[PATCH net 1/4] netlink: specs: fou: change local-v6/peer-v6 check

[Jakub Kicinski]

On Mon,  1 Sep 2025 14:50:20 +0000 Asbjørn Sloth Tønnesen wrote:
> While fixing the binary min-len implementaion, I noticed that
> the only user, should AFAICT be using exact-len instead.
> 
> In net/ipv4/fou_core.c FOU_ATTR_LOCAL_V6 and FOU_ATTR_PEER_V6
> are only used for singular IPv6 addresses, a exact-len policy,
> therefore seams like a better fit.
> 
> AFAICT this was caused by lacking support for the exact-len check
> at the time of the blamed commit, which was later remedied by
> c63ad379526 ("tools: ynl-gen: add support for exact-len validation").

No, take a look at 1d562c32e43. The intention was to keep the code
before and after the same. I agree that the check is not ideal but
it's not really a bug to ignore some input. So if you want to clean
this up -- net-next and no Fixes tag..

> This patch therefore changes the local-v6/peer-v6 attributes to
> use an exact-len check, instead of a min-len check.