tunnelme - Split tunnel connections to a specific host or IP over a certain gateway

tunnelme.md

Situation:

Your VPN does not automatically set split tunnel for your connection to some host, maybe the ipaddress of the host changes over time, like an AWS ELB, and network admins can't set split tunnel rules on changing addresses.

Requirements:

User must be able to run:

sudo route add -host "$dst" "$tunnel"

How to use:

1. Download tunnelme.sh

2. chmod +x tunnelme.sh

3. Run script

./tunnelme.sh <host|ipaddress>
     1	 133 x.y.z.f utun1
     2	   3 link#16 utun1
What is your tunnel, (use number): 1
add host host|ipaddress.: gateway x.y.z.f
add host ipaddress: gateway x.y.z.f

tunnelme.sh

#!/bin/bash -eu

dst="$1"

netstat -nr | awk '$6~/tun/{print $2, $6}' | sort | uniq -c | sort -nr > /tmp/tunnelme

cat -n /tmp/tunnelme

read -p "What is your tunnel, (use number): " n

tunnel="$(awk 'NR=='"$n"'{print $2}' /tmp/tunnelme)"

if [ "$(dig +short "$dst")" = "" ]
then
  sudo route add -host "$dst" "$tunnel"
else
  for idst in $(dig +short "$dst")
  do
    sudo route add -host "$idst" "$tunnel"
  done
fi

TODO: add support for Linux.