dirblock.c revision 65f0aab98b20b5994a726ab90d355248bcddfffd 
1/*
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 <stdio.h>
13#if HAVE_UNISTD_H
14#include <unistd.h>
15#endif
16#include <string.h>
17#include <time.h>
18
19#include "ext2_fs.h"
20#include "ext2fs.h"
21
22errcode_t ext2fs_read_dir_block2(ext2_filsys fs, blk_t block,
23				 void *buf, int flags EXT2FS_ATTR((unused)))
24{
25	errcode_t	retval;
26	char		*p, *end;
27	struct ext2_dir_entry *dirent;
28	unsigned int	name_len, rec_len;
29
30
31 	retval = io_channel_read_blk(fs->io, block, 1, buf);
32	if (retval)
33		return retval;
34
35	p = (char *) buf;
36	end = (char *) buf + fs->blocksize;
37	while (p < end-8) {
38		dirent = (struct ext2_dir_entry *) p;
39#ifdef WORDS_BIGENDIAN
40		dirent->inode = ext2fs_swab32(dirent->inode);
41		dirent->rec_len = ext2fs_swab16(dirent->rec_len);
42		dirent->name_len = ext2fs_swab16(dirent->name_len);
43#endif
44		name_len = dirent->name_len;
45#ifdef WORDS_BIGENDIAN
46		if (flags & EXT2_DIRBLOCK_V2_STRUCT)
47			dirent->name_len = ext2fs_swab16(dirent->name_len);
48#endif
49		if ((retval = ext2fs_get_rec_len(fs, dirent, &rec_len)) != 0)
50			return retval;
51		if ((rec_len < 8) || (rec_len % 4)) {
52			rec_len = 8;
53			retval = EXT2_ET_DIR_CORRUPTED;
54		} else if (((name_len & 0xFF) + 8) > rec_len)
55			retval = EXT2_ET_DIR_CORRUPTED;
56		p += rec_len;
57	}
58	return retval;
59}
60
61errcode_t ext2fs_read_dir_block(ext2_filsys fs, blk_t block,
62				 void *buf)
63{
64	return ext2fs_read_dir_block2(fs, block, buf, 0);
65}
66
67
68errcode_t ext2fs_write_dir_block2(ext2_filsys fs, blk_t block,
69				  void *inbuf, int flags EXT2FS_ATTR((unused)))
70{
71#ifdef WORDS_BIGENDIAN
72	errcode_t	retval;
73	char		*p, *end;
74	char		*buf = 0;
75	unsigned int	rec_len;
76	struct ext2_dir_entry *dirent;
77
78	retval = ext2fs_get_mem(fs->blocksize, &buf);
79	if (retval)
80		return retval;
81	memcpy(buf, inbuf, fs->blocksize);
82	p = buf;
83	end = buf + fs->blocksize;
84	while (p < end) {
85		dirent = (struct ext2_dir_entry *) p;
86		if ((retval = ext2fs_get_rec_len(fs, dirent, &rec_len)) != 0)
87			return retval;
88		if ((rec_len < 8) ||
89		    (rec_len % 4)) {
90			ext2fs_free_mem(&buf);
91			return (EXT2_ET_DIR_CORRUPTED);
92		}
93		p += rec_len;
94		dirent->inode = ext2fs_swab32(dirent->inode);
95		dirent->rec_len = ext2fs_swab16(dirent->rec_len);
96		dirent->name_len = ext2fs_swab16(dirent->name_len);
97
98		if (flags & EXT2_DIRBLOCK_V2_STRUCT)
99			dirent->name_len = ext2fs_swab16(dirent->name_len);
100	}
101 	retval = io_channel_write_blk(fs->io, block, 1, buf);
102	ext2fs_free_mem(&buf);
103	return retval;
104#else
105 	return io_channel_write_blk(fs->io, block, 1, (char *) inbuf);
106#endif
107}
108
109
110errcode_t ext2fs_write_dir_block(ext2_filsys fs, blk_t block,
111				 void *inbuf)
112{
113	return ext2fs_write_dir_block2(fs, block, inbuf, 0);
114}
115
116