udev_add.c revision 821d0ec803a72841f173739f5b713fe847edab75
/*
* udev-add.c
*
* Userspace devfs
*
* Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
*
*
* 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.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <grp.h>
#include <net/if.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <linux/sockios.h>
#include "libsysfs/sysfs/libsysfs.h"
#include "udev_libc_wrapper.h"
#include "udev.h"
#include "udev_utils.h"
#include "udev_sysfs.h"
#include "udev_version.h"
#include "logging.h"
#include "udev_rules.h"
#include "udev_db.h"
#include "udev_selinux.h"
int udev_make_node(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 (stat(file, &stats) != 0)
goto create;
/* preserve node with already correct numbers, to not change the inode number */
if (((stats.st_mode & S_IFMT) == S_IFBLK || (stats.st_mode & S_IFMT) == S_IFCHR) &&
(stats.st_rdev == devt)) {
info("preserve file '%s', cause it has correct dev_t", file);
selinux_setfilecon(file, udev->kernel_name, stats.st_mode);
goto perms;
}
if (unlink(file) != 0)
dbg("unlink(%s) failed with error '%s'", file, strerror(errno));
else
dbg("already present file '%s' unlinked", file);
create:
switch (udev->type) {
case DEV_BLOCK:
mode |= S_IFBLK;
break;
case DEV_CLASS:
mode |= S_IFCHR;
break;
default:
dbg("unknown node type %c\n", udev->type);
return -EINVAL;
}
selinux_setfscreatecon(file, udev->kernel_name, mode);
retval = mknod(file, mode, devt);
selinux_resetfscreatecon();
if (retval != 0) {
err("mknod(%s, %#o, %u, %u) failed with error '%s'",
file, mode, major(devt), minor(devt), strerror(errno));
goto exit;
}
perms:
dbg("chmod(%s, %#o)", file, mode);
if (chmod(file, mode) != 0) {
dbg("chmod(%s, %#o) failed with error '%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) {
dbg("chown(%s, %u, %u) failed with error '%s'",
file, uid, gid, strerror(errno));
goto exit;
}
}
exit:
return retval;
}
static int create_node(struct udevice *udev, struct sysfs_class_device *class_dev)
{
char filename[PATH_SIZE];
char partitionname[PATH_SIZE];
struct name_entry *name_loop;
uid_t uid;
gid_t gid;
int tail;
int i;
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);
}
if (!udev->test_run) {
info("creating device node '%s'", filename);
if (udev_make_node(udev, filename, udev->devt, udev->mode, uid, gid) != 0)
goto error;
} else {
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);
}
/* create all_partitions if requested */
if (udev->partitions) {
struct sysfs_attribute *attr;
int range;
/* take the maximum registered minor range */
attr = sysfs_get_classdev_attr(class_dev, "range");
if (attr) {
range = atoi(attr->value);
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)+1);
udev_make_node(udev, partitionname, part_devt, udev->mode, uid, gid);
}
}
}
/* create symlink(s) if requested */
list_for_each_entry(name_loop, &udev->symlink_list, node) {
int retval;
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));
dbg("symlink(%s, %s)", linktarget, filename);
if (!udev->test_run) {
unlink(filename);
selinux_setfscreatecon(filename, udev->kernel_name, S_IFLNK);
retval = symlink(linktarget, filename);
selinux_resetfscreatecon();
if (retval != 0)
dbg("symlink(%s, %s) failed with error '%s'",
linktarget, filename, strerror(errno));
}
}
return 0;
error:
return -1;
}
static int rename_net_if(struct udevice *udev)
{
int sk;
struct ifreq ifr;
int retval;
info("changing net interface name from '%s' to '%s'", udev->kernel_name, udev->name);
if (udev->test_run)
return 0;
sk = socket(PF_INET, SOCK_DGRAM, 0);
if (sk < 0) {
dbg("error opening socket");
return -1;
}
memset(&ifr, 0x00, sizeof(struct ifreq));
strlcpy(ifr.ifr_name, udev->kernel_name, IFNAMSIZ);
strlcpy(ifr.ifr_newname, udev->name, IFNAMSIZ);
retval = ioctl(sk, SIOCSIFNAME, &ifr);
if (retval != 0)
dbg("error changing net interface name");
close(sk);
return retval;
}
int udev_add_device(struct udevice *udev, struct sysfs_class_device *class_dev)
{
char *pos;
int retval = 0;
if (udev->type == DEV_BLOCK || udev->type == DEV_CLASS) {
udev->devt = get_devt(class_dev);
if (!udev->devt) {
dbg("no dev-file found, do nothing");
return 0;
}
}
udev_rules_get_name(udev, class_dev);
if (udev->ignore_device) {
dbg("device event will be ignored");
return 0;
}
dbg("adding name='%s'", udev->name);
selinux_init();
if (udev->type == DEV_BLOCK || udev->type == DEV_CLASS) {
retval = create_node(udev, class_dev);
if (retval != 0)
goto exit;
if (udev_db_add_device(udev) != 0)
dbg("udev_db_add_dev failed, but we create the node anyway, "
"remove might not work for custom names");
/* use full path to the environment */
snprintf(udev->devname, sizeof(udev->devname), "%s/%s", udev_root, udev->name);
udev->devname[sizeof(udev->devname)-1] = '\0';
} else if (udev->type == DEV_NET) {
/* look if we want to change the name of the netif */
if (strcmp(udev->name, udev->kernel_name) != 0) {
retval = rename_net_if(udev);
if (retval != 0)
goto exit;
/* we've changed the name, now fake the devpath, cause the
* original kernel name sleeps with the fishes and we don't
* get an event from the kernel with the new name
*/
pos = strrchr(udev->devpath, '/');
if (pos != NULL) {
pos[1] = '\0';
strlcat(udev->devpath, udev->name, sizeof(udev->devpath));
setenv("DEVPATH", udev->devpath, 1);
setenv("INTERFACE", udev->name, 1);
}
/* use netif name for the environment */
strlcpy(udev->devname, udev->name, sizeof(udev->devname));
}
}
exit:
selinux_exit();
return retval;
}