Ubuntu Manpage: saned - SANE network daemon

NAME

       saned - SANE network daemon

SYNOPSIS

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

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

saned recognises the following options:

-a [username], --alone[=username]
is equivalent to the combination of -l -D -u username options. However, username is
optional and running user will only be set when specified.

-u username, --user=username
requests that saned drop root privileges and run as the user (and group) associated
with username after binding.

-b address, --bind=address
tells saned to bind to the address given.

-p port, --port=port
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).

-l, --listen
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.

-D, --daemonize
will request saned to detach from the console and run in the background.

-o, --once
requests that saned exits after the first client disconnects. This is useful for
debugging.

-d n, --debug=n
sets the level of saned debug output to n. 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.

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

-B, --buffer-size=buffer-size
specifies the size of the read buffer used for communication with the backend in
KB. Default value is 1MB.

-h, --help
displays a short help message.

CONFIGURATION

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 default 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 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.

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.   On  *NIX  systems,  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).

NOTES

       saned does not provide confidentiality  when  communicating  with  clients.  If  saned  is
       exposed  directly  on the network, other users may be able to intercept scanned images, or
       learn passwords for connecting to saned, with little effort. Client systems should connect
       to saned through a secure tunnel to the server instead.

       saned is not a trusted program and should not run with root privileges.

       Refer to /usr/share/doc/libsane/saned/saned.install.md for details on configuring saned as
       a service.

AUTHOR

       David Mosberger

                                           29 Sep 2017                                   saned(8)