[PATCH net-next] vxlan: fix ethernet address initialization

[PATCH net-next] vxlan: fix ethernet address initialization

[Nicolas Dichtel]

Since commit 0c867c9bf84c, when the user specifies an ethernet address with
IFLA_ADDRESS, it's overridden by vxlan_ether_setup() (rtnl_link_ops->setup
is called in rtnetlink.c before handling IFLA_ADDRESS).

To test it:
ip link add name vxlan1 address de:ad:de:4c:0f:c2 type vxlan id 1 group 239.0.0.10 dev eth0

CC: Jiri Benc <jbenc@redhat.com>
Fixes: 0c867c9bf84c ("vxlan: move Ethernet initialization to a separate function")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
---
 drivers/net/vxlan.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 6fb93b57a724..d454c7e7d16e 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -2592,7 +2592,8 @@ static void vxlan_setup(struct net_device *dev)
 
 static void vxlan_ether_setup(struct net_device *dev)
 {
-	eth_hw_addr_random(dev);
+	if (!is_valid_ether_addr(dev->dev_addr))
+		eth_hw_addr_random(dev);
 	ether_setup(dev);
 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
-- 
2.4.2

Re: [PATCH net-next] vxlan: fix ethernet address initialization

[Jiri Benc]

On Thu, 28 Apr 2016 12:04:16 +0200, Nicolas Dichtel wrote:
> Since commit 0c867c9bf84c, when the user specifies an ethernet address with
> IFLA_ADDRESS, it's overridden by vxlan_ether_setup() (rtnl_link_ops->setup
> is called in rtnetlink.c before handling IFLA_ADDRESS).
> 
> To test it:
> ip link add name vxlan1 address de:ad:de:4c:0f:c2 type vxlan id 1 group 239.0.0.10 dev eth0

Good catch, Nicholas. I wrote a lnst recipe to test tons of
combinations of vxlan settings but did not think about including also
link parameters :-(

This affects not only IFLA_ADDRESS but also IFLA_MTU, IFLA_BROADCAST
and IFLA_TXQLEN. I'll try to solve all of these.

Thanks for catching this.

 Jiri

Re: [PATCH net-next] vxlan: fix ethernet address initialization

[Nicolas Dichtel]

Le 28/04/2016 12:04, Nicolas Dichtel a écrit :
> Since commit 0c867c9bf84c, when the user specifies an ethernet address with
> IFLA_ADDRESS, it's overridden by vxlan_ether_setup() (rtnl_link_ops->setup
> is called in rtnetlink.c before handling IFLA_ADDRESS).
> 
> To test it:
> ip link add name vxlan1 address de:ad:de:4c:0f:c2 type vxlan id 1 group 239.0.0.10 dev eth0
> 
> CC: Jiri Benc <jbenc@redhat.com>
> Fixes: 0c867c9bf84c ("vxlan: move Ethernet initialization to a separate function")
> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
David, please drop this patch. Jiri has sent a better fix.


Thank you,
Nicolas