On Tue, 2016-04-19 at 14:23 -0400, David Miller wrote: > > I like this nlattr flag idea, it's opt-in and any tool can be updated > to use the new facility.
Right. > I'd be willing the backport the nlattr flag bit change to all stable > releases as well. I'm not really convinced that helps much - tools still can't really rely on the kernel supporting it. One thing that might work is that a tool might say it only wants to support kernels that have this change (assuming we backport it to enough kernels etc.); in that case the tool could add some absolutely must-have information (like the IFINDEX or whatever, depends on the command) with the new flag, this would get rejected since unpatched kernels wouldn't understand the flag and wouldn't find that must-have information. Nevertheless, I think it's most reliable with new netlink commands that are known to be available only on kernels understand and treating the flag correctly. johannes
