On Sat, 29 Jan 2022, Florian Westphal wrote:
> It seems more readable to use a common helper in the followup fix rather
> than copypaste or goto.
>
> No functional change intended. The function is only called for syn-ack
> or syn in repy direction in case of simultaneous open.
>
> Cc: Jozsef Kadlecsik <kadlec@xxxxxxxxxxxxx>
> Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Acked-by: Jozsef Kadlecsik <kadlec@xxxxxxxxxxxxx>
> ---
> net/netfilter/nf_conntrack_proto_tcp.c | 47 ++++++++++++++++----------
> 1 file changed, 29 insertions(+), 18 deletions(-)
>
> diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
> index af5115e127cf..88c89e97d8a2 100644
> --- a/net/netfilter/nf_conntrack_proto_tcp.c
> +++ b/net/netfilter/nf_conntrack_proto_tcp.c
> @@ -446,6 +446,32 @@ static void tcp_sack(const struct sk_buff *skb, unsigned int dataoff,
> }
> }
>
> +static void tcp_init_sender(struct ip_ct_tcp_state *sender,
> + struct ip_ct_tcp_state *receiver,
> + const struct sk_buff *skb,
> + unsigned int dataoff,
> + const struct tcphdr *tcph,
> + u32 end, u32 win)
> +{
> + /* SYN-ACK in reply to a SYN
> + * or SYN from reply direction in simultaneous open.
> + */
> + sender->td_end =
> + sender->td_maxend = end;
> + sender->td_maxwin = (win == 0 ? 1 : win);
> +
> + tcp_options(skb, dataoff, tcph, sender);
> + /* RFC 1323:
> + * Both sides must send the Window Scale option
> + * to enable window scaling in either direction.
> + */
> + if (!(sender->flags & IP_CT_TCP_FLAG_WINDOW_SCALE &&
> + receiver->flags & IP_CT_TCP_FLAG_WINDOW_SCALE)) {
> + sender->td_scale = 0;
> + receiver->td_scale = 0;
> + }
> +}
> +
> static bool tcp_in_window(struct nf_conn *ct,
> enum ip_conntrack_dir dir,
> unsigned int index,
> @@ -499,24 +525,9 @@ static bool tcp_in_window(struct nf_conn *ct,
> * Initialize sender data.
> */
> if (tcph->syn) {
> - /*
> - * SYN-ACK in reply to a SYN
> - * or SYN from reply direction in simultaneous open.
> - */
> - sender->td_end =
> - sender->td_maxend = end;
> - sender->td_maxwin = (win == 0 ? 1 : win);
> -
> - tcp_options(skb, dataoff, tcph, sender);
> - /*
> - * RFC 1323:
> - * Both sides must send the Window Scale option
> - * to enable window scaling in either direction.
> - */
> - if (!(sender->flags & IP_CT_TCP_FLAG_WINDOW_SCALE
> - && receiver->flags & IP_CT_TCP_FLAG_WINDOW_SCALE))
> - sender->td_scale =
> - receiver->td_scale = 0;
> + tcp_init_sender(sender, receiver,
> + skb, dataoff, tcph,
> + end, win);
> if (!tcph->ack)
> /* Simultaneous open */
> return true;
> --
> 2.34.1
>
>
-
E-mail : kadlec@xxxxxxxxxxxxxxxxx, kadlecsik.jozsef@xxxxxxxxx
PGP key : https://wigner.hu/~kadlec/pgp_public_key.txt
Address : Wigner Research Centre for Physics
H-1525 Budapest 114, POB. 49, Hungary
