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#include <pch.h>
/*
** Driver TODO: Add logic to EvtIoRead to handle read requests from applications that don't use the Windows.Devices.PointOfService APIs.
**
** This is the callback for the IO queue that handles file read requests. In the POS magnetic
** stripe reader model, the application will always queue a read request in order to receive events
** such as the data received event, or the release-claim requested event.
**
** Note that apps that are developed against the Windows.Devices.PointOfService APIs will always
** expect event data to be returned by read requests. It is up to the driver to determine the
** behavior of ReadFile when the driver is opened by other types of applications.
*/
VOID EvtIoRead(_In_ WDFQUEUE Queue, _In_ WDFREQUEST Request, _In_ size_t Length)
{
NTSTATUS status;
WDFDEVICE device = WdfIoQueueGetDevice(Queue);
WDFFILEOBJECT fileObject = WdfRequestGetFileObject(Request);
UNREFERENCED_PARAMETER(Length);
// Check the flag that may have been set by PosCxMarkPosApp in Ioctl.cpp.
if (!PosCxIsPosApp(device, fileObject))
{
// An application has opened a handle to this device without using the Windows.Devices.PointOfService APIs.
// You may change this to handle the read request differently.
// In this example, just complete the read request with a failure.
WdfRequestComplete(Request, STATUS_UNSUCCESSFUL);
}
else
{
// If this returns success, it has taken ownership of Request
status = PosCxGetPendingEvent(device, Request);
if (!NT_SUCCESS(status))
{
WdfRequestComplete(Request, status);
}
}
}
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