Libbpf userspace function bpf_map__ifindex
Get the interface index associated with the BPF map.
Definition
__u32 bpf_map__ifindex(const struct bpf_map *map);
Parameters
map: Pointer to the BPF map.
Return
Interface index associated with the map. Or 0 if no interface index is available.
Usage
When offloading XDP programs to the hardware, any BPF map that is used by the XDP program is also offloaded to the hardware. Since the driver might impose restrictions on maps, the interface index on which the program/map will be offloaded is associated with it, so the driver for that interface can be looped in during map loading.
Example
Docs could be improved
This part of the docs is incomplete, contributions are very welcome