Wake On LAN on request

Question

I have a small home network with the router capable of running OpenWRT, is there some utility or firewall rule, which can be used to Wake On LAN on request. What I think - if I want to access my media centre (using for example SSH or HTTP) and it is suspended, is it possible to catch the ICMP packet (saying the machine is offline) and send the WOL packet to wakeup the machine and resend the SSH or HTTP request? Thanks

Answer 1

I want to do something like this too, and up till now the Apple "Sleep Proxy" was the only option I could find. "Sleep Proxy" is built in to Bonjour. There was some attempt to support this in OpenWRT but i'm not sure how far it got.

Here are some links:

http://en.wikipedia.org/wiki/Sleep_Proxy_Service
http://support.apple.com/kb/HT3774

Microsoft have also ripped it off:

http://www.networkworld.com/news/2010/061010-microsoft-sleep-proxy.html

But the iptables QUEUE idea looks pretty sweet. If you play around with this without delving into C, there are some nice looking python bindings here:

http://www.swende.se/index.php/2010/01/python-packet-play/

Answer 2

The iptables QUEUE target allows packets to be handled by a userspace program, written using libnetfilter_queue. Said program could parse the packet and then run ethtool in order to send the WoL packet to the appropriate system.