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 /// An Event which you should probably take some action in response to.
32 /// Note that while Writeable and Readable are implemented for Event, you probably shouldn't use
33 /// them directly as they don't round-trip exactly (for example FundingGenerationReady is never
34 /// written as it makes no sense to respond to it after reconnecting to peers).
35 #[derive(Clone, Debug)]
37 /// Used to indicate that the client should generate a funding transaction with the given
38 /// parameters and then call ChannelManager::funding_transaction_generated.
39 /// Generated in ChannelManager message handling.
40 /// Note that *all inputs* in the funding transaction must spend SegWit outputs or your
41 /// counterparty can steal your funds!
42 FundingGenerationReady {
43 /// The random channel_id we picked which you'll need to pass into
44 /// ChannelManager::funding_transaction_generated.
45 temporary_channel_id: [u8; 32],
46 /// The value, in satoshis, that the output should have.
47 channel_value_satoshis: u64,
48 /// The script which should be used in the transaction output.
49 output_script: Script,
50 /// The value passed in to ChannelManager::create_channel
53 /// Indicates we've received money! Just gotta dig out that payment preimage and feed it to
54 /// ChannelManager::claim_funds to get it....
55 /// Note that if the preimage is not known or the amount paid is incorrect, you should call
56 /// ChannelManager::fail_htlc_backwards to free up resources for this HTLC and avoid
57 /// network congestion.
58 /// The amount paid should be considered 'incorrect' when it is less than or more than twice
59 /// the amount expected.
60 /// If you fail to call either ChannelManager::claim_funds or
61 /// ChannelManager::fail_htlc_backwards within the HTLC's timeout, the HTLC will be
62 /// automatically failed.
64 /// The hash for which the preimage should be handed to the ChannelManager.
65 payment_hash: PaymentHash,
66 /// The preimage to the payment_hash, if the payment hash (and secret) were fetched via
67 /// [`ChannelManager::create_inbound_payment`]. If provided, this can be handed directly to
68 /// [`ChannelManager::claim_funds`].
70 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
71 /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
72 payment_preimage: Option<PaymentPreimage>,
73 /// The "payment secret". This authenticates the sender to the recipient, preventing a
74 /// number of deanonymization attacks during the routing process.
75 /// It is provided here for your reference, however its accuracy is enforced directly by
76 /// [`ChannelManager`] using the values you previously provided to
77 /// [`ChannelManager::create_inbound_payment`] or
78 /// [`ChannelManager::create_inbound_payment_for_hash`].
80 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
81 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
82 /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
83 payment_secret: PaymentSecret,
84 /// The value, in thousandths of a satoshi, that this payment is for. Note that you must
85 /// compare this to the expected value before accepting the payment (as otherwise you are
86 /// providing proof-of-payment for less than the value you expected!).
88 /// This is the `user_payment_id` which was provided to
89 /// [`ChannelManager::create_inbound_payment_for_hash`] or
90 /// [`ChannelManager::create_inbound_payment`]. It has no meaning inside of LDK and is
91 /// simply copied here. It may be used to correlate PaymentReceived events with invoice
92 /// metadata stored elsewhere.
94 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
95 /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
98 /// Indicates an outbound payment we made succeeded (ie it made it all the way to its target
99 /// and we got back the payment preimage for it).
101 /// The preimage to the hash given to ChannelManager::send_payment.
102 /// Note that this serves as a payment receipt, if you wish to have such a thing, you must
103 /// store it somehow!
104 payment_preimage: PaymentPreimage,
106 /// Indicates an outbound payment we made failed. Probably some intermediary node dropped
107 /// something. You may wish to retry with a different route.
109 /// The hash which was given to ChannelManager::send_payment.
110 payment_hash: PaymentHash,
111 /// Indicates the payment was rejected for some reason by the recipient. This implies that
112 /// the payment has failed, not just the route in question. If this is not set, you may
113 /// retry the payment via a different route.
114 rejected_by_dest: bool,
116 error_code: Option<u16>,
118 error_data: Option<Vec<u8>>,
120 /// Used to indicate that ChannelManager::process_pending_htlc_forwards should be called at a
121 /// time in the future.
122 PendingHTLCsForwardable {
123 /// The minimum amount of time that should be waited prior to calling
124 /// process_pending_htlc_forwards. To increase the effort required to correlate payments,
125 /// you should wait a random amount of time in roughly the range (now + time_forwardable,
126 /// now + 5*time_forwardable).
127 time_forwardable: Duration,
129 /// Used to indicate that an output which you should know how to spend was confirmed on chain
130 /// and is now spendable.
131 /// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
132 /// counterparty spending them due to some kind of timeout. Thus, you need to store them
133 /// somewhere and spend them when you create on-chain transactions.
135 /// The outputs which you should store as spendable by you.
136 outputs: Vec<SpendableOutputDescriptor>,
140 impl Writeable for Event {
141 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
143 &Event::FundingGenerationReady { .. } => {
145 // We never write out FundingGenerationReady events as, upon disconnection, peers
146 // drop any channels which have not yet exchanged funding_signed.
148 &Event::PaymentReceived { ref payment_hash, ref payment_preimage, ref payment_secret, ref amt, ref user_payment_id } => {
150 write_tlv_fields!(writer, {
151 (0, payment_hash, required),
152 (2, payment_secret, required),
154 (6, user_payment_id, required),
155 (8, payment_preimage, option),
158 &Event::PaymentSent { ref payment_preimage } => {
160 write_tlv_fields!(writer, {
161 (0, payment_preimage, required),
163 payment_preimage.write(writer)?;
165 &Event::PaymentFailed { ref payment_hash, ref rejected_by_dest,
173 error_code.write(writer)?;
175 error_data.write(writer)?;
176 write_tlv_fields!(writer, {
177 (0, payment_hash, required),
178 (2, rejected_by_dest, required),
181 &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
183 write_tlv_fields!(writer, {});
184 // We don't write the time_fordwardable out at all, as we presume when the user
185 // deserializes us at least that much time has elapsed.
187 &Event::SpendableOutputs { ref outputs } => {
189 write_tlv_fields!(writer, {
190 (0, VecWriteWrapper(outputs), required),
197 impl MaybeReadable for Event {
198 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
199 match Readable::read(reader)? {
203 let mut payment_hash = PaymentHash([0; 32]);
204 let mut payment_preimage = None;
205 let mut payment_secret = PaymentSecret([0; 32]);
207 let mut user_payment_id = 0;
208 read_tlv_fields!(reader, {
209 (0, payment_hash, required),
210 (2, payment_secret, required),
212 (6, user_payment_id, required),
213 (8, payment_preimage, option),
215 Ok(Some(Event::PaymentReceived {
227 let mut payment_preimage = PaymentPreimage([0; 32]);
228 read_tlv_fields!(reader, {
229 (0, payment_preimage, required),
231 Ok(Some(Event::PaymentSent {
240 let error_code = Readable::read(reader)?;
242 let error_data = Readable::read(reader)?;
243 let mut payment_hash = PaymentHash([0; 32]);
244 let mut rejected_by_dest = false;
245 read_tlv_fields!(reader, {
246 (0, payment_hash, required),
247 (2, rejected_by_dest, required),
249 Ok(Some(Event::PaymentFailed {
262 read_tlv_fields!(reader, {});
263 Ok(Some(Event::PendingHTLCsForwardable {
264 time_forwardable: Duration::from_secs(0)
271 let mut outputs = VecReadWrapper(Vec::new());
272 read_tlv_fields!(reader, {
273 (0, outputs, required),
275 Ok(Some(Event::SpendableOutputs { outputs: outputs.0 }))
279 _ => Err(msgs::DecodeError::InvalidValue)
284 /// An event generated by ChannelManager which indicates a message should be sent to a peer (or
285 /// broadcast to most peers).
286 /// These events are handled by PeerManager::process_events if you are using a PeerManager.
287 #[derive(Clone, Debug)]
288 pub enum MessageSendEvent {
289 /// Used to indicate that we've accepted a channel open and should send the accept_channel
290 /// message provided to the given peer.
292 /// The node_id of the node which should receive this message
294 /// The message which should be sent.
295 msg: msgs::AcceptChannel,
297 /// Used to indicate that we've initiated a channel open and should send the open_channel
298 /// message provided to the given peer.
300 /// The node_id of the node which should receive this message
302 /// The message which should be sent.
303 msg: msgs::OpenChannel,
305 /// Used to indicate that a funding_created message should be sent to the peer with the given node_id.
307 /// The node_id of the node which should receive this message
309 /// The message which should be sent.
310 msg: msgs::FundingCreated,
312 /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id.
314 /// The node_id of the node which should receive this message
316 /// The message which should be sent.
317 msg: msgs::FundingSigned,
319 /// Used to indicate that a funding_locked message should be sent to the peer with the given node_id.
321 /// The node_id of the node which should receive these message(s)
323 /// The funding_locked message which should be sent.
324 msg: msgs::FundingLocked,
326 /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
327 SendAnnouncementSignatures {
328 /// The node_id of the node which should receive these message(s)
330 /// The announcement_signatures message which should be sent.
331 msg: msgs::AnnouncementSignatures,
333 /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed
334 /// message should be sent to the peer with the given node_id.
336 /// The node_id of the node which should receive these message(s)
338 /// The update messages which should be sent. ALL messages in the struct should be sent!
339 updates: msgs::CommitmentUpdate,
341 /// Used to indicate that a revoke_and_ack message should be sent to the peer with the given node_id.
343 /// The node_id of the node which should receive this message
345 /// The message which should be sent.
346 msg: msgs::RevokeAndACK,
348 /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id.
350 /// The node_id of the node which should receive this message
352 /// The message which should be sent.
353 msg: msgs::ClosingSigned,
355 /// Used to indicate that a shutdown message should be sent to the peer with the given node_id.
357 /// The node_id of the node which should receive this message
359 /// The message which should be sent.
362 /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id.
363 SendChannelReestablish {
364 /// The node_id of the node which should receive this message
366 /// The message which should be sent.
367 msg: msgs::ChannelReestablish,
369 /// Used to indicate that a channel_announcement and channel_update should be broadcast to all
370 /// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
372 /// Note that after doing so, you very likely (unless you did so very recently) want to call
373 /// ChannelManager::broadcast_node_announcement to trigger a BroadcastNodeAnnouncement event.
374 /// This ensures that any nodes which see our channel_announcement also have a relevant
375 /// node_announcement, including relevant feature flags which may be important for routing
376 /// through or to us.
377 BroadcastChannelAnnouncement {
378 /// The channel_announcement which should be sent.
379 msg: msgs::ChannelAnnouncement,
380 /// The followup channel_update which should be sent.
381 update_msg: msgs::ChannelUpdate,
383 /// Used to indicate that a node_announcement should be broadcast to all peers.
384 BroadcastNodeAnnouncement {
385 /// The node_announcement which should be sent.
386 msg: msgs::NodeAnnouncement,
388 /// Used to indicate that a channel_update should be broadcast to all peers.
389 BroadcastChannelUpdate {
390 /// The channel_update which should be sent.
391 msg: msgs::ChannelUpdate,
393 /// Broadcast an error downstream to be handled
395 /// The node_id of the node which should receive this message
397 /// The action which should be taken.
398 action: msgs::ErrorAction
400 /// When a payment fails we may receive updates back from the hop where it failed. In such
401 /// cases this event is generated so that we can inform the network graph of this information.
402 PaymentFailureNetworkUpdate {
403 /// The channel/node update which should be sent to NetGraphMsgHandler
404 update: msgs::HTLCFailChannelUpdate,
406 /// Query a peer for channels with funding transaction UTXOs in a block range.
407 SendChannelRangeQuery {
408 /// The node_id of this message recipient
410 /// The query_channel_range which should be sent.
411 msg: msgs::QueryChannelRange,
413 /// Request routing gossip messages from a peer for a list of channels identified by
414 /// their short_channel_ids.
416 /// The node_id of this message recipient
418 /// The query_short_channel_ids which should be sent.
419 msg: msgs::QueryShortChannelIds,
421 /// Sends a reply to a channel range query. This may be one of several SendReplyChannelRange events
422 /// emitted during processing of the query.
423 SendReplyChannelRange {
424 /// The node_id of this message recipient
426 /// The reply_channel_range which should be sent.
427 msg: msgs::ReplyChannelRange,
431 /// A trait indicating an object may generate message send events
432 pub trait MessageSendEventsProvider {
433 /// Gets the list of pending events which were generated by previous actions, clearing the list
435 fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
438 /// A trait indicating an object may generate events.
440 /// Events are processed by passing an [`EventHandler`] to [`process_pending_events`].
444 /// See [`process_pending_events`] for requirements around event processing.
446 /// When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
447 /// event since the last invocation. The handler must either act upon the event immediately
448 /// or preserve it for later handling.
450 /// Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
451 /// consult the provider's documentation on the implication of processing events and how a handler
452 /// may safely use the provider (e.g., see [`ChannelManager::process_pending_events`] and
453 /// [`ChainMonitor::process_pending_events`]).
455 /// (C-not implementable) As there is likely no reason for a user to implement this trait on their
458 /// [`process_pending_events`]: Self::process_pending_events
459 /// [`handle_event`]: EventHandler::handle_event
460 /// [`ChannelManager::process_pending_events`]: crate::ln::channelmanager::ChannelManager#method.process_pending_events
461 /// [`ChainMonitor::process_pending_events`]: crate::chain::chainmonitor::ChainMonitor#method.process_pending_events
462 pub trait EventsProvider {
463 /// Processes any events generated since the last call using the given event handler.
465 /// Subsequent calls must only process new events. However, handlers must be capable of handling
466 /// duplicate events across process restarts. This may occur if the provider was recovered from
467 /// an old state (i.e., it hadn't been successfully persisted after processing pending events).
468 fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler;
471 /// A trait implemented for objects handling events from [`EventsProvider`].
472 pub trait EventHandler {
473 /// Handles the given [`Event`].
475 /// See [`EventsProvider`] for details that must be considered when implementing this method.
476 fn handle_event(&self, event: Event);
479 impl<F> EventHandler for F where F: Fn(Event) {
480 fn handle_event(&self, event: Event) {