[PATCH net-next] rtnetlink: skip metrics loop for dst_default_metrics

[David Ahern]

From: David Ahern <dsah...@gmail.com>

dst_default_metrics has all of the metrics initialized to 0, so nothing
will be added to the skb in rtnetlink_put_metrics. Avoid the loop if
metrics is from dst_default_metrics.

Signed-off-by: David Ahern <dsah...@gmail.com>
---
 net/core/rtnetlink.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 8ac81630ab5c..1ee6460f8275 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -751,6 +751,10 @@ int rtnetlink_put_metrics(struct sk_buff *skb, u32 
*metrics)
        struct nlattr *mx;
        int i, valid = 0;
 
+       /* nothing is dumped for dst_default_metrics, so just skip the loop */
+       if (metrics == dst_default_metrics.metrics)
+               return 0;
+
        mx = nla_nest_start_noflag(skb, RTA_METRICS);
        if (mx == NULL)
                return -ENOBUFS;
-- 
2.11.0