1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 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. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 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 uint32_t d_ino; /* inode number of entry */ 78 uint16_t d_reclen; /* length of this record */ 79 uint8_t d_type; /* file type, see below */ 80 uint8_t d_namlen; /* length of string in d_name */ 81 char d_name[UFS_MAXNAMLEN + 1]; 82 /* name with length <= UFS_MAXNAMLEN */ 83 }; 84 85 /* 86 * File types 87 */ 88 #define DT_UNKNOWN 0 89 #define DT_FIFO 1 90 #define DT_CHR 2 91 #define DT_DIR 4 92 #define DT_BLK 6 93 #define DT_REG 8 94 #define DT_LNK 10 95 #define DT_SOCK 12 96 #define DT_WHT 14 97 98 /* 99 * Convert between stat structure types and directory types. 100 */ 101 #define IFTODT(mode) (((mode) & 0170000) >> 12) 102 #define DTTOIF(dirtype) ((dirtype) << 12) 103 104 /* 105 * The DIRSIZ macro gives the minimum record length which will hold 106 * the directory entry. This requires the amount of space in struct direct 107 * without the d_name field, plus enough space for the name with a terminating 108 * null byte (dp->d_namlen + 1), rounded up to a 4 byte boundary. 109 */ 110 #define DIR_ROUNDUP 4 /* Directory name roundup size */ 111 #define DIRECTSIZ(namlen) \ 112 (roundup2(__offsetof(struct direct, d_name) + (namlen) + 1, DIR_ROUNDUP)) 113 #if (BYTE_ORDER == LITTLE_ENDIAN) 114 #define DIRSIZ(oldfmt, dp) \ 115 ((oldfmt) ? DIRECTSIZ((dp)->d_type) : DIRECTSIZ((dp)->d_namlen)) 116 #else 117 #define DIRSIZ(oldfmt, dp) \ 118 DIRECTSIZ((dp)->d_namlen) 119 #endif 120 #define OLDDIRFMT 1 121 #define NEWDIRFMT 0 122 123 /* 124 * Template for manipulating directories. Should use struct direct's, 125 * but the name field is UFS_MAXNAMLEN - 1, and this just won't do. 126 */ 127 struct dirtemplate { 128 uint32_t dot_ino; 129 int16_t dot_reclen; 130 uint8_t dot_type; 131 uint8_t dot_namlen; 132 char dot_name[4]; /* must be multiple of 4 */ 133 uint32_t dotdot_ino; 134 int16_t dotdot_reclen; 135 uint8_t dotdot_type; 136 uint8_t dotdot_namlen; 137 char dotdot_name[4]; /* ditto */ 138 }; 139 140 /* 141 * This is the old format of directories, sanz type element. 142 */ 143 struct odirtemplate { 144 uint32_t dot_ino; 145 int16_t dot_reclen; 146 uint16_t dot_namlen; 147 char dot_name[4]; /* must be multiple of 4 */ 148 uint32_t dotdot_ino; 149 int16_t dotdot_reclen; 150 uint16_t dotdot_namlen; 151 char dotdot_name[4]; /* ditto */ 152 }; 153 #endif /* !_DIR_H_ */ 154