_ 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 id returned by [`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 id returned by [`ChannelManager::send_payment`] and used with
 424                 /// [`ChannelManager::abandon_payment`].
 425                 ///
 426                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 427                 /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 428                 payment_id: PaymentId,
 429                 /// The hash that was given to [`ChannelManager::send_payment`].
 430                 ///
 431                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 432                 payment_hash: PaymentHash,
 433         },
 434         /// Indicates that a path for an outbound payment was successful.
 435         ///
 436         /// Always generated after [`Event::PaymentSent`] and thus useful for scoring channels. See
 437         /// [`Event::PaymentSent`] for obtaining the payment preimage.
 438         PaymentPathSuccessful {
 439                 /// The id returned by [`ChannelManager::send_payment`].
 440                 ///
 441                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 442                 payment_id: PaymentId,
 443                 /// The hash that was given to [`ChannelManager::send_payment`].
 444                 ///
 445                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 446                 payment_hash: Option<PaymentHash>,
 447                 /// The payment path that was successful.
 448                 ///
 449                 /// May contain a closed channel if the HTLC sent along the path was fulfilled on chain.
 450                 path: Vec<RouteHop>,
 451         },
 452         /// Indicates an outbound HTLC we sent failed, likely due to an intermediary node being unable to
 453         /// handle the HTLC.
 454         ///
 455         /// Note that this does *not* indicate that all paths for an MPP payment have failed, see
 456         /// [`Event::PaymentFailed`].
 457         ///
 458         /// See [`ChannelManager::abandon_payment`] for giving up on this payment before its retries have
 459         /// been exhausted.
 460         ///
 461         /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 462         PaymentPathFailed {
 463                 /// The id returned by [`ChannelManager::send_payment`] and used with
 464                 /// [`ChannelManager::abandon_payment`].
 465                 ///
 466                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 467                 /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 468                 payment_id: Option<PaymentId>,
 469                 /// The hash that was given to [`ChannelManager::send_payment`].
 470                 ///
 471                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 472                 payment_hash: PaymentHash,
 473                 /// Indicates the payment was rejected for some reason by the recipient. This implies that
 474                 /// the payment has failed, not just the route in question. If this is not set, the payment may
 475                 /// be retried via a different route.
 476                 payment_failed_permanently: bool,
 477                 /// Extra error details based on the failure type. May contain an update that needs to be
 478                 /// applied to the [`NetworkGraph`].
 479                 ///
 480                 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
 481                 failure: PathFailure,
 482                 /// The payment path that failed.
 483                 path: Vec<RouteHop>,
 484                 /// The channel responsible for the failed payment path.
 485                 ///
 486                 /// Note that for route hints or for the first hop in a path this may be an SCID alias and
 487                 /// may not refer to a channel in the public network graph. These aliases may also collide
 488                 /// with channels in the public network graph.
 489                 ///
 490                 /// If this is `Some`, then the corresponding channel should be avoided when the payment is
 491                 /// retried. May be `None` for older [`Event`] serializations.
 492                 short_channel_id: Option<u64>,
 493 #[cfg(test)]
 494                 error_code: Option<u16>,
 495 #[cfg(test)]
 496                 error_data: Option<Vec<u8>>,
 497         },
 498         /// Indicates that a probe payment we sent returned successful, i.e., only failed at the destination.
 499         ProbeSuccessful {
 500                 /// The id returned by [`ChannelManager::send_probe`].
 501                 ///
 502                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
 503                 payment_id: PaymentId,
 504                 /// The hash generated by [`ChannelManager::send_probe`].
 505                 ///
 506                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
 507                 payment_hash: PaymentHash,
 508                 /// The payment path that was successful.
 509                 path: Vec<RouteHop>,
 510         },
 511         /// Indicates that a probe payment we sent failed at an intermediary node on the path.
 512         ProbeFailed {
 513                 /// The id returned by [`ChannelManager::send_probe`].
 514                 ///
 515                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
 516                 payment_id: PaymentId,
 517                 /// The hash generated by [`ChannelManager::send_probe`].
 518                 ///
 519                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
 520                 payment_hash: PaymentHash,
 521                 /// The payment path that failed.
 522                 path: Vec<RouteHop>,
 523                 /// The channel responsible for the failed probe.
 524                 ///
 525                 /// Note that for route hints or for the first hop in a path this may be an SCID alias and
 526                 /// may not refer to a channel in the public network graph. These aliases may also collide
 527                 /// with channels in the public network graph.
 528                 short_channel_id: Option<u64>,
 529         },
 530         /// Used to indicate that [`ChannelManager::process_pending_htlc_forwards`] should be called at
 531         /// a time in the future.
 532         ///
 533         /// [`ChannelManager::process_pending_htlc_forwards`]: crate::ln::channelmanager::ChannelManager::process_pending_htlc_forwards
 534         PendingHTLCsForwardable {
 535                 /// The minimum amount of time that should be waited prior to calling
 536                 /// process_pending_htlc_forwards. To increase the effort required to correlate payments,
 537                 /// you should wait a random amount of time in roughly the range (now + time_forwardable,
 538                 /// now + 5*time_forwardable).
 539                 time_forwardable: Duration,
 540         },
 541         /// Used to indicate that we've intercepted an HTLC forward. This event will only be generated if
 542         /// you've encoded an intercept scid in the receiver's invoice route hints using
 543         /// [`ChannelManager::get_intercept_scid`] and have set [`UserConfig::accept_intercept_htlcs`].
 544         ///
 545         /// [`ChannelManager::forward_intercepted_htlc`] or
 546         /// [`ChannelManager::fail_intercepted_htlc`] MUST be called in response to this event. See
 547         /// their docs for more information.
 548         ///
 549         /// [`ChannelManager::get_intercept_scid`]: crate::ln::channelmanager::ChannelManager::get_intercept_scid
 550         /// [`UserConfig::accept_intercept_htlcs`]: crate::util::config::UserConfig::accept_intercept_htlcs
 551         /// [`ChannelManager::forward_intercepted_htlc`]: crate::ln::channelmanager::ChannelManager::forward_intercepted_htlc
 552         /// [`ChannelManager::fail_intercepted_htlc`]: crate::ln::channelmanager::ChannelManager::fail_intercepted_htlc
 553         HTLCIntercepted {
 554                 /// An id to help LDK identify which HTLC is being forwarded or failed.
 555                 intercept_id: InterceptId,
 556                 /// The fake scid that was programmed as the next hop's scid, generated using
 557                 /// [`ChannelManager::get_intercept_scid`].
 558                 ///
 559                 /// [`ChannelManager::get_intercept_scid`]: crate::ln::channelmanager::ChannelManager::get_intercept_scid
 560                 requested_next_hop_scid: u64,
 561                 /// The payment hash used for this HTLC.
 562                 payment_hash: PaymentHash,
 563                 /// How many msats were received on the inbound edge of this HTLC.
 564                 inbound_amount_msat: u64,
 565                 /// How many msats the payer intended to route to the next node. Depending on the reason you are
 566                 /// intercepting this payment, you might take a fee by forwarding less than this amount.
 567                 ///
 568                 /// Note that LDK will NOT check that expected fees were factored into this value. You MUST
 569                 /// check that whatever fee you want has been included here or subtract it as required. Further,
 570                 /// LDK will not stop you from forwarding more than you received.
 571                 expected_outbound_amount_msat: u64,
 572         },
 573         /// Used to indicate that an output which you should know how to spend was confirmed on chain
 574         /// and is now spendable.
 575         /// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
 576         /// counterparty spending them due to some kind of timeout. Thus, you need to store them
 577         /// somewhere and spend them when you create on-chain transactions.
 578         SpendableOutputs {
 579                 /// The outputs which you should store as spendable by you.
 580                 outputs: Vec<SpendableOutputDescriptor>,
 581         },
 582         /// This event is generated when a payment has been successfully forwarded through us and a
 583         /// forwarding fee earned.
 584         PaymentForwarded {
 585                 /// The incoming channel between the previous node and us. This is only `None` for events
 586                 /// generated or serialized by versions prior to 0.0.107.
 587                 prev_channel_id: Option<[u8; 32]>,
 588                 /// The outgoing channel between the next node and us. This is only `None` for events
 589                 /// generated or serialized by versions prior to 0.0.107.
 590                 next_channel_id: Option<[u8; 32]>,
 591                 /// The fee, in milli-satoshis, which was earned as a result of the payment.
 592                 ///
 593                 /// Note that if we force-closed the channel over which we forwarded an HTLC while the HTLC
 594                 /// was pending, the amount the next hop claimed will have been rounded down to the nearest
 595                 /// whole satoshi. Thus, the fee calculated here may be higher than expected as we still
 596                 /// claimed the full value in millisatoshis from the source. In this case,
 597                 /// `claim_from_onchain_tx` will be set.
 598                 ///
 599                 /// If the channel which sent us the payment has been force-closed, we will claim the funds
 600                 /// via an on-chain transaction. In that case we do not yet know the on-chain transaction
 601                 /// fees which we will spend and will instead set this to `None`. It is possible duplicate
 602                 /// `PaymentForwarded` events are generated for the same payment iff `fee_earned_msat` is
 603                 /// `None`.
 604                 fee_earned_msat: Option<u64>,
 605                 /// If this is `true`, the forwarded HTLC was claimed by our counterparty via an on-chain
 606                 /// transaction.
 607                 claim_from_onchain_tx: bool,
 608                 /// The final amount forwarded, in milli-satoshis, after the fee is deducted.
 609                 ///
 610                 /// The caveat described above the `fee_earned_msat` field applies here as well.
 611                 outbound_amount_forwarded_msat: Option<u64>,
 612         },
 613         /// Used to indicate that a channel with the given `channel_id` is being opened and pending
 614         /// confirmation on-chain.
 615         ///
 616         /// This event is emitted when the funding transaction has been signed and is broadcast to the
 617         /// network. For 0conf channels it will be immediately followed by the corresponding
 618         /// [`Event::ChannelReady`] event.
 619         ChannelPending {
 620                 /// The `channel_id` of the channel that is pending confirmation.
 621                 channel_id: [u8; 32],
 622                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
 623                 /// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
 624                 /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
 625                 /// `user_channel_id` will be randomized for an inbound channel.
 626                 ///
 627                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
 628                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 629                 /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
 630                 user_channel_id: u128,
 631                 /// The `temporary_channel_id` this channel used to be known by during channel establishment.
 632                 ///
 633                 /// Will be `None` for channels created prior to LDK version 0.0.115.
 634                 former_temporary_channel_id: Option<[u8; 32]>,
 635                 /// The `node_id` of the channel counterparty.
 636                 counterparty_node_id: PublicKey,
 637                 /// The outpoint of the channel's funding transaction.
 638                 funding_txo: OutPoint,
 639         },
 640         /// Used to indicate that a channel with the given `channel_id` is ready to
 641         /// be used. This event is emitted either when the funding transaction has been confirmed
 642         /// on-chain, or, in case of a 0conf channel, when both parties have confirmed the channel
 643         /// establishment.
 644         ChannelReady {
 645                 /// The `channel_id` of the channel that is ready.
 646                 channel_id: [u8; 32],
 647                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
 648                 /// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
 649                 /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
 650                 /// `user_channel_id` will be randomized for an inbound channel.
 651                 ///
 652                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
 653                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 654                 /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
 655                 user_channel_id: u128,
 656                 /// The `node_id` of the channel counterparty.
 657                 counterparty_node_id: PublicKey,
 658                 /// The features that this channel will operate with.
 659                 channel_type: ChannelTypeFeatures,
 660         },
 661         /// Used to indicate that a previously opened channel with the given `channel_id` is in the
 662         /// process of closure.
 663         ChannelClosed  {
 664                 /// The `channel_id` of the channel which has been closed. Note that on-chain transactions
 665                 /// resolving the channel are likely still awaiting confirmation.
 666                 channel_id: [u8; 32],
 667                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
 668                 /// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
 669                 /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
 670                 /// `user_channel_id` will be randomized for inbound channels.
 671                 /// This may be zero for inbound channels serialized prior to 0.0.113 and will always be
 672                 /// zero for objects serialized with LDK versions prior to 0.0.102.
 673                 ///
 674                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
 675                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 676                 /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
 677                 user_channel_id: u128,
 678                 /// The reason the channel was closed.
 679                 reason: ClosureReason
 680         },
 681         /// Used to indicate to the user that they can abandon the funding transaction and recycle the
 682         /// inputs for another purpose.
 683         DiscardFunding {
 684                 /// The channel_id of the channel which has been closed.
 685                 channel_id: [u8; 32],
 686                 /// The full transaction received from the user
 687                 transaction: Transaction
 688         },
 689         /// Indicates a request to open a new channel by a peer.
 690         ///
 691         /// To accept the request, call [`ChannelManager::accept_inbound_channel`]. To reject the
 692         /// request, call [`ChannelManager::force_close_without_broadcasting_txn`].
 693         ///
 694         /// The event is only triggered when a new open channel request is received and the
 695         /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true.
 696         ///
 697         /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 698         /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
 699         /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
 700         OpenChannelRequest {
 701                 /// The temporary channel ID of the channel requested to be opened.
 702                 ///
 703                 /// When responding to the request, the `temporary_channel_id` should be passed
 704                 /// back to the ChannelManager through [`ChannelManager::accept_inbound_channel`] to accept,
 705                 /// or through [`ChannelManager::force_close_without_broadcasting_txn`] to reject.
 706                 ///
 707                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 708                 /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
 709                 temporary_channel_id: [u8; 32],
 710                 /// The node_id of the counterparty requesting to open the channel.
 711                 ///
 712                 /// When responding to the request, the `counterparty_node_id` should be passed
 713                 /// back to the `ChannelManager` through [`ChannelManager::accept_inbound_channel`] to
 714                 /// accept the request, or through [`ChannelManager::force_close_without_broadcasting_txn`] to reject the
 715                 /// request.
 716                 ///
 717                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 718                 /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
 719                 counterparty_node_id: PublicKey,
 720                 /// The channel value of the requested channel.
 721                 funding_satoshis: u64,
 722                 /// Our starting balance in the channel if the request is accepted, in milli-satoshi.
 723                 push_msat: u64,
 724                 /// The features that this channel will operate with. If you reject the channel, a
 725                 /// well-behaved counterparty may automatically re-attempt the channel with a new set of
 726                 /// feature flags.
 727                 ///
 728                 /// Note that if [`ChannelTypeFeatures::supports_scid_privacy`] returns true on this type,
 729                 /// the resulting [`ChannelManager`] will not be readable by versions of LDK prior to
 730                 /// 0.0.106.
 731                 ///
 732                 /// Furthermore, note that if [`ChannelTypeFeatures::supports_zero_conf`] returns true on this type,
 733                 /// the resulting [`ChannelManager`] will not be readable by versions of LDK prior to
 734                 /// 0.0.107. Channels setting this type also need to get manually accepted via
 735                 /// [`crate::ln::channelmanager::ChannelManager::accept_inbound_channel_from_trusted_peer_0conf`],
 736                 /// or will be rejected otherwise.
 737                 ///
 738                 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 739                 channel_type: ChannelTypeFeatures,
 740         },
 741         /// Indicates that the HTLC was accepted, but could not be processed when or after attempting to
 742         /// forward it.
 743         ///
 744         /// Some scenarios where this event may be sent include:
 745         /// * Insufficient capacity in the outbound channel
 746         /// * While waiting to forward the HTLC, the channel it is meant to be forwarded through closes
 747         /// * When an unknown SCID is requested for forwarding a payment.
 748         /// * Expected MPP amount has already been reached
 749         /// * The HTLC has timed out
 750         ///
 751         /// This event, however, does not get generated if an HTLC fails to meet the forwarding
 752         /// requirements (i.e. insufficient fees paid, or a CLTV that is too soon).
 753         HTLCHandlingFailed {
 754                 /// The channel over which the HTLC was received.
 755                 prev_channel_id: [u8; 32],
 756                 /// Destination of the HTLC that failed to be processed.
 757                 failed_next_destination: HTLCDestination,
 758         },
 759         #[cfg(anchors)]
 760         /// Indicates that a transaction originating from LDK needs to have its fee bumped. This event
 761         /// requires confirmed external funds to be readily available to spend.
 762         ///
 763         /// LDK does not currently generate this event. It is limited to the scope of channels with
 764         /// anchor outputs, which will be introduced in a future release.
 765         BumpTransaction(BumpTransactionEvent),
 766 }
 767
 768 impl Writeable for Event {
 769         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 770                 match self {
 771                         &Event::FundingGenerationReady { .. } => {
 772                                 0u8.write(writer)?;
 773                                 // We never write out FundingGenerationReady events as, upon disconnection, peers
 774                                 // drop any channels which have not yet exchanged funding_signed.
 775                         },
 776                         &Event::PaymentClaimable { ref payment_hash, ref amount_msat, ref purpose, ref receiver_node_id, ref via_channel_id, ref via_user_channel_id } => {
 777                                 1u8.write(writer)?;
 778                                 let mut payment_secret = None;
 779                                 let payment_preimage;
 780                                 match &purpose {
 781                                         PaymentPurpose::InvoicePayment { payment_preimage: preimage, payment_secret: secret } => {
 782                                                 payment_secret = Some(secret);
 783                                                 payment_preimage = *preimage;
 784                                         },
 785                                         PaymentPurpose::SpontaneousPayment(preimage) => {
 786                                                 payment_preimage = Some(*preimage);
 787                                         }
 788                                 }
 789                                 write_tlv_fields!(writer, {
 790                                         (0, payment_hash, required),
 791                                         (1, receiver_node_id, option),
 792                                         (2, payment_secret, option),
 793                                         (3, via_channel_id, option),
 794                                         (4, amount_msat, required),
 795                                         (5, via_user_channel_id, option),
 796                                         (6, 0u64, required), // user_payment_id required for compatibility with 0.0.103 and earlier
 797                                         (8, payment_preimage, option),
 798                                 });
 799                         },
 800                         &Event::PaymentSent { ref payment_id, ref payment_preimage, ref payment_hash, ref fee_paid_msat } => {
 801                                 2u8.write(writer)?;
 802                                 write_tlv_fields!(writer, {
 803                                         (0, payment_preimage, required),
 804                                         (1, payment_hash, required),
 805                                         (3, payment_id, option),
 806                                         (5, fee_paid_msat, option),
 807                                 });
 808                         },
 809                         &Event::PaymentPathFailed {
 810                                 ref payment_id, ref payment_hash, ref payment_failed_permanently, ref failure,
 811                                 ref path, ref short_channel_id,
 812                                 #[cfg(test)]
 813                                 ref error_code,
 814                                 #[cfg(test)]
 815                                 ref error_data,
 816                         } => {
 817                                 3u8.write(writer)?;
 818                                 #[cfg(test)]
 819                                 error_code.write(writer)?;
 820                                 #[cfg(test)]
 821                                 error_data.write(writer)?;
 822                                 write_tlv_fields!(writer, {
 823                                         (0, payment_hash, required),
 824                                         (1, None::<NetworkUpdate>, option), // network_update in LDK versions prior to 0.0.114
 825                                         (2, payment_failed_permanently, required),
 826                                         (3, false, required), // all_paths_failed in LDK versions prior to 0.0.114
 827                                         (5, *path, vec_type),
 828                                         (7, short_channel_id, option),
 829                                         (9, None::<RouteParameters>, option), // retry in LDK versions prior to 0.0.115
 830                                         (11, payment_id, option),
 831                                         (13, failure, required),
 832                                 });
 833                         },
 834                         &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
 835                                 4u8.write(writer)?;
 836                                 // Note that we now ignore these on the read end as we'll re-generate them in
 837                                 // ChannelManager, we write them here only for backwards compatibility.
 838                         },
 839                         &Event::SpendableOutputs { ref outputs } => {
 840                                 5u8.write(writer)?;
 841                                 write_tlv_fields!(writer, {
 842                                         (0, WithoutLength(outputs), required),
 843                                 });
 844                         },
 845                         &Event::HTLCIntercepted { requested_next_hop_scid, payment_hash, inbound_amount_msat, expected_outbound_amount_msat, intercept_id } => {
 846                                 6u8.write(writer)?;
 847                                 let intercept_scid = InterceptNextHop::FakeScid { requested_next_hop_scid };
 848                                 write_tlv_fields!(writer, {
 849                                         (0, intercept_id, required),
 850                                         (2, intercept_scid, required),
 851                                         (4, payment_hash, required),
 852                                         (6, inbound_amount_msat, required),
 853                                         (8, expected_outbound_amount_msat, required),
 854                                 });
 855                         }
 856                         &Event::PaymentForwarded {
 857                                 fee_earned_msat, prev_channel_id, claim_from_onchain_tx,
 858                                 next_channel_id, outbound_amount_forwarded_msat
 859                         } => {
 860                                 7u8.write(writer)?;
 861                                 write_tlv_fields!(writer, {
 862                                         (0, fee_earned_msat, option),
 863                                         (1, prev_channel_id, option),
 864                                         (2, claim_from_onchain_tx, required),
 865                                         (3, next_channel_id, option),
 866                                         (5, outbound_amount_forwarded_msat, option),
 867                                 });
 868                         },
 869                         &Event::ChannelClosed { ref channel_id, ref user_channel_id, ref reason } => {
 870                                 9u8.write(writer)?;
 871                                 // `user_channel_id` used to be a single u64 value. In order to remain backwards
 872                                 // compatible with versions prior to 0.0.113, the u128 is serialized as two
 873                                 // separate u64 values.
 874                                 let user_channel_id_low = *user_channel_id as u64;
 875                                 let user_channel_id_high = (*user_channel_id >> 64) as u64;
 876                                 write_tlv_fields!(writer, {
 877                                         (0, channel_id, required),
 878                                         (1, user_channel_id_low, required),
 879                                         (2, reason, required),
 880                                         (3, user_channel_id_high, required),
 881                                 });
 882                         },
 883                         &Event::DiscardFunding { ref channel_id, ref transaction } => {
 884                                 11u8.write(writer)?;
 885                                 write_tlv_fields!(writer, {
 886                                         (0, channel_id, required),
 887                                         (2, transaction, required)
 888                                 })
 889                         },
 890                         &Event::PaymentPathSuccessful { ref payment_id, ref payment_hash, ref path } => {
 891                                 13u8.write(writer)?;
 892                                 write_tlv_fields!(writer, {
 893                                         (0, payment_id, required),
 894                                         (2, payment_hash, option),
 895                                         (4, *path, vec_type)
 896                                 })
 897                         },
 898                         &Event::PaymentFailed { ref payment_id, ref payment_hash } => {
 899                                 15u8.write(writer)?;
 900                                 write_tlv_fields!(writer, {
 901                                         (0, payment_id, required),
 902                                         (2, payment_hash, required),
 903                                 })
 904                         },
 905                         &Event::OpenChannelRequest { .. } => {
 906                                 17u8.write(writer)?;
 907                                 // We never write the OpenChannelRequest events as, upon disconnection, peers
 908                                 // drop any channels which have not yet exchanged funding_signed.
 909                         },
 910                         &Event::PaymentClaimed { ref payment_hash, ref amount_msat, ref purpose, ref receiver_node_id } => {
 911                                 19u8.write(writer)?;
 912                                 write_tlv_fields!(writer, {
 913                                         (0, payment_hash, required),
 914                                         (1, receiver_node_id, option),
 915                                         (2, purpose, required),
 916                                         (4, amount_msat, required),
 917                                 });
 918                         },
 919                         &Event::ProbeSuccessful { ref payment_id, ref payment_hash, ref path } => {
 920                                 21u8.write(writer)?;
 921                                 write_tlv_fields!(writer, {
 922                                         (0, payment_id, required),
 923                                         (2, payment_hash, required),
 924                                         (4, *path, vec_type)
 925                                 })
 926                         },
 927                         &Event::ProbeFailed { ref payment_id, ref payment_hash, ref path, ref short_channel_id } => {
 928                                 23u8.write(writer)?;
 929                                 write_tlv_fields!(writer, {
 930                                         (0, payment_id, required),
 931                                         (2, payment_hash, required),
 932                                         (4, *path, vec_type),
 933                                         (6, short_channel_id, option),
 934                                 })
 935                         },
 936                         &Event::HTLCHandlingFailed { ref prev_channel_id, ref failed_next_destination } => {
 937                                 25u8.write(writer)?;
 938                                 write_tlv_fields!(writer, {
 939                                         (0, prev_channel_id, required),
 940                                         (2, failed_next_destination, required),
 941                                 })
 942                         },
 943                         #[cfg(anchors)]
 944                         &Event::BumpTransaction(ref event)=> {
 945                                 27u8.write(writer)?;
 946                                 match event {
 947                                         // We never write the ChannelClose|HTLCResolution events as they'll be replayed
 948                                         // upon restarting anyway if they remain unresolved.
 949                                         BumpTransactionEvent::ChannelClose { .. } => {}
 950                                         BumpTransactionEvent::HTLCResolution { .. } => {}
 951                                 }
 952                                 write_tlv_fields!(writer, {}); // Write a length field for forwards compat
 953                         }
 954                         &Event::ChannelReady { ref channel_id, ref user_channel_id, ref counterparty_node_id, ref channel_type } => {
 955                                 29u8.write(writer)?;
 956                                 write_tlv_fields!(writer, {
 957                                         (0, channel_id, required),
 958                                         (2, user_channel_id, required),
 959                                         (4, counterparty_node_id, required),
 960                                         (6, channel_type, required),
 961                                 });
 962                         },
 963                         &Event::ChannelPending { ref channel_id, ref user_channel_id, ref former_temporary_channel_id, ref counterparty_node_id, ref funding_txo } => {
 964                                 31u8.write(writer)?;
 965                                 write_tlv_fields!(writer, {
 966                                         (0, channel_id, required),
 967                                         (2, user_channel_id, required),
 968                                         (4, former_temporary_channel_id, required),
 969                                         (6, counterparty_node_id, required),
 970                                         (8, funding_txo, required),
 971                                 });
 972                         },
 973                         // Note that, going forward, all new events must only write data inside of
 974                         // `write_tlv_fields`. Versions 0.0.101+ will ignore odd-numbered events that write
 975                         // data via `write_tlv_fields`.
 976                 }
 977                 Ok(())
 978         }
 979 }
 980 impl MaybeReadable for Event {
 981         fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
 982                 match Readable::read(reader)? {
 983                         // Note that we do not write a length-prefixed TLV for FundingGenerationReady events,
 984                         // unlike all other events, thus we return immediately here.
 985                         0u8 => Ok(None),
 986                         1u8 => {
 987                                 let f = || {
 988                                         let mut payment_hash = PaymentHash([0; 32]);
 989                                         let mut payment_preimage = None;
 990                                         let mut payment_secret = None;
 991                                         let mut amount_msat = 0;
 992                                         let mut receiver_node_id = None;
 993                                         let mut _user_payment_id = None::<u64>; // For compatibility with 0.0.103 and earlier
 994                                         let mut via_channel_id = None;
 995                                         let mut via_user_channel_id = None;
 996                                         read_tlv_fields!(reader, {
 997                                                 (0, payment_hash, required),
 998                                                 (1, receiver_node_id, option),
 999                                                 (2, payment_secret, option),
1000                                                 (3, via_channel_id, option),
1001                                                 (4, amount_msat, required),
1002                                                 (5, via_user_channel_id, option),
1003                                                 (6, _user_payment_id, option),
1004                                                 (8, payment_preimage, option),
1005                                         });
1006                                         let purpose = match payment_secret {
1007                                                 Some(secret) => PaymentPurpose::InvoicePayment {
1008                                                         payment_preimage,
1009                                                         payment_secret: secret
1010                                                 },
1011                                                 None if payment_preimage.is_some() => PaymentPurpose::SpontaneousPayment(payment_preimage.unwrap()),
1012                                                 None => return Err(msgs::DecodeError::InvalidValue),
1013                                         };
1014                                         Ok(Some(Event::PaymentClaimable {
1015                                                 receiver_node_id,
1016                                                 payment_hash,
1017                                                 amount_msat,
1018                                                 purpose,
1019                                                 via_channel_id,
1020                                                 via_user_channel_id,
1021                                         }))
1022                                 };
1023                                 f()
1024                         },
1025                         2u8 => {
1026                                 let f = || {
1027                                         let mut payment_preimage = PaymentPreimage([0; 32]);
1028                                         let mut payment_hash = None;
1029                                         let mut payment_id = None;
1030                                         let mut fee_paid_msat = None;
1031                                         read_tlv_fields!(reader, {
1032                                                 (0, payment_preimage, required),
1033                                                 (1, payment_hash, option),
1034                                                 (3, payment_id, option),
1035                                                 (5, fee_paid_msat, option),
1036                                         });
1037                                         if payment_hash.is_none() {
1038                                                 payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()));
1039                                         }
1040                                         Ok(Some(Event::PaymentSent {
1041                                                 payment_id,
1042                                                 payment_preimage,
1043                                                 payment_hash: payment_hash.unwrap(),
1044                                                 fee_paid_msat,
1045                                         }))
1046                                 };
1047                                 f()
1048                         },
1049                         3u8 => {
1050                                 let f = || {
1051                                         #[cfg(test)]
1052                                         let error_code = Readable::read(reader)?;
1053                                         #[cfg(test)]
1054                                         let error_data = Readable::read(reader)?;
1055                                         let mut payment_hash = PaymentHash([0; 32]);
1056                                         let mut payment_failed_permanently = false;
1057                                         let mut network_update = None;
1058                                         let mut path: Option<Vec<RouteHop>> = Some(vec![]);
1059                                         let mut short_channel_id = None;
1060                                         let mut payment_id = None;
1061                                         let mut failure_opt = None;
1062                                         read_tlv_fields!(reader, {
1063                                                 (0, payment_hash, required),
1064                                                 (1, network_update, upgradable_option),
1065                                                 (2, payment_failed_permanently, required),
1066                                                 (5, path, vec_type),
1067                                                 (7, short_channel_id, option),
1068                                                 (11, payment_id, option),
1069                                                 (13, failure_opt, upgradable_option),
1070                                         });
1071                                         let failure = failure_opt.unwrap_or_else(|| PathFailure::OnPath { network_update });
1072                                         Ok(Some(Event::PaymentPathFailed {
1073                                                 payment_id,
1074                                                 payment_hash,
1075                                                 payment_failed_permanently,
1076                                                 failure,
1077                                                 path: path.unwrap(),
1078                                                 short_channel_id,
1079                                                 #[cfg(test)]
1080                                                 error_code,
1081                                                 #[cfg(test)]
1082                                                 error_data,
1083                                         }))
1084                                 };
1085                                 f()
1086                         },
1087                         4u8 => Ok(None),
1088                         5u8 => {
1089                                 let f = || {
1090                                         let mut outputs = WithoutLength(Vec::new());
1091                                         read_tlv_fields!(reader, {
1092                                                 (0, outputs, required),
1093                                         });
1094                                         Ok(Some(Event::SpendableOutputs { outputs: outputs.0 }))
1095                                 };
1096                                 f()
1097                         },
1098                         6u8 => {
1099                                 let mut payment_hash = PaymentHash([0; 32]);
1100                                 let mut intercept_id = InterceptId([0; 32]);
1101                                 let mut requested_next_hop_scid = InterceptNextHop::FakeScid { requested_next_hop_scid: 0 };
1102                                 let mut inbound_amount_msat = 0;
1103                                 let mut expected_outbound_amount_msat = 0;
1104                                 read_tlv_fields!(reader, {
1105                                         (0, intercept_id, required),
1106                                         (2, requested_next_hop_scid, required),
1107                                         (4, payment_hash, required),
1108                                         (6, inbound_amount_msat, required),
1109                                         (8, expected_outbound_amount_msat, required),
1110                                 });
1111                                 let next_scid = match requested_next_hop_scid {
1112                                         InterceptNextHop::FakeScid { requested_next_hop_scid: scid } => scid
1113                                 };
1114                                 Ok(Some(Event::HTLCIntercepted {
1115                                         payment_hash,
1116                                         requested_next_hop_scid: next_scid,
1117                                         inbound_amount_msat,
1118                                         expected_outbound_amount_msat,
1119                                         intercept_id,
1120                                 }))
1121                         },
1122                         7u8 => {
1123                                 let f = || {
1124                                         let mut fee_earned_msat = None;
1125                                         let mut prev_channel_id = None;
1126                                         let mut claim_from_onchain_tx = false;
1127                                         let mut next_channel_id = None;
1128                                         let mut outbound_amount_forwarded_msat = None;
1129                                         read_tlv_fields!(reader, {
1130                                                 (0, fee_earned_msat, option),
1131                                                 (1, prev_channel_id, option),
1132                                                 (2, claim_from_onchain_tx, required),
1133                                                 (3, next_channel_id, option),
1134                                                 (5, outbound_amount_forwarded_msat, option),
1135                                         });
1136                                         Ok(Some(Event::PaymentForwarded {
1137                                                 fee_earned_msat, prev_channel_id, claim_from_onchain_tx, next_channel_id,
1138                                                 outbound_amount_forwarded_msat
1139                                         }))
1140                                 };
1141                                 f()
1142                         },
1143                         9u8 => {
1144                                 let f = || {
1145                                         let mut channel_id = [0; 32];
1146                                         let mut reason = UpgradableRequired(None);
1147                                         let mut user_channel_id_low_opt: Option<u64> = None;
1148                                         let mut user_channel_id_high_opt: Option<u64> = None;
1149                                         read_tlv_fields!(reader, {
1150                                                 (0, channel_id, required),
1151                                                 (1, user_channel_id_low_opt, option),
1152                                                 (2, reason, upgradable_required),
1153                                                 (3, user_channel_id_high_opt, option),
1154                                         });
1155
1156                                         // `user_channel_id` used to be a single u64 value. In order to remain
1157                                         // backwards compatible with versions prior to 0.0.113, the u128 is serialized
1158                                         // as two separate u64 values.
1159                                         let user_channel_id = (user_channel_id_low_opt.unwrap_or(0) as u128) +
1160                                                 ((user_channel_id_high_opt.unwrap_or(0) as u128) << 64);
1161
1162                                         Ok(Some(Event::ChannelClosed { channel_id, user_channel_id, reason: _init_tlv_based_struct_field!(reason, upgradable_required) }))
1163                                 };
1164                                 f()
1165                         },
1166                         11u8 => {
1167                                 let f = || {
1168                                         let mut channel_id = [0; 32];
1169                                         let mut transaction = Transaction{ version: 2, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
1170                                         read_tlv_fields!(reader, {
1171                                                 (0, channel_id, required),
1172                                                 (2, transaction, required),
1173                                         });
1174                                         Ok(Some(Event::DiscardFunding { channel_id, transaction } ))
1175                                 };
1176                                 f()
1177                         },
1178                         13u8 => {
1179                                 let f = || {
1180                                         let mut payment_id = PaymentId([0; 32]);
1181                                         let mut payment_hash = None;
1182                                         let mut path: Option<Vec<RouteHop>> = Some(vec![]);
1183                                         read_tlv_fields!(reader, {
1184                                                 (0, payment_id, required),
1185                                                 (2, payment_hash, option),
1186                                                 (4, path, vec_type),
1187                                         });
1188                                         Ok(Some(Event::PaymentPathSuccessful {
1189                                                 payment_id,
1190                                                 payment_hash,
1191                                                 path: path.unwrap(),
1192                                         }))
1193                                 };
1194                                 f()
1195                         },
1196                         15u8 => {
1197                                 let f = || {
1198                                         let mut payment_hash = PaymentHash([0; 32]);
1199                                         let mut payment_id = PaymentId([0; 32]);
1200                                         read_tlv_fields!(reader, {
1201                                                 (0, payment_id, required),
1202                                                 (2, payment_hash, required),
1203                                         });
1204                                         Ok(Some(Event::PaymentFailed {
1205                                                 payment_id,
1206                                                 payment_hash,
1207                                         }))
1208                                 };
1209                                 f()
1210                         },
1211                         17u8 => {
1212                                 // Value 17 is used for `Event::OpenChannelRequest`.
1213                                 Ok(None)
1214                         },
1215                         19u8 => {
1216                                 let f = || {
1217                                         let mut payment_hash = PaymentHash([0; 32]);
1218                                         let mut purpose = UpgradableRequired(None);
1219                                         let mut amount_msat = 0;
1220                                         let mut receiver_node_id = None;
1221                                         read_tlv_fields!(reader, {
1222                                                 (0, payment_hash, required),
1223                                                 (1, receiver_node_id, option),
1224                                                 (2, purpose, upgradable_required),
1225                                                 (4, amount_msat, required),
1226                                         });
1227                                         Ok(Some(Event::PaymentClaimed {
1228                                                 receiver_node_id,
1229                                                 payment_hash,
1230                                                 purpose: _init_tlv_based_struct_field!(purpose, upgradable_required),
1231                                                 amount_msat,
1232                                         }))
1233                                 };
1234                                 f()
1235                         },
1236                         21u8 => {
1237                                 let f = || {
1238                                         let mut payment_id = PaymentId([0; 32]);
1239                                         let mut payment_hash = PaymentHash([0; 32]);
1240                                         let mut path: Option<Vec<RouteHop>> = Some(vec![]);
1241                                         read_tlv_fields!(reader, {
1242                                                 (0, payment_id, required),
1243                                                 (2, payment_hash, required),
1244                                                 (4, path, vec_type),
1245                                         });
1246                                         Ok(Some(Event::ProbeSuccessful {
1247                                                 payment_id,
1248                                                 payment_hash,
1249                                                 path: path.unwrap(),
1250                                         }))
1251                                 };
1252                                 f()
1253                         },
1254                         23u8 => {
1255                                 let f = || {
1256                                         let mut payment_id = PaymentId([0; 32]);
1257                                         let mut payment_hash = PaymentHash([0; 32]);
1258                                         let mut path: Option<Vec<RouteHop>> = Some(vec![]);
1259                                         let mut short_channel_id = None;
1260                                         read_tlv_fields!(reader, {
1261                                                 (0, payment_id, required),
1262                                                 (2, payment_hash, required),
1263                                                 (4, path, vec_type),
1264                                                 (6, short_channel_id, option),
1265                                         });
1266                                         Ok(Some(Event::ProbeFailed {
1267                                                 payment_id,
1268                                                 payment_hash,
1269                                                 path: path.unwrap(),
1270                                                 short_channel_id,
1271                                         }))
1272                                 };
1273                                 f()
1274                         },
1275                         25u8 => {
1276                                 let f = || {
1277                                         let mut prev_channel_id = [0; 32];
1278                                         let mut failed_next_destination_opt = UpgradableRequired(None);
1279                                         read_tlv_fields!(reader, {
1280                                                 (0, prev_channel_id, required),
1281                                                 (2, failed_next_destination_opt, upgradable_required),
1282                                         });
1283                                         Ok(Some(Event::HTLCHandlingFailed {
1284                                                 prev_channel_id,
1285                                                 failed_next_destination: _init_tlv_based_struct_field!(failed_next_destination_opt, upgradable_required),
1286                                         }))
1287                                 };
1288                                 f()
1289                         },
1290                         27u8 => Ok(None),
1291                         29u8 => {
1292                                 let f = || {
1293                                         let mut channel_id = [0; 32];
1294                                         let mut user_channel_id: u128 = 0;
1295                                         let mut counterparty_node_id = RequiredWrapper(None);
1296                                         let mut channel_type = RequiredWrapper(None);
1297                                         read_tlv_fields!(reader, {
1298                                                 (0, channel_id, required),
1299                                                 (2, user_channel_id, required),
1300                                                 (4, counterparty_node_id, required),
1301                                                 (6, channel_type, required),
1302                                         });
1303
1304                                         Ok(Some(Event::ChannelReady {
1305                                                 channel_id,
1306                                                 user_channel_id,
1307                                                 counterparty_node_id: counterparty_node_id.0.unwrap(),
1308                                                 channel_type: channel_type.0.unwrap()
1309                                         }))
1310                                 };
1311                                 f()
1312                         },
1313                         31u8 => {
1314                                 let f = || {
1315                                         let mut channel_id = [0; 32];
1316                                         let mut user_channel_id: u128 = 0;
1317                                         let mut former_temporary_channel_id = None;
1318                                         let mut counterparty_node_id = RequiredWrapper(None);
1319                                         let mut funding_txo = RequiredWrapper(None);
1320                                         read_tlv_fields!(reader, {
1321                                                 (0, channel_id, required),
1322                                                 (2, user_channel_id, required),
1323                                                 (4, former_temporary_channel_id, required),
1324                                                 (6, counterparty_node_id, required),
1325                                                 (8, funding_txo, required),
1326                                         });
1327
1328                                         Ok(Some(Event::ChannelPending {
1329                                                 channel_id,
1330                                                 user_channel_id,
1331                                                 former_temporary_channel_id,
1332                                                 counterparty_node_id: counterparty_node_id.0.unwrap(),
1333                                                 funding_txo: funding_txo.0.unwrap()
1334                                         }))
1335                                 };
1336                                 f()
1337                         },
1338                         // Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue.
1339                         // Version 0.0.100 failed to properly ignore odd types, possibly resulting in corrupt
1340                         // reads.
1341                         x if x % 2 == 1 => {
1342                                 // If the event is of unknown type, assume it was written with `write_tlv_fields`,
1343                                 // which prefixes the whole thing with a length BigSize. Because the event is
1344                                 // odd-type unknown, we should treat it as `Ok(None)` even if it has some TLV
1345                                 // fields that are even. Thus, we avoid using `read_tlv_fields` and simply read
1346                                 // exactly the number of bytes specified, ignoring them entirely.
1347                                 let tlv_len: BigSize = Readable::read(reader)?;
1348                                 FixedLengthReader::new(reader, tlv_len.0)
1349                                         .eat_remaining().map_err(|_| msgs::DecodeError::ShortRead)?;
1350                                 Ok(None)
1351                         },
1352                         _ => Err(msgs::DecodeError::InvalidValue)
1353                 }
1354         }
1355 }
1356
1357 /// An event generated by ChannelManager which indicates a message should be sent to a peer (or
1358 /// broadcast to most peers).
1359 /// These events are handled by PeerManager::process_events if you are using a PeerManager.
1360 #[derive(Clone, Debug)]
1361 pub enum MessageSendEvent {
1362         /// Used to indicate that we've accepted a channel open and should send the accept_channel
1363         /// message provided to the given peer.
1364         SendAcceptChannel {
1365                 /// The node_id of the node which should receive this message
1366                 node_id: PublicKey,
1367                 /// The message which should be sent.
1368                 msg: msgs::AcceptChannel,
1369         },
1370         /// Used to indicate that we've initiated a channel open and should send the open_channel
1371         /// message provided to the given peer.
1372         SendOpenChannel {
1373                 /// The node_id of the node which should receive this message
1374                 node_id: PublicKey,
1375                 /// The message which should be sent.
1376                 msg: msgs::OpenChannel,
1377         },
1378         /// Used to indicate that a funding_created message should be sent to the peer with the given node_id.
1379         SendFundingCreated {
1380                 /// The node_id of the node which should receive this message
1381                 node_id: PublicKey,
1382                 /// The message which should be sent.
1383                 msg: msgs::FundingCreated,
1384         },
1385         /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id.
1386         SendFundingSigned {
1387                 /// The node_id of the node which should receive this message
1388                 node_id: PublicKey,
1389                 /// The message which should be sent.
1390                 msg: msgs::FundingSigned,
1391         },
1392         /// Used to indicate that a channel_ready message should be sent to the peer with the given node_id.
1393         SendChannelReady {
1394                 /// The node_id of the node which should receive these message(s)
1395                 node_id: PublicKey,
1396                 /// The channel_ready message which should be sent.
1397                 msg: msgs::ChannelReady,
1398         },
1399         /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
1400         SendAnnouncementSignatures {
1401                 /// The node_id of the node which should receive these message(s)
1402                 node_id: PublicKey,
1403                 /// The announcement_signatures message which should be sent.
1404                 msg: msgs::AnnouncementSignatures,
1405         },
1406         /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed
1407         /// message should be sent to the peer with the given node_id.
1408         UpdateHTLCs {
1409                 /// The node_id of the node which should receive these message(s)
1410                 node_id: PublicKey,
1411                 /// The update messages which should be sent. ALL messages in the struct should be sent!
1412                 updates: msgs::CommitmentUpdate,
1413         },
1414         /// Used to indicate that a revoke_and_ack message should be sent to the peer with the given node_id.
1415         SendRevokeAndACK {
1416                 /// The node_id of the node which should receive this message
1417                 node_id: PublicKey,
1418                 /// The message which should be sent.
1419                 msg: msgs::RevokeAndACK,
1420         },
1421         /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id.
1422         SendClosingSigned {
1423                 /// The node_id of the node which should receive this message
1424                 node_id: PublicKey,
1425                 /// The message which should be sent.
1426                 msg: msgs::ClosingSigned,
1427         },
1428         /// Used to indicate that a shutdown message should be sent to the peer with the given node_id.
1429         SendShutdown {
1430                 /// The node_id of the node which should receive this message
1431                 node_id: PublicKey,
1432                 /// The message which should be sent.
1433                 msg: msgs::Shutdown,
1434         },
1435         /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id.
1436         SendChannelReestablish {
1437                 /// The node_id of the node which should receive this message
1438                 node_id: PublicKey,
1439                 /// The message which should be sent.
1440                 msg: msgs::ChannelReestablish,
1441         },
1442         /// Used to send a channel_announcement and channel_update to a specific peer, likely on
1443         /// initial connection to ensure our peers know about our channels.
1444         SendChannelAnnouncement {
1445                 /// The node_id of the node which should receive this message
1446                 node_id: PublicKey,
1447                 /// The channel_announcement which should be sent.
1448                 msg: msgs::ChannelAnnouncement,
1449                 /// The followup channel_update which should be sent.
1450                 update_msg: msgs::ChannelUpdate,
1451         },
1452         /// Used to indicate that a channel_announcement and channel_update should be broadcast to all
1453         /// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
1454         ///
1455         /// Note that after doing so, you very likely (unless you did so very recently) want to
1456         /// broadcast a node_announcement (e.g. via [`PeerManager::broadcast_node_announcement`]). This
1457         /// ensures that any nodes which see our channel_announcement also have a relevant
1458         /// node_announcement, including relevant feature flags which may be important for routing
1459         /// through or to us.
1460         ///
1461         /// [`PeerManager::broadcast_node_announcement`]: crate::ln::peer_handler::PeerManager::broadcast_node_announcement
1462         BroadcastChannelAnnouncement {
1463                 /// The channel_announcement which should be sent.
1464                 msg: msgs::ChannelAnnouncement,
1465                 /// The followup channel_update which should be sent.
1466                 update_msg: Option<msgs::ChannelUpdate>,
1467         },
1468         /// Used to indicate that a channel_update should be broadcast to all peers.
1469         BroadcastChannelUpdate {
1470                 /// The channel_update which should be sent.
1471                 msg: msgs::ChannelUpdate,
1472         },
1473         /// Used to indicate that a node_announcement should be broadcast to all peers.
1474         BroadcastNodeAnnouncement {
1475                 /// The node_announcement which should be sent.
1476                 msg: msgs::NodeAnnouncement,
1477         },
1478         /// Used to indicate that a channel_update should be sent to a single peer.
1479         /// In contrast to [`Self::BroadcastChannelUpdate`], this is used when the channel is a
1480         /// private channel and we shouldn't be informing all of our peers of channel parameters.
1481         SendChannelUpdate {
1482                 /// The node_id of the node which should receive this message
1483                 node_id: PublicKey,
1484                 /// The channel_update which should be sent.
1485                 msg: msgs::ChannelUpdate,
1486         },
1487         /// Broadcast an error downstream to be handled
1488         HandleError {
1489                 /// The node_id of the node which should receive this message
1490                 node_id: PublicKey,
1491                 /// The action which should be taken.
1492                 action: msgs::ErrorAction
1493         },
1494         /// Query a peer for channels with funding transaction UTXOs in a block range.
1495         SendChannelRangeQuery {
1496                 /// The node_id of this message recipient
1497                 node_id: PublicKey,
1498                 /// The query_channel_range which should be sent.
1499                 msg: msgs::QueryChannelRange,
1500         },
1501         /// Request routing gossip messages from a peer for a list of channels identified by
1502         /// their short_channel_ids.
1503         SendShortIdsQuery {
1504                 /// The node_id of this message recipient
1505                 node_id: PublicKey,
1506                 /// The query_short_channel_ids which should be sent.
1507                 msg: msgs::QueryShortChannelIds,
1508         },
1509         /// Sends a reply to a channel range query. This may be one of several SendReplyChannelRange events
1510         /// emitted during processing of the query.
1511         SendReplyChannelRange {
1512                 /// The node_id of this message recipient
1513                 node_id: PublicKey,
1514                 /// The reply_channel_range which should be sent.
1515                 msg: msgs::ReplyChannelRange,
1516         },
1517         /// Sends a timestamp filter for inbound gossip. This should be sent on each new connection to
1518         /// enable receiving gossip messages from the peer.
1519         SendGossipTimestampFilter {
1520                 /// The node_id of this message recipient
1521                 node_id: PublicKey,
1522                 /// The gossip_timestamp_filter which should be sent.
1523                 msg: msgs::GossipTimestampFilter,
1524         },
1525 }
1526
1527 /// A trait indicating an object may generate message send events
1528 pub trait MessageSendEventsProvider {
1529         /// Gets the list of pending events which were generated by previous actions, clearing the list
1530         /// in the process.
1531         fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
1532 }
1533
1534 /// A trait indicating an object may generate onion messages to send
1535 pub trait OnionMessageProvider {
1536         /// Gets the next pending onion message for the peer with the given node id.
1537         fn next_onion_message_for_peer(&self, peer_node_id: PublicKey) -> Option<msgs::OnionMessage>;
1538 }
1539
1540 /// A trait indicating an object may generate events.
1541 ///
1542 /// Events are processed by passing an [`EventHandler`] to [`process_pending_events`].
1543 ///
1544 /// Implementations of this trait may also feature an async version of event handling, as shown with
1545 /// [`ChannelManager::process_pending_events_async`] and
1546 /// [`ChainMonitor::process_pending_events_async`].
1547 ///
1548 /// # Requirements
1549 ///
1550 /// When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
1551 /// event since the last invocation.
1552 ///
1553 /// In order to ensure no [`Event`]s are lost, implementors of this trait will persist [`Event`]s
1554 /// and replay any unhandled events on startup. An [`Event`] is considered handled when
1555 /// [`process_pending_events`] returns, thus handlers MUST fully handle [`Event`]s and persist any
1556 /// relevant changes to disk *before* returning.
1557 ///
1558 /// Further, because an application may crash between an [`Event`] being handled and the
1559 /// implementor of this trait being re-serialized, [`Event`] handling must be idempotent - in
1560 /// effect, [`Event`]s may be replayed.
1561 ///
1562 /// Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
1563 /// consult the provider's documentation on the implication of processing events and how a handler
1564 /// may safely use the provider (e.g., see [`ChannelManager::process_pending_events`] and
1565 /// [`ChainMonitor::process_pending_events`]).
1566 ///
1567 /// (C-not implementable) As there is likely no reason for a user to implement this trait on their
1568 /// own type(s).
1569 ///
1570 /// [`process_pending_events`]: Self::process_pending_events
1571 /// [`handle_event`]: EventHandler::handle_event
1572 /// [`ChannelManager::process_pending_events`]: crate::ln::channelmanager::ChannelManager#method.process_pending_events
1573 /// [`ChainMonitor::process_pending_events`]: crate::chain::chainmonitor::ChainMonitor#method.process_pending_events
1574 /// [`ChannelManager::process_pending_events_async`]: crate::ln::channelmanager::ChannelManager::process_pending_events_async
1575 /// [`ChainMonitor::process_pending_events_async`]: crate::chain::chainmonitor::ChainMonitor::process_pending_events_async
1576 pub trait EventsProvider {
1577         /// Processes any events generated since the last call using the given event handler.
1578         ///
1579         /// See the trait-level documentation for requirements.
1580         fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler;
1581 }
1582
1583 /// A trait implemented for objects handling events from [`EventsProvider`].
1584 ///
1585 /// An async variation also exists for implementations of [`EventsProvider`] that support async
1586 /// event handling. The async event handler should satisfy the generic bounds: `F:
1587 /// core::future::Future, H: Fn(Event) -> F`.
1588 pub trait EventHandler {
1589         /// Handles the given [`Event`].
1590         ///
1591         /// See [`EventsProvider`] for details that must be considered when implementing this method.
1592         fn handle_event(&self, event: Event);
1593 }
1594
1595 impl<F> EventHandler for F where F: Fn(Event) {
1596         fn handle_event(&self, event: Event) {
1597                 self(event)
1598         }
1599 }
1600
1601 impl<T: EventHandler> EventHandler for Arc<T> {
1602         fn handle_event(&self, event: Event) {
1603                 self.deref().handle_event(event)
1604         }
1605 }