saned
SANE network daemon
see also :
scanimage
Synopsis
saned [
-a [ username ] | -d [ n
] | -s [ n ] ]
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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) mode). In this mode, saned explicitly
waits for a connection 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 or xinetd, no option can be given.
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.
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.
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
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).
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.
inetd configuration
For saned to work properly in its default mode of
operation, it is also necessary to add a configuration line to
/etc/inetd.conf. Note that your inetd must support IPv6 if
you want to connect to saned over IPv6 ; xinetd and openbsd-inetd
are known to support IPv6, check the documentation for your inetd
daemon.
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).
If xinetd is installed on your system instead of inetd the
following example for 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
}
Finally, it is also 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.
see also
sane,
scanimage , xscanimage, xcam,
sane-dll, sane-net,
sane-"backendname"
http://www.penguin-breeder.org/?page=sane-net
author
David
Mosberger