udev/lib/libudev-enumerate.c

   1 /*
   2  * libudev - interface to udev device information
   3  *
   4  * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  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 <errno.h>
  25 #include <string.h>
  26 #include <dirent.h>
  27 #include <fnmatch.h>
  28 #include <sys/stat.h>
  29
  30 #include "libudev.h"
  31 #include "libudev-private.h"
  32
  33 static int devices_sort(struct udev_enumerate *udev_enumerate);
  34
  35 struct udev_enumerate {
  36         struct udev *udev;
  37         int refcount;
  38         struct udev_list_node sysattr_match_list;
  39         struct udev_list_node sysattr_nomatch_list;
  40         struct udev_list_node subsystem_match_list;
  41         struct udev_list_node subsystem_nomatch_list;
  42         struct udev_list_node properties_match_list;
  43         struct udev_list_node devices_list;
  44         int devices_sorted;
  45 };
  46
  47 /**
  48  * udev_enumerate_new:
  49  * @udev: udev library context
  50  *
  51  * Returns: an enumeration context
  52  **/
  53 struct udev_enumerate *udev_enumerate_new(struct udev *udev)
  54 {
  55         struct udev_enumerate *udev_enumerate;
  56
  57         udev_enumerate = calloc(1, sizeof(struct udev_enumerate));
  58         if (udev_enumerate == NULL)
  59                 return NULL;
  60         udev_enumerate->refcount = 1;
  61         udev_enumerate->udev = udev;
  62         udev_list_init(&udev_enumerate->devices_list);
  63         udev_list_init(&udev_enumerate->sysattr_match_list);
  64         udev_list_init(&udev_enumerate->sysattr_nomatch_list);
  65         udev_list_init(&udev_enumerate->subsystem_match_list);
  66         udev_list_init(&udev_enumerate->subsystem_nomatch_list);
  67         udev_list_init(&udev_enumerate->properties_match_list);
  68         return udev_enumerate;
  69 }
  70
  71 struct udev_enumerate *udev_enumerate_ref(struct udev_enumerate *udev_enumerate)
  72 {
  73         if (udev_enumerate == NULL)
  74                 return NULL;
  75         udev_enumerate->refcount++;
  76         return udev_enumerate;
  77 }
  78
  79 void udev_enumerate_unref(struct udev_enumerate *udev_enumerate)
  80 {
  81         if (udev_enumerate == NULL)
  82                 return;
  83         udev_enumerate->refcount--;
  84         if (udev_enumerate->refcount > 0)
  85                 return;
  86         udev_list_cleanup_entries(udev_enumerate->udev, &udev_enumerate->devices_list);
  87         udev_list_cleanup_entries(udev_enumerate->udev, &udev_enumerate->sysattr_match_list);
  88         udev_list_cleanup_entries(udev_enumerate->udev, &udev_enumerate->sysattr_nomatch_list);
  89         udev_list_cleanup_entries(udev_enumerate->udev, &udev_enumerate->subsystem_match_list);
  90         udev_list_cleanup_entries(udev_enumerate->udev, &udev_enumerate->subsystem_nomatch_list);
  91         udev_list_cleanup_entries(udev_enumerate->udev, &udev_enumerate->properties_match_list);
  92         free(udev_enumerate);
  93 }
  94
  95 struct udev *udev_enumerate_get_udev(struct udev_enumerate *udev_enumerate)
  96 {
  97         if (udev_enumerate == NULL)
  98                 return NULL;
  99         return udev_enumerate->udev;
 100 }
 101
 102 struct udev_list_entry *udev_enumerate_get_list_entry(struct udev_enumerate *udev_enumerate)
 103 {
 104         if (udev_enumerate == NULL)
 105                 return NULL;
 106         if (!udev_enumerate->devices_sorted)
 107                 devices_sort(udev_enumerate);
 108         return udev_list_get_entry(&udev_enumerate->devices_list);
 109 }
 110
 111 int udev_enumerate_add_match_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
 112 {
 113         if (udev_enumerate == NULL)
 114                 return -EINVAL;
 115         if (subsystem == NULL)
 116                 return 0;
 117         if (udev_list_entry_add(udev_enumerate_get_udev(udev_enumerate),
 118                                 &udev_enumerate->subsystem_match_list, subsystem, NULL, 1, 0) == NULL)
 119                 return -ENOMEM;
 120         return 0;
 121 }
 122
 123 int udev_enumerate_add_nomatch_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
 124 {
 125         if (udev_enumerate == NULL)
 126                 return -EINVAL;
 127         if (subsystem == NULL)
 128                 return 0;
 129         if (udev_list_entry_add(udev_enumerate_get_udev(udev_enumerate),
 130                                 &udev_enumerate->subsystem_nomatch_list, subsystem, NULL, 1, 0) == NULL)
 131                 return -ENOMEM;
 132         return 0;
 133 }
 134
 135 int udev_enumerate_add_match_sysattr(struct udev_enumerate *udev_enumerate, const char *sysattr, const char *value)
 136 {
 137         if (udev_enumerate == NULL)
 138                 return -EINVAL;
 139         if (sysattr == NULL)
 140                 return 0;
 141         if (udev_list_entry_add(udev_enumerate_get_udev(udev_enumerate),
 142                            &udev_enumerate->sysattr_match_list, sysattr, value, 1, 0) == NULL)
 143                 return -ENOMEM;
 144         return 0;
 145 }
 146
 147 int udev_enumerate_add_nomatch_sysattr(struct udev_enumerate *udev_enumerate, const char *sysattr, const char *value)
 148 {
 149         if (udev_enumerate == NULL)
 150                 return -EINVAL;
 151         if (sysattr == NULL)
 152                 return 0;
 153         if (udev_list_entry_add(udev_enumerate_get_udev(udev_enumerate),
 154                            &udev_enumerate->sysattr_nomatch_list, sysattr, value, 1, 0) == NULL)
 155                 return -ENOMEM;
 156         return 0;
 157 }
 158
 159 static int match_sysattr_value(struct udev *udev, const char *syspath, const char *sysattr, const char *match_val)
 160 {
 161         struct udev_device *device;
 162         const char *val = NULL;
 163         int match = 0;
 164
 165         device = udev_device_new_from_syspath(udev, syspath);
 166         if (device == NULL)
 167                 return -EINVAL;
 168         val = udev_device_get_sysattr_value(device, sysattr);
 169         if (val == NULL)
 170                 goto exit;
 171         if (match_val == NULL) {
 172                 match = 1;
 173                 goto exit;
 174         }
 175         if (fnmatch(match_val, val, 0) == 0) {
 176                 match = 1;
 177                 goto exit;
 178         }
 179 exit:
 180         udev_device_unref(device);
 181         return match;
 182 }
 183
 184 int udev_enumerate_add_match_property(struct udev_enumerate *udev_enumerate, const char *property, const char *value)
 185 {
 186         if (udev_enumerate == NULL)
 187                 return -EINVAL;
 188         if (property == NULL)
 189                 return 0;
 190         if (udev_list_entry_add(udev_enumerate_get_udev(udev_enumerate),
 191                                 &udev_enumerate->properties_match_list, property, value, 1, 0) == NULL)
 192                 return -ENOMEM;
 193         return 0;
 194 }
 195
 196 static int match_sysattr(struct udev_enumerate *udev_enumerate, const char *syspath)
 197 {
 198         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 199         struct udev_list_entry *list_entry;
 200
 201         /* skip list */
 202         udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->sysattr_nomatch_list)) {
 203                 if (match_sysattr_value(udev, syspath,
 204                                      udev_list_entry_get_name(list_entry),
 205                                      udev_list_entry_get_value(list_entry)))
 206                         return 0;
 207         }
 208         /* include list */
 209         if (udev_list_get_entry(&udev_enumerate->sysattr_match_list) != NULL) {
 210                 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->sysattr_match_list)) {
 211                         /* anything that does not match, will make it FALSE */
 212                         if (!match_sysattr_value(udev, syspath,
 213                                               udev_list_entry_get_name(list_entry),
 214                                               udev_list_entry_get_value(list_entry)))
 215                                 return 0;
 216                 }
 217                 return 1;
 218         }
 219         return 1;
 220 }
 221
 222 static int match_property(struct udev_enumerate *udev_enumerate, const char *syspath)
 223 {
 224         struct udev_device *dev;
 225         struct udev_list_entry *list_entry;
 226         int match = 0;
 227
 228         /* no match always matches */
 229         if (udev_list_get_entry(&udev_enumerate->properties_match_list) == NULL)
 230                 return 1;
 231
 232         /* no device does not match */
 233         dev = udev_device_new_from_syspath(udev_enumerate->udev, syspath);
 234         if (dev == NULL)
 235                 return 0;
 236
 237         /* loop over matches */
 238         udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->properties_match_list)) {
 239                 struct udev_list_entry *property_entry;
 240
 241                 /* loop over device properties */
 242                 udev_list_entry_foreach(property_entry, udev_device_get_properties_list_entry(dev)) {
 243                         if (fnmatch(udev_list_entry_get_name(list_entry), udev_list_entry_get_name(property_entry), 0) == 0) {
 244                                 const char *match_value;
 245                                 const char *dev_value;
 246
 247                                 match_value = udev_list_entry_get_value(list_entry);
 248                                 dev_value = udev_list_entry_get_value(property_entry);
 249                                 if (match_value == NULL && dev_value == NULL) {
 250                                         match = 1;
 251                                         goto out;
 252                                 }
 253                                 if (match_value == NULL || dev_value == NULL)
 254                                         continue;
 255                                 if (fnmatch(match_value, dev_value, 0) == 0) {
 256                                         match = 1;
 257                                         goto out;
 258                                 }
 259                         }
 260                 }
 261         }
 262 out:
 263         udev_device_unref(dev);
 264         return match;
 265 }
 266
 267 static int scan_dir_and_add_devices(struct udev_enumerate *udev_enumerate,
 268                                     const char *basedir, const char *subdir1, const char *subdir2)
 269 {
 270         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 271         char path[UTIL_PATH_SIZE];
 272         DIR *dir;
 273         struct dirent *dent;
 274
 275         util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
 276         util_strlcat(path, "/", sizeof(path));
 277         util_strlcat(path, basedir, sizeof(path));
 278         if (subdir1 != NULL) {
 279                 util_strlcat(path, "/", sizeof(path));
 280                 util_strlcat(path, subdir1, sizeof(path));
 281         }
 282         if (subdir2 != NULL) {
 283                 util_strlcat(path, "/", sizeof(path));
 284                 util_strlcat(path, subdir2, sizeof(path));
 285         }
 286         dir = opendir(path);
 287         if (dir == NULL)
 288                 return -1;
 289         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 290                 char syspath[UTIL_PATH_SIZE];
 291                 char filename[UTIL_PATH_SIZE];
 292                 struct stat statbuf;
 293
 294                 if (dent->d_name[0] == '.')
 295                         continue;
 296                 util_strlcpy(syspath, path, sizeof(syspath));
 297                 util_strlcat(syspath, "/", sizeof(syspath));
 298                 util_strlcat(syspath, dent->d_name, sizeof(syspath));
 299                 if (lstat(syspath, &statbuf) != 0)
 300                         continue;
 301                 if (S_ISREG(statbuf.st_mode))
 302                         continue;
 303                 if (S_ISLNK(statbuf.st_mode))
 304                         util_resolve_sys_link(udev, syspath, sizeof(syspath));
 305                 util_strlcpy(filename, syspath, sizeof(filename));
 306                 util_strlcat(filename, "/uevent", sizeof(filename));
 307                 if (stat(filename, &statbuf) != 0)
 308                         continue;
 309                 if (!match_sysattr(udev_enumerate, syspath))
 310                         continue;
 311                 if (!match_property(udev_enumerate, syspath))
 312                         continue;
 313                 udev_list_entry_add(udev, &udev_enumerate->devices_list, syspath, NULL, 1, 1);
 314         }
 315         closedir(dir);
 316         return 0;
 317 }
 318
 319 static int match_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
 320 {
 321         struct udev_list_entry *list_entry;
 322
 323         udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_nomatch_list)) {
 324                 if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
 325                         return 0;
 326         }
 327         if (udev_list_get_entry(&udev_enumerate->subsystem_match_list) != NULL) {
 328                 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_match_list)) {
 329                         if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
 330                                 return 1;
 331                 }
 332                 return 0;
 333         }
 334         return 1;
 335 }
 336
 337 static int scan_dir(struct udev_enumerate *udev_enumerate, const char *basedir, const char *subdir, const char *subsystem)
 338 {
 339         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 340
 341         char path[UTIL_PATH_SIZE];
 342         DIR *dir;
 343         struct dirent *dent;
 344
 345         util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
 346         util_strlcat(path, "/", sizeof(path));
 347         util_strlcat(path, basedir, sizeof(path));
 348         dir = opendir(path);
 349         if (dir == NULL)
 350                 return -1;
 351         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 352                 if (dent->d_name[0] == '.')
 353                         continue;
 354                 if (!match_subsystem(udev_enumerate, subsystem != NULL ? subsystem : dent->d_name))
 355                         continue;
 356                 scan_dir_and_add_devices(udev_enumerate, basedir, dent->d_name, subdir);
 357         }
 358         closedir(dir);
 359         return 0;
 360 }
 361
 362 static int devices_delay(struct udev *udev, const char *syspath)
 363 {
 364         static const char *delay_device_list[] = {
 365                 "/block/md",
 366                 "/block/dm-",
 367                 NULL
 368         };
 369         size_t len;
 370         int i;
 371
 372         len = strlen(udev_get_sys_path(udev));
 373         for (i = 0; delay_device_list[i] != NULL; i++) {
 374                 if (strstr(&syspath[len], delay_device_list[i]) != NULL) {
 375                         dbg(udev, "delaying: %s\n", syspath);
 376                         return 1;
 377                 }
 378         }
 379         return 0;
 380 }
 381
 382 /* sort delayed devices to the end of the list */
 383 static int devices_sort(struct udev_enumerate *udev_enumerate)
 384 {
 385         struct udev_list_entry *entry_loop;
 386         struct udev_list_entry *entry_tmp;
 387         struct udev_list_node devices_list;
 388
 389         udev_list_init(&devices_list);
 390         /* move delayed to delay list */
 391         udev_list_entry_foreach_safe(entry_loop, entry_tmp, udev_list_get_entry(&udev_enumerate->devices_list)) {
 392                 if (devices_delay(udev_enumerate->udev, udev_list_entry_get_name(entry_loop))) {
 393                         udev_list_entry_remove(entry_loop);
 394                         udev_list_entry_append(entry_loop, &devices_list);
 395                 }
 396         }
 397         /* move delayed back to end of list */
 398         udev_list_entry_foreach_safe(entry_loop, entry_tmp, udev_list_get_entry(&devices_list)) {
 399                 udev_list_entry_remove(entry_loop);
 400                 udev_list_entry_append(entry_loop, &udev_enumerate->devices_list);
 401         }
 402         udev_enumerate->devices_sorted = 1;
 403         return 0;
 404 }
 405
 406 int udev_enumerate_add_syspath(struct udev_enumerate *udev_enumerate, const char *syspath)
 407 {
 408         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 409         struct udev_device *udev_device;
 410
 411         if (udev_enumerate == NULL)
 412                 return -EINVAL;
 413         if (syspath == NULL)
 414                 return 0;
 415         /* resolve to real syspath */
 416         udev_device = udev_device_new_from_syspath(udev_enumerate->udev, syspath);
 417         if (udev_device == NULL)
 418                 return -EINVAL;
 419         udev_list_entry_add(udev, &udev_enumerate->devices_list,
 420                             udev_device_get_syspath(udev_device), NULL, 1, 1);
 421         udev_device_unref(udev_device);
 422         return 0;
 423 }
 424
 425 /**
 426  * udev_enumerate_scan_devices:
 427  * @udev_enumerate: udev enumeration context
 428  *
 429  * Returns: a negative value on error.
 430  **/
 431 int udev_enumerate_scan_devices(struct udev_enumerate *udev_enumerate)
 432 {
 433         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 434         char base[UTIL_PATH_SIZE];
 435         struct stat statbuf;
 436
 437         if (udev_enumerate == NULL)
 438                 return -EINVAL;
 439         util_strlcpy(base, udev_get_sys_path(udev), sizeof(base));
 440         util_strlcat(base, "/subsystem", sizeof(base));
 441         if (stat(base, &statbuf) == 0) {
 442                 /* we have /subsystem/, forget all the old stuff */
 443                 dbg(udev, "searching '/subsystem/*/devices/*' dir\n");
 444                 scan_dir(udev_enumerate, "subsystem", "devices", NULL);
 445         } else {
 446                 dbg(udev, "searching '/bus/*/devices/*' dir\n");
 447                 scan_dir(udev_enumerate, "bus", "devices", NULL);
 448                 dbg(udev, "searching '/class/*' dir\n");
 449                 scan_dir(udev_enumerate, "class", NULL, NULL);
 450                 /* if block isn't a class, scan /block/ */
 451                 util_strlcpy(base, udev_get_sys_path(udev), sizeof(base));
 452                 util_strlcat(base, "/class/block", sizeof(base));
 453                 if (stat(base, &statbuf) != 0) {
 454                         if (match_subsystem(udev_enumerate, "block")) {
 455                                 dbg(udev, "searching '/block/*' dir\n");
 456                                 /* scan disks */
 457                                 scan_dir_and_add_devices(udev_enumerate, "block", NULL, NULL);
 458                                 /* scan partitions */
 459                                 dbg(udev, "searching '/block/*/*' dir\n");
 460                                 scan_dir(udev_enumerate, "block", NULL, "block");
 461                         }
 462                 }
 463         }
 464         return 0;
 465 }
 466
 467 /**
 468  * udev_enumerate_scan_subsystems:
 469  * @udev_enumerate: udev enumeration context
 470  *
 471  * Returns: a negative value on error.
 472  **/
 473 int udev_enumerate_scan_subsystems(struct udev_enumerate *udev_enumerate)
 474 {
 475         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 476         char base[UTIL_PATH_SIZE];
 477         struct stat statbuf;
 478         const char *subsysdir;
 479
 480         if (udev_enumerate == NULL)
 481                 return -EINVAL;
 482         util_strlcpy(base, udev_get_sys_path(udev), sizeof(base));
 483         util_strlcat(base, "/subsystem", sizeof(base));
 484         if (stat(base, &statbuf) == 0)
 485                 subsysdir = "subsystem";
 486         else
 487                 subsysdir = "bus";
 488         if (match_subsystem(udev_enumerate, "subsystem")) {
 489                 dbg(udev, "searching '%s/*' dir\n", subsysdir);
 490                 scan_dir_and_add_devices(udev_enumerate, subsysdir, NULL, NULL);
 491         }
 492         if (match_subsystem(udev_enumerate, "drivers")) {
 493                 dbg(udev, "searching '%s/*/drivers/*' dir\n", subsysdir);
 494                 scan_dir(udev_enumerate, subsysdir, "drivers", "drivers");
 495         }
 496         return 0;
 497 }