ipv4: Make neigh lookup keys for loopback/point-to-point devices be INADDR_ANY
[ Upstream commit cd9ff4de0107c65d69d02253bb25d6db93c3dbc1 ]
Map all lookup neigh keys to INADDR_ANY for loopback/point-to-point devices
to avoid making an entry for every remote ip the device needs to talk to.
This used the be the old behavior but became broken in a263b3093641f
(ipv4: Make neigh lookups directly in output packet path) and later removed
in 0bb4087cbec0 (ipv4: Fix neigh lookup keying over loopback/point-to-point
devices) because it was broken.
Signed-off-by: Jim Westfall <jwestfall@surrealistic.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/net/arp.h b/include/net/arp.h
index 5e0f891..1b3f869 100644
--- a/include/net/arp.h
+++ b/include/net/arp.h
@@ -19,6 +19,9 @@
static inline struct neighbour *__ipv4_neigh_lookup_noref(struct net_device *dev, u32 key)
{
+ if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))
+ key = INADDR_ANY;
+
return ___neigh_lookup_noref(&arp_tbl, neigh_key_eq32, arp_hashfn, &key, dev);
}