blob: cb3a104c781854fe3575484a98d338a8e89016b4 [file] [log] [blame]
lh9ed821d2023-04-07 01:36:19 -07001/*
2 * dirblock.c --- directory block routines.
3 *
4 * Copyright (C) 1995, 1996 Theodore Ts'o.
5 *
6 * %Begin-Header%
7 * This file may be redistributed under the terms of the GNU Library
8 * General Public License, version 2.
9 * %End-Header%
10 */
11
12#include "config.h"
13#include <stdio.h>
14#if HAVE_UNISTD_H
15#include <unistd.h>
16#endif
17#include <string.h>
18#include <time.h>
19
20#include "ext2_fs.h"
21#include "ext2fs.h"
22
23errcode_t ext2fs_read_dir_block3(ext2_filsys fs, blk64_t block,
24 void *buf, int flags EXT2FS_ATTR((unused)))
25{
26 errcode_t retval;
27 char *p, *end;
28 struct ext2_dir_entry *dirent;
29 unsigned int name_len, rec_len;
30
31
32 retval = io_channel_read_blk64(fs->io, block, 1, buf);
33 if (retval)
34 return retval;
35
36 p = (char *) buf;
37 end = (char *) buf + fs->blocksize;
38 while (p < end-8) {
39 dirent = (struct ext2_dir_entry *) p;
40#ifdef WORDS_BIGENDIAN
41 dirent->inode = ext2fs_swab32(dirent->inode);
42 dirent->rec_len = ext2fs_swab16(dirent->rec_len);
43 dirent->name_len = ext2fs_swab16(dirent->name_len);
44#endif
45 name_len = dirent->name_len;
46#ifdef WORDS_BIGENDIAN
47 if (flags & EXT2_DIRBLOCK_V2_STRUCT)
48 dirent->name_len = ext2fs_swab16(dirent->name_len);
49#endif
50 if ((retval = ext2fs_get_rec_len(fs, dirent, &rec_len)) != 0)
51 return retval;
52 if ((rec_len < 8) || (rec_len % 4)) {
53 rec_len = 8;
54 retval = EXT2_ET_DIR_CORRUPTED;
55 } else if (((name_len & 0xFF) + 8) > rec_len)
56 retval = EXT2_ET_DIR_CORRUPTED;
57 p += rec_len;
58 }
59 return retval;
60}
61
62errcode_t ext2fs_read_dir_block2(ext2_filsys fs, blk_t block,
63 void *buf, int flags EXT2FS_ATTR((unused)))
64{
65 return ext2fs_read_dir_block3(fs, block, buf, flags);
66}
67
68errcode_t ext2fs_read_dir_block(ext2_filsys fs, blk_t block,
69 void *buf)
70{
71 return ext2fs_read_dir_block3(fs, block, buf, 0);
72}
73
74
75errcode_t ext2fs_write_dir_block3(ext2_filsys fs, blk64_t block,
76 void *inbuf, int flags EXT2FS_ATTR((unused)))
77{
78#ifdef WORDS_BIGENDIAN
79 errcode_t retval;
80 char *p, *end;
81 char *buf = 0;
82 unsigned int rec_len;
83 struct ext2_dir_entry *dirent;
84
85 retval = ext2fs_get_mem(fs->blocksize, &buf);
86 if (retval)
87 return retval;
88 memcpy(buf, inbuf, fs->blocksize);
89 p = buf;
90 end = buf + fs->blocksize;
91 while (p < end) {
92 dirent = (struct ext2_dir_entry *) p;
93 if ((retval = ext2fs_get_rec_len(fs, dirent, &rec_len)) != 0)
94 return retval;
95 if ((rec_len < 8) ||
96 (rec_len % 4)) {
97 ext2fs_free_mem(&buf);
98 return (EXT2_ET_DIR_CORRUPTED);
99 }
100 p += rec_len;
101 dirent->inode = ext2fs_swab32(dirent->inode);
102 dirent->rec_len = ext2fs_swab16(dirent->rec_len);
103 dirent->name_len = ext2fs_swab16(dirent->name_len);
104
105 if (flags & EXT2_DIRBLOCK_V2_STRUCT)
106 dirent->name_len = ext2fs_swab16(dirent->name_len);
107 }
108 retval = io_channel_write_blk64(fs->io, block, 1, buf);
109 ext2fs_free_mem(&buf);
110 return retval;
111#else
112 return io_channel_write_blk64(fs->io, block, 1, (char *) inbuf);
113#endif
114}
115
116errcode_t ext2fs_write_dir_block2(ext2_filsys fs, blk_t block,
117 void *inbuf, int flags EXT2FS_ATTR((unused)))
118{
119 return ext2fs_write_dir_block3(fs, block, inbuf, flags);
120}
121
122errcode_t ext2fs_write_dir_block(ext2_filsys fs, blk_t block,
123 void *inbuf)
124{
125 return ext2fs_write_dir_block3(fs, block, inbuf, 0);
126}
127