Messages in this thread | | | From | <> | Subject | Re: [net-next v3 1/6] net: dcb: add new pcp selector to app object | Date | Thu, 27 Oct 2022 09:00:54 +0000 |
| |
> >> I'm missing a validation that DCB_APP_SEL_PCP is always sent in > >> DCB_ATTR_DCB_APP encapsulation. Wouldn't the current code permit > >> sending it in the IEEE encap? This should be forbidden. > > > > Right. Current impl. does not check that the non-std selectors received, are > > sent with a DCB_ATTR_DCB_APP type. We could introduce a new check > > dcbnl_app_attr_selector_validate() that checks combination of type and > > selector, after the type and nla_len(attr) has been checked, so that: > > > > validate type -> validate nla_len(attr) -> validate selector > > This needs to be validated, otherwise there's no point in having a > dedicated attribute for the non-standard stuff.
Agree.
> > >> And vice versa: I'm not sure we want to permit sending the standard > >> attributes in the DCB encap. > > > > dcbnl_app_attr_type_get() in dcbnl_ieee_fill() takes care of this. IEEE are > > always sent in DCB_ATTR_IEEE and non-std are sent in DCB_ATTR_DCB. > > By "sending" I meant userspace sending this to the kernel. So bounce > extended opcodes that are wrapped in IEEE and bounce IEEE opcodes > wrapped in DCB as well.
Right. Then we only need to decide what to do with any opcode in-between (not defined in uapi, neither ieee or extension opcode, 7-254). If they are sent in DCB_ATTR_DCB they should be bounced, because we agreed that we can interpret data in the new attr), _but_ if they are sent in DCB_ATTR_IEEE I guess we should accept them, to not break userspace that is already sending them.
Here is what that could look like:
/* Make sure any non-std selectors is always encapsulated in the non-std * DCB_ATTR_DCB_APP attribute. */ static bool dcbnl_app_attr_selector_validate(enum ieee_attrs_app type, u32 selector) { switch (selector) { case DCB_APP_SEL_PCP: /* Non-std selector in non-std attr? */ if (type == DCB_ATTR_DCB_APP) return true; default: /* Std selector in std attr? */ if (type == DCB_ATTR_IEEE_APP) return true; }
return false; }
/ Daniel
| |