if $ntpd_chrootdir != "", ensure that the following files, devices,

and links exist:
        ${ntpd_chrootdir}/dev/clockctl
        /var/db/ntp.drift -> ${ntpd_chrootdir}/var/db/ntp.drift
and then start ntpd with the appropriate options to run chroot(2)ed
under $ntpd_chrootdir as user ntpd group ntpd.

to take advantage of this, set ntpd_chrootdir in /etc/rc.conf.

[this is based on similar work i did for rc.d/named]

etc/rc.d/ntpd

@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# $NetBSD: ntpd,v 1.3 2000/09/19 13:04:39 lukem Exp $
+# $NetBSD: ntpd,v 1.4 2002/01/18 10:51:30 lukem Exp $
 #
 
 # PROVIDE: ntpd
@@ -12,7 +12,34 @@ name="ntpd"
 rcvar=$name
 command="/usr/sbin/${name}"
 pidfile="/var/run/${name}.pid"
+start_precmd="ntpd_precmd"
 required_files="/etc/ntp.conf"
 
+ntpd_precmd()
+{
+	if [ -z "$ntpd_chrootdir" ]; then
+		return 0;
+	fi
+
+	# If running in a chroot cage, ensure that the appropriate files
+	# exist inside the cage, as well as helper symlinks into the cage 
+	# from outside.
+	#
+	# As this is called after the is_running and required_dir checks
+	# are made in run_rc_command(), we can safely assume ${ntpd_chrootdir}
+	# exists and ntpd isn't running at this point (unless forcestart
+	# is used).
+	#
+	if [ ! -c "${ntpd_chrootdir}/dev/clockctl" ]; then
+		rm -f "${ntpd_chrootdir}/dev/clockctl"
+		( cd /dev ; /bin/pax -rw -pe clockctl "${ntpd_chrootdir}/dev" )
+	fi
+	ln -fs "${ntpd_chrootdir}/var/db/ntp.drift" /var/db/ntp.drift
+
+	#	Change run_rc_commands()'s internal copy of $ntpd_flags
+	#
+	_flags="-u ntpd:ntpd -i ${ntpd_chrootdir} $_flags"
+}
+
 load_rc_config $name
 run_rc_command "$1"