Currently, users have no means to upper-bound the total fees accruing
when finding a route. Here, we add a corresponding field to
`RouteParameters` which will be used to limit the candidate set during
path finding in the following commits.
We add a `ChannelManager::send_preflight_probes` method that can be used
to send pre-flight probes given some [`RouteParameters`]. Additionally,
we add convenience methods in for spontaneous probes and send pre-flight
probes for a given invoice.
As pre-flight probes might take up some of the available liquidity, we
here introduce that channels whose available liquidity is less than the
required amount times
`UserConfig::preflight_probing_liquidity_limit_multiplier` won't be used
to send pre-flight probes.
This commit is a more or less a carbon copy of the pre-flight
probing code recently added to LDK Node.
In 0ad1f4c943 we fixed a nasty bug
where a failure to persist a `ChannelManager` faster than a
`ChannelMonitor` could result in the loss of a `PaymentSent` event,
eventually resulting in a `PaymentFailed` instead!
As noted in that commit, there's still some risk, though its been
substantially reduced - if we receive an `update_fulfill_htlc`
message for an outbound payment, and persist the initial removal
`ChannelMonitorUpdate`, then respond with our own
`commitment_signed` + `revoke_and_ack`, followed by receiving our
peer's final `revoke_and_ack`, and then persist the
`ChannelMonitorUpdate` generated from that, all prior to completing
a `ChannelManager` persistence, we'll still forget the HTLC and
eventually trigger a `PaymentFailed` rather than the correct
`PaymentSent`.
Here we fully fix the issue by delaying the final
`ChannelMonitorUpdate` persistence until the `PaymentSent` event
has been processed and document the fact that a spurious
`PaymentFailed` event can still be generated for a sent payment.
The original fix in 0ad1f4c943 is
still incredibly useful here, allowing us to avoid blocking the
first `ChannelMonitorUpdate` until the event processing completes,
as this would cause us to add event-processing delay in our general
commitment update latency. Instead, we ultimately race the user
handling the `PaymentSent` event with how long it takes our
`revoke_and_ack` + `commitment_signed` to make it to our
counterparty and receive the response `revoke_and_ack`. This should
give the user plenty of time to handle the event before we need to
make progress.
Sadly, because we change our `ChannelMonitorUpdate` semantics, this
change requires a number of test changes, avoiding checking for a
post-RAA `ChannelMonitorUpdate` until after we process a
`PaymentSent` event. Note that this does not apply to payments we
learned the preimage for on-chain - ensuring `PaymentSent` events
from such resolutions will be addressed in a future PR. Thus, tests
which resolve payments on-chain switch to a direct call to the
`expect_payment_sent` function with the claim-expected flag unset.
Custom TLVs allow users to send extra application-specific data with
a payment. These have the additional flexibility compared to
`payment_metadata` that they don't have to reflect recipient generated
data provided in an invoice, in which `payment_metadata` could be
reused.
We ensure provided type numbers are unique, increasing, and within the
experimental range with the `RecipientOnionFields::with_custom_tlvs`
method.
This begins sender-side support for custom TLVs.
This was a regression resulting from f2453b7 since we now process events
in a loop until there aren't any left. Processing events is done in
batches and they are not removed until we're done processing each batch.
Since handling a `PendingHTLCsForwardable` event will call back into the
`ChannelManager`, we'll still see the original forwarding event not
removed. Phantom payments will need an additional forwarding event
before being claimed to make them look real by taking more time.
This ensures freshly initialized nodes can proceed to create unexpired
invoices without a call to `best_block_updated`, since an invoice's
expiration delta is applied to `highest_seen_timestamp`.
This adds the new `payment_metadata` to `RecipientOnionFields`,
passing the metadata from BOLT11 invoices through the send pipeline
and finally copying them info the onion when sending HTLCs.
This completes send-side support for the new payment metadata
feature.
This adds support for setting the new payment metadata field in
BOLT11 invoices, using a new type flag on the builder to enforce
transition correctness.
We allow users to set the payment metadata as either optional or
required, defaulting to optional so that invoice parsing does not
fail if the sender does not support payment metadata fields.
This adds support for reading the new `PaymentMetadata` BOLT11
invoice field, giving us access to the `Vec<u8>` storing arbitrary
bytes we have to send to the recipient.
