[sane-devel] Problem with Sane over network

[Luca Bertoncello]

Hi list!

My first question, here...

So, I have a scanner, Canon LiDE35, connected via USB to a RaspberryPI
with Debian Buster.
The scanner works well and I can scan using scanimage.
I installed scanbd in order to manage the buttons on the scanner and now
I can copy and mail documents.
Wonderful!

Last point: using the scanner from other PC in the network.
It does NOT work... :(

First of all: the Raspi is in a different network as the PCs!
Anyway I added this line to the saned.conf on the Raspi:

192.168.10.0/24

So I should use the scanner from all PCs in the network 192.168.10.0/24...

In my PC with Debian Stretch (192.168.10.3), I added this line to
/etc/sane.d/net.conf:

192.168.5.10

that is the IP of the Raspi.
In /etc/sane.d/dll.conf on my PC I have:

net

so that I should be able to scan over network...
Unfortunately scanimage -L finds nothing... :(
In the syslog of the Raspi I see:

Apr 12 10:11:53 scanner systemd[1]: Started Scanner Service
(192.168.10.3:41450).
Apr 12 10:11:53 scanner scanbm: /usr/sbin/scanbm: dbus match
type='signal',interface='org.freedesktop.Hal.Manager'
Apr 12 10:11:54 scanner kernel: [ 3888.935640] usb 1-1.5: reset
high-speed USB device number 4 using dwc_otg
Apr 12 10:11:54 scanner saned[1024]: saned (AF-indep+IPv6) from
sane-backends 1.0.27 starting up
Apr 12 10:11:54 scanner saned[1024]: check_host: access by remote host:
::ffff:192.168.10.3
Apr 12 10:11:54 scanner saned[1024]: init: access granted to
lucabert@::ffff:192.168.10.3
Apr 12 10:12:01 scanner saned[1024]: saned exiting
Apr 12 10:12:02 scanner systemd[1]:
scanbm at 4-192.168.5.10:6566-192.168.10.3:41450.service: Succeeded.

so I'd say, that my PC is allowed to use the scanner...
But it doesn't... :(

What I see is using tcpdump:

10:11:54.352477 IP 192.168.5.10.8612 > 192.168.5.255.8612: UDP, length 16
10:11:54.352928 IP 192.168.5.10.8612 > 192.168.5.255.8610: UDP, length 16
10:11:54.363284 IP 192.168.5.10.8612 > 192.168.5.255.8612: UDP, length 16
10:11:54.363548 IP 192.168.5.10.8612 > 192.168.5.255.8610: UDP, length 16

Of course the broadcast packets cannot reach my PC on a different network...

I found some HowTo about scanning over different networks, but all of
them refer to pixma, and I don't have this scanner...
I tested it anyway, but (of course!) it does not work...

Can someone help me?

Thanks a lot!
Luca Bertoncello
(lucabert at lucabert.de)