Improve QUIC sniffer

common/ja3/error.go

@@ -0,0 +1,31 @@
+// Copyright (c) 2018, Open Systems AG. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package ja3
+
+import "fmt"
+
+// Error types
+const (
+	LengthErr        string = "length check %v failed"
+	ContentTypeErr   string = "content type not matching"
+	VersionErr       string = "version check %v failed"
+	HandshakeTypeErr string = "handshake type not matching"
+	SNITypeErr       string = "SNI type not supported"
+)
+
+// ParseError can be encountered while parsing a segment
+type ParseError struct {
+	errType string
+	check   int
+}
+
+func (e *ParseError) Error() string {
+	if e.errType == LengthErr || e.errType == VersionErr {
+		return fmt.Sprintf(e.errType, e.check)
+	}
+	return fmt.Sprint(e.errType)
+}