The main goal of this refactor is to remove a
`RefCell` that is preventing
`Connection` from being `Sync`.
This is achieved by replacing it with a
monotonically decreasing 'recency' counter.
See #1769 for more information.
With Rust 1.63.0 one can initialize a `std::array` via `std::array::from_fn`.
https://doc.rust-lang.org/std/array/fn.from_fn.html
Thus there is no need to start with an uninitialized array via `MaybeUninit`,
initialize it and then use `unsafe` to `assume_init`. Instead one can initialize
the array with the concrete elements right away.
Reduces the amount of work done for connection attempts that will be
refused or ignored when the application layer can do so
cheaply, e.g. using a blocked IP list.
This commit adds a new --connection-limit option to the server example
to illustrate how a user could implement a limit to the number of
connections open at a time with the new "incoming" API and
Endpoint::open_connections method rather than with the now-removed
concurrent_connections ServerConfig parameter.
This commit adds a new --block option to the server example to
illustate in a simplified way the general structure one would use to
implement IP address blocking with the new accept/reject/retry API.
For example:
cargo run --example server ./ --listen 127.0.0.1:4433 --stateless-retry --block 127.0.0.1:8065
cargo run --example client https://127.0.0.1:4433/Cargo.toml --host localhost --bind 127.0.0.1:8065
One thing to note is that that example places the reject condition
before the retry condition. This expends slightly less effort rejecting
connections, but does create a blocked IP address oracle for an attacker
who can do address spoofing.
This commit removes use_retry from the server config and provides a
public API for the user to manually accept/refuse/retry incoming
connections before a handshake begins, and inspect properties such as
an incoming connection's remote address and whether that address is
validated when doing so.
In quinn-proto, Incoming is made public, as well as Endpoint's accept/
refuse/retry methods which operate on it. The
DatagramEvent::NewConnection event is modified to return an incoming
but not yet accepted connection.
In quinn, awaiting Endpoint::accept now yields a new
quinn::Incoming type, rather than quinn::Connecting. The new
quinn::Incoming type has all the methods its quinn_proto equivalent has,
as well as an accept method to (fallibly) transition it into a
Connecting, and also refuse, retry, and ignore methods.
Furthermore, quinn::Incoming implements IntoFuture with the output type
Result<Connection, ConnectionError>>, which is the same as the Future
output type of Connecting. This lets server code which was
straightforwardly awaiting the result of quinn::Endpoint::accept work
with little to no modification.
The test accept_after_close was removed because the functionality it
was testing for no longer exists.
This commit refactors the logic for a quinn_proto::Endpoint accepting
an incoming connection so that it constructs an explicit Incoming struct
containing all the necessary state to accept/reject/retry the
connection-creating packet. However, the external API stays the same.
The bulk of this code change is just moving around existing code.
Additionally, adds some gitignore lines I was using for coverage
testing.
This commit factors out the two fields of a quinn::Endpoint's State
necessary to process a proto::Transmit into a new sub-struct,
TransmitState. This is to alleviate borrowing issues, because
proto::Transmit will soon be called from more call sites than
previously.
The bulk of this code change is just moving around existing code.
Co-authored-by: Dirkjan Ochtman <dirkjan@ochtman.nl>
Subsequent commits will allow the user to achieve the removed behavior
manually and more flexibly.
- Removes concurrent_connections from ServerConfig, as well as
corresponding check in early_validate_first_packet.
- Adds ConnectionError::CidsExhausted error, although it is not yet
instantiated.
- Renames ConnectError variant TooManyConnections to CidsExhausted.
- Renames proto Endpoint internal method is_full to cids_exhausted.
- Adds method open_connections to Endpoint (both proto and quinn).
- Removes Endpoint method reject_new_connection from Endpoint (both
proto and quinn).
- Deletes obselete tests concurrent_connections_full and
reject_new_connections.
Benjamin Saunders