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| author | Sowmini Varadhan <sowmini.varadhan@oracle.com> | 2017-06-02 09:01:49 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-06-04 21:37:18 -0400 |
| commit | 5071034e4af709d6783b7d105dc296a5cc84739b (patch) | |
| tree | 1817b75dea97eee82647e69c498c35c4d886ece3 /include | |
| parent | 030a89028db07a7987f1f3bd6ee43114e36f5060 (diff) | |
| download | linux-5071034e4af709d6783b7d105dc296a5cc84739b.tar.bz2 | |
neigh: Really delete an arp/neigh entry on "ip neigh delete" or "arp -d"
The command
# arp -s 62.2.0.1 a:b:c:d:e:f dev eth2
adds an entry like the following (listed by "arp -an")
? (62.2.0.1) at 0a:0b:0c:0d:0e:0f [ether] PERM on eth2
but the symmetric deletion command
# arp -i eth2 -d 62.2.0.1
does not remove the PERM entry from the table, and instead leaves behind
? (62.2.0.1) at <incomplete> on eth2
The reason is that there is a refcnt of 1 for the arp_tbl itself
(neigh_alloc starts off the entry with a refcnt of 1), thus
the neigh_release() call from arp_invalidate() will (at best) just
decrement the ref to 1, but will never actually free it from the
table.
To fix this, we need to do something like neigh_forced_gc: if
the refcnt is 1 (i.e., on the table's ref), remove the entry from
the table and free it. This patch refactors and shares common code
between neigh_forced_gc and the newly added neigh_remove_one.
A similar issue exists for IPv6 Neighbor Cache entries, and is fixed
in a similar manner by this patch.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/neighbour.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/net/neighbour.h b/include/net/neighbour.h index e4dd3a214034..639b67564a7d 100644 --- a/include/net/neighbour.h +++ b/include/net/neighbour.h @@ -317,6 +317,7 @@ int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb); int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags, u32 nlmsg_pid); void __neigh_set_probe_once(struct neighbour *neigh); +bool neigh_remove_one(struct neighbour *ndel, struct neigh_table *tbl); void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev); int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev); int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb); |