t, uintptr(unsafe.Pointer(&args)), 0)  if err != 0 {   return 0, err  }  return int(fd), nil }  func getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) error {  args := [0]uintptr{uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(unsafe.Pointer(vallen))