#!/bin/bash
# sshconf - ssh servers configuration utility - version 1.1 - July 11
# Copyright 2011 Giuseppe Cuccu, http://www.idsia.ch/~giuse all rights reserved
# Licensed under CC BY-SA 3.0 http://creativecommons.org/licenses/by-sa/3.0/
# This script is provided AS I USE IT and under constant updating - NO WARRANTY
#
# Configure the variables below (or activate the interactive interface)
# Provide an output file as argument or manually redirect stdout to file
#
# User name is supposed to be the same on all servers, as often the case.
# Empty the proxy field to disable port forwarding configuration (VPN SSH tunneling)
#
# Outputs to stdout (redirect this from shell); alternatively, pass it a file name as argument.


interactive="no"

#       NAME        URL
svlst=" salvia      salvia.idsia.ch 
        copernicio  copernicio.idsia.supsi.ch
        ares        ares.dti.supsi.ch "
proxy=" bastion     bastion.idsia.ch  "

user="cuccu"
port="22"
fwdbaseport="20000"
fwdname="b"


####################################################################################

# If a file name is provided, write output to it
if [ $# -gt 0 ]; then
  if [ -f ${1} ]; then
    mv ${1} ${1}.bkp
    echo "A backup of ${1} has been made in ${1}.bkp." 1>&2
  fi
  exec 1>${1}
fi

# INTERACTIVE INTERFACE
if [ ${interactive} == "yes" ]
then
  svlst=$(zenity --entry --title="Server names" --text="Enter server names" --entry-text="${svlst}")
  user=$(zenity --entry --title="User name" --text="Enter user name" --entry-text="${user}")
  port=$(zenity --entry --title="Port number" --text="Enter port to use" --entry-text="${port}")
fi

confblock(){  
# ${1}: shortname ; ${2}: server ; ${3}: user ; ${4}: port;
  echo " "
  echo "Host ${1}"
  echo "HostName ${2}"
  echo "User ${3}"
  echo "Port ${4}"
}

svblock(){  # $1: server name ; $2: server url
  confblock  "${1}"  "${2}"  "${user}"  "${port}"
}

fwdblock(){  # $1: server name
  fwdport=$(( ${fwdport} + 1 ))
  confblock  "${1}${fwdname}"  "localhost"  "${user}" "${fwdport}"
}

fwdline(){  # $1: url of server to forward
  fwdport=$(( ${fwdport} + 1 ))
  echo "LocalForward ${fwdport} ${1}:${port}"
}

aliasline(){  # $1: server name
  sv=${1}
  set - $(echo ${proxy})
  echo "alias ${sv}${fwdname}='ssh -Nfq ${1}; ssh ${sv}${fwdname}'" \
    >&2 #>> ${HOME}/.bashrc
}


# Set server entries
#for sv in ${svlst}; do svblock "${sv}"; done
set - $(echo ${svlst})
while [ $# -gt 0 ]; do
  svblock ${1} ${2}
  shift 2
done

# If a proxy has been defined, set local port forwarding
if [ -n "${proxy}" ]
then
  svblock ${proxy}
  fwdport="${fwdbaseport}"
#  for sv in ${svlst}; do fwdline "${sv}"; done
  set - ${svlst}
  while [ $# -gt 0 ]; do
    fwdline ${2}
    shift 2
  done

  # Set entries for forwarded ports
  fwdport="${fwdbaseport}"
#  for sv in ${svlst}; do fwdblock "${sv}"; done
  set - ${svlst}
  while [ $# -gt 0 ]; do
    fwdblock ${1}
    shift 2
  done

fi

set - $(echo ${svlst})
echo -e "\nAppend the following to .bashrc for an handy vpn connection shortcut:\n" >&2
while [ $# -gt 0 ]; do
  aliasline ${1}
  shift 2
done


echo -e "\n"

echo -e "\n\tDone!\n" >&2


# TODO:
# - use arrays instead of "set -"