An extensible protocol-processing code generator from definitions of application-layer protocols

Server/client programs for Internet services have to be updated every time application-layer protocols are revised, e.g., from HTTP/1.0 to HTTP/1.1, to cope with the extensions. This makes it difficult to properly maintain the server/client programs. To resolve this problem, this paper proposes a system that automatically generates protocol processing codes for both server and client programs from the descriptions of the server/client's state transitions, which are caused by message exchanges between a server and a client. The proposed system introduces two mechanisms, namely inheritance and override of state transitions, that enable us to specify only the differences between the old and new versions of the protocols. Using this system, both server and client programs are expected to be easier to reuse and maintain.