3.2.5.38.8 Receiving a TRANS_READ_NMPIPE Response
Upon receipt of a TRANS_READ_NMPIPE subcommand response, the client MUST forward the ReadData buffer and the number of bytes read from the named pipe to the application. The number of bytes read (the size of ReadData ) is returned in the TotalDataCount field.
In the event of a STATUS_BUFFER_OVERFLOW (ERRDOS/ERRmoredata) error, the server MUST return a complete SMB_COM_TRANSACTION response (not an error response) indicating that a message was incompletely read. The TotalDataCount in the TRANS_READ_NMPIPE contained in the SMB_COM_TRANSACTION response indicates the number of bytes successfully read.