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 attr_match_list;
  39         struct udev_list_node attr_nomatch_list;
  40         struct udev_list_node subsystem_match_list;
  41         struct udev_list_node subsystem_nomatch_list;
  42         struct udev_list_node devices_list;
  43         int devices_sorted;
  44 };
  45
  46 /**
  47  * udev_enumerate_new:
  48  * @udev: udev library context
  49  *
  50  * Returns: an enumeration context
  51  **/
  52 struct udev_enumerate *udev_enumerate_new(struct udev *udev)
  53 {
  54         struct udev_enumerate *udev_enumerate;
  55
  56         udev_enumerate = malloc(sizeof(struct udev_enumerate));
  57         if (udev_enumerate == NULL)
  58                 return NULL;
  59         memset(udev_enumerate, 0x00, (sizeof(struct udev_enumerate)));
  60         udev_enumerate->refcount = 1;
  61         udev_enumerate->udev = udev;
  62         udev_list_init(&udev_enumerate->devices_list);
  63         udev_list_init(&udev_enumerate->attr_match_list);
  64         udev_list_init(&udev_enumerate->attr_nomatch_list);
  65         udev_list_init(&udev_enumerate->subsystem_match_list);
  66         udev_list_init(&udev_enumerate->subsystem_nomatch_list);
  67         return udev_enumerate;
  68 }
  69
  70 struct udev_enumerate *udev_enumerate_ref(struct udev_enumerate *udev_enumerate)
  71 {
  72         if (udev_enumerate == NULL)
  73                 return NULL;
  74         udev_enumerate->refcount++;
  75         return udev_enumerate;
  76 }
  77
  78 void udev_enumerate_unref(struct udev_enumerate *udev_enumerate)
  79 {
  80         if (udev_enumerate == NULL)
  81                 return;
  82         udev_enumerate->refcount--;
  83         if (udev_enumerate->refcount > 0)
  84                 return;
  85         udev_list_cleanup(udev_enumerate->udev, &udev_enumerate->devices_list);
  86         udev_list_cleanup(udev_enumerate->udev, &udev_enumerate->attr_match_list);
  87         udev_list_cleanup(udev_enumerate->udev, &udev_enumerate->attr_nomatch_list);
  88         udev_list_cleanup(udev_enumerate->udev, &udev_enumerate->subsystem_match_list);
  89         udev_list_cleanup(udev_enumerate->udev, &udev_enumerate->subsystem_nomatch_list);
  90         free(udev_enumerate);
  91 }
  92
  93 struct udev *udev_enumerate_get_udev(struct udev_enumerate *udev_enumerate)
  94 {
  95         if (udev_enumerate == NULL)
  96                 return NULL;
  97         return udev_enumerate->udev;
  98 }
  99
 100 struct udev_list_entry *udev_enumerate_get_list_entry(struct udev_enumerate *udev_enumerate)
 101 {
 102         if (udev_enumerate == NULL)
 103                 return NULL;
 104         if (!udev_enumerate->devices_sorted)
 105                 devices_sort(udev_enumerate);
 106         return udev_list_get_entry(&udev_enumerate->devices_list);
 107 }
 108
 109 int udev_enumerate_add_match_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
 110 {
 111         if (udev_enumerate == NULL)
 112                 return -EINVAL;
 113         if (subsystem == NULL)
 114                 return 0;
 115         if (udev_list_entry_add(udev_enumerate_get_udev(udev_enumerate),
 116                                 &udev_enumerate->subsystem_match_list, subsystem, NULL, 1, 0) == NULL)
 117                 return -ENOMEM;
 118         return 0;
 119 }
 120
 121 int udev_enumerate_add_nomatch_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
 122 {
 123         if (udev_enumerate == NULL)
 124                 return -EINVAL;
 125         if (subsystem == NULL)
 126                 return 0;
 127         if (udev_list_entry_add(udev_enumerate_get_udev(udev_enumerate),
 128                                 &udev_enumerate->subsystem_nomatch_list, subsystem, NULL, 1, 0) == NULL)
 129                 return -ENOMEM;
 130         return 0;
 131 }
 132
 133 int udev_enumerate_add_match_attr(struct udev_enumerate *udev_enumerate, const char *attr, const char *value)
 134 {
 135         if (udev_enumerate == NULL)
 136                 return -EINVAL;
 137         if (attr == NULL)
 138                 return 0;
 139         if (udev_list_entry_add(udev_enumerate_get_udev(udev_enumerate),
 140                            &udev_enumerate->attr_match_list, attr, value, 1, 0) == NULL)
 141                 return -ENOMEM;
 142         return 0;
 143 }
 144
 145 int udev_enumerate_add_nomatch_attr(struct udev_enumerate *udev_enumerate, const char *attr, const char *value)
 146 {
 147         if (udev_enumerate == NULL)
 148                 return -EINVAL;
 149         if (attr == NULL)
 150                 return 0;
 151         if (udev_list_entry_add(udev_enumerate_get_udev(udev_enumerate),
 152                            &udev_enumerate->attr_nomatch_list, attr, value, 1, 0) == NULL)
 153                 return -ENOMEM;
 154         return 0;
 155 }
 156
 157 static int match_attr_value(struct udev *udev, const char *syspath, const char *attr, const char *match_val)
 158 {
 159         struct udev_device *device;
 160         const char *val = NULL;
 161         int match = 0;
 162
 163         device = udev_device_new_from_syspath(udev, syspath);
 164         if (device == NULL)
 165                 return -EINVAL;
 166         val = udev_device_get_attr_value(device, attr);
 167         if (val == NULL)
 168                 goto exit;
 169         if (match_val == NULL) {
 170                 match = 1;
 171                 goto exit;
 172         }
 173         if (fnmatch(match_val, val, 0) == 0) {
 174                 match = 1;
 175                 goto exit;
 176         }
 177 exit:
 178         udev_device_unref(device);
 179         return match;
 180 }
 181
 182 static int match_attr(struct udev_enumerate *udev_enumerate, const char *syspath)
 183 {
 184         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 185         struct udev_list_entry *list_entry;
 186
 187         /* skip list */
 188         udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->attr_nomatch_list)) {
 189                 if (match_attr_value(udev, syspath,
 190                                      udev_list_entry_get_name(list_entry),
 191                                      udev_list_entry_get_value(list_entry)))
 192                         return 0;
 193         }
 194         /* include list */
 195         if (udev_list_get_entry(&udev_enumerate->attr_match_list) != NULL) {
 196                 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->attr_match_list)) {
 197                         /* anything that does not match, will make it FALSE */
 198                         if (!match_attr_value(udev, syspath,
 199                                               udev_list_entry_get_name(list_entry),
 200                                               udev_list_entry_get_value(list_entry)))
 201                                 return 0;
 202                 }
 203                 return 1;
 204         }
 205         return 1;
 206 }
 207
 208 static int scan_dir_and_add_devices(struct udev_enumerate *udev_enumerate,
 209                                     const char *basedir, const char *subdir1, const char *subdir2)
 210 {
 211         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 212         char path[UTIL_PATH_SIZE];
 213         DIR *dir;
 214         struct dirent *dent;
 215
 216         util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
 217         util_strlcat(path, "/", sizeof(path));
 218         util_strlcat(path, basedir, sizeof(path));
 219         if (subdir1 != NULL) {
 220                 util_strlcat(path, "/", sizeof(path));
 221                 util_strlcat(path, subdir1, sizeof(path));
 222         }
 223         if (subdir2 != NULL) {
 224                 util_strlcat(path, "/", sizeof(path));
 225                 util_strlcat(path, subdir2, sizeof(path));
 226         }
 227         dir = opendir(path);
 228         if (dir == NULL)
 229                 return -1;
 230         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 231                 char syspath[UTIL_PATH_SIZE];
 232                 char filename[UTIL_PATH_SIZE];
 233                 struct stat statbuf;
 234
 235                 if (dent->d_name[0] == '.')
 236                         continue;
 237                 util_strlcpy(syspath, path, sizeof(syspath));
 238                 util_strlcat(syspath, "/", sizeof(syspath));
 239                 util_strlcat(syspath, dent->d_name, sizeof(syspath));
 240                 if (lstat(syspath, &statbuf) != 0)
 241                         continue;
 242                 if (S_ISREG(statbuf.st_mode))
 243                         continue;
 244                 if (S_ISLNK(statbuf.st_mode))
 245                         util_resolve_sys_link(udev, syspath, sizeof(syspath));
 246                 util_strlcpy(filename, syspath, sizeof(filename));
 247                 util_strlcat(filename, "/uevent", sizeof(filename));
 248                 if (stat(filename, &statbuf) != 0)
 249                         continue;
 250                 if (!match_attr(udev_enumerate, syspath))
 251                         continue;
 252                 udev_list_entry_add(udev, &udev_enumerate->devices_list, syspath, NULL, 1, 1);
 253         }
 254         closedir(dir);
 255         return 0;
 256 }
 257
 258 static int match_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
 259 {
 260         struct udev_list_entry *list_entry;
 261
 262         udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_nomatch_list)) {
 263                 if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
 264                         return 0;
 265         }
 266         if (udev_list_get_entry(&udev_enumerate->subsystem_match_list) != NULL) {
 267                 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_match_list)) {
 268                         if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
 269                                 return 1;
 270                 }
 271                 return 0;
 272         }
 273         return 1;
 274 }
 275
 276 static int scan_dir(struct udev_enumerate *udev_enumerate, const char *basedir, const char *subdir, const char *subsystem)
 277 {
 278         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 279
 280         char path[UTIL_PATH_SIZE];
 281         DIR *dir;
 282         struct dirent *dent;
 283
 284         util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
 285         util_strlcat(path, "/", sizeof(path));
 286         util_strlcat(path, basedir, sizeof(path));
 287         dir = opendir(path);
 288         if (dir == NULL)
 289                 return -1;
 290         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 291                 if (dent->d_name[0] == '.')
 292                         continue;
 293                 if (!match_subsystem(udev_enumerate, subsystem != NULL ? subsystem : dent->d_name))
 294                         continue;
 295                 scan_dir_and_add_devices(udev_enumerate, basedir, dent->d_name, subdir);
 296         }
 297         closedir(dir);
 298         return 0;
 299 }
 300
 301 static int devices_delay(struct udev *udev, const char *syspath)
 302 {
 303         static const char *delay_device_list[] = {
 304                 "/block/md",
 305                 "/block/dm-",
 306                 NULL
 307         };
 308         size_t len;
 309         int i;
 310
 311         len = strlen(udev_get_sys_path(udev));
 312         for (i = 0; delay_device_list[i] != NULL; i++) {
 313                 if (strstr(&syspath[len], delay_device_list[i]) != NULL) {
 314                         info(udev, "delaying: %s\n", syspath);
 315                         return 1;
 316                 }
 317         }
 318         return 0;
 319 }
 320
 321 /* sort delayed devices to the end of the list */
 322 static int devices_sort(struct udev_enumerate *udev_enumerate)
 323 {
 324         struct udev_list_entry *list_entry;
 325
 326         udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->devices_list)) {
 327                 if (devices_delay(udev_enumerate->udev, udev_list_entry_get_name(list_entry)))
 328                         udev_list_entry_move_to_end(list_entry);
 329         }
 330         udev_enumerate->devices_sorted = 1;
 331         return 0;
 332 }
 333
 334 int udev_enumerate_add_syspath(struct udev_enumerate *udev_enumerate, const char *syspath)
 335 {
 336         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 337         struct udev_device *udev_device;
 338
 339         if (udev_enumerate == NULL)
 340                 return -EINVAL;
 341         if (syspath == NULL)
 342                 return 0;
 343         /* resolve to real syspath */
 344         udev_device = udev_device_new_from_syspath(udev_enumerate->udev, syspath);
 345         if (udev_device == NULL)
 346                 return -EINVAL;
 347         udev_list_entry_add(udev, &udev_enumerate->devices_list,
 348                             udev_device_get_syspath(udev_device), NULL, 1, 1);
 349         udev_device_unref(udev_device);
 350         return 0;
 351 }
 352
 353 /**
 354  * udev_enumerate_scan_devices:
 355  * @udev_enumerate: udev enumeration context
 356  *
 357  * Returns: a negative value on error.
 358  **/
 359 int udev_enumerate_scan_devices(struct udev_enumerate *udev_enumerate)
 360 {
 361         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 362         char base[UTIL_PATH_SIZE];
 363         struct stat statbuf;
 364         struct udev_list_entry *list_entry;
 365
 366         if (udev_enumerate == NULL)
 367                 return -EINVAL;
 368         util_strlcpy(base, udev_get_sys_path(udev), sizeof(base));
 369         util_strlcat(base, "/subsystem", sizeof(base));
 370         if (stat(base, &statbuf) == 0) {
 371                 /* we have /subsystem/, forget all the old stuff */
 372                 info(udev, "searching '/subsystem/*/devices/*' dir\n");
 373                 scan_dir(udev_enumerate, "subsystem", "devices", NULL);
 374         } else {
 375                 info(udev, "searching '/bus/*/devices/*' dir\n");
 376                 scan_dir(udev_enumerate, "bus", "devices", NULL);
 377                 info(udev, "searching '/class/*' dir\n");
 378                 scan_dir(udev_enumerate, "class", NULL, NULL);
 379                 /* if block isn't a class, scan /block/ */
 380                 util_strlcpy(base, udev_get_sys_path(udev), sizeof(base));
 381                 util_strlcat(base, "/class/block", sizeof(base));
 382                 if (stat(base, &statbuf) != 0) {
 383                         if (match_subsystem(udev_enumerate, "block")) {
 384                                 info(udev, "searching '/block/*' dir\n");
 385                                 /* scan disks */
 386                                 scan_dir_and_add_devices(udev_enumerate, "block", NULL, NULL);
 387                                 /* scan partitions */
 388                                 info(udev, "searching '/block/*/*' dir\n");
 389                                 scan_dir(udev_enumerate, "block", NULL, "block");
 390                         }
 391                 }
 392         }
 393         /* sort delayed devices to the end of the list */
 394         udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->devices_list)) {
 395                 if (devices_delay(udev, udev_list_entry_get_name(list_entry)))
 396                         udev_list_entry_move_to_end(list_entry);
 397         }
 398         return 0;
 399 }
 400
 401 /**
 402  * udev_enumerate_scan_subsystems:
 403  * @udev_enumerate: udev enumeration context
 404  *
 405  * Returns: a negative value on error.
 406  **/
 407 int udev_enumerate_scan_subsystems(struct udev_enumerate *udev_enumerate)
 408 {
 409         struct udev *udev = udev_enumerate_get_udev(udev_enumerate);
 410         char base[UTIL_PATH_SIZE];
 411         struct stat statbuf;
 412         const char *subsysdir;
 413
 414         if (udev_enumerate == NULL)
 415                 return -EINVAL;
 416         util_strlcpy(base, udev_get_sys_path(udev), sizeof(base));
 417         util_strlcat(base, "/subsystem", sizeof(base));
 418         if (stat(base, &statbuf) == 0)
 419                 subsysdir = "subsystem";
 420         else
 421                 subsysdir = "bus";
 422         if (match_subsystem(udev_enumerate, "subsystem")) {
 423                 info(udev, "searching '%s/*' dir\n", subsysdir);
 424                 scan_dir_and_add_devices(udev_enumerate, subsysdir, NULL, NULL);
 425         }
 426         if (match_subsystem(udev_enumerate, "drivers")) {
 427                 info(udev, "searching '%s/*/drivers/*' dir\n", subsysdir);
 428                 scan_dir(udev_enumerate, subsysdir, "drivers", "drivers");
 429         }
 430         return 0;
 431 }