Add Alpine Linux

2024-11-24 22:06:07 +03:00 · 2021-09-11 15:00:29 -05:00 · 2021-09-11 15:00:29 -05:00 · 3c557c7f22
commit 3c557c7f22
parent e2a9c4a0c3
7 changed files with 1013 additions and 49 deletions
--- a/extras/ikev2setup.sh
+++ b/extras/ikev2setup.sh
@ -67,14 +67,19 @@ check_os() {
        ;;
      [Aa]lpine)
        os_type=alpine
-        [ "$in_container" != "1" ] && exiterr "This script only supports Alpine Linux in a Docker container."
        ;;
      *)
-        exiterr "This script only supports Ubuntu, Debian, CentOS/RHEL 7/8 and Amazon Linux 2."
+        echo "Error: This script only supports one of the following OS:" >&2
+        echo "       Ubuntu, Debian, CentOS/RHEL, Rocky Linux, AlmaLinux," >&2
+        echo "       Amazon Linux 2 and Alpine Linux" >&2
+        exit 1
        ;;
    esac
    if [ "$os_type" = "alpine" ]; then
-      os_ver=$(. /etc/os-release && printf '%s' "$VERSION_ID")
+      os_ver=$(. /etc/os-release && printf '%s' "$VERSION_ID" | cut -d '.' -f 1,2)
+      if [ "$os_ver" != "3.14" ]; then
+        exiterr "This script only supports Alpine Linux 3.14."
+      fi
    else
      os_ver=$(sed 's/\..*//' /etc/debian_version | tr -dc 'A-Za-z0-9')
    fi
--- a/extras/quickstart.sh
+++ b/extras/quickstart.sh
@ -1,6 +1,7 @@
 #!/bin/sh
 #
-# Quick start script to set up an IPsec VPN server with IPsec/L2TP, Cisco IPsec and IKEv2
+# Quick start script to set up an IPsec VPN server on Ubuntu, Debian,
+# CentOS/RHEL, Rocky Linux, AlmaLinux, Amazon Linux 2 and Alpine Linux
 # Works on any dedicated server or virtual private server (VPS)
 #
 # DO NOT RUN THIS SCRIPT ON YOUR PC OR MAC!
@ -61,10 +62,22 @@ check_os() {
      [Rr]aspbian)
        os_type=raspbian
        ;;
+      [Aa]lpine)
+        os_type=alpine
+        ;;
      *)
-        exiterr "This script only supports Ubuntu, Debian, CentOS/RHEL 7/8 and Amazon Linux 2."
+        echo "Error: This script only supports one of the following OS:" >&2
+        echo "       Ubuntu, Debian, CentOS/RHEL, Rocky Linux, AlmaLinux," >&2
+        echo "       Amazon Linux 2 and Alpine Linux" >&2
+        exit 1
        ;;
    esac
+    if [ "$os_type" = "alpine" ]; then
+      os_ver=$(. /etc/os-release && printf '%s' "$VERSION_ID" | cut -d '.' -f 1,2)
+      if [ "$os_ver" != "3.14" ]; then
+        exiterr "This script only supports Alpine Linux 3.14."
+      fi
+    else
      os_ver=$(sed 's/\..*//' /etc/debian_version | tr -dc 'A-Za-z0-9')
      if [ "$os_ver" = "8" ] || [ "$os_ver" = "jessiesid" ]; then
        exiterr "Debian 8 or Ubuntu < 16.04 is not supported."
@ -73,11 +86,14 @@ check_os() {
        exiterr "/dev/ppp is missing. Debian 11 or 10 users, see: https://git.io/vpndebian10"
      fi
    fi
+  fi
 }

 check_iface() {
  def_iface=$(route 2>/dev/null | grep -m 1 '^default' | grep -o '[^ ]*$')
+  if [ "$os_type" != "alpine" ]; then
    [ -z "$def_iface" ] && def_iface=$(ip -4 route list 0/0 2>/dev/null | grep -m 1 -Po '(?<=dev )(\S+)')
+  fi
  def_state=$(cat "/sys/class/net/$def_iface/operstate" 2>/dev/null)
  check_wl=0
  if [ -n "$def_state" ] && [ "$def_state" != "down" ]; then
@ -120,7 +136,7 @@ wait_for_apt() {
  done
 }

-install_wget() {
+install_pkgs() {
  if ! command -v wget >/dev/null 2>&1; then
    if [ "$os_type" = "ubuntu" ] || [ "$os_type" = "debian" ] || [ "$os_type" = "raspbian" ]; then
      wait_for_apt
@ -133,13 +149,19 @@ install_wget() {
        set -x
        apt-get -yqq install wget >/dev/null
      ) || exiterr "'apt-get install wget' failed."
-    else
+    elif [ "$os_type" != "alpine" ]; then
      (
        set -x
        yum -y -q install wget >/dev/null
      ) || exiterr "'yum install wget' failed."
    fi
  fi
+  if [ "$os_type" = "alpine" ]; then
+    (
+      set -x
+      apk add -U -q bash net-tools wget sed grep
+    ) || exiterr "'apk add' failed."
+  fi
 }

 get_setup_url() {
@ -149,6 +171,8 @@ get_setup_url() {
    sh_file="vpnsetup_centos.sh"
  elif [ "$os_type" = "amzn" ]; then
    sh_file="vpnsetup_amzn.sh"
+  elif [ "$os_type" = "alpine" ]; then
+    sh_file="vpnsetup_alpine.sh"
  fi
  setup_url="$base_url/$sh_file"
 }
@ -183,7 +207,7 @@ quickstart() {
  check_os
  check_iface
  check_iptables
-  install_wget
+  install_pkgs
  get_setup_url
  run_setup
 }
--- a/extras/vpnuninstall.sh
+++ b/extras/vpnuninstall.sh
@ -1,7 +1,7 @@
 #!/bin/bash
 #
 # Script to uninstall IPsec VPN on Ubuntu, Debian, CentOS/RHEL,
-# Rocky Linux, AlmaLinux and Amazon Linux 2
+# Rocky Linux, AlmaLinux, Amazon Linux 2 and Alpine Linux
 #
 # DO NOT RUN THIS SCRIPT ON YOUR PC OR MAC!
 #
@ -53,8 +53,14 @@ check_os() {
      [Rr]aspbian)
        os_type=raspbian
        ;;
+      [Aa]lpine)
+        os_type=alpine
+        ;;
      *)
-        exiterr "This script only supports Ubuntu, Debian, CentOS/RHEL 7/8 and Amazon Linux 2."
+        echo "Error: This script only supports one of the following OS:" >&2
+        echo "       Ubuntu, Debian, CentOS/RHEL, Rocky Linux, AlmaLinux," >&2
+        echo "       Amazon Linux 2 and Alpine Linux" >&2
+        exit 1
        ;;
    esac
  fi
@ -70,7 +76,9 @@ check_libreswan() {

 check_iface() {
  def_iface=$(route 2>/dev/null | grep -m 1 '^default' | grep -o '[^ ]*$')
+  if [ "$os_type" != "alpine" ]; then
    [ -z "$def_iface" ] && def_iface=$(ip -4 route list 0/0 2>/dev/null | grep -m 1 -Po '(?<=dev )(\S+)')
+  fi
  def_state=$(cat "/sys/class/net/$def_iface/operstate" 2>/dev/null)
  if [ -n "$def_state" ] && [ "$def_state" != "down" ]; then
    check_wl=0
@ -146,6 +154,8 @@ remove_xl2tpd() {
  if [ "$os_type" = "ubuntu" ] || [ "$os_type" = "debian" ] || [ "$os_type" = "raspbian" ]; then
    export DEBIAN_FRONTEND=noninteractive
    apt-get -yqq purge xl2tpd >/dev/null
+  elif [ "$os_type" = "alpine" ]; then
+    apk del -q xl2tpd
  else
    yum -y -q remove xl2tpd >/dev/null
  fi
@ -155,7 +165,11 @@ update_sysctl() {
  if grep -qs "hwdsl2 VPN script" /etc/sysctl.conf; then
    bigecho "Updating sysctl settings..."
    conf_bk "/etc/sysctl.conf"
+    if [ "$os_type" = "alpine" ]; then
+      sed -i '/# Added by hwdsl2 VPN script/,+17d' /etc/sysctl.conf
+    else
      sed --follow-symlinks -i '/# Added by hwdsl2 VPN script/,+17d' /etc/sysctl.conf
+    fi
    echo 0 > /proc/sys/net/ipv4/ip_forward
  fi
 }
@ -164,13 +178,18 @@ update_rclocal() {
  if grep -qs "hwdsl2 VPN script" /etc/rc.local; then
    bigecho "Updating rc.local..."
    conf_bk "/etc/rc.local"
+    if [ "$os_type" = "alpine" ]; then
+      sed -i '/# Added by hwdsl2 VPN script/,+4d' /etc/rc.local
+    else
      sed --follow-symlinks -i '/# Added by hwdsl2 VPN script/,+4d' /etc/rc.local
    fi
+  fi
 }

 update_iptables_rules() {
  use_nft=0
-  if [ "$os_type" = "ubuntu" ] || [ "$os_type" = "debian" ] || [ "$os_type" = "raspbian" ]; then
+  if [ "$os_type" = "ubuntu" ] || [ "$os_type" = "debian" ] || [ "$os_type" = "raspbian" ] \
+    || [ "$os_type" = "alpine" ]; then
    IPT_FILE=/etc/iptables.rules
    IPT_FILE2=/etc/iptables/rules.v4
  else
--- a/extras/vpnupgrade.sh
+++ b/extras/vpnupgrade.sh
@ -1,7 +1,7 @@
 #!/bin/sh
 #
 # Script to update Libreswan on Ubuntu, Debian, CentOS/RHEL, Rocky Linux,
-# AlmaLinux and Amazon Linux 2
+# AlmaLinux, Amazon Linux 2 and Alpine Linux
 #
 # The latest version of this script is available at:
 # https://github.com/hwdsl2/setup-ipsec-vpn
@ -64,18 +64,32 @@ check_os() {
      [Rr]aspbian)
        os_type=raspbian
        ;;
+      [Aa]lpine)
+        os_type=alpine
+        ;;
      *)
-        exiterr "This script only supports Ubuntu, Debian, CentOS/RHEL 7/8 and Amazon Linux 2."
+        echo "Error: This script only supports one of the following OS:" >&2
+        echo "       Ubuntu, Debian, CentOS/RHEL, Rocky Linux, AlmaLinux," >&2
+        echo "       Amazon Linux 2 and Alpine Linux" >&2
+        exit 1
        ;;
    esac
+    if [ "$os_type" = "alpine" ]; then
+      os_ver=$(. /etc/os-release && printf '%s' "$VERSION_ID" | cut -d '.' -f 1,2)
+      if [ "$os_ver" != "3.14" ]; then
+        exiterr "This script only supports Alpine Linux 3.14."
+      fi
+    else
      os_ver=$(sed 's/\..*//' /etc/debian_version | tr -dc 'A-Za-z0-9')
      if [ "$os_ver" = "8" ] || [ "$os_ver" = "jessiesid" ]; then
        exiterr "Debian 8 or Ubuntu < 16.04 is not supported."
      fi
    fi
+  fi
 }

 check_libreswan() {
+  if [ "$os_type" != "alpine" ]; then
    case $SWAN_VER in
      3.32|4.[1-5])
        true
@ -89,6 +103,20 @@ EOF
        exit 1
        ;;
    esac
+  else
+    case $SWAN_VER in
+      4.5)
+        true
+        ;;
+      *)
+cat 1>&2 <<EOF
+Error: Libreswan version '$SWAN_VER' is not supported.
+       This script can install Libreswan 4.5.
+EOF
+        exit 1
+        ;;
+    esac
+  fi

  if [ "$SWAN_VER" = "3.32" ] && [ "$os_ver" = "11" ]; then
    exiterr "Libreswan 3.32 is not supported on Debian 11."
@ -104,7 +132,7 @@ EOF
  fi
 }

-install_wget() {
+install_pkgs() {
  if ! command -v wget >/dev/null 2>&1; then
    if [ "$os_type" = "ubuntu" ] || [ "$os_type" = "debian" ] || [ "$os_type" = "raspbian" ]; then
      export DEBIAN_FRONTEND=noninteractive
@ -116,13 +144,19 @@ install_wget() {
        set -x
        apt-get -yqq install wget >/dev/null
      ) || exiterr "'apt-get install wget' failed."
-    else
+    elif [ "$os_type" != "alpine" ]; then
      (
        set -x
        yum -y -q install wget >/dev/null
      ) || exiterr "'yum install wget' failed."
    fi
  fi
+  if [ "$os_type" = "alpine" ]; then
+    (
+      set -x
+      apk add -U -q bash wget sed grep
+    ) || exiterr "'apk add' failed."
+  fi
 }

 get_setup_url() {
@ -132,6 +166,8 @@ get_setup_url() {
    sh_file="vpnupgrade_centos.sh"
  elif [ "$os_type" = "amzn" ]; then
    sh_file="vpnupgrade_amzn.sh"
+  elif [ "$os_type" = "alpine" ]; then
+    sh_file="vpnupgrade_alpine.sh"
  fi
  setup_url="$base_url/$sh_file"
 }
@ -158,7 +194,7 @@ vpnupgrade() {
  check_vz
  check_os
  check_libreswan
-  install_wget
+  install_pkgs
  get_setup_url
  run_setup
 }
--- a/extras/vpnupgrade_alpine.sh
+++ b/extras/vpnupgrade_alpine.sh
@ -0,0 +1,311 @@
+#!/bin/bash
+#
+# Script to update Libreswan on Alpine Linux
+#
+# The latest version of this script is available at:
+# https://github.com/hwdsl2/setup-ipsec-vpn
+#
+# Copyright (C) 2021 Lin Song <linsongui@gmail.com>
+#
+# 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!
+
+# Specify which Libreswan version to install. See: https://libreswan.org
+SWAN_VER=4.5
+
+### DO NOT edit below this line ###
+
+export PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
+[ -n "$VPN_UPDATE_SWAN_VER" ] && SWAN_VER="$VPN_UPDATE_SWAN_VER"
+
+exiterr()  { echo "Error: $1" >&2; exit 1; }
+exiterr2() { exiterr "'apk add' failed."; }
+bigecho() { echo "## $1"; }
+
+check_root() {
+  if [ "$(id -u)" != 0 ]; then
+    exiterr "Script must be run as root. Try 'sudo bash $0'"
+  fi
+}
+
+check_vz() {
+  if [ -f /proc/user_beancounters ]; then
+    exiterr "OpenVZ VPS is not supported."
+  fi
+}
+
+check_os() {
+  os_type=$(lsb_release -si 2>/dev/null)
+  os_arch=$(uname -m | tr -dc 'A-Za-z0-9_-')
+  [ -z "$os_type" ] && [ -f /etc/os-release ] && os_type=$(. /etc/os-release && printf '%s' "$ID")
+  case $os_type in
+    [Aa]lpine)
+      os_type=alpine
+      ;;
+    *)
+      exiterr "This script only supports Alpine Linux."
+      ;;
+  esac
+  os_ver=$(. /etc/os-release && printf '%s' "$VERSION_ID" | cut -d '.' -f 1,2)
+  if [ "$os_ver" != "3.14" ]; then
+    exiterr "This script only supports Alpine Linux 3.14."
+  fi
+}
+
+check_libreswan() {
+  case $SWAN_VER in
+    4.5)
+      true
+      ;;
+    *)
+cat 1>&2 <<EOF
+Error: Libreswan version '$SWAN_VER' is not supported.
+       This script can install Libreswan 4.5.
+EOF
+      exit 1
+      ;;
+  esac
+
+  ipsec_ver=$(/usr/local/sbin/ipsec --version 2>/dev/null)
+  swan_ver_old=$(printf '%s' "$ipsec_ver" | sed -e 's/.*Libreswan U\?//' -e 's/\( (\|\/K\).*//')
+  if ! printf '%s' "$ipsec_ver" | grep -q "Libreswan"; then
+cat 1>&2 <<'EOF'
+Error: This script requires Libreswan already installed.
+       See: https://github.com/hwdsl2/setup-ipsec-vpn
+EOF
+    exit 1
+  fi
+
+  if [ "$swan_ver_old" = "$SWAN_VER" ]; then
+cat <<EOF
+You already have Libreswan version $SWAN_VER installed!
+If you continue, the same version will be re-installed.
+
+EOF
+    printf "Do you want to continue anyway? [y/N] "
+    read -r response
+    case $response in
+      [yY][eE][sS]|[yY])
+        echo
+        ;;
+      *)
+        echo "Abort. No changes were made."
+        exit 1
+        ;;
+    esac
+  fi
+}
+
+show_setup_info() {
+cat <<EOF
+
+Welcome! Use this script to update Libreswan on your IPsec VPN server.
+
+Current version:    Libreswan $swan_ver_old
+Version to install: Libreswan $SWAN_VER
+
+Note: This script will make the following changes to your VPN configuration:
+      - Fix obsolete ipsec.conf and/or ikev2.conf options
+      - Optimize VPN ciphers
+      Your other VPN config files will not be modified.
+
+EOF
+
+  if [ "$SWAN_VER" != "4.5" ]; then
+cat <<'EOF'
+WARNING: Older versions of Libreswan could contain known security vulnerabilities.
+         See https://libreswan.org/security/ for more information.
+         Are you sure you want to install an older version?
+
+EOF
+  fi
+
+  printf "Do you want to continue? [y/N] "
+  read -r response
+  case $response in
+    [yY][eE][sS]|[yY])
+      echo
+      ;;
+    *)
+      echo "Abort. No changes were made."
+      exit 1
+      ;;
+  esac
+}
+
+start_setup() {
+  # shellcheck disable=SC2154
+  trap 'dlo=$dl;dl=$LINENO' DEBUG 2>/dev/null
+  trap 'finish $? $((dlo+1))' EXIT
+  mkdir -p /opt/src
+  cd /opt/src || exit 1
+}
+
+install_pkgs() {
+  bigecho "Installing required packages..."
+  (
+    set -x
+    apk add -U -q bash bind-tools coreutils openssl wget iproute2 sed grep \
+    libcap-ng libcurl libevent linux-pam musl nspr nss nss-tools \
+    bison flex gcc make libc-dev bsd-compat-headers linux-pam-dev nss-dev \
+    libcap-ng-dev libevent-dev curl-dev nspr-dev uuidgen openrc
+  ) || exiterr2
+}
+
+get_libreswan() {
+  bigecho "Downloading Libreswan..."
+  swan_file="libreswan-$SWAN_VER.tar.gz"
+  swan_url1="https://github.com/libreswan/libreswan/archive/v$SWAN_VER.tar.gz"
+  swan_url2="https://download.libreswan.org/$swan_file"
+  (
+    set -x
+    wget -t 3 -T 30 -q -O "$swan_file" "$swan_url1" || wget -t 3 -T 30 -q -O "$swan_file" "$swan_url2"
+  ) || exit 1
+  /bin/rm -rf "/opt/src/libreswan-$SWAN_VER"
+  tar xzf "$swan_file" && /bin/rm -f "$swan_file"
+}
+
+install_libreswan() {
+  bigecho "Compiling and installing Libreswan, please wait..."
+  cd "libreswan-$SWAN_VER" || exit 1
+  sed -i '28s/stdlib\.h/sys\/types.h/' include/fd.h
+cat > Makefile.inc.local <<'EOF'
+WERROR_CFLAGS=-w -s
+USE_DNSSEC=false
+USE_DH2=true
+FINALNSSDIR=/etc/ipsec.d
+USE_GLIBC_KERN_FLIP_HEADERS=true
+EOF
+  NPROCS=$(grep -c ^processor /proc/cpuinfo)
+  [ -z "$NPROCS" ] && NPROCS=1
+  (
+    set -x
+    make "-j$((NPROCS+1))" -s base >/dev/null && make -s install-base >/dev/null
+  )
+
+  cd /opt/src || exit 1
+  /bin/rm -rf "/opt/src/libreswan-$SWAN_VER"
+  if ! /usr/local/sbin/ipsec --version 2>/dev/null | grep -qF "$SWAN_VER"; then
+    exiterr "Libreswan $SWAN_VER failed to build."
+  fi
+}
+
+update_config() {
+  bigecho "Updating VPN configuration..."
+  IKE_NEW="  ike=aes256-sha2,aes128-sha2,aes256-sha1,aes128-sha1,aes256-sha2;modp1024,aes128-sha1;modp1024"
+  PHASE2_NEW="  phase2alg=aes_gcm-null,aes128-sha1,aes256-sha1,aes256-sha2_512,aes128-sha2,aes256-sha2"
+
+  if uname -m | grep -qi '^arm'; then
+    if ! modprobe -q sha512; then
+      PHASE2_NEW="  phase2alg=aes_gcm-null,aes128-sha1,aes256-sha1,aes128-sha2,aes256-sha2"
+    fi
+  fi
+
+  dns_state=0
+  DNS_SRV1=$(grep "modecfgdns1=" /etc/ipsec.conf | head -n 1 | cut -d '=' -f 2)
+  DNS_SRV2=$(grep "modecfgdns2=" /etc/ipsec.conf | head -n 1 | cut -d '=' -f 2)
+  [ -n "$DNS_SRV1" ] && dns_state=2
+  [ -n "$DNS_SRV1" ] && [ -n "$DNS_SRV2" ] && dns_state=1
+  [ "$(grep -c "modecfgdns1=" /etc/ipsec.conf)" -gt "1" ] && dns_state=3
+
+  sed -i".old-$(date +%F-%T)" \
+      -e "s/^[[:space:]]\+auth=/  phase2=/" \
+      -e "s/^[[:space:]]\+forceencaps=/  encapsulation=/" \
+      -e "s/^[[:space:]]\+ike-frag=/  fragmentation=/" \
+      -e "s/^[[:space:]]\+sha2_truncbug=/  sha2-truncbug=/" \
+      -e "s/^[[:space:]]\+sha2-truncbug=yes/  sha2-truncbug=no/" \
+      -e "s/^[[:space:]]\+ike=.\+/$IKE_NEW/" \
+      -e "s/^[[:space:]]\+phase2alg=.\+/$PHASE2_NEW/" /etc/ipsec.conf
+
+  if [ "$dns_state" = "1" ]; then
+    sed -i -e "s/^[[:space:]]\+modecfgdns1=.\+/  modecfgdns=\"$DNS_SRV1 $DNS_SRV2\"/" \
+        -e "/modecfgdns2=/d" /etc/ipsec.conf
+  elif [ "$dns_state" = "2" ]; then
+    sed -i "s/^[[:space:]]\+modecfgdns1=.\+/  modecfgdns=$DNS_SRV1/" /etc/ipsec.conf
+  fi
+
+  sed -i "/ikev2=never/d" /etc/ipsec.conf
+  sed -i "/conn shared/a \  ikev2=never" /etc/ipsec.conf
+
+  if grep -qs ike-frag /etc/ipsec.d/ikev2.conf; then
+    sed -i 's/^[[:space:]]\+ike-frag=/  fragmentation=/' /etc/ipsec.d/ikev2.conf
+  fi
+}
+
+restart_ipsec() {
+  bigecho "Restarting IPsec service..."
+  mkdir -p /run/pluto
+  service ipsec restart >/dev/null 2>&1
+}
+
+show_setup_complete() {
+cat <<EOF
+
+================================================
+
+Libreswan $SWAN_VER has been successfully installed!
+
+================================================
+
+EOF
+
+  if [ "$dns_state" = "3" ]; then
+cat <<'EOF'
+IMPORTANT: You must edit /etc/ipsec.conf and replace
+           all occurrences of these two lines:
+             modecfgdns1=DNS_SERVER_1
+             modecfgdns2=DNS_SERVER_2
+
+           with a single line like this:
+             modecfgdns="DNS_SERVER_1 DNS_SERVER_2"
+
+           Then run "sudo service ipsec restart".
+
+EOF
+  fi
+}
+
+check_swan_ver() {
+  swan_ver_cur=4.5
+  swan_ver_url="https://dl.ls20.com/v1/$os_type/$os_ver/swanverupg?arch=$os_arch&ver1=$swan_ver_old&ver2=$SWAN_VER"
+  [ "$1" != "0" ] && swan_ver_url="$swan_ver_url&e=$2"
+  swan_ver_latest=$(wget -t 3 -T 15 -qO- "$swan_ver_url")
+  if printf '%s' "$swan_ver_latest" | grep -Eq '^([3-9]|[1-9][0-9]{1,2})(\.([0-9]|[1-9][0-9]{1,2})){1,2}$' \
+    && [ "$1" = "0" ] && [ "$swan_ver_cur" != "$swan_ver_latest" ] \
+    && printf '%s\n%s' "$swan_ver_cur" "$swan_ver_latest" | sort -C -V; then
+cat <<EOF
+Note: A newer version of Libreswan ($swan_ver_latest) is available.
+      To update, run:
+      wget https://git.io/vpnupgrade -O vpnup.sh && sudo sh vpnup.sh
+
+EOF
+  fi
+}
+
+finish() {
+  check_swan_ver "$1" "$2"
+  exit "$1"
+}
+
+vpnupgrade() {
+  check_root
+  check_vz
+  check_os
+  check_libreswan
+  show_setup_info
+  start_setup
+  install_pkgs
+  get_libreswan
+  install_libreswan
+  update_config
+  restart_ipsec
+  show_setup_complete
+}
+
+## Defer setup until we have the complete script
+vpnupgrade "$@"
+
+exit 0
--- a/vpnsetup.sh
+++ b/vpnsetup.sh
@ -1,7 +1,7 @@
 #!/bin/sh
 #
 # Script for automatic setup of an IPsec VPN server on Ubuntu, Debian,
-# CentOS/RHEL, Rocky Linux, AlmaLinux and Amazon Linux 2
+# CentOS/RHEL, Rocky Linux, AlmaLinux, Amazon Linux 2 and Alpine Linux
 # Works on any dedicated server or virtual private server (VPS)
 #
 # DO NOT RUN THIS SCRIPT ON YOUR PC OR MAC!
@ -84,10 +84,22 @@ check_os() {
      [Rr]aspbian)
        os_type=raspbian
        ;;
+      [Aa]lpine)
+        os_type=alpine
+        ;;
      *)
-        exiterr "This script only supports Ubuntu, Debian, CentOS/RHEL 7/8 and Amazon Linux 2."
+        echo "Error: This script only supports one of the following OS:" >&2
+        echo "       Ubuntu, Debian, CentOS/RHEL, Rocky Linux, AlmaLinux," >&2
+        echo "       Amazon Linux 2 and Alpine Linux" >&2
+        exit 1
        ;;
    esac
+    if [ "$os_type" = "alpine" ]; then
+      os_ver=$(. /etc/os-release && printf '%s' "$VERSION_ID" | cut -d '.' -f 1,2)
+      if [ "$os_ver" != "3.14" ]; then
+        exiterr "This script only supports Alpine Linux 3.14."
+      fi
+    else
      os_ver=$(sed 's/\..*//' /etc/debian_version | tr -dc 'A-Za-z0-9')
      if [ "$os_ver" = "8" ] || [ "$os_ver" = "jessiesid" ]; then
        exiterr "Debian 8 or Ubuntu < 16.04 is not supported."
@ -96,11 +108,14 @@ check_os() {
        exiterr "/dev/ppp is missing. Debian 11 or 10 users, see: https://git.io/vpndebian10"
      fi
    fi
+  fi
 }

 check_iface() {
  def_iface=$(route 2>/dev/null | grep -m 1 '^default' | grep -o '[^ ]*$')
+  if [ "$os_type" != "alpine" ]; then
    [ -z "$def_iface" ] && def_iface=$(ip -4 route list 0/0 2>/dev/null | grep -m 1 -Po '(?<=dev )(\S+)')
+  fi
  def_state=$(cat "/sys/class/net/$def_iface/operstate" 2>/dev/null)
  check_wl=0
  if [ -n "$def_state" ] && [ "$def_state" != "down" ]; then
@ -174,7 +189,7 @@ wait_for_apt() {
  done
 }

-install_wget() {
+install_pkgs() {
  if ! command -v wget >/dev/null 2>&1; then
    if [ "$os_type" = "ubuntu" ] || [ "$os_type" = "debian" ] || [ "$os_type" = "raspbian" ]; then
      wait_for_apt
@ -187,13 +202,19 @@ install_wget() {
        set -x
        apt-get -yqq install wget >/dev/null
      ) || exiterr "'apt-get install wget' failed."
-    else
+    elif [ "$os_type" != "alpine" ]; then
      (
        set -x
        yum -y -q install wget >/dev/null
      ) || exiterr "'yum install wget' failed."
    fi
  fi
+  if [ "$os_type" = "alpine" ]; then
+    (
+      set -x
+      apk add -U -q bash net-tools wget sed grep
+    ) || exiterr "'apk add' failed."
+  fi
 }

 get_setup_url() {
@ -203,6 +224,8 @@ get_setup_url() {
    sh_file="vpnsetup_centos.sh"
  elif [ "$os_type" = "amzn" ]; then
    sh_file="vpnsetup_amzn.sh"
+  elif [ "$os_type" = "alpine" ]; then
+    sh_file="vpnsetup_alpine.sh"
  fi
  setup_url="$base_url/$sh_file"
 }
@ -237,7 +260,7 @@ vpnsetup() {
  check_creds
  check_dns
  check_iptables
-  install_wget
+  install_pkgs
  get_setup_url
  run_setup
 }
--- a/vpnsetup_alpine.sh
+++ b/vpnsetup_alpine.sh
@ -0,0 +1,546 @@
+#!/bin/bash
+#
+# Script for automatic setup of an IPsec VPN server on Alpine Linux
+#
+# DO NOT RUN THIS SCRIPT ON YOUR PC OR MAC!
+#
+# The latest version of this script is available at:
+# https://github.com/hwdsl2/setup-ipsec-vpn
+#
+# Copyright (C) 2021 Lin Song <linsongui@gmail.com>
+#
+# 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!
+
+# =====================================================
+
+# Define your own values for these variables
+# - IPsec pre-shared key, VPN username and password
+# - All values MUST be placed inside 'single quotes'
+# - DO NOT use these special characters within values: \ " '
+
+YOUR_IPSEC_PSK=''
+YOUR_USERNAME=''
+YOUR_PASSWORD=''
+
+# Important notes:   https://git.io/vpnnotes
+# Setup VPN clients: https://git.io/vpnclients
+# IKEv2 guide:       https://git.io/ikev2
+
+# =====================================================
+
+export PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
+SYS_DT=$(date +%F-%T | tr ':' '_')
+
+exiterr()  { echo "Error: $1" >&2; exit 1; }
+exiterr2() { exiterr "'apk add' failed."; }
+conf_bk() { /bin/cp -f "$1" "$1.old-$SYS_DT" 2>/dev/null; }
+bigecho() { echo "## $1"; }
+
+check_ip() {
+  IP_REGEX='^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$'
+  printf '%s' "$1" | tr -d '\n' | grep -Eq "$IP_REGEX"
+}
+
+check_root() {
+  if [ "$(id -u)" != 0 ]; then
+    exiterr "Script must be run as root. Try 'sudo bash $0'"
+  fi
+}
+
+check_vz() {
+  if [ -f /proc/user_beancounters ]; then
+    exiterr "OpenVZ VPS is not supported."
+  fi
+}
+
+check_os() {
+  os_type=$(lsb_release -si 2>/dev/null)
+  os_arch=$(uname -m | tr -dc 'A-Za-z0-9_-')
+  [ -z "$os_type" ] && [ -f /etc/os-release ] && os_type=$(. /etc/os-release && printf '%s' "$ID")
+  case $os_type in
+    [Aa]lpine)
+      os_type=alpine
+      ;;
+    *)
+      exiterr "This script only supports Alpine Linux."
+      ;;
+  esac
+  os_ver=$(. /etc/os-release && printf '%s' "$VERSION_ID" | cut -d '.' -f 1,2)
+  if [ "$os_ver" != "3.14" ]; then
+    exiterr "This script only supports Alpine Linux 3.14."
+  fi
+}
+
+check_iface() {
+  def_iface=$(route 2>/dev/null | grep -m 1 '^default' | grep -o '[^ ]*$')
+  def_state=$(cat "/sys/class/net/$def_iface/operstate" 2>/dev/null)
+  if [ -n "$def_state" ] && [ "$def_state" != "down" ]; then
+    if ! uname -m | grep -qi -e '^arm' -e '^aarch64'; then
+      case $def_iface in
+        wl*)
+          exiterr "Wireless interface '$def_iface' detected. DO NOT run this script on your PC or Mac!"
+          ;;
+      esac
+    fi
+    NET_IFACE="$def_iface"
+  else
+    eth0_state=$(cat "/sys/class/net/eth0/operstate" 2>/dev/null)
+    if [ -z "$eth0_state" ] || [ "$eth0_state" = "down" ]; then
+      exiterr "Could not detect the default network interface."
+    fi
+    NET_IFACE=eth0
+  fi
+}
+
+check_creds() {
+  [ -n "$YOUR_IPSEC_PSK" ] && VPN_IPSEC_PSK="$YOUR_IPSEC_PSK"
+  [ -n "$YOUR_USERNAME" ] && VPN_USER="$YOUR_USERNAME"
+  [ -n "$YOUR_PASSWORD" ] && VPN_PASSWORD="$YOUR_PASSWORD"
+
+  if [ -z "$VPN_IPSEC_PSK" ] && [ -z "$VPN_USER" ] && [ -z "$VPN_PASSWORD" ]; then
+    bigecho "VPN credentials not set by user. Generating random PSK and password..."
+    VPN_IPSEC_PSK=$(LC_CTYPE=C tr -dc 'A-HJ-NPR-Za-km-z2-9' </dev/urandom 2>/dev/null | head -c 20)
+    VPN_USER=vpnuser
+    VPN_PASSWORD=$(LC_CTYPE=C tr -dc 'A-HJ-NPR-Za-km-z2-9' </dev/urandom 2>/dev/null | head -c 16)
+  fi
+
+  if [ -z "$VPN_IPSEC_PSK" ] || [ -z "$VPN_USER" ] || [ -z "$VPN_PASSWORD" ]; then
+    exiterr "All VPN credentials must be specified. Edit the script and re-enter them."
+  fi
+
+  if printf '%s' "$VPN_IPSEC_PSK $VPN_USER $VPN_PASSWORD" | LC_ALL=C grep -q '[^ -~]\+'; then
+    exiterr "VPN credentials must not contain non-ASCII characters."
+  fi
+
+  case "$VPN_IPSEC_PSK $VPN_USER $VPN_PASSWORD" in
+    *[\\\"\']*)
+      exiterr "VPN credentials must not contain these special characters: \\ \" '"
+      ;;
+  esac
+}
+
+check_dns() {
+  if { [ -n "$VPN_DNS_SRV1" ] && ! check_ip "$VPN_DNS_SRV1"; } \
+    || { [ -n "$VPN_DNS_SRV2" ] && ! check_ip "$VPN_DNS_SRV2"; } then
+    exiterr "The DNS server specified is invalid."
+  fi
+}
+
+start_setup() {
+  bigecho "VPN setup in progress... Please be patient."
+  # shellcheck disable=SC2154
+  trap 'dlo=$dl;dl=$LINENO' DEBUG 2>/dev/null
+  trap 'finish $? $((dlo+1))' EXIT
+  mkdir -p /opt/src
+  cd /opt/src || exit 1
+}
+
+install_setup_pkgs() {
+  bigecho "Installing packages required for setup..."
+  (
+    set -x
+    apk add -U -q bash bind-tools coreutils openssl wget iproute2 sed grep
+  ) || exiterr2
+}
+
+detect_ip() {
+  bigecho "Trying to auto discover IP of this server..."
+  public_ip=${VPN_PUBLIC_IP:-''}
+  check_ip "$public_ip" || public_ip=$(dig @resolver1.opendns.com -t A -4 myip.opendns.com +short)
+  check_ip "$public_ip" || public_ip=$(wget -t 3 -T 15 -qO- http://ipv4.icanhazip.com)
+  check_ip "$public_ip" || exiterr "Cannot detect this server's public IP. Define it as variable 'VPN_PUBLIC_IP' and re-run this script."
+}
+
+install_vpn_pkgs() {
+  bigecho "Installing packages required for the VPN..."
+  (
+    set -x
+    apk add -U -q libcap-ng libcurl libevent linux-pam musl nspr nss nss-tools \
+      bison flex gcc make libc-dev bsd-compat-headers linux-pam-dev nss-dev \
+      libcap-ng-dev libevent-dev curl-dev nspr-dev uuidgen openrc xl2tpd
+  ) || exiterr2
+}
+
+install_fail2ban() {
+  bigecho "Installing Fail2Ban to protect SSH..."
+  (
+    set -x
+    apk add -U -q fail2ban
+  ) || exiterr2
+}
+
+get_ikev2_script() {
+  bigecho "Downloading IKEv2 script..."
+  ikev2_url="https://github.com/hwdsl2/setup-ipsec-vpn/raw/master/extras/ikev2setup.sh"
+  (
+    set -x
+    wget -t 3 -T 30 -q -O ikev2.sh "$ikev2_url"
+  ) || /bin/rm -f ikev2.sh
+  [ -s ikev2.sh ] && chmod +x ikev2.sh && ln -s /opt/src/ikev2.sh /usr/bin 2>/dev/null
+}
+
+check_libreswan() {
+  SWAN_VER=4.5
+  ipsec_ver=$(/usr/local/sbin/ipsec --version 2>/dev/null)
+  swan_ver_old=$(printf '%s' "$ipsec_ver" | sed -e 's/.*Libreswan U\?//' -e 's/\( (\|\/K\).*//')
+  [ "$swan_ver_old" = "$SWAN_VER" ]
+}
+
+get_libreswan() {
+  if ! check_libreswan; then
+    bigecho "Downloading Libreswan..."
+    swan_file="libreswan-$SWAN_VER.tar.gz"
+    swan_url1="https://github.com/libreswan/libreswan/archive/v$SWAN_VER.tar.gz"
+    swan_url2="https://download.libreswan.org/$swan_file"
+    (
+      set -x
+      wget -t 3 -T 30 -q -O "$swan_file" "$swan_url1" || wget -t 3 -T 30 -q -O "$swan_file" "$swan_url2"
+    ) || exit 1
+    /bin/rm -rf "/opt/src/libreswan-$SWAN_VER"
+    tar xzf "$swan_file" && /bin/rm -f "$swan_file"
+  else
+    bigecho "Libreswan $SWAN_VER is already installed, skipping..."
+  fi
+}
+
+install_libreswan() {
+  if ! check_libreswan; then
+    bigecho "Compiling and installing Libreswan, please wait..."
+    cd "libreswan-$SWAN_VER" || exit 1
+    sed -i '28s/stdlib\.h/sys\/types.h/' include/fd.h
+cat > Makefile.inc.local <<'EOF'
+WERROR_CFLAGS=-w -s
+USE_DNSSEC=false
+USE_DH2=true
+FINALNSSDIR=/etc/ipsec.d
+USE_GLIBC_KERN_FLIP_HEADERS=true
+EOF
+    NPROCS=$(grep -c ^processor /proc/cpuinfo)
+    [ -z "$NPROCS" ] && NPROCS=1
+    (
+      set -x
+      make "-j$((NPROCS+1))" -s base >/dev/null && make -s install-base >/dev/null
+    )
+
+    cd /opt/src || exit 1
+    /bin/rm -rf "/opt/src/libreswan-$SWAN_VER"
+    if ! /usr/local/sbin/ipsec --version 2>/dev/null | grep -qF "$SWAN_VER"; then
+      exiterr "Libreswan $SWAN_VER failed to build."
+    fi
+  fi
+}
+
+create_vpn_config() {
+  bigecho "Creating VPN configuration..."
+
+  L2TP_NET=${VPN_L2TP_NET:-'192.168.42.0/24'}
+  L2TP_LOCAL=${VPN_L2TP_LOCAL:-'192.168.42.1'}
+  L2TP_POOL=${VPN_L2TP_POOL:-'192.168.42.10-192.168.42.250'}
+  XAUTH_NET=${VPN_XAUTH_NET:-'192.168.43.0/24'}
+  XAUTH_POOL=${VPN_XAUTH_POOL:-'192.168.43.10-192.168.43.250'}
+  DNS_SRV1=${VPN_DNS_SRV1:-'8.8.8.8'}
+  DNS_SRV2=${VPN_DNS_SRV2:-'8.8.4.4'}
+  DNS_SRVS="\"$DNS_SRV1 $DNS_SRV2\""
+  [ -n "$VPN_DNS_SRV1" ] && [ -z "$VPN_DNS_SRV2" ] && DNS_SRVS="$DNS_SRV1"
+
+  # Create IPsec config
+  conf_bk "/etc/ipsec.conf"
+cat > /etc/ipsec.conf <<EOF
+version 2.0
+
+config setup
+  virtual-private=%v4:10.0.0.0/8,%v4:192.168.0.0/16,%v4:172.16.0.0/12,%v4:!$L2TP_NET,%v4:!$XAUTH_NET
+  uniqueids=no
+
+conn shared
+  left=%defaultroute
+  leftid=$public_ip
+  right=%any
+  encapsulation=yes
+  authby=secret
+  pfs=no
+  rekey=no
+  keyingtries=5
+  dpddelay=30
+  dpdtimeout=120
+  dpdaction=clear
+  ikev2=never
+  ike=aes256-sha2,aes128-sha2,aes256-sha1,aes128-sha1,aes256-sha2;modp1024,aes128-sha1;modp1024
+  phase2alg=aes_gcm-null,aes128-sha1,aes256-sha1,aes256-sha2_512,aes128-sha2,aes256-sha2
+  ikelifetime=24h
+  salifetime=24h
+  sha2-truncbug=no
+
+conn l2tp-psk
+  auto=add
+  leftprotoport=17/1701
+  rightprotoport=17/%any
+  type=transport
+  also=shared
+
+conn xauth-psk
+  auto=add
+  leftsubnet=0.0.0.0/0
+  rightaddresspool=$XAUTH_POOL
+  modecfgdns=$DNS_SRVS
+  leftxauthserver=yes
+  rightxauthclient=yes
+  leftmodecfgserver=yes
+  rightmodecfgclient=yes
+  modecfgpull=yes
+  cisco-unity=yes
+  also=shared
+
+include /etc/ipsec.d/*.conf
+EOF
+
+  if uname -m | grep -qi '^arm'; then
+    if ! modprobe -q sha512; then
+      sed -i '/phase2alg/s/,aes256-sha2_512//' /etc/ipsec.conf
+    fi
+  fi
+
+  # Specify IPsec PSK
+  conf_bk "/etc/ipsec.secrets"
+cat > /etc/ipsec.secrets <<EOF
+%any  %any  : PSK "$VPN_IPSEC_PSK"
+EOF
+
+  # Create xl2tpd config
+  conf_bk "/etc/xl2tpd/xl2tpd.conf"
+cat > /etc/xl2tpd/xl2tpd.conf <<EOF
+[global]
+port = 1701
+
+[lns default]
+ip range = $L2TP_POOL
+local ip = $L2TP_LOCAL
+require chap = yes
+refuse pap = yes
+require authentication = yes
+name = l2tpd
+pppoptfile = /etc/ppp/options.xl2tpd
+length bit = yes
+EOF
+
+  # Set xl2tpd options
+  conf_bk "/etc/ppp/options.xl2tpd"
+cat > /etc/ppp/options.xl2tpd <<EOF
+mschap-v2
+ipcp-accept-local
+ipcp-accept-remote
+noccp
+auth
+mtu 1280
+mru 1280
+proxyarp
+lcp-echo-failure 4
+lcp-echo-interval 30
+connect-delay 5000
+ms-dns $DNS_SRV1
+EOF
+
+  if [ -z "$VPN_DNS_SRV1" ] || [ -n "$VPN_DNS_SRV2" ]; then
+cat >> /etc/ppp/options.xl2tpd <<EOF
+ms-dns $DNS_SRV2
+EOF
+  fi
+
+  # Create VPN credentials
+  conf_bk "/etc/ppp/chap-secrets"
+cat > /etc/ppp/chap-secrets <<EOF
+"$VPN_USER" l2tpd "$VPN_PASSWORD" *
+EOF
+
+  conf_bk "/etc/ipsec.d/passwd"
+  VPN_PASSWORD_ENC=$(openssl passwd -1 "$VPN_PASSWORD")
+cat > /etc/ipsec.d/passwd <<EOF
+$VPN_USER:$VPN_PASSWORD_ENC:xauth-psk
+EOF
+}
+
+update_sysctl() {
+  bigecho "Updating sysctl settings..."
+  if ! grep -qs "hwdsl2 VPN script" /etc/sysctl.conf; then
+    conf_bk "/etc/sysctl.conf"
+cat >> /etc/sysctl.conf <<EOF
+
+# Added by hwdsl2 VPN script
+kernel.msgmnb = 65536
+kernel.msgmax = 65536
+
+net.ipv4.ip_forward = 1
+net.ipv4.conf.all.accept_redirects = 0
+net.ipv4.conf.all.send_redirects = 0
+net.ipv4.conf.all.rp_filter = 0
+net.ipv4.conf.default.accept_redirects = 0
+net.ipv4.conf.default.send_redirects = 0
+net.ipv4.conf.default.rp_filter = 0
+net.ipv4.conf.$NET_IFACE.send_redirects = 0
+net.ipv4.conf.$NET_IFACE.rp_filter = 0
+
+net.core.wmem_max = 12582912
+net.core.rmem_max = 12582912
+net.ipv4.tcp_rmem = 10240 87380 12582912
+net.ipv4.tcp_wmem = 10240 87380 12582912
+EOF
+  fi
+}
+
+update_iptables() {
+  bigecho "Updating IPTables rules..."
+  IPT_FILE=/etc/iptables.rules
+  ipt_flag=0
+  if ! grep -qs "hwdsl2 VPN script" "$IPT_FILE"; then
+    ipt_flag=1
+  fi
+
+  ipi='iptables -I INPUT'
+  ipf='iptables -I FORWARD'
+  ipp='iptables -t nat -I POSTROUTING'
+  res='RELATED,ESTABLISHED'
+  if [ "$ipt_flag" = "1" ]; then
+    service fail2ban stop >/dev/null 2>&1
+    iptables-save > "$IPT_FILE.old-$SYS_DT"
+    $ipi 1 -p udp --dport 1701 -m policy --dir in --pol none -j DROP
+    $ipi 2 -m conntrack --ctstate INVALID -j DROP
+    $ipi 3 -m conntrack --ctstate "$res" -j ACCEPT
+    $ipi 4 -p udp -m multiport --dports 500,4500 -j ACCEPT
+    $ipi 5 -p udp --dport 1701 -m policy --dir in --pol ipsec -j ACCEPT
+    $ipi 6 -p udp --dport 1701 -j DROP
+    $ipf 1 -m conntrack --ctstate INVALID -j DROP
+    $ipf 2 -i "$NET_IFACE" -o ppp+ -m conntrack --ctstate "$res" -j ACCEPT
+    $ipf 3 -i ppp+ -o "$NET_IFACE" -j ACCEPT
+    $ipf 4 -i ppp+ -o ppp+ -j ACCEPT
+    $ipf 5 -i "$NET_IFACE" -d "$XAUTH_NET" -m conntrack --ctstate "$res" -j ACCEPT
+    $ipf 6 -s "$XAUTH_NET" -o "$NET_IFACE" -j ACCEPT
+    $ipf 7 -s "$XAUTH_NET" -o ppp+ -j ACCEPT
+    iptables -A FORWARD -j DROP
+    $ipp -s "$XAUTH_NET" -o "$NET_IFACE" -m policy --dir out --pol none -j MASQUERADE
+    $ipp -s "$L2TP_NET" -o "$NET_IFACE" -j MASQUERADE
+    echo "# Modified by hwdsl2 VPN script" > "$IPT_FILE"
+    iptables-save >> "$IPT_FILE"
+  fi
+}
+
+enable_on_boot() {
+  bigecho "Enabling services on boot..."
+  mkdir -p /etc/network/if-pre-up.d
+cat > /etc/network/if-pre-up.d/iptablesload <<'EOF'
+#!/bin/sh
+iptables-restore < /etc/iptables.rules
+exit 0
+EOF
+  chmod +x /etc/network/if-pre-up.d/iptablesload
+
+  for svc in fail2ban ipsec xl2tpd; do
+    rc-update add "$svc" >/dev/null
+  done
+
+  if ! grep -qs "hwdsl2 VPN script" /etc/rc.local; then
+    if [ -f /etc/rc.local ]; then
+      conf_bk "/etc/rc.local"
+    else
+      echo '#!/bin/sh' > /etc/rc.local
+    fi
+cat >> /etc/rc.local <<'EOF'
+
+# Added by hwdsl2 VPN script
+(sleep 15
+service ipsec restart
+service xl2tpd restart
+echo 1 > /proc/sys/net/ipv4/ip_forward)&
+EOF
+  fi
+}
+
+start_services() {
+  bigecho "Starting services..."
+  sysctl -e -q -p
+
+  chmod +x /etc/rc.local
+  chmod 600 /etc/ipsec.secrets* /etc/ppp/chap-secrets* /etc/ipsec.d/passwd*
+
+  mkdir -p /run/pluto
+  service fail2ban restart >/dev/null 2>&1
+  service ipsec restart >/dev/null 2>&1
+  service xl2tpd restart >/dev/null 2>&1
+}
+
+show_vpn_info() {
+cat <<EOF
+
+================================================
+
+IPsec VPN server is now ready for use!
+
+Connect to your new VPN with these details:
+
+Server IP: $public_ip
+IPsec PSK: $VPN_IPSEC_PSK
+Username: $VPN_USER
+Password: $VPN_PASSWORD
+
+Write these down. You'll need them to connect!
+
+Important notes:   https://git.io/vpnnotes
+Setup VPN clients: https://git.io/vpnclients
+IKEv2 guide:       https://git.io/ikev2
+
+================================================
+
+EOF
+}
+
+check_swan_ver() {
+  swan_ver_url="https://dl.ls20.com/v1/$os_type/$os_ver/swanver?arch=$os_arch&ver=$SWAN_VER"
+  [ "$1" != "0" ] && swan_ver_url="$swan_ver_url&e=$2"
+  swan_ver_latest=$(wget -t 3 -T 15 -qO- "$swan_ver_url")
+  if printf '%s' "$swan_ver_latest" | grep -Eq '^([3-9]|[1-9][0-9]{1,2})(\.([0-9]|[1-9][0-9]{1,2})){1,2}$' \
+    && [ "$1" = "0" ] && [ -n "$SWAN_VER" ] && [ "$SWAN_VER" != "$swan_ver_latest" ] \
+    && printf '%s\n%s' "$SWAN_VER" "$swan_ver_latest" | sort -C -V; then
+cat <<EOF
+Note: A newer version of Libreswan ($swan_ver_latest) is available.
+      To update, run:
+      wget https://git.io/vpnupgrade -O vpnup.sh && sudo sh vpnup.sh
+
+EOF
+  fi
+}
+
+finish() {
+  check_swan_ver "$1" "$2"
+  exit "$1"
+}
+
+vpnsetup() {
+  check_root
+  check_vz
+  check_os
+  check_iface
+  check_creds
+  check_dns
+  start_setup
+  install_setup_pkgs
+  detect_ip
+  install_vpn_pkgs
+  install_fail2ban
+  get_ikev2_script
+  get_libreswan
+  install_libreswan
+  create_vpn_config
+  update_sysctl
+  update_iptables
+  enable_on_boot
+  start_services
+  show_vpn_info
+}
+
+## Defer setup until we have the complete script
+vpnsetup "$@"
+
+exit 0