move the QUIC version check to the config validation

client.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"crypto/tls"
 	"errors"
-	"fmt"
 	"net"
 
 	"github.com/quic-go/quic-go/internal/protocol"
@@ -136,15 +135,6 @@ func newClient(pconn net.PacketConn, remoteAddr net.Addr, config *Config, tlsCon
 		tlsConf = tlsConf.Clone()
 	}
 
-	// check that all versions are actually supported
-	if config != nil {
-		for _, v := range config.Versions {
-			if !protocol.IsValidVersion(v) {
-				return nil, fmt.Errorf("%s is not a valid QUIC version", v)
-			}
-		}
-	}
-
 	srcConnID, err := config.ConnectionIDGenerator.GenerateConnectionID()
 	if err != nil {
 		return nil, err

client_test.go

@@ -366,12 +366,9 @@ var _ = Describe("Client", func() {
 			})
 
 			It("errors when the Config contains an invalid version", func() {
-				manager := NewMockPacketHandlerManager(mockCtrl)
-				mockMultiplexer.EXPECT().AddConn(packetConn, gomock.Any(), gomock.Any(), gomock.Any()).Return(manager, nil)
-
 				version := protocol.VersionNumber(0x1234)
 				_, err := Dial(context.Background(), packetConn, nil, tlsConf, &Config{Versions: []protocol.VersionNumber{version}})
-				Expect(err).To(MatchError("0x1234 is not a valid QUIC version"))
+				Expect(err).To(MatchError("invalid QUIC version: 0x1234"))
 			})
 
 			It("disables bidirectional streams", func() {

config.go

@@ -2,6 +2,7 @@ package quic
 
 import (
 	"errors"
+	"fmt"
 	"net"
 	"time"
 
@@ -29,6 +30,12 @@ func validateConfig(config *Config) error {
 	if config.MaxIncomingUniStreams > 1<<60 {
 		return errors.New("invalid value for Config.MaxIncomingUniStreams")
 	}
+	// check that all QUIC versions are actually supported
+	for _, v := range config.Versions {
+		if !protocol.IsValidVersion(v) {
+			return fmt.Errorf("invalid QUIC version: %s", v)
+		}
+	}
 	return nil
 }
 

server.go

@@ -234,11 +234,6 @@ func listen(conn net.PacketConn, tlsConf *tls.Config, config *Config, acceptEarl
 		return nil, err
 	}
 	config = populateServerConfig(config)
-	for _, v := range config.Versions {
-		if !protocol.IsValidVersion(v) {
-			return nil, fmt.Errorf("%s is not a valid QUIC version", v)
-		}
-	}
 
 	connHandler, err := getMultiplexer().AddConn(conn, config.ConnectionIDGenerator.ConnectionIDLen(), config.StatelessResetKey, config.Tracer)
 	if err != nil {

server_test.go

@@ -114,7 +114,7 @@ var _ = Describe("Server", func() {
 	It("errors when the Config contains an invalid version", func() {
 		version := protocol.VersionNumber(0x1234)
 		_, err := Listen(nil, tlsConf, &Config{Versions: []protocol.VersionNumber{version}})
-		Expect(err).To(MatchError("0x1234 is not a valid QUIC version"))
+		Expect(err).To(MatchError("invalid QUIC version: 0x1234"))
 	})
 
 	It("fills in default values if options are not set in the Config", func() {