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::{PaymentPreimage, PaymentHash, PaymentSecret};
20 use routing::network_graph::NetworkUpdate;
21 use util::ser::{Writeable, Writer, MaybeReadable, Readable, VecReadWrapper, VecWriteWrapper};
23 use bitcoin::blockdata::script::Script;
25 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 /// An Event which you should probably take some action in response to.
74 /// Note that while Writeable and Readable are implemented for Event, you probably shouldn't use
75 /// them directly as they don't round-trip exactly (for example FundingGenerationReady is never
76 /// written as it makes no sense to respond to it after reconnecting to peers).
77 #[derive(Clone, Debug)]
79 /// Used to indicate that the client should generate a funding transaction with the given
80 /// parameters and then call ChannelManager::funding_transaction_generated.
81 /// Generated in ChannelManager message handling.
82 /// Note that *all inputs* in the funding transaction must spend SegWit outputs or your
83 /// counterparty can steal your funds!
84 FundingGenerationReady {
85 /// The random channel_id we picked which you'll need to pass into
86 /// ChannelManager::funding_transaction_generated.
87 temporary_channel_id: [u8; 32],
88 /// The value, in satoshis, that the output should have.
89 channel_value_satoshis: u64,
90 /// The script which should be used in the transaction output.
91 output_script: Script,
92 /// The value passed in to ChannelManager::create_channel
95 /// Indicates we've received money! Just gotta dig out that payment preimage and feed it to
96 /// ChannelManager::claim_funds to get it....
97 /// Note that if the preimage is not known or the amount paid is incorrect, you should call
98 /// ChannelManager::fail_htlc_backwards to free up resources for this HTLC and avoid
99 /// network congestion.
100 /// The amount paid should be considered 'incorrect' when it is less than or more than twice
101 /// the amount expected.
102 /// If you fail to call either ChannelManager::claim_funds or
103 /// ChannelManager::fail_htlc_backwards within the HTLC's timeout, the HTLC will be
104 /// automatically failed.
106 /// The hash for which the preimage should be handed to the ChannelManager.
107 payment_hash: PaymentHash,
108 /// The value, in thousandths of a satoshi, that this payment is for. Note that you must
109 /// compare this to the expected value before accepting the payment (as otherwise you are
110 /// providing proof-of-payment for less than the value you expected!).
112 /// Information for claiming this received payment, based on whether the purpose of the
113 /// payment is to pay an invoice or to send a spontaneous payment.
114 purpose: PaymentPurpose,
116 /// Indicates an outbound payment we made succeeded (i.e. it made it all the way to its target
117 /// and we got back the payment preimage for it).
119 /// Note for MPP payments: in rare cases, this event may be preceded by a `PaymentFailed` event.
120 /// In this situation, you SHOULD treat this payment as having succeeded.
122 /// The preimage to the hash given to ChannelManager::send_payment.
123 /// Note that this serves as a payment receipt, if you wish to have such a thing, you must
124 /// store it somehow!
125 payment_preimage: PaymentPreimage,
127 /// Indicates an outbound payment we made failed. Probably some intermediary node dropped
128 /// something. You may wish to retry with a different route.
130 /// The hash which was given to ChannelManager::send_payment.
131 payment_hash: PaymentHash,
132 /// Indicates the payment was rejected for some reason by the recipient. This implies that
133 /// the payment has failed, not just the route in question. If this is not set, you may
134 /// retry the payment via a different route.
135 rejected_by_dest: bool,
136 /// Any failure information conveyed via the Onion return packet by a node along the failed
139 /// Should be applied to the [`NetworkGraph`] so that routing decisions can take into
140 /// account the update. [`NetGraphMsgHandler`] is capable of doing this.
142 /// [`NetworkGraph`]: crate::routing::network_graph::NetworkGraph
143 /// [`NetGraphMsgHandler`]: crate::routing::network_graph::NetGraphMsgHandler
144 network_update: Option<NetworkUpdate>,
145 /// For both single-path and multi-path payments, this is set if all paths of the payment have
146 /// failed. This will be set to false if (1) this is an MPP payment and (2) other parts of the
147 /// larger MPP payment were still in flight when this event was generated.
148 all_paths_failed: bool,
150 error_code: Option<u16>,
152 error_data: Option<Vec<u8>>,
154 /// Used to indicate that ChannelManager::process_pending_htlc_forwards should be called at a
155 /// time in the future.
156 PendingHTLCsForwardable {
157 /// The minimum amount of time that should be waited prior to calling
158 /// process_pending_htlc_forwards. To increase the effort required to correlate payments,
159 /// you should wait a random amount of time in roughly the range (now + time_forwardable,
160 /// now + 5*time_forwardable).
161 time_forwardable: Duration,
163 /// Used to indicate that an output which you should know how to spend was confirmed on chain
164 /// and is now spendable.
165 /// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
166 /// counterparty spending them due to some kind of timeout. Thus, you need to store them
167 /// somewhere and spend them when you create on-chain transactions.
169 /// The outputs which you should store as spendable by you.
170 outputs: Vec<SpendableOutputDescriptor>,
172 /// This event is generated when a payment has been successfully forwarded through us and a
173 /// forwarding fee earned.
175 /// The fee, in milli-satoshis, which was earned as a result of the payment.
177 /// Note that if we force-closed the channel over which we forwarded an HTLC while the HTLC
178 /// was pending, the amount the next hop claimed will have been rounded down to the nearest
179 /// whole satoshi. Thus, the fee calculated here may be higher than expected as we still
180 /// claimed the full value in millisatoshis from the source. In this case,
181 /// `claim_from_onchain_tx` will be set.
183 /// If the channel which sent us the payment has been force-closed, we will claim the funds
184 /// via an on-chain transaction. In that case we do not yet know the on-chain transaction
185 /// fees which we will spend and will instead set this to `None`. It is possible duplicate
186 /// `PaymentForwarded` events are generated for the same payment iff `fee_earned_msat` is
188 fee_earned_msat: Option<u64>,
189 /// If this is `true`, the forwarded HTLC was claimed by our counterparty via an on-chain
191 claim_from_onchain_tx: bool,
193 /// Used to indicate that a channel was closed at the given timestamp.
195 /// The channel_id which has been barren from further off-chain updates but
196 /// funding output might still be not resolved yet.
197 channel_id: [u8; 32],
198 /// A human-readable error message
203 impl Writeable for Event {
204 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
206 &Event::FundingGenerationReady { .. } => {
208 // We never write out FundingGenerationReady events as, upon disconnection, peers
209 // drop any channels which have not yet exchanged funding_signed.
211 &Event::PaymentReceived { ref payment_hash, ref amt, ref purpose } => {
213 let mut payment_secret = None;
214 let mut user_payment_id = None;
215 let payment_preimage;
217 PaymentPurpose::InvoicePayment { payment_preimage: preimage, payment_secret: secret, user_payment_id: id } => {
218 payment_secret = Some(secret);
219 payment_preimage = *preimage;
220 user_payment_id = Some(id);
222 PaymentPurpose::SpontaneousPayment(preimage) => {
223 payment_preimage = Some(*preimage);
226 write_tlv_fields!(writer, {
227 (0, payment_hash, required),
228 (2, payment_secret, option),
230 (6, user_payment_id, option),
231 (8, payment_preimage, option),
234 &Event::PaymentSent { ref payment_preimage } => {
236 write_tlv_fields!(writer, {
237 (0, payment_preimage, required),
240 &Event::PaymentFailed { ref payment_hash, ref rejected_by_dest, ref network_update, ref all_paths_failed,
248 error_code.write(writer)?;
250 error_data.write(writer)?;
251 write_tlv_fields!(writer, {
252 (0, payment_hash, required),
253 (1, network_update, option),
254 (2, rejected_by_dest, required),
255 (3, all_paths_failed, required),
258 &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
260 write_tlv_fields!(writer, {});
261 // We don't write the time_fordwardable out at all, as we presume when the user
262 // deserializes us at least that much time has elapsed.
264 &Event::SpendableOutputs { ref outputs } => {
266 write_tlv_fields!(writer, {
267 (0, VecWriteWrapper(outputs), required),
270 &Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx } => {
272 write_tlv_fields!(writer, {
273 (0, fee_earned_msat, option),
274 (2, claim_from_onchain_tx, required),
277 &Event::ChannelClosed { ref channel_id, ref err } => {
279 channel_id.write(writer)?;
280 (err.len() as u16).write(writer)?;
281 writer.write_all(err.as_bytes())?;
282 write_tlv_fields!(writer, {});
288 impl MaybeReadable for Event {
289 fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
290 match Readable::read(reader)? {
294 let mut payment_hash = PaymentHash([0; 32]);
295 let mut payment_preimage = None;
296 let mut payment_secret = None;
298 let mut user_payment_id = None;
299 read_tlv_fields!(reader, {
300 (0, payment_hash, required),
301 (2, payment_secret, option),
303 (6, user_payment_id, option),
304 (8, payment_preimage, option),
306 let purpose = match payment_secret {
307 Some(secret) => PaymentPurpose::InvoicePayment {
309 payment_secret: secret,
310 user_payment_id: if let Some(id) = user_payment_id {
312 } else { return Err(msgs::DecodeError::InvalidValue) }
314 None if payment_preimage.is_some() => PaymentPurpose::SpontaneousPayment(payment_preimage.unwrap()),
315 None => return Err(msgs::DecodeError::InvalidValue),
317 Ok(Some(Event::PaymentReceived {
327 let mut payment_preimage = PaymentPreimage([0; 32]);
328 read_tlv_fields!(reader, {
329 (0, payment_preimage, required),
331 Ok(Some(Event::PaymentSent {
340 let error_code = Readable::read(reader)?;
342 let error_data = Readable::read(reader)?;
343 let mut payment_hash = PaymentHash([0; 32]);
344 let mut rejected_by_dest = false;
345 let mut network_update = None;
346 let mut all_paths_failed = Some(true);
347 read_tlv_fields!(reader, {
348 (0, payment_hash, required),
349 (1, network_update, ignorable),
350 (2, rejected_by_dest, required),
351 (3, all_paths_failed, option),
353 Ok(Some(Event::PaymentFailed {
357 all_paths_failed: all_paths_failed.unwrap(),
368 read_tlv_fields!(reader, {});
369 Ok(Some(Event::PendingHTLCsForwardable {
370 time_forwardable: Duration::from_secs(0)
377 let mut outputs = VecReadWrapper(Vec::new());
378 read_tlv_fields!(reader, {
379 (0, outputs, required),
381 Ok(Some(Event::SpendableOutputs { outputs: outputs.0 }))
387 let mut fee_earned_msat = None;
388 let mut claim_from_onchain_tx = false;
389 read_tlv_fields!(reader, {
390 (0, fee_earned_msat, option),
391 (2, claim_from_onchain_tx, required),
393 Ok(Some(Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx }))
397 // Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue.
398 x if x % 2 == 1 => Ok(None),
401 let channel_id = Readable::read(reader)?;
403 let mut size: usize = <u16 as Readable>::read(reader)? as usize;
404 let mut data = vec![];
405 let data_len = reader.read_to_end(&mut data)?;
406 size = cmp::min(data_len, size);
407 match String::from_utf8(data[..size as usize].to_vec()) {
409 Err(_) => return Err(msgs::DecodeError::InvalidValue),
412 read_tlv_fields!(reader, {});
413 Ok(Some(Event::ChannelClosed { channel_id, err: err }))
417 _ => Err(msgs::DecodeError::InvalidValue)
422 /// An event generated by ChannelManager which indicates a message should be sent to a peer (or
423 /// broadcast to most peers).
424 /// These events are handled by PeerManager::process_events if you are using a PeerManager.
425 #[derive(Clone, Debug)]
426 pub enum MessageSendEvent {
427 /// Used to indicate that we've accepted a channel open and should send the accept_channel
428 /// message provided to the given peer.
430 /// The node_id of the node which should receive this message
432 /// The message which should be sent.
433 msg: msgs::AcceptChannel,
435 /// Used to indicate that we've initiated a channel open and should send the open_channel
436 /// message provided to the given peer.
438 /// The node_id of the node which should receive this message
440 /// The message which should be sent.
441 msg: msgs::OpenChannel,
443 /// Used to indicate that a funding_created message should be sent to the peer with the given node_id.
445 /// The node_id of the node which should receive this message
447 /// The message which should be sent.
448 msg: msgs::FundingCreated,
450 /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id.
452 /// The node_id of the node which should receive this message
454 /// The message which should be sent.
455 msg: msgs::FundingSigned,
457 /// Used to indicate that a funding_locked message should be sent to the peer with the given node_id.
459 /// The node_id of the node which should receive these message(s)
461 /// The funding_locked message which should be sent.
462 msg: msgs::FundingLocked,
464 /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
465 SendAnnouncementSignatures {
466 /// The node_id of the node which should receive these message(s)
468 /// The announcement_signatures message which should be sent.
469 msg: msgs::AnnouncementSignatures,
471 /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed
472 /// message should be sent to the peer with the given node_id.
474 /// The node_id of the node which should receive these message(s)
476 /// The update messages which should be sent. ALL messages in the struct should be sent!
477 updates: msgs::CommitmentUpdate,
479 /// Used to indicate that a revoke_and_ack 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::RevokeAndACK,
486 /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id.
488 /// The node_id of the node which should receive this message
490 /// The message which should be sent.
491 msg: msgs::ClosingSigned,
493 /// Used to indicate that a shutdown message should be sent to the peer with the given node_id.
495 /// The node_id of the node which should receive this message
497 /// The message which should be sent.
500 /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id.
501 SendChannelReestablish {
502 /// The node_id of the node which should receive this message
504 /// The message which should be sent.
505 msg: msgs::ChannelReestablish,
507 /// Used to indicate that a channel_announcement and channel_update should be broadcast to all
508 /// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
510 /// Note that after doing so, you very likely (unless you did so very recently) want to call
511 /// ChannelManager::broadcast_node_announcement to trigger a BroadcastNodeAnnouncement event.
512 /// This ensures that any nodes which see our channel_announcement also have a relevant
513 /// node_announcement, including relevant feature flags which may be important for routing
514 /// through or to us.
515 BroadcastChannelAnnouncement {
516 /// The channel_announcement which should be sent.
517 msg: msgs::ChannelAnnouncement,
518 /// The followup channel_update which should be sent.
519 update_msg: msgs::ChannelUpdate,
521 /// Used to indicate that a node_announcement should be broadcast to all peers.
522 BroadcastNodeAnnouncement {
523 /// The node_announcement which should be sent.
524 msg: msgs::NodeAnnouncement,
526 /// Used to indicate that a channel_update should be broadcast to all peers.
527 BroadcastChannelUpdate {
528 /// The channel_update which should be sent.
529 msg: msgs::ChannelUpdate,
531 /// Used to indicate that a channel_update should be sent to a single peer.
532 /// In contrast to [`Self::BroadcastChannelUpdate`], this is used when the channel is a
533 /// private channel and we shouldn't be informing all of our peers of channel parameters.
535 /// The node_id of the node which should receive this message
537 /// The channel_update which should be sent.
538 msg: msgs::ChannelUpdate,
540 /// Broadcast an error downstream to be handled
542 /// The node_id of the node which should receive this message
544 /// The action which should be taken.
545 action: msgs::ErrorAction
547 /// Query a peer for channels with funding transaction UTXOs in a block range.
548 SendChannelRangeQuery {
549 /// The node_id of this message recipient
551 /// The query_channel_range which should be sent.
552 msg: msgs::QueryChannelRange,
554 /// Request routing gossip messages from a peer for a list of channels identified by
555 /// their short_channel_ids.
557 /// The node_id of this message recipient
559 /// The query_short_channel_ids which should be sent.
560 msg: msgs::QueryShortChannelIds,
562 /// Sends a reply to a channel range query. This may be one of several SendReplyChannelRange events
563 /// emitted during processing of the query.
564 SendReplyChannelRange {
565 /// The node_id of this message recipient
567 /// The reply_channel_range which should be sent.
568 msg: msgs::ReplyChannelRange,
572 /// A trait indicating an object may generate message send events
573 pub trait MessageSendEventsProvider {
574 /// Gets the list of pending events which were generated by previous actions, clearing the list
576 fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
579 /// A trait indicating an object may generate events.
581 /// Events are processed by passing an [`EventHandler`] to [`process_pending_events`].
585 /// See [`process_pending_events`] for requirements around event processing.
587 /// When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
588 /// event since the last invocation. The handler must either act upon the event immediately
589 /// or preserve it for later handling.
591 /// Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
592 /// consult the provider's documentation on the implication of processing events and how a handler
593 /// may safely use the provider (e.g., see [`ChannelManager::process_pending_events`] and
594 /// [`ChainMonitor::process_pending_events`]).
596 /// (C-not implementable) As there is likely no reason for a user to implement this trait on their
599 /// [`process_pending_events`]: Self::process_pending_events
600 /// [`handle_event`]: EventHandler::handle_event
601 /// [`ChannelManager::process_pending_events`]: crate::ln::channelmanager::ChannelManager#method.process_pending_events
602 /// [`ChainMonitor::process_pending_events`]: crate::chain::chainmonitor::ChainMonitor#method.process_pending_events
603 pub trait EventsProvider {
604 /// Processes any events generated since the last call using the given event handler.
606 /// Subsequent calls must only process new events. However, handlers must be capable of handling
607 /// duplicate events across process restarts. This may occur if the provider was recovered from
608 /// an old state (i.e., it hadn't been successfully persisted after processing pending events).
609 fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler;
612 /// A trait implemented for objects handling events from [`EventsProvider`].
613 pub trait EventHandler {
614 /// Handles the given [`Event`].
616 /// See [`EventsProvider`] for details that must be considered when implementing this method.
617 fn handle_event(&self, event: &Event);
620 impl<F> EventHandler for F where F: Fn(&Event) {
621 fn handle_event(&self, event: &Event) {