IPP> Re: FW: IPPGET inconsistency on comparing URLs

IPP> Re: FW: IPPGET inconsistency on comparing URLs

mjoel at netreon.com mjoel at netreon.com
Mon Jul 16 14:53:55 EDT 2001


Hi Tom,

I'm doing a case sensitive comparison, since the ippget spec says to do a
byte-by-byte comparison and the notification spec says that the address
portion is opaque.  I realized that method conflicts with normal URL
comparison rules, but figured that since it was stated, it over-rode the
normal rules.

Marty






"Hastings, Tom N" <hastings at cp10.es.xerox.com> on 07/16/2001 10:50:14 AM

To:   "Marty Joel (E-mail)" <mjoel at netreon.com>
cc:   "Tom Hastings (E-mail)" <hastings at cp10.es.xerox.com>, "Bob Herriot
      (E-mail)" <rherriot at pahv.xerox.com>, "McDonald Ira at Sharp (E-mail)"
      <imcdonald at sharplabs.com>, "Ira at Xerox XR&T McDonald (E-mail)"
      <IMcDonald at crt.xerox.com>

Subject:  FW: IPPGET inconsistency on comparing URLs


Marty,

How is your Printer doing the compare of the "notify-recipients-uri" in the
Get-Notifications Request with the same attribute in the Subscription
objects to see if there is a match?

Do you do any case conversion or not?

IPPGET is self contradictory (see email below).

Here is the extract from RFC 2616:

3.2.3 URI Comparison

   When comparing two URIs to decide if they match or not, a client
   SHOULD use a case-sensitive octet-by-octet comparison of the entire
   URIs, with these exceptions:

      - A port that is empty or not given is equivalent to the default
        port for that URI-reference;

        - Comparisons of host names MUST be case-insensitive;

        - Comparisons of scheme names MUST be case-insensitive;

        - An empty abs_path is equivalent to an abs_path of "/".

   Characters other than those in the "reserved" and "unsafe" sets (see
   RFC 2396 [42]) are equivalent to their ""%" HEX HEX" encoding.

   For example, the following three URIs are equivalent:

      http://abc.com:80/~smith/home.html
      http://ABC.com/%7Esmith/home.html
      http://ABC.com:/%7esmith/home.html


Thanks,
Tom

-----Original Message-----
From: McDonald, Ira
Sent: Monday, July 16, 2001 08:09
To: Hastings, Tom N; Herriot, Robert; McDonald Ira at Sharp (E-mail)
Subject: RE: IPPGET inconsistency on comparing URLs


Hi Tom,

YIKES - I think that octet for octet (not byte, please) comparison is
correct, because for 'Get-Notifications' the URL is an entirely opaque
identifier, right?

Cheers,
- Ira

>  -----Original Message-----
> From:   Hastings, Tom N
> Sent:   Sunday, July 15, 2001 3:00 AM
> To:     Bob Herriot (E-mail); McDonald Ira at Sharp (E-mail); Ira at
Xerox
XR&T McDonald (E-mail)
> Cc:     Tom Hastings (E-mail)
> Subject:     IPPGET inconsistency on comparing URLs
>
> Help!  I found that IPPGET says one place that a client or Printer
compares "notify-recipient-uri" URL byte for byte and another place where
it
says it uses the usual URL comparison rules.  I suspect that the simpler
byte comparison was done to make it simpler.
>
> Section 5.1 Get-Notifications Request says:
>
>         "notify-recipient-uri" (url):
> The client MUST supply this attribute.  The Printer object MUST support
this attribute. The Printer matches the value of this attribute (byte for
byte with no case conversion) against the value of the
"notify-recipient-uri" in each Subscription Object in the Printer. If there
are no ...
>
>
> Section 9.5.2     IPPGET URL Comparisons
> When comparing two 'ippget' URLs to decide if they match or not, an IPP
Client or IPP Printer MUST use the same rules as those defined for HTTP URI
comparisons in [RFC2616].
>
> What should we do?  I think the byte for byte comparison for comparing
the
URI in Get-Notifications with Subscription Objects makes the most sense.
Correct?  There isn't any reason why a Printer would change the URI that a
Subscribing Client supplies in a Subscription Creation operation from that
supplied in a Get-Notifications Request is there?
>
> Thanks,
> Tom
>







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