Date:	Mon, 9 Mar 2015 16:23:47 -0700
From:	Roopa Prabhu <roopa@...ulusnetworks.com>
To:	"Arad, Ronen" <ronen.arad@...el.com>
Cc:	Jiri Pirko <jiri@...nulli.us>, Scott Feldman <sfeldma@...il.com>,
	Netdev <netdev@...r.kernel.org>,
	"David S. Miller" <davem@...emloft.net>
Subject: Re: [PATCH net-next] rocker: check for BRIDGE_FLAGS_SELF in bridge
 setlink handler

sorry, this email might have gone with non-text (though i selected
'plain text' in my google mail web client). Retrying...apologize for
multiple emails.

On Mon, Mar 9, 2015 at 3:56 PM, Roopa Prabhu <roopa@...ulusnetworks.com> wrote:
>
>
> On Mon, Mar 9, 2015 at 8:59 AM, Arad, Ronen <ronen.arad@...el.com> wrote:
>>
>>
>>
>> >-----Original Message-----
>> >From: netdev-owner@...r.kernel.org [mailto:netdev-owner@...r.kernel.org]
>> > On
>> >Behalf Of Jiri Pirko
>> >
>> >
>>
>> >I also think that is is fine that in case either master or self are not
>> > set,
>> >driver ndo setlink is called as well (in case the offload bit is on). It
>> >makes it transparent for user in case he does not care what in under. In
>> >case he cares, he can specify master or self to achieve exactly what he
>> >needs. I like it that way.
>> >
>> >
>> It would be nice to have switch driver implementation that could work
>> Consistently with and without the bridge driver. I expect use case where a
>> bridge is only used when L3 is needed or to leverage L2 protocols that are
>> implemented by the bridge driver (e.g. STP, IGMP snooping).
>
>
>>
>> If my driver can process setlink requests using SELF flag today, I'd like
>> it
>> to work the same when setlink is propagated down from a bridge master or
>> from a team/bond master.
>
>
>>
>>
>> There is current issue with notification.
>> When SELF flag is set, the bridge driver does not offload to the port
>> driver
>> and notification is issued by rtnetlink.c by calling the port getlink ndo.
>
>
>
>>
>> This call, however, is done with zero filter_mask such that VLAN
>> information
>> is not included in the notification.
>
>
>
>>
>> When SELF flag is not set, bridge driver offloads to the port and issues
>> the
>> notification. In that case it sets the filter to VLAN_COMPRESSED.
>> I don't see how I can get my driver to behave consistently with and
>> without
>> a bridge.
>> The closest I can get notification with and without a bridge is for the
>> driver to examine the flags. If SELF is set, the driver knows it got
>> invoked
>> directly from rtnetlink and it should notify VLAN setting as the
>> subsequent
>> notification triggered by rtnetlink won't.
>> When the switch driver does not see SELF set it knows that it was invoked
>> by
>> The bridge driver which already takes care of notification including VLAN
>> information.
>>
>
> You are right about self being handled from rtnetlink.c and the notification
> triggered from rtnetlink.c
> can be different from the one sent from the bridge driver.
> In the specific case of vlan information not being present in the self
> notifications generated from rtnetlink.c, that is
> something that will need to be fixed eventually.
> Since rtnetlink.c generates these notifications and not the port driver,
> like you say, port driver could generate the appropriate notification or
> rtnetlink.c will have to get the size of the skb from the port driver before
> doing a bridge_getlink call into the port driver.
>
> This is another good example, where the port driver might need to look at
> the self flag after-all.
>
> Thanks,
> Roopa
>
>
>
>
>
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