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

go-agentx/pdu/object_identifier.go

@@ -0,0 +1,96 @@
+// Copyright 2018 The agentx authors
+// Licensed under the LGPLv3 with static-linking exception.
+// See LICENCE file for details.
+
+package pdu
+
+import (
+	"bytes"
+	"encoding/binary"
+
+	"github.com/posteo/go-agentx/value"
+)
+
+// ObjectIdentifier defines the pdu object identifier packet.
+type ObjectIdentifier struct {
+	Prefix         uint8
+	Include        byte
+	Subidentifiers []uint32
+}
+
+// SetInclude sets the include field.
+func (o *ObjectIdentifier) SetInclude(value bool) {
+	if value {
+		o.Include = 0x01
+	} else {
+		o.Include = 0x00
+	}
+}
+
+// GetInclude returns true if the include field ist set, false otherwise.
+func (o *ObjectIdentifier) GetInclude() bool {
+	if o.Include == 0x00 {
+		return false
+	}
+	return true
+}
+
+// SetIdentifier set the subidentifiers by the provided oid string.
+func (o *ObjectIdentifier) SetIdentifier(oid value.OID) {
+	o.Subidentifiers = make([]uint32, 0)
+
+	if len(oid) > 4 && oid[0] == 1 && oid[1] == 3 && oid[2] == 6 && oid[3] == 1 {
+		o.Subidentifiers = append(o.Subidentifiers, uint32(1), uint32(3), uint32(6), uint32(1), uint32(oid[4]))
+		oid = oid[5:]
+	}
+
+	o.Subidentifiers = append(o.Subidentifiers, oid...)
+}
+
+// GetIdentifier returns the identifier as an oid string.
+func (o *ObjectIdentifier) GetIdentifier() value.OID {
+	var oid value.OID
+	if o.Prefix != 0 {
+		oid = append(oid, 1, 3, 6, 1, uint32(o.Prefix))
+	}
+	return append(oid, o.Subidentifiers...)
+}
+
+// ByteSize returns the number of bytes, the binding would need in the encoded version.
+func (o *ObjectIdentifier) ByteSize() int {
+	return 4 + len(o.Subidentifiers)*4
+}
+
+// MarshalBinary returns the pdu packet as a slice of bytes.
+func (o *ObjectIdentifier) MarshalBinary() ([]byte, error) {
+	buffer := bytes.NewBuffer([]byte{byte(len(o.Subidentifiers)), o.Prefix, o.Include, 0x00})
+
+	for _, subidentifier := range o.Subidentifiers {
+		binary.Write(buffer, binary.LittleEndian, &subidentifier)
+	}
+
+	return buffer.Bytes(), nil
+}
+
+// UnmarshalBinary sets the packet structure from the provided slice of bytes.
+func (o *ObjectIdentifier) UnmarshalBinary(data []byte) error {
+	count := data[0]
+	o.Prefix = data[1]
+	o.Include = data[2]
+
+	o.Subidentifiers = make([]uint32, 0)
+	buffer := bytes.NewBuffer(data[4:])
+	for index := byte(0); index < count; index++ {
+		var subidentifier uint32
+		if err := binary.Read(buffer, binary.LittleEndian, &subidentifier); err != nil {
+			return err
+		}
+		o.Subidentifiers = append(o.Subidentifiers, subidentifier)
+	}
+
+	return nil
+}
+
+func (o ObjectIdentifier) String() string {
+	return o.GetIdentifier().String()
+}