blob: f9c5a104b01fd155ec2de57a66382635337ff164
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * dirblock.c --- directory block routines. |
4 | * |
5 | * Copyright (C) 1995, 1996 Theodore Ts'o. |
6 | * |
7 | * %Begin-Header% |
8 | * This file may be redistributed under the terms of the GNU Public |
9 | * License. |
10 | * %End-Header% |
11 | */ |
12 | |
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 | |
23 | errcode_t ext2fs_read_dir_block2(ext2_filsys fs, blk_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 | #if BB_BIG_ENDIAN |
31 | unsigned int do_swap; |
32 | #endif |
33 | |
34 | retval = io_channel_read_blk(fs->io, block, 1, buf); |
35 | if (retval) |
36 | return retval; |
37 | #if BB_BIG_ENDIAN |
38 | do_swap = (fs->flags & (EXT2_FLAG_SWAP_BYTES| |
39 | EXT2_FLAG_SWAP_BYTES_READ)) != 0; |
40 | #endif |
41 | p = (char *) buf; |
42 | end = (char *) buf + fs->blocksize; |
43 | while (p < end-8) { |
44 | dirent = (struct ext2_dir_entry *) p; |
45 | #if BB_BIG_ENDIAN |
46 | if (do_swap) { |
47 | dirent->inode = ext2fs_swab32(dirent->inode); |
48 | dirent->rec_len = ext2fs_swab16(dirent->rec_len); |
49 | dirent->name_len = ext2fs_swab16(dirent->name_len); |
50 | } |
51 | #endif |
52 | name_len = dirent->name_len; |
53 | #ifdef WORDS_BIGENDIAN |
54 | if (flags & EXT2_DIRBLOCK_V2_STRUCT) |
55 | dirent->name_len = ext2fs_swab16(dirent->name_len); |
56 | #endif |
57 | rec_len = dirent->rec_len; |
58 | if ((rec_len < 8) || (rec_len % 4)) { |
59 | rec_len = 8; |
60 | retval = EXT2_ET_DIR_CORRUPTED; |
61 | } |
62 | if (((name_len & 0xFF) + 8) > dirent->rec_len) |
63 | retval = EXT2_ET_DIR_CORRUPTED; |
64 | p += rec_len; |
65 | } |
66 | return retval; |
67 | } |
68 | |
69 | errcode_t ext2fs_read_dir_block(ext2_filsys fs, blk_t block, |
70 | void *buf) |
71 | { |
72 | return ext2fs_read_dir_block2(fs, block, buf, 0); |
73 | } |
74 | |
75 | |
76 | errcode_t ext2fs_write_dir_block2(ext2_filsys fs, blk_t block, |
77 | void *inbuf, int flags EXT2FS_ATTR((unused))) |
78 | { |
79 | #if BB_BIG_ENDIAN |
80 | int do_swap = 0; |
81 | errcode_t retval; |
82 | char *p, *end; |
83 | char *buf = NULL; |
84 | struct ext2_dir_entry *dirent; |
85 | |
86 | if ((fs->flags & EXT2_FLAG_SWAP_BYTES) || |
87 | (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE)) |
88 | do_swap = 1; |
89 | |
90 | #ifndef WORDS_BIGENDIAN |
91 | if (!do_swap) |
92 | return io_channel_write_blk(fs->io, block, 1, (char *) inbuf); |
93 | #endif |
94 | |
95 | retval = ext2fs_get_mem(fs->blocksize, &buf); |
96 | if (retval) |
97 | return retval; |
98 | memcpy(buf, inbuf, fs->blocksize); |
99 | p = buf; |
100 | end = buf + fs->blocksize; |
101 | while (p < end) { |
102 | dirent = (struct ext2_dir_entry *) p; |
103 | if ((dirent->rec_len < 8) || |
104 | (dirent->rec_len % 4)) { |
105 | ext2fs_free_mem(&buf); |
106 | return EXT2_ET_DIR_CORRUPTED; |
107 | } |
108 | p += dirent->rec_len; |
109 | if (do_swap) { |
110 | dirent->inode = ext2fs_swab32(dirent->inode); |
111 | dirent->rec_len = ext2fs_swab16(dirent->rec_len); |
112 | dirent->name_len = ext2fs_swab16(dirent->name_len); |
113 | } |
114 | #ifdef WORDS_BIGENDIAN |
115 | if (flags & EXT2_DIRBLOCK_V2_STRUCT) |
116 | dirent->name_len = ext2fs_swab16(dirent->name_len); |
117 | #endif |
118 | } |
119 | retval = io_channel_write_blk(fs->io, block, 1, buf); |
120 | ext2fs_free_mem(&buf); |
121 | return retval; |
122 | #else |
123 | return io_channel_write_blk(fs->io, block, 1, (char *) inbuf); |
124 | #endif |
125 | } |
126 | |
127 | |
128 | errcode_t ext2fs_write_dir_block(ext2_filsys fs, blk_t block, |
129 | void *inbuf) |
130 | { |
131 | return ext2fs_write_dir_block2(fs, block, inbuf, 0); |
132 | } |
133 |