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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 F212BC64EB8 for ; Thu, 4 Oct 2018 09:53:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AAE072098A for ; Thu, 4 Oct 2018 09:53:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="biJlksrc"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="AvCOeO+6" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AAE072098A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727845AbeJDQqW (ORCPT ); Thu, 4 Oct 2018 12:46:22 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:47420 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727369AbeJDQqW (ORCPT ); Thu, 4 Oct 2018 12:46:22 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 42C0860C86; Thu, 4 Oct 2018 09:53:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1538646833; bh=alRNw4uLZ2UGbKsmh6rMlj4pOiV6ckDyOJdfMdDVDG8=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=biJlksrcOVxU3bYgiwM4gi82mtDuxL5p7QbKz9Vcm1dJyGpU468qkO9nHqh6f0wPT tTMx0/0EuQcSYRtcP0R+P2I3aXwC8/tq7SQZYjGkpHydfWAWeIwkjGz8FORRS8DCER NY5KP9pu+EQMn4xP2aLHNIAEkujQuBxY2GJ3UD5w= Received: from x230.qca.qualcomm.com (85-76-114-39-nat.elisa-mobile.fi [85.76.114.39]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: kvalo@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 50C3F60C6A; Thu, 4 Oct 2018 09:53:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1538646832; bh=alRNw4uLZ2UGbKsmh6rMlj4pOiV6ckDyOJdfMdDVDG8=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=AvCOeO+6M8fnp5zb42FbrWz+GgkOsx5QXw+7JjPmk1U/8lo3P66kLMVBwkA0dXViE x/Rof3CCg8390/H+Zqwo7UX7Ohfn+3LiUY52tTlMov4wQ8InHO3LHuThARo9UOquR5 Q09fEyYYtaQD4OQ/03THco1BgWRO0T08JaqYMHBI= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 50C3F60C6A Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=kvalo@codeaurora.org From: Kalle Valo To: Vladis Dronov Cc: David Miller , kuznet@ms2.inr.ac.ru, yoshfuji@linux-ipv6.org, netdev@vger.kernel.org, syzkaller@googlegroups.com, linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org Subject: Re: [PATCH] net: arp, ipv6: handle special case of tap device References: <20180926093018.6646-1-vdronov@redhat.com> <20180929.114023.1370133506922372520.davem@davemloft.net> <1615981257.17285278.1538393552487.JavaMail.zimbra@redhat.com> <20181002.222540.1948082296309410659.davem@davemloft.net> <2058134821.17788321.1538573112620.JavaMail.zimbra@redhat.com> Date: Thu, 04 Oct 2018 12:53:46 +0300 In-Reply-To: <2058134821.17788321.1538573112620.JavaMail.zimbra@redhat.com> (Vladis Dronov's message of "Wed, 3 Oct 2018 09:25:12 -0400 (EDT)") Message-ID: <87muru2g2d.fsf@codeaurora.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Vladis Dronov writes: >> From: "David Miller" >> Sent: Wednesday, October 3, 2018 7:25:40 AM >> >> > Probably, this functionality is already used by some userspace, so I >> > believe, I cannot just remove TUNSETLINK ioctl. >> >> Who uses it, how do they use it, and what do they sanely expect about >> the link layer header properties of a tap device which has had ->type >> changed? > > Honestly, I have no idea. I was working on a syzkaller bug report and > found that the reason for that bug was TUNSETLINK ioctl. > > This ioctl was introduced 13 years ago with ff4cc3ac93e1d and it says: > >> For use with >> wireless and other networking types it should be possible to set the >> ARP type via an ioctl. > > , that's all. Let me try to prepare a patch that sets dev->addr_len and > dev->broadcast according to dev->type. I would probably need an advise > what other fields must be adjusted too. > > Otherwise, we can just to remove the TUNSETLINK ioctl. Let's add linux-wireless in case someone there knows about the ioctl. -- Kalle Valo