sk_probe
int sk_probe(struct device *, void *, void *);
sizeof(struct sk_if_softc), sk_probe, sk_attach, sk_detach,
sk = sk_probe(NULL, NULL, 0, 0);
sk = sk_probe(application, key_handle, key_handle_len, 0);
sk = sk_probe(NULL, NULL, 0, 1);
sk = sk_probe(NULL, NULL, 0, 0);