#!/bin/bash

IF=$1
STATUS=$2

function status_knockd()
{
    regexp="active \(([a-z]+)\)"
    status=$(systemctl status knockd)

    [[ $status =~ $regexp ]]
    match="${BASH_REMATCH[1]}"

    if [ ${match} == "exited" ]; then
        # active (exited)
        echo "e"
    elif [ ${match} == "running" ]; then
        # active (running)
        echo "r"
    else
        # inactive (dead)
        echo "x"
    fi
}

function start_knockd()
{
    result=$(knockd_status)

    case "$result" in
        e)
        systemctl stop knockd
        systemctl start knockd
        ;;
        r)
        ;;
        *)
        systemctl start knockd
        ;;
    esac
}

function stop_knockd()
{
    result=$(knockd_status)

    case "$result" in
        x)
        ;;
        *)
        systemctl stop knockd
        ;;
    esac
}

if [ "$IF" == "wlan0" ]
then
    case "$2" in
        up)
        logger -s "NM-knockd: 'up' triggered: starting knockd"
        start_knockd
        ;;
        down)
        logger -s "NM-knockd: 'down' triggered: stopping knockd"
        stop_knockd
        ;;
        *)
        ;;
    esac
fi