transport

Documentation

Overview

Package transport provides the Transport interface, which represents the devices and network protocols used to send and receive data.

Index

• Variables
• type CapableConn
• type DialUpdate
• type DialUpdateKind
  • func (k DialUpdateKind) String() string
• type DialUpdater
• type Listener
• type Resolver
• type Transport
• type TransportNetwork
• type Upgrader

Variables

var ErrListenerClosed = errors.New("listener closed")

ErrListenerClosed is returned by Listener.Accept when the listener is gracefully closed.

Types

type CapableConn

type CapableConn interface {
	network.MuxedConn
	network.ConnSecurity
	network.ConnMultiaddrs
	network.ConnScoper

	// Transport returns the transport to which this connection belongs.
	Transport() Transport
}

A CapableConn represents a connection that has offers the basic capabilities required by libp2p: stream multiplexing, encryption and peer authentication.

These capabilities may be natively provided by the transport, or they may be shimmed via the "connection upgrade" process, which converts a "raw" network connection into one that supports such capabilities by layering an encryption channel and a stream multiplexer.

CapableConn provides accessors for the local and remote multiaddrs used to establish the connection and an accessor for the underlying Transport.

type DialUpdate

type DialUpdate struct {
	// Kind is the kind of update event.
	Kind DialUpdateKind
	// Addr is the peer's address.
	Addr ma.Multiaddr
	// Conn is the resulting connection on success.
	Conn CapableConn
	// Err is the reason for dial failure.
	Err error
}

DialUpdate is used by DialUpdater to provide dial updates.

type DialUpdateKind

type DialUpdateKind int

DialUpdateKind indicates the type of DialUpdate event.

const (
	// UpdateKindDialFailed indicates dial failed.
	UpdateKindDialFailed DialUpdateKind = iota
	// UpdateKindDialSuccessful indicates dial succeeded.
	UpdateKindDialSuccessful
	// UpdateKindHandshakeProgressed indicates successful completion of the TCP 3-way
	// handshake
	UpdateKindHandshakeProgressed
)

func (DialUpdateKind) String

func (k DialUpdateKind) String() string

type DialUpdater

type DialUpdater interface {
	// DialWithUpdates dials a remote peer and provides updates on the passed channel.
	DialWithUpdates(context.Context, ma.Multiaddr, peer.ID, chan<- DialUpdate) (CapableConn, error)
}

DialUpdater provides updates on in progress dials.

type Listener

type Listener interface {
	Accept() (CapableConn, error)
	Close() error
	Addr() net.Addr
	Multiaddr() ma.Multiaddr
}

Listener is an interface closely resembling the net.Listener interface. The only real difference is that Accept() returns Conn's of the type in this package, and also exposes a Multiaddr method as opposed to a regular Addr method

type Resolver

type Resolver interface {
	Resolve(ctx context.Context, maddr ma.Multiaddr) ([]ma.Multiaddr, error)
}

Resolver can be optionally implemented by transports that want to resolve or transform the multiaddr.

type Transport

type Transport interface {
	// Dial dials a remote peer. It should try to reuse local listener
	// addresses if possible, but it may choose not to.
	Dial(ctx context.Context, raddr ma.Multiaddr, p peer.ID) (CapableConn, error)

	// CanDial returns true if this transport knows how to dial the given
	// multiaddr.
	//
	// Returning true does not guarantee that dialing this multiaddr will
	// succeed. This function should *only* be used to preemptively filter
	// out addresses that we can't dial.
	CanDial(addr ma.Multiaddr) bool

	// Listen listens on the passed multiaddr.
	Listen(laddr ma.Multiaddr) (Listener, error)

	// Protocol returns the set of protocols handled by this transport.
	//
	// See the Network interface for an explanation of how this is used.
	Protocols() []int

	// Proxy returns true if this is a proxy transport.
	//
	// See the Network interface for an explanation of how this is used.
	// TODO: Make this a part of the go-multiaddr protocol instead?
	Proxy() bool
}

Transport represents any device by which you can connect to and accept connections from other peers.

The Transport interface allows you to open connections to other peers by dialing them, and also lets you listen for incoming connections.

Connections returned by Dial and passed into Listeners are of type CapableConn, which means that they have been upgraded to support stream multiplexing and connection security (encryption and authentication).

If a transport implements `io.Closer` (optional), libp2p will call `Close` on shutdown. NOTE: `Dial` and `Listen` may be called after or concurrently with `Close`.

For a conceptual overview, see https://docs.libp2p.io/concepts/transport/

type TransportNetwork

type TransportNetwork interface {
	network.Network

	// AddTransport adds a transport to this Network.
	//
	// When dialing, this Network will iterate over the protocols in the
	// remote multiaddr and pick the first protocol registered with a proxy
	// transport, if any. Otherwise, it'll pick the transport registered to
	// handle the last protocol in the multiaddr.
	//
	// When listening, this Network will iterate over the protocols in the
	// local multiaddr and pick the *last* protocol registered with a proxy
	// transport, if any. Otherwise, it'll pick the transport registered to
	// handle the last protocol in the multiaddr.
	AddTransport(t Transport) error
}

TransportNetwork is an inet.Network with methods for managing transports.

type Upgrader

type Upgrader interface {
	// UpgradeListener upgrades the passed multiaddr-net listener into a full libp2p-transport listener.
	UpgradeListener(Transport, manet.Listener) Listener
	// Upgrade upgrades the multiaddr/net connection into a full libp2p-transport connection.
	Upgrade(ctx context.Context, t Transport, maconn manet.Conn, dir network.Direction, p peer.ID, scope network.ConnManagementScope) (CapableConn, error)
}

Upgrader is a multistream upgrader that can upgrade an underlying connection to a full transport connection (secure and multiplexed).