tree bd73f1d3ebb8cdc3d7e9d11cab9daab5b9a10345
parent 82f081974059c0d90519b2fc17ac65268f1b9d25
author Peter McCurdy <pmccurdy@google.com> 1481341337 -0500
committer Peter McCurdy <pmccurdy@google.com> 1485904974 -0500

isoping: Perform a handshake on new client connections.

Since isoping communicates over UDP, there's no built-in protections against an
attacker sending us spoofed packets.  Before allocating any memory, reply with a
cookie based on the client's IP address and port, and don't start sending data
until we see that cookie come back from the client.

We also have to resend handshake packets from the client, to avoid getting stuck
if one of the initial packets gets lost.

Change-Id: Icca7d341757279e49d55aa715fbd3f971b615e9f