[nut-Feature Requests][310492] Allow to specify hostnames in ACL (upsd.conf)

nut-featurerequests at alioth.debian.org nut-featurerequests at alioth.debian.org
Mon Jan 7 09:19:20 UTC 2008


Feature Requests item #310492, was opened at 2008-01-07 09:57
Status: Open
Priority: 3
Submitted By: Arnaud Quette (aquette)
Assigned to: Nobody (None)
Summary: Allow to specify hostnames in ACL (upsd.conf) 
Category: None
Group: None


Initial Comment:
allow a new ACL form:
ACL hostname/mask

example:
ACL localhost localhost/32
or
ACL localhost localhost/255.255.255.255

This is obviously reserved to names that can be resolved (so host only?)


----------------------------------------------------------------------

>Comment By: Arjen de Korte (adkorte-guest)
Date: 2008-01-07 10:19

Message:
I don't think this is a good idea. Not only because this depends on having DNS setup for the hostnames, but also because there is the problem what we should do when a hostname resolves into multiple IP adresses and/or IPv4/IPv6 adresses. Should we listen on a single adress or all that we can find?

Relying on DNS is very tricky, although we allow this for specifying LISTEN adresses. In the latter case this problem is mitigated because the server simply won't open listening sockets if it can't find an adress to bind to and print an error message. It will do just one or two queries at startup.

There is an additional problem when to do the mapping from hostname to IP adress. If we do it at startup of the server, the hostname (in case of a DHCP client or clients added later on) may not be present yet. This means that we should do a query at connection time (each time a client connects). Besides the load this will cause on the DNS server, the default timeouts for DNS queries (in the order of several seconds) will be too high and clients will start complaining that the server doesn't respond.

----------------------------------------------------------------------

You can respond by visiting: 
http://alioth.debian.org/tracker/?func=detail&atid=411545&aid=310492&group_id=30602



More information about the NUT-tracker mailing list