static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
	struct sock *sk = sock->sk;
	long amount = 0;
	int err;

	switch (cmd) {
	case SIOCOUTQ:
		amount = unix_outq_len(sk);
		err = put_user(amount, (int __user *)arg);
		break;
	case SIOCINQ:
		amount = unix_inq_len(sk);
		if (amount < 0)
			err = amount;
		else
			err = put_user(amount, (int __user *)arg);
		break;
	default:
		err = -ENOIOCTLCMD;
		break;
	}
	return err;
}
Unknown