[MiniFilter]驱动隐藏文件夹的实现（支持Win7）

刚完成一个利用驱动隐藏文件夹的程序，隐藏文件的类似，现在贴出来共享给大家。

代码相对比较简单，我是在别人代码的基础上改的。

因为现在在网上找到的代码都是不支持XP以上版本的，所以我在别人代码的基础上添加了XP以上版本的支持。

现在该代码同时支持XP以下及XP以上版本（本人仅测试XP和Win7）。

利用驱动实现文件的隐藏主要是在IRP_MJ_DIRECTORY_CONTROL的后操作回调函数中处理其输入参数FLT_CALLBACK_DATA结构中的缓冲区数据。

该缓冲地址的获取是重点，Data->Iopb->Parameters.DirectoryControl.QueryDirectory.DirectoryBuffer（或MdlAddress）

网上现有代码不支持XP以上版本的原因是Vista或Win7返回的FileInformationClass结构不再是FileBothDirectoryInformation，而是FileIdBothDirectoryInformation

【注】虽然利用驱动隐藏文件无法利用“显示隐藏文件”查看，但文件实际仍存在，通过路径仍然可以访问。

实现代码如下：

//[Modify By js2854 2010-10-29 Support Windows 7]

#include <fltKernel.h>
#include <dontuse.h>
#include <suppress.h>

#pragma prefast(disable:__WARNING_ENCODE_MEMBER_FUNCTION_POINTER, "Not valid for kernel mode drivers")

//
//  This is how FltMgr was released (from oldest to newest) [仅编译时决定,而非运行时]
//  This defines items that only exist in longhorn or later [判断系统版本是否VISTA以上版本]
//

#define FLT_MGR_LONGHORN (NTDDI_VERSION >= NTDDI_VISTA)

PFLT_FILTER filterHandle;
PWCHAR prefixName = L"HideDir";//要隐藏的文件夹名字的前缀 

/*************************************************************************
    Prototypes
*************************************************************************/

NTSTATUS DriverEntry ( __in PDRIVER_OBJECT DriverObject, __in PUNICODE_STRING RegistryPath );
NTSTATUS PtUnload ( __in FLT_FILTER_UNLOAD_FLAGS Flags );
                                                             
FLT_POSTOP_CALLBACK_STATUS 
HideFilePostDirCtrl ( 
__inout PFLT_CALLBACK_DATA Data,
__in PCFLT_RELATED_OBJECTS FltObjects,
__in_opt PVOID CompletionContext,
__in FLT_POST_OPERATION_FLAGS Flags );
    
#ifdef ALLOC_PRAGMA
#pragma alloc_text(INIT, DriverEntry)
#pragma alloc_text(PAGE, PtUnload)
#endif

CONST FLT_OPERATION_REGISTRATION Callbacks[] =
{
    { IRP_MJ_DIRECTORY_CONTROL,
      0,
      NULL,
      HideFilePostDirCtrl },

    { IRP_MJ_OPERATION_END }
};

CONST FLT_REGISTRATION FilterRegistration =
{
    sizeof( FLT_REGISTRATION ),         //  Size
    FLT_REGISTRATION_VERSION,           //  Version
    0,                                  //  Flags
    NULL,                               //  Context
    Callbacks,                          //  Operation callbacks
    PtUnload,                           //  MiniFilterUnload
    NULL,                               //  InstanceSetup
    NULL,                               //  InstanceQueryTeardown
    NULL,                               //  InstanceTeardownStart
    NULL,                               //  InstanceTeardownComplete
    NULL,                               //  GenerateFileName
    NULL,                               //  GenerateDestinationFileName
    NULL                                //  NormalizeNameComponent
};

NTSTATUS DriverEntry ( __in PDRIVER_OBJECT DriverObject, __in PUNICODE_STRING RegistryPath )
{
    NTSTATUS status;

    UNREFERENCED_PARAMETER( RegistryPath );

    status = FltRegisterFilter( DriverObject, &FilterRegistration, &filterHandle );

    if (NT_SUCCESS( status ))
    {
        status = FltStartFiltering( filterHandle );

        if (!NT_SUCCESS( status ))
        {
            FltUnregisterFilter( filterHandle );
        }
    }

    return status;
}

NTSTATUS PtUnload ( __in FLT_FILTER_UNLOAD_FLAGS Flags )
{
    UNREFERENCED_PARAMETER( Flags );
    PAGED_CODE();

    FltUnregisterFilter( filterHandle );

    return STATUS_SUCCESS;
}

FLT_POSTOP_CALLBACK_STATUS 
HideFilePostDirCtrl ( 
__inout PFLT_CALLBACK_DATA Data,
__in PCFLT_RELATED_OBJECTS FltObjects,
__in_opt PVOID CompletionContext,
__in FLT_POST_OPERATION_FLAGS Flags )
{
    ULONG nextOffset = 0;
    int modified = 0;
    int removedAllEntries = 1;
    PVOID SafeBuffer;
    
#if FLT_MGR_LONGHORN
    PFILE_ID_BOTH_DIR_INFORMATION currentFileInfo = 0;
    PFILE_ID_BOTH_DIR_INFORMATION nextFileInfo = 0;
    PFILE_ID_BOTH_DIR_INFORMATION previousFileInfo = 0;
#else
    PFILE_BOTH_DIR_INFORMATION currentFileInfo = 0;
    PFILE_BOTH_DIR_INFORMATION nextFileInfo = 0;
    PFILE_BOTH_DIR_INFORMATION previousFileInfo = 0;
#endif   
    
    UNICODE_STRING fileName;
    
    UNREFERENCED_PARAMETER( FltObjects );
    UNREFERENCED_PARAMETER( CompletionContext );

    if( FlagOn( Flags, FLTFL_POST_OPERATION_DRAINING ) )
    {
        return FLT_POSTOP_FINISHED_PROCESSING;
    }
    
    //vista或win7返回的FileInformationClass结构不再是FileBothDirectoryInformation.
    //而是FileidBothDirectoryInformation
    if( Data->Iopb->MinorFunction == IRP_MN_QUERY_DIRECTORY && 
        (Data->Iopb->Parameters.DirectoryControl.QueryDirectory.FileInformationClass == FileBothDirectoryInformation ||
        Data->Iopb->Parameters.DirectoryControl.QueryDirectory.FileInformationClass ==FileIdBothDirectoryInformation ) &&
        Data->Iopb->Parameters.DirectoryControl.QueryDirectory.Length > 0 &&
        NT_SUCCESS(Data->IoStatus.Status))
    {
        if (Data->Iopb->Parameters.DirectoryControl.QueryDirectory.MdlAddress != NULL)
        {
            SafeBuffer=MmGetSystemAddressForMdlSafe( 
                         Data->Iopb->Parameters.DirectoryControl.QueryDirectory.MdlAddress,
                         NormalPagePriority );            
        }
        else
         {
             SafeBuffer=Data->Iopb->Parameters.DirectoryControl.QueryDirectory.DirectoryBuffer;             
         }     
        
        if(SafeBuffer==NULL)
        {
            return FLT_POSTOP_FINISHED_PROCESSING;
        }
        
        #if FLT_MGR_LONGHORN
               currentFileInfo = (PFILE_ID_BOTH_DIR_INFORMATION)SafeBuffer;
        #else
               currentFileInfo = (PFILE_BOTH_DIR_INFORMATION)SafeBuffer;
        #endif
       
        previousFileInfo = currentFileInfo;
            
        do
        {
            //Byte offset of the next FILE_BOTH_DIR_INFORMATION entry
            nextOffset = currentFileInfo->NextEntryOffset;

            #if FLT_MGR_LONGHORN
                nextFileInfo = (PFILE_ID_BOTH_DIR_INFORMATION)((PCHAR)(currentFileInfo) + nextOffset);
            #else
                nextFileInfo = (PFILE_BOTH_DIR_INFORMATION)((PCHAR)(currentFileInfo) + nextOffset);
            #endif
            //若满足条件，隐藏之 
            if(_wcsnicmp(currentFileInfo->FileName,prefixName,wcslen(prefixName))==0)
            {                
                if( nextOffset == 0 )
                {
                    previousFileInfo->NextEntryOffset = 0;
                }
                else
                {
                    previousFileInfo->NextEntryOffset = (ULONG)((PCHAR)currentFileInfo - (PCHAR)previousFileInfo) + nextOffset;
                }
                
                modified = 1;                
            }
            else
            {
                removedAllEntries = 0;
                //前驱结点指针后移 
                previousFileInfo = currentFileInfo;                
            }
            //当前指针后移 
            currentFileInfo = nextFileInfo;
        } while( nextOffset != 0 );

        if( modified )
        {
            if( removedAllEntries )
            {
                Data->IoStatus.Status = STATUS_NO_MORE_FILES;
            }
            else
            {
                FltSetCallbackDataDirty( Data );
            }
        }
    }
    
    return FLT_POSTOP_FINISHED_PROCESSING;
}

注意以上代码使用的是宏开关，只是在编译时起作用，而非运行时。要想XP和win7都可以正常隐藏文件目录需要分别编译。

要想XP和win7同时起作用，需要去掉宏开关，然后把HideFilePostDirCtrl 改成一下代码

//实现目录隐藏,支持XP及以上版本 JiaSong[2010-11-1] 
FLT_POSTOP_CALLBACK_STATUS
HideFilePostDirCtrl (
    __inout PFLT_CALLBACK_DATA Data,
    __in PCFLT_RELATED_OBJECTS FltObjects,
    __in_opt PVOID CompletionContext,
    __in FLT_POST_OPERATION_FLAGS Flags 
)
{
    ULONG nextOffset = 0;
    int modified = 0;
    int removedAllEntries = 1;    

    PFILE_BOTH_DIR_INFORMATION currentFileInfo = 0;     
     PFILE_BOTH_DIR_INFORMATION nextFileInfo = 0;    
     PFILE_BOTH_DIR_INFORMATION previousFileInfo = 0;    
     
     PFILE_ID_BOTH_DIR_INFORMATION currentFileIdInfo = 0;
    PFILE_ID_BOTH_DIR_INFORMATION nextFileIdInfo = 0;
    PFILE_ID_BOTH_DIR_INFORMATION previousFileIdInfo = 0;
    
    UNREFERENCED_PARAMETER( FltObjects );
    UNREFERENCED_PARAMETER( CompletionContext );    

    //不满足过滤条件的直接放过 
    if( FlagOn( Flags, FLTFL_POST_OPERATION_DRAINING ) || 
        Data->Iopb->MinorFunction != IRP_MN_QUERY_DIRECTORY ||
        Data->Iopb->Parameters.DirectoryControl.QueryDirectory.Length <= 0 ||
        !NT_SUCCESS(Data->IoStatus.Status))
    {
        return FLT_POSTOP_FINISHED_PROCESSING;
    }
    //XP及其以下版本，需要过滤 FileBothDirectoryInformation 类型的信息 
    if(Data->Iopb->Parameters.DirectoryControl.QueryDirectory.FileInformationClass == FileBothDirectoryInformation)
    {
        //我们可以得到一个缓存区，这个缓存里面就保留着文件夹中所有的文件信息。
        //根据这个缓存的结构遍历处理，过滤掉要隐藏的文件名就能达到隐藏的目的了 
        if (Data->Iopb->Parameters.DirectoryControl.QueryDirectory.MdlAddress != NULL)
        {//缓存地址
            currentFileInfo=(PFILE_BOTH_DIR_INFORMATION)MmGetSystemAddressForMdlSafe( 
                         Data->Iopb->Parameters.DirectoryControl.QueryDirectory.MdlAddress,
                         NormalPagePriority );            
        }
        else
         {//缓存地址
             currentFileInfo=(PFILE_BOTH_DIR_INFORMATION)Data->Iopb->Parameters.DirectoryControl.QueryDirectory.DirectoryBuffer;             
         }     
        
        if(currentFileInfo==NULL)return FLT_POSTOP_FINISHED_PROCESSING;       
        previousFileInfo = currentFileInfo;
            
        do
        {
            //Byte offset of the next FILE_BOTH_DIR_INFORMATION entry
            nextOffset = currentFileInfo->NextEntryOffset;
            //后继结点指针 
            nextFileInfo = (PFILE_BOTH_DIR_INFORMATION)((PCHAR)(currentFileInfo) + nextOffset);            

            KdPrint(("1.FileName: %S, ShortName: %S\n",currentFileInfo->FileName,currentFileInfo->ShortName));
            if(_wcsnicmp(currentFileInfo->FileName,g_prefixName,wcslen(g_prefixName))==0)
            {
                KdPrint(("1.g_prefixName: %S, currentFileInfo->FileName: %S\n",g_prefixName,currentFileInfo->FileName));
                if( nextOffset == 0 )
                {
                    previousFileInfo->NextEntryOffset = 0;
                }
                else
                {//更改前驱结点中指向下一结点的偏移量，略过要隐藏的文件的文件结点，达到隐藏目的 
                    previousFileInfo->NextEntryOffset = (ULONG)((PCHAR)currentFileInfo - (PCHAR)previousFileInfo) + nextOffset;
                }
                modified = 1;
            }
            else
            {
                removedAllEntries = 0;
                //前驱结点指针后移 
                previousFileInfo = currentFileInfo;
            }
            //当前指针后移          
            currentFileInfo = nextFileInfo;
        } while( nextOffset != 0 );
    }
    //vista或win7返回的结构不再是FileBothDirectoryInformation.而是FileIdBothDirectoryInformation
    else if(Data->Iopb->Parameters.DirectoryControl.QueryDirectory.FileInformationClass ==FileIdBothDirectoryInformation)
    {
        if (Data->Iopb->Parameters.DirectoryControl.QueryDirectory.MdlAddress != NULL)
        {
            currentFileIdInfo=(PFILE_ID_BOTH_DIR_INFORMATION)MmGetSystemAddressForMdlSafe( 
                         Data->Iopb->Parameters.DirectoryControl.QueryDirectory.MdlAddress,
                         NormalPagePriority );            
        }
        else
         {
             currentFileIdInfo=(PFILE_ID_BOTH_DIR_INFORMATION)Data->Iopb->Parameters.DirectoryControl.QueryDirectory.DirectoryBuffer;             
         }     
        
        if(currentFileIdInfo==NULL)return FLT_POSTOP_FINISHED_PROCESSING;
        previousFileIdInfo = currentFileIdInfo;
            
        do
        {
            //Byte offset of the next FILE_ID_BOTH_DIR_INFORMATION entry
            nextOffset = currentFileIdInfo->NextEntryOffset;            
               nextFileIdInfo = (PFILE_ID_BOTH_DIR_INFORMATION)((PCHAR)(currentFileIdInfo) + nextOffset);            

            KdPrint(("2.FileName: %S, ShortName: %S\n",currentFileIdInfo->FileName,currentFileIdInfo->ShortName));
            if(_wcsnicmp(currentFileIdInfo->FileName,g_prefixName,wcslen(g_prefixName))==0)
            {
                KdPrint(("2.g_prefixName: %S, currentFileInfo->FileName: %S\n",g_prefixName,currentFileIdInfo->FileName));
                if( nextOffset == 0 )
                {
                    previousFileIdInfo->NextEntryOffset = 0;
                }
                else
                {
                    previousFileIdInfo->NextEntryOffset = (ULONG)((PCHAR)currentFileIdInfo - (PCHAR)previousFileIdInfo) + nextOffset;
                }
                modified = 1;
            }
            else
            {
                removedAllEntries = 0;                
                previousFileIdInfo = currentFileIdInfo;                
            }
            currentFileIdInfo = nextFileIdInfo;
            
        } while( nextOffset != 0 );
    }
    if( modified )
    {
        if( removedAllEntries )
         {
              Data->IoStatus.Status = STATUS_NO_MORE_FILES;
          }
           else
           {
            FltSetCallbackDataDirty( Data );
        }
    }        
    return FLT_POSTOP_FINISHED_PROCESSING;
}