Windows NT Driver >> Assembly

Cancel IRP


參考資訊:
1. Four-F
2. Source Code
3. canceling-irps

有處理Irp就會有Cancel Irp的時候,Cancel Irp本身就是一個很複雜的課題,司徒在這一篇教學不會做深入探討,有興趣的使用者可以參考上面的參考資訊,取而代之的,司徒只是點出,在處理Irp時,使用者要意識到該Irp可能已經被Cancel掉了,作法上,也是可以切割成很多時期,如:Irp處理前,Irp處裡中,Irp處裡後,因此,在設計驅動程式時,對於Cancel機制有必要嚴謹看待,因為,BSOD常常就是這樣發生了,不過司徒在此僅針對Irp處裡前,作簡單判斷,是否User Application已經Cancel這個Irp,如果沒有被Cancel,則Complete Irp,相反地,如果被Cancel,則Cancel Irp,Cancel作法如下:
1. CancelRoutine(NULL)
2. IoCompleteRequest(STATUS_CANCELLED)

main.asm

.386p
.model flat, stdcall
option casemap:none
 
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\Macros\Strings.mac
includelib c:\masm32\lib\wxp\i386\ntoskrnl.lib

public DriverEntry

OurDeviceExtension struct
  pNextDev  PDEVICE_OBJECT ?
  stQueue   LIST_ENTRY     <>
  stDPC     KDPC           <>
  stTime    KTIMER         <>
OurDeviceExtension ends

IOCTL_QUEUE   equ CTL_CODE(FILE_DEVICE_UNKNOWN, 800h, METHOD_BUFFERED, FILE_ANY_ACCESS)
IOCTL_PROCESS equ CTL_CODE(FILE_DEVICE_UNKNOWN, 801h, METHOD_BUFFERED, 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_QUEUE   byte "IOCTL_QUEUE",0
MSG_PROCESS byte "IOCTL_PROCESS",0

.code
OnTimer proc uses ebx pDpc:PKDPC, pContext:PVOID, pArg1:PVOID, PArg2:PVOID
  mov eax, pContext
  mov eax, (DEVICE_OBJECT PTR [eax]).DeviceExtension
  lea eax, (OurDeviceExtension PTR [eax]).stQueue
  IsListEmpty eax
  .if eax == TRUE
    mov eax, pContext
    mov eax, (DEVICE_OBJECT PTR [eax]).DeviceExtension
    invoke KeCancelTimer, addr (OurDeviceExtension PTR [eax]).stTime
    invoke DbgPrint, $CTA0("Finish")
  .else
    mov eax, pContext
    mov eax, (DEVICE_OBJECT PTR [eax]).DeviceExtension
    lea eax, (OurDeviceExtension PTR [eax]).stQueue
    RemoveHeadList eax

    ; CONTAINING_RECORD 
    sub eax, _IRP.Tail.Overlay.ListEntry
    mov bl, (_IRP PTR [eax]).Cancel
    .if bl != TRUE
      mov (_IRP PTR [eax]).IoStatus.Status, STATUS_SUCCESS
      push 0
      pop (_IRP PTR [eax]).IoStatus.Information
      fastcall IofCompleteRequest, eax, IO_NO_INCREMENT
      mov eax, STATUS_SUCCESS
      invoke DbgPrint, $CTA0("Complete Irp")
    .else
      mov (_IRP PTR [eax]).CancelRoutine, NULL
      mov (_IRP PTR [eax]).IoStatus.Status, STATUS_CANCELLED
      push 0
      pop (_IRP PTR [eax]).IoStatus.Information
      fastcall IofCompleteRequest, eax, IO_NO_INCREMENT
      invoke DbgPrint, $CTA0("Cancel Irp")
    .endif
  .endif
  ret
OnTimer endp

IrpOpenClose proc pDevObj:PDEVICE_OBJECT, pIrp:PIRP
  IoGetCurrentIrpStackLocation pIrp
  movzx eax, (IO_STACK_LOCATION PTR [eax]).MajorFunction
  .if eax == IRP_MJ_CREATE
    invoke DbgPrint, $CTA0("IRP_MJ_CREATE")
  .elseif eax == IRP_MJ_CLOSE
    invoke DbgPrint, $CTA0("IRP_MJ_CLOSE")
  .endif

  mov eax, pIrp
  and (_IRP PTR [eax]).IoStatus.Information, 0
  mov (_IRP PTR [eax]).IoStatus.Status, STATUS_SUCCESS
  fastcall IofCompleteRequest, pIrp, IO_NO_INCREMENT
  mov eax, STATUS_SUCCESS
  ret
IrpOpenClose endp

IrpIOCTL proc uses ebx ecx pOurDevice:PDEVICE_OBJECT, pIrp:PIRP
  local pdx:PTR Dev_Ext
  local stTimePeriod:LARGE_INTEGER

  mov eax, pOurDevice
  push (DEVICE_OBJECT PTR [eax]).DeviceExtension
  pop pdx

  IoGetCurrentIrpStackLocation pIrp
  mov eax, (IO_STACK_LOCATION PTR [eax]).Parameters.DeviceIoControl.IoControlCode
  .if eax == IOCTL_QUEUE
    invoke DbgPrint, offset MSG_QUEUE
    
    mov ebx, pdx
    lea ebx, (OurDeviceExtension PTR [ebx]).stQueue
    mov ecx, pIrp
    lea ecx, (_IRP PTR [ecx]).Tail.Overlay.ListEntry
    InsertHeadList ebx, ecx
    IoMarkIrpPending pIrp
    mov eax, STATUS_PENDING
    ret
  .elseif eax == IOCTL_PROCESS
    invoke DbgPrint, offset MSG_PROCESS
    or stTimePeriod.HighPart, -1
    mov stTimePeriod.LowPart, -10000000
    mov ebx, pdx
    invoke KeSetTimerEx, addr (OurDeviceExtension PTR [ebx]).stTime, stTimePeriod.LowPart, stTimePeriod.HighPart, 1000, addr (OurDeviceExtension PTR [ebx]).stDPC
  .endif

  mov eax, pIrp
  mov (_IRP PTR [eax]).IoStatus.Status, STATUS_SUCCESS
  and (_IRP PTR [eax]).IoStatus.Information, 0
  fastcall IofCompleteRequest, pIrp, IO_NO_INCREMENT
  mov eax, STATUS_SUCCESS
  ret
IrpIOCTL endp

Unload proc pOurDriver:PDRIVER_OBJECT
  local szSymName:UNICODE_STRING
          
  invoke RtlInitUnicodeString, addr szSymName, offset SYM_NAME
  invoke IoDeleteSymbolicLink, addr szSymName
          
  mov eax, pOurDriver
  invoke IoDeleteDevice, (DRIVER_OBJECT PTR [eax]).DeviceObject
  ret
Unload endp
   
DriverEntry proc pOurDriver:PDRIVER_OBJECT, pOurRegistry:PUNICODE_STRING
  local pOurDevice:PDEVICE_OBJECT
  local suDevName:UNICODE_STRING
  local szSymName:UNICODE_STRING
     
  mov eax, pOurDriver
  mov (DRIVER_OBJECT PTR [eax]).MajorFunction[IRP_MJ_CREATE * (sizeof PVOID)], offset IrpOpenClose
  mov (DRIVER_OBJECT PTR [eax]).MajorFunction[IRP_MJ_CLOSE  * (sizeof PVOID)], offset IrpOpenClose
  mov (DRIVER_OBJECT PTR [eax]).MajorFunction[IRP_MJ_DEVICE_CONTROL * (sizeof PVOID)], offset IrpIOCTL
  mov (DRIVER_OBJECT PTR [eax]).DriverUnload, offset Unload
     
  invoke RtlInitUnicodeString, addr suDevName, offset DEV_NAME
  invoke RtlInitUnicodeString, addr szSymName, offset SYM_NAME
  invoke IoCreateDevice, pOurDriver, sizeof OurDeviceExtension, addr suDevName, FILE_DEVICE_UNKNOWN, 0, FALSE, addr pOurDevice
  .if eax == STATUS_SUCCESS
    mov eax, pOurDevice
    or (DEVICE_OBJECT PTR [eax]).Flags, DO_BUFFERED_IO
    and (DEVICE_OBJECT PTR [eax]).Flags, not DO_DEVICE_INITIALIZING
     
    mov eax, pOurDevice
    mov eax, (DEVICE_OBJECT PTR [eax]).DeviceExtension
    lea eax, (OurDeviceExtension PTR [eax]).stQueue
    InitializeListHead eax
 
    mov eax, pOurDevice
    mov eax, (DEVICE_OBJECT PTR [eax]).DeviceExtension
    invoke KeInitializeTimer, addr (OurDeviceExtension ptr [eax]).stTime
 
    mov eax, pOurDevice
    mov eax, (DEVICE_OBJECT PTR [eax]).DeviceExtension
    invoke KeInitializeDpc, addr (OurDeviceExtension ptr [eax]).stDPC, offset OnTimer, pOurDevice
    invoke IoCreateSymbolicLink, addr szSymName, addr suDevName
  .endif
  ret
DriverEntry endp
end DriverEntry
.end

DriverEntry()初始List以及DPC Timer,DPC Timer用來定期確認List是否還有資料需要處理,當然,使用Thread檢查或許更恰當些
IrpIOCTL()IOCTL_QUEUE代表該IOCTL會被Queue起來,稍後處理,而當收到IOCTL_PROCESS時,則啟動DPC Timer開始處理那些被Queue起來的Irp
OnTimer()處理Queue裡面的Irp,在處理前,先判斷該Irp是否已經被Cancel了

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_QUEUE   equ CTL_CODE(FILE_DEVICE_UNKNOWN, 800h, METHOD_BUFFERED, FILE_ANY_ACCESS)
IOCTL_PROCESS equ CTL_CODE(FILE_DEVICE_UNKNOWN, 801h, METHOD_BUFFERED, FILE_ANY_ACCESS)
 
.const
DEV_NAME db "\\.\MyDriver",0
 
.data?
cnt   dd ?
hFile dd ?
dwRet dd ?
event dd 3 dup(?)
ov OVERLAPPED <?>

.code
start:
  invoke CreateFile, offset DEV_NAME, GENERIC_READ or GENERIC_WRITE, FILE_SHARE_READ, 0, OPEN_EXISTING, FILE_FLAG_OVERLAPPED or FILE_ATTRIBUTE_NORMAL, 0
  .if eax == INVALID_HANDLE_VALUE
    invoke crt_printf, $CTA0("failed to open mydriver\n")
    invoke ExitProcess, -1
  .endif
  mov hFile, eax
  invoke crt_memset, offset ov, 0, sizeof OVERLAPPED
  
  mov cnt, 3
  .while cnt > 0
    invoke CreateEvent, NULL, TRUE, FALSE, NULL
    push eax
    pop ov.hEvent
    
    mov ecx, cnt
    mov edi, offset event
    mov [edi + ecx * 4], eax
    
    invoke crt_printf, $CTA0("queue event\n")
    invoke DeviceIoControl, hFile, IOCTL_QUEUE, NULL, 0, NULL, 0, offset dwRet, offset ov
    invoke CloseHandle, ov.hEvent
    sub cnt, 1
  .endw
  
  invoke crt_printf, $CTA0("process all of events\n")
  invoke DeviceIoControl, hFile, IOCTL_PROCESS, NULL, 0, NULL, 0, offset dwRet, NULL
  invoke Sleep, 1000
  invoke CancelIo, hFile
  
  mov cnt, 3
  .while cnt > 0
    mov ecx, cnt
    mov edi, offset event
    mov eax, [edi + ecx * 4]
     
    push eax
    pop ov.hEvent
     
    invoke WaitForSingleObject, ov.hEvent, INFINITE
    invoke CloseHandle, ov.hEvent
    invoke crt_printf, $CTA0("wait complete\n")
    sub cnt, 1
  .endw
  
  invoke CloseHandle, hFile
  invoke ExitProcess, 0
end start

結果


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