With fee rates rising dramatically in mid-April 2023, thresholds for
what is considered dust have risen, often exceeding our previous dust
exposure threshold of 5k sats. This causes all payments and HTLC
forwards between 5k sats and new dust thresholds to fail.
This commit changes our max dust exposure config knob from a fixed
upper limit to a `MaxDustHTLCExposure` enum with an additional variant
to allow setting our max dust exposure to a multiplier on the current
high priority feerate.
To remain backwards compatible we'll always write the fixed limit if
it's set, or its default value in its currently reserved TLV.
We also now write an odd TLV for the new enum, so that previous
versions can safely ignore it upon downgrading, while allowing us to
make use of the new type when it's written.
Now that all of the core functionality for anchor outputs has landed,
we're ready to remove the config flag that was temporarily hiding it
from our API.
`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.
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`.
To reduce interleaving in commits, we introduce a `context` variable
in methods to be moved in upcoming commits so there is minimal change
with the moves.
This is one of a series of commits to make sure methods are moved by
chunks so they are easily reviewable in diffs. Unfortunately they are
not purely move-only as fields to be updated for things to
compile, but these should be quite clear.
This commit also uses the `context` field where needed for compilation
and tests to pass due to the above change.
f s/tarcontext.get_/target_/
This is one of a series of commits to make sure methods are moved by
chunks so they are easily reviewable in diffs. Unfortunately they are
not purely move-only as fields need to be updated for things to
compile, but these should be quite clear.
This commit also uses the `context` field where needed for compilation
and tests to pass due to the above change.
This is one of a series of commits to make sure methods are moved by
chunks so they are easily reviewable in diffs. Unfortunately they are
not purely move-only as fields need to be updated for things to
compile, but these should be quite clear.
This commit also uses the `context` field where needed for compilation
and tests to pass due to the above change.
This is one of a series of commits to make sure methods are moved by
chunks so they are easily reviewable in diffs. Unfortunately they are
not purely move-only as fields need to be updated for things to
compile, but these should be quite clear.
This commit also uses the `context` field where needed for compilation
and tests to pass due to the above change.
This is one of a series of commits to make sure methods are moved by
chunks so they are easily reviewable in diffs. Unfortunately they are
not purely move-only as fields need to be updated for things to
compile, but these should be quite clear.
This commit also uses these methods through the `context` field where
needed for compilation and tests to pass due to the above change.
This is one of a series of commits to make sure methods are moved by
chunks so they are easily reviewable in diffs. Unfortunately they are
not purely move-only as fields need to be updated for things to
compile, but these should be quite clear.
This is a first step for simplifying the channel state and introducing
new unfunded channel types that hold similar state before being promoted
to funded channels.
Essentially, we want the outer `Channel` type (and upcoming channel types)
to wrap the context so we can apply typestate patterns to the that wrapper
while also deduplicating code for common state and other internal fields.
Now that the `get_available_balances` min/max bounds are exact, we
can stop doing all the explicit checks in `send_htlc` entirely,
instead comparing against the `get_available_balances` bounds and
failing if the amount is out of those bounds.
This breaks support for sending amounts below the dust limit if
there is some amount of dust exposure remaining before we hit our
cap, however we will no longer generate such routes anyway.
Now that the value available to send is expected to match the
success or failure of sending exactly, we should assert this in the
`chanmon_consistency` fuzzer.
In the next commit we'll actually rip the checks out of `send_htlc`
which will make this a somewhat less useful test, however fuzzing
on this specific commit can help to reveal bugs.
When calculating the amount available to send for the next HTLC, if
we over-count we may create routes which are not actually usable.
Historically this has been an issue, which we resolve over a few
commits.
Here we consider how much adding one additional (dust) HTLC would
impact our total dust exposure, setting the new next-HTLC-minimum
field to require HTLCs be non-dust if required or set our next-HTLC
maximum if we cannot send a dust HTLC but do have some additional
exposure remaining.
We also add some testing when sending to ensure that send failures
are accounted for in our balance calculations.
Fixes#2252.
In the coming commits, in order to ensure all routes we generate
are usable, we'll start calculating the next-HTLC minimum for our
channels and using it in the router. Here we set this up by adding
an always-0 field for it in `ChannelDetails` and use it when
routing.
When calculating the amount available to send for the next HTLC, if
we over-count we may create routes which are not actually usable.
Historically this has been an issue, which we resolve over a few
commits.
Here we consider whether one additional HTLC's commitment tx fees
would result in the counterparty's commitment tx fees being greater
than the reserve we've picked for them and, if so, limit our next
HTLC value to only include dust HTLCs.
We also add some testing when sending to ensure that send failures
are accounted for in our balance calculations.
This, and the previous few commits, fixes#1126.
If a `ChannelMonitorUpdate` was created and given to the user but
left uncompleted when the `ChannelManager` is persisted prior to a
restart, the user likely lost the `ChannelMonitorUpdate`(s). Thus,
we need to replay them for the user, which we do here using the
new `BackgroundEvent::MonitorUpdateRegeneratedOnStartup` variant.
In the coming commits we'll need the counterparty node_id when
handling a background monitor update as we may need to resume
normal channel operation as a result. Thus, we go ahead and pipe it
through from the shutdown end, as it makes the codepaths
consistent.
Sadly, the monitor-originated shutdown case doesn't allow for a
required counterparty node_id as some versions of LDK didn't have
it present in the ChannelMonitor.
