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)