Bug 227432

Summary:	loader should try multiple ports for DNS queries
Product:	[Fedora] Fedora	Reporter:	Jack Neely <jjneely>
Component:	glibc	Assignee:	Jakub Jelinek <jakub>
Status:	CLOSED INSUFFICIENT_DATA	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	rawhide	CC:	triage
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:	bzcl34nup
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2008-05-07 01:08:16 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Jack Neely 2007-02-05 21:53:48 UTC

Description of problem:

The loader uses a single static port as the source port for its DNS queries. 
This is port 32768 commonly also used by nfs statd on solaris.  Some security
setup require that this port be blocked.

Most DNS resolvers use a random port for security issues (DNS spoofing) and
avoiding firewalls.

Would it be possible to make the loader increment the source port used on DNS
resolver failures or use a random port?

Version-Release number of selected component (if applicable):
All versions of Anaconda

Steps to reproduce:
Use tcpdump to get a packet capture of packets going to your DNS server while
the loader is booting.  It always uses port 32768 (0x8000).

Comment 1 David Cantrell 2007-04-03 19:42:27 UTC

Is there an RFC or reference implementation that defines this port randomization
for DNS queries?

Changing the product to Fedora Core as I will only be able to work on it there.
 If you need this issue addressed in RHEL, contact your TAM.

Comment 2 Jack Neely 2007-04-03 20:13:43 UTC

Its to prevent DNS spoofing...ah here we go, there is a draft RFC for it.

http://www.ietf.org/internet-drafts/draft-ietf-dnsext-forgery-resilience-00.txt

I do need this in RHEL, but being an academic customer we can't have a TAM. 
Touchy subject...

Comment 3 David Cantrell 2008-01-04 04:47:51 UTC

We just use the functions in glibc to do the DNS lookups, so I think this will
have to be something implemented on that end.

Comment 4 Bug Zapper 2008-04-03 19:01:51 UTC

Based on the date this bug was created, it appears to have been reported
against rawhide during the development of a Fedora release that is no
longer maintained. In order to refocus our efforts as a project we are
flagging all of the open bugs for releases which are no longer
maintained. If this bug remains in NEEDINFO thirty (30) days from now,
we will automatically close it.

If you can reproduce this bug in a maintained Fedora version (7, 8, or
rawhide), please change this bug to the respective version and change
the status to ASSIGNED. (If you're unable to change the bug's version
or status, add a comment to the bug and someone will change it for you.)

Thanks for your help, and we apologize again that we haven't handled
these issues to this point.

The process we're following is outlined here:
http://fedoraproject.org/wiki/BugZappers/F9CleanUp

We will be following the process here:
http://fedoraproject.org/wiki/BugZappers/HouseKeeping to ensure this
doesn't happen again.

Comment 5 Bug Zapper 2008-05-07 01:08:14 UTC

This bug has been in NEEDINFO for more than 30 days since feedback was
first requested. As a result we are closing it.

If you can reproduce this bug in the future against a maintained Fedora
version please feel free to reopen it against that version.

The process we're following is outlined here:
http://fedoraproject.org/wiki/BugZappers/F9CleanUp