static int tipc_listen(struct socket *sock, int len)
{
	struct sock *sk = sock->sk;
	int res;

	lock_sock(sk);

	if (sock->state != SS_UNCONNECTED)
		res = -EINVAL;
	else {
		sock->state = SS_LISTENING;
		res = 0;
	}

	release_sock(sk);
	return res;
}

Unknown