highperfocused/lnd
1
0
Fork 0
mirror of https://github.com/lightningnetwork/lnd.git synced 2025-09-26 19:47:07 +02:00
Code Issues Packages Projects Releases Wiki Activity

multi: explicitly signal final hop in pack hop payload

Browse Source 
Previously, we'd use the value of nextChanID to infer whether a payload
was for the final hop in a route. This commit updates our packing logic
to explicitly signal to account for blinded routes, which allow zero
value nextChanID in intermediate hops. This is a preparatory commit
that allows us to more thoroughly validate payloads.
This commit is contained in:
Carla Kirk-Cohen
2023-11-01 10:46:48 -04:00
parent b5afd905d1
commit 585f28c5f5
3 changed files with 20 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
routing/route/route.go
View File

@@ -172,11 +172,15 @@ func (h *Hop) Copy() *Hop {
// PackHopPayload writes to the passed io.Writer, the series of byes that can
// be placed directly into the per-hop payload (EOB) for this hop. This will
// include the required routing fields, as well as serializing any of the
// passed optional TLVRecords. nextChanID is the unique channel ID that
// references the _outgoing_ channel ID that follows this hop. This field
// follows the same semantics as the NextAddress field in the onion: it should
// be set to zero to indicate the terminal hop.
func (h *Hop) PackHopPayload(w io.Writer, nextChanID uint64) error {
// passed optional TLVRecords. nextChanID is the unique channel ID that
// references the _outgoing_ channel ID that follows this hop. The lastHop bool
// is used to signal whether this hop is the final hop in a route. Previously,
// a zero nextChanID would be used for this purpose, but with the addition of
// blinded routes which allow zero nextChanID values for intermediate hops we
// add an explicit signal.
func (h *Hop) PackHopPayload(w io.Writer, nextChanID uint64,
finalHop bool) error {
// If this is a legacy payload, then we'll exit here as this method
// shouldn't be called.
if h.LegacyPayload == true {
@@ -218,7 +222,7 @@ func (h *Hop) PackHopPayload(w io.Writer, nextChanID uint64) error {
// attach it to the final hop. Otherwise the route was constructed
// incorrectly.
if h.MPP != nil {
if nextChanID == 0 {
if finalHop {
records = append(records, h.MPP.Record())
} else {
return ErrIntermediateMPPHop
@@ -559,7 +563,8 @@ func (r *Route) ToSphinxPath() (*sphinx.PaymentPath, error) {
// If we aren't on the last hop, then we set the "next address"
// field to be the channel that directly follows it.
if i != len(r.Hops)-1 {
finalHop := i == len(r.Hops)-1
if !finalHop {
nextHop = r.Hops[i+1].ChannelID
}
@@ -591,7 +596,7 @@ func (r *Route) ToSphinxPath() (*sphinx.PaymentPath, error) {
// channel should be forwarded to so we can construct a
// valid payload.
var b bytes.Buffer
err := hop.PackHopPayload(&b, nextHop)
err := hop.PackHopPayload(&b, nextHop, finalHop)
if err != nil {
return nil, err
}