Add Public Method To Retrieve Discovery Address (#8143)

* add method

* fix

Co-authored-by: Raul Jordan <raul@prysmaticlabs.com>
Co-authored-by: prylabs-bulldozer[bot] <58059840+prylabs-bulldozer[bot]@users.noreply.github.com>

beacon-chain/p2p/discovery.go

@@ -358,7 +358,17 @@ func convertToSingleMultiAddr(node *enode.Node) (ma.Multiaddr, error) {
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get peer id")
 	}
-	return multiAddressBuilderWithID(node.IP().String(), uint(node.TCP()), id)
+	return multiAddressBuilderWithID(node.IP().String(), "tcp", uint(node.TCP()), id)
+}
+
+func convertToUdpMultiAddr(node *enode.Node) (ma.Multiaddr, error) {
+	pubkey := node.Pubkey()
+	assertedKey := convertToInterfacePubkey(pubkey)
+	id, err := peer.IDFromPublicKey(assertedKey)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get peer id")
+	}
+	return multiAddressBuilderWithID(node.IP().String(), "udp", uint(node.UDP()), id)
 }
 
 func peersFromStringAddrs(addrs []string) ([]ma.Multiaddr, error) {

beacon-chain/p2p/discovery_test.go

@@ -9,6 +9,7 @@ import (
 	"os"
 	"path"
 	"strconv"
+	"strings"
 	"testing"
 	"time"
 
@@ -264,6 +265,27 @@ func TestInboundPeerLimit(t *testing.T) {
 	require.Equal(t, true, s.isPeerAtLimit(true), "not at limit for inbound peers")
 }
 
+func TestUDPMultiAddress(t *testing.T) {
+	port := 6500
+	ipAddr, pkey := createAddrAndPrivKey(t)
+	genesisTime := time.Now()
+	genesisValidatorsRoot := make([]byte, 32)
+	s := &Service{
+		cfg:                   &Config{UDPPort: uint(port)},
+		genesisTime:           genesisTime,
+		genesisValidatorsRoot: genesisValidatorsRoot,
+	}
+	listener, err := s.createListener(ipAddr, pkey)
+	require.NoError(t, err)
+	defer listener.Close()
+	s.dv5Listener = listener
+
+	multiAddress, err := s.DiscoveryAddress()
+	require.NoError(t, err)
+	assert.Equal(t, true, strings.Contains(multiAddress.String(), fmt.Sprintf("%d", port)))
+	assert.Equal(t, true, strings.Contains(multiAddress.String(), "udp"))
+}
+
 // addPeer is a helper to add a peer with a given connection state)
 func addPeer(t *testing.T, p *peers.Status, state peerdata.PeerConnectionState) peer.ID {
 	// Set up some peers with different states

beacon-chain/p2p/interfaces.go

@@ -10,6 +10,7 @@ import (
 	"github.com/libp2p/go-libp2p-core/network"
 	"github.com/libp2p/go-libp2p-core/peer"
 	pubsub "github.com/libp2p/go-libp2p-pubsub"
+	"github.com/multiformats/go-multiaddr"
 	ethpb "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
 	"github.com/prysmaticlabs/prysm/beacon-chain/p2p/encoder"
 	"github.com/prysmaticlabs/prysm/beacon-chain/p2p/peers"
@@ -73,6 +74,7 @@ type PeerManager interface {
 	PeerID() peer.ID
 	Host() host.Host
 	ENR() *enr.Record
+	DiscoveryAddress() (multiaddr.Multiaddr, error)
 	RefreshENR()
 	FindPeersWithSubnet(ctx context.Context, topic string, index, threshold uint64) (bool, error)
 	AddPingMethod(reqFunc func(ctx context.Context, id peer.ID) error)

beacon-chain/p2p/options.go

@@ -85,7 +85,7 @@ func multiAddressBuilder(ipAddr string, port uint) (ma.Multiaddr, error) {
 	return ma.NewMultiaddr(fmt.Sprintf("/ip6/%s/tcp/%d", ipAddr, port))
 }
 
-func multiAddressBuilderWithID(ipAddr string, port uint, id peer.ID) (ma.Multiaddr, error) {
+func multiAddressBuilderWithID(ipAddr, protocol string, port uint, id peer.ID) (ma.Multiaddr, error) {
 	parsedIP := net.ParseIP(ipAddr)
 	if parsedIP.To4() == nil && parsedIP.To16() == nil {
 		return nil, errors.Errorf("invalid ip address provided: %s", ipAddr)
@@ -94,9 +94,9 @@ func multiAddressBuilderWithID(ipAddr string, port uint, id peer.ID) (ma.Multiad
 		return nil, errors.New("empty peer id given")
 	}
 	if parsedIP.To4() != nil {
-		return ma.NewMultiaddr(fmt.Sprintf("/ip4/%s/tcp/%d/p2p/%s", ipAddr, port, id.String()))
+		return ma.NewMultiaddr(fmt.Sprintf("/ip4/%s/%s/%d/p2p/%s", ipAddr, protocol, port, id.String()))
 	}
-	return ma.NewMultiaddr(fmt.Sprintf("/ip6/%s/tcp/%d/p2p/%s", ipAddr, port, id.String()))
+	return ma.NewMultiaddr(fmt.Sprintf("/ip6/%s/%s/%d/p2p/%s", ipAddr, protocol, port, id.String()))
 }
 
 // Adds a private key to the libp2p option if the option was provided.

beacon-chain/p2p/service.go

@@ -327,6 +327,15 @@ func (s *Service) ENR() *enr.Record {
 	return s.dv5Listener.Self().Record()
 }
 
+// DiscoveryAddress is the multiaddress representation of
+// our enr.
+func (s *Service) DiscoveryAddress() (multiaddr.Multiaddr, error) {
+	if s.dv5Listener == nil {
+		return nil, nil
+	}
+	return convertToUdpMultiAddr(s.dv5Listener.Self())
+}
+
 // Metadata returns a copy of the peer's metadata.
 func (s *Service) Metadata() *pb.MetaData {
 	return proto.Clone(s.metaData).(*pb.MetaData)

beacon-chain/p2p/testing/fuzz_p2p.go

@@ -56,6 +56,11 @@ func (p *FakeP2P) ENR() *enr.Record {
 	return new(enr.Record)
 }
 
+// DiscoveryAddress -- fake
+func (p *FakeP2P) DiscoveryAddress() (multiaddr.Multiaddr, error) {
+	return nil, nil
+}
+
 // FindPeersWithSubnet mocks the p2p func.
 func (p *FakeP2P) FindPeersWithSubnet(_ context.Context, _ string, _, _ uint64) (bool, error) {
 	return false, nil

beacon-chain/p2p/testing/mock_peermanager.go

@@ -6,6 +6,7 @@ import (
 	"github.com/ethereum/go-ethereum/p2p/enr"
 	"github.com/libp2p/go-libp2p-core/host"
 	"github.com/libp2p/go-libp2p-core/peer"
+	"github.com/multiformats/go-multiaddr"
 )
 
 // MockPeerManager is mock of the PeerManager interface.
@@ -35,6 +36,11 @@ func (m MockPeerManager) ENR() *enr.Record {
 	return m.Enr
 }
 
+// DiscoveryAddress .
+func (m MockPeerManager) DiscoveryAddress() (multiaddr.Multiaddr, error) {
+	return nil, nil
+}
+
 // RefreshENR .
 func (m MockPeerManager) RefreshENR() {}
 

beacon-chain/p2p/testing/p2p.go

@@ -236,6 +236,11 @@ func (p *TestP2P) ENR() *enr.Record {
 	return new(enr.Record)
 }
 
+// DiscoveryAddress --
+func (p *TestP2P) DiscoveryAddress() (multiaddr.Multiaddr, error) {
+	return nil, nil
+}
+
 // AddConnectionHandler handles the connection with a newly connected peer.
 func (p *TestP2P) AddConnectionHandler(f, _ func(ctx context.Context, id peer.ID) error) {
 	p.BHost.Network().Notify(&network.NotifyBundle{