Merge branch 'nfsd-next' of git://linux-nfs.org/~bfields/linux

[~andy/linux] / include / net / tcp.h

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 8c4dd63134d498164dee2c60978fccb3568e5b57..743accec6c76e056547102a0b429418b8450af65 100644 (file)
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -480,20 +480,21 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
 #ifdef CONFIG_SYN_COOKIES
 #include <linux/ktime.h>
 
-/* Syncookies use a monotonic timer which increments every 64 seconds.
+/* Syncookies use a monotonic timer which increments every 60 seconds.
  * This counter is used both as a hash input and partially encoded into
  * the cookie value.  A cookie is only validated further if the delta
  * between the current counter value and the encoded one is less than this,
- * i.e. a sent cookie is valid only at most for 128 seconds (or less if
+ * i.e. a sent cookie is valid only at most for 2*60 seconds (or less if
  * the counter advances immediately after a cookie is generated).
  */
 #define MAX_SYNCOOKIE_AGE 2
 
 static inline u32 tcp_cookie_time(void)
 {
-       struct timespec now;
-       getnstimeofday(&now);
-       return now.tv_sec >> 6; /* 64 seconds granularity */
+       u64 val = get_jiffies_64();
+
+       do_div(val, 60 * HZ);
+       return val;
 }
 
 u32 __cookie_v4_init_sequence(const struct iphdr *iph, const struct tcphdr *th,