From: Vladimir Oltean <olteanv@gmail.com>
To: Tobias Waldekranz <tobias@waldekranz.com>
Cc: Jakub Kicinski <kuba@kernel.org>,
"David S. Miller" <davem@davemloft.net>,
Andrew Lunn <andrew@lunn.ch>,
Vivien Didelot <vivien.didelot@gmail.com>,
Florian Fainelli <f.fainelli@gmail.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
Roopa Prabhu <roopa@nvidia.com>,
Nikolay Aleksandrov <nikolay@nvidia.com>,
Jiri Pirko <jiri@resnulli.us>, Ido Schimmel <idosch@idosch.org>,
Alexandre Belloni <alexandre.belloni@bootlin.com>,
UNGLinuxDriver@microchip.com, Vadym Kochan <vkochan@marvell.com>,
Taras Chornyi <tchornyi@marvell.com>,
Grygorii Strashko <grygorii.strashko@ti.com>,
Vignesh Raghavendra <vigneshr@ti.com>,
Ioana Ciornei <ioana.ciornei@nxp.com>,
Ivan Vecera <ivecera@redhat.com>,
linux-omap@vger.kernel.org,
Vladimir Oltean <vladimir.oltean@nxp.com>
Subject: Re: [RFC PATCH v2 net-next 09/16] net: dsa: replay port and local fdb entries when joining the bridge
Date: Mon, 22 Mar 2021 19:13:28 +0200 [thread overview]
Message-ID: <20210322171328.6ctmzyullywm3qmk@skbuf> (raw)
In-Reply-To: <87o8fbm80o.fsf@waldekranz.com>
On Mon, Mar 22, 2021 at 06:07:51PM +0100, Tobias Waldekranz wrote:
> On Mon, Mar 22, 2021 at 18:19, Vladimir Oltean <olteanv@gmail.com> wrote:
> > On Mon, Mar 22, 2021 at 04:44:41PM +0100, Tobias Waldekranz wrote:
> >> I do not know if it is a problem or not, more of an observation: This is
> >> not guaranteed to be an exact replay of the events that the bridge port
> >> (i.e. bond0 or whatever) has received since, in fdb_insert, we exit
> >> early when adding local entries if that address is already in the
> >> database.
> >>
> >> Do we have to guard against this somehow? Or maybe we should consider
> >> the current behavior a bug and make sure to always send the event in the
> >> first place?
> >
> > I don't really understand what you're saying.
> > fdb_insert has:
> >
> > fdb = br_fdb_find(br, addr, vid);
> > if (fdb) {
> > /* it is okay to have multiple ports with same
> > * address, just use the first one.
> > */
> > if (test_bit(BR_FDB_LOCAL, &fdb->flags))
> > return 0;
> > br_warn(br, "adding interface %s with same address as a received packet (addr:%pM, vlan:%u)\n",
> > source ? source->dev->name : br->dev->name, addr, vid);
> > fdb_delete(br, fdb, true);
> > }
> >
> > fdb = fdb_create(br, source, addr, vid,
> > BIT(BR_FDB_LOCAL) | BIT(BR_FDB_STATIC));
> >
> > Basically, if the {addr, vid} pair already exists in the fdb, and it
> > points to a local entry, fdb_create is bypassed.
> >
> > Whereas my br_fdb_replay() function iterates over br->fdb_list, which is
> > exactly where fdb_create() also lays its eggs. That is to say, unless
> > I'm missing something, that duplicate local FDB entries that skipped the
> > fdb_create() call in fdb_insert() because they were for already-existing
> > local FDB entries will also be skipped by br_fdb_replay(), because it
> > iterates over a br->fdb_list which contains unique local addresses.
> > Where am I wrong?
>
> No you are right. I was thinking back to my attempt of offloading local
> addresses and I distinctly remembered that local addresses could be
> added without a notification being sent.
>
> But that is not what is happening. It is just already inserted on
> another port. So the notification would reach DSA, or not, depending on
> ordering the of events. But there will be no discrepancy between that
> and the replay.
I'm not saying that the bridge isn't broken, because it is, but for
different reasons, as explained here:
https://patchwork.kernel.org/project/netdevbpf/patch/20210224114350.2791260-9-olteanv@gmail.com/
What I can do is I can make br_switchdev_fdb_notify() skip fdb entries
with the BR_FDB_LOCAL bit set, and target that patch against "net", with
a Fixes: tag of 6b26b51b1d13 ("net: bridge: Add support for notifying
devices about FDB add/del").
Then I can also skip the entries with BR_FDB_LOCAL from br_fdb_replay.
Then, when I return to the "RX filtering for DSA" series, I can add the
"is_local" bit to switchdev FDB objects, and make all drivers reject
"is_local" entries (which is what the linked patch does) unless more
specific treatment is applied to those (trap to CPU).
Nikolay?
next prev parent reply other threads:[~2021-03-22 17:14 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-18 23:18 [RFC PATCH v2 net-next 00/16] Better support for sandwiched LAGs with bridge and DSA Vladimir Oltean
2021-03-18 23:18 ` [RFC PATCH v2 net-next 01/16] net: dsa: call dsa_port_bridge_join when joining a LAG that is already in a bridge Vladimir Oltean
2021-03-19 22:04 ` Florian Fainelli
2021-03-22 10:24 ` Tobias Waldekranz
2021-03-18 23:18 ` [RFC PATCH v2 net-next 02/16] net: dsa: pass extack to dsa_port_{bridge,lag}_join Vladimir Oltean
2021-03-19 22:05 ` Florian Fainelli
2021-03-22 10:25 ` Tobias Waldekranz
2021-03-18 23:18 ` [RFC PATCH v2 net-next 03/16] net: dsa: inherit the actual bridge port flags at join time Vladimir Oltean
2021-03-19 22:08 ` Florian Fainelli
2021-03-20 10:05 ` Vladimir Oltean
2021-03-18 23:18 ` [RFC PATCH v2 net-next 04/16] net: dsa: sync up with bridge port's STP state when joining Vladimir Oltean
2021-03-19 22:11 ` Florian Fainelli
2021-03-22 10:29 ` Tobias Waldekranz
2021-03-18 23:18 ` [RFC PATCH v2 net-next 05/16] net: dsa: sync up VLAN filtering state when joining the bridge Vladimir Oltean
2021-03-19 22:11 ` Florian Fainelli
2021-03-22 10:30 ` Tobias Waldekranz
2021-03-18 23:18 ` [RFC PATCH v2 net-next 06/16] net: dsa: sync multicast router " Vladimir Oltean
2021-03-19 22:12 ` Florian Fainelli
2021-03-22 11:17 ` Tobias Waldekranz
2021-03-22 11:43 ` Vladimir Oltean
2021-03-18 23:18 ` [RFC PATCH v2 net-next 07/16] net: dsa: sync ageing time " Vladimir Oltean
2021-03-19 22:13 ` Florian Fainelli
2021-03-20 10:09 ` Vladimir Oltean
2021-03-22 11:20 ` Tobias Waldekranz
2021-03-18 23:18 ` [RFC PATCH v2 net-next 08/16] net: dsa: replay port and host-joined mdb entries " Vladimir Oltean
2021-03-19 22:20 ` Florian Fainelli
2021-03-20 9:53 ` Vladimir Oltean
2021-03-22 15:56 ` Florian Fainelli
2021-03-18 23:18 ` [RFC PATCH v2 net-next 09/16] net: dsa: replay port and local fdb " Vladimir Oltean
2021-03-22 15:44 ` Tobias Waldekranz
2021-03-22 16:19 ` Vladimir Oltean
2021-03-22 17:07 ` Tobias Waldekranz
2021-03-22 17:13 ` Vladimir Oltean [this message]
2021-03-18 23:18 ` [RFC PATCH v2 net-next 10/16] net: dsa: replay VLANs installed on port " Vladimir Oltean
2021-03-19 22:24 ` Florian Fainelli
2021-03-18 23:18 ` [RFC PATCH v2 net-next 11/16] net: ocelot: support multiple bridges Vladimir Oltean
2021-03-18 23:18 ` [RFC PATCH v2 net-next 12/16] net: ocelot: call ocelot_netdevice_bridge_join when joining a bridged LAG Vladimir Oltean
2021-03-18 23:18 ` [RFC PATCH v2 net-next 13/16] net: ocelot: replay switchdev events when joining bridge Vladimir Oltean
2021-03-18 23:18 ` [RFC PATCH v2 net-next 14/16] net: dsa: don't set skb->offload_fwd_mark when not offloading the bridge Vladimir Oltean
2021-03-19 8:52 ` DENG Qingfang
2021-03-19 9:06 ` Vladimir Oltean
2021-03-19 9:29 ` DENG Qingfang
2021-03-19 10:49 ` Vladimir Oltean
2021-03-22 8:04 ` DENG Qingfang
2021-03-22 22:23 ` Vladimir Oltean
2021-03-22 16:06 ` Florian Fainelli
2021-03-18 23:18 ` [RFC PATCH v2 net-next 15/16] net: dsa: return -EOPNOTSUPP when driver does not implement .port_lag_join Vladimir Oltean
2021-03-22 15:51 ` Florian Fainelli
2021-03-22 15:58 ` Tobias Waldekranz
2021-03-18 23:18 ` [RFC PATCH v2 net-next 16/16] net: bridge: switchdev: let drivers inform which bridge ports are offloaded Vladimir Oltean
2021-03-22 16:30 ` Tobias Waldekranz
2021-03-22 17:19 ` Vladimir Oltean
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