A Language-Based Approach for Improving the Robustness of Network Application Protocol Implementations

The secure and robust functioning of a network relies on the defect-free implementation of network applications. As network protocols have become increasingly complex, however, hand-writing network message processing code has become increasingly error-prone. In this paper, we present a domain-specific language, Zebu, for generating robust and efficient message processing layers. A Zebu specification, based on the notation used in RFCs, describes protocol message formats and related processing constraints. Zebu-based applications are efficient, since message fragments can be specified to be processed on demand. Zebu-based applications are also robust, as the Zebu compiler automatically checks specification consistency and generates parsing stubs that include validation of the message structure. Using a message torture suite in the context of SIP and RTSP, we show that Zebu-generated code is both complete and defect-free.