UPSD.CONF(5) Network UPS Tools (NUT) UPSD.CONF(5)
upsd.conf - Configuration for Network UPS Tools upsd
upsd uses this file to control access to the server and set some other miscellaneous con-
figuration values. This file will contain passwords for your upsmon(8) clients, so keep
it secure. Ideally, only the upsd process should be able to read it.
ACCESS CONTROL CONFIGURATION
ACL name netblock
Define an Access Control List (ACL) called name that contains the network netblock.
The netblock can be either the old style, such as this for a traditional "class C":
ACL mynet 192.168.50.0/255.255.255.0
Or, you can use new-style "CIDR format":
ACL mynet 192.168.50.0/24
To just list one host, it would look like one of these:
ACL mybox 192.168.50.1/255.255.255.255
ACL mybox 192.168.50.1/32
ACLs are used whenever you need to refer to a network or host, such as in ACCESS
definitions (below) and with "allowfrom" in upsd.users(5).
ACCESS action level aclname [password]
Define the access to commands at level level by clients in the network defined by
ACL aclname, optionally requiring a password password.
The action can be one of three values:
grant - allow the clients to perform commands at this level.
deny - deny the clients access to commands at this level.
drop - like deny, but don't even respond to their query.
The level relates to the complexity of the command. More important functions like
editing variables inside the UPS require more privileges than merely checking the
status. Each level includes the powers of the one before it. Here are the valid
base - Allows TCP connections and very simple queries. Valid commands are VER
monitor - "base", plus the ability to fetch variables from the UPS. Valid
commands are LISTRW, LISTVARS, and REQ.
login - Deprecated. Implies monitor and base. This is used by old versions
of upsmon in slave mode. Newer versions of upsmon (1.1 and up) that send usernames
are granted access in upsd.users(5).
master - Deprecated. Implies login, monitor and base. Used by old versions
in master mode. See login above.
all - match any level. This really only should be used for "drop all all" or
similar. Granting "all" access to any host is not recommended.
The aclname is just one of your ACL definitions, as explained above.
The password is only used for "login" or "master", and should not be set for lower
ACCESS CONTROL EXAMPLES
Here is an example configuration to show some of what is possible.
- "bigserver" has a UPS attached to a serial port. It runs the driver, upsd, and
upsmon in master mode. This definition is also referenced with an "allowfrom" in
- "workstation" draws from the same UPS as "bigserver", but has to monitor it over
the network. It runs upsmon in slave mode. It is also referenced with an "allowfrom" in
- "webserver" doesn't get power from this UPS at all, but it runs the CGI programs so
it can make nice status displays.
- an abuser is silently dropped
- everyone not yet covered is denied nicely
ACL bigserver 10.20.30.1/32
ACL workstation 10.20.30.2/32
ACL webserver 10.20.30.3/32
ACL abuser 192.168.255.128/32
ACL all 0.0.0.0/0
ACCESS grant monitor bigserver
ACCESS grant monitor workstation
ACCESS grant monitor webserver
ACCESS drop all abuser
ACCESS deny all all
ACCESS CONTROL MATCHING
Access controls should go from most specific to least specific. The first match with a
sufficient access level is the one used when applying permissions.
Along the same lines, everyone is a member of "all", but we want to match everything else
first so they don't hit the deny at the bottom.
If you don't have a final "all" match at the bottom, it will force one for you as a deny.
This means that you have to explicitly add an allow in order to allow the whole world to
Just think of it as a big repeating "if-then-else" structure.
OTHER CONFIGURATION DIRECTIVES
upsd usually allows the data from a driver to go up to 15 seconds without an update
before declaring it "stale". If your driver can't reliably update the data that
often but is otherwise working, you can use MAXAGE to make upsd wait longer.
You should only use this if your driver has difficulties keeping the data fresh
within the normal 15 second interval. Watch the syslog for notifications from upsd
Tell upsd to look for the state files in path rather than the default that was com-
piled into the program.
upsd(8), nutupsdrv(8), upsd.users(5)
The NUT (Network UPS Tools) home page: http://www.exploits.org/nut/
NUT mailing list archives and information: http://lists.exploits.org/
Wed Oct 16 2002 UPSD.CONF(5)