2 * Copyright (C) 2003-2009 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);
43 if (major(devnum) == 0)
44 devnum = udev_device_get_devnum(dev);
46 if (strcmp(udev_device_get_subsystem(dev), "block") == 0)
52 file = udev_device_get_devnode(dev);
54 if (lstat(file, &stats) == 0) {
55 if (((stats.st_mode & S_IFMT) == (mode & S_IFMT)) && (stats.st_rdev == devnum)) {
56 info(udev, "preserve file '%s', because it has correct dev_t\n", file);
58 udev_selinux_lsetfilecon(udev, file, mode);
59 /* update time stamp when we re-use the node, like on media change events */
60 utimensat(AT_FDCWD, file, NULL, 0);
62 char file_tmp[UTIL_PATH_SIZE + sizeof(TMP_FILE_EXT)];
64 info(udev, "atomically replace existing file '%s'\n", file);
65 util_strscpyl(file_tmp, sizeof(file_tmp), file, TMP_FILE_EXT, NULL);
67 udev_selinux_setfscreatecon(udev, file_tmp, mode);
68 err = mknod(file_tmp, mode, devnum);
69 udev_selinux_resetfscreatecon(udev);
71 err(udev, "mknod(%s, %#o, %u, %u) failed: %m\n",
72 file_tmp, mode, major(devnum), minor(devnum));
75 err = rename(file_tmp, file);
77 err(udev, "rename(%s, %s) failed: %m\n", file_tmp, file);
82 info(udev, "mknod(%s, %#o, (%u,%u))\n", file, mode, major(devnum), minor(devnum));
84 err = util_create_path(udev, file);
85 if (err != 0 && err != -ENOENT)
87 udev_selinux_setfscreatecon(udev, file, mode);
88 err = mknod(file, mode, devnum);
91 udev_selinux_resetfscreatecon(udev);
92 } while (err == -ENOENT);
94 err(udev, "mknod(%s, %#o, (%u,%u) failed: %m\n", file, mode, major(devnum), minor(devnum));
99 if (!preserve || stats.st_mode != mode) {
100 info(udev, "chmod(%s, %#o)\n", file, mode);
101 err = chmod(file, mode);
103 err(udev, "chmod(%s, %#o) failed: %m\n", file, mode);
108 if (!preserve || stats.st_uid != uid || stats.st_gid != gid) {
109 info(udev, "chown(%s, %u, %u)\n", file, uid, gid);
110 err = chown(file, uid, gid);
112 err(udev, "chown(%s, %u, %u) failed: %m\n", file, uid, gid);
120 static int node_symlink(struct udev *udev, const char *node, const char *slink)
123 char target[UTIL_PATH_SIZE];
126 char slink_tmp[UTIL_PATH_SIZE + sizeof(TMP_FILE_EXT)];
131 /* use relative link */
133 while (node[i] && (node[i] == slink[i])) {
140 while (slink[i] != '\0') {
142 l = util_strpcpy(&s, l, "../");
145 l = util_strscpy(s, l, &node[tail]);
151 /* preserve link with correct target, do not replace node of other device */
152 if (lstat(slink, &stats) == 0) {
153 if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
156 info(udev, "found existing node instead of symlink '%s'\n", slink);
157 if (lstat(node, &stats2) == 0) {
158 if ((stats.st_mode & S_IFMT) == (stats2.st_mode & S_IFMT) &&
159 stats.st_rdev == stats2.st_rdev && stats.st_ino != stats2.st_ino) {
160 info(udev, "replace device node '%s' with symlink to our node '%s'\n",
163 err(udev, "device node '%s' already exists, "
164 "link to '%s' will not overwrite it\n",
169 } else if (S_ISLNK(stats.st_mode)) {
170 char buf[UTIL_PATH_SIZE];
173 dbg(udev, "found existing symlink '%s'\n", slink);
174 len = readlink(slink, buf, sizeof(buf));
177 if (strcmp(target, buf) == 0) {
178 info(udev, "preserve already existing symlink '%s' to '%s'\n",
180 udev_selinux_lsetfilecon(udev, slink, S_IFLNK);
181 utimensat(AT_FDCWD, slink, NULL, AT_SYMLINK_NOFOLLOW);
187 info(udev, "creating symlink '%s' to '%s'\n", slink, target);
189 err = util_create_path(udev, slink);
190 if (err != 0 && err != -ENOENT)
192 udev_selinux_setfscreatecon(udev, slink, S_IFLNK);
193 err = symlink(target, slink);
196 udev_selinux_resetfscreatecon(udev);
197 } while (err == -ENOENT);
202 info(udev, "atomically replace '%s'\n", slink);
203 util_strscpyl(slink_tmp, sizeof(slink_tmp), slink, TMP_FILE_EXT, NULL);
206 err = util_create_path(udev, slink_tmp);
207 if (err != 0 && err != -ENOENT)
209 udev_selinux_setfscreatecon(udev, slink_tmp, S_IFLNK);
210 err = symlink(target, slink_tmp);
213 udev_selinux_resetfscreatecon(udev);
214 } while (err == -ENOENT);
216 err(udev, "symlink(%s, %s) failed: %m\n", target, slink_tmp);
219 err = rename(slink_tmp, slink);
221 err(udev, "rename(%s, %s) failed: %m\n", slink_tmp, slink);
228 /* find device node of device with highest priority */
229 static const char *link_find_prioritized(struct udev_device *dev, bool add, const char *stackdir, char *buf, size_t bufsize)
231 struct udev *udev = udev_device_get_udev(dev);
234 const char *target = NULL;
237 priority = udev_device_get_devlink_priority(dev);
238 util_strscpy(buf, bufsize, udev_device_get_devnode(dev));
242 dir = opendir(stackdir);
246 struct udev_device *dev_db;
253 if (dent == NULL || dent->d_name[0] == '\0')
255 if (dent->d_name[0] == '.')
257 if (sscanf(dent->d_name, "%c%i:%i", &type, &maj, &min) != 3)
259 info(udev, "found '%c%i:%i' claiming '%s'\n", type, maj, min, stackdir);
260 devnum = makedev(maj, min);
262 /* did we find ourself? */
263 type2 = strcmp(udev_device_get_subsystem(dev), "block") == 0 ? 'b' : 'c';
264 if (udev_device_get_devnum(dev) == devnum && type == type2)
267 dev_db = udev_device_new_from_devnum(udev, type, devnum);
268 if (dev_db != NULL) {
271 devnode = udev_device_get_devnode(dev_db);
272 if (devnode != NULL) {
273 dbg(udev, "compare priority of '%s'(%i) > '%s'(%i)\n", target, priority,
274 udev_device_get_devnode(dev_db), udev_device_get_devlink_priority(dev_db));
275 if (target == NULL || udev_device_get_devlink_priority(dev_db) > priority) {
276 info(udev, "'%s' claims priority %i for '%s'\n",
277 udev_device_get_syspath(dev_db), udev_device_get_devlink_priority(dev_db), stackdir);
278 priority = udev_device_get_devlink_priority(dev_db);
279 util_strscpy(buf, bufsize, devnode);
283 udev_device_unref(dev_db);
290 /* manage "stack of names" with possibly specified device priorities */
291 static void link_update(struct udev_device *dev, const char *slink, bool add)
293 struct udev *udev = udev_device_get_udev(dev);
294 char name_enc[UTIL_PATH_SIZE];
295 char filename[UTIL_PATH_SIZE * 2];
296 char dirname[UTIL_PATH_SIZE];
298 char buf[UTIL_PATH_SIZE];
300 dbg(udev, "update symlink '%s' of '%s'\n", slink, udev_device_get_syspath(dev));
302 util_path_encode(&slink[strlen(udev_get_dev_path(udev))+1], name_enc, sizeof(name_enc));
303 snprintf(dirname, sizeof(dirname), "%s/.udev/links/%s", udev_get_dev_path(udev), name_enc);
304 snprintf(filename, sizeof(filename), "%s/%c%u:%u", dirname,
305 strcmp(udev_device_get_subsystem(dev), "block") == 0 ? 'b' : 'c',
306 major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)));
309 dbg(udev, "removing index: '%s'\n", filename);
311 util_delete_path(udev, filename);
314 target = link_find_prioritized(dev, add, dirname, buf, sizeof(buf));
315 if (target == NULL) {
316 info(udev, "no reference left, remove '%s'\n", slink);
318 util_delete_path(udev, slink);
320 info(udev, "creating link '%s' to '%s'\n", slink, target);
321 node_symlink(udev, target, slink);
327 dbg(udev, "creating index: '%s'\n", filename);
331 err = util_create_path(udev, filename);
332 if (err != 0 && err != -ENOENT)
334 fd = open(filename, O_WRONLY|O_CREAT, 0444);
339 } while (err == -ENOENT);
343 void udev_node_update_old_links(struct udev_device *dev, struct udev_device *dev_old)
345 struct udev *udev = udev_device_get_udev(dev);
346 struct udev_list_entry *list_entry;
348 /* update possible left-over symlinks */
349 udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev_old)) {
350 const char *name = udev_list_entry_get_name(list_entry);
351 struct udev_list_entry *list_entry_current;
354 /* check if old link name still belongs to this device */
356 udev_list_entry_foreach(list_entry_current, udev_device_get_devlinks_list_entry(dev)) {
357 const char *name_current = udev_list_entry_get_name(list_entry_current);
359 if (strcmp(name, name_current) == 0) {
367 info(udev, "update old name, '%s' no longer belonging to '%s'\n",
368 name, udev_device_get_devpath(dev));
369 link_update(dev, name, 0);
373 int udev_node_add(struct udev_device *dev, mode_t mode, uid_t uid, gid_t gid)
375 struct udev *udev = udev_device_get_udev(dev);
378 struct udev_list_entry *list_entry;
381 info(udev, "creating device node '%s', devnum=%d:%d, mode=%#o, uid=%d, gid=%d\n",
382 udev_device_get_devnode(dev),
383 major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)),
386 if (udev_node_mknod(dev, NULL, makedev(0,0), mode, uid, gid) != 0) {
391 /* create all_partitions if requested */
392 num = udev_device_get_num_fake_partitions(dev);
394 info(udev, "creating device partition nodes '%s[1-%i]'\n", udev_device_get_devnode(dev), num);
395 for (i = 1; i <= num; i++) {
396 char partitionname[UTIL_PATH_SIZE];
399 snprintf(partitionname, sizeof(partitionname), "%s%d",
400 udev_device_get_devnode(dev), i);
401 partitionname[sizeof(partitionname)-1] = '\0';
402 part_devnum = makedev(major(udev_device_get_devnum(dev)),
403 minor(udev_device_get_devnum(dev)) + i);
404 udev_node_mknod(dev, partitionname, part_devnum, mode, uid, gid);
408 /* create/update symlinks, add symlinks to name index */
409 udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev)) {
410 if (udev_list_entry_get_flags(list_entry))
411 /* simple unmanaged link name */
412 node_symlink(udev, udev_device_get_devnode(dev), udev_list_entry_get_name(list_entry));
414 link_update(dev, udev_list_entry_get_name(list_entry), 1);
420 int udev_node_remove(struct udev_device *dev)
422 struct udev *udev = udev_device_get_udev(dev);
423 struct udev_list_entry *list_entry;
425 char partitionname[UTIL_PATH_SIZE];
427 struct udev_device *dev_check;
431 /* remove/update symlinks, remove symlinks from name index */
432 udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev))
433 link_update(dev, udev_list_entry_get_name(list_entry), 0);
435 devnode = udev_device_get_devnode(dev);
438 if (stat(devnode, &stats) != 0) {
439 info(udev, "device node '%s' not found\n", devnode);
442 if (stats.st_rdev != udev_device_get_devnum(dev)) {
443 info(udev, "device node '%s' points to a different device, skip removal\n", devnode);
447 dev_check = udev_device_new_from_syspath(udev, udev_device_get_syspath(dev));
448 if (dev_check != NULL && stats.st_rdev == udev_device_get_devnum(dev_check)) {
449 /* do not remove device node if the same sys-device is re-created in the meantime */
450 info(udev, "keeping device node of existing device'%s'\n", devnode);
452 info(udev, "removing device node '%s'\n", devnode);
453 err = util_unlink_secure(udev, devnode);
455 udev_device_unref(dev_check);
457 num = udev_device_get_num_fake_partitions(dev);
461 info(udev, "removing all_partitions '%s[1-%i]'\n", devnode, num);
464 for (i = 1; i <= num; i++) {
465 snprintf(partitionname, sizeof(partitionname), "%s%d", devnode, i);
466 partitionname[sizeof(partitionname)-1] = '\0';
467 util_unlink_secure(udev, partitionname);
470 util_delete_path(udev, devnode);