usr.sbin/mtree/crc.c

   1 /*      $NetBSD: crc.c,v 1.7 2005/02/06 04:52:53 perry Exp $    */
   2
   3 /*-
   4  * Copyright (c) 1991, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * James W. Williams of NASA Goddard Space Flight Center.
   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  * 3. 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
  35 #if HAVE_NBTOOL_CONFIG_H
  36 #include "nbtool_config.h"
  37 #endif
  38
  39 #include <sys/cdefs.h>
  40 #if defined(__RCSID) && !defined(lint)
  41 #if 0
  42 static char sccsid[] = "@(#)crc.c       8.1 (Berkeley) 6/17/93";
  43 #else
  44 __RCSID("$NetBSD: crc.c,v 1.7 2005/02/06 04:52:53 perry Exp $");
  45 #endif
  46 #endif /* not lint */
  47
  48 #include <sys/types.h>
  49
  50 #include <stdio.h>
  51 #include <time.h>
  52 #include <unistd.h>
  53
  54 #include "extern.h"
  55
  56 static const u_int32_t crctab[] = {
  57         0x0,
  58         0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
  59         0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6,
  60         0x2b4bcb61, 0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd,
  61         0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9, 0x5f15adac,
  62         0x5bd4b01b, 0x569796c2, 0x52568b75, 0x6a1936c8, 0x6ed82b7f,
  63         0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3, 0x709f7b7a,
  64         0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
  65         0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58,
  66         0xbaea46ef, 0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033,
  67         0xa4ad16ea, 0xa06c0b5d, 0xd4326d90, 0xd0f37027, 0xddb056fe,
  68         0xd9714b49, 0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95,
  69         0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1, 0xe13ef6f4,
  70         0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
  71         0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5,
  72         0x2ac12072, 0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16,
  73         0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca, 0x7897ab07,
  74         0x7c56b6b0, 0x71159069, 0x75d48dde, 0x6b93dddb, 0x6f52c06c,
  75         0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1,
  76         0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
  77         0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b,
  78         0xbb60adfc, 0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698,
  79         0x832f1041, 0x87ee0df6, 0x99a95df3, 0x9d684044, 0x902b669d,
  80         0x94ea7b2a, 0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e,
  81         0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2, 0xc6bcf05f,
  82         0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
  83         0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80,
  84         0x644fc637, 0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb,
  85         0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f, 0x5c007b8a,
  86         0x58c1663d, 0x558240e4, 0x51435d53, 0x251d3b9e, 0x21dc2629,
  87         0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5, 0x3f9b762c,
  88         0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
  89         0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e,
  90         0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65,
  91         0xeba91bbc, 0xef68060b, 0xd727bbb6, 0xd3e6a601, 0xdea580d8,
  92         0xda649d6f, 0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3,
  93         0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7, 0xae3afba2,
  94         0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
  95         0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74,
  96         0x857130c3, 0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640,
  97         0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c, 0x7b827d21,
  98         0x7f436096, 0x7200464f, 0x76c15bf8, 0x68860bfd, 0x6c47164a,
  99         0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e, 0x18197087,
 100         0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
 101         0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d,
 102         0x2056cd3a, 0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce,
 103         0xcc2b1d17, 0xc8ea00a0, 0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb,
 104         0xdbee767c, 0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18,
 105         0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4, 0x89b8fd09,
 106         0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
 107         0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf,
 108         0xa2f33668, 0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
 109 };
 110
 111 /*
 112  * Compute a POSIX 1003.2 checksum.  This routine has been broken out so that
 113  * other programs can use it.  It takes a file descriptor to read from and
 114  * locations to store the crc and the number of bytes read.  It returns 0 on
 115  * success and 1 on failure.  Errno is set on failure.
 116  */
 117 extern int sflag;
 118 u_int32_t crc_total = ~0;               /* The crc over a number of files. */
 119
 120 int
 121 crc(int fd, u_int32_t *cval, u_int32_t *clen)
 122 {
 123         u_char *p;
 124         int nr;
 125         u_int32_t thecrc, len;
 126         u_int32_t crctot;
 127         u_char buf[16 * 1024];
 128
 129 #define COMPUTE(var, ch)        (var) = (var) << 8 ^ crctab[(var) >> 24 ^ (ch)]
 130
 131         thecrc = len = crctot = 0;
 132         if (sflag)
 133                 crctot = ~crc_total;
 134         while ((nr = read(fd, buf, sizeof(buf))) > 0)
 135                 if (sflag) {
 136                         for (len += nr, p = buf; nr--; ++p) {
 137                                 COMPUTE(thecrc, *p);
 138                                 COMPUTE(crctot, *p);
 139                         }
 140                 } else {
 141                         for (len += nr, p = buf; nr--; ++p)
 142                                 COMPUTE(thecrc, *p);
 143                 }
 144         if (nr < 0)
 145                 return 1;
 146
 147         *clen = len;
 148
 149         /* Include the length of the file. */
 150         if (sflag) {
 151                 for (; len != 0; len >>= 8) {
 152                         COMPUTE(thecrc, len & 0xff);
 153                         COMPUTE(crctot, len & 0xff);
 154                 }
 155         } else {
 156                 for (; len != 0; len >>= 8)
 157                         COMPUTE(thecrc, len & 0xff);
 158         }
 159
 160         *cval = ~thecrc;
 161         if (sflag)
 162                 crc_total = ~crctot;
 163         return 0;
 164 }