syncookies: fix inclusion of tcp options in syn-ack

[ Upstream commit 8b5f12d04b2e93842f3dda01f029842047bf3f81 ]

David Miller noticed that commit
33ad798c924b4a1afad3593f2796d465040aadd5 '(tcp: options clean up')
did not move the req->cookie_ts check.
This essentially disabled commit 4dfc2817025965a2fc78a18c50f540736a6b5c24
'[Syncookies]: Add support for TCP options via timestamps.'.

This restores the original logic.

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

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 8165f5aa8c71b68f5d01dee2abb8dad5c7449c44..3acf812eed1027198611c4904a8c6dafa4b74549 100644 (file)
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2266,6 +2266,11 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
        }
 
        memset(&opts, 0, sizeof(opts));
+#ifdef CONFIG_SYN_COOKIES
+       if (unlikely(req->cookie_ts))
+               TCP_SKB_CB(skb)->when = cookie_init_timestamp(req);
+       else
+#endif
        TCP_SKB_CB(skb)->when = tcp_time_stamp;
        tcp_header_size = tcp_synack_options(sk, req,
                                             dst_metric(dst, RTAX_ADVMSS),
@@ -2292,11 +2297,6 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 
        /* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */
        th->window = htons(min(req->rcv_wnd, 65535U));
-#ifdef CONFIG_SYN_COOKIES
-       if (unlikely(req->cookie_ts))
-               TCP_SKB_CB(skb)->when = cookie_init_timestamp(req);
-       else
-#endif
        tcp_options_write((__be32 *)(th + 1), tp, &opts, &md5_hash_location);
        th->doff = (tcp_header_size >> 2);
        TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTSEGS);