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Merge pull request #1429 from TheBlueMatt/2022-04-drop-no-conn-possible
[rust-lightning] / lightning / src / util / events.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 use chain::keysinterface::SpendableOutputDescriptor;
18 use ln::channelmanager::PaymentId;
19 use ln::channel::FUNDING_CONF_DEADLINE_BLOCKS;
20 use ln::features::ChannelTypeFeatures;
21 use ln::msgs;
22 use ln::msgs::DecodeError;
23 use ln::{PaymentPreimage, PaymentHash, PaymentSecret};
24 use routing::network_graph::NetworkUpdate;
25 use util::ser::{BigSize, FixedLengthReader, Writeable, Writer, MaybeReadable, Readable, VecReadWrapper, VecWriteWrapper};
26 use routing::router::{RouteHop, RouteParameters};
27
28 use bitcoin::Transaction;
29 use bitcoin::blockdata::script::Script;
30 use bitcoin::hashes::Hash;
31 use bitcoin::hashes::sha256::Hash as Sha256;
32 use bitcoin::secp256k1::PublicKey;
33 use io;
34 use prelude::*;
35 use core::time::Duration;
36 use core::ops::Deref;
37 use sync::Arc;
38
39 /// Some information provided on receipt of payment depends on whether the payment received is a
40 /// spontaneous payment or a "conventional" lightning payment that's paying an invoice.
41 #[derive(Clone, Debug)]
42 pub enum PaymentPurpose {
43         /// Information for receiving a payment that we generated an invoice for.
44         InvoicePayment {
45                 /// The preimage to the payment_hash, if the payment hash (and secret) were fetched via
46                 /// [`ChannelManager::create_inbound_payment`]. If provided, this can be handed directly to
47                 /// [`ChannelManager::claim_funds`].
48                 ///
49                 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
50                 /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
51                 payment_preimage: Option<PaymentPreimage>,
52                 /// The "payment secret". This authenticates the sender to the recipient, preventing a
53                 /// number of deanonymization attacks during the routing process.
54                 /// It is provided here for your reference, however its accuracy is enforced directly by
55                 /// [`ChannelManager`] using the values you previously provided to
56                 /// [`ChannelManager::create_inbound_payment`] or
57                 /// [`ChannelManager::create_inbound_payment_for_hash`].
58                 ///
59                 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
60                 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
61                 /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
62                 payment_secret: PaymentSecret,
63         },
64         /// Because this is a spontaneous payment, the payer generated their own preimage rather than us
65         /// (the payee) providing a preimage.
66         SpontaneousPayment(PaymentPreimage),
67 }
68
69 #[derive(Clone, Debug, PartialEq)]
70 /// The reason the channel was closed. See individual variants more details.
71 pub enum ClosureReason {
72         /// Closure generated from receiving a peer error message.
73         ///
74         /// Our counterparty may have broadcasted their latest commitment state, and we have
75         /// as well.
76         CounterpartyForceClosed {
77                 /// The error which the peer sent us.
78                 ///
79                 /// The string should be sanitized before it is used (e.g emitted to logs
80                 /// or printed to stdout). Otherwise, a well crafted error message may exploit
81                 /// a security vulnerability in the terminal emulator or the logging subsystem.
82                 peer_msg: String,
83         },
84         /// Closure generated from [`ChannelManager::force_close_channel`], called by the user.
85         ///
86         /// [`ChannelManager::force_close_channel`]: crate::ln::channelmanager::ChannelManager::force_close_channel.
87         HolderForceClosed,
88         /// The channel was closed after negotiating a cooperative close and we've now broadcasted
89         /// the cooperative close transaction. Note the shutdown may have been initiated by us.
90         //TODO: split between CounterpartyInitiated/LocallyInitiated
91         CooperativeClosure,
92         /// A commitment transaction was confirmed on chain, closing the channel. Most likely this
93         /// commitment transaction came from our counterparty, but it may also have come from
94         /// a copy of our own `ChannelMonitor`.
95         CommitmentTxConfirmed,
96         /// The funding transaction failed to confirm in a timely manner on an inbound channel.
97         FundingTimedOut,
98         /// Closure generated from processing an event, likely a HTLC forward/relay/reception.
99         ProcessingError {
100                 /// A developer-readable error message which we generated.
101                 err: String,
102         },
103         /// The peer disconnected prior to funding completing. In this case the spec mandates that we
104         /// forget the channel entirely - we can attempt again if the peer reconnects.
105         ///
106         /// In LDK versions prior to 0.0.107 this could also occur if we were unable to connect to the
107         /// peer because of mutual incompatibility between us and our channel counterparty.
108         DisconnectedPeer,
109         /// Closure generated from `ChannelManager::read` if the ChannelMonitor is newer than
110         /// the ChannelManager deserialized.
111         OutdatedChannelManager
112 }
113
114 impl core::fmt::Display for ClosureReason {
115         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
116                 f.write_str("Channel closed because ")?;
117                 match self {
118                         ClosureReason::CounterpartyForceClosed { peer_msg } => {
119                                 f.write_str("counterparty force-closed with message ")?;
120                                 f.write_str(&peer_msg)
121                         },
122                         ClosureReason::HolderForceClosed => f.write_str("user manually force-closed the channel"),
123                         ClosureReason::CooperativeClosure => f.write_str("the channel was cooperatively closed"),
124                         ClosureReason::CommitmentTxConfirmed => f.write_str("commitment or closing transaction was confirmed on chain."),
125                         ClosureReason::FundingTimedOut => write!(f, "funding transaction failed to confirm within {} blocks", FUNDING_CONF_DEADLINE_BLOCKS),
126                         ClosureReason::ProcessingError { err } => {
127                                 f.write_str("of an exception: ")?;
128                                 f.write_str(&err)
129                         },
130                         ClosureReason::DisconnectedPeer => f.write_str("the peer disconnected prior to the channel being funded"),
131                         ClosureReason::OutdatedChannelManager => f.write_str("the ChannelManager read from disk was stale compared to ChannelMonitor(s)"),
132                 }
133         }
134 }
135
136 impl_writeable_tlv_based_enum_upgradable!(ClosureReason,
137         (0, CounterpartyForceClosed) => { (1, peer_msg, required) },
138         (1, FundingTimedOut) => {},
139         (2, HolderForceClosed) => {},
140         (6, CommitmentTxConfirmed) => {},
141         (4, CooperativeClosure) => {},
142         (8, ProcessingError) => { (1, err, required) },
143         (10, DisconnectedPeer) => {},
144         (12, OutdatedChannelManager) => {},
145 );
146
147 /// An Event which you should probably take some action in response to.
148 ///
149 /// Note that while Writeable and Readable are implemented for Event, you probably shouldn't use
150 /// them directly as they don't round-trip exactly (for example FundingGenerationReady is never
151 /// written as it makes no sense to respond to it after reconnecting to peers).
152 #[derive(Clone, Debug)]
153 pub enum Event {
154         /// Used to indicate that the client should generate a funding transaction with the given
155         /// parameters and then call [`ChannelManager::funding_transaction_generated`].
156         /// Generated in [`ChannelManager`] message handling.
157         /// Note that *all inputs* in the funding transaction must spend SegWit outputs or your
158         /// counterparty can steal your funds!
159         ///
160         /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
161         /// [`ChannelManager::funding_transaction_generated`]: crate::ln::channelmanager::ChannelManager::funding_transaction_generated
162         FundingGenerationReady {
163                 /// The random channel_id we picked which you'll need to pass into
164                 /// ChannelManager::funding_transaction_generated.
165                 temporary_channel_id: [u8; 32],
166                 /// The value, in satoshis, that the output should have.
167                 channel_value_satoshis: u64,
168                 /// The script which should be used in the transaction output.
169                 output_script: Script,
170                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`], or 0 for
171                 /// an inbound channel.
172                 ///
173                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
174                 user_channel_id: u64,
175         },
176         /// Indicates we've received money! Just gotta dig out that payment preimage and feed it to
177         /// [`ChannelManager::claim_funds`] to get it....
178         /// Note that if the preimage is not known, you should call
179         /// [`ChannelManager::fail_htlc_backwards`] to free up resources for this HTLC and avoid
180         /// network congestion.
181         /// If you fail to call either [`ChannelManager::claim_funds`] or
182         /// [`ChannelManager::fail_htlc_backwards`] within the HTLC's timeout, the HTLC will be
183         /// automatically failed.
184         ///
185         /// # Note
186         /// LDK will not stop an inbound payment from being paid multiple times, so multiple
187         /// `PaymentReceived` events may be generated for the same payment.
188         ///
189         /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
190         /// [`ChannelManager::fail_htlc_backwards`]: crate::ln::channelmanager::ChannelManager::fail_htlc_backwards
191         PaymentReceived {
192                 /// The hash for which the preimage should be handed to the ChannelManager. Note that LDK will
193                 /// not stop you from registering duplicate payment hashes for inbound payments.
194                 payment_hash: PaymentHash,
195                 /// The value, in thousandths of a satoshi, that this payment is for.
196                 amt: u64,
197                 /// Information for claiming this received payment, based on whether the purpose of the
198                 /// payment is to pay an invoice or to send a spontaneous payment.
199                 purpose: PaymentPurpose,
200         },
201         /// Indicates an outbound payment we made succeeded (i.e. it made it all the way to its target
202         /// and we got back the payment preimage for it).
203         ///
204         /// Note for MPP payments: in rare cases, this event may be preceded by a `PaymentPathFailed`
205         /// event. In this situation, you SHOULD treat this payment as having succeeded.
206         PaymentSent {
207                 /// The id returned by [`ChannelManager::send_payment`] and used with
208                 /// [`ChannelManager::retry_payment`].
209                 ///
210                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
211                 /// [`ChannelManager::retry_payment`]: crate::ln::channelmanager::ChannelManager::retry_payment
212                 payment_id: Option<PaymentId>,
213                 /// The preimage to the hash given to ChannelManager::send_payment.
214                 /// Note that this serves as a payment receipt, if you wish to have such a thing, you must
215                 /// store it somehow!
216                 payment_preimage: PaymentPreimage,
217                 /// The hash that was given to [`ChannelManager::send_payment`].
218                 ///
219                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
220                 payment_hash: PaymentHash,
221                 /// The total fee which was spent at intermediate hops in this payment, across all paths.
222                 ///
223                 /// Note that, like [`Route::get_total_fees`] this does *not* include any potential
224                 /// overpayment to the recipient node.
225                 ///
226                 /// If the recipient or an intermediate node misbehaves and gives us free money, this may
227                 /// overstate the amount paid, though this is unlikely.
228                 ///
229                 /// [`Route::get_total_fees`]: crate::routing::router::Route::get_total_fees
230                 fee_paid_msat: Option<u64>,
231         },
232         /// Indicates an outbound payment failed. Individual [`Event::PaymentPathFailed`] events
233         /// provide failure information for each MPP part in the payment.
234         ///
235         /// This event is provided once there are no further pending HTLCs for the payment and the
236         /// payment is no longer retryable, either due to a several-block timeout or because
237         /// [`ChannelManager::abandon_payment`] was previously called for the corresponding payment.
238         ///
239         /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
240         PaymentFailed {
241                 /// The id returned by [`ChannelManager::send_payment`] and used with
242                 /// [`ChannelManager::retry_payment`] and [`ChannelManager::abandon_payment`].
243                 ///
244                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
245                 /// [`ChannelManager::retry_payment`]: crate::ln::channelmanager::ChannelManager::retry_payment
246                 /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
247                 payment_id: PaymentId,
248                 /// The hash that was given to [`ChannelManager::send_payment`].
249                 ///
250                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
251                 payment_hash: PaymentHash,
252         },
253         /// Indicates that a path for an outbound payment was successful.
254         ///
255         /// Always generated after [`Event::PaymentSent`] and thus useful for scoring channels. See
256         /// [`Event::PaymentSent`] for obtaining the payment preimage.
257         PaymentPathSuccessful {
258                 /// The id returned by [`ChannelManager::send_payment`] and used with
259                 /// [`ChannelManager::retry_payment`].
260                 ///
261                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
262                 /// [`ChannelManager::retry_payment`]: crate::ln::channelmanager::ChannelManager::retry_payment
263                 payment_id: PaymentId,
264                 /// The hash that was given to [`ChannelManager::send_payment`].
265                 ///
266                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
267                 payment_hash: Option<PaymentHash>,
268                 /// The payment path that was successful.
269                 ///
270                 /// May contain a closed channel if the HTLC sent along the path was fulfilled on chain.
271                 path: Vec<RouteHop>,
272         },
273         /// Indicates an outbound HTLC we sent failed. Probably some intermediary node dropped
274         /// something. You may wish to retry with a different route.
275         ///
276         /// Note that this does *not* indicate that all paths for an MPP payment have failed, see
277         /// [`Event::PaymentFailed`] and [`all_paths_failed`].
278         ///
279         /// [`all_paths_failed`]: Self::PaymentPathFailed::all_paths_failed
280         PaymentPathFailed {
281                 /// The id returned by [`ChannelManager::send_payment`] and used with
282                 /// [`ChannelManager::retry_payment`] and [`ChannelManager::abandon_payment`].
283                 ///
284                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
285                 /// [`ChannelManager::retry_payment`]: crate::ln::channelmanager::ChannelManager::retry_payment
286                 /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
287                 payment_id: Option<PaymentId>,
288                 /// The hash that was given to [`ChannelManager::send_payment`].
289                 ///
290                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
291                 payment_hash: PaymentHash,
292                 /// Indicates the payment was rejected for some reason by the recipient. This implies that
293                 /// the payment has failed, not just the route in question. If this is not set, you may
294                 /// retry the payment via a different route.
295                 rejected_by_dest: bool,
296                 /// Any failure information conveyed via the Onion return packet by a node along the failed
297                 /// payment route.
298                 ///
299                 /// Should be applied to the [`NetworkGraph`] so that routing decisions can take into
300                 /// account the update. [`NetGraphMsgHandler`] is capable of doing this.
301                 ///
302                 /// [`NetworkGraph`]: crate::routing::network_graph::NetworkGraph
303                 /// [`NetGraphMsgHandler`]: crate::routing::network_graph::NetGraphMsgHandler
304                 network_update: Option<NetworkUpdate>,
305                 /// For both single-path and multi-path payments, this is set if all paths of the payment have
306                 /// failed. This will be set to false if (1) this is an MPP payment and (2) other parts of the
307                 /// larger MPP payment were still in flight when this event was generated.
308                 ///
309                 /// Note that if you are retrying individual MPP parts, using this value to determine if a
310                 /// payment has fully failed is race-y. Because multiple failures can happen prior to events
311                 /// being processed, you may retry in response to a first failure, with a second failure
312                 /// (with `all_paths_failed` set) still pending. Then, when the second failure is processed
313                 /// you will see `all_paths_failed` set even though the retry of the first failure still
314                 /// has an associated in-flight HTLC. See (1) for an example of such a failure.
315                 ///
316                 /// If you wish to retry individual MPP parts and learn when a payment has failed, you must
317                 /// call [`ChannelManager::abandon_payment`] and wait for a [`Event::PaymentFailed`] event.
318                 ///
319                 /// (1) <https://github.com/lightningdevkit/rust-lightning/issues/1164>
320                 ///
321                 /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
322                 all_paths_failed: bool,
323                 /// The payment path that failed.
324                 path: Vec<RouteHop>,
325                 /// The channel responsible for the failed payment path.
326                 ///
327                 /// If this is `Some`, then the corresponding channel should be avoided when the payment is
328                 /// retried. May be `None` for older [`Event`] serializations.
329                 short_channel_id: Option<u64>,
330                 /// Parameters needed to compute a new [`Route`] when retrying the failed payment path.
331                 ///
332                 /// See [`find_route`] for details.
333                 ///
334                 /// [`Route`]: crate::routing::router::Route
335                 /// [`find_route`]: crate::routing::router::find_route
336                 retry: Option<RouteParameters>,
337 #[cfg(test)]
338                 error_code: Option<u16>,
339 #[cfg(test)]
340                 error_data: Option<Vec<u8>>,
341         },
342         /// Used to indicate that [`ChannelManager::process_pending_htlc_forwards`] should be called at
343         /// a time in the future.
344         ///
345         /// [`ChannelManager::process_pending_htlc_forwards`]: crate::ln::channelmanager::ChannelManager::process_pending_htlc_forwards
346         PendingHTLCsForwardable {
347                 /// The minimum amount of time that should be waited prior to calling
348                 /// process_pending_htlc_forwards. To increase the effort required to correlate payments,
349                 /// you should wait a random amount of time in roughly the range (now + time_forwardable,
350                 /// now + 5*time_forwardable).
351                 time_forwardable: Duration,
352         },
353         /// Used to indicate that an output which you should know how to spend was confirmed on chain
354         /// and is now spendable.
355         /// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
356         /// counterparty spending them due to some kind of timeout. Thus, you need to store them
357         /// somewhere and spend them when you create on-chain transactions.
358         SpendableOutputs {
359                 /// The outputs which you should store as spendable by you.
360                 outputs: Vec<SpendableOutputDescriptor>,
361         },
362         /// This event is generated when a payment has been successfully forwarded through us and a
363         /// forwarding fee earned.
364         PaymentForwarded {
365                 /// The channel between the source node and us. Optional because versions prior to 0.0.107
366                 /// do not serialize this field.
367                 source_channel_id: Option<[u8; 32]>,
368                 /// The fee, in milli-satoshis, which was earned as a result of the payment.
369                 ///
370                 /// Note that if we force-closed the channel over which we forwarded an HTLC while the HTLC
371                 /// was pending, the amount the next hop claimed will have been rounded down to the nearest
372                 /// whole satoshi. Thus, the fee calculated here may be higher than expected as we still
373                 /// claimed the full value in millisatoshis from the source. In this case,
374                 /// `claim_from_onchain_tx` will be set.
375                 ///
376                 /// If the channel which sent us the payment has been force-closed, we will claim the funds
377                 /// via an on-chain transaction. In that case we do not yet know the on-chain transaction
378                 /// fees which we will spend and will instead set this to `None`. It is possible duplicate
379                 /// `PaymentForwarded` events are generated for the same payment iff `fee_earned_msat` is
380                 /// `None`.
381                 fee_earned_msat: Option<u64>,
382                 /// If this is `true`, the forwarded HTLC was claimed by our counterparty via an on-chain
383                 /// transaction.
384                 claim_from_onchain_tx: bool,
385         },
386         /// Used to indicate that a channel with the given `channel_id` is in the process of closure.
387         ChannelClosed  {
388                 /// The channel_id of the channel which has been closed. Note that on-chain transactions
389                 /// resolving the channel are likely still awaiting confirmation.
390                 channel_id: [u8; 32],
391                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
392                 /// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
393                 /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
394                 /// `user_channel_id` will be 0 for an inbound channel.
395                 /// This will always be zero for objects serialized with LDK versions prior to 0.0.102.
396                 ///
397                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
398                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
399                 /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
400                 user_channel_id: u64,
401                 /// The reason the channel was closed.
402                 reason: ClosureReason
403         },
404         /// Used to indicate to the user that they can abandon the funding transaction and recycle the
405         /// inputs for another purpose.
406         DiscardFunding {
407                 /// The channel_id of the channel which has been closed.
408                 channel_id: [u8; 32],
409                 /// The full transaction received from the user
410                 transaction: Transaction
411         },
412         /// Indicates a request to open a new channel by a peer.
413         ///
414         /// To accept the request, call [`ChannelManager::accept_inbound_channel`]. To reject the
415         /// request, call [`ChannelManager::force_close_channel`].
416         ///
417         /// The event is only triggered when a new open channel request is received and the
418         /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true.
419         ///
420         /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
421         /// [`ChannelManager::force_close_channel`]: crate::ln::channelmanager::ChannelManager::force_close_channel
422         /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
423         OpenChannelRequest {
424                 /// The temporary channel ID of the channel requested to be opened.
425                 ///
426                 /// When responding to the request, the `temporary_channel_id` should be passed
427                 /// back to the ChannelManager with [`ChannelManager::accept_inbound_channel`] to accept,
428                 /// or to [`ChannelManager::force_close_channel`] to reject.
429                 ///
430                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
431                 /// [`ChannelManager::force_close_channel`]: crate::ln::channelmanager::ChannelManager::force_close_channel
432                 temporary_channel_id: [u8; 32],
433                 /// The node_id of the counterparty requesting to open the channel.
434                 counterparty_node_id: PublicKey,
435                 /// The channel value of the requested channel.
436                 funding_satoshis: u64,
437                 /// Our starting balance in the channel if the request is accepted, in milli-satoshi.
438                 push_msat: u64,
439                 /// The features that this channel will operate with. If you reject the channel, a
440                 /// well-behaved counterparty may automatically re-attempt the channel with a new set of
441                 /// feature flags.
442                 ///
443                 /// Note that if [`ChannelTypeFeatures::supports_scid_privacy`] returns true on this type,
444                 /// the resulting [`ChannelManager`] will not be readable by versions of LDK prior to
445                 /// 0.0.106.
446                 ///
447                 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
448                 channel_type: ChannelTypeFeatures,
449         },
450 }
451
452 impl Writeable for Event {
453         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
454                 match self {
455                         &Event::FundingGenerationReady { .. } => {
456                                 0u8.write(writer)?;
457                                 // We never write out FundingGenerationReady events as, upon disconnection, peers
458                                 // drop any channels which have not yet exchanged funding_signed.
459                         },
460                         &Event::PaymentReceived { ref payment_hash, ref amt, ref purpose } => {
461                                 1u8.write(writer)?;
462                                 let mut payment_secret = None;
463                                 let payment_preimage;
464                                 match &purpose {
465                                         PaymentPurpose::InvoicePayment { payment_preimage: preimage, payment_secret: secret } => {
466                                                 payment_secret = Some(secret);
467                                                 payment_preimage = *preimage;
468                                         },
469                                         PaymentPurpose::SpontaneousPayment(preimage) => {
470                                                 payment_preimage = Some(*preimage);
471                                         }
472                                 }
473                                 write_tlv_fields!(writer, {
474                                         (0, payment_hash, required),
475                                         (2, payment_secret, option),
476                                         (4, amt, required),
477                                         (6, 0u64, required), // user_payment_id required for compatibility with 0.0.103 and earlier
478                                         (8, payment_preimage, option),
479                                 });
480                         },
481                         &Event::PaymentSent { ref payment_id, ref payment_preimage, ref payment_hash, ref fee_paid_msat } => {
482                                 2u8.write(writer)?;
483                                 write_tlv_fields!(writer, {
484                                         (0, payment_preimage, required),
485                                         (1, payment_hash, required),
486                                         (3, payment_id, option),
487                                         (5, fee_paid_msat, option),
488                                 });
489                         },
490                         &Event::PaymentPathFailed {
491                                 ref payment_id, ref payment_hash, ref rejected_by_dest, ref network_update,
492                                 ref all_paths_failed, ref path, ref short_channel_id, ref retry,
493                                 #[cfg(test)]
494                                 ref error_code,
495                                 #[cfg(test)]
496                                 ref error_data,
497                         } => {
498                                 3u8.write(writer)?;
499                                 #[cfg(test)]
500                                 error_code.write(writer)?;
501                                 #[cfg(test)]
502                                 error_data.write(writer)?;
503                                 write_tlv_fields!(writer, {
504                                         (0, payment_hash, required),
505                                         (1, network_update, option),
506                                         (2, rejected_by_dest, required),
507                                         (3, all_paths_failed, required),
508                                         (5, path, vec_type),
509                                         (7, short_channel_id, option),
510                                         (9, retry, option),
511                                         (11, payment_id, option),
512                                 });
513                         },
514                         &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
515                                 4u8.write(writer)?;
516                                 // Note that we now ignore these on the read end as we'll re-generate them in
517                                 // ChannelManager, we write them here only for backwards compatibility.
518                         },
519                         &Event::SpendableOutputs { ref outputs } => {
520                                 5u8.write(writer)?;
521                                 write_tlv_fields!(writer, {
522                                         (0, VecWriteWrapper(outputs), required),
523                                 });
524                         },
525                         &Event::PaymentForwarded { fee_earned_msat, source_channel_id, claim_from_onchain_tx } => {
526                                 7u8.write(writer)?;
527                                 write_tlv_fields!(writer, {
528                                         (0, fee_earned_msat, option),
529                                         (1, source_channel_id, option),
530                                         (2, claim_from_onchain_tx, required),
531                                 });
532                         },
533                         &Event::ChannelClosed { ref channel_id, ref user_channel_id, ref reason } => {
534                                 9u8.write(writer)?;
535                                 write_tlv_fields!(writer, {
536                                         (0, channel_id, required),
537                                         (1, user_channel_id, required),
538                                         (2, reason, required)
539                                 });
540                         },
541                         &Event::DiscardFunding { ref channel_id, ref transaction } => {
542                                 11u8.write(writer)?;
543                                 write_tlv_fields!(writer, {
544                                         (0, channel_id, required),
545                                         (2, transaction, required)
546                                 })
547                         },
548                         &Event::PaymentPathSuccessful { ref payment_id, ref payment_hash, ref path } => {
549                                 13u8.write(writer)?;
550                                 write_tlv_fields!(writer, {
551                                         (0, payment_id, required),
552                                         (2, payment_hash, option),
553                                         (4, path, vec_type)
554                                 })
555                         },
556                         &Event::PaymentFailed { ref payment_id, ref payment_hash } => {
557                                 15u8.write(writer)?;
558                                 write_tlv_fields!(writer, {
559                                         (0, payment_id, required),
560                                         (2, payment_hash, required),
561                                 })
562                         },
563                         &Event::OpenChannelRequest { .. } => {
564                                 17u8.write(writer)?;
565                                 // We never write the OpenChannelRequest events as, upon disconnection, peers
566                                 // drop any channels which have not yet exchanged funding_signed.
567                         },
568                         // Note that, going forward, all new events must only write data inside of
569                         // `write_tlv_fields`. Versions 0.0.101+ will ignore odd-numbered events that write
570                         // data via `write_tlv_fields`.
571                 }
572                 Ok(())
573         }
574 }
575 impl MaybeReadable for Event {
576         fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
577                 match Readable::read(reader)? {
578                         // Note that we do not write a length-prefixed TLV for FundingGenerationReady events,
579                         // unlike all other events, thus we return immediately here.
580                         0u8 => Ok(None),
581                         1u8 => {
582                                 let f = || {
583                                         let mut payment_hash = PaymentHash([0; 32]);
584                                         let mut payment_preimage = None;
585                                         let mut payment_secret = None;
586                                         let mut amt = 0;
587                                         let mut _user_payment_id = None::<u64>; // For compatibility with 0.0.103 and earlier
588                                         read_tlv_fields!(reader, {
589                                                 (0, payment_hash, required),
590                                                 (2, payment_secret, option),
591                                                 (4, amt, required),
592                                                 (6, _user_payment_id, option),
593                                                 (8, payment_preimage, option),
594                                         });
595                                         let purpose = match payment_secret {
596                                                 Some(secret) => PaymentPurpose::InvoicePayment {
597                                                         payment_preimage,
598                                                         payment_secret: secret
599                                                 },
600                                                 None if payment_preimage.is_some() => PaymentPurpose::SpontaneousPayment(payment_preimage.unwrap()),
601                                                 None => return Err(msgs::DecodeError::InvalidValue),
602                                         };
603                                         Ok(Some(Event::PaymentReceived {
604                                                 payment_hash,
605                                                 amt,
606                                                 purpose,
607                                         }))
608                                 };
609                                 f()
610                         },
611                         2u8 => {
612                                 let f = || {
613                                         let mut payment_preimage = PaymentPreimage([0; 32]);
614                                         let mut payment_hash = None;
615                                         let mut payment_id = None;
616                                         let mut fee_paid_msat = None;
617                                         read_tlv_fields!(reader, {
618                                                 (0, payment_preimage, required),
619                                                 (1, payment_hash, option),
620                                                 (3, payment_id, option),
621                                                 (5, fee_paid_msat, option),
622                                         });
623                                         if payment_hash.is_none() {
624                                                 payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()));
625                                         }
626                                         Ok(Some(Event::PaymentSent {
627                                                 payment_id,
628                                                 payment_preimage,
629                                                 payment_hash: payment_hash.unwrap(),
630                                                 fee_paid_msat,
631                                         }))
632                                 };
633                                 f()
634                         },
635                         3u8 => {
636                                 let f = || {
637                                         #[cfg(test)]
638                                         let error_code = Readable::read(reader)?;
639                                         #[cfg(test)]
640                                         let error_data = Readable::read(reader)?;
641                                         let mut payment_hash = PaymentHash([0; 32]);
642                                         let mut rejected_by_dest = false;
643                                         let mut network_update = None;
644                                         let mut all_paths_failed = Some(true);
645                                         let mut path: Option<Vec<RouteHop>> = Some(vec![]);
646                                         let mut short_channel_id = None;
647                                         let mut retry = None;
648                                         let mut payment_id = None;
649                                         read_tlv_fields!(reader, {
650                                                 (0, payment_hash, required),
651                                                 (1, network_update, ignorable),
652                                                 (2, rejected_by_dest, required),
653                                                 (3, all_paths_failed, option),
654                                                 (5, path, vec_type),
655                                                 (7, short_channel_id, option),
656                                                 (9, retry, option),
657                                                 (11, payment_id, option),
658                                         });
659                                         Ok(Some(Event::PaymentPathFailed {
660                                                 payment_id,
661                                                 payment_hash,
662                                                 rejected_by_dest,
663                                                 network_update,
664                                                 all_paths_failed: all_paths_failed.unwrap(),
665                                                 path: path.unwrap(),
666                                                 short_channel_id,
667                                                 retry,
668                                                 #[cfg(test)]
669                                                 error_code,
670                                                 #[cfg(test)]
671                                                 error_data,
672                                         }))
673                                 };
674                                 f()
675                         },
676                         4u8 => Ok(None),
677                         5u8 => {
678                                 let f = || {
679                                         let mut outputs = VecReadWrapper(Vec::new());
680                                         read_tlv_fields!(reader, {
681                                                 (0, outputs, required),
682                                         });
683                                         Ok(Some(Event::SpendableOutputs { outputs: outputs.0 }))
684                                 };
685                                 f()
686                         },
687                         7u8 => {
688                                 let f = || {
689                                         let mut fee_earned_msat = None;
690                                         let mut source_channel_id = None;
691                                         let mut claim_from_onchain_tx = false;
692                                         read_tlv_fields!(reader, {
693                                                 (0, fee_earned_msat, option),
694                                                 (1, source_channel_id, option),
695                                                 (2, claim_from_onchain_tx, required),
696                                         });
697                                         Ok(Some(Event::PaymentForwarded { fee_earned_msat, source_channel_id, claim_from_onchain_tx }))
698                                 };
699                                 f()
700                         },
701                         9u8 => {
702                                 let f = || {
703                                         let mut channel_id = [0; 32];
704                                         let mut reason = None;
705                                         let mut user_channel_id_opt = None;
706                                         read_tlv_fields!(reader, {
707                                                 (0, channel_id, required),
708                                                 (1, user_channel_id_opt, option),
709                                                 (2, reason, ignorable),
710                                         });
711                                         if reason.is_none() { return Ok(None); }
712                                         let user_channel_id = if let Some(id) = user_channel_id_opt { id } else { 0 };
713                                         Ok(Some(Event::ChannelClosed { channel_id, user_channel_id, reason: reason.unwrap() }))
714                                 };
715                                 f()
716                         },
717                         11u8 => {
718                                 let f = || {
719                                         let mut channel_id = [0; 32];
720                                         let mut transaction = Transaction{ version: 2, lock_time: 0, input: Vec::new(), output: Vec::new() };
721                                         read_tlv_fields!(reader, {
722                                                 (0, channel_id, required),
723                                                 (2, transaction, required),
724                                         });
725                                         Ok(Some(Event::DiscardFunding { channel_id, transaction } ))
726                                 };
727                                 f()
728                         },
729                         13u8 => {
730                                 let f = || {
731                                         let mut payment_id = PaymentId([0; 32]);
732                                         let mut payment_hash = None;
733                                         let mut path: Option<Vec<RouteHop>> = Some(vec![]);
734                                         read_tlv_fields!(reader, {
735                                                 (0, payment_id, required),
736                                                 (2, payment_hash, option),
737                                                 (4, path, vec_type),
738                                         });
739                                         Ok(Some(Event::PaymentPathSuccessful {
740                                                 payment_id,
741                                                 payment_hash,
742                                                 path: path.unwrap(),
743                                         }))
744                                 };
745                                 f()
746                         },
747                         15u8 => {
748                                 let f = || {
749                                         let mut payment_hash = PaymentHash([0; 32]);
750                                         let mut payment_id = PaymentId([0; 32]);
751                                         read_tlv_fields!(reader, {
752                                                 (0, payment_id, required),
753                                                 (2, payment_hash, required),
754                                         });
755                                         Ok(Some(Event::PaymentFailed {
756                                                 payment_id,
757                                                 payment_hash,
758                                         }))
759                                 };
760                                 f()
761                         },
762                         17u8 => {
763                                 // Value 17 is used for `Event::OpenChannelRequest`.
764                                 Ok(None)
765                         },
766                         // Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue.
767                         // Version 0.0.100 failed to properly ignore odd types, possibly resulting in corrupt
768                         // reads.
769                         x if x % 2 == 1 => {
770                                 // If the event is of unknown type, assume it was written with `write_tlv_fields`,
771                                 // which prefixes the whole thing with a length BigSize. Because the event is
772                                 // odd-type unknown, we should treat it as `Ok(None)` even if it has some TLV
773                                 // fields that are even. Thus, we avoid using `read_tlv_fields` and simply read
774                                 // exactly the number of bytes specified, ignoring them entirely.
775                                 let tlv_len: BigSize = Readable::read(reader)?;
776                                 FixedLengthReader::new(reader, tlv_len.0)
777                                         .eat_remaining().map_err(|_| msgs::DecodeError::ShortRead)?;
778                                 Ok(None)
779                         },
780                         _ => Err(msgs::DecodeError::InvalidValue)
781                 }
782         }
783 }
784
785 /// An event generated by ChannelManager which indicates a message should be sent to a peer (or
786 /// broadcast to most peers).
787 /// These events are handled by PeerManager::process_events if you are using a PeerManager.
788 #[derive(Clone, Debug)]
789 pub enum MessageSendEvent {
790         /// Used to indicate that we've accepted a channel open and should send the accept_channel
791         /// message provided to the given peer.
792         SendAcceptChannel {
793                 /// The node_id of the node which should receive this message
794                 node_id: PublicKey,
795                 /// The message which should be sent.
796                 msg: msgs::AcceptChannel,
797         },
798         /// Used to indicate that we've initiated a channel open and should send the open_channel
799         /// message provided to the given peer.
800         SendOpenChannel {
801                 /// The node_id of the node which should receive this message
802                 node_id: PublicKey,
803                 /// The message which should be sent.
804                 msg: msgs::OpenChannel,
805         },
806         /// Used to indicate that a funding_created message should be sent to the peer with the given node_id.
807         SendFundingCreated {
808                 /// The node_id of the node which should receive this message
809                 node_id: PublicKey,
810                 /// The message which should be sent.
811                 msg: msgs::FundingCreated,
812         },
813         /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id.
814         SendFundingSigned {
815                 /// The node_id of the node which should receive this message
816                 node_id: PublicKey,
817                 /// The message which should be sent.
818                 msg: msgs::FundingSigned,
819         },
820         /// Used to indicate that a funding_locked message should be sent to the peer with the given node_id.
821         SendFundingLocked {
822                 /// The node_id of the node which should receive these message(s)
823                 node_id: PublicKey,
824                 /// The funding_locked message which should be sent.
825                 msg: msgs::FundingLocked,
826         },
827         /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
828         SendAnnouncementSignatures {
829                 /// The node_id of the node which should receive these message(s)
830                 node_id: PublicKey,
831                 /// The announcement_signatures message which should be sent.
832                 msg: msgs::AnnouncementSignatures,
833         },
834         /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed
835         /// message should be sent to the peer with the given node_id.
836         UpdateHTLCs {
837                 /// The node_id of the node which should receive these message(s)
838                 node_id: PublicKey,
839                 /// The update messages which should be sent. ALL messages in the struct should be sent!
840                 updates: msgs::CommitmentUpdate,
841         },
842         /// Used to indicate that a revoke_and_ack message should be sent to the peer with the given node_id.
843         SendRevokeAndACK {
844                 /// The node_id of the node which should receive this message
845                 node_id: PublicKey,
846                 /// The message which should be sent.
847                 msg: msgs::RevokeAndACK,
848         },
849         /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id.
850         SendClosingSigned {
851                 /// The node_id of the node which should receive this message
852                 node_id: PublicKey,
853                 /// The message which should be sent.
854                 msg: msgs::ClosingSigned,
855         },
856         /// Used to indicate that a shutdown message should be sent to the peer with the given node_id.
857         SendShutdown {
858                 /// The node_id of the node which should receive this message
859                 node_id: PublicKey,
860                 /// The message which should be sent.
861                 msg: msgs::Shutdown,
862         },
863         /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id.
864         SendChannelReestablish {
865                 /// The node_id of the node which should receive this message
866                 node_id: PublicKey,
867                 /// The message which should be sent.
868                 msg: msgs::ChannelReestablish,
869         },
870         /// Used to indicate that a channel_announcement and channel_update should be broadcast to all
871         /// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
872         ///
873         /// Note that after doing so, you very likely (unless you did so very recently) want to call
874         /// ChannelManager::broadcast_node_announcement to trigger a BroadcastNodeAnnouncement event.
875         /// This ensures that any nodes which see our channel_announcement also have a relevant
876         /// node_announcement, including relevant feature flags which may be important for routing
877         /// through or to us.
878         BroadcastChannelAnnouncement {
879                 /// The channel_announcement which should be sent.
880                 msg: msgs::ChannelAnnouncement,
881                 /// The followup channel_update which should be sent.
882                 update_msg: msgs::ChannelUpdate,
883         },
884         /// Used to indicate that a node_announcement should be broadcast to all peers.
885         BroadcastNodeAnnouncement {
886                 /// The node_announcement which should be sent.
887                 msg: msgs::NodeAnnouncement,
888         },
889         /// Used to indicate that a channel_update should be broadcast to all peers.
890         BroadcastChannelUpdate {
891                 /// The channel_update which should be sent.
892                 msg: msgs::ChannelUpdate,
893         },
894         /// Used to indicate that a channel_update should be sent to a single peer.
895         /// In contrast to [`Self::BroadcastChannelUpdate`], this is used when the channel is a
896         /// private channel and we shouldn't be informing all of our peers of channel parameters.
897         SendChannelUpdate {
898                 /// The node_id of the node which should receive this message
899                 node_id: PublicKey,
900                 /// The channel_update which should be sent.
901                 msg: msgs::ChannelUpdate,
902         },
903         /// Broadcast an error downstream to be handled
904         HandleError {
905                 /// The node_id of the node which should receive this message
906                 node_id: PublicKey,
907                 /// The action which should be taken.
908                 action: msgs::ErrorAction
909         },
910         /// Query a peer for channels with funding transaction UTXOs in a block range.
911         SendChannelRangeQuery {
912                 /// The node_id of this message recipient
913                 node_id: PublicKey,
914                 /// The query_channel_range which should be sent.
915                 msg: msgs::QueryChannelRange,
916         },
917         /// Request routing gossip messages from a peer for a list of channels identified by
918         /// their short_channel_ids.
919         SendShortIdsQuery {
920                 /// The node_id of this message recipient
921                 node_id: PublicKey,
922                 /// The query_short_channel_ids which should be sent.
923                 msg: msgs::QueryShortChannelIds,
924         },
925         /// Sends a reply to a channel range query. This may be one of several SendReplyChannelRange events
926         /// emitted during processing of the query.
927         SendReplyChannelRange {
928                 /// The node_id of this message recipient
929                 node_id: PublicKey,
930                 /// The reply_channel_range which should be sent.
931                 msg: msgs::ReplyChannelRange,
932         },
933         /// Sends a timestamp filter for inbound gossip. This should be sent on each new connection to
934         /// enable receiving gossip messages from the peer.
935         SendGossipTimestampFilter {
936                 /// The node_id of this message recipient
937                 node_id: PublicKey,
938                 /// The gossip_timestamp_filter which should be sent.
939                 msg: msgs::GossipTimestampFilter,
940         },
941 }
942
943 /// A trait indicating an object may generate message send events
944 pub trait MessageSendEventsProvider {
945         /// Gets the list of pending events which were generated by previous actions, clearing the list
946         /// in the process.
947         fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
948 }
949
950 /// A trait indicating an object may generate events.
951 ///
952 /// Events are processed by passing an [`EventHandler`] to [`process_pending_events`].
953 ///
954 /// # Requirements
955 ///
956 /// See [`process_pending_events`] for requirements around event processing.
957 ///
958 /// When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
959 /// event since the last invocation. The handler must either act upon the event immediately
960 /// or preserve it for later handling.
961 ///
962 /// Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
963 /// consult the provider's documentation on the implication of processing events and how a handler
964 /// may safely use the provider (e.g., see [`ChannelManager::process_pending_events`] and
965 /// [`ChainMonitor::process_pending_events`]).
966 ///
967 /// (C-not implementable) As there is likely no reason for a user to implement this trait on their
968 /// own type(s).
969 ///
970 /// [`process_pending_events`]: Self::process_pending_events
971 /// [`handle_event`]: EventHandler::handle_event
972 /// [`ChannelManager::process_pending_events`]: crate::ln::channelmanager::ChannelManager#method.process_pending_events
973 /// [`ChainMonitor::process_pending_events`]: crate::chain::chainmonitor::ChainMonitor#method.process_pending_events
974 pub trait EventsProvider {
975         /// Processes any events generated since the last call using the given event handler.
976         ///
977         /// Subsequent calls must only process new events. However, handlers must be capable of handling
978         /// duplicate events across process restarts. This may occur if the provider was recovered from
979         /// an old state (i.e., it hadn't been successfully persisted after processing pending events).
980         fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler;
981 }
982
983 /// A trait implemented for objects handling events from [`EventsProvider`].
984 pub trait EventHandler {
985         /// Handles the given [`Event`].
986         ///
987         /// See [`EventsProvider`] for details that must be considered when implementing this method.
988         fn handle_event(&self, event: &Event);
989 }
990
991 impl<F> EventHandler for F where F: Fn(&Event) {
992         fn handle_event(&self, event: &Event) {
993                 self(event)
994         }
995 }
996
997 impl<T: EventHandler> EventHandler for Arc<T> {
998         fn handle_event(&self, event: &Event) {
999                 self.deref().handle_event(event)
1000         }
1001 }