Add context and dialer hook to server handshake

common.go

@@ -515,6 +515,8 @@ const (
 // modified. A Config may be reused; the tls package will also not
 // modify it.
 type Config struct {
+	DialContext func(ctx context.Context, network, address string) (net.Conn, error)
+
 	Show bool
 	Type string
 	Dest string

tls.go

@@ -115,13 +115,13 @@ func Value(vals ...byte) (value int) {
 // using conn as the underlying transport.
 // The configuration config must be non-nil and must include
 // at least one certificate or else set GetCertificate.
-func Server(conn net.Conn, config *Config) (*Conn, error) {
+func Server(ctx context.Context, conn net.Conn, config *Config) (*Conn, error) {
 	remoteAddr := conn.RemoteAddr().String()
 	if config.Show {
 		fmt.Printf("REALITY remoteAddr: %v\n", remoteAddr)
 	}
 
-	target, err := net.Dial(config.Type, config.Dest)
+	target, err := config.DialContext(ctx, config.Type, config.Dest)
 	if err != nil {
 		conn.Close()
 		return nil, errors.New("REALITY: failed to dial dest: " + err.Error())
@@ -140,7 +140,7 @@ func Server(conn net.Conn, config *Config) (*Conn, error) {
 		underlying = pc.Raw()
 	}
 
-	hs := serverHandshakeStateTLS13{ctx: context.TODO()}
+	hs := serverHandshakeStateTLS13{ctx: context.Background()}
 
 	c2sSaved := make([]byte, 0, size)
 	s2cSaved := make([]byte, 0, size)
@@ -201,7 +201,7 @@ func Server(conn net.Conn, config *Config) (*Conn, error) {
 				conn:   readerConn,
 				config: config,
 			}
-			hs.clientHello, err = hs.c.readClientHello(context.TODO())
+			hs.clientHello, err = hs.c.readClientHello(context.Background())
 			if err != nil || readerConn.Reader.Len() > 0 || readerConn.Written > 0 || readerConn.Closed {
 				break
 			}
@@ -421,7 +421,7 @@ func (l *listener) Accept() (net.Conn, error) {
 	if err != nil {
 		return nil, err
 	}
-	return Server(c, l.config)
+	return Server(context.Background(), c, l.config)
 }
 
 // NewListener creates a Listener which accepts connections from an inner