1 /* 2 * check_desc.c --- Check the group descriptors of an ext2 filesystem 3 * 4 * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o. 5 * 6 * %Begin-Header% 7 * This file may be redistributed under the terms of the GNU Public 8 * License. 9 * %End-Header% 10 */ 11 12 #include <stdio.h> 13 #include <string.h> 14 #if HAVE_UNISTD_H 15 #include <unistd.h> 16 #endif 17 #include <fcntl.h> 18 #include <time.h> 19 #if HAVE_SYS_STAT_H 20 #include <sys/stat.h> 21 #endif 22 #if HAVE_SYS_TYPES_H 23 #include <sys/types.h> 24 #endif 25 26 #include "ext2_fs.h" 27 #include "ext2fs.h" 28 29 /* 30 * This routine sanity checks the group descriptors 31 */ 32 errcode_t ext2fs_check_desc(ext2_filsys fs) 33 { 34 dgrp_t i; 35 blk_t first_block = fs->super->s_first_data_block; 36 blk_t last_block; 37 38 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); 39 40 for (i = 0; i < fs->group_desc_count; i++) { 41 first_block = ext2fs_group_first_block(fs, i); 42 last_block = ext2fs_group_last_block(fs, i); 43 44 /* 45 * Check to make sure block bitmap for group is 46 * located within the group. 47 */ 48 if (fs->group_desc[i].bg_block_bitmap < first_block || 49 fs->group_desc[i].bg_block_bitmap > last_block) 50 return EXT2_ET_GDESC_BAD_BLOCK_MAP; 51 /* 52 * Check to make sure inode bitmap for group is 53 * located within the group 54 */ 55 if (fs->group_desc[i].bg_inode_bitmap < first_block || 56 fs->group_desc[i].bg_inode_bitmap > last_block) 57 return EXT2_ET_GDESC_BAD_INODE_MAP; 58 /* 59 * Check to make sure inode table for group is located 60 * within the group 61 */ 62 if (fs->group_desc[i].bg_inode_table < first_block || 63 ((fs->group_desc[i].bg_inode_table + 64 fs->inode_blocks_per_group - 1) > last_block)) 65 return EXT2_ET_GDESC_BAD_INODE_TABLE; 66 } 67 return 0; 68 } 69
