2 * Copyright (C) 2003-2010 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/>.
30 #include <sys/types.h>
34 #define TMP_FILE_EXT ".udev-tmp"
36 int udev_node_mknod(struct udev_device *dev, const char *file, dev_t devnum, mode_t mode, uid_t uid, gid_t gid)
38 struct udev *udev = udev_device_get_udev(dev);
42 if (major(devnum) == 0)
43 devnum = udev_device_get_devnum(dev);
45 if (strcmp(udev_device_get_subsystem(dev), "block") == 0)
51 file = udev_device_get_devnode(dev);
53 if (lstat(file, &stats) == 0) {
54 if (((stats.st_mode & S_IFMT) == (mode & S_IFMT)) && (stats.st_rdev == devnum)) {
55 info(udev, "preserve file '%s', because it has correct dev_t\n", file);
56 if (stats.st_mode != mode || stats.st_uid != uid || stats.st_gid != gid) {
57 info(udev, "set permissions %s, %#o, uid=%u, gid=%u\n", file, mode, uid, gid);
59 chown(file, uid, gid);
60 udev_selinux_lsetfilecon(udev, file, mode);
62 info(udev, "preserve permissions %s, %#o, uid=%u, gid=%u\n", file, mode, uid, gid);
64 /* always update timestamp when we re-use the node, like on media change events */
65 utimensat(AT_FDCWD, file, NULL, 0);
67 char file_tmp[UTIL_PATH_SIZE + sizeof(TMP_FILE_EXT)];
69 info(udev, "atomically replace existing file '%s'\n", file);
70 util_strscpyl(file_tmp, sizeof(file_tmp), file, TMP_FILE_EXT, NULL);
72 udev_selinux_setfscreatecon(udev, file_tmp, mode);
73 err = mknod(file_tmp, mode, devnum);
74 udev_selinux_resetfscreatecon(udev);
76 err(udev, "mknod(%s, %#o, %u, %u) failed: %m\n",
77 file_tmp, mode, major(devnum), minor(devnum));
80 err = rename(file_tmp, file);
82 err(udev, "rename(%s, %s) failed: %m\n", file_tmp, file);
86 info(udev, "set permissions %s, %#o, uid=%u, gid=%u\n", file, mode, uid, gid);
88 chown(file, uid, gid);
91 info(udev, "mknod(%s, %#o, (%u,%u))\n", file, mode, major(devnum), minor(devnum));
93 err = util_create_path(udev, file);
94 if (err != 0 && err != -ENOENT)
96 udev_selinux_setfscreatecon(udev, file, mode);
97 err = mknod(file, mode, devnum);
100 udev_selinux_resetfscreatecon(udev);
101 } while (err == -ENOENT);
103 err(udev, "mknod(%s, %#o, (%u,%u) failed: %m\n", file, mode, major(devnum), minor(devnum));
104 info(udev, "set permissions %s, %#o, uid=%u, gid=%u\n", file, mode, uid, gid);
106 chown(file, uid, gid);
112 static int node_symlink(struct udev *udev, const char *node, const char *slink)
115 char target[UTIL_PATH_SIZE];
118 char slink_tmp[UTIL_PATH_SIZE + sizeof(TMP_FILE_EXT)];
123 /* use relative link */
125 while (node[i] && (node[i] == slink[i])) {
132 while (slink[i] != '\0') {
134 l = util_strpcpy(&s, l, "../");
137 l = util_strscpy(s, l, &node[tail]);
143 /* preserve link with correct target, do not replace node of other device */
144 if (lstat(slink, &stats) == 0) {
145 if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
148 info(udev, "found existing node instead of symlink '%s'\n", slink);
149 if (lstat(node, &stats2) == 0) {
150 if ((stats.st_mode & S_IFMT) == (stats2.st_mode & S_IFMT) &&
151 stats.st_rdev == stats2.st_rdev && stats.st_ino != stats2.st_ino) {
152 info(udev, "replace device node '%s' with symlink to our node '%s'\n",
155 err(udev, "device node '%s' already exists, "
156 "link to '%s' will not overwrite it\n",
161 } else if (S_ISLNK(stats.st_mode)) {
162 char buf[UTIL_PATH_SIZE];
165 dbg(udev, "found existing symlink '%s'\n", slink);
166 len = readlink(slink, buf, sizeof(buf));
167 if (len > 0 && len < (int)sizeof(buf)) {
169 if (strcmp(target, buf) == 0) {
170 info(udev, "preserve already existing symlink '%s' to '%s'\n",
172 udev_selinux_lsetfilecon(udev, slink, S_IFLNK);
173 utimensat(AT_FDCWD, slink, NULL, AT_SYMLINK_NOFOLLOW);
179 info(udev, "creating symlink '%s' to '%s'\n", slink, target);
181 err = util_create_path(udev, slink);
182 if (err != 0 && err != -ENOENT)
184 udev_selinux_setfscreatecon(udev, slink, S_IFLNK);
185 err = symlink(target, slink);
188 udev_selinux_resetfscreatecon(udev);
189 } while (err == -ENOENT);
194 info(udev, "atomically replace '%s'\n", slink);
195 util_strscpyl(slink_tmp, sizeof(slink_tmp), slink, TMP_FILE_EXT, NULL);
198 err = util_create_path(udev, slink_tmp);
199 if (err != 0 && err != -ENOENT)
201 udev_selinux_setfscreatecon(udev, slink_tmp, S_IFLNK);
202 err = symlink(target, slink_tmp);
205 udev_selinux_resetfscreatecon(udev);
206 } while (err == -ENOENT);
208 err(udev, "symlink(%s, %s) failed: %m\n", target, slink_tmp);
211 err = rename(slink_tmp, slink);
213 err(udev, "rename(%s, %s) failed: %m\n", slink_tmp, slink);
220 /* find device node of device with highest priority */
221 static const char *link_find_prioritized(struct udev_device *dev, bool add, const char *stackdir, char *buf, size_t bufsize)
223 struct udev *udev = udev_device_get_udev(dev);
226 const char *target = NULL;
229 priority = udev_device_get_devlink_priority(dev);
230 util_strscpy(buf, bufsize, udev_device_get_devnode(dev));
234 dir = opendir(stackdir);
238 struct udev_device *dev_db;
245 if (dent == NULL || dent->d_name[0] == '\0')
247 if (dent->d_name[0] == '.')
249 if (sscanf(dent->d_name, "%c%i:%i", &type, &maj, &min) != 3)
251 info(udev, "found '%c%i:%i' claiming '%s'\n", type, maj, min, stackdir);
252 devnum = makedev(maj, min);
254 /* did we find ourself? */
255 type2 = strcmp(udev_device_get_subsystem(dev), "block") == 0 ? 'b' : 'c';
256 if (udev_device_get_devnum(dev) == devnum && type == type2)
259 dev_db = udev_device_new_from_devnum(udev, type, devnum);
260 if (dev_db != NULL) {
263 devnode = udev_device_get_devnode(dev_db);
264 if (devnode != NULL) {
265 dbg(udev, "compare priority of '%s'(%i) > '%s'(%i)\n", target, priority,
266 udev_device_get_devnode(dev_db), udev_device_get_devlink_priority(dev_db));
267 if (target == NULL || udev_device_get_devlink_priority(dev_db) > priority) {
268 info(udev, "'%s' claims priority %i for '%s'\n",
269 udev_device_get_syspath(dev_db), udev_device_get_devlink_priority(dev_db), stackdir);
270 priority = udev_device_get_devlink_priority(dev_db);
271 util_strscpy(buf, bufsize, devnode);
275 udev_device_unref(dev_db);
282 /* manage "stack of names" with possibly specified device priorities */
283 static void link_update(struct udev_device *dev, const char *slink, bool add)
285 struct udev *udev = udev_device_get_udev(dev);
286 char name_enc[UTIL_PATH_SIZE];
287 char filename[UTIL_PATH_SIZE * 2];
288 char dirname[UTIL_PATH_SIZE];
290 char buf[UTIL_PATH_SIZE];
292 dbg(udev, "update symlink '%s' of '%s'\n", slink, udev_device_get_syspath(dev));
294 util_path_encode(&slink[strlen(udev_get_dev_path(udev))+1], name_enc, sizeof(name_enc));
295 snprintf(dirname, sizeof(dirname), "%s/.udev/links/%s", udev_get_dev_path(udev), name_enc);
296 snprintf(filename, sizeof(filename), "%s/%c%u:%u", dirname,
297 strcmp(udev_device_get_subsystem(dev), "block") == 0 ? 'b' : 'c',
298 major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)));
301 dbg(udev, "removing index: '%s'\n", filename);
303 util_delete_path(udev, filename);
306 target = link_find_prioritized(dev, add, dirname, buf, sizeof(buf));
307 if (target == NULL) {
308 info(udev, "no reference left, remove '%s'\n", slink);
310 util_delete_path(udev, slink);
312 info(udev, "creating link '%s' to '%s'\n", slink, target);
313 node_symlink(udev, target, slink);
319 dbg(udev, "creating index: '%s'\n", filename);
323 err = util_create_path(udev, filename);
324 if (err != 0 && err != -ENOENT)
326 fd = open(filename, O_WRONLY|O_CREAT|O_NOFOLLOW, 0444);
331 } while (err == -ENOENT);
335 void udev_node_update_old_links(struct udev_device *dev, struct udev_device *dev_old)
337 struct udev *udev = udev_device_get_udev(dev);
338 struct udev_list_entry *list_entry;
340 /* update possible left-over symlinks */
341 udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev_old)) {
342 const char *name = udev_list_entry_get_name(list_entry);
343 struct udev_list_entry *list_entry_current;
346 /* check if old link name still belongs to this device */
348 udev_list_entry_foreach(list_entry_current, udev_device_get_devlinks_list_entry(dev)) {
349 const char *name_current = udev_list_entry_get_name(list_entry_current);
351 if (strcmp(name, name_current) == 0) {
359 info(udev, "update old name, '%s' no longer belonging to '%s'\n",
360 name, udev_device_get_devpath(dev));
361 link_update(dev, name, 0);
365 int udev_node_add(struct udev_device *dev, mode_t mode, uid_t uid, gid_t gid)
367 struct udev *udev = udev_device_get_udev(dev);
368 struct udev_list_entry *list_entry;
371 info(udev, "creating device node '%s', devnum=%d:%d, mode=%#o, uid=%d, gid=%d\n",
372 udev_device_get_devnode(dev),
373 major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)),
376 if (udev_node_mknod(dev, NULL, makedev(0,0), mode, uid, gid) != 0) {
381 /* create/update symlinks, add symlinks to name index */
382 udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev)) {
383 if (udev_list_entry_get_flags(list_entry))
384 /* simple unmanaged link name */
385 node_symlink(udev, udev_device_get_devnode(dev), udev_list_entry_get_name(list_entry));
387 link_update(dev, udev_list_entry_get_name(list_entry), 1);
393 int udev_node_remove(struct udev_device *dev)
395 struct udev *udev = udev_device_get_udev(dev);
396 struct udev_list_entry *list_entry;
399 struct udev_device *dev_check;
400 char filename[UTIL_PATH_SIZE];
403 /* remove/update symlinks, remove symlinks from name index */
404 udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev))
405 link_update(dev, udev_list_entry_get_name(list_entry), 0);
407 devnode = udev_device_get_devnode(dev);
411 if (stat(devnode, &stats) != 0) {
412 info(udev, "device node '%s' not found\n", devnode);
416 if (stats.st_rdev != udev_device_get_devnum(dev)) {
417 info(udev, "device node '%s' points to a different device, skip removal\n", devnode);
422 dev_check = udev_device_new_from_syspath(udev, udev_device_get_syspath(dev));
423 if (dev_check != NULL) {
424 /* do not remove device node if the same sys-device is re-created in the meantime */
425 info(udev, "keeping device node of existing device'%s'\n", devnode);
426 udev_device_unref(dev_check);
430 util_strscpyl(filename, sizeof(filename), LIBEXECDIR "/devices", &devnode[strlen(udev_get_dev_path(udev))], NULL);
431 if (stat(filename, &stats) == 0 || stats.st_rdev == udev_device_get_devnum(dev)) {
432 info(udev, "static device entry found '%s', skip removal\n", devnode);
436 info(udev, "removing device node '%s'\n", devnode);
437 err = util_unlink_secure(udev, devnode);
438 util_delete_path(udev, devnode);