1 //! Events are returned from various bits in the library which indicate some action must be taken
4 //! Because we don't have a built-in runtime, it's up to the client to call events at a time in the
5 //! future, as well as generate and broadcast funding transactions handle payment preimages and a
8 //! Note that many events are handled for you by PeerHandler, so in the common design of having a
9 //! PeerManager which marshalls messages to ChannelManager and Router you only need to call
10 //! process_events on the PeerHandler and then get_and_clear_pending_events and handle the events
11 //! that bubble up to the surface. If, however, you do not have a PeerHandler managing a
12 //! ChannelManager you need to handle all of the events which may be generated.
13 //TODO: We need better separation of event types ^
16 use ln::channelmanager::{PaymentPreimage, PaymentHash};
17 use chain::transaction::OutPoint;
18 use chain::keysinterface::SpendableOutputDescriptor;
19 use util::ser::{Writeable, Writer, MaybeReadable, Readable};
21 use bitcoin::blockdata::script::Script;
23 use secp256k1::key::PublicKey;
25 use std::time::Duration;
27 /// An Event which you should probably take some action in response to.
29 /// Note that while Writeable and Readable are implemented for Event, you probably shouldn't use
30 /// them directly as they don't round-trip exactly (for example FundingGenerationReady is never
31 /// written as it makes no sense to respond to it after reconnecting to peers).
33 /// Used to indicate that the client should generate a funding transaction with the given
34 /// parameters and then call ChannelManager::funding_transaction_generated.
35 /// Generated in ChannelManager message handling.
36 /// Note that *all inputs* in the funding transaction must spend SegWit outputs or your
37 /// counterparty can steal your funds!
38 FundingGenerationReady {
39 /// The random channel_id we picked which you'll need to pass into
40 /// ChannelManager::funding_transaction_generated.
41 temporary_channel_id: [u8; 32],
42 /// The value, in satoshis, that the output should have.
43 channel_value_satoshis: u64,
44 /// The script which should be used in the transaction output.
45 output_script: Script,
46 /// The value passed in to ChannelManager::create_channel
49 /// Used to indicate that the client may now broadcast the funding transaction it created for a
50 /// channel. Broadcasting such a transaction prior to this event may lead to our counterparty
51 /// trivially stealing all funds in the funding transaction!
52 FundingBroadcastSafe {
53 /// The output, which was passed to ChannelManager::funding_transaction_generated, which is
54 /// now safe to broadcast.
55 funding_txo: OutPoint,
56 /// The value passed in to ChannelManager::create_channel
59 /// Indicates we've received money! Just gotta dig out that payment preimage and feed it to
60 /// ChannelManager::claim_funds to get it....
61 /// Note that if the preimage is not known or the amount paid is incorrect, you must call
62 /// ChannelManager::fail_htlc_backwards to free up resources for this HTLC.
63 /// The amount paid should be considered 'incorrect' when it is less than or more than twice
64 /// the amount expected.
66 /// The hash for which the preimage should be handed to the ChannelManager.
67 payment_hash: PaymentHash,
68 /// The value, in thousandths of a satoshi, that this payment is for. Note that you must
69 /// compare this to the expected value before accepting the payment (as otherwise you are
70 /// providing proof-of-payment for less than the value you expected!).
73 /// Indicates an outbound payment we made succeeded (ie it made it all the way to its target
74 /// and we got back the payment preimage for it).
75 /// Note that duplicative PaymentSent Events may be generated - it is your responsibility to
76 /// deduplicate them by payment_preimage (which MUST be unique)!
78 /// The preimage to the hash given to ChannelManager::send_payment.
79 /// Note that this serves as a payment receipt, if you wish to have such a thing, you must
81 payment_preimage: PaymentPreimage,
83 /// Indicates an outbound payment we made failed. Probably some intermediary node dropped
84 /// something. You may wish to retry with a different route.
85 /// Note that duplicative PaymentFailed Events may be generated - it is your responsibility to
86 /// deduplicate them by payment_hash (which MUST be unique)!
88 /// The hash which was given to ChannelManager::send_payment.
89 payment_hash: PaymentHash,
90 /// Indicates the payment was rejected for some reason by the recipient. This implies that
91 /// the payment has failed, not just the route in question. If this is not set, you may
92 /// retry the payment via a different route.
93 rejected_by_dest: bool,
95 error_code: Option<u16>,
97 /// Used to indicate that ChannelManager::process_pending_htlc_forwards should be called at a
98 /// time in the future.
99 PendingHTLCsForwardable {
100 /// The minimum amount of time that should be waited prior to calling
101 /// process_pending_htlc_forwards. To increase the effort required to correlate payments,
102 /// you should wait a random amount of time in roughly the range (now + time_forwardable,
103 /// now + 5*time_forwardable).
104 time_forwardable: Duration,
106 /// Used to indicate that an output was generated on-chain which you should know how to spend.
107 /// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
108 /// counterparty spending them due to some kind of timeout. Thus, you need to store them
109 /// somewhere and spend them when you create on-chain transactions.
111 /// The outputs which you should store as spendable by you.
112 outputs: Vec<SpendableOutputDescriptor>,
116 impl Writeable for Event {
117 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
119 &Event::FundingGenerationReady { .. } => {
121 // We never write out FundingGenerationReady events as, upon disconnection, peers
122 // drop any channels which have not yet exchanged funding_signed.
124 &Event::FundingBroadcastSafe { ref funding_txo, ref user_channel_id } => {
126 funding_txo.write(writer)?;
127 user_channel_id.write(writer)?;
129 &Event::PaymentReceived { ref payment_hash, ref amt } => {
131 payment_hash.write(writer)?;
134 &Event::PaymentSent { ref payment_preimage } => {
136 payment_preimage.write(writer)?;
138 &Event::PaymentFailed { ref payment_hash, ref rejected_by_dest,
143 payment_hash.write(writer)?;
144 rejected_by_dest.write(writer)?;
146 error_code.write(writer)?;
148 &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
150 // We don't write the time_fordwardable out at all, as we presume when the user
151 // deserializes us at least that much time has elapsed.
153 &Event::SpendableOutputs { ref outputs } => {
155 (outputs.len() as u64).write(writer)?;
156 for output in outputs.iter() {
157 output.write(writer)?;
164 impl<R: ::std::io::Read> MaybeReadable<R> for Event {
165 fn read(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
166 match Readable::read(reader)? {
168 1u8 => Ok(Some(Event::FundingBroadcastSafe {
169 funding_txo: Readable::read(reader)?,
170 user_channel_id: Readable::read(reader)?,
172 2u8 => Ok(Some(Event::PaymentReceived {
173 payment_hash: Readable::read(reader)?,
174 amt: Readable::read(reader)?,
176 3u8 => Ok(Some(Event::PaymentSent {
177 payment_preimage: Readable::read(reader)?,
179 4u8 => Ok(Some(Event::PaymentFailed {
180 payment_hash: Readable::read(reader)?,
181 rejected_by_dest: Readable::read(reader)?,
183 error_code: Readable::read(reader)?,
185 5u8 => Ok(Some(Event::PendingHTLCsForwardable {
186 time_forwardable: Duration::from_secs(0)
189 let outputs_len: u64 = Readable::read(reader)?;
190 let mut outputs = Vec::new();
191 for _ in 0..outputs_len {
192 outputs.push(Readable::read(reader)?);
194 Ok(Some(Event::SpendableOutputs { outputs }))
196 _ => Err(msgs::DecodeError::InvalidValue)
201 /// An event generated by ChannelManager which indicates a message should be sent to a peer (or
202 /// broadcast to most peers).
203 /// These events are handled by PeerManager::process_events if you are using a PeerManager.
205 pub enum MessageSendEvent {
206 /// Used to indicate that we've accepted a channel open and should send the accept_channel
207 /// message provided to the given peer.
209 /// The node_id of the node which should receive this message
211 /// The message which should be sent.
212 msg: msgs::AcceptChannel,
214 /// Used to indicate that we've initiated a channel open and should send the open_channel
215 /// message provided to the given peer.
217 /// The node_id of the node which should receive this message
219 /// The message which should be sent.
220 msg: msgs::OpenChannel,
222 /// Used to indicate that a funding_created message should be sent to the peer with the given node_id.
224 /// The node_id of the node which should receive this message
226 /// The message which should be sent.
227 msg: msgs::FundingCreated,
229 /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id.
231 /// The node_id of the node which should receive this message
233 /// The message which should be sent.
234 msg: msgs::FundingSigned,
236 /// Used to indicate that a funding_locked message should be sent to the peer with the given node_id.
238 /// The node_id of the node which should receive these message(s)
240 /// The funding_locked message which should be sent.
241 msg: msgs::FundingLocked,
243 /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
244 SendAnnouncementSignatures {
245 /// The node_id of the node which should receive these message(s)
247 /// The announcement_signatures message which should be sent.
248 msg: msgs::AnnouncementSignatures,
250 /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed
251 /// message should be sent to the peer with the given node_id.
253 /// The node_id of the node which should receive these message(s)
255 /// The update messages which should be sent. ALL messages in the struct should be sent!
256 updates: msgs::CommitmentUpdate,
258 /// Used to indicate that a revoke_and_ack message should be sent to the peer with the given node_id.
260 /// The node_id of the node which should receive this message
262 /// The message which should be sent.
263 msg: msgs::RevokeAndACK,
265 /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id.
267 /// The node_id of the node which should receive this message
269 /// The message which should be sent.
270 msg: msgs::ClosingSigned,
272 /// Used to indicate that a shutdown message should be sent to the peer with the given node_id.
274 /// The node_id of the node which should receive this message
276 /// The message which should be sent.
279 /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id.
280 SendChannelReestablish {
281 /// The node_id of the node which should receive this message
283 /// The message which should be sent.
284 msg: msgs::ChannelReestablish,
286 /// Used to indicate that a channel_announcement and channel_update should be broadcast to all
287 /// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
288 BroadcastChannelAnnouncement {
289 /// The channel_announcement which should be sent.
290 msg: msgs::ChannelAnnouncement,
291 /// The followup channel_update which should be sent.
292 update_msg: msgs::ChannelUpdate,
294 /// Used to indicate that a channel_update should be broadcast to all peers.
295 BroadcastChannelUpdate {
296 /// The channel_update which should be sent.
297 msg: msgs::ChannelUpdate,
299 /// Broadcast an error downstream to be handled
301 /// The node_id of the node which should receive this message
303 /// The action which should be taken.
304 action: msgs::ErrorAction
306 /// When a payment fails we may receive updates back from the hop where it failed. In such
307 /// cases this event is generated so that we can inform the router of this information.
308 PaymentFailureNetworkUpdate {
309 /// The channel/node update which should be sent to router
310 update: msgs::HTLCFailChannelUpdate,
314 /// A trait indicating an object may generate message send events
315 pub trait MessageSendEventsProvider {
316 /// Gets the list of pending events which were generated by previous actions, clearing the list
318 fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
321 /// A trait indicating an object may generate events
322 pub trait EventsProvider {
323 /// Gets the list of pending events which were generated by previous actions, clearing the list
325 fn get_and_clear_pending_events(&self) -> Vec<Event>;