routerrpc: connect UnmarshallRoute to existing config fields

lnrpc/routerrpc/router_backend.go

@@ -6,7 +6,6 @@ import (
 	"fmt"
 
 	"github.com/btcsuite/btcutil"
-	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/routing"
@@ -27,6 +26,11 @@ type RouterBackend struct {
 	// capacity of a channel to populate in responses.
 	FetchChannelCapacity func(chanID uint64) (btcutil.Amount, error)
 
+	// FetchChannelEndpoints returns the pubkeys of both endpoints of the
+	// given channel id.
+	FetchChannelEndpoints func(chanID uint64) (route.Vertex,
+		route.Vertex, error)
+
 	// FindRoutes is a closure that abstracts away how we locate/query for
 	// routes.
 	FindRoute func(source, target route.Vertex,
@@ -224,22 +228,21 @@ func (r *RouterBackend) MarshallRoute(route *route.Route) *lnrpc.Route {
 // not known. This function will query the channel graph with channel id to
 // retrieve both endpoints and determine the hop pubkey using the previous hop
 // pubkey. If the channel is unknown, an error is returned.
-func UnmarshallHopByChannelLookup(graph *channeldb.ChannelGraph, hop *lnrpc.Hop,
+func (r *RouterBackend) UnmarshallHopByChannelLookup(hop *lnrpc.Hop,
 	prevPubKeyBytes [33]byte) (*route.Hop, error) {
 
 	// Discard edge policies, because they may be nil.
-	edgeInfo, _, _, err := graph.FetchChannelEdgesByID(hop.ChanId)
+	node1, node2, err := r.FetchChannelEndpoints(hop.ChanId)
 	if err != nil {
-		return nil, fmt.Errorf("unable to fetch channel edges by "+
-			"channel ID %d: %v", hop.ChanId, err)
+		return nil, err
 	}
 
 	var pubKeyBytes [33]byte
 	switch {
-	case prevPubKeyBytes == edgeInfo.NodeKey1Bytes:
-		pubKeyBytes = edgeInfo.NodeKey2Bytes
-	case prevPubKeyBytes == edgeInfo.NodeKey2Bytes:
-		pubKeyBytes = edgeInfo.NodeKey1Bytes
+	case prevPubKeyBytes == node1:
+		pubKeyBytes = node2
+	case prevPubKeyBytes == node2:
+		pubKeyBytes = node1
 	default:
 		return nil, fmt.Errorf("channel edge does not match expected node")
 	}
@@ -248,7 +251,7 @@ func UnmarshallHopByChannelLookup(graph *channeldb.ChannelGraph, hop *lnrpc.Hop,
 		OutgoingTimeLock: hop.Expiry,
 		AmtToForward:     lnwire.MilliSatoshi(hop.AmtToForwardMsat),
 		PubKeyBytes:      pubKeyBytes,
-		ChannelID:        edgeInfo.ChannelID,
+		ChannelID:        hop.ChanId,
 	}, nil
 }
 
@@ -274,14 +277,14 @@ func UnmarshallKnownPubkeyHop(hop *lnrpc.Hop) (*route.Hop, error) {
 
 // UnmarshallHop unmarshalls an rpc hop that may or may not contain a node
 // pubkey.
-func UnmarshallHop(graph *channeldb.ChannelGraph, hop *lnrpc.Hop,
+func (r *RouterBackend) UnmarshallHop(hop *lnrpc.Hop,
 	prevNodePubKey [33]byte) (*route.Hop, error) {
 
 	if hop.PubKey == "" {
 		// If no pub key is given of the hop, the local channel
 		// graph needs to be queried to complete the information
 		// necessary for routing.
-		return UnmarshallHopByChannelLookup(graph, hop, prevNodePubKey)
+		return r.UnmarshallHopByChannelLookup(hop, prevNodePubKey)
 	}
 
 	return UnmarshallKnownPubkeyHop(hop)
@@ -289,21 +292,14 @@ func UnmarshallHop(graph *channeldb.ChannelGraph, hop *lnrpc.Hop,
 
 // UnmarshallRoute unmarshalls an rpc route. For hops that don't specify a
 // pubkey, the channel graph is queried.
-func UnmarshallRoute(rpcroute *lnrpc.Route,
-	graph *channeldb.ChannelGraph) (*route.Route, error) {
+func (r *RouterBackend) UnmarshallRoute(rpcroute *lnrpc.Route) (
+	*route.Route, error) {
 
-	sourceNode, err := graph.SourceNode()
-	if err != nil {
-		return nil, fmt.Errorf("unable to fetch source node from graph "+
-			"while unmarshaling route. %v", err)
-	}
-
-	prevNodePubKey := sourceNode.PubKeyBytes
+	prevNodePubKey := r.SelfNode
 
 	hops := make([]*route.Hop, len(rpcroute.Hops))
 	for i, hop := range rpcroute.Hops {
-		routeHop, err := UnmarshallHop(graph,
-			hop, prevNodePubKey)
+		routeHop, err := r.UnmarshallHop(hop, prevNodePubKey)
 		if err != nil {
 			return nil, err
 		}
@@ -316,7 +312,7 @@ func UnmarshallRoute(rpcroute *lnrpc.Route,
 	route, err := route.NewRouteFromHops(
 		lnwire.MilliSatoshi(rpcroute.TotalAmtMsat),
 		rpcroute.TotalTimeLock,
-		sourceNode.PubKeyBytes,
+		r.SelfNode,
 		hops,
 	)
 	if err != nil {

rpcserver.go

@@ -462,6 +462,21 @@ func newRPCServer(s *server, macService *macaroons.Service,
 			}
 			return info.Capacity, nil
 		},
+		FetchChannelEndpoints: func(chanID uint64) (route.Vertex,
+			route.Vertex, error) {
+
+			info, _, _, err := graph.FetchChannelEdgesByID(
+				chanID,
+			)
+			if err != nil {
+				return route.Vertex{}, route.Vertex{},
+					fmt.Errorf("unable to fetch channel "+
+						"edges by channel ID %d: %v",
+						chanID, err)
+			}
+
+			return info.NodeKey1Bytes, info.NodeKey2Bytes, nil
+		},
 		FindRoute: s.chanRouter.FindRoute,
 	}
 
@@ -2837,9 +2852,7 @@ func (r *rpcServer) SendToRoute(stream lnrpc.Lightning_SendToRouteServer) error
 				return nil, err
 			}
 
-			graph := r.server.chanDB.ChannelGraph()
-
-			return unmarshallSendToRouteRequest(req, graph)
+			return r.unmarshallSendToRouteRequest(req)
 		},
 		send: func(r *lnrpc.SendResponse) error {
 			// Calling stream.Send concurrently is not safe.
@@ -2851,14 +2864,14 @@ func (r *rpcServer) SendToRoute(stream lnrpc.Lightning_SendToRouteServer) error
 }
 
 // unmarshallSendToRouteRequest unmarshalls an rpc sendtoroute request
-func unmarshallSendToRouteRequest(req *lnrpc.SendToRouteRequest,
-	graph *channeldb.ChannelGraph) (*rpcPaymentRequest, error) {
+func (r *rpcServer) unmarshallSendToRouteRequest(
+	req *lnrpc.SendToRouteRequest) (*rpcPaymentRequest, error) {
 
 	if req.Route == nil {
 		return nil, fmt.Errorf("unable to send, no route provided")
 	}
 
-	route, err := routerrpc.UnmarshallRoute(req.Route, graph)
+	route, err := r.routerBackend.UnmarshallRoute(req.Route)
 	if err != nil {
 		return nil, err
 	}
@@ -3308,9 +3321,7 @@ func (r *rpcServer) SendToRouteSync(ctx context.Context,
 		return nil, fmt.Errorf("unable to send, no routes provided")
 	}
 
-	graph := r.server.chanDB.ChannelGraph()
-
-	paymentRequest, err := unmarshallSendToRouteRequest(req, graph)
+	paymentRequest, err := r.unmarshallSendToRouteRequest(req)
 	if err != nil {
 		return nil, err
 	}