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};
22 use bitcoin::blockdata::script::Script;
24 use bitcoin::secp256k1::key::PublicKey;
26 use core::time::Duration;
29 /// An Event which you should probably take some action in response to.
31 /// Note that while Writeable and Readable are implemented for Event, you probably shouldn't use
32 /// them directly as they don't round-trip exactly (for example FundingGenerationReady is never
33 /// written as it makes no sense to respond to it after reconnecting to peers).
34 #[derive(Clone, Debug)]
36 /// Used to indicate that the client should generate a funding transaction with the given
37 /// parameters and then call ChannelManager::funding_transaction_generated.
38 /// Generated in ChannelManager message handling.
39 /// Note that *all inputs* in the funding transaction must spend SegWit outputs or your
40 /// counterparty can steal your funds!
41 FundingGenerationReady {
42 /// The random channel_id we picked which you'll need to pass into
43 /// ChannelManager::funding_transaction_generated.
44 temporary_channel_id: [u8; 32],
45 /// The value, in satoshis, that the output should have.
46 channel_value_satoshis: u64,
47 /// The script which should be used in the transaction output.
48 output_script: Script,
49 /// The value passed in to ChannelManager::create_channel
52 /// Indicates we've received money! Just gotta dig out that payment preimage and feed it to
53 /// ChannelManager::claim_funds to get it....
54 /// Note that if the preimage is not known or the amount paid is incorrect, you should call
55 /// ChannelManager::fail_htlc_backwards to free up resources for this HTLC and avoid
56 /// network congestion.
57 /// The amount paid should be considered 'incorrect' when it is less than or more than twice
58 /// the amount expected.
59 /// If you fail to call either ChannelManager::claim_funds or
60 /// ChannelManager::fail_htlc_backwards within the HTLC's timeout, the HTLC will be
61 /// automatically failed.
63 /// The hash for which the preimage should be handed to the ChannelManager.
64 payment_hash: PaymentHash,
65 /// The preimage to the payment_hash, if the payment hash (and secret) were fetched via
66 /// [`ChannelManager::create_inbound_payment`]. If provided, this can be handed directly to
67 /// [`ChannelManager::claim_funds`].
69 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
70 /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
71 payment_preimage: Option<PaymentPreimage>,
72 /// The "payment secret". This authenticates the sender to the recipient, preventing a
73 /// number of deanonymization attacks during the routing process.
74 /// It is provided here for your reference, however its accuracy is enforced directly by
75 /// [`ChannelManager`] using the values you previously provided to
76 /// [`ChannelManager::create_inbound_payment`] or
77 /// [`ChannelManager::create_inbound_payment_for_hash`].
79 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
80 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
81 /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
82 payment_secret: PaymentSecret,
83 /// The value, in thousandths of a satoshi, that this payment is for. Note that you must
84 /// compare this to the expected value before accepting the payment (as otherwise you are
85 /// providing proof-of-payment for less than the value you expected!).
87 /// This is the `user_payment_id` which was provided to
88 /// [`ChannelManager::create_inbound_payment_for_hash`] or
89 /// [`ChannelManager::create_inbound_payment`]. It has no meaning inside of LDK and is
90 /// simply copied here. It may be used to correlate PaymentReceived events with invoice
91 /// metadata stored elsewhere.
93 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
94 /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
97 /// Indicates an outbound payment we made succeeded (ie it made it all the way to its target
98 /// and we got back the payment preimage for it).
100 /// The preimage to the hash given to ChannelManager::send_payment.
101 /// Note that this serves as a payment receipt, if you wish to have such a thing, you must
102 /// store it somehow!
103 payment_preimage: PaymentPreimage,
105 /// Indicates an outbound payment we made failed. Probably some intermediary node dropped
106 /// something. You may wish to retry with a different route.
108 /// The hash which was given to ChannelManager::send_payment.
109 payment_hash: PaymentHash,
110 /// Indicates the payment was rejected for some reason by the recipient. This implies that
111 /// the payment has failed, not just the route in question. If this is not set, you may
112 /// retry the payment via a different route.
113 rejected_by_dest: bool,
115 error_code: Option<u16>,
117 error_data: Option<Vec<u8>>,
119 /// Used to indicate that ChannelManager::process_pending_htlc_forwards should be called at a
120 /// time in the future.
121 PendingHTLCsForwardable {
122 /// The minimum amount of time that should be waited prior to calling
123 /// process_pending_htlc_forwards. To increase the effort required to correlate payments,
124 /// you should wait a random amount of time in roughly the range (now + time_forwardable,
125 /// now + 5*time_forwardable).
126 time_forwardable: Duration,
128 /// Used to indicate that an output was generated on-chain which you should know how to spend.
129 /// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
130 /// counterparty spending them due to some kind of timeout. Thus, you need to store them
131 /// somewhere and spend them when you create on-chain transactions.
133 /// The outputs which you should store as spendable by you.
134 outputs: Vec<SpendableOutputDescriptor>,
138 impl Writeable for Event {
139 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
141 &Event::FundingGenerationReady { .. } => {
143 // We never write out FundingGenerationReady events as, upon disconnection, peers
144 // drop any channels which have not yet exchanged funding_signed.
146 &Event::PaymentReceived { ref payment_hash, ref payment_preimage, ref payment_secret, ref amt, ref user_payment_id } => {
148 payment_hash.write(writer)?;
149 payment_preimage.write(writer)?;
150 payment_secret.write(writer)?;
152 user_payment_id.write(writer)?;
154 &Event::PaymentSent { ref payment_preimage } => {
156 payment_preimage.write(writer)?;
158 &Event::PaymentFailed { ref payment_hash, ref rejected_by_dest,
165 payment_hash.write(writer)?;
166 rejected_by_dest.write(writer)?;
168 error_code.write(writer)?;
170 error_data.write(writer)?;
172 &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
174 // We don't write the time_fordwardable out at all, as we presume when the user
175 // deserializes us at least that much time has elapsed.
177 &Event::SpendableOutputs { ref outputs } => {
179 (outputs.len() as u64).write(writer)?;
180 for output in outputs.iter() {
181 output.write(writer)?;
188 impl MaybeReadable for Event {
189 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
190 match Readable::read(reader)? {
192 1u8 => Ok(Some(Event::PaymentReceived {
193 payment_hash: Readable::read(reader)?,
194 payment_preimage: Readable::read(reader)?,
195 payment_secret: Readable::read(reader)?,
196 amt: Readable::read(reader)?,
197 user_payment_id: Readable::read(reader)?,
199 2u8 => Ok(Some(Event::PaymentSent {
200 payment_preimage: Readable::read(reader)?,
202 3u8 => Ok(Some(Event::PaymentFailed {
203 payment_hash: Readable::read(reader)?,
204 rejected_by_dest: Readable::read(reader)?,
206 error_code: Readable::read(reader)?,
208 error_data: Readable::read(reader)?,
210 4u8 => Ok(Some(Event::PendingHTLCsForwardable {
211 time_forwardable: Duration::from_secs(0)
214 let outputs_len: u64 = Readable::read(reader)?;
215 let mut outputs = Vec::new();
216 for _ in 0..outputs_len {
217 outputs.push(Readable::read(reader)?);
219 Ok(Some(Event::SpendableOutputs { outputs }))
221 _ => Err(msgs::DecodeError::InvalidValue)
226 /// An event generated by ChannelManager which indicates a message should be sent to a peer (or
227 /// broadcast to most peers).
228 /// These events are handled by PeerManager::process_events if you are using a PeerManager.
229 #[derive(Clone, Debug)]
230 pub enum MessageSendEvent {
231 /// Used to indicate that we've accepted a channel open and should send the accept_channel
232 /// message provided to the given peer.
234 /// The node_id of the node which should receive this message
236 /// The message which should be sent.
237 msg: msgs::AcceptChannel,
239 /// Used to indicate that we've initiated a channel open and should send the open_channel
240 /// message provided to the given peer.
242 /// The node_id of the node which should receive this message
244 /// The message which should be sent.
245 msg: msgs::OpenChannel,
247 /// Used to indicate that a funding_created message should be sent to the peer with the given node_id.
249 /// The node_id of the node which should receive this message
251 /// The message which should be sent.
252 msg: msgs::FundingCreated,
254 /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id.
256 /// The node_id of the node which should receive this message
258 /// The message which should be sent.
259 msg: msgs::FundingSigned,
261 /// Used to indicate that a funding_locked message should be sent to the peer with the given node_id.
263 /// The node_id of the node which should receive these message(s)
265 /// The funding_locked message which should be sent.
266 msg: msgs::FundingLocked,
268 /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
269 SendAnnouncementSignatures {
270 /// The node_id of the node which should receive these message(s)
272 /// The announcement_signatures message which should be sent.
273 msg: msgs::AnnouncementSignatures,
275 /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed
276 /// message should be sent to the peer with the given node_id.
278 /// The node_id of the node which should receive these message(s)
280 /// The update messages which should be sent. ALL messages in the struct should be sent!
281 updates: msgs::CommitmentUpdate,
283 /// Used to indicate that a revoke_and_ack message should be sent to the peer with the given node_id.
285 /// The node_id of the node which should receive this message
287 /// The message which should be sent.
288 msg: msgs::RevokeAndACK,
290 /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id.
292 /// The node_id of the node which should receive this message
294 /// The message which should be sent.
295 msg: msgs::ClosingSigned,
297 /// Used to indicate that a shutdown message should be sent to the peer with the given node_id.
299 /// The node_id of the node which should receive this message
301 /// The message which should be sent.
304 /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id.
305 SendChannelReestablish {
306 /// The node_id of the node which should receive this message
308 /// The message which should be sent.
309 msg: msgs::ChannelReestablish,
311 /// Used to indicate that a channel_announcement and channel_update should be broadcast to all
312 /// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
314 /// Note that after doing so, you very likely (unless you did so very recently) want to call
315 /// ChannelManager::broadcast_node_announcement to trigger a BroadcastNodeAnnouncement event.
316 /// This ensures that any nodes which see our channel_announcement also have a relevant
317 /// node_announcement, including relevant feature flags which may be important for routing
318 /// through or to us.
319 BroadcastChannelAnnouncement {
320 /// The channel_announcement which should be sent.
321 msg: msgs::ChannelAnnouncement,
322 /// The followup channel_update which should be sent.
323 update_msg: msgs::ChannelUpdate,
325 /// Used to indicate that a node_announcement should be broadcast to all peers.
326 BroadcastNodeAnnouncement {
327 /// The node_announcement which should be sent.
328 msg: msgs::NodeAnnouncement,
330 /// Used to indicate that a channel_update should be broadcast to all peers.
331 BroadcastChannelUpdate {
332 /// The channel_update which should be sent.
333 msg: msgs::ChannelUpdate,
335 /// Broadcast an error downstream to be handled
337 /// The node_id of the node which should receive this message
339 /// The action which should be taken.
340 action: msgs::ErrorAction
342 /// When a payment fails we may receive updates back from the hop where it failed. In such
343 /// cases this event is generated so that we can inform the network graph of this information.
344 PaymentFailureNetworkUpdate {
345 /// The channel/node update which should be sent to NetGraphMsgHandler
346 update: msgs::HTLCFailChannelUpdate,
348 /// Query a peer for channels with funding transaction UTXOs in a block range.
349 SendChannelRangeQuery {
350 /// The node_id of this message recipient
352 /// The query_channel_range which should be sent.
353 msg: msgs::QueryChannelRange,
355 /// Request routing gossip messages from a peer for a list of channels identified by
356 /// their short_channel_ids.
358 /// The node_id of this message recipient
360 /// The query_short_channel_ids which should be sent.
361 msg: msgs::QueryShortChannelIds,
363 /// Sends a reply to a channel range query. This may be one of several SendReplyChannelRange events
364 /// emitted during processing of the query.
365 SendReplyChannelRange {
366 /// The node_id of this message recipient
368 /// The reply_channel_range which should be sent.
369 msg: msgs::ReplyChannelRange,
373 /// A trait indicating an object may generate message send events
374 pub trait MessageSendEventsProvider {
375 /// Gets the list of pending events which were generated by previous actions, clearing the list
377 fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
380 /// A trait indicating an object may generate events.
382 /// Events are processed by passing an [`EventHandler`] to [`process_pending_events`].
386 /// See [`process_pending_events`] for requirements around event processing.
388 /// When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
389 /// event since the last invocation. The handler must either act upon the event immediately
390 /// or preserve it for later handling.
392 /// Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
393 /// consult the provider's documentation on the implication of processing events and how a handler
394 /// may safely use the provider (e.g., see [`ChannelManager::process_pending_events`] and
395 /// [`ChainMonitor::process_pending_events`]).
397 /// [`process_pending_events`]: Self::process_pending_events
398 /// [`handle_event`]: EventHandler::handle_event
399 /// [`ChannelManager::process_pending_events`]: crate::ln::channelmanager::ChannelManager#method.process_pending_events
400 /// [`ChainMonitor::process_pending_events`]: crate::chain::chainmonitor::ChainMonitor#method.process_pending_events
401 pub trait EventsProvider {
402 /// Processes any events generated since the last call using the given event handler.
404 /// Subsequent calls must only process new events. However, handlers must be capable of handling
405 /// duplicate events across process restarts. This may occur if the provider was recovered from
406 /// an old state (i.e., it hadn't been successfully persisted after processing pending events).
407 fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler;
410 /// A trait implemented for objects handling events from [`EventsProvider`].
411 pub trait EventHandler {
412 /// Handles the given [`Event`].
414 /// See [`EventsProvider`] for details that must be considered when implementing this method.
415 fn handle_event(&self, event: Event);
418 impl<F> EventHandler for F where F: Fn(Event) {
419 fn handle_event(&self, event: Event) {