autonatv2: implement autonatv2 spec (#2469)

Author: sukunrt

config/config.go

@@ -24,6 +24,7 @@ import (
 	"github.com/libp2p/go-libp2p/p2p/host/autonat"
 	"github.com/libp2p/go-libp2p/p2p/host/autorelay"
 	bhost "github.com/libp2p/go-libp2p/p2p/host/basic"
+	blankhost "github.com/libp2p/go-libp2p/p2p/host/blank"
 	"github.com/libp2p/go-libp2p/p2p/host/eventbus"
 	"github.com/libp2p/go-libp2p/p2p/host/peerstore/pstoremem"
 	rcmgr "github.com/libp2p/go-libp2p/p2p/host/resource-manager"
@@ -131,6 +132,13 @@ type Config struct {
 	SwarmOpts []swarm.Option
 
 	DisableIdentifyAddressDiscovery bool
+
+	EnableAutoNATv2 bool
+
+	UDPBlackHoleSuccessCounter        *swarm.BlackHoleSuccessCounter
+	CustomUDPBlackHoleSuccessCounter  bool
+	IPv6BlackHoleSuccessCounter       *swarm.BlackHoleSuccessCounter
+	CustomIPv6BlackHoleSuccessCounter bool
 }
 
 func (cfg *Config) makeSwarm(eventBus event.Bus, enableMetrics bool) (*swarm.Swarm, error) {
@@ -165,7 +173,10 @@ func (cfg *Config) makeSwarm(eventBus event.Bus, enableMetrics bool) (*swarm.Swa
 		return nil, err
 	}
 
-	opts := cfg.SwarmOpts
+	opts := append(cfg.SwarmOpts,
+		swarm.WithUDPBlackHoleSuccessCounter(cfg.UDPBlackHoleSuccessCounter),
+		swarm.WithIPv6BlackHoleSuccessCounter(cfg.IPv6BlackHoleSuccessCounter),
+	)
 	if cfg.Reporter != nil {
 		opts = append(opts, swarm.WithMetrics(cfg.Reporter))
 	}
@@ -193,6 +204,77 @@ func (cfg *Config) makeSwarm(eventBus event.Bus, enableMetrics bool) (*swarm.Swa
 	return swarm.NewSwarm(pid, cfg.Peerstore, eventBus, opts...)
 }
 
+func (cfg *Config) makeAutoNATV2Host() (host.Host, error) {
+	autonatPrivKey, _, err := crypto.GenerateEd25519Key(rand.Reader)
+	if err != nil {
+		return nil, err
+	}
+	ps, err := pstoremem.NewPeerstore()
+	if err != nil {
+		return nil, err
+	}
+
+	autoNatCfg := Config{
+		Transports:                  cfg.Transports,
+		Muxers:                      cfg.Muxers,
+		SecurityTransports:          cfg.SecurityTransports,
+		Insecure:                    cfg.Insecure,
+		PSK:                         cfg.PSK,
+		ConnectionGater:             cfg.ConnectionGater,
+		Reporter:                    cfg.Reporter,
+		PeerKey:                     autonatPrivKey,
+		Peerstore:                   ps,
+		DialRanker:                  swarm.NoDelayDialRanker,
+		UDPBlackHoleSuccessCounter:  cfg.UDPBlackHoleSuccessCounter,
+		IPv6BlackHoleSuccessCounter: cfg.IPv6BlackHoleSuccessCounter,
+		ResourceManager:             cfg.ResourceManager,
+		SwarmOpts: []swarm.Option{
+			// Don't update black hole state for failed autonat dials
+			swarm.WithReadOnlyBlackHoleDetector(),
+		},
+	}
+	fxopts, err := autoNatCfg.addTransports()
+	if err != nil {
+		return nil, err
+	}
+	var dialerHost host.Host
+	fxopts = append(fxopts,
+		fx.Provide(eventbus.NewBus),
+		fx.Provide(func(lifecycle fx.Lifecycle, b event.Bus) (*swarm.Swarm, error) {
+			lifecycle.Append(fx.Hook{
+				OnStop: func(context.Context) error {
+					return ps.Close()
+				}})
+			sw, err := autoNatCfg.makeSwarm(b, false)
+			return sw, err
+		}),
+		fx.Provide(func(sw *swarm.Swarm) *blankhost.BlankHost {
+			return blankhost.NewBlankHost(sw)
+		}),
+		fx.Provide(func(bh *blankhost.BlankHost) host.Host {
+			return bh
+		}),
+		fx.Provide(func() crypto.PrivKey { return autonatPrivKey }),
+		fx.Provide(func(bh host.Host) peer.ID { return bh.ID() }),
+		fx.Invoke(func(bh *blankhost.BlankHost) {
+			dialerHost = bh
+		}),
+	)
+	app := fx.New(fxopts...)
+	if err := app.Err(); err != nil {
+		return nil, err
+	}
+	err = app.Start(context.Background())
+	if err != nil {
+		return nil, err
+	}
+	go func() {
+		<-dialerHost.Network().(*swarm.Swarm).Done()
+		app.Stop(context.Background())
+	}()
+	return dialerHost, nil
+}
+
 func (cfg *Config) addTransports() ([]fx.Option, error) {
 	fxopts := []fx.Option{
 		fx.WithLogger(func() fxevent.Logger { return getFXLogger() }),
@@ -291,6 +373,14 @@ func (cfg *Config) addTransports() ([]fx.Option, error) {
 }
 
 func (cfg *Config) newBasicHost(swrm *swarm.Swarm, eventBus event.Bus) (*bhost.BasicHost, error) {
+	var autonatv2Dialer host.Host
+	if cfg.EnableAutoNATv2 {
+		ah, err := cfg.makeAutoNATV2Host()
+		if err != nil {
+			return nil, err
+		}
+		autonatv2Dialer = ah
+	}
 	h, err := bhost.NewHost(swrm, &bhost.HostOpts{
 		EventBus:                        eventBus,
 		ConnManager:                     cfg.ConnManager,
@@ -306,6 +396,8 @@ func (cfg *Config) newBasicHost(swrm *swarm.Swarm, eventBus event.Bus) (*bhost.B
 		EnableMetrics:                   !cfg.DisableMetrics,
 		PrometheusRegisterer:            cfg.PrometheusRegisterer,
 		DisableIdentifyAddressDiscovery: cfg.DisableIdentifyAddressDiscovery,
+		EnableAutoNATv2:                 cfg.EnableAutoNATv2,
+		AutoNATv2Dialer:                 autonatv2Dialer,
 	})
 	if err != nil {
 		return nil, err
@@ -488,9 +580,8 @@ func (cfg *Config) addAutoNAT(h *bhost.BasicHost) error {
 			Peerstore:          ps,
 			DialRanker:         swarm.NoDelayDialRanker,
 			SwarmOpts: []swarm.Option{
-				// It is better to disable black hole detection and just attempt a dial for autonat
-				swarm.WithUDPBlackHoleConfig(false, 0, 0),
-				swarm.WithIPv6BlackHoleConfig(false, 0, 0),
+				swarm.WithUDPBlackHoleSuccessCounter(nil),
+				swarm.WithIPv6BlackHoleSuccessCounter(nil),
 			},
 		}
 

core/network/network.go

@@ -194,6 +194,9 @@ type Dialer interface {
 	// Notify/StopNotify register and unregister a notifiee for signals
 	Notify(Notifiee)
 	StopNotify(Notifiee)
+
+	// CanDial returns whether the dialer can dial peer p at addr
+	CanDial(p peer.ID, addr ma.Multiaddr) bool
 }
 
 // AddrDelay provides an address along with the delay after which the address

defaults.go

@@ -10,6 +10,7 @@ import (
 	rcmgr "github.com/libp2p/go-libp2p/p2p/host/resource-manager"
 	"github.com/libp2p/go-libp2p/p2p/muxer/yamux"
 	"github.com/libp2p/go-libp2p/p2p/net/connmgr"
+	"github.com/libp2p/go-libp2p/p2p/net/swarm"
 	"github.com/libp2p/go-libp2p/p2p/security/noise"
 	tls "github.com/libp2p/go-libp2p/p2p/security/tls"
 	quic "github.com/libp2p/go-libp2p/p2p/transport/quic"
@@ -133,6 +134,18 @@ var DefaultPrometheusRegisterer = func(cfg *Config) error {
 	return cfg.Apply(PrometheusRegisterer(prometheus.DefaultRegisterer))
 }
 
+var defaultUDPBlackHoleDetector = func(cfg *Config) error {
+	// A black hole is a binary property. On a network if UDP dials are blocked, all dials will
+	// fail. So a low success rate of 5 out 100 dials is good enough.
+	return cfg.Apply(UDPBlackHoleSuccessCounter(&swarm.BlackHoleSuccessCounter{N: 100, MinSuccesses: 5, Name: "UDP"}))
+}
+
+var defaultIPv6BlackHoleDetector = func(cfg *Config) error {
+	// A black hole is a binary property. On a network if there is no IPv6 connectivity, all
+	// dials will fail. So a low success rate of 5 out 100 dials is good enough.
+	return cfg.Apply(IPv6BlackHoleSuccessCounter(&swarm.BlackHoleSuccessCounter{N: 100, MinSuccesses: 5, Name: "IPv6"}))
+}
+
 // Complete list of default options and when to fallback on them.
 //
 // Please *DON'T* specify default options any other way. Putting this all here
@@ -189,6 +202,18 @@ var defaults = []struct {
 		fallback: func(cfg *Config) bool { return !cfg.DisableMetrics && cfg.PrometheusRegisterer == nil },
 		opt:      DefaultPrometheusRegisterer,
 	},
+	{
+		fallback: func(cfg *Config) bool {
+			return !cfg.CustomUDPBlackHoleSuccessCounter && cfg.UDPBlackHoleSuccessCounter == nil
+		},
+		opt: defaultUDPBlackHoleDetector,
+	},
+	{
+		fallback: func(cfg *Config) bool {
+			return !cfg.CustomIPv6BlackHoleSuccessCounter && cfg.IPv6BlackHoleSuccessCounter == nil
+		},
+		opt: defaultIPv6BlackHoleDetector,
+	},
 }
 
 // Defaults configures libp2p to use the default options. Can be combined with

libp2p_test.go

@@ -397,6 +397,12 @@ func TestInsecureConstructor(t *testing.T) {
 	h.Close()
 }
 
+func TestAutoNATv2Service(t *testing.T) {
+	h, err := New(EnableAutoNATv2())
+	require.NoError(t, err)
+	h.Close()
+}
+
 func TestDisableIdentifyAddressDiscovery(t *testing.T) {
 	h, err := New(DisableIdentifyAddressDiscovery())
 	require.NoError(t, err)

options.go

@@ -609,3 +609,29 @@ func DisableIdentifyAddressDiscovery() Option {
 		return nil
 	}
 }
+
+// EnableAutoNATv2 enables autonat v2
+func EnableAutoNATv2() Option {
+	return func(cfg *Config) error {
+		cfg.EnableAutoNATv2 = true
+		return nil
+	}
+}
+
+// UDPBlackHoleSuccessCounter configures libp2p to use f as the black hole filter for UDP addrs
+func UDPBlackHoleSuccessCounter(f *swarm.BlackHoleSuccessCounter) Option {
+	return func(cfg *Config) error {
+		cfg.UDPBlackHoleSuccessCounter = f
+		cfg.CustomUDPBlackHoleSuccessCounter = true
+		return nil
+	}
+}
+
+// IPv6BlackHoleSuccessCounter configures libp2p to use f as the black hole filter for IPv6 addrs
+func IPv6BlackHoleSuccessCounter(f *swarm.BlackHoleSuccessCounter) Option {
+	return func(cfg *Config) error {
+		cfg.IPv6BlackHoleSuccessCounter = f
+		cfg.CustomIPv6BlackHoleSuccessCounter = true
+		return nil
+	}
+}

p2p/host/basic/basic_host.go

@@ -24,6 +24,7 @@ import (
 	"github.com/libp2p/go-libp2p/p2p/host/eventbus"
 	"github.com/libp2p/go-libp2p/p2p/host/pstoremanager"
 	"github.com/libp2p/go-libp2p/p2p/host/relaysvc"
+	"github.com/libp2p/go-libp2p/p2p/protocol/autonatv2"
 	relayv2 "github.com/libp2p/go-libp2p/p2p/protocol/circuitv2/relay"
 	"github.com/libp2p/go-libp2p/p2p/protocol/holepunch"
 	"github.com/libp2p/go-libp2p/p2p/protocol/identify"
@@ -105,6 +106,8 @@ type BasicHost struct {
 	caBook                  peerstore.CertifiedAddrBook
 
 	autoNat autonat.AutoNAT
+
+	autonatv2 *autonatv2.AutoNAT
 }
 
 var _ host.Host = (*BasicHost)(nil)
@@ -167,6 +170,8 @@ type HostOpts struct {
 
 	// DisableIdentifyAddressDiscovery disables address discovery using peer provided observed addresses in identify
 	DisableIdentifyAddressDiscovery bool
+	EnableAutoNATv2                 bool
+	AutoNATv2Dialer                 host.Host
 }
 
 // NewHost constructs a new *BasicHost and activates it by attaching its stream and connection handlers to the given inet.Network.
@@ -310,6 +315,13 @@ func NewHost(n network.Network, opts *HostOpts) (*BasicHost, error) {
 		h.pings = ping.NewPingService(h)
 	}
 
+	if opts.EnableAutoNATv2 {
+		h.autonatv2, err = autonatv2.New(h, opts.AutoNATv2Dialer)
+		if err != nil {
+			return nil, fmt.Errorf("failed to create autonatv2: %w", err)
+		}
+	}
+
 	n.SetStreamHandler(h.newStreamHandler)
 
 	// register to be notified when the network's listen addrs change,
@@ -398,6 +410,12 @@ func (h *BasicHost) Start() {
 	h.psManager.Start()
 	h.refCount.Add(1)
 	h.ids.Start()
+	if h.autonatv2 != nil {
+		err := h.autonatv2.Start()
+		if err != nil {
+			log.Errorf("autonat v2 failed to start: %s", err)
+		}
+	}
 	go h.background()
 }
 
@@ -1100,6 +1118,9 @@ func (h *BasicHost) Close() error {
 		if h.hps != nil {
 			h.hps.Close()
 		}
+		if h.autonatv2 != nil {
+			h.autonatv2.Close()
+		}
 
 		_ = h.emitters.evtLocalProtocolsUpdated.Close()
 		_ = h.emitters.evtLocalAddrsUpdated.Close()

p2p/net/mock/mock_peernet.go

@@ -434,3 +434,7 @@ func (pn *peernet) notifyAll(notification func(f network.Notifiee)) {
 func (pn *peernet) ResourceManager() network.ResourceManager {
 	return &network.NullResourceManager{}
 }
+
+func (pn *peernet) CanDial(p peer.ID, addr ma.Multiaddr) bool {
+	return true
+}