add support for providing a custom Connection ID generator via Config (#3452)

* Add support for providing a custom ConnectionID generator via Config

This work makes it possible for servers or clients to control how
ConnectionIDs are generated, which in turn will force peers in the
connection to use those ConnectionIDs as destination connection IDs  when sending packets.

This is useful for scenarios where we want to perform some kind
selection on the QUIC packets at the L4 level.

* add more doc

* refactor populate config to not use provided config

* add an integration test for custom connection ID generators

* fix linter warnings

Co-authored-by: Marten Seemann <martenseemann@gmail.com>
This commit is contained in:
João Oliveirinha 2022-08-24 12:06:16 +01:00 committed by GitHub
parent 034fc4e09a
commit 66f6fe0b71
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
11 changed files with 124 additions and 38 deletions

View file

@ -201,6 +201,24 @@ type EarlyConnection interface {
NextConnection() Connection
}
// A ConnectionIDGenerator is an interface that allows clients to implement their own format
// for the Connection IDs that servers/clients use as SrcConnectionID in QUIC packets.
//
// Connection IDs generated by an implementation should always produce IDs of constant size.
type ConnectionIDGenerator interface {
// GenerateConnectionID generates a new ConnectionID.
// Generated ConnectionIDs should be unique and observers should not be able to correlate two ConnectionIDs.
GenerateConnectionID() ([]byte, error)
// ConnectionIDLen tells what is the length of the ConnectionIDs generated by the implementation of
// this interface.
// Effectively, this means that implementations of ConnectionIDGenerator must always return constant-size
// connection IDs. Valid lengths are between 0 and 20 and calls to GenerateConnectionID.
// 0-length ConnectionsIDs can be used when an endpoint (server or client) does not require multiplexing connections
// in the presence of a connection migration environment.
ConnectionIDLen() int
}
// Config contains all configuration data needed for a QUIC server or client.
type Config struct {
// The QUIC versions that can be negotiated.
@ -213,6 +231,11 @@ type Config struct {
// If used for a server, or dialing on a packet conn, a 4 byte connection ID will be used.
// When dialing on a packet conn, the ConnectionIDLength value must be the same for every Dial call.
ConnectionIDLength int
// An optional ConnectionIDGenerator to be used for ConnectionIDs generated during the lifecycle of a QUIC connection.
// The goal is to give some control on how connection IDs, which can be useful in some scenarios, in particular for servers.
// By default, if not provided, random connection IDs with the length given by ConnectionIDLength is used.
// Otherwise, if one is provided, then ConnectionIDLength is ignored.
ConnectionIDGenerator ConnectionIDGenerator
// HandshakeIdleTimeout is the idle timeout before completion of the handshake.
// Specifically, if we don't receive any packet from the peer within this time, the connection attempt is aborted.
// If this value is zero, the timeout is set to 5 seconds.