Crate quinn

QUIC transport protocol support for Tokio

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.

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
• 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.
• 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
• 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