BUG: CallNamedPipe() API lpBytesRead Parameter Returns Bogus Number (235717)


The information in this article applies to:

  • Microsoft Windows 98, when used with:
    • the operating system: Microsoft Windows 98
  • Microsoft Windows 98 Second Edition
This article was previously published under Q235717

SYMPTOMS

When you use the CallNamedPipe() API on Windows 98 to communicate to a message-based Named Pipe on a Windows NT computer, the lpBytesRead parameter which specifies the actual amount of bytes written into the read buffer lpOutBuffer returns a number, which does not reflect the amount of bytes in the buffer. This number is typically a very large number. It should be noted though, that the read buffer will still contain the received data on a successful call.

CAUSE

The SMB used for the named pipe is read incorrectly by Windows 98 for the CallNamedPipe() API.

RESOLUTION

If the number of bytes written lpBytesRead into the read buffer is required, a traditional CreateFile()/WriteFile()/ReadFile() sequence of using a named pipe or the TransactNamedPipe() API can be used. Alternatively, the following code can be used to mimic the behavior of the CallNamedPipe() API: 
BOOL MimicCallNamedPipe(
  LPCTSTR lpNamedPipeName,  // pointer to pipe name
  LPVOID lpInBuffer,        // pointer to write buffer
  DWORD nInBufferSize,      // size, in bytes, of write buffer
  LPVOID lpOutBuffer,       // pointer to read buffer
  DWORD nOutBufferSize,     // size, in bytes, of read buffer
  LPDWORD lpBytesRead,      // pointer to number of bytes read
  DWORD nTimeOut            // time-out value, in milliseconds
)
{
  HANDLE hPipe = INVALID_HANDLE_VALUE;
  DWORD dwPipeMode = PIPE_READMODE_MESSAGE | PIPE_WAIT;

  if (WaitNamedPipe(lpNamedPipeName, nTimeOut) == FALSE)
    return FALSE;

  hPipe = CreateFile(lpNamedPipeName, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
  if (hPipe == INVALID_HANDLE_VALUE)
    return FALSE;
      
  if (SetNamedPipeHandleState(hPipe, &dwPipeMode, NULL, NULL) == FALSE)
    return FALSE;
    
  if (TransactNamedPipe(hPipe, lpInBuffer, nInBufferSize, lpOutBuffer, nOutBufferSize, lpBytesRead, NULL) == FALSE)
    return FALSE;

  CloseHandle(hPipe);

  return TRUE;
}
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http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

STATUS

Microsoft has confirmed that this is a bug in the Microsoft products that are listed at the beginning of this article.

REFERENCES

Please see the latest Platform SDK for more information on Named Pipes.
Modification Type:MajorLast Reviewed:6/23/2005
Keywords:kbDSWNET2003Swept kbAPI kbBug kbIPC kbnetwork kbPipes KB235717
©2004 Microsoft Corporation. All rights reserved.