This adds the scenario to the local force close test cases where a node
force closes one of its channels, then lose state (or do recovery)
before the commmitment is confirmed. Without the previous commit this
would go undetected.
The tests didn't really roll back the channel state, so we would only
rely on the state number to determine whether we had lost state. Now we
properly roll back the channel to a previous state, in preparation for
upcoming changes.
In this commit, we update the funding workflow to be aware of the new
channel type that doesn't tweak the remote party's output within the
non-delay script on their commitment transaction. To do this, we now
allow the caller of `InnitChannelReservation` to signal if they want the
old or new (tweakless) commitment style.
The funding tests are also updated to test both funding variants, as
we'll still need to understand the legacy format for older nodes.
In this commit, we fix a lingering TOOD statement in the channel arb.
Before this commitment, we would simply wipe our our local HTLC set of
the HTLC set that was on the remote commitment transaction on force
close. This was incorrect as if our commitment transaction had an HTLC
that the remote commitment didn't, then we would fail to cancel that
back, and cause both channels to time out on chain.
In order to remedy this, we introduce a new `HtlcSetKey` struct to track
all 3 possible in-flight set of HTLCs: ours, theirs, and their pending.
We also we start to tack on additional data to all the unilateral close
messages we send to subscribers. This new data is the CommitSet, or the
set of valid commitments at channel closure time. This new information
will be used by the channel arb in an upcoming commit to ensure it will
cancel back HTLCs in the case of split commitment state.
Finally, we start to thread through an optional *CommitSet to the
advanceState method. This additional information will give the channel
arb addition information it needs to ensure it properly cancels back
HTLCs that are about to time out or may time out depending on which
commitment is played.
Within the htlcswitch pakage, we modify the `SignNextCommitment` method
to return the new set of pending HTLCs for the remote party's commitment
transaction and `ReceiveRevocation` to return the latest set of
commitment transactions on the remote party's commitment as well. This
is a preparatory change which is part of a larger change to address a
lingering TODO in the cnct.
Additionally, rather than just send of the set of HTLCs after the we
revoke, we'll also send of the set of HTLCs after the remote party
revokes, and we create a pending commitment state for it.
In this commit, we modify the way we detect local force closes. Before
this commit, we would directly check the broadcast commitment's txid
against what we know to be our best local commitment. In the case of DLP
recovery from an SCB, it's possible that the user force closed, _then_
attempted to recover their channels. As a result, we need to check the
outputs directly in order to also handle this rare, but
possible recovery scenario.
The new detection method uses the outputs to detect if it's a local
commitment or not. Based on the state number, we'll re-derive the
expected scripts, and check to see if they're on the commitment. If not,
then we know it's a remote force close. A new test has been added to
exercise this new behavior, ensuring we catch local closes where we have
and don't have a direct output.
In this commit, we speed up the `TestChainWatcherDataLossProtect`
_considerably_ by enumerating relevant tests using table driven tests
rather than generating random tests via the `testing/quick` package.
Each of these test cases are also run in parallel bringing down the
execution time of this test from a few minutes, to a few seconds.
In this commit, we add a new test case to exercise the way we handle the
DLP detection and dispatch within the chain watcher. Briefly, we use
the `testing/quick` package to ensure that the following invariant is
always held: "if we do N state updates, then state M is broadcast, iff M
> N, we'll execute the DLP protocol". We limit the number of iterations
to 10 for now, as the tests can take a bit of time to execute, since it
actually does proper state transitions.
