saned.8



saned(8)                 SANE Scanner Access Now Easy                 saned(8)


NAME

       saned - SANE network daemon


SYNOPSIS

       saned  [ -a [ username ] ] [ -u username ] [ -b address ] [ -p port ] [
       -l ] [ -D ] [ -o ] [ -d n ] [ -e ] [ -h ]


DESCRIPTION

       saned is the SANE (Scanner Access Now Easy) daemon that  allows  remote
       clients  to  access  image  acquisition  devices available on the local
       host.


OPTIONS

       The -l flag requests that saned run in standalone daemon mode.  In this
       mode,  saned  will  listen for incoming client connections; inetd(8) is
       not required for saned operations in this mode. The -b flag tells saned
       to  bind  to  the address given.  The -p flags tells saned to listen on
       the port given.  A value of 0 tells saned to pick an unused port.   The
       default  is the sane-port (6566).  The -u flag requests that saned drop
       root privileges and run as the user (and group) associated  with  user-
       name  after binding.  The -D flag will request saned to detach from the
       console and run in the background.  The flag -a is  equivalent  to  the
       combination of -l -B -u username options.

       The  -d  flag sets the level of saned debug output.  When compiled with
       debugging enabled, this flag may be followed by  a  number  to  request
       more  or  less debug info.  The larger the number, the more verbose the
       debug output.  E.g., -d128 will request output of all  debug  info.   A
       level of 0 produces no output at all.  The default value is 2.

       The  -e  flag  will  divert saned debug output to stderr instead of the
       syslog default.

       The -o flag requests that saned exits after the  first  client  discon-
       nects.  This is useful for debugging.

       The -h flag displays a short help message.

       If  saned  is  run  from other programs such as inetd(8), xinetd(8) and
       systemd(1), check that program's documentation on how to pass  command-
       line options.


CONFIGURATION

       First and foremost: saned is not intended to be exposed to the internet
       or other non-trusted networks. Make sure that access is limited by tcp-
       wrappers  and/or a firewall setup. Don't depend only on saned's own au-
       thentication. Don't run saned as root if it's not necessary. And do not
       install saned as setuid root.

       The  saned.conf configuration file contains both options for the daemon
       and the access list.

       data_portrange = min_port - max_port
              Specify the port range to use for the data  connection.  Pick  a
              port  range  between 1024 and 65535; don't pick a too large port
              range, as it may have performance issues.  Use  this  option  if
              your saned server is sitting behind a firewall. If that firewall
              is a Linux machine, we strongly recommend  using  the  Netfilter
              nf_conntrack_sane module instead.

       data_connect_timeout = timeout
              Specify the time in milliseconds that saned will wait for a data
              connection. Without this option, if the data connection  is  not
              done  before  the  scanner  reaches the end of scan, the scanner
              will continue to scan past the end and may damage  it  depending
              on  the  backend. Specify zero to have the old behavior. The de-
              fault is 4000ms.

       The access list is a list of host names, IP  addresses  or  IP  subnets
       (CIDR  notation) that are permitted to use local SANE devices. IPv6 ad-
       dresses must be enclosed in brackets, and should always be specified in
       their compressed form. Connections from localhost are always permitted.
       Empty lines and lines starting with a hash mark (#) are ignored. A line
       containing the single character ``+'' is interpreted to match any host-
       name. This allows any remote  machine  to  use  your  scanner  and  may
       present a security risk, so this shouldn't be used unless you know what
       you're doing.

       A sample configuration file is shown below:

              # Daemon options
              data_portrange = 10000 - 10100
              # Access list
              scan-client.somedomain.firm
              # this is a comment
              192.168.0.1
              192.168.2.12/29
              [::1]
              [2001:db8:185e::42:12]/64

       The case of the host names does not matter, so AHost.COM is  considered
       identical to ahost.com.


SERVER DAEMON CONFIGURATION

       For saned to work properly in its default mode of operation, it is also
       necessary to add the appropriate configuration for xinetd(8),  inetd(8)
       or  systemd(1)  (see below).  Note that your inetd(8) must support IPv6
       if you want to connect to saned over IPv6; xinetd(8),  openbsd-inetd(8)
       and  systemd(1)  are known to support IPv6, check the documentation for
       your inetd(8) daemon.

       In the sections below the configuration  for  inetd(8),  xinetd(8)  and
       systemd(1) are described in more detail.

       For  the configurations below it is necessary to add a line of the fol-
       lowing 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.


INETD CONFIGURATION

       It  is required to add a single line to the inetd(8) configuration file
       (/etc/inetd.conf)

       The configuration line normally looks like this:

              sane-port stream tcp  nowait  saned.saned  /usr/local/sbin/saned
              saned

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

              sane-port stream tcp nowait saned.saned /usr/sbin/tcpd  /usr/lo-
              cal/sbin/saned

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


XINETD CONFIGURATION

       If  xinetd(8)  is installed on your system instead of inetd(8) the fol-
       lowing example for /etc/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        = saned
                 group       = saned
                 server      = /usr/local/sbin/saned
              }


SYSTEMD CONFIGURATION

       saned can be compiled with explicit systemd(1)support.This  will  allow
       logging  debugging  information to be forwarded to the systemd(1) jour-
       nal. The systemd(1) support requires compilation with the systemd-devel
       package installed on the system. this is the preferred option.

       saned  can  be  used with systemd(1) without the systemd(1) integration
       compiled in, but then logging of debug information is not supported.

       The systemd(1) configuration is different for the 2  options,  so  both
       are described below.


Systemd configuration for saned with systemd support compiled in

       For  systemd(1)  configuration  we need to add 2 configuration files in
       /etc/systemd/system.

       The first file we need to add here is called  saned.socket.   It  shall
       have the following contents:

              [Unit]
              Description=saned incoming socket

              [Socket]
              ListenStream=6566
              Accept=yes
              MaxConnections=1

              [Install]
              WantedBy=sockets.target

       The  second  file to be added is saned@.service with the following con-
       tents:

              [Unit]
              Description=Scanner Service
              Requires=saned.socket

              [Service]
              ExecStart=/usr/sbin/saned
              User=saned
              Group=saned
              StandardInput=null
              StandardOutput=syslog
              StandardError=syslog
              Environment=SANE_CONFIG_DIR=/usr/local/etc/sane.d
              # If you need to debug your configuration uncomment the next line and
              # change it as appropriate to set the desired debug options
              # Environment=SANE_DEBUG_DLL=255 SANE_DEBUG_BJNP=5

              [Install]
              Also=saned.socket

       You need to set an environment variable for SANE_CONFIG_DIR pointing to
       the  directory  where saned can find its configuration files.  you will
       have to remove the # on the last line and set the variables for the de-
       sired debugging information if required.  Multiple variables can be set
       by separating the assignments by spaces as shown in the example above.

       Unlike xinetd(8) and inetd(8), systemd(1) allows debugging output  from
       backends  set using SANE_DEBUG_XXX to be captured. See the man-page for
       your backend to see what options are  supported.  With the service unit
       as  described  above,  the  debugging output is forwarded to the system
       log.


Systemd configuration when saned is compiled without systemd support

       This configuration will also work when  saned  is  compiled  WITH  sys-
       temd(1)integrationsupport,butitdoesnotallowdebugging  information to be
       logged.

       For systemd(1) configuration for saned, we need to add 2  configuration
       files in /etc/systemd/system.

       The first file we need to add here is called saned.socket.  It is iden-
       tical to the version for systemd(1) with the support compiled  in.   It
       shall have the following contents:

              [Unit]
              Description=saned incoming socket

              [Socket]
              ListenStream=6566
              Accept=yes
              MaxConnections=1

              [Install]
              WantedBy=sockets.target

       The second file to be added is saned@.service This one differs from the
       version with systemd(1) integration compiled in:

              [Unit]
              Description=Scanner Service
              Requires=saned.socket

              [Service]
              ExecStart=/usr/sbin/saned
              User=saned
              Group=saned
              StandardInput=socket

              Environment=SANE_CONFIG_DIR=/etc/sane.d

              [Install]
              Also=saned.socket


FILES

       /etc/hosts.equiv
              The hosts listed in this file are permitted to access all  local
              SANE  devices.  Caveat: this file imposes serious security risks
              and its use is not recommended.

       /usr/local/etc/sane.d/saned.conf
              Contains a list of hosts permitted to access local SANE  devices
              (see also description of SANE_CONFIG_DIR below).

       /usr/local/etc/sane.d/saned.users
              If this file contains lines of the form

              user:password:backend

              access  to  the  listed backends is restricted. A backend may be
              listed multiple times for different user/password  combinations.
              The server uses MD5 hashing if supported by the client.


ENVIRONMENT

       SANE_CONFIG_DIR
              This environment variable specifies the list of directories that
              may contain the configuration file.  Under UNIX, the directories
              are  separated  by a colon (`:'), under OS/2, they are separated
              by a semi-colon (`;').  If this variable is not set, the config-
              uration  file is searched in two default directories: first, the
              current  working  directory   (".")   and   then   in   /usr/lo-
              cal/etc/sane.d.   If  the value of the environment variable ends
              with the directory separator character, then the default  direc-
              tories  are searched after the explicitly specified directories.
              For example, setting SANE_CONFIG_DIR to "/tmp/config:" would re-
              sult in directories tmp/config, ., and /usr/local/etc/sane.d be-
              ing searched (in this order).


SEE ALSO

       sane(7),    scanimage(1),    xscanimage(1),    xcam(1),    sane-dll(5),
       sane-net(5), sane-"backendname"(5), inetd(8), xinetd(8), systemd(1),
       http://www.penguin-breeder.org/?page=sane-net


AUTHOR

       David Mosberger

                                  29 Sep 2017                         saned(8)

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