From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vincent Bernat Subject: [net v3] veth: advertise peer link once both links are tied together Date: Mon, 30 May 2016 17:58:37 +0200 Message-ID: <1464623917-11536-1-git-send-email-vincent@bernat.im> References: <574C6095.9050804@6wind.com> Cc: Vincent Bernat To: "David S. Miller" , Vijay Pandurangan , Paolo Abeni , netdev@vger.kernel.org, Nicolas Dichtel Return-path: Received: from bart.luffy.cx ([78.47.78.131]:40362 "EHLO bart.luffy.cx" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161301AbcE3P6q (ORCPT ); Mon, 30 May 2016 11:58:46 -0400 In-Reply-To: <574C6095.9050804@6wind.com> Sender: netdev-owner@vger.kernel.org List-ID: When the peer link is created, its "iflink" information is not advertised through Netlink. Once created, the local device is advertised with this information but if a user is maintaining a cache from all updates, it will still miss the iflink for the peer link: 2: veth0@NONE: mtu 1500 qdisc noop state DOWN group default link/ether ae:0e:08:af:fb:a0 brd ff:ff:ff:ff:ff:ff 3: veth1@veth0: mtu 1500 qdisc noop state DOWN group default link/ether 3a:31:f1:36:2e:e5 brd ff:ff:ff:ff:ff:ff With this patch, we advertise again the peer link to let any user pick the appropriate iflink information: 3: veth0@NONE: mtu 1500 qdisc noop state DOWN group default link/ether fa:ba:12:26:99:00 brd ff:ff:ff:ff:ff:ff 3: veth0@veth1: mtu 1500 qdisc noop state DOWN group default link/ether fa:ba:12:26:99:00 brd ff:ff:ff:ff:ff:ff 4: veth1@veth0: mtu 1500 qdisc noop state DOWN group default link/ether ea:e4:e2:26:3c:87 brd ff:ff:ff:ff:ff:ff Signed-off-by: Vincent Bernat --- v3: - send an additional netlink messages once the peer link is tied to avoid any chicken/egg problem v2: - ensure the device is unregistered in case of link configuration failure drivers/net/veth.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/veth.c b/drivers/net/veth.c index f37a6e61d4ad..2376d17b8f53 100644 --- a/drivers/net/veth.c +++ b/drivers/net/veth.c @@ -466,6 +466,8 @@ static int veth_newlink(struct net *src_net, struct net_device *dev, priv = netdev_priv(peer); rcu_assign_pointer(priv->peer, dev); + + rtmsg_ifinfo(RTM_NEWLINK, peer, IFF_SLAVE, GFP_KERNEL); return 0; err_register_dev: -- 2.8.1