Proxy filter API

freerdp-proxy has an API for filtering certain messages. A filter can register callbacks to events, allowing to record the data and control whether to pass/ignore the message, or right out drop the connection.

During startup, the proxy loads its filters from the configuration:

1 [Filters]
2 ; FilterName = FilterPath
3 DemoFilter = "server/proxy/"

Currently supported events

  • Mouse event
  • Keyboard event

Developing a new filter

  • Create a new file that includes filters_api.h.
  • Implement the filter_init function and register the callbacks you are interested in.
  • Each callback receives two parameters:
    • connectionInfo* info holds connection info of the raised event.
    • void* param holds the actual event data. It should be casted by the filter to the suitable struct from filters_api.h.
  • Each callback must return a PF_FILTER_RESULT:
    • FILTER_IGNORE: The event will not be proxied.
    • FILTER_PASS: The event will be proxied.
    • FILTER_DROP: The entire connection will be dropped.

A demo can be found in filter_demo.c.