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IOCTL_SERIAL_GET_COMMSTATUS request flood in usage of hyperterminal RRS feed

  • Question

  • Hi ,

    I am developing a virtual serial device and I am able to talk to virtual device through hyperterminal, but I can only write once character. If I type second character, IOCTL_SERIAL_GET_COMMSTATUS requests are continuously coming to driver. 

    what could be the right way to handle this IOCTL request ?

    Thanks in Advance


    vidyasagar196

    Tuesday, October 18, 2016 5:31 PM

All replies

  • Yes, these show up. This request is used to determine if data is being held due to flow control. Just fill in the SERIAL_STATUS structure and complete the request

     -Brian


    Azius Developer Training www.azius.com Windows device driver, internals, security, & forensics training and consulting. Blog at www.azius.com/blog

    Tuesday, October 18, 2016 7:21 PM
    Moderator
  • Hi Brian,

    I am sending status, Please find the code

    PSerStatus = (PSERIAL_STATUS) buffer;
    PSerStatus->Errors = 0;
    PSerStatus->EofReceived = FALSE;
    PSerStatus->WaitForImmediate = 0;
    PSerStatus->HoldReasons = 0;
    PSerStatus->AmountInInQueue = 0;
    PSerStatus->AmountInOutQueue = 0;
    WdfRequestCompleteWithInformation(Request, STATUS_SUCCESS, sizeof(SERIAL_STATUS)); 


    vidyasagar196

    Tuesday, October 18, 2016 7:41 PM
  • OK, so what is the problem? You're going to see these periodically.

     -Brian


    Azius Developer Training www.azius.com Windows device driver, internals, security, & forensics training and consulting. Blog at www.azius.com/blog

    Tuesday, October 18, 2016 7:43 PM
    Moderator
  • Request flood occurs and ll not allow to write data to device

    vidyasagar196

    Tuesday, October 18, 2016 7:44 PM
  • Have you looked at the virtual serial driver in the WDK samples?

     -Brian


    Azius Developer Training www.azius.com Windows device driver, internals, security, & forensics training and consulting. Blog at www.azius.com/blog

    Thursday, October 20, 2016 7:02 PM
    Moderator