Re: [PATCH] net:ipv4: send an ack when seg.ack > snd.nxt

[Florian Westphal]

zhouzhouyi@xxxxxxxxx <zhouzhouyi@xxxxxxxxx> wrote:
> -	if (after(ack, tp->snd_nxt))
> +	if (after(ack, tp->snd_nxt)) {
> +		tcp_send_ack(sk);
>  		return -1;
> +	}

If we really need to do this we need to
  if (!(flag & FLAG_NO_CHALLENGE_ACK))
	tcp_send_challenge_ack(sk);

... else this might result in two acks?
Whats the problem thats being fixed here?