From a6c814010cd7495e6c41674b5ac692c6ccd2ac45 Mon Sep 17 00:00:00 2001 From: Olaoluwa Osuntokun Date: Mon, 30 Jul 2018 13:40:56 -0700 Subject: [PATCH] routing: exit gracefully if generateSphinxPacket is passed a nil set of hops --- routing/router.go | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/routing/router.go b/routing/router.go index d32305f4c..dcef3a283 100644 --- a/routing/router.go +++ b/routing/router.go @@ -38,6 +38,13 @@ const ( defaultPayAttemptTimeout = time.Duration(time.Second * 60) ) +var ( + // ErrNoRouteHopsProvided is returned when a caller attempts to + // construct a new sphinx packet, but provides an empty set of hops for + // each route. + ErrNoRouteHopsProvided = fmt.Errorf("empty route hops provided") +) + // ChannelGraphSource represents the source of information about the topology // of the lightning network. It's responsible for the addition of nodes, edges, // applying edge updates, and returning the current block height with which the @@ -1412,6 +1419,14 @@ func (r *ChannelRouter) FindRoutes(target *btcec.PublicKey, // be sent to the first hop within the route. func generateSphinxPacket(route *Route, paymentHash []byte) ([]byte, *sphinx.Circuit, error) { + + // As a sanity check, we'll ensure that the set of hops has been + // properly filled in, otherwise, we won't actually be able to + // construct a route. + if len(route.Hops) == 0 { + return nil, nil, ErrNoRouteHopsProvided + } + // First obtain all the public keys along the route which are contained // in each hop. nodes := make([]*btcec.PublicKey, len(route.Hops))