Crate kvarn_quinn

QUIC transport protocol implementation

QUIC is a modern transport protocol addressing shortcomings of TCP, such as head-of-line blocking, poor security, slow handshakes, and inefficient congestion control. This crate provides a portable userspace implementation. It builds on top of quinn-proto, which implements protocol logic independent of any particular runtime.

The entry point of this crate is the Endpoint.

About QUIC

A QUIC connection is an association between two endpoints. The endpoint which initiates the connection is termed the client, and the endpoint which accepts it is termed the server. A single endpoint may function as both client and server for different connections, for example in a peer-to-peer application. To communicate application data, each endpoint may open streams up to a limit dictated by its peer. Typically, that limit is increased as old streams are finished.

Streams may be unidirectional or bidirectional, and are cheap to create and disposable. For example, a traditionally datagram-oriented application could use a new stream for every message it wants to send, no longer needing to worry about MTUs. Bidirectional streams behave much like a traditional TCP connection, and are useful for sending messages that have an immediate response, such as an HTTP request. Stream data is delivered reliably, and there is no ordering enforced between data on different streams.

By avoiding head-of-line blocking and providing unified congestion control across all streams of a connection, QUIC is able to provide higher throughput and lower latency than one or multiple TCP connections between the same two hosts, while providing more useful behavior than raw UDP sockets.

Quinn also exposes unreliable datagrams, which are a low-level primitive preferred when automatic fragmentation and retransmission of certain data is not desired.

QUIC uses encryption and identity verification built directly on TLS 1.3. Just as with a TLS server, it is useful for a QUIC server to be identified by a certificate signed by a trusted authority. If this is infeasible–for example, if servers are short-lived or not associated with a domain name–then as with TLS, self-signed certificates can be used to provide encryption alone.

Re-exports

pub use rustls;

pub use udp;

Modules

congestion

Logic for controlling the rate at which data is sent

crypto

Traits and implementations for the QUIC cryptography protocol

Structs

Accept

Future produced by Endpoint::accept

AcceptBi

Future produced by Connection::accept_bi

AcceptUni

Future produced by Connection::accept_uni

AckFrequencyConfig

Parameters for controlling the peer’s acknowledgement frequency

ApplicationClose

Reason given by an application for closing the connection

AsyncStdRuntime

A Quinn runtime for async-std

Chunk

A chunk of data from the receive stream

ClientConfig

Configuration for outgoing connections

Connecting

In-progress connection attempt future

Connection

A QUIC connection.

ConnectionClose

Reason given by the transport for closing the connection

Endpoint

A QUIC endpoint.

EndpointConfig

Global configuration for the endpoint, affecting all connections

IdleTimeout

Maximum duration of inactivity to accept before timing out the connection.

MtuDiscoveryConfig

Parameters governing MTU discovery.

OpenBi

Future produced by Connection::open_bi

OpenUni

Future produced by Connection::open_uni

ReadDatagram

Future produced by Connection::read_datagram

RecvStream

A stream that can only be used to receive data

SendStream

A stream that can only be used to send data

ServerConfig

Parameters governing incoming connections

SmolRuntime

A Quinn runtime for smol

StreamId

Identifier for a stream within a particular connection

TokioRuntime

A Quinn runtime for Tokio

Transmit

An outgoing packet

TransportConfig

Parameters governing the core QUIC state machine

UnknownStream

Error indicating that a stream has already been finished or reset

VarInt

An integer less than 2^62

ZeroRttAccepted

Future that completes when a connection is fully established

Enums

ConfigError

Errors in the configuration of an endpoint

ConnectError

Errors in the parameters being used to create a new connection

ConnectionError

Reasons why a connection might be lost

ReadError

Errors that arise from reading from a stream.

ReadExactError

Errors that arise from reading from a stream.

ReadToEndError

Errors from RecvStream::read_to_end

SendDatagramError

Errors that can arise when sending a datagram

StoppedError

Errors that arise while monitoring for a send stream stop from the peer

WriteError

Errors that arise from writing to a stream

Traits

AsyncTimer

Abstract implementation of an async timer for runtime independence

AsyncUdpSocket

Abstract implementation of a UDP socket for runtime independence

Runtime

Abstracts I/O and timer operations for runtime independence

Functions

default_runtime

Automatically select an appropriate runtime from those enabled at compile time