2016-09-06 16:47:43 +00:00
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/*
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* PROJECT: Filesystem Filter Manager
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* LICENSE: GPL - See COPYING in the top level directory
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* FILE: drivers/filters/fltmgr/Filter.c
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* PURPOSE: Handles registration of mini filters
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* PROGRAMMERS: Ged Murphy (gedmurphy@reactos.org)
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*/
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/* INCLUDES ******************************************************************/
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#include "fltmgr.h"
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#include "fltmgrint.h"
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2017-11-21 16:36:29 +00:00
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#include "Registry.h"
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2016-09-06 16:47:43 +00:00
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#define NDEBUG
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#include <debug.h>
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/* DATA *********************************************************************/
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#define SERVICES_KEY L"\\Registry\\Machine\\System\\CurrentControlSet\\Services\\"
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#define MAX_KEY_LENGTH 0x200
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NTSTATUS
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FltpStartingToDrainObject(
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_Inout_ PFLT_OBJECT Object
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);
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2017-11-21 16:36:29 +00:00
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VOID
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FltpMiniFilterDriverUnload(
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);
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static
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NTSTATUS
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GetFilterAltitude(
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_In_ PFLT_FILTER Filter,
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_Inout_ PUNICODE_STRING AltitudeString
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);
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2016-09-06 16:47:43 +00:00
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/* EXPORTED FUNCTIONS ******************************************************/
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NTSTATUS
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NTAPI
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FltLoadFilter(_In_ PCUNICODE_STRING FilterName)
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{
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UNICODE_STRING DriverServiceName;
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UNICODE_STRING ServicesKey;
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CHAR Buffer[MAX_KEY_LENGTH];
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/* Setup the base services key */
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RtlInitUnicodeString(&ServicesKey, SERVICES_KEY);
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/* Initialize the string data */
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DriverServiceName.Length = 0;
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DriverServiceName.Buffer = (PWCH)Buffer;
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DriverServiceName.MaximumLength = MAX_KEY_LENGTH;
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/* Create the full service key for this filter */
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RtlCopyUnicodeString(&DriverServiceName, &ServicesKey);
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RtlAppendUnicodeStringToString(&DriverServiceName, FilterName);
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/* Ask the kernel to load it for us */
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return ZwLoadDriver(&DriverServiceName);
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}
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NTSTATUS
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NTAPI
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FltUnloadFilter(_In_ PCUNICODE_STRING FilterName)
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{
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2017-11-21 16:36:29 +00:00
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//
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//FIXME: This is a temp hack, it needs properly implementing
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//
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UNICODE_STRING DriverServiceName;
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UNICODE_STRING ServicesKey;
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CHAR Buffer[MAX_KEY_LENGTH];
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/* Setup the base services key */
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RtlInitUnicodeString(&ServicesKey, SERVICES_KEY);
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/* Initialize the string data */
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DriverServiceName.Length = 0;
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DriverServiceName.Buffer = (PWCH)Buffer;
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DriverServiceName.MaximumLength = MAX_KEY_LENGTH;
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/* Create the full service key for this filter */
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RtlCopyUnicodeString(&DriverServiceName, &ServicesKey);
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RtlAppendUnicodeStringToString(&DriverServiceName, FilterName);
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return ZwUnloadDriver(&DriverServiceName);
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2016-09-06 16:47:43 +00:00
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}
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NTSTATUS
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NTAPI
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FltRegisterFilter(_In_ PDRIVER_OBJECT DriverObject,
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_In_ const FLT_REGISTRATION *Registration,
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_Out_ PFLT_FILTER *RetFilter)
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{
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PFLT_OPERATION_REGISTRATION Callbacks;
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PFLT_FILTER Filter;
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ULONG CallbackBufferSize;
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ULONG FilterBufferSize;
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ULONG Count = 0;
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PCHAR Ptr;
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NTSTATUS Status;
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2017-11-21 16:36:29 +00:00
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*RetFilter = NULL;
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2016-09-06 16:47:43 +00:00
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/* Make sure we're targeting the correct major revision */
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if ((Registration->Version & 0xFF00) != FLT_MAJOR_VERSION)
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{
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return STATUS_INVALID_PARAMETER;
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}
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/* Make sure our namespace callbacks are valid */
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if ((!Registration->GenerateFileNameCallback && Registration->NormalizeNameComponentCallback) ||
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(!Registration->NormalizeNameComponentCallback && Registration->NormalizeContextCleanupCallback))
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{
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return STATUS_INVALID_PARAMETER;
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}
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/* Count the number of operations that were requested */
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Callbacks = (PFLT_OPERATION_REGISTRATION)Registration->OperationRegistration;
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while (Callbacks)
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{
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Count++;
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/* Bail when we find the last one */
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if (Callbacks->MajorFunction == IRP_MJ_OPERATION_END)
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break;
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/* Move to the next item */
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Callbacks++;
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}
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/* Calculate the buffer sizes */
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CallbackBufferSize = Count * sizeof(FLT_OPERATION_REGISTRATION);
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FilterBufferSize = sizeof(FLT_FILTER) +
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CallbackBufferSize +
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DriverObject->DriverExtension->ServiceKeyName.Length;
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/* Allocate a buffer to hold our filter data */
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Filter = ExAllocatePoolWithTag(NonPagedPool,
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FilterBufferSize,
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FM_TAG_FILTER);
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if (Filter == NULL) return STATUS_INSUFFICIENT_RESOURCES;
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RtlZeroMemory(Filter, FilterBufferSize);
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/* Find the end of the fixed struct */
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Ptr = (PCHAR)(Filter + 1);
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/* Store a copy of the driver object of this filter */
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Filter->DriverObject = DriverObject;
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/* Initialize the base object data */
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Filter->Base.Flags = FLT_OBFL_TYPE_FILTER;
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Filter->Base.PointerCount = 1;
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FltpExInitializeRundownProtection(&Filter->Base.RundownRef);
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FltObjectReference(&Filter->Base);
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/* Set the callback addresses */
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Filter->FilterUnload = Registration->FilterUnloadCallback;
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Filter->InstanceSetup = Registration->InstanceSetupCallback;
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Filter->InstanceQueryTeardown = Registration->InstanceQueryTeardownCallback;
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Filter->InstanceTeardownStart = Registration->InstanceTeardownStartCallback;
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Filter->InstanceTeardownComplete = Registration->InstanceTeardownCompleteCallback;
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Filter->GenerateFileName = Registration->GenerateFileNameCallback;
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Filter->NormalizeNameComponent = Registration->NormalizeNameComponentCallback;
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Filter->NormalizeContextCleanup = Registration->NormalizeContextCleanupCallback;
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/* Initialize the instance list */
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ExInitializeResourceLite(&Filter->InstanceList.rLock);
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InitializeListHead(&Filter->InstanceList.rList);
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Filter->InstanceList.rCount = 0;
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ExInitializeFastMutex(&Filter->ActiveOpens.mLock);
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InitializeListHead(&Filter->ActiveOpens.mList);
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Filter->ActiveOpens.mCount = 0;
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2017-11-21 16:36:29 +00:00
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ExInitializeFastMutex(&Filter->ConnectionList.mLock);
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InitializeListHead(&Filter->ConnectionList.mList);
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Filter->ConnectionList.mCount = 0;
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2016-09-06 16:47:43 +00:00
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/* Initialize the usermode port list */
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ExInitializeFastMutex(&Filter->PortList.mLock);
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InitializeListHead(&Filter->PortList.mList);
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Filter->PortList.mCount = 0;
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/* We got this far, assume success from here */
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Status = STATUS_SUCCESS;
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/* Check if the caller requested any context data */
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if (Registration->ContextRegistration)
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{
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/* Register the contexts for this filter */
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Status = FltpRegisterContexts(Filter, Registration->ContextRegistration);
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if (NT_SUCCESS(Status))
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{
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goto Quit;
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}
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}
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/* Check if the caller is registering any callbacks */
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if (Registration->OperationRegistration)
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{
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/* The callback data comes after the fixed struct */
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Filter->Operations = (PFLT_OPERATION_REGISTRATION)Ptr;
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Ptr += (Count * sizeof(FLT_OPERATION_REGISTRATION));
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/* Tag the operation data onto the end of the filter data */
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RtlCopyMemory(Filter->Operations, Registration->OperationRegistration, CallbackBufferSize);
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/* walk through the requested callbacks */
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for (Callbacks = Filter->Operations;
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Callbacks->MajorFunction != IRP_MJ_OPERATION_END;
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Callbacks++)
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{
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// http://fsfilters.blogspot.co.uk/2011/03/how-file-system-filters-attach-to_17.html
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/* Check if this is an attach to a volume */
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if (Callbacks->MajorFunction == IRP_MJ_VOLUME_MOUNT)
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{
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Filter->PreVolumeMount = Callbacks->PreOperation;
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Filter->PostVolumeMount = Callbacks->PostOperation;
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}
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else if (Callbacks->MajorFunction == IRP_MJ_SHUTDOWN)
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{
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Callbacks->PostOperation = NULL;
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}
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}
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}
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/* Add the filter name buffer onto the end of the data and fill in the string */
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Filter->Name.Length = 0;
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Filter->Name.MaximumLength = DriverObject->DriverExtension->ServiceKeyName.Length;
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Filter->Name.Buffer = (PWCH)Ptr;
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RtlCopyUnicodeString(&Filter->Name, &DriverObject->DriverExtension->ServiceKeyName);
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2017-11-21 16:36:29 +00:00
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Status = GetFilterAltitude(Filter, &Filter->DefaultAltitude);
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if (!NT_SUCCESS(Status))
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{
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goto Quit;
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}
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2016-09-06 16:47:43 +00:00
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//
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// - Slot the filter into the correct altitude location
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// - More stuff??
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//
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2017-11-21 16:36:29 +00:00
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/* Store any existing driver unload routine before we make any changes */
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Filter->OldDriverUnload = (PFLT_FILTER_UNLOAD_CALLBACK)DriverObject->DriverUnload;
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/* Check we opted not to have an unload routine, or if we want to stop the driver from being unloaded */
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if (!FlagOn(Filter->Flags, FLTFL_REGISTRATION_DO_NOT_SUPPORT_SERVICE_STOP))
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{
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DriverObject->DriverUnload = (PDRIVER_UNLOAD)FltpMiniFilterDriverUnload;
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}
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else
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{
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DriverObject->DriverUnload = (PDRIVER_UNLOAD)NULL;
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}
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2016-09-06 16:47:43 +00:00
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Quit:
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2017-11-21 16:36:29 +00:00
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if (NT_SUCCESS(Status))
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{
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DPRINT1("Loaded FS mini-filter %wZ\n", &DriverObject->DriverExtension->ServiceKeyName);
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*RetFilter = Filter;
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}
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else
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2016-09-06 16:47:43 +00:00
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{
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2017-11-21 16:36:29 +00:00
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DPRINT1("Failed to load FS mini-filter %wZ : 0x%X\n", &DriverObject->DriverExtension->ServiceKeyName, Status);
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2016-09-06 16:47:43 +00:00
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// Add cleanup for context resources
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ExDeleteResourceLite(&Filter->InstanceList.rLock);
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ExFreePoolWithTag(Filter, FM_TAG_FILTER);
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}
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return Status;
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}
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VOID
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FLTAPI
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FltUnregisterFilter(_In_ PFLT_FILTER Filter)
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{
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PFLT_INSTANCE Instance;
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PLIST_ENTRY CurrentEntry;
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NTSTATUS Status;
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/* Set the draining flag */
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Status = FltpStartingToDrainObject(&Filter->Base);
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if (!NT_SUCCESS(Status))
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{
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/* Someone already unregistered us, just remove our ref and bail */
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FltObjectDereference(&Filter->Base);
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return;
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}
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/* Lock the instance list */
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KeEnterCriticalRegion();
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ExAcquireResourceSharedLite(&Filter->InstanceList.rLock, TRUE);
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/* Set the first entry in the list */
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CurrentEntry = Filter->InstanceList.rList.Flink;
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/* Free all instances referenced by the filter */
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while (CurrentEntry != &Filter->InstanceList.rList)
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{
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/* Get the record pointer */
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Instance = CONTAINING_RECORD(CurrentEntry, FLT_INSTANCE, FilterLink);
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// FIXME: implement
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(void)Instance;
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/* Reset the pointer and move to next entry */
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Instance = NULL;
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CurrentEntry = CurrentEntry->Flink;
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}
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/* We're done with instances now */
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ExReleaseResourceLite(&Filter->InstanceList.rLock);
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KeLeaveCriticalRegion();
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/* Remove the reference from the base object */
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FltObjectDereference(&Filter->Base);
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/* Wait until we're sure nothing is using the filter */
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FltpObjectRundownWait(&Filter->Base.RundownRef);
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/* Delete the instance list lock */
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ExDeleteResourceLite(&Filter->InstanceList.rLock);
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/* We're finished cleaning up now */
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FltpExRundownCompleted(&Filter->Base.RundownRef);
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/* Hand the memory back */
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ExFreePoolWithTag(Filter, FM_TAG_FILTER);
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}
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NTSTATUS
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NTAPI
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FltStartFiltering(_In_ PFLT_FILTER Filter)
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{
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NTSTATUS Status;
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/* Grab a ref to the filter */
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Status = FltObjectReference(&Filter->Base);
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if (NT_SUCCESS(Status))
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{
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/* Make sure we aren't already starting up */
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if (!(Filter->Flags & FLTFL_FILTERING_INITIATED))
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{
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// Startup
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}
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else
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{
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Status = STATUS_INVALID_PARAMETER;
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}
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FltObjectDereference(&Filter->Base);
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}
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return Status;
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}
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/* INTERNAL FUNCTIONS ******************************************************/
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NTSTATUS
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FltpStartingToDrainObject(_Inout_ PFLT_OBJECT Object)
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{
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/*
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* Set the draining flag for the filter. This let's us force
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* a post op callback for minifilters currently awaiting one.
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*/
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if (InterlockedOr((PLONG)&Object->Flags, FLT_OBFL_DRAINING) & 1)
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{
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/* We've been called once, we're already being deleted */
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return STATUS_FLT_DELETING_OBJECT;
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}
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|
|
|
|
|
|
return STATUS_SUCCESS;
|
|
|
|
}
|
2017-11-21 16:36:29 +00:00
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|
|
|
|
|
|
VOID
|
|
|
|
FltpMiniFilterDriverUnload()
|
|
|
|
{
|
|
|
|
__debugbreak();
|
|
|
|
}
|
|
|
|
|
|
|
|
/* PRIVATE FUNCTIONS ******************************************************/
|
|
|
|
|
|
|
|
static
|
|
|
|
NTSTATUS
|
|
|
|
GetFilterAltitude(
|
|
|
|
_In_ PFLT_FILTER Filter,
|
|
|
|
_Inout_ PUNICODE_STRING AltitudeString)
|
|
|
|
{
|
|
|
|
UNICODE_STRING InstancesKey = RTL_CONSTANT_STRING(L"Instances");
|
|
|
|
UNICODE_STRING DefaultInstance = RTL_CONSTANT_STRING(L"DefaultInstance");
|
|
|
|
UNICODE_STRING Altitude = RTL_CONSTANT_STRING(L"Altitude");
|
|
|
|
OBJECT_ATTRIBUTES ObjectAttributes;
|
|
|
|
UNICODE_STRING FilterInstancePath;
|
|
|
|
ULONG BytesRequired;
|
|
|
|
HANDLE InstHandle = NULL;
|
|
|
|
HANDLE RootHandle;
|
|
|
|
PWCH InstBuffer = NULL;
|
|
|
|
PWCH AltBuffer = NULL;
|
|
|
|
NTSTATUS Status;
|
|
|
|
|
|
|
|
/* Get a handle to the instances key in the filter's services key */
|
|
|
|
Status = FltpOpenFilterServicesKey(Filter,
|
|
|
|
KEY_QUERY_VALUE,
|
|
|
|
&InstancesKey,
|
|
|
|
&RootHandle);
|
|
|
|
if (!NT_SUCCESS(Status))
|
|
|
|
{
|
|
|
|
return Status;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Read the size 'default instances' string value */
|
|
|
|
Status = FltpReadRegistryValue(RootHandle,
|
|
|
|
&DefaultInstance,
|
|
|
|
REG_SZ,
|
|
|
|
NULL,
|
|
|
|
0,
|
|
|
|
&BytesRequired);
|
|
|
|
|
|
|
|
/* We should get a buffer too small error */
|
|
|
|
if (Status == STATUS_BUFFER_TOO_SMALL)
|
|
|
|
{
|
|
|
|
/* Allocate the buffer we need to hold the string */
|
|
|
|
InstBuffer = ExAllocatePoolWithTag(PagedPool, BytesRequired, FM_TAG_UNICODE_STRING);
|
|
|
|
if (InstBuffer == NULL)
|
|
|
|
{
|
|
|
|
Status = STATUS_INSUFFICIENT_RESOURCES;
|
|
|
|
goto Quit;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Now read the string value */
|
|
|
|
Status = FltpReadRegistryValue(RootHandle,
|
|
|
|
&DefaultInstance,
|
|
|
|
REG_SZ,
|
|
|
|
InstBuffer,
|
|
|
|
BytesRequired,
|
|
|
|
&BytesRequired);
|
|
|
|
}
|
|
|
|
|
|
|
|
if (!NT_SUCCESS(Status))
|
|
|
|
{
|
|
|
|
goto Quit;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Convert the string to a unicode_string */
|
|
|
|
RtlInitUnicodeString(&FilterInstancePath, InstBuffer);
|
|
|
|
|
|
|
|
/* Setup the attributes using the root key handle */
|
|
|
|
InitializeObjectAttributes(&ObjectAttributes,
|
|
|
|
&FilterInstancePath,
|
|
|
|
OBJ_KERNEL_HANDLE | OBJ_CASE_INSENSITIVE,
|
|
|
|
RootHandle,
|
|
|
|
NULL);
|
|
|
|
|
|
|
|
/* Now open the key name which was stored in the default instance */
|
|
|
|
Status = ZwOpenKey(&InstHandle, KEY_QUERY_VALUE, &ObjectAttributes);
|
|
|
|
if (NT_SUCCESS(Status))
|
|
|
|
{
|
|
|
|
/* Get the size of the buffer that holds the altitude */
|
|
|
|
Status = FltpReadRegistryValue(InstHandle,
|
|
|
|
&Altitude,
|
|
|
|
REG_SZ,
|
|
|
|
NULL,
|
|
|
|
0,
|
|
|
|
&BytesRequired);
|
|
|
|
if (Status == STATUS_BUFFER_TOO_SMALL)
|
|
|
|
{
|
|
|
|
/* Allocate the required buffer */
|
|
|
|
AltBuffer = ExAllocatePoolWithTag(PagedPool, BytesRequired, FM_TAG_UNICODE_STRING);
|
|
|
|
if (AltBuffer == NULL)
|
|
|
|
{
|
|
|
|
Status = STATUS_INSUFFICIENT_RESOURCES;
|
|
|
|
goto Quit;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* And now finally read in the actual altitude string */
|
|
|
|
Status = FltpReadRegistryValue(InstHandle,
|
|
|
|
&Altitude,
|
|
|
|
REG_SZ,
|
|
|
|
AltBuffer,
|
|
|
|
BytesRequired,
|
|
|
|
&BytesRequired);
|
|
|
|
if (NT_SUCCESS(Status))
|
|
|
|
{
|
|
|
|
/* We made it, setup the return buffer */
|
|
|
|
AltitudeString->Length = BytesRequired;
|
|
|
|
AltitudeString->MaximumLength = BytesRequired;
|
|
|
|
AltitudeString->Buffer = AltBuffer;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
Quit:
|
|
|
|
if (!NT_SUCCESS(Status))
|
|
|
|
{
|
|
|
|
if (AltBuffer)
|
|
|
|
{
|
|
|
|
ExFreePoolWithTag(AltBuffer, FM_TAG_UNICODE_STRING);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
if (InstBuffer)
|
|
|
|
{
|
|
|
|
ExFreePoolWithTag(InstBuffer, FM_TAG_UNICODE_STRING);
|
|
|
|
}
|
|
|
|
|
|
|
|
if (InstHandle)
|
|
|
|
{
|
|
|
|
ZwClose(InstHandle);
|
|
|
|
}
|
|
|
|
ZwClose(RootHandle);
|
|
|
|
|
|
|
|
return Status;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
NTSTATUS
|
|
|
|
FltpReadRegistryValue(
|
|
|
|
_In_ HANDLE KeyHandle,
|
|
|
|
_In_ PUNICODE_STRING ValueName,
|
|
|
|
_In_opt_ ULONG Type,
|
|
|
|
_Out_writes_bytes_(BufferSize) PVOID Buffer,
|
|
|
|
_In_ ULONG BufferSize,
|
|
|
|
_Out_opt_ PULONG BytesRequired
|
|
|
|
);
|