multi: add custom feature bits to config options

lncfg/protocol_experimental_off.go

@@ -3,6 +3,11 @@
 
 package lncfg
 
+import (
+	"github.com/lightningnetwork/lnd/feature"
+	"github.com/lightningnetwork/lnd/lnwire"
+)
+
 // ExperimentalProtocol is a sub-config that houses any experimental protocol
 // features that also require a build-tag to activate.
 type ExperimentalProtocol struct {
@@ -13,3 +18,8 @@ type ExperimentalProtocol struct {
 func (p ExperimentalProtocol) CustomMessageOverrides() []uint16 {
 	return nil
 }
+
+// CustomFeatures returns a custom set of feature bits to advertise.
+func (p ExperimentalProtocol) CustomFeatures() map[feature.Set][]lnwire.FeatureBit {
+	return map[feature.Set][]lnwire.FeatureBit{}
+}

lncfg/protocol_experimental_on.go

@@ -3,12 +3,23 @@
 
 package lncfg
 
+import (
+	"github.com/lightningnetwork/lnd/feature"
+	"github.com/lightningnetwork/lnd/lnwire"
+)
+
 // ExperimentalProtocol is a sub-config that houses any experimental protocol
 // features that also require a build-tag to activate.
 //
 //nolint:lll
 type ExperimentalProtocol struct {
 	CustomMessage []uint16 `long:"custom-message" description:"allows the custom message apis to send and report messages with the protocol number provided that fall outside of the custom message number range."`
+
+	CustomInit []uint16 `long:"custom-init" description:"custom feature bits to advertise in the node's init message"`
+
+	CustomNodeAnn []uint16 `long:"custom-nodeann" description:"custom feature bits to advertise in the node's announcement message"`
+
+	CustomInvoice []uint16 `long:"custom-invoice" description:"custom feature bits to advertise in the node's invoices"`
 }
 
 // CustomMessageOverrides returns the set of protocol messages that we override
@@ -16,3 +27,25 @@ type ExperimentalProtocol struct {
 func (p ExperimentalProtocol) CustomMessageOverrides() []uint16 {
 	return p.CustomMessage
 }
+
+// CustomFeatures returns a custom set of feature bits to advertise.
+//
+//nolint:lll
+func (p ExperimentalProtocol) CustomFeatures() map[feature.Set][]lnwire.FeatureBit {
+	customFeatures := make(map[feature.Set][]lnwire.FeatureBit)
+
+	setFeatures := func(set feature.Set, bits []uint16) {
+		for _, customFeature := range bits {
+			customFeatures[set] = append(
+				customFeatures[set],
+				lnwire.FeatureBit(customFeature),
+			)
+		}
+	}
+
+	setFeatures(feature.SetInit, p.CustomInit)
+	setFeatures(feature.SetNodeAnn, p.CustomNodeAnn)
+	setFeatures(feature.SetInvoice, p.CustomInvoice)
+
+	return customFeatures
+}