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)]
73 /// Some information provided on the closure source of the channel halting.
74 pub enum ClosureReason {
75 /// Closure generated from receiving a peer error message by ChannelManager::handle_error
76 CounterpartyForceClosed {
77 /// The error is coming from the peer, there *might* be a human-readable msg
78 peer_msg: Option<String>,
80 /// Closure generated from ChannelManager::force_close_channel
82 /// Closure generated from receiving a peer's ClosingSigned message. Note the shutdown
83 /// sequence might have been initially initiated by us.
85 /// Closure generated from receiving chain::Watch's CommitmentTxBroadcast event.
86 CommitmentTxBroadcasted,
87 /// Closure generated from processing an event, likely a HTLC forward/relay/reception.
91 /// Closure generated from ChannelManager::peer_disconnected.
95 impl_writeable_tlv_based_enum_upgradable!(ClosureReason,
96 (0, CounterpartyForceClosed) => { (1, peer_msg, option) },
97 (2, HolderForceClosed) => {},
98 (6, CommitmentTxBroadcasted) => {},
99 (4, CooperativeClosure) => {},
100 (8, ProcessingError) => { (1, err, required) },
101 (10, DisconnectedPeer) => {},
104 /// An Event which you should probably take some action in response to.
106 /// Note that while Writeable and Readable are implemented for Event, you probably shouldn't use
107 /// them directly as they don't round-trip exactly (for example FundingGenerationReady is never
108 /// written as it makes no sense to respond to it after reconnecting to peers).
109 #[derive(Clone, Debug)]
111 /// Used to indicate that the client should generate a funding transaction with the given
112 /// parameters and then call ChannelManager::funding_transaction_generated.
113 /// Generated in ChannelManager message handling.
114 /// Note that *all inputs* in the funding transaction must spend SegWit outputs or your
115 /// counterparty can steal your funds!
116 FundingGenerationReady {
117 /// The random channel_id we picked which you'll need to pass into
118 /// ChannelManager::funding_transaction_generated.
119 temporary_channel_id: [u8; 32],
120 /// The value, in satoshis, that the output should have.
121 channel_value_satoshis: u64,
122 /// The script which should be used in the transaction output.
123 output_script: Script,
124 /// The value passed in to ChannelManager::create_channel
125 user_channel_id: u64,
127 /// Indicates we've received money! Just gotta dig out that payment preimage and feed it to
128 /// ChannelManager::claim_funds to get it....
129 /// Note that if the preimage is not known or the amount paid is incorrect, you should call
130 /// ChannelManager::fail_htlc_backwards to free up resources for this HTLC and avoid
131 /// network congestion.
132 /// The amount paid should be considered 'incorrect' when it is less than or more than twice
133 /// the amount expected.
134 /// If you fail to call either ChannelManager::claim_funds or
135 /// ChannelManager::fail_htlc_backwards within the HTLC's timeout, the HTLC will be
136 /// automatically failed.
138 /// The hash for which the preimage should be handed to the ChannelManager.
139 payment_hash: PaymentHash,
140 /// The value, in thousandths of a satoshi, that this payment is for. Note that you must
141 /// compare this to the expected value before accepting the payment (as otherwise you are
142 /// providing proof-of-payment for less than the value you expected!).
144 /// Information for claiming this received payment, based on whether the purpose of the
145 /// payment is to pay an invoice or to send a spontaneous payment.
146 purpose: PaymentPurpose,
148 /// Indicates an outbound payment we made succeeded (i.e. it made it all the way to its target
149 /// and we got back the payment preimage for it).
151 /// Note for MPP payments: in rare cases, this event may be preceded by a `PaymentFailed` event.
152 /// In this situation, you SHOULD treat this payment as having succeeded.
154 /// The preimage to the hash given to ChannelManager::send_payment.
155 /// Note that this serves as a payment receipt, if you wish to have such a thing, you must
156 /// store it somehow!
157 payment_preimage: PaymentPreimage,
159 /// Indicates an outbound payment we made failed. Probably some intermediary node dropped
160 /// something. You may wish to retry with a different route.
162 /// The hash which was given to ChannelManager::send_payment.
163 payment_hash: PaymentHash,
164 /// Indicates the payment was rejected for some reason by the recipient. This implies that
165 /// the payment has failed, not just the route in question. If this is not set, you may
166 /// retry the payment via a different route.
167 rejected_by_dest: bool,
168 /// Any failure information conveyed via the Onion return packet by a node along the failed
171 /// Should be applied to the [`NetworkGraph`] so that routing decisions can take into
172 /// account the update. [`NetGraphMsgHandler`] is capable of doing this.
174 /// [`NetworkGraph`]: crate::routing::network_graph::NetworkGraph
175 /// [`NetGraphMsgHandler`]: crate::routing::network_graph::NetGraphMsgHandler
176 network_update: Option<NetworkUpdate>,
177 /// For both single-path and multi-path payments, this is set if all paths of the payment have
178 /// failed. This will be set to false if (1) this is an MPP payment and (2) other parts of the
179 /// larger MPP payment were still in flight when this event was generated.
180 all_paths_failed: bool,
182 error_code: Option<u16>,
184 error_data: Option<Vec<u8>>,
186 /// Used to indicate that ChannelManager::process_pending_htlc_forwards should be called at a
187 /// time in the future.
188 PendingHTLCsForwardable {
189 /// The minimum amount of time that should be waited prior to calling
190 /// process_pending_htlc_forwards. To increase the effort required to correlate payments,
191 /// you should wait a random amount of time in roughly the range (now + time_forwardable,
192 /// now + 5*time_forwardable).
193 time_forwardable: Duration,
195 /// Used to indicate that an output which you should know how to spend was confirmed on chain
196 /// and is now spendable.
197 /// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
198 /// counterparty spending them due to some kind of timeout. Thus, you need to store them
199 /// somewhere and spend them when you create on-chain transactions.
201 /// The outputs which you should store as spendable by you.
202 outputs: Vec<SpendableOutputDescriptor>,
204 /// This event is generated when a payment has been successfully forwarded through us and a
205 /// forwarding fee earned.
207 /// The fee, in milli-satoshis, which was earned as a result of the payment.
209 /// Note that if we force-closed the channel over which we forwarded an HTLC while the HTLC
210 /// was pending, the amount the next hop claimed will have been rounded down to the nearest
211 /// whole satoshi. Thus, the fee calculated here may be higher than expected as we still
212 /// claimed the full value in millisatoshis from the source. In this case,
213 /// `claim_from_onchain_tx` will be set.
215 /// If the channel which sent us the payment has been force-closed, we will claim the funds
216 /// via an on-chain transaction. In that case we do not yet know the on-chain transaction
217 /// fees which we will spend and will instead set this to `None`. It is possible duplicate
218 /// `PaymentForwarded` events are generated for the same payment iff `fee_earned_msat` is
220 fee_earned_msat: Option<u64>,
221 /// If this is `true`, the forwarded HTLC was claimed by our counterparty via an on-chain
223 claim_from_onchain_tx: bool,
225 /// Used to indicate that a channel with the given `channel_id` is in the process of closure.
227 /// The channel_id which has been barren from further off-chain updates but
228 /// funding output might still be not resolved yet.
229 channel_id: [u8; 32],
230 /// A machine-readable error message
235 impl Writeable for Event {
236 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
238 &Event::FundingGenerationReady { .. } => {
240 // We never write out FundingGenerationReady events as, upon disconnection, peers
241 // drop any channels which have not yet exchanged funding_signed.
243 &Event::PaymentReceived { ref payment_hash, ref amt, ref purpose } => {
245 let mut payment_secret = None;
246 let mut user_payment_id = None;
247 let payment_preimage;
249 PaymentPurpose::InvoicePayment { payment_preimage: preimage, payment_secret: secret, user_payment_id: id } => {
250 payment_secret = Some(secret);
251 payment_preimage = *preimage;
252 user_payment_id = Some(id);
254 PaymentPurpose::SpontaneousPayment(preimage) => {
255 payment_preimage = Some(*preimage);
258 write_tlv_fields!(writer, {
259 (0, payment_hash, required),
260 (2, payment_secret, option),
262 (6, user_payment_id, option),
263 (8, payment_preimage, option),
266 &Event::PaymentSent { ref payment_preimage } => {
268 write_tlv_fields!(writer, {
269 (0, payment_preimage, required),
272 &Event::PaymentFailed { ref payment_hash, ref rejected_by_dest, ref network_update, ref all_paths_failed,
280 error_code.write(writer)?;
282 error_data.write(writer)?;
283 write_tlv_fields!(writer, {
284 (0, payment_hash, required),
285 (1, network_update, option),
286 (2, rejected_by_dest, required),
287 (3, all_paths_failed, required),
290 &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
292 write_tlv_fields!(writer, {});
293 // We don't write the time_fordwardable out at all, as we presume when the user
294 // deserializes us at least that much time has elapsed.
296 &Event::SpendableOutputs { ref outputs } => {
298 write_tlv_fields!(writer, {
299 (0, VecWriteWrapper(outputs), required),
302 &Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx } => {
304 write_tlv_fields!(writer, {
305 (0, fee_earned_msat, option),
306 (2, claim_from_onchain_tx, required),
309 &Event::ChannelClosed { ref channel_id, ref err } => {
311 channel_id.write(writer)?;
313 write_tlv_fields!(writer, {});
319 impl MaybeReadable for Event {
320 fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
321 match Readable::read(reader)? {
325 let mut payment_hash = PaymentHash([0; 32]);
326 let mut payment_preimage = None;
327 let mut payment_secret = None;
329 let mut user_payment_id = None;
330 read_tlv_fields!(reader, {
331 (0, payment_hash, required),
332 (2, payment_secret, option),
334 (6, user_payment_id, option),
335 (8, payment_preimage, option),
337 let purpose = match payment_secret {
338 Some(secret) => PaymentPurpose::InvoicePayment {
340 payment_secret: secret,
341 user_payment_id: if let Some(id) = user_payment_id {
343 } else { return Err(msgs::DecodeError::InvalidValue) }
345 None if payment_preimage.is_some() => PaymentPurpose::SpontaneousPayment(payment_preimage.unwrap()),
346 None => return Err(msgs::DecodeError::InvalidValue),
348 Ok(Some(Event::PaymentReceived {
358 let mut payment_preimage = PaymentPreimage([0; 32]);
359 read_tlv_fields!(reader, {
360 (0, payment_preimage, required),
362 Ok(Some(Event::PaymentSent {
371 let error_code = Readable::read(reader)?;
373 let error_data = Readable::read(reader)?;
374 let mut payment_hash = PaymentHash([0; 32]);
375 let mut rejected_by_dest = false;
376 let mut network_update = None;
377 let mut all_paths_failed = Some(true);
378 read_tlv_fields!(reader, {
379 (0, payment_hash, required),
380 (1, network_update, ignorable),
381 (2, rejected_by_dest, required),
382 (3, all_paths_failed, option),
384 Ok(Some(Event::PaymentFailed {
388 all_paths_failed: all_paths_failed.unwrap(),
399 read_tlv_fields!(reader, {});
400 Ok(Some(Event::PendingHTLCsForwardable {
401 time_forwardable: Duration::from_secs(0)
408 let mut outputs = VecReadWrapper(Vec::new());
409 read_tlv_fields!(reader, {
410 (0, outputs, required),
412 Ok(Some(Event::SpendableOutputs { outputs: outputs.0 }))
418 let mut fee_earned_msat = None;
419 let mut claim_from_onchain_tx = false;
420 read_tlv_fields!(reader, {
421 (0, fee_earned_msat, option),
422 (2, claim_from_onchain_tx, required),
424 Ok(Some(Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx }))
429 let channel_id = Readable::read(reader)?;
430 let err = MaybeReadable::read(reader)?;
431 read_tlv_fields!(reader, {});
432 if err.is_none() { return Ok(None); }
433 Ok(Some(Event::ChannelClosed { channel_id, err: err.unwrap() }))
435 // Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue.
436 x if x % 2 == 1 => Ok(None),
437 _ => Err(msgs::DecodeError::InvalidValue)
442 /// An event generated by ChannelManager which indicates a message should be sent to a peer (or
443 /// broadcast to most peers).
444 /// These events are handled by PeerManager::process_events if you are using a PeerManager.
445 #[derive(Clone, Debug)]
446 pub enum MessageSendEvent {
447 /// Used to indicate that we've accepted a channel open and should send the accept_channel
448 /// message provided to the given peer.
450 /// The node_id of the node which should receive this message
452 /// The message which should be sent.
453 msg: msgs::AcceptChannel,
455 /// Used to indicate that we've initiated a channel open and should send the open_channel
456 /// message provided to the given peer.
458 /// The node_id of the node which should receive this message
460 /// The message which should be sent.
461 msg: msgs::OpenChannel,
463 /// Used to indicate that a funding_created message should be sent to the peer with the given node_id.
465 /// The node_id of the node which should receive this message
467 /// The message which should be sent.
468 msg: msgs::FundingCreated,
470 /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id.
472 /// The node_id of the node which should receive this message
474 /// The message which should be sent.
475 msg: msgs::FundingSigned,
477 /// Used to indicate that a funding_locked message should be sent to the peer with the given node_id.
479 /// The node_id of the node which should receive these message(s)
481 /// The funding_locked message which should be sent.
482 msg: msgs::FundingLocked,
484 /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
485 SendAnnouncementSignatures {
486 /// The node_id of the node which should receive these message(s)
488 /// The announcement_signatures message which should be sent.
489 msg: msgs::AnnouncementSignatures,
491 /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed
492 /// message should be sent to the peer with the given node_id.
494 /// The node_id of the node which should receive these message(s)
496 /// The update messages which should be sent. ALL messages in the struct should be sent!
497 updates: msgs::CommitmentUpdate,
499 /// Used to indicate that a revoke_and_ack message should be sent to the peer with the given node_id.
501 /// The node_id of the node which should receive this message
503 /// The message which should be sent.
504 msg: msgs::RevokeAndACK,
506 /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id.
508 /// The node_id of the node which should receive this message
510 /// The message which should be sent.
511 msg: msgs::ClosingSigned,
513 /// Used to indicate that a shutdown message should be sent to the peer with the given node_id.
515 /// The node_id of the node which should receive this message
517 /// The message which should be sent.
520 /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id.
521 SendChannelReestablish {
522 /// The node_id of the node which should receive this message
524 /// The message which should be sent.
525 msg: msgs::ChannelReestablish,
527 /// Used to indicate that a channel_announcement and channel_update should be broadcast to all
528 /// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
530 /// Note that after doing so, you very likely (unless you did so very recently) want to call
531 /// ChannelManager::broadcast_node_announcement to trigger a BroadcastNodeAnnouncement event.
532 /// This ensures that any nodes which see our channel_announcement also have a relevant
533 /// node_announcement, including relevant feature flags which may be important for routing
534 /// through or to us.
535 BroadcastChannelAnnouncement {
536 /// The channel_announcement which should be sent.
537 msg: msgs::ChannelAnnouncement,
538 /// The followup channel_update which should be sent.
539 update_msg: msgs::ChannelUpdate,
541 /// Used to indicate that a node_announcement should be broadcast to all peers.
542 BroadcastNodeAnnouncement {
543 /// The node_announcement which should be sent.
544 msg: msgs::NodeAnnouncement,
546 /// Used to indicate that a channel_update should be broadcast to all peers.
547 BroadcastChannelUpdate {
548 /// The channel_update which should be sent.
549 msg: msgs::ChannelUpdate,
551 /// Used to indicate that a channel_update should be sent to a single peer.
552 /// In contrast to [`Self::BroadcastChannelUpdate`], this is used when the channel is a
553 /// private channel and we shouldn't be informing all of our peers of channel parameters.
555 /// The node_id of the node which should receive this message
557 /// The channel_update which should be sent.
558 msg: msgs::ChannelUpdate,
560 /// Broadcast an error downstream to be handled
562 /// The node_id of the node which should receive this message
564 /// The action which should be taken.
565 action: msgs::ErrorAction
567 /// Query a peer for channels with funding transaction UTXOs in a block range.
568 SendChannelRangeQuery {
569 /// The node_id of this message recipient
571 /// The query_channel_range which should be sent.
572 msg: msgs::QueryChannelRange,
574 /// Request routing gossip messages from a peer for a list of channels identified by
575 /// their short_channel_ids.
577 /// The node_id of this message recipient
579 /// The query_short_channel_ids which should be sent.
580 msg: msgs::QueryShortChannelIds,
582 /// Sends a reply to a channel range query. This may be one of several SendReplyChannelRange events
583 /// emitted during processing of the query.
584 SendReplyChannelRange {
585 /// The node_id of this message recipient
587 /// The reply_channel_range which should be sent.
588 msg: msgs::ReplyChannelRange,
592 /// A trait indicating an object may generate message send events
593 pub trait MessageSendEventsProvider {
594 /// Gets the list of pending events which were generated by previous actions, clearing the list
596 fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
599 /// A trait indicating an object may generate events.
601 /// Events are processed by passing an [`EventHandler`] to [`process_pending_events`].
605 /// See [`process_pending_events`] for requirements around event processing.
607 /// When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
608 /// event since the last invocation. The handler must either act upon the event immediately
609 /// or preserve it for later handling.
611 /// Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
612 /// consult the provider's documentation on the implication of processing events and how a handler
613 /// may safely use the provider (e.g., see [`ChannelManager::process_pending_events`] and
614 /// [`ChainMonitor::process_pending_events`]).
616 /// (C-not implementable) As there is likely no reason for a user to implement this trait on their
619 /// [`process_pending_events`]: Self::process_pending_events
620 /// [`handle_event`]: EventHandler::handle_event
621 /// [`ChannelManager::process_pending_events`]: crate::ln::channelmanager::ChannelManager#method.process_pending_events
622 /// [`ChainMonitor::process_pending_events`]: crate::chain::chainmonitor::ChainMonitor#method.process_pending_events
623 pub trait EventsProvider {
624 /// Processes any events generated since the last call using the given event handler.
626 /// Subsequent calls must only process new events. However, handlers must be capable of handling
627 /// duplicate events across process restarts. This may occur if the provider was recovered from
628 /// an old state (i.e., it hadn't been successfully persisted after processing pending events).
629 fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler;
632 /// A trait implemented for objects handling events from [`EventsProvider`].
633 pub trait EventHandler {
634 /// Handles the given [`Event`].
636 /// See [`EventsProvider`] for details that must be considered when implementing this method.
637 fn handle_event(&self, event: &Event);
640 impl<F> EventHandler for F where F: Fn(&Event) {
641 fn handle_event(&self, event: &Event) {