blob: dd4b0e9cf5df18e47f0752588bf6eb250416d245
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * check_desc.c --- Check the group descriptors of an ext2 filesystem |
4 | * |
5 | * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o. |
6 | * |
7 | * %Begin-Header% |
8 | * This file may be redistributed under the terms of the GNU Public |
9 | * License. |
10 | * %End-Header% |
11 | */ |
12 | |
13 | #include <stdio.h> |
14 | #include <string.h> |
15 | #if HAVE_UNISTD_H |
16 | #include <unistd.h> |
17 | #endif |
18 | #include <fcntl.h> |
19 | #include <time.h> |
20 | #if HAVE_SYS_STAT_H |
21 | #include <sys/stat.h> |
22 | #endif |
23 | #if HAVE_SYS_TYPES_H |
24 | #include <sys/types.h> |
25 | #endif |
26 | |
27 | #include "ext2_fs.h" |
28 | #include "ext2fs.h" |
29 | |
30 | /* |
31 | * This routine sanity checks the group descriptors |
32 | */ |
33 | errcode_t ext2fs_check_desc(ext2_filsys fs) |
34 | { |
35 | dgrp_t i; |
36 | blk_t block = fs->super->s_first_data_block; |
37 | blk_t next; |
38 | |
39 | EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); |
40 | |
41 | for (i = 0; i < fs->group_desc_count; i++) { |
42 | next = block + fs->super->s_blocks_per_group; |
43 | /* |
44 | * Check to make sure block bitmap for group is |
45 | * located within the group. |
46 | */ |
47 | if (fs->group_desc[i].bg_block_bitmap < block || |
48 | fs->group_desc[i].bg_block_bitmap >= next) |
49 | return EXT2_ET_GDESC_BAD_BLOCK_MAP; |
50 | /* |
51 | * Check to make sure inode bitmap for group is |
52 | * located within the group |
53 | */ |
54 | if (fs->group_desc[i].bg_inode_bitmap < block || |
55 | fs->group_desc[i].bg_inode_bitmap >= next) |
56 | return EXT2_ET_GDESC_BAD_INODE_MAP; |
57 | /* |
58 | * Check to make sure inode table for group is located |
59 | * within the group |
60 | */ |
61 | if (fs->group_desc[i].bg_inode_table < block || |
62 | ((fs->group_desc[i].bg_inode_table + |
63 | fs->inode_blocks_per_group) >= next)) |
64 | return EXT2_ET_GDESC_BAD_INODE_TABLE; |
65 | |
66 | block = next; |
67 | } |
68 | return 0; |
69 | } |
70 |