Binder interface for wpa_supplicant?

[Christopher Wiley]

The WiFi group in Android is interested in developing a control interface
for wpa_supplicant based on binder (Android’s native IPC system). This is
chiefly desirable so that we can get a reasonable RPC interface with
generated marshaling logic (no string parsing or handwritten boilerplate on
either side).

We would love to send patches upstream if there is interest in keeping this
implementation in-repository. The intent is to keep IPC and communication
logic separate from core logic by using existing abstractions or
introducing new ones where appropriate. The tentative plan is to parallel
the existing pair of DBus interface implementations, but thoughts on how to
best express this are appreciated.

It is difficult to know exactly how much technical detail to give, and I
can go into more detail as desired. Binder refers to a system where
processes send messages to objects in other processes through the binder
kernel driver. Think KDBus but much more lightweight. The binder driver
supports polling, and it should be straightforward to handle command
interface related messages as a handler registered with the supplicant
event loop. Event delivery would use a pattern where interested parties
call the command interface to register a binder object to receive
notifications on. It seems likely that we could remove a lot of the android
specific logic (guarded with #ifdef ANDROID) in favor of a little top level
“which IPC interface” build configuration.

wiley