#!/bin/sh

INTERFACE="$1" # The interface which is brought up or down
STATUS="$2" # The new state of the interface

case "$STATUS" in
   'up') # $INTERFACE is up
       # Check to see if the interface added a default route
       /sbin/ip route list dev "$INTERFACE" 2>/dev/null | grep -q '^default' || exit 0

       /usr/libexec/chrony-helper is-running
       if [ $? -ne 0 ]; then
          systemctl --no-block start chronyd
       else
          /usr/libexec/chrony-helper command online >/dev/null 2>&1
       fi
   ;;
   'down') # $INTERFACE is down
       /sbin/ip route list 2>/dev/null | grep -q '^default' && exit 0

       /usr/libexec/chrony-helper command offline > /dev/null 2>&1
   ;;
esac