+++ /dev/null
-/*
- * Copyright (C) 2003-2010 Kay Sievers <kay.sievers@vrfy.org>
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include <stdlib.h>
-#include <string.h>
-#include <stdio.h>
-#include <stddef.h>
-#include <stdbool.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <errno.h>
-#include <grp.h>
-#include <dirent.h>
-#include <sys/time.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-
-#include "udev.h"
-
-#define TMP_FILE_EXT ".udev-tmp"
-
-static int node_symlink(struct udev *udev, const char *node, const char *slink)
-{
- struct stat stats;
- char target[UTIL_PATH_SIZE];
- char *s;
- size_t l;
- char slink_tmp[UTIL_PATH_SIZE + sizeof(TMP_FILE_EXT)];
- int i = 0;
- int tail = 0;
- int err = 0;
-
- /* use relative link */
- target[0] = '\0';
- while (node[i] && (node[i] == slink[i])) {
- if (node[i] == '/')
- tail = i+1;
- i++;
- }
- s = target;
- l = sizeof(target);
- while (slink[i] != '\0') {
- if (slink[i] == '/')
- l = util_strpcpy(&s, l, "../");
- i++;
- }
- l = util_strscpy(s, l, &node[tail]);
- if (l == 0) {
- err = -EINVAL;
- goto exit;
- }
-
- /* preserve link with correct target, do not replace node of other device */
- if (lstat(slink, &stats) == 0) {
- if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
- struct stat stats2;
-
- info(udev, "found existing node instead of symlink '%s'\n", slink);
- if (lstat(node, &stats2) == 0) {
- if ((stats.st_mode & S_IFMT) == (stats2.st_mode & S_IFMT) &&
- stats.st_rdev == stats2.st_rdev && stats.st_ino != stats2.st_ino) {
- info(udev, "replace device node '%s' with symlink to our node '%s'\n",
- slink, node);
- } else {
- err(udev, "device node '%s' already exists, "
- "link to '%s' will not overwrite it\n",
- slink, node);
- goto exit;
- }
- }
- } else if (S_ISLNK(stats.st_mode)) {
- char buf[UTIL_PATH_SIZE];
- int len;
-
- dbg(udev, "found existing symlink '%s'\n", slink);
- len = readlink(slink, buf, sizeof(buf));
- if (len > 0 && len < (int)sizeof(buf)) {
- buf[len] = '\0';
- if (strcmp(target, buf) == 0) {
- info(udev, "preserve already existing symlink '%s' to '%s'\n",
- slink, target);
- udev_selinux_lsetfilecon(udev, slink, S_IFLNK);
- utimensat(AT_FDCWD, slink, NULL, AT_SYMLINK_NOFOLLOW);
- goto exit;
- }
- }
- }
- } else {
- info(udev, "creating symlink '%s' to '%s'\n", slink, target);
- do {
- err = util_create_path_selinux(udev, slink);
- if (err != 0 && err != -ENOENT)
- break;
- udev_selinux_setfscreatecon(udev, slink, S_IFLNK);
- err = symlink(target, slink);
- if (err != 0)
- err = -errno;
- udev_selinux_resetfscreatecon(udev);
- } while (err == -ENOENT);
- if (err == 0)
- goto exit;
- }
-
- info(udev, "atomically replace '%s'\n", slink);
- util_strscpyl(slink_tmp, sizeof(slink_tmp), slink, TMP_FILE_EXT, NULL);
- unlink(slink_tmp);
- do {
- err = util_create_path_selinux(udev, slink_tmp);
- if (err != 0 && err != -ENOENT)
- break;
- udev_selinux_setfscreatecon(udev, slink_tmp, S_IFLNK);
- err = symlink(target, slink_tmp);
- if (err != 0)
- err = -errno;
- udev_selinux_resetfscreatecon(udev);
- } while (err == -ENOENT);
- if (err != 0) {
- err(udev, "symlink '%s' '%s' failed: %m\n", target, slink_tmp);
- goto exit;
- }
- err = rename(slink_tmp, slink);
- if (err != 0) {
- err(udev, "rename '%s' '%s' failed: %m\n", slink_tmp, slink);
- unlink(slink_tmp);
- }
-exit:
- return err;
-}
-
-/* find device node of device with highest priority */
-static const char *link_find_prioritized(struct udev_device *dev, bool add, const char *stackdir, char *buf, size_t bufsize)
-{
- struct udev *udev = udev_device_get_udev(dev);
- DIR *dir;
- int priority = 0;
- const char *target = NULL;
-
- if (add) {
- priority = udev_device_get_devlink_priority(dev);
- util_strscpy(buf, bufsize, udev_device_get_devnode(dev));
- target = buf;
- }
-
- dir = opendir(stackdir);
- if (dir == NULL)
- return target;
- for (;;) {
- struct udev_device *dev_db;
- struct dirent *dent;
-
- dent = readdir(dir);
- if (dent == NULL || dent->d_name[0] == '\0')
- break;
- if (dent->d_name[0] == '.')
- continue;
-
- info(udev, "found '%s' claiming '%s'\n", dent->d_name, stackdir);
-
- /* did we find ourself? */
- if (strcmp(dent->d_name, udev_device_get_id_filename(dev)) == 0)
- continue;
-
- dev_db = udev_device_new_from_id_filename(udev, dent->d_name);
- if (dev_db != NULL) {
- const char *devnode;
-
- devnode = udev_device_get_devnode(dev_db);
- if (devnode != NULL) {
- dbg(udev, "compare priority of '%s'(%i) > '%s'(%i)\n", target, priority,
- udev_device_get_devnode(dev_db), udev_device_get_devlink_priority(dev_db));
- if (target == NULL || udev_device_get_devlink_priority(dev_db) > priority) {
- info(udev, "'%s' claims priority %i for '%s'\n",
- udev_device_get_syspath(dev_db), udev_device_get_devlink_priority(dev_db), stackdir);
- priority = udev_device_get_devlink_priority(dev_db);
- util_strscpy(buf, bufsize, devnode);
- target = buf;
- }
- }
- udev_device_unref(dev_db);
- }
- }
- closedir(dir);
- return target;
-}
-
-/* manage "stack of names" with possibly specified device priorities */
-static void link_update(struct udev_device *dev, const char *slink, bool add)
-{
- struct udev *udev = udev_device_get_udev(dev);
- char name_enc[UTIL_PATH_SIZE];
- char filename[UTIL_PATH_SIZE * 2];
- char dirname[UTIL_PATH_SIZE];
- const char *target;
- char buf[UTIL_PATH_SIZE];
-
- dbg(udev, "update symlink '%s' of '%s'\n", slink, udev_device_get_syspath(dev));
-
- util_path_encode(&slink[strlen(udev_get_dev_path(udev))+1], name_enc, sizeof(name_enc));
- util_strscpyl(dirname, sizeof(dirname), udev_get_run_path(udev), "/links/", name_enc, NULL);
- util_strscpyl(filename, sizeof(filename), dirname, "/", udev_device_get_id_filename(dev), NULL);
-
- if (!add) {
- dbg(udev, "removing index: '%s'\n", filename);
- if (unlink(filename) == 0)
- rmdir(dirname);
- }
-
- target = link_find_prioritized(dev, add, dirname, buf, sizeof(buf));
- if (target == NULL) {
- info(udev, "no reference left, remove '%s'\n", slink);
- if (unlink(slink) == 0)
- util_delete_path(udev, slink);
- } else {
- info(udev, "creating link '%s' to '%s'\n", slink, target);
- node_symlink(udev, target, slink);
- }
-
- if (add) {
- int err;
-
- dbg(udev, "creating index: '%s'\n", filename);
- do {
- int fd;
-
- err = util_create_path(udev, filename);
- if (err != 0 && err != -ENOENT)
- break;
- fd = open(filename, O_WRONLY|O_CREAT|O_CLOEXEC|O_TRUNC|O_NOFOLLOW, 0444);
- if (fd >= 0)
- close(fd);
- else
- err = -errno;
- } while (err == -ENOENT);
- }
-}
-
-void udev_node_update_old_links(struct udev_device *dev, struct udev_device *dev_old)
-{
- struct udev *udev = udev_device_get_udev(dev);
- struct udev_list_entry *list_entry;
-
- /* update possible left-over symlinks */
- udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev_old)) {
- const char *name = udev_list_entry_get_name(list_entry);
- struct udev_list_entry *list_entry_current;
- int found;
-
- /* check if old link name still belongs to this device */
- found = 0;
- udev_list_entry_foreach(list_entry_current, udev_device_get_devlinks_list_entry(dev)) {
- const char *name_current = udev_list_entry_get_name(list_entry_current);
-
- if (strcmp(name, name_current) == 0) {
- found = 1;
- break;
- }
- }
- if (found)
- continue;
-
- info(udev, "update old name, '%s' no longer belonging to '%s'\n",
- name, udev_device_get_devpath(dev));
- link_update(dev, name, 0);
- }
-}
-
-static int node_fixup(struct udev_device *dev, mode_t mode, uid_t uid, gid_t gid)
-{
- struct udev *udev = udev_device_get_udev(dev);
- const char *devnode = udev_device_get_devnode(dev);
- dev_t devnum = udev_device_get_devnum(dev);
- struct stat stats;
- int err = 0;
-
- if (strcmp(udev_device_get_subsystem(dev), "block") == 0)
- mode |= S_IFBLK;
- else
- mode |= S_IFCHR;
-
- if (lstat(devnode, &stats) != 0) {
- err = -errno;
- info(udev, "can not stat() node '%s' (%m)\n", devnode);
- goto out;
- }
-
- if (((stats.st_mode & S_IFMT) != (mode & S_IFMT)) || (stats.st_rdev != devnum)) {
- err = -EEXIST;
- info(udev, "found node '%s' with non-matching devnum %s, skip handling\n",
- udev_device_get_devnode(dev), udev_device_get_id_filename(dev));
- goto out;
- }
-
- if ((stats.st_mode & 0777) != (mode & 0777) || stats.st_uid != uid || stats.st_gid != gid) {
- info(udev, "set permissions %s, %#o, uid=%u, gid=%u\n", devnode, mode, uid, gid);
- chmod(devnode, mode);
- chown(devnode, uid, gid);
- } else {
- info(udev, "preserve permissions %s, %#o, uid=%u, gid=%u\n", devnode, mode, uid, gid);
- }
-
- /*
- * Set initial selinux file context only on add events.
- * We set the proper context on bootup (triger) or for newly
- * added devices, but we don't change it later, in case
- * something else has set a custom context in the meantime.
- */
- if (strcmp(udev_device_get_action(dev), "add") == 0)
- udev_selinux_lsetfilecon(udev, devnode, mode);
-
- /* always update timestamp when we re-use the node, like on media change events */
- utimensat(AT_FDCWD, devnode, NULL, 0);
-out:
- return err;
-}
-
-int udev_node_add(struct udev_device *dev, mode_t mode, uid_t uid, gid_t gid)
-{
- struct udev *udev = udev_device_get_udev(dev);
- char filename[UTIL_PATH_SIZE];
- struct udev_list_entry *list_entry;
- int err = 0;
-
- info(udev, "handling device node '%s', devnum=%s, mode=%#o, uid=%d, gid=%d\n",
- udev_device_get_devnode(dev), udev_device_get_id_filename(dev), mode, uid, gid);
-
- err = node_fixup(dev, mode, uid, gid);
- if (err < 0)
- goto exit;
-
- /* always add /dev/{block,char}/$major:$minor */
- snprintf(filename, sizeof(filename), "%s/%s/%u:%u",
- udev_get_dev_path(udev),
- strcmp(udev_device_get_subsystem(dev), "block") == 0 ? "block" : "char",
- major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)));
- node_symlink(udev, udev_device_get_devnode(dev), filename);
-
- /* create/update symlinks, add symlinks to name index */
- udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev)) {
- if (udev_list_entry_get_num(list_entry))
- /* simple unmanaged link name */
- node_symlink(udev, udev_device_get_devnode(dev), udev_list_entry_get_name(list_entry));
- else
- link_update(dev, udev_list_entry_get_name(list_entry), 1);
- }
-exit:
- return err;
-}
-
-int udev_node_remove(struct udev_device *dev)
-{
- struct udev *udev = udev_device_get_udev(dev);
- struct udev_list_entry *list_entry;
- const char *devnode;
- struct stat stats;
- struct udev_device *dev_check;
- char filename[UTIL_PATH_SIZE];
- int err = 0;
-
- /* remove/update symlinks, remove symlinks from name index */
- udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev))
- link_update(dev, udev_list_entry_get_name(list_entry), 0);
-
- /* remove /dev/{block,char}/$major:$minor */
- snprintf(filename, sizeof(filename), "%s/%s/%u:%u",
- udev_get_dev_path(udev),
- strcmp(udev_device_get_subsystem(dev), "block") == 0 ? "block" : "char",
- major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)));
- unlink(filename);
-out:
- return err;
-}
~ianmdlvl / elogind.git / blobdiff