[cups] Printing with SMB-Kerberos in CUPS on Ubuntu 16.04

[Van Svensson]

Hello again,

I have now tested to run smbspool manually with "cat file.ps | smbspool -k 1 myuser test 1" and the printing works on both Ubuntu 14.04 and 16.04!

Any ideas of why smbspool fails in Ubuntu 16.04 LTS when invoked from CUPS 2.1.3-4 (default) while it works perfectly in CUPS 1.7.2-0ubuntu1.8 (default) on Ubuntu 14.04 LTS?

Maybe the error message "Could not determine network interfaces, you must use a interfaces config line" is relevant?

The file /etc/cups/printers.conf looks almost the same in Ubuntu 14.04 and 16.04:

ubuntu_16.04# cat /etc/cups/printers.conf
# Printer configuration file for CUPS v2.1.3
# Written by cupsd
# DO NOT EDIT THIS FILE WHEN CUPSD IS RUNNING
<Printer PDF>
UUID urn:uuid:e9..the_uuid...ed
Info PDF
DeviceURI cups-pdf:/
State Idle
StateTime 1410113686
ConfigTime 1501962091
Type 8450124
Accepting Yes
Shared No
JobSheets none none
QuotaPeriod 0
PageLimit 0
KLimit 0
OpPolicy default
ErrorPolicy retry-job
</Printer>
<DefaultPrinter Myprinter>
UUID urn:uuid:86..the_uuid..6a
AuthInfoRequired negotiate
Info Myprinter
MakeModel KONICA MINOLTA C658SeriesPS(P)
DeviceURI smb://myprinter.my.domain/MYPRINTER
State Idle
StateTime 1491212856
ConfigTime 1501962104
Type 8401100
Accepting Yes
Shared No
JobSheets none none
QuotaPeriod 0
PageLimit 0
KLimit 0
OpPolicy default
ErrorPolicy retry-job
</DefaultPrinter>

# diff ubuntu1404-printers.conf-myprinter ubuntu1604-printers.conf-myprinter
7d6
< PPDTimeStamp *
9a9
> ConfigTime 1501962104
13d12
< ColorManaged Yes
20c19
< </Printer>
---
> </DefaultPrinter>

Thank you very much in advance!

Van Svensson wrote:

> I'm running Ubuntu 14.04 LTS and printing using SMB-Kerberos through CUPS 1.7.2-0ubuntu1.8 (default) and everything works. However, on another computer I have installed Ubuntu 16.04 LTS with CUPS 2.1.3-4 (default) but the printing does no longer work.
> 
> On both 14.04 and 16.04 Samba seem to be the same version, 2:4.3.11+dfsg-0ubuntu0.14.04.10 and 2:4.3.11+dfsg-0ubuntu0.16.04.9.
> 
> For both 14.04 and 16.04 I have that
> * "AuthInfoRequired negotiate" is set in /etc/cups/printers.conf
> * /usr/lib/cups/backend/smb is a symbolic link to /usr/bin/smbspool_krb5_wrapper
> * /usr/bin/smbspool_krb5_wrapper is chmod 700
> 
> Can somebody please help me track down the problem from the CUPS error messages in /var/log/cups/error_log from the 16.04 installation? (I have set "LogLevel debug" in /etc/cups/cupsd.conf)
> 
> D [05/Aug/2017:12:52:04 +0200] [Job 89] SMBSPOOL_KRB5 - Started with uid=0
> D [05/Aug/2017:12:52:04 +0200] [Job 89] SMBSPOOL_KRB5 - AUTH_INFO_REQUIRED=negotiate
> D [05/Aug/2017:12:52:04 +0200] [Job 89] SMBSPOOL_KRB5 - Switching to gid=1000
> D [05/Aug/2017:12:52:04 +0200] [Job 89] SMBSPOOL_KRB5 - Switching to uid=1000
> D [05/Aug/2017:12:52:04 +0200] [Job 89] SMBSPOOL_KRB5 - Setting KRB5CCNAME to \'FILE:/tmp/krb5cc_1000\'
> D [05/Aug/2017:12:52:04 +0200] [Client 12] HTTP_STATE_WAITING Closing for error 32 (Broken pipe)
> D [05/Aug/2017:12:52:04 +0200] [Client 12] Closing connection.
> D [05/Aug/2017:12:52:04 +0200] cupsdSetBusyState: newbusy="Printing jobs and dirty files", busy="Printing jobs and dirty files"
> E [05/Aug/2017:12:52:04 +0200] [Job 89] Could not determine network interfaces, you must use a interfaces config line
> 
> I see that double backslashes are used in 16.04 when SMBSPOOL_KRB5 is setting KRB5CCNAME, can that cause this problem?
> Ubuntu 16.04 /var/log/cups/error_log: SMBSPOOL_KRB5 - Setting KRB5CCNAME to \'FILE:/tmp/krb5cc_1000\'
> Ubuntu 14.04 /var/log/cups/error_log: SMBSPOOL_KRB5 - Setting KRB5CCNAME to 'FILE:/tmp/krb5cc_1000'
> 
> Do you have any idea about what the error "HTTP_STATE_WAITING Closing for error 32 (Broken pipe)" can tell me in this situation when it is printed right after SMBSPOOL_KRB5 has set KRB5CCNAME?
> 
> Also wondering about why I get this right after the above error: "Could not determine network interfaces, you must use a interfaces config line"