wake-host

#! /bin/bash

usage="[--ssh-identity identity-file] host mac-address

wake 'host' with MAC address 'mac-address', using SSH identity given by
'identity-file'.

SSH is used to test that the host is up after trying to wake it."

# For Mac's, ping cannot be used to see if the host is up, because the 
# machine responds to pings even when asleep.

macprefixes="/usr/share/nmap/nmap-mac-prefixes"

set -eu
set -o pipefail

self="${BASH_SOURCE[0]}"
SCRIPTDIR=$(cd "$(dirname "$self")" && pwd)
argv0="$(basename "$self")"

function usage {
    [ "${*-}" ] && echo "$argv0: Error: $*" 1>&2
    echo "Usage: $argv0: $usage" 1>&2
    exit 1
}

function errordie {
    [ "${*-}" ] && echo "$argv0: Error: $*" 1>&2
    exit 1
}

for cmd in ether-wake start_caffeinate_daemon; do
    if ! type -p $cmd > /dev/null; then
	errordie command $cmd not found
    fi
done

debug=

function d {
    # "echo" and optionally execute the arguments to this function
    # if --debug is given to the main script, then just echo the
    # arguments.
    #
    # This can be used to run scripts with --debug so you can see what
    # commands they would execute.  This is good for script that do
    # possibly dangerous things.  Or operations which would take a
    # long time to execute and you want to make sure everything is OK before
    # trying it out.

    if [ "$debug" ]; then
	echo "would do: $*"
    else
	echo "+ $*"
        "$@"
    fi
}

host=
mac=
sshid=

while [ $# -gt 0 ]; do
    case $1 in
        --debug) debug=$1 ;;
        --ssh-identity)
	    [ $# -lt 2 ] && usage companion to --ssh-identity missing
	    shift
	    sshid=$1
	    ;;
        -*) usage ;;
        *)  [ $# -ne 2 ] && usage missing arguments
            host=$1
	    mac=$2
            break
            ;;
    esac
    shift
done

if [ ! -f "$macprefixes" ]; then
    echo $argv0: $macprefixes does not exist, install nmap
    exit 1
fi

ar=($mac)
prefix="$(echo ${ar[0]:0:8} | sed 's/://g')"
apple=
if grep -i $prefix $macprefixes | grep -iq apple; then
    apple=xxx
fi

if [ -e /sys/class/net/lan ]; then
    dev=lan
elif dev=$(/sbin/route -n | grep "^0.0.0.0" | rev | cut -d' ' -f1 | rev); then
    :
else
    echo $argv0: could not find ethernet device
    exit 1
fi

ssh=$(which ssh)
[ "$sshid" ] && ssh="$ssh -i $sshid"

if $ssh $host /bin/date > /dev/null; then
    echo $0: $host already awake
    exit 0
fi

echo $0: using device $dev and MAC $mac
sudo ether-wake -i $dev $mac
sleep 30
if $ssh $host /bin/date > /dev/null; then
    echo $0: successfully woke $host

    if [ "$apple" ]; then
	# Keep the host awake for 5 minutes, so whatever we wanted to do
	# has time to start
	seconds=$(( 5 * 60 ))
	echo $0: start caffeinate daemon for $seconds seconds
	if ! $ssh $host start_caffeinate_daemon $seconds; then
	    echo $0: failed to start caffeinate daemon
	    exit 1
	else
	    exit 0
	fi
    fi
else
    echo $0: could not wake $host
    exit 1
fi