#!/bin/sh
#
# Script to upgrade Libreswan on CentOS and RHEL
#
# Copyright (C) 2016 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=3.17

### Do not edit below this line

if [ ! -f /etc/redhat-release ]; then
  echo "This script only supports CentOS or RHEL systems."
  exit 1
fi

if ! grep -qs -e "release 6" -e "release 7" /etc/redhat-release; then
  echo "This script only supports CentOS/RHEL 6 and 7."
  exit 1
fi

if [ "$(uname -m)" != "x86_64" ]; then
  echo "This script only supports 64-bit CentOS/RHEL."
  exit 1
fi

if [ -f /proc/user_beancounters ]; then
  echo "This script does NOT support OpenVZ VPS."
  exit 1
fi

if [ "$(id -u)" != 0 ]; then
  echo "Script must be run as root. Try 'sudo sh $0'"
  exit 1
fi

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

/usr/local/sbin/ipsec --version 2>/dev/null | grep -qs "Libreswan $SWAN_VER"
if [ "$?" = "0" ]; then
  echo "You already have Libreswan version $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

clear

echo "Welcome! This script will build and install Libreswan $SWAN_VER on your server."
echo "Additional packages required for Libreswan compilation will also be installed."
echo "This is intended for use on servers running an older version of Libreswan."
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 dir to /opt/src. Aborting."; exit 1; }

# Install Wget
yum -y install wget

# Add the EPEL repository
if grep -qs "release 6" /etc/redhat-release; then
  EPEL_RPM=epel-release-6-8.noarch.rpm
  EPEL_URL=http://download.fedoraproject.org/pub/epel/6/x86_64/$EPEL_RPM
elif grep -qs "release 7" /etc/redhat-release; then
  EPEL_RPM=epel-release-7-5.noarch.rpm
  EPEL_URL=http://download.fedoraproject.org/pub/epel/7/x86_64/e/$EPEL_RPM
fi
wget -t 3 -T 30 -nv -O "$EPEL_RPM" "$EPEL_URL"
[ ! -f "$EPEL_RPM" ] && { echo "Cannot retrieve EPEL repo RPM file. Aborting."; exit 1; }
rpm -ivh --force "$EPEL_RPM" && /bin/rm -f "$EPEL_RPM"

# Install necessary packages
yum -y install nss-devel nspr-devel pkgconfig pam-devel \
    libcap-ng-devel libselinux-devel \
    curl-devel flex bison gcc make \
    fipscheck-devel unbound-devel xmlto

# Installed Libevent2. Use backported version for CentOS 6.
if grep -qs "release 6" /etc/redhat-release; then
  LE2_URL=https://download.libreswan.org/binaries/rhel/6/x86_64
  RPM1=libevent2-2.0.22-1.el6.x86_64.rpm
  RPM2=libevent2-devel-2.0.22-1.el6.x86_64.rpm
  wget -t 3 -T 30 -nv -O "$RPM1" "$LE2_URL/$RPM1"
  wget -t 3 -T 30 -nv -O "$RPM2" "$LE2_URL/$RPM2"
  [ ! -f "$RPM1" ] || [ ! -f "$RPM2" ] && { echo "Cannot retrieve Libevent2 RPM file(s). Aborting."; exit 1; }
  rpm -ivh --force "$RPM1" "$RPM2" && /bin/rm -f "$RPM1" "$RPM2"
elif grep -qs "release 7" /etc/redhat-release; then
  yum -y install libevent-devel
fi

# Compile and install Libreswan
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 "$SWAN_FILE" ] && { echo "Cannot retrieve Libreswan source file. Aborting."; exit 1; }
/bin/rm -rf "/opt/src/libreswan-$SWAN_VER"
tar xvzf "$SWAN_FILE" && /bin/rm -f "$SWAN_FILE"
cd "libreswan-$SWAN_VER" || { echo "Failed to enter Libreswan source dir. Aborting."; exit 1; }
# Workaround for Libreswan compile issues
cat > Makefile.inc.local <<EOF
WERROR_CFLAGS =
EOF
make programs && make install

# Restore SELinux contexts
restorecon /etc/ipsec.d/*db 2>/dev/null
restorecon /usr/local/sbin -Rv 2>/dev/null
restorecon /usr/local/libexec/ipsec -Rv 2>/dev/null

# Restart IPsec service
service ipsec restart

# Check if Libreswan install was successful
/usr/local/sbin/ipsec --version 2>/dev/null | grep -qs "$SWAN_VER"
[ "$?" != "0" ] && { echo; echo "Sorry, Libreswan $SWAN_VER failed to build. Aborting."; exit 1; }

echo
echo "Libreswan $SWAN_VER was installed successfully! "
echo
exit 0