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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham 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 4C1FAC169C4 for ; Fri, 8 Feb 2019 10:41:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 15FFB20863 for ; Fri, 8 Feb 2019 10:41:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727694AbfBHKlA (ORCPT ); Fri, 8 Feb 2019 05:41:00 -0500 Received: from orbyte.nwl.cc ([151.80.46.58]:45062 "EHLO orbyte.nwl.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726081AbfBHKk7 (ORCPT ); Fri, 8 Feb 2019 05:40:59 -0500 Received: from n0-1 by orbyte.nwl.cc with local (Exim 4.91) (envelope-from ) id 1gs3ab-0005oj-Ob; Fri, 08 Feb 2019 11:40:57 +0100 Date: Fri, 8 Feb 2019 11:40:57 +0100 From: Phil Sutter To: Stephen Hemminger Cc: netdev@vger.kernel.org, Roopa Prabhu Subject: Re: [iproute PATCH] ip-link: Fix listing of alias interfaces Message-ID: <20190208104057.GE26388@orbyte.nwl.cc> Mail-Followup-To: Phil Sutter , Stephen Hemminger , netdev@vger.kernel.org, Roopa Prabhu References: <20190207130527.9439-1-phil@nwl.cc> <20190207162436.4452f7ad@hermes.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190207162436.4452f7ad@hermes.lan> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Feb 07, 2019 at 04:24:36PM -0800, Stephen Hemminger wrote: > On Thu, 7 Feb 2019 14:05:27 +0100 > Phil Sutter wrote: > > > Commit 50b9950dd9011 ("link dump filter") accidentally broke listing of > > links in the old alias interface notation: > > > > | % ip link show eth0:1 > > | RTNETLINK answers: No such device > > | Cannot send link get request: No such device > > > > Prior to the above commit, link lookup was performed via ifindex > > returned by if_nametoindex(). The latter uses SIOCGIFINDEX ioctl call > > which on kernel side causes the colon-suffix to be dropped before doing > > the interface lookup. Netlink API though doesn't care about that at all. > > To keep things backward compatible, mimick ioctl API behaviour and drop > > the colon-suffix prior to sending the RTM_GETLINK request. > > > > Fixes: 50b9950dd9011 ("link dump filter") > > Signed-off-by: Phil Sutter > > What about mistaken usage where the text after the colon is not a number, > or has additional colon? That's completely ignored in ioctl-case as well. See dev_ioctl() in kernel sources: | colon = strchr(ifr->ifr_name, ':'); | if (colon) | *colon = 0; If you pass 'group 0' to link show command, ioctl code path is taken. It allows (and drops) arbitrary input after the colon (as long as the total name doesn't exceed 15 characters). Cheers, Phil