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=-6.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 3F369C4708F for ; Sat, 29 May 2021 21:10:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1C3D161108 for ; Sat, 29 May 2021 21:10:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229852AbhE2VLz (ORCPT ); Sat, 29 May 2021 17:11:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:36310 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229838AbhE2VLy (ORCPT ); Sat, 29 May 2021 17:11:54 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3334160E0C; Sat, 29 May 2021 21:10:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622322617; bh=kPOCKx/zTn/NmFc1kL+PgSDyUFkW/Vq68SbDb16b5Lg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=FSpsU1Ne2F1/FQpxdAyBVutgMoWjgKS5ECjra2lGB0egIKp4tXlnn/Nj4/zYB+dcu 96ysM/MsMfk8ZywwNQiExxk0JrAghS1P9MdINAPcBX1aL8E4mmaDSFp0AVPa6HOJ9y m/QAwjBqoGjCnnkY7CtQlb1dGedAsTKKNhVRCn8RDZWqkGkK0RwcIXAZPXrsKohhBd uzLYUVuOmuEJ4N6Q2rwvUeCit+fGMfEGSRxNh1drwmY5YKGSt6vZMMX4XdKUDIfcT5 fSIDkNZ92e66LaJEFyyrSd2Nsk8qIRTauRv54I5TKPUJsLLJmtQ9Dz7HtcxMah4Z6S 4dcD1xeBDvioQ== Date: Sat, 29 May 2021 14:10:16 -0700 From: Jakub Kicinski To: Justin Iurman Cc: netdev@vger.kernel.org, davem@davemloft.net, tom@herbertland.com Subject: Re: [PATCH net-next v4 0/5] Support for the IOAM Pre-allocated Trace with IPv6 Message-ID: <20210529141016.4015a396@kicinski-fedora-PC1C0HJN.hsd1.ca.comcast.net> In-Reply-To: <20210527151652.16074-1-justin.iurman@uliege.be> References: <20210527151652.16074-1-justin.iurman@uliege.be> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, 27 May 2021 17:16:47 +0200 Justin Iurman wrote: > In-situ Operations, Administration, and Maintenance (IOAM) records > operational and telemetry information in a packet while it traverses > a path between two points in an IOAM domain. It is defined in > draft-ietf-ippm-ioam-data [1]. IOAM data fields can be encapsulated > into a variety of protocols. The IPv6 encapsulation is defined in > draft-ietf-ippm-ioam-ipv6-options [2], via extension headers. IOAM > can be used to complement OAM mechanisms based on e.g. ICMP or other > types of probe packets. > > This patchset implements support for the Pre-allocated Trace, carried > by a Hop-by-Hop. Therefore, a new IPv6 Hop-by-Hop TLV option is > introduced, see IANA [3]. The three other IOAM options are not included > in this patchset (Incremental Trace, Proof-of-Transit and Edge-to-Edge). > The main idea behind the IOAM Pre-allocated Trace is that a node > pre-allocates some room in packets for IOAM data. Then, each IOAM node > on the path will insert its data. There exist several interesting use- > cases, e.g. Fast failure detection/isolation or Smart service selection. > Another killer use-case is what we have called Cross-Layer Telemetry, > see the demo video on its repository [4], that aims to make the entire > stack (L2/L3 -> L7) visible for distributed tracing tools (e.g. Jaeger), > instead of the current L5 -> L7 limited view. So, basically, this is a > nice feature for the Linux Kernel. Some coding comments from me. Please continue the discussion with David re: maturity of the RFC and make sure to CC him and Yoshifuji on next versions.