git.bitcoin.ninja Git - rust-lightning/blob - lightning/src/util/events.rs

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   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
   8 // licenses.
   9
  10 //! Events are returned from various bits in the library which indicate some action must be taken
  11 //! by the client.
  12 //!
  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
  15 //! few other things.
  16
  17 use crate::chain::keysinterface::SpendableOutputDescriptor;
  18 #[cfg(anchors)]
  19 use crate::ln::chan_utils::HTLCOutputInCommitment;
  20 use crate::ln::channelmanager::PaymentId;
  21 use crate::ln::channel::FUNDING_CONF_DEADLINE_BLOCKS;
  22 use crate::ln::features::ChannelTypeFeatures;
  23 use crate::ln::msgs;
  24 use crate::ln::msgs::DecodeError;
  25 use crate::ln::{PaymentPreimage, PaymentHash, PaymentSecret};
  26 use crate::routing::gossip::NetworkUpdate;
  27 use crate::util::ser::{BigSize, FixedLengthReader, Writeable, Writer, MaybeReadable, Readable, WithoutLength, OptionDeserWrapper};
  28 use crate::routing::router::{RouteHop, RouteParameters};
  29
  30 use bitcoin::{PackedLockTime, Transaction};
  31 #[cfg(anchors)]
  32 use bitcoin::OutPoint;
  33 use bitcoin::blockdata::script::Script;
  34 use bitcoin::hashes::Hash;
  35 use bitcoin::hashes::sha256::Hash as Sha256;
  36 use bitcoin::secp256k1::PublicKey;
  37 use crate::io;
  38 use crate::prelude::*;
  39 use core::time::Duration;
  40 use core::ops::Deref;
  41 use crate::sync::Arc;
  42
  43 /// Some information provided on receipt of payment depends on whether the payment received is a
  44 /// spontaneous payment or a "conventional" lightning payment that's paying an invoice.
  45 #[derive(Clone, Debug)]
  46 pub enum PaymentPurpose {
  47         /// Information for receiving a payment that we generated an invoice for.
  48         InvoicePayment {
  49                 /// The preimage to the payment_hash, if the payment hash (and secret) were fetched via
  50                 /// [`ChannelManager::create_inbound_payment`]. If provided, this can be handed directly to
  51                 /// [`ChannelManager::claim_funds`].
  52                 ///
  53                 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
  54                 /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
  55                 payment_preimage: Option<PaymentPreimage>,
  56                 /// The "payment secret". This authenticates the sender to the recipient, preventing a
  57                 /// number of deanonymization attacks during the routing process.
  58                 /// It is provided here for your reference, however its accuracy is enforced directly by
  59                 /// [`ChannelManager`] using the values you previously provided to
  60                 /// [`ChannelManager::create_inbound_payment`] or
  61                 /// [`ChannelManager::create_inbound_payment_for_hash`].
  62                 ///
  63                 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
  64                 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
  65                 /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
  66                 payment_secret: PaymentSecret,
  67         },
  68         /// Because this is a spontaneous payment, the payer generated their own preimage rather than us
  69         /// (the payee) providing a preimage.
  70         SpontaneousPayment(PaymentPreimage),
  71 }
  72
  73 impl_writeable_tlv_based_enum!(PaymentPurpose,
  74         (0, InvoicePayment) => {
  75                 (0, payment_preimage, option),
  76                 (2, payment_secret, required),
  77         };
  78         (2, SpontaneousPayment)
  79 );
  80
  81 #[derive(Clone, Debug, PartialEq, Eq)]
  82 /// The reason the channel was closed. See individual variants more details.
  83 pub enum ClosureReason {
  84         /// Closure generated from receiving a peer error message.
  85         ///
  86         /// Our counterparty may have broadcasted their latest commitment state, and we have
  87         /// as well.
  88         CounterpartyForceClosed {
  89                 /// The error which the peer sent us.
  90                 ///
  91                 /// The string should be sanitized before it is used (e.g emitted to logs
  92                 /// or printed to stdout). Otherwise, a well crafted error message may exploit
  93                 /// a security vulnerability in the terminal emulator or the logging subsystem.
  94                 peer_msg: String,
  95         },
  96         /// Closure generated from [`ChannelManager::force_close_channel`], called by the user.
  97         ///
  98         /// [`ChannelManager::force_close_channel`]: crate::ln::channelmanager::ChannelManager::force_close_channel.
  99         HolderForceClosed,
 100         /// The channel was closed after negotiating a cooperative close and we've now broadcasted
 101         /// the cooperative close transaction. Note the shutdown may have been initiated by us.
 102         //TODO: split between CounterpartyInitiated/LocallyInitiated
 103         CooperativeClosure,
 104         /// A commitment transaction was confirmed on chain, closing the channel. Most likely this
 105         /// commitment transaction came from our counterparty, but it may also have come from
 106         /// a copy of our own `ChannelMonitor`.
 107         CommitmentTxConfirmed,
 108         /// The funding transaction failed to confirm in a timely manner on an inbound channel.
 109         FundingTimedOut,
 110         /// Closure generated from processing an event, likely a HTLC forward/relay/reception.
 111         ProcessingError {
 112                 /// A developer-readable error message which we generated.
 113                 err: String,
 114         },
 115         /// The peer disconnected prior to funding completing. In this case the spec mandates that we
 116         /// forget the channel entirely - we can attempt again if the peer reconnects.
 117         ///
 118         /// This includes cases where we restarted prior to funding completion, including prior to the
 119         /// initial [`ChannelMonitor`] persistence completing.
 120         ///
 121         /// In LDK versions prior to 0.0.107 this could also occur if we were unable to connect to the
 122         /// peer because of mutual incompatibility between us and our channel counterparty.
 123         ///
 124         /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
 125         DisconnectedPeer,
 126         /// Closure generated from `ChannelManager::read` if the [`ChannelMonitor`] is newer than
 127         /// the [`ChannelManager`] deserialized.
 128         ///
 129         /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
 130         /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 131         OutdatedChannelManager
 132 }
 133
 134 impl core::fmt::Display for ClosureReason {
 135         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
 136                 f.write_str("Channel closed because ")?;
 137                 match self {
 138                         ClosureReason::CounterpartyForceClosed { peer_msg } => {
 139                                 f.write_str("counterparty force-closed with message ")?;
 140                                 f.write_str(&peer_msg)
 141                         },
 142                         ClosureReason::HolderForceClosed => f.write_str("user manually force-closed the channel"),
 143                         ClosureReason::CooperativeClosure => f.write_str("the channel was cooperatively closed"),
 144                         ClosureReason::CommitmentTxConfirmed => f.write_str("commitment or closing transaction was confirmed on chain."),
 145                         ClosureReason::FundingTimedOut => write!(f, "funding transaction failed to confirm within {} blocks", FUNDING_CONF_DEADLINE_BLOCKS),
 146                         ClosureReason::ProcessingError { err } => {
 147                                 f.write_str("of an exception: ")?;
 148                                 f.write_str(&err)
 149                         },
 150                         ClosureReason::DisconnectedPeer => f.write_str("the peer disconnected prior to the channel being funded"),
 151                         ClosureReason::OutdatedChannelManager => f.write_str("the ChannelManager read from disk was stale compared to ChannelMonitor(s)"),
 152                 }
 153         }
 154 }
 155
 156 impl_writeable_tlv_based_enum_upgradable!(ClosureReason,
 157         (0, CounterpartyForceClosed) => { (1, peer_msg, required) },
 158         (1, FundingTimedOut) => {},
 159         (2, HolderForceClosed) => {},
 160         (6, CommitmentTxConfirmed) => {},
 161         (4, CooperativeClosure) => {},
 162         (8, ProcessingError) => { (1, err, required) },
 163         (10, DisconnectedPeer) => {},
 164         (12, OutdatedChannelManager) => {},
 165 );
 166
 167 /// Intended destination of a failed HTLC as indicated in [`Event::HTLCHandlingFailed`].
 168 #[derive(Clone, Debug, PartialEq, Eq)]
 169 pub enum HTLCDestination {
 170         /// We tried forwarding to a channel but failed to do so. An example of such an instance is when
 171         /// there is insufficient capacity in our outbound channel.
 172         NextHopChannel {
 173                 /// The `node_id` of the next node. For backwards compatibility, this field is
 174                 /// marked as optional, versions prior to 0.0.110 may not always be able to provide
 175                 /// counterparty node information.
 176                 node_id: Option<PublicKey>,
 177                 /// The outgoing `channel_id` between us and the next node.
 178                 channel_id: [u8; 32],
 179         },
 180         /// Scenario where we are unsure of the next node to forward the HTLC to.
 181         UnknownNextHop {
 182                 /// Short channel id we are requesting to forward an HTLC to.
 183                 requested_forward_scid: u64,
 184         },
 185         /// Failure scenario where an HTLC may have been forwarded to be intended for us,
 186         /// but is invalid for some reason, so we reject it.
 187         ///
 188         /// Some of the reasons may include:
 189         /// * HTLC Timeouts
 190         /// * Expected MPP amount to claim does not equal HTLC total
 191         /// * Claimable amount does not match expected amount
 192         FailedPayment {
 193                 /// The payment hash of the payment we attempted to process.
 194                 payment_hash: PaymentHash
 195         },
 196 }
 197
 198 impl_writeable_tlv_based_enum_upgradable!(HTLCDestination,
 199         (0, NextHopChannel) => {
 200                 (0, node_id, required),
 201                 (2, channel_id, required),
 202         },
 203         (2, UnknownNextHop) => {
 204                 (0, requested_forward_scid, required),
 205         },
 206         (4, FailedPayment) => {
 207                 (0, payment_hash, required),
 208         }
 209 );
 210
 211 #[cfg(anchors)]
 212 /// A descriptor used to sign for a commitment transaction's anchor output.
 213 #[derive(Clone, Debug)]
 214 pub struct AnchorDescriptor {
 215         /// A unique identifier used along with `channel_value_satoshis` to re-derive the
 216         /// [`InMemorySigner`] required to sign `input`.
 217         ///
 218         /// [`InMemorySigner`]: crate::chain::keysinterface::InMemorySigner
 219         pub channel_keys_id: [u8; 32],
 220         /// The value in satoshis of the channel we're attempting to spend the anchor output of. This is
 221         /// used along with `channel_keys_id` to re-derive the [`InMemorySigner`] required to sign
 222         /// `input`.
 223         ///
 224         /// [`InMemorySigner`]: crate::chain::keysinterface::InMemorySigner
 225         pub channel_value_satoshis: u64,
 226         /// The transaction input's outpoint corresponding to the commitment transaction's anchor
 227         /// output.
 228         pub outpoint: OutPoint,
 229 }
 230
 231 #[cfg(anchors)]
 232 /// Represents the different types of transactions, originating from LDK, to be bumped.
 233 #[derive(Clone, Debug)]
 234 pub enum BumpTransactionEvent {
 235         /// Indicates that a channel featuring anchor outputs is to be closed by broadcasting the local
 236         /// commitment transaction. Since commitment transactions have a static feerate pre-agreed upon,
 237         /// they may need additional fees to be attached through a child transaction using the popular
 238         /// [Child-Pays-For-Parent](https://bitcoinops.org/en/topics/cpfp) fee bumping technique. This
 239         /// child transaction must include the anchor input described within `anchor_descriptor` along
 240         /// with additional inputs to meet the target feerate. Failure to meet the target feerate
 241         /// decreases the confirmation odds of the transaction package (which includes the commitment
 242         /// and child anchor transactions), possibly resulting in a loss of funds. Once the transaction
 243         /// is constructed, it must be fully signed for and broadcasted by the consumer of the event
 244         /// along with the `commitment_tx` enclosed. Note that the `commitment_tx` must always be
 245         /// broadcast first, as the child anchor transaction depends on it.
 246         ///
 247         /// The consumer should be able to sign for any of the additional inputs included within the
 248         /// child anchor transaction. To sign its anchor input, an [`InMemorySigner`] should be
 249         /// re-derived through [`KeysManager::derive_channel_keys`] with the help of
 250         /// [`AnchorDescriptor::channel_keys_id`] and [`AnchorDescriptor::channel_value_satoshis`].
 251         ///
 252         /// It is possible to receive more than one instance of this event if a valid child anchor
 253         /// transaction is never broadcast or is but not with a sufficient fee to be mined. Care should
 254         /// be taken by the consumer of the event to ensure any future iterations of the child anchor
 255         /// transaction adhere to the [Replace-By-Fee
 256         /// rules](https://github.com/bitcoin/bitcoin/blob/master/doc/policy/mempool-replacements.md)
 257         /// for fee bumps to be accepted into the mempool, and eventually the chain. As the frequency of
 258         /// these events is not user-controlled, users may ignore/drop the event if they are no longer
 259         /// able to commit external confirmed funds to the child anchor transaction.
 260         ///
 261         /// The set of `pending_htlcs` on the commitment transaction to be broadcast can be inspected to
 262         /// determine whether a significant portion of the channel's funds are allocated to HTLCs,
 263         /// enabling users to make their own decisions regarding the importance of the commitment
 264         /// transaction's confirmation. Note that this is not required, but simply exists as an option
 265         /// for users to override LDK's behavior. On commitments with no HTLCs (indicated by those with
 266         /// an empty `pending_htlcs`), confirmation of the commitment transaction can be considered to
 267         /// be not urgent.
 268         ///
 269         /// [`InMemorySigner`]: crate::chain::keysinterface::InMemorySigner
 270         /// [`KeysManager::derive_channel_keys`]: crate::chain::keysinterface::KeysManager::derive_channel_keys
 271         ChannelClose {
 272                 /// The target feerate that the transaction package, which consists of the commitment
 273                 /// transaction and the to-be-crafted child anchor transaction, must meet.
 274                 package_target_feerate_sat_per_1000_weight: u32,
 275                 /// The channel's commitment transaction to bump the fee of. This transaction should be
 276                 /// broadcast along with the anchor transaction constructed as a result of consuming this
 277                 /// event.
 278                 commitment_tx: Transaction,
 279                 /// The absolute fee in satoshis of the commitment transaction. This can be used along the
 280                 /// with weight of the commitment transaction to determine its feerate.
 281                 commitment_tx_fee_satoshis: u64,
 282                 /// The descriptor to sign the anchor input of the anchor transaction constructed as a
 283                 /// result of consuming this event.
 284                 anchor_descriptor: AnchorDescriptor,
 285                 /// The set of pending HTLCs on the commitment transaction that need to be resolved once the
 286                 /// commitment transaction confirms.
 287                 pending_htlcs: Vec<HTLCOutputInCommitment>,
 288         },
 289 }
 290
 291 /// An Event which you should probably take some action in response to.
 292 ///
 293 /// Note that while Writeable and Readable are implemented for Event, you probably shouldn't use
 294 /// them directly as they don't round-trip exactly (for example FundingGenerationReady is never
 295 /// written as it makes no sense to respond to it after reconnecting to peers).
 296 #[derive(Clone, Debug)]
 297 pub enum Event {
 298         /// Used to indicate that the client should generate a funding transaction with the given
 299         /// parameters and then call [`ChannelManager::funding_transaction_generated`].
 300         /// Generated in [`ChannelManager`] message handling.
 301         /// Note that *all inputs* in the funding transaction must spend SegWit outputs or your
 302         /// counterparty can steal your funds!
 303         ///
 304         /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 305         /// [`ChannelManager::funding_transaction_generated`]: crate::ln::channelmanager::ChannelManager::funding_transaction_generated
 306         FundingGenerationReady {
 307                 /// The random channel_id we picked which you'll need to pass into
 308                 /// [`ChannelManager::funding_transaction_generated`].
 309                 ///
 310                 /// [`ChannelManager::funding_transaction_generated`]: crate::ln::channelmanager::ChannelManager::funding_transaction_generated
 311                 temporary_channel_id: [u8; 32],
 312                 /// The counterparty's node_id, which you'll need to pass back into
 313                 /// [`ChannelManager::funding_transaction_generated`].
 314                 ///
 315                 /// [`ChannelManager::funding_transaction_generated`]: crate::ln::channelmanager::ChannelManager::funding_transaction_generated
 316                 counterparty_node_id: PublicKey,
 317                 /// The value, in satoshis, that the output should have.
 318                 channel_value_satoshis: u64,
 319                 /// The script which should be used in the transaction output.
 320                 output_script: Script,
 321                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`], or 0 for
 322                 /// an inbound channel.
 323                 ///
 324                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
 325                 user_channel_id: u64,
 326         },
 327         /// Indicates we've received (an offer of) money! Just gotta dig out that payment preimage and
 328         /// feed it to [`ChannelManager::claim_funds`] to get it....
 329         ///
 330         /// Note that if the preimage is not known, you should call
 331         /// [`ChannelManager::fail_htlc_backwards`] to free up resources for this HTLC and avoid
 332         /// network congestion.
 333         /// If you fail to call either [`ChannelManager::claim_funds`] or
 334         /// [`ChannelManager::fail_htlc_backwards`] within the HTLC's timeout, the HTLC will be
 335         /// automatically failed.
 336         ///
 337         /// # Note
 338         /// LDK will not stop an inbound payment from being paid multiple times, so multiple
 339         /// `PaymentReceived` events may be generated for the same payment.
 340         ///
 341         /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
 342         /// [`ChannelManager::fail_htlc_backwards`]: crate::ln::channelmanager::ChannelManager::fail_htlc_backwards
 343         PaymentReceived {
 344                 /// The hash for which the preimage should be handed to the ChannelManager. Note that LDK will
 345                 /// not stop you from registering duplicate payment hashes for inbound payments.
 346                 payment_hash: PaymentHash,
 347                 /// The value, in thousandths of a satoshi, that this payment is for.
 348                 amount_msat: u64,
 349                 /// Information for claiming this received payment, based on whether the purpose of the
 350                 /// payment is to pay an invoice or to send a spontaneous payment.
 351                 purpose: PaymentPurpose,
 352         },
 353         /// Indicates a payment has been claimed and we've received money!
 354         ///
 355         /// This most likely occurs when [`ChannelManager::claim_funds`] has been called in response
 356         /// to an [`Event::PaymentReceived`]. However, if we previously crashed during a
 357         /// [`ChannelManager::claim_funds`] call you may see this event without a corresponding
 358         /// [`Event::PaymentReceived`] event.
 359         ///
 360         /// # Note
 361         /// LDK will not stop an inbound payment from being paid multiple times, so multiple
 362         /// `PaymentReceived` events may be generated for the same payment. If you then call
 363         /// [`ChannelManager::claim_funds`] twice for the same [`Event::PaymentReceived`] you may get
 364         /// multiple `PaymentClaimed` events.
 365         ///
 366         /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
 367         PaymentClaimed {
 368                 /// The payment hash of the claimed payment. Note that LDK will not stop you from
 369                 /// registering duplicate payment hashes for inbound payments.
 370                 payment_hash: PaymentHash,
 371                 /// The value, in thousandths of a satoshi, that this payment is for.
 372                 amount_msat: u64,
 373                 /// The purpose of this claimed payment, i.e. whether the payment was for an invoice or a
 374                 /// spontaneous payment.
 375                 purpose: PaymentPurpose,
 376         },
 377         /// Indicates an outbound payment we made succeeded (i.e. it made it all the way to its target
 378         /// and we got back the payment preimage for it).
 379         ///
 380         /// Note for MPP payments: in rare cases, this event may be preceded by a `PaymentPathFailed`
 381         /// event. In this situation, you SHOULD treat this payment as having succeeded.
 382         PaymentSent {
 383                 /// The id returned by [`ChannelManager::send_payment`] and used with
 384                 /// [`ChannelManager::retry_payment`].
 385                 ///
 386                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 387                 /// [`ChannelManager::retry_payment`]: crate::ln::channelmanager::ChannelManager::retry_payment
 388                 payment_id: Option<PaymentId>,
 389                 /// The preimage to the hash given to ChannelManager::send_payment.
 390                 /// Note that this serves as a payment receipt, if you wish to have such a thing, you must
 391                 /// store it somehow!
 392                 payment_preimage: PaymentPreimage,
 393                 /// The hash that was given to [`ChannelManager::send_payment`].
 394                 ///
 395                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 396                 payment_hash: PaymentHash,
 397                 /// The total fee which was spent at intermediate hops in this payment, across all paths.
 398                 ///
 399                 /// Note that, like [`Route::get_total_fees`] this does *not* include any potential
 400                 /// overpayment to the recipient node.
 401                 ///
 402                 /// If the recipient or an intermediate node misbehaves and gives us free money, this may
 403                 /// overstate the amount paid, though this is unlikely.
 404                 ///
 405                 /// [`Route::get_total_fees`]: crate::routing::router::Route::get_total_fees
 406                 fee_paid_msat: Option<u64>,
 407         },
 408         /// Indicates an outbound payment failed. Individual [`Event::PaymentPathFailed`] events
 409         /// provide failure information for each MPP part in the payment.
 410         ///
 411         /// This event is provided once there are no further pending HTLCs for the payment and the
 412         /// payment is no longer retryable due to [`ChannelManager::abandon_payment`] having been
 413         /// called for the corresponding payment.
 414         ///
 415         /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 416         PaymentFailed {
 417                 /// The id returned by [`ChannelManager::send_payment`] and used with
 418                 /// [`ChannelManager::retry_payment`] and [`ChannelManager::abandon_payment`].
 419                 ///
 420                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 421                 /// [`ChannelManager::retry_payment`]: crate::ln::channelmanager::ChannelManager::retry_payment
 422                 /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 423                 payment_id: PaymentId,
 424                 /// The hash that was given to [`ChannelManager::send_payment`].
 425                 ///
 426                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 427                 payment_hash: PaymentHash,
 428         },
 429         /// Indicates that a path for an outbound payment was successful.
 430         ///
 431         /// Always generated after [`Event::PaymentSent`] and thus useful for scoring channels. See
 432         /// [`Event::PaymentSent`] for obtaining the payment preimage.
 433         PaymentPathSuccessful {
 434                 /// The id returned by [`ChannelManager::send_payment`] and used with
 435                 /// [`ChannelManager::retry_payment`].
 436                 ///
 437                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 438                 /// [`ChannelManager::retry_payment`]: crate::ln::channelmanager::ChannelManager::retry_payment
 439                 payment_id: PaymentId,
 440                 /// The hash that was given to [`ChannelManager::send_payment`].
 441                 ///
 442                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 443                 payment_hash: Option<PaymentHash>,
 444                 /// The payment path that was successful.
 445                 ///
 446                 /// May contain a closed channel if the HTLC sent along the path was fulfilled on chain.
 447                 path: Vec<RouteHop>,
 448         },
 449         /// Indicates an outbound HTLC we sent failed. Probably some intermediary node dropped
 450         /// something. You may wish to retry with a different route.
 451         ///
 452         /// If you have given up retrying this payment and wish to fail it, you MUST call
 453         /// [`ChannelManager::abandon_payment`] at least once for a given [`PaymentId`] or memory
 454         /// related to payment tracking will leak.
 455         ///
 456         /// Note that this does *not* indicate that all paths for an MPP payment have failed, see
 457         /// [`Event::PaymentFailed`] and [`all_paths_failed`].
 458         ///
 459         /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 460         /// [`all_paths_failed`]: Self::PaymentPathFailed::all_paths_failed
 461         PaymentPathFailed {
 462                 /// The id returned by [`ChannelManager::send_payment`] and used with
 463                 /// [`ChannelManager::retry_payment`] and [`ChannelManager::abandon_payment`].
 464                 ///
 465                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 466                 /// [`ChannelManager::retry_payment`]: crate::ln::channelmanager::ChannelManager::retry_payment
 467                 /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 468                 payment_id: Option<PaymentId>,
 469                 /// The hash that was given to [`ChannelManager::send_payment`].
 470                 ///
 471                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 472                 payment_hash: PaymentHash,
 473                 /// Indicates the payment was rejected for some reason by the recipient. This implies that
 474                 /// the payment has failed, not just the route in question. If this is not set, you may
 475                 /// retry the payment via a different route.
 476                 payment_failed_permanently: bool,
 477                 /// Any failure information conveyed via the Onion return packet by a node along the failed
 478                 /// payment route.
 479                 ///
 480                 /// Should be applied to the [`NetworkGraph`] so that routing decisions can take into
 481                 /// account the update.
 482                 ///
 483                 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
 484                 network_update: Option<NetworkUpdate>,
 485                 /// For both single-path and multi-path payments, this is set if all paths of the payment have
 486                 /// failed. This will be set to false if (1) this is an MPP payment and (2) other parts of the
 487                 /// larger MPP payment were still in flight when this event was generated.
 488                 ///
 489                 /// Note that if you are retrying individual MPP parts, using this value to determine if a
 490                 /// payment has fully failed is race-y. Because multiple failures can happen prior to events
 491                 /// being processed, you may retry in response to a first failure, with a second failure
 492                 /// (with `all_paths_failed` set) still pending. Then, when the second failure is processed
 493                 /// you will see `all_paths_failed` set even though the retry of the first failure still
 494                 /// has an associated in-flight HTLC. See (1) for an example of such a failure.
 495                 ///
 496                 /// If you wish to retry individual MPP parts and learn when a payment has failed, you must
 497                 /// call [`ChannelManager::abandon_payment`] and wait for a [`Event::PaymentFailed`] event.
 498                 ///
 499                 /// (1) <https://github.com/lightningdevkit/rust-lightning/issues/1164>
 500                 ///
 501                 /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 502                 all_paths_failed: bool,
 503                 /// The payment path that failed.
 504                 path: Vec<RouteHop>,
 505                 /// The channel responsible for the failed payment path.
 506                 ///
 507                 /// Note that for route hints or for the first hop in a path this may be an SCID alias and
 508                 /// may not refer to a channel in the public network graph. These aliases may also collide
 509                 /// with channels in the public network graph.
 510                 ///
 511                 /// If this is `Some`, then the corresponding channel should be avoided when the payment is
 512                 /// retried. May be `None` for older [`Event`] serializations.
 513                 short_channel_id: Option<u64>,
 514                 /// Parameters needed to compute a new [`Route`] when retrying the failed payment path.
 515                 ///
 516                 /// See [`find_route`] for details.
 517                 ///
 518                 /// [`Route`]: crate::routing::router::Route
 519                 /// [`find_route`]: crate::routing::router::find_route
 520                 retry: Option<RouteParameters>,
 521 #[cfg(test)]
 522                 error_code: Option<u16>,
 523 #[cfg(test)]
 524                 error_data: Option<Vec<u8>>,
 525         },
 526         /// Indicates that a probe payment we sent returned successful, i.e., only failed at the destination.
 527         ProbeSuccessful {
 528                 /// The id returned by [`ChannelManager::send_probe`].
 529                 ///
 530                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
 531                 payment_id: PaymentId,
 532                 /// The hash generated by [`ChannelManager::send_probe`].
 533                 ///
 534                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
 535                 payment_hash: PaymentHash,
 536                 /// The payment path that was successful.
 537                 path: Vec<RouteHop>,
 538         },
 539         /// Indicates that a probe payment we sent failed at an intermediary node on the path.
 540         ProbeFailed {
 541                 /// The id returned by [`ChannelManager::send_probe`].
 542                 ///
 543                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
 544                 payment_id: PaymentId,
 545                 /// The hash generated by [`ChannelManager::send_probe`].
 546                 ///
 547                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
 548                 payment_hash: PaymentHash,
 549                 /// The payment path that failed.
 550                 path: Vec<RouteHop>,
 551                 /// The channel responsible for the failed probe.
 552                 ///
 553                 /// Note that for route hints or for the first hop in a path this may be an SCID alias and
 554                 /// may not refer to a channel in the public network graph. These aliases may also collide
 555                 /// with channels in the public network graph.
 556                 short_channel_id: Option<u64>,
 557         },
 558         /// Used to indicate that [`ChannelManager::process_pending_htlc_forwards`] should be called at
 559         /// a time in the future.
 560         ///
 561         /// [`ChannelManager::process_pending_htlc_forwards`]: crate::ln::channelmanager::ChannelManager::process_pending_htlc_forwards
 562         PendingHTLCsForwardable {
 563                 /// The minimum amount of time that should be waited prior to calling
 564                 /// process_pending_htlc_forwards. To increase the effort required to correlate payments,
 565                 /// you should wait a random amount of time in roughly the range (now + time_forwardable,
 566                 /// now + 5*time_forwardable).
 567                 time_forwardable: Duration,
 568         },
 569         /// Used to indicate that an output which you should know how to spend was confirmed on chain
 570         /// and is now spendable.
 571         /// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
 572         /// counterparty spending them due to some kind of timeout. Thus, you need to store them
 573         /// somewhere and spend them when you create on-chain transactions.
 574         SpendableOutputs {
 575                 /// The outputs which you should store as spendable by you.
 576                 outputs: Vec<SpendableOutputDescriptor>,
 577         },
 578         /// This event is generated when a payment has been successfully forwarded through us and a
 579         /// forwarding fee earned.
 580         PaymentForwarded {
 581                 /// The incoming channel between the previous node and us. This is only `None` for events
 582                 /// generated or serialized by versions prior to 0.0.107.
 583                 prev_channel_id: Option<[u8; 32]>,
 584                 /// The outgoing channel between the next node and us. This is only `None` for events
 585                 /// generated or serialized by versions prior to 0.0.107.
 586                 next_channel_id: Option<[u8; 32]>,
 587                 /// The fee, in milli-satoshis, which was earned as a result of the payment.
 588                 ///
 589                 /// Note that if we force-closed the channel over which we forwarded an HTLC while the HTLC
 590                 /// was pending, the amount the next hop claimed will have been rounded down to the nearest
 591                 /// whole satoshi. Thus, the fee calculated here may be higher than expected as we still
 592                 /// claimed the full value in millisatoshis from the source. In this case,
 593                 /// `claim_from_onchain_tx` will be set.
 594                 ///
 595                 /// If the channel which sent us the payment has been force-closed, we will claim the funds
 596                 /// via an on-chain transaction. In that case we do not yet know the on-chain transaction
 597                 /// fees which we will spend and will instead set this to `None`. It is possible duplicate
 598                 /// `PaymentForwarded` events are generated for the same payment iff `fee_earned_msat` is
 599                 /// `None`.
 600                 fee_earned_msat: Option<u64>,
 601                 /// If this is `true`, the forwarded HTLC was claimed by our counterparty via an on-chain
 602                 /// transaction.
 603                 claim_from_onchain_tx: bool,
 604         },
 605         /// Used to indicate that a channel with the given `channel_id` is ready to
 606         /// be used. This event is emitted either when the funding transaction has been confirmed
 607         /// on-chain, or, in case of a 0conf channel, when both parties have confirmed the channel
 608         /// establishment.
 609         ChannelReady {
 610                 /// The channel_id of the channel that is ready.
 611                 channel_id: [u8; 32],
 612                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
 613                 /// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
 614                 /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
 615                 /// `user_channel_id` will be 0 for an inbound channel.
 616                 ///
 617                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
 618                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 619                 /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
 620                 user_channel_id: u64,
 621                 /// The node_id of the channel counterparty.
 622                 counterparty_node_id: PublicKey,
 623                 /// The features that this channel will operate with.
 624                 channel_type: ChannelTypeFeatures,
 625         },
 626         /// Used to indicate that a previously opened channel with the given `channel_id` is in the
 627         /// process of closure.
 628         ChannelClosed  {
 629                 /// The channel_id of the channel which has been closed. Note that on-chain transactions
 630                 /// resolving the channel are likely still awaiting confirmation.
 631                 channel_id: [u8; 32],
 632                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
 633                 /// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
 634                 /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
 635                 /// `user_channel_id` will be 0 for an inbound channel.
 636                 /// This will always be zero for objects serialized with LDK versions prior to 0.0.102.
 637                 ///
 638                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
 639                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 640                 /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
 641                 user_channel_id: u64,
 642                 /// The reason the channel was closed.
 643                 reason: ClosureReason
 644         },
 645         /// Used to indicate to the user that they can abandon the funding transaction and recycle the
 646         /// inputs for another purpose.
 647         DiscardFunding {
 648                 /// The channel_id of the channel which has been closed.
 649                 channel_id: [u8; 32],
 650                 /// The full transaction received from the user
 651                 transaction: Transaction
 652         },
 653         /// Indicates a request to open a new channel by a peer.
 654         ///
 655         /// To accept the request, call [`ChannelManager::accept_inbound_channel`]. To reject the
 656         /// request, call [`ChannelManager::force_close_without_broadcasting_txn`].
 657         ///
 658         /// The event is only triggered when a new open channel request is received and the
 659         /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true.
 660         ///
 661         /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 662         /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
 663         /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
 664         OpenChannelRequest {
 665                 /// The temporary channel ID of the channel requested to be opened.
 666                 ///
 667                 /// When responding to the request, the `temporary_channel_id` should be passed
 668                 /// back to the ChannelManager through [`ChannelManager::accept_inbound_channel`] to accept,
 669                 /// or through [`ChannelManager::force_close_without_broadcasting_txn`] to reject.
 670                 ///
 671                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 672                 /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
 673                 temporary_channel_id: [u8; 32],
 674                 /// The node_id of the counterparty requesting to open the channel.
 675                 ///
 676                 /// When responding to the request, the `counterparty_node_id` should be passed
 677                 /// back to the `ChannelManager` through [`ChannelManager::accept_inbound_channel`] to
 678                 /// accept the request, or through [`ChannelManager::force_close_without_broadcasting_txn`] to reject the
 679                 /// request.
 680                 ///
 681                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 682                 /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
 683                 counterparty_node_id: PublicKey,
 684                 /// The channel value of the requested channel.
 685                 funding_satoshis: u64,
 686                 /// Our starting balance in the channel if the request is accepted, in milli-satoshi.
 687                 push_msat: u64,
 688                 /// The features that this channel will operate with. If you reject the channel, a
 689                 /// well-behaved counterparty may automatically re-attempt the channel with a new set of
 690                 /// feature flags.
 691                 ///
 692                 /// Note that if [`ChannelTypeFeatures::supports_scid_privacy`] returns true on this type,
 693                 /// the resulting [`ChannelManager`] will not be readable by versions of LDK prior to
 694                 /// 0.0.106.
 695                 ///
 696                 /// Furthermore, note that if [`ChannelTypeFeatures::supports_zero_conf`] returns true on this type,
 697                 /// the resulting [`ChannelManager`] will not be readable by versions of LDK prior to
 698                 /// 0.0.107. Channels setting this type also need to get manually accepted via
 699                 /// [`crate::ln::channelmanager::ChannelManager::accept_inbound_channel_from_trusted_peer_0conf`],
 700                 /// or will be rejected otherwise.
 701                 ///
 702                 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 703                 channel_type: ChannelTypeFeatures,
 704         },
 705         /// Indicates that the HTLC was accepted, but could not be processed when or after attempting to
 706         /// forward it.
 707         ///
 708         /// Some scenarios where this event may be sent include:
 709         /// * Insufficient capacity in the outbound channel
 710         /// * While waiting to forward the HTLC, the channel it is meant to be forwarded through closes
 711         /// * When an unknown SCID is requested for forwarding a payment.
 712         /// * Claiming an amount for an MPP payment that exceeds the HTLC total
 713         /// * The HTLC has timed out
 714         ///
 715         /// This event, however, does not get generated if an HTLC fails to meet the forwarding
 716         /// requirements (i.e. insufficient fees paid, or a CLTV that is too soon).
 717         HTLCHandlingFailed {
 718                 /// The channel over which the HTLC was received.
 719                 prev_channel_id: [u8; 32],
 720                 /// Destination of the HTLC that failed to be processed.
 721                 failed_next_destination: HTLCDestination,
 722         },
 723         #[cfg(anchors)]
 724         /// Indicates that a transaction originating from LDK needs to have its fee bumped. This event
 725         /// requires confirmed external funds to be readily available to spend.
 726         ///
 727         /// LDK does not currently generate this event. It is limited to the scope of channels with
 728         /// anchor outputs, which will be introduced in a future release.
 729         BumpTransaction(BumpTransactionEvent),
 730 }
 731
 732 impl Writeable for Event {
 733         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 734                 match self {
 735                         &Event::FundingGenerationReady { .. } => {
 736                                 0u8.write(writer)?;
 737                                 // We never write out FundingGenerationReady events as, upon disconnection, peers
 738                                 // drop any channels which have not yet exchanged funding_signed.
 739                         },
 740                         &Event::PaymentReceived { ref payment_hash, ref amount_msat, ref purpose } => {
 741                                 1u8.write(writer)?;
 742                                 let mut payment_secret = None;
 743                                 let payment_preimage;
 744                                 match &purpose {
 745                                         PaymentPurpose::InvoicePayment { payment_preimage: preimage, payment_secret: secret } => {
 746                                                 payment_secret = Some(secret);
 747                                                 payment_preimage = *preimage;
 748                                         },
 749                                         PaymentPurpose::SpontaneousPayment(preimage) => {
 750                                                 payment_preimage = Some(*preimage);
 751                                         }
 752                                 }
 753                                 write_tlv_fields!(writer, {
 754                                         (0, payment_hash, required),
 755                                         (2, payment_secret, option),
 756                                         (4, amount_msat, required),
 757                                         (6, 0u64, required), // user_payment_id required for compatibility with 0.0.103 and earlier
 758                                         (8, payment_preimage, option),
 759                                 });
 760                         },
 761                         &Event::PaymentSent { ref payment_id, ref payment_preimage, ref payment_hash, ref fee_paid_msat } => {
 762                                 2u8.write(writer)?;
 763                                 write_tlv_fields!(writer, {
 764                                         (0, payment_preimage, required),
 765                                         (1, payment_hash, required),
 766                                         (3, payment_id, option),
 767                                         (5, fee_paid_msat, option),
 768                                 });
 769                         },
 770                         &Event::PaymentPathFailed {
 771                                 ref payment_id, ref payment_hash, ref payment_failed_permanently, ref network_update,
 772                                 ref all_paths_failed, ref path, ref short_channel_id, ref retry,
 773                                 #[cfg(test)]
 774                                 ref error_code,
 775                                 #[cfg(test)]
 776                                 ref error_data,
 777                         } => {
 778                                 3u8.write(writer)?;
 779                                 #[cfg(test)]
 780                                 error_code.write(writer)?;
 781                                 #[cfg(test)]
 782                                 error_data.write(writer)?;
 783                                 write_tlv_fields!(writer, {
 784                                         (0, payment_hash, required),
 785                                         (1, network_update, option),
 786                                         (2, payment_failed_permanently, required),
 787                                         (3, all_paths_failed, required),
 788                                         (5, *path, vec_type),
 789                                         (7, short_channel_id, option),
 790                                         (9, retry, option),
 791                                         (11, payment_id, option),
 792                                 });
 793                         },
 794                         &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
 795                                 4u8.write(writer)?;
 796                                 // Note that we now ignore these on the read end as we'll re-generate them in
 797                                 // ChannelManager, we write them here only for backwards compatibility.
 798                         },
 799                         &Event::SpendableOutputs { ref outputs } => {
 800                                 5u8.write(writer)?;
 801                                 write_tlv_fields!(writer, {
 802                                         (0, WithoutLength(outputs), required),
 803                                 });
 804                         },
 805                         &Event::PaymentForwarded { fee_earned_msat, prev_channel_id, claim_from_onchain_tx, next_channel_id } => {
 806                                 7u8.write(writer)?;
 807                                 write_tlv_fields!(writer, {
 808                                         (0, fee_earned_msat, option),
 809                                         (1, prev_channel_id, option),
 810                                         (2, claim_from_onchain_tx, required),
 811                                         (3, next_channel_id, option),
 812                                 });
 813                         },
 814                         &Event::ChannelClosed { ref channel_id, ref user_channel_id, ref reason } => {
 815                                 9u8.write(writer)?;
 816                                 write_tlv_fields!(writer, {
 817                                         (0, channel_id, required),
 818                                         (1, user_channel_id, required),
 819                                         (2, reason, required)
 820                                 });
 821                         },
 822                         &Event::DiscardFunding { ref channel_id, ref transaction } => {
 823                                 11u8.write(writer)?;
 824                                 write_tlv_fields!(writer, {
 825                                         (0, channel_id, required),
 826                                         (2, transaction, required)
 827                                 })
 828                         },
 829                         &Event::PaymentPathSuccessful { ref payment_id, ref payment_hash, ref path } => {
 830                                 13u8.write(writer)?;
 831                                 write_tlv_fields!(writer, {
 832                                         (0, payment_id, required),
 833                                         (2, payment_hash, option),
 834                                         (4, *path, vec_type)
 835                                 })
 836                         },
 837                         &Event::PaymentFailed { ref payment_id, ref payment_hash } => {
 838                                 15u8.write(writer)?;
 839                                 write_tlv_fields!(writer, {
 840                                         (0, payment_id, required),
 841                                         (2, payment_hash, required),
 842                                 })
 843                         },
 844                         &Event::OpenChannelRequest { .. } => {
 845                                 17u8.write(writer)?;
 846                                 // We never write the OpenChannelRequest events as, upon disconnection, peers
 847                                 // drop any channels which have not yet exchanged funding_signed.
 848                         },
 849                         &Event::PaymentClaimed { ref payment_hash, ref amount_msat, ref purpose } => {
 850                                 19u8.write(writer)?;
 851                                 write_tlv_fields!(writer, {
 852                                         (0, payment_hash, required),
 853                                         (2, purpose, required),
 854                                         (4, amount_msat, required),
 855                                 });
 856                         },
 857                         &Event::ProbeSuccessful { ref payment_id, ref payment_hash, ref path } => {
 858                                 21u8.write(writer)?;
 859                                 write_tlv_fields!(writer, {
 860                                         (0, payment_id, required),
 861                                         (2, payment_hash, required),
 862                                         (4, *path, vec_type)
 863                                 })
 864                         },
 865                         &Event::ProbeFailed { ref payment_id, ref payment_hash, ref path, ref short_channel_id } => {
 866                                 23u8.write(writer)?;
 867                                 write_tlv_fields!(writer, {
 868                                         (0, payment_id, required),
 869                                         (2, payment_hash, required),
 870                                         (4, *path, vec_type),
 871                                         (6, short_channel_id, option),
 872                                 })
 873                         },
 874                         &Event::HTLCHandlingFailed { ref prev_channel_id, ref failed_next_destination } => {
 875                                 25u8.write(writer)?;
 876                                 write_tlv_fields!(writer, {
 877                                         (0, prev_channel_id, required),
 878                                         (2, failed_next_destination, required),
 879                                 })
 880                         },
 881                         #[cfg(anchors)]
 882                         &Event::BumpTransaction(ref event)=> {
 883                                 27u8.write(writer)?;
 884                                 match event {
 885                                         // We never write the ChannelClose events as they'll be replayed upon restarting
 886                                         // anyway if the commitment transaction remains unconfirmed.
 887                                         BumpTransactionEvent::ChannelClose { .. } => {}
 888                                 }
 889                         }
 890                         &Event::ChannelReady { ref channel_id, ref user_channel_id, ref counterparty_node_id, ref channel_type } => {
 891                                 29u8.write(writer)?;
 892                                 write_tlv_fields!(writer, {
 893                                         (0, channel_id, required),
 894                                         (2, user_channel_id, required),
 895                                         (4, counterparty_node_id, required),
 896                                         (6, channel_type, required),
 897                                 });
 898                         },
 899                         // Note that, going forward, all new events must only write data inside of
 900                         // `write_tlv_fields`. Versions 0.0.101+ will ignore odd-numbered events that write
 901                         // data via `write_tlv_fields`.
 902                 }
 903                 Ok(())
 904         }
 905 }
 906 impl MaybeReadable for Event {
 907         fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
 908                 match Readable::read(reader)? {
 909                         // Note that we do not write a length-prefixed TLV for FundingGenerationReady events,
 910                         // unlike all other events, thus we return immediately here.
 911                         0u8 => Ok(None),
 912                         1u8 => {
 913                                 let f = || {
 914                                         let mut payment_hash = PaymentHash([0; 32]);
 915                                         let mut payment_preimage = None;
 916                                         let mut payment_secret = None;
 917                                         let mut amount_msat = 0;
 918                                         let mut _user_payment_id = None::<u64>; // For compatibility with 0.0.103 and earlier
 919                                         read_tlv_fields!(reader, {
 920                                                 (0, payment_hash, required),
 921                                                 (2, payment_secret, option),
 922                                                 (4, amount_msat, required),
 923                                                 (6, _user_payment_id, option),
 924                                                 (8, payment_preimage, option),
 925                                         });
 926                                         let purpose = match payment_secret {
 927                                                 Some(secret) => PaymentPurpose::InvoicePayment {
 928                                                         payment_preimage,
 929                                                         payment_secret: secret
 930                                                 },
 931                                                 None if payment_preimage.is_some() => PaymentPurpose::SpontaneousPayment(payment_preimage.unwrap()),
 932                                                 None => return Err(msgs::DecodeError::InvalidValue),
 933                                         };
 934                                         Ok(Some(Event::PaymentReceived {
 935                                                 payment_hash,
 936                                                 amount_msat,
 937                                                 purpose,
 938                                         }))
 939                                 };
 940                                 f()
 941                         },
 942                         2u8 => {
 943                                 let f = || {
 944                                         let mut payment_preimage = PaymentPreimage([0; 32]);
 945                                         let mut payment_hash = None;
 946                                         let mut payment_id = None;
 947                                         let mut fee_paid_msat = None;
 948                                         read_tlv_fields!(reader, {
 949                                                 (0, payment_preimage, required),
 950                                                 (1, payment_hash, option),
 951                                                 (3, payment_id, option),
 952                                                 (5, fee_paid_msat, option),
 953                                         });
 954                                         if payment_hash.is_none() {
 955                                                 payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()));
 956                                         }
 957                                         Ok(Some(Event::PaymentSent {
 958                                                 payment_id,
 959                                                 payment_preimage,
 960                                                 payment_hash: payment_hash.unwrap(),
 961                                                 fee_paid_msat,
 962                                         }))
 963                                 };
 964                                 f()
 965                         },
 966                         3u8 => {
 967                                 let f = || {
 968                                         #[cfg(test)]
 969                                         let error_code = Readable::read(reader)?;
 970                                         #[cfg(test)]
 971                                         let error_data = Readable::read(reader)?;
 972                                         let mut payment_hash = PaymentHash([0; 32]);
 973                                         let mut payment_failed_permanently = false;
 974                                         let mut network_update = None;
 975                                         let mut all_paths_failed = Some(true);
 976                                         let mut path: Option<Vec<RouteHop>> = Some(vec![]);
 977                                         let mut short_channel_id = None;
 978                                         let mut retry = None;
 979                                         let mut payment_id = None;
 980                                         read_tlv_fields!(reader, {
 981                                                 (0, payment_hash, required),
 982                                                 (1, network_update, ignorable),
 983                                                 (2, payment_failed_permanently, required),
 984                                                 (3, all_paths_failed, option),
 985                                                 (5, path, vec_type),
 986                                                 (7, short_channel_id, option),
 987                                                 (9, retry, option),
 988                                                 (11, payment_id, option),
 989                                         });
 990                                         Ok(Some(Event::PaymentPathFailed {
 991                                                 payment_id,
 992                                                 payment_hash,
 993                                                 payment_failed_permanently,
 994                                                 network_update,
 995                                                 all_paths_failed: all_paths_failed.unwrap(),
 996                                                 path: path.unwrap(),
 997                                                 short_channel_id,
 998                                                 retry,
 999                                                 #[cfg(test)]
1000                                                 error_code,
1001                                                 #[cfg(test)]
1002                                                 error_data,
1003                                         }))
1004                                 };
1005                                 f()
1006                         },
1007                         4u8 => Ok(None),
1008                         5u8 => {
1009                                 let f = || {
1010                                         let mut outputs = WithoutLength(Vec::new());
1011                                         read_tlv_fields!(reader, {
1012                                                 (0, outputs, required),
1013                                         });
1014                                         Ok(Some(Event::SpendableOutputs { outputs: outputs.0 }))
1015                                 };
1016                                 f()
1017                         },
1018                         7u8 => {
1019                                 let f = || {
1020                                         let mut fee_earned_msat = None;
1021                                         let mut prev_channel_id = None;
1022                                         let mut claim_from_onchain_tx = false;
1023                                         let mut next_channel_id = None;
1024                                         read_tlv_fields!(reader, {
1025                                                 (0, fee_earned_msat, option),
1026                                                 (1, prev_channel_id, option),
1027                                                 (2, claim_from_onchain_tx, required),
1028                                                 (3, next_channel_id, option),
1029                                         });
1030                                         Ok(Some(Event::PaymentForwarded { fee_earned_msat, prev_channel_id, claim_from_onchain_tx, next_channel_id }))
1031                                 };
1032                                 f()
1033                         },
1034                         9u8 => {
1035                                 let f = || {
1036                                         let mut channel_id = [0; 32];
1037                                         let mut reason = None;
1038                                         let mut user_channel_id_opt = None;
1039                                         read_tlv_fields!(reader, {
1040                                                 (0, channel_id, required),
1041                                                 (1, user_channel_id_opt, option),
1042                                                 (2, reason, ignorable),
1043                                         });
1044                                         if reason.is_none() { return Ok(None); }
1045                                         let user_channel_id = if let Some(id) = user_channel_id_opt { id } else { 0 };
1046                                         Ok(Some(Event::ChannelClosed { channel_id, user_channel_id, reason: reason.unwrap() }))
1047                                 };
1048                                 f()
1049                         },
1050                         11u8 => {
1051                                 let f = || {
1052                                         let mut channel_id = [0; 32];
1053                                         let mut transaction = Transaction{ version: 2, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
1054                                         read_tlv_fields!(reader, {
1055                                                 (0, channel_id, required),
1056                                                 (2, transaction, required),
1057                                         });
1058                                         Ok(Some(Event::DiscardFunding { channel_id, transaction } ))
1059                                 };
1060                                 f()
1061                         },
1062                         13u8 => {
1063                                 let f = || {
1064                                         let mut payment_id = PaymentId([0; 32]);
1065                                         let mut payment_hash = None;
1066                                         let mut path: Option<Vec<RouteHop>> = Some(vec![]);
1067                                         read_tlv_fields!(reader, {
1068                                                 (0, payment_id, required),
1069                                                 (2, payment_hash, option),
1070                                                 (4, path, vec_type),
1071                                         });
1072                                         Ok(Some(Event::PaymentPathSuccessful {
1073                                                 payment_id,
1074                                                 payment_hash,
1075                                                 path: path.unwrap(),
1076                                         }))
1077                                 };
1078                                 f()
1079                         },
1080                         15u8 => {
1081                                 let f = || {
1082                                         let mut payment_hash = PaymentHash([0; 32]);
1083                                         let mut payment_id = PaymentId([0; 32]);
1084                                         read_tlv_fields!(reader, {
1085                                                 (0, payment_id, required),
1086                                                 (2, payment_hash, required),
1087                                         });
1088                                         Ok(Some(Event::PaymentFailed {
1089                                                 payment_id,
1090                                                 payment_hash,
1091                                         }))
1092                                 };
1093                                 f()
1094                         },
1095                         17u8 => {
1096                                 // Value 17 is used for `Event::OpenChannelRequest`.
1097                                 Ok(None)
1098                         },
1099                         19u8 => {
1100                                 let f = || {
1101                                         let mut payment_hash = PaymentHash([0; 32]);
1102                                         let mut purpose = None;
1103                                         let mut amount_msat = 0;
1104                                         read_tlv_fields!(reader, {
1105                                                 (0, payment_hash, required),
1106                                                 (2, purpose, ignorable),
1107                                                 (4, amount_msat, required),
1108                                         });
1109                                         if purpose.is_none() { return Ok(None); }
1110                                         Ok(Some(Event::PaymentClaimed {
1111                                                 payment_hash,
1112                                                 purpose: purpose.unwrap(),
1113                                                 amount_msat,
1114                                         }))
1115                                 };
1116                                 f()
1117                         },
1118                         21u8 => {
1119                                 let f = || {
1120                                         let mut payment_id = PaymentId([0; 32]);
1121                                         let mut payment_hash = PaymentHash([0; 32]);
1122                                         let mut path: Option<Vec<RouteHop>> = Some(vec![]);
1123                                         read_tlv_fields!(reader, {
1124                                                 (0, payment_id, required),
1125                                                 (2, payment_hash, required),
1126                                                 (4, path, vec_type),
1127                                         });
1128                                         Ok(Some(Event::ProbeSuccessful {
1129                                                 payment_id,
1130                                                 payment_hash,
1131                                                 path: path.unwrap(),
1132                                         }))
1133                                 };
1134                                 f()
1135                         },
1136                         23u8 => {
1137                                 let f = || {
1138                                         let mut payment_id = PaymentId([0; 32]);
1139                                         let mut payment_hash = PaymentHash([0; 32]);
1140                                         let mut path: Option<Vec<RouteHop>> = Some(vec![]);
1141                                         let mut short_channel_id = None;
1142                                         read_tlv_fields!(reader, {
1143                                                 (0, payment_id, required),
1144                                                 (2, payment_hash, required),
1145                                                 (4, path, vec_type),
1146                                                 (6, short_channel_id, option),
1147                                         });
1148                                         Ok(Some(Event::ProbeFailed {
1149                                                 payment_id,
1150                                                 payment_hash,
1151                                                 path: path.unwrap(),
1152                                                 short_channel_id,
1153                                         }))
1154                                 };
1155                                 f()
1156                         },
1157                         25u8 => {
1158                                 let f = || {
1159                                         let mut prev_channel_id = [0; 32];
1160                                         let mut failed_next_destination_opt = None;
1161                                         read_tlv_fields!(reader, {
1162                                                 (0, prev_channel_id, required),
1163                                                 (2, failed_next_destination_opt, ignorable),
1164                                         });
1165                                         if let Some(failed_next_destination) = failed_next_destination_opt {
1166                                                 Ok(Some(Event::HTLCHandlingFailed {
1167                                                         prev_channel_id,
1168                                                         failed_next_destination,
1169                                                 }))
1170                                         } else {
1171                                                 // If we fail to read a `failed_next_destination` assume it's because
1172                                                 // `MaybeReadable::read` returned `Ok(None)`, though it's also possible we
1173                                                 // were simply missing the field.
1174                                                 Ok(None)
1175                                         }
1176                                 };
1177                                 f()
1178                         },
1179                         27u8 => Ok(None),
1180                         29u8 => {
1181                                 let f = || {
1182                                         let mut channel_id = [0; 32];
1183                                         let mut user_channel_id: u64 = 0;
1184                                         let mut counterparty_node_id = OptionDeserWrapper(None);
1185                                         let mut channel_type = OptionDeserWrapper(None);
1186                                         read_tlv_fields!(reader, {
1187                                                 (0, channel_id, required),
1188                                                 (2, user_channel_id, required),
1189                                                 (4, counterparty_node_id, required),
1190                                                 (6, channel_type, required),
1191                                         });
1192
1193                                         Ok(Some(Event::ChannelReady {
1194                                                 channel_id,
1195                                                 user_channel_id,
1196                                                 counterparty_node_id: counterparty_node_id.0.unwrap(),
1197                                                 channel_type: channel_type.0.unwrap()
1198                                         }))
1199                                 };
1200                                 f()
1201                         },
1202                         // Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue.
1203                         // Version 0.0.100 failed to properly ignore odd types, possibly resulting in corrupt
1204                         // reads.
1205                         x if x % 2 == 1 => {
1206                                 // If the event is of unknown type, assume it was written with `write_tlv_fields`,
1207                                 // which prefixes the whole thing with a length BigSize. Because the event is
1208                                 // odd-type unknown, we should treat it as `Ok(None)` even if it has some TLV
1209                                 // fields that are even. Thus, we avoid using `read_tlv_fields` and simply read
1210                                 // exactly the number of bytes specified, ignoring them entirely.
1211                                 let tlv_len: BigSize = Readable::read(reader)?;
1212                                 FixedLengthReader::new(reader, tlv_len.0)
1213                                         .eat_remaining().map_err(|_| msgs::DecodeError::ShortRead)?;
1214                                 Ok(None)
1215                         },
1216                         _ => Err(msgs::DecodeError::InvalidValue)
1217                 }
1218         }
1219 }
1220
1221 /// An event generated by ChannelManager which indicates a message should be sent to a peer (or
1222 /// broadcast to most peers).
1223 /// These events are handled by PeerManager::process_events if you are using a PeerManager.
1224 #[derive(Clone, Debug)]
1225 pub enum MessageSendEvent {
1226         /// Used to indicate that we've accepted a channel open and should send the accept_channel
1227         /// message provided to the given peer.
1228         SendAcceptChannel {
1229                 /// The node_id of the node which should receive this message
1230                 node_id: PublicKey,
1231                 /// The message which should be sent.
1232                 msg: msgs::AcceptChannel,
1233         },
1234         /// Used to indicate that we've initiated a channel open and should send the open_channel
1235         /// message provided to the given peer.
1236         SendOpenChannel {
1237                 /// The node_id of the node which should receive this message
1238                 node_id: PublicKey,
1239                 /// The message which should be sent.
1240                 msg: msgs::OpenChannel,
1241         },
1242         /// Used to indicate that a funding_created message should be sent to the peer with the given node_id.
1243         SendFundingCreated {
1244                 /// The node_id of the node which should receive this message
1245                 node_id: PublicKey,
1246                 /// The message which should be sent.
1247                 msg: msgs::FundingCreated,
1248         },
1249         /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id.
1250         SendFundingSigned {
1251                 /// The node_id of the node which should receive this message
1252                 node_id: PublicKey,
1253                 /// The message which should be sent.
1254                 msg: msgs::FundingSigned,
1255         },
1256         /// Used to indicate that a channel_ready message should be sent to the peer with the given node_id.
1257         SendChannelReady {
1258                 /// The node_id of the node which should receive these message(s)
1259                 node_id: PublicKey,
1260                 /// The channel_ready message which should be sent.
1261                 msg: msgs::ChannelReady,
1262         },
1263         /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
1264         SendAnnouncementSignatures {
1265                 /// The node_id of the node which should receive these message(s)
1266                 node_id: PublicKey,
1267                 /// The announcement_signatures message which should be sent.
1268                 msg: msgs::AnnouncementSignatures,
1269         },
1270         /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed
1271         /// message should be sent to the peer with the given node_id.
1272         UpdateHTLCs {
1273                 /// The node_id of the node which should receive these message(s)
1274                 node_id: PublicKey,
1275                 /// The update messages which should be sent. ALL messages in the struct should be sent!
1276                 updates: msgs::CommitmentUpdate,
1277         },
1278         /// Used to indicate that a revoke_and_ack message should be sent to the peer with the given node_id.
1279         SendRevokeAndACK {
1280                 /// The node_id of the node which should receive this message
1281                 node_id: PublicKey,
1282                 /// The message which should be sent.
1283                 msg: msgs::RevokeAndACK,
1284         },
1285         /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id.
1286         SendClosingSigned {
1287                 /// The node_id of the node which should receive this message
1288                 node_id: PublicKey,
1289                 /// The message which should be sent.
1290                 msg: msgs::ClosingSigned,
1291         },
1292         /// Used to indicate that a shutdown message should be sent to the peer with the given node_id.
1293         SendShutdown {
1294                 /// The node_id of the node which should receive this message
1295                 node_id: PublicKey,
1296                 /// The message which should be sent.
1297                 msg: msgs::Shutdown,
1298         },
1299         /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id.
1300         SendChannelReestablish {
1301                 /// The node_id of the node which should receive this message
1302                 node_id: PublicKey,
1303                 /// The message which should be sent.
1304                 msg: msgs::ChannelReestablish,
1305         },
1306         /// Used to send a channel_announcement and channel_update to a specific peer, likely on
1307         /// initial connection to ensure our peers know about our channels.
1308         SendChannelAnnouncement {
1309                 /// The node_id of the node which should receive this message
1310                 node_id: PublicKey,
1311                 /// The channel_announcement which should be sent.
1312                 msg: msgs::ChannelAnnouncement,
1313                 /// The followup channel_update which should be sent.
1314                 update_msg: msgs::ChannelUpdate,
1315         },
1316         /// Used to indicate that a channel_announcement and channel_update should be broadcast to all
1317         /// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
1318         ///
1319         /// Note that after doing so, you very likely (unless you did so very recently) want to
1320         /// broadcast a node_announcement (e.g. via [`PeerManager::broadcast_node_announcement`]). This
1321         /// ensures that any nodes which see our channel_announcement also have a relevant
1322         /// node_announcement, including relevant feature flags which may be important for routing
1323         /// through or to us.
1324         ///
1325         /// [`PeerManager::broadcast_node_announcement`]: crate::ln::peer_handler::PeerManager::broadcast_node_announcement
1326         BroadcastChannelAnnouncement {
1327                 /// The channel_announcement which should be sent.
1328                 msg: msgs::ChannelAnnouncement,
1329                 /// The followup channel_update which should be sent.
1330                 update_msg: msgs::ChannelUpdate,
1331         },
1332         /// Used to indicate that a channel_update should be broadcast to all peers.
1333         BroadcastChannelUpdate {
1334                 /// The channel_update which should be sent.
1335                 msg: msgs::ChannelUpdate,
1336         },
1337         /// Used to indicate that a channel_update should be sent to a single peer.
1338         /// In contrast to [`Self::BroadcastChannelUpdate`], this is used when the channel is a
1339         /// private channel and we shouldn't be informing all of our peers of channel parameters.
1340         SendChannelUpdate {
1341                 /// The node_id of the node which should receive this message
1342                 node_id: PublicKey,
1343                 /// The channel_update which should be sent.
1344                 msg: msgs::ChannelUpdate,
1345         },
1346         /// Broadcast an error downstream to be handled
1347         HandleError {
1348                 /// The node_id of the node which should receive this message
1349                 node_id: PublicKey,
1350                 /// The action which should be taken.
1351                 action: msgs::ErrorAction
1352         },
1353         /// Query a peer for channels with funding transaction UTXOs in a block range.
1354         SendChannelRangeQuery {
1355                 /// The node_id of this message recipient
1356                 node_id: PublicKey,
1357                 /// The query_channel_range which should be sent.
1358                 msg: msgs::QueryChannelRange,
1359         },
1360         /// Request routing gossip messages from a peer for a list of channels identified by
1361         /// their short_channel_ids.
1362         SendShortIdsQuery {
1363                 /// The node_id of this message recipient
1364                 node_id: PublicKey,
1365                 /// The query_short_channel_ids which should be sent.
1366                 msg: msgs::QueryShortChannelIds,
1367         },
1368         /// Sends a reply to a channel range query. This may be one of several SendReplyChannelRange events
1369         /// emitted during processing of the query.
1370         SendReplyChannelRange {
1371                 /// The node_id of this message recipient
1372                 node_id: PublicKey,
1373                 /// The reply_channel_range which should be sent.
1374                 msg: msgs::ReplyChannelRange,
1375         },
1376         /// Sends a timestamp filter for inbound gossip. This should be sent on each new connection to
1377         /// enable receiving gossip messages from the peer.
1378         SendGossipTimestampFilter {
1379                 /// The node_id of this message recipient
1380                 node_id: PublicKey,
1381                 /// The gossip_timestamp_filter which should be sent.
1382                 msg: msgs::GossipTimestampFilter,
1383         },
1384 }
1385
1386 /// A trait indicating an object may generate message send events
1387 pub trait MessageSendEventsProvider {
1388         /// Gets the list of pending events which were generated by previous actions, clearing the list
1389         /// in the process.
1390         fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
1391 }
1392
1393 /// A trait indicating an object may generate onion messages to send
1394 pub trait OnionMessageProvider {
1395         /// Gets the next pending onion message for the peer with the given node id.
1396         fn next_onion_message_for_peer(&self, peer_node_id: PublicKey) -> Option<msgs::OnionMessage>;
1397 }
1398
1399 /// A trait indicating an object may generate events.
1400 ///
1401 /// Events are processed by passing an [`EventHandler`] to [`process_pending_events`].
1402 ///
1403 /// # Requirements
1404 ///
1405 /// When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
1406 /// event since the last invocation.
1407 ///
1408 /// In order to ensure no [`Event`]s are lost, implementors of this trait will persist [`Event`]s
1409 /// and replay any unhandled events on startup. An [`Event`] is considered handled when
1410 /// [`process_pending_events`] returns, thus handlers MUST fully handle [`Event`]s and persist any
1411 /// relevant changes to disk *before* returning.
1412 ///
1413 /// Further, because an application may crash between an [`Event`] being handled and the
1414 /// implementor of this trait being re-serialized, [`Event`] handling must be idempotent - in
1415 /// effect, [`Event`]s may be replayed.
1416 ///
1417 /// Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
1418 /// consult the provider's documentation on the implication of processing events and how a handler
1419 /// may safely use the provider (e.g., see [`ChannelManager::process_pending_events`] and
1420 /// [`ChainMonitor::process_pending_events`]).
1421 ///
1422 /// (C-not implementable) As there is likely no reason for a user to implement this trait on their
1423 /// own type(s).
1424 ///
1425 /// [`process_pending_events`]: Self::process_pending_events
1426 /// [`handle_event`]: EventHandler::handle_event
1427 /// [`ChannelManager::process_pending_events`]: crate::ln::channelmanager::ChannelManager#method.process_pending_events
1428 /// [`ChainMonitor::process_pending_events`]: crate::chain::chainmonitor::ChainMonitor#method.process_pending_events
1429 pub trait EventsProvider {
1430         /// Processes any events generated since the last call using the given event handler.
1431         ///
1432         /// See the trait-level documentation for requirements.
1433         fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler;
1434 }
1435
1436 /// A trait implemented for objects handling events from [`EventsProvider`].
1437 pub trait EventHandler {
1438         /// Handles the given [`Event`].
1439         ///
1440         /// See [`EventsProvider`] for details that must be considered when implementing this method.
1441         fn handle_event(&self, event: &Event);
1442 }
1443
1444 impl<F> EventHandler for F where F: Fn(&Event) {
1445         fn handle_event(&self, event: &Event) {
1446                 self(event)
1447         }
1448 }
1449
1450 impl<T: EventHandler> EventHandler for Arc<T> {
1451         fn handle_event(&self, event: &Event) {
1452                 self.deref().handle_event(event)
1453         }
1454 }