tree 0a6a5ca5b14e922072b1012c2559ce4f4d5e46a7
parent 28ddb13819baf78fd39d9681f3f5fd4681450613
author Alessandro Ghedini <alessandro@ghedini.me> 1580812110 +0100
committer Alessandro Ghedini <alessandro@ghedini.me> 1580822036 +0100

examples: deterministically generate source conn ID on servers

When we receive a ClientHello split across multiple Initial packets we
end up creating multiple connections in the example servers due to the
fact that we only store the server-generated destination connection ID,
and not the original client-generated destination connection ID, in the
HashMap used to associate incoming packets to connections.

This changes how we generate the server-generated destination connection
ID by making it more deterministic and based on the client-generated
connection ID, and then do a double lookup for both the raw dcid and the
deterministically-generated one.

Unfortunately due to the fact that we use the normal Rust HashMap we
can't have multiple keys pointing to the same connection, so we can't
store the client-generated connection ID directly. In practice we could
have a double layer HashMap, but then we'd run into problems when
removing connections because we might not have the original destination
connection ID (e.g. when we don't do Retry), so we would leak memory.