[2/2] discovery+lnwire: add support for DNS host name in NodeAnnouncement msg using a new external-dns-address config field

chanbackup/backup_test.go

@@ -161,6 +161,7 @@ func TestFetchStaticChanBackups(t *testing.T) {
 	chanSource.addAddrsForNode(randomChan2.IdentityPub, []net.Addr{addr2})
 	chanSource.addAddrsForNode(randomChan2.IdentityPub, []net.Addr{addr3})
 	chanSource.addAddrsForNode(randomChan2.IdentityPub, []net.Addr{addr4})
+	chanSource.addAddrsForNode(randomChan2.IdentityPub, []net.Addr{addr5})
 
 	// With the channel source populated, we'll now attempt to create a set
 	// of backups for all the channels. This should succeed, as all items

chanbackup/multi_test.go

@@ -23,7 +23,7 @@ func TestMultiPackUnpack(t *testing.T) {
 		}
 
 		single := NewSingle(
-			channel, []net.Addr{addr1, addr2, addr3, addr4},
+			channel, []net.Addr{addr1, addr2, addr3, addr4, addr5},
 		)
 
 		originalSingles = append(originalSingles, single)

chanbackup/single_test.go

@@ -41,7 +41,11 @@ var (
 		OnionService: "3g2upl4pq6kufc4m.onion",
 		Port:         9735,
 	}
-	addr4 = &lnwire.OpaqueAddrs{
+	addr4 = &lnwire.DNSAddress{
+		Hostname: "example.com",
+		Port:     8080,
+	}
+	addr5 = &lnwire.OpaqueAddrs{
 		// The first byte must be an address type we are not yet aware
 		// of for it to be a valid OpaqueAddrs.
 		Payload: []byte{math.MaxUint8, 1, 2, 3, 4},
@@ -320,7 +324,7 @@ func TestSinglePackUnpack(t *testing.T) {
 	require.NoError(t, err, "unable to gen open channel")
 
 	singleChanBackup := NewSingle(
-		channel, []net.Addr{addr1, addr2, addr3, addr4},
+		channel, []net.Addr{addr1, addr2, addr3, addr4, addr5},
 	)
 
 	keyRing := &lnencrypt.MockKeyRing{}
@@ -647,7 +651,7 @@ func TestSingleUnconfirmedChannel(t *testing.T) {
 	channel.FundingBroadcastHeight = fundingBroadcastHeight
 
 	singleChanBackup := NewSingle(
-		channel, []net.Addr{addr1, addr2, addr3, addr4},
+		channel, []net.Addr{addr1, addr2, addr3, addr4, addr5},
 	)
 	keyRing := &lnencrypt.MockKeyRing{}
 

config.go

@@ -336,26 +336,28 @@ type Config struct {
 	// loadConfig function. We need to expose the 'raw' strings so the
 	// command line library can access them.
 	// Only the parsed net.Addrs should be used!
-	RawRPCListeners   []string `long:"rpclisten" description:"Add an interface/port/socket to listen for RPC connections"`
-	RawRESTListeners  []string `long:"restlisten" description:"Add an interface/port/socket to listen for REST connections"`
-	RawListeners      []string `long:"listen" description:"Add an interface/port to listen for peer connections"`
-	RawExternalIPs    []string `long:"externalip" description:"Add an ip:port to the list of local addresses we claim to listen on to peers. If a port is not specified, the default (9735) will be used regardless of other parameters"`
-	ExternalHosts     []string `long:"externalhosts" description:"Add a hostname:port that should be periodically resolved to announce IPs for. If a port is not specified, the default (9735) will be used."`
-	RPCListeners      []net.Addr
-	RESTListeners     []net.Addr
-	RestCORS          []string `long:"restcors" description:"Add an ip:port/hostname to allow cross origin access from. To allow all origins, set as \"*\"."`
-	Listeners         []net.Addr
-	ExternalIPs       []net.Addr
-	DisableListen     bool          `long:"nolisten" description:"Disable listening for incoming peer connections"`
-	DisableRest       bool          `long:"norest" description:"Disable REST API"`
-	DisableRestTLS    bool          `long:"no-rest-tls" description:"Disable TLS for REST connections"`
-	WSPingInterval    time.Duration `long:"ws-ping-interval" description:"The ping interval for REST based WebSocket connections, set to 0 to disable sending ping messages from the server side"`
-	WSPongWait        time.Duration `long:"ws-pong-wait" description:"The time we wait for a pong response message on REST based WebSocket connections before the connection is closed as inactive"`
-	NAT               bool          `long:"nat" description:"Toggle NAT traversal support (using either UPnP or NAT-PMP) to automatically advertise your external IP address to the network -- NOTE this does not support devices behind multiple NATs"`
-	AddPeers          []string      `long:"addpeer" description:"Specify peers to connect to first"`
-	MinBackoff        time.Duration `long:"minbackoff" description:"Shortest backoff when reconnecting to persistent peers. Valid time units are {s, m, h}."`
-	MaxBackoff        time.Duration `long:"maxbackoff" description:"Longest backoff when reconnecting to persistent peers. Valid time units are {s, m, h}."`
-	ConnectionTimeout time.Duration `long:"connectiontimeout" description:"The timeout value for network connections. Valid time units are {ms, s, m, h}."`
+	RawRPCListeners       []string `long:"rpclisten" description:"Add an interface/port/socket to listen for RPC connections"`
+	RawRESTListeners      []string `long:"restlisten" description:"Add an interface/port/socket to listen for REST connections"`
+	RawListeners          []string `long:"listen" description:"Add an interface/port to listen for peer connections"`
+	RawExternalIPs        []string `long:"externalip" description:"Add an ip:port to the list of local addresses we claim to listen on to peers. If a port is not specified, the default (9735) will be used regardless of other parameters"`
+	RawExternalDNSAddress string   `long:"external-dns-address" description:"Specify a DNS hostname for the node's external address. If no port is provided, the default (9735) is used."`
+	ExternalHosts         []string `long:"externalhosts" description:"Add a hostname:port that should be periodically resolved to announce IPs for. If a port is not specified, the default (9735) will be used."`
+	RPCListeners          []net.Addr
+	RESTListeners         []net.Addr
+	RestCORS              []string `long:"restcors" description:"Add an ip:port/hostname to allow cross origin access from. To allow all origins, set as \"*\"."`
+	Listeners             []net.Addr
+	ExternalIPs           []net.Addr
+	ExternalDNSAddress    *lnwire.DNSAddress
+	DisableListen         bool          `long:"nolisten" description:"Disable listening for incoming peer connections"`
+	DisableRest           bool          `long:"norest" description:"Disable REST API"`
+	DisableRestTLS        bool          `long:"no-rest-tls" description:"Disable TLS for REST connections"`
+	WSPingInterval        time.Duration `long:"ws-ping-interval" description:"The ping interval for REST based WebSocket connections, set to 0 to disable sending ping messages from the server side"`
+	WSPongWait            time.Duration `long:"ws-pong-wait" description:"The time we wait for a pong response message on REST based WebSocket connections before the connection is closed as inactive"`
+	NAT                   bool          `long:"nat" description:"Toggle NAT traversal support (using either UPnP or NAT-PMP) to automatically advertise your external IP address to the network -- NOTE this does not support devices behind multiple NATs"`
+	AddPeers              []string      `long:"addpeer" description:"Specify peers to connect to first"`
+	MinBackoff            time.Duration `long:"minbackoff" description:"Shortest backoff when reconnecting to persistent peers. Valid time units are {s, m, h}."`
+	MaxBackoff            time.Duration `long:"maxbackoff" description:"Longest backoff when reconnecting to persistent peers. Valid time units are {s, m, h}."`
+	ConnectionTimeout     time.Duration `long:"connectiontimeout" description:"The timeout value for network connections. Valid time units are {ms, s, m, h}."`
 
 	DebugLevel string `short:"d" long:"debuglevel" description:"Logging level for all subsystems {trace, debug, info, warn, error, critical} -- You may also specify <global-level>,<subsystem>=<level>,<subsystem2>=<level>,... to set the log level for individual subsystems -- Use show to list available subsystems"`
 
@@ -1592,6 +1594,7 @@ func ValidateConfig(cfg Config, interceptor signal.Interceptor, fileParser,
 		ltndLog.Infof("Listening on the p2p interface is disabled!")
 		cfg.Listeners = nil
 		cfg.ExternalIPs = nil
+		cfg.ExternalDNSAddress = nil
 	} else {
 
 		// Add default port to all listener addresses if needed and remove
@@ -1615,6 +1618,18 @@ func ValidateConfig(cfg Config, interceptor signal.Interceptor, fileParser,
 			return nil, err
 		}
 
+		// Parse the external DNS address if provided.
+		if cfg.RawExternalDNSAddress != "" {
+			addr, err := parseDNSAddr(
+				cfg.RawExternalDNSAddress, cfg.net,
+			)
+			if err != nil {
+				return nil, err
+			}
+
+			cfg.ExternalDNSAddress = addr
+		}
+
 		// For the p2p port it makes no sense to listen to an Unix socket.
 		// Also, we would need to refactor the brontide listener to support
 		// that.

discovery/chan_series.go

@@ -192,6 +192,13 @@ func (c *ChanSeries) UpdatesInHorizon(chain chainhash.Hash,
 			return nil, err
 		}
 
+		if err := netann.ValidateNodeAnnFields(nodeUpdate); err != nil {
+			log.Debugf("Skipping forwarding invalid node "+
+				"announcement %x: %v", nodeAnn.PubKeyBytes, err)
+
+			continue
+		}
+
 		updates = append(updates, nodeUpdate)
 	}
 
@@ -243,6 +250,7 @@ func (c *ChanSeries) FilterChannelRange(_ chainhash.Hash, startHeight,
 // to reply to a QueryShortChanIDs message sent by a remote peer. The response
 // will contain a unique set of ChannelAnnouncements, the latest ChannelUpdate
 // for each of the announcements, and a unique set of NodeAnnouncements.
+// Invalid node announcements are skipped and logged for debugging purposes.
 //
 // NOTE: This is part of the ChannelGraphTimeSeries interface.
 func (c *ChanSeries) FetchChanAnns(chain chainhash.Hash,
@@ -296,8 +304,15 @@ func (c *ChanSeries) FetchChanAnns(chain chainhash.Hash,
 					return nil, err
 				}
 
-				chanAnns = append(chanAnns, nodeAnn)
-				nodePubsSent[nodePub] = struct{}{}
+				err = netann.ValidateNodeAnnFields(nodeAnn)
+				if err != nil {
+					log.Debugf("Skipping forwarding "+
+						"invalid node announcement "+
+						"%x: %v", nodeAnn.NodeID, err)
+				} else {
+					chanAnns = append(chanAnns, nodeAnn)
+					nodePubsSent[nodePub] = struct{}{}
+				}
 			}
 		}
 		if edge2 != nil {
@@ -315,8 +330,15 @@ func (c *ChanSeries) FetchChanAnns(chain chainhash.Hash,
 					return nil, err
 				}
 
-				chanAnns = append(chanAnns, nodeAnn)
-				nodePubsSent[nodePub] = struct{}{}
+				err = netann.ValidateNodeAnnFields(nodeAnn)
+				if err != nil {
+					log.Debugf("Skipping forwarding "+
+						"invalid node announcement "+
+						"%x: %v", nodeAnn.NodeID, err)
+				} else {
+					chanAnns = append(chanAnns, nodeAnn)
+					nodePubsSent[nodePub] = struct{}{}
+				}
 			}
 		}
 	}

discovery/gossiper.go

@@ -2220,7 +2220,9 @@ func (d *AuthenticatedGossiper) processZombieUpdate(_ context.Context,
 }
 
 // fetchNodeAnn fetches the latest signed node announcement from our point of
-// view for the node with the given public key.
+// view for the node with the given public key. It also validates the node
+// announcement fields and returns an error if they are invalid to prevent
+// forwarding invalid node announcements to our peers.
 func (d *AuthenticatedGossiper) fetchNodeAnn(ctx context.Context,
 	pubKey [33]byte) (*lnwire.NodeAnnouncement, error) {
 
@@ -2229,7 +2231,12 @@ func (d *AuthenticatedGossiper) fetchNodeAnn(ctx context.Context,
 		return nil, err
 	}
 
-	return node.NodeAnnouncement(true)
+	nodeAnn, err := node.NodeAnnouncement(true)
+	if err != nil {
+		return nil, err
+	}
+
+	return nodeAnn, netann.ValidateNodeAnnFields(nodeAnn)
 }
 
 // isMsgStale determines whether a message retrieved from the backing

docs/release-notes/release-notes-0.20.0.md

@@ -198,6 +198,14 @@ reader of a payment request.
 * [Require invoices to include a payment address or blinded paths](https://github.com/lightningnetwork/lnd/pull/9752) 
   to comply with updated BOLT 11 specifications before sending payments.
 
+* [Support DNS address in
+  node announcement msg](https://github.com/lightningnetwork/lnd/pull/10159):
+  This update allows users to announce their LND node using a DNS address in
+  the node announcement message, by configuring `external-dns-address` field in
+  the LND config file.
+  **Note:** According to BOLT 07, only one DNS address may be announced per
+  node.
+
 ## Testing
 
 * Previously, automatic peer bootstrapping was disabled for simnet, signet and

graph/db/addr.go

@@ -31,8 +31,36 @@ const (
 	// opaqueAddrs denotes an address (or a set of addresses) that LND was
 	// not able to parse since LND is not yet aware of the address type.
 	opaqueAddrs addressType = 4
+
+	// dnsAddr denotes a DNS address type.
+	dnsAddr addressType = 5
 )
 
+// encodeDNSAddr encodes a DNS address.
+func encodeDNSAddr(w io.Writer, addr *lnwire.DNSAddress) error {
+	if _, err := w.Write([]byte{byte(dnsAddr)}); err != nil {
+		return err
+	}
+
+	// Write the length of the hostname.
+	hostLen := len(addr.Hostname)
+	if _, err := w.Write([]byte{byte(hostLen)}); err != nil {
+		return err
+	}
+
+	if _, err := w.Write([]byte(addr.Hostname)); err != nil {
+		return err
+	}
+
+	var port [2]byte
+	byteOrder.PutUint16(port[:], addr.Port)
+	if _, err := w.Write(port[:]); err != nil {
+		return err
+	}
+
+	return nil
+}
+
 // encodeTCPAddr serializes a TCP address into its compact raw bytes
 // representation.
 func encodeTCPAddr(w io.Writer, addr *net.TCPAddr) error {
@@ -230,6 +258,30 @@ func DeserializeAddr(r io.Reader) (net.Addr, error) {
 			Port:         port,
 		}
 
+	case dnsAddr:
+		// Read the length of the hostname.
+		var hostLen [1]byte
+		if _, err := r.Read(hostLen[:]); err != nil {
+			return nil, err
+		}
+
+		// Read the hostname.
+		hostname := make([]byte, hostLen[0])
+		if _, err := r.Read(hostname); err != nil {
+			return nil, err
+		}
+
+		// Read the port.
+		var port [2]byte
+		if _, err := r.Read(port[:]); err != nil {
+			return nil, err
+		}
+
+		address = &lnwire.DNSAddress{
+			Hostname: string(hostname),
+			Port:     binary.BigEndian.Uint16(port[:]),
+		}
+
 	case opaqueAddrs:
 		// Read the length of the payload.
 		var l [2]byte
@@ -264,6 +316,8 @@ func SerializeAddr(w io.Writer, address net.Addr) error {
 		return encodeOnionAddr(w, addr)
 	case *lnwire.OpaqueAddrs:
 		return encodeOpaqueAddrs(w, addr)
+	case *lnwire.DNSAddress:
+		return encodeDNSAddr(w, addr)
 	default:
 		return ErrUnknownAddressType
 	}