CnC_Remastered_Collection

PACKET.CPP (20032B)

---

 //
 // Copyright 2020 Electronic Arts Inc.
 //
 // TiberianDawn.DLL and RedAlert.dll and corresponding source code 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.
 
 // TiberianDawn.DLL and RedAlert.dll and corresponding source code is distributed 
 // in the hope that it will be useful, but with permitted additional restrictions 
 // under Section 7 of the GPL. See the GNU General Public License in LICENSE.TXT 
 // distributed with this program. You should have received a copy of the 
 // GNU General Public License along with permitted additional restrictions 
 // with this program. If not, see https://github.com/electronicarts/CnC_Remastered_Collection
 
 /***************************************************************************
  *                                                                         *
  *                 Project Name : Westwood Auto Registration App           *
  *                                                                         *
  *                    File Name : PACKET.CPP                               *
  *                                                                         *
  *                   Programmer : Philip W. Gorrow                         *
  *                                                                         *
  *                   Start Date : 04/22/96                                 *
  *                                                                         *
  *                  Last Update : April 24, 1996 [PWG]                     *
  *                                                                         *
  *-------------------------------------------------------------------------*
  * Functions:                                                              *
  *   *PacketClass::Find_Field -- Finds a field if it exists in the packets *
  *   Get_Field -- Find specified name and returns data                     *
  *   PacketClass::~PacketClass -- destroys a packet class be freeing list  *
  *   PacketClass::Add_Field -- Adds a FieldClass entry to head of packet li*
  * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
 #include <stdlib.h>
 //#include <mem.h>
 #include <string.h>
 
 //enum {false=0,true=1};
 //typedef int bool;
 
 #include "packet.h"
 
 
 /**************************************************************************
  * PACKETCLASS::~PACKETCLASS -- destroys a packet class be freeing list   *
  *                                                                        *
  * INPUT:		none                                                       *
  *                                                                        *
  * OUTPUT:     none																		  *
  *                                                                        *
  * HISTORY:                                                               *
  *   04/24/1996 PWG : Created.                                            *
  *========================================================================*/
 PacketClass::~PacketClass(void)
 {
 	FieldClass *current;
 	FieldClass *next;
 	//
 	// Loop through the entire field list and delete each entry.
 	//
 	for (current = Head; current; current = next) {
 		next = current->Next;
 		delete current;
 	}
 }
 
 
 /**************************************************************************
  * PACKETCLASS::ADD_FIELD -- Adds a FieldClass entry to head of packet li *
  *                                                                        *
  * INPUT:		FieldClass * - a properly constructed field class entry.	  *
  *                                                                        *
  * OUTPUT:     none                                                       *
  *                                                                        *
  * HISTORY:                                                               *
  *   04/24/1996 PWG : Created.                                            *
  *========================================================================*/
 void PacketClass::Add_Field(FieldClass *field)
 {
 	field->Next = Head;
 	Head = field;
 }
 
 /**************************************************************************
  * PACKETCLASS::PACKETCLASS -- Creates a Packet object from a COMMS packe *
  *                                                                        *
  * INPUT:                                                                 *
  *                                                                        *
  * OUTPUT:                                                                *
  *                                                                        *
  * WARNINGS:                                                              *
  *                                                                        *
  * HISTORY:                                                               *
  *   04/22/1996 PWG : Created.                                            *
  *========================================================================*/
 PacketClass::PacketClass(char *curbuf)
 {
 	int remaining_size;
 	//
 	// Pull the size and packet ID out of the linear packet stream.
 	//
 	Size = *(unsigned short *)curbuf;
 	curbuf += sizeof (unsigned short);
 	Size = ntohs(Size);
 	ID	  = *(short *)curbuf;
 	curbuf += sizeof (short);
 	ID   = ntohs(ID);
 	Head = NULL;
 
 	//
 	// Calculate the remaining size so that we can loop through the
 	//   packets and extract them.
 	//
 	remaining_size = Size - 4;
 
 	//
 	// Loop through the linear packet until we run out of room and
 	// create a field for each.
 	//
 	while (remaining_size > 0) {
 		FieldClass *field = new FieldClass;
 
 		//
 		// Copy the adjusted header into the buffer and then advance the buffer
 		//
 		memcpy(field, curbuf, FIELD_HEADER_SIZE);
 		curbuf += FIELD_HEADER_SIZE;
 		remaining_size   -= FIELD_HEADER_SIZE;
 
 		//
 		// Copy the data into the buffer
 		//
 		int size			= ntohs(field->Size);
 		field->Data		= new char[size];
 		memcpy(field->Data, curbuf, size);
 		curbuf			+= size;
 		remaining_size	-= size;
 		//
 		// Make sure we allow for the pad bytes.
 		//
 		int pad = (4 - (ntohs(field->Size) & 3)) & 3;
 		curbuf += pad;
 		remaining_size   -= pad;
 
 		//
 		// Convert the field back to the host format
 		//
 		field->Net_To_Host();
 
 		//
 		// Finally add the field to the field list in the packet
 		// structure.
 		//
 		Add_Field(field);
 	}
 }
 
 /**************************************************************************
  * CREATE_COMMS_PACKET -- Walks field list creating a packet              *
  *                                                                        *
  * INPUT:		short - the id of the packet so the server can identify it *
  *					unsigned short & - the size of the packet returned here    *
  *                                                                        *
  * OUTPUT:     void * pointer to the linear packet data                   *
  *                                                                        *
  * WARNINGS: 	This routine allocates memory that the user is responsible *
  *  				for freeing.															  *
  *                                                                        *
  * HISTORY:                                                               *
  *   04/22/1996 PWG : Created.                                            *
  *========================================================================*/
 char *PacketClass::Create_Comms_Packet(int &size)
 {
 	FieldClass *current;
 
 	//
 	// Size starts at four because that is the size of the packet header.
 	//
 	size = 4;
 
 	//
 	// Take a quick spin through and calculate the size of the packet we
 	//   are building.
 	//
 	for (current = Head; current; current=current->Next) {
 		size += (unsigned short)FIELD_HEADER_SIZE;			// add in packet header size
 		size += current->Size;				// add in data size
 		size += (4 - (size & 3)) & 3; 	// add in pad value to dword align next packet
 	}
 
 	//
 	// Now that we know the size allocate a buffer big enough to hold the
 	// packet.
 	//
 	char *retval = new char[size];
 	char *curbuf = retval;
 
 	//
 	// write the size into the packet header
 	//
 	*(unsigned short *)curbuf = (unsigned short)htons((unsigned short)size);
 	curbuf += sizeof (unsigned short);
 	*(short *)curbuf = htons(ID);
 	curbuf += sizeof (short);
 
 	//
 	// Ok now that the actual header information has been written we need to write out
 	// field information.
 	//
 	for (current = Head; current; current = current->Next) {
 		//
 		// Temporarily convert the packet to net format (this saves alot of
 		//   effort, and seems safe...)
 		//
 		current->Host_To_Net();
 
 		//
 		// Copy the adjusted header into the buffer and then advance the buffer
 		//
 		memcpy(curbuf, current, FIELD_HEADER_SIZE);
 		curbuf += FIELD_HEADER_SIZE;
 
 		//
 		// Copy the data into the buffer and then advance the buffer
 		//
 		memcpy(curbuf, current->Data, ntohs(current->Size));
 		curbuf += ntohs(current->Size);
 
 		//
 		// Finally take care of any pad bytes by setting them to 0
 		//
 		int pad = (4 - (ntohs(current->Size) & 3)) & 3;
 
 		//
 		//	If there is any pad left over, make sure you memset it
 		// to zeros, so it looks like a pad.
 		//
 		if (pad) {
 			memset(curbuf, 0, pad);
 			curbuf += pad;
 		}
 
 		current->Net_To_Host();
 	}
 	return(retval);
 }
 
 
 /**************************************************************************
  * PACKETCLASS::FIND_FIELD -- Finds a field if it exists in the packets   *
  *                                                                        *
  * INPUT:		char *  - the id of the field we are looking for.			  *
  *                                                                        *
  * OUTPUT:     FieldClass * pointer to the field class                    *
  *                                                                        *
  * HISTORY:                                                               *
  *   04/23/1996 PWG : Created.                                            *
  *========================================================================*/
 FieldClass *PacketClass::Find_Field(char *id)
 {
 	for (FieldClass *current = Head; current; current = current->Next) {
 		if ( strncmp(id, current->ID, 4) == 0)
 			return current;
 	}
 	return NULL;
 }
 
 
 /**************************************************************************
  * GET_FIELD -- Find specified name and returns data                      *
  *                                                                        *
  * INPUT:		char *   - the id of the field that holds the data.		  *
  *					char &   - the reference to store the data into				  *
  *                                                                        *
  * OUTPUT:		true if the field was found, false if it was not.			  *
  *                                                                        *
  * WARNINGS:	The data reference is not changed if the field is not		  *
  *					found.																	  *
  *                                                                        *
  * HISTORY:                                                               *
  *   04/23/1996 PWG : Created.                                            *
  *========================================================================*/
 bool PacketClass::Get_Field(char *id, char &data)
 {
 	FieldClass *field = Find_Field(id);
 	if (field) {
 		data = *((char *)field->Data);
 	}
 	return((field) ? true : false);
 }
 
 
 /**************************************************************************
  * GET_FIELD -- Find specified name and returns data                      *
  *                                                                        *
  * INPUT:		char *   - the id of the field that holds the data.		  *
  *					unsigned char &   - the reference to store the data into	  *
  *                                                                        *
  * OUTPUT:		true if the field was found, false if it was not.			  *
  *                                                                        *
  * WARNINGS:	The data reference is not changed if the field is not		  *
  *					found.																	  *
  *                                                                        *
  * HISTORY:                                                               *
  *   04/23/1996 PWG : Created.                                            *
  *========================================================================*/
 bool PacketClass::Get_Field(char *id, unsigned char &data)
 {
 	FieldClass *field = Find_Field(id);
 	if (field) {
 		data = *((unsigned char *)field->Data);
 	}
 	return((field) ? true : false);
 }
 
 
 /**************************************************************************
  * GET_FIELD -- Find specified name and returns data                      *
  *                                                                        *
  * INPUT:		char *   - the id of the field that holds the data.		  *
  *					short &   - the reference to store the data into	        *
  *                                                                        *
  * OUTPUT:		true if the field was found, false if it was not.			  *
  *                                                                        *
  * WARNINGS:	The data reference is not changed if the field is not		  *
  *					found.																	  *
  *                                                                        *
  * HISTORY:                                                               *
  *   04/23/1996 PWG : Created.                                            *
  *========================================================================*/
 bool PacketClass::Get_Field(char *id, short &data)
 {
 	FieldClass *field = Find_Field(id);
 	if (field) {
 		data = *((short *)field->Data);
 	}
 	return((field) ? true : false);
 }
 
 
 /**************************************************************************
  * GET_FIELD -- Find specified name and returns data                      *
  *                                                                        *
  * INPUT:		char *   - the id of the field that holds the data.		  *
  *					unsigned short &   - the reference to store the data into  *
  *                                                                        *
  * OUTPUT:		true if the field was found, false if it was not.			  *
  *                                                                        *
  * WARNINGS:	The data reference is not changed if the field is not		  *
  *					found.																	  *
  *                                                                        *
  * HISTORY:                                                               *
  *   04/23/1996 PWG : Created.                                            *
  *========================================================================*/
 bool PacketClass::Get_Field(char *id, unsigned short &data)
 {
 	FieldClass *field = Find_Field(id);
 	if (field) {
 		data = *((unsigned short *)field->Data);
 	}
 	return((field) ? true : false);
 }
 
 
 /**************************************************************************
  * GET_FIELD -- Find specified name and returns data                      *
  *                                                                        *
  * INPUT:		char *   - the id of the field that holds the data.		  *
  *					long &   - the reference to store the data into  			  *
  *                                                                        *
  * OUTPUT:		true if the field was found, false if it was not.			  *
  *                                                                        *
  * WARNINGS:	The data reference is not changed if the field is not		  *
  *					found.																	  *
  *                                                                        *
  * HISTORY:                                                               *
  *   04/23/1996 PWG : Created.                                            *
  *========================================================================*/
 bool PacketClass::Get_Field(char *id, long &data)
 {
 	FieldClass *field = Find_Field(id);
 	if (field) {
 		data = *((long *)field->Data);
 	}
 	return((field) ? true : false);
 }
 
 /**************************************************************************
  * GET_FIELD -- Find specified name and returns data as a string          *
  *                                                                        *
  * INPUT:		char *   - the id of the field that holds the data.		  *
  *					char *   - the string to store the data into					  *
  *                                                                        *
  * OUTPUT:		true if the field was found, false if it was not.			  *
  *                                                                        *
  * WARNINGS:	The string is not changed if the field is not found.  It   *
  *					is assumed that the string variabled specified by the      *
  *					pointer is large enough to hold the data.						  *
  *                                                                        *
  * HISTORY:                                                               *
  *   04/23/1996 PWG : Created.                                            *
  *========================================================================*/
 #pragma warning(disable:4996)
 bool PacketClass::Get_Field(char *id, char *data)
 {
 	FieldClass *field = Find_Field(id);
 	if (field) {
 		strcpy(data, (char *)field->Data);
 	}
 	return((field) ? true : false);
 }
 
 /**************************************************************************
  * GET_FIELD -- Find specified name and returns data                      *
  *                                                                        *
  * INPUT:		char *   - the id of the field that holds the data.		  *
  *					unsigned long &   - the reference to store the data into   *
  *                                                                        *
  * OUTPUT:		true if the field was found, false if it was not.			  *
  *                                                                        *
  * WARNINGS:	The data reference is not changed if the field is not		  *
  *					found.																	  *
  *                                                                        *
  * HISTORY:                                                               *
  *   04/23/1996 PWG : Created.                                            *
  *========================================================================*/
 bool PacketClass::Get_Field(char *id, unsigned long &data)
 {
 	FieldClass *field = Find_Field(id);
 	if (field) {
 		data = *((unsigned long *)field->Data);
 	}
 	return((field) ? true : false);
 }
 
 
 /**************************************************************************
  * GET_FIELD -- Find specified name and returns data                      *
  *                                                                        *
  * INPUT:		char *   - the id of the field that holds the data.		    *
  *				void * - the reference to store the data into                *
  *           int    - the length of the buffer passed in                  *
  *                                                                        *
  * OUTPUT:		true if the field was found, false if it was not.			 *
  *                                                                        *
  * WARNINGS:	The data reference is not changed if the field is not		    *
  *					found.																	 *
  *                                                                        *
  * HISTORY:                                                               *
  *   6/4/96 4:46PM ST : Created                                           *
  *========================================================================*/
 bool PacketClass::Get_Field(char *id, void *data, int &length)
 {
 	FieldClass *field = Find_Field(id);
 	if (field) {
 		memcpy (data, field->Data, min(field->Size, length));
 		length = (int) field->Size;
 	}
 	return((field) ? true : false);
 }