reuseport

Documentation

Overview

Package reuseport provides a basic transport for automatically (and intelligently) reusing TCP ports.

To use, construct a new Transport and configure listeners tr.Listen(...). When dialing (tr.Dial(...)), the transport will attempt to reuse the ports it's currently listening on, choosing the best one depending on the destination address.

It is recommended to set SO_LINGER to 0 for all connections, otherwise reusing the port may fail when re-dialing a recently closed connection. See https://hea-www.harvard.edu/~fine/Tech/addrinuse.html for details.

Index

• Variables
• type Transport
  • func (t *Transport) Dial(raddr ma.Multiaddr) (manet.Conn, error)
  • func (t *Transport) DialContext(ctx context.Context, raddr ma.Multiaddr) (manet.Conn, error)
  • func (t *Transport) Listen(laddr ma.Multiaddr) (manet.Listener, error)

Variables

var ErrWrongProto = errors.New("can only dial TCP over IPv4 or IPv6")

ErrWrongProto is returned when dialing a protocol other than tcp.

Types

type Transport

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

Transport is a TCP reuse transport that reuses listener ports. The zero value is safe to use.

func (*Transport) Dial

func (t *Transport) Dial(raddr ma.Multiaddr) (manet.Conn, error)

Dial dials the given multiaddr, reusing ports we're currently listening on if possible.

Dial attempts to be smart about choosing the source port. For example, If we're dialing a loopback address and we're listening on one or more loopback ports, Dial will randomly choose one of the loopback ports and addresses and reuse it.

func (*Transport) DialContext

func (t *Transport) DialContext(ctx context.Context, raddr ma.Multiaddr) (manet.Conn, error)

DialContext is like Dial but takes a context.

func (*Transport) Listen

func (t *Transport) Listen(laddr ma.Multiaddr) (manet.Listener, error)

Listen listens on the given multiaddr.

If reuseport is supported, it will be enabled for this listener and future dials from this transport may reuse the port.

Note: You can listen on the same multiaddr as many times as you want (although only *one* listener will end up handling the inbound connection).