Release v0.27.7

p2p/net/swarm/swarm.go

@@ -329,12 +329,7 @@ func (s *Swarm) addConn(tc transport.CapableConn, dir network.Direction) (*Conn,
 	}
 
 	c.streams.m = make(map[*Stream]struct{})
-	if len(s.conns.m[p]) == 0 { // first connection
-		s.emitter.Emit(event.EvtPeerConnectednessChanged{
-			Peer:          p,
-			Connectedness: network.Connected,
-		})
-	}
+	isFirstConnection := len(s.conns.m[p]) == 0
 	s.conns.m[p] = append(s.conns.m[p], c)
 
 	// Add two swarm refs:
@@ -347,6 +342,15 @@ func (s *Swarm) addConn(tc transport.CapableConn, dir network.Direction) (*Conn,
 	c.notifyLk.Lock()
 	s.conns.Unlock()
 
+	// Emit event after releasing `s.conns` lock so that a consumer can still
+	// use swarm methods that need the `s.conns` lock.
+	if isFirstConnection {
+		s.emitter.Emit(event.EvtPeerConnectednessChanged{
+			Peer:          p,
+			Connectedness: network.Connected,
+		})
+	}
+
 	s.notifyAll(func(f network.Notifiee) {
 		f.Connected(s, c)
 	})
@@ -626,25 +630,32 @@ func (s *Swarm) removeConn(c *Conn) {
 	p := c.RemotePeer()
 
 	s.conns.Lock()
-	defer s.conns.Unlock()
 
 	cs := s.conns.m[p]
+
+	if len(cs) == 1 {
+		delete(s.conns.m, p)
+		s.conns.Unlock()
+
+		// Emit event after releasing `s.conns` lock so that a consumer can still
+		// use swarm methods that need the `s.conns` lock.
+		s.emitter.Emit(event.EvtPeerConnectednessChanged{
+			Peer:          p,
+			Connectedness: network.NotConnected,
+		})
+		return
+	}
+
+	defer s.conns.Unlock()
+
 	for i, ci := range cs {
 		if ci == c {
-			if len(cs) == 1 {
-				delete(s.conns.m, p)
-				s.emitter.Emit(event.EvtPeerConnectednessChanged{
-					Peer:          p,
-					Connectedness: network.NotConnected,
-				})
-			} else {
-				// NOTE: We're intentionally preserving order.
-				// This way, connections to a peer are always
-				// sorted oldest to newest.
-				copy(cs[i:], cs[i+1:])
-				cs[len(cs)-1] = nil
-				s.conns.m[p] = cs[:len(cs)-1]
-			}
+			// NOTE: We're intentionally preserving order.
+			// This way, connections to a peer are always
+			// sorted oldest to newest.
+			copy(cs[i:], cs[i+1:])
+			cs[len(cs)-1] = nil
+			s.conns.m[p] = cs[:len(cs)-1]
 			break
 		}
 	}

p2p/net/swarm/swarm_event_test.go

@@ -64,3 +64,52 @@ func TestConnectednessEventsSingleConn(t *testing.T) {
 	checkEvent(t, sub1, event.EvtPeerConnectednessChanged{Peer: s2.LocalPeer(), Connectedness: network.NotConnected})
 	checkEvent(t, sub2, event.EvtPeerConnectednessChanged{Peer: s1.LocalPeer(), Connectedness: network.NotConnected})
 }
+
+func TestNoDeadlockWhenConsumingConnectednessEvents(t *testing.T) {
+	dialerEventBus := eventbus.NewBus()
+	dialer := swarmt.GenSwarm(t, swarmt.OptDialOnly, swarmt.EventBus(dialerEventBus))
+	defer dialer.Close()
+
+	listener := swarmt.GenSwarm(t, swarmt.OptDialOnly)
+	addrsToListen := []ma.Multiaddr{
+		ma.StringCast("/ip4/127.0.0.1/udp/0/quic-v1"),
+	}
+
+	if err := listener.Listen(addrsToListen...); err != nil {
+		t.Fatal(err)
+	}
+	listenedAddrs := listener.ListenAddresses()
+
+	dialer.Peerstore().AddAddrs(listener.LocalPeer(), listenedAddrs, time.Hour)
+
+	sub, err := dialerEventBus.Subscribe(new(event.EvtPeerConnectednessChanged))
+	require.NoError(t, err)
+
+	ctx := context.Background()
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
+	// A slow consumer
+	go func() {
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case <-sub.Out():
+				time.Sleep(100 * time.Millisecond)
+				// Do something with the swarm that needs the conns lock
+				_ = dialer.ConnsToPeer(listener.LocalPeer())
+				time.Sleep(100 * time.Millisecond)
+			}
+		}
+	}()
+
+	for i := 0; i < 10; i++ {
+		// Connect and disconnect to trigger a bunch of events
+		_, err := dialer.DialPeer(context.Background(), listener.LocalPeer())
+		require.NoError(t, err)
+		dialer.ClosePeer(listener.LocalPeer())
+	}
+
+	// The test should finish without deadlocking
+}

p2p/protocol/identify/id.go

@@ -48,8 +48,7 @@ const ServiceName = "libp2p.identify"
 
 const maxPushConcurrency = 32
 
-// StreamReadTimeout is the read timeout on all incoming Identify family streams.
-var StreamReadTimeout = 60 * time.Second
+var Timeout = 60 * time.Second // timeout on all incoming Identify interactions
 
 const (
 	legacyIDSize = 2 * 1024 // 2k Bytes
@@ -416,11 +415,14 @@ func (ids *idService) IdentifyWait(c network.Conn) <-chan struct{} {
 }
 
 func (ids *idService) identifyConn(c network.Conn) error {
-	s, err := c.NewStream(network.WithUseTransient(context.TODO(), "identify"))
+	ctx, cancel := context.WithTimeout(context.Background(), Timeout)
+	defer cancel()
+	s, err := c.NewStream(network.WithUseTransient(ctx, "identify"))
 	if err != nil {
 		log.Debugw("error opening identify stream", "peer", c.RemotePeer(), "error", err)
 		return err
 	}
+	s.SetDeadline(time.Now().Add(Timeout))
 
 	if err := s.SetProtocol(ID); err != nil {
 		log.Warnf("error setting identify protocol for stream: %s", err)
@@ -439,6 +441,7 @@ func (ids *idService) identifyConn(c network.Conn) error {
 
 // handlePush handles incoming identify push streams
 func (ids *idService) handlePush(s network.Stream) {
+	s.SetDeadline(time.Now().Add(Timeout))
 	ids.handleIdentifyResponse(s, true)
 }
 
@@ -500,8 +503,6 @@ func (ids *idService) handleIdentifyResponse(s network.Stream, isPush bool) erro
 	}
 	defer s.Scope().ReleaseMemory(signedIDSize)
 
-	_ = s.SetReadDeadline(time.Now().Add(StreamReadTimeout))
-
 	c := s.Conn()
 
 	r := pbio.NewDelimitedReader(s, signedIDSize)

p2p/protocol/identify/id_test.go

@@ -804,10 +804,10 @@ func TestLargePushMessage(t *testing.T) {
 }
 
 func TestIdentifyResponseReadTimeout(t *testing.T) {
-	timeout := identify.StreamReadTimeout
-	identify.StreamReadTimeout = 100 * time.Millisecond
+	timeout := identify.Timeout
+	identify.Timeout = 100 * time.Millisecond
 	defer func() {
-		identify.StreamReadTimeout = timeout
+		identify.Timeout = timeout
 	}()
 
 	ctx, cancel := context.WithCancel(context.Background())
@@ -850,10 +850,10 @@ func TestIdentifyResponseReadTimeout(t *testing.T) {
 }
 
 func TestIncomingIDStreamsTimeout(t *testing.T) {
-	timeout := identify.StreamReadTimeout
-	identify.StreamReadTimeout = 100 * time.Millisecond
+	timeout := identify.Timeout
+	identify.Timeout = 100 * time.Millisecond
 	defer func() {
-		identify.StreamReadTimeout = timeout
+		identify.Timeout = timeout
 	}()
 
 	ctx, cancel := context.WithCancel(context.Background())

version.json

@@ -1,3 +1,3 @@
 {
-  "version": "v0.27.6"
+  "version": "v0.27.7"
 }