saned(8)


NAME

   saned - SANE network daemon

SYNOPSIS

   saned [ -a [ username ] | -d [ n ] | -s [ n ] | -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  -a flag requests that saned run in standalone daemon mode. In this
   mode, saned will detach from the console and  run  in  the  background,
   listening  for  incoming  client connections; inetd is not required for
   saned operations in this mode. If the optional username is given  after
   -a , saned will drop root privileges and run as this user (and group).

   The -d and -s flags request that saned run in debug mode (as opposed to
   inetd(8) daemon mode).  In this mode,  saned  explicitly  waits  for  a
   connection  request.  When compiled with debugging enabled, these flags
   may be followed by a number to  request  debug  info.  The  larger  the
   number,  the  more  verbose the debug output.  E.g., -d128 will request
   printing of all debug info. Debug level 0 means no debug output at all.
   The  default value is 2. If flag -d is used, the debug messages will be
   printed to stderr while -s requests using syslog.

   If saned is run from inetd, xinetd or systemd, no option can be given.

   The -h flag displays a short help message.

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
   tcpwrappers and/or a firewall setup. Don't depend only on  saned's  own
   authentication.  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.

   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
   addresses 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 hostname. 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 (x)inetd or systemd.
   (see  below).   Note  that  your inetd must support IPv6 if you want to
   connect to saned over IPv6 ;  xinetd,  openbsd-inetd  and  systemd  are
   known to support IPv6, check the documentation for your inetd daemon.

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

   For the configurations below it is 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.

INETD CONFIGURATION

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

   The configuration line normally looks like this:

          sane-port stream tcp nowait saned.saned /usr/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
   instead:

          sane-port   stream   tcp   nowait   saned.saned   /usr/sbin/tcpd
          /usr/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
   scanner devices).

XINETD CONFIGURATION

   If  xinetd  is  installed on your system instead of inetd the following
   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/sbin/saned
          }

SYSTEMD CONFIGURATION

   for systemd we need to add 2 configuation 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
   contents:

          [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=/etc/sane.d SANE_DEBUG_DLL=255

   Is  you  need  to  set  an  environment   variable   for   saned   like
   SANE_CONFIG_DIR  you will have to remove the # on the last line and set
   the  variable  appropriately.   Multiple  variables  can  be   set   by
   separating the assignments by spaces as shown in the example above.

   Unlike (x)inetd systemd allows debugging output from backends set using
   SANE_DEBUG_<backend_name> to be captured.  With  the  service  unit  as
   described above, the debugging output is forwarded to the system log.

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.

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

   /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
          configuration file  is  searched  in  two  default  directories:
          first,   the   current  working  directory  (".")  and  then  in
          /etc/sane.d.  If the value of the environment variable ends with
          the  directory separator character, then the default directories
          are searched after the explicitly  specified  directories.   For
          example,  setting SANE_CONFIG_DIR to "/tmp/config:" would result
          in  directories  "tmp/config",  ".",  and  "/etc/sane.d"   being
          searched (in this order).

SEE ALSO

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

AUTHOR

   David Mosberger

                              20 Apr 2009                         saned(8)





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