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>
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 2e41e6f..8fa32f5 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1328,14 +1328,12 @@
if (security_inet_conn_request(sk, skb, req))
goto drop_and_free;
- if (!want_cookie)
+ if (!want_cookie || tmp_opt.tstamp_ok)
TCP_ECN_create_request(req, tcp_hdr(skb));
if (want_cookie) {
-#ifdef CONFIG_SYN_COOKIES
- req->cookie_ts = tmp_opt.tstamp_ok;
-#endif
isn = cookie_v4_init_sequence(sk, skb, &req->mss);
+ req->cookie_ts = tmp_opt.tstamp_ok;
} else if (!isn) {
struct inet_peer *peer = NULL;