__tcp_send_ack
void __tcp_send_ack(struct sock *sk, u32 rcv_nxt, u16 flags);
__tcp_send_ack((struct sock *)tp, rcv_nxt, 0);
__tcp_send_ack(sk, *prior_rcv_nxt, 0);
__tcp_send_ack(sk, tp->rcv_nxt, flags);
EXPORT_SYMBOL_GPL(__tcp_send_ack);
__tcp_send_ack(sk, tcp_sk(sk)->rcv_nxt, 0);