2 * Copyright (C) 2003-2008 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_device *dev, const char *name, int add)
37 struct udev *udev = udev_device_get_udev(dev);
38 char name_enc[UTIL_PATH_SIZE];
39 char filename[UTIL_PATH_SIZE * 2];
41 util_path_encode(&name[strlen(udev_get_dev_path(udev))+1], name_enc, sizeof(name_enc));
42 snprintf(filename, sizeof(filename), "%s/.udev/names/%s/%u:%u", udev_get_dev_path(udev), name_enc,
43 major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)));
46 dbg(udev, "creating index: '%s'\n", filename);
47 util_create_path(udev, filename);
48 symlink(udev_device_get_devpath(dev), filename);
50 dbg(udev, "removing index: '%s'\n", filename);
52 util_delete_path(udev, filename);
57 int udev_node_mknod(struct udev_device *dev, const char *file, dev_t devnum, mode_t mode, uid_t uid, gid_t gid)
59 struct udev *udev = udev_device_get_udev(dev);
64 if (major(devnum) == 0)
65 devnum = udev_device_get_devnum(dev);
67 if (strcmp(udev_device_get_subsystem(dev), "block") == 0)
73 file = udev_device_get_devnode(dev);
75 if (lstat(file, &stats) == 0) {
76 if (((stats.st_mode & S_IFMT) == (mode & S_IFMT)) && (stats.st_rdev == devnum)) {
77 info(udev, "preserve file '%s', because it has correct dev_t\n", file);
79 udev_selinux_lsetfilecon(udev, file, mode);
81 char file_tmp[UTIL_PATH_SIZE + sizeof(TMP_FILE_EXT)];
83 info(udev, "atomically replace existing file '%s'\n", file);
84 util_strscpyl(file_tmp, sizeof(file_tmp), file, TMP_FILE_EXT, NULL);
86 udev_selinux_setfscreatecon(udev, file_tmp, mode);
87 err = mknod(file_tmp, mode, devnum);
88 udev_selinux_resetfscreatecon(udev);
90 err(udev, "mknod(%s, %#o, %u, %u) failed: %m\n",
91 file_tmp, mode, major(devnum), minor(devnum));
94 err = rename(file_tmp, file);
96 err(udev, "rename(%s, %s) failed: %m\n", file_tmp, file);
101 info(udev, "mknod(%s, %#o, (%u,%u))\n", file, mode, major(devnum), minor(devnum));
102 udev_selinux_setfscreatecon(udev, file, mode);
103 err = mknod(file, mode, devnum);
104 udev_selinux_resetfscreatecon(udev);
106 err(udev, "mknod(%s, %#o, (%u,%u) failed: %m\n", file, mode, major(devnum), minor(devnum));
111 if (!preserve || stats.st_mode != mode) {
112 info(udev, "chmod(%s, %#o)\n", file, mode);
113 err = chmod(file, mode);
115 err(udev, "chmod(%s, %#o) failed: %m\n", file, mode);
120 if (!preserve || stats.st_uid != uid || stats.st_gid != gid) {
121 info(udev, "chown(%s, %u, %u)\n", file, uid, gid);
122 err = chown(file, uid, gid);
124 err(udev, "chown(%s, %u, %u) failed: %m\n", file, uid, gid);
132 static int node_symlink(struct udev *udev, const char *node, const char *slink)
135 char target[UTIL_PATH_SIZE];
138 char slink_tmp[UTIL_PATH_SIZE + sizeof(TMP_FILE_EXT)];
143 /* use relative link */
145 while (node[i] && (node[i] == slink[i])) {
152 while (slink[i] != '\0') {
154 l = util_strpcpy(&s, l, "../");
157 l = util_strscpy(s, l, &node[tail]);
163 /* preserve link with correct target, do not replace node of other device */
164 if (lstat(slink, &stats) == 0) {
165 if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
168 info(udev, "found existing node instead of symlink '%s'\n", slink);
169 if (lstat(node, &stats2) == 0) {
170 if ((stats.st_mode & S_IFMT) == (stats2.st_mode & S_IFMT) &&
171 stats.st_rdev == stats2.st_rdev) {
172 info(udev, "replace device node '%s' with symlink to our node '%s'\n",
175 err(udev, "device node '%s' already exists, "
176 "link to '%s' will not overwrite it\n",
181 } else if (S_ISLNK(stats.st_mode)) {
182 char buf[UTIL_PATH_SIZE];
185 dbg(udev, "found existing symlink '%s'\n", slink);
186 len = readlink(slink, buf, sizeof(buf));
189 if (strcmp(target, buf) == 0) {
190 info(udev, "preserve already existing symlink '%s' to '%s'\n",
192 udev_selinux_lsetfilecon(udev, slink, S_IFLNK);
198 info(udev, "creating symlink '%s' to '%s'\n", slink, target);
199 udev_selinux_setfscreatecon(udev, slink, S_IFLNK);
200 err = symlink(target, slink);
201 udev_selinux_resetfscreatecon(udev);
206 info(udev, "atomically replace '%s'\n", slink);
207 util_strscpyl(slink_tmp, sizeof(slink_tmp), slink, TMP_FILE_EXT, NULL);
209 udev_selinux_setfscreatecon(udev, slink, S_IFLNK);
210 err = symlink(target, slink_tmp);
211 udev_selinux_resetfscreatecon(udev);
213 err(udev, "symlink(%s, %s) failed: %m\n", target, slink_tmp);
216 err = rename(slink_tmp, slink);
218 err(udev, "rename(%s, %s) failed: %m\n", slink_tmp, slink);
225 static int name_index_get_devices(struct udev *udev, const char *name, struct udev_list_node *dev_list)
227 char dirname[UTIL_PATH_SIZE];
234 l = util_strpcpyl(&s, sizeof(dirname), udev_get_dev_path(udev),
235 "/.udev/names/", NULL);
236 util_path_encode(&name[strlen(udev_get_dev_path(udev))+1], s, l);
237 dir = opendir(dirname);
239 dbg(udev, "no index directory '%s': %m\n", dirname);
243 dbg(udev, "found index directory '%s'\n", dirname);
247 char devpath[UTIL_PATH_SIZE];
248 char syspath[UTIL_PATH_SIZE];
252 if (dent == NULL || dent->d_name[0] == '\0')
254 if (dent->d_name[0] == '.')
257 len = readlinkat(dirfd(dir), dent->d_name, devpath, sizeof(devpath));
258 if (len < 0 || (size_t)len >= sizeof(devpath))
261 util_strscpyl(syspath, sizeof(syspath), udev_get_sys_path(udev), devpath, NULL);
262 udev_list_entry_add(udev, dev_list, syspath, NULL, 1, 0);
270 static int update_link(struct udev_device *dev, const char *slink)
272 struct udev *udev = udev_device_get_udev(dev);
273 struct udev_list_node dev_list;
274 struct udev_list_entry *dev_entry;
275 char target[UTIL_PATH_SIZE];
280 dbg(udev, "update symlink '%s' of '%s'\n", slink, udev_device_get_syspath(dev));
282 udev_list_init(&dev_list);
283 count = name_index_get_devices(udev, slink, &dev_list);
285 info(udev, "found %i devices with name '%s'\n", count, slink);
287 /* if we don't have a reference, delete it */
289 info(udev, "no reference left, remove '%s'\n", slink);
291 util_delete_path(udev, slink);
295 /* find the device with the highest priority */
297 udev_list_entry_foreach(dev_entry, udev_list_get_entry(&dev_list)) {
299 struct udev_device *dev_db;
302 syspath = udev_list_entry_get_name(dev_entry);
303 dbg(udev, "found '%s' for '%s'\n", syspath, slink);
305 /* did we find ourself? we win, if we have the same priority */
306 if (strcmp(udev_device_get_syspath(dev), syspath) == 0) {
307 dbg(udev, "compare (our own) priority of '%s' %i >= %i\n",
308 udev_device_get_devpath(dev), udev_device_get_devlink_priority(dev), priority);
309 if (strcmp(udev_device_get_devnode(dev), slink) == 0) {
310 info(udev, "'%s' is our device node, database inconsistent, skip link update\n",
311 udev_device_get_devnode(dev));
312 } else if (target[0] == '\0' || udev_device_get_devlink_priority(dev) >= priority) {
313 priority = udev_device_get_devlink_priority(dev);
314 util_strscpy(target, sizeof(target), udev_device_get_devnode(dev));
319 /* another device, read priority from database */
320 dev_db = udev_device_new_from_syspath(udev, syspath);
323 devnode = udev_device_get_devnode(dev_db);
324 if (devnode != NULL) {
325 if (strcmp(devnode, slink) == 0) {
326 info(udev, "'%s' is a device node of '%s', skip link update\n",
329 dbg(udev, "compare priority of '%s' %i > %i\n",
330 udev_device_get_devpath(dev_db),
331 udev_device_get_devlink_priority(dev_db),
333 if (target[0] == '\0' || udev_device_get_devlink_priority(dev_db) > priority) {
334 priority = udev_device_get_devlink_priority(dev_db);
335 util_strscpy(target, sizeof(target), devnode);
339 udev_device_unref(dev_db);
341 udev_list_cleanup_entries(udev, &dev_list);
343 if (target[0] == '\0') {
344 info(udev, "no current target for '%s' found\n", slink);
349 /* create symlink to the target with the highest priority */
350 info(udev, "'%s' with target '%s' has the highest priority %i, create it\n", slink, target, priority);
351 util_create_path(udev, slink);
352 node_symlink(udev, target, slink);
357 void udev_node_update_old_links(struct udev_device *dev, struct udev_device *dev_old)
359 struct udev *udev = udev_device_get_udev(dev);
360 struct udev_list_entry *list_entry;
361 const char *devnode_old;
363 /* update possible left-over symlinks */
364 udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev_old)) {
365 const char *name = udev_list_entry_get_name(list_entry);
366 struct udev_list_entry *list_entry_current;
369 /* check if old link name is now our node name */
370 if (strcmp(name, udev_device_get_devnode(dev)) == 0)
373 /* check if old link name still belongs to this device */
375 udev_list_entry_foreach(list_entry_current, udev_device_get_devlinks_list_entry(dev)) {
376 const char *name_current = udev_list_entry_get_name(list_entry_current);
378 if (strcmp(name, name_current) == 0) {
386 info(udev, "update old name, '%s' no longer belonging to '%s'\n",
387 name, udev_device_get_devpath(dev));
388 name_index(dev, name, 0);
389 update_link(dev, name);
393 * if the node name has changed, delete the node,
394 * and possibly restore a symlink of a different device
396 devnode_old = udev_device_get_devnode(dev_old);
397 if (devnode_old != NULL) {
398 const char *devnode = udev_device_get_devnode(dev);
400 if (devnode != NULL && strcmp(devnode_old, devnode) != 0) {
401 info(udev, "node has changed from '%s' to '%s'\n", devnode_old, devnode);
402 name_index(dev, devnode_old, 0);
403 update_link(dev, devnode_old);
408 int udev_node_add(struct udev_device *dev, mode_t mode, uid_t uid, gid_t gid)
410 struct udev *udev = udev_device_get_udev(dev);
413 struct udev_list_entry *list_entry;
416 info(udev, "creating device node '%s', devnum=%d:%d, mode=%#o, uid=%d, gid=%d\n",
417 udev_device_get_devnode(dev),
418 major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)),
421 util_create_path(udev, udev_device_get_devnode(dev));
422 if (udev_node_mknod(dev, NULL, makedev(0,0), mode, uid, gid) != 0) {
427 /* create all_partitions if requested */
428 num = udev_device_get_num_fake_partitions(dev);
430 info(udev, "creating device partition nodes '%s[1-%i]'\n", udev_device_get_devnode(dev), num);
431 for (i = 1; i <= num; i++) {
432 char partitionname[UTIL_PATH_SIZE];
435 snprintf(partitionname, sizeof(partitionname), "%s%d",
436 udev_device_get_devnode(dev), i);
437 partitionname[sizeof(partitionname)-1] = '\0';
438 part_devnum = makedev(major(udev_device_get_devnum(dev)),
439 minor(udev_device_get_devnum(dev)) + i);
440 udev_node_mknod(dev, partitionname, part_devnum, mode, uid, gid);
444 /* add node to name index */
445 name_index(dev, udev_device_get_devnode(dev), 1);
447 /* create/update symlinks, add symlinks to name index */
448 udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev)) {
449 name_index(dev, udev_list_entry_get_name(list_entry), 1);
450 update_link(dev, udev_list_entry_get_name(list_entry));
456 int udev_node_remove(struct udev_device *dev)
458 struct udev *udev = udev_device_get_udev(dev);
459 struct udev_list_entry *list_entry;
461 char partitionname[UTIL_PATH_SIZE];
466 /* remove node from name index */
467 name_index(dev, udev_device_get_devnode(dev), 0);
469 /* remove,update symlinks, remove symlinks from name index */
470 udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev)) {
471 name_index(dev, udev_list_entry_get_name(list_entry), 0);
472 update_link(dev, udev_list_entry_get_name(list_entry));
475 devnode = udev_device_get_devnode(dev);
478 if (stat(devnode, &stats) != 0) {
479 info(udev, "device node '%s' not found\n", devnode);
482 if (stats.st_rdev != udev_device_get_devnum(dev)) {
483 info(udev, "device node '%s' points to a different device, skip removal\n", devnode);
487 info(udev, "removing device node '%s'\n", devnode);
488 err = util_unlink_secure(udev, devnode);
492 num = udev_device_get_num_fake_partitions(dev);
496 info(udev, "removing all_partitions '%s[1-%i]'\n", devnode, num);
499 for (i = 1; i <= num; i++) {
500 snprintf(partitionname, sizeof(partitionname), "%s%d", devnode, i);
501 partitionname[sizeof(partitionname)-1] = '\0';
502 util_unlink_secure(udev, partitionname);
505 util_delete_path(udev, devnode);