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
18 use ln::{PaymentPreimage, PaymentHash, PaymentSecret};
19 use chain::keysinterface::SpendableOutputDescriptor;
20 use util::ser::{Writeable, Writer, MaybeReadable, Readable, VecReadWrapper, VecWriteWrapper};
22 use bitcoin::blockdata::script::Script;
24 use bitcoin::secp256k1::key::PublicKey;
28 use core::time::Duration;
31 /// Some information provided on receipt of payment depends on whether the payment received is a
32 /// spontaneous payment or a "conventional" lightning payment that's paying an invoice.
33 #[derive(Clone, Debug)]
34 pub enum PaymentPurpose {
35 /// Information for receiving a payment that we generated an invoice for.
37 /// The preimage to the payment_hash, if the payment hash (and secret) were fetched via
38 /// [`ChannelManager::create_inbound_payment`]. If provided, this can be handed directly to
39 /// [`ChannelManager::claim_funds`].
41 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
42 /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
43 payment_preimage: Option<PaymentPreimage>,
44 /// The "payment secret". This authenticates the sender to the recipient, preventing a
45 /// number of deanonymization attacks during the routing process.
46 /// It is provided here for your reference, however its accuracy is enforced directly by
47 /// [`ChannelManager`] using the values you previously provided to
48 /// [`ChannelManager::create_inbound_payment`] or
49 /// [`ChannelManager::create_inbound_payment_for_hash`].
51 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
52 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
53 /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
54 payment_secret: PaymentSecret,
55 /// This is the `user_payment_id` which was provided to
56 /// [`ChannelManager::create_inbound_payment_for_hash`] or
57 /// [`ChannelManager::create_inbound_payment`]. It has no meaning inside of LDK and is
58 /// simply copied here. It may be used to correlate PaymentReceived events with invoice
59 /// metadata stored elsewhere.
61 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
62 /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
65 /// Because this is a spontaneous payment, the payer generated their own preimage rather than us
66 /// (the payee) providing a preimage.
67 SpontaneousPayment(PaymentPreimage),
70 /// An Event which you should probably take some action in response to.
72 /// Note that while Writeable and Readable are implemented for Event, you probably shouldn't use
73 /// them directly as they don't round-trip exactly (for example FundingGenerationReady is never
74 /// written as it makes no sense to respond to it after reconnecting to peers).
75 #[derive(Clone, Debug)]
77 /// Used to indicate that the client should generate a funding transaction with the given
78 /// parameters and then call ChannelManager::funding_transaction_generated.
79 /// Generated in ChannelManager message handling.
80 /// Note that *all inputs* in the funding transaction must spend SegWit outputs or your
81 /// counterparty can steal your funds!
82 FundingGenerationReady {
83 /// The random channel_id we picked which you'll need to pass into
84 /// ChannelManager::funding_transaction_generated.
85 temporary_channel_id: [u8; 32],
86 /// The value, in satoshis, that the output should have.
87 channel_value_satoshis: u64,
88 /// The script which should be used in the transaction output.
89 output_script: Script,
90 /// The value passed in to ChannelManager::create_channel
93 /// Indicates we've received money! Just gotta dig out that payment preimage and feed it to
94 /// ChannelManager::claim_funds to get it....
95 /// Note that if the preimage is not known or the amount paid is incorrect, you should call
96 /// ChannelManager::fail_htlc_backwards to free up resources for this HTLC and avoid
97 /// network congestion.
98 /// The amount paid should be considered 'incorrect' when it is less than or more than twice
99 /// the amount expected.
100 /// If you fail to call either ChannelManager::claim_funds or
101 /// ChannelManager::fail_htlc_backwards within the HTLC's timeout, the HTLC will be
102 /// automatically failed.
104 /// The hash for which the preimage should be handed to the ChannelManager.
105 payment_hash: PaymentHash,
106 /// The value, in thousandths of a satoshi, that this payment is for. Note that you must
107 /// compare this to the expected value before accepting the payment (as otherwise you are
108 /// providing proof-of-payment for less than the value you expected!).
110 /// Information for claiming this received payment, based on whether the purpose of the
111 /// payment is to pay an invoice or to send a spontaneous payment.
112 purpose: PaymentPurpose,
114 /// Indicates an outbound payment we made succeeded (ie it made it all the way to its target
115 /// and we got back the payment preimage for it).
117 /// The preimage to the hash given to ChannelManager::send_payment.
118 /// Note that this serves as a payment receipt, if you wish to have such a thing, you must
119 /// store it somehow!
120 payment_preimage: PaymentPreimage,
122 /// Indicates an outbound payment we made failed. Probably some intermediary node dropped
123 /// something. You may wish to retry with a different route.
125 /// The hash which was given to ChannelManager::send_payment.
126 payment_hash: PaymentHash,
127 /// Indicates the payment was rejected for some reason by the recipient. This implies that
128 /// the payment has failed, not just the route in question. If this is not set, you may
129 /// retry the payment via a different route.
130 rejected_by_dest: bool,
132 error_code: Option<u16>,
134 error_data: Option<Vec<u8>>,
136 /// Used to indicate that ChannelManager::process_pending_htlc_forwards should be called at a
137 /// time in the future.
138 PendingHTLCsForwardable {
139 /// The minimum amount of time that should be waited prior to calling
140 /// process_pending_htlc_forwards. To increase the effort required to correlate payments,
141 /// you should wait a random amount of time in roughly the range (now + time_forwardable,
142 /// now + 5*time_forwardable).
143 time_forwardable: Duration,
145 /// Used to indicate that an output which you should know how to spend was confirmed on chain
146 /// and is now spendable.
147 /// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
148 /// counterparty spending them due to some kind of timeout. Thus, you need to store them
149 /// somewhere and spend them when you create on-chain transactions.
151 /// The outputs which you should store as spendable by you.
152 outputs: Vec<SpendableOutputDescriptor>,
154 /// This event is generated when a payment has been successfully forwarded through us and a
155 /// forwarding fee earned.
157 /// The fee, in milli-satoshis, which was earned as a result of the payment.
159 /// Note that if we force-closed the channel over which we forwarded an HTLC while the HTLC
160 /// was pending, the amount the next hop claimed will have been rounded down to the nearest
161 /// whole satoshi. Thus, the fee calculated here may be higher than expected as we still
162 /// claimed the full value in millisatoshis from the source. In this case,
163 /// `claim_from_onchain_tx` will be set.
165 /// If the channel which sent us the payment has been force-closed, we will claim the funds
166 /// via an on-chain transaction. In that case we do not yet know the on-chain transaction
167 /// fees which we will spend and will instead set this to `None`. It is possible duplicate
168 /// `PaymentForwarded` events are generated for the same payment iff `fee_earned_msat` is
170 fee_earned_msat: Option<u64>,
171 /// If this is `true`, the forwarded HTLC was claimed by our counterparty via an on-chain
173 claim_from_onchain_tx: bool,
177 impl Writeable for Event {
178 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
180 &Event::FundingGenerationReady { .. } => {
182 // We never write out FundingGenerationReady events as, upon disconnection, peers
183 // drop any channels which have not yet exchanged funding_signed.
185 &Event::PaymentReceived { ref payment_hash, ref amt, ref purpose } => {
187 let mut payment_secret = None;
188 let mut user_payment_id = None;
189 let payment_preimage;
191 PaymentPurpose::InvoicePayment { payment_preimage: preimage, payment_secret: secret, user_payment_id: id } => {
192 payment_secret = Some(secret);
193 payment_preimage = *preimage;
194 user_payment_id = Some(id);
196 PaymentPurpose::SpontaneousPayment(preimage) => {
197 payment_preimage = Some(*preimage);
200 write_tlv_fields!(writer, {
201 (0, payment_hash, required),
202 (2, payment_secret, option),
204 (6, user_payment_id, option),
205 (8, payment_preimage, option),
208 &Event::PaymentSent { ref payment_preimage } => {
210 write_tlv_fields!(writer, {
211 (0, payment_preimage, required),
214 &Event::PaymentFailed { ref payment_hash, ref rejected_by_dest,
222 error_code.write(writer)?;
224 error_data.write(writer)?;
225 write_tlv_fields!(writer, {
226 (0, payment_hash, required),
227 (2, rejected_by_dest, required),
230 &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
232 write_tlv_fields!(writer, {});
233 // We don't write the time_fordwardable out at all, as we presume when the user
234 // deserializes us at least that much time has elapsed.
236 &Event::SpendableOutputs { ref outputs } => {
238 write_tlv_fields!(writer, {
239 (0, VecWriteWrapper(outputs), required),
242 &Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx } => {
244 write_tlv_fields!(writer, {
245 (0, fee_earned_msat, option),
246 (2, claim_from_onchain_tx, required),
253 impl MaybeReadable for Event {
254 fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
255 match Readable::read(reader)? {
259 let mut payment_hash = PaymentHash([0; 32]);
260 let mut payment_preimage = None;
261 let mut payment_secret = None;
263 let mut user_payment_id = None;
264 read_tlv_fields!(reader, {
265 (0, payment_hash, required),
266 (2, payment_secret, option),
268 (6, user_payment_id, option),
269 (8, payment_preimage, option),
271 let purpose = match payment_secret {
272 Some(secret) => PaymentPurpose::InvoicePayment {
274 payment_secret: secret,
275 user_payment_id: if let Some(id) = user_payment_id {
277 } else { return Err(msgs::DecodeError::InvalidValue) }
279 None if payment_preimage.is_some() => PaymentPurpose::SpontaneousPayment(payment_preimage.unwrap()),
280 None => return Err(msgs::DecodeError::InvalidValue),
282 Ok(Some(Event::PaymentReceived {
292 let mut payment_preimage = PaymentPreimage([0; 32]);
293 read_tlv_fields!(reader, {
294 (0, payment_preimage, required),
296 Ok(Some(Event::PaymentSent {
305 let error_code = Readable::read(reader)?;
307 let error_data = Readable::read(reader)?;
308 let mut payment_hash = PaymentHash([0; 32]);
309 let mut rejected_by_dest = false;
310 read_tlv_fields!(reader, {
311 (0, payment_hash, required),
312 (2, rejected_by_dest, required),
314 Ok(Some(Event::PaymentFailed {
327 read_tlv_fields!(reader, {});
328 Ok(Some(Event::PendingHTLCsForwardable {
329 time_forwardable: Duration::from_secs(0)
336 let mut outputs = VecReadWrapper(Vec::new());
337 read_tlv_fields!(reader, {
338 (0, outputs, required),
340 Ok(Some(Event::SpendableOutputs { outputs: outputs.0 }))
346 let mut fee_earned_msat = None;
347 let mut claim_from_onchain_tx = false;
348 read_tlv_fields!(reader, {
349 (0, fee_earned_msat, option),
350 (2, claim_from_onchain_tx, required),
352 Ok(Some(Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx }))
356 // Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue.
357 x if x % 2 == 1 => Ok(None),
358 _ => Err(msgs::DecodeError::InvalidValue)
363 /// An event generated by ChannelManager which indicates a message should be sent to a peer (or
364 /// broadcast to most peers).
365 /// These events are handled by PeerManager::process_events if you are using a PeerManager.
366 #[derive(Clone, Debug)]
367 pub enum MessageSendEvent {
368 /// Used to indicate that we've accepted a channel open and should send the accept_channel
369 /// message provided to the given peer.
371 /// The node_id of the node which should receive this message
373 /// The message which should be sent.
374 msg: msgs::AcceptChannel,
376 /// Used to indicate that we've initiated a channel open and should send the open_channel
377 /// message provided to the given peer.
379 /// The node_id of the node which should receive this message
381 /// The message which should be sent.
382 msg: msgs::OpenChannel,
384 /// Used to indicate that a funding_created message should be sent to the peer with the given node_id.
386 /// The node_id of the node which should receive this message
388 /// The message which should be sent.
389 msg: msgs::FundingCreated,
391 /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id.
393 /// The node_id of the node which should receive this message
395 /// The message which should be sent.
396 msg: msgs::FundingSigned,
398 /// Used to indicate that a funding_locked message should be sent to the peer with the given node_id.
400 /// The node_id of the node which should receive these message(s)
402 /// The funding_locked message which should be sent.
403 msg: msgs::FundingLocked,
405 /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
406 SendAnnouncementSignatures {
407 /// The node_id of the node which should receive these message(s)
409 /// The announcement_signatures message which should be sent.
410 msg: msgs::AnnouncementSignatures,
412 /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed
413 /// message should be sent to the peer with the given node_id.
415 /// The node_id of the node which should receive these message(s)
417 /// The update messages which should be sent. ALL messages in the struct should be sent!
418 updates: msgs::CommitmentUpdate,
420 /// Used to indicate that a revoke_and_ack message should be sent to the peer with the given node_id.
422 /// The node_id of the node which should receive this message
424 /// The message which should be sent.
425 msg: msgs::RevokeAndACK,
427 /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id.
429 /// The node_id of the node which should receive this message
431 /// The message which should be sent.
432 msg: msgs::ClosingSigned,
434 /// Used to indicate that a shutdown message should be sent to the peer with the given node_id.
436 /// The node_id of the node which should receive this message
438 /// The message which should be sent.
441 /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id.
442 SendChannelReestablish {
443 /// The node_id of the node which should receive this message
445 /// The message which should be sent.
446 msg: msgs::ChannelReestablish,
448 /// Used to indicate that a channel_announcement and channel_update should be broadcast to all
449 /// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
451 /// Note that after doing so, you very likely (unless you did so very recently) want to call
452 /// ChannelManager::broadcast_node_announcement to trigger a BroadcastNodeAnnouncement event.
453 /// This ensures that any nodes which see our channel_announcement also have a relevant
454 /// node_announcement, including relevant feature flags which may be important for routing
455 /// through or to us.
456 BroadcastChannelAnnouncement {
457 /// The channel_announcement which should be sent.
458 msg: msgs::ChannelAnnouncement,
459 /// The followup channel_update which should be sent.
460 update_msg: msgs::ChannelUpdate,
462 /// Used to indicate that a node_announcement should be broadcast to all peers.
463 BroadcastNodeAnnouncement {
464 /// The node_announcement which should be sent.
465 msg: msgs::NodeAnnouncement,
467 /// Used to indicate that a channel_update should be broadcast to all peers.
468 BroadcastChannelUpdate {
469 /// The channel_update which should be sent.
470 msg: msgs::ChannelUpdate,
472 /// Used to indicate that a channel_update should be sent to a single peer.
473 /// In contrast to [`Self::BroadcastChannelUpdate`], this is used when the channel is a
474 /// private channel and we shouldn't be informing all of our peers of channel parameters.
476 /// The node_id of the node which should receive this message
478 /// The channel_update which should be sent.
479 msg: msgs::ChannelUpdate,
481 /// Broadcast an error downstream to be handled
483 /// The node_id of the node which should receive this message
485 /// The action which should be taken.
486 action: msgs::ErrorAction
488 /// When a payment fails we may receive updates back from the hop where it failed. In such
489 /// cases this event is generated so that we can inform the network graph of this information.
490 PaymentFailureNetworkUpdate {
491 /// The channel/node update which should be sent to NetGraphMsgHandler
492 update: msgs::HTLCFailChannelUpdate,
494 /// Query a peer for channels with funding transaction UTXOs in a block range.
495 SendChannelRangeQuery {
496 /// The node_id of this message recipient
498 /// The query_channel_range which should be sent.
499 msg: msgs::QueryChannelRange,
501 /// Request routing gossip messages from a peer for a list of channels identified by
502 /// their short_channel_ids.
504 /// The node_id of this message recipient
506 /// The query_short_channel_ids which should be sent.
507 msg: msgs::QueryShortChannelIds,
509 /// Sends a reply to a channel range query. This may be one of several SendReplyChannelRange events
510 /// emitted during processing of the query.
511 SendReplyChannelRange {
512 /// The node_id of this message recipient
514 /// The reply_channel_range which should be sent.
515 msg: msgs::ReplyChannelRange,
519 /// A trait indicating an object may generate message send events
520 pub trait MessageSendEventsProvider {
521 /// Gets the list of pending events which were generated by previous actions, clearing the list
523 fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
526 /// A trait indicating an object may generate events.
528 /// Events are processed by passing an [`EventHandler`] to [`process_pending_events`].
532 /// See [`process_pending_events`] for requirements around event processing.
534 /// When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
535 /// event since the last invocation. The handler must either act upon the event immediately
536 /// or preserve it for later handling.
538 /// Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
539 /// consult the provider's documentation on the implication of processing events and how a handler
540 /// may safely use the provider (e.g., see [`ChannelManager::process_pending_events`] and
541 /// [`ChainMonitor::process_pending_events`]).
543 /// (C-not implementable) As there is likely no reason for a user to implement this trait on their
546 /// [`process_pending_events`]: Self::process_pending_events
547 /// [`handle_event`]: EventHandler::handle_event
548 /// [`ChannelManager::process_pending_events`]: crate::ln::channelmanager::ChannelManager#method.process_pending_events
549 /// [`ChainMonitor::process_pending_events`]: crate::chain::chainmonitor::ChainMonitor#method.process_pending_events
550 pub trait EventsProvider {
551 /// Processes any events generated since the last call using the given event handler.
553 /// Subsequent calls must only process new events. However, handlers must be capable of handling
554 /// duplicate events across process restarts. This may occur if the provider was recovered from
555 /// an old state (i.e., it hadn't been successfully persisted after processing pending events).
556 fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler;
559 /// A trait implemented for objects handling events from [`EventsProvider`].
560 pub trait EventHandler {
561 /// Handles the given [`Event`].
563 /// See [`EventsProvider`] for details that must be considered when implementing this method.
564 fn handle_event(&self, event: Event);
567 impl<F> EventHandler for F where F: Fn(Event) {
568 fn handle_event(&self, event: Event) {