From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94C01CCA47B for ; Sun, 17 Jul 2022 13:09:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232841AbiGQNJU (ORCPT ); Sun, 17 Jul 2022 09:09:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45458 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229698AbiGQNJR (ORCPT ); Sun, 17 Jul 2022 09:09:17 -0400 Received: from mailout-taastrup.gigahost.dk (mailout-taastrup.gigahost.dk [46.183.139.199]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 742B16577; Sun, 17 Jul 2022 06:09:12 -0700 (PDT) Received: from mailout.gigahost.dk (mailout.gigahost.dk [89.186.169.112]) by mailout-taastrup.gigahost.dk (Postfix) with ESMTP id 2EE851884E89; Sun, 17 Jul 2022 13:09:11 +0000 (UTC) Received: from smtp.gigahost.dk (smtp.gigahost.dk [89.186.169.109]) by mailout.gigahost.dk (Postfix) with ESMTP id 207A725032B7; Sun, 17 Jul 2022 13:09:11 +0000 (UTC) Received: by smtp.gigahost.dk (Postfix, from userid 1000) id 16DC0A1E00AE; Sun, 17 Jul 2022 13:09:11 +0000 (UTC) X-Screener-Id: 413d8c6ce5bf6eab4824d0abaab02863e8e3f662 MIME-Version: 1.0 Date: Sun, 17 Jul 2022 15:09:10 +0200 From: netdev@kapio-technology.com To: Vladimir Oltean Cc: Ido Schimmel , davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org, Andrew Lunn , Vivien Didelot , Florian Fainelli , Eric Dumazet , Paolo Abeni , Jiri Pirko , Ivan Vecera , Roopa Prabhu , Nikolay Aleksandrov , Shuah Khan , Daniel Borkmann , linux-kernel@vger.kernel.org, bridge@lists.linux-foundation.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH v4 net-next 3/6] drivers: net: dsa: add locked fdb entry flag to drivers In-Reply-To: <20220717125718.mj7b3j3jmltu6gm5@skbuf> References: <20220708084904.33otb6x256huddps@skbuf> <20220708091550.2qcu3tyqkhgiudjg@skbuf> <20220708115624.rrjzjtidlhcqczjv@skbuf> <723e2995314b41ff323272536ef27341@kapio-technology.com> <648ba6718813bf76e7b973150b73f028@kapio-technology.com> <20220717125718.mj7b3j3jmltu6gm5@skbuf> User-Agent: Gigahost Webmail Message-ID: X-Sender: netdev@kapio-technology.com Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022-07-17 14:57, Vladimir Oltean wrote: > On Sun, Jul 17, 2022 at 02:21:47PM +0200, netdev@kapio-technology.com > wrote: >> On 2022-07-13 14:39, Ido Schimmel wrote: >> > On Wed, Jul 13, 2022 at 09:09:58AM +0200, netdev@kapio-technology.com >> > wrote: >> >> > >> > What are "Storm Prevention" and "zero-DPV" FDB entries? >> >> They are both FDB entries that at the HW level drops all packets >> having a >> specific SA, thus using minimum resources. >> (thus the name "Storm Prevention" aka, protection against DOS attacks. >> We >> must remember that we operate with CPU based learning.) > > DPV means Destination Port Vector, and an ATU entry with a DPV of 0 > essentially means a FDB entry pointing nowhere, so it will drop the > packet. That's a slight problem with Hans' implementation, the bridge > thinks that the locked FDB entry belongs to port X, but in reality it > matches on all bridged ports (since it matches by FID). FID allocation > in mv88e6xxx is slightly strange, all VLAN-unaware bridge ports, > belonging to any bridge, share the same FID, so the FDB databases are > not exactly isolated from each other. But if the locked port is vlan aware and has a pvid, it should not block other ports. Besides the fid will be zero with vlan unaware afaik, and all with zero fid do not create locked entries. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.osuosl.org 02A9D840B2 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.osuosl.org 64E0F84098 MIME-Version: 1.0 Date: Sun, 17 Jul 2022 15:09:10 +0200 From: netdev@kapio-technology.com In-Reply-To: <20220717125718.mj7b3j3jmltu6gm5@skbuf> References: <20220708084904.33otb6x256huddps@skbuf> <20220708091550.2qcu3tyqkhgiudjg@skbuf> <20220708115624.rrjzjtidlhcqczjv@skbuf> <723e2995314b41ff323272536ef27341@kapio-technology.com> <648ba6718813bf76e7b973150b73f028@kapio-technology.com> <20220717125718.mj7b3j3jmltu6gm5@skbuf> Message-ID: Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Bridge] [PATCH v4 net-next 3/6] drivers: net: dsa: add locked fdb entry flag to drivers List-Id: Linux Ethernet Bridging List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Vladimir Oltean Cc: Ivan Vecera , Andrew Lunn , Florian Fainelli , Jiri Pirko , Daniel Borkmann , bridge@lists.linux-foundation.org, Ido Schimmel , Nikolay Aleksandrov , Roopa Prabhu , linux-kernel@vger.kernel.org, Vivien Didelot , Eric Dumazet , linux-kselftest@vger.kernel.org, netdev@vger.kernel.org, kuba@kernel.org, Paolo Abeni , Shuah Khan , davem@davemloft.net On 2022-07-17 14:57, Vladimir Oltean wrote: > On Sun, Jul 17, 2022 at 02:21:47PM +0200, netdev@kapio-technology.com > wrote: >> On 2022-07-13 14:39, Ido Schimmel wrote: >> > On Wed, Jul 13, 2022 at 09:09:58AM +0200, netdev@kapio-technology.com >> > wrote: >> >> > >> > What are "Storm Prevention" and "zero-DPV" FDB entries? >> >> They are both FDB entries that at the HW level drops all packets >> having a >> specific SA, thus using minimum resources. >> (thus the name "Storm Prevention" aka, protection against DOS attacks. >> We >> must remember that we operate with CPU based learning.) > > DPV means Destination Port Vector, and an ATU entry with a DPV of 0 > essentially means a FDB entry pointing nowhere, so it will drop the > packet. That's a slight problem with Hans' implementation, the bridge > thinks that the locked FDB entry belongs to port X, but in reality it > matches on all bridged ports (since it matches by FID). FID allocation > in mv88e6xxx is slightly strange, all VLAN-unaware bridge ports, > belonging to any bridge, share the same FID, so the FDB databases are > not exactly isolated from each other. But if the locked port is vlan aware and has a pvid, it should not block other ports. Besides the fid will be zero with vlan unaware afaik, and all with zero fid do not create locked entries.