`Channel::get_latest_complete_monitor_update_id` no longer refers
to complete updates, but rather ones which were passed to the
`ChannelManager` and which the `CHannel` no longer knows about.
Thus, we rename it `get_latest_unblocked_monitor_update_id`.
Because `ChannelMonitorUpdate`s can be generated for a
channel which is already closed, and must still be tracked
through their completion, storing them in a `Channel`
doesn't make sense - we'd have to have a redundant place to
put them post-closure and handle both storage locations
equivalently.
Instead, here, we move to storing in-flight
`ChannelMonitorUpdate`s to the `ChannelManager`, leaving
blocked `ChannelMonitorUpdate`s in the `Channel` as they
were.
This change modifies six structs that were keeping
track of anchors features with an `opt_anchors` field,
as well as another field keeping track of nonzero-fee-
anchor-support.
Specifically, introduce a new constructor for an anchors-
supporting feature set, as well as methods that will
maintain forwards-compatible deserialization in older
versions.
By giving up on a tiny bit of parallelism and tweaking the return
types, we can make the `handle_new_monitor_update` macro a bit
clearer - now the only cases where its called after a monitor was
updated was when the monitor was initially committed.
Most of the calls to the `handle_new_monitor_update` macro had the
exact same pattern - calling `update_monitor` followed by the
macro. Given that common pattern will grow to first pushing the
new monitor onto an in-flight set and then calling `update_monitor`
unifying the pattern into a single macro now avoids more code churn
in the coming commits.
In the coming commits we'll move to storing in-flight
`ChannelMonitorUpdate`s in the `ChannelManager` rather in the
`Channel` (which will then only retain `ChannelMonitorUpdate`s
which have not yet been released/are blocked.
This will simplify handling of pending `ChannelMonitorUpdate` after
a channel has closed by not having to move them into the
`ChannelManager`.
Downstream crates building fur fuzzing will usually set
`--cfg=fuzzing` as a side-effect of the Rust fuzzing tooling. Thus,
we should ensure we build without failure in such cases.
We do this here by simply relying on the `_test_utils` feature,
rather than conditionally-compiling in modules based on the
`fuzzing` flag.
Make sure the penultimate hop took the amount of fee that they claimed to take.
Without checking this TLV, we're heavily relying on the receiving wallet code
to correctly implement logic to calculate that that the fee is as expected.
Useful for penultimate hops in routes to take an extra fee, if for example they
opened a JIT channel to the payee and want them to help bear the channel open
cost.
We need the channel lock for constructing a pending HTLC's status because we
need to know if the channel accepts underpaying HTLCs in upcoming commits.
This allows users to bump their commitments and HTLC transactions
without having to worry about all the little details to do so. Instead,
we'll just require that they implement the `CoinSelectionSource` trait
over their wallet/UTXO source, granting the event handler permission to
spend confirmed UTXOs for the transactions it'll produce.
While the event handler should in most cases produce valid transactions,
assuming the provided confirmed UTXOs are valid, it may not produce
relayable transactions due to not satisfying certain Replace-By-Fee
(RBF) mempool policy requirements. Some of these require that the
replacement transactions have a higher feerate and absolute fee than the
conflicting transactions it aims to replace. To make sure we adhere to
these requirements, we'd have to persist some state for all transactions
the event handler has produced, greatly increasing its complexity. While
we may consider implementing so in the future, we choose to go with a
simple initial version that relies on the OnchainTxHandler's bumping
frequency. For each new bumping attempt, the OnchainTxHandler proposes a
25% feerate increase to ensure transactions can propagate under
constrained mempool circumstances.
This commit also adds two new maps to `PeerState` for keeping track
of `OutboundV1Channel`s and `InboundV1Channel`s so that further
commits are a bit easier to review.
