syncookies: add support for ECN

Allows use of ECN when syncookies are in effect by encoding ecn_ok
into the syn-ack tcp timestamp.

While at it, remove a uneeded #ifdef CONFIG_SYN_COOKIES.
With CONFIG_SYN_COOKIES=nm want_cookie is ifdef'd to 0 and gcc
removes the "if (0)".

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Florian Westphal
2010-06-21 11:48:45 +00:00
committed by David S. Miller
parent 734f614bc1
commit 172d69e63c
5 changed files with 17 additions and 13 deletions

View File

@@ -164,6 +164,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
int mss;
struct dst_entry *dst;
__u8 rcv_wscale;
bool ecn_ok;
if (!sysctl_tcp_syncookies || !th->ack || th->rst)
goto out;
@@ -180,7 +181,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
memset(&tcp_opt, 0, sizeof(tcp_opt));
tcp_parse_options(skb, &tcp_opt, &hash_location, 0);
if (!cookie_check_timestamp(&tcp_opt))
if (!cookie_check_timestamp(&tcp_opt, &ecn_ok))
goto out;
ret = NULL;
@@ -215,7 +216,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
req->expires = 0UL;
req->retrans = 0;
ireq->ecn_ok = 0;
ireq->ecn_ok = ecn_ok;
ireq->snd_wscale = tcp_opt.snd_wscale;
ireq->sack_ok = tcp_opt.sack_ok;
ireq->wscale_ok = tcp_opt.wscale_ok;