xref: /netbsd-src/usr.sbin/mtree/crc.c (revision 220b5c059a84c51ea44107ea8951a57ffaecdc8c)
1 /*	$NetBSD: crc.c,v 1.2 2001/11/10 07:13:07 lukem 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. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 #ifndef lint
41 #if 0
42 static char sccsid[] = "@(#)crc.c	8.1 (Berkeley) 6/17/93";
43 #else
44 __RCSID("$NetBSD: crc.c,v 1.2 2001/11/10 07:13:07 lukem Exp $");
45 #endif
46 #endif /* not lint */
47 
48 #include <sys/types.h>
49 
50 #include <fts.h>
51 #include <stdio.h>
52 #include <time.h>
53 #include <unistd.h>
54 
55 #include "extern.h"
56 
57 static const u_int32_t crctab[] = {
58 	0x0,
59 	0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
60 	0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6,
61 	0x2b4bcb61, 0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd,
62 	0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9, 0x5f15adac,
63 	0x5bd4b01b, 0x569796c2, 0x52568b75, 0x6a1936c8, 0x6ed82b7f,
64 	0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3, 0x709f7b7a,
65 	0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
66 	0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58,
67 	0xbaea46ef, 0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033,
68 	0xa4ad16ea, 0xa06c0b5d, 0xd4326d90, 0xd0f37027, 0xddb056fe,
69 	0xd9714b49, 0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95,
70 	0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1, 0xe13ef6f4,
71 	0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
72 	0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5,
73 	0x2ac12072, 0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16,
74 	0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca, 0x7897ab07,
75 	0x7c56b6b0, 0x71159069, 0x75d48dde, 0x6b93dddb, 0x6f52c06c,
76 	0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1,
77 	0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
78 	0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b,
79 	0xbb60adfc, 0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698,
80 	0x832f1041, 0x87ee0df6, 0x99a95df3, 0x9d684044, 0x902b669d,
81 	0x94ea7b2a, 0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e,
82 	0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2, 0xc6bcf05f,
83 	0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
84 	0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80,
85 	0x644fc637, 0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb,
86 	0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f, 0x5c007b8a,
87 	0x58c1663d, 0x558240e4, 0x51435d53, 0x251d3b9e, 0x21dc2629,
88 	0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5, 0x3f9b762c,
89 	0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
90 	0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e,
91 	0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65,
92 	0xeba91bbc, 0xef68060b, 0xd727bbb6, 0xd3e6a601, 0xdea580d8,
93 	0xda649d6f, 0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3,
94 	0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7, 0xae3afba2,
95 	0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
96 	0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74,
97 	0x857130c3, 0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640,
98 	0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c, 0x7b827d21,
99 	0x7f436096, 0x7200464f, 0x76c15bf8, 0x68860bfd, 0x6c47164a,
100 	0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e, 0x18197087,
101 	0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
102 	0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d,
103 	0x2056cd3a, 0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce,
104 	0xcc2b1d17, 0xc8ea00a0, 0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb,
105 	0xdbee767c, 0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18,
106 	0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4, 0x89b8fd09,
107 	0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
108 	0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf,
109 	0xa2f33668, 0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
110 };
111 
112 /*
113  * Compute a POSIX 1003.2 checksum.  This routine has been broken out so that
114  * other programs can use it.  It takes a file descriptor to read from and
115  * locations to store the crc and the number of bytes read.  It returns 0 on
116  * success and 1 on failure.  Errno is set on failure.
117  */
118 extern int sflag;
119 u_int32_t crc_total = ~0;		/* The crc over a number of files. */
120 
121 int
122 crc(fd, cval, clen)
123 	register int fd;
124 	u_int32_t *cval, *clen;
125 {
126 	register u_char *p;
127 	register int nr;
128 	register u_int32_t thecrc, len;
129 	register u_int32_t crctot;
130 	u_char buf[16 * 1024];
131 
132 #define	COMPUTE(var, ch)	(var) = (var) << 8 ^ crctab[(var) >> 24 ^ (ch)]
133 
134 	thecrc = len = 0;
135 	if (sflag)
136 		crctot = ~crc_total;
137 	while ((nr = read(fd, buf, sizeof(buf))) > 0)
138 		if (sflag) {
139 			for (len += nr, p = buf; nr--; ++p) {
140 				COMPUTE(thecrc, *p);
141 				COMPUTE(crctot, *p);
142 			}
143 		} else {
144 			for (len += nr, p = buf; nr--; ++p)
145 				COMPUTE(thecrc, *p);
146 		}
147 	if (nr < 0)
148 		return (1);
149 
150 	*clen = len;
151 
152 	/* Include the length of the file. */
153 	if (sflag) {
154 		for (; len != 0; len >>= 8) {
155 			COMPUTE(thecrc, len & 0xff);
156 			COMPUTE(crctot, len & 0xff);
157 		}
158 	} else {
159 		for (; len != 0; len >>= 8)
160 			COMPUTE(thecrc, len & 0xff);
161 	}
162 
163 	*cval = ~thecrc;
164 	if (sflag)
165 		crc_total = ~crctot;
166 	return (0);
167 }
168