Re: [PATCH] veth: replace iflink by a dedicated symlink in sysfs

Le 19/08/2015 14:48, Vincent Bernat a écrit :

  ❦ 19 août 2015 14:38 +0200, Jiri Benc [off-list ref] :

quoted

quoted

That's the main goal of this patch: advertising the peer link as
IFLA_LINK attribute triggers an infinite loop in userland software when
they follow iflink to discover network devices topology. iflink has
always been the index of a lower device. If a sysfs symbolic link is not
good enough, I can propose a new IFLA_PEER attribute instead.

This would cause regression and break applications for those of us who
started relying on the netnsid feature to match interfaces across net
name spaces.

Yes. Unfortunately.

quoted

This is tough. If you're going to do such thing, you would at least
need to also introduce IFLA_PEER_NETNSID.

Probably better to introduce veth netlink attribute then, something like
IFLA_VETH_PEER and keeps IFLA_LINK_NETNSID.

Yes I can.

In my opinion, the change of semantics of IFLA_LINK is a break of
API. However, I can live with it since it's easy to workaround it. It
just seemed easier to start the discussion with a patch.

I also don't know what is the best way to handle this. veth advertises
its peer via IFLA_LINK since 4.1, so it's too late to change it for this
release.