449 lines
12 KiB
C
449 lines
12 KiB
C
/*++
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Copyright (c) 1989 Microsoft Corporation
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Module Name:
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recursvc.c
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Abstract:
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This module implements the recurrent services in the mini rdr. These are services that
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are not triggered as a response to some request from the wrapper, they are autonomous
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services that aid in the functioning of the mini redirector.
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Scavenging -- The construction of the SMB mini redirector counterparts to SRV_CALL,
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NET_ROOT and V_NET_ROOT involve network traffic. Therefore the SMB mini redirector
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introduces a hystersis between the deletion of the data structures by the wrapper and
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effecting those changes in the mini redirector data structures and the remote server.
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This is done by transitioning the deleted data structures to a dormant state and
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scavenging them after a suitable interval( approximately 45 sec).
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Probing Servers -- Sometimes the server response to a client request is delayed. The
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mini redirector has a probing mechanism which enables it to cope with overloaded
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servers. When a response is not forthcoming from a server it sends it an ECHO SMB.
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Since the server can respond to an ECHO SMB without having to commit many resources,
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a reply to the ECHO SMB is interpreted as a sign that the server is indeed alive and
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well.
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Author:
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Balan Sethu Raman [SethuR] 7-March-1995
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Revision History:
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Notes:
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A recurrent service can be either periodic or aperiodic. The periodic services are
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triggered at regular time intervals. These services then perform some tasks if
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required. The advantage of having periodic recurrent services is the guarantee that
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work will get done and the disadvantage is that it consumes system resources when
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there is no work to be done. Also if the handling time happens to straddle the
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service time period multiple threads wil
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An aperiodic recurrent service is a one shot mechanism. The service once invoked gets
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to decide when the next invocation will be. The advantage of such services is that
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it provides an inbuilt throttling mechanism.
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--*/
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#include "precomp.h"
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#pragma hdrstop
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#ifdef ALLOC_PRAGMA
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#pragma alloc_text(PAGE, MRxSmbInitializeRecurrentService)
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#pragma alloc_text(PAGE, MRxSmbCancelRecurrentService)
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#pragma alloc_text(PAGE, MRxSmbActivateRecurrentService)
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#pragma alloc_text(PAGE, MRxSmbInitializeRecurrentServices)
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#pragma alloc_text(PAGE, MRxSmbTearDownRecurrentServices)
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#pragma alloc_text(PAGE, MRxSmbInitializeScavengerService)
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#pragma alloc_text(PAGE, MRxSmbTearDownScavengerService)
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#endif
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MRXSMB_ECHO_PROBE_SERVICE_CONTEXT MRxSmbEchoProbeServiceContext;
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MRXSMB_SCAVENGER_SERVICE_CONTEXT MRxSmbScavengerServiceContext;
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extern VOID
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MRxSmbRecurrentServiceDispatcher(
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PVOID pContext);
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VOID
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MRxSmbInitializeRecurrentService(
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PRECURRENT_SERVICE_CONTEXT pRecurrentServiceContext,
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PRECURRENT_SERVICE_ROUTINE pServiceRoutine,
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PVOID pServiceRoutineParameter,
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PLARGE_INTEGER pTimeInterval)
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/*++
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Routine Description:
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This routine initializes a recurrent service
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Arguments:
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pRecurrentServiceContext - the recurrent service to be initialized
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pServiceRoutine - the recurrent service routine
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pServiceRoutineParameter - the recurrent service routine parameter
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pTimeInterval - the time interval which controls the frequency of the recurrent
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service
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--*/
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{
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NTSTATUS Status;
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PAGED_CODE();
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pRecurrentServiceContext->State = RECURRENT_SERVICE_DORMANT;
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pRecurrentServiceContext->pServiceRoutine = pServiceRoutine;
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pRecurrentServiceContext->pServiceRoutineParameter = pServiceRoutineParameter;
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pRecurrentServiceContext->Interval.QuadPart = pTimeInterval->QuadPart;
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// Initialize the cancel completion event associated with the service
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KeInitializeEvent(
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&pRecurrentServiceContext->CancelCompletionEvent,
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NotificationEvent,
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FALSE);
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}
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VOID
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MRxSmbCancelRecurrentService(
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PRECURRENT_SERVICE_CONTEXT pRecurrentServiceContext)
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/*++
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Routine Description:
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This routine cancels a recurrent service
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Arguments:
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pRecurrentServiceContext - the recurrent service to be initialized
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Notes:
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When the cancel request is handled the recurrent service can be in one
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of two states -- either active or on the timer queue awaiting dispatch.
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The service state is changed and an attempt is made to cancel the service
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in the timer queue and if it fails this request is suspended till the
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active invocation of the service is completed
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--*/
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{
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NTSTATUS Status;
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LONG State;
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PAGED_CODE();
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State = InterlockedCompareExchange(
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&pRecurrentServiceContext->State,
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RECURRENT_SERVICE_CANCELLED,
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RECURRENT_SERVICE_ACTIVE);
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if (State == RECURRENT_SERVICE_ACTIVE) {
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// Cancel the echo processing timer request.
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Status = RxCancelTimerRequest(
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MRxSmbDeviceObject,
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MRxSmbRecurrentServiceDispatcher,
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pRecurrentServiceContext);
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if (Status != STATUS_SUCCESS) {
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// The request is currently active. Wait for it to be completed.
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KeWaitForSingleObject(
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&pRecurrentServiceContext->CancelCompletionEvent,
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Executive,
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KernelMode,
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FALSE,
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NULL);
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}
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}
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}
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VOID
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MRxSmbRecurrentServiceDispatcher(
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PVOID pContext)
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/*++
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Routine Description:
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This routine dispatches the recurrent service
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Arguments:
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pRecurrentServiceContext - the recurrent service to be initialized
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Notes:
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The dispatcher provides a centralized location for monitoring the state
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of the recurrent service prior to and after invocation. Based on the
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state a decision as to whether a subsequent request must be posted
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is made.
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--*/
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{
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NTSTATUS Status;
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PRECURRENT_SERVICE_CONTEXT pRecurrentServiceContext;
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LONG State;
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pRecurrentServiceContext = (PRECURRENT_SERVICE_CONTEXT)pContext;
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State = InterlockedCompareExchange(
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&pRecurrentServiceContext->State,
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RECURRENT_SERVICE_ACTIVE,
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RECURRENT_SERVICE_ACTIVE);
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// If the state of the service is active invoke the handler
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if (State == RECURRENT_SERVICE_ACTIVE) {
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Status = (pRecurrentServiceContext->pServiceRoutine)(
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pRecurrentServiceContext->pServiceRoutineParameter);
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State = InterlockedCompareExchange(
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&pRecurrentServiceContext->State,
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RECURRENT_SERVICE_ACTIVE,
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RECURRENT_SERVICE_ACTIVE);
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if (State == RECURRENT_SERVICE_ACTIVE) {
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// If the service is still active and further continuation
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// was desired by the handler post another timer request
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if (Status == STATUS_SUCCESS) {
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Status = RxPostOneShotTimerRequest(
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MRxSmbDeviceObject,
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&pRecurrentServiceContext->WorkItem,
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MRxSmbRecurrentServiceDispatcher,
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pRecurrentServiceContext,
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pRecurrentServiceContext->Interval);
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} else {
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do {
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State = InterlockedCompareExchange(
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&pRecurrentServiceContext->State,
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RECURRENT_SERVICE_DORMANT,
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State);
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} while (State != RECURRENT_SERVICE_DORMANT);
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}
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}
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}
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if (State == RECURRENT_SERVICE_CANCELLED) {
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// if the recurrent service was cancelled resume the cancel request
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KeSetEvent(
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&pRecurrentServiceContext->CancelCompletionEvent,
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0,
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FALSE );
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}
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}
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NTSTATUS
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MRxSmbActivateRecurrentService(
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PRECURRENT_SERVICE_CONTEXT pRecurrentServiceContext)
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/*++
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Routine Description:
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This routine activates a recurrent service
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Arguments:
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pRecurrentServiceContext - the recurrent service to be initialized
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Notes:
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--*/
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{
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NTSTATUS Status;
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LONG State;
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PAGED_CODE();
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State = InterlockedCompareExchange(
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&pRecurrentServiceContext->State,
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RECURRENT_SERVICE_ACTIVE,
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RECURRENT_SERVICE_DORMANT);
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if (State == RECURRENT_SERVICE_DORMANT) {
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Status = RxPostOneShotTimerRequest(
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MRxSmbDeviceObject,
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&pRecurrentServiceContext->WorkItem,
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MRxSmbRecurrentServiceDispatcher,
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pRecurrentServiceContext,
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pRecurrentServiceContext->Interval);
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} else if (State == RECURRENT_SERVICE_ACTIVE) {
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Status = STATUS_SUCCESS;
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} else if (State == RECURRENT_SERVICE_CANCELLED) {
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Status = STATUS_CANCELLED;
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}
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else if (State == RECURRENT_SERVICE_SHUTDOWN) {
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Status = STATUS_UNSUCCESSFUL;
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} else {
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ASSERT(!"Valid State for Recurrent Service");
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Status = STATUS_UNSUCCESSFUL;
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}
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return Status;
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}
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NTSTATUS
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MRxSmbInitializeRecurrentServices()
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/*++
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Routine Description:
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This routine initializes all the recurrent services associated with the SMB
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mini redirector
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Notes:
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--*/
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{
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NTSTATUS Status;
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LARGE_INTEGER RecurrentServiceInterval;
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BOOLEAN fEchoProbeServiceInitialized = FALSE;
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BOOLEAN fScavengerServiceInitialized = FALSE;
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PAGED_CODE();
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try {
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RecurrentServiceInterval.QuadPart = 30 * 1000 * 10000; // 30 seconds in 100 ns intervals
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MRxSmbInitializeRecurrentService(
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&MRxSmbEchoProbeServiceContext.RecurrentServiceContext,
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SmbCeProbeServers,
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&MRxSmbEchoProbeServiceContext,
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&RecurrentServiceInterval);
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Status = MRxSmbInitializeEchoProbeService(
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&MRxSmbEchoProbeServiceContext);
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if (Status == STATUS_SUCCESS) {
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fEchoProbeServiceInitialized = TRUE;
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Status = MRxSmbActivateRecurrentService(
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&MRxSmbEchoProbeServiceContext.RecurrentServiceContext);
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}
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if (Status != STATUS_SUCCESS) {
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try_return(Status);
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}
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MRxSmbInitializeRecurrentService(
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&MRxSmbScavengerServiceContext.RecurrentServiceContext,
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SmbCeScavenger,
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&MRxSmbScavengerServiceContext,
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&RecurrentServiceInterval);
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Status = MRxSmbInitializeScavengerService(
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&MRxSmbScavengerServiceContext);
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if (Status == STATUS_SUCCESS) {
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fScavengerServiceInitialized = TRUE;
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}
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try_exit: NOTHING;
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} finally {
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if (Status != STATUS_SUCCESS) {
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if (fEchoProbeServiceInitialized) {
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SmbCeLog(("Tearing down Echo Probe Service\n"));
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SmbLogError(Status,
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LOG,
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MRxSmbInitializeRecurrentServices,
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LOGULONG(Status));
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MRxSmbTearDownEchoProbeService(
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&MRxSmbEchoProbeServiceContext);
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}
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}
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};
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return Status;
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}
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VOID
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MRxSmbTearDownRecurrentServices()
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/*++
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Routine Description:
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This routine tears down the recurrent services associated with the
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SMB mini redirector
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Notes:
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--*/
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{
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PAGED_CODE();
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MRxSmbCancelRecurrentService(
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&MRxSmbEchoProbeServiceContext.RecurrentServiceContext);
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MRxSmbEchoProbeServiceContext.RecurrentServiceContext.State = RECURRENT_SERVICE_SHUTDOWN;
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MRxSmbTearDownEchoProbeService(
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&MRxSmbEchoProbeServiceContext);
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MRxSmbCancelRecurrentService(
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&MRxSmbScavengerServiceContext.RecurrentServiceContext);
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MRxSmbScavengerServiceContext.RecurrentServiceContext.State = RECURRENT_SERVICE_SHUTDOWN;
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MRxSmbTearDownScavengerService(
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&MRxSmbScavengerServiceContext);
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}
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NTSTATUS
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MRxSmbInitializeScavengerService(
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PMRXSMB_SCAVENGER_SERVICE_CONTEXT pScavengerServiceContext)
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/*++
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Routine Description:
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This routine initializes the scavenger recurrent service
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Arguments:
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pScavengerServiceContext - the recurrent service to be initialized
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Notes:
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--*/
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{
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PAGED_CODE();
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InitializeListHead(
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&pScavengerServiceContext->VNetRootContexts.ListHead);
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return STATUS_SUCCESS;
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}
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VOID
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MRxSmbTearDownScavengerService(
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PMRXSMB_SCAVENGER_SERVICE_CONTEXT pScavengerServiceContext)
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/*++
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Routine Description:
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This routine tears down the scavenger recurrent service
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Arguments:
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pScavengerServiceContext - the recurrent service to be initialized
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Notes:
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--*/
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{
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PAGED_CODE();
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SmbCeScavenger(pScavengerServiceContext);
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}
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