=-=-=-=-=-=-=-=-=-=-=-=-=-=
#! /bin/bash

DEV=
LOCAL_IP=23.111.92.132

OFFSET=40

if ip link sh qrtun &>/dev/null; then
    echo 'Tunnel is set up already, nothing to do.' >&2
    exit -1
fi

if [ -z "$DEV" ]; then
    echo '$DEV unset'
    exit -1
fi

if [ -z "$LOCAL_IP" ]; then
    echo '$LOCAL_IP unset'
    exit -1
fi

if ! modprobe ipip; then
    echo 'Failed to load ipip module'
    exit -1
fi

if ! grep -q qrtun_route /etc/iproute2/rt_tables; then
    if egrep -q '^[[:space:]]*'$OFFSET'[[:space:]]' /etc/iproute2/rt_tables; then
        echo Cannot append appropriate lines to /etc/iproute2/rt_tables. >&2
        echo You need to set up qrtun_route table yourself. >&2
        exit
    else
        echo ' '$OFFSET' qrtun_route' >> /etc/iproute2/rt_tables
    fi
fi

echo -n Setting up tunnel... >&2

src=172.16.108.60
dst=172.16.208.60

ip tunnel add qrtun mode ipip remote 185.104.208.60 local $LOCAL_IP ttl 64 dev $DEV

ip address add $src peer $dst/32 dev qrtun
ip link set qrtun up
ip rule add from $src table qrtun_route
ip route add default dev qrtun table qrtun_route

echo ' done'. >&2
=-=-=-=-=-=-=-=-=-=-=-=-=-=

// Qrator Labs Support