syncookies: do not store rcv_wscale in tcp timestamp

As pointed out by Fernando Gont there is no need to encode rcv_wscale
into the cookie.

We did not use the restored rcv_wscale anyway; it is recomputed
via tcp_select_initial_window().

Thus we can save 4 bits in the ts option space by removing rcv_wscale.
In case window scaling was not supported, we set the (invalid) wscale
value 0xf.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 1 deletions

diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index c7ee57421ece..84d818cfae17 100644
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -217,7 +217,6 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
         req->retrans = 0;
         ireq->ecn_ok            = 0;
         ireq->snd_wscale        = tcp_opt.snd_wscale;
-        ireq->rcv_wscale        = tcp_opt.rcv_wscale;
         ireq->sack_ok           = tcp_opt.sack_ok;
         ireq->wscale_ok         = tcp_opt.wscale_ok;
         ireq->tstamp_ok         = tcp_opt.saw_tstamp;