libp2p

README

The Go implementation of the libp2p Networking Stack.

Table of Contents

• Background
• Usage
  • Examples
• Development
  • Using the go-libp2p Workspace
  • Tests
  • Packages
• Contribute
• Supported Go Versions

Background

libp2p is a networking stack and library modularized out of The IPFS Project, and bundled separately for other tools to use.

libp2p is the product of a long, and arduous quest of understanding -- a deep dive into the internet's network stack, and plentiful peer-to-peer protocols from the past. Building large-scale peer-to-peer systems has been complex and difficult in the last 15 years, and libp2p is a way to fix that. It is a "network stack" -- a protocol suite -- that cleanly separates concerns, and enables sophisticated applications to only use the protocols they absolutely need, without giving up interoperability and upgradeability. libp2p grew out of IPFS, but it is built so that lots of people can use it, for lots of different projects.

To learn more, check out the following resources:

• Our documentation
• Our community discussion forum
• The libp2p Specification
• js-libp2p implementation
• rust-libp2p implementation

Usage

This repository (go-libp2p) serves as the entrypoint to the universe of modules that compose the Go implementation of the libp2p stack.

You can start using go-libp2p in your Go application simply by adding imports from our repos, e.g.:

import "github.com/libp2p/go-libp2p"

Examples

Examples can be found in the examples folder.

Development

Using the go-libp2p Workspace

While developing, you may need to make changes to several modules at once, or you may want changes made locally in one module to be available for import by another.

The go-libp2p workspace provides a developer-oriented view of the modules that comprise go-libp2p.

Using the tooling in the workspace repository, you can checkout all of go-libp2p's module repos and enter "local mode", which adds replace directives to the go.mod files in each local working copy. When you build locally, the libp2p depdendencies will be resolved from your local working copies.

Once you've committed your changes, you can switch back to "remote mode", which removes the replace directives and pulls imports from the main go module cache.

See the workspace repo for more information.

Tests

go test ./... will run all tests in the repo.

Packages

This table is generated using the module package-table with package-table --data=package-list.json.

List of packages currently in existence for libp2p:

Name	CI/Travis	Coverage	Description
Libp2p
go-libp2p			go-libp2p entry point
go-libp2p-core			core interfaces, types, and abstractions
go-libp2p-blankhost			minimal implementation of the "host" interface
Network
go-libp2p-swarm			reference implementation of network state machine
Transport
go-ws-transport			WebSocket transport
go-tcp-transport			TCP transport
go-libp2p-quic-transport			QUIC transport
go-udp-transport			UDP transport
go-utp-transport			uTorrent transport (UTP)
go-libp2p-circuit			relay transport
go-libp2p-transport-upgrader			upgrades multiaddr-net connections into full libp2p transports
go-libp2p-reuseport-transport			partial transport for building transports that reuse ports
Encrypted Channels
go-libp2p-noise			Noise crypto channel
go-libp2p-tls			TLS 1.3+ crypto channel
go-conn-security-multistream			multistream multiplexed meta crypto channel
Private Network
go-libp2p-pnet			reference private networking implementation
Stream Muxers
go-libp2p-yamux			YAMUX stream multiplexer
go-libp2p-mplex			MPLEX stream multiplexer
NAT Traversal
go-libp2p-nat
Peerstore
go-libp2p-peerstore			reference implementation of peer metadata storage component
Connection Manager
go-libp2p-connmgr			reference implementation of connection manager
Routing
go-libp2p-record			record type and validator logic
go-libp2p-kad-dht			Kademlia-like router
go-libp2p-kbucket			Kademlia routing table helper types
go-libp2p-coral-dht			Router based on Coral DHT
go-libp2p-pubsub-router			record-store over pubsub adapter
Consensus
go-libp2p-consensus			consensus protocols interfaces
go-libp2p-raft			consensus implementation over raft
Pubsub
go-libp2p-pubsub			multiple pubsub over libp2p implementations
RPC
go-libp2p-gorpc			a simple RPC library for libp2p
Utilities/miscellaneous
go-libp2p-loggables			logging helpers
go-maddr-filter			multiaddr filtering helpers
go-libp2p-netutil			misc utilities
go-msgio			length prefixed data channel
go-addr-util			address utilities for libp2p swarm
go-buffer-pool			a variable size buffer pool for go
go-libp2p-routing-helpers			routing helpers
go-reuseport			enables reuse of addresses
go-sockaddr			utils for sockaddr conversions
go-flow-metrics			metrics library
go-libp2p-gostream			Go 'net' wrappers for libp2p
go-libp2p-http			HTTP on top of libp2p streams
Testing and examples
go-libp2p-testing			a collection of testing utilities for libp2p

Contribute

go-libp2p is part of The IPFS Project, and is MIT-licensed open source software. We welcome contributions big and small! Take a look at the community contributing notes. Please make sure to check the issues. Search the closed ones before reporting things, and help us with the open ones.

Guidelines:

• read the libp2p spec
• ask questions or talk about things in our discussion forums, or open an issue for bug reports, or #libp2p on freenode.
• ensure you are able to contribute (no legal issues please -- we use the DCO)
• get in touch with @marten-seemann about how best to contribute
• have fun!

There's a few things you can do right now to help out:

• Go through the modules below and check out existing issues. This would be especially useful for modules in active development. Some knowledge of IPFS/libp2p may be required, as well as the infrasture behind it - for instance, you may need to read up on p2p and more complex operations like muxing to be able to help technically.
• Perform code reviews.
• Add tests. There can never be enough tests.

Supported Go Versions

We test against and support the two most recent major releases of Go. This is informed by Go's own security policy.

Documentation

Index

• Variables
• func New(opts ...Option) (host.Host, error)
• func NewWithoutDefaults(opts ...Option) (host.Host, error)
• func SetDefaultServiceLimits(limiter *rcmgr.BasicLimiter)
• type Config
• type Option
  • func AddrsFactory(factory config.AddrsFactory) Option
  • func AutoNATServiceRateLimit(global, perPeer int, interval time.Duration) Option
  • func BandwidthReporter(rep metrics.Reporter) Option
  • func ChainOptions(opts ...Option) Option
  • func ConnectionGater(cg connmgr.ConnectionGater) Option
  • func ConnectionManager(connman connmgr.ConnManager) Option
  • func DefaultStaticRelays() Option
  • func DisableRelay() Option
  • func EnableAutoRelay(opts ...autorelay.Option) Option
  • func EnableHolePunching(opts ...holepunch.Option) Option
  • func EnableNATService() Option
  • func EnableRelay() Option
  • func EnableRelayService(opts ...relayv2.Option) Option
  • func ForceReachabilityPrivate() Option
  • func ForceReachabilityPublic() Option
  • func Identity(sk crypto.PrivKey) Option
  • func ListenAddrStrings(s ...string) Option
  • func ListenAddrs(addrs ...ma.Multiaddr) Option
  • func MultiaddrResolver(rslv *madns.Resolver) Option
  • func Muxer(name string, tpt interface{}) Option
  • func NATManager(nm config.NATManagerC) Option
  • func NATPortMap() Option
  • func Peerstore(ps peerstore.Peerstore) Option
  • func Ping(enable bool) Option
  • func PrivateNetwork(psk pnet.PSK) Option
  • func ResourceManager(rcmgr network.ResourceManager) Option
  • func Routing(rt config.RoutingC) Option
  • func Security(name string, tpt interface{}) Option
  • func StaticRelays(relays []peer.AddrInfo) Option
  • func Transport(tpt interface{}, opts ...interface{}) Option
  • func UserAgent(userAgent string) Option
  • func WithDialTimeout(t time.Duration) Option

Variables

var DefaultConnectionManager = func(cfg *Config) error {
	mgr, err := connmgr.NewConnManager(160, 192)
	if err != nil {
		return err
	}

	return cfg.Apply(ConnectionManager(mgr))
}

DefaultConnManager creates a default connection manager

var DefaultEnableRelay = func(cfg *Config) error {
	return cfg.Apply(EnableRelay())
}

DefaultEnableRelay enables relay dialing and listening by default.

var DefaultListenAddrs = func(cfg *Config) error {
	defaultIP4ListenAddr, err := multiaddr.NewMultiaddr("/ip4/0.0.0.0/tcp/0")
	if err != nil {
		return err
	}

	defaultIP6ListenAddr, err := multiaddr.NewMultiaddr("/ip6/::/tcp/0")
	if err != nil {
		return err
	}
	return cfg.Apply(ListenAddrs(
		defaultIP4ListenAddr,
		defaultIP6ListenAddr,
	))
}

DefaultListenAddrs configures libp2p to use default listen address.

var DefaultMuxers = Muxer("/yamux/1.0.0", yamux.DefaultTransport)

DefaultMuxers configures libp2p to use the stream connection multiplexers.

Use this option when you want to *extend* the set of multiplexers used by libp2p instead of replacing them.

var DefaultResourceManager = func(cfg *Config) error {

	limiter := rcmgr.NewDefaultLimiter()
	SetDefaultServiceLimits(limiter)

	mgr, err := rcmgr.NewResourceManager(limiter)
	if err != nil {
		return err
	}

	return cfg.Apply(ResourceManager(mgr))
}

var DefaultSecurity = ChainOptions(
	Security(noise.ID, noise.New),
	Security(tls.ID, tls.New),
)

DefaultSecurity is the default security option.

Useful when you want to extend, but not replace, the supported transport security protocols.

var DefaultTransports = ChainOptions(
	Transport(tcp.NewTCPTransport),
	Transport(quic.NewTransport),
	Transport(ws.New),
)

DefaultTransports are the default libp2p transports.

Use this option when you want to *extend* the set of transports used by libp2p instead of replacing them.

var NoListenAddrs = func(cfg *Config) error {
	cfg.ListenAddrs = []ma.Multiaddr{}
	if !cfg.RelayCustom {
		cfg.RelayCustom = true
		cfg.Relay = false
	}
	return nil
}

NoListenAddrs will configure libp2p to not listen by default.

This will both clear any configured listen addrs and prevent libp2p from applying the default listen address option. It also disables relay, unless the user explicitly specifies with an option, as the transport creates an implicit listen address that would make the node dialable through any relay it was connected to.

var NoTransports = func(cfg *Config) error {
	cfg.Transports = []config.TptC{}
	return nil
}

NoTransports will configure libp2p to not enable any transports.

This will both clear any configured transports (specified in prior libp2p options) and prevent libp2p from applying the default transports.

var RandomIdentity = func(cfg *Config) error {
	priv, _, err := crypto.GenerateKeyPairWithReader(crypto.RSA, 2048, rand.Reader)
	if err != nil {
		return err
	}
	return cfg.Apply(Identity(priv))
}

RandomIdentity generates a random identity. (default behaviour)

Functions

func New

func New(opts ...Option) (host.Host, error)

New constructs a new libp2p node with the given options, falling back on reasonable defaults. The defaults are:

- If no transport and listen addresses are provided, the node listens to the multiaddresses "/ip4/0.0.0.0/tcp/0" and "/ip6/::/tcp/0";

- If no transport options are provided, the node uses TCP, websocket and QUIC transport protocols;

- If no multiplexer configuration is provided, the node is configured by default to use the "yamux/1.0.0" and "mplux/6.7.0" stream connection multiplexers;

- If no security transport is provided, the host uses the go-libp2p's noise and/or tls encrypted transport to encrypt all traffic;

- If no peer identity is provided, it generates a random RSA 2048 key-pair and derives a new identity from it;

- If no peerstore is provided, the host is initialized with an empty peerstore.

To stop/shutdown the returned libp2p node, the user needs to cancel the passed context and call `Close` on the returned Host.

func NewWithoutDefaults

func NewWithoutDefaults(opts ...Option) (host.Host, error)

NewWithoutDefaults constructs a new libp2p node with the given options but *without* falling back on reasonable defaults.

Warning: This function should not be considered a stable interface. We may choose to add required services at any time and, by using this function, you opt-out of any defaults we may provide.

func SetDefaultServiceLimits

func SetDefaultServiceLimits(limiter *rcmgr.BasicLimiter)

SetDefaultServiceLimits sets the default limits for bundled libp2p services

More specifically this sets the following limits:

• identify: 128 streams in, 128 streams out, 256 streams total, 4MB min, 64MB max svc memory 16/16/32 streams per peer
• ping: 128 streams in, 128 sreams out, 256 streasms total, 4MB min, 64MB max svc memory 2/3/4 streams per peer
• autonat 128 streams in, 128 streams out, 128 streams total, 4MB min, 64MB max svc memory 2/2/2 streams per peer
• holepunch 128 streams in, 128 streams out, 128 streams total, 4MB min, 64MB max svc memory 2/2/2 streams per peer
• relay v1 and v2 (separate services) 1024 streams in, 1024 streams out, 1024 streams total, 4MB min, 64MB max svc memory 64/64/64 streams per peer

Types

type Config

type Config = config.Config

Config describes a set of settings for a libp2p node.

type Option

type Option = config.Option

Option is a libp2p config option that can be given to the libp2p constructor (`libp2p.New`).

var DefaultPeerstore Option = func(cfg *Config) error {
	ps, err := pstoremem.NewPeerstore()
	if err != nil {
		return err
	}
	return cfg.Apply(Peerstore(ps))
}

DefaultPeerstore configures libp2p to use the default peerstore.

var Defaults Option = func(cfg *Config) error {
	for _, def := range defaults {
		if err := cfg.Apply(def.opt); err != nil {
			return err
		}
	}
	return nil
}

Defaults configures libp2p to use the default options. Can be combined with other options to *extend* the default options.

var FallbackDefaults Option = func(cfg *Config) error {
	for _, def := range defaults {
		if !def.fallback(cfg) {
			continue
		}
		if err := cfg.Apply(def.opt); err != nil {
			return err
		}
	}
	return nil
}

FallbackDefaults applies default options to the libp2p node if and only if no other relevant options have been applied. will be appended to the options passed into New.

var NoSecurity Option = func(cfg *Config) error {
	if len(cfg.SecurityTransports) > 0 {
		return fmt.Errorf("cannot use security transports with an insecure libp2p configuration")
	}
	cfg.Insecure = true
	return nil
}

NoSecurity is an option that completely disables all transport security. It's incompatible with all other transport security protocols.

func AddrsFactory

func AddrsFactory(factory config.AddrsFactory) Option

AddrsFactory configures libp2p to use the given address factory.

func AutoNATServiceRateLimit

func AutoNATServiceRateLimit(global, perPeer int, interval time.Duration) Option

AutoNATServiceRateLimit changes the default rate limiting configured in helping other peers determine their reachability status. When set, the host will limit the number of requests it responds to in each 60 second period to the set numbers. A value of '0' disables throttling.

func BandwidthReporter

func BandwidthReporter(rep metrics.Reporter) Option

BandwidthReporter configures libp2p to use the given bandwidth reporter.

func ChainOptions

func ChainOptions(opts ...Option) Option

ChainOptions chains multiple options into a single option.

func ConnectionGater

func ConnectionGater(cg connmgr.ConnectionGater) Option

ConnectionGater configures libp2p to use the given ConnectionGater to actively reject inbound/outbound connections based on the lifecycle stage of the connection.

For more information, refer to go-libp2p-core.ConnectionGater.

func ConnectionManager

func ConnectionManager(connman connmgr.ConnManager) Option

ConnectionManager configures libp2p to use the given connection manager.

The current "standard" connection manager lives in github.com/libp2p/go-libp2p-connmgr. See https://pkg.go.dev/github.com/libp2p/go-libp2p-connmgr?utm_source=godoc#NewConnManager.

func DefaultStaticRelays

func DefaultStaticRelays() Option

DefaultStaticRelays configures the static relays to use the known PL-operated relays. Deprecated: pass autorelay.WithDefaultStaticRelays to EnableAutoRelay.

func DisableRelay

func DisableRelay() Option

DisableRelay configures libp2p to disable the relay transport.

func EnableAutoRelay

func EnableAutoRelay(opts ...autorelay.Option) Option

EnableAutoRelay configures libp2p to enable the AutoRelay subsystem.

Dependencies:

• Relay (enabled by default)
• Routing (to find relays), or StaticRelays/DefaultStaticRelays.

This subsystem performs automatic address rewriting to advertise relay addresses when it detects that the node is publicly unreachable (e.g. behind a NAT).

func EnableHolePunching

func EnableHolePunching(opts ...holepunch.Option) Option

Experimental EnableHolePunching enables NAT traversal by enabling NATT'd peers to both initiate and respond to hole punching attempts to create direct/NAT-traversed connections with other peers. (default: disabled)

Dependencies:

• Relay (enabled by default)

This subsystem performs two functions:

1. On receiving an inbound Relay connection, it attempts to create a direct connection with the remote peer by initiating and co-ordinating a hole punch over the Relayed connection.
2. If a peer sees a request to co-ordinate a hole punch on an outbound Relay connection, it will participate in the hole-punch to create a direct connection with the remote peer.

If the hole punch is successful, all new streams will thereafter be created on the hole-punched connection. The Relayed connection will eventually be closed after a grace period.

All existing indefinite long-lived streams on the Relayed connection will have to re-opened on the hole-punched connection by the user. Users can make use of the `Connected`/`Disconnected` notifications emitted by the Network for this purpose.

It is not mandatory but nice to also enable the `AutoRelay` option (See `EnableAutoRelay`) so the peer can discover and connect to Relay servers if it discovers that it is NATT'd and has private reachability via AutoNAT. This will then enable it to advertise Relay addresses which can be used to accept inbound Relay connections to then co-ordinate a hole punch.

If `EnableAutoRelay` is configured and the user is confident that the peer has private reachability/is NATT'd, the `ForceReachabilityPrivate` option can be configured to short-circuit reachability discovery via AutoNAT so the peer can immediately start connecting to Relay servers.

If `EnableAutoRelay` is configured, the `StaticRelays` option can be used to configure a static set of Relay servers for `AutoRelay` to connect to so that it does not need to discover Relay servers via Routing.

func EnableNATService

func EnableNATService() Option

EnableNATService configures libp2p to provide a service to peers for determining their reachability status. When enabled, the host will attempt to dial back to peers, and then tell them if it was successful in making such connections.

func EnableRelay

func EnableRelay() Option

EnableRelay configures libp2p to enable the relay transport. This option only configures libp2p to accept inbound connections from relays and make outbound connections_through_ relays when requested by the remote peer. This option supports both circuit v1 and v2 connections. (default: enabled)

func EnableRelayService

func EnableRelayService(opts ...relayv2.Option) Option

EnableRelayService configures libp2p to run a circuit v2 relay, if we detect that we're publicly reachable.

func ForceReachabilityPrivate

func ForceReachabilityPrivate() Option

ForceReachabilityPrivate overrides automatic reachability detection in the AutoNAT subsystem, forceing the local node to believe it is behind a NAT and not reachable externally.

func ForceReachabilityPublic

func ForceReachabilityPublic() Option

ForceReachabilityPublic overrides automatic reachability detection in the AutoNAT subsystem, forcing the local node to believe it is reachable externally.

func Identity

func Identity(sk crypto.PrivKey) Option

Identity configures libp2p to use the given private key to identify itself.

func ListenAddrStrings

func ListenAddrStrings(s ...string) Option

ListenAddrStrings configures libp2p to listen on the given (unparsed) addresses.

func ListenAddrs

func ListenAddrs(addrs ...ma.Multiaddr) Option

ListenAddrs configures libp2p to listen on the given addresses.

func MultiaddrResolver

func MultiaddrResolver(rslv *madns.Resolver) Option

MultiaddrResolver sets the libp2p dns resolver

func Muxer

func Muxer(name string, tpt interface{}) Option

Muxer configures libp2p to use the given stream multiplexer (or stream multiplexer constructor).

Name is the protocol name.

The transport can be a constructed mux.Transport or a function taking any subset of this libp2p node's: * Peer ID * Host * Network * Peerstore

func NATManager

func NATManager(nm config.NATManagerC) Option

NATManager will configure libp2p to use the requested NATManager. This function should be passed a NATManager *constructor* that takes a libp2p Network.

func NATPortMap

func NATPortMap() Option

NATPortMap configures libp2p to use the default NATManager. The default NATManager will attempt to open a port in your network's firewall using UPnP.

func Peerstore

func Peerstore(ps peerstore.Peerstore) Option

Peerstore configures libp2p to use the given peerstore.

func Ping

func Ping(enable bool) Option

Ping will configure libp2p to support the ping service; enable by default.

func PrivateNetwork

func PrivateNetwork(psk pnet.PSK) Option

PrivateNetwork configures libp2p to use the given private network protector.

func ResourceManager

func ResourceManager(rcmgr network.ResourceManager) Option

ResourceManager configures libp2p to use the given ResourceManager.

func Routing

func Routing(rt config.RoutingC) Option

Routing will configure libp2p to use routing.

func Security

func Security(name string, tpt interface{}) Option

Security configures libp2p to use the given security transport (or transport constructor).

Name is the protocol name.

The transport can be a constructed security.Transport or a function taking any subset of this libp2p node's: * Public key * Private key * Peer ID * Host * Network * Peerstore

func StaticRelays

func StaticRelays(relays []peer.AddrInfo) Option

StaticRelays configures known relays for autorelay; when this option is enabled then the system will use the configured relays instead of querying the DHT to discover relays. Deprecated: pass an autorelay.WithStaticRelays option to EnableAutoRelay.

func Transport

func Transport(tpt interface{}, opts ...interface{}) Option

Transport configures libp2p to use the given transport (or transport constructor).

The transport can be a constructed transport.Transport or a function taking any subset of this libp2p node's: * Transport Upgrader (*tptu.Upgrader) * Host * Stream muxer (muxer.Transport) * Security transport (security.Transport) * Private network protector (pnet.Protector) * Peer ID * Private Key * Public Key * Address filter (filter.Filter) * Peerstore

func UserAgent

func UserAgent(userAgent string) Option

UserAgent sets the libp2p user-agent sent along with the identify protocol

func WithDialTimeout

func WithDialTimeout(t time.Duration) Option