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

[David Miller]

From: David Ahern 
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 

Applied, thanks David.

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

[Greg Rose]

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 
> ---
>  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