From e18614bfec1721c4a792598d19f2dcd3b024fc65 Mon Sep 17 00:00:00 2001
From: Josh Deprez <josh.deprez@gmail.com>
Date: Sun, 17 Mar 2024 13:35:50 +1100
Subject: [PATCH] RD

---
 aurp/aurp.go        |  8 ++++++++
 aurp/router_down.go | 29 +++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)
 create mode 100644 aurp/router_down.go

diff --git a/aurp/aurp.go b/aurp/aurp.go
index a09206b..3ecca05 100644
--- a/aurp/aurp.go
+++ b/aurp/aurp.go
@@ -210,6 +210,14 @@ func ParsePacket(p []byte) (Packet, error) {
 			riu.Header = h
 			return riu, nil
 
+		case CmdCodeRD:
+			rd, err := parseRD(p)
+			if err != nil {
+				return nil, err
+			}
+			rd.Header = h
+			return rd, nil
+
 		default:
 			return nil, fmt.Errorf("unknown routing packet command code %d", h.CommandCode)
 		}
diff --git a/aurp/router_down.go b/aurp/router_down.go
new file mode 100644
index 0000000..6cf5fd2
--- /dev/null
+++ b/aurp/router_down.go
@@ -0,0 +1,29 @@
+package aurp
+
+import (
+	"encoding/binary"
+	"fmt"
+	"io"
+)
+
+type RDPacket struct {
+	Header
+
+	ErrorCode int16
+}
+
+func (p *RDPacket) WriteTo(w io.Writer) (int64, error) {
+	a := acc(w)
+	a.writeTo(&p.Header)
+	a.write16(uint16(p.ErrorCode))
+	return a.ret()
+}
+
+func parseRD(p []byte) (*RDPacket, error) {
+	if len(p) < 2 {
+		return nil, fmt.Errorf("insufficient input length %d for router down packet", len(p))
+	}
+	return &RDPacket{
+		ErrorCode: int16(binary.BigEndian.Uint16(p[:2])),
+	}, nil
+}