1 // This file is Copyright its original authors, visible in version control
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
10 //! Events are returned from various bits in the library which indicate some action must be taken
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
17 use chain::keysinterface::SpendableOutputDescriptor;
19 use ln::msgs::DecodeError;
20 use ln::{PaymentPreimage, PaymentHash, PaymentSecret};
21 use routing::network_graph::NetworkUpdate;
22 use util::ser::{Writeable, Writer, MaybeReadable, Readable, VecReadWrapper, VecWriteWrapper};
24 use bitcoin::blockdata::script::Script;
26 use bitcoin::secp256k1::key::PublicKey;
30 use core::time::Duration;
33 /// Some information provided on receipt of payment depends on whether the payment received is a
34 /// spontaneous payment or a "conventional" lightning payment that's paying an invoice.
35 #[derive(Clone, Debug)]
36 pub enum PaymentPurpose {
37 /// Information for receiving a payment that we generated an invoice for.
39 /// The preimage to the payment_hash, if the payment hash (and secret) were fetched via
40 /// [`ChannelManager::create_inbound_payment`]. If provided, this can be handed directly to
41 /// [`ChannelManager::claim_funds`].
43 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
44 /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
45 payment_preimage: Option<PaymentPreimage>,
46 /// The "payment secret". This authenticates the sender to the recipient, preventing a
47 /// number of deanonymization attacks during the routing process.
48 /// It is provided here for your reference, however its accuracy is enforced directly by
49 /// [`ChannelManager`] using the values you previously provided to
50 /// [`ChannelManager::create_inbound_payment`] or
51 /// [`ChannelManager::create_inbound_payment_for_hash`].
53 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
54 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
55 /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
56 payment_secret: PaymentSecret,
57 /// This is the `user_payment_id` which was provided to
58 /// [`ChannelManager::create_inbound_payment_for_hash`] or
59 /// [`ChannelManager::create_inbound_payment`]. It has no meaning inside of LDK and is
60 /// simply copied here. It may be used to correlate PaymentReceived events with invoice
61 /// metadata stored elsewhere.
63 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
64 /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
67 /// Because this is a spontaneous payment, the payer generated their own preimage rather than us
68 /// (the payee) providing a preimage.
69 SpontaneousPayment(PaymentPreimage),
72 #[derive(Clone, Debug, PartialEq)]
73 /// The reason which the channel was closed. See individual variants more details.
74 pub enum ClosureReason {
75 /// Closure generated from receiving a peer error message.
76 CounterpartyForceClosed {
77 /// The error which the peer sent us.
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 trigger
81 /// a security in the terminal emulator or the logging subsystem.
84 /// Closure generated from [`ChannelManager::force_close_channel`], called by the user.
86 /// The channel was closed after negotiating a cooperative close and we've now broadcasted
87 /// the cooperative close transaction. Note the shutdown may have been initiated by us.
88 //TODO: split between CounterpartyInitiated/LocallyInitiated
90 /// A commitment transaction was confirmed on chain, closing the channel. Most likely this
91 /// commitment transaction came from our counterparty, but it may also have come from
92 /// a copy of our own `ChannelMonitor`.
93 CommitmentTxBroadcasted,
94 /// Closure generated from processing an event, likely a HTLC forward/relay/reception.
98 /// The `PeerManager` informed us that we've disconnected from the peer and that it is
99 /// unlikely we'll be able to connect to the peer, most likely because we have incompatible
100 /// features and the peer, or we, require features which we, or the peer, do not support.
104 impl_writeable_tlv_based_enum_upgradable!(ClosureReason,
105 (0, CounterpartyForceClosed) => { (1, peer_msg, required) },
106 (2, HolderForceClosed) => {},
107 (6, CommitmentTxBroadcasted) => {},
108 (4, CooperativeClosure) => {},
109 (8, ProcessingError) => { (1, err, required) },
110 (10, DisconnectedPeer) => {},
113 /// An Event which you should probably take some action in response to.
115 /// Note that while Writeable and Readable are implemented for Event, you probably shouldn't use
116 /// them directly as they don't round-trip exactly (for example FundingGenerationReady is never
117 /// written as it makes no sense to respond to it after reconnecting to peers).
118 #[derive(Clone, Debug)]
120 /// Used to indicate that the client should generate a funding transaction with the given
121 /// parameters and then call ChannelManager::funding_transaction_generated.
122 /// Generated in ChannelManager message handling.
123 /// Note that *all inputs* in the funding transaction must spend SegWit outputs or your
124 /// counterparty can steal your funds!
125 FundingGenerationReady {
126 /// The random channel_id we picked which you'll need to pass into
127 /// ChannelManager::funding_transaction_generated.
128 temporary_channel_id: [u8; 32],
129 /// The value, in satoshis, that the output should have.
130 channel_value_satoshis: u64,
131 /// The script which should be used in the transaction output.
132 output_script: Script,
133 /// The value passed in to ChannelManager::create_channel
134 user_channel_id: u64,
136 /// Indicates we've received money! Just gotta dig out that payment preimage and feed it to
137 /// ChannelManager::claim_funds to get it....
138 /// Note that if the preimage is not known or the amount paid is incorrect, you should call
139 /// ChannelManager::fail_htlc_backwards to free up resources for this HTLC and avoid
140 /// network congestion.
141 /// The amount paid should be considered 'incorrect' when it is less than or more than twice
142 /// the amount expected.
143 /// If you fail to call either ChannelManager::claim_funds or
144 /// ChannelManager::fail_htlc_backwards within the HTLC's timeout, the HTLC will be
145 /// automatically failed.
147 /// The hash for which the preimage should be handed to the ChannelManager.
148 payment_hash: PaymentHash,
149 /// The value, in thousandths of a satoshi, that this payment is for. Note that you must
150 /// compare this to the expected value before accepting the payment (as otherwise you are
151 /// providing proof-of-payment for less than the value you expected!).
153 /// Information for claiming this received payment, based on whether the purpose of the
154 /// payment is to pay an invoice or to send a spontaneous payment.
155 purpose: PaymentPurpose,
157 /// Indicates an outbound payment we made succeeded (i.e. it made it all the way to its target
158 /// and we got back the payment preimage for it).
160 /// Note for MPP payments: in rare cases, this event may be preceded by a `PaymentFailed` event.
161 /// In this situation, you SHOULD treat this payment as having succeeded.
163 /// The preimage to the hash given to ChannelManager::send_payment.
164 /// Note that this serves as a payment receipt, if you wish to have such a thing, you must
165 /// store it somehow!
166 payment_preimage: PaymentPreimage,
168 /// Indicates an outbound payment we made failed. Probably some intermediary node dropped
169 /// something. You may wish to retry with a different route.
171 /// The hash which was given to ChannelManager::send_payment.
172 payment_hash: PaymentHash,
173 /// Indicates the payment was rejected for some reason by the recipient. This implies that
174 /// the payment has failed, not just the route in question. If this is not set, you may
175 /// retry the payment via a different route.
176 rejected_by_dest: bool,
177 /// Any failure information conveyed via the Onion return packet by a node along the failed
180 /// Should be applied to the [`NetworkGraph`] so that routing decisions can take into
181 /// account the update. [`NetGraphMsgHandler`] is capable of doing this.
183 /// [`NetworkGraph`]: crate::routing::network_graph::NetworkGraph
184 /// [`NetGraphMsgHandler`]: crate::routing::network_graph::NetGraphMsgHandler
185 network_update: Option<NetworkUpdate>,
186 /// For both single-path and multi-path payments, this is set if all paths of the payment have
187 /// failed. This will be set to false if (1) this is an MPP payment and (2) other parts of the
188 /// larger MPP payment were still in flight when this event was generated.
189 all_paths_failed: bool,
191 error_code: Option<u16>,
193 error_data: Option<Vec<u8>>,
195 /// Used to indicate that ChannelManager::process_pending_htlc_forwards should be called at a
196 /// time in the future.
197 PendingHTLCsForwardable {
198 /// The minimum amount of time that should be waited prior to calling
199 /// process_pending_htlc_forwards. To increase the effort required to correlate payments,
200 /// you should wait a random amount of time in roughly the range (now + time_forwardable,
201 /// now + 5*time_forwardable).
202 time_forwardable: Duration,
204 /// Used to indicate that an output which you should know how to spend was confirmed on chain
205 /// and is now spendable.
206 /// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
207 /// counterparty spending them due to some kind of timeout. Thus, you need to store them
208 /// somewhere and spend them when you create on-chain transactions.
210 /// The outputs which you should store as spendable by you.
211 outputs: Vec<SpendableOutputDescriptor>,
213 /// This event is generated when a payment has been successfully forwarded through us and a
214 /// forwarding fee earned.
216 /// The fee, in milli-satoshis, which was earned as a result of the payment.
218 /// Note that if we force-closed the channel over which we forwarded an HTLC while the HTLC
219 /// was pending, the amount the next hop claimed will have been rounded down to the nearest
220 /// whole satoshi. Thus, the fee calculated here may be higher than expected as we still
221 /// claimed the full value in millisatoshis from the source. In this case,
222 /// `claim_from_onchain_tx` will be set.
224 /// If the channel which sent us the payment has been force-closed, we will claim the funds
225 /// via an on-chain transaction. In that case we do not yet know the on-chain transaction
226 /// fees which we will spend and will instead set this to `None`. It is possible duplicate
227 /// `PaymentForwarded` events are generated for the same payment iff `fee_earned_msat` is
229 fee_earned_msat: Option<u64>,
230 /// If this is `true`, the forwarded HTLC was claimed by our counterparty via an on-chain
232 claim_from_onchain_tx: bool,
234 /// Used to indicate that a channel with the given `channel_id` is in the process of closure.
236 /// The channel_id of the channel which has been closed. Note that on-chain transactions
237 /// resolving the channel are likely still awaiting confirmation.
238 channel_id: [u8; 32],
239 /// The reason the channel was closed.
240 reason: ClosureReason
244 impl Writeable for Event {
245 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
247 &Event::FundingGenerationReady { .. } => {
249 // We never write out FundingGenerationReady events as, upon disconnection, peers
250 // drop any channels which have not yet exchanged funding_signed.
252 &Event::PaymentReceived { ref payment_hash, ref amt, ref purpose } => {
254 let mut payment_secret = None;
255 let mut user_payment_id = None;
256 let payment_preimage;
258 PaymentPurpose::InvoicePayment { payment_preimage: preimage, payment_secret: secret, user_payment_id: id } => {
259 payment_secret = Some(secret);
260 payment_preimage = *preimage;
261 user_payment_id = Some(id);
263 PaymentPurpose::SpontaneousPayment(preimage) => {
264 payment_preimage = Some(*preimage);
267 write_tlv_fields!(writer, {
268 (0, payment_hash, required),
269 (2, payment_secret, option),
271 (6, user_payment_id, option),
272 (8, payment_preimage, option),
275 &Event::PaymentSent { ref payment_preimage } => {
277 write_tlv_fields!(writer, {
278 (0, payment_preimage, required),
281 &Event::PaymentFailed { ref payment_hash, ref rejected_by_dest, ref network_update, ref all_paths_failed,
289 error_code.write(writer)?;
291 error_data.write(writer)?;
292 write_tlv_fields!(writer, {
293 (0, payment_hash, required),
294 (1, network_update, option),
295 (2, rejected_by_dest, required),
296 (3, all_paths_failed, required),
299 &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
301 write_tlv_fields!(writer, {});
302 // We don't write the time_fordwardable out at all, as we presume when the user
303 // deserializes us at least that much time has elapsed.
305 &Event::SpendableOutputs { ref outputs } => {
307 write_tlv_fields!(writer, {
308 (0, VecWriteWrapper(outputs), required),
311 &Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx } => {
313 write_tlv_fields!(writer, {
314 (0, fee_earned_msat, option),
315 (2, claim_from_onchain_tx, required),
318 &Event::ChannelClosed { ref channel_id, ref reason } => {
320 channel_id.write(writer)?;
321 reason.write(writer)?;
322 write_tlv_fields!(writer, {});
328 impl MaybeReadable for Event {
329 fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
330 match Readable::read(reader)? {
334 let mut payment_hash = PaymentHash([0; 32]);
335 let mut payment_preimage = None;
336 let mut payment_secret = None;
338 let mut user_payment_id = None;
339 read_tlv_fields!(reader, {
340 (0, payment_hash, required),
341 (2, payment_secret, option),
343 (6, user_payment_id, option),
344 (8, payment_preimage, option),
346 let purpose = match payment_secret {
347 Some(secret) => PaymentPurpose::InvoicePayment {
349 payment_secret: secret,
350 user_payment_id: if let Some(id) = user_payment_id {
352 } else { return Err(msgs::DecodeError::InvalidValue) }
354 None if payment_preimage.is_some() => PaymentPurpose::SpontaneousPayment(payment_preimage.unwrap()),
355 None => return Err(msgs::DecodeError::InvalidValue),
357 Ok(Some(Event::PaymentReceived {
367 let mut payment_preimage = PaymentPreimage([0; 32]);
368 read_tlv_fields!(reader, {
369 (0, payment_preimage, required),
371 Ok(Some(Event::PaymentSent {
380 let error_code = Readable::read(reader)?;
382 let error_data = Readable::read(reader)?;
383 let mut payment_hash = PaymentHash([0; 32]);
384 let mut rejected_by_dest = false;
385 let mut network_update = None;
386 let mut all_paths_failed = Some(true);
387 read_tlv_fields!(reader, {
388 (0, payment_hash, required),
389 (1, network_update, ignorable),
390 (2, rejected_by_dest, required),
391 (3, all_paths_failed, option),
393 Ok(Some(Event::PaymentFailed {
397 all_paths_failed: all_paths_failed.unwrap(),
408 read_tlv_fields!(reader, {});
409 Ok(Some(Event::PendingHTLCsForwardable {
410 time_forwardable: Duration::from_secs(0)
417 let mut outputs = VecReadWrapper(Vec::new());
418 read_tlv_fields!(reader, {
419 (0, outputs, required),
421 Ok(Some(Event::SpendableOutputs { outputs: outputs.0 }))
427 let mut fee_earned_msat = None;
428 let mut claim_from_onchain_tx = false;
429 read_tlv_fields!(reader, {
430 (0, fee_earned_msat, option),
431 (2, claim_from_onchain_tx, required),
433 Ok(Some(Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx }))
438 let channel_id = Readable::read(reader)?;
439 let reason = MaybeReadable::read(reader)?;
440 read_tlv_fields!(reader, {});
441 if reason.is_none() { return Ok(None); }
442 Ok(Some(Event::ChannelClosed { channel_id, reason: reason.unwrap() }))
444 // Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue.
445 x if x % 2 == 1 => Ok(None),
446 _ => Err(msgs::DecodeError::InvalidValue)
451 /// An event generated by ChannelManager which indicates a message should be sent to a peer (or
452 /// broadcast to most peers).
453 /// These events are handled by PeerManager::process_events if you are using a PeerManager.
454 #[derive(Clone, Debug)]
455 pub enum MessageSendEvent {
456 /// Used to indicate that we've accepted a channel open and should send the accept_channel
457 /// message provided to the given peer.
459 /// The node_id of the node which should receive this message
461 /// The message which should be sent.
462 msg: msgs::AcceptChannel,
464 /// Used to indicate that we've initiated a channel open and should send the open_channel
465 /// message provided to the given peer.
467 /// The node_id of the node which should receive this message
469 /// The message which should be sent.
470 msg: msgs::OpenChannel,
472 /// Used to indicate that a funding_created message should be sent to the peer with the given node_id.
474 /// The node_id of the node which should receive this message
476 /// The message which should be sent.
477 msg: msgs::FundingCreated,
479 /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id.
481 /// The node_id of the node which should receive this message
483 /// The message which should be sent.
484 msg: msgs::FundingSigned,
486 /// Used to indicate that a funding_locked message should be sent to the peer with the given node_id.
488 /// The node_id of the node which should receive these message(s)
490 /// The funding_locked message which should be sent.
491 msg: msgs::FundingLocked,
493 /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
494 SendAnnouncementSignatures {
495 /// The node_id of the node which should receive these message(s)
497 /// The announcement_signatures message which should be sent.
498 msg: msgs::AnnouncementSignatures,
500 /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed
501 /// message should be sent to the peer with the given node_id.
503 /// The node_id of the node which should receive these message(s)
505 /// The update messages which should be sent. ALL messages in the struct should be sent!
506 updates: msgs::CommitmentUpdate,
508 /// Used to indicate that a revoke_and_ack message should be sent to the peer with the given node_id.
510 /// The node_id of the node which should receive this message
512 /// The message which should be sent.
513 msg: msgs::RevokeAndACK,
515 /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id.
517 /// The node_id of the node which should receive this message
519 /// The message which should be sent.
520 msg: msgs::ClosingSigned,
522 /// Used to indicate that a shutdown message should be sent to the peer with the given node_id.
524 /// The node_id of the node which should receive this message
526 /// The message which should be sent.
529 /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id.
530 SendChannelReestablish {
531 /// The node_id of the node which should receive this message
533 /// The message which should be sent.
534 msg: msgs::ChannelReestablish,
536 /// Used to indicate that a channel_announcement and channel_update should be broadcast to all
537 /// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
539 /// Note that after doing so, you very likely (unless you did so very recently) want to call
540 /// ChannelManager::broadcast_node_announcement to trigger a BroadcastNodeAnnouncement event.
541 /// This ensures that any nodes which see our channel_announcement also have a relevant
542 /// node_announcement, including relevant feature flags which may be important for routing
543 /// through or to us.
544 BroadcastChannelAnnouncement {
545 /// The channel_announcement which should be sent.
546 msg: msgs::ChannelAnnouncement,
547 /// The followup channel_update which should be sent.
548 update_msg: msgs::ChannelUpdate,
550 /// Used to indicate that a node_announcement should be broadcast to all peers.
551 BroadcastNodeAnnouncement {
552 /// The node_announcement which should be sent.
553 msg: msgs::NodeAnnouncement,
555 /// Used to indicate that a channel_update should be broadcast to all peers.
556 BroadcastChannelUpdate {
557 /// The channel_update which should be sent.
558 msg: msgs::ChannelUpdate,
560 /// Used to indicate that a channel_update should be sent to a single peer.
561 /// In contrast to [`Self::BroadcastChannelUpdate`], this is used when the channel is a
562 /// private channel and we shouldn't be informing all of our peers of channel parameters.
564 /// The node_id of the node which should receive this message
566 /// The channel_update which should be sent.
567 msg: msgs::ChannelUpdate,
569 /// Broadcast an error downstream to be handled
571 /// The node_id of the node which should receive this message
573 /// The action which should be taken.
574 action: msgs::ErrorAction
576 /// Query a peer for channels with funding transaction UTXOs in a block range.
577 SendChannelRangeQuery {
578 /// The node_id of this message recipient
580 /// The query_channel_range which should be sent.
581 msg: msgs::QueryChannelRange,
583 /// Request routing gossip messages from a peer for a list of channels identified by
584 /// their short_channel_ids.
586 /// The node_id of this message recipient
588 /// The query_short_channel_ids which should be sent.
589 msg: msgs::QueryShortChannelIds,
591 /// Sends a reply to a channel range query. This may be one of several SendReplyChannelRange events
592 /// emitted during processing of the query.
593 SendReplyChannelRange {
594 /// The node_id of this message recipient
596 /// The reply_channel_range which should be sent.
597 msg: msgs::ReplyChannelRange,
601 /// A trait indicating an object may generate message send events
602 pub trait MessageSendEventsProvider {
603 /// Gets the list of pending events which were generated by previous actions, clearing the list
605 fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
608 /// A trait indicating an object may generate events.
610 /// Events are processed by passing an [`EventHandler`] to [`process_pending_events`].
614 /// See [`process_pending_events`] for requirements around event processing.
616 /// When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
617 /// event since the last invocation. The handler must either act upon the event immediately
618 /// or preserve it for later handling.
620 /// Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
621 /// consult the provider's documentation on the implication of processing events and how a handler
622 /// may safely use the provider (e.g., see [`ChannelManager::process_pending_events`] and
623 /// [`ChainMonitor::process_pending_events`]).
625 /// (C-not implementable) As there is likely no reason for a user to implement this trait on their
628 /// [`process_pending_events`]: Self::process_pending_events
629 /// [`handle_event`]: EventHandler::handle_event
630 /// [`ChannelManager::process_pending_events`]: crate::ln::channelmanager::ChannelManager#method.process_pending_events
631 /// [`ChainMonitor::process_pending_events`]: crate::chain::chainmonitor::ChainMonitor#method.process_pending_events
632 pub trait EventsProvider {
633 /// Processes any events generated since the last call using the given event handler.
635 /// Subsequent calls must only process new events. However, handlers must be capable of handling
636 /// duplicate events across process restarts. This may occur if the provider was recovered from
637 /// an old state (i.e., it hadn't been successfully persisted after processing pending events).
638 fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler;
641 /// A trait implemented for objects handling events from [`EventsProvider`].
642 pub trait EventHandler {
643 /// Handles the given [`Event`].
645 /// See [`EventsProvider`] for details that must be considered when implementing this method.
646 fn handle_event(&self, event: &Event);
649 impl<F> EventHandler for F where F: Fn(&Event) {
650 fn handle_event(&self, event: &Event) {