1 /* $OpenBSD: dir.h,v 1.13 2024/01/09 03:15:59 guenther Exp $ */ 2 /* $NetBSD: dir.h,v 1.8 1996/03/09 19:42:41 scottr Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1989, 1993 6 * The Regents of the University of California. All rights reserved. 7 * (c) UNIX System Laboratories, Inc. 8 * All or some portions of this file are derived from material licensed 9 * to the University of California by American Telephone and Telegraph 10 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 11 * the permission of UNIX System Laboratories, Inc. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * @(#)dir.h 8.4 (Berkeley) 8/10/94 38 */ 39 40 #ifndef _DIR_H_ 41 #define _DIR_H_ 42 43 /* 44 * Theoretically, directories can be more than 2Gb in length, however, in 45 * practice this seems unlikely. So, we define the type doff_t as a 32-bit 46 * quantity to keep down the cost of doing lookup on a 32-bit machine. 47 */ 48 #define doff_t int32_t 49 #define MAXDIRSIZE (0x7fffffff) 50 51 /* 52 * A directory consists of some number of blocks of DIRBLKSIZ 53 * bytes, where DIRBLKSIZ is chosen such that it can be transferred 54 * to disk in a single atomic operation (e.g. 512 bytes on most machines). 55 * 56 * Each DIRBLKSIZ byte block contains some number of directory entry 57 * structures, which are of variable length. Each directory entry has 58 * a struct direct at the front of it, containing its inode number, 59 * the length of the entry, and the length of the name contained in 60 * the entry. These are followed by the name padded to a 4 byte boundary 61 * with null bytes. All names are guaranteed null terminated. 62 * The maximum length of a name in a directory is MAXNAMLEN. 63 * 64 * The macro DIRSIZ(dp) gives the amount of space required to represent 65 * a directory entry. Free space in a directory is represented by 66 * entries which have dp->d_reclen > DIRSIZ(dp). All DIRBLKSIZ bytes 67 * in a directory block are claimed by the directory entries. This 68 * usually results in the last entry in a directory having a large 69 * dp->d_reclen. When entries are deleted from a directory, the 70 * space is returned to the previous entry in the same directory 71 * block by increasing its dp->d_reclen. If the first entry of 72 * a directory block is free, then its dp->d_ino is set to 0. 73 * Entries other than the first in a directory do not normally have 74 * dp->d_ino set to 0. 75 */ 76 #define DIRBLKSIZ DEV_BSIZE 77 #define MAXNAMLEN 255 78 79 struct direct { 80 u_int32_t d_ino; /* inode number of entry */ 81 u_int16_t d_reclen; /* length of this record */ 82 u_int8_t d_type; /* file type, see below */ 83 u_int8_t d_namlen; /* length of string in d_name */ 84 char d_name[MAXNAMLEN + 1];/* name with length <= MAXNAMLEN */ 85 }; 86 87 /* 88 * File types 89 */ 90 #define DT_UNKNOWN 0 91 #define DT_FIFO 1 92 #define DT_CHR 2 93 #define DT_DIR 4 94 #define DT_BLK 6 95 #define DT_REG 8 96 #define DT_LNK 10 97 #define DT_SOCK 12 98 99 /* 100 * Convert between stat structure types and directory types. 101 */ 102 #define IFTODT(mode) (((mode) & 0170000) >> 12) 103 #define DTTOIF(dirtype) ((dirtype) << 12) 104 105 /* 106 * The DIRSIZ macro gives the minimum record length which will hold 107 * the directory entry. This requires the amount of space in struct direct 108 * without the d_name field, plus enough space for the name with a terminating 109 * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary. 110 */ 111 #define DIR_ROUNDUP 4 /* Directory name roundup size */ 112 #define DIRECTSIZ(namlen) \ 113 ((offsetof(struct direct, d_name) + \ 114 ((namlen)+1)*sizeof(((struct direct *)0)->d_name[0]) + 3) & ~3) 115 #define DIRSIZ(dp) \ 116 ((sizeof(struct direct) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3)) 117 118 /* 119 * Template for manipulating directories. Should use struct direct's, 120 * but the name field is MAXNAMLEN - 1, and this just won't do. 121 */ 122 struct dirtemplate { 123 u_int32_t dot_ino; 124 int16_t dot_reclen; 125 u_int8_t dot_type; 126 u_int8_t dot_namlen; 127 char dot_name[4]; /* must be multiple of 4 */ 128 u_int32_t dotdot_ino; 129 int16_t dotdot_reclen; 130 u_int8_t dotdot_type; 131 u_int8_t dotdot_namlen; 132 char dotdot_name[4]; /* ditto */ 133 }; 134 #endif /* !_DIR_H_ */ 135