From patchwork Wed Jul 8 23:16:43 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Scott Feldman X-Patchwork-Id: 493191 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 0DCF21409A0 for ; Thu, 9 Jul 2015 09:14:42 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b=YcneS/zk; dkim-atps=neutral Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752685AbbGHXOi (ORCPT ); Wed, 8 Jul 2015 19:14:38 -0400 Received: from mail-pd0-f179.google.com ([209.85.192.179]:36336 "EHLO mail-pd0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751676AbbGHXOU (ORCPT ); Wed, 8 Jul 2015 19:14:20 -0400 Received: by pddu5 with SMTP id u5so66029458pdd.3 for ; Wed, 08 Jul 2015 16:14:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=QSuaeL/rt3ppCWBnjHogH8dtEzoDQwmRWk6oh18dVEU=; b=YcneS/zkNZ/joAKWoPLobdZIiXdXTr2KyjjF2oTUGseV5los2xxl0pPQTpznjlb6YM QAmY2MgKFHiDCu03f+lcyewljZ8ASjRL55RYibf4PMM+uBgiTOKgjf9PHnbLPbTxdArL JWYk7PJdHW3wlC515g3jMjmWeCcutvYls0sgip0BH+kaqZFSL/+B6iW4SlE+cDlWHHCF oix+0evZVE/6O8eZGv/ybqHJ7UnRH/8KF+1b94+3f2rWdkpDAofq+RaQtA9XNJXJaEOD C9ERntx4b24lOZRCsNUyos88k5XY0TurkIEliyPXCpplcOQXkt7SK2b+vR/bJrQQ4Gq7 373w== X-Received: by 10.70.89.170 with SMTP id bp10mr4337510pdb.30.1436397259363; Wed, 08 Jul 2015 16:14:19 -0700 (PDT) Received: from rocker1.rocker.net ([199.58.98.143]) by smtp.gmail.com with ESMTPSA id dc8sm3673599pdb.23.2015.07.08.16.14.17 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 08 Jul 2015 16:14:18 -0700 (PDT) From: sfeldma@gmail.com To: netdev@vger.kernel.org Cc: jiri@resnulli.us, roopa@cumulusnetworks.com Subject: [PATCH net-next 5/5] switchdev: update documentation for offload_fwd_mark Date: Wed, 8 Jul 2015 16:16:43 -0700 Message-Id: <1436397403-62412-6-git-send-email-sfeldma@gmail.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1436397403-62412-1-git-send-email-sfeldma@gmail.com> References: <1436397403-62412-1-git-send-email-sfeldma@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Scott Feldman Signed-off-by: Scott Feldman --- Documentation/networking/switchdev.txt | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/Documentation/networking/switchdev.txt b/Documentation/networking/switchdev.txt index c5d7ade..b864e47 100644 --- a/Documentation/networking/switchdev.txt +++ b/Documentation/networking/switchdev.txt @@ -279,8 +279,18 @@ and unknown unicast packets to all ports in domain, if allowed by port's current STP state. The switch driver, knowing which ports are within which vlan L2 domain, can program the switch device for flooding. The packet should also be sent to the port netdev for processing by the bridge driver. The -bridge should not reflood the packet to the same ports the device flooded. -XXX: the mechanism to avoid duplicate flood packets is being discuseed. +bridge should not reflood the packet to the same ports the device flooded, +otherwise there will be duplicate packets on the wire. + +To avoid duplicate packets, the device/driver can mark a packet as already +forwarded using skb->offload_fwd_mark. The same mark is set on the device +ports in the domain using dev->offload_fwd_mark. If the skb->offload_fwd_mark +is non-zero and matches the forwarding egress port's dev->skb_mark, the kernel +will drop the skb right before transmit on the egress port, with the +understanding that the device already forwarded the packet on same egress port. +The driver can use switchdev_port_fwd_mark_set() to set a globally unique mark +for port's dev->offload_fwd_mark, based on the port's parent ID (switch ID) and +a group ifindex. It is possible for the switch device to not handle flooding and push the packets up to the bridge driver for flooding. This is not ideal as the number