MultiThreaed Client Server Communication

// Server.cpp : Defines the entry point for the application.
//

#include "stdafx.h"
#include "resource.h"
#include <winsock.h>

//function declaration
DWORD WINAPI ValidateData(LPVOID Parameter);

int APIENTRY WinMain(HINSTANCE hInstance,
                     HINSTANCE hPrevInstance,
                     LPSTR     lpCmdLine,
                     int       nCmdShow)
{
 	WORD sockVersion;	//Used to store socket version information
	WSADATA wsaData;	//used to store info about socket
	SOCKET s,client;	//used to create client and server socket
	SOCKADDR_IN sin;	//used to specify a local or remote endpoint address to which to connect a socket
	int rVal;	//used to store return value
	
	HANDLE hThread;	//Handle to thread
	DWORD ThreadId;	//used to store the thread id
	
	//Get the current socket version
	sockVersion = MAKEWORD(1,1);
	
	//The Windows Sockets WSAStartup function initiates use of WS2_32.DLL by a process
	WSAStartup(sockVersion, &wsaData);
	//here we are creating the socket
	s = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
	if(s == INVALID_SOCKET)
	{
		MessageBox(0,"Invalid socket","Socket Error",MB_OK);
		WSACleanup();
	}
	//fill in sockaddr_in struct 
	sin.sin_family = PF_INET;
	sin.sin_port = htons(8888);
	sin.sin_addr.s_addr = INADDR_ANY;
	
	//bind to the socket
	rVal = bind(s, (LPSOCKADDR)&sin, sizeof(sin));
	if(rVal == SOCKET_ERROR)
	{
		MessageBox(0,"Failed in bind API","Bind Error",MB_OK);
		WSACleanup();
	}

	//Listen to the desire port on which client suppose to connect
	rVal = listen(s, 2);
	if(rVal == SOCKET_ERROR)
	{
		MessageBox(0,"Failed in listen API","Listen Error",MB_OK);
		WSACleanup();
	}
	//infinite loop to serve all the clients which want service
	while(1)
	{
		//Accept the data from the client
		client = accept(s, NULL, NULL);

		//Once the new client come up create a new thread t serve the client
		if(client)
		{
			hThread = CreateThread(NULL,
                            0,
							ValidateData,
                            (LPVOID)client,
                            0,
                            &ThreadId);
		}
		else
			return 0;
	}
	return 0;
}

////////////////////////////////////////////////////////////////////////
// ValidateData
//
//	Function to serve client request
//	In this function i am doing a simple check 
//  like string comparision(for simpicity)
//  you can do your own data validation here
//
/*********************************************
*	Autohor			:	Vishal 
*	Function Name	:	ValidateData
*	Created on		:	19-December-04
*	Last Modified	:	24-December-04
*	Organisation	:	Codeproject.com
*********************************************/
DWORD WINAPI ValidateData(LPVOID Parameter)
{
	//Get the information about client entity
	SOCKET client = (SOCKET)Parameter;
	int rVal;	//Return val
	char buf[11];	//used to send the validated data to client

	//Get the data form client
	rVal = recv(client,buf,11,0);
	//here we are performing simple check, the data came form client
	//is valid or not
	//at this point you can check your own data also, which needs some modification
	if(strcmp(buf,"Data On Socket"))
	{
		//Send back the data to the client
		rVal = send(client,"YES",3,0);
	}
	else
	{
		//Send back the data to the client
		rVal = send(client,"NO",2,0);
	}
	return 0;
}