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| author | David Ahern <dsahern@gmail.com> | 2019-05-01 18:18:42 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-05-04 00:38:53 -0400 |
| commit | 4b2a2bfeb3f056461a90bd621e8bd7d03fa47f60 (patch) | |
| tree | bea0822c13d5c2845b82d8923dfcb1fe2f58d887 | |
| parent | 64c6f4bbca748c3b2101469a76d88b7cd1c00476 (diff) | |
| download | linux-4b2a2bfeb3f056461a90bd621e8bd7d03fa47f60.tar.gz linux-4b2a2bfeb3f056461a90bd621e8bd7d03fa47f60.tar.bz2 linux-4b2a2bfeb3f056461a90bd621e8bd7d03fa47f60.zip | |
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>
| -rw-r--r-- | net/core/neighbour.c | 9 |
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; rcu_read_lock_bh(); - 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); |