1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1992 Keith Muller. 5 * Copyright (c) 1992, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Keith Muller of the University of California, San Diego. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)tables.h 8.1 (Berkeley) 5/31/93 36 * $FreeBSD$ 37 */ 38 39 /* 40 * data structures and constants used by the different databases kept by pax 41 */ 42 43 /* 44 * Hash Table Sizes MUST BE PRIME, if set too small performance suffers. 45 * Probably safe to expect 500000 inodes per tape. Assuming good key 46 * distribution (inodes) chains of under 50 long (worse case) is ok. 47 */ 48 #define L_TAB_SZ 2503 /* hard link hash table size */ 49 #define F_TAB_SZ 50503 /* file time hash table size */ 50 #define N_TAB_SZ 541 /* interactive rename hash table */ 51 #define D_TAB_SZ 317 /* unique device mapping table */ 52 #define A_TAB_SZ 317 /* ftree dir access time reset table */ 53 #define MAXKEYLEN 64 /* max number of chars for hash */ 54 55 /* 56 * file hard link structure (hashed by dev/ino and chained) used to find the 57 * hard links in a file system or with some archive formats (cpio) 58 */ 59 typedef struct hrdlnk { 60 char *name; /* name of first file seen with this ino/dev */ 61 dev_t dev; /* files device number */ 62 ino_t ino; /* files inode number */ 63 u_long nlink; /* expected link count */ 64 struct hrdlnk *fow; 65 } HRDLNK; 66 67 /* 68 * Archive write update file time table (the -u, -C flag), hashed by filename. 69 * Filenames are stored in a scratch file at seek offset into the file. The 70 * file time (mod time) and the file name length (for a quick check) are 71 * stored in a hash table node. We were forced to use a scratch file because 72 * with -u, the mtime for every node in the archive must always be available 73 * to compare against (and this data can get REALLY large with big archives). 74 * By being careful to read only when we have a good chance of a match, the 75 * performance loss is not measurable (and the size of the archive we can 76 * handle is greatly increased). 77 */ 78 typedef struct ftm { 79 int namelen; /* file name length */ 80 time_t mtime; /* files last modification time */ 81 off_t seek; /* location in scratch file */ 82 struct ftm *fow; 83 } FTM; 84 85 /* 86 * Interactive rename table (-i flag), hashed by orig filename. 87 * We assume this will not be a large table as this mapping data can only be 88 * obtained through interactive input by the user. Nobody is going to type in 89 * changes for 500000 files? We use chaining to resolve collisions. 90 */ 91 92 typedef struct namt { 93 char *oname; /* old name */ 94 char *nname; /* new name typed in by the user */ 95 struct namt *fow; 96 } NAMT; 97 98 /* 99 * Unique device mapping tables. Some protocols (e.g. cpio) require that the 100 * <c_dev,c_ino> pair will uniquely identify a file in an archive unless they 101 * are links to the same file. Appending to archives can break this. For those 102 * protocols that have this requirement we map c_dev to a unique value not seen 103 * in the archive when we append. We also try to handle inode truncation with 104 * this table. (When the inode field in the archive header are too small, we 105 * remap the dev on writes to remove accidental collisions). 106 * 107 * The list is hashed by device number using chain collision resolution. Off of 108 * each DEVT are linked the various remaps for this device based on those bits 109 * in the inode which were truncated. For example if we are just remapping to 110 * avoid a device number during an update append, off the DEVT we would have 111 * only a single DLIST that has a truncation id of 0 (no inode bits were 112 * stripped for this device so far). When we spot inode truncation we create 113 * a new mapping based on the set of bits in the inode which were stripped off. 114 * so if the top four bits of the inode are stripped and they have a pattern of 115 * 0110...... (where . are those bits not truncated) we would have a mapping 116 * assigned for all inodes that has the same 0110.... pattern (with this dev 117 * number of course). This keeps the mapping sparse and should be able to store 118 * close to the limit of files which can be represented by the optimal 119 * combination of dev and inode bits, and without creating a fouled up archive. 120 * Note we also remap truncated devs in the same way (an exercise for the 121 * dedicated reader; always wanted to say that...:) 122 */ 123 124 typedef struct devt { 125 dev_t dev; /* the orig device number we now have to map */ 126 struct devt *fow; /* new device map list */ 127 struct dlist *list; /* map list based on inode truncation bits */ 128 } DEVT; 129 130 typedef struct dlist { 131 ino_t trunc_bits; /* truncation pattern for a specific map */ 132 dev_t dev; /* the new device id we use */ 133 struct dlist *fow; 134 } DLIST; 135 136 /* 137 * ftree directory access time reset table. When we are done with with a 138 * subtree we reset the access and mod time of the directory when the tflag is 139 * set. Not really explicitly specified in the pax spec, but easy and fast to 140 * do (and this may have even been intended in the spec, it is not clear). 141 * table is hashed by inode with chaining. 142 */ 143 144 typedef struct atdir { 145 char *name; /* name of directory to reset */ 146 dev_t dev; /* dev and inode for fast lookup */ 147 ino_t ino; 148 time_t mtime; /* access and mod time to reset to */ 149 time_t atime; 150 struct atdir *fow; 151 } ATDIR; 152 153 /* 154 * created directory time and mode storage entry. After pax is finished during 155 * extraction or copy, we must reset directory access modes and times that 156 * may have been modified after creation (they no longer have the specified 157 * times and/or modes). We must reset time in the reverse order of creation, 158 * because entries are added from the top of the file tree to the bottom. 159 * We MUST reset times from leaf to root (it will not work the other 160 * direction). Entries are recorded into a spool file to make reverse 161 * reading faster. 162 */ 163 164 typedef struct dirdata { 165 int nlen; /* length of the directory name (includes \0) */ 166 off_t npos; /* position in file where this dir name starts */ 167 mode_t mode; /* file mode to restore */ 168 time_t mtime; /* mtime to set */ 169 time_t atime; /* atime to set */ 170 int frc_mode; /* do we force mode settings? */ 171 } DIRDATA; 172