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| author | David Ahern <dsahern@gmail.com> | 2019-05-02 04:18:42 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-06-11 13:22:46 +0300 |
| commit | 86e00b7405c7592c767938d7f50f28a9a20942c2 (patch) | |
| tree | 187252c1f52c463c4350ea5e18858057192da836 /net/core/neighbour.c | |
| parent | 66b835ecd281b776ccaeec57c25fbafc7cf2c5c2 (diff) | |
| download | linux-86e00b7405c7592c767938d7f50f28a9a20942c2.tar.xz | |
neighbor: Call __ipv4_neigh_lookup_noref in neigh_xmit
[ Upstream commit 4b2a2bfeb3f056461a90bd621e8bd7d03fa47f60 ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/core/neighbour.c')
| -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 8eb1916b742c..428dd614a18a 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -30,6 +30,7 @@ #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> @@ -2489,7 +2490,13 @@ 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); |