cli: error classification refactoring (#386)

* make errorx classifier less dependent on strings

* adapt errorx tests

* added syserror comment

* localized classification of quic errors

* localized classification of resolver errors

* (fix) move "no such host" error to global classifier

* moved x509 errors to local TLS error classifier

* added qtls error classification for quicdialer

* add Classifier to SafeErrWrapperBuilder

* windows/unix specific files for errno constants

* added errno ETIMEDOUT, tests

* added TLS alert constants

* added FailureSSLHandshake test, improved switch style

* added more network based system error constants for future use

* (fix) import style

* (fix) errorx typos/style

* (fix) robustness of SafeErrWrapperBuilder, added comments

* (fix) reversed unnecessary changes, added comments

* (fix) style and updated comment

* errorx: added future re-structuring comment

* (fix) typo TLS alert code 51

* added comment

* alert mapping: added comment

* Update errorx.go

* Update internal/engine/netx/errorx/errorx.go

Co-authored-by: Simone Basso <bassosimone@gmail.com>

internal/engine/netx/quicdialer/errorwrapper.go

@@ -23,9 +23,10 @@ func (d ErrorWrapperDialer) DialContext(
 	err = errorx.SafeErrWrapperBuilder{
 		// ConnID does not make any sense if we've failed and the error
 		// does not make any sense (and is nil) if we succeeded.
-		DialID:    dialID,
-		Error:     err,
-		Operation: errorx.QUICHandshakeOperation,
+		Classifier: errorx.ClassifyQUICFailure,
+		DialID:     dialID,
+		Error:      err,
+		Operation:  errorx.QUICHandshakeOperation,
 	}.MaybeBuild()
 	if err != nil {
 		return nil, err

internal/engine/netx/quicdialer/errorwrapper_test.go

@@ -44,6 +44,29 @@ func errorWrapperCheckErr(t *testing.T, err error, op string) {
 	}
 }
 
+func TestErrorWrapperInvalidCertificate(t *testing.T) {
+	nextprotos := []string{"h3"}
+	servername := "example.com"
+	tlsConf := &tls.Config{
+		NextProtos: nextprotos,
+		ServerName: servername,
+	}
+
+	dlr := quicdialer.ErrorWrapperDialer{Dialer: &quicdialer.SystemDialer{}}
+	// use Google IP
+	sess, err := dlr.DialContext(context.Background(), "udp",
+		"216.58.212.164:443", tlsConf, &quic.Config{})
+	if err == nil {
+		t.Fatal("expected an error here")
+	}
+	if sess != nil {
+		t.Fatal("expected nil sess here")
+	}
+	if err.Error() != errorx.FailureSSLInvalidCertificate {
+		t.Fatal("unexpected failure")
+	}
+}
+
 func TestErrorWrapperSuccess(t *testing.T) {
 	ctx := dialid.WithDialID(context.Background())
 	tlsConf := &tls.Config{

internal/engine/netx/quicdialer/saver_test.go

@@ -85,7 +85,7 @@ func TestHandshakeSaverSuccess(t *testing.T) {
 
 func TestHandshakeSaverHostNameError(t *testing.T) {
 	nextprotos := []string{"h3"}
-	servername := "wrong.host.badssl.com"
+	servername := "example.com"
 	tlsConf := &tls.Config{
 		NextProtos: nextprotos,
 		ServerName: servername,