net: rtnetlink: Don't export empty RTAX_FEATURES

Since the features bit field has bits for internal only use as well, it
may happen that the kernel exports RTAX_FEATURES attribute with zero
value which is pointless.

Fix this by making sure the attribute is added only if the exported
value is non-zero.

Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Phil Sutter 2016-08-23 13:14:31 +02:00 committed by David S. Miller
parent e7b48a32dc
commit f8edcd127b
1 changed files with 2 additions and 0 deletions

View File

@ -704,6 +704,8 @@ int rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics)
} else if (i == RTAX_FEATURES - 1) {
u32 user_features = metrics[i] & RTAX_FEATURE_MASK;
if (!user_features)
continue;
BUILD_BUG_ON(RTAX_FEATURE_MASK & DST_FEATURE_MASK);
if (nla_put_u32(skb, i + 1, user_features))
goto nla_put_failure;