Cannot move macvlan interface on top of bonding device

Cannot move macvlan interface on top of bonding device

[Francesco Ruggeri]

I cannot move a macvlan interface created on top of a bonding interface
to a different namespace:

# ip netns add dummy0
# ip link add link bond0 mac0 type macvlan
# ip link set mac0 netns dummy0
RTNETLINK answers: Invalid argument
#

This used to work in older releases.
The problem seems to be that commit f939981492 sets NETIF_F_NETNS_LOCAL
on bonding interfaces, and commit 797f87f83 causes macvlan interfaces
to inherit its features from the lower device.

Is there a reason why NETIF_F_NETNS_LOCAL should be inherited from the
lower device
by macvlan interfaces?

Thanks,
Francesco Ruggeri

Re: Cannot move macvlan interface on top of bonding device

[Cong Wang]

On Wed, Sep 17, 2014 at 8:56 AM, Francesco Ruggeri <fruggeri@arista.com> wrote:
> This used to work in older releases.
> The problem seems to be that commit f939981492 sets NETIF_F_NETNS_LOCAL
> on bonding interfaces, and commit 797f87f83 causes macvlan interfaces
> to inherit its features from the lower device.
>
> Is there a reason why NETIF_F_NETNS_LOCAL should be inherited from the
> lower device
> by macvlan interfaces?

commit 797f87f83 looks wrong, it should not inherit NETIF_F_NETNS_LOCAL,
so just clear this flag. Please submit a patch.

Re: Cannot move macvlan interface on top of bonding device

[Florian Westphal]

Cong Wang <cwang@twopensource.com> wrote:
> On Wed, Sep 17, 2014 at 8:56 AM, Francesco Ruggeri <fruggeri@arista.com> wrote:
> > This used to work in older releases.
> > The problem seems to be that commit f939981492 sets NETIF_F_NETNS_LOCAL
> > on bonding interfaces, and commit 797f87f83 causes macvlan interfaces
> > to inherit its features from the lower device.
> >
> > Is there a reason why NETIF_F_NETNS_LOCAL should be inherited from the
> > lower device
> > by macvlan interfaces?
> 
> commit 797f87f83 looks wrong, it should not inherit NETIF_F_NETNS_LOCAL,
> so just clear this flag. Please submit a patch.

Under which conditions would NETIF_F_NETNS_LOCAL have to be inherited?
(i.e., why is it inheritable in the first place?)

Re: Cannot move macvlan interface on top of bonding device

[Cong Wang]

On Wed, Sep 17, 2014 at 12:06 PM, Florian Westphal <fw@strlen.de> wrote:
> Cong Wang <cwang@twopensource.com> wrote:
>> On Wed, Sep 17, 2014 at 8:56 AM, Francesco Ruggeri <fruggeri@arista.com> wrote:
>> > This used to work in older releases.
>> > The problem seems to be that commit f939981492 sets NETIF_F_NETNS_LOCAL
>> > on bonding interfaces, and commit 797f87f83 causes macvlan interfaces
>> > to inherit its features from the lower device.
>> >
>> > Is there a reason why NETIF_F_NETNS_LOCAL should be inherited from the
>> > lower device
>> > by macvlan interfaces?
>>
>> commit 797f87f83 looks wrong, it should not inherit NETIF_F_NETNS_LOCAL,
>> so just clear this flag. Please submit a patch.
>
> Under which conditions would NETIF_F_NETNS_LOCAL have to be inherited?
> (i.e., why is it inheritable in the first place?)

Huh? Kidding me?
Isn't the question for yourself the author of commit 797f87f83?

Re: Cannot move macvlan interface on top of bonding device

[Vlad Yasevich]

On 09/17/2014 03:06 PM, Florian Westphal wrote:
> Cong Wang <cwang@twopensource.com> wrote:
>> On Wed, Sep 17, 2014 at 8:56 AM, Francesco Ruggeri <fruggeri@arista.com> wrote:
>>> This used to work in older releases.
>>> The problem seems to be that commit f939981492 sets NETIF_F_NETNS_LOCAL
>>> on bonding interfaces, and commit 797f87f83 causes macvlan interfaces
>>> to inherit its features from the lower device.
>>>
>>> Is there a reason why NETIF_F_NETNS_LOCAL should be inherited from the
>>> lower device
>>> by macvlan interfaces?
>>
>> commit 797f87f83 looks wrong, it should not inherit NETIF_F_NETNS_LOCAL,
>> so just clear this flag. Please submit a patch.
> 
> Under which conditions would NETIF_F_NETNS_LOCAL have to be inherited?
> (i.e., why is it inheritable in the first place?)

macvlan code calls
        features = netdev_increment_features(vlan->lowerdev->features,
                                             features,
                                             mask);

where lowerdev->features contains the NETIF_F_NETNS_LOCAL bit.  That
bit is not set in features or in mask.  It is also not one of the ALL_FOR_ALL
bits so it's not turned off.

As an example, here are the values from a quit test I ran:

bond features = 0x400f3888
features = 0x3b5a09  (mask is the same).
incremented features = 0x41bf389

NETIF_F_NETNS_LOCAL is still on.

May be a better solution is:

        features = netdev_increment_features(vlan->lowerdev->features & MACVLAN_FEATURS,
                                             features,
                                             mask);

This way we start with only the feature MACVLAN is interested in.

-vlad

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Re: Cannot move macvlan interface on top of bonding device

[Cong Wang]

On Wed, Sep 17, 2014 at 1:39 PM, Vlad Yasevich <vyasevich@gmail.com> wrote:
> On 09/17/2014 03:06 PM, Florian Westphal wrote:
>> Cong Wang <cwang@twopensource.com> wrote:
>>> On Wed, Sep 17, 2014 at 8:56 AM, Francesco Ruggeri <fruggeri@arista.com> wrote:
>>>> This used to work in older releases.
>>>> The problem seems to be that commit f939981492 sets NETIF_F_NETNS_LOCAL
>>>> on bonding interfaces, and commit 797f87f83 causes macvlan interfaces
>>>> to inherit its features from the lower device.
>>>>
>>>> Is there a reason why NETIF_F_NETNS_LOCAL should be inherited from the
>>>> lower device
>>>> by macvlan interfaces?
>>>
>>> commit 797f87f83 looks wrong, it should not inherit NETIF_F_NETNS_LOCAL,
>>> so just clear this flag. Please submit a patch.
>>
>> Under which conditions would NETIF_F_NETNS_LOCAL have to be inherited?
>> (i.e., why is it inheritable in the first place?)
>
> macvlan code calls
>         features = netdev_increment_features(vlan->lowerdev->features,
>                                              features,
>                                              mask);
>
> where lowerdev->features contains the NETIF_F_NETNS_LOCAL bit.  That
> bit is not set in features or in mask.  It is also not one of the ALL_FOR_ALL
> bits so it's not turned off.
>
> As an example, here are the values from a quit test I ran:
>
> bond features = 0x400f3888
> features = 0x3b5a09  (mask is the same).
> incremented features = 0x41bf389
>
> NETIF_F_NETNS_LOCAL is still on.

I think the comment on netdev_increment_features() is clear:

 *      Computes a new feature set after adding a device with feature set
 *      @one to the master device with current feature set @all.  Will not
 *      enable anything that is off in @mask. Returns the new feature set.

And NETIF_F_NETNS_LOCAL is on in mask.

>
> May be a better solution is:
>
>         features = netdev_increment_features(vlan->lowerdev->features & MACVLAN_FEATURS,
>                                              features,
>                                              mask);
>
> This way we start with only the feature MACVLAN is interested in.
>

Or clear it in mask?

Re: Cannot move macvlan interface on top of bonding device

[Francesco Ruggeri]

>>
>> May be a better solution is:
>>
>>         features = netdev_increment_features(vlan->lowerdev->features & MACVLAN_FEATURS,
>>                                              features,
>>                                              mask);
>>
>> This way we start with only the feature MACVLAN is interested in.
>>
>
> Or clear it in mask?

Do you guys see a problem with the patch I submitted (net: allow
macvlans to move to net namespace)?

Francesco

Re: Cannot move macvlan interface on top of bonding device

[Vlad Yasevich]

On 09/17/2014 04:46 PM, Cong Wang wrote:
> On Wed, Sep 17, 2014 at 1:39 PM, Vlad Yasevich <vyasevich@gmail.com> wrote:
>> On 09/17/2014 03:06 PM, Florian Westphal wrote:
>>> Cong Wang <cwang@twopensource.com> wrote:
>>>> On Wed, Sep 17, 2014 at 8:56 AM, Francesco Ruggeri <fruggeri@arista.com> wrote:
>>>>> This used to work in older releases.
>>>>> The problem seems to be that commit f939981492 sets NETIF_F_NETNS_LOCAL
>>>>> on bonding interfaces, and commit 797f87f83 causes macvlan interfaces
>>>>> to inherit its features from the lower device.
>>>>>
>>>>> Is there a reason why NETIF_F_NETNS_LOCAL should be inherited from the
>>>>> lower device
>>>>> by macvlan interfaces?
>>>>
>>>> commit 797f87f83 looks wrong, it should not inherit NETIF_F_NETNS_LOCAL,
>>>> so just clear this flag. Please submit a patch.
>>>
>>> Under which conditions would NETIF_F_NETNS_LOCAL have to be inherited?
>>> (i.e., why is it inheritable in the first place?)
>>
>> macvlan code calls
>>         features = netdev_increment_features(vlan->lowerdev->features,
>>                                              features,
>>                                              mask);
>>
>> where lowerdev->features contains the NETIF_F_NETNS_LOCAL bit.  That
>> bit is not set in features or in mask.  It is also not one of the ALL_FOR_ALL
>> bits so it's not turned off.
>>
>> As an example, here are the values from a quit test I ran:
>>
>> bond features = 0x400f3888
>> features = 0x3b5a09  (mask is the same).
>> incremented features = 0x41bf389
>>
>> NETIF_F_NETNS_LOCAL is still on.
> 

No, it is not.  NETIF_F_NETNS_LOCAL is bit 13 and that's off.  Bits
14 (GRO) and 12 (LLTX) are set.

-vlad

> I think the comment on netdev_increment_features() is clear:
> 
>  *      Computes a new feature set after adding a device with feature set
>  *      @one to the master device with current feature set @all.  Will not
>  *      enable anything that is off in @mask. Returns the new feature set.
> 
> And NETIF_F_NETNS_LOCAL is on in mask.
> 
>>
>> May be a better solution is:
>>
>>         features = netdev_increment_features(vlan->lowerdev->features & MACVLAN_FEATURS,
>>                                              features,
>>                                              mask);
>>
>> This way we start with only the feature MACVLAN is interested in.
>>
> 
> Or clear it in mask?
> 

Re: Cannot move macvlan interface on top of bonding device

[Florian Westphal]

Vlad Yasevich <vyasevich@gmail.com> wrote:
> On 09/17/2014 03:06 PM, Florian Westphal wrote:
> > Cong Wang <cwang@twopensource.com> wrote:
> >> On Wed, Sep 17, 2014 at 8:56 AM, Francesco Ruggeri <fruggeri@arista.com> wrote:
> >>> This used to work in older releases.
> >>> The problem seems to be that commit f939981492 sets NETIF_F_NETNS_LOCAL
> >>> on bonding interfaces, and commit 797f87f83 causes macvlan interfaces
> >>> to inherit its features from the lower device.
> >>>
> >>> Is there a reason why NETIF_F_NETNS_LOCAL should be inherited from the
> >>> lower device
> >>> by macvlan interfaces?
> >>
> >> commit 797f87f83 looks wrong, it should not inherit NETIF_F_NETNS_LOCAL,
> >> so just clear this flag. Please submit a patch.
> > 
> > Under which conditions would NETIF_F_NETNS_LOCAL have to be inherited?
> > (i.e., why is it inheritable in the first place?)

To answer my own question:  Its inherited since lowerdev->features is
passed as 'all' flag, so we would 'decrement' feature set if we'd remove
it in _increment_features().

> macvlan code calls
>         features = netdev_increment_features(vlan->lowerdev->features,
>                                              features,
>                                              mask);
> 
> where lowerdev->features contains the NETIF_F_NETNS_LOCAL bit.  That

[..]

> May be a better solution is:
> 
>         features = netdev_increment_features(vlan->lowerdev->features & MACVLAN_FEATURS,
>                                              features,
>                                              mask);
> 
> This way we start with only the feature MACVLAN is interested in.

Seems correct, since it will also prevent other non-macvlan features from
appearing.

Thanks Vlad.

Re: Cannot move macvlan interface on top of bonding device

[Francesco Ruggeri]

>
>> May be a better solution is:
>>
>>         features = netdev_increment_features(vlan->lowerdev->features & MACVLAN_FEATURS,
>>                                              features,
>>                                              mask);
>>
>> This way we start with only the feature MACVLAN is interested in.
>
> Seems correct, since it will also prevent other non-macvlan features from
> appearing.
>
> Thanks Vlad.

I verified that this approach also solves my original problem (moving
a macvlan on top of a bonding device to a different namespace).
I do not know how to fully test it with different types of lower
devices and features though.
If anybody wants to take the lead on this it would be great. Otherwise
a more limited patch only clearing the  NETIF_F_NETNS_LOCAL bit was
also submitted earlier
(http://marc.info/?l=linux-netdev&m=141097807310566&w=2).

Thanks,
Francesco