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

Re: [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.

Re: [PATCH net 2/4] tools: ynl-gen: use macro for binary min-len check

[Jakub Kicinski]

On Mon,  1 Sep 2025 14:50:21 +0000 Asbjørn Sloth Tønnesen wrote:
> This patch changes the generated min-len check for binary
> attributes to use the NLA_POLICY_MIN_LEN() macro, and thereby
> ensures that .validation_type is not left at NLA_VALIDATE_NONE.

Please test this well and include the results in the commit message.
I'm pretty sure it's fine as is.

Re: [PATCH net 3/4] tools: ynl-gen: fix nested array counting

[Jakub Kicinski]

On Mon,  1 Sep 2025 14:50:22 +0000 Asbjørn Sloth Tønnesen wrote:
> The blamed commit introduced the concept of split attribute
> counting, and later allocating an array to hold them, however
> TypeArrayNest wasn't updated to use the new counting variable.
> 
> Abbreviated example from tools/net/ynl/generated/nl80211-user.c:
> nl80211_if_combination_attributes_parse(...):
>   unsigned int n_limits = 0;
>   [...]
>   ynl_attr_for_each(attr, nlh, yarg->ys->family->hdr_len)
> 	if (type == NL80211_IFACE_COMB_LIMITS)
> 		ynl_attr_for_each_nested(attr2, attr)
> 			dst->_count.limits++;
>   if (n_limits) {
> 	dst->_count.limits = n_limits;
> 	/* allocate and parse attributes */
>   }
> 
> In the above example n_limits is guaranteed to always be 0,
> hence the conditional is unsatisfiable and is optimized out.
> 
> This patch changes the attribute counting to use n_limits++ in the
> attribute counting loop in the above example.

Looks good, thanks!

Reviewed-by: Jakub Kicinski <kuba@kernel.org>

Re: [PATCH net 4/4] genetlink: fix typo in comment

[Jakub Kicinski]

On Mon,  1 Sep 2025 14:50:23 +0000 Asbjørn Sloth Tønnesen wrote:
> In this context "not that ..." should properly be "note that ...".
> 
> Fixes: b8fd60c36a44 ("genetlink: allow families to use split ops directly")

Looks good, but this is not a fix, please repost without the Fixes tag
and for net-next.