dosfs.h revision 1.6 
1/*	$OpenBSD: dosfs.h,v 1.6 2014/06/16 18:33:33 tobias Exp $	*/
2/*	$NetBSD: dosfs.h,v 1.5 1997/10/17 11:19:41 ws Exp $	*/
3
4/*
5 * Copyright (C) 1995, 1996, 1997 Wolfgang Solfrank
6 * Copyright (c) 1995 Martin Husemann
7 * Some structure declaration borrowed from Paul Popelka
8 * (paulp@uts.amdahl.com), see /sys/msdosfs/ for reference.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#ifndef DOSFS_H
32#define DOSFS_H
33
34#define DOSBOOTBLOCKSIZE 512
35
36typedef	u_int32_t	cl_t;	/* type holding a cluster number */
37
38/*
39 * architecture independent description of all the info stored in a
40 * FAT boot block.
41 */
42struct bootblock {
43	u_int	BytesPerSec;		/* bytes per sector */
44	u_int	SecPerClust;		/* sectors per cluster */
45	u_int	ResSectors;		/* number of reserved sectors */
46	u_int	FATs;			/* number of FATs */
47	u_int	RootDirEnts;		/* number of root directory entries */
48	u_int	Media;			/* media descriptor */
49	u_int	FATsmall;		/* number of sectors per FAT */
50	u_int	SecPerTrack;		/* sectors per track */
51	u_int	Heads;			/* number of heads */
52	u_int32_t Sectors;		/* total number of sectors */
53	u_int32_t HiddenSecs;		/* # of hidden sectors */
54	u_int32_t HugeSectors;		/* # of sectors if bpbSectors == 0 */
55	u_int	FSInfo;			/* FSInfo sector */
56	u_int	Backup;			/* Backup of Bootblocks */
57	cl_t	RootCl;			/* Start of Root Directory */
58	cl_t	FSFree;			/* Number of free clusters acc. FSInfo */
59	cl_t	FSNext;			/* Next free cluster acc. FSInfo */
60
61	/* and some more calculated values */
62	u_int	flags;			/* some flags: */
63#define	FAT32		1		/* this is a FAT32 filesystem */
64					/*
65					 * Maybe, we should separate out
66					 * various parts of FAT32?	XXX
67					 */
68	int	ValidFat;		/* valid fat if FAT32 non-mirrored */
69	cl_t	ClustMask;		/* mask for entries in FAT */
70	cl_t	NumClusters;		/* # of entries in a FAT */
71	u_int32_t NumSectors;		/* how many sectors are there */
72	u_int32_t FATsecs;		/* how many sectors are in FAT */
73	u_int32_t NumFatEntries;	/* how many entries really are there */
74	u_int	ClusterOffset;		/* at what sector would sector 0 start */
75	u_int	ClusterSize;		/* Cluster size in bytes */
76
77	/* Now some statistics: */
78	u_int	NumFiles;		/* # of plain files */
79	u_int	NumFree;		/* # of free clusters */
80	u_int	NumBad;			/* # of bad clusters */
81};
82
83struct fatEntry {
84	cl_t	next;			/* pointer to next cluster */
85	cl_t	head;			/* pointer to start of chain */
86	u_int32_t length;		/* number of clusters on chain */
87	int	flags;			/* see below */
88};
89
90#define	CLUST_FREE	0		/* 0 means cluster is free */
91#define	CLUST_FIRST	2		/* 2 is the minimum valid cluster number */
92#define	CLUST_RSRVD	0xfffffff6	/* start of reserved clusters */
93#define	CLUST_BAD	0xfffffff7	/* a cluster with a defect */
94#define	CLUST_EOFS	0xfffffff8	/* start of EOF indicators */
95#define	CLUST_EOF	0xffffffff	/* standard value for last cluster */
96
97/*
98 * Masks for cluster values
99 */
100#define	CLUST12_MASK	0xfff
101#define	CLUST16_MASK	0xffff
102#define	CLUST32_MASK	0xfffffff
103
104#define	FAT_USED	1		/* This fat chain is used in a file */
105
106#define	DOSLONGNAMELEN	256		/* long name maximal length */
107#define LRFIRST		0x40		/* first long name record */
108#define	LRNOMASK	0x1f		/* mask to extract long record
109					 * sequence number */
110
111/*
112 * Architecture independent description of a directory entry
113 */
114struct dosDirEntry {
115	struct dosDirEntry
116		*parent,		/* previous tree level */
117		*next,			/* next brother */
118		*child;			/* if this is a directory */
119	char name[8+1+3+1];		/* alias name first part */
120	char lname[DOSLONGNAMELEN];	/* real name */
121	uint flags;			/* attributes */
122	cl_t head;			/* cluster no */
123	u_int32_t size;			/* filesize in bytes */
124	uint fsckflags;			/* flags during fsck */
125};
126/* Flags in fsckflags: */
127#define	DIREMPTY	1
128#define	DIREMPWARN	2
129
130/*
131 *  TODO-list of unread directories
132 */
133struct dirTodoNode {
134	struct dosDirEntry *dir;
135	struct dirTodoNode *next;
136};
137
138#endif
139