www.pudn.com > sliplib.rar > slipLib.c

#include  
#include "slipLib.h" 
 
 
SLIP_ID slipCreate( const int iMaxBytes,  const unsigned int uiOption, 
                    int ( * pfDecodeCallBack )( ), int ( * pfEncodeCallBack )( ) ) 
{ 
	SLIP_ID  strSlipId   = NULL; 
	void     *pvMemStart = NULL; 
	 
	if( ( iMaxBytes <= 0 ) || ( ( pfDecodeCallBack == NULL ) && ( pfEncodeCallBack == NULL ) ) ) 
    { 
    	printf( "[ slipCreate ]:The para is invalid.\n" ); 
    	return( NULL ); 
    } 
     
    if( ( pvMemStart = ( void* )malloc( sizeof( struct SLIP ) + iMaxBytes * 2 ) ) == NULL ) 
	{ 
		printf( "[ slipCreate ]:malloc failed. " ); 
		return( NULL ); 
	} 
	 
    strSlipId = pvMemStart; 
	 
	strSlipId->enumSlipDecodeStatus     = SLIP_STATUS_NOSTART; 
	strSlipId->pucSlipDecodeBuff        = pvMemStart + sizeof( struct SLIP ); 
	strSlipId->iSlipDecodeBuffMaxLength = iMaxBytes; 
	strSlipId->iSlipDecodeBuffLength    = 0; 
/*	strSlipId->uiSlipDecodeErrorNo      = 0;  */ 
	strSlipId->pucSlipEncodeBuff        = pvMemStart + sizeof( struct SLIP ) + iMaxBytes; 
	strSlipId->iSlipEncodeBuffMaxLength = iMaxBytes; 
	strSlipId->iSlipEncodeBuffLength    = 0; 
/*	strSlipId->uiOption                 = 0;  */ 
	strSlipId->pfDecodeCallBack         = pfDecodeCallBack; 
	strSlipId->pfEncodeCallBack         = pfEncodeCallBack; 
	 
	return( strSlipId ); 
}	 
	 
 
int slipDelete( SLIP_ID strSlipId ) 
{ 
	if( strSlipId != NULL ) 
	{ 
		free( strSlipId ); 
	    strSlipId == NULL; 
	} 
	return( 1 ); 
}	 
 
 
int slipDecode( SLIP_ID strSlipId, const unsigned char * pucPackedBuff, const int iPackedBuffLength ) 
{ 
	int i; 
	 
	if( ( strSlipId == NULL ) || ( pucPackedBuff == NULL ) || ( iPackedBuffLength <= 0 ) ) 
	{ 
		printf( "[ slipDecode ]:The para is invalid.\n" ); 
		return( 0 ); 
	} 
	 
	for( i = 0; i < iPackedBuffLength; i++ ) 
	{ 
		switch( pucPackedBuff[ i ] ) 
		{ 
			case SLIP_END: 
				if( strSlipId->enumSlipDecodeStatus == SLIP_STATUS_NOSTART )                                       
				{                                                                                                  
				    strSlipId->enumSlipDecodeStatus  = SLIP_STATUS_START; 
				    strSlipId->iSlipDecodeBuffLength = 0;  
				}                                                                                                  
				else if( strSlipId->enumSlipDecodeStatus == SLIP_STATUS_START )                                    
				{ 
					strSlipId->enumSlipDecodeStatus = SLIP_STATUS_NOSTART; 
					strSlipId->pfDecodeCallBack( strSlipId->pucSlipDecodeBuff, strSlipId->iSlipDecodeBuffLength ); 
					strSlipId->iSlipDecodeBuffLength = 0;  
				} 
			    break; 
			case SLIP_ESC: 
				if( pucPackedBuff[ i + 1 ] == SLIP_TRANS_END ) 
				{ 
					strSlipId->pucSlipDecodeBuff[ strSlipId->iSlipDecodeBuffLength++ ] = SLIP_END; 
					i++; 
				} 
				else if( pucPackedBuff[ i + 1 ] == SLIP_TRANS_ESC ) 
				{ 
					strSlipId->pucSlipDecodeBuff[ strSlipId->iSlipDecodeBuffLength++ ] = SLIP_ESC; 
					i++; 
				} 
				break; 
			default: 
				strSlipId->pucSlipDecodeBuff[ strSlipId->iSlipDecodeBuffLength++ ] = pucPackedBuff[ i ]; 
				break; 
		} 
	} 
	 
    return( strSlipId->iSlipDecodeBuffLength ); 
} 
 
 
int slipEncode( SLIP_ID strSlipId, const unsigned char * pucUnpackedBuff, const int iUnpackedBuffLength ) 
{ 
	int i; 
	 
	if( ( strSlipId == NULL ) || ( pucUnpackedBuff == NULL ) || ( iUnpackedBuffLength <= 0 ) ) 
	{ 
		printf( "[ slipEncode ]:The para is invalid.\n" ); 
		return( 0 ); 
	} 
	 
	strSlipId->pucSlipEncodeBuff[ 0 ] = SLIP_END; 
	strSlipId->iSlipEncodeBuffLength  = 1; 
	 
	for( i = 0; i < iUnpackedBuffLength; i++ ) 
	{ 
		switch( pucUnpackedBuff[ i ] ) 
		{ 
			case SLIP_END: 
				strSlipId->pucSlipEncodeBuff[ strSlipId->iSlipEncodeBuffLength++ ] = SLIP_ESC; 
				strSlipId->pucSlipEncodeBuff[ strSlipId->iSlipEncodeBuffLength++ ] = SLIP_TRANS_END; 
				break; 
			case SLIP_ESC: 
				strSlipId->pucSlipEncodeBuff[ strSlipId->iSlipEncodeBuffLength++ ] = SLIP_ESC; 
				strSlipId->pucSlipEncodeBuff[ strSlipId->iSlipEncodeBuffLength++ ] = SLIP_TRANS_ESC; 
				break; 
			default: 
				strSlipId->pucSlipEncodeBuff[ strSlipId->iSlipEncodeBuffLength++ ] = pucUnpackedBuff[ i ]; 
				break; 
		} 
	} 
	strSlipId->pucSlipEncodeBuff[ strSlipId->iSlipEncodeBuffLength ] = SLIP_END; 
	 
	return( strSlipId->pfEncodeCallBack( strSlipId->pucSlipEncodeBuff, strSlipId->iSlipEncodeBuffLength + 1 ) ); 
}