RE: Gen-ART LC Review of draft-ietf-forces-model-extension-03

["Haleplidis Evangelos" <[e-mail]>]

Greetings Ben,

Thank you for your response. Please see inline.

Regards,
Evangelos Haleplidis.

> From: Ben Campbell [mailto:[e-mail]]
> 
> Hi, thanks for the response. Comments inline. I've removed sections
> that don't seem to need further comment.

[ΕΗ] Same here! :)

> >> -- IDNits points out that this draft may need the pre-RFC5378
> >> boilerplate, due to content from RFC 5812. It does appear to include
> >> substantial amounts of XML schema from 5812. While the publication
> >> date of 5812 post-dates RFC5378, there were many revisions of the
> >> draft form that pre-date 5378 by some time. So unless the author has
> >> gotten permission from all 5812 authors (and I note that author list
> >> changed several times prior to publication), this draft and any
> >> resulting RFC may well need the boilerplate.
> >>
> >
> > [ΕΗ] Thank you for catching this as I have very little experience
> with
> > this kind of issues.
> > As I have not asked permission from the RFC5812 authors, what should
> > be the proper way to resolve this issue?
> > Ask for permission or use a previous boilerplate?
> 
> Asking permission is the best choice, because it would allow you to
> publish this one with the "fully complies" boilerplate. That has the
> advantage of allowing any future IETF works incorporate content from it
> without having the same issue.
> 
> But that may be a tricky thing to do. I note that the drafts leading up
> to the publication of RFC5812 rotate through a number of authors at
> different times. It may be a bit tricky to figure out the proper list
> of authors to ask permission from. Therefore I would not object if you
> went with the pre-5378 boilerplate. Details are in section 6.d.iii. of
> http://trustee.ietf.org/license-info/IETF-TLP-4.htm .
> 	
> If you are using xml2rfc, the tool can insert the boilerplate for you.
> For details, see http://xml2rfc.ietf.org and scroll down to the light-
> green box that talks about the IETF Trust Legal Provisions boilerplate.
> 

[ΕΗ] I discussed with Joel with regards to the copyright issues.
The short answer is that this document draws directly from RFC5812 and
relies on RFC5812 for such issues (as it uses the same boilerplate).

Is this satisfactory?

> 
> >
> >> Minor issues:
> >>
> >> -- section 2.3, 3rd paragraph:
> >>
> >> The 2119 language in this paragraph seems more like description of
> >> procedures. You really only need 2119 language when you want to
> >> constrain some choice an implementor might make. Also, in the two
> >> cases of "MUST be ignored", please consider using active voice?
> (That
> >> is, who or what must ignore it?)
> >>
> >
> > [ΕΗ] In this specific case (I will reword it) the MUST is a
> constraint
> > that the implementer has to conform for interoperability. Otherwise
> > the model would mean something different from one implementer to the
> > other, e.g. for A's implementation the struct's component may have an
> > access type of "read-write" but for B it may mean "read-only". The
> > MUST there defines that when you define a struct component's access
> > type, it MUST override the whole struct's access type.
> 
> In this particular case, it's not clear to me if the MUST actually
> constrains a choice vs being a statement of fact. If you believe it to
> be the former then I am okay with it. The rewording might help.
> 

[ΕΗ] I reworded it and provided also an example. The text now reads:

"When optional access type for components within a struct are defined, these
components's access type MUST override the access type of the struct. For
example if a struct has an access type of read-write but has a component
that is a read-only counter, the counter's access type MUST be read-only."

I believe that it is an implementation constraint as there are two
possibilities (override or not). With the "MUST" we constrain it to one
(override).

I also changed the two "it MUST be ignored" to "the access type MUST be
ignored" to better specify what "it" is.

> >
> >> -- section 2.4, 2nd paragraph:
> >>
> >> This also seems like a description of general procedures that
> doesn't
> >> really need 2119 language.
> >
> > [ΕΗ] Again I think that the MUST is something that is needed for
> > interoperability issues. The BecomesEqualTo MUST generate only one
> > event when the component reaches that specific value and not while it
> is there.
> >
> >>
> >> -- section 2.4, bulleted paragraph:
> >>
> >> Is this similar to saying that eventBecomesEqualTo effectively
> >> becomes an eventChanged after achieving the target value? Once the
> >> value changes from the target by V or more, does it reset the
> >> becomesEqualTo trigger?
> >>
> >
> > [ΕΗ] No, it does not effectively become an eventChanged. The
> > difference is that it will only be triggered ONCE when the value is
> > changed and not continuously.
> 
> You might consider something like:
> 
> " The event is triggered only when the value of the targeted component
> becomes equal to the event condition value. Implementations MUST NOT
> generate subsequent events while the targeted component?s value remains
> equal to the event condition?s value."
> 

[ΕΗ] Text changed to your suggestion. Thank you.

> >
> >> -- section 6:
> >>
> >> The assertion that the changes in this draft have no effect on
> >> security is a bit of a red flag. This draft introduces new kinds of
> >> properties and events that can be expressed, as well as a change to
> >> the inheritance model. Are you sure none of those have a security
> impact?
> >> It would at least be good to mention, for each of these changes, why
> >> you think it does not affect the prior model security
> considerations.
> >>
> >
> > [ΕΗ] I am no security expert, but I agree with the security
> > considerations of RFC 5812 and have referred that the same applies to
> this document.
> > As we didn't make any major changes in the model, but simply added a
> > few more items, namely a new event, some new properties and a way to
> > define optional access types and complex metadata.
> > These are constructs and do not add anything controversial to the
> > initial model. Now in regards to the inheritance model, we didn't add
> > something new, we simply clarified an issue that existed by
> > introducing the version of the derived from class.
> >
> > However, as I said I'm no security expert (and I don't know if you're
> > one), if a security expert could comment on this, it could be
> helpful.
> >
> 
> No, I am not one.  Hopefully this will get a SecDir review as well. But
> that sort of review usually goes better if the Security Consideration
> section shows your reasoning, along the lines of listing the high-level
> types of changes, and for each, why it has no new security impact. Your
> response contains more of that sort of thing; it might help to add it
> (or parts of it) to the draft.
> 
> I was a bit concerned that the default version for inheritance could be
> an issue, but you addressed that elsewhere.
> 
> [...]=

[ΕΗ] Ok, added part of this. Now the security considerations read the
following:

This document adds only a few constructs to the initial model defined in
RFC5812, namely namely a new event, some new properties and a way to define
optional access types and complex metadata. These constructs do not change
the nature of the the initial model. In addition this document addresses and
clarifies an issue with the inheritance model by introducing the version of
the derivedFrom LFB class.
Thus the security considerations defined in RFC5812 applies to this document
as well as the changes proposed here are simply constructs to write XML
library definitions, as where in RFC5812 and have no effect on security
semantics with the protocol.