添加 github.com/pion/dtls 代码

dtls-2.0.9/pkg/protocol/content.go

@@ -0,0 +1,21 @@
+package protocol
+
+// ContentType represents the IANA Registered ContentTypes
+//
+// https://tools.ietf.org/html/rfc4346#section-6.2.1
+type ContentType uint8
+
+// ContentType enums
+const (
+	ContentTypeChangeCipherSpec ContentType = 20
+	ContentTypeAlert            ContentType = 21
+	ContentTypeHandshake        ContentType = 22
+	ContentTypeApplicationData  ContentType = 23
+)
+
+// Content is the top level distinguisher for a DTLS Datagram
+type Content interface {
+	ContentType() ContentType
+	Marshal() ([]byte, error)
+	Unmarshal(data []byte) error
+}