Slightly modified version of Jon's Xen vif script for control net setup.

tmcd/linux/xen/emulab-cnet.in

+#!/bin/sh
+#
+# Invoked by xmcreate script to configure the control network for a vnode.
+# Usage:
+#   emulab-cnet vmid host_ip vnode_name vnode_ip (online | offline)
+#
+# NOTE: vmid should be an integer ID.
+#
+
+#boss=@BOSSNODE_IP@
+#ops=@USERNODE_IP@
+#fs=@FSNODE_IP@
+boss=155.98.32.70
+ops=155.98.33.74
+fs=155.98.33.74
+
+# XXX should be configed
+tmcd_port=7777
+slothd_port=8509
+evproxy_port=16505
+LOGDIR=/var/emulab/logs
+
+if [ $# < 3 ]; then
+    echo "usage: $0 vmid host_ip vnode_name vnode_ip [ other_args ]"
+    exit 1
+fi
+
+# $vif comes from the environment
+vmid=$1; shift
+host_ip=$1; shift
+vhost_id=$1; shift
+vif_ip=$1; shift
+local_tmcd_port=`expr $tmcd_port \+ $vmid`
+
+#echo "(vif=$vif), vmid=$vmid, host_ip=$host_ip, vnode_name=$vhost_id, vnode_ip=$vif_ip, other=$*" > /tmp/args
+
+# xen's configuration for a vif
+sh /etc/xen/scripts/vif-bridge $*
+
+cleanup="/tmp/cleanup-$vhost_id"
+
+do_offline() {
+    sh $cleanup
+    rm -f $cleanup
+}
+
+do_online() {
+    echo "# Cleanup script for $vif in vhost $vhost_id" >> $cleanup
+    echo "# created `date`" >> $cleanup
+
+    # prevent dhcp requests from reaching eth0
+    /sbin/iptables -A OUTPUT -j DROP -o $vif -m pkttype --pkt-type broadcast -m physdev --physdev-out $vif
+    echo "/sbin/iptables -D OUTPUT -j DROP -o $vif -m pkttype --pkt-type broadcast -m physdev --physdev-out $vif" >> $cleanup
+
+    # reroute tmcd calls to the proxy on the physical host
+    /sbin/iptables -t nat -A PREROUTING -j DNAT -p tcp --dport $tmcd_port -d $boss -s $vif_ip --to-destination $host_ip:$local_tmcd_port
+    /sbin/iptables -t nat -A PREROUTING -j DNAT -p udp --dport $tmcd_port -d $boss -s $vif_ip --to-destination $host_ip:$local_tmcd_port
+
+    echo "/sbin/iptables -t nat -D PREROUTING -j DNAT -p tcp --dport $tmcd_port -d $boss -s $vif_ip --to-destination $host_ip:$local_tmcd_port" >> $cleanup
+    echo "/sbin/iptables -t nat -D PREROUTING -j DNAT -p udp --dport $tmcd_port -d $boss -s $vif_ip --to-destination $host_ip:$local_tmcd_port" >> $cleanup
+
+    # start a tmcc proxy (handles both TCP and UDP)
+    /usr/local/etc/emulab/tmcc.bin -d -n $vhost_id -X $host_ip:$local_tmcd_port -s $boss -p $tmcd_port -o $LOGDIR/tmccproxy.$vhost_id.log &
+    echo "kill $!" >> $cleanup
+
+    # slothd
+    /sbin/iptables -t nat -A POSTROUTING -j SNAT -p udp --dport $slothd_port --to-source $host_ip -s $vif_ip --destination $boss -o eth0
+    echo "/sbin/iptables -t nat -D POSTROUTING -j SNAT -p udp --dport $slothd_port --to-source $host_ip -s $vif_ip --destination $boss -o eth0" >> $cleanup
+
+    # route mount points and evproxy server
+    # todo: only forward ports the mount server needs (use rpcinfo on fs node)
+    # todo: also only route back to the vif ip 
+    /sbin/iptables -t nat -A POSTROUTING -j SNAT --to-source $host_ip -s $vif_ip --destination $fs -o eth0
+    echo "/sbin/iptables -t nat -D POSTROUTING -j SNAT --to-source $host_ip -s $vif_ip --destination $fs -o eth0" >> $cleanup
+
+    # reroute evproxy packets
+    /sbin/iptables -t nat -A PREROUTING -j DNAT -p tcp --dport $evproxy_port -d $ops -s $vif_ip --to-destination $host_ip:$evproxy_port
+    echo "/sbin/iptables -t nat -D PREROUTING -j DNAT -p tcp --dport $evproxy_port -d $ops -s $vif_ip --to-destination $host_ip:$evproxy_port" >> $cleanup
+}
+
+case "$1" in
+    'online')
+        do_online
+    ;;
+    'offline')
+        do_offline
+    ;;
+esac
+exit 0