VOID
SDVTest_wdf_MarkCancOnCancReqDispatch(
_In_ WDFREQUEST Request
)
{
WdfRequestMarkCancelable(Request, SDVTest_EvtRequestCancel);
return;
}
VOID
EchoEvtIoWrite(
IN WDFQUEUE Queue,
IN WDFREQUEST Request,
IN size_t Length
)
/*++
Routine Description:
This event is invoked when the framework receives IRP_MJ_WRITE request.
This routine allocates memory buffer, copies the data from the request to it,
and stores the buffer pointer in the queue-context with the length variable
representing the buffers length. The actual completion of the request
is defered to the periodic timer dpc.
Arguments:
Queue - Handle to the framework queue object that is associated with the
I/O request.
Request - Handle to a framework request object.
Length - number of bytes to be read.
The default property of the queue is to not dispatch
zero lenght read & write requests to the driver and
complete is with status success. So we will never get
a zero length request.
Return Value:
VOID
--*/
{
NTSTATUS Status;
WDFMEMORY memory;
PQUEUE_CONTEXT queueContext = QueueGetContext(Queue);
PVOID writeBuffer = NULL;
_Analysis_assume_(Length > 0);
KdPrint(("EchoEvtIoWrite Called! Queue 0x%p, Request 0x%p Length %d\n",
Queue,Request,Length));
if( Length > MAX_WRITE_LENGTH ) {
KdPrint(("EchoEvtIoWrite Buffer Length to big %d, Max is %d\n",
Length,MAX_WRITE_LENGTH));
WdfRequestCompleteWithInformation(Request, STATUS_BUFFER_OVERFLOW, 0L);
return;
}
// Get the memory buffer
Status = WdfRequestRetrieveInputMemory(Request, &memory);
if( !NT_SUCCESS(Status) ) {
KdPrint(("EchoEvtIoWrite Could not get request memory buffer 0x%x\n",
Status));
WdfVerifierDbgBreakPoint();
WdfRequestComplete(Request, Status);
return;
}
// Release previous buffer if set
if( queueContext->WriteMemory != NULL ) {
WdfObjectDelete(queueContext->WriteMemory);
queueContext->WriteMemory = NULL;
}
Status = WdfMemoryCreate(WDF_NO_OBJECT_ATTRIBUTES,
NonPagedPool,
'sam1',
Length,
&queueContext->WriteMemory,
&writeBuffer
);
if(!NT_SUCCESS(Status)) {
KdPrint(("EchoEvtIoWrite: Could not allocate %d byte buffer\n", Length));
WdfRequestComplete(Request, STATUS_INSUFFICIENT_RESOURCES);
return;
}
// Copy the memory in
Status = WdfMemoryCopyToBuffer( memory,
0, // offset into the source memory
writeBuffer,
Length );
if( !NT_SUCCESS(Status) ) {
KdPrint(("EchoEvtIoWrite WdfMemoryCopyToBuffer failed 0x%x\n", Status));
WdfVerifierDbgBreakPoint();
WdfObjectDelete(queueContext->WriteMemory);
queueContext->WriteMemory = NULL;
WdfRequestComplete(Request, Status);
return;
}
// Set transfer information
WdfRequestSetInformation(Request, (ULONG_PTR)Length);
// Specify the request is cancelable
WdfRequestMarkCancelable(Request, EchoEvtRequestCancel);
// Defer the completion to another thread from the timer dpc
queueContext->CurrentRequest = Request;
queueContext->CurrentStatus = Status;
return;
}
VOID
EchoEvtIoRead(
IN WDFQUEUE Queue,
IN WDFREQUEST Request,
IN size_t Length
)
/*++
Routine Description:
This event is called when the framework receives IRP_MJ_READ request.
It will copy the content from the queue-context buffer to the request buffer.
If the driver hasn't received any write request earlier, the read returns zero.
Arguments:
Queue - Handle to the framework queue object that is associated with the
I/O request.
Request - Handle to a framework request object.
Length - number of bytes to be read.
The default property of the queue is to not dispatch
zero lenght read & write requests to the driver and
complete is with status success. So we will never get
a zero length request.
Return Value:
VOID
--*/
{
NTSTATUS Status;
PQUEUE_CONTEXT queueContext = QueueGetContext(Queue);
WDFMEMORY memory;
size_t writeMemoryLength;
_Analysis_assume_(Length > 0);
KdPrint(("EchoEvtIoRead Called! Queue 0x%p, Request 0x%p Length %d\n",
Queue,Request,Length));
//
// No data to read
//
if( (queueContext->WriteMemory == NULL) ) {
WdfRequestCompleteWithInformation(Request, STATUS_SUCCESS, (ULONG_PTR)0L);
return;
}
//
// Read what we have
//
WdfMemoryGetBuffer(queueContext->WriteMemory, &writeMemoryLength);
_Analysis_assume_(writeMemoryLength > 0);
if( writeMemoryLength < Length ) {
Length = writeMemoryLength;
}
//
// Get the request memory
//
Status = WdfRequestRetrieveOutputMemory(Request, &memory);
if( !NT_SUCCESS(Status) ) {
KdPrint(("EchoEvtIoRead Could not get request memory buffer 0x%x\n", Status));
WdfVerifierDbgBreakPoint();
WdfRequestCompleteWithInformation(Request, Status, 0L);
return;
}
// Copy the memory out
Status = WdfMemoryCopyFromBuffer( memory, // destination
0, // offset into the destination memory
WdfMemoryGetBuffer(queueContext->WriteMemory, NULL),
Length );
if( !NT_SUCCESS(Status) ) {
KdPrint(("EchoEvtIoRead: WdfMemoryCopyFromBuffer failed 0x%x\n", Status));
WdfRequestComplete(Request, Status);
return;
}
// Set transfer information
WdfRequestSetInformation(Request, (ULONG_PTR)Length);
// Mark the request is cancelable
WdfRequestMarkCancelable(Request, EchoEvtRequestCancel);
// Defer the completion to another thread from the timer dpc
queueContext->CurrentRequest = Request;
queueContext->CurrentStatus = Status;
return;
}
