1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 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 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)dir.h 8.2 (Berkeley) 1/21/94 35 */ 36 37 #ifndef _UFS_UFS_DIR_H_ 38 #define _UFS_UFS_DIR_H_ 39 40 /* 41 * Theoretically, directories can be more than 2Gb in length, however, in 42 * practice this seems unlikely. So, we define the type doff_t as a 32-bit 43 * quantity to keep down the cost of doing lookup on a 32-bit machine. 44 */ 45 #define doff_t int32_t 46 #define MAXDIRSIZE (0x7fffffff) 47 48 /* 49 * A directory consists of some number of blocks of DIRBLKSIZ 50 * bytes, where DIRBLKSIZ is chosen such that it can be transferred 51 * to disk in a single atomic operation (e.g. 512 bytes on most machines). 52 * 53 * Each DIRBLKSIZ byte block contains some number of directory entry 54 * structures, which are of variable length. Each directory entry has 55 * a struct direct at the front of it, containing its inode number, 56 * the length of the entry, and the length of the name contained in 57 * the entry. These are followed by the name padded to a 4 byte boundary 58 * with null bytes. All names are guaranteed null terminated. 59 * The maximum length of a name in a directory is UFS_MAXNAMLEN. 60 * 61 * The macro DIRSIZ(fmt, dp) gives the amount of space required to represent 62 * a directory entry. Free space in a directory is represented by 63 * entries which have dp->d_reclen > DIRSIZ(fmt, dp). All DIRBLKSIZ bytes 64 * in a directory block are claimed by the directory entries. This 65 * usually results in the last entry in a directory having a large 66 * dp->d_reclen. When entries are deleted from a directory, the 67 * space is returned to the previous entry in the same directory 68 * block by increasing its dp->d_reclen. If the first entry of 69 * a directory block is free, then its dp->d_ino is set to 0. 70 * Entries other than the first in a directory do not normally have 71 * dp->d_ino set to 0. 72 */ 73 #define DIRBLKSIZ DEV_BSIZE 74 #define UFS_MAXNAMLEN 255 75 76 struct direct { 77 u_int32_t d_ino; /* inode number of entry */ 78 u_int16_t d_reclen; /* length of this record */ 79 u_int16_t d_namlen; /* length of string in d_name */ 80 char d_name[UFS_MAXNAMLEN + 1]; 81 /* name with length <= UFS_MAXNAMLEN */ 82 }; 83 84 /* 85 * File types 86 */ 87 #define DT_UNKNOWN 0 88 #define DT_FIFO 1 89 #define DT_CHR 2 90 #define DT_DIR 4 91 #define DT_BLK 6 92 #define DT_REG 8 93 #define DT_LNK 10 94 #define DT_SOCK 12 95 #define DT_WHT 14 96 97 /* 98 * Convert between stat structure types and directory types. 99 */ 100 #define IFTODT(mode) (((mode) & 0170000) >> 12) 101 #define DTTOIF(dirtype) ((dirtype) << 12) 102 103 /* 104 * The DIRSIZ macro gives the minimum record length which will hold 105 * the directory entry. This requires the amount of space in struct direct 106 * without the d_name field, plus enough space for the name with a terminating 107 * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary. 108 * 109 * 110 */ 111 #define DIRECTSIZ(namlen) \ 112 ((__offsetof(struct direct, d_name) + \ 113 ((namlen)+1)*sizeof(((struct direct *)0)->d_name[0]) + 3) & ~3) 114 #if (BYTE_ORDER == LITTLE_ENDIAN) 115 #define DIRSIZ(oldfmt, dp) \ 116 ((oldfmt) ? DIRECTSIZ((dp)->d_type) : DIRECTSIZ((dp)->d_namlen)) 117 #else 118 #define DIRSIZ(oldfmt, dp) \ 119 DIRECTSIZ((dp)->d_namlen) 120 #endif 121 #define OLDDIRFMT 1 122 #define NEWDIRFMT 0 123 124 /* 125 * Template for manipulating directories. Should use struct direct's, 126 * but the name field is UFS_MAXNAMLEN - 1, and this just won't do. 127 */ 128 struct dirtemplate { 129 u_int32_t dot_ino; 130 int16_t dot_reclen; 131 u_int8_t dot_type; 132 u_int8_t dot_namlen; 133 char dot_name[4]; /* must be multiple of 4 */ 134 u_int32_t dotdot_ino; 135 int16_t dotdot_reclen; 136 u_int8_t dotdot_type; 137 u_int8_t dotdot_namlen; 138 char dotdot_name[4]; /* ditto */ 139 }; 140 141 /* 142 * This is the old format of directories, sanz type element. 143 */ 144 struct odirtemplate { 145 u_int32_t dot_ino; 146 int16_t dot_reclen; 147 u_int16_t dot_namlen; 148 char dot_name[4]; /* must be multiple of 4 */ 149 u_int32_t dotdot_ino; 150 int16_t dotdot_reclen; 151 u_int16_t dotdot_namlen; 152 char dotdot_name[4]; /* ditto */ 153 }; 154 #endif /* !_DIR_H_ */ 155