HardenedBSD/usr.sbin/fstyp/ext2fs.c
Edward Tomasz Napierala b43dc82c6b Fix detection of ext2/ext3 filesystems that lack labels.
MFC after:	1 month
Sponsored by:	The FreeBSD Foundation
2015-01-13 13:59:48 +00:00

86 lines
2.5 KiB
C

/*-
* Copyright (c) 2005 Stanislav Sedov
* Copyright (c) 2014 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Edward Tomasz Napierala under sponsorship
* from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include "fstyp.h"
#define EXT2FS_SB_OFFSET 1024
#define EXT2_SUPER_MAGIC 0xef53
#define EXT2_DYNAMIC_REV 1
typedef struct e2sb {
uint8_t fake1[56];
uint16_t s_magic;
uint8_t fake2[18];
uint32_t s_rev_level;
uint8_t fake3[40];
char s_volume_name[16];
} e2sb_t;
int
fstyp_ext2fs(FILE *fp, char *label, size_t size)
{
e2sb_t *fs;
char *s_volume_name;
fs = (e2sb_t *)read_buf(fp, EXT2FS_SB_OFFSET, 512);
if (fs == NULL)
return (1);
/* Check for magic and versio n*/
if (fs->s_magic == EXT2_SUPER_MAGIC &&
fs->s_rev_level == EXT2_DYNAMIC_REV) {
//G_LABEL_DEBUG(1, "ext2fs file system detected on %s.",
// pp->name);
} else {
free(fs);
return (1);
}
s_volume_name = fs->s_volume_name;
/* Terminate label */
s_volume_name[sizeof(fs->s_volume_name) - 1] = '\0';
if (s_volume_name[0] == '/')
s_volume_name += 1;
strlcpy(label, s_volume_name, size);
free(fs);
return (0);
}