---

yaml
---
r: 202969
b: refs/heads/master
c: 8c76368
h: refs/heads/master
i:
  202967: cc16e17
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 317fe0e6c5dc9448bcef41a2e31fecfd3dba7f55
+refs/heads/master: 8c76368174ed2359739f1b7b8a9c042b1ef839c4

trunk/include/net/tcp.h

@@ -464,7 +464,7 @@ extern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb,
 				     __u16 *mss);
 
 extern __u32 cookie_init_timestamp(struct request_sock *req);
-extern void cookie_check_timestamp(struct tcp_options_received *tcp_opt);
+extern bool cookie_check_timestamp(struct tcp_options_received *tcp_opt);
 
 /* From net/ipv6/syncookies.c */
 extern struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb);

trunk/net/ipv4/syncookies.c

@@ -230,23 +230,36 @@ static inline struct sock *get_cookie_sock(struct sock *sk, struct sk_buff *skb,
  * The lowest 4 bits are for snd_wscale
  * The next 4 lsb are for rcv_wscale
  * The next lsb is for sack_ok
+ *
+ * return false if we decode an option that should not be.
  */
-void cookie_check_timestamp(struct tcp_options_received *tcp_opt)
+bool cookie_check_timestamp(struct tcp_options_received *tcp_opt)
 {
 	/* echoed timestamp, 9 lowest bits contain options */
 	u32 options = tcp_opt->rcv_tsecr & TSMASK;
 
+	if (!tcp_opt->saw_tstamp)  {
+		tcp_clear_options(tcp_opt);
+		return true;
+	}
+
+	if (!sysctl_tcp_timestamps)
+		return false;
+
 	tcp_opt->snd_wscale = options & 0xf;
 	options >>= 4;
 	tcp_opt->rcv_wscale = options & 0xf;
 
 	tcp_opt->sack_ok = (options >> 4) & 0x1;
 
-	if (tcp_opt->sack_ok)
-		tcp_sack_reset(tcp_opt);
+	if (tcp_opt->sack_ok && !sysctl_tcp_sack)
+		return false;
 
-	if (tcp_opt->snd_wscale || tcp_opt->rcv_wscale)
+	if (tcp_opt->snd_wscale || tcp_opt->rcv_wscale) {
 		tcp_opt->wscale_ok = 1;
+		return sysctl_tcp_window_scaling != 0;
+	}
+	return true;
 }
 EXPORT_SYMBOL(cookie_check_timestamp);
 
@@ -281,8 +294,8 @@ struct sock *cookie_v4_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 (tcp_opt.saw_tstamp)
-		cookie_check_timestamp(&tcp_opt);
+	if (!cookie_check_timestamp(&tcp_opt))
+		goto out;
 
 	ret = NULL;
 	req = inet_reqsk_alloc(&tcp_request_sock_ops); /* for safety */

trunk/net/ipv6/syncookies.c

@@ -180,8 +180,8 @@ 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 (tcp_opt.saw_tstamp)
-		cookie_check_timestamp(&tcp_opt);
+	if (!cookie_check_timestamp(&tcp_opt))
+		goto out;
 
 	ret = NULL;
 	req = inet6_reqsk_alloc(&tcp6_request_sock_ops);