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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 06027C43381 for ; Wed, 20 Mar 2019 09:16:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CB8F82184D for ; Wed, 20 Mar 2019 09:16:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726860AbfCTJQy (ORCPT ); Wed, 20 Mar 2019 05:16:54 -0400 Received: from relay.sw.ru ([185.231.240.75]:51590 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726595AbfCTJQy (ORCPT ); Wed, 20 Mar 2019 05:16:54 -0400 Received: from [172.16.25.169] (helo=localhost.localdomain) by relay.sw.ru with esmtp (Exim 4.91) (envelope-from ) id 1h6XL2-00076A-II; Wed, 20 Mar 2019 12:16:44 +0300 Subject: [PATCH 1/2] tun: Add ioctl() TUNGETDEVNETNS cmd to allow obtaining real net ns of tun device From: Kirill Tkhai To: netdev@vger.kernel.org Cc: davem@davemloft.net, harald.albrecht@gmx.net, jasowang@redhat.com, brouer@redhat.com, edumazet@google.com, mst@redhat.com, nicolas.dichtel@6wind.com, wangli39@baidu.com, ktkhai@virtuozzo.com Date: Wed, 20 Mar 2019 12:16:42 +0300 Message-ID: <155307337803.17673.7357500798893442953.stgit@localhost.localdomain> User-Agent: StGit/0.18 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org In commit f2780d6d7475 "tun: Add ioctl() SIOCGSKNS cmd to allow obtaining net ns of tun device" it was missed that tun may change its net ns, while net ns of socket remains the same as it was created initially. SIOCGSKNS returns net ns of socket, so it is not suitable for obtaining net ns of device. We may have two tun devices with the same names in two net ns, and in this case it's not possible to determ, which of them fd refers to (TUNGETIFF will return the same name). This patch adds new ioctl() cmd for obtaining net ns of a device. Reported-by: Harald Albrecht Signed-off-by: Kirill Tkhai --- drivers/net/tun.c | 8 ++++++++ include/uapi/linux/if_tun.h | 1 + 2 files changed, 9 insertions(+) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index e9ca1c088d0b..b7137edff624 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -3103,6 +3103,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd); + net = dev_net(tun->dev); ret = 0; switch (cmd) { case TUNGETIFF: @@ -3328,6 +3329,13 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, ret = tun_net_change_carrier(tun->dev, (bool)carrier); break; + case TUNGETDEVNETNS: + ret = -EPERM; + if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) + goto unlock; + ret = open_related_ns(&net->ns, get_net_ns); + break; + default: ret = -EINVAL; break; diff --git a/include/uapi/linux/if_tun.h b/include/uapi/linux/if_tun.h index 23a6753b37df..454ae31b93c7 100644 --- a/include/uapi/linux/if_tun.h +++ b/include/uapi/linux/if_tun.h @@ -60,6 +60,7 @@ #define TUNSETSTEERINGEBPF _IOR('T', 224, int) #define TUNSETFILTEREBPF _IOR('T', 225, int) #define TUNSETCARRIER _IOW('T', 226, int) +#define TUNGETDEVNETNS _IO('T', 227) /* TUNSETIFF ifr flags */ #define IFF_TUN 0x0001