lnrpc+rpcserver: populate experimental MPP fields in ListPayment rpc

lnrpc/routerrpc/router_backend.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/btcsuite/btcd/chaincfg"
 	"github.com/btcsuite/btcutil"
+	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lntypes"
 	"github.com/lightningnetwork/lnd/lnwire"
@@ -779,3 +780,48 @@ func UnmarshalMPP(reqMPP *lnrpc.MPPRecord) (*record.MPP, error) {
 
 	return record.NewMPP(total, addr), nil
 }
+
+// MarshalHTLCAttempt constructs an RPC HTLCAttempt from the db representation.
+func (r *RouterBackend) MarshalHTLCAttempt(
+	htlc channeldb.HTLCAttempt) (*lnrpc.HTLCAttempt, error) {
+
+	var (
+		status      lnrpc.HTLCAttempt_HTLCStatus
+		resolveTime int64
+	)
+
+	switch {
+	case htlc.Settle != nil:
+		status = lnrpc.HTLCAttempt_SUCCEEDED
+		resolveTime = MarshalTimeNano(htlc.Settle.SettleTime)
+
+	case htlc.Failure != nil:
+		status = lnrpc.HTLCAttempt_FAILED
+		resolveTime = MarshalTimeNano(htlc.Failure.FailTime)
+
+	default:
+		status = lnrpc.HTLCAttempt_IN_FLIGHT
+	}
+
+	route, err := r.MarshallRoute(&htlc.Route)
+	if err != nil {
+		return nil, err
+	}
+
+	return &lnrpc.HTLCAttempt{
+		Status:        status,
+		Route:         route,
+		AttemptTimeNs: MarshalTimeNano(htlc.AttemptTime),
+		ResolveTimeNs: resolveTime,
+	}, nil
+}
+
+// MarshalTimeNano converts a time.Time into its nanosecond representation. If
+// the time is zero, this method simply returns 0, since calling UnixNano() on a
+// zero-valued time is undefined.
+func MarshalTimeNano(t time.Time) int64 {
+	if t.IsZero() {
+		return 0
+	}
+	return t.UnixNano()
+}

rpcserver.go

@@ -4379,13 +4379,25 @@ func (r *rpcServer) ListPayments(ctx context.Context,
 			return nil, err
 		}
 
+		htlcs := make([]*lnrpc.HTLCAttempt, 0, len(payment.HTLCs))
+		for _, dbHTLC := range payment.HTLCs {
+			htlc, err := r.routerBackend.MarshalHTLCAttempt(dbHTLC)
+			if err != nil {
+				return nil, err
+			}
+
+			htlcs = append(htlcs, htlc)
+		}
+
 		paymentHash := payment.Info.PaymentHash
+		creationTimeNS := routerrpc.MarshalTimeNano(payment.Info.CreationTime)
 		paymentsResp.Payments = append(paymentsResp.Payments, &lnrpc.Payment{
 			PaymentHash:     hex.EncodeToString(paymentHash[:]),
 			Value:           satValue,
 			ValueMsat:       msatValue,
 			ValueSat:        satValue,
 			CreationDate:    payment.Info.CreationTime.Unix(),
+			CreationTimeNs:  creationTimeNS,
 			Path:            path,
 			Fee:             int64(route.TotalFees().ToSatoshis()),
 			FeeSat:          int64(route.TotalFees().ToSatoshis()),
@@ -4393,6 +4405,7 @@ func (r *rpcServer) ListPayments(ctx context.Context,
 			PaymentPreimage: hex.EncodeToString(preimage[:]),
 			PaymentRequest:  string(payment.Info.PaymentRequest),
 			Status:          status,
+			Htlcs:           htlcs,
 		})
 	}