When routing a keysend payment, the user may want to signal to the
router whether to find multi-path routes in the
`PaymentParameters::for_keysend` helper, without going through manual
construction. Since some implementations do not support MPP keysend, we
have the user make the choice here rather than making it the default.
Some implementations will reject keysend payments with payment secrets,
so this commit also adds docs to `RecipientOnionFields` to communicate
this to the user.
The `payment_hash` field in `PaymentPathSuccessful` is always
`Some` as long as the pening payment tracker has a `payment_hash`,
which is true for all `Pending` payments as well as all `Fulfilled`
payments starting with the commit which added
`PaymentPathSuccessful` -
3b5c370b404e2f5a8f3c35093b97406f149a9340c177c05252574083d68df0da.
This will allow us to block `ChannelMonitorUpdate`s on `Event`
processing in the next commit.
Note that this gets dangerously close to breaking forwards
compatibility - if we have an `Event` with an
`EventCompletionAction` tied to it, we persist a new, even, TLV in
the `ChannelManager`. Hopefully this should be uncommon, as it
implies an `Event` was delayed until after a full round-trip to a
peer.
This finally completes the piping of the `payment_metadata` from
from the BOLT11 invoice on the sending side all the way through the
onion sending + receiving ends to the user on the receive events.
When we receive an HTLC, we want to pass the `payment_metadata`
through to the `PaymentClaimable` event. This does most of the
internal refactoring required to do so - storing a
`RecipientOnionFields` in the inbound HTLC tracking structs,
including the `payment_metadata`.
In the future this struct will allow us to do MPP keysend receipts
(as it now stores an Optional `payment_secret` for all inbound
payments) as well as custom TLV receipts (as the struct is
extensible to store additional fields and the internal API supports
filtering for fields which are consistent across HTLCs).
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 passes the new `RecipientOnionFields` through the internal
sending APIs, ensuring we have access to the full struct when we
go to construct the sending onion so that we can include any new
fields added there.
While most lightning nodes don't (currently) support providing a
payment secret or payment metadata for spontaneous payments,
there's no specific technical reason why we shouldn't support
sending those fields to a recipient.
Further, when we eventually move to allowing custom TLV entries in
the recipient's onion TLV stream, we'll want to support it for
spontaneous payments as well.
Here we simply add the new `RecipientOnionFields` struct as an
argument to the spontaneous payment send methods. We don't yet
plumb it through the payment sending logic, which will come when we
plumb the new struct through the sending logic to replace the
existing payment secret arguments.
This moves the public payment sending API from passing an explicit
`PaymentSecret` to a new `RecipientOnionFields` struct (which
currently only contains the `PaymentSecret`). This gives us
substantial additional flexibility as we look at add both
`PaymentMetadata`, a new (well, year-or-two-old) BOLT11 invoice
extension to provide additional data sent to the recipient.
In the future, we should also add the ability to add custom TLV
entries in the `RecipientOnionFields` struct.
While retrying a failed path of an MPP, a node may want to overshoot
the `total_msat` in order to use a path with an `htlc_minimum_msat`
greater than the remaining value being sent. This commit no longer
fails MPPs that overshoot the `total_msat`, however it does fail
HTLCs with the same payment hash that are received *after* a
payment has become claimable.
This is largely motivated by some follow-up work for anchors that will
introduce an event handler for `BumpTransaction` events, which we can
now include in this new top-level `events` module.
`Route::get_route_with_id` exists to provide users payment-specific
data when fetching a route, however we were failing to call it when
we have such info, opting for the simple `get_route` instead. This
defeats the purpose of the additional-metadata method, which we
swap to using here.
fbc08477e8 purported to "move" the
`final_cltv_expiry_delta` field to `PaymentParamters` from
`RouteParameters`. However, for naive backwards-compatibility
reasons it left the existing on in place and only added a new,
redundant field in `PaymentParameters`.
It turns out there's really no reason for this - if we take a more
critical eye towards backwards compatibility we can figure out the
correct value in every `PaymentParameters` while deserializing.
We do this here - making `PaymentParameters` a `ReadableArgs`
taking a "default" `cltv_expiry_delta` when it goes to read. This
allows existing `RouteParameters` objects to pass the read
`final_cltv_expiry_delta` field in to be used if the new field
wasn't present.
This field was previous useful in manual retries for users to know when all
paths of a payment have failed and it is safe to retry. Now that we support
automatic retries in ChannelManager and no longer support manual retries, the
field is no longer useful.
For backwards compat, we now always write false for this field. If we didn't do
this, previous versions would default this field's value to true, which can be
problematic because some clients have relied on the field to indicate when a
full payment retry is safe.
Forcing users to pass a genesis block hash has ended up being
error-prone largely due to byte-swapping questions for bindings
users. Further, our API is currently inconsistent - in
`ChannelManager` we take a `Bitcoin::Network` but in `NetworkGraph`
we take the genesis block hash.
Luckily `NetworkGraph` is the only remaining place where we require
users pass the genesis block hash, so swapping it for a `Network`
is a simple change.
Prior to this, we returned PaymentSendFailure from auto retry send payment
methods. This implied that we might return a PartialFailure from them, which
has never been the case. So it makes sense to rework the errors to be a better
fit for the methods.
We're taking error handling in a totally different direction now to make it
more asynchronous, see send_payment_internal for more information.
