Splitting further parsing from transaction generation, we cache
transaction elements needed for local HTLC transaction inside
OnchainTxHandler. Duplicated data will be removed from ChannelMonitor
in future commits.
Implementing dynamic fee bumping implied to cache transaction material
including its witness, to generate a bumped version if needed.
ChannelMonitor is slowly rescoped to its parsing function with ongoing
patchset and data duplicata are removed. If signed local commitment tx
access is needed, it's done through OnchainTxHandler extended API
For test framework purpose, we use the test-only method
ChannelMonitor::unsafe_get_latest_local_commitment_txn to intentionally
generate unsafe local commitment to exerce revocation logic.
Local Commitment Transaction can't be bumped without anchor outputs
so their generation is one-time for now. We move them in
OnchainTxHandler for simplifying ChannelMonitor and to prepare
storage of keys material behind one external signer interface.
Some tests break due to change in transaction broadcast order but
number of transactions broadcast should stay the same.
To prevent any unsafe state discrepancy between offchain and onchain,
once local commitment transaction has been signed due to an event
(either block height for HTLC-timeout or channel force-closure), don't
allow any further update of local commitment transaction view
to avoid delivery of revocation secret to counterparty for the
aformentionned signed transaction.
As transaction generation and signature is headed to be moved
inside OnchainTxHandler, cache local_commitment_tx signed by remote.
If access to local commitment transaction is needed, we extend Onchain
TxHandler API to do so.
Rename ChannelMonitor::Storage to OnchainDetection,
holder of channel state (base_key+per_commitment_point)
to detect onchain transactions accordingly.
Going further between splitting detection and transaction
generation, we endow OnchainTxHandler with keys access.
That way, in latter commits, we may remove secret keys entirely
from ChannelMonitor.
Previously, we would generate SpendableOutputDescriptor::StaticOutput
in OnchainTxHandler even if our claiming transaction wouldn't confirm
onchain, misbehaving user wallet to think it receives more funds than
in reality.
Fix tests in consequence
Adjusted tx occurs when a previous aggregated claim tx has
seen one of its outpoint being partially claimed by a remote tx.
To pursue claiming of the remaining outpoint a adjusted claim tx
is generated with leftover of claimable outpoints.
Previously, in case of block-rescan where a partial claim occurs,
we would generate duplicated adjusted tx, wrongly inflating feerate
for next bumps. At rescan, if input has already been dropped from
outpoints map from a claiming request, don't regenerate again
a adjuste tx.
Instead of passing a Vec of Vecs drop them into one as we go in
ChannelMonitor, hopefully avoiding a bit of memory fragmentation
and improving readability.
Encapsulates tracking and bumping of in-flight transactions in
its own component. This component may be latter abstracted
to reuse tracking and RBF for new features (e.g dual-funding,
splicing)
Build all transactions generation in one place. Also as fees
and signatures are closely tied, what keys do you have determine
what bumping mode you can use.
