#!/bin/sh +x

IP=/sbin/ip

SLICE=$1
SLICEID=`id -u $SLICE`
NODEID=$2
KEY=$3

modprobe etun

###
### Avoid IP address collisions between NAT and virtual links.
### Virtual links have addresses 10.A.B.[23], where A < B always.
### So make sure that A > B for NAT.
###
if [ $KEY > $NODEID ]; then
    BASE="10.$KEY.$NODEID"
else
    BASE="10.$NODEID.$KEY"
fi

### Setup etun
ETUN0=nat$KEY
ETUN1=natx$KEY
echo $ETUN0,$ETUN1 > /sys/module/etun/parameters/newif
ifconfig $ETUN1 $BASE.1 up

/sbin/iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
/sbin/iptables -A FORWARD -i eth0 -o $ETUN1 -m state --state RELATED,ESTABLISHED -j ACCEPT
/sbin/iptables -A FORWARD -i $ETUN1 -o eth0 -j ACCEPT

### Put a process in the vserver so we can move the interface there
su $SLICE -c "sleep 30" &
sleep 1
PID=`su $SLICE -c "pgrep sleep"`
chcontext --ctx 1 -- echo $PID > /sys/class/net/$ETUN0/new_ns_pid 
sleep 1

su $SLICE -c "sudo /sbin/ifconfig $ETUN0 $BASE.2/24 up; \
 sudo /sbin/route add -net $BASE.0/24 $ETUN0; \
 sudo /sbin/route add default gw $BASE.1"