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
ext2fs_read_dir_block2(ext2_filsys fs,blk_t block,void * buf,int flags EXT2FS_ATTR ((unused)))22 errcode_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
ext2fs_read_dir_block(ext2_filsys fs,blk_t block,void * buf)61 errcode_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
ext2fs_write_dir_block2(ext2_filsys fs,blk_t block,void * inbuf,int flags EXT2FS_ATTR ((unused)))68 errcode_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
ext2fs_write_dir_block(ext2_filsys fs,blk_t block,void * inbuf)110 errcode_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