Kernel Mode Driver Framework >> Assembly (PNP) >> IOCTL

METHOD_IN_DIRECT、METHOD_OUT_DIRECT


參考資訊:
1. Source Code

METHOD_IN_DIRECT、METHOD_OUT_DIRECT的作法就是直接Mapping User Buffer,然後驅動程式使用該Mapped的MDL(Memory Description List)操作,相較於METHOD_BUFFERED,因為不須I/O Manager更新回User Buffer,因此,效率會比較好,而相比File的WdfDeviceIoDirect,IOCTL細分成IN和OUT兩種,這是因為IOCTL有區分Input和Output Buffer的緣故,因此,會有方向性的考量,Microsoft針對這部份的描述,僅說明MDL描述會有讀寫存取方向的區分,但是司徒實際測試,發現DeviceIoControl()的Input和Output Buffer是可以混用的,意思就是Input Buffer可以充當Input或Output Buffer使用,而Output Buffer也可以充當Input或Output Buffer使用,只要驅動程式跟User Application定義好即可,當然,METHOD_IN_DIRECT和METHOD_OUT_DIRECT也是可以混用的,關於這部份的細節,有興趣的使用者可以研讀WRK代碼,不過,深怕未知問題可能發生,建議還是依照Microsoft規定去撰寫驅動程式會比較保險。

Microsoft針對I/O部份的說明:
buffer-descriptions-for-i-o-control-codes

記憶體指標:

Buffer Length
Input Step 1. WdfRequestRetrieveInputWdmMdl()
Step 2. MmGetSystemAddressForMdlSafe()
傳入的第四個參數
Output Step 1. WdfRequestRetrieveOutputWdmMdl()
Step 2. MmGetSystemAddressForMdlSafe()
傳入的第三個參數

main.asm

.386p
.model flat, stdcall
option casemap:none

include c:\masm32\Macros\Strings.mac
include c:\masm32\include\w2k\ntdef.inc
include c:\masm32\include\w2k\ntstatus.inc
include c:\masm32\include\w2k\ntddk.inc
include c:\masm32\include\w2k\ntoskrnl.inc
include c:\masm32\include\w2k\ntddkbd.inc
include c:\masm32\include\wxp\wdm.inc
include c:\masm32\include\wdf\umdf\1.9\wudfddi_types.inc
include c:\masm32\include\wdf\kmdf\1.9\wdf.inc
include c:\masm32\include\wdf\kmdf\1.9\wdftypes.inc
include c:\masm32\include\wdf\kmdf\1.9\wdfglobals.inc
include c:\masm32\include\wdf\kmdf\1.9\wdffuncenum.inc
include c:\masm32\include\wdf\kmdf\1.9\wdfobject.inc
include c:\masm32\include\wdf\kmdf\1.9\wdfdevice.inc
include c:\masm32\include\wdf\kmdf\1.9\wdfdriver.inc
include c:\masm32\include\wdf\kmdf\1.9\wdfrequest.inc
include c:\masm32\include\wdf\kmdf\1.9\wdfio.inc
include c:\masm32\include\wdf\kmdf\1.9\wdfmemory.inc

includelib c:\masm32\lib\wxp\i386\BufferOverflowK.lib 
includelib c:\masm32\lib\wxp\i386\ntoskrnl.lib 
includelib c:\masm32\lib\wxp\i386\hal.lib 
includelib c:\masm32\lib\wxp\i386\wmilib.lib 
includelib c:\masm32\lib\wxp\i386\sehupd.lib 
includelib c:\masm32\lib\wdf\kmdf\i386\1.9\wdfldr.lib
includelib c:\masm32\lib\wdf\kmdf\i386\1.9\wdfdriverentry.lib

public DriverEntry
IOCTL_GET equ CTL_CODE(FILE_DEVICE_UNKNOWN, 800h, METHOD_OUT_DIRECT, FILE_ANY_ACCESS)
IOCTL_SET equ CTL_CODE(FILE_DEVICE_UNKNOWN, 801h, METHOD_IN_DIRECT, FILE_ANY_ACCESS)

.const
DEV_NAME word "\","D","e","v","i","c","e","\","M","y","D","r","i","v","e","r",0
SYM_NAME word "\","D","o","s","D","e","v","i","c","e","s","\","M","y","D","r","i","v","e","r",0
MSG_GET byte "IOCTL_GET",0
MSG_SET byte "IOCTL_SET",0

.data
szBuffer byte 255 dup(0)

.code
IrpFileCreate proc Device:WDFDEVICE, Request:WDFREQUEST, FileObject:WDFFILEOBJECT
  invoke DbgPrint, $CTA0("IrpFieCreate")
  invoke WdfRequestComplete, Request, STATUS_SUCCESS
  ret
IrpFileCreate endp

IrpFileClose proc FileObject:WDFFILEOBJECT
  invoke DbgPrint, $CTA0("IrpFieClose")
  ret
IrpFileClose endp

IrpIOCTL proc Queue:WDFQUEUE, Request:WDFREQUEST, OutputBufferLength:DWORD, InputBufferLength:DWORD, IoControlCode:DWORD
  local mdl:PMDL
  
  .if IoControlCode == IOCTL_SET
    invoke DbgPrint, offset MSG_SET
    invoke WdfRequestRetrieveInputWdmMdl, Request, addr mdl
    MmGetSystemAddressForMdlSafe mdl, LowPagePriority
    invoke memcpy, offset szBuffer, eax, InputBufferLength
    invoke DbgPrint, $CTA0("Buffer: %s, Length:%d"), offset szBuffer, InputBufferLength
    invoke WdfRequestSetInformation, Request, InputBufferLength
  .elseif IoControlCode == IOCTL_GET
    invoke DbgPrint, offset MSG_GET
    invoke WdfRequestRetrieveOutputWdmMdl, Request, addr mdl
    MmGetSystemAddressForMdlSafe mdl, LowPagePriority
    invoke memcpy, eax, offset szBuffer, OutputBufferLength
    invoke strlen, offset szBuffer
    inc eax
    invoke WdfRequestSetInformation, Request, eax
  .endif
  invoke WdfRequestComplete, Request, STATUS_SUCCESS
  ret
IrpIOCTL endp

AddDevice proc Driver:WDFDRIVER, pDeviceInit:PWDFDEVICE_INIT
  local device:WDFDEVICE
  local suDevName:UNICODE_STRING
  local szSymName:UNICODE_STRING
  local file_cfg:WDF_FILEOBJECT_CONFIG
  local ioqueue_cfg:WDF_IO_QUEUE_CONFIG

  invoke RtlInitUnicodeString, addr suDevName, offset DEV_NAME
  invoke RtlInitUnicodeString, addr szSymName, offset SYM_NAME
  invoke WdfDeviceInitAssignName, pDeviceInit, addr suDevName
  invoke WdfDeviceInitSetIoType, pDeviceInit, WdfDeviceIoBuffered
  invoke WDF_FILEOBJECT_CONFIG_INIT, addr file_cfg, offset IrpFileCreate, offset IrpFileClose, NULL
  invoke WdfDeviceInitSetFileObjectConfig, pDeviceInit, addr file_cfg, WDF_NO_OBJECT_ATTRIBUTES
  invoke WdfDeviceCreate, addr pDeviceInit, WDF_NO_OBJECT_ATTRIBUTES, addr device
  invoke WdfDeviceCreateSymbolicLink, device, addr szSymName
  invoke WDF_IO_QUEUE_CONFIG_INIT_DEFAULT_QUEUE, addr ioqueue_cfg, WdfIoQueueDispatchSequential
  lea eax, ioqueue_cfg
  mov (WDF_IO_QUEUE_CONFIG ptr [eax]).EvtIoDeviceControl, offset IrpIOCTL
  invoke WdfIoQueueCreate, device, addr ioqueue_cfg, WDF_NO_OBJECT_ATTRIBUTES, WDF_NO_HANDLE
  ret
AddDevice endp

DriverEntry proc pOurDriver:PDRIVER_OBJECT, pOurRegistry:PUNICODE_STRING
  local config:WDF_DRIVER_CONFIG
  
  invoke WDF_DRIVER_CONFIG_INIT, addr config, AddDevice
  invoke WdfDriverCreate, pOurDriver, pOurRegistry, WDF_NO_OBJECT_ATTRIBUTES, addr config, WDF_NO_HANDLE
  ret
DriverEntry endp
end DriverEntry
.end

IrpIOCTL()收到IOCTL_SET時,Driver複製User Buffer的內容到szBuffer,而收到IOCTL_GET時,將szBuffer內容又複製回User Buffer,完成暫存的功能,IoStatus.Information的數值就是OutBufferSize回傳的長度。

app.asm

.386p
.model flat, stdcall
option casemap:none

include c:\masm32\include\windows.inc
include c:\masm32\include\masm32.inc
include c:\masm32\include\user32.inc
include c:\masm32\include\msvcrt.inc
include c:\masm32\include\kernel32.inc
include c:\masm32\include\w2k\ntddkbd.inc
include c:\masm32\Macros\Strings.mac
 
includelib c:\masm32\lib\user32.lib
includelib c:\masm32\lib\masm32.lib
includelib c:\masm32\lib\msvcrt.lib
includelib c:\masm32\lib\kernel32.lib

IOCTL_GET equ CTL_CODE(FILE_DEVICE_UNKNOWN, 800h, METHOD_OUT_DIRECT, FILE_ANY_ACCESS)
IOCTL_SET equ CTL_CODE(FILE_DEVICE_UNKNOWN, 801h, METHOD_IN_DIRECT, FILE_ANY_ACCESS)
 
.const
DEV_NAME db "\\.\MyDriver",0
 
.data?
hFile    dd ?
dwRet    dd ?
szBuffer db 255 dup(?)
 
.code
start:
  invoke CreateFile, offset DEV_NAME, GENERIC_READ or GENERIC_WRITE, FILE_SHARE_READ, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0
  .if eax == INVALID_HANDLE_VALUE
    invoke crt_printf, $CTA0("failed to open mydriver")
    invoke ExitProcess, -1
  .endif
  
  mov hFile, eax
  invoke wsprintf, offset szBuffer, $CT0("I am error")
  invoke StrLen, offset szBuffer
  inc eax
  mov dwRet, eax
  invoke crt_printf, $CTA0("SET: %s, %d\n"), offset szBuffer, dwRet
  invoke DeviceIoControl, hFile, IOCTL_SET, offset szBuffer, dwRet, NULL, 0, offset dwRet, NULL
  invoke crt_memset, offset szBuffer, 0, 255
  invoke DeviceIoControl, hFile, IOCTL_GET, NULL, 0, offset szBuffer, 255, offset dwRet, NULL
  invoke crt_printf, $CTA0("GET: %s, %d\n"), offset szBuffer, dwRet
  invoke CloseHandle, hFile
  invoke ExitProcess, 0
  
end start

結果


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