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/*
* check_desc.c --- Check the group descriptors of an ext2 filesystem
*
* Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Public
* License.
* %End-Header%
*/
#include <stdio.h>
#include <string.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <fcntl.h>
#include <time.h>
#if HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include "ext2_fs.h"
#include "ext2fs.h"
/*
* This routine sanity checks the group descriptors
*/
errcode_t ext2fs_check_desc(ext2_filsys fs)
{
dgrp_t i;
blk_t block = fs->super->s_first_data_block;
blk_t next;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
for (i = 0; i < fs->group_desc_count; i++) {
next = block + fs->super->s_blocks_per_group;
/*
* Check to make sure block bitmap for group is
* located within the group.
*/
if (fs->group_desc[i].bg_block_bitmap < block ||
fs->group_desc[i].bg_block_bitmap >= next)
return EXT2_ET_GDESC_BAD_BLOCK_MAP;
/*
* Check to make sure inode bitmap for group is
* located within the group
*/
if (fs->group_desc[i].bg_inode_bitmap < block ||
fs->group_desc[i].bg_inode_bitmap >= next)
return EXT2_ET_GDESC_BAD_INODE_MAP;
/*
* Check to make sure inode table for group is located
* within the group
*/
if (fs->group_desc[i].bg_inode_table < block ||
((fs->group_desc[i].bg_inode_table +
fs->inode_blocks_per_group) >= next))
return EXT2_ET_GDESC_BAD_INODE_TABLE;
block = next;
}
return 0;
}
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