channel

Documentation

Overview

Package channel provides the implemention 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(tcpip.LinkAddress, tcpip.LinkAddress, tcpip.NetworkProtocolNumber, ...)
  • 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) InjectLinkAddr(protocol tcpip.NetworkProtocolNumber, remote tcpip.LinkAddress, ...)
  • 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 (e *Endpoint) Read() (PacketInfo, bool)
  • func (e *Endpoint) ReadContext(ctx context.Context) (PacketInfo, bool)
  • func (e *Endpoint) RemoveNotify(handle *NotificationHandle)
  • func (e *Endpoint) SupportedGSO() stack.SupportedGSO
  • func (*Endpoint) Wait()
  • func (e *Endpoint) WritePacket(r stack.RouteInfo, protocol tcpip.NetworkProtocolNumber, ...) tcpip.Error
  • func (e *Endpoint) WritePackets(r stack.RouteInfo, pkts stack.PacketBufferList, ...) (int, tcpip.Error)
  • func (e *Endpoint) WriteRawPacket(pkt *stack.PacketBuffer) tcpip.Error
• type Notification
• type NotificationHandle
  • func (n *NotificationHandle) StateFields() []string
  • func (n *NotificationHandle) StateLoad(stateSourceObject state.Source)
  • func (n *NotificationHandle) StateSave(stateSinkObject state.Sink)
  • func (n *NotificationHandle) StateTypeName() string
• type PacketInfo

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.

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(tcpip.LinkAddress, tcpip.LinkAddress, tcpip.NetworkProtocolNumber, *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 panic. Reads continue to succeed until all packets are read.

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.

func (*Endpoint) InjectLinkAddr

func (e *Endpoint) InjectLinkAddr(protocol tcpip.NetworkProtocolNumber, remote tcpip.LinkAddress, pkt *stack.PacketBuffer)

InjectLinkAddr injects an inbound packet with a remote link address.

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. It returns the value initialized during construction.

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) Read

func (e *Endpoint) Read() (PacketInfo, bool)

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

func (*Endpoint) ReadContext

func (e *Endpoint) ReadContext(ctx context.Context) (PacketInfo, bool)

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

func (*Endpoint) RemoveNotify

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

RemoveNotify removes handle from the list of notification targets.

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) WritePacket

func (e *Endpoint) WritePacket(r stack.RouteInfo, protocol tcpip.NetworkProtocolNumber, pkt *stack.PacketBuffer) tcpip.Error

WritePacket stores outbound packets into the channel.

func (*Endpoint) WritePackets

func (e *Endpoint) WritePackets(r stack.RouteInfo, pkts stack.PacketBufferList, protocol tcpip.NetworkProtocolNumber) (int, tcpip.Error)

WritePackets stores outbound packets into the channel.

func (*Endpoint) WriteRawPacket

func (e *Endpoint) WriteRawPacket(pkt *stack.PacketBuffer) tcpip.Error

WriteRawPacket implements stack.LinkEndpoint.

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

func (*NotificationHandle) StateFields

func (n *NotificationHandle) StateFields() []string

func (*NotificationHandle) StateLoad

func (n *NotificationHandle) StateLoad(stateSourceObject state.Source)

+checklocksignore

func (*NotificationHandle) StateSave

func (n *NotificationHandle) StateSave(stateSinkObject state.Sink)

+checklocksignore

func (*NotificationHandle) StateTypeName

func (n *NotificationHandle) StateTypeName() string

type PacketInfo

type PacketInfo struct {
	Pkt *stack.PacketBuffer

	// TODO(https://gvisor.dev/issue/6537): Remove these fields.
	Proto tcpip.NetworkProtocolNumber
	Route stack.RouteInfo
}

PacketInfo holds all the information about an outbound packet.