-
Notifications
You must be signed in to change notification settings - Fork 41
/
com_crc16.c
149 lines (128 loc) · 6.77 KB
/
com_crc16.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
/*
Copyright (C) 1996-1997 Id Software, Inc.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
// com_crc16.c
#include "darkplaces.h"
/*
============================================================================
CRC FUNCTIONS
============================================================================
*/
// this is a 16 bit, non-reflected CRC using the polynomial 0x1021
// and the initial and final xor values shown below... in other words, the
// CCITT standard CRC used by XMODEM
#define CRC_INIT_VALUE 0xffff
#define CRC_XOR_VALUE 0x0000
static const u16 crctable[256] =
{
0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0
};
unsigned short CRC_Block(const unsigned char *data, size_t size)
{
unsigned short crc = CRC_INIT_VALUE;
while (size--)
crc = (crc << 8) ^ crctable[(crc >> 8) ^ (*data++)];
return crc ^ CRC_XOR_VALUE;
}
unsigned short CRC_Block_CaseInsensitive(const unsigned char *data, size_t size)
{
unsigned short crc = CRC_INIT_VALUE;
while (size--)
crc = (crc << 8) ^ crctable[(crc >> 8) ^ (tolower(*data++))];
return crc ^ CRC_XOR_VALUE;
}
// QuakeWorld
static const u8 chktbl[1024 + 4] =
{
0x78,0xd2,0x94,0xe3,0x41,0xec,0xd6,0xd5,0xcb,0xfc,0xdb,0x8a,0x4b,0xcc,0x85,0x01,
0x23,0xd2,0xe5,0xf2,0x29,0xa7,0x45,0x94,0x4a,0x62,0xe3,0xa5,0x6f,0x3f,0xe1,0x7a,
0x64,0xed,0x5c,0x99,0x29,0x87,0xa8,0x78,0x59,0x0d,0xaa,0x0f,0x25,0x0a,0x5c,0x58,
0xfb,0x00,0xa7,0xa8,0x8a,0x1d,0x86,0x80,0xc5,0x1f,0xd2,0x28,0x69,0x71,0x58,0xc3,
0x51,0x90,0xe1,0xf8,0x6a,0xf3,0x8f,0xb0,0x68,0xdf,0x95,0x40,0x5c,0xe4,0x24,0x6b,
0x29,0x19,0x71,0x3f,0x42,0x63,0x6c,0x48,0xe7,0xad,0xa8,0x4b,0x91,0x8f,0x42,0x36,
0x34,0xe7,0x32,0x55,0x59,0x2d,0x36,0x38,0x38,0x59,0x9b,0x08,0x16,0x4d,0x8d,0xf8,
0x0a,0xa4,0x52,0x01,0xbb,0x52,0xa9,0xfd,0x40,0x18,0x97,0x37,0xff,0xc9,0x82,0x27,
0xb2,0x64,0x60,0xce,0x00,0xd9,0x04,0xf0,0x9e,0x99,0xbd,0xce,0x8f,0x90,0x4a,0xdd,
0xe1,0xec,0x19,0x14,0xb1,0xfb,0xca,0x1e,0x98,0x0f,0xd4,0xcb,0x80,0xd6,0x05,0x63,
0xfd,0xa0,0x74,0xa6,0x86,0xf6,0x19,0x98,0x76,0x27,0x68,0xf7,0xe9,0x09,0x9a,0xf2,
0x2e,0x42,0xe1,0xbe,0x64,0x48,0x2a,0x74,0x30,0xbb,0x07,0xcc,0x1f,0xd4,0x91,0x9d,
0xac,0x55,0x53,0x25,0xb9,0x64,0xf7,0x58,0x4c,0x34,0x16,0xbc,0xf6,0x12,0x2b,0x65,
0x68,0x25,0x2e,0x29,0x1f,0xbb,0xb9,0xee,0x6d,0x0c,0x8e,0xbb,0xd2,0x5f,0x1d,0x8f,
0xc1,0x39,0xf9,0x8d,0xc0,0x39,0x75,0xcf,0x25,0x17,0xbe,0x96,0xaf,0x98,0x9f,0x5f,
0x65,0x15,0xc4,0x62,0xf8,0x55,0xfc,0xab,0x54,0xcf,0xdc,0x14,0x06,0xc8,0xfc,0x42,
0xd3,0xf0,0xad,0x10,0x08,0xcd,0xd4,0x11,0xbb,0xca,0x67,0xc6,0x48,0x5f,0x9d,0x59,
0xe3,0xe8,0x53,0x67,0x27,0x2d,0x34,0x9e,0x9e,0x24,0x29,0xdb,0x69,0x99,0x86,0xf9,
0x20,0xb5,0xbb,0x5b,0xb0,0xf9,0xc3,0x67,0xad,0x1c,0x9c,0xf7,0xcc,0xef,0xce,0x69,
0xe0,0x26,0x8f,0x79,0xbd,0xca,0x10,0x17,0xda,0xa9,0x88,0x57,0x9b,0x15,0x24,0xba,
0x84,0xd0,0xeb,0x4d,0x14,0xf5,0xfc,0xe6,0x51,0x6c,0x6f,0x64,0x6b,0x73,0xec,0x85,
0xf1,0x6f,0xe1,0x67,0x25,0x10,0x77,0x32,0x9e,0x85,0x6e,0x69,0xb1,0x83,0x00,0xe4,
0x13,0xa4,0x45,0x34,0x3b,0x40,0xff,0x41,0x82,0x89,0x79,0x57,0xfd,0xd2,0x8e,0xe8,
0xfc,0x1d,0x19,0x21,0x12,0x00,0xd7,0x66,0xe5,0xc7,0x10,0x1d,0xcb,0x75,0xe8,0xfa,
0xb6,0xee,0x7b,0x2f,0x1a,0x25,0x24,0xb9,0x9f,0x1d,0x78,0xfb,0x84,0xd0,0x17,0x05,
0x71,0xb3,0xc8,0x18,0xff,0x62,0xee,0xed,0x53,0xab,0x78,0xd3,0x65,0x2d,0xbb,0xc7,
0xc1,0xe7,0x70,0xa2,0x43,0x2c,0x7c,0xc7,0x16,0x04,0xd2,0x45,0xd5,0x6b,0x6c,0x7a,
0x5e,0xa1,0x50,0x2e,0x31,0x5b,0xcc,0xe8,0x65,0x8b,0x16,0x85,0xbf,0x82,0x83,0xfb,
0xde,0x9f,0x36,0x48,0x32,0x79,0xd6,0x9b,0xfb,0x52,0x45,0xbf,0x43,0xf7,0x0b,0x0b,
0x19,0x19,0x31,0xc3,0x85,0xec,0x1d,0x8c,0x20,0xf0,0x3a,0xfa,0x80,0x4d,0x2c,0x7d,
0xac,0x60,0x09,0xc0,0x40,0xee,0xb9,0xeb,0x13,0x5b,0xe8,0x2b,0xb1,0x20,0xf0,0xce,
0x4c,0xbd,0xc6,0x04,0x86,0x70,0xc6,0x33,0xc3,0x15,0x0f,0x65,0x19,0xfd,0xc2,0xd3,
// map checksum goes here
0x00,0x00,0x00,0x00
};
// QuakeWorld
unsigned char COM_BlockSequenceCRCByteQW(unsigned char *base, int length, int sequence)
{
const unsigned char *p;
unsigned char chkb[60 + 4];
p = chktbl + (sequence % (sizeof(chktbl) - 8));
if (length > 60)
length = 60;
memcpy(chkb, base, length);
chkb[length] = (sequence & 0xff) ^ p[0];
chkb[length+1] = p[1];
chkb[length+2] = ((sequence>>8) & 0xff) ^ p[2];
chkb[length+3] = p[3];
return CRC_Block(chkb, length + 4) & 0xff;
}