1
2/*
3 * Mach Operating System
4 * Copyright (c) 1991,1990 Carnegie Mellon University
5 * All Rights Reserved.
6 *
7 * Permission to use, copy, modify and distribute this software and its
8 * documentation is hereby granted, provided that both the copyright
9 * notice and this permission notice appear in all copies of the
10 * software, derivative works or modified versions, and any portions
11 * thereof, and that both notices appear in supporting documentation.
12 *
13 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
14 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
15 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
16 *
17 * Carnegie Mellon requests users of this software to return to
18 *
19 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
20 *  School of Computer Science
21 *  Carnegie Mellon University
22 *  Pittsburgh PA 15213-3890
23 *
24 * any improvements or extensions that they make and grant Carnegie Mellon
25 * the rights to redistribute these changes.
26 */
27/*
28 * Copyright (c) 1982, 1986, 1989 The Regents of the University of California.
29 * All rights reserved.
30 *
31 * Redistribution and use in source and binary forms are permitted
32 * provided that the above copyright notice and this paragraph are
33 * duplicated in all such forms and that any documentation,
34 * advertising materials, and other materials related to such
35 * distribution and use acknowledge that the software was developed
36 * by the University of California, Berkeley.  The name of the
37 * University may not be used to endorse or promote products derived
38 * from this software without specific prior written permission.
39 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
40 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
41 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
42 *
43 *	@(#)dir.h	7.6 (Berkeley) 5/9/89
44 */
45
46#ifndef _BOOT_UFS_DIR_H_
47#define	_BOOT_UFS_DIR_H_
48
49/*
50 * A directory consists of some number of blocks of DIRBLKSIZ
51 * bytes, where DIRBLKSIZ is chosen such that it can be transferred
52 * to disk in a single atomic operation (e.g. 512 bytes on most machines).
53 *
54 * Each DIRBLKSIZ byte block contains some number of directory entry
55 * structures, which are of variable length.  Each directory entry has
56 * a struct direct at the front of it, containing its inode number,
57 * the length of the entry, and the length of the name contained in
58 * the entry.  These are followed by the name padded to a 4 byte boundary
59 * with null bytes.  All names are guaranteed null terminated.
60 * The maximum length of a name in a directory is MAXNAMLEN.
61 *
62 * The macro DIRSIZ(dp) gives the amount of space required to represent
63 * a directory entry.  Free space in a directory is represented by
64 * entries which have dp->d_reclen > DIRSIZ(dp).  All DIRBLKSIZ bytes
65 * in a directory block are claimed by the directory entries.  This
66 * usually results in the last entry in a directory having a large
67 * dp->d_reclen.  When entries are deleted from a directory, the
68 * space is returned to the previous entry in the same directory
69 * block by increasing its dp->d_reclen.  If the first entry of
70 * a directory block is free, then its dp->d_ino is set to 0.
71 * Entries other than the first in a directory do not normally have
72 * dp->d_ino set to 0.
73 */
74#define DIRBLKSIZ	DEV_BSIZE
75#define	MAXNAMLEN	255
76
77struct direct
78  {
79    u_int d_ino;		/* inode number of entry */
80    u_short d_reclen;		/* length of this record */
81    u_short d_namlen;		/* length of string in d_name */
82    char d_name[MAXNAMLEN + 1];	/* name with length <= MAXNAMLEN */
83  };
84
85/*
86 * The DIRSIZ macro gives the minimum record length which will hold
87 * the directory entry.  This requires the amount of space in struct direct
88 * without the d_name field, plus enough space for the name with a terminating
89 * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary.
90 */
91#undef DIRSIZ
92#define DIRSIZ(dp) \
93    ((sizeof (struct direct) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3))
94
95#ifdef KERNEL
96/*
97 * Template for manipulating directories.
98 * Should use struct direct's, but the name field
99 * is MAXNAMLEN - 1, and this just won't do.
100 */
101struct dirtemplate
102  {
103    u_int dot_ino;
104    short dot_reclen;
105    short dot_namlen;
106    char dot_name[4];		/* must be multiple of 4 */
107    u_int dotdot_ino;
108    short dotdot_reclen;
109    short dotdot_namlen;
110    char dotdot_name[4];	/* ditto */
111  };
112#endif
113
114/*
115 * The following information should be obtained from <dirent.h>
116 * and is provided solely (and temporarily) for backward compatibility.
117 */
118#ifndef KERNEL
119#define d_fileno d_ino		/* compatibility with POSIX */
120#ifndef DEV_BSIZE
121#define	DEV_BSIZE	512
122#endif
123/*
124 * Definitions for library routines operating on directories.
125 */
126typedef struct _dirdesc
127  {
128    int dd_fd;
129    int dd_loc;
130    int dd_size;
131    char dd_buf[DIRBLKSIZ];
132  }
133DIR;
134
135#define dirfd(dirp)	((dirp)->dd_fd)
136
137#ifndef NULL
138#define NULL 0
139#endif
140extern DIR *opendir ();
141extern struct direct *readdir ();
142extern int telldir ();
143extern void seekdir ();
144#define rewinddir(dirp)	seekdir((dirp), (long)0)
145extern void closedir ();
146#endif /* not KERNEL */
147#endif /* _BOOT_UFS_DIR_H_ */
148