In this commit, we make the internal channel funding flow aware of
frozen channels. We also update the testSingleFunderReservationWorkflow
method to ensure that the created channels have the proper type bit set.
As frozen channels can only be created via the non-default channel
assembler, we extend both the ShimIntent and CannedAssembler to also
accept and expose this new channel status along with the thaw height.
If we are the initiator, we check that our starting balance after
subtracting fees are not less than two times the default dust limit.
This commit adds a similar check for the non-initiator case, checking
that the remote party has a starting balance of reasonable size.
We also increase the witness size for these types to account for the 3
extra bytes. The size won't be correct in all cases, but it is just an
upper bound in any case.
This commit modifies the NP2WKH and NP2WSH input tests to ensure the
input count is properly incremented and accounted for in the size
estimate. 253 is chosen because it is the lowest value that, when
serialized, occupies more than one byte on the wire.
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.
Since our HTLC must also be added to the remote commitment, we do the
balance caluclation also from the remote chain perspective and report
our minimum balance from the two commit views as our available balance.
When we send non-dust HTLCs as the non-initiator, the remote party will
have to pay the extra commitment fee. To account for this we figure out
if they can afford paying this fee, if not we report that we only have
balance available for dust HTLCs, since these HTLCs won't increase the
commitment fee.
Since we want to handle the edge case where paying the HTLC fee would
take the initiator below the reserve, we move the subtraction of the
reserve into availableBalance where this calculation will be performed.
This commit adds an extra validation step when adding HTLCs. Previously
we would only validate the remote commitment resulting from adding an
HTLC, which in most cases is enough. However, there are situations where
the dustlimits are different, which could lead to the resulting remote
commitment from adding the HTLC being valid, but not the local
commitment.
Now we also validate the local commitment. A test to trigger the case is
added.
add
To ba able to validate the commitment sanity both for remote and local
commitments, and at the same time predict both our and their add, we let
validateCommitmentSanity take an extra payment descriptor to make this
possible.
This commit fixes the TestMaxAcceptedHTLCs, TestMaxPendingAmount,
TestMinHTLC, & TestChanReserve unit tests to pass with the new
ReceiveHTLC logic. Instead of asserting specific failures upon
receiving a new commitment signature, the various assertions were
moved to assert on the error returned from ReceiveHTLC.
This commit checks the commitment sanity when receiving an HTLC so
that if a commitment transaction will overflow from an ADD, it is
caught earlier rather than in ReceiveNewCommitment.
The unit test TestNewBreachRetributionSkipsDustHtlcs triggered a state
transition from Bob, even though it was Alice that had added the HTLCs.
This is wrong since it will lead to Bob still owing Alice a commitment,
which is not accounted for in the unit tests.
We add a sanity check that the add heights has been set for all entries
found in the logs, and return an error otherwise. This won't happen
during normal operation, but it does reveal the mistake in the unit
test, which is fixed by making Alice trigger the transition.
In addition we resolve a long standing TODO by removing a (purposeful)
panic in the channel state machine. Old version of lnd had a bug that
could lead to the parent entries being lost during channel restore. A
panic was added to get to the bottom of if.
This is now fixed, so new nodes shouldn't encounter it. However, to be
on the safe side, instead of panicking we return an error back to
gracefully exit the channel state machine.
Updates were always restored with the same log index. This could cause a
crash when the logs were compacted and possibly other problems
elsewhere.
Extended unit test to cover the crash scenario.
This commit updates the channel state machine to
persistently store remote updates that we have received a
signature for, but that we haven't yet included in a commit
signature of our own.
Previously those updates were only stored in memory and
dropped across restarts. This lead to the production of
an invalid signature and channel force closure. The remote
party expects us to include those updates.
This test asserts that remote updates that are locked-in on the local
commitment, but haven't been signed for on the remote commitment, are
properly restored after a restart.
When creating the keyring, the tweak is already calculated in the remote
commitment case. We add the calculation also for our own commitment, so
we can use it in all cases without deriving the tweak.
Based on the current channel type, we derive the script used for the
to_remote output. Currently only the unencumbered p2wkh type is used,
but that will change with upcoming channel types.
To make the channel state machine less concerned about the type of
commitment, we nil the local tweak when creating the keyring, depending
on the commitment type.
We abstract away how keys are generated for the different channel types
types (currently tweak(less)).
Intention is that more of the logic that is unique for each commitment
type lives in commitment.go, making the channel state machine oblivious
to the keys and outputs being created on the commitment tx for a given
channel state.
createCommitmentTx would earlier mutate the passed commitment struct
after evaluating the htlc view and calculating the final balances, which
was confusing since the balances are supposed to only be *after*
subtracting fees.
Instead we take the needed parameters as arguments, and return the final
balances, tx and fee to populate the commitment struct in a proper way.
PURE CODE MOVE:
Moving createCommitmentTx, CreateCommitTx, createStateHintObfuscator,
CommitmentKeyRing, DeriveCommitmentKeys, addHTLC, genHtlcScripts
We move the methods and structs to a new file commitment.go in
preparation for defining all the logic that is dependent on the channel
type in this new file.
Instead of passing delays and dustlimits separately, we pass the correct
channel config to CreateCommitTx from the POV of the local party that
owns the commit tx.
To make it more clear which commitment we are actually creating, we
rename variables to denote local and remote, to prepare for the case
when both outputs might be delayed.
In this commit, we implement the currently defined transition methods
for the new `FundingStateStep` method. At this point, we're now able to
serve the "responder" of the externally initiated channel funding flow
by being able to register and cancel a funding flow according to its
expected pending channel ID.
This commit gets upfront shutdown scripts from openchannel and
acceptchannel wire messages sent from our peer and sets upfront
shutdown scripts in our open and accept channel messages when
the remote peer supports option upfront shutdown and we have
the feature enabled.
This commit adds fields for upfront shutdown scripts set
by the local and remote peer to the OpenChannel struct.
These values are optional, so they are added with their
own keys in the chanBucket in the DB.
This commit sets our close addresss to the address
specified by option upfront shutdown, if specified,
and disconnects from peers that fail to provide
their upfront shutdown address for coopertaive closes
of channels that were opened with the option set.
In this commit, we fix a long standing bug within the newly created
`verifyFundingInputs` method. Before this commit, the method would
attempt to derive the pkScript by looking at the last items on the
witness stack, and making a p2wsh output script from that. This is
incorrect as typically non of these scripts will actually be p2wsh, and
instead will be p2wkh. We fix this by using the newly available
`txscript.ComputePkScript` method to derive the proper pkScript.
This resolves an issue w.r.t passing incorrect arguments for all
backends, but an issue still stands for the neutrino backend. As is, we
pass a height hint of zero into the `GetUtxo` method call. With the way
the current utxo scanner is set up for neutrino, this'll cause it to
never find the UTXO, as it takes the height hint as a UTXO birth height,
rather than a lower bound of the birth of the UTXO.
In this commit, we add a new method `RegisterFundingIntent` that allows
a caller to "inject" a pre-populated chanfunding.Intent into a funding
workflow. As an example, if we've already agreed upon the "shape" of the
funding output _outside_ the protocol, then we can use this to pass down
the details of the output, then leverage the normal wire protocol to
carry out the remainder of the funding flow.
In this commit, we start to thread the pending channel ID from wire
protocol all the way down into the reservation context. This change will
allow negotiation to take place _outside_ the protocol that may result
in a particular chanfunding.Assembler being dispatched.
In this commit, we make the wallet aware of the second type of funding
intent: the ShimIntent. If we have one of these, then we don't need to
construct the funding transaction, and can instead just obtain the
outpoint directly from it.
In this commit, we begin to integrate the new channel funding package
into the existing codebase. With this set of changes, we'll no longer
construct and sign the funding transaction within this package, instead
delegating it to the new chanfunding package. We use the new
chanfunding.WalletAssembler to carry out all channel funding, providing
it with an implementation of all its interfaces backed by the wallet.
In this commit, we introduce a series of new abstractions for channel
funding. The end goal is to enable uses cases that construct the funding
transaction externally, eventually handing the funding outpoint to lnd.
An example of such a use case includes channel factories and external
channel funding using a hardware wallet.
We also add a new chanfunding.Assembler meant to allow external channel
funding in contexts similar to how channel factories
can be constructed. With this channel funder, we'll only obtain the
channel point and funding output from it, as this alone is enough to
carry out a funding flow as normal.
In this commit, we make an incremental change to move the existing coin
selection code into a new chanfunding package. In later commits, this
package will grow to serve all the lower level channel funding needs in
the daemon.
Instead of tracking local updates in a separate link variable, query
this state from the channel itself.
This commit also fixes the issue where the commit tx was not updated
anymore after a failed first attempt because the revocation window was
closed. Also those pending updates will be taken into account when the
remote party revokes.
Previously the channel method FullySynced was used to decide whether to
send a new commit sig message. However, it could happen that FullySynced
was false, but that we didn't owe a commitment signature. Instead we
were waiting on the other party to send us a signature. If that
happened, we'd send out an empty commit sig. This commit modifies the
condition that triggers a new commit sig and fixes this deviation from
the spec.
To facilitate the logging, this commit adds a new OweCommitment method.
For the logging, we only need to consider the remote perspective. In a
later commit, we'll also start using the local perspective to support
the decision to send another signature.
In this commit, we create a new chainfee package, that houses all fee
related functionality used within the codebase. The creation of this new
package furthers our long-term goal of extracting functionality from the
bloated `lnwallet` package into new distinct packages. Additionally,
this new packages resolves a class of import cycle that could arise if a
new package that was imported by something in `lnwallet` wanted to use
the existing fee related functions in the prior `lnwallet` package.
In this commit, we convert the existing `channeldb.ChannelType` type
into a _bit field_. This doesn't require us to change the current
serialization or interpretation or the type as it is, since all the
current defined values us a distinct bit. This PR lays the ground work
for any future changes that may introduce new channel types (like anchor
outputs), and also any changes that may modify the existing invariants
around channels (if we're the initiator, we always have the funding
transaction).
