Front end scripts

Front end scripts are inline in the fast path.

Because frontend scripts are in the fast path. You need to use T.async methods to perform I/O in a separate slow path provided by the Trisul framework.

List of frontend script types

You can hook your lua scripts into the following points in the frontend.

Name Called when Notes
countergroup During initialization Create a new counter group
simplecounter Each packet Inspect packet contents and update meter/alerts
flowmonitor When interesting data is seen per flow Inspect HTTP headers, TLS certs, then attach counters to flows
fileextract Events in HTTP layer Flexible platform to extract files transferred via HTTP
reassembly TCP reassembly Control and process output from Trisul’s TCP reassembly engine