multi: thread anchor client down to wtclient subserver

lnrpc/wtclientrpc/config.go

@@ -19,6 +19,10 @@ type Config struct {
 	// through the watchtower RPC subserver.
 	Client wtclient.Client
 
+	// AnchorClient is the backing watchtower client for anchor channels that
+	// we'll interact through the watchtower RPC subserver.
+	AnchorClient wtclient.Client
+
 	// Resolver is a custom resolver that will be used to resolve watchtower
 	// addresses to ensure we don't leak any information when running over
 	// non-clear networks, e.g. Tor, etc.

rpcserver.go

@@ -619,8 +619,8 @@ func newRPCServer(cfg *Config, s *server, macService *macaroons.Service,
 		cfg, s.cc, cfg.networkDir, macService, atpl, invoiceRegistry,
 		s.htlcSwitch, cfg.ActiveNetParams.Params, s.chanRouter,
 		routerBackend, s.nodeSigner, s.remoteChanDB, s.sweeper, tower,
-		s.towerClient, cfg.net.ResolveTCPAddr, genInvoiceFeatures,
-		rpcsLog,
+		s.towerClient, s.anchorTowerClient, cfg.net.ResolveTCPAddr,
+		genInvoiceFeatures, rpcsLog,
 	)
 	if err != nil {
 		return nil, err

subrpcserver_config.go

@@ -96,6 +96,7 @@ func (s *subRPCServerConfigs) PopulateDependencies(cfg *Config,
 	sweeper *sweep.UtxoSweeper,
 	tower *watchtower.Standalone,
 	towerClient wtclient.Client,
+	anchorTowerClient wtclient.Client,
 	tcpResolver lncfg.TCPResolver,
 	genInvoiceFeatures func() *lnwire.FeatureVector,
 	rpcLogger btclog.Logger) error {
@@ -243,13 +244,16 @@ func (s *subRPCServerConfigs) PopulateDependencies(cfg *Config,
 		case *wtclientrpc.Config:
 			subCfgValue := extractReflectValue(subCfg)
 
-			if towerClient != nil {
+			if towerClient != nil && anchorTowerClient != nil {
 				subCfgValue.FieldByName("Active").Set(
 					reflect.ValueOf(towerClient != nil),
 				)
 				subCfgValue.FieldByName("Client").Set(
 					reflect.ValueOf(towerClient),
 				)
+				subCfgValue.FieldByName("AnchorClient").Set(
+					reflect.ValueOf(anchorTowerClient),
+				)
 			}
 			subCfgValue.FieldByName("Resolver").Set(
 				reflect.ValueOf(tcpResolver),