From 35dd5f354d44691991a9bc6a694947e710377e02 Mon Sep 17 00:00:00 2001
From: Conner Fromknecht <conner@lightning.engineering>
Date: Wed, 18 Dec 2019 23:57:38 -0800
Subject: [PATCH] routerrpc: parse dest_features bits for manual SendPayment

---
 lnrpc/routerrpc/router_backend.go | 23 +++++++++++++++++++++++
 rpcserver.go                      |  8 ++++++++
 2 files changed, 31 insertions(+)

diff --git a/lnrpc/routerrpc/router_backend.go b/lnrpc/routerrpc/router_backend.go
index 383180a3..acd3125a 100644
--- a/lnrpc/routerrpc/router_backend.go
+++ b/lnrpc/routerrpc/router_backend.go
@@ -633,6 +633,14 @@ func (r *RouterBackend) extractIntentFromSendRequest(
 
 		// Payment hash.
 		copy(payIntent.PaymentHash[:], rpcPayReq.PaymentHash)
+
+		// Parse destination feature bits.
+		features, err := UnmarshalFeatures(rpcPayReq.DestFeatures)
+		if err != nil {
+			return nil, err
+		}
+
+		payIntent.DestFeatures = features
 	}
 
 	// Currently, within the bootstrap phase of the network, we limit the
@@ -699,6 +707,21 @@ func unmarshallHopHint(rpcHint *lnrpc.HopHint) (zpay32.HopHint, error) {
 	}, nil
 }
 
+// UnmarshalFeatures converts a list of uint32's into a valid feature vector.
+// This method checks that feature bit pairs aren't assigned toegether, and
+// validates transitive depdencies.
+func UnmarshalFeatures(rpcFeatures []lnrpc.FeatureBit) (*lnwire.FeatureVector, error) {
+	raw := lnwire.NewRawFeatureVector()
+	for _, bit := range rpcFeatures {
+		err := raw.SafeSet(lnwire.FeatureBit(bit))
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return lnwire.NewFeatureVector(raw, lnwire.Features), nil
+}
+
 // ValidatePayReqExpiry checks if the passed payment request has expired. In
 // the case it has expired, an error will be returned.
 func ValidatePayReqExpiry(payReq *zpay32.Invoice) error {
diff --git a/rpcserver.go b/rpcserver.go
index 1e5e71b1..239df76d 100644
--- a/rpcserver.go
+++ b/rpcserver.go
@@ -3442,6 +3442,14 @@ func (r *rpcServer) extractPaymentIntent(rpcPayReq *rpcPaymentRequest) (rpcPayme
 		copy(payIntent.rHash[:], rpcPayReq.PaymentHash)
 	}
 
+	// Unmarshal any custom destination features.
+	payIntent.destFeatures, err = routerrpc.UnmarshalFeatures(
+		rpcPayReq.DestFeatures,
+	)
+	if err != nil {
+		return payIntent, err
+	}
+
 	// Currently, within the bootstrap phase of the network, we limit the
 	// largest payment size allotted to (2^32) - 1 mSAT or 4.29 million
 	// satoshis.