Script to update Wireguard routes in DD-WRT

custom.sh

#!/bin/bash 

while : 
do 
  WGPROC=$(wg) 
  WGIF=$(ip route show gateway | grep -io oet1) 
  WGSERVER=$(/usr/sbin/nvram get oet1_rem0) 
  WANGWY=$(/usr/sbin/nvram get wan_gateway) 
  WANIF=$(/usr/sbin/nvram get wan_iface) 
  
  if ! [[ $WGSERVER =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
    echo "Resolving hostname $WGSERVER..."
    WGSERVER=$(nslookup $WGSERVER 1.1.1.1 | awk '/Name/,/END/' | grep Address | awk -v RS='([0-9]+\\.){3}[0-9]+' 'RT{print RT}' | head -n 1)
    echo "Resolved to $WGSERVER"
  fi
  
  HOST=$(ip route | grep -E "($WGSERVER.*$WANGWY)") 

  until /usr/sbin/nvram get wanup | grep -q 1 ; do 
    echo "Waiting for WAN to initialize..." 
    sleep 10 
  done 
  
  if [ "$WGPROC" ] ; then 
    echo "Wireguard is running. Checking routes..." 
  
    if [ ! "$WGIF" ] || [ ! "$HOST" ] ; then 
      echo "Routes missing. Correcting..." 
      route add -host $WGSERVER gw $WANGWY dev $WANIF 
      route del default 
      route add default dev oet1 
      ip route flush cache 
      echo "Done" 
      echo ""
      curl ipinfo.io 
      echo ""
    else 
      echo "Routes are correct" 
    fi 
  else 
    echo "Wireguard is not running" 
  fi 
  sleep 60 
done