基于Wireshark二次开发的地铁信号系统应用协议解析插件

Wireshark Based Plugin Implementation on Railway Signal System Application Data's Dissection

随着软件技术的快速发展,其在地铁信号系统中应用也愈来愈广泛。新技术给地铁系统设计带来了极大的便利和灵活性。目前地铁信号系统设计过程中尚未实现互联互通,各家系统之间使用的通信协议各不相同。虽然目前地铁信号系统的信息交换网络层都已经采用了标准的IP协议,关系到各子系统之间所采用的应用协议仍然是私有协议,在对这些私有协议进行测试验证时,只能基于私有的应用协议逐字节或者比特来进行判断,这种方法工作量大且容易出错,极大地降低了系统集成测试的效率。描述了基于wireshark的开放性架构,利用脚本语言lua实现地铁信号系统子系统的私有协议解析实现,以对子系统之间的应用数据进行在线解析,极大地提高了测试执行过程中的效率。同时这些脚本充分利用了wireshark提供的网络抓包功能,大大地降低了开发周期。

With the rapid development of software technology, the software technology is widely used in Railway Signaling system, which brings great convenience and flexibility to the signal system design. So far the Railway signal system＇s interconnection is not achieved. Despite using IP protocol as the unified network protocol, the application layer is different between signal companies. The verification on the message exchange between different subsystem, comparison on byte or bit shall be done, which is a costly work. This article describes a script implementation of packet dissection for a private protocol based on the analysis of wireshark and Lua language. This method saves a lot of effort and leading time, improves the test efficiency. At the same time, it saves the development effort and time by taking full advantage of wireshark＇s own functionality - IP packet capture.