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mirror of https://github.com/systemd/systemd-stable.git synced 2024-12-24 21:34:08 +03:00
systemd-stable/udev_node.c
2006-08-28 00:29:11 +02:00

340 lines
8.6 KiB
C

/*
* Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (C) 2004-2006 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 version 2 of the License.
*
* 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, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <stddef.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <grp.h>
#include <sys/stat.h>
#include <sys/types.h>
#include "udev.h"
#include "udev_rules.h"
#include "udev_selinux.h"
int udev_node_mknod(struct udevice *udev, const char *file, dev_t devt, mode_t mode, uid_t uid, gid_t gid)
{
struct stat stats;
int retval = 0;
if (major(devt) != 0 && strcmp(udev->dev->subsystem, "block") == 0)
mode |= S_IFBLK;
else
mode |= S_IFCHR;
if (stat(file, &stats) != 0)
goto create;
/* preserve node with already correct numbers, to prevent changing the inode number */
if ((stats.st_mode & S_IFMT) == (mode & S_IFMT) && (stats.st_rdev == devt)) {
info("preserve file '%s', because it has correct dev_t", file);
selinux_setfilecon(file, udev->dev->kernel, stats.st_mode);
goto perms;
}
if (unlink(file) != 0)
err("unlink(%s) failed: %s", file, strerror(errno));
else
dbg("already present file '%s' unlinked", file);
create:
selinux_setfscreatecon(file, udev->dev->kernel, mode);
retval = mknod(file, mode, devt);
selinux_resetfscreatecon();
if (retval != 0) {
err("mknod(%s, %#o, %u, %u) failed: %s",
file, mode, major(devt), minor(devt), strerror(errno));
goto exit;
}
perms:
dbg("chmod(%s, %#o)", file, mode);
if (chmod(file, mode) != 0) {
err("chmod(%s, %#o) failed: %s", file, mode, strerror(errno));
goto exit;
}
if (uid != 0 || gid != 0) {
dbg("chown(%s, %u, %u)", file, uid, gid);
if (chown(file, uid, gid) != 0) {
err("chown(%s, %u, %u) failed: %s",
file, uid, gid, strerror(errno));
goto exit;
}
}
exit:
return retval;
}
static int udev_node_symlink(struct udevice *udev, const char *linktarget, const char *filename)
{
char target[PATH_SIZE];
int len;
/* look if symlink already exists */
len = readlink(filename, target, sizeof(target));
if (len > 0) {
target[len] = '\0';
if (strcmp(linktarget, target) == 0) {
info("preserving symlink '%s' to '%s'", filename, linktarget);
selinux_setfilecon(filename, NULL, S_IFLNK);
goto exit;
} else {
info("link '%s' points to different target '%s', delete it", filename, target);
unlink(filename);
}
}
/* create link */
info("creating symlink '%s' to '%s'", filename, linktarget);
selinux_setfscreatecon(filename, NULL, S_IFLNK);
if (symlink(linktarget, filename) != 0)
err("symlink(%s, %s) failed: %s", linktarget, filename, strerror(errno));
selinux_resetfscreatecon();
exit:
return 0;
}
int udev_node_add(struct udevice *udev, struct udevice *udev_old)
{
char filename[PATH_SIZE];
struct name_entry *name_loop;
uid_t uid;
gid_t gid;
int tail;
int i;
int retval = 0;
snprintf(filename, sizeof(filename), "%s/%s", udev_root, udev->name);
filename[sizeof(filename)-1] = '\0';
/* create parent directories if needed */
if (strchr(udev->name, '/'))
create_path(filename);
if (strcmp(udev->owner, "root") == 0)
uid = 0;
else {
char *endptr;
unsigned long id;
id = strtoul(udev->owner, &endptr, 10);
if (endptr[0] == '\0')
uid = (uid_t) id;
else
uid = lookup_user(udev->owner);
}
if (strcmp(udev->group, "root") == 0)
gid = 0;
else {
char *endptr;
unsigned long id;
id = strtoul(udev->group, &endptr, 10);
if (endptr[0] == '\0')
gid = (gid_t) id;
else
gid = lookup_group(udev->group);
}
info("creating device node '%s', major = '%d', minor = '%d', " "mode = '%#o', uid = '%d', gid = '%d'",
filename, major(udev->devt), minor(udev->devt), udev->mode, uid, gid);
if (!udev->test_run)
if (udev_node_mknod(udev, filename, udev->devt, udev->mode, uid, gid) != 0) {
retval = -1;
goto exit;
}
setenv("DEVNAME", filename, 1);
/* create all_partitions if requested */
if (udev->partitions) {
char partitionname[PATH_SIZE];
char *attr;
int range;
/* take the maximum registered minor range */
attr = sysfs_attr_get_value(udev->dev->devpath, "range");
if (attr) {
range = atoi(attr);
if (range > 1)
udev->partitions = range-1;
}
info("creating device partition nodes '%s[1-%i]'", filename, udev->partitions);
if (!udev->test_run) {
for (i = 1; i <= udev->partitions; i++) {
dev_t part_devt;
snprintf(partitionname, sizeof(partitionname), "%s%d", filename, i);
partitionname[sizeof(partitionname)-1] = '\0';
part_devt = makedev(major(udev->devt), minor(udev->devt) + i);
udev_node_mknod(udev, partitionname, part_devt, udev->mode, uid, gid);
}
}
}
/* create symlink(s) if requested */
if (!list_empty(&udev->symlink_list)) {
char symlinks[512] = "";
list_for_each_entry(name_loop, &udev->symlink_list, node) {
char linktarget[PATH_SIZE];
snprintf(filename, sizeof(filename), "%s/%s", udev_root, name_loop->name);
filename[sizeof(filename)-1] = '\0';
dbg("symlink '%s' to node '%s' requested", filename, udev->name);
if (!udev->test_run)
if (strchr(filename, '/'))
create_path(filename);
/* optimize relative link */
linktarget[0] = '\0';
i = 0;
tail = 0;
while (udev->name[i] && (udev->name[i] == name_loop->name[i])) {
if (udev->name[i] == '/')
tail = i+1;
i++;
}
while (name_loop->name[i] != '\0') {
if (name_loop->name[i] == '/')
strlcat(linktarget, "../", sizeof(linktarget));
i++;
}
strlcat(linktarget, &udev->name[tail], sizeof(linktarget));
info("creating symlink '%s' to '%s'", filename, linktarget);
if (!udev->test_run)
udev_node_symlink(udev, linktarget, filename);
strlcat(symlinks, filename, sizeof(symlinks));
strlcat(symlinks, " ", sizeof(symlinks));
}
remove_trailing_chars(symlinks, ' ');
setenv("DEVLINKS", symlinks, 1);
}
exit:
selinux_exit();
return retval;
}
void udev_node_remove_symlinks(struct udevice *udev)
{
char filename[PATH_SIZE];
struct name_entry *name_loop;
struct stat stats;
if (!list_empty(&udev->symlink_list)) {
char symlinks[512] = "";
list_for_each_entry(name_loop, &udev->symlink_list, node) {
snprintf(filename, sizeof(filename), "%s/%s", udev_root, name_loop->name);
filename[sizeof(filename)-1] = '\0';
if (stat(filename, &stats) != 0) {
dbg("symlink '%s' not found", filename);
continue;
}
if (udev->devt && stats.st_rdev != udev->devt) {
info("symlink '%s' points to a different device, skip removal", filename);
continue;
}
info("removing symlink '%s'", filename);
if (!udev->test_run) {
unlink(filename);
if (strchr(filename, '/'))
delete_path(filename);
}
strlcat(symlinks, filename, sizeof(symlinks));
strlcat(symlinks, " ", sizeof(symlinks));
}
remove_trailing_chars(symlinks, ' ');
if (symlinks[0] != '\0')
setenv("DEVLINKS", symlinks, 1);
}
}
int udev_node_remove(struct udevice *udev)
{
char filename[PATH_SIZE];
char partitionname[PATH_SIZE];
struct stat stats;
int retval;
int num;
udev_node_remove_symlinks(udev);
snprintf(filename, sizeof(filename), "%s/%s", udev_root, udev->name);
filename[sizeof(filename)-1] = '\0';
if (stat(filename, &stats) != 0) {
dbg("device node '%s' not found", filename);
return -1;
}
if (udev->devt && stats.st_rdev != udev->devt) {
info("device node '%s' points to a different device, skip removal", filename);
return -1;
}
info("removing device node '%s'", filename);
retval = unlink_secure(filename);
if (retval)
return retval;
setenv("DEVNAME", filename, 1);
num = udev->partitions;
if (num > 0) {
int i;
info("removing all_partitions '%s[1-%i]'", filename, num);
if (num > 255) {
info("garbage from udev database, skip all_partitions removal");
return -1;
}
for (i = 1; i <= num; i++) {
snprintf(partitionname, sizeof(partitionname), "%s%d", filename, i);
partitionname[sizeof(partitionname)-1] = '\0';
unlink_secure(partitionname);
}
}
if (strchr(udev->name, '/'))
delete_path(filename);
return retval;
}