[CFR] reflect resolv.conf update to running application

[Matthew N. Dodd]

On Fri, 26 Aug 2005, Brooks Davis wrote:
> On Fri, Aug 26, 2005 at 08:29:39PM -0400, Matthew N. Dodd wrote:
>> I've got modifications to dhclient-script and a Makefile in /etc/namedb/
>> that implement this behavior.  I'll clean it up for public consumption if
>> others are interested.
>
> Sounds useful to me.

I've not yet come up with a good way to configure this behavior, other 
than the bit that turns of the resolv.conf updating (touch 
/etc/dhclient-no-resolv-conf).

/var/run/named.forwarders is updated with a Bind named.conf forwarders 
configuration section containing all DHCP provided nameservers.  The 
Makefile is placed in /etc/namedb and /etc/namedb/named.conf is moved to 
/etc/named.conf.in and modified to include the lines:

 	forward only;
#include "/var/run/named.forwarders"

This will cause the nameserver to never perform recursive queries directly 
but to forward everything to the listed forwarders.

I'm open to suggestions on where to place the configuration knobs for this 
functionality.

-- 
10 40 80 C0 00 FF FF FF FF C0 00 00 00 00 10 AA AA 03 00 00 00 08 00
-------------- next part --------------
Index: dhclient-script
===================================================================
RCS file: /home/cvs/src/sbin/dhclient/dhclient-script,v
retrieving revision 1.5
diff -u -u -r1.5 dhclient-script
--- dhclient-script	26 Jul 2005 18:27:37 -0000	1.5
+++ dhclient-script	12 Aug 2005 15:10:33 -0000
@@ -128,6 +128,23 @@
 	fi
 }
 
+make_named_forwarders() {
+	if [ -z "$new_domain_name_servers" ]; then
+		return 1
+	fi
+
+	rm -f /var/run/named.forwarders
+	echo "	forwarders {" > /var/run/named.forwarders
+	for nameserver in $new_domain_name_servers; do
+		echo "		$nameserver;" >> /var/run/named.forwarders
+	done
+	echo "	};" >> /var/run/named.forwarders
+
+	cd /etc/namedb && make
+
+	return 0
+}
+
 add_new_resolv_conf() {
 	# XXX Old code did not create/update resolv.conf unless both
 	# $new_domain_name and $new_domain_name_servers were provided.  PR
@@ -135,6 +152,10 @@
 	# thus broke the script. This code creates the resolv.conf if either
 	# are provided.
 
+	if [ -f /etc/dhclient-no-resolv-conf ]; then
+		return 0
+	fi
+
 	rm -f /etc/resolv.conf.std
 
 	if [ -n "$new_domain_name" ]; then
@@ -240,6 +261,7 @@
 		add_new_alias
 	fi
 	add_new_resolv_conf
+	make_named_forwarders
 	;;
 
 EXPIRE|FAIL)
@@ -267,6 +289,7 @@
 				add_new_alias
 			fi
 			add_new_routes
+			make_named_forwarders
 			if add_new_resolv_conf; then
 				exit_with_hooks 0
 			fi
-------------- next part --------------
# $Id$
#

named.conf: named.conf.in /var/run/named.forwarders
	cpp -P -C named.conf.in > $@
	/etc/rc.d/named restart