In this commit, we start to use the new AuxSigner to obtain+verify aux sigs for all second level HTLCs. This is similar to the existing SigPool, but we'll only attempt to do this if the AuxSigner is present (won't be for most channels).
In this commit, we start to thread thru the new aux tap leaf structures to all relevant areas. This includes: commitment outputs, resolution creation, breach handling, and also HTLC scripts.
Given the aux leaf store, and a struct that describes the current commitment, we can obtain the CommitAuxLeaves struct, then use that to derive the aux leaves for the commitment outputs and also HTLCs as well.
When restoring commitments and pay descs from disk, we'll store the aux leaves as custom TLV blobs on disk, then use the aux leaf store to map back to the concrete aux leaves when needed.
In this commit, we add a TLV blob to the PaymentDescriptor struct. We also now thread through this value from the UpdateAddHTLC message to the PaymentDescriptor mapping, and the other way around.
In this commit, we add a new AuxLeafStore which can be used to dynamically fetch the latest aux leaves for a given state. This is useful for custom channel types that will store some extra information in the form of a custom blob, then will use that information to derive the new leaf tapscript leaves that may be attached to reach state.
In this commit, we also add the custom TLV blob to the internal commitment struct that we use within the in-memory commitment linked list.
This'll be useful to ensure that we're tracking the current blob for our in memory commitment for when we need to write it to disk.
In this commit, we update all the taproot scripts to also accept an
optional aux leaf. This aux leaf can be used to add more redemption
paths for advanced channels, or just as an extra commitment space.
With this commit, the channel is now aware of if it's a musig2 channel, that also has a tapscript root. We'll need to always pass in the tapscript root each time we: make the funding output, sign a new state, and also verify a new state.
This commit adds an optional blinding point to payment descriptors and
persists them in our HTLC's extra data. A get/set pattern is used to
populate the ExtraData on our disk representation of the HTLC so that
callers do not need to worry about the underlying storage detail.
When determining the max fee rate of a channel we used to scale
the fee rate depending on our available local balance on this channel.
This lead to a special case that if a channel would be drained we
could especially decrease the fee rate even down to the fee floor.
Now we make sure that our max fee rate will not be lower than the
old fee rate to make sure in case our channel is locally drained
we do not continue to decrease fees too low.
In this commit, we update new Taproot related TLVs (nonces, partial sig,
sig with nonce, etc). Along the way we were able to get rid of some
boiler plate, but most importantly, we're able to better protect against
API misuse (using a nonce that isn't initialized, etc) with the new
options API. In some areas this introduces a bit of extra boiler plate,
and where applicable I used some new helper functions to help cut down
on the noise.
Note to reviewers: this is done as a single commit, as changing the API
breaks all callers, so if we want things to compile it needs to be in a
wumbo commit.
ShutdownInfo contains any info about a previous Shutdown message that we
have sent. This commit adds this type along with read and write methods
for it in the channel db. The existence of the ShutdownInfo on disk
represents the fact that we have previously sent the Shutdown message
and hence that we should resend it on re-establish.
Over the last few commits we have systematically eliminated all but
two states. This allows us to replace it with a boolean to encode
the two remaining states. We would like to be able to eliminate this
field entirely, but doing so requires being able to prove that the
concurrent request block is necessary. This is more difficult and
will be left to future commits.
lnwallet: remove unused channelPendingPayment channelState
Since this state is never set nor read, we remove it completely.
lnwallet: remove redundant channelDispute channelState
In this case, even though we do set this value, it is never read.
Further, the times we read the field at all from LightningChannel
we want the situation of force-closure to block any other
concurrent closure attempts, so we change the sites where we set
channelDispute to channelClosed.
lnwallet: remove redundant channelClosing channelStatus
This value is never used to impact control flow so we need not set
it. We also need not have it.
We take into account a fee buffer of twice the current fee rate
of the commitment transaction plus an additional htlc output
when we are the opener of the channel hence pay when publishing the
commitment transaction. This buffer is not consensus critical
because we only consider it when we are in control of adding a
new htlc to the state. The goal is to prevent situations
where we push our local balance below our channel reserve due to
parallel adding of htlcs to the state. Its not a panacea for these
situations but until we have __option_simplified_update__ deployed
widely on the network its a good precaution to protect against
fee spikes and parallel adding of htlcs to the update log.
Moreover the way the available balance for a channel changed.
We now need to account for a fee buffer when we are the channel
opener. Therefore all the tests had to be adopted.
Prior to this commit, taproot channels had a bug:
- If a disconnect happened before peer.AddNewChannel was called,
then the subsequent reconnect would call peer.AddNewChannel and
attempt the ChannelReestablish dance.
- peer.AddNewChannel would call NewLightningChannel with
populated nonce ChannelOpts. This in turn would call
InitRemoteMusigNonces which would create a new musig pair session
and set the channel's pendingVerificationNonce to nil.
- During the reestablish dance, ProcessChanSyncMsg would be called.
This would also call InitRemoteMusigNonces, except it would fail
since pendingVerificationNonce was set to nil in the previous
invocation.
To fix this, we add a new functional option to signal to the init logic
that it doesn't need to call InitRemoteMusigNonces in in
ProcessChanSyncMsg.
In this commit, update the start up logic to gracefully handle a
seemingly rare case. In this case, a peer detects local data loss with a
set of active HTLCs. These HTLCs then eventually expire (they may or may
not actually "exist"), causing a force close decision. Before this PR,
this attempt would fail with a fatal error that can impede start up.
To better handle such a scenario, we'll now catch the error when we fail
to force close due to entering the DLP and instead terminate the state
machine at the broadcast state. When a commitment transaction eventually
confirms, we'll play it as normal.
Fixes https://github.com/lightningnetwork/lnd/issues/7984
* lnwallet: fix log output msg
The log message is off by one.
* htlcswitch: fail channel when revoking it fails.
When the revocation of a channel state fails after receiving a new
CommitmentSigned msg we have to fail the channel otherwise we
continue with an unclean state.
* docs: update release-docs
* htlcswitch: tear down connection if revocation processing fails
If we couldn't revoke due to a DB error, then we want to also tear down
the connection, as we don't want the other party to continue to send
updates. That may lead to de-sync'd state an eventual force close.
Otherwise, the database might be able to recover come the next
reconnection attempt.
* kvdb: use sql.LevelSerializable for all backends
In this commit, we modify the default isolation level to be
`sql.LevelSerializable. This is the strictness isolation type for
postgres. For sqlite, there's only ever a single writer, so this doesn't
apply directly.
* kvdb/sqlbase: add randomized exponential backoff for serialization failures
In this commit, we add randomized exponential backoff for serialization
failures. For postgres, we''ll his this any time a transaction set fails
to be linearized. For sqlite, we'll his this if we have many writers
trying to grab the write lock at time same time, manifesting as a
`SQLITE_BUSY` error code.
As is, we'll retry up to 10 times, waiting a minimum of 50 miliseconds
between each attempt, up to 5 seconds without any delay at all. For
sqlite, this is also bounded by the busy timeout set, which applies on
top of this retry logic (block for busy timeout seconds, then apply this
back off logic).
* docs/release-notes: add entry for sqlite/postgres tx retry
---------
Co-authored-by: ziggie <ziggie1984@protonmail.com>
We use a helper function to ensure that anytime we're about to make a
normal sighash, we consult the channel type to check if we should use
the default value or sighash all explicitly.
