saned.8



saned(8)                 SANE Scanner Access Now Easy                 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 con‐
       nection 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 tcp‐
       wrappers 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 permit‐
       ted. 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  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  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 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=/etc/sane.d SANE_DEBUG_DLL=255

       Is you need to set an environment variable  for  saned  like  SANE_CON
       FIG_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 config‐
              uration 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  sepa‐
              rator 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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