Launches shuttle on untrusted networks.

pvpn

#!/bin/bash
#
# Launches sshuttle if you're on an untrusted network, currently only available on OS X.
# Patches for Linux support welcome!
#
# sshutle: Transparent proxy server that works as a poor # man's VPN.
# Forwards over ssh. Doesn't require admin. Works with Linux and MacOS. Supports DNS tunneling.
# https://github.com/apenwarr/sshuttle
# 
# Dependencies
#
#   ack
#   awk
#   sshuttle
#   curl (if you use -i flag)
# 
# Intallation
#
# Currently only available on OS X, requires the Airport CLI, put it in your path by issueing:
#     sudo ln -s /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport /usr/sbin/airport
#
# Put this script in your $PATH, and clone sshuttle into your $PATH with:
#     git clone https://github.com/apenwarr/sshuttle.git
#
# Make sure sshuttle works for you without pvpn, test with:
#     curl -s ip.appspot.com && ./sshuttle -r username@sshserver 0.0.0.0/0 -vv && curl -s ip.appspot.com
#
# Launch pvpn with your SSH server as argument, as well as a your trusted networks, example:
#     pvpn -s username@sshserver -t home-wifi-name -t work-wifi-name
#
# Still need to figure out how to put this in a Network hook on OS X, until then, run this in a cron job,
# or figure it out and tell me here!

help_pvpn() {
  echo "Usage for pvpn"
  echo "Arguments:"
  echo " -s <server> server to tunnel through, e.g. user@server.com"
  echo "Optional arguments:"
  echo " -i show ip before and after launch of sshutle"
  echo " -h show this"
  echo " -t <name> trusted network, pass this an artbitary number of times for multiple"
  exit 1
}

check_ip() {
  if [ $SHOW_IP == true ]; then
    echo "pvpn: getting remote ip.."
    [[ $1 == 'sleep' ]] && sleep 1 # let sshuttle do its magic first
    echo "pvpn: current remote ip: `curl -s ip.appspot.com`"
  fi
}

SERVER=''
SSID_NAME=`airport -I | awk '/[^B]SSID/ { print $2 }'`
ALLOWED_SSIDS=()
SHOW_IP=false

while getopts "ht:s:i" OPTION
do
  case $OPTION in
    s) SERVER=$OPTARG ;;
    i) SHOW_IP=true ;;
    h) help_pvpn ;;
    t) ALLOWED_SSIDS=( ${ALLOWED_SSIDS[@]-} $(echo $OPTARG) ) ;;
  esac
done

echo "pvpn: current network name: $SSID_NAME"
echo "pvpn: allowed networks: ${ALLOWED_SSIDS[*]}"

# By default, network's not allowed
ALLOW=false

# Check if network is allowed
for ssid in ${ALLOWED_SSIDS[@]}; do
  [[ $ssid == $SSID_NAME ]] && ALLOW=true;
done

if [[ $SERVER == '' ]]; then
  echo 'pvpn: server not set, see -h'
  exit 0
fi

# If not allowed, sshuttle us!
if [ $ALLOW == false ]; then
  check_ip
  echo 'pvpn: in unallowed network! sshutling..'
  sshuttle-src/sshuttle -r $SERVER 0.0.0.0/0 -D

  check_ip 'sleep'
else
  echo 'pvpn: on allowed network'
fi