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Expose HTLC transaction locktime in BumpTransactionEvent::HTLCResolution
[rust-lightning] / lightning / src / events / mod.rs
1 // This file is Copyright its original authors, visible in version control
2 // history.
3 //
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
8 // licenses.
9
10 //! Events are returned from various bits in the library which indicate some action must be taken
11 //! by the client.
12 //!
13 //! Because we don't have a built-in runtime, it's up to the client to call events at a time in the
14 //! future, as well as generate and broadcast funding transactions handle payment preimages and a
15 //! few other things.
16
17 #[cfg(anchors)]
18 pub mod bump_transaction;
19
20 #[cfg(anchors)]
21 pub use bump_transaction::BumpTransactionEvent;
22
23 use crate::chain::keysinterface::SpendableOutputDescriptor;
24 use crate::ln::channelmanager::{InterceptId, PaymentId};
25 use crate::ln::channel::FUNDING_CONF_DEADLINE_BLOCKS;
26 use crate::ln::features::ChannelTypeFeatures;
27 use crate::ln::msgs;
28 use crate::ln::{PaymentPreimage, PaymentHash, PaymentSecret};
29 use crate::routing::gossip::NetworkUpdate;
30 use crate::util::errors::APIError;
31 use crate::util::ser::{BigSize, FixedLengthReader, Writeable, Writer, MaybeReadable, Readable, RequiredWrapper, UpgradableRequired, WithoutLength};
32 use crate::util::string::UntrustedString;
33 use crate::routing::router::{RouteHop, RouteParameters};
34
35 use bitcoin::{PackedLockTime, Transaction};
36 use bitcoin::blockdata::script::Script;
37 use bitcoin::hashes::Hash;
38 use bitcoin::hashes::sha256::Hash as Sha256;
39 use bitcoin::secp256k1::PublicKey;
40 use crate::io;
41 use crate::prelude::*;
42 use core::time::Duration;
43 use core::ops::Deref;
44 use crate::sync::Arc;
45
46 /// Some information provided on receipt of payment depends on whether the payment received is a
47 /// spontaneous payment or a "conventional" lightning payment that's paying an invoice.
48 #[derive(Clone, Debug, PartialEq, Eq)]
49 pub enum PaymentPurpose {
50         /// Information for receiving a payment that we generated an invoice for.
51         InvoicePayment {
52                 /// The preimage to the payment_hash, if the payment hash (and secret) were fetched via
53                 /// [`ChannelManager::create_inbound_payment`]. If provided, this can be handed directly to
54                 /// [`ChannelManager::claim_funds`].
55                 ///
56                 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
57                 /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
58                 payment_preimage: Option<PaymentPreimage>,
59                 /// The "payment secret". This authenticates the sender to the recipient, preventing a
60                 /// number of deanonymization attacks during the routing process.
61                 /// It is provided here for your reference, however its accuracy is enforced directly by
62                 /// [`ChannelManager`] using the values you previously provided to
63                 /// [`ChannelManager::create_inbound_payment`] or
64                 /// [`ChannelManager::create_inbound_payment_for_hash`].
65                 ///
66                 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
67                 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
68                 /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
69                 payment_secret: PaymentSecret,
70         },
71         /// Because this is a spontaneous payment, the payer generated their own preimage rather than us
72         /// (the payee) providing a preimage.
73         SpontaneousPayment(PaymentPreimage),
74 }
75
76 impl_writeable_tlv_based_enum!(PaymentPurpose,
77         (0, InvoicePayment) => {
78                 (0, payment_preimage, option),
79                 (2, payment_secret, required),
80         };
81         (2, SpontaneousPayment)
82 );
83
84 /// When the payment path failure took place and extra details about it. [`PathFailure::OnPath`] may
85 /// contain a [`NetworkUpdate`] that needs to be applied to the [`NetworkGraph`].
86 ///
87 /// [`NetworkUpdate`]: crate::routing::gossip::NetworkUpdate
88 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
89 #[derive(Clone, Debug, Eq, PartialEq)]
90 pub enum PathFailure {
91         /// We failed to initially send the payment and no HTLC was committed to. Contains the relevant
92         /// error.
93         InitialSend {
94                 /// The error surfaced from initial send.
95                 err: APIError,
96         },
97         /// A hop on the path failed to forward our payment.
98         OnPath {
99                 /// If present, this [`NetworkUpdate`] should be applied to the [`NetworkGraph`] so that routing
100                 /// decisions can take into account the update.
101                 ///
102                 /// [`NetworkUpdate`]: crate::routing::gossip::NetworkUpdate
103                 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
104                 network_update: Option<NetworkUpdate>,
105         },
106 }
107
108 impl_writeable_tlv_based_enum_upgradable!(PathFailure,
109         (0, OnPath) => {
110                 (0, network_update, upgradable_option),
111         },
112         (2, InitialSend) => {
113                 (0, err, upgradable_required),
114         },
115 );
116
117 #[derive(Clone, Debug, PartialEq, Eq)]
118 /// The reason the channel was closed. See individual variants more details.
119 pub enum ClosureReason {
120         /// Closure generated from receiving a peer error message.
121         ///
122         /// Our counterparty may have broadcasted their latest commitment state, and we have
123         /// as well.
124         CounterpartyForceClosed {
125                 /// The error which the peer sent us.
126                 ///
127                 /// Be careful about printing the peer_msg, a well-crafted message could exploit
128                 /// a security vulnerability in the terminal emulator or the logging subsystem.
129                 /// To be safe, use `Display` on `UntrustedString`
130                 /// 
131                 /// [`UntrustedString`]: crate::util::string::UntrustedString
132                 peer_msg: UntrustedString,
133         },
134         /// Closure generated from [`ChannelManager::force_close_channel`], called by the user.
135         ///
136         /// [`ChannelManager::force_close_channel`]: crate::ln::channelmanager::ChannelManager::force_close_channel.
137         HolderForceClosed,
138         /// The channel was closed after negotiating a cooperative close and we've now broadcasted
139         /// the cooperative close transaction. Note the shutdown may have been initiated by us.
140         //TODO: split between CounterpartyInitiated/LocallyInitiated
141         CooperativeClosure,
142         /// A commitment transaction was confirmed on chain, closing the channel. Most likely this
143         /// commitment transaction came from our counterparty, but it may also have come from
144         /// a copy of our own `ChannelMonitor`.
145         CommitmentTxConfirmed,
146         /// The funding transaction failed to confirm in a timely manner on an inbound channel.
147         FundingTimedOut,
148         /// Closure generated from processing an event, likely a HTLC forward/relay/reception.
149         ProcessingError {
150                 /// A developer-readable error message which we generated.
151                 err: String,
152         },
153         /// The peer disconnected prior to funding completing. In this case the spec mandates that we
154         /// forget the channel entirely - we can attempt again if the peer reconnects.
155         ///
156         /// This includes cases where we restarted prior to funding completion, including prior to the
157         /// initial [`ChannelMonitor`] persistence completing.
158         ///
159         /// In LDK versions prior to 0.0.107 this could also occur if we were unable to connect to the
160         /// peer because of mutual incompatibility between us and our channel counterparty.
161         ///
162         /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
163         DisconnectedPeer,
164         /// Closure generated from `ChannelManager::read` if the [`ChannelMonitor`] is newer than
165         /// the [`ChannelManager`] deserialized.
166         ///
167         /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
168         /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
169         OutdatedChannelManager
170 }
171
172 impl core::fmt::Display for ClosureReason {
173         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
174                 f.write_str("Channel closed because ")?;
175                 match self {
176                         ClosureReason::CounterpartyForceClosed { peer_msg } => {
177                                 f.write_fmt(format_args!("counterparty force-closed with message: {}", peer_msg))
178                         },
179                         ClosureReason::HolderForceClosed => f.write_str("user manually force-closed the channel"),
180                         ClosureReason::CooperativeClosure => f.write_str("the channel was cooperatively closed"),
181                         ClosureReason::CommitmentTxConfirmed => f.write_str("commitment or closing transaction was confirmed on chain."),
182                         ClosureReason::FundingTimedOut => write!(f, "funding transaction failed to confirm within {} blocks", FUNDING_CONF_DEADLINE_BLOCKS),
183                         ClosureReason::ProcessingError { err } => {
184                                 f.write_str("of an exception: ")?;
185                                 f.write_str(&err)
186                         },
187                         ClosureReason::DisconnectedPeer => f.write_str("the peer disconnected prior to the channel being funded"),
188                         ClosureReason::OutdatedChannelManager => f.write_str("the ChannelManager read from disk was stale compared to ChannelMonitor(s)"),
189                 }
190         }
191 }
192
193 impl_writeable_tlv_based_enum_upgradable!(ClosureReason,
194         (0, CounterpartyForceClosed) => { (1, peer_msg, required) },
195         (1, FundingTimedOut) => {},
196         (2, HolderForceClosed) => {},
197         (6, CommitmentTxConfirmed) => {},
198         (4, CooperativeClosure) => {},
199         (8, ProcessingError) => { (1, err, required) },
200         (10, DisconnectedPeer) => {},
201         (12, OutdatedChannelManager) => {},
202 );
203
204 /// Intended destination of a failed HTLC as indicated in [`Event::HTLCHandlingFailed`].
205 #[derive(Clone, Debug, PartialEq, Eq)]
206 pub enum HTLCDestination {
207         /// We tried forwarding to a channel but failed to do so. An example of such an instance is when
208         /// there is insufficient capacity in our outbound channel.
209         NextHopChannel {
210                 /// The `node_id` of the next node. For backwards compatibility, this field is
211                 /// marked as optional, versions prior to 0.0.110 may not always be able to provide
212                 /// counterparty node information.
213                 node_id: Option<PublicKey>,
214                 /// The outgoing `channel_id` between us and the next node.
215                 channel_id: [u8; 32],
216         },
217         /// Scenario where we are unsure of the next node to forward the HTLC to.
218         UnknownNextHop {
219                 /// Short channel id we are requesting to forward an HTLC to.
220                 requested_forward_scid: u64,
221         },
222         /// We couldn't forward to the outgoing scid. An example would be attempting to send a duplicate
223         /// intercept HTLC.
224         InvalidForward {
225                 /// Short channel id we are requesting to forward an HTLC to.
226                 requested_forward_scid: u64
227         },
228         /// Failure scenario where an HTLC may have been forwarded to be intended for us,
229         /// but is invalid for some reason, so we reject it.
230         ///
231         /// Some of the reasons may include:
232         /// * HTLC Timeouts
233         /// * Expected MPP amount to claim does not equal HTLC total
234         /// * Claimable amount does not match expected amount
235         FailedPayment {
236                 /// The payment hash of the payment we attempted to process.
237                 payment_hash: PaymentHash
238         },
239 }
240
241 impl_writeable_tlv_based_enum_upgradable!(HTLCDestination,
242         (0, NextHopChannel) => {
243                 (0, node_id, required),
244                 (2, channel_id, required),
245         },
246         (1, InvalidForward) => {
247                 (0, requested_forward_scid, required),
248         },
249         (2, UnknownNextHop) => {
250                 (0, requested_forward_scid, required),
251         },
252         (4, FailedPayment) => {
253                 (0, payment_hash, required),
254         },
255 );
256
257 /// Will be used in [`Event::HTLCIntercepted`] to identify the next hop in the HTLC's path.
258 /// Currently only used in serialization for the sake of maintaining compatibility. More variants
259 /// will be added for general-purpose HTLC forward intercepts as well as trampoline forward
260 /// intercepts in upcoming work.
261 enum InterceptNextHop {
262         FakeScid {
263                 requested_next_hop_scid: u64,
264         },
265 }
266
267 impl_writeable_tlv_based_enum!(InterceptNextHop,
268         (0, FakeScid) => {
269                 (0, requested_next_hop_scid, required),
270         };
271 );
272
273 /// An Event which you should probably take some action in response to.
274 ///
275 /// Note that while Writeable and Readable are implemented for Event, you probably shouldn't use
276 /// them directly as they don't round-trip exactly (for example FundingGenerationReady is never
277 /// written as it makes no sense to respond to it after reconnecting to peers).
278 #[derive(Clone, Debug, PartialEq, Eq)]
279 pub enum Event {
280         /// Used to indicate that the client should generate a funding transaction with the given
281         /// parameters and then call [`ChannelManager::funding_transaction_generated`].
282         /// Generated in [`ChannelManager`] message handling.
283         /// Note that *all inputs* in the funding transaction must spend SegWit outputs or your
284         /// counterparty can steal your funds!
285         ///
286         /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
287         /// [`ChannelManager::funding_transaction_generated`]: crate::ln::channelmanager::ChannelManager::funding_transaction_generated
288         FundingGenerationReady {
289                 /// The random channel_id we picked which you'll need to pass into
290                 /// [`ChannelManager::funding_transaction_generated`].
291                 ///
292                 /// [`ChannelManager::funding_transaction_generated`]: crate::ln::channelmanager::ChannelManager::funding_transaction_generated
293                 temporary_channel_id: [u8; 32],
294                 /// The counterparty's node_id, which you'll need to pass back into
295                 /// [`ChannelManager::funding_transaction_generated`].
296                 ///
297                 /// [`ChannelManager::funding_transaction_generated`]: crate::ln::channelmanager::ChannelManager::funding_transaction_generated
298                 counterparty_node_id: PublicKey,
299                 /// The value, in satoshis, that the output should have.
300                 channel_value_satoshis: u64,
301                 /// The script which should be used in the transaction output.
302                 output_script: Script,
303                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`], or a
304                 /// random value for an inbound channel. This may be zero for objects serialized with LDK
305                 /// versions prior to 0.0.113.
306                 ///
307                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
308                 user_channel_id: u128,
309         },
310         /// Indicates that we've been offered a payment and it needs to be claimed via calling
311         /// [`ChannelManager::claim_funds`] with the preimage given in [`PaymentPurpose`].
312         ///
313         /// Note that if the preimage is not known, you should call
314         /// [`ChannelManager::fail_htlc_backwards`] or [`ChannelManager::fail_htlc_backwards_with_reason`]
315         /// to free up resources for this HTLC and avoid network congestion.
316         /// If you fail to call either [`ChannelManager::claim_funds`], [`ChannelManager::fail_htlc_backwards`],
317         /// or [`ChannelManager::fail_htlc_backwards_with_reason`] within the HTLC's timeout, the HTLC will be
318         /// automatically failed.
319         ///
320         /// # Note
321         /// LDK will not stop an inbound payment from being paid multiple times, so multiple
322         /// `PaymentClaimable` events may be generated for the same payment.
323         ///
324         /// # Note
325         /// This event used to be called `PaymentReceived` in LDK versions 0.0.112 and earlier.
326         ///
327         /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
328         /// [`ChannelManager::fail_htlc_backwards`]: crate::ln::channelmanager::ChannelManager::fail_htlc_backwards
329         /// [`ChannelManager::fail_htlc_backwards_with_reason`]: crate::ln::channelmanager::ChannelManager::fail_htlc_backwards_with_reason
330         PaymentClaimable {
331                 /// The node that will receive the payment after it has been claimed.
332                 /// This is useful to identify payments received via [phantom nodes].
333                 /// This field will always be filled in when the event was generated by LDK versions
334                 /// 0.0.113 and above.
335                 ///
336                 /// [phantom nodes]: crate::chain::keysinterface::PhantomKeysManager
337                 receiver_node_id: Option<PublicKey>,
338                 /// The hash for which the preimage should be handed to the ChannelManager. Note that LDK will
339                 /// not stop you from registering duplicate payment hashes for inbound payments.
340                 payment_hash: PaymentHash,
341                 /// The value, in thousandths of a satoshi, that this payment is for.
342                 amount_msat: u64,
343                 /// Information for claiming this received payment, based on whether the purpose of the
344                 /// payment is to pay an invoice or to send a spontaneous payment.
345                 purpose: PaymentPurpose,
346                 /// The `channel_id` indicating over which channel we received the payment.
347                 via_channel_id: Option<[u8; 32]>,
348                 /// The `user_channel_id` indicating over which channel we received the payment.
349                 via_user_channel_id: Option<u128>,
350         },
351         /// Indicates a payment has been claimed and we've received money!
352         ///
353         /// This most likely occurs when [`ChannelManager::claim_funds`] has been called in response
354         /// to an [`Event::PaymentClaimable`]. However, if we previously crashed during a
355         /// [`ChannelManager::claim_funds`] call you may see this event without a corresponding
356         /// [`Event::PaymentClaimable`] event.
357         ///
358         /// # Note
359         /// LDK will not stop an inbound payment from being paid multiple times, so multiple
360         /// `PaymentClaimable` events may be generated for the same payment. If you then call
361         /// [`ChannelManager::claim_funds`] twice for the same [`Event::PaymentClaimable`] you may get
362         /// multiple `PaymentClaimed` events.
363         ///
364         /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
365         PaymentClaimed {
366                 /// The node that received the payment.
367                 /// This is useful to identify payments which were received via [phantom nodes].
368                 /// This field will always be filled in when the event was generated by LDK versions
369                 /// 0.0.113 and above.
370                 ///
371                 /// [phantom nodes]: crate::chain::keysinterface::PhantomKeysManager
372                 receiver_node_id: Option<PublicKey>,
373                 /// The payment hash of the claimed payment. Note that LDK will not stop you from
374                 /// registering duplicate payment hashes for inbound payments.
375                 payment_hash: PaymentHash,
376                 /// The value, in thousandths of a satoshi, that this payment is for.
377                 amount_msat: u64,
378                 /// The purpose of the claimed payment, i.e. whether the payment was for an invoice or a
379                 /// spontaneous payment.
380                 purpose: PaymentPurpose,
381         },
382         /// Indicates an outbound payment we made succeeded (i.e. it made it all the way to its target
383         /// and we got back the payment preimage for it).
384         ///
385         /// Note for MPP payments: in rare cases, this event may be preceded by a `PaymentPathFailed`
386         /// event. In this situation, you SHOULD treat this payment as having succeeded.
387         PaymentSent {
388                 /// The id returned by [`ChannelManager::send_payment`].
389                 ///
390                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
391                 payment_id: Option<PaymentId>,
392                 /// The preimage to the hash given to ChannelManager::send_payment.
393                 /// Note that this serves as a payment receipt, if you wish to have such a thing, you must
394                 /// store it somehow!
395                 payment_preimage: PaymentPreimage,
396                 /// The hash that was given to [`ChannelManager::send_payment`].
397                 ///
398                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
399                 payment_hash: PaymentHash,
400                 /// The total fee which was spent at intermediate hops in this payment, across all paths.
401                 ///
402                 /// Note that, like [`Route::get_total_fees`] this does *not* include any potential
403                 /// overpayment to the recipient node.
404                 ///
405                 /// If the recipient or an intermediate node misbehaves and gives us free money, this may
406                 /// overstate the amount paid, though this is unlikely.
407                 ///
408                 /// [`Route::get_total_fees`]: crate::routing::router::Route::get_total_fees
409                 fee_paid_msat: Option<u64>,
410         },
411         /// Indicates an outbound payment failed. Individual [`Event::PaymentPathFailed`] events
412         /// provide failure information for each path attempt in the payment, including retries.
413         ///
414         /// This event is provided once there are no further pending HTLCs for the payment and the
415         /// payment is no longer retryable, due either to the [`Retry`] provided or
416         /// [`ChannelManager::abandon_payment`] having been called for the corresponding payment.
417         ///
418         /// [`Retry`]: crate::ln::channelmanager::Retry
419         /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
420         PaymentFailed {
421                 /// The id returned by [`ChannelManager::send_payment`] and used with
422                 /// [`ChannelManager::abandon_payment`].
423                 ///
424                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
425                 /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
426                 payment_id: PaymentId,
427                 /// The hash that was given to [`ChannelManager::send_payment`].
428                 ///
429                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
430                 payment_hash: PaymentHash,
431         },
432         /// Indicates that a path for an outbound payment was successful.
433         ///
434         /// Always generated after [`Event::PaymentSent`] and thus useful for scoring channels. See
435         /// [`Event::PaymentSent`] for obtaining the payment preimage.
436         PaymentPathSuccessful {
437                 /// The id returned by [`ChannelManager::send_payment`].
438                 ///
439                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
440                 payment_id: PaymentId,
441                 /// The hash that was given to [`ChannelManager::send_payment`].
442                 ///
443                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
444                 payment_hash: Option<PaymentHash>,
445                 /// The payment path that was successful.
446                 ///
447                 /// May contain a closed channel if the HTLC sent along the path was fulfilled on chain.
448                 path: Vec<RouteHop>,
449         },
450         /// Indicates an outbound HTLC we sent failed, likely due to an intermediary node being unable to
451         /// handle the HTLC.
452         ///
453         /// Note that this does *not* indicate that all paths for an MPP payment have failed, see
454         /// [`Event::PaymentFailed`].
455         ///
456         /// See [`ChannelManager::abandon_payment`] for giving up on this payment before its retries have
457         /// been exhausted.
458         ///
459         /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
460         PaymentPathFailed {
461                 /// The id returned by [`ChannelManager::send_payment`] and used with
462                 /// [`ChannelManager::abandon_payment`].
463                 ///
464                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
465                 /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
466                 payment_id: Option<PaymentId>,
467                 /// The hash that was given to [`ChannelManager::send_payment`].
468                 ///
469                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
470                 payment_hash: PaymentHash,
471                 /// Indicates the payment was rejected for some reason by the recipient. This implies that
472                 /// the payment has failed, not just the route in question. If this is not set, the payment may
473                 /// be retried via a different route.
474                 payment_failed_permanently: bool,
475                 /// Extra error details based on the failure type. May contain an update that needs to be
476                 /// applied to the [`NetworkGraph`].
477                 ///
478                 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
479                 failure: PathFailure,
480                 /// The payment path that failed.
481                 path: Vec<RouteHop>,
482                 /// The channel responsible for the failed payment path.
483                 ///
484                 /// Note that for route hints or for the first hop in a path this may be an SCID alias and
485                 /// may not refer to a channel in the public network graph. These aliases may also collide
486                 /// with channels in the public network graph.
487                 ///
488                 /// If this is `Some`, then the corresponding channel should be avoided when the payment is
489                 /// retried. May be `None` for older [`Event`] serializations.
490                 short_channel_id: Option<u64>,
491 #[cfg(test)]
492                 error_code: Option<u16>,
493 #[cfg(test)]
494                 error_data: Option<Vec<u8>>,
495         },
496         /// Indicates that a probe payment we sent returned successful, i.e., only failed at the destination.
497         ProbeSuccessful {
498                 /// The id returned by [`ChannelManager::send_probe`].
499                 ///
500                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
501                 payment_id: PaymentId,
502                 /// The hash generated by [`ChannelManager::send_probe`].
503                 ///
504                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
505                 payment_hash: PaymentHash,
506                 /// The payment path that was successful.
507                 path: Vec<RouteHop>,
508         },
509         /// Indicates that a probe payment we sent failed at an intermediary node on the path.
510         ProbeFailed {
511                 /// The id returned by [`ChannelManager::send_probe`].
512                 ///
513                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
514                 payment_id: PaymentId,
515                 /// The hash generated by [`ChannelManager::send_probe`].
516                 ///
517                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
518                 payment_hash: PaymentHash,
519                 /// The payment path that failed.
520                 path: Vec<RouteHop>,
521                 /// The channel responsible for the failed probe.
522                 ///
523                 /// Note that for route hints or for the first hop in a path this may be an SCID alias and
524                 /// may not refer to a channel in the public network graph. These aliases may also collide
525                 /// with channels in the public network graph.
526                 short_channel_id: Option<u64>,
527         },
528         /// Used to indicate that [`ChannelManager::process_pending_htlc_forwards`] should be called at
529         /// a time in the future.
530         ///
531         /// [`ChannelManager::process_pending_htlc_forwards`]: crate::ln::channelmanager::ChannelManager::process_pending_htlc_forwards
532         PendingHTLCsForwardable {
533                 /// The minimum amount of time that should be waited prior to calling
534                 /// process_pending_htlc_forwards. To increase the effort required to correlate payments,
535                 /// you should wait a random amount of time in roughly the range (now + time_forwardable,
536                 /// now + 5*time_forwardable).
537                 time_forwardable: Duration,
538         },
539         /// Used to indicate that we've intercepted an HTLC forward. This event will only be generated if
540         /// you've encoded an intercept scid in the receiver's invoice route hints using
541         /// [`ChannelManager::get_intercept_scid`] and have set [`UserConfig::accept_intercept_htlcs`].
542         ///
543         /// [`ChannelManager::forward_intercepted_htlc`] or
544         /// [`ChannelManager::fail_intercepted_htlc`] MUST be called in response to this event. See
545         /// their docs for more information.
546         ///
547         /// [`ChannelManager::get_intercept_scid`]: crate::ln::channelmanager::ChannelManager::get_intercept_scid
548         /// [`UserConfig::accept_intercept_htlcs`]: crate::util::config::UserConfig::accept_intercept_htlcs
549         /// [`ChannelManager::forward_intercepted_htlc`]: crate::ln::channelmanager::ChannelManager::forward_intercepted_htlc
550         /// [`ChannelManager::fail_intercepted_htlc`]: crate::ln::channelmanager::ChannelManager::fail_intercepted_htlc
551         HTLCIntercepted {
552                 /// An id to help LDK identify which HTLC is being forwarded or failed.
553                 intercept_id: InterceptId,
554                 /// The fake scid that was programmed as the next hop's scid, generated using
555                 /// [`ChannelManager::get_intercept_scid`].
556                 ///
557                 /// [`ChannelManager::get_intercept_scid`]: crate::ln::channelmanager::ChannelManager::get_intercept_scid
558                 requested_next_hop_scid: u64,
559                 /// The payment hash used for this HTLC.
560                 payment_hash: PaymentHash,
561                 /// How many msats were received on the inbound edge of this HTLC.
562                 inbound_amount_msat: u64,
563                 /// How many msats the payer intended to route to the next node. Depending on the reason you are
564                 /// intercepting this payment, you might take a fee by forwarding less than this amount.
565                 ///
566                 /// Note that LDK will NOT check that expected fees were factored into this value. You MUST
567                 /// check that whatever fee you want has been included here or subtract it as required. Further,
568                 /// LDK will not stop you from forwarding more than you received.
569                 expected_outbound_amount_msat: u64,
570         },
571         /// Used to indicate that an output which you should know how to spend was confirmed on chain
572         /// and is now spendable.
573         /// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
574         /// counterparty spending them due to some kind of timeout. Thus, you need to store them
575         /// somewhere and spend them when you create on-chain transactions.
576         SpendableOutputs {
577                 /// The outputs which you should store as spendable by you.
578                 outputs: Vec<SpendableOutputDescriptor>,
579         },
580         /// This event is generated when a payment has been successfully forwarded through us and a
581         /// forwarding fee earned.
582         PaymentForwarded {
583                 /// The incoming channel between the previous node and us. This is only `None` for events
584                 /// generated or serialized by versions prior to 0.0.107.
585                 prev_channel_id: Option<[u8; 32]>,
586                 /// The outgoing channel between the next node and us. This is only `None` for events
587                 /// generated or serialized by versions prior to 0.0.107.
588                 next_channel_id: Option<[u8; 32]>,
589                 /// The fee, in milli-satoshis, which was earned as a result of the payment.
590                 ///
591                 /// Note that if we force-closed the channel over which we forwarded an HTLC while the HTLC
592                 /// was pending, the amount the next hop claimed will have been rounded down to the nearest
593                 /// whole satoshi. Thus, the fee calculated here may be higher than expected as we still
594                 /// claimed the full value in millisatoshis from the source. In this case,
595                 /// `claim_from_onchain_tx` will be set.
596                 ///
597                 /// If the channel which sent us the payment has been force-closed, we will claim the funds
598                 /// via an on-chain transaction. In that case we do not yet know the on-chain transaction
599                 /// fees which we will spend and will instead set this to `None`. It is possible duplicate
600                 /// `PaymentForwarded` events are generated for the same payment iff `fee_earned_msat` is
601                 /// `None`.
602                 fee_earned_msat: Option<u64>,
603                 /// If this is `true`, the forwarded HTLC was claimed by our counterparty via an on-chain
604                 /// transaction.
605                 claim_from_onchain_tx: bool,
606         },
607         /// Used to indicate that a channel with the given `channel_id` is ready to
608         /// be used. This event is emitted either when the funding transaction has been confirmed
609         /// on-chain, or, in case of a 0conf channel, when both parties have confirmed the channel
610         /// establishment.
611         ChannelReady {
612                 /// The channel_id of the channel that is ready.
613                 channel_id: [u8; 32],
614                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
615                 /// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
616                 /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
617                 /// `user_channel_id` will be randomized for an inbound channel.
618                 ///
619                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
620                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
621                 /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
622                 user_channel_id: u128,
623                 /// The node_id of the channel counterparty.
624                 counterparty_node_id: PublicKey,
625                 /// The features that this channel will operate with.
626                 channel_type: ChannelTypeFeatures,
627         },
628         /// Used to indicate that a previously opened channel with the given `channel_id` is in the
629         /// process of closure.
630         ChannelClosed  {
631                 /// The channel_id of the channel which has been closed. Note that on-chain transactions
632                 /// resolving the channel are likely still awaiting confirmation.
633                 channel_id: [u8; 32],
634                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
635                 /// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
636                 /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
637                 /// `user_channel_id` will be randomized for inbound channels.
638                 /// This may be zero for inbound channels serialized prior to 0.0.113 and will always be
639                 /// zero for objects serialized with LDK versions prior to 0.0.102.
640                 ///
641                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
642                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
643                 /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
644                 user_channel_id: u128,
645                 /// The reason the channel was closed.
646                 reason: ClosureReason
647         },
648         /// Used to indicate to the user that they can abandon the funding transaction and recycle the
649         /// inputs for another purpose.
650         DiscardFunding {
651                 /// The channel_id of the channel which has been closed.
652                 channel_id: [u8; 32],
653                 /// The full transaction received from the user
654                 transaction: Transaction
655         },
656         /// Indicates a request to open a new channel by a peer.
657         ///
658         /// To accept the request, call [`ChannelManager::accept_inbound_channel`]. To reject the
659         /// request, call [`ChannelManager::force_close_without_broadcasting_txn`].
660         ///
661         /// The event is only triggered when a new open channel request is received and the
662         /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true.
663         ///
664         /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
665         /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
666         /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
667         OpenChannelRequest {
668                 /// The temporary channel ID of the channel requested to be opened.
669                 ///
670                 /// When responding to the request, the `temporary_channel_id` should be passed
671                 /// back to the ChannelManager through [`ChannelManager::accept_inbound_channel`] to accept,
672                 /// or through [`ChannelManager::force_close_without_broadcasting_txn`] to reject.
673                 ///
674                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
675                 /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
676                 temporary_channel_id: [u8; 32],
677                 /// The node_id of the counterparty requesting to open the channel.
678                 ///
679                 /// When responding to the request, the `counterparty_node_id` should be passed
680                 /// back to the `ChannelManager` through [`ChannelManager::accept_inbound_channel`] to
681                 /// accept the request, or through [`ChannelManager::force_close_without_broadcasting_txn`] to reject the
682                 /// request.
683                 ///
684                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
685                 /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
686                 counterparty_node_id: PublicKey,
687                 /// The channel value of the requested channel.
688                 funding_satoshis: u64,
689                 /// Our starting balance in the channel if the request is accepted, in milli-satoshi.
690                 push_msat: u64,
691                 /// The features that this channel will operate with. If you reject the channel, a
692                 /// well-behaved counterparty may automatically re-attempt the channel with a new set of
693                 /// feature flags.
694                 ///
695                 /// Note that if [`ChannelTypeFeatures::supports_scid_privacy`] returns true on this type,
696                 /// the resulting [`ChannelManager`] will not be readable by versions of LDK prior to
697                 /// 0.0.106.
698                 ///
699                 /// Furthermore, note that if [`ChannelTypeFeatures::supports_zero_conf`] returns true on this type,
700                 /// the resulting [`ChannelManager`] will not be readable by versions of LDK prior to
701                 /// 0.0.107. Channels setting this type also need to get manually accepted via
702                 /// [`crate::ln::channelmanager::ChannelManager::accept_inbound_channel_from_trusted_peer_0conf`],
703                 /// or will be rejected otherwise.
704                 ///
705                 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
706                 channel_type: ChannelTypeFeatures,
707         },
708         /// Indicates that the HTLC was accepted, but could not be processed when or after attempting to
709         /// forward it.
710         ///
711         /// Some scenarios where this event may be sent include:
712         /// * Insufficient capacity in the outbound channel
713         /// * While waiting to forward the HTLC, the channel it is meant to be forwarded through closes
714         /// * When an unknown SCID is requested for forwarding a payment.
715         /// * Claiming an amount for an MPP payment that exceeds the HTLC total
716         /// * The HTLC has timed out
717         ///
718         /// This event, however, does not get generated if an HTLC fails to meet the forwarding
719         /// requirements (i.e. insufficient fees paid, or a CLTV that is too soon).
720         HTLCHandlingFailed {
721                 /// The channel over which the HTLC was received.
722                 prev_channel_id: [u8; 32],
723                 /// Destination of the HTLC that failed to be processed.
724                 failed_next_destination: HTLCDestination,
725         },
726         #[cfg(anchors)]
727         /// Indicates that a transaction originating from LDK needs to have its fee bumped. This event
728         /// requires confirmed external funds to be readily available to spend.
729         ///
730         /// LDK does not currently generate this event. It is limited to the scope of channels with
731         /// anchor outputs, which will be introduced in a future release.
732         BumpTransaction(BumpTransactionEvent),
733 }
734
735 impl Writeable for Event {
736         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
737                 match self {
738                         &Event::FundingGenerationReady { .. } => {
739                                 0u8.write(writer)?;
740                                 // We never write out FundingGenerationReady events as, upon disconnection, peers
741                                 // drop any channels which have not yet exchanged funding_signed.
742                         },
743                         &Event::PaymentClaimable { ref payment_hash, ref amount_msat, ref purpose, ref receiver_node_id, ref via_channel_id, ref via_user_channel_id } => {
744                                 1u8.write(writer)?;
745                                 let mut payment_secret = None;
746                                 let payment_preimage;
747                                 match &purpose {
748                                         PaymentPurpose::InvoicePayment { payment_preimage: preimage, payment_secret: secret } => {
749                                                 payment_secret = Some(secret);
750                                                 payment_preimage = *preimage;
751                                         },
752                                         PaymentPurpose::SpontaneousPayment(preimage) => {
753                                                 payment_preimage = Some(*preimage);
754                                         }
755                                 }
756                                 write_tlv_fields!(writer, {
757                                         (0, payment_hash, required),
758                                         (1, receiver_node_id, option),
759                                         (2, payment_secret, option),
760                                         (3, via_channel_id, option),
761                                         (4, amount_msat, required),
762                                         (5, via_user_channel_id, option),
763                                         (6, 0u64, required), // user_payment_id required for compatibility with 0.0.103 and earlier
764                                         (8, payment_preimage, option),
765                                 });
766                         },
767                         &Event::PaymentSent { ref payment_id, ref payment_preimage, ref payment_hash, ref fee_paid_msat } => {
768                                 2u8.write(writer)?;
769                                 write_tlv_fields!(writer, {
770                                         (0, payment_preimage, required),
771                                         (1, payment_hash, required),
772                                         (3, payment_id, option),
773                                         (5, fee_paid_msat, option),
774                                 });
775                         },
776                         &Event::PaymentPathFailed {
777                                 ref payment_id, ref payment_hash, ref payment_failed_permanently, ref failure,
778                                 ref path, ref short_channel_id,
779                                 #[cfg(test)]
780                                 ref error_code,
781                                 #[cfg(test)]
782                                 ref error_data,
783                         } => {
784                                 3u8.write(writer)?;
785                                 #[cfg(test)]
786                                 error_code.write(writer)?;
787                                 #[cfg(test)]
788                                 error_data.write(writer)?;
789                                 write_tlv_fields!(writer, {
790                                         (0, payment_hash, required),
791                                         (1, None::<NetworkUpdate>, option), // network_update in LDK versions prior to 0.0.114
792                                         (2, payment_failed_permanently, required),
793                                         (3, false, required), // all_paths_failed in LDK versions prior to 0.0.114
794                                         (5, *path, vec_type),
795                                         (7, short_channel_id, option),
796                                         (9, None::<RouteParameters>, option), // retry in LDK versions prior to 0.0.115
797                                         (11, payment_id, option),
798                                         (13, failure, required),
799                                 });
800                         },
801                         &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
802                                 4u8.write(writer)?;
803                                 // Note that we now ignore these on the read end as we'll re-generate them in
804                                 // ChannelManager, we write them here only for backwards compatibility.
805                         },
806                         &Event::SpendableOutputs { ref outputs } => {
807                                 5u8.write(writer)?;
808                                 write_tlv_fields!(writer, {
809                                         (0, WithoutLength(outputs), required),
810                                 });
811                         },
812                         &Event::HTLCIntercepted { requested_next_hop_scid, payment_hash, inbound_amount_msat, expected_outbound_amount_msat, intercept_id } => {
813                                 6u8.write(writer)?;
814                                 let intercept_scid = InterceptNextHop::FakeScid { requested_next_hop_scid };
815                                 write_tlv_fields!(writer, {
816                                         (0, intercept_id, required),
817                                         (2, intercept_scid, required),
818                                         (4, payment_hash, required),
819                                         (6, inbound_amount_msat, required),
820                                         (8, expected_outbound_amount_msat, required),
821                                 });
822                         }
823                         &Event::PaymentForwarded { fee_earned_msat, prev_channel_id, claim_from_onchain_tx, next_channel_id } => {
824                                 7u8.write(writer)?;
825                                 write_tlv_fields!(writer, {
826                                         (0, fee_earned_msat, option),
827                                         (1, prev_channel_id, option),
828                                         (2, claim_from_onchain_tx, required),
829                                         (3, next_channel_id, option),
830                                 });
831                         },
832                         &Event::ChannelClosed { ref channel_id, ref user_channel_id, ref reason } => {
833                                 9u8.write(writer)?;
834                                 // `user_channel_id` used to be a single u64 value. In order to remain backwards
835                                 // compatible with versions prior to 0.0.113, the u128 is serialized as two
836                                 // separate u64 values.
837                                 let user_channel_id_low = *user_channel_id as u64;
838                                 let user_channel_id_high = (*user_channel_id >> 64) as u64;
839                                 write_tlv_fields!(writer, {
840                                         (0, channel_id, required),
841                                         (1, user_channel_id_low, required),
842                                         (2, reason, required),
843                                         (3, user_channel_id_high, required),
844                                 });
845                         },
846                         &Event::DiscardFunding { ref channel_id, ref transaction } => {
847                                 11u8.write(writer)?;
848                                 write_tlv_fields!(writer, {
849                                         (0, channel_id, required),
850                                         (2, transaction, required)
851                                 })
852                         },
853                         &Event::PaymentPathSuccessful { ref payment_id, ref payment_hash, ref path } => {
854                                 13u8.write(writer)?;
855                                 write_tlv_fields!(writer, {
856                                         (0, payment_id, required),
857                                         (2, payment_hash, option),
858                                         (4, *path, vec_type)
859                                 })
860                         },
861                         &Event::PaymentFailed { ref payment_id, ref payment_hash } => {
862                                 15u8.write(writer)?;
863                                 write_tlv_fields!(writer, {
864                                         (0, payment_id, required),
865                                         (2, payment_hash, required),
866                                 })
867                         },
868                         &Event::OpenChannelRequest { .. } => {
869                                 17u8.write(writer)?;
870                                 // We never write the OpenChannelRequest events as, upon disconnection, peers
871                                 // drop any channels which have not yet exchanged funding_signed.
872                         },
873                         &Event::PaymentClaimed { ref payment_hash, ref amount_msat, ref purpose, ref receiver_node_id } => {
874                                 19u8.write(writer)?;
875                                 write_tlv_fields!(writer, {
876                                         (0, payment_hash, required),
877                                         (1, receiver_node_id, option),
878                                         (2, purpose, required),
879                                         (4, amount_msat, required),
880                                 });
881                         },
882                         &Event::ProbeSuccessful { ref payment_id, ref payment_hash, ref path } => {
883                                 21u8.write(writer)?;
884                                 write_tlv_fields!(writer, {
885                                         (0, payment_id, required),
886                                         (2, payment_hash, required),
887                                         (4, *path, vec_type)
888                                 })
889                         },
890                         &Event::ProbeFailed { ref payment_id, ref payment_hash, ref path, ref short_channel_id } => {
891                                 23u8.write(writer)?;
892                                 write_tlv_fields!(writer, {
893                                         (0, payment_id, required),
894                                         (2, payment_hash, required),
895                                         (4, *path, vec_type),
896                                         (6, short_channel_id, option),
897                                 })
898                         },
899                         &Event::HTLCHandlingFailed { ref prev_channel_id, ref failed_next_destination } => {
900                                 25u8.write(writer)?;
901                                 write_tlv_fields!(writer, {
902                                         (0, prev_channel_id, required),
903                                         (2, failed_next_destination, required),
904                                 })
905                         },
906                         #[cfg(anchors)]
907                         &Event::BumpTransaction(ref event)=> {
908                                 27u8.write(writer)?;
909                                 match event {
910                                         // We never write the ChannelClose|HTLCResolution events as they'll be replayed
911                                         // upon restarting anyway if they remain unresolved.
912                                         BumpTransactionEvent::ChannelClose { .. } => {}
913                                         BumpTransactionEvent::HTLCResolution { .. } => {}
914                                 }
915                                 write_tlv_fields!(writer, {}); // Write a length field for forwards compat
916                         }
917                         &Event::ChannelReady { ref channel_id, ref user_channel_id, ref counterparty_node_id, ref channel_type } => {
918                                 29u8.write(writer)?;
919                                 write_tlv_fields!(writer, {
920                                         (0, channel_id, required),
921                                         (2, user_channel_id, required),
922                                         (4, counterparty_node_id, required),
923                                         (6, channel_type, required),
924                                 });
925                         },
926                         // Note that, going forward, all new events must only write data inside of
927                         // `write_tlv_fields`. Versions 0.0.101+ will ignore odd-numbered events that write
928                         // data via `write_tlv_fields`.
929                 }
930                 Ok(())
931         }
932 }
933 impl MaybeReadable for Event {
934         fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
935                 match Readable::read(reader)? {
936                         // Note that we do not write a length-prefixed TLV for FundingGenerationReady events,
937                         // unlike all other events, thus we return immediately here.
938                         0u8 => Ok(None),
939                         1u8 => {
940                                 let f = || {
941                                         let mut payment_hash = PaymentHash([0; 32]);
942                                         let mut payment_preimage = None;
943                                         let mut payment_secret = None;
944                                         let mut amount_msat = 0;
945                                         let mut receiver_node_id = None;
946                                         let mut _user_payment_id = None::<u64>; // For compatibility with 0.0.103 and earlier
947                                         let mut via_channel_id = None;
948                                         let mut via_user_channel_id = None;
949                                         read_tlv_fields!(reader, {
950                                                 (0, payment_hash, required),
951                                                 (1, receiver_node_id, option),
952                                                 (2, payment_secret, option),
953                                                 (3, via_channel_id, option),
954                                                 (4, amount_msat, required),
955                                                 (5, via_user_channel_id, option),
956                                                 (6, _user_payment_id, option),
957                                                 (8, payment_preimage, option),
958                                         });
959                                         let purpose = match payment_secret {
960                                                 Some(secret) => PaymentPurpose::InvoicePayment {
961                                                         payment_preimage,
962                                                         payment_secret: secret
963                                                 },
964                                                 None if payment_preimage.is_some() => PaymentPurpose::SpontaneousPayment(payment_preimage.unwrap()),
965                                                 None => return Err(msgs::DecodeError::InvalidValue),
966                                         };
967                                         Ok(Some(Event::PaymentClaimable {
968                                                 receiver_node_id,
969                                                 payment_hash,
970                                                 amount_msat,
971                                                 purpose,
972                                                 via_channel_id,
973                                                 via_user_channel_id,
974                                         }))
975                                 };
976                                 f()
977                         },
978                         2u8 => {
979                                 let f = || {
980                                         let mut payment_preimage = PaymentPreimage([0; 32]);
981                                         let mut payment_hash = None;
982                                         let mut payment_id = None;
983                                         let mut fee_paid_msat = None;
984                                         read_tlv_fields!(reader, {
985                                                 (0, payment_preimage, required),
986                                                 (1, payment_hash, option),
987                                                 (3, payment_id, option),
988                                                 (5, fee_paid_msat, option),
989                                         });
990                                         if payment_hash.is_none() {
991                                                 payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()));
992                                         }
993                                         Ok(Some(Event::PaymentSent {
994                                                 payment_id,
995                                                 payment_preimage,
996                                                 payment_hash: payment_hash.unwrap(),
997                                                 fee_paid_msat,
998                                         }))
999                                 };
1000                                 f()
1001                         },
1002                         3u8 => {
1003                                 let f = || {
1004                                         #[cfg(test)]
1005                                         let error_code = Readable::read(reader)?;
1006                                         #[cfg(test)]
1007                                         let error_data = Readable::read(reader)?;
1008                                         let mut payment_hash = PaymentHash([0; 32]);
1009                                         let mut payment_failed_permanently = false;
1010                                         let mut network_update = None;
1011                                         let mut path: Option<Vec<RouteHop>> = Some(vec![]);
1012                                         let mut short_channel_id = None;
1013                                         let mut payment_id = None;
1014                                         let mut failure_opt = None;
1015                                         read_tlv_fields!(reader, {
1016                                                 (0, payment_hash, required),
1017                                                 (1, network_update, upgradable_option),
1018                                                 (2, payment_failed_permanently, required),
1019                                                 (5, path, vec_type),
1020                                                 (7, short_channel_id, option),
1021                                                 (11, payment_id, option),
1022                                                 (13, failure_opt, upgradable_option),
1023                                         });
1024                                         let failure = failure_opt.unwrap_or_else(|| PathFailure::OnPath { network_update });
1025                                         Ok(Some(Event::PaymentPathFailed {
1026                                                 payment_id,
1027                                                 payment_hash,
1028                                                 payment_failed_permanently,
1029                                                 failure,
1030                                                 path: path.unwrap(),
1031                                                 short_channel_id,
1032                                                 #[cfg(test)]
1033                                                 error_code,
1034                                                 #[cfg(test)]
1035                                                 error_data,
1036                                         }))
1037                                 };
1038                                 f()
1039                         },
1040                         4u8 => Ok(None),
1041                         5u8 => {
1042                                 let f = || {
1043                                         let mut outputs = WithoutLength(Vec::new());
1044                                         read_tlv_fields!(reader, {
1045                                                 (0, outputs, required),
1046                                         });
1047                                         Ok(Some(Event::SpendableOutputs { outputs: outputs.0 }))
1048                                 };
1049                                 f()
1050                         },
1051                         6u8 => {
1052                                 let mut payment_hash = PaymentHash([0; 32]);
1053                                 let mut intercept_id = InterceptId([0; 32]);
1054                                 let mut requested_next_hop_scid = InterceptNextHop::FakeScid { requested_next_hop_scid: 0 };
1055                                 let mut inbound_amount_msat = 0;
1056                                 let mut expected_outbound_amount_msat = 0;
1057                                 read_tlv_fields!(reader, {
1058                                         (0, intercept_id, required),
1059                                         (2, requested_next_hop_scid, required),
1060                                         (4, payment_hash, required),
1061                                         (6, inbound_amount_msat, required),
1062                                         (8, expected_outbound_amount_msat, required),
1063                                 });
1064                                 let next_scid = match requested_next_hop_scid {
1065                                         InterceptNextHop::FakeScid { requested_next_hop_scid: scid } => scid
1066                                 };
1067                                 Ok(Some(Event::HTLCIntercepted {
1068                                         payment_hash,
1069                                         requested_next_hop_scid: next_scid,
1070                                         inbound_amount_msat,
1071                                         expected_outbound_amount_msat,
1072                                         intercept_id,
1073                                 }))
1074                         },
1075                         7u8 => {
1076                                 let f = || {
1077                                         let mut fee_earned_msat = None;
1078                                         let mut prev_channel_id = None;
1079                                         let mut claim_from_onchain_tx = false;
1080                                         let mut next_channel_id = None;
1081                                         read_tlv_fields!(reader, {
1082                                                 (0, fee_earned_msat, option),
1083                                                 (1, prev_channel_id, option),
1084                                                 (2, claim_from_onchain_tx, required),
1085                                                 (3, next_channel_id, option),
1086                                         });
1087                                         Ok(Some(Event::PaymentForwarded { fee_earned_msat, prev_channel_id, claim_from_onchain_tx, next_channel_id }))
1088                                 };
1089                                 f()
1090                         },
1091                         9u8 => {
1092                                 let f = || {
1093                                         let mut channel_id = [0; 32];
1094                                         let mut reason = UpgradableRequired(None);
1095                                         let mut user_channel_id_low_opt: Option<u64> = None;
1096                                         let mut user_channel_id_high_opt: Option<u64> = None;
1097                                         read_tlv_fields!(reader, {
1098                                                 (0, channel_id, required),
1099                                                 (1, user_channel_id_low_opt, option),
1100                                                 (2, reason, upgradable_required),
1101                                                 (3, user_channel_id_high_opt, option),
1102                                         });
1103
1104                                         // `user_channel_id` used to be a single u64 value. In order to remain
1105                                         // backwards compatible with versions prior to 0.0.113, the u128 is serialized
1106                                         // as two separate u64 values.
1107                                         let user_channel_id = (user_channel_id_low_opt.unwrap_or(0) as u128) +
1108                                                 ((user_channel_id_high_opt.unwrap_or(0) as u128) << 64);
1109
1110                                         Ok(Some(Event::ChannelClosed { channel_id, user_channel_id, reason: _init_tlv_based_struct_field!(reason, upgradable_required) }))
1111                                 };
1112                                 f()
1113                         },
1114                         11u8 => {
1115                                 let f = || {
1116                                         let mut channel_id = [0; 32];
1117                                         let mut transaction = Transaction{ version: 2, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
1118                                         read_tlv_fields!(reader, {
1119                                                 (0, channel_id, required),
1120                                                 (2, transaction, required),
1121                                         });
1122                                         Ok(Some(Event::DiscardFunding { channel_id, transaction } ))
1123                                 };
1124                                 f()
1125                         },
1126                         13u8 => {
1127                                 let f = || {
1128                                         let mut payment_id = PaymentId([0; 32]);
1129                                         let mut payment_hash = None;
1130                                         let mut path: Option<Vec<RouteHop>> = Some(vec![]);
1131                                         read_tlv_fields!(reader, {
1132                                                 (0, payment_id, required),
1133                                                 (2, payment_hash, option),
1134                                                 (4, path, vec_type),
1135                                         });
1136                                         Ok(Some(Event::PaymentPathSuccessful {
1137                                                 payment_id,
1138                                                 payment_hash,
1139                                                 path: path.unwrap(),
1140                                         }))
1141                                 };
1142                                 f()
1143                         },
1144                         15u8 => {
1145                                 let f = || {
1146                                         let mut payment_hash = PaymentHash([0; 32]);
1147                                         let mut payment_id = PaymentId([0; 32]);
1148                                         read_tlv_fields!(reader, {
1149                                                 (0, payment_id, required),
1150                                                 (2, payment_hash, required),
1151                                         });
1152                                         Ok(Some(Event::PaymentFailed {
1153                                                 payment_id,
1154                                                 payment_hash,
1155                                         }))
1156                                 };
1157                                 f()
1158                         },
1159                         17u8 => {
1160                                 // Value 17 is used for `Event::OpenChannelRequest`.
1161                                 Ok(None)
1162                         },
1163                         19u8 => {
1164                                 let f = || {
1165                                         let mut payment_hash = PaymentHash([0; 32]);
1166                                         let mut purpose = UpgradableRequired(None);
1167                                         let mut amount_msat = 0;
1168                                         let mut receiver_node_id = None;
1169                                         read_tlv_fields!(reader, {
1170                                                 (0, payment_hash, required),
1171                                                 (1, receiver_node_id, option),
1172                                                 (2, purpose, upgradable_required),
1173                                                 (4, amount_msat, required),
1174                                         });
1175                                         Ok(Some(Event::PaymentClaimed {
1176                                                 receiver_node_id,
1177                                                 payment_hash,
1178                                                 purpose: _init_tlv_based_struct_field!(purpose, upgradable_required),
1179                                                 amount_msat,
1180                                         }))
1181                                 };
1182                                 f()
1183                         },
1184                         21u8 => {
1185                                 let f = || {
1186                                         let mut payment_id = PaymentId([0; 32]);
1187                                         let mut payment_hash = PaymentHash([0; 32]);
1188                                         let mut path: Option<Vec<RouteHop>> = Some(vec![]);
1189                                         read_tlv_fields!(reader, {
1190                                                 (0, payment_id, required),
1191                                                 (2, payment_hash, required),
1192                                                 (4, path, vec_type),
1193                                         });
1194                                         Ok(Some(Event::ProbeSuccessful {
1195                                                 payment_id,
1196                                                 payment_hash,
1197                                                 path: path.unwrap(),
1198                                         }))
1199                                 };
1200                                 f()
1201                         },
1202                         23u8 => {
1203                                 let f = || {
1204                                         let mut payment_id = PaymentId([0; 32]);
1205                                         let mut payment_hash = PaymentHash([0; 32]);
1206                                         let mut path: Option<Vec<RouteHop>> = Some(vec![]);
1207                                         let mut short_channel_id = None;
1208                                         read_tlv_fields!(reader, {
1209                                                 (0, payment_id, required),
1210                                                 (2, payment_hash, required),
1211                                                 (4, path, vec_type),
1212                                                 (6, short_channel_id, option),
1213                                         });
1214                                         Ok(Some(Event::ProbeFailed {
1215                                                 payment_id,
1216                                                 payment_hash,
1217                                                 path: path.unwrap(),
1218                                                 short_channel_id,
1219                                         }))
1220                                 };
1221                                 f()
1222                         },
1223                         25u8 => {
1224                                 let f = || {
1225                                         let mut prev_channel_id = [0; 32];
1226                                         let mut failed_next_destination_opt = UpgradableRequired(None);
1227                                         read_tlv_fields!(reader, {
1228                                                 (0, prev_channel_id, required),
1229                                                 (2, failed_next_destination_opt, upgradable_required),
1230                                         });
1231                                         Ok(Some(Event::HTLCHandlingFailed {
1232                                                 prev_channel_id,
1233                                                 failed_next_destination: _init_tlv_based_struct_field!(failed_next_destination_opt, upgradable_required),
1234                                         }))
1235                                 };
1236                                 f()
1237                         },
1238                         27u8 => Ok(None),
1239                         29u8 => {
1240                                 let f = || {
1241                                         let mut channel_id = [0; 32];
1242                                         let mut user_channel_id: u128 = 0;
1243                                         let mut counterparty_node_id = RequiredWrapper(None);
1244                                         let mut channel_type = RequiredWrapper(None);
1245                                         read_tlv_fields!(reader, {
1246                                                 (0, channel_id, required),
1247                                                 (2, user_channel_id, required),
1248                                                 (4, counterparty_node_id, required),
1249                                                 (6, channel_type, required),
1250                                         });
1251
1252                                         Ok(Some(Event::ChannelReady {
1253                                                 channel_id,
1254                                                 user_channel_id,
1255                                                 counterparty_node_id: counterparty_node_id.0.unwrap(),
1256                                                 channel_type: channel_type.0.unwrap()
1257                                         }))
1258                                 };
1259                                 f()
1260                         },
1261                         // Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue.
1262                         // Version 0.0.100 failed to properly ignore odd types, possibly resulting in corrupt
1263                         // reads.
1264                         x if x % 2 == 1 => {
1265                                 // If the event is of unknown type, assume it was written with `write_tlv_fields`,
1266                                 // which prefixes the whole thing with a length BigSize. Because the event is
1267                                 // odd-type unknown, we should treat it as `Ok(None)` even if it has some TLV
1268                                 // fields that are even. Thus, we avoid using `read_tlv_fields` and simply read
1269                                 // exactly the number of bytes specified, ignoring them entirely.
1270                                 let tlv_len: BigSize = Readable::read(reader)?;
1271                                 FixedLengthReader::new(reader, tlv_len.0)
1272                                         .eat_remaining().map_err(|_| msgs::DecodeError::ShortRead)?;
1273                                 Ok(None)
1274                         },
1275                         _ => Err(msgs::DecodeError::InvalidValue)
1276                 }
1277         }
1278 }
1279
1280 /// An event generated by ChannelManager which indicates a message should be sent to a peer (or
1281 /// broadcast to most peers).
1282 /// These events are handled by PeerManager::process_events if you are using a PeerManager.
1283 #[derive(Clone, Debug)]
1284 pub enum MessageSendEvent {
1285         /// Used to indicate that we've accepted a channel open and should send the accept_channel
1286         /// message provided to the given peer.
1287         SendAcceptChannel {
1288                 /// The node_id of the node which should receive this message
1289                 node_id: PublicKey,
1290                 /// The message which should be sent.
1291                 msg: msgs::AcceptChannel,
1292         },
1293         /// Used to indicate that we've initiated a channel open and should send the open_channel
1294         /// message provided to the given peer.
1295         SendOpenChannel {
1296                 /// The node_id of the node which should receive this message
1297                 node_id: PublicKey,
1298                 /// The message which should be sent.
1299                 msg: msgs::OpenChannel,
1300         },
1301         /// Used to indicate that a funding_created message should be sent to the peer with the given node_id.
1302         SendFundingCreated {
1303                 /// The node_id of the node which should receive this message
1304                 node_id: PublicKey,
1305                 /// The message which should be sent.
1306                 msg: msgs::FundingCreated,
1307         },
1308         /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id.
1309         SendFundingSigned {
1310                 /// The node_id of the node which should receive this message
1311                 node_id: PublicKey,
1312                 /// The message which should be sent.
1313                 msg: msgs::FundingSigned,
1314         },
1315         /// Used to indicate that a channel_ready message should be sent to the peer with the given node_id.
1316         SendChannelReady {
1317                 /// The node_id of the node which should receive these message(s)
1318                 node_id: PublicKey,
1319                 /// The channel_ready message which should be sent.
1320                 msg: msgs::ChannelReady,
1321         },
1322         /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
1323         SendAnnouncementSignatures {
1324                 /// The node_id of the node which should receive these message(s)
1325                 node_id: PublicKey,
1326                 /// The announcement_signatures message which should be sent.
1327                 msg: msgs::AnnouncementSignatures,
1328         },
1329         /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed
1330         /// message should be sent to the peer with the given node_id.
1331         UpdateHTLCs {
1332                 /// The node_id of the node which should receive these message(s)
1333                 node_id: PublicKey,
1334                 /// The update messages which should be sent. ALL messages in the struct should be sent!
1335                 updates: msgs::CommitmentUpdate,
1336         },
1337         /// Used to indicate that a revoke_and_ack message should be sent to the peer with the given node_id.
1338         SendRevokeAndACK {
1339                 /// The node_id of the node which should receive this message
1340                 node_id: PublicKey,
1341                 /// The message which should be sent.
1342                 msg: msgs::RevokeAndACK,
1343         },
1344         /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id.
1345         SendClosingSigned {
1346                 /// The node_id of the node which should receive this message
1347                 node_id: PublicKey,
1348                 /// The message which should be sent.
1349                 msg: msgs::ClosingSigned,
1350         },
1351         /// Used to indicate that a shutdown message should be sent to the peer with the given node_id.
1352         SendShutdown {
1353                 /// The node_id of the node which should receive this message
1354                 node_id: PublicKey,
1355                 /// The message which should be sent.
1356                 msg: msgs::Shutdown,
1357         },
1358         /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id.
1359         SendChannelReestablish {
1360                 /// The node_id of the node which should receive this message
1361                 node_id: PublicKey,
1362                 /// The message which should be sent.
1363                 msg: msgs::ChannelReestablish,
1364         },
1365         /// Used to send a channel_announcement and channel_update to a specific peer, likely on
1366         /// initial connection to ensure our peers know about our channels.
1367         SendChannelAnnouncement {
1368                 /// The node_id of the node which should receive this message
1369                 node_id: PublicKey,
1370                 /// The channel_announcement which should be sent.
1371                 msg: msgs::ChannelAnnouncement,
1372                 /// The followup channel_update which should be sent.
1373                 update_msg: msgs::ChannelUpdate,
1374         },
1375         /// Used to indicate that a channel_announcement and channel_update should be broadcast to all
1376         /// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
1377         ///
1378         /// Note that after doing so, you very likely (unless you did so very recently) want to
1379         /// broadcast a node_announcement (e.g. via [`PeerManager::broadcast_node_announcement`]). This
1380         /// ensures that any nodes which see our channel_announcement also have a relevant
1381         /// node_announcement, including relevant feature flags which may be important for routing
1382         /// through or to us.
1383         ///
1384         /// [`PeerManager::broadcast_node_announcement`]: crate::ln::peer_handler::PeerManager::broadcast_node_announcement
1385         BroadcastChannelAnnouncement {
1386                 /// The channel_announcement which should be sent.
1387                 msg: msgs::ChannelAnnouncement,
1388                 /// The followup channel_update which should be sent.
1389                 update_msg: Option<msgs::ChannelUpdate>,
1390         },
1391         /// Used to indicate that a channel_update should be broadcast to all peers.
1392         BroadcastChannelUpdate {
1393                 /// The channel_update which should be sent.
1394                 msg: msgs::ChannelUpdate,
1395         },
1396         /// Used to indicate that a node_announcement should be broadcast to all peers.
1397         BroadcastNodeAnnouncement {
1398                 /// The node_announcement which should be sent.
1399                 msg: msgs::NodeAnnouncement,
1400         },
1401         /// Used to indicate that a channel_update should be sent to a single peer.
1402         /// In contrast to [`Self::BroadcastChannelUpdate`], this is used when the channel is a
1403         /// private channel and we shouldn't be informing all of our peers of channel parameters.
1404         SendChannelUpdate {
1405                 /// The node_id of the node which should receive this message
1406                 node_id: PublicKey,
1407                 /// The channel_update which should be sent.
1408                 msg: msgs::ChannelUpdate,
1409         },
1410         /// Broadcast an error downstream to be handled
1411         HandleError {
1412                 /// The node_id of the node which should receive this message
1413                 node_id: PublicKey,
1414                 /// The action which should be taken.
1415                 action: msgs::ErrorAction
1416         },
1417         /// Query a peer for channels with funding transaction UTXOs in a block range.
1418         SendChannelRangeQuery {
1419                 /// The node_id of this message recipient
1420                 node_id: PublicKey,
1421                 /// The query_channel_range which should be sent.
1422                 msg: msgs::QueryChannelRange,
1423         },
1424         /// Request routing gossip messages from a peer for a list of channels identified by
1425         /// their short_channel_ids.
1426         SendShortIdsQuery {
1427                 /// The node_id of this message recipient
1428                 node_id: PublicKey,
1429                 /// The query_short_channel_ids which should be sent.
1430                 msg: msgs::QueryShortChannelIds,
1431         },
1432         /// Sends a reply to a channel range query. This may be one of several SendReplyChannelRange events
1433         /// emitted during processing of the query.
1434         SendReplyChannelRange {
1435                 /// The node_id of this message recipient
1436                 node_id: PublicKey,
1437                 /// The reply_channel_range which should be sent.
1438                 msg: msgs::ReplyChannelRange,
1439         },
1440         /// Sends a timestamp filter for inbound gossip. This should be sent on each new connection to
1441         /// enable receiving gossip messages from the peer.
1442         SendGossipTimestampFilter {
1443                 /// The node_id of this message recipient
1444                 node_id: PublicKey,
1445                 /// The gossip_timestamp_filter which should be sent.
1446                 msg: msgs::GossipTimestampFilter,
1447         },
1448 }
1449
1450 /// A trait indicating an object may generate message send events
1451 pub trait MessageSendEventsProvider {
1452         /// Gets the list of pending events which were generated by previous actions, clearing the list
1453         /// in the process.
1454         fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
1455 }
1456
1457 /// A trait indicating an object may generate onion messages to send
1458 pub trait OnionMessageProvider {
1459         /// Gets the next pending onion message for the peer with the given node id.
1460         fn next_onion_message_for_peer(&self, peer_node_id: PublicKey) -> Option<msgs::OnionMessage>;
1461 }
1462
1463 /// A trait indicating an object may generate events.
1464 ///
1465 /// Events are processed by passing an [`EventHandler`] to [`process_pending_events`].
1466 ///
1467 /// Implementations of this trait may also feature an async version of event handling, as shown with
1468 /// [`ChannelManager::process_pending_events_async`] and
1469 /// [`ChainMonitor::process_pending_events_async`].
1470 ///
1471 /// # Requirements
1472 ///
1473 /// When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
1474 /// event since the last invocation.
1475 ///
1476 /// In order to ensure no [`Event`]s are lost, implementors of this trait will persist [`Event`]s
1477 /// and replay any unhandled events on startup. An [`Event`] is considered handled when
1478 /// [`process_pending_events`] returns, thus handlers MUST fully handle [`Event`]s and persist any
1479 /// relevant changes to disk *before* returning.
1480 ///
1481 /// Further, because an application may crash between an [`Event`] being handled and the
1482 /// implementor of this trait being re-serialized, [`Event`] handling must be idempotent - in
1483 /// effect, [`Event`]s may be replayed.
1484 ///
1485 /// Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
1486 /// consult the provider's documentation on the implication of processing events and how a handler
1487 /// may safely use the provider (e.g., see [`ChannelManager::process_pending_events`] and
1488 /// [`ChainMonitor::process_pending_events`]).
1489 ///
1490 /// (C-not implementable) As there is likely no reason for a user to implement this trait on their
1491 /// own type(s).
1492 ///
1493 /// [`process_pending_events`]: Self::process_pending_events
1494 /// [`handle_event`]: EventHandler::handle_event
1495 /// [`ChannelManager::process_pending_events`]: crate::ln::channelmanager::ChannelManager#method.process_pending_events
1496 /// [`ChainMonitor::process_pending_events`]: crate::chain::chainmonitor::ChainMonitor#method.process_pending_events
1497 /// [`ChannelManager::process_pending_events_async`]: crate::ln::channelmanager::ChannelManager::process_pending_events_async
1498 /// [`ChainMonitor::process_pending_events_async`]: crate::chain::chainmonitor::ChainMonitor::process_pending_events_async
1499 pub trait EventsProvider {
1500         /// Processes any events generated since the last call using the given event handler.
1501         ///
1502         /// See the trait-level documentation for requirements.
1503         fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler;
1504 }
1505
1506 /// A trait implemented for objects handling events from [`EventsProvider`].
1507 ///
1508 /// An async variation also exists for implementations of [`EventsProvider`] that support async
1509 /// event handling. The async event handler should satisfy the generic bounds: `F:
1510 /// core::future::Future, H: Fn(Event) -> F`.
1511 pub trait EventHandler {
1512         /// Handles the given [`Event`].
1513         ///
1514         /// See [`EventsProvider`] for details that must be considered when implementing this method.
1515         fn handle_event(&self, event: Event);
1516 }
1517
1518 impl<F> EventHandler for F where F: Fn(Event) {
1519         fn handle_event(&self, event: Event) {
1520                 self(event)
1521         }
1522 }
1523
1524 impl<T: EventHandler> EventHandler for Arc<T> {
1525         fn handle_event(&self, event: Event) {
1526                 self.deref().handle_event(event)
1527         }
1528 }