Scapy sniff() should run in a separate thread and be stoppable
We want the ability to have scapy start sniffing on the selected interface when the test starts and have it stop when the test has finished.
The problem is that the scapy sniff() call in the stable version does not have an easy way of telling it when it should stop sniffing.
There is a patch for sniff() to allow the termination of sniff() based on the return value of a function: