Temporarily add go-agentx (w/ fixes to lexico ordering)

go-agentx/pdu/octet_string.go

@@ -0,0 +1,43 @@
+// Copyright 2018 The agentx authors
+// Licensed under the LGPLv3 with static-linking exception.
+// See LICENCE file for details.
+
+package pdu
+
+import (
+	"bytes"
+	"encoding/binary"
+)
+
+// OctetString defines the pdu description packet.
+type OctetString struct {
+	Text string
+}
+
+// MarshalBinary returns the pdu packet as a slice of bytes.
+func (o *OctetString) MarshalBinary() ([]byte, error) {
+	buffer := &bytes.Buffer{}
+
+	binary.Write(buffer, binary.LittleEndian, uint32(len(o.Text)))
+	buffer.WriteString(o.Text)
+
+	for buffer.Len()%4 > 0 {
+		buffer.WriteByte(0x00)
+	}
+
+	return buffer.Bytes(), nil
+}
+
+// UnmarshalBinary sets the packet structure from the provided slice of bytes.
+func (o *OctetString) UnmarshalBinary(data []byte) error {
+	buffer := bytes.NewBuffer(data)
+
+	length := uint32(0)
+	if err := binary.Read(buffer, binary.LittleEndian, &length); err != nil {
+		return err
+	}
+
+	o.Text = string(data[4 : 4+length])
+
+	return nil
+}