linux-kernel - Re: [PATCH RFT] net: dsa: Allow configuring CPU port VLANs

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Message-ID: <CAJGZr0JaqBt0BdoCAmjnMT9zN8cjBnJKJJGzWrThTjBKtwp-vA@mail.gmail.com>
Date:   Tue, 28 Aug 2018 22:08:38 +0300
From:   Maxim Uvarov <muvarov@...il.com>
To:     Florian Fainelli <f.fainelli@...il.com>
Cc:     Ilias Apalodimas <ilias.apalodimas@...aro.org>, petrm@...lanox.com,
        netdev <netdev@...r.kernel.org>, jiri@...lanox.com,
        Andrew Lunn <andrew@...n.ch>,
        Vivien Didelot <vivien.didelot@...oirfairelinux.com>,
        David Miller <davem@...emloft.net>,
        kernel list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH RFT] net: dsa: Allow configuring CPU port VLANs

вт, 28 авг. 2018 г. в 20:00, Florian Fainelli <f.fainelli@...il.com>:
>
> On 08/28/2018 01:32 AM, Ilias Apalodimas wrote:
> > On Fri, Aug 10, 2018 at 04:58:10PM -0700, Florian Fainelli wrote:
> >> On 06/25/2018 02:17 AM, Ilias Apalodimas wrote:
> >>> On Mon, Jun 25, 2018 at 12:13:10PM +0300, Petr Machata wrote:
> >>>> Florian Fainelli <f.fainelli@...il.com> writes:
> >>>>
> >>>>>   if (netif_is_bridge_master(vlan->obj.orig_dev))
> >>>>> -         return -EOPNOTSUPP;
> >>>>> +         info.port = dp->cpu_dp->index;
> >>>>
> >>>> The condition above will trigger also when a VLAN is added on a member
> >>>> port, and there's no other port with that VLAN. In that case the VLAN
> >>>> comes without the BRIDGE_VLAN_INFO_BRENTRY flag. In mlxsw we have this
> >>>> to get the bridge VLANs:
> >>>>
> >>>>    if (netif_is_bridge_master(orig_dev)) {
> >>>>            [...]
> >>>>            if ((vlan->flags & BRIDGE_VLAN_INFO_BRENTRY) &&
> >>>>            [...]
> >>>>
> >>>> This doesn't appear to be done in DSA unless I'm missing something.
> >>> Petr's right. This will trigger for VLANs added on 'not cpu ports' if the VLAN
> >>> is not already a member.
> >>>
> >>> This command has BRIDGE_VLAN_INFO_BRENTRY set:
> >>> bridge vlan add dev br0 vid 100 pvid untagged self
> >>> I had the same issue on my CPSW RFC and solved it
> >>> exactly the same was as Petr suggested.
> >>
> >> Humm, there must be something obvious I am missing, but the following
> >> don't exactly result in what I would expect after adding a check for
> >> vlan->flags & BRIDGE_VLAN_INFO_BRENTRY:
> >>
> >> brctl addbr br0
> >> echo 1 > /sys/class/net/br0/bridge/vlan_filtering
> >> brctl addif br0 lan1
> >>
> >> #1 results in lan1 being programmed with VID 1, PVID, untagged, but not
> >> the CPU port. I would have sort of expected that the bridge layer would
> >> also push the configuration to br0/CPU port since this is the default VLAN:
> >>
> >> bridge vlan show dev br0
> >> port vlan ids
> >> br0  1 PVID Egress Untagged
> >>
> >> But it does not.
> >>
> >> bridge vlan add vid 2 dev lan1
> >>
> >> #2 same thing, results in only lan1 being programmed with VID 2, tagged
> >> but that is expected because we are creating the VLAN only for the
> >> user-facing port.
> >>
> >> bridge vlan add vid 3 dev br0 self
> >>
> >> #3 results in the CPU port being programmed with VID 3, tagged, again,
> >> this is expected because we are only programming the bridge master/CPU
> >> port here.
> >>
> >> Does #1 also happen for cpsw and mlxsw or do you actually get events
> >> about the bridge's default VLAN configuration? Or does the switch driver
> >> actually need to obtain that at the time the port is enslaved somehow?
> > As long as ports are attached you get the events (one event per attached port
> > iirc)
> > if the event is checked against BRIDGE_VLAN_INFO_BRENTRY, the only way to add a
> > VLAN to the cpu port is via 'bridge vlan add vid 3 dev br0 self'
>
> Do we have a guarantee that upon port enslavement, whatever default_pvid
> is configured on the bridge master device also happens to be the port's
> default_pvid settings as well?

I think default pvid is per port thing. I.e. each port can have it's
own pvid (i.e. it will tag with vlan id not tagged incoming packet to
that port),
I did not exactly understand use case. With adding vlan filtering to
cpu port you filter out packets from other vlan groups to cpu port.
This might be useful
only for multicast packes or missing fbd entry on some dsa port. Is
filtering multicast a main problem to solve here?
Linux is missing vlan ingress policy. I.e. filtering (echo 1 >
/sys/br0/vlan_filter) has to be case of 3 policies: secure (default
now), check and fallback. With current secure mode it
might work, but with check mode it will be needed to add all vlans to
cpu port. Btw, on some hardware vlan ingress policies are also per
port, not per bridge.

Best regards,
Maxim.

> --
> Florian



-- 
Best regards,
Maxim Uvarov