routed host: search for new multi addresses upon connect failure

core/peerstore/peerstore.go

@@ -25,11 +25,6 @@ var (
 	// TempAddrTTL is the ttl used for a short lived address.
 	TempAddrTTL = time.Minute * 2
 
-	// ProviderAddrTTL is the TTL of an address we've received from a provider.
-	// This is also a temporary address, but lasts longer. After this expires,
-	// the records we return will require an extra lookup.
-	ProviderAddrTTL = time.Minute * 30
-
 	// RecentlyConnectedAddrTTL is used when we recently connected to a peer.
 	// It means that we are reasonably certain of the peer's address.
 	RecentlyConnectedAddrTTL = time.Minute * 30

p2p/host/routed/routed.go

@@ -107,7 +107,39 @@ func (rh *RoutedHost) Connect(ctx context.Context, pi peer.AddrInfo) error {
 
 	// if we're here, we got some addrs. let's use our wrapped host to connect.
 	pi.Addrs = addrs
-	return rh.host.Connect(ctx, pi)
+	err := rh.host.Connect(ctx, pi)
+	if err != nil {
+		// We couldn't connect. Let's check if we have the most
+		// up-to-date addresses for the given peer. If there
+		// are addresses we didn't know about previously, we
+		// try to connect again.
+		newAddrs, addrErr := rh.findPeerAddrs(ctx, pi.ID)
+		if addrErr != nil {
+			return err // return outer error
+		}
+
+		// Build lookup map
+		lookup := make(map[ma.Multiaddr]struct{}, len(addrs))
+		for _, addr := range addrs {
+			lookup[addr] = struct{}{}
+		}
+
+		// if there's any address that's not in the previous set
+		// of addresses, try to connect again. If all addresses
+		// where known previously we return the original error.
+		for _, newAddr := range newAddrs {
+			if _, found := lookup[newAddr]; found {
+				continue
+			}
+
+			pi.Addrs = newAddrs
+			return rh.host.Connect(ctx, pi)
+		}
+
+		return err
+	}
+
+	return nil
 }
 
 func (rh *RoutedHost) findPeerAddrs(ctx context.Context, id peer.ID) ([]ma.Multiaddr, error) {

p2p/host/routed/routed_test.go

@@ -0,0 +1,73 @@
+package routedhost
+
+import (
+	"context"
+	"testing"
+
+	"github.com/libp2p/go-libp2p/core/peer"
+	basic "github.com/libp2p/go-libp2p/p2p/host/basic"
+	swarmt "github.com/libp2p/go-libp2p/p2p/net/swarm/testing"
+	ma "github.com/multiformats/go-multiaddr"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+var _ Routing = (*mockRouting)(nil)
+
+type mockRouting struct {
+	callCount  int
+	findPeerFn func(ctx context.Context, id peer.ID) (peer.AddrInfo, error)
+}
+
+func (m *mockRouting) FindPeer(ctx context.Context, pid peer.ID) (peer.AddrInfo, error) {
+	m.callCount += 1
+	return m.findPeerFn(ctx, pid)
+}
+
+func TestRoutedHost_Connect_obsoleteAddresses(t *testing.T) {
+	ctx := context.Background()
+
+	h1, err := basic.NewHost(swarmt.GenSwarm(t), nil)
+	require.NoError(t, err)
+	defer h1.Close()
+
+	h2, err := basic.NewHost(swarmt.GenSwarm(t), nil)
+	require.NoError(t, err)
+	defer h2.Close()
+
+	// construct a wrong multi address for host 2, so that
+	// the initial connection attempt will fail
+	// (we have obsolete, old multi address information)
+	maddr, err := ma.NewMultiaddr("/ip4/127.0.0.1/tcp/1234")
+	require.NoError(t, err)
+
+	// assemble the AddrInfo struct to use for the connection attempt
+	pi := peer.AddrInfo{
+		ID:    h2.ID(),
+		Addrs: []ma.Multiaddr{maddr},
+	}
+
+	// Build mock routing module and replace the FindPeer function.
+	// Now, that function will return the correct multi addresses for host 2
+	// (we have fetched the most up-to-date data from the DHT)
+	mr := &mockRouting{
+		findPeerFn: func(ctx context.Context, pi peer.ID) (peer.AddrInfo, error) {
+			return peer.AddrInfo{
+				ID:    h2.ID(),
+				Addrs: h2.Addrs(),
+			}, nil
+		},
+	}
+
+	// Build routed host
+	rh := Wrap(h1, mr)
+
+	// Try to connect
+	err = rh.Connect(ctx, pi)
+
+	// Connection establishment should have worked without an error
+	assert.NoError(t, err)
+
+	// The mocked FindPeer function should have been called
+	assert.Equal(t, 1, mr.callCount)
+}