Script on the intranet raspberry pi to reconnect the PPPoE internet connection in the TP-Link gateway. Notifies other devices using push notifs via Gotify server.

check-inet.sh

#!/bin/bash -e

######
# Installed under cron for root user
# sudo crontab -e
# * * * * * bash /home/marvin/cron-scripts/check-inet.sh >> /tmp/check-inet.log 2>&1
######

GATEWAY_IP=192.168.0.1
GATEWAY_AUTH="Basic <base64:userpass>"
AGENT=" Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.80 Safari/537.36"

check () {
  local STATE="error"
  for i in $(seq 1 $2); do
    STATE=$(ping -q -w 1 -c 1 "$1" > /dev/null && echo ok || echo error)
    [[ "$STATE" == "ok" ]] && echo "check:$1:connected:$1" && return 0
    sleep 1
    echo "check:$1:retry:$i"
  done

  return 1
}

check_gateway () {
  check `ip r | grep default | cut -d ' ' -f 3` 10
  STATE=$?
  return $STATE
}

check_internet_dns () {
  check 8.8.8.8 3
  STATE=$?
  return $STATE
}

inet_disconn () {
  echo "disconnecting..."
  curl -s "http://$GATEWAY_IP/cgi?7" -H "Origin: http://$GATEWAY_IP" -H 'Content-Type: text/plain' -H 'Accept: */*' -H "Cookie: Authorization=$GATEWAY_AUTH" --data-binary $'[ACT_PPP_DISCONN#1,1,1,0,0,0#0,0,0,0,0,0]0,0\r\n' -H 'Accept-Encoding: gzip, deflate' -H 'Content-Type: text/plain' -H 'Accept: */*' -H "Referer: http://$GATEWAY_IP/mainFrame.htm" -H 'Accept-Language: en-US,en;q=0.9' -H "User-Agent: $AGENT" --compressed --insecure > /dev/null
}

inet_conn () {
  echo "connecting..."
  curl -s "http://$GATEWAY_IP/cgi?7" -H "Origin: http://$GATEWAY_IP" -H 'Content-Type: text/plain' -H 'Accept: */*' -H "Cookie: Authorization=$GATEWAY_AUTH" --data-binary $'[ACT_PPP_CONN#1,1,1,0,0,0#0,0,0,0,0,0]0,0\r\n' -H 'Accept-Encoding: gzip, deflate' -H 'Content-Type: text/plain' -H 'Accept: */*' -H "Referer: http://$GATEWAY_IP/mainFrame.htm" -H 'Accept-Language: en-US,en;q=0.9' -H "User-Agent: $AGENT" --compressed --insecure > /dev/null
}

inet_reconn () {
  inet_disconn
  sleep 2
  inet_conn
}

check_gateway
GATEWAY_STATE=$?

if [[ $GATEWAY_STATE -eq 0 ]]; then
  check_internet_dns
  NET_STATE=$?

  if [[ $NET_STATE -eq 1 ]]; then
    was_down=1

    while [[ $was_down -eq 1 ]]; do
      inet_reconn
      sleep 5

      check_internet_dns
      NET_STATE=$?

      if [[ $NET_STATE -eq 0 ]]; then
        echo "NOW CONNECTED!"
        was_down=0
        /usr/local/bin/gotify push -t "Home Internet Status" -p 10 "ONLINE"
        break
      fi
    done

  else
    echo "NET IS UP!"
  fi
else
  echo "GATEWAY DONW!"
fi