From: Jakub Kicinski <kuba@kernel.org>
To: "Markus Blöchl" <markus.bloechl@ipetronik.com>,
"Ido Schimmel" <idosch@idosch.org>,
"Andrew Lunn" <andrew@lunn.ch>,
"Vladimir Oltean" <olteanv@gmail.com>,
"Alexander Duyck" <alexander.duyck@gmail.com>
Cc: Woojung Huh <woojung.huh@microchip.com>,
"David S. Miller" <davem@davemloft.net>,
Microchip Linux Driver Support <UNGLinuxDriver@microchip.com>,
netdev@vger.kernel.org
Subject: Re: [PATCH net] net: lan78xx: Disable hardware vlan filtering in promiscuous mode
Date: Thu, 12 Nov 2020 16:44:57 -0800 [thread overview]
Message-ID: <20201112164457.6af0fbaf@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> (raw)
In-Reply-To: <20201111074341.24cafaf3@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
On Wed, 11 Nov 2020 07:43:41 -0800 Jakub Kicinski wrote:
> > In order to receive those tagged frames it is necessary to manually disable
> > rx vlan filtering using ethtool ( `ethtool -K ethX rx-vlan-filter off` or
> > corresponding ioctls ). Setting all bits in the vlan filter table to 1 is
> > an even worse approach, imho.
> >
> > As a user I would probably expect that setting IFF_PROMISC should be enough
> > in all cases to receive all valid traffic.
> > Therefore I think this behaviour is a bug in the driver, since other
> > drivers (notably ixgbe) automatically disable rx-vlan-filter when
> > IFF_PROMISC is set. Please correct me if I am wrong here.
>
> I've been mulling over this, I'm not 100% sure that disabling VLAN
> filters on promisc is indeed the right thing to do. The ixgbe doing
> this is somewhat convincing. OTOH users would not expect flow filters
> to get disabled when promisc is on, so why disable vlan filters?
>
> Either way we should either document this as an expected behavior or
> make the core clear the features automatically rather than force
> drivers to worry about it.
>
> Does anyone else have an opinion, please?
Okay, I feel convinced that we should indeed let all vlan traffic thru,
thanks everyone! :)
Markus could you try to come up with a patch for the net/core/dev.c
handling which would clear NETIF_F_HW_VLAN_CTAG_FILTER and
NETIF_F_HW_VLAN_STAG_FILTER automatically so the drivers don't have
to worry?
Whatever the driver chooses to do to disable vlan filtering is a
separate discussion AFAICT.
prev parent reply other threads:[~2020-11-13 0:45 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-10 15:39 [PATCH net] net: lan78xx: Disable hardware vlan filtering in promiscuous mode Markus Blöchl
2020-11-11 3:13 ` Jakub Kicinski
2020-11-11 15:43 ` Jakub Kicinski
2020-11-11 15:56 ` Florian Fainelli
2020-11-11 16:47 ` Vladimir Oltean
2020-11-11 17:14 ` Vladimir Oltean
2020-11-12 10:53 ` Markus Blöchl
2020-11-14 18:11 ` Vladimir Oltean
2020-11-19 15:37 ` Markus Blöchl
2020-11-19 16:28 ` Vladimir Oltean
2020-11-19 17:31 ` Jakub Kicinski
2020-11-11 18:02 ` Ido Schimmel
2020-11-12 22:52 ` Alexander Duyck
2020-11-13 0:44 ` Jakub Kicinski [this message]
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