devlink, NULL);
1666         if (list_entry == NULL)
1667                 return -ENOMEM;
1668         return 0;
1669 }
1670
1671 const char *udev_device_get_id_filename(struct udev_device *udev_device)
1672 {
1673         if (udev_device->id_filename == NULL) {
1674                 if (udev_device_get_subsystem(udev_device) == NULL)
1675                         return NULL;
1676
1677                 if (major(udev_device_get_devnum(udev_device)) > 0) {
1678                         /* use dev_t -- b259:131072, c254:0 */
1679                         if (asprintf(&udev_device->id_filename, "%c%u:%u",
1680                                      streq(udev_device_get_subsystem(udev_device), "block") ? 'b' : 'c',
1681                                      major(udev_device_get_devnum(udev_device)),
1682                                      minor(udev_device_get_devnum(udev_device))) < 0)
1683                                 udev_device->id_filename = NULL;
1684                 } else if (udev_device_get_ifindex(udev_device) > 0) {
1685                         /* use netdev ifindex -- n3 */
1686                         if (asprintf(&udev_device->id_filename, "n%u", udev_device_get_ifindex(udev_device)) < 0)
1687                                 udev_device->id_filename = NULL;
1688                 } else {
1689                         /*
1690                          * use $subsys:$syname -- pci:0000:00:1f.2
1691                          * sysname() has '!' translated, get it from devpath
1692                          */
1693                         const char *sysname;
1694                         sysname = strrchr(udev_device->devpath, '/');
1695                         if (sysname == NULL)
1696                                 return NULL;
1697                         sysname = &sysname[1];
1698                         if (asprintf(&udev_device->id_filename, "+%s:%s", udev_device_get_subsystem(udev_device), sysname) < 0)
1699                                 udev_device->id_filename = NULL;
1700                 }
1701         }
1702         return udev_device->id_filename;
1703 }
1704
1705 /**
1706  * udev_device_get_is_initialized:
1707  * @udev_device: udev device
1708  *
1709  * Check if udev has already handled the device and has set up
1710  * device node permissions and context, or has renamed a network
1711  * device.
1712  *
1713  * This is only implemented for devices with a device node
1714  * or network interfaces. All other devices return 1 here.
1715  *
1716  * Returns: 1 if the device is set up. 0 otherwise.
1717  **/
1718 _public_ int udev_device_get_is_initialized(struct udev_device *udev_device)
1719 {
1720         if (!udev_device->info_loaded)
1721                 udev_device_read_db(udev_device, NULL);
1722         return udev_device->is_initialized;
1723 }
1724
1725 void udev_device_set_is_initialized(struct udev_device *udev_device)
1726 {
1727         udev_device->is_initialized = true;
1728 }
1729
1730 static bool is_valid_tag(const char *tag)
1731 {
1732         return !strchr(tag, ':') && !strchr(tag, ' ');
1733 }
1734
1735 int udev_device_add_tag(struct udev_device *udev_device, const char *tag)
1736 {
1737         if (!is_valid_tag(tag))
1738                 return -EINVAL;
1739         udev_device->tags_uptodate = false;
1740         if (udev_list_entry_add(&udev_device->tags_list, tag, NULL) != NULL)
1741                 return 0;
1742         return -ENOMEM;
1743 }
1744
1745 void udev_device_remove_tag(struct udev_device *udev_device, const char *tag)
1746 {
1747         struct udev_list_entry *e;
1748
1749         if (!is_valid_tag(tag))
1750                 return;
1751         e = udev_list_get_entry(&udev_device->tags_list);
1752         e = udev_list_entry_get_by_name(e, tag);
1753         if (e) {
1754                 udev_device->tags_uptodate = false;
1755                 udev_list_entry_delete(e);
1756         }
1757 }
1758
1759 void udev_device_cleanup_tags_list(struct udev_device *udev_device)
1760 {
1761         udev_device->tags_uptodate = false;
1762         udev_list_cleanup(&udev_device->tags_list);
1763 }
1764
1765 /**
1766  * udev_device_get_tags_list_entry:
1767  * @udev_device: udev device
1768  *
1769  * Retrieve the list of tags attached to the udev device. The next
1770  * list entry can be retrieved with udev_list_entry_get_next(),
1771  * which returns #NULL if no more entries exist. The tag string
1772  * can be retrieved from the list entry by udev_list_entry_get_name().
1773  *
1774  * Returns: the first entry of the tag list
1775  **/
1776 _public_ struct udev_list_entry *udev_device_get_tags_list_entry(struct udev_device *udev_device)
1777 {
1778         if (udev_device == NULL)
1779                 return NULL;
1780         if (!udev_device->info_loaded)
1781                 udev_device_read_db(udev_device, NULL);
1782         return udev_list_get_entry(&udev_device->tags_list);
1783 }
1784
1785 /**
1786  * udev_device_has_tag:
1787  * @udev_device: udev device
1788  * @tag: tag name
1789  *
1790  * Check if a given device has a certain tag associated.
1791  *
1792  * Returns: 1 if the tag is found. 0 otherwise.
1793  **/
1794 _public_ int udev_device_has_tag(struct udev_device *udev_device, const char *tag)
1795 {
1796         struct udev_list_entry *list_entry;
1797
1798         if (udev_device == NULL)
1799                 return false;
1800         if (!udev_device->info_loaded)
1801                 udev_device_read_db(udev_device, NULL);
1802         list_entry = udev_device_get_tags_list_entry(udev_device);
1803         if (udev_list_entry_get_by_name(list_entry, tag) != NULL)
1804                 return true;
1805         return false;
1806 }
1807
1808 #define ENVP_SIZE                        128
1809 #define MONITOR_BUF_SIZE                4096
1810 static int update_envp_monitor_buf(struct udev_device *udev_device)
1811 {
1812         struct udev_list_entry *list_entry;
1813         char *s;
1814         size_t l;
1815         unsigned int i;
1816
1817         /* monitor buffer of property strings */
1818         free(udev_device->monitor_buf);
1819         udev_device->monitor_buf_len = 0;
1820         udev_device->monitor_buf = malloc(MONITOR_BUF_SIZE);
1821         if (udev_device->monitor_buf == NULL)
1822                 return -ENOMEM;
1823
1824         /* envp array, strings will point into monitor buffer */
1825         if (udev_device->envp == NULL)
1826                 udev_device->envp = malloc(sizeof(char *) * ENVP_SIZE);
1827         if (udev_device->envp == NULL)
1828                 return -ENOMEM;
1829
1830         i = 0;
1831         s = udev_device->monitor_buf;
1832         l = MONITOR_BUF_SIZE;
1833         udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) {
1834                 const char *key;
1835
1836                 key = udev_list_entry_get_name(list_entry);
1837                 /* skip private variables */
1838                 if (key[0] == '.')
1839                         continue;
1840
1841                 /* add string to envp array */
1842                 udev_device->envp[i++] = s;
1843                 if (i+1 >= ENVP_SIZE)
1844                         return -EINVAL;
1845
1846                 /* add property string to monitor buffer */
1847                 l = strpcpyl(&s, l, key, "=", udev_list_entry_get_value(list_entry), NULL);
1848                 if (l == 0)
1849                         return -EINVAL;
1850                 /* advance past the trailing '\0' that strpcpyl() guarantees */
1851                 s++;
1852                 l--;
1853         }
1854         udev_device->envp[i] = NULL;
1855         udev_device->monitor_buf_len = s - udev_device->monitor_buf;
1856         udev_device->envp_uptodate = true;
1857         return 0;
1858 }
1859
1860 char **udev_device_get_properties_envp(struct udev_device *udev_device)
1861 {
1862         if (!udev_device->envp_uptodate)
1863                 if (update_envp_monitor_buf(udev_device) != 0)
1864                         return NULL;
1865         return udev_device->envp;
1866 }
1867
1868 ssize_t udev_device_get_properties_monitor_buf(struct udev_device *udev_device, const char **buf)
1869 {
1870         if (!udev_device->envp_uptodate)
1871                 if (update_envp_monitor_buf(udev_device) != 0)
1872                         return -EINVAL;
1873         *buf = udev_device->monitor_buf;
1874         return udev_device->monitor_buf_len;
1875 }
1876
1877 int udev_device_set_action(struct udev_device *udev_device, const char *action)
1878 {
1879         free(udev_device->action);
1880         udev_device->action = strdup(action);
1881         if (udev_device->action == NULL)
1882                 return -ENOMEM;
1883         udev_device_add_property(udev_device, "ACTION", udev_device->action);
1884         return 0;
1885 }
1886
1887 int udev_device_get_devlink_priority(struct udev_device *udev_device)
1888 {
1889         if (!udev_device->info_loaded)
1890                 udev_device_read_db(udev_device, NULL);
1891         return udev_device->devlink_priority;
1892 }
1893
1894 int udev_device_set_devlink_priority(struct udev_device *udev_device, int prio)
1895 {
1896          udev_device->devlink_priority = prio;
1897         return 0;
1898 }
1899
1900 int udev_device_get_watch_handle(struct udev_device *udev_device)
1901 {
1902         if (!udev_device->info_loaded)
1903                 udev_device_read_db(udev_device, NULL);
1904         return udev_device->watch_handle;
1905 }
1906
1907 int udev_device_set_watch_handle(struct udev_device *udev_device, int handle)
1908 {
1909         udev_device->watch_handle = handle;
1910         return 0;
1911 }
1912
1913 bool udev_device_get_db_persist(struct udev_device *udev_device)
1914 {
1915         return udev_device->db_persist;
1916 }
1917
1918 void udev_device_set_db_persist(struct udev_device *udev_device)
1919 {
1920         udev_device->db_persist = true;
1921 }