To be spec compliant, we require the initiator to not pay the anchor
values into fees on coop close. We extract the balance calculation into
commitment.go, and add back the value of the anchors to the initiator's
balance.
Externally funded channels are expected by the user and explicitly
registered through the use of a funding shim and should therefore not
count towards the max pending channel count which is primarily there to
mitigate DoS attacks.
Previously whether or not to add test htlcs was implictly controlled by
a nil value of the HtlcDescs test parameter. With the conversion to
json, that nil value got lost.
The reason that the test still passed is because with the fee rate of
the no-htlc test case, the htlcs were trimmed. Also because in the test
json, balances are specified after applying htlcs, the test didn't fail
with a mismatching balance.
In this commit, we make a new wrapper method around the internal
`WalletController` method to ensure it holds the coin select mutex while
the balance is being computed.
This commit includes a regression test that checks that we remember
to restore updates that we sent to the peer but they haven't sent
us a signature for yet.
This fixes a long-standing force close bug. When we receive a
revocation, store the updates that the remote should sign next under
a new database key. Previously, these were not persisted which would
lead to force closure.
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.
Previously, we could sign a pending commitment for the remote party,
disconnect, and not restore these signed remote updates as having been
removed at the pending commitment height. This commit fixes that to
look up whether the update under the unsigned acked updates key is
present on the pending commitment or not and appropriately set
the remove commit heights.
This commit moves the deletion of all updates under the unsigned
acked updates key from AppendRemoteCommitChain to
AdvanceCommitChainTail. This is done because if we went down after
signing for these updates but before receiving a revocation, we would
incorrectly reject their commitment signature:
Alice Bob
-----add----->
-----sig----->
<----rev------
<----sig------
-----rev----->
<----fail-----
<----sig------
-----rev----->
-----sig----->
*reconnect*
<----rev------
<----add------
x----sig------
It is also important to note that filtering is required when we
receive a revocation to ensure that we aren't erroneously deleting
remote updates. Take the following state transitions:
Alice Bob
-----add----->
-----sig----->
<----rev------
<----sig------
-----rev----->
-----add----->
-----sig----->
<----fail-----
<----sig------
-----rev-----> (alice stores updates here)
<----rev------
In the above case, if Alice deleted all updates rather than filtering
when receiving the final revocation from Bob, then Alice would have
to force close the channel due to missing updates. Since Alice hasn't
signed for any of the unsigned acked updates, she should not filter any
of them out.
The `restoreStateLogs` function now properly restores the
`addCommitHeightLocal` field of a settle or fail's parent add.
Previously, any updates' parent in unsignedAckedUpdates would have
the field set to the default value of 0. This would cause a force
closure when receiving a commitment due to our belt-and-suspenders
checks for update logs during commitment validation.
The bug in question occurs because the `addCommitHeightLocal` field
is only populated for a restored add if the add is on the local
commitment. `TestChannelRestoreCommitHeight` is expanded in
`lnwallet/channel_test.go` to demonstrate restoration now works.
The faulty state transition:
```
<----fail----
<----sig-----
-----rev----> (add no longer on Alice's commitment)
*Alice restores* (addCommitHeightLocal of failed htlc is 0)
```
NOTE: Alice dies after sending a revocation but before signing a
commitment. This is possible because there is a select block in the link
that can potentially exit after sending over the revocation but before
signing the next commitment state for the counterparty.
The first channels of a batch shouldn't publish the batch TX
to avoid problems if some of the funding flows can't be completed.
Only the last channel of a batch should publish. We set the channel flag
accordingly depending on the flag in the assembler.
This is useful when we wish to have a channel frozen for a specific
amount of blocks after its confirmation. This could also be done with an
absolute thaw height, but it does not suit cases where a strict block
delta needs to be enforced, as it's not possible to know for certain
when a channel will be included in the chain. To work around this, we
add a relative interpretation of the field, where if its value is below
500,000, then it's interpreted as a relative height. This approach
allows us to prevent further database modifications to account for a
relative thaw height.
This commit changes the verification of our code against the spec test
vectors to use a more black box approach. It exercises the channel state
machine via its external interface as much as possible, making this test
more robust. A consequence of this is that the test now runs from the
'root' data from which the test vectors are also derived, meaning that
more code is covered too.
Running from the root data is also a preparation for _producing_ test
vectors for the new anchor commitment format. This will be a matter of
changing the channel type and recording the produced commitment and htlc
txes.
Previously the success transaction was skipped during verification. With
this commit, the proper preimage insertion is carried out, allowing the
success tx to be checked too.
Introduces a new chancloser package which exposes a ChanCloser
struct that handles the cooperative channel closure negotiation
and is meant to replace chancloser.go in the lnd package. Updates
all references to chancloser.go to instead use chancloser package.
The current implementation of LeaseOutput already checked whether the
output had already been leased by the persisted implementation, but not
the in-memory one used by lnd internally. Without this check, we could
potentially end up with a double spend error if lnd acquired the UTXO
internally before the LeaseOutput call.
