highperfocused/lnd
1
0
Fork 0
mirror of https://github.com/lightningnetwork/lnd.git synced 2025-08-30 07:35:07 +02:00
Code Issues Packages Projects Releases Wiki Activity

discovery: prevent rebroadcast of premature channel updates

Browse Source 
As similarly done with premature channel announcements, we'll no longer
allow premature channel updates to be rebroadcast once mature. This is
no longer necessary as channel announcements that we're not aware of are
usually broadcast to us with their accompanying channel updates.
This commit is contained in:
Wilmer Paulino
2021-01-04 17:58:45 -08:00
parent faa399f942
commit 00d4e92362
2 changed files with 28 additions and 328 deletions
Download Patch File Download Diff File Expand all files Collapse all files

101
discovery/gossiper.go
View File

@@ -265,13 +265,6 @@ type AuthenticatedGossiper struct {
// every new block height.
blockEpochs *chainntnfs.BlockEpochEvent
// prematureChannelUpdates is a map of ChannelUpdates we have received
// that wasn't associated with any channel we know about. We store
// them temporarily, such that we can reprocess them when a
// ChannelAnnouncement for the channel is received.
prematureChannelUpdates map[uint64][]*networkMsg
pChanUpdMtx sync.Mutex
// networkMsgs is a channel that carries new network broadcasted
// message from outside the gossiper service to be processed by the
// networkHandler.
@@ -328,7 +321,6 @@ func New(cfg Config, selfKey *btcec.PublicKey) *AuthenticatedGossiper {
networkMsgs: make(chan *networkMsg),
quit: make(chan struct{}),
chanPolicyUpdates: make(chan *chanPolicyUpdateRequest),
prematureChannelUpdates: make(map[uint64][]*networkMsg),
channelMtx: multimutex.NewMutex(),
recentRejects: make(map[uint64]struct{}),
heightForLastChanUpdate: make(map[uint64][2]uint32),
@@ -1022,8 +1014,7 @@ func (d *AuthenticatedGossiper) networkHandler() {
}()
// A new block has arrived, so we can re-process the previously
// premature announcements.
// A new block has arrived, update our best height.
case newBlock, ok := <-d.blockEpochs.Epochs:
// If the channel has been closed, then this indicates
// the daemon is shutting down, so we exit ourselves.
@@ -1690,55 +1681,6 @@ func (d *AuthenticatedGossiper) processNetworkAnnouncement(
return nil
}
// If we earlier received any ChannelUpdates for this channel,
// we can now process them, as the channel is added to the
// graph.
shortChanID := msg.ShortChannelID.ToUint64()
var channelUpdates []*networkMsg
d.pChanUpdMtx.Lock()
channelUpdates = append(channelUpdates, d.prematureChannelUpdates[shortChanID]...)
// Now delete the premature ChannelUpdates, since we added them
// all to the queue of network messages.
delete(d.prematureChannelUpdates, shortChanID)
d.pChanUpdMtx.Unlock()
// Launch a new goroutine to handle each ChannelUpdate, this to
// ensure we don't block here, as we can handle only one
// announcement at a time.
for _, cu := range channelUpdates {
d.wg.Add(1)
go func(nMsg *networkMsg) {
defer d.wg.Done()
switch msg := nMsg.msg.(type) {
// Reprocess the message, making sure we return
// an error to the original caller in case the
// gossiper shuts down.
case *lnwire.ChannelUpdate:
log.Debugf("Reprocessing"+
" ChannelUpdate for "+
"shortChanID=%v",
msg.ShortChannelID.ToUint64())
select {
case d.networkMsgs <- nMsg:
case <-d.quit:
nMsg.err <- ErrGossiperShuttingDown
}
// We don't expect any other message type than
// ChannelUpdate to be in this map.
default:
log.Errorf("Unsupported message type "+
"found among ChannelUpdates: "+
"%T", msg)
}
}(cu)
}
// Channel announcement was successfully proceeded and know it
// might be broadcast to other connected nodes if it was
// announcement with proof (remote).
@@ -1777,8 +1719,7 @@ func (d *AuthenticatedGossiper) processNetworkAnnouncement(
shortChanID := msg.ShortChannelID.ToUint64()
// If the advertised inclusionary block is beyond our knowledge
// of the chain tip, then we'll put the announcement in limbo
// to be fully verified once we advance forward in the chain.
// of the chain tip, then we'll ignore it.
d.Lock()
if nMsg.isRemote && isPremature(msg.ShortChannelID, 0) {
log.Infof("Update announcement for "+
@@ -1787,6 +1728,8 @@ func (d *AuthenticatedGossiper) processNetworkAnnouncement(
shortChanID, blockHeight,
d.bestHeight)
d.Unlock()
nMsg.err <- nil
return nil
}
d.Unlock()
@@ -1857,43 +1800,19 @@ func (d *AuthenticatedGossiper) processNetworkAnnouncement(
log.Debugf("Removed edge with chan_id=%v from zombie "+
"index", msg.ShortChannelID)
// We'll fallthrough to ensure we stash the update until
// we receive its corresponding ChannelAnnouncement.
// This is needed to ensure the edge exists in the graph
// before applying the update.
fallthrough
nMsg.err <- nil
return nil
case channeldb.ErrGraphNotFound:
fallthrough
case channeldb.ErrGraphNoEdgesFound:
fallthrough
case channeldb.ErrEdgeNotFound:
// If the edge corresponding to this ChannelUpdate was
// not found in the graph, this might be a channel in
// the process of being opened, and we haven't processed
// our own ChannelAnnouncement yet, hence it is not
// found in the graph. This usually gets resolved after
// the channel proofs are exchanged and the channel is
// broadcasted to the rest of the network, but in case
// this is a private channel this won't ever happen.
// This can also happen in the case of a zombie channel
// with a fresh update for which we don't have a
// ChannelAnnouncement for since we reject them. Because
// of this, we temporarily add it to a map, and
// reprocess it after our own ChannelAnnouncement has
// been processed.
d.pChanUpdMtx.Lock()
d.prematureChannelUpdates[shortChanID] = append(
d.prematureChannelUpdates[shortChanID], nMsg,
)
d.pChanUpdMtx.Unlock()
log.Debugf("Got ChannelUpdate for edge not found in "+
"graph(shortChanID=%v), saving for "+
"reprocessing later", shortChanID)
"graph(shortChanID=%v)", shortChanID)
// NOTE: We don't return anything on the error channel
// for this message, as we expect that will be done when
// this ChannelUpdate is later reprocessed.
// TODO: Add to recentRejects like below? Return error?
nMsg.err <- nil
return nil
default: