Anyone reaching a TUIC port could start QUIC handshakes without ever
reading a reply, each holding state and goroutines, and an unauthenticated
connection got a handler goroutine per stream it opened. Both grew until
the panel ran out of memory.
The listener now counts connections from their first packet until they
authenticate or close: past 64 they must answer a stateless Retry, and
past 1024 in total or 32 per verified source (IPv4 address or IPv6 /64)
they are refused. Before authenticating, a connection may start at most
16 handlers per stream kind; further streams are reset.
MHSanaei