From 260eb694b5a4bd3424a7c445128fb5a784e95e3d Mon Sep 17 00:00:00 2001 From: Jim Westfall Date: Sun, 14 Jan 2018 04:18:51 -0800 Subject: 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 Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/arp.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'net') diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c index 51b27ae09fbd..e60517eb1c3a 100644 --- a/net/ipv4/arp.c +++ b/net/ipv4/arp.c @@ -223,11 +223,16 @@ static bool arp_key_eq(const struct neighbour *neigh, const void *pkey) static int arp_constructor(struct neighbour *neigh) { - __be32 addr = *(__be32 *)neigh->primary_key; + __be32 addr; struct net_device *dev = neigh->dev; struct in_device *in_dev; struct neigh_parms *parms; + u32 inaddr_any = INADDR_ANY; + if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) + memcpy(neigh->primary_key, &inaddr_any, arp_tbl.key_len); + + addr = *(__be32 *)neigh->primary_key; rcu_read_lock(); in_dev = __in_dev_get_rcu(dev); if (!in_dev) { -- cgit v1.2.3