Similar to what we did for the local state handling, we extract handling
all known remote states we can act on (breach, current, pending state)
into its own method.
Since we want to handle the case where we lost state (both in case of
local and remote close) last, we don't rely on the remote state number
to check which commit we are looking at, but match on TXIDs directly.
Similarly as with kvdb.View this commits adds a reset closure to the
kvdb.Update call in order to be able to reset external state if the
underlying db backend needs to retry the transaction.
This commit adds a reset() closure to the kvdb.View function which will
be called before each retry (including the first) of the view
transaction. The reset() closure can be used to reset external state
(eg slices or maps) where the view closure puts intermediate results.
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.
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.
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 removes ChanStatusDefault from the list of
orderedChanStatusFlags since it is not flag. As with the prior commit,
the logic around these flags assumes everything in the list is a flag,
but ChanStatusDefault is not.
It turns out we properly special case that if the channel is in
ChanStatusDefault that we only return ChanStatusDefault. However, if any
of the bits are set we would always report ChanStatusDefault since
status&0 == 0. This fixed simply by removing ChanStatusDefault from the
list since we only need the list to express non-default status flags.
This commit resovles a lingering issue w/in the codebase wrt how the
ChannelStatus flags are defined. Currently ChannelStatus is improperly
used to define a bit field and the individual flags themselves. As a
result, HasChanStatus accepts queries on particular status (combinations
of flags) and individual flags themselves.
This is an issue because the way HasChanStatus computes whether the
channel has a particular status assumes the provided inputs are all
flags (or at least combinations of flags).
However, ChanStatusDefault is simply the absence of any other flag.
Hence, HasChanStatus will always return true when querying for
ChanStatusDefault because status&0 == 0 is always true.
Longer term we should should consider splitting these definitions into
flags and particular states, and change the way construct or operate on
them, but for now I've just special-cased this one value. Fortunately,
we don't query HasChannelStatus w/ ChanStatusDefault anywhere in the
codebase so we dodge a bullet here, but it'd be nice to have some
greater assurances moving forward.
This commit changes the fallback in NextLocalHtlcIndex to
RemoteCommitment since the LocalHtlcIndex field lags behind
on the LocalCommitment. Without this bug fix, open circuits
would get prematurely trimmed, resulting in more erroneous
logs. A test case is included to check that the fix works.
In this commit, we add a new channel type bit: a frozen channel. A
frozen channel is one that can only be cooperatively closed by the
responder, but not the initiator. This channel type is useful for
certain classes of channel factory like protocols. We then add a new key
on the channel bucket level to store the height after which this
restriction no longer applies.
Add a balance at height lookup function which can be used to
obtain local/remote balance at a given height. The current in memory
commits and revocation log are used to source this information.
The explicit `bbolt` dep is gone, as we depend on `kvdb`, which is
actually `walletdb`, which has its own module that defines the proper
`bbolt` version.
In this commit, we migrate all the code in `channeldb` to only reference
the new `kvdb` package rather than `bbolt` directly.
In many instances, we need to add two version to fetch a bucket as both
read and write when needed. As an example, we add a new
`fetchChanBucketRw` function. This function is identical to
`fetchChanBucket`, but it will be used to fetch the main channel bucket
for all _write_ transactions. We need a new method as you can pass a
write transaction where a read is accepted, but not the other way around
due to the stronger typing of the new `kvdb` package.
Add an optional channel status CloseChannel which will be stored on the
hitsorical channel which is persisted at channel close. This status is
used to set the close initiator for channels that do not complete the
funding flow or we abandon. In follow up commits, this status will be
used to record force and breach closes. The value is written to the
historical channel bucket for diplay over rpc.
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 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 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.
In this commit, we add a new bit to the existing ChannelType bitfield.
If this bit is set, then it signals that we have the funding transaction
stored on disk. A future change will enable lnd to have the funding
transaction be constructed externally, allowing for things like funding
from a hardware wallet, or a channel created as a sub-branch within an
existing channel factory.
Refresh channel memory state whenever the short channel id is refreshed.
This is to make the in-memory channel consistent with the disk data.
Fixes#3765.
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).
In this commit, we update the channel state machine to be aware of
tweakless commits. In several areas, we'll now check the channel's type
to see if it's `SingleFunderTweakless`. If so, then we'll opt to use the
remote party's non-delay based point directly in the script, skipping
any additional cryptographic operations. Along the way we move the
`validateCommitmentSanity` method to be defined _before_ it's used as is
cutomary within the codebase.
Notably, within the `NewUnilateralCloseSummary` method, we'll now _blank
out_ the `SingleTweak` value if the commitment is tweakless. This
indicates to callers the witness type they should map to, as the value
isn't needed at all any longer when sweeping a non-delay output.
We also update the signing+verification tests to also test that we're
able to properly generate a valid witness for the new tweakless
commitment format.
In this commit, we define a new channel type: SingleFunderTweakless.
We'll use this channel type to denote channels with commitments that
don't tweak the remote party's key in their non-delay output.
