EBADF The s argument is not a valid socket descriptor. EINTR A signal was caught during the ioctl() operation. If an underlying device driver detects an error, errno might be set to one of the following values: EINVAL Either the request or the arg argument is not valid. ENOTTY Reserved for HP use. The s argument is not associated with a network device, or the specified request does not apply to the specific network device. ENXIO The request and arg arguments are valid for this device driver, but the service requested cannot be performed on the device.