Clients Cannot Find Network Scanner

TSquaredF · 02-05-2009, 02:03 PM

I currently have a network with an older machine, which is (usually) operated in headless mode as a data & backup server, with a fixed IP of 192.168.0.10. I have two client machines, a desktop & a laptop, which use DHCP. All three computers are running Slackware-12.2, the clients with a full install & the server without any X components.
I want to set the server to serve a scanner & have been following this link, which is mostly a rewrite of the man page for sane.d. I set up saned per the article, adding the saned:saned user. 'scanimage -L' works for both root & my local user on the server. I can ssh into the server as my desktop user & 'scanimage -L' works. Ditto if I ssh into the server, then 'su -' to root. I can scan either locally from the server or via ssh from the desktop machine. BUT, I cannot get the scanner recognized on the network.
On the server, I have this line in /etc/sane.d/saned.conf:

Code:

192.168.0.0/24

this line in /etc/services:

Code:

sane-port  6566/tcp  #SANE network scanner daemon

& this line in /etc/inetc.conf:

Code:

sane-port  stream  tcp  nowait saned:saned /usr/sbin/saned saned

I have changed the line in /etc/sane.d/saned.conf to just "+", for testing. That didn't work either.
On the clients, I have these two uncommented lines in /etc/sane.d/net.conf:

Code:

connect_timeout = 60
192.168.0.10

My desktop user is in these groups:

Quote:

users lp wheel floppy audio video cdrom plugdev power scanner data vboxusers

My server user is in the same groups, less vboxusers.
The server is identified in /etc/hosts & I can connect to it via ssh & mount nfs shares from it. What am I (not) doing that is killing network scanning?
Regards,
Bill

theNbomr · 02-05-2009, 03:24 PM

Well, I don't actually know squat about the sane service specifically, but here's one place to start, which should be an easy test. The sane server is supposed to be listening on port 6566, so I would try making a tcp connection to the server using netcat (nc) from one or more of your client hosts. If netcat can make a connection, then at least you know that something is listening on that port. If so, turn off the daemon, and see if a connection can still be made. If no connection can then be made, then you've pretty well established that the network side is okay, and that the server daemon is listening on the correct port. If netcat is still able to connect, then it probably indicates that some other process has already grabbed that port, and you can use lsof to track down what the process is (actually, maybe that is a good pace to start, too).
If the server is failing to listen on the port, I would look into SELinux and/or an iptables firewall as the culprit(s).
Consult the lsof and netcat manpages for details on how to use them.
--- rod.

TSquaredF · 02-07-2009, 12:10 PM

Re: theNbomr's post, above

I did use netcat to check the servers port, 6566. It is open when the sane-port line in inetd.conf is uncommented & closed when the line is commented out. I also uncommented the line "localhost" in /etc/sane.d/net.conf. I then ran:

Quote:

scanimage -f "scanner number %i device %d is a %t, model %m, produced by %v"

which gave me this output:

Quote:

scanner number 0 device epson2:libusb:001:003 is a flatbed scanner, model GT-9300, produced by Epson
scanner number 1 device net:localhost:epson2:libusb:001:003 is a flatbed scanner, model GT-9300, produced by Epson

so the network backend is also working on the localhost.
The manpage/How-Tos say that the only modification needed on the client is to add the host name/IP address to /etc/sane.d/net.conf. I have tried all variations of host name/IP address to no avail. Anyone have any ideas?
Regards,
Bill

mrclisdue · 02-12-2009, 01:12 PM

I had the same problem, and it took me some hair pulling to figure it out:

You're going to love the solution....

Code:

Add the user 'saned' to the 'scanner' group

cheers,