Xinming Hu <huxinming820@xxxxxxxxx> writes:
> From: Xinming Hu <huxm@xxxxxxxxxxx>
>
> Tcp ack should be send as soon to avoid throuput drop during receive tcp
> traffic.
>
> Signed-off-by: Xinming Hu <huxm@xxxxxxxxxxx>
> Signed-off-by: Cathy Luo <cluo@xxxxxxxxxxx>
> Signed-off-by: Ganapathi Bhat <gbhat@xxxxxxxxxxx>
[...]
> +static bool is_piggyback_tcp_ack(struct sk_buff *skb)
> +{
> + struct ethhdr *ethh = NULL;
> + struct iphdr *iph = NULL;
> + struct tcphdr *tcph = NULL;
> +
> + ethh = (struct ethhdr *)skb->data;
> + if (ntohs(ethh->h_proto) != ETH_P_IP)
> + return false;
> +
> + iph = (struct iphdr *)((u8 *)ethh + sizeof(struct ethhdr));
> + if (iph->protocol != IPPROTO_TCP)
> + return false;
> +
> + tcph = (struct tcphdr *)((u8 *)iph + iph->ihl * 4);
> + /* Piggyback ack without payload*/
> + if (*((u8 *)tcph + 13) == 0x10 &&
> + ntohs(iph->tot_len) <= (iph->ihl + tcph->doff) * 4) {
> + return true;
> + }
It's rather ugly to use magic values (13 and 0x10) like that. Can't you
use some of the existing defines? At least I see TCP_FLAG_ACK and struct
tcphdr::ack being available, so you should even have choises what to
use.
--
Kalle Valo
