From ae5a8bd35ce35470b4609caf2dedc9b00dfc7cee Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Fri, 31 Mar 2023 19:35:03 +0900
Subject: [PATCH] move the QUIC version check to the config validation

---
 client.go      | 10 ----------
 client_test.go |  5 +----
 config.go      |  7 +++++++
 server.go      |  5 -----
 server_test.go |  2 +-
 5 files changed, 9 insertions(+), 20 deletions(-)

diff --git a/client.go b/client.go
index 62cad580..ad80d4f2 100644
--- a/client.go
+++ b/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
diff --git a/client_test.go b/client_test.go
index 23122e62..dbd03cf3 100644
--- a/client_test.go
+++ b/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() {
diff --git a/config.go b/config.go
index 3ead9b7a..b513a46b 100644
--- a/config.go
+++ b/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
 }
 
diff --git a/server.go b/server.go
index 3543e546..d5bb19e6 100644
--- a/server.go
+++ b/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 {
diff --git a/server_test.go b/server_test.go
index e9f751e6..4108c698 100644
--- a/server_test.go
+++ b/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() {