1 files changed, 187 insertions, 0 deletions
diff --git a/pkg/tcpip/sample/wg_tunnel/fsm.go b/pkg/tcpip/sample/wg_tunnel/fsm.go
new file mode 100644
index 000000000..965f6fca9
--- /dev/null
+++ b/pkg/tcpip/sample/wg_tunnel/fsm.go
@@ -0,0 +1,187 @@
+package main
+
+import (
+	"fmt"
+//	"log"
+	"github.com/insomniacslk/dhcp/dhcpv6"
+)
+
+// FSM from RFC 2131 Figure 5
+
+type DHCP interface {
+	SendDiscover()
+	SendRequest()
+}
+
+type FSM struct {
+	state State
+	dhcp DHCP
+}
+
+type DHCPv4 struct {
+}
+
+func (f FSM) Init(d DHCP) {
+	fmt.Println("Init")
+	f.dhcp = d
+	f.state = stInit(f.dhcp, nil)
+
+	//	go 
+}
+
+func (f FSM) InputMessage() {
+}
+
+func (d DHCPv4) SendDiscover() {
+}
+
+type DHCPv6 struct {
+}
+
+func (d DHCPv6) SendDiscover() {
+	fmt.Println("SendDiscover")
+}
+
+func (d DHCPv6) SendRequest() {
+	fmt.Println("SendRequest")
+}
+
+type EventType uint8
+
+const (
+	EventTypeNone         EventType = 0
+	EventTypeMessage      EventType = 1
+	EventTypeTimeoutT1    EventType = 2
+	EventTypeTimeoutT2    EventType = 3
+	EventTypeTimeoutLease EventType = 3
+)
+
+type Event interface {
+	Type() EventType
+}
+
+// type TimerType uint8
+
+// const (
+// 	TimerNone  TimerType = 0
+// 	TimerT1    TimerType = 1
+// 	TimerT2    TimerType = 2
+// 	TimerLease TimerType = 3
+// )
+
+// type EventTimeout struct {
+// 	Event
+// 	Timer TimerType
+// }
+
+type EventMessage struct {
+	Event
+	msg dhcpv6.Message
+}
+
+func (ev *EventMessage) Type() EventType {
+	return EventTypeMessage
+}
+
+func (ev *EventMessage) Msg() dhcpv6.Message {
+	return ev.msg
+}
+
+type State func (d DHCP, ev Event) (next State)
+
+func stInit(d DHCP, ev Event) State {
+	// Send Discover
+	d.SendDiscover()
+	return stSelecting
+}
+
+func stSelecting(d DHCP, ev Event) State {
+	switch ev.Type() {
+	case EventTypeMessage:
+		msg := ev.(*EventMessage).Msg()
+		switch msg.Type() {
+		case dhcpv6.MessageTypeAdvertise:
+			// Select first offer
+			d.SendRequest()
+			return stRequesting
+		}
+	}
+	return stSelecting
+}
+
+func stRequesting(d DHCP, ev Event) State {
+	switch ev.Type() {
+	case EventTypeMessage:
+		msg := ev.(*EventMessage).Msg()
+		switch msg.Type() {
+		case dhcpv6.MessageTypeAdvertise:
+			// Discard
+			return stRequesting
+		case dhcpv6.MessageTypeReply:
+			// Record lease, set T1, T2
+			return stBound
+		case dhcpv6.MessageTypeNone: // FIXME NAK
+			// Send Decline
+			return stInit
+		}
+	}
+	return stRequesting
+}
+
+func stBound(d DHCP, ev Event) State {
+	switch ev.Type() {
+	case EventTypeTimeoutT1:
+		// Send Request
+		return stRenewing
+	case  EventTypeMessage:
+		msg := ev.(*EventMessage).Msg()
+		switch msg.Type() {
+		case dhcpv6.MessageTypeAdvertise:
+		case dhcpv6.MessageTypeReply:
+		case dhcpv6.MessageTypeNone:
+			// TODO or NACK
+			// Send Decline
+			return stBound
+		}
+	}		
+	return stBound
+}
+
+func stRenewing(d DHCP, ev Event) State {
+	// FIXME
+	switch ev.Type() {
+	case EventTypeTimeoutT2:
+		// Broadcast request?
+		return stRebinding
+	case EventTypeMessage:
+		msg := ev.(*EventMessage).Msg()
+		switch msg.Type() {
+		case dhcpv6.MessageTypeReply:
+			// Record lease, set T1, T2
+			return stBound
+		case dhcpv6.MessageTypeNone: // FIXME NAK
+			// HALT network
+			return stInit
+		}
+	}
+	return stRenewing
+}
+
+func stRebinding(d DHCP, ev Event) State {
+	switch ev.Type() {
+	case EventTypeTimeoutLease:
+		// Halt network
+		return stInit
+	case EventTypeMessage:
+		msg := ev.(*EventMessage).Msg()
+		switch msg.Type() {
+		case dhcpv6.MessageTypeReply:
+			// Record lease, set timers T1, T2
+			return stBound
+		case dhcpv6.MessageTypeNone: // FIXME NAK
+			// Halt network
+			return stInit
+		}
+	}
+	return stRebinding
+}