1 /* $NetBSD: dir.h,v 1.13 2002/02/06 15:44:49 lukem Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)dir.h 8.5 (Berkeley) 4/27/95 41 */ 42 43 #ifndef _DIR_H_ 44 #define _DIR_H_ 45 46 /* 47 * Theoretically, directories can be more than 2Gb in length, however, in 48 * practice this seems unlikely. So, we define the type doff_t as a 32-bit 49 * quantity to keep down the cost of doing lookup on a 32-bit machine. 50 */ 51 #define doff_t int32_t 52 #define MAXDIRSIZE (0x7fffffff) 53 54 /* 55 * A directory consists of some number of blocks of DIRBLKSIZ 56 * bytes, where DIRBLKSIZ is chosen such that it can be transferred 57 * to disk in a single atomic operation (e.g. 512 bytes on most machines). 58 * 59 * Each DIRBLKSIZ byte block contains some number of directory entry 60 * structures, which are of variable length. Each directory entry has 61 * a struct direct at the front of it, containing its inode number, 62 * the length of the entry, and the length of the name contained in 63 * the entry. These are followed by the name padded to a 4 byte boundary 64 * with null bytes. All names are guaranteed null terminated. 65 * The maximum length of a name in a directory is MAXNAMLEN. 66 * 67 * The macro DIRSIZ(fmt, dp) gives the amount of space required to represent 68 * a directory entry. Free space in a directory is represented by 69 * entries which have dp->d_reclen > DIRSIZ(fmt, dp). All DIRBLKSIZ bytes 70 * in a directory block are claimed by the directory entries. This 71 * usually results in the last entry in a directory having a large 72 * dp->d_reclen. When entries are deleted from a directory, the 73 * space is returned to the previous entry in the same directory 74 * block by increasing its dp->d_reclen. If the first entry of 75 * a directory block is free, then its dp->d_ino is set to 0. 76 * Entries other than the first in a directory do not normally have 77 * dp->d_ino set to 0. 78 */ 79 #undef DIRBLKSIZ 80 #define DIRBLKSIZ DEV_BSIZE 81 #undef MAXNAMLEN 82 #define MAXNAMLEN 255 83 84 struct direct { 85 u_int32_t d_ino; /* inode number of entry */ 86 u_int16_t d_reclen; /* length of this record */ 87 u_int8_t d_type; /* file type, see below */ 88 u_int8_t d_namlen; /* length of string in d_name */ 89 char d_name[MAXNAMLEN + 1];/* name with length <= MAXNAMLEN */ 90 }; 91 92 /* 93 * File types 94 */ 95 #define DT_UNKNOWN 0 96 #define DT_FIFO 1 97 #define DT_CHR 2 98 #define DT_DIR 4 99 #define DT_BLK 6 100 #define DT_REG 8 101 #define DT_LNK 10 102 #define DT_SOCK 12 103 #define DT_WHT 14 104 105 /* 106 * Convert between stat structure types and directory types. 107 */ 108 #define IFTODT(mode) (((mode) & 0170000) >> 12) 109 #define DTTOIF(dirtype) ((dirtype) << 12) 110 111 /* 112 * The DIRSIZ macro gives the minimum record length which will hold 113 * the directory entry. This requires the amount of space in struct direct 114 * without the d_name field, plus enough space for the name with a terminating 115 * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary. 116 */ 117 #define DIRECTSIZ(namlen) \ 118 ((sizeof(struct direct) - (MAXNAMLEN+1)) + (((namlen)+1 + 3) &~ 3)) 119 120 #if (BYTE_ORDER == LITTLE_ENDIAN) 121 #define DIRSIZ(oldfmt, dp, needswap) \ 122 (((oldfmt) && !(needswap)) ? \ 123 DIRECTSIZ((dp)->d_type) : DIRECTSIZ((dp)->d_namlen)) 124 #else 125 #define DIRSIZ(oldfmt, dp, needswap) \ 126 (((oldfmt) && (needswap)) ? \ 127 DIRECTSIZ((dp)->d_type) : DIRECTSIZ((dp)->d_namlen)) 128 #endif 129 130 #define OLDDIRFMT 1 131 #define NEWDIRFMT 0 132 133 /* 134 * Template for manipulating directories. Should use struct direct's, 135 * but the name field is MAXNAMLEN - 1, and this just won't do. 136 */ 137 struct dirtemplate { 138 u_int32_t dot_ino; 139 int16_t dot_reclen; 140 u_int8_t dot_type; 141 u_int8_t dot_namlen; 142 char dot_name[4]; /* must be multiple of 4 */ 143 u_int32_t dotdot_ino; 144 int16_t dotdot_reclen; 145 u_int8_t dotdot_type; 146 u_int8_t dotdot_namlen; 147 char dotdot_name[4]; /* ditto */ 148 }; 149 150 /* 151 * This is the old format of directories, sanz type element. 152 */ 153 struct odirtemplate { 154 u_int32_t dot_ino; 155 int16_t dot_reclen; 156 u_int16_t dot_namlen; 157 char dot_name[4]; /* must be multiple of 4 */ 158 u_int32_t dotdot_ino; 159 int16_t dotdot_reclen; 160 u_int16_t dotdot_namlen; 161 char dotdot_name[4]; /* ditto */ 162 }; 163 #endif /* !_DIR_H_ */ 164