kern/156259: [patch] IPv6 DNS autoconfiguration (RFC6106 RDNSS and DNSSL)

[J.R. Oldroyd]

>Number:         156259
>Category:       kern
>Synopsis:       [patch] IPv6 DNS autoconfiguration (RFC6106 RDNSS and DNSSL)
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          change-request
>Submitter-Id:   current-users
>Arrival-Date:   Thu Apr 07 21:00:24 UTC 2011
>Closed-Date:
>Last-Modified:
>Originator:     J.R. Oldroyd
>Release:        FreeBSD 8.2-RELEASE amd64
>Organization:
>Environment:
System: FreeBSD xx.opal.com 8.2-RELEASE FreeBSD 8.2-RELEASE #0: Thu Feb 17 02:41:51 UTC 2011 root at mason.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC amd64
>Description:
When using IPv6 stateless autoconfiguration (SLAAC), FreeBSD only
configures the interface's IPv6 address and does not configure the
DNS server or DNS search domain(s).  This means a system using 
IPv6 SLAAC must obtain its DNS server and domain information using
other means or must rely on IPv4 nameservice.

RFC proposal 5006 and the later draft standard RFC 6106 describe
extensions to the IPv6 ICMP6 router advertisement (RA) protocol
to add DNS server and DNS search domain information, known as the
RDNSS and DNSSL router advertisement options.

The patches offered here implement RFC 6106 by means of:

	1. extensions to rtadvd(8) to parse configuration for
	   and to send RA RDNSS and DNSSL options

	2. extensions to rtsold(8) to accept these options

	3. a new script /sbin/resolvconf to manage the DNS
	   options, their expiry, and their addition to the
	   system's resolver configuration file, /etc/resolv.conf

	4. changes to dhclient(8)'s /sbin/dhclient-script to also
	   use the new /sbin/resolvconf script so that IPv6 DNS
	   updates from rtsold and IPv4 DNS updates from dhclient
	   can co-exist peacefully

These patches were frist made known on freebsd-net@ here:

	http://lists.freebsd.org/pipermail/freebsd-net/2011-March/028299.html

and have been downloaded 10-15 times per week since then.
>How-To-Repeat:
n/a
>Fix:
Obtain the four patches from the web page:

	http://opal.com/jr/freebsd/rdnss/

>Release-Note:
>Audit-Trail:
>Unformatted: