From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754929Ab3HAKlw (ORCPT ); Thu, 1 Aug 2013 06:41:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:12073 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753884Ab3HAKlv (ORCPT ); Thu, 1 Aug 2013 06:41:51 -0400 Date: Thu, 1 Aug 2013 13:43:19 +0300 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Cc: Patrick McHardy , "David S. Miller" , Eric Dumazet , Jiri Pirko , netdev@vger.kernel.org Subject: [PATCH] macvlan: better mode validation Message-ID: <20130801104319.GA7127@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org macvlan passthrough mode is special: it's not possible to switch to or from it through a netlink command. But if you try, the command will succeed, which is confusing. Validate input and return error to user. Cc: Sridhar Samudrala Cc: "David S. Miller" Signed-off-by: Michael S. Tsirkin --- drivers/net/macvlan.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c index 18373b6..13937f9 100644 --- a/drivers/net/macvlan.c +++ b/drivers/net/macvlan.c @@ -863,6 +863,18 @@ static int macvlan_changelink(struct net_device *dev, struct nlattr *tb[], struct nlattr *data[]) { struct macvlan_dev *vlan = netdev_priv(dev); + enum macvlan_mode mode; + bool set_mode = false; + + /* Validate mode, but don't set yet: setting flags may fail. */ + if (data && data[IFLA_MACVLAN_MODE]) { + set_mode = true; + mode = nla_get_u32(data[IFLA_MACVLAN_MODE]); + /* Passthrough mode can't be set or cleared dynamically */ + if ((mode == MACVLAN_MODE_PASSTHRU) != + (vlan->mode == MACVLAN_MODE_PASSTHRU)) + return -EINVAL; + } if (data && data[IFLA_MACVLAN_FLAGS]) { __u16 flags = nla_get_u16(data[IFLA_MACVLAN_FLAGS]); @@ -879,8 +891,8 @@ static int macvlan_changelink(struct net_device *dev, } vlan->flags = flags; } - if (data && data[IFLA_MACVLAN_MODE]) - vlan->mode = nla_get_u32(data[IFLA_MACVLAN_MODE]); + if (set_mode) + vlan->mode = mode; return 0; } -- MST