[arch-general] /etc/dbus-1/systemd/cups.conf and /usr/lib/systemd/system/cups.socket files

[Tom Gundersen]

On Wed, Aug 22, 2012 at 7:31 PM, Myra Nelson <myra.nelson at hughes.net> wrote:
> After my research on sysvinit, the simple version, I'm working my way
> through systemd. Two things I noticed about the cups configuration:
>
> 1: The cups.conf file in /etc/dbus-1/systemd reads

Notice that this should have been "system.d" and not "systemd". These
are the dbus configuration files (for the system bus), and not the
systemd ones.

> <!DOCTYPE busconfig PUBLIC "-//freedesktop//DTD D-BUS Bus Configuration 1.0//EN"
>  "http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd">
> <busconfig>
>   <!-- Only root can send this message -->
>   <policy user="root">
>     <allow send_interface="com.redhat.PrinterSpooler"/>
>   </policy>
>
>   <!-- Allow any connection to receive the message -->
>   <policy context="default">
>     <allow receive_interface="com.redhat.PrinterSpooler"/>
>   </policy>
> </busconfig>
>
> Do the allow send and allow receive interfaces need to be changed, or
> is this taken into account by the rest of systemd?

Sorry that I can't help you with more details, don't know cups/dbus that well.

> 2. The /usr/lib/systemd/system/cups.socket reads
> [Unit]
> Description=CUPS Printing Service Sockets
>
> [Socket]
> ListenStream=/var/run/cups/cups.sock
> ListenStream=631
> ListenDatagram=0.0.0.0:631
> BindIPv6Only=ipv6-only
>
> [Install]
> WantedBy=sockets.target

Again, I don't know much about CUPS, so can't answer your question.
However, just in case it was not clear, the above socket  file gives
you:

# ss -l -u -t | grep ipp
udp    UNCONN     0      0                    *:ipp                   *:*
tcp    LISTEN     0      128                 :::ipp                  :::*

Where the tcp socket only accepts ipv6 connections. Please see
systemd.socket(5) and ipv6(7) for more details.

> With the
> newer version of cups depending on avahi and the differences in the
> avahi hosts file and the hosts file, avahi uses gandalf.local while
> hosts still uses .localdomain.

Not sure I got this last bit. Avahi defaults to using the "local"
domain, but this can be configured if you prefer something else (at
least I seem to remember doing that at some point).

HTH,

Tom