ipv4: Make rt->fl.iif tests lest obscure.

When we test rt->fl.iif against zero, we're seeing if it's
an output or an input route.

Make that explicit with some helper functions.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 96bc7f9475a3..c6e2affafbd3 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -506,8 +506,8 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
                 struct net_device *dev = NULL;
 
                 rcu_read_lock();
-                if (rt->fl.iif &&
-                        net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr)
+                if (rt_is_input_route(rt) &&
+                    net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr)
                         dev = dev_get_by_index_rcu(net, rt->fl.iif);
 
                 if (dev)