sk_wait_data
int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
EXPORT_SYMBOL(sk_wait_data);
err = sk_wait_data(sk, &timeo, last);
ret = sk_wait_data(sk, &timeo, NULL);
if (sk_wait_data(sk, &timeo, NULL))
sk_wait_data(sk, &timeo, NULL);
err = sk_wait_data(sk, &timeo, last);
ret = sk_wait_data(sk, &timeo, NULL);
sk_wait_data(clcsk, &timeo, NULL);