1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2009 Aditya Sarawgi
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#ifndef _FS_EXT2FS_EXT2_DIR_H_
30#define	_FS_EXT2FS_EXT2_DIR_H_
31
32/*
33 * Structure of a directory entry
34 */
35#define	EXT2FS_MAXNAMLEN	255
36
37struct ext2fs_direct {
38	uint32_t e2d_ino;		/* inode number of entry */
39	uint16_t e2d_reclen;		/* length of this record */
40	uint16_t e2d_namlen;		/* length of string in e2d_name */
41	char e2d_name[EXT2FS_MAXNAMLEN];/* name with length<=EXT2FS_MAXNAMLEN */
42};
43
44enum slotstatus {
45	NONE,
46	COMPACT,
47	FOUND
48};
49
50struct ext2fs_searchslot {
51	enum slotstatus slotstatus;
52	doff_t	slotoffset;		/* offset of area with free space */
53	int	slotsize;		/* size of area at slotoffset */
54	int	slotfreespace;		/* amount of space free in slot */
55	int	slotneeded;		/* sizeof the entry we are seeking */
56};
57
58/*
59 * The new version of the directory entry.  Since EXT2 structures are
60 * stored in intel byte order, and the name_len field could never be
61 * bigger than 255 chars, it's safe to reclaim the extra byte for the
62 * file_type field.
63 */
64struct ext2fs_direct_2 {
65	uint32_t e2d_ino;		/* inode number of entry */
66	uint16_t e2d_reclen;		/* length of this record */
67	uint8_t	e2d_namlen;		/* length of string in e2d_name */
68	uint8_t	e2d_type;		/* file type */
69	char	e2d_name[EXT2FS_MAXNAMLEN];	/* name with
70						 * length<=EXT2FS_MAXNAMLEN */
71};
72
73struct ext2fs_direct_tail {
74	uint32_t e2dt_reserved_zero1;	/* pretend to be unused */
75	uint16_t e2dt_rec_len;		/* 12 */
76	uint8_t	e2dt_reserved_zero2;	/* zero name length */
77	uint8_t	e2dt_reserved_ft;	/* 0xDE, fake file type */
78	uint32_t e2dt_checksum;		/* crc32c(uuid+inum+dirblock) */
79};
80
81#define EXT2_FT_DIR_CSUM	0xDE
82
83#define EXT2_DIRENT_TAIL(data, blocksize) \
84	((struct ext2fs_direct_tail *)(((char *)(data)) + \
85	(blocksize) - sizeof(struct ext2fs_direct_tail)))
86
87/*
88 * Maximal count of links to a file
89 */
90#define	EXT4_LINK_MAX	65000
91
92/*
93 * Ext2 directory file types.  Only the low 3 bits are used.  The
94 * other bits are reserved for now.
95 */
96#define	EXT2_FT_UNKNOWN		0
97#define	EXT2_FT_REG_FILE	1
98#define	EXT2_FT_DIR		2
99#define	EXT2_FT_CHRDEV		3
100#define	EXT2_FT_BLKDEV 		4
101#define	EXT2_FT_FIFO		5
102#define	EXT2_FT_SOCK		6
103#define	EXT2_FT_SYMLINK		7
104#define	EXT2_FT_MAX		8
105
106/*
107 * EXT2_DIR_PAD defines the directory entries boundaries
108 *
109 * NOTE: It must be a multiple of 4
110 */
111#define	EXT2_DIR_PAD		 	4
112#define	EXT2_DIR_ROUND			(EXT2_DIR_PAD - 1)
113#define	EXT2_DIR_REC_LEN(name_len)	(((name_len) + 8 + EXT2_DIR_ROUND) & \
114					 ~EXT2_DIR_ROUND)
115#endif	/* !_FS_EXT2FS_EXT2_DIR_H_ */
116