RI-Upd

aurp/aurp.go

@@ -424,6 +424,93 @@ type RIAckPacket struct {
 	*Header
 }
 
+type RIUpdPacket struct {
+	*Header
+
+	Events Events
+}
+
+func (p *RIUpdPacket) WriteTo(w io.Writer) (int64, error) {
+	a := acc(w)
+	a.writeTo(p.Header)
+	a.writeTo(p.Events)
+	return a.ret()
+}
+
+func parseRIUpd(p []byte) (*RIUpdPacket, error) {
+	var e Events
+	for len(p) > 0 {
+		et, nextp, err := parseEventTuple(p)
+		if err != nil {
+			return nil, fmt.Errorf("parsing event tuple %d: %w", len(e), err)
+		}
+		e = append(e, et)
+		p = nextp
+	}
+	return &RIUpdPacket{
+		Events: e,
+	}, nil
+}
+
+type Events []EventTuple
+
+func (e Events) WriteTo(w io.Writer) (int64, error) {
+	a := acc(w)
+	for _, et := range e {
+		a.writeTo(&et)
+	}
+	return a.ret()
+}
+
+type EventTuple struct {
+	EventCode  EventCode
+	RangeStart uint16 // or simply the network number
+	Distance   uint8
+	RangeEnd   uint16
+}
+
+func (et *EventTuple) WriteTo(w io.Writer) (int64, error) {
+	a := acc(w)
+	a.write8(uint8(et.EventCode))
+	a.write16(et.RangeStart)
+	a.write8(et.Distance)
+	if et.Distance&0x80 != 0 { // extended tuple
+		a.write16(et.RangeEnd)
+	}
+	return a.ret()
+}
+
+func parseEventTuple(p []byte) (EventTuple, []byte, error) {
+	if len(p) < 4 {
+		return EventTuple{}, p, fmt.Errorf("insufficient input length %d for network event tuple", len(p))
+	}
+
+	var et EventTuple
+	et.EventCode = EventCode(p[0])
+	et.RangeStart = binary.BigEndian.Uint16(p[1:3])
+	et.Distance = p[3]
+	if et.Distance&0x80 == 0 {
+		return et, p[4:], nil
+	}
+
+	if len(p) < 6 {
+		return EventTuple{}, p, fmt.Errorf("insufficient input length %d for extended network event tuple", len(p))
+	}
+	et.RangeEnd = binary.BigEndian.Uint16(p[4:6])
+	return et, p[6:], nil
+}
+
+type EventCode uint8
+
+const (
+	EventCodeNull EventCode = 0
+	EventCodeNA   EventCode = 1
+	EventCodeND   EventCode = 2
+	EventCodeNRC  EventCode = 3
+	EventCodeNDC  EventCode = 4
+	EventCodeZC   EventCode = 5
+)
+
 // ParsePacket parses the body of a UDP packet for a domain header, and then
 // based on the packet type, an AURP-Tr header, an AURP routing header, and
 // then a particular packet type.
@@ -489,6 +576,14 @@ func ParsePacket(p []byte) (Packet, error) {
 				Header: h,
 			}, nil
 
+		case CmdCodeRIUpd:
+			riu, err := parseRIUpd(p)
+			if err != nil {
+				return nil, err
+			}
+			riu.Header = h
+			return riu, nil
+
 		default:
 			return nil, fmt.Errorf("unknown routing packet command code %d", h.CommandCode)
 		}