Subject: Re: [PATCH net-next 1/4] netlink: truncate overlength attribute list in nla_nest_end()

From: Jakub Kicinski <[email-masked]>
Date: Tue, 6 Jun 2023 09:17:06 -0700

On Tue, 6 Jun 2023 11:01:14 +0300 Gal Pressman wrote:
> On 05/06/2023 22:27, Edwin Peer wrote:
> > Thanks for the CC, I left Broadcom quite some time ago and am no
> > longer subscribed to netdev as a result (been living in firmware land
> > doing work in Rust).
> > 
> > I have no immediate plans to pick this up, at least not in the short
> > to medium term. My work in progress was on the laptop I returned and I
> > cannot immediately recall what solution I had in mind here.
> 
> Jakub, sorry if this has been discussed already in the past, but can you
> please clarify what is an accepted (or more importantly, not accepted)
> solution for this issue? I'm not familiar with the history and don't
> want to repeat previous mistakes.

The problem is basically that attributes can only be 64kB and 
the legacy SR-IOV API wraps all the link info in an attribute.

> So far I've seen discussions about increasing the recv buffer size, and
> this patchset which changes the GETLINK ABI, both of which were nacked.

Filtering out some of the info, like the stats, is okay, but that just
increases the limit. A limit still exists.

> Having 'ip link show' broken is very unfortunate :\, how should one
> approach this issue in 2023?

Sure is, which is why we should be moving away from the legacy SR-IOV
APIs.