_ Git - rust-lightning/blob - lightning/src/events/mod.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 #[cfg(anchors)]
  18 pub mod bump_transaction;
  19
  20 #[cfg(anchors)]
  21 pub use bump_transaction::BumpTransactionEvent;
  22
  23 use crate::chain::keysinterface::SpendableOutputDescriptor;
  24 use crate::ln::channelmanager::{InterceptId, PaymentId};
  25 use crate::ln::channel::FUNDING_CONF_DEADLINE_BLOCKS;
  26 use crate::ln::features::ChannelTypeFeatures;
  27 use crate::ln::msgs;
  28 use crate::ln::{PaymentPreimage, PaymentHash, PaymentSecret};
  29 use crate::routing::gossip::NetworkUpdate;
  30 use crate::util::errors::APIError;
  31 use crate::util::ser::{BigSize, FixedLengthReader, Writeable, Writer, MaybeReadable, Readable, RequiredWrapper, UpgradableRequired, WithoutLength};
  32 use crate::util::string::UntrustedString;
  33 use crate::routing::router::{RouteHop, RouteParameters};
  34
  35 use bitcoin::{PackedLockTime, Transaction, OutPoint};
  36 #[cfg(anchors)]
  37 use bitcoin::{Txid, TxIn, TxOut, Witness};
  38 use bitcoin::blockdata::script::Script;
  39 use bitcoin::hashes::Hash;
  40 use bitcoin::hashes::sha256::Hash as Sha256;
  41 use bitcoin::secp256k1::PublicKey;
  42 use crate::io;
  43 use crate::prelude::*;
  44 use core::time::Duration;
  45 use core::ops::Deref;
  46 use crate::sync::Arc;
  47
  48 /// Some information provided on receipt of payment depends on whether the payment received is a
  49 /// spontaneous payment or a "conventional" lightning payment that's paying an invoice.
  50 #[derive(Clone, Debug, PartialEq, Eq)]
  51 pub enum PaymentPurpose {
  52         /// Information for receiving a payment that we generated an invoice for.
  53         InvoicePayment {
  54                 /// The preimage to the payment_hash, if the payment hash (and secret) were fetched via
  55                 /// [`ChannelManager::create_inbound_payment`]. If provided, this can be handed directly to
  56                 /// [`ChannelManager::claim_funds`].
  57                 ///
  58                 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
  59                 /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
  60                 payment_preimage: Option<PaymentPreimage>,
  61                 /// The "payment secret". This authenticates the sender to the recipient, preventing a
  62                 /// number of deanonymization attacks during the routing process.
  63                 /// It is provided here for your reference, however its accuracy is enforced directly by
  64                 /// [`ChannelManager`] using the values you previously provided to
  65                 /// [`ChannelManager::create_inbound_payment`] or
  66                 /// [`ChannelManager::create_inbound_payment_for_hash`].
  67                 ///
  68                 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
  69                 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
  70                 /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
  71                 payment_secret: PaymentSecret,
  72         },
  73         /// Because this is a spontaneous payment, the payer generated their own preimage rather than us
  74         /// (the payee) providing a preimage.
  75         SpontaneousPayment(PaymentPreimage),
  76 }
  77
  78 impl_writeable_tlv_based_enum!(PaymentPurpose,
  79         (0, InvoicePayment) => {
  80                 (0, payment_preimage, option),
  81                 (2, payment_secret, required),
  82         };
  83         (2, SpontaneousPayment)
  84 );
  85
  86 /// When the payment path failure took place and extra details about it. [`PathFailure::OnPath`] may
  87 /// contain a [`NetworkUpdate`] that needs to be applied to the [`NetworkGraph`].
  88 ///
  89 /// [`NetworkUpdate`]: crate::routing::gossip::NetworkUpdate
  90 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
  91 #[derive(Clone, Debug, Eq, PartialEq)]
  92 pub enum PathFailure {
  93         /// We failed to initially send the payment and no HTLC was committed to. Contains the relevant
  94         /// error.
  95         InitialSend {
  96                 /// The error surfaced from initial send.
  97                 err: APIError,
  98         },
  99         /// A hop on the path failed to forward our payment.
 100         OnPath {
 101                 /// If present, this [`NetworkUpdate`] should be applied to the [`NetworkGraph`] so that routing
 102                 /// decisions can take into account the update.
 103                 ///
 104                 /// [`NetworkUpdate`]: crate::routing::gossip::NetworkUpdate
 105                 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
 106                 network_update: Option<NetworkUpdate>,
 107         },
 108 }
 109
 110 impl_writeable_tlv_based_enum_upgradable!(PathFailure,
 111         (0, OnPath) => {
 112                 (0, network_update, upgradable_option),
 113         },
 114         (2, InitialSend) => {
 115                 (0, err, upgradable_required),
 116         },
 117 );
 118
 119 #[derive(Clone, Debug, PartialEq, Eq)]
 120 /// The reason the channel was closed. See individual variants more details.
 121 pub enum ClosureReason {
 122         /// Closure generated from receiving a peer error message.
 123         ///
 124         /// Our counterparty may have broadcasted their latest commitment state, and we have
 125         /// as well.
 126         CounterpartyForceClosed {
 127                 /// The error which the peer sent us.
 128                 ///
 129                 /// Be careful about printing the peer_msg, a well-crafted message could exploit
 130                 /// a security vulnerability in the terminal emulator or the logging subsystem.
 131                 /// To be safe, use `Display` on `UntrustedString`
 132                 ///
 133                 /// [`UntrustedString`]: crate::util::string::UntrustedString
 134                 peer_msg: UntrustedString,
 135         },
 136         /// Closure generated from [`ChannelManager::force_close_channel`], called by the user.
 137         ///
 138         /// [`ChannelManager::force_close_channel`]: crate::ln::channelmanager::ChannelManager::force_close_channel.
 139         HolderForceClosed,
 140         /// The channel was closed after negotiating a cooperative close and we've now broadcasted
 141         /// the cooperative close transaction. Note the shutdown may have been initiated by us.
 142         //TODO: split between CounterpartyInitiated/LocallyInitiated
 143         CooperativeClosure,
 144         /// A commitment transaction was confirmed on chain, closing the channel. Most likely this
 145         /// commitment transaction came from our counterparty, but it may also have come from
 146         /// a copy of our own `ChannelMonitor`.
 147         CommitmentTxConfirmed,
 148         /// The funding transaction failed to confirm in a timely manner on an inbound channel.
 149         FundingTimedOut,
 150         /// Closure generated from processing an event, likely a HTLC forward/relay/reception.
 151         ProcessingError {
 152                 /// A developer-readable error message which we generated.
 153                 err: String,
 154         },
 155         /// The peer disconnected prior to funding completing. In this case the spec mandates that we
 156         /// forget the channel entirely - we can attempt again if the peer reconnects.
 157         ///
 158         /// This includes cases where we restarted prior to funding completion, including prior to the
 159         /// initial [`ChannelMonitor`] persistence completing.
 160         ///
 161         /// In LDK versions prior to 0.0.107 this could also occur if we were unable to connect to the
 162         /// peer because of mutual incompatibility between us and our channel counterparty.
 163         ///
 164         /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
 165         DisconnectedPeer,
 166         /// Closure generated from `ChannelManager::read` if the [`ChannelMonitor`] is newer than
 167         /// the [`ChannelManager`] deserialized.
 168         ///
 169         /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
 170         /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 171         OutdatedChannelManager
 172 }
 173
 174 impl core::fmt::Display for ClosureReason {
 175         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
 176                 f.write_str("Channel closed because ")?;
 177                 match self {
 178                         ClosureReason::CounterpartyForceClosed { peer_msg } => {
 179                                 f.write_fmt(format_args!("counterparty force-closed with message: {}", peer_msg))
 180                         },
 181                         ClosureReason::HolderForceClosed => f.write_str("user manually force-closed the channel"),
 182                         ClosureReason::CooperativeClosure => f.write_str("the channel was cooperatively closed"),
 183                         ClosureReason::CommitmentTxConfirmed => f.write_str("commitment or closing transaction was confirmed on chain."),
 184                         ClosureReason::FundingTimedOut => write!(f, "funding transaction failed to confirm within {} blocks", FUNDING_CONF_DEADLINE_BLOCKS),
 185                         ClosureReason::ProcessingError { err } => {
 186                                 f.write_str("of an exception: ")?;
 187                                 f.write_str(&err)
 188                         },
 189                         ClosureReason::DisconnectedPeer => f.write_str("the peer disconnected prior to the channel being funded"),
 190                         ClosureReason::OutdatedChannelManager => f.write_str("the ChannelManager read from disk was stale compared to ChannelMonitor(s)"),
 191                 }
 192         }
 193 }
 194
 195 impl_writeable_tlv_based_enum_upgradable!(ClosureReason,
 196         (0, CounterpartyForceClosed) => { (1, peer_msg, required) },
 197         (1, FundingTimedOut) => {},
 198         (2, HolderForceClosed) => {},
 199         (6, CommitmentTxConfirmed) => {},
 200         (4, CooperativeClosure) => {},
 201         (8, ProcessingError) => { (1, err, required) },
 202         (10, DisconnectedPeer) => {},
 203         (12, OutdatedChannelManager) => {},
 204 );
 205
 206 /// Intended destination of a failed HTLC as indicated in [`Event::HTLCHandlingFailed`].
 207 #[derive(Clone, Debug, PartialEq, Eq)]
 208 pub enum HTLCDestination {
 209         /// We tried forwarding to a channel but failed to do so. An example of such an instance is when
 210         /// there is insufficient capacity in our outbound channel.
 211         NextHopChannel {
 212                 /// The `node_id` of the next node. For backwards compatibility, this field is
 213                 /// marked as optional, versions prior to 0.0.110 may not always be able to provide
 214                 /// counterparty node information.
 215                 node_id: Option<PublicKey>,
 216                 /// The outgoing `channel_id` between us and the next node.
 217                 channel_id: [u8; 32],
 218         },
 219         /// Scenario where we are unsure of the next node to forward the HTLC to.
 220         UnknownNextHop {
 221                 /// Short channel id we are requesting to forward an HTLC to.
 222                 requested_forward_scid: u64,
 223         },
 224         /// We couldn't forward to the outgoing scid. An example would be attempting to send a duplicate
 225         /// intercept HTLC.
 226         InvalidForward {
 227                 /// Short channel id we are requesting to forward an HTLC to.
 228                 requested_forward_scid: u64
 229         },
 230         /// Failure scenario where an HTLC may have been forwarded to be intended for us,
 231         /// but is invalid for some reason, so we reject it.
 232         ///
 233         /// Some of the reasons may include:
 234         /// * HTLC Timeouts
 235         /// * Expected MPP amount has already been reached
 236         /// * Claimable amount does not match expected amount
 237         FailedPayment {
 238                 /// The payment hash of the payment we attempted to process.
 239                 payment_hash: PaymentHash
 240         },
 241 }
 242
 243 impl_writeable_tlv_based_enum_upgradable!(HTLCDestination,
 244         (0, NextHopChannel) => {
 245                 (0, node_id, required),
 246                 (2, channel_id, required),
 247         },
 248         (1, InvalidForward) => {
 249                 (0, requested_forward_scid, required),
 250         },
 251         (2, UnknownNextHop) => {
 252                 (0, requested_forward_scid, required),
 253         },
 254         (4, FailedPayment) => {
 255                 (0, payment_hash, required),
 256         },
 257 );
 258
 259 /// Will be used in [`Event::HTLCIntercepted`] to identify the next hop in the HTLC's path.
 260 /// Currently only used in serialization for the sake of maintaining compatibility. More variants
 261 /// will be added for general-purpose HTLC forward intercepts as well as trampoline forward
 262 /// intercepts in upcoming work.
 263 enum InterceptNextHop {
 264         FakeScid {
 265                 requested_next_hop_scid: u64,
 266         },
 267 }
 268
 269 impl_writeable_tlv_based_enum!(InterceptNextHop,
 270         (0, FakeScid) => {
 271                 (0, requested_next_hop_scid, required),
 272         };
 273 );
 274
 275 /// An Event which you should probably take some action in response to.
 276 ///
 277 /// Note that while Writeable and Readable are implemented for Event, you probably shouldn't use
 278 /// them directly as they don't round-trip exactly (for example FundingGenerationReady is never
 279 /// written as it makes no sense to respond to it after reconnecting to peers).
 280 #[derive(Clone, Debug, PartialEq, Eq)]
 281 pub enum Event {
 282         /// Used to indicate that the client should generate a funding transaction with the given
 283         /// parameters and then call [`ChannelManager::funding_transaction_generated`].
 284         /// Generated in [`ChannelManager`] message handling.
 285         /// Note that *all inputs* in the funding transaction must spend SegWit outputs or your
 286         /// counterparty can steal your funds!
 287         ///
 288         /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 289         /// [`ChannelManager::funding_transaction_generated`]: crate::ln::channelmanager::ChannelManager::funding_transaction_generated
 290         FundingGenerationReady {
 291                 /// The random channel_id we picked which you'll need to pass into
 292                 /// [`ChannelManager::funding_transaction_generated`].
 293                 ///
 294                 /// [`ChannelManager::funding_transaction_generated`]: crate::ln::channelmanager::ChannelManager::funding_transaction_generated
 295                 temporary_channel_id: [u8; 32],
 296                 /// The counterparty's node_id, which you'll need to pass back into
 297                 /// [`ChannelManager::funding_transaction_generated`].
 298                 ///
 299                 /// [`ChannelManager::funding_transaction_generated`]: crate::ln::channelmanager::ChannelManager::funding_transaction_generated
 300                 counterparty_node_id: PublicKey,
 301                 /// The value, in satoshis, that the output should have.
 302                 channel_value_satoshis: u64,
 303                 /// The script which should be used in the transaction output.
 304                 output_script: Script,
 305                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`], or a
 306                 /// random value for an inbound channel. This may be zero for objects serialized with LDK
 307                 /// versions prior to 0.0.113.
 308                 ///
 309                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
 310                 user_channel_id: u128,
 311         },
 312         /// Indicates that we've been offered a payment and it needs to be claimed via calling
 313         /// [`ChannelManager::claim_funds`] with the preimage given in [`PaymentPurpose`].
 314         ///
 315         /// Note that if the preimage is not known, you should call
 316         /// [`ChannelManager::fail_htlc_backwards`] or [`ChannelManager::fail_htlc_backwards_with_reason`]
 317         /// to free up resources for this HTLC and avoid network congestion.
 318         /// If you fail to call either [`ChannelManager::claim_funds`], [`ChannelManager::fail_htlc_backwards`],
 319         /// or [`ChannelManager::fail_htlc_backwards_with_reason`] within the HTLC's timeout, the HTLC will be
 320         /// automatically failed.
 321         ///
 322         /// # Note
 323         /// LDK will not stop an inbound payment from being paid multiple times, so multiple
 324         /// `PaymentClaimable` events may be generated for the same payment.
 325         ///
 326         /// # Note
 327         /// This event used to be called `PaymentReceived` in LDK versions 0.0.112 and earlier.
 328         ///
 329         /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
 330         /// [`ChannelManager::fail_htlc_backwards`]: crate::ln::channelmanager::ChannelManager::fail_htlc_backwards
 331         /// [`ChannelManager::fail_htlc_backwards_with_reason`]: crate::ln::channelmanager::ChannelManager::fail_htlc_backwards_with_reason
 332         PaymentClaimable {
 333                 /// The node that will receive the payment after it has been claimed.
 334                 /// This is useful to identify payments received via [phantom nodes].
 335                 /// This field will always be filled in when the event was generated by LDK versions
 336                 /// 0.0.113 and above.
 337                 ///
 338                 /// [phantom nodes]: crate::chain::keysinterface::PhantomKeysManager
 339                 receiver_node_id: Option<PublicKey>,
 340                 /// The hash for which the preimage should be handed to the ChannelManager. Note that LDK will
 341                 /// not stop you from registering duplicate payment hashes for inbound payments.
 342                 payment_hash: PaymentHash,
 343                 /// The value, in thousandths of a satoshi, that this payment is for.
 344                 amount_msat: u64,
 345                 /// Information for claiming this received payment, based on whether the purpose of the
 346                 /// payment is to pay an invoice or to send a spontaneous payment.
 347                 purpose: PaymentPurpose,
 348                 /// The `channel_id` indicating over which channel we received the payment.
 349                 via_channel_id: Option<[u8; 32]>,
 350                 /// The `user_channel_id` indicating over which channel we received the payment.
 351                 via_user_channel_id: Option<u128>,
 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::PaymentClaimable`]. However, if we previously crashed during a
 357         /// [`ChannelManager::claim_funds`] call you may see this event without a corresponding
 358         /// [`Event::PaymentClaimable`] event.
 359         ///
 360         /// # Note
 361         /// LDK will not stop an inbound payment from being paid multiple times, so multiple
 362         /// `PaymentClaimable` events may be generated for the same payment. If you then call
 363         /// [`ChannelManager::claim_funds`] twice for the same [`Event::PaymentClaimable`] you may get
 364         /// multiple `PaymentClaimed` events.
 365         ///
 366         /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
 367         PaymentClaimed {
 368                 /// The node that received the payment.
 369                 /// This is useful to identify payments which were received via [phantom nodes].
 370                 /// This field will always be filled in when the event was generated by LDK versions
 371                 /// 0.0.113 and above.
 372                 ///
 373                 /// [phantom nodes]: crate::chain::keysinterface::PhantomKeysManager
 374                 receiver_node_id: Option<PublicKey>,
 375                 /// The payment hash of the claimed payment. Note that LDK will not stop you from
 376                 /// registering duplicate payment hashes for inbound payments.
 377                 payment_hash: PaymentHash,
 378                 /// The value, in thousandths of a satoshi, that this payment is for.
 379                 amount_msat: u64,
 380                 /// The purpose of the claimed payment, i.e. whether the payment was for an invoice or a
 381                 /// spontaneous payment.
 382                 purpose: PaymentPurpose,
 383         },
 384         /// Indicates an outbound payment we made succeeded (i.e. it made it all the way to its target
 385         /// and we got back the payment preimage for it).
 386         ///
 387         /// Note for MPP payments: in rare cases, this event may be preceded by a `PaymentPathFailed`
 388         /// event. In this situation, you SHOULD treat this payment as having succeeded.
 389         PaymentSent {
 390                 /// The `payment_id` passed to [`ChannelManager::send_payment`].
 391                 ///
 392                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 393                 payment_id: Option<PaymentId>,
 394                 /// The preimage to the hash given to ChannelManager::send_payment.
 395                 /// Note that this serves as a payment receipt, if you wish to have such a thing, you must
 396                 /// store it somehow!
 397                 payment_preimage: PaymentPreimage,
 398                 /// The hash that was given to [`ChannelManager::send_payment`].
 399                 ///
 400                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 401                 payment_hash: PaymentHash,
 402                 /// The total fee which was spent at intermediate hops in this payment, across all paths.
 403                 ///
 404                 /// Note that, like [`Route::get_total_fees`] this does *not* include any potential
 405                 /// overpayment to the recipient node.
 406                 ///
 407                 /// If the recipient or an intermediate node misbehaves and gives us free money, this may
 408                 /// overstate the amount paid, though this is unlikely.
 409                 ///
 410                 /// [`Route::get_total_fees`]: crate::routing::router::Route::get_total_fees
 411                 fee_paid_msat: Option<u64>,
 412         },
 413         /// Indicates an outbound payment failed. Individual [`Event::PaymentPathFailed`] events
 414         /// provide failure information for each path attempt in the payment, including retries.
 415         ///
 416         /// This event is provided once there are no further pending HTLCs for the payment and the
 417         /// payment is no longer retryable, due either to the [`Retry`] provided or
 418         /// [`ChannelManager::abandon_payment`] having been called for the corresponding payment.
 419         ///
 420         /// [`Retry`]: crate::ln::channelmanager::Retry
 421         /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 422         PaymentFailed {
 423                 /// The `payment_id` passed to [`ChannelManager::send_payment`].
 424                 ///
 425                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 426                 payment_id: PaymentId,
 427                 /// The hash that was given to [`ChannelManager::send_payment`].
 428                 ///
 429                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 430                 payment_hash: PaymentHash,
 431         },
 432         /// Indicates that a path for an outbound payment was successful.
 433         ///
 434         /// Always generated after [`Event::PaymentSent`] and thus useful for scoring channels. See
 435         /// [`Event::PaymentSent`] for obtaining the payment preimage.
 436         PaymentPathSuccessful {
 437                 /// The `payment_id` passed to [`ChannelManager::send_payment`].
 438                 ///
 439                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 440                 payment_id: PaymentId,
 441                 /// The hash that was given to [`ChannelManager::send_payment`].
 442                 ///
 443                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 444                 payment_hash: Option<PaymentHash>,
 445                 /// The payment path that was successful.
 446                 ///
 447                 /// May contain a closed channel if the HTLC sent along the path was fulfilled on chain.
 448                 path: Vec<RouteHop>,
 449         },
 450         /// Indicates an outbound HTLC we sent failed, likely due to an intermediary node being unable to
 451         /// handle the HTLC.
 452         ///
 453         /// Note that this does *not* indicate that all paths for an MPP payment have failed, see
 454         /// [`Event::PaymentFailed`].
 455         ///
 456         /// See [`ChannelManager::abandon_payment`] for giving up on this payment before its retries have
 457         /// been exhausted.
 458         ///
 459         /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 460         PaymentPathFailed {
 461                 /// The `payment_id` passed to [`ChannelManager::send_payment`].
 462                 ///
 463                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 464                 /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 465                 payment_id: Option<PaymentId>,
 466                 /// The hash that was given to [`ChannelManager::send_payment`].
 467                 ///
 468                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 469                 payment_hash: PaymentHash,
 470                 /// Indicates the payment was rejected for some reason by the recipient. This implies that
 471                 /// the payment has failed, not just the route in question. If this is not set, the payment may
 472                 /// be retried via a different route.
 473                 payment_failed_permanently: bool,
 474                 /// Extra error details based on the failure type. May contain an update that needs to be
 475                 /// applied to the [`NetworkGraph`].
 476                 ///
 477                 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
 478                 failure: PathFailure,
 479                 /// The payment path that failed.
 480                 path: Vec<RouteHop>,
 481                 /// The channel responsible for the failed payment path.
 482                 ///
 483                 /// Note that for route hints or for the first hop in a path this may be an SCID alias and
 484                 /// may not refer to a channel in the public network graph. These aliases may also collide
 485                 /// with channels in the public network graph.
 486                 ///
 487                 /// If this is `Some`, then the corresponding channel should be avoided when the payment is
 488                 /// retried. May be `None` for older [`Event`] serializations.
 489                 short_channel_id: Option<u64>,
 490 #[cfg(test)]
 491                 error_code: Option<u16>,
 492 #[cfg(test)]
 493                 error_data: Option<Vec<u8>>,
 494         },
 495         /// Indicates that a probe payment we sent returned successful, i.e., only failed at the destination.
 496         ProbeSuccessful {
 497                 /// The id returned by [`ChannelManager::send_probe`].
 498                 ///
 499                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
 500                 payment_id: PaymentId,
 501                 /// The hash generated by [`ChannelManager::send_probe`].
 502                 ///
 503                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
 504                 payment_hash: PaymentHash,
 505                 /// The payment path that was successful.
 506                 path: Vec<RouteHop>,
 507         },
 508         /// Indicates that a probe payment we sent failed at an intermediary node on the path.
 509         ProbeFailed {
 510                 /// The id returned by [`ChannelManager::send_probe`].
 511                 ///
 512                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
 513                 payment_id: PaymentId,
 514                 /// The hash generated by [`ChannelManager::send_probe`].
 515                 ///
 516                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
 517                 payment_hash: PaymentHash,
 518                 /// The payment path that failed.
 519                 path: Vec<RouteHop>,
 520                 /// The channel responsible for the failed probe.
 521                 ///
 522                 /// Note that for route hints or for the first hop in a path this may be an SCID alias and
 523                 /// may not refer to a channel in the public network graph. These aliases may also collide
 524                 /// with channels in the public network graph.
 525                 short_channel_id: Option<u64>,
 526         },
 527         /// Used to indicate that [`ChannelManager::process_pending_htlc_forwards`] should be called at
 528         /// a time in the future.
 529         ///
 530         /// [`ChannelManager::process_pending_htlc_forwards`]: crate::ln::channelmanager::ChannelManager::process_pending_htlc_forwards
 531         PendingHTLCsForwardable {
 532                 /// The minimum amount of time that should be waited prior to calling
 533                 /// process_pending_htlc_forwards. To increase the effort required to correlate payments,
 534                 /// you should wait a random amount of time in roughly the range (now + time_forwardable,
 535                 /// now + 5*time_forwardable).
 536                 time_forwardable: Duration,
 537         },
 538         /// Used to indicate that we've intercepted an HTLC forward. This event will only be generated if
 539         /// you've encoded an intercept scid in the receiver's invoice route hints using
 540         /// [`ChannelManager::get_intercept_scid`] and have set [`UserConfig::accept_intercept_htlcs`].
 541         ///
 542         /// [`ChannelManager::forward_intercepted_htlc`] or
 543         /// [`ChannelManager::fail_intercepted_htlc`] MUST be called in response to this event. See
 544         /// their docs for more information.
 545         ///
 546         /// [`ChannelManager::get_intercept_scid`]: crate::ln::channelmanager::ChannelManager::get_intercept_scid
 547         /// [`UserConfig::accept_intercept_htlcs`]: crate::util::config::UserConfig::accept_intercept_htlcs
 548         /// [`ChannelManager::forward_intercepted_htlc`]: crate::ln::channelmanager::ChannelManager::forward_intercepted_htlc
 549         /// [`ChannelManager::fail_intercepted_htlc`]: crate::ln::channelmanager::ChannelManager::fail_intercepted_htlc
 550         HTLCIntercepted {
 551                 /// An id to help LDK identify which HTLC is being forwarded or failed.
 552                 intercept_id: InterceptId,
 553                 /// The fake scid that was programmed as the next hop's scid, generated using
 554                 /// [`ChannelManager::get_intercept_scid`].
 555                 ///
 556                 /// [`ChannelManager::get_intercept_scid`]: crate::ln::channelmanager::ChannelManager::get_intercept_scid
 557                 requested_next_hop_scid: u64,
 558                 /// The payment hash used for this HTLC.
 559                 payment_hash: PaymentHash,
 560                 /// How many msats were received on the inbound edge of this HTLC.
 561                 inbound_amount_msat: u64,
 562                 /// How many msats the payer intended to route to the next node. Depending on the reason you are
 563                 /// intercepting this payment, you might take a fee by forwarding less than this amount.
 564                 ///
 565                 /// Note that LDK will NOT check that expected fees were factored into this value. You MUST
 566                 /// check that whatever fee you want has been included here or subtract it as required. Further,
 567                 /// LDK will not stop you from forwarding more than you received.
 568                 expected_outbound_amount_msat: u64,
 569         },
 570         /// Used to indicate that an output which you should know how to spend was confirmed on chain
 571         /// and is now spendable.
 572         /// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
 573         /// counterparty spending them due to some kind of timeout. Thus, you need to store them
 574         /// somewhere and spend them when you create on-chain transactions.
 575         SpendableOutputs {
 576                 /// The outputs which you should store as spendable by you.
 577                 outputs: Vec<SpendableOutputDescriptor>,
 578         },
 579         /// This event is generated when a payment has been successfully forwarded through us and a
 580         /// forwarding fee earned.
 581         PaymentForwarded {
 582                 /// The incoming channel between the previous node and us. This is only `None` for events
 583                 /// generated or serialized by versions prior to 0.0.107.
 584                 prev_channel_id: Option<[u8; 32]>,
 585                 /// The outgoing channel between the next node and us. This is only `None` for events
 586                 /// generated or serialized by versions prior to 0.0.107.
 587                 next_channel_id: Option<[u8; 32]>,
 588                 /// The fee, in milli-satoshis, which was earned as a result of the payment.
 589                 ///
 590                 /// Note that if we force-closed the channel over which we forwarded an HTLC while the HTLC
 591                 /// was pending, the amount the next hop claimed will have been rounded down to the nearest
 592                 /// whole satoshi. Thus, the fee calculated here may be higher than expected as we still
 593                 /// claimed the full value in millisatoshis from the source. In this case,
 594                 /// `claim_from_onchain_tx` will be set.
 595                 ///
 596                 /// If the channel which sent us the payment has been force-closed, we will claim the funds
 597                 /// via an on-chain transaction. In that case we do not yet know the on-chain transaction
 598                 /// fees which we will spend and will instead set this to `None`. It is possible duplicate
 599                 /// `PaymentForwarded` events are generated for the same payment iff `fee_earned_msat` is
 600                 /// `None`.
 601                 fee_earned_msat: Option<u64>,
 602                 /// If this is `true`, the forwarded HTLC was claimed by our counterparty via an on-chain
 603                 /// transaction.
 604                 claim_from_onchain_tx: bool,
 605                 /// The final amount forwarded, in milli-satoshis, after the fee is deducted.
 606                 ///
 607                 /// The caveat described above the `fee_earned_msat` field applies here as well.
 608                 outbound_amount_forwarded_msat: Option<u64>,
 609         },
 610         /// Used to indicate that a channel with the given `channel_id` is being opened and pending
 611         /// confirmation on-chain.
 612         ///
 613         /// This event is emitted when the funding transaction has been signed and is broadcast to the
 614         /// network. For 0conf channels it will be immediately followed by the corresponding
 615         /// [`Event::ChannelReady`] event.
 616         ChannelPending {
 617                 /// The `channel_id` of the channel that is pending confirmation.
 618                 channel_id: [u8; 32],
 619                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
 620                 /// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
 621                 /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
 622                 /// `user_channel_id` will be randomized for an inbound channel.
 623                 ///
 624                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
 625                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 626                 /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
 627                 user_channel_id: u128,
 628                 /// The `temporary_channel_id` this channel used to be known by during channel establishment.
 629                 ///
 630                 /// Will be `None` for channels created prior to LDK version 0.0.115.
 631                 former_temporary_channel_id: Option<[u8; 32]>,
 632                 /// The `node_id` of the channel counterparty.
 633                 counterparty_node_id: PublicKey,
 634                 /// The outpoint of the channel's funding transaction.
 635                 funding_txo: OutPoint,
 636         },
 637         /// Used to indicate that a channel with the given `channel_id` is ready to
 638         /// be used. This event is emitted either when the funding transaction has been confirmed
 639         /// on-chain, or, in case of a 0conf channel, when both parties have confirmed the channel
 640         /// establishment.
 641         ChannelReady {
 642                 /// The `channel_id` of the channel that is ready.
 643                 channel_id: [u8; 32],
 644                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
 645                 /// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
 646                 /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
 647                 /// `user_channel_id` will be randomized for an inbound channel.
 648                 ///
 649                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
 650                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 651                 /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
 652                 user_channel_id: u128,
 653                 /// The `node_id` of the channel counterparty.
 654                 counterparty_node_id: PublicKey,
 655                 /// The features that this channel will operate with.
 656                 channel_type: ChannelTypeFeatures,
 657         },
 658         /// Used to indicate that a previously opened channel with the given `channel_id` is in the
 659         /// process of closure.
 660         ChannelClosed  {
 661                 /// The `channel_id` of the channel which has been closed. Note that on-chain transactions
 662                 /// resolving the channel are likely still awaiting confirmation.
 663                 channel_id: [u8; 32],
 664                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
 665                 /// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
 666                 /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
 667                 /// `user_channel_id` will be randomized for inbound channels.
 668                 /// This may be zero for inbound channels serialized prior to 0.0.113 and will always be
 669                 /// zero for objects serialized with LDK versions prior to 0.0.102.
 670                 ///
 671                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
 672                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 673                 /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
 674                 user_channel_id: u128,
 675                 /// The reason the channel was closed.
 676                 reason: ClosureReason
 677         },
 678         /// Used to indicate to the user that they can abandon the funding transaction and recycle the
 679         /// inputs for another purpose.
 680         DiscardFunding {
 681                 /// The channel_id of the channel which has been closed.
 682                 channel_id: [u8; 32],
 683                 /// The full transaction received from the user
 684                 transaction: Transaction
 685         },
 686         /// Indicates a request to open a new channel by a peer.
 687         ///
 688         /// To accept the request, call [`ChannelManager::accept_inbound_channel`]. To reject the
 689         /// request, call [`ChannelManager::force_close_without_broadcasting_txn`].
 690         ///
 691         /// The event is only triggered when a new open channel request is received and the
 692         /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true.
 693         ///
 694         /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 695         /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
 696         /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
 697         OpenChannelRequest {
 698                 /// The temporary channel ID of the channel requested to be opened.
 699                 ///
 700                 /// When responding to the request, the `temporary_channel_id` should be passed
 701                 /// back to the ChannelManager through [`ChannelManager::accept_inbound_channel`] to accept,
 702                 /// or through [`ChannelManager::force_close_without_broadcasting_txn`] to reject.
 703                 ///
 704                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 705                 /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
 706                 temporary_channel_id: [u8; 32],
 707                 /// The node_id of the counterparty requesting to open the channel.
 708                 ///
 709                 /// When responding to the request, the `counterparty_node_id` should be passed
 710                 /// back to the `ChannelManager` through [`ChannelManager::accept_inbound_channel`] to
 711                 /// accept the request, or through [`ChannelManager::force_close_without_broadcasting_txn`] to reject the
 712                 /// request.
 713                 ///
 714                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 715                 /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
 716                 counterparty_node_id: PublicKey,
 717                 /// The channel value of the requested channel.
 718                 funding_satoshis: u64,
 719                 /// Our starting balance in the channel if the request is accepted, in milli-satoshi.
 720                 push_msat: u64,
 721                 /// The features that this channel will operate with. If you reject the channel, a
 722                 /// well-behaved counterparty may automatically re-attempt the channel with a new set of
 723                 /// feature flags.
 724                 ///
 725                 /// Note that if [`ChannelTypeFeatures::supports_scid_privacy`] returns true on this type,
 726                 /// the resulting [`ChannelManager`] will not be readable by versions of LDK prior to
 727                 /// 0.0.106.
 728                 ///
 729                 /// Furthermore, note that if [`ChannelTypeFeatures::supports_zero_conf`] returns true on this type,
 730                 /// the resulting [`ChannelManager`] will not be readable by versions of LDK prior to
 731                 /// 0.0.107. Channels setting this type also need to get manually accepted via
 732                 /// [`crate::ln::channelmanager::ChannelManager::accept_inbound_channel_from_trusted_peer_0conf`],
 733                 /// or will be rejected otherwise.
 734                 ///
 735                 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 736                 channel_type: ChannelTypeFeatures,
 737         },
 738         /// Indicates that the HTLC was accepted, but could not be processed when or after attempting to
 739         /// forward it.
 740         ///
 741         /// Some scenarios where this event may be sent include:
 742         /// * Insufficient capacity in the outbound channel
 743         /// * While waiting to forward the HTLC, the channel it is meant to be forwarded through closes
 744         /// * When an unknown SCID is requested for forwarding a payment.
 745         /// * Expected MPP amount has already been reached
 746         /// * The HTLC has timed out
 747         ///
 748         /// This event, however, does not get generated if an HTLC fails to meet the forwarding
 749         /// requirements (i.e. insufficient fees paid, or a CLTV that is too soon).
 750         HTLCHandlingFailed {
 751                 /// The channel over which the HTLC was received.
 752                 prev_channel_id: [u8; 32],
 753                 /// Destination of the HTLC that failed to be processed.
 754                 failed_next_destination: HTLCDestination,
 755         },
 756         #[cfg(anchors)]
 757         /// Indicates that a transaction originating from LDK needs to have its fee bumped. This event
 758         /// requires confirmed external funds to be readily available to spend.
 759         ///
 760         /// LDK does not currently generate this event. It is limited to the scope of channels with
 761         /// anchor outputs, which will be introduced in a future release.
 762         BumpTransaction(BumpTransactionEvent),
 763 }
 764
 765 impl Writeable for Event {
 766         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 767                 match self {
 768                         &Event::FundingGenerationReady { .. } => {
 769                                 0u8.write(writer)?;
 770                                 // We never write out FundingGenerationReady events as, upon disconnection, peers
 771                                 // drop any channels which have not yet exchanged funding_signed.
 772                         },
 773                         &Event::PaymentClaimable { ref payment_hash, ref amount_msat, ref purpose, ref receiver_node_id, ref via_channel_id, ref via_user_channel_id } => {
 774                                 1u8.write(writer)?;
 775                                 let mut payment_secret = None;
 776                                 let payment_preimage;
 777                                 match &purpose {
 778                                         PaymentPurpose::InvoicePayment { payment_preimage: preimage, payment_secret: secret } => {
 779                                                 payment_secret = Some(secret);
 780                                                 payment_preimage = *preimage;
 781                                         },
 782                                         PaymentPurpose::SpontaneousPayment(preimage) => {
 783                                                 payment_preimage = Some(*preimage);
 784                                         }
 785                                 }
 786                                 write_tlv_fields!(writer, {
 787                                         (0, payment_hash, required),
 788                                         (1, receiver_node_id, option),
 789                                         (2, payment_secret, option),
 790                                         (3, via_channel_id, option),
 791                                         (4, amount_msat, required),
 792                                         (5, via_user_channel_id, option),
 793                                         (6, 0u64, required), // user_payment_id required for compatibility with 0.0.103 and earlier
 794                                         (8, payment_preimage, option),
 795                                 });
 796                         },
 797                         &Event::PaymentSent { ref payment_id, ref payment_preimage, ref payment_hash, ref fee_paid_msat } => {
 798                                 2u8.write(writer)?;
 799                                 write_tlv_fields!(writer, {
 800                                         (0, payment_preimage, required),
 801                                         (1, payment_hash, required),
 802                                         (3, payment_id, option),
 803                                         (5, fee_paid_msat, option),
 804                                 });
 805                         },
 806                         &Event::PaymentPathFailed {
 807                                 ref payment_id, ref payment_hash, ref payment_failed_permanently, ref failure,
 808                                 ref path, ref short_channel_id,
 809                                 #[cfg(test)]
 810                                 ref error_code,
 811                                 #[cfg(test)]
 812                                 ref error_data,
 813                         } => {
 814                                 3u8.write(writer)?;
 815                                 #[cfg(test)]
 816                                 error_code.write(writer)?;
 817                                 #[cfg(test)]
 818                                 error_data.write(writer)?;
 819                                 write_tlv_fields!(writer, {
 820                                         (0, payment_hash, required),
 821                                         (1, None::<NetworkUpdate>, option), // network_update in LDK versions prior to 0.0.114
 822                                         (2, payment_failed_permanently, required),
 823                                         (3, false, required), // all_paths_failed in LDK versions prior to 0.0.114
 824                                         (5, *path, vec_type),
 825                                         (7, short_channel_id, option),
 826                                         (9, None::<RouteParameters>, option), // retry in LDK versions prior to 0.0.115
 827                                         (11, payment_id, option),
 828                                         (13, failure, required),
 829                                 });
 830                         },
 831                         &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
 832                                 4u8.write(writer)?;
 833                                 // Note that we now ignore these on the read end as we'll re-generate them in
 834                                 // ChannelManager, we write them here only for backwards compatibility.
 835                         },
 836                         &Event::SpendableOutputs { ref outputs } => {
 837                                 5u8.write(writer)?;
 838                                 write_tlv_fields!(writer, {
 839                                         (0, WithoutLength(outputs), required),
 840                                 });
 841                         },
 842                         &Event::HTLCIntercepted { requested_next_hop_scid, payment_hash, inbound_amount_msat, expected_outbound_amount_msat, intercept_id } => {
 843                                 6u8.write(writer)?;
 844                                 let intercept_scid = InterceptNextHop::FakeScid { requested_next_hop_scid };
 845                                 write_tlv_fields!(writer, {
 846                                         (0, intercept_id, required),
 847                                         (2, intercept_scid, required),
 848                                         (4, payment_hash, required),
 849                                         (6, inbound_amount_msat, required),
 850                                         (8, expected_outbound_amount_msat, required),
 851                                 });
 852                         }
 853                         &Event::PaymentForwarded {
 854                                 fee_earned_msat, prev_channel_id, claim_from_onchain_tx,
 855                                 next_channel_id, outbound_amount_forwarded_msat
 856                         } => {
 857                                 7u8.write(writer)?;
 858                                 write_tlv_fields!(writer, {
 859                                         (0, fee_earned_msat, option),
 860                                         (1, prev_channel_id, option),
 861                                         (2, claim_from_onchain_tx, required),
 862                                         (3, next_channel_id, option),
 863                                         (5, outbound_amount_forwarded_msat, option),
 864                                 });
 865                         },
 866                         &Event::ChannelClosed { ref channel_id, ref user_channel_id, ref reason } => {
 867                                 9u8.write(writer)?;
 868                                 // `user_channel_id` used to be a single u64 value. In order to remain backwards
 869                                 // compatible with versions prior to 0.0.113, the u128 is serialized as two
 870                                 // separate u64 values.
 871                                 let user_channel_id_low = *user_channel_id as u64;
 872                                 let user_channel_id_high = (*user_channel_id >> 64) as u64;
 873                                 write_tlv_fields!(writer, {
 874                                         (0, channel_id, required),
 875                                         (1, user_channel_id_low, required),
 876                                         (2, reason, required),
 877                                         (3, user_channel_id_high, required),
 878                                 });
 879                         },
 880                         &Event::DiscardFunding { ref channel_id, ref transaction } => {
 881                                 11u8.write(writer)?;
 882                                 write_tlv_fields!(writer, {
 883                                         (0, channel_id, required),
 884                                         (2, transaction, required)
 885                                 })
 886                         },
 887                         &Event::PaymentPathSuccessful { ref payment_id, ref payment_hash, ref path } => {
 888                                 13u8.write(writer)?;
 889                                 write_tlv_fields!(writer, {
 890                                         (0, payment_id, required),
 891                                         (2, payment_hash, option),
 892                                         (4, *path, vec_type)
 893                                 })
 894                         },
 895                         &Event::PaymentFailed { ref payment_id, ref payment_hash } => {
 896                                 15u8.write(writer)?;
 897                                 write_tlv_fields!(writer, {
 898                                         (0, payment_id, required),
 899                                         (2, payment_hash, required),
 900                                 })
 901                         },
 902                         &Event::OpenChannelRequest { .. } => {
 903                                 17u8.write(writer)?;
 904                                 // We never write the OpenChannelRequest events as, upon disconnection, peers
 905                                 // drop any channels which have not yet exchanged funding_signed.
 906                         },
 907                         &Event::PaymentClaimed { ref payment_hash, ref amount_msat, ref purpose, ref receiver_node_id } => {
 908                                 19u8.write(writer)?;
 909                                 write_tlv_fields!(writer, {
 910                                         (0, payment_hash, required),
 911                                         (1, receiver_node_id, option),
 912                                         (2, purpose, required),
 913                                         (4, amount_msat, required),
 914                                 });
 915                         },
 916                         &Event::ProbeSuccessful { ref payment_id, ref payment_hash, ref path } => {
 917                                 21u8.write(writer)?;
 918                                 write_tlv_fields!(writer, {
 919                                         (0, payment_id, required),
 920                                         (2, payment_hash, required),
 921                                         (4, *path, vec_type)
 922                                 })
 923                         },
 924                         &Event::ProbeFailed { ref payment_id, ref payment_hash, ref path, ref short_channel_id } => {
 925                                 23u8.write(writer)?;
 926                                 write_tlv_fields!(writer, {
 927                                         (0, payment_id, required),
 928                                         (2, payment_hash, required),
 929                                         (4, *path, vec_type),
 930                                         (6, short_channel_id, option),
 931                                 })
 932                         },
 933                         &Event::HTLCHandlingFailed { ref prev_channel_id, ref failed_next_destination } => {
 934                                 25u8.write(writer)?;
 935                                 write_tlv_fields!(writer, {
 936                                         (0, prev_channel_id, required),
 937                                         (2, failed_next_destination, required),
 938                                 })
 939                         },
 940                         #[cfg(anchors)]
 941                         &Event::BumpTransaction(ref event)=> {
 942                                 27u8.write(writer)?;
 943                                 match event {
 944                                         // We never write the ChannelClose|HTLCResolution events as they'll be replayed
 945                                         // upon restarting anyway if they remain unresolved.
 946                                         BumpTransactionEvent::ChannelClose { .. } => {}
 947                                         BumpTransactionEvent::HTLCResolution { .. } => {}
 948                                 }
 949                                 write_tlv_fields!(writer, {}); // Write a length field for forwards compat
 950                         }
 951                         &Event::ChannelReady { ref channel_id, ref user_channel_id, ref counterparty_node_id, ref channel_type } => {
 952                                 29u8.write(writer)?;
 953                                 write_tlv_fields!(writer, {
 954                                         (0, channel_id, required),
 955                                         (2, user_channel_id, required),
 956                                         (4, counterparty_node_id, required),
 957                                         (6, channel_type, required),
 958                                 });
 959                         },
 960                         &Event::ChannelPending { ref channel_id, ref user_channel_id, ref former_temporary_channel_id, ref counterparty_node_id, ref funding_txo } => {
 961                                 31u8.write(writer)?;
 962                                 write_tlv_fields!(writer, {
 963                                         (0, channel_id, required),
 964                                         (2, user_channel_id, required),
 965                                         (4, former_temporary_channel_id, required),
 966                                         (6, counterparty_node_id, required),
 967                                         (8, funding_txo, required),
 968                                 });
 969                         },
 970                         // Note that, going forward, all new events must only write data inside of
 971                         // `write_tlv_fields`. Versions 0.0.101+ will ignore odd-numbered events that write
 972                         // data via `write_tlv_fields`.
 973                 }
 974                 Ok(())
 975         }
 976 }
 977 impl MaybeReadable for Event {
 978         fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
 979                 match Readable::read(reader)? {
 980                         // Note that we do not write a length-prefixed TLV for FundingGenerationReady events,
 981                         // unlike all other events, thus we return immediately here.
 982                         0u8 => Ok(None),
 983                         1u8 => {
 984                                 let f = || {
 985                                         let mut payment_hash = PaymentHash([0; 32]);
 986                                         let mut payment_preimage = None;
 987                                         let mut payment_secret = None;
 988                                         let mut amount_msat = 0;
 989                                         let mut receiver_node_id = None;
 990                                         let mut _user_payment_id = None::<u64>; // For compatibility with 0.0.103 and earlier
 991                                         let mut via_channel_id = None;
 992                                         let mut via_user_channel_id = None;
 993                                         read_tlv_fields!(reader, {
 994                                                 (0, payment_hash, required),
 995                                                 (1, receiver_node_id, option),
 996                                                 (2, payment_secret, option),
 997                                                 (3, via_channel_id, option),
 998                                                 (4, amount_msat, required),
 999                                                 (5, via_user_channel_id, option),
1000                                                 (6, _user_payment_id, option),
1001                                                 (8, payment_preimage, option),
1002                                         });
1003                                         let purpose = match payment_secret {
1004                                                 Some(secret) => PaymentPurpose::InvoicePayment {
1005                                                         payment_preimage,
1006                                                         payment_secret: secret
1007                                                 },
1008                                                 None if payment_preimage.is_some() => PaymentPurpose::SpontaneousPayment(payment_preimage.unwrap()),
1009                                                 None => return Err(msgs::DecodeError::InvalidValue),
1010                                         };
1011                                         Ok(Some(Event::PaymentClaimable {
1012                                                 receiver_node_id,
1013                                                 payment_hash,
1014                                                 amount_msat,
1015                                                 purpose,
1016                                                 via_channel_id,
1017                                                 via_user_channel_id,
1018                                         }))
1019                                 };
1020                                 f()
1021                         },
1022                         2u8 => {
1023                                 let f = || {
1024                                         let mut payment_preimage = PaymentPreimage([0; 32]);
1025                                         let mut payment_hash = None;
1026                                         let mut payment_id = None;
1027                                         let mut fee_paid_msat = None;
1028                                         read_tlv_fields!(reader, {
1029                                                 (0, payment_preimage, required),
1030                                                 (1, payment_hash, option),
1031                                                 (3, payment_id, option),
1032                                                 (5, fee_paid_msat, option),
1033                                         });
1034                                         if payment_hash.is_none() {
1035                                                 payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()));
1036                                         }
1037                                         Ok(Some(Event::PaymentSent {
1038                                                 payment_id,
1039                                                 payment_preimage,
1040                                                 payment_hash: payment_hash.unwrap(),
1041                                                 fee_paid_msat,
1042                                         }))
1043                                 };
1044                                 f()
1045                         },
1046                         3u8 => {
1047                                 let f = || {
1048                                         #[cfg(test)]
1049                                         let error_code = Readable::read(reader)?;
1050                                         #[cfg(test)]
1051                                         let error_data = Readable::read(reader)?;
1052                                         let mut payment_hash = PaymentHash([0; 32]);
1053                                         let mut payment_failed_permanently = false;
1054                                         let mut network_update = None;
1055                                         let mut path: Option<Vec<RouteHop>> = Some(vec![]);
1056                                         let mut short_channel_id = None;
1057                                         let mut payment_id = None;
1058                                         let mut failure_opt = None;
1059                                         read_tlv_fields!(reader, {
1060                                                 (0, payment_hash, required),
1061                                                 (1, network_update, upgradable_option),
1062                                                 (2, payment_failed_permanently, required),
1063                                                 (5, path, vec_type),
1064                                                 (7, short_channel_id, option),
1065                                                 (11, payment_id, option),
1066                                                 (13, failure_opt, upgradable_option),
1067                                         });
1068                                         let failure = failure_opt.unwrap_or_else(|| PathFailure::OnPath { network_update });
1069                                         Ok(Some(Event::PaymentPathFailed {
1070                                                 payment_id,
1071                                                 payment_hash,
1072                                                 payment_failed_permanently,
1073                                                 failure,
1074                                                 path: path.unwrap(),
1075                                                 short_channel_id,
1076                                                 #[cfg(test)]
1077                                                 error_code,
1078                                                 #[cfg(test)]
1079                                                 error_data,
1080                                         }))
1081                                 };
1082                                 f()
1083                         },
1084                         4u8 => Ok(None),
1085                         5u8 => {
1086                                 let f = || {
1087                                         let mut outputs = WithoutLength(Vec::new());
1088                                         read_tlv_fields!(reader, {
1089                                                 (0, outputs, required),
1090                                         });
1091                                         Ok(Some(Event::SpendableOutputs { outputs: outputs.0 }))
1092                                 };
1093                                 f()
1094                         },
1095                         6u8 => {
1096                                 let mut payment_hash = PaymentHash([0; 32]);
1097                                 let mut intercept_id = InterceptId([0; 32]);
1098                                 let mut requested_next_hop_scid = InterceptNextHop::FakeScid { requested_next_hop_scid: 0 };
1099                                 let mut inbound_amount_msat = 0;
1100                                 let mut expected_outbound_amount_msat = 0;
1101                                 read_tlv_fields!(reader, {
1102                                         (0, intercept_id, required),
1103                                         (2, requested_next_hop_scid, required),
1104                                         (4, payment_hash, required),
1105                                         (6, inbound_amount_msat, required),
1106                                         (8, expected_outbound_amount_msat, required),
1107                                 });
1108                                 let next_scid = match requested_next_hop_scid {
1109                                         InterceptNextHop::FakeScid { requested_next_hop_scid: scid } => scid
1110                                 };
1111                                 Ok(Some(Event::HTLCIntercepted {
1112                                         payment_hash,
1113                                         requested_next_hop_scid: next_scid,
1114                                         inbound_amount_msat,
1115                                         expected_outbound_amount_msat,
1116                                         intercept_id,
1117                                 }))
1118                         },
1119                         7u8 => {
1120                                 let f = || {
1121                                         let mut fee_earned_msat = None;
1122                                         let mut prev_channel_id = None;
1123                                         let mut claim_from_onchain_tx = false;
1124                                         let mut next_channel_id = None;
1125                                         let mut outbound_amount_forwarded_msat = None;
1126                                         read_tlv_fields!(reader, {
1127                                                 (0, fee_earned_msat, option),
1128                                                 (1, prev_channel_id, option),
1129                                                 (2, claim_from_onchain_tx, required),
1130                                                 (3, next_channel_id, option),
1131                                                 (5, outbound_amount_forwarded_msat, option),
1132                                         });
1133                                         Ok(Some(Event::PaymentForwarded {
1134                                                 fee_earned_msat, prev_channel_id, claim_from_onchain_tx, next_channel_id,
1135                                                 outbound_amount_forwarded_msat
1136                                         }))
1137                                 };
1138                                 f()
1139                         },
1140                         9u8 => {
1141                                 let f = || {
1142                                         let mut channel_id = [0; 32];
1143                                         let mut reason = UpgradableRequired(None);
1144                                         let mut user_channel_id_low_opt: Option<u64> = None;
1145                                         let mut user_channel_id_high_opt: Option<u64> = None;
1146                                         read_tlv_fields!(reader, {
1147                                                 (0, channel_id, required),
1148                                                 (1, user_channel_id_low_opt, option),
1149                                                 (2, reason, upgradable_required),
1150                                                 (3, user_channel_id_high_opt, option),
1151                                         });
1152
1153                                         // `user_channel_id` used to be a single u64 value. In order to remain
1154                                         // backwards compatible with versions prior to 0.0.113, the u128 is serialized
1155                                         // as two separate u64 values.
1156                                         let user_channel_id = (user_channel_id_low_opt.unwrap_or(0) as u128) +
1157                                                 ((user_channel_id_high_opt.unwrap_or(0) as u128) << 64);
1158
1159                                         Ok(Some(Event::ChannelClosed { channel_id, user_channel_id, reason: _init_tlv_based_struct_field!(reason, upgradable_required) }))
1160                                 };
1161                                 f()
1162                         },
1163                         11u8 => {
1164                                 let f = || {
1165                                         let mut channel_id = [0; 32];
1166                                         let mut transaction = Transaction{ version: 2, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
1167                                         read_tlv_fields!(reader, {
1168                                                 (0, channel_id, required),
1169                                                 (2, transaction, required),
1170                                         });
1171                                         Ok(Some(Event::DiscardFunding { channel_id, transaction } ))
1172                                 };
1173                                 f()
1174                         },
1175                         13u8 => {
1176                                 let f = || {
1177                                         let mut payment_id = PaymentId([0; 32]);
1178                                         let mut payment_hash = None;
1179                                         let mut path: Option<Vec<RouteHop>> = Some(vec![]);
1180                                         read_tlv_fields!(reader, {
1181                                                 (0, payment_id, required),
1182                                                 (2, payment_hash, option),
1183                                                 (4, path, vec_type),
1184                                         });
1185                                         Ok(Some(Event::PaymentPathSuccessful {
1186                                                 payment_id,
1187                                                 payment_hash,
1188                                                 path: path.unwrap(),
1189                                         }))
1190                                 };
1191                                 f()
1192                         },
1193                         15u8 => {
1194                                 let f = || {
1195                                         let mut payment_hash = PaymentHash([0; 32]);
1196                                         let mut payment_id = PaymentId([0; 32]);
1197                                         read_tlv_fields!(reader, {
1198                                                 (0, payment_id, required),
1199                                                 (2, payment_hash, required),
1200                                         });
1201                                         Ok(Some(Event::PaymentFailed {
1202                                                 payment_id,
1203                                                 payment_hash,
1204                                         }))
1205                                 };
1206                                 f()
1207                         },
1208                         17u8 => {
1209                                 // Value 17 is used for `Event::OpenChannelRequest`.
1210                                 Ok(None)
1211                         },
1212                         19u8 => {
1213                                 let f = || {
1214                                         let mut payment_hash = PaymentHash([0; 32]);
1215                                         let mut purpose = UpgradableRequired(None);
1216                                         let mut amount_msat = 0;
1217                                         let mut receiver_node_id = None;
1218                                         read_tlv_fields!(reader, {
1219                                                 (0, payment_hash, required),
1220                                                 (1, receiver_node_id, option),
1221                                                 (2, purpose, upgradable_required),
1222                                                 (4, amount_msat, required),
1223                                         });
1224                                         Ok(Some(Event::PaymentClaimed {
1225                                                 receiver_node_id,
1226                                                 payment_hash,
1227                                                 purpose: _init_tlv_based_struct_field!(purpose, upgradable_required),
1228                                                 amount_msat,
1229                                         }))
1230                                 };
1231                                 f()
1232                         },
1233                         21u8 => {
1234                                 let f = || {
1235                                         let mut payment_id = PaymentId([0; 32]);
1236                                         let mut payment_hash = PaymentHash([0; 32]);
1237                                         let mut path: Option<Vec<RouteHop>> = Some(vec![]);
1238                                         read_tlv_fields!(reader, {
1239                                                 (0, payment_id, required),
1240                                                 (2, payment_hash, required),
1241                                                 (4, path, vec_type),
1242                                         });
1243                                         Ok(Some(Event::ProbeSuccessful {
1244                                                 payment_id,
1245                                                 payment_hash,
1246                                                 path: path.unwrap(),
1247                                         }))
1248                                 };
1249                                 f()
1250                         },
1251                         23u8 => {
1252                                 let f = || {
1253                                         let mut payment_id = PaymentId([0; 32]);
1254                                         let mut payment_hash = PaymentHash([0; 32]);
1255                                         let mut path: Option<Vec<RouteHop>> = Some(vec![]);
1256                                         let mut short_channel_id = None;
1257                                         read_tlv_fields!(reader, {
1258                                                 (0, payment_id, required),
1259                                                 (2, payment_hash, required),
1260                                                 (4, path, vec_type),
1261                                                 (6, short_channel_id, option),
1262                                         });
1263                                         Ok(Some(Event::ProbeFailed {
1264                                                 payment_id,
1265                                                 payment_hash,
1266                                                 path: path.unwrap(),
1267                                                 short_channel_id,
1268                                         }))
1269                                 };
1270                                 f()
1271                         },
1272                         25u8 => {
1273                                 let f = || {
1274                                         let mut prev_channel_id = [0; 32];
1275                                         let mut failed_next_destination_opt = UpgradableRequired(None);
1276                                         read_tlv_fields!(reader, {
1277                                                 (0, prev_channel_id, required),
1278                                                 (2, failed_next_destination_opt, upgradable_required),
1279                                         });
1280                                         Ok(Some(Event::HTLCHandlingFailed {
1281                                                 prev_channel_id,
1282                                                 failed_next_destination: _init_tlv_based_struct_field!(failed_next_destination_opt, upgradable_required),
1283                                         }))
1284                                 };
1285                                 f()
1286                         },
1287                         27u8 => Ok(None),
1288                         29u8 => {
1289                                 let f = || {
1290                                         let mut channel_id = [0; 32];
1291                                         let mut user_channel_id: u128 = 0;
1292                                         let mut counterparty_node_id = RequiredWrapper(None);
1293                                         let mut channel_type = RequiredWrapper(None);
1294                                         read_tlv_fields!(reader, {
1295                                                 (0, channel_id, required),
1296                                                 (2, user_channel_id, required),
1297                                                 (4, counterparty_node_id, required),
1298                                                 (6, channel_type, required),
1299                                         });
1300
1301                                         Ok(Some(Event::ChannelReady {
1302                                                 channel_id,
1303                                                 user_channel_id,
1304                                                 counterparty_node_id: counterparty_node_id.0.unwrap(),
1305                                                 channel_type: channel_type.0.unwrap()
1306                                         }))
1307                                 };
1308                                 f()
1309                         },
1310                         31u8 => {
1311                                 let f = || {
1312                                         let mut channel_id = [0; 32];
1313                                         let mut user_channel_id: u128 = 0;
1314                                         let mut former_temporary_channel_id = None;
1315                                         let mut counterparty_node_id = RequiredWrapper(None);
1316                                         let mut funding_txo = RequiredWrapper(None);
1317                                         read_tlv_fields!(reader, {
1318                                                 (0, channel_id, required),
1319                                                 (2, user_channel_id, required),
1320                                                 (4, former_temporary_channel_id, required),
1321                                                 (6, counterparty_node_id, required),
1322                                                 (8, funding_txo, required),
1323                                         });
1324
1325                                         Ok(Some(Event::ChannelPending {
1326                                                 channel_id,
1327                                                 user_channel_id,
1328                                                 former_temporary_channel_id,
1329                                                 counterparty_node_id: counterparty_node_id.0.unwrap(),
1330                                                 funding_txo: funding_txo.0.unwrap()
1331                                         }))
1332                                 };
1333                                 f()
1334                         },
1335                         // Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue.
1336                         // Version 0.0.100 failed to properly ignore odd types, possibly resulting in corrupt
1337                         // reads.
1338                         x if x % 2 == 1 => {
1339                                 // If the event is of unknown type, assume it was written with `write_tlv_fields`,
1340                                 // which prefixes the whole thing with a length BigSize. Because the event is
1341                                 // odd-type unknown, we should treat it as `Ok(None)` even if it has some TLV
1342                                 // fields that are even. Thus, we avoid using `read_tlv_fields` and simply read
1343                                 // exactly the number of bytes specified, ignoring them entirely.
1344                                 let tlv_len: BigSize = Readable::read(reader)?;
1345                                 FixedLengthReader::new(reader, tlv_len.0)
1346                                         .eat_remaining().map_err(|_| msgs::DecodeError::ShortRead)?;
1347                                 Ok(None)
1348                         },
1349                         _ => Err(msgs::DecodeError::InvalidValue)
1350                 }
1351         }
1352 }
1353
1354 /// An event generated by ChannelManager which indicates a message should be sent to a peer (or
1355 /// broadcast to most peers).
1356 /// These events are handled by PeerManager::process_events if you are using a PeerManager.
1357 #[derive(Clone, Debug)]
1358 pub enum MessageSendEvent {
1359         /// Used to indicate that we've accepted a channel open and should send the accept_channel
1360         /// message provided to the given peer.
1361         SendAcceptChannel {
1362                 /// The node_id of the node which should receive this message
1363                 node_id: PublicKey,
1364                 /// The message which should be sent.
1365                 msg: msgs::AcceptChannel,
1366         },
1367         /// Used to indicate that we've initiated a channel open and should send the open_channel
1368         /// message provided to the given peer.
1369         SendOpenChannel {
1370                 /// The node_id of the node which should receive this message
1371                 node_id: PublicKey,
1372                 /// The message which should be sent.
1373                 msg: msgs::OpenChannel,
1374         },
1375         /// Used to indicate that a funding_created message should be sent to the peer with the given node_id.
1376         SendFundingCreated {
1377                 /// The node_id of the node which should receive this message
1378                 node_id: PublicKey,
1379                 /// The message which should be sent.
1380                 msg: msgs::FundingCreated,
1381         },
1382         /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id.
1383         SendFundingSigned {
1384                 /// The node_id of the node which should receive this message
1385                 node_id: PublicKey,
1386                 /// The message which should be sent.
1387                 msg: msgs::FundingSigned,
1388         },
1389         /// Used to indicate that a channel_ready message should be sent to the peer with the given node_id.
1390         SendChannelReady {
1391                 /// The node_id of the node which should receive these message(s)
1392                 node_id: PublicKey,
1393                 /// The channel_ready message which should be sent.
1394                 msg: msgs::ChannelReady,
1395         },
1396         /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
1397         SendAnnouncementSignatures {
1398                 /// The node_id of the node which should receive these message(s)
1399                 node_id: PublicKey,
1400                 /// The announcement_signatures message which should be sent.
1401                 msg: msgs::AnnouncementSignatures,
1402         },
1403         /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed
1404         /// message should be sent to the peer with the given node_id.
1405         UpdateHTLCs {
1406                 /// The node_id of the node which should receive these message(s)
1407                 node_id: PublicKey,
1408                 /// The update messages which should be sent. ALL messages in the struct should be sent!
1409                 updates: msgs::CommitmentUpdate,
1410         },
1411         /// Used to indicate that a revoke_and_ack message should be sent to the peer with the given node_id.
1412         SendRevokeAndACK {
1413                 /// The node_id of the node which should receive this message
1414                 node_id: PublicKey,
1415                 /// The message which should be sent.
1416                 msg: msgs::RevokeAndACK,
1417         },
1418         /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id.
1419         SendClosingSigned {
1420                 /// The node_id of the node which should receive this message
1421                 node_id: PublicKey,
1422                 /// The message which should be sent.
1423                 msg: msgs::ClosingSigned,
1424         },
1425         /// Used to indicate that a shutdown message should be sent to the peer with the given node_id.
1426         SendShutdown {
1427                 /// The node_id of the node which should receive this message
1428                 node_id: PublicKey,
1429                 /// The message which should be sent.
1430                 msg: msgs::Shutdown,
1431         },
1432         /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id.
1433         SendChannelReestablish {
1434                 /// The node_id of the node which should receive this message
1435                 node_id: PublicKey,
1436                 /// The message which should be sent.
1437                 msg: msgs::ChannelReestablish,
1438         },
1439         /// Used to send a channel_announcement and channel_update to a specific peer, likely on
1440         /// initial connection to ensure our peers know about our channels.
1441         SendChannelAnnouncement {
1442                 /// The node_id of the node which should receive this message
1443                 node_id: PublicKey,
1444                 /// The channel_announcement which should be sent.
1445                 msg: msgs::ChannelAnnouncement,
1446                 /// The followup channel_update which should be sent.
1447                 update_msg: msgs::ChannelUpdate,
1448         },
1449         /// Used to indicate that a channel_announcement and channel_update should be broadcast to all
1450         /// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
1451         ///
1452         /// Note that after doing so, you very likely (unless you did so very recently) want to
1453         /// broadcast a node_announcement (e.g. via [`PeerManager::broadcast_node_announcement`]). This
1454         /// ensures that any nodes which see our channel_announcement also have a relevant
1455         /// node_announcement, including relevant feature flags which may be important for routing
1456         /// through or to us.
1457         ///
1458         /// [`PeerManager::broadcast_node_announcement`]: crate::ln::peer_handler::PeerManager::broadcast_node_announcement
1459         BroadcastChannelAnnouncement {
1460                 /// The channel_announcement which should be sent.
1461                 msg: msgs::ChannelAnnouncement,
1462                 /// The followup channel_update which should be sent.
1463                 update_msg: Option<msgs::ChannelUpdate>,
1464         },
1465         /// Used to indicate that a channel_update should be broadcast to all peers.
1466         BroadcastChannelUpdate {
1467                 /// The channel_update which should be sent.
1468                 msg: msgs::ChannelUpdate,
1469         },
1470         /// Used to indicate that a node_announcement should be broadcast to all peers.
1471         BroadcastNodeAnnouncement {
1472                 /// The node_announcement which should be sent.
1473                 msg: msgs::NodeAnnouncement,
1474         },
1475         /// Used to indicate that a channel_update should be sent to a single peer.
1476         /// In contrast to [`Self::BroadcastChannelUpdate`], this is used when the channel is a
1477         /// private channel and we shouldn't be informing all of our peers of channel parameters.
1478         SendChannelUpdate {
1479                 /// The node_id of the node which should receive this message
1480                 node_id: PublicKey,
1481                 /// The channel_update which should be sent.
1482                 msg: msgs::ChannelUpdate,
1483         },
1484         /// Broadcast an error downstream to be handled
1485         HandleError {
1486                 /// The node_id of the node which should receive this message
1487                 node_id: PublicKey,
1488                 /// The action which should be taken.
1489                 action: msgs::ErrorAction
1490         },
1491         /// Query a peer for channels with funding transaction UTXOs in a block range.
1492         SendChannelRangeQuery {
1493                 /// The node_id of this message recipient
1494                 node_id: PublicKey,
1495                 /// The query_channel_range which should be sent.
1496                 msg: msgs::QueryChannelRange,
1497         },
1498         /// Request routing gossip messages from a peer for a list of channels identified by
1499         /// their short_channel_ids.
1500         SendShortIdsQuery {
1501                 /// The node_id of this message recipient
1502                 node_id: PublicKey,
1503                 /// The query_short_channel_ids which should be sent.
1504                 msg: msgs::QueryShortChannelIds,
1505         },
1506         /// Sends a reply to a channel range query. This may be one of several SendReplyChannelRange events
1507         /// emitted during processing of the query.
1508         SendReplyChannelRange {
1509                 /// The node_id of this message recipient
1510                 node_id: PublicKey,
1511                 /// The reply_channel_range which should be sent.
1512                 msg: msgs::ReplyChannelRange,
1513         },
1514         /// Sends a timestamp filter for inbound gossip. This should be sent on each new connection to
1515         /// enable receiving gossip messages from the peer.
1516         SendGossipTimestampFilter {
1517                 /// The node_id of this message recipient
1518                 node_id: PublicKey,
1519                 /// The gossip_timestamp_filter which should be sent.
1520                 msg: msgs::GossipTimestampFilter,
1521         },
1522 }
1523
1524 /// A trait indicating an object may generate message send events
1525 pub trait MessageSendEventsProvider {
1526         /// Gets the list of pending events which were generated by previous actions, clearing the list
1527         /// in the process.
1528         fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
1529 }
1530
1531 /// A trait indicating an object may generate onion messages to send
1532 pub trait OnionMessageProvider {
1533         /// Gets the next pending onion message for the peer with the given node id.
1534         fn next_onion_message_for_peer(&self, peer_node_id: PublicKey) -> Option<msgs::OnionMessage>;
1535 }
1536
1537 /// A trait indicating an object may generate events.
1538 ///
1539 /// Events are processed by passing an [`EventHandler`] to [`process_pending_events`].
1540 ///
1541 /// Implementations of this trait may also feature an async version of event handling, as shown with
1542 /// [`ChannelManager::process_pending_events_async`] and
1543 /// [`ChainMonitor::process_pending_events_async`].
1544 ///
1545 /// # Requirements
1546 ///
1547 /// When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
1548 /// event since the last invocation.
1549 ///
1550 /// In order to ensure no [`Event`]s are lost, implementors of this trait will persist [`Event`]s
1551 /// and replay any unhandled events on startup. An [`Event`] is considered handled when
1552 /// [`process_pending_events`] returns, thus handlers MUST fully handle [`Event`]s and persist any
1553 /// relevant changes to disk *before* returning.
1554 ///
1555 /// Further, because an application may crash between an [`Event`] being handled and the
1556 /// implementor of this trait being re-serialized, [`Event`] handling must be idempotent - in
1557 /// effect, [`Event`]s may be replayed.
1558 ///
1559 /// Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
1560 /// consult the provider's documentation on the implication of processing events and how a handler
1561 /// may safely use the provider (e.g., see [`ChannelManager::process_pending_events`] and
1562 /// [`ChainMonitor::process_pending_events`]).
1563 ///
1564 /// (C-not implementable) As there is likely no reason for a user to implement this trait on their
1565 /// own type(s).
1566 ///
1567 /// [`process_pending_events`]: Self::process_pending_events
1568 /// [`handle_event`]: EventHandler::handle_event
1569 /// [`ChannelManager::process_pending_events`]: crate::ln::channelmanager::ChannelManager#method.process_pending_events
1570 /// [`ChainMonitor::process_pending_events`]: crate::chain::chainmonitor::ChainMonitor#method.process_pending_events
1571 /// [`ChannelManager::process_pending_events_async`]: crate::ln::channelmanager::ChannelManager::process_pending_events_async
1572 /// [`ChainMonitor::process_pending_events_async`]: crate::chain::chainmonitor::ChainMonitor::process_pending_events_async
1573 pub trait EventsProvider {
1574         /// Processes any events generated since the last call using the given event handler.
1575         ///
1576         /// See the trait-level documentation for requirements.
1577         fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler;
1578 }
1579
1580 /// A trait implemented for objects handling events from [`EventsProvider`].
1581 ///
1582 /// An async variation also exists for implementations of [`EventsProvider`] that support async
1583 /// event handling. The async event handler should satisfy the generic bounds: `F:
1584 /// core::future::Future, H: Fn(Event) -> F`.
1585 pub trait EventHandler {
1586         /// Handles the given [`Event`].
1587         ///
1588         /// See [`EventsProvider`] for details that must be considered when implementing this method.
1589         fn handle_event(&self, event: Event);
1590 }
1591
1592 impl<F> EventHandler for F where F: Fn(Event) {
1593         fn handle_event(&self, event: Event) {
1594                 self(event)
1595         }
1596 }
1597
1598 impl<T: EventHandler> EventHandler for Arc<T> {
1599         fn handle_event(&self, event: Event) {
1600                 self.deref().handle_event(event)
1601         }
1602 }