| Message ID | 1464623917-11536-1-git-send-email-vincent@bernat.im |
|---|---|
| State | Superseded, archived |
| Delegated to: | David Miller |
| Headers | show |
❦ 30 mai 2016 17:58 CEST, Vincent Bernat <vincent@bernat.im> : > + > + rtmsg_ifinfo(RTM_NEWLINK, peer, IFF_SLAVE, GFP_KERNEL); Maybe ~0U would be better than hijacking IFF_SLAVE?
Le 30/05/2016 18:01, Vincent Bernat a écrit : > ❦ 30 mai 2016 17:58 CEST, Vincent Bernat <vincent@bernat.im> : > >> + >> + rtmsg_ifinfo(RTM_NEWLINK, peer, IFF_SLAVE, GFP_KERNEL); > > Maybe ~0U would be better than hijacking IFF_SLAVE? IFF_SLAVE is wrong. It's a flag here, that will be put in the ifi_change field not an attribute number.
❦ 30 mai 2016 18:27 CEST, Nicolas Dichtel <nicolas.dichtel@6wind.com> : >>> + >>> + rtmsg_ifinfo(RTM_NEWLINK, peer, IFF_SLAVE, GFP_KERNEL); >> >> Maybe ~0U would be better than hijacking IFF_SLAVE? > IFF_SLAVE is wrong. It's a flag here, that will be put in the ifi_change field > not an attribute number. There are some use of IFF_SLAVE (in bonding/bond_main.c). But, I'll update the patch nonetheless.
Le 31/05/2016 08:29, Vincent Bernat a écrit : > ❦ 30 mai 2016 18:27 CEST, Nicolas Dichtel <nicolas.dichtel@6wind.com> : > >>>> + >>>> + rtmsg_ifinfo(RTM_NEWLINK, peer, IFF_SLAVE, GFP_KERNEL); >>> >>> Maybe ~0U would be better than hijacking IFF_SLAVE? >> IFF_SLAVE is wrong. It's a flag here, that will be put in the ifi_change field >> not an attribute number. > > There are some use of IFF_SLAVE (in bonding/bond_main.c). But, I'll > update the patch nonetheless. Sorry, I read it too quickly, IFF_SLAVE is a flag, not an attribute. But this field indicates to the userland which flags has changed and this flag does not change here ;-)
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:
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: <BROADCAST,MULTICAST> 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: <BROADCAST,MULTICAST,M-DOWN> 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: <BROADCAST,MULTICAST> 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: <BROADCAST,MULTICAST> 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: <BROADCAST,MULTICAST,M-DOWN> 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 <vincent@bernat.im> --- 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(+)