NetworkManager Connection Guarder

GUARDER

#!/bin/bash
# put me in the directory of "/etc/NetworkManager/dispatcher.d/",permission `u+x,g-w,o-w`
GUARDED_CONNECTION_NAMES='SSTP'

CONTROL_FILE=/tmp/NM-CONN-GUARD-DISABLED

if [ -f "$CONTROL_FILE" ] || [ -f "$CONTROL_FILE-$CONNECTION_ID" ]; then
   echo -n "VPN GUARD DISABLED"
   [ -f "$CONTROL_FILE-$CONNECTION_ID" ] && echo -n " FOR CONNECTION ${CONNECTION_ID}"
   echo ""
   exit 0
fi

[[ "vpn-down vpn-up up down connectivity-change" == *"${NM_DISPATCHER_ACTION}"* ]] || exit 0

for GUARDED_CONNECTION_NAME in ${GUARDED_CONNECTION_NAMES}; do
   if [[ "${NM_DISPATCHER_ACTION}" == *"up" ]] && [ "${CONNECTION_ID}" = "${GUARDED_CONNECTION_NAME}" ]; then ## no action on self up and down
      exit 0
   fi
   (
      sleep 2
      ## nmcli c d "${GUARDED_CONNECTION_NAME}" ## if unplug the connection, the previous connection may still keep active in a shot time
      for __ in {1..20}; do # try at most 20 times,about 40 seconds
         [ "$(nmcli c s --active "${GUARDED_CONNECTION_NAME}")" != "" ] && break
         nmcli c u "${GUARDED_CONNECTION_NAME}" && break
         sleep 2
      done
   ) &
done