In this commit, we made the change so that when sweeping anchors for the
commitment transactions, we will be aware of the deadline which is
derived from its HTLC set. It's very likely we will use a much larger
conf target from now on, and save us some sats.
This commit adds a new struct AnchorResolutions which wraps the anchor
resolutions for local/remote/pending remote commitment transactions. It
is then returned from NewAnchorResolutions. Thus the caller knows how to
retrieve a certain anchor resolution.
To allow us to grab all of the information we need for our channel arbs
in a more efficient way on startup, we add an optional tx to our lookup
functions required on start.
For unconfirmed commit tx anchors, supply the sweeper with cpfp info and
a confirmation target fee estimate.
The sweeper will try to pay for the parent commit tx as long as the
current fee estimate exceeds the pre-signed commit tx fee rate.
Extend the fee estimator to take into account parent transactions with
their weights and fees.
Do not try to cpfp parent transactions that have a higher fee rate than
the sweep tx fee rate.
Follow up labelling of external transactions with labels for the
transaction types we create within lnd. Since these labels will live
a life of string matching, a version number and rigid format is added
so that string matching is less painful. We start out with channel ID,
where available, and a transaction "type". External labels, added in a
previous PR, are not updated to this new versioned label because they
are not lnd-initiated transactions. Label matching can check this case,
then check for a version number.
Our current set of reports contain much of the information we will
need to persist contract resolutions. We add a function to create
resolver reports from our exiting set of resolutions.
To allow us to write the outcome of our resolver to disk, we add
optional resolver reports to the CheckPoint function. Variadic params
are used because some checkpoints may have no reports (when the resolver
is not yet complete) and some may have two (in the case of a two stage
resolution).
Previously it wasn't possible to store a preimage in the invoice
database and signal that a payment should not be settled right away. The
only way to hold a payment was to insert the magic UnknownPreimage value
in the invoice database. This commit introduces a distinct flag to
signal that an invoice is a hold invoice and thereby allows the preimage
to be present in the database already.
Preparation for (key send) hodl invoices for which we already know the
preimage.
Add label parameter to PublishTransaction in WalletController
interface. A labels package is added to store generic labels that are
used for the different types of transactions that are published by lnd.
To keep commit size down, the two endpoints that require a label
parameter be passed down have a todo added, which will be removed in
subsequent commits.
Sweeping anchors and being able to bump the fee was already added in a
previous commit. This commit extends anchor sweeping with an anchor
resolver object that becomes active after the commitment tx confirms.
At that point, the anchors do not serve the purpose of getting the
commitment tranaction confirmed anymore. It is however still possible to
reclaim some of their value if using a low fee rate.
Preparation for anchor resolver. The recovered anchor amount should
still be included in the pending channel report even after it has been
resolved.
This also fixes an existing bug that in some cases caused the recovered
amount from an htlc resolver not to be included in the total.
Start anchor sweep attempts immediately after the commitment transaction
has been published. This makes the anchor known to the sweeper and
allows the user to bump the fee on it to get their commitment
transaction confirmed in case the fee committed too is insufficient for
timely confirmation.
Prior to this change, the trigger height for closed channels was set to
the current best block height. As this height is in some cases used as a
height hint, the spend may have been missed.
This commit adds two new channel statuses which indicate the party that
initatited closing the channel. These statuses are set in conjunction
with the existing commit broadcast status so that we do not need to
migrate existing logic to handle multiple types of closes. This status
is set for locally initiated force closes in this commit because they
follow a similar pattern to cooparative closes, marking the commitment
broadcast then proceeding with tx broadcast. Remote force closes are
added in the following commit, as they are handled differently.
This commit enables the user to specify he is not interested in
automatically close channels with pending payments that their
corresponding htlcs have timed-out.
By requiring a configurable grace period uptime of our node
before closing such channels, we give a chance to the other node to
properly cancel the htlc and avoid unnecessary on-chain transaction.
In mobile it is very important for the user experience as otherwise
channels will be force closed more frequently.
This commit changes the shouldGoOnChain signature to get the htlc
as parameter. I will allow the function to take decisions based on
whether the htlc is Incoming or Outgoing.
The channel arbitrator no longer passes the direct commitment output to
the nursery for incubation. Instead the resolver itself will await the
csv lock if any.
The reason to change this now is to prevent having to deal with the
(legacy) nursery code for a planned anchor outputs related change to the
commit sweep resolver (also csv lock to_remote).
It is no problem if there are any lingering incubating outputs at the
time of upgrade. This just means that the output will be offered twice
to the sweeper and this doesn't hurt.
In this commit, we fix a bug that would prevent users that had
unresolved contracts at the time of update from starting their nodes.
Before we added the conf commit set, the information needed to
supplement the resolvers was found in the chain action map. As a result,
if the conf commit set is nil, then we also need to check this legacy
data to ensure that we can supplement the resolvers to the best of our
ability based on the available data.
Fixes#3549.
In this commit, we fix an existing bug in the package, causing
resolutions to be restarted without their required supplementary
information. This can happen if a distinct HTLC set gets confirmed
compared to the HTLCs that we may have had our commitment at time of
close. Due to this bug, on restart certain HTLCS would be rejected as
they would present their state to the invoice registry, but be rejected
due to checks such as amount value.
To fix this, we'll now pass in the set of confirmed HTLCs into the
resolvers when we re-launch them, giving us access to all the
information we need to supplement the HTLCS.
We also add a new test that ensures that the proper fields of a resolver
are set after a restart.
Before publishing the close tx to the network and commit to the
StateCommitmentBroadcasted state, we mark the commitment as broadcasted
and store it to the db. This ensures it will get re-published on startup
if we go down.
Earlier the channel arbitrator would fail to recognize channels pending
close that were in the breached state. This lead to the state machine
not progressing correctly, and in some cases crashing since we would
attempt to force close an already closed channel.
A test TestChannelArbitratorForceCloseBreachedChannel is added to
exercise one of these scenarios.
Earlier we would not react to breaches, as these are handled by other
subsystems. Now we advances our state machine in case of breach, such
that we'll gracefully exit, and won't have leftover state in case of a
restart.
A simple test TestChannelArbitratorBreachClose to exercise this behavior
is added.
This commit fixes the 'unable to find incoming resolution' error that
occured when trying to resolve incoming htlcs below the dust limit that
are not actually present on the commitment tx.
Previously the invoice registry wasn't aware of replayed htlcs. This was
dealt with by keeping the invoice accept/settle logic idempotent, so
that a replay wouldn't have an effect.
This mechanism has two limitations:
1. No accurate tracking of the total amount paid to an invoice. The total
amount couldn't just be increased with every htlc received, because it
could be a replay which would lead to counting the htlc amount multiple
times. Therefore the total amount was set to the amount of the first
htlc that was received, even though there may have been multiple htlcs
paying to the invoice.
2. Impossible to check htlc expiry consistently for hodl invoices. When
an htlc is new, its expiry needs to be checked against the invoice cltv
delta. But for a replay, that check must be skipped. The htlc was
accepted in time, the invoice was moved to the accepted state and a
replay some blocks later shouldn't lead to that htlc being cancelled.
Because the invoice registry couldn't recognize replays, it stopped
checking htlc expiry heights when the invoice reached the accepted
state. This prevents hold htlcs from being cancelled after a restart.
But unfortunately this also caused additional htlcs to be accepted on an
already accepted invoice without their expiry being checked.
In this commit, the invoice registry starts to persistently track htlcs
so that replays can be recognized. For replays, an htlc resolution
action is returned early. This fixes both limitations mentioned above.
