#!/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!

# Check https://libreswan.org and update version number if necessary
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 [ -f "/proc/user_beancounters" ]; then
  echo "Sorry, this script does NOT support OpenVZ VPS. Try Nyr's OpenVPN script instead:"
  echo "https://github.com/Nyr/openvpn-install"
  exit 1
fi

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

/usr/local/sbin/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

clear

/usr/local/sbin/ipsec --version 2>/dev/null | grep -qs "Libreswan ${SWAN_VER}"
if [ "$?" = "0" ]; then
  echo "You already have Libreswan ${SWAN_VER} installed! "
  echo
  printf "Do you wish to continue anyway? [y/N] "
  read -r 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
printf "Do you wish to continue? [y/N] "
read -r 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_FILE="libreswan-${SWAN_VER}.tar.gz"
SWAN_URL="https://download.libreswan.org/${SWAN_FILE}"
wget -t 3 -T 30 -nv -O "$SWAN_FILE" "$SWAN_URL"
[ ! -f "$SWAN_FILE" ] && { echo "Could not retrieve Libreswan source file. Aborting."; exit 1; }
/bin/rm -rf "/opt/src/libreswan-${SWAN_VER}"
tar xvzf "$SWAN_FILE" && rm -f "$SWAN_FILE"
cd "libreswan-${SWAN_VER}" || { echo "Failed to enter Libreswan source directory. Aborting."; exit 1; }
make programs && make install

/usr/local/sbin/ipsec --version 2>/dev/null | grep -qs "${SWAN_VER}"
if [ "$?" != "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