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Diffstat (limited to 'filesys/miniFilter/nullFilter/nullFilter.c')
| -rw-r--r-- | filesys/miniFilter/nullFilter/nullFilter.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/filesys/miniFilter/nullFilter/nullFilter.c b/filesys/miniFilter/nullFilter/nullFilter.c new file mode 100644 index 00000000..9944db13 --- /dev/null +++ b/filesys/miniFilter/nullFilter/nullFilter.c @@ -0,0 +1,240 @@ +/*++ + +Copyright (c) 1999 - 2002 Microsoft Corporation + +Module Name: + + nullFilter.c + +Abstract: + + This is the main module of the nullFilter mini filter driver. + It is a simple minifilter that registers itself with the main filter + for no callback operations. + +Environment: + + Kernel mode + +--*/ + +#include <fltKernel.h> +#include <dontuse.h> +#include <suppress.h> + +#pragma prefast(disable:__WARNING_ENCODE_MEMBER_FUNCTION_POINTER, "Not valid for kernel mode drivers") + +//--------------------------------------------------------------------------- +// Global variables +//--------------------------------------------------------------------------- + +#define NULL_FILTER_FILTER_NAME L"NullFilter" + +typedef struct _NULL_FILTER_DATA { + + // + // The filter handle that results from a call to + // FltRegisterFilter. + // + + PFLT_FILTER FilterHandle; + +} NULL_FILTER_DATA, *PNULL_FILTER_DATA; + + +/************************************************************************* + Prototypes for the startup and unload routines used for + this Filter. + + Implementation in nullFilter.c +*************************************************************************/ + +DRIVER_INITIALIZE DriverEntry; +NTSTATUS +DriverEntry ( + _In_ PDRIVER_OBJECT DriverObject, + _In_ PUNICODE_STRING RegistryPath + ); + +NTSTATUS +NullUnload ( + _In_ FLT_FILTER_UNLOAD_FLAGS Flags + ); + +NTSTATUS +NullQueryTeardown ( + _In_ PCFLT_RELATED_OBJECTS FltObjects, + _In_ FLT_INSTANCE_QUERY_TEARDOWN_FLAGS Flags + ); + +// +// Structure that contains all the global data structures +// used throughout NullFilter. +// + +NULL_FILTER_DATA NullFilterData; + +// +// Assign text sections for each routine. +// + +#ifdef ALLOC_PRAGMA +#pragma alloc_text(INIT, DriverEntry) +#pragma alloc_text(PAGE, NullUnload) +#pragma alloc_text(PAGE, NullQueryTeardown) +#endif + + +// +// This defines what we want to filter with FltMgr +// + +CONST FLT_REGISTRATION FilterRegistration = { + + sizeof( FLT_REGISTRATION ), // Size + FLT_REGISTRATION_VERSION, // Version + 0, // Flags + + NULL, // Context + NULL, // Operation callbacks + + NullUnload, // FilterUnload + + NULL, // InstanceSetup + NullQueryTeardown, // InstanceQueryTeardown + NULL, // InstanceTeardownStart + NULL, // InstanceTeardownComplete + + NULL, // GenerateFileName + NULL, // GenerateDestinationFileName + NULL // NormalizeNameComponent + +}; + + +/************************************************************************* + Filter initialization and unload routines. +*************************************************************************/ + +NTSTATUS +DriverEntry ( + _In_ PDRIVER_OBJECT DriverObject, + _In_ PUNICODE_STRING RegistryPath + ) +/*++ + +Routine Description: + + This is the initialization routine for this miniFilter driver. This + registers the miniFilter with FltMgr and initializes all + its global data structures. + +Arguments: + + DriverObject - Pointer to driver object created by the system to + represent this driver. + RegistryPath - Unicode string identifying where the parameters for this + driver are located in the registry. + +Return Value: + + Returns STATUS_SUCCESS. + +--*/ +{ + NTSTATUS status; + + UNREFERENCED_PARAMETER( RegistryPath ); + + // + // Register with FltMgr + // + + status = FltRegisterFilter( DriverObject, + &FilterRegistration, + &NullFilterData.FilterHandle ); + + FLT_ASSERT( NT_SUCCESS( status ) ); + + if (NT_SUCCESS( status )) { + + // + // Start filtering i/o + // + + status = FltStartFiltering( NullFilterData.FilterHandle ); + + if (!NT_SUCCESS( status )) { + FltUnregisterFilter( NullFilterData.FilterHandle ); + } + } + return status; +} + +NTSTATUS +NullUnload ( + _In_ FLT_FILTER_UNLOAD_FLAGS Flags + ) +/*++ + +Routine Description: + + This is the unload routine for this miniFilter driver. This is called + when the minifilter is about to be unloaded. We can fail this unload + request if this is not a mandatory unloaded indicated by the Flags + parameter. + +Arguments: + + Flags - Indicating if this is a mandatory unload. + +Return Value: + + Returns the final status of this operation. + +--*/ +{ + UNREFERENCED_PARAMETER( Flags ); + + PAGED_CODE(); + + FltUnregisterFilter( NullFilterData.FilterHandle ); + + return STATUS_SUCCESS; +} + +NTSTATUS +NullQueryTeardown ( + _In_ PCFLT_RELATED_OBJECTS FltObjects, + _In_ FLT_INSTANCE_QUERY_TEARDOWN_FLAGS Flags + ) +/*++ + +Routine Description: + + This is the instance detach routine for this miniFilter driver. + This is called when an instance is being manually deleted by a + call to FltDetachVolume or FilterDetach thereby giving us a + chance to fail that detach request. + +Arguments: + + FltObjects - Pointer to the FLT_RELATED_OBJECTS data structure containing + opaque handles to this filter, instance and its associated volume. + + Flags - Indicating where this detach request came from. + +Return Value: + + Returns the status of this operation. + +--*/ +{ + UNREFERENCED_PARAMETER( FltObjects ); + UNREFERENCED_PARAMETER( Flags ); + + PAGED_CODE(); + + return STATUS_SUCCESS; +} + |