Patch to prevent multiple dhclients starting on an interface

[David W. Hankins]

On Wed, Jun 15, 2005 at 07:55:15PM +1000, Andrew Pollock wrote:
> Another bug against dhcp-client that's been open for a while in Debian is
> one about starting up multiple dhclients on the same interface.
> 
> http://bugs.debian.org/178885 has the lowdown.

I'm not sure I fully understand what 'ifup --force' "means".  I understand
that one person complaining in that ticket only uses ifup --force because
ifdown unloads the module, but it's not clear to me that is correct or not
(is ifdown resulting in module unloading a bug?), and I don't gather what
the circumstance is for using --force in the first place for the others.

Is this construction, forced by the user, because they know that their
own actions have destructed it?  (In which case having to kill your
dhclient manually sounds like trouble you asked for).

Is this "please refresh my address?"  (In which case, it would be
far easier to either stop/start dhclient or prod the existing daemon in
some manner to elicit that result - there exist already 'hibernate' and
'awaken' control states that do this, which can be acheived through
omapi today, or otherwise would be a trivial excercise in coding to add
signal handlers to set these states...).


I think dhclient pid file handling should be cleaned up either way.

-- 
David W. Hankins		"If you don't do it right the first time,
Software Engineer			you'll just have to do it again."
Internet Systems Consortium, Inc.		-- Jack T. Hankins