if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
                wake_up_interruptible_sync(sk->sk_sleep);
 
-       tun = container_of(sk, struct tun_sock, sk)->tun;
+       tun = tun_sk(sk)->tun;
        kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
 }
 
 static void tun_sock_destruct(struct sock *sk)
 {
-       free_netdev(container_of(sk, struct tun_sock, sk)->tun->dev);
+       free_netdev(tun_sk(sk)->tun->dev);
 }
 
 static struct proto tun_proto = {
                sk->sk_write_space = tun_sock_write_space;
                sk->sk_sndbuf = INT_MAX;
 
-               container_of(sk, struct tun_sock, sk)->tun = tun;
+               tun_sk(sk)->tun = tun;
 
                security_tun_dev_post_create(sk);