Method decodeAttribute

decoder.go:300–343

Decode a single attribute Wire format: 1 byte: Tag 2+N bytes: Name length (2 bytes) + name string 2+N bytes: Value length (2 bytes) + value bytes For the extended tag format, Tag is encoded as TagExtension and 4 bytes of the actual tag value prepended to the value bytes

(tag Tag)

// For the extended tag format, Tag is encoded as TagExtension and
// 4 bytes of the actual tag value prepended to the value bytes
func (md *messageDecoder) decodeAttribute(tag Tag) (Attribute, error) {
	var attr Attribute
	var value []byte
	var err error

	// Obtain attribute name and raw value
	attr.Name, err = md.decodeString()
	if err != nil {
		goto ERROR
	}

	value, err = md.decodeBytes()
	if err != nil {
		goto ERROR
	}

	// Handle TagExtension
	if tag == TagExtension {
		if len(value) < 4 {
			err = errors.New("Extension tag truncated")
			goto ERROR
		}

		t := binary.BigEndian.Uint32(value[:4])

		if t > 0x7fffffff {
			err = fmt.Errorf(
				"Extension tag 0x%8.8x out of range", t)
			goto ERROR
		}
	}

	// Unpack value
	err = attr.unpack(tag, value)
	if err != nil {
		goto ERROR
	}

	return attr, nil

	// Return a error
ERROR:
	return Attribute{}, err
}

// Decode a 8-bit integer
func (md *messageDecoder) decodeU8() (uint8, error) {