PIA port forwarding with Linux ifconfig alternatives

port_forward.sh

#! /bin/bash
#
# Enable port forwarding
#
# Requirements:
#   your Private Internet Access user and password as arguments
#
# Usage:
#  ./port_forward.sh <user> <password>

error( )
{
  echo "$@" 1>&2
  exit 1
}

error_and_usage( )
{
  echo "$@" 1>&2
  usage_and_exit 1
}

usage( )
{
  echo "Usage: `dirname $0`/$PROGRAM <user> <password>"
}

usage_and_exit( )
{
  usage
  exit $1
}

version( )
{
  echo "$PROGRAM version $VERSION"
}

port_forward_assignment( )
{
  echo 'Loading port forward assignment information..'
  if [ "$(uname)" == "Linux" ]; then
    if type ip >/dev/null 2>/dev/null; then
      local_ip=`ip addr show tun0 |  grep "inet " | head -n 1 | sed 's/^ *//g' | cut -d\  -f2 | tee /tmp/vpn_ip`
    elif ifconfig tun0 | grep -oE "inet addr: "; then
      local_ip=`ifconfig tun0 | grep -oE "inet addr: *10\.[0-9]+\.[0-9]+\.[0-9]+" | tr -d "a-z :" | tee /tmp/vpn_ip`
    else
      local_ip=`ifconfig tun0 | grep "inet " | sed 's/^ *//g' | cut -d\  -f2 | tee /tmp/vpn_ip`
    fi
    client_id=`head -n 100 /dev/urandom | md5sum | tr -d " -"`
  fi
  if [ "$(uname)" == "Darwin" ]; then
    local_ip=`ifconfig tun0 | grep "inet " | cut -d\  -f2|tee /tmp/vpn_ip`
    client_id=`head -n 100 /dev/urandom | md5 -r | tr -d " -"`
  fi
  json=`wget -q --post-data="user=$USER&pass=$PASSWORD&client_id=$client_id&local_ip=$local_ip" -O - 'https://www.privateinternetaccess.com/vpninfo/port_forward_assignment' | head -1`
  echo $json
}

EXITCODE=0
PROGRAM=`basename $0`
VERSION=1.0
USER=$1
PASSWORD=$2

while test $# -lt 2
do
  case $1 in
  --usage | --help | -h )
    usage_and_exit 0
    ;;
  --version | -v )
    version
exit 0
    ;;
  *)
    error_and_usage "Unrecognized option: $1"
    ;;
  esac
  shift
done

port_forward_assignment

exit 0

This revision keeps the client_id constant so the script always returns the same port on the same connection.

Thank you for this... I'm not an expert at shell scripting syntax and your work saved me a lot of looking stuff up to convert the old PIA script for use with ip instead of ifconfig (after installing Debian Stretch I just didn't want to go backwards).