2 * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
3 * Copyright (C) 2004-2006 Kay Sievers <kay.sievers@vrfy.org>
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation version 2 of the License.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
30 #include <sys/types.h>
33 #include "udev_rules.h"
34 #include "udev_selinux.h"
36 #define TMP_FILE_EXT ".udev-tmp"
38 int udev_node_mknod(struct udevice *udev, const char *file, dev_t devt, mode_t mode, uid_t uid, gid_t gid)
40 char file_tmp[PATH_SIZE + sizeof(TMP_FILE_EXT)];
44 if (major(devt) != 0 && strcmp(udev->dev->subsystem, "block") == 0)
49 /* preserve node with already correct numbers, to prevent changing the inode number */
50 if (lstat(file, &stats) == 0) {
51 if ((stats.st_mode & S_IFMT) == (mode & S_IFMT) && (stats.st_rdev == devt)) {
52 info("preserve file '%s', because it has correct dev_t", file);
53 selinux_setfilecon(file, udev->dev->kernel, stats.st_mode);
58 selinux_setfscreatecon(file, udev->dev->kernel, mode);
59 retval = mknod(file, mode, devt);
60 selinux_resetfscreatecon();
64 info("atomically replace '%s'", file);
65 strlcpy(file_tmp, file, sizeof(file_tmp));
66 strlcat(file_tmp, TMP_FILE_EXT, sizeof(file_tmp));
67 selinux_setfscreatecon(file_tmp, udev->dev->kernel, mode);
68 retval = mknod(file_tmp, mode, devt);
69 selinux_resetfscreatecon();
71 err("mknod(%s, %#o, %u, %u) failed: %s",
72 file_tmp, mode, major(devt), minor(devt), strerror(errno));
75 retval = rename(file_tmp, file);
77 err("rename(%s, %s) failed: %s",
78 file_tmp, file, strerror(errno));
84 dbg("chmod(%s, %#o)", file, mode);
85 if (chmod(file, mode) != 0) {
86 err("chmod(%s, %#o) failed: %s", file, mode, strerror(errno));
90 if (uid != 0 || gid != 0) {
91 dbg("chown(%s, %u, %u)", file, uid, gid);
92 if (chown(file, uid, gid) != 0) {
93 err("chown(%s, %u, %u) failed: %s",
94 file, uid, gid, strerror(errno));
102 static int node_symlink(const char *node, const char *slink)
105 char target[PATH_SIZE] = "";
106 char slink_tmp[PATH_SIZE + sizeof(TMP_FILE_EXT)];
112 /* use relative link */
113 while (node[i] && (node[i] == slink[i])) {
118 while (slink[i] != '\0') {
120 strlcat(target, "../", sizeof(target));
123 strlcat(target, &node[tail], sizeof(target));
125 /* preserve link with correct target, do not replace node of other device */
126 if (lstat(slink, &stats) == 0) {
127 if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
130 info("found existing node instead of symlink '%s'", slink);
131 if (lstat(node, &stats2) == 0) {
132 if ((stats.st_mode & S_IFMT) == (stats2.st_mode & S_IFMT) &&
133 stats.st_rdev == stats2.st_rdev) {
134 info("replace device node '%s' with symlink to our node '%s'", slink, node);
136 err("device node '%s' already exists, link '%s' will not overwrite it", node, slink);
140 } else if (S_ISLNK(stats.st_mode)) {
143 info("found existing symlink '%s'", slink);
144 len = readlink(slink, buf, sizeof(buf));
147 if (strcmp(target, buf) == 0) {
148 info("preserve already existing symlink '%s' to '%s'", slink, target);
149 selinux_setfilecon(slink, NULL, S_IFLNK);
156 info("creating symlink '%s' to '%s'", slink, target);
157 selinux_setfscreatecon(slink, NULL, S_IFLNK);
158 retval = symlink(target, slink);
159 selinux_resetfscreatecon();
163 info("atomically replace '%s'", slink);
164 strlcpy(slink_tmp, slink, sizeof(slink_tmp));
165 strlcat(slink_tmp, TMP_FILE_EXT, sizeof(slink_tmp));
166 selinux_setfscreatecon(slink_tmp, NULL, S_IFLNK);
167 retval = symlink(target, slink_tmp);
168 selinux_resetfscreatecon();
170 err("symlink(%s, %s) failed: %s", target, slink_tmp, strerror(errno));
173 retval = rename(slink_tmp, slink);
175 err("rename(%s, %s) failed: %s", slink_tmp, slink, strerror(errno));
183 static int update_link(struct udevice *udev, const char *name)
185 LIST_HEAD(name_list);
186 char slink[PATH_SIZE];
187 char node[PATH_SIZE];
188 struct udevice *udev_db;
189 struct name_entry *device;
190 char target[PATH_MAX] = "";
195 strlcpy(slink, udev_root, sizeof(slink));
196 strlcat(slink, "/", sizeof(slink));
197 strlcat(slink, name, sizeof(slink));
199 count = udev_db_get_devices_by_name(name, &name_list);
200 info("found %i devices with name '%s'", count, name);
202 /* if we don't have a reference, delete it */
204 info("no reference left, remove '%s'", name);
205 if (!udev->test_run) {
212 /* find the device with the highest priority */
213 list_for_each_entry(device, &name_list, node) {
214 info("found '%s' for '%s'", device->name, name);
216 /* did we find ourself? we win, if we have the same priority */
217 if (strcmp(udev->dev->devpath, device->name) == 0) {
218 info("compare (our own) priority of '%s' %i >= %i",
219 udev->dev->devpath, udev->link_priority, priority);
220 if (target[0] == '\0' || udev->link_priority >= priority) {
221 priority = udev->link_priority;
222 strlcpy(target, udev->name, sizeof(target));
227 /* or something else, then read priority from database */
228 udev_db = udev_device_init(NULL);
231 if (udev_db_get_device(udev_db, device->name) == 0) {
232 info("compare priority of '%s' %i > %i",
233 udev_db->dev->devpath, udev_db->link_priority, priority);
234 if (target[0] == '\0' || udev_db->link_priority > priority) {
235 priority = udev_db->link_priority;
236 strlcpy(target, udev_db->name, sizeof(target));
239 udev_device_cleanup(udev_db);
241 name_list_cleanup(&name_list);
243 if (target[0] == '\0') {
244 err("missing target for '%s'", name);
249 /* create symlink to the target with the highest priority */
250 strlcpy(node, udev_root, sizeof(node));
251 strlcat(node, "/", sizeof(node));
252 strlcat(node, target, sizeof(node));
253 info("'%s' with target '%s' has the highest priority %i, create it", name, target, priority);
254 if (!udev->test_run) {
256 node_symlink(node, slink);
262 void udev_node_update_symlinks(struct udevice *udev, struct udevice *udev_old)
264 struct name_entry *name_loop;
265 char symlinks[PATH_SIZE] = "";
267 list_for_each_entry(name_loop, &udev->symlink_list, node) {
268 info("update symlink '%s' of '%s'", name_loop->name, udev->dev->devpath);
269 update_link(udev, name_loop->name);
270 strlcat(symlinks, udev_root, sizeof(symlinks));
271 strlcat(symlinks, "/", sizeof(symlinks));
272 strlcat(symlinks, name_loop->name, sizeof(symlinks));
273 strlcat(symlinks, " ", sizeof(symlinks));
276 /* export symlinks to environment */
277 remove_trailing_chars(symlinks, ' ');
278 if (symlinks[0] != '\0')
279 setenv("DEVLINKS", symlinks, 1);
281 /* update possible left-over symlinks (device metadata changed) */
282 if (udev_old != NULL) {
283 struct name_entry *link_loop;
284 struct name_entry *link_old_loop;
287 /* remove current symlinks from old list */
288 list_for_each_entry(link_old_loop, &udev_old->symlink_list, node) {
290 list_for_each_entry(link_loop, &udev->symlink_list, node) {
291 if (strcmp(link_old_loop->name, link_loop->name) == 0) {
297 /* link does no longer belong to this device */
298 info("update old symlink '%s' no longer belonging to '%s'",
299 link_old_loop->name, udev->dev->devpath);
300 update_link(udev, link_old_loop->name);
305 * if the node name has changed, delete the node,
306 * or possibly restore a symlink of another device
308 if (strcmp(udev->name, udev_old->name) != 0)
309 update_link(udev, udev_old->name);
313 int udev_node_add(struct udevice *udev)
315 char filename[PATH_SIZE];
321 strlcpy(filename, udev_root, sizeof(filename));
322 strlcat(filename, "/", sizeof(filename));
323 strlcat(filename, udev->name, sizeof(filename));
324 create_path(filename);
326 if (strcmp(udev->owner, "root") == 0)
332 id = strtoul(udev->owner, &endptr, 10);
333 if (endptr[0] == '\0')
336 uid = lookup_user(udev->owner);
339 if (strcmp(udev->group, "root") == 0)
345 id = strtoul(udev->group, &endptr, 10);
346 if (endptr[0] == '\0')
349 gid = lookup_group(udev->group);
352 info("creating device node '%s', major=%d, minor=%d, mode=%#o, uid=%d, gid=%d",
353 filename, major(udev->devt), minor(udev->devt), udev->mode, uid, gid);
356 if (udev_node_mknod(udev, filename, udev->devt, udev->mode, uid, gid) != 0) {
361 setenv("DEVNAME", filename, 1);
363 /* create all_partitions if requested */
364 if (udev->partitions) {
365 char partitionname[PATH_SIZE];
369 /* take the maximum registered minor range */
370 attr = sysfs_attr_get_value(udev->dev->devpath, "range");
374 udev->partitions = range-1;
376 info("creating device partition nodes '%s[1-%i]'", filename, udev->partitions);
377 if (!udev->test_run) {
378 for (i = 1; i <= udev->partitions; i++) {
381 snprintf(partitionname, sizeof(partitionname), "%s%d", filename, i);
382 partitionname[sizeof(partitionname)-1] = '\0';
383 part_devt = makedev(major(udev->devt), minor(udev->devt) + i);
384 udev_node_mknod(udev, partitionname, part_devt, udev->mode, uid, gid);
392 int udev_node_remove(struct udevice *udev)
394 char filename[PATH_SIZE];
395 char partitionname[PATH_SIZE];
400 strlcpy(filename, udev_root, sizeof(filename));
401 strlcat(filename, "/", sizeof(filename));
402 strlcat(filename, udev->name, sizeof(filename));
403 if (stat(filename, &stats) != 0) {
404 dbg("device node '%s' not found", filename);
407 if (udev->devt && stats.st_rdev != udev->devt) {
408 info("device node '%s' points to a different device, skip removal", filename);
412 info("removing device node '%s'", filename);
414 retval = unlink_secure(filename);
418 setenv("DEVNAME", filename, 1);
419 num = udev->partitions;
423 info("removing all_partitions '%s[1-%i]'", filename, num);
426 for (i = 1; i <= num; i++) {
427 snprintf(partitionname, sizeof(partitionname), "%s%d", filename, i);
428 partitionname[sizeof(partitionname)-1] = '\0';
430 unlink_secure(partitionname);
433 delete_path(filename);