Comments

1. Alex says:

   February 17, 2008 at 11:30 pm

   And tool for lazy – Wake-On-LAN over Internet with scheduling – http://www.rshut.com/wol

   Reply
2. Stuart says:

   March 4, 2011 at 9:16 pm

   Hi,
   Just what I was looking for :O) saved me some work, but I did find I needed to make some changes. The tcpdump filter wouldn’t work for magic packet sent over ethernet only, i.e. not UDP, so I changed the filter to capture both. Also The parsing didn’t work as it seems the MAC address is not repeated 16 times. Lastly, the “ps -p” didn’t work on my platform, so I made a more portable version checking for the PID. Attached is the updated script if you want it.

   I forgot, I also changed the packet parsing to break the packet up using the ffffffffffff in the packet as the two types of packet are of differnt lengths if using UDP or not, and also added a statement to determine the “main” ethernet interface of the machine so it would automatically work for devices other than eth0.

   Thanks again…
   Stuart/

   #!/bin/sh
   #Original Author:AppleGrew
   #License:GPL version 3

   #Forking to daemonize…
   if [[ "$2" != "forked" ]]
   then
   echo “Forking $0…”
   “$0″ “$1″ forked &
   echo “Forked.”
   exit 0
   fi

   #Creating pid file
   ppid=$$
   echo $ppid >”$1″

   echo “Started”
   interface=`route -n | grep “^0.0.0.0″ | awk -F ” ” ‘{print $8}’`
   mac=`ifconfig “$interface”|head -n1|sed -e ‘s/.*HWaddr \([0-9:a-fA-F]*\)/\1/g’ -e ‘s/://g’`
   pckt_expect=`echo “$mac $mac $mac $mac $mac $mac $mac $mac $mac $mac $mac $mac $mac $mac $mac $mac”|sed ‘s/ //g’|tr ‘A-Z’ ‘a-z’`
   while `true`
   do
   pckt_data=`tcpdump -i “$interface” -s 0 -x -c 1 \( \(ether dst “$mac” and not ip and not arp and not rarp\) or \(udp port 9\) \)`
   if [[ $? != 0 ]]
   then
   echo “tcpdump returned error.”
   exit 1
   fi
   pckt_data=`echo “$pckt_data” | \
   grep ’0x[0-9]*:’| \
   tr ‘A-Z’ ‘a-z’| \
   sed ‘s/[ \t]//g’| \
   sed ‘s/0x[0-9]*:\([0-9a-f]*\)/\1/g’| \
   tr -d ‘\n\r’ | \
   awk -F “ffffffffffff” ‘{print $2}’`
   if [[ "$pckt_data" == "$pckt_expect" ]]
   then
   echo “Matched! Received Magic packet shutting down…”
   rm -f $1
   /sbin/poweroff
   exit 0
   fi
   done

   echo “EXITED”
   exit 0

   Reply
3. Apple Grew says:

   March 4, 2011 at 9:34 pm

   That’s great Stuart. I have added your code to my post.

   Reply