169 lines
3.6 KiB
C
169 lines
3.6 KiB
C
/*
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* UNIMODEM "Fakemodem" controllerless driver illustrative example
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*
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* (C) 2000 Microsoft Corporation
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* All Rights Reserved
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*
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*/
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#include "fakemodem.h"
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NTSTATUS
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CheckStateAndAddReference(
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PDEVICE_OBJECT DeviceObject,
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PIRP Irp
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)
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{
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PDEVICE_EXTENSION DeviceExtension=(PDEVICE_EXTENSION)DeviceObject->DeviceExtension;
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KIRQL OldIrql;
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BOOLEAN DriverReady;
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InterlockedIncrement(&DeviceExtension->ReferenceCount);
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DriverReady=(!DeviceExtension->Removing) && (DeviceExtension->Started);
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if (!DriverReady) {
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//
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// driver not accepting requests
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//
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RemoveReferenceAndCompleteRequest( DeviceObject, Irp,
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STATUS_UNSUCCESSFUL);
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return STATUS_UNSUCCESSFUL;
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}
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InterlockedIncrement(&DeviceExtension->ReferenceCount);
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return STATUS_SUCCESS;
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}
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VOID
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RemoveReferenceAndCompleteRequest(
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PDEVICE_OBJECT DeviceObject,
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PIRP Irp,
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NTSTATUS StatusToReturn
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)
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{
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PDEVICE_EXTENSION DeviceExtension=(PDEVICE_EXTENSION)DeviceObject->DeviceExtension;
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KIRQL OldIrql;
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LONG NewReferenceCount;
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NewReferenceCount=InterlockedDecrement(&DeviceExtension->ReferenceCount);
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if (NewReferenceCount == 0) {
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//
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// device is being removed, set event
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//
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ASSERT(DeviceExtension->Removing);
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D_PNP(DbgPrint("FAKEMODEM: RemoveReferenceAndCompleteRequest: setting event\n");)
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KeSetEvent( &DeviceExtension->RemoveEvent, 0, FALSE);
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}
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Irp->IoStatus.Status = StatusToReturn;
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IoCompleteRequest( Irp, IO_SERIAL_INCREMENT);
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return;
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}
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VOID
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RemoveReference(
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PDEVICE_OBJECT DeviceObject
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)
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{
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PDEVICE_EXTENSION DeviceExtension=(PDEVICE_EXTENSION)DeviceObject->DeviceExtension;
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LONG NewReferenceCount;
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NewReferenceCount=InterlockedDecrement(&DeviceExtension->ReferenceCount);
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D_TRACE(
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if (DeviceExtension->Removing) {DbgPrint("FAKEMODEM: RemoveReference: %d\n",NewReferenceCount);}
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)
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if (NewReferenceCount == 0) {
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//
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// device is being removed, set event
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//
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ASSERT(DeviceExtension->Removing);
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D_PNP(DbgPrint("FAKEMODEM: RemoveReference: setting event\n");)
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KeSetEvent( &DeviceExtension->RemoveEvent, 0, FALSE);
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}
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return;
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}
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VOID
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FakeModemKillAllReadsOrWrites(
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IN PDEVICE_OBJECT DeviceObject,
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IN PLIST_ENTRY QueueToClean,
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IN PIRP *CurrentOpIrp
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)
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{
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KIRQL cancelIrql;
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PDRIVER_CANCEL cancelRoutine;
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IoAcquireCancelSpinLock(&cancelIrql);
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while (!IsListEmpty(QueueToClean))
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{
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PIRP currentLastIrp = CONTAINING_RECORD(
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QueueToClean->Blink, IRP, Tail.Overlay.ListEntry);
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RemoveEntryList(QueueToClean->Blink);
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cancelRoutine = currentLastIrp->CancelRoutine;
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currentLastIrp->CancelIrql = cancelIrql;
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currentLastIrp->CancelRoutine = NULL;
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currentLastIrp->Cancel = TRUE;
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cancelRoutine( DeviceObject, currentLastIrp);
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IoAcquireCancelSpinLock(&cancelIrql);
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}
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if (*CurrentOpIrp)
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{
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cancelRoutine = (*CurrentOpIrp)->CancelRoutine;
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(*CurrentOpIrp)->Cancel = TRUE;
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if (cancelRoutine)
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{
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(*CurrentOpIrp)->CancelRoutine = NULL;
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(*CurrentOpIrp)->CancelIrql = cancelIrql;
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cancelRoutine( DeviceObject, *CurrentOpIrp);
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} else
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{
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IoReleaseCancelSpinLock(cancelIrql);
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}
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} else
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{
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IoReleaseCancelSpinLock(cancelIrql);
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}
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}
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