Minor changes to DHCP support; Dave was having problems with how

I was getting the IP from the hostname, so I switched to the trick
we use on the testbed nodes; use /etc/dhclient-exit-hooks to write
the data into /var/run, and use that in register.sh when the IP=DHCP.

cdrom/waboot/netbed-setup.pl

@@ -154,22 +154,11 @@ else {
     fatal("Tainted hostname $hostname!");
 }
 
-#
-# If DHCP mode, must get our IP from the hostname first. Perhaps we
-# should do that all the time, as a check on the nameserver, which had
-# better be correct and working!
-#
-if ($IP eq "DHCP") {
-    my (undef,undef,undef,undef,@ipaddrs) = gethostbyname($hostname);
-    $IP = inet_ntoa($ipaddrs[0]);
-}
-
-# Now taint check IP.
 if ($IP =~ /^(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})$/) {
     $IP = $1;
 }
 else {
-    fatal("Tainted value $IP!");
+    fatal("Bad IP: $IP!");
 }
 
 #

cdrom/waboot/register.pl

@@ -112,7 +112,7 @@ if ($IP eq "DHCP") {
 	$IP = inet_ntoa($ipaddrs[0]);
     }
     else {
-
+	fatal("Invalid hostname: $hostname");
     }
 }
 	

cdrom/waboot/register.sh

 #!/bin/sh
 #
 # EMULAB-COPYRIGHT
-# Copyright (c) 2000-2002 University of Utah and the Flux Group.
+# Copyright (c) 2000-2003 University of Utah and the Flux Group.
 # All rights reserved.
 #
 
@@ -14,6 +14,11 @@
 
 . /etc/rc.conf.local
 
+if [ "$netbed_IP" = "DHCP" ]; then
+	# See /etc/dhclient-exit-hooks
+	netbed_IP=`cat /var/run/myip`    
+fi
+
 case "$1" in
 start)
 	if [ -f /usr/site/sbin/register.pl ]; then