#!/bin/bash

VPN_HOSTNAME="gateway.something.com"
VPN_USERNAME="username"
VPN_PASSWORD="password"
VPN_KEY="imasupersecret"

cat >/etc/ipsec.conf <<EOF

    config setup

    conn %default
        ikelifetime=60m
        keylife=20m
        rekeymargin=3m
        keyingtries=1
        keyexchange=ikev1
        authby=secret
        ike=aes128-sha1-modp1024,3des-sha1-modp1024!
        esp=aes128-sha1-modp1024,3des-sha1-modp1024!

    conn vpnname
        keyexchange=ikev1
        left=%defaultroute
        auto=add
        authby=secret
        type=transport
        leftprotoport=17/1701
        rightprotoport=17/1701
        right=$VPN_HOSTNAME
EOF

cat >/etc/ipsec.secrets <<EOF
    : PSK $VPN_KEY
EOF

cat >/etc/xl2tpd/xl2tpd.conf <<EOF
    [lac vpnname]
    lns = $VPN_HOSTNAME
    ppp debug = yes
    pppoptfile = /etc/ppp/options.l2tpd.client
    length bit = yes
    bps = 1000000
EOF

cat >/etc/ppp/options.l2tpd.client <<EOF
    ipcp-accept-local
    ipcp-accept-remote
    refuse-eap
    require-pap
    noccp
    noauth
    idle 1800
    mtu 1410
    mru 1410
    defaultroute
    usepeerdns
    debug
    connect-delay 5000
EOF

echo "name  $VPN_USERNAME" >>/etc/ppp/options.l2tpd.client
echo "password $VPN_PASSWORD" >>/etc/ppp/options.l2tpd.client

mkdir -p /var/run/xl2tpd
touch /var/run/xl2tpd/l2tp-control
for i in strongswan.service xl2tpd.service; do systemctl start $i; done