inetpeer: Mark metrics as "new" in fresh inetpeer entries.

Set the RTAX_LOCKED metric to INETPEER_METRICS_NEW (basically,
all ones) on fresh inetpeer entries.

This way code can determine if default metrics have been loaded
in from a routing table entry already.
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/inetpeer.h

@@ -51,6 +51,13 @@ struct inet_peer {
 
 void			inet_initpeers(void) __init;
 
+#define INETPEER_METRICS_NEW	(~(u32) 0)
+
+static inline bool inet_metrics_new(const struct inet_peer *p)
+{
+	return p->metrics[RTAX_LOCK-1] == INETPEER_METRICS_NEW;
+}
+
 /* can be called with or without local BH being disabled */
 struct inet_peer	*inet_getpeer(struct inetpeer_addr *daddr, int create);
 

net/ipv4/inetpeer.c

@@ -512,6 +512,7 @@ struct inet_peer *inet_getpeer(struct inetpeer_addr *daddr, int create)
 		atomic_set(&p->rid, 0);
 		atomic_set(&p->ip_id_count, secure_ip_id(daddr->a4));
 		p->tcp_ts_stamp = 0;
+		p->metrics[RTAX_LOCK-1] = INETPEER_METRICS_NEW;
 		INIT_LIST_HEAD(&p->unused);