Ubuntu Manpage: scanbm- User scanning support daemon for scanbd / scanbd manager

name
synopsis
description
options
scanbd/scanbm configuration
network setup for scanbm
inetd configuration
see also
author

NAME

       scanbm- User scanning support daemon for scanbd / scanbd manager

SYNOPSIS

       scanbm [-c configfile [-d[debuglevel] ] [-s] [-t device -a action ]

       scanbd -m [-c configfile [-d[debuglevel] ] [-s] [-t device -a action ]

DESCRIPTION

scanbm is a companion to scanbd, a scanner button monitoring daemon that can trigger execution of scripts
when a button is pressed.

scanbm is actually a (symbolic) link to scanbd and can be called as scanbm or scanbd -m.

scanbd (the scanner button daemon) opens and polls the scanner and therefore locks the device. So no
other application can access the device directly (open the /dev/..., or via libusb, etc).

To enable scanning from applications, we use scanbm as a manager for scanbd. scanbm is a "proxy" for
saned to access the scanner from an application. scanbm listens for requests on the saned network port.
All applications therefore need to use the "net backend to access a scanner.

If a scan request arrives to scanbm on the sane-port, scanbm requests the scanbd scanner polling daemon
to interrupt polling and to release the device by sending it a dbus-message (default) or a posix-signal
(SIGUSR1) (signal-mode). It then starts the real saned which does the scanning and sends the data back
to the requesting application. When the scanning is done and saned exits, scanbm requests scanbd to
restart the polling by sending a second dbus-message (or the posix-signal SIGUSR2) and ends execution.
The polling scanbd now re-enables polling of the devices.

scanbm is meant to be started from inetd, xinetd or systemd. Unlike saned it does not support stand-
alone mode.

Note: Please note that the scanbm acts as a proxy to saned, all scanner applications must be configured
to use the sane "net" backend to access the scanner. Direct access will not be possible.

OPTIONS

       -c configfile --config=configfile
              Use configfile instead of the default /etc/scanbd/scanbd.conf configuration file.

       -d[debuglevel] --debug[=debuglevel]
              turn debug mode on. If specified, set the debug level to debuglevel
              1 = error
              2 = warn
              3 = info
              4 - 7 = debug)

       -s --signal
              use signals SIGUSR1/ SIGUSR2 instead of dbus messages to request the  polling  scanbd  to  stop  /
              restart polling

       -t device --trigger=device
              Trigger action for device (numerical)

       -a action --action=action
              action (numerical) to be triggered

SCANBD/SCANBM CONFIGURATION

       scanbd  and  scanbm are configured trough scanbd.conf (/etc/scanbd/scanbd.conf or the file pointed out by
       the -c <config-file> )

NETWORK SETUP FOR SCANBM

       scanbm must be setup very similar to the way saned must be setup.  Note that your inetd must support IPv6
       if you want to connect to scanbm over IPv6 ; xinetd, openbsd-inetd and systemd are known to support IPv6,
       check the documentation for your inetd daemon.

INETD CONFIGURATION

       For scanbm it is also necessary to add a configuration line to /etc/inetd.conf just like it is for saned.

       The configuration line normally looks like this:

              sane-port stream tcp nowait scanbd.scanbd /usr/sbin/scanbm scanbm

       However, if your system uses tcpd(8) for additional security screening, you may  want  to  disable  saned
       access  control  by  putting  ``+'' in saned.conf (see saned(8) ) and use a line of the following form in
       /etc/inetd.conf instead:

              sane-port stream tcp nowait scanbd.scanbd /usr/sbin/tcpd /usr/sbin/scanbm

       Note that both examples assume that there is a scanbd group and  a  scanbd  user.   If  you  follow  this
       example,  please make sure that the access permissions on the special device are set such that scanbd and
       saned can access the scanner (the programs generally need read and write access to scanner devices).

       If xinetd is installed on your system instead of inetd the  following  example  for  xinetd.conf  may  be
       helpful:

              # default: off
              # description: The sane server accepts requests
              # for network access to a local scanner via the
              # network.
              service sane-port
              {
                 port        = 6566
                 socket_type = stream
                 wait        = no
                 user        = scanbd
                 group       = scanbd
                 server      = /usr/sbin/scanbm
                 server_args =
              }

       Finally, it is also necessary to add a line of the following form to /etc/services:

              sane-port 6566/tcp # SANE network scanner daemon

       The official IANA short name for port 6566 is "sane-port". The older name "sane" is now deprecated.

       scanbm does not do access control, but it relies on the access control done by saned.

AUTHOR

       Louis Lagendijk