serv.c

Introduction to the Transport Device Interface-f

/**********************************************************************
 * 
 *  Toby Opferman
 *
 * Chat Server using Winsock
 *
 *  This example is for educational purposes only.  I license this source
 *  out for use in learning how to write a device driver.
 *
 *  Copyright (c) 2005, All Rights Reserved  
 **********************************************************************/



#include <windows.h>
#include <winsock.h>
#include <stdio.h>
#include <stdlib.h>
#include <conio.h>



/**********************************************************************
 * Internal Data Structures
 **********************************************************************/
 typedef struct _client_info
  {
     SOCKET hSocket;
     SOCKADDR_IN SockAddr;
     char Nick[12];
     BOOL bSetNick;
     struct _client_info *Next;

 } CLIENT_INFO, *PCLIENT_INFO;

 typedef struct _server_info
 {
    SOCKET hServerSocket;
    PCLIENT_INFO pClientInfoList;
    fd_set stReadFDS, stXcptFDS;
    int DataSockets;
    BOOL bServerIsRunning;

 } SERVER_INFO, *PSERVER_INFO;
 
 typedef enum 
 {
     SERV_WINSOCK_INIT_ERROR = 1,
     SERV_WINSOCK_SOCKET_ERROR,
     SERV_WINSOCK_BIND_ERROR,
     SERV_WINSOCK_LISTEN_ERROR,
     SERV_WINSOCK_LOCALIP_ERROR,
     SERV_MEMORY_ERROR

 } SERV_ERROR;

/**********************************************************************
 * Internal Prototypes
 **********************************************************************/
 BOOL Serv_InitializeWinsock(void);
 SOCKET Serv_CreateServer(void);
 void Serv_RunServer(SOCKET hServerSocket);
 void Serv_DisplayErrorMsg(SERV_ERROR uiMsg);
 void Serv_FreeWinsock(void);
 BOOL Serv_DisplayLocalIp(SOCKADDR_IN *SockAddr);
 void Serv_ProcessIncommingSockets(PSERVER_INFO pServerInfo);
 void Serv_ProcessChatBroadcast(PSERVER_INFO pServerInfo);
 BOOL Serv_ProcessSocketWait(PSERVER_INFO pServerInfo);
 void Serv_SendNewClientBroadCast(SOCKET hClientSocket, PSERVER_INFO pServerInfo);
 PCLIENT_INFO Serv_CreateNewClient(SOCKET hNewClientSocket, SOCKADDR_IN *pNewClientSockAddr);
 void Serv_SendClientBroadCast(PCLIENT_INFO pClientInfo, PSERVER_INFO pServerInfo, char *pszBuffer);
 void Serv_FreeClientList(PSERVER_INFO pServerInfo);

/**********************************************************************
 * 
 *  main
 *
 *    Console App Entry Function
 *
 **********************************************************************/
 int __cdecl main(void)
 {
     if(Serv_InitializeWinsock())
     {
         SOCKET hServSocket;

         hServSocket = Serv_CreateServer();

         if(hServSocket != INVALID_SOCKET)
         {
             Serv_RunServer(hServSocket);
         }

         Serv_FreeWinsock();
     }

     return 0;
 }

/**********************************************************************
 * 
 *  Serv_InitializeWinsock
 *
 *    Initialize Winsock
 *
 **********************************************************************/
 BOOL Serv_InitializeWinsock(void)
 {
     BOOL bInitialized = FALSE;
     WSADATA WsaData;

     if(WSAStartup(MAKEWORD(1, 1), &WsaData) != 0)
     {
        Serv_DisplayErrorMsg(SERV_WINSOCK_INIT_ERROR);
     }
     else
     {
         bInitialized = TRUE;
     }

     return bInitialized;
 }


/**********************************************************************
 * 
 *  Serv_FreeWinsock
 *
 *    Free Winsock
 *
 **********************************************************************/
 void Serv_FreeWinsock(void)
 {
     WSACleanup();
 }


/**********************************************************************
 * 
 *  Serv_DisplayErrorMsg
 *
 *    Displays Error Messages
 *
 **********************************************************************/ 
 void Serv_DisplayErrorMsg(SERV_ERROR uiMsg)
 {
     switch(uiMsg)
     {
         case SERV_WINSOCK_INIT_ERROR:
              printf("Chat Server - Cannot Initialize Winsock!\n");
              break;

         case SERV_WINSOCK_SOCKET_ERROR:
              printf("Chat Server - Cannot Create Socket!\n");
              break;

         case SERV_WINSOCK_BIND_ERROR:
              printf("Chat Server - Cannot Bind Socket to Port!\n");
              break;

         case SERV_WINSOCK_LISTEN_ERROR:
              printf("Chat Server - Cannot Listen on Port!\n");
              break;
     
         case SERV_WINSOCK_LOCALIP_ERROR:
              printf("Chat Server - Cannot Find Local IP Address!\n");
              break;

         case SERV_MEMORY_ERROR:
              printf("Chat Server - Out of Memory!\n");
              break;
              
         default:
              printf("Chat Server - Runtime Error!\n");

     }
 }


/**********************************************************************
 * 
 *  Serv_CreateServer
 *
 *    Creates the Listener
 *
 **********************************************************************/
 SOCKET Serv_CreateServer(void)
 {
    SOCKET hSocket = INVALID_SOCKET;
    SOCKADDR_IN SockAddr = {0};
    UINT uiErrorStatus;

    /*
     * Create a socket
     */
    hSocket = socket(PF_INET, SOCK_STREAM, 0);

    if(hSocket != INVALID_SOCKET)
    {

    
        SockAddr.sin_family = PF_INET;
        SockAddr.sin_port = htons(4000);

        /*
         * BIND the Socket to a Port
         */
        uiErrorStatus = bind(hSocket, (struct sockaddr *)&SockAddr, sizeof(SOCKADDR_IN));
         
        if(uiErrorStatus != INVALID_SOCKET)
        {
            /*
             * Start Listening
             */

            if(listen(hSocket, 5) == 0)
            {
                /*
                 * Display Local IP Address
                 */
                if(Serv_DisplayLocalIp(&SockAddr) == FALSE)
                {
                      Serv_DisplayErrorMsg(SERV_WINSOCK_LOCALIP_ERROR);
                      closesocket(hSocket);
                      hSocket = INVALID_SOCKET;
                }

            }
            else
            {
                Serv_DisplayErrorMsg(SERV_WINSOCK_LISTEN_ERROR);
                closesocket(hSocket);
                hSocket = INVALID_SOCKET;
            }
        }
        else
        {
            Serv_DisplayErrorMsg(SERV_WINSOCK_BIND_ERROR);
            closesocket(hSocket);
            hSocket = INVALID_SOCKET;
        }
    }
    else
    {
        Serv_DisplayErrorMsg(SERV_WINSOCK_SOCKET_ERROR);
    }

    return hSocket;
 }


/**********************************************************************
 * 
 *  Serv_DisplayLocalIp
 *
 *    Displays a Local IP Address using a socket structure
 *
 **********************************************************************/
 BOOL Serv_DisplayLocalIp(SOCKADDR_IN *SockAddr)
 {
    BOOL bDisplayedLocalIp = FALSE;
    char HostName[101];
    LPHOSTENT Host;

    /*
     * If the Local IP Address is not in the SOCKADDR data structure, then
     * attempt to find it.
     */
    if(!SockAddr->sin_addr.s_addr)
    {
          if(gethostname(HostName, 100) != SOCKET_ERROR)
          {
              Host = gethostbyname((LPSTR)HostName);
                                 
              if(Host)
              {
                  SockAddr->sin_addr.s_addr = *((long *)Host->h_addr);
              }
                                           
              if(SockAddr->sin_addr.s_addr)
              {
                    printf("Server IP Address = %i.%i.%i.%i\n", SockAddr->sin_addr.s_addr&0xFF,
                                                                SockAddr->sin_addr.s_addr>>8 & 0xFF,
                                                                SockAddr->sin_addr.s_addr>>16 & 0xFF,
                                                                SockAddr->sin_addr.s_addr>>24 & 0xFF);

                    printf("Server Port Number = %i\n", htons(SockAddr->sin_port));

                    bDisplayedLocalIp = TRUE;
              }
 
          }
    }
    else
    {
        bDisplayedLocalIp = TRUE;
        printf("Server IP Address = %i.%i.%i.%i\n", SockAddr->sin_addr.s_addr&0xFF,
                                           SockAddr->sin_addr.s_addr>>8 & 0xFF,
                                           SockAddr->sin_addr.s_addr>>16 & 0xFF,
                                           SockAddr->sin_addr.s_addr>>24 & 0xFF);
        printf("Server Port Number = %i\n", htons(SockAddr->sin_port));                
    }

    return bDisplayedLocalIp;
 }



 /**********************************************************************
 * 
 *  Serv_RunServer
 *
 *    Runs the server
 *
 **********************************************************************/
 void Serv_RunServer(SOCKET hServerSocket)
 {
     SERVER_INFO ServerInfo = {0};

     printf("Toby Opferman's Simple Chat Broadcast Server Example is Running\n");
     printf("Type 'Q' to Quit\n");

     ServerInfo.hServerSocket    = hServerSocket;
     ServerInfo.bServerIsRunning = TRUE;

     while(ServerInfo.bServerIsRunning)
     {
          if(Serv_ProcessSocketWait(&ServerInfo))
          {
              Serv_ProcessIncommingSockets(&ServerInfo);
              Serv_ProcessChatBroadcast(&ServerInfo);
          }
     }