channel

Documentation

Overview

Package channel provides the implementation of channel-based data-link layer endpoints. Such endpoints allow injection of inbound packets and store outbound packets in a channel.

Index

• type Endpoint
  • func New(size int, mtu uint32, linkAddr tcpip.LinkAddress) *Endpoint
  • func (*Endpoint) ARPHardwareType() header.ARPHardwareType
  • func (*Endpoint) AddHeader(*stack.PacketBuffer)
  • func (e *Endpoint) AddNotify(notify Notification) *NotificationHandle
  • func (e *Endpoint) Attach(dispatcher stack.NetworkDispatcher)
  • func (e *Endpoint) Capabilities() stack.LinkEndpointCapabilities
  • func (e *Endpoint) Close()
  • func (e *Endpoint) Drain() int
  • func (*Endpoint) GSOMaxSize() uint32
  • func (e *Endpoint) InjectInbound(protocol tcpip.NetworkProtocolNumber, pkt *stack.PacketBuffer)
  • func (e *Endpoint) IsAttached() bool
  • func (e *Endpoint) LinkAddress() tcpip.LinkAddress
  • func (e *Endpoint) MTU() uint32
  • func (*Endpoint) MaxHeaderLength() uint16
  • func (e *Endpoint) NumQueued() int
  • func (*Endpoint) ParseHeader(*stack.PacketBuffer) bool
  • func (e *Endpoint) Read() *stack.PacketBuffer
  • func (e *Endpoint) ReadContext(ctx context.Context) *stack.PacketBuffer
  • func (e *Endpoint) RemoveNotify(handle *NotificationHandle)
  • func (e *Endpoint) SetLinkAddress(addr tcpip.LinkAddress)
  • func (e *Endpoint) SetMTU(mtu uint32)
  • func (*Endpoint) SetOnCloseAction(func())
  • func (e *Endpoint) SupportedGSO() stack.SupportedGSO
  • func (*Endpoint) Wait()
  • func (e *Endpoint) WritePackets(pkts stack.PacketBufferList) (int, tcpip.Error)
• type Notification
• type NotificationHandle

Types

type Endpoint

type Endpoint struct {
	LinkEPCapabilities stack.LinkEndpointCapabilities
	SupportedGSOKind   stack.SupportedGSO
	// contains filtered or unexported fields
}

Endpoint is link layer endpoint that stores outbound packets in a channel and allows injection of inbound packets.

+stateify savable

func New

func New(size int, mtu uint32, linkAddr tcpip.LinkAddress) *Endpoint

New creates a new channel endpoint.

func (*Endpoint) ARPHardwareType

func (*Endpoint) ARPHardwareType() header.ARPHardwareType

ARPHardwareType implements stack.LinkEndpoint.ARPHardwareType.

func (*Endpoint) AddHeader

func (*Endpoint) AddHeader(*stack.PacketBuffer)

AddHeader implements stack.LinkEndpoint.AddHeader.

func (*Endpoint) AddNotify

func (e *Endpoint) AddNotify(notify Notification) *NotificationHandle

AddNotify adds a notification target for receiving event about outgoing packets.

func (*Endpoint) Attach

func (e *Endpoint) Attach(dispatcher stack.NetworkDispatcher)

Attach saves the stack network-layer dispatcher for use later when packets are injected.

func (*Endpoint) Capabilities

func (e *Endpoint) Capabilities() stack.LinkEndpointCapabilities

Capabilities implements stack.LinkEndpoint.Capabilities.

func (*Endpoint) Close

func (e *Endpoint) Close()

Close closes e. Further packet injections will return an error, and all pending packets are discarded. Close may be called concurrently with WritePackets.

func (*Endpoint) Drain

func (e *Endpoint) Drain() int

Drain removes all outbound packets from the channel and counts them.

func (*Endpoint) GSOMaxSize

func (*Endpoint) GSOMaxSize() uint32

GSOMaxSize implements stack.GSOEndpoint.

func (*Endpoint) InjectInbound

func (e *Endpoint) InjectInbound(protocol tcpip.NetworkProtocolNumber, pkt *stack.PacketBuffer)

InjectInbound injects an inbound packet. If the endpoint is not attached, the packet is not delivered.

func (*Endpoint) IsAttached

func (e *Endpoint) IsAttached() bool

IsAttached implements stack.LinkEndpoint.IsAttached.

func (*Endpoint) LinkAddress

func (e *Endpoint) LinkAddress() tcpip.LinkAddress

LinkAddress returns the link address of this endpoint.

func (*Endpoint) MTU

func (e *Endpoint) MTU() uint32

MTU implements stack.LinkEndpoint.MTU.

func (*Endpoint) MaxHeaderLength

func (*Endpoint) MaxHeaderLength() uint16

MaxHeaderLength returns the maximum size of the link layer header. Given it doesn't have a header, it just returns 0.

func (*Endpoint) NumQueued

func (e *Endpoint) NumQueued() int

NumQueued returns the number of packet queued for outbound.

func (*Endpoint) ParseHeader

func (*Endpoint) ParseHeader(*stack.PacketBuffer) bool

ParseHeader implements stack.LinkEndpoint.ParseHeader.

func (*Endpoint) Read

func (e *Endpoint) Read() *stack.PacketBuffer

Read does non-blocking read one packet from the outbound packet queue.

func (*Endpoint) ReadContext

func (e *Endpoint) ReadContext(ctx context.Context) *stack.PacketBuffer

ReadContext does blocking read for one packet from the outbound packet queue. It can be cancelled by ctx, and in this case, it returns nil.

func (*Endpoint) RemoveNotify

func (e *Endpoint) RemoveNotify(handle *NotificationHandle)

RemoveNotify removes handle from the list of notification targets.

func (*Endpoint) SetLinkAddress

func (e *Endpoint) SetLinkAddress(addr tcpip.LinkAddress)

SetLinkAddress implements stack.LinkEndpoint.SetLinkAddress.

func (*Endpoint) SetMTU

func (e *Endpoint) SetMTU(mtu uint32)

SetMTU implements stack.LinkEndpoint.SetMTU.

func (*Endpoint) SetOnCloseAction

func (*Endpoint) SetOnCloseAction(func())

SetOnCloseAction implements stack.LinkEndpoint.

func (*Endpoint) SupportedGSO

func (e *Endpoint) SupportedGSO() stack.SupportedGSO

SupportedGSO implements stack.GSOEndpoint.

func (*Endpoint) Wait

func (*Endpoint) Wait()

Wait implements stack.LinkEndpoint.Wait.

func (*Endpoint) WritePackets

func (e *Endpoint) WritePackets(pkts stack.PacketBufferList) (int, tcpip.Error)

WritePackets stores outbound packets into the channel. Multiple concurrent calls are permitted.

type Notification

type Notification interface {
	// WriteNotify will be called when a write happens to the queue.
	WriteNotify()
}

Notification is the interface for receiving notification from the packet queue.

type NotificationHandle

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

NotificationHandle is an opaque handle to the registered notification target. It can be used to unregister the notification when no longer interested.

+stateify savable