ZJU Zijingang Campus dormitory VPN dial up script (xl2tpd + systemd, for Archlinux)

vpn-dorm.sh

#!/bin/bash

PPP_TIMEOUT=30
L2TPD_TIMEOUT=5
L2TPD_CONTROL_FILE=/var/run/xl2tpd/l2tp-control
VPN_ACCOUNT=zjuvpn

function start_xl2tpd
{
	systemctl start xl2tpd
	for i in $(seq 0 $L2TPD_TIMEOUT)
	do
		if [ -e $L2TPD_CONTROL_FILE ]; then
			return 0
		fi
		sleep 1
	done
	return 1
}

if [ -e $L2TPD_CONTROL_FILE ]; then
	xl2tpd-control disconnect $VPN_ACCOUNT
	systemctl stop xl2tpd
fi

if ! start_xl2tpd; then
	echo "Failed starting xl2tpd"
	return 1
fi

GW=`ip route show 0/0 | cut -d " " -f 3`

if [ ! -z $GW ]; then
	#Attention here! Intranet 10.0.0.0/8(except the DNS) must be connected through VPN in dorm.
	ip route add 10.5.1.0/24 via $GW
	ip route add 10.10.0.0/24 via $GW
	ip route del default
fi

xl2tpd-control connect $VPN_ACCOUNT

for i in $(seq 0 $PPP_TIMEOUT)
do
	if ip addr show | grep 'inet.*ppp0' > /dev/null; then
		#ip route flush root 10.0.0.0/8 dev ppp0
		ip route add default dev ppp0
		if ! grep '114' /etc/resolv.conf > /dev/null; then
			echo "nameserver 114.114.114.114" >> /etc/resolv.conf
			echo "nameserver 114.114.115.115" >> /etc/resolv.conf
		fi
		echo "Connected"
		exit 0
	fi
	sleep 1
done

xl2tpd-control disconnect $VPN_ACCOUNT
systemctl stop xl2tpd

echo "Connection time out"
exit 1