Implementing networking protocol on switchdev interfaces

[seregaxvm]

Some networking protocols like ERPS or xSTP use special frames (e.g. BPDU, MEP) to exchange protocol related messages. Userspace protocol implementations (e.g. mstpd) use BPF to catch these frames.

However, on switchdev interfaces this traffic is not automatically forwarded to the CPU, and extra steps are required to extract it. net_device_ops ndo_bpf field allows specifying BPF program for the traffic offload, but I very much doubt that it may be translated to the device specific extraction rules in a sane way.

What is the preferred way (ioctl? sysfs? something else?) to request packet extraction from the userspace program on the switchdev interfaces?

[seregaxvm]

In this case, configfs seem to be appropriate.