metadata

Documentation

Overview

Package metadata implements the metadata packet header.

Index

• type Metadata
  • func (m *Metadata) Field(id fwdpacket.FieldID) ([]byte, error)
  • func (Metadata) Header() []byte
  • func (Metadata) ID(int) fwdpb.PacketHeaderId
  • func (Metadata) Modify(fwdpb.PacketHeaderId) error
  • func (m *Metadata) Rebuild() error
  • func (Metadata) Remove(fwdpb.PacketHeaderId) error
  • func (Metadata) Trailer() []byte
  • func (m *Metadata) UpdateField(id fwdpacket.FieldID, op int, arg []byte) (bool, error)

Types

type Metadata

type Metadata struct {
	// contains filtered or unexported fields
}

Metadata is a manadatory packet header that stores derived state of a packet. Since metadata is not a real packet header, it does not contribute to the packet's frame.

func (*Metadata) Field

func (m *Metadata) Field(id fwdpacket.FieldID) ([]byte, error)

Field returns the values of the queried packet fields.

func (Metadata) Header

func (Metadata) Header() []byte

Header returns nil as it does not contribute to the packet's frame.

func (Metadata) ID

func (Metadata) ID(int) fwdpb.PacketHeaderId

ID returns the protocol header ID.

func (Metadata) Modify

func (Metadata) Modify(fwdpb.PacketHeaderId) error

Modify returns an error as the metadata header cannot be changed.

func (*Metadata) Rebuild

func (m *Metadata) Rebuild() error

Rebuild updates the packet length. The length is zero if the packet had zero bytes.

func (Metadata) Remove

func (Metadata) Remove(fwdpb.PacketHeaderId) error

Remove returns an error as the metadata header cannot be removed.

func (Metadata) Trailer

func (Metadata) Trailer() []byte

Trailer returns the no trailing bytes.

func (*Metadata) UpdateField

func (m *Metadata) UpdateField(id fwdpacket.FieldID, op int, arg []byte) (bool, error)

UpdateField can update the input and output port of the packet.