xl2tpd により L2TP コネクションが確立した際に自動的に経路を追加するスクリプト

00-route.sh

#!/bin/sh

# This script is run by pppd after the link is established.
# It executes all the scripts available in /etc/ppp/ip-up.d directory,
# with the following parameters:
# $1 = interface name (e.g. ppp0)
# $2 = tty device
# $3 = speed
# $4 = local IP address
# $5 = remote IP address
# $6 = ipparam (user specified parameter, see man pppd)

function getConnStatus() {
    /sbin/ifconfig $1 | grep 'inet ' | wc -l
}

function getGatewayIp() {
    /sbin/route -n | grep -m 1 "^0\.0\.0\.0" | awk '{print $2}'
}

if [ $(getConnStatus wlp3s0) -gt 0 ]; then
    if='wlp3s0'
elif [ $(getConnStatus enp1s0) -gt 0 ]; then
    if='enp1s0'
else
    echo 'Unsupported interface.'
    exit 1
fi

/usr/bin/ip route add ***.***.***.*** via $(getGatewayIp $if) dev $if
/usr/bin/ip route add default via $5