_ 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 pub mod bump_transaction;
  18
  19 pub use bump_transaction::BumpTransactionEvent;
  20
  21 use crate::sign::SpendableOutputDescriptor;
  22 use crate::ln::channelmanager::{InterceptId, PaymentId, RecipientOnionFields};
  23 use crate::ln::channel::FUNDING_CONF_DEADLINE_BLOCKS;
  24 use crate::ln::features::ChannelTypeFeatures;
  25 use crate::ln::msgs;
  26 use crate::ln::{PaymentPreimage, PaymentHash, PaymentSecret};
  27 use crate::routing::gossip::NetworkUpdate;
  28 use crate::util::errors::APIError;
  29 use crate::util::ser::{BigSize, FixedLengthReader, Writeable, Writer, MaybeReadable, Readable, RequiredWrapper, UpgradableRequired, WithoutLength};
  30 use crate::util::string::UntrustedString;
  31 use crate::routing::router::{BlindedTail, Path, RouteHop, RouteParameters};
  32
  33 use bitcoin::{PackedLockTime, Transaction, OutPoint};
  34 use bitcoin::blockdata::script::Script;
  35 use bitcoin::hashes::Hash;
  36 use bitcoin::hashes::sha256::Hash as Sha256;
  37 use bitcoin::secp256k1::PublicKey;
  38 use crate::io;
  39 use crate::prelude::*;
  40 use core::time::Duration;
  41 use core::ops::Deref;
  42 use crate::sync::Arc;
  43
  44 /// Some information provided on receipt of payment depends on whether the payment received is a
  45 /// spontaneous payment or a "conventional" lightning payment that's paying an invoice.
  46 #[derive(Clone, Debug, PartialEq, Eq)]
  47 pub enum PaymentPurpose {
  48         /// Information for receiving a payment that we generated an invoice for.
  49         InvoicePayment {
  50                 /// The preimage to the payment_hash, if the payment hash (and secret) were fetched via
  51                 /// [`ChannelManager::create_inbound_payment`]. If provided, this can be handed directly to
  52                 /// [`ChannelManager::claim_funds`].
  53                 ///
  54                 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
  55                 /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
  56                 payment_preimage: Option<PaymentPreimage>,
  57                 /// The "payment secret". This authenticates the sender to the recipient, preventing a
  58                 /// number of deanonymization attacks during the routing process.
  59                 /// It is provided here for your reference, however its accuracy is enforced directly by
  60                 /// [`ChannelManager`] using the values you previously provided to
  61                 /// [`ChannelManager::create_inbound_payment`] or
  62                 /// [`ChannelManager::create_inbound_payment_for_hash`].
  63                 ///
  64                 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
  65                 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
  66                 /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
  67                 payment_secret: PaymentSecret,
  68         },
  69         /// Because this is a spontaneous payment, the payer generated their own preimage rather than us
  70         /// (the payee) providing a preimage.
  71         SpontaneousPayment(PaymentPreimage),
  72 }
  73
  74 impl_writeable_tlv_based_enum!(PaymentPurpose,
  75         (0, InvoicePayment) => {
  76                 (0, payment_preimage, option),
  77                 (2, payment_secret, required),
  78         };
  79         (2, SpontaneousPayment)
  80 );
  81
  82 /// When the payment path failure took place and extra details about it. [`PathFailure::OnPath`] may
  83 /// contain a [`NetworkUpdate`] that needs to be applied to the [`NetworkGraph`].
  84 ///
  85 /// [`NetworkUpdate`]: crate::routing::gossip::NetworkUpdate
  86 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
  87 #[derive(Clone, Debug, Eq, PartialEq)]
  88 pub enum PathFailure {
  89         /// We failed to initially send the payment and no HTLC was committed to. Contains the relevant
  90         /// error.
  91         InitialSend {
  92                 /// The error surfaced from initial send.
  93                 err: APIError,
  94         },
  95         /// A hop on the path failed to forward our payment.
  96         OnPath {
  97                 /// If present, this [`NetworkUpdate`] should be applied to the [`NetworkGraph`] so that routing
  98                 /// decisions can take into account the update.
  99                 ///
 100                 /// [`NetworkUpdate`]: crate::routing::gossip::NetworkUpdate
 101                 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
 102                 network_update: Option<NetworkUpdate>,
 103         },
 104 }
 105
 106 impl_writeable_tlv_based_enum_upgradable!(PathFailure,
 107         (0, OnPath) => {
 108                 (0, network_update, upgradable_option),
 109         },
 110         (2, InitialSend) => {
 111                 (0, err, upgradable_required),
 112         },
 113 );
 114
 115 #[derive(Clone, Debug, PartialEq, Eq)]
 116 /// The reason the channel was closed. See individual variants more details.
 117 pub enum ClosureReason {
 118         /// Closure generated from receiving a peer error message.
 119         ///
 120         /// Our counterparty may have broadcasted their latest commitment state, and we have
 121         /// as well.
 122         CounterpartyForceClosed {
 123                 /// The error which the peer sent us.
 124                 ///
 125                 /// Be careful about printing the peer_msg, a well-crafted message could exploit
 126                 /// a security vulnerability in the terminal emulator or the logging subsystem.
 127                 /// To be safe, use `Display` on `UntrustedString`
 128                 ///
 129                 /// [`UntrustedString`]: crate::util::string::UntrustedString
 130                 peer_msg: UntrustedString,
 131         },
 132         /// Closure generated from [`ChannelManager::force_close_channel`], called by the user.
 133         ///
 134         /// [`ChannelManager::force_close_channel`]: crate::ln::channelmanager::ChannelManager::force_close_channel.
 135         HolderForceClosed,
 136         /// The channel was closed after negotiating a cooperative close and we've now broadcasted
 137         /// the cooperative close transaction. Note the shutdown may have been initiated by us.
 138         //TODO: split between CounterpartyInitiated/LocallyInitiated
 139         CooperativeClosure,
 140         /// A commitment transaction was confirmed on chain, closing the channel. Most likely this
 141         /// commitment transaction came from our counterparty, but it may also have come from
 142         /// a copy of our own `ChannelMonitor`.
 143         CommitmentTxConfirmed,
 144         /// The funding transaction failed to confirm in a timely manner on an inbound channel.
 145         FundingTimedOut,
 146         /// Closure generated from processing an event, likely a HTLC forward/relay/reception.
 147         ProcessingError {
 148                 /// A developer-readable error message which we generated.
 149                 err: String,
 150         },
 151         /// The peer disconnected prior to funding completing. In this case the spec mandates that we
 152         /// forget the channel entirely - we can attempt again if the peer reconnects.
 153         ///
 154         /// This includes cases where we restarted prior to funding completion, including prior to the
 155         /// initial [`ChannelMonitor`] persistence completing.
 156         ///
 157         /// In LDK versions prior to 0.0.107 this could also occur if we were unable to connect to the
 158         /// peer because of mutual incompatibility between us and our channel counterparty.
 159         ///
 160         /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
 161         DisconnectedPeer,
 162         /// Closure generated from `ChannelManager::read` if the [`ChannelMonitor`] is newer than
 163         /// the [`ChannelManager`] deserialized.
 164         ///
 165         /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
 166         /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 167         OutdatedChannelManager
 168 }
 169
 170 impl core::fmt::Display for ClosureReason {
 171         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
 172                 f.write_str("Channel closed because ")?;
 173                 match self {
 174                         ClosureReason::CounterpartyForceClosed { peer_msg } => {
 175                                 f.write_fmt(format_args!("counterparty force-closed with message: {}", peer_msg))
 176                         },
 177                         ClosureReason::HolderForceClosed => f.write_str("user manually force-closed the channel"),
 178                         ClosureReason::CooperativeClosure => f.write_str("the channel was cooperatively closed"),
 179                         ClosureReason::CommitmentTxConfirmed => f.write_str("commitment or closing transaction was confirmed on chain."),
 180                         ClosureReason::FundingTimedOut => write!(f, "funding transaction failed to confirm within {} blocks", FUNDING_CONF_DEADLINE_BLOCKS),
 181                         ClosureReason::ProcessingError { err } => {
 182                                 f.write_str("of an exception: ")?;
 183                                 f.write_str(&err)
 184                         },
 185                         ClosureReason::DisconnectedPeer => f.write_str("the peer disconnected prior to the channel being funded"),
 186                         ClosureReason::OutdatedChannelManager => f.write_str("the ChannelManager read from disk was stale compared to ChannelMonitor(s)"),
 187                 }
 188         }
 189 }
 190
 191 impl_writeable_tlv_based_enum_upgradable!(ClosureReason,
 192         (0, CounterpartyForceClosed) => { (1, peer_msg, required) },
 193         (1, FundingTimedOut) => {},
 194         (2, HolderForceClosed) => {},
 195         (6, CommitmentTxConfirmed) => {},
 196         (4, CooperativeClosure) => {},
 197         (8, ProcessingError) => { (1, err, required) },
 198         (10, DisconnectedPeer) => {},
 199         (12, OutdatedChannelManager) => {},
 200 );
 201
 202 /// Intended destination of a failed HTLC as indicated in [`Event::HTLCHandlingFailed`].
 203 #[derive(Clone, Debug, PartialEq, Eq)]
 204 pub enum HTLCDestination {
 205         /// We tried forwarding to a channel but failed to do so. An example of such an instance is when
 206         /// there is insufficient capacity in our outbound channel.
 207         NextHopChannel {
 208                 /// The `node_id` of the next node. For backwards compatibility, this field is
 209                 /// marked as optional, versions prior to 0.0.110 may not always be able to provide
 210                 /// counterparty node information.
 211                 node_id: Option<PublicKey>,
 212                 /// The outgoing `channel_id` between us and the next node.
 213                 channel_id: [u8; 32],
 214         },
 215         /// Scenario where we are unsure of the next node to forward the HTLC to.
 216         UnknownNextHop {
 217                 /// Short channel id we are requesting to forward an HTLC to.
 218                 requested_forward_scid: u64,
 219         },
 220         /// We couldn't forward to the outgoing scid. An example would be attempting to send a duplicate
 221         /// intercept HTLC.
 222         InvalidForward {
 223                 /// Short channel id we are requesting to forward an HTLC to.
 224                 requested_forward_scid: u64
 225         },
 226         /// Failure scenario where an HTLC may have been forwarded to be intended for us,
 227         /// but is invalid for some reason, so we reject it.
 228         ///
 229         /// Some of the reasons may include:
 230         /// * HTLC Timeouts
 231         /// * Excess HTLCs for a payment that we have already fully received, over-paying for the
 232         ///   payment,
 233         /// * The counterparty node modified the HTLC in transit,
 234         /// * A probing attack where an intermediary node is trying to detect if we are the ultimate
 235         ///   recipient for a payment.
 236         FailedPayment {
 237                 /// The payment hash of the payment we attempted to process.
 238                 payment_hash: PaymentHash
 239         },
 240 }
 241
 242 impl_writeable_tlv_based_enum_upgradable!(HTLCDestination,
 243         (0, NextHopChannel) => {
 244                 (0, node_id, required),
 245                 (2, channel_id, required),
 246         },
 247         (1, InvalidForward) => {
 248                 (0, requested_forward_scid, required),
 249         },
 250         (2, UnknownNextHop) => {
 251                 (0, requested_forward_scid, required),
 252         },
 253         (4, FailedPayment) => {
 254                 (0, payment_hash, required),
 255         },
 256 );
 257
 258 /// Will be used in [`Event::HTLCIntercepted`] to identify the next hop in the HTLC's path.
 259 /// Currently only used in serialization for the sake of maintaining compatibility. More variants
 260 /// will be added for general-purpose HTLC forward intercepts as well as trampoline forward
 261 /// intercepts in upcoming work.
 262 enum InterceptNextHop {
 263         FakeScid {
 264                 requested_next_hop_scid: u64,
 265         },
 266 }
 267
 268 impl_writeable_tlv_based_enum!(InterceptNextHop,
 269         (0, FakeScid) => {
 270                 (0, requested_next_hop_scid, required),
 271         };
 272 );
 273
 274 /// The reason the payment failed. Used in [`Event::PaymentFailed`].
 275 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 276 pub enum PaymentFailureReason {
 277         /// The intended recipient rejected our payment.
 278         RecipientRejected,
 279         /// The user chose to abandon this payment by calling [`ChannelManager::abandon_payment`].
 280         ///
 281         /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 282         UserAbandoned,
 283         /// We exhausted all of our retry attempts while trying to send the payment, or we
 284         /// exhausted the [`Retry::Timeout`] if the user set one. If at any point a retry
 285         /// attempt failed while being forwarded along the path, an [`Event::PaymentPathFailed`] will
 286         /// have come before this.
 287         ///
 288         /// [`Retry::Timeout`]: crate::ln::channelmanager::Retry::Timeout
 289         RetriesExhausted,
 290         /// The payment expired while retrying, based on the provided
 291         /// [`PaymentParameters::expiry_time`].
 292         ///
 293         /// [`PaymentParameters::expiry_time`]: crate::routing::router::PaymentParameters::expiry_time
 294         PaymentExpired,
 295         /// We failed to find a route while retrying the payment.
 296         RouteNotFound,
 297         /// This error should generally never happen. This likely means that there is a problem with
 298         /// your router.
 299         UnexpectedError,
 300 }
 301
 302 impl_writeable_tlv_based_enum!(PaymentFailureReason,
 303         (0, RecipientRejected) => {},
 304         (2, UserAbandoned) => {},
 305         (4, RetriesExhausted) => {},
 306         (6, PaymentExpired) => {},
 307         (8, RouteNotFound) => {},
 308         (10, UnexpectedError) => {}, ;
 309 );
 310
 311 /// An Event which you should probably take some action in response to.
 312 ///
 313 /// Note that while Writeable and Readable are implemented for Event, you probably shouldn't use
 314 /// them directly as they don't round-trip exactly (for example FundingGenerationReady is never
 315 /// written as it makes no sense to respond to it after reconnecting to peers).
 316 #[derive(Clone, Debug, PartialEq, Eq)]
 317 pub enum Event {
 318         /// Used to indicate that the client should generate a funding transaction with the given
 319         /// parameters and then call [`ChannelManager::funding_transaction_generated`].
 320         /// Generated in [`ChannelManager`] message handling.
 321         /// Note that *all inputs* in the funding transaction must spend SegWit outputs or your
 322         /// counterparty can steal your funds!
 323         ///
 324         /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 325         /// [`ChannelManager::funding_transaction_generated`]: crate::ln::channelmanager::ChannelManager::funding_transaction_generated
 326         FundingGenerationReady {
 327                 /// The random channel_id we picked which you'll need to pass into
 328                 /// [`ChannelManager::funding_transaction_generated`].
 329                 ///
 330                 /// [`ChannelManager::funding_transaction_generated`]: crate::ln::channelmanager::ChannelManager::funding_transaction_generated
 331                 temporary_channel_id: [u8; 32],
 332                 /// The counterparty's node_id, which you'll need to pass back into
 333                 /// [`ChannelManager::funding_transaction_generated`].
 334                 ///
 335                 /// [`ChannelManager::funding_transaction_generated`]: crate::ln::channelmanager::ChannelManager::funding_transaction_generated
 336                 counterparty_node_id: PublicKey,
 337                 /// The value, in satoshis, that the output should have.
 338                 channel_value_satoshis: u64,
 339                 /// The script which should be used in the transaction output.
 340                 output_script: Script,
 341                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`], or a
 342                 /// random value for an inbound channel. This may be zero for objects serialized with LDK
 343                 /// versions prior to 0.0.113.
 344                 ///
 345                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
 346                 user_channel_id: u128,
 347         },
 348         /// Indicates that we've been offered a payment and it needs to be claimed via calling
 349         /// [`ChannelManager::claim_funds`] with the preimage given in [`PaymentPurpose`].
 350         ///
 351         /// Note that if the preimage is not known, you should call
 352         /// [`ChannelManager::fail_htlc_backwards`] or [`ChannelManager::fail_htlc_backwards_with_reason`]
 353         /// to free up resources for this HTLC and avoid network congestion.
 354         /// If you fail to call either [`ChannelManager::claim_funds`], [`ChannelManager::fail_htlc_backwards`],
 355         /// or [`ChannelManager::fail_htlc_backwards_with_reason`] within the HTLC's timeout, the HTLC will be
 356         /// automatically failed.
 357         ///
 358         /// # Note
 359         /// LDK will not stop an inbound payment from being paid multiple times, so multiple
 360         /// `PaymentClaimable` events may be generated for the same payment. In such a case it is
 361         /// polite (and required in the lightning specification) to fail the payment the second time
 362         /// and give the sender their money back rather than accepting double payment.
 363         ///
 364         /// # Note
 365         /// This event used to be called `PaymentReceived` in LDK versions 0.0.112 and earlier.
 366         ///
 367         /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
 368         /// [`ChannelManager::fail_htlc_backwards`]: crate::ln::channelmanager::ChannelManager::fail_htlc_backwards
 369         /// [`ChannelManager::fail_htlc_backwards_with_reason`]: crate::ln::channelmanager::ChannelManager::fail_htlc_backwards_with_reason
 370         PaymentClaimable {
 371                 /// The node that will receive the payment after it has been claimed.
 372                 /// This is useful to identify payments received via [phantom nodes].
 373                 /// This field will always be filled in when the event was generated by LDK versions
 374                 /// 0.0.113 and above.
 375                 ///
 376                 /// [phantom nodes]: crate::sign::PhantomKeysManager
 377                 receiver_node_id: Option<PublicKey>,
 378                 /// The hash for which the preimage should be handed to the ChannelManager. Note that LDK will
 379                 /// not stop you from registering duplicate payment hashes for inbound payments.
 380                 payment_hash: PaymentHash,
 381                 /// The fields in the onion which were received with each HTLC. Only fields which were
 382                 /// identical in each HTLC involved in the payment will be included here.
 383                 ///
 384                 /// Payments received on LDK versions prior to 0.0.115 will have this field unset.
 385                 onion_fields: Option<RecipientOnionFields>,
 386                 /// The value, in thousandths of a satoshi, that this payment is claimable for. May be greater
 387                 /// than the invoice amount.
 388                 ///
 389                 /// May be less than the invoice amount if [`ChannelConfig::accept_underpaying_htlcs`] is set
 390                 /// and the previous hop took an extra fee.
 391                 ///
 392                 /// # Note
 393                 /// If [`ChannelConfig::accept_underpaying_htlcs`] is set and you claim without verifying this
 394                 /// field, you may lose money!
 395                 ///
 396                 /// [`ChannelConfig::accept_underpaying_htlcs`]: crate::util::config::ChannelConfig::accept_underpaying_htlcs
 397                 amount_msat: u64,
 398                 /// The value, in thousands of a satoshi, that was skimmed off of this payment as an extra fee
 399                 /// taken by our channel counterparty.
 400                 ///
 401                 /// Will always be 0 unless [`ChannelConfig::accept_underpaying_htlcs`] is set.
 402                 ///
 403                 /// [`ChannelConfig::accept_underpaying_htlcs`]: crate::util::config::ChannelConfig::accept_underpaying_htlcs
 404                 counterparty_skimmed_fee_msat: u64,
 405                 /// Information for claiming this received payment, based on whether the purpose of the
 406                 /// payment is to pay an invoice or to send a spontaneous payment.
 407                 purpose: PaymentPurpose,
 408                 /// The `channel_id` indicating over which channel we received the payment.
 409                 via_channel_id: Option<[u8; 32]>,
 410                 /// The `user_channel_id` indicating over which channel we received the payment.
 411                 via_user_channel_id: Option<u128>,
 412                 /// The block height at which this payment will be failed back and will no longer be
 413                 /// eligible for claiming.
 414                 ///
 415                 /// Prior to this height, a call to [`ChannelManager::claim_funds`] is guaranteed to
 416                 /// succeed, however you should wait for [`Event::PaymentClaimed`] to be sure.
 417                 ///
 418                 /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
 419                 claim_deadline: Option<u32>,
 420         },
 421         /// Indicates a payment has been claimed and we've received money!
 422         ///
 423         /// This most likely occurs when [`ChannelManager::claim_funds`] has been called in response
 424         /// to an [`Event::PaymentClaimable`]. However, if we previously crashed during a
 425         /// [`ChannelManager::claim_funds`] call you may see this event without a corresponding
 426         /// [`Event::PaymentClaimable`] event.
 427         ///
 428         /// # Note
 429         /// LDK will not stop an inbound payment from being paid multiple times, so multiple
 430         /// `PaymentClaimable` events may be generated for the same payment. If you then call
 431         /// [`ChannelManager::claim_funds`] twice for the same [`Event::PaymentClaimable`] you may get
 432         /// multiple `PaymentClaimed` events.
 433         ///
 434         /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
 435         PaymentClaimed {
 436                 /// The node that received the payment.
 437                 /// This is useful to identify payments which were received via [phantom nodes].
 438                 /// This field will always be filled in when the event was generated by LDK versions
 439                 /// 0.0.113 and above.
 440                 ///
 441                 /// [phantom nodes]: crate::sign::PhantomKeysManager
 442                 receiver_node_id: Option<PublicKey>,
 443                 /// The payment hash of the claimed payment. Note that LDK will not stop you from
 444                 /// registering duplicate payment hashes for inbound payments.
 445                 payment_hash: PaymentHash,
 446                 /// The value, in thousandths of a satoshi, that this payment is for. May be greater than the
 447                 /// invoice amount.
 448                 amount_msat: u64,
 449                 /// The purpose of the claimed payment, i.e. whether the payment was for an invoice or a
 450                 /// spontaneous payment.
 451                 purpose: PaymentPurpose,
 452         },
 453         /// Indicates an outbound payment we made succeeded (i.e. it made it all the way to its target
 454         /// and we got back the payment preimage for it).
 455         ///
 456         /// Note for MPP payments: in rare cases, this event may be preceded by a `PaymentPathFailed`
 457         /// event. In this situation, you SHOULD treat this payment as having succeeded.
 458         PaymentSent {
 459                 /// The `payment_id` passed to [`ChannelManager::send_payment`].
 460                 ///
 461                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 462                 payment_id: Option<PaymentId>,
 463                 /// The preimage to the hash given to ChannelManager::send_payment.
 464                 /// Note that this serves as a payment receipt, if you wish to have such a thing, you must
 465                 /// store it somehow!
 466                 payment_preimage: PaymentPreimage,
 467                 /// The hash that was given to [`ChannelManager::send_payment`].
 468                 ///
 469                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 470                 payment_hash: PaymentHash,
 471                 /// The total fee which was spent at intermediate hops in this payment, across all paths.
 472                 ///
 473                 /// Note that, like [`Route::get_total_fees`] this does *not* include any potential
 474                 /// overpayment to the recipient node.
 475                 ///
 476                 /// If the recipient or an intermediate node misbehaves and gives us free money, this may
 477                 /// overstate the amount paid, though this is unlikely.
 478                 ///
 479                 /// [`Route::get_total_fees`]: crate::routing::router::Route::get_total_fees
 480                 fee_paid_msat: Option<u64>,
 481         },
 482         /// Indicates an outbound payment failed. Individual [`Event::PaymentPathFailed`] events
 483         /// provide failure information for each path attempt in the payment, including retries.
 484         ///
 485         /// This event is provided once there are no further pending HTLCs for the payment and the
 486         /// payment is no longer retryable, due either to the [`Retry`] provided or
 487         /// [`ChannelManager::abandon_payment`] having been called for the corresponding payment.
 488         ///
 489         /// [`Retry`]: crate::ln::channelmanager::Retry
 490         /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 491         PaymentFailed {
 492                 /// The `payment_id` passed to [`ChannelManager::send_payment`].
 493                 ///
 494                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 495                 payment_id: PaymentId,
 496                 /// The hash that was given to [`ChannelManager::send_payment`].
 497                 ///
 498                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 499                 payment_hash: PaymentHash,
 500                 /// The reason the payment failed. This is only `None` for events generated or serialized
 501                 /// by versions prior to 0.0.115.
 502                 reason: Option<PaymentFailureReason>,
 503         },
 504         /// Indicates that a path for an outbound payment was successful.
 505         ///
 506         /// Always generated after [`Event::PaymentSent`] and thus useful for scoring channels. See
 507         /// [`Event::PaymentSent`] for obtaining the payment preimage.
 508         PaymentPathSuccessful {
 509                 /// The `payment_id` passed to [`ChannelManager::send_payment`].
 510                 ///
 511                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 512                 payment_id: PaymentId,
 513                 /// The hash that was given to [`ChannelManager::send_payment`].
 514                 ///
 515                 /// This will be `Some` for all payments which completed on LDK 0.0.104 or later.
 516                 ///
 517                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 518                 payment_hash: Option<PaymentHash>,
 519                 /// The payment path that was successful.
 520                 ///
 521                 /// May contain a closed channel if the HTLC sent along the path was fulfilled on chain.
 522                 path: Path,
 523         },
 524         /// Indicates an outbound HTLC we sent failed, likely due to an intermediary node being unable to
 525         /// handle the HTLC.
 526         ///
 527         /// Note that this does *not* indicate that all paths for an MPP payment have failed, see
 528         /// [`Event::PaymentFailed`].
 529         ///
 530         /// See [`ChannelManager::abandon_payment`] for giving up on this payment before its retries have
 531         /// been exhausted.
 532         ///
 533         /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 534         PaymentPathFailed {
 535                 /// The `payment_id` passed to [`ChannelManager::send_payment`].
 536                 ///
 537                 /// This will be `Some` for all payment paths which failed on LDK 0.0.103 or later.
 538                 ///
 539                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 540                 /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 541                 payment_id: Option<PaymentId>,
 542                 /// The hash that was given to [`ChannelManager::send_payment`].
 543                 ///
 544                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 545                 payment_hash: PaymentHash,
 546                 /// Indicates the payment was rejected for some reason by the recipient. This implies that
 547                 /// the payment has failed, not just the route in question. If this is not set, the payment may
 548                 /// be retried via a different route.
 549                 payment_failed_permanently: bool,
 550                 /// Extra error details based on the failure type. May contain an update that needs to be
 551                 /// applied to the [`NetworkGraph`].
 552                 ///
 553                 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
 554                 failure: PathFailure,
 555                 /// The payment path that failed.
 556                 path: Path,
 557                 /// The channel responsible for the failed payment path.
 558                 ///
 559                 /// Note that for route hints or for the first hop in a path this may be an SCID alias and
 560                 /// may not refer to a channel in the public network graph. These aliases may also collide
 561                 /// with channels in the public network graph.
 562                 ///
 563                 /// If this is `Some`, then the corresponding channel should be avoided when the payment is
 564                 /// retried. May be `None` for older [`Event`] serializations.
 565                 short_channel_id: Option<u64>,
 566 #[cfg(test)]
 567                 error_code: Option<u16>,
 568 #[cfg(test)]
 569                 error_data: Option<Vec<u8>>,
 570         },
 571         /// Indicates that a probe payment we sent returned successful, i.e., only failed at the destination.
 572         ProbeSuccessful {
 573                 /// The id returned by [`ChannelManager::send_probe`].
 574                 ///
 575                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
 576                 payment_id: PaymentId,
 577                 /// The hash generated by [`ChannelManager::send_probe`].
 578                 ///
 579                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
 580                 payment_hash: PaymentHash,
 581                 /// The payment path that was successful.
 582                 path: Path,
 583         },
 584         /// Indicates that a probe payment we sent failed at an intermediary node on the path.
 585         ProbeFailed {
 586                 /// The id returned by [`ChannelManager::send_probe`].
 587                 ///
 588                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
 589                 payment_id: PaymentId,
 590                 /// The hash generated by [`ChannelManager::send_probe`].
 591                 ///
 592                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
 593                 payment_hash: PaymentHash,
 594                 /// The payment path that failed.
 595                 path: Path,
 596                 /// The channel responsible for the failed probe.
 597                 ///
 598                 /// Note that for route hints or for the first hop in a path this may be an SCID alias and
 599                 /// may not refer to a channel in the public network graph. These aliases may also collide
 600                 /// with channels in the public network graph.
 601                 short_channel_id: Option<u64>,
 602         },
 603         /// Used to indicate that [`ChannelManager::process_pending_htlc_forwards`] should be called at
 604         /// a time in the future.
 605         ///
 606         /// [`ChannelManager::process_pending_htlc_forwards`]: crate::ln::channelmanager::ChannelManager::process_pending_htlc_forwards
 607         PendingHTLCsForwardable {
 608                 /// The minimum amount of time that should be waited prior to calling
 609                 /// process_pending_htlc_forwards. To increase the effort required to correlate payments,
 610                 /// you should wait a random amount of time in roughly the range (now + time_forwardable,
 611                 /// now + 5*time_forwardable).
 612                 time_forwardable: Duration,
 613         },
 614         /// Used to indicate that we've intercepted an HTLC forward. This event will only be generated if
 615         /// you've encoded an intercept scid in the receiver's invoice route hints using
 616         /// [`ChannelManager::get_intercept_scid`] and have set [`UserConfig::accept_intercept_htlcs`].
 617         ///
 618         /// [`ChannelManager::forward_intercepted_htlc`] or
 619         /// [`ChannelManager::fail_intercepted_htlc`] MUST be called in response to this event. See
 620         /// their docs for more information.
 621         ///
 622         /// [`ChannelManager::get_intercept_scid`]: crate::ln::channelmanager::ChannelManager::get_intercept_scid
 623         /// [`UserConfig::accept_intercept_htlcs`]: crate::util::config::UserConfig::accept_intercept_htlcs
 624         /// [`ChannelManager::forward_intercepted_htlc`]: crate::ln::channelmanager::ChannelManager::forward_intercepted_htlc
 625         /// [`ChannelManager::fail_intercepted_htlc`]: crate::ln::channelmanager::ChannelManager::fail_intercepted_htlc
 626         HTLCIntercepted {
 627                 /// An id to help LDK identify which HTLC is being forwarded or failed.
 628                 intercept_id: InterceptId,
 629                 /// The fake scid that was programmed as the next hop's scid, generated using
 630                 /// [`ChannelManager::get_intercept_scid`].
 631                 ///
 632                 /// [`ChannelManager::get_intercept_scid`]: crate::ln::channelmanager::ChannelManager::get_intercept_scid
 633                 requested_next_hop_scid: u64,
 634                 /// The payment hash used for this HTLC.
 635                 payment_hash: PaymentHash,
 636                 /// How many msats were received on the inbound edge of this HTLC.
 637                 inbound_amount_msat: u64,
 638                 /// How many msats the payer intended to route to the next node. Depending on the reason you are
 639                 /// intercepting this payment, you might take a fee by forwarding less than this amount.
 640                 /// Forwarding less than this amount may break compatibility with LDK versions prior to 0.0.116.
 641                 ///
 642                 /// Note that LDK will NOT check that expected fees were factored into this value. You MUST
 643                 /// check that whatever fee you want has been included here or subtract it as required. Further,
 644                 /// LDK will not stop you from forwarding more than you received.
 645                 expected_outbound_amount_msat: u64,
 646         },
 647         /// Used to indicate that an output which you should know how to spend was confirmed on chain
 648         /// and is now spendable.
 649         /// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
 650         /// counterparty spending them due to some kind of timeout. Thus, you need to store them
 651         /// somewhere and spend them when you create on-chain transactions.
 652         SpendableOutputs {
 653                 /// The outputs which you should store as spendable by you.
 654                 outputs: Vec<SpendableOutputDescriptor>,
 655         },
 656         /// This event is generated when a payment has been successfully forwarded through us and a
 657         /// forwarding fee earned.
 658         PaymentForwarded {
 659                 /// The incoming channel between the previous node and us. This is only `None` for events
 660                 /// generated or serialized by versions prior to 0.0.107.
 661                 prev_channel_id: Option<[u8; 32]>,
 662                 /// The outgoing channel between the next node and us. This is only `None` for events
 663                 /// generated or serialized by versions prior to 0.0.107.
 664                 next_channel_id: Option<[u8; 32]>,
 665                 /// The fee, in milli-satoshis, which was earned as a result of the payment.
 666                 ///
 667                 /// Note that if we force-closed the channel over which we forwarded an HTLC while the HTLC
 668                 /// was pending, the amount the next hop claimed will have been rounded down to the nearest
 669                 /// whole satoshi. Thus, the fee calculated here may be higher than expected as we still
 670                 /// claimed the full value in millisatoshis from the source. In this case,
 671                 /// `claim_from_onchain_tx` will be set.
 672                 ///
 673                 /// If the channel which sent us the payment has been force-closed, we will claim the funds
 674                 /// via an on-chain transaction. In that case we do not yet know the on-chain transaction
 675                 /// fees which we will spend and will instead set this to `None`. It is possible duplicate
 676                 /// `PaymentForwarded` events are generated for the same payment iff `fee_earned_msat` is
 677                 /// `None`.
 678                 fee_earned_msat: Option<u64>,
 679                 /// If this is `true`, the forwarded HTLC was claimed by our counterparty via an on-chain
 680                 /// transaction.
 681                 claim_from_onchain_tx: bool,
 682                 /// The final amount forwarded, in milli-satoshis, after the fee is deducted.
 683                 ///
 684                 /// The caveat described above the `fee_earned_msat` field applies here as well.
 685                 outbound_amount_forwarded_msat: Option<u64>,
 686         },
 687         /// Used to indicate that a channel with the given `channel_id` is being opened and pending
 688         /// confirmation on-chain.
 689         ///
 690         /// This event is emitted when the funding transaction has been signed and is broadcast to the
 691         /// network. For 0conf channels it will be immediately followed by the corresponding
 692         /// [`Event::ChannelReady`] event.
 693         ChannelPending {
 694                 /// The `channel_id` of the channel that is pending confirmation.
 695                 channel_id: [u8; 32],
 696                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
 697                 /// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
 698                 /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
 699                 /// `user_channel_id` will be randomized for an inbound channel.
 700                 ///
 701                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
 702                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 703                 /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
 704                 user_channel_id: u128,
 705                 /// The `temporary_channel_id` this channel used to be known by during channel establishment.
 706                 ///
 707                 /// Will be `None` for channels created prior to LDK version 0.0.115.
 708                 former_temporary_channel_id: Option<[u8; 32]>,
 709                 /// The `node_id` of the channel counterparty.
 710                 counterparty_node_id: PublicKey,
 711                 /// The outpoint of the channel's funding transaction.
 712                 funding_txo: OutPoint,
 713         },
 714         /// Used to indicate that a channel with the given `channel_id` is ready to
 715         /// be used. This event is emitted either when the funding transaction has been confirmed
 716         /// on-chain, or, in case of a 0conf channel, when both parties have confirmed the channel
 717         /// establishment.
 718         ChannelReady {
 719                 /// The `channel_id` of the channel that is ready.
 720                 channel_id: [u8; 32],
 721                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
 722                 /// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
 723                 /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
 724                 /// `user_channel_id` will be randomized for an inbound channel.
 725                 ///
 726                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
 727                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 728                 /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
 729                 user_channel_id: u128,
 730                 /// The `node_id` of the channel counterparty.
 731                 counterparty_node_id: PublicKey,
 732                 /// The features that this channel will operate with.
 733                 channel_type: ChannelTypeFeatures,
 734         },
 735         /// Used to indicate that a previously opened channel with the given `channel_id` is in the
 736         /// process of closure.
 737         ChannelClosed  {
 738                 /// The `channel_id` of the channel which has been closed. Note that on-chain transactions
 739                 /// resolving the channel are likely still awaiting confirmation.
 740                 channel_id: [u8; 32],
 741                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
 742                 /// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
 743                 /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
 744                 /// `user_channel_id` will be randomized for inbound channels.
 745                 /// This may be zero for inbound channels serialized prior to 0.0.113 and will always be
 746                 /// zero for objects serialized with LDK versions prior to 0.0.102.
 747                 ///
 748                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
 749                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 750                 /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
 751                 user_channel_id: u128,
 752                 /// The reason the channel was closed.
 753                 reason: ClosureReason
 754         },
 755         /// Used to indicate to the user that they can abandon the funding transaction and recycle the
 756         /// inputs for another purpose.
 757         DiscardFunding {
 758                 /// The channel_id of the channel which has been closed.
 759                 channel_id: [u8; 32],
 760                 /// The full transaction received from the user
 761                 transaction: Transaction
 762         },
 763         /// Indicates a request to open a new channel by a peer.
 764         ///
 765         /// To accept the request, call [`ChannelManager::accept_inbound_channel`]. To reject the
 766         /// request, call [`ChannelManager::force_close_without_broadcasting_txn`].
 767         ///
 768         /// The event is only triggered when a new open channel request is received and the
 769         /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true.
 770         ///
 771         /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 772         /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
 773         /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
 774         OpenChannelRequest {
 775                 /// The temporary channel ID of the channel requested to be opened.
 776                 ///
 777                 /// When responding to the request, the `temporary_channel_id` should be passed
 778                 /// back to the ChannelManager through [`ChannelManager::accept_inbound_channel`] to accept,
 779                 /// or through [`ChannelManager::force_close_without_broadcasting_txn`] to reject.
 780                 ///
 781                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 782                 /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
 783                 temporary_channel_id: [u8; 32],
 784                 /// The node_id of the counterparty requesting to open the channel.
 785                 ///
 786                 /// When responding to the request, the `counterparty_node_id` should be passed
 787                 /// back to the `ChannelManager` through [`ChannelManager::accept_inbound_channel`] to
 788                 /// accept the request, or through [`ChannelManager::force_close_without_broadcasting_txn`] to reject the
 789                 /// request.
 790                 ///
 791                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 792                 /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
 793                 counterparty_node_id: PublicKey,
 794                 /// The channel value of the requested channel.
 795                 funding_satoshis: u64,
 796                 /// Our starting balance in the channel if the request is accepted, in milli-satoshi.
 797                 push_msat: u64,
 798                 /// The features that this channel will operate with. If you reject the channel, a
 799                 /// well-behaved counterparty may automatically re-attempt the channel with a new set of
 800                 /// feature flags.
 801                 ///
 802                 /// Note that if [`ChannelTypeFeatures::supports_scid_privacy`] returns true on this type,
 803                 /// the resulting [`ChannelManager`] will not be readable by versions of LDK prior to
 804                 /// 0.0.106.
 805                 ///
 806                 /// Furthermore, note that if [`ChannelTypeFeatures::supports_zero_conf`] returns true on this type,
 807                 /// the resulting [`ChannelManager`] will not be readable by versions of LDK prior to
 808                 /// 0.0.107. Channels setting this type also need to get manually accepted via
 809                 /// [`crate::ln::channelmanager::ChannelManager::accept_inbound_channel_from_trusted_peer_0conf`],
 810                 /// or will be rejected otherwise.
 811                 ///
 812                 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 813                 channel_type: ChannelTypeFeatures,
 814         },
 815         /// Indicates that the HTLC was accepted, but could not be processed when or after attempting to
 816         /// forward it.
 817         ///
 818         /// Some scenarios where this event may be sent include:
 819         /// * Insufficient capacity in the outbound channel
 820         /// * While waiting to forward the HTLC, the channel it is meant to be forwarded through closes
 821         /// * When an unknown SCID is requested for forwarding a payment.
 822         /// * Expected MPP amount has already been reached
 823         /// * The HTLC has timed out
 824         ///
 825         /// This event, however, does not get generated if an HTLC fails to meet the forwarding
 826         /// requirements (i.e. insufficient fees paid, or a CLTV that is too soon).
 827         HTLCHandlingFailed {
 828                 /// The channel over which the HTLC was received.
 829                 prev_channel_id: [u8; 32],
 830                 /// Destination of the HTLC that failed to be processed.
 831                 failed_next_destination: HTLCDestination,
 832         },
 833         /// Indicates that a transaction originating from LDK needs to have its fee bumped. This event
 834         /// requires confirmed external funds to be readily available to spend.
 835         ///
 836         /// LDK does not currently generate this event. It is limited to the scope of channels with
 837         /// anchor outputs, which will be introduced in a future release.
 838         BumpTransaction(BumpTransactionEvent),
 839 }
 840
 841 impl Writeable for Event {
 842         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 843                 match self {
 844                         &Event::FundingGenerationReady { .. } => {
 845                                 0u8.write(writer)?;
 846                                 // We never write out FundingGenerationReady events as, upon disconnection, peers
 847                                 // drop any channels which have not yet exchanged funding_signed.
 848                         },
 849                         &Event::PaymentClaimable { ref payment_hash, ref amount_msat, counterparty_skimmed_fee_msat,
 850                                 ref purpose, ref receiver_node_id, ref via_channel_id, ref via_user_channel_id,
 851                                 ref claim_deadline, ref onion_fields
 852                         } => {
 853                                 1u8.write(writer)?;
 854                                 let mut payment_secret = None;
 855                                 let payment_preimage;
 856                                 match &purpose {
 857                                         PaymentPurpose::InvoicePayment { payment_preimage: preimage, payment_secret: secret } => {
 858                                                 payment_secret = Some(secret);
 859                                                 payment_preimage = *preimage;
 860                                         },
 861                                         PaymentPurpose::SpontaneousPayment(preimage) => {
 862                                                 payment_preimage = Some(*preimage);
 863                                         }
 864                                 }
 865                                 let skimmed_fee_opt = if counterparty_skimmed_fee_msat == 0 { None }
 866                                         else { Some(counterparty_skimmed_fee_msat) };
 867                                 write_tlv_fields!(writer, {
 868                                         (0, payment_hash, required),
 869                                         (1, receiver_node_id, option),
 870                                         (2, payment_secret, option),
 871                                         (3, via_channel_id, option),
 872                                         (4, amount_msat, required),
 873                                         (5, via_user_channel_id, option),
 874                                         // Type 6 was `user_payment_id` on 0.0.103 and earlier
 875                                         (7, claim_deadline, option),
 876                                         (8, payment_preimage, option),
 877                                         (9, onion_fields, option),
 878                                         (10, skimmed_fee_opt, option),
 879                                 });
 880                         },
 881                         &Event::PaymentSent { ref payment_id, ref payment_preimage, ref payment_hash, ref fee_paid_msat } => {
 882                                 2u8.write(writer)?;
 883                                 write_tlv_fields!(writer, {
 884                                         (0, payment_preimage, required),
 885                                         (1, payment_hash, required),
 886                                         (3, payment_id, option),
 887                                         (5, fee_paid_msat, option),
 888                                 });
 889                         },
 890                         &Event::PaymentPathFailed {
 891                                 ref payment_id, ref payment_hash, ref payment_failed_permanently, ref failure,
 892                                 ref path, ref short_channel_id,
 893                                 #[cfg(test)]
 894                                 ref error_code,
 895                                 #[cfg(test)]
 896                                 ref error_data,
 897                         } => {
 898                                 3u8.write(writer)?;
 899                                 #[cfg(test)]
 900                                 error_code.write(writer)?;
 901                                 #[cfg(test)]
 902                                 error_data.write(writer)?;
 903                                 write_tlv_fields!(writer, {
 904                                         (0, payment_hash, required),
 905                                         (1, None::<NetworkUpdate>, option), // network_update in LDK versions prior to 0.0.114
 906                                         (2, payment_failed_permanently, required),
 907                                         (3, false, required), // all_paths_failed in LDK versions prior to 0.0.114
 908                                         (4, path.blinded_tail, option),
 909                                         (5, path.hops, vec_type),
 910                                         (7, short_channel_id, option),
 911                                         (9, None::<RouteParameters>, option), // retry in LDK versions prior to 0.0.115
 912                                         (11, payment_id, option),
 913                                         (13, failure, required),
 914                                 });
 915                         },
 916                         &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
 917                                 4u8.write(writer)?;
 918                                 // Note that we now ignore these on the read end as we'll re-generate them in
 919                                 // ChannelManager, we write them here only for backwards compatibility.
 920                         },
 921                         &Event::SpendableOutputs { ref outputs } => {
 922                                 5u8.write(writer)?;
 923                                 write_tlv_fields!(writer, {
 924                                         (0, WithoutLength(outputs), required),
 925                                 });
 926                         },
 927                         &Event::HTLCIntercepted { requested_next_hop_scid, payment_hash, inbound_amount_msat, expected_outbound_amount_msat, intercept_id } => {
 928                                 6u8.write(writer)?;
 929                                 let intercept_scid = InterceptNextHop::FakeScid { requested_next_hop_scid };
 930                                 write_tlv_fields!(writer, {
 931                                         (0, intercept_id, required),
 932                                         (2, intercept_scid, required),
 933                                         (4, payment_hash, required),
 934                                         (6, inbound_amount_msat, required),
 935                                         (8, expected_outbound_amount_msat, required),
 936                                 });
 937                         }
 938                         &Event::PaymentForwarded {
 939                                 fee_earned_msat, prev_channel_id, claim_from_onchain_tx,
 940                                 next_channel_id, outbound_amount_forwarded_msat
 941                         } => {
 942                                 7u8.write(writer)?;
 943                                 write_tlv_fields!(writer, {
 944                                         (0, fee_earned_msat, option),
 945                                         (1, prev_channel_id, option),
 946                                         (2, claim_from_onchain_tx, required),
 947                                         (3, next_channel_id, option),
 948                                         (5, outbound_amount_forwarded_msat, option),
 949                                 });
 950                         },
 951                         &Event::ChannelClosed { ref channel_id, ref user_channel_id, ref reason } => {
 952                                 9u8.write(writer)?;
 953                                 // `user_channel_id` used to be a single u64 value. In order to remain backwards
 954                                 // compatible with versions prior to 0.0.113, the u128 is serialized as two
 955                                 // separate u64 values.
 956                                 let user_channel_id_low = *user_channel_id as u64;
 957                                 let user_channel_id_high = (*user_channel_id >> 64) as u64;
 958                                 write_tlv_fields!(writer, {
 959                                         (0, channel_id, required),
 960                                         (1, user_channel_id_low, required),
 961                                         (2, reason, required),
 962                                         (3, user_channel_id_high, required),
 963                                 });
 964                         },
 965                         &Event::DiscardFunding { ref channel_id, ref transaction } => {
 966                                 11u8.write(writer)?;
 967                                 write_tlv_fields!(writer, {
 968                                         (0, channel_id, required),
 969                                         (2, transaction, required)
 970                                 })
 971                         },
 972                         &Event::PaymentPathSuccessful { ref payment_id, ref payment_hash, ref path } => {
 973                                 13u8.write(writer)?;
 974                                 write_tlv_fields!(writer, {
 975                                         (0, payment_id, required),
 976                                         (2, payment_hash, option),
 977                                         (4, path.hops, vec_type),
 978                                         (6, path.blinded_tail, option),
 979                                 })
 980                         },
 981                         &Event::PaymentFailed { ref payment_id, ref payment_hash, ref reason } => {
 982                                 15u8.write(writer)?;
 983                                 write_tlv_fields!(writer, {
 984                                         (0, payment_id, required),
 985                                         (1, reason, option),
 986                                         (2, payment_hash, required),
 987                                 })
 988                         },
 989                         &Event::OpenChannelRequest { .. } => {
 990                                 17u8.write(writer)?;
 991                                 // We never write the OpenChannelRequest events as, upon disconnection, peers
 992                                 // drop any channels which have not yet exchanged funding_signed.
 993                         },
 994                         &Event::PaymentClaimed { ref payment_hash, ref amount_msat, ref purpose, ref receiver_node_id } => {
 995                                 19u8.write(writer)?;
 996                                 write_tlv_fields!(writer, {
 997                                         (0, payment_hash, required),
 998                                         (1, receiver_node_id, option),
 999                                         (2, purpose, required),
1000                                         (4, amount_msat, required),
1001                                 });
1002                         },
1003                         &Event::ProbeSuccessful { ref payment_id, ref payment_hash, ref path } => {
1004                                 21u8.write(writer)?;
1005                                 write_tlv_fields!(writer, {
1006                                         (0, payment_id, required),
1007                                         (2, payment_hash, required),
1008                                         (4, path.hops, vec_type),
1009                                         (6, path.blinded_tail, option),
1010                                 })
1011                         },
1012                         &Event::ProbeFailed { ref payment_id, ref payment_hash, ref path, ref short_channel_id } => {
1013                                 23u8.write(writer)?;
1014                                 write_tlv_fields!(writer, {
1015                                         (0, payment_id, required),
1016                                         (2, payment_hash, required),
1017                                         (4, path.hops, vec_type),
1018                                         (6, short_channel_id, option),
1019                                         (8, path.blinded_tail, option),
1020                                 })
1021                         },
1022                         &Event::HTLCHandlingFailed { ref prev_channel_id, ref failed_next_destination } => {
1023                                 25u8.write(writer)?;
1024                                 write_tlv_fields!(writer, {
1025                                         (0, prev_channel_id, required),
1026                                         (2, failed_next_destination, required),
1027                                 })
1028                         },
1029                         &Event::BumpTransaction(ref event)=> {
1030                                 27u8.write(writer)?;
1031                                 match event {
1032                                         // We never write the ChannelClose|HTLCResolution events as they'll be replayed
1033                                         // upon restarting anyway if they remain unresolved.
1034                                         BumpTransactionEvent::ChannelClose { .. } => {}
1035                                         BumpTransactionEvent::HTLCResolution { .. } => {}
1036                                 }
1037                                 write_tlv_fields!(writer, {}); // Write a length field for forwards compat
1038                         }
1039                         &Event::ChannelReady { ref channel_id, ref user_channel_id, ref counterparty_node_id, ref channel_type } => {
1040                                 29u8.write(writer)?;
1041                                 write_tlv_fields!(writer, {
1042                                         (0, channel_id, required),
1043                                         (2, user_channel_id, required),
1044                                         (4, counterparty_node_id, required),
1045                                         (6, channel_type, required),
1046                                 });
1047                         },
1048                         &Event::ChannelPending { ref channel_id, ref user_channel_id, ref former_temporary_channel_id, ref counterparty_node_id, ref funding_txo } => {
1049                                 31u8.write(writer)?;
1050                                 write_tlv_fields!(writer, {
1051                                         (0, channel_id, required),
1052                                         (2, user_channel_id, required),
1053                                         (4, former_temporary_channel_id, required),
1054                                         (6, counterparty_node_id, required),
1055                                         (8, funding_txo, required),
1056                                 });
1057                         },
1058                         // Note that, going forward, all new events must only write data inside of
1059                         // `write_tlv_fields`. Versions 0.0.101+ will ignore odd-numbered events that write
1060                         // data via `write_tlv_fields`.
1061                 }
1062                 Ok(())
1063         }
1064 }
1065 impl MaybeReadable for Event {
1066         fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
1067                 match Readable::read(reader)? {
1068                         // Note that we do not write a length-prefixed TLV for FundingGenerationReady events,
1069                         // unlike all other events, thus we return immediately here.
1070                         0u8 => Ok(None),
1071                         1u8 => {
1072                                 let f = || {
1073                                         let mut payment_hash = PaymentHash([0; 32]);
1074                                         let mut payment_preimage = None;
1075                                         let mut payment_secret = None;
1076                                         let mut amount_msat = 0;
1077                                         let mut counterparty_skimmed_fee_msat_opt = None;
1078                                         let mut receiver_node_id = None;
1079                                         let mut _user_payment_id = None::<u64>; // Used in 0.0.103 and earlier, no longer written in 0.0.116+.
1080                                         let mut via_channel_id = None;
1081                                         let mut claim_deadline = None;
1082                                         let mut via_user_channel_id = None;
1083                                         let mut onion_fields = None;
1084                                         read_tlv_fields!(reader, {
1085                                                 (0, payment_hash, required),
1086                                                 (1, receiver_node_id, option),
1087                                                 (2, payment_secret, option),
1088                                                 (3, via_channel_id, option),
1089                                                 (4, amount_msat, required),
1090                                                 (5, via_user_channel_id, option),
1091                                                 (6, _user_payment_id, option),
1092                                                 (7, claim_deadline, option),
1093                                                 (8, payment_preimage, option),
1094                                                 (9, onion_fields, option),
1095                                                 (10, counterparty_skimmed_fee_msat_opt, option),
1096                                         });
1097                                         let purpose = match payment_secret {
1098                                                 Some(secret) => PaymentPurpose::InvoicePayment {
1099                                                         payment_preimage,
1100                                                         payment_secret: secret
1101                                                 },
1102                                                 None if payment_preimage.is_some() => PaymentPurpose::SpontaneousPayment(payment_preimage.unwrap()),
1103                                                 None => return Err(msgs::DecodeError::InvalidValue),
1104                                         };
1105                                         Ok(Some(Event::PaymentClaimable {
1106                                                 receiver_node_id,
1107                                                 payment_hash,
1108                                                 amount_msat,
1109                                                 counterparty_skimmed_fee_msat: counterparty_skimmed_fee_msat_opt.unwrap_or(0),
1110                                                 purpose,
1111                                                 via_channel_id,
1112                                                 via_user_channel_id,
1113                                                 claim_deadline,
1114                                                 onion_fields,
1115                                         }))
1116                                 };
1117                                 f()
1118                         },
1119                         2u8 => {
1120                                 let f = || {
1121                                         let mut payment_preimage = PaymentPreimage([0; 32]);
1122                                         let mut payment_hash = None;
1123                                         let mut payment_id = None;
1124                                         let mut fee_paid_msat = None;
1125                                         read_tlv_fields!(reader, {
1126                                                 (0, payment_preimage, required),
1127                                                 (1, payment_hash, option),
1128                                                 (3, payment_id, option),
1129                                                 (5, fee_paid_msat, option),
1130                                         });
1131                                         if payment_hash.is_none() {
1132                                                 payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()));
1133                                         }
1134                                         Ok(Some(Event::PaymentSent {
1135                                                 payment_id,
1136                                                 payment_preimage,
1137                                                 payment_hash: payment_hash.unwrap(),
1138                                                 fee_paid_msat,
1139                                         }))
1140                                 };
1141                                 f()
1142                         },
1143                         3u8 => {
1144                                 let f = || {
1145                                         #[cfg(test)]
1146                                         let error_code = Readable::read(reader)?;
1147                                         #[cfg(test)]
1148                                         let error_data = Readable::read(reader)?;
1149                                         let mut payment_hash = PaymentHash([0; 32]);
1150                                         let mut payment_failed_permanently = false;
1151                                         let mut network_update = None;
1152                                         let mut blinded_tail: Option<BlindedTail> = None;
1153                                         let mut path: Option<Vec<RouteHop>> = Some(vec![]);
1154                                         let mut short_channel_id = None;
1155                                         let mut payment_id = None;
1156                                         let mut failure_opt = None;
1157                                         read_tlv_fields!(reader, {
1158                                                 (0, payment_hash, required),
1159                                                 (1, network_update, upgradable_option),
1160                                                 (2, payment_failed_permanently, required),
1161                                                 (4, blinded_tail, option),
1162                                                 (5, path, vec_type),
1163                                                 (7, short_channel_id, option),
1164                                                 (11, payment_id, option),
1165                                                 (13, failure_opt, upgradable_option),
1166                                         });
1167                                         let failure = failure_opt.unwrap_or_else(|| PathFailure::OnPath { network_update });
1168                                         Ok(Some(Event::PaymentPathFailed {
1169                                                 payment_id,
1170                                                 payment_hash,
1171                                                 payment_failed_permanently,
1172                                                 failure,
1173                                                 path: Path { hops: path.unwrap(), blinded_tail },
1174                                                 short_channel_id,
1175                                                 #[cfg(test)]
1176                                                 error_code,
1177                                                 #[cfg(test)]
1178                                                 error_data,
1179                                         }))
1180                                 };
1181                                 f()
1182                         },
1183                         4u8 => Ok(None),
1184                         5u8 => {
1185                                 let f = || {
1186                                         let mut outputs = WithoutLength(Vec::new());
1187                                         read_tlv_fields!(reader, {
1188                                                 (0, outputs, required),
1189                                         });
1190                                         Ok(Some(Event::SpendableOutputs { outputs: outputs.0 }))
1191                                 };
1192                                 f()
1193                         },
1194                         6u8 => {
1195                                 let mut payment_hash = PaymentHash([0; 32]);
1196                                 let mut intercept_id = InterceptId([0; 32]);
1197                                 let mut requested_next_hop_scid = InterceptNextHop::FakeScid { requested_next_hop_scid: 0 };
1198                                 let mut inbound_amount_msat = 0;
1199                                 let mut expected_outbound_amount_msat = 0;
1200                                 read_tlv_fields!(reader, {
1201                                         (0, intercept_id, required),
1202                                         (2, requested_next_hop_scid, required),
1203                                         (4, payment_hash, required),
1204                                         (6, inbound_amount_msat, required),
1205                                         (8, expected_outbound_amount_msat, required),
1206                                 });
1207                                 let next_scid = match requested_next_hop_scid {
1208                                         InterceptNextHop::FakeScid { requested_next_hop_scid: scid } => scid
1209                                 };
1210                                 Ok(Some(Event::HTLCIntercepted {
1211                                         payment_hash,
1212                                         requested_next_hop_scid: next_scid,
1213                                         inbound_amount_msat,
1214                                         expected_outbound_amount_msat,
1215                                         intercept_id,
1216                                 }))
1217                         },
1218                         7u8 => {
1219                                 let f = || {
1220                                         let mut fee_earned_msat = None;
1221                                         let mut prev_channel_id = None;
1222                                         let mut claim_from_onchain_tx = false;
1223                                         let mut next_channel_id = None;
1224                                         let mut outbound_amount_forwarded_msat = None;
1225                                         read_tlv_fields!(reader, {
1226                                                 (0, fee_earned_msat, option),
1227                                                 (1, prev_channel_id, option),
1228                                                 (2, claim_from_onchain_tx, required),
1229                                                 (3, next_channel_id, option),
1230                                                 (5, outbound_amount_forwarded_msat, option),
1231                                         });
1232                                         Ok(Some(Event::PaymentForwarded {
1233                                                 fee_earned_msat, prev_channel_id, claim_from_onchain_tx, next_channel_id,
1234                                                 outbound_amount_forwarded_msat
1235                                         }))
1236                                 };
1237                                 f()
1238                         },
1239                         9u8 => {
1240                                 let f = || {
1241                                         let mut channel_id = [0; 32];
1242                                         let mut reason = UpgradableRequired(None);
1243                                         let mut user_channel_id_low_opt: Option<u64> = None;
1244                                         let mut user_channel_id_high_opt: Option<u64> = None;
1245                                         read_tlv_fields!(reader, {
1246                                                 (0, channel_id, required),
1247                                                 (1, user_channel_id_low_opt, option),
1248                                                 (2, reason, upgradable_required),
1249                                                 (3, user_channel_id_high_opt, option),
1250                                         });
1251
1252                                         // `user_channel_id` used to be a single u64 value. In order to remain
1253                                         // backwards compatible with versions prior to 0.0.113, the u128 is serialized
1254                                         // as two separate u64 values.
1255                                         let user_channel_id = (user_channel_id_low_opt.unwrap_or(0) as u128) +
1256                                                 ((user_channel_id_high_opt.unwrap_or(0) as u128) << 64);
1257
1258                                         Ok(Some(Event::ChannelClosed { channel_id, user_channel_id, reason: _init_tlv_based_struct_field!(reason, upgradable_required) }))
1259                                 };
1260                                 f()
1261                         },
1262                         11u8 => {
1263                                 let f = || {
1264                                         let mut channel_id = [0; 32];
1265                                         let mut transaction = Transaction{ version: 2, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
1266                                         read_tlv_fields!(reader, {
1267                                                 (0, channel_id, required),
1268                                                 (2, transaction, required),
1269                                         });
1270                                         Ok(Some(Event::DiscardFunding { channel_id, transaction } ))
1271                                 };
1272                                 f()
1273                         },
1274                         13u8 => {
1275                                 let f = || {
1276                                         _init_and_read_tlv_fields!(reader, {
1277                                                 (0, payment_id, required),
1278                                                 (2, payment_hash, option),
1279                                                 (4, path, vec_type),
1280                                                 (6, blinded_tail, option),
1281                                         });
1282                                         Ok(Some(Event::PaymentPathSuccessful {
1283                                                 payment_id: payment_id.0.unwrap(),
1284                                                 payment_hash,
1285                                                 path: Path { hops: path.unwrap(), blinded_tail },
1286                                         }))
1287                                 };
1288                                 f()
1289                         },
1290                         15u8 => {
1291                                 let f = || {
1292                                         let mut payment_hash = PaymentHash([0; 32]);
1293                                         let mut payment_id = PaymentId([0; 32]);
1294                                         let mut reason = None;
1295                                         read_tlv_fields!(reader, {
1296                                                 (0, payment_id, required),
1297                                                 (1, reason, upgradable_option),
1298                                                 (2, payment_hash, required),
1299                                         });
1300                                         Ok(Some(Event::PaymentFailed {
1301                                                 payment_id,
1302                                                 payment_hash,
1303                                                 reason,
1304                                         }))
1305                                 };
1306                                 f()
1307                         },
1308                         17u8 => {
1309                                 // Value 17 is used for `Event::OpenChannelRequest`.
1310                                 Ok(None)
1311                         },
1312                         19u8 => {
1313                                 let f = || {
1314                                         let mut payment_hash = PaymentHash([0; 32]);
1315                                         let mut purpose = UpgradableRequired(None);
1316                                         let mut amount_msat = 0;
1317                                         let mut receiver_node_id = None;
1318                                         read_tlv_fields!(reader, {
1319                                                 (0, payment_hash, required),
1320                                                 (1, receiver_node_id, option),
1321                                                 (2, purpose, upgradable_required),
1322                                                 (4, amount_msat, required),
1323                                         });
1324                                         Ok(Some(Event::PaymentClaimed {
1325                                                 receiver_node_id,
1326                                                 payment_hash,
1327                                                 purpose: _init_tlv_based_struct_field!(purpose, upgradable_required),
1328                                                 amount_msat,
1329                                         }))
1330                                 };
1331                                 f()
1332                         },
1333                         21u8 => {
1334                                 let f = || {
1335                                         _init_and_read_tlv_fields!(reader, {
1336                                                 (0, payment_id, required),
1337                                                 (2, payment_hash, required),
1338                                                 (4, path, vec_type),
1339                                                 (6, blinded_tail, option),
1340                                         });
1341                                         Ok(Some(Event::ProbeSuccessful {
1342                                                 payment_id: payment_id.0.unwrap(),
1343                                                 payment_hash: payment_hash.0.unwrap(),
1344                                                 path: Path { hops: path.unwrap(), blinded_tail },
1345                                         }))
1346                                 };
1347                                 f()
1348                         },
1349                         23u8 => {
1350                                 let f = || {
1351                                         _init_and_read_tlv_fields!(reader, {
1352                                                 (0, payment_id, required),
1353                                                 (2, payment_hash, required),
1354                                                 (4, path, vec_type),
1355                                                 (6, short_channel_id, option),
1356                                                 (8, blinded_tail, option),
1357                                         });
1358                                         Ok(Some(Event::ProbeFailed {
1359                                                 payment_id: payment_id.0.unwrap(),
1360                                                 payment_hash: payment_hash.0.unwrap(),
1361                                                 path: Path { hops: path.unwrap(), blinded_tail },
1362                                                 short_channel_id,
1363                                         }))
1364                                 };
1365                                 f()
1366                         },
1367                         25u8 => {
1368                                 let f = || {
1369                                         let mut prev_channel_id = [0; 32];
1370                                         let mut failed_next_destination_opt = UpgradableRequired(None);
1371                                         read_tlv_fields!(reader, {
1372                                                 (0, prev_channel_id, required),
1373                                                 (2, failed_next_destination_opt, upgradable_required),
1374                                         });
1375                                         Ok(Some(Event::HTLCHandlingFailed {
1376                                                 prev_channel_id,
1377                                                 failed_next_destination: _init_tlv_based_struct_field!(failed_next_destination_opt, upgradable_required),
1378                                         }))
1379                                 };
1380                                 f()
1381                         },
1382                         27u8 => Ok(None),
1383                         29u8 => {
1384                                 let f = || {
1385                                         let mut channel_id = [0; 32];
1386                                         let mut user_channel_id: u128 = 0;
1387                                         let mut counterparty_node_id = RequiredWrapper(None);
1388                                         let mut channel_type = RequiredWrapper(None);
1389                                         read_tlv_fields!(reader, {
1390                                                 (0, channel_id, required),
1391                                                 (2, user_channel_id, required),
1392                                                 (4, counterparty_node_id, required),
1393                                                 (6, channel_type, required),
1394                                         });
1395
1396                                         Ok(Some(Event::ChannelReady {
1397                                                 channel_id,
1398                                                 user_channel_id,
1399                                                 counterparty_node_id: counterparty_node_id.0.unwrap(),
1400                                                 channel_type: channel_type.0.unwrap()
1401                                         }))
1402                                 };
1403                                 f()
1404                         },
1405                         31u8 => {
1406                                 let f = || {
1407                                         let mut channel_id = [0; 32];
1408                                         let mut user_channel_id: u128 = 0;
1409                                         let mut former_temporary_channel_id = None;
1410                                         let mut counterparty_node_id = RequiredWrapper(None);
1411                                         let mut funding_txo = RequiredWrapper(None);
1412                                         read_tlv_fields!(reader, {
1413                                                 (0, channel_id, required),
1414                                                 (2, user_channel_id, required),
1415                                                 (4, former_temporary_channel_id, required),
1416                                                 (6, counterparty_node_id, required),
1417                                                 (8, funding_txo, required),
1418                                         });
1419
1420                                         Ok(Some(Event::ChannelPending {
1421                                                 channel_id,
1422                                                 user_channel_id,
1423                                                 former_temporary_channel_id,
1424                                                 counterparty_node_id: counterparty_node_id.0.unwrap(),
1425                                                 funding_txo: funding_txo.0.unwrap()
1426                                         }))
1427                                 };
1428                                 f()
1429                         },
1430                         // Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue.
1431                         // Version 0.0.100 failed to properly ignore odd types, possibly resulting in corrupt
1432                         // reads.
1433                         x if x % 2 == 1 => {
1434                                 // If the event is of unknown type, assume it was written with `write_tlv_fields`,
1435                                 // which prefixes the whole thing with a length BigSize. Because the event is
1436                                 // odd-type unknown, we should treat it as `Ok(None)` even if it has some TLV
1437                                 // fields that are even. Thus, we avoid using `read_tlv_fields` and simply read
1438                                 // exactly the number of bytes specified, ignoring them entirely.
1439                                 let tlv_len: BigSize = Readable::read(reader)?;
1440                                 FixedLengthReader::new(reader, tlv_len.0)
1441                                         .eat_remaining().map_err(|_| msgs::DecodeError::ShortRead)?;
1442                                 Ok(None)
1443                         },
1444                         _ => Err(msgs::DecodeError::InvalidValue)
1445                 }
1446         }
1447 }
1448
1449 /// An event generated by ChannelManager which indicates a message should be sent to a peer (or
1450 /// broadcast to most peers).
1451 /// These events are handled by PeerManager::process_events if you are using a PeerManager.
1452 #[derive(Clone, Debug)]
1453 pub enum MessageSendEvent {
1454         /// Used to indicate that we've accepted a channel open and should send the accept_channel
1455         /// message provided to the given peer.
1456         SendAcceptChannel {
1457                 /// The node_id of the node which should receive this message
1458                 node_id: PublicKey,
1459                 /// The message which should be sent.
1460                 msg: msgs::AcceptChannel,
1461         },
1462         /// Used to indicate that we've accepted a V2 channel open and should send the accept_channel2
1463         /// message provided to the given peer.
1464         SendAcceptChannelV2 {
1465                 /// The node_id of the node which should receive this message
1466                 node_id: PublicKey,
1467                 /// The message which should be sent.
1468                 msg: msgs::AcceptChannelV2,
1469         },
1470         /// Used to indicate that we've initiated a channel open and should send the open_channel
1471         /// message provided to the given peer.
1472         SendOpenChannel {
1473                 /// The node_id of the node which should receive this message
1474                 node_id: PublicKey,
1475                 /// The message which should be sent.
1476                 msg: msgs::OpenChannel,
1477         },
1478         /// Used to indicate that we've initiated a V2 channel open and should send the open_channel2
1479         /// message provided to the given peer.
1480         SendOpenChannelV2 {
1481                 /// The node_id of the node which should receive this message
1482                 node_id: PublicKey,
1483                 /// The message which should be sent.
1484                 msg: msgs::OpenChannelV2,
1485         },
1486         /// Used to indicate that a funding_created message should be sent to the peer with the given node_id.
1487         SendFundingCreated {
1488                 /// The node_id of the node which should receive this message
1489                 node_id: PublicKey,
1490                 /// The message which should be sent.
1491                 msg: msgs::FundingCreated,
1492         },
1493         /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id.
1494         SendFundingSigned {
1495                 /// The node_id of the node which should receive this message
1496                 node_id: PublicKey,
1497                 /// The message which should be sent.
1498                 msg: msgs::FundingSigned,
1499         },
1500         /// Used to indicate that a tx_add_input message should be sent to the peer with the given node_id.
1501         SendTxAddInput {
1502                 /// The node_id of the node which should receive this message
1503                 node_id: PublicKey,
1504                 /// The message which should be sent.
1505                 msg: msgs::TxAddInput,
1506         },
1507         /// Used to indicate that a tx_add_output message should be sent to the peer with the given node_id.
1508         SendTxAddOutput {
1509                 /// The node_id of the node which should receive this message
1510                 node_id: PublicKey,
1511                 /// The message which should be sent.
1512                 msg: msgs::TxAddOutput,
1513         },
1514         /// Used to indicate that a tx_remove_input message should be sent to the peer with the given node_id.
1515         SendTxRemoveInput {
1516                 /// The node_id of the node which should receive this message
1517                 node_id: PublicKey,
1518                 /// The message which should be sent.
1519                 msg: msgs::TxRemoveInput,
1520         },
1521         /// Used to indicate that a tx_remove_output message should be sent to the peer with the given node_id.
1522         SendTxRemoveOutput {
1523                 /// The node_id of the node which should receive this message
1524                 node_id: PublicKey,
1525                 /// The message which should be sent.
1526                 msg: msgs::TxRemoveOutput,
1527         },
1528         /// Used to indicate that a tx_complete message should be sent to the peer with the given node_id.
1529         SendTxComplete {
1530                 /// The node_id of the node which should receive this message
1531                 node_id: PublicKey,
1532                 /// The message which should be sent.
1533                 msg: msgs::TxComplete,
1534         },
1535         /// Used to indicate that a tx_signatures message should be sent to the peer with the given node_id.
1536         SendTxSignatures {
1537                 /// The node_id of the node which should receive this message
1538                 node_id: PublicKey,
1539                 /// The message which should be sent.
1540                 msg: msgs::TxSignatures,
1541         },
1542         /// Used to indicate that a tx_init_rbf message should be sent to the peer with the given node_id.
1543         SendTxInitRbf {
1544                 /// The node_id of the node which should receive this message
1545                 node_id: PublicKey,
1546                 /// The message which should be sent.
1547                 msg: msgs::TxInitRbf,
1548         },
1549         /// Used to indicate that a tx_ack_rbf message should be sent to the peer with the given node_id.
1550         SendTxAckRbf {
1551                 /// The node_id of the node which should receive this message
1552                 node_id: PublicKey,
1553                 /// The message which should be sent.
1554                 msg: msgs::TxAckRbf,
1555         },
1556         /// Used to indicate that a tx_abort message should be sent to the peer with the given node_id.
1557         SendTxAbort {
1558                 /// The node_id of the node which should receive this message
1559                 node_id: PublicKey,
1560                 /// The message which should be sent.
1561                 msg: msgs::TxAddInput,
1562         },
1563         /// Used to indicate that a channel_ready message should be sent to the peer with the given node_id.
1564         SendChannelReady {
1565                 /// The node_id of the node which should receive these message(s)
1566                 node_id: PublicKey,
1567                 /// The channel_ready message which should be sent.
1568                 msg: msgs::ChannelReady,
1569         },
1570         /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
1571         SendAnnouncementSignatures {
1572                 /// The node_id of the node which should receive these message(s)
1573                 node_id: PublicKey,
1574                 /// The announcement_signatures message which should be sent.
1575                 msg: msgs::AnnouncementSignatures,
1576         },
1577         /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed
1578         /// message should be sent to the peer with the given node_id.
1579         UpdateHTLCs {
1580                 /// The node_id of the node which should receive these message(s)
1581                 node_id: PublicKey,
1582                 /// The update messages which should be sent. ALL messages in the struct should be sent!
1583                 updates: msgs::CommitmentUpdate,
1584         },
1585         /// Used to indicate that a revoke_and_ack message should be sent to the peer with the given node_id.
1586         SendRevokeAndACK {
1587                 /// The node_id of the node which should receive this message
1588                 node_id: PublicKey,
1589                 /// The message which should be sent.
1590                 msg: msgs::RevokeAndACK,
1591         },
1592         /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id.
1593         SendClosingSigned {
1594                 /// The node_id of the node which should receive this message
1595                 node_id: PublicKey,
1596                 /// The message which should be sent.
1597                 msg: msgs::ClosingSigned,
1598         },
1599         /// Used to indicate that a shutdown message should be sent to the peer with the given node_id.
1600         SendShutdown {
1601                 /// The node_id of the node which should receive this message
1602                 node_id: PublicKey,
1603                 /// The message which should be sent.
1604                 msg: msgs::Shutdown,
1605         },
1606         /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id.
1607         SendChannelReestablish {
1608                 /// The node_id of the node which should receive this message
1609                 node_id: PublicKey,
1610                 /// The message which should be sent.
1611                 msg: msgs::ChannelReestablish,
1612         },
1613         /// Used to send a channel_announcement and channel_update to a specific peer, likely on
1614         /// initial connection to ensure our peers know about our channels.
1615         SendChannelAnnouncement {
1616                 /// The node_id of the node which should receive this message
1617                 node_id: PublicKey,
1618                 /// The channel_announcement which should be sent.
1619                 msg: msgs::ChannelAnnouncement,
1620                 /// The followup channel_update which should be sent.
1621                 update_msg: msgs::ChannelUpdate,
1622         },
1623         /// Used to indicate that a channel_announcement and channel_update should be broadcast to all
1624         /// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
1625         ///
1626         /// Note that after doing so, you very likely (unless you did so very recently) want to
1627         /// broadcast a node_announcement (e.g. via [`PeerManager::broadcast_node_announcement`]). This
1628         /// ensures that any nodes which see our channel_announcement also have a relevant
1629         /// node_announcement, including relevant feature flags which may be important for routing
1630         /// through or to us.
1631         ///
1632         /// [`PeerManager::broadcast_node_announcement`]: crate::ln::peer_handler::PeerManager::broadcast_node_announcement
1633         BroadcastChannelAnnouncement {
1634                 /// The channel_announcement which should be sent.
1635                 msg: msgs::ChannelAnnouncement,
1636                 /// The followup channel_update which should be sent.
1637                 update_msg: Option<msgs::ChannelUpdate>,
1638         },
1639         /// Used to indicate that a channel_update should be broadcast to all peers.
1640         BroadcastChannelUpdate {
1641                 /// The channel_update which should be sent.
1642                 msg: msgs::ChannelUpdate,
1643         },
1644         /// Used to indicate that a node_announcement should be broadcast to all peers.
1645         BroadcastNodeAnnouncement {
1646                 /// The node_announcement which should be sent.
1647                 msg: msgs::NodeAnnouncement,
1648         },
1649         /// Used to indicate that a channel_update should be sent to a single peer.
1650         /// In contrast to [`Self::BroadcastChannelUpdate`], this is used when the channel is a
1651         /// private channel and we shouldn't be informing all of our peers of channel parameters.
1652         SendChannelUpdate {
1653                 /// The node_id of the node which should receive this message
1654                 node_id: PublicKey,
1655                 /// The channel_update which should be sent.
1656                 msg: msgs::ChannelUpdate,
1657         },
1658         /// Broadcast an error downstream to be handled
1659         HandleError {
1660                 /// The node_id of the node which should receive this message
1661                 node_id: PublicKey,
1662                 /// The action which should be taken.
1663                 action: msgs::ErrorAction
1664         },
1665         /// Query a peer for channels with funding transaction UTXOs in a block range.
1666         SendChannelRangeQuery {
1667                 /// The node_id of this message recipient
1668                 node_id: PublicKey,
1669                 /// The query_channel_range which should be sent.
1670                 msg: msgs::QueryChannelRange,
1671         },
1672         /// Request routing gossip messages from a peer for a list of channels identified by
1673         /// their short_channel_ids.
1674         SendShortIdsQuery {
1675                 /// The node_id of this message recipient
1676                 node_id: PublicKey,
1677                 /// The query_short_channel_ids which should be sent.
1678                 msg: msgs::QueryShortChannelIds,
1679         },
1680         /// Sends a reply to a channel range query. This may be one of several SendReplyChannelRange events
1681         /// emitted during processing of the query.
1682         SendReplyChannelRange {
1683                 /// The node_id of this message recipient
1684                 node_id: PublicKey,
1685                 /// The reply_channel_range which should be sent.
1686                 msg: msgs::ReplyChannelRange,
1687         },
1688         /// Sends a timestamp filter for inbound gossip. This should be sent on each new connection to
1689         /// enable receiving gossip messages from the peer.
1690         SendGossipTimestampFilter {
1691                 /// The node_id of this message recipient
1692                 node_id: PublicKey,
1693                 /// The gossip_timestamp_filter which should be sent.
1694                 msg: msgs::GossipTimestampFilter,
1695         },
1696 }
1697
1698 /// A trait indicating an object may generate message send events
1699 pub trait MessageSendEventsProvider {
1700         /// Gets the list of pending events which were generated by previous actions, clearing the list
1701         /// in the process.
1702         fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
1703 }
1704
1705 /// A trait indicating an object may generate onion messages to send
1706 pub trait OnionMessageProvider {
1707         /// Gets the next pending onion message for the peer with the given node id.
1708         fn next_onion_message_for_peer(&self, peer_node_id: PublicKey) -> Option<msgs::OnionMessage>;
1709 }
1710
1711 /// A trait indicating an object may generate events.
1712 ///
1713 /// Events are processed by passing an [`EventHandler`] to [`process_pending_events`].
1714 ///
1715 /// Implementations of this trait may also feature an async version of event handling, as shown with
1716 /// [`ChannelManager::process_pending_events_async`] and
1717 /// [`ChainMonitor::process_pending_events_async`].
1718 ///
1719 /// # Requirements
1720 ///
1721 /// When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
1722 /// event since the last invocation.
1723 ///
1724 /// In order to ensure no [`Event`]s are lost, implementors of this trait will persist [`Event`]s
1725 /// and replay any unhandled events on startup. An [`Event`] is considered handled when
1726 /// [`process_pending_events`] returns, thus handlers MUST fully handle [`Event`]s and persist any
1727 /// relevant changes to disk *before* returning.
1728 ///
1729 /// Further, because an application may crash between an [`Event`] being handled and the
1730 /// implementor of this trait being re-serialized, [`Event`] handling must be idempotent - in
1731 /// effect, [`Event`]s may be replayed.
1732 ///
1733 /// Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
1734 /// consult the provider's documentation on the implication of processing events and how a handler
1735 /// may safely use the provider (e.g., see [`ChannelManager::process_pending_events`] and
1736 /// [`ChainMonitor::process_pending_events`]).
1737 ///
1738 /// (C-not implementable) As there is likely no reason for a user to implement this trait on their
1739 /// own type(s).
1740 ///
1741 /// [`process_pending_events`]: Self::process_pending_events
1742 /// [`handle_event`]: EventHandler::handle_event
1743 /// [`ChannelManager::process_pending_events`]: crate::ln::channelmanager::ChannelManager#method.process_pending_events
1744 /// [`ChainMonitor::process_pending_events`]: crate::chain::chainmonitor::ChainMonitor#method.process_pending_events
1745 /// [`ChannelManager::process_pending_events_async`]: crate::ln::channelmanager::ChannelManager::process_pending_events_async
1746 /// [`ChainMonitor::process_pending_events_async`]: crate::chain::chainmonitor::ChainMonitor::process_pending_events_async
1747 pub trait EventsProvider {
1748         /// Processes any events generated since the last call using the given event handler.
1749         ///
1750         /// See the trait-level documentation for requirements.
1751         fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler;
1752 }
1753
1754 /// A trait implemented for objects handling events from [`EventsProvider`].
1755 ///
1756 /// An async variation also exists for implementations of [`EventsProvider`] that support async
1757 /// event handling. The async event handler should satisfy the generic bounds: `F:
1758 /// core::future::Future, H: Fn(Event) -> F`.
1759 pub trait EventHandler {
1760         /// Handles the given [`Event`].
1761         ///
1762         /// See [`EventsProvider`] for details that must be considered when implementing this method.
1763         fn handle_event(&self, event: Event);
1764 }
1765
1766 impl<F> EventHandler for F where F: Fn(Event) {
1767         fn handle_event(&self, event: Event) {
1768                 self(event)
1769         }
1770 }
1771
1772 impl<T: EventHandler> EventHandler for Arc<T> {
1773         fn handle_event(&self, event: Event) {
1774                 self.deref().handle_event(event)
1775         }
1776 }