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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AA0CEC0502A for ; Sun, 28 Aug 2022 11:25:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Message-ID:References:In-Reply-To:Subject:Cc:To:From :Date:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=BYPm4rocuHo7E0R3DoZjqSVtKl+P7JIzQxbD9HcCzxw=; b=mPyYDoq/uwKSwidMQaYTqfXwBz Ytx1qbVVIbCXC3R5W5glzdGlJwiIST+xsLsfwTWc78hg/23d5bOv6fJ2Cyo0M4EtXL5U/WGuPHLaY 43CvYKnAEjz6b+3W6xiHCOx5OCr42OSImaNn/ZWElE8T1ZrPd92yR6UIYQw8oLHJTxHWPmZTnUv6D M8oI2O6EQ79MEauGHRor4Chksl9g3qI97oFy6s+u8ErIv0P3D+bP5jQWuGavSt426owd0hLkTmOQv D388XvI3V6QlsFJiPJUQPHBalwxebwpNMfo2eENfWCyP4sB7HGNrm1PSTYF+zwJUeQM4zgs6u7MUq V9djZGcw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oSGP5-00GQVe-0V; Sun, 28 Aug 2022 11:24:35 +0000 Received: from mailout-taastrup.gigahost.dk ([46.183.139.199]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oSGOz-00GQOb-FT; Sun, 28 Aug 2022 11:24:32 +0000 Received: from mailout.gigahost.dk (mailout.gigahost.dk [89.186.169.112]) by mailout-taastrup.gigahost.dk (Postfix) with ESMTP id 3FF611884659; Sun, 28 Aug 2022 11:24:23 +0000 (UTC) Received: from smtp.gigahost.dk (smtp.gigahost.dk [89.186.169.109]) by mailout.gigahost.dk (Postfix) with ESMTP id 1F69425032B8; Sun, 28 Aug 2022 11:24:23 +0000 (UTC) Received: by smtp.gigahost.dk (Postfix, from userid 1000) id 1590D9EC0009; Sun, 28 Aug 2022 11:24:23 +0000 (UTC) X-Screener-Id: 413d8c6ce5bf6eab4824d0abaab02863e8e3f662 MIME-Version: 1.0 Date: Sun, 28 Aug 2022 13:24:22 +0200 From: netdev@kapio-technology.com To: Ido Schimmel Cc: Nikolay Aleksandrov , davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org, Florian Fainelli , Andrew Lunn , Vivien Didelot , Vladimir Oltean , Eric Dumazet , Paolo Abeni , Kurt Kanzenbach , Hauke Mehrtens , Woojung Huh , UNGLinuxDriver@microchip.com, Sean Wang , Landen Chao , DENG Qingfang , Matthias Brugger , Claudiu Manoil , Alexandre Belloni , Jiri Pirko , Ivan Vecera , Roopa Prabhu , Shuah Khan , Christian Marangi , Daniel Borkmann , Yuwei Wang , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, bridge@lists.linux-foundation.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH v5 net-next 1/6] net: bridge: add locked entry fdb flag to extend locked port feature In-Reply-To: References: <20220826114538.705433-1-netdev@kapio-technology.com> <20220826114538.705433-2-netdev@kapio-technology.com> User-Agent: Gigahost Webmail Message-ID: <48ac861433e3c608c8630300efe4e828@kapio-technology.com> X-Sender: netdev@kapio-technology.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220828_042431_580102_14BBAEDE X-CRM114-Status: GOOD ( 30.32 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2022-08-27 15:17, Ido Schimmel wrote: > On Sat, Aug 27, 2022 at 02:30:25PM +0300, Nikolay Aleksandrov wrote: >> On 26/08/2022 14:45, Hans Schultz wrote: >> Please add the blackhole flag in a separate patch. > > +1 > > [...] > >> > @@ -185,6 +196,9 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb >> > if (test_bit(BR_FDB_LOCAL, &dst->flags)) >> > return br_pass_frame_up(skb); >> > >> > + if (test_bit(BR_FDB_BLACKHOLE, &dst->flags)) >> > + goto drop; >> > + >> Not happy about adding a new test in arguably the most used fast-path, >> but I don't see >> a better way to do blackhole right now. Could you please make it an >> unlikely() ? >> >> I guess the blackhole flag will be allowed for user-space to set at >> some point, why >> not do it from the start? >> >> Actually adding a BR_FDB_LOCAL and BR_FDB_BLACKHOLE would be a >> conflict above - >> the packet will be received. So you should move the blackhole check >> above the >> BR_FDB_LOCAL one if user-space is allowed to set it to any entry. > > Agree about unlikely() and making it writeable from user space from the > start. This flag is different from the "locked" flag that should only > be > ever set by the kernel. > > Regarding BR_FDB_LOCAL, I think BR_FDB_BLACKHOLE should only be allowed > with BR_FDB_LOCAL as these entries are similar in the following ways: > > 1. It doesn't make sense to associate a blackhole entry with a specific > port. The packet will never be forwarded to this port, but dropped by > the bridge. This means user space will add them on the bridge itself: > > # bridge fdb add 00:11:22:33:44:55 dev br0 self local blackhole > > 2. If you agree that these entries should not be associated with a > specific port, then it also does not make sense to subject them to > ageing and roaming, just like existing local/permanent entries. > > The above allows us to push the new check under the BR_FDB_LOCAL check: > > diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c > index 68b3e850bcb9..4357445529a5 100644 > --- a/net/bridge/br_input.c > +++ b/net/bridge/br_input.c > @@ -182,8 +182,11 @@ int br_handle_frame_finish(struct net *net, > struct sock *sk, struct sk_buff *skb > if (dst) { > unsigned long now = jiffies; > > - if (test_bit(BR_FDB_LOCAL, &dst->flags)) > + if (test_bit(BR_FDB_LOCAL, &dst->flags)) { > + if (unlikely(test_bit(BR_FDB_BLACKHOLE, > &dst->flags))) > + goto drop; > return br_pass_frame_up(skb); > + } > > if (now != dst->used) > dst->used = now; It shall be so as suggested. :-) _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel