Source code of Windows XP (NT5)
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/*++
Copyright (c) 1998, Microsoft Corporation
Module Name:
notify.c
Abstract:
This module contains code related to the NAT's notification-management.
Notification may be requested by a NAT user- or kernel-mode client,
by making an I/O control request which will complete when
(a) the requested event occurs, or
(b) the client's file-object is cleaned up, or
(c) the NAT is shutting down.
In the meantime, the I/O request packets are held on a list of pending
notification-requests.
Author:
Abolade Gbadegesin (aboladeg) July-26-1998
Revision History:
--*/
#include "precomp.h"
#pragma hdrstop
LIST_ENTRY NotificationList;
KSPIN_LOCK NotificationLock;
//
// FORWARD DECLARATIONS
//
VOID
NatpNotificationCancelRoutine(
PDEVICE_OBJECT DeviceObject,
PIRP Irp
);
PIRP
NatpDequeueNotification(
IP_NAT_NOTIFICATION Code
);
VOID
NatCleanupAnyAssociatedNotification(
PFILE_OBJECT FileObject
)
/*++
Routine Description:
This routine is invoked to cleanup any notifications associated with
the client whose file-object has just been closed.
Arguments:
FileObject - the client's file-object
Return Value:
none.
--*/
{
PIRP Irp;
KIRQL Irql;
PLIST_ENTRY Link;
CALLTRACE(("NatCleanupAnyAssociatedNotification\n"));
KeAcquireSpinLock(&NotificationLock, &Irql);
for (Link = NotificationList.Flink;
Link != &NotificationList;
Link = Link->Flink
) {
Irp = CONTAINING_RECORD(Link, IRP, Tail.Overlay.ListEntry);
if (Irp->Tail.Overlay.DriverContext[0] != FileObject) { continue; }
if (NULL == IoSetCancelRoutine(Irp, NULL)) {
//
// This IRP has been canceled. It will be completed in
// our cancel routine
//
continue;
}
//
// The IRP is now uncancellable. Take it off the list.
//
RemoveEntryList(&Irp->Tail.Overlay.ListEntry);
InitializeListHead(&Irp->Tail.Overlay.ListEntry);
KeReleaseSpinLockFromDpcLevel(&NotificationLock);
//
// Complete the IRP
//
Irp->IoStatus.Status = STATUS_CANCELLED;
Irp->IoStatus.Information = 0;
IoCompleteRequest(Irp, IO_NO_INCREMENT);
DEREFERENCE_NAT();
//
// Continue the search, starting over since we dropped the list lock
//
KeAcquireSpinLockAtDpcLevel(&NotificationLock);
Link = &NotificationList;
}
KeReleaseSpinLock(&NotificationLock, Irql);
} // NatCleanupAnyAssociatedNotification
VOID
NatInitializeNotificationManagement(
VOID
)
/*++
Routine Description:
This routine is called to initialize the notification-management module.
Arguments:
none.
Return Value:
none.
--*/
{
CALLTRACE(("NatInitializeNotificationManagement\n"));
InitializeListHead(&NotificationList);
KeInitializeSpinLock(&NotificationLock);
} // NatInitializeNotificationManagement
PIRP
NatpDequeueNotification(
IP_NAT_NOTIFICATION Code
)
/*++
Routine Description:
This routine is invoked to dequeue a pending notification request IRP
of the given type. If one is found, it is removed from the list
and returned to the caller.
Arguments:
Code - the notification code for which an IRP is required
Return Value:
PIRP - the notification IRP, if any
Environment:
Invoked with 'NotificationLock' held by the caller.
--*/
{
PIRP Irp;
PLIST_ENTRY Link;
PIP_NAT_REQUEST_NOTIFICATION RequestNotification;
CALLTRACE(("NatpDequeueNotification\n"));
for (Link = NotificationList.Flink;
Link != &NotificationList;
Link = Link->Flink
) {
Irp = CONTAINING_RECORD(Link, IRP, Tail.Overlay.ListEntry);
RequestNotification =
(PIP_NAT_REQUEST_NOTIFICATION)Irp->AssociatedIrp.SystemBuffer;
if (RequestNotification->Code != Code) { continue; }
RemoveEntryList(&Irp->Tail.Overlay.ListEntry);
InitializeListHead(&Irp->Tail.Overlay.ListEntry);
return Irp;
}
return NULL;
} // NatpDequeueNotification
VOID
NatpNotificationCancelRoutine(
PDEVICE_OBJECT DeviceObject,
PIRP Irp
)
/*++
Routine Description:
This routine is invoked by the I/O manager upon cancellation of an IRP
that is associated with a notification.
Arguments:
DeviceObject - the NAT's device-object
Irp - the IRP to be cancelled
Return Value:
none.
Environment:
Invoked with the cancel spin-lock held by the I/O manager.
It is this routine's responsibility to release the lock.
--*/
{
KIRQL Irql;
CALLTRACE(("NatpNotificationCancelRoutine\n"));
IoReleaseCancelSpinLock(Irp->CancelIrql);
//
// Take the IRP off our list
//
KeAcquireSpinLock(&NotificationLock, &Irql);
RemoveEntryList(&Irp->Tail.Overlay.ListEntry);
InitializeListHead(&Irp->Tail.Overlay.ListEntry);
KeReleaseSpinLock(&NotificationLock, Irql);
//
// Complete the IRP
//
Irp->IoStatus.Status = STATUS_CANCELLED;
Irp->IoStatus.Information = 0;
IoCompleteRequest(Irp, IO_NO_INCREMENT);
DEREFERENCE_NAT();
} // NatpNotificationCancelRoutine
NTSTATUS
NatRequestNotification(
PIP_NAT_REQUEST_NOTIFICATION RequestNotification,
PIRP Irp,
PFILE_OBJECT FileObject
)
/*++
Routine Description:
This routine is invoked upon receipt of a notification-request
from a client.
Arguments:
RequeustNotification - describes the notification
Irp - the associated IRP
FileObject - the client's file-object
Return Value:
NTSTATUS - status code.
--*/
{
KIRQL CancelIrql;
PIO_STACK_LOCATION IrpSp;
CALLTRACE(("NatRequestNotification\n"));
//
// Check the size of the supplied output-buffer
//
IrpSp = IoGetCurrentIrpStackLocation(Irp);
if (RequestNotification->Code == NatRoutingFailureNotification) {
if (IrpSp->Parameters.DeviceIoControl.OutputBufferLength <
sizeof(IP_NAT_ROUTING_FAILURE_NOTIFICATION)) {
return STATUS_INVALID_BUFFER_SIZE;
}
} else {
return STATUS_INVALID_PARAMETER;
}
//
// Attempt to queue the IRP for later completion.
// If the IRP is already cancelled, though, do nothing
//
IoAcquireCancelSpinLock(&CancelIrql);
KeAcquireSpinLockAtDpcLevel(&NotificationLock);
if (Irp->Cancel || !REFERENCE_NAT()) {
KeReleaseSpinLockFromDpcLevel(&NotificationLock);
IoReleaseCancelSpinLock(CancelIrql);
return STATUS_CANCELLED;
}
//
// Put the IRP on the list and remember its file-object
//
InsertTailList(&NotificationList, &Irp->Tail.Overlay.ListEntry);
Irp->Tail.Overlay.DriverContext[0] = FileObject;
KeReleaseSpinLockFromDpcLevel(&NotificationLock);
//
// Install our cancel-routine
//
IoMarkIrpPending(Irp);
IoSetCancelRoutine(Irp, NatpNotificationCancelRoutine);
IoReleaseCancelSpinLock(CancelIrql);
return STATUS_PENDING;
} // NatRequestNotification
VOID
NatSendRoutingFailureNotification(
ULONG DestinationAddress,
ULONG SourceAddress
)
/*++
Routine Description:
This routine is invoked to notify any clients that a routing failure has
occurred.
Arguments:
DestinationAddress - the destination address of the unroutable packet
SourceAddress - the source address of the unroutable packet
Return Value:
none.
--*/
{
PIRP Irp;
KIRQL Irql;
PIP_NAT_ROUTING_FAILURE_NOTIFICATION RoutingFailureNotification;
CALLTRACE(("NatSendRoutingFailureNotification\n"));
//
// See if any client wants routing-failure notification
//
KeAcquireSpinLock(&NotificationLock, &Irql);
if (!(Irp = NatpDequeueNotification(NatRoutingFailureNotification))) {
KeReleaseSpinLock(&NotificationLock, Irql);
return;
}
KeReleaseSpinLock(&NotificationLock, Irql);
//
// Make the IRP uncancellable so we can complete it.
//
if (NULL == IoSetCancelRoutine(Irp, NULL)) {
//
// The IO manager canceled this IRP. It will be completed
// in the cancel routine
//
return;
}
//
// Fill in the notification information
//
RoutingFailureNotification =
(PIP_NAT_ROUTING_FAILURE_NOTIFICATION)Irp->AssociatedIrp.SystemBuffer;
RoutingFailureNotification->DestinationAddress = DestinationAddress;
RoutingFailureNotification->SourceAddress = SourceAddress;
//
// Complete the IRP
//
Irp->IoStatus.Status = STATUS_SUCCESS;
Irp->IoStatus.Information = sizeof(*RoutingFailureNotification);
IoCompleteRequest(Irp, IO_NO_INCREMENT);
DEREFERENCE_NAT();
} // NatSendRoutingFailureNotification
VOID
NatShutdownNotificationManagement(
VOID
)
/*++
Routine Description:
This routine is invoked to shut down the module.
All outstanding notifications are cancelled.
Arguments:
none.
Return Value:
none.
--*/
{
PIRP Irp;
PLIST_ENTRY Link;
KIRQL Irql;
CALLTRACE(("NatShutdownNotificationManagement\n"));
KeAcquireSpinLock(&NotificationLock, &Irql);
while (!IsListEmpty(&NotificationList)) {
//
// Take the next IRP off the list
//
Irp =
CONTAINING_RECORD(
NotificationList.Flink, IRP, Tail.Overlay.ListEntry
);
RemoveEntryList(&Irp->Tail.Overlay.ListEntry);
InitializeListHead(&Irp->Tail.Overlay.ListEntry);
//
// Cancel it if necessary
//
if (NULL != IoSetCancelRoutine(Irp, NULL)) {
KeReleaseSpinLockFromDpcLevel(&NotificationLock);
//
// Complete the IRP
//
Irp->IoStatus.Status = STATUS_CANCELLED;
Irp->IoStatus.Information = 0;
IoCompleteRequest(Irp, IO_NO_INCREMENT);
DEREFERENCE_NAT();
//
// Resume emptying the list
//
KeAcquireSpinLockAtDpcLevel(&NotificationLock);
}
}
KeReleaseSpinLock(&NotificationLock, Irql);
} // NatShutdownNotificationManagement