Re: [netmod] IETF ACL model

[Kristian Larsson <[e-mail]>]

Right, it's not about the concept as such, I think we've agreed that
having a global attachment point is fine. It's just that we need to
polish the actual implementation and seeing how it be good to merge the
current PR I suggested we put the global attachment point in a separate
PR. Eases the workflow :)

   kll

Mahesh Jethanandani <[e-mail]> writes:

> For now.
>
> Kristian and I discussed this, and agreed that we will pull it in in a new pull request.
>
>> On Nov 29, 2017, at 4:08 PM, Sonal Agarwal (agarwaso) <[e-mail]> wrote:
>> 
>> Are you removing the definition  of “global” ACL?
>> 
>> -
>> leaf global {
>> -
>> if-feature global-attachment;
>> -
>> type
>> empty;
>> -
>> description
>> -
>> "ACL rule is global";
>> - }
>> 
>> The remaining changes look fine to me.
>> 
>> Thanks,
>> ---
>> Sonal Agarwal
>> 
>> From: Mahesh Jethanandani <[e-mail] <mailto:[e-mail]>>
>> Date: Wednesday, November 29, 2017 at 12:11 PM
>> To: NetMod WG <[e-mail] <mailto:[e-mail]>>
>> Cc: "Robert Wilton -X (rwilton - ENSOFT LIMITED at Cisco)" <[e-mail] <mailto:[e-mail]>>, Jeffrey Haas <[e-mail] <mailto:[e-mail]>>, Cisco Employee <[e-mail] <mailto:[e-mail]>>, Kristian Larsson <[e-mail] <mailto:[e-mail]>>, Kristian Larsson <[e-mail] <mailto:[e-mail]>>, Martin Bjorklund <[e-mail] <mailto:[e-mail]>>
>> Subject: Re: [netmod] IETF ACL model
>> 
>> The updated commit here <https://github.com/netmod-wg/acl-model/pull/19/commits/37e4c030180ae052a5fae26ca86813970fc6b4bf> takes care of restoring “type" to "acl-type", fixes some indentation issues, adds a choice for “l3" where either “ipv4" or “ipv6" can be selected, and a similar choice at “l4" that allows either “tcp", “udp" or “icmp" to be selected, and removes changes for “global" attachment point. Will add the last item as a separate commit.
>> 
>> Unless I hear objections, I will roll the pr/18 changes into the master branch in 48 hours.
>> 
>>> On Nov 28, 2017, at 2:17 AM, Martin Bjorklund <[e-mail] <mailto:[e-mail]>> wrote:
>>> 
>>> Mahesh Jethanandani <[e-mail] <mailto:[e-mail]>> wrote:
>>>> An updated version of the model has been posted as part of the PR here
>>>> <https://github.com/netmod-wg/acl-model/commit/2477cd400cce6d39933c908ad97da27ff759588b <https://github.com/netmod-wg/acl-model/commit/2477cd400cce6d39933c908ad97da27ff759588b>>.
>>>> 
>>>> The particular change removes any-acl from the model, expands on eth
>>>> (to ethernet), removes acl- prefix for things like acl-type and
>>>> acl-name. Please review.
>>> 
>>> I think 99% of the changes in this PR look good.  The one
>>> exception is the typedef that used to be called "acl-type".  I think
>>> it should still be called "acl-type".  "type" is too broad.  NOTE,
>>> this is just the typedef; the leaf /access-lists/acl/type should keep
>>> its name ("type").
>>> 
>>> 
>>> /martin
>>> 
>>> 
>>> 
>>>> 
>>>>> On Nov 27, 2017, at 5:17 AM, Kristian Larsson <[e-mail] <mailto:[e-mail]>>
>>>>> wrote:
>>>>> 
>>>>> 
>>>>> Robert Wilton <[e-mail] <mailto:[e-mail]>> writes:
>>>>> 
>>>>>> Thinking about this some more. I'm not sure what it means for the "ACL
>>>>>> Type" to be "any-acl". It seems that the "match any packet" should be
>>>>>> a
>>>>>> type of ACE, e.g. perhaps as the last entry of an ACL, rather than a 
>>>>>> type of ACL.
>>>>> 
>>>>> Yes, I agree as so far that any-acl makes no sense as an acl-type. The
>>>>> way I understood acl-type, and the way that vendors have told me it
>>>>> will
>>>>> be used, is to say "this is an IPv4 ACL" and then on an attachment
>>>>> point
>>>>> you can specify that only ACLs of acl-type ipv4-acl can be attached to
>>>>> the interface. That makes perfect sense. I do not see how any-acl can
>>>>> map into this.
>>>>> 
>>>>> I agree that any-acl is logically a type of ACE but we don't have an
>>>>> ace-type and the exact same information can IMHO already be conveyed
>>>>> WITHOUT the any-acl type and thus it has no reason to exist. Nor do we
>>>>> need a feature for it.
>>>>> 
>>>>> From what I can tell the any-acl container in the ACE should be used
>>>>> to
>>>>> explicitly signify a match on "any". Think of IOS style ipv4 acl:
>>>>> permit ip any any
>>>>> 
>>>>> We have to provide a source and destination so this would be a rather
>>>>> explicit mapping of that. However, our structure in this YANG model is
>>>>> just completely different than an IOS command so I don't see why we
>>>>> should try and mimic IOS in the YANg model.
>>>>> 
>>>>> Not specifying a destination IP address means we match on any
>>>>> destination IP address. The same is true for any other field we can
>>>>> match on. Not setting a match implies we don't try to match on that
>>>>> field, thus we allow "any" value. I think the logical continuation of
>>>>> this is that for an ACE with no matches defined at all, we match any
>>>>> packet. I think we can update the text to better explain this.
>>>>> 
>>>>> 
>>>>> 
>>>>>> Otherwise if the ACL type is "any-acl" then this only allows two types
>>>>>> of ACLs to be defined, neither of which seem to be particularly
>>>>>> useful:
>>>>>> (1) An ACL that matches all traffic and permits it, i.e. the same as 
>>>>>> having no ACL at all.
>>>>>> (2) An ACL that matches all traffic and drops.
>>>>>> 
>>>>>> So I think perhaps the answer here is to define neither ACL type 
>>>>>> "any-acl" nor leaf "any". The presumption could be that any ACE that
>>>>>> is
>>>>>> configured to match no fields implicitly matches all packets (because 
>>>>>> all non specified fields are treated as wildcards), and then applies
>>>>>> the
>>>>>> permit/deny rule associated with the ACE. This logic can apply to all 
>>>>>> ACL types.
>>>>> 
>>>>> Yes yes yes :)
>>>>> 
>>>>>  Kristian.
>>>> 
>>>> Mahesh Jethanandani
>>>> [e-mail] <mailto:[e-mail]>
>>>> 
>> 
>> Mahesh Jethanandani
>> [e-mail] <mailto:[e-mail]>
>
> Mahesh Jethanandani
> [e-mail]