Re: #1047 Path-identity: A proposal (perhaps)

["Charles Lindsey" <chl@xxxxxxxxxxxxxxxx>]

In <200506301058.13924.blilly@xxxxxxxxx> Bruce Lilly <blilly@xxxxxxxxx> writes:

>On Wed June 29 2005 08:33, Harald Tveit Alvestrand wrote:
>>   A path-identity identifies an agent. For the news system to work
>>   properly, the path-identity must be globally unique.

>If we mean "public name" we should probably say so: s/identifies/is a
>public name identifying/

Well it is really the text in USEPRO that should say that, but it is a
good point, so the proposed USEPRO text now starts:

   News-servers need to identify themselves by inserting their public
   name, in the form of a <path-identity> (F-3.1.6), into Path,
   Injection-Info and Xref headers. An injecting agent MUST identify
   itself with the same <path-identity> in both Path and Injection-Info
   headers.  To ensure that a <path-identity> provides a unique identity
   for the news-server concerned, it SHOULD be one of: ..........

>Global uniqueness is an interoperability requirement ("to work properly");
>s/must/MUST/ would make that clear.

I think the USEPRO text above covers that.


>Because of the global uniqueness requirement, s/should/MUST/.  Add
>something to address Frank's concern about unauthorized use.

And the proposed USEPRO text also covers that, though it could be
strengthened.


>The ABNF implies that
>  Path: MISMATCH!tail-entry
>and
>  Path: MISMATCH!MISMATCH!tail-entry
>are legal, which I believe is not the intended use of the keywords.

The procedures for constructing a Path entry are contained in my suggested
USEPRO text posted here a week or so ago. It makes it clear exactly where
and when those two keywords may appear, so it is hardly necessary to
complicate the syntax with such matters (and there is no particular need
for agents to take note of those keywords when parsing).

>>   NOTE: The path-address contains characters that some systems consider
>>      path-delimiters. This can cause problems; path-address should
>>      therefore only be used when absolutely necessary.
>>      See [USEPRO] for details on when to use them.


>Because of the backward compatibility/interoperability problem
>s/should/MUST/.

No, because there are plenty of hosts around that have IP addresses but no
domain name. The text proposed for USEPRO makes it clear that IP addresses
are the least desirable alternative.

-- 
Charles H. Lindsey ---------At Home, doing my own thing------------------------
Tel: +44 161 436 6131 Fax: +44 161 436 6133   Web: http://www.cs.man.ac.uk/~chl
Email: chl@xxxxxxxxxxxxxxxx      Snail: 5 Clerewood Ave, CHEADLE, SK8 3JU, U.K.
PGP: 2C15F1A9      Fingerprint: 73 6D C2 51 93 A0 01 E7 65 E8 64 7E 14 A4 AB A5