routing+routerrpc: add multiple outgoing channel restriction

rpcserver.go

@@ -3687,18 +3687,18 @@ func (r *rpcServer) unmarshallSendToRouteRequest(
 // hints), or we'll get a fully populated route from the user that we'll pass
 // directly to the channel router for dispatching.
 type rpcPaymentIntent struct {
-	msat              lnwire.MilliSatoshi
-	feeLimit          lnwire.MilliSatoshi
-	cltvLimit         uint32
-	dest              route.Vertex
-	rHash             [32]byte
-	cltvDelta         uint16
-	routeHints        [][]zpay32.HopHint
-	outgoingChannelID *uint64
-	lastHop           *route.Vertex
-	destFeatures      *lnwire.FeatureVector
-	paymentAddr       *[32]byte
-	payReq            []byte
+	msat               lnwire.MilliSatoshi
+	feeLimit           lnwire.MilliSatoshi
+	cltvLimit          uint32
+	dest               route.Vertex
+	rHash              [32]byte
+	cltvDelta          uint16
+	routeHints         [][]zpay32.HopHint
+	outgoingChannelIDs []uint64
+	lastHop            *route.Vertex
+	destFeatures       *lnwire.FeatureVector
+	paymentAddr        *[32]byte
+	payReq             []byte
 
 	destCustomRecords record.CustomSet
 
@@ -3734,9 +3734,12 @@ func (r *rpcServer) extractPaymentIntent(rpcPayReq *rpcPaymentRequest) (rpcPayme
 	}
 
 	// If there are no routes specified, pass along a outgoing channel
-	// restriction if specified.
+	// restriction if specified. The main server rpc does not support
+	// multiple channel restrictions.
 	if rpcPayReq.OutgoingChanId != 0 {
-		payIntent.outgoingChannelID = &rpcPayReq.OutgoingChanId
+		payIntent.outgoingChannelIDs = []uint64{
+			rpcPayReq.OutgoingChanId,
+		}
 	}
 
 	// Pass along a last hop restriction if specified.
@@ -3951,20 +3954,20 @@ func (r *rpcServer) dispatchPaymentIntent(
 	// router, otherwise we'll create a payment session to execute it.
 	if payIntent.route == nil {
 		payment := &routing.LightningPayment{
-			Target:            payIntent.dest,
-			Amount:            payIntent.msat,
-			FinalCLTVDelta:    payIntent.cltvDelta,
-			FeeLimit:          payIntent.feeLimit,
-			CltvLimit:         payIntent.cltvLimit,
-			PaymentHash:       payIntent.rHash,
-			RouteHints:        payIntent.routeHints,
-			OutgoingChannelID: payIntent.outgoingChannelID,
-			LastHop:           payIntent.lastHop,
-			PaymentRequest:    payIntent.payReq,
-			PayAttemptTimeout: routing.DefaultPayAttemptTimeout,
-			DestCustomRecords: payIntent.destCustomRecords,
-			DestFeatures:      payIntent.destFeatures,
-			PaymentAddr:       payIntent.paymentAddr,
+			Target:             payIntent.dest,
+			Amount:             payIntent.msat,
+			FinalCLTVDelta:     payIntent.cltvDelta,
+			FeeLimit:           payIntent.feeLimit,
+			CltvLimit:          payIntent.cltvLimit,
+			PaymentHash:        payIntent.rHash,
+			RouteHints:         payIntent.routeHints,
+			OutgoingChannelIDs: payIntent.outgoingChannelIDs,
+			LastHop:            payIntent.lastHop,
+			PaymentRequest:     payIntent.payReq,
+			PayAttemptTimeout:  routing.DefaultPayAttemptTimeout,
+			DestCustomRecords:  payIntent.destCustomRecords,
+			DestFeatures:       payIntent.destFeatures,
+			PaymentAddr:        payIntent.paymentAddr,
 
 			// Don't enable multi-part payments on the main rpc.
 			// Users need to use routerrpc for that.