Using Cups Filter To Apply Watermarking

[Ah-U3]

Dear All,

Your help is much appreciated,

I'm using OpenPrinting CUPS 2.4.2 on debian OS

I'm trying to use cups filter to generate watermark on the printed document.

My cups server is connected to Xerox Printer and Xerox accouting is enabled in the PPD file configuration i've XSA accounting.

When I try to print without adding the filter to the PPD file, the print job is successful and the user static accounting information is passed to the printer.

However when I try to add the filter the PPD file isnot loaded and the printer cancel the job as the user account isnot supplied to the printer.

please help me to pin point what I did wrong

I have shell script filter added to /usr/lib/cups/filter

I applied it to the PPD file as below

This is where I placed my filter in the PPD file

_```
*PPD-Adobe: "4.3"
*cupsMandatory: attributes-charset attributes-natural-language printer-uri

*% Adobe Systems PostScript(R) Printer Description File
*% Copyright 2009 Xerox Corporation.

*% PPD File Info

*FileVersion: "5.482.0.0"
*FormatVersion: "4.3"
*LanguageEncoding: ISOLatin1
*LanguageVersion: English

*% Device Info

*Manufacturer: "Xerox"
*ModelName: "Xerox WorkCentre 7855"
*ShortNickName: "Xerox WorkCentre 7855"
*NickName: "Xerox WorkCentre 7855"
*PCFileName: "Xerox WorkCentre 7855.ppd"
*Product: "(Xerox WorkCentre 7855)"
*Product: "(1.3.6.1.4.1.253.8.62.1.20.6.27.1.1)"
*XRXHasPS: True
*XRXHasAdvancedFax: False
*XRXHasBooklet: False
*PSVersion: "(3010.106) 3000"
*ColorDevice: True
*DefaultColorSpace: CMYK
*FileSystem: True
*?FileSystem: "
save false
(%disk?%)
{ currentdevparams dup /Writeable known
{ /Writeable get {pop true} if } { pop } ifelse
} 10 string /IODevice resourceforall
restore"
*End
*LanguageLevel: "3"
*Protocols: BCP PJL TBCP
*Throughput: "55"
*ADHasEuro: True
*TTRasterizer: Type42
*DefaultGuaranteedMaxSeparations: 1
*1284Modes Parallel: Compat
*FreeVM: "15003225"
*VMOption None/Standard: "15003225"
*FCacheSize None: 2631384

*cupsFilter: application/vnd.cups-postscript 100 /usr/lib/cups/filter/customwatermarkfilter.sh

*OpenUI *SetPageDevice: PickOne

===================================================
I ran tcpdump to capture the traffic with and without the filter and I notice that with the filter the PPD file isn't loaded and the accounting data isn't sent to the printer 


**This is tcpdump sample without any filter filter** 

> ```
> .........G..attributes-charset..utf-8H..attributes-natural-language..en.E..job-uri..ipp://printerip/2821!..job-id......#.	job-state......D..job-state-reasons..job-incoming!..number-of-intervening-jobs.......POST /ipp/print HTTP/1.1
> Content-Type: application/ipp
> Date: Wed, 19 Feb 2025 05:04:55 GMT
> Host: printerip:631
> Transfer-Encoding: chunked
> User-Agent: CUPS/2.4.2 (Linux 6.1.0-29-amd64; x86_64) IPP/2.0
> Expect: 100-continue
> 
> ef
> .........G..attributes-charset..utf-8H..attributes-natural-language..en-usE..printer-uri.!ipp://printerip:631/ipp/print!..job-id......B..requesting-user-name..john-it".
> last-document...I..document-format..application/octet-stream.
> HTTP/1.1 100 Continue
> 
> 2000
> .%-12345X@PJL
> @PJL
> @PJL COMMENT XRXbegin
> @PJL JOB NAME = "Microsoft Word - TestPrint.docx" DISPLAY = "48 john-it Microsoft Word -"
> @PJL SET USERNAME = "john-it"
> @PJL COMMENT OID_ATT_START_SHEET OID_VAL_JOB_SHEET_FULL
> @PJL XCPT <?xml version="1.0" encoding="UTF-8"?>
> @PJL XCPT <!DOCTYPE xpif SYSTEM "xpif-v02074.dtd">
> @PJL XCPT <xpif version="1.0" cpss-version="2.07" xml:lang="en-US">
> @PJL XCPT          <job-template-attributes>
> @PJL XCPT              <client-default-attributes-col syntax="collection">
> @PJL XCPT                  <job-accounting-user-id syntax="name" xml:space="preserve">9999</job-accounting-user-id>
> @PJL XCPT                  <job-accounting-user-passcode syntax="octetString"></job-accounting-user-passcode>
> @PJL XCPT                  <job-accounting-user-passcode-encryption syntax="keyword">xerox-simple-1</job-accounting-user-passcode-encryption>
> @PJL XCPT                  <job-billing-passcode-encryption syntax="keyword">xerox-simple-1</job-billing-passcode-encryption>
> @PJL XCPT              </client-default-attributes-col>
> @PJL XCPT          </job-template-attributes>
> @PJL XCPT </xpif>
> @PJL COMMENT OID_ATT_JOB_TYPE OID_VAL_JOB_TYPE_PRINT
> @PJL COMMENT XRXend
> @PJL ENTER LANGUAGE = POSTSCRIPT
> %!PS-Adobe-3.0
> ```

===============================================================


**This tcpdump sample  with cups filter applied**

_.........G..attributes-charset..utf-8H..attributes-natural-language..en-usE..printer-uri.!ipp://printerip:631/ipp/print!..job-id......B..requesting-user-name..john-it".
last-document...I..document-format..application/octet-stream.
HTTP/1.1 100 Continue

10f
GPL Ghostscript 10.0.0 (2022-09-21)
Copyright (C) 2022 Artifex Software, Inc. All rights reserved.
This software is supplied under the GNU AGPLv3 and comes with NO WARRANTY:
see the file COPYING for details.
Processing pages 1 through 1.
Page 1
recoverable image error

0

HTTP/1.1 200 OK
Date: Wed, 19 Feb 2025 02:34:22 GMT
Server: Apache
X-Frame-Options: SAMEORIGIN
Upgrade: TLS/1.2, HTTP/1.1
Connection: upgrade
Content-Length: 211
Cache-Control: max-age=0, no-store
Content-Type: application/ipp

.........G..attributes-charset..utf-8H..attributes-natural-language..en.E..job-uri..ipp://printerip/2822!..job-id......#. job-state......D..job-state-reasons..job-incoming!..number-of-intervening-jobs.......POST /ipp/print HTTP/1.1
Content-Length: 753
Content-Type: application/ipp
Date: Wed, 19 Feb 2025 05:06:39 GMT
Host: printerip:631
User-Agent: CUPS/2.4.2 (Linux 6.1.0-29-amd64; x86_64) IPP/2.0
Expect: 100-continue

.........G..attributes-charset..utf-8H..attributes-natural-language..en-usE..printer-uri.!ipp://printerip:631/ipp/printB..requesting-user-name..john-itD..requested-attributes..compression-supportedD....copies-supportedD....cups-versionD....document-format-supportedD...!job-password-encryption-supportedD...
marker-colorsD....marker-high-levelsD...
marker-levelsD....marker-low-levelsD....marker-messageD....marker-namesD....marker-typesD....media-col-supportedD...$multiple-document-handling-supportedD....operations-supportedD....print-color-mode-supportedD...
printer-alertD....printer-alert-descriptionD....printer-is-accepting-jobsD... printer-mandatory-job-attributesD...
printer-stateD....printer-state-messageD....printer-state-reasons.HTTP/1.1 100 Continue

HTTP/1.1 200 OK
Date: Wed, 19 Feb 2025 02:34:22 GMT
Server: Apache
X-Frame-Options: SAMEORIGIN
Upgrade: TLS/1.2, HTTP/1.1
Connection: upgrade
Content-Length: 2441
Cache-Control: max-age=0, no-store
Content-Type: application/ipp_

=================================
**Cups error log**

D [19/Feb/2025:09:10:31 +0300] [Job 54] printer-is-accepting-jobs boolean true
D [19/Feb/2025:09:10:31 +0300] [Job 54] printer-mandatory-job-attributes 1setOf keyword attributes-charset,attributes-natural-language,printer-uri
D [19/Feb/2025:09:10:31 +0300] [Job 54] printer-state enum idle
D [19/Feb/2025:09:10:31 +0300] [Job 54] printer-state-message textWithoutLanguage
D [19/Feb/2025:09:10:31 +0300] [Job 54] printer-state-reasons keyword none
D [19/Feb/2025:09:10:31 +0300] [Job 54] ---- end-of-attributes-tag ----
D [19/Feb/2025:09:10:31 +0300] [Job 54] ATTR: auth-info-required=none
E [19/Feb/2025:09:10:31 +0300] [Job 54] Print job canceled at printer.
D [19/Feb/2025:09:10:31 +0300] [Job 54] Set job-printer-state-message to "Print job canceled at printer.", current level=ERROR
W [19/Feb/2025:09:10:31 +0300] [Job 54] Backend returned status 5 (cancel job)
D [19/Feb/2025:09:10:31 +0300] [Job 54] time-at-completed=1739945431
I [19/Feb/2025:09:10:31 +0300] [Job 54] Job canceled at printer.