We currently have two codepaths on most channel update functions -
most methods return a set of messages to send a peer iff the
`ChannelMonitorUpdate` succeeds, but if it does not we push the
messages back into the `Channel` and then pull them back out when
the `ChannelMonitorUpdate` completes and send them then. This adds
a substantial amount of complexity in very critical codepaths.
Instead, here we swap all our channel update codepaths to
immediately set the channel-update-required flag and only return a
`ChannelMonitorUpdate` to the `ChannelManager`. Internally in the
`Channel` we store a queue of `ChannelMonitorUpdate`s, which will
become critical in future work to surface pending
`ChannelMonitorUpdate`s to users at startup so they can complete.
This leaves some redundant work in `Channel` to be cleaned up
later. Specifically, we still generate the messages which we will
now ignore and regenerate later.
This commit updates the `ChannelMonitorUpdate` pipeline across all
the places we generate them.
`PaymentParams` is all about the parameters for a payment, i.e. the
parameters which are static across all the paths of a paymet.
`RouteParameters` is about the information specific to a given
`Route` (i.e. a set of paths, among multiple potential sets of
paths for a payment). The CLTV delta thus doesn't belong in
`RouterParameters` but instead in `PaymentParameters`.
Worse, because `RouteParameters` is built from the information in
the last hops of a `Route`, when we deliberately inflate the CLTV
delta in path-finding, retries of the payment will have the final
CLTV delta double-inflated as it inflates starting from the final
CLTV delta used in the last attempt.
By moving the CLTV delta to `PaymentParameters` we avoid this
issue, leaving only the sought amount in the `RouteParameters`.
`test_duplicate_payment_hash_one_failure_one_success` currently
fails if the "wrong" HTLC is picked to be claimed. Given the HTLCs
are identical, there's no way to figure out which we should claim.
The test instead relies on a magic value - the first one is the
right one....unless we change our CSPRNG implementation. When we
try to do so, the test randomly fails.
Here we change one HTLC to a lower amount so we can figure out
which transaction to broadcast to make the test robust against
CSPRNG changes.
Adds two new payment `Method`s for identifying payments with custom
`min_final_cltv_expiry_delta` as payments with LDK or user payment
hashes.
The `min_final_cltv_expiry_delta` value is packed into the first 2
bytes of the expiry timestamp in the payment secret metadata.
In the next commit(s) we'll start holding `ChannelMonitorUpdate`s
that are being persisted in `Channel`s until they're done
persisting. In order to do that, switch to applying the updates by
reference instead of value.
This is purely a refactor that does not change the InitFeatures
advertised by a ChannelManager. This allows users to configure which
features should be advertised based on the values of `UserConfig`. While
there aren't any existing features currently leveraging this behavior,
it will be used by the upcoming anchors_zero_fee_htlc_tx feature.
The UserConfig dependency on provided_init_features caused most
callsites of the main test methods responsible for opening channels to
be updated. This commit foregos that completely by no longer requiring
the InitFeatures of each side to be provided to these methods. The
methods already require a reference to each node's ChannelManager to
open the channel, so we use that same reference to obtain their
InitFeatures. A way to override such features was required for some
tests, so a new `override_init_features` config option now exists on
the test harness.
This change follows the rationale of commit 62236c7 and addresses the
last remaining redundant local commitment broadcast.
There's no need to broadcast our local commitment transaction if we've
already seen a confirmed one as it'll be immediately rejected as a
duplicate/conflict.
This will also help prevent dispatching spurious events for bumping
commitment and HTLC transactions through anchor outputs since the
dispatch for said events follows the same flow as our usual commitment
broadcast.
Since `ChannelMonitor`s will now re-derive signers rather than
persisting them, we can no longer use the OnlyReadsKeysInterface
concrete implementation.
`get_channel_signer` previously had two different responsibilites:
generating unique `channel_keys_id` and using said ID to derive channel
keys. We decide to split it into two methods `generate_channel_keys_id`
and `derive_channel_signer`, such that we can use the latter to fulfill
our goal of re-deriving signers instead of persisting them. There's no
point in storing data that can be easily re-derived.
Soon we're going to need to return an error when ChannelManager is unable to
find a route, so we'll need a way to distinguish between that and the user
supplying an invalid route.
In many complexity-reduced implementations of chain syncing using
esplora `transactions_confirmed` may be called redundantly for
transactions which were already confirmed. To ensure this is
idempotent we add two new `ConnectionStyle`s in our tests which
(a) call `transactions_confirmed` twice for each call, ensuring
simple idempotency is ensured and (b) call `transactions_confirmed`
once for each historical block every time we're connecting a new
block, ensuring we're fully idempotent even if every call is
repeated constantly.
In order to actually behave correctly this requires a simple
already-confirmed check in `ChannelMonitor`, which is included.
In the next commit we'll add some checks that redundant
transactions aren't confirmed in different blocks, which would
cause test_htlc_ignore_latest_remote_commitment to fail. Here we
fix it to avoid the issue.
