#!/bin/sh
#
# Try to detect when the optical link gets into an unrecoverable state and
# attempt to reboot the system to recover it.
# Workaround for b/32097608 until a better solution can be found.

. /etc/utils.sh

GPON_ALARM_FILE="/sys/devices/platform/gpon/info/alarmGpon"
GPON_INFO_FILE="/sys/devices/platform/gpon/info/infoGpon"

WARN1_TIME=60  # seconds
WARN2_TIME=120  # seconds
REBOOT_TIME=180  # seconds

is_optical_link_up() {
  if [ ! -e "$GPON_INFO_FILE" ]; then
    echo "$GPON_INFO_FILE does not exist yet!"
    return 1
  fi
  x=$(cat "$GPON_INFO_FILE" | grep "ONU STATE")
  contains "$x" "OPERATION"
}

START_TIME=$(date +%s)
while true; do
  if [ ! -e "$GPON_ALARM_FILE" ]; then
    echo "$GPON_ALARM_FILE does not exist yet! Optical stack not running?"
    exit 1
  fi
  los_bit=$(cat "$GPON_ALARM_FILE" | grep "LOS")
  if contains "$los_bit" "ON"; then
    echo "LOS alarm is ON! Cable unplugged? Stopping the reboot timer!"
    exit 1
  fi
  if is_optical_link_up; then
    echo "Optical link is up! Stopping the reboot timer!"
    exit 1
  fi
  # Default sleep for 30 seconds then sleep for a random interval up to an
  # additional 30 seconds.
  sleep 30
  sleep $(randint 30)
  CURR_TIME=$(($(date +%s) - START_TIME))
  if [ "$CURR_TIME" -ge "$REBOOT_TIME" ]; then
    echo "Optical link is STILL DOWN after $CURR_TIME seconds..."
    echo "OPTICAL WATCHDOG IS REBOOTING THE SYSTEM NOW!"
    reboot
  elif [ "$CURR_TIME" -ge "$WARN2_TIME" ]; then
    echo "Optical link NOT UP after $CURR_TIME seconds! Will reboot soon..."
  elif [ "$CURR_TIME" -ge "$WARN1_TIME" ]; then
    echo "Optical link is not up after $CURR_TIME seconds..."
  fi
done

# Make sure that babysitter always restarts us.
exit 1