TUN-4597: Add a QUIC server skeleton

- Added a QUIC server to accept streams
- Unit test for this server also tests ALPN
- Temporary echo capability for HTTP ConnectionType

vendor/github.com/lucas-clemente/quic-go/config.go

@@ -0,0 +1,122 @@
+package quic
+
+import (
+	"errors"
+	"time"
+
+	"github.com/lucas-clemente/quic-go/internal/utils"
+
+	"github.com/lucas-clemente/quic-go/internal/protocol"
+)
+
+// Clone clones a Config
+func (c *Config) Clone() *Config {
+	copy := *c
+	return &copy
+}
+
+func (c *Config) handshakeTimeout() time.Duration {
+	return utils.MaxDuration(protocol.DefaultHandshakeTimeout, 2*c.HandshakeIdleTimeout)
+}
+
+func validateConfig(config *Config) error {
+	if config == nil {
+		return nil
+	}
+	if config.MaxIncomingStreams > 1<<60 {
+		return errors.New("invalid value for Config.MaxIncomingStreams")
+	}
+	if config.MaxIncomingUniStreams > 1<<60 {
+		return errors.New("invalid value for Config.MaxIncomingUniStreams")
+	}
+	return nil
+}
+
+// populateServerConfig populates fields in the quic.Config with their default values, if none are set
+// it may be called with nil
+func populateServerConfig(config *Config) *Config {
+	config = populateConfig(config)
+	if config.ConnectionIDLength == 0 {
+		config.ConnectionIDLength = protocol.DefaultConnectionIDLength
+	}
+	if config.AcceptToken == nil {
+		config.AcceptToken = defaultAcceptToken
+	}
+	return config
+}
+
+// populateClientConfig populates fields in the quic.Config with their default values, if none are set
+// it may be called with nil
+func populateClientConfig(config *Config, createdPacketConn bool) *Config {
+	config = populateConfig(config)
+	if config.ConnectionIDLength == 0 && !createdPacketConn {
+		config.ConnectionIDLength = protocol.DefaultConnectionIDLength
+	}
+	return config
+}
+
+func populateConfig(config *Config) *Config {
+	if config == nil {
+		config = &Config{}
+	}
+	versions := config.Versions
+	if len(versions) == 0 {
+		versions = protocol.SupportedVersions
+	}
+	handshakeIdleTimeout := protocol.DefaultHandshakeIdleTimeout
+	if config.HandshakeIdleTimeout != 0 {
+		handshakeIdleTimeout = config.HandshakeIdleTimeout
+	}
+	idleTimeout := protocol.DefaultIdleTimeout
+	if config.MaxIdleTimeout != 0 {
+		idleTimeout = config.MaxIdleTimeout
+	}
+	initialStreamReceiveWindow := config.InitialStreamReceiveWindow
+	if initialStreamReceiveWindow == 0 {
+		initialStreamReceiveWindow = protocol.DefaultInitialMaxStreamData
+	}
+	maxStreamReceiveWindow := config.MaxStreamReceiveWindow
+	if maxStreamReceiveWindow == 0 {
+		maxStreamReceiveWindow = protocol.DefaultMaxReceiveStreamFlowControlWindow
+	}
+	initialConnectionReceiveWindow := config.InitialConnectionReceiveWindow
+	if initialConnectionReceiveWindow == 0 {
+		initialConnectionReceiveWindow = protocol.DefaultInitialMaxData
+	}
+	maxConnectionReceiveWindow := config.MaxConnectionReceiveWindow
+	if maxConnectionReceiveWindow == 0 {
+		maxConnectionReceiveWindow = protocol.DefaultMaxReceiveConnectionFlowControlWindow
+	}
+	maxIncomingStreams := config.MaxIncomingStreams
+	if maxIncomingStreams == 0 {
+		maxIncomingStreams = protocol.DefaultMaxIncomingStreams
+	} else if maxIncomingStreams < 0 {
+		maxIncomingStreams = 0
+	}
+	maxIncomingUniStreams := config.MaxIncomingUniStreams
+	if maxIncomingUniStreams == 0 {
+		maxIncomingUniStreams = protocol.DefaultMaxIncomingUniStreams
+	} else if maxIncomingUniStreams < 0 {
+		maxIncomingUniStreams = 0
+	}
+
+	return &Config{
+		Versions:                       versions,
+		HandshakeIdleTimeout:           handshakeIdleTimeout,
+		MaxIdleTimeout:                 idleTimeout,
+		AcceptToken:                    config.AcceptToken,
+		KeepAlive:                      config.KeepAlive,
+		InitialStreamReceiveWindow:     initialStreamReceiveWindow,
+		MaxStreamReceiveWindow:         maxStreamReceiveWindow,
+		InitialConnectionReceiveWindow: initialConnectionReceiveWindow,
+		MaxConnectionReceiveWindow:     maxConnectionReceiveWindow,
+		MaxIncomingStreams:             maxIncomingStreams,
+		MaxIncomingUniStreams:          maxIncomingUniStreams,
+		ConnectionIDLength:             config.ConnectionIDLength,
+		StatelessResetKey:              config.StatelessResetKey,
+		TokenStore:                     config.TokenStore,
+		EnableDatagrams:                config.EnableDatagrams,
+		DisablePathMTUDiscovery:        config.DisablePathMTUDiscovery,
+		Tracer:                         config.Tracer,
+	}
+}