diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index 3a622e7..938ce4e 100644
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -170,6 +170,7 @@
 	int mss;
 	struct dst_entry *dst;
 	__u8 rcv_wscale;
+	struct tcp_options_received tcp_opt;
 
 	if (!sysctl_tcp_syncookies || !th->ack)
 		goto out;
@@ -182,6 +183,13 @@
 
 	NET_INC_STATS_BH(LINUX_MIB_SYNCOOKIESRECV);
 
+	/* check for timestamp cookie support */
+	memset(&tcp_opt, 0, sizeof(tcp_opt));
+	tcp_parse_options(skb, &tcp_opt, 0);
+
+	if (tcp_opt.saw_tstamp)
+		cookie_check_timestamp(&tcp_opt);
+
 	ret = NULL;
 	req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
 	if (!req)
@@ -216,8 +224,12 @@
 
 	req->expires = 0UL;
 	req->retrans = 0;
-	ireq->snd_wscale = ireq->rcv_wscale = ireq->tstamp_ok = 0;
-	ireq->wscale_ok = ireq->sack_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;
+	req->ts_recent		= tcp_opt.saw_tstamp ? tcp_opt.rcv_tsval : 0;
 	treq->rcv_isn = ntohl(th->seq) - 1;
 	treq->snt_isn = cookie;
 
@@ -253,10 +265,10 @@
 			goto out;
 	}
 
-	req->window_clamp = dst_metric(dst, RTAX_WINDOW);
+	req->window_clamp = tp->window_clamp ? :dst_metric(dst, RTAX_WINDOW);
 	tcp_select_initial_window(tcp_full_space(sk), req->mss,
 				  &req->rcv_wnd, &req->window_clamp,
-				  0, &rcv_wscale);
+				  ireq->wscale_ok, &rcv_wscale);
 
 	ireq->rcv_wscale = rcv_wscale;