[PATCH net] net: dsa: b53: Ensure the default VID is untagged

[PATCH net] net: dsa: b53: Ensure the default VID is untagged

[Florian Fainelli]

We need to ensure that the default VID is untagged otherwise the switch
will be sending frames tagged frames and the results can be problematic.
This is especially true with b53 switches that use VID 0 as their
default VLAN since VID 0 has a special meaning.

Fixes: fea83353177a ("net: dsa: b53: Fix default VLAN ID")
Fixes: 061f6a505ac3 ("net: dsa: Add ndo_vlan_rx_{add, kill}_vid implementation")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/net/dsa/b53/b53_common.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
index 449a22172e07..f25c43b300d4 100644
--- a/drivers/net/dsa/b53/b53_common.c
+++ b/drivers/net/dsa/b53/b53_common.c
@@ -1366,6 +1366,9 @@ void b53_vlan_add(struct dsa_switch *ds, int port,
 
 		b53_get_vlan_entry(dev, vid, vl);
 
+		if (vid == b53_default_pvid(dev))
+			untagged = true;
+
 		vl->members |= BIT(port);
 		if (untagged && !dsa_is_cpu_port(ds, port))
 			vl->untag |= BIT(port);
-- 
2.17.1

Re: [PATCH net] net: dsa: b53: Ensure the default VID is untagged

[Sergei Shtylyov]

Hello!

On 13.02.2020 22:10, Florian Fainelli wrote:

> We need to ensure that the default VID is untagged otherwise the switch
> will be sending frames tagged frames and the results can be problematic.
                   ^^^^^^^^^^^^^^^^^^^^

   Perhaps just "tagged frames"?

> This is especially true with b53 switches that use VID 0 as their
> default VLAN since VID 0 has a special meaning.
> 
> Fixes: fea83353177a ("net: dsa: b53: Fix default VLAN ID")
> Fixes: 061f6a505ac3 ("net: dsa: Add ndo_vlan_rx_{add, kill}_vid implementation")
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
[...]

MBR, Sergei

Re: [PATCH net] net: dsa: b53: Ensure the default VID is untagged

[Vladimir Oltean]

Hi Florian,

On Thu, 13 Feb 2020 at 21:10, Florian Fainelli <f.fainelli@gmail.com> wrote:
>
> We need to ensure that the default VID is untagged otherwise the switch
> will be sending frames tagged frames and the results can be problematic.
> This is especially true with b53 switches that use VID 0 as their
> default VLAN since VID 0 has a special meaning.
>
> Fixes: fea83353177a ("net: dsa: b53: Fix default VLAN ID")
> Fixes: 061f6a505ac3 ("net: dsa: Add ndo_vlan_rx_{add, kill}_vid implementation")
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> ---
>  drivers/net/dsa/b53/b53_common.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
> index 449a22172e07..f25c43b300d4 100644
> --- a/drivers/net/dsa/b53/b53_common.c
> +++ b/drivers/net/dsa/b53/b53_common.c
> @@ -1366,6 +1366,9 @@ void b53_vlan_add(struct dsa_switch *ds, int port,
>
>                 b53_get_vlan_entry(dev, vid, vl);
>
> +               if (vid == b53_default_pvid(dev))
> +                       untagged = true;
> +
>                 vl->members |= BIT(port);
>                 if (untagged && !dsa_is_cpu_port(ds, port))
>                         vl->untag |= BIT(port);
> --
> 2.17.1
>

Don't you mean to force untagged egress only for the pvid value of 0?

Thanks,
-Vladimir

Re: [PATCH net] net: dsa: b53: Ensure the default VID is untagged

[Florian Fainelli]

On 2/14/2020 2:36 AM, Vladimir Oltean wrote:
> Hi Florian,
> 
> On Thu, 13 Feb 2020 at 21:10, Florian Fainelli <f.fainelli@gmail.com> wrote:
>>
>> We need to ensure that the default VID is untagged otherwise the switch
>> will be sending frames tagged frames and the results can be problematic.
>> This is especially true with b53 switches that use VID 0 as their
>> default VLAN since VID 0 has a special meaning.
>>
>> Fixes: fea83353177a ("net: dsa: b53: Fix default VLAN ID")
>> Fixes: 061f6a505ac3 ("net: dsa: Add ndo_vlan_rx_{add, kill}_vid implementation")
>> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
>> ---
>>  drivers/net/dsa/b53/b53_common.c | 3 +++
>>  1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
>> index 449a22172e07..f25c43b300d4 100644
>> --- a/drivers/net/dsa/b53/b53_common.c
>> +++ b/drivers/net/dsa/b53/b53_common.c
>> @@ -1366,6 +1366,9 @@ void b53_vlan_add(struct dsa_switch *ds, int port,
>>
>>                 b53_get_vlan_entry(dev, vid, vl);
>>
>> +               if (vid == b53_default_pvid(dev))
>> +                       untagged = true;
>> +
>>                 vl->members |= BIT(port);
>>                 if (untagged && !dsa_is_cpu_port(ds, port))
>>                         vl->untag |= BIT(port);
>> --
>> 2.17.1
>>
> 
> Don't you mean to force untagged egress only for the pvid value of 0?

The default VID (0 for most switches, 1 for 5325/65) is configured as
pvid during b53_configure_vlan() so when we get a call to port_vlan_add
with VID == 0 this is coming exclusively from
dsa_slave_vlan_rx_add_vid() since the bridge will never program a VID <
1. When dsa_slave_vlan_rx_add_vid() calls us, we do not have any VLAN
flags set in the object.
-- 
Florian

Re: [PATCH net] net: dsa: b53: Ensure the default VID is untagged

[Vladimir Oltean]

On Fri, 14 Feb 2020 at 19:08, Florian Fainelli <f.fainelli@gmail.com> wrote:
>
>
>
> On 2/14/2020 2:36 AM, Vladimir Oltean wrote:
> > Hi Florian,
> >
> > On Thu, 13 Feb 2020 at 21:10, Florian Fainelli <f.fainelli@gmail.com> wrote:
> >>
> >> We need to ensure that the default VID is untagged otherwise the switch
> >> will be sending frames tagged frames and the results can be problematic.
> >> This is especially true with b53 switches that use VID 0 as their
> >> default VLAN since VID 0 has a special meaning.
> >>
> >> Fixes: fea83353177a ("net: dsa: b53: Fix default VLAN ID")
> >> Fixes: 061f6a505ac3 ("net: dsa: Add ndo_vlan_rx_{add, kill}_vid implementation")
> >> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> >> ---
> >>  drivers/net/dsa/b53/b53_common.c | 3 +++
> >>  1 file changed, 3 insertions(+)
> >>
> >> diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
> >> index 449a22172e07..f25c43b300d4 100644
> >> --- a/drivers/net/dsa/b53/b53_common.c
> >> +++ b/drivers/net/dsa/b53/b53_common.c
> >> @@ -1366,6 +1366,9 @@ void b53_vlan_add(struct dsa_switch *ds, int port,
> >>
> >>                 b53_get_vlan_entry(dev, vid, vl);
> >>
> >> +               if (vid == b53_default_pvid(dev))
> >> +                       untagged = true;
> >> +
> >>                 vl->members |= BIT(port);
> >>                 if (untagged && !dsa_is_cpu_port(ds, port))
> >>                         vl->untag |= BIT(port);
> >> --
> >> 2.17.1
> >>
> >
> > Don't you mean to force untagged egress only for the pvid value of 0?
>
> The default VID (0 for most switches, 1 for 5325/65) is configured as
> pvid during b53_configure_vlan() so when we get a call to port_vlan_add
> with VID == 0 this is coming exclusively from
> dsa_slave_vlan_rx_add_vid() since the bridge will never program a VID <
> 1. When dsa_slave_vlan_rx_add_vid() calls us, we do not have any VLAN
> flags set in the object.
> --
> Florian

Exactly. So the only case you need to guard against is when vid == 0
&& vid == b53_default_pvid(dev) - basically the 8021q module messing
with your untagged (pvid-tagged) traffic. So both have to be zero in
order to interfere. If vid is 0 but the b53_default_pvid is 1 - no
problem. If vid is 1 and the b53_default_pvid is 1, again no problem.
At least that's what you described in the previous patch. No?

-Vladimir