Re: [patch net] net: forbid netdev used by mirred tc act from being moved to another netns

Tue, Nov 14, 2017 at 06:51:42AM CET, xiyou.wangcong@gmail.com wrote:

On Mon, Nov 13, 2017 at 9:17 PM, Jiri Pirko [off-list ref] wrote:

quoted

Mon, Nov 13, 2017 at 08:53:57PM CET, xiyou.wangcong@gmail.com wrote:

quoted

On Mon, Nov 13, 2017 at 6:05 AM, Jiri Pirko [off-list ref] wrote:

quoted

From: Jiri Pirko <redacted>

Currently, user may choose to move device that is used by mirred action
to another network namespace. That is wrong as the action still remains
in the original namespace and references non-existing ifindex.

It is a pure display issue, the action itself should function well
because we only use ifindex to lookup netdevice once and
we save the netdevice pointer in action.

If you really want to fix it, just tell iprout2 to display netnsid together
with ifindex.

It is not only display issue. I think it is wrong to let a netdevice

What's wrong with it? Is it mis-functioning?

Nope.

quoted

dissapear from underneath the mirred action. You certainly cannot add an

It disappears only because we don't display it properly, nothing else.

Okay.

quoted

action mirred with device from another net namespace. So should we allow
that?

On the other hand why linking a device to mirred action prevents it
from moving to another netns? Also, device can be moved back too.

I don't see anything wrong with it except displaying it.

Okay. What about my question? Should we allow adding an action mirred
pointing to a netdev in another netns? I think it would make sense in
case we consider movement of mirred device legit.