client.c

Socket 编程的DOS下和Windows开发包 Microsoft TCP/IP SDK for DOS/Windows

                    lpProc = MakeProcInstance(AboutProc, hInst);
                    DialogBox(hInst, "AboutBox", hWnd, lpProc);
                    FreeProcInstance(lpProc);
                    break;

            }
            break;

	    
	case WM_TIMER:		         /* message: Timer message */
            if (nTest_state==XFER_ACTIVE) {
                data_xfer(hWnd); 
            }
            else {
	         MessageBox(hWnd, 
		 "state error, timer expired and not in XFER_ACTIVE state.",
		 "Error",
		  MB_OK);
	    } 
	    break;
	case WM_DESTROY:		  /* message: window being destroyed */
            if (nTest_state==XFER_ACTIVE)
                cleanup(hWnd);
	    PostQuitMessage(0);
	    break;

	default:			  /* Passes it on if unproccessed    */
	    return (DefWindowProc(hWnd, message, wParam, lParam));
    }
    return (NULL);
}

/**************************************************************************

    FUNCTION: cl_setup(HWND)

    PURPOSE:  Sets a timer, loads win_sock.dll, establishes a connection 
    to the server and sends the first buffer.

**************************************************************************/

VOID PASCAL cl_setup(hWnd)
HWND  hWnd;
{
    int    nRc, nLen, nK;
    struct hostent far *hp;
    struct sockaddr_in server_addr;

    /* Set timer to get control back at reqular intervals. */
    if (SetTimer(hWnd,1,TIMER_INTERVAL,NULL) == 0){
        MessageBox(hWnd, 
        "Help! Can't set timer.",
        "Error",
        MB_OK);
        return;
    }

    /* initialize the index to the screen output buffer */
    nI=0;

    /* create a socket */
    nSd= socket( AF_INET, SOCK_STREAM, 0);
    if (nSd < 0) {
        nTextlarr[nI]=sprintf(&szTextarr[nI][0],"socket call failed, error=%d",errno);
        inc_nI(hWnd);
        InvalidateRect(hWnd,NULL,TRUE);
        cleanup(hWnd);
        return;
    }

    /*
    ** Get IP address from host file.
    */
    hp = gethostbyname("win_server_node");
    if (hp == NULL ) {
        nTextlarr[nI]=sprintf(&szTextarr[nI][0],"win_server_node entry not in hosts file");
        inc_nI(hWnd);
        InvalidateRect(hWnd,NULL,TRUE);
        cleanup(hWnd);
        return;
    }

    /*
    ** Connect to remote socket at hard coded port.
    */
    server_addr.sin_family=AF_INET;
    server_addr.sin_port=htons(SRVPORT);       
    server_addr.sin_addr.s_addr=
              *( (unsigned long far *) hp->h_addr_list[0]);
    
    nRc=connect( nSd, (struct sockaddr far *) &server_addr,
                   sizeof(server_addr));
    if (nRc <0) {
        nTextlarr[nI]=sprintf(&szTextarr[nI][0],"Connect failed, error=%d",errno);
        inc_nI(hWnd);
        InvalidateRect(hWnd,NULL,TRUE);
        cleanup(hWnd);
        return;
    }

    /* initialize the packet  */
    for (nK=0; nK<BUFFER_SIZE; nK++) 
        sSendbuff[nK]=nK;

    /* send first data packet */
    sSendbuff[0]=DATA; 
    nLen = send( nSd, sSendbuff, BUFFER_SIZE, 0);
    if (nLen <0) {
        nTextlarr[nI]=sprintf(&szTextarr[nI][0],"error on first send,  error=%d",errno);
        inc_nI(hWnd);
        InvalidateRect(hWnd,NULL,TRUE);
        cleanup(hWnd);
        return;
    }
   
    nTotal_packets++; 
    nTextlarr[nI]=sprintf(&szTextarr[nI][0],"packet %d sent", nTotal_packets);
    inc_nI();
    InvalidateRect(hWnd,NULL,TRUE);

    nTest_state=XFER_ACTIVE;

}

/****************************************************************************

    FUNCTION: data_xfer(hWnd)

    PURPOSE: Does a receive and then a send.  After  a nTotal of 10 sends  
      and receives the cleanup routine is called.

****************************************************************************/
VOID PASCAL data_xfer(hWnd) 
HWND    hWnd;
{
    int nLen, nRc;
    int nTotal;
    int nK;
    long lIoctlarg; 

    /* check to see if there is anything to receive */
    nRc = ioctl(nSd,FIONREAD,(char * far) &lIoctlarg); 
    if (nRc <0) {
        nTextlarr[nI]=sprintf(&szTextarr[nI][0],"ioctl error=%d",errno);
        cleanup(hWnd);
        return;
    }
    if (lIoctlarg == 0) {
        nTextlarr[nI]=sprintf(&szTextarr[nI][0],"Waiting to receive packet.");
        inc_nI(hWnd);
        InvalidateRect(hWnd,NULL,TRUE);
        return;
    }

    /* receive packet */
    nTotal =0; 
    do {
        nLen = recv( nSd, &sRecvbuff[nTotal], BUFFER_SIZE-nTotal,
                       0);
        if ( nLen < 0 ) {
            /* break out of do while loop */
            break;
        } 
        nTotal += nLen;
    } while ( nTotal < BUFFER_SIZE );

    if (nLen <0)  {
        nTextlarr[nI]=sprintf(&szTextarr[nI][0],"Receive failed, error=%d",errno);
        inc_nI(hWnd);
        InvalidateRect(hWnd,NULL,TRUE);
        cleanup(hWnd);
        return;
    } /* if*/
    
    /*  Check to see if reached NUM_SENDS total packets. */
    if (nTotal_packets >= NUM_SENDS) {
        cleanup(hWnd);
        return;
    }

    /* Send the next packet. */
    nLen = send(nSd,sSendbuff,BUFFER_SIZE,0);
    if (nLen <0) {
        nTextlarr[nI]=sprintf(&szTextarr[nI][0],"send failed, error=%d",errno);
        inc_nI(hWnd);
        InvalidateRect(hWnd,NULL,TRUE);
        cleanup(hWnd);
        return;
    } /* if */

    /*  increment packets count */
    nTotal_packets++; 
   
    nTextlarr[nI]=sprintf(&szTextarr[nI][0],"packet %d sent", nTotal_packets);
    inc_nI();
    InvalidateRect(hWnd,NULL,TRUE);
}
/****************************************************************************

    FUNCTION: cleanup(HWND)

    PURPOSE:  Kills the timer, closes sockets, frees win_sock.dll
    and reinitializes state variables.


****************************************************************************/

VOID PASCAL cleanup(hWnd)
HWND   hWnd;
{
    int nRc, nLen;

    KillTimer(hWnd,1);

    nTest_state=NOT_STARTED;

    /* Send close packet.
    * note have to send sSendbuff size packet because the server is designed
    * to receive BUFFER_SIZE bytes of data and then check if it is
    * a close packet.
    */
    sSendbuff[0]=CLOSE; 
  
    /* send close packet */ 
    nLen = send( nSd, sSendbuff, BUFFER_SIZE, 0);
    if (nLen <0) {
        nTextlarr[nI]=sprintf(&szTextarr[nI][0],"send of close packet failed, error=%d",errno);
        inc_nI(hWnd);
        InvalidateRect(hWnd,NULL,TRUE);
    }

    nTextlarr[nI]=sprintf(&szTextarr[nI][0],"End of program. %d packets sent.",nTotal_packets);
    inc_nI();
    InvalidateRect(hWnd,NULL,TRUE);

    nRc= close_socket(
                        nSd,
                        );
    if (nRc <0) {
        nTextlarr[nI]=sprintf(&szTextarr[nI][0],"socket closed failed, error=%d",errno);
        inc_nI(hWnd);
        InvalidateRect(hWnd,NULL,TRUE);
    }
    nTotal_packets=0;
}
/****************************************************************************

    FUNCTION: About(HWND, unsigned, WORD, LONG)

    PURPOSE:  Processes messages for "About" dialog box

    MESSAGES:

        WM_INITDIALOG - initialize dialog box
        WM_COMMAND    - Input received

****************************************************************************/

BOOL FAR PASCAL AboutProc(hDlg, message, wParam, lParam)
HWND hDlg;
unsigned message;
WORD wParam;
LONG lParam;
{
    switch (message) {
        case WM_INITDIALOG:
            return (TRUE);

        case WM_COMMAND:
            if (wParam == IDOK
                || wParam == IDCANCEL) {
                EndDialog(hDlg, TRUE);
                return (TRUE);
            }
            return (TRUE);
    }
    return (FALSE);
}
/****************************************************************************

    FUNCTION: inc_nI

    PURPOSE: Increments the line number in the screen output buffer. 

****************************************************************************/
VOID PASCAL inc_nI() 
{
        if (nI <MAXLINES -1) {
                nI++;
        }
        else {
                nI++;
                /*InvalidateRect(hWnd,NULL,TRUE); */
                nI =0;
                nTextlarr[nI]=sprintf(&szTextarr[nI][0],"--wrapping around--");
                nI = 1;
        }
}