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=-6.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS 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 54377C43381 for ; Mon, 25 Feb 2019 04:24:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 19E7D20989 for ; Mon, 25 Feb 2019 04:24:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Bn7yZnwT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726625AbfBYEYy (ORCPT ); Sun, 24 Feb 2019 23:24:54 -0500 Received: from mail-pl1-f196.google.com ([209.85.214.196]:42859 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726199AbfBYEYy (ORCPT ); Sun, 24 Feb 2019 23:24:54 -0500 Received: by mail-pl1-f196.google.com with SMTP id s1so3840013plp.9 for ; Sun, 24 Feb 2019 20:24:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=sAHDFMlHxrP8NtngQjs4m8olpQX04W1AxAGM+m6kL/8=; b=Bn7yZnwTpwYlZnPUZ8qQwjs/1ZBp1JxMj6uwdWr207uLIn2Vloc6Tryhixf9OOxdKl PK5LL43hSSrUBIU6SFz3Uqv3yU/VuAGwRXe+fpkXGT8NKL9zENgXhDyCM0qA6uZ43LKG AqD1zs34SKJ2I5VZ+UythuwxKYHGCg/sN6ssrIkzPKiKQLE0FdmBooUu6Swch/PWRo82 DKBUn+Wd75Qp8aF7Rn1V2Zp/Hs5t1O/1TmMulgL5ybUIANIHqjvb6AgaQbVy1m0OeG1e V2W0MT9/XNZdCpPKKkraQuBisIwsoi8QEwh1wnUwAuLe/TsQ5m4+A1WaE9OGL9pN9X37 cNEA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=sAHDFMlHxrP8NtngQjs4m8olpQX04W1AxAGM+m6kL/8=; b=UpS9BWGAw1nLqAyQkjAkCO65r6XxSHBUMOL1QqaLftAQcBhNIeb2z5++VWXlEOofbP rd6OnAlX6qqPz3kGaYUhbf4gbf6GtY23ozUtX6HzAxnAV1vRtmETgaYvSJraIeEPFqL0 nALdoBNBxOc69TQF4ubEKH9Jdv6/7QXKMSPIjaF6c6V5rec+1vF7xQ960SJz9Zi0Z2yM Jd9JlFDEv87WP/HaP9moCBXCDQHFA+nIGBz3/DrBR/IRpMzRPxaPNrqCVA6Q7jRxRsHo eAeZyL+5mPulsN/9fy/E/eVGImweaB9Xr+YeCXDVv5quDcc+2AnFTdDvbSRhp0y9RojX KPzQ== X-Gm-Message-State: AHQUAuapW4o9tnL/nMfafNvqHQZ1R7xTRo5/sC2cNoMozidKYb6O71Dz LKBq6dKsg6aCGI13BuDITw4= X-Google-Smtp-Source: AHgI3Ibe5uHC+A+U+6O/AFVug62PhC+1tclTURjBnWNNvdrVNmpOVKqPMC2Uc8428oHrgGGj4C3AhA== X-Received: by 2002:a17:902:64:: with SMTP id 91mr18729539pla.229.1551068693810; Sun, 24 Feb 2019 20:24:53 -0800 (PST) Received: from [192.168.86.235] (c-73-241-150-70.hsd1.ca.comcast.net. [73.241.150.70]) by smtp.gmail.com with ESMTPSA id z6sm11144539pgo.31.2019.02.24.20.24.52 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 24 Feb 2019 20:24:52 -0800 (PST) Subject: Re: [PATCH net] sit: use ipv6_mod_enabled to check if ipv6 is disabled To: Hangbin Liu , netdev@vger.kernel.org Cc: Stefano Brivio , "David S . Miller" , David Ahern References: <20190225041243.9753-1-liuhangbin@gmail.com> From: Eric Dumazet Message-ID: <7c0f5c9c-d918-de27-643d-416509576be4@gmail.com> Date: Sun, 24 Feb 2019 20:24:51 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20190225041243.9753-1-liuhangbin@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 02/24/2019 08:12 PM, Hangbin Liu wrote: > ipv6_mod_enabled() is more safe and gentle to check if ipv6 is disabled > at running time. > Why is it better exactly ? IPv6 can be enabled on the host, but disabled per device /proc/sys/net/ipv6/conf/{name}/disable_ipv6 > Fixes: 173656accaf5 ("sit: check if IPv6 enabled before calling ip6_err_gen_icmpv6_unreach()") > Signed-off-by: Hangbin Liu > --- > net/ipv6/sit.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c > index e8a1dabef803..eea1f19985a7 100644 > --- a/net/ipv6/sit.c > +++ b/net/ipv6/sit.c > @@ -546,7 +546,7 @@ static int ipip6_err(struct sk_buff *skb, u32 info) > } > > err = 0; > - if (__in6_dev_get(skb->dev) && > + if (ipv6_mod_enabled() && > !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len)) > goto out; > >