features: define temporary AMP feature bits 30/31

feature/default_sets.go

@@ -51,4 +51,9 @@ var defaultSetDesc = setDesc{
 		SetInit:    {}, // I
 		SetNodeAnn: {}, // N
 	},
+	lnwire.AMPOptional: {
+		SetInit:    {}, // I
+		SetNodeAnn: {}, // N
+		SetInvoice: {}, // 9
+	},
 }

feature/deps.go

@@ -58,6 +58,9 @@ var deps = depDesc{
 	lnwire.AnchorsOptional: {
 		lnwire.StaticRemoteKeyOptional: {},
 	},
+	lnwire.AMPOptional: {
+		lnwire.PaymentAddrOptional: {},
+	},
 }
 
 // ValidateDeps asserts that a feature vector sets all features and their

feature/manager.go

@@ -77,6 +77,8 @@ func newManager(cfg Config, desc setDesc) (*Manager, error) {
 			raw.Unset(lnwire.PaymentAddrRequired)
 			raw.Unset(lnwire.MPPOptional)
 			raw.Unset(lnwire.MPPRequired)
+			raw.Unset(lnwire.AMPOptional)
+			raw.Unset(lnwire.AMPRequired)
 		}
 		if cfg.NoStaticRemoteKey {
 			raw.Unset(lnwire.StaticRemoteKeyOptional)

lnwire/features.go

@@ -129,6 +129,16 @@ const (
 	// transactions, which also imply anchor commitments.
 	AnchorsZeroFeeHtlcTxOptional FeatureBit = 23
 
+	// AMPRequired is a required feature bit that signals that the receiver
+	// of a payment supports accepts spontaneous payments, i.e.
+	// sender-generated preimages according to BOLT XX.
+	AMPRequired FeatureBit = 30
+
+	// AMPOptional is an optional feature bit that signals that the receiver
+	// of a payment supports accepts spontaneous payments, i.e.
+	// sender-generated preimages according to BOLT XX.
+	AMPOptional FeatureBit = 31
+
 	// maxAllowedSize is a maximum allowed size of feature vector.
 	//
 	// NOTE: Within the protocol, the maximum allowed message size is 65535
@@ -172,6 +182,8 @@ var Features = map[FeatureBit]string{
 	AnchorsZeroFeeHtlcTxOptional:  "anchors-zero-fee-htlc-tx",
 	WumboChannelsRequired:         "wumbo-channels",
 	WumboChannelsOptional:         "wumbo-channels",
+	AMPRequired:                   "amp",
+	AMPOptional:                   "amp",
 }
 
 // RawFeatureVector represents a set of feature bits as defined in BOLT-09.  A