Re: [PATCH net-next v4 2/6] net: dcb: add new apptrust attribute

Petr Machata
2022-10-31T16:25:18Z

<Daniel.Machon@microchip.com> writes:

>> > + if (ieee[DCB_ATTR_DCB_APP_TRUST_TABLE]) {
>> > + u8 selectors[IEEE_8021QAZ_APP_SEL_MAX + 1] = {0};
>> > + struct nlattr *attr;
>> > + int nselectors = 0;
>> > + u8 selector;
>> > + int rem, i;
>> > +
>> > + if (!ops->dcbnl_setapptrust) {
>> > + err = -EOPNOTSUPP;
>> > + goto err;
>> > + }
>> > +
>> > + nla_for_each_nested(attr, ieee[DCB_ATTR_DCB_APP_TRUST_TABLE],
>> > + rem) {
>> > + if (nla_type(attr) != DCB_ATTR_DCB_APP_TRUST ||
>> > + nla_len(attr) != 1 ||
>> > + nselectors >= sizeof(selectors)) {
>> > + err = -EINVAL;
>> > + goto err;
>> > + }
>> > +
>> > + selector = nla_get_u8(attr);
>> > + switch (selector) {
>> > + case IEEE_8021QAZ_APP_SEL_ETHERTYPE:
>> > + case IEEE_8021QAZ_APP_SEL_STREAM:
>> > + case IEEE_8021QAZ_APP_SEL_DGRAM:
>> > + case IEEE_8021QAZ_APP_SEL_ANY:
>> > + case IEEE_8021QAZ_APP_SEL_DSCP:
>> > + case DCB_APP_SEL_PCP:
>>
>> This assumes that the range of DCB attributes will never overlap with
>> the range of IEEE attributes. Wasn't the original reason for introducing
>> the DCB nest to not have to make this assumption?
>>
>> I.e. now that we split DCB and IEEE attributes in the APP_TABLE
>> attribute, shouldn't it be done here as well?
>
> Hmm, doesn't hurt to do strict checking here as well. We can even get rid
> of the DCB_ATTR_DCB_APP_TRUST attr and just pass DCB_ATTR_DCB_APP and
> DCB_ATTR_IEEE_APP? Then use the same functions to do the checking.

That would make sense to me.