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/*
* udev-remove.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 <stddef.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <sys/stat.h>
#include "udev.h"
#include "udev_lib.h"
#include "udev_version.h"
#include "logging.h"
#include "namedev.h"
#include "udevdb.h"
static int delete_path(const char *path)
{
char *pos;
int retval;
pos = strrchr(path, '/');
while (1) {
*pos = '\0';
pos = strrchr(path, '/');
/* don't remove the last one */
if ((pos == path) || (pos == NULL))
break;
/* remove if empty */
retval = rmdir(path);
if (errno == ENOENT)
retval = 0;
if (retval) {
if (errno == ENOTEMPTY)
return 0;
dbg("rmdir(%s) failed with error '%s'",
path, strerror(errno));
break;
}
dbg("removed '%s'", path);
}
return 0;
}
/** Remove all permissions on the device node, before
* unlinking it. This fixes a security issue.
* If the user created a hard-link to the device node,
* he can't use it any longer, because he lost permission
* to do so.
*/
static int secure_unlink(const char *filename)
{
int retval;
retval = chown(filename, 0, 0);
if (retval) {
dbg("chown(%s, 0, 0) failed with error '%s'",
filename, strerror(errno));
/* We continue nevertheless.
* I think it's very unlikely for chown
* to fail here, if the file exists.
*/
}
retval = chmod(filename, 0000);
if (retval) {
dbg("chmod(%s, 0000) failed with error '%s'",
filename, strerror(errno));
/* We continue nevertheless. */
}
retval = unlink(filename);
if (errno == ENOENT)
retval = 0;
if (retval) {
dbg("unlink(%s) failed with error '%s'",
filename, strerror(errno));
}
return retval;
}
static int delete_node(struct udevice *udev)
{
char filename[NAME_SIZE];
char partitionname[NAME_SIZE];
int retval;
int i;
char *pos;
int len;
int num;
snprintf(filename, NAME_SIZE, "%s/%s", udev_root, udev->name);
filename[NAME_SIZE-1] = '\0';
info("removing device node '%s'", filename);
retval = secure_unlink(filename);
if (retval)
return retval;
/* remove all_partitions nodes */
num = udev->partitions;
if (num > 0) {
info("removing all_partitions '%s[1-%i]'", filename, num);
if (num > PARTITIONS_COUNT) {
info("garbage from udev database, skip all_partitions removal");
return -1;
}
for (i = 1; i <= num; i++) {
strfieldcpy(partitionname, filename);
strintcat(partitionname, i);
secure_unlink(partitionname);
}
}
/* remove subdirectories */
if (strchr(udev->name, '/'))
delete_path(filename);
foreach_strpart(udev->symlink, " ", pos, len) {
char linkname[NAME_SIZE];
strfieldcpymax(linkname, pos, len+1);
snprintf(filename, NAME_SIZE, "%s/%s", udev_root, linkname);
filename[NAME_SIZE-1] = '\0';
dbg("unlinking symlink '%s'", filename);
retval = unlink(filename);
if (errno == ENOENT)
retval = 0;
if (retval) {
dbg("unlink(%s) failed with error '%s'",
filename, strerror(errno));
return retval;
}
if (strchr(udev->symlink, '/')) {
delete_path(filename);
}
}
return retval;
}
/*
* look up the sysfs path in the database to get the node name to remove
* If we can't find it, use kernel name for lack of anything else to know to do
*/
int udev_remove_device(struct udevice *udev)
{
const char *temp;
int retval;
if (udev->type != 'b' && udev->type != 'c')
return 0;
retval = udevdb_get_dev(udev);
if (retval) {
/* fall back to kernel name */
temp = strrchr(udev->devpath, '/');
if (temp == NULL)
return -ENODEV;
strfieldcpy(udev->name, &temp[1]);
dbg("'%s' not found in database, falling back on default name", udev->name);
}
dbg("remove name='%s'", udev->name);
udevdb_delete_dev(udev);
/* use full path to the environment */
snprintf(udev->devname, NAME_SIZE, "%s/%s", udev_root, udev->name);
return delete_node(udev);
}
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