Printing with smbspool_krb5_wrapper not working in Ubuntu 16.04

[Van Svensson]

I have two computers, one with Ubuntu 14.04 LTS and one with Ubuntu 16.04 LTS. On both computers I have configured the printer with cups to print by using my Kerberos credential in the same way and it works in 14.04 but not in 16.04.

In 16.04 the print job just stays listed forever in "lpq" until I manually remove it with "lprm", while it goes through to the printer in 14.04.

For both 14.04 and 16.04 I have that
* /usr/bin/smbspool_krb5_wrapper is chmod 700
* "AuthInfoRequired negotiate" is set in /etc/cups/printers.conf
* /usr/lib/cups/backend/smb is a symbolic link to /usr/bin/smbspool_krb5_wrapper

The users does not exist in /etc/passwd, instead they are in LDAP and when they log in to the computer they get some Kerberos tickets for the domain and the network file system. When printing on 14.04 they get another Kerberos ticket for the printing system according to "klist" after they have done "lpr" and printed a document. On 16.04 nothing is printed and the user gets no Kerberos ticket for the printing system and the job is left in "lpq".

On 14.04 I have Samba version 2:4.3.11+dfsg-0ubuntu0.14.04.10 and on 16.04 I have 2:4.3.11+dfsg-0ubuntu0.16.04.9. I attach the smb.conf file which is exactly the same for both 14.04 and 16.04.

On 14.04 I have CUPS 1.7.2-0ubuntu1.8 and on 16.04 I have 2.1.3-4.

I attach how it looks like in /var/log/cups/error_log, after setting "LogLevel debug" in /etc/cups/cupsd.conf, in 16.04 where it does not work (I have just changed my uid and gid to 1000). When I compare the log with 14.04 where it does work I see that 16.04 uses two backslashes when setting KRB5CCNAME while 14.04 does not use backslashes, maybe that is the problem?

Thanks for any ideas about what goes wrong in 16.04 or how I can track down the problem, e.g., by comparing with 14.04 where it does work!

[Van Svensson (vansven)]

Sometimes the cups error_log also have the below line "HTTP_STATE_WAITING Closing for error 32 (Broken pipe)". Both this line and the line "Could not determine network interfaces, you must use a interfaces config line" maybe can give some idea on what goes wrong?

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

[Van Svensson (vansven)]

/etc/samba/smb.conf - same for both Ubuntu 14.04 and 16.04

[Andreas Hasenack (ahasenack)]

Hello,

it looks like we can remove samba from the equation here, correct? You seem to be denied printing just by logging in on the ubuntu 16.04 box and issuing lpr.

[Andreas Hasenack (ahasenack)]

Can you please share your /etc/cups/cupsd.conf file, and the output of klist on the 14.04 box just after you login and issue the lpr command? I.e., it should show the ticket for the printing service.

[Launchpad Janitor (janitor)]

[Expired for samba (Ubuntu) because there has been no activity for 60 days.]