#!/bin/sh

#  open an ssh tunnel for tunneling ssh traffic from offsite system
#  
#@(#) nxtunnel 
#-----------------------------------------------------------------------
# Version History
#-----------------------------------------------------------------------
# 1.1 2014/10/10 cuffe@jlab.org  - re-write for acclogin
# 1.0 2010/04/07 cuffe@jlab.org  - inital revision

#-----------------------------------------------------------------------
# Debug variables
#-----------------------------------------------------------------------
# Print shell commands as they are executued
#set -x
# Run the script but do not actually execute any commands
#set -n

#-----------------------------------------------------------------------
# Global Variables
#-----------------------------------------------------------------------

# TUNNEL_HOST is the gateway login server
TUNNEL_HOST=acclogin.jlab.org  

# NX_HOST is the remote system that runs the NX server.
NX_HOST=opsnx.acc.jlab.org
# Other possible NX Hosts
#NX_HOST=devnx.acc.jlab.org
#NX_HOST=chlnx.acc.jlab.org
#NX_HOST=felnx.acc.jlab.org

#-----------------------------------------------------------------------
# Command Variables
#-----------------------------------------------------------------------

SSH=`which ssh`

BIN_LIST="$SSH"

#-----------------------------------------------------------------------
# Functions
#-----------------------------------------------------------------------

function usage {

echo "usage: $0"
echo ""
echo "This script is used to open a tunnel through the jlab acclogin server"
echo "and wait to kill the connection."
echo ""
}

function checkfile {
	if [ ! -f $1 ];then
	echo "Could not find file $1" 
	echo "Please make sure it is installed and in your path"
	exit 1
	fi
	if [ ! -x $1 ];then
	echo "Could not execute file $1" 
	exit 1
	fi
	}

function getuser {
    printf "Username: " 
    read USER
    if [ ! -n "$USER" ];then
    getuser
    fi
}


#-----------------------------------------------------------------------
# Process Options
#-----------------------------------------------------------------------

while getopts ":h" opt; do
    case $opt in
        
	h) usage 
	   exit 0
	   ;;   
       \?) echo "Unknown Option: $opt"
       	   usage
           exit 1
           ;;
        *) echo "Unknown Option: $opt"
	   usage
           exit 1
                ;;      
    esac
done

# The expression $(($OPTIND - 1)) is an arithmetic expression equal to $OPTIND minus 1. 
# This value is used as the argument to shift. The result is that the correct number of 
# arguments are shifted out of the way, leaving the "real" arguments as $1, $2, etc.
shift $(($OPTIND - 1))


#-----------------------------------------------------------------------
# Data File Sanity Check
#-----------------------------------------------------------------------
for BIN in $BIN_LIST 	
	do
	checkfile $BIN
	done

#-----------------------------------------------------------------------
# User Info
#-----------------------------------------------------------------------

getuser

#-----------------------------------------------------------------------
# Open Tunnel and Desktop
#-----------------------------------------------------------------------

echo "Opening ssh tunnel to $NX_HOST through $TUNNEL_HOST for $USER"
echo "Please provide your two-factor credential when asked for a password."
ssh  -l $USER -f -N -C -L 2222:$NX_HOST:22 $TUNNEL_HOST

# Run NX Client

#open -a 'NoMachine'

#-----------------------------------------------------------------------
# Kill any left over tunnels
#-----------------------------------------------------------------------
echo ''
echo 'Waiting to cleanup and kill all tunnels'
echo 'Would you like to kill all tunnels now?'
read RESPONSE
case $RESPONSE in
 	  y* | Y*) 
	  echo ''

for i in `ps -ef | grep ssh | grep $NX_HOST | awk '{print $2}'`
	do
		echo "Killing Tunnel with PID $i" 
 		kill -9 $i 
	done
	;;
	  *)
	  echo "Please manually kill the following tunnels:"
	  echo "ps -ef | grep ssh | grep $NX_HOST"
	  ps -ef | grep ssh | grep $NX_HOST 
	  exit 0
	  ;;
esac

exit 0