path: root/net/core/neighbour.c
diff options
authorDavid Ahern <dsahern@gmail.com>2019-05-01 18:18:42 -0700
committerDavid S. Miller <davem@davemloft.net>2019-05-04 00:38:53 -0400
commit4b2a2bfeb3f056461a90bd621e8bd7d03fa47f60 (patch)
treebea0822c13d5c2845b82d8923dfcb1fe2f58d887 /net/core/neighbour.c
parentneighbor: Reset gc_entries counter if new entry is released before insert (diff)
neighbor: Call __ipv4_neigh_lookup_noref in neigh_xmit
Commit cd9ff4de0107 changed the key for IFF_POINTOPOINT devices to INADDR_ANY but neigh_xmit which is used for MPLS encapsulations was not updated to use the altered key. The result is that every packet Tx does a lookup on the gateway address which does not find an entry, a new one is created only to find the existing one in the table right before the insert since arp_constructor was updated to reset the primary key. This is seen in the allocs and destroys counters: ip -s -4 ntable show | head -10 | grep alloc which increase for each packet showing the unnecessary overhread. Fix by having neigh_xmit use __ipv4_neigh_lookup_noref for NEIGH_ARP_TABLE. Fixes: cd9ff4de0107 ("ipv4: Make neigh lookup keys for loopback/point-to-point devices be INADDR_ANY") Reported-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: David Ahern <dsahern@gmail.com> Tested-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/neighbour.c')
1 files changed, 8 insertions, 1 deletions
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index aff051e5521d..9b9da5142613 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -31,6 +31,7 @@
#include <linux/times.h>
#include <net/net_namespace.h>
#include <net/neighbour.h>
+#include <net/arp.h>
#include <net/dst.h>
#include <net/sock.h>
#include <net/netevent.h>
@@ -2984,7 +2985,13 @@ int neigh_xmit(int index, struct net_device *dev,
if (!tbl)
goto out;
- neigh = __neigh_lookup_noref(tbl, addr, dev);
+ if (index == NEIGH_ARP_TABLE) {
+ u32 key = *((u32 *)addr);
+ neigh = __ipv4_neigh_lookup_noref(dev, key);
+ } else {
+ neigh = __neigh_lookup_noref(tbl, addr, dev);
+ }
if (!neigh)
neigh = __neigh_create(tbl, addr, dev, false);
err = PTR_ERR(neigh);