Add a small utility that uses a kprobe to extract the currently active
slave ifindex from a bond interface. This value is normally only exported
to userspace for bond types where it can be explicitly set, but the bond
driver has an internal notion of an active interface regardless of the bond
type. We can extract this value with a kprobe by attaching to a function in
the bond driver and triggering an operation that causes this function to be
called.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
This makes it easier to populate the global variables we'll need for
handling multicast, and also means we don't have to worry about keeping the
BPF object file around (since it'll be statically linked).
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Add an example to filter looping packets on (for instance) a bond
interface, by recording the egress MAC+VLAN and dropping any packets that
come in on other (related) interfaces with the same MAC+VLAN.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>