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
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; in-
etd(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 re-
quest 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.
-h, --help
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) integration support, but it does not allow debugging informa-
tion 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. On *NIX systems, the direc-
tories are separated by a colon (`:'), under OS/2, they are sep-
arated 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 /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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