Semi-Automated Protocol Disambiguation and Code Generation

For decades, Internet protocols have been specified using natural language. Given the ambiguity inherent in such text, it is not surprising that over the years protocol implementations exhibited bugs and non-interoperabilities. In this paper, we explore to what extent natural language processing (NLP), an area that has made impressive strides in recent years, can be used to generate protocol implementations. We advocate a semi-automated protocol generation approach, Sage, that can be used to uncover ambiguous or under-specified sentences in specifications; these can then be fixed by a human iteratively until Sage is able to generate protocol code automatically. Using an implementation of Sage, we discover 5 instances of ambiguity and 6 instances of under-specification in the ICMP RFC, after fixing which Sage is able to generate code automatically that interoperates perfectly with Linux implementations. We demonstrate the ability to generalize Sage to parts of IGMP and NTP. We also find that Sage supports half of the conceptual components found in major standards protocols; this suggests that, with some additional machinery, Sage may be able to generalize to TCP and BGP.