TiberianDawn/NULLCONN.CPP

/*
**	Command & Conquer(tm)
**	Copyright 2025 Electronic Arts Inc.
**
**	This program is free software: you can redistribute it and/or modify
**	it under the terms of the GNU General Public License as published by
**	the Free Software Foundation, either version 3 of the License, or
**	(at your option) any later version.
**
**	This program is distributed in the hope that it will be useful,
**	but WITHOUT ANY WARRANTY; without even the implied warranty of
**	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
**	GNU General Public License for more details.
**
**	You should have received a copy of the GNU General Public License
**	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/* $Header:   F:\projects\c&c\vcs\code\nullconn.cpv   1.10   16 Oct 1995 16:51:36   JOE_BOSTIC  $ */
/***************************************************************************
 **   C O N F I D E N T I A L --- W E S T W O O D    S T U D I O S        **
 ***************************************************************************
 *                                                                         *
 *                 Project Name : Command & Conquer                        *
 *                                                                         *
 *                    File Name : NULLCONN.CPP                             *
 *                                                                         *
 *                   Programmer : Bill Randolph                            *
 *                                                                         *
 *                   Start Date : April 5, 1995		                        *
 *                                                                         *
 *                  Last Update : April 20, 1995   [DRD]                   *
 *                                                                         *
 *-------------------------------------------------------------------------*
 * Functions:    			                                                   *
 *   NullModemConnClass::NullModemConnClass -- class constructor           *
 *   NullModemConnClass::~NullModemConnClass -- class destructor           *
 *   NullModemConnClass::Init -- hardware-dependent initialization			*
 *   NullModemConnClass::Send -- hardware-dependent packet sending			*
 *   NullModemConnClass::Compute_CRC -- computes CRC for given buffer		*
 *   NullModemConnClass::Packet_Overhead_Size -- number of extra bytes     *
 * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

#include "function.h"
#include "wincomm.h"
#include "tcpip.h"

/***************************************************************************
 * NullModemConnClass::NullModemConnClass -- class constructor             *
 *                                                                         *
 * INPUT:                                                                  *
 *		numsend			desired # send queue entries									*
 *		numreceive		desired # send receive entries								*
 *		maxlen			max length of application's packets							*
 *		magicnum			application-defined magic # for the packets				*
 *                                                                         *
 * OUTPUT:                                                                 *
 *		none.																						*
 *                                                                         *
 * WARNINGS:                                                               *
 *		none.																						*
 *                                                                         *
 * HISTORY:                                                                *
 *   12/20/1994 BR : Created.                                              *
 *=========================================================================*/
NullModemConnClass::NullModemConnClass (int numsend, int numreceive,
	int maxlen, unsigned short magicnum) :
	NonSequencedConnClass (numsend, numreceive, maxlen, magicnum,
		60, 			// Retry Delta Time
		-1, 			// Max Retries (-1 means ignore this timeout parameter)
		1200)			// Timeout: 20 seconds
{
	/*------------------------------------------------------------------------
	Pre-set the port value to NULL, so Send won't send until we've been Init'd
	------------------------------------------------------------------------*/
	PortHandle = NULL;

	/*------------------------------------------------------------------------
	Allocate the Send Buffer; the parent constructor has set MaxPacketLen,
	so we can use it in our computation.
	------------------------------------------------------------------------*/
//	SendBuf = new char [MaxPacketLen + sizeof(int) * 3];
	SendBuf = new char [ Actual_Max_Packet() ];

}	/* end of NullModemConnClass */


/***************************************************************************
 * NullModemConnClass::~NullModemConnClass -- class destructor             *
 *                                                                         *
 * INPUT:                                                                  *
 *                                                                         *
 * OUTPUT:                                                                 *
 *		none.																						*
 *                                                                         *
 * WARNINGS:                                                               *
 *		none.																						*
 *                                                                         *
 * HISTORY:                                                                *
 *   12/20/1994 BR : Created.                                              *
 *=========================================================================*/
NullModemConnClass::~NullModemConnClass ()
{
	delete [] SendBuf;

}	/* end of ~NullModemConnClass */


/***************************************************************************
 * NullModemConnClass::Init -- hardware-dependent initialization				*
 *                                                                         *
 * INPUT:                                                                  *
 *		port		GreenLeaf port handle													*
 *                                                                         *
 * OUTPUT:                                                                 *
 *		none.																						*
 *                                                                         *
 * WARNINGS:                                                               *
 *		none.																						*
 *                                                                         *
 * HISTORY:                                                                *
 *   12/20/1994 BR : Created.                                              *
 *=========================================================================*/
void NullModemConnClass::Init (HANDLE port_handle)
{
	NonSequencedConnClass::Init();
	PortHandle = port_handle;

}	/* end of Init */


/***************************************************************************
 * NullModemConnClass::Send -- hardware-dependent packet sending				*
 *                                                                         *
 * INPUT:                                                                  *
 *		port		GreenLeaf port handle													*
 *                                                                         *
 * OUTPUT:                                                                 *
 *		none.																						*
 *                                                                         *
 * WARNINGS:                                                               *
 *		1 = OK, 0 = error																		*
 *                                                                         *
 * HISTORY:                                                                *
 *   12/20/1994 BR : Created.                                              *
 *=========================================================================*/
int NullModemConnClass::Send (char *buf, int buflen)
{
	//int status;
	int *ibuf;
	SerialHeaderType *header;
	unsigned long sendlen;


	/*------------------------------------------------------------------------
	Error if we haven't been properly initialized
	------------------------------------------------------------------------*/
	if ( PortHandle == NULL )
		return(false);

	/*------------------------------------------------------------------------
	Package the data into the Send Buffer
	------------------------------------------------------------------------*/
	header = (SerialHeaderType *) SendBuf;
	header->MagicNumber	= PACKET_SERIAL_START;
	header->Length			= (short) buflen;
	header->MagicNumber2	= PACKET_SERIAL_VERIFY;

	sendlen = sizeof( SerialHeaderType );
	memcpy (SendBuf + sendlen, buf, buflen);
	sendlen += buflen;
	ibuf = (int *)(SendBuf + sendlen);
	*ibuf = Compute_CRC( buf, buflen );
	sendlen += sizeof( int );

	*(SendBuf + sendlen) = '\r';
	sendlen += 1;

	/*------------------------------------------------------------------------
	Send the data
	------------------------------------------------------------------------*/
	//status =
#ifdef FORCE_WINSOCK
	if (Winsock.Get_Connected() || GameToPlay == GAME_INTERNET){
		Winsock.Write(SendBuf, (int)sendlen);
	}else{
		SerialPort->Write_To_Serial_Port((unsigned char *)SendBuf, (int)sendlen );
	}
#else
	SerialPort->Write_To_Serial_Port((unsigned char *)SendBuf, (int)sendlen );
#endif	//WINSOCK

	//if ( status == ASSUCCESS ) {
		return(true);
	//} else {
// Smart_Printf( "Write Buffer status %d, Port->status %d, sendlen %d \n", status, Port->status, sendlen );
	//	return(false);
	//}
}


/***************************************************************************
 * NullModemConnClass::Compute_CRC -- computes CRC for given buffer			*
 *                                                                         *
 * INPUT:                                                                  *
 *		buf		buffer to compute CRC for												*
 *		buflen	length of buffer in bytes												*
 *                                                                         *
 * OUTPUT:                                                                 *
 *		none.																						*
 *                                                                         *
 * WARNINGS:                                                               *
 *		none.																						*
 *                                                                         *
 * HISTORY:                                                                *
 *   12/20/1994 BR : Created.                                              *
 *=========================================================================*/
int NullModemConnClass::Compute_CRC (char *buf, int buflen)
{
	unsigned int sum, hibit;

	sum = 0;
	for (int i = 0; i < buflen; i++) {
		if ( sum & 0x80000000 ) {		// check hi bit to rotate into low bit
			hibit = 1;
		} else {
			hibit = 0;
		}

		sum <<= 1;
		sum += (hibit + (unsigned char)buf[i]);
	}

	return((int)sum);
}


/***************************************************************************
 * NullModemConnClass::Packet_Overhead_Size -- number of extra bytes       *
 *                                                                         *
 * INPUT:                                                                  *
 *		none.																						*
 *                                                                         *
 * OUTPUT:                                                                 *
 *		number of bytes used for communications only.								*
 *                                                                         *
 * WARNINGS:                                                               *
 *		none.																						*
 *                                                                         *
 * HISTORY:                                                                *
 *   04/20/1995 DRD : Created.                                             *
 *=========================================================================*/
int NullModemConnClass::Packet_Overhead_Size ( void )
{
	//
	// short for Null Modem Magic Number
	// short for Null Modem length of packet
	// int for Null Modem CRC check
	// CommHeaderType for Queued packets
	//

	return( (PACKET_SERIAL_OVERHEAD_SIZE + sizeof(CommHeaderType)) );

}	/* end of Packet_Overhead_Size */