Bug 824622

Summary:	dhclient-script should honor PEERDNS on quit
Product:	Red Hat Enterprise Linux 6	Reporter:	Mike Burns <mburns>
Component:	dhcp	Assignee:	Jiri Popelka <jpopelka>
Status:	CLOSED ERRATA	QA Contact:	Release Test Team <release-test-team-automation>
Severity:	high	Docs Contact:
Priority:	high
Version:	6.3	CC:	fdeutsch, jpopelka, ljozsa, mburns, mganisin, ovasik, thozza
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	dhcp-4.1.1-33.P1.el6	Doc Type:	Bug Fix
Doc Text:	Cause Any service runs dhclient (either directly or via other service), changes /etc/resolv.conf and sets PEERDNS=no in /etc/sysconfig/network-scripts/ifcfg-<iface> to prevent dhclient from editing /etc/resolv.conf. Then it stops dhclient (directly or via other service). Consequence Dhclient rewrites /etc/resolv.conf with backup even with PEERDNS set to "no". Fix Code for backing up and restoring of /etc/resolv.conf was removed from dhclient-script. Result dhclient doesn't rewrite /etc/resolv.conf when stopped.	Story Points:	---
Clone Of:	824053	Environment:
Last Closed:	2013-02-21 08:23:46 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	824053
Bug Blocks:	824621

Description Mike Burns 2012-05-23 20:39:24 UTC

+++ This bug was initially created as a clone of Bug #824053 +++

Description of problem:
If /etc/resolv.conf is changed while dhclient is running (with PEERDNS=yes), /etc/resolv.conf get's overwritten even if PEERDNS was set to "no" befor it was shutdown.

How reproducible:
Always

Steps to Reproduce:
See bug #822930
  
Actual results:
/etc/resolv.conf is empty (or contains previous data)


Expected results:
/etc/resolv.conf is not touched

Additional info:
This is just a problem if dhclient started with PEERDNS=yes and quits with PEERDNS=no (so the user expects dhclient no to touch resolv.conf)

Comment 1 Mike Burns 2012-05-23 20:48:24 UTC

Comment 1 from 824053:

I already removed this /etc/resolv.conf backup&restore part of dhclient-script in F-17:
http://pkgs.fedoraproject.org/gitweb/?p=dhcp.git;a=commitdiff;h=1e3f54a9ec3e1610b8ad4920c6c6b0c4c80a1e22

I'm closing as fixed in rawhide. Feel free to reopen if you need to have this fixed in F-16.

Comment 5 Jiri Popelka 2012-08-24 14:16:00 UTC

    Technical note added. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    New Contents:
Cause
Any service runs dhclient (either directly or via other service), changes /etc/resolv.conf and sets PEERDNS=no in /etc/sysconfig/network-scripts/ifcfg-<iface> to prevent dhclient from editing /etc/resolv.conf. Then it stops dhclient (directly or via other service).

Consequence
Dhclient rewrites /etc/resolv.conf with backup even with PEERDNS set to "no".

Fix
Code for backing up and restoring of /etc/resolv.conf was removed from dhclient-script.

Result
dhclient doesn't rewrite /etc/resolv.conf when stopped.

Comment 7 Ladislav Jozsa 2012-09-25 15:30:25 UTC

Verified on RHEL6, dhclient-4.1.1-34.P1.el6.x86_64. /etc/resolv.conf isn't modified when PEERDNS set to 'no' and dhclient is stopped.

Comment 8 errata-xmlrpc 2013-02-21 08:23:46 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHSA-2013-0504.html