[lxc-devel] segfault with insufficient network config

[Daniel Lezcano]

On 07/22/2010 09:44 PM, Ferenc Wagner wrote:
> Hi,
>
> $ lxc-execute --name net -s lxc.network.type=phys bash
> Segmentation fault (core dumped)
>
> The problem is that the netdev structure is mostly uninitialized (only
> its type is set to LXC_NET_PHYS), so if_nametoindex() is invoked with a
> NULL argument:
>
> static int instanciate_phys(struct lxc_netdev *netdev)
> {
>          netdev->ifindex = if_nametoindex(netdev->link);
>
> That would be easy to fix by starting with
>
>          if (!netdev->link) {
>                  ERROR("no link specified for phy netdev");
>                  return -1;
>          }
>

Oops, right.

> or similar, but there's something else, too:
>
> # lxc-execute --name net -s lxc.network.type=phys -s lxc.network.link=eth0 bash
> lxc-execute: failed to move 'eth0' to the container : Message too long
>
> It might as well have some sense, but I definitely don't get it this
> late. :)  I give up now.

I think the error is wrong, perhaps the kernel is returning a wrong 
value or there is a bad error catch in lxc. But I think the problem may 
come from the kernel version < 2.6.35 because it does not support 
physical interface moving across namespace. Is it a kernel < 2.6.35 ?