Only the receive timeout is hooked up yet. You can change the timeout by
calling setsockopt(..., SOL_SOCKET, SO_RCVTIMEO, ...).
Use this mechanism to make /bin/ping report timeouts.
It's now actually possible to ping other hosts on the network! :^)
I've switched the "run" script over to starting QEMU with user networking
since that works better for my testing needs right now.