Re: [PATCH resend net-next 2/2] net: bridge: switchdev: include local flag in FDB notifications

From: Vladimir Oltean <olteanv@gmail.com>
To: Ido Schimmel <idosch@idosch.org>
Cc: Jakub Kicinski <kuba@kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	netdev@vger.kernel.org, Ioana Ciornei <ioana.ciornei@nxp.com>,
	Vadym Kochan <vkochan@marvell.com>,
	Taras Chornyi <tchornyi@marvell.com>,
	Jiri Pirko <jiri@nvidia.com>, Ido Schimmel <idosch@nvidia.com>,
	Grygorii Strashko <grygorii.strashko@ti.com>,
	Ivan Vecera <ivecera@redhat.com>, Roopa Prabhu <roopa@nvidia.com>,
	Nikolay Aleksandrov <nikolay@nvidia.com>,
	Andrew Lunn <andrew@lunn.ch>,
	Vivien Didelot <vivien.didelot@gmail.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	Linus Walleij <linus.walleij@linaro.org>,
	linux-omap@vger.kernel.org,
	Vladimir Oltean <vladimir.oltean@nxp.com>,
	Tobias Waldekranz <tobias@waldekranz.com>
Subject: Re: [PATCH resend net-next 2/2] net: bridge: switchdev: include local flag in FDB notifications
Date: Fri, 16 Apr 2021 20:33:19 +0300	[thread overview]
Message-ID: <20210416173319.id4y37ecdmwd2u52@skbuf> (raw)
In-Reply-To: <YHmroFOPM3Hl/5uP@shredder.lan>

On Fri, Apr 16, 2021 at 06:22:08PM +0300, Ido Schimmel wrote:
> On Wed, Apr 14, 2021 at 07:52:56PM +0300, Vladimir Oltean wrote:
> > From: Vladimir Oltean <vladimir.oltean@nxp.com>
> > 
> > As explained in bugfix commit 6ab4c3117aec ("net: bridge: don't notify
> > switchdev for local FDB addresses") as well as in this discussion:
> > https://lore.kernel.org/netdev/20210117193009.io3nungdwuzmo5f7@skbuf/
> > 
> > the switchdev notifiers for FDB entries managed to have a zero-day bug,
> > which was that drivers would not know what to do with local FDB entries,
> > because they were not told that they are local. The bug fix was to
> > simply not notify them of those addresses.
> > 
> > Let us now add the 'is_local' bit to bridge FDB entries, and make all
> > drivers ignore these entries by their own choice.
> > 
> > Co-developed-by: Tobias Waldekranz <tobias@waldekranz.com>
> > Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
> > Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> 
> Reviewed-by: Ido Schimmel <idosch@nvidia.com>

Thanks!

> One comment below
> 
> > diff --git a/net/bridge/br_switchdev.c b/net/bridge/br_switchdev.c
> > index c390f84adea2..a5e601e41cb9 100644
> > --- a/net/bridge/br_switchdev.c
> > +++ b/net/bridge/br_switchdev.c
> > @@ -114,13 +114,12 @@ br_switchdev_fdb_notify(const struct net_bridge_fdb_entry *fdb, int type)
> >  		.addr = fdb->key.addr.addr,
> >  		.vid = fdb->key.vlan_id,
> >  		.added_by_user = test_bit(BR_FDB_ADDED_BY_USER, &fdb->flags),
> > +		.is_local = test_bit(BR_FDB_LOCAL, &fdb->flags),
> >  		.offloaded = test_bit(BR_FDB_OFFLOADED, &fdb->flags),
> >  	};
> >  
> >  	if (!fdb->dst)
> >  		return;
> 
> Do you plan to eventually remove this check so that entries pointing to
> the bridge device itself will be notified? For example:
> 
> # bridge fdb add 00:01:02:03:04:05 dev br0 self local
> 
> > -	if (test_bit(BR_FDB_LOCAL, &fdb->flags))
> > -		return;
> >  
> >  	switch (type) {
> >  	case RTM_DELNEIGH:

Yes I do, it's this patch over here:
https://patchwork.kernel.org/project/netdevbpf/patch/20210224114350.2791260-10-olteanv@gmail.com/

One at a time though.