#!/bin/sh
#
# Simple script to upgrade Libreswan on Ubuntu and Debian
#
# Copyright (C) 2015 Lin Song
#
# This work is licensed under the Creative Commons Attribution-ShareAlike 3.0
# Unported License: http://creativecommons.org/licenses/by-sa/3.0/
#
# Attribution required: please include my name in any derivative and let me
# know how you have improved it!

SWAN_VER=3.16

if [ "$(lsb_release -si)" != "Ubuntu" ] && [ "$(lsb_release -si)" != "Debian" ]; then
  echo "Looks like you aren't running this script on a Ubuntu or Debian system."
  exit 1
fi

if [ "$(sed 's/\..*//' /etc/debian_version 2>/dev/null)" = "7" ]; then
  echo "Sorry, this script does not support Debian 7 (Wheezy)."
  exit 1
fi

if [ "$(id -u)" != 0 ]; then
  echo "Sorry, you need to run this script as root."
  exit 1
fi

ipsec --version 2>/dev/null | grep -qs "Libreswan"
if [ "$?" != "0" ]; then
  echo "This upgrade script requires that you already have Libreswan installed."
  echo "Aborting."
  exit 1
fi

ipsec --version 2>/dev/null | grep -qs "Libreswan ${SWAN_VER}"
if [ "$?" = "0" ]; then
  echo "You already have Libreswan ${SWAN_VER} installed! "
  echo
  read -r -p "Do you wish to continue anyway? [y/N] " response
  case $response in
    [yY][eE][sS]|[yY])
      echo
      ;;
    *)
      echo "Aborting."
      exit 1
      ;;
  esac
fi

echo "Welcome! This upgrade script will build and install Libreswan ${SWAN_VER} on your server."
echo "This is intended for use on VPN servers with an older version of Libreswan installed."
echo "Your existing VPN configuration files will NOT be modified."

echo
read -r -p "Do you wish to continue? [y/N] " response
case $response in
  [yY][eE][sS]|[yY])
    echo
    echo "Please be patient. Setup is continuing..."
    echo
    ;;
  *)
    echo "Aborting."
    exit 1
    ;;
esac

# Create and change to working dir
mkdir -p /opt/src
cd /opt/src || { echo "Failed to change working directory to /opt/src. Aborting."; exit 1; }

# Update package index and install wget and nano
export DEBIAN_FRONTEND=noninteractive
apt-get -y update
apt-get -y install wget nano

# Install necessary packages
apt-get -y install libnss3-dev libnspr4-dev pkg-config libpam0g-dev \
        libcap-ng-dev libcap-ng-utils libselinux1-dev \
        libcurl4-nss-dev libgmp3-dev flex bison gcc make \
        libunbound-dev libnss3-tools libevent-dev
apt-get -y --no-install-recommends install xmlto
apt-get -y install xl2tpd

# Compile and install Libreswan (https://libreswan.org/)
SWAN_URL=https://download.libreswan.org/libreswan-${SWAN_VER}.tar.gz
/bin/rm -rf "/opt/src/libreswan-${SWAN_VER}"
wget -t 3 -T 30 -qO- $SWAN_URL | tar xvz
[ ! -d libreswan-${SWAN_VER} ] && { echo "Could not retrieve Libreswan source files. Aborting."; exit 1; }
cd libreswan-${SWAN_VER}
make programs && make install

ipsec --version 2>/dev/null | grep -qs "Libreswan ${SWAN_VER}"
if [ "$?" != "0" ]; then
  echo
  echo "Sorry, something went wrong."
  echo "Libreswan ${SWAN_VER} was NOT installed successfully."
  echo "Exiting script."
  exit 1
fi

service ipsec restart
service xl2tpd restart

echo
echo "Congratulations! Libreswan ${SWAN_VER} was installed successfully!"

exit 0