From: Ding Tianhong <dingtianhong@huawei•com>
To: Toshiaki Makita <makita.toshiaki@lab•ntt.co.jp>,
<kaber@trash•net>, <davem@davemloft•net>, <edumazet@google•com>,
<vyasevic@redhat•com>
Cc: <netdev@vger•kernel.org>
Subject: Re: [PATCH net-next 2/4] net: dev: don't set the same mac address for netdev
Date: Thu, 5 Jun 2014 19:42:09 +0800 [thread overview]
Message-ID: <53905791.4060401@huawei.com> (raw)
In-Reply-To: <53904BB6.7030803@lab.ntt.co.jp>
On 2014/6/5 18:51, Toshiaki Makita wrote:
> (2014/06/05 18:50), Ding Tianhong wrote:
>> On 2014/6/5 17:09, Toshiaki Makita wrote:
>>> (2014/06/05 15:50), Ding Tianhong wrote:
>>>> Most of netdev just like bond, team, vlan will set the mac address
>>>> and propagate to the upperdev or lowerdev regardless the mac address
>>>> is same or not, I could not find that the same mac address could
>>>> make affect, so add equal check when set mac address.
>>>>
>>>> Signed-off-by: Ding Tianhong <dingtianhong@huawei•com>
>>>> ---
>>>> net/core/dev.c | 2 ++
>>>> 1 file changed, 2 insertions(+)
>>>>
>>>> diff --git a/net/core/dev.c b/net/core/dev.c
>>>> index 5367bfb..4008a51 100644
>>>> --- a/net/core/dev.c
>>>> +++ b/net/core/dev.c
>>>> @@ -5570,6 +5570,8 @@ int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
>>>> return -EINVAL;
>>>> if (!netif_device_present(dev))
>>>> return -ENODEV;
>>>> + if (ether_addr_equal_64bits(dev->dev_addr, sa->sa_data))
>>>> + return 0;
>>>> err = ops->ndo_set_mac_address(dev, sa);
>>>> if (err)
>>>> return err;
>>>>
>>>
>>> Bridge uses addr_assign_type to check if bridge_id can be propageted by
>>> bridge ports. If user set mac address, and even if it is the same as
>>> current one, bridge uses the fact that the mac address is set by user.
>>>
>>
>> OK
>>
>>> Although I'm not aware of a driver that needs calling of
>>> ndo_set_mac_address() for the same mac address, this change looks a bit
>>> risky to me.
>>> (For example, old bridge code needed this call because it managed
>>> BR_SET_MAC_ADDR in bridge flags.)
>>>
>> Except the old bridge, I still don't think any other driver need to call ndo_set_mac_address()
>> for the same mac address, if the dev_set_mac_address() don't do anything for the same address,
>> I think some drivers should ignore the same mac address themselves just like bonding, macvlan, vlan and so on.
>
> Though I don't know why you think this is safe, looking over some
> drivers, br2684_mac_addr() seems to use a logic similar to old bridge's.
>
Hm, I miss that, this improvement is risky for some drivers, I will remove this patch
and resend the series later. thanks.
Ding
> Thanks,
> Toshiaki Makita
>
> .
>
next prev parent reply other threads:[~2014-06-05 11:42 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-05 6:50 [PATCH net-next 0/4] macvlan: fix some problem if mac address changes Ding Tianhong
2014-06-05 6:50 ` [PATCH net-next 1/4] macvlan: don't update the uc and vlan list for L2 forwarding offload Ding Tianhong
2014-06-05 13:52 ` Vlad Yasevich
2014-06-05 14:12 ` John Fastabend
2014-06-05 6:50 ` [PATCH net-next 2/4] net: dev: don't set the same mac address for netdev Ding Tianhong
2014-06-05 9:09 ` Toshiaki Makita
2014-06-05 9:50 ` Ding Tianhong
2014-06-05 10:51 ` Toshiaki Makita
2014-06-05 11:42 ` Ding Tianhong [this message]
2014-06-05 14:06 ` Vlad Yasevich
2014-06-06 3:54 ` Ding Tianhong
2014-06-06 14:09 ` Vlad Yasevich
2014-06-07 5:53 ` Ding Tianhong
2014-06-05 6:50 ` [PATCH net-next 3/4] net: dev: revert the mac address when notifier failed Ding Tianhong
2014-06-05 6:50 ` [PATCH net-next 4/4] macvlan: don't set the same mac address for non-passthru mode Ding Tianhong
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