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=-3.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 63964C04AB6 for ; Sat, 1 Jun 2019 01:43:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2D2C126FDB for ; Sat, 1 Jun 2019 01:43:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="IVZ5ehzB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727003AbfFABn4 (ORCPT ); Fri, 31 May 2019 21:43:56 -0400 Received: from mail-lj1-f196.google.com ([209.85.208.196]:41844 "EHLO mail-lj1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726881AbfFABnz (ORCPT ); Fri, 31 May 2019 21:43:55 -0400 Received: by mail-lj1-f196.google.com with SMTP id s21so646035lji.8 for ; Fri, 31 May 2019 18:43:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Jlr9qLL9Vgy0gBgXQ4/IDkCeMqnCFC9akEvCKd6pcyk=; b=IVZ5ehzB6ICtTECBvev1+6YDAck4uWc1fNoix/YTnUZqH/f+EZ/+QzfGrUTUDdClhR 1KHV1xkvvlRHxORE8XZ2B55j3aYNSi+nU7sf2SYlOVVn1g7zyimhWIwMdKHEufwqcYp/ dEhzv92KcAA1bg53LMIWyNfSAYz2QMto+1hW9OE/TTjbXZEJCuvWP+YNJsEBOpxlWQew +bSYcSWzdi0qFF0n7/GVAt9AjPfvkk1zKgB6A10GoAFZijkFL1uCWGCAZmtRw5239rC0 WsbaKlX0nu3M545pgNlE1qm8mvbUKmYyrcPsC78j4EFKJKvyw4IOxt/9LZ0t3kWxg0of Lo3g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Jlr9qLL9Vgy0gBgXQ4/IDkCeMqnCFC9akEvCKd6pcyk=; b=LnZmVpDovMEOoQK3Huslv7dHY5L19HKzDhEzfvX/ds7lI0QJ31MAx8WHCilzXJWLj5 vuE1gNA9AvO5MMJX7/QwYMn/NwYNV4Ok5JPxfNKGCv3T4oUgQ55iOX3ozTMY4mI4maaM SUp3h84ow7oBRr/jO01qtBs/6Kb14d34LHyrrmoiOUNI8tSSr/RjTU3JO5cEqYAb7TSJ O5oP3JOx9TViDmlIFIqYtklhKSsa8BvxEL+5XbD26XH2GwxTEdKe+NuKNrxit6wanVnR umtbryO5zXIGiVKrO4j3IPhmgwkXKNqgdnpnC7xFaX+3zaZFbsJxYDIXWYONojJKUrL/ zTTA== X-Gm-Message-State: APjAAAXdljKsGyDMkbKUWjiwG98/Wv/dHXBbwT3VtWyXfXglwARujIb1 pCBNIf1WgPK108ZaJybzyCyrS5w6IRGdshJlO3k= X-Google-Smtp-Source: APXvYqzlsf//pVpSmUOSuwFVmk1vYklv7DGK8tKh4y+ea4A5HdMzHgSdhRBlInwGpO5rJCz6ns2PXqPY6cs0leugv80= X-Received: by 2002:a2e:5b52:: with SMTP id p79mr7652647ljb.208.1559353433988; Fri, 31 May 2019 18:43:53 -0700 (PDT) MIME-Version: 1.0 References: <20190507091118.24324-1-liuhangbin@gmail.com> <20190508.093541.1274244477886053907.davem@davemloft.net> In-Reply-To: <20190508.093541.1274244477886053907.davem@davemloft.net> From: =?UTF-8?Q?Maciej_=C5=BBenczykowski?= Date: Fri, 31 May 2019 18:43:42 -0700 Message-ID: Subject: Re: [PATCH net] fib_rules: return 0 directly if an exactly same rule exists when NLM_F_EXCL not supplied To: David Miller , Lorenzo Colitti , astrachan@google.com, Greg KH Cc: liuhangbin@gmail.com, Linux NetDev , mateusz.bajorski@nokia.com, dsa@cumulusnetworks.com Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org FYI, this userspace visible change in behaviour breaks Android. We rely on being able to add a rule and either have a dup be created (in which case we'll remove it later) or have it fail with EEXIST (in which case we won't remove it later). Returning 0 makes atomically changing a rule difficult. Please revert. On Wed, May 8, 2019 at 9:39 AM David Miller wrote: > > From: Hangbin Liu > Date: Tue, 7 May 2019 17:11:18 +0800 > > > With commit 153380ec4b9 ("fib_rules: Added NLM_F_EXCL support to > > fib_nl_newrule") we now able to check if a rule already exists. But this > > only works with iproute2. For other tools like libnl, NetworkManager, > > it still could add duplicate rules with only NLM_F_CREATE flag, like > > > > [localhost ~ ]# ip rule > > 0: from all lookup local > > 32766: from all lookup main > > 32767: from all lookup default > > 100000: from 192.168.7.5 lookup 5 > > 100000: from 192.168.7.5 lookup 5 > > > > As it doesn't make sense to create two duplicate rules, let's just return > > 0 if the rule exists. > > > > Fixes: 153380ec4b9 ("fib_rules: Added NLM_F_EXCL support to fib_nl_newrule") > > Reported-by: Thomas Haller > > Signed-off-by: Hangbin Liu > > Applied and queued up for -stable, thanks.