如何从服务中收到OutputDebugString？ [英] How can I receive OutputDebugString from service?

问题描述

我正在抓住所有 OutputDebugString 讯息（包括来自服务的）使用以下代码。它工作正常，直到我迁移到Windows 7.问题是，由于Windows Vista服务运行在低级Session＃0有人说，这是不可能的抓住他们和一些它是。你怎么看 ？可以通过增加一些权限来修改以下代码： OutputDebugString 来自Session＃0的消息？换一种说法;可以在Session＃1的会话＃0中共享DBWIN_BUFFER吗？

I'm trying to catch all OutputDebugString messages (including those from services) using the following code. It worked fine until I migrated to Windows 7. The problem is that since Windows Vista services are running in the low level Session #0 some people says that it's impossible to catch them and some that it is. What do you think ? Is it possible to modify the following code by increasing some rights to be able to receive OutputDebugString messages from the Session #0 ? In other words; is it possible to share DBWIN_BUFFER in the session #0 with Session #1 ?

我认为应该是可能的，因为例如DebugView可以做到这一点，我看不到任何服务助手将把这些消息（例如通过命名管道）从会话＃0发送到会话＃1，GUI运行。

I would say it should be possible because e.g. DebugView can do that and I can't see any service helper which would send those messages (e.g. through the named pipes) from the Session #0 to Session #1, where the GUI's running.

问题将在安全设置中是IMO。任何人都可以建议我如何修改它们？

The problem will be IMO in the security settings. Can anyone suggest me how to modify them ?

type
  TODSThread = class(TThread)
  protected
    procedure Execute; override;
  end;

...

procedure TODSThread.Execute;
var SharedMem: Pointer;
    SharedFile: THandle;
    WaitingResult: DWORD;
    SharedMessage: string;
    DataReadyEvent: THandle;
    BufferReadyEvent: THandle;
    SecurityAttributes: SECURITY_ATTRIBUTES;
    SecurityDescriptor: SECURITY_DESCRIPTOR;

begin
  SecurityAttributes.nLength := SizeOf(SECURITY_ATTRIBUTES);
  SecurityAttributes.bInheritHandle := True;
  SecurityAttributes.lpSecurityDescriptor := @SecurityDescriptor;

  if not InitializeSecurityDescriptor(@SecurityDescriptor, SECURITY_DESCRIPTOR_REVISION) then
    Exit;

  if not SetSecurityDescriptorDacl(@SecurityDescriptor, True, nil, False) then
    Exit;

  BufferReadyEvent := CreateEvent(@SecurityAttributes, False, True, 'DBWIN_BUFFER_READY');

  if BufferReadyEvent = 0 then
    Exit;

  DataReadyEvent := CreateEvent(@SecurityAttributes, False, False, 'DBWIN_DATA_READY');

  if DataReadyEvent = 0 then
    Exit;

  SharedFile := CreateFileMapping(THandle(-1), @SecurityAttributes, PAGE_READWRITE, 0, 4096, 'DBWIN_BUFFER');

  if SharedFile = 0 then
    Exit;

  SharedMem := MapViewOfFile(SharedFile, FILE_MAP_READ, 0, 0, 512);

  if not Assigned(SharedMem) then
    Exit;

  while (not Terminated) and (not Application.Terminated) do
    begin
      SetEvent(BufferReadyEvent);
      WaitingResult := WaitForSingleObject(DataReadyEvent, INFINITE);

      case WaitingResult of
        WAIT_TIMEOUT: Continue;
        WAIT_OBJECT_0:
          begin
            SharedMessage := String(PAnsiChar(SharedMem) + SizeOf(DWORD));
            // here I have what I need and process it in the main thread
          end;

       WAIT_FAILED: Continue;
     end;
   end;

   UnmapViewOfFile(SharedMem);
   CloseHandle(SharedFile);
end;

我添加了C＃标签，即使代码在Delphi中，因为安全属性对于整个Windows API和C＃有很多追随者：）

I've added C# tag even if the code is in Delphi because the security attributes are common for the whole Windows API and C# has many followers :)

感谢任何建议

推荐答案

有人在 SysInternals论坛中讨论同样的问题。他们的解决方案是将Global\添加到命名对象。

Someone talked about the same issue in the SysInternals forums. Their solution was to add "Global\" to the named objects.

所以使用以下

CreateEvent(@SecurityAttributes, False, True, 'Global\DBWIN_BUFFER_READY');
CreateEvent(@SecurityAttributes, False, False, 'Global\DBWIN_DATA_READY');
CreateFileMapping(THandle(-1), @SecurityAttributes, PAGE_READWRITE, 0, 4096, 'Global\DBWIN_BUFFER');

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