This is because we want the ability to retry completely failed
payments.
Upcoming commits will remove these payments on timeout to prevent
DoS issues
Also test that this removal allows retrying single-path payments
When we are prepared to forward HTLCs, we generate a
PendingHTLCsForwardable event with a time in the future when the
user should tell us to forward. This provides some basic batching
of forward events, improving privacy slightly.
After we generate the event, we expect users to spawn a timer in
the background and let us know when it finishes. However, if the
user shuts down before the timer fires, the user will restart and
have no idea that HTLCs are waiting to be forwarded/received.
To fix this, instead of serializing PendingHTLCsForwardable events
to disk while they're pending (before the user starts the timer),
we simply regenerate them when a ChannelManager is deserialized
with HTLCs pending.
Fixes#1042
546 sat/vbyte is the current default dust limit on most
implementations, matching the network dust limit for P2SH outputs.
Implementations don't currently appear to send any larger dust
limits, and allowing a larger dust limit implies higher payment
failure risk, so we'd like to be as tight as we can here.
When we detect a channel `is_shutdown()` or call on it
`force_shutdown()`, we notify the user with a Event::ChannelClosed
informing about the id and closure reason.
MessageSendEvent::PaymentFailureNetworkUpdate served as a hack to pass
an HTLCFailChannelUpdate from ChannelManager to NetGraphMsgHandler via
PeerManager. Instead, remove the event entirely and move the contained
data (renamed NetworkUpdate) to Event::PaymentFailed to be processed by
an event handler.
Now that NetworkGraph uses interior mutability, the RwLock used around
it in NetGraphMsgHandler is no longer needed. This allows for shared
ownership without a lock.
Latest rustc nightly compiles are filled with warnings like the
following, which we fix here:
```
warning: trailing semicolon in macro used in expression position
--> lightning/src/util/macro_logger.rs:163:114
|
163 | $logger.log(&$crate::util::logger::Record::new($lvl, format_args!($($arg)+), module_path!(), file!(), line!()));
| ^
|
::: lightning/src/chain/chainmonitor.rs:165:9
|
165 | log_debug!(self.logger, "New best block {} at height {} provided via block_connected", header.block_hash(), height);
| -------------------------------------------------------------------------------------------------------------------- in this macro invocation
|
= note: `#[warn(semicolon_in_expressions_from_macros)]` on by default
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #79813 <https://github.com/rust-lang/rust/issues/79813>
= note: this warning originates in the macro `log_internal` (in Nightly builds, run with -Z macro-backtrace for more info)
```
Because ln::functional_tests if over 9000 LoC long, its useful to
move tests into new modules as we can. Here we move all
cooperative shutdown related tests into a new module entitled
`shutdown_tests`
This adds the new range-based closing_signed negotiation specified
in https://github.com/lightningnetwork/lightning-rfc/pull/847 as
well as cleans up the existing closing_signed negotiation to unify
the new codepaths and the old ones.
Note that because the new range-based closing_signed negotiation
allows the channel fundee to ultimately select the fee out of a
range specified by the funder, which we, of course, always select
the highest allowed amount from. Thus, we've added an extra round
of closing_signed in the common case as we will not simply accept
the first fee we see, always preferring to make the funder pay as
much as they're willing to.
When we added the support for external signing, many of the
signing functions were allowed to return an error, closing the
channel in such a case. `sign_closing_transaction` is one such
function which can now return an error, except instead of handling
it properly we'd simply never send a `closing_signed` message,
hanging the channel until users intervene and force-close it.
Piping the channel-closing error back through the various callsites
(several of which already have pending results by the time they
call `maybe_propose_first_closing_signed`) may be rather
complicated, so instead we simply attempt to propose the initial
`closing_signed` in `get_and_clear_pending_msg_events` like we do
for holding-cell freeing.
Further, since we now (possibly) generate a `ChannelMonitorUpdate`
on `shutdown`, we may need to wait for monitor updating to complete
before we can send a `closing_signed`, meaning we need to handle
the send asynchronously anyway.
This simplifies a few function interfaces and has no impact on
behavior, aside from a few message-ordering edge-cases, as seen in
the two small test changes required.
Previously we'd been expecting to implement anchor outputs before
shipping 0.1, thus reworking our channel fee update process
entirely and leaving it as a future task. However, due to the
difficulty of working with on-chain anchor pools, we are now likely
to ship 0.1 without requiring anchor outputs.
In either case, there isn't a lot of reason to require that users
call an explicit "prevailing feerates have changed" function now
that we have a timer method which is called regularly. Further, we
really should be the ones deciding on the channel feerate in terms
of the users' FeeEstimator, instead of requiring users implement a
second fee-providing interface by calling an update_fee method.
Finally, there is no reason for an update_fee method to be
channel-specific, as we should be updating all (outbound) channel
fees at once.
Thus, we move the update_fee handling to the background, calling it
on the regular 1-minute timer. We also update the regular 1-minute
timer to fire on startup as well as every minute to ensure we get
fee updates even on mobile clients that are rarely, if ever, open
for more than one minute.
When a shutdown script is omitted from open_channel or accept_channel,
it must be provided when sending shutdown. Generate the shutdown script
at channel closing time in this case rather at channel opening.
This requires producing a ChannelMonitorUpdate with the shutdown script
since it is no longer known at ChannelMonitor creation.
It is useful for accounting and informational reasons for users to
be informed when a payment has been successfully forwarded. Thus,
when an HTLC which represents a forwarded leg is claimed, we
generate a new `PaymentForwarded` event.
This requires some additional plumbing to return HTLC values from
`OnchainEvent`s. Further, when we have to go on-chain to claim the
inbound side of the payment, we do not inform the user of the fee
reward, as we cannot calculate it until we see what is confirmed
on-chain.
Substantial code structure rewrites by:
Valentine Wallace <vwallace@protonmail.com>
test_onchain_to_onchain_claim was connecting additional blocks in
order to reach HTLC timeout and broadcast an HTLC-Timeout
transaction, resulting in it not testing whether HTLC preimages are
learned instantly in response to HTLC-Success transactions.
As the variable name implies holder_selected_chan_reserve_msat is
intended to be in millisatoshis, but is instead calculated in
satoshis.
We fix that error here and update the relevant tests to more
accurately calculate the expected reserve value and test both
success and failure cases.
Bug discovered by chanmon_consistency fuzz target.
