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 58C55C6FA99 for ; Sat, 11 Mar 2023 01:13:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229770AbjCKBNE (ORCPT ); Fri, 10 Mar 2023 20:13:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54952 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229589AbjCKBNC (ORCPT ); Fri, 10 Mar 2023 20:13:02 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0D77D13D54 for ; Fri, 10 Mar 2023 17:13:00 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8433061D98 for ; Sat, 11 Mar 2023 01:12:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8151AC433EF; Sat, 11 Mar 2023 01:12:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1678497178; bh=zMATmf0SHnFWoUlLo2Duy7kzf4PheKK/a7Ljm1Jx6d8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=jyOZ9urMlTIWvquUvq/3d7/YNQzqZKDed/lbBYeFEwR8P02MkyA6iUJBOGaO2twRd HXY+mnKuYFgU4tY8/pPUuPp21J+eImtL4ZtS5eEMkFvqMWutPWIqmlG03HtL+9NaNT nJxuRScL3+vD6DUDRwtzeJzXOBKnFaNYj5uM8GE+5AY4pqGmEe4oiWOfXHdutlsMIs rcj3bLY8oqvJUVZXiX8Ke10s3em3EqbvgxRVSjVz2BiTZa21Zp4LaNiQLTm2wavh0L O29z3oUKvS6TlI8ingrzfEiM/LaD81nb3PSqiB2+teUNWN02xUJ4p/R50D+3n3Bqsi Q/PrQByNDtpew== Date: Fri, 10 Mar 2023 17:12:57 -0800 From: Jakub Kicinski To: Petr Machata Cc: "David S. Miller" , Eric Dumazet , Paolo Abeni , , David Ahern , Shuah Khan , "Ido Schimmel" , Subject: Re: [PATCH net-next 0/5] net: Extend address label support Message-ID: <20230310171257.0127e74c@kernel.org> In-Reply-To: References: 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 Fri, 10 Mar 2023 12:44:53 +0100 Petr Machata wrote: > IPv4 addresses can be tagged with label strings. Unlike IPv6 addrlabels, > which are used for prioritization of IPv6 addresses, these "ip address > labels" are simply tags that the userspace can assign to IP addresses > arbitrarily. > > IPv4 has had support for these tags since before Linux was tracked in GIT. > However it has never been possible to change the label after it is once > defined. This limits usefulness of this feature. A userspace that wants to > change a label might drop and recreate the address, but that disrupts > routing and is just impractical. > > IPv6 addresses lack support for address labels (in the sense of address > tags) altogether. > > In this patchset, extend IPv4 to allow changing the label defined at an > address (in patch #1). Then, in patches #2 and #3, extend IPv6 with a suite > of address label operations fully analogous with those defined for IPv4. > Then in patches #4 and #5 add selftest coverage for the feature. Feels a bit like we're missing motivation for this change. I thought address labels were legacy cruft. Also the usual concern about allowing to change things is that some user space will assume it's immutable. The label could until this set be used as part of a stable key, right?