2 * Copyright (C) 2004-2008 Kay Sievers <kay.sievers@vrfy.org>
4 * This program is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
28 #include <sys/types.h>
32 #define TMP_FILE_EXT ".udev-tmp"
34 /* reverse mapping from the device file name to the devpath */
35 static int name_index(struct udev *udev, const char *devpath, const char *name, int add)
37 char device[UTIL_PATH_SIZE];
38 char filename[UTIL_PATH_SIZE * 2];
39 size_t devlen = strlen(udev_get_dev_path(udev))+1;
43 /* directory with device name */
44 util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
45 start = util_strlcat(filename, "/.udev/names/", sizeof(filename));
46 util_strlcat(filename, &name[devlen], sizeof(filename));
47 util_path_encode(&filename[start], sizeof(filename) - start);
48 /* entry with the devpath */
49 util_strlcpy(device, devpath, sizeof(device));
50 util_path_encode(device, sizeof(device));
51 util_strlcat(filename, "/", sizeof(filename));
52 util_strlcat(filename, device, sizeof(filename));
55 dbg(udev, "creating index: '%s'\n", filename);
56 util_create_path(udev, filename);
57 fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
61 dbg(udev, "removing index: '%s'\n", filename);
63 util_delete_path(udev, filename);
68 int udev_node_mknod(struct udev_device *dev, const char *file, dev_t devnum, mode_t mode, uid_t uid, gid_t gid)
70 struct udev *udev = udev_device_get_udev(dev);
75 if (major(devnum) == 0)
76 devnum = udev_device_get_devnum(dev);
78 if (strcmp(udev_device_get_subsystem(dev), "block") == 0)
84 file = udev_device_get_devnode(dev);
86 if (lstat(file, &stats) == 0) {
87 if (((stats.st_mode & S_IFMT) == (mode & S_IFMT)) && (stats.st_rdev == devnum)) {
88 info(udev, "preserve file '%s', because it has correct dev_t\n", file);
90 udev_selinux_lsetfilecon(udev, file, mode);
92 char file_tmp[UTIL_PATH_SIZE + sizeof(TMP_FILE_EXT)];
94 info(udev, "atomically replace existing file '%s'\n", file);
95 util_strlcpy(file_tmp, file, sizeof(file_tmp));
96 util_strlcat(file_tmp, TMP_FILE_EXT, sizeof(file_tmp));
98 udev_selinux_setfscreatecon(udev, file_tmp, mode);
99 err = mknod(file_tmp, mode, devnum);
100 udev_selinux_resetfscreatecon(udev);
102 err(udev, "mknod(%s, %#o, %u, %u) failed: %m\n",
103 file_tmp, mode, major(devnum), minor(devnum));
106 err = rename(file_tmp, file);
108 err(udev, "rename(%s, %s) failed: %m\n", file_tmp, file);
113 info(udev, "mknod(%s, %#o, (%u,%u))\n", file, mode, major(devnum), minor(devnum));
114 udev_selinux_setfscreatecon(udev, file, mode);
115 err = mknod(file, mode, devnum);
116 udev_selinux_resetfscreatecon(udev);
118 err(udev, "mknod(%s, %#o, (%u,%u) failed: %m\n", file, mode, major(devnum), minor(devnum));
123 if (!preserve || stats.st_mode != mode) {
124 info(udev, "chmod(%s, %#o)\n", file, mode);
125 err = chmod(file, mode);
127 err(udev, "chmod(%s, %#o) failed: %m\n", file, mode);
132 if (!preserve || stats.st_uid != uid || stats.st_gid != gid) {
133 info(udev, "chown(%s, %u, %u)\n", file, uid, gid);
134 err = chown(file, uid, gid);
136 err(udev, "chown(%s, %u, %u) failed: %m\n", file, uid, gid);
144 static int node_symlink(struct udev *udev, const char *node, const char *slink)
147 char target[UTIL_PATH_SIZE];
148 char slink_tmp[UTIL_PATH_SIZE + sizeof(TMP_FILE_EXT)];
154 /* use relative link */
156 while (node[i] && (node[i] == slink[i])) {
161 while (slink[i] != '\0') {
163 util_strlcat(target, "../", sizeof(target));
166 util_strlcat(target, &node[tail], sizeof(target));
168 /* preserve link with correct target, do not replace node of other device */
169 if (lstat(slink, &stats) == 0) {
170 if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
173 info(udev, "found existing node instead of symlink '%s'\n", slink);
174 if (lstat(node, &stats2) == 0) {
175 if ((stats.st_mode & S_IFMT) == (stats2.st_mode & S_IFMT) &&
176 stats.st_rdev == stats2.st_rdev) {
177 info(udev, "replace device node '%s' with symlink to our node '%s'\n",
180 err(udev, "device node '%s' already exists, "
181 "link to '%s' will not overwrite it\n",
186 } else if (S_ISLNK(stats.st_mode)) {
187 char buf[UTIL_PATH_SIZE];
189 dbg(udev, "found existing symlink '%s'\n", slink);
190 len = readlink(slink, buf, sizeof(buf));
193 if (strcmp(target, buf) == 0) {
194 info(udev, "preserve already existing symlink '%s' to '%s'\n",
196 udev_selinux_lsetfilecon(udev, slink, S_IFLNK);
202 info(udev, "creating symlink '%s' to '%s'\n", slink, target);
203 udev_selinux_setfscreatecon(udev, slink, S_IFLNK);
204 err = symlink(target, slink);
205 udev_selinux_resetfscreatecon(udev);
210 info(udev, "atomically replace '%s'\n", slink);
211 util_strlcpy(slink_tmp, slink, sizeof(slink_tmp));
212 util_strlcat(slink_tmp, TMP_FILE_EXT, sizeof(slink_tmp));
214 udev_selinux_setfscreatecon(udev, slink, S_IFLNK);
215 err = symlink(target, slink_tmp);
216 udev_selinux_resetfscreatecon(udev);
218 err(udev, "symlink(%s, %s) failed: %m\n", target, slink_tmp);
221 err = rename(slink_tmp, slink);
223 err(udev, "rename(%s, %s) failed: %m\n", slink_tmp, slink);
231 static int name_index_get_devices(struct udev *udev, const char *name, struct udev_list_node *dev_list)
233 char dirname[PATH_MAX];
234 size_t devlen = strlen(udev_get_dev_path(udev))+1;
239 util_strlcpy(dirname, udev_get_dev_path(udev), sizeof(dirname));
240 start = util_strlcat(dirname, "/.udev/names/", sizeof(dirname));
241 util_strlcat(dirname, &name[devlen], sizeof(dirname));
242 util_path_encode(&dirname[start], sizeof(dirname) - start);
243 dir = opendir(dirname);
245 dbg(udev, "no index directory '%s': %m\n", dirname);
249 dbg(udev, "found index directory '%s'\n", dirname);
253 char device[UTIL_PATH_SIZE];
256 if (ent == NULL || ent->d_name[0] == '\0')
258 if (ent->d_name[0] == '.')
261 util_strlcpy(device, udev_get_sys_path(udev), sizeof(device));
262 util_strlcat(device, ent->d_name, sizeof(device));
263 util_path_decode(device);
264 udev_list_entry_add(udev, dev_list, device, NULL, 1, 0);
272 static int update_link(struct udev_device *dev, const char *slink)
274 struct udev *udev = udev_device_get_udev(dev);
275 struct udev_list_node dev_list;
276 struct udev_list_entry *dev_entry;
277 char target[UTIL_PATH_SIZE];
282 dbg(udev, "update symlink '%s' of '%s'\n", slink, udev_device_get_syspath(dev));
284 udev_list_init(&dev_list);
285 count = name_index_get_devices(udev, slink, &dev_list);
287 info(udev, "found %i devices with name '%s'\n", count, slink);
289 /* if we don't have a reference, delete it */
291 info(udev, "no reference left, remove '%s'\n", slink);
293 util_delete_path(udev, slink);
297 /* find the device with the highest priority */
299 udev_list_entry_foreach(dev_entry, udev_list_get_entry(&dev_list)) {
301 struct udev_device *dev_db;
304 syspath = udev_list_entry_get_name(dev_entry);
305 dbg(udev, "found '%s' for '%s'\n", syspath, slink);
307 /* did we find ourself? we win, if we have the same priority */
308 if (strcmp(udev_device_get_syspath(dev), syspath) == 0) {
309 dbg(udev, "compare (our own) priority of '%s' %i >= %i\n",
310 udev_device_get_devpath(dev), udev_device_get_devlink_priority(dev), priority);
311 if (strcmp(udev_device_get_devnode(dev), slink) == 0) {
312 info(udev, "'%s' is our device node, database inconsistent, skip link update\n",
313 udev_device_get_devnode(dev));
314 } else if (target[0] == '\0' || udev_device_get_devlink_priority(dev) >= priority) {
315 priority = udev_device_get_devlink_priority(dev);
316 util_strlcpy(target, udev_device_get_devnode(dev), sizeof(target));
321 /* another device, read priority from database */
322 dev_db = udev_device_new_from_syspath(udev, syspath);
325 devnode = udev_device_get_devnode(dev_db);
326 if (devnode != NULL) {
327 if (strcmp(devnode, slink) == 0) {
328 info(udev, "'%s' is a device node of '%s', skip link update\n",
331 dbg(udev, "compare priority of '%s' %i > %i\n",
332 udev_device_get_devpath(dev_db),
333 udev_device_get_devlink_priority(dev_db),
335 if (target[0] == '\0' || udev_device_get_devlink_priority(dev_db) > priority) {
336 priority = udev_device_get_devlink_priority(dev_db);
337 util_strlcpy(target, devnode, sizeof(target));
341 udev_device_unref(dev_db);
343 udev_list_cleanup_entries(udev, &dev_list);
345 if (target[0] == '\0') {
346 info(udev, "no current target for '%s' found\n", slink);
351 /* create symlink to the target with the highest priority */
352 info(udev, "'%s' with target '%s' has the highest priority %i, create it\n", slink, target, priority);
353 util_create_path(udev, slink);
354 node_symlink(udev, target, slink);
359 void udev_node_update_old_links(struct udev_device *dev, struct udev_device *dev_old)
361 struct udev *udev = udev_device_get_udev(dev);
362 struct udev_list_entry *list_entry;
363 const char *devnode_old;
365 /* update possible left-over symlinks */
366 udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev_old)) {
367 const char *name = udev_list_entry_get_name(list_entry);
368 struct udev_list_entry *list_entry_current;
371 /* check if old link name is now our node name */
372 if (strcmp(name, udev_device_get_devnode(dev)) == 0)
375 /* check if old link name still belongs to this device */
377 udev_list_entry_foreach(list_entry_current, udev_device_get_devlinks_list_entry(dev)) {
378 const char *name_current = udev_list_entry_get_name(list_entry_current);
380 if (strcmp(name, name_current) == 0) {
388 info(udev, "update old name, '%s' no longer belonging to '%s'\n",
389 name, udev_device_get_devpath(dev));
390 name_index(udev, udev_device_get_devpath(dev), name, 0);
391 update_link(dev, name);
395 * if the node name has changed, delete the node,
396 * and possibly restore a symlink of a different device
398 devnode_old = udev_device_get_devnode(dev_old);
399 if (devnode_old != NULL) {
400 const char *devnode = udev_device_get_devnode(dev);
402 if (devnode != NULL && strcmp(devnode_old, devnode) != 0) {
403 info(udev, "node has changed from '%s' to '%s'\n", devnode_old, devnode);
404 name_index(udev, udev_device_get_devpath(dev), devnode_old, 0);
405 update_link(dev, devnode_old);
410 int udev_node_add(struct udev_device *dev, mode_t mode, uid_t uid, gid_t gid)
412 struct udev *udev = udev_device_get_udev(dev);
415 struct udev_list_entry *list_entry;
418 info(udev, "creating device node '%s', devnum=%d:%d, mode=%#o, uid=%d, gid=%d\n",
419 udev_device_get_devnode(dev),
420 major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)),
423 util_create_path(udev, udev_device_get_devnode(dev));
424 if (udev_node_mknod(dev, NULL, makedev(0,0), mode, uid, gid) != 0) {
429 /* create all_partitions if requested */
430 num = udev_device_get_num_fake_partitions(dev);
432 info(udev, "creating device partition nodes '%s[1-%i]'\n", udev_device_get_devnode(dev), num);
433 for (i = 1; i <= num; i++) {
434 char partitionname[UTIL_PATH_SIZE];
437 snprintf(partitionname, sizeof(partitionname), "%s%d",
438 udev_device_get_devnode(dev), i);
439 partitionname[sizeof(partitionname)-1] = '\0';
440 part_devnum = makedev(major(udev_device_get_devnum(dev)),
441 minor(udev_device_get_devnum(dev)) + i);
442 udev_node_mknod(dev, partitionname, part_devnum, mode, uid, gid);
446 /* add node to name index */
447 name_index(udev, udev_device_get_devpath(dev), udev_device_get_devnode(dev), 1);
449 /* create/update symlinks, add symlinks to name index */
450 udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev)) {
451 name_index(udev, udev_device_get_devpath(dev), udev_list_entry_get_name(list_entry), 1);
452 update_link(dev, udev_list_entry_get_name(list_entry));
458 int udev_node_remove(struct udev_device *dev)
460 struct udev *udev = udev_device_get_udev(dev);
461 struct udev_list_entry *list_entry;
463 char partitionname[UTIL_PATH_SIZE];
468 /* remove node from name index */
469 name_index(udev, udev_device_get_devpath(dev), udev_device_get_devnode(dev), 0);
471 /* remove,update symlinks, remove symlinks from name index */
472 udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev)) {
473 name_index(udev, udev_device_get_devpath(dev), udev_list_entry_get_name(list_entry), 0);
474 update_link(dev, udev_list_entry_get_name(list_entry));
477 devnode = udev_device_get_devnode(dev);
480 if (stat(devnode, &stats) != 0) {
481 info(udev, "device node '%s' not found\n", devnode);
484 if (stats.st_rdev != udev_device_get_devnum(dev)) {
485 info(udev, "device node '%s' points to a different device, skip removal\n", devnode);
489 info(udev, "removing device node '%s'\n", devnode);
490 err = util_unlink_secure(udev, devnode);
494 num = udev_device_get_num_fake_partitions(dev);
498 info(udev, "removing all_partitions '%s[1-%i]'\n", devnode, num);
501 for (i = 1; i <= num; i++) {
502 snprintf(partitionname, sizeof(partitionname), "%s%d", devnode, i);
503 partitionname[sizeof(partitionname)-1] = '\0';
504 util_unlink_secure(udev, partitionname);
507 util_delete_path(udev, devnode);