Script for adding NAT rules for xhyve VMs to subnets behind OpenVPN

xhyve-ovpn-nat.sh

#!/bin/sh

subnets="10.1/16"
rules="/tmp/nat.rules"

echo "Clearing nat table..."
sudo pfctl -a com.apple/tun -F nat

echo "Generaring nat rules..."
echo > $rules
for sub in $subnets; do
  if=`netstat -nr | grep "$sub" | awk -F ' ' '{ print $6 }'`
  echo "nat on ${if} proto {tcp, udp, icmp} from 192.168.64.0/24 to $sub -> ${if}" >> $rules
done

echo "Applying nat rules..."
sudo pfctl -a com.apple/tun -f $rules