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;
27 use core::time::Duration;
30 /// Some information provided on receipt of payment depends on whether the payment received is a
31 /// spontaneous payment or a "conventional" lightning payment that's paying an invoice.
32 #[derive(Clone, Debug)]
33 pub enum PaymentPurpose {
34 /// Information for receiving a payment that we generated an invoice for.
36 /// The preimage to the payment_hash, if the payment hash (and secret) were fetched via
37 /// [`ChannelManager::create_inbound_payment`]. If provided, this can be handed directly to
38 /// [`ChannelManager::claim_funds`].
40 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
41 /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
42 payment_preimage: Option<PaymentPreimage>,
43 /// The "payment secret". This authenticates the sender to the recipient, preventing a
44 /// number of deanonymization attacks during the routing process.
45 /// It is provided here for your reference, however its accuracy is enforced directly by
46 /// [`ChannelManager`] using the values you previously provided to
47 /// [`ChannelManager::create_inbound_payment`] or
48 /// [`ChannelManager::create_inbound_payment_for_hash`].
50 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
51 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
52 /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
53 payment_secret: PaymentSecret,
54 /// This is the `user_payment_id` which was provided to
55 /// [`ChannelManager::create_inbound_payment_for_hash`] or
56 /// [`ChannelManager::create_inbound_payment`]. It has no meaning inside of LDK and is
57 /// simply copied here. It may be used to correlate PaymentReceived events with invoice
58 /// metadata stored elsewhere.
60 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
61 /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
64 /// Because this is a spontaneous payment, the payer generated their own preimage rather than us
65 /// (the payee) providing a preimage.
66 SpontaneousPayment(PaymentPreimage),
69 /// An Event which you should probably take some action in response to.
71 /// Note that while Writeable and Readable are implemented for Event, you probably shouldn't use
72 /// them directly as they don't round-trip exactly (for example FundingGenerationReady is never
73 /// written as it makes no sense to respond to it after reconnecting to peers).
74 #[derive(Clone, Debug)]
76 /// Used to indicate that the client should generate a funding transaction with the given
77 /// parameters and then call ChannelManager::funding_transaction_generated.
78 /// Generated in ChannelManager message handling.
79 /// Note that *all inputs* in the funding transaction must spend SegWit outputs or your
80 /// counterparty can steal your funds!
81 FundingGenerationReady {
82 /// The random channel_id we picked which you'll need to pass into
83 /// ChannelManager::funding_transaction_generated.
84 temporary_channel_id: [u8; 32],
85 /// The value, in satoshis, that the output should have.
86 channel_value_satoshis: u64,
87 /// The script which should be used in the transaction output.
88 output_script: Script,
89 /// The value passed in to ChannelManager::create_channel
92 /// Indicates we've received money! Just gotta dig out that payment preimage and feed it to
93 /// ChannelManager::claim_funds to get it....
94 /// Note that if the preimage is not known or the amount paid is incorrect, you should call
95 /// ChannelManager::fail_htlc_backwards to free up resources for this HTLC and avoid
96 /// network congestion.
97 /// The amount paid should be considered 'incorrect' when it is less than or more than twice
98 /// the amount expected.
99 /// If you fail to call either ChannelManager::claim_funds or
100 /// ChannelManager::fail_htlc_backwards within the HTLC's timeout, the HTLC will be
101 /// automatically failed.
103 /// The hash for which the preimage should be handed to the ChannelManager.
104 payment_hash: PaymentHash,
105 /// The value, in thousandths of a satoshi, that this payment is for. Note that you must
106 /// compare this to the expected value before accepting the payment (as otherwise you are
107 /// providing proof-of-payment for less than the value you expected!).
109 /// Information for claiming this received payment, based on whether the purpose of the
110 /// payment is to pay an invoice or to send a spontaneous payment.
111 purpose: PaymentPurpose,
113 /// Indicates an outbound payment we made succeeded (ie it made it all the way to its target
114 /// and we got back the payment preimage for it).
116 /// The preimage to the hash given to ChannelManager::send_payment.
117 /// Note that this serves as a payment receipt, if you wish to have such a thing, you must
118 /// store it somehow!
119 payment_preimage: PaymentPreimage,
121 /// Indicates an outbound payment we made failed. Probably some intermediary node dropped
122 /// something. You may wish to retry with a different route.
124 /// The hash which was given to ChannelManager::send_payment.
125 payment_hash: PaymentHash,
126 /// Indicates the payment was rejected for some reason by the recipient. This implies that
127 /// the payment has failed, not just the route in question. If this is not set, you may
128 /// retry the payment via a different route.
129 rejected_by_dest: bool,
131 error_code: Option<u16>,
133 error_data: Option<Vec<u8>>,
135 /// Used to indicate that ChannelManager::process_pending_htlc_forwards should be called at a
136 /// time in the future.
137 PendingHTLCsForwardable {
138 /// The minimum amount of time that should be waited prior to calling
139 /// process_pending_htlc_forwards. To increase the effort required to correlate payments,
140 /// you should wait a random amount of time in roughly the range (now + time_forwardable,
141 /// now + 5*time_forwardable).
142 time_forwardable: Duration,
144 /// Used to indicate that an output which you should know how to spend was confirmed on chain
145 /// and is now spendable.
146 /// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
147 /// counterparty spending them due to some kind of timeout. Thus, you need to store them
148 /// somewhere and spend them when you create on-chain transactions.
150 /// The outputs which you should store as spendable by you.
151 outputs: Vec<SpendableOutputDescriptor>,
153 /// This event is generated when a payment has been successfully forwarded through us and a
154 /// forwarding fee earned.
156 /// The fee, in milli-satoshis, which was earned as a result of the payment.
158 /// Note that if we force-closed the channel over which we forwarded an HTLC while the HTLC
159 /// was pending, the amount the next hop claimed will have been rounded down to the nearest
160 /// whole satoshi. Thus, the fee calculated here may be higher than expected as we still
161 /// claimed the full value in millisatoshis from the source. In this case,
162 /// `claim_from_onchain_tx` will be set.
164 /// If the channel which sent us the payment has been force-closed, we will claim the funds
165 /// via an on-chain transaction. In that case we do not yet know the on-chain transaction
166 /// fees which we will spend and will instead set this to `None`. It is possible duplicate
167 /// `PaymentForwarded` events are generated for the same payment iff `fee_earned_msat` is
169 fee_earned_msat: Option<u64>,
170 /// If this is `true`, the forwarded HTLC was claimed by our counterparty via an on-chain
172 claim_from_onchain_tx: bool,
176 impl Writeable for Event {
177 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
179 &Event::FundingGenerationReady { .. } => {
181 // We never write out FundingGenerationReady events as, upon disconnection, peers
182 // drop any channels which have not yet exchanged funding_signed.
184 &Event::PaymentReceived { ref payment_hash, ref amt, ref purpose } => {
186 let mut payment_secret = None;
187 let mut user_payment_id = None;
188 let payment_preimage;
190 PaymentPurpose::InvoicePayment { payment_preimage: preimage, payment_secret: secret, user_payment_id: id } => {
191 payment_secret = Some(secret);
192 payment_preimage = *preimage;
193 user_payment_id = Some(id);
195 PaymentPurpose::SpontaneousPayment(preimage) => {
196 payment_preimage = Some(*preimage);
199 write_tlv_fields!(writer, {
200 (0, payment_hash, required),
201 (2, payment_secret, option),
203 (6, user_payment_id, option),
204 (8, payment_preimage, option),
207 &Event::PaymentSent { ref payment_preimage } => {
209 write_tlv_fields!(writer, {
210 (0, payment_preimage, required),
213 &Event::PaymentFailed { ref payment_hash, ref rejected_by_dest,
221 error_code.write(writer)?;
223 error_data.write(writer)?;
224 write_tlv_fields!(writer, {
225 (0, payment_hash, required),
226 (2, rejected_by_dest, required),
229 &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
231 write_tlv_fields!(writer, {});
232 // We don't write the time_fordwardable out at all, as we presume when the user
233 // deserializes us at least that much time has elapsed.
235 &Event::SpendableOutputs { ref outputs } => {
237 write_tlv_fields!(writer, {
238 (0, VecWriteWrapper(outputs), required),
241 &Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx } => {
243 write_tlv_fields!(writer, {
244 (0, fee_earned_msat, option),
245 (2, claim_from_onchain_tx, required),
252 impl MaybeReadable for Event {
253 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
254 match Readable::read(reader)? {
258 let mut payment_hash = PaymentHash([0; 32]);
259 let mut payment_preimage = None;
260 let mut payment_secret = None;
262 let mut user_payment_id = None;
263 read_tlv_fields!(reader, {
264 (0, payment_hash, required),
265 (2, payment_secret, option),
267 (6, user_payment_id, option),
268 (8, payment_preimage, option),
270 let purpose = match payment_secret {
271 Some(secret) => PaymentPurpose::InvoicePayment {
273 payment_secret: secret,
274 user_payment_id: if let Some(id) = user_payment_id {
276 } else { return Err(msgs::DecodeError::InvalidValue) }
278 None if payment_preimage.is_some() => PaymentPurpose::SpontaneousPayment(payment_preimage.unwrap()),
279 None => return Err(msgs::DecodeError::InvalidValue),
281 Ok(Some(Event::PaymentReceived {
291 let mut payment_preimage = PaymentPreimage([0; 32]);
292 read_tlv_fields!(reader, {
293 (0, payment_preimage, required),
295 Ok(Some(Event::PaymentSent {
304 let error_code = Readable::read(reader)?;
306 let error_data = Readable::read(reader)?;
307 let mut payment_hash = PaymentHash([0; 32]);
308 let mut rejected_by_dest = false;
309 read_tlv_fields!(reader, {
310 (0, payment_hash, required),
311 (2, rejected_by_dest, required),
313 Ok(Some(Event::PaymentFailed {
326 read_tlv_fields!(reader, {});
327 Ok(Some(Event::PendingHTLCsForwardable {
328 time_forwardable: Duration::from_secs(0)
335 let mut outputs = VecReadWrapper(Vec::new());
336 read_tlv_fields!(reader, {
337 (0, outputs, required),
339 Ok(Some(Event::SpendableOutputs { outputs: outputs.0 }))
345 let mut fee_earned_msat = None;
346 let mut claim_from_onchain_tx = false;
347 read_tlv_fields!(reader, {
348 (0, fee_earned_msat, option),
349 (2, claim_from_onchain_tx, required),
351 Ok(Some(Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx }))
355 // Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue.
356 x if x % 2 == 1 => Ok(None),
357 _ => Err(msgs::DecodeError::InvalidValue)
362 /// An event generated by ChannelManager which indicates a message should be sent to a peer (or
363 /// broadcast to most peers).
364 /// These events are handled by PeerManager::process_events if you are using a PeerManager.
365 #[derive(Clone, Debug)]
366 pub enum MessageSendEvent {
367 /// Used to indicate that we've accepted a channel open and should send the accept_channel
368 /// message provided to the given peer.
370 /// The node_id of the node which should receive this message
372 /// The message which should be sent.
373 msg: msgs::AcceptChannel,
375 /// Used to indicate that we've initiated a channel open and should send the open_channel
376 /// message provided to the given peer.
378 /// The node_id of the node which should receive this message
380 /// The message which should be sent.
381 msg: msgs::OpenChannel,
383 /// Used to indicate that a funding_created message should be sent to the peer with the given node_id.
385 /// The node_id of the node which should receive this message
387 /// The message which should be sent.
388 msg: msgs::FundingCreated,
390 /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id.
392 /// The node_id of the node which should receive this message
394 /// The message which should be sent.
395 msg: msgs::FundingSigned,
397 /// Used to indicate that a funding_locked message should be sent to the peer with the given node_id.
399 /// The node_id of the node which should receive these message(s)
401 /// The funding_locked message which should be sent.
402 msg: msgs::FundingLocked,
404 /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
405 SendAnnouncementSignatures {
406 /// The node_id of the node which should receive these message(s)
408 /// The announcement_signatures message which should be sent.
409 msg: msgs::AnnouncementSignatures,
411 /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed
412 /// message should be sent to the peer with the given node_id.
414 /// The node_id of the node which should receive these message(s)
416 /// The update messages which should be sent. ALL messages in the struct should be sent!
417 updates: msgs::CommitmentUpdate,
419 /// Used to indicate that a revoke_and_ack message should be sent to the peer with the given node_id.
421 /// The node_id of the node which should receive this message
423 /// The message which should be sent.
424 msg: msgs::RevokeAndACK,
426 /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id.
428 /// The node_id of the node which should receive this message
430 /// The message which should be sent.
431 msg: msgs::ClosingSigned,
433 /// Used to indicate that a shutdown message should be sent to the peer with the given node_id.
435 /// The node_id of the node which should receive this message
437 /// The message which should be sent.
440 /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id.
441 SendChannelReestablish {
442 /// The node_id of the node which should receive this message
444 /// The message which should be sent.
445 msg: msgs::ChannelReestablish,
447 /// Used to indicate that a channel_announcement and channel_update should be broadcast to all
448 /// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
450 /// Note that after doing so, you very likely (unless you did so very recently) want to call
451 /// ChannelManager::broadcast_node_announcement to trigger a BroadcastNodeAnnouncement event.
452 /// This ensures that any nodes which see our channel_announcement also have a relevant
453 /// node_announcement, including relevant feature flags which may be important for routing
454 /// through or to us.
455 BroadcastChannelAnnouncement {
456 /// The channel_announcement which should be sent.
457 msg: msgs::ChannelAnnouncement,
458 /// The followup channel_update which should be sent.
459 update_msg: msgs::ChannelUpdate,
461 /// Used to indicate that a node_announcement should be broadcast to all peers.
462 BroadcastNodeAnnouncement {
463 /// The node_announcement which should be sent.
464 msg: msgs::NodeAnnouncement,
466 /// Used to indicate that a channel_update should be broadcast to all peers.
467 BroadcastChannelUpdate {
468 /// The channel_update which should be sent.
469 msg: msgs::ChannelUpdate,
471 /// Used to indicate that a channel_update should be sent to a single peer.
472 /// In contrast to [`Self::BroadcastChannelUpdate`], this is used when the channel is a
473 /// private channel and we shouldn't be informing all of our peers of channel parameters.
475 /// The node_id of the node which should receive this message
477 /// The channel_update which should be sent.
478 msg: msgs::ChannelUpdate,
480 /// Broadcast an error downstream to be handled
482 /// The node_id of the node which should receive this message
484 /// The action which should be taken.
485 action: msgs::ErrorAction
487 /// When a payment fails we may receive updates back from the hop where it failed. In such
488 /// cases this event is generated so that we can inform the network graph of this information.
489 PaymentFailureNetworkUpdate {
490 /// The channel/node update which should be sent to NetGraphMsgHandler
491 update: msgs::HTLCFailChannelUpdate,
493 /// Query a peer for channels with funding transaction UTXOs in a block range.
494 SendChannelRangeQuery {
495 /// The node_id of this message recipient
497 /// The query_channel_range which should be sent.
498 msg: msgs::QueryChannelRange,
500 /// Request routing gossip messages from a peer for a list of channels identified by
501 /// their short_channel_ids.
503 /// The node_id of this message recipient
505 /// The query_short_channel_ids which should be sent.
506 msg: msgs::QueryShortChannelIds,
508 /// Sends a reply to a channel range query. This may be one of several SendReplyChannelRange events
509 /// emitted during processing of the query.
510 SendReplyChannelRange {
511 /// The node_id of this message recipient
513 /// The reply_channel_range which should be sent.
514 msg: msgs::ReplyChannelRange,
518 /// A trait indicating an object may generate message send events
519 pub trait MessageSendEventsProvider {
520 /// Gets the list of pending events which were generated by previous actions, clearing the list
522 fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
525 /// A trait indicating an object may generate events.
527 /// Events are processed by passing an [`EventHandler`] to [`process_pending_events`].
531 /// See [`process_pending_events`] for requirements around event processing.
533 /// When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
534 /// event since the last invocation. The handler must either act upon the event immediately
535 /// or preserve it for later handling.
537 /// Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
538 /// consult the provider's documentation on the implication of processing events and how a handler
539 /// may safely use the provider (e.g., see [`ChannelManager::process_pending_events`] and
540 /// [`ChainMonitor::process_pending_events`]).
542 /// (C-not implementable) As there is likely no reason for a user to implement this trait on their
545 /// [`process_pending_events`]: Self::process_pending_events
546 /// [`handle_event`]: EventHandler::handle_event
547 /// [`ChannelManager::process_pending_events`]: crate::ln::channelmanager::ChannelManager#method.process_pending_events
548 /// [`ChainMonitor::process_pending_events`]: crate::chain::chainmonitor::ChainMonitor#method.process_pending_events
549 pub trait EventsProvider {
550 /// Processes any events generated since the last call using the given event handler.
552 /// Subsequent calls must only process new events. However, handlers must be capable of handling
553 /// duplicate events across process restarts. This may occur if the provider was recovered from
554 /// an old state (i.e., it hadn't been successfully persisted after processing pending events).
555 fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler;
558 /// A trait implemented for objects handling events from [`EventsProvider`].
559 pub trait EventHandler {
560 /// Handles the given [`Event`].
562 /// See [`EventsProvider`] for details that must be considered when implementing this method.
563 fn handle_event(&self, event: Event);
566 impl<F> EventHandler for F where F: Fn(Event) {
567 fn handle_event(&self, event: Event) {