Script to reset Bell Canada modem

#!/bin/sh

# Script to check if internet is reachable and if not reset BELL modem
# DATE=$(date +'%d/%m/%Y %H:%M:%S')
# echo "********** $DATE WIRELESS CHECK STARTED **********"

# if script already running -> exit
if [ -f /home/se/checking-internet ]; then
  # echo "Script already running. Exiting now..."
  exit
fi
# Create lockfile
touch /home/se/checking-internet

# Check if Ipadress has changed
ipcheck () {
  curr_ip=$(curl --silent --max-time 5 http://ipecho.net/plain)

  # If curl was successfull compare old ip with current ip
  if [ $? -eq 0 ] && [ ! -z "$curr_ip" ]; then
    #echo "Current IP is: $curr_ip"
    old_ip=`cat /home/se/ipaddress`
    #echo "Old IP was: $old_ip"

    # If Ip differs write log
    if [ "$old_ip" != "$curr_ip" ]; then
      change_date=$(date +'%d/%m/%Y %H:%M:%S')
      echo "$change_date: Adress has changed from $old_ip to $curr_ip \n\n"
      # Write new IP into file
      echo "$curr_ip" > /home/se/ipaddress
    fi

  # If curl fail, just ignore
  else
    change_date=$(date +'%d/%m/%Y %H:%M:%S')
    # echo "$change_date: Could not determine external IP. Ignored.\n\n"
  fi
}

# Check if internet is reachable
start_time=`date +%s`
a=0
reachable=0
# Try 3 times for max. 20min each to see if internet works.
# Multiple times prevents modem reboot due to temporary DNS errors
# If Bell transiently block internet access the we have up to 1h patience
while [ $a -lt 3 ]; do
  curl --silent --show-error --max-time 3 --retry 9 --retry-max-time 600 --head www.google.ca >/dev/null
  if [ $? -eq 0 ];then
    reachable=1
    break
  else
    a=`expr $a + 1`
    sleep 10
  fi
done

# Computing runtime
end_time=`date +%s`
run_time=$((end_time-start_time))
run_min=`date -u -d @${run_time} +"%T"`

# If reachable during the course of all curl retries
if [ $reachable -eq 1 ]; then
  # If internet reachable within a minute: check ip and exit (normal case)
  if [ $run_time -le 60 ]; then
    # echo "Internet running fine. Checking if IP has changed."
    ipcheck
    rm /home/se/checking-internet
    exit
  # If internet is reachable after some tries, echo to log
  else
    echo "Internet was not reachable for $run_min (h:m:s)"
    reach_time=$(date +'%d.%m.%Y %H:%M:%S')
    echo "Since $reach_time internet is reachable again.\n\n"
    # Check if IP has changed
    ipcheck
    rm /home/se/checking-internet
    exit
  fi
fi

# If not reachable check if router is reachable
change_date=$(date +'%d/%m/%Y %H:%M:%S')
echo "$change_date: Internet not reachable since $run_min (h:m:s). Pinging router..."
ping -c 3 -W 10 192.168.12.1 >/dev/null

# If not reachable - reset wlan connection
if [ $? -ne 0 ]; then
  echo 'Router not reachable. Reseting wireless.'
  service network-manager restart
  sleep 5
  echo "Exiting..."
  rm /home/se/checking-internet
  exit
# if router is reachable, modem must be crashed
else
  echo "Router is reachable. Taking modem down"
  curl --silent --user admin:admin -d "action=submit&page=resets&factory_reset=reboot" 192.168.2.1
  echo "Modem rebooting. Waiting 5min..."
  sleep 300
  echo "Exiting...\n\n"
  rm /home/se/checking-internet
  exit
fi