Re: [PATCH net-next 4/4] rtnetlink: promote IFLA_VF_STATS to same level as IFLA_VF_INFO

On Fri, 22 Jan 2021 20:53:21 -0800 Edwin Peer wrote:

Separating the VF stats out of IFLA_VF_INFO appears to be the least
impact way of resolving the nlattr overflow bug in IFLA_VFINFO_LIST.

Since changing the hierarchy does constitute an ABI change, it must
be explicitly requested via RTEXT_FILTER_VF_SEPARATE_STATS. Otherwise,
the old location is maintained for compatibility.

We don't want any additions to the VF ABI via GETLINK. IMO the clear
truncation is fine, hiding stats is pushing it, new attr is a no go.

A new container type, namely IFLA_VFSTATS_LIST, is introduced to group
the stats objects into an ordered list that corresponds with the order
of VFs in IFLA_VFINFO_LIST.