com_crc16.c File Reference

#include "darkplaces.h"

Include dependency graph for com_crc16.c:

Go to the source code of this file.

Macros
#define	CRC_INIT_VALUE   0xffff
#define	CRC_XOR_VALUE   0x0000

Functions
unsigned char	COM_BlockSequenceCRCByteQW (unsigned char *base, int length, int sequence)
unsigned short	CRC_Block (const unsigned char *data, size_t size)
unsigned short	CRC_Block_CaseInsensitive (const unsigned char *data, size_t size)

Variables
static const u8	chktbl [1024+4]
static const u16	crctable [256]

Macro Definition Documentation

CRC_INIT_VALUE

#define CRC_INIT_VALUE   0xffff

Definition at line 36 of file com_crc16.c.

Referenced by CRC_Block(), and CRC_Block_CaseInsensitive().

CRC_XOR_VALUE

#define CRC_XOR_VALUE   0x0000

Definition at line 37 of file com_crc16.c.

Referenced by CRC_Block(), and CRC_Block_CaseInsensitive().

Function Documentation

COM_BlockSequenceCRCByteQW()

unsigned char COM_BlockSequenceCRCByteQW	(	unsigned char *	base,
		int	length,
		int	sequence )

Definition at line 132 of file com_crc16.c.

{
    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;
}

References chktbl, CRC_Block(), and length.

Referenced by CL_SendMove().

CRC_Block()

unsigned short CRC_Block	(	const unsigned char *	data,
		size_t	size )

Definition at line 75 of file com_crc16.c.

{
    unsigned short crc = CRC_INIT_VALUE;
    while (size--)
        crc = (crc << 8) ^ crctable[(crc >> 8) ^ (*data++)];
    return crc ^ CRC_XOR_VALUE;
}

References CRC_INIT_VALUE, CRC_XOR_VALUE, crctable, data, and size.

Referenced by CL_StopDownload(), CL_VM_Init(), COM_BlockSequenceCRCByteQW(), CompressedImageCache_Add(), CompressedImageCache_Find(), Crypto_ClearHostKey(), Crypto_RetrieveHostKey(), Crypto_StoreHostKey(), Cvar_FindVar(), Cvar_FindVarLink(), Cvar_Link(), Cvar_RegisterVirtual(), Draw_CachePic_Flags(), Draw_FreePic(), Draw_NewPic(), FS_CRCFile(), Mod_LoadModel(), Mod_Q1BSP_LoadSplitSky(), Mod_Q1BSP_LoadTextures(), PRVM_PO_Load(), PRVM_PO_Lookup(), PRVM_Prog_Load(), R_InitShaderModeInfo(), R_SkinFrame_Find(), R_SkinFrame_FindNextByName(), R_SkinFrame_LoadInternal8bit(), R_SkinFrame_LoadInternalQuake(), SV_Prepare_CSQC(), SV_ReadClientMessage(), and VM_crc16().

CRC_Block_CaseInsensitive()

unsigned short CRC_Block_CaseInsensitive	(	const unsigned char *	data,
		size_t	size )

Definition at line 83 of file com_crc16.c.

{
    unsigned short crc = CRC_INIT_VALUE;
    while (size--)
        crc = (crc << 8) ^ crctable[(crc >> 8) ^ (tolower(*data++))];
    return crc ^ CRC_XOR_VALUE;
}

References CRC_INIT_VALUE, CRC_XOR_VALUE, crctable, data, and size.

Referenced by Mod_LookupQ3Shader(), Q3Shader_AddToHash(), and VM_crc16().

Variable Documentation

chktbl

const u8 chktbl[1024+4]

static

Definition at line 92 of file com_crc16.c.

{
    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
};

Referenced by COM_BlockSequenceCRCByteQW().

crctable

const u16 crctable[256]

static

Definition at line 39 of file com_crc16.c.

{
    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
};

Referenced by CRC_Block(), and CRC_Block_CaseInsensitive().