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=-7.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 54F85C433ED for ; Fri, 2 Apr 2021 17:00:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 22CB0610FC for ; Fri, 2 Apr 2021 17:00:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235120AbhDBRAX (ORCPT ); Fri, 2 Apr 2021 13:00:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50574 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229722AbhDBRAV (ORCPT ); Fri, 2 Apr 2021 13:00:21 -0400 Received: from mail-pj1-x102a.google.com (mail-pj1-x102a.google.com [IPv6:2607:f8b0:4864:20::102a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 88009C0613E6 for ; Fri, 2 Apr 2021 10:00:20 -0700 (PDT) Received: by mail-pj1-x102a.google.com with SMTP id gv19-20020a17090b11d3b029014c516f4eb5so1041268pjb.0 for ; Fri, 02 Apr 2021 10:00:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=mjhdWdxhulnEwCie232G/07GzPUc1kE9v9ZDq5mv/CA=; b=rk7pH6eUkvyXSZkzYoflb1ndht4LSToY+3jL01kky3thWVEfOUkyVilNN0HjPpclRj 68u47ztcPLK3R2UKox1cSRnFBHfS1RGrdXW+845jzBSwhOgcCKzsICeAEg4AwqhknWQh zwmPysHbITpGGCP6UZ76/1u8J04W0Pbmr+t7n/CTuU0Bny26UyFPwtw/G+/CAItrvt6T a765bcMujV4bqMFrtkPzwJfk+Qc2CC1HphFkD7IlM4oA1c9Cd69B95gg/Vx63vz3aBb2 xTnsSDNLJzTBcefyDes0PqxcfCdsk/oF9wWardw+DO99ceQqx7XjMMBgUVh9YrqB2VaH OFrQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=mjhdWdxhulnEwCie232G/07GzPUc1kE9v9ZDq5mv/CA=; b=kTgXgcKy7GWnM8dxqlGLtegWysrHm+krUvVF99Flqo6K67MXalEq+jgBbGmM9VGi7m oiRl5P1QofGeBPcJ7QWaynJnesYvHF3tcWff+syWQcmjdtmqzOC3TUcUqbr0TcL5l9fv meaQG1STBbFGZExVbo7ZJ+emg0pu5pXpWJLyk7F1ehCKW/F7uA6mdp+Z3oBupFVBIUyP VNiIlBb1WW9TGK3BGJ+7ecAwqc2c5bunKdJbkzcdvzQUPKSkFzD9bDFgfyAyQ78AN5tR RMw8f+YjfqrU2+6oK7PtMd7prp7QWSkpNRPQEj/YO3SBKkpiYbpvGNps3HZ5hYCrKpe7 eFJA== X-Gm-Message-State: AOAM53067x3yKu1GMhajaOSnZN3L+GobpiXWrwExv65DrLTHUzZ6Y6Zp bIoGRnLSUxKmS2/unrQdjE0= X-Google-Smtp-Source: ABdhPJxpRcZ9L2nhteb2vnf0u0vkZhhZ1FPXYsBOpIrGbCeNlnO8D983RiR708DYz49sm80/eer7Sw== X-Received: by 2002:a17:902:9b8a:b029:e6:17bb:eff0 with SMTP id y10-20020a1709029b8ab02900e617bbeff0mr13522569plp.54.1617382817401; Fri, 02 Apr 2021 10:00:17 -0700 (PDT) Received: from gmail.com ([2601:600:8500:5f14:d627:c51e:516e:a105]) by smtp.gmail.com with ESMTPSA id o1sm8773716pjp.4.2021.04.02.10.00.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 02 Apr 2021 10:00:16 -0700 (PDT) Date: Fri, 2 Apr 2021 09:57:52 -0700 From: Andrei Vagin To: Christian Brauner Cc: "David S. Miller" , Jakub Kicinski , netdev@vger.kernel.org, Alexander Mikhalitsyn Subject: Re: [PATCH net-next] net: Allow to specify ifindex when device is moved to another namespace Message-ID: References: <20210402073622.1260310-1-avagin@gmail.com> <20210402082014.y6efckcpx3y7heo6@wittgenstein> MIME-Version: 1.0 Content-Type: text/plain; charset=koi8-r Content-Disposition: inline In-Reply-To: <20210402082014.y6efckcpx3y7heo6@wittgenstein> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Fri, Apr 02, 2021 at 10:20:14AM +0200, Christian Brauner wrote: > > @@ -11043,6 +11046,11 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char > > goto out; > > } > > > > + /* Check that new_ifindex isn't used yet. */ > > + err = -EBUSY; > > + if (new_ifindex && __dev_get_by_index(net, new_ifindex)) > > + goto out; > > Should this maybe verify that the new_inindex isn't negative and reject > it right away? (Maybe also right where we first retrieve it?) Otherwise > __dev_get_by_index() might pointlessly walk the whole netdev list for > thet network namespace. > I think __dev_get_by_index works fine for links with negative ifindices, but there are other places where we expect that ifindex is positive, so I think you are right, we need to check that it isn't negative here and we need to add the same check in register_netdevice too. Thanks, Andrei