peer+server: make fetchLastChanUpdate _always_ fetch our own update

This commit fixes a bug that would cause us to fetch our peer's
ChannelUpdate in some cases, where we really wanted to fetch our own.

The reason this happened was that we passed the peer's pubkey to
fetchLastChanUpdate, making us match on their policy. This would lead to
ChannelUpdates being sent during routing which would have no effect on
the attempted path.

We fix this by always use our own pubkey in fetchLastChanUpdate, and
also uses the common methods within the server to be able to extract the
update even when only one policy is known.
This commit is contained in:
Johan T. Halseth 2018-08-22 09:32:44 +02:00
parent de5e9e139c
commit 19e3a194fa
No known key found for this signature in database
GPG Key ID: 15BAADA29DA20D26
2 changed files with 30 additions and 47 deletions

60
peer.go
View File

@ -539,22 +539,20 @@ func (p *peer) addLink(chanPoint *wire.OutPoint,
}
linkCfg := htlcswitch.ChannelLinkConfig{
Peer: p,
DecodeHopIterators: p.server.sphinx.DecodeHopIterators,
ExtractErrorEncrypter: p.server.sphinx.ExtractErrorEncrypter,
FetchLastChannelUpdate: fetchLastChanUpdate(
p.server, p.PubKey(),
),
DebugHTLC: cfg.DebugHTLC,
HodlMask: cfg.Hodl.Mask(),
Registry: p.server.invoices,
Switch: p.server.htlcSwitch,
Circuits: p.server.htlcSwitch.CircuitModifier(),
ForwardPackets: p.server.htlcSwitch.ForwardPackets,
FwrdingPolicy: *forwardingPolicy,
FeeEstimator: p.server.cc.feeEstimator,
PreimageCache: p.server.witnessBeacon,
ChainEvents: chainEvents,
Peer: p,
DecodeHopIterators: p.server.sphinx.DecodeHopIterators,
ExtractErrorEncrypter: p.server.sphinx.ExtractErrorEncrypter,
FetchLastChannelUpdate: p.server.fetchLastChanUpdate(),
DebugHTLC: cfg.DebugHTLC,
HodlMask: cfg.Hodl.Mask(),
Registry: p.server.invoices,
Switch: p.server.htlcSwitch,
Circuits: p.server.htlcSwitch.CircuitModifier(),
ForwardPackets: p.server.htlcSwitch.ForwardPackets,
FwrdingPolicy: *forwardingPolicy,
FeeEstimator: p.server.cc.feeEstimator,
PreimageCache: p.server.witnessBeacon,
ChainEvents: chainEvents,
UpdateContractSignals: func(signals *contractcourt.ContractSignals) error {
return p.server.chainArb.UpdateContractSignals(
*chanPoint, signals,
@ -2112,33 +2110,3 @@ func (p *peer) StartTime() time.Time {
}
// TODO(roasbeef): make all start/stop mutexes a CAS
// fetchLastChanUpdate returns a function which is able to retrieve the last
// channel update for a target channel.
func fetchLastChanUpdate(s *server,
pubKey [33]byte) func(lnwire.ShortChannelID) (*lnwire.ChannelUpdate, error) {
return func(cid lnwire.ShortChannelID) (*lnwire.ChannelUpdate, error) {
info, edge1, edge2, err := s.chanRouter.GetChannelByID(cid)
if err != nil {
return nil, err
}
if edge1 == nil || edge2 == nil {
return nil, fmt.Errorf("unable to find channel by "+
"ShortChannelID(%v)", cid)
}
// If we're the outgoing node on the first edge, then that
// means the second edge is our policy. Otherwise, the first
// edge is our policy.
var local *channeldb.ChannelEdgePolicy
if bytes.Equal(edge1.Node.PubKeyBytes[:], pubKey[:]) {
local = edge2
} else {
local = edge1
}
return extractChannelUpdate(pubKey[:], info, local)
}
}

View File

@ -336,7 +336,7 @@ func newServer(listenAddrs []net.Addr, chanDB *channeldb.DB, cc *chainControl,
FwdingLog: chanDB.ForwardingLog(),
SwitchPackager: channeldb.NewSwitchPackager(),
ExtractErrorEncrypter: s.sphinx.ExtractErrorEncrypter,
FetchLastChannelUpdate: fetchLastChanUpdate(s, serializedPubKey),
FetchLastChannelUpdate: s.fetchLastChanUpdate(),
Notifier: s.cc.chainNotifier,
FwdEventTicker: ticker.New(
htlcswitch.DefaultFwdEventInterval),
@ -2957,6 +2957,21 @@ func (s *server) fetchLastChanUpdateByOutPoint(op wire.OutPoint) (
return extractChannelUpdate(pubKey, info, edge1, edge2)
}
// fetchLastChanUpdate returns a function which is able to retrieve our latest
// channel update for a target channel.
func (s *server) fetchLastChanUpdate() func(lnwire.ShortChannelID) (
*lnwire.ChannelUpdate, error) {
ourPubKey := s.identityPriv.PubKey().SerializeCompressed()
return func(cid lnwire.ShortChannelID) (*lnwire.ChannelUpdate, error) {
info, edge1, edge2, err := s.chanRouter.GetChannelByID(cid)
if err != nil {
return nil, err
}
return extractChannelUpdate(ourPubKey[:], info, edge1, edge2)
}
}
// extractChannelUpdate attempts to retrieve a lnwire.ChannelUpdate message
// from an edge's info and a set of routing policies.
// NOTE: the passed policies can be nil.