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
9 use ln::channelmanager::{PaymentPreimage, PaymentHash, PaymentSecret};
10 use chain::transaction::OutPoint;
11 use chain::keysinterface::SpendableOutputDescriptor;
12 use util::ser::{Writeable, Writer, MaybeReadable, Readable};
14 use bitcoin::blockdata::script::Script;
16 use secp256k1::key::PublicKey;
18 use std::time::Duration;
20 /// An Event which you should probably take some action in response to.
22 /// Note that while Writeable and Readable are implemented for Event, you probably shouldn't use
23 /// them directly as they don't round-trip exactly (for example FundingGenerationReady is never
24 /// written as it makes no sense to respond to it after reconnecting to peers).
26 /// Used to indicate that the client should generate a funding transaction with the given
27 /// parameters and then call ChannelManager::funding_transaction_generated.
28 /// Generated in ChannelManager message handling.
29 /// Note that *all inputs* in the funding transaction must spend SegWit outputs or your
30 /// counterparty can steal your funds!
31 FundingGenerationReady {
32 /// The random channel_id we picked which you'll need to pass into
33 /// ChannelManager::funding_transaction_generated.
34 temporary_channel_id: [u8; 32],
35 /// The value, in satoshis, that the output should have.
36 channel_value_satoshis: u64,
37 /// The script which should be used in the transaction output.
38 output_script: Script,
39 /// The value passed in to ChannelManager::create_channel
42 /// Used to indicate that the client may now broadcast the funding transaction it created for a
43 /// channel. Broadcasting such a transaction prior to this event may lead to our counterparty
44 /// trivially stealing all funds in the funding transaction!
45 FundingBroadcastSafe {
46 /// The output, which was passed to ChannelManager::funding_transaction_generated, which is
47 /// now safe to broadcast.
48 funding_txo: OutPoint,
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 must call
55 /// ChannelManager::fail_htlc_backwards to free up resources for this HTLC.
56 /// The amount paid should be considered 'incorrect' when it is less than or more than twice
57 /// the amount expected.
58 /// If you fail to call either ChannelManager::claim_funds or
59 /// ChannelManager::fail_htlc_backwards within the HTLC's timeout, the HTLC will be
60 /// automatically failed.
62 /// The hash for which the preimage should be handed to the ChannelManager.
63 payment_hash: PaymentHash,
64 /// The "payment secret". This authenticates the sender to the recipient, preventing a
65 /// number of deanonymization attacks during the routing process.
66 /// As nodes upgrade, the invoices you provide should likely migrate to setting the
67 /// payment_secret feature to required, at which point you should fail_backwards any HTLCs
68 /// which have a None here.
69 /// Until then, however, values of None should be ignored, and only incorrect Some values
70 /// should result in an HTLC fail_backwards.
71 /// Note that, in any case, this value must be passed as-is to any fail or claim calls as
72 /// the HTLC index includes this value.
73 payment_secret: Option<PaymentSecret>,
74 /// The value, in thousandths of a satoshi, that this payment is for. Note that you must
75 /// compare this to the expected value before accepting the payment (as otherwise you are
76 /// providing proof-of-payment for less than the value you expected!).
79 /// Indicates an outbound payment we made succeeded (ie it made it all the way to its target
80 /// and we got back the payment preimage for it).
81 /// Note that duplicative PaymentSent Events may be generated - it is your responsibility to
82 /// deduplicate them by payment_preimage (which MUST be unique)!
84 /// The preimage to the hash given to ChannelManager::send_payment.
85 /// Note that this serves as a payment receipt, if you wish to have such a thing, you must
87 payment_preimage: PaymentPreimage,
89 /// Indicates an outbound payment we made failed. Probably some intermediary node dropped
90 /// something. You may wish to retry with a different route.
91 /// Note that duplicative PaymentFailed Events may be generated - it is your responsibility to
92 /// deduplicate them by payment_hash (which MUST be unique)!
94 /// The hash which was given to ChannelManager::send_payment.
95 payment_hash: PaymentHash,
96 /// Indicates the payment was rejected for some reason by the recipient. This implies that
97 /// the payment has failed, not just the route in question. If this is not set, you may
98 /// retry the payment via a different route.
99 rejected_by_dest: bool,
101 error_code: Option<u16>,
103 error_data: Option<Vec<u8>>,
105 /// Used to indicate that ChannelManager::process_pending_htlc_forwards should be called at a
106 /// time in the future.
107 PendingHTLCsForwardable {
108 /// The minimum amount of time that should be waited prior to calling
109 /// process_pending_htlc_forwards. To increase the effort required to correlate payments,
110 /// you should wait a random amount of time in roughly the range (now + time_forwardable,
111 /// now + 5*time_forwardable).
112 time_forwardable: Duration,
114 /// Used to indicate that an output was generated on-chain which you should know how to spend.
115 /// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
116 /// counterparty spending them due to some kind of timeout. Thus, you need to store them
117 /// somewhere and spend them when you create on-chain transactions.
119 /// The outputs which you should store as spendable by you.
120 outputs: Vec<SpendableOutputDescriptor>,
124 impl Writeable for Event {
125 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
127 &Event::FundingGenerationReady { .. } => {
129 // We never write out FundingGenerationReady events as, upon disconnection, peers
130 // drop any channels which have not yet exchanged funding_signed.
132 &Event::FundingBroadcastSafe { ref funding_txo, ref user_channel_id } => {
134 funding_txo.write(writer)?;
135 user_channel_id.write(writer)?;
137 &Event::PaymentReceived { ref payment_hash, ref payment_secret, ref amt } => {
139 payment_hash.write(writer)?;
140 payment_secret.write(writer)?;
143 &Event::PaymentSent { ref payment_preimage } => {
145 payment_preimage.write(writer)?;
147 &Event::PaymentFailed { ref payment_hash, ref rejected_by_dest,
154 payment_hash.write(writer)?;
155 rejected_by_dest.write(writer)?;
157 error_code.write(writer)?;
159 error_data.write(writer)?;
161 &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
163 // We don't write the time_fordwardable out at all, as we presume when the user
164 // deserializes us at least that much time has elapsed.
166 &Event::SpendableOutputs { ref outputs } => {
168 (outputs.len() as u64).write(writer)?;
169 for output in outputs.iter() {
170 output.write(writer)?;
177 impl MaybeReadable for Event {
178 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
179 match Readable::read(reader)? {
181 1u8 => Ok(Some(Event::FundingBroadcastSafe {
182 funding_txo: Readable::read(reader)?,
183 user_channel_id: Readable::read(reader)?,
185 2u8 => Ok(Some(Event::PaymentReceived {
186 payment_hash: Readable::read(reader)?,
187 payment_secret: Readable::read(reader)?,
188 amt: Readable::read(reader)?,
190 3u8 => Ok(Some(Event::PaymentSent {
191 payment_preimage: Readable::read(reader)?,
193 4u8 => Ok(Some(Event::PaymentFailed {
194 payment_hash: Readable::read(reader)?,
195 rejected_by_dest: Readable::read(reader)?,
197 error_code: Readable::read(reader)?,
199 error_data: Readable::read(reader)?,
201 5u8 => Ok(Some(Event::PendingHTLCsForwardable {
202 time_forwardable: Duration::from_secs(0)
205 let outputs_len: u64 = Readable::read(reader)?;
206 let mut outputs = Vec::new();
207 for _ in 0..outputs_len {
208 outputs.push(Readable::read(reader)?);
210 Ok(Some(Event::SpendableOutputs { outputs }))
212 _ => Err(msgs::DecodeError::InvalidValue)
217 /// An event generated by ChannelManager which indicates a message should be sent to a peer (or
218 /// broadcast to most peers).
219 /// These events are handled by PeerManager::process_events if you are using a PeerManager.
221 pub enum MessageSendEvent {
222 /// Used to indicate that we've accepted a channel open and should send the accept_channel
223 /// message provided to the given peer.
225 /// The node_id of the node which should receive this message
227 /// The message which should be sent.
228 msg: msgs::AcceptChannel,
230 /// Used to indicate that we've initiated a channel open and should send the open_channel
231 /// message provided to the given peer.
233 /// The node_id of the node which should receive this message
235 /// The message which should be sent.
236 msg: msgs::OpenChannel,
238 /// Used to indicate that a funding_created message should be sent to the peer with the given node_id.
240 /// The node_id of the node which should receive this message
242 /// The message which should be sent.
243 msg: msgs::FundingCreated,
245 /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id.
247 /// The node_id of the node which should receive this message
249 /// The message which should be sent.
250 msg: msgs::FundingSigned,
252 /// Used to indicate that a funding_locked message should be sent to the peer with the given node_id.
254 /// The node_id of the node which should receive these message(s)
256 /// The funding_locked message which should be sent.
257 msg: msgs::FundingLocked,
259 /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
260 SendAnnouncementSignatures {
261 /// The node_id of the node which should receive these message(s)
263 /// The announcement_signatures message which should be sent.
264 msg: msgs::AnnouncementSignatures,
266 /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed
267 /// message should be sent to the peer with the given node_id.
269 /// The node_id of the node which should receive these message(s)
271 /// The update messages which should be sent. ALL messages in the struct should be sent!
272 updates: msgs::CommitmentUpdate,
274 /// Used to indicate that a revoke_and_ack message should be sent to the peer with the given node_id.
276 /// The node_id of the node which should receive this message
278 /// The message which should be sent.
279 msg: msgs::RevokeAndACK,
281 /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id.
283 /// The node_id of the node which should receive this message
285 /// The message which should be sent.
286 msg: msgs::ClosingSigned,
288 /// Used to indicate that a shutdown message should be sent to the peer with the given node_id.
290 /// The node_id of the node which should receive this message
292 /// The message which should be sent.
295 /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id.
296 SendChannelReestablish {
297 /// The node_id of the node which should receive this message
299 /// The message which should be sent.
300 msg: msgs::ChannelReestablish,
302 /// Used to indicate that a channel_announcement and channel_update should be broadcast to all
303 /// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
305 /// Note that after doing so, you very likely (unless you did so very recently) want to call
306 /// ChannelManager::broadcast_node_announcement to trigger a BroadcastNodeAnnouncement event.
307 /// This ensures that any nodes which see our channel_announcement also have a relevant
308 /// node_announcement, including relevant feature flags which may be important for routing
309 /// through or to us.
310 BroadcastChannelAnnouncement {
311 /// The channel_announcement which should be sent.
312 msg: msgs::ChannelAnnouncement,
313 /// The followup channel_update which should be sent.
314 update_msg: msgs::ChannelUpdate,
316 /// Used to indicate that a node_announcement should be broadcast to all peers.
317 BroadcastNodeAnnouncement {
318 /// The node_announcement which should be sent.
319 msg: msgs::NodeAnnouncement,
321 /// Used to indicate that a channel_update should be broadcast to all peers.
322 BroadcastChannelUpdate {
323 /// The channel_update which should be sent.
324 msg: msgs::ChannelUpdate,
326 /// Broadcast an error downstream to be handled
328 /// The node_id of the node which should receive this message
330 /// The action which should be taken.
331 action: msgs::ErrorAction
333 /// When a payment fails we may receive updates back from the hop where it failed. In such
334 /// cases this event is generated so that we can inform the router of this information.
335 PaymentFailureNetworkUpdate {
336 /// The channel/node update which should be sent to router
337 update: msgs::HTLCFailChannelUpdate,
341 /// A trait indicating an object may generate message send events
342 pub trait MessageSendEventsProvider {
343 /// Gets the list of pending events which were generated by previous actions, clearing the list
345 fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
348 /// A trait indicating an object may generate events
349 pub trait EventsProvider {
350 /// Gets the list of pending events which were generated by previous actions, clearing the list
352 fn get_and_clear_pending_events(&self) -> Vec<Event>;