For our IPP WG telecon today, I'd like to consider two alternatives to
enhancing Cancel-Job and Purge-Jobs operations that are simpler to
understand than the ones we agreed to at the last IPP Telecon. Alternative
1 does not quite provide all of the flexibility as CUPS:
ftp://ftp.pwg.org/pub/pwg/ipp/wd/Cancel-Job-and-Purge-Jobs-alternative1-v6-2
0091004.pdf
ftp://ftp.pwg.org/pub/pwg/ipp/wd/Cancel-Job-and-Purge-Jobs-alternative1-v6-2
0091004.doc
<ftp://ftp.pwg.org/pub/pwg/ipp/wd/wd-ippprodprintext10-v6-20091004.pdf>
while Alternative 2 does:
ftp://ftp.pwg.org/pub/pwg/ipp/wd/Cancel-Job-and-Purge-Jobs-alternative2-v6-2
0091004.pdf
ftp://ftp.pwg.org/pub/pwg/ipp/wd/Cancel-Job-and-Purge-Jobs-alternative2-v6-2
0091004.doc
In order to make the comparison easier, I've also uploaded just the proposed
changes to Cancel-Job and Purge-Jobs as agreed to at the last IPP WG
telecon:
ftp://ftp.pwg.org/pub/pwg/ipp/wd/Cancel-Job-and-Purge-Jobs-additions-v6-2009
1004.pdf
ftp://ftp.pwg.org/pub/pwg/ipp/wd/Cancel-Job-and-Purge-Jobs-additions-v6-2009
1004.doc
<ftp://ftp.pwg.org/pub/pwg/ipp/wd/wd-ippprodprintext10-v6-20091004.pdf>
Alternative 1 Summary
Alternative 1 includes the following functionality:
being able to cancel all my jobs, instead of just the specified job
being able to purge all my jobs, instead of just all jobs
If Michael is willing to update CUPS (to support the old and something new),
Alternative 1 would be to add only the following Operation attribute to
Cancel-Job:
"all-my-jobs" (boolean) with default 'false'
instead of adding "cancel-jobs" (boolean) with default 'false' to the
Purge-Jobs operation. Then we would NOT have an operation attribute
("cancel-jobs") which changes one operation (Purge-Jobs) into another
operation (Cancel-Job).
Similarly, another new and simpler alternative to add only the following
Operation attribute to Purge-Jobs:
"my-jobs" (boolean) with default value 'false'.
instead of adding either "purge-jobs" (boolean) or "cancel-jobs" (boolean)
operation attribute to Purge-Jobs. Then we would NOT have an operation
attribute ("cancel-jobs" or "purge-jobs") which changes one operation
(Purge-Jobs) into another operation (Cancel-Job).
Furthermore, I think that this alternative for Purge-Jobs is so simple that
we don't need the complicated table.
Alternative 2 Summary
This Alternative 2 is slightly more complicated than alternative 1, but gets
all of the functionality that the CUPS proposal includes:
being able to cancel all jobs or all my jobs, instead of just the specified
job
being able to purge a specified job or all my jobs, instead of just all
jobs.
If Michael is willing to update CUPS (to support the old and something new),
alternative 2 would be to add only the following Operation attribute to
Cancel-Job operation:
"which-jobs" (type2 keyword) with values:
'specified-job' - (default) cancel the job specified by the supplied
"job-id" or "job-url"
'all-my-jobs' - cancel all my jobs
'all-jobs' - cancel all jobs;
If the Printer's security policy does not allow the authenticated user to
cancel jobs for which the requesting user is not the owner, then the IPP
object MUST reject the operation and return client-error-not-authorized
instead of adding "cancel-jobs" (boolean) with default 'false' to the
Purge-Jobs operation. Then we would NOT have an operation attribute
("cancel-jobs") which changes one operation (Purge-Jobs) into another
operation (Cancel-Job).
Similarly, alternative 2 to add the following 3 Operation attribute to
Purge-Jobs:
"job-id" (integer(1:MAX)) - specifies the job to be purged
"job-url" (url) - specifies the job to be purged
"which-jobs" (type2 keyword) with values:
'specified-job' - purge the job specified by the supplied "job-id" or
"job-url"
'all-my-jobs' - purge all my jobs
'all-jobs' - (default) purges all jobs
If the Printer's security policy does not allow the authenticated user to
purge jobs for which the requesting user is not the owner, then the IPP
object MUST reject the operation and return client-error-not-authorized
instead of adding either "purge-jobs" (boolean) or "cancel-jobs" (boolean)
operation attribute to Purge-Jobs. Then we would NOT have an operation
attribute ("cancel-jobs" or "purge-jobs") which changes one operation
(Purge-Jobs) into another operation (Cancel-Job).
Furthermore, I think that this alternative for Purge-Jobs is so simple that
we don't need the complicated table.
Tom
-----Original Message-----
From: Tom Hastings [mailto:tom.hastings at verizon.net]
Sent: Sunday, October 04, 2009 09:23
To: 'Michael Sweet'; tom.hastings at alum.mit.edu
Cc: 'Ira McDonald'; ipp at pwg.org
Subject: RE: {Disarmed} Re: [IPP] Descriptions of CUPS additions to the
Cancel-Job and Purge-Jobs operations
Michael,
My mistake in my email. I meant to say Cancel-Job operation, not
Cancel-Jobs operation. We don't have a Cancel-Jobs operation. So I was
trying to suggest to either add "all-my-jobs" (boolean) or add "which-jobs"
(type2 keyword) Operation attribute to the existing Cancel-Job operation.
Tom
-----Original Message-----
From: Michael Sweet [mailto:msweet at apple.com]
Sent: Saturday, October 03, 2009 20:35
To: tom.hastings at alum.mit.edu
Cc: 'Ira McDonald'; ipp at pwg.org
Subject: Re: {Disarmed} Re: [IPP] Descriptions of CUPS additions to the
Cancel-Job and Purge-Jobs operations
That would be great if we *did* have a Cancel-Jobs operation; when you
mentioned it I looked and wasn't able to find it - Cancel-Job and
Cancel-Current-Job are all that I see...
On Oct 3, 2009, at 6:09 PM, Tom Hastings wrote:
> Good discussion.
>
> If Michael is willing to update CUPS (to support the old and
> something new), another new alternative would be to add the
> following Operation attribute to Cancel-Jobs:
>
> "all-my-jobs" (boolean) with default 'false' to the Cancel-Jobs
> operation
>
> instead of adding "cancel-jobs" (boolean) with default 'false' to
> the Purge-Jobs operation. Then we wouldn't have an operation
> attribute ("cancel-jobs") which changes an one operation (Purge-
> Jobs) into another operation (Cancel-Jobs).
>
> A variant on my alternative above which would allow the Operator/
> Administrator to be able to cancel all jobs (as is possible with
> current CUPS, but uses Purge-Jobs) is to add the following Operation
> attribute to the Cancel-Jobs operation:
>
> "which-jobs" (type2 keyword) with values:
> 'specified-job' - (default) the job specified by the supplied "job-
> id" or "job-url"
> 'all-my-jobs' - cancel all my jobs
> 'all-jobs' - cancel all jobs; If the Printer's security policy does
> not allow the authenticated user to cancel jobs for which the
> requesting user is not the owner, then the IPP object MUST reject
> the operation and return client-error-not-authorized
>
>
>
> Following the thrust of the above alternatives which avoid having an
> operation attribute change the semantics of the operation to that of
> another operation, how about also adding "job-id" (integer(1:MAX))
> and "job-url" (URL) to the Purge-Jobs operation. If either are
> supplied, then the specified job is purged, rather than all jobs.
> If the requesting user is NOT an Operator/Administrator AND the
> specified job is NOT owned by the requesting user, then the IPP
> object MUST reject the operation and return client-error-not-
> authorized.
>
> Think about these alternative for the discussion at the IPP WG
> telecon, this Monday, October 5, 1:00 PM PDT = 4:00 PM EDT.
>
> In the meantime, I'll post the original CUPS approach rather than
> making some of these discussed changes.
>
> Thanks,
> Tom
>
>
> From: Michael Sweet [mailto:msweet at apple.com]
> Sent: Friday, October 02, 2009 10:51
> To: Ira McDonald
> Cc: tom.hastings at alum.mit.edu; ipp at pwg.org
> Subject: Re: {Disarmed} Re: [IPP] Descriptions of CUPS additions to
> the Cancel-Job and Purge-Jobs operations
>
> FWIW, we can rev this to use a "cancel-jobs" attribute instead of
> "purge-jobs" for the Purge-Jobs operation, and I'll update CUPS
> accordingly (to support both the old and new names...) so that the
> defaults are all false.
>
> On Oct 2, 2009, at 10:24 AM, Ira McDonald wrote:
>
>
> Hi,
>
> I generally agree with Mike's comments below.
>
> But I really dislike a boolean that defaults to 'true' - this
> needs work.
>
> Cheers,
> - Ira
>
> Ira McDonald (Musician / Software Architect)
> Chair - Linux Foundation Open Printing WG
> Blue Roof Music/High North Inc
> email: blueroofmusic at gmail.com
> winter:
> 579 Park Place Saline, MI 48176
> 734-944-0094
> summer:
> PO Box 221 Grand Marais, MI 49839
> 906-494-2434
>
>
> On Fri, Oct 2, 2009 at 11:53 AM, Michael Sweet <msweet at apple.com>
> wrote:
> Comments inline...
>
> On Sep 30, 2009, at 7:10 PM, Tom Hastings wrote:
>> I'm struggling mightily to write up the Cancel-Job and Purge-Job
>> operations as suggested by Michael and have come up with a bunch of
>> issues. Since HTML may not come through the email reflector with
>> the 5 MS-WORD ISSUE comments intact and the table shown, I've also
>> downloaded the .doc of just these attributes with my suggested
>> descriptions and the ISSUES as MS-WORD comments to:
ftp://ftp.pwg.org/pub/pwg/ipp/wd/Attributes_to_add_to_Cancel-Job_and_Purge-J
obs_operations.doc
>> .
>>
>>
>> The 5 ISSUES are as follows:
>>
>>
>> ISSUE 1: Allowing an unprivileged user to purge his job using
>> Cancel-Job, could circumvent accounting in those systems that use
>> Retained Jobs and Job History for accounting.
>>
>>
>> ISSUE 2: Allowing an unprivileged user to purge his jobs using
>> Purge-Jobs, could circumvent accounting in those systems that use
>> Retained Jobs and Job History for accounting.
>>
>> One solution would be to only allow Purge-Jobs for operator or
>> administrator as in [RFC 2911].
>>
>> ISSUE 3: Instead of adding "my-jobs" and "purge-job" to Purge-Jobs,
>> a simpler way to allow an unprivileged user to cancel all his jobs,
>> instead of just a specified job, would be to add "all-my-
>> jobs" (boolean) Operation attribute to the Cancel-Job operation.
>> When the client supplies this attribute with a 'true' value, the
>> client MUST NOT supply a "job-id" or "job-url" Operation attribute.
>>
>>
>> ISSUE 4: Or should the spec say the Printer MUST reject the Purge-
>> Jobs operation if the unprivileged client supplies the "my-jobs" =
>> 'false' and return: client-error-forbidden, client-error-not-
>> authenticated, and client-error-not-authorized as appropriate, as
>> for Purge-Jobs in RFC 2911 section 3.2.9
>>
>>
>> ISSUE 5: The "purge-job" (boolean) Operation attribute has the
>> 'true' value here as its default. Usually, it's the 'false' value
>> that is the default. More confusingly, the "purge-job" (boolean)
>> Operation attribute (correctly) has the 'false' value in the Cancel-
>> Job operation above.
>>
>>
>> I've included the text in the draft which I will post tomorrow for
>> this Monday's IPP WG telecon, October 5, at 1:00 PM PDT = 4:00 PM
>> EDT, but I wanted to start people thinking about these issues.
>> Hopefully, we can resolve these issues at the meeting so that I can
>> update the draft for the face to face meeting in Cupertino, the
>> following week, October 12-14.
>>
>>
>>
>> Here is what I've come up with. Comments and suggestions are
>> welcome:
>>
>>
>> 4.3 Cancel-Job operation
>>
>> This section specified an additional operation attribute for use
>> with the Cancel-Jobs operation (see [RFC2911] Section 3.3.3).
>>
>> 4.3.1 purge-job[th1] (boolean)
>>
>> The "purge-job" Operation attribute controls whether the specified
>> job is canceled or purged as follows:
>>
>> 'false': Default value. The Printer cancels the specified job as
>> specified in [RFC2911] Section 3.3.3 which MAY leave a Retained Job
>> with document data on the Printer for possible re-processing (e.g.,
>> using the Reprocess-Job or Resubmit-Job operations) and/or Job
>> History. Note: If the client omits this attribute or supplies the
>> 'false' value, the behavior of the Cancel-Job operation is as
>> specified in [RFC2911].
>>
>> 'true': If the authenticated user is the job owner of the job
>> specified by the "job-id" or "job-uri" operation attribute or is a
>> privileged operator or administrator of the Printer, the Printer
>> MUST purge the specified job according to the semantics of the
>> Purge-Jobs operation independent of the job's state, but only for
>> the specified job, i.e., remove all record of the specified job,
>> including attributes, history and document data.
>>
>> The client MAY supply this Operation attribute and the Printer MAY
>> support this Operation attribute in the Cancel-Job operation.
>>
>
> I'd just make the authenticated user case more generic, and also
> document that Cancel-Jobs with purge-jobs=true will fail if the user
> is not authorized, e.g.:
>
> 'true': If the authenticated user is allowed to purge a job by the
> Printer's security policy (typically if the owner of the job
> specified by the "job-id" or "job-uri" operation attribute matches)
> or is a privileged operator or administrator of the Printer, the
> Printer MUST purge the specified job according to the semantics of
> the Purge-Jobs operation independent of the job's state, but only
> for the specified job, i.e., remove all record of the specified job,
> including attributes, history and document data. Otherwise, the IPP
> object MUST reject the operation and return: client-error-forbidden,
> client-error-not-authenticated, and client-error-not-authorized as
> appropriate.
>
> The wording of the last sentence matches RFC 2911's Purge-Jobs
> description.
>>
>> 4.4 Purge-Jobs operation
>>
>> This section specified additional operation attributes for use with
>> the Cancel-Jobs operation (see [RFC2911] Section 3.3.7).
>>
>> 4.4.1 my-jobs[th2] [th3] (boolean)
>>
>> The "my-jobs" Operation attribute allows the client to request the
>> target jobs to be (1) all jobs or (2) only jobs owned by the
>> requesting user. However, the Printer MUST further restrict the
>> target jobs as follows:
>>
>> 'false': Default value. The target jobs are all jobs, unless the
>> Authenticated user supplying the request is NOT an operator or
>> administrator of the Printer, in which case the Printer MUST
>> restrict the target jobs to those belonging to the requesting user.
>> [th4]
>>
>> 'true': The target jobs are limited to those owned by the
>> Authenticated user submitting the request.
>>
>> The client MAY supply this Operation attribute and the Printer MAY
>> support this Operation attribute in the Purge-Jobs operation.
>>
>
> I'd add the following to the 4.4 introduction to address th2-th5:
>
> Access Rights: The following attributes may allow the authenticated
> user (see RFC 2911 section 8.3) performing this operation to be an
> ordinary user depending on the Printer's security policy. When
> ordinary users are not allowed to use the Purge-Jobs operation, the
> IPP object MUST continue to reject the operation and return: client-
> error-forbidden, client-error-not-authenticated, and client-error-
> not-authorized as appropriate.
>
> Then move the table into 4.4, before the description of the
> attributes.
>
>
> 4.4.2 purge-job (boolean)
>
> The "purge-job" Operation attribute controls whether the target jobs
> are canceled or purged as follows:
>
> 'false': The Printer cancels the target jobs as specified in
> [RFC2911] Section 3.3.3 Cancel-Job which MAY leave a Retained Job
> with document data on the Printer for possible re-processing (e.g.,
> using the Reprocess-Job or Resubmit-Job operations) and/or Job
> History.
>
> 'true': Default value[th5] . The Printer purges the target jobs
> as specified in [RFC2911] Section 3.2.9 Purge-Jobs. Note: If the
> client omits this attribute or supplies the 'true' value, the
> behavior of the Purge-Jobs operation is as specified in [RFC2911]
> for the target jobs.
>
> The client MAY supply this Operation attribute and the Printer MAY
> support this Operation attribute in the Purge-Jobs operation.
>
> The behavior for the Purge-Jobs operation for these two Operation
> attributes for unprivileged users vs. operators and administrator of
> the Printer is shown in Table 2.
>
> Table 2: Interaction of "my-jobs" and "purge-jobs" attributes in the
> Purge-Jobs operation
>
> Operation attributes
>
> Unprivileged user
>
> Operator or Administrator of the Printer
>
> "my-jobs" = 'false' or omitted
> "purge-jobs" = 'false'
>
> Cancel only my jobs (Printer overrides "my-jobs" = 'false')
>
> Cancel all jobs
>
> "my-jobs" = 'true'
> "purge-jobs" = 'false'
>
> Cancel only my jobs
>
> Cancel only my jobs
>
> "my-jobs" = 'false' or omitted
> "purge-jobs" = 'true' or omitted
>
> Purge only my jobs (Printer overrides "my-jobs" = 'false')
>
> Purge all jobs
>
> "my-jobs" = 'true'
> "purge-jobs" = 'true' or omitted
>
> Purge only my jobs
>
> Purge only my jobs
>
>
>
> -----Original Message-----
> From: ipp-bounces at pwg.org [mailto:ipp-bounces at pwg.org] On Behalf Of
> Michael Sweet
> Sent: Monday, September 14, 2009 14:41
> To: ipp at pwg.org
> Subject: [IPP] Descriptions of CUPS additions to the Cancel-Job and
> Purge-Jobs operations
>
> All,
>
> Here are the descriptions for the CUPS additions to the Cancel-Job and
> Purge-Jobs operations. These came up in today's conference call...
>
> ------------------------------------------------------
>
> Cancel Job Operation
>
> The Cancel-Job operation (0x0008) cancels the specified job. CUPS 1.4
> adds a new purge-job (boolean) attribute that allows you to purge both
> active and completed jobs, removing all history and document files for
> the job as well.
>
> Cancel-Job Request
>
> The following groups of attributes are supplied as part of the Cancel-
> Job request:
>
> Group 1: Operation Attributes
>
> Natural Language and Character Set:
> The "attributes-charset" and "attributes-natural-language"
> attributes as described in section 3.1.4.1 of the IPP Model and
> Semantics document.
>
> "printer-uri" (uri) and "job-id" (integer)
> OR
> "job-uri":
> The client MUST supply a URI for the specified printer and a job
> ID number, or the job URI.
>
> "purge-job" (boolean):
> The client OPTIONALLY supplies this attribute. When true, all job
> files (history and document) are purged. The default is false, leading
> to the standard IPP behavior.
>
>
> Cancel-Job Response
>
> The following groups of attributes are send as part of the Cancel-Job
> Response:
>
> Group 1: Operation Attributes
>
> Status Message:
> The standard response status message.
>
> Natural Language and Character Set:
> The "attributes-charset" and "attributes-natural-language"
> attributes as described in section 3.1.4.2 of the IPP Model and
> Semantics document.
>
>
> Purge-Jobs Operation
>
> The Purge-Jobs operation (0x0012) cancels all of the jobs on a given
> destination and optionally removes all history and document files for
> the jobs as well.
>
> Purge-Jobs Request
>
> The following groups of attributes are supplied as part of the Purge-
> Jobs request:
>
> Group 1: Operation Attributes
>
> Natural Language and Character Set:
> The "attributes-charset" and "attributes-natural-language"
> attributes as described in section 3.1.4.1 of the IPP Model and
> Semantics document.
>
> "printer-uri" (uri):
> The client MUST supply a URI for the specified printer or
"ipp://.../printers
> " for all printers and classes.
>
> "requesting-user-name" (name(MAX)):
> The client OPTIONALLY supplies this attribute to specify whose
> jobs jobs are purged or canceled.
>
> "my-jobs" (boolean):
> The client OPTIONALLY supplies this attribute to specify that
> only the jobs owned by the requesting user are purged or canceled. The
> default is false.
>
> "purge-jobs" (boolean):
> The client OPTIONALLY supplies this attribute to specify whether
> the jobs are purged (true) or just canceled (false). The default is
> true.
>
>
> Purge-Jobs Response
>
> The following groups of attributes are send as part of the Purge-Jobs
> Response:
>
> Group 1: Operation Attributes
>
> Status Message:
> The standard response status message.
>
> Natural Language and Character Set:
> The "attributes-charset" and "attributes-natural-language"
> attributes as described in section 3.1.4.2 of the IPP Model and
> Semantics document.
> __________________________________________________
> Michael Sweet, Senior Printing System Engineer
>
> --
> This message has been scanned for viruses and
> dangerous content by MailScanner, and is
> believed to be clean.
> _______________________________________________
> ipp mailing list
>ipp at pwg.org
>https://www.pwg.org/mailman/listinfo/ipp
> ISSUE: Allowing an unprivileged user to purge his job using Cancel-
> Job, could circumvent accounting in those systems that use Retained
> Jobs and Job History for accounting.
>
> ISSUE: Allowing an unprivileged user to purge his jobs using Purge-
> Jobs, could circumvent accounting in those systems that use Retained
> Jobs and Job History for accounting.
>
>
> One solution would be to only allow Purge-Jobs for operator or
> administrator as in [RFC 2911].
>
> ISSUE: Instead of adding "my-jobs" and "purge-job" to Purge-Jobs, a
> simpler way to allow an unprivileged user to cancel all his jobs,
> instead of just a specified job, would be to add "all-my-
> jobs" (boolean) Operation attribute to the Cancel-Job operation.
> When the client supplies this attribute with a 'true' value, the
> client MUST NOT supply a "job-id" or "job-url" Operation attribute.
>
> ISSUE: Or should the spec say the Printer MUST reject the operation
> and return: client-error-forbidden, client-error-not-authenticated,
> and client-error-not-authorized as appropriate, as for Purge-Jobs in
> RFC 2911 section 3.2.9
>
> ISSUE: The "purge-job" (boolean) Operation attribute has the 'true'
> value here as its default. Usually, it's the 'false' value that is
> the default. More confusingly, the "purge-job" (boolean) Operation
> attribute (correctly) has the 'false' value in the Cancel-Job
> operation above.
>
> __________________________________________________
>
> Michael Sweet, Senior Printing System Engineer
>
> --
> This message has been scanned for viruses and
> dangerous content by MailScanner, and is
> believed to be clean.
> _______________________________________________
> ipp mailing list
>ipp at pwg.org
>https://www.pwg.org/mailman/listinfo/ipp
> ___________________________________________________
> Michael Sweet, Senior Printing System Engineer
>
>
>
___________________________________________________
Michael Sweet, Senior Printing System Engineer
--
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.pwg.org/archives/ipp/attachments/20091005/e3fc4621/attachment.html