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Diffstat (limited to 'net/ipv6/syncookies.c')
-rw-r--r--net/ipv6/syncookies.c20
1 files changed, 16 insertions, 4 deletions
diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index 3a622e7abc02..938ce4ecde55 100644
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -170,6 +170,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
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 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
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 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
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 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
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;