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