Network Scanning With Sane

This page describes how to enable Network Scanning using a USB scanner or multi-function printer in Merlin using S.A.N.E. (Scan Access Now Easy).

Requirements:

• A router running Merlin duh...
• USB Stick with Entware configured instructions
• A USB Scanner or Multi-Function Printer
• Router accessible via ssh
• Familiarity with ssh access and command line tools line vi

Router Setup Instructions:

• Ssh to router and type

opkg install sane-backends sane-frontends sane-libs dbus xinetd

• Create file /opt/etc/xinetd.d/saned and put the following content:

service saned
{
    type = UNLISTED
    port = 6566
    socket_type = stream
    server = /opt/sbin/saned
    protocol = tcp
    user = <REPLACE HERE WITH YOUR ADMIN USERNAME>
    group = root
    wait = no
    disable = no
}

• Edit file /opt/share/dbus-1/system.conf and replace the following line:
  <user>root</user>
  with
  <user>__REPLACE HERE WITH YOUR ADMIN USERNAME__</user>

• Edit file /opt/etc/sane.d/saned.conf and add your subnet to allow access, for example: 192.168.1.0/24

• Reboot router and make sure that dbus and xinetd are running (this step might not be required if you know how to start the services manually from /opt/etc/init.d)

NOTE: should you experience the service dbus not coming up after router reboot. Simply add the following lines to the file /opt/etc/init.d/S20dbus before the line . /opt/etc/init.d/rc.func:

if test -f /opt/var/run/dbus.pid; then
        rm /opt/var/run/dbus.pid
fi

Special Hardware Instructions

HP:

• Ssh to router and type the command: opkg --force-overwrite install hplip hplip-full

• Create /opt/etc/init.d/S01hplip file and put the following content:

  Script

  #!/bin/sh
  
  PATH=/sbin:/bin:/usr/bin:/usr/sbin:/opt/bin:/opt/sbin
  
  HPLIP_VERSION=$(grep ^version= /opt/etc/hp/hplip.conf | sed -En 's/version=(.*)/\1/p')
  
  if [ -z "$HPLIP_VERSION" ]; then
      logger "hplip version not found in /opt/etc/hp/hplip.conf"
      exit 0
  fi
  
  logger "creating /var/lib/hp/hplip.state with version $HPLIP_VERSION"
  
  mkdir -p /var/lib/hp
  
  cat <<EOT > /var/lib/hp/hplip.state
  [plugin]
  installed = 1
  eula = 1
  version = $HPLIP_VERSION
  EOT
  

NOTE: should you experience an error about missing /opt/share/hplip/scan/plugins/bb_marvell.so or other plugins in the system log, add the required files from hplip-plugin: download the .run file of the corresponding plugin version (run grep ^version= /opt/etc/hp/hplip.conf to find out), open it as a tar archive and extract the arm32 or arm64 versions (depending on your router model) of the missing plugins to the corresponding locations indicated in the log.

Test functionality:

• Type: scanimage -L, your device should be displayed
• Type: scanimage --test, your device should start testing and display status

On The Client Side (Linux):

• Install the sane package. This changes by distribution
• Edit file /etc/sane.d/net.conf and add the ip or hostname of the router
• Test the same way with the scanimage utility

On The Client Side (Windows):

• Download SaneTwain http://sanetwain.ozuzo.net
• On start-up put the router's ip/host

Web UI (Linux / Docker):

• Check https://github.com/sbs20/scanservjs

Suggestions are always welcomed.