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

From: Daniel.Machon
Date: Mon Oct 31 2022 - 08:46:50 EST


> > + 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.

/ Daniel