/*************************************************************************
* (C) 2008 AITNET ltd - Sofia/Bulgaria - <misho@aitbg.com>
*  by Michael Pounov <misho@openbsd-bg.org>
*
* $Author: misho $
* $Id: aitcrc.h,v 1.3 2010/06/13 16:13:51 misho Exp $
*
*************************************************************************/
#ifndef __AITCRC_H
#define __AITCRC_H


#include <sys/types.h>


#define REVOPTS_REVERTBYTE	1
#define REVOPTS_REVERTCRC	2


struct tagCRCPoly {
	u_char	poly_bits;
	u_int	poly_num;
	char	poly_name[19];
};	// size 24bytes
typedef struct tagCRCPoly crcPoly_t;


// -------------------------------------------------------
// crc_GetErrno() Get error code of last operation
inline int crc_GetErrno();
// crc_GetError() Get error text of last operation
inline const char *crc_GetError();
// -------------------------------------------------------

/*
 * crcReflect() Reflect all bits of number 
 * @crcNum = Number for reflection
 * @crcBits = Number width bits 
 * return: -1 error, !=-1 reflecting number
 */
inline u_int crcReflect(u_int crcNum, u_char crcBits);
/*
 * crcCalc() Generic CRC calculation function for many sub variants of CRC algorithms
 * @psBuf = Data for calculation
 * @bufLen = Length of data
 * @crcBits = CRC algorithm bits (1, 4, 5, 6, 7, 8, 10, 11, 12, 15, 16, 24, 30, 32)
 * @RevOpts = Options for computation (REVOPTS_REVERTBYTE, REVOPTS_REVERTCRC)
 * @initCRC = Initial CRC value
 * @xorCRC = Last xor CRC value
 * return: -1 error, !=-1 CRC checksum
 */
inline u_int crcCalc(u_char * __restrict psBuf, u_int bufLen, u_char crcBits, 
		u_char RevOpts, u_int initCRC, u_int xorCRC);

/*
 * crcIP() Checksum in IP communication
 * @nBuf = Data for calculation
 * @bufLen = Length of data
 * return: -1 error, !=-1 Checksum
 */
inline u_short crcIP(u_short * __restrict nBuf, int bufLen);
/*
 * crcFletcher16() Fletcher-16 Checksum computing
 * @nBuf = Data for calculation
 * @bufLen = Length of data
 * return: -1 error, !=-1 Checksum
 */
inline u_short crcFletcher16(u_short * __restrict nBuf, int bufLen);
/*
 * crcFletcher() Fletcher-32 Checksum computing
 * @nBuf = Data for calculation
 * @bufLen = Length of data
 * return: -1 error, !=-1 Checksum
 */
inline u_int crcFletcher(u_short * __restrict nBuf, int bufLen);
/*
 * crcAdler() crcAdler-32 Checksum computing
 * @psBuf = Data for calculation
 * @bufLen = Length of data
 * return: -1 error, !=-1 Checksum
 */
inline u_int crcAdler(u_char * __restrict psBuf, int bufLen);

/*
 * crcEther() Checksum in Ethernet communication
 * @psBuf = Data for calculation
 * @bufLen = Length of data
 * return: -1 error, !=-1 Checksum
 */
#define crcEther(psBuf, bufLen) crcCalc((psBuf), (bufLen), 32, 3, 0xFFFFFFFF, 0xFFFFFFFF)

/*
 * crcPelco() Calculate Pelco D/P CRC
 * @ver = Pelco protocol version (Dd | Pp)
 * @pkt = Packet for calculate crc
 * return: crc for packet, if is 0 check and crc_GetErrno() == 1 
 	Pelco protocol not supported
 */
inline u_char crcPelco(u_char ver, u_char *pkt);


#endif