Current U32 filter only supports redirect action, but the U32 can
support a lot more. Refactor a bit the action generating/parsing logic
to be more generic and add BPF action support.
When creating a U32 filter, one can supply an array of Actions, which
will be executed by the U32 filter in order:
* The new MirredAction implements the same functionality as RedirIndex
field in the U32 filter, with that static field kept in the struct for
backwards compatibility.
* A new BpfAction type is added which allows a program with an open bpf
file descriptor (implementation is out of scope of this patch) to be
added as well.
Add a test for the above use case which includes one of each type of
action.
Brenden Blanco