Once ChannelManager supports payment retries, it will make more sense for its
current send_payment method to be named send_payment_with_route because
retrying should be the default. Here we get a head start on this by making the
rename in outbound_payment, but not changing the public interface yet.
This allows us to move a lot of outbound payment logic out of ChannelManager
and into the new outbound_payment module, and helps avoid growing
ChannelManager when we add retry logic to it in upcoming work.
We want to move all outbound payment-related things to this new module, to help
break up ChannelManager so future payment retries work doesn't increase the
size of ChannelManager.
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.
If, after forwarding an intercepted payment to our counterparty, we
restart with a ChannelMonitor update having been persisted, but the
corresponding ChannelManager update not having been persisted,
we'll still have the intercepted HTLC in the
`pending_intercepted_htlcs` map on start (and potentially a pending
`HTLCIntercepted` event). This will cause us to allow the user to
handle the forwarded HTLC twice, potentially double-forwarding it.
This builds on 0bb87ddad7, which
provided a preemptive fix for the general relay case (though it was
not an actual issue at the time). We simply check for the HTLCs
having been forwarded on startup and remove them from the map.
Fixes#1858
If a user calls `abandon_payment`, then restarts without freshly
persisting the `ChannelManager`, the payment will still be pending
on restart. This was unclear from the docs (and the docs seemed to
imply otherwise). Because this doesn't materially impact the
usability of `abandon_payment` (users shouldn't be called
`retry_payment` on an abandoned one anyway), we simply document it.
Fixes#1804.
Define an interface for BOLT 12 `invoice_request` messages. The
underlying format consists of the original bytes and the parsed
contents.
The bytes are later needed when constructing an `invoice` message. This
is because it must mirror all the `offer` and `invoice_request` TLV
records, including unknown ones, which aren't represented in the
contents.
The contents will be used in `invoice` messages to avoid duplication.
Some fields while required in a typical user-pays-merchant flow may not
be necessary in the merchant-pays-user flow (e.g., refund, ATM).
Currently `claim_funds` and `claim_funds_internal` call
`claim_funds_from_hop` and then surface and `Event` to the user
informing them of the forwarded/claimed payment based on it's
result. In both places we assume that a claim "completed" even if
a monitor update is being done async.
Instead, here we push that event generation through a
`MonitorUpdateCompletionAction` and a call to
`handle_monitor_update_completion_action`. This will allow us to
hold the event(s) until async monitor updates complete in the
future.
When `claim_funds` has to claim multiple HTLCs as a part of a
single MPP payment, it currently does so holding the
`channel_state` lock for the entire duration of the claim loop.
Here we swap that for taking the lock once for each HTLC. This
allows us to be more flexible with locks going forward, and
ultimately isn't a huge change - if our counterparty intends to
force-close a channel, us choosing to ignore it by holding the
`channel_state` lock for the duration of the claim isn't going to
result in a commitment update, it will just result in the preimage
already being in the `ChannelMonitor`.
Currently `claim_funds` does all HTLC claims in one `channel_state`
lock, ensuring that we always make claims from channels which are
open. It can thus avoid ever having to generate a
`ChannelMonitorUpdate` containing a preimage for a closed channel,
which we only do in `claim_funds_internal` (for forwarded payments).
In the next commit we'll change the locking of
`claim_funds_from_hop` so that `claim_funds` is no longer under a
single lock but takes a lock for each claim. This allows us to be
more flexible with locks going forward, and ultimately isn't a huge
change - if our counterparty intends to force-close a channel, us
choosing to ignore it by holding the `channel_state` lock for the
duration of the claim isn't going to result in a commitment update,
it will just result in the preimage already being in the
`ChannelMonitor`.
This adds a new enum, `MonitorUpdateCompletionAction` and a method
to execute the "actions". They are intended to be done once a
(potentially-async) `ChannelMonitorUpdate` persistence completes,
however this behavior will be implemented in a future PR. For now,
this adds the relevant infrastructure which will allow us to
prepare `claim_funds` for better monitor async handling.
In the next commits we'll move to generating `PaymentClaimed`
events while handling `ChannelMonitorUpdate`s rather than directly
in line. Thus, as a prerequisite, here we move to storing the info
required to generate the `PaymentClaimed` event in a separate map.
Note that while this does introduce a new map which is written as
an even value which users cannot opt out of, the map is only filled
in when users use the asynchronous `ChannelMonitor` updates and
after a future PR. As these are still considered beta, breaking
downgrades for such users is considered acceptable in the future PR
(which will likely be one LDK version later).
If we try to send any onion error with the `UPDATE` flag in
response to a phantom receipt, we should always swap it for
something generic that doesn't require a `channel_update` in it.
Here we use `temporary_node_failure`.
Test provided by Valentine Wallace <vwallace@protonmail.com>
When we receive a phantom HTLC with a bogus/modified CLTV, we
should fail back with `incorrect_cltv_expiry`, but that requires a
`channel_update`, which we cannot generate for a phantom HTLC which
has no corresponding channel. Thus, instead, we have to fall back
to `incorrect_cltv_expiry`.
Fixes#1879
When we're constructing an HTLCFailReason, we should check that we
set the data to at least the correct length for the given failure
code, which we do here.
The spec mandates that we copy the `sha256_hash_of_onion` field
from the `UpdateFailMalformedHTLC` message into the error message
we send back to the sender, however we simply ignored it. Here we
copy it into the message correctly.
This replaces `final_expiry_too_soon` with
`incorrect_or_unknown_payment` as was done in
https://github.com/lightning/bolts/pull/608. Note that the
rationale for this (that it may expose whether you are the final
recipient for the payment or not) does not currently apply to us -
we don't apply different final CLTV values to different payments.
However, we might in the future, and this will make us slightly
more consistent with other nodes.
Now that `HTLCFailReason` is opaque and in `onion_utils`, we should
encapsulate it so that `ChannelManager` can no longer directly
access its inner fields.
