// an interface index or a set of interface flags. In most cases, zero
// means a wildcard.
func FetchRIB(af int, typ RIBType, arg int) ([]byte, error) {
	try := 0
	for {
		try++
		mib := [6]int32{syscall.CTL_NET, syscall.AF_ROUTE, 0, int32(af), int32(typ), int32(arg)}
		n := uintptr(0)
		if err := sysctl(mib[:], nil, &n, nil, 0); err != nil {
			return nil, os.NewSyscallError("sysctl", err)
		}
		if n == 0 {

// which consists of network facility information, states and
// parameters.
//
// Deprecated: Use golang.org/x/net/route instead.
func RouteRIB(facility, param int) ([]byte, error) {
	mib := []_C_int{CTL_NET, AF_ROUTE, 0, 0, _C_int(facility), _C_int(param)}
	// Find size.
	n := uintptr(0)
	if err := sysctl(mib, nil, &n, nil, 0); err != nil {
		return nil, err
	}
	if n == 0 {
		return nil, nil
	}