swarm: don't open new streams over transient connections (libp2p#2450)

p2p/net/swarm/swarm.go

@@ -743,3 +743,12 @@ func (c connWithMetrics) Close() error {
 	c.metricsTracer.ClosedConnection(c.dir, time.Since(c.opened), c.ConnState(), c.LocalMultiaddr())
 	return c.CapableConn.Close()
 }
+
+func (c connWithMetrics) Stat() network.ConnStats {
+	if cs, ok := c.CapableConn.(network.ConnStat); ok {
+		return cs.Stat()
+	}
+	return network.ConnStats{}
+}
+
+var _ network.ConnStat = connWithMetrics{}

p2p/test/basichost/basic_host_test.go

@@ -0,0 +1,72 @@
+package basichost
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	"github.com/libp2p/go-libp2p"
+	"github.com/libp2p/go-libp2p/core/network"
+	"github.com/libp2p/go-libp2p/core/peer"
+	"github.com/libp2p/go-libp2p/p2p/protocol/circuitv2/client"
+	"github.com/libp2p/go-libp2p/p2p/protocol/circuitv2/relay"
+	ma "github.com/multiformats/go-multiaddr"
+	"github.com/stretchr/testify/require"
+)
+
+func TestNoStreamOverTransientConnection(t *testing.T) {
+	h1, err := libp2p.New(
+		libp2p.NoListenAddrs,
+		libp2p.EnableRelay(),
+	)
+	require.NoError(t, err)
+
+	h2, err := libp2p.New(
+		libp2p.NoListenAddrs,
+		libp2p.EnableRelay(),
+	)
+	require.NoError(t, err)
+
+	relay1, err := libp2p.New()
+	require.NoError(t, err)
+
+	_, err = relay.New(relay1)
+	require.NoError(t, err)
+
+	relay1info := peer.AddrInfo{
+		ID:    relay1.ID(),
+		Addrs: relay1.Addrs(),
+	}
+	err = h1.Connect(context.Background(), relay1info)
+	require.NoError(t, err)
+
+	err = h2.Connect(context.Background(), relay1info)
+	require.NoError(t, err)
+
+	h2.SetStreamHandler("/testprotocol", func(s network.Stream) {
+		fmt.Println("testprotocol")
+
+		// End the example
+		s.Close()
+	})
+
+	_, err = client.Reserve(context.Background(), h2, relay1info)
+	require.NoError(t, err)
+
+	relayaddr := ma.StringCast("/p2p/" + relay1info.ID.String() + "/p2p-circuit/p2p/" + h2.ID().String())
+
+	h2Info := peer.AddrInfo{
+		ID:    h2.ID(),
+		Addrs: []ma.Multiaddr{relayaddr},
+	}
+	err = h1.Connect(context.Background(), h2Info)
+	require.NoError(t, err)
+
+	ctx := network.WithNoDial(context.Background(), "test")
+	_, err = h1.NewStream(ctx, h2.ID(), "/testprotocol")
+
+	require.ErrorIs(t, err, network.ErrTransientConn)
+
+	_, err = h1.NewStream(network.WithUseTransient(context.Background(), "test"), h2.ID(), "/testprotocol")
+	require.NoError(t, err)
+}