bin/161733: [patch] fix rc_force check in /etc/rc.d/dhclient

[Eygene Ryabinkin]

>Number:         161733
>Category:       bin
>Synopsis:       [patch] fix rc_force check in /etc/rc.d/dhclient
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Oct 17 06:00:24 UTC 2011
>Closed-Date:
>Last-Modified:
>Originator:     Eygene Ryabinkin
>Release:        FreeBSD 10.0-CURRENT amd64
>Organization:
Code Labs
>Environment:

System: FreeBSD 10.0-CURRENT amd64

>Description:

Revision 226345 of /etc/rc.d/dhclient introduced the number of
sanity checks, but the condition '[ -n "${rc_force}" ]' must be
inversed, because the script should exit if it was _not_ forced
to run and this is not the DHCP interface.  'it was not forced' ==
'[ -z "${rc_force}" ]' and not the other way round.

>How-To-Repeat:

Build and boot FreeBSD 10-CURRENT after 226345 and watch how your
non-DHCP-enabled interfaces are trying to acquire the address via
DHCP (dhclient in my case was invoked from the devd hooks for the
"interface up" event).

>Fix:

Apply patch at
  http://codelabs.ru/fbsd/patches/dhclient/dhclient-properly-check-rc_force.diff

It works both for my DHCP-enabled laptop and non-DHCP-enabled workstation.
>Release-Note:
>Audit-Trail:
>Unformatted: