/* * 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; }