Re: [RFC 0/3] netlink: extended error reporting

[David Miller <davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>]

From: Johannes Berg <johannes-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
Date: Fri,  7 Apr 2017 20:26:17 +0200

> So this is my first draft of what we'd talked about at netconf.
> I'm not super happy with the way we have to pass the extended
> error struct, but I don't see a way to implement reporting any
> dynamic information (like error offsets) in any other way.
> 
> Alexander Shishkin had a nice way of reporting static extended
> error data, but that isn't really suitable for reporting the
> offset or even reporting the broken attribute from nla_parse().
> 
> Speaking of nla_parse(), that'll be somewhat complicated to do
> since we'll have to track the offsets of where we're parsing,
> but it might be possible since the nlattrs are just pointers
> into the message, so (optionally?) passing the skb as well can
> allow us to fill the offset information.

I like it, nice work.

I know people want dynamically generated strings and stuff, and we can
get there, but I prefer that the first thing we commit is super simple.

Someone gave me a hard time about the fact that we've been talking
about this idea for years but nothing ever happens.

I'm tempted to apply this as-is just to show that person that things
do in fact happen.... eventually :-)