This commit passes the peer's quit signal to the
gossipSyncer when attempt to hand off gossip query
messages. This allows a rate-limited peer's read
handler to break out immediately, which would
otherwise remain stuck until the rate-limited
gossip syncer pulled the message.
This commit restructures the delivery of gossip
query related messages, such that they are delivered
directly to the gossip syncers. Gossip query rate
limiting was introduced in #1824 on a per-peer basis.
However, since all gossip query messages were being
delivered in the main event loop, the end result is
that one rate-limited peer could stall all other
peers.
In addition, since no other peers would be able to
submit gossip-related messages through the blocked
event loop, the back pressure would eventually rate
limit the read handlers of all peers as well.
The end result would be lengthy delays in reading
messages related to htlc forwarding.
The fix is to lift the delivery of gossip query
messages outside of the main event loop. With
this change, the rate limiting backpressure is
delivered only to the intended peer.
To mimic the current behaviour of the router's IsStaleNode, we make the
mockGraphSource consider a unknown node with no channels in the graph as
stale.
ann last
In this commit, we modify TestProcessAnnouncement to process the node
announcement last. We do this due to the recent change in the gossiper
where we'll only forward node announcements of nodes who intend to
advertised themselves within the network.
This change was needed in order to allow the node announcement to be
broadcast to the greater network, as otherwise the gossiper would assume
the node intends to stay private due to not having any advertised edges.
In this commit, we modify the gossiper to no longer broadcast
NodeAnnouncements of nodes who intend to remain private. We do this to
prevent leaking their information to the greater network.
Previously, gossiper was the only object that validated channel
updates. Because updates can also be received as part of a
failed payment session in the routing package, validation logic
needs to be available there too. Gossiper already depends on
routing and having routing call the validation logic inside
gossiper would be a circular dependency. Therefore the validation
was moved to routing.
This commit replaces the simplistic rate limiting
technique added in 557cb6e2, to use the
golang.org/x/time's rate limiter. This has the
benefit of performing traffic shaping to meet a
target maximum rate, and yet tolerate bursts. Bursts
are expected during initial sync, though should become
more rare afterwards. Performing traffic shaping with
this mechanism should improve the ability of the gossip
syncer to detect sustained bursts from the remote peer,
and penalize them appropriately.
This commit also modifies the default parameters to
accept bursts of 10 queries, with a target rate of 1
reply every 5 seconds.
This commit removes the fallback in fetchGossipSyncer
that creates a gossip syncer if one is not registered
w/in the gossiper. Now that we register gossip syncers
explicitly before reading any gossip query messages,
this should not longer be required. The fallback also
did not honor the cfg.NoChanUpdates flag, which may
have led to inconsistencies between configuration and
actual behavior.
restransmitStaleChannels
In this commit, we add an additional error check for
ErrNoGraphEdgesFound when restransmitting stale channels during the
gossiper's startup. We do this to prevent benign log messages as we'll
log that we were unable to retransmit stale channels when we didn't have
any channels in our graph to begin with.
In this commit, we aim to resolve an issue with nodes requesting for
channel announcements when receiving a channel update for a channel
they're not aware of. This can happen if a node is not caught up with
the chain or if they receive updates for zombie channels. This would
lead to a spam issue, as if a node is not caught up with the chain,
every new update they receive is premature, causing them to manually
request the backing channel announcement. Ideally, we should be able to
detect this as a potential DoS vector and ban the node responsible, but
for now we'll simply remove this functionality.
In this commit, we select on the peer's QuitSignal to allow the caller
to unblock if the peer itself is disconnecting. With this change, we now
ensure that it isn't possible for a peer to block on this method and
prevent a graceful exit.
Previosuly we would immediately return nil on the error channel for
premature ChannelUpdates, which would break the expection that a a
returned non-error meant the update was successfully added to the
database. This meant that the caller would believe the update was added
to the database, while it is actually still in volatile memory and can
be lost during restarts.
This change makes us handle premature ChannelUpdates as we handle other
premature announcements within the gossiper, by deferring sending on the
error channel until we have reprocessed the update.
Previously we wouldn't return anything in the case where the
announcement were meant for a chain we didn't recognize. After this
change we should return an error on the error channel in all flows
within the gossiper.
Corrects an instance that holds a reference to a boltdb
byte slice after returning from the transaction. This
can cause panics under certain conditions, which is
avoided by creating a copy of the key.
In this commit, we allow the gossiper syncer to store the chunk size for
its respective encoding type. We do this to prevent a race condition
that would arise within the unit tests by modifying the values of the
encodingTypeToChunkSize map to allow for easier testing.
In this commit, we randomize the order of the different bootstrappers in
order to prevent from always querying potentially unreliable
bootstrappers first.
In this commit, we fix the logging when adding new gossip syncers. The
old log would log the byte array, rather than the byte slice. We fix
this by slicing before logging.
This commit changes the gossiper to direct messages to
peer objects, instead of sending them through the
server every time. The primary motivation is to reduce
contention on the server's mutex and, more importantly,
avoid deadlocks in the Triangle of Death.
In this commit, we go through the codebase looking for TCP address
assumptions and modifying them to include the recently introduced onion
addresses. This enables us to fully support onion addresses within the
daemon.
In this commit, we fix a bug where a fallback SRV lookup would leak
information if `lnd` was set to route connections over Tor. We solve
this by using the network-specific functions rather than the standard
ones found in the `net` package.
In this commit, we fix an existing deadlock in the
gossiper->server->peer pipeline by ensuring that we're not holding the
syncer mutex while we attempt to have a syncer filter out the rest of
gossip messages.
In this commit we fix an existing bug caused by a scheduling race
condition. We'll now ensure that if we get a gossip message from a peer
before we create an instance for it, then we create one on the spot so
we can service the message. Before this commit, we would drop the first
message, and therefore never sync up with the peer at all, causing them
to miss channel announcements.
In this commit, we extend the AuthenticatedGossiper to take advantage of
the new query features in the case that it gets a channel update w/o
first receiving the full channel announcement. If this happens, we'll
attempt to find a syncer that's fully synced, and request the channel
announcement from it.
This new method allows outside callers to sample the current state of
the gossipSyncer in a concurrent-safe manner. In order to achieve this,
we now only modify the g.state variable atomically.
In this commit, we create a new concrete implementation for the new
discovery.ChannelGraphTimeSeries interface. We also export the
createChannelAnnouncement method to allow the chanSeries struct to
re-use the existing code for creating wire messages from the database
structs.
In this commit, we update the logic in the AuthenticatedGossiper to
ensure that can properly create, manage, and dispatch messages to any
gossipSyncer instances created by the server.
With this set of changes, the gossip now has complete knowledge of the
current set of peers we're conneted to that support the new range
queries. Upon initial connect, InitSyncState will be called by the
server if the new peer understands the set of gossip queries. This will
then create a new spot in the peerSyncers map for the new syncer. For
each new gossip query message, we'll then attempt to dispatch the
message directly to the gossip syncer. When the peer has disconnected,
we then expect the server to call the PruneSyncState method which will
allow us to free up the resources.
Finally, when we go to broadcast messages, we'll send the messages
directly to the peers that have gossipSyncer instances active, so they
can properly be filtered out. For those that don't we'll broadcast
directly, ensuring we skip *all* peers that have an active gossip
syncer.
In this commit, introduce a new struct, the gossipSyncer. The role of
this struct is to encapsulate the state machine required to implement
the new gossip query range feature recently added to the spec. With this
change, each peer that knows of this new feature will have a new
goroutine that will be managed by the gossiper.
Once created and started, the gossipSyncer will start to progress
through each possible state, finally ending at the chansSynced stage. In
this stage, it has synchronized state with the remote peer, and is
simply awaiting any new messages from the gossiper to send directly to
the peer. Each message will only be sent if the remote peer actually has
a set update horizon, and the message isn't before or after that
horizon.
A set of unit tests has been added to ensure that two state machines
properly terminate and synchronize channel state.
In this commit, we update the testUpdateChannelPolicy to exercise the
recent set of changes within the switch. If one applies this test to a
fresh branch (without those new changes) it should fail. This is due to
the fact that before, Bob would attempt to apply the constraints of the
incoming link (which we updated) instead of the outgoing link. With the
recent set of changes, the test now properly passes.
In this commit, we fix an existing deadlock in the
processChanPolicyUpdate method. Before this commit, within
processChanPolicyUpdate, we would directly call updateChannel *within*
the ForEachChannel closure. This would at times result in a deadlock, as
updateChannel will itself attempt to create a write transaction in order
to persist the newly updated channel.
We fix this deadlock by simply performing another loop once we know the
set of channels that we wish to update. This second loop will actually
update the channels on disk.
In this commit, fix the inability of some users to connect to the DNS
seed using our direct TCP fallback. We do this as some resolvers filter
out our large SRV requests due to their size (they also include public
keys). Instead, we’ll use a direct TCP resolution in this case.
However, after a recent change, we forgot the period at the end of the
target DNS host. This is an issue as the domain needs to be fully
qualified.
The fix is easy, add a period within our string formatting to target
the proper sub-domain and SRV target.
Fixes#854.
In this commit, we update the DNS bootstrapper to match the new query
semantics expected by the new DNS server. We no longer hard code the
target DNS host, and instead, we’ll re-use the same target endpoint as
we only need the soaShim in order to establish a direct TCP connection
for the queries.
In this commit, we reduce the amount of unnecessary work that the
gossiper can carry out. When CPU profiling some nodes, I noticed that
we’d spend a lot of time validating the signatures for an announcement,
only to realize that the router already had it.
To remedy this, we’ll use the new methods added to the channel router
in order to avoid unnecessarily validating an announcement that is
actually stale. This should reduce memory usage (since it uses big
int’s under the scenes), and also idle CPU usage.
This commit adds a new module named 'torsvc' which houses all Tor
functionality in an attempt to isolate it and make it reusable in
other projecs. Some additional tweaks were made to config.go and
to the bootstrapper.
This commit adds Tor support. Users can set the --TorSocks flag
to specify which port Tor's SOCKS5 proxy is listening on so that
lnd can connect to it. When this flag is set, ALL traffic gets
routed over Tor including DNS traffic. Special functions for
DNS lookups were added, and since Tor doesn't natively support
SRV requests, the proxySRV function routes connects us to
a DNS server via Tor and SRV requests can be issued directly
to the DNS server.
Co-authored-by: MeshCollider <dobsonsa68@gmail.com>
In order to reduce high CPU utilization during the initial network view
sync, we slash down the total number of active in-flight jobs that can
be launched.
This commit uses the multimutex.Mutex to esure database
state stays consistent when handling an announcement, by
restricting access to one goroutine per channel ID.
This fixes a bug where the goroutine would read the
database, make some decisions based on what was read,
then write its data to the database, but the read data
would be outdated at this point. For instance, an
AuthProof could have been added between reading the
database and when the decision whether to announce
the channel is made, making it not announce it.
Similarly, when receiving the AuthProof, the edge
policy could be added between reading the edge state
and adding the proof to the database, also resulting
in the edge not being announced.
This commit fixes a bug that could cause annoucements
to get lost, and resultet in flaky integration tests.
After a set of announcements was broadcastet, we would
reset (clear) the announcement batch, making any
annoucement that was added between the call to Emit()
and Reset() to be deleted, without ever being broadcast.
We can just remove the Reset() call, as the batch will
actually be reset within the call to Emit(), making
the previous call only delete those messages we hadn't
sent yet.
We no longer need to hand off new channels that come online as the
chainWatcher will be persistent, and always have an active signal for
the entire lifetime of the channel.
This commit ensures that we always increment the timestamp of
ChannelUpdates we send telling the network about changes to
our channel policy. We do this because it could happen
(especially during tests) that we issued an update, but the
ChannelUpdate would have the same timestamp as our last
ChannelUpdate, and would be ignored by the network.
