dirblock.c revision 126a291c768b523bc228b276d3bea82675a86d09 
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 Public
8 * License.
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		rec_len = dirent->rec_len;
50		if ((rec_len < 8) || (rec_len % 4)) {
51			rec_len = 8;
52			retval = EXT2_ET_DIR_CORRUPTED;
53		}
54		if (((name_len & 0xFF) + 8) > dirent->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	struct ext2_dir_entry *dirent;
76
77	retval = ext2fs_get_mem(fs->blocksize, &buf);
78	if (retval)
79		return retval;
80	memcpy(buf, inbuf, fs->blocksize);
81	p = buf;
82	end = buf + fs->blocksize;
83	while (p < end) {
84		dirent = (struct ext2_dir_entry *) p;
85		if ((dirent->rec_len < 8) ||
86		    (dirent->rec_len % 4)) {
87			ext2fs_free_mem(&buf);
88			return (EXT2_ET_DIR_CORRUPTED);
89		}
90		p += dirent->rec_len;
91		dirent->inode = ext2fs_swab32(dirent->inode);
92		dirent->rec_len = ext2fs_swab16(dirent->rec_len);
93		dirent->name_len = ext2fs_swab16(dirent->name_len);
94
95		if (flags & EXT2_DIRBLOCK_V2_STRUCT)
96			dirent->name_len = ext2fs_swab16(dirent->name_len);
97	}
98 	retval = io_channel_write_blk(fs->io, block, 1, buf);
99	ext2fs_free_mem(&buf);
100	return retval;
101#else
102 	return io_channel_write_blk(fs->io, block, 1, (char *) inbuf);
103#endif
104}
105
106
107errcode_t ext2fs_write_dir_block(ext2_filsys fs, blk_t block,
108				 void *inbuf)
109{
110	return ext2fs_write_dir_block2(fs, block, inbuf, 0);
111}
112
113