get_random_bytes
void get_random_bytes(void *, size_t);
get_random_bytes(&v, sizeof(v));
get_random_bytes(ni->ni_challenge,
get_random_bytes(&r, 2);
get_random_bytes(ni->ni_bssid, IEEE80211_ADDR_LEN);
get_random_bytes(&ctx->wc_iv, sizeof(ctx->wc_iv));