Commit Graph

171 Commits

Author SHA1 Message Date
Johan T. Halseth
ec93bf581d
contractcourt test: add TestChannelArbitratorLocalForceDoubleSpend
This commit adds a test for the case where the ChannelArbitrator fails
to broadcast its commitment during a force close because of
ErrDoubleSpend. We test that in this case it will still wait for a
commitment getting confirmed in-chain, then resolve.
2018-05-14 14:21:06 +02:00
Conner Fromknecht
f963f91a3c
multi: use mutex-guarded ShortChanID() on OpenChannel 2018-05-09 16:06:49 -07:00
Olaoluwa Osuntokun
7af699f3a7
contractcourt: update chain watcher tests to latest API 2018-05-03 21:29:30 -07:00
Olaoluwa Osuntokun
a3227ba147
contractcourt: add two new tests to ensure the chainWatcher is able to play all remote commitments 2018-05-03 21:29:29 -07:00
Olaoluwa Osuntokun
c8b15719f2
contractcourt: ensure the chainWatcher is able to play all remote commitments 2018-05-03 21:29:29 -07:00
Johan T. Halseth
f06797ab00
contractcourt/chain_arbitrator: make breachArbiter handoff a function closure
This commit adds the new function closure option ContractBreach to the
ChainArbitrator config, a closure that is again used by the ChainWatcher
to reliably handoff a breach event to the breachArbiter.
2018-05-02 08:43:31 +02:00
Johan T. Halseth
3fdc04dff0
contractcourt/chain_watcher: make breachArbiter handoff a function closure
This commit changes how the ChainWatcher notifies the breachArbiter
about a channel breach. Instead of assuming the breachArbiter is among
the clients subscibing to channel events, it will call a new method
contractBreach(), and assume the breachArbiter has reliably gotten the
breach info when this method returns with a non-nil error.

Since the breachArbiter was the only sybsystem having a sync chain
subsciption, we also remove the (now) unused syncDispatch option.
2018-05-02 08:43:31 +02:00
Johan T. Halseth
a6f0dd72ac
contractcourt/chain_arbitrator: use chainWatcherConfig 2018-05-02 08:43:31 +02:00
Johan T. Halseth
0697510884
contractcourt/chain_watcher: create chainWatcherConfig 2018-05-02 08:43:31 +02:00
Johan T. Halseth
79341fc63e
contractcourt/chain_watcher: move log message
This move the log message "channel marked pending-closed" to the point
where the channel actually has been marked pending closed, instead of
before the database transaction has been done.
2018-05-02 08:43:30 +02:00
Johan T. Halseth
7e397067f6
contractcourt/chainwatcher: remove close observer for loop
This commit removes the for loop in the closeObserver, as it wasn't
serving any purpose. After receiving a spend notification we would
return, breaking out of the loop. When getting a quit signal we would
also return, making the loop only do one iteration in any case.
2018-05-02 08:43:30 +02:00
Johan T. Halseth
4320421110
contractcourt/chain_watcher: don't delete syncDispatch clients on Cancel()
This commit makes clients subscribing to channel events that are marked
"sync dispatch" _not_ being deleted from the list of clients when they
call Cancel(). Instead a go routine will be launched that will send an
error on every read of the ProcessACK channel.

This fixes a race in handing off the breach info while lnd was shutting
down. The breach arbiter could end up being shut down (and calling
Cancel()) before while the ChainWatcher was in the process of
dispatching a breach. Since the breach arbiter no longer was among the
registered clients at this point, the ChainWatcher would assume the
breach was handed off successfully, and mark the channel as pending
closed. When lnd now was restarted, the breach arbiter would not know
about the breach, and the ChainWatcher wouldn't attempt to re-dispatch,
as it was already marked as pending closed.
2018-04-25 09:37:26 +02:00
Johan T. Halseth
ddf62bbeea
contractcourt/channel_arbitrator: remove unused transationTrigger 2018-04-25 09:37:25 +02:00
Johan T. Halseth
b2949bd728
contractcourt/channel_arbitrator test: add unit tests
This commit adds MVP unit tests for the following scenarios in the
ChannelArbitrator:
1) A cooperative close is confirmed.
2) A remote force close is confirmed.
3) A local force close is requested and confirmed.
4) A local force close is requested, but a remote force close gets
confirmed.
2018-04-25 09:37:25 +02:00
Johan T. Halseth
84f06959f3
contractcourt/chain_arbitrator: remove CloseChannel method from ChannelArbitrator config 2018-04-25 09:37:25 +02:00
Johan T. Halseth
5f1da5b5f4
contractcourt/channel_arbitrator: remove unused CloseChannel method from config 2018-04-25 09:37:24 +02:00
Johan T. Halseth
70e8087731
contractcourt/channel_arbitrator: mark channel commitment broadcasted instead of closed after broadcast 2018-04-25 09:37:24 +02:00
Johan T. Halseth
854e73b8e0
contractcourt/chain_watcher: register for confirmed spend, mark closed when detected
This commit changes the ChainWatcher to only send a chain event in case
the various spends are _confirmed_ on-chain, not only seen on the
network.

A consequence of this is that we now give the ChainWatcher the
responsibility of marking the channel closed when the closing tx is
confirmed, instead of the ChannelArbitrator.
2018-04-25 09:37:24 +02:00
Johan T. Halseth
1265c9cc99
contractcourt/chain_arbitrator: add MarkCommitmentBroadcasted to ChanArb cfg 2018-04-25 09:37:24 +02:00
Johan T. Halseth
d2d87758f7
contractcourt/channel_arbitrator: only act on close signal from chain_watcher
This commit changes the channel arbitrator state machine to only care
about commitment transactions that are being confirmed on-chain
according to the chain_watcher. This is meant to handles the cases where
we would broadcast our commitment, expecting it to get confirmed, but
instead a competing transaction was confirmed.

This commit readies the ChannelArbitrator state machine for the change
that will make the ChainWatcher only notify on confirmed commitments.

The state machine has gotten a new state, StateCommitmentBroadcasted,
which we'll transition to after we have broadcasted our own commitment.
From this state we'll go to the StateContractClosed state regardless of
which commitment the ChainWatcher notifies about, unifying the contract
resolution betweee the local and remote force close.
2018-04-25 09:37:23 +02:00
Johan T. Halseth
a60e621b5f
contractcourt/channel_arbitrator: specify that height is triggerHeight, advance from height of event not current height 2018-04-25 09:37:23 +02:00
Johan T. Halseth
40b8cf0adb
contractcourt/channel_arbitrator: rename UnilateralClose -> RemoteUnilateralClose 2018-04-25 09:37:22 +02:00
Johan T. Halseth
49f4a70e5a
contractcourt/chain_watcher: add dispatchLocalForceClose
This commit adds a new method dispatchLocalClose, which will be called
in case our commitment is detected to spend the funding transaction. In
this case LocalUnilateralCloseInfo will be sent on the
LocalUnilateralClosure channel to all subscribers.

The UnilateralClosure channel is renamed to RemoteUnilateralClosure for
consistency.
2018-04-25 09:37:22 +02:00
Johan T. Halseth
7bacdd65dc
contractcourt: define StateCommitmentBroadcasted 2018-04-25 09:37:22 +02:00
Johan T. Halseth
24e8bace9c
contractcourt/channel_arbitrator: add missing return after forceClose request 2018-04-25 09:37:21 +02:00
Johan T. Halseth
0b2e6d1776
contractcourt/channel_arbitrator: removed unused bestHash parameter 2018-04-25 09:37:21 +02:00
Johan T. Halseth
9b9fada675
contractcourt: remove unecessary contractRes check
This commit removes a short circuit checking if the contract resolver
after a unilateral close is empty. After removing this, the state
machine will advance the state from StateDefault->ContractClosed, in
which the stateCallback will be called, logging the state needed to
advance. Since this logged state is empty, the state machine will go
directly to StateFullyResolved, which will trigger the
MarkChannelResolved call. This means the behaviour is kept.
2018-04-25 09:37:21 +02:00
Dimitris Tsapakidis
4009f7f874 multi: fix typos in comments 2018-04-17 19:03:27 -07:00
practicalswift
663c396235 multi: fix a-vs-an typos 2018-04-17 19:02:04 -07:00
Olaoluwa Osuntokun
09291d6aeb
contractcourt: ensure the closeObserver exits on quit 2018-04-16 17:28:48 -07:00
Olaoluwa Osuntokun
5f0d07e485
Merge pull request #1089 from halseth/resolvecontract-missing-return-on-exit
Add missing return on exit to resolveContract
2018-04-13 14:23:13 -07:00
Johan T. Halseth
c5169a79f5
contractcourt/channel_arbitrator: add missing return on resolver exit
This commit adds a missing return to the resolveContract method, that
will ensure the goroutine exits if the ChannelArbitrator shuts down.
This fixes a potential deadlock during the integration tests.

We also promote some of the logs to Debug from Trace.
2018-04-13 11:33:09 +02:00
Olaoluwa Osuntokun
aaa8fa33b1
contractcourt: when creating resolveContract closure don't bind to loop variable
In this commit, we fix a long standing bug where at times a co-op
channel closure wouldn't be properly marked as fully closed in the
database. The culprit was a re-occurring code flaw we've seen many times
in the codebase: a closure variable that closes over a loop iterator
variable. Before this instance, I assumed that this could only pop up
when goroutines bind to the loop iterator within a  closure. However,
this instance is the exact same issue, but within a regular closure that
has _delayed_ execution. As the closure doesn't execute until long after
the loop has finished executing, it may still be holding onto the _last_
item the loop iterator variable was assigned to.

The fix for this issue is very simple: re-assign the channel point
before creating the closure. Without this fix, we would go to call
db.MarkChanFullyClosed on a channel that may not have yet actually be in
the pending close state, causing all executions to fail.

Fixes #1054.
Fixes #1056.
Fixes #1075.
2018-04-12 18:54:33 -07:00
Olaoluwa Osuntokun
7a13378671
channeldb+contractcourt: add additional logging around co-op channel closes 2018-04-12 17:13:37 -07:00
Conner Fromknecht
218293db4a
contractcourt/chain_watcher: release mutex on return 2018-04-11 14:50:05 -07:00
Olaoluwa Osuntokun
bc029b9cd4
contractcourt: properly log error if unable to update chan close state 2018-04-10 16:55:32 -07:00
Johan T. Halseth
8e77e1e6eb
lnwallet/channel: add NewLocalForceCloseSummary
This commit renames ForceCloseSummary to LocalForceCloseSummary, and
adds a new method NewLocalForceCloseSummary that can be used to derive a
LocalForceCloseSummary if our commitment transaction gets confirmed
in-chain. It is meant to accompany the NewUnilateralCloseSummary method,
which is used for the same purpose in the event of a remote commitment
being seen in-chain.
2018-04-06 09:46:30 +02:00
Johan T. Halseth
8b02064c7b
multi: provide mempool=true to RegisterSpendNtfn 2018-04-03 11:24:07 +02:00
Olaoluwa Osuntokun
a0fe4fb716
Merge pull request #968 from halseth/chanarb-doublespend
contractcourt/channel_arbitrator: ignore ErrDoubleSpend on force close
2018-03-29 16:11:38 -07:00
Johan T. Halseth
d216416db8
contractcourt/channel_arbitrator: ignore ErrDoubleSpend on force close
This commit mitigates a problem within the ChannelArbitrator, where
after a restart we would start up in the state StateBroadcastCommit but
fail to broadcast out commitment because a conflicting transaction (most
likely our own commitment) was already broadcast. A more complete fix
for this case will be added later, but this commit let the
ChannelArbitrator continue, trying to close out the channel.
2018-03-29 11:15:41 +02:00
Johan T. Halseth
5bf5a823ff
contractcourt/chain_watcher: don't print curve of DoubleTweak 2018-03-29 11:11:54 +02:00
Olaoluwa Osuntokun
800eea931f
build+multi: switch from bolt to bbolt
In this commit, we switch from boltbd/bolt to coreos/bbolt as the
former is no longer being actively maintained.
2018-03-10 19:01:13 -08:00
Olaoluwa Osuntokun
dc2404f289
contractcourt: update test due to recent SignDescriptor API changes 2018-03-06 16:04:06 -05:00
Olaoluwa Osuntokun
4b20e805fe
multi: update packages due to recent SignDescriptor and WalletController changes 2018-03-06 16:04:03 -05:00
Johan T. Halseth
166637bb55
contractcourt: use vsize fee estimate and new fee rate types 2018-02-26 22:42:25 +01:00
Johan T. Halseth
2ae1b7dbbe
contractcourt: remove TODO for checking double spends from PublishTx 2018-02-14 12:34:41 +01:00
Daniel McNally
8543497dcc multi: fixing it's/its typos in comments 2018-02-06 19:13:07 -08:00
practicalswift
a93736d21e multi: comprehensive typo fixes across all packages 2018-02-06 19:11:11 -08:00
Olaoluwa Osuntokun
2099d6fa77
contractcourt: ensure we always cancel block epoch notifications after use
In this commit, we fix an existing grouting leak within the contract
court package. If a goroutine dies, but it doesn’t actually cancel the
block epoch notification that it requested, then it’s possible to leak
thousands of gorutines. To remedy this situation, we ensure that we’ll
*always* cancel the epoch notification once the goroutine has exited.
2018-02-05 14:41:08 -08:00
Olaoluwa Osuntokun
2d104b7ec0
test: wait for 2 transactions to enter mempool at the end of testMultiHopHtlcRemoteChainClaim
In this commit, we fix an existing flake on Travis related to the new
set of on-chain HTLC tests. In this timing flake, Bob would broadcast
his sweeping transaction, but *mid block mining*. As a result, the
output would never be properly swept, needing an additional block to be
mined. We’ll now wait for both Bob’s sweeping transaction, and Carol’s
sweep transaction to be confirmed before we attempt our assertions.
2018-01-23 19:05:36 -08:00
Olaoluwa Osuntokun
5dc0d669a6
contractcourt: watch proper output within htlcOutgoingContestResolver
In this commit, we fix an existing bug in the implementation of the
resolution of the htlcOutgoingContestResolver. Before this commit, we
would _always_ watch the claim outpoint. However, if this is on the
remote party’s commitment transaction, then we would end up watching
the wrong output. We’ll now properly detect this by modifying which
output we watch, based on if we have a second level transaction or not.
2018-01-23 14:16:22 -08:00
Olaoluwa Osuntokun
f8adab1f1c
test: add comprehensive integration tests for on-chain HTLC handling
In this commit, we add 6 new integration tests to test the various
actions that may need to be performed when either side goes on-chain to
fully resolve HTLC’s. Many of the tests are mirrors of each other as
they test sweeping/resolving HTLC’s from both commitment transactions.
2018-01-22 19:20:02 -08:00
Olaoluwa Osuntokun
73641d222f
contractcourt: properly use the broadcast state number during breach remedy 2018-01-22 19:19:58 -08:00
Olaoluwa Osuntokun
5df6704a9c
contractcourt: make synchronous chain watcher notifications optional
In this commit, we modify the way that notifications are dispatched
within the chainWatcher. Before we would *always* wait for an ack back
before we started to clean up he database state. This would at times
lead to deadlocks. To remedy this, we now allow callers to decide if
they want notifications to be sync or not. The only current caller that
requires this is the breach arbiter.
2018-01-22 19:19:58 -08:00
Olaoluwa Osuntokun
783f01e1c7
multi: fix linter warnings 2018-01-22 19:19:56 -08:00
Olaoluwa Osuntokun
91d45b37ba
contractcourt: on startup, launch a goroutine to finalize co-op chan close if needed 2018-01-22 19:19:54 -08:00
Olaoluwa Osuntokun
db2b9fd9ff
contractcourt: remove the existing ManuallyResolveChannel methiod
We’re removing this method as it’s no longer needed, since the
chainWatcher will properly handle on-chain co-op closes.
2018-01-22 19:19:54 -08:00
Olaoluwa Osuntokun
3ec83cc82f
peer+contractcourt: delegate watching for co-op closes to the chainWatcher
In this commit, we modify the interaction between the chanCloser
sub-system and the chain notifier all together. This fixes a series of
bugs as before this commit, we wouldn’t be able to detect if the remote
party actually broadcasted *any* of the transactions that we signed off
upon. This would be rejected to the user by having a “zombie” channel
close that would never actually be resolved.

Rather than the chanCloser watching for on-chain closes, we’ll now open
up a co-op close context to the chainWatcher (via a layer of
indirection via the ChainArbitrator), and report to it all possible
closes that we’ve signed. The chainWatcher will then be able to launch
a goroutine to properly update the database state once any of the
possible closure transactions confirms.
2018-01-22 19:19:53 -08:00
Olaoluwa Osuntokun
bbca53507f
contractcourt: extend the ChainArbitratorConfig with IsOurAddress closure
In this commit, we add the IsOurAddress field into the config of the
chain arb. With this new function closure, the chain arb is able to
detect co-op on chain closes automatically.
2018-01-22 19:19:53 -08:00
Olaoluwa Osuntokun
bdbb33344a
contractcourt: extend resolveContract to also stop any active chainWatcher 2018-01-22 19:19:52 -08:00
Olaoluwa Osuntokun
723bfb0eac
contractcourt: channel arbitrators now exit on co-op close of the channel 2018-01-22 19:19:52 -08:00
Olaoluwa Osuntokun
62f951a969
contractcourt: extend the chainWatcher to be able to detect co-op closes
In this commit, we extend the chainWatcher to be able to automatically
detect co-op closes of the channel. With this change, it’s now fully
encompassed so able to detect all types of closes on-chain. We detect a
co-op close due to the sequence number being finalized, as well as
paying to us directly in a regular p2wkh-like output.
2018-01-22 19:19:52 -08:00
Olaoluwa Osuntokun
b5ae0855d2
contractcourt: add new SubscribeChannelEvents method to ChainArbitrator
In this commit, we add a new method to allow external sub-systems to
gain an intent to receive notifications once an on-chain event happens.
This will be used in place of the old channel signals directly on the
channel state machine object in a series of follow up commits.
2018-01-22 19:19:49 -08:00
Olaoluwa Osuntokun
754d1c1c38
contractcourt: when handling a remote force close, use their view of the HTLC's 2018-01-22 19:19:49 -08:00
Olaoluwa Osuntokun
63f7bf4e65
contractcourt: integrate notifications of the chainWatcher with each channel arb
In this commit, we modify the construction of the channel arbitrator to
accept a pointer to an event stream from the chain watcher that’s been
assigned to that channel. As a result, we no longer need a fresh
unilateral close signal, as the one we get from the chain watcher will
*always* be up to date.

For each active channel, we’ll now create a chainWatcher instance that
will be around until the channel is fully closed on chain.
2018-01-22 19:19:48 -08:00
Olaoluwa Osuntokun
0e14ac2063
contractcourt: add new chainWatcher struct
In this commit, we add a new struct to the package, the chainWatcher.
The duty of this struct is to replace the functionality that was
previously implemented by the closeObserver of each channel. Rather
than the source of notification being tied to the lifetime of a
particular object, it’s now delegated to a persistent object that will
be around for the entire lifetime of the channel (until it’s closed).
This will serve to greatly simplify the code, and eliminate a large
class of bugs.
2018-01-22 19:19:48 -08:00
Olaoluwa Osuntokun
31aa7265b7
contractcourt: add new ChainArbitrator struct as central coordinator of package
In this commit, we add the ChainArbitrator struct. The ChainArbitrator
is a special sub-system that will oversee the on-chain resolution of
all active channels, and also channels that are in the pending close
state. The ChainArbitrator maintains a set of ChannelArbitrators, one
for each channel that hasn’t yet been fully resolved.

Outside sub-systems should send new channels to the arbitrator once
they’ve opened. Additionally, they can also trigger manual
interventions to close out a channel on chain forcibly, or just to
signal that a channel has been closed cooperatively.

Finally, (for now) the ChainArbitrator should be notified once a fresh
set of signals for a channel becomes available. The ChannelArbitrator
for the channel will use these set of signals to be notified when an
on-chain event happens.
2018-01-22 19:19:36 -08:00
Olaoluwa Osuntokun
09b6bee8d4
contractcourt: add complete ContractResolver implementations
In this commit, we introduce a new interface, the ContractResolver. The
duty of a ContractResolver is to watch a contract on-chain, for all
possible transitions, and exit finally when the contract has been fully
resolved. Resolvers themselves can be recursive: meaning producing
another resolver to hand off the duties require to fully resolve a
contract.

Each resolver also has a ResolverKit which contains all the function
closures and interfaces that the resolver need to properly do its job.

The 5 types of resolvers are:
  * outgoing HTLC timeout
  * outgoing HTLC contested
  * incoming HTLC know presage
  * incoming HTLC contested (don’t yet know)
  * commitment sweep

In the future, more advanced resolver types can be added as required.
2018-01-22 19:19:36 -08:00
Olaoluwa Osuntokun
701eb9d4f4
contractcourt: add new briefcase.go file to house persistent arbitrator state
In this commit, we add a new file: briefcase.go. The contents of this
file are the ArbitratorLog. This log will be used by the internal state
machine of each Channel Arbitrator to ensure that each state transition
is fully reflected on-disk, to ensure that the state machine is durable
and able to survive restarts.

This commit also adds a new implementation of the ArbitratorLog
interface backed by boltdb.
2018-01-22 19:19:35 -08:00
Olaoluwa Osuntokun
d64ffcb6c8
contractcourt: add new ChannelArbitrator struct
In this commit, we add the primary struct of the package with a full
implementation. The duty of the ChannelArbitrator is to watch the set
of active contracts on a comment transaction and act accordingly if any
of their redemption criteria have been met. Potential criteria include:
an HTLC about to time out, and HTLC about to time out that we know the
preiamge to, or the remote party going to chain (forcing us to resolve
all pending contracts on chain).

The primary goroutine of this struct implements a persistent state
machine in order to ensure that mid contract resolution, we’re able to
properly survive restarts without losing our place, or forgetting about
a pending contract.

A ChannelArbitrator will stay alive until all contracts have been fully
resolved. This means that outside sub-systems no longer need to worry
about remembering to mark a channel as fully resolved, as it’s the job
of the ChannelArbitrator to do this task.
2018-01-22 19:19:34 -08:00
Olaoluwa Osuntokun
71009438b6
contractcourt: create new package, add logger 2018-01-22 19:19:34 -08:00