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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 97A69C77B75 for ; Fri, 5 May 2023 16:59:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230055AbjEEQ7h (ORCPT ); Fri, 5 May 2023 12:59:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45794 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229717AbjEEQ7g (ORCPT ); Fri, 5 May 2023 12:59:36 -0400 Received: from mail-pf1-x432.google.com (mail-pf1-x432.google.com [IPv6:2607:f8b0:4864:20::432]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 841C330EE for ; Fri, 5 May 2023 09:59:35 -0700 (PDT) Received: by mail-pf1-x432.google.com with SMTP id d2e1a72fcca58-64389a44895so1750540b3a.1 for ; Fri, 05 May 2023 09:59:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20221208.gappssmtp.com; s=20221208; t=1683305975; x=1685897975; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=TAdX7eg2ryjY56yRTcHERosjHmSEk4LPOkzOv4IolK4=; b=bMx0T2PEF73qajo+15koX2YRbehw38va851NXwnFtJ+mx7MFBGachyQS2rCSICBrJD nKl3fDRQ6PZZDEISPPiQZSRzx4rCQzf/9u6ObKtD99AUSrcE4OU8Vj3SvaXrc1Zpi59B UV63xHiILreJPwcB+0X2kpT7RwwK9XRo7b5AkpqRuRy3XspTbIVhbzCLZgFvamWVn2fL H+BHrFUyixTE6Zdvitgjhunz5DILR+NuAYE7b4iXO+wUA/9SVOhZ406miG+13lhozflK 69B6dLb2TbWAICKHUngAXvDN+oZP9xOvotR9ROA2y7V/IGbBS1i7UNa/z2iTCPVGWiea 529A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683305975; x=1685897975; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=TAdX7eg2ryjY56yRTcHERosjHmSEk4LPOkzOv4IolK4=; b=A2ZUuJTo5uaj+87nmOJLDhPURVtGujQP4xwAEPxnCi5haOz1Qnc6o3vq8mw5fSWwvv LRL0BHOzFDLpCbNIryt6kvvtA7LmNQjgOeK6cZsVbOCUisPE9ErkySWbQMAY/7191t3/ z9q/ItCJaoVY2V6FwbxwiVmyL8S63oTD9bY/hjZ4E6WIut5JAfGR0qi5IUv6Si5397Ll BwWiLnmrQr4ZHRJB+Bkv7Yt/9mlOeflyq4LwpFU9A2nrohp4JXTI6F7lRQxmgPeFo/It vAyXI2/OldXF5ZZ7mRQ205O0wOUzArvwkAl+OkpTVU8gt9ivYJTFfRDPiFzBz0/5rF/P ppzQ== X-Gm-Message-State: AC+VfDwMJgUnqOsIDIHJRpjaLc3jIZ+6XMsynW4v5KmYG3uf76REzW9+ vPZMlA9nLSah3U+aEaov5V2YiZU5Qb5rP/tjj+3rCA== X-Google-Smtp-Source: ACHHUZ6FUzTYBCIMDTxJQxEa7xuKlQSBcvVlbcrDNPig9DMVntIYVrpgeqpY9QAuZ9kNhIc+Tjh/BQ== X-Received: by 2002:a05:6a20:4305:b0:f0:219e:f11c with SMTP id h5-20020a056a20430500b000f0219ef11cmr2887725pzk.31.1683305975026; Fri, 05 May 2023 09:59:35 -0700 (PDT) Received: from hermes.local (204-195-120-218.wavecable.com. [204.195.120.218]) by smtp.gmail.com with ESMTPSA id c25-20020aa78819000000b0064394d63458sm1871685pfo.78.2023.05.05.09.59.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 05 May 2023 09:59:34 -0700 (PDT) Date: Fri, 5 May 2023 09:59:32 -0700 From: Stephen Hemminger To: Chuck Lever Cc: netdev@vger.kernel.org, linux-rdma@vger.kernel.org, BMT@zurich.ibm.com, tom@talpey.com Subject: Re: [PATCH RFC 1/3] net/tun: Ensure tun devices have a MAC address Message-ID: <20230505095932.4025d469@hermes.local> In-Reply-To: <168330132769.5953.7109360341846745035.stgit@oracle-102.nfsv4bat.org> References: <168330051600.5953.11366152375575299483.stgit@oracle-102.nfsv4bat.org> <168330132769.5953.7109360341846745035.stgit@oracle-102.nfsv4bat.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On Fri, 05 May 2023 11:42:17 -0400 Chuck Lever wrote: > From: Chuck Lever > > A non-zero MAC address enables a network device to be assigned as > the underlying device for a virtual RDMA device. Without a non- > zero MAC address, cma_acquire_dev_by_src_ip() is unable to find the > underlying egress device that corresponds to a source IP address, > and rdma_resolve_address() fails. > > Signed-off-by: Chuck Lever > --- > drivers/net/tun.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/net/tun.c b/drivers/net/tun.c > index d4d0a41a905a..da85abfcd254 100644 > --- a/drivers/net/tun.c > +++ b/drivers/net/tun.c > @@ -1384,7 +1384,7 @@ static void tun_net_initialize(struct net_device *dev) > > /* Point-to-Point TUN Device */ > dev->hard_header_len = 0; > - dev->addr_len = 0; > + dev->addr_len = ETH_ALEN; > dev->mtu = 1500; > > /* Zero header length */ This is a bad idea. TUN devices are L3 devices without any MAC address. This patch will change the semantics and break users. If you want an L2 address, you need to use TAP, not TUN device.