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[net-next] net: vrf: Do not allow looback to be moved to a VRF

Message ID 1493218702-10906-1-git-send-email-dsa@cumulusnetworks.com
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

David Ahern April 26, 2017, 2:58 p.m. UTC
Moving the loopback into a VRF breaks networking for the default VRF.
Since the VRF device is the loopback for VRF domains, there is no
reason to move the loopback. Given the repercussions, block attempts
to set lo into a VRF.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
---
 drivers/net/vrf.c | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

Gregory Rose April 27, 2017, 2:44 a.m. UTC | #1
On Wed, 2017-04-26 at 07:58 -0700, David Ahern wrote:
> Moving the loopback into a VRF breaks networking for the default VRF.
> Since the VRF device is the loopback for VRF domains, there is no
> reason to move the loopback. Given the repercussions, block attempts
> to set lo into a VRF.
> 
> Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
> ---
>  drivers/net/vrf.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
> index aa5d30428bba..ceda5861da78 100644
> --- a/drivers/net/vrf.c
> +++ b/drivers/net/vrf.c
> @@ -877,6 +877,12 @@ static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
>  {
>  	int ret;
>  
> +	/* do not allow loopback device to be enslaved to a VRF.
> +	 * The vrf device acts as the loopback for the vrf.
> +	 */
> +	if (port_dev == dev_net(dev)->loopback_dev)
> +		return -EOPNOTSUPP;
> +
>  	port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
>  	ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL);
>  	if (ret < 0)

I think that's a great idea.

Reviewed-by: Greg Rose <gvrose8192@gmail.com>
David Miller April 27, 2017, 8:50 p.m. UTC | #2
From: David Ahern <dsa@cumulusnetworks.com>
Date: Wed, 26 Apr 2017 07:58:22 -0700

> Moving the loopback into a VRF breaks networking for the default VRF.
> Since the VRF device is the loopback for VRF domains, there is no
> reason to move the loopback. Given the repercussions, block attempts
> to set lo into a VRF.
> 
> Signed-off-by: David Ahern <dsa@cumulusnetworks.com>

Applied, thanks David.
diff mbox

Patch

diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index aa5d30428bba..ceda5861da78 100644
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -877,6 +877,12 @@  static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
 {
 	int ret;
 
+	/* do not allow loopback device to be enslaved to a VRF.
+	 * The vrf device acts as the loopback for the vrf.
+	 */
+	if (port_dev == dev_net(dev)->loopback_dev)
+		return -EOPNOTSUPP;
+
 	port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
 	ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL);
 	if (ret < 0)