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 X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 37F39C7618F for ; Sat, 27 Jul 2019 03:02:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F30B5216C8 for ; Sat, 27 Jul 2019 03:02:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="eUp19m/y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727959AbfG0DCd (ORCPT ); Fri, 26 Jul 2019 23:02:33 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:41242 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726184AbfG0DCd (ORCPT ); Fri, 26 Jul 2019 23:02:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=tN/4dk4E58XistgDJ6zOTKtSRYqHTx/a1QOwwGKZMmk=; b=eUp19m/y/Qg1oORIbOZgd/lgOH dU1x4yAORlsvB70utYGcZLTwWnbrpNdkE7MYvHycUmKDhdJNay1C1zWz9TrPxN3INRKVF9XHSSupf aBX961lzv4uzmUhvzpmGFQZqpRpzlpaSNm7sKFvaywt+8zVZA/E+URoyEHPR5rlto02w=; Received: from andrew by vps0.lunn.ch with local (Exim 4.89) (envelope-from ) id 1hrCyV-0007ol-5S; Sat, 27 Jul 2019 05:02:23 +0200 Date: Sat, 27 Jul 2019 05:02:23 +0200 From: Andrew Lunn To: "Allan W. Nielsen" Cc: Horatiu Vultur , Nikolay Aleksandrov , roopa@cumulusnetworks.com, davem@davemloft.net, bridge@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] net: bridge: Allow bridge to joing multicast groups Message-ID: <20190727030223.GA29731@lunn.ch> References: <1564055044-27593-1-git-send-email-horatiu.vultur@microchip.com> <7e7a7015-6072-d884-b2ba-0a51177245ab@cumulusnetworks.com> <20190725142101.65tusauc6fzxb2yp@soft-dev3.microsemi.net> <20190726120214.c26oj5vks7g5ntwu@soft-dev3.microsemi.net> <20190726134613.GD18223@lunn.ch> <20190726195010.7x75rr74v7ph3m6m@lx-anielsen.microsemi.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190726195010.7x75rr74v7ph3m6m@lx-anielsen.microsemi.net> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > As you properly guessed, this model is quite different from what we are used to. Yes, it takes a while to get the idea that the hardware is just an accelerator for what the Linux stack can already do. And if the switch cannot do some feature, pass the frame to Linux so it can handle it. You need to keep in mind that there could be other ports in the bridge than switch ports, and those ports might be interested in the multicast traffic. Hence the CPU needs to see the traffic. But IGMP snooping can be used to optimise this. But you still need to be careful, eg. IPv6 Neighbour discovery has often been broken on mv88e6xxx because we have been too aggressive with filtering multicast. Andrew From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=tN/4dk4E58XistgDJ6zOTKtSRYqHTx/a1QOwwGKZMmk=; b=eUp19m/y/Qg1oORIbOZgd/lgOH dU1x4yAORlsvB70utYGcZLTwWnbrpNdkE7MYvHycUmKDhdJNay1C1zWz9TrPxN3INRKVF9XHSSupf aBX961lzv4uzmUhvzpmGFQZqpRpzlpaSNm7sKFvaywt+8zVZA/E+URoyEHPR5rlto02w=; Date: Sat, 27 Jul 2019 05:02:23 +0200 From: Andrew Lunn Message-ID: <20190727030223.GA29731@lunn.ch> References: <1564055044-27593-1-git-send-email-horatiu.vultur@microchip.com> <7e7a7015-6072-d884-b2ba-0a51177245ab@cumulusnetworks.com> <20190725142101.65tusauc6fzxb2yp@soft-dev3.microsemi.net> <20190726120214.c26oj5vks7g5ntwu@soft-dev3.microsemi.net> <20190726134613.GD18223@lunn.ch> <20190726195010.7x75rr74v7ph3m6m@lx-anielsen.microsemi.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190726195010.7x75rr74v7ph3m6m@lx-anielsen.microsemi.net> Subject: Re: [Bridge] [PATCH] net: bridge: Allow bridge to joing multicast groups List-Id: Linux Ethernet Bridging List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Allan W. Nielsen" Cc: Nikolay Aleksandrov , netdev@vger.kernel.org, roopa@cumulusnetworks.com, bridge@lists.linux-foundation.org, linux-kernel@vger.kernel.org, davem@davemloft.net, Horatiu Vultur > As you properly guessed, this model is quite different from what we are used to. Yes, it takes a while to get the idea that the hardware is just an accelerator for what the Linux stack can already do. And if the switch cannot do some feature, pass the frame to Linux so it can handle it. You need to keep in mind that there could be other ports in the bridge than switch ports, and those ports might be interested in the multicast traffic. Hence the CPU needs to see the traffic. But IGMP snooping can be used to optimise this. But you still need to be careful, eg. IPv6 Neighbour discovery has often been broken on mv88e6xxx because we have been too aggressive with filtering multicast. Andrew