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;
24 use bitcoin::hashes::Hash;
25 use bitcoin::hashes::sha256::Hash as Sha256;
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 /// 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,
126 /// The hash which was given to [`ChannelManager::send_payment`].
128 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
129 payment_hash: PaymentHash,
131 /// Indicates an outbound payment we made failed. Probably some intermediary node dropped
132 /// something. You may wish to retry with a different route.
134 /// The hash which was given to ChannelManager::send_payment.
135 payment_hash: PaymentHash,
136 /// Indicates the payment was rejected for some reason by the recipient. This implies that
137 /// the payment has failed, not just the route in question. If this is not set, you may
138 /// retry the payment via a different route.
139 rejected_by_dest: bool,
140 /// Any failure information conveyed via the Onion return packet by a node along the failed
143 /// Should be applied to the [`NetworkGraph`] so that routing decisions can take into
144 /// account the update. [`NetGraphMsgHandler`] is capable of doing this.
146 /// [`NetworkGraph`]: crate::routing::network_graph::NetworkGraph
147 /// [`NetGraphMsgHandler`]: crate::routing::network_graph::NetGraphMsgHandler
148 network_update: Option<NetworkUpdate>,
149 /// For both single-path and multi-path payments, this is set if all paths of the payment have
150 /// failed. This will be set to false if (1) this is an MPP payment and (2) other parts of the
151 /// larger MPP payment were still in flight when this event was generated.
152 all_paths_failed: bool,
154 error_code: Option<u16>,
156 error_data: Option<Vec<u8>>,
158 /// Used to indicate that ChannelManager::process_pending_htlc_forwards should be called at a
159 /// time in the future.
160 PendingHTLCsForwardable {
161 /// The minimum amount of time that should be waited prior to calling
162 /// process_pending_htlc_forwards. To increase the effort required to correlate payments,
163 /// you should wait a random amount of time in roughly the range (now + time_forwardable,
164 /// now + 5*time_forwardable).
165 time_forwardable: Duration,
167 /// Used to indicate that an output which you should know how to spend was confirmed on chain
168 /// and is now spendable.
169 /// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
170 /// counterparty spending them due to some kind of timeout. Thus, you need to store them
171 /// somewhere and spend them when you create on-chain transactions.
173 /// The outputs which you should store as spendable by you.
174 outputs: Vec<SpendableOutputDescriptor>,
176 /// This event is generated when a payment has been successfully forwarded through us and a
177 /// forwarding fee earned.
179 /// The fee, in milli-satoshis, which was earned as a result of the payment.
181 /// Note that if we force-closed the channel over which we forwarded an HTLC while the HTLC
182 /// was pending, the amount the next hop claimed will have been rounded down to the nearest
183 /// whole satoshi. Thus, the fee calculated here may be higher than expected as we still
184 /// claimed the full value in millisatoshis from the source. In this case,
185 /// `claim_from_onchain_tx` will be set.
187 /// If the channel which sent us the payment has been force-closed, we will claim the funds
188 /// via an on-chain transaction. In that case we do not yet know the on-chain transaction
189 /// fees which we will spend and will instead set this to `None`. It is possible duplicate
190 /// `PaymentForwarded` events are generated for the same payment iff `fee_earned_msat` is
192 fee_earned_msat: Option<u64>,
193 /// If this is `true`, the forwarded HTLC was claimed by our counterparty via an on-chain
195 claim_from_onchain_tx: bool,
199 impl Writeable for Event {
200 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
202 &Event::FundingGenerationReady { .. } => {
204 // We never write out FundingGenerationReady events as, upon disconnection, peers
205 // drop any channels which have not yet exchanged funding_signed.
207 &Event::PaymentReceived { ref payment_hash, ref amt, ref purpose } => {
209 let mut payment_secret = None;
210 let mut user_payment_id = None;
211 let payment_preimage;
213 PaymentPurpose::InvoicePayment { payment_preimage: preimage, payment_secret: secret, user_payment_id: id } => {
214 payment_secret = Some(secret);
215 payment_preimage = *preimage;
216 user_payment_id = Some(id);
218 PaymentPurpose::SpontaneousPayment(preimage) => {
219 payment_preimage = Some(*preimage);
222 write_tlv_fields!(writer, {
223 (0, payment_hash, required),
224 (2, payment_secret, option),
226 (6, user_payment_id, option),
227 (8, payment_preimage, option),
230 &Event::PaymentSent { ref payment_preimage, ref payment_hash} => {
232 write_tlv_fields!(writer, {
233 (0, payment_preimage, required),
234 (1, payment_hash, required),
237 &Event::PaymentFailed { ref payment_hash, ref rejected_by_dest, ref network_update, ref all_paths_failed,
245 error_code.write(writer)?;
247 error_data.write(writer)?;
248 write_tlv_fields!(writer, {
249 (0, payment_hash, required),
250 (1, network_update, option),
251 (2, rejected_by_dest, required),
252 (3, all_paths_failed, required),
255 &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
257 write_tlv_fields!(writer, {});
258 // We don't write the time_fordwardable out at all, as we presume when the user
259 // deserializes us at least that much time has elapsed.
261 &Event::SpendableOutputs { ref outputs } => {
263 write_tlv_fields!(writer, {
264 (0, VecWriteWrapper(outputs), required),
267 &Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx } => {
269 write_tlv_fields!(writer, {
270 (0, fee_earned_msat, option),
271 (2, claim_from_onchain_tx, required),
278 impl MaybeReadable for Event {
279 fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
280 match Readable::read(reader)? {
284 let mut payment_hash = PaymentHash([0; 32]);
285 let mut payment_preimage = None;
286 let mut payment_secret = None;
288 let mut user_payment_id = None;
289 read_tlv_fields!(reader, {
290 (0, payment_hash, required),
291 (2, payment_secret, option),
293 (6, user_payment_id, option),
294 (8, payment_preimage, option),
296 let purpose = match payment_secret {
297 Some(secret) => PaymentPurpose::InvoicePayment {
299 payment_secret: secret,
300 user_payment_id: if let Some(id) = user_payment_id {
302 } else { return Err(msgs::DecodeError::InvalidValue) }
304 None if payment_preimage.is_some() => PaymentPurpose::SpontaneousPayment(payment_preimage.unwrap()),
305 None => return Err(msgs::DecodeError::InvalidValue),
307 Ok(Some(Event::PaymentReceived {
317 let mut payment_preimage = PaymentPreimage([0; 32]);
318 let mut payment_hash = None;
319 read_tlv_fields!(reader, {
320 (0, payment_preimage, required),
321 (1, payment_hash, option),
323 if payment_hash.is_none() {
324 payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()));
326 Ok(Some(Event::PaymentSent {
328 payment_hash: payment_hash.unwrap(),
336 let error_code = Readable::read(reader)?;
338 let error_data = Readable::read(reader)?;
339 let mut payment_hash = PaymentHash([0; 32]);
340 let mut rejected_by_dest = false;
341 let mut network_update = None;
342 let mut all_paths_failed = Some(true);
343 read_tlv_fields!(reader, {
344 (0, payment_hash, required),
345 (1, network_update, ignorable),
346 (2, rejected_by_dest, required),
347 (3, all_paths_failed, option),
349 Ok(Some(Event::PaymentFailed {
353 all_paths_failed: all_paths_failed.unwrap(),
364 read_tlv_fields!(reader, {});
365 Ok(Some(Event::PendingHTLCsForwardable {
366 time_forwardable: Duration::from_secs(0)
373 let mut outputs = VecReadWrapper(Vec::new());
374 read_tlv_fields!(reader, {
375 (0, outputs, required),
377 Ok(Some(Event::SpendableOutputs { outputs: outputs.0 }))
383 let mut fee_earned_msat = None;
384 let mut claim_from_onchain_tx = false;
385 read_tlv_fields!(reader, {
386 (0, fee_earned_msat, option),
387 (2, claim_from_onchain_tx, required),
389 Ok(Some(Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx }))
393 // Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue.
394 x if x % 2 == 1 => Ok(None),
395 _ => Err(msgs::DecodeError::InvalidValue)
400 /// An event generated by ChannelManager which indicates a message should be sent to a peer (or
401 /// broadcast to most peers).
402 /// These events are handled by PeerManager::process_events if you are using a PeerManager.
403 #[derive(Clone, Debug)]
404 pub enum MessageSendEvent {
405 /// Used to indicate that we've accepted a channel open and should send the accept_channel
406 /// message provided to the given peer.
408 /// The node_id of the node which should receive this message
410 /// The message which should be sent.
411 msg: msgs::AcceptChannel,
413 /// Used to indicate that we've initiated a channel open and should send the open_channel
414 /// message provided to the given peer.
416 /// The node_id of the node which should receive this message
418 /// The message which should be sent.
419 msg: msgs::OpenChannel,
421 /// Used to indicate that a funding_created message should be sent to the peer with the given node_id.
423 /// The node_id of the node which should receive this message
425 /// The message which should be sent.
426 msg: msgs::FundingCreated,
428 /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id.
430 /// The node_id of the node which should receive this message
432 /// The message which should be sent.
433 msg: msgs::FundingSigned,
435 /// Used to indicate that a funding_locked message should be sent to the peer with the given node_id.
437 /// The node_id of the node which should receive these message(s)
439 /// The funding_locked message which should be sent.
440 msg: msgs::FundingLocked,
442 /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
443 SendAnnouncementSignatures {
444 /// The node_id of the node which should receive these message(s)
446 /// The announcement_signatures message which should be sent.
447 msg: msgs::AnnouncementSignatures,
449 /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed
450 /// message should be sent to the peer with the given node_id.
452 /// The node_id of the node which should receive these message(s)
454 /// The update messages which should be sent. ALL messages in the struct should be sent!
455 updates: msgs::CommitmentUpdate,
457 /// Used to indicate that a revoke_and_ack message should be sent to the peer with the given node_id.
459 /// The node_id of the node which should receive this message
461 /// The message which should be sent.
462 msg: msgs::RevokeAndACK,
464 /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id.
466 /// The node_id of the node which should receive this message
468 /// The message which should be sent.
469 msg: msgs::ClosingSigned,
471 /// Used to indicate that a shutdown message should be sent to the peer with the given node_id.
473 /// The node_id of the node which should receive this message
475 /// The message which should be sent.
478 /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id.
479 SendChannelReestablish {
480 /// The node_id of the node which should receive this message
482 /// The message which should be sent.
483 msg: msgs::ChannelReestablish,
485 /// Used to indicate that a channel_announcement and channel_update should be broadcast to all
486 /// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
488 /// Note that after doing so, you very likely (unless you did so very recently) want to call
489 /// ChannelManager::broadcast_node_announcement to trigger a BroadcastNodeAnnouncement event.
490 /// This ensures that any nodes which see our channel_announcement also have a relevant
491 /// node_announcement, including relevant feature flags which may be important for routing
492 /// through or to us.
493 BroadcastChannelAnnouncement {
494 /// The channel_announcement which should be sent.
495 msg: msgs::ChannelAnnouncement,
496 /// The followup channel_update which should be sent.
497 update_msg: msgs::ChannelUpdate,
499 /// Used to indicate that a node_announcement should be broadcast to all peers.
500 BroadcastNodeAnnouncement {
501 /// The node_announcement which should be sent.
502 msg: msgs::NodeAnnouncement,
504 /// Used to indicate that a channel_update should be broadcast to all peers.
505 BroadcastChannelUpdate {
506 /// The channel_update which should be sent.
507 msg: msgs::ChannelUpdate,
509 /// Used to indicate that a channel_update should be sent to a single peer.
510 /// In contrast to [`Self::BroadcastChannelUpdate`], this is used when the channel is a
511 /// private channel and we shouldn't be informing all of our peers of channel parameters.
513 /// The node_id of the node which should receive this message
515 /// The channel_update which should be sent.
516 msg: msgs::ChannelUpdate,
518 /// Broadcast an error downstream to be handled
520 /// The node_id of the node which should receive this message
522 /// The action which should be taken.
523 action: msgs::ErrorAction
525 /// Query a peer for channels with funding transaction UTXOs in a block range.
526 SendChannelRangeQuery {
527 /// The node_id of this message recipient
529 /// The query_channel_range which should be sent.
530 msg: msgs::QueryChannelRange,
532 /// Request routing gossip messages from a peer for a list of channels identified by
533 /// their short_channel_ids.
535 /// The node_id of this message recipient
537 /// The query_short_channel_ids which should be sent.
538 msg: msgs::QueryShortChannelIds,
540 /// Sends a reply to a channel range query. This may be one of several SendReplyChannelRange events
541 /// emitted during processing of the query.
542 SendReplyChannelRange {
543 /// The node_id of this message recipient
545 /// The reply_channel_range which should be sent.
546 msg: msgs::ReplyChannelRange,
550 /// A trait indicating an object may generate message send events
551 pub trait MessageSendEventsProvider {
552 /// Gets the list of pending events which were generated by previous actions, clearing the list
554 fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
557 /// A trait indicating an object may generate events.
559 /// Events are processed by passing an [`EventHandler`] to [`process_pending_events`].
563 /// See [`process_pending_events`] for requirements around event processing.
565 /// When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
566 /// event since the last invocation. The handler must either act upon the event immediately
567 /// or preserve it for later handling.
569 /// Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
570 /// consult the provider's documentation on the implication of processing events and how a handler
571 /// may safely use the provider (e.g., see [`ChannelManager::process_pending_events`] and
572 /// [`ChainMonitor::process_pending_events`]).
574 /// (C-not implementable) As there is likely no reason for a user to implement this trait on their
577 /// [`process_pending_events`]: Self::process_pending_events
578 /// [`handle_event`]: EventHandler::handle_event
579 /// [`ChannelManager::process_pending_events`]: crate::ln::channelmanager::ChannelManager#method.process_pending_events
580 /// [`ChainMonitor::process_pending_events`]: crate::chain::chainmonitor::ChainMonitor#method.process_pending_events
581 pub trait EventsProvider {
582 /// Processes any events generated since the last call using the given event handler.
584 /// Subsequent calls must only process new events. However, handlers must be capable of handling
585 /// duplicate events across process restarts. This may occur if the provider was recovered from
586 /// an old state (i.e., it hadn't been successfully persisted after processing pending events).
587 fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler;
590 /// A trait implemented for objects handling events from [`EventsProvider`].
591 pub trait EventHandler {
592 /// Handles the given [`Event`].
594 /// See [`EventsProvider`] for details that must be considered when implementing this method.
595 fn handle_event(&self, event: &Event);
598 impl<F> EventHandler for F where F: Fn(&Event) {
599 fn handle_event(&self, event: &Event) {