multi: add experimental endorsement feature bit and disable option

feature/default_sets.go

@@ -96,4 +96,7 @@ var defaultSetDesc = setDesc{
 		SetInit:    {}, // I
 		SetNodeAnn: {}, // N
 	},
+	lnwire.ExperimentalEndorsementOptional: {
+		SetNodeAnn: {}, // N
+	},
 }

feature/manager.go

@@ -66,6 +66,10 @@ type Config struct {
 	// NoTaprootOverlay unsets the taproot overlay channel feature bits.
 	NoTaprootOverlay bool
 
+	// NoExperimentalEndorsement unsets any bits that signal support for
+	// forwarding experimental endorsement.
+	NoExperimentalEndorsement bool
+
 	// CustomFeatures is a set of custom features to advertise in each
 	// set.
 	CustomFeatures map[Set][]lnwire.FeatureBit
@@ -199,6 +203,12 @@ func newManager(cfg Config, desc setDesc) (*Manager, error) {
 			raw.Unset(lnwire.SimpleTaprootOverlayChansOptional)
 			raw.Unset(lnwire.SimpleTaprootOverlayChansRequired)
 		}
+
+		if cfg.NoExperimentalEndorsement {
+			raw.Unset(lnwire.ExperimentalEndorsementOptional)
+			raw.Unset(lnwire.ExperimentalEndorsementRequired)
+		}
+
 		for _, custom := range cfg.CustomFeatures[set] {
 			if custom > set.Maximum() {
 				return nil, fmt.Errorf("feature bit: %v "+

lncfg/protocol.go

@@ -67,6 +67,9 @@ type ProtocolOptions struct {
 	// NoRouteBlindingOption disables forwarding of payments in blinded routes.
 	NoRouteBlindingOption bool `long:"no-route-blinding" description:"do not forward payments that are a part of a blinded route"`
 
+	// NoExperimentalEndorsementOption disables experimental endorsement.
+	NoExperimentalEndorsementOption bool `long:"no-experimental-endorsement" description:"do not forward experimental endorsement signals"`
+
 	// CustomMessage allows the custom message APIs to handle messages with
 	// the provided protocol numbers, which fall outside the custom message
 	// number range.
@@ -132,6 +135,12 @@ func (l *ProtocolOptions) NoRouteBlinding() bool {
 	return l.NoRouteBlindingOption
 }
 
+// NoExperimentalEndorsement returns true if experimental endorsement should
+// be disabled.
+func (l *ProtocolOptions) NoExperimentalEndorsement() bool {
+	return l.NoExperimentalEndorsementOption
+}
+
 // CustomMessageOverrides returns the set of protocol messages that we override
 // to allow custom handling.
 func (p ProtocolOptions) CustomMessageOverrides() []uint16 {

lncfg/protocol_integration.go

@@ -70,6 +70,9 @@ type ProtocolOptions struct {
 	// NoRouteBlindingOption disables forwarding of payments in blinded routes.
 	NoRouteBlindingOption bool `long:"no-route-blinding" description:"do not forward payments that are a part of a blinded route"`
 
+	// NoExperimentalEndorsementOption disables experimental endorsement.
+	NoExperimentalEndorsementOption bool `long:"no-experimental-endorsement" description:"do not forward experimental endorsement signals"`
+
 	// CustomMessage allows the custom message APIs to handle messages with
 	// the provided protocol numbers, which fall outside the custom message
 	// number range.
@@ -127,6 +130,12 @@ func (l *ProtocolOptions) NoRouteBlinding() bool {
 	return l.NoRouteBlindingOption
 }
 
+// NoExperimentalEndorsement returns true if experimental endorsement should
+// be disabled.
+func (l *ProtocolOptions) NoExperimentalEndorsement() bool {
+	return l.NoExperimentalEndorsementOption
+}
+
 // CustomMessageOverrides returns the set of protocol messages that we override
 // to allow custom handling.
 func (l ProtocolOptions) CustomMessageOverrides() []uint16 {

lnwire/features.go

@@ -263,6 +263,14 @@ const (
 	// being finalized.
 	SimpleTaprootChannelsOptionalStaging = 181
 
+	// ExperimentalEndorsementRequired is a required feature bit that
+	// indicates that the node will relay experimental endorsement signals.
+	ExperimentalEndorsementRequired FeatureBit = 260
+
+	// ExperimentalEndorsementOptional is an optional feature bit that
+	// indicates that the node will relay experimental endorsement signals.
+	ExperimentalEndorsementOptional FeatureBit = 261
+
 	// Bolt11BlindedPathsRequired is a required feature bit that indicates
 	// that the node is able to understand the blinded path tagged field in
 	// a BOLT 11 invoice.
@@ -349,6 +357,8 @@ var Features = map[FeatureBit]string{
 	SimpleTaprootChannelsOptionalStaging: "simple-taproot-chans-x",
 	SimpleTaprootOverlayChansOptional:    "taproot-overlay-chans",
 	SimpleTaprootOverlayChansRequired:    "taproot-overlay-chans",
+	ExperimentalEndorsementRequired:      "endorsement-x",
+	ExperimentalEndorsementOptional:      "endorsement-x",
 	Bolt11BlindedPathsOptional:           "bolt-11-blinded-paths",
 	Bolt11BlindedPathsRequired:           "bolt-11-blinded-paths",
 }

rpcserver.go

@@ -760,6 +760,10 @@ func (r *rpcServer) addDeps(s *server, macService *macaroons.Service,
 			return nil
 		},
 		ShouldSetExpEndorsement: func() bool {
+			if s.cfg.ProtocolOptions.NoExperimentalEndorsement() {
+				return false
+			}
+
 			return clock.NewDefaultClock().Now().Before(
 				EndorsementExperimentEnd,
 			)

sample-lnd.conf

@@ -1399,6 +1399,9 @@
 ; Set to disable blinded route forwarding.
 ; protocol.no-route-blinding=false
 
+; Set to disable experimental endorsement signaling.
+; protocol.no-experimental-endorsement=false
+
 ; Set to handle messages of a particular type that falls outside of the
 ; custom message number range (i.e. 513 is onion messages). Note that you can
 ; set this option as many times as you want to support more than one custom

server.go

@@ -573,19 +573,20 @@ func newServer(cfg *Config, listenAddrs []net.Addr,
 
 	//nolint:lll
 	featureMgr, err := feature.NewManager(feature.Config{
-		NoTLVOnion:               cfg.ProtocolOptions.LegacyOnion(),
-		NoStaticRemoteKey:        cfg.ProtocolOptions.NoStaticRemoteKey(),
-		NoAnchors:                cfg.ProtocolOptions.NoAnchorCommitments(),
-		NoWumbo:                  !cfg.ProtocolOptions.Wumbo(),
-		NoScriptEnforcementLease: cfg.ProtocolOptions.NoScriptEnforcementLease(),
-		NoKeysend:                !cfg.AcceptKeySend,
-		NoOptionScidAlias:        !cfg.ProtocolOptions.ScidAlias(),
-		NoZeroConf:               !cfg.ProtocolOptions.ZeroConf(),
-		NoAnySegwit:              cfg.ProtocolOptions.NoAnySegwit(),
-		CustomFeatures:           cfg.ProtocolOptions.CustomFeatures(),
-		NoTaprootChans:           !cfg.ProtocolOptions.TaprootChans,
-		NoTaprootOverlay:         !cfg.ProtocolOptions.TaprootOverlayChans,
-		NoRouteBlinding:          cfg.ProtocolOptions.NoRouteBlinding(),
+		NoTLVOnion:                cfg.ProtocolOptions.LegacyOnion(),
+		NoStaticRemoteKey:         cfg.ProtocolOptions.NoStaticRemoteKey(),
+		NoAnchors:                 cfg.ProtocolOptions.NoAnchorCommitments(),
+		NoWumbo:                   !cfg.ProtocolOptions.Wumbo(),
+		NoScriptEnforcementLease:  cfg.ProtocolOptions.NoScriptEnforcementLease(),
+		NoKeysend:                 !cfg.AcceptKeySend,
+		NoOptionScidAlias:         !cfg.ProtocolOptions.ScidAlias(),
+		NoZeroConf:                !cfg.ProtocolOptions.ZeroConf(),
+		NoAnySegwit:               cfg.ProtocolOptions.NoAnySegwit(),
+		CustomFeatures:            cfg.ProtocolOptions.CustomFeatures(),
+		NoTaprootChans:            !cfg.ProtocolOptions.TaprootChans,
+		NoTaprootOverlay:          !cfg.ProtocolOptions.TaprootOverlayChans,
+		NoRouteBlinding:           cfg.ProtocolOptions.NoRouteBlinding(),
+		NoExperimentalEndorsement: cfg.ProtocolOptions.NoExperimentalEndorsement(),
 	})
 	if err != nil {
 		return nil, err
@@ -4221,6 +4222,10 @@ func (s *server) peerConnected(conn net.Conn, connReq *connmgr.ConnReq,
 		AuxChanCloser:          s.implCfg.AuxChanCloser,
 		AuxResolver:            s.implCfg.AuxContractResolver,
 		ShouldFwdExpEndorsement: func() bool {
+			if s.cfg.ProtocolOptions.NoExperimentalEndorsement() {
+				return false
+			}
+
 			return clock.NewDefaultClock().Now().Before(
 				EndorsementExperimentEnd,
 			)