saned
Section: SANE Scanner Access Now Easy (8)
Updated: 29 Sep 2017
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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;
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.
- -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 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.
- 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.
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 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(8)
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(8)
is installed on your system instead of
inetd(8)
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
saned
can be compiled with explicit
systemd(1)
support. This
will allow logging debugging information to be forwarded
to the
systemd(1)
journal. 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 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
# 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 desired 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
systemd(1)
integration support, but it does not allow debugging information 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 identical 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.
- /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).
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
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- OPTIONS
-
- CONFIGURATION
-
- SERVER DAEMON CONFIGURATION
-
- INETD CONFIGURATION
-
- XINETD CONFIGURATION
-
- SYSTEMD CONFIGURATION
-
- Systemd configuration for saned with systemd support compiled in
-
- Systemd configuration when saned is compiled without systemd support
-
- FILES
-
- ENVIRONMENT
-
- SEE ALSO
-
- AUTHOR
-
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Time: 06:02:58 GMT, March 29, 2024