Docs: class diagram

README.md

@@ -1,5 +1,60 @@
-ethernet [![Build Status](https://travis-ci.org/caser789/ethernet.svg?branch=master)](https://travis-ci.org/caser789/ethernet) 
-[![GoDoc](https://godoc.org/github.com/caser789/ethernet?status.svg)](https://godoc.org/github.com/caser789/ethernet) 
+ethernet [![Build Status](https://travis-ci.org/caser789/ethernet.svg?branch=master)](https://travis-ci.org/caser789/ethernet)
+[![GoDoc](https://godoc.org/github.com/caser789/ethernet?status.svg)](https://godoc.org/github.com/caser789/ethernet)
 [![Go Report Card](https://goreportcard.com/badge/github.com/caser789/ethernet)](https://goreportcard.com/report/github.com/caser789/ethernet)
 [![Coverage Status](https://coveralls.io/repos/caser789/ethernet/badge.svg?branch=master)](https://coveralls.io/r/caser789/ethernet?branch=master)
 =====
+
+![uml class diagram](./ethernet.png)
+
+```
+@startuml
+
+title ethernet
+
+class Frame {
+    +Destination net.HardwareAddr
+    +Source net.HardwareAddr
+    +VLAN   []*VLAN
+    +EtherType EtherType
+    +Payload []byte
+    +MarshalBinary() []byte
+    +UnmarshalBinary([]byte)
+    +MarshalFCS() []byte
+    +UnmarshalFCS([]byte)
+    -read([]byte)
+    -length()
+}
+
+enum EtherType {
+    IPv4
+    ARP
+    IPv6
+    VLAN
+}
+
+enum Priority {
+	Background
+	BestEffort
+	ExcellentEffort
+    CriticalApplications
+	Video
+	Voice
+	InternetworkControl
+	NetworkControl
+}
+
+interface net.HardwareAddr {}
+
+class VLAN {
+    +Priority
+    +DropEligible
+    +ID
+    +MarshalBinary() []byte
+    -read([]byte)
+    +UnmarshalBinary([]byte)
+}
+
+Frame *-- VLAN
+
+@enduml
+```