sliplib.c.bak

SLIP打包拆包函数模块

#include <stdio.h>
#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 ) );
}