udp

Documentation

Overview

Package udp contains the implementation of the UDP transport protocol.

Index

• Constants
• func NewProtocol(s *stack.Stack) stack.TransportProtocol
• type Forwarder
  • func NewForwarder(s *stack.Stack, handler func(*ForwarderRequest)) *Forwarder
  • func (f *Forwarder) HandlePacket(id stack.TransportEndpointID, pkt *stack.PacketBuffer) bool
• type ForwarderRequest
  • func (r *ForwarderRequest) CreateEndpoint(queue *waiter.Queue) (tcpip.Endpoint, tcpip.Error)
  • func (r *ForwarderRequest) ID() stack.TransportEndpointID

Constants

const (
	// ProtocolNumber is the udp protocol number.
	ProtocolNumber = header.UDPProtocolNumber

	// MinBufferSize is the smallest size of a receive or send buffer.
	MinBufferSize = 4 << 10 // 4KiB bytes.

	// DefaultSendBufferSize is the default size of the send buffer for
	// an endpoint.
	DefaultSendBufferSize = 32 << 10 // 32KiB

	// DefaultReceiveBufferSize is the default size of the receive buffer
	// for an endpoint.
	DefaultReceiveBufferSize = 32 << 10 // 32KiB

	// MaxBufferSize is the largest size a receive/send buffer can grow to.
	MaxBufferSize = 4 << 20 // 4MiB
)

Functions

func NewProtocol

func NewProtocol(s *stack.Stack) stack.TransportProtocol

NewProtocol returns a UDP transport protocol.

Types

type Forwarder

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

Forwarder is a session request forwarder, which allows clients to decide what to do with a session request, for example: ignore it, or process it.

The canonical way of using it is to pass the Forwarder.HandlePacket function to stack.SetTransportProtocolHandler.

func NewForwarder

func NewForwarder(s *stack.Stack, handler func(*ForwarderRequest)) *Forwarder

NewForwarder allocates and initializes a new forwarder.

func (*Forwarder) HandlePacket

func (f *Forwarder) HandlePacket(id stack.TransportEndpointID, pkt *stack.PacketBuffer) bool

HandlePacket handles all packets.

This function is expected to be passed as an argument to the stack.SetTransportProtocolHandler function.

type ForwarderRequest

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

ForwarderRequest represents a session request received by the forwarder and passed to the client. Clients may optionally create an endpoint to represent it via CreateEndpoint.

func (*ForwarderRequest) CreateEndpoint

func (r *ForwarderRequest) CreateEndpoint(queue *waiter.Queue) (tcpip.Endpoint, tcpip.Error)

CreateEndpoint creates a connected UDP endpoint for the session request.

func (*ForwarderRequest) ID

func (r *ForwarderRequest) ID() stack.TransportEndpointID

ID returns the 4-tuple (src address, src port, dst address, dst port) that represents the session request.