public inbox for netdev@vger.kernel.org 
 help / color / mirror / Atom feed

From: Toshiaki Makita <makita.toshiaki@lab•ntt.co.jp>
To: Ding Tianhong <dingtianhong@huawei•com>,
	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, 05 Jun 2014 19:51:34 +0900	[thread overview]
Message-ID: <53904BB6.7030803@lab.ntt.co.jp> (raw)
In-Reply-To: <53903D5A.7050702@huawei.com>

(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.

Thanks,
Toshiaki Makita

next prev parent reply	other threads:[~2014-06-05 10:51 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 [this message]
2014-06-05 11:42         ` Ding Tianhong
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=53904BB6.7030803@lab.ntt.co.jp \
    --to=makita.toshiaki@lab$(echo .)ntt.co.jp \
    --cc=davem@davemloft$(echo .)net \
    --cc=dingtianhong@huawei$(echo .)com \
    --cc=edumazet@google$(echo .)com \
    --cc=kaber@trash$(echo .)net \
    --cc=netdev@vger$(echo .)kernel.org \
    --cc=vyasevic@redhat$(echo .)com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox