From: Patrick McHardy <kaber@trash•net>
To: "Timo Teräs" <timo.teras@iki•fi>
Cc: netdev@vger•kernel.org
Subject: Re: [PATCH 2/2] ipv4: flush ARP entries on device change
Date: Wed, 03 Mar 2010 15:33:59 +0100 [thread overview]
Message-ID: <4B8E7357.5050203@trash.net> (raw)
In-Reply-To: <4B8E701D.7070300@iki.fi>
Timo Teräs wrote:
> Patrick McHardy wrote:
>> Timo Teras wrote:
>>> If device flag IFF_NOARP is changed, we should flush the ARP cache as
>>> all
>>> entries need to get refreshed.
>>>
>>> Signed-off-by: Timo Teras <timo.teras@iki•fi>
>>> ---
>>> net/ipv4/arp.c | 3 +++
>>> 1 files changed, 3 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
>>> index c4dd135..036da92 100644
>>> --- a/net/ipv4/arp.c
>>> +++ b/net/ipv4/arp.c
>>> @@ -1245,6 +1245,9 @@ static int arp_netdev_event(struct
>>> notifier_block *this, unsigned long event, vo
>>> neigh_changeaddr(&arp_tbl, dev);
>>> rt_cache_flush(dev_net(dev), 0);
>>> break;
>>> + case NETDEV_CHANGE:
>>> + neigh_changeaddr(&arp_tbl, dev);
>>> + break;
>>
>> It would be nice if we could restrict this to IFF_NOARP changes.
>
> Yes. But I did not see any easy way to figure out which flags have changed.
>
> Should we just keep a copy of the previous IFF_NOARP bit somewhere
> (where?).
> Or did I miss something obvious?
We shouldn't have any arp entries for devices with IFF_NOARP set,
so perhaps we can flush only in that case. The transition IFF_NOARP
-> ~IFF_NOARP shouldn't need flushing.
next prev parent reply other threads:[~2010-03-03 14:34 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-03 14:01 [PATCH 1/2] gre: fix hard header destination address checking Timo Teras
2010-03-03 14:01 ` [PATCH 2/2] ipv4: flush ARP entries on device change Timo Teras
2010-03-03 14:06 ` Patrick McHardy
2010-03-03 14:20 ` Timo Teräs
2010-03-03 14:33 ` Patrick McHardy [this message]
2010-03-03 14:39 ` Timo Teräs
2010-03-03 14:44 ` Patrick McHardy
2010-03-04 11:15 ` Timo Teräs
2010-03-04 8:41 ` [PATCH 1/2] gre: fix hard header destination address checking David Miller
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