Question

如何在发送之前修改数据包上的某些字节？我正在执行以下代码：

function WSASendHookProc(s: TSocket; var lpBuffers; dwBufferCount: DWORD; var lpNumberOfBytesSent: DWORD; dwFlags: DWORD; lpOverlapped: LPWSAOVERLAPPED; lpCompletionRoutine: LPWSAOVERLAPPED_COMPLETION_ROUTINE): Integer; stdcall;
var
  DataBuffer    : PChar;
  DataS         : TSocket;
begin
  Result := 0; (here already tried call the TramplineWSASend, dwBufferCount, lpNumberOfBytesSent and still the same thing)
  DataS  := s;

  GetMem(DataBuffer, Result);
  try
    CopyMemory(DataBuffer, @lpBuffers, Result);
    //word(pointer(DataBuffer)^) := word(pointer(DataBuffer)^);
    CopyMemory(@lpBuffers, DataBuffer, Result);
  finally
    FreeMem(DataBuffer);
  end;

  Result := TrampolineWSASend(s, lpBuffers, dwBufferCount, lpNumberOfBytesSent, dwFlags, lpOverlapped, lpCompletionRoutine);
end;

但在//word(pointer(DataBuffer)^) := word(pointer(DataBuffer)^);行，如果删除//应用程序崩溃而没有显示任何错误。但是现在，如果我不删除//应用程序就可以了，但是我无法修改字节。

Answer 1

您需要使用GetMem(DataBuffer, dwBufferCount); 这将分配缓冲区所需的内存。

然后您复制缓冲区：

CopyMemory(DataBuffer, lpBuffers, dwBufferCount);

现在您可以从DataBuffer编辑内存，例如：

PWord(DataBuffer)^ := Word(Your word value here);

然后在TrampolineWSASend中，您需要将lpBuffers替换为DataBuffer。

发送前如何更改数据包上的字节

1 个答案: