1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
|
/* vi: set sw=4 ts=4: */
/*
* dirblock.c --- directory block routines.
*
* Copyright (C) 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>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <string.h>
#include <time.h>
#include "ext2_fs.h"
#include "ext2fs.h"
errcode_t ext2fs_read_dir_block2(ext2_filsys fs, blk_t block,
void *buf, int flags EXT2FS_ATTR((unused)))
{
errcode_t retval;
char *p, *end;
struct ext2_dir_entry *dirent;
unsigned int name_len, rec_len;
#if BB_BIG_ENDIAN
unsigned int do_swap;
#endif
retval = io_channel_read_blk(fs->io, block, 1, buf);
if (retval)
return retval;
#if BB_BIG_ENDIAN
do_swap = (fs->flags & (EXT2_FLAG_SWAP_BYTES|
EXT2_FLAG_SWAP_BYTES_READ)) != 0;
#endif
p = (char *) buf;
end = (char *) buf + fs->blocksize;
while (p < end-8) {
dirent = (struct ext2_dir_entry *) p;
#if BB_BIG_ENDIAN
if (do_swap) {
dirent->inode = ext2fs_swab32(dirent->inode);
dirent->rec_len = ext2fs_swab16(dirent->rec_len);
dirent->name_len = ext2fs_swab16(dirent->name_len);
}
#endif
name_len = dirent->name_len;
#ifdef WORDS_BIGENDIAN
if (flags & EXT2_DIRBLOCK_V2_STRUCT)
dirent->name_len = ext2fs_swab16(dirent->name_len);
#endif
rec_len = dirent->rec_len;
if ((rec_len < 8) || (rec_len % 4)) {
rec_len = 8;
retval = EXT2_ET_DIR_CORRUPTED;
}
if (((name_len & 0xFF) + 8) > dirent->rec_len)
retval = EXT2_ET_DIR_CORRUPTED;
p += rec_len;
}
return retval;
}
errcode_t ext2fs_read_dir_block(ext2_filsys fs, blk_t block,
void *buf)
{
return ext2fs_read_dir_block2(fs, block, buf, 0);
}
errcode_t ext2fs_write_dir_block2(ext2_filsys fs, blk_t block,
void *inbuf, int flags EXT2FS_ATTR((unused)))
{
#if BB_BIG_ENDIAN
int do_swap = 0;
errcode_t retval;
char *p, *end;
char *buf = 0;
struct ext2_dir_entry *dirent;
if ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
(fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE))
do_swap = 1;
#ifndef WORDS_BIGENDIAN
if (!do_swap)
return io_channel_write_blk(fs->io, block, 1, (char *) inbuf);
#endif
retval = ext2fs_get_mem(fs->blocksize, &buf);
if (retval)
return retval;
memcpy(buf, inbuf, fs->blocksize);
p = buf;
end = buf + fs->blocksize;
while (p < end) {
dirent = (struct ext2_dir_entry *) p;
if ((dirent->rec_len < 8) ||
(dirent->rec_len % 4)) {
ext2fs_free_mem(&buf);
return EXT2_ET_DIR_CORRUPTED;
}
p += dirent->rec_len;
if (do_swap) {
dirent->inode = ext2fs_swab32(dirent->inode);
dirent->rec_len = ext2fs_swab16(dirent->rec_len);
dirent->name_len = ext2fs_swab16(dirent->name_len);
}
#ifdef WORDS_BIGENDIAN
if (flags & EXT2_DIRBLOCK_V2_STRUCT)
dirent->name_len = ext2fs_swab16(dirent->name_len);
#endif
}
retval = io_channel_write_blk(fs->io, block, 1, buf);
ext2fs_free_mem(&buf);
return retval;
#else
return io_channel_write_blk(fs->io, block, 1, (char *) inbuf);
#endif
}
errcode_t ext2fs_write_dir_block(ext2_filsys fs, blk_t block,
void *inbuf)
{
return ext2fs_write_dir_block2(fs, block, inbuf, 0);
}
|
