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1 | /*- |
| 2 | * Copyright (c) 1991 The Regents of the University of California. | |
| 3 | * All rights reserved. | |
| 4 | * | |
| 5 | * This code is derived from software contributed to Berkeley by | |
| 6 | * James W. Williams of the University of Maryland. | |
| 7 | * | |
| 8 | * %sccs.include.redist.c% | |
| 9 | */ | |
| 10 | ||
| 11 | #ifndef lint | |
| 12 | static char sccsid[] = "@(#)crc.c 5.1 (Berkeley) %G%"; | |
| 13 | #endif /* not lint */ | |
| 14 | ||
| 15 | #include <sys/types.h> | |
| 16 | #include <unistd.h> | |
| 17 | ||
| 18 | u_long crctab[] = { | |
| 19 | 0x7fffffff, | |
| 20 | 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, | |
| 21 | 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, | |
| 22 | 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, | |
| 23 | 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, | |
| 24 | 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, 0x646ba8c0, | |
| 25 | 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, | |
| 26 | 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, | |
| 27 | 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, | |
| 28 | 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, | |
| 29 | 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, 0xc8d75180, | |
| 30 | 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f, | |
| 31 | 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, | |
| 32 | 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106, | |
| 33 | 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, | |
| 34 | 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, | |
| 35 | 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, 0x6b6b51f4, | |
| 36 | 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, | |
| 37 | 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, | |
| 38 | 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65, | |
| 39 | 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, | |
| 40 | 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, | |
| 41 | 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, | |
| 42 | 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, | |
| 43 | 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, 0x5edef90e, | |
| 44 | 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, | |
| 45 | 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, | |
| 46 | 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, | |
| 47 | 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, | |
| 48 | 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, 0x8708a3d2, | |
| 49 | 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, | |
| 50 | 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, | |
| 51 | 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, | |
| 52 | 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, | |
| 53 | 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, | |
| 54 | 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79, | |
| 55 | 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, | |
| 56 | 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28, | |
| 57 | 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, | |
| 58 | 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, | |
| 59 | 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, 0x95bf4a82, | |
| 60 | 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, | |
| 61 | 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, | |
| 62 | 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777, | |
| 63 | 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, | |
| 64 | 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, | |
| 65 | 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, | |
| 66 | 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, | |
| 67 | 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, 0xbdbdf21c, | |
| 68 | 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, | |
| 69 | 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, | |
| 70 | 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d | |
| 71 | }; | |
| 72 | ||
| 73 | /* | |
| 74 | * crc -- | |
| 75 | * Compute a POSIX.2 checksum. This routine has been broken out since | |
| 76 | * it is anticipated that other programs will use it. It takes a file | |
| 77 | * descriptor to read from and locations to store the crc and the number | |
| 78 | * of bytes read. It returns 0 on success and 1 on failure. Errno is | |
| 79 | * set on failure. | |
| 80 | */ | |
| 81 | crc(fd, cval, clen) | |
| 82 | register int fd; | |
| 83 | u_long *cval, *clen; | |
| 84 | { | |
| 85 | register int i, nr, step; | |
| 86 | register u_char *p; | |
| 87 | register u_long crc, total; | |
| 88 | u_char buf[8192]; | |
| 89 | ||
| 90 | crc = step = total = 0; | |
| 91 | while ((nr = read(fd, buf, sizeof(buf))) > 0) | |
| 92 | for (total += nr, p = buf; nr--;) { | |
| 93 | if (!(i = crc >> 24 ^ *p++)) { | |
| 94 | i = step++; | |
| 95 | if (step >= sizeof(crctab)/sizeof(crctab[0])) | |
| 96 | step = 0; | |
| 97 | } | |
| 98 | crc = (crc << 8) ^ crctab[i]; | |
| 99 | } | |
| 100 | if (nr < 0) | |
| 101 | return(1); | |
| 102 | ||
| 103 | *cval = crc & 0xffffffff; /* Mask to 32 bits. */ | |
| 104 | *clen = total; | |
| 105 | return(0); | |
| 106 | } |