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 struct udev_enumerate {
  34         struct udev *udev;
  35         int refcount;
  36         struct list_node attr_match_list;
  37         struct list_node attr_nomatch_list;
  38         struct list_node subsystem_match_list;
  39         struct list_node subsystem_nomatch_list;
  40         struct list_node devices_list;
  41 };
  42
  43 /**
  44  * udev_enumerate_new:
  45  * @udev: udev library context
  46  *
  47  * Returns: an enumeration context
  48  **/
  49 struct udev_enumerate *udev_enumerate_new(struct udev *udev)
  50 {
  51         struct udev_enumerate *udev_enumerate;
  52
  53         udev_enumerate = malloc(sizeof(struct udev_enumerate));
  54         if (udev_enumerate == NULL)
  55                 return NULL;
  56         memset(udev_enumerate, 0x00, (sizeof(struct udev_enumerate)));
  57         udev_enumerate->refcount = 1;
  58         udev_enumerate->udev = udev;
  59         list_init(&udev_enumerate->devices_list);
  60         list_init(&udev_enumerate->attr_match_list);
  61         list_init(&udev_enumerate->attr_nomatch_list);
  62         list_init(&udev_enumerate->subsystem_match_list);
  63         list_init(&udev_enumerate->subsystem_nomatch_list);
  64         return udev_enumerate;
  65 }
  66
  67 struct udev_enumerate *udev_enumerate_ref(struct udev_enumerate *udev_enumerate)
  68 {
  69         if (udev_enumerate == NULL)
  70                 return NULL;
  71         udev_enumerate->refcount++;
  72         return udev_enumerate;
  73 }
  74
  75 void udev_enumerate_unref(struct udev_enumerate *udev_enumerate)
  76 {
  77         if (udev_enumerate == NULL)
  78                 return;
  79         udev_enumerate->refcount--;
  80         if (udev_enumerate->refcount > 0)
  81                 return;
  82         list_cleanup(udev_enumerate->udev, &udev_enumerate->devices_list);
  83         list_cleanup(udev_enumerate->udev, &udev_enumerate->attr_match_list);
  84         list_cleanup(udev_enumerate->udev, &udev_enumerate->attr_nomatch_list);
  85         list_cleanup(udev_enumerate->udev, &udev_enumerate->subsystem_match_list);
  86         list_cleanup(udev_enumerate->udev, &udev_enumerate->subsystem_nomatch_list);
  87         free(udev_enumerate);
  88 }
  89
  90 struct udev *udev_enumerate_get_udev(struct udev_enumerate *udev_enumerate)
  91 {
  92         if (udev_enumerate == NULL)
  93                 return NULL;
  94         return udev_enumerate->udev;
  95 }
  96
  97 struct udev_list_entry *udev_enumerate_get_list_entry(struct udev_enumerate *udev_enumerate)
  98 {
  99         if (udev_enumerate == NULL)
 100                 return NULL;
 101         return list_get_entry(&udev_enumerate->devices_list);
 102 }
 103
 104 int udev_enumerate_add_match_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
 105 {
 106         if (udev_enumerate == NULL)
 107                 return -EINVAL;
 108         if (subsystem == NULL)
 109                 return 0;
 110         if (list_entry_add(udev_enumerate_get_udev(udev_enumerate),
 111                            &udev_enumerate->subsystem_match_list, subsystem, NULL, 1, 0) == NULL)
 112                 return -ENOMEM;
 113         return 0;
 114 }
 115
 116 int udev_enumerate_add_nomatch_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
 117 {
 118         if (udev_enumerate == NULL)
 119                 return -EINVAL;
 120         if (subsystem == NULL)
 121                 return 0;
 122         if (list_entry_add(udev_enumerate_get_udev(udev_enumerate),
 123                            &udev_enumerate->subsystem_nomatch_list, subsystem, NULL, 1, 0) == NULL)
 124                 return -ENOMEM;
 125         return 0;
 126 }
 127
 128 int udev_enumerate_add_match_attr(struct udev_enumerate *udev_enumerate, const char *attr, const char *value)
 129 {
 130         if (udev_enumerate == NULL)
 131                 return -EINVAL;
 132         if (attr == NULL)
 133                 return 0;
 134         if (list_entry_add(udev_enumerate_get_udev(udev_enumerate),
 135                            &udev_enumerate->attr_match_list, attr, value, 1, 0) == NULL)
 136                 return -ENOMEM;
 137         return 0;
 138 }
 139
 140 int udev_enumerate_add_nomatch_attr(struct udev_enumerate *udev_enumerate, const char *attr, const char *value)
 141 {
 142         if (udev_enumerate == NULL)
 143                 return -EINVAL;
 144         if (attr == NULL)
 145                 return 0;
 146         if (list_entry_add(udev_enumerate_get_udev(udev_enumerate),
 147                            &udev_enumerate->attr_nomatch_list, attr, value, 1, 0) == NULL)
 148                 return -ENOMEM;
 149         return 0;
 150 }
 151
 152 static int match_attr_value(struct udev *udev, const char *syspath, const char *attr, const char *match_val)
 153 {
 154         struct udev_device *device;
 155         const char *val = NULL;
 156         int match = 0;
 157
 158         device = udev_device_new_from_syspath(udev, syspath);
 159         if (device == NULL)
 160                 return -EINVAL;
 161         val = udev_device_get_attr_value(device, attr);
 162         if (val == NULL)
 163                 goto exit;
 164         if (match_val == NULL) {
 165                 match = 1;
 166                 goto exit;
 167         }
 168         if (fnmatch(match_val, val, 0) == 0) {
 169                 match = 1;
 170                 goto exit;
 171         }
 172 exit:
 173         udev_device_unref(device);
 174         return match;
 175 }
 176
 177 static int match_attr(struct udev_enumerate *udev_enumerate, const char *syspath)
 178 {
 179         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 180         struct udev_list_entry *list_entry;
 181
 182         /* skip list */
 183         udev_list_entry_foreach(list_entry, list_get_entry(&udev_enumerate->attr_nomatch_list)) {
 184                 if (match_attr_value(udev, syspath,
 185                                      udev_list_entry_get_name(list_entry),
 186                                      udev_list_entry_get_value(list_entry)))
 187                         return 0;
 188         }
 189         /* include list */
 190         if (list_get_entry(&udev_enumerate->attr_match_list) != NULL) {
 191                 udev_list_entry_foreach(list_entry, list_get_entry(&udev_enumerate->attr_match_list)) {
 192                         /* anything that does not match, will make it FALSE */
 193                         if (!match_attr_value(udev, syspath,
 194                                               udev_list_entry_get_name(list_entry),
 195                                               udev_list_entry_get_value(list_entry)))
 196                                 return 0;
 197                 }
 198                 return 1;
 199         }
 200         return 1;
 201 }
 202
 203 static int scan_dir_and_add_devices(struct udev_enumerate *udev_enumerate,
 204                                     const char *basedir, const char *subdir1, const char *subdir2)
 205 {
 206         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 207         char path[UTIL_PATH_SIZE];
 208         DIR *dir;
 209         struct dirent *dent;
 210
 211         util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
 212         util_strlcat(path, "/", sizeof(path));
 213         util_strlcat(path, basedir, sizeof(path));
 214         if (subdir1 != NULL) {
 215                 util_strlcat(path, "/", sizeof(path));
 216                 util_strlcat(path, subdir1, sizeof(path));
 217         }
 218         if (subdir2 != NULL) {
 219                 util_strlcat(path, "/", sizeof(path));
 220                 util_strlcat(path, subdir2, sizeof(path));
 221         }
 222         dir = opendir(path);
 223         if (dir == NULL)
 224                 return -1;
 225         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 226                 char syspath[UTIL_PATH_SIZE];
 227                 char filename[UTIL_PATH_SIZE];
 228                 struct stat statbuf;
 229
 230                 if (dent->d_name[0] == '.')
 231                         continue;
 232                 util_strlcpy(syspath, path, sizeof(syspath));
 233                 util_strlcat(syspath, "/", sizeof(syspath));
 234                 util_strlcat(syspath, dent->d_name, sizeof(syspath));
 235                 if (lstat(syspath, &statbuf) != 0)
 236                         continue;
 237                 if (S_ISREG(statbuf.st_mode))
 238                         continue;
 239                 if (S_ISLNK(statbuf.st_mode))
 240                         util_resolve_sys_link(udev, syspath, sizeof(syspath));
 241                 util_strlcpy(filename, syspath, sizeof(filename));
 242                 util_strlcat(filename, "/uevent", sizeof(filename));
 243                 if (stat(filename, &statbuf) != 0)
 244                         continue;
 245                 if (!match_attr(udev_enumerate, syspath))
 246                         continue;
 247                 list_entry_add(udev, &udev_enumerate->devices_list, syspath, NULL, 1, 1);
 248         }
 249         closedir(dir);
 250         return 0;
 251 }
 252
 253 static int match_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
 254 {
 255         struct udev_list_entry *list_entry;
 256
 257         udev_list_entry_foreach(list_entry, list_get_entry(&udev_enumerate->subsystem_nomatch_list)) {
 258                 if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
 259                         return 0;
 260         }
 261         if (list_get_entry(&udev_enumerate->subsystem_match_list) != NULL) {
 262                 udev_list_entry_foreach(list_entry, list_get_entry(&udev_enumerate->subsystem_match_list)) {
 263                         if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
 264                                 return 1;
 265                 }
 266                 return 0;
 267         }
 268         return 1;
 269 }
 270
 271 static int scan_dir(struct udev_enumerate *udev_enumerate, const char *basedir, const char *subdir, const char *subsystem)
 272 {
 273         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 274
 275         char path[UTIL_PATH_SIZE];
 276         DIR *dir;
 277         struct dirent *dent;
 278
 279         util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
 280         util_strlcat(path, "/", sizeof(path));
 281         util_strlcat(path, basedir, sizeof(path));
 282         dir = opendir(path);
 283         if (dir == NULL)
 284                 return -1;
 285         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 286                 if (dent->d_name[0] == '.')
 287                         continue;
 288                 if (!match_subsystem(udev_enumerate, subsystem != NULL ? subsystem : dent->d_name))
 289                         continue;
 290                 scan_dir_and_add_devices(udev_enumerate, basedir, dent->d_name, subdir);
 291         }
 292         closedir(dir);
 293         return 0;
 294 }
 295
 296 static int devices_delay(struct udev *udev, const char *syspath)
 297 {
 298         static const char *delay_device_list[] = {
 299                 "/block/md",
 300                 "/block/dm-",
 301                 NULL
 302         };
 303         size_t len;
 304         int i;
 305
 306         len = strlen(udev_get_sys_path(udev));
 307         for (i = 0; delay_device_list[i] != NULL; i++) {
 308                 if (strstr(&syspath[len], delay_device_list[i]) != NULL) {
 309                         info(udev, "delaying: %s\n", syspath);
 310                         return 1;
 311                 }
 312         }
 313         return 0;
 314 }
 315
 316 int udev_enumerate_add_device(struct udev_enumerate *udev_enumerate, struct udev_device *udev_device)
 317 {
 318         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 319         struct udev_list_entry *list_entry;
 320
 321         if (udev_enumerate == NULL)
 322                 return -EINVAL;
 323         if (udev_device == NULL)
 324                 return 0;
 325         list_entry_add(udev,
 326                        &udev_enumerate->devices_list,
 327                        udev_device_get_syspath(udev_device), NULL, 1, 1);
 328         /* sort delayed devices to the end of the list */
 329         udev_list_entry_foreach(list_entry, list_get_entry(&udev_enumerate->devices_list)) {
 330                 if (devices_delay(udev, udev_list_entry_get_name(list_entry)))
 331                         list_entry_move_to_end(list_entry);
 332         }
 333         return 0;
 334 }
 335
 336 /**
 337  * udev_enumerate_scan_devices:
 338  * @udev_enumerate: udev enumeration context
 339  *
 340  * Returns: a negative value on error.
 341  **/
 342 int udev_enumerate_scan_devices(struct udev_enumerate *udev_enumerate)
 343 {
 344         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 345         char base[UTIL_PATH_SIZE];
 346         struct stat statbuf;
 347         struct udev_list_entry *list_entry;
 348
 349         if (udev_enumerate == NULL)
 350                 return -EINVAL;
 351         util_strlcpy(base, udev_get_sys_path(udev), sizeof(base));
 352         util_strlcat(base, "/subsystem", sizeof(base));
 353         if (stat(base, &statbuf) == 0) {
 354                 /* we have /subsystem/, forget all the old stuff */
 355                 info(udev, "searching '/subsystem/*/devices/*' dir\n");
 356                 scan_dir(udev_enumerate, "subsystem", "devices", NULL);
 357         } else {
 358                 info(udev, "searching '/bus/*/devices/*' dir\n");
 359                 scan_dir(udev_enumerate, "bus", "devices", NULL);
 360                 info(udev, "searching '/class/*' dir\n");
 361                 scan_dir(udev_enumerate, "class", NULL, NULL);
 362                 /* if block isn't a class, scan /block/ */
 363                 util_strlcpy(base, udev_get_sys_path(udev), sizeof(base));
 364                 util_strlcat(base, "/class/block", sizeof(base));
 365                 if (stat(base, &statbuf) != 0) {
 366                         if (match_subsystem(udev_enumerate, "block")) {
 367                                 info(udev, "searching '/block/*' dir\n");
 368                                 /* scan disks */
 369                                 scan_dir_and_add_devices(udev_enumerate, "block", NULL, NULL);
 370                                 /* scan partitions */
 371                                 info(udev, "searching '/block/*/*' dir\n");
 372                                 scan_dir(udev_enumerate, "block", NULL, "block");
 373                         }
 374                 }
 375         }
 376         /* sort delayed devices to the end of the list */
 377         udev_list_entry_foreach(list_entry, list_get_entry(&udev_enumerate->devices_list)) {
 378                 if (devices_delay(udev, udev_list_entry_get_name(list_entry)))
 379                         list_entry_move_to_end(list_entry);
 380         }
 381         return 0;
 382 }
 383
 384 /**
 385  * udev_enumerate_scan_subsystems:
 386  * @udev_enumerate: udev enumeration context
 387  *
 388  * Returns: a negative value on error.
 389  **/
 390 int udev_enumerate_scan_subsystems(struct udev_enumerate *udev_enumerate)
 391 {
 392         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 393         char base[UTIL_PATH_SIZE];
 394         struct stat statbuf;
 395         const char *subsysdir;
 396
 397         if (udev_enumerate == NULL)
 398                 return -EINVAL;
 399         util_strlcpy(base, udev_get_sys_path(udev), sizeof(base));
 400         util_strlcat(base, "/subsystem", sizeof(base));
 401         if (stat(base, &statbuf) == 0)
 402                 subsysdir = "subsystem";
 403         else
 404                 subsysdir = "bus";
 405         if (match_subsystem(udev_enumerate, "subsystem")) {
 406                 info(udev, "searching '%s/*' dir\n", subsysdir);
 407                 scan_dir_and_add_devices(udev_enumerate, subsysdir, NULL, NULL);
 408         }
 409         if (match_subsystem(udev_enumerate, "drivers")) {
 410                 info(udev, "searching '%s/*/drivers/*' dir\n", subsysdir);
 411                 scan_dir(udev_enumerate, subsysdir, "drivers", "drivers");
 412         }
 413         return 0;
 414 }