hdlcrx.c

example of SS7 file analyzer & decoder

#include <stdlib.h>

#include "HdlcRx.h"

#define HDLC_SYNCHRO_FLAG	0x7E
#define HDLC_ABORT_FLAG		0x7F
#define HDLC_PADD_FLAG		0xFF

#ifndef BIT
	typedef unsigned char BIT;
#endif


static PushBit( BIT bit, int pos, BYTE* pTabBit)
{
	int i;

	if( pos < 8)
	{
		pTabBit[pos] = bit;
	}
	else
	{
		for( i = 1; i < 8; i++)
			pTabBit[i-1] = pTabBit[i];

		pTabBit[7] = bit;
	}

}

static BYTE GetByte( BYTE* pTabBit)
{
	BYTE byte = 0x00;

	byte = pTabBit[7] << 7;
	byte |= pTabBit[6] << 6;
	byte |= pTabBit[5] << 5;
	byte |= pTabBit[4] << 4;
	byte |= pTabBit[3] << 3;
	byte |= pTabBit[2] << 2;
	byte |= pTabBit[1] << 1;
	byte |= pTabBit[0];

	return byte;
}


PHDLC_RX HdlcRxCreate()
{
	PHDLC_RX pHdlcRx;

	pHdlcRx = (PHDLC_RX)malloc( sizeof(HDLC_RX));

	if( pHdlcRx != NULL)
	{
		pHdlcRx->bSync = FALSE;
		pHdlcRx->bFiveOnes = FALSE;
		pHdlcRx->bDataReady = FALSE;
		pHdlcRx->bOpenedFrame = FALSE;
		pHdlcRx->bClosedFrame = FALSE;
		pHdlcRx->bAbortedFrame = FALSE;
		pHdlcRx->bBitStuff = FALSE;
		pHdlcRx->SyncFlag = HDLC_SYNCHRO_FLAG;
		pHdlcRx->AbortFlag = HDLC_ABORT_FLAG;
		pHdlcRx->IdleFlag = HDLC_PADD_FLAG;
		pHdlcRx->CrtBit = 0;
		pHdlcRx->NbOnes = 0;
		pHdlcRx->bSixOnes = FALSE;
	}

	return pHdlcRx;
}

void HdlcDestroy( PHDLC_RX pHdlcRx)
{
}

BYTE HdlcRxGetData( PHDLC_RX pHdlcRx)
{
	return pHdlcRx->Data;
}

BYTE HdlcRxGetFlag( PHDLC_RX pHdlcRx)
{
	return pHdlcRx->SyncFlag;
}

BOOL HdlcRxIsSynchro(PHDLC_RX pHdlcRx)
{
	return pHdlcRx->SyncFlag;
}

BOOL HdlcRxIsFrameOpen(PHDLC_RX pHdlcRx)
{
	return pHdlcRx->bOpenedFrame;
}

BOOL HdlcRxIsFrameClose(PHDLC_RX pHdlcRx)
{
	return pHdlcRx->bClosedFrame;
}

BOOL HdlcRxIsFrameAbort(PHDLC_RX pHdlcRx)
{
	return pHdlcRx->bAbortedFrame;
}

BOOL HdlcRxIsDataReady(PHDLC_RX pHdlcRx)
{
	return pHdlcRx->bDataReady;
}


BOOL HdlcRxPushByte(PHDLC_RX pHdlcRx, BYTE ByteIn)
{
	int i;
	BIT bit;
	BYTE ByteOut;

	pHdlcRx->bDataReady = FALSE;
	pHdlcRx->bClosedFrame = FALSE;
	pHdlcRx->bAbortedFrame = FALSE;

	if( pHdlcRx->bSync == FALSE)
	{
      for (i=7; i>=0; i--)
		{
			bit = (ByteIn >> i) & 0x01;
			PushBit( bit, pHdlcRx->CrtBit, pHdlcRx->Bit);

			if( pHdlcRx->CrtBit < 8)
				pHdlcRx->CrtBit++;
	
			if( pHdlcRx->CrtBit == 8)
			{
				ByteOut = GetByte( pHdlcRx->Bit);

				if( ByteOut == pHdlcRx->SyncFlag)
				{
					pHdlcRx->Data = ByteOut;
					pHdlcRx->bDataReady = TRUE;
					pHdlcRx->bSync = TRUE;

					pHdlcRx->NbOnes = 0;
					pHdlcRx->CrtBit = 0;
				}
			}
		}
	}
	else
	{
      for (i=7; i>=0; i--)
		{
			if( pHdlcRx->CrtBit == 0)
				pHdlcRx->bBitStuff = FALSE;

			bit = (ByteIn >> i) & 0x01;

			if( (pHdlcRx->bFiveOnes == TRUE) && (bit == 0) && (pHdlcRx->bOpenedFrame == TRUE))
			{
				pHdlcRx->bFiveOnes = FALSE;
				pHdlcRx->NbOnes = 0;	
				pHdlcRx->bBitStuff = TRUE;
				pHdlcRx->bSixOnes = FALSE;
			}
			else
			{
				PushBit( bit, pHdlcRx->CrtBit, pHdlcRx->Bit);
	
				if( bit == 1)
				{
					pHdlcRx->NbOnes++;
				}
				else
				{
					pHdlcRx->NbOnes = 0;
				}
				
				if( pHdlcRx->NbOnes == 5)
				{
					pHdlcRx->bFiveOnes = TRUE;
				}

				if( pHdlcRx->NbOnes >= 6)
				{
					pHdlcRx->bFiveOnes = FALSE;
					pHdlcRx->bSixOnes = TRUE;
//					pHdlcRx->NbOnes = 0;
/*
					if( pHdlcRx->bOpenedFrame == TRUE)
					{
							pHdlcRx->bSync = FALSE;

							pHdlcRx->bAbortedFrame = TRUE;
							pHdlcRx->bOpenedFrame = FALSE;

							pHdlcRx->NbOnes = 0;
							pHdlcRx->CrtBit = 0;
							break;
					}
*/
				}

				if( pHdlcRx->CrtBit < 8)
					pHdlcRx->CrtBit++;
	
				if( pHdlcRx->CrtBit == 8)
				{
					ByteOut = GetByte( pHdlcRx->Bit);

					if( pHdlcRx->bOpenedFrame == TRUE)
					{
						if( ( ByteOut == pHdlcRx->SyncFlag) && ( pHdlcRx->bBitStuff == FALSE))
						{
							pHdlcRx->Data = ByteOut;
							pHdlcRx->bDataReady = TRUE;
							pHdlcRx->bClosedFrame = TRUE;
							pHdlcRx->bOpenedFrame = FALSE;
							pHdlcRx->bSixOnes = FALSE;

							pHdlcRx->NbOnes = 0;
							pHdlcRx->CrtBit = 0;
						}
						else
						if( ( ByteOut == pHdlcRx->AbortFlag) && ( pHdlcRx->bBitStuff == FALSE))
						{
							pHdlcRx->Data = ByteOut;
							pHdlcRx->bDataReady = TRUE;
							pHdlcRx->bAbortedFrame = TRUE;
							pHdlcRx->bOpenedFrame = FALSE;
							pHdlcRx->bSixOnes = FALSE;

							pHdlcRx->NbOnes = 0;
							pHdlcRx->CrtBit = 0;
						}
						else	
						{
							pHdlcRx->Data = ByteOut;
							pHdlcRx->bDataReady = TRUE;

							if( pHdlcRx->bSixOnes == TRUE)
							{
								pHdlcRx->bSync = FALSE;

								pHdlcRx->bAbortedFrame = TRUE;
								pHdlcRx->bOpenedFrame = FALSE;

								pHdlcRx->NbOnes = 0;
							}

							pHdlcRx->bSixOnes = FALSE;

							pHdlcRx->CrtBit = 0;
						}
		
						
					}
					else
					{
						if( ByteOut == pHdlcRx->SyncFlag)
						{
							pHdlcRx->Data = ByteOut;

							pHdlcRx->bSixOnes = FALSE;

							pHdlcRx->CrtBit = 0;
						}
						else
						if( ByteOut == pHdlcRx->IdleFlag)
						{
							pHdlcRx->Data = ByteOut;

							pHdlcRx->CrtBit = 0;
						}
						else
						{
							if( pHdlcRx->Data == pHdlcRx->SyncFlag)
							{
								pHdlcRx->Data = ByteOut;
								pHdlcRx->bDataReady = TRUE;
								pHdlcRx->bOpenedFrame = TRUE;
							}

							pHdlcRx->CrtBit = 0;
						}
					}
				}
			}
		}

	}


	return TRUE;
}


/* FSC functions */


#define PPPINITFCS16    0xffff  /* Valeur Initiale du FCS ----------------*/
#define PPPGOODFCS16    0xf0b8  /* Valeur finale correcte pour FCS -------*/


static unsigned int fcstab_16[256] = {
   0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
   0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
   0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
   0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
   0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
   0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
   0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
   0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
   0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
   0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
   0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
   0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
   0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
   0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
   0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
   0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
   0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
   0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
   0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
   0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
   0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
   0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
   0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
   0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
   0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
   0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
   0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
   0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
   0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
   0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
   0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
   0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
   };


unsigned int InitializeFCS16()
{
	return PPPINITFCS16;
}

BOOL VerifyFCS16( unsigned int fcs)
{
	return (fcs == PPPGOODFCS16) ? TRUE : FALSE;
}

unsigned int ComputeFCS16(unsigned int fcs, BYTE byte)
{
	fcs = (fcs >> 8) ^ fcstab_16[(fcs ^ byte) & 0xff];

	return (fcs);
}



#define PPPINITFCS32    0xffffffff  /* Valeur Initiale du FCS ----------------*/
#define PPPGOODFCS32    0xedb88320  /* Valeur finale correcte pour FCS -------*/


static const unsigned int fcstab_32[256] =
      {
      0x00000000, 0x77073096, 0xee0e612c, 0x990951ba,
      0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
      0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
      0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
      0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
      0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
      0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec,
      0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
      0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
      0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
      0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940,
      0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
      0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116,
      0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
      0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
      0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
      0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a,
      0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
      0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818,
      0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
      0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
      0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
      0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c,
      0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
      0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
      0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
      0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
      0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
      0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086,
      0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
      0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4,
      0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
      0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
      0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
      0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
      0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
      0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe,
      0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
      0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
      0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
      0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252,
      0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
      0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60,
      0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
      0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
      0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
      0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04,
      0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
      0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a,
      0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
      0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
      0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
      0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e,
      0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
      0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
      0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
      0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
      0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
      0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0,
      0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
      0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6,
      0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
      0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
      0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
      };


unsigned long InitializeFCS32()
{
	return PPPINITFCS32;
}

BOOL VerifyFCS32( unsigned long fcs)
{
	return (fcs == PPPGOODFCS32) ? TRUE : FALSE;
}

unsigned long ComputeFCS32(unsigned long fcs, BYTE byte)
{
	fcs = (((fcs) >> 8) ^ fcstab_32[((fcs) ^ (byte)) & 0xff]);

    return (fcs ^ 0xffffffff);
}