autowake_NAS

#!/bin/sh
#############################################################################
# Script aimed at waking a (NAS) computer according to various conditions.
# - If at least one of a configurable set of devices is online
# - Unless a curfew timeslot is defined and the current time is
#   within this slot
# - Every day at configurable time
#
# This script was developped to be executed on a DD-WRT router.
# The script shall be launched at router startup
#
# Configuration of the script:
# - This script does not accept any argument when calling it
# - The behaviour of the script can be configured by changing the value
#   of the variables in capital letters below
#
# Author: fritz from NAS4Free forum
#
#############################################################################

# script configuration
POLL_INTERVAL=5                         # number of seconds to wait between to cycles

BROADCAST_IP="100.200.1.255"            # Broadcast IP address of the network
NAS_IP="100.200.1.108"                  # IP address of the NAS to wake
NAS_MAC="F4:6D:04:AE:79:24"             # MAC address of the NAS to wake
WOL_PORT="9"                            # Usually 7 or 9

# IP addresses of the devices to be polled, separated by a space character)
# (Attention: The devices to be polled shall have static IP addresses!)
# The script will ensure that the NAS is awake, whenever one of the
# devices having the latter IP addresses is online
#
# The devices will be polled only if CHECK_ONLINE equals 1
CHECK_ONLINE="1"
IP_ADDRS="100.200.1.112"

# Curfew:
# Time of the day at which the NAS shall not be woken up
# (even if some of the above mentionned devices are online)
#
# The curfew time exists if CHECK_CURFEW_ACTIVE equals 1
CHECK_CURFEW_ACTIVE="1"
BEG_POLL_CURFEW="23:00"
END_POLL_CURFEW="6:00"

# Time of the day at which the NAS shall always by awake
# (even if none of the above mentionned devices are online)
# This may be required in order to ensure that the NAS performs
# some administrative tasks (e.g. backup)
# format: "hh:mm"
#
# Wake time is taken into account if CHECK_WAKE_TIME equals 1
CHECK_WAKE_TIME="1"
WAKE_TIME="6:00"

# Used utilities
DATE="/bin/date"
PING="/bin/ping"
WOL="/usr/bin/wol"

# Constants
NB_SEC_IN_DAY="86400"

# Initialization of variables
next_wake_timestamp=`$DATE -d "2030-01-01 00:00" +%s`



##################################
# Returns true if the current time is within the timeslot
# provided as parameter.
#
# Param 1: Start of the timeslot (format: "hh:mm")
# Param 2: End of the timeslot (format: "hh:mm"). If End=Beg,
#           the timeslot is considered to last the whole day.
# Return: 0 if the current time is within the timeslot
##################################
isInTimeSlot() {

        local startTime
        local endTime
        startTime="$1"
        endTime="$2"

        local nbSecInDay
        nbSecInDay="86400"

        local currentTimestamp
        local startTimestamp
        local endTimestamp

        currentTimestamp=`$DATE +"%s"`
        startTimestamp=`$DATE -d "$startTime:00" +"%s"`
        endTimestamp=`$DATE -d "$endTime:00" +"%s"`

        if [ "$endTimestamp" -le "$startTimestamp" ]; then
                if [ "$currentTimestamp" -gt "$startTimestamp" ]; then
                        endTimestamp=`expr $endTimestamp + $nbSecInDay`
                else
                        startTimestamp=`expr $startTimestamp - $nbSecInDay`
                fi
        fi

        if [ "$currentTimestamp" -gt "$startTimestamp" -a "$currentTimestamp" -le "$endTimestamp" ]; then
                return 0
        else
                return 1
        fi
}



while true
do

        # Wait until next poll
        sleep $POLL_INTERVAL

        echo "---------------------"

        # Check if the NAS is already awake
        if ping -c 1 -t 1 $NAS_IP > /dev/null; then
                echo "NAS is already ONLINE"
                continue
        else
                echo "NAS is OFFLINE"
        fi

        # Initialize variable stating if NAS shall be waken
        wake_nas="0"

        # Check if any device requiring the NAS to be awake is online

        # Only wake NAS if we are not within the curfew timeslot
        isInTimeSlot "$BEG_POLL_CURFEW" "$END_POLL_CURFEW"
        inTimeSlot=$?
        if [ $CHECK_CURFEW_ACTIVE -eq "0" -o $inTimeSlot -eq "1" ]; then
                if [ $CHECK_ONLINE -eq "1" ]; then
                        for ip_addr in $IP_ADDRS; do
                                if $PING -c 1 -t 1 $ip_addr > /dev/null ; then
                                        wake_nas="1"
                                        echo "Online device detected: $ip_addr"
                                        break # Checking the other devices skipped to save time
                                fi
                        done
                fi
        else
                echo "Within curfew timeslot"
        fi

        # Check if it is time to wake NAS
        if [ $CHECK_WAKE_TIME -eq "1" ]; then
                # Record current time
                current_timestamp=`$DATE +%s`

                # Check if wake time is reached
                if [ $next_wake_timestamp -le $current_timestamp ]; then
                        wake_nas="1"
                        echo "Time to wake up !!!"
                fi

                # Compute next wake timestamp
                next_wake_timestamp=`$DATE -d "$WAKE_TIME" +%s`
                # If the next wake time is tomorrow
                if [ $next_wake_timestamp -le $current_timestamp ]; then
                        next_wake_timestamp=`expr $next_wake_timestamp + $NB_SEC_IN_DAY`
                fi
        fi

        # Wake NAS if required
        if [ "$wake_nas" -eq "1" ]; then
                echo "Waking NAS"
                $WOL -i $BROADCAST_IP -p $WOL_PORT $NAS_MAC
        else
                echo "No need to wake NAS"
        fi
done