[cups-devel] systemd blocks port with cups 2.2.0

[Michael Sweet]

More than likely you have a conflicting systemd socket configuration file - current releases of CUPS do not include IP listeners in the systemd configuration files by default as an added security measure since most systems do not share printers, but some Linux distributions change that...

> On Sep 22, 2016, at 4:12 PM, Andreas Radke <a.radke at arcor.de> wrote:
> 
> The cups 2.2.0 update lead to blocked addresses/port and webinterface access is forbidden.
> 
> E [22/Sep/2016:21:53:12 +0200] Unable to open listen socket for address 0.0.0.0:631 - Address already in use.
> E [22/Sep/2016:21:53:12 +0200] Unable to open listen socket for address 192.168.1.90:631 - Address already in use.
> E [22/Sep/2016:21:55:52 +0200] Unable to open listen socket for address [v1.::1]:631 - Address already in use.
> E [22/Sep/2016:21:55:52 +0200] Unable to open listen socket for address 127.0.0.1:631 - Address already in use.
> E [22/Sep/2016:21:55:52 +0200] Unable to open listen socket for address 192.168.1.90:631 - Address already in use.
> 
> cupsd.conf has worked well with all releases before.
> 
> Listen localhost:631
> Listen 192.168.1.90:631
> Listen /run/cups/cups.sock
> 
> A downgrade to cups 2.1.4 and server restart seems to free up the port and brings cups interface back and then updating to cups 2.2.0 also stays working. A reboot blocks it again.
> 
> root at server64:/root # ss -lpn|grep 631                                                                                                                        
> tcp    LISTEN     0      128      :::631                  :::*                   users:(("cupsd",pid=1218,fd=4),("systemd",pid=1,fd=44))
> root at server64:/root # lsof -i :631                                                                                                                            
> COMMAND  PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
> systemd    1 root   44u  IPv6  11152      0t0  TCP *:ipp (LISTEN)
> cupsd   1218 root    4u  IPv6  11152      0t0  TCP *:ipp (LISTEN)
> 
> 
> Any idea what has changed in cups or is this a bug in systemd that now comes up?
> 
> -Andy
> Arch Linux
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_________________________________________________________
Michael Sweet, Senior Printing System Engineer