On Mon, 2020-10-05 at 12:31 -0700, Jakub Kicinski wrote:
> Yea, I think we're both confused. Agreed with the above.
>
> Are you suggesting:
>
> const struct nla_policy policy[/* no size */] = {
> [HEADER] = NLA_POLICY(...)
> [OTHER_ATTR] = NLA_POLICY(...)
> };
>
> extern const struct nla_policy policy[/* no size */];
>
> op = {
> .policy = policy,
> .max_attr = OTHER_ATTR,
> }
No, that'd be awkward, for the reason you stated below.
> What I'm saying is that my preference would be:
>
> const struct nla_policy policy[OTHER_ATTR + 1] = {
> [HEADER] = NLA_POLICY(...)
> [OTHER_ATTR] = NLA_POLICY(...)
> };
>
> extern const struct nla_policy policy[OTHER_ATTR + 1];
>
> op = {
> .policy = policy,
> .max_attr = ARRAY_SIZE(policy) - 1,
> }
>
> Since it's harder to forget to update the op (you don't have to update
> op, and compiler will complain about the extern out of sync).
Yeah.
I was thinking the third way ;-)
const struct nla_policy policy[] = {
[HEADER] = NLA_POLICY(...)
[OTHER_ATTR] = NLA_POLICY(...)
};
op = {
.policy = policy,
.maxattr = ARRAY_SIZE(policy) - 1,
};
Now you can freely add any attributes, and, due to strict validation,
anything not specified in the policy will be rejected, whether by being
out of range (> maxattr) or not specified (NLA_UNSPEC).
johannes
