ipv4: Move IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN to helper

in_dev lookup followed by IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN check
is called in several places, some with the rcu lock and others with the
rtnl held.

Move the check to a helper similar to what IPv6 has. Since the helper
can be invoked from either context use rcu_dereference_rtnl to
dereference ip_ptr.

Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 14 insertions, 0 deletions

diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index a64f21a97369..367dc2a0f84a 100644
--- a/include/linux/inetdevice.h
+++ b/include/linux/inetdevice.h
@@ -237,6 +237,20 @@ static inline struct in_device *__in_dev_get_rtnl(const struct net_device *dev)
 	return rtnl_dereference(dev->ip_ptr);
 }
 
+/* called with rcu_read_lock or rtnl held */
+static inline bool ip_ignore_linkdown(const struct net_device *dev)
+{
+	struct in_device *in_dev;
+	bool rc = false;
+
+	in_dev = rcu_dereference_rtnl(dev->ip_ptr);
+	if (in_dev &&
+	    IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev))
+		rc = true;
+
+	return rc;
+}
+
 static inline struct neigh_parms *__in_dev_arp_parms_get_rcu(const struct net_device *dev)
 {
 	struct in_device *in_dev = __in_dev_get_rcu(dev);