p910nd − port 9100+n printer daemon
p910nd [-f device] [-i bindaddr] [-bvd] [0|1|2]
p910nd is a small daemon that copies any data received on the port it is listening on to the corresponding printer port. It is primarily intended for diskless Linux hosts running as printer drivers but there is no reason why it could not be used on diskful hosts. Port 9100 is copied to /dev/lp0, 9101 to /dev/lp1 and 9102 to /dev/lp2. The default is port 9100 to /dev/lp0.
The -f option can be used to specify a different printer device, e.g. /dev/usblp0.
The -i option can be used to specify binding to one address instead of all interfaces which is the default.
The -b option turns on bidirectional copying.
The -v option shows the version number.
The -d option causes the daemon to run in the foreground in standalone mode and prints log messages to stdout for debugging.
p910nd can be run as a standalone daemon or from (x)inetd. It will automatically detect if it is running under (x)inetd.
A sample SysVinit script, p910nd.sh, is provided for operation as a daemon. p910nd will change its name under ps to match the printer port, i.e. p9100d, p9101d and p9102d.
When running under (x)inetd, the /etc/inetd.conf entry should look something like this (with tcpwrappers protection):
p9101 stream tcp nowait root /usr/sbin/tcpd /sbin/p910nd
Don’t forget to add an entry in /etc/services for the corresponding port.
If operating with lprng, use the host%port syntax for the printer device to send jobs to it.
If operating with CUPS, this is supported as the AppSocket protocol, also known as the JetDirect (probably TM) protocol.
If operating with classic Berkeley lpd, a sample client, client.pl, is provided. This should be installed as the ifilter (if=) in /etc/printcap. banner.pl should be installed as the ofilter (of=) in /etc/printcap. It may be necessary to create a dummy spool file for lpd (lp=). This file will be opened but not written to. The corresponding C versions are left as an exercise for the reader.
When running under inetd, more than one instance could be started. To avoid problems with multiple instances attempting to access the printer at the same time, make sure that only one client is active at any one time. This can be done by designating one host as the spooler and sending all jobs to this host. You will probably need to set up an intermediate queue anyway to provide print job filtering.
If built with USE_WRAP, it uses the libwrap library (tcpwrappers). Access control can be done with /etc/hosts.allow and /etc/hosts.deny. The service name is p910nd.
p910nd logs error messages to syslog.
/var/run/p9100d.pid, /var/lock/p910nd/p9100d, /etc/hosts.allow, /etc/hosts.deny
p910nd is under the GNU Public License Version 2
Ken Yap (greenpossum ATSIGN users PERIOD sourceforge PERIOD net)
Version 0.97 January 2014