#!/bin/sh # # Script for automatic setup of an IPsec VPN server on Ubuntu LTS and Debian. # Works on any dedicated server or virtual private server (VPS) except OpenVZ. # # 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) 2014-2017 Lin Song # Based on the work of Thomas Sarlandie (Copyright 2012) # # 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 # ===================================================== export PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin" SYS_DT="$(date +%F-%T)" exiterr() { echo "Error: $1" >&2; exit 1; } exiterr2() { exiterr "'apt-get install' failed."; } conf_bk() { /bin/cp -f "$1" "$1.old-$SYS_DT" 2>/dev/null; } bigecho() { echo; echo "## $1"; echo; } check_ip() { IP_REGEX='^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$' printf '%s' "$1" | tr -d '\n' | grep -Eq "$IP_REGEX" } vpnsetup() { os_type="$(lsb_release -si 2>/dev/null)" if [ -z "$os_type" ]; then [ -f /etc/os-release ] && os_type="$(. /etc/os-release && echo "$ID")" [ -f /etc/lsb-release ] && os_type="$(. /etc/lsb-release && echo "$DISTRIB_ID")" fi if ! printf '%s' "$os_type" | head -n 1 | grep -qiF -e ubuntu -e debian -e raspbian; then exiterr "This script only supports Ubuntu and Debian." fi if [ "$(sed 's/\..*//' /etc/debian_version)" = "7" ]; then exiterr "Debian 7 is not supported." fi if [ -f /proc/user_beancounters ]; then exiterr "OpenVZ VPS is not supported. Try OpenVPN: github.com/Nyr/openvpn-install" fi if [ "$(id -u)" != 0 ]; then exiterr "Script must be run as root. Try 'sudo sh $0'" fi case "$(uname -r)" in 4.14*|4.15*) exiterr "Linux kernels 4.14/4.15 are not yet supported due to an xl2tpd bug." ;; esac net_iface=${VPN_NET_IFACE:-'eth0'} def_iface="$(route 2>/dev/null | grep '^default' | grep -o '[^ ]*$')" [ -z "$def_iface" ] && def_iface="$(ip -4 route list 0/0 2>/dev/null | grep -Po '(?<=dev )(\S+)')" def_iface_state=$(cat "/sys/class/net/$def_iface/operstate" 2>/dev/null) if [ -n "$def_iface_state" ] && [ "$def_iface_state" != "down" ]; then if [ "$(uname -m | cut -c1-3)" != "arm" ]; 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="$def_iface" fi net_iface_state=$(cat "/sys/class/net/$net_iface/operstate" 2>/dev/null) if [ -z "$net_iface_state" ] || [ "$net_iface_state" = "down" ] || [ "$net_iface" = "lo" ]; then printf "Error: Network interface '%s' is not available.\n" "$net_iface" >&2 if [ -z "$VPN_NET_IFACE" ]; then cat 1>&2 </dev/null 2>&1; do [ "$count" -ge "20" ] && exiterr "Cannot get apt/dpkg lock." count=$((count+1)) printf '%s' '.' sleep 3 done export DEBIAN_FRONTEND=noninteractive apt-get -yq update || exiterr "'apt-get update' failed." bigecho "Installing packages required for setup..." apt-get -yq install wget dnsutils openssl \ iptables iproute2 gawk grep sed net-tools || exiterr2 bigecho "Trying to auto discover IP of this server..." cat <<'EOF' In case the script hangs here for more than a few minutes, press Ctrl-C to abort. Then edit it and manually enter IP. EOF # In case auto IP discovery fails, enter server's public IP here. PUBLIC_IP=${VPN_PUBLIC_IP:-''} # Try to auto discover IP of this server [ -z "$PUBLIC_IP" ] && PUBLIC_IP=$(dig @resolver1.opendns.com -t A -4 myip.opendns.com +short) # Check IP for correct format check_ip "$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. Edit the script and manually enter it." bigecho "Installing packages required for the VPN..." apt-get -yq install libnss3-dev libnspr4-dev pkg-config \ libpam0g-dev libcap-ng-dev libcap-ng-utils libselinux1-dev \ libcurl4-nss-dev flex bison gcc make libnss3-tools \ libevent-dev ppp xl2tpd || exiterr2 bigecho "Installing Fail2Ban to protect SSH..." apt-get -yq install fail2ban || exiterr2 bigecho "Compiling and installing Libreswan..." SWAN_VER=3.23 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/$swan_file" if ! { wget -t 3 -T 30 -nv -O "$swan_file" "$swan_url1" || wget -t 3 -T 30 -nv -O "$swan_file" "$swan_url2"; }; then exiterr "Cannot download Libreswan source." fi /bin/rm -rf "/opt/src/libreswan-$SWAN_VER" tar xzf "$swan_file" && /bin/rm -f "$swan_file" cd "libreswan-$SWAN_VER" || exiterr "Cannot enter Libreswan source dir." sed -i '/docker-targets\.mk/d' Makefile cat > Makefile.inc.local <<'EOF' WERROR_CFLAGS = USE_DNSSEC = false EOF if [ "$(packaging/utils/lswan_detect.sh init)" = "systemd" ]; then apt-get -yq install libsystemd-dev || exiterr2 fi NPROCS="$(grep -c ^processor /proc/cpuinfo)" [ -z "$NPROCS" ] && NPROCS=1 make "-j$((NPROCS+1))" -s base && make -s install-base # Verify the install and clean up cd /opt/src || exiterr "Cannot enter /opt/src." /bin/rm -rf "/opt/src/libreswan-$SWAN_VER" if ! /usr/local/sbin/ipsec --version 2>/dev/null | grep -qF "$SWAN_VER"; then exiterr "Libreswan $SWAN_VER failed to build." fi bigecho "Creating VPN configuration..." L2TP_NET=${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'} # Create IPsec (Libreswan) config conf_bk "/etc/ipsec.conf" cat > /etc/ipsec.conf < /etc/ipsec.secrets < /etc/xl2tpd/xl2tpd.conf < /etc/ppp/options.xl2tpd < /etc/ppp/chap-secrets < /etc/ipsec.d/passwd <> /etc/sysctl.conf </dev/null \ || ! iptables -t nat -C POSTROUTING -s "$XAUTH_NET" -o "$net_iface" -m policy --dir out --pol none -j MASQUERADE 2>/dev/null; then ipt_flag=1 fi # Add IPTables rules for VPN if [ "$ipt_flag" = "1" ]; then service fail2ban stop >/dev/null 2>&1 iptables-save > "$IPT_FILE.old-$SYS_DT" iptables -I INPUT 1 -p udp --dport 1701 -m policy --dir in --pol none -j DROP iptables -I INPUT 2 -m conntrack --ctstate INVALID -j DROP iptables -I INPUT 3 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT iptables -I INPUT 4 -p udp -m multiport --dports 500,4500 -j ACCEPT iptables -I INPUT 5 -p udp --dport 1701 -m policy --dir in --pol ipsec -j ACCEPT iptables -I INPUT 6 -p udp --dport 1701 -j DROP iptables -I FORWARD 1 -m conntrack --ctstate INVALID -j DROP iptables -I FORWARD 2 -i "$net_iface" -o ppp+ -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT iptables -I FORWARD 3 -i ppp+ -o "$net_iface" -j ACCEPT iptables -I FORWARD 4 -i ppp+ -o ppp+ -s "$L2TP_NET" -d "$L2TP_NET" -j ACCEPT iptables -I FORWARD 5 -i "$net_iface" -d "$XAUTH_NET" -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT iptables -I FORWARD 6 -s "$XAUTH_NET" -o "$net_iface" -j ACCEPT # Uncomment if you wish to disallow traffic between VPN clients themselves # iptables -I FORWARD 2 -i ppp+ -o ppp+ -s "$L2TP_NET" -d "$L2TP_NET" -j DROP # iptables -I FORWARD 3 -s "$XAUTH_NET" -d "$XAUTH_NET" -j DROP iptables -A FORWARD -j DROP iptables -t nat -I POSTROUTING -s "$XAUTH_NET" -o "$net_iface" -m policy --dir out --pol none -j MASQUERADE iptables -t nat -I POSTROUTING -s "$L2TP_NET" -o "$net_iface" -j MASQUERADE echo "# Modified by hwdsl2 VPN script" > "$IPT_FILE" iptables-save >> "$IPT_FILE" # Update rules for iptables-persistent IPT_FILE2="/etc/iptables/rules.v4" if [ -f "$IPT_FILE2" ]; then conf_bk "$IPT_FILE2" /bin/cp -f "$IPT_FILE" "$IPT_FILE2" fi fi bigecho "Enabling services on boot..." mkdir -p /etc/network/if-pre-up.d cat > /etc/network/if-pre-up.d/iptablesload <<'EOF' #!/bin/sh iptables-restore < /etc/iptables.rules exit 0 EOF for svc in fail2ban ipsec xl2tpd; do update-rc.d "$svc" enable >/dev/null 2>&1 systemctl enable "$svc" 2>/dev/null done if ! grep -qs "hwdsl2 VPN script" /etc/rc.local; then if [ -f /etc/rc.local ]; then conf_bk "/etc/rc.local" sed --follow-symlinks -i '/^exit 0/d' /etc/rc.local else echo '#!/bin/sh' > /etc/rc.local fi cat >> /etc/rc.local <<'EOF' # Added by hwdsl2 VPN script (sleep 15 service ipsec restart service xl2tpd restart [ -f "/usr/sbin/netplan" ] && { iptables-restore < /etc/iptables.rules; service fail2ban restart; } echo 1 > /proc/sys/net/ipv4/ip_forward)& exit 0 EOF fi bigecho "Starting services..." # Reload sysctl.conf sysctl -e -q -p # Update file attributes chmod +x /etc/rc.local /etc/network/if-pre-up.d/iptablesload chmod 600 /etc/ipsec.secrets* /etc/ppp/chap-secrets* /etc/ipsec.d/passwd* # Apply new IPTables rules iptables-restore < "$IPT_FILE" # Restart services service fail2ban restart 2>/dev/null service ipsec restart 2>/dev/null service xl2tpd restart 2>/dev/null cat <